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Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * kernel/sched.c | |
3 | * | |
4 | * Kernel scheduler and related syscalls | |
5 | * | |
6 | * Copyright (C) 1991-2002 Linus Torvalds | |
7 | * | |
8 | * 1996-12-23 Modified by Dave Grothe to fix bugs in semaphores and | |
9 | * make semaphores SMP safe | |
10 | * 1998-11-19 Implemented schedule_timeout() and related stuff | |
11 | * by Andrea Arcangeli | |
12 | * 2002-01-04 New ultra-scalable O(1) scheduler by Ingo Molnar: | |
13 | * hybrid priority-list and round-robin design with | |
14 | * an array-switch method of distributing timeslices | |
15 | * and per-CPU runqueues. Cleanups and useful suggestions | |
16 | * by Davide Libenzi, preemptible kernel bits by Robert Love. | |
17 | * 2003-09-03 Interactivity tuning by Con Kolivas. | |
18 | * 2004-04-02 Scheduler domains code by Nick Piggin | |
c31f2e8a IM |
19 | * 2007-04-15 Work begun on replacing all interactivity tuning with a |
20 | * fair scheduling design by Con Kolivas. | |
21 | * 2007-05-05 Load balancing (smp-nice) and other improvements | |
22 | * by Peter Williams | |
23 | * 2007-05-06 Interactivity improvements to CFS by Mike Galbraith | |
24 | * 2007-07-01 Group scheduling enhancements by Srivatsa Vaddagiri | |
b9131769 IM |
25 | * 2007-11-29 RT balancing improvements by Steven Rostedt, Gregory Haskins, |
26 | * Thomas Gleixner, Mike Kravetz | |
1da177e4 LT |
27 | */ |
28 | ||
29 | #include <linux/mm.h> | |
30 | #include <linux/module.h> | |
31 | #include <linux/nmi.h> | |
32 | #include <linux/init.h> | |
dff06c15 | 33 | #include <linux/uaccess.h> |
1da177e4 LT |
34 | #include <linux/highmem.h> |
35 | #include <linux/smp_lock.h> | |
36 | #include <asm/mmu_context.h> | |
37 | #include <linux/interrupt.h> | |
c59ede7b | 38 | #include <linux/capability.h> |
1da177e4 LT |
39 | #include <linux/completion.h> |
40 | #include <linux/kernel_stat.h> | |
9a11b49a | 41 | #include <linux/debug_locks.h> |
cdd6c482 | 42 | #include <linux/perf_event.h> |
1da177e4 LT |
43 | #include <linux/security.h> |
44 | #include <linux/notifier.h> | |
45 | #include <linux/profile.h> | |
7dfb7103 | 46 | #include <linux/freezer.h> |
198e2f18 | 47 | #include <linux/vmalloc.h> |
1da177e4 LT |
48 | #include <linux/blkdev.h> |
49 | #include <linux/delay.h> | |
b488893a | 50 | #include <linux/pid_namespace.h> |
1da177e4 LT |
51 | #include <linux/smp.h> |
52 | #include <linux/threads.h> | |
53 | #include <linux/timer.h> | |
54 | #include <linux/rcupdate.h> | |
55 | #include <linux/cpu.h> | |
56 | #include <linux/cpuset.h> | |
57 | #include <linux/percpu.h> | |
58 | #include <linux/kthread.h> | |
b5aadf7f | 59 | #include <linux/proc_fs.h> |
1da177e4 | 60 | #include <linux/seq_file.h> |
e692ab53 | 61 | #include <linux/sysctl.h> |
1da177e4 LT |
62 | #include <linux/syscalls.h> |
63 | #include <linux/times.h> | |
8f0ab514 | 64 | #include <linux/tsacct_kern.h> |
c6fd91f0 | 65 | #include <linux/kprobes.h> |
0ff92245 | 66 | #include <linux/delayacct.h> |
dff06c15 | 67 | #include <linux/unistd.h> |
f5ff8422 | 68 | #include <linux/pagemap.h> |
8f4d37ec | 69 | #include <linux/hrtimer.h> |
30914a58 | 70 | #include <linux/tick.h> |
f00b45c1 PZ |
71 | #include <linux/debugfs.h> |
72 | #include <linux/ctype.h> | |
6cd8a4bb | 73 | #include <linux/ftrace.h> |
1da177e4 | 74 | |
5517d86b | 75 | #include <asm/tlb.h> |
838225b4 | 76 | #include <asm/irq_regs.h> |
1da177e4 | 77 | |
6e0534f2 GH |
78 | #include "sched_cpupri.h" |
79 | ||
a8d154b0 | 80 | #define CREATE_TRACE_POINTS |
ad8d75ff | 81 | #include <trace/events/sched.h> |
a8d154b0 | 82 | |
1da177e4 LT |
83 | /* |
84 | * Convert user-nice values [ -20 ... 0 ... 19 ] | |
85 | * to static priority [ MAX_RT_PRIO..MAX_PRIO-1 ], | |
86 | * and back. | |
87 | */ | |
88 | #define NICE_TO_PRIO(nice) (MAX_RT_PRIO + (nice) + 20) | |
89 | #define PRIO_TO_NICE(prio) ((prio) - MAX_RT_PRIO - 20) | |
90 | #define TASK_NICE(p) PRIO_TO_NICE((p)->static_prio) | |
91 | ||
92 | /* | |
93 | * 'User priority' is the nice value converted to something we | |
94 | * can work with better when scaling various scheduler parameters, | |
95 | * it's a [ 0 ... 39 ] range. | |
96 | */ | |
97 | #define USER_PRIO(p) ((p)-MAX_RT_PRIO) | |
98 | #define TASK_USER_PRIO(p) USER_PRIO((p)->static_prio) | |
99 | #define MAX_USER_PRIO (USER_PRIO(MAX_PRIO)) | |
100 | ||
101 | /* | |
d7876a08 | 102 | * Helpers for converting nanosecond timing to jiffy resolution |
1da177e4 | 103 | */ |
d6322faf | 104 | #define NS_TO_JIFFIES(TIME) ((unsigned long)(TIME) / (NSEC_PER_SEC / HZ)) |
1da177e4 | 105 | |
6aa645ea IM |
106 | #define NICE_0_LOAD SCHED_LOAD_SCALE |
107 | #define NICE_0_SHIFT SCHED_LOAD_SHIFT | |
108 | ||
1da177e4 LT |
109 | /* |
110 | * These are the 'tuning knobs' of the scheduler: | |
111 | * | |
a4ec24b4 | 112 | * default timeslice is 100 msecs (used only for SCHED_RR tasks). |
1da177e4 LT |
113 | * Timeslices get refilled after they expire. |
114 | */ | |
1da177e4 | 115 | #define DEF_TIMESLICE (100 * HZ / 1000) |
2dd73a4f | 116 | |
d0b27fa7 PZ |
117 | /* |
118 | * single value that denotes runtime == period, ie unlimited time. | |
119 | */ | |
120 | #define RUNTIME_INF ((u64)~0ULL) | |
121 | ||
e05606d3 IM |
122 | static inline int rt_policy(int policy) |
123 | { | |
3f33a7ce | 124 | if (unlikely(policy == SCHED_FIFO || policy == SCHED_RR)) |
e05606d3 IM |
125 | return 1; |
126 | return 0; | |
127 | } | |
128 | ||
129 | static inline int task_has_rt_policy(struct task_struct *p) | |
130 | { | |
131 | return rt_policy(p->policy); | |
132 | } | |
133 | ||
1da177e4 | 134 | /* |
6aa645ea | 135 | * This is the priority-queue data structure of the RT scheduling class: |
1da177e4 | 136 | */ |
6aa645ea IM |
137 | struct rt_prio_array { |
138 | DECLARE_BITMAP(bitmap, MAX_RT_PRIO+1); /* include 1 bit for delimiter */ | |
139 | struct list_head queue[MAX_RT_PRIO]; | |
140 | }; | |
141 | ||
d0b27fa7 | 142 | struct rt_bandwidth { |
ea736ed5 | 143 | /* nests inside the rq lock: */ |
0986b11b | 144 | raw_spinlock_t rt_runtime_lock; |
ea736ed5 IM |
145 | ktime_t rt_period; |
146 | u64 rt_runtime; | |
147 | struct hrtimer rt_period_timer; | |
d0b27fa7 PZ |
148 | }; |
149 | ||
150 | static struct rt_bandwidth def_rt_bandwidth; | |
151 | ||
152 | static int do_sched_rt_period_timer(struct rt_bandwidth *rt_b, int overrun); | |
153 | ||
154 | static enum hrtimer_restart sched_rt_period_timer(struct hrtimer *timer) | |
155 | { | |
156 | struct rt_bandwidth *rt_b = | |
157 | container_of(timer, struct rt_bandwidth, rt_period_timer); | |
158 | ktime_t now; | |
159 | int overrun; | |
160 | int idle = 0; | |
161 | ||
162 | for (;;) { | |
163 | now = hrtimer_cb_get_time(timer); | |
164 | overrun = hrtimer_forward(timer, now, rt_b->rt_period); | |
165 | ||
166 | if (!overrun) | |
167 | break; | |
168 | ||
169 | idle = do_sched_rt_period_timer(rt_b, overrun); | |
170 | } | |
171 | ||
172 | return idle ? HRTIMER_NORESTART : HRTIMER_RESTART; | |
173 | } | |
174 | ||
175 | static | |
176 | void init_rt_bandwidth(struct rt_bandwidth *rt_b, u64 period, u64 runtime) | |
177 | { | |
178 | rt_b->rt_period = ns_to_ktime(period); | |
179 | rt_b->rt_runtime = runtime; | |
180 | ||
0986b11b | 181 | raw_spin_lock_init(&rt_b->rt_runtime_lock); |
ac086bc2 | 182 | |
d0b27fa7 PZ |
183 | hrtimer_init(&rt_b->rt_period_timer, |
184 | CLOCK_MONOTONIC, HRTIMER_MODE_REL); | |
185 | rt_b->rt_period_timer.function = sched_rt_period_timer; | |
d0b27fa7 PZ |
186 | } |
187 | ||
c8bfff6d KH |
188 | static inline int rt_bandwidth_enabled(void) |
189 | { | |
190 | return sysctl_sched_rt_runtime >= 0; | |
d0b27fa7 PZ |
191 | } |
192 | ||
193 | static void start_rt_bandwidth(struct rt_bandwidth *rt_b) | |
194 | { | |
195 | ktime_t now; | |
196 | ||
cac64d00 | 197 | if (!rt_bandwidth_enabled() || rt_b->rt_runtime == RUNTIME_INF) |
d0b27fa7 PZ |
198 | return; |
199 | ||
200 | if (hrtimer_active(&rt_b->rt_period_timer)) | |
201 | return; | |
202 | ||
0986b11b | 203 | raw_spin_lock(&rt_b->rt_runtime_lock); |
d0b27fa7 | 204 | for (;;) { |
7f1e2ca9 PZ |
205 | unsigned long delta; |
206 | ktime_t soft, hard; | |
207 | ||
d0b27fa7 PZ |
208 | if (hrtimer_active(&rt_b->rt_period_timer)) |
209 | break; | |
210 | ||
211 | now = hrtimer_cb_get_time(&rt_b->rt_period_timer); | |
212 | hrtimer_forward(&rt_b->rt_period_timer, now, rt_b->rt_period); | |
7f1e2ca9 PZ |
213 | |
214 | soft = hrtimer_get_softexpires(&rt_b->rt_period_timer); | |
215 | hard = hrtimer_get_expires(&rt_b->rt_period_timer); | |
216 | delta = ktime_to_ns(ktime_sub(hard, soft)); | |
217 | __hrtimer_start_range_ns(&rt_b->rt_period_timer, soft, delta, | |
5c333864 | 218 | HRTIMER_MODE_ABS_PINNED, 0); |
d0b27fa7 | 219 | } |
0986b11b | 220 | raw_spin_unlock(&rt_b->rt_runtime_lock); |
d0b27fa7 PZ |
221 | } |
222 | ||
223 | #ifdef CONFIG_RT_GROUP_SCHED | |
224 | static void destroy_rt_bandwidth(struct rt_bandwidth *rt_b) | |
225 | { | |
226 | hrtimer_cancel(&rt_b->rt_period_timer); | |
227 | } | |
228 | #endif | |
229 | ||
712555ee HC |
230 | /* |
231 | * sched_domains_mutex serializes calls to arch_init_sched_domains, | |
232 | * detach_destroy_domains and partition_sched_domains. | |
233 | */ | |
234 | static DEFINE_MUTEX(sched_domains_mutex); | |
235 | ||
052f1dc7 | 236 | #ifdef CONFIG_GROUP_SCHED |
29f59db3 | 237 | |
68318b8e SV |
238 | #include <linux/cgroup.h> |
239 | ||
29f59db3 SV |
240 | struct cfs_rq; |
241 | ||
6f505b16 PZ |
242 | static LIST_HEAD(task_groups); |
243 | ||
29f59db3 | 244 | /* task group related information */ |
4cf86d77 | 245 | struct task_group { |
052f1dc7 | 246 | #ifdef CONFIG_CGROUP_SCHED |
68318b8e SV |
247 | struct cgroup_subsys_state css; |
248 | #endif | |
052f1dc7 | 249 | |
6c415b92 AB |
250 | #ifdef CONFIG_USER_SCHED |
251 | uid_t uid; | |
252 | #endif | |
253 | ||
052f1dc7 | 254 | #ifdef CONFIG_FAIR_GROUP_SCHED |
29f59db3 SV |
255 | /* schedulable entities of this group on each cpu */ |
256 | struct sched_entity **se; | |
257 | /* runqueue "owned" by this group on each cpu */ | |
258 | struct cfs_rq **cfs_rq; | |
259 | unsigned long shares; | |
052f1dc7 PZ |
260 | #endif |
261 | ||
262 | #ifdef CONFIG_RT_GROUP_SCHED | |
263 | struct sched_rt_entity **rt_se; | |
264 | struct rt_rq **rt_rq; | |
265 | ||
d0b27fa7 | 266 | struct rt_bandwidth rt_bandwidth; |
052f1dc7 | 267 | #endif |
6b2d7700 | 268 | |
ae8393e5 | 269 | struct rcu_head rcu; |
6f505b16 | 270 | struct list_head list; |
f473aa5e PZ |
271 | |
272 | struct task_group *parent; | |
273 | struct list_head siblings; | |
274 | struct list_head children; | |
29f59db3 SV |
275 | }; |
276 | ||
354d60c2 | 277 | #ifdef CONFIG_USER_SCHED |
eff766a6 | 278 | |
6c415b92 AB |
279 | /* Helper function to pass uid information to create_sched_user() */ |
280 | void set_tg_uid(struct user_struct *user) | |
281 | { | |
282 | user->tg->uid = user->uid; | |
283 | } | |
284 | ||
eff766a6 PZ |
285 | /* |
286 | * Root task group. | |
84e9dabf AS |
287 | * Every UID task group (including init_task_group aka UID-0) will |
288 | * be a child to this group. | |
eff766a6 PZ |
289 | */ |
290 | struct task_group root_task_group; | |
291 | ||
052f1dc7 | 292 | #ifdef CONFIG_FAIR_GROUP_SCHED |
29f59db3 SV |
293 | /* Default task group's sched entity on each cpu */ |
294 | static DEFINE_PER_CPU(struct sched_entity, init_sched_entity); | |
295 | /* Default task group's cfs_rq on each cpu */ | |
ada3fa15 | 296 | static DEFINE_PER_CPU_SHARED_ALIGNED(struct cfs_rq, init_tg_cfs_rq); |
6d6bc0ad | 297 | #endif /* CONFIG_FAIR_GROUP_SCHED */ |
052f1dc7 PZ |
298 | |
299 | #ifdef CONFIG_RT_GROUP_SCHED | |
300 | static DEFINE_PER_CPU(struct sched_rt_entity, init_sched_rt_entity); | |
1871e52c | 301 | static DEFINE_PER_CPU_SHARED_ALIGNED(struct rt_rq, init_rt_rq_var); |
6d6bc0ad | 302 | #endif /* CONFIG_RT_GROUP_SCHED */ |
9a7e0b18 | 303 | #else /* !CONFIG_USER_SCHED */ |
eff766a6 | 304 | #define root_task_group init_task_group |
9a7e0b18 | 305 | #endif /* CONFIG_USER_SCHED */ |
6f505b16 | 306 | |
8ed36996 | 307 | /* task_group_lock serializes add/remove of task groups and also changes to |
ec2c507f SV |
308 | * a task group's cpu shares. |
309 | */ | |
8ed36996 | 310 | static DEFINE_SPINLOCK(task_group_lock); |
ec2c507f | 311 | |
e9036b36 CG |
312 | #ifdef CONFIG_FAIR_GROUP_SCHED |
313 | ||
57310a98 PZ |
314 | #ifdef CONFIG_SMP |
315 | static int root_task_group_empty(void) | |
316 | { | |
317 | return list_empty(&root_task_group.children); | |
318 | } | |
319 | #endif | |
320 | ||
052f1dc7 PZ |
321 | #ifdef CONFIG_USER_SCHED |
322 | # define INIT_TASK_GROUP_LOAD (2*NICE_0_LOAD) | |
6d6bc0ad | 323 | #else /* !CONFIG_USER_SCHED */ |
052f1dc7 | 324 | # define INIT_TASK_GROUP_LOAD NICE_0_LOAD |
6d6bc0ad | 325 | #endif /* CONFIG_USER_SCHED */ |
052f1dc7 | 326 | |
cb4ad1ff | 327 | /* |
2e084786 LJ |
328 | * A weight of 0 or 1 can cause arithmetics problems. |
329 | * A weight of a cfs_rq is the sum of weights of which entities | |
330 | * are queued on this cfs_rq, so a weight of a entity should not be | |
331 | * too large, so as the shares value of a task group. | |
cb4ad1ff MX |
332 | * (The default weight is 1024 - so there's no practical |
333 | * limitation from this.) | |
334 | */ | |
18d95a28 | 335 | #define MIN_SHARES 2 |
2e084786 | 336 | #define MAX_SHARES (1UL << 18) |
18d95a28 | 337 | |
052f1dc7 PZ |
338 | static int init_task_group_load = INIT_TASK_GROUP_LOAD; |
339 | #endif | |
340 | ||
29f59db3 | 341 | /* Default task group. |
3a252015 | 342 | * Every task in system belong to this group at bootup. |
29f59db3 | 343 | */ |
434d53b0 | 344 | struct task_group init_task_group; |
29f59db3 SV |
345 | |
346 | /* return group to which a task belongs */ | |
4cf86d77 | 347 | static inline struct task_group *task_group(struct task_struct *p) |
29f59db3 | 348 | { |
4cf86d77 | 349 | struct task_group *tg; |
9b5b7751 | 350 | |
052f1dc7 | 351 | #ifdef CONFIG_USER_SCHED |
c69e8d9c DH |
352 | rcu_read_lock(); |
353 | tg = __task_cred(p)->user->tg; | |
354 | rcu_read_unlock(); | |
052f1dc7 | 355 | #elif defined(CONFIG_CGROUP_SCHED) |
68318b8e SV |
356 | tg = container_of(task_subsys_state(p, cpu_cgroup_subsys_id), |
357 | struct task_group, css); | |
24e377a8 | 358 | #else |
41a2d6cf | 359 | tg = &init_task_group; |
24e377a8 | 360 | #endif |
9b5b7751 | 361 | return tg; |
29f59db3 SV |
362 | } |
363 | ||
364 | /* Change a task's cfs_rq and parent entity if it moves across CPUs/groups */ | |
6f505b16 | 365 | static inline void set_task_rq(struct task_struct *p, unsigned int cpu) |
29f59db3 | 366 | { |
052f1dc7 | 367 | #ifdef CONFIG_FAIR_GROUP_SCHED |
ce96b5ac DA |
368 | p->se.cfs_rq = task_group(p)->cfs_rq[cpu]; |
369 | p->se.parent = task_group(p)->se[cpu]; | |
052f1dc7 | 370 | #endif |
6f505b16 | 371 | |
052f1dc7 | 372 | #ifdef CONFIG_RT_GROUP_SCHED |
6f505b16 PZ |
373 | p->rt.rt_rq = task_group(p)->rt_rq[cpu]; |
374 | p->rt.parent = task_group(p)->rt_se[cpu]; | |
052f1dc7 | 375 | #endif |
29f59db3 SV |
376 | } |
377 | ||
378 | #else | |
379 | ||
6f505b16 | 380 | static inline void set_task_rq(struct task_struct *p, unsigned int cpu) { } |
83378269 PZ |
381 | static inline struct task_group *task_group(struct task_struct *p) |
382 | { | |
383 | return NULL; | |
384 | } | |
29f59db3 | 385 | |
052f1dc7 | 386 | #endif /* CONFIG_GROUP_SCHED */ |
29f59db3 | 387 | |
6aa645ea IM |
388 | /* CFS-related fields in a runqueue */ |
389 | struct cfs_rq { | |
390 | struct load_weight load; | |
391 | unsigned long nr_running; | |
392 | ||
6aa645ea | 393 | u64 exec_clock; |
e9acbff6 | 394 | u64 min_vruntime; |
6aa645ea IM |
395 | |
396 | struct rb_root tasks_timeline; | |
397 | struct rb_node *rb_leftmost; | |
4a55bd5e PZ |
398 | |
399 | struct list_head tasks; | |
400 | struct list_head *balance_iterator; | |
401 | ||
402 | /* | |
403 | * 'curr' points to currently running entity on this cfs_rq. | |
6aa645ea IM |
404 | * It is set to NULL otherwise (i.e when none are currently running). |
405 | */ | |
4793241b | 406 | struct sched_entity *curr, *next, *last; |
ddc97297 | 407 | |
5ac5c4d6 | 408 | unsigned int nr_spread_over; |
ddc97297 | 409 | |
62160e3f | 410 | #ifdef CONFIG_FAIR_GROUP_SCHED |
6aa645ea IM |
411 | struct rq *rq; /* cpu runqueue to which this cfs_rq is attached */ |
412 | ||
41a2d6cf IM |
413 | /* |
414 | * leaf cfs_rqs are those that hold tasks (lowest schedulable entity in | |
6aa645ea IM |
415 | * a hierarchy). Non-leaf lrqs hold other higher schedulable entities |
416 | * (like users, containers etc.) | |
417 | * | |
418 | * leaf_cfs_rq_list ties together list of leaf cfs_rq's in a cpu. This | |
419 | * list is used during load balance. | |
420 | */ | |
41a2d6cf IM |
421 | struct list_head leaf_cfs_rq_list; |
422 | struct task_group *tg; /* group that "owns" this runqueue */ | |
c09595f6 PZ |
423 | |
424 | #ifdef CONFIG_SMP | |
c09595f6 | 425 | /* |
c8cba857 | 426 | * the part of load.weight contributed by tasks |
c09595f6 | 427 | */ |
c8cba857 | 428 | unsigned long task_weight; |
c09595f6 | 429 | |
c8cba857 PZ |
430 | /* |
431 | * h_load = weight * f(tg) | |
432 | * | |
433 | * Where f(tg) is the recursive weight fraction assigned to | |
434 | * this group. | |
435 | */ | |
436 | unsigned long h_load; | |
c09595f6 | 437 | |
c8cba857 PZ |
438 | /* |
439 | * this cpu's part of tg->shares | |
440 | */ | |
441 | unsigned long shares; | |
f1d239f7 PZ |
442 | |
443 | /* | |
444 | * load.weight at the time we set shares | |
445 | */ | |
446 | unsigned long rq_weight; | |
c09595f6 | 447 | #endif |
6aa645ea IM |
448 | #endif |
449 | }; | |
1da177e4 | 450 | |
6aa645ea IM |
451 | /* Real-Time classes' related field in a runqueue: */ |
452 | struct rt_rq { | |
453 | struct rt_prio_array active; | |
63489e45 | 454 | unsigned long rt_nr_running; |
052f1dc7 | 455 | #if defined CONFIG_SMP || defined CONFIG_RT_GROUP_SCHED |
e864c499 GH |
456 | struct { |
457 | int curr; /* highest queued rt task prio */ | |
398a153b | 458 | #ifdef CONFIG_SMP |
e864c499 | 459 | int next; /* next highest */ |
398a153b | 460 | #endif |
e864c499 | 461 | } highest_prio; |
6f505b16 | 462 | #endif |
fa85ae24 | 463 | #ifdef CONFIG_SMP |
73fe6aae | 464 | unsigned long rt_nr_migratory; |
a1ba4d8b | 465 | unsigned long rt_nr_total; |
a22d7fc1 | 466 | int overloaded; |
917b627d | 467 | struct plist_head pushable_tasks; |
fa85ae24 | 468 | #endif |
6f505b16 | 469 | int rt_throttled; |
fa85ae24 | 470 | u64 rt_time; |
ac086bc2 | 471 | u64 rt_runtime; |
ea736ed5 | 472 | /* Nests inside the rq lock: */ |
0986b11b | 473 | raw_spinlock_t rt_runtime_lock; |
6f505b16 | 474 | |
052f1dc7 | 475 | #ifdef CONFIG_RT_GROUP_SCHED |
23b0fdfc PZ |
476 | unsigned long rt_nr_boosted; |
477 | ||
6f505b16 PZ |
478 | struct rq *rq; |
479 | struct list_head leaf_rt_rq_list; | |
480 | struct task_group *tg; | |
481 | struct sched_rt_entity *rt_se; | |
482 | #endif | |
6aa645ea IM |
483 | }; |
484 | ||
57d885fe GH |
485 | #ifdef CONFIG_SMP |
486 | ||
487 | /* | |
488 | * We add the notion of a root-domain which will be used to define per-domain | |
0eab9146 IM |
489 | * variables. Each exclusive cpuset essentially defines an island domain by |
490 | * fully partitioning the member cpus from any other cpuset. Whenever a new | |
57d885fe GH |
491 | * exclusive cpuset is created, we also create and attach a new root-domain |
492 | * object. | |
493 | * | |
57d885fe GH |
494 | */ |
495 | struct root_domain { | |
496 | atomic_t refcount; | |
c6c4927b RR |
497 | cpumask_var_t span; |
498 | cpumask_var_t online; | |
637f5085 | 499 | |
0eab9146 | 500 | /* |
637f5085 GH |
501 | * The "RT overload" flag: it gets set if a CPU has more than |
502 | * one runnable RT task. | |
503 | */ | |
c6c4927b | 504 | cpumask_var_t rto_mask; |
0eab9146 | 505 | atomic_t rto_count; |
6e0534f2 GH |
506 | #ifdef CONFIG_SMP |
507 | struct cpupri cpupri; | |
508 | #endif | |
57d885fe GH |
509 | }; |
510 | ||
dc938520 GH |
511 | /* |
512 | * By default the system creates a single root-domain with all cpus as | |
513 | * members (mimicking the global state we have today). | |
514 | */ | |
57d885fe GH |
515 | static struct root_domain def_root_domain; |
516 | ||
517 | #endif | |
518 | ||
1da177e4 LT |
519 | /* |
520 | * This is the main, per-CPU runqueue data structure. | |
521 | * | |
522 | * Locking rule: those places that want to lock multiple runqueues | |
523 | * (such as the load balancing or the thread migration code), lock | |
524 | * acquire operations must be ordered by ascending &runqueue. | |
525 | */ | |
70b97a7f | 526 | struct rq { |
d8016491 | 527 | /* runqueue lock: */ |
05fa785c | 528 | raw_spinlock_t lock; |
1da177e4 LT |
529 | |
530 | /* | |
531 | * nr_running and cpu_load should be in the same cacheline because | |
532 | * remote CPUs use both these fields when doing load calculation. | |
533 | */ | |
534 | unsigned long nr_running; | |
6aa645ea IM |
535 | #define CPU_LOAD_IDX_MAX 5 |
536 | unsigned long cpu_load[CPU_LOAD_IDX_MAX]; | |
46cb4b7c SS |
537 | #ifdef CONFIG_NO_HZ |
538 | unsigned char in_nohz_recently; | |
539 | #endif | |
d8016491 IM |
540 | /* capture load from *all* tasks on this cpu: */ |
541 | struct load_weight load; | |
6aa645ea IM |
542 | unsigned long nr_load_updates; |
543 | u64 nr_switches; | |
544 | ||
545 | struct cfs_rq cfs; | |
6f505b16 | 546 | struct rt_rq rt; |
6f505b16 | 547 | |
6aa645ea | 548 | #ifdef CONFIG_FAIR_GROUP_SCHED |
d8016491 IM |
549 | /* list of leaf cfs_rq on this cpu: */ |
550 | struct list_head leaf_cfs_rq_list; | |
052f1dc7 PZ |
551 | #endif |
552 | #ifdef CONFIG_RT_GROUP_SCHED | |
6f505b16 | 553 | struct list_head leaf_rt_rq_list; |
1da177e4 | 554 | #endif |
1da177e4 LT |
555 | |
556 | /* | |
557 | * This is part of a global counter where only the total sum | |
558 | * over all CPUs matters. A task can increase this counter on | |
559 | * one CPU and if it got migrated afterwards it may decrease | |
560 | * it on another CPU. Always updated under the runqueue lock: | |
561 | */ | |
562 | unsigned long nr_uninterruptible; | |
563 | ||
36c8b586 | 564 | struct task_struct *curr, *idle; |
c9819f45 | 565 | unsigned long next_balance; |
1da177e4 | 566 | struct mm_struct *prev_mm; |
6aa645ea | 567 | |
3e51f33f | 568 | u64 clock; |
6aa645ea | 569 | |
1da177e4 LT |
570 | atomic_t nr_iowait; |
571 | ||
572 | #ifdef CONFIG_SMP | |
0eab9146 | 573 | struct root_domain *rd; |
1da177e4 LT |
574 | struct sched_domain *sd; |
575 | ||
a0a522ce | 576 | unsigned char idle_at_tick; |
1da177e4 | 577 | /* For active balancing */ |
3f029d3c | 578 | int post_schedule; |
1da177e4 LT |
579 | int active_balance; |
580 | int push_cpu; | |
d8016491 IM |
581 | /* cpu of this runqueue: */ |
582 | int cpu; | |
1f11eb6a | 583 | int online; |
1da177e4 | 584 | |
a8a51d5e | 585 | unsigned long avg_load_per_task; |
1da177e4 | 586 | |
36c8b586 | 587 | struct task_struct *migration_thread; |
1da177e4 | 588 | struct list_head migration_queue; |
e9e9250b PZ |
589 | |
590 | u64 rt_avg; | |
591 | u64 age_stamp; | |
1b9508f6 MG |
592 | u64 idle_stamp; |
593 | u64 avg_idle; | |
1da177e4 LT |
594 | #endif |
595 | ||
dce48a84 TG |
596 | /* calc_load related fields */ |
597 | unsigned long calc_load_update; | |
598 | long calc_load_active; | |
599 | ||
8f4d37ec | 600 | #ifdef CONFIG_SCHED_HRTICK |
31656519 PZ |
601 | #ifdef CONFIG_SMP |
602 | int hrtick_csd_pending; | |
603 | struct call_single_data hrtick_csd; | |
604 | #endif | |
8f4d37ec PZ |
605 | struct hrtimer hrtick_timer; |
606 | #endif | |
607 | ||
1da177e4 LT |
608 | #ifdef CONFIG_SCHEDSTATS |
609 | /* latency stats */ | |
610 | struct sched_info rq_sched_info; | |
9c2c4802 KC |
611 | unsigned long long rq_cpu_time; |
612 | /* could above be rq->cfs_rq.exec_clock + rq->rt_rq.rt_runtime ? */ | |
1da177e4 LT |
613 | |
614 | /* sys_sched_yield() stats */ | |
480b9434 | 615 | unsigned int yld_count; |
1da177e4 LT |
616 | |
617 | /* schedule() stats */ | |
480b9434 KC |
618 | unsigned int sched_switch; |
619 | unsigned int sched_count; | |
620 | unsigned int sched_goidle; | |
1da177e4 LT |
621 | |
622 | /* try_to_wake_up() stats */ | |
480b9434 KC |
623 | unsigned int ttwu_count; |
624 | unsigned int ttwu_local; | |
b8efb561 IM |
625 | |
626 | /* BKL stats */ | |
480b9434 | 627 | unsigned int bkl_count; |
1da177e4 LT |
628 | #endif |
629 | }; | |
630 | ||
f34e3b61 | 631 | static DEFINE_PER_CPU_SHARED_ALIGNED(struct rq, runqueues); |
1da177e4 | 632 | |
7d478721 PZ |
633 | static inline |
634 | void check_preempt_curr(struct rq *rq, struct task_struct *p, int flags) | |
dd41f596 | 635 | { |
7d478721 | 636 | rq->curr->sched_class->check_preempt_curr(rq, p, flags); |
dd41f596 IM |
637 | } |
638 | ||
0a2966b4 CL |
639 | static inline int cpu_of(struct rq *rq) |
640 | { | |
641 | #ifdef CONFIG_SMP | |
642 | return rq->cpu; | |
643 | #else | |
644 | return 0; | |
645 | #endif | |
646 | } | |
647 | ||
674311d5 NP |
648 | /* |
649 | * The domain tree (rq->sd) is protected by RCU's quiescent state transition. | |
1a20ff27 | 650 | * See detach_destroy_domains: synchronize_sched for details. |
674311d5 NP |
651 | * |
652 | * The domain tree of any CPU may only be accessed from within | |
653 | * preempt-disabled sections. | |
654 | */ | |
48f24c4d IM |
655 | #define for_each_domain(cpu, __sd) \ |
656 | for (__sd = rcu_dereference(cpu_rq(cpu)->sd); __sd; __sd = __sd->parent) | |
1da177e4 LT |
657 | |
658 | #define cpu_rq(cpu) (&per_cpu(runqueues, (cpu))) | |
659 | #define this_rq() (&__get_cpu_var(runqueues)) | |
660 | #define task_rq(p) cpu_rq(task_cpu(p)) | |
661 | #define cpu_curr(cpu) (cpu_rq(cpu)->curr) | |
54d35f29 | 662 | #define raw_rq() (&__raw_get_cpu_var(runqueues)) |
1da177e4 | 663 | |
aa9c4c0f | 664 | inline void update_rq_clock(struct rq *rq) |
3e51f33f PZ |
665 | { |
666 | rq->clock = sched_clock_cpu(cpu_of(rq)); | |
667 | } | |
668 | ||
bf5c91ba IM |
669 | /* |
670 | * Tunables that become constants when CONFIG_SCHED_DEBUG is off: | |
671 | */ | |
672 | #ifdef CONFIG_SCHED_DEBUG | |
673 | # define const_debug __read_mostly | |
674 | #else | |
675 | # define const_debug static const | |
676 | #endif | |
677 | ||
017730c1 IM |
678 | /** |
679 | * runqueue_is_locked | |
e17b38bf | 680 | * @cpu: the processor in question. |
017730c1 IM |
681 | * |
682 | * Returns true if the current cpu runqueue is locked. | |
683 | * This interface allows printk to be called with the runqueue lock | |
684 | * held and know whether or not it is OK to wake up the klogd. | |
685 | */ | |
89f19f04 | 686 | int runqueue_is_locked(int cpu) |
017730c1 | 687 | { |
05fa785c | 688 | return raw_spin_is_locked(&cpu_rq(cpu)->lock); |
017730c1 IM |
689 | } |
690 | ||
bf5c91ba IM |
691 | /* |
692 | * Debugging: various feature bits | |
693 | */ | |
f00b45c1 PZ |
694 | |
695 | #define SCHED_FEAT(name, enabled) \ | |
696 | __SCHED_FEAT_##name , | |
697 | ||
bf5c91ba | 698 | enum { |
f00b45c1 | 699 | #include "sched_features.h" |
bf5c91ba IM |
700 | }; |
701 | ||
f00b45c1 PZ |
702 | #undef SCHED_FEAT |
703 | ||
704 | #define SCHED_FEAT(name, enabled) \ | |
705 | (1UL << __SCHED_FEAT_##name) * enabled | | |
706 | ||
bf5c91ba | 707 | const_debug unsigned int sysctl_sched_features = |
f00b45c1 PZ |
708 | #include "sched_features.h" |
709 | 0; | |
710 | ||
711 | #undef SCHED_FEAT | |
712 | ||
713 | #ifdef CONFIG_SCHED_DEBUG | |
714 | #define SCHED_FEAT(name, enabled) \ | |
715 | #name , | |
716 | ||
983ed7a6 | 717 | static __read_mostly char *sched_feat_names[] = { |
f00b45c1 PZ |
718 | #include "sched_features.h" |
719 | NULL | |
720 | }; | |
721 | ||
722 | #undef SCHED_FEAT | |
723 | ||
34f3a814 | 724 | static int sched_feat_show(struct seq_file *m, void *v) |
f00b45c1 | 725 | { |
f00b45c1 PZ |
726 | int i; |
727 | ||
728 | for (i = 0; sched_feat_names[i]; i++) { | |
34f3a814 LZ |
729 | if (!(sysctl_sched_features & (1UL << i))) |
730 | seq_puts(m, "NO_"); | |
731 | seq_printf(m, "%s ", sched_feat_names[i]); | |
f00b45c1 | 732 | } |
34f3a814 | 733 | seq_puts(m, "\n"); |
f00b45c1 | 734 | |
34f3a814 | 735 | return 0; |
f00b45c1 PZ |
736 | } |
737 | ||
738 | static ssize_t | |
739 | sched_feat_write(struct file *filp, const char __user *ubuf, | |
740 | size_t cnt, loff_t *ppos) | |
741 | { | |
742 | char buf[64]; | |
743 | char *cmp = buf; | |
744 | int neg = 0; | |
745 | int i; | |
746 | ||
747 | if (cnt > 63) | |
748 | cnt = 63; | |
749 | ||
750 | if (copy_from_user(&buf, ubuf, cnt)) | |
751 | return -EFAULT; | |
752 | ||
753 | buf[cnt] = 0; | |
754 | ||
c24b7c52 | 755 | if (strncmp(buf, "NO_", 3) == 0) { |
f00b45c1 PZ |
756 | neg = 1; |
757 | cmp += 3; | |
758 | } | |
759 | ||
760 | for (i = 0; sched_feat_names[i]; i++) { | |
761 | int len = strlen(sched_feat_names[i]); | |
762 | ||
763 | if (strncmp(cmp, sched_feat_names[i], len) == 0) { | |
764 | if (neg) | |
765 | sysctl_sched_features &= ~(1UL << i); | |
766 | else | |
767 | sysctl_sched_features |= (1UL << i); | |
768 | break; | |
769 | } | |
770 | } | |
771 | ||
772 | if (!sched_feat_names[i]) | |
773 | return -EINVAL; | |
774 | ||
42994724 | 775 | *ppos += cnt; |
f00b45c1 PZ |
776 | |
777 | return cnt; | |
778 | } | |
779 | ||
34f3a814 LZ |
780 | static int sched_feat_open(struct inode *inode, struct file *filp) |
781 | { | |
782 | return single_open(filp, sched_feat_show, NULL); | |
783 | } | |
784 | ||
828c0950 | 785 | static const struct file_operations sched_feat_fops = { |
34f3a814 LZ |
786 | .open = sched_feat_open, |
787 | .write = sched_feat_write, | |
788 | .read = seq_read, | |
789 | .llseek = seq_lseek, | |
790 | .release = single_release, | |
f00b45c1 PZ |
791 | }; |
792 | ||
793 | static __init int sched_init_debug(void) | |
794 | { | |
f00b45c1 PZ |
795 | debugfs_create_file("sched_features", 0644, NULL, NULL, |
796 | &sched_feat_fops); | |
797 | ||
798 | return 0; | |
799 | } | |
800 | late_initcall(sched_init_debug); | |
801 | ||
802 | #endif | |
803 | ||
804 | #define sched_feat(x) (sysctl_sched_features & (1UL << __SCHED_FEAT_##x)) | |
bf5c91ba | 805 | |
b82d9fdd PZ |
806 | /* |
807 | * Number of tasks to iterate in a single balance run. | |
808 | * Limited because this is done with IRQs disabled. | |
809 | */ | |
810 | const_debug unsigned int sysctl_sched_nr_migrate = 32; | |
811 | ||
2398f2c6 PZ |
812 | /* |
813 | * ratelimit for updating the group shares. | |
55cd5340 | 814 | * default: 0.25ms |
2398f2c6 | 815 | */ |
55cd5340 | 816 | unsigned int sysctl_sched_shares_ratelimit = 250000; |
0bcdcf28 | 817 | unsigned int normalized_sysctl_sched_shares_ratelimit = 250000; |
2398f2c6 | 818 | |
ffda12a1 PZ |
819 | /* |
820 | * Inject some fuzzyness into changing the per-cpu group shares | |
821 | * this avoids remote rq-locks at the expense of fairness. | |
822 | * default: 4 | |
823 | */ | |
824 | unsigned int sysctl_sched_shares_thresh = 4; | |
825 | ||
e9e9250b PZ |
826 | /* |
827 | * period over which we average the RT time consumption, measured | |
828 | * in ms. | |
829 | * | |
830 | * default: 1s | |
831 | */ | |
832 | const_debug unsigned int sysctl_sched_time_avg = MSEC_PER_SEC; | |
833 | ||
fa85ae24 | 834 | /* |
9f0c1e56 | 835 | * period over which we measure -rt task cpu usage in us. |
fa85ae24 PZ |
836 | * default: 1s |
837 | */ | |
9f0c1e56 | 838 | unsigned int sysctl_sched_rt_period = 1000000; |
fa85ae24 | 839 | |
6892b75e IM |
840 | static __read_mostly int scheduler_running; |
841 | ||
9f0c1e56 PZ |
842 | /* |
843 | * part of the period that we allow rt tasks to run in us. | |
844 | * default: 0.95s | |
845 | */ | |
846 | int sysctl_sched_rt_runtime = 950000; | |
fa85ae24 | 847 | |
d0b27fa7 PZ |
848 | static inline u64 global_rt_period(void) |
849 | { | |
850 | return (u64)sysctl_sched_rt_period * NSEC_PER_USEC; | |
851 | } | |
852 | ||
853 | static inline u64 global_rt_runtime(void) | |
854 | { | |
e26873bb | 855 | if (sysctl_sched_rt_runtime < 0) |
d0b27fa7 PZ |
856 | return RUNTIME_INF; |
857 | ||
858 | return (u64)sysctl_sched_rt_runtime * NSEC_PER_USEC; | |
859 | } | |
fa85ae24 | 860 | |
1da177e4 | 861 | #ifndef prepare_arch_switch |
4866cde0 NP |
862 | # define prepare_arch_switch(next) do { } while (0) |
863 | #endif | |
864 | #ifndef finish_arch_switch | |
865 | # define finish_arch_switch(prev) do { } while (0) | |
866 | #endif | |
867 | ||
051a1d1a DA |
868 | static inline int task_current(struct rq *rq, struct task_struct *p) |
869 | { | |
870 | return rq->curr == p; | |
871 | } | |
872 | ||
4866cde0 | 873 | #ifndef __ARCH_WANT_UNLOCKED_CTXSW |
70b97a7f | 874 | static inline int task_running(struct rq *rq, struct task_struct *p) |
4866cde0 | 875 | { |
051a1d1a | 876 | return task_current(rq, p); |
4866cde0 NP |
877 | } |
878 | ||
70b97a7f | 879 | static inline void prepare_lock_switch(struct rq *rq, struct task_struct *next) |
4866cde0 NP |
880 | { |
881 | } | |
882 | ||
70b97a7f | 883 | static inline void finish_lock_switch(struct rq *rq, struct task_struct *prev) |
4866cde0 | 884 | { |
da04c035 IM |
885 | #ifdef CONFIG_DEBUG_SPINLOCK |
886 | /* this is a valid case when another task releases the spinlock */ | |
887 | rq->lock.owner = current; | |
888 | #endif | |
8a25d5de IM |
889 | /* |
890 | * If we are tracking spinlock dependencies then we have to | |
891 | * fix up the runqueue lock - which gets 'carried over' from | |
892 | * prev into current: | |
893 | */ | |
894 | spin_acquire(&rq->lock.dep_map, 0, 0, _THIS_IP_); | |
895 | ||
05fa785c | 896 | raw_spin_unlock_irq(&rq->lock); |
4866cde0 NP |
897 | } |
898 | ||
899 | #else /* __ARCH_WANT_UNLOCKED_CTXSW */ | |
70b97a7f | 900 | static inline int task_running(struct rq *rq, struct task_struct *p) |
4866cde0 NP |
901 | { |
902 | #ifdef CONFIG_SMP | |
903 | return p->oncpu; | |
904 | #else | |
051a1d1a | 905 | return task_current(rq, p); |
4866cde0 NP |
906 | #endif |
907 | } | |
908 | ||
70b97a7f | 909 | static inline void prepare_lock_switch(struct rq *rq, struct task_struct *next) |
4866cde0 NP |
910 | { |
911 | #ifdef CONFIG_SMP | |
912 | /* | |
913 | * We can optimise this out completely for !SMP, because the | |
914 | * SMP rebalancing from interrupt is the only thing that cares | |
915 | * here. | |
916 | */ | |
917 | next->oncpu = 1; | |
918 | #endif | |
919 | #ifdef __ARCH_WANT_INTERRUPTS_ON_CTXSW | |
05fa785c | 920 | raw_spin_unlock_irq(&rq->lock); |
4866cde0 | 921 | #else |
05fa785c | 922 | raw_spin_unlock(&rq->lock); |
4866cde0 NP |
923 | #endif |
924 | } | |
925 | ||
70b97a7f | 926 | static inline void finish_lock_switch(struct rq *rq, struct task_struct *prev) |
4866cde0 NP |
927 | { |
928 | #ifdef CONFIG_SMP | |
929 | /* | |
930 | * After ->oncpu is cleared, the task can be moved to a different CPU. | |
931 | * We must ensure this doesn't happen until the switch is completely | |
932 | * finished. | |
933 | */ | |
934 | smp_wmb(); | |
935 | prev->oncpu = 0; | |
936 | #endif | |
937 | #ifndef __ARCH_WANT_INTERRUPTS_ON_CTXSW | |
938 | local_irq_enable(); | |
1da177e4 | 939 | #endif |
4866cde0 NP |
940 | } |
941 | #endif /* __ARCH_WANT_UNLOCKED_CTXSW */ | |
1da177e4 | 942 | |
b29739f9 IM |
943 | /* |
944 | * __task_rq_lock - lock the runqueue a given task resides on. | |
945 | * Must be called interrupts disabled. | |
946 | */ | |
70b97a7f | 947 | static inline struct rq *__task_rq_lock(struct task_struct *p) |
b29739f9 IM |
948 | __acquires(rq->lock) |
949 | { | |
3a5c359a AK |
950 | for (;;) { |
951 | struct rq *rq = task_rq(p); | |
05fa785c | 952 | raw_spin_lock(&rq->lock); |
3a5c359a AK |
953 | if (likely(rq == task_rq(p))) |
954 | return rq; | |
05fa785c | 955 | raw_spin_unlock(&rq->lock); |
b29739f9 | 956 | } |
b29739f9 IM |
957 | } |
958 | ||
1da177e4 LT |
959 | /* |
960 | * task_rq_lock - lock the runqueue a given task resides on and disable | |
41a2d6cf | 961 | * interrupts. Note the ordering: we can safely lookup the task_rq without |
1da177e4 LT |
962 | * explicitly disabling preemption. |
963 | */ | |
70b97a7f | 964 | static struct rq *task_rq_lock(struct task_struct *p, unsigned long *flags) |
1da177e4 LT |
965 | __acquires(rq->lock) |
966 | { | |
70b97a7f | 967 | struct rq *rq; |
1da177e4 | 968 | |
3a5c359a AK |
969 | for (;;) { |
970 | local_irq_save(*flags); | |
971 | rq = task_rq(p); | |
05fa785c | 972 | raw_spin_lock(&rq->lock); |
3a5c359a AK |
973 | if (likely(rq == task_rq(p))) |
974 | return rq; | |
05fa785c | 975 | raw_spin_unlock_irqrestore(&rq->lock, *flags); |
1da177e4 | 976 | } |
1da177e4 LT |
977 | } |
978 | ||
ad474cac ON |
979 | void task_rq_unlock_wait(struct task_struct *p) |
980 | { | |
981 | struct rq *rq = task_rq(p); | |
982 | ||
983 | smp_mb(); /* spin-unlock-wait is not a full memory barrier */ | |
05fa785c | 984 | raw_spin_unlock_wait(&rq->lock); |
ad474cac ON |
985 | } |
986 | ||
a9957449 | 987 | static void __task_rq_unlock(struct rq *rq) |
b29739f9 IM |
988 | __releases(rq->lock) |
989 | { | |
05fa785c | 990 | raw_spin_unlock(&rq->lock); |
b29739f9 IM |
991 | } |
992 | ||
70b97a7f | 993 | static inline void task_rq_unlock(struct rq *rq, unsigned long *flags) |
1da177e4 LT |
994 | __releases(rq->lock) |
995 | { | |
05fa785c | 996 | raw_spin_unlock_irqrestore(&rq->lock, *flags); |
1da177e4 LT |
997 | } |
998 | ||
1da177e4 | 999 | /* |
cc2a73b5 | 1000 | * this_rq_lock - lock this runqueue and disable interrupts. |
1da177e4 | 1001 | */ |
a9957449 | 1002 | static struct rq *this_rq_lock(void) |
1da177e4 LT |
1003 | __acquires(rq->lock) |
1004 | { | |
70b97a7f | 1005 | struct rq *rq; |
1da177e4 LT |
1006 | |
1007 | local_irq_disable(); | |
1008 | rq = this_rq(); | |
05fa785c | 1009 | raw_spin_lock(&rq->lock); |
1da177e4 LT |
1010 | |
1011 | return rq; | |
1012 | } | |
1013 | ||
8f4d37ec PZ |
1014 | #ifdef CONFIG_SCHED_HRTICK |
1015 | /* | |
1016 | * Use HR-timers to deliver accurate preemption points. | |
1017 | * | |
1018 | * Its all a bit involved since we cannot program an hrt while holding the | |
1019 | * rq->lock. So what we do is store a state in in rq->hrtick_* and ask for a | |
1020 | * reschedule event. | |
1021 | * | |
1022 | * When we get rescheduled we reprogram the hrtick_timer outside of the | |
1023 | * rq->lock. | |
1024 | */ | |
8f4d37ec PZ |
1025 | |
1026 | /* | |
1027 | * Use hrtick when: | |
1028 | * - enabled by features | |
1029 | * - hrtimer is actually high res | |
1030 | */ | |
1031 | static inline int hrtick_enabled(struct rq *rq) | |
1032 | { | |
1033 | if (!sched_feat(HRTICK)) | |
1034 | return 0; | |
ba42059f | 1035 | if (!cpu_active(cpu_of(rq))) |
b328ca18 | 1036 | return 0; |
8f4d37ec PZ |
1037 | return hrtimer_is_hres_active(&rq->hrtick_timer); |
1038 | } | |
1039 | ||
8f4d37ec PZ |
1040 | static void hrtick_clear(struct rq *rq) |
1041 | { | |
1042 | if (hrtimer_active(&rq->hrtick_timer)) | |
1043 | hrtimer_cancel(&rq->hrtick_timer); | |
1044 | } | |
1045 | ||
8f4d37ec PZ |
1046 | /* |
1047 | * High-resolution timer tick. | |
1048 | * Runs from hardirq context with interrupts disabled. | |
1049 | */ | |
1050 | static enum hrtimer_restart hrtick(struct hrtimer *timer) | |
1051 | { | |
1052 | struct rq *rq = container_of(timer, struct rq, hrtick_timer); | |
1053 | ||
1054 | WARN_ON_ONCE(cpu_of(rq) != smp_processor_id()); | |
1055 | ||
05fa785c | 1056 | raw_spin_lock(&rq->lock); |
3e51f33f | 1057 | update_rq_clock(rq); |
8f4d37ec | 1058 | rq->curr->sched_class->task_tick(rq, rq->curr, 1); |
05fa785c | 1059 | raw_spin_unlock(&rq->lock); |
8f4d37ec PZ |
1060 | |
1061 | return HRTIMER_NORESTART; | |
1062 | } | |
1063 | ||
95e904c7 | 1064 | #ifdef CONFIG_SMP |
31656519 PZ |
1065 | /* |
1066 | * called from hardirq (IPI) context | |
1067 | */ | |
1068 | static void __hrtick_start(void *arg) | |
b328ca18 | 1069 | { |
31656519 | 1070 | struct rq *rq = arg; |
b328ca18 | 1071 | |
05fa785c | 1072 | raw_spin_lock(&rq->lock); |
31656519 PZ |
1073 | hrtimer_restart(&rq->hrtick_timer); |
1074 | rq->hrtick_csd_pending = 0; | |
05fa785c | 1075 | raw_spin_unlock(&rq->lock); |
b328ca18 PZ |
1076 | } |
1077 | ||
31656519 PZ |
1078 | /* |
1079 | * Called to set the hrtick timer state. | |
1080 | * | |
1081 | * called with rq->lock held and irqs disabled | |
1082 | */ | |
1083 | static void hrtick_start(struct rq *rq, u64 delay) | |
b328ca18 | 1084 | { |
31656519 PZ |
1085 | struct hrtimer *timer = &rq->hrtick_timer; |
1086 | ktime_t time = ktime_add_ns(timer->base->get_time(), delay); | |
b328ca18 | 1087 | |
cc584b21 | 1088 | hrtimer_set_expires(timer, time); |
31656519 PZ |
1089 | |
1090 | if (rq == this_rq()) { | |
1091 | hrtimer_restart(timer); | |
1092 | } else if (!rq->hrtick_csd_pending) { | |
6e275637 | 1093 | __smp_call_function_single(cpu_of(rq), &rq->hrtick_csd, 0); |
31656519 PZ |
1094 | rq->hrtick_csd_pending = 1; |
1095 | } | |
b328ca18 PZ |
1096 | } |
1097 | ||
1098 | static int | |
1099 | hotplug_hrtick(struct notifier_block *nfb, unsigned long action, void *hcpu) | |
1100 | { | |
1101 | int cpu = (int)(long)hcpu; | |
1102 | ||
1103 | switch (action) { | |
1104 | case CPU_UP_CANCELED: | |
1105 | case CPU_UP_CANCELED_FROZEN: | |
1106 | case CPU_DOWN_PREPARE: | |
1107 | case CPU_DOWN_PREPARE_FROZEN: | |
1108 | case CPU_DEAD: | |
1109 | case CPU_DEAD_FROZEN: | |
31656519 | 1110 | hrtick_clear(cpu_rq(cpu)); |
b328ca18 PZ |
1111 | return NOTIFY_OK; |
1112 | } | |
1113 | ||
1114 | return NOTIFY_DONE; | |
1115 | } | |
1116 | ||
fa748203 | 1117 | static __init void init_hrtick(void) |
b328ca18 PZ |
1118 | { |
1119 | hotcpu_notifier(hotplug_hrtick, 0); | |
1120 | } | |
31656519 PZ |
1121 | #else |
1122 | /* | |
1123 | * Called to set the hrtick timer state. | |
1124 | * | |
1125 | * called with rq->lock held and irqs disabled | |
1126 | */ | |
1127 | static void hrtick_start(struct rq *rq, u64 delay) | |
1128 | { | |
7f1e2ca9 | 1129 | __hrtimer_start_range_ns(&rq->hrtick_timer, ns_to_ktime(delay), 0, |
5c333864 | 1130 | HRTIMER_MODE_REL_PINNED, 0); |
31656519 | 1131 | } |
b328ca18 | 1132 | |
006c75f1 | 1133 | static inline void init_hrtick(void) |
8f4d37ec | 1134 | { |
8f4d37ec | 1135 | } |
31656519 | 1136 | #endif /* CONFIG_SMP */ |
8f4d37ec | 1137 | |
31656519 | 1138 | static void init_rq_hrtick(struct rq *rq) |
8f4d37ec | 1139 | { |
31656519 PZ |
1140 | #ifdef CONFIG_SMP |
1141 | rq->hrtick_csd_pending = 0; | |
8f4d37ec | 1142 | |
31656519 PZ |
1143 | rq->hrtick_csd.flags = 0; |
1144 | rq->hrtick_csd.func = __hrtick_start; | |
1145 | rq->hrtick_csd.info = rq; | |
1146 | #endif | |
8f4d37ec | 1147 | |
31656519 PZ |
1148 | hrtimer_init(&rq->hrtick_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); |
1149 | rq->hrtick_timer.function = hrtick; | |
8f4d37ec | 1150 | } |
006c75f1 | 1151 | #else /* CONFIG_SCHED_HRTICK */ |
8f4d37ec PZ |
1152 | static inline void hrtick_clear(struct rq *rq) |
1153 | { | |
1154 | } | |
1155 | ||
8f4d37ec PZ |
1156 | static inline void init_rq_hrtick(struct rq *rq) |
1157 | { | |
1158 | } | |
1159 | ||
b328ca18 PZ |
1160 | static inline void init_hrtick(void) |
1161 | { | |
1162 | } | |
006c75f1 | 1163 | #endif /* CONFIG_SCHED_HRTICK */ |
8f4d37ec | 1164 | |
c24d20db IM |
1165 | /* |
1166 | * resched_task - mark a task 'to be rescheduled now'. | |
1167 | * | |
1168 | * On UP this means the setting of the need_resched flag, on SMP it | |
1169 | * might also involve a cross-CPU call to trigger the scheduler on | |
1170 | * the target CPU. | |
1171 | */ | |
1172 | #ifdef CONFIG_SMP | |
1173 | ||
1174 | #ifndef tsk_is_polling | |
1175 | #define tsk_is_polling(t) test_tsk_thread_flag(t, TIF_POLLING_NRFLAG) | |
1176 | #endif | |
1177 | ||
31656519 | 1178 | static void resched_task(struct task_struct *p) |
c24d20db IM |
1179 | { |
1180 | int cpu; | |
1181 | ||
05fa785c | 1182 | assert_raw_spin_locked(&task_rq(p)->lock); |
c24d20db | 1183 | |
5ed0cec0 | 1184 | if (test_tsk_need_resched(p)) |
c24d20db IM |
1185 | return; |
1186 | ||
5ed0cec0 | 1187 | set_tsk_need_resched(p); |
c24d20db IM |
1188 | |
1189 | cpu = task_cpu(p); | |
1190 | if (cpu == smp_processor_id()) | |
1191 | return; | |
1192 | ||
1193 | /* NEED_RESCHED must be visible before we test polling */ | |
1194 | smp_mb(); | |
1195 | if (!tsk_is_polling(p)) | |
1196 | smp_send_reschedule(cpu); | |
1197 | } | |
1198 | ||
1199 | static void resched_cpu(int cpu) | |
1200 | { | |
1201 | struct rq *rq = cpu_rq(cpu); | |
1202 | unsigned long flags; | |
1203 | ||
05fa785c | 1204 | if (!raw_spin_trylock_irqsave(&rq->lock, flags)) |
c24d20db IM |
1205 | return; |
1206 | resched_task(cpu_curr(cpu)); | |
05fa785c | 1207 | raw_spin_unlock_irqrestore(&rq->lock, flags); |
c24d20db | 1208 | } |
06d8308c TG |
1209 | |
1210 | #ifdef CONFIG_NO_HZ | |
1211 | /* | |
1212 | * When add_timer_on() enqueues a timer into the timer wheel of an | |
1213 | * idle CPU then this timer might expire before the next timer event | |
1214 | * which is scheduled to wake up that CPU. In case of a completely | |
1215 | * idle system the next event might even be infinite time into the | |
1216 | * future. wake_up_idle_cpu() ensures that the CPU is woken up and | |
1217 | * leaves the inner idle loop so the newly added timer is taken into | |
1218 | * account when the CPU goes back to idle and evaluates the timer | |
1219 | * wheel for the next timer event. | |
1220 | */ | |
1221 | void wake_up_idle_cpu(int cpu) | |
1222 | { | |
1223 | struct rq *rq = cpu_rq(cpu); | |
1224 | ||
1225 | if (cpu == smp_processor_id()) | |
1226 | return; | |
1227 | ||
1228 | /* | |
1229 | * This is safe, as this function is called with the timer | |
1230 | * wheel base lock of (cpu) held. When the CPU is on the way | |
1231 | * to idle and has not yet set rq->curr to idle then it will | |
1232 | * be serialized on the timer wheel base lock and take the new | |
1233 | * timer into account automatically. | |
1234 | */ | |
1235 | if (rq->curr != rq->idle) | |
1236 | return; | |
1237 | ||
1238 | /* | |
1239 | * We can set TIF_RESCHED on the idle task of the other CPU | |
1240 | * lockless. The worst case is that the other CPU runs the | |
1241 | * idle task through an additional NOOP schedule() | |
1242 | */ | |
5ed0cec0 | 1243 | set_tsk_need_resched(rq->idle); |
06d8308c TG |
1244 | |
1245 | /* NEED_RESCHED must be visible before we test polling */ | |
1246 | smp_mb(); | |
1247 | if (!tsk_is_polling(rq->idle)) | |
1248 | smp_send_reschedule(cpu); | |
1249 | } | |
6d6bc0ad | 1250 | #endif /* CONFIG_NO_HZ */ |
06d8308c | 1251 | |
e9e9250b PZ |
1252 | static u64 sched_avg_period(void) |
1253 | { | |
1254 | return (u64)sysctl_sched_time_avg * NSEC_PER_MSEC / 2; | |
1255 | } | |
1256 | ||
1257 | static void sched_avg_update(struct rq *rq) | |
1258 | { | |
1259 | s64 period = sched_avg_period(); | |
1260 | ||
1261 | while ((s64)(rq->clock - rq->age_stamp) > period) { | |
1262 | rq->age_stamp += period; | |
1263 | rq->rt_avg /= 2; | |
1264 | } | |
1265 | } | |
1266 | ||
1267 | static void sched_rt_avg_update(struct rq *rq, u64 rt_delta) | |
1268 | { | |
1269 | rq->rt_avg += rt_delta; | |
1270 | sched_avg_update(rq); | |
1271 | } | |
1272 | ||
6d6bc0ad | 1273 | #else /* !CONFIG_SMP */ |
31656519 | 1274 | static void resched_task(struct task_struct *p) |
c24d20db | 1275 | { |
05fa785c | 1276 | assert_raw_spin_locked(&task_rq(p)->lock); |
31656519 | 1277 | set_tsk_need_resched(p); |
c24d20db | 1278 | } |
e9e9250b PZ |
1279 | |
1280 | static void sched_rt_avg_update(struct rq *rq, u64 rt_delta) | |
1281 | { | |
1282 | } | |
6d6bc0ad | 1283 | #endif /* CONFIG_SMP */ |
c24d20db | 1284 | |
45bf76df IM |
1285 | #if BITS_PER_LONG == 32 |
1286 | # define WMULT_CONST (~0UL) | |
1287 | #else | |
1288 | # define WMULT_CONST (1UL << 32) | |
1289 | #endif | |
1290 | ||
1291 | #define WMULT_SHIFT 32 | |
1292 | ||
194081eb IM |
1293 | /* |
1294 | * Shift right and round: | |
1295 | */ | |
cf2ab469 | 1296 | #define SRR(x, y) (((x) + (1UL << ((y) - 1))) >> (y)) |
194081eb | 1297 | |
a7be37ac PZ |
1298 | /* |
1299 | * delta *= weight / lw | |
1300 | */ | |
cb1c4fc9 | 1301 | static unsigned long |
45bf76df IM |
1302 | calc_delta_mine(unsigned long delta_exec, unsigned long weight, |
1303 | struct load_weight *lw) | |
1304 | { | |
1305 | u64 tmp; | |
1306 | ||
7a232e03 LJ |
1307 | if (!lw->inv_weight) { |
1308 | if (BITS_PER_LONG > 32 && unlikely(lw->weight >= WMULT_CONST)) | |
1309 | lw->inv_weight = 1; | |
1310 | else | |
1311 | lw->inv_weight = 1 + (WMULT_CONST-lw->weight/2) | |
1312 | / (lw->weight+1); | |
1313 | } | |
45bf76df IM |
1314 | |
1315 | tmp = (u64)delta_exec * weight; | |
1316 | /* | |
1317 | * Check whether we'd overflow the 64-bit multiplication: | |
1318 | */ | |
194081eb | 1319 | if (unlikely(tmp > WMULT_CONST)) |
cf2ab469 | 1320 | tmp = SRR(SRR(tmp, WMULT_SHIFT/2) * lw->inv_weight, |
194081eb IM |
1321 | WMULT_SHIFT/2); |
1322 | else | |
cf2ab469 | 1323 | tmp = SRR(tmp * lw->inv_weight, WMULT_SHIFT); |
45bf76df | 1324 | |
ecf691da | 1325 | return (unsigned long)min(tmp, (u64)(unsigned long)LONG_MAX); |
45bf76df IM |
1326 | } |
1327 | ||
1091985b | 1328 | static inline void update_load_add(struct load_weight *lw, unsigned long inc) |
45bf76df IM |
1329 | { |
1330 | lw->weight += inc; | |
e89996ae | 1331 | lw->inv_weight = 0; |
45bf76df IM |
1332 | } |
1333 | ||
1091985b | 1334 | static inline void update_load_sub(struct load_weight *lw, unsigned long dec) |
45bf76df IM |
1335 | { |
1336 | lw->weight -= dec; | |
e89996ae | 1337 | lw->inv_weight = 0; |
45bf76df IM |
1338 | } |
1339 | ||
2dd73a4f PW |
1340 | /* |
1341 | * To aid in avoiding the subversion of "niceness" due to uneven distribution | |
1342 | * of tasks with abnormal "nice" values across CPUs the contribution that | |
1343 | * each task makes to its run queue's load is weighted according to its | |
41a2d6cf | 1344 | * scheduling class and "nice" value. For SCHED_NORMAL tasks this is just a |
2dd73a4f PW |
1345 | * scaled version of the new time slice allocation that they receive on time |
1346 | * slice expiry etc. | |
1347 | */ | |
1348 | ||
cce7ade8 PZ |
1349 | #define WEIGHT_IDLEPRIO 3 |
1350 | #define WMULT_IDLEPRIO 1431655765 | |
dd41f596 IM |
1351 | |
1352 | /* | |
1353 | * Nice levels are multiplicative, with a gentle 10% change for every | |
1354 | * nice level changed. I.e. when a CPU-bound task goes from nice 0 to | |
1355 | * nice 1, it will get ~10% less CPU time than another CPU-bound task | |
1356 | * that remained on nice 0. | |
1357 | * | |
1358 | * The "10% effect" is relative and cumulative: from _any_ nice level, | |
1359 | * if you go up 1 level, it's -10% CPU usage, if you go down 1 level | |
f9153ee6 IM |
1360 | * it's +10% CPU usage. (to achieve that we use a multiplier of 1.25. |
1361 | * If a task goes up by ~10% and another task goes down by ~10% then | |
1362 | * the relative distance between them is ~25%.) | |
dd41f596 IM |
1363 | */ |
1364 | static const int prio_to_weight[40] = { | |
254753dc IM |
1365 | /* -20 */ 88761, 71755, 56483, 46273, 36291, |
1366 | /* -15 */ 29154, 23254, 18705, 14949, 11916, | |
1367 | /* -10 */ 9548, 7620, 6100, 4904, 3906, | |
1368 | /* -5 */ 3121, 2501, 1991, 1586, 1277, | |
1369 | /* 0 */ 1024, 820, 655, 526, 423, | |
1370 | /* 5 */ 335, 272, 215, 172, 137, | |
1371 | /* 10 */ 110, 87, 70, 56, 45, | |
1372 | /* 15 */ 36, 29, 23, 18, 15, | |
dd41f596 IM |
1373 | }; |
1374 | ||
5714d2de IM |
1375 | /* |
1376 | * Inverse (2^32/x) values of the prio_to_weight[] array, precalculated. | |
1377 | * | |
1378 | * In cases where the weight does not change often, we can use the | |
1379 | * precalculated inverse to speed up arithmetics by turning divisions | |
1380 | * into multiplications: | |
1381 | */ | |
dd41f596 | 1382 | static const u32 prio_to_wmult[40] = { |
254753dc IM |
1383 | /* -20 */ 48388, 59856, 76040, 92818, 118348, |
1384 | /* -15 */ 147320, 184698, 229616, 287308, 360437, | |
1385 | /* -10 */ 449829, 563644, 704093, 875809, 1099582, | |
1386 | /* -5 */ 1376151, 1717300, 2157191, 2708050, 3363326, | |
1387 | /* 0 */ 4194304, 5237765, 6557202, 8165337, 10153587, | |
1388 | /* 5 */ 12820798, 15790321, 19976592, 24970740, 31350126, | |
1389 | /* 10 */ 39045157, 49367440, 61356676, 76695844, 95443717, | |
1390 | /* 15 */ 119304647, 148102320, 186737708, 238609294, 286331153, | |
dd41f596 | 1391 | }; |
2dd73a4f | 1392 | |
dd41f596 IM |
1393 | static void activate_task(struct rq *rq, struct task_struct *p, int wakeup); |
1394 | ||
1395 | /* | |
1396 | * runqueue iterator, to support SMP load-balancing between different | |
1397 | * scheduling classes, without having to expose their internal data | |
1398 | * structures to the load-balancing proper: | |
1399 | */ | |
1400 | struct rq_iterator { | |
1401 | void *arg; | |
1402 | struct task_struct *(*start)(void *); | |
1403 | struct task_struct *(*next)(void *); | |
1404 | }; | |
1405 | ||
e1d1484f PW |
1406 | #ifdef CONFIG_SMP |
1407 | static unsigned long | |
1408 | balance_tasks(struct rq *this_rq, int this_cpu, struct rq *busiest, | |
1409 | unsigned long max_load_move, struct sched_domain *sd, | |
1410 | enum cpu_idle_type idle, int *all_pinned, | |
1411 | int *this_best_prio, struct rq_iterator *iterator); | |
1412 | ||
1413 | static int | |
1414 | iter_move_one_task(struct rq *this_rq, int this_cpu, struct rq *busiest, | |
1415 | struct sched_domain *sd, enum cpu_idle_type idle, | |
1416 | struct rq_iterator *iterator); | |
e1d1484f | 1417 | #endif |
dd41f596 | 1418 | |
ef12fefa BR |
1419 | /* Time spent by the tasks of the cpu accounting group executing in ... */ |
1420 | enum cpuacct_stat_index { | |
1421 | CPUACCT_STAT_USER, /* ... user mode */ | |
1422 | CPUACCT_STAT_SYSTEM, /* ... kernel mode */ | |
1423 | ||
1424 | CPUACCT_STAT_NSTATS, | |
1425 | }; | |
1426 | ||
d842de87 SV |
1427 | #ifdef CONFIG_CGROUP_CPUACCT |
1428 | static void cpuacct_charge(struct task_struct *tsk, u64 cputime); | |
ef12fefa BR |
1429 | static void cpuacct_update_stats(struct task_struct *tsk, |
1430 | enum cpuacct_stat_index idx, cputime_t val); | |
d842de87 SV |
1431 | #else |
1432 | static inline void cpuacct_charge(struct task_struct *tsk, u64 cputime) {} | |
ef12fefa BR |
1433 | static inline void cpuacct_update_stats(struct task_struct *tsk, |
1434 | enum cpuacct_stat_index idx, cputime_t val) {} | |
d842de87 SV |
1435 | #endif |
1436 | ||
18d95a28 PZ |
1437 | static inline void inc_cpu_load(struct rq *rq, unsigned long load) |
1438 | { | |
1439 | update_load_add(&rq->load, load); | |
1440 | } | |
1441 | ||
1442 | static inline void dec_cpu_load(struct rq *rq, unsigned long load) | |
1443 | { | |
1444 | update_load_sub(&rq->load, load); | |
1445 | } | |
1446 | ||
7940ca36 | 1447 | #if (defined(CONFIG_SMP) && defined(CONFIG_FAIR_GROUP_SCHED)) || defined(CONFIG_RT_GROUP_SCHED) |
eb755805 | 1448 | typedef int (*tg_visitor)(struct task_group *, void *); |
c09595f6 PZ |
1449 | |
1450 | /* | |
1451 | * Iterate the full tree, calling @down when first entering a node and @up when | |
1452 | * leaving it for the final time. | |
1453 | */ | |
eb755805 | 1454 | static int walk_tg_tree(tg_visitor down, tg_visitor up, void *data) |
c09595f6 PZ |
1455 | { |
1456 | struct task_group *parent, *child; | |
eb755805 | 1457 | int ret; |
c09595f6 PZ |
1458 | |
1459 | rcu_read_lock(); | |
1460 | parent = &root_task_group; | |
1461 | down: | |
eb755805 PZ |
1462 | ret = (*down)(parent, data); |
1463 | if (ret) | |
1464 | goto out_unlock; | |
c09595f6 PZ |
1465 | list_for_each_entry_rcu(child, &parent->children, siblings) { |
1466 | parent = child; | |
1467 | goto down; | |
1468 | ||
1469 | up: | |
1470 | continue; | |
1471 | } | |
eb755805 PZ |
1472 | ret = (*up)(parent, data); |
1473 | if (ret) | |
1474 | goto out_unlock; | |
c09595f6 PZ |
1475 | |
1476 | child = parent; | |
1477 | parent = parent->parent; | |
1478 | if (parent) | |
1479 | goto up; | |
eb755805 | 1480 | out_unlock: |
c09595f6 | 1481 | rcu_read_unlock(); |
eb755805 PZ |
1482 | |
1483 | return ret; | |
c09595f6 PZ |
1484 | } |
1485 | ||
eb755805 PZ |
1486 | static int tg_nop(struct task_group *tg, void *data) |
1487 | { | |
1488 | return 0; | |
c09595f6 | 1489 | } |
eb755805 PZ |
1490 | #endif |
1491 | ||
1492 | #ifdef CONFIG_SMP | |
f5f08f39 PZ |
1493 | /* Used instead of source_load when we know the type == 0 */ |
1494 | static unsigned long weighted_cpuload(const int cpu) | |
1495 | { | |
1496 | return cpu_rq(cpu)->load.weight; | |
1497 | } | |
1498 | ||
1499 | /* | |
1500 | * Return a low guess at the load of a migration-source cpu weighted | |
1501 | * according to the scheduling class and "nice" value. | |
1502 | * | |
1503 | * We want to under-estimate the load of migration sources, to | |
1504 | * balance conservatively. | |
1505 | */ | |
1506 | static unsigned long source_load(int cpu, int type) | |
1507 | { | |
1508 | struct rq *rq = cpu_rq(cpu); | |
1509 | unsigned long total = weighted_cpuload(cpu); | |
1510 | ||
1511 | if (type == 0 || !sched_feat(LB_BIAS)) | |
1512 | return total; | |
1513 | ||
1514 | return min(rq->cpu_load[type-1], total); | |
1515 | } | |
1516 | ||
1517 | /* | |
1518 | * Return a high guess at the load of a migration-target cpu weighted | |
1519 | * according to the scheduling class and "nice" value. | |
1520 | */ | |
1521 | static unsigned long target_load(int cpu, int type) | |
1522 | { | |
1523 | struct rq *rq = cpu_rq(cpu); | |
1524 | unsigned long total = weighted_cpuload(cpu); | |
1525 | ||
1526 | if (type == 0 || !sched_feat(LB_BIAS)) | |
1527 | return total; | |
1528 | ||
1529 | return max(rq->cpu_load[type-1], total); | |
1530 | } | |
1531 | ||
ae154be1 PZ |
1532 | static struct sched_group *group_of(int cpu) |
1533 | { | |
1534 | struct sched_domain *sd = rcu_dereference(cpu_rq(cpu)->sd); | |
1535 | ||
1536 | if (!sd) | |
1537 | return NULL; | |
1538 | ||
1539 | return sd->groups; | |
1540 | } | |
1541 | ||
1542 | static unsigned long power_of(int cpu) | |
1543 | { | |
1544 | struct sched_group *group = group_of(cpu); | |
1545 | ||
1546 | if (!group) | |
1547 | return SCHED_LOAD_SCALE; | |
1548 | ||
1549 | return group->cpu_power; | |
1550 | } | |
1551 | ||
eb755805 PZ |
1552 | static int task_hot(struct task_struct *p, u64 now, struct sched_domain *sd); |
1553 | ||
1554 | static unsigned long cpu_avg_load_per_task(int cpu) | |
1555 | { | |
1556 | struct rq *rq = cpu_rq(cpu); | |
af6d596f | 1557 | unsigned long nr_running = ACCESS_ONCE(rq->nr_running); |
eb755805 | 1558 | |
4cd42620 SR |
1559 | if (nr_running) |
1560 | rq->avg_load_per_task = rq->load.weight / nr_running; | |
a2d47777 BS |
1561 | else |
1562 | rq->avg_load_per_task = 0; | |
eb755805 PZ |
1563 | |
1564 | return rq->avg_load_per_task; | |
1565 | } | |
1566 | ||
1567 | #ifdef CONFIG_FAIR_GROUP_SCHED | |
c09595f6 | 1568 | |
4a6cc4bd | 1569 | static __read_mostly unsigned long *update_shares_data; |
34d76c41 | 1570 | |
c09595f6 PZ |
1571 | static void __set_se_shares(struct sched_entity *se, unsigned long shares); |
1572 | ||
1573 | /* | |
1574 | * Calculate and set the cpu's group shares. | |
1575 | */ | |
34d76c41 PZ |
1576 | static void update_group_shares_cpu(struct task_group *tg, int cpu, |
1577 | unsigned long sd_shares, | |
1578 | unsigned long sd_rq_weight, | |
4a6cc4bd | 1579 | unsigned long *usd_rq_weight) |
18d95a28 | 1580 | { |
34d76c41 | 1581 | unsigned long shares, rq_weight; |
a5004278 | 1582 | int boost = 0; |
c09595f6 | 1583 | |
4a6cc4bd | 1584 | rq_weight = usd_rq_weight[cpu]; |
a5004278 PZ |
1585 | if (!rq_weight) { |
1586 | boost = 1; | |
1587 | rq_weight = NICE_0_LOAD; | |
1588 | } | |
c8cba857 | 1589 | |
c09595f6 | 1590 | /* |
a8af7246 PZ |
1591 | * \Sum_j shares_j * rq_weight_i |
1592 | * shares_i = ----------------------------- | |
1593 | * \Sum_j rq_weight_j | |
c09595f6 | 1594 | */ |
ec4e0e2f | 1595 | shares = (sd_shares * rq_weight) / sd_rq_weight; |
ffda12a1 | 1596 | shares = clamp_t(unsigned long, shares, MIN_SHARES, MAX_SHARES); |
c09595f6 | 1597 | |
ffda12a1 PZ |
1598 | if (abs(shares - tg->se[cpu]->load.weight) > |
1599 | sysctl_sched_shares_thresh) { | |
1600 | struct rq *rq = cpu_rq(cpu); | |
1601 | unsigned long flags; | |
c09595f6 | 1602 | |
05fa785c | 1603 | raw_spin_lock_irqsave(&rq->lock, flags); |
34d76c41 | 1604 | tg->cfs_rq[cpu]->rq_weight = boost ? 0 : rq_weight; |
a5004278 | 1605 | tg->cfs_rq[cpu]->shares = boost ? 0 : shares; |
ffda12a1 | 1606 | __set_se_shares(tg->se[cpu], shares); |
05fa785c | 1607 | raw_spin_unlock_irqrestore(&rq->lock, flags); |
ffda12a1 | 1608 | } |
18d95a28 | 1609 | } |
c09595f6 PZ |
1610 | |
1611 | /* | |
c8cba857 PZ |
1612 | * Re-compute the task group their per cpu shares over the given domain. |
1613 | * This needs to be done in a bottom-up fashion because the rq weight of a | |
1614 | * parent group depends on the shares of its child groups. | |
c09595f6 | 1615 | */ |
eb755805 | 1616 | static int tg_shares_up(struct task_group *tg, void *data) |
c09595f6 | 1617 | { |
cd8ad40d | 1618 | unsigned long weight, rq_weight = 0, sum_weight = 0, shares = 0; |
4a6cc4bd | 1619 | unsigned long *usd_rq_weight; |
eb755805 | 1620 | struct sched_domain *sd = data; |
34d76c41 | 1621 | unsigned long flags; |
c8cba857 | 1622 | int i; |
c09595f6 | 1623 | |
34d76c41 PZ |
1624 | if (!tg->se[0]) |
1625 | return 0; | |
1626 | ||
1627 | local_irq_save(flags); | |
4a6cc4bd | 1628 | usd_rq_weight = per_cpu_ptr(update_shares_data, smp_processor_id()); |
34d76c41 | 1629 | |
758b2cdc | 1630 | for_each_cpu(i, sched_domain_span(sd)) { |
34d76c41 | 1631 | weight = tg->cfs_rq[i]->load.weight; |
4a6cc4bd | 1632 | usd_rq_weight[i] = weight; |
34d76c41 | 1633 | |
cd8ad40d | 1634 | rq_weight += weight; |
ec4e0e2f KC |
1635 | /* |
1636 | * If there are currently no tasks on the cpu pretend there | |
1637 | * is one of average load so that when a new task gets to | |
1638 | * run here it will not get delayed by group starvation. | |
1639 | */ | |
ec4e0e2f KC |
1640 | if (!weight) |
1641 | weight = NICE_0_LOAD; | |
1642 | ||
cd8ad40d | 1643 | sum_weight += weight; |
c8cba857 | 1644 | shares += tg->cfs_rq[i]->shares; |
c09595f6 | 1645 | } |
c09595f6 | 1646 | |
cd8ad40d PZ |
1647 | if (!rq_weight) |
1648 | rq_weight = sum_weight; | |
1649 | ||
c8cba857 PZ |
1650 | if ((!shares && rq_weight) || shares > tg->shares) |
1651 | shares = tg->shares; | |
1652 | ||
1653 | if (!sd->parent || !(sd->parent->flags & SD_LOAD_BALANCE)) | |
1654 | shares = tg->shares; | |
c09595f6 | 1655 | |
758b2cdc | 1656 | for_each_cpu(i, sched_domain_span(sd)) |
4a6cc4bd | 1657 | update_group_shares_cpu(tg, i, shares, rq_weight, usd_rq_weight); |
34d76c41 PZ |
1658 | |
1659 | local_irq_restore(flags); | |
eb755805 PZ |
1660 | |
1661 | return 0; | |
c09595f6 PZ |
1662 | } |
1663 | ||
1664 | /* | |
c8cba857 PZ |
1665 | * Compute the cpu's hierarchical load factor for each task group. |
1666 | * This needs to be done in a top-down fashion because the load of a child | |
1667 | * group is a fraction of its parents load. | |
c09595f6 | 1668 | */ |
eb755805 | 1669 | static int tg_load_down(struct task_group *tg, void *data) |
c09595f6 | 1670 | { |
c8cba857 | 1671 | unsigned long load; |
eb755805 | 1672 | long cpu = (long)data; |
c09595f6 | 1673 | |
c8cba857 PZ |
1674 | if (!tg->parent) { |
1675 | load = cpu_rq(cpu)->load.weight; | |
1676 | } else { | |
1677 | load = tg->parent->cfs_rq[cpu]->h_load; | |
1678 | load *= tg->cfs_rq[cpu]->shares; | |
1679 | load /= tg->parent->cfs_rq[cpu]->load.weight + 1; | |
1680 | } | |
c09595f6 | 1681 | |
c8cba857 | 1682 | tg->cfs_rq[cpu]->h_load = load; |
c09595f6 | 1683 | |
eb755805 | 1684 | return 0; |
c09595f6 PZ |
1685 | } |
1686 | ||
c8cba857 | 1687 | static void update_shares(struct sched_domain *sd) |
4d8d595d | 1688 | { |
e7097159 PZ |
1689 | s64 elapsed; |
1690 | u64 now; | |
1691 | ||
1692 | if (root_task_group_empty()) | |
1693 | return; | |
1694 | ||
1695 | now = cpu_clock(raw_smp_processor_id()); | |
1696 | elapsed = now - sd->last_update; | |
2398f2c6 PZ |
1697 | |
1698 | if (elapsed >= (s64)(u64)sysctl_sched_shares_ratelimit) { | |
1699 | sd->last_update = now; | |
eb755805 | 1700 | walk_tg_tree(tg_nop, tg_shares_up, sd); |
2398f2c6 | 1701 | } |
4d8d595d PZ |
1702 | } |
1703 | ||
3e5459b4 PZ |
1704 | static void update_shares_locked(struct rq *rq, struct sched_domain *sd) |
1705 | { | |
e7097159 PZ |
1706 | if (root_task_group_empty()) |
1707 | return; | |
1708 | ||
05fa785c | 1709 | raw_spin_unlock(&rq->lock); |
3e5459b4 | 1710 | update_shares(sd); |
05fa785c | 1711 | raw_spin_lock(&rq->lock); |
3e5459b4 PZ |
1712 | } |
1713 | ||
eb755805 | 1714 | static void update_h_load(long cpu) |
c09595f6 | 1715 | { |
e7097159 PZ |
1716 | if (root_task_group_empty()) |
1717 | return; | |
1718 | ||
eb755805 | 1719 | walk_tg_tree(tg_load_down, tg_nop, (void *)cpu); |
c09595f6 PZ |
1720 | } |
1721 | ||
c09595f6 PZ |
1722 | #else |
1723 | ||
c8cba857 | 1724 | static inline void update_shares(struct sched_domain *sd) |
4d8d595d PZ |
1725 | { |
1726 | } | |
1727 | ||
3e5459b4 PZ |
1728 | static inline void update_shares_locked(struct rq *rq, struct sched_domain *sd) |
1729 | { | |
1730 | } | |
1731 | ||
18d95a28 PZ |
1732 | #endif |
1733 | ||
8f45e2b5 GH |
1734 | #ifdef CONFIG_PREEMPT |
1735 | ||
b78bb868 PZ |
1736 | static void double_rq_lock(struct rq *rq1, struct rq *rq2); |
1737 | ||
70574a99 | 1738 | /* |
8f45e2b5 GH |
1739 | * fair double_lock_balance: Safely acquires both rq->locks in a fair |
1740 | * way at the expense of forcing extra atomic operations in all | |
1741 | * invocations. This assures that the double_lock is acquired using the | |
1742 | * same underlying policy as the spinlock_t on this architecture, which | |
1743 | * reduces latency compared to the unfair variant below. However, it | |
1744 | * also adds more overhead and therefore may reduce throughput. | |
70574a99 | 1745 | */ |
8f45e2b5 GH |
1746 | static inline int _double_lock_balance(struct rq *this_rq, struct rq *busiest) |
1747 | __releases(this_rq->lock) | |
1748 | __acquires(busiest->lock) | |
1749 | __acquires(this_rq->lock) | |
1750 | { | |
05fa785c | 1751 | raw_spin_unlock(&this_rq->lock); |
8f45e2b5 GH |
1752 | double_rq_lock(this_rq, busiest); |
1753 | ||
1754 | return 1; | |
1755 | } | |
1756 | ||
1757 | #else | |
1758 | /* | |
1759 | * Unfair double_lock_balance: Optimizes throughput at the expense of | |
1760 | * latency by eliminating extra atomic operations when the locks are | |
1761 | * already in proper order on entry. This favors lower cpu-ids and will | |
1762 | * grant the double lock to lower cpus over higher ids under contention, | |
1763 | * regardless of entry order into the function. | |
1764 | */ | |
1765 | static int _double_lock_balance(struct rq *this_rq, struct rq *busiest) | |
70574a99 AD |
1766 | __releases(this_rq->lock) |
1767 | __acquires(busiest->lock) | |
1768 | __acquires(this_rq->lock) | |
1769 | { | |
1770 | int ret = 0; | |
1771 | ||
05fa785c | 1772 | if (unlikely(!raw_spin_trylock(&busiest->lock))) { |
70574a99 | 1773 | if (busiest < this_rq) { |
05fa785c TG |
1774 | raw_spin_unlock(&this_rq->lock); |
1775 | raw_spin_lock(&busiest->lock); | |
1776 | raw_spin_lock_nested(&this_rq->lock, | |
1777 | SINGLE_DEPTH_NESTING); | |
70574a99 AD |
1778 | ret = 1; |
1779 | } else | |
05fa785c TG |
1780 | raw_spin_lock_nested(&busiest->lock, |
1781 | SINGLE_DEPTH_NESTING); | |
70574a99 AD |
1782 | } |
1783 | return ret; | |
1784 | } | |
1785 | ||
8f45e2b5 GH |
1786 | #endif /* CONFIG_PREEMPT */ |
1787 | ||
1788 | /* | |
1789 | * double_lock_balance - lock the busiest runqueue, this_rq is locked already. | |
1790 | */ | |
1791 | static int double_lock_balance(struct rq *this_rq, struct rq *busiest) | |
1792 | { | |
1793 | if (unlikely(!irqs_disabled())) { | |
1794 | /* printk() doesn't work good under rq->lock */ | |
05fa785c | 1795 | raw_spin_unlock(&this_rq->lock); |
8f45e2b5 GH |
1796 | BUG_ON(1); |
1797 | } | |
1798 | ||
1799 | return _double_lock_balance(this_rq, busiest); | |
1800 | } | |
1801 | ||
70574a99 AD |
1802 | static inline void double_unlock_balance(struct rq *this_rq, struct rq *busiest) |
1803 | __releases(busiest->lock) | |
1804 | { | |
05fa785c | 1805 | raw_spin_unlock(&busiest->lock); |
70574a99 AD |
1806 | lock_set_subclass(&this_rq->lock.dep_map, 0, _RET_IP_); |
1807 | } | |
18d95a28 PZ |
1808 | #endif |
1809 | ||
30432094 | 1810 | #ifdef CONFIG_FAIR_GROUP_SCHED |
34e83e85 IM |
1811 | static void cfs_rq_set_shares(struct cfs_rq *cfs_rq, unsigned long shares) |
1812 | { | |
30432094 | 1813 | #ifdef CONFIG_SMP |
34e83e85 IM |
1814 | cfs_rq->shares = shares; |
1815 | #endif | |
1816 | } | |
30432094 | 1817 | #endif |
e7693a36 | 1818 | |
dce48a84 | 1819 | static void calc_load_account_active(struct rq *this_rq); |
0bcdcf28 | 1820 | static void update_sysctl(void); |
acb4a848 | 1821 | static int get_update_sysctl_factor(void); |
dce48a84 | 1822 | |
cd29fe6f PZ |
1823 | static inline void __set_task_cpu(struct task_struct *p, unsigned int cpu) |
1824 | { | |
1825 | set_task_rq(p, cpu); | |
1826 | #ifdef CONFIG_SMP | |
1827 | /* | |
1828 | * After ->cpu is set up to a new value, task_rq_lock(p, ...) can be | |
1829 | * successfuly executed on another CPU. We must ensure that updates of | |
1830 | * per-task data have been completed by this moment. | |
1831 | */ | |
1832 | smp_wmb(); | |
1833 | task_thread_info(p)->cpu = cpu; | |
1834 | #endif | |
1835 | } | |
dce48a84 | 1836 | |
dd41f596 | 1837 | #include "sched_stats.h" |
dd41f596 | 1838 | #include "sched_idletask.c" |
5522d5d5 IM |
1839 | #include "sched_fair.c" |
1840 | #include "sched_rt.c" | |
dd41f596 IM |
1841 | #ifdef CONFIG_SCHED_DEBUG |
1842 | # include "sched_debug.c" | |
1843 | #endif | |
1844 | ||
1845 | #define sched_class_highest (&rt_sched_class) | |
1f11eb6a GH |
1846 | #define for_each_class(class) \ |
1847 | for (class = sched_class_highest; class; class = class->next) | |
dd41f596 | 1848 | |
c09595f6 | 1849 | static void inc_nr_running(struct rq *rq) |
9c217245 IM |
1850 | { |
1851 | rq->nr_running++; | |
9c217245 IM |
1852 | } |
1853 | ||
c09595f6 | 1854 | static void dec_nr_running(struct rq *rq) |
9c217245 IM |
1855 | { |
1856 | rq->nr_running--; | |
9c217245 IM |
1857 | } |
1858 | ||
45bf76df IM |
1859 | static void set_load_weight(struct task_struct *p) |
1860 | { | |
1861 | if (task_has_rt_policy(p)) { | |
dd41f596 IM |
1862 | p->se.load.weight = prio_to_weight[0] * 2; |
1863 | p->se.load.inv_weight = prio_to_wmult[0] >> 1; | |
1864 | return; | |
1865 | } | |
45bf76df | 1866 | |
dd41f596 IM |
1867 | /* |
1868 | * SCHED_IDLE tasks get minimal weight: | |
1869 | */ | |
1870 | if (p->policy == SCHED_IDLE) { | |
1871 | p->se.load.weight = WEIGHT_IDLEPRIO; | |
1872 | p->se.load.inv_weight = WMULT_IDLEPRIO; | |
1873 | return; | |
1874 | } | |
71f8bd46 | 1875 | |
dd41f596 IM |
1876 | p->se.load.weight = prio_to_weight[p->static_prio - MAX_RT_PRIO]; |
1877 | p->se.load.inv_weight = prio_to_wmult[p->static_prio - MAX_RT_PRIO]; | |
71f8bd46 IM |
1878 | } |
1879 | ||
2087a1ad GH |
1880 | static void update_avg(u64 *avg, u64 sample) |
1881 | { | |
1882 | s64 diff = sample - *avg; | |
1883 | *avg += diff >> 3; | |
1884 | } | |
1885 | ||
8159f87e | 1886 | static void enqueue_task(struct rq *rq, struct task_struct *p, int wakeup) |
71f8bd46 | 1887 | { |
831451ac PZ |
1888 | if (wakeup) |
1889 | p->se.start_runtime = p->se.sum_exec_runtime; | |
1890 | ||
dd41f596 | 1891 | sched_info_queued(p); |
fd390f6a | 1892 | p->sched_class->enqueue_task(rq, p, wakeup); |
dd41f596 | 1893 | p->se.on_rq = 1; |
71f8bd46 IM |
1894 | } |
1895 | ||
69be72c1 | 1896 | static void dequeue_task(struct rq *rq, struct task_struct *p, int sleep) |
71f8bd46 | 1897 | { |
831451ac PZ |
1898 | if (sleep) { |
1899 | if (p->se.last_wakeup) { | |
1900 | update_avg(&p->se.avg_overlap, | |
1901 | p->se.sum_exec_runtime - p->se.last_wakeup); | |
1902 | p->se.last_wakeup = 0; | |
1903 | } else { | |
1904 | update_avg(&p->se.avg_wakeup, | |
1905 | sysctl_sched_wakeup_granularity); | |
1906 | } | |
2087a1ad GH |
1907 | } |
1908 | ||
46ac22ba | 1909 | sched_info_dequeued(p); |
f02231e5 | 1910 | p->sched_class->dequeue_task(rq, p, sleep); |
dd41f596 | 1911 | p->se.on_rq = 0; |
71f8bd46 IM |
1912 | } |
1913 | ||
14531189 | 1914 | /* |
dd41f596 | 1915 | * __normal_prio - return the priority that is based on the static prio |
14531189 | 1916 | */ |
14531189 IM |
1917 | static inline int __normal_prio(struct task_struct *p) |
1918 | { | |
dd41f596 | 1919 | return p->static_prio; |
14531189 IM |
1920 | } |
1921 | ||
b29739f9 IM |
1922 | /* |
1923 | * Calculate the expected normal priority: i.e. priority | |
1924 | * without taking RT-inheritance into account. Might be | |
1925 | * boosted by interactivity modifiers. Changes upon fork, | |
1926 | * setprio syscalls, and whenever the interactivity | |
1927 | * estimator recalculates. | |
1928 | */ | |
36c8b586 | 1929 | static inline int normal_prio(struct task_struct *p) |
b29739f9 IM |
1930 | { |
1931 | int prio; | |
1932 | ||
e05606d3 | 1933 | if (task_has_rt_policy(p)) |
b29739f9 IM |
1934 | prio = MAX_RT_PRIO-1 - p->rt_priority; |
1935 | else | |
1936 | prio = __normal_prio(p); | |
1937 | return prio; | |
1938 | } | |
1939 | ||
1940 | /* | |
1941 | * Calculate the current priority, i.e. the priority | |
1942 | * taken into account by the scheduler. This value might | |
1943 | * be boosted by RT tasks, or might be boosted by | |
1944 | * interactivity modifiers. Will be RT if the task got | |
1945 | * RT-boosted. If not then it returns p->normal_prio. | |
1946 | */ | |
36c8b586 | 1947 | static int effective_prio(struct task_struct *p) |
b29739f9 IM |
1948 | { |
1949 | p->normal_prio = normal_prio(p); | |
1950 | /* | |
1951 | * If we are RT tasks or we were boosted to RT priority, | |
1952 | * keep the priority unchanged. Otherwise, update priority | |
1953 | * to the normal priority: | |
1954 | */ | |
1955 | if (!rt_prio(p->prio)) | |
1956 | return p->normal_prio; | |
1957 | return p->prio; | |
1958 | } | |
1959 | ||
1da177e4 | 1960 | /* |
dd41f596 | 1961 | * activate_task - move a task to the runqueue. |
1da177e4 | 1962 | */ |
dd41f596 | 1963 | static void activate_task(struct rq *rq, struct task_struct *p, int wakeup) |
1da177e4 | 1964 | { |
d9514f6c | 1965 | if (task_contributes_to_load(p)) |
dd41f596 | 1966 | rq->nr_uninterruptible--; |
1da177e4 | 1967 | |
8159f87e | 1968 | enqueue_task(rq, p, wakeup); |
c09595f6 | 1969 | inc_nr_running(rq); |
1da177e4 LT |
1970 | } |
1971 | ||
1da177e4 LT |
1972 | /* |
1973 | * deactivate_task - remove a task from the runqueue. | |
1974 | */ | |
2e1cb74a | 1975 | static void deactivate_task(struct rq *rq, struct task_struct *p, int sleep) |
1da177e4 | 1976 | { |
d9514f6c | 1977 | if (task_contributes_to_load(p)) |
dd41f596 IM |
1978 | rq->nr_uninterruptible++; |
1979 | ||
69be72c1 | 1980 | dequeue_task(rq, p, sleep); |
c09595f6 | 1981 | dec_nr_running(rq); |
1da177e4 LT |
1982 | } |
1983 | ||
1da177e4 LT |
1984 | /** |
1985 | * task_curr - is this task currently executing on a CPU? | |
1986 | * @p: the task in question. | |
1987 | */ | |
36c8b586 | 1988 | inline int task_curr(const struct task_struct *p) |
1da177e4 LT |
1989 | { |
1990 | return cpu_curr(task_cpu(p)) == p; | |
1991 | } | |
1992 | ||
cb469845 SR |
1993 | static inline void check_class_changed(struct rq *rq, struct task_struct *p, |
1994 | const struct sched_class *prev_class, | |
1995 | int oldprio, int running) | |
1996 | { | |
1997 | if (prev_class != p->sched_class) { | |
1998 | if (prev_class->switched_from) | |
1999 | prev_class->switched_from(rq, p, running); | |
2000 | p->sched_class->switched_to(rq, p, running); | |
2001 | } else | |
2002 | p->sched_class->prio_changed(rq, p, oldprio, running); | |
2003 | } | |
2004 | ||
1da177e4 | 2005 | #ifdef CONFIG_SMP |
cc367732 IM |
2006 | /* |
2007 | * Is this task likely cache-hot: | |
2008 | */ | |
e7693a36 | 2009 | static int |
cc367732 IM |
2010 | task_hot(struct task_struct *p, u64 now, struct sched_domain *sd) |
2011 | { | |
2012 | s64 delta; | |
2013 | ||
e6c8fba7 PZ |
2014 | if (p->sched_class != &fair_sched_class) |
2015 | return 0; | |
2016 | ||
f540a608 IM |
2017 | /* |
2018 | * Buddy candidates are cache hot: | |
2019 | */ | |
f685ceac | 2020 | if (sched_feat(CACHE_HOT_BUDDY) && this_rq()->nr_running && |
4793241b PZ |
2021 | (&p->se == cfs_rq_of(&p->se)->next || |
2022 | &p->se == cfs_rq_of(&p->se)->last)) | |
f540a608 IM |
2023 | return 1; |
2024 | ||
6bc1665b IM |
2025 | if (sysctl_sched_migration_cost == -1) |
2026 | return 1; | |
2027 | if (sysctl_sched_migration_cost == 0) | |
2028 | return 0; | |
2029 | ||
cc367732 IM |
2030 | delta = now - p->se.exec_start; |
2031 | ||
2032 | return delta < (s64)sysctl_sched_migration_cost; | |
2033 | } | |
2034 | ||
dd41f596 | 2035 | void set_task_cpu(struct task_struct *p, unsigned int new_cpu) |
c65cc870 | 2036 | { |
e2912009 PZ |
2037 | #ifdef CONFIG_SCHED_DEBUG |
2038 | /* | |
2039 | * We should never call set_task_cpu() on a blocked task, | |
2040 | * ttwu() will sort out the placement. | |
2041 | */ | |
077614ee PZ |
2042 | WARN_ON_ONCE(p->state != TASK_RUNNING && p->state != TASK_WAKING && |
2043 | !(task_thread_info(p)->preempt_count & PREEMPT_ACTIVE)); | |
e2912009 PZ |
2044 | #endif |
2045 | ||
de1d7286 | 2046 | trace_sched_migrate_task(p, new_cpu); |
cbc34ed1 | 2047 | |
0c69774e PZ |
2048 | if (task_cpu(p) != new_cpu) { |
2049 | p->se.nr_migrations++; | |
2050 | perf_sw_event(PERF_COUNT_SW_CPU_MIGRATIONS, 1, 1, NULL, 0); | |
2051 | } | |
dd41f596 IM |
2052 | |
2053 | __set_task_cpu(p, new_cpu); | |
c65cc870 IM |
2054 | } |
2055 | ||
70b97a7f | 2056 | struct migration_req { |
1da177e4 | 2057 | struct list_head list; |
1da177e4 | 2058 | |
36c8b586 | 2059 | struct task_struct *task; |
1da177e4 LT |
2060 | int dest_cpu; |
2061 | ||
1da177e4 | 2062 | struct completion done; |
70b97a7f | 2063 | }; |
1da177e4 LT |
2064 | |
2065 | /* | |
2066 | * The task's runqueue lock must be held. | |
2067 | * Returns true if you have to wait for migration thread. | |
2068 | */ | |
36c8b586 | 2069 | static int |
70b97a7f | 2070 | migrate_task(struct task_struct *p, int dest_cpu, struct migration_req *req) |
1da177e4 | 2071 | { |
70b97a7f | 2072 | struct rq *rq = task_rq(p); |
1da177e4 LT |
2073 | |
2074 | /* | |
2075 | * If the task is not on a runqueue (and not running), then | |
e2912009 | 2076 | * the next wake-up will properly place the task. |
1da177e4 | 2077 | */ |
e2912009 | 2078 | if (!p->se.on_rq && !task_running(rq, p)) |
1da177e4 | 2079 | return 0; |
1da177e4 LT |
2080 | |
2081 | init_completion(&req->done); | |
1da177e4 LT |
2082 | req->task = p; |
2083 | req->dest_cpu = dest_cpu; | |
2084 | list_add(&req->list, &rq->migration_queue); | |
48f24c4d | 2085 | |
1da177e4 LT |
2086 | return 1; |
2087 | } | |
2088 | ||
a26b89f0 MM |
2089 | /* |
2090 | * wait_task_context_switch - wait for a thread to complete at least one | |
2091 | * context switch. | |
2092 | * | |
2093 | * @p must not be current. | |
2094 | */ | |
2095 | void wait_task_context_switch(struct task_struct *p) | |
2096 | { | |
2097 | unsigned long nvcsw, nivcsw, flags; | |
2098 | int running; | |
2099 | struct rq *rq; | |
2100 | ||
2101 | nvcsw = p->nvcsw; | |
2102 | nivcsw = p->nivcsw; | |
2103 | for (;;) { | |
2104 | /* | |
2105 | * The runqueue is assigned before the actual context | |
2106 | * switch. We need to take the runqueue lock. | |
2107 | * | |
2108 | * We could check initially without the lock but it is | |
2109 | * very likely that we need to take the lock in every | |
2110 | * iteration. | |
2111 | */ | |
2112 | rq = task_rq_lock(p, &flags); | |
2113 | running = task_running(rq, p); | |
2114 | task_rq_unlock(rq, &flags); | |
2115 | ||
2116 | if (likely(!running)) | |
2117 | break; | |
2118 | /* | |
2119 | * The switch count is incremented before the actual | |
2120 | * context switch. We thus wait for two switches to be | |
2121 | * sure at least one completed. | |
2122 | */ | |
2123 | if ((p->nvcsw - nvcsw) > 1) | |
2124 | break; | |
2125 | if ((p->nivcsw - nivcsw) > 1) | |
2126 | break; | |
2127 | ||
2128 | cpu_relax(); | |
2129 | } | |
2130 | } | |
2131 | ||
1da177e4 LT |
2132 | /* |
2133 | * wait_task_inactive - wait for a thread to unschedule. | |
2134 | * | |
85ba2d86 RM |
2135 | * If @match_state is nonzero, it's the @p->state value just checked and |
2136 | * not expected to change. If it changes, i.e. @p might have woken up, | |
2137 | * then return zero. When we succeed in waiting for @p to be off its CPU, | |
2138 | * we return a positive number (its total switch count). If a second call | |
2139 | * a short while later returns the same number, the caller can be sure that | |
2140 | * @p has remained unscheduled the whole time. | |
2141 | * | |
1da177e4 LT |
2142 | * The caller must ensure that the task *will* unschedule sometime soon, |
2143 | * else this function might spin for a *long* time. This function can't | |
2144 | * be called with interrupts off, or it may introduce deadlock with | |
2145 | * smp_call_function() if an IPI is sent by the same process we are | |
2146 | * waiting to become inactive. | |
2147 | */ | |
85ba2d86 | 2148 | unsigned long wait_task_inactive(struct task_struct *p, long match_state) |
1da177e4 LT |
2149 | { |
2150 | unsigned long flags; | |
dd41f596 | 2151 | int running, on_rq; |
85ba2d86 | 2152 | unsigned long ncsw; |
70b97a7f | 2153 | struct rq *rq; |
1da177e4 | 2154 | |
3a5c359a AK |
2155 | for (;;) { |
2156 | /* | |
2157 | * We do the initial early heuristics without holding | |
2158 | * any task-queue locks at all. We'll only try to get | |
2159 | * the runqueue lock when things look like they will | |
2160 | * work out! | |
2161 | */ | |
2162 | rq = task_rq(p); | |
fa490cfd | 2163 | |
3a5c359a AK |
2164 | /* |
2165 | * If the task is actively running on another CPU | |
2166 | * still, just relax and busy-wait without holding | |
2167 | * any locks. | |
2168 | * | |
2169 | * NOTE! Since we don't hold any locks, it's not | |
2170 | * even sure that "rq" stays as the right runqueue! | |
2171 | * But we don't care, since "task_running()" will | |
2172 | * return false if the runqueue has changed and p | |
2173 | * is actually now running somewhere else! | |
2174 | */ | |
85ba2d86 RM |
2175 | while (task_running(rq, p)) { |
2176 | if (match_state && unlikely(p->state != match_state)) | |
2177 | return 0; | |
3a5c359a | 2178 | cpu_relax(); |
85ba2d86 | 2179 | } |
fa490cfd | 2180 | |
3a5c359a AK |
2181 | /* |
2182 | * Ok, time to look more closely! We need the rq | |
2183 | * lock now, to be *sure*. If we're wrong, we'll | |
2184 | * just go back and repeat. | |
2185 | */ | |
2186 | rq = task_rq_lock(p, &flags); | |
0a16b607 | 2187 | trace_sched_wait_task(rq, p); |
3a5c359a AK |
2188 | running = task_running(rq, p); |
2189 | on_rq = p->se.on_rq; | |
85ba2d86 | 2190 | ncsw = 0; |
f31e11d8 | 2191 | if (!match_state || p->state == match_state) |
93dcf55f | 2192 | ncsw = p->nvcsw | LONG_MIN; /* sets MSB */ |
3a5c359a | 2193 | task_rq_unlock(rq, &flags); |
fa490cfd | 2194 | |
85ba2d86 RM |
2195 | /* |
2196 | * If it changed from the expected state, bail out now. | |
2197 | */ | |
2198 | if (unlikely(!ncsw)) | |
2199 | break; | |
2200 | ||
3a5c359a AK |
2201 | /* |
2202 | * Was it really running after all now that we | |
2203 | * checked with the proper locks actually held? | |
2204 | * | |
2205 | * Oops. Go back and try again.. | |
2206 | */ | |
2207 | if (unlikely(running)) { | |
2208 | cpu_relax(); | |
2209 | continue; | |
2210 | } | |
fa490cfd | 2211 | |
3a5c359a AK |
2212 | /* |
2213 | * It's not enough that it's not actively running, | |
2214 | * it must be off the runqueue _entirely_, and not | |
2215 | * preempted! | |
2216 | * | |
80dd99b3 | 2217 | * So if it was still runnable (but just not actively |
3a5c359a AK |
2218 | * running right now), it's preempted, and we should |
2219 | * yield - it could be a while. | |
2220 | */ | |
2221 | if (unlikely(on_rq)) { | |
2222 | schedule_timeout_uninterruptible(1); | |
2223 | continue; | |
2224 | } | |
fa490cfd | 2225 | |
3a5c359a AK |
2226 | /* |
2227 | * Ahh, all good. It wasn't running, and it wasn't | |
2228 | * runnable, which means that it will never become | |
2229 | * running in the future either. We're all done! | |
2230 | */ | |
2231 | break; | |
2232 | } | |
85ba2d86 RM |
2233 | |
2234 | return ncsw; | |
1da177e4 LT |
2235 | } |
2236 | ||
2237 | /*** | |
2238 | * kick_process - kick a running thread to enter/exit the kernel | |
2239 | * @p: the to-be-kicked thread | |
2240 | * | |
2241 | * Cause a process which is running on another CPU to enter | |
2242 | * kernel-mode, without any delay. (to get signals handled.) | |
2243 | * | |
2244 | * NOTE: this function doesnt have to take the runqueue lock, | |
2245 | * because all it wants to ensure is that the remote task enters | |
2246 | * the kernel. If the IPI races and the task has been migrated | |
2247 | * to another CPU then no harm is done and the purpose has been | |
2248 | * achieved as well. | |
2249 | */ | |
36c8b586 | 2250 | void kick_process(struct task_struct *p) |
1da177e4 LT |
2251 | { |
2252 | int cpu; | |
2253 | ||
2254 | preempt_disable(); | |
2255 | cpu = task_cpu(p); | |
2256 | if ((cpu != smp_processor_id()) && task_curr(p)) | |
2257 | smp_send_reschedule(cpu); | |
2258 | preempt_enable(); | |
2259 | } | |
b43e3521 | 2260 | EXPORT_SYMBOL_GPL(kick_process); |
476d139c | 2261 | #endif /* CONFIG_SMP */ |
1da177e4 | 2262 | |
0793a61d TG |
2263 | /** |
2264 | * task_oncpu_function_call - call a function on the cpu on which a task runs | |
2265 | * @p: the task to evaluate | |
2266 | * @func: the function to be called | |
2267 | * @info: the function call argument | |
2268 | * | |
2269 | * Calls the function @func when the task is currently running. This might | |
2270 | * be on the current CPU, which just calls the function directly | |
2271 | */ | |
2272 | void task_oncpu_function_call(struct task_struct *p, | |
2273 | void (*func) (void *info), void *info) | |
2274 | { | |
2275 | int cpu; | |
2276 | ||
2277 | preempt_disable(); | |
2278 | cpu = task_cpu(p); | |
2279 | if (task_curr(p)) | |
2280 | smp_call_function_single(cpu, func, info, 1); | |
2281 | preempt_enable(); | |
2282 | } | |
2283 | ||
970b13ba | 2284 | #ifdef CONFIG_SMP |
5da9a0fb PZ |
2285 | static int select_fallback_rq(int cpu, struct task_struct *p) |
2286 | { | |
2287 | int dest_cpu; | |
2288 | const struct cpumask *nodemask = cpumask_of_node(cpu_to_node(cpu)); | |
2289 | ||
2290 | /* Look for allowed, online CPU in same node. */ | |
2291 | for_each_cpu_and(dest_cpu, nodemask, cpu_active_mask) | |
2292 | if (cpumask_test_cpu(dest_cpu, &p->cpus_allowed)) | |
2293 | return dest_cpu; | |
2294 | ||
2295 | /* Any allowed, online CPU? */ | |
2296 | dest_cpu = cpumask_any_and(&p->cpus_allowed, cpu_active_mask); | |
2297 | if (dest_cpu < nr_cpu_ids) | |
2298 | return dest_cpu; | |
2299 | ||
2300 | /* No more Mr. Nice Guy. */ | |
2301 | if (dest_cpu >= nr_cpu_ids) { | |
2302 | rcu_read_lock(); | |
2303 | cpuset_cpus_allowed_locked(p, &p->cpus_allowed); | |
2304 | rcu_read_unlock(); | |
2305 | dest_cpu = cpumask_any_and(cpu_active_mask, &p->cpus_allowed); | |
2306 | ||
2307 | /* | |
2308 | * Don't tell them about moving exiting tasks or | |
2309 | * kernel threads (both mm NULL), since they never | |
2310 | * leave kernel. | |
2311 | */ | |
2312 | if (p->mm && printk_ratelimit()) { | |
2313 | printk(KERN_INFO "process %d (%s) no " | |
2314 | "longer affine to cpu%d\n", | |
2315 | task_pid_nr(p), p->comm, cpu); | |
2316 | } | |
2317 | } | |
2318 | ||
2319 | return dest_cpu; | |
2320 | } | |
2321 | ||
e2912009 | 2322 | /* |
fabf318e PZ |
2323 | * Gets called from 3 sites (exec, fork, wakeup), since it is called without |
2324 | * holding rq->lock we need to ensure ->cpus_allowed is stable, this is done | |
2325 | * by: | |
e2912009 | 2326 | * |
fabf318e PZ |
2327 | * exec: is unstable, retry loop |
2328 | * fork & wake-up: serialize ->cpus_allowed against TASK_WAKING | |
e2912009 | 2329 | */ |
970b13ba PZ |
2330 | static inline |
2331 | int select_task_rq(struct task_struct *p, int sd_flags, int wake_flags) | |
2332 | { | |
e2912009 PZ |
2333 | int cpu = p->sched_class->select_task_rq(p, sd_flags, wake_flags); |
2334 | ||
2335 | /* | |
2336 | * In order not to call set_task_cpu() on a blocking task we need | |
2337 | * to rely on ttwu() to place the task on a valid ->cpus_allowed | |
2338 | * cpu. | |
2339 | * | |
2340 | * Since this is common to all placement strategies, this lives here. | |
2341 | * | |
2342 | * [ this allows ->select_task() to simply return task_cpu(p) and | |
2343 | * not worry about this generic constraint ] | |
2344 | */ | |
2345 | if (unlikely(!cpumask_test_cpu(cpu, &p->cpus_allowed) || | |
70f11205 | 2346 | !cpu_online(cpu))) |
5da9a0fb | 2347 | cpu = select_fallback_rq(task_cpu(p), p); |
e2912009 PZ |
2348 | |
2349 | return cpu; | |
970b13ba PZ |
2350 | } |
2351 | #endif | |
2352 | ||
1da177e4 LT |
2353 | /*** |
2354 | * try_to_wake_up - wake up a thread | |
2355 | * @p: the to-be-woken-up thread | |
2356 | * @state: the mask of task states that can be woken | |
2357 | * @sync: do a synchronous wakeup? | |
2358 | * | |
2359 | * Put it on the run-queue if it's not already there. The "current" | |
2360 | * thread is always on the run-queue (except when the actual | |
2361 | * re-schedule is in progress), and as such you're allowed to do | |
2362 | * the simpler "current->state = TASK_RUNNING" to mark yourself | |
2363 | * runnable without the overhead of this. | |
2364 | * | |
2365 | * returns failure only if the task is already active. | |
2366 | */ | |
7d478721 PZ |
2367 | static int try_to_wake_up(struct task_struct *p, unsigned int state, |
2368 | int wake_flags) | |
1da177e4 | 2369 | { |
cc367732 | 2370 | int cpu, orig_cpu, this_cpu, success = 0; |
1da177e4 | 2371 | unsigned long flags; |
f5dc3753 | 2372 | struct rq *rq, *orig_rq; |
1da177e4 | 2373 | |
b85d0667 | 2374 | if (!sched_feat(SYNC_WAKEUPS)) |
7d478721 | 2375 | wake_flags &= ~WF_SYNC; |
2398f2c6 | 2376 | |
e9c84311 | 2377 | this_cpu = get_cpu(); |
2398f2c6 | 2378 | |
04e2f174 | 2379 | smp_wmb(); |
f5dc3753 | 2380 | rq = orig_rq = task_rq_lock(p, &flags); |
03e89e45 | 2381 | update_rq_clock(rq); |
e9c84311 | 2382 | if (!(p->state & state)) |
1da177e4 LT |
2383 | goto out; |
2384 | ||
dd41f596 | 2385 | if (p->se.on_rq) |
1da177e4 LT |
2386 | goto out_running; |
2387 | ||
2388 | cpu = task_cpu(p); | |
cc367732 | 2389 | orig_cpu = cpu; |
1da177e4 LT |
2390 | |
2391 | #ifdef CONFIG_SMP | |
2392 | if (unlikely(task_running(rq, p))) | |
2393 | goto out_activate; | |
2394 | ||
e9c84311 PZ |
2395 | /* |
2396 | * In order to handle concurrent wakeups and release the rq->lock | |
2397 | * we put the task in TASK_WAKING state. | |
eb24073b IM |
2398 | * |
2399 | * First fix up the nr_uninterruptible count: | |
e9c84311 | 2400 | */ |
eb24073b IM |
2401 | if (task_contributes_to_load(p)) |
2402 | rq->nr_uninterruptible--; | |
e9c84311 | 2403 | p->state = TASK_WAKING; |
efbbd05a PZ |
2404 | |
2405 | if (p->sched_class->task_waking) | |
2406 | p->sched_class->task_waking(rq, p); | |
2407 | ||
ab19cb23 | 2408 | __task_rq_unlock(rq); |
e9c84311 | 2409 | |
970b13ba | 2410 | cpu = select_task_rq(p, SD_BALANCE_WAKE, wake_flags); |
ab19cb23 | 2411 | if (cpu != orig_cpu) |
5d2f5a61 | 2412 | set_task_cpu(p, cpu); |
ab19cb23 PZ |
2413 | |
2414 | rq = __task_rq_lock(p); | |
2415 | update_rq_clock(rq); | |
f5dc3753 | 2416 | |
e9c84311 PZ |
2417 | WARN_ON(p->state != TASK_WAKING); |
2418 | cpu = task_cpu(p); | |
1da177e4 | 2419 | |
e7693a36 GH |
2420 | #ifdef CONFIG_SCHEDSTATS |
2421 | schedstat_inc(rq, ttwu_count); | |
2422 | if (cpu == this_cpu) | |
2423 | schedstat_inc(rq, ttwu_local); | |
2424 | else { | |
2425 | struct sched_domain *sd; | |
2426 | for_each_domain(this_cpu, sd) { | |
758b2cdc | 2427 | if (cpumask_test_cpu(cpu, sched_domain_span(sd))) { |
e7693a36 GH |
2428 | schedstat_inc(sd, ttwu_wake_remote); |
2429 | break; | |
2430 | } | |
2431 | } | |
2432 | } | |
6d6bc0ad | 2433 | #endif /* CONFIG_SCHEDSTATS */ |
e7693a36 | 2434 | |
1da177e4 LT |
2435 | out_activate: |
2436 | #endif /* CONFIG_SMP */ | |
cc367732 | 2437 | schedstat_inc(p, se.nr_wakeups); |
7d478721 | 2438 | if (wake_flags & WF_SYNC) |
cc367732 IM |
2439 | schedstat_inc(p, se.nr_wakeups_sync); |
2440 | if (orig_cpu != cpu) | |
2441 | schedstat_inc(p, se.nr_wakeups_migrate); | |
2442 | if (cpu == this_cpu) | |
2443 | schedstat_inc(p, se.nr_wakeups_local); | |
2444 | else | |
2445 | schedstat_inc(p, se.nr_wakeups_remote); | |
dd41f596 | 2446 | activate_task(rq, p, 1); |
1da177e4 LT |
2447 | success = 1; |
2448 | ||
831451ac PZ |
2449 | /* |
2450 | * Only attribute actual wakeups done by this task. | |
2451 | */ | |
2452 | if (!in_interrupt()) { | |
2453 | struct sched_entity *se = ¤t->se; | |
2454 | u64 sample = se->sum_exec_runtime; | |
2455 | ||
2456 | if (se->last_wakeup) | |
2457 | sample -= se->last_wakeup; | |
2458 | else | |
2459 | sample -= se->start_runtime; | |
2460 | update_avg(&se->avg_wakeup, sample); | |
2461 | ||
2462 | se->last_wakeup = se->sum_exec_runtime; | |
2463 | } | |
2464 | ||
1da177e4 | 2465 | out_running: |
468a15bb | 2466 | trace_sched_wakeup(rq, p, success); |
7d478721 | 2467 | check_preempt_curr(rq, p, wake_flags); |
4ae7d5ce | 2468 | |
1da177e4 | 2469 | p->state = TASK_RUNNING; |
9a897c5a | 2470 | #ifdef CONFIG_SMP |
efbbd05a PZ |
2471 | if (p->sched_class->task_woken) |
2472 | p->sched_class->task_woken(rq, p); | |
eae0c9df MG |
2473 | |
2474 | if (unlikely(rq->idle_stamp)) { | |
2475 | u64 delta = rq->clock - rq->idle_stamp; | |
2476 | u64 max = 2*sysctl_sched_migration_cost; | |
2477 | ||
2478 | if (delta > max) | |
2479 | rq->avg_idle = max; | |
2480 | else | |
2481 | update_avg(&rq->avg_idle, delta); | |
2482 | rq->idle_stamp = 0; | |
2483 | } | |
9a897c5a | 2484 | #endif |
1da177e4 LT |
2485 | out: |
2486 | task_rq_unlock(rq, &flags); | |
e9c84311 | 2487 | put_cpu(); |
1da177e4 LT |
2488 | |
2489 | return success; | |
2490 | } | |
2491 | ||
50fa610a DH |
2492 | /** |
2493 | * wake_up_process - Wake up a specific process | |
2494 | * @p: The process to be woken up. | |
2495 | * | |
2496 | * Attempt to wake up the nominated process and move it to the set of runnable | |
2497 | * processes. Returns 1 if the process was woken up, 0 if it was already | |
2498 | * running. | |
2499 | * | |
2500 | * It may be assumed that this function implies a write memory barrier before | |
2501 | * changing the task state if and only if any tasks are woken up. | |
2502 | */ | |
7ad5b3a5 | 2503 | int wake_up_process(struct task_struct *p) |
1da177e4 | 2504 | { |
d9514f6c | 2505 | return try_to_wake_up(p, TASK_ALL, 0); |
1da177e4 | 2506 | } |
1da177e4 LT |
2507 | EXPORT_SYMBOL(wake_up_process); |
2508 | ||
7ad5b3a5 | 2509 | int wake_up_state(struct task_struct *p, unsigned int state) |
1da177e4 LT |
2510 | { |
2511 | return try_to_wake_up(p, state, 0); | |
2512 | } | |
2513 | ||
1da177e4 LT |
2514 | /* |
2515 | * Perform scheduler related setup for a newly forked process p. | |
2516 | * p is forked by current. | |
dd41f596 IM |
2517 | * |
2518 | * __sched_fork() is basic setup used by init_idle() too: | |
2519 | */ | |
2520 | static void __sched_fork(struct task_struct *p) | |
2521 | { | |
dd41f596 IM |
2522 | p->se.exec_start = 0; |
2523 | p->se.sum_exec_runtime = 0; | |
f6cf891c | 2524 | p->se.prev_sum_exec_runtime = 0; |
6c594c21 | 2525 | p->se.nr_migrations = 0; |
4ae7d5ce IM |
2526 | p->se.last_wakeup = 0; |
2527 | p->se.avg_overlap = 0; | |
831451ac PZ |
2528 | p->se.start_runtime = 0; |
2529 | p->se.avg_wakeup = sysctl_sched_wakeup_granularity; | |
6cfb0d5d IM |
2530 | |
2531 | #ifdef CONFIG_SCHEDSTATS | |
7793527b LDM |
2532 | p->se.wait_start = 0; |
2533 | p->se.wait_max = 0; | |
2534 | p->se.wait_count = 0; | |
2535 | p->se.wait_sum = 0; | |
2536 | ||
2537 | p->se.sleep_start = 0; | |
2538 | p->se.sleep_max = 0; | |
2539 | p->se.sum_sleep_runtime = 0; | |
2540 | ||
2541 | p->se.block_start = 0; | |
2542 | p->se.block_max = 0; | |
2543 | p->se.exec_max = 0; | |
2544 | p->se.slice_max = 0; | |
2545 | ||
2546 | p->se.nr_migrations_cold = 0; | |
2547 | p->se.nr_failed_migrations_affine = 0; | |
2548 | p->se.nr_failed_migrations_running = 0; | |
2549 | p->se.nr_failed_migrations_hot = 0; | |
2550 | p->se.nr_forced_migrations = 0; | |
7793527b LDM |
2551 | |
2552 | p->se.nr_wakeups = 0; | |
2553 | p->se.nr_wakeups_sync = 0; | |
2554 | p->se.nr_wakeups_migrate = 0; | |
2555 | p->se.nr_wakeups_local = 0; | |
2556 | p->se.nr_wakeups_remote = 0; | |
2557 | p->se.nr_wakeups_affine = 0; | |
2558 | p->se.nr_wakeups_affine_attempts = 0; | |
2559 | p->se.nr_wakeups_passive = 0; | |
2560 | p->se.nr_wakeups_idle = 0; | |
2561 | ||
6cfb0d5d | 2562 | #endif |
476d139c | 2563 | |
fa717060 | 2564 | INIT_LIST_HEAD(&p->rt.run_list); |
dd41f596 | 2565 | p->se.on_rq = 0; |
4a55bd5e | 2566 | INIT_LIST_HEAD(&p->se.group_node); |
476d139c | 2567 | |
e107be36 AK |
2568 | #ifdef CONFIG_PREEMPT_NOTIFIERS |
2569 | INIT_HLIST_HEAD(&p->preempt_notifiers); | |
2570 | #endif | |
dd41f596 IM |
2571 | } |
2572 | ||
2573 | /* | |
2574 | * fork()/clone()-time setup: | |
2575 | */ | |
2576 | void sched_fork(struct task_struct *p, int clone_flags) | |
2577 | { | |
2578 | int cpu = get_cpu(); | |
2579 | ||
2580 | __sched_fork(p); | |
06b83b5f PZ |
2581 | /* |
2582 | * We mark the process as waking here. This guarantees that | |
2583 | * nobody will actually run it, and a signal or other external | |
2584 | * event cannot wake it up and insert it on the runqueue either. | |
2585 | */ | |
2586 | p->state = TASK_WAKING; | |
dd41f596 | 2587 | |
b9dc29e7 MG |
2588 | /* |
2589 | * Revert to default priority/policy on fork if requested. | |
2590 | */ | |
2591 | if (unlikely(p->sched_reset_on_fork)) { | |
f83f9ac2 | 2592 | if (p->policy == SCHED_FIFO || p->policy == SCHED_RR) { |
b9dc29e7 | 2593 | p->policy = SCHED_NORMAL; |
f83f9ac2 PW |
2594 | p->normal_prio = p->static_prio; |
2595 | } | |
b9dc29e7 | 2596 | |
6c697bdf MG |
2597 | if (PRIO_TO_NICE(p->static_prio) < 0) { |
2598 | p->static_prio = NICE_TO_PRIO(0); | |
f83f9ac2 | 2599 | p->normal_prio = p->static_prio; |
6c697bdf MG |
2600 | set_load_weight(p); |
2601 | } | |
2602 | ||
b9dc29e7 MG |
2603 | /* |
2604 | * We don't need the reset flag anymore after the fork. It has | |
2605 | * fulfilled its duty: | |
2606 | */ | |
2607 | p->sched_reset_on_fork = 0; | |
2608 | } | |
ca94c442 | 2609 | |
f83f9ac2 PW |
2610 | /* |
2611 | * Make sure we do not leak PI boosting priority to the child. | |
2612 | */ | |
2613 | p->prio = current->normal_prio; | |
2614 | ||
2ddbf952 HS |
2615 | if (!rt_prio(p->prio)) |
2616 | p->sched_class = &fair_sched_class; | |
b29739f9 | 2617 | |
cd29fe6f PZ |
2618 | if (p->sched_class->task_fork) |
2619 | p->sched_class->task_fork(p); | |
2620 | ||
5f3edc1b PZ |
2621 | set_task_cpu(p, cpu); |
2622 | ||
52f17b6c | 2623 | #if defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT) |
dd41f596 | 2624 | if (likely(sched_info_on())) |
52f17b6c | 2625 | memset(&p->sched_info, 0, sizeof(p->sched_info)); |
1da177e4 | 2626 | #endif |
d6077cb8 | 2627 | #if defined(CONFIG_SMP) && defined(__ARCH_WANT_UNLOCKED_CTXSW) |
4866cde0 NP |
2628 | p->oncpu = 0; |
2629 | #endif | |
1da177e4 | 2630 | #ifdef CONFIG_PREEMPT |
4866cde0 | 2631 | /* Want to start with kernel preemption disabled. */ |
a1261f54 | 2632 | task_thread_info(p)->preempt_count = 1; |
1da177e4 | 2633 | #endif |
917b627d GH |
2634 | plist_node_init(&p->pushable_tasks, MAX_PRIO); |
2635 | ||
476d139c | 2636 | put_cpu(); |
1da177e4 LT |
2637 | } |
2638 | ||
2639 | /* | |
2640 | * wake_up_new_task - wake up a newly created task for the first time. | |
2641 | * | |
2642 | * This function will do some initial scheduler statistics housekeeping | |
2643 | * that must be done for every newly created context, then puts the task | |
2644 | * on the runqueue and wakes it. | |
2645 | */ | |
7ad5b3a5 | 2646 | void wake_up_new_task(struct task_struct *p, unsigned long clone_flags) |
1da177e4 LT |
2647 | { |
2648 | unsigned long flags; | |
dd41f596 | 2649 | struct rq *rq; |
50200df4 | 2650 | int cpu __maybe_unused = get_cpu(); |
fabf318e PZ |
2651 | |
2652 | #ifdef CONFIG_SMP | |
2653 | /* | |
2654 | * Fork balancing, do it here and not earlier because: | |
2655 | * - cpus_allowed can change in the fork path | |
2656 | * - any previously selected cpu might disappear through hotplug | |
2657 | * | |
2658 | * We still have TASK_WAKING but PF_STARTING is gone now, meaning | |
2659 | * ->cpus_allowed is stable, we have preemption disabled, meaning | |
2660 | * cpu_online_mask is stable. | |
2661 | */ | |
2662 | cpu = select_task_rq(p, SD_BALANCE_FORK, 0); | |
2663 | set_task_cpu(p, cpu); | |
2664 | #endif | |
1da177e4 LT |
2665 | |
2666 | rq = task_rq_lock(p, &flags); | |
06b83b5f PZ |
2667 | BUG_ON(p->state != TASK_WAKING); |
2668 | p->state = TASK_RUNNING; | |
a8e504d2 | 2669 | update_rq_clock(rq); |
cd29fe6f | 2670 | activate_task(rq, p, 0); |
c71dd42d | 2671 | trace_sched_wakeup_new(rq, p, 1); |
a7558e01 | 2672 | check_preempt_curr(rq, p, WF_FORK); |
9a897c5a | 2673 | #ifdef CONFIG_SMP |
efbbd05a PZ |
2674 | if (p->sched_class->task_woken) |
2675 | p->sched_class->task_woken(rq, p); | |
9a897c5a | 2676 | #endif |
dd41f596 | 2677 | task_rq_unlock(rq, &flags); |
fabf318e | 2678 | put_cpu(); |
1da177e4 LT |
2679 | } |
2680 | ||
e107be36 AK |
2681 | #ifdef CONFIG_PREEMPT_NOTIFIERS |
2682 | ||
2683 | /** | |
80dd99b3 | 2684 | * preempt_notifier_register - tell me when current is being preempted & rescheduled |
421cee29 | 2685 | * @notifier: notifier struct to register |
e107be36 AK |
2686 | */ |
2687 | void preempt_notifier_register(struct preempt_notifier *notifier) | |
2688 | { | |
2689 | hlist_add_head(¬ifier->link, ¤t->preempt_notifiers); | |
2690 | } | |
2691 | EXPORT_SYMBOL_GPL(preempt_notifier_register); | |
2692 | ||
2693 | /** | |
2694 | * preempt_notifier_unregister - no longer interested in preemption notifications | |
421cee29 | 2695 | * @notifier: notifier struct to unregister |
e107be36 AK |
2696 | * |
2697 | * This is safe to call from within a preemption notifier. | |
2698 | */ | |
2699 | void preempt_notifier_unregister(struct preempt_notifier *notifier) | |
2700 | { | |
2701 | hlist_del(¬ifier->link); | |
2702 | } | |
2703 | EXPORT_SYMBOL_GPL(preempt_notifier_unregister); | |
2704 | ||
2705 | static void fire_sched_in_preempt_notifiers(struct task_struct *curr) | |
2706 | { | |
2707 | struct preempt_notifier *notifier; | |
2708 | struct hlist_node *node; | |
2709 | ||
2710 | hlist_for_each_entry(notifier, node, &curr->preempt_notifiers, link) | |
2711 | notifier->ops->sched_in(notifier, raw_smp_processor_id()); | |
2712 | } | |
2713 | ||
2714 | static void | |
2715 | fire_sched_out_preempt_notifiers(struct task_struct *curr, | |
2716 | struct task_struct *next) | |
2717 | { | |
2718 | struct preempt_notifier *notifier; | |
2719 | struct hlist_node *node; | |
2720 | ||
2721 | hlist_for_each_entry(notifier, node, &curr->preempt_notifiers, link) | |
2722 | notifier->ops->sched_out(notifier, next); | |
2723 | } | |
2724 | ||
6d6bc0ad | 2725 | #else /* !CONFIG_PREEMPT_NOTIFIERS */ |
e107be36 AK |
2726 | |
2727 | static void fire_sched_in_preempt_notifiers(struct task_struct *curr) | |
2728 | { | |
2729 | } | |
2730 | ||
2731 | static void | |
2732 | fire_sched_out_preempt_notifiers(struct task_struct *curr, | |
2733 | struct task_struct *next) | |
2734 | { | |
2735 | } | |
2736 | ||
6d6bc0ad | 2737 | #endif /* CONFIG_PREEMPT_NOTIFIERS */ |
e107be36 | 2738 | |
4866cde0 NP |
2739 | /** |
2740 | * prepare_task_switch - prepare to switch tasks | |
2741 | * @rq: the runqueue preparing to switch | |
421cee29 | 2742 | * @prev: the current task that is being switched out |
4866cde0 NP |
2743 | * @next: the task we are going to switch to. |
2744 | * | |
2745 | * This is called with the rq lock held and interrupts off. It must | |
2746 | * be paired with a subsequent finish_task_switch after the context | |
2747 | * switch. | |
2748 | * | |
2749 | * prepare_task_switch sets up locking and calls architecture specific | |
2750 | * hooks. | |
2751 | */ | |
e107be36 AK |
2752 | static inline void |
2753 | prepare_task_switch(struct rq *rq, struct task_struct *prev, | |
2754 | struct task_struct *next) | |
4866cde0 | 2755 | { |
e107be36 | 2756 | fire_sched_out_preempt_notifiers(prev, next); |
4866cde0 NP |
2757 | prepare_lock_switch(rq, next); |
2758 | prepare_arch_switch(next); | |
2759 | } | |
2760 | ||
1da177e4 LT |
2761 | /** |
2762 | * finish_task_switch - clean up after a task-switch | |
344babaa | 2763 | * @rq: runqueue associated with task-switch |
1da177e4 LT |
2764 | * @prev: the thread we just switched away from. |
2765 | * | |
4866cde0 NP |
2766 | * finish_task_switch must be called after the context switch, paired |
2767 | * with a prepare_task_switch call before the context switch. | |
2768 | * finish_task_switch will reconcile locking set up by prepare_task_switch, | |
2769 | * and do any other architecture-specific cleanup actions. | |
1da177e4 LT |
2770 | * |
2771 | * Note that we may have delayed dropping an mm in context_switch(). If | |
41a2d6cf | 2772 | * so, we finish that here outside of the runqueue lock. (Doing it |
1da177e4 LT |
2773 | * with the lock held can cause deadlocks; see schedule() for |
2774 | * details.) | |
2775 | */ | |
a9957449 | 2776 | static void finish_task_switch(struct rq *rq, struct task_struct *prev) |
1da177e4 LT |
2777 | __releases(rq->lock) |
2778 | { | |
1da177e4 | 2779 | struct mm_struct *mm = rq->prev_mm; |
55a101f8 | 2780 | long prev_state; |
1da177e4 LT |
2781 | |
2782 | rq->prev_mm = NULL; | |
2783 | ||
2784 | /* | |
2785 | * A task struct has one reference for the use as "current". | |
c394cc9f | 2786 | * If a task dies, then it sets TASK_DEAD in tsk->state and calls |
55a101f8 ON |
2787 | * schedule one last time. The schedule call will never return, and |
2788 | * the scheduled task must drop that reference. | |
c394cc9f | 2789 | * The test for TASK_DEAD must occur while the runqueue locks are |
1da177e4 LT |
2790 | * still held, otherwise prev could be scheduled on another cpu, die |
2791 | * there before we look at prev->state, and then the reference would | |
2792 | * be dropped twice. | |
2793 | * Manfred Spraul <manfred@colorfullife.com> | |
2794 | */ | |
55a101f8 | 2795 | prev_state = prev->state; |
4866cde0 | 2796 | finish_arch_switch(prev); |
cdd6c482 | 2797 | perf_event_task_sched_in(current, cpu_of(rq)); |
4866cde0 | 2798 | finish_lock_switch(rq, prev); |
e8fa1362 | 2799 | |
e107be36 | 2800 | fire_sched_in_preempt_notifiers(current); |
1da177e4 LT |
2801 | if (mm) |
2802 | mmdrop(mm); | |
c394cc9f | 2803 | if (unlikely(prev_state == TASK_DEAD)) { |
c6fd91f0 | 2804 | /* |
2805 | * Remove function-return probe instances associated with this | |
2806 | * task and put them back on the free list. | |
9761eea8 | 2807 | */ |
c6fd91f0 | 2808 | kprobe_flush_task(prev); |
1da177e4 | 2809 | put_task_struct(prev); |
c6fd91f0 | 2810 | } |
1da177e4 LT |
2811 | } |
2812 | ||
3f029d3c GH |
2813 | #ifdef CONFIG_SMP |
2814 | ||
2815 | /* assumes rq->lock is held */ | |
2816 | static inline void pre_schedule(struct rq *rq, struct task_struct *prev) | |
2817 | { | |
2818 | if (prev->sched_class->pre_schedule) | |
2819 | prev->sched_class->pre_schedule(rq, prev); | |
2820 | } | |
2821 | ||
2822 | /* rq->lock is NOT held, but preemption is disabled */ | |
2823 | static inline void post_schedule(struct rq *rq) | |
2824 | { | |
2825 | if (rq->post_schedule) { | |
2826 | unsigned long flags; | |
2827 | ||
05fa785c | 2828 | raw_spin_lock_irqsave(&rq->lock, flags); |
3f029d3c GH |
2829 | if (rq->curr->sched_class->post_schedule) |
2830 | rq->curr->sched_class->post_schedule(rq); | |
05fa785c | 2831 | raw_spin_unlock_irqrestore(&rq->lock, flags); |
3f029d3c GH |
2832 | |
2833 | rq->post_schedule = 0; | |
2834 | } | |
2835 | } | |
2836 | ||
2837 | #else | |
da19ab51 | 2838 | |
3f029d3c GH |
2839 | static inline void pre_schedule(struct rq *rq, struct task_struct *p) |
2840 | { | |
2841 | } | |
2842 | ||
2843 | static inline void post_schedule(struct rq *rq) | |
2844 | { | |
1da177e4 LT |
2845 | } |
2846 | ||
3f029d3c GH |
2847 | #endif |
2848 | ||
1da177e4 LT |
2849 | /** |
2850 | * schedule_tail - first thing a freshly forked thread must call. | |
2851 | * @prev: the thread we just switched away from. | |
2852 | */ | |
36c8b586 | 2853 | asmlinkage void schedule_tail(struct task_struct *prev) |
1da177e4 LT |
2854 | __releases(rq->lock) |
2855 | { | |
70b97a7f IM |
2856 | struct rq *rq = this_rq(); |
2857 | ||
4866cde0 | 2858 | finish_task_switch(rq, prev); |
da19ab51 | 2859 | |
3f029d3c GH |
2860 | /* |
2861 | * FIXME: do we need to worry about rq being invalidated by the | |
2862 | * task_switch? | |
2863 | */ | |
2864 | post_schedule(rq); | |
70b97a7f | 2865 | |
4866cde0 NP |
2866 | #ifdef __ARCH_WANT_UNLOCKED_CTXSW |
2867 | /* In this case, finish_task_switch does not reenable preemption */ | |
2868 | preempt_enable(); | |
2869 | #endif | |
1da177e4 | 2870 | if (current->set_child_tid) |
b488893a | 2871 | put_user(task_pid_vnr(current), current->set_child_tid); |
1da177e4 LT |
2872 | } |
2873 | ||
2874 | /* | |
2875 | * context_switch - switch to the new MM and the new | |
2876 | * thread's register state. | |
2877 | */ | |
dd41f596 | 2878 | static inline void |
70b97a7f | 2879 | context_switch(struct rq *rq, struct task_struct *prev, |
36c8b586 | 2880 | struct task_struct *next) |
1da177e4 | 2881 | { |
dd41f596 | 2882 | struct mm_struct *mm, *oldmm; |
1da177e4 | 2883 | |
e107be36 | 2884 | prepare_task_switch(rq, prev, next); |
0a16b607 | 2885 | trace_sched_switch(rq, prev, next); |
dd41f596 IM |
2886 | mm = next->mm; |
2887 | oldmm = prev->active_mm; | |
9226d125 ZA |
2888 | /* |
2889 | * For paravirt, this is coupled with an exit in switch_to to | |
2890 | * combine the page table reload and the switch backend into | |
2891 | * one hypercall. | |
2892 | */ | |
224101ed | 2893 | arch_start_context_switch(prev); |
9226d125 | 2894 | |
710390d9 | 2895 | if (likely(!mm)) { |
1da177e4 LT |
2896 | next->active_mm = oldmm; |
2897 | atomic_inc(&oldmm->mm_count); | |
2898 | enter_lazy_tlb(oldmm, next); | |
2899 | } else | |
2900 | switch_mm(oldmm, mm, next); | |
2901 | ||
710390d9 | 2902 | if (likely(!prev->mm)) { |
1da177e4 | 2903 | prev->active_mm = NULL; |
1da177e4 LT |
2904 | rq->prev_mm = oldmm; |
2905 | } | |
3a5f5e48 IM |
2906 | /* |
2907 | * Since the runqueue lock will be released by the next | |
2908 | * task (which is an invalid locking op but in the case | |
2909 | * of the scheduler it's an obvious special-case), so we | |
2910 | * do an early lockdep release here: | |
2911 | */ | |
2912 | #ifndef __ARCH_WANT_UNLOCKED_CTXSW | |
8a25d5de | 2913 | spin_release(&rq->lock.dep_map, 1, _THIS_IP_); |
3a5f5e48 | 2914 | #endif |
1da177e4 LT |
2915 | |
2916 | /* Here we just switch the register state and the stack. */ | |
2917 | switch_to(prev, next, prev); | |
2918 | ||
dd41f596 IM |
2919 | barrier(); |
2920 | /* | |
2921 | * this_rq must be evaluated again because prev may have moved | |
2922 | * CPUs since it called schedule(), thus the 'rq' on its stack | |
2923 | * frame will be invalid. | |
2924 | */ | |
2925 | finish_task_switch(this_rq(), prev); | |
1da177e4 LT |
2926 | } |
2927 | ||
2928 | /* | |
2929 | * nr_running, nr_uninterruptible and nr_context_switches: | |
2930 | * | |
2931 | * externally visible scheduler statistics: current number of runnable | |
2932 | * threads, current number of uninterruptible-sleeping threads, total | |
2933 | * number of context switches performed since bootup. | |
2934 | */ | |
2935 | unsigned long nr_running(void) | |
2936 | { | |
2937 | unsigned long i, sum = 0; | |
2938 | ||
2939 | for_each_online_cpu(i) | |
2940 | sum += cpu_rq(i)->nr_running; | |
2941 | ||
2942 | return sum; | |
2943 | } | |
2944 | ||
2945 | unsigned long nr_uninterruptible(void) | |
2946 | { | |
2947 | unsigned long i, sum = 0; | |
2948 | ||
0a945022 | 2949 | for_each_possible_cpu(i) |
1da177e4 LT |
2950 | sum += cpu_rq(i)->nr_uninterruptible; |
2951 | ||
2952 | /* | |
2953 | * Since we read the counters lockless, it might be slightly | |
2954 | * inaccurate. Do not allow it to go below zero though: | |
2955 | */ | |
2956 | if (unlikely((long)sum < 0)) | |
2957 | sum = 0; | |
2958 | ||
2959 | return sum; | |
2960 | } | |
2961 | ||
2962 | unsigned long long nr_context_switches(void) | |
2963 | { | |
cc94abfc SR |
2964 | int i; |
2965 | unsigned long long sum = 0; | |
1da177e4 | 2966 | |
0a945022 | 2967 | for_each_possible_cpu(i) |
1da177e4 LT |
2968 | sum += cpu_rq(i)->nr_switches; |
2969 | ||
2970 | return sum; | |
2971 | } | |
2972 | ||
2973 | unsigned long nr_iowait(void) | |
2974 | { | |
2975 | unsigned long i, sum = 0; | |
2976 | ||
0a945022 | 2977 | for_each_possible_cpu(i) |
1da177e4 LT |
2978 | sum += atomic_read(&cpu_rq(i)->nr_iowait); |
2979 | ||
2980 | return sum; | |
2981 | } | |
2982 | ||
69d25870 AV |
2983 | unsigned long nr_iowait_cpu(void) |
2984 | { | |
2985 | struct rq *this = this_rq(); | |
2986 | return atomic_read(&this->nr_iowait); | |
2987 | } | |
2988 | ||
2989 | unsigned long this_cpu_load(void) | |
2990 | { | |
2991 | struct rq *this = this_rq(); | |
2992 | return this->cpu_load[0]; | |
2993 | } | |
2994 | ||
2995 | ||
dce48a84 TG |
2996 | /* Variables and functions for calc_load */ |
2997 | static atomic_long_t calc_load_tasks; | |
2998 | static unsigned long calc_load_update; | |
2999 | unsigned long avenrun[3]; | |
3000 | EXPORT_SYMBOL(avenrun); | |
3001 | ||
2d02494f TG |
3002 | /** |
3003 | * get_avenrun - get the load average array | |
3004 | * @loads: pointer to dest load array | |
3005 | * @offset: offset to add | |
3006 | * @shift: shift count to shift the result left | |
3007 | * | |
3008 | * These values are estimates at best, so no need for locking. | |
3009 | */ | |
3010 | void get_avenrun(unsigned long *loads, unsigned long offset, int shift) | |
3011 | { | |
3012 | loads[0] = (avenrun[0] + offset) << shift; | |
3013 | loads[1] = (avenrun[1] + offset) << shift; | |
3014 | loads[2] = (avenrun[2] + offset) << shift; | |
3015 | } | |
3016 | ||
dce48a84 TG |
3017 | static unsigned long |
3018 | calc_load(unsigned long load, unsigned long exp, unsigned long active) | |
db1b1fef | 3019 | { |
dce48a84 TG |
3020 | load *= exp; |
3021 | load += active * (FIXED_1 - exp); | |
3022 | return load >> FSHIFT; | |
3023 | } | |
db1b1fef | 3024 | |
dce48a84 TG |
3025 | /* |
3026 | * calc_load - update the avenrun load estimates 10 ticks after the | |
3027 | * CPUs have updated calc_load_tasks. | |
3028 | */ | |
3029 | void calc_global_load(void) | |
3030 | { | |
3031 | unsigned long upd = calc_load_update + 10; | |
3032 | long active; | |
3033 | ||
3034 | if (time_before(jiffies, upd)) | |
3035 | return; | |
db1b1fef | 3036 | |
dce48a84 TG |
3037 | active = atomic_long_read(&calc_load_tasks); |
3038 | active = active > 0 ? active * FIXED_1 : 0; | |
db1b1fef | 3039 | |
dce48a84 TG |
3040 | avenrun[0] = calc_load(avenrun[0], EXP_1, active); |
3041 | avenrun[1] = calc_load(avenrun[1], EXP_5, active); | |
3042 | avenrun[2] = calc_load(avenrun[2], EXP_15, active); | |
3043 | ||
3044 | calc_load_update += LOAD_FREQ; | |
3045 | } | |
3046 | ||
3047 | /* | |
3048 | * Either called from update_cpu_load() or from a cpu going idle | |
3049 | */ | |
3050 | static void calc_load_account_active(struct rq *this_rq) | |
3051 | { | |
3052 | long nr_active, delta; | |
3053 | ||
3054 | nr_active = this_rq->nr_running; | |
3055 | nr_active += (long) this_rq->nr_uninterruptible; | |
3056 | ||
3057 | if (nr_active != this_rq->calc_load_active) { | |
3058 | delta = nr_active - this_rq->calc_load_active; | |
3059 | this_rq->calc_load_active = nr_active; | |
3060 | atomic_long_add(delta, &calc_load_tasks); | |
3061 | } | |
db1b1fef JS |
3062 | } |
3063 | ||
48f24c4d | 3064 | /* |
dd41f596 IM |
3065 | * Update rq->cpu_load[] statistics. This function is usually called every |
3066 | * scheduler tick (TICK_NSEC). | |
48f24c4d | 3067 | */ |
dd41f596 | 3068 | static void update_cpu_load(struct rq *this_rq) |
48f24c4d | 3069 | { |
495eca49 | 3070 | unsigned long this_load = this_rq->load.weight; |
dd41f596 IM |
3071 | int i, scale; |
3072 | ||
3073 | this_rq->nr_load_updates++; | |
dd41f596 IM |
3074 | |
3075 | /* Update our load: */ | |
3076 | for (i = 0, scale = 1; i < CPU_LOAD_IDX_MAX; i++, scale += scale) { | |
3077 | unsigned long old_load, new_load; | |
3078 | ||
3079 | /* scale is effectively 1 << i now, and >> i divides by scale */ | |
3080 | ||
3081 | old_load = this_rq->cpu_load[i]; | |
3082 | new_load = this_load; | |
a25707f3 IM |
3083 | /* |
3084 | * Round up the averaging division if load is increasing. This | |
3085 | * prevents us from getting stuck on 9 if the load is 10, for | |
3086 | * example. | |
3087 | */ | |
3088 | if (new_load > old_load) | |
3089 | new_load += scale-1; | |
dd41f596 IM |
3090 | this_rq->cpu_load[i] = (old_load*(scale-1) + new_load) >> i; |
3091 | } | |
dce48a84 TG |
3092 | |
3093 | if (time_after_eq(jiffies, this_rq->calc_load_update)) { | |
3094 | this_rq->calc_load_update += LOAD_FREQ; | |
3095 | calc_load_account_active(this_rq); | |
3096 | } | |
48f24c4d IM |
3097 | } |
3098 | ||
dd41f596 IM |
3099 | #ifdef CONFIG_SMP |
3100 | ||
1da177e4 LT |
3101 | /* |
3102 | * double_rq_lock - safely lock two runqueues | |
3103 | * | |
3104 | * Note this does not disable interrupts like task_rq_lock, | |
3105 | * you need to do so manually before calling. | |
3106 | */ | |
70b97a7f | 3107 | static void double_rq_lock(struct rq *rq1, struct rq *rq2) |
1da177e4 LT |
3108 | __acquires(rq1->lock) |
3109 | __acquires(rq2->lock) | |
3110 | { | |
054b9108 | 3111 | BUG_ON(!irqs_disabled()); |
1da177e4 | 3112 | if (rq1 == rq2) { |
05fa785c | 3113 | raw_spin_lock(&rq1->lock); |
1da177e4 LT |
3114 | __acquire(rq2->lock); /* Fake it out ;) */ |
3115 | } else { | |
c96d145e | 3116 | if (rq1 < rq2) { |
05fa785c TG |
3117 | raw_spin_lock(&rq1->lock); |
3118 | raw_spin_lock_nested(&rq2->lock, SINGLE_DEPTH_NESTING); | |
1da177e4 | 3119 | } else { |
05fa785c TG |
3120 | raw_spin_lock(&rq2->lock); |
3121 | raw_spin_lock_nested(&rq1->lock, SINGLE_DEPTH_NESTING); | |
1da177e4 LT |
3122 | } |
3123 | } | |
6e82a3be IM |
3124 | update_rq_clock(rq1); |
3125 | update_rq_clock(rq2); | |
1da177e4 LT |
3126 | } |
3127 | ||
3128 | /* | |
3129 | * double_rq_unlock - safely unlock two runqueues | |
3130 | * | |
3131 | * Note this does not restore interrupts like task_rq_unlock, | |
3132 | * you need to do so manually after calling. | |
3133 | */ | |
70b97a7f | 3134 | static void double_rq_unlock(struct rq *rq1, struct rq *rq2) |
1da177e4 LT |
3135 | __releases(rq1->lock) |
3136 | __releases(rq2->lock) | |
3137 | { | |
05fa785c | 3138 | raw_spin_unlock(&rq1->lock); |
1da177e4 | 3139 | if (rq1 != rq2) |
05fa785c | 3140 | raw_spin_unlock(&rq2->lock); |
1da177e4 LT |
3141 | else |
3142 | __release(rq2->lock); | |
3143 | } | |
3144 | ||
1da177e4 | 3145 | /* |
38022906 PZ |
3146 | * sched_exec - execve() is a valuable balancing opportunity, because at |
3147 | * this point the task has the smallest effective memory and cache footprint. | |
1da177e4 | 3148 | */ |
38022906 | 3149 | void sched_exec(void) |
1da177e4 | 3150 | { |
38022906 | 3151 | struct task_struct *p = current; |
70b97a7f | 3152 | struct migration_req req; |
38022906 | 3153 | int dest_cpu, this_cpu; |
1da177e4 | 3154 | unsigned long flags; |
70b97a7f | 3155 | struct rq *rq; |
1da177e4 | 3156 | |
38022906 PZ |
3157 | again: |
3158 | this_cpu = get_cpu(); | |
3159 | dest_cpu = select_task_rq(p, SD_BALANCE_EXEC, 0); | |
3160 | if (dest_cpu == this_cpu) { | |
3161 | put_cpu(); | |
3162 | return; | |
3163 | } | |
3164 | ||
1da177e4 | 3165 | rq = task_rq_lock(p, &flags); |
38022906 PZ |
3166 | put_cpu(); |
3167 | ||
3168 | /* | |
3169 | * select_task_rq() can race against ->cpus_allowed | |
3170 | */ | |
96f874e2 | 3171 | if (!cpumask_test_cpu(dest_cpu, &p->cpus_allowed) |
38022906 PZ |
3172 | || unlikely(!cpu_active(dest_cpu))) { |
3173 | task_rq_unlock(rq, &flags); | |
3174 | goto again; | |
3175 | } | |
1da177e4 LT |
3176 | |
3177 | /* force the process onto the specified CPU */ | |
3178 | if (migrate_task(p, dest_cpu, &req)) { | |
3179 | /* Need to wait for migration thread (might exit: take ref). */ | |
3180 | struct task_struct *mt = rq->migration_thread; | |
36c8b586 | 3181 | |
1da177e4 LT |
3182 | get_task_struct(mt); |
3183 | task_rq_unlock(rq, &flags); | |
3184 | wake_up_process(mt); | |
3185 | put_task_struct(mt); | |
3186 | wait_for_completion(&req.done); | |
36c8b586 | 3187 | |
1da177e4 LT |
3188 | return; |
3189 | } | |
1da177e4 LT |
3190 | task_rq_unlock(rq, &flags); |
3191 | } | |
3192 | ||
1da177e4 LT |
3193 | /* |
3194 | * pull_task - move a task from a remote runqueue to the local runqueue. | |
3195 | * Both runqueues must be locked. | |
3196 | */ | |
dd41f596 IM |
3197 | static void pull_task(struct rq *src_rq, struct task_struct *p, |
3198 | struct rq *this_rq, int this_cpu) | |
1da177e4 | 3199 | { |
2e1cb74a | 3200 | deactivate_task(src_rq, p, 0); |
1da177e4 | 3201 | set_task_cpu(p, this_cpu); |
dd41f596 | 3202 | activate_task(this_rq, p, 0); |
15afe09b | 3203 | check_preempt_curr(this_rq, p, 0); |
1da177e4 LT |
3204 | } |
3205 | ||
3206 | /* | |
3207 | * can_migrate_task - may task p from runqueue rq be migrated to this_cpu? | |
3208 | */ | |
858119e1 | 3209 | static |
70b97a7f | 3210 | int can_migrate_task(struct task_struct *p, struct rq *rq, int this_cpu, |
d15bcfdb | 3211 | struct sched_domain *sd, enum cpu_idle_type idle, |
95cdf3b7 | 3212 | int *all_pinned) |
1da177e4 | 3213 | { |
708dc512 | 3214 | int tsk_cache_hot = 0; |
1da177e4 LT |
3215 | /* |
3216 | * We do not migrate tasks that are: | |
3217 | * 1) running (obviously), or | |
3218 | * 2) cannot be migrated to this CPU due to cpus_allowed, or | |
3219 | * 3) are cache-hot on their current CPU. | |
3220 | */ | |
96f874e2 | 3221 | if (!cpumask_test_cpu(this_cpu, &p->cpus_allowed)) { |
cc367732 | 3222 | schedstat_inc(p, se.nr_failed_migrations_affine); |
1da177e4 | 3223 | return 0; |
cc367732 | 3224 | } |
81026794 NP |
3225 | *all_pinned = 0; |
3226 | ||
cc367732 IM |
3227 | if (task_running(rq, p)) { |
3228 | schedstat_inc(p, se.nr_failed_migrations_running); | |
81026794 | 3229 | return 0; |
cc367732 | 3230 | } |
1da177e4 | 3231 | |
da84d961 IM |
3232 | /* |
3233 | * Aggressive migration if: | |
3234 | * 1) task is cache cold, or | |
3235 | * 2) too many balance attempts have failed. | |
3236 | */ | |
3237 | ||
708dc512 LH |
3238 | tsk_cache_hot = task_hot(p, rq->clock, sd); |
3239 | if (!tsk_cache_hot || | |
3240 | sd->nr_balance_failed > sd->cache_nice_tries) { | |
da84d961 | 3241 | #ifdef CONFIG_SCHEDSTATS |
708dc512 | 3242 | if (tsk_cache_hot) { |
da84d961 | 3243 | schedstat_inc(sd, lb_hot_gained[idle]); |
cc367732 IM |
3244 | schedstat_inc(p, se.nr_forced_migrations); |
3245 | } | |
da84d961 IM |
3246 | #endif |
3247 | return 1; | |
3248 | } | |
3249 | ||
708dc512 | 3250 | if (tsk_cache_hot) { |
cc367732 | 3251 | schedstat_inc(p, se.nr_failed_migrations_hot); |
da84d961 | 3252 | return 0; |
cc367732 | 3253 | } |
1da177e4 LT |
3254 | return 1; |
3255 | } | |
3256 | ||
e1d1484f PW |
3257 | static unsigned long |
3258 | balance_tasks(struct rq *this_rq, int this_cpu, struct rq *busiest, | |
3259 | unsigned long max_load_move, struct sched_domain *sd, | |
3260 | enum cpu_idle_type idle, int *all_pinned, | |
3261 | int *this_best_prio, struct rq_iterator *iterator) | |
1da177e4 | 3262 | { |
051c6764 | 3263 | int loops = 0, pulled = 0, pinned = 0; |
dd41f596 IM |
3264 | struct task_struct *p; |
3265 | long rem_load_move = max_load_move; | |
1da177e4 | 3266 | |
e1d1484f | 3267 | if (max_load_move == 0) |
1da177e4 LT |
3268 | goto out; |
3269 | ||
81026794 NP |
3270 | pinned = 1; |
3271 | ||
1da177e4 | 3272 | /* |
dd41f596 | 3273 | * Start the load-balancing iterator: |
1da177e4 | 3274 | */ |
dd41f596 IM |
3275 | p = iterator->start(iterator->arg); |
3276 | next: | |
b82d9fdd | 3277 | if (!p || loops++ > sysctl_sched_nr_migrate) |
1da177e4 | 3278 | goto out; |
051c6764 PZ |
3279 | |
3280 | if ((p->se.load.weight >> 1) > rem_load_move || | |
dd41f596 | 3281 | !can_migrate_task(p, busiest, this_cpu, sd, idle, &pinned)) { |
dd41f596 IM |
3282 | p = iterator->next(iterator->arg); |
3283 | goto next; | |
1da177e4 LT |
3284 | } |
3285 | ||
dd41f596 | 3286 | pull_task(busiest, p, this_rq, this_cpu); |
1da177e4 | 3287 | pulled++; |
dd41f596 | 3288 | rem_load_move -= p->se.load.weight; |
1da177e4 | 3289 | |
7e96fa58 GH |
3290 | #ifdef CONFIG_PREEMPT |
3291 | /* | |
3292 | * NEWIDLE balancing is a source of latency, so preemptible kernels | |
3293 | * will stop after the first task is pulled to minimize the critical | |
3294 | * section. | |
3295 | */ | |
3296 | if (idle == CPU_NEWLY_IDLE) | |
3297 | goto out; | |
3298 | #endif | |
3299 | ||
2dd73a4f | 3300 | /* |
b82d9fdd | 3301 | * We only want to steal up to the prescribed amount of weighted load. |
2dd73a4f | 3302 | */ |
e1d1484f | 3303 | if (rem_load_move > 0) { |
a4ac01c3 PW |
3304 | if (p->prio < *this_best_prio) |
3305 | *this_best_prio = p->prio; | |
dd41f596 IM |
3306 | p = iterator->next(iterator->arg); |
3307 | goto next; | |
1da177e4 LT |
3308 | } |
3309 | out: | |
3310 | /* | |
e1d1484f | 3311 | * Right now, this is one of only two places pull_task() is called, |
1da177e4 LT |
3312 | * so we can safely collect pull_task() stats here rather than |
3313 | * inside pull_task(). | |
3314 | */ | |
3315 | schedstat_add(sd, lb_gained[idle], pulled); | |
81026794 NP |
3316 | |
3317 | if (all_pinned) | |
3318 | *all_pinned = pinned; | |
e1d1484f PW |
3319 | |
3320 | return max_load_move - rem_load_move; | |
1da177e4 LT |
3321 | } |
3322 | ||
dd41f596 | 3323 | /* |
43010659 PW |
3324 | * move_tasks tries to move up to max_load_move weighted load from busiest to |
3325 | * this_rq, as part of a balancing operation within domain "sd". | |
3326 | * Returns 1 if successful and 0 otherwise. | |
dd41f596 IM |
3327 | * |
3328 | * Called with both runqueues locked. | |
3329 | */ | |
3330 | static int move_tasks(struct rq *this_rq, int this_cpu, struct rq *busiest, | |
43010659 | 3331 | unsigned long max_load_move, |
dd41f596 IM |
3332 | struct sched_domain *sd, enum cpu_idle_type idle, |
3333 | int *all_pinned) | |
3334 | { | |
5522d5d5 | 3335 | const struct sched_class *class = sched_class_highest; |
43010659 | 3336 | unsigned long total_load_moved = 0; |
a4ac01c3 | 3337 | int this_best_prio = this_rq->curr->prio; |
dd41f596 IM |
3338 | |
3339 | do { | |
43010659 PW |
3340 | total_load_moved += |
3341 | class->load_balance(this_rq, this_cpu, busiest, | |
e1d1484f | 3342 | max_load_move - total_load_moved, |
a4ac01c3 | 3343 | sd, idle, all_pinned, &this_best_prio); |
dd41f596 | 3344 | class = class->next; |
c4acb2c0 | 3345 | |
7e96fa58 GH |
3346 | #ifdef CONFIG_PREEMPT |
3347 | /* | |
3348 | * NEWIDLE balancing is a source of latency, so preemptible | |
3349 | * kernels will stop after the first task is pulled to minimize | |
3350 | * the critical section. | |
3351 | */ | |
c4acb2c0 GH |
3352 | if (idle == CPU_NEWLY_IDLE && this_rq->nr_running) |
3353 | break; | |
7e96fa58 | 3354 | #endif |
43010659 | 3355 | } while (class && max_load_move > total_load_moved); |
dd41f596 | 3356 | |
43010659 PW |
3357 | return total_load_moved > 0; |
3358 | } | |
3359 | ||
e1d1484f PW |
3360 | static int |
3361 | iter_move_one_task(struct rq *this_rq, int this_cpu, struct rq *busiest, | |
3362 | struct sched_domain *sd, enum cpu_idle_type idle, | |
3363 | struct rq_iterator *iterator) | |
3364 | { | |
3365 | struct task_struct *p = iterator->start(iterator->arg); | |
3366 | int pinned = 0; | |
3367 | ||
3368 | while (p) { | |
3369 | if (can_migrate_task(p, busiest, this_cpu, sd, idle, &pinned)) { | |
3370 | pull_task(busiest, p, this_rq, this_cpu); | |
3371 | /* | |
3372 | * Right now, this is only the second place pull_task() | |
3373 | * is called, so we can safely collect pull_task() | |
3374 | * stats here rather than inside pull_task(). | |
3375 | */ | |
3376 | schedstat_inc(sd, lb_gained[idle]); | |
3377 | ||
3378 | return 1; | |
3379 | } | |
3380 | p = iterator->next(iterator->arg); | |
3381 | } | |
3382 | ||
3383 | return 0; | |
3384 | } | |
3385 | ||
43010659 PW |
3386 | /* |
3387 | * move_one_task tries to move exactly one task from busiest to this_rq, as | |
3388 | * part of active balancing operations within "domain". | |
3389 | * Returns 1 if successful and 0 otherwise. | |
3390 | * | |
3391 | * Called with both runqueues locked. | |
3392 | */ | |
3393 | static int move_one_task(struct rq *this_rq, int this_cpu, struct rq *busiest, | |
3394 | struct sched_domain *sd, enum cpu_idle_type idle) | |
3395 | { | |
5522d5d5 | 3396 | const struct sched_class *class; |
43010659 | 3397 | |
cde7e5ca | 3398 | for_each_class(class) { |
e1d1484f | 3399 | if (class->move_one_task(this_rq, this_cpu, busiest, sd, idle)) |
43010659 | 3400 | return 1; |
cde7e5ca | 3401 | } |
43010659 PW |
3402 | |
3403 | return 0; | |
dd41f596 | 3404 | } |
67bb6c03 | 3405 | /********** Helpers for find_busiest_group ************************/ |
1da177e4 | 3406 | /* |
222d656d GS |
3407 | * sd_lb_stats - Structure to store the statistics of a sched_domain |
3408 | * during load balancing. | |
1da177e4 | 3409 | */ |
222d656d GS |
3410 | struct sd_lb_stats { |
3411 | struct sched_group *busiest; /* Busiest group in this sd */ | |
3412 | struct sched_group *this; /* Local group in this sd */ | |
3413 | unsigned long total_load; /* Total load of all groups in sd */ | |
3414 | unsigned long total_pwr; /* Total power of all groups in sd */ | |
3415 | unsigned long avg_load; /* Average load across all groups in sd */ | |
3416 | ||
3417 | /** Statistics of this group */ | |
3418 | unsigned long this_load; | |
3419 | unsigned long this_load_per_task; | |
3420 | unsigned long this_nr_running; | |
3421 | ||
3422 | /* Statistics of the busiest group */ | |
3423 | unsigned long max_load; | |
3424 | unsigned long busiest_load_per_task; | |
3425 | unsigned long busiest_nr_running; | |
3426 | ||
3427 | int group_imb; /* Is there imbalance in this sd */ | |
5c45bf27 | 3428 | #if defined(CONFIG_SCHED_MC) || defined(CONFIG_SCHED_SMT) |
222d656d GS |
3429 | int power_savings_balance; /* Is powersave balance needed for this sd */ |
3430 | struct sched_group *group_min; /* Least loaded group in sd */ | |
3431 | struct sched_group *group_leader; /* Group which relieves group_min */ | |
3432 | unsigned long min_load_per_task; /* load_per_task in group_min */ | |
3433 | unsigned long leader_nr_running; /* Nr running of group_leader */ | |
3434 | unsigned long min_nr_running; /* Nr running of group_min */ | |
5c45bf27 | 3435 | #endif |
222d656d | 3436 | }; |
1da177e4 | 3437 | |
d5ac537e | 3438 | /* |
381be78f GS |
3439 | * sg_lb_stats - stats of a sched_group required for load_balancing |
3440 | */ | |
3441 | struct sg_lb_stats { | |
3442 | unsigned long avg_load; /*Avg load across the CPUs of the group */ | |
3443 | unsigned long group_load; /* Total load over the CPUs of the group */ | |
3444 | unsigned long sum_nr_running; /* Nr tasks running in the group */ | |
3445 | unsigned long sum_weighted_load; /* Weighted load of group's tasks */ | |
3446 | unsigned long group_capacity; | |
3447 | int group_imb; /* Is there an imbalance in the group ? */ | |
3448 | }; | |
408ed066 | 3449 | |
67bb6c03 GS |
3450 | /** |
3451 | * group_first_cpu - Returns the first cpu in the cpumask of a sched_group. | |
3452 | * @group: The group whose first cpu is to be returned. | |
3453 | */ | |
3454 | static inline unsigned int group_first_cpu(struct sched_group *group) | |
3455 | { | |
3456 | return cpumask_first(sched_group_cpus(group)); | |
3457 | } | |
3458 | ||
3459 | /** | |
3460 | * get_sd_load_idx - Obtain the load index for a given sched domain. | |
3461 | * @sd: The sched_domain whose load_idx is to be obtained. | |
3462 | * @idle: The Idle status of the CPU for whose sd load_icx is obtained. | |
3463 | */ | |
3464 | static inline int get_sd_load_idx(struct sched_domain *sd, | |
3465 | enum cpu_idle_type idle) | |
3466 | { | |
3467 | int load_idx; | |
3468 | ||
3469 | switch (idle) { | |
3470 | case CPU_NOT_IDLE: | |
7897986b | 3471 | load_idx = sd->busy_idx; |
67bb6c03 GS |
3472 | break; |
3473 | ||
3474 | case CPU_NEWLY_IDLE: | |
7897986b | 3475 | load_idx = sd->newidle_idx; |
67bb6c03 GS |
3476 | break; |
3477 | default: | |
7897986b | 3478 | load_idx = sd->idle_idx; |
67bb6c03 GS |
3479 | break; |
3480 | } | |
1da177e4 | 3481 | |
67bb6c03 GS |
3482 | return load_idx; |
3483 | } | |
1da177e4 | 3484 | |
1da177e4 | 3485 | |
c071df18 GS |
3486 | #if defined(CONFIG_SCHED_MC) || defined(CONFIG_SCHED_SMT) |
3487 | /** | |
3488 | * init_sd_power_savings_stats - Initialize power savings statistics for | |
3489 | * the given sched_domain, during load balancing. | |
3490 | * | |
3491 | * @sd: Sched domain whose power-savings statistics are to be initialized. | |
3492 | * @sds: Variable containing the statistics for sd. | |
3493 | * @idle: Idle status of the CPU at which we're performing load-balancing. | |
3494 | */ | |
3495 | static inline void init_sd_power_savings_stats(struct sched_domain *sd, | |
3496 | struct sd_lb_stats *sds, enum cpu_idle_type idle) | |
3497 | { | |
3498 | /* | |
3499 | * Busy processors will not participate in power savings | |
3500 | * balance. | |
3501 | */ | |
3502 | if (idle == CPU_NOT_IDLE || !(sd->flags & SD_POWERSAVINGS_BALANCE)) | |
3503 | sds->power_savings_balance = 0; | |
3504 | else { | |
3505 | sds->power_savings_balance = 1; | |
3506 | sds->min_nr_running = ULONG_MAX; | |
3507 | sds->leader_nr_running = 0; | |
3508 | } | |
3509 | } | |
783609c6 | 3510 | |
c071df18 GS |
3511 | /** |
3512 | * update_sd_power_savings_stats - Update the power saving stats for a | |
3513 | * sched_domain while performing load balancing. | |
3514 | * | |
3515 | * @group: sched_group belonging to the sched_domain under consideration. | |
3516 | * @sds: Variable containing the statistics of the sched_domain | |
3517 | * @local_group: Does group contain the CPU for which we're performing | |
3518 | * load balancing ? | |
3519 | * @sgs: Variable containing the statistics of the group. | |
3520 | */ | |
3521 | static inline void update_sd_power_savings_stats(struct sched_group *group, | |
3522 | struct sd_lb_stats *sds, int local_group, struct sg_lb_stats *sgs) | |
3523 | { | |
408ed066 | 3524 | |
c071df18 GS |
3525 | if (!sds->power_savings_balance) |
3526 | return; | |
1da177e4 | 3527 | |
c071df18 GS |
3528 | /* |
3529 | * If the local group is idle or completely loaded | |
3530 | * no need to do power savings balance at this domain | |
3531 | */ | |
3532 | if (local_group && (sds->this_nr_running >= sgs->group_capacity || | |
3533 | !sds->this_nr_running)) | |
3534 | sds->power_savings_balance = 0; | |
2dd73a4f | 3535 | |
c071df18 GS |
3536 | /* |
3537 | * If a group is already running at full capacity or idle, | |
3538 | * don't include that group in power savings calculations | |
3539 | */ | |
3540 | if (!sds->power_savings_balance || | |
3541 | sgs->sum_nr_running >= sgs->group_capacity || | |
3542 | !sgs->sum_nr_running) | |
3543 | return; | |
5969fe06 | 3544 | |
c071df18 GS |
3545 | /* |
3546 | * Calculate the group which has the least non-idle load. | |
3547 | * This is the group from where we need to pick up the load | |
3548 | * for saving power | |
3549 | */ | |
3550 | if ((sgs->sum_nr_running < sds->min_nr_running) || | |
3551 | (sgs->sum_nr_running == sds->min_nr_running && | |
3552 | group_first_cpu(group) > group_first_cpu(sds->group_min))) { | |
3553 | sds->group_min = group; | |
3554 | sds->min_nr_running = sgs->sum_nr_running; | |
3555 | sds->min_load_per_task = sgs->sum_weighted_load / | |
3556 | sgs->sum_nr_running; | |
3557 | } | |
783609c6 | 3558 | |
c071df18 GS |
3559 | /* |
3560 | * Calculate the group which is almost near its | |
3561 | * capacity but still has some space to pick up some load | |
3562 | * from other group and save more power | |
3563 | */ | |
d899a789 | 3564 | if (sgs->sum_nr_running + 1 > sgs->group_capacity) |
c071df18 | 3565 | return; |
1da177e4 | 3566 | |
c071df18 GS |
3567 | if (sgs->sum_nr_running > sds->leader_nr_running || |
3568 | (sgs->sum_nr_running == sds->leader_nr_running && | |
3569 | group_first_cpu(group) < group_first_cpu(sds->group_leader))) { | |
3570 | sds->group_leader = group; | |
3571 | sds->leader_nr_running = sgs->sum_nr_running; | |
3572 | } | |
3573 | } | |
408ed066 | 3574 | |
c071df18 | 3575 | /** |
d5ac537e | 3576 | * check_power_save_busiest_group - see if there is potential for some power-savings balance |
c071df18 GS |
3577 | * @sds: Variable containing the statistics of the sched_domain |
3578 | * under consideration. | |
3579 | * @this_cpu: Cpu at which we're currently performing load-balancing. | |
3580 | * @imbalance: Variable to store the imbalance. | |
3581 | * | |
d5ac537e RD |
3582 | * Description: |
3583 | * Check if we have potential to perform some power-savings balance. | |
3584 | * If yes, set the busiest group to be the least loaded group in the | |
3585 | * sched_domain, so that it's CPUs can be put to idle. | |
3586 | * | |
c071df18 GS |
3587 | * Returns 1 if there is potential to perform power-savings balance. |
3588 | * Else returns 0. | |
3589 | */ | |
3590 | static inline int check_power_save_busiest_group(struct sd_lb_stats *sds, | |
3591 | int this_cpu, unsigned long *imbalance) | |
3592 | { | |
3593 | if (!sds->power_savings_balance) | |
3594 | return 0; | |
1da177e4 | 3595 | |
c071df18 GS |
3596 | if (sds->this != sds->group_leader || |
3597 | sds->group_leader == sds->group_min) | |
3598 | return 0; | |
783609c6 | 3599 | |
c071df18 GS |
3600 | *imbalance = sds->min_load_per_task; |
3601 | sds->busiest = sds->group_min; | |
1da177e4 | 3602 | |
c071df18 | 3603 | return 1; |
1da177e4 | 3604 | |
c071df18 GS |
3605 | } |
3606 | #else /* CONFIG_SCHED_MC || CONFIG_SCHED_SMT */ | |
3607 | static inline void init_sd_power_savings_stats(struct sched_domain *sd, | |
3608 | struct sd_lb_stats *sds, enum cpu_idle_type idle) | |
3609 | { | |
3610 | return; | |
3611 | } | |
408ed066 | 3612 | |
c071df18 GS |
3613 | static inline void update_sd_power_savings_stats(struct sched_group *group, |
3614 | struct sd_lb_stats *sds, int local_group, struct sg_lb_stats *sgs) | |
3615 | { | |
3616 | return; | |
3617 | } | |
3618 | ||
3619 | static inline int check_power_save_busiest_group(struct sd_lb_stats *sds, | |
3620 | int this_cpu, unsigned long *imbalance) | |
3621 | { | |
3622 | return 0; | |
3623 | } | |
3624 | #endif /* CONFIG_SCHED_MC || CONFIG_SCHED_SMT */ | |
3625 | ||
d6a59aa3 PZ |
3626 | |
3627 | unsigned long default_scale_freq_power(struct sched_domain *sd, int cpu) | |
3628 | { | |
3629 | return SCHED_LOAD_SCALE; | |
3630 | } | |
3631 | ||
3632 | unsigned long __weak arch_scale_freq_power(struct sched_domain *sd, int cpu) | |
3633 | { | |
3634 | return default_scale_freq_power(sd, cpu); | |
3635 | } | |
3636 | ||
3637 | unsigned long default_scale_smt_power(struct sched_domain *sd, int cpu) | |
ab29230e PZ |
3638 | { |
3639 | unsigned long weight = cpumask_weight(sched_domain_span(sd)); | |
3640 | unsigned long smt_gain = sd->smt_gain; | |
3641 | ||
3642 | smt_gain /= weight; | |
3643 | ||
3644 | return smt_gain; | |
3645 | } | |
3646 | ||
d6a59aa3 PZ |
3647 | unsigned long __weak arch_scale_smt_power(struct sched_domain *sd, int cpu) |
3648 | { | |
3649 | return default_scale_smt_power(sd, cpu); | |
3650 | } | |
3651 | ||
e9e9250b PZ |
3652 | unsigned long scale_rt_power(int cpu) |
3653 | { | |
3654 | struct rq *rq = cpu_rq(cpu); | |
3655 | u64 total, available; | |
3656 | ||
3657 | sched_avg_update(rq); | |
3658 | ||
3659 | total = sched_avg_period() + (rq->clock - rq->age_stamp); | |
3660 | available = total - rq->rt_avg; | |
3661 | ||
3662 | if (unlikely((s64)total < SCHED_LOAD_SCALE)) | |
3663 | total = SCHED_LOAD_SCALE; | |
3664 | ||
3665 | total >>= SCHED_LOAD_SHIFT; | |
3666 | ||
3667 | return div_u64(available, total); | |
3668 | } | |
3669 | ||
ab29230e PZ |
3670 | static void update_cpu_power(struct sched_domain *sd, int cpu) |
3671 | { | |
3672 | unsigned long weight = cpumask_weight(sched_domain_span(sd)); | |
3673 | unsigned long power = SCHED_LOAD_SCALE; | |
3674 | struct sched_group *sdg = sd->groups; | |
ab29230e | 3675 | |
8e6598af PZ |
3676 | if (sched_feat(ARCH_POWER)) |
3677 | power *= arch_scale_freq_power(sd, cpu); | |
3678 | else | |
3679 | power *= default_scale_freq_power(sd, cpu); | |
3680 | ||
d6a59aa3 | 3681 | power >>= SCHED_LOAD_SHIFT; |
ab29230e PZ |
3682 | |
3683 | if ((sd->flags & SD_SHARE_CPUPOWER) && weight > 1) { | |
8e6598af PZ |
3684 | if (sched_feat(ARCH_POWER)) |
3685 | power *= arch_scale_smt_power(sd, cpu); | |
3686 | else | |
3687 | power *= default_scale_smt_power(sd, cpu); | |
3688 | ||
ab29230e PZ |
3689 | power >>= SCHED_LOAD_SHIFT; |
3690 | } | |
3691 | ||
e9e9250b PZ |
3692 | power *= scale_rt_power(cpu); |
3693 | power >>= SCHED_LOAD_SHIFT; | |
3694 | ||
3695 | if (!power) | |
3696 | power = 1; | |
ab29230e | 3697 | |
18a3885f | 3698 | sdg->cpu_power = power; |
ab29230e PZ |
3699 | } |
3700 | ||
3701 | static void update_group_power(struct sched_domain *sd, int cpu) | |
cc9fba7d PZ |
3702 | { |
3703 | struct sched_domain *child = sd->child; | |
3704 | struct sched_group *group, *sdg = sd->groups; | |
d7ea17a7 | 3705 | unsigned long power; |
cc9fba7d PZ |
3706 | |
3707 | if (!child) { | |
ab29230e | 3708 | update_cpu_power(sd, cpu); |
cc9fba7d PZ |
3709 | return; |
3710 | } | |
3711 | ||
d7ea17a7 | 3712 | power = 0; |
cc9fba7d PZ |
3713 | |
3714 | group = child->groups; | |
3715 | do { | |
d7ea17a7 | 3716 | power += group->cpu_power; |
cc9fba7d PZ |
3717 | group = group->next; |
3718 | } while (group != child->groups); | |
d7ea17a7 IM |
3719 | |
3720 | sdg->cpu_power = power; | |
cc9fba7d | 3721 | } |
c071df18 | 3722 | |
1f8c553d GS |
3723 | /** |
3724 | * update_sg_lb_stats - Update sched_group's statistics for load balancing. | |
e17b38bf | 3725 | * @sd: The sched_domain whose statistics are to be updated. |
1f8c553d GS |
3726 | * @group: sched_group whose statistics are to be updated. |
3727 | * @this_cpu: Cpu for which load balance is currently performed. | |
3728 | * @idle: Idle status of this_cpu | |
3729 | * @load_idx: Load index of sched_domain of this_cpu for load calc. | |
3730 | * @sd_idle: Idle status of the sched_domain containing group. | |
3731 | * @local_group: Does group contain this_cpu. | |
3732 | * @cpus: Set of cpus considered for load balancing. | |
3733 | * @balance: Should we balance. | |
3734 | * @sgs: variable to hold the statistics for this group. | |
3735 | */ | |
cc9fba7d PZ |
3736 | static inline void update_sg_lb_stats(struct sched_domain *sd, |
3737 | struct sched_group *group, int this_cpu, | |
1f8c553d GS |
3738 | enum cpu_idle_type idle, int load_idx, int *sd_idle, |
3739 | int local_group, const struct cpumask *cpus, | |
3740 | int *balance, struct sg_lb_stats *sgs) | |
3741 | { | |
3742 | unsigned long load, max_cpu_load, min_cpu_load; | |
3743 | int i; | |
3744 | unsigned int balance_cpu = -1, first_idle_cpu = 0; | |
3745 | unsigned long sum_avg_load_per_task; | |
3746 | unsigned long avg_load_per_task; | |
3747 | ||
cc9fba7d | 3748 | if (local_group) { |
1f8c553d | 3749 | balance_cpu = group_first_cpu(group); |
cc9fba7d | 3750 | if (balance_cpu == this_cpu) |
ab29230e | 3751 | update_group_power(sd, this_cpu); |
cc9fba7d | 3752 | } |
1f8c553d GS |
3753 | |
3754 | /* Tally up the load of all CPUs in the group */ | |
3755 | sum_avg_load_per_task = avg_load_per_task = 0; | |
3756 | max_cpu_load = 0; | |
3757 | min_cpu_load = ~0UL; | |
408ed066 | 3758 | |
1f8c553d GS |
3759 | for_each_cpu_and(i, sched_group_cpus(group), cpus) { |
3760 | struct rq *rq = cpu_rq(i); | |
908a7c1b | 3761 | |
1f8c553d GS |
3762 | if (*sd_idle && rq->nr_running) |
3763 | *sd_idle = 0; | |
5c45bf27 | 3764 | |
1f8c553d | 3765 | /* Bias balancing toward cpus of our domain */ |
1da177e4 | 3766 | if (local_group) { |
1f8c553d GS |
3767 | if (idle_cpu(i) && !first_idle_cpu) { |
3768 | first_idle_cpu = 1; | |
3769 | balance_cpu = i; | |
3770 | } | |
3771 | ||
3772 | load = target_load(i, load_idx); | |
3773 | } else { | |
3774 | load = source_load(i, load_idx); | |
3775 | if (load > max_cpu_load) | |
3776 | max_cpu_load = load; | |
3777 | if (min_cpu_load > load) | |
3778 | min_cpu_load = load; | |
1da177e4 | 3779 | } |
5c45bf27 | 3780 | |
1f8c553d GS |
3781 | sgs->group_load += load; |
3782 | sgs->sum_nr_running += rq->nr_running; | |
3783 | sgs->sum_weighted_load += weighted_cpuload(i); | |
5c45bf27 | 3784 | |
1f8c553d GS |
3785 | sum_avg_load_per_task += cpu_avg_load_per_task(i); |
3786 | } | |
5c45bf27 | 3787 | |
1f8c553d GS |
3788 | /* |
3789 | * First idle cpu or the first cpu(busiest) in this sched group | |
3790 | * is eligible for doing load balancing at this and above | |
3791 | * domains. In the newly idle case, we will allow all the cpu's | |
3792 | * to do the newly idle load balance. | |
3793 | */ | |
3794 | if (idle != CPU_NEWLY_IDLE && local_group && | |
3795 | balance_cpu != this_cpu && balance) { | |
3796 | *balance = 0; | |
3797 | return; | |
3798 | } | |
5c45bf27 | 3799 | |
1f8c553d | 3800 | /* Adjust by relative CPU power of the group */ |
18a3885f | 3801 | sgs->avg_load = (sgs->group_load * SCHED_LOAD_SCALE) / group->cpu_power; |
5c45bf27 | 3802 | |
1f8c553d GS |
3803 | |
3804 | /* | |
3805 | * Consider the group unbalanced when the imbalance is larger | |
3806 | * than the average weight of two tasks. | |
3807 | * | |
3808 | * APZ: with cgroup the avg task weight can vary wildly and | |
3809 | * might not be a suitable number - should we keep a | |
3810 | * normalized nr_running number somewhere that negates | |
3811 | * the hierarchy? | |
3812 | */ | |
18a3885f PZ |
3813 | avg_load_per_task = (sum_avg_load_per_task * SCHED_LOAD_SCALE) / |
3814 | group->cpu_power; | |
1f8c553d GS |
3815 | |
3816 | if ((max_cpu_load - min_cpu_load) > 2*avg_load_per_task) | |
3817 | sgs->group_imb = 1; | |
3818 | ||
bdb94aa5 | 3819 | sgs->group_capacity = |
18a3885f | 3820 | DIV_ROUND_CLOSEST(group->cpu_power, SCHED_LOAD_SCALE); |
1f8c553d | 3821 | } |
dd41f596 | 3822 | |
37abe198 GS |
3823 | /** |
3824 | * update_sd_lb_stats - Update sched_group's statistics for load balancing. | |
3825 | * @sd: sched_domain whose statistics are to be updated. | |
3826 | * @this_cpu: Cpu for which load balance is currently performed. | |
3827 | * @idle: Idle status of this_cpu | |
3828 | * @sd_idle: Idle status of the sched_domain containing group. | |
3829 | * @cpus: Set of cpus considered for load balancing. | |
3830 | * @balance: Should we balance. | |
3831 | * @sds: variable to hold the statistics for this sched_domain. | |
1da177e4 | 3832 | */ |
37abe198 GS |
3833 | static inline void update_sd_lb_stats(struct sched_domain *sd, int this_cpu, |
3834 | enum cpu_idle_type idle, int *sd_idle, | |
3835 | const struct cpumask *cpus, int *balance, | |
3836 | struct sd_lb_stats *sds) | |
1da177e4 | 3837 | { |
b5d978e0 | 3838 | struct sched_domain *child = sd->child; |
222d656d | 3839 | struct sched_group *group = sd->groups; |
37abe198 | 3840 | struct sg_lb_stats sgs; |
b5d978e0 PZ |
3841 | int load_idx, prefer_sibling = 0; |
3842 | ||
3843 | if (child && child->flags & SD_PREFER_SIBLING) | |
3844 | prefer_sibling = 1; | |
222d656d | 3845 | |
c071df18 | 3846 | init_sd_power_savings_stats(sd, sds, idle); |
67bb6c03 | 3847 | load_idx = get_sd_load_idx(sd, idle); |
1da177e4 LT |
3848 | |
3849 | do { | |
1da177e4 | 3850 | int local_group; |
1da177e4 | 3851 | |
758b2cdc RR |
3852 | local_group = cpumask_test_cpu(this_cpu, |
3853 | sched_group_cpus(group)); | |
381be78f | 3854 | memset(&sgs, 0, sizeof(sgs)); |
cc9fba7d | 3855 | update_sg_lb_stats(sd, group, this_cpu, idle, load_idx, sd_idle, |
1f8c553d | 3856 | local_group, cpus, balance, &sgs); |
1da177e4 | 3857 | |
37abe198 GS |
3858 | if (local_group && balance && !(*balance)) |
3859 | return; | |
783609c6 | 3860 | |
37abe198 | 3861 | sds->total_load += sgs.group_load; |
18a3885f | 3862 | sds->total_pwr += group->cpu_power; |
1da177e4 | 3863 | |
b5d978e0 PZ |
3864 | /* |
3865 | * In case the child domain prefers tasks go to siblings | |
3866 | * first, lower the group capacity to one so that we'll try | |
3867 | * and move all the excess tasks away. | |
3868 | */ | |
3869 | if (prefer_sibling) | |
bdb94aa5 | 3870 | sgs.group_capacity = min(sgs.group_capacity, 1UL); |
1da177e4 | 3871 | |
1da177e4 | 3872 | if (local_group) { |
37abe198 GS |
3873 | sds->this_load = sgs.avg_load; |
3874 | sds->this = group; | |
3875 | sds->this_nr_running = sgs.sum_nr_running; | |
3876 | sds->this_load_per_task = sgs.sum_weighted_load; | |
3877 | } else if (sgs.avg_load > sds->max_load && | |
381be78f GS |
3878 | (sgs.sum_nr_running > sgs.group_capacity || |
3879 | sgs.group_imb)) { | |
37abe198 GS |
3880 | sds->max_load = sgs.avg_load; |
3881 | sds->busiest = group; | |
3882 | sds->busiest_nr_running = sgs.sum_nr_running; | |
3883 | sds->busiest_load_per_task = sgs.sum_weighted_load; | |
3884 | sds->group_imb = sgs.group_imb; | |
48f24c4d | 3885 | } |
5c45bf27 | 3886 | |
c071df18 | 3887 | update_sd_power_savings_stats(group, sds, local_group, &sgs); |
1da177e4 LT |
3888 | group = group->next; |
3889 | } while (group != sd->groups); | |
37abe198 | 3890 | } |
1da177e4 | 3891 | |
2e6f44ae GS |
3892 | /** |
3893 | * fix_small_imbalance - Calculate the minor imbalance that exists | |
dbc523a3 GS |
3894 | * amongst the groups of a sched_domain, during |
3895 | * load balancing. | |
2e6f44ae GS |
3896 | * @sds: Statistics of the sched_domain whose imbalance is to be calculated. |
3897 | * @this_cpu: The cpu at whose sched_domain we're performing load-balance. | |
3898 | * @imbalance: Variable to store the imbalance. | |
3899 | */ | |
3900 | static inline void fix_small_imbalance(struct sd_lb_stats *sds, | |
3901 | int this_cpu, unsigned long *imbalance) | |
3902 | { | |
3903 | unsigned long tmp, pwr_now = 0, pwr_move = 0; | |
3904 | unsigned int imbn = 2; | |
3905 | ||
3906 | if (sds->this_nr_running) { | |
3907 | sds->this_load_per_task /= sds->this_nr_running; | |
3908 | if (sds->busiest_load_per_task > | |
3909 | sds->this_load_per_task) | |
3910 | imbn = 1; | |
3911 | } else | |
3912 | sds->this_load_per_task = | |
3913 | cpu_avg_load_per_task(this_cpu); | |
1da177e4 | 3914 | |
2e6f44ae GS |
3915 | if (sds->max_load - sds->this_load + sds->busiest_load_per_task >= |
3916 | sds->busiest_load_per_task * imbn) { | |
3917 | *imbalance = sds->busiest_load_per_task; | |
3918 | return; | |
3919 | } | |
908a7c1b | 3920 | |
1da177e4 | 3921 | /* |
2e6f44ae GS |
3922 | * OK, we don't have enough imbalance to justify moving tasks, |
3923 | * however we may be able to increase total CPU power used by | |
3924 | * moving them. | |
1da177e4 | 3925 | */ |
2dd73a4f | 3926 | |
18a3885f | 3927 | pwr_now += sds->busiest->cpu_power * |
2e6f44ae | 3928 | min(sds->busiest_load_per_task, sds->max_load); |
18a3885f | 3929 | pwr_now += sds->this->cpu_power * |
2e6f44ae GS |
3930 | min(sds->this_load_per_task, sds->this_load); |
3931 | pwr_now /= SCHED_LOAD_SCALE; | |
3932 | ||
3933 | /* Amount of load we'd subtract */ | |
18a3885f PZ |
3934 | tmp = (sds->busiest_load_per_task * SCHED_LOAD_SCALE) / |
3935 | sds->busiest->cpu_power; | |
2e6f44ae | 3936 | if (sds->max_load > tmp) |
18a3885f | 3937 | pwr_move += sds->busiest->cpu_power * |
2e6f44ae GS |
3938 | min(sds->busiest_load_per_task, sds->max_load - tmp); |
3939 | ||
3940 | /* Amount of load we'd add */ | |
18a3885f | 3941 | if (sds->max_load * sds->busiest->cpu_power < |
2e6f44ae | 3942 | sds->busiest_load_per_task * SCHED_LOAD_SCALE) |
18a3885f PZ |
3943 | tmp = (sds->max_load * sds->busiest->cpu_power) / |
3944 | sds->this->cpu_power; | |
2e6f44ae | 3945 | else |
18a3885f PZ |
3946 | tmp = (sds->busiest_load_per_task * SCHED_LOAD_SCALE) / |
3947 | sds->this->cpu_power; | |
3948 | pwr_move += sds->this->cpu_power * | |
2e6f44ae GS |
3949 | min(sds->this_load_per_task, sds->this_load + tmp); |
3950 | pwr_move /= SCHED_LOAD_SCALE; | |
3951 | ||
3952 | /* Move if we gain throughput */ | |
3953 | if (pwr_move > pwr_now) | |
3954 | *imbalance = sds->busiest_load_per_task; | |
3955 | } | |
dbc523a3 GS |
3956 | |
3957 | /** | |
3958 | * calculate_imbalance - Calculate the amount of imbalance present within the | |
3959 | * groups of a given sched_domain during load balance. | |
3960 | * @sds: statistics of the sched_domain whose imbalance is to be calculated. | |
3961 | * @this_cpu: Cpu for which currently load balance is being performed. | |
3962 | * @imbalance: The variable to store the imbalance. | |
3963 | */ | |
3964 | static inline void calculate_imbalance(struct sd_lb_stats *sds, int this_cpu, | |
3965 | unsigned long *imbalance) | |
3966 | { | |
3967 | unsigned long max_pull; | |
2dd73a4f PW |
3968 | /* |
3969 | * In the presence of smp nice balancing, certain scenarios can have | |
3970 | * max load less than avg load(as we skip the groups at or below | |
3971 | * its cpu_power, while calculating max_load..) | |
3972 | */ | |
dbc523a3 | 3973 | if (sds->max_load < sds->avg_load) { |
2dd73a4f | 3974 | *imbalance = 0; |
dbc523a3 | 3975 | return fix_small_imbalance(sds, this_cpu, imbalance); |
2dd73a4f | 3976 | } |
0c117f1b SS |
3977 | |
3978 | /* Don't want to pull so many tasks that a group would go idle */ | |
dbc523a3 GS |
3979 | max_pull = min(sds->max_load - sds->avg_load, |
3980 | sds->max_load - sds->busiest_load_per_task); | |
0c117f1b | 3981 | |
1da177e4 | 3982 | /* How much load to actually move to equalise the imbalance */ |
18a3885f PZ |
3983 | *imbalance = min(max_pull * sds->busiest->cpu_power, |
3984 | (sds->avg_load - sds->this_load) * sds->this->cpu_power) | |
1da177e4 LT |
3985 | / SCHED_LOAD_SCALE; |
3986 | ||
2dd73a4f PW |
3987 | /* |
3988 | * if *imbalance is less than the average load per runnable task | |
3989 | * there is no gaurantee that any tasks will be moved so we'll have | |
3990 | * a think about bumping its value to force at least one task to be | |
3991 | * moved | |
3992 | */ | |
dbc523a3 GS |
3993 | if (*imbalance < sds->busiest_load_per_task) |
3994 | return fix_small_imbalance(sds, this_cpu, imbalance); | |
1da177e4 | 3995 | |
dbc523a3 | 3996 | } |
37abe198 | 3997 | /******* find_busiest_group() helpers end here *********************/ |
1da177e4 | 3998 | |
b7bb4c9b GS |
3999 | /** |
4000 | * find_busiest_group - Returns the busiest group within the sched_domain | |
4001 | * if there is an imbalance. If there isn't an imbalance, and | |
4002 | * the user has opted for power-savings, it returns a group whose | |
4003 | * CPUs can be put to idle by rebalancing those tasks elsewhere, if | |
4004 | * such a group exists. | |
4005 | * | |
4006 | * Also calculates the amount of weighted load which should be moved | |
4007 | * to restore balance. | |
4008 | * | |
4009 | * @sd: The sched_domain whose busiest group is to be returned. | |
4010 | * @this_cpu: The cpu for which load balancing is currently being performed. | |
4011 | * @imbalance: Variable which stores amount of weighted load which should | |
4012 | * be moved to restore balance/put a group to idle. | |
4013 | * @idle: The idle status of this_cpu. | |
4014 | * @sd_idle: The idleness of sd | |
4015 | * @cpus: The set of CPUs under consideration for load-balancing. | |
4016 | * @balance: Pointer to a variable indicating if this_cpu | |
4017 | * is the appropriate cpu to perform load balancing at this_level. | |
4018 | * | |
4019 | * Returns: - the busiest group if imbalance exists. | |
4020 | * - If no imbalance and user has opted for power-savings balance, | |
4021 | * return the least loaded group whose CPUs can be | |
4022 | * put to idle by rebalancing its tasks onto our group. | |
37abe198 GS |
4023 | */ |
4024 | static struct sched_group * | |
4025 | find_busiest_group(struct sched_domain *sd, int this_cpu, | |
4026 | unsigned long *imbalance, enum cpu_idle_type idle, | |
4027 | int *sd_idle, const struct cpumask *cpus, int *balance) | |
4028 | { | |
4029 | struct sd_lb_stats sds; | |
1da177e4 | 4030 | |
37abe198 | 4031 | memset(&sds, 0, sizeof(sds)); |
1da177e4 | 4032 | |
37abe198 GS |
4033 | /* |
4034 | * Compute the various statistics relavent for load balancing at | |
4035 | * this level. | |
4036 | */ | |
4037 | update_sd_lb_stats(sd, this_cpu, idle, sd_idle, cpus, | |
4038 | balance, &sds); | |
4039 | ||
b7bb4c9b GS |
4040 | /* Cases where imbalance does not exist from POV of this_cpu */ |
4041 | /* 1) this_cpu is not the appropriate cpu to perform load balancing | |
4042 | * at this level. | |
4043 | * 2) There is no busy sibling group to pull from. | |
4044 | * 3) This group is the busiest group. | |
4045 | * 4) This group is more busy than the avg busieness at this | |
4046 | * sched_domain. | |
4047 | * 5) The imbalance is within the specified limit. | |
4048 | * 6) Any rebalance would lead to ping-pong | |
4049 | */ | |
37abe198 GS |
4050 | if (balance && !(*balance)) |
4051 | goto ret; | |
1da177e4 | 4052 | |
b7bb4c9b GS |
4053 | if (!sds.busiest || sds.busiest_nr_running == 0) |
4054 | goto out_balanced; | |
1da177e4 | 4055 | |
b7bb4c9b | 4056 | if (sds.this_load >= sds.max_load) |
1da177e4 | 4057 | goto out_balanced; |
1da177e4 | 4058 | |
222d656d | 4059 | sds.avg_load = (SCHED_LOAD_SCALE * sds.total_load) / sds.total_pwr; |
1da177e4 | 4060 | |
b7bb4c9b GS |
4061 | if (sds.this_load >= sds.avg_load) |
4062 | goto out_balanced; | |
4063 | ||
4064 | if (100 * sds.max_load <= sd->imbalance_pct * sds.this_load) | |
1da177e4 LT |
4065 | goto out_balanced; |
4066 | ||
222d656d GS |
4067 | sds.busiest_load_per_task /= sds.busiest_nr_running; |
4068 | if (sds.group_imb) | |
4069 | sds.busiest_load_per_task = | |
4070 | min(sds.busiest_load_per_task, sds.avg_load); | |
908a7c1b | 4071 | |
1da177e4 LT |
4072 | /* |
4073 | * We're trying to get all the cpus to the average_load, so we don't | |
4074 | * want to push ourselves above the average load, nor do we wish to | |
4075 | * reduce the max loaded cpu below the average load, as either of these | |
4076 | * actions would just result in more rebalancing later, and ping-pong | |
4077 | * tasks around. Thus we look for the minimum possible imbalance. | |
4078 | * Negative imbalances (*we* are more loaded than anyone else) will | |
4079 | * be counted as no imbalance for these purposes -- we can't fix that | |
41a2d6cf | 4080 | * by pulling tasks to us. Be careful of negative numbers as they'll |
1da177e4 LT |
4081 | * appear as very large values with unsigned longs. |
4082 | */ | |
222d656d | 4083 | if (sds.max_load <= sds.busiest_load_per_task) |
2dd73a4f PW |
4084 | goto out_balanced; |
4085 | ||
dbc523a3 GS |
4086 | /* Looks like there is an imbalance. Compute it */ |
4087 | calculate_imbalance(&sds, this_cpu, imbalance); | |
222d656d | 4088 | return sds.busiest; |
1da177e4 LT |
4089 | |
4090 | out_balanced: | |
c071df18 GS |
4091 | /* |
4092 | * There is no obvious imbalance. But check if we can do some balancing | |
4093 | * to save power. | |
4094 | */ | |
4095 | if (check_power_save_busiest_group(&sds, this_cpu, imbalance)) | |
4096 | return sds.busiest; | |
783609c6 | 4097 | ret: |
1da177e4 LT |
4098 | *imbalance = 0; |
4099 | return NULL; | |
4100 | } | |
4101 | ||
4102 | /* | |
4103 | * find_busiest_queue - find the busiest runqueue among the cpus in group. | |
4104 | */ | |
70b97a7f | 4105 | static struct rq * |
d15bcfdb | 4106 | find_busiest_queue(struct sched_group *group, enum cpu_idle_type idle, |
96f874e2 | 4107 | unsigned long imbalance, const struct cpumask *cpus) |
1da177e4 | 4108 | { |
70b97a7f | 4109 | struct rq *busiest = NULL, *rq; |
2dd73a4f | 4110 | unsigned long max_load = 0; |
1da177e4 LT |
4111 | int i; |
4112 | ||
758b2cdc | 4113 | for_each_cpu(i, sched_group_cpus(group)) { |
bdb94aa5 PZ |
4114 | unsigned long power = power_of(i); |
4115 | unsigned long capacity = DIV_ROUND_CLOSEST(power, SCHED_LOAD_SCALE); | |
dd41f596 | 4116 | unsigned long wl; |
0a2966b4 | 4117 | |
96f874e2 | 4118 | if (!cpumask_test_cpu(i, cpus)) |
0a2966b4 CL |
4119 | continue; |
4120 | ||
48f24c4d | 4121 | rq = cpu_rq(i); |
9000f05c | 4122 | wl = weighted_cpuload(i); |
2dd73a4f | 4123 | |
9000f05c SS |
4124 | /* |
4125 | * When comparing with imbalance, use weighted_cpuload() | |
4126 | * which is not scaled with the cpu power. | |
4127 | */ | |
bdb94aa5 | 4128 | if (capacity && rq->nr_running == 1 && wl > imbalance) |
2dd73a4f | 4129 | continue; |
1da177e4 | 4130 | |
9000f05c SS |
4131 | /* |
4132 | * For the load comparisons with the other cpu's, consider | |
4133 | * the weighted_cpuload() scaled with the cpu power, so that | |
4134 | * the load can be moved away from the cpu that is potentially | |
4135 | * running at a lower capacity. | |
4136 | */ | |
4137 | wl = (wl * SCHED_LOAD_SCALE) / power; | |
4138 | ||
dd41f596 IM |
4139 | if (wl > max_load) { |
4140 | max_load = wl; | |
48f24c4d | 4141 | busiest = rq; |
1da177e4 LT |
4142 | } |
4143 | } | |
4144 | ||
4145 | return busiest; | |
4146 | } | |
4147 | ||
77391d71 NP |
4148 | /* |
4149 | * Max backoff if we encounter pinned tasks. Pretty arbitrary value, but | |
4150 | * so long as it is large enough. | |
4151 | */ | |
4152 | #define MAX_PINNED_INTERVAL 512 | |
4153 | ||
df7c8e84 RR |
4154 | /* Working cpumask for load_balance and load_balance_newidle. */ |
4155 | static DEFINE_PER_CPU(cpumask_var_t, load_balance_tmpmask); | |
4156 | ||
1da177e4 LT |
4157 | /* |
4158 | * Check this_cpu to ensure it is balanced within domain. Attempt to move | |
4159 | * tasks if there is an imbalance. | |
1da177e4 | 4160 | */ |
70b97a7f | 4161 | static int load_balance(int this_cpu, struct rq *this_rq, |
d15bcfdb | 4162 | struct sched_domain *sd, enum cpu_idle_type idle, |
df7c8e84 | 4163 | int *balance) |
1da177e4 | 4164 | { |
43010659 | 4165 | int ld_moved, all_pinned = 0, active_balance = 0, sd_idle = 0; |
1da177e4 | 4166 | struct sched_group *group; |
1da177e4 | 4167 | unsigned long imbalance; |
70b97a7f | 4168 | struct rq *busiest; |
fe2eea3f | 4169 | unsigned long flags; |
df7c8e84 | 4170 | struct cpumask *cpus = __get_cpu_var(load_balance_tmpmask); |
5969fe06 | 4171 | |
6ad4c188 | 4172 | cpumask_copy(cpus, cpu_active_mask); |
7c16ec58 | 4173 | |
89c4710e SS |
4174 | /* |
4175 | * When power savings policy is enabled for the parent domain, idle | |
4176 | * sibling can pick up load irrespective of busy siblings. In this case, | |
dd41f596 | 4177 | * let the state of idle sibling percolate up as CPU_IDLE, instead of |
d15bcfdb | 4178 | * portraying it as CPU_NOT_IDLE. |
89c4710e | 4179 | */ |
d15bcfdb | 4180 | if (idle != CPU_NOT_IDLE && sd->flags & SD_SHARE_CPUPOWER && |
89c4710e | 4181 | !test_sd_parent(sd, SD_POWERSAVINGS_BALANCE)) |
5969fe06 | 4182 | sd_idle = 1; |
1da177e4 | 4183 | |
2d72376b | 4184 | schedstat_inc(sd, lb_count[idle]); |
1da177e4 | 4185 | |
0a2966b4 | 4186 | redo: |
c8cba857 | 4187 | update_shares(sd); |
0a2966b4 | 4188 | group = find_busiest_group(sd, this_cpu, &imbalance, idle, &sd_idle, |
7c16ec58 | 4189 | cpus, balance); |
783609c6 | 4190 | |
06066714 | 4191 | if (*balance == 0) |
783609c6 | 4192 | goto out_balanced; |
783609c6 | 4193 | |
1da177e4 LT |
4194 | if (!group) { |
4195 | schedstat_inc(sd, lb_nobusyg[idle]); | |
4196 | goto out_balanced; | |
4197 | } | |
4198 | ||
7c16ec58 | 4199 | busiest = find_busiest_queue(group, idle, imbalance, cpus); |
1da177e4 LT |
4200 | if (!busiest) { |
4201 | schedstat_inc(sd, lb_nobusyq[idle]); | |
4202 | goto out_balanced; | |
4203 | } | |
4204 | ||
db935dbd | 4205 | BUG_ON(busiest == this_rq); |
1da177e4 LT |
4206 | |
4207 | schedstat_add(sd, lb_imbalance[idle], imbalance); | |
4208 | ||
43010659 | 4209 | ld_moved = 0; |
1da177e4 LT |
4210 | if (busiest->nr_running > 1) { |
4211 | /* | |
4212 | * Attempt to move tasks. If find_busiest_group has found | |
4213 | * an imbalance but busiest->nr_running <= 1, the group is | |
43010659 | 4214 | * still unbalanced. ld_moved simply stays zero, so it is |
1da177e4 LT |
4215 | * correctly treated as an imbalance. |
4216 | */ | |
fe2eea3f | 4217 | local_irq_save(flags); |
e17224bf | 4218 | double_rq_lock(this_rq, busiest); |
43010659 | 4219 | ld_moved = move_tasks(this_rq, this_cpu, busiest, |
48f24c4d | 4220 | imbalance, sd, idle, &all_pinned); |
e17224bf | 4221 | double_rq_unlock(this_rq, busiest); |
fe2eea3f | 4222 | local_irq_restore(flags); |
81026794 | 4223 | |
46cb4b7c SS |
4224 | /* |
4225 | * some other cpu did the load balance for us. | |
4226 | */ | |
43010659 | 4227 | if (ld_moved && this_cpu != smp_processor_id()) |
46cb4b7c SS |
4228 | resched_cpu(this_cpu); |
4229 | ||
81026794 | 4230 | /* All tasks on this runqueue were pinned by CPU affinity */ |
0a2966b4 | 4231 | if (unlikely(all_pinned)) { |
96f874e2 RR |
4232 | cpumask_clear_cpu(cpu_of(busiest), cpus); |
4233 | if (!cpumask_empty(cpus)) | |
0a2966b4 | 4234 | goto redo; |
81026794 | 4235 | goto out_balanced; |
0a2966b4 | 4236 | } |
1da177e4 | 4237 | } |
81026794 | 4238 | |
43010659 | 4239 | if (!ld_moved) { |
1da177e4 LT |
4240 | schedstat_inc(sd, lb_failed[idle]); |
4241 | sd->nr_balance_failed++; | |
4242 | ||
4243 | if (unlikely(sd->nr_balance_failed > sd->cache_nice_tries+2)) { | |
1da177e4 | 4244 | |
05fa785c | 4245 | raw_spin_lock_irqsave(&busiest->lock, flags); |
fa3b6ddc SS |
4246 | |
4247 | /* don't kick the migration_thread, if the curr | |
4248 | * task on busiest cpu can't be moved to this_cpu | |
4249 | */ | |
96f874e2 RR |
4250 | if (!cpumask_test_cpu(this_cpu, |
4251 | &busiest->curr->cpus_allowed)) { | |
05fa785c TG |
4252 | raw_spin_unlock_irqrestore(&busiest->lock, |
4253 | flags); | |
fa3b6ddc SS |
4254 | all_pinned = 1; |
4255 | goto out_one_pinned; | |
4256 | } | |
4257 | ||
1da177e4 LT |
4258 | if (!busiest->active_balance) { |
4259 | busiest->active_balance = 1; | |
4260 | busiest->push_cpu = this_cpu; | |
81026794 | 4261 | active_balance = 1; |
1da177e4 | 4262 | } |
05fa785c | 4263 | raw_spin_unlock_irqrestore(&busiest->lock, flags); |
81026794 | 4264 | if (active_balance) |
1da177e4 LT |
4265 | wake_up_process(busiest->migration_thread); |
4266 | ||
4267 | /* | |
4268 | * We've kicked active balancing, reset the failure | |
4269 | * counter. | |
4270 | */ | |
39507451 | 4271 | sd->nr_balance_failed = sd->cache_nice_tries+1; |
1da177e4 | 4272 | } |
81026794 | 4273 | } else |
1da177e4 LT |
4274 | sd->nr_balance_failed = 0; |
4275 | ||
81026794 | 4276 | if (likely(!active_balance)) { |
1da177e4 LT |
4277 | /* We were unbalanced, so reset the balancing interval */ |
4278 | sd->balance_interval = sd->min_interval; | |
81026794 NP |
4279 | } else { |
4280 | /* | |
4281 | * If we've begun active balancing, start to back off. This | |
4282 | * case may not be covered by the all_pinned logic if there | |
4283 | * is only 1 task on the busy runqueue (because we don't call | |
4284 | * move_tasks). | |
4285 | */ | |
4286 | if (sd->balance_interval < sd->max_interval) | |
4287 | sd->balance_interval *= 2; | |
1da177e4 LT |
4288 | } |
4289 | ||
43010659 | 4290 | if (!ld_moved && !sd_idle && sd->flags & SD_SHARE_CPUPOWER && |
89c4710e | 4291 | !test_sd_parent(sd, SD_POWERSAVINGS_BALANCE)) |
c09595f6 PZ |
4292 | ld_moved = -1; |
4293 | ||
4294 | goto out; | |
1da177e4 LT |
4295 | |
4296 | out_balanced: | |
1da177e4 LT |
4297 | schedstat_inc(sd, lb_balanced[idle]); |
4298 | ||
16cfb1c0 | 4299 | sd->nr_balance_failed = 0; |
fa3b6ddc SS |
4300 | |
4301 | out_one_pinned: | |
1da177e4 | 4302 | /* tune up the balancing interval */ |
77391d71 NP |
4303 | if ((all_pinned && sd->balance_interval < MAX_PINNED_INTERVAL) || |
4304 | (sd->balance_interval < sd->max_interval)) | |
1da177e4 LT |
4305 | sd->balance_interval *= 2; |
4306 | ||
48f24c4d | 4307 | if (!sd_idle && sd->flags & SD_SHARE_CPUPOWER && |
89c4710e | 4308 | !test_sd_parent(sd, SD_POWERSAVINGS_BALANCE)) |
c09595f6 PZ |
4309 | ld_moved = -1; |
4310 | else | |
4311 | ld_moved = 0; | |
4312 | out: | |
c8cba857 PZ |
4313 | if (ld_moved) |
4314 | update_shares(sd); | |
c09595f6 | 4315 | return ld_moved; |
1da177e4 LT |
4316 | } |
4317 | ||
4318 | /* | |
4319 | * Check this_cpu to ensure it is balanced within domain. Attempt to move | |
4320 | * tasks if there is an imbalance. | |
4321 | * | |
d15bcfdb | 4322 | * Called from schedule when this_rq is about to become idle (CPU_NEWLY_IDLE). |
1da177e4 LT |
4323 | * this_rq is locked. |
4324 | */ | |
48f24c4d | 4325 | static int |
df7c8e84 | 4326 | load_balance_newidle(int this_cpu, struct rq *this_rq, struct sched_domain *sd) |
1da177e4 LT |
4327 | { |
4328 | struct sched_group *group; | |
70b97a7f | 4329 | struct rq *busiest = NULL; |
1da177e4 | 4330 | unsigned long imbalance; |
43010659 | 4331 | int ld_moved = 0; |
5969fe06 | 4332 | int sd_idle = 0; |
969bb4e4 | 4333 | int all_pinned = 0; |
df7c8e84 | 4334 | struct cpumask *cpus = __get_cpu_var(load_balance_tmpmask); |
7c16ec58 | 4335 | |
6ad4c188 | 4336 | cpumask_copy(cpus, cpu_active_mask); |
5969fe06 | 4337 | |
89c4710e SS |
4338 | /* |
4339 | * When power savings policy is enabled for the parent domain, idle | |
4340 | * sibling can pick up load irrespective of busy siblings. In this case, | |
4341 | * let the state of idle sibling percolate up as IDLE, instead of | |
d15bcfdb | 4342 | * portraying it as CPU_NOT_IDLE. |
89c4710e SS |
4343 | */ |
4344 | if (sd->flags & SD_SHARE_CPUPOWER && | |
4345 | !test_sd_parent(sd, SD_POWERSAVINGS_BALANCE)) | |
5969fe06 | 4346 | sd_idle = 1; |
1da177e4 | 4347 | |
2d72376b | 4348 | schedstat_inc(sd, lb_count[CPU_NEWLY_IDLE]); |
0a2966b4 | 4349 | redo: |
3e5459b4 | 4350 | update_shares_locked(this_rq, sd); |
d15bcfdb | 4351 | group = find_busiest_group(sd, this_cpu, &imbalance, CPU_NEWLY_IDLE, |
7c16ec58 | 4352 | &sd_idle, cpus, NULL); |
1da177e4 | 4353 | if (!group) { |
d15bcfdb | 4354 | schedstat_inc(sd, lb_nobusyg[CPU_NEWLY_IDLE]); |
16cfb1c0 | 4355 | goto out_balanced; |
1da177e4 LT |
4356 | } |
4357 | ||
7c16ec58 | 4358 | busiest = find_busiest_queue(group, CPU_NEWLY_IDLE, imbalance, cpus); |
db935dbd | 4359 | if (!busiest) { |
d15bcfdb | 4360 | schedstat_inc(sd, lb_nobusyq[CPU_NEWLY_IDLE]); |
16cfb1c0 | 4361 | goto out_balanced; |
1da177e4 LT |
4362 | } |
4363 | ||
db935dbd NP |
4364 | BUG_ON(busiest == this_rq); |
4365 | ||
d15bcfdb | 4366 | schedstat_add(sd, lb_imbalance[CPU_NEWLY_IDLE], imbalance); |
d6d5cfaf | 4367 | |
43010659 | 4368 | ld_moved = 0; |
d6d5cfaf NP |
4369 | if (busiest->nr_running > 1) { |
4370 | /* Attempt to move tasks */ | |
4371 | double_lock_balance(this_rq, busiest); | |
6e82a3be IM |
4372 | /* this_rq->clock is already updated */ |
4373 | update_rq_clock(busiest); | |
43010659 | 4374 | ld_moved = move_tasks(this_rq, this_cpu, busiest, |
969bb4e4 SS |
4375 | imbalance, sd, CPU_NEWLY_IDLE, |
4376 | &all_pinned); | |
1b12bbc7 | 4377 | double_unlock_balance(this_rq, busiest); |
0a2966b4 | 4378 | |
969bb4e4 | 4379 | if (unlikely(all_pinned)) { |
96f874e2 RR |
4380 | cpumask_clear_cpu(cpu_of(busiest), cpus); |
4381 | if (!cpumask_empty(cpus)) | |
0a2966b4 CL |
4382 | goto redo; |
4383 | } | |
d6d5cfaf NP |
4384 | } |
4385 | ||
43010659 | 4386 | if (!ld_moved) { |
36dffab6 | 4387 | int active_balance = 0; |
ad273b32 | 4388 | |
d15bcfdb | 4389 | schedstat_inc(sd, lb_failed[CPU_NEWLY_IDLE]); |
89c4710e SS |
4390 | if (!sd_idle && sd->flags & SD_SHARE_CPUPOWER && |
4391 | !test_sd_parent(sd, SD_POWERSAVINGS_BALANCE)) | |
5969fe06 | 4392 | return -1; |
ad273b32 VS |
4393 | |
4394 | if (sched_mc_power_savings < POWERSAVINGS_BALANCE_WAKEUP) | |
4395 | return -1; | |
4396 | ||
4397 | if (sd->nr_balance_failed++ < 2) | |
4398 | return -1; | |
4399 | ||
4400 | /* | |
4401 | * The only task running in a non-idle cpu can be moved to this | |
4402 | * cpu in an attempt to completely freeup the other CPU | |
4403 | * package. The same method used to move task in load_balance() | |
4404 | * have been extended for load_balance_newidle() to speedup | |
4405 | * consolidation at sched_mc=POWERSAVINGS_BALANCE_WAKEUP (2) | |
4406 | * | |
4407 | * The package power saving logic comes from | |
4408 | * find_busiest_group(). If there are no imbalance, then | |
4409 | * f_b_g() will return NULL. However when sched_mc={1,2} then | |
4410 | * f_b_g() will select a group from which a running task may be | |
4411 | * pulled to this cpu in order to make the other package idle. | |
4412 | * If there is no opportunity to make a package idle and if | |
4413 | * there are no imbalance, then f_b_g() will return NULL and no | |
4414 | * action will be taken in load_balance_newidle(). | |
4415 | * | |
4416 | * Under normal task pull operation due to imbalance, there | |
4417 | * will be more than one task in the source run queue and | |
4418 | * move_tasks() will succeed. ld_moved will be true and this | |
4419 | * active balance code will not be triggered. | |
4420 | */ | |
4421 | ||
4422 | /* Lock busiest in correct order while this_rq is held */ | |
4423 | double_lock_balance(this_rq, busiest); | |
4424 | ||
4425 | /* | |
4426 | * don't kick the migration_thread, if the curr | |
4427 | * task on busiest cpu can't be moved to this_cpu | |
4428 | */ | |
6ca09dfc | 4429 | if (!cpumask_test_cpu(this_cpu, &busiest->curr->cpus_allowed)) { |
ad273b32 VS |
4430 | double_unlock_balance(this_rq, busiest); |
4431 | all_pinned = 1; | |
4432 | return ld_moved; | |
4433 | } | |
4434 | ||
4435 | if (!busiest->active_balance) { | |
4436 | busiest->active_balance = 1; | |
4437 | busiest->push_cpu = this_cpu; | |
4438 | active_balance = 1; | |
4439 | } | |
4440 | ||
4441 | double_unlock_balance(this_rq, busiest); | |
da8d5089 PZ |
4442 | /* |
4443 | * Should not call ttwu while holding a rq->lock | |
4444 | */ | |
05fa785c | 4445 | raw_spin_unlock(&this_rq->lock); |
ad273b32 VS |
4446 | if (active_balance) |
4447 | wake_up_process(busiest->migration_thread); | |
05fa785c | 4448 | raw_spin_lock(&this_rq->lock); |
ad273b32 | 4449 | |
5969fe06 | 4450 | } else |
16cfb1c0 | 4451 | sd->nr_balance_failed = 0; |
1da177e4 | 4452 | |
3e5459b4 | 4453 | update_shares_locked(this_rq, sd); |
43010659 | 4454 | return ld_moved; |
16cfb1c0 NP |
4455 | |
4456 | out_balanced: | |
d15bcfdb | 4457 | schedstat_inc(sd, lb_balanced[CPU_NEWLY_IDLE]); |
48f24c4d | 4458 | if (!sd_idle && sd->flags & SD_SHARE_CPUPOWER && |
89c4710e | 4459 | !test_sd_parent(sd, SD_POWERSAVINGS_BALANCE)) |
5969fe06 | 4460 | return -1; |
16cfb1c0 | 4461 | sd->nr_balance_failed = 0; |
48f24c4d | 4462 | |
16cfb1c0 | 4463 | return 0; |
1da177e4 LT |
4464 | } |
4465 | ||
4466 | /* | |
4467 | * idle_balance is called by schedule() if this_cpu is about to become | |
4468 | * idle. Attempts to pull tasks from other CPUs. | |
4469 | */ | |
70b97a7f | 4470 | static void idle_balance(int this_cpu, struct rq *this_rq) |
1da177e4 LT |
4471 | { |
4472 | struct sched_domain *sd; | |
efbe027e | 4473 | int pulled_task = 0; |
dd41f596 | 4474 | unsigned long next_balance = jiffies + HZ; |
1da177e4 | 4475 | |
1b9508f6 MG |
4476 | this_rq->idle_stamp = this_rq->clock; |
4477 | ||
4478 | if (this_rq->avg_idle < sysctl_sched_migration_cost) | |
4479 | return; | |
4480 | ||
1da177e4 | 4481 | for_each_domain(this_cpu, sd) { |
92c4ca5c CL |
4482 | unsigned long interval; |
4483 | ||
4484 | if (!(sd->flags & SD_LOAD_BALANCE)) | |
4485 | continue; | |
4486 | ||
4487 | if (sd->flags & SD_BALANCE_NEWIDLE) | |
48f24c4d | 4488 | /* If we've pulled tasks over stop searching: */ |
7c16ec58 | 4489 | pulled_task = load_balance_newidle(this_cpu, this_rq, |
df7c8e84 | 4490 | sd); |
92c4ca5c CL |
4491 | |
4492 | interval = msecs_to_jiffies(sd->balance_interval); | |
4493 | if (time_after(next_balance, sd->last_balance + interval)) | |
4494 | next_balance = sd->last_balance + interval; | |
1b9508f6 MG |
4495 | if (pulled_task) { |
4496 | this_rq->idle_stamp = 0; | |
92c4ca5c | 4497 | break; |
1b9508f6 | 4498 | } |
1da177e4 | 4499 | } |
dd41f596 | 4500 | if (pulled_task || time_after(jiffies, this_rq->next_balance)) { |
1bd77f2d CL |
4501 | /* |
4502 | * We are going idle. next_balance may be set based on | |
4503 | * a busy processor. So reset next_balance. | |
4504 | */ | |
4505 | this_rq->next_balance = next_balance; | |
dd41f596 | 4506 | } |
1da177e4 LT |
4507 | } |
4508 | ||
4509 | /* | |
4510 | * active_load_balance is run by migration threads. It pushes running tasks | |
4511 | * off the busiest CPU onto idle CPUs. It requires at least 1 task to be | |
4512 | * running on each physical CPU where possible, and avoids physical / | |
4513 | * logical imbalances. | |
4514 | * | |
4515 | * Called with busiest_rq locked. | |
4516 | */ | |
70b97a7f | 4517 | static void active_load_balance(struct rq *busiest_rq, int busiest_cpu) |
1da177e4 | 4518 | { |
39507451 | 4519 | int target_cpu = busiest_rq->push_cpu; |
70b97a7f IM |
4520 | struct sched_domain *sd; |
4521 | struct rq *target_rq; | |
39507451 | 4522 | |
48f24c4d | 4523 | /* Is there any task to move? */ |
39507451 | 4524 | if (busiest_rq->nr_running <= 1) |
39507451 NP |
4525 | return; |
4526 | ||
4527 | target_rq = cpu_rq(target_cpu); | |
1da177e4 LT |
4528 | |
4529 | /* | |
39507451 | 4530 | * This condition is "impossible", if it occurs |
41a2d6cf | 4531 | * we need to fix it. Originally reported by |
39507451 | 4532 | * Bjorn Helgaas on a 128-cpu setup. |
1da177e4 | 4533 | */ |
39507451 | 4534 | BUG_ON(busiest_rq == target_rq); |
1da177e4 | 4535 | |
39507451 NP |
4536 | /* move a task from busiest_rq to target_rq */ |
4537 | double_lock_balance(busiest_rq, target_rq); | |
6e82a3be IM |
4538 | update_rq_clock(busiest_rq); |
4539 | update_rq_clock(target_rq); | |
39507451 NP |
4540 | |
4541 | /* Search for an sd spanning us and the target CPU. */ | |
c96d145e | 4542 | for_each_domain(target_cpu, sd) { |
39507451 | 4543 | if ((sd->flags & SD_LOAD_BALANCE) && |
758b2cdc | 4544 | cpumask_test_cpu(busiest_cpu, sched_domain_span(sd))) |
39507451 | 4545 | break; |
c96d145e | 4546 | } |
39507451 | 4547 | |
48f24c4d | 4548 | if (likely(sd)) { |
2d72376b | 4549 | schedstat_inc(sd, alb_count); |
39507451 | 4550 | |
43010659 PW |
4551 | if (move_one_task(target_rq, target_cpu, busiest_rq, |
4552 | sd, CPU_IDLE)) | |
48f24c4d IM |
4553 | schedstat_inc(sd, alb_pushed); |
4554 | else | |
4555 | schedstat_inc(sd, alb_failed); | |
4556 | } | |
1b12bbc7 | 4557 | double_unlock_balance(busiest_rq, target_rq); |
1da177e4 LT |
4558 | } |
4559 | ||
46cb4b7c SS |
4560 | #ifdef CONFIG_NO_HZ |
4561 | static struct { | |
4562 | atomic_t load_balancer; | |
7d1e6a9b | 4563 | cpumask_var_t cpu_mask; |
f711f609 | 4564 | cpumask_var_t ilb_grp_nohz_mask; |
46cb4b7c SS |
4565 | } nohz ____cacheline_aligned = { |
4566 | .load_balancer = ATOMIC_INIT(-1), | |
46cb4b7c SS |
4567 | }; |
4568 | ||
eea08f32 AB |
4569 | int get_nohz_load_balancer(void) |
4570 | { | |
4571 | return atomic_read(&nohz.load_balancer); | |
4572 | } | |
4573 | ||
f711f609 GS |
4574 | #if defined(CONFIG_SCHED_MC) || defined(CONFIG_SCHED_SMT) |
4575 | /** | |
4576 | * lowest_flag_domain - Return lowest sched_domain containing flag. | |
4577 | * @cpu: The cpu whose lowest level of sched domain is to | |
4578 | * be returned. | |
4579 | * @flag: The flag to check for the lowest sched_domain | |
4580 | * for the given cpu. | |
4581 | * | |
4582 | * Returns the lowest sched_domain of a cpu which contains the given flag. | |
4583 | */ | |
4584 | static inline struct sched_domain *lowest_flag_domain(int cpu, int flag) | |
4585 | { | |
4586 | struct sched_domain *sd; | |
4587 | ||
4588 | for_each_domain(cpu, sd) | |
4589 | if (sd && (sd->flags & flag)) | |
4590 | break; | |
4591 | ||
4592 | return sd; | |
4593 | } | |
4594 | ||
4595 | /** | |
4596 | * for_each_flag_domain - Iterates over sched_domains containing the flag. | |
4597 | * @cpu: The cpu whose domains we're iterating over. | |
4598 | * @sd: variable holding the value of the power_savings_sd | |
4599 | * for cpu. | |
4600 | * @flag: The flag to filter the sched_domains to be iterated. | |
4601 | * | |
4602 | * Iterates over all the scheduler domains for a given cpu that has the 'flag' | |
4603 | * set, starting from the lowest sched_domain to the highest. | |
4604 | */ | |
4605 | #define for_each_flag_domain(cpu, sd, flag) \ | |
4606 | for (sd = lowest_flag_domain(cpu, flag); \ | |
4607 | (sd && (sd->flags & flag)); sd = sd->parent) | |
4608 | ||
4609 | /** | |
4610 | * is_semi_idle_group - Checks if the given sched_group is semi-idle. | |
4611 | * @ilb_group: group to be checked for semi-idleness | |
4612 | * | |
4613 | * Returns: 1 if the group is semi-idle. 0 otherwise. | |
4614 | * | |
4615 | * We define a sched_group to be semi idle if it has atleast one idle-CPU | |
4616 | * and atleast one non-idle CPU. This helper function checks if the given | |
4617 | * sched_group is semi-idle or not. | |
4618 | */ | |
4619 | static inline int is_semi_idle_group(struct sched_group *ilb_group) | |
4620 | { | |
4621 | cpumask_and(nohz.ilb_grp_nohz_mask, nohz.cpu_mask, | |
4622 | sched_group_cpus(ilb_group)); | |
4623 | ||
4624 | /* | |
4625 | * A sched_group is semi-idle when it has atleast one busy cpu | |
4626 | * and atleast one idle cpu. | |
4627 | */ | |
4628 | if (cpumask_empty(nohz.ilb_grp_nohz_mask)) | |
4629 | return 0; | |
4630 | ||
4631 | if (cpumask_equal(nohz.ilb_grp_nohz_mask, sched_group_cpus(ilb_group))) | |
4632 | return 0; | |
4633 | ||
4634 | return 1; | |
4635 | } | |
4636 | /** | |
4637 | * find_new_ilb - Finds the optimum idle load balancer for nomination. | |
4638 | * @cpu: The cpu which is nominating a new idle_load_balancer. | |
4639 | * | |
4640 | * Returns: Returns the id of the idle load balancer if it exists, | |
4641 | * Else, returns >= nr_cpu_ids. | |
4642 | * | |
4643 | * This algorithm picks the idle load balancer such that it belongs to a | |
4644 | * semi-idle powersavings sched_domain. The idea is to try and avoid | |
4645 | * completely idle packages/cores just for the purpose of idle load balancing | |
4646 | * when there are other idle cpu's which are better suited for that job. | |
4647 | */ | |
4648 | static int find_new_ilb(int cpu) | |
4649 | { | |
4650 | struct sched_domain *sd; | |
4651 | struct sched_group *ilb_group; | |
4652 | ||
4653 | /* | |
4654 | * Have idle load balancer selection from semi-idle packages only | |
4655 | * when power-aware load balancing is enabled | |
4656 | */ | |
4657 | if (!(sched_smt_power_savings || sched_mc_power_savings)) | |
4658 | goto out_done; | |
4659 | ||
4660 | /* | |
4661 | * Optimize for the case when we have no idle CPUs or only one | |
4662 | * idle CPU. Don't walk the sched_domain hierarchy in such cases | |
4663 | */ | |
4664 | if (cpumask_weight(nohz.cpu_mask) < 2) | |
4665 | goto out_done; | |
4666 | ||
4667 | for_each_flag_domain(cpu, sd, SD_POWERSAVINGS_BALANCE) { | |
4668 | ilb_group = sd->groups; | |
4669 | ||
4670 | do { | |
4671 | if (is_semi_idle_group(ilb_group)) | |
4672 | return cpumask_first(nohz.ilb_grp_nohz_mask); | |
4673 | ||
4674 | ilb_group = ilb_group->next; | |
4675 | ||
4676 | } while (ilb_group != sd->groups); | |
4677 | } | |
4678 | ||
4679 | out_done: | |
4680 | return cpumask_first(nohz.cpu_mask); | |
4681 | } | |
4682 | #else /* (CONFIG_SCHED_MC || CONFIG_SCHED_SMT) */ | |
4683 | static inline int find_new_ilb(int call_cpu) | |
4684 | { | |
6e29ec57 | 4685 | return cpumask_first(nohz.cpu_mask); |
f711f609 GS |
4686 | } |
4687 | #endif | |
4688 | ||
7835b98b | 4689 | /* |
46cb4b7c SS |
4690 | * This routine will try to nominate the ilb (idle load balancing) |
4691 | * owner among the cpus whose ticks are stopped. ilb owner will do the idle | |
4692 | * load balancing on behalf of all those cpus. If all the cpus in the system | |
4693 | * go into this tickless mode, then there will be no ilb owner (as there is | |
4694 | * no need for one) and all the cpus will sleep till the next wakeup event | |
4695 | * arrives... | |
4696 | * | |
4697 | * For the ilb owner, tick is not stopped. And this tick will be used | |
4698 | * for idle load balancing. ilb owner will still be part of | |
4699 | * nohz.cpu_mask.. | |
7835b98b | 4700 | * |
46cb4b7c SS |
4701 | * While stopping the tick, this cpu will become the ilb owner if there |
4702 | * is no other owner. And will be the owner till that cpu becomes busy | |
4703 | * or if all cpus in the system stop their ticks at which point | |
4704 | * there is no need for ilb owner. | |
4705 | * | |
4706 | * When the ilb owner becomes busy, it nominates another owner, during the | |
4707 | * next busy scheduler_tick() | |
4708 | */ | |
4709 | int select_nohz_load_balancer(int stop_tick) | |
4710 | { | |
4711 | int cpu = smp_processor_id(); | |
4712 | ||
4713 | if (stop_tick) { | |
46cb4b7c SS |
4714 | cpu_rq(cpu)->in_nohz_recently = 1; |
4715 | ||
483b4ee6 SS |
4716 | if (!cpu_active(cpu)) { |
4717 | if (atomic_read(&nohz.load_balancer) != cpu) | |
4718 | return 0; | |
4719 | ||
4720 | /* | |
4721 | * If we are going offline and still the leader, | |
4722 | * give up! | |
4723 | */ | |
46cb4b7c SS |
4724 | if (atomic_cmpxchg(&nohz.load_balancer, cpu, -1) != cpu) |
4725 | BUG(); | |
483b4ee6 | 4726 | |
46cb4b7c SS |
4727 | return 0; |
4728 | } | |
4729 | ||
483b4ee6 SS |
4730 | cpumask_set_cpu(cpu, nohz.cpu_mask); |
4731 | ||
46cb4b7c | 4732 | /* time for ilb owner also to sleep */ |
6ad4c188 | 4733 | if (cpumask_weight(nohz.cpu_mask) == num_active_cpus()) { |
46cb4b7c SS |
4734 | if (atomic_read(&nohz.load_balancer) == cpu) |
4735 | atomic_set(&nohz.load_balancer, -1); | |
4736 | return 0; | |
4737 | } | |
4738 | ||
4739 | if (atomic_read(&nohz.load_balancer) == -1) { | |
4740 | /* make me the ilb owner */ | |
4741 | if (atomic_cmpxchg(&nohz.load_balancer, -1, cpu) == -1) | |
4742 | return 1; | |
e790fb0b GS |
4743 | } else if (atomic_read(&nohz.load_balancer) == cpu) { |
4744 | int new_ilb; | |
4745 | ||
4746 | if (!(sched_smt_power_savings || | |
4747 | sched_mc_power_savings)) | |
4748 | return 1; | |
4749 | /* | |
4750 | * Check to see if there is a more power-efficient | |
4751 | * ilb. | |
4752 | */ | |
4753 | new_ilb = find_new_ilb(cpu); | |
4754 | if (new_ilb < nr_cpu_ids && new_ilb != cpu) { | |
4755 | atomic_set(&nohz.load_balancer, -1); | |
4756 | resched_cpu(new_ilb); | |
4757 | return 0; | |
4758 | } | |
46cb4b7c | 4759 | return 1; |
e790fb0b | 4760 | } |
46cb4b7c | 4761 | } else { |
7d1e6a9b | 4762 | if (!cpumask_test_cpu(cpu, nohz.cpu_mask)) |
46cb4b7c SS |
4763 | return 0; |
4764 | ||
7d1e6a9b | 4765 | cpumask_clear_cpu(cpu, nohz.cpu_mask); |
46cb4b7c SS |
4766 | |
4767 | if (atomic_read(&nohz.load_balancer) == cpu) | |
4768 | if (atomic_cmpxchg(&nohz.load_balancer, cpu, -1) != cpu) | |
4769 | BUG(); | |
4770 | } | |
4771 | return 0; | |
4772 | } | |
4773 | #endif | |
4774 | ||
4775 | static DEFINE_SPINLOCK(balancing); | |
4776 | ||
4777 | /* | |
7835b98b CL |
4778 | * It checks each scheduling domain to see if it is due to be balanced, |
4779 | * and initiates a balancing operation if so. | |
4780 | * | |
4781 | * Balancing parameters are set up in arch_init_sched_domains. | |
4782 | */ | |
a9957449 | 4783 | static void rebalance_domains(int cpu, enum cpu_idle_type idle) |
7835b98b | 4784 | { |
46cb4b7c SS |
4785 | int balance = 1; |
4786 | struct rq *rq = cpu_rq(cpu); | |
7835b98b CL |
4787 | unsigned long interval; |
4788 | struct sched_domain *sd; | |
46cb4b7c | 4789 | /* Earliest time when we have to do rebalance again */ |
c9819f45 | 4790 | unsigned long next_balance = jiffies + 60*HZ; |
f549da84 | 4791 | int update_next_balance = 0; |
d07355f5 | 4792 | int need_serialize; |
1da177e4 | 4793 | |
46cb4b7c | 4794 | for_each_domain(cpu, sd) { |
1da177e4 LT |
4795 | if (!(sd->flags & SD_LOAD_BALANCE)) |
4796 | continue; | |
4797 | ||
4798 | interval = sd->balance_interval; | |
d15bcfdb | 4799 | if (idle != CPU_IDLE) |
1da177e4 LT |
4800 | interval *= sd->busy_factor; |
4801 | ||
4802 | /* scale ms to jiffies */ | |
4803 | interval = msecs_to_jiffies(interval); | |
4804 | if (unlikely(!interval)) | |
4805 | interval = 1; | |
dd41f596 IM |
4806 | if (interval > HZ*NR_CPUS/10) |
4807 | interval = HZ*NR_CPUS/10; | |
4808 | ||
d07355f5 | 4809 | need_serialize = sd->flags & SD_SERIALIZE; |
1da177e4 | 4810 | |
d07355f5 | 4811 | if (need_serialize) { |
08c183f3 CL |
4812 | if (!spin_trylock(&balancing)) |
4813 | goto out; | |
4814 | } | |
4815 | ||
c9819f45 | 4816 | if (time_after_eq(jiffies, sd->last_balance + interval)) { |
df7c8e84 | 4817 | if (load_balance(cpu, rq, sd, idle, &balance)) { |
fa3b6ddc SS |
4818 | /* |
4819 | * We've pulled tasks over so either we're no | |
5969fe06 NP |
4820 | * longer idle, or one of our SMT siblings is |
4821 | * not idle. | |
4822 | */ | |
d15bcfdb | 4823 | idle = CPU_NOT_IDLE; |
1da177e4 | 4824 | } |
1bd77f2d | 4825 | sd->last_balance = jiffies; |
1da177e4 | 4826 | } |
d07355f5 | 4827 | if (need_serialize) |
08c183f3 CL |
4828 | spin_unlock(&balancing); |
4829 | out: | |
f549da84 | 4830 | if (time_after(next_balance, sd->last_balance + interval)) { |
c9819f45 | 4831 | next_balance = sd->last_balance + interval; |
f549da84 SS |
4832 | update_next_balance = 1; |
4833 | } | |
783609c6 SS |
4834 | |
4835 | /* | |
4836 | * Stop the load balance at this level. There is another | |
4837 | * CPU in our sched group which is doing load balancing more | |
4838 | * actively. | |
4839 | */ | |
4840 | if (!balance) | |
4841 | break; | |
1da177e4 | 4842 | } |
f549da84 SS |
4843 | |
4844 | /* | |
4845 | * next_balance will be updated only when there is a need. | |
4846 | * When the cpu is attached to null domain for ex, it will not be | |
4847 | * updated. | |
4848 | */ | |
4849 | if (likely(update_next_balance)) | |
4850 | rq->next_balance = next_balance; | |
46cb4b7c SS |
4851 | } |
4852 | ||
4853 | /* | |
4854 | * run_rebalance_domains is triggered when needed from the scheduler tick. | |
4855 | * In CONFIG_NO_HZ case, the idle load balance owner will do the | |
4856 | * rebalancing for all the cpus for whom scheduler ticks are stopped. | |
4857 | */ | |
4858 | static void run_rebalance_domains(struct softirq_action *h) | |
4859 | { | |
dd41f596 IM |
4860 | int this_cpu = smp_processor_id(); |
4861 | struct rq *this_rq = cpu_rq(this_cpu); | |
4862 | enum cpu_idle_type idle = this_rq->idle_at_tick ? | |
4863 | CPU_IDLE : CPU_NOT_IDLE; | |
46cb4b7c | 4864 | |
dd41f596 | 4865 | rebalance_domains(this_cpu, idle); |
46cb4b7c SS |
4866 | |
4867 | #ifdef CONFIG_NO_HZ | |
4868 | /* | |
4869 | * If this cpu is the owner for idle load balancing, then do the | |
4870 | * balancing on behalf of the other idle cpus whose ticks are | |
4871 | * stopped. | |
4872 | */ | |
dd41f596 IM |
4873 | if (this_rq->idle_at_tick && |
4874 | atomic_read(&nohz.load_balancer) == this_cpu) { | |
46cb4b7c SS |
4875 | struct rq *rq; |
4876 | int balance_cpu; | |
4877 | ||
7d1e6a9b RR |
4878 | for_each_cpu(balance_cpu, nohz.cpu_mask) { |
4879 | if (balance_cpu == this_cpu) | |
4880 | continue; | |
4881 | ||
46cb4b7c SS |
4882 | /* |
4883 | * If this cpu gets work to do, stop the load balancing | |
4884 | * work being done for other cpus. Next load | |
4885 | * balancing owner will pick it up. | |
4886 | */ | |
4887 | if (need_resched()) | |
4888 | break; | |
4889 | ||
de0cf899 | 4890 | rebalance_domains(balance_cpu, CPU_IDLE); |
46cb4b7c SS |
4891 | |
4892 | rq = cpu_rq(balance_cpu); | |
dd41f596 IM |
4893 | if (time_after(this_rq->next_balance, rq->next_balance)) |
4894 | this_rq->next_balance = rq->next_balance; | |
46cb4b7c SS |
4895 | } |
4896 | } | |
4897 | #endif | |
4898 | } | |
4899 | ||
8a0be9ef FW |
4900 | static inline int on_null_domain(int cpu) |
4901 | { | |
4902 | return !rcu_dereference(cpu_rq(cpu)->sd); | |
4903 | } | |
4904 | ||
46cb4b7c SS |
4905 | /* |
4906 | * Trigger the SCHED_SOFTIRQ if it is time to do periodic load balancing. | |
4907 | * | |
4908 | * In case of CONFIG_NO_HZ, this is the place where we nominate a new | |
4909 | * idle load balancing owner or decide to stop the periodic load balancing, | |
4910 | * if the whole system is idle. | |
4911 | */ | |
dd41f596 | 4912 | static inline void trigger_load_balance(struct rq *rq, int cpu) |
46cb4b7c | 4913 | { |
46cb4b7c SS |
4914 | #ifdef CONFIG_NO_HZ |
4915 | /* | |
4916 | * If we were in the nohz mode recently and busy at the current | |
4917 | * scheduler tick, then check if we need to nominate new idle | |
4918 | * load balancer. | |
4919 | */ | |
4920 | if (rq->in_nohz_recently && !rq->idle_at_tick) { | |
4921 | rq->in_nohz_recently = 0; | |
4922 | ||
4923 | if (atomic_read(&nohz.load_balancer) == cpu) { | |
7d1e6a9b | 4924 | cpumask_clear_cpu(cpu, nohz.cpu_mask); |
46cb4b7c SS |
4925 | atomic_set(&nohz.load_balancer, -1); |
4926 | } | |
4927 | ||
4928 | if (atomic_read(&nohz.load_balancer) == -1) { | |
f711f609 | 4929 | int ilb = find_new_ilb(cpu); |
46cb4b7c | 4930 | |
434d53b0 | 4931 | if (ilb < nr_cpu_ids) |
46cb4b7c SS |
4932 | resched_cpu(ilb); |
4933 | } | |
4934 | } | |
4935 | ||
4936 | /* | |
4937 | * If this cpu is idle and doing idle load balancing for all the | |
4938 | * cpus with ticks stopped, is it time for that to stop? | |
4939 | */ | |
4940 | if (rq->idle_at_tick && atomic_read(&nohz.load_balancer) == cpu && | |
7d1e6a9b | 4941 | cpumask_weight(nohz.cpu_mask) == num_online_cpus()) { |
46cb4b7c SS |
4942 | resched_cpu(cpu); |
4943 | return; | |
4944 | } | |
4945 | ||
4946 | /* | |
4947 | * If this cpu is idle and the idle load balancing is done by | |
4948 | * someone else, then no need raise the SCHED_SOFTIRQ | |
4949 | */ | |
4950 | if (rq->idle_at_tick && atomic_read(&nohz.load_balancer) != cpu && | |
7d1e6a9b | 4951 | cpumask_test_cpu(cpu, nohz.cpu_mask)) |
46cb4b7c SS |
4952 | return; |
4953 | #endif | |
8a0be9ef FW |
4954 | /* Don't need to rebalance while attached to NULL domain */ |
4955 | if (time_after_eq(jiffies, rq->next_balance) && | |
4956 | likely(!on_null_domain(cpu))) | |
46cb4b7c | 4957 | raise_softirq(SCHED_SOFTIRQ); |
1da177e4 | 4958 | } |
dd41f596 IM |
4959 | |
4960 | #else /* CONFIG_SMP */ | |
4961 | ||
1da177e4 LT |
4962 | /* |
4963 | * on UP we do not need to balance between CPUs: | |
4964 | */ | |
70b97a7f | 4965 | static inline void idle_balance(int cpu, struct rq *rq) |
1da177e4 LT |
4966 | { |
4967 | } | |
dd41f596 | 4968 | |
1da177e4 LT |
4969 | #endif |
4970 | ||
1da177e4 LT |
4971 | DEFINE_PER_CPU(struct kernel_stat, kstat); |
4972 | ||
4973 | EXPORT_PER_CPU_SYMBOL(kstat); | |
4974 | ||
4975 | /* | |
c5f8d995 | 4976 | * Return any ns on the sched_clock that have not yet been accounted in |
f06febc9 | 4977 | * @p in case that task is currently running. |
c5f8d995 HS |
4978 | * |
4979 | * Called with task_rq_lock() held on @rq. | |
1da177e4 | 4980 | */ |
c5f8d995 HS |
4981 | static u64 do_task_delta_exec(struct task_struct *p, struct rq *rq) |
4982 | { | |
4983 | u64 ns = 0; | |
4984 | ||
4985 | if (task_current(rq, p)) { | |
4986 | update_rq_clock(rq); | |
4987 | ns = rq->clock - p->se.exec_start; | |
4988 | if ((s64)ns < 0) | |
4989 | ns = 0; | |
4990 | } | |
4991 | ||
4992 | return ns; | |
4993 | } | |
4994 | ||
bb34d92f | 4995 | unsigned long long task_delta_exec(struct task_struct *p) |
1da177e4 | 4996 | { |
1da177e4 | 4997 | unsigned long flags; |
41b86e9c | 4998 | struct rq *rq; |
bb34d92f | 4999 | u64 ns = 0; |
48f24c4d | 5000 | |
41b86e9c | 5001 | rq = task_rq_lock(p, &flags); |
c5f8d995 HS |
5002 | ns = do_task_delta_exec(p, rq); |
5003 | task_rq_unlock(rq, &flags); | |
1508487e | 5004 | |
c5f8d995 HS |
5005 | return ns; |
5006 | } | |
f06febc9 | 5007 | |
c5f8d995 HS |
5008 | /* |
5009 | * Return accounted runtime for the task. | |
5010 | * In case the task is currently running, return the runtime plus current's | |
5011 | * pending runtime that have not been accounted yet. | |
5012 | */ | |
5013 | unsigned long long task_sched_runtime(struct task_struct *p) | |
5014 | { | |
5015 | unsigned long flags; | |
5016 | struct rq *rq; | |
5017 | u64 ns = 0; | |
5018 | ||
5019 | rq = task_rq_lock(p, &flags); | |
5020 | ns = p->se.sum_exec_runtime + do_task_delta_exec(p, rq); | |
5021 | task_rq_unlock(rq, &flags); | |
5022 | ||
5023 | return ns; | |
5024 | } | |
48f24c4d | 5025 | |
c5f8d995 HS |
5026 | /* |
5027 | * Return sum_exec_runtime for the thread group. | |
5028 | * In case the task is currently running, return the sum plus current's | |
5029 | * pending runtime that have not been accounted yet. | |
5030 | * | |
5031 | * Note that the thread group might have other running tasks as well, | |
5032 | * so the return value not includes other pending runtime that other | |
5033 | * running tasks might have. | |
5034 | */ | |
5035 | unsigned long long thread_group_sched_runtime(struct task_struct *p) | |
5036 | { | |
5037 | struct task_cputime totals; | |
5038 | unsigned long flags; | |
5039 | struct rq *rq; | |
5040 | u64 ns; | |
5041 | ||
5042 | rq = task_rq_lock(p, &flags); | |
5043 | thread_group_cputime(p, &totals); | |
5044 | ns = totals.sum_exec_runtime + do_task_delta_exec(p, rq); | |
41b86e9c | 5045 | task_rq_unlock(rq, &flags); |
48f24c4d | 5046 | |
1da177e4 LT |
5047 | return ns; |
5048 | } | |
5049 | ||
1da177e4 LT |
5050 | /* |
5051 | * Account user cpu time to a process. | |
5052 | * @p: the process that the cpu time gets accounted to | |
1da177e4 | 5053 | * @cputime: the cpu time spent in user space since the last update |
457533a7 | 5054 | * @cputime_scaled: cputime scaled by cpu frequency |
1da177e4 | 5055 | */ |
457533a7 MS |
5056 | void account_user_time(struct task_struct *p, cputime_t cputime, |
5057 | cputime_t cputime_scaled) | |
1da177e4 LT |
5058 | { |
5059 | struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat; | |
5060 | cputime64_t tmp; | |
5061 | ||
457533a7 | 5062 | /* Add user time to process. */ |
1da177e4 | 5063 | p->utime = cputime_add(p->utime, cputime); |
457533a7 | 5064 | p->utimescaled = cputime_add(p->utimescaled, cputime_scaled); |
f06febc9 | 5065 | account_group_user_time(p, cputime); |
1da177e4 LT |
5066 | |
5067 | /* Add user time to cpustat. */ | |
5068 | tmp = cputime_to_cputime64(cputime); | |
5069 | if (TASK_NICE(p) > 0) | |
5070 | cpustat->nice = cputime64_add(cpustat->nice, tmp); | |
5071 | else | |
5072 | cpustat->user = cputime64_add(cpustat->user, tmp); | |
ef12fefa BR |
5073 | |
5074 | cpuacct_update_stats(p, CPUACCT_STAT_USER, cputime); | |
49b5cf34 JL |
5075 | /* Account for user time used */ |
5076 | acct_update_integrals(p); | |
1da177e4 LT |
5077 | } |
5078 | ||
94886b84 LV |
5079 | /* |
5080 | * Account guest cpu time to a process. | |
5081 | * @p: the process that the cpu time gets accounted to | |
5082 | * @cputime: the cpu time spent in virtual machine since the last update | |
457533a7 | 5083 | * @cputime_scaled: cputime scaled by cpu frequency |
94886b84 | 5084 | */ |
457533a7 MS |
5085 | static void account_guest_time(struct task_struct *p, cputime_t cputime, |
5086 | cputime_t cputime_scaled) | |
94886b84 LV |
5087 | { |
5088 | cputime64_t tmp; | |
5089 | struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat; | |
5090 | ||
5091 | tmp = cputime_to_cputime64(cputime); | |
5092 | ||
457533a7 | 5093 | /* Add guest time to process. */ |
94886b84 | 5094 | p->utime = cputime_add(p->utime, cputime); |
457533a7 | 5095 | p->utimescaled = cputime_add(p->utimescaled, cputime_scaled); |
f06febc9 | 5096 | account_group_user_time(p, cputime); |
94886b84 LV |
5097 | p->gtime = cputime_add(p->gtime, cputime); |
5098 | ||
457533a7 | 5099 | /* Add guest time to cpustat. */ |
ce0e7b28 RO |
5100 | if (TASK_NICE(p) > 0) { |
5101 | cpustat->nice = cputime64_add(cpustat->nice, tmp); | |
5102 | cpustat->guest_nice = cputime64_add(cpustat->guest_nice, tmp); | |
5103 | } else { | |
5104 | cpustat->user = cputime64_add(cpustat->user, tmp); | |
5105 | cpustat->guest = cputime64_add(cpustat->guest, tmp); | |
5106 | } | |
94886b84 LV |
5107 | } |
5108 | ||
1da177e4 LT |
5109 | /* |
5110 | * Account system cpu time to a process. | |
5111 | * @p: the process that the cpu time gets accounted to | |
5112 | * @hardirq_offset: the offset to subtract from hardirq_count() | |
5113 | * @cputime: the cpu time spent in kernel space since the last update | |
457533a7 | 5114 | * @cputime_scaled: cputime scaled by cpu frequency |
1da177e4 LT |
5115 | */ |
5116 | void account_system_time(struct task_struct *p, int hardirq_offset, | |
457533a7 | 5117 | cputime_t cputime, cputime_t cputime_scaled) |
1da177e4 LT |
5118 | { |
5119 | struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat; | |
1da177e4 LT |
5120 | cputime64_t tmp; |
5121 | ||
983ed7a6 | 5122 | if ((p->flags & PF_VCPU) && (irq_count() - hardirq_offset == 0)) { |
457533a7 | 5123 | account_guest_time(p, cputime, cputime_scaled); |
983ed7a6 HH |
5124 | return; |
5125 | } | |
94886b84 | 5126 | |
457533a7 | 5127 | /* Add system time to process. */ |
1da177e4 | 5128 | p->stime = cputime_add(p->stime, cputime); |
457533a7 | 5129 | p->stimescaled = cputime_add(p->stimescaled, cputime_scaled); |
f06febc9 | 5130 | account_group_system_time(p, cputime); |
1da177e4 LT |
5131 | |
5132 | /* Add system time to cpustat. */ | |
5133 | tmp = cputime_to_cputime64(cputime); | |
5134 | if (hardirq_count() - hardirq_offset) | |
5135 | cpustat->irq = cputime64_add(cpustat->irq, tmp); | |
5136 | else if (softirq_count()) | |
5137 | cpustat->softirq = cputime64_add(cpustat->softirq, tmp); | |
1da177e4 | 5138 | else |
79741dd3 MS |
5139 | cpustat->system = cputime64_add(cpustat->system, tmp); |
5140 | ||
ef12fefa BR |
5141 | cpuacct_update_stats(p, CPUACCT_STAT_SYSTEM, cputime); |
5142 | ||
1da177e4 LT |
5143 | /* Account for system time used */ |
5144 | acct_update_integrals(p); | |
1da177e4 LT |
5145 | } |
5146 | ||
c66f08be | 5147 | /* |
1da177e4 | 5148 | * Account for involuntary wait time. |
1da177e4 | 5149 | * @steal: the cpu time spent in involuntary wait |
c66f08be | 5150 | */ |
79741dd3 | 5151 | void account_steal_time(cputime_t cputime) |
c66f08be | 5152 | { |
79741dd3 MS |
5153 | struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat; |
5154 | cputime64_t cputime64 = cputime_to_cputime64(cputime); | |
5155 | ||
5156 | cpustat->steal = cputime64_add(cpustat->steal, cputime64); | |
c66f08be MN |
5157 | } |
5158 | ||
1da177e4 | 5159 | /* |
79741dd3 MS |
5160 | * Account for idle time. |
5161 | * @cputime: the cpu time spent in idle wait | |
1da177e4 | 5162 | */ |
79741dd3 | 5163 | void account_idle_time(cputime_t cputime) |
1da177e4 LT |
5164 | { |
5165 | struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat; | |
79741dd3 | 5166 | cputime64_t cputime64 = cputime_to_cputime64(cputime); |
70b97a7f | 5167 | struct rq *rq = this_rq(); |
1da177e4 | 5168 | |
79741dd3 MS |
5169 | if (atomic_read(&rq->nr_iowait) > 0) |
5170 | cpustat->iowait = cputime64_add(cpustat->iowait, cputime64); | |
5171 | else | |
5172 | cpustat->idle = cputime64_add(cpustat->idle, cputime64); | |
1da177e4 LT |
5173 | } |
5174 | ||
79741dd3 MS |
5175 | #ifndef CONFIG_VIRT_CPU_ACCOUNTING |
5176 | ||
5177 | /* | |
5178 | * Account a single tick of cpu time. | |
5179 | * @p: the process that the cpu time gets accounted to | |
5180 | * @user_tick: indicates if the tick is a user or a system tick | |
5181 | */ | |
5182 | void account_process_tick(struct task_struct *p, int user_tick) | |
5183 | { | |
a42548a1 | 5184 | cputime_t one_jiffy_scaled = cputime_to_scaled(cputime_one_jiffy); |
79741dd3 MS |
5185 | struct rq *rq = this_rq(); |
5186 | ||
5187 | if (user_tick) | |
a42548a1 | 5188 | account_user_time(p, cputime_one_jiffy, one_jiffy_scaled); |
f5f293a4 | 5189 | else if ((p != rq->idle) || (irq_count() != HARDIRQ_OFFSET)) |
a42548a1 | 5190 | account_system_time(p, HARDIRQ_OFFSET, cputime_one_jiffy, |
79741dd3 MS |
5191 | one_jiffy_scaled); |
5192 | else | |
a42548a1 | 5193 | account_idle_time(cputime_one_jiffy); |
79741dd3 MS |
5194 | } |
5195 | ||
5196 | /* | |
5197 | * Account multiple ticks of steal time. | |
5198 | * @p: the process from which the cpu time has been stolen | |
5199 | * @ticks: number of stolen ticks | |
5200 | */ | |
5201 | void account_steal_ticks(unsigned long ticks) | |
5202 | { | |
5203 | account_steal_time(jiffies_to_cputime(ticks)); | |
5204 | } | |
5205 | ||
5206 | /* | |
5207 | * Account multiple ticks of idle time. | |
5208 | * @ticks: number of stolen ticks | |
5209 | */ | |
5210 | void account_idle_ticks(unsigned long ticks) | |
5211 | { | |
5212 | account_idle_time(jiffies_to_cputime(ticks)); | |
1da177e4 LT |
5213 | } |
5214 | ||
79741dd3 MS |
5215 | #endif |
5216 | ||
49048622 BS |
5217 | /* |
5218 | * Use precise platform statistics if available: | |
5219 | */ | |
5220 | #ifdef CONFIG_VIRT_CPU_ACCOUNTING | |
d180c5bc | 5221 | void task_times(struct task_struct *p, cputime_t *ut, cputime_t *st) |
49048622 | 5222 | { |
d99ca3b9 HS |
5223 | *ut = p->utime; |
5224 | *st = p->stime; | |
49048622 BS |
5225 | } |
5226 | ||
0cf55e1e | 5227 | void thread_group_times(struct task_struct *p, cputime_t *ut, cputime_t *st) |
49048622 | 5228 | { |
0cf55e1e HS |
5229 | struct task_cputime cputime; |
5230 | ||
5231 | thread_group_cputime(p, &cputime); | |
5232 | ||
5233 | *ut = cputime.utime; | |
5234 | *st = cputime.stime; | |
49048622 BS |
5235 | } |
5236 | #else | |
761b1d26 HS |
5237 | |
5238 | #ifndef nsecs_to_cputime | |
b7b20df9 | 5239 | # define nsecs_to_cputime(__nsecs) nsecs_to_jiffies(__nsecs) |
761b1d26 HS |
5240 | #endif |
5241 | ||
d180c5bc | 5242 | void task_times(struct task_struct *p, cputime_t *ut, cputime_t *st) |
49048622 | 5243 | { |
d99ca3b9 | 5244 | cputime_t rtime, utime = p->utime, total = cputime_add(utime, p->stime); |
49048622 BS |
5245 | |
5246 | /* | |
5247 | * Use CFS's precise accounting: | |
5248 | */ | |
d180c5bc | 5249 | rtime = nsecs_to_cputime(p->se.sum_exec_runtime); |
49048622 BS |
5250 | |
5251 | if (total) { | |
d180c5bc HS |
5252 | u64 temp; |
5253 | ||
5254 | temp = (u64)(rtime * utime); | |
49048622 | 5255 | do_div(temp, total); |
d180c5bc HS |
5256 | utime = (cputime_t)temp; |
5257 | } else | |
5258 | utime = rtime; | |
49048622 | 5259 | |
d180c5bc HS |
5260 | /* |
5261 | * Compare with previous values, to keep monotonicity: | |
5262 | */ | |
761b1d26 | 5263 | p->prev_utime = max(p->prev_utime, utime); |
d99ca3b9 | 5264 | p->prev_stime = max(p->prev_stime, cputime_sub(rtime, p->prev_utime)); |
49048622 | 5265 | |
d99ca3b9 HS |
5266 | *ut = p->prev_utime; |
5267 | *st = p->prev_stime; | |
49048622 BS |
5268 | } |
5269 | ||
0cf55e1e HS |
5270 | /* |
5271 | * Must be called with siglock held. | |
5272 | */ | |
5273 | void thread_group_times(struct task_struct *p, cputime_t *ut, cputime_t *st) | |
49048622 | 5274 | { |
0cf55e1e HS |
5275 | struct signal_struct *sig = p->signal; |
5276 | struct task_cputime cputime; | |
5277 | cputime_t rtime, utime, total; | |
49048622 | 5278 | |
0cf55e1e | 5279 | thread_group_cputime(p, &cputime); |
49048622 | 5280 | |
0cf55e1e HS |
5281 | total = cputime_add(cputime.utime, cputime.stime); |
5282 | rtime = nsecs_to_cputime(cputime.sum_exec_runtime); | |
49048622 | 5283 | |
0cf55e1e HS |
5284 | if (total) { |
5285 | u64 temp; | |
49048622 | 5286 | |
0cf55e1e HS |
5287 | temp = (u64)(rtime * cputime.utime); |
5288 | do_div(temp, total); | |
5289 | utime = (cputime_t)temp; | |
5290 | } else | |
5291 | utime = rtime; | |
5292 | ||
5293 | sig->prev_utime = max(sig->prev_utime, utime); | |
5294 | sig->prev_stime = max(sig->prev_stime, | |
5295 | cputime_sub(rtime, sig->prev_utime)); | |
5296 | ||
5297 | *ut = sig->prev_utime; | |
5298 | *st = sig->prev_stime; | |
49048622 | 5299 | } |
49048622 | 5300 | #endif |
49048622 | 5301 | |
7835b98b CL |
5302 | /* |
5303 | * This function gets called by the timer code, with HZ frequency. | |
5304 | * We call it with interrupts disabled. | |
5305 | * | |
5306 | * It also gets called by the fork code, when changing the parent's | |
5307 | * timeslices. | |
5308 | */ | |
5309 | void scheduler_tick(void) | |
5310 | { | |
7835b98b CL |
5311 | int cpu = smp_processor_id(); |
5312 | struct rq *rq = cpu_rq(cpu); | |
dd41f596 | 5313 | struct task_struct *curr = rq->curr; |
3e51f33f PZ |
5314 | |
5315 | sched_clock_tick(); | |
dd41f596 | 5316 | |
05fa785c | 5317 | raw_spin_lock(&rq->lock); |
3e51f33f | 5318 | update_rq_clock(rq); |
f1a438d8 | 5319 | update_cpu_load(rq); |
fa85ae24 | 5320 | curr->sched_class->task_tick(rq, curr, 0); |
05fa785c | 5321 | raw_spin_unlock(&rq->lock); |
7835b98b | 5322 | |
cdd6c482 | 5323 | perf_event_task_tick(curr, cpu); |
e220d2dc | 5324 | |
e418e1c2 | 5325 | #ifdef CONFIG_SMP |
dd41f596 IM |
5326 | rq->idle_at_tick = idle_cpu(cpu); |
5327 | trigger_load_balance(rq, cpu); | |
e418e1c2 | 5328 | #endif |
1da177e4 LT |
5329 | } |
5330 | ||
132380a0 | 5331 | notrace unsigned long get_parent_ip(unsigned long addr) |
6cd8a4bb SR |
5332 | { |
5333 | if (in_lock_functions(addr)) { | |
5334 | addr = CALLER_ADDR2; | |
5335 | if (in_lock_functions(addr)) | |
5336 | addr = CALLER_ADDR3; | |
5337 | } | |
5338 | return addr; | |
5339 | } | |
1da177e4 | 5340 | |
7e49fcce SR |
5341 | #if defined(CONFIG_PREEMPT) && (defined(CONFIG_DEBUG_PREEMPT) || \ |
5342 | defined(CONFIG_PREEMPT_TRACER)) | |
5343 | ||
43627582 | 5344 | void __kprobes add_preempt_count(int val) |
1da177e4 | 5345 | { |
6cd8a4bb | 5346 | #ifdef CONFIG_DEBUG_PREEMPT |
1da177e4 LT |
5347 | /* |
5348 | * Underflow? | |
5349 | */ | |
9a11b49a IM |
5350 | if (DEBUG_LOCKS_WARN_ON((preempt_count() < 0))) |
5351 | return; | |
6cd8a4bb | 5352 | #endif |
1da177e4 | 5353 | preempt_count() += val; |
6cd8a4bb | 5354 | #ifdef CONFIG_DEBUG_PREEMPT |
1da177e4 LT |
5355 | /* |
5356 | * Spinlock count overflowing soon? | |
5357 | */ | |
33859f7f MOS |
5358 | DEBUG_LOCKS_WARN_ON((preempt_count() & PREEMPT_MASK) >= |
5359 | PREEMPT_MASK - 10); | |
6cd8a4bb SR |
5360 | #endif |
5361 | if (preempt_count() == val) | |
5362 | trace_preempt_off(CALLER_ADDR0, get_parent_ip(CALLER_ADDR1)); | |
1da177e4 LT |
5363 | } |
5364 | EXPORT_SYMBOL(add_preempt_count); | |
5365 | ||
43627582 | 5366 | void __kprobes sub_preempt_count(int val) |
1da177e4 | 5367 | { |
6cd8a4bb | 5368 | #ifdef CONFIG_DEBUG_PREEMPT |
1da177e4 LT |
5369 | /* |
5370 | * Underflow? | |
5371 | */ | |
01e3eb82 | 5372 | if (DEBUG_LOCKS_WARN_ON(val > preempt_count())) |
9a11b49a | 5373 | return; |
1da177e4 LT |
5374 | /* |
5375 | * Is the spinlock portion underflowing? | |
5376 | */ | |
9a11b49a IM |
5377 | if (DEBUG_LOCKS_WARN_ON((val < PREEMPT_MASK) && |
5378 | !(preempt_count() & PREEMPT_MASK))) | |
5379 | return; | |
6cd8a4bb | 5380 | #endif |
9a11b49a | 5381 | |
6cd8a4bb SR |
5382 | if (preempt_count() == val) |
5383 | trace_preempt_on(CALLER_ADDR0, get_parent_ip(CALLER_ADDR1)); | |
1da177e4 LT |
5384 | preempt_count() -= val; |
5385 | } | |
5386 | EXPORT_SYMBOL(sub_preempt_count); | |
5387 | ||
5388 | #endif | |
5389 | ||
5390 | /* | |
dd41f596 | 5391 | * Print scheduling while atomic bug: |
1da177e4 | 5392 | */ |
dd41f596 | 5393 | static noinline void __schedule_bug(struct task_struct *prev) |
1da177e4 | 5394 | { |
838225b4 SS |
5395 | struct pt_regs *regs = get_irq_regs(); |
5396 | ||
3df0fc5b PZ |
5397 | printk(KERN_ERR "BUG: scheduling while atomic: %s/%d/0x%08x\n", |
5398 | prev->comm, prev->pid, preempt_count()); | |
838225b4 | 5399 | |
dd41f596 | 5400 | debug_show_held_locks(prev); |
e21f5b15 | 5401 | print_modules(); |
dd41f596 IM |
5402 | if (irqs_disabled()) |
5403 | print_irqtrace_events(prev); | |
838225b4 SS |
5404 | |
5405 | if (regs) | |
5406 | show_regs(regs); | |
5407 | else | |
5408 | dump_stack(); | |
dd41f596 | 5409 | } |
1da177e4 | 5410 | |
dd41f596 IM |
5411 | /* |
5412 | * Various schedule()-time debugging checks and statistics: | |
5413 | */ | |
5414 | static inline void schedule_debug(struct task_struct *prev) | |
5415 | { | |
1da177e4 | 5416 | /* |
41a2d6cf | 5417 | * Test if we are atomic. Since do_exit() needs to call into |
1da177e4 LT |
5418 | * schedule() atomically, we ignore that path for now. |
5419 | * Otherwise, whine if we are scheduling when we should not be. | |
5420 | */ | |
3f33a7ce | 5421 | if (unlikely(in_atomic_preempt_off() && !prev->exit_state)) |
dd41f596 IM |
5422 | __schedule_bug(prev); |
5423 | ||
1da177e4 LT |
5424 | profile_hit(SCHED_PROFILING, __builtin_return_address(0)); |
5425 | ||
2d72376b | 5426 | schedstat_inc(this_rq(), sched_count); |
b8efb561 IM |
5427 | #ifdef CONFIG_SCHEDSTATS |
5428 | if (unlikely(prev->lock_depth >= 0)) { | |
2d72376b IM |
5429 | schedstat_inc(this_rq(), bkl_count); |
5430 | schedstat_inc(prev, sched_info.bkl_count); | |
b8efb561 IM |
5431 | } |
5432 | #endif | |
dd41f596 IM |
5433 | } |
5434 | ||
6cecd084 | 5435 | static void put_prev_task(struct rq *rq, struct task_struct *prev) |
df1c99d4 | 5436 | { |
6cecd084 PZ |
5437 | if (prev->state == TASK_RUNNING) { |
5438 | u64 runtime = prev->se.sum_exec_runtime; | |
df1c99d4 | 5439 | |
6cecd084 PZ |
5440 | runtime -= prev->se.prev_sum_exec_runtime; |
5441 | runtime = min_t(u64, runtime, 2*sysctl_sched_migration_cost); | |
df1c99d4 MG |
5442 | |
5443 | /* | |
5444 | * In order to avoid avg_overlap growing stale when we are | |
5445 | * indeed overlapping and hence not getting put to sleep, grow | |
5446 | * the avg_overlap on preemption. | |
5447 | * | |
5448 | * We use the average preemption runtime because that | |
5449 | * correlates to the amount of cache footprint a task can | |
5450 | * build up. | |
5451 | */ | |
6cecd084 | 5452 | update_avg(&prev->se.avg_overlap, runtime); |
df1c99d4 | 5453 | } |
6cecd084 | 5454 | prev->sched_class->put_prev_task(rq, prev); |
df1c99d4 MG |
5455 | } |
5456 | ||
dd41f596 IM |
5457 | /* |
5458 | * Pick up the highest-prio task: | |
5459 | */ | |
5460 | static inline struct task_struct * | |
b67802ea | 5461 | pick_next_task(struct rq *rq) |
dd41f596 | 5462 | { |
5522d5d5 | 5463 | const struct sched_class *class; |
dd41f596 | 5464 | struct task_struct *p; |
1da177e4 LT |
5465 | |
5466 | /* | |
dd41f596 IM |
5467 | * Optimization: we know that if all tasks are in |
5468 | * the fair class we can call that function directly: | |
1da177e4 | 5469 | */ |
dd41f596 | 5470 | if (likely(rq->nr_running == rq->cfs.nr_running)) { |
fb8d4724 | 5471 | p = fair_sched_class.pick_next_task(rq); |
dd41f596 IM |
5472 | if (likely(p)) |
5473 | return p; | |
1da177e4 LT |
5474 | } |
5475 | ||
dd41f596 IM |
5476 | class = sched_class_highest; |
5477 | for ( ; ; ) { | |
fb8d4724 | 5478 | p = class->pick_next_task(rq); |
dd41f596 IM |
5479 | if (p) |
5480 | return p; | |
5481 | /* | |
5482 | * Will never be NULL as the idle class always | |
5483 | * returns a non-NULL p: | |
5484 | */ | |
5485 | class = class->next; | |
5486 | } | |
5487 | } | |
1da177e4 | 5488 | |
dd41f596 IM |
5489 | /* |
5490 | * schedule() is the main scheduler function. | |
5491 | */ | |
ff743345 | 5492 | asmlinkage void __sched schedule(void) |
dd41f596 IM |
5493 | { |
5494 | struct task_struct *prev, *next; | |
67ca7bde | 5495 | unsigned long *switch_count; |
dd41f596 | 5496 | struct rq *rq; |
31656519 | 5497 | int cpu; |
dd41f596 | 5498 | |
ff743345 PZ |
5499 | need_resched: |
5500 | preempt_disable(); | |
dd41f596 IM |
5501 | cpu = smp_processor_id(); |
5502 | rq = cpu_rq(cpu); | |
d6714c22 | 5503 | rcu_sched_qs(cpu); |
dd41f596 IM |
5504 | prev = rq->curr; |
5505 | switch_count = &prev->nivcsw; | |
5506 | ||
5507 | release_kernel_lock(prev); | |
5508 | need_resched_nonpreemptible: | |
5509 | ||
5510 | schedule_debug(prev); | |
1da177e4 | 5511 | |
31656519 | 5512 | if (sched_feat(HRTICK)) |
f333fdc9 | 5513 | hrtick_clear(rq); |
8f4d37ec | 5514 | |
05fa785c | 5515 | raw_spin_lock_irq(&rq->lock); |
3e51f33f | 5516 | update_rq_clock(rq); |
1e819950 | 5517 | clear_tsk_need_resched(prev); |
1da177e4 | 5518 | |
1da177e4 | 5519 | if (prev->state && !(preempt_count() & PREEMPT_ACTIVE)) { |
16882c1e | 5520 | if (unlikely(signal_pending_state(prev->state, prev))) |
1da177e4 | 5521 | prev->state = TASK_RUNNING; |
16882c1e | 5522 | else |
2e1cb74a | 5523 | deactivate_task(rq, prev, 1); |
dd41f596 | 5524 | switch_count = &prev->nvcsw; |
1da177e4 LT |
5525 | } |
5526 | ||
3f029d3c | 5527 | pre_schedule(rq, prev); |
f65eda4f | 5528 | |
dd41f596 | 5529 | if (unlikely(!rq->nr_running)) |
1da177e4 | 5530 | idle_balance(cpu, rq); |
1da177e4 | 5531 | |
df1c99d4 | 5532 | put_prev_task(rq, prev); |
b67802ea | 5533 | next = pick_next_task(rq); |
1da177e4 | 5534 | |
1da177e4 | 5535 | if (likely(prev != next)) { |
673a90a1 | 5536 | sched_info_switch(prev, next); |
cdd6c482 | 5537 | perf_event_task_sched_out(prev, next, cpu); |
673a90a1 | 5538 | |
1da177e4 LT |
5539 | rq->nr_switches++; |
5540 | rq->curr = next; | |
5541 | ++*switch_count; | |
5542 | ||
dd41f596 | 5543 | context_switch(rq, prev, next); /* unlocks the rq */ |
8f4d37ec PZ |
5544 | /* |
5545 | * the context switch might have flipped the stack from under | |
5546 | * us, hence refresh the local variables. | |
5547 | */ | |
5548 | cpu = smp_processor_id(); | |
5549 | rq = cpu_rq(cpu); | |
1da177e4 | 5550 | } else |
05fa785c | 5551 | raw_spin_unlock_irq(&rq->lock); |
1da177e4 | 5552 | |
3f029d3c | 5553 | post_schedule(rq); |
1da177e4 | 5554 | |
6d558c3a YZ |
5555 | if (unlikely(reacquire_kernel_lock(current) < 0)) { |
5556 | prev = rq->curr; | |
5557 | switch_count = &prev->nivcsw; | |
1da177e4 | 5558 | goto need_resched_nonpreemptible; |
6d558c3a | 5559 | } |
8f4d37ec | 5560 | |
1da177e4 | 5561 | preempt_enable_no_resched(); |
ff743345 | 5562 | if (need_resched()) |
1da177e4 LT |
5563 | goto need_resched; |
5564 | } | |
1da177e4 LT |
5565 | EXPORT_SYMBOL(schedule); |
5566 | ||
c08f7829 | 5567 | #ifdef CONFIG_MUTEX_SPIN_ON_OWNER |
0d66bf6d PZ |
5568 | /* |
5569 | * Look out! "owner" is an entirely speculative pointer | |
5570 | * access and not reliable. | |
5571 | */ | |
5572 | int mutex_spin_on_owner(struct mutex *lock, struct thread_info *owner) | |
5573 | { | |
5574 | unsigned int cpu; | |
5575 | struct rq *rq; | |
5576 | ||
5577 | if (!sched_feat(OWNER_SPIN)) | |
5578 | return 0; | |
5579 | ||
5580 | #ifdef CONFIG_DEBUG_PAGEALLOC | |
5581 | /* | |
5582 | * Need to access the cpu field knowing that | |
5583 | * DEBUG_PAGEALLOC could have unmapped it if | |
5584 | * the mutex owner just released it and exited. | |
5585 | */ | |
5586 | if (probe_kernel_address(&owner->cpu, cpu)) | |
5587 | goto out; | |
5588 | #else | |
5589 | cpu = owner->cpu; | |
5590 | #endif | |
5591 | ||
5592 | /* | |
5593 | * Even if the access succeeded (likely case), | |
5594 | * the cpu field may no longer be valid. | |
5595 | */ | |
5596 | if (cpu >= nr_cpumask_bits) | |
5597 | goto out; | |
5598 | ||
5599 | /* | |
5600 | * We need to validate that we can do a | |
5601 | * get_cpu() and that we have the percpu area. | |
5602 | */ | |
5603 | if (!cpu_online(cpu)) | |
5604 | goto out; | |
5605 | ||
5606 | rq = cpu_rq(cpu); | |
5607 | ||
5608 | for (;;) { | |
5609 | /* | |
5610 | * Owner changed, break to re-assess state. | |
5611 | */ | |
5612 | if (lock->owner != owner) | |
5613 | break; | |
5614 | ||
5615 | /* | |
5616 | * Is that owner really running on that cpu? | |
5617 | */ | |
5618 | if (task_thread_info(rq->curr) != owner || need_resched()) | |
5619 | return 0; | |
5620 | ||
5621 | cpu_relax(); | |
5622 | } | |
5623 | out: | |
5624 | return 1; | |
5625 | } | |
5626 | #endif | |
5627 | ||
1da177e4 LT |
5628 | #ifdef CONFIG_PREEMPT |
5629 | /* | |
2ed6e34f | 5630 | * this is the entry point to schedule() from in-kernel preemption |
41a2d6cf | 5631 | * off of preempt_enable. Kernel preemptions off return from interrupt |
1da177e4 LT |
5632 | * occur there and call schedule directly. |
5633 | */ | |
5634 | asmlinkage void __sched preempt_schedule(void) | |
5635 | { | |
5636 | struct thread_info *ti = current_thread_info(); | |
6478d880 | 5637 | |
1da177e4 LT |
5638 | /* |
5639 | * If there is a non-zero preempt_count or interrupts are disabled, | |
41a2d6cf | 5640 | * we do not want to preempt the current task. Just return.. |
1da177e4 | 5641 | */ |
beed33a8 | 5642 | if (likely(ti->preempt_count || irqs_disabled())) |
1da177e4 LT |
5643 | return; |
5644 | ||
3a5c359a AK |
5645 | do { |
5646 | add_preempt_count(PREEMPT_ACTIVE); | |
3a5c359a | 5647 | schedule(); |
3a5c359a | 5648 | sub_preempt_count(PREEMPT_ACTIVE); |
1da177e4 | 5649 | |
3a5c359a AK |
5650 | /* |
5651 | * Check again in case we missed a preemption opportunity | |
5652 | * between schedule and now. | |
5653 | */ | |
5654 | barrier(); | |
5ed0cec0 | 5655 | } while (need_resched()); |
1da177e4 | 5656 | } |
1da177e4 LT |
5657 | EXPORT_SYMBOL(preempt_schedule); |
5658 | ||
5659 | /* | |
2ed6e34f | 5660 | * this is the entry point to schedule() from kernel preemption |
1da177e4 LT |
5661 | * off of irq context. |
5662 | * Note, that this is called and return with irqs disabled. This will | |
5663 | * protect us against recursive calling from irq. | |
5664 | */ | |
5665 | asmlinkage void __sched preempt_schedule_irq(void) | |
5666 | { | |
5667 | struct thread_info *ti = current_thread_info(); | |
6478d880 | 5668 | |
2ed6e34f | 5669 | /* Catch callers which need to be fixed */ |
1da177e4 LT |
5670 | BUG_ON(ti->preempt_count || !irqs_disabled()); |
5671 | ||
3a5c359a AK |
5672 | do { |
5673 | add_preempt_count(PREEMPT_ACTIVE); | |
3a5c359a AK |
5674 | local_irq_enable(); |
5675 | schedule(); | |
5676 | local_irq_disable(); | |
3a5c359a | 5677 | sub_preempt_count(PREEMPT_ACTIVE); |
1da177e4 | 5678 | |
3a5c359a AK |
5679 | /* |
5680 | * Check again in case we missed a preemption opportunity | |
5681 | * between schedule and now. | |
5682 | */ | |
5683 | barrier(); | |
5ed0cec0 | 5684 | } while (need_resched()); |
1da177e4 LT |
5685 | } |
5686 | ||
5687 | #endif /* CONFIG_PREEMPT */ | |
5688 | ||
63859d4f | 5689 | int default_wake_function(wait_queue_t *curr, unsigned mode, int wake_flags, |
95cdf3b7 | 5690 | void *key) |
1da177e4 | 5691 | { |
63859d4f | 5692 | return try_to_wake_up(curr->private, mode, wake_flags); |
1da177e4 | 5693 | } |
1da177e4 LT |
5694 | EXPORT_SYMBOL(default_wake_function); |
5695 | ||
5696 | /* | |
41a2d6cf IM |
5697 | * The core wakeup function. Non-exclusive wakeups (nr_exclusive == 0) just |
5698 | * wake everything up. If it's an exclusive wakeup (nr_exclusive == small +ve | |
1da177e4 LT |
5699 | * number) then we wake all the non-exclusive tasks and one exclusive task. |
5700 | * | |
5701 | * There are circumstances in which we can try to wake a task which has already | |
41a2d6cf | 5702 | * started to run but is not in state TASK_RUNNING. try_to_wake_up() returns |
1da177e4 LT |
5703 | * zero in this (rare) case, and we handle it by continuing to scan the queue. |
5704 | */ | |
78ddb08f | 5705 | static void __wake_up_common(wait_queue_head_t *q, unsigned int mode, |
63859d4f | 5706 | int nr_exclusive, int wake_flags, void *key) |
1da177e4 | 5707 | { |
2e45874c | 5708 | wait_queue_t *curr, *next; |
1da177e4 | 5709 | |
2e45874c | 5710 | list_for_each_entry_safe(curr, next, &q->task_list, task_list) { |
48f24c4d IM |
5711 | unsigned flags = curr->flags; |
5712 | ||
63859d4f | 5713 | if (curr->func(curr, mode, wake_flags, key) && |
48f24c4d | 5714 | (flags & WQ_FLAG_EXCLUSIVE) && !--nr_exclusive) |
1da177e4 LT |
5715 | break; |
5716 | } | |
5717 | } | |
5718 | ||
5719 | /** | |
5720 | * __wake_up - wake up threads blocked on a waitqueue. | |
5721 | * @q: the waitqueue | |
5722 | * @mode: which threads | |
5723 | * @nr_exclusive: how many wake-one or wake-many threads to wake up | |
67be2dd1 | 5724 | * @key: is directly passed to the wakeup function |
50fa610a DH |
5725 | * |
5726 | * It may be assumed that this function implies a write memory barrier before | |
5727 | * changing the task state if and only if any tasks are woken up. | |
1da177e4 | 5728 | */ |
7ad5b3a5 | 5729 | void __wake_up(wait_queue_head_t *q, unsigned int mode, |
95cdf3b7 | 5730 | int nr_exclusive, void *key) |
1da177e4 LT |
5731 | { |
5732 | unsigned long flags; | |
5733 | ||
5734 | spin_lock_irqsave(&q->lock, flags); | |
5735 | __wake_up_common(q, mode, nr_exclusive, 0, key); | |
5736 | spin_unlock_irqrestore(&q->lock, flags); | |
5737 | } | |
1da177e4 LT |
5738 | EXPORT_SYMBOL(__wake_up); |
5739 | ||
5740 | /* | |
5741 | * Same as __wake_up but called with the spinlock in wait_queue_head_t held. | |
5742 | */ | |
7ad5b3a5 | 5743 | void __wake_up_locked(wait_queue_head_t *q, unsigned int mode) |
1da177e4 LT |
5744 | { |
5745 | __wake_up_common(q, mode, 1, 0, NULL); | |
5746 | } | |
5747 | ||
4ede816a DL |
5748 | void __wake_up_locked_key(wait_queue_head_t *q, unsigned int mode, void *key) |
5749 | { | |
5750 | __wake_up_common(q, mode, 1, 0, key); | |
5751 | } | |
5752 | ||
1da177e4 | 5753 | /** |
4ede816a | 5754 | * __wake_up_sync_key - wake up threads blocked on a waitqueue. |
1da177e4 LT |
5755 | * @q: the waitqueue |
5756 | * @mode: which threads | |
5757 | * @nr_exclusive: how many wake-one or wake-many threads to wake up | |
4ede816a | 5758 | * @key: opaque value to be passed to wakeup targets |
1da177e4 LT |
5759 | * |
5760 | * The sync wakeup differs that the waker knows that it will schedule | |
5761 | * away soon, so while the target thread will be woken up, it will not | |
5762 | * be migrated to another CPU - ie. the two threads are 'synchronized' | |
5763 | * with each other. This can prevent needless bouncing between CPUs. | |
5764 | * | |
5765 | * On UP it can prevent extra preemption. | |
50fa610a DH |
5766 | * |
5767 | * It may be assumed that this function implies a write memory barrier before | |
5768 | * changing the task state if and only if any tasks are woken up. | |
1da177e4 | 5769 | */ |
4ede816a DL |
5770 | void __wake_up_sync_key(wait_queue_head_t *q, unsigned int mode, |
5771 | int nr_exclusive, void *key) | |
1da177e4 LT |
5772 | { |
5773 | unsigned long flags; | |
7d478721 | 5774 | int wake_flags = WF_SYNC; |
1da177e4 LT |
5775 | |
5776 | if (unlikely(!q)) | |
5777 | return; | |
5778 | ||
5779 | if (unlikely(!nr_exclusive)) | |
7d478721 | 5780 | wake_flags = 0; |
1da177e4 LT |
5781 | |
5782 | spin_lock_irqsave(&q->lock, flags); | |
7d478721 | 5783 | __wake_up_common(q, mode, nr_exclusive, wake_flags, key); |
1da177e4 LT |
5784 | spin_unlock_irqrestore(&q->lock, flags); |
5785 | } | |
4ede816a DL |
5786 | EXPORT_SYMBOL_GPL(__wake_up_sync_key); |
5787 | ||
5788 | /* | |
5789 | * __wake_up_sync - see __wake_up_sync_key() | |
5790 | */ | |
5791 | void __wake_up_sync(wait_queue_head_t *q, unsigned int mode, int nr_exclusive) | |
5792 | { | |
5793 | __wake_up_sync_key(q, mode, nr_exclusive, NULL); | |
5794 | } | |
1da177e4 LT |
5795 | EXPORT_SYMBOL_GPL(__wake_up_sync); /* For internal use only */ |
5796 | ||
65eb3dc6 KD |
5797 | /** |
5798 | * complete: - signals a single thread waiting on this completion | |
5799 | * @x: holds the state of this particular completion | |
5800 | * | |
5801 | * This will wake up a single thread waiting on this completion. Threads will be | |
5802 | * awakened in the same order in which they were queued. | |
5803 | * | |
5804 | * See also complete_all(), wait_for_completion() and related routines. | |
50fa610a DH |
5805 | * |
5806 | * It may be assumed that this function implies a write memory barrier before | |
5807 | * changing the task state if and only if any tasks are woken up. | |
65eb3dc6 | 5808 | */ |
b15136e9 | 5809 | void complete(struct completion *x) |
1da177e4 LT |
5810 | { |
5811 | unsigned long flags; | |
5812 | ||
5813 | spin_lock_irqsave(&x->wait.lock, flags); | |
5814 | x->done++; | |
d9514f6c | 5815 | __wake_up_common(&x->wait, TASK_NORMAL, 1, 0, NULL); |
1da177e4 LT |
5816 | spin_unlock_irqrestore(&x->wait.lock, flags); |
5817 | } | |
5818 | EXPORT_SYMBOL(complete); | |
5819 | ||
65eb3dc6 KD |
5820 | /** |
5821 | * complete_all: - signals all threads waiting on this completion | |
5822 | * @x: holds the state of this particular completion | |
5823 | * | |
5824 | * This will wake up all threads waiting on this particular completion event. | |
50fa610a DH |
5825 | * |
5826 | * It may be assumed that this function implies a write memory barrier before | |
5827 | * changing the task state if and only if any tasks are woken up. | |
65eb3dc6 | 5828 | */ |
b15136e9 | 5829 | void complete_all(struct completion *x) |
1da177e4 LT |
5830 | { |
5831 | unsigned long flags; | |
5832 | ||
5833 | spin_lock_irqsave(&x->wait.lock, flags); | |
5834 | x->done += UINT_MAX/2; | |
d9514f6c | 5835 | __wake_up_common(&x->wait, TASK_NORMAL, 0, 0, NULL); |
1da177e4 LT |
5836 | spin_unlock_irqrestore(&x->wait.lock, flags); |
5837 | } | |
5838 | EXPORT_SYMBOL(complete_all); | |
5839 | ||
8cbbe86d AK |
5840 | static inline long __sched |
5841 | do_wait_for_common(struct completion *x, long timeout, int state) | |
1da177e4 | 5842 | { |
1da177e4 LT |
5843 | if (!x->done) { |
5844 | DECLARE_WAITQUEUE(wait, current); | |
5845 | ||
5846 | wait.flags |= WQ_FLAG_EXCLUSIVE; | |
5847 | __add_wait_queue_tail(&x->wait, &wait); | |
5848 | do { | |
94d3d824 | 5849 | if (signal_pending_state(state, current)) { |
ea71a546 ON |
5850 | timeout = -ERESTARTSYS; |
5851 | break; | |
8cbbe86d AK |
5852 | } |
5853 | __set_current_state(state); | |
1da177e4 LT |
5854 | spin_unlock_irq(&x->wait.lock); |
5855 | timeout = schedule_timeout(timeout); | |
5856 | spin_lock_irq(&x->wait.lock); | |
ea71a546 | 5857 | } while (!x->done && timeout); |
1da177e4 | 5858 | __remove_wait_queue(&x->wait, &wait); |
ea71a546 ON |
5859 | if (!x->done) |
5860 | return timeout; | |
1da177e4 LT |
5861 | } |
5862 | x->done--; | |
ea71a546 | 5863 | return timeout ?: 1; |
1da177e4 | 5864 | } |
1da177e4 | 5865 | |
8cbbe86d AK |
5866 | static long __sched |
5867 | wait_for_common(struct completion *x, long timeout, int state) | |
1da177e4 | 5868 | { |
1da177e4 LT |
5869 | might_sleep(); |
5870 | ||
5871 | spin_lock_irq(&x->wait.lock); | |
8cbbe86d | 5872 | timeout = do_wait_for_common(x, timeout, state); |
1da177e4 | 5873 | spin_unlock_irq(&x->wait.lock); |
8cbbe86d AK |
5874 | return timeout; |
5875 | } | |
1da177e4 | 5876 | |
65eb3dc6 KD |
5877 | /** |
5878 | * wait_for_completion: - waits for completion of a task | |
5879 | * @x: holds the state of this particular completion | |
5880 | * | |
5881 | * This waits to be signaled for completion of a specific task. It is NOT | |
5882 | * interruptible and there is no timeout. | |
5883 | * | |
5884 | * See also similar routines (i.e. wait_for_completion_timeout()) with timeout | |
5885 | * and interrupt capability. Also see complete(). | |
5886 | */ | |
b15136e9 | 5887 | void __sched wait_for_completion(struct completion *x) |
8cbbe86d AK |
5888 | { |
5889 | wait_for_common(x, MAX_SCHEDULE_TIMEOUT, TASK_UNINTERRUPTIBLE); | |
1da177e4 | 5890 | } |
8cbbe86d | 5891 | EXPORT_SYMBOL(wait_for_completion); |
1da177e4 | 5892 | |
65eb3dc6 KD |
5893 | /** |
5894 | * wait_for_completion_timeout: - waits for completion of a task (w/timeout) | |
5895 | * @x: holds the state of this particular completion | |
5896 | * @timeout: timeout value in jiffies | |
5897 | * | |
5898 | * This waits for either a completion of a specific task to be signaled or for a | |
5899 | * specified timeout to expire. The timeout is in jiffies. It is not | |
5900 | * interruptible. | |
5901 | */ | |
b15136e9 | 5902 | unsigned long __sched |
8cbbe86d | 5903 | wait_for_completion_timeout(struct completion *x, unsigned long timeout) |
1da177e4 | 5904 | { |
8cbbe86d | 5905 | return wait_for_common(x, timeout, TASK_UNINTERRUPTIBLE); |
1da177e4 | 5906 | } |
8cbbe86d | 5907 | EXPORT_SYMBOL(wait_for_completion_timeout); |
1da177e4 | 5908 | |
65eb3dc6 KD |
5909 | /** |
5910 | * wait_for_completion_interruptible: - waits for completion of a task (w/intr) | |
5911 | * @x: holds the state of this particular completion | |
5912 | * | |
5913 | * This waits for completion of a specific task to be signaled. It is | |
5914 | * interruptible. | |
5915 | */ | |
8cbbe86d | 5916 | int __sched wait_for_completion_interruptible(struct completion *x) |
0fec171c | 5917 | { |
51e97990 AK |
5918 | long t = wait_for_common(x, MAX_SCHEDULE_TIMEOUT, TASK_INTERRUPTIBLE); |
5919 | if (t == -ERESTARTSYS) | |
5920 | return t; | |
5921 | return 0; | |
0fec171c | 5922 | } |
8cbbe86d | 5923 | EXPORT_SYMBOL(wait_for_completion_interruptible); |
1da177e4 | 5924 | |
65eb3dc6 KD |
5925 | /** |
5926 | * wait_for_completion_interruptible_timeout: - waits for completion (w/(to,intr)) | |
5927 | * @x: holds the state of this particular completion | |
5928 | * @timeout: timeout value in jiffies | |
5929 | * | |
5930 | * This waits for either a completion of a specific task to be signaled or for a | |
5931 | * specified timeout to expire. It is interruptible. The timeout is in jiffies. | |
5932 | */ | |
b15136e9 | 5933 | unsigned long __sched |
8cbbe86d AK |
5934 | wait_for_completion_interruptible_timeout(struct completion *x, |
5935 | unsigned long timeout) | |
0fec171c | 5936 | { |
8cbbe86d | 5937 | return wait_for_common(x, timeout, TASK_INTERRUPTIBLE); |
0fec171c | 5938 | } |
8cbbe86d | 5939 | EXPORT_SYMBOL(wait_for_completion_interruptible_timeout); |
1da177e4 | 5940 | |
65eb3dc6 KD |
5941 | /** |
5942 | * wait_for_completion_killable: - waits for completion of a task (killable) | |
5943 | * @x: holds the state of this particular completion | |
5944 | * | |
5945 | * This waits to be signaled for completion of a specific task. It can be | |
5946 | * interrupted by a kill signal. | |
5947 | */ | |
009e577e MW |
5948 | int __sched wait_for_completion_killable(struct completion *x) |
5949 | { | |
5950 | long t = wait_for_common(x, MAX_SCHEDULE_TIMEOUT, TASK_KILLABLE); | |
5951 | if (t == -ERESTARTSYS) | |
5952 | return t; | |
5953 | return 0; | |
5954 | } | |
5955 | EXPORT_SYMBOL(wait_for_completion_killable); | |
5956 | ||
be4de352 DC |
5957 | /** |
5958 | * try_wait_for_completion - try to decrement a completion without blocking | |
5959 | * @x: completion structure | |
5960 | * | |
5961 | * Returns: 0 if a decrement cannot be done without blocking | |
5962 | * 1 if a decrement succeeded. | |
5963 | * | |
5964 | * If a completion is being used as a counting completion, | |
5965 | * attempt to decrement the counter without blocking. This | |
5966 | * enables us to avoid waiting if the resource the completion | |
5967 | * is protecting is not available. | |
5968 | */ | |
5969 | bool try_wait_for_completion(struct completion *x) | |
5970 | { | |
7539a3b3 | 5971 | unsigned long flags; |
be4de352 DC |
5972 | int ret = 1; |
5973 | ||
7539a3b3 | 5974 | spin_lock_irqsave(&x->wait.lock, flags); |
be4de352 DC |
5975 | if (!x->done) |
5976 | ret = 0; | |
5977 | else | |
5978 | x->done--; | |
7539a3b3 | 5979 | spin_unlock_irqrestore(&x->wait.lock, flags); |
be4de352 DC |
5980 | return ret; |
5981 | } | |
5982 | EXPORT_SYMBOL(try_wait_for_completion); | |
5983 | ||
5984 | /** | |
5985 | * completion_done - Test to see if a completion has any waiters | |
5986 | * @x: completion structure | |
5987 | * | |
5988 | * Returns: 0 if there are waiters (wait_for_completion() in progress) | |
5989 | * 1 if there are no waiters. | |
5990 | * | |
5991 | */ | |
5992 | bool completion_done(struct completion *x) | |
5993 | { | |
7539a3b3 | 5994 | unsigned long flags; |
be4de352 DC |
5995 | int ret = 1; |
5996 | ||
7539a3b3 | 5997 | spin_lock_irqsave(&x->wait.lock, flags); |
be4de352 DC |
5998 | if (!x->done) |
5999 | ret = 0; | |
7539a3b3 | 6000 | spin_unlock_irqrestore(&x->wait.lock, flags); |
be4de352 DC |
6001 | return ret; |
6002 | } | |
6003 | EXPORT_SYMBOL(completion_done); | |
6004 | ||
8cbbe86d AK |
6005 | static long __sched |
6006 | sleep_on_common(wait_queue_head_t *q, int state, long timeout) | |
1da177e4 | 6007 | { |
0fec171c IM |
6008 | unsigned long flags; |
6009 | wait_queue_t wait; | |
6010 | ||
6011 | init_waitqueue_entry(&wait, current); | |
1da177e4 | 6012 | |
8cbbe86d | 6013 | __set_current_state(state); |
1da177e4 | 6014 | |
8cbbe86d AK |
6015 | spin_lock_irqsave(&q->lock, flags); |
6016 | __add_wait_queue(q, &wait); | |
6017 | spin_unlock(&q->lock); | |
6018 | timeout = schedule_timeout(timeout); | |
6019 | spin_lock_irq(&q->lock); | |
6020 | __remove_wait_queue(q, &wait); | |
6021 | spin_unlock_irqrestore(&q->lock, flags); | |
6022 | ||
6023 | return timeout; | |
6024 | } | |
6025 | ||
6026 | void __sched interruptible_sleep_on(wait_queue_head_t *q) | |
6027 | { | |
6028 | sleep_on_common(q, TASK_INTERRUPTIBLE, MAX_SCHEDULE_TIMEOUT); | |
1da177e4 | 6029 | } |
1da177e4 LT |
6030 | EXPORT_SYMBOL(interruptible_sleep_on); |
6031 | ||
0fec171c | 6032 | long __sched |
95cdf3b7 | 6033 | interruptible_sleep_on_timeout(wait_queue_head_t *q, long timeout) |
1da177e4 | 6034 | { |
8cbbe86d | 6035 | return sleep_on_common(q, TASK_INTERRUPTIBLE, timeout); |
1da177e4 | 6036 | } |
1da177e4 LT |
6037 | EXPORT_SYMBOL(interruptible_sleep_on_timeout); |
6038 | ||
0fec171c | 6039 | void __sched sleep_on(wait_queue_head_t *q) |
1da177e4 | 6040 | { |
8cbbe86d | 6041 | sleep_on_common(q, TASK_UNINTERRUPTIBLE, MAX_SCHEDULE_TIMEOUT); |
1da177e4 | 6042 | } |
1da177e4 LT |
6043 | EXPORT_SYMBOL(sleep_on); |
6044 | ||
0fec171c | 6045 | long __sched sleep_on_timeout(wait_queue_head_t *q, long timeout) |
1da177e4 | 6046 | { |
8cbbe86d | 6047 | return sleep_on_common(q, TASK_UNINTERRUPTIBLE, timeout); |
1da177e4 | 6048 | } |
1da177e4 LT |
6049 | EXPORT_SYMBOL(sleep_on_timeout); |
6050 | ||
b29739f9 IM |
6051 | #ifdef CONFIG_RT_MUTEXES |
6052 | ||
6053 | /* | |
6054 | * rt_mutex_setprio - set the current priority of a task | |
6055 | * @p: task | |
6056 | * @prio: prio value (kernel-internal form) | |
6057 | * | |
6058 | * This function changes the 'effective' priority of a task. It does | |
6059 | * not touch ->normal_prio like __setscheduler(). | |
6060 | * | |
6061 | * Used by the rt_mutex code to implement priority inheritance logic. | |
6062 | */ | |
36c8b586 | 6063 | void rt_mutex_setprio(struct task_struct *p, int prio) |
b29739f9 IM |
6064 | { |
6065 | unsigned long flags; | |
83b699ed | 6066 | int oldprio, on_rq, running; |
70b97a7f | 6067 | struct rq *rq; |
cb469845 | 6068 | const struct sched_class *prev_class = p->sched_class; |
b29739f9 IM |
6069 | |
6070 | BUG_ON(prio < 0 || prio > MAX_PRIO); | |
6071 | ||
6072 | rq = task_rq_lock(p, &flags); | |
a8e504d2 | 6073 | update_rq_clock(rq); |
b29739f9 | 6074 | |
d5f9f942 | 6075 | oldprio = p->prio; |
dd41f596 | 6076 | on_rq = p->se.on_rq; |
051a1d1a | 6077 | running = task_current(rq, p); |
0e1f3483 | 6078 | if (on_rq) |
69be72c1 | 6079 | dequeue_task(rq, p, 0); |
0e1f3483 HS |
6080 | if (running) |
6081 | p->sched_class->put_prev_task(rq, p); | |
dd41f596 IM |
6082 | |
6083 | if (rt_prio(prio)) | |
6084 | p->sched_class = &rt_sched_class; | |
6085 | else | |
6086 | p->sched_class = &fair_sched_class; | |
6087 | ||
b29739f9 IM |
6088 | p->prio = prio; |
6089 | ||
0e1f3483 HS |
6090 | if (running) |
6091 | p->sched_class->set_curr_task(rq); | |
dd41f596 | 6092 | if (on_rq) { |
8159f87e | 6093 | enqueue_task(rq, p, 0); |
cb469845 SR |
6094 | |
6095 | check_class_changed(rq, p, prev_class, oldprio, running); | |
b29739f9 IM |
6096 | } |
6097 | task_rq_unlock(rq, &flags); | |
6098 | } | |
6099 | ||
6100 | #endif | |
6101 | ||
36c8b586 | 6102 | void set_user_nice(struct task_struct *p, long nice) |
1da177e4 | 6103 | { |
dd41f596 | 6104 | int old_prio, delta, on_rq; |
1da177e4 | 6105 | unsigned long flags; |
70b97a7f | 6106 | struct rq *rq; |
1da177e4 LT |
6107 | |
6108 | if (TASK_NICE(p) == nice || nice < -20 || nice > 19) | |
6109 | return; | |
6110 | /* | |
6111 | * We have to be careful, if called from sys_setpriority(), | |
6112 | * the task might be in the middle of scheduling on another CPU. | |
6113 | */ | |
6114 | rq = task_rq_lock(p, &flags); | |
a8e504d2 | 6115 | update_rq_clock(rq); |
1da177e4 LT |
6116 | /* |
6117 | * The RT priorities are set via sched_setscheduler(), but we still | |
6118 | * allow the 'normal' nice value to be set - but as expected | |
6119 | * it wont have any effect on scheduling until the task is | |
dd41f596 | 6120 | * SCHED_FIFO/SCHED_RR: |
1da177e4 | 6121 | */ |
e05606d3 | 6122 | if (task_has_rt_policy(p)) { |
1da177e4 LT |
6123 | p->static_prio = NICE_TO_PRIO(nice); |
6124 | goto out_unlock; | |
6125 | } | |
dd41f596 | 6126 | on_rq = p->se.on_rq; |
c09595f6 | 6127 | if (on_rq) |
69be72c1 | 6128 | dequeue_task(rq, p, 0); |
1da177e4 | 6129 | |
1da177e4 | 6130 | p->static_prio = NICE_TO_PRIO(nice); |
2dd73a4f | 6131 | set_load_weight(p); |
b29739f9 IM |
6132 | old_prio = p->prio; |
6133 | p->prio = effective_prio(p); | |
6134 | delta = p->prio - old_prio; | |
1da177e4 | 6135 | |
dd41f596 | 6136 | if (on_rq) { |
8159f87e | 6137 | enqueue_task(rq, p, 0); |
1da177e4 | 6138 | /* |
d5f9f942 AM |
6139 | * If the task increased its priority or is running and |
6140 | * lowered its priority, then reschedule its CPU: | |
1da177e4 | 6141 | */ |
d5f9f942 | 6142 | if (delta < 0 || (delta > 0 && task_running(rq, p))) |
1da177e4 LT |
6143 | resched_task(rq->curr); |
6144 | } | |
6145 | out_unlock: | |
6146 | task_rq_unlock(rq, &flags); | |
6147 | } | |
1da177e4 LT |
6148 | EXPORT_SYMBOL(set_user_nice); |
6149 | ||
e43379f1 MM |
6150 | /* |
6151 | * can_nice - check if a task can reduce its nice value | |
6152 | * @p: task | |
6153 | * @nice: nice value | |
6154 | */ | |
36c8b586 | 6155 | int can_nice(const struct task_struct *p, const int nice) |
e43379f1 | 6156 | { |
024f4747 MM |
6157 | /* convert nice value [19,-20] to rlimit style value [1,40] */ |
6158 | int nice_rlim = 20 - nice; | |
48f24c4d | 6159 | |
e43379f1 MM |
6160 | return (nice_rlim <= p->signal->rlim[RLIMIT_NICE].rlim_cur || |
6161 | capable(CAP_SYS_NICE)); | |
6162 | } | |
6163 | ||
1da177e4 LT |
6164 | #ifdef __ARCH_WANT_SYS_NICE |
6165 | ||
6166 | /* | |
6167 | * sys_nice - change the priority of the current process. | |
6168 | * @increment: priority increment | |
6169 | * | |
6170 | * sys_setpriority is a more generic, but much slower function that | |
6171 | * does similar things. | |
6172 | */ | |
5add95d4 | 6173 | SYSCALL_DEFINE1(nice, int, increment) |
1da177e4 | 6174 | { |
48f24c4d | 6175 | long nice, retval; |
1da177e4 LT |
6176 | |
6177 | /* | |
6178 | * Setpriority might change our priority at the same moment. | |
6179 | * We don't have to worry. Conceptually one call occurs first | |
6180 | * and we have a single winner. | |
6181 | */ | |
e43379f1 MM |
6182 | if (increment < -40) |
6183 | increment = -40; | |
1da177e4 LT |
6184 | if (increment > 40) |
6185 | increment = 40; | |
6186 | ||
2b8f836f | 6187 | nice = TASK_NICE(current) + increment; |
1da177e4 LT |
6188 | if (nice < -20) |
6189 | nice = -20; | |
6190 | if (nice > 19) | |
6191 | nice = 19; | |
6192 | ||
e43379f1 MM |
6193 | if (increment < 0 && !can_nice(current, nice)) |
6194 | return -EPERM; | |
6195 | ||
1da177e4 LT |
6196 | retval = security_task_setnice(current, nice); |
6197 | if (retval) | |
6198 | return retval; | |
6199 | ||
6200 | set_user_nice(current, nice); | |
6201 | return 0; | |
6202 | } | |
6203 | ||
6204 | #endif | |
6205 | ||
6206 | /** | |
6207 | * task_prio - return the priority value of a given task. | |
6208 | * @p: the task in question. | |
6209 | * | |
6210 | * This is the priority value as seen by users in /proc. | |
6211 | * RT tasks are offset by -200. Normal tasks are centered | |
6212 | * around 0, value goes from -16 to +15. | |
6213 | */ | |
36c8b586 | 6214 | int task_prio(const struct task_struct *p) |
1da177e4 LT |
6215 | { |
6216 | return p->prio - MAX_RT_PRIO; | |
6217 | } | |
6218 | ||
6219 | /** | |
6220 | * task_nice - return the nice value of a given task. | |
6221 | * @p: the task in question. | |
6222 | */ | |
36c8b586 | 6223 | int task_nice(const struct task_struct *p) |
1da177e4 LT |
6224 | { |
6225 | return TASK_NICE(p); | |
6226 | } | |
150d8bed | 6227 | EXPORT_SYMBOL(task_nice); |
1da177e4 LT |
6228 | |
6229 | /** | |
6230 | * idle_cpu - is a given cpu idle currently? | |
6231 | * @cpu: the processor in question. | |
6232 | */ | |
6233 | int idle_cpu(int cpu) | |
6234 | { | |
6235 | return cpu_curr(cpu) == cpu_rq(cpu)->idle; | |
6236 | } | |
6237 | ||
1da177e4 LT |
6238 | /** |
6239 | * idle_task - return the idle task for a given cpu. | |
6240 | * @cpu: the processor in question. | |
6241 | */ | |
36c8b586 | 6242 | struct task_struct *idle_task(int cpu) |
1da177e4 LT |
6243 | { |
6244 | return cpu_rq(cpu)->idle; | |
6245 | } | |
6246 | ||
6247 | /** | |
6248 | * find_process_by_pid - find a process with a matching PID value. | |
6249 | * @pid: the pid in question. | |
6250 | */ | |
a9957449 | 6251 | static struct task_struct *find_process_by_pid(pid_t pid) |
1da177e4 | 6252 | { |
228ebcbe | 6253 | return pid ? find_task_by_vpid(pid) : current; |
1da177e4 LT |
6254 | } |
6255 | ||
6256 | /* Actually do priority change: must hold rq lock. */ | |
dd41f596 IM |
6257 | static void |
6258 | __setscheduler(struct rq *rq, struct task_struct *p, int policy, int prio) | |
1da177e4 | 6259 | { |
dd41f596 | 6260 | BUG_ON(p->se.on_rq); |
48f24c4d | 6261 | |
1da177e4 LT |
6262 | p->policy = policy; |
6263 | p->rt_priority = prio; | |
b29739f9 IM |
6264 | p->normal_prio = normal_prio(p); |
6265 | /* we are holding p->pi_lock already */ | |
6266 | p->prio = rt_mutex_getprio(p); | |
ffd44db5 PZ |
6267 | if (rt_prio(p->prio)) |
6268 | p->sched_class = &rt_sched_class; | |
6269 | else | |
6270 | p->sched_class = &fair_sched_class; | |
2dd73a4f | 6271 | set_load_weight(p); |
1da177e4 LT |
6272 | } |
6273 | ||
c69e8d9c DH |
6274 | /* |
6275 | * check the target process has a UID that matches the current process's | |
6276 | */ | |
6277 | static bool check_same_owner(struct task_struct *p) | |
6278 | { | |
6279 | const struct cred *cred = current_cred(), *pcred; | |
6280 | bool match; | |
6281 | ||
6282 | rcu_read_lock(); | |
6283 | pcred = __task_cred(p); | |
6284 | match = (cred->euid == pcred->euid || | |
6285 | cred->euid == pcred->uid); | |
6286 | rcu_read_unlock(); | |
6287 | return match; | |
6288 | } | |
6289 | ||
961ccddd RR |
6290 | static int __sched_setscheduler(struct task_struct *p, int policy, |
6291 | struct sched_param *param, bool user) | |
1da177e4 | 6292 | { |
83b699ed | 6293 | int retval, oldprio, oldpolicy = -1, on_rq, running; |
1da177e4 | 6294 | unsigned long flags; |
cb469845 | 6295 | const struct sched_class *prev_class = p->sched_class; |
70b97a7f | 6296 | struct rq *rq; |
ca94c442 | 6297 | int reset_on_fork; |
1da177e4 | 6298 | |
66e5393a SR |
6299 | /* may grab non-irq protected spin_locks */ |
6300 | BUG_ON(in_interrupt()); | |
1da177e4 LT |
6301 | recheck: |
6302 | /* double check policy once rq lock held */ | |
ca94c442 LP |
6303 | if (policy < 0) { |
6304 | reset_on_fork = p->sched_reset_on_fork; | |
1da177e4 | 6305 | policy = oldpolicy = p->policy; |
ca94c442 LP |
6306 | } else { |
6307 | reset_on_fork = !!(policy & SCHED_RESET_ON_FORK); | |
6308 | policy &= ~SCHED_RESET_ON_FORK; | |
6309 | ||
6310 | if (policy != SCHED_FIFO && policy != SCHED_RR && | |
6311 | policy != SCHED_NORMAL && policy != SCHED_BATCH && | |
6312 | policy != SCHED_IDLE) | |
6313 | return -EINVAL; | |
6314 | } | |
6315 | ||
1da177e4 LT |
6316 | /* |
6317 | * Valid priorities for SCHED_FIFO and SCHED_RR are | |
dd41f596 IM |
6318 | * 1..MAX_USER_RT_PRIO-1, valid priority for SCHED_NORMAL, |
6319 | * SCHED_BATCH and SCHED_IDLE is 0. | |
1da177e4 LT |
6320 | */ |
6321 | if (param->sched_priority < 0 || | |
95cdf3b7 | 6322 | (p->mm && param->sched_priority > MAX_USER_RT_PRIO-1) || |
d46523ea | 6323 | (!p->mm && param->sched_priority > MAX_RT_PRIO-1)) |
1da177e4 | 6324 | return -EINVAL; |
e05606d3 | 6325 | if (rt_policy(policy) != (param->sched_priority != 0)) |
1da177e4 LT |
6326 | return -EINVAL; |
6327 | ||
37e4ab3f OC |
6328 | /* |
6329 | * Allow unprivileged RT tasks to decrease priority: | |
6330 | */ | |
961ccddd | 6331 | if (user && !capable(CAP_SYS_NICE)) { |
e05606d3 | 6332 | if (rt_policy(policy)) { |
8dc3e909 | 6333 | unsigned long rlim_rtprio; |
8dc3e909 ON |
6334 | |
6335 | if (!lock_task_sighand(p, &flags)) | |
6336 | return -ESRCH; | |
6337 | rlim_rtprio = p->signal->rlim[RLIMIT_RTPRIO].rlim_cur; | |
6338 | unlock_task_sighand(p, &flags); | |
6339 | ||
6340 | /* can't set/change the rt policy */ | |
6341 | if (policy != p->policy && !rlim_rtprio) | |
6342 | return -EPERM; | |
6343 | ||
6344 | /* can't increase priority */ | |
6345 | if (param->sched_priority > p->rt_priority && | |
6346 | param->sched_priority > rlim_rtprio) | |
6347 | return -EPERM; | |
6348 | } | |
dd41f596 IM |
6349 | /* |
6350 | * Like positive nice levels, dont allow tasks to | |
6351 | * move out of SCHED_IDLE either: | |
6352 | */ | |
6353 | if (p->policy == SCHED_IDLE && policy != SCHED_IDLE) | |
6354 | return -EPERM; | |
5fe1d75f | 6355 | |
37e4ab3f | 6356 | /* can't change other user's priorities */ |
c69e8d9c | 6357 | if (!check_same_owner(p)) |
37e4ab3f | 6358 | return -EPERM; |
ca94c442 LP |
6359 | |
6360 | /* Normal users shall not reset the sched_reset_on_fork flag */ | |
6361 | if (p->sched_reset_on_fork && !reset_on_fork) | |
6362 | return -EPERM; | |
37e4ab3f | 6363 | } |
1da177e4 | 6364 | |
725aad24 | 6365 | if (user) { |
b68aa230 | 6366 | #ifdef CONFIG_RT_GROUP_SCHED |
725aad24 JF |
6367 | /* |
6368 | * Do not allow realtime tasks into groups that have no runtime | |
6369 | * assigned. | |
6370 | */ | |
9a7e0b18 PZ |
6371 | if (rt_bandwidth_enabled() && rt_policy(policy) && |
6372 | task_group(p)->rt_bandwidth.rt_runtime == 0) | |
725aad24 | 6373 | return -EPERM; |
b68aa230 PZ |
6374 | #endif |
6375 | ||
725aad24 JF |
6376 | retval = security_task_setscheduler(p, policy, param); |
6377 | if (retval) | |
6378 | return retval; | |
6379 | } | |
6380 | ||
b29739f9 IM |
6381 | /* |
6382 | * make sure no PI-waiters arrive (or leave) while we are | |
6383 | * changing the priority of the task: | |
6384 | */ | |
1d615482 | 6385 | raw_spin_lock_irqsave(&p->pi_lock, flags); |
1da177e4 LT |
6386 | /* |
6387 | * To be able to change p->policy safely, the apropriate | |
6388 | * runqueue lock must be held. | |
6389 | */ | |
b29739f9 | 6390 | rq = __task_rq_lock(p); |
1da177e4 LT |
6391 | /* recheck policy now with rq lock held */ |
6392 | if (unlikely(oldpolicy != -1 && oldpolicy != p->policy)) { | |
6393 | policy = oldpolicy = -1; | |
b29739f9 | 6394 | __task_rq_unlock(rq); |
1d615482 | 6395 | raw_spin_unlock_irqrestore(&p->pi_lock, flags); |
1da177e4 LT |
6396 | goto recheck; |
6397 | } | |
2daa3577 | 6398 | update_rq_clock(rq); |
dd41f596 | 6399 | on_rq = p->se.on_rq; |
051a1d1a | 6400 | running = task_current(rq, p); |
0e1f3483 | 6401 | if (on_rq) |
2e1cb74a | 6402 | deactivate_task(rq, p, 0); |
0e1f3483 HS |
6403 | if (running) |
6404 | p->sched_class->put_prev_task(rq, p); | |
f6b53205 | 6405 | |
ca94c442 LP |
6406 | p->sched_reset_on_fork = reset_on_fork; |
6407 | ||
1da177e4 | 6408 | oldprio = p->prio; |
dd41f596 | 6409 | __setscheduler(rq, p, policy, param->sched_priority); |
f6b53205 | 6410 | |
0e1f3483 HS |
6411 | if (running) |
6412 | p->sched_class->set_curr_task(rq); | |
dd41f596 IM |
6413 | if (on_rq) { |
6414 | activate_task(rq, p, 0); | |
cb469845 SR |
6415 | |
6416 | check_class_changed(rq, p, prev_class, oldprio, running); | |
1da177e4 | 6417 | } |
b29739f9 | 6418 | __task_rq_unlock(rq); |
1d615482 | 6419 | raw_spin_unlock_irqrestore(&p->pi_lock, flags); |
b29739f9 | 6420 | |
95e02ca9 TG |
6421 | rt_mutex_adjust_pi(p); |
6422 | ||
1da177e4 LT |
6423 | return 0; |
6424 | } | |
961ccddd RR |
6425 | |
6426 | /** | |
6427 | * sched_setscheduler - change the scheduling policy and/or RT priority of a thread. | |
6428 | * @p: the task in question. | |
6429 | * @policy: new policy. | |
6430 | * @param: structure containing the new RT priority. | |
6431 | * | |
6432 | * NOTE that the task may be already dead. | |
6433 | */ | |
6434 | int sched_setscheduler(struct task_struct *p, int policy, | |
6435 | struct sched_param *param) | |
6436 | { | |
6437 | return __sched_setscheduler(p, policy, param, true); | |
6438 | } | |
1da177e4 LT |
6439 | EXPORT_SYMBOL_GPL(sched_setscheduler); |
6440 | ||
961ccddd RR |
6441 | /** |
6442 | * sched_setscheduler_nocheck - change the scheduling policy and/or RT priority of a thread from kernelspace. | |
6443 | * @p: the task in question. | |
6444 | * @policy: new policy. | |
6445 | * @param: structure containing the new RT priority. | |
6446 | * | |
6447 | * Just like sched_setscheduler, only don't bother checking if the | |
6448 | * current context has permission. For example, this is needed in | |
6449 | * stop_machine(): we create temporary high priority worker threads, | |
6450 | * but our caller might not have that capability. | |
6451 | */ | |
6452 | int sched_setscheduler_nocheck(struct task_struct *p, int policy, | |
6453 | struct sched_param *param) | |
6454 | { | |
6455 | return __sched_setscheduler(p, policy, param, false); | |
6456 | } | |
6457 | ||
95cdf3b7 IM |
6458 | static int |
6459 | do_sched_setscheduler(pid_t pid, int policy, struct sched_param __user *param) | |
1da177e4 | 6460 | { |
1da177e4 LT |
6461 | struct sched_param lparam; |
6462 | struct task_struct *p; | |
36c8b586 | 6463 | int retval; |
1da177e4 LT |
6464 | |
6465 | if (!param || pid < 0) | |
6466 | return -EINVAL; | |
6467 | if (copy_from_user(&lparam, param, sizeof(struct sched_param))) | |
6468 | return -EFAULT; | |
5fe1d75f ON |
6469 | |
6470 | rcu_read_lock(); | |
6471 | retval = -ESRCH; | |
1da177e4 | 6472 | p = find_process_by_pid(pid); |
5fe1d75f ON |
6473 | if (p != NULL) |
6474 | retval = sched_setscheduler(p, policy, &lparam); | |
6475 | rcu_read_unlock(); | |
36c8b586 | 6476 | |
1da177e4 LT |
6477 | return retval; |
6478 | } | |
6479 | ||
6480 | /** | |
6481 | * sys_sched_setscheduler - set/change the scheduler policy and RT priority | |
6482 | * @pid: the pid in question. | |
6483 | * @policy: new policy. | |
6484 | * @param: structure containing the new RT priority. | |
6485 | */ | |
5add95d4 HC |
6486 | SYSCALL_DEFINE3(sched_setscheduler, pid_t, pid, int, policy, |
6487 | struct sched_param __user *, param) | |
1da177e4 | 6488 | { |
c21761f1 JB |
6489 | /* negative values for policy are not valid */ |
6490 | if (policy < 0) | |
6491 | return -EINVAL; | |
6492 | ||
1da177e4 LT |
6493 | return do_sched_setscheduler(pid, policy, param); |
6494 | } | |
6495 | ||
6496 | /** | |
6497 | * sys_sched_setparam - set/change the RT priority of a thread | |
6498 | * @pid: the pid in question. | |
6499 | * @param: structure containing the new RT priority. | |
6500 | */ | |
5add95d4 | 6501 | SYSCALL_DEFINE2(sched_setparam, pid_t, pid, struct sched_param __user *, param) |
1da177e4 LT |
6502 | { |
6503 | return do_sched_setscheduler(pid, -1, param); | |
6504 | } | |
6505 | ||
6506 | /** | |
6507 | * sys_sched_getscheduler - get the policy (scheduling class) of a thread | |
6508 | * @pid: the pid in question. | |
6509 | */ | |
5add95d4 | 6510 | SYSCALL_DEFINE1(sched_getscheduler, pid_t, pid) |
1da177e4 | 6511 | { |
36c8b586 | 6512 | struct task_struct *p; |
3a5c359a | 6513 | int retval; |
1da177e4 LT |
6514 | |
6515 | if (pid < 0) | |
3a5c359a | 6516 | return -EINVAL; |
1da177e4 LT |
6517 | |
6518 | retval = -ESRCH; | |
5fe85be0 | 6519 | rcu_read_lock(); |
1da177e4 LT |
6520 | p = find_process_by_pid(pid); |
6521 | if (p) { | |
6522 | retval = security_task_getscheduler(p); | |
6523 | if (!retval) | |
ca94c442 LP |
6524 | retval = p->policy |
6525 | | (p->sched_reset_on_fork ? SCHED_RESET_ON_FORK : 0); | |
1da177e4 | 6526 | } |
5fe85be0 | 6527 | rcu_read_unlock(); |
1da177e4 LT |
6528 | return retval; |
6529 | } | |
6530 | ||
6531 | /** | |
ca94c442 | 6532 | * sys_sched_getparam - get the RT priority of a thread |
1da177e4 LT |
6533 | * @pid: the pid in question. |
6534 | * @param: structure containing the RT priority. | |
6535 | */ | |
5add95d4 | 6536 | SYSCALL_DEFINE2(sched_getparam, pid_t, pid, struct sched_param __user *, param) |
1da177e4 LT |
6537 | { |
6538 | struct sched_param lp; | |
36c8b586 | 6539 | struct task_struct *p; |
3a5c359a | 6540 | int retval; |
1da177e4 LT |
6541 | |
6542 | if (!param || pid < 0) | |
3a5c359a | 6543 | return -EINVAL; |
1da177e4 | 6544 | |
5fe85be0 | 6545 | rcu_read_lock(); |
1da177e4 LT |
6546 | p = find_process_by_pid(pid); |
6547 | retval = -ESRCH; | |
6548 | if (!p) | |
6549 | goto out_unlock; | |
6550 | ||
6551 | retval = security_task_getscheduler(p); | |
6552 | if (retval) | |
6553 | goto out_unlock; | |
6554 | ||
6555 | lp.sched_priority = p->rt_priority; | |
5fe85be0 | 6556 | rcu_read_unlock(); |
1da177e4 LT |
6557 | |
6558 | /* | |
6559 | * This one might sleep, we cannot do it with a spinlock held ... | |
6560 | */ | |
6561 | retval = copy_to_user(param, &lp, sizeof(*param)) ? -EFAULT : 0; | |
6562 | ||
1da177e4 LT |
6563 | return retval; |
6564 | ||
6565 | out_unlock: | |
5fe85be0 | 6566 | rcu_read_unlock(); |
1da177e4 LT |
6567 | return retval; |
6568 | } | |
6569 | ||
96f874e2 | 6570 | long sched_setaffinity(pid_t pid, const struct cpumask *in_mask) |
1da177e4 | 6571 | { |
5a16f3d3 | 6572 | cpumask_var_t cpus_allowed, new_mask; |
36c8b586 IM |
6573 | struct task_struct *p; |
6574 | int retval; | |
1da177e4 | 6575 | |
95402b38 | 6576 | get_online_cpus(); |
23f5d142 | 6577 | rcu_read_lock(); |
1da177e4 LT |
6578 | |
6579 | p = find_process_by_pid(pid); | |
6580 | if (!p) { | |
23f5d142 | 6581 | rcu_read_unlock(); |
95402b38 | 6582 | put_online_cpus(); |
1da177e4 LT |
6583 | return -ESRCH; |
6584 | } | |
6585 | ||
23f5d142 | 6586 | /* Prevent p going away */ |
1da177e4 | 6587 | get_task_struct(p); |
23f5d142 | 6588 | rcu_read_unlock(); |
1da177e4 | 6589 | |
5a16f3d3 RR |
6590 | if (!alloc_cpumask_var(&cpus_allowed, GFP_KERNEL)) { |
6591 | retval = -ENOMEM; | |
6592 | goto out_put_task; | |
6593 | } | |
6594 | if (!alloc_cpumask_var(&new_mask, GFP_KERNEL)) { | |
6595 | retval = -ENOMEM; | |
6596 | goto out_free_cpus_allowed; | |
6597 | } | |
1da177e4 | 6598 | retval = -EPERM; |
c69e8d9c | 6599 | if (!check_same_owner(p) && !capable(CAP_SYS_NICE)) |
1da177e4 LT |
6600 | goto out_unlock; |
6601 | ||
e7834f8f DQ |
6602 | retval = security_task_setscheduler(p, 0, NULL); |
6603 | if (retval) | |
6604 | goto out_unlock; | |
6605 | ||
5a16f3d3 RR |
6606 | cpuset_cpus_allowed(p, cpus_allowed); |
6607 | cpumask_and(new_mask, in_mask, cpus_allowed); | |
8707d8b8 | 6608 | again: |
5a16f3d3 | 6609 | retval = set_cpus_allowed_ptr(p, new_mask); |
1da177e4 | 6610 | |
8707d8b8 | 6611 | if (!retval) { |
5a16f3d3 RR |
6612 | cpuset_cpus_allowed(p, cpus_allowed); |
6613 | if (!cpumask_subset(new_mask, cpus_allowed)) { | |
8707d8b8 PM |
6614 | /* |
6615 | * We must have raced with a concurrent cpuset | |
6616 | * update. Just reset the cpus_allowed to the | |
6617 | * cpuset's cpus_allowed | |
6618 | */ | |
5a16f3d3 | 6619 | cpumask_copy(new_mask, cpus_allowed); |
8707d8b8 PM |
6620 | goto again; |
6621 | } | |
6622 | } | |
1da177e4 | 6623 | out_unlock: |
5a16f3d3 RR |
6624 | free_cpumask_var(new_mask); |
6625 | out_free_cpus_allowed: | |
6626 | free_cpumask_var(cpus_allowed); | |
6627 | out_put_task: | |
1da177e4 | 6628 | put_task_struct(p); |
95402b38 | 6629 | put_online_cpus(); |
1da177e4 LT |
6630 | return retval; |
6631 | } | |
6632 | ||
6633 | static int get_user_cpu_mask(unsigned long __user *user_mask_ptr, unsigned len, | |
96f874e2 | 6634 | struct cpumask *new_mask) |
1da177e4 | 6635 | { |
96f874e2 RR |
6636 | if (len < cpumask_size()) |
6637 | cpumask_clear(new_mask); | |
6638 | else if (len > cpumask_size()) | |
6639 | len = cpumask_size(); | |
6640 | ||
1da177e4 LT |
6641 | return copy_from_user(new_mask, user_mask_ptr, len) ? -EFAULT : 0; |
6642 | } | |
6643 | ||
6644 | /** | |
6645 | * sys_sched_setaffinity - set the cpu affinity of a process | |
6646 | * @pid: pid of the process | |
6647 | * @len: length in bytes of the bitmask pointed to by user_mask_ptr | |
6648 | * @user_mask_ptr: user-space pointer to the new cpu mask | |
6649 | */ | |
5add95d4 HC |
6650 | SYSCALL_DEFINE3(sched_setaffinity, pid_t, pid, unsigned int, len, |
6651 | unsigned long __user *, user_mask_ptr) | |
1da177e4 | 6652 | { |
5a16f3d3 | 6653 | cpumask_var_t new_mask; |
1da177e4 LT |
6654 | int retval; |
6655 | ||
5a16f3d3 RR |
6656 | if (!alloc_cpumask_var(&new_mask, GFP_KERNEL)) |
6657 | return -ENOMEM; | |
1da177e4 | 6658 | |
5a16f3d3 RR |
6659 | retval = get_user_cpu_mask(user_mask_ptr, len, new_mask); |
6660 | if (retval == 0) | |
6661 | retval = sched_setaffinity(pid, new_mask); | |
6662 | free_cpumask_var(new_mask); | |
6663 | return retval; | |
1da177e4 LT |
6664 | } |
6665 | ||
96f874e2 | 6666 | long sched_getaffinity(pid_t pid, struct cpumask *mask) |
1da177e4 | 6667 | { |
36c8b586 | 6668 | struct task_struct *p; |
31605683 TG |
6669 | unsigned long flags; |
6670 | struct rq *rq; | |
1da177e4 | 6671 | int retval; |
1da177e4 | 6672 | |
95402b38 | 6673 | get_online_cpus(); |
23f5d142 | 6674 | rcu_read_lock(); |
1da177e4 LT |
6675 | |
6676 | retval = -ESRCH; | |
6677 | p = find_process_by_pid(pid); | |
6678 | if (!p) | |
6679 | goto out_unlock; | |
6680 | ||
e7834f8f DQ |
6681 | retval = security_task_getscheduler(p); |
6682 | if (retval) | |
6683 | goto out_unlock; | |
6684 | ||
31605683 | 6685 | rq = task_rq_lock(p, &flags); |
96f874e2 | 6686 | cpumask_and(mask, &p->cpus_allowed, cpu_online_mask); |
31605683 | 6687 | task_rq_unlock(rq, &flags); |
1da177e4 LT |
6688 | |
6689 | out_unlock: | |
23f5d142 | 6690 | rcu_read_unlock(); |
95402b38 | 6691 | put_online_cpus(); |
1da177e4 | 6692 | |
9531b62f | 6693 | return retval; |
1da177e4 LT |
6694 | } |
6695 | ||
6696 | /** | |
6697 | * sys_sched_getaffinity - get the cpu affinity of a process | |
6698 | * @pid: pid of the process | |
6699 | * @len: length in bytes of the bitmask pointed to by user_mask_ptr | |
6700 | * @user_mask_ptr: user-space pointer to hold the current cpu mask | |
6701 | */ | |
5add95d4 HC |
6702 | SYSCALL_DEFINE3(sched_getaffinity, pid_t, pid, unsigned int, len, |
6703 | unsigned long __user *, user_mask_ptr) | |
1da177e4 LT |
6704 | { |
6705 | int ret; | |
f17c8607 | 6706 | cpumask_var_t mask; |
1da177e4 | 6707 | |
f17c8607 | 6708 | if (len < cpumask_size()) |
1da177e4 LT |
6709 | return -EINVAL; |
6710 | ||
f17c8607 RR |
6711 | if (!alloc_cpumask_var(&mask, GFP_KERNEL)) |
6712 | return -ENOMEM; | |
1da177e4 | 6713 | |
f17c8607 RR |
6714 | ret = sched_getaffinity(pid, mask); |
6715 | if (ret == 0) { | |
6716 | if (copy_to_user(user_mask_ptr, mask, cpumask_size())) | |
6717 | ret = -EFAULT; | |
6718 | else | |
6719 | ret = cpumask_size(); | |
6720 | } | |
6721 | free_cpumask_var(mask); | |
1da177e4 | 6722 | |
f17c8607 | 6723 | return ret; |
1da177e4 LT |
6724 | } |
6725 | ||
6726 | /** | |
6727 | * sys_sched_yield - yield the current processor to other threads. | |
6728 | * | |
dd41f596 IM |
6729 | * This function yields the current CPU to other tasks. If there are no |
6730 | * other threads running on this CPU then this function will return. | |
1da177e4 | 6731 | */ |
5add95d4 | 6732 | SYSCALL_DEFINE0(sched_yield) |
1da177e4 | 6733 | { |
70b97a7f | 6734 | struct rq *rq = this_rq_lock(); |
1da177e4 | 6735 | |
2d72376b | 6736 | schedstat_inc(rq, yld_count); |
4530d7ab | 6737 | current->sched_class->yield_task(rq); |
1da177e4 LT |
6738 | |
6739 | /* | |
6740 | * Since we are going to call schedule() anyway, there's | |
6741 | * no need to preempt or enable interrupts: | |
6742 | */ | |
6743 | __release(rq->lock); | |
8a25d5de | 6744 | spin_release(&rq->lock.dep_map, 1, _THIS_IP_); |
9828ea9d | 6745 | do_raw_spin_unlock(&rq->lock); |
1da177e4 LT |
6746 | preempt_enable_no_resched(); |
6747 | ||
6748 | schedule(); | |
6749 | ||
6750 | return 0; | |
6751 | } | |
6752 | ||
d86ee480 PZ |
6753 | static inline int should_resched(void) |
6754 | { | |
6755 | return need_resched() && !(preempt_count() & PREEMPT_ACTIVE); | |
6756 | } | |
6757 | ||
e7b38404 | 6758 | static void __cond_resched(void) |
1da177e4 | 6759 | { |
e7aaaa69 FW |
6760 | add_preempt_count(PREEMPT_ACTIVE); |
6761 | schedule(); | |
6762 | sub_preempt_count(PREEMPT_ACTIVE); | |
1da177e4 LT |
6763 | } |
6764 | ||
02b67cc3 | 6765 | int __sched _cond_resched(void) |
1da177e4 | 6766 | { |
d86ee480 | 6767 | if (should_resched()) { |
1da177e4 LT |
6768 | __cond_resched(); |
6769 | return 1; | |
6770 | } | |
6771 | return 0; | |
6772 | } | |
02b67cc3 | 6773 | EXPORT_SYMBOL(_cond_resched); |
1da177e4 LT |
6774 | |
6775 | /* | |
613afbf8 | 6776 | * __cond_resched_lock() - if a reschedule is pending, drop the given lock, |
1da177e4 LT |
6777 | * call schedule, and on return reacquire the lock. |
6778 | * | |
41a2d6cf | 6779 | * This works OK both with and without CONFIG_PREEMPT. We do strange low-level |
1da177e4 LT |
6780 | * operations here to prevent schedule() from being called twice (once via |
6781 | * spin_unlock(), once by hand). | |
6782 | */ | |
613afbf8 | 6783 | int __cond_resched_lock(spinlock_t *lock) |
1da177e4 | 6784 | { |
d86ee480 | 6785 | int resched = should_resched(); |
6df3cecb JK |
6786 | int ret = 0; |
6787 | ||
f607c668 PZ |
6788 | lockdep_assert_held(lock); |
6789 | ||
95c354fe | 6790 | if (spin_needbreak(lock) || resched) { |
1da177e4 | 6791 | spin_unlock(lock); |
d86ee480 | 6792 | if (resched) |
95c354fe NP |
6793 | __cond_resched(); |
6794 | else | |
6795 | cpu_relax(); | |
6df3cecb | 6796 | ret = 1; |
1da177e4 | 6797 | spin_lock(lock); |
1da177e4 | 6798 | } |
6df3cecb | 6799 | return ret; |
1da177e4 | 6800 | } |
613afbf8 | 6801 | EXPORT_SYMBOL(__cond_resched_lock); |
1da177e4 | 6802 | |
613afbf8 | 6803 | int __sched __cond_resched_softirq(void) |
1da177e4 LT |
6804 | { |
6805 | BUG_ON(!in_softirq()); | |
6806 | ||
d86ee480 | 6807 | if (should_resched()) { |
98d82567 | 6808 | local_bh_enable(); |
1da177e4 LT |
6809 | __cond_resched(); |
6810 | local_bh_disable(); | |
6811 | return 1; | |
6812 | } | |
6813 | return 0; | |
6814 | } | |
613afbf8 | 6815 | EXPORT_SYMBOL(__cond_resched_softirq); |
1da177e4 | 6816 | |
1da177e4 LT |
6817 | /** |
6818 | * yield - yield the current processor to other threads. | |
6819 | * | |
72fd4a35 | 6820 | * This is a shortcut for kernel-space yielding - it marks the |
1da177e4 LT |
6821 | * thread runnable and calls sys_sched_yield(). |
6822 | */ | |
6823 | void __sched yield(void) | |
6824 | { | |
6825 | set_current_state(TASK_RUNNING); | |
6826 | sys_sched_yield(); | |
6827 | } | |
1da177e4 LT |
6828 | EXPORT_SYMBOL(yield); |
6829 | ||
6830 | /* | |
41a2d6cf | 6831 | * This task is about to go to sleep on IO. Increment rq->nr_iowait so |
1da177e4 | 6832 | * that process accounting knows that this is a task in IO wait state. |
1da177e4 LT |
6833 | */ |
6834 | void __sched io_schedule(void) | |
6835 | { | |
54d35f29 | 6836 | struct rq *rq = raw_rq(); |
1da177e4 | 6837 | |
0ff92245 | 6838 | delayacct_blkio_start(); |
1da177e4 | 6839 | atomic_inc(&rq->nr_iowait); |
8f0dfc34 | 6840 | current->in_iowait = 1; |
1da177e4 | 6841 | schedule(); |
8f0dfc34 | 6842 | current->in_iowait = 0; |
1da177e4 | 6843 | atomic_dec(&rq->nr_iowait); |
0ff92245 | 6844 | delayacct_blkio_end(); |
1da177e4 | 6845 | } |
1da177e4 LT |
6846 | EXPORT_SYMBOL(io_schedule); |
6847 | ||
6848 | long __sched io_schedule_timeout(long timeout) | |
6849 | { | |
54d35f29 | 6850 | struct rq *rq = raw_rq(); |
1da177e4 LT |
6851 | long ret; |
6852 | ||
0ff92245 | 6853 | delayacct_blkio_start(); |
1da177e4 | 6854 | atomic_inc(&rq->nr_iowait); |
8f0dfc34 | 6855 | current->in_iowait = 1; |
1da177e4 | 6856 | ret = schedule_timeout(timeout); |
8f0dfc34 | 6857 | current->in_iowait = 0; |
1da177e4 | 6858 | atomic_dec(&rq->nr_iowait); |
0ff92245 | 6859 | delayacct_blkio_end(); |
1da177e4 LT |
6860 | return ret; |
6861 | } | |
6862 | ||
6863 | /** | |
6864 | * sys_sched_get_priority_max - return maximum RT priority. | |
6865 | * @policy: scheduling class. | |
6866 | * | |
6867 | * this syscall returns the maximum rt_priority that can be used | |
6868 | * by a given scheduling class. | |
6869 | */ | |
5add95d4 | 6870 | SYSCALL_DEFINE1(sched_get_priority_max, int, policy) |
1da177e4 LT |
6871 | { |
6872 | int ret = -EINVAL; | |
6873 | ||
6874 | switch (policy) { | |
6875 | case SCHED_FIFO: | |
6876 | case SCHED_RR: | |
6877 | ret = MAX_USER_RT_PRIO-1; | |
6878 | break; | |
6879 | case SCHED_NORMAL: | |
b0a9499c | 6880 | case SCHED_BATCH: |
dd41f596 | 6881 | case SCHED_IDLE: |
1da177e4 LT |
6882 | ret = 0; |
6883 | break; | |
6884 | } | |
6885 | return ret; | |
6886 | } | |
6887 | ||
6888 | /** | |
6889 | * sys_sched_get_priority_min - return minimum RT priority. | |
6890 | * @policy: scheduling class. | |
6891 | * | |
6892 | * this syscall returns the minimum rt_priority that can be used | |
6893 | * by a given scheduling class. | |
6894 | */ | |
5add95d4 | 6895 | SYSCALL_DEFINE1(sched_get_priority_min, int, policy) |
1da177e4 LT |
6896 | { |
6897 | int ret = -EINVAL; | |
6898 | ||
6899 | switch (policy) { | |
6900 | case SCHED_FIFO: | |
6901 | case SCHED_RR: | |
6902 | ret = 1; | |
6903 | break; | |
6904 | case SCHED_NORMAL: | |
b0a9499c | 6905 | case SCHED_BATCH: |
dd41f596 | 6906 | case SCHED_IDLE: |
1da177e4 LT |
6907 | ret = 0; |
6908 | } | |
6909 | return ret; | |
6910 | } | |
6911 | ||
6912 | /** | |
6913 | * sys_sched_rr_get_interval - return the default timeslice of a process. | |
6914 | * @pid: pid of the process. | |
6915 | * @interval: userspace pointer to the timeslice value. | |
6916 | * | |
6917 | * this syscall writes the default timeslice value of a given process | |
6918 | * into the user-space timespec buffer. A value of '0' means infinity. | |
6919 | */ | |
17da2bd9 | 6920 | SYSCALL_DEFINE2(sched_rr_get_interval, pid_t, pid, |
754fe8d2 | 6921 | struct timespec __user *, interval) |
1da177e4 | 6922 | { |
36c8b586 | 6923 | struct task_struct *p; |
a4ec24b4 | 6924 | unsigned int time_slice; |
dba091b9 TG |
6925 | unsigned long flags; |
6926 | struct rq *rq; | |
3a5c359a | 6927 | int retval; |
1da177e4 | 6928 | struct timespec t; |
1da177e4 LT |
6929 | |
6930 | if (pid < 0) | |
3a5c359a | 6931 | return -EINVAL; |
1da177e4 LT |
6932 | |
6933 | retval = -ESRCH; | |
1a551ae7 | 6934 | rcu_read_lock(); |
1da177e4 LT |
6935 | p = find_process_by_pid(pid); |
6936 | if (!p) | |
6937 | goto out_unlock; | |
6938 | ||
6939 | retval = security_task_getscheduler(p); | |
6940 | if (retval) | |
6941 | goto out_unlock; | |
6942 | ||
dba091b9 TG |
6943 | rq = task_rq_lock(p, &flags); |
6944 | time_slice = p->sched_class->get_rr_interval(rq, p); | |
6945 | task_rq_unlock(rq, &flags); | |
a4ec24b4 | 6946 | |
1a551ae7 | 6947 | rcu_read_unlock(); |
a4ec24b4 | 6948 | jiffies_to_timespec(time_slice, &t); |
1da177e4 | 6949 | retval = copy_to_user(interval, &t, sizeof(t)) ? -EFAULT : 0; |
1da177e4 | 6950 | return retval; |
3a5c359a | 6951 | |
1da177e4 | 6952 | out_unlock: |
1a551ae7 | 6953 | rcu_read_unlock(); |
1da177e4 LT |
6954 | return retval; |
6955 | } | |
6956 | ||
7c731e0a | 6957 | static const char stat_nam[] = TASK_STATE_TO_CHAR_STR; |
36c8b586 | 6958 | |
82a1fcb9 | 6959 | void sched_show_task(struct task_struct *p) |
1da177e4 | 6960 | { |
1da177e4 | 6961 | unsigned long free = 0; |
36c8b586 | 6962 | unsigned state; |
1da177e4 | 6963 | |
1da177e4 | 6964 | state = p->state ? __ffs(p->state) + 1 : 0; |
3df0fc5b | 6965 | printk(KERN_INFO "%-13.13s %c", p->comm, |
2ed6e34f | 6966 | state < sizeof(stat_nam) - 1 ? stat_nam[state] : '?'); |
4bd77321 | 6967 | #if BITS_PER_LONG == 32 |
1da177e4 | 6968 | if (state == TASK_RUNNING) |
3df0fc5b | 6969 | printk(KERN_CONT " running "); |
1da177e4 | 6970 | else |
3df0fc5b | 6971 | printk(KERN_CONT " %08lx ", thread_saved_pc(p)); |
1da177e4 LT |
6972 | #else |
6973 | if (state == TASK_RUNNING) | |
3df0fc5b | 6974 | printk(KERN_CONT " running task "); |
1da177e4 | 6975 | else |
3df0fc5b | 6976 | printk(KERN_CONT " %016lx ", thread_saved_pc(p)); |
1da177e4 LT |
6977 | #endif |
6978 | #ifdef CONFIG_DEBUG_STACK_USAGE | |
7c9f8861 | 6979 | free = stack_not_used(p); |
1da177e4 | 6980 | #endif |
3df0fc5b | 6981 | printk(KERN_CONT "%5lu %5d %6d 0x%08lx\n", free, |
aa47b7e0 DR |
6982 | task_pid_nr(p), task_pid_nr(p->real_parent), |
6983 | (unsigned long)task_thread_info(p)->flags); | |
1da177e4 | 6984 | |
5fb5e6de | 6985 | show_stack(p, NULL); |
1da177e4 LT |
6986 | } |
6987 | ||
e59e2ae2 | 6988 | void show_state_filter(unsigned long state_filter) |
1da177e4 | 6989 | { |
36c8b586 | 6990 | struct task_struct *g, *p; |
1da177e4 | 6991 | |
4bd77321 | 6992 | #if BITS_PER_LONG == 32 |
3df0fc5b PZ |
6993 | printk(KERN_INFO |
6994 | " task PC stack pid father\n"); | |
1da177e4 | 6995 | #else |
3df0fc5b PZ |
6996 | printk(KERN_INFO |
6997 | " task PC stack pid father\n"); | |
1da177e4 LT |
6998 | #endif |
6999 | read_lock(&tasklist_lock); | |
7000 | do_each_thread(g, p) { | |
7001 | /* | |
7002 | * reset the NMI-timeout, listing all files on a slow | |
7003 | * console might take alot of time: | |
7004 | */ | |
7005 | touch_nmi_watchdog(); | |
39bc89fd | 7006 | if (!state_filter || (p->state & state_filter)) |
82a1fcb9 | 7007 | sched_show_task(p); |
1da177e4 LT |
7008 | } while_each_thread(g, p); |
7009 | ||
04c9167f JF |
7010 | touch_all_softlockup_watchdogs(); |
7011 | ||
dd41f596 IM |
7012 | #ifdef CONFIG_SCHED_DEBUG |
7013 | sysrq_sched_debug_show(); | |
7014 | #endif | |
1da177e4 | 7015 | read_unlock(&tasklist_lock); |
e59e2ae2 IM |
7016 | /* |
7017 | * Only show locks if all tasks are dumped: | |
7018 | */ | |
93335a21 | 7019 | if (!state_filter) |
e59e2ae2 | 7020 | debug_show_all_locks(); |
1da177e4 LT |
7021 | } |
7022 | ||
1df21055 IM |
7023 | void __cpuinit init_idle_bootup_task(struct task_struct *idle) |
7024 | { | |
dd41f596 | 7025 | idle->sched_class = &idle_sched_class; |
1df21055 IM |
7026 | } |
7027 | ||
f340c0d1 IM |
7028 | /** |
7029 | * init_idle - set up an idle thread for a given CPU | |
7030 | * @idle: task in question | |
7031 | * @cpu: cpu the idle task belongs to | |
7032 | * | |
7033 | * NOTE: this function does not set the idle thread's NEED_RESCHED | |
7034 | * flag, to make booting more robust. | |
7035 | */ | |
5c1e1767 | 7036 | void __cpuinit init_idle(struct task_struct *idle, int cpu) |
1da177e4 | 7037 | { |
70b97a7f | 7038 | struct rq *rq = cpu_rq(cpu); |
1da177e4 LT |
7039 | unsigned long flags; |
7040 | ||
05fa785c | 7041 | raw_spin_lock_irqsave(&rq->lock, flags); |
5cbd54ef | 7042 | |
dd41f596 | 7043 | __sched_fork(idle); |
06b83b5f | 7044 | idle->state = TASK_RUNNING; |
dd41f596 IM |
7045 | idle->se.exec_start = sched_clock(); |
7046 | ||
96f874e2 | 7047 | cpumask_copy(&idle->cpus_allowed, cpumask_of(cpu)); |
dd41f596 | 7048 | __set_task_cpu(idle, cpu); |
1da177e4 | 7049 | |
1da177e4 | 7050 | rq->curr = rq->idle = idle; |
4866cde0 NP |
7051 | #if defined(CONFIG_SMP) && defined(__ARCH_WANT_UNLOCKED_CTXSW) |
7052 | idle->oncpu = 1; | |
7053 | #endif | |
05fa785c | 7054 | raw_spin_unlock_irqrestore(&rq->lock, flags); |
1da177e4 LT |
7055 | |
7056 | /* Set the preempt count _outside_ the spinlocks! */ | |
8e3e076c LT |
7057 | #if defined(CONFIG_PREEMPT) |
7058 | task_thread_info(idle)->preempt_count = (idle->lock_depth >= 0); | |
7059 | #else | |
a1261f54 | 7060 | task_thread_info(idle)->preempt_count = 0; |
8e3e076c | 7061 | #endif |
dd41f596 IM |
7062 | /* |
7063 | * The idle tasks have their own, simple scheduling class: | |
7064 | */ | |
7065 | idle->sched_class = &idle_sched_class; | |
fb52607a | 7066 | ftrace_graph_init_task(idle); |
1da177e4 LT |
7067 | } |
7068 | ||
7069 | /* | |
7070 | * In a system that switches off the HZ timer nohz_cpu_mask | |
7071 | * indicates which cpus entered this state. This is used | |
7072 | * in the rcu update to wait only for active cpus. For system | |
7073 | * which do not switch off the HZ timer nohz_cpu_mask should | |
6a7b3dc3 | 7074 | * always be CPU_BITS_NONE. |
1da177e4 | 7075 | */ |
6a7b3dc3 | 7076 | cpumask_var_t nohz_cpu_mask; |
1da177e4 | 7077 | |
19978ca6 IM |
7078 | /* |
7079 | * Increase the granularity value when there are more CPUs, | |
7080 | * because with more CPUs the 'effective latency' as visible | |
7081 | * to users decreases. But the relationship is not linear, | |
7082 | * so pick a second-best guess by going with the log2 of the | |
7083 | * number of CPUs. | |
7084 | * | |
7085 | * This idea comes from the SD scheduler of Con Kolivas: | |
7086 | */ | |
acb4a848 | 7087 | static int get_update_sysctl_factor(void) |
19978ca6 | 7088 | { |
4ca3ef71 | 7089 | unsigned int cpus = min_t(int, num_online_cpus(), 8); |
1983a922 CE |
7090 | unsigned int factor; |
7091 | ||
7092 | switch (sysctl_sched_tunable_scaling) { | |
7093 | case SCHED_TUNABLESCALING_NONE: | |
7094 | factor = 1; | |
7095 | break; | |
7096 | case SCHED_TUNABLESCALING_LINEAR: | |
7097 | factor = cpus; | |
7098 | break; | |
7099 | case SCHED_TUNABLESCALING_LOG: | |
7100 | default: | |
7101 | factor = 1 + ilog2(cpus); | |
7102 | break; | |
7103 | } | |
19978ca6 | 7104 | |
acb4a848 CE |
7105 | return factor; |
7106 | } | |
19978ca6 | 7107 | |
acb4a848 CE |
7108 | static void update_sysctl(void) |
7109 | { | |
7110 | unsigned int factor = get_update_sysctl_factor(); | |
19978ca6 | 7111 | |
0bcdcf28 CE |
7112 | #define SET_SYSCTL(name) \ |
7113 | (sysctl_##name = (factor) * normalized_sysctl_##name) | |
7114 | SET_SYSCTL(sched_min_granularity); | |
7115 | SET_SYSCTL(sched_latency); | |
7116 | SET_SYSCTL(sched_wakeup_granularity); | |
7117 | SET_SYSCTL(sched_shares_ratelimit); | |
7118 | #undef SET_SYSCTL | |
7119 | } | |
55cd5340 | 7120 | |
0bcdcf28 CE |
7121 | static inline void sched_init_granularity(void) |
7122 | { | |
7123 | update_sysctl(); | |
19978ca6 IM |
7124 | } |
7125 | ||
1da177e4 LT |
7126 | #ifdef CONFIG_SMP |
7127 | /* | |
7128 | * This is how migration works: | |
7129 | * | |
70b97a7f | 7130 | * 1) we queue a struct migration_req structure in the source CPU's |
1da177e4 LT |
7131 | * runqueue and wake up that CPU's migration thread. |
7132 | * 2) we down() the locked semaphore => thread blocks. | |
7133 | * 3) migration thread wakes up (implicitly it forces the migrated | |
7134 | * thread off the CPU) | |
7135 | * 4) it gets the migration request and checks whether the migrated | |
7136 | * task is still in the wrong runqueue. | |
7137 | * 5) if it's in the wrong runqueue then the migration thread removes | |
7138 | * it and puts it into the right queue. | |
7139 | * 6) migration thread up()s the semaphore. | |
7140 | * 7) we wake up and the migration is done. | |
7141 | */ | |
7142 | ||
7143 | /* | |
7144 | * Change a given task's CPU affinity. Migrate the thread to a | |
7145 | * proper CPU and schedule it away if the CPU it's executing on | |
7146 | * is removed from the allowed bitmask. | |
7147 | * | |
7148 | * NOTE: the caller must have a valid reference to the task, the | |
41a2d6cf | 7149 | * task must not exit() & deallocate itself prematurely. The |
1da177e4 LT |
7150 | * call is not atomic; no spinlocks may be held. |
7151 | */ | |
96f874e2 | 7152 | int set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask) |
1da177e4 | 7153 | { |
70b97a7f | 7154 | struct migration_req req; |
1da177e4 | 7155 | unsigned long flags; |
70b97a7f | 7156 | struct rq *rq; |
48f24c4d | 7157 | int ret = 0; |
1da177e4 | 7158 | |
e2912009 PZ |
7159 | /* |
7160 | * Since we rely on wake-ups to migrate sleeping tasks, don't change | |
7161 | * the ->cpus_allowed mask from under waking tasks, which would be | |
7162 | * possible when we change rq->lock in ttwu(), so synchronize against | |
7163 | * TASK_WAKING to avoid that. | |
fabf318e PZ |
7164 | * |
7165 | * Make an exception for freshly cloned tasks, since cpuset namespaces | |
7166 | * might move the task about, we have to validate the target in | |
7167 | * wake_up_new_task() anyway since the cpu might have gone away. | |
e2912009 PZ |
7168 | */ |
7169 | again: | |
fabf318e | 7170 | while (p->state == TASK_WAKING && !(p->flags & PF_STARTING)) |
e2912009 PZ |
7171 | cpu_relax(); |
7172 | ||
1da177e4 | 7173 | rq = task_rq_lock(p, &flags); |
e2912009 | 7174 | |
fabf318e | 7175 | if (p->state == TASK_WAKING && !(p->flags & PF_STARTING)) { |
e2912009 PZ |
7176 | task_rq_unlock(rq, &flags); |
7177 | goto again; | |
7178 | } | |
7179 | ||
6ad4c188 | 7180 | if (!cpumask_intersects(new_mask, cpu_active_mask)) { |
1da177e4 LT |
7181 | ret = -EINVAL; |
7182 | goto out; | |
7183 | } | |
7184 | ||
9985b0ba | 7185 | if (unlikely((p->flags & PF_THREAD_BOUND) && p != current && |
96f874e2 | 7186 | !cpumask_equal(&p->cpus_allowed, new_mask))) { |
9985b0ba DR |
7187 | ret = -EINVAL; |
7188 | goto out; | |
7189 | } | |
7190 | ||
73fe6aae | 7191 | if (p->sched_class->set_cpus_allowed) |
cd8ba7cd | 7192 | p->sched_class->set_cpus_allowed(p, new_mask); |
73fe6aae | 7193 | else { |
96f874e2 RR |
7194 | cpumask_copy(&p->cpus_allowed, new_mask); |
7195 | p->rt.nr_cpus_allowed = cpumask_weight(new_mask); | |
73fe6aae GH |
7196 | } |
7197 | ||
1da177e4 | 7198 | /* Can the task run on the task's current CPU? If so, we're done */ |
96f874e2 | 7199 | if (cpumask_test_cpu(task_cpu(p), new_mask)) |
1da177e4 LT |
7200 | goto out; |
7201 | ||
6ad4c188 | 7202 | if (migrate_task(p, cpumask_any_and(cpu_active_mask, new_mask), &req)) { |
1da177e4 | 7203 | /* Need help from migration thread: drop lock and wait. */ |
693525e3 PZ |
7204 | struct task_struct *mt = rq->migration_thread; |
7205 | ||
7206 | get_task_struct(mt); | |
1da177e4 LT |
7207 | task_rq_unlock(rq, &flags); |
7208 | wake_up_process(rq->migration_thread); | |
693525e3 | 7209 | put_task_struct(mt); |
1da177e4 LT |
7210 | wait_for_completion(&req.done); |
7211 | tlb_migrate_finish(p->mm); | |
7212 | return 0; | |
7213 | } | |
7214 | out: | |
7215 | task_rq_unlock(rq, &flags); | |
48f24c4d | 7216 | |
1da177e4 LT |
7217 | return ret; |
7218 | } | |
cd8ba7cd | 7219 | EXPORT_SYMBOL_GPL(set_cpus_allowed_ptr); |
1da177e4 LT |
7220 | |
7221 | /* | |
41a2d6cf | 7222 | * Move (not current) task off this cpu, onto dest cpu. We're doing |
1da177e4 LT |
7223 | * this because either it can't run here any more (set_cpus_allowed() |
7224 | * away from this CPU, or CPU going down), or because we're | |
7225 | * attempting to rebalance this task on exec (sched_exec). | |
7226 | * | |
7227 | * So we race with normal scheduler movements, but that's OK, as long | |
7228 | * as the task is no longer on this CPU. | |
efc30814 KK |
7229 | * |
7230 | * Returns non-zero if task was successfully migrated. | |
1da177e4 | 7231 | */ |
efc30814 | 7232 | static int __migrate_task(struct task_struct *p, int src_cpu, int dest_cpu) |
1da177e4 | 7233 | { |
70b97a7f | 7234 | struct rq *rq_dest, *rq_src; |
e2912009 | 7235 | int ret = 0; |
1da177e4 | 7236 | |
e761b772 | 7237 | if (unlikely(!cpu_active(dest_cpu))) |
efc30814 | 7238 | return ret; |
1da177e4 LT |
7239 | |
7240 | rq_src = cpu_rq(src_cpu); | |
7241 | rq_dest = cpu_rq(dest_cpu); | |
7242 | ||
7243 | double_rq_lock(rq_src, rq_dest); | |
7244 | /* Already moved. */ | |
7245 | if (task_cpu(p) != src_cpu) | |
b1e38734 | 7246 | goto done; |
1da177e4 | 7247 | /* Affinity changed (again). */ |
96f874e2 | 7248 | if (!cpumask_test_cpu(dest_cpu, &p->cpus_allowed)) |
b1e38734 | 7249 | goto fail; |
1da177e4 | 7250 | |
e2912009 PZ |
7251 | /* |
7252 | * If we're not on a rq, the next wake-up will ensure we're | |
7253 | * placed properly. | |
7254 | */ | |
7255 | if (p->se.on_rq) { | |
2e1cb74a | 7256 | deactivate_task(rq_src, p, 0); |
e2912009 | 7257 | set_task_cpu(p, dest_cpu); |
dd41f596 | 7258 | activate_task(rq_dest, p, 0); |
15afe09b | 7259 | check_preempt_curr(rq_dest, p, 0); |
1da177e4 | 7260 | } |
b1e38734 | 7261 | done: |
efc30814 | 7262 | ret = 1; |
b1e38734 | 7263 | fail: |
1da177e4 | 7264 | double_rq_unlock(rq_src, rq_dest); |
efc30814 | 7265 | return ret; |
1da177e4 LT |
7266 | } |
7267 | ||
03b042bf PM |
7268 | #define RCU_MIGRATION_IDLE 0 |
7269 | #define RCU_MIGRATION_NEED_QS 1 | |
7270 | #define RCU_MIGRATION_GOT_QS 2 | |
7271 | #define RCU_MIGRATION_MUST_SYNC 3 | |
7272 | ||
1da177e4 LT |
7273 | /* |
7274 | * migration_thread - this is a highprio system thread that performs | |
7275 | * thread migration by bumping thread off CPU then 'pushing' onto | |
7276 | * another runqueue. | |
7277 | */ | |
95cdf3b7 | 7278 | static int migration_thread(void *data) |
1da177e4 | 7279 | { |
03b042bf | 7280 | int badcpu; |
1da177e4 | 7281 | int cpu = (long)data; |
70b97a7f | 7282 | struct rq *rq; |
1da177e4 LT |
7283 | |
7284 | rq = cpu_rq(cpu); | |
7285 | BUG_ON(rq->migration_thread != current); | |
7286 | ||
7287 | set_current_state(TASK_INTERRUPTIBLE); | |
7288 | while (!kthread_should_stop()) { | |
70b97a7f | 7289 | struct migration_req *req; |
1da177e4 | 7290 | struct list_head *head; |
1da177e4 | 7291 | |
05fa785c | 7292 | raw_spin_lock_irq(&rq->lock); |
1da177e4 LT |
7293 | |
7294 | if (cpu_is_offline(cpu)) { | |
05fa785c | 7295 | raw_spin_unlock_irq(&rq->lock); |
371cbb38 | 7296 | break; |
1da177e4 LT |
7297 | } |
7298 | ||
7299 | if (rq->active_balance) { | |
7300 | active_load_balance(rq, cpu); | |
7301 | rq->active_balance = 0; | |
7302 | } | |
7303 | ||
7304 | head = &rq->migration_queue; | |
7305 | ||
7306 | if (list_empty(head)) { | |
05fa785c | 7307 | raw_spin_unlock_irq(&rq->lock); |
1da177e4 LT |
7308 | schedule(); |
7309 | set_current_state(TASK_INTERRUPTIBLE); | |
7310 | continue; | |
7311 | } | |
70b97a7f | 7312 | req = list_entry(head->next, struct migration_req, list); |
1da177e4 LT |
7313 | list_del_init(head->next); |
7314 | ||
03b042bf | 7315 | if (req->task != NULL) { |
05fa785c | 7316 | raw_spin_unlock(&rq->lock); |
03b042bf PM |
7317 | __migrate_task(req->task, cpu, req->dest_cpu); |
7318 | } else if (likely(cpu == (badcpu = smp_processor_id()))) { | |
7319 | req->dest_cpu = RCU_MIGRATION_GOT_QS; | |
05fa785c | 7320 | raw_spin_unlock(&rq->lock); |
03b042bf PM |
7321 | } else { |
7322 | req->dest_cpu = RCU_MIGRATION_MUST_SYNC; | |
05fa785c | 7323 | raw_spin_unlock(&rq->lock); |
03b042bf PM |
7324 | WARN_ONCE(1, "migration_thread() on CPU %d, expected %d\n", badcpu, cpu); |
7325 | } | |
674311d5 | 7326 | local_irq_enable(); |
1da177e4 LT |
7327 | |
7328 | complete(&req->done); | |
7329 | } | |
7330 | __set_current_state(TASK_RUNNING); | |
1da177e4 | 7331 | |
1da177e4 LT |
7332 | return 0; |
7333 | } | |
7334 | ||
7335 | #ifdef CONFIG_HOTPLUG_CPU | |
f7b4cddc ON |
7336 | |
7337 | static int __migrate_task_irq(struct task_struct *p, int src_cpu, int dest_cpu) | |
7338 | { | |
7339 | int ret; | |
7340 | ||
7341 | local_irq_disable(); | |
7342 | ret = __migrate_task(p, src_cpu, dest_cpu); | |
7343 | local_irq_enable(); | |
7344 | return ret; | |
7345 | } | |
7346 | ||
054b9108 | 7347 | /* |
3a4fa0a2 | 7348 | * Figure out where task on dead CPU should go, use force if necessary. |
054b9108 | 7349 | */ |
48f24c4d | 7350 | static void move_task_off_dead_cpu(int dead_cpu, struct task_struct *p) |
1da177e4 | 7351 | { |
70b97a7f | 7352 | int dest_cpu; |
e76bd8d9 RR |
7353 | |
7354 | again: | |
5da9a0fb | 7355 | dest_cpu = select_fallback_rq(dead_cpu, p); |
e76bd8d9 | 7356 | |
e76bd8d9 RR |
7357 | /* It can have affinity changed while we were choosing. */ |
7358 | if (unlikely(!__migrate_task_irq(p, dead_cpu, dest_cpu))) | |
7359 | goto again; | |
1da177e4 LT |
7360 | } |
7361 | ||
7362 | /* | |
7363 | * While a dead CPU has no uninterruptible tasks queued at this point, | |
7364 | * it might still have a nonzero ->nr_uninterruptible counter, because | |
7365 | * for performance reasons the counter is not stricly tracking tasks to | |
7366 | * their home CPUs. So we just add the counter to another CPU's counter, | |
7367 | * to keep the global sum constant after CPU-down: | |
7368 | */ | |
70b97a7f | 7369 | static void migrate_nr_uninterruptible(struct rq *rq_src) |
1da177e4 | 7370 | { |
6ad4c188 | 7371 | struct rq *rq_dest = cpu_rq(cpumask_any(cpu_active_mask)); |
1da177e4 LT |
7372 | unsigned long flags; |
7373 | ||
7374 | local_irq_save(flags); | |
7375 | double_rq_lock(rq_src, rq_dest); | |
7376 | rq_dest->nr_uninterruptible += rq_src->nr_uninterruptible; | |
7377 | rq_src->nr_uninterruptible = 0; | |
7378 | double_rq_unlock(rq_src, rq_dest); | |
7379 | local_irq_restore(flags); | |
7380 | } | |
7381 | ||
7382 | /* Run through task list and migrate tasks from the dead cpu. */ | |
7383 | static void migrate_live_tasks(int src_cpu) | |
7384 | { | |
48f24c4d | 7385 | struct task_struct *p, *t; |
1da177e4 | 7386 | |
f7b4cddc | 7387 | read_lock(&tasklist_lock); |
1da177e4 | 7388 | |
48f24c4d IM |
7389 | do_each_thread(t, p) { |
7390 | if (p == current) | |
1da177e4 LT |
7391 | continue; |
7392 | ||
48f24c4d IM |
7393 | if (task_cpu(p) == src_cpu) |
7394 | move_task_off_dead_cpu(src_cpu, p); | |
7395 | } while_each_thread(t, p); | |
1da177e4 | 7396 | |
f7b4cddc | 7397 | read_unlock(&tasklist_lock); |
1da177e4 LT |
7398 | } |
7399 | ||
dd41f596 IM |
7400 | /* |
7401 | * Schedules idle task to be the next runnable task on current CPU. | |
94bc9a7b DA |
7402 | * It does so by boosting its priority to highest possible. |
7403 | * Used by CPU offline code. | |
1da177e4 LT |
7404 | */ |
7405 | void sched_idle_next(void) | |
7406 | { | |
48f24c4d | 7407 | int this_cpu = smp_processor_id(); |
70b97a7f | 7408 | struct rq *rq = cpu_rq(this_cpu); |
1da177e4 LT |
7409 | struct task_struct *p = rq->idle; |
7410 | unsigned long flags; | |
7411 | ||
7412 | /* cpu has to be offline */ | |
48f24c4d | 7413 | BUG_ON(cpu_online(this_cpu)); |
1da177e4 | 7414 | |
48f24c4d IM |
7415 | /* |
7416 | * Strictly not necessary since rest of the CPUs are stopped by now | |
7417 | * and interrupts disabled on the current cpu. | |
1da177e4 | 7418 | */ |
05fa785c | 7419 | raw_spin_lock_irqsave(&rq->lock, flags); |
1da177e4 | 7420 | |
dd41f596 | 7421 | __setscheduler(rq, p, SCHED_FIFO, MAX_RT_PRIO-1); |
48f24c4d | 7422 | |
94bc9a7b DA |
7423 | update_rq_clock(rq); |
7424 | activate_task(rq, p, 0); | |
1da177e4 | 7425 | |
05fa785c | 7426 | raw_spin_unlock_irqrestore(&rq->lock, flags); |
1da177e4 LT |
7427 | } |
7428 | ||
48f24c4d IM |
7429 | /* |
7430 | * Ensures that the idle task is using init_mm right before its cpu goes | |
1da177e4 LT |
7431 | * offline. |
7432 | */ | |
7433 | void idle_task_exit(void) | |
7434 | { | |
7435 | struct mm_struct *mm = current->active_mm; | |
7436 | ||
7437 | BUG_ON(cpu_online(smp_processor_id())); | |
7438 | ||
7439 | if (mm != &init_mm) | |
7440 | switch_mm(mm, &init_mm, current); | |
7441 | mmdrop(mm); | |
7442 | } | |
7443 | ||
054b9108 | 7444 | /* called under rq->lock with disabled interrupts */ |
36c8b586 | 7445 | static void migrate_dead(unsigned int dead_cpu, struct task_struct *p) |
1da177e4 | 7446 | { |
70b97a7f | 7447 | struct rq *rq = cpu_rq(dead_cpu); |
1da177e4 LT |
7448 | |
7449 | /* Must be exiting, otherwise would be on tasklist. */ | |
270f722d | 7450 | BUG_ON(!p->exit_state); |
1da177e4 LT |
7451 | |
7452 | /* Cannot have done final schedule yet: would have vanished. */ | |
c394cc9f | 7453 | BUG_ON(p->state == TASK_DEAD); |
1da177e4 | 7454 | |
48f24c4d | 7455 | get_task_struct(p); |
1da177e4 LT |
7456 | |
7457 | /* | |
7458 | * Drop lock around migration; if someone else moves it, | |
41a2d6cf | 7459 | * that's OK. No task can be added to this CPU, so iteration is |
1da177e4 LT |
7460 | * fine. |
7461 | */ | |
05fa785c | 7462 | raw_spin_unlock_irq(&rq->lock); |
48f24c4d | 7463 | move_task_off_dead_cpu(dead_cpu, p); |
05fa785c | 7464 | raw_spin_lock_irq(&rq->lock); |
1da177e4 | 7465 | |
48f24c4d | 7466 | put_task_struct(p); |
1da177e4 LT |
7467 | } |
7468 | ||
7469 | /* release_task() removes task from tasklist, so we won't find dead tasks. */ | |
7470 | static void migrate_dead_tasks(unsigned int dead_cpu) | |
7471 | { | |
70b97a7f | 7472 | struct rq *rq = cpu_rq(dead_cpu); |
dd41f596 | 7473 | struct task_struct *next; |
48f24c4d | 7474 | |
dd41f596 IM |
7475 | for ( ; ; ) { |
7476 | if (!rq->nr_running) | |
7477 | break; | |
a8e504d2 | 7478 | update_rq_clock(rq); |
b67802ea | 7479 | next = pick_next_task(rq); |
dd41f596 IM |
7480 | if (!next) |
7481 | break; | |
79c53799 | 7482 | next->sched_class->put_prev_task(rq, next); |
dd41f596 | 7483 | migrate_dead(dead_cpu, next); |
e692ab53 | 7484 | |
1da177e4 LT |
7485 | } |
7486 | } | |
dce48a84 TG |
7487 | |
7488 | /* | |
7489 | * remove the tasks which were accounted by rq from calc_load_tasks. | |
7490 | */ | |
7491 | static void calc_global_load_remove(struct rq *rq) | |
7492 | { | |
7493 | atomic_long_sub(rq->calc_load_active, &calc_load_tasks); | |
a468d389 | 7494 | rq->calc_load_active = 0; |
dce48a84 | 7495 | } |
1da177e4 LT |
7496 | #endif /* CONFIG_HOTPLUG_CPU */ |
7497 | ||
e692ab53 NP |
7498 | #if defined(CONFIG_SCHED_DEBUG) && defined(CONFIG_SYSCTL) |
7499 | ||
7500 | static struct ctl_table sd_ctl_dir[] = { | |
e0361851 AD |
7501 | { |
7502 | .procname = "sched_domain", | |
c57baf1e | 7503 | .mode = 0555, |
e0361851 | 7504 | }, |
56992309 | 7505 | {} |
e692ab53 NP |
7506 | }; |
7507 | ||
7508 | static struct ctl_table sd_ctl_root[] = { | |
e0361851 AD |
7509 | { |
7510 | .procname = "kernel", | |
c57baf1e | 7511 | .mode = 0555, |
e0361851 AD |
7512 | .child = sd_ctl_dir, |
7513 | }, | |
56992309 | 7514 | {} |
e692ab53 NP |
7515 | }; |
7516 | ||
7517 | static struct ctl_table *sd_alloc_ctl_entry(int n) | |
7518 | { | |
7519 | struct ctl_table *entry = | |
5cf9f062 | 7520 | kcalloc(n, sizeof(struct ctl_table), GFP_KERNEL); |
e692ab53 | 7521 | |
e692ab53 NP |
7522 | return entry; |
7523 | } | |
7524 | ||
6382bc90 MM |
7525 | static void sd_free_ctl_entry(struct ctl_table **tablep) |
7526 | { | |
cd790076 | 7527 | struct ctl_table *entry; |
6382bc90 | 7528 | |
cd790076 MM |
7529 | /* |
7530 | * In the intermediate directories, both the child directory and | |
7531 | * procname are dynamically allocated and could fail but the mode | |
41a2d6cf | 7532 | * will always be set. In the lowest directory the names are |
cd790076 MM |
7533 | * static strings and all have proc handlers. |
7534 | */ | |
7535 | for (entry = *tablep; entry->mode; entry++) { | |
6382bc90 MM |
7536 | if (entry->child) |
7537 | sd_free_ctl_entry(&entry->child); | |
cd790076 MM |
7538 | if (entry->proc_handler == NULL) |
7539 | kfree(entry->procname); | |
7540 | } | |
6382bc90 MM |
7541 | |
7542 | kfree(*tablep); | |
7543 | *tablep = NULL; | |
7544 | } | |
7545 | ||
e692ab53 | 7546 | static void |
e0361851 | 7547 | set_table_entry(struct ctl_table *entry, |
e692ab53 NP |
7548 | const char *procname, void *data, int maxlen, |
7549 | mode_t mode, proc_handler *proc_handler) | |
7550 | { | |
e692ab53 NP |
7551 | entry->procname = procname; |
7552 | entry->data = data; | |
7553 | entry->maxlen = maxlen; | |
7554 | entry->mode = mode; | |
7555 | entry->proc_handler = proc_handler; | |
7556 | } | |
7557 | ||
7558 | static struct ctl_table * | |
7559 | sd_alloc_ctl_domain_table(struct sched_domain *sd) | |
7560 | { | |
a5d8c348 | 7561 | struct ctl_table *table = sd_alloc_ctl_entry(13); |
e692ab53 | 7562 | |
ad1cdc1d MM |
7563 | if (table == NULL) |
7564 | return NULL; | |
7565 | ||
e0361851 | 7566 | set_table_entry(&table[0], "min_interval", &sd->min_interval, |
e692ab53 | 7567 | sizeof(long), 0644, proc_doulongvec_minmax); |
e0361851 | 7568 | set_table_entry(&table[1], "max_interval", &sd->max_interval, |
e692ab53 | 7569 | sizeof(long), 0644, proc_doulongvec_minmax); |
e0361851 | 7570 | set_table_entry(&table[2], "busy_idx", &sd->busy_idx, |
e692ab53 | 7571 | sizeof(int), 0644, proc_dointvec_minmax); |
e0361851 | 7572 | set_table_entry(&table[3], "idle_idx", &sd->idle_idx, |
e692ab53 | 7573 | sizeof(int), 0644, proc_dointvec_minmax); |
e0361851 | 7574 | set_table_entry(&table[4], "newidle_idx", &sd->newidle_idx, |
e692ab53 | 7575 | sizeof(int), 0644, proc_dointvec_minmax); |
e0361851 | 7576 | set_table_entry(&table[5], "wake_idx", &sd->wake_idx, |
e692ab53 | 7577 | sizeof(int), 0644, proc_dointvec_minmax); |
e0361851 | 7578 | set_table_entry(&table[6], "forkexec_idx", &sd->forkexec_idx, |
e692ab53 | 7579 | sizeof(int), 0644, proc_dointvec_minmax); |
e0361851 | 7580 | set_table_entry(&table[7], "busy_factor", &sd->busy_factor, |
e692ab53 | 7581 | sizeof(int), 0644, proc_dointvec_minmax); |
e0361851 | 7582 | set_table_entry(&table[8], "imbalance_pct", &sd->imbalance_pct, |
e692ab53 | 7583 | sizeof(int), 0644, proc_dointvec_minmax); |
ace8b3d6 | 7584 | set_table_entry(&table[9], "cache_nice_tries", |
e692ab53 NP |
7585 | &sd->cache_nice_tries, |
7586 | sizeof(int), 0644, proc_dointvec_minmax); | |
ace8b3d6 | 7587 | set_table_entry(&table[10], "flags", &sd->flags, |
e692ab53 | 7588 | sizeof(int), 0644, proc_dointvec_minmax); |
a5d8c348 IM |
7589 | set_table_entry(&table[11], "name", sd->name, |
7590 | CORENAME_MAX_SIZE, 0444, proc_dostring); | |
7591 | /* &table[12] is terminator */ | |
e692ab53 NP |
7592 | |
7593 | return table; | |
7594 | } | |
7595 | ||
9a4e7159 | 7596 | static ctl_table *sd_alloc_ctl_cpu_table(int cpu) |
e692ab53 NP |
7597 | { |
7598 | struct ctl_table *entry, *table; | |
7599 | struct sched_domain *sd; | |
7600 | int domain_num = 0, i; | |
7601 | char buf[32]; | |
7602 | ||
7603 | for_each_domain(cpu, sd) | |
7604 | domain_num++; | |
7605 | entry = table = sd_alloc_ctl_entry(domain_num + 1); | |
ad1cdc1d MM |
7606 | if (table == NULL) |
7607 | return NULL; | |
e692ab53 NP |
7608 | |
7609 | i = 0; | |
7610 | for_each_domain(cpu, sd) { | |
7611 | snprintf(buf, 32, "domain%d", i); | |
e692ab53 | 7612 | entry->procname = kstrdup(buf, GFP_KERNEL); |
c57baf1e | 7613 | entry->mode = 0555; |
e692ab53 NP |
7614 | entry->child = sd_alloc_ctl_domain_table(sd); |
7615 | entry++; | |
7616 | i++; | |
7617 | } | |
7618 | return table; | |
7619 | } | |
7620 | ||
7621 | static struct ctl_table_header *sd_sysctl_header; | |
6382bc90 | 7622 | static void register_sched_domain_sysctl(void) |
e692ab53 | 7623 | { |
6ad4c188 | 7624 | int i, cpu_num = num_possible_cpus(); |
e692ab53 NP |
7625 | struct ctl_table *entry = sd_alloc_ctl_entry(cpu_num + 1); |
7626 | char buf[32]; | |
7627 | ||
7378547f MM |
7628 | WARN_ON(sd_ctl_dir[0].child); |
7629 | sd_ctl_dir[0].child = entry; | |
7630 | ||
ad1cdc1d MM |
7631 | if (entry == NULL) |
7632 | return; | |
7633 | ||
6ad4c188 | 7634 | for_each_possible_cpu(i) { |
e692ab53 | 7635 | snprintf(buf, 32, "cpu%d", i); |
e692ab53 | 7636 | entry->procname = kstrdup(buf, GFP_KERNEL); |
c57baf1e | 7637 | entry->mode = 0555; |
e692ab53 | 7638 | entry->child = sd_alloc_ctl_cpu_table(i); |
97b6ea7b | 7639 | entry++; |
e692ab53 | 7640 | } |
7378547f MM |
7641 | |
7642 | WARN_ON(sd_sysctl_header); | |
e692ab53 NP |
7643 | sd_sysctl_header = register_sysctl_table(sd_ctl_root); |
7644 | } | |
6382bc90 | 7645 | |
7378547f | 7646 | /* may be called multiple times per register */ |
6382bc90 MM |
7647 | static void unregister_sched_domain_sysctl(void) |
7648 | { | |
7378547f MM |
7649 | if (sd_sysctl_header) |
7650 | unregister_sysctl_table(sd_sysctl_header); | |
6382bc90 | 7651 | sd_sysctl_header = NULL; |
7378547f MM |
7652 | if (sd_ctl_dir[0].child) |
7653 | sd_free_ctl_entry(&sd_ctl_dir[0].child); | |
6382bc90 | 7654 | } |
e692ab53 | 7655 | #else |
6382bc90 MM |
7656 | static void register_sched_domain_sysctl(void) |
7657 | { | |
7658 | } | |
7659 | static void unregister_sched_domain_sysctl(void) | |
e692ab53 NP |
7660 | { |
7661 | } | |
7662 | #endif | |
7663 | ||
1f11eb6a GH |
7664 | static void set_rq_online(struct rq *rq) |
7665 | { | |
7666 | if (!rq->online) { | |
7667 | const struct sched_class *class; | |
7668 | ||
c6c4927b | 7669 | cpumask_set_cpu(rq->cpu, rq->rd->online); |
1f11eb6a GH |
7670 | rq->online = 1; |
7671 | ||
7672 | for_each_class(class) { | |
7673 | if (class->rq_online) | |
7674 | class->rq_online(rq); | |
7675 | } | |
7676 | } | |
7677 | } | |
7678 | ||
7679 | static void set_rq_offline(struct rq *rq) | |
7680 | { | |
7681 | if (rq->online) { | |
7682 | const struct sched_class *class; | |
7683 | ||
7684 | for_each_class(class) { | |
7685 | if (class->rq_offline) | |
7686 | class->rq_offline(rq); | |
7687 | } | |
7688 | ||
c6c4927b | 7689 | cpumask_clear_cpu(rq->cpu, rq->rd->online); |
1f11eb6a GH |
7690 | rq->online = 0; |
7691 | } | |
7692 | } | |
7693 | ||
1da177e4 LT |
7694 | /* |
7695 | * migration_call - callback that gets triggered when a CPU is added. | |
7696 | * Here we can start up the necessary migration thread for the new CPU. | |
7697 | */ | |
48f24c4d IM |
7698 | static int __cpuinit |
7699 | migration_call(struct notifier_block *nfb, unsigned long action, void *hcpu) | |
1da177e4 | 7700 | { |
1da177e4 | 7701 | struct task_struct *p; |
48f24c4d | 7702 | int cpu = (long)hcpu; |
1da177e4 | 7703 | unsigned long flags; |
70b97a7f | 7704 | struct rq *rq; |
1da177e4 LT |
7705 | |
7706 | switch (action) { | |
5be9361c | 7707 | |
1da177e4 | 7708 | case CPU_UP_PREPARE: |
8bb78442 | 7709 | case CPU_UP_PREPARE_FROZEN: |
dd41f596 | 7710 | p = kthread_create(migration_thread, hcpu, "migration/%d", cpu); |
1da177e4 LT |
7711 | if (IS_ERR(p)) |
7712 | return NOTIFY_BAD; | |
1da177e4 LT |
7713 | kthread_bind(p, cpu); |
7714 | /* Must be high prio: stop_machine expects to yield to it. */ | |
7715 | rq = task_rq_lock(p, &flags); | |
dd41f596 | 7716 | __setscheduler(rq, p, SCHED_FIFO, MAX_RT_PRIO-1); |
1da177e4 | 7717 | task_rq_unlock(rq, &flags); |
371cbb38 | 7718 | get_task_struct(p); |
1da177e4 | 7719 | cpu_rq(cpu)->migration_thread = p; |
a468d389 | 7720 | rq->calc_load_update = calc_load_update; |
1da177e4 | 7721 | break; |
48f24c4d | 7722 | |
1da177e4 | 7723 | case CPU_ONLINE: |
8bb78442 | 7724 | case CPU_ONLINE_FROZEN: |
3a4fa0a2 | 7725 | /* Strictly unnecessary, as first user will wake it. */ |
1da177e4 | 7726 | wake_up_process(cpu_rq(cpu)->migration_thread); |
1f94ef59 GH |
7727 | |
7728 | /* Update our root-domain */ | |
7729 | rq = cpu_rq(cpu); | |
05fa785c | 7730 | raw_spin_lock_irqsave(&rq->lock, flags); |
1f94ef59 | 7731 | if (rq->rd) { |
c6c4927b | 7732 | BUG_ON(!cpumask_test_cpu(cpu, rq->rd->span)); |
1f11eb6a GH |
7733 | |
7734 | set_rq_online(rq); | |
1f94ef59 | 7735 | } |
05fa785c | 7736 | raw_spin_unlock_irqrestore(&rq->lock, flags); |
1da177e4 | 7737 | break; |
48f24c4d | 7738 | |
1da177e4 LT |
7739 | #ifdef CONFIG_HOTPLUG_CPU |
7740 | case CPU_UP_CANCELED: | |
8bb78442 | 7741 | case CPU_UP_CANCELED_FROZEN: |
fc75cdfa HC |
7742 | if (!cpu_rq(cpu)->migration_thread) |
7743 | break; | |
41a2d6cf | 7744 | /* Unbind it from offline cpu so it can run. Fall thru. */ |
a4c4af7c | 7745 | kthread_bind(cpu_rq(cpu)->migration_thread, |
1e5ce4f4 | 7746 | cpumask_any(cpu_online_mask)); |
1da177e4 | 7747 | kthread_stop(cpu_rq(cpu)->migration_thread); |
371cbb38 | 7748 | put_task_struct(cpu_rq(cpu)->migration_thread); |
1da177e4 LT |
7749 | cpu_rq(cpu)->migration_thread = NULL; |
7750 | break; | |
48f24c4d | 7751 | |
1da177e4 | 7752 | case CPU_DEAD: |
8bb78442 | 7753 | case CPU_DEAD_FROZEN: |
470fd646 | 7754 | cpuset_lock(); /* around calls to cpuset_cpus_allowed_lock() */ |
1da177e4 LT |
7755 | migrate_live_tasks(cpu); |
7756 | rq = cpu_rq(cpu); | |
7757 | kthread_stop(rq->migration_thread); | |
371cbb38 | 7758 | put_task_struct(rq->migration_thread); |
1da177e4 LT |
7759 | rq->migration_thread = NULL; |
7760 | /* Idle task back to normal (off runqueue, low prio) */ | |
05fa785c | 7761 | raw_spin_lock_irq(&rq->lock); |
a8e504d2 | 7762 | update_rq_clock(rq); |
2e1cb74a | 7763 | deactivate_task(rq, rq->idle, 0); |
dd41f596 IM |
7764 | __setscheduler(rq, rq->idle, SCHED_NORMAL, 0); |
7765 | rq->idle->sched_class = &idle_sched_class; | |
1da177e4 | 7766 | migrate_dead_tasks(cpu); |
05fa785c | 7767 | raw_spin_unlock_irq(&rq->lock); |
470fd646 | 7768 | cpuset_unlock(); |
1da177e4 LT |
7769 | migrate_nr_uninterruptible(rq); |
7770 | BUG_ON(rq->nr_running != 0); | |
dce48a84 | 7771 | calc_global_load_remove(rq); |
41a2d6cf IM |
7772 | /* |
7773 | * No need to migrate the tasks: it was best-effort if | |
7774 | * they didn't take sched_hotcpu_mutex. Just wake up | |
7775 | * the requestors. | |
7776 | */ | |
05fa785c | 7777 | raw_spin_lock_irq(&rq->lock); |
1da177e4 | 7778 | while (!list_empty(&rq->migration_queue)) { |
70b97a7f IM |
7779 | struct migration_req *req; |
7780 | ||
1da177e4 | 7781 | req = list_entry(rq->migration_queue.next, |
70b97a7f | 7782 | struct migration_req, list); |
1da177e4 | 7783 | list_del_init(&req->list); |
05fa785c | 7784 | raw_spin_unlock_irq(&rq->lock); |
1da177e4 | 7785 | complete(&req->done); |
05fa785c | 7786 | raw_spin_lock_irq(&rq->lock); |
1da177e4 | 7787 | } |
05fa785c | 7788 | raw_spin_unlock_irq(&rq->lock); |
1da177e4 | 7789 | break; |
57d885fe | 7790 | |
08f503b0 GH |
7791 | case CPU_DYING: |
7792 | case CPU_DYING_FROZEN: | |
57d885fe GH |
7793 | /* Update our root-domain */ |
7794 | rq = cpu_rq(cpu); | |
05fa785c | 7795 | raw_spin_lock_irqsave(&rq->lock, flags); |
57d885fe | 7796 | if (rq->rd) { |
c6c4927b | 7797 | BUG_ON(!cpumask_test_cpu(cpu, rq->rd->span)); |
1f11eb6a | 7798 | set_rq_offline(rq); |
57d885fe | 7799 | } |
05fa785c | 7800 | raw_spin_unlock_irqrestore(&rq->lock, flags); |
57d885fe | 7801 | break; |
1da177e4 LT |
7802 | #endif |
7803 | } | |
7804 | return NOTIFY_OK; | |
7805 | } | |
7806 | ||
f38b0820 PM |
7807 | /* |
7808 | * Register at high priority so that task migration (migrate_all_tasks) | |
7809 | * happens before everything else. This has to be lower priority than | |
cdd6c482 | 7810 | * the notifier in the perf_event subsystem, though. |
1da177e4 | 7811 | */ |
26c2143b | 7812 | static struct notifier_block __cpuinitdata migration_notifier = { |
1da177e4 LT |
7813 | .notifier_call = migration_call, |
7814 | .priority = 10 | |
7815 | }; | |
7816 | ||
7babe8db | 7817 | static int __init migration_init(void) |
1da177e4 LT |
7818 | { |
7819 | void *cpu = (void *)(long)smp_processor_id(); | |
07dccf33 | 7820 | int err; |
48f24c4d IM |
7821 | |
7822 | /* Start one for the boot CPU: */ | |
07dccf33 AM |
7823 | err = migration_call(&migration_notifier, CPU_UP_PREPARE, cpu); |
7824 | BUG_ON(err == NOTIFY_BAD); | |
1da177e4 LT |
7825 | migration_call(&migration_notifier, CPU_ONLINE, cpu); |
7826 | register_cpu_notifier(&migration_notifier); | |
7babe8db | 7827 | |
a004cd42 | 7828 | return 0; |
1da177e4 | 7829 | } |
7babe8db | 7830 | early_initcall(migration_init); |
1da177e4 LT |
7831 | #endif |
7832 | ||
7833 | #ifdef CONFIG_SMP | |
476f3534 | 7834 | |
3e9830dc | 7835 | #ifdef CONFIG_SCHED_DEBUG |
4dcf6aff | 7836 | |
f6630114 MT |
7837 | static __read_mostly int sched_domain_debug_enabled; |
7838 | ||
7839 | static int __init sched_domain_debug_setup(char *str) | |
7840 | { | |
7841 | sched_domain_debug_enabled = 1; | |
7842 | ||
7843 | return 0; | |
7844 | } | |
7845 | early_param("sched_debug", sched_domain_debug_setup); | |
7846 | ||
7c16ec58 | 7847 | static int sched_domain_debug_one(struct sched_domain *sd, int cpu, int level, |
96f874e2 | 7848 | struct cpumask *groupmask) |
1da177e4 | 7849 | { |
4dcf6aff | 7850 | struct sched_group *group = sd->groups; |
434d53b0 | 7851 | char str[256]; |
1da177e4 | 7852 | |
968ea6d8 | 7853 | cpulist_scnprintf(str, sizeof(str), sched_domain_span(sd)); |
96f874e2 | 7854 | cpumask_clear(groupmask); |
4dcf6aff IM |
7855 | |
7856 | printk(KERN_DEBUG "%*s domain %d: ", level, "", level); | |
7857 | ||
7858 | if (!(sd->flags & SD_LOAD_BALANCE)) { | |
3df0fc5b | 7859 | printk("does not load-balance\n"); |
4dcf6aff | 7860 | if (sd->parent) |
3df0fc5b PZ |
7861 | printk(KERN_ERR "ERROR: !SD_LOAD_BALANCE domain" |
7862 | " has parent"); | |
4dcf6aff | 7863 | return -1; |
41c7ce9a NP |
7864 | } |
7865 | ||
3df0fc5b | 7866 | printk(KERN_CONT "span %s level %s\n", str, sd->name); |
4dcf6aff | 7867 | |
758b2cdc | 7868 | if (!cpumask_test_cpu(cpu, sched_domain_span(sd))) { |
3df0fc5b PZ |
7869 | printk(KERN_ERR "ERROR: domain->span does not contain " |
7870 | "CPU%d\n", cpu); | |
4dcf6aff | 7871 | } |
758b2cdc | 7872 | if (!cpumask_test_cpu(cpu, sched_group_cpus(group))) { |
3df0fc5b PZ |
7873 | printk(KERN_ERR "ERROR: domain->groups does not contain" |
7874 | " CPU%d\n", cpu); | |
4dcf6aff | 7875 | } |
1da177e4 | 7876 | |
4dcf6aff | 7877 | printk(KERN_DEBUG "%*s groups:", level + 1, ""); |
1da177e4 | 7878 | do { |
4dcf6aff | 7879 | if (!group) { |
3df0fc5b PZ |
7880 | printk("\n"); |
7881 | printk(KERN_ERR "ERROR: group is NULL\n"); | |
1da177e4 LT |
7882 | break; |
7883 | } | |
7884 | ||
18a3885f | 7885 | if (!group->cpu_power) { |
3df0fc5b PZ |
7886 | printk(KERN_CONT "\n"); |
7887 | printk(KERN_ERR "ERROR: domain->cpu_power not " | |
7888 | "set\n"); | |
4dcf6aff IM |
7889 | break; |
7890 | } | |
1da177e4 | 7891 | |
758b2cdc | 7892 | if (!cpumask_weight(sched_group_cpus(group))) { |
3df0fc5b PZ |
7893 | printk(KERN_CONT "\n"); |
7894 | printk(KERN_ERR "ERROR: empty group\n"); | |
4dcf6aff IM |
7895 | break; |
7896 | } | |
1da177e4 | 7897 | |
758b2cdc | 7898 | if (cpumask_intersects(groupmask, sched_group_cpus(group))) { |
3df0fc5b PZ |
7899 | printk(KERN_CONT "\n"); |
7900 | printk(KERN_ERR "ERROR: repeated CPUs\n"); | |
4dcf6aff IM |
7901 | break; |
7902 | } | |
1da177e4 | 7903 | |
758b2cdc | 7904 | cpumask_or(groupmask, groupmask, sched_group_cpus(group)); |
1da177e4 | 7905 | |
968ea6d8 | 7906 | cpulist_scnprintf(str, sizeof(str), sched_group_cpus(group)); |
381512cf | 7907 | |
3df0fc5b | 7908 | printk(KERN_CONT " %s", str); |
18a3885f | 7909 | if (group->cpu_power != SCHED_LOAD_SCALE) { |
3df0fc5b PZ |
7910 | printk(KERN_CONT " (cpu_power = %d)", |
7911 | group->cpu_power); | |
381512cf | 7912 | } |
1da177e4 | 7913 | |
4dcf6aff IM |
7914 | group = group->next; |
7915 | } while (group != sd->groups); | |
3df0fc5b | 7916 | printk(KERN_CONT "\n"); |
1da177e4 | 7917 | |
758b2cdc | 7918 | if (!cpumask_equal(sched_domain_span(sd), groupmask)) |
3df0fc5b | 7919 | printk(KERN_ERR "ERROR: groups don't span domain->span\n"); |
1da177e4 | 7920 | |
758b2cdc RR |
7921 | if (sd->parent && |
7922 | !cpumask_subset(groupmask, sched_domain_span(sd->parent))) | |
3df0fc5b PZ |
7923 | printk(KERN_ERR "ERROR: parent span is not a superset " |
7924 | "of domain->span\n"); | |
4dcf6aff IM |
7925 | return 0; |
7926 | } | |
1da177e4 | 7927 | |
4dcf6aff IM |
7928 | static void sched_domain_debug(struct sched_domain *sd, int cpu) |
7929 | { | |
d5dd3db1 | 7930 | cpumask_var_t groupmask; |
4dcf6aff | 7931 | int level = 0; |
1da177e4 | 7932 | |
f6630114 MT |
7933 | if (!sched_domain_debug_enabled) |
7934 | return; | |
7935 | ||
4dcf6aff IM |
7936 | if (!sd) { |
7937 | printk(KERN_DEBUG "CPU%d attaching NULL sched-domain.\n", cpu); | |
7938 | return; | |
7939 | } | |
1da177e4 | 7940 | |
4dcf6aff IM |
7941 | printk(KERN_DEBUG "CPU%d attaching sched-domain:\n", cpu); |
7942 | ||
d5dd3db1 | 7943 | if (!alloc_cpumask_var(&groupmask, GFP_KERNEL)) { |
7c16ec58 MT |
7944 | printk(KERN_DEBUG "Cannot load-balance (out of memory)\n"); |
7945 | return; | |
7946 | } | |
7947 | ||
4dcf6aff | 7948 | for (;;) { |
7c16ec58 | 7949 | if (sched_domain_debug_one(sd, cpu, level, groupmask)) |
4dcf6aff | 7950 | break; |
1da177e4 LT |
7951 | level++; |
7952 | sd = sd->parent; | |
33859f7f | 7953 | if (!sd) |
4dcf6aff IM |
7954 | break; |
7955 | } | |
d5dd3db1 | 7956 | free_cpumask_var(groupmask); |
1da177e4 | 7957 | } |
6d6bc0ad | 7958 | #else /* !CONFIG_SCHED_DEBUG */ |
48f24c4d | 7959 | # define sched_domain_debug(sd, cpu) do { } while (0) |
6d6bc0ad | 7960 | #endif /* CONFIG_SCHED_DEBUG */ |
1da177e4 | 7961 | |
1a20ff27 | 7962 | static int sd_degenerate(struct sched_domain *sd) |
245af2c7 | 7963 | { |
758b2cdc | 7964 | if (cpumask_weight(sched_domain_span(sd)) == 1) |
245af2c7 SS |
7965 | return 1; |
7966 | ||
7967 | /* Following flags need at least 2 groups */ | |
7968 | if (sd->flags & (SD_LOAD_BALANCE | | |
7969 | SD_BALANCE_NEWIDLE | | |
7970 | SD_BALANCE_FORK | | |
89c4710e SS |
7971 | SD_BALANCE_EXEC | |
7972 | SD_SHARE_CPUPOWER | | |
7973 | SD_SHARE_PKG_RESOURCES)) { | |
245af2c7 SS |
7974 | if (sd->groups != sd->groups->next) |
7975 | return 0; | |
7976 | } | |
7977 | ||
7978 | /* Following flags don't use groups */ | |
c88d5910 | 7979 | if (sd->flags & (SD_WAKE_AFFINE)) |
245af2c7 SS |
7980 | return 0; |
7981 | ||
7982 | return 1; | |
7983 | } | |
7984 | ||
48f24c4d IM |
7985 | static int |
7986 | sd_parent_degenerate(struct sched_domain *sd, struct sched_domain *parent) | |
245af2c7 SS |
7987 | { |
7988 | unsigned long cflags = sd->flags, pflags = parent->flags; | |
7989 | ||
7990 | if (sd_degenerate(parent)) | |
7991 | return 1; | |
7992 | ||
758b2cdc | 7993 | if (!cpumask_equal(sched_domain_span(sd), sched_domain_span(parent))) |
245af2c7 SS |
7994 | return 0; |
7995 | ||
245af2c7 SS |
7996 | /* Flags needing groups don't count if only 1 group in parent */ |
7997 | if (parent->groups == parent->groups->next) { | |
7998 | pflags &= ~(SD_LOAD_BALANCE | | |
7999 | SD_BALANCE_NEWIDLE | | |
8000 | SD_BALANCE_FORK | | |
89c4710e SS |
8001 | SD_BALANCE_EXEC | |
8002 | SD_SHARE_CPUPOWER | | |
8003 | SD_SHARE_PKG_RESOURCES); | |
5436499e KC |
8004 | if (nr_node_ids == 1) |
8005 | pflags &= ~SD_SERIALIZE; | |
245af2c7 SS |
8006 | } |
8007 | if (~cflags & pflags) | |
8008 | return 0; | |
8009 | ||
8010 | return 1; | |
8011 | } | |
8012 | ||
c6c4927b RR |
8013 | static void free_rootdomain(struct root_domain *rd) |
8014 | { | |
047106ad PZ |
8015 | synchronize_sched(); |
8016 | ||
68e74568 RR |
8017 | cpupri_cleanup(&rd->cpupri); |
8018 | ||
c6c4927b RR |
8019 | free_cpumask_var(rd->rto_mask); |
8020 | free_cpumask_var(rd->online); | |
8021 | free_cpumask_var(rd->span); | |
8022 | kfree(rd); | |
8023 | } | |
8024 | ||
57d885fe GH |
8025 | static void rq_attach_root(struct rq *rq, struct root_domain *rd) |
8026 | { | |
a0490fa3 | 8027 | struct root_domain *old_rd = NULL; |
57d885fe | 8028 | unsigned long flags; |
57d885fe | 8029 | |
05fa785c | 8030 | raw_spin_lock_irqsave(&rq->lock, flags); |
57d885fe GH |
8031 | |
8032 | if (rq->rd) { | |
a0490fa3 | 8033 | old_rd = rq->rd; |
57d885fe | 8034 | |
c6c4927b | 8035 | if (cpumask_test_cpu(rq->cpu, old_rd->online)) |
1f11eb6a | 8036 | set_rq_offline(rq); |
57d885fe | 8037 | |
c6c4927b | 8038 | cpumask_clear_cpu(rq->cpu, old_rd->span); |
dc938520 | 8039 | |
a0490fa3 IM |
8040 | /* |
8041 | * If we dont want to free the old_rt yet then | |
8042 | * set old_rd to NULL to skip the freeing later | |
8043 | * in this function: | |
8044 | */ | |
8045 | if (!atomic_dec_and_test(&old_rd->refcount)) | |
8046 | old_rd = NULL; | |
57d885fe GH |
8047 | } |
8048 | ||
8049 | atomic_inc(&rd->refcount); | |
8050 | rq->rd = rd; | |
8051 | ||
c6c4927b | 8052 | cpumask_set_cpu(rq->cpu, rd->span); |
00aec93d | 8053 | if (cpumask_test_cpu(rq->cpu, cpu_active_mask)) |
1f11eb6a | 8054 | set_rq_online(rq); |
57d885fe | 8055 | |
05fa785c | 8056 | raw_spin_unlock_irqrestore(&rq->lock, flags); |
a0490fa3 IM |
8057 | |
8058 | if (old_rd) | |
8059 | free_rootdomain(old_rd); | |
57d885fe GH |
8060 | } |
8061 | ||
fd5e1b5d | 8062 | static int init_rootdomain(struct root_domain *rd, bool bootmem) |
57d885fe | 8063 | { |
36b7b6d4 PE |
8064 | gfp_t gfp = GFP_KERNEL; |
8065 | ||
57d885fe GH |
8066 | memset(rd, 0, sizeof(*rd)); |
8067 | ||
36b7b6d4 PE |
8068 | if (bootmem) |
8069 | gfp = GFP_NOWAIT; | |
c6c4927b | 8070 | |
36b7b6d4 | 8071 | if (!alloc_cpumask_var(&rd->span, gfp)) |
0c910d28 | 8072 | goto out; |
36b7b6d4 | 8073 | if (!alloc_cpumask_var(&rd->online, gfp)) |
c6c4927b | 8074 | goto free_span; |
36b7b6d4 | 8075 | if (!alloc_cpumask_var(&rd->rto_mask, gfp)) |
c6c4927b | 8076 | goto free_online; |
6e0534f2 | 8077 | |
0fb53029 | 8078 | if (cpupri_init(&rd->cpupri, bootmem) != 0) |
68e74568 | 8079 | goto free_rto_mask; |
c6c4927b | 8080 | return 0; |
6e0534f2 | 8081 | |
68e74568 RR |
8082 | free_rto_mask: |
8083 | free_cpumask_var(rd->rto_mask); | |
c6c4927b RR |
8084 | free_online: |
8085 | free_cpumask_var(rd->online); | |
8086 | free_span: | |
8087 | free_cpumask_var(rd->span); | |
0c910d28 | 8088 | out: |
c6c4927b | 8089 | return -ENOMEM; |
57d885fe GH |
8090 | } |
8091 | ||
8092 | static void init_defrootdomain(void) | |
8093 | { | |
c6c4927b RR |
8094 | init_rootdomain(&def_root_domain, true); |
8095 | ||
57d885fe GH |
8096 | atomic_set(&def_root_domain.refcount, 1); |
8097 | } | |
8098 | ||
dc938520 | 8099 | static struct root_domain *alloc_rootdomain(void) |
57d885fe GH |
8100 | { |
8101 | struct root_domain *rd; | |
8102 | ||
8103 | rd = kmalloc(sizeof(*rd), GFP_KERNEL); | |
8104 | if (!rd) | |
8105 | return NULL; | |
8106 | ||
c6c4927b RR |
8107 | if (init_rootdomain(rd, false) != 0) { |
8108 | kfree(rd); | |
8109 | return NULL; | |
8110 | } | |
57d885fe GH |
8111 | |
8112 | return rd; | |
8113 | } | |
8114 | ||
1da177e4 | 8115 | /* |
0eab9146 | 8116 | * Attach the domain 'sd' to 'cpu' as its base domain. Callers must |
1da177e4 LT |
8117 | * hold the hotplug lock. |
8118 | */ | |
0eab9146 IM |
8119 | static void |
8120 | cpu_attach_domain(struct sched_domain *sd, struct root_domain *rd, int cpu) | |
1da177e4 | 8121 | { |
70b97a7f | 8122 | struct rq *rq = cpu_rq(cpu); |
245af2c7 SS |
8123 | struct sched_domain *tmp; |
8124 | ||
8125 | /* Remove the sched domains which do not contribute to scheduling. */ | |
f29c9b1c | 8126 | for (tmp = sd; tmp; ) { |
245af2c7 SS |
8127 | struct sched_domain *parent = tmp->parent; |
8128 | if (!parent) | |
8129 | break; | |
f29c9b1c | 8130 | |
1a848870 | 8131 | if (sd_parent_degenerate(tmp, parent)) { |
245af2c7 | 8132 | tmp->parent = parent->parent; |
1a848870 SS |
8133 | if (parent->parent) |
8134 | parent->parent->child = tmp; | |
f29c9b1c LZ |
8135 | } else |
8136 | tmp = tmp->parent; | |
245af2c7 SS |
8137 | } |
8138 | ||
1a848870 | 8139 | if (sd && sd_degenerate(sd)) { |
245af2c7 | 8140 | sd = sd->parent; |
1a848870 SS |
8141 | if (sd) |
8142 | sd->child = NULL; | |
8143 | } | |
1da177e4 LT |
8144 | |
8145 | sched_domain_debug(sd, cpu); | |
8146 | ||
57d885fe | 8147 | rq_attach_root(rq, rd); |
674311d5 | 8148 | rcu_assign_pointer(rq->sd, sd); |
1da177e4 LT |
8149 | } |
8150 | ||
8151 | /* cpus with isolated domains */ | |
dcc30a35 | 8152 | static cpumask_var_t cpu_isolated_map; |
1da177e4 LT |
8153 | |
8154 | /* Setup the mask of cpus configured for isolated domains */ | |
8155 | static int __init isolated_cpu_setup(char *str) | |
8156 | { | |
bdddd296 | 8157 | alloc_bootmem_cpumask_var(&cpu_isolated_map); |
968ea6d8 | 8158 | cpulist_parse(str, cpu_isolated_map); |
1da177e4 LT |
8159 | return 1; |
8160 | } | |
8161 | ||
8927f494 | 8162 | __setup("isolcpus=", isolated_cpu_setup); |
1da177e4 LT |
8163 | |
8164 | /* | |
6711cab4 SS |
8165 | * init_sched_build_groups takes the cpumask we wish to span, and a pointer |
8166 | * to a function which identifies what group(along with sched group) a CPU | |
96f874e2 RR |
8167 | * belongs to. The return value of group_fn must be a >= 0 and < nr_cpu_ids |
8168 | * (due to the fact that we keep track of groups covered with a struct cpumask). | |
1da177e4 LT |
8169 | * |
8170 | * init_sched_build_groups will build a circular linked list of the groups | |
8171 | * covered by the given span, and will set each group's ->cpumask correctly, | |
8172 | * and ->cpu_power to 0. | |
8173 | */ | |
a616058b | 8174 | static void |
96f874e2 RR |
8175 | init_sched_build_groups(const struct cpumask *span, |
8176 | const struct cpumask *cpu_map, | |
8177 | int (*group_fn)(int cpu, const struct cpumask *cpu_map, | |
7c16ec58 | 8178 | struct sched_group **sg, |
96f874e2 RR |
8179 | struct cpumask *tmpmask), |
8180 | struct cpumask *covered, struct cpumask *tmpmask) | |
1da177e4 LT |
8181 | { |
8182 | struct sched_group *first = NULL, *last = NULL; | |
1da177e4 LT |
8183 | int i; |
8184 | ||
96f874e2 | 8185 | cpumask_clear(covered); |
7c16ec58 | 8186 | |
abcd083a | 8187 | for_each_cpu(i, span) { |
6711cab4 | 8188 | struct sched_group *sg; |
7c16ec58 | 8189 | int group = group_fn(i, cpu_map, &sg, tmpmask); |
1da177e4 LT |
8190 | int j; |
8191 | ||
758b2cdc | 8192 | if (cpumask_test_cpu(i, covered)) |
1da177e4 LT |
8193 | continue; |
8194 | ||
758b2cdc | 8195 | cpumask_clear(sched_group_cpus(sg)); |
18a3885f | 8196 | sg->cpu_power = 0; |
1da177e4 | 8197 | |
abcd083a | 8198 | for_each_cpu(j, span) { |
7c16ec58 | 8199 | if (group_fn(j, cpu_map, NULL, tmpmask) != group) |
1da177e4 LT |
8200 | continue; |
8201 | ||
96f874e2 | 8202 | cpumask_set_cpu(j, covered); |
758b2cdc | 8203 | cpumask_set_cpu(j, sched_group_cpus(sg)); |
1da177e4 LT |
8204 | } |
8205 | if (!first) | |
8206 | first = sg; | |
8207 | if (last) | |
8208 | last->next = sg; | |
8209 | last = sg; | |
8210 | } | |
8211 | last->next = first; | |
8212 | } | |
8213 | ||
9c1cfda2 | 8214 | #define SD_NODES_PER_DOMAIN 16 |
1da177e4 | 8215 | |
9c1cfda2 | 8216 | #ifdef CONFIG_NUMA |
198e2f18 | 8217 | |
9c1cfda2 JH |
8218 | /** |
8219 | * find_next_best_node - find the next node to include in a sched_domain | |
8220 | * @node: node whose sched_domain we're building | |
8221 | * @used_nodes: nodes already in the sched_domain | |
8222 | * | |
41a2d6cf | 8223 | * Find the next node to include in a given scheduling domain. Simply |
9c1cfda2 JH |
8224 | * finds the closest node not already in the @used_nodes map. |
8225 | * | |
8226 | * Should use nodemask_t. | |
8227 | */ | |
c5f59f08 | 8228 | static int find_next_best_node(int node, nodemask_t *used_nodes) |
9c1cfda2 JH |
8229 | { |
8230 | int i, n, val, min_val, best_node = 0; | |
8231 | ||
8232 | min_val = INT_MAX; | |
8233 | ||
076ac2af | 8234 | for (i = 0; i < nr_node_ids; i++) { |
9c1cfda2 | 8235 | /* Start at @node */ |
076ac2af | 8236 | n = (node + i) % nr_node_ids; |
9c1cfda2 JH |
8237 | |
8238 | if (!nr_cpus_node(n)) | |
8239 | continue; | |
8240 | ||
8241 | /* Skip already used nodes */ | |
c5f59f08 | 8242 | if (node_isset(n, *used_nodes)) |
9c1cfda2 JH |
8243 | continue; |
8244 | ||
8245 | /* Simple min distance search */ | |
8246 | val = node_distance(node, n); | |
8247 | ||
8248 | if (val < min_val) { | |
8249 | min_val = val; | |
8250 | best_node = n; | |
8251 | } | |
8252 | } | |
8253 | ||
c5f59f08 | 8254 | node_set(best_node, *used_nodes); |
9c1cfda2 JH |
8255 | return best_node; |
8256 | } | |
8257 | ||
8258 | /** | |
8259 | * sched_domain_node_span - get a cpumask for a node's sched_domain | |
8260 | * @node: node whose cpumask we're constructing | |
73486722 | 8261 | * @span: resulting cpumask |
9c1cfda2 | 8262 | * |
41a2d6cf | 8263 | * Given a node, construct a good cpumask for its sched_domain to span. It |
9c1cfda2 JH |
8264 | * should be one that prevents unnecessary balancing, but also spreads tasks |
8265 | * out optimally. | |
8266 | */ | |
96f874e2 | 8267 | static void sched_domain_node_span(int node, struct cpumask *span) |
9c1cfda2 | 8268 | { |
c5f59f08 | 8269 | nodemask_t used_nodes; |
48f24c4d | 8270 | int i; |
9c1cfda2 | 8271 | |
6ca09dfc | 8272 | cpumask_clear(span); |
c5f59f08 | 8273 | nodes_clear(used_nodes); |
9c1cfda2 | 8274 | |
6ca09dfc | 8275 | cpumask_or(span, span, cpumask_of_node(node)); |
c5f59f08 | 8276 | node_set(node, used_nodes); |
9c1cfda2 JH |
8277 | |
8278 | for (i = 1; i < SD_NODES_PER_DOMAIN; i++) { | |
c5f59f08 | 8279 | int next_node = find_next_best_node(node, &used_nodes); |
48f24c4d | 8280 | |
6ca09dfc | 8281 | cpumask_or(span, span, cpumask_of_node(next_node)); |
9c1cfda2 | 8282 | } |
9c1cfda2 | 8283 | } |
6d6bc0ad | 8284 | #endif /* CONFIG_NUMA */ |
9c1cfda2 | 8285 | |
5c45bf27 | 8286 | int sched_smt_power_savings = 0, sched_mc_power_savings = 0; |
48f24c4d | 8287 | |
6c99e9ad RR |
8288 | /* |
8289 | * The cpus mask in sched_group and sched_domain hangs off the end. | |
4200efd9 IM |
8290 | * |
8291 | * ( See the the comments in include/linux/sched.h:struct sched_group | |
8292 | * and struct sched_domain. ) | |
6c99e9ad RR |
8293 | */ |
8294 | struct static_sched_group { | |
8295 | struct sched_group sg; | |
8296 | DECLARE_BITMAP(cpus, CONFIG_NR_CPUS); | |
8297 | }; | |
8298 | ||
8299 | struct static_sched_domain { | |
8300 | struct sched_domain sd; | |
8301 | DECLARE_BITMAP(span, CONFIG_NR_CPUS); | |
8302 | }; | |
8303 | ||
49a02c51 AH |
8304 | struct s_data { |
8305 | #ifdef CONFIG_NUMA | |
8306 | int sd_allnodes; | |
8307 | cpumask_var_t domainspan; | |
8308 | cpumask_var_t covered; | |
8309 | cpumask_var_t notcovered; | |
8310 | #endif | |
8311 | cpumask_var_t nodemask; | |
8312 | cpumask_var_t this_sibling_map; | |
8313 | cpumask_var_t this_core_map; | |
8314 | cpumask_var_t send_covered; | |
8315 | cpumask_var_t tmpmask; | |
8316 | struct sched_group **sched_group_nodes; | |
8317 | struct root_domain *rd; | |
8318 | }; | |
8319 | ||
2109b99e AH |
8320 | enum s_alloc { |
8321 | sa_sched_groups = 0, | |
8322 | sa_rootdomain, | |
8323 | sa_tmpmask, | |
8324 | sa_send_covered, | |
8325 | sa_this_core_map, | |
8326 | sa_this_sibling_map, | |
8327 | sa_nodemask, | |
8328 | sa_sched_group_nodes, | |
8329 | #ifdef CONFIG_NUMA | |
8330 | sa_notcovered, | |
8331 | sa_covered, | |
8332 | sa_domainspan, | |
8333 | #endif | |
8334 | sa_none, | |
8335 | }; | |
8336 | ||
9c1cfda2 | 8337 | /* |
48f24c4d | 8338 | * SMT sched-domains: |
9c1cfda2 | 8339 | */ |
1da177e4 | 8340 | #ifdef CONFIG_SCHED_SMT |
6c99e9ad | 8341 | static DEFINE_PER_CPU(struct static_sched_domain, cpu_domains); |
1871e52c | 8342 | static DEFINE_PER_CPU(struct static_sched_group, sched_groups); |
48f24c4d | 8343 | |
41a2d6cf | 8344 | static int |
96f874e2 RR |
8345 | cpu_to_cpu_group(int cpu, const struct cpumask *cpu_map, |
8346 | struct sched_group **sg, struct cpumask *unused) | |
1da177e4 | 8347 | { |
6711cab4 | 8348 | if (sg) |
1871e52c | 8349 | *sg = &per_cpu(sched_groups, cpu).sg; |
1da177e4 LT |
8350 | return cpu; |
8351 | } | |
6d6bc0ad | 8352 | #endif /* CONFIG_SCHED_SMT */ |
1da177e4 | 8353 | |
48f24c4d IM |
8354 | /* |
8355 | * multi-core sched-domains: | |
8356 | */ | |
1e9f28fa | 8357 | #ifdef CONFIG_SCHED_MC |
6c99e9ad RR |
8358 | static DEFINE_PER_CPU(struct static_sched_domain, core_domains); |
8359 | static DEFINE_PER_CPU(struct static_sched_group, sched_group_core); | |
6d6bc0ad | 8360 | #endif /* CONFIG_SCHED_MC */ |
1e9f28fa SS |
8361 | |
8362 | #if defined(CONFIG_SCHED_MC) && defined(CONFIG_SCHED_SMT) | |
41a2d6cf | 8363 | static int |
96f874e2 RR |
8364 | cpu_to_core_group(int cpu, const struct cpumask *cpu_map, |
8365 | struct sched_group **sg, struct cpumask *mask) | |
1e9f28fa | 8366 | { |
6711cab4 | 8367 | int group; |
7c16ec58 | 8368 | |
c69fc56d | 8369 | cpumask_and(mask, topology_thread_cpumask(cpu), cpu_map); |
96f874e2 | 8370 | group = cpumask_first(mask); |
6711cab4 | 8371 | if (sg) |
6c99e9ad | 8372 | *sg = &per_cpu(sched_group_core, group).sg; |
6711cab4 | 8373 | return group; |
1e9f28fa SS |
8374 | } |
8375 | #elif defined(CONFIG_SCHED_MC) | |
41a2d6cf | 8376 | static int |
96f874e2 RR |
8377 | cpu_to_core_group(int cpu, const struct cpumask *cpu_map, |
8378 | struct sched_group **sg, struct cpumask *unused) | |
1e9f28fa | 8379 | { |
6711cab4 | 8380 | if (sg) |
6c99e9ad | 8381 | *sg = &per_cpu(sched_group_core, cpu).sg; |
1e9f28fa SS |
8382 | return cpu; |
8383 | } | |
8384 | #endif | |
8385 | ||
6c99e9ad RR |
8386 | static DEFINE_PER_CPU(struct static_sched_domain, phys_domains); |
8387 | static DEFINE_PER_CPU(struct static_sched_group, sched_group_phys); | |
48f24c4d | 8388 | |
41a2d6cf | 8389 | static int |
96f874e2 RR |
8390 | cpu_to_phys_group(int cpu, const struct cpumask *cpu_map, |
8391 | struct sched_group **sg, struct cpumask *mask) | |
1da177e4 | 8392 | { |
6711cab4 | 8393 | int group; |
48f24c4d | 8394 | #ifdef CONFIG_SCHED_MC |
6ca09dfc | 8395 | cpumask_and(mask, cpu_coregroup_mask(cpu), cpu_map); |
96f874e2 | 8396 | group = cpumask_first(mask); |
1e9f28fa | 8397 | #elif defined(CONFIG_SCHED_SMT) |
c69fc56d | 8398 | cpumask_and(mask, topology_thread_cpumask(cpu), cpu_map); |
96f874e2 | 8399 | group = cpumask_first(mask); |
1da177e4 | 8400 | #else |
6711cab4 | 8401 | group = cpu; |
1da177e4 | 8402 | #endif |
6711cab4 | 8403 | if (sg) |
6c99e9ad | 8404 | *sg = &per_cpu(sched_group_phys, group).sg; |
6711cab4 | 8405 | return group; |
1da177e4 LT |
8406 | } |
8407 | ||
8408 | #ifdef CONFIG_NUMA | |
1da177e4 | 8409 | /* |
9c1cfda2 JH |
8410 | * The init_sched_build_groups can't handle what we want to do with node |
8411 | * groups, so roll our own. Now each node has its own list of groups which | |
8412 | * gets dynamically allocated. | |
1da177e4 | 8413 | */ |
62ea9ceb | 8414 | static DEFINE_PER_CPU(struct static_sched_domain, node_domains); |
434d53b0 | 8415 | static struct sched_group ***sched_group_nodes_bycpu; |
1da177e4 | 8416 | |
62ea9ceb | 8417 | static DEFINE_PER_CPU(struct static_sched_domain, allnodes_domains); |
6c99e9ad | 8418 | static DEFINE_PER_CPU(struct static_sched_group, sched_group_allnodes); |
9c1cfda2 | 8419 | |
96f874e2 RR |
8420 | static int cpu_to_allnodes_group(int cpu, const struct cpumask *cpu_map, |
8421 | struct sched_group **sg, | |
8422 | struct cpumask *nodemask) | |
9c1cfda2 | 8423 | { |
6711cab4 SS |
8424 | int group; |
8425 | ||
6ca09dfc | 8426 | cpumask_and(nodemask, cpumask_of_node(cpu_to_node(cpu)), cpu_map); |
96f874e2 | 8427 | group = cpumask_first(nodemask); |
6711cab4 SS |
8428 | |
8429 | if (sg) | |
6c99e9ad | 8430 | *sg = &per_cpu(sched_group_allnodes, group).sg; |
6711cab4 | 8431 | return group; |
1da177e4 | 8432 | } |
6711cab4 | 8433 | |
08069033 SS |
8434 | static void init_numa_sched_groups_power(struct sched_group *group_head) |
8435 | { | |
8436 | struct sched_group *sg = group_head; | |
8437 | int j; | |
8438 | ||
8439 | if (!sg) | |
8440 | return; | |
3a5c359a | 8441 | do { |
758b2cdc | 8442 | for_each_cpu(j, sched_group_cpus(sg)) { |
3a5c359a | 8443 | struct sched_domain *sd; |
08069033 | 8444 | |
6c99e9ad | 8445 | sd = &per_cpu(phys_domains, j).sd; |
13318a71 | 8446 | if (j != group_first_cpu(sd->groups)) { |
3a5c359a AK |
8447 | /* |
8448 | * Only add "power" once for each | |
8449 | * physical package. | |
8450 | */ | |
8451 | continue; | |
8452 | } | |
08069033 | 8453 | |
18a3885f | 8454 | sg->cpu_power += sd->groups->cpu_power; |
3a5c359a AK |
8455 | } |
8456 | sg = sg->next; | |
8457 | } while (sg != group_head); | |
08069033 | 8458 | } |
0601a88d AH |
8459 | |
8460 | static int build_numa_sched_groups(struct s_data *d, | |
8461 | const struct cpumask *cpu_map, int num) | |
8462 | { | |
8463 | struct sched_domain *sd; | |
8464 | struct sched_group *sg, *prev; | |
8465 | int n, j; | |
8466 | ||
8467 | cpumask_clear(d->covered); | |
8468 | cpumask_and(d->nodemask, cpumask_of_node(num), cpu_map); | |
8469 | if (cpumask_empty(d->nodemask)) { | |
8470 | d->sched_group_nodes[num] = NULL; | |
8471 | goto out; | |
8472 | } | |
8473 | ||
8474 | sched_domain_node_span(num, d->domainspan); | |
8475 | cpumask_and(d->domainspan, d->domainspan, cpu_map); | |
8476 | ||
8477 | sg = kmalloc_node(sizeof(struct sched_group) + cpumask_size(), | |
8478 | GFP_KERNEL, num); | |
8479 | if (!sg) { | |
3df0fc5b PZ |
8480 | printk(KERN_WARNING "Can not alloc domain group for node %d\n", |
8481 | num); | |
0601a88d AH |
8482 | return -ENOMEM; |
8483 | } | |
8484 | d->sched_group_nodes[num] = sg; | |
8485 | ||
8486 | for_each_cpu(j, d->nodemask) { | |
8487 | sd = &per_cpu(node_domains, j).sd; | |
8488 | sd->groups = sg; | |
8489 | } | |
8490 | ||
18a3885f | 8491 | sg->cpu_power = 0; |
0601a88d AH |
8492 | cpumask_copy(sched_group_cpus(sg), d->nodemask); |
8493 | sg->next = sg; | |
8494 | cpumask_or(d->covered, d->covered, d->nodemask); | |
8495 | ||
8496 | prev = sg; | |
8497 | for (j = 0; j < nr_node_ids; j++) { | |
8498 | n = (num + j) % nr_node_ids; | |
8499 | cpumask_complement(d->notcovered, d->covered); | |
8500 | cpumask_and(d->tmpmask, d->notcovered, cpu_map); | |
8501 | cpumask_and(d->tmpmask, d->tmpmask, d->domainspan); | |
8502 | if (cpumask_empty(d->tmpmask)) | |
8503 | break; | |
8504 | cpumask_and(d->tmpmask, d->tmpmask, cpumask_of_node(n)); | |
8505 | if (cpumask_empty(d->tmpmask)) | |
8506 | continue; | |
8507 | sg = kmalloc_node(sizeof(struct sched_group) + cpumask_size(), | |
8508 | GFP_KERNEL, num); | |
8509 | if (!sg) { | |
3df0fc5b PZ |
8510 | printk(KERN_WARNING |
8511 | "Can not alloc domain group for node %d\n", j); | |
0601a88d AH |
8512 | return -ENOMEM; |
8513 | } | |
18a3885f | 8514 | sg->cpu_power = 0; |
0601a88d AH |
8515 | cpumask_copy(sched_group_cpus(sg), d->tmpmask); |
8516 | sg->next = prev->next; | |
8517 | cpumask_or(d->covered, d->covered, d->tmpmask); | |
8518 | prev->next = sg; | |
8519 | prev = sg; | |
8520 | } | |
8521 | out: | |
8522 | return 0; | |
8523 | } | |
6d6bc0ad | 8524 | #endif /* CONFIG_NUMA */ |
1da177e4 | 8525 | |
a616058b | 8526 | #ifdef CONFIG_NUMA |
51888ca2 | 8527 | /* Free memory allocated for various sched_group structures */ |
96f874e2 RR |
8528 | static void free_sched_groups(const struct cpumask *cpu_map, |
8529 | struct cpumask *nodemask) | |
51888ca2 | 8530 | { |
a616058b | 8531 | int cpu, i; |
51888ca2 | 8532 | |
abcd083a | 8533 | for_each_cpu(cpu, cpu_map) { |
51888ca2 SV |
8534 | struct sched_group **sched_group_nodes |
8535 | = sched_group_nodes_bycpu[cpu]; | |
8536 | ||
51888ca2 SV |
8537 | if (!sched_group_nodes) |
8538 | continue; | |
8539 | ||
076ac2af | 8540 | for (i = 0; i < nr_node_ids; i++) { |
51888ca2 SV |
8541 | struct sched_group *oldsg, *sg = sched_group_nodes[i]; |
8542 | ||
6ca09dfc | 8543 | cpumask_and(nodemask, cpumask_of_node(i), cpu_map); |
96f874e2 | 8544 | if (cpumask_empty(nodemask)) |
51888ca2 SV |
8545 | continue; |
8546 | ||
8547 | if (sg == NULL) | |
8548 | continue; | |
8549 | sg = sg->next; | |
8550 | next_sg: | |
8551 | oldsg = sg; | |
8552 | sg = sg->next; | |
8553 | kfree(oldsg); | |
8554 | if (oldsg != sched_group_nodes[i]) | |
8555 | goto next_sg; | |
8556 | } | |
8557 | kfree(sched_group_nodes); | |
8558 | sched_group_nodes_bycpu[cpu] = NULL; | |
8559 | } | |
51888ca2 | 8560 | } |
6d6bc0ad | 8561 | #else /* !CONFIG_NUMA */ |
96f874e2 RR |
8562 | static void free_sched_groups(const struct cpumask *cpu_map, |
8563 | struct cpumask *nodemask) | |
a616058b SS |
8564 | { |
8565 | } | |
6d6bc0ad | 8566 | #endif /* CONFIG_NUMA */ |
51888ca2 | 8567 | |
89c4710e SS |
8568 | /* |
8569 | * Initialize sched groups cpu_power. | |
8570 | * | |
8571 | * cpu_power indicates the capacity of sched group, which is used while | |
8572 | * distributing the load between different sched groups in a sched domain. | |
8573 | * Typically cpu_power for all the groups in a sched domain will be same unless | |
8574 | * there are asymmetries in the topology. If there are asymmetries, group | |
8575 | * having more cpu_power will pickup more load compared to the group having | |
8576 | * less cpu_power. | |
89c4710e SS |
8577 | */ |
8578 | static void init_sched_groups_power(int cpu, struct sched_domain *sd) | |
8579 | { | |
8580 | struct sched_domain *child; | |
8581 | struct sched_group *group; | |
f93e65c1 PZ |
8582 | long power; |
8583 | int weight; | |
89c4710e SS |
8584 | |
8585 | WARN_ON(!sd || !sd->groups); | |
8586 | ||
13318a71 | 8587 | if (cpu != group_first_cpu(sd->groups)) |
89c4710e SS |
8588 | return; |
8589 | ||
8590 | child = sd->child; | |
8591 | ||
18a3885f | 8592 | sd->groups->cpu_power = 0; |
5517d86b | 8593 | |
f93e65c1 PZ |
8594 | if (!child) { |
8595 | power = SCHED_LOAD_SCALE; | |
8596 | weight = cpumask_weight(sched_domain_span(sd)); | |
8597 | /* | |
8598 | * SMT siblings share the power of a single core. | |
a52bfd73 PZ |
8599 | * Usually multiple threads get a better yield out of |
8600 | * that one core than a single thread would have, | |
8601 | * reflect that in sd->smt_gain. | |
f93e65c1 | 8602 | */ |
a52bfd73 PZ |
8603 | if ((sd->flags & SD_SHARE_CPUPOWER) && weight > 1) { |
8604 | power *= sd->smt_gain; | |
f93e65c1 | 8605 | power /= weight; |
a52bfd73 PZ |
8606 | power >>= SCHED_LOAD_SHIFT; |
8607 | } | |
18a3885f | 8608 | sd->groups->cpu_power += power; |
89c4710e SS |
8609 | return; |
8610 | } | |
8611 | ||
89c4710e | 8612 | /* |
f93e65c1 | 8613 | * Add cpu_power of each child group to this groups cpu_power. |
89c4710e SS |
8614 | */ |
8615 | group = child->groups; | |
8616 | do { | |
18a3885f | 8617 | sd->groups->cpu_power += group->cpu_power; |
89c4710e SS |
8618 | group = group->next; |
8619 | } while (group != child->groups); | |
8620 | } | |
8621 | ||
7c16ec58 MT |
8622 | /* |
8623 | * Initializers for schedule domains | |
8624 | * Non-inlined to reduce accumulated stack pressure in build_sched_domains() | |
8625 | */ | |
8626 | ||
a5d8c348 IM |
8627 | #ifdef CONFIG_SCHED_DEBUG |
8628 | # define SD_INIT_NAME(sd, type) sd->name = #type | |
8629 | #else | |
8630 | # define SD_INIT_NAME(sd, type) do { } while (0) | |
8631 | #endif | |
8632 | ||
7c16ec58 | 8633 | #define SD_INIT(sd, type) sd_init_##type(sd) |
a5d8c348 | 8634 | |
7c16ec58 MT |
8635 | #define SD_INIT_FUNC(type) \ |
8636 | static noinline void sd_init_##type(struct sched_domain *sd) \ | |
8637 | { \ | |
8638 | memset(sd, 0, sizeof(*sd)); \ | |
8639 | *sd = SD_##type##_INIT; \ | |
1d3504fc | 8640 | sd->level = SD_LV_##type; \ |
a5d8c348 | 8641 | SD_INIT_NAME(sd, type); \ |
7c16ec58 MT |
8642 | } |
8643 | ||
8644 | SD_INIT_FUNC(CPU) | |
8645 | #ifdef CONFIG_NUMA | |
8646 | SD_INIT_FUNC(ALLNODES) | |
8647 | SD_INIT_FUNC(NODE) | |
8648 | #endif | |
8649 | #ifdef CONFIG_SCHED_SMT | |
8650 | SD_INIT_FUNC(SIBLING) | |
8651 | #endif | |
8652 | #ifdef CONFIG_SCHED_MC | |
8653 | SD_INIT_FUNC(MC) | |
8654 | #endif | |
8655 | ||
1d3504fc HS |
8656 | static int default_relax_domain_level = -1; |
8657 | ||
8658 | static int __init setup_relax_domain_level(char *str) | |
8659 | { | |
30e0e178 LZ |
8660 | unsigned long val; |
8661 | ||
8662 | val = simple_strtoul(str, NULL, 0); | |
8663 | if (val < SD_LV_MAX) | |
8664 | default_relax_domain_level = val; | |
8665 | ||
1d3504fc HS |
8666 | return 1; |
8667 | } | |
8668 | __setup("relax_domain_level=", setup_relax_domain_level); | |
8669 | ||
8670 | static void set_domain_attribute(struct sched_domain *sd, | |
8671 | struct sched_domain_attr *attr) | |
8672 | { | |
8673 | int request; | |
8674 | ||
8675 | if (!attr || attr->relax_domain_level < 0) { | |
8676 | if (default_relax_domain_level < 0) | |
8677 | return; | |
8678 | else | |
8679 | request = default_relax_domain_level; | |
8680 | } else | |
8681 | request = attr->relax_domain_level; | |
8682 | if (request < sd->level) { | |
8683 | /* turn off idle balance on this domain */ | |
c88d5910 | 8684 | sd->flags &= ~(SD_BALANCE_WAKE|SD_BALANCE_NEWIDLE); |
1d3504fc HS |
8685 | } else { |
8686 | /* turn on idle balance on this domain */ | |
c88d5910 | 8687 | sd->flags |= (SD_BALANCE_WAKE|SD_BALANCE_NEWIDLE); |
1d3504fc HS |
8688 | } |
8689 | } | |
8690 | ||
2109b99e AH |
8691 | static void __free_domain_allocs(struct s_data *d, enum s_alloc what, |
8692 | const struct cpumask *cpu_map) | |
8693 | { | |
8694 | switch (what) { | |
8695 | case sa_sched_groups: | |
8696 | free_sched_groups(cpu_map, d->tmpmask); /* fall through */ | |
8697 | d->sched_group_nodes = NULL; | |
8698 | case sa_rootdomain: | |
8699 | free_rootdomain(d->rd); /* fall through */ | |
8700 | case sa_tmpmask: | |
8701 | free_cpumask_var(d->tmpmask); /* fall through */ | |
8702 | case sa_send_covered: | |
8703 | free_cpumask_var(d->send_covered); /* fall through */ | |
8704 | case sa_this_core_map: | |
8705 | free_cpumask_var(d->this_core_map); /* fall through */ | |
8706 | case sa_this_sibling_map: | |
8707 | free_cpumask_var(d->this_sibling_map); /* fall through */ | |
8708 | case sa_nodemask: | |
8709 | free_cpumask_var(d->nodemask); /* fall through */ | |
8710 | case sa_sched_group_nodes: | |
d1b55138 | 8711 | #ifdef CONFIG_NUMA |
2109b99e AH |
8712 | kfree(d->sched_group_nodes); /* fall through */ |
8713 | case sa_notcovered: | |
8714 | free_cpumask_var(d->notcovered); /* fall through */ | |
8715 | case sa_covered: | |
8716 | free_cpumask_var(d->covered); /* fall through */ | |
8717 | case sa_domainspan: | |
8718 | free_cpumask_var(d->domainspan); /* fall through */ | |
3404c8d9 | 8719 | #endif |
2109b99e AH |
8720 | case sa_none: |
8721 | break; | |
8722 | } | |
8723 | } | |
3404c8d9 | 8724 | |
2109b99e AH |
8725 | static enum s_alloc __visit_domain_allocation_hell(struct s_data *d, |
8726 | const struct cpumask *cpu_map) | |
8727 | { | |
3404c8d9 | 8728 | #ifdef CONFIG_NUMA |
2109b99e AH |
8729 | if (!alloc_cpumask_var(&d->domainspan, GFP_KERNEL)) |
8730 | return sa_none; | |
8731 | if (!alloc_cpumask_var(&d->covered, GFP_KERNEL)) | |
8732 | return sa_domainspan; | |
8733 | if (!alloc_cpumask_var(&d->notcovered, GFP_KERNEL)) | |
8734 | return sa_covered; | |
8735 | /* Allocate the per-node list of sched groups */ | |
8736 | d->sched_group_nodes = kcalloc(nr_node_ids, | |
8737 | sizeof(struct sched_group *), GFP_KERNEL); | |
8738 | if (!d->sched_group_nodes) { | |
3df0fc5b | 8739 | printk(KERN_WARNING "Can not alloc sched group node list\n"); |
2109b99e | 8740 | return sa_notcovered; |
d1b55138 | 8741 | } |
2109b99e | 8742 | sched_group_nodes_bycpu[cpumask_first(cpu_map)] = d->sched_group_nodes; |
d1b55138 | 8743 | #endif |
2109b99e AH |
8744 | if (!alloc_cpumask_var(&d->nodemask, GFP_KERNEL)) |
8745 | return sa_sched_group_nodes; | |
8746 | if (!alloc_cpumask_var(&d->this_sibling_map, GFP_KERNEL)) | |
8747 | return sa_nodemask; | |
8748 | if (!alloc_cpumask_var(&d->this_core_map, GFP_KERNEL)) | |
8749 | return sa_this_sibling_map; | |
8750 | if (!alloc_cpumask_var(&d->send_covered, GFP_KERNEL)) | |
8751 | return sa_this_core_map; | |
8752 | if (!alloc_cpumask_var(&d->tmpmask, GFP_KERNEL)) | |
8753 | return sa_send_covered; | |
8754 | d->rd = alloc_rootdomain(); | |
8755 | if (!d->rd) { | |
3df0fc5b | 8756 | printk(KERN_WARNING "Cannot alloc root domain\n"); |
2109b99e | 8757 | return sa_tmpmask; |
57d885fe | 8758 | } |
2109b99e AH |
8759 | return sa_rootdomain; |
8760 | } | |
57d885fe | 8761 | |
7f4588f3 AH |
8762 | static struct sched_domain *__build_numa_sched_domains(struct s_data *d, |
8763 | const struct cpumask *cpu_map, struct sched_domain_attr *attr, int i) | |
8764 | { | |
8765 | struct sched_domain *sd = NULL; | |
7c16ec58 | 8766 | #ifdef CONFIG_NUMA |
7f4588f3 | 8767 | struct sched_domain *parent; |
1da177e4 | 8768 | |
7f4588f3 AH |
8769 | d->sd_allnodes = 0; |
8770 | if (cpumask_weight(cpu_map) > | |
8771 | SD_NODES_PER_DOMAIN * cpumask_weight(d->nodemask)) { | |
8772 | sd = &per_cpu(allnodes_domains, i).sd; | |
8773 | SD_INIT(sd, ALLNODES); | |
1d3504fc | 8774 | set_domain_attribute(sd, attr); |
7f4588f3 AH |
8775 | cpumask_copy(sched_domain_span(sd), cpu_map); |
8776 | cpu_to_allnodes_group(i, cpu_map, &sd->groups, d->tmpmask); | |
8777 | d->sd_allnodes = 1; | |
8778 | } | |
8779 | parent = sd; | |
8780 | ||
8781 | sd = &per_cpu(node_domains, i).sd; | |
8782 | SD_INIT(sd, NODE); | |
8783 | set_domain_attribute(sd, attr); | |
8784 | sched_domain_node_span(cpu_to_node(i), sched_domain_span(sd)); | |
8785 | sd->parent = parent; | |
8786 | if (parent) | |
8787 | parent->child = sd; | |
8788 | cpumask_and(sched_domain_span(sd), sched_domain_span(sd), cpu_map); | |
1da177e4 | 8789 | #endif |
7f4588f3 AH |
8790 | return sd; |
8791 | } | |
1da177e4 | 8792 | |
87cce662 AH |
8793 | static struct sched_domain *__build_cpu_sched_domain(struct s_data *d, |
8794 | const struct cpumask *cpu_map, struct sched_domain_attr *attr, | |
8795 | struct sched_domain *parent, int i) | |
8796 | { | |
8797 | struct sched_domain *sd; | |
8798 | sd = &per_cpu(phys_domains, i).sd; | |
8799 | SD_INIT(sd, CPU); | |
8800 | set_domain_attribute(sd, attr); | |
8801 | cpumask_copy(sched_domain_span(sd), d->nodemask); | |
8802 | sd->parent = parent; | |
8803 | if (parent) | |
8804 | parent->child = sd; | |
8805 | cpu_to_phys_group(i, cpu_map, &sd->groups, d->tmpmask); | |
8806 | return sd; | |
8807 | } | |
1da177e4 | 8808 | |
410c4081 AH |
8809 | static struct sched_domain *__build_mc_sched_domain(struct s_data *d, |
8810 | const struct cpumask *cpu_map, struct sched_domain_attr *attr, | |
8811 | struct sched_domain *parent, int i) | |
8812 | { | |
8813 | struct sched_domain *sd = parent; | |
1e9f28fa | 8814 | #ifdef CONFIG_SCHED_MC |
410c4081 AH |
8815 | sd = &per_cpu(core_domains, i).sd; |
8816 | SD_INIT(sd, MC); | |
8817 | set_domain_attribute(sd, attr); | |
8818 | cpumask_and(sched_domain_span(sd), cpu_map, cpu_coregroup_mask(i)); | |
8819 | sd->parent = parent; | |
8820 | parent->child = sd; | |
8821 | cpu_to_core_group(i, cpu_map, &sd->groups, d->tmpmask); | |
1e9f28fa | 8822 | #endif |
410c4081 AH |
8823 | return sd; |
8824 | } | |
1e9f28fa | 8825 | |
d8173535 AH |
8826 | static struct sched_domain *__build_smt_sched_domain(struct s_data *d, |
8827 | const struct cpumask *cpu_map, struct sched_domain_attr *attr, | |
8828 | struct sched_domain *parent, int i) | |
8829 | { | |
8830 | struct sched_domain *sd = parent; | |
1da177e4 | 8831 | #ifdef CONFIG_SCHED_SMT |
d8173535 AH |
8832 | sd = &per_cpu(cpu_domains, i).sd; |
8833 | SD_INIT(sd, SIBLING); | |
8834 | set_domain_attribute(sd, attr); | |
8835 | cpumask_and(sched_domain_span(sd), cpu_map, topology_thread_cpumask(i)); | |
8836 | sd->parent = parent; | |
8837 | parent->child = sd; | |
8838 | cpu_to_cpu_group(i, cpu_map, &sd->groups, d->tmpmask); | |
1da177e4 | 8839 | #endif |
d8173535 AH |
8840 | return sd; |
8841 | } | |
1da177e4 | 8842 | |
0e8e85c9 AH |
8843 | static void build_sched_groups(struct s_data *d, enum sched_domain_level l, |
8844 | const struct cpumask *cpu_map, int cpu) | |
8845 | { | |
8846 | switch (l) { | |
1da177e4 | 8847 | #ifdef CONFIG_SCHED_SMT |
0e8e85c9 AH |
8848 | case SD_LV_SIBLING: /* set up CPU (sibling) groups */ |
8849 | cpumask_and(d->this_sibling_map, cpu_map, | |
8850 | topology_thread_cpumask(cpu)); | |
8851 | if (cpu == cpumask_first(d->this_sibling_map)) | |
8852 | init_sched_build_groups(d->this_sibling_map, cpu_map, | |
8853 | &cpu_to_cpu_group, | |
8854 | d->send_covered, d->tmpmask); | |
8855 | break; | |
1da177e4 | 8856 | #endif |
1e9f28fa | 8857 | #ifdef CONFIG_SCHED_MC |
a2af04cd AH |
8858 | case SD_LV_MC: /* set up multi-core groups */ |
8859 | cpumask_and(d->this_core_map, cpu_map, cpu_coregroup_mask(cpu)); | |
8860 | if (cpu == cpumask_first(d->this_core_map)) | |
8861 | init_sched_build_groups(d->this_core_map, cpu_map, | |
8862 | &cpu_to_core_group, | |
8863 | d->send_covered, d->tmpmask); | |
8864 | break; | |
1e9f28fa | 8865 | #endif |
86548096 AH |
8866 | case SD_LV_CPU: /* set up physical groups */ |
8867 | cpumask_and(d->nodemask, cpumask_of_node(cpu), cpu_map); | |
8868 | if (!cpumask_empty(d->nodemask)) | |
8869 | init_sched_build_groups(d->nodemask, cpu_map, | |
8870 | &cpu_to_phys_group, | |
8871 | d->send_covered, d->tmpmask); | |
8872 | break; | |
1da177e4 | 8873 | #ifdef CONFIG_NUMA |
de616e36 AH |
8874 | case SD_LV_ALLNODES: |
8875 | init_sched_build_groups(cpu_map, cpu_map, &cpu_to_allnodes_group, | |
8876 | d->send_covered, d->tmpmask); | |
8877 | break; | |
8878 | #endif | |
0e8e85c9 AH |
8879 | default: |
8880 | break; | |
7c16ec58 | 8881 | } |
0e8e85c9 | 8882 | } |
9c1cfda2 | 8883 | |
2109b99e AH |
8884 | /* |
8885 | * Build sched domains for a given set of cpus and attach the sched domains | |
8886 | * to the individual cpus | |
8887 | */ | |
8888 | static int __build_sched_domains(const struct cpumask *cpu_map, | |
8889 | struct sched_domain_attr *attr) | |
8890 | { | |
8891 | enum s_alloc alloc_state = sa_none; | |
8892 | struct s_data d; | |
294b0c96 | 8893 | struct sched_domain *sd; |
2109b99e | 8894 | int i; |
7c16ec58 | 8895 | #ifdef CONFIG_NUMA |
2109b99e | 8896 | d.sd_allnodes = 0; |
7c16ec58 | 8897 | #endif |
9c1cfda2 | 8898 | |
2109b99e AH |
8899 | alloc_state = __visit_domain_allocation_hell(&d, cpu_map); |
8900 | if (alloc_state != sa_rootdomain) | |
8901 | goto error; | |
8902 | alloc_state = sa_sched_groups; | |
9c1cfda2 | 8903 | |
1da177e4 | 8904 | /* |
1a20ff27 | 8905 | * Set up domains for cpus specified by the cpu_map. |
1da177e4 | 8906 | */ |
abcd083a | 8907 | for_each_cpu(i, cpu_map) { |
49a02c51 AH |
8908 | cpumask_and(d.nodemask, cpumask_of_node(cpu_to_node(i)), |
8909 | cpu_map); | |
9761eea8 | 8910 | |
7f4588f3 | 8911 | sd = __build_numa_sched_domains(&d, cpu_map, attr, i); |
87cce662 | 8912 | sd = __build_cpu_sched_domain(&d, cpu_map, attr, sd, i); |
410c4081 | 8913 | sd = __build_mc_sched_domain(&d, cpu_map, attr, sd, i); |
d8173535 | 8914 | sd = __build_smt_sched_domain(&d, cpu_map, attr, sd, i); |
1da177e4 | 8915 | } |
9c1cfda2 | 8916 | |
abcd083a | 8917 | for_each_cpu(i, cpu_map) { |
0e8e85c9 | 8918 | build_sched_groups(&d, SD_LV_SIBLING, cpu_map, i); |
a2af04cd | 8919 | build_sched_groups(&d, SD_LV_MC, cpu_map, i); |
1da177e4 | 8920 | } |
9c1cfda2 | 8921 | |
1da177e4 | 8922 | /* Set up physical groups */ |
86548096 AH |
8923 | for (i = 0; i < nr_node_ids; i++) |
8924 | build_sched_groups(&d, SD_LV_CPU, cpu_map, i); | |
9c1cfda2 | 8925 | |
1da177e4 LT |
8926 | #ifdef CONFIG_NUMA |
8927 | /* Set up node groups */ | |
de616e36 AH |
8928 | if (d.sd_allnodes) |
8929 | build_sched_groups(&d, SD_LV_ALLNODES, cpu_map, 0); | |
9c1cfda2 | 8930 | |
0601a88d AH |
8931 | for (i = 0; i < nr_node_ids; i++) |
8932 | if (build_numa_sched_groups(&d, cpu_map, i)) | |
51888ca2 | 8933 | goto error; |
1da177e4 LT |
8934 | #endif |
8935 | ||
8936 | /* Calculate CPU power for physical packages and nodes */ | |
5c45bf27 | 8937 | #ifdef CONFIG_SCHED_SMT |
abcd083a | 8938 | for_each_cpu(i, cpu_map) { |
294b0c96 | 8939 | sd = &per_cpu(cpu_domains, i).sd; |
89c4710e | 8940 | init_sched_groups_power(i, sd); |
5c45bf27 | 8941 | } |
1da177e4 | 8942 | #endif |
1e9f28fa | 8943 | #ifdef CONFIG_SCHED_MC |
abcd083a | 8944 | for_each_cpu(i, cpu_map) { |
294b0c96 | 8945 | sd = &per_cpu(core_domains, i).sd; |
89c4710e | 8946 | init_sched_groups_power(i, sd); |
5c45bf27 SS |
8947 | } |
8948 | #endif | |
1e9f28fa | 8949 | |
abcd083a | 8950 | for_each_cpu(i, cpu_map) { |
294b0c96 | 8951 | sd = &per_cpu(phys_domains, i).sd; |
89c4710e | 8952 | init_sched_groups_power(i, sd); |
1da177e4 LT |
8953 | } |
8954 | ||
9c1cfda2 | 8955 | #ifdef CONFIG_NUMA |
076ac2af | 8956 | for (i = 0; i < nr_node_ids; i++) |
49a02c51 | 8957 | init_numa_sched_groups_power(d.sched_group_nodes[i]); |
9c1cfda2 | 8958 | |
49a02c51 | 8959 | if (d.sd_allnodes) { |
6711cab4 | 8960 | struct sched_group *sg; |
f712c0c7 | 8961 | |
96f874e2 | 8962 | cpu_to_allnodes_group(cpumask_first(cpu_map), cpu_map, &sg, |
49a02c51 | 8963 | d.tmpmask); |
f712c0c7 SS |
8964 | init_numa_sched_groups_power(sg); |
8965 | } | |
9c1cfda2 JH |
8966 | #endif |
8967 | ||
1da177e4 | 8968 | /* Attach the domains */ |
abcd083a | 8969 | for_each_cpu(i, cpu_map) { |
1da177e4 | 8970 | #ifdef CONFIG_SCHED_SMT |
6c99e9ad | 8971 | sd = &per_cpu(cpu_domains, i).sd; |
1e9f28fa | 8972 | #elif defined(CONFIG_SCHED_MC) |
6c99e9ad | 8973 | sd = &per_cpu(core_domains, i).sd; |
1da177e4 | 8974 | #else |
6c99e9ad | 8975 | sd = &per_cpu(phys_domains, i).sd; |
1da177e4 | 8976 | #endif |
49a02c51 | 8977 | cpu_attach_domain(sd, d.rd, i); |
1da177e4 | 8978 | } |
51888ca2 | 8979 | |
2109b99e AH |
8980 | d.sched_group_nodes = NULL; /* don't free this we still need it */ |
8981 | __free_domain_allocs(&d, sa_tmpmask, cpu_map); | |
8982 | return 0; | |
51888ca2 | 8983 | |
51888ca2 | 8984 | error: |
2109b99e AH |
8985 | __free_domain_allocs(&d, alloc_state, cpu_map); |
8986 | return -ENOMEM; | |
1da177e4 | 8987 | } |
029190c5 | 8988 | |
96f874e2 | 8989 | static int build_sched_domains(const struct cpumask *cpu_map) |
1d3504fc HS |
8990 | { |
8991 | return __build_sched_domains(cpu_map, NULL); | |
8992 | } | |
8993 | ||
acc3f5d7 | 8994 | static cpumask_var_t *doms_cur; /* current sched domains */ |
029190c5 | 8995 | static int ndoms_cur; /* number of sched domains in 'doms_cur' */ |
4285f594 IM |
8996 | static struct sched_domain_attr *dattr_cur; |
8997 | /* attribues of custom domains in 'doms_cur' */ | |
029190c5 PJ |
8998 | |
8999 | /* | |
9000 | * Special case: If a kmalloc of a doms_cur partition (array of | |
4212823f RR |
9001 | * cpumask) fails, then fallback to a single sched domain, |
9002 | * as determined by the single cpumask fallback_doms. | |
029190c5 | 9003 | */ |
4212823f | 9004 | static cpumask_var_t fallback_doms; |
029190c5 | 9005 | |
ee79d1bd HC |
9006 | /* |
9007 | * arch_update_cpu_topology lets virtualized architectures update the | |
9008 | * cpu core maps. It is supposed to return 1 if the topology changed | |
9009 | * or 0 if it stayed the same. | |
9010 | */ | |
9011 | int __attribute__((weak)) arch_update_cpu_topology(void) | |
22e52b07 | 9012 | { |
ee79d1bd | 9013 | return 0; |
22e52b07 HC |
9014 | } |
9015 | ||
acc3f5d7 RR |
9016 | cpumask_var_t *alloc_sched_domains(unsigned int ndoms) |
9017 | { | |
9018 | int i; | |
9019 | cpumask_var_t *doms; | |
9020 | ||
9021 | doms = kmalloc(sizeof(*doms) * ndoms, GFP_KERNEL); | |
9022 | if (!doms) | |
9023 | return NULL; | |
9024 | for (i = 0; i < ndoms; i++) { | |
9025 | if (!alloc_cpumask_var(&doms[i], GFP_KERNEL)) { | |
9026 | free_sched_domains(doms, i); | |
9027 | return NULL; | |
9028 | } | |
9029 | } | |
9030 | return doms; | |
9031 | } | |
9032 | ||
9033 | void free_sched_domains(cpumask_var_t doms[], unsigned int ndoms) | |
9034 | { | |
9035 | unsigned int i; | |
9036 | for (i = 0; i < ndoms; i++) | |
9037 | free_cpumask_var(doms[i]); | |
9038 | kfree(doms); | |
9039 | } | |
9040 | ||
1a20ff27 | 9041 | /* |
41a2d6cf | 9042 | * Set up scheduler domains and groups. Callers must hold the hotplug lock. |
029190c5 PJ |
9043 | * For now this just excludes isolated cpus, but could be used to |
9044 | * exclude other special cases in the future. | |
1a20ff27 | 9045 | */ |
96f874e2 | 9046 | static int arch_init_sched_domains(const struct cpumask *cpu_map) |
1a20ff27 | 9047 | { |
7378547f MM |
9048 | int err; |
9049 | ||
22e52b07 | 9050 | arch_update_cpu_topology(); |
029190c5 | 9051 | ndoms_cur = 1; |
acc3f5d7 | 9052 | doms_cur = alloc_sched_domains(ndoms_cur); |
029190c5 | 9053 | if (!doms_cur) |
acc3f5d7 RR |
9054 | doms_cur = &fallback_doms; |
9055 | cpumask_andnot(doms_cur[0], cpu_map, cpu_isolated_map); | |
1d3504fc | 9056 | dattr_cur = NULL; |
acc3f5d7 | 9057 | err = build_sched_domains(doms_cur[0]); |
6382bc90 | 9058 | register_sched_domain_sysctl(); |
7378547f MM |
9059 | |
9060 | return err; | |
1a20ff27 DG |
9061 | } |
9062 | ||
96f874e2 RR |
9063 | static void arch_destroy_sched_domains(const struct cpumask *cpu_map, |
9064 | struct cpumask *tmpmask) | |
1da177e4 | 9065 | { |
7c16ec58 | 9066 | free_sched_groups(cpu_map, tmpmask); |
9c1cfda2 | 9067 | } |
1da177e4 | 9068 | |
1a20ff27 DG |
9069 | /* |
9070 | * Detach sched domains from a group of cpus specified in cpu_map | |
9071 | * These cpus will now be attached to the NULL domain | |
9072 | */ | |
96f874e2 | 9073 | static void detach_destroy_domains(const struct cpumask *cpu_map) |
1a20ff27 | 9074 | { |
96f874e2 RR |
9075 | /* Save because hotplug lock held. */ |
9076 | static DECLARE_BITMAP(tmpmask, CONFIG_NR_CPUS); | |
1a20ff27 DG |
9077 | int i; |
9078 | ||
abcd083a | 9079 | for_each_cpu(i, cpu_map) |
57d885fe | 9080 | cpu_attach_domain(NULL, &def_root_domain, i); |
1a20ff27 | 9081 | synchronize_sched(); |
96f874e2 | 9082 | arch_destroy_sched_domains(cpu_map, to_cpumask(tmpmask)); |
1a20ff27 DG |
9083 | } |
9084 | ||
1d3504fc HS |
9085 | /* handle null as "default" */ |
9086 | static int dattrs_equal(struct sched_domain_attr *cur, int idx_cur, | |
9087 | struct sched_domain_attr *new, int idx_new) | |
9088 | { | |
9089 | struct sched_domain_attr tmp; | |
9090 | ||
9091 | /* fast path */ | |
9092 | if (!new && !cur) | |
9093 | return 1; | |
9094 | ||
9095 | tmp = SD_ATTR_INIT; | |
9096 | return !memcmp(cur ? (cur + idx_cur) : &tmp, | |
9097 | new ? (new + idx_new) : &tmp, | |
9098 | sizeof(struct sched_domain_attr)); | |
9099 | } | |
9100 | ||
029190c5 PJ |
9101 | /* |
9102 | * Partition sched domains as specified by the 'ndoms_new' | |
41a2d6cf | 9103 | * cpumasks in the array doms_new[] of cpumasks. This compares |
029190c5 PJ |
9104 | * doms_new[] to the current sched domain partitioning, doms_cur[]. |
9105 | * It destroys each deleted domain and builds each new domain. | |
9106 | * | |
acc3f5d7 | 9107 | * 'doms_new' is an array of cpumask_var_t's of length 'ndoms_new'. |
41a2d6cf IM |
9108 | * The masks don't intersect (don't overlap.) We should setup one |
9109 | * sched domain for each mask. CPUs not in any of the cpumasks will | |
9110 | * not be load balanced. If the same cpumask appears both in the | |
029190c5 PJ |
9111 | * current 'doms_cur' domains and in the new 'doms_new', we can leave |
9112 | * it as it is. | |
9113 | * | |
acc3f5d7 RR |
9114 | * The passed in 'doms_new' should be allocated using |
9115 | * alloc_sched_domains. This routine takes ownership of it and will | |
9116 | * free_sched_domains it when done with it. If the caller failed the | |
9117 | * alloc call, then it can pass in doms_new == NULL && ndoms_new == 1, | |
9118 | * and partition_sched_domains() will fallback to the single partition | |
9119 | * 'fallback_doms', it also forces the domains to be rebuilt. | |
029190c5 | 9120 | * |
96f874e2 | 9121 | * If doms_new == NULL it will be replaced with cpu_online_mask. |
700018e0 LZ |
9122 | * ndoms_new == 0 is a special case for destroying existing domains, |
9123 | * and it will not create the default domain. | |
dfb512ec | 9124 | * |
029190c5 PJ |
9125 | * Call with hotplug lock held |
9126 | */ | |
acc3f5d7 | 9127 | void partition_sched_domains(int ndoms_new, cpumask_var_t doms_new[], |
1d3504fc | 9128 | struct sched_domain_attr *dattr_new) |
029190c5 | 9129 | { |
dfb512ec | 9130 | int i, j, n; |
d65bd5ec | 9131 | int new_topology; |
029190c5 | 9132 | |
712555ee | 9133 | mutex_lock(&sched_domains_mutex); |
a1835615 | 9134 | |
7378547f MM |
9135 | /* always unregister in case we don't destroy any domains */ |
9136 | unregister_sched_domain_sysctl(); | |
9137 | ||
d65bd5ec HC |
9138 | /* Let architecture update cpu core mappings. */ |
9139 | new_topology = arch_update_cpu_topology(); | |
9140 | ||
dfb512ec | 9141 | n = doms_new ? ndoms_new : 0; |
029190c5 PJ |
9142 | |
9143 | /* Destroy deleted domains */ | |
9144 | for (i = 0; i < ndoms_cur; i++) { | |
d65bd5ec | 9145 | for (j = 0; j < n && !new_topology; j++) { |
acc3f5d7 | 9146 | if (cpumask_equal(doms_cur[i], doms_new[j]) |
1d3504fc | 9147 | && dattrs_equal(dattr_cur, i, dattr_new, j)) |
029190c5 PJ |
9148 | goto match1; |
9149 | } | |
9150 | /* no match - a current sched domain not in new doms_new[] */ | |
acc3f5d7 | 9151 | detach_destroy_domains(doms_cur[i]); |
029190c5 PJ |
9152 | match1: |
9153 | ; | |
9154 | } | |
9155 | ||
e761b772 MK |
9156 | if (doms_new == NULL) { |
9157 | ndoms_cur = 0; | |
acc3f5d7 | 9158 | doms_new = &fallback_doms; |
6ad4c188 | 9159 | cpumask_andnot(doms_new[0], cpu_active_mask, cpu_isolated_map); |
faa2f98f | 9160 | WARN_ON_ONCE(dattr_new); |
e761b772 MK |
9161 | } |
9162 | ||
029190c5 PJ |
9163 | /* Build new domains */ |
9164 | for (i = 0; i < ndoms_new; i++) { | |
d65bd5ec | 9165 | for (j = 0; j < ndoms_cur && !new_topology; j++) { |
acc3f5d7 | 9166 | if (cpumask_equal(doms_new[i], doms_cur[j]) |
1d3504fc | 9167 | && dattrs_equal(dattr_new, i, dattr_cur, j)) |
029190c5 PJ |
9168 | goto match2; |
9169 | } | |
9170 | /* no match - add a new doms_new */ | |
acc3f5d7 | 9171 | __build_sched_domains(doms_new[i], |
1d3504fc | 9172 | dattr_new ? dattr_new + i : NULL); |
029190c5 PJ |
9173 | match2: |
9174 | ; | |
9175 | } | |
9176 | ||
9177 | /* Remember the new sched domains */ | |
acc3f5d7 RR |
9178 | if (doms_cur != &fallback_doms) |
9179 | free_sched_domains(doms_cur, ndoms_cur); | |
1d3504fc | 9180 | kfree(dattr_cur); /* kfree(NULL) is safe */ |
029190c5 | 9181 | doms_cur = doms_new; |
1d3504fc | 9182 | dattr_cur = dattr_new; |
029190c5 | 9183 | ndoms_cur = ndoms_new; |
7378547f MM |
9184 | |
9185 | register_sched_domain_sysctl(); | |
a1835615 | 9186 | |
712555ee | 9187 | mutex_unlock(&sched_domains_mutex); |
029190c5 PJ |
9188 | } |
9189 | ||
5c45bf27 | 9190 | #if defined(CONFIG_SCHED_MC) || defined(CONFIG_SCHED_SMT) |
c70f22d2 | 9191 | static void arch_reinit_sched_domains(void) |
5c45bf27 | 9192 | { |
95402b38 | 9193 | get_online_cpus(); |
dfb512ec MK |
9194 | |
9195 | /* Destroy domains first to force the rebuild */ | |
9196 | partition_sched_domains(0, NULL, NULL); | |
9197 | ||
e761b772 | 9198 | rebuild_sched_domains(); |
95402b38 | 9199 | put_online_cpus(); |
5c45bf27 SS |
9200 | } |
9201 | ||
9202 | static ssize_t sched_power_savings_store(const char *buf, size_t count, int smt) | |
9203 | { | |
afb8a9b7 | 9204 | unsigned int level = 0; |
5c45bf27 | 9205 | |
afb8a9b7 GS |
9206 | if (sscanf(buf, "%u", &level) != 1) |
9207 | return -EINVAL; | |
9208 | ||
9209 | /* | |
9210 | * level is always be positive so don't check for | |
9211 | * level < POWERSAVINGS_BALANCE_NONE which is 0 | |
9212 | * What happens on 0 or 1 byte write, | |
9213 | * need to check for count as well? | |
9214 | */ | |
9215 | ||
9216 | if (level >= MAX_POWERSAVINGS_BALANCE_LEVELS) | |
5c45bf27 SS |
9217 | return -EINVAL; |
9218 | ||
9219 | if (smt) | |
afb8a9b7 | 9220 | sched_smt_power_savings = level; |
5c45bf27 | 9221 | else |
afb8a9b7 | 9222 | sched_mc_power_savings = level; |
5c45bf27 | 9223 | |
c70f22d2 | 9224 | arch_reinit_sched_domains(); |
5c45bf27 | 9225 | |
c70f22d2 | 9226 | return count; |
5c45bf27 SS |
9227 | } |
9228 | ||
5c45bf27 | 9229 | #ifdef CONFIG_SCHED_MC |
f718cd4a AK |
9230 | static ssize_t sched_mc_power_savings_show(struct sysdev_class *class, |
9231 | char *page) | |
5c45bf27 SS |
9232 | { |
9233 | return sprintf(page, "%u\n", sched_mc_power_savings); | |
9234 | } | |
f718cd4a | 9235 | static ssize_t sched_mc_power_savings_store(struct sysdev_class *class, |
48f24c4d | 9236 | const char *buf, size_t count) |
5c45bf27 SS |
9237 | { |
9238 | return sched_power_savings_store(buf, count, 0); | |
9239 | } | |
f718cd4a AK |
9240 | static SYSDEV_CLASS_ATTR(sched_mc_power_savings, 0644, |
9241 | sched_mc_power_savings_show, | |
9242 | sched_mc_power_savings_store); | |
5c45bf27 SS |
9243 | #endif |
9244 | ||
9245 | #ifdef CONFIG_SCHED_SMT | |
f718cd4a AK |
9246 | static ssize_t sched_smt_power_savings_show(struct sysdev_class *dev, |
9247 | char *page) | |
5c45bf27 SS |
9248 | { |
9249 | return sprintf(page, "%u\n", sched_smt_power_savings); | |
9250 | } | |
f718cd4a | 9251 | static ssize_t sched_smt_power_savings_store(struct sysdev_class *dev, |
48f24c4d | 9252 | const char *buf, size_t count) |
5c45bf27 SS |
9253 | { |
9254 | return sched_power_savings_store(buf, count, 1); | |
9255 | } | |
f718cd4a AK |
9256 | static SYSDEV_CLASS_ATTR(sched_smt_power_savings, 0644, |
9257 | sched_smt_power_savings_show, | |
6707de00 AB |
9258 | sched_smt_power_savings_store); |
9259 | #endif | |
9260 | ||
39aac648 | 9261 | int __init sched_create_sysfs_power_savings_entries(struct sysdev_class *cls) |
6707de00 AB |
9262 | { |
9263 | int err = 0; | |
9264 | ||
9265 | #ifdef CONFIG_SCHED_SMT | |
9266 | if (smt_capable()) | |
9267 | err = sysfs_create_file(&cls->kset.kobj, | |
9268 | &attr_sched_smt_power_savings.attr); | |
9269 | #endif | |
9270 | #ifdef CONFIG_SCHED_MC | |
9271 | if (!err && mc_capable()) | |
9272 | err = sysfs_create_file(&cls->kset.kobj, | |
9273 | &attr_sched_mc_power_savings.attr); | |
9274 | #endif | |
9275 | return err; | |
9276 | } | |
6d6bc0ad | 9277 | #endif /* CONFIG_SCHED_MC || CONFIG_SCHED_SMT */ |
5c45bf27 | 9278 | |
e761b772 | 9279 | #ifndef CONFIG_CPUSETS |
1da177e4 | 9280 | /* |
e761b772 MK |
9281 | * Add online and remove offline CPUs from the scheduler domains. |
9282 | * When cpusets are enabled they take over this function. | |
1da177e4 LT |
9283 | */ |
9284 | static int update_sched_domains(struct notifier_block *nfb, | |
9285 | unsigned long action, void *hcpu) | |
e761b772 MK |
9286 | { |
9287 | switch (action) { | |
9288 | case CPU_ONLINE: | |
9289 | case CPU_ONLINE_FROZEN: | |
6ad4c188 PZ |
9290 | case CPU_DOWN_PREPARE: |
9291 | case CPU_DOWN_PREPARE_FROZEN: | |
9292 | case CPU_DOWN_FAILED: | |
9293 | case CPU_DOWN_FAILED_FROZEN: | |
dfb512ec | 9294 | partition_sched_domains(1, NULL, NULL); |
e761b772 MK |
9295 | return NOTIFY_OK; |
9296 | ||
9297 | default: | |
9298 | return NOTIFY_DONE; | |
9299 | } | |
9300 | } | |
9301 | #endif | |
9302 | ||
9303 | static int update_runtime(struct notifier_block *nfb, | |
9304 | unsigned long action, void *hcpu) | |
1da177e4 | 9305 | { |
7def2be1 PZ |
9306 | int cpu = (int)(long)hcpu; |
9307 | ||
1da177e4 | 9308 | switch (action) { |
1da177e4 | 9309 | case CPU_DOWN_PREPARE: |
8bb78442 | 9310 | case CPU_DOWN_PREPARE_FROZEN: |
7def2be1 | 9311 | disable_runtime(cpu_rq(cpu)); |
1da177e4 LT |
9312 | return NOTIFY_OK; |
9313 | ||
1da177e4 | 9314 | case CPU_DOWN_FAILED: |
8bb78442 | 9315 | case CPU_DOWN_FAILED_FROZEN: |
1da177e4 | 9316 | case CPU_ONLINE: |
8bb78442 | 9317 | case CPU_ONLINE_FROZEN: |
7def2be1 | 9318 | enable_runtime(cpu_rq(cpu)); |
e761b772 MK |
9319 | return NOTIFY_OK; |
9320 | ||
1da177e4 LT |
9321 | default: |
9322 | return NOTIFY_DONE; | |
9323 | } | |
1da177e4 | 9324 | } |
1da177e4 LT |
9325 | |
9326 | void __init sched_init_smp(void) | |
9327 | { | |
dcc30a35 RR |
9328 | cpumask_var_t non_isolated_cpus; |
9329 | ||
9330 | alloc_cpumask_var(&non_isolated_cpus, GFP_KERNEL); | |
cb5fd13f | 9331 | alloc_cpumask_var(&fallback_doms, GFP_KERNEL); |
5c1e1767 | 9332 | |
434d53b0 MT |
9333 | #if defined(CONFIG_NUMA) |
9334 | sched_group_nodes_bycpu = kzalloc(nr_cpu_ids * sizeof(void **), | |
9335 | GFP_KERNEL); | |
9336 | BUG_ON(sched_group_nodes_bycpu == NULL); | |
9337 | #endif | |
95402b38 | 9338 | get_online_cpus(); |
712555ee | 9339 | mutex_lock(&sched_domains_mutex); |
6ad4c188 | 9340 | arch_init_sched_domains(cpu_active_mask); |
dcc30a35 RR |
9341 | cpumask_andnot(non_isolated_cpus, cpu_possible_mask, cpu_isolated_map); |
9342 | if (cpumask_empty(non_isolated_cpus)) | |
9343 | cpumask_set_cpu(smp_processor_id(), non_isolated_cpus); | |
712555ee | 9344 | mutex_unlock(&sched_domains_mutex); |
95402b38 | 9345 | put_online_cpus(); |
e761b772 MK |
9346 | |
9347 | #ifndef CONFIG_CPUSETS | |
1da177e4 LT |
9348 | /* XXX: Theoretical race here - CPU may be hotplugged now */ |
9349 | hotcpu_notifier(update_sched_domains, 0); | |
e761b772 MK |
9350 | #endif |
9351 | ||
9352 | /* RT runtime code needs to handle some hotplug events */ | |
9353 | hotcpu_notifier(update_runtime, 0); | |
9354 | ||
b328ca18 | 9355 | init_hrtick(); |
5c1e1767 NP |
9356 | |
9357 | /* Move init over to a non-isolated CPU */ | |
dcc30a35 | 9358 | if (set_cpus_allowed_ptr(current, non_isolated_cpus) < 0) |
5c1e1767 | 9359 | BUG(); |
19978ca6 | 9360 | sched_init_granularity(); |
dcc30a35 | 9361 | free_cpumask_var(non_isolated_cpus); |
4212823f | 9362 | |
0e3900e6 | 9363 | init_sched_rt_class(); |
1da177e4 LT |
9364 | } |
9365 | #else | |
9366 | void __init sched_init_smp(void) | |
9367 | { | |
19978ca6 | 9368 | sched_init_granularity(); |
1da177e4 LT |
9369 | } |
9370 | #endif /* CONFIG_SMP */ | |
9371 | ||
cd1bb94b AB |
9372 | const_debug unsigned int sysctl_timer_migration = 1; |
9373 | ||
1da177e4 LT |
9374 | int in_sched_functions(unsigned long addr) |
9375 | { | |
1da177e4 LT |
9376 | return in_lock_functions(addr) || |
9377 | (addr >= (unsigned long)__sched_text_start | |
9378 | && addr < (unsigned long)__sched_text_end); | |
9379 | } | |
9380 | ||
a9957449 | 9381 | static void init_cfs_rq(struct cfs_rq *cfs_rq, struct rq *rq) |
dd41f596 IM |
9382 | { |
9383 | cfs_rq->tasks_timeline = RB_ROOT; | |
4a55bd5e | 9384 | INIT_LIST_HEAD(&cfs_rq->tasks); |
dd41f596 IM |
9385 | #ifdef CONFIG_FAIR_GROUP_SCHED |
9386 | cfs_rq->rq = rq; | |
9387 | #endif | |
67e9fb2a | 9388 | cfs_rq->min_vruntime = (u64)(-(1LL << 20)); |
dd41f596 IM |
9389 | } |
9390 | ||
fa85ae24 PZ |
9391 | static void init_rt_rq(struct rt_rq *rt_rq, struct rq *rq) |
9392 | { | |
9393 | struct rt_prio_array *array; | |
9394 | int i; | |
9395 | ||
9396 | array = &rt_rq->active; | |
9397 | for (i = 0; i < MAX_RT_PRIO; i++) { | |
9398 | INIT_LIST_HEAD(array->queue + i); | |
9399 | __clear_bit(i, array->bitmap); | |
9400 | } | |
9401 | /* delimiter for bitsearch: */ | |
9402 | __set_bit(MAX_RT_PRIO, array->bitmap); | |
9403 | ||
052f1dc7 | 9404 | #if defined CONFIG_SMP || defined CONFIG_RT_GROUP_SCHED |
e864c499 | 9405 | rt_rq->highest_prio.curr = MAX_RT_PRIO; |
398a153b | 9406 | #ifdef CONFIG_SMP |
e864c499 | 9407 | rt_rq->highest_prio.next = MAX_RT_PRIO; |
48d5e258 | 9408 | #endif |
48d5e258 | 9409 | #endif |
fa85ae24 PZ |
9410 | #ifdef CONFIG_SMP |
9411 | rt_rq->rt_nr_migratory = 0; | |
fa85ae24 | 9412 | rt_rq->overloaded = 0; |
05fa785c | 9413 | plist_head_init_raw(&rt_rq->pushable_tasks, &rq->lock); |
fa85ae24 PZ |
9414 | #endif |
9415 | ||
9416 | rt_rq->rt_time = 0; | |
9417 | rt_rq->rt_throttled = 0; | |
ac086bc2 | 9418 | rt_rq->rt_runtime = 0; |
0986b11b | 9419 | raw_spin_lock_init(&rt_rq->rt_runtime_lock); |
6f505b16 | 9420 | |
052f1dc7 | 9421 | #ifdef CONFIG_RT_GROUP_SCHED |
23b0fdfc | 9422 | rt_rq->rt_nr_boosted = 0; |
6f505b16 PZ |
9423 | rt_rq->rq = rq; |
9424 | #endif | |
fa85ae24 PZ |
9425 | } |
9426 | ||
6f505b16 | 9427 | #ifdef CONFIG_FAIR_GROUP_SCHED |
ec7dc8ac DG |
9428 | static void init_tg_cfs_entry(struct task_group *tg, struct cfs_rq *cfs_rq, |
9429 | struct sched_entity *se, int cpu, int add, | |
9430 | struct sched_entity *parent) | |
6f505b16 | 9431 | { |
ec7dc8ac | 9432 | struct rq *rq = cpu_rq(cpu); |
6f505b16 PZ |
9433 | tg->cfs_rq[cpu] = cfs_rq; |
9434 | init_cfs_rq(cfs_rq, rq); | |
9435 | cfs_rq->tg = tg; | |
9436 | if (add) | |
9437 | list_add(&cfs_rq->leaf_cfs_rq_list, &rq->leaf_cfs_rq_list); | |
9438 | ||
9439 | tg->se[cpu] = se; | |
354d60c2 DG |
9440 | /* se could be NULL for init_task_group */ |
9441 | if (!se) | |
9442 | return; | |
9443 | ||
ec7dc8ac DG |
9444 | if (!parent) |
9445 | se->cfs_rq = &rq->cfs; | |
9446 | else | |
9447 | se->cfs_rq = parent->my_q; | |
9448 | ||
6f505b16 PZ |
9449 | se->my_q = cfs_rq; |
9450 | se->load.weight = tg->shares; | |
e05510d0 | 9451 | se->load.inv_weight = 0; |
ec7dc8ac | 9452 | se->parent = parent; |
6f505b16 | 9453 | } |
052f1dc7 | 9454 | #endif |
6f505b16 | 9455 | |
052f1dc7 | 9456 | #ifdef CONFIG_RT_GROUP_SCHED |
ec7dc8ac DG |
9457 | static void init_tg_rt_entry(struct task_group *tg, struct rt_rq *rt_rq, |
9458 | struct sched_rt_entity *rt_se, int cpu, int add, | |
9459 | struct sched_rt_entity *parent) | |
6f505b16 | 9460 | { |
ec7dc8ac DG |
9461 | struct rq *rq = cpu_rq(cpu); |
9462 | ||
6f505b16 PZ |
9463 | tg->rt_rq[cpu] = rt_rq; |
9464 | init_rt_rq(rt_rq, rq); | |
9465 | rt_rq->tg = tg; | |
9466 | rt_rq->rt_se = rt_se; | |
ac086bc2 | 9467 | rt_rq->rt_runtime = tg->rt_bandwidth.rt_runtime; |
6f505b16 PZ |
9468 | if (add) |
9469 | list_add(&rt_rq->leaf_rt_rq_list, &rq->leaf_rt_rq_list); | |
9470 | ||
9471 | tg->rt_se[cpu] = rt_se; | |
354d60c2 DG |
9472 | if (!rt_se) |
9473 | return; | |
9474 | ||
ec7dc8ac DG |
9475 | if (!parent) |
9476 | rt_se->rt_rq = &rq->rt; | |
9477 | else | |
9478 | rt_se->rt_rq = parent->my_q; | |
9479 | ||
6f505b16 | 9480 | rt_se->my_q = rt_rq; |
ec7dc8ac | 9481 | rt_se->parent = parent; |
6f505b16 PZ |
9482 | INIT_LIST_HEAD(&rt_se->run_list); |
9483 | } | |
9484 | #endif | |
9485 | ||
1da177e4 LT |
9486 | void __init sched_init(void) |
9487 | { | |
dd41f596 | 9488 | int i, j; |
434d53b0 MT |
9489 | unsigned long alloc_size = 0, ptr; |
9490 | ||
9491 | #ifdef CONFIG_FAIR_GROUP_SCHED | |
9492 | alloc_size += 2 * nr_cpu_ids * sizeof(void **); | |
9493 | #endif | |
9494 | #ifdef CONFIG_RT_GROUP_SCHED | |
9495 | alloc_size += 2 * nr_cpu_ids * sizeof(void **); | |
eff766a6 PZ |
9496 | #endif |
9497 | #ifdef CONFIG_USER_SCHED | |
9498 | alloc_size *= 2; | |
df7c8e84 RR |
9499 | #endif |
9500 | #ifdef CONFIG_CPUMASK_OFFSTACK | |
8c083f08 | 9501 | alloc_size += num_possible_cpus() * cpumask_size(); |
434d53b0 | 9502 | #endif |
434d53b0 | 9503 | if (alloc_size) { |
36b7b6d4 | 9504 | ptr = (unsigned long)kzalloc(alloc_size, GFP_NOWAIT); |
434d53b0 MT |
9505 | |
9506 | #ifdef CONFIG_FAIR_GROUP_SCHED | |
9507 | init_task_group.se = (struct sched_entity **)ptr; | |
9508 | ptr += nr_cpu_ids * sizeof(void **); | |
9509 | ||
9510 | init_task_group.cfs_rq = (struct cfs_rq **)ptr; | |
9511 | ptr += nr_cpu_ids * sizeof(void **); | |
eff766a6 PZ |
9512 | |
9513 | #ifdef CONFIG_USER_SCHED | |
9514 | root_task_group.se = (struct sched_entity **)ptr; | |
9515 | ptr += nr_cpu_ids * sizeof(void **); | |
9516 | ||
9517 | root_task_group.cfs_rq = (struct cfs_rq **)ptr; | |
9518 | ptr += nr_cpu_ids * sizeof(void **); | |
6d6bc0ad DG |
9519 | #endif /* CONFIG_USER_SCHED */ |
9520 | #endif /* CONFIG_FAIR_GROUP_SCHED */ | |
434d53b0 MT |
9521 | #ifdef CONFIG_RT_GROUP_SCHED |
9522 | init_task_group.rt_se = (struct sched_rt_entity **)ptr; | |
9523 | ptr += nr_cpu_ids * sizeof(void **); | |
9524 | ||
9525 | init_task_group.rt_rq = (struct rt_rq **)ptr; | |
eff766a6 PZ |
9526 | ptr += nr_cpu_ids * sizeof(void **); |
9527 | ||
9528 | #ifdef CONFIG_USER_SCHED | |
9529 | root_task_group.rt_se = (struct sched_rt_entity **)ptr; | |
9530 | ptr += nr_cpu_ids * sizeof(void **); | |
9531 | ||
9532 | root_task_group.rt_rq = (struct rt_rq **)ptr; | |
9533 | ptr += nr_cpu_ids * sizeof(void **); | |
6d6bc0ad DG |
9534 | #endif /* CONFIG_USER_SCHED */ |
9535 | #endif /* CONFIG_RT_GROUP_SCHED */ | |
df7c8e84 RR |
9536 | #ifdef CONFIG_CPUMASK_OFFSTACK |
9537 | for_each_possible_cpu(i) { | |
9538 | per_cpu(load_balance_tmpmask, i) = (void *)ptr; | |
9539 | ptr += cpumask_size(); | |
9540 | } | |
9541 | #endif /* CONFIG_CPUMASK_OFFSTACK */ | |
434d53b0 | 9542 | } |
dd41f596 | 9543 | |
57d885fe GH |
9544 | #ifdef CONFIG_SMP |
9545 | init_defrootdomain(); | |
9546 | #endif | |
9547 | ||
d0b27fa7 PZ |
9548 | init_rt_bandwidth(&def_rt_bandwidth, |
9549 | global_rt_period(), global_rt_runtime()); | |
9550 | ||
9551 | #ifdef CONFIG_RT_GROUP_SCHED | |
9552 | init_rt_bandwidth(&init_task_group.rt_bandwidth, | |
9553 | global_rt_period(), global_rt_runtime()); | |
eff766a6 PZ |
9554 | #ifdef CONFIG_USER_SCHED |
9555 | init_rt_bandwidth(&root_task_group.rt_bandwidth, | |
9556 | global_rt_period(), RUNTIME_INF); | |
6d6bc0ad DG |
9557 | #endif /* CONFIG_USER_SCHED */ |
9558 | #endif /* CONFIG_RT_GROUP_SCHED */ | |
d0b27fa7 | 9559 | |
052f1dc7 | 9560 | #ifdef CONFIG_GROUP_SCHED |
6f505b16 | 9561 | list_add(&init_task_group.list, &task_groups); |
f473aa5e PZ |
9562 | INIT_LIST_HEAD(&init_task_group.children); |
9563 | ||
9564 | #ifdef CONFIG_USER_SCHED | |
9565 | INIT_LIST_HEAD(&root_task_group.children); | |
9566 | init_task_group.parent = &root_task_group; | |
9567 | list_add(&init_task_group.siblings, &root_task_group.children); | |
6d6bc0ad DG |
9568 | #endif /* CONFIG_USER_SCHED */ |
9569 | #endif /* CONFIG_GROUP_SCHED */ | |
6f505b16 | 9570 | |
4a6cc4bd JK |
9571 | #if defined CONFIG_FAIR_GROUP_SCHED && defined CONFIG_SMP |
9572 | update_shares_data = __alloc_percpu(nr_cpu_ids * sizeof(unsigned long), | |
9573 | __alignof__(unsigned long)); | |
9574 | #endif | |
0a945022 | 9575 | for_each_possible_cpu(i) { |
70b97a7f | 9576 | struct rq *rq; |
1da177e4 LT |
9577 | |
9578 | rq = cpu_rq(i); | |
05fa785c | 9579 | raw_spin_lock_init(&rq->lock); |
7897986b | 9580 | rq->nr_running = 0; |
dce48a84 TG |
9581 | rq->calc_load_active = 0; |
9582 | rq->calc_load_update = jiffies + LOAD_FREQ; | |
dd41f596 | 9583 | init_cfs_rq(&rq->cfs, rq); |
6f505b16 | 9584 | init_rt_rq(&rq->rt, rq); |
dd41f596 | 9585 | #ifdef CONFIG_FAIR_GROUP_SCHED |
4cf86d77 | 9586 | init_task_group.shares = init_task_group_load; |
6f505b16 | 9587 | INIT_LIST_HEAD(&rq->leaf_cfs_rq_list); |
354d60c2 DG |
9588 | #ifdef CONFIG_CGROUP_SCHED |
9589 | /* | |
9590 | * How much cpu bandwidth does init_task_group get? | |
9591 | * | |
9592 | * In case of task-groups formed thr' the cgroup filesystem, it | |
9593 | * gets 100% of the cpu resources in the system. This overall | |
9594 | * system cpu resource is divided among the tasks of | |
9595 | * init_task_group and its child task-groups in a fair manner, | |
9596 | * based on each entity's (task or task-group's) weight | |
9597 | * (se->load.weight). | |
9598 | * | |
9599 | * In other words, if init_task_group has 10 tasks of weight | |
9600 | * 1024) and two child groups A0 and A1 (of weight 1024 each), | |
9601 | * then A0's share of the cpu resource is: | |
9602 | * | |
0d905bca | 9603 | * A0's bandwidth = 1024 / (10*1024 + 1024 + 1024) = 8.33% |
354d60c2 DG |
9604 | * |
9605 | * We achieve this by letting init_task_group's tasks sit | |
9606 | * directly in rq->cfs (i.e init_task_group->se[] = NULL). | |
9607 | */ | |
ec7dc8ac | 9608 | init_tg_cfs_entry(&init_task_group, &rq->cfs, NULL, i, 1, NULL); |
354d60c2 | 9609 | #elif defined CONFIG_USER_SCHED |
eff766a6 PZ |
9610 | root_task_group.shares = NICE_0_LOAD; |
9611 | init_tg_cfs_entry(&root_task_group, &rq->cfs, NULL, i, 0, NULL); | |
354d60c2 DG |
9612 | /* |
9613 | * In case of task-groups formed thr' the user id of tasks, | |
9614 | * init_task_group represents tasks belonging to root user. | |
9615 | * Hence it forms a sibling of all subsequent groups formed. | |
9616 | * In this case, init_task_group gets only a fraction of overall | |
9617 | * system cpu resource, based on the weight assigned to root | |
9618 | * user's cpu share (INIT_TASK_GROUP_LOAD). This is accomplished | |
9619 | * by letting tasks of init_task_group sit in a separate cfs_rq | |
84e9dabf | 9620 | * (init_tg_cfs_rq) and having one entity represent this group of |
354d60c2 DG |
9621 | * tasks in rq->cfs (i.e init_task_group->se[] != NULL). |
9622 | */ | |
ec7dc8ac | 9623 | init_tg_cfs_entry(&init_task_group, |
84e9dabf | 9624 | &per_cpu(init_tg_cfs_rq, i), |
eff766a6 PZ |
9625 | &per_cpu(init_sched_entity, i), i, 1, |
9626 | root_task_group.se[i]); | |
6f505b16 | 9627 | |
052f1dc7 | 9628 | #endif |
354d60c2 DG |
9629 | #endif /* CONFIG_FAIR_GROUP_SCHED */ |
9630 | ||
9631 | rq->rt.rt_runtime = def_rt_bandwidth.rt_runtime; | |
052f1dc7 | 9632 | #ifdef CONFIG_RT_GROUP_SCHED |
6f505b16 | 9633 | INIT_LIST_HEAD(&rq->leaf_rt_rq_list); |
354d60c2 | 9634 | #ifdef CONFIG_CGROUP_SCHED |
ec7dc8ac | 9635 | init_tg_rt_entry(&init_task_group, &rq->rt, NULL, i, 1, NULL); |
354d60c2 | 9636 | #elif defined CONFIG_USER_SCHED |
eff766a6 | 9637 | init_tg_rt_entry(&root_task_group, &rq->rt, NULL, i, 0, NULL); |
ec7dc8ac | 9638 | init_tg_rt_entry(&init_task_group, |
1871e52c | 9639 | &per_cpu(init_rt_rq_var, i), |
eff766a6 PZ |
9640 | &per_cpu(init_sched_rt_entity, i), i, 1, |
9641 | root_task_group.rt_se[i]); | |
354d60c2 | 9642 | #endif |
dd41f596 | 9643 | #endif |
1da177e4 | 9644 | |
dd41f596 IM |
9645 | for (j = 0; j < CPU_LOAD_IDX_MAX; j++) |
9646 | rq->cpu_load[j] = 0; | |
1da177e4 | 9647 | #ifdef CONFIG_SMP |
41c7ce9a | 9648 | rq->sd = NULL; |
57d885fe | 9649 | rq->rd = NULL; |
3f029d3c | 9650 | rq->post_schedule = 0; |
1da177e4 | 9651 | rq->active_balance = 0; |
dd41f596 | 9652 | rq->next_balance = jiffies; |
1da177e4 | 9653 | rq->push_cpu = 0; |
0a2966b4 | 9654 | rq->cpu = i; |
1f11eb6a | 9655 | rq->online = 0; |
1da177e4 | 9656 | rq->migration_thread = NULL; |
eae0c9df MG |
9657 | rq->idle_stamp = 0; |
9658 | rq->avg_idle = 2*sysctl_sched_migration_cost; | |
1da177e4 | 9659 | INIT_LIST_HEAD(&rq->migration_queue); |
dc938520 | 9660 | rq_attach_root(rq, &def_root_domain); |
1da177e4 | 9661 | #endif |
8f4d37ec | 9662 | init_rq_hrtick(rq); |
1da177e4 | 9663 | atomic_set(&rq->nr_iowait, 0); |
1da177e4 LT |
9664 | } |
9665 | ||
2dd73a4f | 9666 | set_load_weight(&init_task); |
b50f60ce | 9667 | |
e107be36 AK |
9668 | #ifdef CONFIG_PREEMPT_NOTIFIERS |
9669 | INIT_HLIST_HEAD(&init_task.preempt_notifiers); | |
9670 | #endif | |
9671 | ||
c9819f45 | 9672 | #ifdef CONFIG_SMP |
962cf36c | 9673 | open_softirq(SCHED_SOFTIRQ, run_rebalance_domains); |
c9819f45 CL |
9674 | #endif |
9675 | ||
b50f60ce | 9676 | #ifdef CONFIG_RT_MUTEXES |
1d615482 | 9677 | plist_head_init_raw(&init_task.pi_waiters, &init_task.pi_lock); |
b50f60ce HC |
9678 | #endif |
9679 | ||
1da177e4 LT |
9680 | /* |
9681 | * The boot idle thread does lazy MMU switching as well: | |
9682 | */ | |
9683 | atomic_inc(&init_mm.mm_count); | |
9684 | enter_lazy_tlb(&init_mm, current); | |
9685 | ||
9686 | /* | |
9687 | * Make us the idle thread. Technically, schedule() should not be | |
9688 | * called from this thread, however somewhere below it might be, | |
9689 | * but because we are the idle thread, we just pick up running again | |
9690 | * when this runqueue becomes "idle". | |
9691 | */ | |
9692 | init_idle(current, smp_processor_id()); | |
dce48a84 TG |
9693 | |
9694 | calc_load_update = jiffies + LOAD_FREQ; | |
9695 | ||
dd41f596 IM |
9696 | /* |
9697 | * During early bootup we pretend to be a normal task: | |
9698 | */ | |
9699 | current->sched_class = &fair_sched_class; | |
6892b75e | 9700 | |
6a7b3dc3 | 9701 | /* Allocate the nohz_cpu_mask if CONFIG_CPUMASK_OFFSTACK */ |
49557e62 | 9702 | zalloc_cpumask_var(&nohz_cpu_mask, GFP_NOWAIT); |
bf4d83f6 | 9703 | #ifdef CONFIG_SMP |
7d1e6a9b | 9704 | #ifdef CONFIG_NO_HZ |
49557e62 | 9705 | zalloc_cpumask_var(&nohz.cpu_mask, GFP_NOWAIT); |
4bdddf8f | 9706 | alloc_cpumask_var(&nohz.ilb_grp_nohz_mask, GFP_NOWAIT); |
7d1e6a9b | 9707 | #endif |
bdddd296 RR |
9708 | /* May be allocated at isolcpus cmdline parse time */ |
9709 | if (cpu_isolated_map == NULL) | |
9710 | zalloc_cpumask_var(&cpu_isolated_map, GFP_NOWAIT); | |
bf4d83f6 | 9711 | #endif /* SMP */ |
6a7b3dc3 | 9712 | |
cdd6c482 | 9713 | perf_event_init(); |
0d905bca | 9714 | |
6892b75e | 9715 | scheduler_running = 1; |
1da177e4 LT |
9716 | } |
9717 | ||
9718 | #ifdef CONFIG_DEBUG_SPINLOCK_SLEEP | |
e4aafea2 FW |
9719 | static inline int preempt_count_equals(int preempt_offset) |
9720 | { | |
234da7bc | 9721 | int nested = (preempt_count() & ~PREEMPT_ACTIVE) + rcu_preempt_depth(); |
e4aafea2 FW |
9722 | |
9723 | return (nested == PREEMPT_INATOMIC_BASE + preempt_offset); | |
9724 | } | |
9725 | ||
9726 | void __might_sleep(char *file, int line, int preempt_offset) | |
1da177e4 | 9727 | { |
48f24c4d | 9728 | #ifdef in_atomic |
1da177e4 LT |
9729 | static unsigned long prev_jiffy; /* ratelimiting */ |
9730 | ||
e4aafea2 FW |
9731 | if ((preempt_count_equals(preempt_offset) && !irqs_disabled()) || |
9732 | system_state != SYSTEM_RUNNING || oops_in_progress) | |
aef745fc IM |
9733 | return; |
9734 | if (time_before(jiffies, prev_jiffy + HZ) && prev_jiffy) | |
9735 | return; | |
9736 | prev_jiffy = jiffies; | |
9737 | ||
3df0fc5b PZ |
9738 | printk(KERN_ERR |
9739 | "BUG: sleeping function called from invalid context at %s:%d\n", | |
9740 | file, line); | |
9741 | printk(KERN_ERR | |
9742 | "in_atomic(): %d, irqs_disabled(): %d, pid: %d, name: %s\n", | |
9743 | in_atomic(), irqs_disabled(), | |
9744 | current->pid, current->comm); | |
aef745fc IM |
9745 | |
9746 | debug_show_held_locks(current); | |
9747 | if (irqs_disabled()) | |
9748 | print_irqtrace_events(current); | |
9749 | dump_stack(); | |
1da177e4 LT |
9750 | #endif |
9751 | } | |
9752 | EXPORT_SYMBOL(__might_sleep); | |
9753 | #endif | |
9754 | ||
9755 | #ifdef CONFIG_MAGIC_SYSRQ | |
3a5e4dc1 AK |
9756 | static void normalize_task(struct rq *rq, struct task_struct *p) |
9757 | { | |
9758 | int on_rq; | |
3e51f33f | 9759 | |
3a5e4dc1 AK |
9760 | update_rq_clock(rq); |
9761 | on_rq = p->se.on_rq; | |
9762 | if (on_rq) | |
9763 | deactivate_task(rq, p, 0); | |
9764 | __setscheduler(rq, p, SCHED_NORMAL, 0); | |
9765 | if (on_rq) { | |
9766 | activate_task(rq, p, 0); | |
9767 | resched_task(rq->curr); | |
9768 | } | |
9769 | } | |
9770 | ||
1da177e4 LT |
9771 | void normalize_rt_tasks(void) |
9772 | { | |
a0f98a1c | 9773 | struct task_struct *g, *p; |
1da177e4 | 9774 | unsigned long flags; |
70b97a7f | 9775 | struct rq *rq; |
1da177e4 | 9776 | |
4cf5d77a | 9777 | read_lock_irqsave(&tasklist_lock, flags); |
a0f98a1c | 9778 | do_each_thread(g, p) { |
178be793 IM |
9779 | /* |
9780 | * Only normalize user tasks: | |
9781 | */ | |
9782 | if (!p->mm) | |
9783 | continue; | |
9784 | ||
6cfb0d5d | 9785 | p->se.exec_start = 0; |
6cfb0d5d | 9786 | #ifdef CONFIG_SCHEDSTATS |
dd41f596 | 9787 | p->se.wait_start = 0; |
dd41f596 | 9788 | p->se.sleep_start = 0; |
dd41f596 | 9789 | p->se.block_start = 0; |
6cfb0d5d | 9790 | #endif |
dd41f596 IM |
9791 | |
9792 | if (!rt_task(p)) { | |
9793 | /* | |
9794 | * Renice negative nice level userspace | |
9795 | * tasks back to 0: | |
9796 | */ | |
9797 | if (TASK_NICE(p) < 0 && p->mm) | |
9798 | set_user_nice(p, 0); | |
1da177e4 | 9799 | continue; |
dd41f596 | 9800 | } |
1da177e4 | 9801 | |
1d615482 | 9802 | raw_spin_lock(&p->pi_lock); |
b29739f9 | 9803 | rq = __task_rq_lock(p); |
1da177e4 | 9804 | |
178be793 | 9805 | normalize_task(rq, p); |
3a5e4dc1 | 9806 | |
b29739f9 | 9807 | __task_rq_unlock(rq); |
1d615482 | 9808 | raw_spin_unlock(&p->pi_lock); |
a0f98a1c IM |
9809 | } while_each_thread(g, p); |
9810 | ||
4cf5d77a | 9811 | read_unlock_irqrestore(&tasklist_lock, flags); |
1da177e4 LT |
9812 | } |
9813 | ||
9814 | #endif /* CONFIG_MAGIC_SYSRQ */ | |
1df5c10a LT |
9815 | |
9816 | #ifdef CONFIG_IA64 | |
9817 | /* | |
9818 | * These functions are only useful for the IA64 MCA handling. | |
9819 | * | |
9820 | * They can only be called when the whole system has been | |
9821 | * stopped - every CPU needs to be quiescent, and no scheduling | |
9822 | * activity can take place. Using them for anything else would | |
9823 | * be a serious bug, and as a result, they aren't even visible | |
9824 | * under any other configuration. | |
9825 | */ | |
9826 | ||
9827 | /** | |
9828 | * curr_task - return the current task for a given cpu. | |
9829 | * @cpu: the processor in question. | |
9830 | * | |
9831 | * ONLY VALID WHEN THE WHOLE SYSTEM IS STOPPED! | |
9832 | */ | |
36c8b586 | 9833 | struct task_struct *curr_task(int cpu) |
1df5c10a LT |
9834 | { |
9835 | return cpu_curr(cpu); | |
9836 | } | |
9837 | ||
9838 | /** | |
9839 | * set_curr_task - set the current task for a given cpu. | |
9840 | * @cpu: the processor in question. | |
9841 | * @p: the task pointer to set. | |
9842 | * | |
9843 | * Description: This function must only be used when non-maskable interrupts | |
41a2d6cf IM |
9844 | * are serviced on a separate stack. It allows the architecture to switch the |
9845 | * notion of the current task on a cpu in a non-blocking manner. This function | |
1df5c10a LT |
9846 | * must be called with all CPU's synchronized, and interrupts disabled, the |
9847 | * and caller must save the original value of the current task (see | |
9848 | * curr_task() above) and restore that value before reenabling interrupts and | |
9849 | * re-starting the system. | |
9850 | * | |
9851 | * ONLY VALID WHEN THE WHOLE SYSTEM IS STOPPED! | |
9852 | */ | |
36c8b586 | 9853 | void set_curr_task(int cpu, struct task_struct *p) |
1df5c10a LT |
9854 | { |
9855 | cpu_curr(cpu) = p; | |
9856 | } | |
9857 | ||
9858 | #endif | |
29f59db3 | 9859 | |
bccbe08a PZ |
9860 | #ifdef CONFIG_FAIR_GROUP_SCHED |
9861 | static void free_fair_sched_group(struct task_group *tg) | |
6f505b16 PZ |
9862 | { |
9863 | int i; | |
9864 | ||
9865 | for_each_possible_cpu(i) { | |
9866 | if (tg->cfs_rq) | |
9867 | kfree(tg->cfs_rq[i]); | |
9868 | if (tg->se) | |
9869 | kfree(tg->se[i]); | |
6f505b16 PZ |
9870 | } |
9871 | ||
9872 | kfree(tg->cfs_rq); | |
9873 | kfree(tg->se); | |
6f505b16 PZ |
9874 | } |
9875 | ||
ec7dc8ac DG |
9876 | static |
9877 | int alloc_fair_sched_group(struct task_group *tg, struct task_group *parent) | |
29f59db3 | 9878 | { |
29f59db3 | 9879 | struct cfs_rq *cfs_rq; |
eab17229 | 9880 | struct sched_entity *se; |
9b5b7751 | 9881 | struct rq *rq; |
29f59db3 SV |
9882 | int i; |
9883 | ||
434d53b0 | 9884 | tg->cfs_rq = kzalloc(sizeof(cfs_rq) * nr_cpu_ids, GFP_KERNEL); |
29f59db3 SV |
9885 | if (!tg->cfs_rq) |
9886 | goto err; | |
434d53b0 | 9887 | tg->se = kzalloc(sizeof(se) * nr_cpu_ids, GFP_KERNEL); |
29f59db3 SV |
9888 | if (!tg->se) |
9889 | goto err; | |
052f1dc7 PZ |
9890 | |
9891 | tg->shares = NICE_0_LOAD; | |
29f59db3 SV |
9892 | |
9893 | for_each_possible_cpu(i) { | |
9b5b7751 | 9894 | rq = cpu_rq(i); |
29f59db3 | 9895 | |
eab17229 LZ |
9896 | cfs_rq = kzalloc_node(sizeof(struct cfs_rq), |
9897 | GFP_KERNEL, cpu_to_node(i)); | |
29f59db3 SV |
9898 | if (!cfs_rq) |
9899 | goto err; | |
9900 | ||
eab17229 LZ |
9901 | se = kzalloc_node(sizeof(struct sched_entity), |
9902 | GFP_KERNEL, cpu_to_node(i)); | |
29f59db3 | 9903 | if (!se) |
dfc12eb2 | 9904 | goto err_free_rq; |
29f59db3 | 9905 | |
eab17229 | 9906 | init_tg_cfs_entry(tg, cfs_rq, se, i, 0, parent->se[i]); |
bccbe08a PZ |
9907 | } |
9908 | ||
9909 | return 1; | |
9910 | ||
dfc12eb2 PC |
9911 | err_free_rq: |
9912 | kfree(cfs_rq); | |
bccbe08a PZ |
9913 | err: |
9914 | return 0; | |
9915 | } | |
9916 | ||
9917 | static inline void register_fair_sched_group(struct task_group *tg, int cpu) | |
9918 | { | |
9919 | list_add_rcu(&tg->cfs_rq[cpu]->leaf_cfs_rq_list, | |
9920 | &cpu_rq(cpu)->leaf_cfs_rq_list); | |
9921 | } | |
9922 | ||
9923 | static inline void unregister_fair_sched_group(struct task_group *tg, int cpu) | |
9924 | { | |
9925 | list_del_rcu(&tg->cfs_rq[cpu]->leaf_cfs_rq_list); | |
9926 | } | |
6d6bc0ad | 9927 | #else /* !CONFG_FAIR_GROUP_SCHED */ |
bccbe08a PZ |
9928 | static inline void free_fair_sched_group(struct task_group *tg) |
9929 | { | |
9930 | } | |
9931 | ||
ec7dc8ac DG |
9932 | static inline |
9933 | int alloc_fair_sched_group(struct task_group *tg, struct task_group *parent) | |
bccbe08a PZ |
9934 | { |
9935 | return 1; | |
9936 | } | |
9937 | ||
9938 | static inline void register_fair_sched_group(struct task_group *tg, int cpu) | |
9939 | { | |
9940 | } | |
9941 | ||
9942 | static inline void unregister_fair_sched_group(struct task_group *tg, int cpu) | |
9943 | { | |
9944 | } | |
6d6bc0ad | 9945 | #endif /* CONFIG_FAIR_GROUP_SCHED */ |
052f1dc7 PZ |
9946 | |
9947 | #ifdef CONFIG_RT_GROUP_SCHED | |
bccbe08a PZ |
9948 | static void free_rt_sched_group(struct task_group *tg) |
9949 | { | |
9950 | int i; | |
9951 | ||
d0b27fa7 PZ |
9952 | destroy_rt_bandwidth(&tg->rt_bandwidth); |
9953 | ||
bccbe08a PZ |
9954 | for_each_possible_cpu(i) { |
9955 | if (tg->rt_rq) | |
9956 | kfree(tg->rt_rq[i]); | |
9957 | if (tg->rt_se) | |
9958 | kfree(tg->rt_se[i]); | |
9959 | } | |
9960 | ||
9961 | kfree(tg->rt_rq); | |
9962 | kfree(tg->rt_se); | |
9963 | } | |
9964 | ||
ec7dc8ac DG |
9965 | static |
9966 | int alloc_rt_sched_group(struct task_group *tg, struct task_group *parent) | |
bccbe08a PZ |
9967 | { |
9968 | struct rt_rq *rt_rq; | |
eab17229 | 9969 | struct sched_rt_entity *rt_se; |
bccbe08a PZ |
9970 | struct rq *rq; |
9971 | int i; | |
9972 | ||
434d53b0 | 9973 | tg->rt_rq = kzalloc(sizeof(rt_rq) * nr_cpu_ids, GFP_KERNEL); |
bccbe08a PZ |
9974 | if (!tg->rt_rq) |
9975 | goto err; | |
434d53b0 | 9976 | tg->rt_se = kzalloc(sizeof(rt_se) * nr_cpu_ids, GFP_KERNEL); |
bccbe08a PZ |
9977 | if (!tg->rt_se) |
9978 | goto err; | |
9979 | ||
d0b27fa7 PZ |
9980 | init_rt_bandwidth(&tg->rt_bandwidth, |
9981 | ktime_to_ns(def_rt_bandwidth.rt_period), 0); | |
bccbe08a PZ |
9982 | |
9983 | for_each_possible_cpu(i) { | |
9984 | rq = cpu_rq(i); | |
9985 | ||
eab17229 LZ |
9986 | rt_rq = kzalloc_node(sizeof(struct rt_rq), |
9987 | GFP_KERNEL, cpu_to_node(i)); | |
6f505b16 PZ |
9988 | if (!rt_rq) |
9989 | goto err; | |
29f59db3 | 9990 | |
eab17229 LZ |
9991 | rt_se = kzalloc_node(sizeof(struct sched_rt_entity), |
9992 | GFP_KERNEL, cpu_to_node(i)); | |
6f505b16 | 9993 | if (!rt_se) |
dfc12eb2 | 9994 | goto err_free_rq; |
29f59db3 | 9995 | |
eab17229 | 9996 | init_tg_rt_entry(tg, rt_rq, rt_se, i, 0, parent->rt_se[i]); |
29f59db3 SV |
9997 | } |
9998 | ||
bccbe08a PZ |
9999 | return 1; |
10000 | ||
dfc12eb2 PC |
10001 | err_free_rq: |
10002 | kfree(rt_rq); | |
bccbe08a PZ |
10003 | err: |
10004 | return 0; | |
10005 | } | |
10006 | ||
10007 | static inline void register_rt_sched_group(struct task_group *tg, int cpu) | |
10008 | { | |
10009 | list_add_rcu(&tg->rt_rq[cpu]->leaf_rt_rq_list, | |
10010 | &cpu_rq(cpu)->leaf_rt_rq_list); | |
10011 | } | |
10012 | ||
10013 | static inline void unregister_rt_sched_group(struct task_group *tg, int cpu) | |
10014 | { | |
10015 | list_del_rcu(&tg->rt_rq[cpu]->leaf_rt_rq_list); | |
10016 | } | |
6d6bc0ad | 10017 | #else /* !CONFIG_RT_GROUP_SCHED */ |
bccbe08a PZ |
10018 | static inline void free_rt_sched_group(struct task_group *tg) |
10019 | { | |
10020 | } | |
10021 | ||
ec7dc8ac DG |
10022 | static inline |
10023 | int alloc_rt_sched_group(struct task_group *tg, struct task_group *parent) | |
bccbe08a PZ |
10024 | { |
10025 | return 1; | |
10026 | } | |
10027 | ||
10028 | static inline void register_rt_sched_group(struct task_group *tg, int cpu) | |
10029 | { | |
10030 | } | |
10031 | ||
10032 | static inline void unregister_rt_sched_group(struct task_group *tg, int cpu) | |
10033 | { | |
10034 | } | |
6d6bc0ad | 10035 | #endif /* CONFIG_RT_GROUP_SCHED */ |
bccbe08a | 10036 | |
d0b27fa7 | 10037 | #ifdef CONFIG_GROUP_SCHED |
bccbe08a PZ |
10038 | static void free_sched_group(struct task_group *tg) |
10039 | { | |
10040 | free_fair_sched_group(tg); | |
10041 | free_rt_sched_group(tg); | |
10042 | kfree(tg); | |
10043 | } | |
10044 | ||
10045 | /* allocate runqueue etc for a new task group */ | |
ec7dc8ac | 10046 | struct task_group *sched_create_group(struct task_group *parent) |
bccbe08a PZ |
10047 | { |
10048 | struct task_group *tg; | |
10049 | unsigned long flags; | |
10050 | int i; | |
10051 | ||
10052 | tg = kzalloc(sizeof(*tg), GFP_KERNEL); | |
10053 | if (!tg) | |
10054 | return ERR_PTR(-ENOMEM); | |
10055 | ||
ec7dc8ac | 10056 | if (!alloc_fair_sched_group(tg, parent)) |
bccbe08a PZ |
10057 | goto err; |
10058 | ||
ec7dc8ac | 10059 | if (!alloc_rt_sched_group(tg, parent)) |
bccbe08a PZ |
10060 | goto err; |
10061 | ||
8ed36996 | 10062 | spin_lock_irqsave(&task_group_lock, flags); |
9b5b7751 | 10063 | for_each_possible_cpu(i) { |
bccbe08a PZ |
10064 | register_fair_sched_group(tg, i); |
10065 | register_rt_sched_group(tg, i); | |
9b5b7751 | 10066 | } |
6f505b16 | 10067 | list_add_rcu(&tg->list, &task_groups); |
f473aa5e PZ |
10068 | |
10069 | WARN_ON(!parent); /* root should already exist */ | |
10070 | ||
10071 | tg->parent = parent; | |
f473aa5e | 10072 | INIT_LIST_HEAD(&tg->children); |
09f2724a | 10073 | list_add_rcu(&tg->siblings, &parent->children); |
8ed36996 | 10074 | spin_unlock_irqrestore(&task_group_lock, flags); |
29f59db3 | 10075 | |
9b5b7751 | 10076 | return tg; |
29f59db3 SV |
10077 | |
10078 | err: | |
6f505b16 | 10079 | free_sched_group(tg); |
29f59db3 SV |
10080 | return ERR_PTR(-ENOMEM); |
10081 | } | |
10082 | ||
9b5b7751 | 10083 | /* rcu callback to free various structures associated with a task group */ |
6f505b16 | 10084 | static void free_sched_group_rcu(struct rcu_head *rhp) |
29f59db3 | 10085 | { |
29f59db3 | 10086 | /* now it should be safe to free those cfs_rqs */ |
6f505b16 | 10087 | free_sched_group(container_of(rhp, struct task_group, rcu)); |
29f59db3 SV |
10088 | } |
10089 | ||
9b5b7751 | 10090 | /* Destroy runqueue etc associated with a task group */ |
4cf86d77 | 10091 | void sched_destroy_group(struct task_group *tg) |
29f59db3 | 10092 | { |
8ed36996 | 10093 | unsigned long flags; |
9b5b7751 | 10094 | int i; |
29f59db3 | 10095 | |
8ed36996 | 10096 | spin_lock_irqsave(&task_group_lock, flags); |
9b5b7751 | 10097 | for_each_possible_cpu(i) { |
bccbe08a PZ |
10098 | unregister_fair_sched_group(tg, i); |
10099 | unregister_rt_sched_group(tg, i); | |
9b5b7751 | 10100 | } |
6f505b16 | 10101 | list_del_rcu(&tg->list); |
f473aa5e | 10102 | list_del_rcu(&tg->siblings); |
8ed36996 | 10103 | spin_unlock_irqrestore(&task_group_lock, flags); |
9b5b7751 | 10104 | |
9b5b7751 | 10105 | /* wait for possible concurrent references to cfs_rqs complete */ |
6f505b16 | 10106 | call_rcu(&tg->rcu, free_sched_group_rcu); |
29f59db3 SV |
10107 | } |
10108 | ||
9b5b7751 | 10109 | /* change task's runqueue when it moves between groups. |
3a252015 IM |
10110 | * The caller of this function should have put the task in its new group |
10111 | * by now. This function just updates tsk->se.cfs_rq and tsk->se.parent to | |
10112 | * reflect its new group. | |
9b5b7751 SV |
10113 | */ |
10114 | void sched_move_task(struct task_struct *tsk) | |
29f59db3 SV |
10115 | { |
10116 | int on_rq, running; | |
10117 | unsigned long flags; | |
10118 | struct rq *rq; | |
10119 | ||
10120 | rq = task_rq_lock(tsk, &flags); | |
10121 | ||
29f59db3 SV |
10122 | update_rq_clock(rq); |
10123 | ||
051a1d1a | 10124 | running = task_current(rq, tsk); |
29f59db3 SV |
10125 | on_rq = tsk->se.on_rq; |
10126 | ||
0e1f3483 | 10127 | if (on_rq) |
29f59db3 | 10128 | dequeue_task(rq, tsk, 0); |
0e1f3483 HS |
10129 | if (unlikely(running)) |
10130 | tsk->sched_class->put_prev_task(rq, tsk); | |
29f59db3 | 10131 | |
6f505b16 | 10132 | set_task_rq(tsk, task_cpu(tsk)); |
29f59db3 | 10133 | |
810b3817 PZ |
10134 | #ifdef CONFIG_FAIR_GROUP_SCHED |
10135 | if (tsk->sched_class->moved_group) | |
88ec22d3 | 10136 | tsk->sched_class->moved_group(tsk, on_rq); |
810b3817 PZ |
10137 | #endif |
10138 | ||
0e1f3483 HS |
10139 | if (unlikely(running)) |
10140 | tsk->sched_class->set_curr_task(rq); | |
10141 | if (on_rq) | |
7074badb | 10142 | enqueue_task(rq, tsk, 0); |
29f59db3 | 10143 | |
29f59db3 SV |
10144 | task_rq_unlock(rq, &flags); |
10145 | } | |
6d6bc0ad | 10146 | #endif /* CONFIG_GROUP_SCHED */ |
29f59db3 | 10147 | |
052f1dc7 | 10148 | #ifdef CONFIG_FAIR_GROUP_SCHED |
c09595f6 | 10149 | static void __set_se_shares(struct sched_entity *se, unsigned long shares) |
29f59db3 SV |
10150 | { |
10151 | struct cfs_rq *cfs_rq = se->cfs_rq; | |
29f59db3 SV |
10152 | int on_rq; |
10153 | ||
29f59db3 | 10154 | on_rq = se->on_rq; |
62fb1851 | 10155 | if (on_rq) |
29f59db3 SV |
10156 | dequeue_entity(cfs_rq, se, 0); |
10157 | ||
10158 | se->load.weight = shares; | |
e05510d0 | 10159 | se->load.inv_weight = 0; |
29f59db3 | 10160 | |
62fb1851 | 10161 | if (on_rq) |
29f59db3 | 10162 | enqueue_entity(cfs_rq, se, 0); |
c09595f6 | 10163 | } |
62fb1851 | 10164 | |
c09595f6 PZ |
10165 | static void set_se_shares(struct sched_entity *se, unsigned long shares) |
10166 | { | |
10167 | struct cfs_rq *cfs_rq = se->cfs_rq; | |
10168 | struct rq *rq = cfs_rq->rq; | |
10169 | unsigned long flags; | |
10170 | ||
05fa785c | 10171 | raw_spin_lock_irqsave(&rq->lock, flags); |
c09595f6 | 10172 | __set_se_shares(se, shares); |
05fa785c | 10173 | raw_spin_unlock_irqrestore(&rq->lock, flags); |
29f59db3 SV |
10174 | } |
10175 | ||
8ed36996 PZ |
10176 | static DEFINE_MUTEX(shares_mutex); |
10177 | ||
4cf86d77 | 10178 | int sched_group_set_shares(struct task_group *tg, unsigned long shares) |
29f59db3 SV |
10179 | { |
10180 | int i; | |
8ed36996 | 10181 | unsigned long flags; |
c61935fd | 10182 | |
ec7dc8ac DG |
10183 | /* |
10184 | * We can't change the weight of the root cgroup. | |
10185 | */ | |
10186 | if (!tg->se[0]) | |
10187 | return -EINVAL; | |
10188 | ||
18d95a28 PZ |
10189 | if (shares < MIN_SHARES) |
10190 | shares = MIN_SHARES; | |
cb4ad1ff MX |
10191 | else if (shares > MAX_SHARES) |
10192 | shares = MAX_SHARES; | |
62fb1851 | 10193 | |
8ed36996 | 10194 | mutex_lock(&shares_mutex); |
9b5b7751 | 10195 | if (tg->shares == shares) |
5cb350ba | 10196 | goto done; |
29f59db3 | 10197 | |
8ed36996 | 10198 | spin_lock_irqsave(&task_group_lock, flags); |
bccbe08a PZ |
10199 | for_each_possible_cpu(i) |
10200 | unregister_fair_sched_group(tg, i); | |
f473aa5e | 10201 | list_del_rcu(&tg->siblings); |
8ed36996 | 10202 | spin_unlock_irqrestore(&task_group_lock, flags); |
6b2d7700 SV |
10203 | |
10204 | /* wait for any ongoing reference to this group to finish */ | |
10205 | synchronize_sched(); | |
10206 | ||
10207 | /* | |
10208 | * Now we are free to modify the group's share on each cpu | |
10209 | * w/o tripping rebalance_share or load_balance_fair. | |
10210 | */ | |
9b5b7751 | 10211 | tg->shares = shares; |
c09595f6 PZ |
10212 | for_each_possible_cpu(i) { |
10213 | /* | |
10214 | * force a rebalance | |
10215 | */ | |
10216 | cfs_rq_set_shares(tg->cfs_rq[i], 0); | |
cb4ad1ff | 10217 | set_se_shares(tg->se[i], shares); |
c09595f6 | 10218 | } |
29f59db3 | 10219 | |
6b2d7700 SV |
10220 | /* |
10221 | * Enable load balance activity on this group, by inserting it back on | |
10222 | * each cpu's rq->leaf_cfs_rq_list. | |
10223 | */ | |
8ed36996 | 10224 | spin_lock_irqsave(&task_group_lock, flags); |
bccbe08a PZ |
10225 | for_each_possible_cpu(i) |
10226 | register_fair_sched_group(tg, i); | |
f473aa5e | 10227 | list_add_rcu(&tg->siblings, &tg->parent->children); |
8ed36996 | 10228 | spin_unlock_irqrestore(&task_group_lock, flags); |
5cb350ba | 10229 | done: |
8ed36996 | 10230 | mutex_unlock(&shares_mutex); |
9b5b7751 | 10231 | return 0; |
29f59db3 SV |
10232 | } |
10233 | ||
5cb350ba DG |
10234 | unsigned long sched_group_shares(struct task_group *tg) |
10235 | { | |
10236 | return tg->shares; | |
10237 | } | |
052f1dc7 | 10238 | #endif |
5cb350ba | 10239 | |
052f1dc7 | 10240 | #ifdef CONFIG_RT_GROUP_SCHED |
6f505b16 | 10241 | /* |
9f0c1e56 | 10242 | * Ensure that the real time constraints are schedulable. |
6f505b16 | 10243 | */ |
9f0c1e56 PZ |
10244 | static DEFINE_MUTEX(rt_constraints_mutex); |
10245 | ||
10246 | static unsigned long to_ratio(u64 period, u64 runtime) | |
10247 | { | |
10248 | if (runtime == RUNTIME_INF) | |
9a7e0b18 | 10249 | return 1ULL << 20; |
9f0c1e56 | 10250 | |
9a7e0b18 | 10251 | return div64_u64(runtime << 20, period); |
9f0c1e56 PZ |
10252 | } |
10253 | ||
9a7e0b18 PZ |
10254 | /* Must be called with tasklist_lock held */ |
10255 | static inline int tg_has_rt_tasks(struct task_group *tg) | |
b40b2e8e | 10256 | { |
9a7e0b18 | 10257 | struct task_struct *g, *p; |
b40b2e8e | 10258 | |
9a7e0b18 PZ |
10259 | do_each_thread(g, p) { |
10260 | if (rt_task(p) && rt_rq_of_se(&p->rt)->tg == tg) | |
10261 | return 1; | |
10262 | } while_each_thread(g, p); | |
b40b2e8e | 10263 | |
9a7e0b18 PZ |
10264 | return 0; |
10265 | } | |
b40b2e8e | 10266 | |
9a7e0b18 PZ |
10267 | struct rt_schedulable_data { |
10268 | struct task_group *tg; | |
10269 | u64 rt_period; | |
10270 | u64 rt_runtime; | |
10271 | }; | |
b40b2e8e | 10272 | |
9a7e0b18 PZ |
10273 | static int tg_schedulable(struct task_group *tg, void *data) |
10274 | { | |
10275 | struct rt_schedulable_data *d = data; | |
10276 | struct task_group *child; | |
10277 | unsigned long total, sum = 0; | |
10278 | u64 period, runtime; | |
b40b2e8e | 10279 | |
9a7e0b18 PZ |
10280 | period = ktime_to_ns(tg->rt_bandwidth.rt_period); |
10281 | runtime = tg->rt_bandwidth.rt_runtime; | |
b40b2e8e | 10282 | |
9a7e0b18 PZ |
10283 | if (tg == d->tg) { |
10284 | period = d->rt_period; | |
10285 | runtime = d->rt_runtime; | |
b40b2e8e | 10286 | } |
b40b2e8e | 10287 | |
98a4826b PZ |
10288 | #ifdef CONFIG_USER_SCHED |
10289 | if (tg == &root_task_group) { | |
10290 | period = global_rt_period(); | |
10291 | runtime = global_rt_runtime(); | |
10292 | } | |
10293 | #endif | |
10294 | ||
4653f803 PZ |
10295 | /* |
10296 | * Cannot have more runtime than the period. | |
10297 | */ | |
10298 | if (runtime > period && runtime != RUNTIME_INF) | |
10299 | return -EINVAL; | |
6f505b16 | 10300 | |
4653f803 PZ |
10301 | /* |
10302 | * Ensure we don't starve existing RT tasks. | |
10303 | */ | |
9a7e0b18 PZ |
10304 | if (rt_bandwidth_enabled() && !runtime && tg_has_rt_tasks(tg)) |
10305 | return -EBUSY; | |
6f505b16 | 10306 | |
9a7e0b18 | 10307 | total = to_ratio(period, runtime); |
6f505b16 | 10308 | |
4653f803 PZ |
10309 | /* |
10310 | * Nobody can have more than the global setting allows. | |
10311 | */ | |
10312 | if (total > to_ratio(global_rt_period(), global_rt_runtime())) | |
10313 | return -EINVAL; | |
6f505b16 | 10314 | |
4653f803 PZ |
10315 | /* |
10316 | * The sum of our children's runtime should not exceed our own. | |
10317 | */ | |
9a7e0b18 PZ |
10318 | list_for_each_entry_rcu(child, &tg->children, siblings) { |
10319 | period = ktime_to_ns(child->rt_bandwidth.rt_period); | |
10320 | runtime = child->rt_bandwidth.rt_runtime; | |
6f505b16 | 10321 | |
9a7e0b18 PZ |
10322 | if (child == d->tg) { |
10323 | period = d->rt_period; | |
10324 | runtime = d->rt_runtime; | |
10325 | } | |
6f505b16 | 10326 | |
9a7e0b18 | 10327 | sum += to_ratio(period, runtime); |
9f0c1e56 | 10328 | } |
6f505b16 | 10329 | |
9a7e0b18 PZ |
10330 | if (sum > total) |
10331 | return -EINVAL; | |
10332 | ||
10333 | return 0; | |
6f505b16 PZ |
10334 | } |
10335 | ||
9a7e0b18 | 10336 | static int __rt_schedulable(struct task_group *tg, u64 period, u64 runtime) |
521f1a24 | 10337 | { |
9a7e0b18 PZ |
10338 | struct rt_schedulable_data data = { |
10339 | .tg = tg, | |
10340 | .rt_period = period, | |
10341 | .rt_runtime = runtime, | |
10342 | }; | |
10343 | ||
10344 | return walk_tg_tree(tg_schedulable, tg_nop, &data); | |
521f1a24 DG |
10345 | } |
10346 | ||
d0b27fa7 PZ |
10347 | static int tg_set_bandwidth(struct task_group *tg, |
10348 | u64 rt_period, u64 rt_runtime) | |
6f505b16 | 10349 | { |
ac086bc2 | 10350 | int i, err = 0; |
9f0c1e56 | 10351 | |
9f0c1e56 | 10352 | mutex_lock(&rt_constraints_mutex); |
521f1a24 | 10353 | read_lock(&tasklist_lock); |
9a7e0b18 PZ |
10354 | err = __rt_schedulable(tg, rt_period, rt_runtime); |
10355 | if (err) | |
9f0c1e56 | 10356 | goto unlock; |
ac086bc2 | 10357 | |
0986b11b | 10358 | raw_spin_lock_irq(&tg->rt_bandwidth.rt_runtime_lock); |
d0b27fa7 PZ |
10359 | tg->rt_bandwidth.rt_period = ns_to_ktime(rt_period); |
10360 | tg->rt_bandwidth.rt_runtime = rt_runtime; | |
ac086bc2 PZ |
10361 | |
10362 | for_each_possible_cpu(i) { | |
10363 | struct rt_rq *rt_rq = tg->rt_rq[i]; | |
10364 | ||
0986b11b | 10365 | raw_spin_lock(&rt_rq->rt_runtime_lock); |
ac086bc2 | 10366 | rt_rq->rt_runtime = rt_runtime; |
0986b11b | 10367 | raw_spin_unlock(&rt_rq->rt_runtime_lock); |
ac086bc2 | 10368 | } |
0986b11b | 10369 | raw_spin_unlock_irq(&tg->rt_bandwidth.rt_runtime_lock); |
9f0c1e56 | 10370 | unlock: |
521f1a24 | 10371 | read_unlock(&tasklist_lock); |
9f0c1e56 PZ |
10372 | mutex_unlock(&rt_constraints_mutex); |
10373 | ||
10374 | return err; | |
6f505b16 PZ |
10375 | } |
10376 | ||
d0b27fa7 PZ |
10377 | int sched_group_set_rt_runtime(struct task_group *tg, long rt_runtime_us) |
10378 | { | |
10379 | u64 rt_runtime, rt_period; | |
10380 | ||
10381 | rt_period = ktime_to_ns(tg->rt_bandwidth.rt_period); | |
10382 | rt_runtime = (u64)rt_runtime_us * NSEC_PER_USEC; | |
10383 | if (rt_runtime_us < 0) | |
10384 | rt_runtime = RUNTIME_INF; | |
10385 | ||
10386 | return tg_set_bandwidth(tg, rt_period, rt_runtime); | |
10387 | } | |
10388 | ||
9f0c1e56 PZ |
10389 | long sched_group_rt_runtime(struct task_group *tg) |
10390 | { | |
10391 | u64 rt_runtime_us; | |
10392 | ||
d0b27fa7 | 10393 | if (tg->rt_bandwidth.rt_runtime == RUNTIME_INF) |
9f0c1e56 PZ |
10394 | return -1; |
10395 | ||
d0b27fa7 | 10396 | rt_runtime_us = tg->rt_bandwidth.rt_runtime; |
9f0c1e56 PZ |
10397 | do_div(rt_runtime_us, NSEC_PER_USEC); |
10398 | return rt_runtime_us; | |
10399 | } | |
d0b27fa7 PZ |
10400 | |
10401 | int sched_group_set_rt_period(struct task_group *tg, long rt_period_us) | |
10402 | { | |
10403 | u64 rt_runtime, rt_period; | |
10404 | ||
10405 | rt_period = (u64)rt_period_us * NSEC_PER_USEC; | |
10406 | rt_runtime = tg->rt_bandwidth.rt_runtime; | |
10407 | ||
619b0488 R |
10408 | if (rt_period == 0) |
10409 | return -EINVAL; | |
10410 | ||
d0b27fa7 PZ |
10411 | return tg_set_bandwidth(tg, rt_period, rt_runtime); |
10412 | } | |
10413 | ||
10414 | long sched_group_rt_period(struct task_group *tg) | |
10415 | { | |
10416 | u64 rt_period_us; | |
10417 | ||
10418 | rt_period_us = ktime_to_ns(tg->rt_bandwidth.rt_period); | |
10419 | do_div(rt_period_us, NSEC_PER_USEC); | |
10420 | return rt_period_us; | |
10421 | } | |
10422 | ||
10423 | static int sched_rt_global_constraints(void) | |
10424 | { | |
4653f803 | 10425 | u64 runtime, period; |
d0b27fa7 PZ |
10426 | int ret = 0; |
10427 | ||
ec5d4989 HS |
10428 | if (sysctl_sched_rt_period <= 0) |
10429 | return -EINVAL; | |
10430 | ||
4653f803 PZ |
10431 | runtime = global_rt_runtime(); |
10432 | period = global_rt_period(); | |
10433 | ||
10434 | /* | |
10435 | * Sanity check on the sysctl variables. | |
10436 | */ | |
10437 | if (runtime > period && runtime != RUNTIME_INF) | |
10438 | return -EINVAL; | |
10b612f4 | 10439 | |
d0b27fa7 | 10440 | mutex_lock(&rt_constraints_mutex); |
9a7e0b18 | 10441 | read_lock(&tasklist_lock); |
4653f803 | 10442 | ret = __rt_schedulable(NULL, 0, 0); |
9a7e0b18 | 10443 | read_unlock(&tasklist_lock); |
d0b27fa7 PZ |
10444 | mutex_unlock(&rt_constraints_mutex); |
10445 | ||
10446 | return ret; | |
10447 | } | |
54e99124 DG |
10448 | |
10449 | int sched_rt_can_attach(struct task_group *tg, struct task_struct *tsk) | |
10450 | { | |
10451 | /* Don't accept realtime tasks when there is no way for them to run */ | |
10452 | if (rt_task(tsk) && tg->rt_bandwidth.rt_runtime == 0) | |
10453 | return 0; | |
10454 | ||
10455 | return 1; | |
10456 | } | |
10457 | ||
6d6bc0ad | 10458 | #else /* !CONFIG_RT_GROUP_SCHED */ |
d0b27fa7 PZ |
10459 | static int sched_rt_global_constraints(void) |
10460 | { | |
ac086bc2 PZ |
10461 | unsigned long flags; |
10462 | int i; | |
10463 | ||
ec5d4989 HS |
10464 | if (sysctl_sched_rt_period <= 0) |
10465 | return -EINVAL; | |
10466 | ||
60aa605d PZ |
10467 | /* |
10468 | * There's always some RT tasks in the root group | |
10469 | * -- migration, kstopmachine etc.. | |
10470 | */ | |
10471 | if (sysctl_sched_rt_runtime == 0) | |
10472 | return -EBUSY; | |
10473 | ||
0986b11b | 10474 | raw_spin_lock_irqsave(&def_rt_bandwidth.rt_runtime_lock, flags); |
ac086bc2 PZ |
10475 | for_each_possible_cpu(i) { |
10476 | struct rt_rq *rt_rq = &cpu_rq(i)->rt; | |
10477 | ||
0986b11b | 10478 | raw_spin_lock(&rt_rq->rt_runtime_lock); |
ac086bc2 | 10479 | rt_rq->rt_runtime = global_rt_runtime(); |
0986b11b | 10480 | raw_spin_unlock(&rt_rq->rt_runtime_lock); |
ac086bc2 | 10481 | } |
0986b11b | 10482 | raw_spin_unlock_irqrestore(&def_rt_bandwidth.rt_runtime_lock, flags); |
ac086bc2 | 10483 | |
d0b27fa7 PZ |
10484 | return 0; |
10485 | } | |
6d6bc0ad | 10486 | #endif /* CONFIG_RT_GROUP_SCHED */ |
d0b27fa7 PZ |
10487 | |
10488 | int sched_rt_handler(struct ctl_table *table, int write, | |
8d65af78 | 10489 | void __user *buffer, size_t *lenp, |
d0b27fa7 PZ |
10490 | loff_t *ppos) |
10491 | { | |
10492 | int ret; | |
10493 | int old_period, old_runtime; | |
10494 | static DEFINE_MUTEX(mutex); | |
10495 | ||
10496 | mutex_lock(&mutex); | |
10497 | old_period = sysctl_sched_rt_period; | |
10498 | old_runtime = sysctl_sched_rt_runtime; | |
10499 | ||
8d65af78 | 10500 | ret = proc_dointvec(table, write, buffer, lenp, ppos); |
d0b27fa7 PZ |
10501 | |
10502 | if (!ret && write) { | |
10503 | ret = sched_rt_global_constraints(); | |
10504 | if (ret) { | |
10505 | sysctl_sched_rt_period = old_period; | |
10506 | sysctl_sched_rt_runtime = old_runtime; | |
10507 | } else { | |
10508 | def_rt_bandwidth.rt_runtime = global_rt_runtime(); | |
10509 | def_rt_bandwidth.rt_period = | |
10510 | ns_to_ktime(global_rt_period()); | |
10511 | } | |
10512 | } | |
10513 | mutex_unlock(&mutex); | |
10514 | ||
10515 | return ret; | |
10516 | } | |
68318b8e | 10517 | |
052f1dc7 | 10518 | #ifdef CONFIG_CGROUP_SCHED |
68318b8e SV |
10519 | |
10520 | /* return corresponding task_group object of a cgroup */ | |
2b01dfe3 | 10521 | static inline struct task_group *cgroup_tg(struct cgroup *cgrp) |
68318b8e | 10522 | { |
2b01dfe3 PM |
10523 | return container_of(cgroup_subsys_state(cgrp, cpu_cgroup_subsys_id), |
10524 | struct task_group, css); | |
68318b8e SV |
10525 | } |
10526 | ||
10527 | static struct cgroup_subsys_state * | |
2b01dfe3 | 10528 | cpu_cgroup_create(struct cgroup_subsys *ss, struct cgroup *cgrp) |
68318b8e | 10529 | { |
ec7dc8ac | 10530 | struct task_group *tg, *parent; |
68318b8e | 10531 | |
2b01dfe3 | 10532 | if (!cgrp->parent) { |
68318b8e | 10533 | /* This is early initialization for the top cgroup */ |
68318b8e SV |
10534 | return &init_task_group.css; |
10535 | } | |
10536 | ||
ec7dc8ac DG |
10537 | parent = cgroup_tg(cgrp->parent); |
10538 | tg = sched_create_group(parent); | |
68318b8e SV |
10539 | if (IS_ERR(tg)) |
10540 | return ERR_PTR(-ENOMEM); | |
10541 | ||
68318b8e SV |
10542 | return &tg->css; |
10543 | } | |
10544 | ||
41a2d6cf IM |
10545 | static void |
10546 | cpu_cgroup_destroy(struct cgroup_subsys *ss, struct cgroup *cgrp) | |
68318b8e | 10547 | { |
2b01dfe3 | 10548 | struct task_group *tg = cgroup_tg(cgrp); |
68318b8e SV |
10549 | |
10550 | sched_destroy_group(tg); | |
10551 | } | |
10552 | ||
41a2d6cf | 10553 | static int |
be367d09 | 10554 | cpu_cgroup_can_attach_task(struct cgroup *cgrp, struct task_struct *tsk) |
68318b8e | 10555 | { |
b68aa230 | 10556 | #ifdef CONFIG_RT_GROUP_SCHED |
54e99124 | 10557 | if (!sched_rt_can_attach(cgroup_tg(cgrp), tsk)) |
b68aa230 PZ |
10558 | return -EINVAL; |
10559 | #else | |
68318b8e SV |
10560 | /* We don't support RT-tasks being in separate groups */ |
10561 | if (tsk->sched_class != &fair_sched_class) | |
10562 | return -EINVAL; | |
b68aa230 | 10563 | #endif |
be367d09 BB |
10564 | return 0; |
10565 | } | |
68318b8e | 10566 | |
be367d09 BB |
10567 | static int |
10568 | cpu_cgroup_can_attach(struct cgroup_subsys *ss, struct cgroup *cgrp, | |
10569 | struct task_struct *tsk, bool threadgroup) | |
10570 | { | |
10571 | int retval = cpu_cgroup_can_attach_task(cgrp, tsk); | |
10572 | if (retval) | |
10573 | return retval; | |
10574 | if (threadgroup) { | |
10575 | struct task_struct *c; | |
10576 | rcu_read_lock(); | |
10577 | list_for_each_entry_rcu(c, &tsk->thread_group, thread_group) { | |
10578 | retval = cpu_cgroup_can_attach_task(cgrp, c); | |
10579 | if (retval) { | |
10580 | rcu_read_unlock(); | |
10581 | return retval; | |
10582 | } | |
10583 | } | |
10584 | rcu_read_unlock(); | |
10585 | } | |
68318b8e SV |
10586 | return 0; |
10587 | } | |
10588 | ||
10589 | static void | |
2b01dfe3 | 10590 | cpu_cgroup_attach(struct cgroup_subsys *ss, struct cgroup *cgrp, |
be367d09 BB |
10591 | struct cgroup *old_cont, struct task_struct *tsk, |
10592 | bool threadgroup) | |
68318b8e SV |
10593 | { |
10594 | sched_move_task(tsk); | |
be367d09 BB |
10595 | if (threadgroup) { |
10596 | struct task_struct *c; | |
10597 | rcu_read_lock(); | |
10598 | list_for_each_entry_rcu(c, &tsk->thread_group, thread_group) { | |
10599 | sched_move_task(c); | |
10600 | } | |
10601 | rcu_read_unlock(); | |
10602 | } | |
68318b8e SV |
10603 | } |
10604 | ||
052f1dc7 | 10605 | #ifdef CONFIG_FAIR_GROUP_SCHED |
f4c753b7 | 10606 | static int cpu_shares_write_u64(struct cgroup *cgrp, struct cftype *cftype, |
2b01dfe3 | 10607 | u64 shareval) |
68318b8e | 10608 | { |
2b01dfe3 | 10609 | return sched_group_set_shares(cgroup_tg(cgrp), shareval); |
68318b8e SV |
10610 | } |
10611 | ||
f4c753b7 | 10612 | static u64 cpu_shares_read_u64(struct cgroup *cgrp, struct cftype *cft) |
68318b8e | 10613 | { |
2b01dfe3 | 10614 | struct task_group *tg = cgroup_tg(cgrp); |
68318b8e SV |
10615 | |
10616 | return (u64) tg->shares; | |
10617 | } | |
6d6bc0ad | 10618 | #endif /* CONFIG_FAIR_GROUP_SCHED */ |
68318b8e | 10619 | |
052f1dc7 | 10620 | #ifdef CONFIG_RT_GROUP_SCHED |
0c70814c | 10621 | static int cpu_rt_runtime_write(struct cgroup *cgrp, struct cftype *cft, |
06ecb27c | 10622 | s64 val) |
6f505b16 | 10623 | { |
06ecb27c | 10624 | return sched_group_set_rt_runtime(cgroup_tg(cgrp), val); |
6f505b16 PZ |
10625 | } |
10626 | ||
06ecb27c | 10627 | static s64 cpu_rt_runtime_read(struct cgroup *cgrp, struct cftype *cft) |
6f505b16 | 10628 | { |
06ecb27c | 10629 | return sched_group_rt_runtime(cgroup_tg(cgrp)); |
6f505b16 | 10630 | } |
d0b27fa7 PZ |
10631 | |
10632 | static int cpu_rt_period_write_uint(struct cgroup *cgrp, struct cftype *cftype, | |
10633 | u64 rt_period_us) | |
10634 | { | |
10635 | return sched_group_set_rt_period(cgroup_tg(cgrp), rt_period_us); | |
10636 | } | |
10637 | ||
10638 | static u64 cpu_rt_period_read_uint(struct cgroup *cgrp, struct cftype *cft) | |
10639 | { | |
10640 | return sched_group_rt_period(cgroup_tg(cgrp)); | |
10641 | } | |
6d6bc0ad | 10642 | #endif /* CONFIG_RT_GROUP_SCHED */ |
6f505b16 | 10643 | |
fe5c7cc2 | 10644 | static struct cftype cpu_files[] = { |
052f1dc7 | 10645 | #ifdef CONFIG_FAIR_GROUP_SCHED |
fe5c7cc2 PM |
10646 | { |
10647 | .name = "shares", | |
f4c753b7 PM |
10648 | .read_u64 = cpu_shares_read_u64, |
10649 | .write_u64 = cpu_shares_write_u64, | |
fe5c7cc2 | 10650 | }, |
052f1dc7 PZ |
10651 | #endif |
10652 | #ifdef CONFIG_RT_GROUP_SCHED | |
6f505b16 | 10653 | { |
9f0c1e56 | 10654 | .name = "rt_runtime_us", |
06ecb27c PM |
10655 | .read_s64 = cpu_rt_runtime_read, |
10656 | .write_s64 = cpu_rt_runtime_write, | |
6f505b16 | 10657 | }, |
d0b27fa7 PZ |
10658 | { |
10659 | .name = "rt_period_us", | |
f4c753b7 PM |
10660 | .read_u64 = cpu_rt_period_read_uint, |
10661 | .write_u64 = cpu_rt_period_write_uint, | |
d0b27fa7 | 10662 | }, |
052f1dc7 | 10663 | #endif |
68318b8e SV |
10664 | }; |
10665 | ||
10666 | static int cpu_cgroup_populate(struct cgroup_subsys *ss, struct cgroup *cont) | |
10667 | { | |
fe5c7cc2 | 10668 | return cgroup_add_files(cont, ss, cpu_files, ARRAY_SIZE(cpu_files)); |
68318b8e SV |
10669 | } |
10670 | ||
10671 | struct cgroup_subsys cpu_cgroup_subsys = { | |
38605cae IM |
10672 | .name = "cpu", |
10673 | .create = cpu_cgroup_create, | |
10674 | .destroy = cpu_cgroup_destroy, | |
10675 | .can_attach = cpu_cgroup_can_attach, | |
10676 | .attach = cpu_cgroup_attach, | |
10677 | .populate = cpu_cgroup_populate, | |
10678 | .subsys_id = cpu_cgroup_subsys_id, | |
68318b8e SV |
10679 | .early_init = 1, |
10680 | }; | |
10681 | ||
052f1dc7 | 10682 | #endif /* CONFIG_CGROUP_SCHED */ |
d842de87 SV |
10683 | |
10684 | #ifdef CONFIG_CGROUP_CPUACCT | |
10685 | ||
10686 | /* | |
10687 | * CPU accounting code for task groups. | |
10688 | * | |
10689 | * Based on the work by Paul Menage (menage@google.com) and Balbir Singh | |
10690 | * (balbir@in.ibm.com). | |
10691 | */ | |
10692 | ||
934352f2 | 10693 | /* track cpu usage of a group of tasks and its child groups */ |
d842de87 SV |
10694 | struct cpuacct { |
10695 | struct cgroup_subsys_state css; | |
10696 | /* cpuusage holds pointer to a u64-type object on every cpu */ | |
10697 | u64 *cpuusage; | |
ef12fefa | 10698 | struct percpu_counter cpustat[CPUACCT_STAT_NSTATS]; |
934352f2 | 10699 | struct cpuacct *parent; |
d842de87 SV |
10700 | }; |
10701 | ||
10702 | struct cgroup_subsys cpuacct_subsys; | |
10703 | ||
10704 | /* return cpu accounting group corresponding to this container */ | |
32cd756a | 10705 | static inline struct cpuacct *cgroup_ca(struct cgroup *cgrp) |
d842de87 | 10706 | { |
32cd756a | 10707 | return container_of(cgroup_subsys_state(cgrp, cpuacct_subsys_id), |
d842de87 SV |
10708 | struct cpuacct, css); |
10709 | } | |
10710 | ||
10711 | /* return cpu accounting group to which this task belongs */ | |
10712 | static inline struct cpuacct *task_ca(struct task_struct *tsk) | |
10713 | { | |
10714 | return container_of(task_subsys_state(tsk, cpuacct_subsys_id), | |
10715 | struct cpuacct, css); | |
10716 | } | |
10717 | ||
10718 | /* create a new cpu accounting group */ | |
10719 | static struct cgroup_subsys_state *cpuacct_create( | |
32cd756a | 10720 | struct cgroup_subsys *ss, struct cgroup *cgrp) |
d842de87 SV |
10721 | { |
10722 | struct cpuacct *ca = kzalloc(sizeof(*ca), GFP_KERNEL); | |
ef12fefa | 10723 | int i; |
d842de87 SV |
10724 | |
10725 | if (!ca) | |
ef12fefa | 10726 | goto out; |
d842de87 SV |
10727 | |
10728 | ca->cpuusage = alloc_percpu(u64); | |
ef12fefa BR |
10729 | if (!ca->cpuusage) |
10730 | goto out_free_ca; | |
10731 | ||
10732 | for (i = 0; i < CPUACCT_STAT_NSTATS; i++) | |
10733 | if (percpu_counter_init(&ca->cpustat[i], 0)) | |
10734 | goto out_free_counters; | |
d842de87 | 10735 | |
934352f2 BR |
10736 | if (cgrp->parent) |
10737 | ca->parent = cgroup_ca(cgrp->parent); | |
10738 | ||
d842de87 | 10739 | return &ca->css; |
ef12fefa BR |
10740 | |
10741 | out_free_counters: | |
10742 | while (--i >= 0) | |
10743 | percpu_counter_destroy(&ca->cpustat[i]); | |
10744 | free_percpu(ca->cpuusage); | |
10745 | out_free_ca: | |
10746 | kfree(ca); | |
10747 | out: | |
10748 | return ERR_PTR(-ENOMEM); | |
d842de87 SV |
10749 | } |
10750 | ||
10751 | /* destroy an existing cpu accounting group */ | |
41a2d6cf | 10752 | static void |
32cd756a | 10753 | cpuacct_destroy(struct cgroup_subsys *ss, struct cgroup *cgrp) |
d842de87 | 10754 | { |
32cd756a | 10755 | struct cpuacct *ca = cgroup_ca(cgrp); |
ef12fefa | 10756 | int i; |
d842de87 | 10757 | |
ef12fefa BR |
10758 | for (i = 0; i < CPUACCT_STAT_NSTATS; i++) |
10759 | percpu_counter_destroy(&ca->cpustat[i]); | |
d842de87 SV |
10760 | free_percpu(ca->cpuusage); |
10761 | kfree(ca); | |
10762 | } | |
10763 | ||
720f5498 KC |
10764 | static u64 cpuacct_cpuusage_read(struct cpuacct *ca, int cpu) |
10765 | { | |
b36128c8 | 10766 | u64 *cpuusage = per_cpu_ptr(ca->cpuusage, cpu); |
720f5498 KC |
10767 | u64 data; |
10768 | ||
10769 | #ifndef CONFIG_64BIT | |
10770 | /* | |
10771 | * Take rq->lock to make 64-bit read safe on 32-bit platforms. | |
10772 | */ | |
05fa785c | 10773 | raw_spin_lock_irq(&cpu_rq(cpu)->lock); |
720f5498 | 10774 | data = *cpuusage; |
05fa785c | 10775 | raw_spin_unlock_irq(&cpu_rq(cpu)->lock); |
720f5498 KC |
10776 | #else |
10777 | data = *cpuusage; | |
10778 | #endif | |
10779 | ||
10780 | return data; | |
10781 | } | |
10782 | ||
10783 | static void cpuacct_cpuusage_write(struct cpuacct *ca, int cpu, u64 val) | |
10784 | { | |
b36128c8 | 10785 | u64 *cpuusage = per_cpu_ptr(ca->cpuusage, cpu); |
720f5498 KC |
10786 | |
10787 | #ifndef CONFIG_64BIT | |
10788 | /* | |
10789 | * Take rq->lock to make 64-bit write safe on 32-bit platforms. | |
10790 | */ | |
05fa785c | 10791 | raw_spin_lock_irq(&cpu_rq(cpu)->lock); |
720f5498 | 10792 | *cpuusage = val; |
05fa785c | 10793 | raw_spin_unlock_irq(&cpu_rq(cpu)->lock); |
720f5498 KC |
10794 | #else |
10795 | *cpuusage = val; | |
10796 | #endif | |
10797 | } | |
10798 | ||
d842de87 | 10799 | /* return total cpu usage (in nanoseconds) of a group */ |
32cd756a | 10800 | static u64 cpuusage_read(struct cgroup *cgrp, struct cftype *cft) |
d842de87 | 10801 | { |
32cd756a | 10802 | struct cpuacct *ca = cgroup_ca(cgrp); |
d842de87 SV |
10803 | u64 totalcpuusage = 0; |
10804 | int i; | |
10805 | ||
720f5498 KC |
10806 | for_each_present_cpu(i) |
10807 | totalcpuusage += cpuacct_cpuusage_read(ca, i); | |
d842de87 SV |
10808 | |
10809 | return totalcpuusage; | |
10810 | } | |
10811 | ||
0297b803 DG |
10812 | static int cpuusage_write(struct cgroup *cgrp, struct cftype *cftype, |
10813 | u64 reset) | |
10814 | { | |
10815 | struct cpuacct *ca = cgroup_ca(cgrp); | |
10816 | int err = 0; | |
10817 | int i; | |
10818 | ||
10819 | if (reset) { | |
10820 | err = -EINVAL; | |
10821 | goto out; | |
10822 | } | |
10823 | ||
720f5498 KC |
10824 | for_each_present_cpu(i) |
10825 | cpuacct_cpuusage_write(ca, i, 0); | |
0297b803 | 10826 | |
0297b803 DG |
10827 | out: |
10828 | return err; | |
10829 | } | |
10830 | ||
e9515c3c KC |
10831 | static int cpuacct_percpu_seq_read(struct cgroup *cgroup, struct cftype *cft, |
10832 | struct seq_file *m) | |
10833 | { | |
10834 | struct cpuacct *ca = cgroup_ca(cgroup); | |
10835 | u64 percpu; | |
10836 | int i; | |
10837 | ||
10838 | for_each_present_cpu(i) { | |
10839 | percpu = cpuacct_cpuusage_read(ca, i); | |
10840 | seq_printf(m, "%llu ", (unsigned long long) percpu); | |
10841 | } | |
10842 | seq_printf(m, "\n"); | |
10843 | return 0; | |
10844 | } | |
10845 | ||
ef12fefa BR |
10846 | static const char *cpuacct_stat_desc[] = { |
10847 | [CPUACCT_STAT_USER] = "user", | |
10848 | [CPUACCT_STAT_SYSTEM] = "system", | |
10849 | }; | |
10850 | ||
10851 | static int cpuacct_stats_show(struct cgroup *cgrp, struct cftype *cft, | |
10852 | struct cgroup_map_cb *cb) | |
10853 | { | |
10854 | struct cpuacct *ca = cgroup_ca(cgrp); | |
10855 | int i; | |
10856 | ||
10857 | for (i = 0; i < CPUACCT_STAT_NSTATS; i++) { | |
10858 | s64 val = percpu_counter_read(&ca->cpustat[i]); | |
10859 | val = cputime64_to_clock_t(val); | |
10860 | cb->fill(cb, cpuacct_stat_desc[i], val); | |
10861 | } | |
10862 | return 0; | |
10863 | } | |
10864 | ||
d842de87 SV |
10865 | static struct cftype files[] = { |
10866 | { | |
10867 | .name = "usage", | |
f4c753b7 PM |
10868 | .read_u64 = cpuusage_read, |
10869 | .write_u64 = cpuusage_write, | |
d842de87 | 10870 | }, |
e9515c3c KC |
10871 | { |
10872 | .name = "usage_percpu", | |
10873 | .read_seq_string = cpuacct_percpu_seq_read, | |
10874 | }, | |
ef12fefa BR |
10875 | { |
10876 | .name = "stat", | |
10877 | .read_map = cpuacct_stats_show, | |
10878 | }, | |
d842de87 SV |
10879 | }; |
10880 | ||
32cd756a | 10881 | static int cpuacct_populate(struct cgroup_subsys *ss, struct cgroup *cgrp) |
d842de87 | 10882 | { |
32cd756a | 10883 | return cgroup_add_files(cgrp, ss, files, ARRAY_SIZE(files)); |
d842de87 SV |
10884 | } |
10885 | ||
10886 | /* | |
10887 | * charge this task's execution time to its accounting group. | |
10888 | * | |
10889 | * called with rq->lock held. | |
10890 | */ | |
10891 | static void cpuacct_charge(struct task_struct *tsk, u64 cputime) | |
10892 | { | |
10893 | struct cpuacct *ca; | |
934352f2 | 10894 | int cpu; |
d842de87 | 10895 | |
c40c6f85 | 10896 | if (unlikely(!cpuacct_subsys.active)) |
d842de87 SV |
10897 | return; |
10898 | ||
934352f2 | 10899 | cpu = task_cpu(tsk); |
a18b83b7 BR |
10900 | |
10901 | rcu_read_lock(); | |
10902 | ||
d842de87 | 10903 | ca = task_ca(tsk); |
d842de87 | 10904 | |
934352f2 | 10905 | for (; ca; ca = ca->parent) { |
b36128c8 | 10906 | u64 *cpuusage = per_cpu_ptr(ca->cpuusage, cpu); |
d842de87 SV |
10907 | *cpuusage += cputime; |
10908 | } | |
a18b83b7 BR |
10909 | |
10910 | rcu_read_unlock(); | |
d842de87 SV |
10911 | } |
10912 | ||
ef12fefa BR |
10913 | /* |
10914 | * Charge the system/user time to the task's accounting group. | |
10915 | */ | |
10916 | static void cpuacct_update_stats(struct task_struct *tsk, | |
10917 | enum cpuacct_stat_index idx, cputime_t val) | |
10918 | { | |
10919 | struct cpuacct *ca; | |
10920 | ||
10921 | if (unlikely(!cpuacct_subsys.active)) | |
10922 | return; | |
10923 | ||
10924 | rcu_read_lock(); | |
10925 | ca = task_ca(tsk); | |
10926 | ||
10927 | do { | |
10928 | percpu_counter_add(&ca->cpustat[idx], val); | |
10929 | ca = ca->parent; | |
10930 | } while (ca); | |
10931 | rcu_read_unlock(); | |
10932 | } | |
10933 | ||
d842de87 SV |
10934 | struct cgroup_subsys cpuacct_subsys = { |
10935 | .name = "cpuacct", | |
10936 | .create = cpuacct_create, | |
10937 | .destroy = cpuacct_destroy, | |
10938 | .populate = cpuacct_populate, | |
10939 | .subsys_id = cpuacct_subsys_id, | |
10940 | }; | |
10941 | #endif /* CONFIG_CGROUP_CPUACCT */ | |
03b042bf PM |
10942 | |
10943 | #ifndef CONFIG_SMP | |
10944 | ||
10945 | int rcu_expedited_torture_stats(char *page) | |
10946 | { | |
10947 | return 0; | |
10948 | } | |
10949 | EXPORT_SYMBOL_GPL(rcu_expedited_torture_stats); | |
10950 | ||
10951 | void synchronize_sched_expedited(void) | |
10952 | { | |
10953 | } | |
10954 | EXPORT_SYMBOL_GPL(synchronize_sched_expedited); | |
10955 | ||
10956 | #else /* #ifndef CONFIG_SMP */ | |
10957 | ||
10958 | static DEFINE_PER_CPU(struct migration_req, rcu_migration_req); | |
10959 | static DEFINE_MUTEX(rcu_sched_expedited_mutex); | |
10960 | ||
10961 | #define RCU_EXPEDITED_STATE_POST -2 | |
10962 | #define RCU_EXPEDITED_STATE_IDLE -1 | |
10963 | ||
10964 | static int rcu_expedited_state = RCU_EXPEDITED_STATE_IDLE; | |
10965 | ||
10966 | int rcu_expedited_torture_stats(char *page) | |
10967 | { | |
10968 | int cnt = 0; | |
10969 | int cpu; | |
10970 | ||
10971 | cnt += sprintf(&page[cnt], "state: %d /", rcu_expedited_state); | |
10972 | for_each_online_cpu(cpu) { | |
10973 | cnt += sprintf(&page[cnt], " %d:%d", | |
10974 | cpu, per_cpu(rcu_migration_req, cpu).dest_cpu); | |
10975 | } | |
10976 | cnt += sprintf(&page[cnt], "\n"); | |
10977 | return cnt; | |
10978 | } | |
10979 | EXPORT_SYMBOL_GPL(rcu_expedited_torture_stats); | |
10980 | ||
10981 | static long synchronize_sched_expedited_count; | |
10982 | ||
10983 | /* | |
10984 | * Wait for an rcu-sched grace period to elapse, but use "big hammer" | |
10985 | * approach to force grace period to end quickly. This consumes | |
10986 | * significant time on all CPUs, and is thus not recommended for | |
10987 | * any sort of common-case code. | |
10988 | * | |
10989 | * Note that it is illegal to call this function while holding any | |
10990 | * lock that is acquired by a CPU-hotplug notifier. Failing to | |
10991 | * observe this restriction will result in deadlock. | |
10992 | */ | |
10993 | void synchronize_sched_expedited(void) | |
10994 | { | |
10995 | int cpu; | |
10996 | unsigned long flags; | |
10997 | bool need_full_sync = 0; | |
10998 | struct rq *rq; | |
10999 | struct migration_req *req; | |
11000 | long snap; | |
11001 | int trycount = 0; | |
11002 | ||
11003 | smp_mb(); /* ensure prior mod happens before capturing snap. */ | |
11004 | snap = ACCESS_ONCE(synchronize_sched_expedited_count) + 1; | |
11005 | get_online_cpus(); | |
11006 | while (!mutex_trylock(&rcu_sched_expedited_mutex)) { | |
11007 | put_online_cpus(); | |
11008 | if (trycount++ < 10) | |
11009 | udelay(trycount * num_online_cpus()); | |
11010 | else { | |
11011 | synchronize_sched(); | |
11012 | return; | |
11013 | } | |
11014 | if (ACCESS_ONCE(synchronize_sched_expedited_count) - snap > 0) { | |
11015 | smp_mb(); /* ensure test happens before caller kfree */ | |
11016 | return; | |
11017 | } | |
11018 | get_online_cpus(); | |
11019 | } | |
11020 | rcu_expedited_state = RCU_EXPEDITED_STATE_POST; | |
11021 | for_each_online_cpu(cpu) { | |
11022 | rq = cpu_rq(cpu); | |
11023 | req = &per_cpu(rcu_migration_req, cpu); | |
11024 | init_completion(&req->done); | |
11025 | req->task = NULL; | |
11026 | req->dest_cpu = RCU_MIGRATION_NEED_QS; | |
05fa785c | 11027 | raw_spin_lock_irqsave(&rq->lock, flags); |
03b042bf | 11028 | list_add(&req->list, &rq->migration_queue); |
05fa785c | 11029 | raw_spin_unlock_irqrestore(&rq->lock, flags); |
03b042bf PM |
11030 | wake_up_process(rq->migration_thread); |
11031 | } | |
11032 | for_each_online_cpu(cpu) { | |
11033 | rcu_expedited_state = cpu; | |
11034 | req = &per_cpu(rcu_migration_req, cpu); | |
11035 | rq = cpu_rq(cpu); | |
11036 | wait_for_completion(&req->done); | |
05fa785c | 11037 | raw_spin_lock_irqsave(&rq->lock, flags); |
03b042bf PM |
11038 | if (unlikely(req->dest_cpu == RCU_MIGRATION_MUST_SYNC)) |
11039 | need_full_sync = 1; | |
11040 | req->dest_cpu = RCU_MIGRATION_IDLE; | |
05fa785c | 11041 | raw_spin_unlock_irqrestore(&rq->lock, flags); |
03b042bf PM |
11042 | } |
11043 | rcu_expedited_state = RCU_EXPEDITED_STATE_IDLE; | |
956539b7 | 11044 | synchronize_sched_expedited_count++; |
03b042bf PM |
11045 | mutex_unlock(&rcu_sched_expedited_mutex); |
11046 | put_online_cpus(); | |
11047 | if (need_full_sync) | |
11048 | synchronize_sched(); | |
11049 | } | |
11050 | EXPORT_SYMBOL_GPL(synchronize_sched_expedited); | |
11051 | ||
11052 | #endif /* #else #ifndef CONFIG_SMP */ |