]>
Commit | Line | Data |
---|---|---|
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> |
1da177e4 LT |
42 | #include <linux/security.h> |
43 | #include <linux/notifier.h> | |
44 | #include <linux/profile.h> | |
7dfb7103 | 45 | #include <linux/freezer.h> |
198e2f18 | 46 | #include <linux/vmalloc.h> |
1da177e4 LT |
47 | #include <linux/blkdev.h> |
48 | #include <linux/delay.h> | |
b488893a | 49 | #include <linux/pid_namespace.h> |
1da177e4 LT |
50 | #include <linux/smp.h> |
51 | #include <linux/threads.h> | |
52 | #include <linux/timer.h> | |
53 | #include <linux/rcupdate.h> | |
54 | #include <linux/cpu.h> | |
55 | #include <linux/cpuset.h> | |
56 | #include <linux/percpu.h> | |
57 | #include <linux/kthread.h> | |
b5aadf7f | 58 | #include <linux/proc_fs.h> |
1da177e4 | 59 | #include <linux/seq_file.h> |
e692ab53 | 60 | #include <linux/sysctl.h> |
1da177e4 LT |
61 | #include <linux/syscalls.h> |
62 | #include <linux/times.h> | |
8f0ab514 | 63 | #include <linux/tsacct_kern.h> |
c6fd91f0 | 64 | #include <linux/kprobes.h> |
0ff92245 | 65 | #include <linux/delayacct.h> |
5517d86b | 66 | #include <linux/reciprocal_div.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> |
434d53b0 | 71 | #include <linux/bootmem.h> |
f00b45c1 PZ |
72 | #include <linux/debugfs.h> |
73 | #include <linux/ctype.h> | |
6cd8a4bb | 74 | #include <linux/ftrace.h> |
0a16b607 | 75 | #include <trace/sched.h> |
1da177e4 | 76 | |
5517d86b | 77 | #include <asm/tlb.h> |
838225b4 | 78 | #include <asm/irq_regs.h> |
1da177e4 | 79 | |
6e0534f2 GH |
80 | #include "sched_cpupri.h" |
81 | ||
1da177e4 LT |
82 | /* |
83 | * Convert user-nice values [ -20 ... 0 ... 19 ] | |
84 | * to static priority [ MAX_RT_PRIO..MAX_PRIO-1 ], | |
85 | * and back. | |
86 | */ | |
87 | #define NICE_TO_PRIO(nice) (MAX_RT_PRIO + (nice) + 20) | |
88 | #define PRIO_TO_NICE(prio) ((prio) - MAX_RT_PRIO - 20) | |
89 | #define TASK_NICE(p) PRIO_TO_NICE((p)->static_prio) | |
90 | ||
91 | /* | |
92 | * 'User priority' is the nice value converted to something we | |
93 | * can work with better when scaling various scheduler parameters, | |
94 | * it's a [ 0 ... 39 ] range. | |
95 | */ | |
96 | #define USER_PRIO(p) ((p)-MAX_RT_PRIO) | |
97 | #define TASK_USER_PRIO(p) USER_PRIO((p)->static_prio) | |
98 | #define MAX_USER_PRIO (USER_PRIO(MAX_PRIO)) | |
99 | ||
100 | /* | |
d7876a08 | 101 | * Helpers for converting nanosecond timing to jiffy resolution |
1da177e4 | 102 | */ |
d6322faf | 103 | #define NS_TO_JIFFIES(TIME) ((unsigned long)(TIME) / (NSEC_PER_SEC / HZ)) |
1da177e4 | 104 | |
6aa645ea IM |
105 | #define NICE_0_LOAD SCHED_LOAD_SCALE |
106 | #define NICE_0_SHIFT SCHED_LOAD_SHIFT | |
107 | ||
1da177e4 LT |
108 | /* |
109 | * These are the 'tuning knobs' of the scheduler: | |
110 | * | |
a4ec24b4 | 111 | * default timeslice is 100 msecs (used only for SCHED_RR tasks). |
1da177e4 LT |
112 | * Timeslices get refilled after they expire. |
113 | */ | |
1da177e4 | 114 | #define DEF_TIMESLICE (100 * HZ / 1000) |
2dd73a4f | 115 | |
d0b27fa7 PZ |
116 | /* |
117 | * single value that denotes runtime == period, ie unlimited time. | |
118 | */ | |
119 | #define RUNTIME_INF ((u64)~0ULL) | |
120 | ||
7e066fb8 MD |
121 | DEFINE_TRACE(sched_wait_task); |
122 | DEFINE_TRACE(sched_wakeup); | |
123 | DEFINE_TRACE(sched_wakeup_new); | |
124 | DEFINE_TRACE(sched_switch); | |
125 | DEFINE_TRACE(sched_migrate_task); | |
126 | ||
5517d86b | 127 | #ifdef CONFIG_SMP |
fd2ab30b SN |
128 | |
129 | static void double_rq_lock(struct rq *rq1, struct rq *rq2); | |
130 | ||
5517d86b ED |
131 | /* |
132 | * Divide a load by a sched group cpu_power : (load / sg->__cpu_power) | |
133 | * Since cpu_power is a 'constant', we can use a reciprocal divide. | |
134 | */ | |
135 | static inline u32 sg_div_cpu_power(const struct sched_group *sg, u32 load) | |
136 | { | |
137 | return reciprocal_divide(load, sg->reciprocal_cpu_power); | |
138 | } | |
139 | ||
140 | /* | |
141 | * Each time a sched group cpu_power is changed, | |
142 | * we must compute its reciprocal value | |
143 | */ | |
144 | static inline void sg_inc_cpu_power(struct sched_group *sg, u32 val) | |
145 | { | |
146 | sg->__cpu_power += val; | |
147 | sg->reciprocal_cpu_power = reciprocal_value(sg->__cpu_power); | |
148 | } | |
149 | #endif | |
150 | ||
e05606d3 IM |
151 | static inline int rt_policy(int policy) |
152 | { | |
3f33a7ce | 153 | if (unlikely(policy == SCHED_FIFO || policy == SCHED_RR)) |
e05606d3 IM |
154 | return 1; |
155 | return 0; | |
156 | } | |
157 | ||
158 | static inline int task_has_rt_policy(struct task_struct *p) | |
159 | { | |
160 | return rt_policy(p->policy); | |
161 | } | |
162 | ||
1da177e4 | 163 | /* |
6aa645ea | 164 | * This is the priority-queue data structure of the RT scheduling class: |
1da177e4 | 165 | */ |
6aa645ea IM |
166 | struct rt_prio_array { |
167 | DECLARE_BITMAP(bitmap, MAX_RT_PRIO+1); /* include 1 bit for delimiter */ | |
168 | struct list_head queue[MAX_RT_PRIO]; | |
169 | }; | |
170 | ||
d0b27fa7 | 171 | struct rt_bandwidth { |
ea736ed5 IM |
172 | /* nests inside the rq lock: */ |
173 | spinlock_t rt_runtime_lock; | |
174 | ktime_t rt_period; | |
175 | u64 rt_runtime; | |
176 | struct hrtimer rt_period_timer; | |
d0b27fa7 PZ |
177 | }; |
178 | ||
179 | static struct rt_bandwidth def_rt_bandwidth; | |
180 | ||
181 | static int do_sched_rt_period_timer(struct rt_bandwidth *rt_b, int overrun); | |
182 | ||
183 | static enum hrtimer_restart sched_rt_period_timer(struct hrtimer *timer) | |
184 | { | |
185 | struct rt_bandwidth *rt_b = | |
186 | container_of(timer, struct rt_bandwidth, rt_period_timer); | |
187 | ktime_t now; | |
188 | int overrun; | |
189 | int idle = 0; | |
190 | ||
191 | for (;;) { | |
192 | now = hrtimer_cb_get_time(timer); | |
193 | overrun = hrtimer_forward(timer, now, rt_b->rt_period); | |
194 | ||
195 | if (!overrun) | |
196 | break; | |
197 | ||
198 | idle = do_sched_rt_period_timer(rt_b, overrun); | |
199 | } | |
200 | ||
201 | return idle ? HRTIMER_NORESTART : HRTIMER_RESTART; | |
202 | } | |
203 | ||
204 | static | |
205 | void init_rt_bandwidth(struct rt_bandwidth *rt_b, u64 period, u64 runtime) | |
206 | { | |
207 | rt_b->rt_period = ns_to_ktime(period); | |
208 | rt_b->rt_runtime = runtime; | |
209 | ||
ac086bc2 PZ |
210 | spin_lock_init(&rt_b->rt_runtime_lock); |
211 | ||
d0b27fa7 PZ |
212 | hrtimer_init(&rt_b->rt_period_timer, |
213 | CLOCK_MONOTONIC, HRTIMER_MODE_REL); | |
214 | rt_b->rt_period_timer.function = sched_rt_period_timer; | |
d0b27fa7 PZ |
215 | } |
216 | ||
c8bfff6d KH |
217 | static inline int rt_bandwidth_enabled(void) |
218 | { | |
219 | return sysctl_sched_rt_runtime >= 0; | |
d0b27fa7 PZ |
220 | } |
221 | ||
222 | static void start_rt_bandwidth(struct rt_bandwidth *rt_b) | |
223 | { | |
224 | ktime_t now; | |
225 | ||
0b148fa0 | 226 | if (rt_bandwidth_enabled() && rt_b->rt_runtime == RUNTIME_INF) |
d0b27fa7 PZ |
227 | return; |
228 | ||
229 | if (hrtimer_active(&rt_b->rt_period_timer)) | |
230 | return; | |
231 | ||
232 | spin_lock(&rt_b->rt_runtime_lock); | |
233 | for (;;) { | |
234 | if (hrtimer_active(&rt_b->rt_period_timer)) | |
235 | break; | |
236 | ||
237 | now = hrtimer_cb_get_time(&rt_b->rt_period_timer); | |
238 | hrtimer_forward(&rt_b->rt_period_timer, now, rt_b->rt_period); | |
cc584b21 AV |
239 | hrtimer_start_expires(&rt_b->rt_period_timer, |
240 | HRTIMER_MODE_ABS); | |
d0b27fa7 PZ |
241 | } |
242 | spin_unlock(&rt_b->rt_runtime_lock); | |
243 | } | |
244 | ||
245 | #ifdef CONFIG_RT_GROUP_SCHED | |
246 | static void destroy_rt_bandwidth(struct rt_bandwidth *rt_b) | |
247 | { | |
248 | hrtimer_cancel(&rt_b->rt_period_timer); | |
249 | } | |
250 | #endif | |
251 | ||
712555ee HC |
252 | /* |
253 | * sched_domains_mutex serializes calls to arch_init_sched_domains, | |
254 | * detach_destroy_domains and partition_sched_domains. | |
255 | */ | |
256 | static DEFINE_MUTEX(sched_domains_mutex); | |
257 | ||
052f1dc7 | 258 | #ifdef CONFIG_GROUP_SCHED |
29f59db3 | 259 | |
68318b8e SV |
260 | #include <linux/cgroup.h> |
261 | ||
29f59db3 SV |
262 | struct cfs_rq; |
263 | ||
6f505b16 PZ |
264 | static LIST_HEAD(task_groups); |
265 | ||
29f59db3 | 266 | /* task group related information */ |
4cf86d77 | 267 | struct task_group { |
052f1dc7 | 268 | #ifdef CONFIG_CGROUP_SCHED |
68318b8e SV |
269 | struct cgroup_subsys_state css; |
270 | #endif | |
052f1dc7 | 271 | |
6c415b92 AB |
272 | #ifdef CONFIG_USER_SCHED |
273 | uid_t uid; | |
274 | #endif | |
275 | ||
052f1dc7 | 276 | #ifdef CONFIG_FAIR_GROUP_SCHED |
29f59db3 SV |
277 | /* schedulable entities of this group on each cpu */ |
278 | struct sched_entity **se; | |
279 | /* runqueue "owned" by this group on each cpu */ | |
280 | struct cfs_rq **cfs_rq; | |
281 | unsigned long shares; | |
052f1dc7 PZ |
282 | #endif |
283 | ||
284 | #ifdef CONFIG_RT_GROUP_SCHED | |
285 | struct sched_rt_entity **rt_se; | |
286 | struct rt_rq **rt_rq; | |
287 | ||
d0b27fa7 | 288 | struct rt_bandwidth rt_bandwidth; |
052f1dc7 | 289 | #endif |
6b2d7700 | 290 | |
ae8393e5 | 291 | struct rcu_head rcu; |
6f505b16 | 292 | struct list_head list; |
f473aa5e PZ |
293 | |
294 | struct task_group *parent; | |
295 | struct list_head siblings; | |
296 | struct list_head children; | |
29f59db3 SV |
297 | }; |
298 | ||
354d60c2 | 299 | #ifdef CONFIG_USER_SCHED |
eff766a6 | 300 | |
6c415b92 AB |
301 | /* Helper function to pass uid information to create_sched_user() */ |
302 | void set_tg_uid(struct user_struct *user) | |
303 | { | |
304 | user->tg->uid = user->uid; | |
305 | } | |
306 | ||
eff766a6 PZ |
307 | /* |
308 | * Root task group. | |
309 | * Every UID task group (including init_task_group aka UID-0) will | |
310 | * be a child to this group. | |
311 | */ | |
312 | struct task_group root_task_group; | |
313 | ||
052f1dc7 | 314 | #ifdef CONFIG_FAIR_GROUP_SCHED |
29f59db3 SV |
315 | /* Default task group's sched entity on each cpu */ |
316 | static DEFINE_PER_CPU(struct sched_entity, init_sched_entity); | |
317 | /* Default task group's cfs_rq on each cpu */ | |
318 | static DEFINE_PER_CPU(struct cfs_rq, init_cfs_rq) ____cacheline_aligned_in_smp; | |
6d6bc0ad | 319 | #endif /* CONFIG_FAIR_GROUP_SCHED */ |
052f1dc7 PZ |
320 | |
321 | #ifdef CONFIG_RT_GROUP_SCHED | |
322 | static DEFINE_PER_CPU(struct sched_rt_entity, init_sched_rt_entity); | |
323 | static DEFINE_PER_CPU(struct rt_rq, init_rt_rq) ____cacheline_aligned_in_smp; | |
6d6bc0ad | 324 | #endif /* CONFIG_RT_GROUP_SCHED */ |
9a7e0b18 | 325 | #else /* !CONFIG_USER_SCHED */ |
eff766a6 | 326 | #define root_task_group init_task_group |
9a7e0b18 | 327 | #endif /* CONFIG_USER_SCHED */ |
6f505b16 | 328 | |
8ed36996 | 329 | /* task_group_lock serializes add/remove of task groups and also changes to |
ec2c507f SV |
330 | * a task group's cpu shares. |
331 | */ | |
8ed36996 | 332 | static DEFINE_SPINLOCK(task_group_lock); |
ec2c507f | 333 | |
052f1dc7 | 334 | #ifdef CONFIG_FAIR_GROUP_SCHED |
052f1dc7 PZ |
335 | #ifdef CONFIG_USER_SCHED |
336 | # define INIT_TASK_GROUP_LOAD (2*NICE_0_LOAD) | |
6d6bc0ad | 337 | #else /* !CONFIG_USER_SCHED */ |
052f1dc7 | 338 | # define INIT_TASK_GROUP_LOAD NICE_0_LOAD |
6d6bc0ad | 339 | #endif /* CONFIG_USER_SCHED */ |
052f1dc7 | 340 | |
cb4ad1ff | 341 | /* |
2e084786 LJ |
342 | * A weight of 0 or 1 can cause arithmetics problems. |
343 | * A weight of a cfs_rq is the sum of weights of which entities | |
344 | * are queued on this cfs_rq, so a weight of a entity should not be | |
345 | * too large, so as the shares value of a task group. | |
cb4ad1ff MX |
346 | * (The default weight is 1024 - so there's no practical |
347 | * limitation from this.) | |
348 | */ | |
18d95a28 | 349 | #define MIN_SHARES 2 |
2e084786 | 350 | #define MAX_SHARES (1UL << 18) |
18d95a28 | 351 | |
052f1dc7 PZ |
352 | static int init_task_group_load = INIT_TASK_GROUP_LOAD; |
353 | #endif | |
354 | ||
29f59db3 | 355 | /* Default task group. |
3a252015 | 356 | * Every task in system belong to this group at bootup. |
29f59db3 | 357 | */ |
434d53b0 | 358 | struct task_group init_task_group; |
29f59db3 SV |
359 | |
360 | /* return group to which a task belongs */ | |
4cf86d77 | 361 | static inline struct task_group *task_group(struct task_struct *p) |
29f59db3 | 362 | { |
4cf86d77 | 363 | struct task_group *tg; |
9b5b7751 | 364 | |
052f1dc7 | 365 | #ifdef CONFIG_USER_SCHED |
c69e8d9c DH |
366 | rcu_read_lock(); |
367 | tg = __task_cred(p)->user->tg; | |
368 | rcu_read_unlock(); | |
052f1dc7 | 369 | #elif defined(CONFIG_CGROUP_SCHED) |
68318b8e SV |
370 | tg = container_of(task_subsys_state(p, cpu_cgroup_subsys_id), |
371 | struct task_group, css); | |
24e377a8 | 372 | #else |
41a2d6cf | 373 | tg = &init_task_group; |
24e377a8 | 374 | #endif |
9b5b7751 | 375 | return tg; |
29f59db3 SV |
376 | } |
377 | ||
378 | /* Change a task's cfs_rq and parent entity if it moves across CPUs/groups */ | |
6f505b16 | 379 | static inline void set_task_rq(struct task_struct *p, unsigned int cpu) |
29f59db3 | 380 | { |
052f1dc7 | 381 | #ifdef CONFIG_FAIR_GROUP_SCHED |
ce96b5ac DA |
382 | p->se.cfs_rq = task_group(p)->cfs_rq[cpu]; |
383 | p->se.parent = task_group(p)->se[cpu]; | |
052f1dc7 | 384 | #endif |
6f505b16 | 385 | |
052f1dc7 | 386 | #ifdef CONFIG_RT_GROUP_SCHED |
6f505b16 PZ |
387 | p->rt.rt_rq = task_group(p)->rt_rq[cpu]; |
388 | p->rt.parent = task_group(p)->rt_se[cpu]; | |
052f1dc7 | 389 | #endif |
29f59db3 SV |
390 | } |
391 | ||
392 | #else | |
393 | ||
6f505b16 | 394 | static inline void set_task_rq(struct task_struct *p, unsigned int cpu) { } |
83378269 PZ |
395 | static inline struct task_group *task_group(struct task_struct *p) |
396 | { | |
397 | return NULL; | |
398 | } | |
29f59db3 | 399 | |
052f1dc7 | 400 | #endif /* CONFIG_GROUP_SCHED */ |
29f59db3 | 401 | |
6aa645ea IM |
402 | /* CFS-related fields in a runqueue */ |
403 | struct cfs_rq { | |
404 | struct load_weight load; | |
405 | unsigned long nr_running; | |
406 | ||
6aa645ea | 407 | u64 exec_clock; |
e9acbff6 | 408 | u64 min_vruntime; |
6aa645ea IM |
409 | |
410 | struct rb_root tasks_timeline; | |
411 | struct rb_node *rb_leftmost; | |
4a55bd5e PZ |
412 | |
413 | struct list_head tasks; | |
414 | struct list_head *balance_iterator; | |
415 | ||
416 | /* | |
417 | * 'curr' points to currently running entity on this cfs_rq. | |
6aa645ea IM |
418 | * It is set to NULL otherwise (i.e when none are currently running). |
419 | */ | |
4793241b | 420 | struct sched_entity *curr, *next, *last; |
ddc97297 | 421 | |
5ac5c4d6 | 422 | unsigned int nr_spread_over; |
ddc97297 | 423 | |
62160e3f | 424 | #ifdef CONFIG_FAIR_GROUP_SCHED |
6aa645ea IM |
425 | struct rq *rq; /* cpu runqueue to which this cfs_rq is attached */ |
426 | ||
41a2d6cf IM |
427 | /* |
428 | * leaf cfs_rqs are those that hold tasks (lowest schedulable entity in | |
6aa645ea IM |
429 | * a hierarchy). Non-leaf lrqs hold other higher schedulable entities |
430 | * (like users, containers etc.) | |
431 | * | |
432 | * leaf_cfs_rq_list ties together list of leaf cfs_rq's in a cpu. This | |
433 | * list is used during load balance. | |
434 | */ | |
41a2d6cf IM |
435 | struct list_head leaf_cfs_rq_list; |
436 | struct task_group *tg; /* group that "owns" this runqueue */ | |
c09595f6 PZ |
437 | |
438 | #ifdef CONFIG_SMP | |
c09595f6 | 439 | /* |
c8cba857 | 440 | * the part of load.weight contributed by tasks |
c09595f6 | 441 | */ |
c8cba857 | 442 | unsigned long task_weight; |
c09595f6 | 443 | |
c8cba857 PZ |
444 | /* |
445 | * h_load = weight * f(tg) | |
446 | * | |
447 | * Where f(tg) is the recursive weight fraction assigned to | |
448 | * this group. | |
449 | */ | |
450 | unsigned long h_load; | |
c09595f6 | 451 | |
c8cba857 PZ |
452 | /* |
453 | * this cpu's part of tg->shares | |
454 | */ | |
455 | unsigned long shares; | |
f1d239f7 PZ |
456 | |
457 | /* | |
458 | * load.weight at the time we set shares | |
459 | */ | |
460 | unsigned long rq_weight; | |
c09595f6 | 461 | #endif |
6aa645ea IM |
462 | #endif |
463 | }; | |
1da177e4 | 464 | |
6aa645ea IM |
465 | /* Real-Time classes' related field in a runqueue: */ |
466 | struct rt_rq { | |
467 | struct rt_prio_array active; | |
63489e45 | 468 | unsigned long rt_nr_running; |
052f1dc7 | 469 | #if defined CONFIG_SMP || defined CONFIG_RT_GROUP_SCHED |
6f505b16 PZ |
470 | int highest_prio; /* highest queued rt task prio */ |
471 | #endif | |
fa85ae24 | 472 | #ifdef CONFIG_SMP |
73fe6aae | 473 | unsigned long rt_nr_migratory; |
a22d7fc1 | 474 | int overloaded; |
fa85ae24 | 475 | #endif |
6f505b16 | 476 | int rt_throttled; |
fa85ae24 | 477 | u64 rt_time; |
ac086bc2 | 478 | u64 rt_runtime; |
ea736ed5 | 479 | /* Nests inside the rq lock: */ |
ac086bc2 | 480 | spinlock_t rt_runtime_lock; |
6f505b16 | 481 | |
052f1dc7 | 482 | #ifdef CONFIG_RT_GROUP_SCHED |
23b0fdfc PZ |
483 | unsigned long rt_nr_boosted; |
484 | ||
6f505b16 PZ |
485 | struct rq *rq; |
486 | struct list_head leaf_rt_rq_list; | |
487 | struct task_group *tg; | |
488 | struct sched_rt_entity *rt_se; | |
489 | #endif | |
6aa645ea IM |
490 | }; |
491 | ||
57d885fe GH |
492 | #ifdef CONFIG_SMP |
493 | ||
494 | /* | |
495 | * We add the notion of a root-domain which will be used to define per-domain | |
0eab9146 IM |
496 | * variables. Each exclusive cpuset essentially defines an island domain by |
497 | * fully partitioning the member cpus from any other cpuset. Whenever a new | |
57d885fe GH |
498 | * exclusive cpuset is created, we also create and attach a new root-domain |
499 | * object. | |
500 | * | |
57d885fe GH |
501 | */ |
502 | struct root_domain { | |
503 | atomic_t refcount; | |
c6c4927b RR |
504 | cpumask_var_t span; |
505 | cpumask_var_t online; | |
637f5085 | 506 | |
0eab9146 | 507 | /* |
637f5085 GH |
508 | * The "RT overload" flag: it gets set if a CPU has more than |
509 | * one runnable RT task. | |
510 | */ | |
c6c4927b | 511 | cpumask_var_t rto_mask; |
0eab9146 | 512 | atomic_t rto_count; |
6e0534f2 GH |
513 | #ifdef CONFIG_SMP |
514 | struct cpupri cpupri; | |
515 | #endif | |
7a09b1a2 VS |
516 | #if defined(CONFIG_SCHED_MC) || defined(CONFIG_SCHED_SMT) |
517 | /* | |
518 | * Preferred wake up cpu nominated by sched_mc balance that will be | |
519 | * used when most cpus are idle in the system indicating overall very | |
520 | * low system utilisation. Triggered at POWERSAVINGS_BALANCE_WAKEUP(2) | |
521 | */ | |
522 | unsigned int sched_mc_preferred_wakeup_cpu; | |
523 | #endif | |
57d885fe GH |
524 | }; |
525 | ||
dc938520 GH |
526 | /* |
527 | * By default the system creates a single root-domain with all cpus as | |
528 | * members (mimicking the global state we have today). | |
529 | */ | |
57d885fe GH |
530 | static struct root_domain def_root_domain; |
531 | ||
532 | #endif | |
533 | ||
1da177e4 LT |
534 | /* |
535 | * This is the main, per-CPU runqueue data structure. | |
536 | * | |
537 | * Locking rule: those places that want to lock multiple runqueues | |
538 | * (such as the load balancing or the thread migration code), lock | |
539 | * acquire operations must be ordered by ascending &runqueue. | |
540 | */ | |
70b97a7f | 541 | struct rq { |
d8016491 IM |
542 | /* runqueue lock: */ |
543 | spinlock_t lock; | |
1da177e4 LT |
544 | |
545 | /* | |
546 | * nr_running and cpu_load should be in the same cacheline because | |
547 | * remote CPUs use both these fields when doing load calculation. | |
548 | */ | |
549 | unsigned long nr_running; | |
6aa645ea IM |
550 | #define CPU_LOAD_IDX_MAX 5 |
551 | unsigned long cpu_load[CPU_LOAD_IDX_MAX]; | |
bdecea3a | 552 | unsigned char idle_at_tick; |
46cb4b7c | 553 | #ifdef CONFIG_NO_HZ |
15934a37 | 554 | unsigned long last_tick_seen; |
46cb4b7c SS |
555 | unsigned char in_nohz_recently; |
556 | #endif | |
d8016491 IM |
557 | /* capture load from *all* tasks on this cpu: */ |
558 | struct load_weight load; | |
6aa645ea IM |
559 | unsigned long nr_load_updates; |
560 | u64 nr_switches; | |
561 | ||
562 | struct cfs_rq cfs; | |
6f505b16 | 563 | struct rt_rq rt; |
6f505b16 | 564 | |
6aa645ea | 565 | #ifdef CONFIG_FAIR_GROUP_SCHED |
d8016491 IM |
566 | /* list of leaf cfs_rq on this cpu: */ |
567 | struct list_head leaf_cfs_rq_list; | |
052f1dc7 PZ |
568 | #endif |
569 | #ifdef CONFIG_RT_GROUP_SCHED | |
6f505b16 | 570 | struct list_head leaf_rt_rq_list; |
1da177e4 | 571 | #endif |
1da177e4 LT |
572 | |
573 | /* | |
574 | * This is part of a global counter where only the total sum | |
575 | * over all CPUs matters. A task can increase this counter on | |
576 | * one CPU and if it got migrated afterwards it may decrease | |
577 | * it on another CPU. Always updated under the runqueue lock: | |
578 | */ | |
579 | unsigned long nr_uninterruptible; | |
580 | ||
36c8b586 | 581 | struct task_struct *curr, *idle; |
c9819f45 | 582 | unsigned long next_balance; |
1da177e4 | 583 | struct mm_struct *prev_mm; |
6aa645ea | 584 | |
3e51f33f | 585 | u64 clock; |
6aa645ea | 586 | |
1da177e4 LT |
587 | atomic_t nr_iowait; |
588 | ||
589 | #ifdef CONFIG_SMP | |
0eab9146 | 590 | struct root_domain *rd; |
1da177e4 LT |
591 | struct sched_domain *sd; |
592 | ||
593 | /* For active balancing */ | |
594 | int active_balance; | |
595 | int push_cpu; | |
d8016491 IM |
596 | /* cpu of this runqueue: */ |
597 | int cpu; | |
1f11eb6a | 598 | int online; |
1da177e4 | 599 | |
a8a51d5e | 600 | unsigned long avg_load_per_task; |
1da177e4 | 601 | |
36c8b586 | 602 | struct task_struct *migration_thread; |
1da177e4 LT |
603 | struct list_head migration_queue; |
604 | #endif | |
605 | ||
8f4d37ec | 606 | #ifdef CONFIG_SCHED_HRTICK |
31656519 PZ |
607 | #ifdef CONFIG_SMP |
608 | int hrtick_csd_pending; | |
609 | struct call_single_data hrtick_csd; | |
610 | #endif | |
8f4d37ec PZ |
611 | struct hrtimer hrtick_timer; |
612 | #endif | |
613 | ||
1da177e4 LT |
614 | #ifdef CONFIG_SCHEDSTATS |
615 | /* latency stats */ | |
616 | struct sched_info rq_sched_info; | |
9c2c4802 KC |
617 | unsigned long long rq_cpu_time; |
618 | /* could above be rq->cfs_rq.exec_clock + rq->rt_rq.rt_runtime ? */ | |
1da177e4 LT |
619 | |
620 | /* sys_sched_yield() stats */ | |
480b9434 KC |
621 | unsigned int yld_exp_empty; |
622 | unsigned int yld_act_empty; | |
623 | unsigned int yld_both_empty; | |
624 | unsigned int yld_count; | |
1da177e4 LT |
625 | |
626 | /* schedule() stats */ | |
480b9434 KC |
627 | unsigned int sched_switch; |
628 | unsigned int sched_count; | |
629 | unsigned int sched_goidle; | |
1da177e4 LT |
630 | |
631 | /* try_to_wake_up() stats */ | |
480b9434 KC |
632 | unsigned int ttwu_count; |
633 | unsigned int ttwu_local; | |
b8efb561 IM |
634 | |
635 | /* BKL stats */ | |
480b9434 | 636 | unsigned int bkl_count; |
1da177e4 LT |
637 | #endif |
638 | }; | |
639 | ||
f34e3b61 | 640 | static DEFINE_PER_CPU_SHARED_ALIGNED(struct rq, runqueues); |
1da177e4 | 641 | |
15afe09b | 642 | static inline void check_preempt_curr(struct rq *rq, struct task_struct *p, int sync) |
dd41f596 | 643 | { |
15afe09b | 644 | rq->curr->sched_class->check_preempt_curr(rq, p, sync); |
dd41f596 IM |
645 | } |
646 | ||
0a2966b4 CL |
647 | static inline int cpu_of(struct rq *rq) |
648 | { | |
649 | #ifdef CONFIG_SMP | |
650 | return rq->cpu; | |
651 | #else | |
652 | return 0; | |
653 | #endif | |
654 | } | |
655 | ||
674311d5 NP |
656 | /* |
657 | * The domain tree (rq->sd) is protected by RCU's quiescent state transition. | |
1a20ff27 | 658 | * See detach_destroy_domains: synchronize_sched for details. |
674311d5 NP |
659 | * |
660 | * The domain tree of any CPU may only be accessed from within | |
661 | * preempt-disabled sections. | |
662 | */ | |
48f24c4d IM |
663 | #define for_each_domain(cpu, __sd) \ |
664 | for (__sd = rcu_dereference(cpu_rq(cpu)->sd); __sd; __sd = __sd->parent) | |
1da177e4 LT |
665 | |
666 | #define cpu_rq(cpu) (&per_cpu(runqueues, (cpu))) | |
667 | #define this_rq() (&__get_cpu_var(runqueues)) | |
668 | #define task_rq(p) cpu_rq(task_cpu(p)) | |
669 | #define cpu_curr(cpu) (cpu_rq(cpu)->curr) | |
670 | ||
3e51f33f PZ |
671 | static inline void update_rq_clock(struct rq *rq) |
672 | { | |
673 | rq->clock = sched_clock_cpu(cpu_of(rq)); | |
674 | } | |
675 | ||
bf5c91ba IM |
676 | /* |
677 | * Tunables that become constants when CONFIG_SCHED_DEBUG is off: | |
678 | */ | |
679 | #ifdef CONFIG_SCHED_DEBUG | |
680 | # define const_debug __read_mostly | |
681 | #else | |
682 | # define const_debug static const | |
683 | #endif | |
684 | ||
017730c1 IM |
685 | /** |
686 | * runqueue_is_locked | |
687 | * | |
688 | * Returns true if the current cpu runqueue is locked. | |
689 | * This interface allows printk to be called with the runqueue lock | |
690 | * held and know whether or not it is OK to wake up the klogd. | |
691 | */ | |
692 | int runqueue_is_locked(void) | |
693 | { | |
694 | int cpu = get_cpu(); | |
695 | struct rq *rq = cpu_rq(cpu); | |
696 | int ret; | |
697 | ||
698 | ret = spin_is_locked(&rq->lock); | |
699 | put_cpu(); | |
700 | return ret; | |
701 | } | |
702 | ||
bf5c91ba IM |
703 | /* |
704 | * Debugging: various feature bits | |
705 | */ | |
f00b45c1 PZ |
706 | |
707 | #define SCHED_FEAT(name, enabled) \ | |
708 | __SCHED_FEAT_##name , | |
709 | ||
bf5c91ba | 710 | enum { |
f00b45c1 | 711 | #include "sched_features.h" |
bf5c91ba IM |
712 | }; |
713 | ||
f00b45c1 PZ |
714 | #undef SCHED_FEAT |
715 | ||
716 | #define SCHED_FEAT(name, enabled) \ | |
717 | (1UL << __SCHED_FEAT_##name) * enabled | | |
718 | ||
bf5c91ba | 719 | const_debug unsigned int sysctl_sched_features = |
f00b45c1 PZ |
720 | #include "sched_features.h" |
721 | 0; | |
722 | ||
723 | #undef SCHED_FEAT | |
724 | ||
725 | #ifdef CONFIG_SCHED_DEBUG | |
726 | #define SCHED_FEAT(name, enabled) \ | |
727 | #name , | |
728 | ||
983ed7a6 | 729 | static __read_mostly char *sched_feat_names[] = { |
f00b45c1 PZ |
730 | #include "sched_features.h" |
731 | NULL | |
732 | }; | |
733 | ||
734 | #undef SCHED_FEAT | |
735 | ||
34f3a814 | 736 | static int sched_feat_show(struct seq_file *m, void *v) |
f00b45c1 | 737 | { |
f00b45c1 PZ |
738 | int i; |
739 | ||
740 | for (i = 0; sched_feat_names[i]; i++) { | |
34f3a814 LZ |
741 | if (!(sysctl_sched_features & (1UL << i))) |
742 | seq_puts(m, "NO_"); | |
743 | seq_printf(m, "%s ", sched_feat_names[i]); | |
f00b45c1 | 744 | } |
34f3a814 | 745 | seq_puts(m, "\n"); |
f00b45c1 | 746 | |
34f3a814 | 747 | return 0; |
f00b45c1 PZ |
748 | } |
749 | ||
750 | static ssize_t | |
751 | sched_feat_write(struct file *filp, const char __user *ubuf, | |
752 | size_t cnt, loff_t *ppos) | |
753 | { | |
754 | char buf[64]; | |
755 | char *cmp = buf; | |
756 | int neg = 0; | |
757 | int i; | |
758 | ||
759 | if (cnt > 63) | |
760 | cnt = 63; | |
761 | ||
762 | if (copy_from_user(&buf, ubuf, cnt)) | |
763 | return -EFAULT; | |
764 | ||
765 | buf[cnt] = 0; | |
766 | ||
c24b7c52 | 767 | if (strncmp(buf, "NO_", 3) == 0) { |
f00b45c1 PZ |
768 | neg = 1; |
769 | cmp += 3; | |
770 | } | |
771 | ||
772 | for (i = 0; sched_feat_names[i]; i++) { | |
773 | int len = strlen(sched_feat_names[i]); | |
774 | ||
775 | if (strncmp(cmp, sched_feat_names[i], len) == 0) { | |
776 | if (neg) | |
777 | sysctl_sched_features &= ~(1UL << i); | |
778 | else | |
779 | sysctl_sched_features |= (1UL << i); | |
780 | break; | |
781 | } | |
782 | } | |
783 | ||
784 | if (!sched_feat_names[i]) | |
785 | return -EINVAL; | |
786 | ||
787 | filp->f_pos += cnt; | |
788 | ||
789 | return cnt; | |
790 | } | |
791 | ||
34f3a814 LZ |
792 | static int sched_feat_open(struct inode *inode, struct file *filp) |
793 | { | |
794 | return single_open(filp, sched_feat_show, NULL); | |
795 | } | |
796 | ||
f00b45c1 | 797 | static struct file_operations sched_feat_fops = { |
34f3a814 LZ |
798 | .open = sched_feat_open, |
799 | .write = sched_feat_write, | |
800 | .read = seq_read, | |
801 | .llseek = seq_lseek, | |
802 | .release = single_release, | |
f00b45c1 PZ |
803 | }; |
804 | ||
805 | static __init int sched_init_debug(void) | |
806 | { | |
f00b45c1 PZ |
807 | debugfs_create_file("sched_features", 0644, NULL, NULL, |
808 | &sched_feat_fops); | |
809 | ||
810 | return 0; | |
811 | } | |
812 | late_initcall(sched_init_debug); | |
813 | ||
814 | #endif | |
815 | ||
816 | #define sched_feat(x) (sysctl_sched_features & (1UL << __SCHED_FEAT_##x)) | |
bf5c91ba | 817 | |
b82d9fdd PZ |
818 | /* |
819 | * Number of tasks to iterate in a single balance run. | |
820 | * Limited because this is done with IRQs disabled. | |
821 | */ | |
822 | const_debug unsigned int sysctl_sched_nr_migrate = 32; | |
823 | ||
2398f2c6 PZ |
824 | /* |
825 | * ratelimit for updating the group shares. | |
55cd5340 | 826 | * default: 0.25ms |
2398f2c6 | 827 | */ |
55cd5340 | 828 | unsigned int sysctl_sched_shares_ratelimit = 250000; |
2398f2c6 | 829 | |
ffda12a1 PZ |
830 | /* |
831 | * Inject some fuzzyness into changing the per-cpu group shares | |
832 | * this avoids remote rq-locks at the expense of fairness. | |
833 | * default: 4 | |
834 | */ | |
835 | unsigned int sysctl_sched_shares_thresh = 4; | |
836 | ||
fa85ae24 | 837 | /* |
9f0c1e56 | 838 | * period over which we measure -rt task cpu usage in us. |
fa85ae24 PZ |
839 | * default: 1s |
840 | */ | |
9f0c1e56 | 841 | unsigned int sysctl_sched_rt_period = 1000000; |
fa85ae24 | 842 | |
6892b75e IM |
843 | static __read_mostly int scheduler_running; |
844 | ||
9f0c1e56 PZ |
845 | /* |
846 | * part of the period that we allow rt tasks to run in us. | |
847 | * default: 0.95s | |
848 | */ | |
849 | int sysctl_sched_rt_runtime = 950000; | |
fa85ae24 | 850 | |
d0b27fa7 PZ |
851 | static inline u64 global_rt_period(void) |
852 | { | |
853 | return (u64)sysctl_sched_rt_period * NSEC_PER_USEC; | |
854 | } | |
855 | ||
856 | static inline u64 global_rt_runtime(void) | |
857 | { | |
e26873bb | 858 | if (sysctl_sched_rt_runtime < 0) |
d0b27fa7 PZ |
859 | return RUNTIME_INF; |
860 | ||
861 | return (u64)sysctl_sched_rt_runtime * NSEC_PER_USEC; | |
862 | } | |
fa85ae24 | 863 | |
1da177e4 | 864 | #ifndef prepare_arch_switch |
4866cde0 NP |
865 | # define prepare_arch_switch(next) do { } while (0) |
866 | #endif | |
867 | #ifndef finish_arch_switch | |
868 | # define finish_arch_switch(prev) do { } while (0) | |
869 | #endif | |
870 | ||
051a1d1a DA |
871 | static inline int task_current(struct rq *rq, struct task_struct *p) |
872 | { | |
873 | return rq->curr == p; | |
874 | } | |
875 | ||
4866cde0 | 876 | #ifndef __ARCH_WANT_UNLOCKED_CTXSW |
70b97a7f | 877 | static inline int task_running(struct rq *rq, struct task_struct *p) |
4866cde0 | 878 | { |
051a1d1a | 879 | return task_current(rq, p); |
4866cde0 NP |
880 | } |
881 | ||
70b97a7f | 882 | static inline void prepare_lock_switch(struct rq *rq, struct task_struct *next) |
4866cde0 NP |
883 | { |
884 | } | |
885 | ||
70b97a7f | 886 | static inline void finish_lock_switch(struct rq *rq, struct task_struct *prev) |
4866cde0 | 887 | { |
da04c035 IM |
888 | #ifdef CONFIG_DEBUG_SPINLOCK |
889 | /* this is a valid case when another task releases the spinlock */ | |
890 | rq->lock.owner = current; | |
891 | #endif | |
8a25d5de IM |
892 | /* |
893 | * If we are tracking spinlock dependencies then we have to | |
894 | * fix up the runqueue lock - which gets 'carried over' from | |
895 | * prev into current: | |
896 | */ | |
897 | spin_acquire(&rq->lock.dep_map, 0, 0, _THIS_IP_); | |
898 | ||
4866cde0 NP |
899 | spin_unlock_irq(&rq->lock); |
900 | } | |
901 | ||
902 | #else /* __ARCH_WANT_UNLOCKED_CTXSW */ | |
70b97a7f | 903 | static inline int task_running(struct rq *rq, struct task_struct *p) |
4866cde0 NP |
904 | { |
905 | #ifdef CONFIG_SMP | |
906 | return p->oncpu; | |
907 | #else | |
051a1d1a | 908 | return task_current(rq, p); |
4866cde0 NP |
909 | #endif |
910 | } | |
911 | ||
70b97a7f | 912 | static inline void prepare_lock_switch(struct rq *rq, struct task_struct *next) |
4866cde0 NP |
913 | { |
914 | #ifdef CONFIG_SMP | |
915 | /* | |
916 | * We can optimise this out completely for !SMP, because the | |
917 | * SMP rebalancing from interrupt is the only thing that cares | |
918 | * here. | |
919 | */ | |
920 | next->oncpu = 1; | |
921 | #endif | |
922 | #ifdef __ARCH_WANT_INTERRUPTS_ON_CTXSW | |
923 | spin_unlock_irq(&rq->lock); | |
924 | #else | |
925 | spin_unlock(&rq->lock); | |
926 | #endif | |
927 | } | |
928 | ||
70b97a7f | 929 | static inline void finish_lock_switch(struct rq *rq, struct task_struct *prev) |
4866cde0 NP |
930 | { |
931 | #ifdef CONFIG_SMP | |
932 | /* | |
933 | * After ->oncpu is cleared, the task can be moved to a different CPU. | |
934 | * We must ensure this doesn't happen until the switch is completely | |
935 | * finished. | |
936 | */ | |
937 | smp_wmb(); | |
938 | prev->oncpu = 0; | |
939 | #endif | |
940 | #ifndef __ARCH_WANT_INTERRUPTS_ON_CTXSW | |
941 | local_irq_enable(); | |
1da177e4 | 942 | #endif |
4866cde0 NP |
943 | } |
944 | #endif /* __ARCH_WANT_UNLOCKED_CTXSW */ | |
1da177e4 | 945 | |
b29739f9 IM |
946 | /* |
947 | * __task_rq_lock - lock the runqueue a given task resides on. | |
948 | * Must be called interrupts disabled. | |
949 | */ | |
70b97a7f | 950 | static inline struct rq *__task_rq_lock(struct task_struct *p) |
b29739f9 IM |
951 | __acquires(rq->lock) |
952 | { | |
3a5c359a AK |
953 | for (;;) { |
954 | struct rq *rq = task_rq(p); | |
955 | spin_lock(&rq->lock); | |
956 | if (likely(rq == task_rq(p))) | |
957 | return rq; | |
b29739f9 | 958 | spin_unlock(&rq->lock); |
b29739f9 | 959 | } |
b29739f9 IM |
960 | } |
961 | ||
1da177e4 LT |
962 | /* |
963 | * task_rq_lock - lock the runqueue a given task resides on and disable | |
41a2d6cf | 964 | * interrupts. Note the ordering: we can safely lookup the task_rq without |
1da177e4 LT |
965 | * explicitly disabling preemption. |
966 | */ | |
70b97a7f | 967 | static struct rq *task_rq_lock(struct task_struct *p, unsigned long *flags) |
1da177e4 LT |
968 | __acquires(rq->lock) |
969 | { | |
70b97a7f | 970 | struct rq *rq; |
1da177e4 | 971 | |
3a5c359a AK |
972 | for (;;) { |
973 | local_irq_save(*flags); | |
974 | rq = task_rq(p); | |
975 | spin_lock(&rq->lock); | |
976 | if (likely(rq == task_rq(p))) | |
977 | return rq; | |
1da177e4 | 978 | spin_unlock_irqrestore(&rq->lock, *flags); |
1da177e4 | 979 | } |
1da177e4 LT |
980 | } |
981 | ||
ad474cac ON |
982 | void task_rq_unlock_wait(struct task_struct *p) |
983 | { | |
984 | struct rq *rq = task_rq(p); | |
985 | ||
986 | smp_mb(); /* spin-unlock-wait is not a full memory barrier */ | |
987 | spin_unlock_wait(&rq->lock); | |
988 | } | |
989 | ||
a9957449 | 990 | static void __task_rq_unlock(struct rq *rq) |
b29739f9 IM |
991 | __releases(rq->lock) |
992 | { | |
993 | spin_unlock(&rq->lock); | |
994 | } | |
995 | ||
70b97a7f | 996 | static inline void task_rq_unlock(struct rq *rq, unsigned long *flags) |
1da177e4 LT |
997 | __releases(rq->lock) |
998 | { | |
999 | spin_unlock_irqrestore(&rq->lock, *flags); | |
1000 | } | |
1001 | ||
1da177e4 | 1002 | /* |
cc2a73b5 | 1003 | * this_rq_lock - lock this runqueue and disable interrupts. |
1da177e4 | 1004 | */ |
a9957449 | 1005 | static struct rq *this_rq_lock(void) |
1da177e4 LT |
1006 | __acquires(rq->lock) |
1007 | { | |
70b97a7f | 1008 | struct rq *rq; |
1da177e4 LT |
1009 | |
1010 | local_irq_disable(); | |
1011 | rq = this_rq(); | |
1012 | spin_lock(&rq->lock); | |
1013 | ||
1014 | return rq; | |
1015 | } | |
1016 | ||
8f4d37ec PZ |
1017 | #ifdef CONFIG_SCHED_HRTICK |
1018 | /* | |
1019 | * Use HR-timers to deliver accurate preemption points. | |
1020 | * | |
1021 | * Its all a bit involved since we cannot program an hrt while holding the | |
1022 | * rq->lock. So what we do is store a state in in rq->hrtick_* and ask for a | |
1023 | * reschedule event. | |
1024 | * | |
1025 | * When we get rescheduled we reprogram the hrtick_timer outside of the | |
1026 | * rq->lock. | |
1027 | */ | |
8f4d37ec PZ |
1028 | |
1029 | /* | |
1030 | * Use hrtick when: | |
1031 | * - enabled by features | |
1032 | * - hrtimer is actually high res | |
1033 | */ | |
1034 | static inline int hrtick_enabled(struct rq *rq) | |
1035 | { | |
1036 | if (!sched_feat(HRTICK)) | |
1037 | return 0; | |
ba42059f | 1038 | if (!cpu_active(cpu_of(rq))) |
b328ca18 | 1039 | return 0; |
8f4d37ec PZ |
1040 | return hrtimer_is_hres_active(&rq->hrtick_timer); |
1041 | } | |
1042 | ||
8f4d37ec PZ |
1043 | static void hrtick_clear(struct rq *rq) |
1044 | { | |
1045 | if (hrtimer_active(&rq->hrtick_timer)) | |
1046 | hrtimer_cancel(&rq->hrtick_timer); | |
1047 | } | |
1048 | ||
8f4d37ec PZ |
1049 | /* |
1050 | * High-resolution timer tick. | |
1051 | * Runs from hardirq context with interrupts disabled. | |
1052 | */ | |
1053 | static enum hrtimer_restart hrtick(struct hrtimer *timer) | |
1054 | { | |
1055 | struct rq *rq = container_of(timer, struct rq, hrtick_timer); | |
1056 | ||
1057 | WARN_ON_ONCE(cpu_of(rq) != smp_processor_id()); | |
1058 | ||
1059 | spin_lock(&rq->lock); | |
3e51f33f | 1060 | update_rq_clock(rq); |
8f4d37ec PZ |
1061 | rq->curr->sched_class->task_tick(rq, rq->curr, 1); |
1062 | spin_unlock(&rq->lock); | |
1063 | ||
1064 | return HRTIMER_NORESTART; | |
1065 | } | |
1066 | ||
95e904c7 | 1067 | #ifdef CONFIG_SMP |
31656519 PZ |
1068 | /* |
1069 | * called from hardirq (IPI) context | |
1070 | */ | |
1071 | static void __hrtick_start(void *arg) | |
b328ca18 | 1072 | { |
31656519 | 1073 | struct rq *rq = arg; |
b328ca18 | 1074 | |
31656519 PZ |
1075 | spin_lock(&rq->lock); |
1076 | hrtimer_restart(&rq->hrtick_timer); | |
1077 | rq->hrtick_csd_pending = 0; | |
1078 | spin_unlock(&rq->lock); | |
b328ca18 PZ |
1079 | } |
1080 | ||
31656519 PZ |
1081 | /* |
1082 | * Called to set the hrtick timer state. | |
1083 | * | |
1084 | * called with rq->lock held and irqs disabled | |
1085 | */ | |
1086 | static void hrtick_start(struct rq *rq, u64 delay) | |
b328ca18 | 1087 | { |
31656519 PZ |
1088 | struct hrtimer *timer = &rq->hrtick_timer; |
1089 | ktime_t time = ktime_add_ns(timer->base->get_time(), delay); | |
b328ca18 | 1090 | |
cc584b21 | 1091 | hrtimer_set_expires(timer, time); |
31656519 PZ |
1092 | |
1093 | if (rq == this_rq()) { | |
1094 | hrtimer_restart(timer); | |
1095 | } else if (!rq->hrtick_csd_pending) { | |
1096 | __smp_call_function_single(cpu_of(rq), &rq->hrtick_csd); | |
1097 | rq->hrtick_csd_pending = 1; | |
1098 | } | |
b328ca18 PZ |
1099 | } |
1100 | ||
1101 | static int | |
1102 | hotplug_hrtick(struct notifier_block *nfb, unsigned long action, void *hcpu) | |
1103 | { | |
1104 | int cpu = (int)(long)hcpu; | |
1105 | ||
1106 | switch (action) { | |
1107 | case CPU_UP_CANCELED: | |
1108 | case CPU_UP_CANCELED_FROZEN: | |
1109 | case CPU_DOWN_PREPARE: | |
1110 | case CPU_DOWN_PREPARE_FROZEN: | |
1111 | case CPU_DEAD: | |
1112 | case CPU_DEAD_FROZEN: | |
31656519 | 1113 | hrtick_clear(cpu_rq(cpu)); |
b328ca18 PZ |
1114 | return NOTIFY_OK; |
1115 | } | |
1116 | ||
1117 | return NOTIFY_DONE; | |
1118 | } | |
1119 | ||
fa748203 | 1120 | static __init void init_hrtick(void) |
b328ca18 PZ |
1121 | { |
1122 | hotcpu_notifier(hotplug_hrtick, 0); | |
1123 | } | |
31656519 PZ |
1124 | #else |
1125 | /* | |
1126 | * Called to set the hrtick timer state. | |
1127 | * | |
1128 | * called with rq->lock held and irqs disabled | |
1129 | */ | |
1130 | static void hrtick_start(struct rq *rq, u64 delay) | |
1131 | { | |
1132 | hrtimer_start(&rq->hrtick_timer, ns_to_ktime(delay), HRTIMER_MODE_REL); | |
1133 | } | |
b328ca18 | 1134 | |
006c75f1 | 1135 | static inline void init_hrtick(void) |
8f4d37ec | 1136 | { |
8f4d37ec | 1137 | } |
31656519 | 1138 | #endif /* CONFIG_SMP */ |
8f4d37ec | 1139 | |
31656519 | 1140 | static void init_rq_hrtick(struct rq *rq) |
8f4d37ec | 1141 | { |
31656519 PZ |
1142 | #ifdef CONFIG_SMP |
1143 | rq->hrtick_csd_pending = 0; | |
8f4d37ec | 1144 | |
31656519 PZ |
1145 | rq->hrtick_csd.flags = 0; |
1146 | rq->hrtick_csd.func = __hrtick_start; | |
1147 | rq->hrtick_csd.info = rq; | |
1148 | #endif | |
8f4d37ec | 1149 | |
31656519 PZ |
1150 | hrtimer_init(&rq->hrtick_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); |
1151 | rq->hrtick_timer.function = hrtick; | |
8f4d37ec | 1152 | } |
006c75f1 | 1153 | #else /* CONFIG_SCHED_HRTICK */ |
8f4d37ec PZ |
1154 | static inline void hrtick_clear(struct rq *rq) |
1155 | { | |
1156 | } | |
1157 | ||
8f4d37ec PZ |
1158 | static inline void init_rq_hrtick(struct rq *rq) |
1159 | { | |
1160 | } | |
1161 | ||
b328ca18 PZ |
1162 | static inline void init_hrtick(void) |
1163 | { | |
1164 | } | |
006c75f1 | 1165 | #endif /* CONFIG_SCHED_HRTICK */ |
8f4d37ec | 1166 | |
c24d20db IM |
1167 | /* |
1168 | * resched_task - mark a task 'to be rescheduled now'. | |
1169 | * | |
1170 | * On UP this means the setting of the need_resched flag, on SMP it | |
1171 | * might also involve a cross-CPU call to trigger the scheduler on | |
1172 | * the target CPU. | |
1173 | */ | |
1174 | #ifdef CONFIG_SMP | |
1175 | ||
1176 | #ifndef tsk_is_polling | |
1177 | #define tsk_is_polling(t) test_tsk_thread_flag(t, TIF_POLLING_NRFLAG) | |
1178 | #endif | |
1179 | ||
31656519 | 1180 | static void resched_task(struct task_struct *p) |
c24d20db IM |
1181 | { |
1182 | int cpu; | |
1183 | ||
1184 | assert_spin_locked(&task_rq(p)->lock); | |
1185 | ||
31656519 | 1186 | if (unlikely(test_tsk_thread_flag(p, TIF_NEED_RESCHED))) |
c24d20db IM |
1187 | return; |
1188 | ||
31656519 | 1189 | set_tsk_thread_flag(p, TIF_NEED_RESCHED); |
c24d20db IM |
1190 | |
1191 | cpu = task_cpu(p); | |
1192 | if (cpu == smp_processor_id()) | |
1193 | return; | |
1194 | ||
1195 | /* NEED_RESCHED must be visible before we test polling */ | |
1196 | smp_mb(); | |
1197 | if (!tsk_is_polling(p)) | |
1198 | smp_send_reschedule(cpu); | |
1199 | } | |
1200 | ||
1201 | static void resched_cpu(int cpu) | |
1202 | { | |
1203 | struct rq *rq = cpu_rq(cpu); | |
1204 | unsigned long flags; | |
1205 | ||
1206 | if (!spin_trylock_irqsave(&rq->lock, flags)) | |
1207 | return; | |
1208 | resched_task(cpu_curr(cpu)); | |
1209 | spin_unlock_irqrestore(&rq->lock, flags); | |
1210 | } | |
06d8308c TG |
1211 | |
1212 | #ifdef CONFIG_NO_HZ | |
1213 | /* | |
1214 | * When add_timer_on() enqueues a timer into the timer wheel of an | |
1215 | * idle CPU then this timer might expire before the next timer event | |
1216 | * which is scheduled to wake up that CPU. In case of a completely | |
1217 | * idle system the next event might even be infinite time into the | |
1218 | * future. wake_up_idle_cpu() ensures that the CPU is woken up and | |
1219 | * leaves the inner idle loop so the newly added timer is taken into | |
1220 | * account when the CPU goes back to idle and evaluates the timer | |
1221 | * wheel for the next timer event. | |
1222 | */ | |
1223 | void wake_up_idle_cpu(int cpu) | |
1224 | { | |
1225 | struct rq *rq = cpu_rq(cpu); | |
1226 | ||
1227 | if (cpu == smp_processor_id()) | |
1228 | return; | |
1229 | ||
1230 | /* | |
1231 | * This is safe, as this function is called with the timer | |
1232 | * wheel base lock of (cpu) held. When the CPU is on the way | |
1233 | * to idle and has not yet set rq->curr to idle then it will | |
1234 | * be serialized on the timer wheel base lock and take the new | |
1235 | * timer into account automatically. | |
1236 | */ | |
1237 | if (rq->curr != rq->idle) | |
1238 | return; | |
1239 | ||
1240 | /* | |
1241 | * We can set TIF_RESCHED on the idle task of the other CPU | |
1242 | * lockless. The worst case is that the other CPU runs the | |
1243 | * idle task through an additional NOOP schedule() | |
1244 | */ | |
1245 | set_tsk_thread_flag(rq->idle, TIF_NEED_RESCHED); | |
1246 | ||
1247 | /* NEED_RESCHED must be visible before we test polling */ | |
1248 | smp_mb(); | |
1249 | if (!tsk_is_polling(rq->idle)) | |
1250 | smp_send_reschedule(cpu); | |
1251 | } | |
6d6bc0ad | 1252 | #endif /* CONFIG_NO_HZ */ |
06d8308c | 1253 | |
6d6bc0ad | 1254 | #else /* !CONFIG_SMP */ |
31656519 | 1255 | static void resched_task(struct task_struct *p) |
c24d20db IM |
1256 | { |
1257 | assert_spin_locked(&task_rq(p)->lock); | |
31656519 | 1258 | set_tsk_need_resched(p); |
c24d20db | 1259 | } |
6d6bc0ad | 1260 | #endif /* CONFIG_SMP */ |
c24d20db | 1261 | |
45bf76df IM |
1262 | #if BITS_PER_LONG == 32 |
1263 | # define WMULT_CONST (~0UL) | |
1264 | #else | |
1265 | # define WMULT_CONST (1UL << 32) | |
1266 | #endif | |
1267 | ||
1268 | #define WMULT_SHIFT 32 | |
1269 | ||
194081eb IM |
1270 | /* |
1271 | * Shift right and round: | |
1272 | */ | |
cf2ab469 | 1273 | #define SRR(x, y) (((x) + (1UL << ((y) - 1))) >> (y)) |
194081eb | 1274 | |
a7be37ac PZ |
1275 | /* |
1276 | * delta *= weight / lw | |
1277 | */ | |
cb1c4fc9 | 1278 | static unsigned long |
45bf76df IM |
1279 | calc_delta_mine(unsigned long delta_exec, unsigned long weight, |
1280 | struct load_weight *lw) | |
1281 | { | |
1282 | u64 tmp; | |
1283 | ||
7a232e03 LJ |
1284 | if (!lw->inv_weight) { |
1285 | if (BITS_PER_LONG > 32 && unlikely(lw->weight >= WMULT_CONST)) | |
1286 | lw->inv_weight = 1; | |
1287 | else | |
1288 | lw->inv_weight = 1 + (WMULT_CONST-lw->weight/2) | |
1289 | / (lw->weight+1); | |
1290 | } | |
45bf76df IM |
1291 | |
1292 | tmp = (u64)delta_exec * weight; | |
1293 | /* | |
1294 | * Check whether we'd overflow the 64-bit multiplication: | |
1295 | */ | |
194081eb | 1296 | if (unlikely(tmp > WMULT_CONST)) |
cf2ab469 | 1297 | tmp = SRR(SRR(tmp, WMULT_SHIFT/2) * lw->inv_weight, |
194081eb IM |
1298 | WMULT_SHIFT/2); |
1299 | else | |
cf2ab469 | 1300 | tmp = SRR(tmp * lw->inv_weight, WMULT_SHIFT); |
45bf76df | 1301 | |
ecf691da | 1302 | return (unsigned long)min(tmp, (u64)(unsigned long)LONG_MAX); |
45bf76df IM |
1303 | } |
1304 | ||
1091985b | 1305 | static inline void update_load_add(struct load_weight *lw, unsigned long inc) |
45bf76df IM |
1306 | { |
1307 | lw->weight += inc; | |
e89996ae | 1308 | lw->inv_weight = 0; |
45bf76df IM |
1309 | } |
1310 | ||
1091985b | 1311 | static inline void update_load_sub(struct load_weight *lw, unsigned long dec) |
45bf76df IM |
1312 | { |
1313 | lw->weight -= dec; | |
e89996ae | 1314 | lw->inv_weight = 0; |
45bf76df IM |
1315 | } |
1316 | ||
2dd73a4f PW |
1317 | /* |
1318 | * To aid in avoiding the subversion of "niceness" due to uneven distribution | |
1319 | * of tasks with abnormal "nice" values across CPUs the contribution that | |
1320 | * each task makes to its run queue's load is weighted according to its | |
41a2d6cf | 1321 | * scheduling class and "nice" value. For SCHED_NORMAL tasks this is just a |
2dd73a4f PW |
1322 | * scaled version of the new time slice allocation that they receive on time |
1323 | * slice expiry etc. | |
1324 | */ | |
1325 | ||
cce7ade8 PZ |
1326 | #define WEIGHT_IDLEPRIO 3 |
1327 | #define WMULT_IDLEPRIO 1431655765 | |
dd41f596 IM |
1328 | |
1329 | /* | |
1330 | * Nice levels are multiplicative, with a gentle 10% change for every | |
1331 | * nice level changed. I.e. when a CPU-bound task goes from nice 0 to | |
1332 | * nice 1, it will get ~10% less CPU time than another CPU-bound task | |
1333 | * that remained on nice 0. | |
1334 | * | |
1335 | * The "10% effect" is relative and cumulative: from _any_ nice level, | |
1336 | * if you go up 1 level, it's -10% CPU usage, if you go down 1 level | |
f9153ee6 IM |
1337 | * it's +10% CPU usage. (to achieve that we use a multiplier of 1.25. |
1338 | * If a task goes up by ~10% and another task goes down by ~10% then | |
1339 | * the relative distance between them is ~25%.) | |
dd41f596 IM |
1340 | */ |
1341 | static const int prio_to_weight[40] = { | |
254753dc IM |
1342 | /* -20 */ 88761, 71755, 56483, 46273, 36291, |
1343 | /* -15 */ 29154, 23254, 18705, 14949, 11916, | |
1344 | /* -10 */ 9548, 7620, 6100, 4904, 3906, | |
1345 | /* -5 */ 3121, 2501, 1991, 1586, 1277, | |
1346 | /* 0 */ 1024, 820, 655, 526, 423, | |
1347 | /* 5 */ 335, 272, 215, 172, 137, | |
1348 | /* 10 */ 110, 87, 70, 56, 45, | |
1349 | /* 15 */ 36, 29, 23, 18, 15, | |
dd41f596 IM |
1350 | }; |
1351 | ||
5714d2de IM |
1352 | /* |
1353 | * Inverse (2^32/x) values of the prio_to_weight[] array, precalculated. | |
1354 | * | |
1355 | * In cases where the weight does not change often, we can use the | |
1356 | * precalculated inverse to speed up arithmetics by turning divisions | |
1357 | * into multiplications: | |
1358 | */ | |
dd41f596 | 1359 | static const u32 prio_to_wmult[40] = { |
254753dc IM |
1360 | /* -20 */ 48388, 59856, 76040, 92818, 118348, |
1361 | /* -15 */ 147320, 184698, 229616, 287308, 360437, | |
1362 | /* -10 */ 449829, 563644, 704093, 875809, 1099582, | |
1363 | /* -5 */ 1376151, 1717300, 2157191, 2708050, 3363326, | |
1364 | /* 0 */ 4194304, 5237765, 6557202, 8165337, 10153587, | |
1365 | /* 5 */ 12820798, 15790321, 19976592, 24970740, 31350126, | |
1366 | /* 10 */ 39045157, 49367440, 61356676, 76695844, 95443717, | |
1367 | /* 15 */ 119304647, 148102320, 186737708, 238609294, 286331153, | |
dd41f596 | 1368 | }; |
2dd73a4f | 1369 | |
dd41f596 IM |
1370 | static void activate_task(struct rq *rq, struct task_struct *p, int wakeup); |
1371 | ||
1372 | /* | |
1373 | * runqueue iterator, to support SMP load-balancing between different | |
1374 | * scheduling classes, without having to expose their internal data | |
1375 | * structures to the load-balancing proper: | |
1376 | */ | |
1377 | struct rq_iterator { | |
1378 | void *arg; | |
1379 | struct task_struct *(*start)(void *); | |
1380 | struct task_struct *(*next)(void *); | |
1381 | }; | |
1382 | ||
e1d1484f PW |
1383 | #ifdef CONFIG_SMP |
1384 | static unsigned long | |
1385 | balance_tasks(struct rq *this_rq, int this_cpu, struct rq *busiest, | |
1386 | unsigned long max_load_move, struct sched_domain *sd, | |
1387 | enum cpu_idle_type idle, int *all_pinned, | |
1388 | int *this_best_prio, struct rq_iterator *iterator); | |
1389 | ||
1390 | static int | |
1391 | iter_move_one_task(struct rq *this_rq, int this_cpu, struct rq *busiest, | |
1392 | struct sched_domain *sd, enum cpu_idle_type idle, | |
1393 | struct rq_iterator *iterator); | |
e1d1484f | 1394 | #endif |
dd41f596 | 1395 | |
d842de87 SV |
1396 | #ifdef CONFIG_CGROUP_CPUACCT |
1397 | static void cpuacct_charge(struct task_struct *tsk, u64 cputime); | |
1398 | #else | |
1399 | static inline void cpuacct_charge(struct task_struct *tsk, u64 cputime) {} | |
1400 | #endif | |
1401 | ||
18d95a28 PZ |
1402 | static inline void inc_cpu_load(struct rq *rq, unsigned long load) |
1403 | { | |
1404 | update_load_add(&rq->load, load); | |
1405 | } | |
1406 | ||
1407 | static inline void dec_cpu_load(struct rq *rq, unsigned long load) | |
1408 | { | |
1409 | update_load_sub(&rq->load, load); | |
1410 | } | |
1411 | ||
7940ca36 | 1412 | #if (defined(CONFIG_SMP) && defined(CONFIG_FAIR_GROUP_SCHED)) || defined(CONFIG_RT_GROUP_SCHED) |
eb755805 | 1413 | typedef int (*tg_visitor)(struct task_group *, void *); |
c09595f6 PZ |
1414 | |
1415 | /* | |
1416 | * Iterate the full tree, calling @down when first entering a node and @up when | |
1417 | * leaving it for the final time. | |
1418 | */ | |
eb755805 | 1419 | static int walk_tg_tree(tg_visitor down, tg_visitor up, void *data) |
c09595f6 PZ |
1420 | { |
1421 | struct task_group *parent, *child; | |
eb755805 | 1422 | int ret; |
c09595f6 PZ |
1423 | |
1424 | rcu_read_lock(); | |
1425 | parent = &root_task_group; | |
1426 | down: | |
eb755805 PZ |
1427 | ret = (*down)(parent, data); |
1428 | if (ret) | |
1429 | goto out_unlock; | |
c09595f6 PZ |
1430 | list_for_each_entry_rcu(child, &parent->children, siblings) { |
1431 | parent = child; | |
1432 | goto down; | |
1433 | ||
1434 | up: | |
1435 | continue; | |
1436 | } | |
eb755805 PZ |
1437 | ret = (*up)(parent, data); |
1438 | if (ret) | |
1439 | goto out_unlock; | |
c09595f6 PZ |
1440 | |
1441 | child = parent; | |
1442 | parent = parent->parent; | |
1443 | if (parent) | |
1444 | goto up; | |
eb755805 | 1445 | out_unlock: |
c09595f6 | 1446 | rcu_read_unlock(); |
eb755805 PZ |
1447 | |
1448 | return ret; | |
c09595f6 PZ |
1449 | } |
1450 | ||
eb755805 PZ |
1451 | static int tg_nop(struct task_group *tg, void *data) |
1452 | { | |
1453 | return 0; | |
c09595f6 | 1454 | } |
eb755805 PZ |
1455 | #endif |
1456 | ||
1457 | #ifdef CONFIG_SMP | |
1458 | static unsigned long source_load(int cpu, int type); | |
1459 | static unsigned long target_load(int cpu, int type); | |
1460 | static int task_hot(struct task_struct *p, u64 now, struct sched_domain *sd); | |
1461 | ||
1462 | static unsigned long cpu_avg_load_per_task(int cpu) | |
1463 | { | |
1464 | struct rq *rq = cpu_rq(cpu); | |
af6d596f | 1465 | unsigned long nr_running = ACCESS_ONCE(rq->nr_running); |
eb755805 | 1466 | |
4cd42620 SR |
1467 | if (nr_running) |
1468 | rq->avg_load_per_task = rq->load.weight / nr_running; | |
a2d47777 BS |
1469 | else |
1470 | rq->avg_load_per_task = 0; | |
eb755805 PZ |
1471 | |
1472 | return rq->avg_load_per_task; | |
1473 | } | |
1474 | ||
1475 | #ifdef CONFIG_FAIR_GROUP_SCHED | |
c09595f6 | 1476 | |
c09595f6 PZ |
1477 | static void __set_se_shares(struct sched_entity *se, unsigned long shares); |
1478 | ||
1479 | /* | |
1480 | * Calculate and set the cpu's group shares. | |
1481 | */ | |
1482 | static void | |
ffda12a1 PZ |
1483 | update_group_shares_cpu(struct task_group *tg, int cpu, |
1484 | unsigned long sd_shares, unsigned long sd_rq_weight) | |
18d95a28 | 1485 | { |
c09595f6 PZ |
1486 | unsigned long shares; |
1487 | unsigned long rq_weight; | |
1488 | ||
c8cba857 | 1489 | if (!tg->se[cpu]) |
c09595f6 PZ |
1490 | return; |
1491 | ||
ec4e0e2f | 1492 | rq_weight = tg->cfs_rq[cpu]->rq_weight; |
c8cba857 | 1493 | |
c09595f6 PZ |
1494 | /* |
1495 | * \Sum shares * rq_weight | |
1496 | * shares = ----------------------- | |
1497 | * \Sum rq_weight | |
1498 | * | |
1499 | */ | |
ec4e0e2f | 1500 | shares = (sd_shares * rq_weight) / sd_rq_weight; |
ffda12a1 | 1501 | shares = clamp_t(unsigned long, shares, MIN_SHARES, MAX_SHARES); |
c09595f6 | 1502 | |
ffda12a1 PZ |
1503 | if (abs(shares - tg->se[cpu]->load.weight) > |
1504 | sysctl_sched_shares_thresh) { | |
1505 | struct rq *rq = cpu_rq(cpu); | |
1506 | unsigned long flags; | |
c09595f6 | 1507 | |
ffda12a1 | 1508 | spin_lock_irqsave(&rq->lock, flags); |
ec4e0e2f | 1509 | tg->cfs_rq[cpu]->shares = shares; |
c09595f6 | 1510 | |
ffda12a1 PZ |
1511 | __set_se_shares(tg->se[cpu], shares); |
1512 | spin_unlock_irqrestore(&rq->lock, flags); | |
1513 | } | |
18d95a28 | 1514 | } |
c09595f6 PZ |
1515 | |
1516 | /* | |
c8cba857 PZ |
1517 | * Re-compute the task group their per cpu shares over the given domain. |
1518 | * This needs to be done in a bottom-up fashion because the rq weight of a | |
1519 | * parent group depends on the shares of its child groups. | |
c09595f6 | 1520 | */ |
eb755805 | 1521 | static int tg_shares_up(struct task_group *tg, void *data) |
c09595f6 | 1522 | { |
ec4e0e2f | 1523 | unsigned long weight, rq_weight = 0; |
c8cba857 | 1524 | unsigned long shares = 0; |
eb755805 | 1525 | struct sched_domain *sd = data; |
c8cba857 | 1526 | int i; |
c09595f6 | 1527 | |
758b2cdc | 1528 | for_each_cpu(i, sched_domain_span(sd)) { |
ec4e0e2f KC |
1529 | /* |
1530 | * If there are currently no tasks on the cpu pretend there | |
1531 | * is one of average load so that when a new task gets to | |
1532 | * run here it will not get delayed by group starvation. | |
1533 | */ | |
1534 | weight = tg->cfs_rq[i]->load.weight; | |
1535 | if (!weight) | |
1536 | weight = NICE_0_LOAD; | |
1537 | ||
1538 | tg->cfs_rq[i]->rq_weight = weight; | |
1539 | rq_weight += weight; | |
c8cba857 | 1540 | shares += tg->cfs_rq[i]->shares; |
c09595f6 | 1541 | } |
c09595f6 | 1542 | |
c8cba857 PZ |
1543 | if ((!shares && rq_weight) || shares > tg->shares) |
1544 | shares = tg->shares; | |
1545 | ||
1546 | if (!sd->parent || !(sd->parent->flags & SD_LOAD_BALANCE)) | |
1547 | shares = tg->shares; | |
c09595f6 | 1548 | |
758b2cdc | 1549 | for_each_cpu(i, sched_domain_span(sd)) |
ffda12a1 | 1550 | update_group_shares_cpu(tg, i, shares, rq_weight); |
eb755805 PZ |
1551 | |
1552 | return 0; | |
c09595f6 PZ |
1553 | } |
1554 | ||
1555 | /* | |
c8cba857 PZ |
1556 | * Compute the cpu's hierarchical load factor for each task group. |
1557 | * This needs to be done in a top-down fashion because the load of a child | |
1558 | * group is a fraction of its parents load. | |
c09595f6 | 1559 | */ |
eb755805 | 1560 | static int tg_load_down(struct task_group *tg, void *data) |
c09595f6 | 1561 | { |
c8cba857 | 1562 | unsigned long load; |
eb755805 | 1563 | long cpu = (long)data; |
c09595f6 | 1564 | |
c8cba857 PZ |
1565 | if (!tg->parent) { |
1566 | load = cpu_rq(cpu)->load.weight; | |
1567 | } else { | |
1568 | load = tg->parent->cfs_rq[cpu]->h_load; | |
1569 | load *= tg->cfs_rq[cpu]->shares; | |
1570 | load /= tg->parent->cfs_rq[cpu]->load.weight + 1; | |
1571 | } | |
c09595f6 | 1572 | |
c8cba857 | 1573 | tg->cfs_rq[cpu]->h_load = load; |
c09595f6 | 1574 | |
eb755805 | 1575 | return 0; |
c09595f6 PZ |
1576 | } |
1577 | ||
c8cba857 | 1578 | static void update_shares(struct sched_domain *sd) |
4d8d595d | 1579 | { |
2398f2c6 PZ |
1580 | u64 now = cpu_clock(raw_smp_processor_id()); |
1581 | s64 elapsed = now - sd->last_update; | |
1582 | ||
1583 | if (elapsed >= (s64)(u64)sysctl_sched_shares_ratelimit) { | |
1584 | sd->last_update = now; | |
eb755805 | 1585 | walk_tg_tree(tg_nop, tg_shares_up, sd); |
2398f2c6 | 1586 | } |
4d8d595d PZ |
1587 | } |
1588 | ||
3e5459b4 PZ |
1589 | static void update_shares_locked(struct rq *rq, struct sched_domain *sd) |
1590 | { | |
1591 | spin_unlock(&rq->lock); | |
1592 | update_shares(sd); | |
1593 | spin_lock(&rq->lock); | |
1594 | } | |
1595 | ||
eb755805 | 1596 | static void update_h_load(long cpu) |
c09595f6 | 1597 | { |
eb755805 | 1598 | walk_tg_tree(tg_load_down, tg_nop, (void *)cpu); |
c09595f6 PZ |
1599 | } |
1600 | ||
c09595f6 PZ |
1601 | #else |
1602 | ||
c8cba857 | 1603 | static inline void update_shares(struct sched_domain *sd) |
4d8d595d PZ |
1604 | { |
1605 | } | |
1606 | ||
3e5459b4 PZ |
1607 | static inline void update_shares_locked(struct rq *rq, struct sched_domain *sd) |
1608 | { | |
1609 | } | |
1610 | ||
18d95a28 PZ |
1611 | #endif |
1612 | ||
70574a99 AD |
1613 | /* |
1614 | * double_lock_balance - lock the busiest runqueue, this_rq is locked already. | |
1615 | */ | |
1616 | static int double_lock_balance(struct rq *this_rq, struct rq *busiest) | |
1617 | __releases(this_rq->lock) | |
1618 | __acquires(busiest->lock) | |
1619 | __acquires(this_rq->lock) | |
1620 | { | |
1621 | int ret = 0; | |
1622 | ||
1623 | if (unlikely(!irqs_disabled())) { | |
1624 | /* printk() doesn't work good under rq->lock */ | |
1625 | spin_unlock(&this_rq->lock); | |
1626 | BUG_ON(1); | |
1627 | } | |
1628 | if (unlikely(!spin_trylock(&busiest->lock))) { | |
1629 | if (busiest < this_rq) { | |
1630 | spin_unlock(&this_rq->lock); | |
1631 | spin_lock(&busiest->lock); | |
1632 | spin_lock_nested(&this_rq->lock, SINGLE_DEPTH_NESTING); | |
1633 | ret = 1; | |
1634 | } else | |
1635 | spin_lock_nested(&busiest->lock, SINGLE_DEPTH_NESTING); | |
1636 | } | |
1637 | return ret; | |
1638 | } | |
1639 | ||
1640 | static inline void double_unlock_balance(struct rq *this_rq, struct rq *busiest) | |
1641 | __releases(busiest->lock) | |
1642 | { | |
1643 | spin_unlock(&busiest->lock); | |
1644 | lock_set_subclass(&this_rq->lock.dep_map, 0, _RET_IP_); | |
1645 | } | |
18d95a28 PZ |
1646 | #endif |
1647 | ||
30432094 | 1648 | #ifdef CONFIG_FAIR_GROUP_SCHED |
34e83e85 IM |
1649 | static void cfs_rq_set_shares(struct cfs_rq *cfs_rq, unsigned long shares) |
1650 | { | |
30432094 | 1651 | #ifdef CONFIG_SMP |
34e83e85 IM |
1652 | cfs_rq->shares = shares; |
1653 | #endif | |
1654 | } | |
30432094 | 1655 | #endif |
e7693a36 | 1656 | |
dd41f596 | 1657 | #include "sched_stats.h" |
dd41f596 | 1658 | #include "sched_idletask.c" |
5522d5d5 IM |
1659 | #include "sched_fair.c" |
1660 | #include "sched_rt.c" | |
dd41f596 IM |
1661 | #ifdef CONFIG_SCHED_DEBUG |
1662 | # include "sched_debug.c" | |
1663 | #endif | |
1664 | ||
1665 | #define sched_class_highest (&rt_sched_class) | |
1f11eb6a GH |
1666 | #define for_each_class(class) \ |
1667 | for (class = sched_class_highest; class; class = class->next) | |
dd41f596 | 1668 | |
c09595f6 | 1669 | static void inc_nr_running(struct rq *rq) |
9c217245 IM |
1670 | { |
1671 | rq->nr_running++; | |
9c217245 IM |
1672 | } |
1673 | ||
c09595f6 | 1674 | static void dec_nr_running(struct rq *rq) |
9c217245 IM |
1675 | { |
1676 | rq->nr_running--; | |
9c217245 IM |
1677 | } |
1678 | ||
45bf76df IM |
1679 | static void set_load_weight(struct task_struct *p) |
1680 | { | |
1681 | if (task_has_rt_policy(p)) { | |
dd41f596 IM |
1682 | p->se.load.weight = prio_to_weight[0] * 2; |
1683 | p->se.load.inv_weight = prio_to_wmult[0] >> 1; | |
1684 | return; | |
1685 | } | |
45bf76df | 1686 | |
dd41f596 IM |
1687 | /* |
1688 | * SCHED_IDLE tasks get minimal weight: | |
1689 | */ | |
1690 | if (p->policy == SCHED_IDLE) { | |
1691 | p->se.load.weight = WEIGHT_IDLEPRIO; | |
1692 | p->se.load.inv_weight = WMULT_IDLEPRIO; | |
1693 | return; | |
1694 | } | |
71f8bd46 | 1695 | |
dd41f596 IM |
1696 | p->se.load.weight = prio_to_weight[p->static_prio - MAX_RT_PRIO]; |
1697 | p->se.load.inv_weight = prio_to_wmult[p->static_prio - MAX_RT_PRIO]; | |
71f8bd46 IM |
1698 | } |
1699 | ||
2087a1ad GH |
1700 | static void update_avg(u64 *avg, u64 sample) |
1701 | { | |
1702 | s64 diff = sample - *avg; | |
1703 | *avg += diff >> 3; | |
1704 | } | |
1705 | ||
8159f87e | 1706 | static void enqueue_task(struct rq *rq, struct task_struct *p, int wakeup) |
71f8bd46 | 1707 | { |
dd41f596 | 1708 | sched_info_queued(p); |
fd390f6a | 1709 | p->sched_class->enqueue_task(rq, p, wakeup); |
dd41f596 | 1710 | p->se.on_rq = 1; |
71f8bd46 IM |
1711 | } |
1712 | ||
69be72c1 | 1713 | static void dequeue_task(struct rq *rq, struct task_struct *p, int sleep) |
71f8bd46 | 1714 | { |
2087a1ad GH |
1715 | if (sleep && p->se.last_wakeup) { |
1716 | update_avg(&p->se.avg_overlap, | |
1717 | p->se.sum_exec_runtime - p->se.last_wakeup); | |
1718 | p->se.last_wakeup = 0; | |
1719 | } | |
1720 | ||
46ac22ba | 1721 | sched_info_dequeued(p); |
f02231e5 | 1722 | p->sched_class->dequeue_task(rq, p, sleep); |
dd41f596 | 1723 | p->se.on_rq = 0; |
71f8bd46 IM |
1724 | } |
1725 | ||
14531189 | 1726 | /* |
dd41f596 | 1727 | * __normal_prio - return the priority that is based on the static prio |
14531189 | 1728 | */ |
14531189 IM |
1729 | static inline int __normal_prio(struct task_struct *p) |
1730 | { | |
dd41f596 | 1731 | return p->static_prio; |
14531189 IM |
1732 | } |
1733 | ||
b29739f9 IM |
1734 | /* |
1735 | * Calculate the expected normal priority: i.e. priority | |
1736 | * without taking RT-inheritance into account. Might be | |
1737 | * boosted by interactivity modifiers. Changes upon fork, | |
1738 | * setprio syscalls, and whenever the interactivity | |
1739 | * estimator recalculates. | |
1740 | */ | |
36c8b586 | 1741 | static inline int normal_prio(struct task_struct *p) |
b29739f9 IM |
1742 | { |
1743 | int prio; | |
1744 | ||
e05606d3 | 1745 | if (task_has_rt_policy(p)) |
b29739f9 IM |
1746 | prio = MAX_RT_PRIO-1 - p->rt_priority; |
1747 | else | |
1748 | prio = __normal_prio(p); | |
1749 | return prio; | |
1750 | } | |
1751 | ||
1752 | /* | |
1753 | * Calculate the current priority, i.e. the priority | |
1754 | * taken into account by the scheduler. This value might | |
1755 | * be boosted by RT tasks, or might be boosted by | |
1756 | * interactivity modifiers. Will be RT if the task got | |
1757 | * RT-boosted. If not then it returns p->normal_prio. | |
1758 | */ | |
36c8b586 | 1759 | static int effective_prio(struct task_struct *p) |
b29739f9 IM |
1760 | { |
1761 | p->normal_prio = normal_prio(p); | |
1762 | /* | |
1763 | * If we are RT tasks or we were boosted to RT priority, | |
1764 | * keep the priority unchanged. Otherwise, update priority | |
1765 | * to the normal priority: | |
1766 | */ | |
1767 | if (!rt_prio(p->prio)) | |
1768 | return p->normal_prio; | |
1769 | return p->prio; | |
1770 | } | |
1771 | ||
1da177e4 | 1772 | /* |
dd41f596 | 1773 | * activate_task - move a task to the runqueue. |
1da177e4 | 1774 | */ |
dd41f596 | 1775 | static void activate_task(struct rq *rq, struct task_struct *p, int wakeup) |
1da177e4 | 1776 | { |
d9514f6c | 1777 | if (task_contributes_to_load(p)) |
dd41f596 | 1778 | rq->nr_uninterruptible--; |
1da177e4 | 1779 | |
8159f87e | 1780 | enqueue_task(rq, p, wakeup); |
c09595f6 | 1781 | inc_nr_running(rq); |
1da177e4 LT |
1782 | } |
1783 | ||
1da177e4 LT |
1784 | /* |
1785 | * deactivate_task - remove a task from the runqueue. | |
1786 | */ | |
2e1cb74a | 1787 | static void deactivate_task(struct rq *rq, struct task_struct *p, int sleep) |
1da177e4 | 1788 | { |
d9514f6c | 1789 | if (task_contributes_to_load(p)) |
dd41f596 IM |
1790 | rq->nr_uninterruptible++; |
1791 | ||
69be72c1 | 1792 | dequeue_task(rq, p, sleep); |
c09595f6 | 1793 | dec_nr_running(rq); |
1da177e4 LT |
1794 | } |
1795 | ||
1da177e4 LT |
1796 | /** |
1797 | * task_curr - is this task currently executing on a CPU? | |
1798 | * @p: the task in question. | |
1799 | */ | |
36c8b586 | 1800 | inline int task_curr(const struct task_struct *p) |
1da177e4 LT |
1801 | { |
1802 | return cpu_curr(task_cpu(p)) == p; | |
1803 | } | |
1804 | ||
dd41f596 IM |
1805 | static inline void __set_task_cpu(struct task_struct *p, unsigned int cpu) |
1806 | { | |
6f505b16 | 1807 | set_task_rq(p, cpu); |
dd41f596 | 1808 | #ifdef CONFIG_SMP |
ce96b5ac DA |
1809 | /* |
1810 | * After ->cpu is set up to a new value, task_rq_lock(p, ...) can be | |
1811 | * successfuly executed on another CPU. We must ensure that updates of | |
1812 | * per-task data have been completed by this moment. | |
1813 | */ | |
1814 | smp_wmb(); | |
dd41f596 | 1815 | task_thread_info(p)->cpu = cpu; |
dd41f596 | 1816 | #endif |
2dd73a4f PW |
1817 | } |
1818 | ||
cb469845 SR |
1819 | static inline void check_class_changed(struct rq *rq, struct task_struct *p, |
1820 | const struct sched_class *prev_class, | |
1821 | int oldprio, int running) | |
1822 | { | |
1823 | if (prev_class != p->sched_class) { | |
1824 | if (prev_class->switched_from) | |
1825 | prev_class->switched_from(rq, p, running); | |
1826 | p->sched_class->switched_to(rq, p, running); | |
1827 | } else | |
1828 | p->sched_class->prio_changed(rq, p, oldprio, running); | |
1829 | } | |
1830 | ||
1da177e4 | 1831 | #ifdef CONFIG_SMP |
c65cc870 | 1832 | |
e958b360 TG |
1833 | /* Used instead of source_load when we know the type == 0 */ |
1834 | static unsigned long weighted_cpuload(const int cpu) | |
1835 | { | |
1836 | return cpu_rq(cpu)->load.weight; | |
1837 | } | |
1838 | ||
cc367732 IM |
1839 | /* |
1840 | * Is this task likely cache-hot: | |
1841 | */ | |
e7693a36 | 1842 | static int |
cc367732 IM |
1843 | task_hot(struct task_struct *p, u64 now, struct sched_domain *sd) |
1844 | { | |
1845 | s64 delta; | |
1846 | ||
f540a608 IM |
1847 | /* |
1848 | * Buddy candidates are cache hot: | |
1849 | */ | |
4793241b PZ |
1850 | if (sched_feat(CACHE_HOT_BUDDY) && |
1851 | (&p->se == cfs_rq_of(&p->se)->next || | |
1852 | &p->se == cfs_rq_of(&p->se)->last)) | |
f540a608 IM |
1853 | return 1; |
1854 | ||
cc367732 IM |
1855 | if (p->sched_class != &fair_sched_class) |
1856 | return 0; | |
1857 | ||
6bc1665b IM |
1858 | if (sysctl_sched_migration_cost == -1) |
1859 | return 1; | |
1860 | if (sysctl_sched_migration_cost == 0) | |
1861 | return 0; | |
1862 | ||
cc367732 IM |
1863 | delta = now - p->se.exec_start; |
1864 | ||
1865 | return delta < (s64)sysctl_sched_migration_cost; | |
1866 | } | |
1867 | ||
1868 | ||
dd41f596 | 1869 | void set_task_cpu(struct task_struct *p, unsigned int new_cpu) |
c65cc870 | 1870 | { |
dd41f596 IM |
1871 | int old_cpu = task_cpu(p); |
1872 | struct rq *old_rq = cpu_rq(old_cpu), *new_rq = cpu_rq(new_cpu); | |
2830cf8c SV |
1873 | struct cfs_rq *old_cfsrq = task_cfs_rq(p), |
1874 | *new_cfsrq = cpu_cfs_rq(old_cfsrq, new_cpu); | |
bbdba7c0 | 1875 | u64 clock_offset; |
dd41f596 IM |
1876 | |
1877 | clock_offset = old_rq->clock - new_rq->clock; | |
6cfb0d5d | 1878 | |
cbc34ed1 PZ |
1879 | trace_sched_migrate_task(p, task_cpu(p), new_cpu); |
1880 | ||
6cfb0d5d IM |
1881 | #ifdef CONFIG_SCHEDSTATS |
1882 | if (p->se.wait_start) | |
1883 | p->se.wait_start -= clock_offset; | |
dd41f596 IM |
1884 | if (p->se.sleep_start) |
1885 | p->se.sleep_start -= clock_offset; | |
1886 | if (p->se.block_start) | |
1887 | p->se.block_start -= clock_offset; | |
cc367732 IM |
1888 | if (old_cpu != new_cpu) { |
1889 | schedstat_inc(p, se.nr_migrations); | |
1890 | if (task_hot(p, old_rq->clock, NULL)) | |
1891 | schedstat_inc(p, se.nr_forced2_migrations); | |
1892 | } | |
6cfb0d5d | 1893 | #endif |
2830cf8c SV |
1894 | p->se.vruntime -= old_cfsrq->min_vruntime - |
1895 | new_cfsrq->min_vruntime; | |
dd41f596 IM |
1896 | |
1897 | __set_task_cpu(p, new_cpu); | |
c65cc870 IM |
1898 | } |
1899 | ||
70b97a7f | 1900 | struct migration_req { |
1da177e4 | 1901 | struct list_head list; |
1da177e4 | 1902 | |
36c8b586 | 1903 | struct task_struct *task; |
1da177e4 LT |
1904 | int dest_cpu; |
1905 | ||
1da177e4 | 1906 | struct completion done; |
70b97a7f | 1907 | }; |
1da177e4 LT |
1908 | |
1909 | /* | |
1910 | * The task's runqueue lock must be held. | |
1911 | * Returns true if you have to wait for migration thread. | |
1912 | */ | |
36c8b586 | 1913 | static int |
70b97a7f | 1914 | migrate_task(struct task_struct *p, int dest_cpu, struct migration_req *req) |
1da177e4 | 1915 | { |
70b97a7f | 1916 | struct rq *rq = task_rq(p); |
1da177e4 LT |
1917 | |
1918 | /* | |
1919 | * If the task is not on a runqueue (and not running), then | |
1920 | * it is sufficient to simply update the task's cpu field. | |
1921 | */ | |
dd41f596 | 1922 | if (!p->se.on_rq && !task_running(rq, p)) { |
1da177e4 LT |
1923 | set_task_cpu(p, dest_cpu); |
1924 | return 0; | |
1925 | } | |
1926 | ||
1927 | init_completion(&req->done); | |
1da177e4 LT |
1928 | req->task = p; |
1929 | req->dest_cpu = dest_cpu; | |
1930 | list_add(&req->list, &rq->migration_queue); | |
48f24c4d | 1931 | |
1da177e4 LT |
1932 | return 1; |
1933 | } | |
1934 | ||
1935 | /* | |
1936 | * wait_task_inactive - wait for a thread to unschedule. | |
1937 | * | |
85ba2d86 RM |
1938 | * If @match_state is nonzero, it's the @p->state value just checked and |
1939 | * not expected to change. If it changes, i.e. @p might have woken up, | |
1940 | * then return zero. When we succeed in waiting for @p to be off its CPU, | |
1941 | * we return a positive number (its total switch count). If a second call | |
1942 | * a short while later returns the same number, the caller can be sure that | |
1943 | * @p has remained unscheduled the whole time. | |
1944 | * | |
1da177e4 LT |
1945 | * The caller must ensure that the task *will* unschedule sometime soon, |
1946 | * else this function might spin for a *long* time. This function can't | |
1947 | * be called with interrupts off, or it may introduce deadlock with | |
1948 | * smp_call_function() if an IPI is sent by the same process we are | |
1949 | * waiting to become inactive. | |
1950 | */ | |
85ba2d86 | 1951 | unsigned long wait_task_inactive(struct task_struct *p, long match_state) |
1da177e4 LT |
1952 | { |
1953 | unsigned long flags; | |
dd41f596 | 1954 | int running, on_rq; |
85ba2d86 | 1955 | unsigned long ncsw; |
70b97a7f | 1956 | struct rq *rq; |
1da177e4 | 1957 | |
3a5c359a AK |
1958 | for (;;) { |
1959 | /* | |
1960 | * We do the initial early heuristics without holding | |
1961 | * any task-queue locks at all. We'll only try to get | |
1962 | * the runqueue lock when things look like they will | |
1963 | * work out! | |
1964 | */ | |
1965 | rq = task_rq(p); | |
fa490cfd | 1966 | |
3a5c359a AK |
1967 | /* |
1968 | * If the task is actively running on another CPU | |
1969 | * still, just relax and busy-wait without holding | |
1970 | * any locks. | |
1971 | * | |
1972 | * NOTE! Since we don't hold any locks, it's not | |
1973 | * even sure that "rq" stays as the right runqueue! | |
1974 | * But we don't care, since "task_running()" will | |
1975 | * return false if the runqueue has changed and p | |
1976 | * is actually now running somewhere else! | |
1977 | */ | |
85ba2d86 RM |
1978 | while (task_running(rq, p)) { |
1979 | if (match_state && unlikely(p->state != match_state)) | |
1980 | return 0; | |
3a5c359a | 1981 | cpu_relax(); |
85ba2d86 | 1982 | } |
fa490cfd | 1983 | |
3a5c359a AK |
1984 | /* |
1985 | * Ok, time to look more closely! We need the rq | |
1986 | * lock now, to be *sure*. If we're wrong, we'll | |
1987 | * just go back and repeat. | |
1988 | */ | |
1989 | rq = task_rq_lock(p, &flags); | |
0a16b607 | 1990 | trace_sched_wait_task(rq, p); |
3a5c359a AK |
1991 | running = task_running(rq, p); |
1992 | on_rq = p->se.on_rq; | |
85ba2d86 | 1993 | ncsw = 0; |
f31e11d8 | 1994 | if (!match_state || p->state == match_state) |
93dcf55f | 1995 | ncsw = p->nvcsw | LONG_MIN; /* sets MSB */ |
3a5c359a | 1996 | task_rq_unlock(rq, &flags); |
fa490cfd | 1997 | |
85ba2d86 RM |
1998 | /* |
1999 | * If it changed from the expected state, bail out now. | |
2000 | */ | |
2001 | if (unlikely(!ncsw)) | |
2002 | break; | |
2003 | ||
3a5c359a AK |
2004 | /* |
2005 | * Was it really running after all now that we | |
2006 | * checked with the proper locks actually held? | |
2007 | * | |
2008 | * Oops. Go back and try again.. | |
2009 | */ | |
2010 | if (unlikely(running)) { | |
2011 | cpu_relax(); | |
2012 | continue; | |
2013 | } | |
fa490cfd | 2014 | |
3a5c359a AK |
2015 | /* |
2016 | * It's not enough that it's not actively running, | |
2017 | * it must be off the runqueue _entirely_, and not | |
2018 | * preempted! | |
2019 | * | |
2020 | * So if it wa still runnable (but just not actively | |
2021 | * running right now), it's preempted, and we should | |
2022 | * yield - it could be a while. | |
2023 | */ | |
2024 | if (unlikely(on_rq)) { | |
2025 | schedule_timeout_uninterruptible(1); | |
2026 | continue; | |
2027 | } | |
fa490cfd | 2028 | |
3a5c359a AK |
2029 | /* |
2030 | * Ahh, all good. It wasn't running, and it wasn't | |
2031 | * runnable, which means that it will never become | |
2032 | * running in the future either. We're all done! | |
2033 | */ | |
2034 | break; | |
2035 | } | |
85ba2d86 RM |
2036 | |
2037 | return ncsw; | |
1da177e4 LT |
2038 | } |
2039 | ||
2040 | /*** | |
2041 | * kick_process - kick a running thread to enter/exit the kernel | |
2042 | * @p: the to-be-kicked thread | |
2043 | * | |
2044 | * Cause a process which is running on another CPU to enter | |
2045 | * kernel-mode, without any delay. (to get signals handled.) | |
2046 | * | |
2047 | * NOTE: this function doesnt have to take the runqueue lock, | |
2048 | * because all it wants to ensure is that the remote task enters | |
2049 | * the kernel. If the IPI races and the task has been migrated | |
2050 | * to another CPU then no harm is done and the purpose has been | |
2051 | * achieved as well. | |
2052 | */ | |
36c8b586 | 2053 | void kick_process(struct task_struct *p) |
1da177e4 LT |
2054 | { |
2055 | int cpu; | |
2056 | ||
2057 | preempt_disable(); | |
2058 | cpu = task_cpu(p); | |
2059 | if ((cpu != smp_processor_id()) && task_curr(p)) | |
2060 | smp_send_reschedule(cpu); | |
2061 | preempt_enable(); | |
2062 | } | |
2063 | ||
2064 | /* | |
2dd73a4f PW |
2065 | * Return a low guess at the load of a migration-source cpu weighted |
2066 | * according to the scheduling class and "nice" value. | |
1da177e4 LT |
2067 | * |
2068 | * We want to under-estimate the load of migration sources, to | |
2069 | * balance conservatively. | |
2070 | */ | |
a9957449 | 2071 | static unsigned long source_load(int cpu, int type) |
1da177e4 | 2072 | { |
70b97a7f | 2073 | struct rq *rq = cpu_rq(cpu); |
dd41f596 | 2074 | unsigned long total = weighted_cpuload(cpu); |
2dd73a4f | 2075 | |
93b75217 | 2076 | if (type == 0 || !sched_feat(LB_BIAS)) |
dd41f596 | 2077 | return total; |
b910472d | 2078 | |
dd41f596 | 2079 | return min(rq->cpu_load[type-1], total); |
1da177e4 LT |
2080 | } |
2081 | ||
2082 | /* | |
2dd73a4f PW |
2083 | * Return a high guess at the load of a migration-target cpu weighted |
2084 | * according to the scheduling class and "nice" value. | |
1da177e4 | 2085 | */ |
a9957449 | 2086 | static unsigned long target_load(int cpu, int type) |
1da177e4 | 2087 | { |
70b97a7f | 2088 | struct rq *rq = cpu_rq(cpu); |
dd41f596 | 2089 | unsigned long total = weighted_cpuload(cpu); |
2dd73a4f | 2090 | |
93b75217 | 2091 | if (type == 0 || !sched_feat(LB_BIAS)) |
dd41f596 | 2092 | return total; |
3b0bd9bc | 2093 | |
dd41f596 | 2094 | return max(rq->cpu_load[type-1], total); |
2dd73a4f PW |
2095 | } |
2096 | ||
147cbb4b NP |
2097 | /* |
2098 | * find_idlest_group finds and returns the least busy CPU group within the | |
2099 | * domain. | |
2100 | */ | |
2101 | static struct sched_group * | |
2102 | find_idlest_group(struct sched_domain *sd, struct task_struct *p, int this_cpu) | |
2103 | { | |
2104 | struct sched_group *idlest = NULL, *this = NULL, *group = sd->groups; | |
2105 | unsigned long min_load = ULONG_MAX, this_load = 0; | |
2106 | int load_idx = sd->forkexec_idx; | |
2107 | int imbalance = 100 + (sd->imbalance_pct-100)/2; | |
2108 | ||
2109 | do { | |
2110 | unsigned long load, avg_load; | |
2111 | int local_group; | |
2112 | int i; | |
2113 | ||
da5a5522 | 2114 | /* Skip over this group if it has no CPUs allowed */ |
758b2cdc RR |
2115 | if (!cpumask_intersects(sched_group_cpus(group), |
2116 | &p->cpus_allowed)) | |
3a5c359a | 2117 | continue; |
da5a5522 | 2118 | |
758b2cdc RR |
2119 | local_group = cpumask_test_cpu(this_cpu, |
2120 | sched_group_cpus(group)); | |
147cbb4b NP |
2121 | |
2122 | /* Tally up the load of all CPUs in the group */ | |
2123 | avg_load = 0; | |
2124 | ||
758b2cdc | 2125 | for_each_cpu(i, sched_group_cpus(group)) { |
147cbb4b NP |
2126 | /* Bias balancing toward cpus of our domain */ |
2127 | if (local_group) | |
2128 | load = source_load(i, load_idx); | |
2129 | else | |
2130 | load = target_load(i, load_idx); | |
2131 | ||
2132 | avg_load += load; | |
2133 | } | |
2134 | ||
2135 | /* Adjust by relative CPU power of the group */ | |
5517d86b ED |
2136 | avg_load = sg_div_cpu_power(group, |
2137 | avg_load * SCHED_LOAD_SCALE); | |
147cbb4b NP |
2138 | |
2139 | if (local_group) { | |
2140 | this_load = avg_load; | |
2141 | this = group; | |
2142 | } else if (avg_load < min_load) { | |
2143 | min_load = avg_load; | |
2144 | idlest = group; | |
2145 | } | |
3a5c359a | 2146 | } while (group = group->next, group != sd->groups); |
147cbb4b NP |
2147 | |
2148 | if (!idlest || 100*this_load < imbalance*min_load) | |
2149 | return NULL; | |
2150 | return idlest; | |
2151 | } | |
2152 | ||
2153 | /* | |
0feaece9 | 2154 | * find_idlest_cpu - find the idlest cpu among the cpus in group. |
147cbb4b | 2155 | */ |
95cdf3b7 | 2156 | static int |
758b2cdc | 2157 | find_idlest_cpu(struct sched_group *group, struct task_struct *p, int this_cpu) |
147cbb4b NP |
2158 | { |
2159 | unsigned long load, min_load = ULONG_MAX; | |
2160 | int idlest = -1; | |
2161 | int i; | |
2162 | ||
da5a5522 | 2163 | /* Traverse only the allowed CPUs */ |
758b2cdc | 2164 | for_each_cpu_and(i, sched_group_cpus(group), &p->cpus_allowed) { |
2dd73a4f | 2165 | load = weighted_cpuload(i); |
147cbb4b NP |
2166 | |
2167 | if (load < min_load || (load == min_load && i == this_cpu)) { | |
2168 | min_load = load; | |
2169 | idlest = i; | |
2170 | } | |
2171 | } | |
2172 | ||
2173 | return idlest; | |
2174 | } | |
2175 | ||
476d139c NP |
2176 | /* |
2177 | * sched_balance_self: balance the current task (running on cpu) in domains | |
2178 | * that have the 'flag' flag set. In practice, this is SD_BALANCE_FORK and | |
2179 | * SD_BALANCE_EXEC. | |
2180 | * | |
2181 | * Balance, ie. select the least loaded group. | |
2182 | * | |
2183 | * Returns the target CPU number, or the same CPU if no balancing is needed. | |
2184 | * | |
2185 | * preempt must be disabled. | |
2186 | */ | |
2187 | static int sched_balance_self(int cpu, int flag) | |
2188 | { | |
2189 | struct task_struct *t = current; | |
2190 | struct sched_domain *tmp, *sd = NULL; | |
147cbb4b | 2191 | |
c96d145e | 2192 | for_each_domain(cpu, tmp) { |
9761eea8 IM |
2193 | /* |
2194 | * If power savings logic is enabled for a domain, stop there. | |
2195 | */ | |
5c45bf27 SS |
2196 | if (tmp->flags & SD_POWERSAVINGS_BALANCE) |
2197 | break; | |
476d139c NP |
2198 | if (tmp->flags & flag) |
2199 | sd = tmp; | |
c96d145e | 2200 | } |
476d139c | 2201 | |
039a1c41 PZ |
2202 | if (sd) |
2203 | update_shares(sd); | |
2204 | ||
476d139c | 2205 | while (sd) { |
476d139c | 2206 | struct sched_group *group; |
1a848870 SS |
2207 | int new_cpu, weight; |
2208 | ||
2209 | if (!(sd->flags & flag)) { | |
2210 | sd = sd->child; | |
2211 | continue; | |
2212 | } | |
476d139c | 2213 | |
476d139c | 2214 | group = find_idlest_group(sd, t, cpu); |
1a848870 SS |
2215 | if (!group) { |
2216 | sd = sd->child; | |
2217 | continue; | |
2218 | } | |
476d139c | 2219 | |
758b2cdc | 2220 | new_cpu = find_idlest_cpu(group, t, cpu); |
1a848870 SS |
2221 | if (new_cpu == -1 || new_cpu == cpu) { |
2222 | /* Now try balancing at a lower domain level of cpu */ | |
2223 | sd = sd->child; | |
2224 | continue; | |
2225 | } | |
476d139c | 2226 | |
1a848870 | 2227 | /* Now try balancing at a lower domain level of new_cpu */ |
476d139c | 2228 | cpu = new_cpu; |
758b2cdc | 2229 | weight = cpumask_weight(sched_domain_span(sd)); |
476d139c | 2230 | sd = NULL; |
476d139c | 2231 | for_each_domain(cpu, tmp) { |
758b2cdc | 2232 | if (weight <= cpumask_weight(sched_domain_span(tmp))) |
476d139c NP |
2233 | break; |
2234 | if (tmp->flags & flag) | |
2235 | sd = tmp; | |
2236 | } | |
2237 | /* while loop will break here if sd == NULL */ | |
2238 | } | |
2239 | ||
2240 | return cpu; | |
2241 | } | |
2242 | ||
2243 | #endif /* CONFIG_SMP */ | |
1da177e4 | 2244 | |
1da177e4 LT |
2245 | /*** |
2246 | * try_to_wake_up - wake up a thread | |
2247 | * @p: the to-be-woken-up thread | |
2248 | * @state: the mask of task states that can be woken | |
2249 | * @sync: do a synchronous wakeup? | |
2250 | * | |
2251 | * Put it on the run-queue if it's not already there. The "current" | |
2252 | * thread is always on the run-queue (except when the actual | |
2253 | * re-schedule is in progress), and as such you're allowed to do | |
2254 | * the simpler "current->state = TASK_RUNNING" to mark yourself | |
2255 | * runnable without the overhead of this. | |
2256 | * | |
2257 | * returns failure only if the task is already active. | |
2258 | */ | |
36c8b586 | 2259 | static int try_to_wake_up(struct task_struct *p, unsigned int state, int sync) |
1da177e4 | 2260 | { |
cc367732 | 2261 | int cpu, orig_cpu, this_cpu, success = 0; |
1da177e4 LT |
2262 | unsigned long flags; |
2263 | long old_state; | |
70b97a7f | 2264 | struct rq *rq; |
1da177e4 | 2265 | |
b85d0667 IM |
2266 | if (!sched_feat(SYNC_WAKEUPS)) |
2267 | sync = 0; | |
2268 | ||
1596e297 PZ |
2269 | if (!sync) { |
2270 | if (current->se.avg_overlap < sysctl_sched_migration_cost && | |
2271 | p->se.avg_overlap < sysctl_sched_migration_cost) | |
2272 | sync = 1; | |
2273 | } else { | |
2274 | if (current->se.avg_overlap >= sysctl_sched_migration_cost || | |
2275 | p->se.avg_overlap >= sysctl_sched_migration_cost) | |
2276 | sync = 0; | |
2277 | } | |
d942fb6c | 2278 | |
2398f2c6 PZ |
2279 | #ifdef CONFIG_SMP |
2280 | if (sched_feat(LB_WAKEUP_UPDATE)) { | |
2281 | struct sched_domain *sd; | |
2282 | ||
2283 | this_cpu = raw_smp_processor_id(); | |
2284 | cpu = task_cpu(p); | |
2285 | ||
2286 | for_each_domain(this_cpu, sd) { | |
758b2cdc | 2287 | if (cpumask_test_cpu(cpu, sched_domain_span(sd))) { |
2398f2c6 PZ |
2288 | update_shares(sd); |
2289 | break; | |
2290 | } | |
2291 | } | |
2292 | } | |
2293 | #endif | |
2294 | ||
04e2f174 | 2295 | smp_wmb(); |
1da177e4 | 2296 | rq = task_rq_lock(p, &flags); |
03e89e45 | 2297 | update_rq_clock(rq); |
1da177e4 LT |
2298 | old_state = p->state; |
2299 | if (!(old_state & state)) | |
2300 | goto out; | |
2301 | ||
dd41f596 | 2302 | if (p->se.on_rq) |
1da177e4 LT |
2303 | goto out_running; |
2304 | ||
2305 | cpu = task_cpu(p); | |
cc367732 | 2306 | orig_cpu = cpu; |
1da177e4 LT |
2307 | this_cpu = smp_processor_id(); |
2308 | ||
2309 | #ifdef CONFIG_SMP | |
2310 | if (unlikely(task_running(rq, p))) | |
2311 | goto out_activate; | |
2312 | ||
5d2f5a61 DA |
2313 | cpu = p->sched_class->select_task_rq(p, sync); |
2314 | if (cpu != orig_cpu) { | |
2315 | set_task_cpu(p, cpu); | |
1da177e4 LT |
2316 | task_rq_unlock(rq, &flags); |
2317 | /* might preempt at this point */ | |
2318 | rq = task_rq_lock(p, &flags); | |
2319 | old_state = p->state; | |
2320 | if (!(old_state & state)) | |
2321 | goto out; | |
dd41f596 | 2322 | if (p->se.on_rq) |
1da177e4 LT |
2323 | goto out_running; |
2324 | ||
2325 | this_cpu = smp_processor_id(); | |
2326 | cpu = task_cpu(p); | |
2327 | } | |
2328 | ||
e7693a36 GH |
2329 | #ifdef CONFIG_SCHEDSTATS |
2330 | schedstat_inc(rq, ttwu_count); | |
2331 | if (cpu == this_cpu) | |
2332 | schedstat_inc(rq, ttwu_local); | |
2333 | else { | |
2334 | struct sched_domain *sd; | |
2335 | for_each_domain(this_cpu, sd) { | |
758b2cdc | 2336 | if (cpumask_test_cpu(cpu, sched_domain_span(sd))) { |
e7693a36 GH |
2337 | schedstat_inc(sd, ttwu_wake_remote); |
2338 | break; | |
2339 | } | |
2340 | } | |
2341 | } | |
6d6bc0ad | 2342 | #endif /* CONFIG_SCHEDSTATS */ |
e7693a36 | 2343 | |
1da177e4 LT |
2344 | out_activate: |
2345 | #endif /* CONFIG_SMP */ | |
cc367732 IM |
2346 | schedstat_inc(p, se.nr_wakeups); |
2347 | if (sync) | |
2348 | schedstat_inc(p, se.nr_wakeups_sync); | |
2349 | if (orig_cpu != cpu) | |
2350 | schedstat_inc(p, se.nr_wakeups_migrate); | |
2351 | if (cpu == this_cpu) | |
2352 | schedstat_inc(p, se.nr_wakeups_local); | |
2353 | else | |
2354 | schedstat_inc(p, se.nr_wakeups_remote); | |
dd41f596 | 2355 | activate_task(rq, p, 1); |
1da177e4 LT |
2356 | success = 1; |
2357 | ||
2358 | out_running: | |
468a15bb | 2359 | trace_sched_wakeup(rq, p, success); |
15afe09b | 2360 | check_preempt_curr(rq, p, sync); |
4ae7d5ce | 2361 | |
1da177e4 | 2362 | p->state = TASK_RUNNING; |
9a897c5a SR |
2363 | #ifdef CONFIG_SMP |
2364 | if (p->sched_class->task_wake_up) | |
2365 | p->sched_class->task_wake_up(rq, p); | |
2366 | #endif | |
1da177e4 | 2367 | out: |
2087a1ad GH |
2368 | current->se.last_wakeup = current->se.sum_exec_runtime; |
2369 | ||
1da177e4 LT |
2370 | task_rq_unlock(rq, &flags); |
2371 | ||
2372 | return success; | |
2373 | } | |
2374 | ||
7ad5b3a5 | 2375 | int wake_up_process(struct task_struct *p) |
1da177e4 | 2376 | { |
d9514f6c | 2377 | return try_to_wake_up(p, TASK_ALL, 0); |
1da177e4 | 2378 | } |
1da177e4 LT |
2379 | EXPORT_SYMBOL(wake_up_process); |
2380 | ||
7ad5b3a5 | 2381 | int wake_up_state(struct task_struct *p, unsigned int state) |
1da177e4 LT |
2382 | { |
2383 | return try_to_wake_up(p, state, 0); | |
2384 | } | |
2385 | ||
1da177e4 LT |
2386 | /* |
2387 | * Perform scheduler related setup for a newly forked process p. | |
2388 | * p is forked by current. | |
dd41f596 IM |
2389 | * |
2390 | * __sched_fork() is basic setup used by init_idle() too: | |
2391 | */ | |
2392 | static void __sched_fork(struct task_struct *p) | |
2393 | { | |
dd41f596 IM |
2394 | p->se.exec_start = 0; |
2395 | p->se.sum_exec_runtime = 0; | |
f6cf891c | 2396 | p->se.prev_sum_exec_runtime = 0; |
4ae7d5ce IM |
2397 | p->se.last_wakeup = 0; |
2398 | p->se.avg_overlap = 0; | |
6cfb0d5d IM |
2399 | |
2400 | #ifdef CONFIG_SCHEDSTATS | |
2401 | p->se.wait_start = 0; | |
dd41f596 IM |
2402 | p->se.sum_sleep_runtime = 0; |
2403 | p->se.sleep_start = 0; | |
dd41f596 IM |
2404 | p->se.block_start = 0; |
2405 | p->se.sleep_max = 0; | |
2406 | p->se.block_max = 0; | |
2407 | p->se.exec_max = 0; | |
eba1ed4b | 2408 | p->se.slice_max = 0; |
dd41f596 | 2409 | p->se.wait_max = 0; |
6cfb0d5d | 2410 | #endif |
476d139c | 2411 | |
fa717060 | 2412 | INIT_LIST_HEAD(&p->rt.run_list); |
dd41f596 | 2413 | p->se.on_rq = 0; |
4a55bd5e | 2414 | INIT_LIST_HEAD(&p->se.group_node); |
476d139c | 2415 | |
e107be36 AK |
2416 | #ifdef CONFIG_PREEMPT_NOTIFIERS |
2417 | INIT_HLIST_HEAD(&p->preempt_notifiers); | |
2418 | #endif | |
2419 | ||
1da177e4 LT |
2420 | /* |
2421 | * We mark the process as running here, but have not actually | |
2422 | * inserted it onto the runqueue yet. This guarantees that | |
2423 | * nobody will actually run it, and a signal or other external | |
2424 | * event cannot wake it up and insert it on the runqueue either. | |
2425 | */ | |
2426 | p->state = TASK_RUNNING; | |
dd41f596 IM |
2427 | } |
2428 | ||
2429 | /* | |
2430 | * fork()/clone()-time setup: | |
2431 | */ | |
2432 | void sched_fork(struct task_struct *p, int clone_flags) | |
2433 | { | |
2434 | int cpu = get_cpu(); | |
2435 | ||
2436 | __sched_fork(p); | |
2437 | ||
2438 | #ifdef CONFIG_SMP | |
2439 | cpu = sched_balance_self(cpu, SD_BALANCE_FORK); | |
2440 | #endif | |
02e4bac2 | 2441 | set_task_cpu(p, cpu); |
b29739f9 IM |
2442 | |
2443 | /* | |
2444 | * Make sure we do not leak PI boosting priority to the child: | |
2445 | */ | |
2446 | p->prio = current->normal_prio; | |
2ddbf952 HS |
2447 | if (!rt_prio(p->prio)) |
2448 | p->sched_class = &fair_sched_class; | |
b29739f9 | 2449 | |
52f17b6c | 2450 | #if defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT) |
dd41f596 | 2451 | if (likely(sched_info_on())) |
52f17b6c | 2452 | memset(&p->sched_info, 0, sizeof(p->sched_info)); |
1da177e4 | 2453 | #endif |
d6077cb8 | 2454 | #if defined(CONFIG_SMP) && defined(__ARCH_WANT_UNLOCKED_CTXSW) |
4866cde0 NP |
2455 | p->oncpu = 0; |
2456 | #endif | |
1da177e4 | 2457 | #ifdef CONFIG_PREEMPT |
4866cde0 | 2458 | /* Want to start with kernel preemption disabled. */ |
a1261f54 | 2459 | task_thread_info(p)->preempt_count = 1; |
1da177e4 | 2460 | #endif |
476d139c | 2461 | put_cpu(); |
1da177e4 LT |
2462 | } |
2463 | ||
2464 | /* | |
2465 | * wake_up_new_task - wake up a newly created task for the first time. | |
2466 | * | |
2467 | * This function will do some initial scheduler statistics housekeeping | |
2468 | * that must be done for every newly created context, then puts the task | |
2469 | * on the runqueue and wakes it. | |
2470 | */ | |
7ad5b3a5 | 2471 | void wake_up_new_task(struct task_struct *p, unsigned long clone_flags) |
1da177e4 LT |
2472 | { |
2473 | unsigned long flags; | |
dd41f596 | 2474 | struct rq *rq; |
1da177e4 LT |
2475 | |
2476 | rq = task_rq_lock(p, &flags); | |
147cbb4b | 2477 | BUG_ON(p->state != TASK_RUNNING); |
a8e504d2 | 2478 | update_rq_clock(rq); |
1da177e4 LT |
2479 | |
2480 | p->prio = effective_prio(p); | |
2481 | ||
b9dca1e0 | 2482 | if (!p->sched_class->task_new || !current->se.on_rq) { |
dd41f596 | 2483 | activate_task(rq, p, 0); |
1da177e4 | 2484 | } else { |
1da177e4 | 2485 | /* |
dd41f596 IM |
2486 | * Let the scheduling class do new task startup |
2487 | * management (if any): | |
1da177e4 | 2488 | */ |
ee0827d8 | 2489 | p->sched_class->task_new(rq, p); |
c09595f6 | 2490 | inc_nr_running(rq); |
1da177e4 | 2491 | } |
c71dd42d | 2492 | trace_sched_wakeup_new(rq, p, 1); |
15afe09b | 2493 | check_preempt_curr(rq, p, 0); |
9a897c5a SR |
2494 | #ifdef CONFIG_SMP |
2495 | if (p->sched_class->task_wake_up) | |
2496 | p->sched_class->task_wake_up(rq, p); | |
2497 | #endif | |
dd41f596 | 2498 | task_rq_unlock(rq, &flags); |
1da177e4 LT |
2499 | } |
2500 | ||
e107be36 AK |
2501 | #ifdef CONFIG_PREEMPT_NOTIFIERS |
2502 | ||
2503 | /** | |
421cee29 RD |
2504 | * preempt_notifier_register - tell me when current is being being preempted & rescheduled |
2505 | * @notifier: notifier struct to register | |
e107be36 AK |
2506 | */ |
2507 | void preempt_notifier_register(struct preempt_notifier *notifier) | |
2508 | { | |
2509 | hlist_add_head(¬ifier->link, ¤t->preempt_notifiers); | |
2510 | } | |
2511 | EXPORT_SYMBOL_GPL(preempt_notifier_register); | |
2512 | ||
2513 | /** | |
2514 | * preempt_notifier_unregister - no longer interested in preemption notifications | |
421cee29 | 2515 | * @notifier: notifier struct to unregister |
e107be36 AK |
2516 | * |
2517 | * This is safe to call from within a preemption notifier. | |
2518 | */ | |
2519 | void preempt_notifier_unregister(struct preempt_notifier *notifier) | |
2520 | { | |
2521 | hlist_del(¬ifier->link); | |
2522 | } | |
2523 | EXPORT_SYMBOL_GPL(preempt_notifier_unregister); | |
2524 | ||
2525 | static void fire_sched_in_preempt_notifiers(struct task_struct *curr) | |
2526 | { | |
2527 | struct preempt_notifier *notifier; | |
2528 | struct hlist_node *node; | |
2529 | ||
2530 | hlist_for_each_entry(notifier, node, &curr->preempt_notifiers, link) | |
2531 | notifier->ops->sched_in(notifier, raw_smp_processor_id()); | |
2532 | } | |
2533 | ||
2534 | static void | |
2535 | fire_sched_out_preempt_notifiers(struct task_struct *curr, | |
2536 | struct task_struct *next) | |
2537 | { | |
2538 | struct preempt_notifier *notifier; | |
2539 | struct hlist_node *node; | |
2540 | ||
2541 | hlist_for_each_entry(notifier, node, &curr->preempt_notifiers, link) | |
2542 | notifier->ops->sched_out(notifier, next); | |
2543 | } | |
2544 | ||
6d6bc0ad | 2545 | #else /* !CONFIG_PREEMPT_NOTIFIERS */ |
e107be36 AK |
2546 | |
2547 | static void fire_sched_in_preempt_notifiers(struct task_struct *curr) | |
2548 | { | |
2549 | } | |
2550 | ||
2551 | static void | |
2552 | fire_sched_out_preempt_notifiers(struct task_struct *curr, | |
2553 | struct task_struct *next) | |
2554 | { | |
2555 | } | |
2556 | ||
6d6bc0ad | 2557 | #endif /* CONFIG_PREEMPT_NOTIFIERS */ |
e107be36 | 2558 | |
4866cde0 NP |
2559 | /** |
2560 | * prepare_task_switch - prepare to switch tasks | |
2561 | * @rq: the runqueue preparing to switch | |
421cee29 | 2562 | * @prev: the current task that is being switched out |
4866cde0 NP |
2563 | * @next: the task we are going to switch to. |
2564 | * | |
2565 | * This is called with the rq lock held and interrupts off. It must | |
2566 | * be paired with a subsequent finish_task_switch after the context | |
2567 | * switch. | |
2568 | * | |
2569 | * prepare_task_switch sets up locking and calls architecture specific | |
2570 | * hooks. | |
2571 | */ | |
e107be36 AK |
2572 | static inline void |
2573 | prepare_task_switch(struct rq *rq, struct task_struct *prev, | |
2574 | struct task_struct *next) | |
4866cde0 | 2575 | { |
e107be36 | 2576 | fire_sched_out_preempt_notifiers(prev, next); |
4866cde0 NP |
2577 | prepare_lock_switch(rq, next); |
2578 | prepare_arch_switch(next); | |
2579 | } | |
2580 | ||
1da177e4 LT |
2581 | /** |
2582 | * finish_task_switch - clean up after a task-switch | |
344babaa | 2583 | * @rq: runqueue associated with task-switch |
1da177e4 LT |
2584 | * @prev: the thread we just switched away from. |
2585 | * | |
4866cde0 NP |
2586 | * finish_task_switch must be called after the context switch, paired |
2587 | * with a prepare_task_switch call before the context switch. | |
2588 | * finish_task_switch will reconcile locking set up by prepare_task_switch, | |
2589 | * and do any other architecture-specific cleanup actions. | |
1da177e4 LT |
2590 | * |
2591 | * Note that we may have delayed dropping an mm in context_switch(). If | |
41a2d6cf | 2592 | * so, we finish that here outside of the runqueue lock. (Doing it |
1da177e4 LT |
2593 | * with the lock held can cause deadlocks; see schedule() for |
2594 | * details.) | |
2595 | */ | |
a9957449 | 2596 | static void finish_task_switch(struct rq *rq, struct task_struct *prev) |
1da177e4 LT |
2597 | __releases(rq->lock) |
2598 | { | |
1da177e4 | 2599 | struct mm_struct *mm = rq->prev_mm; |
55a101f8 | 2600 | long prev_state; |
1da177e4 LT |
2601 | |
2602 | rq->prev_mm = NULL; | |
2603 | ||
2604 | /* | |
2605 | * A task struct has one reference for the use as "current". | |
c394cc9f | 2606 | * If a task dies, then it sets TASK_DEAD in tsk->state and calls |
55a101f8 ON |
2607 | * schedule one last time. The schedule call will never return, and |
2608 | * the scheduled task must drop that reference. | |
c394cc9f | 2609 | * The test for TASK_DEAD must occur while the runqueue locks are |
1da177e4 LT |
2610 | * still held, otherwise prev could be scheduled on another cpu, die |
2611 | * there before we look at prev->state, and then the reference would | |
2612 | * be dropped twice. | |
2613 | * Manfred Spraul <manfred@colorfullife.com> | |
2614 | */ | |
55a101f8 | 2615 | prev_state = prev->state; |
4866cde0 NP |
2616 | finish_arch_switch(prev); |
2617 | finish_lock_switch(rq, prev); | |
9a897c5a SR |
2618 | #ifdef CONFIG_SMP |
2619 | if (current->sched_class->post_schedule) | |
2620 | current->sched_class->post_schedule(rq); | |
2621 | #endif | |
e8fa1362 | 2622 | |
e107be36 | 2623 | fire_sched_in_preempt_notifiers(current); |
1da177e4 LT |
2624 | if (mm) |
2625 | mmdrop(mm); | |
c394cc9f | 2626 | if (unlikely(prev_state == TASK_DEAD)) { |
c6fd91f0 | 2627 | /* |
2628 | * Remove function-return probe instances associated with this | |
2629 | * task and put them back on the free list. | |
9761eea8 | 2630 | */ |
c6fd91f0 | 2631 | kprobe_flush_task(prev); |
1da177e4 | 2632 | put_task_struct(prev); |
c6fd91f0 | 2633 | } |
1da177e4 LT |
2634 | } |
2635 | ||
2636 | /** | |
2637 | * schedule_tail - first thing a freshly forked thread must call. | |
2638 | * @prev: the thread we just switched away from. | |
2639 | */ | |
36c8b586 | 2640 | asmlinkage void schedule_tail(struct task_struct *prev) |
1da177e4 LT |
2641 | __releases(rq->lock) |
2642 | { | |
70b97a7f IM |
2643 | struct rq *rq = this_rq(); |
2644 | ||
4866cde0 NP |
2645 | finish_task_switch(rq, prev); |
2646 | #ifdef __ARCH_WANT_UNLOCKED_CTXSW | |
2647 | /* In this case, finish_task_switch does not reenable preemption */ | |
2648 | preempt_enable(); | |
2649 | #endif | |
1da177e4 | 2650 | if (current->set_child_tid) |
b488893a | 2651 | put_user(task_pid_vnr(current), current->set_child_tid); |
1da177e4 LT |
2652 | } |
2653 | ||
2654 | /* | |
2655 | * context_switch - switch to the new MM and the new | |
2656 | * thread's register state. | |
2657 | */ | |
dd41f596 | 2658 | static inline void |
70b97a7f | 2659 | context_switch(struct rq *rq, struct task_struct *prev, |
36c8b586 | 2660 | struct task_struct *next) |
1da177e4 | 2661 | { |
dd41f596 | 2662 | struct mm_struct *mm, *oldmm; |
1da177e4 | 2663 | |
e107be36 | 2664 | prepare_task_switch(rq, prev, next); |
0a16b607 | 2665 | trace_sched_switch(rq, prev, next); |
dd41f596 IM |
2666 | mm = next->mm; |
2667 | oldmm = prev->active_mm; | |
9226d125 ZA |
2668 | /* |
2669 | * For paravirt, this is coupled with an exit in switch_to to | |
2670 | * combine the page table reload and the switch backend into | |
2671 | * one hypercall. | |
2672 | */ | |
2673 | arch_enter_lazy_cpu_mode(); | |
2674 | ||
dd41f596 | 2675 | if (unlikely(!mm)) { |
1da177e4 LT |
2676 | next->active_mm = oldmm; |
2677 | atomic_inc(&oldmm->mm_count); | |
2678 | enter_lazy_tlb(oldmm, next); | |
2679 | } else | |
2680 | switch_mm(oldmm, mm, next); | |
2681 | ||
dd41f596 | 2682 | if (unlikely(!prev->mm)) { |
1da177e4 | 2683 | prev->active_mm = NULL; |
1da177e4 LT |
2684 | rq->prev_mm = oldmm; |
2685 | } | |
3a5f5e48 IM |
2686 | /* |
2687 | * Since the runqueue lock will be released by the next | |
2688 | * task (which is an invalid locking op but in the case | |
2689 | * of the scheduler it's an obvious special-case), so we | |
2690 | * do an early lockdep release here: | |
2691 | */ | |
2692 | #ifndef __ARCH_WANT_UNLOCKED_CTXSW | |
8a25d5de | 2693 | spin_release(&rq->lock.dep_map, 1, _THIS_IP_); |
3a5f5e48 | 2694 | #endif |
1da177e4 LT |
2695 | |
2696 | /* Here we just switch the register state and the stack. */ | |
2697 | switch_to(prev, next, prev); | |
2698 | ||
dd41f596 IM |
2699 | barrier(); |
2700 | /* | |
2701 | * this_rq must be evaluated again because prev may have moved | |
2702 | * CPUs since it called schedule(), thus the 'rq' on its stack | |
2703 | * frame will be invalid. | |
2704 | */ | |
2705 | finish_task_switch(this_rq(), prev); | |
1da177e4 LT |
2706 | } |
2707 | ||
2708 | /* | |
2709 | * nr_running, nr_uninterruptible and nr_context_switches: | |
2710 | * | |
2711 | * externally visible scheduler statistics: current number of runnable | |
2712 | * threads, current number of uninterruptible-sleeping threads, total | |
2713 | * number of context switches performed since bootup. | |
2714 | */ | |
2715 | unsigned long nr_running(void) | |
2716 | { | |
2717 | unsigned long i, sum = 0; | |
2718 | ||
2719 | for_each_online_cpu(i) | |
2720 | sum += cpu_rq(i)->nr_running; | |
2721 | ||
2722 | return sum; | |
2723 | } | |
2724 | ||
2725 | unsigned long nr_uninterruptible(void) | |
2726 | { | |
2727 | unsigned long i, sum = 0; | |
2728 | ||
0a945022 | 2729 | for_each_possible_cpu(i) |
1da177e4 LT |
2730 | sum += cpu_rq(i)->nr_uninterruptible; |
2731 | ||
2732 | /* | |
2733 | * Since we read the counters lockless, it might be slightly | |
2734 | * inaccurate. Do not allow it to go below zero though: | |
2735 | */ | |
2736 | if (unlikely((long)sum < 0)) | |
2737 | sum = 0; | |
2738 | ||
2739 | return sum; | |
2740 | } | |
2741 | ||
2742 | unsigned long long nr_context_switches(void) | |
2743 | { | |
cc94abfc SR |
2744 | int i; |
2745 | unsigned long long sum = 0; | |
1da177e4 | 2746 | |
0a945022 | 2747 | for_each_possible_cpu(i) |
1da177e4 LT |
2748 | sum += cpu_rq(i)->nr_switches; |
2749 | ||
2750 | return sum; | |
2751 | } | |
2752 | ||
2753 | unsigned long nr_iowait(void) | |
2754 | { | |
2755 | unsigned long i, sum = 0; | |
2756 | ||
0a945022 | 2757 | for_each_possible_cpu(i) |
1da177e4 LT |
2758 | sum += atomic_read(&cpu_rq(i)->nr_iowait); |
2759 | ||
2760 | return sum; | |
2761 | } | |
2762 | ||
db1b1fef JS |
2763 | unsigned long nr_active(void) |
2764 | { | |
2765 | unsigned long i, running = 0, uninterruptible = 0; | |
2766 | ||
2767 | for_each_online_cpu(i) { | |
2768 | running += cpu_rq(i)->nr_running; | |
2769 | uninterruptible += cpu_rq(i)->nr_uninterruptible; | |
2770 | } | |
2771 | ||
2772 | if (unlikely((long)uninterruptible < 0)) | |
2773 | uninterruptible = 0; | |
2774 | ||
2775 | return running + uninterruptible; | |
2776 | } | |
2777 | ||
48f24c4d | 2778 | /* |
dd41f596 IM |
2779 | * Update rq->cpu_load[] statistics. This function is usually called every |
2780 | * scheduler tick (TICK_NSEC). | |
48f24c4d | 2781 | */ |
dd41f596 | 2782 | static void update_cpu_load(struct rq *this_rq) |
48f24c4d | 2783 | { |
495eca49 | 2784 | unsigned long this_load = this_rq->load.weight; |
dd41f596 IM |
2785 | int i, scale; |
2786 | ||
2787 | this_rq->nr_load_updates++; | |
dd41f596 IM |
2788 | |
2789 | /* Update our load: */ | |
2790 | for (i = 0, scale = 1; i < CPU_LOAD_IDX_MAX; i++, scale += scale) { | |
2791 | unsigned long old_load, new_load; | |
2792 | ||
2793 | /* scale is effectively 1 << i now, and >> i divides by scale */ | |
2794 | ||
2795 | old_load = this_rq->cpu_load[i]; | |
2796 | new_load = this_load; | |
a25707f3 IM |
2797 | /* |
2798 | * Round up the averaging division if load is increasing. This | |
2799 | * prevents us from getting stuck on 9 if the load is 10, for | |
2800 | * example. | |
2801 | */ | |
2802 | if (new_load > old_load) | |
2803 | new_load += scale-1; | |
dd41f596 IM |
2804 | this_rq->cpu_load[i] = (old_load*(scale-1) + new_load) >> i; |
2805 | } | |
48f24c4d IM |
2806 | } |
2807 | ||
dd41f596 IM |
2808 | #ifdef CONFIG_SMP |
2809 | ||
1da177e4 LT |
2810 | /* |
2811 | * double_rq_lock - safely lock two runqueues | |
2812 | * | |
2813 | * Note this does not disable interrupts like task_rq_lock, | |
2814 | * you need to do so manually before calling. | |
2815 | */ | |
70b97a7f | 2816 | static void double_rq_lock(struct rq *rq1, struct rq *rq2) |
1da177e4 LT |
2817 | __acquires(rq1->lock) |
2818 | __acquires(rq2->lock) | |
2819 | { | |
054b9108 | 2820 | BUG_ON(!irqs_disabled()); |
1da177e4 LT |
2821 | if (rq1 == rq2) { |
2822 | spin_lock(&rq1->lock); | |
2823 | __acquire(rq2->lock); /* Fake it out ;) */ | |
2824 | } else { | |
c96d145e | 2825 | if (rq1 < rq2) { |
1da177e4 | 2826 | spin_lock(&rq1->lock); |
5e710e37 | 2827 | spin_lock_nested(&rq2->lock, SINGLE_DEPTH_NESTING); |
1da177e4 LT |
2828 | } else { |
2829 | spin_lock(&rq2->lock); | |
5e710e37 | 2830 | spin_lock_nested(&rq1->lock, SINGLE_DEPTH_NESTING); |
1da177e4 LT |
2831 | } |
2832 | } | |
6e82a3be IM |
2833 | update_rq_clock(rq1); |
2834 | update_rq_clock(rq2); | |
1da177e4 LT |
2835 | } |
2836 | ||
2837 | /* | |
2838 | * double_rq_unlock - safely unlock two runqueues | |
2839 | * | |
2840 | * Note this does not restore interrupts like task_rq_unlock, | |
2841 | * you need to do so manually after calling. | |
2842 | */ | |
70b97a7f | 2843 | static void double_rq_unlock(struct rq *rq1, struct rq *rq2) |
1da177e4 LT |
2844 | __releases(rq1->lock) |
2845 | __releases(rq2->lock) | |
2846 | { | |
2847 | spin_unlock(&rq1->lock); | |
2848 | if (rq1 != rq2) | |
2849 | spin_unlock(&rq2->lock); | |
2850 | else | |
2851 | __release(rq2->lock); | |
2852 | } | |
2853 | ||
1da177e4 LT |
2854 | /* |
2855 | * If dest_cpu is allowed for this process, migrate the task to it. | |
2856 | * This is accomplished by forcing the cpu_allowed mask to only | |
41a2d6cf | 2857 | * allow dest_cpu, which will force the cpu onto dest_cpu. Then |
1da177e4 LT |
2858 | * the cpu_allowed mask is restored. |
2859 | */ | |
36c8b586 | 2860 | static void sched_migrate_task(struct task_struct *p, int dest_cpu) |
1da177e4 | 2861 | { |
70b97a7f | 2862 | struct migration_req req; |
1da177e4 | 2863 | unsigned long flags; |
70b97a7f | 2864 | struct rq *rq; |
1da177e4 LT |
2865 | |
2866 | rq = task_rq_lock(p, &flags); | |
96f874e2 | 2867 | if (!cpumask_test_cpu(dest_cpu, &p->cpus_allowed) |
e761b772 | 2868 | || unlikely(!cpu_active(dest_cpu))) |
1da177e4 LT |
2869 | goto out; |
2870 | ||
2871 | /* force the process onto the specified CPU */ | |
2872 | if (migrate_task(p, dest_cpu, &req)) { | |
2873 | /* Need to wait for migration thread (might exit: take ref). */ | |
2874 | struct task_struct *mt = rq->migration_thread; | |
36c8b586 | 2875 | |
1da177e4 LT |
2876 | get_task_struct(mt); |
2877 | task_rq_unlock(rq, &flags); | |
2878 | wake_up_process(mt); | |
2879 | put_task_struct(mt); | |
2880 | wait_for_completion(&req.done); | |
36c8b586 | 2881 | |
1da177e4 LT |
2882 | return; |
2883 | } | |
2884 | out: | |
2885 | task_rq_unlock(rq, &flags); | |
2886 | } | |
2887 | ||
2888 | /* | |
476d139c NP |
2889 | * sched_exec - execve() is a valuable balancing opportunity, because at |
2890 | * this point the task has the smallest effective memory and cache footprint. | |
1da177e4 LT |
2891 | */ |
2892 | void sched_exec(void) | |
2893 | { | |
1da177e4 | 2894 | int new_cpu, this_cpu = get_cpu(); |
476d139c | 2895 | new_cpu = sched_balance_self(this_cpu, SD_BALANCE_EXEC); |
1da177e4 | 2896 | put_cpu(); |
476d139c NP |
2897 | if (new_cpu != this_cpu) |
2898 | sched_migrate_task(current, new_cpu); | |
1da177e4 LT |
2899 | } |
2900 | ||
2901 | /* | |
2902 | * pull_task - move a task from a remote runqueue to the local runqueue. | |
2903 | * Both runqueues must be locked. | |
2904 | */ | |
dd41f596 IM |
2905 | static void pull_task(struct rq *src_rq, struct task_struct *p, |
2906 | struct rq *this_rq, int this_cpu) | |
1da177e4 | 2907 | { |
2e1cb74a | 2908 | deactivate_task(src_rq, p, 0); |
1da177e4 | 2909 | set_task_cpu(p, this_cpu); |
dd41f596 | 2910 | activate_task(this_rq, p, 0); |
1da177e4 LT |
2911 | /* |
2912 | * Note that idle threads have a prio of MAX_PRIO, for this test | |
2913 | * to be always true for them. | |
2914 | */ | |
15afe09b | 2915 | check_preempt_curr(this_rq, p, 0); |
1da177e4 LT |
2916 | } |
2917 | ||
2918 | /* | |
2919 | * can_migrate_task - may task p from runqueue rq be migrated to this_cpu? | |
2920 | */ | |
858119e1 | 2921 | static |
70b97a7f | 2922 | int can_migrate_task(struct task_struct *p, struct rq *rq, int this_cpu, |
d15bcfdb | 2923 | struct sched_domain *sd, enum cpu_idle_type idle, |
95cdf3b7 | 2924 | int *all_pinned) |
1da177e4 LT |
2925 | { |
2926 | /* | |
2927 | * We do not migrate tasks that are: | |
2928 | * 1) running (obviously), or | |
2929 | * 2) cannot be migrated to this CPU due to cpus_allowed, or | |
2930 | * 3) are cache-hot on their current CPU. | |
2931 | */ | |
96f874e2 | 2932 | if (!cpumask_test_cpu(this_cpu, &p->cpus_allowed)) { |
cc367732 | 2933 | schedstat_inc(p, se.nr_failed_migrations_affine); |
1da177e4 | 2934 | return 0; |
cc367732 | 2935 | } |
81026794 NP |
2936 | *all_pinned = 0; |
2937 | ||
cc367732 IM |
2938 | if (task_running(rq, p)) { |
2939 | schedstat_inc(p, se.nr_failed_migrations_running); | |
81026794 | 2940 | return 0; |
cc367732 | 2941 | } |
1da177e4 | 2942 | |
da84d961 IM |
2943 | /* |
2944 | * Aggressive migration if: | |
2945 | * 1) task is cache cold, or | |
2946 | * 2) too many balance attempts have failed. | |
2947 | */ | |
2948 | ||
6bc1665b IM |
2949 | if (!task_hot(p, rq->clock, sd) || |
2950 | sd->nr_balance_failed > sd->cache_nice_tries) { | |
da84d961 | 2951 | #ifdef CONFIG_SCHEDSTATS |
cc367732 | 2952 | if (task_hot(p, rq->clock, sd)) { |
da84d961 | 2953 | schedstat_inc(sd, lb_hot_gained[idle]); |
cc367732 IM |
2954 | schedstat_inc(p, se.nr_forced_migrations); |
2955 | } | |
da84d961 IM |
2956 | #endif |
2957 | return 1; | |
2958 | } | |
2959 | ||
cc367732 IM |
2960 | if (task_hot(p, rq->clock, sd)) { |
2961 | schedstat_inc(p, se.nr_failed_migrations_hot); | |
da84d961 | 2962 | return 0; |
cc367732 | 2963 | } |
1da177e4 LT |
2964 | return 1; |
2965 | } | |
2966 | ||
e1d1484f PW |
2967 | static unsigned long |
2968 | balance_tasks(struct rq *this_rq, int this_cpu, struct rq *busiest, | |
2969 | unsigned long max_load_move, struct sched_domain *sd, | |
2970 | enum cpu_idle_type idle, int *all_pinned, | |
2971 | int *this_best_prio, struct rq_iterator *iterator) | |
1da177e4 | 2972 | { |
051c6764 | 2973 | int loops = 0, pulled = 0, pinned = 0; |
dd41f596 IM |
2974 | struct task_struct *p; |
2975 | long rem_load_move = max_load_move; | |
1da177e4 | 2976 | |
e1d1484f | 2977 | if (max_load_move == 0) |
1da177e4 LT |
2978 | goto out; |
2979 | ||
81026794 NP |
2980 | pinned = 1; |
2981 | ||
1da177e4 | 2982 | /* |
dd41f596 | 2983 | * Start the load-balancing iterator: |
1da177e4 | 2984 | */ |
dd41f596 IM |
2985 | p = iterator->start(iterator->arg); |
2986 | next: | |
b82d9fdd | 2987 | if (!p || loops++ > sysctl_sched_nr_migrate) |
1da177e4 | 2988 | goto out; |
051c6764 PZ |
2989 | |
2990 | if ((p->se.load.weight >> 1) > rem_load_move || | |
dd41f596 | 2991 | !can_migrate_task(p, busiest, this_cpu, sd, idle, &pinned)) { |
dd41f596 IM |
2992 | p = iterator->next(iterator->arg); |
2993 | goto next; | |
1da177e4 LT |
2994 | } |
2995 | ||
dd41f596 | 2996 | pull_task(busiest, p, this_rq, this_cpu); |
1da177e4 | 2997 | pulled++; |
dd41f596 | 2998 | rem_load_move -= p->se.load.weight; |
1da177e4 | 2999 | |
2dd73a4f | 3000 | /* |
b82d9fdd | 3001 | * We only want to steal up to the prescribed amount of weighted load. |
2dd73a4f | 3002 | */ |
e1d1484f | 3003 | if (rem_load_move > 0) { |
a4ac01c3 PW |
3004 | if (p->prio < *this_best_prio) |
3005 | *this_best_prio = p->prio; | |
dd41f596 IM |
3006 | p = iterator->next(iterator->arg); |
3007 | goto next; | |
1da177e4 LT |
3008 | } |
3009 | out: | |
3010 | /* | |
e1d1484f | 3011 | * Right now, this is one of only two places pull_task() is called, |
1da177e4 LT |
3012 | * so we can safely collect pull_task() stats here rather than |
3013 | * inside pull_task(). | |
3014 | */ | |
3015 | schedstat_add(sd, lb_gained[idle], pulled); | |
81026794 NP |
3016 | |
3017 | if (all_pinned) | |
3018 | *all_pinned = pinned; | |
e1d1484f PW |
3019 | |
3020 | return max_load_move - rem_load_move; | |
1da177e4 LT |
3021 | } |
3022 | ||
dd41f596 | 3023 | /* |
43010659 PW |
3024 | * move_tasks tries to move up to max_load_move weighted load from busiest to |
3025 | * this_rq, as part of a balancing operation within domain "sd". | |
3026 | * Returns 1 if successful and 0 otherwise. | |
dd41f596 IM |
3027 | * |
3028 | * Called with both runqueues locked. | |
3029 | */ | |
3030 | static int move_tasks(struct rq *this_rq, int this_cpu, struct rq *busiest, | |
43010659 | 3031 | unsigned long max_load_move, |
dd41f596 IM |
3032 | struct sched_domain *sd, enum cpu_idle_type idle, |
3033 | int *all_pinned) | |
3034 | { | |
5522d5d5 | 3035 | const struct sched_class *class = sched_class_highest; |
43010659 | 3036 | unsigned long total_load_moved = 0; |
a4ac01c3 | 3037 | int this_best_prio = this_rq->curr->prio; |
dd41f596 IM |
3038 | |
3039 | do { | |
43010659 PW |
3040 | total_load_moved += |
3041 | class->load_balance(this_rq, this_cpu, busiest, | |
e1d1484f | 3042 | max_load_move - total_load_moved, |
a4ac01c3 | 3043 | sd, idle, all_pinned, &this_best_prio); |
dd41f596 | 3044 | class = class->next; |
c4acb2c0 GH |
3045 | |
3046 | if (idle == CPU_NEWLY_IDLE && this_rq->nr_running) | |
3047 | break; | |
3048 | ||
43010659 | 3049 | } while (class && max_load_move > total_load_moved); |
dd41f596 | 3050 | |
43010659 PW |
3051 | return total_load_moved > 0; |
3052 | } | |
3053 | ||
e1d1484f PW |
3054 | static int |
3055 | iter_move_one_task(struct rq *this_rq, int this_cpu, struct rq *busiest, | |
3056 | struct sched_domain *sd, enum cpu_idle_type idle, | |
3057 | struct rq_iterator *iterator) | |
3058 | { | |
3059 | struct task_struct *p = iterator->start(iterator->arg); | |
3060 | int pinned = 0; | |
3061 | ||
3062 | while (p) { | |
3063 | if (can_migrate_task(p, busiest, this_cpu, sd, idle, &pinned)) { | |
3064 | pull_task(busiest, p, this_rq, this_cpu); | |
3065 | /* | |
3066 | * Right now, this is only the second place pull_task() | |
3067 | * is called, so we can safely collect pull_task() | |
3068 | * stats here rather than inside pull_task(). | |
3069 | */ | |
3070 | schedstat_inc(sd, lb_gained[idle]); | |
3071 | ||
3072 | return 1; | |
3073 | } | |
3074 | p = iterator->next(iterator->arg); | |
3075 | } | |
3076 | ||
3077 | return 0; | |
3078 | } | |
3079 | ||
43010659 PW |
3080 | /* |
3081 | * move_one_task tries to move exactly one task from busiest to this_rq, as | |
3082 | * part of active balancing operations within "domain". | |
3083 | * Returns 1 if successful and 0 otherwise. | |
3084 | * | |
3085 | * Called with both runqueues locked. | |
3086 | */ | |
3087 | static int move_one_task(struct rq *this_rq, int this_cpu, struct rq *busiest, | |
3088 | struct sched_domain *sd, enum cpu_idle_type idle) | |
3089 | { | |
5522d5d5 | 3090 | const struct sched_class *class; |
43010659 PW |
3091 | |
3092 | for (class = sched_class_highest; class; class = class->next) | |
e1d1484f | 3093 | if (class->move_one_task(this_rq, this_cpu, busiest, sd, idle)) |
43010659 PW |
3094 | return 1; |
3095 | ||
3096 | return 0; | |
dd41f596 IM |
3097 | } |
3098 | ||
1da177e4 LT |
3099 | /* |
3100 | * find_busiest_group finds and returns the busiest CPU group within the | |
48f24c4d IM |
3101 | * domain. It calculates and returns the amount of weighted load which |
3102 | * should be moved to restore balance via the imbalance parameter. | |
1da177e4 LT |
3103 | */ |
3104 | static struct sched_group * | |
3105 | find_busiest_group(struct sched_domain *sd, int this_cpu, | |
dd41f596 | 3106 | unsigned long *imbalance, enum cpu_idle_type idle, |
96f874e2 | 3107 | int *sd_idle, const struct cpumask *cpus, int *balance) |
1da177e4 LT |
3108 | { |
3109 | struct sched_group *busiest = NULL, *this = NULL, *group = sd->groups; | |
3110 | unsigned long max_load, avg_load, total_load, this_load, total_pwr; | |
0c117f1b | 3111 | unsigned long max_pull; |
2dd73a4f PW |
3112 | unsigned long busiest_load_per_task, busiest_nr_running; |
3113 | unsigned long this_load_per_task, this_nr_running; | |
908a7c1b | 3114 | int load_idx, group_imb = 0; |
5c45bf27 SS |
3115 | #if defined(CONFIG_SCHED_MC) || defined(CONFIG_SCHED_SMT) |
3116 | int power_savings_balance = 1; | |
3117 | unsigned long leader_nr_running = 0, min_load_per_task = 0; | |
3118 | unsigned long min_nr_running = ULONG_MAX; | |
3119 | struct sched_group *group_min = NULL, *group_leader = NULL; | |
3120 | #endif | |
1da177e4 LT |
3121 | |
3122 | max_load = this_load = total_load = total_pwr = 0; | |
2dd73a4f PW |
3123 | busiest_load_per_task = busiest_nr_running = 0; |
3124 | this_load_per_task = this_nr_running = 0; | |
408ed066 | 3125 | |
d15bcfdb | 3126 | if (idle == CPU_NOT_IDLE) |
7897986b | 3127 | load_idx = sd->busy_idx; |
d15bcfdb | 3128 | else if (idle == CPU_NEWLY_IDLE) |
7897986b NP |
3129 | load_idx = sd->newidle_idx; |
3130 | else | |
3131 | load_idx = sd->idle_idx; | |
1da177e4 LT |
3132 | |
3133 | do { | |
908a7c1b | 3134 | unsigned long load, group_capacity, max_cpu_load, min_cpu_load; |
1da177e4 LT |
3135 | int local_group; |
3136 | int i; | |
908a7c1b | 3137 | int __group_imb = 0; |
783609c6 | 3138 | unsigned int balance_cpu = -1, first_idle_cpu = 0; |
2dd73a4f | 3139 | unsigned long sum_nr_running, sum_weighted_load; |
408ed066 PZ |
3140 | unsigned long sum_avg_load_per_task; |
3141 | unsigned long avg_load_per_task; | |
1da177e4 | 3142 | |
758b2cdc RR |
3143 | local_group = cpumask_test_cpu(this_cpu, |
3144 | sched_group_cpus(group)); | |
1da177e4 | 3145 | |
783609c6 | 3146 | if (local_group) |
758b2cdc | 3147 | balance_cpu = cpumask_first(sched_group_cpus(group)); |
783609c6 | 3148 | |
1da177e4 | 3149 | /* Tally up the load of all CPUs in the group */ |
2dd73a4f | 3150 | sum_weighted_load = sum_nr_running = avg_load = 0; |
408ed066 PZ |
3151 | sum_avg_load_per_task = avg_load_per_task = 0; |
3152 | ||
908a7c1b KC |
3153 | max_cpu_load = 0; |
3154 | min_cpu_load = ~0UL; | |
1da177e4 | 3155 | |
758b2cdc RR |
3156 | for_each_cpu_and(i, sched_group_cpus(group), cpus) { |
3157 | struct rq *rq = cpu_rq(i); | |
2dd73a4f | 3158 | |
9439aab8 | 3159 | if (*sd_idle && rq->nr_running) |
5969fe06 NP |
3160 | *sd_idle = 0; |
3161 | ||
1da177e4 | 3162 | /* Bias balancing toward cpus of our domain */ |
783609c6 SS |
3163 | if (local_group) { |
3164 | if (idle_cpu(i) && !first_idle_cpu) { | |
3165 | first_idle_cpu = 1; | |
3166 | balance_cpu = i; | |
3167 | } | |
3168 | ||
a2000572 | 3169 | load = target_load(i, load_idx); |
908a7c1b | 3170 | } else { |
a2000572 | 3171 | load = source_load(i, load_idx); |
908a7c1b KC |
3172 | if (load > max_cpu_load) |
3173 | max_cpu_load = load; | |
3174 | if (min_cpu_load > load) | |
3175 | min_cpu_load = load; | |
3176 | } | |
1da177e4 LT |
3177 | |
3178 | avg_load += load; | |
2dd73a4f | 3179 | sum_nr_running += rq->nr_running; |
dd41f596 | 3180 | sum_weighted_load += weighted_cpuload(i); |
408ed066 PZ |
3181 | |
3182 | sum_avg_load_per_task += cpu_avg_load_per_task(i); | |
1da177e4 LT |
3183 | } |
3184 | ||
783609c6 SS |
3185 | /* |
3186 | * First idle cpu or the first cpu(busiest) in this sched group | |
3187 | * is eligible for doing load balancing at this and above | |
9439aab8 SS |
3188 | * domains. In the newly idle case, we will allow all the cpu's |
3189 | * to do the newly idle load balance. | |
783609c6 | 3190 | */ |
9439aab8 SS |
3191 | if (idle != CPU_NEWLY_IDLE && local_group && |
3192 | balance_cpu != this_cpu && balance) { | |
783609c6 SS |
3193 | *balance = 0; |
3194 | goto ret; | |
3195 | } | |
3196 | ||
1da177e4 | 3197 | total_load += avg_load; |
5517d86b | 3198 | total_pwr += group->__cpu_power; |
1da177e4 LT |
3199 | |
3200 | /* Adjust by relative CPU power of the group */ | |
5517d86b ED |
3201 | avg_load = sg_div_cpu_power(group, |
3202 | avg_load * SCHED_LOAD_SCALE); | |
1da177e4 | 3203 | |
408ed066 PZ |
3204 | |
3205 | /* | |
3206 | * Consider the group unbalanced when the imbalance is larger | |
3207 | * than the average weight of two tasks. | |
3208 | * | |
3209 | * APZ: with cgroup the avg task weight can vary wildly and | |
3210 | * might not be a suitable number - should we keep a | |
3211 | * normalized nr_running number somewhere that negates | |
3212 | * the hierarchy? | |
3213 | */ | |
3214 | avg_load_per_task = sg_div_cpu_power(group, | |
3215 | sum_avg_load_per_task * SCHED_LOAD_SCALE); | |
3216 | ||
3217 | if ((max_cpu_load - min_cpu_load) > 2*avg_load_per_task) | |
908a7c1b KC |
3218 | __group_imb = 1; |
3219 | ||
5517d86b | 3220 | group_capacity = group->__cpu_power / SCHED_LOAD_SCALE; |
5c45bf27 | 3221 | |
1da177e4 LT |
3222 | if (local_group) { |
3223 | this_load = avg_load; | |
3224 | this = group; | |
2dd73a4f PW |
3225 | this_nr_running = sum_nr_running; |
3226 | this_load_per_task = sum_weighted_load; | |
3227 | } else if (avg_load > max_load && | |
908a7c1b | 3228 | (sum_nr_running > group_capacity || __group_imb)) { |
1da177e4 LT |
3229 | max_load = avg_load; |
3230 | busiest = group; | |
2dd73a4f PW |
3231 | busiest_nr_running = sum_nr_running; |
3232 | busiest_load_per_task = sum_weighted_load; | |
908a7c1b | 3233 | group_imb = __group_imb; |
1da177e4 | 3234 | } |
5c45bf27 SS |
3235 | |
3236 | #if defined(CONFIG_SCHED_MC) || defined(CONFIG_SCHED_SMT) | |
3237 | /* | |
3238 | * Busy processors will not participate in power savings | |
3239 | * balance. | |
3240 | */ | |
dd41f596 IM |
3241 | if (idle == CPU_NOT_IDLE || |
3242 | !(sd->flags & SD_POWERSAVINGS_BALANCE)) | |
3243 | goto group_next; | |
5c45bf27 SS |
3244 | |
3245 | /* | |
3246 | * If the local group is idle or completely loaded | |
3247 | * no need to do power savings balance at this domain | |
3248 | */ | |
3249 | if (local_group && (this_nr_running >= group_capacity || | |
3250 | !this_nr_running)) | |
3251 | power_savings_balance = 0; | |
3252 | ||
dd41f596 | 3253 | /* |
5c45bf27 SS |
3254 | * If a group is already running at full capacity or idle, |
3255 | * don't include that group in power savings calculations | |
dd41f596 IM |
3256 | */ |
3257 | if (!power_savings_balance || sum_nr_running >= group_capacity | |
5c45bf27 | 3258 | || !sum_nr_running) |
dd41f596 | 3259 | goto group_next; |
5c45bf27 | 3260 | |
dd41f596 | 3261 | /* |
5c45bf27 | 3262 | * Calculate the group which has the least non-idle load. |
dd41f596 IM |
3263 | * This is the group from where we need to pick up the load |
3264 | * for saving power | |
3265 | */ | |
3266 | if ((sum_nr_running < min_nr_running) || | |
3267 | (sum_nr_running == min_nr_running && | |
d5679bd1 | 3268 | cpumask_first(sched_group_cpus(group)) > |
758b2cdc | 3269 | cpumask_first(sched_group_cpus(group_min)))) { |
dd41f596 IM |
3270 | group_min = group; |
3271 | min_nr_running = sum_nr_running; | |
5c45bf27 SS |
3272 | min_load_per_task = sum_weighted_load / |
3273 | sum_nr_running; | |
dd41f596 | 3274 | } |
5c45bf27 | 3275 | |
dd41f596 | 3276 | /* |
5c45bf27 | 3277 | * Calculate the group which is almost near its |
dd41f596 IM |
3278 | * capacity but still has some space to pick up some load |
3279 | * from other group and save more power | |
3280 | */ | |
3281 | if (sum_nr_running <= group_capacity - 1) { | |
3282 | if (sum_nr_running > leader_nr_running || | |
3283 | (sum_nr_running == leader_nr_running && | |
d5679bd1 | 3284 | cpumask_first(sched_group_cpus(group)) < |
758b2cdc | 3285 | cpumask_first(sched_group_cpus(group_leader)))) { |
dd41f596 IM |
3286 | group_leader = group; |
3287 | leader_nr_running = sum_nr_running; | |
3288 | } | |
48f24c4d | 3289 | } |
5c45bf27 SS |
3290 | group_next: |
3291 | #endif | |
1da177e4 LT |
3292 | group = group->next; |
3293 | } while (group != sd->groups); | |
3294 | ||
2dd73a4f | 3295 | if (!busiest || this_load >= max_load || busiest_nr_running == 0) |
1da177e4 LT |
3296 | goto out_balanced; |
3297 | ||
3298 | avg_load = (SCHED_LOAD_SCALE * total_load) / total_pwr; | |
3299 | ||
3300 | if (this_load >= avg_load || | |
3301 | 100*max_load <= sd->imbalance_pct*this_load) | |
3302 | goto out_balanced; | |
3303 | ||
2dd73a4f | 3304 | busiest_load_per_task /= busiest_nr_running; |
908a7c1b KC |
3305 | if (group_imb) |
3306 | busiest_load_per_task = min(busiest_load_per_task, avg_load); | |
3307 | ||
1da177e4 LT |
3308 | /* |
3309 | * We're trying to get all the cpus to the average_load, so we don't | |
3310 | * want to push ourselves above the average load, nor do we wish to | |
3311 | * reduce the max loaded cpu below the average load, as either of these | |
3312 | * actions would just result in more rebalancing later, and ping-pong | |
3313 | * tasks around. Thus we look for the minimum possible imbalance. | |
3314 | * Negative imbalances (*we* are more loaded than anyone else) will | |
3315 | * be counted as no imbalance for these purposes -- we can't fix that | |
41a2d6cf | 3316 | * by pulling tasks to us. Be careful of negative numbers as they'll |
1da177e4 LT |
3317 | * appear as very large values with unsigned longs. |
3318 | */ | |
2dd73a4f PW |
3319 | if (max_load <= busiest_load_per_task) |
3320 | goto out_balanced; | |
3321 | ||
3322 | /* | |
3323 | * In the presence of smp nice balancing, certain scenarios can have | |
3324 | * max load less than avg load(as we skip the groups at or below | |
3325 | * its cpu_power, while calculating max_load..) | |
3326 | */ | |
3327 | if (max_load < avg_load) { | |
3328 | *imbalance = 0; | |
3329 | goto small_imbalance; | |
3330 | } | |
0c117f1b SS |
3331 | |
3332 | /* Don't want to pull so many tasks that a group would go idle */ | |
2dd73a4f | 3333 | max_pull = min(max_load - avg_load, max_load - busiest_load_per_task); |
0c117f1b | 3334 | |
1da177e4 | 3335 | /* How much load to actually move to equalise the imbalance */ |
5517d86b ED |
3336 | *imbalance = min(max_pull * busiest->__cpu_power, |
3337 | (avg_load - this_load) * this->__cpu_power) | |
1da177e4 LT |
3338 | / SCHED_LOAD_SCALE; |
3339 | ||
2dd73a4f PW |
3340 | /* |
3341 | * if *imbalance is less than the average load per runnable task | |
3342 | * there is no gaurantee that any tasks will be moved so we'll have | |
3343 | * a think about bumping its value to force at least one task to be | |
3344 | * moved | |
3345 | */ | |
7fd0d2dd | 3346 | if (*imbalance < busiest_load_per_task) { |
48f24c4d | 3347 | unsigned long tmp, pwr_now, pwr_move; |
2dd73a4f PW |
3348 | unsigned int imbn; |
3349 | ||
3350 | small_imbalance: | |
3351 | pwr_move = pwr_now = 0; | |
3352 | imbn = 2; | |
3353 | if (this_nr_running) { | |
3354 | this_load_per_task /= this_nr_running; | |
3355 | if (busiest_load_per_task > this_load_per_task) | |
3356 | imbn = 1; | |
3357 | } else | |
408ed066 | 3358 | this_load_per_task = cpu_avg_load_per_task(this_cpu); |
1da177e4 | 3359 | |
01c8c57d | 3360 | if (max_load - this_load + busiest_load_per_task >= |
dd41f596 | 3361 | busiest_load_per_task * imbn) { |
2dd73a4f | 3362 | *imbalance = busiest_load_per_task; |
1da177e4 LT |
3363 | return busiest; |
3364 | } | |
3365 | ||
3366 | /* | |
3367 | * OK, we don't have enough imbalance to justify moving tasks, | |
3368 | * however we may be able to increase total CPU power used by | |
3369 | * moving them. | |
3370 | */ | |
3371 | ||
5517d86b ED |
3372 | pwr_now += busiest->__cpu_power * |
3373 | min(busiest_load_per_task, max_load); | |
3374 | pwr_now += this->__cpu_power * | |
3375 | min(this_load_per_task, this_load); | |
1da177e4 LT |
3376 | pwr_now /= SCHED_LOAD_SCALE; |
3377 | ||
3378 | /* Amount of load we'd subtract */ | |
5517d86b ED |
3379 | tmp = sg_div_cpu_power(busiest, |
3380 | busiest_load_per_task * SCHED_LOAD_SCALE); | |
1da177e4 | 3381 | if (max_load > tmp) |
5517d86b | 3382 | pwr_move += busiest->__cpu_power * |
2dd73a4f | 3383 | min(busiest_load_per_task, max_load - tmp); |
1da177e4 LT |
3384 | |
3385 | /* Amount of load we'd add */ | |
5517d86b | 3386 | if (max_load * busiest->__cpu_power < |
33859f7f | 3387 | busiest_load_per_task * SCHED_LOAD_SCALE) |
5517d86b ED |
3388 | tmp = sg_div_cpu_power(this, |
3389 | max_load * busiest->__cpu_power); | |
1da177e4 | 3390 | else |
5517d86b ED |
3391 | tmp = sg_div_cpu_power(this, |
3392 | busiest_load_per_task * SCHED_LOAD_SCALE); | |
3393 | pwr_move += this->__cpu_power * | |
3394 | min(this_load_per_task, this_load + tmp); | |
1da177e4 LT |
3395 | pwr_move /= SCHED_LOAD_SCALE; |
3396 | ||
3397 | /* Move if we gain throughput */ | |
7fd0d2dd SS |
3398 | if (pwr_move > pwr_now) |
3399 | *imbalance = busiest_load_per_task; | |
1da177e4 LT |
3400 | } |
3401 | ||
1da177e4 LT |
3402 | return busiest; |
3403 | ||
3404 | out_balanced: | |
5c45bf27 | 3405 | #if defined(CONFIG_SCHED_MC) || defined(CONFIG_SCHED_SMT) |
d15bcfdb | 3406 | if (idle == CPU_NOT_IDLE || !(sd->flags & SD_POWERSAVINGS_BALANCE)) |
5c45bf27 | 3407 | goto ret; |
1da177e4 | 3408 | |
5c45bf27 SS |
3409 | if (this == group_leader && group_leader != group_min) { |
3410 | *imbalance = min_load_per_task; | |
7a09b1a2 VS |
3411 | if (sched_mc_power_savings >= POWERSAVINGS_BALANCE_WAKEUP) { |
3412 | cpu_rq(this_cpu)->rd->sched_mc_preferred_wakeup_cpu = | |
9924da43 | 3413 | cpumask_first(sched_group_cpus(group_leader)); |
7a09b1a2 | 3414 | } |
5c45bf27 SS |
3415 | return group_min; |
3416 | } | |
5c45bf27 | 3417 | #endif |
783609c6 | 3418 | ret: |
1da177e4 LT |
3419 | *imbalance = 0; |
3420 | return NULL; | |
3421 | } | |
3422 | ||
3423 | /* | |
3424 | * find_busiest_queue - find the busiest runqueue among the cpus in group. | |
3425 | */ | |
70b97a7f | 3426 | static struct rq * |
d15bcfdb | 3427 | find_busiest_queue(struct sched_group *group, enum cpu_idle_type idle, |
96f874e2 | 3428 | unsigned long imbalance, const struct cpumask *cpus) |
1da177e4 | 3429 | { |
70b97a7f | 3430 | struct rq *busiest = NULL, *rq; |
2dd73a4f | 3431 | unsigned long max_load = 0; |
1da177e4 LT |
3432 | int i; |
3433 | ||
758b2cdc | 3434 | for_each_cpu(i, sched_group_cpus(group)) { |
dd41f596 | 3435 | unsigned long wl; |
0a2966b4 | 3436 | |
96f874e2 | 3437 | if (!cpumask_test_cpu(i, cpus)) |
0a2966b4 CL |
3438 | continue; |
3439 | ||
48f24c4d | 3440 | rq = cpu_rq(i); |
dd41f596 | 3441 | wl = weighted_cpuload(i); |
2dd73a4f | 3442 | |
dd41f596 | 3443 | if (rq->nr_running == 1 && wl > imbalance) |
2dd73a4f | 3444 | continue; |
1da177e4 | 3445 | |
dd41f596 IM |
3446 | if (wl > max_load) { |
3447 | max_load = wl; | |
48f24c4d | 3448 | busiest = rq; |
1da177e4 LT |
3449 | } |
3450 | } | |
3451 | ||
3452 | return busiest; | |
3453 | } | |
3454 | ||
77391d71 NP |
3455 | /* |
3456 | * Max backoff if we encounter pinned tasks. Pretty arbitrary value, but | |
3457 | * so long as it is large enough. | |
3458 | */ | |
3459 | #define MAX_PINNED_INTERVAL 512 | |
3460 | ||
1da177e4 LT |
3461 | /* |
3462 | * Check this_cpu to ensure it is balanced within domain. Attempt to move | |
3463 | * tasks if there is an imbalance. | |
1da177e4 | 3464 | */ |
70b97a7f | 3465 | static int load_balance(int this_cpu, struct rq *this_rq, |
d15bcfdb | 3466 | struct sched_domain *sd, enum cpu_idle_type idle, |
96f874e2 | 3467 | int *balance, struct cpumask *cpus) |
1da177e4 | 3468 | { |
43010659 | 3469 | int ld_moved, all_pinned = 0, active_balance = 0, sd_idle = 0; |
1da177e4 | 3470 | struct sched_group *group; |
1da177e4 | 3471 | unsigned long imbalance; |
70b97a7f | 3472 | struct rq *busiest; |
fe2eea3f | 3473 | unsigned long flags; |
5969fe06 | 3474 | |
96f874e2 | 3475 | cpumask_setall(cpus); |
7c16ec58 | 3476 | |
89c4710e SS |
3477 | /* |
3478 | * When power savings policy is enabled for the parent domain, idle | |
3479 | * sibling can pick up load irrespective of busy siblings. In this case, | |
dd41f596 | 3480 | * let the state of idle sibling percolate up as CPU_IDLE, instead of |
d15bcfdb | 3481 | * portraying it as CPU_NOT_IDLE. |
89c4710e | 3482 | */ |
d15bcfdb | 3483 | if (idle != CPU_NOT_IDLE && sd->flags & SD_SHARE_CPUPOWER && |
89c4710e | 3484 | !test_sd_parent(sd, SD_POWERSAVINGS_BALANCE)) |
5969fe06 | 3485 | sd_idle = 1; |
1da177e4 | 3486 | |
2d72376b | 3487 | schedstat_inc(sd, lb_count[idle]); |
1da177e4 | 3488 | |
0a2966b4 | 3489 | redo: |
c8cba857 | 3490 | update_shares(sd); |
0a2966b4 | 3491 | group = find_busiest_group(sd, this_cpu, &imbalance, idle, &sd_idle, |
7c16ec58 | 3492 | cpus, balance); |
783609c6 | 3493 | |
06066714 | 3494 | if (*balance == 0) |
783609c6 | 3495 | goto out_balanced; |
783609c6 | 3496 | |
1da177e4 LT |
3497 | if (!group) { |
3498 | schedstat_inc(sd, lb_nobusyg[idle]); | |
3499 | goto out_balanced; | |
3500 | } | |
3501 | ||
7c16ec58 | 3502 | busiest = find_busiest_queue(group, idle, imbalance, cpus); |
1da177e4 LT |
3503 | if (!busiest) { |
3504 | schedstat_inc(sd, lb_nobusyq[idle]); | |
3505 | goto out_balanced; | |
3506 | } | |
3507 | ||
db935dbd | 3508 | BUG_ON(busiest == this_rq); |
1da177e4 LT |
3509 | |
3510 | schedstat_add(sd, lb_imbalance[idle], imbalance); | |
3511 | ||
43010659 | 3512 | ld_moved = 0; |
1da177e4 LT |
3513 | if (busiest->nr_running > 1) { |
3514 | /* | |
3515 | * Attempt to move tasks. If find_busiest_group has found | |
3516 | * an imbalance but busiest->nr_running <= 1, the group is | |
43010659 | 3517 | * still unbalanced. ld_moved simply stays zero, so it is |
1da177e4 LT |
3518 | * correctly treated as an imbalance. |
3519 | */ | |
fe2eea3f | 3520 | local_irq_save(flags); |
e17224bf | 3521 | double_rq_lock(this_rq, busiest); |
43010659 | 3522 | ld_moved = move_tasks(this_rq, this_cpu, busiest, |
48f24c4d | 3523 | imbalance, sd, idle, &all_pinned); |
e17224bf | 3524 | double_rq_unlock(this_rq, busiest); |
fe2eea3f | 3525 | local_irq_restore(flags); |
81026794 | 3526 | |
46cb4b7c SS |
3527 | /* |
3528 | * some other cpu did the load balance for us. | |
3529 | */ | |
43010659 | 3530 | if (ld_moved && this_cpu != smp_processor_id()) |
46cb4b7c SS |
3531 | resched_cpu(this_cpu); |
3532 | ||
81026794 | 3533 | /* All tasks on this runqueue were pinned by CPU affinity */ |
0a2966b4 | 3534 | if (unlikely(all_pinned)) { |
96f874e2 RR |
3535 | cpumask_clear_cpu(cpu_of(busiest), cpus); |
3536 | if (!cpumask_empty(cpus)) | |
0a2966b4 | 3537 | goto redo; |
81026794 | 3538 | goto out_balanced; |
0a2966b4 | 3539 | } |
1da177e4 | 3540 | } |
81026794 | 3541 | |
43010659 | 3542 | if (!ld_moved) { |
1da177e4 LT |
3543 | schedstat_inc(sd, lb_failed[idle]); |
3544 | sd->nr_balance_failed++; | |
3545 | ||
3546 | if (unlikely(sd->nr_balance_failed > sd->cache_nice_tries+2)) { | |
1da177e4 | 3547 | |
fe2eea3f | 3548 | spin_lock_irqsave(&busiest->lock, flags); |
fa3b6ddc SS |
3549 | |
3550 | /* don't kick the migration_thread, if the curr | |
3551 | * task on busiest cpu can't be moved to this_cpu | |
3552 | */ | |
96f874e2 RR |
3553 | if (!cpumask_test_cpu(this_cpu, |
3554 | &busiest->curr->cpus_allowed)) { | |
fe2eea3f | 3555 | spin_unlock_irqrestore(&busiest->lock, flags); |
fa3b6ddc SS |
3556 | all_pinned = 1; |
3557 | goto out_one_pinned; | |
3558 | } | |
3559 | ||
1da177e4 LT |
3560 | if (!busiest->active_balance) { |
3561 | busiest->active_balance = 1; | |
3562 | busiest->push_cpu = this_cpu; | |
81026794 | 3563 | active_balance = 1; |
1da177e4 | 3564 | } |
fe2eea3f | 3565 | spin_unlock_irqrestore(&busiest->lock, flags); |
81026794 | 3566 | if (active_balance) |
1da177e4 LT |
3567 | wake_up_process(busiest->migration_thread); |
3568 | ||
3569 | /* | |
3570 | * We've kicked active balancing, reset the failure | |
3571 | * counter. | |
3572 | */ | |
39507451 | 3573 | sd->nr_balance_failed = sd->cache_nice_tries+1; |
1da177e4 | 3574 | } |
81026794 | 3575 | } else |
1da177e4 LT |
3576 | sd->nr_balance_failed = 0; |
3577 | ||
81026794 | 3578 | if (likely(!active_balance)) { |
1da177e4 LT |
3579 | /* We were unbalanced, so reset the balancing interval */ |
3580 | sd->balance_interval = sd->min_interval; | |
81026794 NP |
3581 | } else { |
3582 | /* | |
3583 | * If we've begun active balancing, start to back off. This | |
3584 | * case may not be covered by the all_pinned logic if there | |
3585 | * is only 1 task on the busy runqueue (because we don't call | |
3586 | * move_tasks). | |
3587 | */ | |
3588 | if (sd->balance_interval < sd->max_interval) | |
3589 | sd->balance_interval *= 2; | |
1da177e4 LT |
3590 | } |
3591 | ||
43010659 | 3592 | if (!ld_moved && !sd_idle && sd->flags & SD_SHARE_CPUPOWER && |
89c4710e | 3593 | !test_sd_parent(sd, SD_POWERSAVINGS_BALANCE)) |
c09595f6 PZ |
3594 | ld_moved = -1; |
3595 | ||
3596 | goto out; | |
1da177e4 LT |
3597 | |
3598 | out_balanced: | |
1da177e4 LT |
3599 | schedstat_inc(sd, lb_balanced[idle]); |
3600 | ||
16cfb1c0 | 3601 | sd->nr_balance_failed = 0; |
fa3b6ddc SS |
3602 | |
3603 | out_one_pinned: | |
1da177e4 | 3604 | /* tune up the balancing interval */ |
77391d71 NP |
3605 | if ((all_pinned && sd->balance_interval < MAX_PINNED_INTERVAL) || |
3606 | (sd->balance_interval < sd->max_interval)) | |
1da177e4 LT |
3607 | sd->balance_interval *= 2; |
3608 | ||
48f24c4d | 3609 | if (!sd_idle && sd->flags & SD_SHARE_CPUPOWER && |
89c4710e | 3610 | !test_sd_parent(sd, SD_POWERSAVINGS_BALANCE)) |
c09595f6 PZ |
3611 | ld_moved = -1; |
3612 | else | |
3613 | ld_moved = 0; | |
3614 | out: | |
c8cba857 PZ |
3615 | if (ld_moved) |
3616 | update_shares(sd); | |
c09595f6 | 3617 | return ld_moved; |
1da177e4 LT |
3618 | } |
3619 | ||
3620 | /* | |
3621 | * Check this_cpu to ensure it is balanced within domain. Attempt to move | |
3622 | * tasks if there is an imbalance. | |
3623 | * | |
d15bcfdb | 3624 | * Called from schedule when this_rq is about to become idle (CPU_NEWLY_IDLE). |
1da177e4 LT |
3625 | * this_rq is locked. |
3626 | */ | |
48f24c4d | 3627 | static int |
7c16ec58 | 3628 | load_balance_newidle(int this_cpu, struct rq *this_rq, struct sched_domain *sd, |
96f874e2 | 3629 | struct cpumask *cpus) |
1da177e4 LT |
3630 | { |
3631 | struct sched_group *group; | |
70b97a7f | 3632 | struct rq *busiest = NULL; |
1da177e4 | 3633 | unsigned long imbalance; |
43010659 | 3634 | int ld_moved = 0; |
5969fe06 | 3635 | int sd_idle = 0; |
969bb4e4 | 3636 | int all_pinned = 0; |
7c16ec58 | 3637 | |
96f874e2 | 3638 | cpumask_setall(cpus); |
5969fe06 | 3639 | |
89c4710e SS |
3640 | /* |
3641 | * When power savings policy is enabled for the parent domain, idle | |
3642 | * sibling can pick up load irrespective of busy siblings. In this case, | |
3643 | * let the state of idle sibling percolate up as IDLE, instead of | |
d15bcfdb | 3644 | * portraying it as CPU_NOT_IDLE. |
89c4710e SS |
3645 | */ |
3646 | if (sd->flags & SD_SHARE_CPUPOWER && | |
3647 | !test_sd_parent(sd, SD_POWERSAVINGS_BALANCE)) | |
5969fe06 | 3648 | sd_idle = 1; |
1da177e4 | 3649 | |
2d72376b | 3650 | schedstat_inc(sd, lb_count[CPU_NEWLY_IDLE]); |
0a2966b4 | 3651 | redo: |
3e5459b4 | 3652 | update_shares_locked(this_rq, sd); |
d15bcfdb | 3653 | group = find_busiest_group(sd, this_cpu, &imbalance, CPU_NEWLY_IDLE, |
7c16ec58 | 3654 | &sd_idle, cpus, NULL); |
1da177e4 | 3655 | if (!group) { |
d15bcfdb | 3656 | schedstat_inc(sd, lb_nobusyg[CPU_NEWLY_IDLE]); |
16cfb1c0 | 3657 | goto out_balanced; |
1da177e4 LT |
3658 | } |
3659 | ||
7c16ec58 | 3660 | busiest = find_busiest_queue(group, CPU_NEWLY_IDLE, imbalance, cpus); |
db935dbd | 3661 | if (!busiest) { |
d15bcfdb | 3662 | schedstat_inc(sd, lb_nobusyq[CPU_NEWLY_IDLE]); |
16cfb1c0 | 3663 | goto out_balanced; |
1da177e4 LT |
3664 | } |
3665 | ||
db935dbd NP |
3666 | BUG_ON(busiest == this_rq); |
3667 | ||
d15bcfdb | 3668 | schedstat_add(sd, lb_imbalance[CPU_NEWLY_IDLE], imbalance); |
d6d5cfaf | 3669 | |
43010659 | 3670 | ld_moved = 0; |
d6d5cfaf NP |
3671 | if (busiest->nr_running > 1) { |
3672 | /* Attempt to move tasks */ | |
3673 | double_lock_balance(this_rq, busiest); | |
6e82a3be IM |
3674 | /* this_rq->clock is already updated */ |
3675 | update_rq_clock(busiest); | |
43010659 | 3676 | ld_moved = move_tasks(this_rq, this_cpu, busiest, |
969bb4e4 SS |
3677 | imbalance, sd, CPU_NEWLY_IDLE, |
3678 | &all_pinned); | |
1b12bbc7 | 3679 | double_unlock_balance(this_rq, busiest); |
0a2966b4 | 3680 | |
969bb4e4 | 3681 | if (unlikely(all_pinned)) { |
96f874e2 RR |
3682 | cpumask_clear_cpu(cpu_of(busiest), cpus); |
3683 | if (!cpumask_empty(cpus)) | |
0a2966b4 CL |
3684 | goto redo; |
3685 | } | |
d6d5cfaf NP |
3686 | } |
3687 | ||
43010659 | 3688 | if (!ld_moved) { |
36dffab6 | 3689 | int active_balance = 0; |
ad273b32 | 3690 | |
d15bcfdb | 3691 | schedstat_inc(sd, lb_failed[CPU_NEWLY_IDLE]); |
89c4710e SS |
3692 | if (!sd_idle && sd->flags & SD_SHARE_CPUPOWER && |
3693 | !test_sd_parent(sd, SD_POWERSAVINGS_BALANCE)) | |
5969fe06 | 3694 | return -1; |
ad273b32 VS |
3695 | |
3696 | if (sched_mc_power_savings < POWERSAVINGS_BALANCE_WAKEUP) | |
3697 | return -1; | |
3698 | ||
3699 | if (sd->nr_balance_failed++ < 2) | |
3700 | return -1; | |
3701 | ||
3702 | /* | |
3703 | * The only task running in a non-idle cpu can be moved to this | |
3704 | * cpu in an attempt to completely freeup the other CPU | |
3705 | * package. The same method used to move task in load_balance() | |
3706 | * have been extended for load_balance_newidle() to speedup | |
3707 | * consolidation at sched_mc=POWERSAVINGS_BALANCE_WAKEUP (2) | |
3708 | * | |
3709 | * The package power saving logic comes from | |
3710 | * find_busiest_group(). If there are no imbalance, then | |
3711 | * f_b_g() will return NULL. However when sched_mc={1,2} then | |
3712 | * f_b_g() will select a group from which a running task may be | |
3713 | * pulled to this cpu in order to make the other package idle. | |
3714 | * If there is no opportunity to make a package idle and if | |
3715 | * there are no imbalance, then f_b_g() will return NULL and no | |
3716 | * action will be taken in load_balance_newidle(). | |
3717 | * | |
3718 | * Under normal task pull operation due to imbalance, there | |
3719 | * will be more than one task in the source run queue and | |
3720 | * move_tasks() will succeed. ld_moved will be true and this | |
3721 | * active balance code will not be triggered. | |
3722 | */ | |
3723 | ||
3724 | /* Lock busiest in correct order while this_rq is held */ | |
3725 | double_lock_balance(this_rq, busiest); | |
3726 | ||
3727 | /* | |
3728 | * don't kick the migration_thread, if the curr | |
3729 | * task on busiest cpu can't be moved to this_cpu | |
3730 | */ | |
6ca09dfc | 3731 | if (!cpumask_test_cpu(this_cpu, &busiest->curr->cpus_allowed)) { |
ad273b32 VS |
3732 | double_unlock_balance(this_rq, busiest); |
3733 | all_pinned = 1; | |
3734 | return ld_moved; | |
3735 | } | |
3736 | ||
3737 | if (!busiest->active_balance) { | |
3738 | busiest->active_balance = 1; | |
3739 | busiest->push_cpu = this_cpu; | |
3740 | active_balance = 1; | |
3741 | } | |
3742 | ||
3743 | double_unlock_balance(this_rq, busiest); | |
da8d5089 PZ |
3744 | /* |
3745 | * Should not call ttwu while holding a rq->lock | |
3746 | */ | |
3747 | spin_unlock(&this_rq->lock); | |
ad273b32 VS |
3748 | if (active_balance) |
3749 | wake_up_process(busiest->migration_thread); | |
da8d5089 | 3750 | spin_lock(&this_rq->lock); |
ad273b32 | 3751 | |
5969fe06 | 3752 | } else |
16cfb1c0 | 3753 | sd->nr_balance_failed = 0; |
1da177e4 | 3754 | |
3e5459b4 | 3755 | update_shares_locked(this_rq, sd); |
43010659 | 3756 | return ld_moved; |
16cfb1c0 NP |
3757 | |
3758 | out_balanced: | |
d15bcfdb | 3759 | schedstat_inc(sd, lb_balanced[CPU_NEWLY_IDLE]); |
48f24c4d | 3760 | if (!sd_idle && sd->flags & SD_SHARE_CPUPOWER && |
89c4710e | 3761 | !test_sd_parent(sd, SD_POWERSAVINGS_BALANCE)) |
5969fe06 | 3762 | return -1; |
16cfb1c0 | 3763 | sd->nr_balance_failed = 0; |
48f24c4d | 3764 | |
16cfb1c0 | 3765 | return 0; |
1da177e4 LT |
3766 | } |
3767 | ||
3768 | /* | |
3769 | * idle_balance is called by schedule() if this_cpu is about to become | |
3770 | * idle. Attempts to pull tasks from other CPUs. | |
3771 | */ | |
70b97a7f | 3772 | static void idle_balance(int this_cpu, struct rq *this_rq) |
1da177e4 LT |
3773 | { |
3774 | struct sched_domain *sd; | |
efbe027e | 3775 | int pulled_task = 0; |
dd41f596 | 3776 | unsigned long next_balance = jiffies + HZ; |
4d2732c6 RR |
3777 | cpumask_var_t tmpmask; |
3778 | ||
3779 | if (!alloc_cpumask_var(&tmpmask, GFP_ATOMIC)) | |
3780 | return; | |
1da177e4 LT |
3781 | |
3782 | for_each_domain(this_cpu, sd) { | |
92c4ca5c CL |
3783 | unsigned long interval; |
3784 | ||
3785 | if (!(sd->flags & SD_LOAD_BALANCE)) | |
3786 | continue; | |
3787 | ||
3788 | if (sd->flags & SD_BALANCE_NEWIDLE) | |
48f24c4d | 3789 | /* If we've pulled tasks over stop searching: */ |
7c16ec58 | 3790 | pulled_task = load_balance_newidle(this_cpu, this_rq, |
4d2732c6 | 3791 | sd, tmpmask); |
92c4ca5c CL |
3792 | |
3793 | interval = msecs_to_jiffies(sd->balance_interval); | |
3794 | if (time_after(next_balance, sd->last_balance + interval)) | |
3795 | next_balance = sd->last_balance + interval; | |
3796 | if (pulled_task) | |
3797 | break; | |
1da177e4 | 3798 | } |
dd41f596 | 3799 | if (pulled_task || time_after(jiffies, this_rq->next_balance)) { |
1bd77f2d CL |
3800 | /* |
3801 | * We are going idle. next_balance may be set based on | |
3802 | * a busy processor. So reset next_balance. | |
3803 | */ | |
3804 | this_rq->next_balance = next_balance; | |
dd41f596 | 3805 | } |
4d2732c6 | 3806 | free_cpumask_var(tmpmask); |
1da177e4 LT |
3807 | } |
3808 | ||
3809 | /* | |
3810 | * active_load_balance is run by migration threads. It pushes running tasks | |
3811 | * off the busiest CPU onto idle CPUs. It requires at least 1 task to be | |
3812 | * running on each physical CPU where possible, and avoids physical / | |
3813 | * logical imbalances. | |
3814 | * | |
3815 | * Called with busiest_rq locked. | |
3816 | */ | |
70b97a7f | 3817 | static void active_load_balance(struct rq *busiest_rq, int busiest_cpu) |
1da177e4 | 3818 | { |
39507451 | 3819 | int target_cpu = busiest_rq->push_cpu; |
70b97a7f IM |
3820 | struct sched_domain *sd; |
3821 | struct rq *target_rq; | |
39507451 | 3822 | |
48f24c4d | 3823 | /* Is there any task to move? */ |
39507451 | 3824 | if (busiest_rq->nr_running <= 1) |
39507451 NP |
3825 | return; |
3826 | ||
3827 | target_rq = cpu_rq(target_cpu); | |
1da177e4 LT |
3828 | |
3829 | /* | |
39507451 | 3830 | * This condition is "impossible", if it occurs |
41a2d6cf | 3831 | * we need to fix it. Originally reported by |
39507451 | 3832 | * Bjorn Helgaas on a 128-cpu setup. |
1da177e4 | 3833 | */ |
39507451 | 3834 | BUG_ON(busiest_rq == target_rq); |
1da177e4 | 3835 | |
39507451 NP |
3836 | /* move a task from busiest_rq to target_rq */ |
3837 | double_lock_balance(busiest_rq, target_rq); | |
6e82a3be IM |
3838 | update_rq_clock(busiest_rq); |
3839 | update_rq_clock(target_rq); | |
39507451 NP |
3840 | |
3841 | /* Search for an sd spanning us and the target CPU. */ | |
c96d145e | 3842 | for_each_domain(target_cpu, sd) { |
39507451 | 3843 | if ((sd->flags & SD_LOAD_BALANCE) && |
758b2cdc | 3844 | cpumask_test_cpu(busiest_cpu, sched_domain_span(sd))) |
39507451 | 3845 | break; |
c96d145e | 3846 | } |
39507451 | 3847 | |
48f24c4d | 3848 | if (likely(sd)) { |
2d72376b | 3849 | schedstat_inc(sd, alb_count); |
39507451 | 3850 | |
43010659 PW |
3851 | if (move_one_task(target_rq, target_cpu, busiest_rq, |
3852 | sd, CPU_IDLE)) | |
48f24c4d IM |
3853 | schedstat_inc(sd, alb_pushed); |
3854 | else | |
3855 | schedstat_inc(sd, alb_failed); | |
3856 | } | |
1b12bbc7 | 3857 | double_unlock_balance(busiest_rq, target_rq); |
1da177e4 LT |
3858 | } |
3859 | ||
46cb4b7c SS |
3860 | #ifdef CONFIG_NO_HZ |
3861 | static struct { | |
3862 | atomic_t load_balancer; | |
7d1e6a9b | 3863 | cpumask_var_t cpu_mask; |
46cb4b7c SS |
3864 | } nohz ____cacheline_aligned = { |
3865 | .load_balancer = ATOMIC_INIT(-1), | |
46cb4b7c SS |
3866 | }; |
3867 | ||
7835b98b | 3868 | /* |
46cb4b7c SS |
3869 | * This routine will try to nominate the ilb (idle load balancing) |
3870 | * owner among the cpus whose ticks are stopped. ilb owner will do the idle | |
3871 | * load balancing on behalf of all those cpus. If all the cpus in the system | |
3872 | * go into this tickless mode, then there will be no ilb owner (as there is | |
3873 | * no need for one) and all the cpus will sleep till the next wakeup event | |
3874 | * arrives... | |
3875 | * | |
3876 | * For the ilb owner, tick is not stopped. And this tick will be used | |
3877 | * for idle load balancing. ilb owner will still be part of | |
3878 | * nohz.cpu_mask.. | |
7835b98b | 3879 | * |
46cb4b7c SS |
3880 | * While stopping the tick, this cpu will become the ilb owner if there |
3881 | * is no other owner. And will be the owner till that cpu becomes busy | |
3882 | * or if all cpus in the system stop their ticks at which point | |
3883 | * there is no need for ilb owner. | |
3884 | * | |
3885 | * When the ilb owner becomes busy, it nominates another owner, during the | |
3886 | * next busy scheduler_tick() | |
3887 | */ | |
3888 | int select_nohz_load_balancer(int stop_tick) | |
3889 | { | |
3890 | int cpu = smp_processor_id(); | |
3891 | ||
3892 | if (stop_tick) { | |
7d1e6a9b | 3893 | cpumask_set_cpu(cpu, nohz.cpu_mask); |
46cb4b7c SS |
3894 | cpu_rq(cpu)->in_nohz_recently = 1; |
3895 | ||
3896 | /* | |
3897 | * If we are going offline and still the leader, give up! | |
3898 | */ | |
e761b772 | 3899 | if (!cpu_active(cpu) && |
46cb4b7c SS |
3900 | atomic_read(&nohz.load_balancer) == cpu) { |
3901 | if (atomic_cmpxchg(&nohz.load_balancer, cpu, -1) != cpu) | |
3902 | BUG(); | |
3903 | return 0; | |
3904 | } | |
3905 | ||
3906 | /* time for ilb owner also to sleep */ | |
7d1e6a9b | 3907 | if (cpumask_weight(nohz.cpu_mask) == num_online_cpus()) { |
46cb4b7c SS |
3908 | if (atomic_read(&nohz.load_balancer) == cpu) |
3909 | atomic_set(&nohz.load_balancer, -1); | |
3910 | return 0; | |
3911 | } | |
3912 | ||
3913 | if (atomic_read(&nohz.load_balancer) == -1) { | |
3914 | /* make me the ilb owner */ | |
3915 | if (atomic_cmpxchg(&nohz.load_balancer, -1, cpu) == -1) | |
3916 | return 1; | |
3917 | } else if (atomic_read(&nohz.load_balancer) == cpu) | |
3918 | return 1; | |
3919 | } else { | |
7d1e6a9b | 3920 | if (!cpumask_test_cpu(cpu, nohz.cpu_mask)) |
46cb4b7c SS |
3921 | return 0; |
3922 | ||
7d1e6a9b | 3923 | cpumask_clear_cpu(cpu, nohz.cpu_mask); |
46cb4b7c SS |
3924 | |
3925 | if (atomic_read(&nohz.load_balancer) == cpu) | |
3926 | if (atomic_cmpxchg(&nohz.load_balancer, cpu, -1) != cpu) | |
3927 | BUG(); | |
3928 | } | |
3929 | return 0; | |
3930 | } | |
3931 | #endif | |
3932 | ||
3933 | static DEFINE_SPINLOCK(balancing); | |
3934 | ||
3935 | /* | |
7835b98b CL |
3936 | * It checks each scheduling domain to see if it is due to be balanced, |
3937 | * and initiates a balancing operation if so. | |
3938 | * | |
3939 | * Balancing parameters are set up in arch_init_sched_domains. | |
3940 | */ | |
a9957449 | 3941 | static void rebalance_domains(int cpu, enum cpu_idle_type idle) |
7835b98b | 3942 | { |
46cb4b7c SS |
3943 | int balance = 1; |
3944 | struct rq *rq = cpu_rq(cpu); | |
7835b98b CL |
3945 | unsigned long interval; |
3946 | struct sched_domain *sd; | |
46cb4b7c | 3947 | /* Earliest time when we have to do rebalance again */ |
c9819f45 | 3948 | unsigned long next_balance = jiffies + 60*HZ; |
f549da84 | 3949 | int update_next_balance = 0; |
d07355f5 | 3950 | int need_serialize; |
a0e90245 RR |
3951 | cpumask_var_t tmp; |
3952 | ||
3953 | /* Fails alloc? Rebalancing probably not a priority right now. */ | |
3954 | if (!alloc_cpumask_var(&tmp, GFP_ATOMIC)) | |
3955 | return; | |
1da177e4 | 3956 | |
46cb4b7c | 3957 | for_each_domain(cpu, sd) { |
1da177e4 LT |
3958 | if (!(sd->flags & SD_LOAD_BALANCE)) |
3959 | continue; | |
3960 | ||
3961 | interval = sd->balance_interval; | |
d15bcfdb | 3962 | if (idle != CPU_IDLE) |
1da177e4 LT |
3963 | interval *= sd->busy_factor; |
3964 | ||
3965 | /* scale ms to jiffies */ | |
3966 | interval = msecs_to_jiffies(interval); | |
3967 | if (unlikely(!interval)) | |
3968 | interval = 1; | |
dd41f596 IM |
3969 | if (interval > HZ*NR_CPUS/10) |
3970 | interval = HZ*NR_CPUS/10; | |
3971 | ||
d07355f5 | 3972 | need_serialize = sd->flags & SD_SERIALIZE; |
1da177e4 | 3973 | |
d07355f5 | 3974 | if (need_serialize) { |
08c183f3 CL |
3975 | if (!spin_trylock(&balancing)) |
3976 | goto out; | |
3977 | } | |
3978 | ||
c9819f45 | 3979 | if (time_after_eq(jiffies, sd->last_balance + interval)) { |
a0e90245 | 3980 | if (load_balance(cpu, rq, sd, idle, &balance, tmp)) { |
fa3b6ddc SS |
3981 | /* |
3982 | * We've pulled tasks over so either we're no | |
5969fe06 NP |
3983 | * longer idle, or one of our SMT siblings is |
3984 | * not idle. | |
3985 | */ | |
d15bcfdb | 3986 | idle = CPU_NOT_IDLE; |
1da177e4 | 3987 | } |
1bd77f2d | 3988 | sd->last_balance = jiffies; |
1da177e4 | 3989 | } |
d07355f5 | 3990 | if (need_serialize) |
08c183f3 CL |
3991 | spin_unlock(&balancing); |
3992 | out: | |
f549da84 | 3993 | if (time_after(next_balance, sd->last_balance + interval)) { |
c9819f45 | 3994 | next_balance = sd->last_balance + interval; |
f549da84 SS |
3995 | update_next_balance = 1; |
3996 | } | |
783609c6 SS |
3997 | |
3998 | /* | |
3999 | * Stop the load balance at this level. There is another | |
4000 | * CPU in our sched group which is doing load balancing more | |
4001 | * actively. | |
4002 | */ | |
4003 | if (!balance) | |
4004 | break; | |
1da177e4 | 4005 | } |
f549da84 SS |
4006 | |
4007 | /* | |
4008 | * next_balance will be updated only when there is a need. | |
4009 | * When the cpu is attached to null domain for ex, it will not be | |
4010 | * updated. | |
4011 | */ | |
4012 | if (likely(update_next_balance)) | |
4013 | rq->next_balance = next_balance; | |
a0e90245 RR |
4014 | |
4015 | free_cpumask_var(tmp); | |
46cb4b7c SS |
4016 | } |
4017 | ||
4018 | /* | |
4019 | * run_rebalance_domains is triggered when needed from the scheduler tick. | |
4020 | * In CONFIG_NO_HZ case, the idle load balance owner will do the | |
4021 | * rebalancing for all the cpus for whom scheduler ticks are stopped. | |
4022 | */ | |
4023 | static void run_rebalance_domains(struct softirq_action *h) | |
4024 | { | |
dd41f596 IM |
4025 | int this_cpu = smp_processor_id(); |
4026 | struct rq *this_rq = cpu_rq(this_cpu); | |
4027 | enum cpu_idle_type idle = this_rq->idle_at_tick ? | |
4028 | CPU_IDLE : CPU_NOT_IDLE; | |
46cb4b7c | 4029 | |
dd41f596 | 4030 | rebalance_domains(this_cpu, idle); |
46cb4b7c SS |
4031 | |
4032 | #ifdef CONFIG_NO_HZ | |
4033 | /* | |
4034 | * If this cpu is the owner for idle load balancing, then do the | |
4035 | * balancing on behalf of the other idle cpus whose ticks are | |
4036 | * stopped. | |
4037 | */ | |
dd41f596 IM |
4038 | if (this_rq->idle_at_tick && |
4039 | atomic_read(&nohz.load_balancer) == this_cpu) { | |
46cb4b7c SS |
4040 | struct rq *rq; |
4041 | int balance_cpu; | |
4042 | ||
7d1e6a9b RR |
4043 | for_each_cpu(balance_cpu, nohz.cpu_mask) { |
4044 | if (balance_cpu == this_cpu) | |
4045 | continue; | |
4046 | ||
46cb4b7c SS |
4047 | /* |
4048 | * If this cpu gets work to do, stop the load balancing | |
4049 | * work being done for other cpus. Next load | |
4050 | * balancing owner will pick it up. | |
4051 | */ | |
4052 | if (need_resched()) | |
4053 | break; | |
4054 | ||
de0cf899 | 4055 | rebalance_domains(balance_cpu, CPU_IDLE); |
46cb4b7c SS |
4056 | |
4057 | rq = cpu_rq(balance_cpu); | |
dd41f596 IM |
4058 | if (time_after(this_rq->next_balance, rq->next_balance)) |
4059 | this_rq->next_balance = rq->next_balance; | |
46cb4b7c SS |
4060 | } |
4061 | } | |
4062 | #endif | |
4063 | } | |
4064 | ||
4065 | /* | |
4066 | * Trigger the SCHED_SOFTIRQ if it is time to do periodic load balancing. | |
4067 | * | |
4068 | * In case of CONFIG_NO_HZ, this is the place where we nominate a new | |
4069 | * idle load balancing owner or decide to stop the periodic load balancing, | |
4070 | * if the whole system is idle. | |
4071 | */ | |
dd41f596 | 4072 | static inline void trigger_load_balance(struct rq *rq, int cpu) |
46cb4b7c | 4073 | { |
46cb4b7c SS |
4074 | #ifdef CONFIG_NO_HZ |
4075 | /* | |
4076 | * If we were in the nohz mode recently and busy at the current | |
4077 | * scheduler tick, then check if we need to nominate new idle | |
4078 | * load balancer. | |
4079 | */ | |
4080 | if (rq->in_nohz_recently && !rq->idle_at_tick) { | |
4081 | rq->in_nohz_recently = 0; | |
4082 | ||
4083 | if (atomic_read(&nohz.load_balancer) == cpu) { | |
7d1e6a9b | 4084 | cpumask_clear_cpu(cpu, nohz.cpu_mask); |
46cb4b7c SS |
4085 | atomic_set(&nohz.load_balancer, -1); |
4086 | } | |
4087 | ||
4088 | if (atomic_read(&nohz.load_balancer) == -1) { | |
4089 | /* | |
4090 | * simple selection for now: Nominate the | |
4091 | * first cpu in the nohz list to be the next | |
4092 | * ilb owner. | |
4093 | * | |
4094 | * TBD: Traverse the sched domains and nominate | |
4095 | * the nearest cpu in the nohz.cpu_mask. | |
4096 | */ | |
7d1e6a9b | 4097 | int ilb = cpumask_first(nohz.cpu_mask); |
46cb4b7c | 4098 | |
434d53b0 | 4099 | if (ilb < nr_cpu_ids) |
46cb4b7c SS |
4100 | resched_cpu(ilb); |
4101 | } | |
4102 | } | |
4103 | ||
4104 | /* | |
4105 | * If this cpu is idle and doing idle load balancing for all the | |
4106 | * cpus with ticks stopped, is it time for that to stop? | |
4107 | */ | |
4108 | if (rq->idle_at_tick && atomic_read(&nohz.load_balancer) == cpu && | |
7d1e6a9b | 4109 | cpumask_weight(nohz.cpu_mask) == num_online_cpus()) { |
46cb4b7c SS |
4110 | resched_cpu(cpu); |
4111 | return; | |
4112 | } | |
4113 | ||
4114 | /* | |
4115 | * If this cpu is idle and the idle load balancing is done by | |
4116 | * someone else, then no need raise the SCHED_SOFTIRQ | |
4117 | */ | |
4118 | if (rq->idle_at_tick && atomic_read(&nohz.load_balancer) != cpu && | |
7d1e6a9b | 4119 | cpumask_test_cpu(cpu, nohz.cpu_mask)) |
46cb4b7c SS |
4120 | return; |
4121 | #endif | |
4122 | if (time_after_eq(jiffies, rq->next_balance)) | |
4123 | raise_softirq(SCHED_SOFTIRQ); | |
1da177e4 | 4124 | } |
dd41f596 IM |
4125 | |
4126 | #else /* CONFIG_SMP */ | |
4127 | ||
1da177e4 LT |
4128 | /* |
4129 | * on UP we do not need to balance between CPUs: | |
4130 | */ | |
70b97a7f | 4131 | static inline void idle_balance(int cpu, struct rq *rq) |
1da177e4 LT |
4132 | { |
4133 | } | |
dd41f596 | 4134 | |
1da177e4 LT |
4135 | #endif |
4136 | ||
1da177e4 LT |
4137 | DEFINE_PER_CPU(struct kernel_stat, kstat); |
4138 | ||
4139 | EXPORT_PER_CPU_SYMBOL(kstat); | |
4140 | ||
4141 | /* | |
c5f8d995 | 4142 | * Return any ns on the sched_clock that have not yet been accounted in |
f06febc9 | 4143 | * @p in case that task is currently running. |
c5f8d995 HS |
4144 | * |
4145 | * Called with task_rq_lock() held on @rq. | |
1da177e4 | 4146 | */ |
c5f8d995 HS |
4147 | static u64 do_task_delta_exec(struct task_struct *p, struct rq *rq) |
4148 | { | |
4149 | u64 ns = 0; | |
4150 | ||
4151 | if (task_current(rq, p)) { | |
4152 | update_rq_clock(rq); | |
4153 | ns = rq->clock - p->se.exec_start; | |
4154 | if ((s64)ns < 0) | |
4155 | ns = 0; | |
4156 | } | |
4157 | ||
4158 | return ns; | |
4159 | } | |
4160 | ||
bb34d92f | 4161 | unsigned long long task_delta_exec(struct task_struct *p) |
1da177e4 | 4162 | { |
1da177e4 | 4163 | unsigned long flags; |
41b86e9c | 4164 | struct rq *rq; |
bb34d92f | 4165 | u64 ns = 0; |
48f24c4d | 4166 | |
41b86e9c | 4167 | rq = task_rq_lock(p, &flags); |
c5f8d995 HS |
4168 | ns = do_task_delta_exec(p, rq); |
4169 | task_rq_unlock(rq, &flags); | |
1508487e | 4170 | |
c5f8d995 HS |
4171 | return ns; |
4172 | } | |
f06febc9 | 4173 | |
c5f8d995 HS |
4174 | /* |
4175 | * Return accounted runtime for the task. | |
4176 | * In case the task is currently running, return the runtime plus current's | |
4177 | * pending runtime that have not been accounted yet. | |
4178 | */ | |
4179 | unsigned long long task_sched_runtime(struct task_struct *p) | |
4180 | { | |
4181 | unsigned long flags; | |
4182 | struct rq *rq; | |
4183 | u64 ns = 0; | |
4184 | ||
4185 | rq = task_rq_lock(p, &flags); | |
4186 | ns = p->se.sum_exec_runtime + do_task_delta_exec(p, rq); | |
4187 | task_rq_unlock(rq, &flags); | |
4188 | ||
4189 | return ns; | |
4190 | } | |
48f24c4d | 4191 | |
c5f8d995 HS |
4192 | /* |
4193 | * Return sum_exec_runtime for the thread group. | |
4194 | * In case the task is currently running, return the sum plus current's | |
4195 | * pending runtime that have not been accounted yet. | |
4196 | * | |
4197 | * Note that the thread group might have other running tasks as well, | |
4198 | * so the return value not includes other pending runtime that other | |
4199 | * running tasks might have. | |
4200 | */ | |
4201 | unsigned long long thread_group_sched_runtime(struct task_struct *p) | |
4202 | { | |
4203 | struct task_cputime totals; | |
4204 | unsigned long flags; | |
4205 | struct rq *rq; | |
4206 | u64 ns; | |
4207 | ||
4208 | rq = task_rq_lock(p, &flags); | |
4209 | thread_group_cputime(p, &totals); | |
4210 | ns = totals.sum_exec_runtime + do_task_delta_exec(p, rq); | |
41b86e9c | 4211 | task_rq_unlock(rq, &flags); |
48f24c4d | 4212 | |
1da177e4 LT |
4213 | return ns; |
4214 | } | |
4215 | ||
1da177e4 LT |
4216 | /* |
4217 | * Account user cpu time to a process. | |
4218 | * @p: the process that the cpu time gets accounted to | |
1da177e4 | 4219 | * @cputime: the cpu time spent in user space since the last update |
457533a7 | 4220 | * @cputime_scaled: cputime scaled by cpu frequency |
1da177e4 | 4221 | */ |
457533a7 MS |
4222 | void account_user_time(struct task_struct *p, cputime_t cputime, |
4223 | cputime_t cputime_scaled) | |
1da177e4 LT |
4224 | { |
4225 | struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat; | |
4226 | cputime64_t tmp; | |
4227 | ||
457533a7 | 4228 | /* Add user time to process. */ |
1da177e4 | 4229 | p->utime = cputime_add(p->utime, cputime); |
457533a7 | 4230 | p->utimescaled = cputime_add(p->utimescaled, cputime_scaled); |
f06febc9 | 4231 | account_group_user_time(p, cputime); |
1da177e4 LT |
4232 | |
4233 | /* Add user time to cpustat. */ | |
4234 | tmp = cputime_to_cputime64(cputime); | |
4235 | if (TASK_NICE(p) > 0) | |
4236 | cpustat->nice = cputime64_add(cpustat->nice, tmp); | |
4237 | else | |
4238 | cpustat->user = cputime64_add(cpustat->user, tmp); | |
49b5cf34 JL |
4239 | /* Account for user time used */ |
4240 | acct_update_integrals(p); | |
1da177e4 LT |
4241 | } |
4242 | ||
94886b84 LV |
4243 | /* |
4244 | * Account guest cpu time to a process. | |
4245 | * @p: the process that the cpu time gets accounted to | |
4246 | * @cputime: the cpu time spent in virtual machine since the last update | |
457533a7 | 4247 | * @cputime_scaled: cputime scaled by cpu frequency |
94886b84 | 4248 | */ |
457533a7 MS |
4249 | static void account_guest_time(struct task_struct *p, cputime_t cputime, |
4250 | cputime_t cputime_scaled) | |
94886b84 LV |
4251 | { |
4252 | cputime64_t tmp; | |
4253 | struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat; | |
4254 | ||
4255 | tmp = cputime_to_cputime64(cputime); | |
4256 | ||
457533a7 | 4257 | /* Add guest time to process. */ |
94886b84 | 4258 | p->utime = cputime_add(p->utime, cputime); |
457533a7 | 4259 | p->utimescaled = cputime_add(p->utimescaled, cputime_scaled); |
f06febc9 | 4260 | account_group_user_time(p, cputime); |
94886b84 LV |
4261 | p->gtime = cputime_add(p->gtime, cputime); |
4262 | ||
457533a7 | 4263 | /* Add guest time to cpustat. */ |
94886b84 LV |
4264 | cpustat->user = cputime64_add(cpustat->user, tmp); |
4265 | cpustat->guest = cputime64_add(cpustat->guest, tmp); | |
4266 | } | |
4267 | ||
1da177e4 LT |
4268 | /* |
4269 | * Account system cpu time to a process. | |
4270 | * @p: the process that the cpu time gets accounted to | |
4271 | * @hardirq_offset: the offset to subtract from hardirq_count() | |
4272 | * @cputime: the cpu time spent in kernel space since the last update | |
457533a7 | 4273 | * @cputime_scaled: cputime scaled by cpu frequency |
1da177e4 LT |
4274 | */ |
4275 | void account_system_time(struct task_struct *p, int hardirq_offset, | |
457533a7 | 4276 | cputime_t cputime, cputime_t cputime_scaled) |
1da177e4 LT |
4277 | { |
4278 | struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat; | |
1da177e4 LT |
4279 | cputime64_t tmp; |
4280 | ||
983ed7a6 | 4281 | if ((p->flags & PF_VCPU) && (irq_count() - hardirq_offset == 0)) { |
457533a7 | 4282 | account_guest_time(p, cputime, cputime_scaled); |
983ed7a6 HH |
4283 | return; |
4284 | } | |
94886b84 | 4285 | |
457533a7 | 4286 | /* Add system time to process. */ |
1da177e4 | 4287 | p->stime = cputime_add(p->stime, cputime); |
457533a7 | 4288 | p->stimescaled = cputime_add(p->stimescaled, cputime_scaled); |
f06febc9 | 4289 | account_group_system_time(p, cputime); |
1da177e4 LT |
4290 | |
4291 | /* Add system time to cpustat. */ | |
4292 | tmp = cputime_to_cputime64(cputime); | |
4293 | if (hardirq_count() - hardirq_offset) | |
4294 | cpustat->irq = cputime64_add(cpustat->irq, tmp); | |
4295 | else if (softirq_count()) | |
4296 | cpustat->softirq = cputime64_add(cpustat->softirq, tmp); | |
1da177e4 | 4297 | else |
79741dd3 MS |
4298 | cpustat->system = cputime64_add(cpustat->system, tmp); |
4299 | ||
1da177e4 LT |
4300 | /* Account for system time used */ |
4301 | acct_update_integrals(p); | |
1da177e4 LT |
4302 | } |
4303 | ||
c66f08be | 4304 | /* |
1da177e4 | 4305 | * Account for involuntary wait time. |
1da177e4 | 4306 | * @steal: the cpu time spent in involuntary wait |
c66f08be | 4307 | */ |
79741dd3 | 4308 | void account_steal_time(cputime_t cputime) |
c66f08be | 4309 | { |
79741dd3 MS |
4310 | struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat; |
4311 | cputime64_t cputime64 = cputime_to_cputime64(cputime); | |
4312 | ||
4313 | cpustat->steal = cputime64_add(cpustat->steal, cputime64); | |
c66f08be MN |
4314 | } |
4315 | ||
1da177e4 | 4316 | /* |
79741dd3 MS |
4317 | * Account for idle time. |
4318 | * @cputime: the cpu time spent in idle wait | |
1da177e4 | 4319 | */ |
79741dd3 | 4320 | void account_idle_time(cputime_t cputime) |
1da177e4 LT |
4321 | { |
4322 | struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat; | |
79741dd3 | 4323 | cputime64_t cputime64 = cputime_to_cputime64(cputime); |
70b97a7f | 4324 | struct rq *rq = this_rq(); |
1da177e4 | 4325 | |
79741dd3 MS |
4326 | if (atomic_read(&rq->nr_iowait) > 0) |
4327 | cpustat->iowait = cputime64_add(cpustat->iowait, cputime64); | |
4328 | else | |
4329 | cpustat->idle = cputime64_add(cpustat->idle, cputime64); | |
1da177e4 LT |
4330 | } |
4331 | ||
79741dd3 MS |
4332 | #ifndef CONFIG_VIRT_CPU_ACCOUNTING |
4333 | ||
4334 | /* | |
4335 | * Account a single tick of cpu time. | |
4336 | * @p: the process that the cpu time gets accounted to | |
4337 | * @user_tick: indicates if the tick is a user or a system tick | |
4338 | */ | |
4339 | void account_process_tick(struct task_struct *p, int user_tick) | |
4340 | { | |
4341 | cputime_t one_jiffy = jiffies_to_cputime(1); | |
4342 | cputime_t one_jiffy_scaled = cputime_to_scaled(one_jiffy); | |
4343 | struct rq *rq = this_rq(); | |
4344 | ||
4345 | if (user_tick) | |
4346 | account_user_time(p, one_jiffy, one_jiffy_scaled); | |
4347 | else if (p != rq->idle) | |
4348 | account_system_time(p, HARDIRQ_OFFSET, one_jiffy, | |
4349 | one_jiffy_scaled); | |
4350 | else | |
4351 | account_idle_time(one_jiffy); | |
4352 | } | |
4353 | ||
4354 | /* | |
4355 | * Account multiple ticks of steal time. | |
4356 | * @p: the process from which the cpu time has been stolen | |
4357 | * @ticks: number of stolen ticks | |
4358 | */ | |
4359 | void account_steal_ticks(unsigned long ticks) | |
4360 | { | |
4361 | account_steal_time(jiffies_to_cputime(ticks)); | |
4362 | } | |
4363 | ||
4364 | /* | |
4365 | * Account multiple ticks of idle time. | |
4366 | * @ticks: number of stolen ticks | |
4367 | */ | |
4368 | void account_idle_ticks(unsigned long ticks) | |
4369 | { | |
4370 | account_idle_time(jiffies_to_cputime(ticks)); | |
1da177e4 LT |
4371 | } |
4372 | ||
79741dd3 MS |
4373 | #endif |
4374 | ||
49048622 BS |
4375 | /* |
4376 | * Use precise platform statistics if available: | |
4377 | */ | |
4378 | #ifdef CONFIG_VIRT_CPU_ACCOUNTING | |
4379 | cputime_t task_utime(struct task_struct *p) | |
4380 | { | |
4381 | return p->utime; | |
4382 | } | |
4383 | ||
4384 | cputime_t task_stime(struct task_struct *p) | |
4385 | { | |
4386 | return p->stime; | |
4387 | } | |
4388 | #else | |
4389 | cputime_t task_utime(struct task_struct *p) | |
4390 | { | |
4391 | clock_t utime = cputime_to_clock_t(p->utime), | |
4392 | total = utime + cputime_to_clock_t(p->stime); | |
4393 | u64 temp; | |
4394 | ||
4395 | /* | |
4396 | * Use CFS's precise accounting: | |
4397 | */ | |
4398 | temp = (u64)nsec_to_clock_t(p->se.sum_exec_runtime); | |
4399 | ||
4400 | if (total) { | |
4401 | temp *= utime; | |
4402 | do_div(temp, total); | |
4403 | } | |
4404 | utime = (clock_t)temp; | |
4405 | ||
4406 | p->prev_utime = max(p->prev_utime, clock_t_to_cputime(utime)); | |
4407 | return p->prev_utime; | |
4408 | } | |
4409 | ||
4410 | cputime_t task_stime(struct task_struct *p) | |
4411 | { | |
4412 | clock_t stime; | |
4413 | ||
4414 | /* | |
4415 | * Use CFS's precise accounting. (we subtract utime from | |
4416 | * the total, to make sure the total observed by userspace | |
4417 | * grows monotonically - apps rely on that): | |
4418 | */ | |
4419 | stime = nsec_to_clock_t(p->se.sum_exec_runtime) - | |
4420 | cputime_to_clock_t(task_utime(p)); | |
4421 | ||
4422 | if (stime >= 0) | |
4423 | p->prev_stime = max(p->prev_stime, clock_t_to_cputime(stime)); | |
4424 | ||
4425 | return p->prev_stime; | |
4426 | } | |
4427 | #endif | |
4428 | ||
4429 | inline cputime_t task_gtime(struct task_struct *p) | |
4430 | { | |
4431 | return p->gtime; | |
4432 | } | |
4433 | ||
7835b98b CL |
4434 | /* |
4435 | * This function gets called by the timer code, with HZ frequency. | |
4436 | * We call it with interrupts disabled. | |
4437 | * | |
4438 | * It also gets called by the fork code, when changing the parent's | |
4439 | * timeslices. | |
4440 | */ | |
4441 | void scheduler_tick(void) | |
4442 | { | |
7835b98b CL |
4443 | int cpu = smp_processor_id(); |
4444 | struct rq *rq = cpu_rq(cpu); | |
dd41f596 | 4445 | struct task_struct *curr = rq->curr; |
3e51f33f PZ |
4446 | |
4447 | sched_clock_tick(); | |
dd41f596 IM |
4448 | |
4449 | spin_lock(&rq->lock); | |
3e51f33f | 4450 | update_rq_clock(rq); |
f1a438d8 | 4451 | update_cpu_load(rq); |
fa85ae24 | 4452 | curr->sched_class->task_tick(rq, curr, 0); |
dd41f596 | 4453 | spin_unlock(&rq->lock); |
7835b98b | 4454 | |
e418e1c2 | 4455 | #ifdef CONFIG_SMP |
dd41f596 IM |
4456 | rq->idle_at_tick = idle_cpu(cpu); |
4457 | trigger_load_balance(rq, cpu); | |
e418e1c2 | 4458 | #endif |
1da177e4 LT |
4459 | } |
4460 | ||
6cd8a4bb SR |
4461 | #if defined(CONFIG_PREEMPT) && (defined(CONFIG_DEBUG_PREEMPT) || \ |
4462 | defined(CONFIG_PREEMPT_TRACER)) | |
4463 | ||
4464 | static inline unsigned long get_parent_ip(unsigned long addr) | |
4465 | { | |
4466 | if (in_lock_functions(addr)) { | |
4467 | addr = CALLER_ADDR2; | |
4468 | if (in_lock_functions(addr)) | |
4469 | addr = CALLER_ADDR3; | |
4470 | } | |
4471 | return addr; | |
4472 | } | |
1da177e4 | 4473 | |
43627582 | 4474 | void __kprobes add_preempt_count(int val) |
1da177e4 | 4475 | { |
6cd8a4bb | 4476 | #ifdef CONFIG_DEBUG_PREEMPT |
1da177e4 LT |
4477 | /* |
4478 | * Underflow? | |
4479 | */ | |
9a11b49a IM |
4480 | if (DEBUG_LOCKS_WARN_ON((preempt_count() < 0))) |
4481 | return; | |
6cd8a4bb | 4482 | #endif |
1da177e4 | 4483 | preempt_count() += val; |
6cd8a4bb | 4484 | #ifdef CONFIG_DEBUG_PREEMPT |
1da177e4 LT |
4485 | /* |
4486 | * Spinlock count overflowing soon? | |
4487 | */ | |
33859f7f MOS |
4488 | DEBUG_LOCKS_WARN_ON((preempt_count() & PREEMPT_MASK) >= |
4489 | PREEMPT_MASK - 10); | |
6cd8a4bb SR |
4490 | #endif |
4491 | if (preempt_count() == val) | |
4492 | trace_preempt_off(CALLER_ADDR0, get_parent_ip(CALLER_ADDR1)); | |
1da177e4 LT |
4493 | } |
4494 | EXPORT_SYMBOL(add_preempt_count); | |
4495 | ||
43627582 | 4496 | void __kprobes sub_preempt_count(int val) |
1da177e4 | 4497 | { |
6cd8a4bb | 4498 | #ifdef CONFIG_DEBUG_PREEMPT |
1da177e4 LT |
4499 | /* |
4500 | * Underflow? | |
4501 | */ | |
01e3eb82 | 4502 | if (DEBUG_LOCKS_WARN_ON(val > preempt_count())) |
9a11b49a | 4503 | return; |
1da177e4 LT |
4504 | /* |
4505 | * Is the spinlock portion underflowing? | |
4506 | */ | |
9a11b49a IM |
4507 | if (DEBUG_LOCKS_WARN_ON((val < PREEMPT_MASK) && |
4508 | !(preempt_count() & PREEMPT_MASK))) | |
4509 | return; | |
6cd8a4bb | 4510 | #endif |
9a11b49a | 4511 | |
6cd8a4bb SR |
4512 | if (preempt_count() == val) |
4513 | trace_preempt_on(CALLER_ADDR0, get_parent_ip(CALLER_ADDR1)); | |
1da177e4 LT |
4514 | preempt_count() -= val; |
4515 | } | |
4516 | EXPORT_SYMBOL(sub_preempt_count); | |
4517 | ||
4518 | #endif | |
4519 | ||
4520 | /* | |
dd41f596 | 4521 | * Print scheduling while atomic bug: |
1da177e4 | 4522 | */ |
dd41f596 | 4523 | static noinline void __schedule_bug(struct task_struct *prev) |
1da177e4 | 4524 | { |
838225b4 SS |
4525 | struct pt_regs *regs = get_irq_regs(); |
4526 | ||
4527 | printk(KERN_ERR "BUG: scheduling while atomic: %s/%d/0x%08x\n", | |
4528 | prev->comm, prev->pid, preempt_count()); | |
4529 | ||
dd41f596 | 4530 | debug_show_held_locks(prev); |
e21f5b15 | 4531 | print_modules(); |
dd41f596 IM |
4532 | if (irqs_disabled()) |
4533 | print_irqtrace_events(prev); | |
838225b4 SS |
4534 | |
4535 | if (regs) | |
4536 | show_regs(regs); | |
4537 | else | |
4538 | dump_stack(); | |
dd41f596 | 4539 | } |
1da177e4 | 4540 | |
dd41f596 IM |
4541 | /* |
4542 | * Various schedule()-time debugging checks and statistics: | |
4543 | */ | |
4544 | static inline void schedule_debug(struct task_struct *prev) | |
4545 | { | |
1da177e4 | 4546 | /* |
41a2d6cf | 4547 | * Test if we are atomic. Since do_exit() needs to call into |
1da177e4 LT |
4548 | * schedule() atomically, we ignore that path for now. |
4549 | * Otherwise, whine if we are scheduling when we should not be. | |
4550 | */ | |
3f33a7ce | 4551 | if (unlikely(in_atomic_preempt_off() && !prev->exit_state)) |
dd41f596 IM |
4552 | __schedule_bug(prev); |
4553 | ||
1da177e4 LT |
4554 | profile_hit(SCHED_PROFILING, __builtin_return_address(0)); |
4555 | ||
2d72376b | 4556 | schedstat_inc(this_rq(), sched_count); |
b8efb561 IM |
4557 | #ifdef CONFIG_SCHEDSTATS |
4558 | if (unlikely(prev->lock_depth >= 0)) { | |
2d72376b IM |
4559 | schedstat_inc(this_rq(), bkl_count); |
4560 | schedstat_inc(prev, sched_info.bkl_count); | |
b8efb561 IM |
4561 | } |
4562 | #endif | |
dd41f596 IM |
4563 | } |
4564 | ||
4565 | /* | |
4566 | * Pick up the highest-prio task: | |
4567 | */ | |
4568 | static inline struct task_struct * | |
ff95f3df | 4569 | pick_next_task(struct rq *rq, struct task_struct *prev) |
dd41f596 | 4570 | { |
5522d5d5 | 4571 | const struct sched_class *class; |
dd41f596 | 4572 | struct task_struct *p; |
1da177e4 LT |
4573 | |
4574 | /* | |
dd41f596 IM |
4575 | * Optimization: we know that if all tasks are in |
4576 | * the fair class we can call that function directly: | |
1da177e4 | 4577 | */ |
dd41f596 | 4578 | if (likely(rq->nr_running == rq->cfs.nr_running)) { |
fb8d4724 | 4579 | p = fair_sched_class.pick_next_task(rq); |
dd41f596 IM |
4580 | if (likely(p)) |
4581 | return p; | |
1da177e4 LT |
4582 | } |
4583 | ||
dd41f596 IM |
4584 | class = sched_class_highest; |
4585 | for ( ; ; ) { | |
fb8d4724 | 4586 | p = class->pick_next_task(rq); |
dd41f596 IM |
4587 | if (p) |
4588 | return p; | |
4589 | /* | |
4590 | * Will never be NULL as the idle class always | |
4591 | * returns a non-NULL p: | |
4592 | */ | |
4593 | class = class->next; | |
4594 | } | |
4595 | } | |
1da177e4 | 4596 | |
dd41f596 IM |
4597 | /* |
4598 | * schedule() is the main scheduler function. | |
4599 | */ | |
41719b03 | 4600 | asmlinkage void __sched __schedule(void) |
dd41f596 IM |
4601 | { |
4602 | struct task_struct *prev, *next; | |
67ca7bde | 4603 | unsigned long *switch_count; |
dd41f596 | 4604 | struct rq *rq; |
31656519 | 4605 | int cpu; |
dd41f596 | 4606 | |
dd41f596 IM |
4607 | cpu = smp_processor_id(); |
4608 | rq = cpu_rq(cpu); | |
4609 | rcu_qsctr_inc(cpu); | |
4610 | prev = rq->curr; | |
4611 | switch_count = &prev->nivcsw; | |
4612 | ||
4613 | release_kernel_lock(prev); | |
4614 | need_resched_nonpreemptible: | |
4615 | ||
4616 | schedule_debug(prev); | |
1da177e4 | 4617 | |
31656519 | 4618 | if (sched_feat(HRTICK)) |
f333fdc9 | 4619 | hrtick_clear(rq); |
8f4d37ec | 4620 | |
8cd162ce | 4621 | spin_lock_irq(&rq->lock); |
3e51f33f | 4622 | update_rq_clock(rq); |
1e819950 | 4623 | clear_tsk_need_resched(prev); |
1da177e4 | 4624 | |
1da177e4 | 4625 | if (prev->state && !(preempt_count() & PREEMPT_ACTIVE)) { |
16882c1e | 4626 | if (unlikely(signal_pending_state(prev->state, prev))) |
1da177e4 | 4627 | prev->state = TASK_RUNNING; |
16882c1e | 4628 | else |
2e1cb74a | 4629 | deactivate_task(rq, prev, 1); |
dd41f596 | 4630 | switch_count = &prev->nvcsw; |
1da177e4 LT |
4631 | } |
4632 | ||
9a897c5a SR |
4633 | #ifdef CONFIG_SMP |
4634 | if (prev->sched_class->pre_schedule) | |
4635 | prev->sched_class->pre_schedule(rq, prev); | |
4636 | #endif | |
f65eda4f | 4637 | |
dd41f596 | 4638 | if (unlikely(!rq->nr_running)) |
1da177e4 | 4639 | idle_balance(cpu, rq); |
1da177e4 | 4640 | |
31ee529c | 4641 | prev->sched_class->put_prev_task(rq, prev); |
ff95f3df | 4642 | next = pick_next_task(rq, prev); |
1da177e4 | 4643 | |
1da177e4 | 4644 | if (likely(prev != next)) { |
673a90a1 DS |
4645 | sched_info_switch(prev, next); |
4646 | ||
1da177e4 LT |
4647 | rq->nr_switches++; |
4648 | rq->curr = next; | |
4649 | ++*switch_count; | |
4650 | ||
dd41f596 | 4651 | context_switch(rq, prev, next); /* unlocks the rq */ |
8f4d37ec PZ |
4652 | /* |
4653 | * the context switch might have flipped the stack from under | |
4654 | * us, hence refresh the local variables. | |
4655 | */ | |
4656 | cpu = smp_processor_id(); | |
4657 | rq = cpu_rq(cpu); | |
1da177e4 LT |
4658 | } else |
4659 | spin_unlock_irq(&rq->lock); | |
4660 | ||
8f4d37ec | 4661 | if (unlikely(reacquire_kernel_lock(current) < 0)) |
1da177e4 | 4662 | goto need_resched_nonpreemptible; |
41719b03 | 4663 | } |
8f4d37ec | 4664 | |
41719b03 PZ |
4665 | asmlinkage void __sched schedule(void) |
4666 | { | |
4667 | need_resched: | |
4668 | preempt_disable(); | |
4669 | __schedule(); | |
1da177e4 LT |
4670 | preempt_enable_no_resched(); |
4671 | if (unlikely(test_thread_flag(TIF_NEED_RESCHED))) | |
4672 | goto need_resched; | |
4673 | } | |
1da177e4 LT |
4674 | EXPORT_SYMBOL(schedule); |
4675 | ||
0d66bf6d PZ |
4676 | #ifdef CONFIG_SMP |
4677 | /* | |
4678 | * Look out! "owner" is an entirely speculative pointer | |
4679 | * access and not reliable. | |
4680 | */ | |
4681 | int mutex_spin_on_owner(struct mutex *lock, struct thread_info *owner) | |
4682 | { | |
4683 | unsigned int cpu; | |
4684 | struct rq *rq; | |
4685 | ||
4686 | if (!sched_feat(OWNER_SPIN)) | |
4687 | return 0; | |
4688 | ||
4689 | #ifdef CONFIG_DEBUG_PAGEALLOC | |
4690 | /* | |
4691 | * Need to access the cpu field knowing that | |
4692 | * DEBUG_PAGEALLOC could have unmapped it if | |
4693 | * the mutex owner just released it and exited. | |
4694 | */ | |
4695 | if (probe_kernel_address(&owner->cpu, cpu)) | |
4696 | goto out; | |
4697 | #else | |
4698 | cpu = owner->cpu; | |
4699 | #endif | |
4700 | ||
4701 | /* | |
4702 | * Even if the access succeeded (likely case), | |
4703 | * the cpu field may no longer be valid. | |
4704 | */ | |
4705 | if (cpu >= nr_cpumask_bits) | |
4706 | goto out; | |
4707 | ||
4708 | /* | |
4709 | * We need to validate that we can do a | |
4710 | * get_cpu() and that we have the percpu area. | |
4711 | */ | |
4712 | if (!cpu_online(cpu)) | |
4713 | goto out; | |
4714 | ||
4715 | rq = cpu_rq(cpu); | |
4716 | ||
4717 | for (;;) { | |
4718 | /* | |
4719 | * Owner changed, break to re-assess state. | |
4720 | */ | |
4721 | if (lock->owner != owner) | |
4722 | break; | |
4723 | ||
4724 | /* | |
4725 | * Is that owner really running on that cpu? | |
4726 | */ | |
4727 | if (task_thread_info(rq->curr) != owner || need_resched()) | |
4728 | return 0; | |
4729 | ||
4730 | cpu_relax(); | |
4731 | } | |
4732 | out: | |
4733 | return 1; | |
4734 | } | |
4735 | #endif | |
4736 | ||
1da177e4 LT |
4737 | #ifdef CONFIG_PREEMPT |
4738 | /* | |
2ed6e34f | 4739 | * this is the entry point to schedule() from in-kernel preemption |
41a2d6cf | 4740 | * off of preempt_enable. Kernel preemptions off return from interrupt |
1da177e4 LT |
4741 | * occur there and call schedule directly. |
4742 | */ | |
4743 | asmlinkage void __sched preempt_schedule(void) | |
4744 | { | |
4745 | struct thread_info *ti = current_thread_info(); | |
6478d880 | 4746 | |
1da177e4 LT |
4747 | /* |
4748 | * If there is a non-zero preempt_count or interrupts are disabled, | |
41a2d6cf | 4749 | * we do not want to preempt the current task. Just return.. |
1da177e4 | 4750 | */ |
beed33a8 | 4751 | if (likely(ti->preempt_count || irqs_disabled())) |
1da177e4 LT |
4752 | return; |
4753 | ||
3a5c359a AK |
4754 | do { |
4755 | add_preempt_count(PREEMPT_ACTIVE); | |
3a5c359a | 4756 | schedule(); |
3a5c359a | 4757 | sub_preempt_count(PREEMPT_ACTIVE); |
1da177e4 | 4758 | |
3a5c359a AK |
4759 | /* |
4760 | * Check again in case we missed a preemption opportunity | |
4761 | * between schedule and now. | |
4762 | */ | |
4763 | barrier(); | |
4764 | } while (unlikely(test_thread_flag(TIF_NEED_RESCHED))); | |
1da177e4 | 4765 | } |
1da177e4 LT |
4766 | EXPORT_SYMBOL(preempt_schedule); |
4767 | ||
4768 | /* | |
2ed6e34f | 4769 | * this is the entry point to schedule() from kernel preemption |
1da177e4 LT |
4770 | * off of irq context. |
4771 | * Note, that this is called and return with irqs disabled. This will | |
4772 | * protect us against recursive calling from irq. | |
4773 | */ | |
4774 | asmlinkage void __sched preempt_schedule_irq(void) | |
4775 | { | |
4776 | struct thread_info *ti = current_thread_info(); | |
6478d880 | 4777 | |
2ed6e34f | 4778 | /* Catch callers which need to be fixed */ |
1da177e4 LT |
4779 | BUG_ON(ti->preempt_count || !irqs_disabled()); |
4780 | ||
3a5c359a AK |
4781 | do { |
4782 | add_preempt_count(PREEMPT_ACTIVE); | |
3a5c359a AK |
4783 | local_irq_enable(); |
4784 | schedule(); | |
4785 | local_irq_disable(); | |
3a5c359a | 4786 | sub_preempt_count(PREEMPT_ACTIVE); |
1da177e4 | 4787 | |
3a5c359a AK |
4788 | /* |
4789 | * Check again in case we missed a preemption opportunity | |
4790 | * between schedule and now. | |
4791 | */ | |
4792 | barrier(); | |
4793 | } while (unlikely(test_thread_flag(TIF_NEED_RESCHED))); | |
1da177e4 LT |
4794 | } |
4795 | ||
4796 | #endif /* CONFIG_PREEMPT */ | |
4797 | ||
95cdf3b7 IM |
4798 | int default_wake_function(wait_queue_t *curr, unsigned mode, int sync, |
4799 | void *key) | |
1da177e4 | 4800 | { |
48f24c4d | 4801 | return try_to_wake_up(curr->private, mode, sync); |
1da177e4 | 4802 | } |
1da177e4 LT |
4803 | EXPORT_SYMBOL(default_wake_function); |
4804 | ||
4805 | /* | |
41a2d6cf IM |
4806 | * The core wakeup function. Non-exclusive wakeups (nr_exclusive == 0) just |
4807 | * wake everything up. If it's an exclusive wakeup (nr_exclusive == small +ve | |
1da177e4 LT |
4808 | * number) then we wake all the non-exclusive tasks and one exclusive task. |
4809 | * | |
4810 | * There are circumstances in which we can try to wake a task which has already | |
41a2d6cf | 4811 | * started to run but is not in state TASK_RUNNING. try_to_wake_up() returns |
1da177e4 LT |
4812 | * zero in this (rare) case, and we handle it by continuing to scan the queue. |
4813 | */ | |
777c6c5f JW |
4814 | void __wake_up_common(wait_queue_head_t *q, unsigned int mode, |
4815 | int nr_exclusive, int sync, void *key) | |
1da177e4 | 4816 | { |
2e45874c | 4817 | wait_queue_t *curr, *next; |
1da177e4 | 4818 | |
2e45874c | 4819 | list_for_each_entry_safe(curr, next, &q->task_list, task_list) { |
48f24c4d IM |
4820 | unsigned flags = curr->flags; |
4821 | ||
1da177e4 | 4822 | if (curr->func(curr, mode, sync, key) && |
48f24c4d | 4823 | (flags & WQ_FLAG_EXCLUSIVE) && !--nr_exclusive) |
1da177e4 LT |
4824 | break; |
4825 | } | |
4826 | } | |
4827 | ||
4828 | /** | |
4829 | * __wake_up - wake up threads blocked on a waitqueue. | |
4830 | * @q: the waitqueue | |
4831 | * @mode: which threads | |
4832 | * @nr_exclusive: how many wake-one or wake-many threads to wake up | |
67be2dd1 | 4833 | * @key: is directly passed to the wakeup function |
1da177e4 | 4834 | */ |
7ad5b3a5 | 4835 | void __wake_up(wait_queue_head_t *q, unsigned int mode, |
95cdf3b7 | 4836 | int nr_exclusive, void *key) |
1da177e4 LT |
4837 | { |
4838 | unsigned long flags; | |
4839 | ||
4840 | spin_lock_irqsave(&q->lock, flags); | |
4841 | __wake_up_common(q, mode, nr_exclusive, 0, key); | |
4842 | spin_unlock_irqrestore(&q->lock, flags); | |
4843 | } | |
1da177e4 LT |
4844 | EXPORT_SYMBOL(__wake_up); |
4845 | ||
4846 | /* | |
4847 | * Same as __wake_up but called with the spinlock in wait_queue_head_t held. | |
4848 | */ | |
7ad5b3a5 | 4849 | void __wake_up_locked(wait_queue_head_t *q, unsigned int mode) |
1da177e4 LT |
4850 | { |
4851 | __wake_up_common(q, mode, 1, 0, NULL); | |
4852 | } | |
4853 | ||
4854 | /** | |
67be2dd1 | 4855 | * __wake_up_sync - wake up threads blocked on a waitqueue. |
1da177e4 LT |
4856 | * @q: the waitqueue |
4857 | * @mode: which threads | |
4858 | * @nr_exclusive: how many wake-one or wake-many threads to wake up | |
4859 | * | |
4860 | * The sync wakeup differs that the waker knows that it will schedule | |
4861 | * away soon, so while the target thread will be woken up, it will not | |
4862 | * be migrated to another CPU - ie. the two threads are 'synchronized' | |
4863 | * with each other. This can prevent needless bouncing between CPUs. | |
4864 | * | |
4865 | * On UP it can prevent extra preemption. | |
4866 | */ | |
7ad5b3a5 | 4867 | void |
95cdf3b7 | 4868 | __wake_up_sync(wait_queue_head_t *q, unsigned int mode, int nr_exclusive) |
1da177e4 LT |
4869 | { |
4870 | unsigned long flags; | |
4871 | int sync = 1; | |
4872 | ||
4873 | if (unlikely(!q)) | |
4874 | return; | |
4875 | ||
4876 | if (unlikely(!nr_exclusive)) | |
4877 | sync = 0; | |
4878 | ||
4879 | spin_lock_irqsave(&q->lock, flags); | |
4880 | __wake_up_common(q, mode, nr_exclusive, sync, NULL); | |
4881 | spin_unlock_irqrestore(&q->lock, flags); | |
4882 | } | |
4883 | EXPORT_SYMBOL_GPL(__wake_up_sync); /* For internal use only */ | |
4884 | ||
65eb3dc6 KD |
4885 | /** |
4886 | * complete: - signals a single thread waiting on this completion | |
4887 | * @x: holds the state of this particular completion | |
4888 | * | |
4889 | * This will wake up a single thread waiting on this completion. Threads will be | |
4890 | * awakened in the same order in which they were queued. | |
4891 | * | |
4892 | * See also complete_all(), wait_for_completion() and related routines. | |
4893 | */ | |
b15136e9 | 4894 | void complete(struct completion *x) |
1da177e4 LT |
4895 | { |
4896 | unsigned long flags; | |
4897 | ||
4898 | spin_lock_irqsave(&x->wait.lock, flags); | |
4899 | x->done++; | |
d9514f6c | 4900 | __wake_up_common(&x->wait, TASK_NORMAL, 1, 0, NULL); |
1da177e4 LT |
4901 | spin_unlock_irqrestore(&x->wait.lock, flags); |
4902 | } | |
4903 | EXPORT_SYMBOL(complete); | |
4904 | ||
65eb3dc6 KD |
4905 | /** |
4906 | * complete_all: - signals all threads waiting on this completion | |
4907 | * @x: holds the state of this particular completion | |
4908 | * | |
4909 | * This will wake up all threads waiting on this particular completion event. | |
4910 | */ | |
b15136e9 | 4911 | void complete_all(struct completion *x) |
1da177e4 LT |
4912 | { |
4913 | unsigned long flags; | |
4914 | ||
4915 | spin_lock_irqsave(&x->wait.lock, flags); | |
4916 | x->done += UINT_MAX/2; | |
d9514f6c | 4917 | __wake_up_common(&x->wait, TASK_NORMAL, 0, 0, NULL); |
1da177e4 LT |
4918 | spin_unlock_irqrestore(&x->wait.lock, flags); |
4919 | } | |
4920 | EXPORT_SYMBOL(complete_all); | |
4921 | ||
8cbbe86d AK |
4922 | static inline long __sched |
4923 | do_wait_for_common(struct completion *x, long timeout, int state) | |
1da177e4 | 4924 | { |
1da177e4 LT |
4925 | if (!x->done) { |
4926 | DECLARE_WAITQUEUE(wait, current); | |
4927 | ||
4928 | wait.flags |= WQ_FLAG_EXCLUSIVE; | |
4929 | __add_wait_queue_tail(&x->wait, &wait); | |
4930 | do { | |
94d3d824 | 4931 | if (signal_pending_state(state, current)) { |
ea71a546 ON |
4932 | timeout = -ERESTARTSYS; |
4933 | break; | |
8cbbe86d AK |
4934 | } |
4935 | __set_current_state(state); | |
1da177e4 LT |
4936 | spin_unlock_irq(&x->wait.lock); |
4937 | timeout = schedule_timeout(timeout); | |
4938 | spin_lock_irq(&x->wait.lock); | |
ea71a546 | 4939 | } while (!x->done && timeout); |
1da177e4 | 4940 | __remove_wait_queue(&x->wait, &wait); |
ea71a546 ON |
4941 | if (!x->done) |
4942 | return timeout; | |
1da177e4 LT |
4943 | } |
4944 | x->done--; | |
ea71a546 | 4945 | return timeout ?: 1; |
1da177e4 | 4946 | } |
1da177e4 | 4947 | |
8cbbe86d AK |
4948 | static long __sched |
4949 | wait_for_common(struct completion *x, long timeout, int state) | |
1da177e4 | 4950 | { |
1da177e4 LT |
4951 | might_sleep(); |
4952 | ||
4953 | spin_lock_irq(&x->wait.lock); | |
8cbbe86d | 4954 | timeout = do_wait_for_common(x, timeout, state); |
1da177e4 | 4955 | spin_unlock_irq(&x->wait.lock); |
8cbbe86d AK |
4956 | return timeout; |
4957 | } | |
1da177e4 | 4958 | |
65eb3dc6 KD |
4959 | /** |
4960 | * wait_for_completion: - waits for completion of a task | |
4961 | * @x: holds the state of this particular completion | |
4962 | * | |
4963 | * This waits to be signaled for completion of a specific task. It is NOT | |
4964 | * interruptible and there is no timeout. | |
4965 | * | |
4966 | * See also similar routines (i.e. wait_for_completion_timeout()) with timeout | |
4967 | * and interrupt capability. Also see complete(). | |
4968 | */ | |
b15136e9 | 4969 | void __sched wait_for_completion(struct completion *x) |
8cbbe86d AK |
4970 | { |
4971 | wait_for_common(x, MAX_SCHEDULE_TIMEOUT, TASK_UNINTERRUPTIBLE); | |
1da177e4 | 4972 | } |
8cbbe86d | 4973 | EXPORT_SYMBOL(wait_for_completion); |
1da177e4 | 4974 | |
65eb3dc6 KD |
4975 | /** |
4976 | * wait_for_completion_timeout: - waits for completion of a task (w/timeout) | |
4977 | * @x: holds the state of this particular completion | |
4978 | * @timeout: timeout value in jiffies | |
4979 | * | |
4980 | * This waits for either a completion of a specific task to be signaled or for a | |
4981 | * specified timeout to expire. The timeout is in jiffies. It is not | |
4982 | * interruptible. | |
4983 | */ | |
b15136e9 | 4984 | unsigned long __sched |
8cbbe86d | 4985 | wait_for_completion_timeout(struct completion *x, unsigned long timeout) |
1da177e4 | 4986 | { |
8cbbe86d | 4987 | return wait_for_common(x, timeout, TASK_UNINTERRUPTIBLE); |
1da177e4 | 4988 | } |
8cbbe86d | 4989 | EXPORT_SYMBOL(wait_for_completion_timeout); |
1da177e4 | 4990 | |
65eb3dc6 KD |
4991 | /** |
4992 | * wait_for_completion_interruptible: - waits for completion of a task (w/intr) | |
4993 | * @x: holds the state of this particular completion | |
4994 | * | |
4995 | * This waits for completion of a specific task to be signaled. It is | |
4996 | * interruptible. | |
4997 | */ | |
8cbbe86d | 4998 | int __sched wait_for_completion_interruptible(struct completion *x) |
0fec171c | 4999 | { |
51e97990 AK |
5000 | long t = wait_for_common(x, MAX_SCHEDULE_TIMEOUT, TASK_INTERRUPTIBLE); |
5001 | if (t == -ERESTARTSYS) | |
5002 | return t; | |
5003 | return 0; | |
0fec171c | 5004 | } |
8cbbe86d | 5005 | EXPORT_SYMBOL(wait_for_completion_interruptible); |
1da177e4 | 5006 | |
65eb3dc6 KD |
5007 | /** |
5008 | * wait_for_completion_interruptible_timeout: - waits for completion (w/(to,intr)) | |
5009 | * @x: holds the state of this particular completion | |
5010 | * @timeout: timeout value in jiffies | |
5011 | * | |
5012 | * This waits for either a completion of a specific task to be signaled or for a | |
5013 | * specified timeout to expire. It is interruptible. The timeout is in jiffies. | |
5014 | */ | |
b15136e9 | 5015 | unsigned long __sched |
8cbbe86d AK |
5016 | wait_for_completion_interruptible_timeout(struct completion *x, |
5017 | unsigned long timeout) | |
0fec171c | 5018 | { |
8cbbe86d | 5019 | return wait_for_common(x, timeout, TASK_INTERRUPTIBLE); |
0fec171c | 5020 | } |
8cbbe86d | 5021 | EXPORT_SYMBOL(wait_for_completion_interruptible_timeout); |
1da177e4 | 5022 | |
65eb3dc6 KD |
5023 | /** |
5024 | * wait_for_completion_killable: - waits for completion of a task (killable) | |
5025 | * @x: holds the state of this particular completion | |
5026 | * | |
5027 | * This waits to be signaled for completion of a specific task. It can be | |
5028 | * interrupted by a kill signal. | |
5029 | */ | |
009e577e MW |
5030 | int __sched wait_for_completion_killable(struct completion *x) |
5031 | { | |
5032 | long t = wait_for_common(x, MAX_SCHEDULE_TIMEOUT, TASK_KILLABLE); | |
5033 | if (t == -ERESTARTSYS) | |
5034 | return t; | |
5035 | return 0; | |
5036 | } | |
5037 | EXPORT_SYMBOL(wait_for_completion_killable); | |
5038 | ||
be4de352 DC |
5039 | /** |
5040 | * try_wait_for_completion - try to decrement a completion without blocking | |
5041 | * @x: completion structure | |
5042 | * | |
5043 | * Returns: 0 if a decrement cannot be done without blocking | |
5044 | * 1 if a decrement succeeded. | |
5045 | * | |
5046 | * If a completion is being used as a counting completion, | |
5047 | * attempt to decrement the counter without blocking. This | |
5048 | * enables us to avoid waiting if the resource the completion | |
5049 | * is protecting is not available. | |
5050 | */ | |
5051 | bool try_wait_for_completion(struct completion *x) | |
5052 | { | |
5053 | int ret = 1; | |
5054 | ||
5055 | spin_lock_irq(&x->wait.lock); | |
5056 | if (!x->done) | |
5057 | ret = 0; | |
5058 | else | |
5059 | x->done--; | |
5060 | spin_unlock_irq(&x->wait.lock); | |
5061 | return ret; | |
5062 | } | |
5063 | EXPORT_SYMBOL(try_wait_for_completion); | |
5064 | ||
5065 | /** | |
5066 | * completion_done - Test to see if a completion has any waiters | |
5067 | * @x: completion structure | |
5068 | * | |
5069 | * Returns: 0 if there are waiters (wait_for_completion() in progress) | |
5070 | * 1 if there are no waiters. | |
5071 | * | |
5072 | */ | |
5073 | bool completion_done(struct completion *x) | |
5074 | { | |
5075 | int ret = 1; | |
5076 | ||
5077 | spin_lock_irq(&x->wait.lock); | |
5078 | if (!x->done) | |
5079 | ret = 0; | |
5080 | spin_unlock_irq(&x->wait.lock); | |
5081 | return ret; | |
5082 | } | |
5083 | EXPORT_SYMBOL(completion_done); | |
5084 | ||
8cbbe86d AK |
5085 | static long __sched |
5086 | sleep_on_common(wait_queue_head_t *q, int state, long timeout) | |
1da177e4 | 5087 | { |
0fec171c IM |
5088 | unsigned long flags; |
5089 | wait_queue_t wait; | |
5090 | ||
5091 | init_waitqueue_entry(&wait, current); | |
1da177e4 | 5092 | |
8cbbe86d | 5093 | __set_current_state(state); |
1da177e4 | 5094 | |
8cbbe86d AK |
5095 | spin_lock_irqsave(&q->lock, flags); |
5096 | __add_wait_queue(q, &wait); | |
5097 | spin_unlock(&q->lock); | |
5098 | timeout = schedule_timeout(timeout); | |
5099 | spin_lock_irq(&q->lock); | |
5100 | __remove_wait_queue(q, &wait); | |
5101 | spin_unlock_irqrestore(&q->lock, flags); | |
5102 | ||
5103 | return timeout; | |
5104 | } | |
5105 | ||
5106 | void __sched interruptible_sleep_on(wait_queue_head_t *q) | |
5107 | { | |
5108 | sleep_on_common(q, TASK_INTERRUPTIBLE, MAX_SCHEDULE_TIMEOUT); | |
1da177e4 | 5109 | } |
1da177e4 LT |
5110 | EXPORT_SYMBOL(interruptible_sleep_on); |
5111 | ||
0fec171c | 5112 | long __sched |
95cdf3b7 | 5113 | interruptible_sleep_on_timeout(wait_queue_head_t *q, long timeout) |
1da177e4 | 5114 | { |
8cbbe86d | 5115 | return sleep_on_common(q, TASK_INTERRUPTIBLE, timeout); |
1da177e4 | 5116 | } |
1da177e4 LT |
5117 | EXPORT_SYMBOL(interruptible_sleep_on_timeout); |
5118 | ||
0fec171c | 5119 | void __sched sleep_on(wait_queue_head_t *q) |
1da177e4 | 5120 | { |
8cbbe86d | 5121 | sleep_on_common(q, TASK_UNINTERRUPTIBLE, MAX_SCHEDULE_TIMEOUT); |
1da177e4 | 5122 | } |
1da177e4 LT |
5123 | EXPORT_SYMBOL(sleep_on); |
5124 | ||
0fec171c | 5125 | long __sched sleep_on_timeout(wait_queue_head_t *q, long timeout) |
1da177e4 | 5126 | { |
8cbbe86d | 5127 | return sleep_on_common(q, TASK_UNINTERRUPTIBLE, timeout); |
1da177e4 | 5128 | } |
1da177e4 LT |
5129 | EXPORT_SYMBOL(sleep_on_timeout); |
5130 | ||
b29739f9 IM |
5131 | #ifdef CONFIG_RT_MUTEXES |
5132 | ||
5133 | /* | |
5134 | * rt_mutex_setprio - set the current priority of a task | |
5135 | * @p: task | |
5136 | * @prio: prio value (kernel-internal form) | |
5137 | * | |
5138 | * This function changes the 'effective' priority of a task. It does | |
5139 | * not touch ->normal_prio like __setscheduler(). | |
5140 | * | |
5141 | * Used by the rt_mutex code to implement priority inheritance logic. | |
5142 | */ | |
36c8b586 | 5143 | void rt_mutex_setprio(struct task_struct *p, int prio) |
b29739f9 IM |
5144 | { |
5145 | unsigned long flags; | |
83b699ed | 5146 | int oldprio, on_rq, running; |
70b97a7f | 5147 | struct rq *rq; |
cb469845 | 5148 | const struct sched_class *prev_class = p->sched_class; |
b29739f9 IM |
5149 | |
5150 | BUG_ON(prio < 0 || prio > MAX_PRIO); | |
5151 | ||
5152 | rq = task_rq_lock(p, &flags); | |
a8e504d2 | 5153 | update_rq_clock(rq); |
b29739f9 | 5154 | |
d5f9f942 | 5155 | oldprio = p->prio; |
dd41f596 | 5156 | on_rq = p->se.on_rq; |
051a1d1a | 5157 | running = task_current(rq, p); |
0e1f3483 | 5158 | if (on_rq) |
69be72c1 | 5159 | dequeue_task(rq, p, 0); |
0e1f3483 HS |
5160 | if (running) |
5161 | p->sched_class->put_prev_task(rq, p); | |
dd41f596 IM |
5162 | |
5163 | if (rt_prio(prio)) | |
5164 | p->sched_class = &rt_sched_class; | |
5165 | else | |
5166 | p->sched_class = &fair_sched_class; | |
5167 | ||
b29739f9 IM |
5168 | p->prio = prio; |
5169 | ||
0e1f3483 HS |
5170 | if (running) |
5171 | p->sched_class->set_curr_task(rq); | |
dd41f596 | 5172 | if (on_rq) { |
8159f87e | 5173 | enqueue_task(rq, p, 0); |
cb469845 SR |
5174 | |
5175 | check_class_changed(rq, p, prev_class, oldprio, running); | |
b29739f9 IM |
5176 | } |
5177 | task_rq_unlock(rq, &flags); | |
5178 | } | |
5179 | ||
5180 | #endif | |
5181 | ||
36c8b586 | 5182 | void set_user_nice(struct task_struct *p, long nice) |
1da177e4 | 5183 | { |
dd41f596 | 5184 | int old_prio, delta, on_rq; |
1da177e4 | 5185 | unsigned long flags; |
70b97a7f | 5186 | struct rq *rq; |
1da177e4 LT |
5187 | |
5188 | if (TASK_NICE(p) == nice || nice < -20 || nice > 19) | |
5189 | return; | |
5190 | /* | |
5191 | * We have to be careful, if called from sys_setpriority(), | |
5192 | * the task might be in the middle of scheduling on another CPU. | |
5193 | */ | |
5194 | rq = task_rq_lock(p, &flags); | |
a8e504d2 | 5195 | update_rq_clock(rq); |
1da177e4 LT |
5196 | /* |
5197 | * The RT priorities are set via sched_setscheduler(), but we still | |
5198 | * allow the 'normal' nice value to be set - but as expected | |
5199 | * it wont have any effect on scheduling until the task is | |
dd41f596 | 5200 | * SCHED_FIFO/SCHED_RR: |
1da177e4 | 5201 | */ |
e05606d3 | 5202 | if (task_has_rt_policy(p)) { |
1da177e4 LT |
5203 | p->static_prio = NICE_TO_PRIO(nice); |
5204 | goto out_unlock; | |
5205 | } | |
dd41f596 | 5206 | on_rq = p->se.on_rq; |
c09595f6 | 5207 | if (on_rq) |
69be72c1 | 5208 | dequeue_task(rq, p, 0); |
1da177e4 | 5209 | |
1da177e4 | 5210 | p->static_prio = NICE_TO_PRIO(nice); |
2dd73a4f | 5211 | set_load_weight(p); |
b29739f9 IM |
5212 | old_prio = p->prio; |
5213 | p->prio = effective_prio(p); | |
5214 | delta = p->prio - old_prio; | |
1da177e4 | 5215 | |
dd41f596 | 5216 | if (on_rq) { |
8159f87e | 5217 | enqueue_task(rq, p, 0); |
1da177e4 | 5218 | /* |
d5f9f942 AM |
5219 | * If the task increased its priority or is running and |
5220 | * lowered its priority, then reschedule its CPU: | |
1da177e4 | 5221 | */ |
d5f9f942 | 5222 | if (delta < 0 || (delta > 0 && task_running(rq, p))) |
1da177e4 LT |
5223 | resched_task(rq->curr); |
5224 | } | |
5225 | out_unlock: | |
5226 | task_rq_unlock(rq, &flags); | |
5227 | } | |
1da177e4 LT |
5228 | EXPORT_SYMBOL(set_user_nice); |
5229 | ||
e43379f1 MM |
5230 | /* |
5231 | * can_nice - check if a task can reduce its nice value | |
5232 | * @p: task | |
5233 | * @nice: nice value | |
5234 | */ | |
36c8b586 | 5235 | int can_nice(const struct task_struct *p, const int nice) |
e43379f1 | 5236 | { |
024f4747 MM |
5237 | /* convert nice value [19,-20] to rlimit style value [1,40] */ |
5238 | int nice_rlim = 20 - nice; | |
48f24c4d | 5239 | |
e43379f1 MM |
5240 | return (nice_rlim <= p->signal->rlim[RLIMIT_NICE].rlim_cur || |
5241 | capable(CAP_SYS_NICE)); | |
5242 | } | |
5243 | ||
1da177e4 LT |
5244 | #ifdef __ARCH_WANT_SYS_NICE |
5245 | ||
5246 | /* | |
5247 | * sys_nice - change the priority of the current process. | |
5248 | * @increment: priority increment | |
5249 | * | |
5250 | * sys_setpriority is a more generic, but much slower function that | |
5251 | * does similar things. | |
5252 | */ | |
5add95d4 | 5253 | SYSCALL_DEFINE1(nice, int, increment) |
1da177e4 | 5254 | { |
48f24c4d | 5255 | long nice, retval; |
1da177e4 LT |
5256 | |
5257 | /* | |
5258 | * Setpriority might change our priority at the same moment. | |
5259 | * We don't have to worry. Conceptually one call occurs first | |
5260 | * and we have a single winner. | |
5261 | */ | |
e43379f1 MM |
5262 | if (increment < -40) |
5263 | increment = -40; | |
1da177e4 LT |
5264 | if (increment > 40) |
5265 | increment = 40; | |
5266 | ||
5267 | nice = PRIO_TO_NICE(current->static_prio) + increment; | |
5268 | if (nice < -20) | |
5269 | nice = -20; | |
5270 | if (nice > 19) | |
5271 | nice = 19; | |
5272 | ||
e43379f1 MM |
5273 | if (increment < 0 && !can_nice(current, nice)) |
5274 | return -EPERM; | |
5275 | ||
1da177e4 LT |
5276 | retval = security_task_setnice(current, nice); |
5277 | if (retval) | |
5278 | return retval; | |
5279 | ||
5280 | set_user_nice(current, nice); | |
5281 | return 0; | |
5282 | } | |
5283 | ||
5284 | #endif | |
5285 | ||
5286 | /** | |
5287 | * task_prio - return the priority value of a given task. | |
5288 | * @p: the task in question. | |
5289 | * | |
5290 | * This is the priority value as seen by users in /proc. | |
5291 | * RT tasks are offset by -200. Normal tasks are centered | |
5292 | * around 0, value goes from -16 to +15. | |
5293 | */ | |
36c8b586 | 5294 | int task_prio(const struct task_struct *p) |
1da177e4 LT |
5295 | { |
5296 | return p->prio - MAX_RT_PRIO; | |
5297 | } | |
5298 | ||
5299 | /** | |
5300 | * task_nice - return the nice value of a given task. | |
5301 | * @p: the task in question. | |
5302 | */ | |
36c8b586 | 5303 | int task_nice(const struct task_struct *p) |
1da177e4 LT |
5304 | { |
5305 | return TASK_NICE(p); | |
5306 | } | |
150d8bed | 5307 | EXPORT_SYMBOL(task_nice); |
1da177e4 LT |
5308 | |
5309 | /** | |
5310 | * idle_cpu - is a given cpu idle currently? | |
5311 | * @cpu: the processor in question. | |
5312 | */ | |
5313 | int idle_cpu(int cpu) | |
5314 | { | |
5315 | return cpu_curr(cpu) == cpu_rq(cpu)->idle; | |
5316 | } | |
5317 | ||
1da177e4 LT |
5318 | /** |
5319 | * idle_task - return the idle task for a given cpu. | |
5320 | * @cpu: the processor in question. | |
5321 | */ | |
36c8b586 | 5322 | struct task_struct *idle_task(int cpu) |
1da177e4 LT |
5323 | { |
5324 | return cpu_rq(cpu)->idle; | |
5325 | } | |
5326 | ||
5327 | /** | |
5328 | * find_process_by_pid - find a process with a matching PID value. | |
5329 | * @pid: the pid in question. | |
5330 | */ | |
a9957449 | 5331 | static struct task_struct *find_process_by_pid(pid_t pid) |
1da177e4 | 5332 | { |
228ebcbe | 5333 | return pid ? find_task_by_vpid(pid) : current; |
1da177e4 LT |
5334 | } |
5335 | ||
5336 | /* Actually do priority change: must hold rq lock. */ | |
dd41f596 IM |
5337 | static void |
5338 | __setscheduler(struct rq *rq, struct task_struct *p, int policy, int prio) | |
1da177e4 | 5339 | { |
dd41f596 | 5340 | BUG_ON(p->se.on_rq); |
48f24c4d | 5341 | |
1da177e4 | 5342 | p->policy = policy; |
dd41f596 IM |
5343 | switch (p->policy) { |
5344 | case SCHED_NORMAL: | |
5345 | case SCHED_BATCH: | |
5346 | case SCHED_IDLE: | |
5347 | p->sched_class = &fair_sched_class; | |
5348 | break; | |
5349 | case SCHED_FIFO: | |
5350 | case SCHED_RR: | |
5351 | p->sched_class = &rt_sched_class; | |
5352 | break; | |
5353 | } | |
5354 | ||
1da177e4 | 5355 | p->rt_priority = prio; |
b29739f9 IM |
5356 | p->normal_prio = normal_prio(p); |
5357 | /* we are holding p->pi_lock already */ | |
5358 | p->prio = rt_mutex_getprio(p); | |
2dd73a4f | 5359 | set_load_weight(p); |
1da177e4 LT |
5360 | } |
5361 | ||
c69e8d9c DH |
5362 | /* |
5363 | * check the target process has a UID that matches the current process's | |
5364 | */ | |
5365 | static bool check_same_owner(struct task_struct *p) | |
5366 | { | |
5367 | const struct cred *cred = current_cred(), *pcred; | |
5368 | bool match; | |
5369 | ||
5370 | rcu_read_lock(); | |
5371 | pcred = __task_cred(p); | |
5372 | match = (cred->euid == pcred->euid || | |
5373 | cred->euid == pcred->uid); | |
5374 | rcu_read_unlock(); | |
5375 | return match; | |
5376 | } | |
5377 | ||
961ccddd RR |
5378 | static int __sched_setscheduler(struct task_struct *p, int policy, |
5379 | struct sched_param *param, bool user) | |
1da177e4 | 5380 | { |
83b699ed | 5381 | int retval, oldprio, oldpolicy = -1, on_rq, running; |
1da177e4 | 5382 | unsigned long flags; |
cb469845 | 5383 | const struct sched_class *prev_class = p->sched_class; |
70b97a7f | 5384 | struct rq *rq; |
1da177e4 | 5385 | |
66e5393a SR |
5386 | /* may grab non-irq protected spin_locks */ |
5387 | BUG_ON(in_interrupt()); | |
1da177e4 LT |
5388 | recheck: |
5389 | /* double check policy once rq lock held */ | |
5390 | if (policy < 0) | |
5391 | policy = oldpolicy = p->policy; | |
5392 | else if (policy != SCHED_FIFO && policy != SCHED_RR && | |
dd41f596 IM |
5393 | policy != SCHED_NORMAL && policy != SCHED_BATCH && |
5394 | policy != SCHED_IDLE) | |
b0a9499c | 5395 | return -EINVAL; |
1da177e4 LT |
5396 | /* |
5397 | * Valid priorities for SCHED_FIFO and SCHED_RR are | |
dd41f596 IM |
5398 | * 1..MAX_USER_RT_PRIO-1, valid priority for SCHED_NORMAL, |
5399 | * SCHED_BATCH and SCHED_IDLE is 0. | |
1da177e4 LT |
5400 | */ |
5401 | if (param->sched_priority < 0 || | |
95cdf3b7 | 5402 | (p->mm && param->sched_priority > MAX_USER_RT_PRIO-1) || |
d46523ea | 5403 | (!p->mm && param->sched_priority > MAX_RT_PRIO-1)) |
1da177e4 | 5404 | return -EINVAL; |
e05606d3 | 5405 | if (rt_policy(policy) != (param->sched_priority != 0)) |
1da177e4 LT |
5406 | return -EINVAL; |
5407 | ||
37e4ab3f OC |
5408 | /* |
5409 | * Allow unprivileged RT tasks to decrease priority: | |
5410 | */ | |
961ccddd | 5411 | if (user && !capable(CAP_SYS_NICE)) { |
e05606d3 | 5412 | if (rt_policy(policy)) { |
8dc3e909 | 5413 | unsigned long rlim_rtprio; |
8dc3e909 ON |
5414 | |
5415 | if (!lock_task_sighand(p, &flags)) | |
5416 | return -ESRCH; | |
5417 | rlim_rtprio = p->signal->rlim[RLIMIT_RTPRIO].rlim_cur; | |
5418 | unlock_task_sighand(p, &flags); | |
5419 | ||
5420 | /* can't set/change the rt policy */ | |
5421 | if (policy != p->policy && !rlim_rtprio) | |
5422 | return -EPERM; | |
5423 | ||
5424 | /* can't increase priority */ | |
5425 | if (param->sched_priority > p->rt_priority && | |
5426 | param->sched_priority > rlim_rtprio) | |
5427 | return -EPERM; | |
5428 | } | |
dd41f596 IM |
5429 | /* |
5430 | * Like positive nice levels, dont allow tasks to | |
5431 | * move out of SCHED_IDLE either: | |
5432 | */ | |
5433 | if (p->policy == SCHED_IDLE && policy != SCHED_IDLE) | |
5434 | return -EPERM; | |
5fe1d75f | 5435 | |
37e4ab3f | 5436 | /* can't change other user's priorities */ |
c69e8d9c | 5437 | if (!check_same_owner(p)) |
37e4ab3f OC |
5438 | return -EPERM; |
5439 | } | |
1da177e4 | 5440 | |
725aad24 | 5441 | if (user) { |
b68aa230 | 5442 | #ifdef CONFIG_RT_GROUP_SCHED |
725aad24 JF |
5443 | /* |
5444 | * Do not allow realtime tasks into groups that have no runtime | |
5445 | * assigned. | |
5446 | */ | |
9a7e0b18 PZ |
5447 | if (rt_bandwidth_enabled() && rt_policy(policy) && |
5448 | task_group(p)->rt_bandwidth.rt_runtime == 0) | |
725aad24 | 5449 | return -EPERM; |
b68aa230 PZ |
5450 | #endif |
5451 | ||
725aad24 JF |
5452 | retval = security_task_setscheduler(p, policy, param); |
5453 | if (retval) | |
5454 | return retval; | |
5455 | } | |
5456 | ||
b29739f9 IM |
5457 | /* |
5458 | * make sure no PI-waiters arrive (or leave) while we are | |
5459 | * changing the priority of the task: | |
5460 | */ | |
5461 | spin_lock_irqsave(&p->pi_lock, flags); | |
1da177e4 LT |
5462 | /* |
5463 | * To be able to change p->policy safely, the apropriate | |
5464 | * runqueue lock must be held. | |
5465 | */ | |
b29739f9 | 5466 | rq = __task_rq_lock(p); |
1da177e4 LT |
5467 | /* recheck policy now with rq lock held */ |
5468 | if (unlikely(oldpolicy != -1 && oldpolicy != p->policy)) { | |
5469 | policy = oldpolicy = -1; | |
b29739f9 IM |
5470 | __task_rq_unlock(rq); |
5471 | spin_unlock_irqrestore(&p->pi_lock, flags); | |
1da177e4 LT |
5472 | goto recheck; |
5473 | } | |
2daa3577 | 5474 | update_rq_clock(rq); |
dd41f596 | 5475 | on_rq = p->se.on_rq; |
051a1d1a | 5476 | running = task_current(rq, p); |
0e1f3483 | 5477 | if (on_rq) |
2e1cb74a | 5478 | deactivate_task(rq, p, 0); |
0e1f3483 HS |
5479 | if (running) |
5480 | p->sched_class->put_prev_task(rq, p); | |
f6b53205 | 5481 | |
1da177e4 | 5482 | oldprio = p->prio; |
dd41f596 | 5483 | __setscheduler(rq, p, policy, param->sched_priority); |
f6b53205 | 5484 | |
0e1f3483 HS |
5485 | if (running) |
5486 | p->sched_class->set_curr_task(rq); | |
dd41f596 IM |
5487 | if (on_rq) { |
5488 | activate_task(rq, p, 0); | |
cb469845 SR |
5489 | |
5490 | check_class_changed(rq, p, prev_class, oldprio, running); | |
1da177e4 | 5491 | } |
b29739f9 IM |
5492 | __task_rq_unlock(rq); |
5493 | spin_unlock_irqrestore(&p->pi_lock, flags); | |
5494 | ||
95e02ca9 TG |
5495 | rt_mutex_adjust_pi(p); |
5496 | ||
1da177e4 LT |
5497 | return 0; |
5498 | } | |
961ccddd RR |
5499 | |
5500 | /** | |
5501 | * sched_setscheduler - change the scheduling policy and/or RT priority of a thread. | |
5502 | * @p: the task in question. | |
5503 | * @policy: new policy. | |
5504 | * @param: structure containing the new RT priority. | |
5505 | * | |
5506 | * NOTE that the task may be already dead. | |
5507 | */ | |
5508 | int sched_setscheduler(struct task_struct *p, int policy, | |
5509 | struct sched_param *param) | |
5510 | { | |
5511 | return __sched_setscheduler(p, policy, param, true); | |
5512 | } | |
1da177e4 LT |
5513 | EXPORT_SYMBOL_GPL(sched_setscheduler); |
5514 | ||
961ccddd RR |
5515 | /** |
5516 | * sched_setscheduler_nocheck - change the scheduling policy and/or RT priority of a thread from kernelspace. | |
5517 | * @p: the task in question. | |
5518 | * @policy: new policy. | |
5519 | * @param: structure containing the new RT priority. | |
5520 | * | |
5521 | * Just like sched_setscheduler, only don't bother checking if the | |
5522 | * current context has permission. For example, this is needed in | |
5523 | * stop_machine(): we create temporary high priority worker threads, | |
5524 | * but our caller might not have that capability. | |
5525 | */ | |
5526 | int sched_setscheduler_nocheck(struct task_struct *p, int policy, | |
5527 | struct sched_param *param) | |
5528 | { | |
5529 | return __sched_setscheduler(p, policy, param, false); | |
5530 | } | |
5531 | ||
95cdf3b7 IM |
5532 | static int |
5533 | do_sched_setscheduler(pid_t pid, int policy, struct sched_param __user *param) | |
1da177e4 | 5534 | { |
1da177e4 LT |
5535 | struct sched_param lparam; |
5536 | struct task_struct *p; | |
36c8b586 | 5537 | int retval; |
1da177e4 LT |
5538 | |
5539 | if (!param || pid < 0) | |
5540 | return -EINVAL; | |
5541 | if (copy_from_user(&lparam, param, sizeof(struct sched_param))) | |
5542 | return -EFAULT; | |
5fe1d75f ON |
5543 | |
5544 | rcu_read_lock(); | |
5545 | retval = -ESRCH; | |
1da177e4 | 5546 | p = find_process_by_pid(pid); |
5fe1d75f ON |
5547 | if (p != NULL) |
5548 | retval = sched_setscheduler(p, policy, &lparam); | |
5549 | rcu_read_unlock(); | |
36c8b586 | 5550 | |
1da177e4 LT |
5551 | return retval; |
5552 | } | |
5553 | ||
5554 | /** | |
5555 | * sys_sched_setscheduler - set/change the scheduler policy and RT priority | |
5556 | * @pid: the pid in question. | |
5557 | * @policy: new policy. | |
5558 | * @param: structure containing the new RT priority. | |
5559 | */ | |
5add95d4 HC |
5560 | SYSCALL_DEFINE3(sched_setscheduler, pid_t, pid, int, policy, |
5561 | struct sched_param __user *, param) | |
1da177e4 | 5562 | { |
c21761f1 JB |
5563 | /* negative values for policy are not valid */ |
5564 | if (policy < 0) | |
5565 | return -EINVAL; | |
5566 | ||
1da177e4 LT |
5567 | return do_sched_setscheduler(pid, policy, param); |
5568 | } | |
5569 | ||
5570 | /** | |
5571 | * sys_sched_setparam - set/change the RT priority of a thread | |
5572 | * @pid: the pid in question. | |
5573 | * @param: structure containing the new RT priority. | |
5574 | */ | |
5add95d4 | 5575 | SYSCALL_DEFINE2(sched_setparam, pid_t, pid, struct sched_param __user *, param) |
1da177e4 LT |
5576 | { |
5577 | return do_sched_setscheduler(pid, -1, param); | |
5578 | } | |
5579 | ||
5580 | /** | |
5581 | * sys_sched_getscheduler - get the policy (scheduling class) of a thread | |
5582 | * @pid: the pid in question. | |
5583 | */ | |
5add95d4 | 5584 | SYSCALL_DEFINE1(sched_getscheduler, pid_t, pid) |
1da177e4 | 5585 | { |
36c8b586 | 5586 | struct task_struct *p; |
3a5c359a | 5587 | int retval; |
1da177e4 LT |
5588 | |
5589 | if (pid < 0) | |
3a5c359a | 5590 | return -EINVAL; |
1da177e4 LT |
5591 | |
5592 | retval = -ESRCH; | |
5593 | read_lock(&tasklist_lock); | |
5594 | p = find_process_by_pid(pid); | |
5595 | if (p) { | |
5596 | retval = security_task_getscheduler(p); | |
5597 | if (!retval) | |
5598 | retval = p->policy; | |
5599 | } | |
5600 | read_unlock(&tasklist_lock); | |
1da177e4 LT |
5601 | return retval; |
5602 | } | |
5603 | ||
5604 | /** | |
5605 | * sys_sched_getscheduler - get the RT priority of a thread | |
5606 | * @pid: the pid in question. | |
5607 | * @param: structure containing the RT priority. | |
5608 | */ | |
5add95d4 | 5609 | SYSCALL_DEFINE2(sched_getparam, pid_t, pid, struct sched_param __user *, param) |
1da177e4 LT |
5610 | { |
5611 | struct sched_param lp; | |
36c8b586 | 5612 | struct task_struct *p; |
3a5c359a | 5613 | int retval; |
1da177e4 LT |
5614 | |
5615 | if (!param || pid < 0) | |
3a5c359a | 5616 | return -EINVAL; |
1da177e4 LT |
5617 | |
5618 | read_lock(&tasklist_lock); | |
5619 | p = find_process_by_pid(pid); | |
5620 | retval = -ESRCH; | |
5621 | if (!p) | |
5622 | goto out_unlock; | |
5623 | ||
5624 | retval = security_task_getscheduler(p); | |
5625 | if (retval) | |
5626 | goto out_unlock; | |
5627 | ||
5628 | lp.sched_priority = p->rt_priority; | |
5629 | read_unlock(&tasklist_lock); | |
5630 | ||
5631 | /* | |
5632 | * This one might sleep, we cannot do it with a spinlock held ... | |
5633 | */ | |
5634 | retval = copy_to_user(param, &lp, sizeof(*param)) ? -EFAULT : 0; | |
5635 | ||
1da177e4 LT |
5636 | return retval; |
5637 | ||
5638 | out_unlock: | |
5639 | read_unlock(&tasklist_lock); | |
5640 | return retval; | |
5641 | } | |
5642 | ||
96f874e2 | 5643 | long sched_setaffinity(pid_t pid, const struct cpumask *in_mask) |
1da177e4 | 5644 | { |
5a16f3d3 | 5645 | cpumask_var_t cpus_allowed, new_mask; |
36c8b586 IM |
5646 | struct task_struct *p; |
5647 | int retval; | |
1da177e4 | 5648 | |
95402b38 | 5649 | get_online_cpus(); |
1da177e4 LT |
5650 | read_lock(&tasklist_lock); |
5651 | ||
5652 | p = find_process_by_pid(pid); | |
5653 | if (!p) { | |
5654 | read_unlock(&tasklist_lock); | |
95402b38 | 5655 | put_online_cpus(); |
1da177e4 LT |
5656 | return -ESRCH; |
5657 | } | |
5658 | ||
5659 | /* | |
5660 | * It is not safe to call set_cpus_allowed with the | |
41a2d6cf | 5661 | * tasklist_lock held. We will bump the task_struct's |
1da177e4 LT |
5662 | * usage count and then drop tasklist_lock. |
5663 | */ | |
5664 | get_task_struct(p); | |
5665 | read_unlock(&tasklist_lock); | |
5666 | ||
5a16f3d3 RR |
5667 | if (!alloc_cpumask_var(&cpus_allowed, GFP_KERNEL)) { |
5668 | retval = -ENOMEM; | |
5669 | goto out_put_task; | |
5670 | } | |
5671 | if (!alloc_cpumask_var(&new_mask, GFP_KERNEL)) { | |
5672 | retval = -ENOMEM; | |
5673 | goto out_free_cpus_allowed; | |
5674 | } | |
1da177e4 | 5675 | retval = -EPERM; |
c69e8d9c | 5676 | if (!check_same_owner(p) && !capable(CAP_SYS_NICE)) |
1da177e4 LT |
5677 | goto out_unlock; |
5678 | ||
e7834f8f DQ |
5679 | retval = security_task_setscheduler(p, 0, NULL); |
5680 | if (retval) | |
5681 | goto out_unlock; | |
5682 | ||
5a16f3d3 RR |
5683 | cpuset_cpus_allowed(p, cpus_allowed); |
5684 | cpumask_and(new_mask, in_mask, cpus_allowed); | |
8707d8b8 | 5685 | again: |
5a16f3d3 | 5686 | retval = set_cpus_allowed_ptr(p, new_mask); |
1da177e4 | 5687 | |
8707d8b8 | 5688 | if (!retval) { |
5a16f3d3 RR |
5689 | cpuset_cpus_allowed(p, cpus_allowed); |
5690 | if (!cpumask_subset(new_mask, cpus_allowed)) { | |
8707d8b8 PM |
5691 | /* |
5692 | * We must have raced with a concurrent cpuset | |
5693 | * update. Just reset the cpus_allowed to the | |
5694 | * cpuset's cpus_allowed | |
5695 | */ | |
5a16f3d3 | 5696 | cpumask_copy(new_mask, cpus_allowed); |
8707d8b8 PM |
5697 | goto again; |
5698 | } | |
5699 | } | |
1da177e4 | 5700 | out_unlock: |
5a16f3d3 RR |
5701 | free_cpumask_var(new_mask); |
5702 | out_free_cpus_allowed: | |
5703 | free_cpumask_var(cpus_allowed); | |
5704 | out_put_task: | |
1da177e4 | 5705 | put_task_struct(p); |
95402b38 | 5706 | put_online_cpus(); |
1da177e4 LT |
5707 | return retval; |
5708 | } | |
5709 | ||
5710 | static int get_user_cpu_mask(unsigned long __user *user_mask_ptr, unsigned len, | |
96f874e2 | 5711 | struct cpumask *new_mask) |
1da177e4 | 5712 | { |
96f874e2 RR |
5713 | if (len < cpumask_size()) |
5714 | cpumask_clear(new_mask); | |
5715 | else if (len > cpumask_size()) | |
5716 | len = cpumask_size(); | |
5717 | ||
1da177e4 LT |
5718 | return copy_from_user(new_mask, user_mask_ptr, len) ? -EFAULT : 0; |
5719 | } | |
5720 | ||
5721 | /** | |
5722 | * sys_sched_setaffinity - set the cpu affinity of a process | |
5723 | * @pid: pid of the process | |
5724 | * @len: length in bytes of the bitmask pointed to by user_mask_ptr | |
5725 | * @user_mask_ptr: user-space pointer to the new cpu mask | |
5726 | */ | |
5add95d4 HC |
5727 | SYSCALL_DEFINE3(sched_setaffinity, pid_t, pid, unsigned int, len, |
5728 | unsigned long __user *, user_mask_ptr) | |
1da177e4 | 5729 | { |
5a16f3d3 | 5730 | cpumask_var_t new_mask; |
1da177e4 LT |
5731 | int retval; |
5732 | ||
5a16f3d3 RR |
5733 | if (!alloc_cpumask_var(&new_mask, GFP_KERNEL)) |
5734 | return -ENOMEM; | |
1da177e4 | 5735 | |
5a16f3d3 RR |
5736 | retval = get_user_cpu_mask(user_mask_ptr, len, new_mask); |
5737 | if (retval == 0) | |
5738 | retval = sched_setaffinity(pid, new_mask); | |
5739 | free_cpumask_var(new_mask); | |
5740 | return retval; | |
1da177e4 LT |
5741 | } |
5742 | ||
96f874e2 | 5743 | long sched_getaffinity(pid_t pid, struct cpumask *mask) |
1da177e4 | 5744 | { |
36c8b586 | 5745 | struct task_struct *p; |
1da177e4 | 5746 | int retval; |
1da177e4 | 5747 | |
95402b38 | 5748 | get_online_cpus(); |
1da177e4 LT |
5749 | read_lock(&tasklist_lock); |
5750 | ||
5751 | retval = -ESRCH; | |
5752 | p = find_process_by_pid(pid); | |
5753 | if (!p) | |
5754 | goto out_unlock; | |
5755 | ||
e7834f8f DQ |
5756 | retval = security_task_getscheduler(p); |
5757 | if (retval) | |
5758 | goto out_unlock; | |
5759 | ||
96f874e2 | 5760 | cpumask_and(mask, &p->cpus_allowed, cpu_online_mask); |
1da177e4 LT |
5761 | |
5762 | out_unlock: | |
5763 | read_unlock(&tasklist_lock); | |
95402b38 | 5764 | put_online_cpus(); |
1da177e4 | 5765 | |
9531b62f | 5766 | return retval; |
1da177e4 LT |
5767 | } |
5768 | ||
5769 | /** | |
5770 | * sys_sched_getaffinity - get the cpu affinity of a process | |
5771 | * @pid: pid of the process | |
5772 | * @len: length in bytes of the bitmask pointed to by user_mask_ptr | |
5773 | * @user_mask_ptr: user-space pointer to hold the current cpu mask | |
5774 | */ | |
5add95d4 HC |
5775 | SYSCALL_DEFINE3(sched_getaffinity, pid_t, pid, unsigned int, len, |
5776 | unsigned long __user *, user_mask_ptr) | |
1da177e4 LT |
5777 | { |
5778 | int ret; | |
f17c8607 | 5779 | cpumask_var_t mask; |
1da177e4 | 5780 | |
f17c8607 | 5781 | if (len < cpumask_size()) |
1da177e4 LT |
5782 | return -EINVAL; |
5783 | ||
f17c8607 RR |
5784 | if (!alloc_cpumask_var(&mask, GFP_KERNEL)) |
5785 | return -ENOMEM; | |
1da177e4 | 5786 | |
f17c8607 RR |
5787 | ret = sched_getaffinity(pid, mask); |
5788 | if (ret == 0) { | |
5789 | if (copy_to_user(user_mask_ptr, mask, cpumask_size())) | |
5790 | ret = -EFAULT; | |
5791 | else | |
5792 | ret = cpumask_size(); | |
5793 | } | |
5794 | free_cpumask_var(mask); | |
1da177e4 | 5795 | |
f17c8607 | 5796 | return ret; |
1da177e4 LT |
5797 | } |
5798 | ||
5799 | /** | |
5800 | * sys_sched_yield - yield the current processor to other threads. | |
5801 | * | |
dd41f596 IM |
5802 | * This function yields the current CPU to other tasks. If there are no |
5803 | * other threads running on this CPU then this function will return. | |
1da177e4 | 5804 | */ |
5add95d4 | 5805 | SYSCALL_DEFINE0(sched_yield) |
1da177e4 | 5806 | { |
70b97a7f | 5807 | struct rq *rq = this_rq_lock(); |
1da177e4 | 5808 | |
2d72376b | 5809 | schedstat_inc(rq, yld_count); |
4530d7ab | 5810 | current->sched_class->yield_task(rq); |
1da177e4 LT |
5811 | |
5812 | /* | |
5813 | * Since we are going to call schedule() anyway, there's | |
5814 | * no need to preempt or enable interrupts: | |
5815 | */ | |
5816 | __release(rq->lock); | |
8a25d5de | 5817 | spin_release(&rq->lock.dep_map, 1, _THIS_IP_); |
1da177e4 LT |
5818 | _raw_spin_unlock(&rq->lock); |
5819 | preempt_enable_no_resched(); | |
5820 | ||
5821 | schedule(); | |
5822 | ||
5823 | return 0; | |
5824 | } | |
5825 | ||
e7b38404 | 5826 | static void __cond_resched(void) |
1da177e4 | 5827 | { |
8e0a43d8 IM |
5828 | #ifdef CONFIG_DEBUG_SPINLOCK_SLEEP |
5829 | __might_sleep(__FILE__, __LINE__); | |
5830 | #endif | |
5bbcfd90 IM |
5831 | /* |
5832 | * The BKS might be reacquired before we have dropped | |
5833 | * PREEMPT_ACTIVE, which could trigger a second | |
5834 | * cond_resched() call. | |
5835 | */ | |
1da177e4 LT |
5836 | do { |
5837 | add_preempt_count(PREEMPT_ACTIVE); | |
5838 | schedule(); | |
5839 | sub_preempt_count(PREEMPT_ACTIVE); | |
5840 | } while (need_resched()); | |
5841 | } | |
5842 | ||
02b67cc3 | 5843 | int __sched _cond_resched(void) |
1da177e4 | 5844 | { |
9414232f IM |
5845 | if (need_resched() && !(preempt_count() & PREEMPT_ACTIVE) && |
5846 | system_state == SYSTEM_RUNNING) { | |
1da177e4 LT |
5847 | __cond_resched(); |
5848 | return 1; | |
5849 | } | |
5850 | return 0; | |
5851 | } | |
02b67cc3 | 5852 | EXPORT_SYMBOL(_cond_resched); |
1da177e4 LT |
5853 | |
5854 | /* | |
5855 | * cond_resched_lock() - if a reschedule is pending, drop the given lock, | |
5856 | * call schedule, and on return reacquire the lock. | |
5857 | * | |
41a2d6cf | 5858 | * This works OK both with and without CONFIG_PREEMPT. We do strange low-level |
1da177e4 LT |
5859 | * operations here to prevent schedule() from being called twice (once via |
5860 | * spin_unlock(), once by hand). | |
5861 | */ | |
95cdf3b7 | 5862 | int cond_resched_lock(spinlock_t *lock) |
1da177e4 | 5863 | { |
95c354fe | 5864 | int resched = need_resched() && system_state == SYSTEM_RUNNING; |
6df3cecb JK |
5865 | int ret = 0; |
5866 | ||
95c354fe | 5867 | if (spin_needbreak(lock) || resched) { |
1da177e4 | 5868 | spin_unlock(lock); |
95c354fe NP |
5869 | if (resched && need_resched()) |
5870 | __cond_resched(); | |
5871 | else | |
5872 | cpu_relax(); | |
6df3cecb | 5873 | ret = 1; |
1da177e4 | 5874 | spin_lock(lock); |
1da177e4 | 5875 | } |
6df3cecb | 5876 | return ret; |
1da177e4 | 5877 | } |
1da177e4 LT |
5878 | EXPORT_SYMBOL(cond_resched_lock); |
5879 | ||
5880 | int __sched cond_resched_softirq(void) | |
5881 | { | |
5882 | BUG_ON(!in_softirq()); | |
5883 | ||
9414232f | 5884 | if (need_resched() && system_state == SYSTEM_RUNNING) { |
98d82567 | 5885 | local_bh_enable(); |
1da177e4 LT |
5886 | __cond_resched(); |
5887 | local_bh_disable(); | |
5888 | return 1; | |
5889 | } | |
5890 | return 0; | |
5891 | } | |
1da177e4 LT |
5892 | EXPORT_SYMBOL(cond_resched_softirq); |
5893 | ||
1da177e4 LT |
5894 | /** |
5895 | * yield - yield the current processor to other threads. | |
5896 | * | |
72fd4a35 | 5897 | * This is a shortcut for kernel-space yielding - it marks the |
1da177e4 LT |
5898 | * thread runnable and calls sys_sched_yield(). |
5899 | */ | |
5900 | void __sched yield(void) | |
5901 | { | |
5902 | set_current_state(TASK_RUNNING); | |
5903 | sys_sched_yield(); | |
5904 | } | |
1da177e4 LT |
5905 | EXPORT_SYMBOL(yield); |
5906 | ||
5907 | /* | |
41a2d6cf | 5908 | * This task is about to go to sleep on IO. Increment rq->nr_iowait so |
1da177e4 LT |
5909 | * that process accounting knows that this is a task in IO wait state. |
5910 | * | |
5911 | * But don't do that if it is a deliberate, throttling IO wait (this task | |
5912 | * has set its backing_dev_info: the queue against which it should throttle) | |
5913 | */ | |
5914 | void __sched io_schedule(void) | |
5915 | { | |
70b97a7f | 5916 | struct rq *rq = &__raw_get_cpu_var(runqueues); |
1da177e4 | 5917 | |
0ff92245 | 5918 | delayacct_blkio_start(); |
1da177e4 LT |
5919 | atomic_inc(&rq->nr_iowait); |
5920 | schedule(); | |
5921 | atomic_dec(&rq->nr_iowait); | |
0ff92245 | 5922 | delayacct_blkio_end(); |
1da177e4 | 5923 | } |
1da177e4 LT |
5924 | EXPORT_SYMBOL(io_schedule); |
5925 | ||
5926 | long __sched io_schedule_timeout(long timeout) | |
5927 | { | |
70b97a7f | 5928 | struct rq *rq = &__raw_get_cpu_var(runqueues); |
1da177e4 LT |
5929 | long ret; |
5930 | ||
0ff92245 | 5931 | delayacct_blkio_start(); |
1da177e4 LT |
5932 | atomic_inc(&rq->nr_iowait); |
5933 | ret = schedule_timeout(timeout); | |
5934 | atomic_dec(&rq->nr_iowait); | |
0ff92245 | 5935 | delayacct_blkio_end(); |
1da177e4 LT |
5936 | return ret; |
5937 | } | |
5938 | ||
5939 | /** | |
5940 | * sys_sched_get_priority_max - return maximum RT priority. | |
5941 | * @policy: scheduling class. | |
5942 | * | |
5943 | * this syscall returns the maximum rt_priority that can be used | |
5944 | * by a given scheduling class. | |
5945 | */ | |
5add95d4 | 5946 | SYSCALL_DEFINE1(sched_get_priority_max, int, policy) |
1da177e4 LT |
5947 | { |
5948 | int ret = -EINVAL; | |
5949 | ||
5950 | switch (policy) { | |
5951 | case SCHED_FIFO: | |
5952 | case SCHED_RR: | |
5953 | ret = MAX_USER_RT_PRIO-1; | |
5954 | break; | |
5955 | case SCHED_NORMAL: | |
b0a9499c | 5956 | case SCHED_BATCH: |
dd41f596 | 5957 | case SCHED_IDLE: |
1da177e4 LT |
5958 | ret = 0; |
5959 | break; | |
5960 | } | |
5961 | return ret; | |
5962 | } | |
5963 | ||
5964 | /** | |
5965 | * sys_sched_get_priority_min - return minimum RT priority. | |
5966 | * @policy: scheduling class. | |
5967 | * | |
5968 | * this syscall returns the minimum rt_priority that can be used | |
5969 | * by a given scheduling class. | |
5970 | */ | |
5add95d4 | 5971 | SYSCALL_DEFINE1(sched_get_priority_min, int, policy) |
1da177e4 LT |
5972 | { |
5973 | int ret = -EINVAL; | |
5974 | ||
5975 | switch (policy) { | |
5976 | case SCHED_FIFO: | |
5977 | case SCHED_RR: | |
5978 | ret = 1; | |
5979 | break; | |
5980 | case SCHED_NORMAL: | |
b0a9499c | 5981 | case SCHED_BATCH: |
dd41f596 | 5982 | case SCHED_IDLE: |
1da177e4 LT |
5983 | ret = 0; |
5984 | } | |
5985 | return ret; | |
5986 | } | |
5987 | ||
5988 | /** | |
5989 | * sys_sched_rr_get_interval - return the default timeslice of a process. | |
5990 | * @pid: pid of the process. | |
5991 | * @interval: userspace pointer to the timeslice value. | |
5992 | * | |
5993 | * this syscall writes the default timeslice value of a given process | |
5994 | * into the user-space timespec buffer. A value of '0' means infinity. | |
5995 | */ | |
17da2bd9 | 5996 | SYSCALL_DEFINE2(sched_rr_get_interval, pid_t, pid, |
754fe8d2 | 5997 | struct timespec __user *, interval) |
1da177e4 | 5998 | { |
36c8b586 | 5999 | struct task_struct *p; |
a4ec24b4 | 6000 | unsigned int time_slice; |
3a5c359a | 6001 | int retval; |
1da177e4 | 6002 | struct timespec t; |
1da177e4 LT |
6003 | |
6004 | if (pid < 0) | |
3a5c359a | 6005 | return -EINVAL; |
1da177e4 LT |
6006 | |
6007 | retval = -ESRCH; | |
6008 | read_lock(&tasklist_lock); | |
6009 | p = find_process_by_pid(pid); | |
6010 | if (!p) | |
6011 | goto out_unlock; | |
6012 | ||
6013 | retval = security_task_getscheduler(p); | |
6014 | if (retval) | |
6015 | goto out_unlock; | |
6016 | ||
77034937 IM |
6017 | /* |
6018 | * Time slice is 0 for SCHED_FIFO tasks and for SCHED_OTHER | |
6019 | * tasks that are on an otherwise idle runqueue: | |
6020 | */ | |
6021 | time_slice = 0; | |
6022 | if (p->policy == SCHED_RR) { | |
a4ec24b4 | 6023 | time_slice = DEF_TIMESLICE; |
1868f958 | 6024 | } else if (p->policy != SCHED_FIFO) { |
a4ec24b4 DA |
6025 | struct sched_entity *se = &p->se; |
6026 | unsigned long flags; | |
6027 | struct rq *rq; | |
6028 | ||
6029 | rq = task_rq_lock(p, &flags); | |
77034937 IM |
6030 | if (rq->cfs.load.weight) |
6031 | time_slice = NS_TO_JIFFIES(sched_slice(&rq->cfs, se)); | |
a4ec24b4 DA |
6032 | task_rq_unlock(rq, &flags); |
6033 | } | |
1da177e4 | 6034 | read_unlock(&tasklist_lock); |
a4ec24b4 | 6035 | jiffies_to_timespec(time_slice, &t); |
1da177e4 | 6036 | retval = copy_to_user(interval, &t, sizeof(t)) ? -EFAULT : 0; |
1da177e4 | 6037 | return retval; |
3a5c359a | 6038 | |
1da177e4 LT |
6039 | out_unlock: |
6040 | read_unlock(&tasklist_lock); | |
6041 | return retval; | |
6042 | } | |
6043 | ||
7c731e0a | 6044 | static const char stat_nam[] = TASK_STATE_TO_CHAR_STR; |
36c8b586 | 6045 | |
82a1fcb9 | 6046 | void sched_show_task(struct task_struct *p) |
1da177e4 | 6047 | { |
1da177e4 | 6048 | unsigned long free = 0; |
36c8b586 | 6049 | unsigned state; |
1da177e4 | 6050 | |
1da177e4 | 6051 | state = p->state ? __ffs(p->state) + 1 : 0; |
cc4ea795 | 6052 | printk(KERN_INFO "%-13.13s %c", p->comm, |
2ed6e34f | 6053 | state < sizeof(stat_nam) - 1 ? stat_nam[state] : '?'); |
4bd77321 | 6054 | #if BITS_PER_LONG == 32 |
1da177e4 | 6055 | if (state == TASK_RUNNING) |
cc4ea795 | 6056 | printk(KERN_CONT " running "); |
1da177e4 | 6057 | else |
cc4ea795 | 6058 | printk(KERN_CONT " %08lx ", thread_saved_pc(p)); |
1da177e4 LT |
6059 | #else |
6060 | if (state == TASK_RUNNING) | |
cc4ea795 | 6061 | printk(KERN_CONT " running task "); |
1da177e4 | 6062 | else |
cc4ea795 | 6063 | printk(KERN_CONT " %016lx ", thread_saved_pc(p)); |
1da177e4 LT |
6064 | #endif |
6065 | #ifdef CONFIG_DEBUG_STACK_USAGE | |
6066 | { | |
10ebffde | 6067 | unsigned long *n = end_of_stack(p); |
1da177e4 LT |
6068 | while (!*n) |
6069 | n++; | |
10ebffde | 6070 | free = (unsigned long)n - (unsigned long)end_of_stack(p); |
1da177e4 LT |
6071 | } |
6072 | #endif | |
ba25f9dc | 6073 | printk(KERN_CONT "%5lu %5d %6d\n", free, |
fcfd50af | 6074 | task_pid_nr(p), task_pid_nr(p->real_parent)); |
1da177e4 | 6075 | |
5fb5e6de | 6076 | show_stack(p, NULL); |
1da177e4 LT |
6077 | } |
6078 | ||
e59e2ae2 | 6079 | void show_state_filter(unsigned long state_filter) |
1da177e4 | 6080 | { |
36c8b586 | 6081 | struct task_struct *g, *p; |
1da177e4 | 6082 | |
4bd77321 IM |
6083 | #if BITS_PER_LONG == 32 |
6084 | printk(KERN_INFO | |
6085 | " task PC stack pid father\n"); | |
1da177e4 | 6086 | #else |
4bd77321 IM |
6087 | printk(KERN_INFO |
6088 | " task PC stack pid father\n"); | |
1da177e4 LT |
6089 | #endif |
6090 | read_lock(&tasklist_lock); | |
6091 | do_each_thread(g, p) { | |
6092 | /* | |
6093 | * reset the NMI-timeout, listing all files on a slow | |
6094 | * console might take alot of time: | |
6095 | */ | |
6096 | touch_nmi_watchdog(); | |
39bc89fd | 6097 | if (!state_filter || (p->state & state_filter)) |
82a1fcb9 | 6098 | sched_show_task(p); |
1da177e4 LT |
6099 | } while_each_thread(g, p); |
6100 | ||
04c9167f JF |
6101 | touch_all_softlockup_watchdogs(); |
6102 | ||
dd41f596 IM |
6103 | #ifdef CONFIG_SCHED_DEBUG |
6104 | sysrq_sched_debug_show(); | |
6105 | #endif | |
1da177e4 | 6106 | read_unlock(&tasklist_lock); |
e59e2ae2 IM |
6107 | /* |
6108 | * Only show locks if all tasks are dumped: | |
6109 | */ | |
6110 | if (state_filter == -1) | |
6111 | debug_show_all_locks(); | |
1da177e4 LT |
6112 | } |
6113 | ||
1df21055 IM |
6114 | void __cpuinit init_idle_bootup_task(struct task_struct *idle) |
6115 | { | |
dd41f596 | 6116 | idle->sched_class = &idle_sched_class; |
1df21055 IM |
6117 | } |
6118 | ||
f340c0d1 IM |
6119 | /** |
6120 | * init_idle - set up an idle thread for a given CPU | |
6121 | * @idle: task in question | |
6122 | * @cpu: cpu the idle task belongs to | |
6123 | * | |
6124 | * NOTE: this function does not set the idle thread's NEED_RESCHED | |
6125 | * flag, to make booting more robust. | |
6126 | */ | |
5c1e1767 | 6127 | void __cpuinit init_idle(struct task_struct *idle, int cpu) |
1da177e4 | 6128 | { |
70b97a7f | 6129 | struct rq *rq = cpu_rq(cpu); |
1da177e4 LT |
6130 | unsigned long flags; |
6131 | ||
5cbd54ef IM |
6132 | spin_lock_irqsave(&rq->lock, flags); |
6133 | ||
dd41f596 IM |
6134 | __sched_fork(idle); |
6135 | idle->se.exec_start = sched_clock(); | |
6136 | ||
b29739f9 | 6137 | idle->prio = idle->normal_prio = MAX_PRIO; |
96f874e2 | 6138 | cpumask_copy(&idle->cpus_allowed, cpumask_of(cpu)); |
dd41f596 | 6139 | __set_task_cpu(idle, cpu); |
1da177e4 | 6140 | |
1da177e4 | 6141 | rq->curr = rq->idle = idle; |
4866cde0 NP |
6142 | #if defined(CONFIG_SMP) && defined(__ARCH_WANT_UNLOCKED_CTXSW) |
6143 | idle->oncpu = 1; | |
6144 | #endif | |
1da177e4 LT |
6145 | spin_unlock_irqrestore(&rq->lock, flags); |
6146 | ||
6147 | /* Set the preempt count _outside_ the spinlocks! */ | |
8e3e076c LT |
6148 | #if defined(CONFIG_PREEMPT) |
6149 | task_thread_info(idle)->preempt_count = (idle->lock_depth >= 0); | |
6150 | #else | |
a1261f54 | 6151 | task_thread_info(idle)->preempt_count = 0; |
8e3e076c | 6152 | #endif |
dd41f596 IM |
6153 | /* |
6154 | * The idle tasks have their own, simple scheduling class: | |
6155 | */ | |
6156 | idle->sched_class = &idle_sched_class; | |
fb52607a | 6157 | ftrace_graph_init_task(idle); |
1da177e4 LT |
6158 | } |
6159 | ||
6160 | /* | |
6161 | * In a system that switches off the HZ timer nohz_cpu_mask | |
6162 | * indicates which cpus entered this state. This is used | |
6163 | * in the rcu update to wait only for active cpus. For system | |
6164 | * which do not switch off the HZ timer nohz_cpu_mask should | |
6a7b3dc3 | 6165 | * always be CPU_BITS_NONE. |
1da177e4 | 6166 | */ |
6a7b3dc3 | 6167 | cpumask_var_t nohz_cpu_mask; |
1da177e4 | 6168 | |
19978ca6 IM |
6169 | /* |
6170 | * Increase the granularity value when there are more CPUs, | |
6171 | * because with more CPUs the 'effective latency' as visible | |
6172 | * to users decreases. But the relationship is not linear, | |
6173 | * so pick a second-best guess by going with the log2 of the | |
6174 | * number of CPUs. | |
6175 | * | |
6176 | * This idea comes from the SD scheduler of Con Kolivas: | |
6177 | */ | |
6178 | static inline void sched_init_granularity(void) | |
6179 | { | |
6180 | unsigned int factor = 1 + ilog2(num_online_cpus()); | |
6181 | const unsigned long limit = 200000000; | |
6182 | ||
6183 | sysctl_sched_min_granularity *= factor; | |
6184 | if (sysctl_sched_min_granularity > limit) | |
6185 | sysctl_sched_min_granularity = limit; | |
6186 | ||
6187 | sysctl_sched_latency *= factor; | |
6188 | if (sysctl_sched_latency > limit) | |
6189 | sysctl_sched_latency = limit; | |
6190 | ||
6191 | sysctl_sched_wakeup_granularity *= factor; | |
55cd5340 PZ |
6192 | |
6193 | sysctl_sched_shares_ratelimit *= factor; | |
19978ca6 IM |
6194 | } |
6195 | ||
1da177e4 LT |
6196 | #ifdef CONFIG_SMP |
6197 | /* | |
6198 | * This is how migration works: | |
6199 | * | |
70b97a7f | 6200 | * 1) we queue a struct migration_req structure in the source CPU's |
1da177e4 LT |
6201 | * runqueue and wake up that CPU's migration thread. |
6202 | * 2) we down() the locked semaphore => thread blocks. | |
6203 | * 3) migration thread wakes up (implicitly it forces the migrated | |
6204 | * thread off the CPU) | |
6205 | * 4) it gets the migration request and checks whether the migrated | |
6206 | * task is still in the wrong runqueue. | |
6207 | * 5) if it's in the wrong runqueue then the migration thread removes | |
6208 | * it and puts it into the right queue. | |
6209 | * 6) migration thread up()s the semaphore. | |
6210 | * 7) we wake up and the migration is done. | |
6211 | */ | |
6212 | ||
6213 | /* | |
6214 | * Change a given task's CPU affinity. Migrate the thread to a | |
6215 | * proper CPU and schedule it away if the CPU it's executing on | |
6216 | * is removed from the allowed bitmask. | |
6217 | * | |
6218 | * NOTE: the caller must have a valid reference to the task, the | |
41a2d6cf | 6219 | * task must not exit() & deallocate itself prematurely. The |
1da177e4 LT |
6220 | * call is not atomic; no spinlocks may be held. |
6221 | */ | |
96f874e2 | 6222 | int set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask) |
1da177e4 | 6223 | { |
70b97a7f | 6224 | struct migration_req req; |
1da177e4 | 6225 | unsigned long flags; |
70b97a7f | 6226 | struct rq *rq; |
48f24c4d | 6227 | int ret = 0; |
1da177e4 LT |
6228 | |
6229 | rq = task_rq_lock(p, &flags); | |
96f874e2 | 6230 | if (!cpumask_intersects(new_mask, cpu_online_mask)) { |
1da177e4 LT |
6231 | ret = -EINVAL; |
6232 | goto out; | |
6233 | } | |
6234 | ||
9985b0ba | 6235 | if (unlikely((p->flags & PF_THREAD_BOUND) && p != current && |
96f874e2 | 6236 | !cpumask_equal(&p->cpus_allowed, new_mask))) { |
9985b0ba DR |
6237 | ret = -EINVAL; |
6238 | goto out; | |
6239 | } | |
6240 | ||
73fe6aae | 6241 | if (p->sched_class->set_cpus_allowed) |
cd8ba7cd | 6242 | p->sched_class->set_cpus_allowed(p, new_mask); |
73fe6aae | 6243 | else { |
96f874e2 RR |
6244 | cpumask_copy(&p->cpus_allowed, new_mask); |
6245 | p->rt.nr_cpus_allowed = cpumask_weight(new_mask); | |
73fe6aae GH |
6246 | } |
6247 | ||
1da177e4 | 6248 | /* Can the task run on the task's current CPU? If so, we're done */ |
96f874e2 | 6249 | if (cpumask_test_cpu(task_cpu(p), new_mask)) |
1da177e4 LT |
6250 | goto out; |
6251 | ||
1e5ce4f4 | 6252 | if (migrate_task(p, cpumask_any_and(cpu_online_mask, new_mask), &req)) { |
1da177e4 LT |
6253 | /* Need help from migration thread: drop lock and wait. */ |
6254 | task_rq_unlock(rq, &flags); | |
6255 | wake_up_process(rq->migration_thread); | |
6256 | wait_for_completion(&req.done); | |
6257 | tlb_migrate_finish(p->mm); | |
6258 | return 0; | |
6259 | } | |
6260 | out: | |
6261 | task_rq_unlock(rq, &flags); | |
48f24c4d | 6262 | |
1da177e4 LT |
6263 | return ret; |
6264 | } | |
cd8ba7cd | 6265 | EXPORT_SYMBOL_GPL(set_cpus_allowed_ptr); |
1da177e4 LT |
6266 | |
6267 | /* | |
41a2d6cf | 6268 | * Move (not current) task off this cpu, onto dest cpu. We're doing |
1da177e4 LT |
6269 | * this because either it can't run here any more (set_cpus_allowed() |
6270 | * away from this CPU, or CPU going down), or because we're | |
6271 | * attempting to rebalance this task on exec (sched_exec). | |
6272 | * | |
6273 | * So we race with normal scheduler movements, but that's OK, as long | |
6274 | * as the task is no longer on this CPU. | |
efc30814 KK |
6275 | * |
6276 | * Returns non-zero if task was successfully migrated. | |
1da177e4 | 6277 | */ |
efc30814 | 6278 | static int __migrate_task(struct task_struct *p, int src_cpu, int dest_cpu) |
1da177e4 | 6279 | { |
70b97a7f | 6280 | struct rq *rq_dest, *rq_src; |
dd41f596 | 6281 | int ret = 0, on_rq; |
1da177e4 | 6282 | |
e761b772 | 6283 | if (unlikely(!cpu_active(dest_cpu))) |
efc30814 | 6284 | return ret; |
1da177e4 LT |
6285 | |
6286 | rq_src = cpu_rq(src_cpu); | |
6287 | rq_dest = cpu_rq(dest_cpu); | |
6288 | ||
6289 | double_rq_lock(rq_src, rq_dest); | |
6290 | /* Already moved. */ | |
6291 | if (task_cpu(p) != src_cpu) | |
b1e38734 | 6292 | goto done; |
1da177e4 | 6293 | /* Affinity changed (again). */ |
96f874e2 | 6294 | if (!cpumask_test_cpu(dest_cpu, &p->cpus_allowed)) |
b1e38734 | 6295 | goto fail; |
1da177e4 | 6296 | |
dd41f596 | 6297 | on_rq = p->se.on_rq; |
6e82a3be | 6298 | if (on_rq) |
2e1cb74a | 6299 | deactivate_task(rq_src, p, 0); |
6e82a3be | 6300 | |
1da177e4 | 6301 | set_task_cpu(p, dest_cpu); |
dd41f596 IM |
6302 | if (on_rq) { |
6303 | activate_task(rq_dest, p, 0); | |
15afe09b | 6304 | check_preempt_curr(rq_dest, p, 0); |
1da177e4 | 6305 | } |
b1e38734 | 6306 | done: |
efc30814 | 6307 | ret = 1; |
b1e38734 | 6308 | fail: |
1da177e4 | 6309 | double_rq_unlock(rq_src, rq_dest); |
efc30814 | 6310 | return ret; |
1da177e4 LT |
6311 | } |
6312 | ||
6313 | /* | |
6314 | * migration_thread - this is a highprio system thread that performs | |
6315 | * thread migration by bumping thread off CPU then 'pushing' onto | |
6316 | * another runqueue. | |
6317 | */ | |
95cdf3b7 | 6318 | static int migration_thread(void *data) |
1da177e4 | 6319 | { |
1da177e4 | 6320 | int cpu = (long)data; |
70b97a7f | 6321 | struct rq *rq; |
1da177e4 LT |
6322 | |
6323 | rq = cpu_rq(cpu); | |
6324 | BUG_ON(rq->migration_thread != current); | |
6325 | ||
6326 | set_current_state(TASK_INTERRUPTIBLE); | |
6327 | while (!kthread_should_stop()) { | |
70b97a7f | 6328 | struct migration_req *req; |
1da177e4 | 6329 | struct list_head *head; |
1da177e4 | 6330 | |
1da177e4 LT |
6331 | spin_lock_irq(&rq->lock); |
6332 | ||
6333 | if (cpu_is_offline(cpu)) { | |
6334 | spin_unlock_irq(&rq->lock); | |
6335 | goto wait_to_die; | |
6336 | } | |
6337 | ||
6338 | if (rq->active_balance) { | |
6339 | active_load_balance(rq, cpu); | |
6340 | rq->active_balance = 0; | |
6341 | } | |
6342 | ||
6343 | head = &rq->migration_queue; | |
6344 | ||
6345 | if (list_empty(head)) { | |
6346 | spin_unlock_irq(&rq->lock); | |
6347 | schedule(); | |
6348 | set_current_state(TASK_INTERRUPTIBLE); | |
6349 | continue; | |
6350 | } | |
70b97a7f | 6351 | req = list_entry(head->next, struct migration_req, list); |
1da177e4 LT |
6352 | list_del_init(head->next); |
6353 | ||
674311d5 NP |
6354 | spin_unlock(&rq->lock); |
6355 | __migrate_task(req->task, cpu, req->dest_cpu); | |
6356 | local_irq_enable(); | |
1da177e4 LT |
6357 | |
6358 | complete(&req->done); | |
6359 | } | |
6360 | __set_current_state(TASK_RUNNING); | |
6361 | return 0; | |
6362 | ||
6363 | wait_to_die: | |
6364 | /* Wait for kthread_stop */ | |
6365 | set_current_state(TASK_INTERRUPTIBLE); | |
6366 | while (!kthread_should_stop()) { | |
6367 | schedule(); | |
6368 | set_current_state(TASK_INTERRUPTIBLE); | |
6369 | } | |
6370 | __set_current_state(TASK_RUNNING); | |
6371 | return 0; | |
6372 | } | |
6373 | ||
6374 | #ifdef CONFIG_HOTPLUG_CPU | |
f7b4cddc ON |
6375 | |
6376 | static int __migrate_task_irq(struct task_struct *p, int src_cpu, int dest_cpu) | |
6377 | { | |
6378 | int ret; | |
6379 | ||
6380 | local_irq_disable(); | |
6381 | ret = __migrate_task(p, src_cpu, dest_cpu); | |
6382 | local_irq_enable(); | |
6383 | return ret; | |
6384 | } | |
6385 | ||
054b9108 | 6386 | /* |
3a4fa0a2 | 6387 | * Figure out where task on dead CPU should go, use force if necessary. |
054b9108 | 6388 | */ |
48f24c4d | 6389 | static void move_task_off_dead_cpu(int dead_cpu, struct task_struct *p) |
1da177e4 | 6390 | { |
70b97a7f | 6391 | int dest_cpu; |
6ca09dfc | 6392 | const struct cpumask *nodemask = cpumask_of_node(cpu_to_node(dead_cpu)); |
e76bd8d9 RR |
6393 | |
6394 | again: | |
6395 | /* Look for allowed, online CPU in same node. */ | |
6396 | for_each_cpu_and(dest_cpu, nodemask, cpu_online_mask) | |
6397 | if (cpumask_test_cpu(dest_cpu, &p->cpus_allowed)) | |
6398 | goto move; | |
6399 | ||
6400 | /* Any allowed, online CPU? */ | |
6401 | dest_cpu = cpumask_any_and(&p->cpus_allowed, cpu_online_mask); | |
6402 | if (dest_cpu < nr_cpu_ids) | |
6403 | goto move; | |
6404 | ||
6405 | /* No more Mr. Nice Guy. */ | |
6406 | if (dest_cpu >= nr_cpu_ids) { | |
e76bd8d9 RR |
6407 | cpuset_cpus_allowed_locked(p, &p->cpus_allowed); |
6408 | dest_cpu = cpumask_any_and(cpu_online_mask, &p->cpus_allowed); | |
1da177e4 | 6409 | |
e76bd8d9 RR |
6410 | /* |
6411 | * Don't tell them about moving exiting tasks or | |
6412 | * kernel threads (both mm NULL), since they never | |
6413 | * leave kernel. | |
6414 | */ | |
6415 | if (p->mm && printk_ratelimit()) { | |
6416 | printk(KERN_INFO "process %d (%s) no " | |
6417 | "longer affine to cpu%d\n", | |
6418 | task_pid_nr(p), p->comm, dead_cpu); | |
3a5c359a | 6419 | } |
e76bd8d9 RR |
6420 | } |
6421 | ||
6422 | move: | |
6423 | /* It can have affinity changed while we were choosing. */ | |
6424 | if (unlikely(!__migrate_task_irq(p, dead_cpu, dest_cpu))) | |
6425 | goto again; | |
1da177e4 LT |
6426 | } |
6427 | ||
6428 | /* | |
6429 | * While a dead CPU has no uninterruptible tasks queued at this point, | |
6430 | * it might still have a nonzero ->nr_uninterruptible counter, because | |
6431 | * for performance reasons the counter is not stricly tracking tasks to | |
6432 | * their home CPUs. So we just add the counter to another CPU's counter, | |
6433 | * to keep the global sum constant after CPU-down: | |
6434 | */ | |
70b97a7f | 6435 | static void migrate_nr_uninterruptible(struct rq *rq_src) |
1da177e4 | 6436 | { |
1e5ce4f4 | 6437 | struct rq *rq_dest = cpu_rq(cpumask_any(cpu_online_mask)); |
1da177e4 LT |
6438 | unsigned long flags; |
6439 | ||
6440 | local_irq_save(flags); | |
6441 | double_rq_lock(rq_src, rq_dest); | |
6442 | rq_dest->nr_uninterruptible += rq_src->nr_uninterruptible; | |
6443 | rq_src->nr_uninterruptible = 0; | |
6444 | double_rq_unlock(rq_src, rq_dest); | |
6445 | local_irq_restore(flags); | |
6446 | } | |
6447 | ||
6448 | /* Run through task list and migrate tasks from the dead cpu. */ | |
6449 | static void migrate_live_tasks(int src_cpu) | |
6450 | { | |
48f24c4d | 6451 | struct task_struct *p, *t; |
1da177e4 | 6452 | |
f7b4cddc | 6453 | read_lock(&tasklist_lock); |
1da177e4 | 6454 | |
48f24c4d IM |
6455 | do_each_thread(t, p) { |
6456 | if (p == current) | |
1da177e4 LT |
6457 | continue; |
6458 | ||
48f24c4d IM |
6459 | if (task_cpu(p) == src_cpu) |
6460 | move_task_off_dead_cpu(src_cpu, p); | |
6461 | } while_each_thread(t, p); | |
1da177e4 | 6462 | |
f7b4cddc | 6463 | read_unlock(&tasklist_lock); |
1da177e4 LT |
6464 | } |
6465 | ||
dd41f596 IM |
6466 | /* |
6467 | * Schedules idle task to be the next runnable task on current CPU. | |
94bc9a7b DA |
6468 | * It does so by boosting its priority to highest possible. |
6469 | * Used by CPU offline code. | |
1da177e4 LT |
6470 | */ |
6471 | void sched_idle_next(void) | |
6472 | { | |
48f24c4d | 6473 | int this_cpu = smp_processor_id(); |
70b97a7f | 6474 | struct rq *rq = cpu_rq(this_cpu); |
1da177e4 LT |
6475 | struct task_struct *p = rq->idle; |
6476 | unsigned long flags; | |
6477 | ||
6478 | /* cpu has to be offline */ | |
48f24c4d | 6479 | BUG_ON(cpu_online(this_cpu)); |
1da177e4 | 6480 | |
48f24c4d IM |
6481 | /* |
6482 | * Strictly not necessary since rest of the CPUs are stopped by now | |
6483 | * and interrupts disabled on the current cpu. | |
1da177e4 LT |
6484 | */ |
6485 | spin_lock_irqsave(&rq->lock, flags); | |
6486 | ||
dd41f596 | 6487 | __setscheduler(rq, p, SCHED_FIFO, MAX_RT_PRIO-1); |
48f24c4d | 6488 | |
94bc9a7b DA |
6489 | update_rq_clock(rq); |
6490 | activate_task(rq, p, 0); | |
1da177e4 LT |
6491 | |
6492 | spin_unlock_irqrestore(&rq->lock, flags); | |
6493 | } | |
6494 | ||
48f24c4d IM |
6495 | /* |
6496 | * Ensures that the idle task is using init_mm right before its cpu goes | |
1da177e4 LT |
6497 | * offline. |
6498 | */ | |
6499 | void idle_task_exit(void) | |
6500 | { | |
6501 | struct mm_struct *mm = current->active_mm; | |
6502 | ||
6503 | BUG_ON(cpu_online(smp_processor_id())); | |
6504 | ||
6505 | if (mm != &init_mm) | |
6506 | switch_mm(mm, &init_mm, current); | |
6507 | mmdrop(mm); | |
6508 | } | |
6509 | ||
054b9108 | 6510 | /* called under rq->lock with disabled interrupts */ |
36c8b586 | 6511 | static void migrate_dead(unsigned int dead_cpu, struct task_struct *p) |
1da177e4 | 6512 | { |
70b97a7f | 6513 | struct rq *rq = cpu_rq(dead_cpu); |
1da177e4 LT |
6514 | |
6515 | /* Must be exiting, otherwise would be on tasklist. */ | |
270f722d | 6516 | BUG_ON(!p->exit_state); |
1da177e4 LT |
6517 | |
6518 | /* Cannot have done final schedule yet: would have vanished. */ | |
c394cc9f | 6519 | BUG_ON(p->state == TASK_DEAD); |
1da177e4 | 6520 | |
48f24c4d | 6521 | get_task_struct(p); |
1da177e4 LT |
6522 | |
6523 | /* | |
6524 | * Drop lock around migration; if someone else moves it, | |
41a2d6cf | 6525 | * that's OK. No task can be added to this CPU, so iteration is |
1da177e4 LT |
6526 | * fine. |
6527 | */ | |
f7b4cddc | 6528 | spin_unlock_irq(&rq->lock); |
48f24c4d | 6529 | move_task_off_dead_cpu(dead_cpu, p); |
f7b4cddc | 6530 | spin_lock_irq(&rq->lock); |
1da177e4 | 6531 | |
48f24c4d | 6532 | put_task_struct(p); |
1da177e4 LT |
6533 | } |
6534 | ||
6535 | /* release_task() removes task from tasklist, so we won't find dead tasks. */ | |
6536 | static void migrate_dead_tasks(unsigned int dead_cpu) | |
6537 | { | |
70b97a7f | 6538 | struct rq *rq = cpu_rq(dead_cpu); |
dd41f596 | 6539 | struct task_struct *next; |
48f24c4d | 6540 | |
dd41f596 IM |
6541 | for ( ; ; ) { |
6542 | if (!rq->nr_running) | |
6543 | break; | |
a8e504d2 | 6544 | update_rq_clock(rq); |
ff95f3df | 6545 | next = pick_next_task(rq, rq->curr); |
dd41f596 IM |
6546 | if (!next) |
6547 | break; | |
79c53799 | 6548 | next->sched_class->put_prev_task(rq, next); |
dd41f596 | 6549 | migrate_dead(dead_cpu, next); |
e692ab53 | 6550 | |
1da177e4 LT |
6551 | } |
6552 | } | |
6553 | #endif /* CONFIG_HOTPLUG_CPU */ | |
6554 | ||
e692ab53 NP |
6555 | #if defined(CONFIG_SCHED_DEBUG) && defined(CONFIG_SYSCTL) |
6556 | ||
6557 | static struct ctl_table sd_ctl_dir[] = { | |
e0361851 AD |
6558 | { |
6559 | .procname = "sched_domain", | |
c57baf1e | 6560 | .mode = 0555, |
e0361851 | 6561 | }, |
38605cae | 6562 | {0, }, |
e692ab53 NP |
6563 | }; |
6564 | ||
6565 | static struct ctl_table sd_ctl_root[] = { | |
e0361851 | 6566 | { |
c57baf1e | 6567 | .ctl_name = CTL_KERN, |
e0361851 | 6568 | .procname = "kernel", |
c57baf1e | 6569 | .mode = 0555, |
e0361851 AD |
6570 | .child = sd_ctl_dir, |
6571 | }, | |
38605cae | 6572 | {0, }, |
e692ab53 NP |
6573 | }; |
6574 | ||
6575 | static struct ctl_table *sd_alloc_ctl_entry(int n) | |
6576 | { | |
6577 | struct ctl_table *entry = | |
5cf9f062 | 6578 | kcalloc(n, sizeof(struct ctl_table), GFP_KERNEL); |
e692ab53 | 6579 | |
e692ab53 NP |
6580 | return entry; |
6581 | } | |
6582 | ||
6382bc90 MM |
6583 | static void sd_free_ctl_entry(struct ctl_table **tablep) |
6584 | { | |
cd790076 | 6585 | struct ctl_table *entry; |
6382bc90 | 6586 | |
cd790076 MM |
6587 | /* |
6588 | * In the intermediate directories, both the child directory and | |
6589 | * procname are dynamically allocated and could fail but the mode | |
41a2d6cf | 6590 | * will always be set. In the lowest directory the names are |
cd790076 MM |
6591 | * static strings and all have proc handlers. |
6592 | */ | |
6593 | for (entry = *tablep; entry->mode; entry++) { | |
6382bc90 MM |
6594 | if (entry->child) |
6595 | sd_free_ctl_entry(&entry->child); | |
cd790076 MM |
6596 | if (entry->proc_handler == NULL) |
6597 | kfree(entry->procname); | |
6598 | } | |
6382bc90 MM |
6599 | |
6600 | kfree(*tablep); | |
6601 | *tablep = NULL; | |
6602 | } | |
6603 | ||
e692ab53 | 6604 | static void |
e0361851 | 6605 | set_table_entry(struct ctl_table *entry, |
e692ab53 NP |
6606 | const char *procname, void *data, int maxlen, |
6607 | mode_t mode, proc_handler *proc_handler) | |
6608 | { | |
e692ab53 NP |
6609 | entry->procname = procname; |
6610 | entry->data = data; | |
6611 | entry->maxlen = maxlen; | |
6612 | entry->mode = mode; | |
6613 | entry->proc_handler = proc_handler; | |
6614 | } | |
6615 | ||
6616 | static struct ctl_table * | |
6617 | sd_alloc_ctl_domain_table(struct sched_domain *sd) | |
6618 | { | |
a5d8c348 | 6619 | struct ctl_table *table = sd_alloc_ctl_entry(13); |
e692ab53 | 6620 | |
ad1cdc1d MM |
6621 | if (table == NULL) |
6622 | return NULL; | |
6623 | ||
e0361851 | 6624 | set_table_entry(&table[0], "min_interval", &sd->min_interval, |
e692ab53 | 6625 | sizeof(long), 0644, proc_doulongvec_minmax); |
e0361851 | 6626 | set_table_entry(&table[1], "max_interval", &sd->max_interval, |
e692ab53 | 6627 | sizeof(long), 0644, proc_doulongvec_minmax); |
e0361851 | 6628 | set_table_entry(&table[2], "busy_idx", &sd->busy_idx, |
e692ab53 | 6629 | sizeof(int), 0644, proc_dointvec_minmax); |
e0361851 | 6630 | set_table_entry(&table[3], "idle_idx", &sd->idle_idx, |
e692ab53 | 6631 | sizeof(int), 0644, proc_dointvec_minmax); |
e0361851 | 6632 | set_table_entry(&table[4], "newidle_idx", &sd->newidle_idx, |
e692ab53 | 6633 | sizeof(int), 0644, proc_dointvec_minmax); |
e0361851 | 6634 | set_table_entry(&table[5], "wake_idx", &sd->wake_idx, |
e692ab53 | 6635 | sizeof(int), 0644, proc_dointvec_minmax); |
e0361851 | 6636 | set_table_entry(&table[6], "forkexec_idx", &sd->forkexec_idx, |
e692ab53 | 6637 | sizeof(int), 0644, proc_dointvec_minmax); |
e0361851 | 6638 | set_table_entry(&table[7], "busy_factor", &sd->busy_factor, |
e692ab53 | 6639 | sizeof(int), 0644, proc_dointvec_minmax); |
e0361851 | 6640 | set_table_entry(&table[8], "imbalance_pct", &sd->imbalance_pct, |
e692ab53 | 6641 | sizeof(int), 0644, proc_dointvec_minmax); |
ace8b3d6 | 6642 | set_table_entry(&table[9], "cache_nice_tries", |
e692ab53 NP |
6643 | &sd->cache_nice_tries, |
6644 | sizeof(int), 0644, proc_dointvec_minmax); | |
ace8b3d6 | 6645 | set_table_entry(&table[10], "flags", &sd->flags, |
e692ab53 | 6646 | sizeof(int), 0644, proc_dointvec_minmax); |
a5d8c348 IM |
6647 | set_table_entry(&table[11], "name", sd->name, |
6648 | CORENAME_MAX_SIZE, 0444, proc_dostring); | |
6649 | /* &table[12] is terminator */ | |
e692ab53 NP |
6650 | |
6651 | return table; | |
6652 | } | |
6653 | ||
9a4e7159 | 6654 | static ctl_table *sd_alloc_ctl_cpu_table(int cpu) |
e692ab53 NP |
6655 | { |
6656 | struct ctl_table *entry, *table; | |
6657 | struct sched_domain *sd; | |
6658 | int domain_num = 0, i; | |
6659 | char buf[32]; | |
6660 | ||
6661 | for_each_domain(cpu, sd) | |
6662 | domain_num++; | |
6663 | entry = table = sd_alloc_ctl_entry(domain_num + 1); | |
ad1cdc1d MM |
6664 | if (table == NULL) |
6665 | return NULL; | |
e692ab53 NP |
6666 | |
6667 | i = 0; | |
6668 | for_each_domain(cpu, sd) { | |
6669 | snprintf(buf, 32, "domain%d", i); | |
e692ab53 | 6670 | entry->procname = kstrdup(buf, GFP_KERNEL); |
c57baf1e | 6671 | entry->mode = 0555; |
e692ab53 NP |
6672 | entry->child = sd_alloc_ctl_domain_table(sd); |
6673 | entry++; | |
6674 | i++; | |
6675 | } | |
6676 | return table; | |
6677 | } | |
6678 | ||
6679 | static struct ctl_table_header *sd_sysctl_header; | |
6382bc90 | 6680 | static void register_sched_domain_sysctl(void) |
e692ab53 NP |
6681 | { |
6682 | int i, cpu_num = num_online_cpus(); | |
6683 | struct ctl_table *entry = sd_alloc_ctl_entry(cpu_num + 1); | |
6684 | char buf[32]; | |
6685 | ||
7378547f MM |
6686 | WARN_ON(sd_ctl_dir[0].child); |
6687 | sd_ctl_dir[0].child = entry; | |
6688 | ||
ad1cdc1d MM |
6689 | if (entry == NULL) |
6690 | return; | |
6691 | ||
97b6ea7b | 6692 | for_each_online_cpu(i) { |
e692ab53 | 6693 | snprintf(buf, 32, "cpu%d", i); |
e692ab53 | 6694 | entry->procname = kstrdup(buf, GFP_KERNEL); |
c57baf1e | 6695 | entry->mode = 0555; |
e692ab53 | 6696 | entry->child = sd_alloc_ctl_cpu_table(i); |
97b6ea7b | 6697 | entry++; |
e692ab53 | 6698 | } |
7378547f MM |
6699 | |
6700 | WARN_ON(sd_sysctl_header); | |
e692ab53 NP |
6701 | sd_sysctl_header = register_sysctl_table(sd_ctl_root); |
6702 | } | |
6382bc90 | 6703 | |
7378547f | 6704 | /* may be called multiple times per register */ |
6382bc90 MM |
6705 | static void unregister_sched_domain_sysctl(void) |
6706 | { | |
7378547f MM |
6707 | if (sd_sysctl_header) |
6708 | unregister_sysctl_table(sd_sysctl_header); | |
6382bc90 | 6709 | sd_sysctl_header = NULL; |
7378547f MM |
6710 | if (sd_ctl_dir[0].child) |
6711 | sd_free_ctl_entry(&sd_ctl_dir[0].child); | |
6382bc90 | 6712 | } |
e692ab53 | 6713 | #else |
6382bc90 MM |
6714 | static void register_sched_domain_sysctl(void) |
6715 | { | |
6716 | } | |
6717 | static void unregister_sched_domain_sysctl(void) | |
e692ab53 NP |
6718 | { |
6719 | } | |
6720 | #endif | |
6721 | ||
1f11eb6a GH |
6722 | static void set_rq_online(struct rq *rq) |
6723 | { | |
6724 | if (!rq->online) { | |
6725 | const struct sched_class *class; | |
6726 | ||
c6c4927b | 6727 | cpumask_set_cpu(rq->cpu, rq->rd->online); |
1f11eb6a GH |
6728 | rq->online = 1; |
6729 | ||
6730 | for_each_class(class) { | |
6731 | if (class->rq_online) | |
6732 | class->rq_online(rq); | |
6733 | } | |
6734 | } | |
6735 | } | |
6736 | ||
6737 | static void set_rq_offline(struct rq *rq) | |
6738 | { | |
6739 | if (rq->online) { | |
6740 | const struct sched_class *class; | |
6741 | ||
6742 | for_each_class(class) { | |
6743 | if (class->rq_offline) | |
6744 | class->rq_offline(rq); | |
6745 | } | |
6746 | ||
c6c4927b | 6747 | cpumask_clear_cpu(rq->cpu, rq->rd->online); |
1f11eb6a GH |
6748 | rq->online = 0; |
6749 | } | |
6750 | } | |
6751 | ||
1da177e4 LT |
6752 | /* |
6753 | * migration_call - callback that gets triggered when a CPU is added. | |
6754 | * Here we can start up the necessary migration thread for the new CPU. | |
6755 | */ | |
48f24c4d IM |
6756 | static int __cpuinit |
6757 | migration_call(struct notifier_block *nfb, unsigned long action, void *hcpu) | |
1da177e4 | 6758 | { |
1da177e4 | 6759 | struct task_struct *p; |
48f24c4d | 6760 | int cpu = (long)hcpu; |
1da177e4 | 6761 | unsigned long flags; |
70b97a7f | 6762 | struct rq *rq; |
1da177e4 LT |
6763 | |
6764 | switch (action) { | |
5be9361c | 6765 | |
1da177e4 | 6766 | case CPU_UP_PREPARE: |
8bb78442 | 6767 | case CPU_UP_PREPARE_FROZEN: |
dd41f596 | 6768 | p = kthread_create(migration_thread, hcpu, "migration/%d", cpu); |
1da177e4 LT |
6769 | if (IS_ERR(p)) |
6770 | return NOTIFY_BAD; | |
1da177e4 LT |
6771 | kthread_bind(p, cpu); |
6772 | /* Must be high prio: stop_machine expects to yield to it. */ | |
6773 | rq = task_rq_lock(p, &flags); | |
dd41f596 | 6774 | __setscheduler(rq, p, SCHED_FIFO, MAX_RT_PRIO-1); |
1da177e4 LT |
6775 | task_rq_unlock(rq, &flags); |
6776 | cpu_rq(cpu)->migration_thread = p; | |
6777 | break; | |
48f24c4d | 6778 | |
1da177e4 | 6779 | case CPU_ONLINE: |
8bb78442 | 6780 | case CPU_ONLINE_FROZEN: |
3a4fa0a2 | 6781 | /* Strictly unnecessary, as first user will wake it. */ |
1da177e4 | 6782 | wake_up_process(cpu_rq(cpu)->migration_thread); |
1f94ef59 GH |
6783 | |
6784 | /* Update our root-domain */ | |
6785 | rq = cpu_rq(cpu); | |
6786 | spin_lock_irqsave(&rq->lock, flags); | |
6787 | if (rq->rd) { | |
c6c4927b | 6788 | BUG_ON(!cpumask_test_cpu(cpu, rq->rd->span)); |
1f11eb6a GH |
6789 | |
6790 | set_rq_online(rq); | |
1f94ef59 GH |
6791 | } |
6792 | spin_unlock_irqrestore(&rq->lock, flags); | |
1da177e4 | 6793 | break; |
48f24c4d | 6794 | |
1da177e4 LT |
6795 | #ifdef CONFIG_HOTPLUG_CPU |
6796 | case CPU_UP_CANCELED: | |
8bb78442 | 6797 | case CPU_UP_CANCELED_FROZEN: |
fc75cdfa HC |
6798 | if (!cpu_rq(cpu)->migration_thread) |
6799 | break; | |
41a2d6cf | 6800 | /* Unbind it from offline cpu so it can run. Fall thru. */ |
a4c4af7c | 6801 | kthread_bind(cpu_rq(cpu)->migration_thread, |
1e5ce4f4 | 6802 | cpumask_any(cpu_online_mask)); |
1da177e4 LT |
6803 | kthread_stop(cpu_rq(cpu)->migration_thread); |
6804 | cpu_rq(cpu)->migration_thread = NULL; | |
6805 | break; | |
48f24c4d | 6806 | |
1da177e4 | 6807 | case CPU_DEAD: |
8bb78442 | 6808 | case CPU_DEAD_FROZEN: |
470fd646 | 6809 | cpuset_lock(); /* around calls to cpuset_cpus_allowed_lock() */ |
1da177e4 LT |
6810 | migrate_live_tasks(cpu); |
6811 | rq = cpu_rq(cpu); | |
6812 | kthread_stop(rq->migration_thread); | |
6813 | rq->migration_thread = NULL; | |
6814 | /* Idle task back to normal (off runqueue, low prio) */ | |
d2da272a | 6815 | spin_lock_irq(&rq->lock); |
a8e504d2 | 6816 | update_rq_clock(rq); |
2e1cb74a | 6817 | deactivate_task(rq, rq->idle, 0); |
1da177e4 | 6818 | rq->idle->static_prio = MAX_PRIO; |
dd41f596 IM |
6819 | __setscheduler(rq, rq->idle, SCHED_NORMAL, 0); |
6820 | rq->idle->sched_class = &idle_sched_class; | |
1da177e4 | 6821 | migrate_dead_tasks(cpu); |
d2da272a | 6822 | spin_unlock_irq(&rq->lock); |
470fd646 | 6823 | cpuset_unlock(); |
1da177e4 LT |
6824 | migrate_nr_uninterruptible(rq); |
6825 | BUG_ON(rq->nr_running != 0); | |
6826 | ||
41a2d6cf IM |
6827 | /* |
6828 | * No need to migrate the tasks: it was best-effort if | |
6829 | * they didn't take sched_hotcpu_mutex. Just wake up | |
6830 | * the requestors. | |
6831 | */ | |
1da177e4 LT |
6832 | spin_lock_irq(&rq->lock); |
6833 | while (!list_empty(&rq->migration_queue)) { | |
70b97a7f IM |
6834 | struct migration_req *req; |
6835 | ||
1da177e4 | 6836 | req = list_entry(rq->migration_queue.next, |
70b97a7f | 6837 | struct migration_req, list); |
1da177e4 | 6838 | list_del_init(&req->list); |
9a2bd244 | 6839 | spin_unlock_irq(&rq->lock); |
1da177e4 | 6840 | complete(&req->done); |
9a2bd244 | 6841 | spin_lock_irq(&rq->lock); |
1da177e4 LT |
6842 | } |
6843 | spin_unlock_irq(&rq->lock); | |
6844 | break; | |
57d885fe | 6845 | |
08f503b0 GH |
6846 | case CPU_DYING: |
6847 | case CPU_DYING_FROZEN: | |
57d885fe GH |
6848 | /* Update our root-domain */ |
6849 | rq = cpu_rq(cpu); | |
6850 | spin_lock_irqsave(&rq->lock, flags); | |
6851 | if (rq->rd) { | |
c6c4927b | 6852 | BUG_ON(!cpumask_test_cpu(cpu, rq->rd->span)); |
1f11eb6a | 6853 | set_rq_offline(rq); |
57d885fe GH |
6854 | } |
6855 | spin_unlock_irqrestore(&rq->lock, flags); | |
6856 | break; | |
1da177e4 LT |
6857 | #endif |
6858 | } | |
6859 | return NOTIFY_OK; | |
6860 | } | |
6861 | ||
6862 | /* Register at highest priority so that task migration (migrate_all_tasks) | |
6863 | * happens before everything else. | |
6864 | */ | |
26c2143b | 6865 | static struct notifier_block __cpuinitdata migration_notifier = { |
1da177e4 LT |
6866 | .notifier_call = migration_call, |
6867 | .priority = 10 | |
6868 | }; | |
6869 | ||
7babe8db | 6870 | static int __init migration_init(void) |
1da177e4 LT |
6871 | { |
6872 | void *cpu = (void *)(long)smp_processor_id(); | |
07dccf33 | 6873 | int err; |
48f24c4d IM |
6874 | |
6875 | /* Start one for the boot CPU: */ | |
07dccf33 AM |
6876 | err = migration_call(&migration_notifier, CPU_UP_PREPARE, cpu); |
6877 | BUG_ON(err == NOTIFY_BAD); | |
1da177e4 LT |
6878 | migration_call(&migration_notifier, CPU_ONLINE, cpu); |
6879 | register_cpu_notifier(&migration_notifier); | |
7babe8db EGM |
6880 | |
6881 | return err; | |
1da177e4 | 6882 | } |
7babe8db | 6883 | early_initcall(migration_init); |
1da177e4 LT |
6884 | #endif |
6885 | ||
6886 | #ifdef CONFIG_SMP | |
476f3534 | 6887 | |
3e9830dc | 6888 | #ifdef CONFIG_SCHED_DEBUG |
4dcf6aff | 6889 | |
7c16ec58 | 6890 | static int sched_domain_debug_one(struct sched_domain *sd, int cpu, int level, |
96f874e2 | 6891 | struct cpumask *groupmask) |
1da177e4 | 6892 | { |
4dcf6aff | 6893 | struct sched_group *group = sd->groups; |
434d53b0 | 6894 | char str[256]; |
1da177e4 | 6895 | |
968ea6d8 | 6896 | cpulist_scnprintf(str, sizeof(str), sched_domain_span(sd)); |
96f874e2 | 6897 | cpumask_clear(groupmask); |
4dcf6aff IM |
6898 | |
6899 | printk(KERN_DEBUG "%*s domain %d: ", level, "", level); | |
6900 | ||
6901 | if (!(sd->flags & SD_LOAD_BALANCE)) { | |
6902 | printk("does not load-balance\n"); | |
6903 | if (sd->parent) | |
6904 | printk(KERN_ERR "ERROR: !SD_LOAD_BALANCE domain" | |
6905 | " has parent"); | |
6906 | return -1; | |
41c7ce9a NP |
6907 | } |
6908 | ||
eefd796a | 6909 | printk(KERN_CONT "span %s level %s\n", str, sd->name); |
4dcf6aff | 6910 | |
758b2cdc | 6911 | if (!cpumask_test_cpu(cpu, sched_domain_span(sd))) { |
4dcf6aff IM |
6912 | printk(KERN_ERR "ERROR: domain->span does not contain " |
6913 | "CPU%d\n", cpu); | |
6914 | } | |
758b2cdc | 6915 | if (!cpumask_test_cpu(cpu, sched_group_cpus(group))) { |
4dcf6aff IM |
6916 | printk(KERN_ERR "ERROR: domain->groups does not contain" |
6917 | " CPU%d\n", cpu); | |
6918 | } | |
1da177e4 | 6919 | |
4dcf6aff | 6920 | printk(KERN_DEBUG "%*s groups:", level + 1, ""); |
1da177e4 | 6921 | do { |
4dcf6aff IM |
6922 | if (!group) { |
6923 | printk("\n"); | |
6924 | printk(KERN_ERR "ERROR: group is NULL\n"); | |
1da177e4 LT |
6925 | break; |
6926 | } | |
6927 | ||
4dcf6aff IM |
6928 | if (!group->__cpu_power) { |
6929 | printk(KERN_CONT "\n"); | |
6930 | printk(KERN_ERR "ERROR: domain->cpu_power not " | |
6931 | "set\n"); | |
6932 | break; | |
6933 | } | |
1da177e4 | 6934 | |
758b2cdc | 6935 | if (!cpumask_weight(sched_group_cpus(group))) { |
4dcf6aff IM |
6936 | printk(KERN_CONT "\n"); |
6937 | printk(KERN_ERR "ERROR: empty group\n"); | |
6938 | break; | |
6939 | } | |
1da177e4 | 6940 | |
758b2cdc | 6941 | if (cpumask_intersects(groupmask, sched_group_cpus(group))) { |
4dcf6aff IM |
6942 | printk(KERN_CONT "\n"); |
6943 | printk(KERN_ERR "ERROR: repeated CPUs\n"); | |
6944 | break; | |
6945 | } | |
1da177e4 | 6946 | |
758b2cdc | 6947 | cpumask_or(groupmask, groupmask, sched_group_cpus(group)); |
1da177e4 | 6948 | |
968ea6d8 | 6949 | cpulist_scnprintf(str, sizeof(str), sched_group_cpus(group)); |
4dcf6aff | 6950 | printk(KERN_CONT " %s", str); |
1da177e4 | 6951 | |
4dcf6aff IM |
6952 | group = group->next; |
6953 | } while (group != sd->groups); | |
6954 | printk(KERN_CONT "\n"); | |
1da177e4 | 6955 | |
758b2cdc | 6956 | if (!cpumask_equal(sched_domain_span(sd), groupmask)) |
4dcf6aff | 6957 | printk(KERN_ERR "ERROR: groups don't span domain->span\n"); |
1da177e4 | 6958 | |
758b2cdc RR |
6959 | if (sd->parent && |
6960 | !cpumask_subset(groupmask, sched_domain_span(sd->parent))) | |
4dcf6aff IM |
6961 | printk(KERN_ERR "ERROR: parent span is not a superset " |
6962 | "of domain->span\n"); | |
6963 | return 0; | |
6964 | } | |
1da177e4 | 6965 | |
4dcf6aff IM |
6966 | static void sched_domain_debug(struct sched_domain *sd, int cpu) |
6967 | { | |
d5dd3db1 | 6968 | cpumask_var_t groupmask; |
4dcf6aff | 6969 | int level = 0; |
1da177e4 | 6970 | |
4dcf6aff IM |
6971 | if (!sd) { |
6972 | printk(KERN_DEBUG "CPU%d attaching NULL sched-domain.\n", cpu); | |
6973 | return; | |
6974 | } | |
1da177e4 | 6975 | |
4dcf6aff IM |
6976 | printk(KERN_DEBUG "CPU%d attaching sched-domain:\n", cpu); |
6977 | ||
d5dd3db1 | 6978 | if (!alloc_cpumask_var(&groupmask, GFP_KERNEL)) { |
7c16ec58 MT |
6979 | printk(KERN_DEBUG "Cannot load-balance (out of memory)\n"); |
6980 | return; | |
6981 | } | |
6982 | ||
4dcf6aff | 6983 | for (;;) { |
7c16ec58 | 6984 | if (sched_domain_debug_one(sd, cpu, level, groupmask)) |
4dcf6aff | 6985 | break; |
1da177e4 LT |
6986 | level++; |
6987 | sd = sd->parent; | |
33859f7f | 6988 | if (!sd) |
4dcf6aff IM |
6989 | break; |
6990 | } | |
d5dd3db1 | 6991 | free_cpumask_var(groupmask); |
1da177e4 | 6992 | } |
6d6bc0ad | 6993 | #else /* !CONFIG_SCHED_DEBUG */ |
48f24c4d | 6994 | # define sched_domain_debug(sd, cpu) do { } while (0) |
6d6bc0ad | 6995 | #endif /* CONFIG_SCHED_DEBUG */ |
1da177e4 | 6996 | |
1a20ff27 | 6997 | static int sd_degenerate(struct sched_domain *sd) |
245af2c7 | 6998 | { |
758b2cdc | 6999 | if (cpumask_weight(sched_domain_span(sd)) == 1) |
245af2c7 SS |
7000 | return 1; |
7001 | ||
7002 | /* Following flags need at least 2 groups */ | |
7003 | if (sd->flags & (SD_LOAD_BALANCE | | |
7004 | SD_BALANCE_NEWIDLE | | |
7005 | SD_BALANCE_FORK | | |
89c4710e SS |
7006 | SD_BALANCE_EXEC | |
7007 | SD_SHARE_CPUPOWER | | |
7008 | SD_SHARE_PKG_RESOURCES)) { | |
245af2c7 SS |
7009 | if (sd->groups != sd->groups->next) |
7010 | return 0; | |
7011 | } | |
7012 | ||
7013 | /* Following flags don't use groups */ | |
7014 | if (sd->flags & (SD_WAKE_IDLE | | |
7015 | SD_WAKE_AFFINE | | |
7016 | SD_WAKE_BALANCE)) | |
7017 | return 0; | |
7018 | ||
7019 | return 1; | |
7020 | } | |
7021 | ||
48f24c4d IM |
7022 | static int |
7023 | sd_parent_degenerate(struct sched_domain *sd, struct sched_domain *parent) | |
245af2c7 SS |
7024 | { |
7025 | unsigned long cflags = sd->flags, pflags = parent->flags; | |
7026 | ||
7027 | if (sd_degenerate(parent)) | |
7028 | return 1; | |
7029 | ||
758b2cdc | 7030 | if (!cpumask_equal(sched_domain_span(sd), sched_domain_span(parent))) |
245af2c7 SS |
7031 | return 0; |
7032 | ||
7033 | /* Does parent contain flags not in child? */ | |
7034 | /* WAKE_BALANCE is a subset of WAKE_AFFINE */ | |
7035 | if (cflags & SD_WAKE_AFFINE) | |
7036 | pflags &= ~SD_WAKE_BALANCE; | |
7037 | /* Flags needing groups don't count if only 1 group in parent */ | |
7038 | if (parent->groups == parent->groups->next) { | |
7039 | pflags &= ~(SD_LOAD_BALANCE | | |
7040 | SD_BALANCE_NEWIDLE | | |
7041 | SD_BALANCE_FORK | | |
89c4710e SS |
7042 | SD_BALANCE_EXEC | |
7043 | SD_SHARE_CPUPOWER | | |
7044 | SD_SHARE_PKG_RESOURCES); | |
5436499e KC |
7045 | if (nr_node_ids == 1) |
7046 | pflags &= ~SD_SERIALIZE; | |
245af2c7 SS |
7047 | } |
7048 | if (~cflags & pflags) | |
7049 | return 0; | |
7050 | ||
7051 | return 1; | |
7052 | } | |
7053 | ||
c6c4927b RR |
7054 | static void free_rootdomain(struct root_domain *rd) |
7055 | { | |
68e74568 RR |
7056 | cpupri_cleanup(&rd->cpupri); |
7057 | ||
c6c4927b RR |
7058 | free_cpumask_var(rd->rto_mask); |
7059 | free_cpumask_var(rd->online); | |
7060 | free_cpumask_var(rd->span); | |
7061 | kfree(rd); | |
7062 | } | |
7063 | ||
57d885fe GH |
7064 | static void rq_attach_root(struct rq *rq, struct root_domain *rd) |
7065 | { | |
7066 | unsigned long flags; | |
57d885fe GH |
7067 | |
7068 | spin_lock_irqsave(&rq->lock, flags); | |
7069 | ||
7070 | if (rq->rd) { | |
7071 | struct root_domain *old_rd = rq->rd; | |
7072 | ||
c6c4927b | 7073 | if (cpumask_test_cpu(rq->cpu, old_rd->online)) |
1f11eb6a | 7074 | set_rq_offline(rq); |
57d885fe | 7075 | |
c6c4927b | 7076 | cpumask_clear_cpu(rq->cpu, old_rd->span); |
dc938520 | 7077 | |
57d885fe | 7078 | if (atomic_dec_and_test(&old_rd->refcount)) |
c6c4927b | 7079 | free_rootdomain(old_rd); |
57d885fe GH |
7080 | } |
7081 | ||
7082 | atomic_inc(&rd->refcount); | |
7083 | rq->rd = rd; | |
7084 | ||
c6c4927b RR |
7085 | cpumask_set_cpu(rq->cpu, rd->span); |
7086 | if (cpumask_test_cpu(rq->cpu, cpu_online_mask)) | |
1f11eb6a | 7087 | set_rq_online(rq); |
57d885fe GH |
7088 | |
7089 | spin_unlock_irqrestore(&rq->lock, flags); | |
7090 | } | |
7091 | ||
db2f59c8 | 7092 | static int __init_refok init_rootdomain(struct root_domain *rd, bool bootmem) |
57d885fe GH |
7093 | { |
7094 | memset(rd, 0, sizeof(*rd)); | |
7095 | ||
c6c4927b RR |
7096 | if (bootmem) { |
7097 | alloc_bootmem_cpumask_var(&def_root_domain.span); | |
7098 | alloc_bootmem_cpumask_var(&def_root_domain.online); | |
7099 | alloc_bootmem_cpumask_var(&def_root_domain.rto_mask); | |
68e74568 | 7100 | cpupri_init(&rd->cpupri, true); |
c6c4927b RR |
7101 | return 0; |
7102 | } | |
7103 | ||
7104 | if (!alloc_cpumask_var(&rd->span, GFP_KERNEL)) | |
0c910d28 | 7105 | goto out; |
c6c4927b RR |
7106 | if (!alloc_cpumask_var(&rd->online, GFP_KERNEL)) |
7107 | goto free_span; | |
7108 | if (!alloc_cpumask_var(&rd->rto_mask, GFP_KERNEL)) | |
7109 | goto free_online; | |
6e0534f2 | 7110 | |
68e74568 RR |
7111 | if (cpupri_init(&rd->cpupri, false) != 0) |
7112 | goto free_rto_mask; | |
c6c4927b | 7113 | return 0; |
6e0534f2 | 7114 | |
68e74568 RR |
7115 | free_rto_mask: |
7116 | free_cpumask_var(rd->rto_mask); | |
c6c4927b RR |
7117 | free_online: |
7118 | free_cpumask_var(rd->online); | |
7119 | free_span: | |
7120 | free_cpumask_var(rd->span); | |
0c910d28 | 7121 | out: |
c6c4927b | 7122 | return -ENOMEM; |
57d885fe GH |
7123 | } |
7124 | ||
7125 | static void init_defrootdomain(void) | |
7126 | { | |
c6c4927b RR |
7127 | init_rootdomain(&def_root_domain, true); |
7128 | ||
57d885fe GH |
7129 | atomic_set(&def_root_domain.refcount, 1); |
7130 | } | |
7131 | ||
dc938520 | 7132 | static struct root_domain *alloc_rootdomain(void) |
57d885fe GH |
7133 | { |
7134 | struct root_domain *rd; | |
7135 | ||
7136 | rd = kmalloc(sizeof(*rd), GFP_KERNEL); | |
7137 | if (!rd) | |
7138 | return NULL; | |
7139 | ||
c6c4927b RR |
7140 | if (init_rootdomain(rd, false) != 0) { |
7141 | kfree(rd); | |
7142 | return NULL; | |
7143 | } | |
57d885fe GH |
7144 | |
7145 | return rd; | |
7146 | } | |
7147 | ||
1da177e4 | 7148 | /* |
0eab9146 | 7149 | * Attach the domain 'sd' to 'cpu' as its base domain. Callers must |
1da177e4 LT |
7150 | * hold the hotplug lock. |
7151 | */ | |
0eab9146 IM |
7152 | static void |
7153 | cpu_attach_domain(struct sched_domain *sd, struct root_domain *rd, int cpu) | |
1da177e4 | 7154 | { |
70b97a7f | 7155 | struct rq *rq = cpu_rq(cpu); |
245af2c7 SS |
7156 | struct sched_domain *tmp; |
7157 | ||
7158 | /* Remove the sched domains which do not contribute to scheduling. */ | |
f29c9b1c | 7159 | for (tmp = sd; tmp; ) { |
245af2c7 SS |
7160 | struct sched_domain *parent = tmp->parent; |
7161 | if (!parent) | |
7162 | break; | |
f29c9b1c | 7163 | |
1a848870 | 7164 | if (sd_parent_degenerate(tmp, parent)) { |
245af2c7 | 7165 | tmp->parent = parent->parent; |
1a848870 SS |
7166 | if (parent->parent) |
7167 | parent->parent->child = tmp; | |
f29c9b1c LZ |
7168 | } else |
7169 | tmp = tmp->parent; | |
245af2c7 SS |
7170 | } |
7171 | ||
1a848870 | 7172 | if (sd && sd_degenerate(sd)) { |
245af2c7 | 7173 | sd = sd->parent; |
1a848870 SS |
7174 | if (sd) |
7175 | sd->child = NULL; | |
7176 | } | |
1da177e4 LT |
7177 | |
7178 | sched_domain_debug(sd, cpu); | |
7179 | ||
57d885fe | 7180 | rq_attach_root(rq, rd); |
674311d5 | 7181 | rcu_assign_pointer(rq->sd, sd); |
1da177e4 LT |
7182 | } |
7183 | ||
7184 | /* cpus with isolated domains */ | |
dcc30a35 | 7185 | static cpumask_var_t cpu_isolated_map; |
1da177e4 LT |
7186 | |
7187 | /* Setup the mask of cpus configured for isolated domains */ | |
7188 | static int __init isolated_cpu_setup(char *str) | |
7189 | { | |
968ea6d8 | 7190 | cpulist_parse(str, cpu_isolated_map); |
1da177e4 LT |
7191 | return 1; |
7192 | } | |
7193 | ||
8927f494 | 7194 | __setup("isolcpus=", isolated_cpu_setup); |
1da177e4 LT |
7195 | |
7196 | /* | |
6711cab4 SS |
7197 | * init_sched_build_groups takes the cpumask we wish to span, and a pointer |
7198 | * to a function which identifies what group(along with sched group) a CPU | |
96f874e2 RR |
7199 | * belongs to. The return value of group_fn must be a >= 0 and < nr_cpu_ids |
7200 | * (due to the fact that we keep track of groups covered with a struct cpumask). | |
1da177e4 LT |
7201 | * |
7202 | * init_sched_build_groups will build a circular linked list of the groups | |
7203 | * covered by the given span, and will set each group's ->cpumask correctly, | |
7204 | * and ->cpu_power to 0. | |
7205 | */ | |
a616058b | 7206 | static void |
96f874e2 RR |
7207 | init_sched_build_groups(const struct cpumask *span, |
7208 | const struct cpumask *cpu_map, | |
7209 | int (*group_fn)(int cpu, const struct cpumask *cpu_map, | |
7c16ec58 | 7210 | struct sched_group **sg, |
96f874e2 RR |
7211 | struct cpumask *tmpmask), |
7212 | struct cpumask *covered, struct cpumask *tmpmask) | |
1da177e4 LT |
7213 | { |
7214 | struct sched_group *first = NULL, *last = NULL; | |
1da177e4 LT |
7215 | int i; |
7216 | ||
96f874e2 | 7217 | cpumask_clear(covered); |
7c16ec58 | 7218 | |
abcd083a | 7219 | for_each_cpu(i, span) { |
6711cab4 | 7220 | struct sched_group *sg; |
7c16ec58 | 7221 | int group = group_fn(i, cpu_map, &sg, tmpmask); |
1da177e4 LT |
7222 | int j; |
7223 | ||
758b2cdc | 7224 | if (cpumask_test_cpu(i, covered)) |
1da177e4 LT |
7225 | continue; |
7226 | ||
758b2cdc | 7227 | cpumask_clear(sched_group_cpus(sg)); |
5517d86b | 7228 | sg->__cpu_power = 0; |
1da177e4 | 7229 | |
abcd083a | 7230 | for_each_cpu(j, span) { |
7c16ec58 | 7231 | if (group_fn(j, cpu_map, NULL, tmpmask) != group) |
1da177e4 LT |
7232 | continue; |
7233 | ||
96f874e2 | 7234 | cpumask_set_cpu(j, covered); |
758b2cdc | 7235 | cpumask_set_cpu(j, sched_group_cpus(sg)); |
1da177e4 LT |
7236 | } |
7237 | if (!first) | |
7238 | first = sg; | |
7239 | if (last) | |
7240 | last->next = sg; | |
7241 | last = sg; | |
7242 | } | |
7243 | last->next = first; | |
7244 | } | |
7245 | ||
9c1cfda2 | 7246 | #define SD_NODES_PER_DOMAIN 16 |
1da177e4 | 7247 | |
9c1cfda2 | 7248 | #ifdef CONFIG_NUMA |
198e2f18 | 7249 | |
9c1cfda2 JH |
7250 | /** |
7251 | * find_next_best_node - find the next node to include in a sched_domain | |
7252 | * @node: node whose sched_domain we're building | |
7253 | * @used_nodes: nodes already in the sched_domain | |
7254 | * | |
41a2d6cf | 7255 | * Find the next node to include in a given scheduling domain. Simply |
9c1cfda2 JH |
7256 | * finds the closest node not already in the @used_nodes map. |
7257 | * | |
7258 | * Should use nodemask_t. | |
7259 | */ | |
c5f59f08 | 7260 | static int find_next_best_node(int node, nodemask_t *used_nodes) |
9c1cfda2 JH |
7261 | { |
7262 | int i, n, val, min_val, best_node = 0; | |
7263 | ||
7264 | min_val = INT_MAX; | |
7265 | ||
076ac2af | 7266 | for (i = 0; i < nr_node_ids; i++) { |
9c1cfda2 | 7267 | /* Start at @node */ |
076ac2af | 7268 | n = (node + i) % nr_node_ids; |
9c1cfda2 JH |
7269 | |
7270 | if (!nr_cpus_node(n)) | |
7271 | continue; | |
7272 | ||
7273 | /* Skip already used nodes */ | |
c5f59f08 | 7274 | if (node_isset(n, *used_nodes)) |
9c1cfda2 JH |
7275 | continue; |
7276 | ||
7277 | /* Simple min distance search */ | |
7278 | val = node_distance(node, n); | |
7279 | ||
7280 | if (val < min_val) { | |
7281 | min_val = val; | |
7282 | best_node = n; | |
7283 | } | |
7284 | } | |
7285 | ||
c5f59f08 | 7286 | node_set(best_node, *used_nodes); |
9c1cfda2 JH |
7287 | return best_node; |
7288 | } | |
7289 | ||
7290 | /** | |
7291 | * sched_domain_node_span - get a cpumask for a node's sched_domain | |
7292 | * @node: node whose cpumask we're constructing | |
73486722 | 7293 | * @span: resulting cpumask |
9c1cfda2 | 7294 | * |
41a2d6cf | 7295 | * Given a node, construct a good cpumask for its sched_domain to span. It |
9c1cfda2 JH |
7296 | * should be one that prevents unnecessary balancing, but also spreads tasks |
7297 | * out optimally. | |
7298 | */ | |
96f874e2 | 7299 | static void sched_domain_node_span(int node, struct cpumask *span) |
9c1cfda2 | 7300 | { |
c5f59f08 | 7301 | nodemask_t used_nodes; |
48f24c4d | 7302 | int i; |
9c1cfda2 | 7303 | |
6ca09dfc | 7304 | cpumask_clear(span); |
c5f59f08 | 7305 | nodes_clear(used_nodes); |
9c1cfda2 | 7306 | |
6ca09dfc | 7307 | cpumask_or(span, span, cpumask_of_node(node)); |
c5f59f08 | 7308 | node_set(node, used_nodes); |
9c1cfda2 JH |
7309 | |
7310 | for (i = 1; i < SD_NODES_PER_DOMAIN; i++) { | |
c5f59f08 | 7311 | int next_node = find_next_best_node(node, &used_nodes); |
48f24c4d | 7312 | |
6ca09dfc | 7313 | cpumask_or(span, span, cpumask_of_node(next_node)); |
9c1cfda2 | 7314 | } |
9c1cfda2 | 7315 | } |
6d6bc0ad | 7316 | #endif /* CONFIG_NUMA */ |
9c1cfda2 | 7317 | |
5c45bf27 | 7318 | int sched_smt_power_savings = 0, sched_mc_power_savings = 0; |
48f24c4d | 7319 | |
6c99e9ad RR |
7320 | /* |
7321 | * The cpus mask in sched_group and sched_domain hangs off the end. | |
7322 | * FIXME: use cpumask_var_t or dynamic percpu alloc to avoid wasting space | |
7323 | * for nr_cpu_ids < CONFIG_NR_CPUS. | |
7324 | */ | |
7325 | struct static_sched_group { | |
7326 | struct sched_group sg; | |
7327 | DECLARE_BITMAP(cpus, CONFIG_NR_CPUS); | |
7328 | }; | |
7329 | ||
7330 | struct static_sched_domain { | |
7331 | struct sched_domain sd; | |
7332 | DECLARE_BITMAP(span, CONFIG_NR_CPUS); | |
7333 | }; | |
7334 | ||
9c1cfda2 | 7335 | /* |
48f24c4d | 7336 | * SMT sched-domains: |
9c1cfda2 | 7337 | */ |
1da177e4 | 7338 | #ifdef CONFIG_SCHED_SMT |
6c99e9ad RR |
7339 | static DEFINE_PER_CPU(struct static_sched_domain, cpu_domains); |
7340 | static DEFINE_PER_CPU(struct static_sched_group, sched_group_cpus); | |
48f24c4d | 7341 | |
41a2d6cf | 7342 | static int |
96f874e2 RR |
7343 | cpu_to_cpu_group(int cpu, const struct cpumask *cpu_map, |
7344 | struct sched_group **sg, struct cpumask *unused) | |
1da177e4 | 7345 | { |
6711cab4 | 7346 | if (sg) |
6c99e9ad | 7347 | *sg = &per_cpu(sched_group_cpus, cpu).sg; |
1da177e4 LT |
7348 | return cpu; |
7349 | } | |
6d6bc0ad | 7350 | #endif /* CONFIG_SCHED_SMT */ |
1da177e4 | 7351 | |
48f24c4d IM |
7352 | /* |
7353 | * multi-core sched-domains: | |
7354 | */ | |
1e9f28fa | 7355 | #ifdef CONFIG_SCHED_MC |
6c99e9ad RR |
7356 | static DEFINE_PER_CPU(struct static_sched_domain, core_domains); |
7357 | static DEFINE_PER_CPU(struct static_sched_group, sched_group_core); | |
6d6bc0ad | 7358 | #endif /* CONFIG_SCHED_MC */ |
1e9f28fa SS |
7359 | |
7360 | #if defined(CONFIG_SCHED_MC) && defined(CONFIG_SCHED_SMT) | |
41a2d6cf | 7361 | static int |
96f874e2 RR |
7362 | cpu_to_core_group(int cpu, const struct cpumask *cpu_map, |
7363 | struct sched_group **sg, struct cpumask *mask) | |
1e9f28fa | 7364 | { |
6711cab4 | 7365 | int group; |
7c16ec58 | 7366 | |
96f874e2 RR |
7367 | cpumask_and(mask, &per_cpu(cpu_sibling_map, cpu), cpu_map); |
7368 | group = cpumask_first(mask); | |
6711cab4 | 7369 | if (sg) |
6c99e9ad | 7370 | *sg = &per_cpu(sched_group_core, group).sg; |
6711cab4 | 7371 | return group; |
1e9f28fa SS |
7372 | } |
7373 | #elif defined(CONFIG_SCHED_MC) | |
41a2d6cf | 7374 | static int |
96f874e2 RR |
7375 | cpu_to_core_group(int cpu, const struct cpumask *cpu_map, |
7376 | struct sched_group **sg, struct cpumask *unused) | |
1e9f28fa | 7377 | { |
6711cab4 | 7378 | if (sg) |
6c99e9ad | 7379 | *sg = &per_cpu(sched_group_core, cpu).sg; |
1e9f28fa SS |
7380 | return cpu; |
7381 | } | |
7382 | #endif | |
7383 | ||
6c99e9ad RR |
7384 | static DEFINE_PER_CPU(struct static_sched_domain, phys_domains); |
7385 | static DEFINE_PER_CPU(struct static_sched_group, sched_group_phys); | |
48f24c4d | 7386 | |
41a2d6cf | 7387 | static int |
96f874e2 RR |
7388 | cpu_to_phys_group(int cpu, const struct cpumask *cpu_map, |
7389 | struct sched_group **sg, struct cpumask *mask) | |
1da177e4 | 7390 | { |
6711cab4 | 7391 | int group; |
48f24c4d | 7392 | #ifdef CONFIG_SCHED_MC |
6ca09dfc | 7393 | cpumask_and(mask, cpu_coregroup_mask(cpu), cpu_map); |
96f874e2 | 7394 | group = cpumask_first(mask); |
1e9f28fa | 7395 | #elif defined(CONFIG_SCHED_SMT) |
96f874e2 RR |
7396 | cpumask_and(mask, &per_cpu(cpu_sibling_map, cpu), cpu_map); |
7397 | group = cpumask_first(mask); | |
1da177e4 | 7398 | #else |
6711cab4 | 7399 | group = cpu; |
1da177e4 | 7400 | #endif |
6711cab4 | 7401 | if (sg) |
6c99e9ad | 7402 | *sg = &per_cpu(sched_group_phys, group).sg; |
6711cab4 | 7403 | return group; |
1da177e4 LT |
7404 | } |
7405 | ||
7406 | #ifdef CONFIG_NUMA | |
1da177e4 | 7407 | /* |
9c1cfda2 JH |
7408 | * The init_sched_build_groups can't handle what we want to do with node |
7409 | * groups, so roll our own. Now each node has its own list of groups which | |
7410 | * gets dynamically allocated. | |
1da177e4 | 7411 | */ |
62ea9ceb | 7412 | static DEFINE_PER_CPU(struct static_sched_domain, node_domains); |
434d53b0 | 7413 | static struct sched_group ***sched_group_nodes_bycpu; |
1da177e4 | 7414 | |
62ea9ceb | 7415 | static DEFINE_PER_CPU(struct static_sched_domain, allnodes_domains); |
6c99e9ad | 7416 | static DEFINE_PER_CPU(struct static_sched_group, sched_group_allnodes); |
9c1cfda2 | 7417 | |
96f874e2 RR |
7418 | static int cpu_to_allnodes_group(int cpu, const struct cpumask *cpu_map, |
7419 | struct sched_group **sg, | |
7420 | struct cpumask *nodemask) | |
9c1cfda2 | 7421 | { |
6711cab4 SS |
7422 | int group; |
7423 | ||
6ca09dfc | 7424 | cpumask_and(nodemask, cpumask_of_node(cpu_to_node(cpu)), cpu_map); |
96f874e2 | 7425 | group = cpumask_first(nodemask); |
6711cab4 SS |
7426 | |
7427 | if (sg) | |
6c99e9ad | 7428 | *sg = &per_cpu(sched_group_allnodes, group).sg; |
6711cab4 | 7429 | return group; |
1da177e4 | 7430 | } |
6711cab4 | 7431 | |
08069033 SS |
7432 | static void init_numa_sched_groups_power(struct sched_group *group_head) |
7433 | { | |
7434 | struct sched_group *sg = group_head; | |
7435 | int j; | |
7436 | ||
7437 | if (!sg) | |
7438 | return; | |
3a5c359a | 7439 | do { |
758b2cdc | 7440 | for_each_cpu(j, sched_group_cpus(sg)) { |
3a5c359a | 7441 | struct sched_domain *sd; |
08069033 | 7442 | |
6c99e9ad | 7443 | sd = &per_cpu(phys_domains, j).sd; |
758b2cdc | 7444 | if (j != cpumask_first(sched_group_cpus(sd->groups))) { |
3a5c359a AK |
7445 | /* |
7446 | * Only add "power" once for each | |
7447 | * physical package. | |
7448 | */ | |
7449 | continue; | |
7450 | } | |
08069033 | 7451 | |
3a5c359a AK |
7452 | sg_inc_cpu_power(sg, sd->groups->__cpu_power); |
7453 | } | |
7454 | sg = sg->next; | |
7455 | } while (sg != group_head); | |
08069033 | 7456 | } |
6d6bc0ad | 7457 | #endif /* CONFIG_NUMA */ |
1da177e4 | 7458 | |
a616058b | 7459 | #ifdef CONFIG_NUMA |
51888ca2 | 7460 | /* Free memory allocated for various sched_group structures */ |
96f874e2 RR |
7461 | static void free_sched_groups(const struct cpumask *cpu_map, |
7462 | struct cpumask *nodemask) | |
51888ca2 | 7463 | { |
a616058b | 7464 | int cpu, i; |
51888ca2 | 7465 | |
abcd083a | 7466 | for_each_cpu(cpu, cpu_map) { |
51888ca2 SV |
7467 | struct sched_group **sched_group_nodes |
7468 | = sched_group_nodes_bycpu[cpu]; | |
7469 | ||
51888ca2 SV |
7470 | if (!sched_group_nodes) |
7471 | continue; | |
7472 | ||
076ac2af | 7473 | for (i = 0; i < nr_node_ids; i++) { |
51888ca2 SV |
7474 | struct sched_group *oldsg, *sg = sched_group_nodes[i]; |
7475 | ||
6ca09dfc | 7476 | cpumask_and(nodemask, cpumask_of_node(i), cpu_map); |
96f874e2 | 7477 | if (cpumask_empty(nodemask)) |
51888ca2 SV |
7478 | continue; |
7479 | ||
7480 | if (sg == NULL) | |
7481 | continue; | |
7482 | sg = sg->next; | |
7483 | next_sg: | |
7484 | oldsg = sg; | |
7485 | sg = sg->next; | |
7486 | kfree(oldsg); | |
7487 | if (oldsg != sched_group_nodes[i]) | |
7488 | goto next_sg; | |
7489 | } | |
7490 | kfree(sched_group_nodes); | |
7491 | sched_group_nodes_bycpu[cpu] = NULL; | |
7492 | } | |
51888ca2 | 7493 | } |
6d6bc0ad | 7494 | #else /* !CONFIG_NUMA */ |
96f874e2 RR |
7495 | static void free_sched_groups(const struct cpumask *cpu_map, |
7496 | struct cpumask *nodemask) | |
a616058b SS |
7497 | { |
7498 | } | |
6d6bc0ad | 7499 | #endif /* CONFIG_NUMA */ |
51888ca2 | 7500 | |
89c4710e SS |
7501 | /* |
7502 | * Initialize sched groups cpu_power. | |
7503 | * | |
7504 | * cpu_power indicates the capacity of sched group, which is used while | |
7505 | * distributing the load between different sched groups in a sched domain. | |
7506 | * Typically cpu_power for all the groups in a sched domain will be same unless | |
7507 | * there are asymmetries in the topology. If there are asymmetries, group | |
7508 | * having more cpu_power will pickup more load compared to the group having | |
7509 | * less cpu_power. | |
7510 | * | |
7511 | * cpu_power will be a multiple of SCHED_LOAD_SCALE. This multiple represents | |
7512 | * the maximum number of tasks a group can handle in the presence of other idle | |
7513 | * or lightly loaded groups in the same sched domain. | |
7514 | */ | |
7515 | static void init_sched_groups_power(int cpu, struct sched_domain *sd) | |
7516 | { | |
7517 | struct sched_domain *child; | |
7518 | struct sched_group *group; | |
7519 | ||
7520 | WARN_ON(!sd || !sd->groups); | |
7521 | ||
758b2cdc | 7522 | if (cpu != cpumask_first(sched_group_cpus(sd->groups))) |
89c4710e SS |
7523 | return; |
7524 | ||
7525 | child = sd->child; | |
7526 | ||
5517d86b ED |
7527 | sd->groups->__cpu_power = 0; |
7528 | ||
89c4710e SS |
7529 | /* |
7530 | * For perf policy, if the groups in child domain share resources | |
7531 | * (for example cores sharing some portions of the cache hierarchy | |
7532 | * or SMT), then set this domain groups cpu_power such that each group | |
7533 | * can handle only one task, when there are other idle groups in the | |
7534 | * same sched domain. | |
7535 | */ | |
7536 | if (!child || (!(sd->flags & SD_POWERSAVINGS_BALANCE) && | |
7537 | (child->flags & | |
7538 | (SD_SHARE_CPUPOWER | SD_SHARE_PKG_RESOURCES)))) { | |
5517d86b | 7539 | sg_inc_cpu_power(sd->groups, SCHED_LOAD_SCALE); |
89c4710e SS |
7540 | return; |
7541 | } | |
7542 | ||
89c4710e SS |
7543 | /* |
7544 | * add cpu_power of each child group to this groups cpu_power | |
7545 | */ | |
7546 | group = child->groups; | |
7547 | do { | |
5517d86b | 7548 | sg_inc_cpu_power(sd->groups, group->__cpu_power); |
89c4710e SS |
7549 | group = group->next; |
7550 | } while (group != child->groups); | |
7551 | } | |
7552 | ||
7c16ec58 MT |
7553 | /* |
7554 | * Initializers for schedule domains | |
7555 | * Non-inlined to reduce accumulated stack pressure in build_sched_domains() | |
7556 | */ | |
7557 | ||
a5d8c348 IM |
7558 | #ifdef CONFIG_SCHED_DEBUG |
7559 | # define SD_INIT_NAME(sd, type) sd->name = #type | |
7560 | #else | |
7561 | # define SD_INIT_NAME(sd, type) do { } while (0) | |
7562 | #endif | |
7563 | ||
7c16ec58 | 7564 | #define SD_INIT(sd, type) sd_init_##type(sd) |
a5d8c348 | 7565 | |
7c16ec58 MT |
7566 | #define SD_INIT_FUNC(type) \ |
7567 | static noinline void sd_init_##type(struct sched_domain *sd) \ | |
7568 | { \ | |
7569 | memset(sd, 0, sizeof(*sd)); \ | |
7570 | *sd = SD_##type##_INIT; \ | |
1d3504fc | 7571 | sd->level = SD_LV_##type; \ |
a5d8c348 | 7572 | SD_INIT_NAME(sd, type); \ |
7c16ec58 MT |
7573 | } |
7574 | ||
7575 | SD_INIT_FUNC(CPU) | |
7576 | #ifdef CONFIG_NUMA | |
7577 | SD_INIT_FUNC(ALLNODES) | |
7578 | SD_INIT_FUNC(NODE) | |
7579 | #endif | |
7580 | #ifdef CONFIG_SCHED_SMT | |
7581 | SD_INIT_FUNC(SIBLING) | |
7582 | #endif | |
7583 | #ifdef CONFIG_SCHED_MC | |
7584 | SD_INIT_FUNC(MC) | |
7585 | #endif | |
7586 | ||
1d3504fc HS |
7587 | static int default_relax_domain_level = -1; |
7588 | ||
7589 | static int __init setup_relax_domain_level(char *str) | |
7590 | { | |
30e0e178 LZ |
7591 | unsigned long val; |
7592 | ||
7593 | val = simple_strtoul(str, NULL, 0); | |
7594 | if (val < SD_LV_MAX) | |
7595 | default_relax_domain_level = val; | |
7596 | ||
1d3504fc HS |
7597 | return 1; |
7598 | } | |
7599 | __setup("relax_domain_level=", setup_relax_domain_level); | |
7600 | ||
7601 | static void set_domain_attribute(struct sched_domain *sd, | |
7602 | struct sched_domain_attr *attr) | |
7603 | { | |
7604 | int request; | |
7605 | ||
7606 | if (!attr || attr->relax_domain_level < 0) { | |
7607 | if (default_relax_domain_level < 0) | |
7608 | return; | |
7609 | else | |
7610 | request = default_relax_domain_level; | |
7611 | } else | |
7612 | request = attr->relax_domain_level; | |
7613 | if (request < sd->level) { | |
7614 | /* turn off idle balance on this domain */ | |
7615 | sd->flags &= ~(SD_WAKE_IDLE|SD_BALANCE_NEWIDLE); | |
7616 | } else { | |
7617 | /* turn on idle balance on this domain */ | |
7618 | sd->flags |= (SD_WAKE_IDLE_FAR|SD_BALANCE_NEWIDLE); | |
7619 | } | |
7620 | } | |
7621 | ||
1da177e4 | 7622 | /* |
1a20ff27 DG |
7623 | * Build sched domains for a given set of cpus and attach the sched domains |
7624 | * to the individual cpus | |
1da177e4 | 7625 | */ |
96f874e2 | 7626 | static int __build_sched_domains(const struct cpumask *cpu_map, |
1d3504fc | 7627 | struct sched_domain_attr *attr) |
1da177e4 | 7628 | { |
3404c8d9 | 7629 | int i, err = -ENOMEM; |
57d885fe | 7630 | struct root_domain *rd; |
3404c8d9 RR |
7631 | cpumask_var_t nodemask, this_sibling_map, this_core_map, send_covered, |
7632 | tmpmask; | |
d1b55138 | 7633 | #ifdef CONFIG_NUMA |
3404c8d9 | 7634 | cpumask_var_t domainspan, covered, notcovered; |
d1b55138 | 7635 | struct sched_group **sched_group_nodes = NULL; |
6711cab4 | 7636 | int sd_allnodes = 0; |
d1b55138 | 7637 | |
3404c8d9 RR |
7638 | if (!alloc_cpumask_var(&domainspan, GFP_KERNEL)) |
7639 | goto out; | |
7640 | if (!alloc_cpumask_var(&covered, GFP_KERNEL)) | |
7641 | goto free_domainspan; | |
7642 | if (!alloc_cpumask_var(¬covered, GFP_KERNEL)) | |
7643 | goto free_covered; | |
7644 | #endif | |
7645 | ||
7646 | if (!alloc_cpumask_var(&nodemask, GFP_KERNEL)) | |
7647 | goto free_notcovered; | |
7648 | if (!alloc_cpumask_var(&this_sibling_map, GFP_KERNEL)) | |
7649 | goto free_nodemask; | |
7650 | if (!alloc_cpumask_var(&this_core_map, GFP_KERNEL)) | |
7651 | goto free_this_sibling_map; | |
7652 | if (!alloc_cpumask_var(&send_covered, GFP_KERNEL)) | |
7653 | goto free_this_core_map; | |
7654 | if (!alloc_cpumask_var(&tmpmask, GFP_KERNEL)) | |
7655 | goto free_send_covered; | |
7656 | ||
7657 | #ifdef CONFIG_NUMA | |
d1b55138 JH |
7658 | /* |
7659 | * Allocate the per-node list of sched groups | |
7660 | */ | |
076ac2af | 7661 | sched_group_nodes = kcalloc(nr_node_ids, sizeof(struct sched_group *), |
41a2d6cf | 7662 | GFP_KERNEL); |
d1b55138 JH |
7663 | if (!sched_group_nodes) { |
7664 | printk(KERN_WARNING "Can not alloc sched group node list\n"); | |
3404c8d9 | 7665 | goto free_tmpmask; |
d1b55138 | 7666 | } |
d1b55138 | 7667 | #endif |
1da177e4 | 7668 | |
dc938520 | 7669 | rd = alloc_rootdomain(); |
57d885fe GH |
7670 | if (!rd) { |
7671 | printk(KERN_WARNING "Cannot alloc root domain\n"); | |
3404c8d9 | 7672 | goto free_sched_groups; |
57d885fe GH |
7673 | } |
7674 | ||
7c16ec58 | 7675 | #ifdef CONFIG_NUMA |
96f874e2 | 7676 | sched_group_nodes_bycpu[cpumask_first(cpu_map)] = sched_group_nodes; |
7c16ec58 MT |
7677 | #endif |
7678 | ||
1da177e4 | 7679 | /* |
1a20ff27 | 7680 | * Set up domains for cpus specified by the cpu_map. |
1da177e4 | 7681 | */ |
abcd083a | 7682 | for_each_cpu(i, cpu_map) { |
1da177e4 | 7683 | struct sched_domain *sd = NULL, *p; |
1da177e4 | 7684 | |
6ca09dfc | 7685 | cpumask_and(nodemask, cpumask_of_node(cpu_to_node(i)), cpu_map); |
1da177e4 LT |
7686 | |
7687 | #ifdef CONFIG_NUMA | |
96f874e2 RR |
7688 | if (cpumask_weight(cpu_map) > |
7689 | SD_NODES_PER_DOMAIN*cpumask_weight(nodemask)) { | |
62ea9ceb | 7690 | sd = &per_cpu(allnodes_domains, i).sd; |
7c16ec58 | 7691 | SD_INIT(sd, ALLNODES); |
1d3504fc | 7692 | set_domain_attribute(sd, attr); |
758b2cdc | 7693 | cpumask_copy(sched_domain_span(sd), cpu_map); |
7c16ec58 | 7694 | cpu_to_allnodes_group(i, cpu_map, &sd->groups, tmpmask); |
9c1cfda2 | 7695 | p = sd; |
6711cab4 | 7696 | sd_allnodes = 1; |
9c1cfda2 JH |
7697 | } else |
7698 | p = NULL; | |
7699 | ||
62ea9ceb | 7700 | sd = &per_cpu(node_domains, i).sd; |
7c16ec58 | 7701 | SD_INIT(sd, NODE); |
1d3504fc | 7702 | set_domain_attribute(sd, attr); |
758b2cdc | 7703 | sched_domain_node_span(cpu_to_node(i), sched_domain_span(sd)); |
9c1cfda2 | 7704 | sd->parent = p; |
1a848870 SS |
7705 | if (p) |
7706 | p->child = sd; | |
758b2cdc RR |
7707 | cpumask_and(sched_domain_span(sd), |
7708 | sched_domain_span(sd), cpu_map); | |
1da177e4 LT |
7709 | #endif |
7710 | ||
7711 | p = sd; | |
6c99e9ad | 7712 | sd = &per_cpu(phys_domains, i).sd; |
7c16ec58 | 7713 | SD_INIT(sd, CPU); |
1d3504fc | 7714 | set_domain_attribute(sd, attr); |
758b2cdc | 7715 | cpumask_copy(sched_domain_span(sd), nodemask); |
1da177e4 | 7716 | sd->parent = p; |
1a848870 SS |
7717 | if (p) |
7718 | p->child = sd; | |
7c16ec58 | 7719 | cpu_to_phys_group(i, cpu_map, &sd->groups, tmpmask); |
1da177e4 | 7720 | |
1e9f28fa SS |
7721 | #ifdef CONFIG_SCHED_MC |
7722 | p = sd; | |
6c99e9ad | 7723 | sd = &per_cpu(core_domains, i).sd; |
7c16ec58 | 7724 | SD_INIT(sd, MC); |
1d3504fc | 7725 | set_domain_attribute(sd, attr); |
6ca09dfc MT |
7726 | cpumask_and(sched_domain_span(sd), cpu_map, |
7727 | cpu_coregroup_mask(i)); | |
1e9f28fa | 7728 | sd->parent = p; |
1a848870 | 7729 | p->child = sd; |
7c16ec58 | 7730 | cpu_to_core_group(i, cpu_map, &sd->groups, tmpmask); |
1e9f28fa SS |
7731 | #endif |
7732 | ||
1da177e4 LT |
7733 | #ifdef CONFIG_SCHED_SMT |
7734 | p = sd; | |
6c99e9ad | 7735 | sd = &per_cpu(cpu_domains, i).sd; |
7c16ec58 | 7736 | SD_INIT(sd, SIBLING); |
1d3504fc | 7737 | set_domain_attribute(sd, attr); |
758b2cdc RR |
7738 | cpumask_and(sched_domain_span(sd), |
7739 | &per_cpu(cpu_sibling_map, i), cpu_map); | |
1da177e4 | 7740 | sd->parent = p; |
1a848870 | 7741 | p->child = sd; |
7c16ec58 | 7742 | cpu_to_cpu_group(i, cpu_map, &sd->groups, tmpmask); |
1da177e4 LT |
7743 | #endif |
7744 | } | |
7745 | ||
7746 | #ifdef CONFIG_SCHED_SMT | |
7747 | /* Set up CPU (sibling) groups */ | |
abcd083a | 7748 | for_each_cpu(i, cpu_map) { |
96f874e2 RR |
7749 | cpumask_and(this_sibling_map, |
7750 | &per_cpu(cpu_sibling_map, i), cpu_map); | |
7751 | if (i != cpumask_first(this_sibling_map)) | |
1da177e4 LT |
7752 | continue; |
7753 | ||
dd41f596 | 7754 | init_sched_build_groups(this_sibling_map, cpu_map, |
7c16ec58 MT |
7755 | &cpu_to_cpu_group, |
7756 | send_covered, tmpmask); | |
1da177e4 LT |
7757 | } |
7758 | #endif | |
7759 | ||
1e9f28fa SS |
7760 | #ifdef CONFIG_SCHED_MC |
7761 | /* Set up multi-core groups */ | |
abcd083a | 7762 | for_each_cpu(i, cpu_map) { |
6ca09dfc | 7763 | cpumask_and(this_core_map, cpu_coregroup_mask(i), cpu_map); |
96f874e2 | 7764 | if (i != cpumask_first(this_core_map)) |
1e9f28fa | 7765 | continue; |
7c16ec58 | 7766 | |
dd41f596 | 7767 | init_sched_build_groups(this_core_map, cpu_map, |
7c16ec58 MT |
7768 | &cpu_to_core_group, |
7769 | send_covered, tmpmask); | |
1e9f28fa SS |
7770 | } |
7771 | #endif | |
7772 | ||
1da177e4 | 7773 | /* Set up physical groups */ |
076ac2af | 7774 | for (i = 0; i < nr_node_ids; i++) { |
6ca09dfc | 7775 | cpumask_and(nodemask, cpumask_of_node(i), cpu_map); |
96f874e2 | 7776 | if (cpumask_empty(nodemask)) |
1da177e4 LT |
7777 | continue; |
7778 | ||
7c16ec58 MT |
7779 | init_sched_build_groups(nodemask, cpu_map, |
7780 | &cpu_to_phys_group, | |
7781 | send_covered, tmpmask); | |
1da177e4 LT |
7782 | } |
7783 | ||
7784 | #ifdef CONFIG_NUMA | |
7785 | /* Set up node groups */ | |
7c16ec58 | 7786 | if (sd_allnodes) { |
7c16ec58 MT |
7787 | init_sched_build_groups(cpu_map, cpu_map, |
7788 | &cpu_to_allnodes_group, | |
7789 | send_covered, tmpmask); | |
7790 | } | |
9c1cfda2 | 7791 | |
076ac2af | 7792 | for (i = 0; i < nr_node_ids; i++) { |
9c1cfda2 JH |
7793 | /* Set up node groups */ |
7794 | struct sched_group *sg, *prev; | |
9c1cfda2 JH |
7795 | int j; |
7796 | ||
96f874e2 | 7797 | cpumask_clear(covered); |
6ca09dfc | 7798 | cpumask_and(nodemask, cpumask_of_node(i), cpu_map); |
96f874e2 | 7799 | if (cpumask_empty(nodemask)) { |
d1b55138 | 7800 | sched_group_nodes[i] = NULL; |
9c1cfda2 | 7801 | continue; |
d1b55138 | 7802 | } |
9c1cfda2 | 7803 | |
4bdbaad3 | 7804 | sched_domain_node_span(i, domainspan); |
96f874e2 | 7805 | cpumask_and(domainspan, domainspan, cpu_map); |
9c1cfda2 | 7806 | |
6c99e9ad RR |
7807 | sg = kmalloc_node(sizeof(struct sched_group) + cpumask_size(), |
7808 | GFP_KERNEL, i); | |
51888ca2 SV |
7809 | if (!sg) { |
7810 | printk(KERN_WARNING "Can not alloc domain group for " | |
7811 | "node %d\n", i); | |
7812 | goto error; | |
7813 | } | |
9c1cfda2 | 7814 | sched_group_nodes[i] = sg; |
abcd083a | 7815 | for_each_cpu(j, nodemask) { |
9c1cfda2 | 7816 | struct sched_domain *sd; |
9761eea8 | 7817 | |
62ea9ceb | 7818 | sd = &per_cpu(node_domains, j).sd; |
9c1cfda2 | 7819 | sd->groups = sg; |
9c1cfda2 | 7820 | } |
5517d86b | 7821 | sg->__cpu_power = 0; |
758b2cdc | 7822 | cpumask_copy(sched_group_cpus(sg), nodemask); |
51888ca2 | 7823 | sg->next = sg; |
96f874e2 | 7824 | cpumask_or(covered, covered, nodemask); |
9c1cfda2 JH |
7825 | prev = sg; |
7826 | ||
076ac2af | 7827 | for (j = 0; j < nr_node_ids; j++) { |
076ac2af | 7828 | int n = (i + j) % nr_node_ids; |
9c1cfda2 | 7829 | |
96f874e2 RR |
7830 | cpumask_complement(notcovered, covered); |
7831 | cpumask_and(tmpmask, notcovered, cpu_map); | |
7832 | cpumask_and(tmpmask, tmpmask, domainspan); | |
7833 | if (cpumask_empty(tmpmask)) | |
9c1cfda2 JH |
7834 | break; |
7835 | ||
6ca09dfc | 7836 | cpumask_and(tmpmask, tmpmask, cpumask_of_node(n)); |
96f874e2 | 7837 | if (cpumask_empty(tmpmask)) |
9c1cfda2 JH |
7838 | continue; |
7839 | ||
6c99e9ad RR |
7840 | sg = kmalloc_node(sizeof(struct sched_group) + |
7841 | cpumask_size(), | |
15f0b676 | 7842 | GFP_KERNEL, i); |
9c1cfda2 JH |
7843 | if (!sg) { |
7844 | printk(KERN_WARNING | |
7845 | "Can not alloc domain group for node %d\n", j); | |
51888ca2 | 7846 | goto error; |
9c1cfda2 | 7847 | } |
5517d86b | 7848 | sg->__cpu_power = 0; |
758b2cdc | 7849 | cpumask_copy(sched_group_cpus(sg), tmpmask); |
51888ca2 | 7850 | sg->next = prev->next; |
96f874e2 | 7851 | cpumask_or(covered, covered, tmpmask); |
9c1cfda2 JH |
7852 | prev->next = sg; |
7853 | prev = sg; | |
7854 | } | |
9c1cfda2 | 7855 | } |
1da177e4 LT |
7856 | #endif |
7857 | ||
7858 | /* Calculate CPU power for physical packages and nodes */ | |
5c45bf27 | 7859 | #ifdef CONFIG_SCHED_SMT |
abcd083a | 7860 | for_each_cpu(i, cpu_map) { |
6c99e9ad | 7861 | struct sched_domain *sd = &per_cpu(cpu_domains, i).sd; |
dd41f596 | 7862 | |
89c4710e | 7863 | init_sched_groups_power(i, sd); |
5c45bf27 | 7864 | } |
1da177e4 | 7865 | #endif |
1e9f28fa | 7866 | #ifdef CONFIG_SCHED_MC |
abcd083a | 7867 | for_each_cpu(i, cpu_map) { |
6c99e9ad | 7868 | struct sched_domain *sd = &per_cpu(core_domains, i).sd; |
dd41f596 | 7869 | |
89c4710e | 7870 | init_sched_groups_power(i, sd); |
5c45bf27 SS |
7871 | } |
7872 | #endif | |
1e9f28fa | 7873 | |
abcd083a | 7874 | for_each_cpu(i, cpu_map) { |
6c99e9ad | 7875 | struct sched_domain *sd = &per_cpu(phys_domains, i).sd; |
dd41f596 | 7876 | |
89c4710e | 7877 | init_sched_groups_power(i, sd); |
1da177e4 LT |
7878 | } |
7879 | ||
9c1cfda2 | 7880 | #ifdef CONFIG_NUMA |
076ac2af | 7881 | for (i = 0; i < nr_node_ids; i++) |
08069033 | 7882 | init_numa_sched_groups_power(sched_group_nodes[i]); |
9c1cfda2 | 7883 | |
6711cab4 SS |
7884 | if (sd_allnodes) { |
7885 | struct sched_group *sg; | |
f712c0c7 | 7886 | |
96f874e2 | 7887 | cpu_to_allnodes_group(cpumask_first(cpu_map), cpu_map, &sg, |
7c16ec58 | 7888 | tmpmask); |
f712c0c7 SS |
7889 | init_numa_sched_groups_power(sg); |
7890 | } | |
9c1cfda2 JH |
7891 | #endif |
7892 | ||
1da177e4 | 7893 | /* Attach the domains */ |
abcd083a | 7894 | for_each_cpu(i, cpu_map) { |
1da177e4 LT |
7895 | struct sched_domain *sd; |
7896 | #ifdef CONFIG_SCHED_SMT | |
6c99e9ad | 7897 | sd = &per_cpu(cpu_domains, i).sd; |
1e9f28fa | 7898 | #elif defined(CONFIG_SCHED_MC) |
6c99e9ad | 7899 | sd = &per_cpu(core_domains, i).sd; |
1da177e4 | 7900 | #else |
6c99e9ad | 7901 | sd = &per_cpu(phys_domains, i).sd; |
1da177e4 | 7902 | #endif |
57d885fe | 7903 | cpu_attach_domain(sd, rd, i); |
1da177e4 | 7904 | } |
51888ca2 | 7905 | |
3404c8d9 RR |
7906 | err = 0; |
7907 | ||
7908 | free_tmpmask: | |
7909 | free_cpumask_var(tmpmask); | |
7910 | free_send_covered: | |
7911 | free_cpumask_var(send_covered); | |
7912 | free_this_core_map: | |
7913 | free_cpumask_var(this_core_map); | |
7914 | free_this_sibling_map: | |
7915 | free_cpumask_var(this_sibling_map); | |
7916 | free_nodemask: | |
7917 | free_cpumask_var(nodemask); | |
7918 | free_notcovered: | |
7919 | #ifdef CONFIG_NUMA | |
7920 | free_cpumask_var(notcovered); | |
7921 | free_covered: | |
7922 | free_cpumask_var(covered); | |
7923 | free_domainspan: | |
7924 | free_cpumask_var(domainspan); | |
7925 | out: | |
7926 | #endif | |
7927 | return err; | |
7928 | ||
7929 | free_sched_groups: | |
7930 | #ifdef CONFIG_NUMA | |
7931 | kfree(sched_group_nodes); | |
7932 | #endif | |
7933 | goto free_tmpmask; | |
51888ca2 | 7934 | |
a616058b | 7935 | #ifdef CONFIG_NUMA |
51888ca2 | 7936 | error: |
7c16ec58 | 7937 | free_sched_groups(cpu_map, tmpmask); |
c6c4927b | 7938 | free_rootdomain(rd); |
3404c8d9 | 7939 | goto free_tmpmask; |
a616058b | 7940 | #endif |
1da177e4 | 7941 | } |
029190c5 | 7942 | |
96f874e2 | 7943 | static int build_sched_domains(const struct cpumask *cpu_map) |
1d3504fc HS |
7944 | { |
7945 | return __build_sched_domains(cpu_map, NULL); | |
7946 | } | |
7947 | ||
96f874e2 | 7948 | static struct cpumask *doms_cur; /* current sched domains */ |
029190c5 | 7949 | static int ndoms_cur; /* number of sched domains in 'doms_cur' */ |
4285f594 IM |
7950 | static struct sched_domain_attr *dattr_cur; |
7951 | /* attribues of custom domains in 'doms_cur' */ | |
029190c5 PJ |
7952 | |
7953 | /* | |
7954 | * Special case: If a kmalloc of a doms_cur partition (array of | |
4212823f RR |
7955 | * cpumask) fails, then fallback to a single sched domain, |
7956 | * as determined by the single cpumask fallback_doms. | |
029190c5 | 7957 | */ |
4212823f | 7958 | static cpumask_var_t fallback_doms; |
029190c5 | 7959 | |
ee79d1bd HC |
7960 | /* |
7961 | * arch_update_cpu_topology lets virtualized architectures update the | |
7962 | * cpu core maps. It is supposed to return 1 if the topology changed | |
7963 | * or 0 if it stayed the same. | |
7964 | */ | |
7965 | int __attribute__((weak)) arch_update_cpu_topology(void) | |
22e52b07 | 7966 | { |
ee79d1bd | 7967 | return 0; |
22e52b07 HC |
7968 | } |
7969 | ||
1a20ff27 | 7970 | /* |
41a2d6cf | 7971 | * Set up scheduler domains and groups. Callers must hold the hotplug lock. |
029190c5 PJ |
7972 | * For now this just excludes isolated cpus, but could be used to |
7973 | * exclude other special cases in the future. | |
1a20ff27 | 7974 | */ |
96f874e2 | 7975 | static int arch_init_sched_domains(const struct cpumask *cpu_map) |
1a20ff27 | 7976 | { |
7378547f MM |
7977 | int err; |
7978 | ||
22e52b07 | 7979 | arch_update_cpu_topology(); |
029190c5 | 7980 | ndoms_cur = 1; |
96f874e2 | 7981 | doms_cur = kmalloc(cpumask_size(), GFP_KERNEL); |
029190c5 | 7982 | if (!doms_cur) |
4212823f | 7983 | doms_cur = fallback_doms; |
dcc30a35 | 7984 | cpumask_andnot(doms_cur, cpu_map, cpu_isolated_map); |
1d3504fc | 7985 | dattr_cur = NULL; |
7378547f | 7986 | err = build_sched_domains(doms_cur); |
6382bc90 | 7987 | register_sched_domain_sysctl(); |
7378547f MM |
7988 | |
7989 | return err; | |
1a20ff27 DG |
7990 | } |
7991 | ||
96f874e2 RR |
7992 | static void arch_destroy_sched_domains(const struct cpumask *cpu_map, |
7993 | struct cpumask *tmpmask) | |
1da177e4 | 7994 | { |
7c16ec58 | 7995 | free_sched_groups(cpu_map, tmpmask); |
9c1cfda2 | 7996 | } |
1da177e4 | 7997 | |
1a20ff27 DG |
7998 | /* |
7999 | * Detach sched domains from a group of cpus specified in cpu_map | |
8000 | * These cpus will now be attached to the NULL domain | |
8001 | */ | |
96f874e2 | 8002 | static void detach_destroy_domains(const struct cpumask *cpu_map) |
1a20ff27 | 8003 | { |
96f874e2 RR |
8004 | /* Save because hotplug lock held. */ |
8005 | static DECLARE_BITMAP(tmpmask, CONFIG_NR_CPUS); | |
1a20ff27 DG |
8006 | int i; |
8007 | ||
abcd083a | 8008 | for_each_cpu(i, cpu_map) |
57d885fe | 8009 | cpu_attach_domain(NULL, &def_root_domain, i); |
1a20ff27 | 8010 | synchronize_sched(); |
96f874e2 | 8011 | arch_destroy_sched_domains(cpu_map, to_cpumask(tmpmask)); |
1a20ff27 DG |
8012 | } |
8013 | ||
1d3504fc HS |
8014 | /* handle null as "default" */ |
8015 | static int dattrs_equal(struct sched_domain_attr *cur, int idx_cur, | |
8016 | struct sched_domain_attr *new, int idx_new) | |
8017 | { | |
8018 | struct sched_domain_attr tmp; | |
8019 | ||
8020 | /* fast path */ | |
8021 | if (!new && !cur) | |
8022 | return 1; | |
8023 | ||
8024 | tmp = SD_ATTR_INIT; | |
8025 | return !memcmp(cur ? (cur + idx_cur) : &tmp, | |
8026 | new ? (new + idx_new) : &tmp, | |
8027 | sizeof(struct sched_domain_attr)); | |
8028 | } | |
8029 | ||
029190c5 PJ |
8030 | /* |
8031 | * Partition sched domains as specified by the 'ndoms_new' | |
41a2d6cf | 8032 | * cpumasks in the array doms_new[] of cpumasks. This compares |
029190c5 PJ |
8033 | * doms_new[] to the current sched domain partitioning, doms_cur[]. |
8034 | * It destroys each deleted domain and builds each new domain. | |
8035 | * | |
96f874e2 | 8036 | * 'doms_new' is an array of cpumask's of length 'ndoms_new'. |
41a2d6cf IM |
8037 | * The masks don't intersect (don't overlap.) We should setup one |
8038 | * sched domain for each mask. CPUs not in any of the cpumasks will | |
8039 | * not be load balanced. If the same cpumask appears both in the | |
029190c5 PJ |
8040 | * current 'doms_cur' domains and in the new 'doms_new', we can leave |
8041 | * it as it is. | |
8042 | * | |
41a2d6cf IM |
8043 | * The passed in 'doms_new' should be kmalloc'd. This routine takes |
8044 | * ownership of it and will kfree it when done with it. If the caller | |
700018e0 LZ |
8045 | * failed the kmalloc call, then it can pass in doms_new == NULL && |
8046 | * ndoms_new == 1, and partition_sched_domains() will fallback to | |
8047 | * the single partition 'fallback_doms', it also forces the domains | |
8048 | * to be rebuilt. | |
029190c5 | 8049 | * |
96f874e2 | 8050 | * If doms_new == NULL it will be replaced with cpu_online_mask. |
700018e0 LZ |
8051 | * ndoms_new == 0 is a special case for destroying existing domains, |
8052 | * and it will not create the default domain. | |
dfb512ec | 8053 | * |
029190c5 PJ |
8054 | * Call with hotplug lock held |
8055 | */ | |
96f874e2 RR |
8056 | /* FIXME: Change to struct cpumask *doms_new[] */ |
8057 | void partition_sched_domains(int ndoms_new, struct cpumask *doms_new, | |
1d3504fc | 8058 | struct sched_domain_attr *dattr_new) |
029190c5 | 8059 | { |
dfb512ec | 8060 | int i, j, n; |
d65bd5ec | 8061 | int new_topology; |
029190c5 | 8062 | |
712555ee | 8063 | mutex_lock(&sched_domains_mutex); |
a1835615 | 8064 | |
7378547f MM |
8065 | /* always unregister in case we don't destroy any domains */ |
8066 | unregister_sched_domain_sysctl(); | |
8067 | ||
d65bd5ec HC |
8068 | /* Let architecture update cpu core mappings. */ |
8069 | new_topology = arch_update_cpu_topology(); | |
8070 | ||
dfb512ec | 8071 | n = doms_new ? ndoms_new : 0; |
029190c5 PJ |
8072 | |
8073 | /* Destroy deleted domains */ | |
8074 | for (i = 0; i < ndoms_cur; i++) { | |
d65bd5ec | 8075 | for (j = 0; j < n && !new_topology; j++) { |
96f874e2 | 8076 | if (cpumask_equal(&doms_cur[i], &doms_new[j]) |
1d3504fc | 8077 | && dattrs_equal(dattr_cur, i, dattr_new, j)) |
029190c5 PJ |
8078 | goto match1; |
8079 | } | |
8080 | /* no match - a current sched domain not in new doms_new[] */ | |
8081 | detach_destroy_domains(doms_cur + i); | |
8082 | match1: | |
8083 | ; | |
8084 | } | |
8085 | ||
e761b772 MK |
8086 | if (doms_new == NULL) { |
8087 | ndoms_cur = 0; | |
4212823f | 8088 | doms_new = fallback_doms; |
dcc30a35 | 8089 | cpumask_andnot(&doms_new[0], cpu_online_mask, cpu_isolated_map); |
faa2f98f | 8090 | WARN_ON_ONCE(dattr_new); |
e761b772 MK |
8091 | } |
8092 | ||
029190c5 PJ |
8093 | /* Build new domains */ |
8094 | for (i = 0; i < ndoms_new; i++) { | |
d65bd5ec | 8095 | for (j = 0; j < ndoms_cur && !new_topology; j++) { |
96f874e2 | 8096 | if (cpumask_equal(&doms_new[i], &doms_cur[j]) |
1d3504fc | 8097 | && dattrs_equal(dattr_new, i, dattr_cur, j)) |
029190c5 PJ |
8098 | goto match2; |
8099 | } | |
8100 | /* no match - add a new doms_new */ | |
1d3504fc HS |
8101 | __build_sched_domains(doms_new + i, |
8102 | dattr_new ? dattr_new + i : NULL); | |
029190c5 PJ |
8103 | match2: |
8104 | ; | |
8105 | } | |
8106 | ||
8107 | /* Remember the new sched domains */ | |
4212823f | 8108 | if (doms_cur != fallback_doms) |
029190c5 | 8109 | kfree(doms_cur); |
1d3504fc | 8110 | kfree(dattr_cur); /* kfree(NULL) is safe */ |
029190c5 | 8111 | doms_cur = doms_new; |
1d3504fc | 8112 | dattr_cur = dattr_new; |
029190c5 | 8113 | ndoms_cur = ndoms_new; |
7378547f MM |
8114 | |
8115 | register_sched_domain_sysctl(); | |
a1835615 | 8116 | |
712555ee | 8117 | mutex_unlock(&sched_domains_mutex); |
029190c5 PJ |
8118 | } |
8119 | ||
5c45bf27 | 8120 | #if defined(CONFIG_SCHED_MC) || defined(CONFIG_SCHED_SMT) |
c70f22d2 | 8121 | static void arch_reinit_sched_domains(void) |
5c45bf27 | 8122 | { |
95402b38 | 8123 | get_online_cpus(); |
dfb512ec MK |
8124 | |
8125 | /* Destroy domains first to force the rebuild */ | |
8126 | partition_sched_domains(0, NULL, NULL); | |
8127 | ||
e761b772 | 8128 | rebuild_sched_domains(); |
95402b38 | 8129 | put_online_cpus(); |
5c45bf27 SS |
8130 | } |
8131 | ||
8132 | static ssize_t sched_power_savings_store(const char *buf, size_t count, int smt) | |
8133 | { | |
afb8a9b7 | 8134 | unsigned int level = 0; |
5c45bf27 | 8135 | |
afb8a9b7 GS |
8136 | if (sscanf(buf, "%u", &level) != 1) |
8137 | return -EINVAL; | |
8138 | ||
8139 | /* | |
8140 | * level is always be positive so don't check for | |
8141 | * level < POWERSAVINGS_BALANCE_NONE which is 0 | |
8142 | * What happens on 0 or 1 byte write, | |
8143 | * need to check for count as well? | |
8144 | */ | |
8145 | ||
8146 | if (level >= MAX_POWERSAVINGS_BALANCE_LEVELS) | |
5c45bf27 SS |
8147 | return -EINVAL; |
8148 | ||
8149 | if (smt) | |
afb8a9b7 | 8150 | sched_smt_power_savings = level; |
5c45bf27 | 8151 | else |
afb8a9b7 | 8152 | sched_mc_power_savings = level; |
5c45bf27 | 8153 | |
c70f22d2 | 8154 | arch_reinit_sched_domains(); |
5c45bf27 | 8155 | |
c70f22d2 | 8156 | return count; |
5c45bf27 SS |
8157 | } |
8158 | ||
5c45bf27 | 8159 | #ifdef CONFIG_SCHED_MC |
f718cd4a AK |
8160 | static ssize_t sched_mc_power_savings_show(struct sysdev_class *class, |
8161 | char *page) | |
5c45bf27 SS |
8162 | { |
8163 | return sprintf(page, "%u\n", sched_mc_power_savings); | |
8164 | } | |
f718cd4a | 8165 | static ssize_t sched_mc_power_savings_store(struct sysdev_class *class, |
48f24c4d | 8166 | const char *buf, size_t count) |
5c45bf27 SS |
8167 | { |
8168 | return sched_power_savings_store(buf, count, 0); | |
8169 | } | |
f718cd4a AK |
8170 | static SYSDEV_CLASS_ATTR(sched_mc_power_savings, 0644, |
8171 | sched_mc_power_savings_show, | |
8172 | sched_mc_power_savings_store); | |
5c45bf27 SS |
8173 | #endif |
8174 | ||
8175 | #ifdef CONFIG_SCHED_SMT | |
f718cd4a AK |
8176 | static ssize_t sched_smt_power_savings_show(struct sysdev_class *dev, |
8177 | char *page) | |
5c45bf27 SS |
8178 | { |
8179 | return sprintf(page, "%u\n", sched_smt_power_savings); | |
8180 | } | |
f718cd4a | 8181 | static ssize_t sched_smt_power_savings_store(struct sysdev_class *dev, |
48f24c4d | 8182 | const char *buf, size_t count) |
5c45bf27 SS |
8183 | { |
8184 | return sched_power_savings_store(buf, count, 1); | |
8185 | } | |
f718cd4a AK |
8186 | static SYSDEV_CLASS_ATTR(sched_smt_power_savings, 0644, |
8187 | sched_smt_power_savings_show, | |
6707de00 AB |
8188 | sched_smt_power_savings_store); |
8189 | #endif | |
8190 | ||
39aac648 | 8191 | int __init sched_create_sysfs_power_savings_entries(struct sysdev_class *cls) |
6707de00 AB |
8192 | { |
8193 | int err = 0; | |
8194 | ||
8195 | #ifdef CONFIG_SCHED_SMT | |
8196 | if (smt_capable()) | |
8197 | err = sysfs_create_file(&cls->kset.kobj, | |
8198 | &attr_sched_smt_power_savings.attr); | |
8199 | #endif | |
8200 | #ifdef CONFIG_SCHED_MC | |
8201 | if (!err && mc_capable()) | |
8202 | err = sysfs_create_file(&cls->kset.kobj, | |
8203 | &attr_sched_mc_power_savings.attr); | |
8204 | #endif | |
8205 | return err; | |
8206 | } | |
6d6bc0ad | 8207 | #endif /* CONFIG_SCHED_MC || CONFIG_SCHED_SMT */ |
5c45bf27 | 8208 | |
e761b772 | 8209 | #ifndef CONFIG_CPUSETS |
1da177e4 | 8210 | /* |
e761b772 MK |
8211 | * Add online and remove offline CPUs from the scheduler domains. |
8212 | * When cpusets are enabled they take over this function. | |
1da177e4 LT |
8213 | */ |
8214 | static int update_sched_domains(struct notifier_block *nfb, | |
8215 | unsigned long action, void *hcpu) | |
e761b772 MK |
8216 | { |
8217 | switch (action) { | |
8218 | case CPU_ONLINE: | |
8219 | case CPU_ONLINE_FROZEN: | |
8220 | case CPU_DEAD: | |
8221 | case CPU_DEAD_FROZEN: | |
dfb512ec | 8222 | partition_sched_domains(1, NULL, NULL); |
e761b772 MK |
8223 | return NOTIFY_OK; |
8224 | ||
8225 | default: | |
8226 | return NOTIFY_DONE; | |
8227 | } | |
8228 | } | |
8229 | #endif | |
8230 | ||
8231 | static int update_runtime(struct notifier_block *nfb, | |
8232 | unsigned long action, void *hcpu) | |
1da177e4 | 8233 | { |
7def2be1 PZ |
8234 | int cpu = (int)(long)hcpu; |
8235 | ||
1da177e4 | 8236 | switch (action) { |
1da177e4 | 8237 | case CPU_DOWN_PREPARE: |
8bb78442 | 8238 | case CPU_DOWN_PREPARE_FROZEN: |
7def2be1 | 8239 | disable_runtime(cpu_rq(cpu)); |
1da177e4 LT |
8240 | return NOTIFY_OK; |
8241 | ||
1da177e4 | 8242 | case CPU_DOWN_FAILED: |
8bb78442 | 8243 | case CPU_DOWN_FAILED_FROZEN: |
1da177e4 | 8244 | case CPU_ONLINE: |
8bb78442 | 8245 | case CPU_ONLINE_FROZEN: |
7def2be1 | 8246 | enable_runtime(cpu_rq(cpu)); |
e761b772 MK |
8247 | return NOTIFY_OK; |
8248 | ||
1da177e4 LT |
8249 | default: |
8250 | return NOTIFY_DONE; | |
8251 | } | |
1da177e4 | 8252 | } |
1da177e4 LT |
8253 | |
8254 | void __init sched_init_smp(void) | |
8255 | { | |
dcc30a35 RR |
8256 | cpumask_var_t non_isolated_cpus; |
8257 | ||
8258 | alloc_cpumask_var(&non_isolated_cpus, GFP_KERNEL); | |
5c1e1767 | 8259 | |
434d53b0 MT |
8260 | #if defined(CONFIG_NUMA) |
8261 | sched_group_nodes_bycpu = kzalloc(nr_cpu_ids * sizeof(void **), | |
8262 | GFP_KERNEL); | |
8263 | BUG_ON(sched_group_nodes_bycpu == NULL); | |
8264 | #endif | |
95402b38 | 8265 | get_online_cpus(); |
712555ee | 8266 | mutex_lock(&sched_domains_mutex); |
dcc30a35 RR |
8267 | arch_init_sched_domains(cpu_online_mask); |
8268 | cpumask_andnot(non_isolated_cpus, cpu_possible_mask, cpu_isolated_map); | |
8269 | if (cpumask_empty(non_isolated_cpus)) | |
8270 | cpumask_set_cpu(smp_processor_id(), non_isolated_cpus); | |
712555ee | 8271 | mutex_unlock(&sched_domains_mutex); |
95402b38 | 8272 | put_online_cpus(); |
e761b772 MK |
8273 | |
8274 | #ifndef CONFIG_CPUSETS | |
1da177e4 LT |
8275 | /* XXX: Theoretical race here - CPU may be hotplugged now */ |
8276 | hotcpu_notifier(update_sched_domains, 0); | |
e761b772 MK |
8277 | #endif |
8278 | ||
8279 | /* RT runtime code needs to handle some hotplug events */ | |
8280 | hotcpu_notifier(update_runtime, 0); | |
8281 | ||
b328ca18 | 8282 | init_hrtick(); |
5c1e1767 NP |
8283 | |
8284 | /* Move init over to a non-isolated CPU */ | |
dcc30a35 | 8285 | if (set_cpus_allowed_ptr(current, non_isolated_cpus) < 0) |
5c1e1767 | 8286 | BUG(); |
19978ca6 | 8287 | sched_init_granularity(); |
dcc30a35 | 8288 | free_cpumask_var(non_isolated_cpus); |
4212823f RR |
8289 | |
8290 | alloc_cpumask_var(&fallback_doms, GFP_KERNEL); | |
0e3900e6 | 8291 | init_sched_rt_class(); |
1da177e4 LT |
8292 | } |
8293 | #else | |
8294 | void __init sched_init_smp(void) | |
8295 | { | |
19978ca6 | 8296 | sched_init_granularity(); |
1da177e4 LT |
8297 | } |
8298 | #endif /* CONFIG_SMP */ | |
8299 | ||
8300 | int in_sched_functions(unsigned long addr) | |
8301 | { | |
1da177e4 LT |
8302 | return in_lock_functions(addr) || |
8303 | (addr >= (unsigned long)__sched_text_start | |
8304 | && addr < (unsigned long)__sched_text_end); | |
8305 | } | |
8306 | ||
a9957449 | 8307 | static void init_cfs_rq(struct cfs_rq *cfs_rq, struct rq *rq) |
dd41f596 IM |
8308 | { |
8309 | cfs_rq->tasks_timeline = RB_ROOT; | |
4a55bd5e | 8310 | INIT_LIST_HEAD(&cfs_rq->tasks); |
dd41f596 IM |
8311 | #ifdef CONFIG_FAIR_GROUP_SCHED |
8312 | cfs_rq->rq = rq; | |
8313 | #endif | |
67e9fb2a | 8314 | cfs_rq->min_vruntime = (u64)(-(1LL << 20)); |
dd41f596 IM |
8315 | } |
8316 | ||
fa85ae24 PZ |
8317 | static void init_rt_rq(struct rt_rq *rt_rq, struct rq *rq) |
8318 | { | |
8319 | struct rt_prio_array *array; | |
8320 | int i; | |
8321 | ||
8322 | array = &rt_rq->active; | |
8323 | for (i = 0; i < MAX_RT_PRIO; i++) { | |
8324 | INIT_LIST_HEAD(array->queue + i); | |
8325 | __clear_bit(i, array->bitmap); | |
8326 | } | |
8327 | /* delimiter for bitsearch: */ | |
8328 | __set_bit(MAX_RT_PRIO, array->bitmap); | |
8329 | ||
052f1dc7 | 8330 | #if defined CONFIG_SMP || defined CONFIG_RT_GROUP_SCHED |
48d5e258 PZ |
8331 | rt_rq->highest_prio = MAX_RT_PRIO; |
8332 | #endif | |
fa85ae24 PZ |
8333 | #ifdef CONFIG_SMP |
8334 | rt_rq->rt_nr_migratory = 0; | |
fa85ae24 PZ |
8335 | rt_rq->overloaded = 0; |
8336 | #endif | |
8337 | ||
8338 | rt_rq->rt_time = 0; | |
8339 | rt_rq->rt_throttled = 0; | |
ac086bc2 PZ |
8340 | rt_rq->rt_runtime = 0; |
8341 | spin_lock_init(&rt_rq->rt_runtime_lock); | |
6f505b16 | 8342 | |
052f1dc7 | 8343 | #ifdef CONFIG_RT_GROUP_SCHED |
23b0fdfc | 8344 | rt_rq->rt_nr_boosted = 0; |
6f505b16 PZ |
8345 | rt_rq->rq = rq; |
8346 | #endif | |
fa85ae24 PZ |
8347 | } |
8348 | ||
6f505b16 | 8349 | #ifdef CONFIG_FAIR_GROUP_SCHED |
ec7dc8ac DG |
8350 | static void init_tg_cfs_entry(struct task_group *tg, struct cfs_rq *cfs_rq, |
8351 | struct sched_entity *se, int cpu, int add, | |
8352 | struct sched_entity *parent) | |
6f505b16 | 8353 | { |
ec7dc8ac | 8354 | struct rq *rq = cpu_rq(cpu); |
6f505b16 PZ |
8355 | tg->cfs_rq[cpu] = cfs_rq; |
8356 | init_cfs_rq(cfs_rq, rq); | |
8357 | cfs_rq->tg = tg; | |
8358 | if (add) | |
8359 | list_add(&cfs_rq->leaf_cfs_rq_list, &rq->leaf_cfs_rq_list); | |
8360 | ||
8361 | tg->se[cpu] = se; | |
354d60c2 DG |
8362 | /* se could be NULL for init_task_group */ |
8363 | if (!se) | |
8364 | return; | |
8365 | ||
ec7dc8ac DG |
8366 | if (!parent) |
8367 | se->cfs_rq = &rq->cfs; | |
8368 | else | |
8369 | se->cfs_rq = parent->my_q; | |
8370 | ||
6f505b16 PZ |
8371 | se->my_q = cfs_rq; |
8372 | se->load.weight = tg->shares; | |
e05510d0 | 8373 | se->load.inv_weight = 0; |
ec7dc8ac | 8374 | se->parent = parent; |
6f505b16 | 8375 | } |
052f1dc7 | 8376 | #endif |
6f505b16 | 8377 | |
052f1dc7 | 8378 | #ifdef CONFIG_RT_GROUP_SCHED |
ec7dc8ac DG |
8379 | static void init_tg_rt_entry(struct task_group *tg, struct rt_rq *rt_rq, |
8380 | struct sched_rt_entity *rt_se, int cpu, int add, | |
8381 | struct sched_rt_entity *parent) | |
6f505b16 | 8382 | { |
ec7dc8ac DG |
8383 | struct rq *rq = cpu_rq(cpu); |
8384 | ||
6f505b16 PZ |
8385 | tg->rt_rq[cpu] = rt_rq; |
8386 | init_rt_rq(rt_rq, rq); | |
8387 | rt_rq->tg = tg; | |
8388 | rt_rq->rt_se = rt_se; | |
ac086bc2 | 8389 | rt_rq->rt_runtime = tg->rt_bandwidth.rt_runtime; |
6f505b16 PZ |
8390 | if (add) |
8391 | list_add(&rt_rq->leaf_rt_rq_list, &rq->leaf_rt_rq_list); | |
8392 | ||
8393 | tg->rt_se[cpu] = rt_se; | |
354d60c2 DG |
8394 | if (!rt_se) |
8395 | return; | |
8396 | ||
ec7dc8ac DG |
8397 | if (!parent) |
8398 | rt_se->rt_rq = &rq->rt; | |
8399 | else | |
8400 | rt_se->rt_rq = parent->my_q; | |
8401 | ||
6f505b16 | 8402 | rt_se->my_q = rt_rq; |
ec7dc8ac | 8403 | rt_se->parent = parent; |
6f505b16 PZ |
8404 | INIT_LIST_HEAD(&rt_se->run_list); |
8405 | } | |
8406 | #endif | |
8407 | ||
1da177e4 LT |
8408 | void __init sched_init(void) |
8409 | { | |
dd41f596 | 8410 | int i, j; |
434d53b0 MT |
8411 | unsigned long alloc_size = 0, ptr; |
8412 | ||
8413 | #ifdef CONFIG_FAIR_GROUP_SCHED | |
8414 | alloc_size += 2 * nr_cpu_ids * sizeof(void **); | |
8415 | #endif | |
8416 | #ifdef CONFIG_RT_GROUP_SCHED | |
8417 | alloc_size += 2 * nr_cpu_ids * sizeof(void **); | |
eff766a6 PZ |
8418 | #endif |
8419 | #ifdef CONFIG_USER_SCHED | |
8420 | alloc_size *= 2; | |
434d53b0 MT |
8421 | #endif |
8422 | /* | |
8423 | * As sched_init() is called before page_alloc is setup, | |
8424 | * we use alloc_bootmem(). | |
8425 | */ | |
8426 | if (alloc_size) { | |
5a9d3225 | 8427 | ptr = (unsigned long)alloc_bootmem(alloc_size); |
434d53b0 MT |
8428 | |
8429 | #ifdef CONFIG_FAIR_GROUP_SCHED | |
8430 | init_task_group.se = (struct sched_entity **)ptr; | |
8431 | ptr += nr_cpu_ids * sizeof(void **); | |
8432 | ||
8433 | init_task_group.cfs_rq = (struct cfs_rq **)ptr; | |
8434 | ptr += nr_cpu_ids * sizeof(void **); | |
eff766a6 PZ |
8435 | |
8436 | #ifdef CONFIG_USER_SCHED | |
8437 | root_task_group.se = (struct sched_entity **)ptr; | |
8438 | ptr += nr_cpu_ids * sizeof(void **); | |
8439 | ||
8440 | root_task_group.cfs_rq = (struct cfs_rq **)ptr; | |
8441 | ptr += nr_cpu_ids * sizeof(void **); | |
6d6bc0ad DG |
8442 | #endif /* CONFIG_USER_SCHED */ |
8443 | #endif /* CONFIG_FAIR_GROUP_SCHED */ | |
434d53b0 MT |
8444 | #ifdef CONFIG_RT_GROUP_SCHED |
8445 | init_task_group.rt_se = (struct sched_rt_entity **)ptr; | |
8446 | ptr += nr_cpu_ids * sizeof(void **); | |
8447 | ||
8448 | init_task_group.rt_rq = (struct rt_rq **)ptr; | |
eff766a6 PZ |
8449 | ptr += nr_cpu_ids * sizeof(void **); |
8450 | ||
8451 | #ifdef CONFIG_USER_SCHED | |
8452 | root_task_group.rt_se = (struct sched_rt_entity **)ptr; | |
8453 | ptr += nr_cpu_ids * sizeof(void **); | |
8454 | ||
8455 | root_task_group.rt_rq = (struct rt_rq **)ptr; | |
8456 | ptr += nr_cpu_ids * sizeof(void **); | |
6d6bc0ad DG |
8457 | #endif /* CONFIG_USER_SCHED */ |
8458 | #endif /* CONFIG_RT_GROUP_SCHED */ | |
434d53b0 | 8459 | } |
dd41f596 | 8460 | |
57d885fe GH |
8461 | #ifdef CONFIG_SMP |
8462 | init_defrootdomain(); | |
8463 | #endif | |
8464 | ||
d0b27fa7 PZ |
8465 | init_rt_bandwidth(&def_rt_bandwidth, |
8466 | global_rt_period(), global_rt_runtime()); | |
8467 | ||
8468 | #ifdef CONFIG_RT_GROUP_SCHED | |
8469 | init_rt_bandwidth(&init_task_group.rt_bandwidth, | |
8470 | global_rt_period(), global_rt_runtime()); | |
eff766a6 PZ |
8471 | #ifdef CONFIG_USER_SCHED |
8472 | init_rt_bandwidth(&root_task_group.rt_bandwidth, | |
8473 | global_rt_period(), RUNTIME_INF); | |
6d6bc0ad DG |
8474 | #endif /* CONFIG_USER_SCHED */ |
8475 | #endif /* CONFIG_RT_GROUP_SCHED */ | |
d0b27fa7 | 8476 | |
052f1dc7 | 8477 | #ifdef CONFIG_GROUP_SCHED |
6f505b16 | 8478 | list_add(&init_task_group.list, &task_groups); |
f473aa5e PZ |
8479 | INIT_LIST_HEAD(&init_task_group.children); |
8480 | ||
8481 | #ifdef CONFIG_USER_SCHED | |
8482 | INIT_LIST_HEAD(&root_task_group.children); | |
8483 | init_task_group.parent = &root_task_group; | |
8484 | list_add(&init_task_group.siblings, &root_task_group.children); | |
6d6bc0ad DG |
8485 | #endif /* CONFIG_USER_SCHED */ |
8486 | #endif /* CONFIG_GROUP_SCHED */ | |
6f505b16 | 8487 | |
0a945022 | 8488 | for_each_possible_cpu(i) { |
70b97a7f | 8489 | struct rq *rq; |
1da177e4 LT |
8490 | |
8491 | rq = cpu_rq(i); | |
8492 | spin_lock_init(&rq->lock); | |
7897986b | 8493 | rq->nr_running = 0; |
dd41f596 | 8494 | init_cfs_rq(&rq->cfs, rq); |
6f505b16 | 8495 | init_rt_rq(&rq->rt, rq); |
dd41f596 | 8496 | #ifdef CONFIG_FAIR_GROUP_SCHED |
4cf86d77 | 8497 | init_task_group.shares = init_task_group_load; |
6f505b16 | 8498 | INIT_LIST_HEAD(&rq->leaf_cfs_rq_list); |
354d60c2 DG |
8499 | #ifdef CONFIG_CGROUP_SCHED |
8500 | /* | |
8501 | * How much cpu bandwidth does init_task_group get? | |
8502 | * | |
8503 | * In case of task-groups formed thr' the cgroup filesystem, it | |
8504 | * gets 100% of the cpu resources in the system. This overall | |
8505 | * system cpu resource is divided among the tasks of | |
8506 | * init_task_group and its child task-groups in a fair manner, | |
8507 | * based on each entity's (task or task-group's) weight | |
8508 | * (se->load.weight). | |
8509 | * | |
8510 | * In other words, if init_task_group has 10 tasks of weight | |
8511 | * 1024) and two child groups A0 and A1 (of weight 1024 each), | |
8512 | * then A0's share of the cpu resource is: | |
8513 | * | |
8514 | * A0's bandwidth = 1024 / (10*1024 + 1024 + 1024) = 8.33% | |
8515 | * | |
8516 | * We achieve this by letting init_task_group's tasks sit | |
8517 | * directly in rq->cfs (i.e init_task_group->se[] = NULL). | |
8518 | */ | |
ec7dc8ac | 8519 | init_tg_cfs_entry(&init_task_group, &rq->cfs, NULL, i, 1, NULL); |
354d60c2 | 8520 | #elif defined CONFIG_USER_SCHED |
eff766a6 PZ |
8521 | root_task_group.shares = NICE_0_LOAD; |
8522 | init_tg_cfs_entry(&root_task_group, &rq->cfs, NULL, i, 0, NULL); | |
354d60c2 DG |
8523 | /* |
8524 | * In case of task-groups formed thr' the user id of tasks, | |
8525 | * init_task_group represents tasks belonging to root user. | |
8526 | * Hence it forms a sibling of all subsequent groups formed. | |
8527 | * In this case, init_task_group gets only a fraction of overall | |
8528 | * system cpu resource, based on the weight assigned to root | |
8529 | * user's cpu share (INIT_TASK_GROUP_LOAD). This is accomplished | |
8530 | * by letting tasks of init_task_group sit in a separate cfs_rq | |
8531 | * (init_cfs_rq) and having one entity represent this group of | |
8532 | * tasks in rq->cfs (i.e init_task_group->se[] != NULL). | |
8533 | */ | |
ec7dc8ac | 8534 | init_tg_cfs_entry(&init_task_group, |
6f505b16 | 8535 | &per_cpu(init_cfs_rq, i), |
eff766a6 PZ |
8536 | &per_cpu(init_sched_entity, i), i, 1, |
8537 | root_task_group.se[i]); | |
6f505b16 | 8538 | |
052f1dc7 | 8539 | #endif |
354d60c2 DG |
8540 | #endif /* CONFIG_FAIR_GROUP_SCHED */ |
8541 | ||
8542 | rq->rt.rt_runtime = def_rt_bandwidth.rt_runtime; | |
052f1dc7 | 8543 | #ifdef CONFIG_RT_GROUP_SCHED |
6f505b16 | 8544 | INIT_LIST_HEAD(&rq->leaf_rt_rq_list); |
354d60c2 | 8545 | #ifdef CONFIG_CGROUP_SCHED |
ec7dc8ac | 8546 | init_tg_rt_entry(&init_task_group, &rq->rt, NULL, i, 1, NULL); |
354d60c2 | 8547 | #elif defined CONFIG_USER_SCHED |
eff766a6 | 8548 | init_tg_rt_entry(&root_task_group, &rq->rt, NULL, i, 0, NULL); |
ec7dc8ac | 8549 | init_tg_rt_entry(&init_task_group, |
6f505b16 | 8550 | &per_cpu(init_rt_rq, i), |
eff766a6 PZ |
8551 | &per_cpu(init_sched_rt_entity, i), i, 1, |
8552 | root_task_group.rt_se[i]); | |
354d60c2 | 8553 | #endif |
dd41f596 | 8554 | #endif |
1da177e4 | 8555 | |
dd41f596 IM |
8556 | for (j = 0; j < CPU_LOAD_IDX_MAX; j++) |
8557 | rq->cpu_load[j] = 0; | |
1da177e4 | 8558 | #ifdef CONFIG_SMP |
41c7ce9a | 8559 | rq->sd = NULL; |
57d885fe | 8560 | rq->rd = NULL; |
1da177e4 | 8561 | rq->active_balance = 0; |
dd41f596 | 8562 | rq->next_balance = jiffies; |
1da177e4 | 8563 | rq->push_cpu = 0; |
0a2966b4 | 8564 | rq->cpu = i; |
1f11eb6a | 8565 | rq->online = 0; |
1da177e4 LT |
8566 | rq->migration_thread = NULL; |
8567 | INIT_LIST_HEAD(&rq->migration_queue); | |
dc938520 | 8568 | rq_attach_root(rq, &def_root_domain); |
1da177e4 | 8569 | #endif |
8f4d37ec | 8570 | init_rq_hrtick(rq); |
1da177e4 | 8571 | atomic_set(&rq->nr_iowait, 0); |
1da177e4 LT |
8572 | } |
8573 | ||
2dd73a4f | 8574 | set_load_weight(&init_task); |
b50f60ce | 8575 | |
e107be36 AK |
8576 | #ifdef CONFIG_PREEMPT_NOTIFIERS |
8577 | INIT_HLIST_HEAD(&init_task.preempt_notifiers); | |
8578 | #endif | |
8579 | ||
c9819f45 | 8580 | #ifdef CONFIG_SMP |
962cf36c | 8581 | open_softirq(SCHED_SOFTIRQ, run_rebalance_domains); |
c9819f45 CL |
8582 | #endif |
8583 | ||
b50f60ce HC |
8584 | #ifdef CONFIG_RT_MUTEXES |
8585 | plist_head_init(&init_task.pi_waiters, &init_task.pi_lock); | |
8586 | #endif | |
8587 | ||
1da177e4 LT |
8588 | /* |
8589 | * The boot idle thread does lazy MMU switching as well: | |
8590 | */ | |
8591 | atomic_inc(&init_mm.mm_count); | |
8592 | enter_lazy_tlb(&init_mm, current); | |
8593 | ||
8594 | /* | |
8595 | * Make us the idle thread. Technically, schedule() should not be | |
8596 | * called from this thread, however somewhere below it might be, | |
8597 | * but because we are the idle thread, we just pick up running again | |
8598 | * when this runqueue becomes "idle". | |
8599 | */ | |
8600 | init_idle(current, smp_processor_id()); | |
dd41f596 IM |
8601 | /* |
8602 | * During early bootup we pretend to be a normal task: | |
8603 | */ | |
8604 | current->sched_class = &fair_sched_class; | |
6892b75e | 8605 | |
6a7b3dc3 RR |
8606 | /* Allocate the nohz_cpu_mask if CONFIG_CPUMASK_OFFSTACK */ |
8607 | alloc_bootmem_cpumask_var(&nohz_cpu_mask); | |
bf4d83f6 | 8608 | #ifdef CONFIG_SMP |
7d1e6a9b RR |
8609 | #ifdef CONFIG_NO_HZ |
8610 | alloc_bootmem_cpumask_var(&nohz.cpu_mask); | |
8611 | #endif | |
dcc30a35 | 8612 | alloc_bootmem_cpumask_var(&cpu_isolated_map); |
bf4d83f6 | 8613 | #endif /* SMP */ |
6a7b3dc3 | 8614 | |
6892b75e | 8615 | scheduler_running = 1; |
1da177e4 LT |
8616 | } |
8617 | ||
8618 | #ifdef CONFIG_DEBUG_SPINLOCK_SLEEP | |
8619 | void __might_sleep(char *file, int line) | |
8620 | { | |
48f24c4d | 8621 | #ifdef in_atomic |
1da177e4 LT |
8622 | static unsigned long prev_jiffy; /* ratelimiting */ |
8623 | ||
aef745fc IM |
8624 | if ((!in_atomic() && !irqs_disabled()) || |
8625 | system_state != SYSTEM_RUNNING || oops_in_progress) | |
8626 | return; | |
8627 | if (time_before(jiffies, prev_jiffy + HZ) && prev_jiffy) | |
8628 | return; | |
8629 | prev_jiffy = jiffies; | |
8630 | ||
8631 | printk(KERN_ERR | |
8632 | "BUG: sleeping function called from invalid context at %s:%d\n", | |
8633 | file, line); | |
8634 | printk(KERN_ERR | |
8635 | "in_atomic(): %d, irqs_disabled(): %d, pid: %d, name: %s\n", | |
8636 | in_atomic(), irqs_disabled(), | |
8637 | current->pid, current->comm); | |
8638 | ||
8639 | debug_show_held_locks(current); | |
8640 | if (irqs_disabled()) | |
8641 | print_irqtrace_events(current); | |
8642 | dump_stack(); | |
1da177e4 LT |
8643 | #endif |
8644 | } | |
8645 | EXPORT_SYMBOL(__might_sleep); | |
8646 | #endif | |
8647 | ||
8648 | #ifdef CONFIG_MAGIC_SYSRQ | |
3a5e4dc1 AK |
8649 | static void normalize_task(struct rq *rq, struct task_struct *p) |
8650 | { | |
8651 | int on_rq; | |
3e51f33f | 8652 | |
3a5e4dc1 AK |
8653 | update_rq_clock(rq); |
8654 | on_rq = p->se.on_rq; | |
8655 | if (on_rq) | |
8656 | deactivate_task(rq, p, 0); | |
8657 | __setscheduler(rq, p, SCHED_NORMAL, 0); | |
8658 | if (on_rq) { | |
8659 | activate_task(rq, p, 0); | |
8660 | resched_task(rq->curr); | |
8661 | } | |
8662 | } | |
8663 | ||
1da177e4 LT |
8664 | void normalize_rt_tasks(void) |
8665 | { | |
a0f98a1c | 8666 | struct task_struct *g, *p; |
1da177e4 | 8667 | unsigned long flags; |
70b97a7f | 8668 | struct rq *rq; |
1da177e4 | 8669 | |
4cf5d77a | 8670 | read_lock_irqsave(&tasklist_lock, flags); |
a0f98a1c | 8671 | do_each_thread(g, p) { |
178be793 IM |
8672 | /* |
8673 | * Only normalize user tasks: | |
8674 | */ | |
8675 | if (!p->mm) | |
8676 | continue; | |
8677 | ||
6cfb0d5d | 8678 | p->se.exec_start = 0; |
6cfb0d5d | 8679 | #ifdef CONFIG_SCHEDSTATS |
dd41f596 | 8680 | p->se.wait_start = 0; |
dd41f596 | 8681 | p->se.sleep_start = 0; |
dd41f596 | 8682 | p->se.block_start = 0; |
6cfb0d5d | 8683 | #endif |
dd41f596 IM |
8684 | |
8685 | if (!rt_task(p)) { | |
8686 | /* | |
8687 | * Renice negative nice level userspace | |
8688 | * tasks back to 0: | |
8689 | */ | |
8690 | if (TASK_NICE(p) < 0 && p->mm) | |
8691 | set_user_nice(p, 0); | |
1da177e4 | 8692 | continue; |
dd41f596 | 8693 | } |
1da177e4 | 8694 | |
4cf5d77a | 8695 | spin_lock(&p->pi_lock); |
b29739f9 | 8696 | rq = __task_rq_lock(p); |
1da177e4 | 8697 | |
178be793 | 8698 | normalize_task(rq, p); |
3a5e4dc1 | 8699 | |
b29739f9 | 8700 | __task_rq_unlock(rq); |
4cf5d77a | 8701 | spin_unlock(&p->pi_lock); |
a0f98a1c IM |
8702 | } while_each_thread(g, p); |
8703 | ||
4cf5d77a | 8704 | read_unlock_irqrestore(&tasklist_lock, flags); |
1da177e4 LT |
8705 | } |
8706 | ||
8707 | #endif /* CONFIG_MAGIC_SYSRQ */ | |
1df5c10a LT |
8708 | |
8709 | #ifdef CONFIG_IA64 | |
8710 | /* | |
8711 | * These functions are only useful for the IA64 MCA handling. | |
8712 | * | |
8713 | * They can only be called when the whole system has been | |
8714 | * stopped - every CPU needs to be quiescent, and no scheduling | |
8715 | * activity can take place. Using them for anything else would | |
8716 | * be a serious bug, and as a result, they aren't even visible | |
8717 | * under any other configuration. | |
8718 | */ | |
8719 | ||
8720 | /** | |
8721 | * curr_task - return the current task for a given cpu. | |
8722 | * @cpu: the processor in question. | |
8723 | * | |
8724 | * ONLY VALID WHEN THE WHOLE SYSTEM IS STOPPED! | |
8725 | */ | |
36c8b586 | 8726 | struct task_struct *curr_task(int cpu) |
1df5c10a LT |
8727 | { |
8728 | return cpu_curr(cpu); | |
8729 | } | |
8730 | ||
8731 | /** | |
8732 | * set_curr_task - set the current task for a given cpu. | |
8733 | * @cpu: the processor in question. | |
8734 | * @p: the task pointer to set. | |
8735 | * | |
8736 | * Description: This function must only be used when non-maskable interrupts | |
41a2d6cf IM |
8737 | * are serviced on a separate stack. It allows the architecture to switch the |
8738 | * notion of the current task on a cpu in a non-blocking manner. This function | |
1df5c10a LT |
8739 | * must be called with all CPU's synchronized, and interrupts disabled, the |
8740 | * and caller must save the original value of the current task (see | |
8741 | * curr_task() above) and restore that value before reenabling interrupts and | |
8742 | * re-starting the system. | |
8743 | * | |
8744 | * ONLY VALID WHEN THE WHOLE SYSTEM IS STOPPED! | |
8745 | */ | |
36c8b586 | 8746 | void set_curr_task(int cpu, struct task_struct *p) |
1df5c10a LT |
8747 | { |
8748 | cpu_curr(cpu) = p; | |
8749 | } | |
8750 | ||
8751 | #endif | |
29f59db3 | 8752 | |
bccbe08a PZ |
8753 | #ifdef CONFIG_FAIR_GROUP_SCHED |
8754 | static void free_fair_sched_group(struct task_group *tg) | |
6f505b16 PZ |
8755 | { |
8756 | int i; | |
8757 | ||
8758 | for_each_possible_cpu(i) { | |
8759 | if (tg->cfs_rq) | |
8760 | kfree(tg->cfs_rq[i]); | |
8761 | if (tg->se) | |
8762 | kfree(tg->se[i]); | |
6f505b16 PZ |
8763 | } |
8764 | ||
8765 | kfree(tg->cfs_rq); | |
8766 | kfree(tg->se); | |
6f505b16 PZ |
8767 | } |
8768 | ||
ec7dc8ac DG |
8769 | static |
8770 | int alloc_fair_sched_group(struct task_group *tg, struct task_group *parent) | |
29f59db3 | 8771 | { |
29f59db3 | 8772 | struct cfs_rq *cfs_rq; |
eab17229 | 8773 | struct sched_entity *se; |
9b5b7751 | 8774 | struct rq *rq; |
29f59db3 SV |
8775 | int i; |
8776 | ||
434d53b0 | 8777 | tg->cfs_rq = kzalloc(sizeof(cfs_rq) * nr_cpu_ids, GFP_KERNEL); |
29f59db3 SV |
8778 | if (!tg->cfs_rq) |
8779 | goto err; | |
434d53b0 | 8780 | tg->se = kzalloc(sizeof(se) * nr_cpu_ids, GFP_KERNEL); |
29f59db3 SV |
8781 | if (!tg->se) |
8782 | goto err; | |
052f1dc7 PZ |
8783 | |
8784 | tg->shares = NICE_0_LOAD; | |
29f59db3 SV |
8785 | |
8786 | for_each_possible_cpu(i) { | |
9b5b7751 | 8787 | rq = cpu_rq(i); |
29f59db3 | 8788 | |
eab17229 LZ |
8789 | cfs_rq = kzalloc_node(sizeof(struct cfs_rq), |
8790 | GFP_KERNEL, cpu_to_node(i)); | |
29f59db3 SV |
8791 | if (!cfs_rq) |
8792 | goto err; | |
8793 | ||
eab17229 LZ |
8794 | se = kzalloc_node(sizeof(struct sched_entity), |
8795 | GFP_KERNEL, cpu_to_node(i)); | |
29f59db3 SV |
8796 | if (!se) |
8797 | goto err; | |
8798 | ||
eab17229 | 8799 | init_tg_cfs_entry(tg, cfs_rq, se, i, 0, parent->se[i]); |
bccbe08a PZ |
8800 | } |
8801 | ||
8802 | return 1; | |
8803 | ||
8804 | err: | |
8805 | return 0; | |
8806 | } | |
8807 | ||
8808 | static inline void register_fair_sched_group(struct task_group *tg, int cpu) | |
8809 | { | |
8810 | list_add_rcu(&tg->cfs_rq[cpu]->leaf_cfs_rq_list, | |
8811 | &cpu_rq(cpu)->leaf_cfs_rq_list); | |
8812 | } | |
8813 | ||
8814 | static inline void unregister_fair_sched_group(struct task_group *tg, int cpu) | |
8815 | { | |
8816 | list_del_rcu(&tg->cfs_rq[cpu]->leaf_cfs_rq_list); | |
8817 | } | |
6d6bc0ad | 8818 | #else /* !CONFG_FAIR_GROUP_SCHED */ |
bccbe08a PZ |
8819 | static inline void free_fair_sched_group(struct task_group *tg) |
8820 | { | |
8821 | } | |
8822 | ||
ec7dc8ac DG |
8823 | static inline |
8824 | int alloc_fair_sched_group(struct task_group *tg, struct task_group *parent) | |
bccbe08a PZ |
8825 | { |
8826 | return 1; | |
8827 | } | |
8828 | ||
8829 | static inline void register_fair_sched_group(struct task_group *tg, int cpu) | |
8830 | { | |
8831 | } | |
8832 | ||
8833 | static inline void unregister_fair_sched_group(struct task_group *tg, int cpu) | |
8834 | { | |
8835 | } | |
6d6bc0ad | 8836 | #endif /* CONFIG_FAIR_GROUP_SCHED */ |
052f1dc7 PZ |
8837 | |
8838 | #ifdef CONFIG_RT_GROUP_SCHED | |
bccbe08a PZ |
8839 | static void free_rt_sched_group(struct task_group *tg) |
8840 | { | |
8841 | int i; | |
8842 | ||
d0b27fa7 PZ |
8843 | destroy_rt_bandwidth(&tg->rt_bandwidth); |
8844 | ||
bccbe08a PZ |
8845 | for_each_possible_cpu(i) { |
8846 | if (tg->rt_rq) | |
8847 | kfree(tg->rt_rq[i]); | |
8848 | if (tg->rt_se) | |
8849 | kfree(tg->rt_se[i]); | |
8850 | } | |
8851 | ||
8852 | kfree(tg->rt_rq); | |
8853 | kfree(tg->rt_se); | |
8854 | } | |
8855 | ||
ec7dc8ac DG |
8856 | static |
8857 | int alloc_rt_sched_group(struct task_group *tg, struct task_group *parent) | |
bccbe08a PZ |
8858 | { |
8859 | struct rt_rq *rt_rq; | |
eab17229 | 8860 | struct sched_rt_entity *rt_se; |
bccbe08a PZ |
8861 | struct rq *rq; |
8862 | int i; | |
8863 | ||
434d53b0 | 8864 | tg->rt_rq = kzalloc(sizeof(rt_rq) * nr_cpu_ids, GFP_KERNEL); |
bccbe08a PZ |
8865 | if (!tg->rt_rq) |
8866 | goto err; | |
434d53b0 | 8867 | tg->rt_se = kzalloc(sizeof(rt_se) * nr_cpu_ids, GFP_KERNEL); |
bccbe08a PZ |
8868 | if (!tg->rt_se) |
8869 | goto err; | |
8870 | ||
d0b27fa7 PZ |
8871 | init_rt_bandwidth(&tg->rt_bandwidth, |
8872 | ktime_to_ns(def_rt_bandwidth.rt_period), 0); | |
bccbe08a PZ |
8873 | |
8874 | for_each_possible_cpu(i) { | |
8875 | rq = cpu_rq(i); | |
8876 | ||
eab17229 LZ |
8877 | rt_rq = kzalloc_node(sizeof(struct rt_rq), |
8878 | GFP_KERNEL, cpu_to_node(i)); | |
6f505b16 PZ |
8879 | if (!rt_rq) |
8880 | goto err; | |
29f59db3 | 8881 | |
eab17229 LZ |
8882 | rt_se = kzalloc_node(sizeof(struct sched_rt_entity), |
8883 | GFP_KERNEL, cpu_to_node(i)); | |
6f505b16 PZ |
8884 | if (!rt_se) |
8885 | goto err; | |
29f59db3 | 8886 | |
eab17229 | 8887 | init_tg_rt_entry(tg, rt_rq, rt_se, i, 0, parent->rt_se[i]); |
29f59db3 SV |
8888 | } |
8889 | ||
bccbe08a PZ |
8890 | return 1; |
8891 | ||
8892 | err: | |
8893 | return 0; | |
8894 | } | |
8895 | ||
8896 | static inline void register_rt_sched_group(struct task_group *tg, int cpu) | |
8897 | { | |
8898 | list_add_rcu(&tg->rt_rq[cpu]->leaf_rt_rq_list, | |
8899 | &cpu_rq(cpu)->leaf_rt_rq_list); | |
8900 | } | |
8901 | ||
8902 | static inline void unregister_rt_sched_group(struct task_group *tg, int cpu) | |
8903 | { | |
8904 | list_del_rcu(&tg->rt_rq[cpu]->leaf_rt_rq_list); | |
8905 | } | |
6d6bc0ad | 8906 | #else /* !CONFIG_RT_GROUP_SCHED */ |
bccbe08a PZ |
8907 | static inline void free_rt_sched_group(struct task_group *tg) |
8908 | { | |
8909 | } | |
8910 | ||
ec7dc8ac DG |
8911 | static inline |
8912 | int alloc_rt_sched_group(struct task_group *tg, struct task_group *parent) | |
bccbe08a PZ |
8913 | { |
8914 | return 1; | |
8915 | } | |
8916 | ||
8917 | static inline void register_rt_sched_group(struct task_group *tg, int cpu) | |
8918 | { | |
8919 | } | |
8920 | ||
8921 | static inline void unregister_rt_sched_group(struct task_group *tg, int cpu) | |
8922 | { | |
8923 | } | |
6d6bc0ad | 8924 | #endif /* CONFIG_RT_GROUP_SCHED */ |
bccbe08a | 8925 | |
d0b27fa7 | 8926 | #ifdef CONFIG_GROUP_SCHED |
bccbe08a PZ |
8927 | static void free_sched_group(struct task_group *tg) |
8928 | { | |
8929 | free_fair_sched_group(tg); | |
8930 | free_rt_sched_group(tg); | |
8931 | kfree(tg); | |
8932 | } | |
8933 | ||
8934 | /* allocate runqueue etc for a new task group */ | |
ec7dc8ac | 8935 | struct task_group *sched_create_group(struct task_group *parent) |
bccbe08a PZ |
8936 | { |
8937 | struct task_group *tg; | |
8938 | unsigned long flags; | |
8939 | int i; | |
8940 | ||
8941 | tg = kzalloc(sizeof(*tg), GFP_KERNEL); | |
8942 | if (!tg) | |
8943 | return ERR_PTR(-ENOMEM); | |
8944 | ||
ec7dc8ac | 8945 | if (!alloc_fair_sched_group(tg, parent)) |
bccbe08a PZ |
8946 | goto err; |
8947 | ||
ec7dc8ac | 8948 | if (!alloc_rt_sched_group(tg, parent)) |
bccbe08a PZ |
8949 | goto err; |
8950 | ||
8ed36996 | 8951 | spin_lock_irqsave(&task_group_lock, flags); |
9b5b7751 | 8952 | for_each_possible_cpu(i) { |
bccbe08a PZ |
8953 | register_fair_sched_group(tg, i); |
8954 | register_rt_sched_group(tg, i); | |
9b5b7751 | 8955 | } |
6f505b16 | 8956 | list_add_rcu(&tg->list, &task_groups); |
f473aa5e PZ |
8957 | |
8958 | WARN_ON(!parent); /* root should already exist */ | |
8959 | ||
8960 | tg->parent = parent; | |
f473aa5e | 8961 | INIT_LIST_HEAD(&tg->children); |
09f2724a | 8962 | list_add_rcu(&tg->siblings, &parent->children); |
8ed36996 | 8963 | spin_unlock_irqrestore(&task_group_lock, flags); |
29f59db3 | 8964 | |
9b5b7751 | 8965 | return tg; |
29f59db3 SV |
8966 | |
8967 | err: | |
6f505b16 | 8968 | free_sched_group(tg); |
29f59db3 SV |
8969 | return ERR_PTR(-ENOMEM); |
8970 | } | |
8971 | ||
9b5b7751 | 8972 | /* rcu callback to free various structures associated with a task group */ |
6f505b16 | 8973 | static void free_sched_group_rcu(struct rcu_head *rhp) |
29f59db3 | 8974 | { |
29f59db3 | 8975 | /* now it should be safe to free those cfs_rqs */ |
6f505b16 | 8976 | free_sched_group(container_of(rhp, struct task_group, rcu)); |
29f59db3 SV |
8977 | } |
8978 | ||
9b5b7751 | 8979 | /* Destroy runqueue etc associated with a task group */ |
4cf86d77 | 8980 | void sched_destroy_group(struct task_group *tg) |
29f59db3 | 8981 | { |
8ed36996 | 8982 | unsigned long flags; |
9b5b7751 | 8983 | int i; |
29f59db3 | 8984 | |
8ed36996 | 8985 | spin_lock_irqsave(&task_group_lock, flags); |
9b5b7751 | 8986 | for_each_possible_cpu(i) { |
bccbe08a PZ |
8987 | unregister_fair_sched_group(tg, i); |
8988 | unregister_rt_sched_group(tg, i); | |
9b5b7751 | 8989 | } |
6f505b16 | 8990 | list_del_rcu(&tg->list); |
f473aa5e | 8991 | list_del_rcu(&tg->siblings); |
8ed36996 | 8992 | spin_unlock_irqrestore(&task_group_lock, flags); |
9b5b7751 | 8993 | |
9b5b7751 | 8994 | /* wait for possible concurrent references to cfs_rqs complete */ |
6f505b16 | 8995 | call_rcu(&tg->rcu, free_sched_group_rcu); |
29f59db3 SV |
8996 | } |
8997 | ||
9b5b7751 | 8998 | /* change task's runqueue when it moves between groups. |
3a252015 IM |
8999 | * The caller of this function should have put the task in its new group |
9000 | * by now. This function just updates tsk->se.cfs_rq and tsk->se.parent to | |
9001 | * reflect its new group. | |
9b5b7751 SV |
9002 | */ |
9003 | void sched_move_task(struct task_struct *tsk) | |
29f59db3 SV |
9004 | { |
9005 | int on_rq, running; | |
9006 | unsigned long flags; | |
9007 | struct rq *rq; | |
9008 | ||
9009 | rq = task_rq_lock(tsk, &flags); | |
9010 | ||
29f59db3 SV |
9011 | update_rq_clock(rq); |
9012 | ||
051a1d1a | 9013 | running = task_current(rq, tsk); |
29f59db3 SV |
9014 | on_rq = tsk->se.on_rq; |
9015 | ||
0e1f3483 | 9016 | if (on_rq) |
29f59db3 | 9017 | dequeue_task(rq, tsk, 0); |
0e1f3483 HS |
9018 | if (unlikely(running)) |
9019 | tsk->sched_class->put_prev_task(rq, tsk); | |
29f59db3 | 9020 | |
6f505b16 | 9021 | set_task_rq(tsk, task_cpu(tsk)); |
29f59db3 | 9022 | |
810b3817 PZ |
9023 | #ifdef CONFIG_FAIR_GROUP_SCHED |
9024 | if (tsk->sched_class->moved_group) | |
9025 | tsk->sched_class->moved_group(tsk); | |
9026 | #endif | |
9027 | ||
0e1f3483 HS |
9028 | if (unlikely(running)) |
9029 | tsk->sched_class->set_curr_task(rq); | |
9030 | if (on_rq) | |
7074badb | 9031 | enqueue_task(rq, tsk, 0); |
29f59db3 | 9032 | |
29f59db3 SV |
9033 | task_rq_unlock(rq, &flags); |
9034 | } | |
6d6bc0ad | 9035 | #endif /* CONFIG_GROUP_SCHED */ |
29f59db3 | 9036 | |
052f1dc7 | 9037 | #ifdef CONFIG_FAIR_GROUP_SCHED |
c09595f6 | 9038 | static void __set_se_shares(struct sched_entity *se, unsigned long shares) |
29f59db3 SV |
9039 | { |
9040 | struct cfs_rq *cfs_rq = se->cfs_rq; | |
29f59db3 SV |
9041 | int on_rq; |
9042 | ||
29f59db3 | 9043 | on_rq = se->on_rq; |
62fb1851 | 9044 | if (on_rq) |
29f59db3 SV |
9045 | dequeue_entity(cfs_rq, se, 0); |
9046 | ||
9047 | se->load.weight = shares; | |
e05510d0 | 9048 | se->load.inv_weight = 0; |
29f59db3 | 9049 | |
62fb1851 | 9050 | if (on_rq) |
29f59db3 | 9051 | enqueue_entity(cfs_rq, se, 0); |
c09595f6 | 9052 | } |
62fb1851 | 9053 | |
c09595f6 PZ |
9054 | static void set_se_shares(struct sched_entity *se, unsigned long shares) |
9055 | { | |
9056 | struct cfs_rq *cfs_rq = se->cfs_rq; | |
9057 | struct rq *rq = cfs_rq->rq; | |
9058 | unsigned long flags; | |
9059 | ||
9060 | spin_lock_irqsave(&rq->lock, flags); | |
9061 | __set_se_shares(se, shares); | |
9062 | spin_unlock_irqrestore(&rq->lock, flags); | |
29f59db3 SV |
9063 | } |
9064 | ||
8ed36996 PZ |
9065 | static DEFINE_MUTEX(shares_mutex); |
9066 | ||
4cf86d77 | 9067 | int sched_group_set_shares(struct task_group *tg, unsigned long shares) |
29f59db3 SV |
9068 | { |
9069 | int i; | |
8ed36996 | 9070 | unsigned long flags; |
c61935fd | 9071 | |
ec7dc8ac DG |
9072 | /* |
9073 | * We can't change the weight of the root cgroup. | |
9074 | */ | |
9075 | if (!tg->se[0]) | |
9076 | return -EINVAL; | |
9077 | ||
18d95a28 PZ |
9078 | if (shares < MIN_SHARES) |
9079 | shares = MIN_SHARES; | |
cb4ad1ff MX |
9080 | else if (shares > MAX_SHARES) |
9081 | shares = MAX_SHARES; | |
62fb1851 | 9082 | |
8ed36996 | 9083 | mutex_lock(&shares_mutex); |
9b5b7751 | 9084 | if (tg->shares == shares) |
5cb350ba | 9085 | goto done; |
29f59db3 | 9086 | |
8ed36996 | 9087 | spin_lock_irqsave(&task_group_lock, flags); |
bccbe08a PZ |
9088 | for_each_possible_cpu(i) |
9089 | unregister_fair_sched_group(tg, i); | |
f473aa5e | 9090 | list_del_rcu(&tg->siblings); |
8ed36996 | 9091 | spin_unlock_irqrestore(&task_group_lock, flags); |
6b2d7700 SV |
9092 | |
9093 | /* wait for any ongoing reference to this group to finish */ | |
9094 | synchronize_sched(); | |
9095 | ||
9096 | /* | |
9097 | * Now we are free to modify the group's share on each cpu | |
9098 | * w/o tripping rebalance_share or load_balance_fair. | |
9099 | */ | |
9b5b7751 | 9100 | tg->shares = shares; |
c09595f6 PZ |
9101 | for_each_possible_cpu(i) { |
9102 | /* | |
9103 | * force a rebalance | |
9104 | */ | |
9105 | cfs_rq_set_shares(tg->cfs_rq[i], 0); | |
cb4ad1ff | 9106 | set_se_shares(tg->se[i], shares); |
c09595f6 | 9107 | } |
29f59db3 | 9108 | |
6b2d7700 SV |
9109 | /* |
9110 | * Enable load balance activity on this group, by inserting it back on | |
9111 | * each cpu's rq->leaf_cfs_rq_list. | |
9112 | */ | |
8ed36996 | 9113 | spin_lock_irqsave(&task_group_lock, flags); |
bccbe08a PZ |
9114 | for_each_possible_cpu(i) |
9115 | register_fair_sched_group(tg, i); | |
f473aa5e | 9116 | list_add_rcu(&tg->siblings, &tg->parent->children); |
8ed36996 | 9117 | spin_unlock_irqrestore(&task_group_lock, flags); |
5cb350ba | 9118 | done: |
8ed36996 | 9119 | mutex_unlock(&shares_mutex); |
9b5b7751 | 9120 | return 0; |
29f59db3 SV |
9121 | } |
9122 | ||
5cb350ba DG |
9123 | unsigned long sched_group_shares(struct task_group *tg) |
9124 | { | |
9125 | return tg->shares; | |
9126 | } | |
052f1dc7 | 9127 | #endif |
5cb350ba | 9128 | |
052f1dc7 | 9129 | #ifdef CONFIG_RT_GROUP_SCHED |
6f505b16 | 9130 | /* |
9f0c1e56 | 9131 | * Ensure that the real time constraints are schedulable. |
6f505b16 | 9132 | */ |
9f0c1e56 PZ |
9133 | static DEFINE_MUTEX(rt_constraints_mutex); |
9134 | ||
9135 | static unsigned long to_ratio(u64 period, u64 runtime) | |
9136 | { | |
9137 | if (runtime == RUNTIME_INF) | |
9a7e0b18 | 9138 | return 1ULL << 20; |
9f0c1e56 | 9139 | |
9a7e0b18 | 9140 | return div64_u64(runtime << 20, period); |
9f0c1e56 PZ |
9141 | } |
9142 | ||
9a7e0b18 PZ |
9143 | /* Must be called with tasklist_lock held */ |
9144 | static inline int tg_has_rt_tasks(struct task_group *tg) | |
b40b2e8e | 9145 | { |
9a7e0b18 | 9146 | struct task_struct *g, *p; |
b40b2e8e | 9147 | |
9a7e0b18 PZ |
9148 | do_each_thread(g, p) { |
9149 | if (rt_task(p) && rt_rq_of_se(&p->rt)->tg == tg) | |
9150 | return 1; | |
9151 | } while_each_thread(g, p); | |
b40b2e8e | 9152 | |
9a7e0b18 PZ |
9153 | return 0; |
9154 | } | |
b40b2e8e | 9155 | |
9a7e0b18 PZ |
9156 | struct rt_schedulable_data { |
9157 | struct task_group *tg; | |
9158 | u64 rt_period; | |
9159 | u64 rt_runtime; | |
9160 | }; | |
b40b2e8e | 9161 | |
9a7e0b18 PZ |
9162 | static int tg_schedulable(struct task_group *tg, void *data) |
9163 | { | |
9164 | struct rt_schedulable_data *d = data; | |
9165 | struct task_group *child; | |
9166 | unsigned long total, sum = 0; | |
9167 | u64 period, runtime; | |
b40b2e8e | 9168 | |
9a7e0b18 PZ |
9169 | period = ktime_to_ns(tg->rt_bandwidth.rt_period); |
9170 | runtime = tg->rt_bandwidth.rt_runtime; | |
b40b2e8e | 9171 | |
9a7e0b18 PZ |
9172 | if (tg == d->tg) { |
9173 | period = d->rt_period; | |
9174 | runtime = d->rt_runtime; | |
b40b2e8e | 9175 | } |
b40b2e8e | 9176 | |
98a4826b PZ |
9177 | #ifdef CONFIG_USER_SCHED |
9178 | if (tg == &root_task_group) { | |
9179 | period = global_rt_period(); | |
9180 | runtime = global_rt_runtime(); | |
9181 | } | |
9182 | #endif | |
9183 | ||
4653f803 PZ |
9184 | /* |
9185 | * Cannot have more runtime than the period. | |
9186 | */ | |
9187 | if (runtime > period && runtime != RUNTIME_INF) | |
9188 | return -EINVAL; | |
6f505b16 | 9189 | |
4653f803 PZ |
9190 | /* |
9191 | * Ensure we don't starve existing RT tasks. | |
9192 | */ | |
9a7e0b18 PZ |
9193 | if (rt_bandwidth_enabled() && !runtime && tg_has_rt_tasks(tg)) |
9194 | return -EBUSY; | |
6f505b16 | 9195 | |
9a7e0b18 | 9196 | total = to_ratio(period, runtime); |
6f505b16 | 9197 | |
4653f803 PZ |
9198 | /* |
9199 | * Nobody can have more than the global setting allows. | |
9200 | */ | |
9201 | if (total > to_ratio(global_rt_period(), global_rt_runtime())) | |
9202 | return -EINVAL; | |
6f505b16 | 9203 | |
4653f803 PZ |
9204 | /* |
9205 | * The sum of our children's runtime should not exceed our own. | |
9206 | */ | |
9a7e0b18 PZ |
9207 | list_for_each_entry_rcu(child, &tg->children, siblings) { |
9208 | period = ktime_to_ns(child->rt_bandwidth.rt_period); | |
9209 | runtime = child->rt_bandwidth.rt_runtime; | |
6f505b16 | 9210 | |
9a7e0b18 PZ |
9211 | if (child == d->tg) { |
9212 | period = d->rt_period; | |
9213 | runtime = d->rt_runtime; | |
9214 | } | |
6f505b16 | 9215 | |
9a7e0b18 | 9216 | sum += to_ratio(period, runtime); |
9f0c1e56 | 9217 | } |
6f505b16 | 9218 | |
9a7e0b18 PZ |
9219 | if (sum > total) |
9220 | return -EINVAL; | |
9221 | ||
9222 | return 0; | |
6f505b16 PZ |
9223 | } |
9224 | ||
9a7e0b18 | 9225 | static int __rt_schedulable(struct task_group *tg, u64 period, u64 runtime) |
521f1a24 | 9226 | { |
9a7e0b18 PZ |
9227 | struct rt_schedulable_data data = { |
9228 | .tg = tg, | |
9229 | .rt_period = period, | |
9230 | .rt_runtime = runtime, | |
9231 | }; | |
9232 | ||
9233 | return walk_tg_tree(tg_schedulable, tg_nop, &data); | |
521f1a24 DG |
9234 | } |
9235 | ||
d0b27fa7 PZ |
9236 | static int tg_set_bandwidth(struct task_group *tg, |
9237 | u64 rt_period, u64 rt_runtime) | |
6f505b16 | 9238 | { |
ac086bc2 | 9239 | int i, err = 0; |
9f0c1e56 | 9240 | |
9f0c1e56 | 9241 | mutex_lock(&rt_constraints_mutex); |
521f1a24 | 9242 | read_lock(&tasklist_lock); |
9a7e0b18 PZ |
9243 | err = __rt_schedulable(tg, rt_period, rt_runtime); |
9244 | if (err) | |
9f0c1e56 | 9245 | goto unlock; |
ac086bc2 PZ |
9246 | |
9247 | spin_lock_irq(&tg->rt_bandwidth.rt_runtime_lock); | |
d0b27fa7 PZ |
9248 | tg->rt_bandwidth.rt_period = ns_to_ktime(rt_period); |
9249 | tg->rt_bandwidth.rt_runtime = rt_runtime; | |
ac086bc2 PZ |
9250 | |
9251 | for_each_possible_cpu(i) { | |
9252 | struct rt_rq *rt_rq = tg->rt_rq[i]; | |
9253 | ||
9254 | spin_lock(&rt_rq->rt_runtime_lock); | |
9255 | rt_rq->rt_runtime = rt_runtime; | |
9256 | spin_unlock(&rt_rq->rt_runtime_lock); | |
9257 | } | |
9258 | spin_unlock_irq(&tg->rt_bandwidth.rt_runtime_lock); | |
9f0c1e56 | 9259 | unlock: |
521f1a24 | 9260 | read_unlock(&tasklist_lock); |
9f0c1e56 PZ |
9261 | mutex_unlock(&rt_constraints_mutex); |
9262 | ||
9263 | return err; | |
6f505b16 PZ |
9264 | } |
9265 | ||
d0b27fa7 PZ |
9266 | int sched_group_set_rt_runtime(struct task_group *tg, long rt_runtime_us) |
9267 | { | |
9268 | u64 rt_runtime, rt_period; | |
9269 | ||
9270 | rt_period = ktime_to_ns(tg->rt_bandwidth.rt_period); | |
9271 | rt_runtime = (u64)rt_runtime_us * NSEC_PER_USEC; | |
9272 | if (rt_runtime_us < 0) | |
9273 | rt_runtime = RUNTIME_INF; | |
9274 | ||
9275 | return tg_set_bandwidth(tg, rt_period, rt_runtime); | |
9276 | } | |
9277 | ||
9f0c1e56 PZ |
9278 | long sched_group_rt_runtime(struct task_group *tg) |
9279 | { | |
9280 | u64 rt_runtime_us; | |
9281 | ||
d0b27fa7 | 9282 | if (tg->rt_bandwidth.rt_runtime == RUNTIME_INF) |
9f0c1e56 PZ |
9283 | return -1; |
9284 | ||
d0b27fa7 | 9285 | rt_runtime_us = tg->rt_bandwidth.rt_runtime; |
9f0c1e56 PZ |
9286 | do_div(rt_runtime_us, NSEC_PER_USEC); |
9287 | return rt_runtime_us; | |
9288 | } | |
d0b27fa7 PZ |
9289 | |
9290 | int sched_group_set_rt_period(struct task_group *tg, long rt_period_us) | |
9291 | { | |
9292 | u64 rt_runtime, rt_period; | |
9293 | ||
9294 | rt_period = (u64)rt_period_us * NSEC_PER_USEC; | |
9295 | rt_runtime = tg->rt_bandwidth.rt_runtime; | |
9296 | ||
619b0488 R |
9297 | if (rt_period == 0) |
9298 | return -EINVAL; | |
9299 | ||
d0b27fa7 PZ |
9300 | return tg_set_bandwidth(tg, rt_period, rt_runtime); |
9301 | } | |
9302 | ||
9303 | long sched_group_rt_period(struct task_group *tg) | |
9304 | { | |
9305 | u64 rt_period_us; | |
9306 | ||
9307 | rt_period_us = ktime_to_ns(tg->rt_bandwidth.rt_period); | |
9308 | do_div(rt_period_us, NSEC_PER_USEC); | |
9309 | return rt_period_us; | |
9310 | } | |
9311 | ||
9312 | static int sched_rt_global_constraints(void) | |
9313 | { | |
4653f803 | 9314 | u64 runtime, period; |
d0b27fa7 PZ |
9315 | int ret = 0; |
9316 | ||
ec5d4989 HS |
9317 | if (sysctl_sched_rt_period <= 0) |
9318 | return -EINVAL; | |
9319 | ||
4653f803 PZ |
9320 | runtime = global_rt_runtime(); |
9321 | period = global_rt_period(); | |
9322 | ||
9323 | /* | |
9324 | * Sanity check on the sysctl variables. | |
9325 | */ | |
9326 | if (runtime > period && runtime != RUNTIME_INF) | |
9327 | return -EINVAL; | |
10b612f4 | 9328 | |
d0b27fa7 | 9329 | mutex_lock(&rt_constraints_mutex); |
9a7e0b18 | 9330 | read_lock(&tasklist_lock); |
4653f803 | 9331 | ret = __rt_schedulable(NULL, 0, 0); |
9a7e0b18 | 9332 | read_unlock(&tasklist_lock); |
d0b27fa7 PZ |
9333 | mutex_unlock(&rt_constraints_mutex); |
9334 | ||
9335 | return ret; | |
9336 | } | |
6d6bc0ad | 9337 | #else /* !CONFIG_RT_GROUP_SCHED */ |
d0b27fa7 PZ |
9338 | static int sched_rt_global_constraints(void) |
9339 | { | |
ac086bc2 PZ |
9340 | unsigned long flags; |
9341 | int i; | |
9342 | ||
ec5d4989 HS |
9343 | if (sysctl_sched_rt_period <= 0) |
9344 | return -EINVAL; | |
9345 | ||
ac086bc2 PZ |
9346 | spin_lock_irqsave(&def_rt_bandwidth.rt_runtime_lock, flags); |
9347 | for_each_possible_cpu(i) { | |
9348 | struct rt_rq *rt_rq = &cpu_rq(i)->rt; | |
9349 | ||
9350 | spin_lock(&rt_rq->rt_runtime_lock); | |
9351 | rt_rq->rt_runtime = global_rt_runtime(); | |
9352 | spin_unlock(&rt_rq->rt_runtime_lock); | |
9353 | } | |
9354 | spin_unlock_irqrestore(&def_rt_bandwidth.rt_runtime_lock, flags); | |
9355 | ||
d0b27fa7 PZ |
9356 | return 0; |
9357 | } | |
6d6bc0ad | 9358 | #endif /* CONFIG_RT_GROUP_SCHED */ |
d0b27fa7 PZ |
9359 | |
9360 | int sched_rt_handler(struct ctl_table *table, int write, | |
9361 | struct file *filp, void __user *buffer, size_t *lenp, | |
9362 | loff_t *ppos) | |
9363 | { | |
9364 | int ret; | |
9365 | int old_period, old_runtime; | |
9366 | static DEFINE_MUTEX(mutex); | |
9367 | ||
9368 | mutex_lock(&mutex); | |
9369 | old_period = sysctl_sched_rt_period; | |
9370 | old_runtime = sysctl_sched_rt_runtime; | |
9371 | ||
9372 | ret = proc_dointvec(table, write, filp, buffer, lenp, ppos); | |
9373 | ||
9374 | if (!ret && write) { | |
9375 | ret = sched_rt_global_constraints(); | |
9376 | if (ret) { | |
9377 | sysctl_sched_rt_period = old_period; | |
9378 | sysctl_sched_rt_runtime = old_runtime; | |
9379 | } else { | |
9380 | def_rt_bandwidth.rt_runtime = global_rt_runtime(); | |
9381 | def_rt_bandwidth.rt_period = | |
9382 | ns_to_ktime(global_rt_period()); | |
9383 | } | |
9384 | } | |
9385 | mutex_unlock(&mutex); | |
9386 | ||
9387 | return ret; | |
9388 | } | |
68318b8e | 9389 | |
052f1dc7 | 9390 | #ifdef CONFIG_CGROUP_SCHED |
68318b8e SV |
9391 | |
9392 | /* return corresponding task_group object of a cgroup */ | |
2b01dfe3 | 9393 | static inline struct task_group *cgroup_tg(struct cgroup *cgrp) |
68318b8e | 9394 | { |
2b01dfe3 PM |
9395 | return container_of(cgroup_subsys_state(cgrp, cpu_cgroup_subsys_id), |
9396 | struct task_group, css); | |
68318b8e SV |
9397 | } |
9398 | ||
9399 | static struct cgroup_subsys_state * | |
2b01dfe3 | 9400 | cpu_cgroup_create(struct cgroup_subsys *ss, struct cgroup *cgrp) |
68318b8e | 9401 | { |
ec7dc8ac | 9402 | struct task_group *tg, *parent; |
68318b8e | 9403 | |
2b01dfe3 | 9404 | if (!cgrp->parent) { |
68318b8e | 9405 | /* This is early initialization for the top cgroup */ |
68318b8e SV |
9406 | return &init_task_group.css; |
9407 | } | |
9408 | ||
ec7dc8ac DG |
9409 | parent = cgroup_tg(cgrp->parent); |
9410 | tg = sched_create_group(parent); | |
68318b8e SV |
9411 | if (IS_ERR(tg)) |
9412 | return ERR_PTR(-ENOMEM); | |
9413 | ||
68318b8e SV |
9414 | return &tg->css; |
9415 | } | |
9416 | ||
41a2d6cf IM |
9417 | static void |
9418 | cpu_cgroup_destroy(struct cgroup_subsys *ss, struct cgroup *cgrp) | |
68318b8e | 9419 | { |
2b01dfe3 | 9420 | struct task_group *tg = cgroup_tg(cgrp); |
68318b8e SV |
9421 | |
9422 | sched_destroy_group(tg); | |
9423 | } | |
9424 | ||
41a2d6cf IM |
9425 | static int |
9426 | cpu_cgroup_can_attach(struct cgroup_subsys *ss, struct cgroup *cgrp, | |
9427 | struct task_struct *tsk) | |
68318b8e | 9428 | { |
b68aa230 PZ |
9429 | #ifdef CONFIG_RT_GROUP_SCHED |
9430 | /* Don't accept realtime tasks when there is no way for them to run */ | |
d0b27fa7 | 9431 | if (rt_task(tsk) && cgroup_tg(cgrp)->rt_bandwidth.rt_runtime == 0) |
b68aa230 PZ |
9432 | return -EINVAL; |
9433 | #else | |
68318b8e SV |
9434 | /* We don't support RT-tasks being in separate groups */ |
9435 | if (tsk->sched_class != &fair_sched_class) | |
9436 | return -EINVAL; | |
b68aa230 | 9437 | #endif |
68318b8e SV |
9438 | |
9439 | return 0; | |
9440 | } | |
9441 | ||
9442 | static void | |
2b01dfe3 | 9443 | cpu_cgroup_attach(struct cgroup_subsys *ss, struct cgroup *cgrp, |
68318b8e SV |
9444 | struct cgroup *old_cont, struct task_struct *tsk) |
9445 | { | |
9446 | sched_move_task(tsk); | |
9447 | } | |
9448 | ||
052f1dc7 | 9449 | #ifdef CONFIG_FAIR_GROUP_SCHED |
f4c753b7 | 9450 | static int cpu_shares_write_u64(struct cgroup *cgrp, struct cftype *cftype, |
2b01dfe3 | 9451 | u64 shareval) |
68318b8e | 9452 | { |
2b01dfe3 | 9453 | return sched_group_set_shares(cgroup_tg(cgrp), shareval); |
68318b8e SV |
9454 | } |
9455 | ||
f4c753b7 | 9456 | static u64 cpu_shares_read_u64(struct cgroup *cgrp, struct cftype *cft) |
68318b8e | 9457 | { |
2b01dfe3 | 9458 | struct task_group *tg = cgroup_tg(cgrp); |
68318b8e SV |
9459 | |
9460 | return (u64) tg->shares; | |
9461 | } | |
6d6bc0ad | 9462 | #endif /* CONFIG_FAIR_GROUP_SCHED */ |
68318b8e | 9463 | |
052f1dc7 | 9464 | #ifdef CONFIG_RT_GROUP_SCHED |
0c70814c | 9465 | static int cpu_rt_runtime_write(struct cgroup *cgrp, struct cftype *cft, |
06ecb27c | 9466 | s64 val) |
6f505b16 | 9467 | { |
06ecb27c | 9468 | return sched_group_set_rt_runtime(cgroup_tg(cgrp), val); |
6f505b16 PZ |
9469 | } |
9470 | ||
06ecb27c | 9471 | static s64 cpu_rt_runtime_read(struct cgroup *cgrp, struct cftype *cft) |
6f505b16 | 9472 | { |
06ecb27c | 9473 | return sched_group_rt_runtime(cgroup_tg(cgrp)); |
6f505b16 | 9474 | } |
d0b27fa7 PZ |
9475 | |
9476 | static int cpu_rt_period_write_uint(struct cgroup *cgrp, struct cftype *cftype, | |
9477 | u64 rt_period_us) | |
9478 | { | |
9479 | return sched_group_set_rt_period(cgroup_tg(cgrp), rt_period_us); | |
9480 | } | |
9481 | ||
9482 | static u64 cpu_rt_period_read_uint(struct cgroup *cgrp, struct cftype *cft) | |
9483 | { | |
9484 | return sched_group_rt_period(cgroup_tg(cgrp)); | |
9485 | } | |
6d6bc0ad | 9486 | #endif /* CONFIG_RT_GROUP_SCHED */ |
6f505b16 | 9487 | |
fe5c7cc2 | 9488 | static struct cftype cpu_files[] = { |
052f1dc7 | 9489 | #ifdef CONFIG_FAIR_GROUP_SCHED |
fe5c7cc2 PM |
9490 | { |
9491 | .name = "shares", | |
f4c753b7 PM |
9492 | .read_u64 = cpu_shares_read_u64, |
9493 | .write_u64 = cpu_shares_write_u64, | |
fe5c7cc2 | 9494 | }, |
052f1dc7 PZ |
9495 | #endif |
9496 | #ifdef CONFIG_RT_GROUP_SCHED | |
6f505b16 | 9497 | { |
9f0c1e56 | 9498 | .name = "rt_runtime_us", |
06ecb27c PM |
9499 | .read_s64 = cpu_rt_runtime_read, |
9500 | .write_s64 = cpu_rt_runtime_write, | |
6f505b16 | 9501 | }, |
d0b27fa7 PZ |
9502 | { |
9503 | .name = "rt_period_us", | |
f4c753b7 PM |
9504 | .read_u64 = cpu_rt_period_read_uint, |
9505 | .write_u64 = cpu_rt_period_write_uint, | |
d0b27fa7 | 9506 | }, |
052f1dc7 | 9507 | #endif |
68318b8e SV |
9508 | }; |
9509 | ||
9510 | static int cpu_cgroup_populate(struct cgroup_subsys *ss, struct cgroup *cont) | |
9511 | { | |
fe5c7cc2 | 9512 | return cgroup_add_files(cont, ss, cpu_files, ARRAY_SIZE(cpu_files)); |
68318b8e SV |
9513 | } |
9514 | ||
9515 | struct cgroup_subsys cpu_cgroup_subsys = { | |
38605cae IM |
9516 | .name = "cpu", |
9517 | .create = cpu_cgroup_create, | |
9518 | .destroy = cpu_cgroup_destroy, | |
9519 | .can_attach = cpu_cgroup_can_attach, | |
9520 | .attach = cpu_cgroup_attach, | |
9521 | .populate = cpu_cgroup_populate, | |
9522 | .subsys_id = cpu_cgroup_subsys_id, | |
68318b8e SV |
9523 | .early_init = 1, |
9524 | }; | |
9525 | ||
052f1dc7 | 9526 | #endif /* CONFIG_CGROUP_SCHED */ |
d842de87 SV |
9527 | |
9528 | #ifdef CONFIG_CGROUP_CPUACCT | |
9529 | ||
9530 | /* | |
9531 | * CPU accounting code for task groups. | |
9532 | * | |
9533 | * Based on the work by Paul Menage (menage@google.com) and Balbir Singh | |
9534 | * (balbir@in.ibm.com). | |
9535 | */ | |
9536 | ||
934352f2 | 9537 | /* track cpu usage of a group of tasks and its child groups */ |
d842de87 SV |
9538 | struct cpuacct { |
9539 | struct cgroup_subsys_state css; | |
9540 | /* cpuusage holds pointer to a u64-type object on every cpu */ | |
9541 | u64 *cpuusage; | |
934352f2 | 9542 | struct cpuacct *parent; |
d842de87 SV |
9543 | }; |
9544 | ||
9545 | struct cgroup_subsys cpuacct_subsys; | |
9546 | ||
9547 | /* return cpu accounting group corresponding to this container */ | |
32cd756a | 9548 | static inline struct cpuacct *cgroup_ca(struct cgroup *cgrp) |
d842de87 | 9549 | { |
32cd756a | 9550 | return container_of(cgroup_subsys_state(cgrp, cpuacct_subsys_id), |
d842de87 SV |
9551 | struct cpuacct, css); |
9552 | } | |
9553 | ||
9554 | /* return cpu accounting group to which this task belongs */ | |
9555 | static inline struct cpuacct *task_ca(struct task_struct *tsk) | |
9556 | { | |
9557 | return container_of(task_subsys_state(tsk, cpuacct_subsys_id), | |
9558 | struct cpuacct, css); | |
9559 | } | |
9560 | ||
9561 | /* create a new cpu accounting group */ | |
9562 | static struct cgroup_subsys_state *cpuacct_create( | |
32cd756a | 9563 | struct cgroup_subsys *ss, struct cgroup *cgrp) |
d842de87 SV |
9564 | { |
9565 | struct cpuacct *ca = kzalloc(sizeof(*ca), GFP_KERNEL); | |
9566 | ||
9567 | if (!ca) | |
9568 | return ERR_PTR(-ENOMEM); | |
9569 | ||
9570 | ca->cpuusage = alloc_percpu(u64); | |
9571 | if (!ca->cpuusage) { | |
9572 | kfree(ca); | |
9573 | return ERR_PTR(-ENOMEM); | |
9574 | } | |
9575 | ||
934352f2 BR |
9576 | if (cgrp->parent) |
9577 | ca->parent = cgroup_ca(cgrp->parent); | |
9578 | ||
d842de87 SV |
9579 | return &ca->css; |
9580 | } | |
9581 | ||
9582 | /* destroy an existing cpu accounting group */ | |
41a2d6cf | 9583 | static void |
32cd756a | 9584 | cpuacct_destroy(struct cgroup_subsys *ss, struct cgroup *cgrp) |
d842de87 | 9585 | { |
32cd756a | 9586 | struct cpuacct *ca = cgroup_ca(cgrp); |
d842de87 SV |
9587 | |
9588 | free_percpu(ca->cpuusage); | |
9589 | kfree(ca); | |
9590 | } | |
9591 | ||
720f5498 KC |
9592 | static u64 cpuacct_cpuusage_read(struct cpuacct *ca, int cpu) |
9593 | { | |
9594 | u64 *cpuusage = percpu_ptr(ca->cpuusage, cpu); | |
9595 | u64 data; | |
9596 | ||
9597 | #ifndef CONFIG_64BIT | |
9598 | /* | |
9599 | * Take rq->lock to make 64-bit read safe on 32-bit platforms. | |
9600 | */ | |
9601 | spin_lock_irq(&cpu_rq(cpu)->lock); | |
9602 | data = *cpuusage; | |
9603 | spin_unlock_irq(&cpu_rq(cpu)->lock); | |
9604 | #else | |
9605 | data = *cpuusage; | |
9606 | #endif | |
9607 | ||
9608 | return data; | |
9609 | } | |
9610 | ||
9611 | static void cpuacct_cpuusage_write(struct cpuacct *ca, int cpu, u64 val) | |
9612 | { | |
9613 | u64 *cpuusage = percpu_ptr(ca->cpuusage, cpu); | |
9614 | ||
9615 | #ifndef CONFIG_64BIT | |
9616 | /* | |
9617 | * Take rq->lock to make 64-bit write safe on 32-bit platforms. | |
9618 | */ | |
9619 | spin_lock_irq(&cpu_rq(cpu)->lock); | |
9620 | *cpuusage = val; | |
9621 | spin_unlock_irq(&cpu_rq(cpu)->lock); | |
9622 | #else | |
9623 | *cpuusage = val; | |
9624 | #endif | |
9625 | } | |
9626 | ||
d842de87 | 9627 | /* return total cpu usage (in nanoseconds) of a group */ |
32cd756a | 9628 | static u64 cpuusage_read(struct cgroup *cgrp, struct cftype *cft) |
d842de87 | 9629 | { |
32cd756a | 9630 | struct cpuacct *ca = cgroup_ca(cgrp); |
d842de87 SV |
9631 | u64 totalcpuusage = 0; |
9632 | int i; | |
9633 | ||
720f5498 KC |
9634 | for_each_present_cpu(i) |
9635 | totalcpuusage += cpuacct_cpuusage_read(ca, i); | |
d842de87 SV |
9636 | |
9637 | return totalcpuusage; | |
9638 | } | |
9639 | ||
0297b803 DG |
9640 | static int cpuusage_write(struct cgroup *cgrp, struct cftype *cftype, |
9641 | u64 reset) | |
9642 | { | |
9643 | struct cpuacct *ca = cgroup_ca(cgrp); | |
9644 | int err = 0; | |
9645 | int i; | |
9646 | ||
9647 | if (reset) { | |
9648 | err = -EINVAL; | |
9649 | goto out; | |
9650 | } | |
9651 | ||
720f5498 KC |
9652 | for_each_present_cpu(i) |
9653 | cpuacct_cpuusage_write(ca, i, 0); | |
0297b803 | 9654 | |
0297b803 DG |
9655 | out: |
9656 | return err; | |
9657 | } | |
9658 | ||
e9515c3c KC |
9659 | static int cpuacct_percpu_seq_read(struct cgroup *cgroup, struct cftype *cft, |
9660 | struct seq_file *m) | |
9661 | { | |
9662 | struct cpuacct *ca = cgroup_ca(cgroup); | |
9663 | u64 percpu; | |
9664 | int i; | |
9665 | ||
9666 | for_each_present_cpu(i) { | |
9667 | percpu = cpuacct_cpuusage_read(ca, i); | |
9668 | seq_printf(m, "%llu ", (unsigned long long) percpu); | |
9669 | } | |
9670 | seq_printf(m, "\n"); | |
9671 | return 0; | |
9672 | } | |
9673 | ||
d842de87 SV |
9674 | static struct cftype files[] = { |
9675 | { | |
9676 | .name = "usage", | |
f4c753b7 PM |
9677 | .read_u64 = cpuusage_read, |
9678 | .write_u64 = cpuusage_write, | |
d842de87 | 9679 | }, |
e9515c3c KC |
9680 | { |
9681 | .name = "usage_percpu", | |
9682 | .read_seq_string = cpuacct_percpu_seq_read, | |
9683 | }, | |
9684 | ||
d842de87 SV |
9685 | }; |
9686 | ||
32cd756a | 9687 | static int cpuacct_populate(struct cgroup_subsys *ss, struct cgroup *cgrp) |
d842de87 | 9688 | { |
32cd756a | 9689 | return cgroup_add_files(cgrp, ss, files, ARRAY_SIZE(files)); |
d842de87 SV |
9690 | } |
9691 | ||
9692 | /* | |
9693 | * charge this task's execution time to its accounting group. | |
9694 | * | |
9695 | * called with rq->lock held. | |
9696 | */ | |
9697 | static void cpuacct_charge(struct task_struct *tsk, u64 cputime) | |
9698 | { | |
9699 | struct cpuacct *ca; | |
934352f2 | 9700 | int cpu; |
d842de87 SV |
9701 | |
9702 | if (!cpuacct_subsys.active) | |
9703 | return; | |
9704 | ||
934352f2 | 9705 | cpu = task_cpu(tsk); |
a18b83b7 BR |
9706 | |
9707 | rcu_read_lock(); | |
9708 | ||
d842de87 | 9709 | ca = task_ca(tsk); |
d842de87 | 9710 | |
934352f2 BR |
9711 | for (; ca; ca = ca->parent) { |
9712 | u64 *cpuusage = percpu_ptr(ca->cpuusage, cpu); | |
d842de87 SV |
9713 | *cpuusage += cputime; |
9714 | } | |
a18b83b7 BR |
9715 | |
9716 | rcu_read_unlock(); | |
d842de87 SV |
9717 | } |
9718 | ||
9719 | struct cgroup_subsys cpuacct_subsys = { | |
9720 | .name = "cpuacct", | |
9721 | .create = cpuacct_create, | |
9722 | .destroy = cpuacct_destroy, | |
9723 | .populate = cpuacct_populate, | |
9724 | .subsys_id = cpuacct_subsys_id, | |
9725 | }; | |
9726 | #endif /* CONFIG_CGROUP_CPUACCT */ |