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1da177e4 LT |
1 | /* |
2 | * kernel/sched.c | |
3 | * | |
4 | * Kernel scheduler and related syscalls | |
5 | * | |
6 | * Copyright (C) 1991-2002 Linus Torvalds | |
7 | * | |
8 | * 1996-12-23 Modified by Dave Grothe to fix bugs in semaphores and | |
9 | * make semaphores SMP safe | |
10 | * 1998-11-19 Implemented schedule_timeout() and related stuff | |
11 | * by Andrea Arcangeli | |
12 | * 2002-01-04 New ultra-scalable O(1) scheduler by Ingo Molnar: | |
13 | * hybrid priority-list and round-robin design with | |
14 | * an array-switch method of distributing timeslices | |
15 | * and per-CPU runqueues. Cleanups and useful suggestions | |
16 | * by Davide Libenzi, preemptible kernel bits by Robert Love. | |
17 | * 2003-09-03 Interactivity tuning by Con Kolivas. | |
18 | * 2004-04-02 Scheduler domains code by Nick Piggin | |
c31f2e8a IM |
19 | * 2007-04-15 Work begun on replacing all interactivity tuning with a |
20 | * fair scheduling design by Con Kolivas. | |
21 | * 2007-05-05 Load balancing (smp-nice) and other improvements | |
22 | * by Peter Williams | |
23 | * 2007-05-06 Interactivity improvements to CFS by Mike Galbraith | |
24 | * 2007-07-01 Group scheduling enhancements by Srivatsa Vaddagiri | |
b9131769 IM |
25 | * 2007-11-29 RT balancing improvements by Steven Rostedt, Gregory Haskins, |
26 | * Thomas Gleixner, Mike Kravetz | |
1da177e4 LT |
27 | */ |
28 | ||
29 | #include <linux/mm.h> | |
30 | #include <linux/module.h> | |
31 | #include <linux/nmi.h> | |
32 | #include <linux/init.h> | |
dff06c15 | 33 | #include <linux/uaccess.h> |
1da177e4 LT |
34 | #include <linux/highmem.h> |
35 | #include <linux/smp_lock.h> | |
36 | #include <asm/mmu_context.h> | |
37 | #include <linux/interrupt.h> | |
c59ede7b | 38 | #include <linux/capability.h> |
1da177e4 LT |
39 | #include <linux/completion.h> |
40 | #include <linux/kernel_stat.h> | |
9a11b49a | 41 | #include <linux/debug_locks.h> |
cdd6c482 | 42 | #include <linux/perf_event.h> |
1da177e4 LT |
43 | #include <linux/security.h> |
44 | #include <linux/notifier.h> | |
45 | #include <linux/profile.h> | |
7dfb7103 | 46 | #include <linux/freezer.h> |
198e2f18 | 47 | #include <linux/vmalloc.h> |
1da177e4 LT |
48 | #include <linux/blkdev.h> |
49 | #include <linux/delay.h> | |
b488893a | 50 | #include <linux/pid_namespace.h> |
1da177e4 LT |
51 | #include <linux/smp.h> |
52 | #include <linux/threads.h> | |
53 | #include <linux/timer.h> | |
54 | #include <linux/rcupdate.h> | |
55 | #include <linux/cpu.h> | |
56 | #include <linux/cpuset.h> | |
57 | #include <linux/percpu.h> | |
58 | #include <linux/kthread.h> | |
b5aadf7f | 59 | #include <linux/proc_fs.h> |
1da177e4 | 60 | #include <linux/seq_file.h> |
e692ab53 | 61 | #include <linux/sysctl.h> |
1da177e4 LT |
62 | #include <linux/syscalls.h> |
63 | #include <linux/times.h> | |
8f0ab514 | 64 | #include <linux/tsacct_kern.h> |
c6fd91f0 | 65 | #include <linux/kprobes.h> |
0ff92245 | 66 | #include <linux/delayacct.h> |
dff06c15 | 67 | #include <linux/unistd.h> |
f5ff8422 | 68 | #include <linux/pagemap.h> |
8f4d37ec | 69 | #include <linux/hrtimer.h> |
30914a58 | 70 | #include <linux/tick.h> |
f00b45c1 PZ |
71 | #include <linux/debugfs.h> |
72 | #include <linux/ctype.h> | |
6cd8a4bb | 73 | #include <linux/ftrace.h> |
5a0e3ad6 | 74 | #include <linux/slab.h> |
1da177e4 | 75 | |
5517d86b | 76 | #include <asm/tlb.h> |
838225b4 | 77 | #include <asm/irq_regs.h> |
1da177e4 | 78 | |
6e0534f2 GH |
79 | #include "sched_cpupri.h" |
80 | ||
a8d154b0 | 81 | #define CREATE_TRACE_POINTS |
ad8d75ff | 82 | #include <trace/events/sched.h> |
a8d154b0 | 83 | |
1da177e4 LT |
84 | /* |
85 | * Convert user-nice values [ -20 ... 0 ... 19 ] | |
86 | * to static priority [ MAX_RT_PRIO..MAX_PRIO-1 ], | |
87 | * and back. | |
88 | */ | |
89 | #define NICE_TO_PRIO(nice) (MAX_RT_PRIO + (nice) + 20) | |
90 | #define PRIO_TO_NICE(prio) ((prio) - MAX_RT_PRIO - 20) | |
91 | #define TASK_NICE(p) PRIO_TO_NICE((p)->static_prio) | |
92 | ||
93 | /* | |
94 | * 'User priority' is the nice value converted to something we | |
95 | * can work with better when scaling various scheduler parameters, | |
96 | * it's a [ 0 ... 39 ] range. | |
97 | */ | |
98 | #define USER_PRIO(p) ((p)-MAX_RT_PRIO) | |
99 | #define TASK_USER_PRIO(p) USER_PRIO((p)->static_prio) | |
100 | #define MAX_USER_PRIO (USER_PRIO(MAX_PRIO)) | |
101 | ||
102 | /* | |
d7876a08 | 103 | * Helpers for converting nanosecond timing to jiffy resolution |
1da177e4 | 104 | */ |
d6322faf | 105 | #define NS_TO_JIFFIES(TIME) ((unsigned long)(TIME) / (NSEC_PER_SEC / HZ)) |
1da177e4 | 106 | |
6aa645ea IM |
107 | #define NICE_0_LOAD SCHED_LOAD_SCALE |
108 | #define NICE_0_SHIFT SCHED_LOAD_SHIFT | |
109 | ||
1da177e4 LT |
110 | /* |
111 | * These are the 'tuning knobs' of the scheduler: | |
112 | * | |
a4ec24b4 | 113 | * default timeslice is 100 msecs (used only for SCHED_RR tasks). |
1da177e4 LT |
114 | * Timeslices get refilled after they expire. |
115 | */ | |
1da177e4 | 116 | #define DEF_TIMESLICE (100 * HZ / 1000) |
2dd73a4f | 117 | |
d0b27fa7 PZ |
118 | /* |
119 | * single value that denotes runtime == period, ie unlimited time. | |
120 | */ | |
121 | #define RUNTIME_INF ((u64)~0ULL) | |
122 | ||
e05606d3 IM |
123 | static inline int rt_policy(int policy) |
124 | { | |
3f33a7ce | 125 | if (unlikely(policy == SCHED_FIFO || policy == SCHED_RR)) |
e05606d3 IM |
126 | return 1; |
127 | return 0; | |
128 | } | |
129 | ||
130 | static inline int task_has_rt_policy(struct task_struct *p) | |
131 | { | |
132 | return rt_policy(p->policy); | |
133 | } | |
134 | ||
1da177e4 | 135 | /* |
6aa645ea | 136 | * This is the priority-queue data structure of the RT scheduling class: |
1da177e4 | 137 | */ |
6aa645ea IM |
138 | struct rt_prio_array { |
139 | DECLARE_BITMAP(bitmap, MAX_RT_PRIO+1); /* include 1 bit for delimiter */ | |
140 | struct list_head queue[MAX_RT_PRIO]; | |
141 | }; | |
142 | ||
d0b27fa7 | 143 | struct rt_bandwidth { |
ea736ed5 | 144 | /* nests inside the rq lock: */ |
0986b11b | 145 | raw_spinlock_t rt_runtime_lock; |
ea736ed5 IM |
146 | ktime_t rt_period; |
147 | u64 rt_runtime; | |
148 | struct hrtimer rt_period_timer; | |
d0b27fa7 PZ |
149 | }; |
150 | ||
151 | static struct rt_bandwidth def_rt_bandwidth; | |
152 | ||
153 | static int do_sched_rt_period_timer(struct rt_bandwidth *rt_b, int overrun); | |
154 | ||
155 | static enum hrtimer_restart sched_rt_period_timer(struct hrtimer *timer) | |
156 | { | |
157 | struct rt_bandwidth *rt_b = | |
158 | container_of(timer, struct rt_bandwidth, rt_period_timer); | |
159 | ktime_t now; | |
160 | int overrun; | |
161 | int idle = 0; | |
162 | ||
163 | for (;;) { | |
164 | now = hrtimer_cb_get_time(timer); | |
165 | overrun = hrtimer_forward(timer, now, rt_b->rt_period); | |
166 | ||
167 | if (!overrun) | |
168 | break; | |
169 | ||
170 | idle = do_sched_rt_period_timer(rt_b, overrun); | |
171 | } | |
172 | ||
173 | return idle ? HRTIMER_NORESTART : HRTIMER_RESTART; | |
174 | } | |
175 | ||
176 | static | |
177 | void init_rt_bandwidth(struct rt_bandwidth *rt_b, u64 period, u64 runtime) | |
178 | { | |
179 | rt_b->rt_period = ns_to_ktime(period); | |
180 | rt_b->rt_runtime = runtime; | |
181 | ||
0986b11b | 182 | raw_spin_lock_init(&rt_b->rt_runtime_lock); |
ac086bc2 | 183 | |
d0b27fa7 PZ |
184 | hrtimer_init(&rt_b->rt_period_timer, |
185 | CLOCK_MONOTONIC, HRTIMER_MODE_REL); | |
186 | rt_b->rt_period_timer.function = sched_rt_period_timer; | |
d0b27fa7 PZ |
187 | } |
188 | ||
c8bfff6d KH |
189 | static inline int rt_bandwidth_enabled(void) |
190 | { | |
191 | return sysctl_sched_rt_runtime >= 0; | |
d0b27fa7 PZ |
192 | } |
193 | ||
194 | static void start_rt_bandwidth(struct rt_bandwidth *rt_b) | |
195 | { | |
196 | ktime_t now; | |
197 | ||
cac64d00 | 198 | if (!rt_bandwidth_enabled() || rt_b->rt_runtime == RUNTIME_INF) |
d0b27fa7 PZ |
199 | return; |
200 | ||
201 | if (hrtimer_active(&rt_b->rt_period_timer)) | |
202 | return; | |
203 | ||
0986b11b | 204 | raw_spin_lock(&rt_b->rt_runtime_lock); |
d0b27fa7 | 205 | for (;;) { |
7f1e2ca9 PZ |
206 | unsigned long delta; |
207 | ktime_t soft, hard; | |
208 | ||
d0b27fa7 PZ |
209 | if (hrtimer_active(&rt_b->rt_period_timer)) |
210 | break; | |
211 | ||
212 | now = hrtimer_cb_get_time(&rt_b->rt_period_timer); | |
213 | hrtimer_forward(&rt_b->rt_period_timer, now, rt_b->rt_period); | |
7f1e2ca9 PZ |
214 | |
215 | soft = hrtimer_get_softexpires(&rt_b->rt_period_timer); | |
216 | hard = hrtimer_get_expires(&rt_b->rt_period_timer); | |
217 | delta = ktime_to_ns(ktime_sub(hard, soft)); | |
218 | __hrtimer_start_range_ns(&rt_b->rt_period_timer, soft, delta, | |
5c333864 | 219 | HRTIMER_MODE_ABS_PINNED, 0); |
d0b27fa7 | 220 | } |
0986b11b | 221 | raw_spin_unlock(&rt_b->rt_runtime_lock); |
d0b27fa7 PZ |
222 | } |
223 | ||
224 | #ifdef CONFIG_RT_GROUP_SCHED | |
225 | static void destroy_rt_bandwidth(struct rt_bandwidth *rt_b) | |
226 | { | |
227 | hrtimer_cancel(&rt_b->rt_period_timer); | |
228 | } | |
229 | #endif | |
230 | ||
712555ee HC |
231 | /* |
232 | * sched_domains_mutex serializes calls to arch_init_sched_domains, | |
233 | * detach_destroy_domains and partition_sched_domains. | |
234 | */ | |
235 | static DEFINE_MUTEX(sched_domains_mutex); | |
236 | ||
7c941438 | 237 | #ifdef CONFIG_CGROUP_SCHED |
29f59db3 | 238 | |
68318b8e SV |
239 | #include <linux/cgroup.h> |
240 | ||
29f59db3 SV |
241 | struct cfs_rq; |
242 | ||
6f505b16 PZ |
243 | static LIST_HEAD(task_groups); |
244 | ||
29f59db3 | 245 | /* task group related information */ |
4cf86d77 | 246 | struct task_group { |
68318b8e | 247 | struct cgroup_subsys_state css; |
6c415b92 | 248 | |
052f1dc7 | 249 | #ifdef CONFIG_FAIR_GROUP_SCHED |
29f59db3 SV |
250 | /* schedulable entities of this group on each cpu */ |
251 | struct sched_entity **se; | |
252 | /* runqueue "owned" by this group on each cpu */ | |
253 | struct cfs_rq **cfs_rq; | |
254 | unsigned long shares; | |
052f1dc7 PZ |
255 | #endif |
256 | ||
257 | #ifdef CONFIG_RT_GROUP_SCHED | |
258 | struct sched_rt_entity **rt_se; | |
259 | struct rt_rq **rt_rq; | |
260 | ||
d0b27fa7 | 261 | struct rt_bandwidth rt_bandwidth; |
052f1dc7 | 262 | #endif |
6b2d7700 | 263 | |
ae8393e5 | 264 | struct rcu_head rcu; |
6f505b16 | 265 | struct list_head list; |
f473aa5e PZ |
266 | |
267 | struct task_group *parent; | |
268 | struct list_head siblings; | |
269 | struct list_head children; | |
29f59db3 SV |
270 | }; |
271 | ||
eff766a6 | 272 | #define root_task_group init_task_group |
6f505b16 | 273 | |
8ed36996 | 274 | /* task_group_lock serializes add/remove of task groups and also changes to |
ec2c507f SV |
275 | * a task group's cpu shares. |
276 | */ | |
8ed36996 | 277 | static DEFINE_SPINLOCK(task_group_lock); |
ec2c507f | 278 | |
e9036b36 CG |
279 | #ifdef CONFIG_FAIR_GROUP_SCHED |
280 | ||
57310a98 PZ |
281 | #ifdef CONFIG_SMP |
282 | static int root_task_group_empty(void) | |
283 | { | |
284 | return list_empty(&root_task_group.children); | |
285 | } | |
286 | #endif | |
287 | ||
052f1dc7 | 288 | # define INIT_TASK_GROUP_LOAD NICE_0_LOAD |
052f1dc7 | 289 | |
cb4ad1ff | 290 | /* |
2e084786 LJ |
291 | * A weight of 0 or 1 can cause arithmetics problems. |
292 | * A weight of a cfs_rq is the sum of weights of which entities | |
293 | * are queued on this cfs_rq, so a weight of a entity should not be | |
294 | * too large, so as the shares value of a task group. | |
cb4ad1ff MX |
295 | * (The default weight is 1024 - so there's no practical |
296 | * limitation from this.) | |
297 | */ | |
18d95a28 | 298 | #define MIN_SHARES 2 |
2e084786 | 299 | #define MAX_SHARES (1UL << 18) |
18d95a28 | 300 | |
052f1dc7 PZ |
301 | static int init_task_group_load = INIT_TASK_GROUP_LOAD; |
302 | #endif | |
303 | ||
29f59db3 | 304 | /* Default task group. |
3a252015 | 305 | * Every task in system belong to this group at bootup. |
29f59db3 | 306 | */ |
434d53b0 | 307 | struct task_group init_task_group; |
29f59db3 SV |
308 | |
309 | /* return group to which a task belongs */ | |
4cf86d77 | 310 | static inline struct task_group *task_group(struct task_struct *p) |
29f59db3 | 311 | { |
4cf86d77 | 312 | struct task_group *tg; |
9b5b7751 | 313 | |
7c941438 | 314 | #ifdef CONFIG_CGROUP_SCHED |
68318b8e SV |
315 | tg = container_of(task_subsys_state(p, cpu_cgroup_subsys_id), |
316 | struct task_group, css); | |
24e377a8 | 317 | #else |
41a2d6cf | 318 | tg = &init_task_group; |
24e377a8 | 319 | #endif |
9b5b7751 | 320 | return tg; |
29f59db3 SV |
321 | } |
322 | ||
323 | /* Change a task's cfs_rq and parent entity if it moves across CPUs/groups */ | |
6f505b16 | 324 | static inline void set_task_rq(struct task_struct *p, unsigned int cpu) |
29f59db3 | 325 | { |
052f1dc7 | 326 | #ifdef CONFIG_FAIR_GROUP_SCHED |
ce96b5ac DA |
327 | p->se.cfs_rq = task_group(p)->cfs_rq[cpu]; |
328 | p->se.parent = task_group(p)->se[cpu]; | |
052f1dc7 | 329 | #endif |
6f505b16 | 330 | |
052f1dc7 | 331 | #ifdef CONFIG_RT_GROUP_SCHED |
6f505b16 PZ |
332 | p->rt.rt_rq = task_group(p)->rt_rq[cpu]; |
333 | p->rt.parent = task_group(p)->rt_se[cpu]; | |
052f1dc7 | 334 | #endif |
29f59db3 SV |
335 | } |
336 | ||
337 | #else | |
338 | ||
6f505b16 | 339 | static inline void set_task_rq(struct task_struct *p, unsigned int cpu) { } |
83378269 PZ |
340 | static inline struct task_group *task_group(struct task_struct *p) |
341 | { | |
342 | return NULL; | |
343 | } | |
29f59db3 | 344 | |
7c941438 | 345 | #endif /* CONFIG_CGROUP_SCHED */ |
29f59db3 | 346 | |
6aa645ea IM |
347 | /* CFS-related fields in a runqueue */ |
348 | struct cfs_rq { | |
349 | struct load_weight load; | |
350 | unsigned long nr_running; | |
351 | ||
6aa645ea | 352 | u64 exec_clock; |
e9acbff6 | 353 | u64 min_vruntime; |
6aa645ea IM |
354 | |
355 | struct rb_root tasks_timeline; | |
356 | struct rb_node *rb_leftmost; | |
4a55bd5e PZ |
357 | |
358 | struct list_head tasks; | |
359 | struct list_head *balance_iterator; | |
360 | ||
361 | /* | |
362 | * 'curr' points to currently running entity on this cfs_rq. | |
6aa645ea IM |
363 | * It is set to NULL otherwise (i.e when none are currently running). |
364 | */ | |
4793241b | 365 | struct sched_entity *curr, *next, *last; |
ddc97297 | 366 | |
5ac5c4d6 | 367 | unsigned int nr_spread_over; |
ddc97297 | 368 | |
62160e3f | 369 | #ifdef CONFIG_FAIR_GROUP_SCHED |
6aa645ea IM |
370 | struct rq *rq; /* cpu runqueue to which this cfs_rq is attached */ |
371 | ||
41a2d6cf IM |
372 | /* |
373 | * leaf cfs_rqs are those that hold tasks (lowest schedulable entity in | |
6aa645ea IM |
374 | * a hierarchy). Non-leaf lrqs hold other higher schedulable entities |
375 | * (like users, containers etc.) | |
376 | * | |
377 | * leaf_cfs_rq_list ties together list of leaf cfs_rq's in a cpu. This | |
378 | * list is used during load balance. | |
379 | */ | |
41a2d6cf IM |
380 | struct list_head leaf_cfs_rq_list; |
381 | struct task_group *tg; /* group that "owns" this runqueue */ | |
c09595f6 PZ |
382 | |
383 | #ifdef CONFIG_SMP | |
c09595f6 | 384 | /* |
c8cba857 | 385 | * the part of load.weight contributed by tasks |
c09595f6 | 386 | */ |
c8cba857 | 387 | unsigned long task_weight; |
c09595f6 | 388 | |
c8cba857 PZ |
389 | /* |
390 | * h_load = weight * f(tg) | |
391 | * | |
392 | * Where f(tg) is the recursive weight fraction assigned to | |
393 | * this group. | |
394 | */ | |
395 | unsigned long h_load; | |
c09595f6 | 396 | |
c8cba857 PZ |
397 | /* |
398 | * this cpu's part of tg->shares | |
399 | */ | |
400 | unsigned long shares; | |
f1d239f7 PZ |
401 | |
402 | /* | |
403 | * load.weight at the time we set shares | |
404 | */ | |
405 | unsigned long rq_weight; | |
c09595f6 | 406 | #endif |
6aa645ea IM |
407 | #endif |
408 | }; | |
1da177e4 | 409 | |
6aa645ea IM |
410 | /* Real-Time classes' related field in a runqueue: */ |
411 | struct rt_rq { | |
412 | struct rt_prio_array active; | |
63489e45 | 413 | unsigned long rt_nr_running; |
052f1dc7 | 414 | #if defined CONFIG_SMP || defined CONFIG_RT_GROUP_SCHED |
e864c499 GH |
415 | struct { |
416 | int curr; /* highest queued rt task prio */ | |
398a153b | 417 | #ifdef CONFIG_SMP |
e864c499 | 418 | int next; /* next highest */ |
398a153b | 419 | #endif |
e864c499 | 420 | } highest_prio; |
6f505b16 | 421 | #endif |
fa85ae24 | 422 | #ifdef CONFIG_SMP |
73fe6aae | 423 | unsigned long rt_nr_migratory; |
a1ba4d8b | 424 | unsigned long rt_nr_total; |
a22d7fc1 | 425 | int overloaded; |
917b627d | 426 | struct plist_head pushable_tasks; |
fa85ae24 | 427 | #endif |
6f505b16 | 428 | int rt_throttled; |
fa85ae24 | 429 | u64 rt_time; |
ac086bc2 | 430 | u64 rt_runtime; |
ea736ed5 | 431 | /* Nests inside the rq lock: */ |
0986b11b | 432 | raw_spinlock_t rt_runtime_lock; |
6f505b16 | 433 | |
052f1dc7 | 434 | #ifdef CONFIG_RT_GROUP_SCHED |
23b0fdfc PZ |
435 | unsigned long rt_nr_boosted; |
436 | ||
6f505b16 PZ |
437 | struct rq *rq; |
438 | struct list_head leaf_rt_rq_list; | |
439 | struct task_group *tg; | |
6f505b16 | 440 | #endif |
6aa645ea IM |
441 | }; |
442 | ||
57d885fe GH |
443 | #ifdef CONFIG_SMP |
444 | ||
445 | /* | |
446 | * We add the notion of a root-domain which will be used to define per-domain | |
0eab9146 IM |
447 | * variables. Each exclusive cpuset essentially defines an island domain by |
448 | * fully partitioning the member cpus from any other cpuset. Whenever a new | |
57d885fe GH |
449 | * exclusive cpuset is created, we also create and attach a new root-domain |
450 | * object. | |
451 | * | |
57d885fe GH |
452 | */ |
453 | struct root_domain { | |
454 | atomic_t refcount; | |
c6c4927b RR |
455 | cpumask_var_t span; |
456 | cpumask_var_t online; | |
637f5085 | 457 | |
0eab9146 | 458 | /* |
637f5085 GH |
459 | * The "RT overload" flag: it gets set if a CPU has more than |
460 | * one runnable RT task. | |
461 | */ | |
c6c4927b | 462 | cpumask_var_t rto_mask; |
0eab9146 | 463 | atomic_t rto_count; |
6e0534f2 GH |
464 | #ifdef CONFIG_SMP |
465 | struct cpupri cpupri; | |
466 | #endif | |
57d885fe GH |
467 | }; |
468 | ||
dc938520 GH |
469 | /* |
470 | * By default the system creates a single root-domain with all cpus as | |
471 | * members (mimicking the global state we have today). | |
472 | */ | |
57d885fe GH |
473 | static struct root_domain def_root_domain; |
474 | ||
475 | #endif | |
476 | ||
1da177e4 LT |
477 | /* |
478 | * This is the main, per-CPU runqueue data structure. | |
479 | * | |
480 | * Locking rule: those places that want to lock multiple runqueues | |
481 | * (such as the load balancing or the thread migration code), lock | |
482 | * acquire operations must be ordered by ascending &runqueue. | |
483 | */ | |
70b97a7f | 484 | struct rq { |
d8016491 | 485 | /* runqueue lock: */ |
05fa785c | 486 | raw_spinlock_t lock; |
1da177e4 LT |
487 | |
488 | /* | |
489 | * nr_running and cpu_load should be in the same cacheline because | |
490 | * remote CPUs use both these fields when doing load calculation. | |
491 | */ | |
492 | unsigned long nr_running; | |
6aa645ea IM |
493 | #define CPU_LOAD_IDX_MAX 5 |
494 | unsigned long cpu_load[CPU_LOAD_IDX_MAX]; | |
46cb4b7c SS |
495 | #ifdef CONFIG_NO_HZ |
496 | unsigned char in_nohz_recently; | |
497 | #endif | |
d8016491 IM |
498 | /* capture load from *all* tasks on this cpu: */ |
499 | struct load_weight load; | |
6aa645ea IM |
500 | unsigned long nr_load_updates; |
501 | u64 nr_switches; | |
502 | ||
503 | struct cfs_rq cfs; | |
6f505b16 | 504 | struct rt_rq rt; |
6f505b16 | 505 | |
6aa645ea | 506 | #ifdef CONFIG_FAIR_GROUP_SCHED |
d8016491 IM |
507 | /* list of leaf cfs_rq on this cpu: */ |
508 | struct list_head leaf_cfs_rq_list; | |
052f1dc7 PZ |
509 | #endif |
510 | #ifdef CONFIG_RT_GROUP_SCHED | |
6f505b16 | 511 | struct list_head leaf_rt_rq_list; |
1da177e4 | 512 | #endif |
1da177e4 LT |
513 | |
514 | /* | |
515 | * This is part of a global counter where only the total sum | |
516 | * over all CPUs matters. A task can increase this counter on | |
517 | * one CPU and if it got migrated afterwards it may decrease | |
518 | * it on another CPU. Always updated under the runqueue lock: | |
519 | */ | |
520 | unsigned long nr_uninterruptible; | |
521 | ||
36c8b586 | 522 | struct task_struct *curr, *idle; |
c9819f45 | 523 | unsigned long next_balance; |
1da177e4 | 524 | struct mm_struct *prev_mm; |
6aa645ea | 525 | |
3e51f33f | 526 | u64 clock; |
6aa645ea | 527 | |
1da177e4 LT |
528 | atomic_t nr_iowait; |
529 | ||
530 | #ifdef CONFIG_SMP | |
0eab9146 | 531 | struct root_domain *rd; |
1da177e4 LT |
532 | struct sched_domain *sd; |
533 | ||
a0a522ce | 534 | unsigned char idle_at_tick; |
1da177e4 | 535 | /* For active balancing */ |
3f029d3c | 536 | int post_schedule; |
1da177e4 LT |
537 | int active_balance; |
538 | int push_cpu; | |
d8016491 IM |
539 | /* cpu of this runqueue: */ |
540 | int cpu; | |
1f11eb6a | 541 | int online; |
1da177e4 | 542 | |
a8a51d5e | 543 | unsigned long avg_load_per_task; |
1da177e4 | 544 | |
36c8b586 | 545 | struct task_struct *migration_thread; |
1da177e4 | 546 | struct list_head migration_queue; |
e9e9250b PZ |
547 | |
548 | u64 rt_avg; | |
549 | u64 age_stamp; | |
1b9508f6 MG |
550 | u64 idle_stamp; |
551 | u64 avg_idle; | |
1da177e4 LT |
552 | #endif |
553 | ||
dce48a84 TG |
554 | /* calc_load related fields */ |
555 | unsigned long calc_load_update; | |
556 | long calc_load_active; | |
557 | ||
8f4d37ec | 558 | #ifdef CONFIG_SCHED_HRTICK |
31656519 PZ |
559 | #ifdef CONFIG_SMP |
560 | int hrtick_csd_pending; | |
561 | struct call_single_data hrtick_csd; | |
562 | #endif | |
8f4d37ec PZ |
563 | struct hrtimer hrtick_timer; |
564 | #endif | |
565 | ||
1da177e4 LT |
566 | #ifdef CONFIG_SCHEDSTATS |
567 | /* latency stats */ | |
568 | struct sched_info rq_sched_info; | |
9c2c4802 KC |
569 | unsigned long long rq_cpu_time; |
570 | /* could above be rq->cfs_rq.exec_clock + rq->rt_rq.rt_runtime ? */ | |
1da177e4 LT |
571 | |
572 | /* sys_sched_yield() stats */ | |
480b9434 | 573 | unsigned int yld_count; |
1da177e4 LT |
574 | |
575 | /* schedule() stats */ | |
480b9434 KC |
576 | unsigned int sched_switch; |
577 | unsigned int sched_count; | |
578 | unsigned int sched_goidle; | |
1da177e4 LT |
579 | |
580 | /* try_to_wake_up() stats */ | |
480b9434 KC |
581 | unsigned int ttwu_count; |
582 | unsigned int ttwu_local; | |
b8efb561 IM |
583 | |
584 | /* BKL stats */ | |
480b9434 | 585 | unsigned int bkl_count; |
1da177e4 LT |
586 | #endif |
587 | }; | |
588 | ||
f34e3b61 | 589 | static DEFINE_PER_CPU_SHARED_ALIGNED(struct rq, runqueues); |
1da177e4 | 590 | |
7d478721 PZ |
591 | static inline |
592 | void check_preempt_curr(struct rq *rq, struct task_struct *p, int flags) | |
dd41f596 | 593 | { |
7d478721 | 594 | rq->curr->sched_class->check_preempt_curr(rq, p, flags); |
dd41f596 IM |
595 | } |
596 | ||
0a2966b4 CL |
597 | static inline int cpu_of(struct rq *rq) |
598 | { | |
599 | #ifdef CONFIG_SMP | |
600 | return rq->cpu; | |
601 | #else | |
602 | return 0; | |
603 | #endif | |
604 | } | |
605 | ||
497f0ab3 | 606 | #define rcu_dereference_check_sched_domain(p) \ |
d11c563d PM |
607 | rcu_dereference_check((p), \ |
608 | rcu_read_lock_sched_held() || \ | |
609 | lockdep_is_held(&sched_domains_mutex)) | |
610 | ||
674311d5 NP |
611 | /* |
612 | * The domain tree (rq->sd) is protected by RCU's quiescent state transition. | |
1a20ff27 | 613 | * See detach_destroy_domains: synchronize_sched for details. |
674311d5 NP |
614 | * |
615 | * The domain tree of any CPU may only be accessed from within | |
616 | * preempt-disabled sections. | |
617 | */ | |
48f24c4d | 618 | #define for_each_domain(cpu, __sd) \ |
497f0ab3 | 619 | for (__sd = rcu_dereference_check_sched_domain(cpu_rq(cpu)->sd); __sd; __sd = __sd->parent) |
1da177e4 LT |
620 | |
621 | #define cpu_rq(cpu) (&per_cpu(runqueues, (cpu))) | |
622 | #define this_rq() (&__get_cpu_var(runqueues)) | |
623 | #define task_rq(p) cpu_rq(task_cpu(p)) | |
624 | #define cpu_curr(cpu) (cpu_rq(cpu)->curr) | |
54d35f29 | 625 | #define raw_rq() (&__raw_get_cpu_var(runqueues)) |
1da177e4 | 626 | |
aa9c4c0f | 627 | inline void update_rq_clock(struct rq *rq) |
3e51f33f PZ |
628 | { |
629 | rq->clock = sched_clock_cpu(cpu_of(rq)); | |
630 | } | |
631 | ||
bf5c91ba IM |
632 | /* |
633 | * Tunables that become constants when CONFIG_SCHED_DEBUG is off: | |
634 | */ | |
635 | #ifdef CONFIG_SCHED_DEBUG | |
636 | # define const_debug __read_mostly | |
637 | #else | |
638 | # define const_debug static const | |
639 | #endif | |
640 | ||
017730c1 IM |
641 | /** |
642 | * runqueue_is_locked | |
e17b38bf | 643 | * @cpu: the processor in question. |
017730c1 IM |
644 | * |
645 | * Returns true if the current cpu runqueue is locked. | |
646 | * This interface allows printk to be called with the runqueue lock | |
647 | * held and know whether or not it is OK to wake up the klogd. | |
648 | */ | |
89f19f04 | 649 | int runqueue_is_locked(int cpu) |
017730c1 | 650 | { |
05fa785c | 651 | return raw_spin_is_locked(&cpu_rq(cpu)->lock); |
017730c1 IM |
652 | } |
653 | ||
bf5c91ba IM |
654 | /* |
655 | * Debugging: various feature bits | |
656 | */ | |
f00b45c1 PZ |
657 | |
658 | #define SCHED_FEAT(name, enabled) \ | |
659 | __SCHED_FEAT_##name , | |
660 | ||
bf5c91ba | 661 | enum { |
f00b45c1 | 662 | #include "sched_features.h" |
bf5c91ba IM |
663 | }; |
664 | ||
f00b45c1 PZ |
665 | #undef SCHED_FEAT |
666 | ||
667 | #define SCHED_FEAT(name, enabled) \ | |
668 | (1UL << __SCHED_FEAT_##name) * enabled | | |
669 | ||
bf5c91ba | 670 | const_debug unsigned int sysctl_sched_features = |
f00b45c1 PZ |
671 | #include "sched_features.h" |
672 | 0; | |
673 | ||
674 | #undef SCHED_FEAT | |
675 | ||
676 | #ifdef CONFIG_SCHED_DEBUG | |
677 | #define SCHED_FEAT(name, enabled) \ | |
678 | #name , | |
679 | ||
983ed7a6 | 680 | static __read_mostly char *sched_feat_names[] = { |
f00b45c1 PZ |
681 | #include "sched_features.h" |
682 | NULL | |
683 | }; | |
684 | ||
685 | #undef SCHED_FEAT | |
686 | ||
34f3a814 | 687 | static int sched_feat_show(struct seq_file *m, void *v) |
f00b45c1 | 688 | { |
f00b45c1 PZ |
689 | int i; |
690 | ||
691 | for (i = 0; sched_feat_names[i]; i++) { | |
34f3a814 LZ |
692 | if (!(sysctl_sched_features & (1UL << i))) |
693 | seq_puts(m, "NO_"); | |
694 | seq_printf(m, "%s ", sched_feat_names[i]); | |
f00b45c1 | 695 | } |
34f3a814 | 696 | seq_puts(m, "\n"); |
f00b45c1 | 697 | |
34f3a814 | 698 | return 0; |
f00b45c1 PZ |
699 | } |
700 | ||
701 | static ssize_t | |
702 | sched_feat_write(struct file *filp, const char __user *ubuf, | |
703 | size_t cnt, loff_t *ppos) | |
704 | { | |
705 | char buf[64]; | |
706 | char *cmp = buf; | |
707 | int neg = 0; | |
708 | int i; | |
709 | ||
710 | if (cnt > 63) | |
711 | cnt = 63; | |
712 | ||
713 | if (copy_from_user(&buf, ubuf, cnt)) | |
714 | return -EFAULT; | |
715 | ||
716 | buf[cnt] = 0; | |
717 | ||
c24b7c52 | 718 | if (strncmp(buf, "NO_", 3) == 0) { |
f00b45c1 PZ |
719 | neg = 1; |
720 | cmp += 3; | |
721 | } | |
722 | ||
723 | for (i = 0; sched_feat_names[i]; i++) { | |
724 | int len = strlen(sched_feat_names[i]); | |
725 | ||
726 | if (strncmp(cmp, sched_feat_names[i], len) == 0) { | |
727 | if (neg) | |
728 | sysctl_sched_features &= ~(1UL << i); | |
729 | else | |
730 | sysctl_sched_features |= (1UL << i); | |
731 | break; | |
732 | } | |
733 | } | |
734 | ||
735 | if (!sched_feat_names[i]) | |
736 | return -EINVAL; | |
737 | ||
42994724 | 738 | *ppos += cnt; |
f00b45c1 PZ |
739 | |
740 | return cnt; | |
741 | } | |
742 | ||
34f3a814 LZ |
743 | static int sched_feat_open(struct inode *inode, struct file *filp) |
744 | { | |
745 | return single_open(filp, sched_feat_show, NULL); | |
746 | } | |
747 | ||
828c0950 | 748 | static const struct file_operations sched_feat_fops = { |
34f3a814 LZ |
749 | .open = sched_feat_open, |
750 | .write = sched_feat_write, | |
751 | .read = seq_read, | |
752 | .llseek = seq_lseek, | |
753 | .release = single_release, | |
f00b45c1 PZ |
754 | }; |
755 | ||
756 | static __init int sched_init_debug(void) | |
757 | { | |
f00b45c1 PZ |
758 | debugfs_create_file("sched_features", 0644, NULL, NULL, |
759 | &sched_feat_fops); | |
760 | ||
761 | return 0; | |
762 | } | |
763 | late_initcall(sched_init_debug); | |
764 | ||
765 | #endif | |
766 | ||
767 | #define sched_feat(x) (sysctl_sched_features & (1UL << __SCHED_FEAT_##x)) | |
bf5c91ba | 768 | |
b82d9fdd PZ |
769 | /* |
770 | * Number of tasks to iterate in a single balance run. | |
771 | * Limited because this is done with IRQs disabled. | |
772 | */ | |
773 | const_debug unsigned int sysctl_sched_nr_migrate = 32; | |
774 | ||
2398f2c6 PZ |
775 | /* |
776 | * ratelimit for updating the group shares. | |
55cd5340 | 777 | * default: 0.25ms |
2398f2c6 | 778 | */ |
55cd5340 | 779 | unsigned int sysctl_sched_shares_ratelimit = 250000; |
0bcdcf28 | 780 | unsigned int normalized_sysctl_sched_shares_ratelimit = 250000; |
2398f2c6 | 781 | |
ffda12a1 PZ |
782 | /* |
783 | * Inject some fuzzyness into changing the per-cpu group shares | |
784 | * this avoids remote rq-locks at the expense of fairness. | |
785 | * default: 4 | |
786 | */ | |
787 | unsigned int sysctl_sched_shares_thresh = 4; | |
788 | ||
e9e9250b PZ |
789 | /* |
790 | * period over which we average the RT time consumption, measured | |
791 | * in ms. | |
792 | * | |
793 | * default: 1s | |
794 | */ | |
795 | const_debug unsigned int sysctl_sched_time_avg = MSEC_PER_SEC; | |
796 | ||
fa85ae24 | 797 | /* |
9f0c1e56 | 798 | * period over which we measure -rt task cpu usage in us. |
fa85ae24 PZ |
799 | * default: 1s |
800 | */ | |
9f0c1e56 | 801 | unsigned int sysctl_sched_rt_period = 1000000; |
fa85ae24 | 802 | |
6892b75e IM |
803 | static __read_mostly int scheduler_running; |
804 | ||
9f0c1e56 PZ |
805 | /* |
806 | * part of the period that we allow rt tasks to run in us. | |
807 | * default: 0.95s | |
808 | */ | |
809 | int sysctl_sched_rt_runtime = 950000; | |
fa85ae24 | 810 | |
d0b27fa7 PZ |
811 | static inline u64 global_rt_period(void) |
812 | { | |
813 | return (u64)sysctl_sched_rt_period * NSEC_PER_USEC; | |
814 | } | |
815 | ||
816 | static inline u64 global_rt_runtime(void) | |
817 | { | |
e26873bb | 818 | if (sysctl_sched_rt_runtime < 0) |
d0b27fa7 PZ |
819 | return RUNTIME_INF; |
820 | ||
821 | return (u64)sysctl_sched_rt_runtime * NSEC_PER_USEC; | |
822 | } | |
fa85ae24 | 823 | |
1da177e4 | 824 | #ifndef prepare_arch_switch |
4866cde0 NP |
825 | # define prepare_arch_switch(next) do { } while (0) |
826 | #endif | |
827 | #ifndef finish_arch_switch | |
828 | # define finish_arch_switch(prev) do { } while (0) | |
829 | #endif | |
830 | ||
051a1d1a DA |
831 | static inline int task_current(struct rq *rq, struct task_struct *p) |
832 | { | |
833 | return rq->curr == p; | |
834 | } | |
835 | ||
4866cde0 | 836 | #ifndef __ARCH_WANT_UNLOCKED_CTXSW |
70b97a7f | 837 | static inline int task_running(struct rq *rq, struct task_struct *p) |
4866cde0 | 838 | { |
051a1d1a | 839 | return task_current(rq, p); |
4866cde0 NP |
840 | } |
841 | ||
70b97a7f | 842 | static inline void prepare_lock_switch(struct rq *rq, struct task_struct *next) |
4866cde0 NP |
843 | { |
844 | } | |
845 | ||
70b97a7f | 846 | static inline void finish_lock_switch(struct rq *rq, struct task_struct *prev) |
4866cde0 | 847 | { |
da04c035 IM |
848 | #ifdef CONFIG_DEBUG_SPINLOCK |
849 | /* this is a valid case when another task releases the spinlock */ | |
850 | rq->lock.owner = current; | |
851 | #endif | |
8a25d5de IM |
852 | /* |
853 | * If we are tracking spinlock dependencies then we have to | |
854 | * fix up the runqueue lock - which gets 'carried over' from | |
855 | * prev into current: | |
856 | */ | |
857 | spin_acquire(&rq->lock.dep_map, 0, 0, _THIS_IP_); | |
858 | ||
05fa785c | 859 | raw_spin_unlock_irq(&rq->lock); |
4866cde0 NP |
860 | } |
861 | ||
862 | #else /* __ARCH_WANT_UNLOCKED_CTXSW */ | |
70b97a7f | 863 | static inline int task_running(struct rq *rq, struct task_struct *p) |
4866cde0 NP |
864 | { |
865 | #ifdef CONFIG_SMP | |
866 | return p->oncpu; | |
867 | #else | |
051a1d1a | 868 | return task_current(rq, p); |
4866cde0 NP |
869 | #endif |
870 | } | |
871 | ||
70b97a7f | 872 | static inline void prepare_lock_switch(struct rq *rq, struct task_struct *next) |
4866cde0 NP |
873 | { |
874 | #ifdef CONFIG_SMP | |
875 | /* | |
876 | * We can optimise this out completely for !SMP, because the | |
877 | * SMP rebalancing from interrupt is the only thing that cares | |
878 | * here. | |
879 | */ | |
880 | next->oncpu = 1; | |
881 | #endif | |
882 | #ifdef __ARCH_WANT_INTERRUPTS_ON_CTXSW | |
05fa785c | 883 | raw_spin_unlock_irq(&rq->lock); |
4866cde0 | 884 | #else |
05fa785c | 885 | raw_spin_unlock(&rq->lock); |
4866cde0 NP |
886 | #endif |
887 | } | |
888 | ||
70b97a7f | 889 | static inline void finish_lock_switch(struct rq *rq, struct task_struct *prev) |
4866cde0 NP |
890 | { |
891 | #ifdef CONFIG_SMP | |
892 | /* | |
893 | * After ->oncpu is cleared, the task can be moved to a different CPU. | |
894 | * We must ensure this doesn't happen until the switch is completely | |
895 | * finished. | |
896 | */ | |
897 | smp_wmb(); | |
898 | prev->oncpu = 0; | |
899 | #endif | |
900 | #ifndef __ARCH_WANT_INTERRUPTS_ON_CTXSW | |
901 | local_irq_enable(); | |
1da177e4 | 902 | #endif |
4866cde0 NP |
903 | } |
904 | #endif /* __ARCH_WANT_UNLOCKED_CTXSW */ | |
1da177e4 | 905 | |
0970d299 PZ |
906 | /* |
907 | * Check whether the task is waking, we use this to synchronize against | |
908 | * ttwu() so that task_cpu() reports a stable number. | |
909 | * | |
910 | * We need to make an exception for PF_STARTING tasks because the fork | |
911 | * path might require task_rq_lock() to work, eg. it can call | |
912 | * set_cpus_allowed_ptr() from the cpuset clone_ns code. | |
913 | */ | |
914 | static inline int task_is_waking(struct task_struct *p) | |
915 | { | |
916 | return unlikely((p->state == TASK_WAKING) && !(p->flags & PF_STARTING)); | |
917 | } | |
918 | ||
b29739f9 IM |
919 | /* |
920 | * __task_rq_lock - lock the runqueue a given task resides on. | |
921 | * Must be called interrupts disabled. | |
922 | */ | |
70b97a7f | 923 | static inline struct rq *__task_rq_lock(struct task_struct *p) |
b29739f9 IM |
924 | __acquires(rq->lock) |
925 | { | |
0970d299 PZ |
926 | struct rq *rq; |
927 | ||
3a5c359a | 928 | for (;;) { |
0970d299 PZ |
929 | while (task_is_waking(p)) |
930 | cpu_relax(); | |
931 | rq = task_rq(p); | |
05fa785c | 932 | raw_spin_lock(&rq->lock); |
0970d299 | 933 | if (likely(rq == task_rq(p) && !task_is_waking(p))) |
3a5c359a | 934 | return rq; |
05fa785c | 935 | raw_spin_unlock(&rq->lock); |
b29739f9 | 936 | } |
b29739f9 IM |
937 | } |
938 | ||
1da177e4 LT |
939 | /* |
940 | * task_rq_lock - lock the runqueue a given task resides on and disable | |
41a2d6cf | 941 | * interrupts. Note the ordering: we can safely lookup the task_rq without |
1da177e4 LT |
942 | * explicitly disabling preemption. |
943 | */ | |
70b97a7f | 944 | static struct rq *task_rq_lock(struct task_struct *p, unsigned long *flags) |
1da177e4 LT |
945 | __acquires(rq->lock) |
946 | { | |
70b97a7f | 947 | struct rq *rq; |
1da177e4 | 948 | |
3a5c359a | 949 | for (;;) { |
0970d299 PZ |
950 | while (task_is_waking(p)) |
951 | cpu_relax(); | |
3a5c359a AK |
952 | local_irq_save(*flags); |
953 | rq = task_rq(p); | |
05fa785c | 954 | raw_spin_lock(&rq->lock); |
0970d299 | 955 | if (likely(rq == task_rq(p) && !task_is_waking(p))) |
3a5c359a | 956 | return rq; |
05fa785c | 957 | raw_spin_unlock_irqrestore(&rq->lock, *flags); |
1da177e4 | 958 | } |
1da177e4 LT |
959 | } |
960 | ||
ad474cac ON |
961 | void task_rq_unlock_wait(struct task_struct *p) |
962 | { | |
963 | struct rq *rq = task_rq(p); | |
964 | ||
965 | smp_mb(); /* spin-unlock-wait is not a full memory barrier */ | |
05fa785c | 966 | raw_spin_unlock_wait(&rq->lock); |
ad474cac ON |
967 | } |
968 | ||
a9957449 | 969 | static void __task_rq_unlock(struct rq *rq) |
b29739f9 IM |
970 | __releases(rq->lock) |
971 | { | |
05fa785c | 972 | raw_spin_unlock(&rq->lock); |
b29739f9 IM |
973 | } |
974 | ||
70b97a7f | 975 | static inline void task_rq_unlock(struct rq *rq, unsigned long *flags) |
1da177e4 LT |
976 | __releases(rq->lock) |
977 | { | |
05fa785c | 978 | raw_spin_unlock_irqrestore(&rq->lock, *flags); |
1da177e4 LT |
979 | } |
980 | ||
1da177e4 | 981 | /* |
cc2a73b5 | 982 | * this_rq_lock - lock this runqueue and disable interrupts. |
1da177e4 | 983 | */ |
a9957449 | 984 | static struct rq *this_rq_lock(void) |
1da177e4 LT |
985 | __acquires(rq->lock) |
986 | { | |
70b97a7f | 987 | struct rq *rq; |
1da177e4 LT |
988 | |
989 | local_irq_disable(); | |
990 | rq = this_rq(); | |
05fa785c | 991 | raw_spin_lock(&rq->lock); |
1da177e4 LT |
992 | |
993 | return rq; | |
994 | } | |
995 | ||
8f4d37ec PZ |
996 | #ifdef CONFIG_SCHED_HRTICK |
997 | /* | |
998 | * Use HR-timers to deliver accurate preemption points. | |
999 | * | |
1000 | * Its all a bit involved since we cannot program an hrt while holding the | |
1001 | * rq->lock. So what we do is store a state in in rq->hrtick_* and ask for a | |
1002 | * reschedule event. | |
1003 | * | |
1004 | * When we get rescheduled we reprogram the hrtick_timer outside of the | |
1005 | * rq->lock. | |
1006 | */ | |
8f4d37ec PZ |
1007 | |
1008 | /* | |
1009 | * Use hrtick when: | |
1010 | * - enabled by features | |
1011 | * - hrtimer is actually high res | |
1012 | */ | |
1013 | static inline int hrtick_enabled(struct rq *rq) | |
1014 | { | |
1015 | if (!sched_feat(HRTICK)) | |
1016 | return 0; | |
ba42059f | 1017 | if (!cpu_active(cpu_of(rq))) |
b328ca18 | 1018 | return 0; |
8f4d37ec PZ |
1019 | return hrtimer_is_hres_active(&rq->hrtick_timer); |
1020 | } | |
1021 | ||
8f4d37ec PZ |
1022 | static void hrtick_clear(struct rq *rq) |
1023 | { | |
1024 | if (hrtimer_active(&rq->hrtick_timer)) | |
1025 | hrtimer_cancel(&rq->hrtick_timer); | |
1026 | } | |
1027 | ||
8f4d37ec PZ |
1028 | /* |
1029 | * High-resolution timer tick. | |
1030 | * Runs from hardirq context with interrupts disabled. | |
1031 | */ | |
1032 | static enum hrtimer_restart hrtick(struct hrtimer *timer) | |
1033 | { | |
1034 | struct rq *rq = container_of(timer, struct rq, hrtick_timer); | |
1035 | ||
1036 | WARN_ON_ONCE(cpu_of(rq) != smp_processor_id()); | |
1037 | ||
05fa785c | 1038 | raw_spin_lock(&rq->lock); |
3e51f33f | 1039 | update_rq_clock(rq); |
8f4d37ec | 1040 | rq->curr->sched_class->task_tick(rq, rq->curr, 1); |
05fa785c | 1041 | raw_spin_unlock(&rq->lock); |
8f4d37ec PZ |
1042 | |
1043 | return HRTIMER_NORESTART; | |
1044 | } | |
1045 | ||
95e904c7 | 1046 | #ifdef CONFIG_SMP |
31656519 PZ |
1047 | /* |
1048 | * called from hardirq (IPI) context | |
1049 | */ | |
1050 | static void __hrtick_start(void *arg) | |
b328ca18 | 1051 | { |
31656519 | 1052 | struct rq *rq = arg; |
b328ca18 | 1053 | |
05fa785c | 1054 | raw_spin_lock(&rq->lock); |
31656519 PZ |
1055 | hrtimer_restart(&rq->hrtick_timer); |
1056 | rq->hrtick_csd_pending = 0; | |
05fa785c | 1057 | raw_spin_unlock(&rq->lock); |
b328ca18 PZ |
1058 | } |
1059 | ||
31656519 PZ |
1060 | /* |
1061 | * Called to set the hrtick timer state. | |
1062 | * | |
1063 | * called with rq->lock held and irqs disabled | |
1064 | */ | |
1065 | static void hrtick_start(struct rq *rq, u64 delay) | |
b328ca18 | 1066 | { |
31656519 PZ |
1067 | struct hrtimer *timer = &rq->hrtick_timer; |
1068 | ktime_t time = ktime_add_ns(timer->base->get_time(), delay); | |
b328ca18 | 1069 | |
cc584b21 | 1070 | hrtimer_set_expires(timer, time); |
31656519 PZ |
1071 | |
1072 | if (rq == this_rq()) { | |
1073 | hrtimer_restart(timer); | |
1074 | } else if (!rq->hrtick_csd_pending) { | |
6e275637 | 1075 | __smp_call_function_single(cpu_of(rq), &rq->hrtick_csd, 0); |
31656519 PZ |
1076 | rq->hrtick_csd_pending = 1; |
1077 | } | |
b328ca18 PZ |
1078 | } |
1079 | ||
1080 | static int | |
1081 | hotplug_hrtick(struct notifier_block *nfb, unsigned long action, void *hcpu) | |
1082 | { | |
1083 | int cpu = (int)(long)hcpu; | |
1084 | ||
1085 | switch (action) { | |
1086 | case CPU_UP_CANCELED: | |
1087 | case CPU_UP_CANCELED_FROZEN: | |
1088 | case CPU_DOWN_PREPARE: | |
1089 | case CPU_DOWN_PREPARE_FROZEN: | |
1090 | case CPU_DEAD: | |
1091 | case CPU_DEAD_FROZEN: | |
31656519 | 1092 | hrtick_clear(cpu_rq(cpu)); |
b328ca18 PZ |
1093 | return NOTIFY_OK; |
1094 | } | |
1095 | ||
1096 | return NOTIFY_DONE; | |
1097 | } | |
1098 | ||
fa748203 | 1099 | static __init void init_hrtick(void) |
b328ca18 PZ |
1100 | { |
1101 | hotcpu_notifier(hotplug_hrtick, 0); | |
1102 | } | |
31656519 PZ |
1103 | #else |
1104 | /* | |
1105 | * Called to set the hrtick timer state. | |
1106 | * | |
1107 | * called with rq->lock held and irqs disabled | |
1108 | */ | |
1109 | static void hrtick_start(struct rq *rq, u64 delay) | |
1110 | { | |
7f1e2ca9 | 1111 | __hrtimer_start_range_ns(&rq->hrtick_timer, ns_to_ktime(delay), 0, |
5c333864 | 1112 | HRTIMER_MODE_REL_PINNED, 0); |
31656519 | 1113 | } |
b328ca18 | 1114 | |
006c75f1 | 1115 | static inline void init_hrtick(void) |
8f4d37ec | 1116 | { |
8f4d37ec | 1117 | } |
31656519 | 1118 | #endif /* CONFIG_SMP */ |
8f4d37ec | 1119 | |
31656519 | 1120 | static void init_rq_hrtick(struct rq *rq) |
8f4d37ec | 1121 | { |
31656519 PZ |
1122 | #ifdef CONFIG_SMP |
1123 | rq->hrtick_csd_pending = 0; | |
8f4d37ec | 1124 | |
31656519 PZ |
1125 | rq->hrtick_csd.flags = 0; |
1126 | rq->hrtick_csd.func = __hrtick_start; | |
1127 | rq->hrtick_csd.info = rq; | |
1128 | #endif | |
8f4d37ec | 1129 | |
31656519 PZ |
1130 | hrtimer_init(&rq->hrtick_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); |
1131 | rq->hrtick_timer.function = hrtick; | |
8f4d37ec | 1132 | } |
006c75f1 | 1133 | #else /* CONFIG_SCHED_HRTICK */ |
8f4d37ec PZ |
1134 | static inline void hrtick_clear(struct rq *rq) |
1135 | { | |
1136 | } | |
1137 | ||
8f4d37ec PZ |
1138 | static inline void init_rq_hrtick(struct rq *rq) |
1139 | { | |
1140 | } | |
1141 | ||
b328ca18 PZ |
1142 | static inline void init_hrtick(void) |
1143 | { | |
1144 | } | |
006c75f1 | 1145 | #endif /* CONFIG_SCHED_HRTICK */ |
8f4d37ec | 1146 | |
c24d20db IM |
1147 | /* |
1148 | * resched_task - mark a task 'to be rescheduled now'. | |
1149 | * | |
1150 | * On UP this means the setting of the need_resched flag, on SMP it | |
1151 | * might also involve a cross-CPU call to trigger the scheduler on | |
1152 | * the target CPU. | |
1153 | */ | |
1154 | #ifdef CONFIG_SMP | |
1155 | ||
1156 | #ifndef tsk_is_polling | |
1157 | #define tsk_is_polling(t) test_tsk_thread_flag(t, TIF_POLLING_NRFLAG) | |
1158 | #endif | |
1159 | ||
31656519 | 1160 | static void resched_task(struct task_struct *p) |
c24d20db IM |
1161 | { |
1162 | int cpu; | |
1163 | ||
05fa785c | 1164 | assert_raw_spin_locked(&task_rq(p)->lock); |
c24d20db | 1165 | |
5ed0cec0 | 1166 | if (test_tsk_need_resched(p)) |
c24d20db IM |
1167 | return; |
1168 | ||
5ed0cec0 | 1169 | set_tsk_need_resched(p); |
c24d20db IM |
1170 | |
1171 | cpu = task_cpu(p); | |
1172 | if (cpu == smp_processor_id()) | |
1173 | return; | |
1174 | ||
1175 | /* NEED_RESCHED must be visible before we test polling */ | |
1176 | smp_mb(); | |
1177 | if (!tsk_is_polling(p)) | |
1178 | smp_send_reschedule(cpu); | |
1179 | } | |
1180 | ||
1181 | static void resched_cpu(int cpu) | |
1182 | { | |
1183 | struct rq *rq = cpu_rq(cpu); | |
1184 | unsigned long flags; | |
1185 | ||
05fa785c | 1186 | if (!raw_spin_trylock_irqsave(&rq->lock, flags)) |
c24d20db IM |
1187 | return; |
1188 | resched_task(cpu_curr(cpu)); | |
05fa785c | 1189 | raw_spin_unlock_irqrestore(&rq->lock, flags); |
c24d20db | 1190 | } |
06d8308c TG |
1191 | |
1192 | #ifdef CONFIG_NO_HZ | |
1193 | /* | |
1194 | * When add_timer_on() enqueues a timer into the timer wheel of an | |
1195 | * idle CPU then this timer might expire before the next timer event | |
1196 | * which is scheduled to wake up that CPU. In case of a completely | |
1197 | * idle system the next event might even be infinite time into the | |
1198 | * future. wake_up_idle_cpu() ensures that the CPU is woken up and | |
1199 | * leaves the inner idle loop so the newly added timer is taken into | |
1200 | * account when the CPU goes back to idle and evaluates the timer | |
1201 | * wheel for the next timer event. | |
1202 | */ | |
1203 | void wake_up_idle_cpu(int cpu) | |
1204 | { | |
1205 | struct rq *rq = cpu_rq(cpu); | |
1206 | ||
1207 | if (cpu == smp_processor_id()) | |
1208 | return; | |
1209 | ||
1210 | /* | |
1211 | * This is safe, as this function is called with the timer | |
1212 | * wheel base lock of (cpu) held. When the CPU is on the way | |
1213 | * to idle and has not yet set rq->curr to idle then it will | |
1214 | * be serialized on the timer wheel base lock and take the new | |
1215 | * timer into account automatically. | |
1216 | */ | |
1217 | if (rq->curr != rq->idle) | |
1218 | return; | |
1219 | ||
1220 | /* | |
1221 | * We can set TIF_RESCHED on the idle task of the other CPU | |
1222 | * lockless. The worst case is that the other CPU runs the | |
1223 | * idle task through an additional NOOP schedule() | |
1224 | */ | |
5ed0cec0 | 1225 | set_tsk_need_resched(rq->idle); |
06d8308c TG |
1226 | |
1227 | /* NEED_RESCHED must be visible before we test polling */ | |
1228 | smp_mb(); | |
1229 | if (!tsk_is_polling(rq->idle)) | |
1230 | smp_send_reschedule(cpu); | |
1231 | } | |
6d6bc0ad | 1232 | #endif /* CONFIG_NO_HZ */ |
06d8308c | 1233 | |
e9e9250b PZ |
1234 | static u64 sched_avg_period(void) |
1235 | { | |
1236 | return (u64)sysctl_sched_time_avg * NSEC_PER_MSEC / 2; | |
1237 | } | |
1238 | ||
1239 | static void sched_avg_update(struct rq *rq) | |
1240 | { | |
1241 | s64 period = sched_avg_period(); | |
1242 | ||
1243 | while ((s64)(rq->clock - rq->age_stamp) > period) { | |
1244 | rq->age_stamp += period; | |
1245 | rq->rt_avg /= 2; | |
1246 | } | |
1247 | } | |
1248 | ||
1249 | static void sched_rt_avg_update(struct rq *rq, u64 rt_delta) | |
1250 | { | |
1251 | rq->rt_avg += rt_delta; | |
1252 | sched_avg_update(rq); | |
1253 | } | |
1254 | ||
6d6bc0ad | 1255 | #else /* !CONFIG_SMP */ |
31656519 | 1256 | static void resched_task(struct task_struct *p) |
c24d20db | 1257 | { |
05fa785c | 1258 | assert_raw_spin_locked(&task_rq(p)->lock); |
31656519 | 1259 | set_tsk_need_resched(p); |
c24d20db | 1260 | } |
e9e9250b PZ |
1261 | |
1262 | static void sched_rt_avg_update(struct rq *rq, u64 rt_delta) | |
1263 | { | |
1264 | } | |
6d6bc0ad | 1265 | #endif /* CONFIG_SMP */ |
c24d20db | 1266 | |
45bf76df IM |
1267 | #if BITS_PER_LONG == 32 |
1268 | # define WMULT_CONST (~0UL) | |
1269 | #else | |
1270 | # define WMULT_CONST (1UL << 32) | |
1271 | #endif | |
1272 | ||
1273 | #define WMULT_SHIFT 32 | |
1274 | ||
194081eb IM |
1275 | /* |
1276 | * Shift right and round: | |
1277 | */ | |
cf2ab469 | 1278 | #define SRR(x, y) (((x) + (1UL << ((y) - 1))) >> (y)) |
194081eb | 1279 | |
a7be37ac PZ |
1280 | /* |
1281 | * delta *= weight / lw | |
1282 | */ | |
cb1c4fc9 | 1283 | static unsigned long |
45bf76df IM |
1284 | calc_delta_mine(unsigned long delta_exec, unsigned long weight, |
1285 | struct load_weight *lw) | |
1286 | { | |
1287 | u64 tmp; | |
1288 | ||
7a232e03 LJ |
1289 | if (!lw->inv_weight) { |
1290 | if (BITS_PER_LONG > 32 && unlikely(lw->weight >= WMULT_CONST)) | |
1291 | lw->inv_weight = 1; | |
1292 | else | |
1293 | lw->inv_weight = 1 + (WMULT_CONST-lw->weight/2) | |
1294 | / (lw->weight+1); | |
1295 | } | |
45bf76df IM |
1296 | |
1297 | tmp = (u64)delta_exec * weight; | |
1298 | /* | |
1299 | * Check whether we'd overflow the 64-bit multiplication: | |
1300 | */ | |
194081eb | 1301 | if (unlikely(tmp > WMULT_CONST)) |
cf2ab469 | 1302 | tmp = SRR(SRR(tmp, WMULT_SHIFT/2) * lw->inv_weight, |
194081eb IM |
1303 | WMULT_SHIFT/2); |
1304 | else | |
cf2ab469 | 1305 | tmp = SRR(tmp * lw->inv_weight, WMULT_SHIFT); |
45bf76df | 1306 | |
ecf691da | 1307 | return (unsigned long)min(tmp, (u64)(unsigned long)LONG_MAX); |
45bf76df IM |
1308 | } |
1309 | ||
1091985b | 1310 | static inline void update_load_add(struct load_weight *lw, unsigned long inc) |
45bf76df IM |
1311 | { |
1312 | lw->weight += inc; | |
e89996ae | 1313 | lw->inv_weight = 0; |
45bf76df IM |
1314 | } |
1315 | ||
1091985b | 1316 | static inline void update_load_sub(struct load_weight *lw, unsigned long dec) |
45bf76df IM |
1317 | { |
1318 | lw->weight -= dec; | |
e89996ae | 1319 | lw->inv_weight = 0; |
45bf76df IM |
1320 | } |
1321 | ||
2dd73a4f PW |
1322 | /* |
1323 | * To aid in avoiding the subversion of "niceness" due to uneven distribution | |
1324 | * of tasks with abnormal "nice" values across CPUs the contribution that | |
1325 | * each task makes to its run queue's load is weighted according to its | |
41a2d6cf | 1326 | * scheduling class and "nice" value. For SCHED_NORMAL tasks this is just a |
2dd73a4f PW |
1327 | * scaled version of the new time slice allocation that they receive on time |
1328 | * slice expiry etc. | |
1329 | */ | |
1330 | ||
cce7ade8 PZ |
1331 | #define WEIGHT_IDLEPRIO 3 |
1332 | #define WMULT_IDLEPRIO 1431655765 | |
dd41f596 IM |
1333 | |
1334 | /* | |
1335 | * Nice levels are multiplicative, with a gentle 10% change for every | |
1336 | * nice level changed. I.e. when a CPU-bound task goes from nice 0 to | |
1337 | * nice 1, it will get ~10% less CPU time than another CPU-bound task | |
1338 | * that remained on nice 0. | |
1339 | * | |
1340 | * The "10% effect" is relative and cumulative: from _any_ nice level, | |
1341 | * if you go up 1 level, it's -10% CPU usage, if you go down 1 level | |
f9153ee6 IM |
1342 | * it's +10% CPU usage. (to achieve that we use a multiplier of 1.25. |
1343 | * If a task goes up by ~10% and another task goes down by ~10% then | |
1344 | * the relative distance between them is ~25%.) | |
dd41f596 IM |
1345 | */ |
1346 | static const int prio_to_weight[40] = { | |
254753dc IM |
1347 | /* -20 */ 88761, 71755, 56483, 46273, 36291, |
1348 | /* -15 */ 29154, 23254, 18705, 14949, 11916, | |
1349 | /* -10 */ 9548, 7620, 6100, 4904, 3906, | |
1350 | /* -5 */ 3121, 2501, 1991, 1586, 1277, | |
1351 | /* 0 */ 1024, 820, 655, 526, 423, | |
1352 | /* 5 */ 335, 272, 215, 172, 137, | |
1353 | /* 10 */ 110, 87, 70, 56, 45, | |
1354 | /* 15 */ 36, 29, 23, 18, 15, | |
dd41f596 IM |
1355 | }; |
1356 | ||
5714d2de IM |
1357 | /* |
1358 | * Inverse (2^32/x) values of the prio_to_weight[] array, precalculated. | |
1359 | * | |
1360 | * In cases where the weight does not change often, we can use the | |
1361 | * precalculated inverse to speed up arithmetics by turning divisions | |
1362 | * into multiplications: | |
1363 | */ | |
dd41f596 | 1364 | static const u32 prio_to_wmult[40] = { |
254753dc IM |
1365 | /* -20 */ 48388, 59856, 76040, 92818, 118348, |
1366 | /* -15 */ 147320, 184698, 229616, 287308, 360437, | |
1367 | /* -10 */ 449829, 563644, 704093, 875809, 1099582, | |
1368 | /* -5 */ 1376151, 1717300, 2157191, 2708050, 3363326, | |
1369 | /* 0 */ 4194304, 5237765, 6557202, 8165337, 10153587, | |
1370 | /* 5 */ 12820798, 15790321, 19976592, 24970740, 31350126, | |
1371 | /* 10 */ 39045157, 49367440, 61356676, 76695844, 95443717, | |
1372 | /* 15 */ 119304647, 148102320, 186737708, 238609294, 286331153, | |
dd41f596 | 1373 | }; |
2dd73a4f | 1374 | |
ef12fefa BR |
1375 | /* Time spent by the tasks of the cpu accounting group executing in ... */ |
1376 | enum cpuacct_stat_index { | |
1377 | CPUACCT_STAT_USER, /* ... user mode */ | |
1378 | CPUACCT_STAT_SYSTEM, /* ... kernel mode */ | |
1379 | ||
1380 | CPUACCT_STAT_NSTATS, | |
1381 | }; | |
1382 | ||
d842de87 SV |
1383 | #ifdef CONFIG_CGROUP_CPUACCT |
1384 | static void cpuacct_charge(struct task_struct *tsk, u64 cputime); | |
ef12fefa BR |
1385 | static void cpuacct_update_stats(struct task_struct *tsk, |
1386 | enum cpuacct_stat_index idx, cputime_t val); | |
d842de87 SV |
1387 | #else |
1388 | static inline void cpuacct_charge(struct task_struct *tsk, u64 cputime) {} | |
ef12fefa BR |
1389 | static inline void cpuacct_update_stats(struct task_struct *tsk, |
1390 | enum cpuacct_stat_index idx, cputime_t val) {} | |
d842de87 SV |
1391 | #endif |
1392 | ||
18d95a28 PZ |
1393 | static inline void inc_cpu_load(struct rq *rq, unsigned long load) |
1394 | { | |
1395 | update_load_add(&rq->load, load); | |
1396 | } | |
1397 | ||
1398 | static inline void dec_cpu_load(struct rq *rq, unsigned long load) | |
1399 | { | |
1400 | update_load_sub(&rq->load, load); | |
1401 | } | |
1402 | ||
7940ca36 | 1403 | #if (defined(CONFIG_SMP) && defined(CONFIG_FAIR_GROUP_SCHED)) || defined(CONFIG_RT_GROUP_SCHED) |
eb755805 | 1404 | typedef int (*tg_visitor)(struct task_group *, void *); |
c09595f6 PZ |
1405 | |
1406 | /* | |
1407 | * Iterate the full tree, calling @down when first entering a node and @up when | |
1408 | * leaving it for the final time. | |
1409 | */ | |
eb755805 | 1410 | static int walk_tg_tree(tg_visitor down, tg_visitor up, void *data) |
c09595f6 PZ |
1411 | { |
1412 | struct task_group *parent, *child; | |
eb755805 | 1413 | int ret; |
c09595f6 PZ |
1414 | |
1415 | rcu_read_lock(); | |
1416 | parent = &root_task_group; | |
1417 | down: | |
eb755805 PZ |
1418 | ret = (*down)(parent, data); |
1419 | if (ret) | |
1420 | goto out_unlock; | |
c09595f6 PZ |
1421 | list_for_each_entry_rcu(child, &parent->children, siblings) { |
1422 | parent = child; | |
1423 | goto down; | |
1424 | ||
1425 | up: | |
1426 | continue; | |
1427 | } | |
eb755805 PZ |
1428 | ret = (*up)(parent, data); |
1429 | if (ret) | |
1430 | goto out_unlock; | |
c09595f6 PZ |
1431 | |
1432 | child = parent; | |
1433 | parent = parent->parent; | |
1434 | if (parent) | |
1435 | goto up; | |
eb755805 | 1436 | out_unlock: |
c09595f6 | 1437 | rcu_read_unlock(); |
eb755805 PZ |
1438 | |
1439 | return ret; | |
c09595f6 PZ |
1440 | } |
1441 | ||
eb755805 PZ |
1442 | static int tg_nop(struct task_group *tg, void *data) |
1443 | { | |
1444 | return 0; | |
c09595f6 | 1445 | } |
eb755805 PZ |
1446 | #endif |
1447 | ||
1448 | #ifdef CONFIG_SMP | |
f5f08f39 PZ |
1449 | /* Used instead of source_load when we know the type == 0 */ |
1450 | static unsigned long weighted_cpuload(const int cpu) | |
1451 | { | |
1452 | return cpu_rq(cpu)->load.weight; | |
1453 | } | |
1454 | ||
1455 | /* | |
1456 | * Return a low guess at the load of a migration-source cpu weighted | |
1457 | * according to the scheduling class and "nice" value. | |
1458 | * | |
1459 | * We want to under-estimate the load of migration sources, to | |
1460 | * balance conservatively. | |
1461 | */ | |
1462 | static unsigned long source_load(int cpu, int type) | |
1463 | { | |
1464 | struct rq *rq = cpu_rq(cpu); | |
1465 | unsigned long total = weighted_cpuload(cpu); | |
1466 | ||
1467 | if (type == 0 || !sched_feat(LB_BIAS)) | |
1468 | return total; | |
1469 | ||
1470 | return min(rq->cpu_load[type-1], total); | |
1471 | } | |
1472 | ||
1473 | /* | |
1474 | * Return a high guess at the load of a migration-target cpu weighted | |
1475 | * according to the scheduling class and "nice" value. | |
1476 | */ | |
1477 | static unsigned long target_load(int cpu, int type) | |
1478 | { | |
1479 | struct rq *rq = cpu_rq(cpu); | |
1480 | unsigned long total = weighted_cpuload(cpu); | |
1481 | ||
1482 | if (type == 0 || !sched_feat(LB_BIAS)) | |
1483 | return total; | |
1484 | ||
1485 | return max(rq->cpu_load[type-1], total); | |
1486 | } | |
1487 | ||
ae154be1 PZ |
1488 | static struct sched_group *group_of(int cpu) |
1489 | { | |
d11c563d | 1490 | struct sched_domain *sd = rcu_dereference_sched(cpu_rq(cpu)->sd); |
ae154be1 PZ |
1491 | |
1492 | if (!sd) | |
1493 | return NULL; | |
1494 | ||
1495 | return sd->groups; | |
1496 | } | |
1497 | ||
1498 | static unsigned long power_of(int cpu) | |
1499 | { | |
1500 | struct sched_group *group = group_of(cpu); | |
1501 | ||
1502 | if (!group) | |
1503 | return SCHED_LOAD_SCALE; | |
1504 | ||
1505 | return group->cpu_power; | |
1506 | } | |
1507 | ||
eb755805 PZ |
1508 | static int task_hot(struct task_struct *p, u64 now, struct sched_domain *sd); |
1509 | ||
1510 | static unsigned long cpu_avg_load_per_task(int cpu) | |
1511 | { | |
1512 | struct rq *rq = cpu_rq(cpu); | |
af6d596f | 1513 | unsigned long nr_running = ACCESS_ONCE(rq->nr_running); |
eb755805 | 1514 | |
4cd42620 SR |
1515 | if (nr_running) |
1516 | rq->avg_load_per_task = rq->load.weight / nr_running; | |
a2d47777 BS |
1517 | else |
1518 | rq->avg_load_per_task = 0; | |
eb755805 PZ |
1519 | |
1520 | return rq->avg_load_per_task; | |
1521 | } | |
1522 | ||
1523 | #ifdef CONFIG_FAIR_GROUP_SCHED | |
c09595f6 | 1524 | |
43cf38eb | 1525 | static __read_mostly unsigned long __percpu *update_shares_data; |
34d76c41 | 1526 | |
c09595f6 PZ |
1527 | static void __set_se_shares(struct sched_entity *se, unsigned long shares); |
1528 | ||
1529 | /* | |
1530 | * Calculate and set the cpu's group shares. | |
1531 | */ | |
34d76c41 PZ |
1532 | static void update_group_shares_cpu(struct task_group *tg, int cpu, |
1533 | unsigned long sd_shares, | |
1534 | unsigned long sd_rq_weight, | |
4a6cc4bd | 1535 | unsigned long *usd_rq_weight) |
18d95a28 | 1536 | { |
34d76c41 | 1537 | unsigned long shares, rq_weight; |
a5004278 | 1538 | int boost = 0; |
c09595f6 | 1539 | |
4a6cc4bd | 1540 | rq_weight = usd_rq_weight[cpu]; |
a5004278 PZ |
1541 | if (!rq_weight) { |
1542 | boost = 1; | |
1543 | rq_weight = NICE_0_LOAD; | |
1544 | } | |
c8cba857 | 1545 | |
c09595f6 | 1546 | /* |
a8af7246 PZ |
1547 | * \Sum_j shares_j * rq_weight_i |
1548 | * shares_i = ----------------------------- | |
1549 | * \Sum_j rq_weight_j | |
c09595f6 | 1550 | */ |
ec4e0e2f | 1551 | shares = (sd_shares * rq_weight) / sd_rq_weight; |
ffda12a1 | 1552 | shares = clamp_t(unsigned long, shares, MIN_SHARES, MAX_SHARES); |
c09595f6 | 1553 | |
ffda12a1 PZ |
1554 | if (abs(shares - tg->se[cpu]->load.weight) > |
1555 | sysctl_sched_shares_thresh) { | |
1556 | struct rq *rq = cpu_rq(cpu); | |
1557 | unsigned long flags; | |
c09595f6 | 1558 | |
05fa785c | 1559 | raw_spin_lock_irqsave(&rq->lock, flags); |
34d76c41 | 1560 | tg->cfs_rq[cpu]->rq_weight = boost ? 0 : rq_weight; |
a5004278 | 1561 | tg->cfs_rq[cpu]->shares = boost ? 0 : shares; |
ffda12a1 | 1562 | __set_se_shares(tg->se[cpu], shares); |
05fa785c | 1563 | raw_spin_unlock_irqrestore(&rq->lock, flags); |
ffda12a1 | 1564 | } |
18d95a28 | 1565 | } |
c09595f6 PZ |
1566 | |
1567 | /* | |
c8cba857 PZ |
1568 | * Re-compute the task group their per cpu shares over the given domain. |
1569 | * This needs to be done in a bottom-up fashion because the rq weight of a | |
1570 | * parent group depends on the shares of its child groups. | |
c09595f6 | 1571 | */ |
eb755805 | 1572 | static int tg_shares_up(struct task_group *tg, void *data) |
c09595f6 | 1573 | { |
cd8ad40d | 1574 | unsigned long weight, rq_weight = 0, sum_weight = 0, shares = 0; |
4a6cc4bd | 1575 | unsigned long *usd_rq_weight; |
eb755805 | 1576 | struct sched_domain *sd = data; |
34d76c41 | 1577 | unsigned long flags; |
c8cba857 | 1578 | int i; |
c09595f6 | 1579 | |
34d76c41 PZ |
1580 | if (!tg->se[0]) |
1581 | return 0; | |
1582 | ||
1583 | local_irq_save(flags); | |
4a6cc4bd | 1584 | usd_rq_weight = per_cpu_ptr(update_shares_data, smp_processor_id()); |
34d76c41 | 1585 | |
758b2cdc | 1586 | for_each_cpu(i, sched_domain_span(sd)) { |
34d76c41 | 1587 | weight = tg->cfs_rq[i]->load.weight; |
4a6cc4bd | 1588 | usd_rq_weight[i] = weight; |
34d76c41 | 1589 | |
cd8ad40d | 1590 | rq_weight += weight; |
ec4e0e2f KC |
1591 | /* |
1592 | * If there are currently no tasks on the cpu pretend there | |
1593 | * is one of average load so that when a new task gets to | |
1594 | * run here it will not get delayed by group starvation. | |
1595 | */ | |
ec4e0e2f KC |
1596 | if (!weight) |
1597 | weight = NICE_0_LOAD; | |
1598 | ||
cd8ad40d | 1599 | sum_weight += weight; |
c8cba857 | 1600 | shares += tg->cfs_rq[i]->shares; |
c09595f6 | 1601 | } |
c09595f6 | 1602 | |
cd8ad40d PZ |
1603 | if (!rq_weight) |
1604 | rq_weight = sum_weight; | |
1605 | ||
c8cba857 PZ |
1606 | if ((!shares && rq_weight) || shares > tg->shares) |
1607 | shares = tg->shares; | |
1608 | ||
1609 | if (!sd->parent || !(sd->parent->flags & SD_LOAD_BALANCE)) | |
1610 | shares = tg->shares; | |
c09595f6 | 1611 | |
758b2cdc | 1612 | for_each_cpu(i, sched_domain_span(sd)) |
4a6cc4bd | 1613 | update_group_shares_cpu(tg, i, shares, rq_weight, usd_rq_weight); |
34d76c41 PZ |
1614 | |
1615 | local_irq_restore(flags); | |
eb755805 PZ |
1616 | |
1617 | return 0; | |
c09595f6 PZ |
1618 | } |
1619 | ||
1620 | /* | |
c8cba857 PZ |
1621 | * Compute the cpu's hierarchical load factor for each task group. |
1622 | * This needs to be done in a top-down fashion because the load of a child | |
1623 | * group is a fraction of its parents load. | |
c09595f6 | 1624 | */ |
eb755805 | 1625 | static int tg_load_down(struct task_group *tg, void *data) |
c09595f6 | 1626 | { |
c8cba857 | 1627 | unsigned long load; |
eb755805 | 1628 | long cpu = (long)data; |
c09595f6 | 1629 | |
c8cba857 PZ |
1630 | if (!tg->parent) { |
1631 | load = cpu_rq(cpu)->load.weight; | |
1632 | } else { | |
1633 | load = tg->parent->cfs_rq[cpu]->h_load; | |
1634 | load *= tg->cfs_rq[cpu]->shares; | |
1635 | load /= tg->parent->cfs_rq[cpu]->load.weight + 1; | |
1636 | } | |
c09595f6 | 1637 | |
c8cba857 | 1638 | tg->cfs_rq[cpu]->h_load = load; |
c09595f6 | 1639 | |
eb755805 | 1640 | return 0; |
c09595f6 PZ |
1641 | } |
1642 | ||
c8cba857 | 1643 | static void update_shares(struct sched_domain *sd) |
4d8d595d | 1644 | { |
e7097159 PZ |
1645 | s64 elapsed; |
1646 | u64 now; | |
1647 | ||
1648 | if (root_task_group_empty()) | |
1649 | return; | |
1650 | ||
1651 | now = cpu_clock(raw_smp_processor_id()); | |
1652 | elapsed = now - sd->last_update; | |
2398f2c6 PZ |
1653 | |
1654 | if (elapsed >= (s64)(u64)sysctl_sched_shares_ratelimit) { | |
1655 | sd->last_update = now; | |
eb755805 | 1656 | walk_tg_tree(tg_nop, tg_shares_up, sd); |
2398f2c6 | 1657 | } |
4d8d595d PZ |
1658 | } |
1659 | ||
eb755805 | 1660 | static void update_h_load(long cpu) |
c09595f6 | 1661 | { |
e7097159 PZ |
1662 | if (root_task_group_empty()) |
1663 | return; | |
1664 | ||
eb755805 | 1665 | walk_tg_tree(tg_load_down, tg_nop, (void *)cpu); |
c09595f6 PZ |
1666 | } |
1667 | ||
c09595f6 PZ |
1668 | #else |
1669 | ||
c8cba857 | 1670 | static inline void update_shares(struct sched_domain *sd) |
4d8d595d PZ |
1671 | { |
1672 | } | |
1673 | ||
18d95a28 PZ |
1674 | #endif |
1675 | ||
8f45e2b5 GH |
1676 | #ifdef CONFIG_PREEMPT |
1677 | ||
b78bb868 PZ |
1678 | static void double_rq_lock(struct rq *rq1, struct rq *rq2); |
1679 | ||
70574a99 | 1680 | /* |
8f45e2b5 GH |
1681 | * fair double_lock_balance: Safely acquires both rq->locks in a fair |
1682 | * way at the expense of forcing extra atomic operations in all | |
1683 | * invocations. This assures that the double_lock is acquired using the | |
1684 | * same underlying policy as the spinlock_t on this architecture, which | |
1685 | * reduces latency compared to the unfair variant below. However, it | |
1686 | * also adds more overhead and therefore may reduce throughput. | |
70574a99 | 1687 | */ |
8f45e2b5 GH |
1688 | static inline int _double_lock_balance(struct rq *this_rq, struct rq *busiest) |
1689 | __releases(this_rq->lock) | |
1690 | __acquires(busiest->lock) | |
1691 | __acquires(this_rq->lock) | |
1692 | { | |
05fa785c | 1693 | raw_spin_unlock(&this_rq->lock); |
8f45e2b5 GH |
1694 | double_rq_lock(this_rq, busiest); |
1695 | ||
1696 | return 1; | |
1697 | } | |
1698 | ||
1699 | #else | |
1700 | /* | |
1701 | * Unfair double_lock_balance: Optimizes throughput at the expense of | |
1702 | * latency by eliminating extra atomic operations when the locks are | |
1703 | * already in proper order on entry. This favors lower cpu-ids and will | |
1704 | * grant the double lock to lower cpus over higher ids under contention, | |
1705 | * regardless of entry order into the function. | |
1706 | */ | |
1707 | static int _double_lock_balance(struct rq *this_rq, struct rq *busiest) | |
70574a99 AD |
1708 | __releases(this_rq->lock) |
1709 | __acquires(busiest->lock) | |
1710 | __acquires(this_rq->lock) | |
1711 | { | |
1712 | int ret = 0; | |
1713 | ||
05fa785c | 1714 | if (unlikely(!raw_spin_trylock(&busiest->lock))) { |
70574a99 | 1715 | if (busiest < this_rq) { |
05fa785c TG |
1716 | raw_spin_unlock(&this_rq->lock); |
1717 | raw_spin_lock(&busiest->lock); | |
1718 | raw_spin_lock_nested(&this_rq->lock, | |
1719 | SINGLE_DEPTH_NESTING); | |
70574a99 AD |
1720 | ret = 1; |
1721 | } else | |
05fa785c TG |
1722 | raw_spin_lock_nested(&busiest->lock, |
1723 | SINGLE_DEPTH_NESTING); | |
70574a99 AD |
1724 | } |
1725 | return ret; | |
1726 | } | |
1727 | ||
8f45e2b5 GH |
1728 | #endif /* CONFIG_PREEMPT */ |
1729 | ||
1730 | /* | |
1731 | * double_lock_balance - lock the busiest runqueue, this_rq is locked already. | |
1732 | */ | |
1733 | static int double_lock_balance(struct rq *this_rq, struct rq *busiest) | |
1734 | { | |
1735 | if (unlikely(!irqs_disabled())) { | |
1736 | /* printk() doesn't work good under rq->lock */ | |
05fa785c | 1737 | raw_spin_unlock(&this_rq->lock); |
8f45e2b5 GH |
1738 | BUG_ON(1); |
1739 | } | |
1740 | ||
1741 | return _double_lock_balance(this_rq, busiest); | |
1742 | } | |
1743 | ||
70574a99 AD |
1744 | static inline void double_unlock_balance(struct rq *this_rq, struct rq *busiest) |
1745 | __releases(busiest->lock) | |
1746 | { | |
05fa785c | 1747 | raw_spin_unlock(&busiest->lock); |
70574a99 AD |
1748 | lock_set_subclass(&this_rq->lock.dep_map, 0, _RET_IP_); |
1749 | } | |
1e3c88bd PZ |
1750 | |
1751 | /* | |
1752 | * double_rq_lock - safely lock two runqueues | |
1753 | * | |
1754 | * Note this does not disable interrupts like task_rq_lock, | |
1755 | * you need to do so manually before calling. | |
1756 | */ | |
1757 | static void double_rq_lock(struct rq *rq1, struct rq *rq2) | |
1758 | __acquires(rq1->lock) | |
1759 | __acquires(rq2->lock) | |
1760 | { | |
1761 | BUG_ON(!irqs_disabled()); | |
1762 | if (rq1 == rq2) { | |
1763 | raw_spin_lock(&rq1->lock); | |
1764 | __acquire(rq2->lock); /* Fake it out ;) */ | |
1765 | } else { | |
1766 | if (rq1 < rq2) { | |
1767 | raw_spin_lock(&rq1->lock); | |
1768 | raw_spin_lock_nested(&rq2->lock, SINGLE_DEPTH_NESTING); | |
1769 | } else { | |
1770 | raw_spin_lock(&rq2->lock); | |
1771 | raw_spin_lock_nested(&rq1->lock, SINGLE_DEPTH_NESTING); | |
1772 | } | |
1773 | } | |
1774 | update_rq_clock(rq1); | |
1775 | update_rq_clock(rq2); | |
1776 | } | |
1777 | ||
1778 | /* | |
1779 | * double_rq_unlock - safely unlock two runqueues | |
1780 | * | |
1781 | * Note this does not restore interrupts like task_rq_unlock, | |
1782 | * you need to do so manually after calling. | |
1783 | */ | |
1784 | static void double_rq_unlock(struct rq *rq1, struct rq *rq2) | |
1785 | __releases(rq1->lock) | |
1786 | __releases(rq2->lock) | |
1787 | { | |
1788 | raw_spin_unlock(&rq1->lock); | |
1789 | if (rq1 != rq2) | |
1790 | raw_spin_unlock(&rq2->lock); | |
1791 | else | |
1792 | __release(rq2->lock); | |
1793 | } | |
1794 | ||
18d95a28 PZ |
1795 | #endif |
1796 | ||
30432094 | 1797 | #ifdef CONFIG_FAIR_GROUP_SCHED |
34e83e85 IM |
1798 | static void cfs_rq_set_shares(struct cfs_rq *cfs_rq, unsigned long shares) |
1799 | { | |
30432094 | 1800 | #ifdef CONFIG_SMP |
34e83e85 IM |
1801 | cfs_rq->shares = shares; |
1802 | #endif | |
1803 | } | |
30432094 | 1804 | #endif |
e7693a36 | 1805 | |
dce48a84 | 1806 | static void calc_load_account_active(struct rq *this_rq); |
0bcdcf28 | 1807 | static void update_sysctl(void); |
acb4a848 | 1808 | static int get_update_sysctl_factor(void); |
dce48a84 | 1809 | |
cd29fe6f PZ |
1810 | static inline void __set_task_cpu(struct task_struct *p, unsigned int cpu) |
1811 | { | |
1812 | set_task_rq(p, cpu); | |
1813 | #ifdef CONFIG_SMP | |
1814 | /* | |
1815 | * After ->cpu is set up to a new value, task_rq_lock(p, ...) can be | |
1816 | * successfuly executed on another CPU. We must ensure that updates of | |
1817 | * per-task data have been completed by this moment. | |
1818 | */ | |
1819 | smp_wmb(); | |
1820 | task_thread_info(p)->cpu = cpu; | |
1821 | #endif | |
1822 | } | |
dce48a84 | 1823 | |
1e3c88bd | 1824 | static const struct sched_class rt_sched_class; |
dd41f596 IM |
1825 | |
1826 | #define sched_class_highest (&rt_sched_class) | |
1f11eb6a GH |
1827 | #define for_each_class(class) \ |
1828 | for (class = sched_class_highest; class; class = class->next) | |
dd41f596 | 1829 | |
1e3c88bd PZ |
1830 | #include "sched_stats.h" |
1831 | ||
c09595f6 | 1832 | static void inc_nr_running(struct rq *rq) |
9c217245 IM |
1833 | { |
1834 | rq->nr_running++; | |
9c217245 IM |
1835 | } |
1836 | ||
c09595f6 | 1837 | static void dec_nr_running(struct rq *rq) |
9c217245 IM |
1838 | { |
1839 | rq->nr_running--; | |
9c217245 IM |
1840 | } |
1841 | ||
45bf76df IM |
1842 | static void set_load_weight(struct task_struct *p) |
1843 | { | |
1844 | if (task_has_rt_policy(p)) { | |
dd41f596 IM |
1845 | p->se.load.weight = prio_to_weight[0] * 2; |
1846 | p->se.load.inv_weight = prio_to_wmult[0] >> 1; | |
1847 | return; | |
1848 | } | |
45bf76df | 1849 | |
dd41f596 IM |
1850 | /* |
1851 | * SCHED_IDLE tasks get minimal weight: | |
1852 | */ | |
1853 | if (p->policy == SCHED_IDLE) { | |
1854 | p->se.load.weight = WEIGHT_IDLEPRIO; | |
1855 | p->se.load.inv_weight = WMULT_IDLEPRIO; | |
1856 | return; | |
1857 | } | |
71f8bd46 | 1858 | |
dd41f596 IM |
1859 | p->se.load.weight = prio_to_weight[p->static_prio - MAX_RT_PRIO]; |
1860 | p->se.load.inv_weight = prio_to_wmult[p->static_prio - MAX_RT_PRIO]; | |
71f8bd46 IM |
1861 | } |
1862 | ||
2087a1ad GH |
1863 | static void update_avg(u64 *avg, u64 sample) |
1864 | { | |
1865 | s64 diff = sample - *avg; | |
1866 | *avg += diff >> 3; | |
1867 | } | |
1868 | ||
ea87bb78 TG |
1869 | static void |
1870 | enqueue_task(struct rq *rq, struct task_struct *p, int wakeup, bool head) | |
71f8bd46 | 1871 | { |
831451ac PZ |
1872 | if (wakeup) |
1873 | p->se.start_runtime = p->se.sum_exec_runtime; | |
1874 | ||
dd41f596 | 1875 | sched_info_queued(p); |
ea87bb78 | 1876 | p->sched_class->enqueue_task(rq, p, wakeup, head); |
dd41f596 | 1877 | p->se.on_rq = 1; |
71f8bd46 IM |
1878 | } |
1879 | ||
69be72c1 | 1880 | static void dequeue_task(struct rq *rq, struct task_struct *p, int sleep) |
71f8bd46 | 1881 | { |
831451ac PZ |
1882 | if (sleep) { |
1883 | if (p->se.last_wakeup) { | |
1884 | update_avg(&p->se.avg_overlap, | |
1885 | p->se.sum_exec_runtime - p->se.last_wakeup); | |
1886 | p->se.last_wakeup = 0; | |
1887 | } else { | |
1888 | update_avg(&p->se.avg_wakeup, | |
1889 | sysctl_sched_wakeup_granularity); | |
1890 | } | |
2087a1ad GH |
1891 | } |
1892 | ||
46ac22ba | 1893 | sched_info_dequeued(p); |
f02231e5 | 1894 | p->sched_class->dequeue_task(rq, p, sleep); |
dd41f596 | 1895 | p->se.on_rq = 0; |
71f8bd46 IM |
1896 | } |
1897 | ||
1e3c88bd PZ |
1898 | /* |
1899 | * activate_task - move a task to the runqueue. | |
1900 | */ | |
1901 | static void activate_task(struct rq *rq, struct task_struct *p, int wakeup) | |
1902 | { | |
1903 | if (task_contributes_to_load(p)) | |
1904 | rq->nr_uninterruptible--; | |
1905 | ||
ea87bb78 | 1906 | enqueue_task(rq, p, wakeup, false); |
1e3c88bd PZ |
1907 | inc_nr_running(rq); |
1908 | } | |
1909 | ||
1910 | /* | |
1911 | * deactivate_task - remove a task from the runqueue. | |
1912 | */ | |
1913 | static void deactivate_task(struct rq *rq, struct task_struct *p, int sleep) | |
1914 | { | |
1915 | if (task_contributes_to_load(p)) | |
1916 | rq->nr_uninterruptible++; | |
1917 | ||
1918 | dequeue_task(rq, p, sleep); | |
1919 | dec_nr_running(rq); | |
1920 | } | |
1921 | ||
1922 | #include "sched_idletask.c" | |
1923 | #include "sched_fair.c" | |
1924 | #include "sched_rt.c" | |
1925 | #ifdef CONFIG_SCHED_DEBUG | |
1926 | # include "sched_debug.c" | |
1927 | #endif | |
1928 | ||
14531189 | 1929 | /* |
dd41f596 | 1930 | * __normal_prio - return the priority that is based on the static prio |
14531189 | 1931 | */ |
14531189 IM |
1932 | static inline int __normal_prio(struct task_struct *p) |
1933 | { | |
dd41f596 | 1934 | return p->static_prio; |
14531189 IM |
1935 | } |
1936 | ||
b29739f9 IM |
1937 | /* |
1938 | * Calculate the expected normal priority: i.e. priority | |
1939 | * without taking RT-inheritance into account. Might be | |
1940 | * boosted by interactivity modifiers. Changes upon fork, | |
1941 | * setprio syscalls, and whenever the interactivity | |
1942 | * estimator recalculates. | |
1943 | */ | |
36c8b586 | 1944 | static inline int normal_prio(struct task_struct *p) |
b29739f9 IM |
1945 | { |
1946 | int prio; | |
1947 | ||
e05606d3 | 1948 | if (task_has_rt_policy(p)) |
b29739f9 IM |
1949 | prio = MAX_RT_PRIO-1 - p->rt_priority; |
1950 | else | |
1951 | prio = __normal_prio(p); | |
1952 | return prio; | |
1953 | } | |
1954 | ||
1955 | /* | |
1956 | * Calculate the current priority, i.e. the priority | |
1957 | * taken into account by the scheduler. This value might | |
1958 | * be boosted by RT tasks, or might be boosted by | |
1959 | * interactivity modifiers. Will be RT if the task got | |
1960 | * RT-boosted. If not then it returns p->normal_prio. | |
1961 | */ | |
36c8b586 | 1962 | static int effective_prio(struct task_struct *p) |
b29739f9 IM |
1963 | { |
1964 | p->normal_prio = normal_prio(p); | |
1965 | /* | |
1966 | * If we are RT tasks or we were boosted to RT priority, | |
1967 | * keep the priority unchanged. Otherwise, update priority | |
1968 | * to the normal priority: | |
1969 | */ | |
1970 | if (!rt_prio(p->prio)) | |
1971 | return p->normal_prio; | |
1972 | return p->prio; | |
1973 | } | |
1974 | ||
1da177e4 LT |
1975 | /** |
1976 | * task_curr - is this task currently executing on a CPU? | |
1977 | * @p: the task in question. | |
1978 | */ | |
36c8b586 | 1979 | inline int task_curr(const struct task_struct *p) |
1da177e4 LT |
1980 | { |
1981 | return cpu_curr(task_cpu(p)) == p; | |
1982 | } | |
1983 | ||
cb469845 SR |
1984 | static inline void check_class_changed(struct rq *rq, struct task_struct *p, |
1985 | const struct sched_class *prev_class, | |
1986 | int oldprio, int running) | |
1987 | { | |
1988 | if (prev_class != p->sched_class) { | |
1989 | if (prev_class->switched_from) | |
1990 | prev_class->switched_from(rq, p, running); | |
1991 | p->sched_class->switched_to(rq, p, running); | |
1992 | } else | |
1993 | p->sched_class->prio_changed(rq, p, oldprio, running); | |
1994 | } | |
1995 | ||
1da177e4 | 1996 | #ifdef CONFIG_SMP |
cc367732 IM |
1997 | /* |
1998 | * Is this task likely cache-hot: | |
1999 | */ | |
e7693a36 | 2000 | static int |
cc367732 IM |
2001 | task_hot(struct task_struct *p, u64 now, struct sched_domain *sd) |
2002 | { | |
2003 | s64 delta; | |
2004 | ||
e6c8fba7 PZ |
2005 | if (p->sched_class != &fair_sched_class) |
2006 | return 0; | |
2007 | ||
f540a608 IM |
2008 | /* |
2009 | * Buddy candidates are cache hot: | |
2010 | */ | |
f685ceac | 2011 | if (sched_feat(CACHE_HOT_BUDDY) && this_rq()->nr_running && |
4793241b PZ |
2012 | (&p->se == cfs_rq_of(&p->se)->next || |
2013 | &p->se == cfs_rq_of(&p->se)->last)) | |
f540a608 IM |
2014 | return 1; |
2015 | ||
6bc1665b IM |
2016 | if (sysctl_sched_migration_cost == -1) |
2017 | return 1; | |
2018 | if (sysctl_sched_migration_cost == 0) | |
2019 | return 0; | |
2020 | ||
cc367732 IM |
2021 | delta = now - p->se.exec_start; |
2022 | ||
2023 | return delta < (s64)sysctl_sched_migration_cost; | |
2024 | } | |
2025 | ||
dd41f596 | 2026 | void set_task_cpu(struct task_struct *p, unsigned int new_cpu) |
c65cc870 | 2027 | { |
e2912009 PZ |
2028 | #ifdef CONFIG_SCHED_DEBUG |
2029 | /* | |
2030 | * We should never call set_task_cpu() on a blocked task, | |
2031 | * ttwu() will sort out the placement. | |
2032 | */ | |
077614ee PZ |
2033 | WARN_ON_ONCE(p->state != TASK_RUNNING && p->state != TASK_WAKING && |
2034 | !(task_thread_info(p)->preempt_count & PREEMPT_ACTIVE)); | |
e2912009 PZ |
2035 | #endif |
2036 | ||
de1d7286 | 2037 | trace_sched_migrate_task(p, new_cpu); |
cbc34ed1 | 2038 | |
0c69774e PZ |
2039 | if (task_cpu(p) != new_cpu) { |
2040 | p->se.nr_migrations++; | |
2041 | perf_sw_event(PERF_COUNT_SW_CPU_MIGRATIONS, 1, 1, NULL, 0); | |
2042 | } | |
dd41f596 IM |
2043 | |
2044 | __set_task_cpu(p, new_cpu); | |
c65cc870 IM |
2045 | } |
2046 | ||
70b97a7f | 2047 | struct migration_req { |
1da177e4 | 2048 | struct list_head list; |
1da177e4 | 2049 | |
36c8b586 | 2050 | struct task_struct *task; |
1da177e4 LT |
2051 | int dest_cpu; |
2052 | ||
1da177e4 | 2053 | struct completion done; |
70b97a7f | 2054 | }; |
1da177e4 LT |
2055 | |
2056 | /* | |
2057 | * The task's runqueue lock must be held. | |
2058 | * Returns true if you have to wait for migration thread. | |
2059 | */ | |
36c8b586 | 2060 | static int |
70b97a7f | 2061 | migrate_task(struct task_struct *p, int dest_cpu, struct migration_req *req) |
1da177e4 | 2062 | { |
70b97a7f | 2063 | struct rq *rq = task_rq(p); |
1da177e4 LT |
2064 | |
2065 | /* | |
2066 | * If the task is not on a runqueue (and not running), then | |
e2912009 | 2067 | * the next wake-up will properly place the task. |
1da177e4 | 2068 | */ |
e2912009 | 2069 | if (!p->se.on_rq && !task_running(rq, p)) |
1da177e4 | 2070 | return 0; |
1da177e4 LT |
2071 | |
2072 | init_completion(&req->done); | |
1da177e4 LT |
2073 | req->task = p; |
2074 | req->dest_cpu = dest_cpu; | |
2075 | list_add(&req->list, &rq->migration_queue); | |
48f24c4d | 2076 | |
1da177e4 LT |
2077 | return 1; |
2078 | } | |
2079 | ||
a26b89f0 MM |
2080 | /* |
2081 | * wait_task_context_switch - wait for a thread to complete at least one | |
2082 | * context switch. | |
2083 | * | |
2084 | * @p must not be current. | |
2085 | */ | |
2086 | void wait_task_context_switch(struct task_struct *p) | |
2087 | { | |
2088 | unsigned long nvcsw, nivcsw, flags; | |
2089 | int running; | |
2090 | struct rq *rq; | |
2091 | ||
2092 | nvcsw = p->nvcsw; | |
2093 | nivcsw = p->nivcsw; | |
2094 | for (;;) { | |
2095 | /* | |
2096 | * The runqueue is assigned before the actual context | |
2097 | * switch. We need to take the runqueue lock. | |
2098 | * | |
2099 | * We could check initially without the lock but it is | |
2100 | * very likely that we need to take the lock in every | |
2101 | * iteration. | |
2102 | */ | |
2103 | rq = task_rq_lock(p, &flags); | |
2104 | running = task_running(rq, p); | |
2105 | task_rq_unlock(rq, &flags); | |
2106 | ||
2107 | if (likely(!running)) | |
2108 | break; | |
2109 | /* | |
2110 | * The switch count is incremented before the actual | |
2111 | * context switch. We thus wait for two switches to be | |
2112 | * sure at least one completed. | |
2113 | */ | |
2114 | if ((p->nvcsw - nvcsw) > 1) | |
2115 | break; | |
2116 | if ((p->nivcsw - nivcsw) > 1) | |
2117 | break; | |
2118 | ||
2119 | cpu_relax(); | |
2120 | } | |
2121 | } | |
2122 | ||
1da177e4 LT |
2123 | /* |
2124 | * wait_task_inactive - wait for a thread to unschedule. | |
2125 | * | |
85ba2d86 RM |
2126 | * If @match_state is nonzero, it's the @p->state value just checked and |
2127 | * not expected to change. If it changes, i.e. @p might have woken up, | |
2128 | * then return zero. When we succeed in waiting for @p to be off its CPU, | |
2129 | * we return a positive number (its total switch count). If a second call | |
2130 | * a short while later returns the same number, the caller can be sure that | |
2131 | * @p has remained unscheduled the whole time. | |
2132 | * | |
1da177e4 LT |
2133 | * The caller must ensure that the task *will* unschedule sometime soon, |
2134 | * else this function might spin for a *long* time. This function can't | |
2135 | * be called with interrupts off, or it may introduce deadlock with | |
2136 | * smp_call_function() if an IPI is sent by the same process we are | |
2137 | * waiting to become inactive. | |
2138 | */ | |
85ba2d86 | 2139 | unsigned long wait_task_inactive(struct task_struct *p, long match_state) |
1da177e4 LT |
2140 | { |
2141 | unsigned long flags; | |
dd41f596 | 2142 | int running, on_rq; |
85ba2d86 | 2143 | unsigned long ncsw; |
70b97a7f | 2144 | struct rq *rq; |
1da177e4 | 2145 | |
3a5c359a AK |
2146 | for (;;) { |
2147 | /* | |
2148 | * We do the initial early heuristics without holding | |
2149 | * any task-queue locks at all. We'll only try to get | |
2150 | * the runqueue lock when things look like they will | |
2151 | * work out! | |
2152 | */ | |
2153 | rq = task_rq(p); | |
fa490cfd | 2154 | |
3a5c359a AK |
2155 | /* |
2156 | * If the task is actively running on another CPU | |
2157 | * still, just relax and busy-wait without holding | |
2158 | * any locks. | |
2159 | * | |
2160 | * NOTE! Since we don't hold any locks, it's not | |
2161 | * even sure that "rq" stays as the right runqueue! | |
2162 | * But we don't care, since "task_running()" will | |
2163 | * return false if the runqueue has changed and p | |
2164 | * is actually now running somewhere else! | |
2165 | */ | |
85ba2d86 RM |
2166 | while (task_running(rq, p)) { |
2167 | if (match_state && unlikely(p->state != match_state)) | |
2168 | return 0; | |
3a5c359a | 2169 | cpu_relax(); |
85ba2d86 | 2170 | } |
fa490cfd | 2171 | |
3a5c359a AK |
2172 | /* |
2173 | * Ok, time to look more closely! We need the rq | |
2174 | * lock now, to be *sure*. If we're wrong, we'll | |
2175 | * just go back and repeat. | |
2176 | */ | |
2177 | rq = task_rq_lock(p, &flags); | |
0a16b607 | 2178 | trace_sched_wait_task(rq, p); |
3a5c359a AK |
2179 | running = task_running(rq, p); |
2180 | on_rq = p->se.on_rq; | |
85ba2d86 | 2181 | ncsw = 0; |
f31e11d8 | 2182 | if (!match_state || p->state == match_state) |
93dcf55f | 2183 | ncsw = p->nvcsw | LONG_MIN; /* sets MSB */ |
3a5c359a | 2184 | task_rq_unlock(rq, &flags); |
fa490cfd | 2185 | |
85ba2d86 RM |
2186 | /* |
2187 | * If it changed from the expected state, bail out now. | |
2188 | */ | |
2189 | if (unlikely(!ncsw)) | |
2190 | break; | |
2191 | ||
3a5c359a AK |
2192 | /* |
2193 | * Was it really running after all now that we | |
2194 | * checked with the proper locks actually held? | |
2195 | * | |
2196 | * Oops. Go back and try again.. | |
2197 | */ | |
2198 | if (unlikely(running)) { | |
2199 | cpu_relax(); | |
2200 | continue; | |
2201 | } | |
fa490cfd | 2202 | |
3a5c359a AK |
2203 | /* |
2204 | * It's not enough that it's not actively running, | |
2205 | * it must be off the runqueue _entirely_, and not | |
2206 | * preempted! | |
2207 | * | |
80dd99b3 | 2208 | * So if it was still runnable (but just not actively |
3a5c359a AK |
2209 | * running right now), it's preempted, and we should |
2210 | * yield - it could be a while. | |
2211 | */ | |
2212 | if (unlikely(on_rq)) { | |
2213 | schedule_timeout_uninterruptible(1); | |
2214 | continue; | |
2215 | } | |
fa490cfd | 2216 | |
3a5c359a AK |
2217 | /* |
2218 | * Ahh, all good. It wasn't running, and it wasn't | |
2219 | * runnable, which means that it will never become | |
2220 | * running in the future either. We're all done! | |
2221 | */ | |
2222 | break; | |
2223 | } | |
85ba2d86 RM |
2224 | |
2225 | return ncsw; | |
1da177e4 LT |
2226 | } |
2227 | ||
2228 | /*** | |
2229 | * kick_process - kick a running thread to enter/exit the kernel | |
2230 | * @p: the to-be-kicked thread | |
2231 | * | |
2232 | * Cause a process which is running on another CPU to enter | |
2233 | * kernel-mode, without any delay. (to get signals handled.) | |
2234 | * | |
2235 | * NOTE: this function doesnt have to take the runqueue lock, | |
2236 | * because all it wants to ensure is that the remote task enters | |
2237 | * the kernel. If the IPI races and the task has been migrated | |
2238 | * to another CPU then no harm is done and the purpose has been | |
2239 | * achieved as well. | |
2240 | */ | |
36c8b586 | 2241 | void kick_process(struct task_struct *p) |
1da177e4 LT |
2242 | { |
2243 | int cpu; | |
2244 | ||
2245 | preempt_disable(); | |
2246 | cpu = task_cpu(p); | |
2247 | if ((cpu != smp_processor_id()) && task_curr(p)) | |
2248 | smp_send_reschedule(cpu); | |
2249 | preempt_enable(); | |
2250 | } | |
b43e3521 | 2251 | EXPORT_SYMBOL_GPL(kick_process); |
476d139c | 2252 | #endif /* CONFIG_SMP */ |
1da177e4 | 2253 | |
0793a61d TG |
2254 | /** |
2255 | * task_oncpu_function_call - call a function on the cpu on which a task runs | |
2256 | * @p: the task to evaluate | |
2257 | * @func: the function to be called | |
2258 | * @info: the function call argument | |
2259 | * | |
2260 | * Calls the function @func when the task is currently running. This might | |
2261 | * be on the current CPU, which just calls the function directly | |
2262 | */ | |
2263 | void task_oncpu_function_call(struct task_struct *p, | |
2264 | void (*func) (void *info), void *info) | |
2265 | { | |
2266 | int cpu; | |
2267 | ||
2268 | preempt_disable(); | |
2269 | cpu = task_cpu(p); | |
2270 | if (task_curr(p)) | |
2271 | smp_call_function_single(cpu, func, info, 1); | |
2272 | preempt_enable(); | |
2273 | } | |
2274 | ||
970b13ba | 2275 | #ifdef CONFIG_SMP |
5da9a0fb PZ |
2276 | static int select_fallback_rq(int cpu, struct task_struct *p) |
2277 | { | |
2278 | int dest_cpu; | |
2279 | const struct cpumask *nodemask = cpumask_of_node(cpu_to_node(cpu)); | |
2280 | ||
2281 | /* Look for allowed, online CPU in same node. */ | |
2282 | for_each_cpu_and(dest_cpu, nodemask, cpu_active_mask) | |
2283 | if (cpumask_test_cpu(dest_cpu, &p->cpus_allowed)) | |
2284 | return dest_cpu; | |
2285 | ||
2286 | /* Any allowed, online CPU? */ | |
2287 | dest_cpu = cpumask_any_and(&p->cpus_allowed, cpu_active_mask); | |
2288 | if (dest_cpu < nr_cpu_ids) | |
2289 | return dest_cpu; | |
2290 | ||
2291 | /* No more Mr. Nice Guy. */ | |
2292 | if (dest_cpu >= nr_cpu_ids) { | |
2293 | rcu_read_lock(); | |
2294 | cpuset_cpus_allowed_locked(p, &p->cpus_allowed); | |
2295 | rcu_read_unlock(); | |
2296 | dest_cpu = cpumask_any_and(cpu_active_mask, &p->cpus_allowed); | |
2297 | ||
2298 | /* | |
2299 | * Don't tell them about moving exiting tasks or | |
2300 | * kernel threads (both mm NULL), since they never | |
2301 | * leave kernel. | |
2302 | */ | |
2303 | if (p->mm && printk_ratelimit()) { | |
2304 | printk(KERN_INFO "process %d (%s) no " | |
2305 | "longer affine to cpu%d\n", | |
2306 | task_pid_nr(p), p->comm, cpu); | |
2307 | } | |
2308 | } | |
2309 | ||
2310 | return dest_cpu; | |
2311 | } | |
2312 | ||
e2912009 | 2313 | /* |
fabf318e PZ |
2314 | * Gets called from 3 sites (exec, fork, wakeup), since it is called without |
2315 | * holding rq->lock we need to ensure ->cpus_allowed is stable, this is done | |
2316 | * by: | |
e2912009 | 2317 | * |
fabf318e PZ |
2318 | * exec: is unstable, retry loop |
2319 | * fork & wake-up: serialize ->cpus_allowed against TASK_WAKING | |
e2912009 | 2320 | */ |
970b13ba PZ |
2321 | static inline |
2322 | int select_task_rq(struct task_struct *p, int sd_flags, int wake_flags) | |
2323 | { | |
e2912009 PZ |
2324 | int cpu = p->sched_class->select_task_rq(p, sd_flags, wake_flags); |
2325 | ||
2326 | /* | |
2327 | * In order not to call set_task_cpu() on a blocking task we need | |
2328 | * to rely on ttwu() to place the task on a valid ->cpus_allowed | |
2329 | * cpu. | |
2330 | * | |
2331 | * Since this is common to all placement strategies, this lives here. | |
2332 | * | |
2333 | * [ this allows ->select_task() to simply return task_cpu(p) and | |
2334 | * not worry about this generic constraint ] | |
2335 | */ | |
2336 | if (unlikely(!cpumask_test_cpu(cpu, &p->cpus_allowed) || | |
70f11205 | 2337 | !cpu_online(cpu))) |
5da9a0fb | 2338 | cpu = select_fallback_rq(task_cpu(p), p); |
e2912009 PZ |
2339 | |
2340 | return cpu; | |
970b13ba PZ |
2341 | } |
2342 | #endif | |
2343 | ||
1da177e4 LT |
2344 | /*** |
2345 | * try_to_wake_up - wake up a thread | |
2346 | * @p: the to-be-woken-up thread | |
2347 | * @state: the mask of task states that can be woken | |
2348 | * @sync: do a synchronous wakeup? | |
2349 | * | |
2350 | * Put it on the run-queue if it's not already there. The "current" | |
2351 | * thread is always on the run-queue (except when the actual | |
2352 | * re-schedule is in progress), and as such you're allowed to do | |
2353 | * the simpler "current->state = TASK_RUNNING" to mark yourself | |
2354 | * runnable without the overhead of this. | |
2355 | * | |
2356 | * returns failure only if the task is already active. | |
2357 | */ | |
7d478721 PZ |
2358 | static int try_to_wake_up(struct task_struct *p, unsigned int state, |
2359 | int wake_flags) | |
1da177e4 | 2360 | { |
cc367732 | 2361 | int cpu, orig_cpu, this_cpu, success = 0; |
1da177e4 | 2362 | unsigned long flags; |
ab3b3aa5 | 2363 | struct rq *rq; |
1da177e4 | 2364 | |
b85d0667 | 2365 | if (!sched_feat(SYNC_WAKEUPS)) |
7d478721 | 2366 | wake_flags &= ~WF_SYNC; |
2398f2c6 | 2367 | |
e9c84311 | 2368 | this_cpu = get_cpu(); |
2398f2c6 | 2369 | |
04e2f174 | 2370 | smp_wmb(); |
ab3b3aa5 | 2371 | rq = task_rq_lock(p, &flags); |
03e89e45 | 2372 | update_rq_clock(rq); |
e9c84311 | 2373 | if (!(p->state & state)) |
1da177e4 LT |
2374 | goto out; |
2375 | ||
dd41f596 | 2376 | if (p->se.on_rq) |
1da177e4 LT |
2377 | goto out_running; |
2378 | ||
2379 | cpu = task_cpu(p); | |
cc367732 | 2380 | orig_cpu = cpu; |
1da177e4 LT |
2381 | |
2382 | #ifdef CONFIG_SMP | |
2383 | if (unlikely(task_running(rq, p))) | |
2384 | goto out_activate; | |
2385 | ||
e9c84311 PZ |
2386 | /* |
2387 | * In order to handle concurrent wakeups and release the rq->lock | |
2388 | * we put the task in TASK_WAKING state. | |
eb24073b IM |
2389 | * |
2390 | * First fix up the nr_uninterruptible count: | |
e9c84311 | 2391 | */ |
eb24073b IM |
2392 | if (task_contributes_to_load(p)) |
2393 | rq->nr_uninterruptible--; | |
e9c84311 | 2394 | p->state = TASK_WAKING; |
efbbd05a PZ |
2395 | |
2396 | if (p->sched_class->task_waking) | |
2397 | p->sched_class->task_waking(rq, p); | |
2398 | ||
ab19cb23 | 2399 | __task_rq_unlock(rq); |
e9c84311 | 2400 | |
970b13ba | 2401 | cpu = select_task_rq(p, SD_BALANCE_WAKE, wake_flags); |
0970d299 PZ |
2402 | if (cpu != orig_cpu) { |
2403 | /* | |
2404 | * Since we migrate the task without holding any rq->lock, | |
2405 | * we need to be careful with task_rq_lock(), since that | |
2406 | * might end up locking an invalid rq. | |
2407 | */ | |
5d2f5a61 | 2408 | set_task_cpu(p, cpu); |
0970d299 | 2409 | } |
ab19cb23 | 2410 | |
0970d299 PZ |
2411 | rq = cpu_rq(cpu); |
2412 | raw_spin_lock(&rq->lock); | |
ab19cb23 | 2413 | update_rq_clock(rq); |
f5dc3753 | 2414 | |
0970d299 PZ |
2415 | /* |
2416 | * We migrated the task without holding either rq->lock, however | |
2417 | * since the task is not on the task list itself, nobody else | |
2418 | * will try and migrate the task, hence the rq should match the | |
2419 | * cpu we just moved it to. | |
2420 | */ | |
2421 | WARN_ON(task_cpu(p) != cpu); | |
e9c84311 | 2422 | WARN_ON(p->state != TASK_WAKING); |
1da177e4 | 2423 | |
e7693a36 GH |
2424 | #ifdef CONFIG_SCHEDSTATS |
2425 | schedstat_inc(rq, ttwu_count); | |
2426 | if (cpu == this_cpu) | |
2427 | schedstat_inc(rq, ttwu_local); | |
2428 | else { | |
2429 | struct sched_domain *sd; | |
2430 | for_each_domain(this_cpu, sd) { | |
758b2cdc | 2431 | if (cpumask_test_cpu(cpu, sched_domain_span(sd))) { |
e7693a36 GH |
2432 | schedstat_inc(sd, ttwu_wake_remote); |
2433 | break; | |
2434 | } | |
2435 | } | |
2436 | } | |
6d6bc0ad | 2437 | #endif /* CONFIG_SCHEDSTATS */ |
e7693a36 | 2438 | |
1da177e4 LT |
2439 | out_activate: |
2440 | #endif /* CONFIG_SMP */ | |
cc367732 | 2441 | schedstat_inc(p, se.nr_wakeups); |
7d478721 | 2442 | if (wake_flags & WF_SYNC) |
cc367732 IM |
2443 | schedstat_inc(p, se.nr_wakeups_sync); |
2444 | if (orig_cpu != cpu) | |
2445 | schedstat_inc(p, se.nr_wakeups_migrate); | |
2446 | if (cpu == this_cpu) | |
2447 | schedstat_inc(p, se.nr_wakeups_local); | |
2448 | else | |
2449 | schedstat_inc(p, se.nr_wakeups_remote); | |
dd41f596 | 2450 | activate_task(rq, p, 1); |
1da177e4 LT |
2451 | success = 1; |
2452 | ||
831451ac PZ |
2453 | /* |
2454 | * Only attribute actual wakeups done by this task. | |
2455 | */ | |
2456 | if (!in_interrupt()) { | |
2457 | struct sched_entity *se = ¤t->se; | |
2458 | u64 sample = se->sum_exec_runtime; | |
2459 | ||
2460 | if (se->last_wakeup) | |
2461 | sample -= se->last_wakeup; | |
2462 | else | |
2463 | sample -= se->start_runtime; | |
2464 | update_avg(&se->avg_wakeup, sample); | |
2465 | ||
2466 | se->last_wakeup = se->sum_exec_runtime; | |
2467 | } | |
2468 | ||
1da177e4 | 2469 | out_running: |
468a15bb | 2470 | trace_sched_wakeup(rq, p, success); |
7d478721 | 2471 | check_preempt_curr(rq, p, wake_flags); |
4ae7d5ce | 2472 | |
1da177e4 | 2473 | p->state = TASK_RUNNING; |
9a897c5a | 2474 | #ifdef CONFIG_SMP |
efbbd05a PZ |
2475 | if (p->sched_class->task_woken) |
2476 | p->sched_class->task_woken(rq, p); | |
eae0c9df MG |
2477 | |
2478 | if (unlikely(rq->idle_stamp)) { | |
2479 | u64 delta = rq->clock - rq->idle_stamp; | |
2480 | u64 max = 2*sysctl_sched_migration_cost; | |
2481 | ||
2482 | if (delta > max) | |
2483 | rq->avg_idle = max; | |
2484 | else | |
2485 | update_avg(&rq->avg_idle, delta); | |
2486 | rq->idle_stamp = 0; | |
2487 | } | |
9a897c5a | 2488 | #endif |
1da177e4 LT |
2489 | out: |
2490 | task_rq_unlock(rq, &flags); | |
e9c84311 | 2491 | put_cpu(); |
1da177e4 LT |
2492 | |
2493 | return success; | |
2494 | } | |
2495 | ||
50fa610a DH |
2496 | /** |
2497 | * wake_up_process - Wake up a specific process | |
2498 | * @p: The process to be woken up. | |
2499 | * | |
2500 | * Attempt to wake up the nominated process and move it to the set of runnable | |
2501 | * processes. Returns 1 if the process was woken up, 0 if it was already | |
2502 | * running. | |
2503 | * | |
2504 | * It may be assumed that this function implies a write memory barrier before | |
2505 | * changing the task state if and only if any tasks are woken up. | |
2506 | */ | |
7ad5b3a5 | 2507 | int wake_up_process(struct task_struct *p) |
1da177e4 | 2508 | { |
d9514f6c | 2509 | return try_to_wake_up(p, TASK_ALL, 0); |
1da177e4 | 2510 | } |
1da177e4 LT |
2511 | EXPORT_SYMBOL(wake_up_process); |
2512 | ||
7ad5b3a5 | 2513 | int wake_up_state(struct task_struct *p, unsigned int state) |
1da177e4 LT |
2514 | { |
2515 | return try_to_wake_up(p, state, 0); | |
2516 | } | |
2517 | ||
1da177e4 LT |
2518 | /* |
2519 | * Perform scheduler related setup for a newly forked process p. | |
2520 | * p is forked by current. | |
dd41f596 IM |
2521 | * |
2522 | * __sched_fork() is basic setup used by init_idle() too: | |
2523 | */ | |
2524 | static void __sched_fork(struct task_struct *p) | |
2525 | { | |
dd41f596 IM |
2526 | p->se.exec_start = 0; |
2527 | p->se.sum_exec_runtime = 0; | |
f6cf891c | 2528 | p->se.prev_sum_exec_runtime = 0; |
6c594c21 | 2529 | p->se.nr_migrations = 0; |
4ae7d5ce IM |
2530 | p->se.last_wakeup = 0; |
2531 | p->se.avg_overlap = 0; | |
831451ac PZ |
2532 | p->se.start_runtime = 0; |
2533 | p->se.avg_wakeup = sysctl_sched_wakeup_granularity; | |
6cfb0d5d IM |
2534 | |
2535 | #ifdef CONFIG_SCHEDSTATS | |
7793527b LDM |
2536 | p->se.wait_start = 0; |
2537 | p->se.wait_max = 0; | |
2538 | p->se.wait_count = 0; | |
2539 | p->se.wait_sum = 0; | |
2540 | ||
2541 | p->se.sleep_start = 0; | |
2542 | p->se.sleep_max = 0; | |
2543 | p->se.sum_sleep_runtime = 0; | |
2544 | ||
2545 | p->se.block_start = 0; | |
2546 | p->se.block_max = 0; | |
2547 | p->se.exec_max = 0; | |
2548 | p->se.slice_max = 0; | |
2549 | ||
2550 | p->se.nr_migrations_cold = 0; | |
2551 | p->se.nr_failed_migrations_affine = 0; | |
2552 | p->se.nr_failed_migrations_running = 0; | |
2553 | p->se.nr_failed_migrations_hot = 0; | |
2554 | p->se.nr_forced_migrations = 0; | |
7793527b LDM |
2555 | |
2556 | p->se.nr_wakeups = 0; | |
2557 | p->se.nr_wakeups_sync = 0; | |
2558 | p->se.nr_wakeups_migrate = 0; | |
2559 | p->se.nr_wakeups_local = 0; | |
2560 | p->se.nr_wakeups_remote = 0; | |
2561 | p->se.nr_wakeups_affine = 0; | |
2562 | p->se.nr_wakeups_affine_attempts = 0; | |
2563 | p->se.nr_wakeups_passive = 0; | |
2564 | p->se.nr_wakeups_idle = 0; | |
2565 | ||
6cfb0d5d | 2566 | #endif |
476d139c | 2567 | |
fa717060 | 2568 | INIT_LIST_HEAD(&p->rt.run_list); |
dd41f596 | 2569 | p->se.on_rq = 0; |
4a55bd5e | 2570 | INIT_LIST_HEAD(&p->se.group_node); |
476d139c | 2571 | |
e107be36 AK |
2572 | #ifdef CONFIG_PREEMPT_NOTIFIERS |
2573 | INIT_HLIST_HEAD(&p->preempt_notifiers); | |
2574 | #endif | |
dd41f596 IM |
2575 | } |
2576 | ||
2577 | /* | |
2578 | * fork()/clone()-time setup: | |
2579 | */ | |
2580 | void sched_fork(struct task_struct *p, int clone_flags) | |
2581 | { | |
2582 | int cpu = get_cpu(); | |
2583 | ||
2584 | __sched_fork(p); | |
06b83b5f PZ |
2585 | /* |
2586 | * We mark the process as waking here. This guarantees that | |
2587 | * nobody will actually run it, and a signal or other external | |
2588 | * event cannot wake it up and insert it on the runqueue either. | |
2589 | */ | |
2590 | p->state = TASK_WAKING; | |
dd41f596 | 2591 | |
b9dc29e7 MG |
2592 | /* |
2593 | * Revert to default priority/policy on fork if requested. | |
2594 | */ | |
2595 | if (unlikely(p->sched_reset_on_fork)) { | |
f83f9ac2 | 2596 | if (p->policy == SCHED_FIFO || p->policy == SCHED_RR) { |
b9dc29e7 | 2597 | p->policy = SCHED_NORMAL; |
f83f9ac2 PW |
2598 | p->normal_prio = p->static_prio; |
2599 | } | |
b9dc29e7 | 2600 | |
6c697bdf MG |
2601 | if (PRIO_TO_NICE(p->static_prio) < 0) { |
2602 | p->static_prio = NICE_TO_PRIO(0); | |
f83f9ac2 | 2603 | p->normal_prio = p->static_prio; |
6c697bdf MG |
2604 | set_load_weight(p); |
2605 | } | |
2606 | ||
b9dc29e7 MG |
2607 | /* |
2608 | * We don't need the reset flag anymore after the fork. It has | |
2609 | * fulfilled its duty: | |
2610 | */ | |
2611 | p->sched_reset_on_fork = 0; | |
2612 | } | |
ca94c442 | 2613 | |
f83f9ac2 PW |
2614 | /* |
2615 | * Make sure we do not leak PI boosting priority to the child. | |
2616 | */ | |
2617 | p->prio = current->normal_prio; | |
2618 | ||
2ddbf952 HS |
2619 | if (!rt_prio(p->prio)) |
2620 | p->sched_class = &fair_sched_class; | |
b29739f9 | 2621 | |
cd29fe6f PZ |
2622 | if (p->sched_class->task_fork) |
2623 | p->sched_class->task_fork(p); | |
2624 | ||
5f3edc1b PZ |
2625 | set_task_cpu(p, cpu); |
2626 | ||
52f17b6c | 2627 | #if defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT) |
dd41f596 | 2628 | if (likely(sched_info_on())) |
52f17b6c | 2629 | memset(&p->sched_info, 0, sizeof(p->sched_info)); |
1da177e4 | 2630 | #endif |
d6077cb8 | 2631 | #if defined(CONFIG_SMP) && defined(__ARCH_WANT_UNLOCKED_CTXSW) |
4866cde0 NP |
2632 | p->oncpu = 0; |
2633 | #endif | |
1da177e4 | 2634 | #ifdef CONFIG_PREEMPT |
4866cde0 | 2635 | /* Want to start with kernel preemption disabled. */ |
a1261f54 | 2636 | task_thread_info(p)->preempt_count = 1; |
1da177e4 | 2637 | #endif |
917b627d GH |
2638 | plist_node_init(&p->pushable_tasks, MAX_PRIO); |
2639 | ||
476d139c | 2640 | put_cpu(); |
1da177e4 LT |
2641 | } |
2642 | ||
2643 | /* | |
2644 | * wake_up_new_task - wake up a newly created task for the first time. | |
2645 | * | |
2646 | * This function will do some initial scheduler statistics housekeeping | |
2647 | * that must be done for every newly created context, then puts the task | |
2648 | * on the runqueue and wakes it. | |
2649 | */ | |
7ad5b3a5 | 2650 | void wake_up_new_task(struct task_struct *p, unsigned long clone_flags) |
1da177e4 LT |
2651 | { |
2652 | unsigned long flags; | |
dd41f596 | 2653 | struct rq *rq; |
c890692b | 2654 | int cpu __maybe_unused = get_cpu(); |
fabf318e PZ |
2655 | |
2656 | #ifdef CONFIG_SMP | |
2657 | /* | |
2658 | * Fork balancing, do it here and not earlier because: | |
2659 | * - cpus_allowed can change in the fork path | |
2660 | * - any previously selected cpu might disappear through hotplug | |
2661 | * | |
2662 | * We still have TASK_WAKING but PF_STARTING is gone now, meaning | |
2663 | * ->cpus_allowed is stable, we have preemption disabled, meaning | |
2664 | * cpu_online_mask is stable. | |
2665 | */ | |
2666 | cpu = select_task_rq(p, SD_BALANCE_FORK, 0); | |
2667 | set_task_cpu(p, cpu); | |
2668 | #endif | |
1da177e4 | 2669 | |
0970d299 PZ |
2670 | /* |
2671 | * Since the task is not on the rq and we still have TASK_WAKING set | |
2672 | * nobody else will migrate this task. | |
2673 | */ | |
2674 | rq = cpu_rq(cpu); | |
2675 | raw_spin_lock_irqsave(&rq->lock, flags); | |
2676 | ||
06b83b5f PZ |
2677 | BUG_ON(p->state != TASK_WAKING); |
2678 | p->state = TASK_RUNNING; | |
a8e504d2 | 2679 | update_rq_clock(rq); |
cd29fe6f | 2680 | activate_task(rq, p, 0); |
c71dd42d | 2681 | trace_sched_wakeup_new(rq, p, 1); |
a7558e01 | 2682 | check_preempt_curr(rq, p, WF_FORK); |
9a897c5a | 2683 | #ifdef CONFIG_SMP |
efbbd05a PZ |
2684 | if (p->sched_class->task_woken) |
2685 | p->sched_class->task_woken(rq, p); | |
9a897c5a | 2686 | #endif |
dd41f596 | 2687 | task_rq_unlock(rq, &flags); |
fabf318e | 2688 | put_cpu(); |
1da177e4 LT |
2689 | } |
2690 | ||
e107be36 AK |
2691 | #ifdef CONFIG_PREEMPT_NOTIFIERS |
2692 | ||
2693 | /** | |
80dd99b3 | 2694 | * preempt_notifier_register - tell me when current is being preempted & rescheduled |
421cee29 | 2695 | * @notifier: notifier struct to register |
e107be36 AK |
2696 | */ |
2697 | void preempt_notifier_register(struct preempt_notifier *notifier) | |
2698 | { | |
2699 | hlist_add_head(¬ifier->link, ¤t->preempt_notifiers); | |
2700 | } | |
2701 | EXPORT_SYMBOL_GPL(preempt_notifier_register); | |
2702 | ||
2703 | /** | |
2704 | * preempt_notifier_unregister - no longer interested in preemption notifications | |
421cee29 | 2705 | * @notifier: notifier struct to unregister |
e107be36 AK |
2706 | * |
2707 | * This is safe to call from within a preemption notifier. | |
2708 | */ | |
2709 | void preempt_notifier_unregister(struct preempt_notifier *notifier) | |
2710 | { | |
2711 | hlist_del(¬ifier->link); | |
2712 | } | |
2713 | EXPORT_SYMBOL_GPL(preempt_notifier_unregister); | |
2714 | ||
2715 | static void fire_sched_in_preempt_notifiers(struct task_struct *curr) | |
2716 | { | |
2717 | struct preempt_notifier *notifier; | |
2718 | struct hlist_node *node; | |
2719 | ||
2720 | hlist_for_each_entry(notifier, node, &curr->preempt_notifiers, link) | |
2721 | notifier->ops->sched_in(notifier, raw_smp_processor_id()); | |
2722 | } | |
2723 | ||
2724 | static void | |
2725 | fire_sched_out_preempt_notifiers(struct task_struct *curr, | |
2726 | struct task_struct *next) | |
2727 | { | |
2728 | struct preempt_notifier *notifier; | |
2729 | struct hlist_node *node; | |
2730 | ||
2731 | hlist_for_each_entry(notifier, node, &curr->preempt_notifiers, link) | |
2732 | notifier->ops->sched_out(notifier, next); | |
2733 | } | |
2734 | ||
6d6bc0ad | 2735 | #else /* !CONFIG_PREEMPT_NOTIFIERS */ |
e107be36 AK |
2736 | |
2737 | static void fire_sched_in_preempt_notifiers(struct task_struct *curr) | |
2738 | { | |
2739 | } | |
2740 | ||
2741 | static void | |
2742 | fire_sched_out_preempt_notifiers(struct task_struct *curr, | |
2743 | struct task_struct *next) | |
2744 | { | |
2745 | } | |
2746 | ||
6d6bc0ad | 2747 | #endif /* CONFIG_PREEMPT_NOTIFIERS */ |
e107be36 | 2748 | |
4866cde0 NP |
2749 | /** |
2750 | * prepare_task_switch - prepare to switch tasks | |
2751 | * @rq: the runqueue preparing to switch | |
421cee29 | 2752 | * @prev: the current task that is being switched out |
4866cde0 NP |
2753 | * @next: the task we are going to switch to. |
2754 | * | |
2755 | * This is called with the rq lock held and interrupts off. It must | |
2756 | * be paired with a subsequent finish_task_switch after the context | |
2757 | * switch. | |
2758 | * | |
2759 | * prepare_task_switch sets up locking and calls architecture specific | |
2760 | * hooks. | |
2761 | */ | |
e107be36 AK |
2762 | static inline void |
2763 | prepare_task_switch(struct rq *rq, struct task_struct *prev, | |
2764 | struct task_struct *next) | |
4866cde0 | 2765 | { |
e107be36 | 2766 | fire_sched_out_preempt_notifiers(prev, next); |
4866cde0 NP |
2767 | prepare_lock_switch(rq, next); |
2768 | prepare_arch_switch(next); | |
2769 | } | |
2770 | ||
1da177e4 LT |
2771 | /** |
2772 | * finish_task_switch - clean up after a task-switch | |
344babaa | 2773 | * @rq: runqueue associated with task-switch |
1da177e4 LT |
2774 | * @prev: the thread we just switched away from. |
2775 | * | |
4866cde0 NP |
2776 | * finish_task_switch must be called after the context switch, paired |
2777 | * with a prepare_task_switch call before the context switch. | |
2778 | * finish_task_switch will reconcile locking set up by prepare_task_switch, | |
2779 | * and do any other architecture-specific cleanup actions. | |
1da177e4 LT |
2780 | * |
2781 | * Note that we may have delayed dropping an mm in context_switch(). If | |
41a2d6cf | 2782 | * so, we finish that here outside of the runqueue lock. (Doing it |
1da177e4 LT |
2783 | * with the lock held can cause deadlocks; see schedule() for |
2784 | * details.) | |
2785 | */ | |
a9957449 | 2786 | static void finish_task_switch(struct rq *rq, struct task_struct *prev) |
1da177e4 LT |
2787 | __releases(rq->lock) |
2788 | { | |
1da177e4 | 2789 | struct mm_struct *mm = rq->prev_mm; |
55a101f8 | 2790 | long prev_state; |
1da177e4 LT |
2791 | |
2792 | rq->prev_mm = NULL; | |
2793 | ||
2794 | /* | |
2795 | * A task struct has one reference for the use as "current". | |
c394cc9f | 2796 | * If a task dies, then it sets TASK_DEAD in tsk->state and calls |
55a101f8 ON |
2797 | * schedule one last time. The schedule call will never return, and |
2798 | * the scheduled task must drop that reference. | |
c394cc9f | 2799 | * The test for TASK_DEAD must occur while the runqueue locks are |
1da177e4 LT |
2800 | * still held, otherwise prev could be scheduled on another cpu, die |
2801 | * there before we look at prev->state, and then the reference would | |
2802 | * be dropped twice. | |
2803 | * Manfred Spraul <manfred@colorfullife.com> | |
2804 | */ | |
55a101f8 | 2805 | prev_state = prev->state; |
4866cde0 | 2806 | finish_arch_switch(prev); |
8381f65d JI |
2807 | #ifdef __ARCH_WANT_INTERRUPTS_ON_CTXSW |
2808 | local_irq_disable(); | |
2809 | #endif /* __ARCH_WANT_INTERRUPTS_ON_CTXSW */ | |
49f47433 | 2810 | perf_event_task_sched_in(current); |
8381f65d JI |
2811 | #ifdef __ARCH_WANT_INTERRUPTS_ON_CTXSW |
2812 | local_irq_enable(); | |
2813 | #endif /* __ARCH_WANT_INTERRUPTS_ON_CTXSW */ | |
4866cde0 | 2814 | finish_lock_switch(rq, prev); |
e8fa1362 | 2815 | |
e107be36 | 2816 | fire_sched_in_preempt_notifiers(current); |
1da177e4 LT |
2817 | if (mm) |
2818 | mmdrop(mm); | |
c394cc9f | 2819 | if (unlikely(prev_state == TASK_DEAD)) { |
c6fd91f0 | 2820 | /* |
2821 | * Remove function-return probe instances associated with this | |
2822 | * task and put them back on the free list. | |
9761eea8 | 2823 | */ |
c6fd91f0 | 2824 | kprobe_flush_task(prev); |
1da177e4 | 2825 | put_task_struct(prev); |
c6fd91f0 | 2826 | } |
1da177e4 LT |
2827 | } |
2828 | ||
3f029d3c GH |
2829 | #ifdef CONFIG_SMP |
2830 | ||
2831 | /* assumes rq->lock is held */ | |
2832 | static inline void pre_schedule(struct rq *rq, struct task_struct *prev) | |
2833 | { | |
2834 | if (prev->sched_class->pre_schedule) | |
2835 | prev->sched_class->pre_schedule(rq, prev); | |
2836 | } | |
2837 | ||
2838 | /* rq->lock is NOT held, but preemption is disabled */ | |
2839 | static inline void post_schedule(struct rq *rq) | |
2840 | { | |
2841 | if (rq->post_schedule) { | |
2842 | unsigned long flags; | |
2843 | ||
05fa785c | 2844 | raw_spin_lock_irqsave(&rq->lock, flags); |
3f029d3c GH |
2845 | if (rq->curr->sched_class->post_schedule) |
2846 | rq->curr->sched_class->post_schedule(rq); | |
05fa785c | 2847 | raw_spin_unlock_irqrestore(&rq->lock, flags); |
3f029d3c GH |
2848 | |
2849 | rq->post_schedule = 0; | |
2850 | } | |
2851 | } | |
2852 | ||
2853 | #else | |
da19ab51 | 2854 | |
3f029d3c GH |
2855 | static inline void pre_schedule(struct rq *rq, struct task_struct *p) |
2856 | { | |
2857 | } | |
2858 | ||
2859 | static inline void post_schedule(struct rq *rq) | |
2860 | { | |
1da177e4 LT |
2861 | } |
2862 | ||
3f029d3c GH |
2863 | #endif |
2864 | ||
1da177e4 LT |
2865 | /** |
2866 | * schedule_tail - first thing a freshly forked thread must call. | |
2867 | * @prev: the thread we just switched away from. | |
2868 | */ | |
36c8b586 | 2869 | asmlinkage void schedule_tail(struct task_struct *prev) |
1da177e4 LT |
2870 | __releases(rq->lock) |
2871 | { | |
70b97a7f IM |
2872 | struct rq *rq = this_rq(); |
2873 | ||
4866cde0 | 2874 | finish_task_switch(rq, prev); |
da19ab51 | 2875 | |
3f029d3c GH |
2876 | /* |
2877 | * FIXME: do we need to worry about rq being invalidated by the | |
2878 | * task_switch? | |
2879 | */ | |
2880 | post_schedule(rq); | |
70b97a7f | 2881 | |
4866cde0 NP |
2882 | #ifdef __ARCH_WANT_UNLOCKED_CTXSW |
2883 | /* In this case, finish_task_switch does not reenable preemption */ | |
2884 | preempt_enable(); | |
2885 | #endif | |
1da177e4 | 2886 | if (current->set_child_tid) |
b488893a | 2887 | put_user(task_pid_vnr(current), current->set_child_tid); |
1da177e4 LT |
2888 | } |
2889 | ||
2890 | /* | |
2891 | * context_switch - switch to the new MM and the new | |
2892 | * thread's register state. | |
2893 | */ | |
dd41f596 | 2894 | static inline void |
70b97a7f | 2895 | context_switch(struct rq *rq, struct task_struct *prev, |
36c8b586 | 2896 | struct task_struct *next) |
1da177e4 | 2897 | { |
dd41f596 | 2898 | struct mm_struct *mm, *oldmm; |
1da177e4 | 2899 | |
e107be36 | 2900 | prepare_task_switch(rq, prev, next); |
0a16b607 | 2901 | trace_sched_switch(rq, prev, next); |
dd41f596 IM |
2902 | mm = next->mm; |
2903 | oldmm = prev->active_mm; | |
9226d125 ZA |
2904 | /* |
2905 | * For paravirt, this is coupled with an exit in switch_to to | |
2906 | * combine the page table reload and the switch backend into | |
2907 | * one hypercall. | |
2908 | */ | |
224101ed | 2909 | arch_start_context_switch(prev); |
9226d125 | 2910 | |
710390d9 | 2911 | if (likely(!mm)) { |
1da177e4 LT |
2912 | next->active_mm = oldmm; |
2913 | atomic_inc(&oldmm->mm_count); | |
2914 | enter_lazy_tlb(oldmm, next); | |
2915 | } else | |
2916 | switch_mm(oldmm, mm, next); | |
2917 | ||
710390d9 | 2918 | if (likely(!prev->mm)) { |
1da177e4 | 2919 | prev->active_mm = NULL; |
1da177e4 LT |
2920 | rq->prev_mm = oldmm; |
2921 | } | |
3a5f5e48 IM |
2922 | /* |
2923 | * Since the runqueue lock will be released by the next | |
2924 | * task (which is an invalid locking op but in the case | |
2925 | * of the scheduler it's an obvious special-case), so we | |
2926 | * do an early lockdep release here: | |
2927 | */ | |
2928 | #ifndef __ARCH_WANT_UNLOCKED_CTXSW | |
8a25d5de | 2929 | spin_release(&rq->lock.dep_map, 1, _THIS_IP_); |
3a5f5e48 | 2930 | #endif |
1da177e4 LT |
2931 | |
2932 | /* Here we just switch the register state and the stack. */ | |
2933 | switch_to(prev, next, prev); | |
2934 | ||
dd41f596 IM |
2935 | barrier(); |
2936 | /* | |
2937 | * this_rq must be evaluated again because prev may have moved | |
2938 | * CPUs since it called schedule(), thus the 'rq' on its stack | |
2939 | * frame will be invalid. | |
2940 | */ | |
2941 | finish_task_switch(this_rq(), prev); | |
1da177e4 LT |
2942 | } |
2943 | ||
2944 | /* | |
2945 | * nr_running, nr_uninterruptible and nr_context_switches: | |
2946 | * | |
2947 | * externally visible scheduler statistics: current number of runnable | |
2948 | * threads, current number of uninterruptible-sleeping threads, total | |
2949 | * number of context switches performed since bootup. | |
2950 | */ | |
2951 | unsigned long nr_running(void) | |
2952 | { | |
2953 | unsigned long i, sum = 0; | |
2954 | ||
2955 | for_each_online_cpu(i) | |
2956 | sum += cpu_rq(i)->nr_running; | |
2957 | ||
2958 | return sum; | |
f711f609 | 2959 | } |
1da177e4 LT |
2960 | |
2961 | unsigned long nr_uninterruptible(void) | |
f711f609 | 2962 | { |
1da177e4 | 2963 | unsigned long i, sum = 0; |
f711f609 | 2964 | |
0a945022 | 2965 | for_each_possible_cpu(i) |
1da177e4 | 2966 | sum += cpu_rq(i)->nr_uninterruptible; |
f711f609 GS |
2967 | |
2968 | /* | |
1da177e4 LT |
2969 | * Since we read the counters lockless, it might be slightly |
2970 | * inaccurate. Do not allow it to go below zero though: | |
f711f609 | 2971 | */ |
1da177e4 LT |
2972 | if (unlikely((long)sum < 0)) |
2973 | sum = 0; | |
f711f609 | 2974 | |
1da177e4 | 2975 | return sum; |
f711f609 | 2976 | } |
f711f609 | 2977 | |
1da177e4 | 2978 | unsigned long long nr_context_switches(void) |
46cb4b7c | 2979 | { |
cc94abfc SR |
2980 | int i; |
2981 | unsigned long long sum = 0; | |
46cb4b7c | 2982 | |
0a945022 | 2983 | for_each_possible_cpu(i) |
1da177e4 | 2984 | sum += cpu_rq(i)->nr_switches; |
46cb4b7c | 2985 | |
1da177e4 LT |
2986 | return sum; |
2987 | } | |
483b4ee6 | 2988 | |
1da177e4 LT |
2989 | unsigned long nr_iowait(void) |
2990 | { | |
2991 | unsigned long i, sum = 0; | |
483b4ee6 | 2992 | |
0a945022 | 2993 | for_each_possible_cpu(i) |
1da177e4 | 2994 | sum += atomic_read(&cpu_rq(i)->nr_iowait); |
46cb4b7c | 2995 | |
1da177e4 LT |
2996 | return sum; |
2997 | } | |
483b4ee6 | 2998 | |
69d25870 AV |
2999 | unsigned long nr_iowait_cpu(void) |
3000 | { | |
3001 | struct rq *this = this_rq(); | |
3002 | return atomic_read(&this->nr_iowait); | |
3003 | } | |
46cb4b7c | 3004 | |
69d25870 AV |
3005 | unsigned long this_cpu_load(void) |
3006 | { | |
3007 | struct rq *this = this_rq(); | |
3008 | return this->cpu_load[0]; | |
3009 | } | |
e790fb0b | 3010 | |
46cb4b7c | 3011 | |
dce48a84 TG |
3012 | /* Variables and functions for calc_load */ |
3013 | static atomic_long_t calc_load_tasks; | |
3014 | static unsigned long calc_load_update; | |
3015 | unsigned long avenrun[3]; | |
3016 | EXPORT_SYMBOL(avenrun); | |
46cb4b7c | 3017 | |
2d02494f TG |
3018 | /** |
3019 | * get_avenrun - get the load average array | |
3020 | * @loads: pointer to dest load array | |
3021 | * @offset: offset to add | |
3022 | * @shift: shift count to shift the result left | |
3023 | * | |
3024 | * These values are estimates at best, so no need for locking. | |
3025 | */ | |
3026 | void get_avenrun(unsigned long *loads, unsigned long offset, int shift) | |
3027 | { | |
3028 | loads[0] = (avenrun[0] + offset) << shift; | |
3029 | loads[1] = (avenrun[1] + offset) << shift; | |
3030 | loads[2] = (avenrun[2] + offset) << shift; | |
46cb4b7c | 3031 | } |
46cb4b7c | 3032 | |
dce48a84 TG |
3033 | static unsigned long |
3034 | calc_load(unsigned long load, unsigned long exp, unsigned long active) | |
db1b1fef | 3035 | { |
dce48a84 TG |
3036 | load *= exp; |
3037 | load += active * (FIXED_1 - exp); | |
3038 | return load >> FSHIFT; | |
3039 | } | |
46cb4b7c SS |
3040 | |
3041 | /* | |
dce48a84 TG |
3042 | * calc_load - update the avenrun load estimates 10 ticks after the |
3043 | * CPUs have updated calc_load_tasks. | |
7835b98b | 3044 | */ |
dce48a84 | 3045 | void calc_global_load(void) |
7835b98b | 3046 | { |
dce48a84 TG |
3047 | unsigned long upd = calc_load_update + 10; |
3048 | long active; | |
1da177e4 | 3049 | |
dce48a84 TG |
3050 | if (time_before(jiffies, upd)) |
3051 | return; | |
1da177e4 | 3052 | |
dce48a84 TG |
3053 | active = atomic_long_read(&calc_load_tasks); |
3054 | active = active > 0 ? active * FIXED_1 : 0; | |
1da177e4 | 3055 | |
dce48a84 TG |
3056 | avenrun[0] = calc_load(avenrun[0], EXP_1, active); |
3057 | avenrun[1] = calc_load(avenrun[1], EXP_5, active); | |
3058 | avenrun[2] = calc_load(avenrun[2], EXP_15, active); | |
dd41f596 | 3059 | |
dce48a84 TG |
3060 | calc_load_update += LOAD_FREQ; |
3061 | } | |
1da177e4 | 3062 | |
dce48a84 TG |
3063 | /* |
3064 | * Either called from update_cpu_load() or from a cpu going idle | |
3065 | */ | |
3066 | static void calc_load_account_active(struct rq *this_rq) | |
3067 | { | |
3068 | long nr_active, delta; | |
08c183f3 | 3069 | |
dce48a84 TG |
3070 | nr_active = this_rq->nr_running; |
3071 | nr_active += (long) this_rq->nr_uninterruptible; | |
783609c6 | 3072 | |
dce48a84 TG |
3073 | if (nr_active != this_rq->calc_load_active) { |
3074 | delta = nr_active - this_rq->calc_load_active; | |
3075 | this_rq->calc_load_active = nr_active; | |
3076 | atomic_long_add(delta, &calc_load_tasks); | |
1da177e4 | 3077 | } |
46cb4b7c SS |
3078 | } |
3079 | ||
3080 | /* | |
dd41f596 IM |
3081 | * Update rq->cpu_load[] statistics. This function is usually called every |
3082 | * scheduler tick (TICK_NSEC). | |
46cb4b7c | 3083 | */ |
dd41f596 | 3084 | static void update_cpu_load(struct rq *this_rq) |
46cb4b7c | 3085 | { |
495eca49 | 3086 | unsigned long this_load = this_rq->load.weight; |
dd41f596 | 3087 | int i, scale; |
46cb4b7c | 3088 | |
dd41f596 | 3089 | this_rq->nr_load_updates++; |
46cb4b7c | 3090 | |
dd41f596 IM |
3091 | /* Update our load: */ |
3092 | for (i = 0, scale = 1; i < CPU_LOAD_IDX_MAX; i++, scale += scale) { | |
3093 | unsigned long old_load, new_load; | |
7d1e6a9b | 3094 | |
dd41f596 | 3095 | /* scale is effectively 1 << i now, and >> i divides by scale */ |
46cb4b7c | 3096 | |
dd41f596 IM |
3097 | old_load = this_rq->cpu_load[i]; |
3098 | new_load = this_load; | |
a25707f3 IM |
3099 | /* |
3100 | * Round up the averaging division if load is increasing. This | |
3101 | * prevents us from getting stuck on 9 if the load is 10, for | |
3102 | * example. | |
3103 | */ | |
3104 | if (new_load > old_load) | |
3105 | new_load += scale-1; | |
dd41f596 IM |
3106 | this_rq->cpu_load[i] = (old_load*(scale-1) + new_load) >> i; |
3107 | } | |
46cb4b7c | 3108 | |
dce48a84 TG |
3109 | if (time_after_eq(jiffies, this_rq->calc_load_update)) { |
3110 | this_rq->calc_load_update += LOAD_FREQ; | |
3111 | calc_load_account_active(this_rq); | |
46cb4b7c | 3112 | } |
46cb4b7c SS |
3113 | } |
3114 | ||
dd41f596 | 3115 | #ifdef CONFIG_SMP |
8a0be9ef | 3116 | |
46cb4b7c | 3117 | /* |
38022906 PZ |
3118 | * sched_exec - execve() is a valuable balancing opportunity, because at |
3119 | * this point the task has the smallest effective memory and cache footprint. | |
46cb4b7c | 3120 | */ |
38022906 | 3121 | void sched_exec(void) |
46cb4b7c | 3122 | { |
38022906 | 3123 | struct task_struct *p = current; |
70b97a7f | 3124 | struct migration_req req; |
38022906 | 3125 | int dest_cpu, this_cpu; |
1da177e4 | 3126 | unsigned long flags; |
70b97a7f | 3127 | struct rq *rq; |
46cb4b7c | 3128 | |
38022906 PZ |
3129 | again: |
3130 | this_cpu = get_cpu(); | |
3131 | dest_cpu = select_task_rq(p, SD_BALANCE_EXEC, 0); | |
3132 | if (dest_cpu == this_cpu) { | |
3133 | put_cpu(); | |
3134 | return; | |
46cb4b7c SS |
3135 | } |
3136 | ||
1da177e4 | 3137 | rq = task_rq_lock(p, &flags); |
38022906 PZ |
3138 | put_cpu(); |
3139 | ||
46cb4b7c | 3140 | /* |
38022906 | 3141 | * select_task_rq() can race against ->cpus_allowed |
46cb4b7c | 3142 | */ |
96f874e2 | 3143 | if (!cpumask_test_cpu(dest_cpu, &p->cpus_allowed) |
38022906 PZ |
3144 | || unlikely(!cpu_active(dest_cpu))) { |
3145 | task_rq_unlock(rq, &flags); | |
3146 | goto again; | |
46cb4b7c SS |
3147 | } |
3148 | ||
1da177e4 LT |
3149 | /* force the process onto the specified CPU */ |
3150 | if (migrate_task(p, dest_cpu, &req)) { | |
3151 | /* Need to wait for migration thread (might exit: take ref). */ | |
3152 | struct task_struct *mt = rq->migration_thread; | |
dd41f596 | 3153 | |
1da177e4 LT |
3154 | get_task_struct(mt); |
3155 | task_rq_unlock(rq, &flags); | |
3156 | wake_up_process(mt); | |
3157 | put_task_struct(mt); | |
3158 | wait_for_completion(&req.done); | |
dd41f596 | 3159 | |
1da177e4 LT |
3160 | return; |
3161 | } | |
1da177e4 | 3162 | task_rq_unlock(rq, &flags); |
1da177e4 | 3163 | } |
dd41f596 | 3164 | |
1da177e4 LT |
3165 | #endif |
3166 | ||
1da177e4 LT |
3167 | DEFINE_PER_CPU(struct kernel_stat, kstat); |
3168 | ||
3169 | EXPORT_PER_CPU_SYMBOL(kstat); | |
3170 | ||
3171 | /* | |
c5f8d995 | 3172 | * Return any ns on the sched_clock that have not yet been accounted in |
f06febc9 | 3173 | * @p in case that task is currently running. |
c5f8d995 HS |
3174 | * |
3175 | * Called with task_rq_lock() held on @rq. | |
1da177e4 | 3176 | */ |
c5f8d995 HS |
3177 | static u64 do_task_delta_exec(struct task_struct *p, struct rq *rq) |
3178 | { | |
3179 | u64 ns = 0; | |
3180 | ||
3181 | if (task_current(rq, p)) { | |
3182 | update_rq_clock(rq); | |
3183 | ns = rq->clock - p->se.exec_start; | |
3184 | if ((s64)ns < 0) | |
3185 | ns = 0; | |
3186 | } | |
3187 | ||
3188 | return ns; | |
3189 | } | |
3190 | ||
bb34d92f | 3191 | unsigned long long task_delta_exec(struct task_struct *p) |
1da177e4 | 3192 | { |
1da177e4 | 3193 | unsigned long flags; |
41b86e9c | 3194 | struct rq *rq; |
bb34d92f | 3195 | u64 ns = 0; |
48f24c4d | 3196 | |
41b86e9c | 3197 | rq = task_rq_lock(p, &flags); |
c5f8d995 HS |
3198 | ns = do_task_delta_exec(p, rq); |
3199 | task_rq_unlock(rq, &flags); | |
1508487e | 3200 | |
c5f8d995 HS |
3201 | return ns; |
3202 | } | |
f06febc9 | 3203 | |
c5f8d995 HS |
3204 | /* |
3205 | * Return accounted runtime for the task. | |
3206 | * In case the task is currently running, return the runtime plus current's | |
3207 | * pending runtime that have not been accounted yet. | |
3208 | */ | |
3209 | unsigned long long task_sched_runtime(struct task_struct *p) | |
3210 | { | |
3211 | unsigned long flags; | |
3212 | struct rq *rq; | |
3213 | u64 ns = 0; | |
3214 | ||
3215 | rq = task_rq_lock(p, &flags); | |
3216 | ns = p->se.sum_exec_runtime + do_task_delta_exec(p, rq); | |
3217 | task_rq_unlock(rq, &flags); | |
3218 | ||
3219 | return ns; | |
3220 | } | |
48f24c4d | 3221 | |
c5f8d995 HS |
3222 | /* |
3223 | * Return sum_exec_runtime for the thread group. | |
3224 | * In case the task is currently running, return the sum plus current's | |
3225 | * pending runtime that have not been accounted yet. | |
3226 | * | |
3227 | * Note that the thread group might have other running tasks as well, | |
3228 | * so the return value not includes other pending runtime that other | |
3229 | * running tasks might have. | |
3230 | */ | |
3231 | unsigned long long thread_group_sched_runtime(struct task_struct *p) | |
3232 | { | |
3233 | struct task_cputime totals; | |
3234 | unsigned long flags; | |
3235 | struct rq *rq; | |
3236 | u64 ns; | |
3237 | ||
3238 | rq = task_rq_lock(p, &flags); | |
3239 | thread_group_cputime(p, &totals); | |
3240 | ns = totals.sum_exec_runtime + do_task_delta_exec(p, rq); | |
41b86e9c | 3241 | task_rq_unlock(rq, &flags); |
48f24c4d | 3242 | |
1da177e4 LT |
3243 | return ns; |
3244 | } | |
3245 | ||
1da177e4 LT |
3246 | /* |
3247 | * Account user cpu time to a process. | |
3248 | * @p: the process that the cpu time gets accounted to | |
1da177e4 | 3249 | * @cputime: the cpu time spent in user space since the last update |
457533a7 | 3250 | * @cputime_scaled: cputime scaled by cpu frequency |
1da177e4 | 3251 | */ |
457533a7 MS |
3252 | void account_user_time(struct task_struct *p, cputime_t cputime, |
3253 | cputime_t cputime_scaled) | |
1da177e4 LT |
3254 | { |
3255 | struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat; | |
3256 | cputime64_t tmp; | |
3257 | ||
457533a7 | 3258 | /* Add user time to process. */ |
1da177e4 | 3259 | p->utime = cputime_add(p->utime, cputime); |
457533a7 | 3260 | p->utimescaled = cputime_add(p->utimescaled, cputime_scaled); |
f06febc9 | 3261 | account_group_user_time(p, cputime); |
1da177e4 LT |
3262 | |
3263 | /* Add user time to cpustat. */ | |
3264 | tmp = cputime_to_cputime64(cputime); | |
3265 | if (TASK_NICE(p) > 0) | |
3266 | cpustat->nice = cputime64_add(cpustat->nice, tmp); | |
3267 | else | |
3268 | cpustat->user = cputime64_add(cpustat->user, tmp); | |
ef12fefa BR |
3269 | |
3270 | cpuacct_update_stats(p, CPUACCT_STAT_USER, cputime); | |
49b5cf34 JL |
3271 | /* Account for user time used */ |
3272 | acct_update_integrals(p); | |
1da177e4 LT |
3273 | } |
3274 | ||
94886b84 LV |
3275 | /* |
3276 | * Account guest cpu time to a process. | |
3277 | * @p: the process that the cpu time gets accounted to | |
3278 | * @cputime: the cpu time spent in virtual machine since the last update | |
457533a7 | 3279 | * @cputime_scaled: cputime scaled by cpu frequency |
94886b84 | 3280 | */ |
457533a7 MS |
3281 | static void account_guest_time(struct task_struct *p, cputime_t cputime, |
3282 | cputime_t cputime_scaled) | |
94886b84 LV |
3283 | { |
3284 | cputime64_t tmp; | |
3285 | struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat; | |
3286 | ||
3287 | tmp = cputime_to_cputime64(cputime); | |
3288 | ||
457533a7 | 3289 | /* Add guest time to process. */ |
94886b84 | 3290 | p->utime = cputime_add(p->utime, cputime); |
457533a7 | 3291 | p->utimescaled = cputime_add(p->utimescaled, cputime_scaled); |
f06febc9 | 3292 | account_group_user_time(p, cputime); |
94886b84 LV |
3293 | p->gtime = cputime_add(p->gtime, cputime); |
3294 | ||
457533a7 | 3295 | /* Add guest time to cpustat. */ |
ce0e7b28 RO |
3296 | if (TASK_NICE(p) > 0) { |
3297 | cpustat->nice = cputime64_add(cpustat->nice, tmp); | |
3298 | cpustat->guest_nice = cputime64_add(cpustat->guest_nice, tmp); | |
3299 | } else { | |
3300 | cpustat->user = cputime64_add(cpustat->user, tmp); | |
3301 | cpustat->guest = cputime64_add(cpustat->guest, tmp); | |
3302 | } | |
94886b84 LV |
3303 | } |
3304 | ||
1da177e4 LT |
3305 | /* |
3306 | * Account system cpu time to a process. | |
3307 | * @p: the process that the cpu time gets accounted to | |
3308 | * @hardirq_offset: the offset to subtract from hardirq_count() | |
3309 | * @cputime: the cpu time spent in kernel space since the last update | |
457533a7 | 3310 | * @cputime_scaled: cputime scaled by cpu frequency |
1da177e4 LT |
3311 | */ |
3312 | void account_system_time(struct task_struct *p, int hardirq_offset, | |
457533a7 | 3313 | cputime_t cputime, cputime_t cputime_scaled) |
1da177e4 LT |
3314 | { |
3315 | struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat; | |
1da177e4 LT |
3316 | cputime64_t tmp; |
3317 | ||
983ed7a6 | 3318 | if ((p->flags & PF_VCPU) && (irq_count() - hardirq_offset == 0)) { |
457533a7 | 3319 | account_guest_time(p, cputime, cputime_scaled); |
983ed7a6 HH |
3320 | return; |
3321 | } | |
94886b84 | 3322 | |
457533a7 | 3323 | /* Add system time to process. */ |
1da177e4 | 3324 | p->stime = cputime_add(p->stime, cputime); |
457533a7 | 3325 | p->stimescaled = cputime_add(p->stimescaled, cputime_scaled); |
f06febc9 | 3326 | account_group_system_time(p, cputime); |
1da177e4 LT |
3327 | |
3328 | /* Add system time to cpustat. */ | |
3329 | tmp = cputime_to_cputime64(cputime); | |
3330 | if (hardirq_count() - hardirq_offset) | |
3331 | cpustat->irq = cputime64_add(cpustat->irq, tmp); | |
3332 | else if (softirq_count()) | |
3333 | cpustat->softirq = cputime64_add(cpustat->softirq, tmp); | |
1da177e4 | 3334 | else |
79741dd3 MS |
3335 | cpustat->system = cputime64_add(cpustat->system, tmp); |
3336 | ||
ef12fefa BR |
3337 | cpuacct_update_stats(p, CPUACCT_STAT_SYSTEM, cputime); |
3338 | ||
1da177e4 LT |
3339 | /* Account for system time used */ |
3340 | acct_update_integrals(p); | |
1da177e4 LT |
3341 | } |
3342 | ||
c66f08be | 3343 | /* |
1da177e4 | 3344 | * Account for involuntary wait time. |
1da177e4 | 3345 | * @steal: the cpu time spent in involuntary wait |
c66f08be | 3346 | */ |
79741dd3 | 3347 | void account_steal_time(cputime_t cputime) |
c66f08be | 3348 | { |
79741dd3 MS |
3349 | struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat; |
3350 | cputime64_t cputime64 = cputime_to_cputime64(cputime); | |
3351 | ||
3352 | cpustat->steal = cputime64_add(cpustat->steal, cputime64); | |
c66f08be MN |
3353 | } |
3354 | ||
1da177e4 | 3355 | /* |
79741dd3 MS |
3356 | * Account for idle time. |
3357 | * @cputime: the cpu time spent in idle wait | |
1da177e4 | 3358 | */ |
79741dd3 | 3359 | void account_idle_time(cputime_t cputime) |
1da177e4 LT |
3360 | { |
3361 | struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat; | |
79741dd3 | 3362 | cputime64_t cputime64 = cputime_to_cputime64(cputime); |
70b97a7f | 3363 | struct rq *rq = this_rq(); |
1da177e4 | 3364 | |
79741dd3 MS |
3365 | if (atomic_read(&rq->nr_iowait) > 0) |
3366 | cpustat->iowait = cputime64_add(cpustat->iowait, cputime64); | |
3367 | else | |
3368 | cpustat->idle = cputime64_add(cpustat->idle, cputime64); | |
1da177e4 LT |
3369 | } |
3370 | ||
79741dd3 MS |
3371 | #ifndef CONFIG_VIRT_CPU_ACCOUNTING |
3372 | ||
3373 | /* | |
3374 | * Account a single tick of cpu time. | |
3375 | * @p: the process that the cpu time gets accounted to | |
3376 | * @user_tick: indicates if the tick is a user or a system tick | |
3377 | */ | |
3378 | void account_process_tick(struct task_struct *p, int user_tick) | |
3379 | { | |
a42548a1 | 3380 | cputime_t one_jiffy_scaled = cputime_to_scaled(cputime_one_jiffy); |
79741dd3 MS |
3381 | struct rq *rq = this_rq(); |
3382 | ||
3383 | if (user_tick) | |
a42548a1 | 3384 | account_user_time(p, cputime_one_jiffy, one_jiffy_scaled); |
f5f293a4 | 3385 | else if ((p != rq->idle) || (irq_count() != HARDIRQ_OFFSET)) |
a42548a1 | 3386 | account_system_time(p, HARDIRQ_OFFSET, cputime_one_jiffy, |
79741dd3 MS |
3387 | one_jiffy_scaled); |
3388 | else | |
a42548a1 | 3389 | account_idle_time(cputime_one_jiffy); |
79741dd3 MS |
3390 | } |
3391 | ||
3392 | /* | |
3393 | * Account multiple ticks of steal time. | |
3394 | * @p: the process from which the cpu time has been stolen | |
3395 | * @ticks: number of stolen ticks | |
3396 | */ | |
3397 | void account_steal_ticks(unsigned long ticks) | |
3398 | { | |
3399 | account_steal_time(jiffies_to_cputime(ticks)); | |
3400 | } | |
3401 | ||
3402 | /* | |
3403 | * Account multiple ticks of idle time. | |
3404 | * @ticks: number of stolen ticks | |
3405 | */ | |
3406 | void account_idle_ticks(unsigned long ticks) | |
3407 | { | |
3408 | account_idle_time(jiffies_to_cputime(ticks)); | |
1da177e4 LT |
3409 | } |
3410 | ||
79741dd3 MS |
3411 | #endif |
3412 | ||
49048622 BS |
3413 | /* |
3414 | * Use precise platform statistics if available: | |
3415 | */ | |
3416 | #ifdef CONFIG_VIRT_CPU_ACCOUNTING | |
d180c5bc | 3417 | void task_times(struct task_struct *p, cputime_t *ut, cputime_t *st) |
49048622 | 3418 | { |
d99ca3b9 HS |
3419 | *ut = p->utime; |
3420 | *st = p->stime; | |
49048622 BS |
3421 | } |
3422 | ||
0cf55e1e | 3423 | void thread_group_times(struct task_struct *p, cputime_t *ut, cputime_t *st) |
49048622 | 3424 | { |
0cf55e1e HS |
3425 | struct task_cputime cputime; |
3426 | ||
3427 | thread_group_cputime(p, &cputime); | |
3428 | ||
3429 | *ut = cputime.utime; | |
3430 | *st = cputime.stime; | |
49048622 BS |
3431 | } |
3432 | #else | |
761b1d26 HS |
3433 | |
3434 | #ifndef nsecs_to_cputime | |
b7b20df9 | 3435 | # define nsecs_to_cputime(__nsecs) nsecs_to_jiffies(__nsecs) |
761b1d26 HS |
3436 | #endif |
3437 | ||
d180c5bc | 3438 | void task_times(struct task_struct *p, cputime_t *ut, cputime_t *st) |
49048622 | 3439 | { |
d99ca3b9 | 3440 | cputime_t rtime, utime = p->utime, total = cputime_add(utime, p->stime); |
49048622 BS |
3441 | |
3442 | /* | |
3443 | * Use CFS's precise accounting: | |
3444 | */ | |
d180c5bc | 3445 | rtime = nsecs_to_cputime(p->se.sum_exec_runtime); |
49048622 BS |
3446 | |
3447 | if (total) { | |
d180c5bc HS |
3448 | u64 temp; |
3449 | ||
3450 | temp = (u64)(rtime * utime); | |
49048622 | 3451 | do_div(temp, total); |
d180c5bc HS |
3452 | utime = (cputime_t)temp; |
3453 | } else | |
3454 | utime = rtime; | |
49048622 | 3455 | |
d180c5bc HS |
3456 | /* |
3457 | * Compare with previous values, to keep monotonicity: | |
3458 | */ | |
761b1d26 | 3459 | p->prev_utime = max(p->prev_utime, utime); |
d99ca3b9 | 3460 | p->prev_stime = max(p->prev_stime, cputime_sub(rtime, p->prev_utime)); |
49048622 | 3461 | |
d99ca3b9 HS |
3462 | *ut = p->prev_utime; |
3463 | *st = p->prev_stime; | |
49048622 BS |
3464 | } |
3465 | ||
0cf55e1e HS |
3466 | /* |
3467 | * Must be called with siglock held. | |
3468 | */ | |
3469 | void thread_group_times(struct task_struct *p, cputime_t *ut, cputime_t *st) | |
49048622 | 3470 | { |
0cf55e1e HS |
3471 | struct signal_struct *sig = p->signal; |
3472 | struct task_cputime cputime; | |
3473 | cputime_t rtime, utime, total; | |
49048622 | 3474 | |
0cf55e1e | 3475 | thread_group_cputime(p, &cputime); |
49048622 | 3476 | |
0cf55e1e HS |
3477 | total = cputime_add(cputime.utime, cputime.stime); |
3478 | rtime = nsecs_to_cputime(cputime.sum_exec_runtime); | |
49048622 | 3479 | |
0cf55e1e HS |
3480 | if (total) { |
3481 | u64 temp; | |
49048622 | 3482 | |
0cf55e1e HS |
3483 | temp = (u64)(rtime * cputime.utime); |
3484 | do_div(temp, total); | |
3485 | utime = (cputime_t)temp; | |
3486 | } else | |
3487 | utime = rtime; | |
3488 | ||
3489 | sig->prev_utime = max(sig->prev_utime, utime); | |
3490 | sig->prev_stime = max(sig->prev_stime, | |
3491 | cputime_sub(rtime, sig->prev_utime)); | |
3492 | ||
3493 | *ut = sig->prev_utime; | |
3494 | *st = sig->prev_stime; | |
49048622 | 3495 | } |
49048622 | 3496 | #endif |
49048622 | 3497 | |
7835b98b CL |
3498 | /* |
3499 | * This function gets called by the timer code, with HZ frequency. | |
3500 | * We call it with interrupts disabled. | |
3501 | * | |
3502 | * It also gets called by the fork code, when changing the parent's | |
3503 | * timeslices. | |
3504 | */ | |
3505 | void scheduler_tick(void) | |
3506 | { | |
7835b98b CL |
3507 | int cpu = smp_processor_id(); |
3508 | struct rq *rq = cpu_rq(cpu); | |
dd41f596 | 3509 | struct task_struct *curr = rq->curr; |
3e51f33f PZ |
3510 | |
3511 | sched_clock_tick(); | |
dd41f596 | 3512 | |
05fa785c | 3513 | raw_spin_lock(&rq->lock); |
3e51f33f | 3514 | update_rq_clock(rq); |
f1a438d8 | 3515 | update_cpu_load(rq); |
fa85ae24 | 3516 | curr->sched_class->task_tick(rq, curr, 0); |
05fa785c | 3517 | raw_spin_unlock(&rq->lock); |
7835b98b | 3518 | |
49f47433 | 3519 | perf_event_task_tick(curr); |
e220d2dc | 3520 | |
e418e1c2 | 3521 | #ifdef CONFIG_SMP |
dd41f596 IM |
3522 | rq->idle_at_tick = idle_cpu(cpu); |
3523 | trigger_load_balance(rq, cpu); | |
e418e1c2 | 3524 | #endif |
1da177e4 LT |
3525 | } |
3526 | ||
132380a0 | 3527 | notrace unsigned long get_parent_ip(unsigned long addr) |
6cd8a4bb SR |
3528 | { |
3529 | if (in_lock_functions(addr)) { | |
3530 | addr = CALLER_ADDR2; | |
3531 | if (in_lock_functions(addr)) | |
3532 | addr = CALLER_ADDR3; | |
3533 | } | |
3534 | return addr; | |
3535 | } | |
1da177e4 | 3536 | |
7e49fcce SR |
3537 | #if defined(CONFIG_PREEMPT) && (defined(CONFIG_DEBUG_PREEMPT) || \ |
3538 | defined(CONFIG_PREEMPT_TRACER)) | |
3539 | ||
43627582 | 3540 | void __kprobes add_preempt_count(int val) |
1da177e4 | 3541 | { |
6cd8a4bb | 3542 | #ifdef CONFIG_DEBUG_PREEMPT |
1da177e4 LT |
3543 | /* |
3544 | * Underflow? | |
3545 | */ | |
9a11b49a IM |
3546 | if (DEBUG_LOCKS_WARN_ON((preempt_count() < 0))) |
3547 | return; | |
6cd8a4bb | 3548 | #endif |
1da177e4 | 3549 | preempt_count() += val; |
6cd8a4bb | 3550 | #ifdef CONFIG_DEBUG_PREEMPT |
1da177e4 LT |
3551 | /* |
3552 | * Spinlock count overflowing soon? | |
3553 | */ | |
33859f7f MOS |
3554 | DEBUG_LOCKS_WARN_ON((preempt_count() & PREEMPT_MASK) >= |
3555 | PREEMPT_MASK - 10); | |
6cd8a4bb SR |
3556 | #endif |
3557 | if (preempt_count() == val) | |
3558 | trace_preempt_off(CALLER_ADDR0, get_parent_ip(CALLER_ADDR1)); | |
1da177e4 LT |
3559 | } |
3560 | EXPORT_SYMBOL(add_preempt_count); | |
3561 | ||
43627582 | 3562 | void __kprobes sub_preempt_count(int val) |
1da177e4 | 3563 | { |
6cd8a4bb | 3564 | #ifdef CONFIG_DEBUG_PREEMPT |
1da177e4 LT |
3565 | /* |
3566 | * Underflow? | |
3567 | */ | |
01e3eb82 | 3568 | if (DEBUG_LOCKS_WARN_ON(val > preempt_count())) |
9a11b49a | 3569 | return; |
1da177e4 LT |
3570 | /* |
3571 | * Is the spinlock portion underflowing? | |
3572 | */ | |
9a11b49a IM |
3573 | if (DEBUG_LOCKS_WARN_ON((val < PREEMPT_MASK) && |
3574 | !(preempt_count() & PREEMPT_MASK))) | |
3575 | return; | |
6cd8a4bb | 3576 | #endif |
9a11b49a | 3577 | |
6cd8a4bb SR |
3578 | if (preempt_count() == val) |
3579 | trace_preempt_on(CALLER_ADDR0, get_parent_ip(CALLER_ADDR1)); | |
1da177e4 LT |
3580 | preempt_count() -= val; |
3581 | } | |
3582 | EXPORT_SYMBOL(sub_preempt_count); | |
3583 | ||
3584 | #endif | |
3585 | ||
3586 | /* | |
dd41f596 | 3587 | * Print scheduling while atomic bug: |
1da177e4 | 3588 | */ |
dd41f596 | 3589 | static noinline void __schedule_bug(struct task_struct *prev) |
1da177e4 | 3590 | { |
838225b4 SS |
3591 | struct pt_regs *regs = get_irq_regs(); |
3592 | ||
3df0fc5b PZ |
3593 | printk(KERN_ERR "BUG: scheduling while atomic: %s/%d/0x%08x\n", |
3594 | prev->comm, prev->pid, preempt_count()); | |
838225b4 | 3595 | |
dd41f596 | 3596 | debug_show_held_locks(prev); |
e21f5b15 | 3597 | print_modules(); |
dd41f596 IM |
3598 | if (irqs_disabled()) |
3599 | print_irqtrace_events(prev); | |
838225b4 SS |
3600 | |
3601 | if (regs) | |
3602 | show_regs(regs); | |
3603 | else | |
3604 | dump_stack(); | |
dd41f596 | 3605 | } |
1da177e4 | 3606 | |
dd41f596 IM |
3607 | /* |
3608 | * Various schedule()-time debugging checks and statistics: | |
3609 | */ | |
3610 | static inline void schedule_debug(struct task_struct *prev) | |
3611 | { | |
1da177e4 | 3612 | /* |
41a2d6cf | 3613 | * Test if we are atomic. Since do_exit() needs to call into |
1da177e4 LT |
3614 | * schedule() atomically, we ignore that path for now. |
3615 | * Otherwise, whine if we are scheduling when we should not be. | |
3616 | */ | |
3f33a7ce | 3617 | if (unlikely(in_atomic_preempt_off() && !prev->exit_state)) |
dd41f596 IM |
3618 | __schedule_bug(prev); |
3619 | ||
1da177e4 LT |
3620 | profile_hit(SCHED_PROFILING, __builtin_return_address(0)); |
3621 | ||
2d72376b | 3622 | schedstat_inc(this_rq(), sched_count); |
b8efb561 IM |
3623 | #ifdef CONFIG_SCHEDSTATS |
3624 | if (unlikely(prev->lock_depth >= 0)) { | |
2d72376b IM |
3625 | schedstat_inc(this_rq(), bkl_count); |
3626 | schedstat_inc(prev, sched_info.bkl_count); | |
b8efb561 IM |
3627 | } |
3628 | #endif | |
dd41f596 IM |
3629 | } |
3630 | ||
6cecd084 | 3631 | static void put_prev_task(struct rq *rq, struct task_struct *prev) |
df1c99d4 | 3632 | { |
6cecd084 PZ |
3633 | if (prev->state == TASK_RUNNING) { |
3634 | u64 runtime = prev->se.sum_exec_runtime; | |
df1c99d4 | 3635 | |
6cecd084 PZ |
3636 | runtime -= prev->se.prev_sum_exec_runtime; |
3637 | runtime = min_t(u64, runtime, 2*sysctl_sched_migration_cost); | |
df1c99d4 MG |
3638 | |
3639 | /* | |
3640 | * In order to avoid avg_overlap growing stale when we are | |
3641 | * indeed overlapping and hence not getting put to sleep, grow | |
3642 | * the avg_overlap on preemption. | |
3643 | * | |
3644 | * We use the average preemption runtime because that | |
3645 | * correlates to the amount of cache footprint a task can | |
3646 | * build up. | |
3647 | */ | |
6cecd084 | 3648 | update_avg(&prev->se.avg_overlap, runtime); |
df1c99d4 | 3649 | } |
6cecd084 | 3650 | prev->sched_class->put_prev_task(rq, prev); |
df1c99d4 MG |
3651 | } |
3652 | ||
dd41f596 IM |
3653 | /* |
3654 | * Pick up the highest-prio task: | |
3655 | */ | |
3656 | static inline struct task_struct * | |
b67802ea | 3657 | pick_next_task(struct rq *rq) |
dd41f596 | 3658 | { |
5522d5d5 | 3659 | const struct sched_class *class; |
dd41f596 | 3660 | struct task_struct *p; |
1da177e4 LT |
3661 | |
3662 | /* | |
dd41f596 IM |
3663 | * Optimization: we know that if all tasks are in |
3664 | * the fair class we can call that function directly: | |
1da177e4 | 3665 | */ |
dd41f596 | 3666 | if (likely(rq->nr_running == rq->cfs.nr_running)) { |
fb8d4724 | 3667 | p = fair_sched_class.pick_next_task(rq); |
dd41f596 IM |
3668 | if (likely(p)) |
3669 | return p; | |
1da177e4 LT |
3670 | } |
3671 | ||
dd41f596 IM |
3672 | class = sched_class_highest; |
3673 | for ( ; ; ) { | |
fb8d4724 | 3674 | p = class->pick_next_task(rq); |
dd41f596 IM |
3675 | if (p) |
3676 | return p; | |
3677 | /* | |
3678 | * Will never be NULL as the idle class always | |
3679 | * returns a non-NULL p: | |
3680 | */ | |
3681 | class = class->next; | |
3682 | } | |
3683 | } | |
1da177e4 | 3684 | |
dd41f596 IM |
3685 | /* |
3686 | * schedule() is the main scheduler function. | |
3687 | */ | |
ff743345 | 3688 | asmlinkage void __sched schedule(void) |
dd41f596 IM |
3689 | { |
3690 | struct task_struct *prev, *next; | |
67ca7bde | 3691 | unsigned long *switch_count; |
dd41f596 | 3692 | struct rq *rq; |
31656519 | 3693 | int cpu; |
dd41f596 | 3694 | |
ff743345 PZ |
3695 | need_resched: |
3696 | preempt_disable(); | |
dd41f596 IM |
3697 | cpu = smp_processor_id(); |
3698 | rq = cpu_rq(cpu); | |
d6714c22 | 3699 | rcu_sched_qs(cpu); |
dd41f596 IM |
3700 | prev = rq->curr; |
3701 | switch_count = &prev->nivcsw; | |
3702 | ||
3703 | release_kernel_lock(prev); | |
3704 | need_resched_nonpreemptible: | |
3705 | ||
3706 | schedule_debug(prev); | |
1da177e4 | 3707 | |
31656519 | 3708 | if (sched_feat(HRTICK)) |
f333fdc9 | 3709 | hrtick_clear(rq); |
8f4d37ec | 3710 | |
05fa785c | 3711 | raw_spin_lock_irq(&rq->lock); |
3e51f33f | 3712 | update_rq_clock(rq); |
1e819950 | 3713 | clear_tsk_need_resched(prev); |
1da177e4 | 3714 | |
1da177e4 | 3715 | if (prev->state && !(preempt_count() & PREEMPT_ACTIVE)) { |
16882c1e | 3716 | if (unlikely(signal_pending_state(prev->state, prev))) |
1da177e4 | 3717 | prev->state = TASK_RUNNING; |
16882c1e | 3718 | else |
2e1cb74a | 3719 | deactivate_task(rq, prev, 1); |
dd41f596 | 3720 | switch_count = &prev->nvcsw; |
1da177e4 LT |
3721 | } |
3722 | ||
3f029d3c | 3723 | pre_schedule(rq, prev); |
f65eda4f | 3724 | |
dd41f596 | 3725 | if (unlikely(!rq->nr_running)) |
1da177e4 | 3726 | idle_balance(cpu, rq); |
1da177e4 | 3727 | |
df1c99d4 | 3728 | put_prev_task(rq, prev); |
b67802ea | 3729 | next = pick_next_task(rq); |
1da177e4 | 3730 | |
1da177e4 | 3731 | if (likely(prev != next)) { |
673a90a1 | 3732 | sched_info_switch(prev, next); |
49f47433 | 3733 | perf_event_task_sched_out(prev, next); |
673a90a1 | 3734 | |
1da177e4 LT |
3735 | rq->nr_switches++; |
3736 | rq->curr = next; | |
3737 | ++*switch_count; | |
3738 | ||
dd41f596 | 3739 | context_switch(rq, prev, next); /* unlocks the rq */ |
8f4d37ec PZ |
3740 | /* |
3741 | * the context switch might have flipped the stack from under | |
3742 | * us, hence refresh the local variables. | |
3743 | */ | |
3744 | cpu = smp_processor_id(); | |
3745 | rq = cpu_rq(cpu); | |
1da177e4 | 3746 | } else |
05fa785c | 3747 | raw_spin_unlock_irq(&rq->lock); |
1da177e4 | 3748 | |
3f029d3c | 3749 | post_schedule(rq); |
1da177e4 | 3750 | |
6d558c3a YZ |
3751 | if (unlikely(reacquire_kernel_lock(current) < 0)) { |
3752 | prev = rq->curr; | |
3753 | switch_count = &prev->nivcsw; | |
1da177e4 | 3754 | goto need_resched_nonpreemptible; |
6d558c3a | 3755 | } |
8f4d37ec | 3756 | |
1da177e4 | 3757 | preempt_enable_no_resched(); |
ff743345 | 3758 | if (need_resched()) |
1da177e4 LT |
3759 | goto need_resched; |
3760 | } | |
1da177e4 LT |
3761 | EXPORT_SYMBOL(schedule); |
3762 | ||
c08f7829 | 3763 | #ifdef CONFIG_MUTEX_SPIN_ON_OWNER |
0d66bf6d PZ |
3764 | /* |
3765 | * Look out! "owner" is an entirely speculative pointer | |
3766 | * access and not reliable. | |
3767 | */ | |
3768 | int mutex_spin_on_owner(struct mutex *lock, struct thread_info *owner) | |
3769 | { | |
3770 | unsigned int cpu; | |
3771 | struct rq *rq; | |
3772 | ||
3773 | if (!sched_feat(OWNER_SPIN)) | |
3774 | return 0; | |
3775 | ||
3776 | #ifdef CONFIG_DEBUG_PAGEALLOC | |
3777 | /* | |
3778 | * Need to access the cpu field knowing that | |
3779 | * DEBUG_PAGEALLOC could have unmapped it if | |
3780 | * the mutex owner just released it and exited. | |
3781 | */ | |
3782 | if (probe_kernel_address(&owner->cpu, cpu)) | |
3783 | goto out; | |
3784 | #else | |
3785 | cpu = owner->cpu; | |
3786 | #endif | |
3787 | ||
3788 | /* | |
3789 | * Even if the access succeeded (likely case), | |
3790 | * the cpu field may no longer be valid. | |
3791 | */ | |
3792 | if (cpu >= nr_cpumask_bits) | |
3793 | goto out; | |
3794 | ||
3795 | /* | |
3796 | * We need to validate that we can do a | |
3797 | * get_cpu() and that we have the percpu area. | |
3798 | */ | |
3799 | if (!cpu_online(cpu)) | |
3800 | goto out; | |
3801 | ||
3802 | rq = cpu_rq(cpu); | |
3803 | ||
3804 | for (;;) { | |
3805 | /* | |
3806 | * Owner changed, break to re-assess state. | |
3807 | */ | |
3808 | if (lock->owner != owner) | |
3809 | break; | |
3810 | ||
3811 | /* | |
3812 | * Is that owner really running on that cpu? | |
3813 | */ | |
3814 | if (task_thread_info(rq->curr) != owner || need_resched()) | |
3815 | return 0; | |
3816 | ||
3817 | cpu_relax(); | |
3818 | } | |
3819 | out: | |
3820 | return 1; | |
3821 | } | |
3822 | #endif | |
3823 | ||
1da177e4 LT |
3824 | #ifdef CONFIG_PREEMPT |
3825 | /* | |
2ed6e34f | 3826 | * this is the entry point to schedule() from in-kernel preemption |
41a2d6cf | 3827 | * off of preempt_enable. Kernel preemptions off return from interrupt |
1da177e4 LT |
3828 | * occur there and call schedule directly. |
3829 | */ | |
3830 | asmlinkage void __sched preempt_schedule(void) | |
3831 | { | |
3832 | struct thread_info *ti = current_thread_info(); | |
6478d880 | 3833 | |
1da177e4 LT |
3834 | /* |
3835 | * If there is a non-zero preempt_count or interrupts are disabled, | |
41a2d6cf | 3836 | * we do not want to preempt the current task. Just return.. |
1da177e4 | 3837 | */ |
beed33a8 | 3838 | if (likely(ti->preempt_count || irqs_disabled())) |
1da177e4 LT |
3839 | return; |
3840 | ||
3a5c359a AK |
3841 | do { |
3842 | add_preempt_count(PREEMPT_ACTIVE); | |
3a5c359a | 3843 | schedule(); |
3a5c359a | 3844 | sub_preempt_count(PREEMPT_ACTIVE); |
1da177e4 | 3845 | |
3a5c359a AK |
3846 | /* |
3847 | * Check again in case we missed a preemption opportunity | |
3848 | * between schedule and now. | |
3849 | */ | |
3850 | barrier(); | |
5ed0cec0 | 3851 | } while (need_resched()); |
1da177e4 | 3852 | } |
1da177e4 LT |
3853 | EXPORT_SYMBOL(preempt_schedule); |
3854 | ||
3855 | /* | |
2ed6e34f | 3856 | * this is the entry point to schedule() from kernel preemption |
1da177e4 LT |
3857 | * off of irq context. |
3858 | * Note, that this is called and return with irqs disabled. This will | |
3859 | * protect us against recursive calling from irq. | |
3860 | */ | |
3861 | asmlinkage void __sched preempt_schedule_irq(void) | |
3862 | { | |
3863 | struct thread_info *ti = current_thread_info(); | |
6478d880 | 3864 | |
2ed6e34f | 3865 | /* Catch callers which need to be fixed */ |
1da177e4 LT |
3866 | BUG_ON(ti->preempt_count || !irqs_disabled()); |
3867 | ||
3a5c359a AK |
3868 | do { |
3869 | add_preempt_count(PREEMPT_ACTIVE); | |
3a5c359a AK |
3870 | local_irq_enable(); |
3871 | schedule(); | |
3872 | local_irq_disable(); | |
3a5c359a | 3873 | sub_preempt_count(PREEMPT_ACTIVE); |
1da177e4 | 3874 | |
3a5c359a AK |
3875 | /* |
3876 | * Check again in case we missed a preemption opportunity | |
3877 | * between schedule and now. | |
3878 | */ | |
3879 | barrier(); | |
5ed0cec0 | 3880 | } while (need_resched()); |
1da177e4 LT |
3881 | } |
3882 | ||
3883 | #endif /* CONFIG_PREEMPT */ | |
3884 | ||
63859d4f | 3885 | int default_wake_function(wait_queue_t *curr, unsigned mode, int wake_flags, |
95cdf3b7 | 3886 | void *key) |
1da177e4 | 3887 | { |
63859d4f | 3888 | return try_to_wake_up(curr->private, mode, wake_flags); |
1da177e4 | 3889 | } |
1da177e4 LT |
3890 | EXPORT_SYMBOL(default_wake_function); |
3891 | ||
3892 | /* | |
41a2d6cf IM |
3893 | * The core wakeup function. Non-exclusive wakeups (nr_exclusive == 0) just |
3894 | * wake everything up. If it's an exclusive wakeup (nr_exclusive == small +ve | |
1da177e4 LT |
3895 | * number) then we wake all the non-exclusive tasks and one exclusive task. |
3896 | * | |
3897 | * There are circumstances in which we can try to wake a task which has already | |
41a2d6cf | 3898 | * started to run but is not in state TASK_RUNNING. try_to_wake_up() returns |
1da177e4 LT |
3899 | * zero in this (rare) case, and we handle it by continuing to scan the queue. |
3900 | */ | |
78ddb08f | 3901 | static void __wake_up_common(wait_queue_head_t *q, unsigned int mode, |
63859d4f | 3902 | int nr_exclusive, int wake_flags, void *key) |
1da177e4 | 3903 | { |
2e45874c | 3904 | wait_queue_t *curr, *next; |
1da177e4 | 3905 | |
2e45874c | 3906 | list_for_each_entry_safe(curr, next, &q->task_list, task_list) { |
48f24c4d IM |
3907 | unsigned flags = curr->flags; |
3908 | ||
63859d4f | 3909 | if (curr->func(curr, mode, wake_flags, key) && |
48f24c4d | 3910 | (flags & WQ_FLAG_EXCLUSIVE) && !--nr_exclusive) |
1da177e4 LT |
3911 | break; |
3912 | } | |
3913 | } | |
3914 | ||
3915 | /** | |
3916 | * __wake_up - wake up threads blocked on a waitqueue. | |
3917 | * @q: the waitqueue | |
3918 | * @mode: which threads | |
3919 | * @nr_exclusive: how many wake-one or wake-many threads to wake up | |
67be2dd1 | 3920 | * @key: is directly passed to the wakeup function |
50fa610a DH |
3921 | * |
3922 | * It may be assumed that this function implies a write memory barrier before | |
3923 | * changing the task state if and only if any tasks are woken up. | |
1da177e4 | 3924 | */ |
7ad5b3a5 | 3925 | void __wake_up(wait_queue_head_t *q, unsigned int mode, |
95cdf3b7 | 3926 | int nr_exclusive, void *key) |
1da177e4 LT |
3927 | { |
3928 | unsigned long flags; | |
3929 | ||
3930 | spin_lock_irqsave(&q->lock, flags); | |
3931 | __wake_up_common(q, mode, nr_exclusive, 0, key); | |
3932 | spin_unlock_irqrestore(&q->lock, flags); | |
3933 | } | |
1da177e4 LT |
3934 | EXPORT_SYMBOL(__wake_up); |
3935 | ||
3936 | /* | |
3937 | * Same as __wake_up but called with the spinlock in wait_queue_head_t held. | |
3938 | */ | |
7ad5b3a5 | 3939 | void __wake_up_locked(wait_queue_head_t *q, unsigned int mode) |
1da177e4 LT |
3940 | { |
3941 | __wake_up_common(q, mode, 1, 0, NULL); | |
3942 | } | |
3943 | ||
4ede816a DL |
3944 | void __wake_up_locked_key(wait_queue_head_t *q, unsigned int mode, void *key) |
3945 | { | |
3946 | __wake_up_common(q, mode, 1, 0, key); | |
3947 | } | |
3948 | ||
1da177e4 | 3949 | /** |
4ede816a | 3950 | * __wake_up_sync_key - wake up threads blocked on a waitqueue. |
1da177e4 LT |
3951 | * @q: the waitqueue |
3952 | * @mode: which threads | |
3953 | * @nr_exclusive: how many wake-one or wake-many threads to wake up | |
4ede816a | 3954 | * @key: opaque value to be passed to wakeup targets |
1da177e4 LT |
3955 | * |
3956 | * The sync wakeup differs that the waker knows that it will schedule | |
3957 | * away soon, so while the target thread will be woken up, it will not | |
3958 | * be migrated to another CPU - ie. the two threads are 'synchronized' | |
3959 | * with each other. This can prevent needless bouncing between CPUs. | |
3960 | * | |
3961 | * On UP it can prevent extra preemption. | |
50fa610a DH |
3962 | * |
3963 | * It may be assumed that this function implies a write memory barrier before | |
3964 | * changing the task state if and only if any tasks are woken up. | |
1da177e4 | 3965 | */ |
4ede816a DL |
3966 | void __wake_up_sync_key(wait_queue_head_t *q, unsigned int mode, |
3967 | int nr_exclusive, void *key) | |
1da177e4 LT |
3968 | { |
3969 | unsigned long flags; | |
7d478721 | 3970 | int wake_flags = WF_SYNC; |
1da177e4 LT |
3971 | |
3972 | if (unlikely(!q)) | |
3973 | return; | |
3974 | ||
3975 | if (unlikely(!nr_exclusive)) | |
7d478721 | 3976 | wake_flags = 0; |
1da177e4 LT |
3977 | |
3978 | spin_lock_irqsave(&q->lock, flags); | |
7d478721 | 3979 | __wake_up_common(q, mode, nr_exclusive, wake_flags, key); |
1da177e4 LT |
3980 | spin_unlock_irqrestore(&q->lock, flags); |
3981 | } | |
4ede816a DL |
3982 | EXPORT_SYMBOL_GPL(__wake_up_sync_key); |
3983 | ||
3984 | /* | |
3985 | * __wake_up_sync - see __wake_up_sync_key() | |
3986 | */ | |
3987 | void __wake_up_sync(wait_queue_head_t *q, unsigned int mode, int nr_exclusive) | |
3988 | { | |
3989 | __wake_up_sync_key(q, mode, nr_exclusive, NULL); | |
3990 | } | |
1da177e4 LT |
3991 | EXPORT_SYMBOL_GPL(__wake_up_sync); /* For internal use only */ |
3992 | ||
65eb3dc6 KD |
3993 | /** |
3994 | * complete: - signals a single thread waiting on this completion | |
3995 | * @x: holds the state of this particular completion | |
3996 | * | |
3997 | * This will wake up a single thread waiting on this completion. Threads will be | |
3998 | * awakened in the same order in which they were queued. | |
3999 | * | |
4000 | * See also complete_all(), wait_for_completion() and related routines. | |
50fa610a DH |
4001 | * |
4002 | * It may be assumed that this function implies a write memory barrier before | |
4003 | * changing the task state if and only if any tasks are woken up. | |
65eb3dc6 | 4004 | */ |
b15136e9 | 4005 | void complete(struct completion *x) |
1da177e4 LT |
4006 | { |
4007 | unsigned long flags; | |
4008 | ||
4009 | spin_lock_irqsave(&x->wait.lock, flags); | |
4010 | x->done++; | |
d9514f6c | 4011 | __wake_up_common(&x->wait, TASK_NORMAL, 1, 0, NULL); |
1da177e4 LT |
4012 | spin_unlock_irqrestore(&x->wait.lock, flags); |
4013 | } | |
4014 | EXPORT_SYMBOL(complete); | |
4015 | ||
65eb3dc6 KD |
4016 | /** |
4017 | * complete_all: - signals all threads waiting on this completion | |
4018 | * @x: holds the state of this particular completion | |
4019 | * | |
4020 | * This will wake up all threads waiting on this particular completion event. | |
50fa610a DH |
4021 | * |
4022 | * It may be assumed that this function implies a write memory barrier before | |
4023 | * changing the task state if and only if any tasks are woken up. | |
65eb3dc6 | 4024 | */ |
b15136e9 | 4025 | void complete_all(struct completion *x) |
1da177e4 LT |
4026 | { |
4027 | unsigned long flags; | |
4028 | ||
4029 | spin_lock_irqsave(&x->wait.lock, flags); | |
4030 | x->done += UINT_MAX/2; | |
d9514f6c | 4031 | __wake_up_common(&x->wait, TASK_NORMAL, 0, 0, NULL); |
1da177e4 LT |
4032 | spin_unlock_irqrestore(&x->wait.lock, flags); |
4033 | } | |
4034 | EXPORT_SYMBOL(complete_all); | |
4035 | ||
8cbbe86d AK |
4036 | static inline long __sched |
4037 | do_wait_for_common(struct completion *x, long timeout, int state) | |
1da177e4 | 4038 | { |
1da177e4 LT |
4039 | if (!x->done) { |
4040 | DECLARE_WAITQUEUE(wait, current); | |
4041 | ||
4042 | wait.flags |= WQ_FLAG_EXCLUSIVE; | |
4043 | __add_wait_queue_tail(&x->wait, &wait); | |
4044 | do { | |
94d3d824 | 4045 | if (signal_pending_state(state, current)) { |
ea71a546 ON |
4046 | timeout = -ERESTARTSYS; |
4047 | break; | |
8cbbe86d AK |
4048 | } |
4049 | __set_current_state(state); | |
1da177e4 LT |
4050 | spin_unlock_irq(&x->wait.lock); |
4051 | timeout = schedule_timeout(timeout); | |
4052 | spin_lock_irq(&x->wait.lock); | |
ea71a546 | 4053 | } while (!x->done && timeout); |
1da177e4 | 4054 | __remove_wait_queue(&x->wait, &wait); |
ea71a546 ON |
4055 | if (!x->done) |
4056 | return timeout; | |
1da177e4 LT |
4057 | } |
4058 | x->done--; | |
ea71a546 | 4059 | return timeout ?: 1; |
1da177e4 | 4060 | } |
1da177e4 | 4061 | |
8cbbe86d AK |
4062 | static long __sched |
4063 | wait_for_common(struct completion *x, long timeout, int state) | |
1da177e4 | 4064 | { |
1da177e4 LT |
4065 | might_sleep(); |
4066 | ||
4067 | spin_lock_irq(&x->wait.lock); | |
8cbbe86d | 4068 | timeout = do_wait_for_common(x, timeout, state); |
1da177e4 | 4069 | spin_unlock_irq(&x->wait.lock); |
8cbbe86d AK |
4070 | return timeout; |
4071 | } | |
1da177e4 | 4072 | |
65eb3dc6 KD |
4073 | /** |
4074 | * wait_for_completion: - waits for completion of a task | |
4075 | * @x: holds the state of this particular completion | |
4076 | * | |
4077 | * This waits to be signaled for completion of a specific task. It is NOT | |
4078 | * interruptible and there is no timeout. | |
4079 | * | |
4080 | * See also similar routines (i.e. wait_for_completion_timeout()) with timeout | |
4081 | * and interrupt capability. Also see complete(). | |
4082 | */ | |
b15136e9 | 4083 | void __sched wait_for_completion(struct completion *x) |
8cbbe86d AK |
4084 | { |
4085 | wait_for_common(x, MAX_SCHEDULE_TIMEOUT, TASK_UNINTERRUPTIBLE); | |
1da177e4 | 4086 | } |
8cbbe86d | 4087 | EXPORT_SYMBOL(wait_for_completion); |
1da177e4 | 4088 | |
65eb3dc6 KD |
4089 | /** |
4090 | * wait_for_completion_timeout: - waits for completion of a task (w/timeout) | |
4091 | * @x: holds the state of this particular completion | |
4092 | * @timeout: timeout value in jiffies | |
4093 | * | |
4094 | * This waits for either a completion of a specific task to be signaled or for a | |
4095 | * specified timeout to expire. The timeout is in jiffies. It is not | |
4096 | * interruptible. | |
4097 | */ | |
b15136e9 | 4098 | unsigned long __sched |
8cbbe86d | 4099 | wait_for_completion_timeout(struct completion *x, unsigned long timeout) |
1da177e4 | 4100 | { |
8cbbe86d | 4101 | return wait_for_common(x, timeout, TASK_UNINTERRUPTIBLE); |
1da177e4 | 4102 | } |
8cbbe86d | 4103 | EXPORT_SYMBOL(wait_for_completion_timeout); |
1da177e4 | 4104 | |
65eb3dc6 KD |
4105 | /** |
4106 | * wait_for_completion_interruptible: - waits for completion of a task (w/intr) | |
4107 | * @x: holds the state of this particular completion | |
4108 | * | |
4109 | * This waits for completion of a specific task to be signaled. It is | |
4110 | * interruptible. | |
4111 | */ | |
8cbbe86d | 4112 | int __sched wait_for_completion_interruptible(struct completion *x) |
0fec171c | 4113 | { |
51e97990 AK |
4114 | long t = wait_for_common(x, MAX_SCHEDULE_TIMEOUT, TASK_INTERRUPTIBLE); |
4115 | if (t == -ERESTARTSYS) | |
4116 | return t; | |
4117 | return 0; | |
0fec171c | 4118 | } |
8cbbe86d | 4119 | EXPORT_SYMBOL(wait_for_completion_interruptible); |
1da177e4 | 4120 | |
65eb3dc6 KD |
4121 | /** |
4122 | * wait_for_completion_interruptible_timeout: - waits for completion (w/(to,intr)) | |
4123 | * @x: holds the state of this particular completion | |
4124 | * @timeout: timeout value in jiffies | |
4125 | * | |
4126 | * This waits for either a completion of a specific task to be signaled or for a | |
4127 | * specified timeout to expire. It is interruptible. The timeout is in jiffies. | |
4128 | */ | |
b15136e9 | 4129 | unsigned long __sched |
8cbbe86d AK |
4130 | wait_for_completion_interruptible_timeout(struct completion *x, |
4131 | unsigned long timeout) | |
0fec171c | 4132 | { |
8cbbe86d | 4133 | return wait_for_common(x, timeout, TASK_INTERRUPTIBLE); |
0fec171c | 4134 | } |
8cbbe86d | 4135 | EXPORT_SYMBOL(wait_for_completion_interruptible_timeout); |
1da177e4 | 4136 | |
65eb3dc6 KD |
4137 | /** |
4138 | * wait_for_completion_killable: - waits for completion of a task (killable) | |
4139 | * @x: holds the state of this particular completion | |
4140 | * | |
4141 | * This waits to be signaled for completion of a specific task. It can be | |
4142 | * interrupted by a kill signal. | |
4143 | */ | |
009e577e MW |
4144 | int __sched wait_for_completion_killable(struct completion *x) |
4145 | { | |
4146 | long t = wait_for_common(x, MAX_SCHEDULE_TIMEOUT, TASK_KILLABLE); | |
4147 | if (t == -ERESTARTSYS) | |
4148 | return t; | |
4149 | return 0; | |
4150 | } | |
4151 | EXPORT_SYMBOL(wait_for_completion_killable); | |
4152 | ||
be4de352 DC |
4153 | /** |
4154 | * try_wait_for_completion - try to decrement a completion without blocking | |
4155 | * @x: completion structure | |
4156 | * | |
4157 | * Returns: 0 if a decrement cannot be done without blocking | |
4158 | * 1 if a decrement succeeded. | |
4159 | * | |
4160 | * If a completion is being used as a counting completion, | |
4161 | * attempt to decrement the counter without blocking. This | |
4162 | * enables us to avoid waiting if the resource the completion | |
4163 | * is protecting is not available. | |
4164 | */ | |
4165 | bool try_wait_for_completion(struct completion *x) | |
4166 | { | |
7539a3b3 | 4167 | unsigned long flags; |
be4de352 DC |
4168 | int ret = 1; |
4169 | ||
7539a3b3 | 4170 | spin_lock_irqsave(&x->wait.lock, flags); |
be4de352 DC |
4171 | if (!x->done) |
4172 | ret = 0; | |
4173 | else | |
4174 | x->done--; | |
7539a3b3 | 4175 | spin_unlock_irqrestore(&x->wait.lock, flags); |
be4de352 DC |
4176 | return ret; |
4177 | } | |
4178 | EXPORT_SYMBOL(try_wait_for_completion); | |
4179 | ||
4180 | /** | |
4181 | * completion_done - Test to see if a completion has any waiters | |
4182 | * @x: completion structure | |
4183 | * | |
4184 | * Returns: 0 if there are waiters (wait_for_completion() in progress) | |
4185 | * 1 if there are no waiters. | |
4186 | * | |
4187 | */ | |
4188 | bool completion_done(struct completion *x) | |
4189 | { | |
7539a3b3 | 4190 | unsigned long flags; |
be4de352 DC |
4191 | int ret = 1; |
4192 | ||
7539a3b3 | 4193 | spin_lock_irqsave(&x->wait.lock, flags); |
be4de352 DC |
4194 | if (!x->done) |
4195 | ret = 0; | |
7539a3b3 | 4196 | spin_unlock_irqrestore(&x->wait.lock, flags); |
be4de352 DC |
4197 | return ret; |
4198 | } | |
4199 | EXPORT_SYMBOL(completion_done); | |
4200 | ||
8cbbe86d AK |
4201 | static long __sched |
4202 | sleep_on_common(wait_queue_head_t *q, int state, long timeout) | |
1da177e4 | 4203 | { |
0fec171c IM |
4204 | unsigned long flags; |
4205 | wait_queue_t wait; | |
4206 | ||
4207 | init_waitqueue_entry(&wait, current); | |
1da177e4 | 4208 | |
8cbbe86d | 4209 | __set_current_state(state); |
1da177e4 | 4210 | |
8cbbe86d AK |
4211 | spin_lock_irqsave(&q->lock, flags); |
4212 | __add_wait_queue(q, &wait); | |
4213 | spin_unlock(&q->lock); | |
4214 | timeout = schedule_timeout(timeout); | |
4215 | spin_lock_irq(&q->lock); | |
4216 | __remove_wait_queue(q, &wait); | |
4217 | spin_unlock_irqrestore(&q->lock, flags); | |
4218 | ||
4219 | return timeout; | |
4220 | } | |
4221 | ||
4222 | void __sched interruptible_sleep_on(wait_queue_head_t *q) | |
4223 | { | |
4224 | sleep_on_common(q, TASK_INTERRUPTIBLE, MAX_SCHEDULE_TIMEOUT); | |
1da177e4 | 4225 | } |
1da177e4 LT |
4226 | EXPORT_SYMBOL(interruptible_sleep_on); |
4227 | ||
0fec171c | 4228 | long __sched |
95cdf3b7 | 4229 | interruptible_sleep_on_timeout(wait_queue_head_t *q, long timeout) |
1da177e4 | 4230 | { |
8cbbe86d | 4231 | return sleep_on_common(q, TASK_INTERRUPTIBLE, timeout); |
1da177e4 | 4232 | } |
1da177e4 LT |
4233 | EXPORT_SYMBOL(interruptible_sleep_on_timeout); |
4234 | ||
0fec171c | 4235 | void __sched sleep_on(wait_queue_head_t *q) |
1da177e4 | 4236 | { |
8cbbe86d | 4237 | sleep_on_common(q, TASK_UNINTERRUPTIBLE, MAX_SCHEDULE_TIMEOUT); |
1da177e4 | 4238 | } |
1da177e4 LT |
4239 | EXPORT_SYMBOL(sleep_on); |
4240 | ||
0fec171c | 4241 | long __sched sleep_on_timeout(wait_queue_head_t *q, long timeout) |
1da177e4 | 4242 | { |
8cbbe86d | 4243 | return sleep_on_common(q, TASK_UNINTERRUPTIBLE, timeout); |
1da177e4 | 4244 | } |
1da177e4 LT |
4245 | EXPORT_SYMBOL(sleep_on_timeout); |
4246 | ||
b29739f9 IM |
4247 | #ifdef CONFIG_RT_MUTEXES |
4248 | ||
4249 | /* | |
4250 | * rt_mutex_setprio - set the current priority of a task | |
4251 | * @p: task | |
4252 | * @prio: prio value (kernel-internal form) | |
4253 | * | |
4254 | * This function changes the 'effective' priority of a task. It does | |
4255 | * not touch ->normal_prio like __setscheduler(). | |
4256 | * | |
4257 | * Used by the rt_mutex code to implement priority inheritance logic. | |
4258 | */ | |
36c8b586 | 4259 | void rt_mutex_setprio(struct task_struct *p, int prio) |
b29739f9 IM |
4260 | { |
4261 | unsigned long flags; | |
83b699ed | 4262 | int oldprio, on_rq, running; |
70b97a7f | 4263 | struct rq *rq; |
83ab0aa0 | 4264 | const struct sched_class *prev_class; |
b29739f9 IM |
4265 | |
4266 | BUG_ON(prio < 0 || prio > MAX_PRIO); | |
4267 | ||
4268 | rq = task_rq_lock(p, &flags); | |
a8e504d2 | 4269 | update_rq_clock(rq); |
b29739f9 | 4270 | |
d5f9f942 | 4271 | oldprio = p->prio; |
83ab0aa0 | 4272 | prev_class = p->sched_class; |
dd41f596 | 4273 | on_rq = p->se.on_rq; |
051a1d1a | 4274 | running = task_current(rq, p); |
0e1f3483 | 4275 | if (on_rq) |
69be72c1 | 4276 | dequeue_task(rq, p, 0); |
0e1f3483 HS |
4277 | if (running) |
4278 | p->sched_class->put_prev_task(rq, p); | |
dd41f596 IM |
4279 | |
4280 | if (rt_prio(prio)) | |
4281 | p->sched_class = &rt_sched_class; | |
4282 | else | |
4283 | p->sched_class = &fair_sched_class; | |
4284 | ||
b29739f9 IM |
4285 | p->prio = prio; |
4286 | ||
0e1f3483 HS |
4287 | if (running) |
4288 | p->sched_class->set_curr_task(rq); | |
dd41f596 | 4289 | if (on_rq) { |
60db48ca | 4290 | enqueue_task(rq, p, 0, oldprio < prio); |
cb469845 SR |
4291 | |
4292 | check_class_changed(rq, p, prev_class, oldprio, running); | |
b29739f9 IM |
4293 | } |
4294 | task_rq_unlock(rq, &flags); | |
4295 | } | |
4296 | ||
4297 | #endif | |
4298 | ||
36c8b586 | 4299 | void set_user_nice(struct task_struct *p, long nice) |
1da177e4 | 4300 | { |
dd41f596 | 4301 | int old_prio, delta, on_rq; |
1da177e4 | 4302 | unsigned long flags; |
70b97a7f | 4303 | struct rq *rq; |
1da177e4 LT |
4304 | |
4305 | if (TASK_NICE(p) == nice || nice < -20 || nice > 19) | |
4306 | return; | |
4307 | /* | |
4308 | * We have to be careful, if called from sys_setpriority(), | |
4309 | * the task might be in the middle of scheduling on another CPU. | |
4310 | */ | |
4311 | rq = task_rq_lock(p, &flags); | |
a8e504d2 | 4312 | update_rq_clock(rq); |
1da177e4 LT |
4313 | /* |
4314 | * The RT priorities are set via sched_setscheduler(), but we still | |
4315 | * allow the 'normal' nice value to be set - but as expected | |
4316 | * it wont have any effect on scheduling until the task is | |
dd41f596 | 4317 | * SCHED_FIFO/SCHED_RR: |
1da177e4 | 4318 | */ |
e05606d3 | 4319 | if (task_has_rt_policy(p)) { |
1da177e4 LT |
4320 | p->static_prio = NICE_TO_PRIO(nice); |
4321 | goto out_unlock; | |
4322 | } | |
dd41f596 | 4323 | on_rq = p->se.on_rq; |
c09595f6 | 4324 | if (on_rq) |
69be72c1 | 4325 | dequeue_task(rq, p, 0); |
1da177e4 | 4326 | |
1da177e4 | 4327 | p->static_prio = NICE_TO_PRIO(nice); |
2dd73a4f | 4328 | set_load_weight(p); |
b29739f9 IM |
4329 | old_prio = p->prio; |
4330 | p->prio = effective_prio(p); | |
4331 | delta = p->prio - old_prio; | |
1da177e4 | 4332 | |
dd41f596 | 4333 | if (on_rq) { |
ea87bb78 | 4334 | enqueue_task(rq, p, 0, false); |
1da177e4 | 4335 | /* |
d5f9f942 AM |
4336 | * If the task increased its priority or is running and |
4337 | * lowered its priority, then reschedule its CPU: | |
1da177e4 | 4338 | */ |
d5f9f942 | 4339 | if (delta < 0 || (delta > 0 && task_running(rq, p))) |
1da177e4 LT |
4340 | resched_task(rq->curr); |
4341 | } | |
4342 | out_unlock: | |
4343 | task_rq_unlock(rq, &flags); | |
4344 | } | |
1da177e4 LT |
4345 | EXPORT_SYMBOL(set_user_nice); |
4346 | ||
e43379f1 MM |
4347 | /* |
4348 | * can_nice - check if a task can reduce its nice value | |
4349 | * @p: task | |
4350 | * @nice: nice value | |
4351 | */ | |
36c8b586 | 4352 | int can_nice(const struct task_struct *p, const int nice) |
e43379f1 | 4353 | { |
024f4747 MM |
4354 | /* convert nice value [19,-20] to rlimit style value [1,40] */ |
4355 | int nice_rlim = 20 - nice; | |
48f24c4d | 4356 | |
78d7d407 | 4357 | return (nice_rlim <= task_rlimit(p, RLIMIT_NICE) || |
e43379f1 MM |
4358 | capable(CAP_SYS_NICE)); |
4359 | } | |
4360 | ||
1da177e4 LT |
4361 | #ifdef __ARCH_WANT_SYS_NICE |
4362 | ||
4363 | /* | |
4364 | * sys_nice - change the priority of the current process. | |
4365 | * @increment: priority increment | |
4366 | * | |
4367 | * sys_setpriority is a more generic, but much slower function that | |
4368 | * does similar things. | |
4369 | */ | |
5add95d4 | 4370 | SYSCALL_DEFINE1(nice, int, increment) |
1da177e4 | 4371 | { |
48f24c4d | 4372 | long nice, retval; |
1da177e4 LT |
4373 | |
4374 | /* | |
4375 | * Setpriority might change our priority at the same moment. | |
4376 | * We don't have to worry. Conceptually one call occurs first | |
4377 | * and we have a single winner. | |
4378 | */ | |
e43379f1 MM |
4379 | if (increment < -40) |
4380 | increment = -40; | |
1da177e4 LT |
4381 | if (increment > 40) |
4382 | increment = 40; | |
4383 | ||
2b8f836f | 4384 | nice = TASK_NICE(current) + increment; |
1da177e4 LT |
4385 | if (nice < -20) |
4386 | nice = -20; | |
4387 | if (nice > 19) | |
4388 | nice = 19; | |
4389 | ||
e43379f1 MM |
4390 | if (increment < 0 && !can_nice(current, nice)) |
4391 | return -EPERM; | |
4392 | ||
1da177e4 LT |
4393 | retval = security_task_setnice(current, nice); |
4394 | if (retval) | |
4395 | return retval; | |
4396 | ||
4397 | set_user_nice(current, nice); | |
4398 | return 0; | |
4399 | } | |
4400 | ||
4401 | #endif | |
4402 | ||
4403 | /** | |
4404 | * task_prio - return the priority value of a given task. | |
4405 | * @p: the task in question. | |
4406 | * | |
4407 | * This is the priority value as seen by users in /proc. | |
4408 | * RT tasks are offset by -200. Normal tasks are centered | |
4409 | * around 0, value goes from -16 to +15. | |
4410 | */ | |
36c8b586 | 4411 | int task_prio(const struct task_struct *p) |
1da177e4 LT |
4412 | { |
4413 | return p->prio - MAX_RT_PRIO; | |
4414 | } | |
4415 | ||
4416 | /** | |
4417 | * task_nice - return the nice value of a given task. | |
4418 | * @p: the task in question. | |
4419 | */ | |
36c8b586 | 4420 | int task_nice(const struct task_struct *p) |
1da177e4 LT |
4421 | { |
4422 | return TASK_NICE(p); | |
4423 | } | |
150d8bed | 4424 | EXPORT_SYMBOL(task_nice); |
1da177e4 LT |
4425 | |
4426 | /** | |
4427 | * idle_cpu - is a given cpu idle currently? | |
4428 | * @cpu: the processor in question. | |
4429 | */ | |
4430 | int idle_cpu(int cpu) | |
4431 | { | |
4432 | return cpu_curr(cpu) == cpu_rq(cpu)->idle; | |
4433 | } | |
4434 | ||
1da177e4 LT |
4435 | /** |
4436 | * idle_task - return the idle task for a given cpu. | |
4437 | * @cpu: the processor in question. | |
4438 | */ | |
36c8b586 | 4439 | struct task_struct *idle_task(int cpu) |
1da177e4 LT |
4440 | { |
4441 | return cpu_rq(cpu)->idle; | |
4442 | } | |
4443 | ||
4444 | /** | |
4445 | * find_process_by_pid - find a process with a matching PID value. | |
4446 | * @pid: the pid in question. | |
4447 | */ | |
a9957449 | 4448 | static struct task_struct *find_process_by_pid(pid_t pid) |
1da177e4 | 4449 | { |
228ebcbe | 4450 | return pid ? find_task_by_vpid(pid) : current; |
1da177e4 LT |
4451 | } |
4452 | ||
4453 | /* Actually do priority change: must hold rq lock. */ | |
dd41f596 IM |
4454 | static void |
4455 | __setscheduler(struct rq *rq, struct task_struct *p, int policy, int prio) | |
1da177e4 | 4456 | { |
dd41f596 | 4457 | BUG_ON(p->se.on_rq); |
48f24c4d | 4458 | |
1da177e4 LT |
4459 | p->policy = policy; |
4460 | p->rt_priority = prio; | |
b29739f9 IM |
4461 | p->normal_prio = normal_prio(p); |
4462 | /* we are holding p->pi_lock already */ | |
4463 | p->prio = rt_mutex_getprio(p); | |
ffd44db5 PZ |
4464 | if (rt_prio(p->prio)) |
4465 | p->sched_class = &rt_sched_class; | |
4466 | else | |
4467 | p->sched_class = &fair_sched_class; | |
2dd73a4f | 4468 | set_load_weight(p); |
1da177e4 LT |
4469 | } |
4470 | ||
c69e8d9c DH |
4471 | /* |
4472 | * check the target process has a UID that matches the current process's | |
4473 | */ | |
4474 | static bool check_same_owner(struct task_struct *p) | |
4475 | { | |
4476 | const struct cred *cred = current_cred(), *pcred; | |
4477 | bool match; | |
4478 | ||
4479 | rcu_read_lock(); | |
4480 | pcred = __task_cred(p); | |
4481 | match = (cred->euid == pcred->euid || | |
4482 | cred->euid == pcred->uid); | |
4483 | rcu_read_unlock(); | |
4484 | return match; | |
4485 | } | |
4486 | ||
961ccddd RR |
4487 | static int __sched_setscheduler(struct task_struct *p, int policy, |
4488 | struct sched_param *param, bool user) | |
1da177e4 | 4489 | { |
83b699ed | 4490 | int retval, oldprio, oldpolicy = -1, on_rq, running; |
1da177e4 | 4491 | unsigned long flags; |
83ab0aa0 | 4492 | const struct sched_class *prev_class; |
70b97a7f | 4493 | struct rq *rq; |
ca94c442 | 4494 | int reset_on_fork; |
1da177e4 | 4495 | |
66e5393a SR |
4496 | /* may grab non-irq protected spin_locks */ |
4497 | BUG_ON(in_interrupt()); | |
1da177e4 LT |
4498 | recheck: |
4499 | /* double check policy once rq lock held */ | |
ca94c442 LP |
4500 | if (policy < 0) { |
4501 | reset_on_fork = p->sched_reset_on_fork; | |
1da177e4 | 4502 | policy = oldpolicy = p->policy; |
ca94c442 LP |
4503 | } else { |
4504 | reset_on_fork = !!(policy & SCHED_RESET_ON_FORK); | |
4505 | policy &= ~SCHED_RESET_ON_FORK; | |
4506 | ||
4507 | if (policy != SCHED_FIFO && policy != SCHED_RR && | |
4508 | policy != SCHED_NORMAL && policy != SCHED_BATCH && | |
4509 | policy != SCHED_IDLE) | |
4510 | return -EINVAL; | |
4511 | } | |
4512 | ||
1da177e4 LT |
4513 | /* |
4514 | * Valid priorities for SCHED_FIFO and SCHED_RR are | |
dd41f596 IM |
4515 | * 1..MAX_USER_RT_PRIO-1, valid priority for SCHED_NORMAL, |
4516 | * SCHED_BATCH and SCHED_IDLE is 0. | |
1da177e4 LT |
4517 | */ |
4518 | if (param->sched_priority < 0 || | |
95cdf3b7 | 4519 | (p->mm && param->sched_priority > MAX_USER_RT_PRIO-1) || |
d46523ea | 4520 | (!p->mm && param->sched_priority > MAX_RT_PRIO-1)) |
1da177e4 | 4521 | return -EINVAL; |
e05606d3 | 4522 | if (rt_policy(policy) != (param->sched_priority != 0)) |
1da177e4 LT |
4523 | return -EINVAL; |
4524 | ||
37e4ab3f OC |
4525 | /* |
4526 | * Allow unprivileged RT tasks to decrease priority: | |
4527 | */ | |
961ccddd | 4528 | if (user && !capable(CAP_SYS_NICE)) { |
e05606d3 | 4529 | if (rt_policy(policy)) { |
8dc3e909 | 4530 | unsigned long rlim_rtprio; |
8dc3e909 ON |
4531 | |
4532 | if (!lock_task_sighand(p, &flags)) | |
4533 | return -ESRCH; | |
78d7d407 | 4534 | rlim_rtprio = task_rlimit(p, RLIMIT_RTPRIO); |
8dc3e909 ON |
4535 | unlock_task_sighand(p, &flags); |
4536 | ||
4537 | /* can't set/change the rt policy */ | |
4538 | if (policy != p->policy && !rlim_rtprio) | |
4539 | return -EPERM; | |
4540 | ||
4541 | /* can't increase priority */ | |
4542 | if (param->sched_priority > p->rt_priority && | |
4543 | param->sched_priority > rlim_rtprio) | |
4544 | return -EPERM; | |
4545 | } | |
dd41f596 IM |
4546 | /* |
4547 | * Like positive nice levels, dont allow tasks to | |
4548 | * move out of SCHED_IDLE either: | |
4549 | */ | |
4550 | if (p->policy == SCHED_IDLE && policy != SCHED_IDLE) | |
4551 | return -EPERM; | |
5fe1d75f | 4552 | |
37e4ab3f | 4553 | /* can't change other user's priorities */ |
c69e8d9c | 4554 | if (!check_same_owner(p)) |
37e4ab3f | 4555 | return -EPERM; |
ca94c442 LP |
4556 | |
4557 | /* Normal users shall not reset the sched_reset_on_fork flag */ | |
4558 | if (p->sched_reset_on_fork && !reset_on_fork) | |
4559 | return -EPERM; | |
37e4ab3f | 4560 | } |
1da177e4 | 4561 | |
725aad24 | 4562 | if (user) { |
b68aa230 | 4563 | #ifdef CONFIG_RT_GROUP_SCHED |
725aad24 JF |
4564 | /* |
4565 | * Do not allow realtime tasks into groups that have no runtime | |
4566 | * assigned. | |
4567 | */ | |
9a7e0b18 PZ |
4568 | if (rt_bandwidth_enabled() && rt_policy(policy) && |
4569 | task_group(p)->rt_bandwidth.rt_runtime == 0) | |
725aad24 | 4570 | return -EPERM; |
b68aa230 PZ |
4571 | #endif |
4572 | ||
725aad24 JF |
4573 | retval = security_task_setscheduler(p, policy, param); |
4574 | if (retval) | |
4575 | return retval; | |
4576 | } | |
4577 | ||
b29739f9 IM |
4578 | /* |
4579 | * make sure no PI-waiters arrive (or leave) while we are | |
4580 | * changing the priority of the task: | |
4581 | */ | |
1d615482 | 4582 | raw_spin_lock_irqsave(&p->pi_lock, flags); |
1da177e4 LT |
4583 | /* |
4584 | * To be able to change p->policy safely, the apropriate | |
4585 | * runqueue lock must be held. | |
4586 | */ | |
b29739f9 | 4587 | rq = __task_rq_lock(p); |
1da177e4 LT |
4588 | /* recheck policy now with rq lock held */ |
4589 | if (unlikely(oldpolicy != -1 && oldpolicy != p->policy)) { | |
4590 | policy = oldpolicy = -1; | |
b29739f9 | 4591 | __task_rq_unlock(rq); |
1d615482 | 4592 | raw_spin_unlock_irqrestore(&p->pi_lock, flags); |
1da177e4 LT |
4593 | goto recheck; |
4594 | } | |
2daa3577 | 4595 | update_rq_clock(rq); |
dd41f596 | 4596 | on_rq = p->se.on_rq; |
051a1d1a | 4597 | running = task_current(rq, p); |
0e1f3483 | 4598 | if (on_rq) |
2e1cb74a | 4599 | deactivate_task(rq, p, 0); |
0e1f3483 HS |
4600 | if (running) |
4601 | p->sched_class->put_prev_task(rq, p); | |
f6b53205 | 4602 | |
ca94c442 LP |
4603 | p->sched_reset_on_fork = reset_on_fork; |
4604 | ||
1da177e4 | 4605 | oldprio = p->prio; |
83ab0aa0 | 4606 | prev_class = p->sched_class; |
dd41f596 | 4607 | __setscheduler(rq, p, policy, param->sched_priority); |
f6b53205 | 4608 | |
0e1f3483 HS |
4609 | if (running) |
4610 | p->sched_class->set_curr_task(rq); | |
dd41f596 IM |
4611 | if (on_rq) { |
4612 | activate_task(rq, p, 0); | |
cb469845 SR |
4613 | |
4614 | check_class_changed(rq, p, prev_class, oldprio, running); | |
1da177e4 | 4615 | } |
b29739f9 | 4616 | __task_rq_unlock(rq); |
1d615482 | 4617 | raw_spin_unlock_irqrestore(&p->pi_lock, flags); |
b29739f9 | 4618 | |
95e02ca9 TG |
4619 | rt_mutex_adjust_pi(p); |
4620 | ||
1da177e4 LT |
4621 | return 0; |
4622 | } | |
961ccddd RR |
4623 | |
4624 | /** | |
4625 | * sched_setscheduler - change the scheduling policy and/or RT priority of a thread. | |
4626 | * @p: the task in question. | |
4627 | * @policy: new policy. | |
4628 | * @param: structure containing the new RT priority. | |
4629 | * | |
4630 | * NOTE that the task may be already dead. | |
4631 | */ | |
4632 | int sched_setscheduler(struct task_struct *p, int policy, | |
4633 | struct sched_param *param) | |
4634 | { | |
4635 | return __sched_setscheduler(p, policy, param, true); | |
4636 | } | |
1da177e4 LT |
4637 | EXPORT_SYMBOL_GPL(sched_setscheduler); |
4638 | ||
961ccddd RR |
4639 | /** |
4640 | * sched_setscheduler_nocheck - change the scheduling policy and/or RT priority of a thread from kernelspace. | |
4641 | * @p: the task in question. | |
4642 | * @policy: new policy. | |
4643 | * @param: structure containing the new RT priority. | |
4644 | * | |
4645 | * Just like sched_setscheduler, only don't bother checking if the | |
4646 | * current context has permission. For example, this is needed in | |
4647 | * stop_machine(): we create temporary high priority worker threads, | |
4648 | * but our caller might not have that capability. | |
4649 | */ | |
4650 | int sched_setscheduler_nocheck(struct task_struct *p, int policy, | |
4651 | struct sched_param *param) | |
4652 | { | |
4653 | return __sched_setscheduler(p, policy, param, false); | |
4654 | } | |
4655 | ||
95cdf3b7 IM |
4656 | static int |
4657 | do_sched_setscheduler(pid_t pid, int policy, struct sched_param __user *param) | |
1da177e4 | 4658 | { |
1da177e4 LT |
4659 | struct sched_param lparam; |
4660 | struct task_struct *p; | |
36c8b586 | 4661 | int retval; |
1da177e4 LT |
4662 | |
4663 | if (!param || pid < 0) | |
4664 | return -EINVAL; | |
4665 | if (copy_from_user(&lparam, param, sizeof(struct sched_param))) | |
4666 | return -EFAULT; | |
5fe1d75f ON |
4667 | |
4668 | rcu_read_lock(); | |
4669 | retval = -ESRCH; | |
1da177e4 | 4670 | p = find_process_by_pid(pid); |
5fe1d75f ON |
4671 | if (p != NULL) |
4672 | retval = sched_setscheduler(p, policy, &lparam); | |
4673 | rcu_read_unlock(); | |
36c8b586 | 4674 | |
1da177e4 LT |
4675 | return retval; |
4676 | } | |
4677 | ||
4678 | /** | |
4679 | * sys_sched_setscheduler - set/change the scheduler policy and RT priority | |
4680 | * @pid: the pid in question. | |
4681 | * @policy: new policy. | |
4682 | * @param: structure containing the new RT priority. | |
4683 | */ | |
5add95d4 HC |
4684 | SYSCALL_DEFINE3(sched_setscheduler, pid_t, pid, int, policy, |
4685 | struct sched_param __user *, param) | |
1da177e4 | 4686 | { |
c21761f1 JB |
4687 | /* negative values for policy are not valid */ |
4688 | if (policy < 0) | |
4689 | return -EINVAL; | |
4690 | ||
1da177e4 LT |
4691 | return do_sched_setscheduler(pid, policy, param); |
4692 | } | |
4693 | ||
4694 | /** | |
4695 | * sys_sched_setparam - set/change the RT priority of a thread | |
4696 | * @pid: the pid in question. | |
4697 | * @param: structure containing the new RT priority. | |
4698 | */ | |
5add95d4 | 4699 | SYSCALL_DEFINE2(sched_setparam, pid_t, pid, struct sched_param __user *, param) |
1da177e4 LT |
4700 | { |
4701 | return do_sched_setscheduler(pid, -1, param); | |
4702 | } | |
4703 | ||
4704 | /** | |
4705 | * sys_sched_getscheduler - get the policy (scheduling class) of a thread | |
4706 | * @pid: the pid in question. | |
4707 | */ | |
5add95d4 | 4708 | SYSCALL_DEFINE1(sched_getscheduler, pid_t, pid) |
1da177e4 | 4709 | { |
36c8b586 | 4710 | struct task_struct *p; |
3a5c359a | 4711 | int retval; |
1da177e4 LT |
4712 | |
4713 | if (pid < 0) | |
3a5c359a | 4714 | return -EINVAL; |
1da177e4 LT |
4715 | |
4716 | retval = -ESRCH; | |
5fe85be0 | 4717 | rcu_read_lock(); |
1da177e4 LT |
4718 | p = find_process_by_pid(pid); |
4719 | if (p) { | |
4720 | retval = security_task_getscheduler(p); | |
4721 | if (!retval) | |
ca94c442 LP |
4722 | retval = p->policy |
4723 | | (p->sched_reset_on_fork ? SCHED_RESET_ON_FORK : 0); | |
1da177e4 | 4724 | } |
5fe85be0 | 4725 | rcu_read_unlock(); |
1da177e4 LT |
4726 | return retval; |
4727 | } | |
4728 | ||
4729 | /** | |
ca94c442 | 4730 | * sys_sched_getparam - get the RT priority of a thread |
1da177e4 LT |
4731 | * @pid: the pid in question. |
4732 | * @param: structure containing the RT priority. | |
4733 | */ | |
5add95d4 | 4734 | SYSCALL_DEFINE2(sched_getparam, pid_t, pid, struct sched_param __user *, param) |
1da177e4 LT |
4735 | { |
4736 | struct sched_param lp; | |
36c8b586 | 4737 | struct task_struct *p; |
3a5c359a | 4738 | int retval; |
1da177e4 LT |
4739 | |
4740 | if (!param || pid < 0) | |
3a5c359a | 4741 | return -EINVAL; |
1da177e4 | 4742 | |
5fe85be0 | 4743 | rcu_read_lock(); |
1da177e4 LT |
4744 | p = find_process_by_pid(pid); |
4745 | retval = -ESRCH; | |
4746 | if (!p) | |
4747 | goto out_unlock; | |
4748 | ||
4749 | retval = security_task_getscheduler(p); | |
4750 | if (retval) | |
4751 | goto out_unlock; | |
4752 | ||
4753 | lp.sched_priority = p->rt_priority; | |
5fe85be0 | 4754 | rcu_read_unlock(); |
1da177e4 LT |
4755 | |
4756 | /* | |
4757 | * This one might sleep, we cannot do it with a spinlock held ... | |
4758 | */ | |
4759 | retval = copy_to_user(param, &lp, sizeof(*param)) ? -EFAULT : 0; | |
4760 | ||
1da177e4 LT |
4761 | return retval; |
4762 | ||
4763 | out_unlock: | |
5fe85be0 | 4764 | rcu_read_unlock(); |
1da177e4 LT |
4765 | return retval; |
4766 | } | |
4767 | ||
96f874e2 | 4768 | long sched_setaffinity(pid_t pid, const struct cpumask *in_mask) |
1da177e4 | 4769 | { |
5a16f3d3 | 4770 | cpumask_var_t cpus_allowed, new_mask; |
36c8b586 IM |
4771 | struct task_struct *p; |
4772 | int retval; | |
1da177e4 | 4773 | |
95402b38 | 4774 | get_online_cpus(); |
23f5d142 | 4775 | rcu_read_lock(); |
1da177e4 LT |
4776 | |
4777 | p = find_process_by_pid(pid); | |
4778 | if (!p) { | |
23f5d142 | 4779 | rcu_read_unlock(); |
95402b38 | 4780 | put_online_cpus(); |
1da177e4 LT |
4781 | return -ESRCH; |
4782 | } | |
4783 | ||
23f5d142 | 4784 | /* Prevent p going away */ |
1da177e4 | 4785 | get_task_struct(p); |
23f5d142 | 4786 | rcu_read_unlock(); |
1da177e4 | 4787 | |
5a16f3d3 RR |
4788 | if (!alloc_cpumask_var(&cpus_allowed, GFP_KERNEL)) { |
4789 | retval = -ENOMEM; | |
4790 | goto out_put_task; | |
4791 | } | |
4792 | if (!alloc_cpumask_var(&new_mask, GFP_KERNEL)) { | |
4793 | retval = -ENOMEM; | |
4794 | goto out_free_cpus_allowed; | |
4795 | } | |
1da177e4 | 4796 | retval = -EPERM; |
c69e8d9c | 4797 | if (!check_same_owner(p) && !capable(CAP_SYS_NICE)) |
1da177e4 LT |
4798 | goto out_unlock; |
4799 | ||
e7834f8f DQ |
4800 | retval = security_task_setscheduler(p, 0, NULL); |
4801 | if (retval) | |
4802 | goto out_unlock; | |
4803 | ||
5a16f3d3 RR |
4804 | cpuset_cpus_allowed(p, cpus_allowed); |
4805 | cpumask_and(new_mask, in_mask, cpus_allowed); | |
8707d8b8 | 4806 | again: |
5a16f3d3 | 4807 | retval = set_cpus_allowed_ptr(p, new_mask); |
1da177e4 | 4808 | |
8707d8b8 | 4809 | if (!retval) { |
5a16f3d3 RR |
4810 | cpuset_cpus_allowed(p, cpus_allowed); |
4811 | if (!cpumask_subset(new_mask, cpus_allowed)) { | |
8707d8b8 PM |
4812 | /* |
4813 | * We must have raced with a concurrent cpuset | |
4814 | * update. Just reset the cpus_allowed to the | |
4815 | * cpuset's cpus_allowed | |
4816 | */ | |
5a16f3d3 | 4817 | cpumask_copy(new_mask, cpus_allowed); |
8707d8b8 PM |
4818 | goto again; |
4819 | } | |
4820 | } | |
1da177e4 | 4821 | out_unlock: |
5a16f3d3 RR |
4822 | free_cpumask_var(new_mask); |
4823 | out_free_cpus_allowed: | |
4824 | free_cpumask_var(cpus_allowed); | |
4825 | out_put_task: | |
1da177e4 | 4826 | put_task_struct(p); |
95402b38 | 4827 | put_online_cpus(); |
1da177e4 LT |
4828 | return retval; |
4829 | } | |
4830 | ||
4831 | static int get_user_cpu_mask(unsigned long __user *user_mask_ptr, unsigned len, | |
96f874e2 | 4832 | struct cpumask *new_mask) |
1da177e4 | 4833 | { |
96f874e2 RR |
4834 | if (len < cpumask_size()) |
4835 | cpumask_clear(new_mask); | |
4836 | else if (len > cpumask_size()) | |
4837 | len = cpumask_size(); | |
4838 | ||
1da177e4 LT |
4839 | return copy_from_user(new_mask, user_mask_ptr, len) ? -EFAULT : 0; |
4840 | } | |
4841 | ||
4842 | /** | |
4843 | * sys_sched_setaffinity - set the cpu affinity of a process | |
4844 | * @pid: pid of the process | |
4845 | * @len: length in bytes of the bitmask pointed to by user_mask_ptr | |
4846 | * @user_mask_ptr: user-space pointer to the new cpu mask | |
4847 | */ | |
5add95d4 HC |
4848 | SYSCALL_DEFINE3(sched_setaffinity, pid_t, pid, unsigned int, len, |
4849 | unsigned long __user *, user_mask_ptr) | |
1da177e4 | 4850 | { |
5a16f3d3 | 4851 | cpumask_var_t new_mask; |
1da177e4 LT |
4852 | int retval; |
4853 | ||
5a16f3d3 RR |
4854 | if (!alloc_cpumask_var(&new_mask, GFP_KERNEL)) |
4855 | return -ENOMEM; | |
1da177e4 | 4856 | |
5a16f3d3 RR |
4857 | retval = get_user_cpu_mask(user_mask_ptr, len, new_mask); |
4858 | if (retval == 0) | |
4859 | retval = sched_setaffinity(pid, new_mask); | |
4860 | free_cpumask_var(new_mask); | |
4861 | return retval; | |
1da177e4 LT |
4862 | } |
4863 | ||
96f874e2 | 4864 | long sched_getaffinity(pid_t pid, struct cpumask *mask) |
1da177e4 | 4865 | { |
36c8b586 | 4866 | struct task_struct *p; |
31605683 TG |
4867 | unsigned long flags; |
4868 | struct rq *rq; | |
1da177e4 | 4869 | int retval; |
1da177e4 | 4870 | |
95402b38 | 4871 | get_online_cpus(); |
23f5d142 | 4872 | rcu_read_lock(); |
1da177e4 LT |
4873 | |
4874 | retval = -ESRCH; | |
4875 | p = find_process_by_pid(pid); | |
4876 | if (!p) | |
4877 | goto out_unlock; | |
4878 | ||
e7834f8f DQ |
4879 | retval = security_task_getscheduler(p); |
4880 | if (retval) | |
4881 | goto out_unlock; | |
4882 | ||
31605683 | 4883 | rq = task_rq_lock(p, &flags); |
96f874e2 | 4884 | cpumask_and(mask, &p->cpus_allowed, cpu_online_mask); |
31605683 | 4885 | task_rq_unlock(rq, &flags); |
1da177e4 LT |
4886 | |
4887 | out_unlock: | |
23f5d142 | 4888 | rcu_read_unlock(); |
95402b38 | 4889 | put_online_cpus(); |
1da177e4 | 4890 | |
9531b62f | 4891 | return retval; |
1da177e4 LT |
4892 | } |
4893 | ||
4894 | /** | |
4895 | * sys_sched_getaffinity - get the cpu affinity of a process | |
4896 | * @pid: pid of the process | |
4897 | * @len: length in bytes of the bitmask pointed to by user_mask_ptr | |
4898 | * @user_mask_ptr: user-space pointer to hold the current cpu mask | |
4899 | */ | |
5add95d4 HC |
4900 | SYSCALL_DEFINE3(sched_getaffinity, pid_t, pid, unsigned int, len, |
4901 | unsigned long __user *, user_mask_ptr) | |
1da177e4 LT |
4902 | { |
4903 | int ret; | |
f17c8607 | 4904 | cpumask_var_t mask; |
1da177e4 | 4905 | |
84fba5ec | 4906 | if ((len * BITS_PER_BYTE) < nr_cpu_ids) |
cd3d8031 KM |
4907 | return -EINVAL; |
4908 | if (len & (sizeof(unsigned long)-1)) | |
1da177e4 LT |
4909 | return -EINVAL; |
4910 | ||
f17c8607 RR |
4911 | if (!alloc_cpumask_var(&mask, GFP_KERNEL)) |
4912 | return -ENOMEM; | |
1da177e4 | 4913 | |
f17c8607 RR |
4914 | ret = sched_getaffinity(pid, mask); |
4915 | if (ret == 0) { | |
8bc037fb | 4916 | size_t retlen = min_t(size_t, len, cpumask_size()); |
cd3d8031 KM |
4917 | |
4918 | if (copy_to_user(user_mask_ptr, mask, retlen)) | |
f17c8607 RR |
4919 | ret = -EFAULT; |
4920 | else | |
cd3d8031 | 4921 | ret = retlen; |
f17c8607 RR |
4922 | } |
4923 | free_cpumask_var(mask); | |
1da177e4 | 4924 | |
f17c8607 | 4925 | return ret; |
1da177e4 LT |
4926 | } |
4927 | ||
4928 | /** | |
4929 | * sys_sched_yield - yield the current processor to other threads. | |
4930 | * | |
dd41f596 IM |
4931 | * This function yields the current CPU to other tasks. If there are no |
4932 | * other threads running on this CPU then this function will return. | |
1da177e4 | 4933 | */ |
5add95d4 | 4934 | SYSCALL_DEFINE0(sched_yield) |
1da177e4 | 4935 | { |
70b97a7f | 4936 | struct rq *rq = this_rq_lock(); |
1da177e4 | 4937 | |
2d72376b | 4938 | schedstat_inc(rq, yld_count); |
4530d7ab | 4939 | current->sched_class->yield_task(rq); |
1da177e4 LT |
4940 | |
4941 | /* | |
4942 | * Since we are going to call schedule() anyway, there's | |
4943 | * no need to preempt or enable interrupts: | |
4944 | */ | |
4945 | __release(rq->lock); | |
8a25d5de | 4946 | spin_release(&rq->lock.dep_map, 1, _THIS_IP_); |
9828ea9d | 4947 | do_raw_spin_unlock(&rq->lock); |
1da177e4 LT |
4948 | preempt_enable_no_resched(); |
4949 | ||
4950 | schedule(); | |
4951 | ||
4952 | return 0; | |
4953 | } | |
4954 | ||
d86ee480 PZ |
4955 | static inline int should_resched(void) |
4956 | { | |
4957 | return need_resched() && !(preempt_count() & PREEMPT_ACTIVE); | |
4958 | } | |
4959 | ||
e7b38404 | 4960 | static void __cond_resched(void) |
1da177e4 | 4961 | { |
e7aaaa69 FW |
4962 | add_preempt_count(PREEMPT_ACTIVE); |
4963 | schedule(); | |
4964 | sub_preempt_count(PREEMPT_ACTIVE); | |
1da177e4 LT |
4965 | } |
4966 | ||
02b67cc3 | 4967 | int __sched _cond_resched(void) |
1da177e4 | 4968 | { |
d86ee480 | 4969 | if (should_resched()) { |
1da177e4 LT |
4970 | __cond_resched(); |
4971 | return 1; | |
4972 | } | |
4973 | return 0; | |
4974 | } | |
02b67cc3 | 4975 | EXPORT_SYMBOL(_cond_resched); |
1da177e4 LT |
4976 | |
4977 | /* | |
613afbf8 | 4978 | * __cond_resched_lock() - if a reschedule is pending, drop the given lock, |
1da177e4 LT |
4979 | * call schedule, and on return reacquire the lock. |
4980 | * | |
41a2d6cf | 4981 | * This works OK both with and without CONFIG_PREEMPT. We do strange low-level |
1da177e4 LT |
4982 | * operations here to prevent schedule() from being called twice (once via |
4983 | * spin_unlock(), once by hand). | |
4984 | */ | |
613afbf8 | 4985 | int __cond_resched_lock(spinlock_t *lock) |
1da177e4 | 4986 | { |
d86ee480 | 4987 | int resched = should_resched(); |
6df3cecb JK |
4988 | int ret = 0; |
4989 | ||
f607c668 PZ |
4990 | lockdep_assert_held(lock); |
4991 | ||
95c354fe | 4992 | if (spin_needbreak(lock) || resched) { |
1da177e4 | 4993 | spin_unlock(lock); |
d86ee480 | 4994 | if (resched) |
95c354fe NP |
4995 | __cond_resched(); |
4996 | else | |
4997 | cpu_relax(); | |
6df3cecb | 4998 | ret = 1; |
1da177e4 | 4999 | spin_lock(lock); |
1da177e4 | 5000 | } |
6df3cecb | 5001 | return ret; |
1da177e4 | 5002 | } |
613afbf8 | 5003 | EXPORT_SYMBOL(__cond_resched_lock); |
1da177e4 | 5004 | |
613afbf8 | 5005 | int __sched __cond_resched_softirq(void) |
1da177e4 LT |
5006 | { |
5007 | BUG_ON(!in_softirq()); | |
5008 | ||
d86ee480 | 5009 | if (should_resched()) { |
98d82567 | 5010 | local_bh_enable(); |
1da177e4 LT |
5011 | __cond_resched(); |
5012 | local_bh_disable(); | |
5013 | return 1; | |
5014 | } | |
5015 | return 0; | |
5016 | } | |
613afbf8 | 5017 | EXPORT_SYMBOL(__cond_resched_softirq); |
1da177e4 | 5018 | |
1da177e4 LT |
5019 | /** |
5020 | * yield - yield the current processor to other threads. | |
5021 | * | |
72fd4a35 | 5022 | * This is a shortcut for kernel-space yielding - it marks the |
1da177e4 LT |
5023 | * thread runnable and calls sys_sched_yield(). |
5024 | */ | |
5025 | void __sched yield(void) | |
5026 | { | |
5027 | set_current_state(TASK_RUNNING); | |
5028 | sys_sched_yield(); | |
5029 | } | |
1da177e4 LT |
5030 | EXPORT_SYMBOL(yield); |
5031 | ||
5032 | /* | |
41a2d6cf | 5033 | * This task is about to go to sleep on IO. Increment rq->nr_iowait so |
1da177e4 | 5034 | * that process accounting knows that this is a task in IO wait state. |
1da177e4 LT |
5035 | */ |
5036 | void __sched io_schedule(void) | |
5037 | { | |
54d35f29 | 5038 | struct rq *rq = raw_rq(); |
1da177e4 | 5039 | |
0ff92245 | 5040 | delayacct_blkio_start(); |
1da177e4 | 5041 | atomic_inc(&rq->nr_iowait); |
8f0dfc34 | 5042 | current->in_iowait = 1; |
1da177e4 | 5043 | schedule(); |
8f0dfc34 | 5044 | current->in_iowait = 0; |
1da177e4 | 5045 | atomic_dec(&rq->nr_iowait); |
0ff92245 | 5046 | delayacct_blkio_end(); |
1da177e4 | 5047 | } |
1da177e4 LT |
5048 | EXPORT_SYMBOL(io_schedule); |
5049 | ||
5050 | long __sched io_schedule_timeout(long timeout) | |
5051 | { | |
54d35f29 | 5052 | struct rq *rq = raw_rq(); |
1da177e4 LT |
5053 | long ret; |
5054 | ||
0ff92245 | 5055 | delayacct_blkio_start(); |
1da177e4 | 5056 | atomic_inc(&rq->nr_iowait); |
8f0dfc34 | 5057 | current->in_iowait = 1; |
1da177e4 | 5058 | ret = schedule_timeout(timeout); |
8f0dfc34 | 5059 | current->in_iowait = 0; |
1da177e4 | 5060 | atomic_dec(&rq->nr_iowait); |
0ff92245 | 5061 | delayacct_blkio_end(); |
1da177e4 LT |
5062 | return ret; |
5063 | } | |
5064 | ||
5065 | /** | |
5066 | * sys_sched_get_priority_max - return maximum RT priority. | |
5067 | * @policy: scheduling class. | |
5068 | * | |
5069 | * this syscall returns the maximum rt_priority that can be used | |
5070 | * by a given scheduling class. | |
5071 | */ | |
5add95d4 | 5072 | SYSCALL_DEFINE1(sched_get_priority_max, int, policy) |
1da177e4 LT |
5073 | { |
5074 | int ret = -EINVAL; | |
5075 | ||
5076 | switch (policy) { | |
5077 | case SCHED_FIFO: | |
5078 | case SCHED_RR: | |
5079 | ret = MAX_USER_RT_PRIO-1; | |
5080 | break; | |
5081 | case SCHED_NORMAL: | |
b0a9499c | 5082 | case SCHED_BATCH: |
dd41f596 | 5083 | case SCHED_IDLE: |
1da177e4 LT |
5084 | ret = 0; |
5085 | break; | |
5086 | } | |
5087 | return ret; | |
5088 | } | |
5089 | ||
5090 | /** | |
5091 | * sys_sched_get_priority_min - return minimum RT priority. | |
5092 | * @policy: scheduling class. | |
5093 | * | |
5094 | * this syscall returns the minimum rt_priority that can be used | |
5095 | * by a given scheduling class. | |
5096 | */ | |
5add95d4 | 5097 | SYSCALL_DEFINE1(sched_get_priority_min, int, policy) |
1da177e4 LT |
5098 | { |
5099 | int ret = -EINVAL; | |
5100 | ||
5101 | switch (policy) { | |
5102 | case SCHED_FIFO: | |
5103 | case SCHED_RR: | |
5104 | ret = 1; | |
5105 | break; | |
5106 | case SCHED_NORMAL: | |
b0a9499c | 5107 | case SCHED_BATCH: |
dd41f596 | 5108 | case SCHED_IDLE: |
1da177e4 LT |
5109 | ret = 0; |
5110 | } | |
5111 | return ret; | |
5112 | } | |
5113 | ||
5114 | /** | |
5115 | * sys_sched_rr_get_interval - return the default timeslice of a process. | |
5116 | * @pid: pid of the process. | |
5117 | * @interval: userspace pointer to the timeslice value. | |
5118 | * | |
5119 | * this syscall writes the default timeslice value of a given process | |
5120 | * into the user-space timespec buffer. A value of '0' means infinity. | |
5121 | */ | |
17da2bd9 | 5122 | SYSCALL_DEFINE2(sched_rr_get_interval, pid_t, pid, |
754fe8d2 | 5123 | struct timespec __user *, interval) |
1da177e4 | 5124 | { |
36c8b586 | 5125 | struct task_struct *p; |
a4ec24b4 | 5126 | unsigned int time_slice; |
dba091b9 TG |
5127 | unsigned long flags; |
5128 | struct rq *rq; | |
3a5c359a | 5129 | int retval; |
1da177e4 | 5130 | struct timespec t; |
1da177e4 LT |
5131 | |
5132 | if (pid < 0) | |
3a5c359a | 5133 | return -EINVAL; |
1da177e4 LT |
5134 | |
5135 | retval = -ESRCH; | |
1a551ae7 | 5136 | rcu_read_lock(); |
1da177e4 LT |
5137 | p = find_process_by_pid(pid); |
5138 | if (!p) | |
5139 | goto out_unlock; | |
5140 | ||
5141 | retval = security_task_getscheduler(p); | |
5142 | if (retval) | |
5143 | goto out_unlock; | |
5144 | ||
dba091b9 TG |
5145 | rq = task_rq_lock(p, &flags); |
5146 | time_slice = p->sched_class->get_rr_interval(rq, p); | |
5147 | task_rq_unlock(rq, &flags); | |
a4ec24b4 | 5148 | |
1a551ae7 | 5149 | rcu_read_unlock(); |
a4ec24b4 | 5150 | jiffies_to_timespec(time_slice, &t); |
1da177e4 | 5151 | retval = copy_to_user(interval, &t, sizeof(t)) ? -EFAULT : 0; |
1da177e4 | 5152 | return retval; |
3a5c359a | 5153 | |
1da177e4 | 5154 | out_unlock: |
1a551ae7 | 5155 | rcu_read_unlock(); |
1da177e4 LT |
5156 | return retval; |
5157 | } | |
5158 | ||
7c731e0a | 5159 | static const char stat_nam[] = TASK_STATE_TO_CHAR_STR; |
36c8b586 | 5160 | |
82a1fcb9 | 5161 | void sched_show_task(struct task_struct *p) |
1da177e4 | 5162 | { |
1da177e4 | 5163 | unsigned long free = 0; |
36c8b586 | 5164 | unsigned state; |
1da177e4 | 5165 | |
1da177e4 | 5166 | state = p->state ? __ffs(p->state) + 1 : 0; |
3df0fc5b | 5167 | printk(KERN_INFO "%-13.13s %c", p->comm, |
2ed6e34f | 5168 | state < sizeof(stat_nam) - 1 ? stat_nam[state] : '?'); |
4bd77321 | 5169 | #if BITS_PER_LONG == 32 |
1da177e4 | 5170 | if (state == TASK_RUNNING) |
3df0fc5b | 5171 | printk(KERN_CONT " running "); |
1da177e4 | 5172 | else |
3df0fc5b | 5173 | printk(KERN_CONT " %08lx ", thread_saved_pc(p)); |
1da177e4 LT |
5174 | #else |
5175 | if (state == TASK_RUNNING) | |
3df0fc5b | 5176 | printk(KERN_CONT " running task "); |
1da177e4 | 5177 | else |
3df0fc5b | 5178 | printk(KERN_CONT " %016lx ", thread_saved_pc(p)); |
1da177e4 LT |
5179 | #endif |
5180 | #ifdef CONFIG_DEBUG_STACK_USAGE | |
7c9f8861 | 5181 | free = stack_not_used(p); |
1da177e4 | 5182 | #endif |
3df0fc5b | 5183 | printk(KERN_CONT "%5lu %5d %6d 0x%08lx\n", free, |
aa47b7e0 DR |
5184 | task_pid_nr(p), task_pid_nr(p->real_parent), |
5185 | (unsigned long)task_thread_info(p)->flags); | |
1da177e4 | 5186 | |
5fb5e6de | 5187 | show_stack(p, NULL); |
1da177e4 LT |
5188 | } |
5189 | ||
e59e2ae2 | 5190 | void show_state_filter(unsigned long state_filter) |
1da177e4 | 5191 | { |
36c8b586 | 5192 | struct task_struct *g, *p; |
1da177e4 | 5193 | |
4bd77321 | 5194 | #if BITS_PER_LONG == 32 |
3df0fc5b PZ |
5195 | printk(KERN_INFO |
5196 | " task PC stack pid father\n"); | |
1da177e4 | 5197 | #else |
3df0fc5b PZ |
5198 | printk(KERN_INFO |
5199 | " task PC stack pid father\n"); | |
1da177e4 LT |
5200 | #endif |
5201 | read_lock(&tasklist_lock); | |
5202 | do_each_thread(g, p) { | |
5203 | /* | |
5204 | * reset the NMI-timeout, listing all files on a slow | |
5205 | * console might take alot of time: | |
5206 | */ | |
5207 | touch_nmi_watchdog(); | |
39bc89fd | 5208 | if (!state_filter || (p->state & state_filter)) |
82a1fcb9 | 5209 | sched_show_task(p); |
1da177e4 LT |
5210 | } while_each_thread(g, p); |
5211 | ||
04c9167f JF |
5212 | touch_all_softlockup_watchdogs(); |
5213 | ||
dd41f596 IM |
5214 | #ifdef CONFIG_SCHED_DEBUG |
5215 | sysrq_sched_debug_show(); | |
5216 | #endif | |
1da177e4 | 5217 | read_unlock(&tasklist_lock); |
e59e2ae2 IM |
5218 | /* |
5219 | * Only show locks if all tasks are dumped: | |
5220 | */ | |
93335a21 | 5221 | if (!state_filter) |
e59e2ae2 | 5222 | debug_show_all_locks(); |
1da177e4 LT |
5223 | } |
5224 | ||
1df21055 IM |
5225 | void __cpuinit init_idle_bootup_task(struct task_struct *idle) |
5226 | { | |
dd41f596 | 5227 | idle->sched_class = &idle_sched_class; |
1df21055 IM |
5228 | } |
5229 | ||
f340c0d1 IM |
5230 | /** |
5231 | * init_idle - set up an idle thread for a given CPU | |
5232 | * @idle: task in question | |
5233 | * @cpu: cpu the idle task belongs to | |
5234 | * | |
5235 | * NOTE: this function does not set the idle thread's NEED_RESCHED | |
5236 | * flag, to make booting more robust. | |
5237 | */ | |
5c1e1767 | 5238 | void __cpuinit init_idle(struct task_struct *idle, int cpu) |
1da177e4 | 5239 | { |
70b97a7f | 5240 | struct rq *rq = cpu_rq(cpu); |
1da177e4 LT |
5241 | unsigned long flags; |
5242 | ||
05fa785c | 5243 | raw_spin_lock_irqsave(&rq->lock, flags); |
5cbd54ef | 5244 | |
dd41f596 | 5245 | __sched_fork(idle); |
06b83b5f | 5246 | idle->state = TASK_RUNNING; |
dd41f596 IM |
5247 | idle->se.exec_start = sched_clock(); |
5248 | ||
96f874e2 | 5249 | cpumask_copy(&idle->cpus_allowed, cpumask_of(cpu)); |
dd41f596 | 5250 | __set_task_cpu(idle, cpu); |
1da177e4 | 5251 | |
1da177e4 | 5252 | rq->curr = rq->idle = idle; |
4866cde0 NP |
5253 | #if defined(CONFIG_SMP) && defined(__ARCH_WANT_UNLOCKED_CTXSW) |
5254 | idle->oncpu = 1; | |
5255 | #endif | |
05fa785c | 5256 | raw_spin_unlock_irqrestore(&rq->lock, flags); |
1da177e4 LT |
5257 | |
5258 | /* Set the preempt count _outside_ the spinlocks! */ | |
8e3e076c LT |
5259 | #if defined(CONFIG_PREEMPT) |
5260 | task_thread_info(idle)->preempt_count = (idle->lock_depth >= 0); | |
5261 | #else | |
a1261f54 | 5262 | task_thread_info(idle)->preempt_count = 0; |
8e3e076c | 5263 | #endif |
dd41f596 IM |
5264 | /* |
5265 | * The idle tasks have their own, simple scheduling class: | |
5266 | */ | |
5267 | idle->sched_class = &idle_sched_class; | |
fb52607a | 5268 | ftrace_graph_init_task(idle); |
1da177e4 LT |
5269 | } |
5270 | ||
5271 | /* | |
5272 | * In a system that switches off the HZ timer nohz_cpu_mask | |
5273 | * indicates which cpus entered this state. This is used | |
5274 | * in the rcu update to wait only for active cpus. For system | |
5275 | * which do not switch off the HZ timer nohz_cpu_mask should | |
6a7b3dc3 | 5276 | * always be CPU_BITS_NONE. |
1da177e4 | 5277 | */ |
6a7b3dc3 | 5278 | cpumask_var_t nohz_cpu_mask; |
1da177e4 | 5279 | |
19978ca6 IM |
5280 | /* |
5281 | * Increase the granularity value when there are more CPUs, | |
5282 | * because with more CPUs the 'effective latency' as visible | |
5283 | * to users decreases. But the relationship is not linear, | |
5284 | * so pick a second-best guess by going with the log2 of the | |
5285 | * number of CPUs. | |
5286 | * | |
5287 | * This idea comes from the SD scheduler of Con Kolivas: | |
5288 | */ | |
acb4a848 | 5289 | static int get_update_sysctl_factor(void) |
19978ca6 | 5290 | { |
4ca3ef71 | 5291 | unsigned int cpus = min_t(int, num_online_cpus(), 8); |
1983a922 CE |
5292 | unsigned int factor; |
5293 | ||
5294 | switch (sysctl_sched_tunable_scaling) { | |
5295 | case SCHED_TUNABLESCALING_NONE: | |
5296 | factor = 1; | |
5297 | break; | |
5298 | case SCHED_TUNABLESCALING_LINEAR: | |
5299 | factor = cpus; | |
5300 | break; | |
5301 | case SCHED_TUNABLESCALING_LOG: | |
5302 | default: | |
5303 | factor = 1 + ilog2(cpus); | |
5304 | break; | |
5305 | } | |
19978ca6 | 5306 | |
acb4a848 CE |
5307 | return factor; |
5308 | } | |
19978ca6 | 5309 | |
acb4a848 CE |
5310 | static void update_sysctl(void) |
5311 | { | |
5312 | unsigned int factor = get_update_sysctl_factor(); | |
19978ca6 | 5313 | |
0bcdcf28 CE |
5314 | #define SET_SYSCTL(name) \ |
5315 | (sysctl_##name = (factor) * normalized_sysctl_##name) | |
5316 | SET_SYSCTL(sched_min_granularity); | |
5317 | SET_SYSCTL(sched_latency); | |
5318 | SET_SYSCTL(sched_wakeup_granularity); | |
5319 | SET_SYSCTL(sched_shares_ratelimit); | |
5320 | #undef SET_SYSCTL | |
5321 | } | |
55cd5340 | 5322 | |
0bcdcf28 CE |
5323 | static inline void sched_init_granularity(void) |
5324 | { | |
5325 | update_sysctl(); | |
19978ca6 IM |
5326 | } |
5327 | ||
1da177e4 LT |
5328 | #ifdef CONFIG_SMP |
5329 | /* | |
5330 | * This is how migration works: | |
5331 | * | |
70b97a7f | 5332 | * 1) we queue a struct migration_req structure in the source CPU's |
1da177e4 LT |
5333 | * runqueue and wake up that CPU's migration thread. |
5334 | * 2) we down() the locked semaphore => thread blocks. | |
5335 | * 3) migration thread wakes up (implicitly it forces the migrated | |
5336 | * thread off the CPU) | |
5337 | * 4) it gets the migration request and checks whether the migrated | |
5338 | * task is still in the wrong runqueue. | |
5339 | * 5) if it's in the wrong runqueue then the migration thread removes | |
5340 | * it and puts it into the right queue. | |
5341 | * 6) migration thread up()s the semaphore. | |
5342 | * 7) we wake up and the migration is done. | |
5343 | */ | |
5344 | ||
5345 | /* | |
5346 | * Change a given task's CPU affinity. Migrate the thread to a | |
5347 | * proper CPU and schedule it away if the CPU it's executing on | |
5348 | * is removed from the allowed bitmask. | |
5349 | * | |
5350 | * NOTE: the caller must have a valid reference to the task, the | |
41a2d6cf | 5351 | * task must not exit() & deallocate itself prematurely. The |
1da177e4 LT |
5352 | * call is not atomic; no spinlocks may be held. |
5353 | */ | |
96f874e2 | 5354 | int set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask) |
1da177e4 | 5355 | { |
70b97a7f | 5356 | struct migration_req req; |
1da177e4 | 5357 | unsigned long flags; |
70b97a7f | 5358 | struct rq *rq; |
48f24c4d | 5359 | int ret = 0; |
1da177e4 LT |
5360 | |
5361 | rq = task_rq_lock(p, &flags); | |
e2912009 | 5362 | |
6ad4c188 | 5363 | if (!cpumask_intersects(new_mask, cpu_active_mask)) { |
1da177e4 LT |
5364 | ret = -EINVAL; |
5365 | goto out; | |
5366 | } | |
5367 | ||
9985b0ba | 5368 | if (unlikely((p->flags & PF_THREAD_BOUND) && p != current && |
96f874e2 | 5369 | !cpumask_equal(&p->cpus_allowed, new_mask))) { |
9985b0ba DR |
5370 | ret = -EINVAL; |
5371 | goto out; | |
5372 | } | |
5373 | ||
73fe6aae | 5374 | if (p->sched_class->set_cpus_allowed) |
cd8ba7cd | 5375 | p->sched_class->set_cpus_allowed(p, new_mask); |
73fe6aae | 5376 | else { |
96f874e2 RR |
5377 | cpumask_copy(&p->cpus_allowed, new_mask); |
5378 | p->rt.nr_cpus_allowed = cpumask_weight(new_mask); | |
73fe6aae GH |
5379 | } |
5380 | ||
1da177e4 | 5381 | /* Can the task run on the task's current CPU? If so, we're done */ |
96f874e2 | 5382 | if (cpumask_test_cpu(task_cpu(p), new_mask)) |
1da177e4 LT |
5383 | goto out; |
5384 | ||
6ad4c188 | 5385 | if (migrate_task(p, cpumask_any_and(cpu_active_mask, new_mask), &req)) { |
1da177e4 | 5386 | /* Need help from migration thread: drop lock and wait. */ |
693525e3 PZ |
5387 | struct task_struct *mt = rq->migration_thread; |
5388 | ||
5389 | get_task_struct(mt); | |
1da177e4 | 5390 | task_rq_unlock(rq, &flags); |
47a70985 | 5391 | wake_up_process(mt); |
693525e3 | 5392 | put_task_struct(mt); |
1da177e4 LT |
5393 | wait_for_completion(&req.done); |
5394 | tlb_migrate_finish(p->mm); | |
5395 | return 0; | |
5396 | } | |
5397 | out: | |
5398 | task_rq_unlock(rq, &flags); | |
48f24c4d | 5399 | |
1da177e4 LT |
5400 | return ret; |
5401 | } | |
cd8ba7cd | 5402 | EXPORT_SYMBOL_GPL(set_cpus_allowed_ptr); |
1da177e4 LT |
5403 | |
5404 | /* | |
41a2d6cf | 5405 | * Move (not current) task off this cpu, onto dest cpu. We're doing |
1da177e4 LT |
5406 | * this because either it can't run here any more (set_cpus_allowed() |
5407 | * away from this CPU, or CPU going down), or because we're | |
5408 | * attempting to rebalance this task on exec (sched_exec). | |
5409 | * | |
5410 | * So we race with normal scheduler movements, but that's OK, as long | |
5411 | * as the task is no longer on this CPU. | |
efc30814 KK |
5412 | * |
5413 | * Returns non-zero if task was successfully migrated. | |
1da177e4 | 5414 | */ |
efc30814 | 5415 | static int __migrate_task(struct task_struct *p, int src_cpu, int dest_cpu) |
1da177e4 | 5416 | { |
70b97a7f | 5417 | struct rq *rq_dest, *rq_src; |
e2912009 | 5418 | int ret = 0; |
1da177e4 | 5419 | |
e761b772 | 5420 | if (unlikely(!cpu_active(dest_cpu))) |
efc30814 | 5421 | return ret; |
1da177e4 LT |
5422 | |
5423 | rq_src = cpu_rq(src_cpu); | |
5424 | rq_dest = cpu_rq(dest_cpu); | |
5425 | ||
5426 | double_rq_lock(rq_src, rq_dest); | |
5427 | /* Already moved. */ | |
5428 | if (task_cpu(p) != src_cpu) | |
b1e38734 | 5429 | goto done; |
1da177e4 | 5430 | /* Affinity changed (again). */ |
96f874e2 | 5431 | if (!cpumask_test_cpu(dest_cpu, &p->cpus_allowed)) |
b1e38734 | 5432 | goto fail; |
1da177e4 | 5433 | |
e2912009 PZ |
5434 | /* |
5435 | * If we're not on a rq, the next wake-up will ensure we're | |
5436 | * placed properly. | |
5437 | */ | |
5438 | if (p->se.on_rq) { | |
2e1cb74a | 5439 | deactivate_task(rq_src, p, 0); |
e2912009 | 5440 | set_task_cpu(p, dest_cpu); |
dd41f596 | 5441 | activate_task(rq_dest, p, 0); |
15afe09b | 5442 | check_preempt_curr(rq_dest, p, 0); |
1da177e4 | 5443 | } |
b1e38734 | 5444 | done: |
efc30814 | 5445 | ret = 1; |
b1e38734 | 5446 | fail: |
1da177e4 | 5447 | double_rq_unlock(rq_src, rq_dest); |
efc30814 | 5448 | return ret; |
1da177e4 LT |
5449 | } |
5450 | ||
03b042bf PM |
5451 | #define RCU_MIGRATION_IDLE 0 |
5452 | #define RCU_MIGRATION_NEED_QS 1 | |
5453 | #define RCU_MIGRATION_GOT_QS 2 | |
5454 | #define RCU_MIGRATION_MUST_SYNC 3 | |
5455 | ||
1da177e4 LT |
5456 | /* |
5457 | * migration_thread - this is a highprio system thread that performs | |
5458 | * thread migration by bumping thread off CPU then 'pushing' onto | |
5459 | * another runqueue. | |
5460 | */ | |
95cdf3b7 | 5461 | static int migration_thread(void *data) |
1da177e4 | 5462 | { |
03b042bf | 5463 | int badcpu; |
1da177e4 | 5464 | int cpu = (long)data; |
70b97a7f | 5465 | struct rq *rq; |
1da177e4 LT |
5466 | |
5467 | rq = cpu_rq(cpu); | |
5468 | BUG_ON(rq->migration_thread != current); | |
5469 | ||
5470 | set_current_state(TASK_INTERRUPTIBLE); | |
5471 | while (!kthread_should_stop()) { | |
70b97a7f | 5472 | struct migration_req *req; |
1da177e4 | 5473 | struct list_head *head; |
1da177e4 | 5474 | |
05fa785c | 5475 | raw_spin_lock_irq(&rq->lock); |
1da177e4 LT |
5476 | |
5477 | if (cpu_is_offline(cpu)) { | |
05fa785c | 5478 | raw_spin_unlock_irq(&rq->lock); |
371cbb38 | 5479 | break; |
1da177e4 LT |
5480 | } |
5481 | ||
5482 | if (rq->active_balance) { | |
5483 | active_load_balance(rq, cpu); | |
5484 | rq->active_balance = 0; | |
5485 | } | |
5486 | ||
5487 | head = &rq->migration_queue; | |
5488 | ||
5489 | if (list_empty(head)) { | |
05fa785c | 5490 | raw_spin_unlock_irq(&rq->lock); |
1da177e4 LT |
5491 | schedule(); |
5492 | set_current_state(TASK_INTERRUPTIBLE); | |
5493 | continue; | |
5494 | } | |
70b97a7f | 5495 | req = list_entry(head->next, struct migration_req, list); |
1da177e4 LT |
5496 | list_del_init(head->next); |
5497 | ||
03b042bf | 5498 | if (req->task != NULL) { |
05fa785c | 5499 | raw_spin_unlock(&rq->lock); |
03b042bf PM |
5500 | __migrate_task(req->task, cpu, req->dest_cpu); |
5501 | } else if (likely(cpu == (badcpu = smp_processor_id()))) { | |
5502 | req->dest_cpu = RCU_MIGRATION_GOT_QS; | |
05fa785c | 5503 | raw_spin_unlock(&rq->lock); |
03b042bf PM |
5504 | } else { |
5505 | req->dest_cpu = RCU_MIGRATION_MUST_SYNC; | |
05fa785c | 5506 | raw_spin_unlock(&rq->lock); |
03b042bf PM |
5507 | WARN_ONCE(1, "migration_thread() on CPU %d, expected %d\n", badcpu, cpu); |
5508 | } | |
674311d5 | 5509 | local_irq_enable(); |
1da177e4 LT |
5510 | |
5511 | complete(&req->done); | |
5512 | } | |
5513 | __set_current_state(TASK_RUNNING); | |
1da177e4 | 5514 | |
1da177e4 LT |
5515 | return 0; |
5516 | } | |
5517 | ||
5518 | #ifdef CONFIG_HOTPLUG_CPU | |
f7b4cddc ON |
5519 | |
5520 | static int __migrate_task_irq(struct task_struct *p, int src_cpu, int dest_cpu) | |
5521 | { | |
5522 | int ret; | |
5523 | ||
5524 | local_irq_disable(); | |
5525 | ret = __migrate_task(p, src_cpu, dest_cpu); | |
5526 | local_irq_enable(); | |
5527 | return ret; | |
5528 | } | |
5529 | ||
054b9108 | 5530 | /* |
3a4fa0a2 | 5531 | * Figure out where task on dead CPU should go, use force if necessary. |
054b9108 | 5532 | */ |
48f24c4d | 5533 | static void move_task_off_dead_cpu(int dead_cpu, struct task_struct *p) |
1da177e4 | 5534 | { |
70b97a7f | 5535 | int dest_cpu; |
e76bd8d9 RR |
5536 | |
5537 | again: | |
5da9a0fb | 5538 | dest_cpu = select_fallback_rq(dead_cpu, p); |
e76bd8d9 | 5539 | |
e76bd8d9 RR |
5540 | /* It can have affinity changed while we were choosing. */ |
5541 | if (unlikely(!__migrate_task_irq(p, dead_cpu, dest_cpu))) | |
5542 | goto again; | |
1da177e4 LT |
5543 | } |
5544 | ||
5545 | /* | |
5546 | * While a dead CPU has no uninterruptible tasks queued at this point, | |
5547 | * it might still have a nonzero ->nr_uninterruptible counter, because | |
5548 | * for performance reasons the counter is not stricly tracking tasks to | |
5549 | * their home CPUs. So we just add the counter to another CPU's counter, | |
5550 | * to keep the global sum constant after CPU-down: | |
5551 | */ | |
70b97a7f | 5552 | static void migrate_nr_uninterruptible(struct rq *rq_src) |
1da177e4 | 5553 | { |
6ad4c188 | 5554 | struct rq *rq_dest = cpu_rq(cpumask_any(cpu_active_mask)); |
1da177e4 LT |
5555 | unsigned long flags; |
5556 | ||
5557 | local_irq_save(flags); | |
5558 | double_rq_lock(rq_src, rq_dest); | |
5559 | rq_dest->nr_uninterruptible += rq_src->nr_uninterruptible; | |
5560 | rq_src->nr_uninterruptible = 0; | |
5561 | double_rq_unlock(rq_src, rq_dest); | |
5562 | local_irq_restore(flags); | |
5563 | } | |
5564 | ||
5565 | /* Run through task list and migrate tasks from the dead cpu. */ | |
5566 | static void migrate_live_tasks(int src_cpu) | |
5567 | { | |
48f24c4d | 5568 | struct task_struct *p, *t; |
1da177e4 | 5569 | |
f7b4cddc | 5570 | read_lock(&tasklist_lock); |
1da177e4 | 5571 | |
48f24c4d IM |
5572 | do_each_thread(t, p) { |
5573 | if (p == current) | |
1da177e4 LT |
5574 | continue; |
5575 | ||
48f24c4d IM |
5576 | if (task_cpu(p) == src_cpu) |
5577 | move_task_off_dead_cpu(src_cpu, p); | |
5578 | } while_each_thread(t, p); | |
1da177e4 | 5579 | |
f7b4cddc | 5580 | read_unlock(&tasklist_lock); |
1da177e4 LT |
5581 | } |
5582 | ||
dd41f596 IM |
5583 | /* |
5584 | * Schedules idle task to be the next runnable task on current CPU. | |
94bc9a7b DA |
5585 | * It does so by boosting its priority to highest possible. |
5586 | * Used by CPU offline code. | |
1da177e4 LT |
5587 | */ |
5588 | void sched_idle_next(void) | |
5589 | { | |
48f24c4d | 5590 | int this_cpu = smp_processor_id(); |
70b97a7f | 5591 | struct rq *rq = cpu_rq(this_cpu); |
1da177e4 LT |
5592 | struct task_struct *p = rq->idle; |
5593 | unsigned long flags; | |
5594 | ||
5595 | /* cpu has to be offline */ | |
48f24c4d | 5596 | BUG_ON(cpu_online(this_cpu)); |
1da177e4 | 5597 | |
48f24c4d IM |
5598 | /* |
5599 | * Strictly not necessary since rest of the CPUs are stopped by now | |
5600 | * and interrupts disabled on the current cpu. | |
1da177e4 | 5601 | */ |
05fa785c | 5602 | raw_spin_lock_irqsave(&rq->lock, flags); |
1da177e4 | 5603 | |
dd41f596 | 5604 | __setscheduler(rq, p, SCHED_FIFO, MAX_RT_PRIO-1); |
48f24c4d | 5605 | |
94bc9a7b DA |
5606 | update_rq_clock(rq); |
5607 | activate_task(rq, p, 0); | |
1da177e4 | 5608 | |
05fa785c | 5609 | raw_spin_unlock_irqrestore(&rq->lock, flags); |
1da177e4 LT |
5610 | } |
5611 | ||
48f24c4d IM |
5612 | /* |
5613 | * Ensures that the idle task is using init_mm right before its cpu goes | |
1da177e4 LT |
5614 | * offline. |
5615 | */ | |
5616 | void idle_task_exit(void) | |
5617 | { | |
5618 | struct mm_struct *mm = current->active_mm; | |
5619 | ||
5620 | BUG_ON(cpu_online(smp_processor_id())); | |
5621 | ||
5622 | if (mm != &init_mm) | |
5623 | switch_mm(mm, &init_mm, current); | |
5624 | mmdrop(mm); | |
5625 | } | |
5626 | ||
054b9108 | 5627 | /* called under rq->lock with disabled interrupts */ |
36c8b586 | 5628 | static void migrate_dead(unsigned int dead_cpu, struct task_struct *p) |
1da177e4 | 5629 | { |
70b97a7f | 5630 | struct rq *rq = cpu_rq(dead_cpu); |
1da177e4 LT |
5631 | |
5632 | /* Must be exiting, otherwise would be on tasklist. */ | |
270f722d | 5633 | BUG_ON(!p->exit_state); |
1da177e4 LT |
5634 | |
5635 | /* Cannot have done final schedule yet: would have vanished. */ | |
c394cc9f | 5636 | BUG_ON(p->state == TASK_DEAD); |
1da177e4 | 5637 | |
48f24c4d | 5638 | get_task_struct(p); |
1da177e4 LT |
5639 | |
5640 | /* | |
5641 | * Drop lock around migration; if someone else moves it, | |
41a2d6cf | 5642 | * that's OK. No task can be added to this CPU, so iteration is |
1da177e4 LT |
5643 | * fine. |
5644 | */ | |
05fa785c | 5645 | raw_spin_unlock_irq(&rq->lock); |
48f24c4d | 5646 | move_task_off_dead_cpu(dead_cpu, p); |
05fa785c | 5647 | raw_spin_lock_irq(&rq->lock); |
1da177e4 | 5648 | |
48f24c4d | 5649 | put_task_struct(p); |
1da177e4 LT |
5650 | } |
5651 | ||
5652 | /* release_task() removes task from tasklist, so we won't find dead tasks. */ | |
5653 | static void migrate_dead_tasks(unsigned int dead_cpu) | |
5654 | { | |
70b97a7f | 5655 | struct rq *rq = cpu_rq(dead_cpu); |
dd41f596 | 5656 | struct task_struct *next; |
48f24c4d | 5657 | |
dd41f596 IM |
5658 | for ( ; ; ) { |
5659 | if (!rq->nr_running) | |
5660 | break; | |
a8e504d2 | 5661 | update_rq_clock(rq); |
b67802ea | 5662 | next = pick_next_task(rq); |
dd41f596 IM |
5663 | if (!next) |
5664 | break; | |
79c53799 | 5665 | next->sched_class->put_prev_task(rq, next); |
dd41f596 | 5666 | migrate_dead(dead_cpu, next); |
e692ab53 | 5667 | |
1da177e4 LT |
5668 | } |
5669 | } | |
dce48a84 TG |
5670 | |
5671 | /* | |
5672 | * remove the tasks which were accounted by rq from calc_load_tasks. | |
5673 | */ | |
5674 | static void calc_global_load_remove(struct rq *rq) | |
5675 | { | |
5676 | atomic_long_sub(rq->calc_load_active, &calc_load_tasks); | |
a468d389 | 5677 | rq->calc_load_active = 0; |
dce48a84 | 5678 | } |
1da177e4 LT |
5679 | #endif /* CONFIG_HOTPLUG_CPU */ |
5680 | ||
e692ab53 NP |
5681 | #if defined(CONFIG_SCHED_DEBUG) && defined(CONFIG_SYSCTL) |
5682 | ||
5683 | static struct ctl_table sd_ctl_dir[] = { | |
e0361851 AD |
5684 | { |
5685 | .procname = "sched_domain", | |
c57baf1e | 5686 | .mode = 0555, |
e0361851 | 5687 | }, |
56992309 | 5688 | {} |
e692ab53 NP |
5689 | }; |
5690 | ||
5691 | static struct ctl_table sd_ctl_root[] = { | |
e0361851 AD |
5692 | { |
5693 | .procname = "kernel", | |
c57baf1e | 5694 | .mode = 0555, |
e0361851 AD |
5695 | .child = sd_ctl_dir, |
5696 | }, | |
56992309 | 5697 | {} |
e692ab53 NP |
5698 | }; |
5699 | ||
5700 | static struct ctl_table *sd_alloc_ctl_entry(int n) | |
5701 | { | |
5702 | struct ctl_table *entry = | |
5cf9f062 | 5703 | kcalloc(n, sizeof(struct ctl_table), GFP_KERNEL); |
e692ab53 | 5704 | |
e692ab53 NP |
5705 | return entry; |
5706 | } | |
5707 | ||
6382bc90 MM |
5708 | static void sd_free_ctl_entry(struct ctl_table **tablep) |
5709 | { | |
cd790076 | 5710 | struct ctl_table *entry; |
6382bc90 | 5711 | |
cd790076 MM |
5712 | /* |
5713 | * In the intermediate directories, both the child directory and | |
5714 | * procname are dynamically allocated and could fail but the mode | |
41a2d6cf | 5715 | * will always be set. In the lowest directory the names are |
cd790076 MM |
5716 | * static strings and all have proc handlers. |
5717 | */ | |
5718 | for (entry = *tablep; entry->mode; entry++) { | |
6382bc90 MM |
5719 | if (entry->child) |
5720 | sd_free_ctl_entry(&entry->child); | |
cd790076 MM |
5721 | if (entry->proc_handler == NULL) |
5722 | kfree(entry->procname); | |
5723 | } | |
6382bc90 MM |
5724 | |
5725 | kfree(*tablep); | |
5726 | *tablep = NULL; | |
5727 | } | |
5728 | ||
e692ab53 | 5729 | static void |
e0361851 | 5730 | set_table_entry(struct ctl_table *entry, |
e692ab53 NP |
5731 | const char *procname, void *data, int maxlen, |
5732 | mode_t mode, proc_handler *proc_handler) | |
5733 | { | |
e692ab53 NP |
5734 | entry->procname = procname; |
5735 | entry->data = data; | |
5736 | entry->maxlen = maxlen; | |
5737 | entry->mode = mode; | |
5738 | entry->proc_handler = proc_handler; | |
5739 | } | |
5740 | ||
5741 | static struct ctl_table * | |
5742 | sd_alloc_ctl_domain_table(struct sched_domain *sd) | |
5743 | { | |
a5d8c348 | 5744 | struct ctl_table *table = sd_alloc_ctl_entry(13); |
e692ab53 | 5745 | |
ad1cdc1d MM |
5746 | if (table == NULL) |
5747 | return NULL; | |
5748 | ||
e0361851 | 5749 | set_table_entry(&table[0], "min_interval", &sd->min_interval, |
e692ab53 | 5750 | sizeof(long), 0644, proc_doulongvec_minmax); |
e0361851 | 5751 | set_table_entry(&table[1], "max_interval", &sd->max_interval, |
e692ab53 | 5752 | sizeof(long), 0644, proc_doulongvec_minmax); |
e0361851 | 5753 | set_table_entry(&table[2], "busy_idx", &sd->busy_idx, |
e692ab53 | 5754 | sizeof(int), 0644, proc_dointvec_minmax); |
e0361851 | 5755 | set_table_entry(&table[3], "idle_idx", &sd->idle_idx, |
e692ab53 | 5756 | sizeof(int), 0644, proc_dointvec_minmax); |
e0361851 | 5757 | set_table_entry(&table[4], "newidle_idx", &sd->newidle_idx, |
e692ab53 | 5758 | sizeof(int), 0644, proc_dointvec_minmax); |
e0361851 | 5759 | set_table_entry(&table[5], "wake_idx", &sd->wake_idx, |
e692ab53 | 5760 | sizeof(int), 0644, proc_dointvec_minmax); |
e0361851 | 5761 | set_table_entry(&table[6], "forkexec_idx", &sd->forkexec_idx, |
e692ab53 | 5762 | sizeof(int), 0644, proc_dointvec_minmax); |
e0361851 | 5763 | set_table_entry(&table[7], "busy_factor", &sd->busy_factor, |
e692ab53 | 5764 | sizeof(int), 0644, proc_dointvec_minmax); |
e0361851 | 5765 | set_table_entry(&table[8], "imbalance_pct", &sd->imbalance_pct, |
e692ab53 | 5766 | sizeof(int), 0644, proc_dointvec_minmax); |
ace8b3d6 | 5767 | set_table_entry(&table[9], "cache_nice_tries", |
e692ab53 NP |
5768 | &sd->cache_nice_tries, |
5769 | sizeof(int), 0644, proc_dointvec_minmax); | |
ace8b3d6 | 5770 | set_table_entry(&table[10], "flags", &sd->flags, |
e692ab53 | 5771 | sizeof(int), 0644, proc_dointvec_minmax); |
a5d8c348 IM |
5772 | set_table_entry(&table[11], "name", sd->name, |
5773 | CORENAME_MAX_SIZE, 0444, proc_dostring); | |
5774 | /* &table[12] is terminator */ | |
e692ab53 NP |
5775 | |
5776 | return table; | |
5777 | } | |
5778 | ||
9a4e7159 | 5779 | static ctl_table *sd_alloc_ctl_cpu_table(int cpu) |
e692ab53 NP |
5780 | { |
5781 | struct ctl_table *entry, *table; | |
5782 | struct sched_domain *sd; | |
5783 | int domain_num = 0, i; | |
5784 | char buf[32]; | |
5785 | ||
5786 | for_each_domain(cpu, sd) | |
5787 | domain_num++; | |
5788 | entry = table = sd_alloc_ctl_entry(domain_num + 1); | |
ad1cdc1d MM |
5789 | if (table == NULL) |
5790 | return NULL; | |
e692ab53 NP |
5791 | |
5792 | i = 0; | |
5793 | for_each_domain(cpu, sd) { | |
5794 | snprintf(buf, 32, "domain%d", i); | |
e692ab53 | 5795 | entry->procname = kstrdup(buf, GFP_KERNEL); |
c57baf1e | 5796 | entry->mode = 0555; |
e692ab53 NP |
5797 | entry->child = sd_alloc_ctl_domain_table(sd); |
5798 | entry++; | |
5799 | i++; | |
5800 | } | |
5801 | return table; | |
5802 | } | |
5803 | ||
5804 | static struct ctl_table_header *sd_sysctl_header; | |
6382bc90 | 5805 | static void register_sched_domain_sysctl(void) |
e692ab53 | 5806 | { |
6ad4c188 | 5807 | int i, cpu_num = num_possible_cpus(); |
e692ab53 NP |
5808 | struct ctl_table *entry = sd_alloc_ctl_entry(cpu_num + 1); |
5809 | char buf[32]; | |
5810 | ||
7378547f MM |
5811 | WARN_ON(sd_ctl_dir[0].child); |
5812 | sd_ctl_dir[0].child = entry; | |
5813 | ||
ad1cdc1d MM |
5814 | if (entry == NULL) |
5815 | return; | |
5816 | ||
6ad4c188 | 5817 | for_each_possible_cpu(i) { |
e692ab53 | 5818 | snprintf(buf, 32, "cpu%d", i); |
e692ab53 | 5819 | entry->procname = kstrdup(buf, GFP_KERNEL); |
c57baf1e | 5820 | entry->mode = 0555; |
e692ab53 | 5821 | entry->child = sd_alloc_ctl_cpu_table(i); |
97b6ea7b | 5822 | entry++; |
e692ab53 | 5823 | } |
7378547f MM |
5824 | |
5825 | WARN_ON(sd_sysctl_header); | |
e692ab53 NP |
5826 | sd_sysctl_header = register_sysctl_table(sd_ctl_root); |
5827 | } | |
6382bc90 | 5828 | |
7378547f | 5829 | /* may be called multiple times per register */ |
6382bc90 MM |
5830 | static void unregister_sched_domain_sysctl(void) |
5831 | { | |
7378547f MM |
5832 | if (sd_sysctl_header) |
5833 | unregister_sysctl_table(sd_sysctl_header); | |
6382bc90 | 5834 | sd_sysctl_header = NULL; |
7378547f MM |
5835 | if (sd_ctl_dir[0].child) |
5836 | sd_free_ctl_entry(&sd_ctl_dir[0].child); | |
6382bc90 | 5837 | } |
e692ab53 | 5838 | #else |
6382bc90 MM |
5839 | static void register_sched_domain_sysctl(void) |
5840 | { | |
5841 | } | |
5842 | static void unregister_sched_domain_sysctl(void) | |
e692ab53 NP |
5843 | { |
5844 | } | |
5845 | #endif | |
5846 | ||
1f11eb6a GH |
5847 | static void set_rq_online(struct rq *rq) |
5848 | { | |
5849 | if (!rq->online) { | |
5850 | const struct sched_class *class; | |
5851 | ||
c6c4927b | 5852 | cpumask_set_cpu(rq->cpu, rq->rd->online); |
1f11eb6a GH |
5853 | rq->online = 1; |
5854 | ||
5855 | for_each_class(class) { | |
5856 | if (class->rq_online) | |
5857 | class->rq_online(rq); | |
5858 | } | |
5859 | } | |
5860 | } | |
5861 | ||
5862 | static void set_rq_offline(struct rq *rq) | |
5863 | { | |
5864 | if (rq->online) { | |
5865 | const struct sched_class *class; | |
5866 | ||
5867 | for_each_class(class) { | |
5868 | if (class->rq_offline) | |
5869 | class->rq_offline(rq); | |
5870 | } | |
5871 | ||
c6c4927b | 5872 | cpumask_clear_cpu(rq->cpu, rq->rd->online); |
1f11eb6a GH |
5873 | rq->online = 0; |
5874 | } | |
5875 | } | |
5876 | ||
1da177e4 LT |
5877 | /* |
5878 | * migration_call - callback that gets triggered when a CPU is added. | |
5879 | * Here we can start up the necessary migration thread for the new CPU. | |
5880 | */ | |
48f24c4d IM |
5881 | static int __cpuinit |
5882 | migration_call(struct notifier_block *nfb, unsigned long action, void *hcpu) | |
1da177e4 | 5883 | { |
1da177e4 | 5884 | struct task_struct *p; |
48f24c4d | 5885 | int cpu = (long)hcpu; |
1da177e4 | 5886 | unsigned long flags; |
70b97a7f | 5887 | struct rq *rq; |
1da177e4 LT |
5888 | |
5889 | switch (action) { | |
5be9361c | 5890 | |
1da177e4 | 5891 | case CPU_UP_PREPARE: |
8bb78442 | 5892 | case CPU_UP_PREPARE_FROZEN: |
dd41f596 | 5893 | p = kthread_create(migration_thread, hcpu, "migration/%d", cpu); |
1da177e4 LT |
5894 | if (IS_ERR(p)) |
5895 | return NOTIFY_BAD; | |
1da177e4 LT |
5896 | kthread_bind(p, cpu); |
5897 | /* Must be high prio: stop_machine expects to yield to it. */ | |
5898 | rq = task_rq_lock(p, &flags); | |
dd41f596 | 5899 | __setscheduler(rq, p, SCHED_FIFO, MAX_RT_PRIO-1); |
1da177e4 | 5900 | task_rq_unlock(rq, &flags); |
371cbb38 | 5901 | get_task_struct(p); |
1da177e4 | 5902 | cpu_rq(cpu)->migration_thread = p; |
a468d389 | 5903 | rq->calc_load_update = calc_load_update; |
1da177e4 | 5904 | break; |
48f24c4d | 5905 | |
1da177e4 | 5906 | case CPU_ONLINE: |
8bb78442 | 5907 | case CPU_ONLINE_FROZEN: |
3a4fa0a2 | 5908 | /* Strictly unnecessary, as first user will wake it. */ |
1da177e4 | 5909 | wake_up_process(cpu_rq(cpu)->migration_thread); |
1f94ef59 GH |
5910 | |
5911 | /* Update our root-domain */ | |
5912 | rq = cpu_rq(cpu); | |
05fa785c | 5913 | raw_spin_lock_irqsave(&rq->lock, flags); |
1f94ef59 | 5914 | if (rq->rd) { |
c6c4927b | 5915 | BUG_ON(!cpumask_test_cpu(cpu, rq->rd->span)); |
1f11eb6a GH |
5916 | |
5917 | set_rq_online(rq); | |
1f94ef59 | 5918 | } |
05fa785c | 5919 | raw_spin_unlock_irqrestore(&rq->lock, flags); |
1da177e4 | 5920 | break; |
48f24c4d | 5921 | |
1da177e4 LT |
5922 | #ifdef CONFIG_HOTPLUG_CPU |
5923 | case CPU_UP_CANCELED: | |
8bb78442 | 5924 | case CPU_UP_CANCELED_FROZEN: |
fc75cdfa HC |
5925 | if (!cpu_rq(cpu)->migration_thread) |
5926 | break; | |
41a2d6cf | 5927 | /* Unbind it from offline cpu so it can run. Fall thru. */ |
a4c4af7c | 5928 | kthread_bind(cpu_rq(cpu)->migration_thread, |
1e5ce4f4 | 5929 | cpumask_any(cpu_online_mask)); |
1da177e4 | 5930 | kthread_stop(cpu_rq(cpu)->migration_thread); |
371cbb38 | 5931 | put_task_struct(cpu_rq(cpu)->migration_thread); |
1da177e4 LT |
5932 | cpu_rq(cpu)->migration_thread = NULL; |
5933 | break; | |
48f24c4d | 5934 | |
1da177e4 | 5935 | case CPU_DEAD: |
8bb78442 | 5936 | case CPU_DEAD_FROZEN: |
470fd646 | 5937 | cpuset_lock(); /* around calls to cpuset_cpus_allowed_lock() */ |
1da177e4 LT |
5938 | migrate_live_tasks(cpu); |
5939 | rq = cpu_rq(cpu); | |
5940 | kthread_stop(rq->migration_thread); | |
371cbb38 | 5941 | put_task_struct(rq->migration_thread); |
1da177e4 LT |
5942 | rq->migration_thread = NULL; |
5943 | /* Idle task back to normal (off runqueue, low prio) */ | |
05fa785c | 5944 | raw_spin_lock_irq(&rq->lock); |
a8e504d2 | 5945 | update_rq_clock(rq); |
2e1cb74a | 5946 | deactivate_task(rq, rq->idle, 0); |
dd41f596 IM |
5947 | __setscheduler(rq, rq->idle, SCHED_NORMAL, 0); |
5948 | rq->idle->sched_class = &idle_sched_class; | |
1da177e4 | 5949 | migrate_dead_tasks(cpu); |
05fa785c | 5950 | raw_spin_unlock_irq(&rq->lock); |
470fd646 | 5951 | cpuset_unlock(); |
1da177e4 LT |
5952 | migrate_nr_uninterruptible(rq); |
5953 | BUG_ON(rq->nr_running != 0); | |
dce48a84 | 5954 | calc_global_load_remove(rq); |
41a2d6cf IM |
5955 | /* |
5956 | * No need to migrate the tasks: it was best-effort if | |
5957 | * they didn't take sched_hotcpu_mutex. Just wake up | |
5958 | * the requestors. | |
5959 | */ | |
05fa785c | 5960 | raw_spin_lock_irq(&rq->lock); |
1da177e4 | 5961 | while (!list_empty(&rq->migration_queue)) { |
70b97a7f IM |
5962 | struct migration_req *req; |
5963 | ||
1da177e4 | 5964 | req = list_entry(rq->migration_queue.next, |
70b97a7f | 5965 | struct migration_req, list); |
1da177e4 | 5966 | list_del_init(&req->list); |
05fa785c | 5967 | raw_spin_unlock_irq(&rq->lock); |
1da177e4 | 5968 | complete(&req->done); |
05fa785c | 5969 | raw_spin_lock_irq(&rq->lock); |
1da177e4 | 5970 | } |
05fa785c | 5971 | raw_spin_unlock_irq(&rq->lock); |
1da177e4 | 5972 | break; |
57d885fe | 5973 | |
08f503b0 GH |
5974 | case CPU_DYING: |
5975 | case CPU_DYING_FROZEN: | |
57d885fe GH |
5976 | /* Update our root-domain */ |
5977 | rq = cpu_rq(cpu); | |
05fa785c | 5978 | raw_spin_lock_irqsave(&rq->lock, flags); |
57d885fe | 5979 | if (rq->rd) { |
c6c4927b | 5980 | BUG_ON(!cpumask_test_cpu(cpu, rq->rd->span)); |
1f11eb6a | 5981 | set_rq_offline(rq); |
57d885fe | 5982 | } |
05fa785c | 5983 | raw_spin_unlock_irqrestore(&rq->lock, flags); |
57d885fe | 5984 | break; |
1da177e4 LT |
5985 | #endif |
5986 | } | |
5987 | return NOTIFY_OK; | |
5988 | } | |
5989 | ||
f38b0820 PM |
5990 | /* |
5991 | * Register at high priority so that task migration (migrate_all_tasks) | |
5992 | * happens before everything else. This has to be lower priority than | |
cdd6c482 | 5993 | * the notifier in the perf_event subsystem, though. |
1da177e4 | 5994 | */ |
26c2143b | 5995 | static struct notifier_block __cpuinitdata migration_notifier = { |
1da177e4 LT |
5996 | .notifier_call = migration_call, |
5997 | .priority = 10 | |
5998 | }; | |
5999 | ||
7babe8db | 6000 | static int __init migration_init(void) |
1da177e4 LT |
6001 | { |
6002 | void *cpu = (void *)(long)smp_processor_id(); | |
07dccf33 | 6003 | int err; |
48f24c4d IM |
6004 | |
6005 | /* Start one for the boot CPU: */ | |
07dccf33 AM |
6006 | err = migration_call(&migration_notifier, CPU_UP_PREPARE, cpu); |
6007 | BUG_ON(err == NOTIFY_BAD); | |
1da177e4 LT |
6008 | migration_call(&migration_notifier, CPU_ONLINE, cpu); |
6009 | register_cpu_notifier(&migration_notifier); | |
7babe8db | 6010 | |
a004cd42 | 6011 | return 0; |
1da177e4 | 6012 | } |
7babe8db | 6013 | early_initcall(migration_init); |
1da177e4 LT |
6014 | #endif |
6015 | ||
6016 | #ifdef CONFIG_SMP | |
476f3534 | 6017 | |
3e9830dc | 6018 | #ifdef CONFIG_SCHED_DEBUG |
4dcf6aff | 6019 | |
f6630114 MT |
6020 | static __read_mostly int sched_domain_debug_enabled; |
6021 | ||
6022 | static int __init sched_domain_debug_setup(char *str) | |
6023 | { | |
6024 | sched_domain_debug_enabled = 1; | |
6025 | ||
6026 | return 0; | |
6027 | } | |
6028 | early_param("sched_debug", sched_domain_debug_setup); | |
6029 | ||
7c16ec58 | 6030 | static int sched_domain_debug_one(struct sched_domain *sd, int cpu, int level, |
96f874e2 | 6031 | struct cpumask *groupmask) |
1da177e4 | 6032 | { |
4dcf6aff | 6033 | struct sched_group *group = sd->groups; |
434d53b0 | 6034 | char str[256]; |
1da177e4 | 6035 | |
968ea6d8 | 6036 | cpulist_scnprintf(str, sizeof(str), sched_domain_span(sd)); |
96f874e2 | 6037 | cpumask_clear(groupmask); |
4dcf6aff IM |
6038 | |
6039 | printk(KERN_DEBUG "%*s domain %d: ", level, "", level); | |
6040 | ||
6041 | if (!(sd->flags & SD_LOAD_BALANCE)) { | |
3df0fc5b | 6042 | printk("does not load-balance\n"); |
4dcf6aff | 6043 | if (sd->parent) |
3df0fc5b PZ |
6044 | printk(KERN_ERR "ERROR: !SD_LOAD_BALANCE domain" |
6045 | " has parent"); | |
4dcf6aff | 6046 | return -1; |
41c7ce9a NP |
6047 | } |
6048 | ||
3df0fc5b | 6049 | printk(KERN_CONT "span %s level %s\n", str, sd->name); |
4dcf6aff | 6050 | |
758b2cdc | 6051 | if (!cpumask_test_cpu(cpu, sched_domain_span(sd))) { |
3df0fc5b PZ |
6052 | printk(KERN_ERR "ERROR: domain->span does not contain " |
6053 | "CPU%d\n", cpu); | |
4dcf6aff | 6054 | } |
758b2cdc | 6055 | if (!cpumask_test_cpu(cpu, sched_group_cpus(group))) { |
3df0fc5b PZ |
6056 | printk(KERN_ERR "ERROR: domain->groups does not contain" |
6057 | " CPU%d\n", cpu); | |
4dcf6aff | 6058 | } |
1da177e4 | 6059 | |
4dcf6aff | 6060 | printk(KERN_DEBUG "%*s groups:", level + 1, ""); |
1da177e4 | 6061 | do { |
4dcf6aff | 6062 | if (!group) { |
3df0fc5b PZ |
6063 | printk("\n"); |
6064 | printk(KERN_ERR "ERROR: group is NULL\n"); | |
1da177e4 LT |
6065 | break; |
6066 | } | |
6067 | ||
18a3885f | 6068 | if (!group->cpu_power) { |
3df0fc5b PZ |
6069 | printk(KERN_CONT "\n"); |
6070 | printk(KERN_ERR "ERROR: domain->cpu_power not " | |
6071 | "set\n"); | |
4dcf6aff IM |
6072 | break; |
6073 | } | |
1da177e4 | 6074 | |
758b2cdc | 6075 | if (!cpumask_weight(sched_group_cpus(group))) { |
3df0fc5b PZ |
6076 | printk(KERN_CONT "\n"); |
6077 | printk(KERN_ERR "ERROR: empty group\n"); | |
4dcf6aff IM |
6078 | break; |
6079 | } | |
1da177e4 | 6080 | |
758b2cdc | 6081 | if (cpumask_intersects(groupmask, sched_group_cpus(group))) { |
3df0fc5b PZ |
6082 | printk(KERN_CONT "\n"); |
6083 | printk(KERN_ERR "ERROR: repeated CPUs\n"); | |
4dcf6aff IM |
6084 | break; |
6085 | } | |
1da177e4 | 6086 | |
758b2cdc | 6087 | cpumask_or(groupmask, groupmask, sched_group_cpus(group)); |
1da177e4 | 6088 | |
968ea6d8 | 6089 | cpulist_scnprintf(str, sizeof(str), sched_group_cpus(group)); |
381512cf | 6090 | |
3df0fc5b | 6091 | printk(KERN_CONT " %s", str); |
18a3885f | 6092 | if (group->cpu_power != SCHED_LOAD_SCALE) { |
3df0fc5b PZ |
6093 | printk(KERN_CONT " (cpu_power = %d)", |
6094 | group->cpu_power); | |
381512cf | 6095 | } |
1da177e4 | 6096 | |
4dcf6aff IM |
6097 | group = group->next; |
6098 | } while (group != sd->groups); | |
3df0fc5b | 6099 | printk(KERN_CONT "\n"); |
1da177e4 | 6100 | |
758b2cdc | 6101 | if (!cpumask_equal(sched_domain_span(sd), groupmask)) |
3df0fc5b | 6102 | printk(KERN_ERR "ERROR: groups don't span domain->span\n"); |
1da177e4 | 6103 | |
758b2cdc RR |
6104 | if (sd->parent && |
6105 | !cpumask_subset(groupmask, sched_domain_span(sd->parent))) | |
3df0fc5b PZ |
6106 | printk(KERN_ERR "ERROR: parent span is not a superset " |
6107 | "of domain->span\n"); | |
4dcf6aff IM |
6108 | return 0; |
6109 | } | |
1da177e4 | 6110 | |
4dcf6aff IM |
6111 | static void sched_domain_debug(struct sched_domain *sd, int cpu) |
6112 | { | |
d5dd3db1 | 6113 | cpumask_var_t groupmask; |
4dcf6aff | 6114 | int level = 0; |
1da177e4 | 6115 | |
f6630114 MT |
6116 | if (!sched_domain_debug_enabled) |
6117 | return; | |
6118 | ||
4dcf6aff IM |
6119 | if (!sd) { |
6120 | printk(KERN_DEBUG "CPU%d attaching NULL sched-domain.\n", cpu); | |
6121 | return; | |
6122 | } | |
1da177e4 | 6123 | |
4dcf6aff IM |
6124 | printk(KERN_DEBUG "CPU%d attaching sched-domain:\n", cpu); |
6125 | ||
d5dd3db1 | 6126 | if (!alloc_cpumask_var(&groupmask, GFP_KERNEL)) { |
7c16ec58 MT |
6127 | printk(KERN_DEBUG "Cannot load-balance (out of memory)\n"); |
6128 | return; | |
6129 | } | |
6130 | ||
4dcf6aff | 6131 | for (;;) { |
7c16ec58 | 6132 | if (sched_domain_debug_one(sd, cpu, level, groupmask)) |
4dcf6aff | 6133 | break; |
1da177e4 LT |
6134 | level++; |
6135 | sd = sd->parent; | |
33859f7f | 6136 | if (!sd) |
4dcf6aff IM |
6137 | break; |
6138 | } | |
d5dd3db1 | 6139 | free_cpumask_var(groupmask); |
1da177e4 | 6140 | } |
6d6bc0ad | 6141 | #else /* !CONFIG_SCHED_DEBUG */ |
48f24c4d | 6142 | # define sched_domain_debug(sd, cpu) do { } while (0) |
6d6bc0ad | 6143 | #endif /* CONFIG_SCHED_DEBUG */ |
1da177e4 | 6144 | |
1a20ff27 | 6145 | static int sd_degenerate(struct sched_domain *sd) |
245af2c7 | 6146 | { |
758b2cdc | 6147 | if (cpumask_weight(sched_domain_span(sd)) == 1) |
245af2c7 SS |
6148 | return 1; |
6149 | ||
6150 | /* Following flags need at least 2 groups */ | |
6151 | if (sd->flags & (SD_LOAD_BALANCE | | |
6152 | SD_BALANCE_NEWIDLE | | |
6153 | SD_BALANCE_FORK | | |
89c4710e SS |
6154 | SD_BALANCE_EXEC | |
6155 | SD_SHARE_CPUPOWER | | |
6156 | SD_SHARE_PKG_RESOURCES)) { | |
245af2c7 SS |
6157 | if (sd->groups != sd->groups->next) |
6158 | return 0; | |
6159 | } | |
6160 | ||
6161 | /* Following flags don't use groups */ | |
c88d5910 | 6162 | if (sd->flags & (SD_WAKE_AFFINE)) |
245af2c7 SS |
6163 | return 0; |
6164 | ||
6165 | return 1; | |
6166 | } | |
6167 | ||
48f24c4d IM |
6168 | static int |
6169 | sd_parent_degenerate(struct sched_domain *sd, struct sched_domain *parent) | |
245af2c7 SS |
6170 | { |
6171 | unsigned long cflags = sd->flags, pflags = parent->flags; | |
6172 | ||
6173 | if (sd_degenerate(parent)) | |
6174 | return 1; | |
6175 | ||
758b2cdc | 6176 | if (!cpumask_equal(sched_domain_span(sd), sched_domain_span(parent))) |
245af2c7 SS |
6177 | return 0; |
6178 | ||
245af2c7 SS |
6179 | /* Flags needing groups don't count if only 1 group in parent */ |
6180 | if (parent->groups == parent->groups->next) { | |
6181 | pflags &= ~(SD_LOAD_BALANCE | | |
6182 | SD_BALANCE_NEWIDLE | | |
6183 | SD_BALANCE_FORK | | |
89c4710e SS |
6184 | SD_BALANCE_EXEC | |
6185 | SD_SHARE_CPUPOWER | | |
6186 | SD_SHARE_PKG_RESOURCES); | |
5436499e KC |
6187 | if (nr_node_ids == 1) |
6188 | pflags &= ~SD_SERIALIZE; | |
245af2c7 SS |
6189 | } |
6190 | if (~cflags & pflags) | |
6191 | return 0; | |
6192 | ||
6193 | return 1; | |
6194 | } | |
6195 | ||
c6c4927b RR |
6196 | static void free_rootdomain(struct root_domain *rd) |
6197 | { | |
047106ad PZ |
6198 | synchronize_sched(); |
6199 | ||
68e74568 RR |
6200 | cpupri_cleanup(&rd->cpupri); |
6201 | ||
c6c4927b RR |
6202 | free_cpumask_var(rd->rto_mask); |
6203 | free_cpumask_var(rd->online); | |
6204 | free_cpumask_var(rd->span); | |
6205 | kfree(rd); | |
6206 | } | |
6207 | ||
57d885fe GH |
6208 | static void rq_attach_root(struct rq *rq, struct root_domain *rd) |
6209 | { | |
a0490fa3 | 6210 | struct root_domain *old_rd = NULL; |
57d885fe | 6211 | unsigned long flags; |
57d885fe | 6212 | |
05fa785c | 6213 | raw_spin_lock_irqsave(&rq->lock, flags); |
57d885fe GH |
6214 | |
6215 | if (rq->rd) { | |
a0490fa3 | 6216 | old_rd = rq->rd; |
57d885fe | 6217 | |
c6c4927b | 6218 | if (cpumask_test_cpu(rq->cpu, old_rd->online)) |
1f11eb6a | 6219 | set_rq_offline(rq); |
57d885fe | 6220 | |
c6c4927b | 6221 | cpumask_clear_cpu(rq->cpu, old_rd->span); |
dc938520 | 6222 | |
a0490fa3 IM |
6223 | /* |
6224 | * If we dont want to free the old_rt yet then | |
6225 | * set old_rd to NULL to skip the freeing later | |
6226 | * in this function: | |
6227 | */ | |
6228 | if (!atomic_dec_and_test(&old_rd->refcount)) | |
6229 | old_rd = NULL; | |
57d885fe GH |
6230 | } |
6231 | ||
6232 | atomic_inc(&rd->refcount); | |
6233 | rq->rd = rd; | |
6234 | ||
c6c4927b | 6235 | cpumask_set_cpu(rq->cpu, rd->span); |
00aec93d | 6236 | if (cpumask_test_cpu(rq->cpu, cpu_active_mask)) |
1f11eb6a | 6237 | set_rq_online(rq); |
57d885fe | 6238 | |
05fa785c | 6239 | raw_spin_unlock_irqrestore(&rq->lock, flags); |
a0490fa3 IM |
6240 | |
6241 | if (old_rd) | |
6242 | free_rootdomain(old_rd); | |
57d885fe GH |
6243 | } |
6244 | ||
fd5e1b5d | 6245 | static int init_rootdomain(struct root_domain *rd, bool bootmem) |
57d885fe | 6246 | { |
36b7b6d4 PE |
6247 | gfp_t gfp = GFP_KERNEL; |
6248 | ||
57d885fe GH |
6249 | memset(rd, 0, sizeof(*rd)); |
6250 | ||
36b7b6d4 PE |
6251 | if (bootmem) |
6252 | gfp = GFP_NOWAIT; | |
c6c4927b | 6253 | |
36b7b6d4 | 6254 | if (!alloc_cpumask_var(&rd->span, gfp)) |
0c910d28 | 6255 | goto out; |
36b7b6d4 | 6256 | if (!alloc_cpumask_var(&rd->online, gfp)) |
c6c4927b | 6257 | goto free_span; |
36b7b6d4 | 6258 | if (!alloc_cpumask_var(&rd->rto_mask, gfp)) |
c6c4927b | 6259 | goto free_online; |
6e0534f2 | 6260 | |
0fb53029 | 6261 | if (cpupri_init(&rd->cpupri, bootmem) != 0) |
68e74568 | 6262 | goto free_rto_mask; |
c6c4927b | 6263 | return 0; |
6e0534f2 | 6264 | |
68e74568 RR |
6265 | free_rto_mask: |
6266 | free_cpumask_var(rd->rto_mask); | |
c6c4927b RR |
6267 | free_online: |
6268 | free_cpumask_var(rd->online); | |
6269 | free_span: | |
6270 | free_cpumask_var(rd->span); | |
0c910d28 | 6271 | out: |
c6c4927b | 6272 | return -ENOMEM; |
57d885fe GH |
6273 | } |
6274 | ||
6275 | static void init_defrootdomain(void) | |
6276 | { | |
c6c4927b RR |
6277 | init_rootdomain(&def_root_domain, true); |
6278 | ||
57d885fe GH |
6279 | atomic_set(&def_root_domain.refcount, 1); |
6280 | } | |
6281 | ||
dc938520 | 6282 | static struct root_domain *alloc_rootdomain(void) |
57d885fe GH |
6283 | { |
6284 | struct root_domain *rd; | |
6285 | ||
6286 | rd = kmalloc(sizeof(*rd), GFP_KERNEL); | |
6287 | if (!rd) | |
6288 | return NULL; | |
6289 | ||
c6c4927b RR |
6290 | if (init_rootdomain(rd, false) != 0) { |
6291 | kfree(rd); | |
6292 | return NULL; | |
6293 | } | |
57d885fe GH |
6294 | |
6295 | return rd; | |
6296 | } | |
6297 | ||
1da177e4 | 6298 | /* |
0eab9146 | 6299 | * Attach the domain 'sd' to 'cpu' as its base domain. Callers must |
1da177e4 LT |
6300 | * hold the hotplug lock. |
6301 | */ | |
0eab9146 IM |
6302 | static void |
6303 | cpu_attach_domain(struct sched_domain *sd, struct root_domain *rd, int cpu) | |
1da177e4 | 6304 | { |
70b97a7f | 6305 | struct rq *rq = cpu_rq(cpu); |
245af2c7 SS |
6306 | struct sched_domain *tmp; |
6307 | ||
6308 | /* Remove the sched domains which do not contribute to scheduling. */ | |
f29c9b1c | 6309 | for (tmp = sd; tmp; ) { |
245af2c7 SS |
6310 | struct sched_domain *parent = tmp->parent; |
6311 | if (!parent) | |
6312 | break; | |
f29c9b1c | 6313 | |
1a848870 | 6314 | if (sd_parent_degenerate(tmp, parent)) { |
245af2c7 | 6315 | tmp->parent = parent->parent; |
1a848870 SS |
6316 | if (parent->parent) |
6317 | parent->parent->child = tmp; | |
f29c9b1c LZ |
6318 | } else |
6319 | tmp = tmp->parent; | |
245af2c7 SS |
6320 | } |
6321 | ||
1a848870 | 6322 | if (sd && sd_degenerate(sd)) { |
245af2c7 | 6323 | sd = sd->parent; |
1a848870 SS |
6324 | if (sd) |
6325 | sd->child = NULL; | |
6326 | } | |
1da177e4 LT |
6327 | |
6328 | sched_domain_debug(sd, cpu); | |
6329 | ||
57d885fe | 6330 | rq_attach_root(rq, rd); |
674311d5 | 6331 | rcu_assign_pointer(rq->sd, sd); |
1da177e4 LT |
6332 | } |
6333 | ||
6334 | /* cpus with isolated domains */ | |
dcc30a35 | 6335 | static cpumask_var_t cpu_isolated_map; |
1da177e4 LT |
6336 | |
6337 | /* Setup the mask of cpus configured for isolated domains */ | |
6338 | static int __init isolated_cpu_setup(char *str) | |
6339 | { | |
bdddd296 | 6340 | alloc_bootmem_cpumask_var(&cpu_isolated_map); |
968ea6d8 | 6341 | cpulist_parse(str, cpu_isolated_map); |
1da177e4 LT |
6342 | return 1; |
6343 | } | |
6344 | ||
8927f494 | 6345 | __setup("isolcpus=", isolated_cpu_setup); |
1da177e4 LT |
6346 | |
6347 | /* | |
6711cab4 SS |
6348 | * init_sched_build_groups takes the cpumask we wish to span, and a pointer |
6349 | * to a function which identifies what group(along with sched group) a CPU | |
96f874e2 RR |
6350 | * belongs to. The return value of group_fn must be a >= 0 and < nr_cpu_ids |
6351 | * (due to the fact that we keep track of groups covered with a struct cpumask). | |
1da177e4 LT |
6352 | * |
6353 | * init_sched_build_groups will build a circular linked list of the groups | |
6354 | * covered by the given span, and will set each group's ->cpumask correctly, | |
6355 | * and ->cpu_power to 0. | |
6356 | */ | |
a616058b | 6357 | static void |
96f874e2 RR |
6358 | init_sched_build_groups(const struct cpumask *span, |
6359 | const struct cpumask *cpu_map, | |
6360 | int (*group_fn)(int cpu, const struct cpumask *cpu_map, | |
7c16ec58 | 6361 | struct sched_group **sg, |
96f874e2 RR |
6362 | struct cpumask *tmpmask), |
6363 | struct cpumask *covered, struct cpumask *tmpmask) | |
1da177e4 LT |
6364 | { |
6365 | struct sched_group *first = NULL, *last = NULL; | |
1da177e4 LT |
6366 | int i; |
6367 | ||
96f874e2 | 6368 | cpumask_clear(covered); |
7c16ec58 | 6369 | |
abcd083a | 6370 | for_each_cpu(i, span) { |
6711cab4 | 6371 | struct sched_group *sg; |
7c16ec58 | 6372 | int group = group_fn(i, cpu_map, &sg, tmpmask); |
1da177e4 LT |
6373 | int j; |
6374 | ||
758b2cdc | 6375 | if (cpumask_test_cpu(i, covered)) |
1da177e4 LT |
6376 | continue; |
6377 | ||
758b2cdc | 6378 | cpumask_clear(sched_group_cpus(sg)); |
18a3885f | 6379 | sg->cpu_power = 0; |
1da177e4 | 6380 | |
abcd083a | 6381 | for_each_cpu(j, span) { |
7c16ec58 | 6382 | if (group_fn(j, cpu_map, NULL, tmpmask) != group) |
1da177e4 LT |
6383 | continue; |
6384 | ||
96f874e2 | 6385 | cpumask_set_cpu(j, covered); |
758b2cdc | 6386 | cpumask_set_cpu(j, sched_group_cpus(sg)); |
1da177e4 LT |
6387 | } |
6388 | if (!first) | |
6389 | first = sg; | |
6390 | if (last) | |
6391 | last->next = sg; | |
6392 | last = sg; | |
6393 | } | |
6394 | last->next = first; | |
6395 | } | |
6396 | ||
9c1cfda2 | 6397 | #define SD_NODES_PER_DOMAIN 16 |
1da177e4 | 6398 | |
9c1cfda2 | 6399 | #ifdef CONFIG_NUMA |
198e2f18 | 6400 | |
9c1cfda2 JH |
6401 | /** |
6402 | * find_next_best_node - find the next node to include in a sched_domain | |
6403 | * @node: node whose sched_domain we're building | |
6404 | * @used_nodes: nodes already in the sched_domain | |
6405 | * | |
41a2d6cf | 6406 | * Find the next node to include in a given scheduling domain. Simply |
9c1cfda2 JH |
6407 | * finds the closest node not already in the @used_nodes map. |
6408 | * | |
6409 | * Should use nodemask_t. | |
6410 | */ | |
c5f59f08 | 6411 | static int find_next_best_node(int node, nodemask_t *used_nodes) |
9c1cfda2 JH |
6412 | { |
6413 | int i, n, val, min_val, best_node = 0; | |
6414 | ||
6415 | min_val = INT_MAX; | |
6416 | ||
076ac2af | 6417 | for (i = 0; i < nr_node_ids; i++) { |
9c1cfda2 | 6418 | /* Start at @node */ |
076ac2af | 6419 | n = (node + i) % nr_node_ids; |
9c1cfda2 JH |
6420 | |
6421 | if (!nr_cpus_node(n)) | |
6422 | continue; | |
6423 | ||
6424 | /* Skip already used nodes */ | |
c5f59f08 | 6425 | if (node_isset(n, *used_nodes)) |
9c1cfda2 JH |
6426 | continue; |
6427 | ||
6428 | /* Simple min distance search */ | |
6429 | val = node_distance(node, n); | |
6430 | ||
6431 | if (val < min_val) { | |
6432 | min_val = val; | |
6433 | best_node = n; | |
6434 | } | |
6435 | } | |
6436 | ||
c5f59f08 | 6437 | node_set(best_node, *used_nodes); |
9c1cfda2 JH |
6438 | return best_node; |
6439 | } | |
6440 | ||
6441 | /** | |
6442 | * sched_domain_node_span - get a cpumask for a node's sched_domain | |
6443 | * @node: node whose cpumask we're constructing | |
73486722 | 6444 | * @span: resulting cpumask |
9c1cfda2 | 6445 | * |
41a2d6cf | 6446 | * Given a node, construct a good cpumask for its sched_domain to span. It |
9c1cfda2 JH |
6447 | * should be one that prevents unnecessary balancing, but also spreads tasks |
6448 | * out optimally. | |
6449 | */ | |
96f874e2 | 6450 | static void sched_domain_node_span(int node, struct cpumask *span) |
9c1cfda2 | 6451 | { |
c5f59f08 | 6452 | nodemask_t used_nodes; |
48f24c4d | 6453 | int i; |
9c1cfda2 | 6454 | |
6ca09dfc | 6455 | cpumask_clear(span); |
c5f59f08 | 6456 | nodes_clear(used_nodes); |
9c1cfda2 | 6457 | |
6ca09dfc | 6458 | cpumask_or(span, span, cpumask_of_node(node)); |
c5f59f08 | 6459 | node_set(node, used_nodes); |
9c1cfda2 JH |
6460 | |
6461 | for (i = 1; i < SD_NODES_PER_DOMAIN; i++) { | |
c5f59f08 | 6462 | int next_node = find_next_best_node(node, &used_nodes); |
48f24c4d | 6463 | |
6ca09dfc | 6464 | cpumask_or(span, span, cpumask_of_node(next_node)); |
9c1cfda2 | 6465 | } |
9c1cfda2 | 6466 | } |
6d6bc0ad | 6467 | #endif /* CONFIG_NUMA */ |
9c1cfda2 | 6468 | |
5c45bf27 | 6469 | int sched_smt_power_savings = 0, sched_mc_power_savings = 0; |
48f24c4d | 6470 | |
6c99e9ad RR |
6471 | /* |
6472 | * The cpus mask in sched_group and sched_domain hangs off the end. | |
4200efd9 IM |
6473 | * |
6474 | * ( See the the comments in include/linux/sched.h:struct sched_group | |
6475 | * and struct sched_domain. ) | |
6c99e9ad RR |
6476 | */ |
6477 | struct static_sched_group { | |
6478 | struct sched_group sg; | |
6479 | DECLARE_BITMAP(cpus, CONFIG_NR_CPUS); | |
6480 | }; | |
6481 | ||
6482 | struct static_sched_domain { | |
6483 | struct sched_domain sd; | |
6484 | DECLARE_BITMAP(span, CONFIG_NR_CPUS); | |
6485 | }; | |
6486 | ||
49a02c51 AH |
6487 | struct s_data { |
6488 | #ifdef CONFIG_NUMA | |
6489 | int sd_allnodes; | |
6490 | cpumask_var_t domainspan; | |
6491 | cpumask_var_t covered; | |
6492 | cpumask_var_t notcovered; | |
6493 | #endif | |
6494 | cpumask_var_t nodemask; | |
6495 | cpumask_var_t this_sibling_map; | |
6496 | cpumask_var_t this_core_map; | |
6497 | cpumask_var_t send_covered; | |
6498 | cpumask_var_t tmpmask; | |
6499 | struct sched_group **sched_group_nodes; | |
6500 | struct root_domain *rd; | |
6501 | }; | |
6502 | ||
2109b99e AH |
6503 | enum s_alloc { |
6504 | sa_sched_groups = 0, | |
6505 | sa_rootdomain, | |
6506 | sa_tmpmask, | |
6507 | sa_send_covered, | |
6508 | sa_this_core_map, | |
6509 | sa_this_sibling_map, | |
6510 | sa_nodemask, | |
6511 | sa_sched_group_nodes, | |
6512 | #ifdef CONFIG_NUMA | |
6513 | sa_notcovered, | |
6514 | sa_covered, | |
6515 | sa_domainspan, | |
6516 | #endif | |
6517 | sa_none, | |
6518 | }; | |
6519 | ||
9c1cfda2 | 6520 | /* |
48f24c4d | 6521 | * SMT sched-domains: |
9c1cfda2 | 6522 | */ |
1da177e4 | 6523 | #ifdef CONFIG_SCHED_SMT |
6c99e9ad | 6524 | static DEFINE_PER_CPU(struct static_sched_domain, cpu_domains); |
1871e52c | 6525 | static DEFINE_PER_CPU(struct static_sched_group, sched_groups); |
48f24c4d | 6526 | |
41a2d6cf | 6527 | static int |
96f874e2 RR |
6528 | cpu_to_cpu_group(int cpu, const struct cpumask *cpu_map, |
6529 | struct sched_group **sg, struct cpumask *unused) | |
1da177e4 | 6530 | { |
6711cab4 | 6531 | if (sg) |
1871e52c | 6532 | *sg = &per_cpu(sched_groups, cpu).sg; |
1da177e4 LT |
6533 | return cpu; |
6534 | } | |
6d6bc0ad | 6535 | #endif /* CONFIG_SCHED_SMT */ |
1da177e4 | 6536 | |
48f24c4d IM |
6537 | /* |
6538 | * multi-core sched-domains: | |
6539 | */ | |
1e9f28fa | 6540 | #ifdef CONFIG_SCHED_MC |
6c99e9ad RR |
6541 | static DEFINE_PER_CPU(struct static_sched_domain, core_domains); |
6542 | static DEFINE_PER_CPU(struct static_sched_group, sched_group_core); | |
6d6bc0ad | 6543 | #endif /* CONFIG_SCHED_MC */ |
1e9f28fa SS |
6544 | |
6545 | #if defined(CONFIG_SCHED_MC) && defined(CONFIG_SCHED_SMT) | |
41a2d6cf | 6546 | static int |
96f874e2 RR |
6547 | cpu_to_core_group(int cpu, const struct cpumask *cpu_map, |
6548 | struct sched_group **sg, struct cpumask *mask) | |
1e9f28fa | 6549 | { |
6711cab4 | 6550 | int group; |
7c16ec58 | 6551 | |
c69fc56d | 6552 | cpumask_and(mask, topology_thread_cpumask(cpu), cpu_map); |
96f874e2 | 6553 | group = cpumask_first(mask); |
6711cab4 | 6554 | if (sg) |
6c99e9ad | 6555 | *sg = &per_cpu(sched_group_core, group).sg; |
6711cab4 | 6556 | return group; |
1e9f28fa SS |
6557 | } |
6558 | #elif defined(CONFIG_SCHED_MC) | |
41a2d6cf | 6559 | static int |
96f874e2 RR |
6560 | cpu_to_core_group(int cpu, const struct cpumask *cpu_map, |
6561 | struct sched_group **sg, struct cpumask *unused) | |
1e9f28fa | 6562 | { |
6711cab4 | 6563 | if (sg) |
6c99e9ad | 6564 | *sg = &per_cpu(sched_group_core, cpu).sg; |
1e9f28fa SS |
6565 | return cpu; |
6566 | } | |
6567 | #endif | |
6568 | ||
6c99e9ad RR |
6569 | static DEFINE_PER_CPU(struct static_sched_domain, phys_domains); |
6570 | static DEFINE_PER_CPU(struct static_sched_group, sched_group_phys); | |
48f24c4d | 6571 | |
41a2d6cf | 6572 | static int |
96f874e2 RR |
6573 | cpu_to_phys_group(int cpu, const struct cpumask *cpu_map, |
6574 | struct sched_group **sg, struct cpumask *mask) | |
1da177e4 | 6575 | { |
6711cab4 | 6576 | int group; |
48f24c4d | 6577 | #ifdef CONFIG_SCHED_MC |
6ca09dfc | 6578 | cpumask_and(mask, cpu_coregroup_mask(cpu), cpu_map); |
96f874e2 | 6579 | group = cpumask_first(mask); |
1e9f28fa | 6580 | #elif defined(CONFIG_SCHED_SMT) |
c69fc56d | 6581 | cpumask_and(mask, topology_thread_cpumask(cpu), cpu_map); |
96f874e2 | 6582 | group = cpumask_first(mask); |
1da177e4 | 6583 | #else |
6711cab4 | 6584 | group = cpu; |
1da177e4 | 6585 | #endif |
6711cab4 | 6586 | if (sg) |
6c99e9ad | 6587 | *sg = &per_cpu(sched_group_phys, group).sg; |
6711cab4 | 6588 | return group; |
1da177e4 LT |
6589 | } |
6590 | ||
6591 | #ifdef CONFIG_NUMA | |
1da177e4 | 6592 | /* |
9c1cfda2 JH |
6593 | * The init_sched_build_groups can't handle what we want to do with node |
6594 | * groups, so roll our own. Now each node has its own list of groups which | |
6595 | * gets dynamically allocated. | |
1da177e4 | 6596 | */ |
62ea9ceb | 6597 | static DEFINE_PER_CPU(struct static_sched_domain, node_domains); |
434d53b0 | 6598 | static struct sched_group ***sched_group_nodes_bycpu; |
1da177e4 | 6599 | |
62ea9ceb | 6600 | static DEFINE_PER_CPU(struct static_sched_domain, allnodes_domains); |
6c99e9ad | 6601 | static DEFINE_PER_CPU(struct static_sched_group, sched_group_allnodes); |
9c1cfda2 | 6602 | |
96f874e2 RR |
6603 | static int cpu_to_allnodes_group(int cpu, const struct cpumask *cpu_map, |
6604 | struct sched_group **sg, | |
6605 | struct cpumask *nodemask) | |
9c1cfda2 | 6606 | { |
6711cab4 SS |
6607 | int group; |
6608 | ||
6ca09dfc | 6609 | cpumask_and(nodemask, cpumask_of_node(cpu_to_node(cpu)), cpu_map); |
96f874e2 | 6610 | group = cpumask_first(nodemask); |
6711cab4 SS |
6611 | |
6612 | if (sg) | |
6c99e9ad | 6613 | *sg = &per_cpu(sched_group_allnodes, group).sg; |
6711cab4 | 6614 | return group; |
1da177e4 | 6615 | } |
6711cab4 | 6616 | |
08069033 SS |
6617 | static void init_numa_sched_groups_power(struct sched_group *group_head) |
6618 | { | |
6619 | struct sched_group *sg = group_head; | |
6620 | int j; | |
6621 | ||
6622 | if (!sg) | |
6623 | return; | |
3a5c359a | 6624 | do { |
758b2cdc | 6625 | for_each_cpu(j, sched_group_cpus(sg)) { |
3a5c359a | 6626 | struct sched_domain *sd; |
08069033 | 6627 | |
6c99e9ad | 6628 | sd = &per_cpu(phys_domains, j).sd; |
13318a71 | 6629 | if (j != group_first_cpu(sd->groups)) { |
3a5c359a AK |
6630 | /* |
6631 | * Only add "power" once for each | |
6632 | * physical package. | |
6633 | */ | |
6634 | continue; | |
6635 | } | |
08069033 | 6636 | |
18a3885f | 6637 | sg->cpu_power += sd->groups->cpu_power; |
3a5c359a AK |
6638 | } |
6639 | sg = sg->next; | |
6640 | } while (sg != group_head); | |
08069033 | 6641 | } |
0601a88d AH |
6642 | |
6643 | static int build_numa_sched_groups(struct s_data *d, | |
6644 | const struct cpumask *cpu_map, int num) | |
6645 | { | |
6646 | struct sched_domain *sd; | |
6647 | struct sched_group *sg, *prev; | |
6648 | int n, j; | |
6649 | ||
6650 | cpumask_clear(d->covered); | |
6651 | cpumask_and(d->nodemask, cpumask_of_node(num), cpu_map); | |
6652 | if (cpumask_empty(d->nodemask)) { | |
6653 | d->sched_group_nodes[num] = NULL; | |
6654 | goto out; | |
6655 | } | |
6656 | ||
6657 | sched_domain_node_span(num, d->domainspan); | |
6658 | cpumask_and(d->domainspan, d->domainspan, cpu_map); | |
6659 | ||
6660 | sg = kmalloc_node(sizeof(struct sched_group) + cpumask_size(), | |
6661 | GFP_KERNEL, num); | |
6662 | if (!sg) { | |
3df0fc5b PZ |
6663 | printk(KERN_WARNING "Can not alloc domain group for node %d\n", |
6664 | num); | |
0601a88d AH |
6665 | return -ENOMEM; |
6666 | } | |
6667 | d->sched_group_nodes[num] = sg; | |
6668 | ||
6669 | for_each_cpu(j, d->nodemask) { | |
6670 | sd = &per_cpu(node_domains, j).sd; | |
6671 | sd->groups = sg; | |
6672 | } | |
6673 | ||
18a3885f | 6674 | sg->cpu_power = 0; |
0601a88d AH |
6675 | cpumask_copy(sched_group_cpus(sg), d->nodemask); |
6676 | sg->next = sg; | |
6677 | cpumask_or(d->covered, d->covered, d->nodemask); | |
6678 | ||
6679 | prev = sg; | |
6680 | for (j = 0; j < nr_node_ids; j++) { | |
6681 | n = (num + j) % nr_node_ids; | |
6682 | cpumask_complement(d->notcovered, d->covered); | |
6683 | cpumask_and(d->tmpmask, d->notcovered, cpu_map); | |
6684 | cpumask_and(d->tmpmask, d->tmpmask, d->domainspan); | |
6685 | if (cpumask_empty(d->tmpmask)) | |
6686 | break; | |
6687 | cpumask_and(d->tmpmask, d->tmpmask, cpumask_of_node(n)); | |
6688 | if (cpumask_empty(d->tmpmask)) | |
6689 | continue; | |
6690 | sg = kmalloc_node(sizeof(struct sched_group) + cpumask_size(), | |
6691 | GFP_KERNEL, num); | |
6692 | if (!sg) { | |
3df0fc5b PZ |
6693 | printk(KERN_WARNING |
6694 | "Can not alloc domain group for node %d\n", j); | |
0601a88d AH |
6695 | return -ENOMEM; |
6696 | } | |
18a3885f | 6697 | sg->cpu_power = 0; |
0601a88d AH |
6698 | cpumask_copy(sched_group_cpus(sg), d->tmpmask); |
6699 | sg->next = prev->next; | |
6700 | cpumask_or(d->covered, d->covered, d->tmpmask); | |
6701 | prev->next = sg; | |
6702 | prev = sg; | |
6703 | } | |
6704 | out: | |
6705 | return 0; | |
6706 | } | |
6d6bc0ad | 6707 | #endif /* CONFIG_NUMA */ |
1da177e4 | 6708 | |
a616058b | 6709 | #ifdef CONFIG_NUMA |
51888ca2 | 6710 | /* Free memory allocated for various sched_group structures */ |
96f874e2 RR |
6711 | static void free_sched_groups(const struct cpumask *cpu_map, |
6712 | struct cpumask *nodemask) | |
51888ca2 | 6713 | { |
a616058b | 6714 | int cpu, i; |
51888ca2 | 6715 | |
abcd083a | 6716 | for_each_cpu(cpu, cpu_map) { |
51888ca2 SV |
6717 | struct sched_group **sched_group_nodes |
6718 | = sched_group_nodes_bycpu[cpu]; | |
6719 | ||
51888ca2 SV |
6720 | if (!sched_group_nodes) |
6721 | continue; | |
6722 | ||
076ac2af | 6723 | for (i = 0; i < nr_node_ids; i++) { |
51888ca2 SV |
6724 | struct sched_group *oldsg, *sg = sched_group_nodes[i]; |
6725 | ||
6ca09dfc | 6726 | cpumask_and(nodemask, cpumask_of_node(i), cpu_map); |
96f874e2 | 6727 | if (cpumask_empty(nodemask)) |
51888ca2 SV |
6728 | continue; |
6729 | ||
6730 | if (sg == NULL) | |
6731 | continue; | |
6732 | sg = sg->next; | |
6733 | next_sg: | |
6734 | oldsg = sg; | |
6735 | sg = sg->next; | |
6736 | kfree(oldsg); | |
6737 | if (oldsg != sched_group_nodes[i]) | |
6738 | goto next_sg; | |
6739 | } | |
6740 | kfree(sched_group_nodes); | |
6741 | sched_group_nodes_bycpu[cpu] = NULL; | |
6742 | } | |
51888ca2 | 6743 | } |
6d6bc0ad | 6744 | #else /* !CONFIG_NUMA */ |
96f874e2 RR |
6745 | static void free_sched_groups(const struct cpumask *cpu_map, |
6746 | struct cpumask *nodemask) | |
a616058b SS |
6747 | { |
6748 | } | |
6d6bc0ad | 6749 | #endif /* CONFIG_NUMA */ |
51888ca2 | 6750 | |
89c4710e SS |
6751 | /* |
6752 | * Initialize sched groups cpu_power. | |
6753 | * | |
6754 | * cpu_power indicates the capacity of sched group, which is used while | |
6755 | * distributing the load between different sched groups in a sched domain. | |
6756 | * Typically cpu_power for all the groups in a sched domain will be same unless | |
6757 | * there are asymmetries in the topology. If there are asymmetries, group | |
6758 | * having more cpu_power will pickup more load compared to the group having | |
6759 | * less cpu_power. | |
89c4710e SS |
6760 | */ |
6761 | static void init_sched_groups_power(int cpu, struct sched_domain *sd) | |
6762 | { | |
6763 | struct sched_domain *child; | |
6764 | struct sched_group *group; | |
f93e65c1 PZ |
6765 | long power; |
6766 | int weight; | |
89c4710e SS |
6767 | |
6768 | WARN_ON(!sd || !sd->groups); | |
6769 | ||
13318a71 | 6770 | if (cpu != group_first_cpu(sd->groups)) |
89c4710e SS |
6771 | return; |
6772 | ||
6773 | child = sd->child; | |
6774 | ||
18a3885f | 6775 | sd->groups->cpu_power = 0; |
5517d86b | 6776 | |
f93e65c1 PZ |
6777 | if (!child) { |
6778 | power = SCHED_LOAD_SCALE; | |
6779 | weight = cpumask_weight(sched_domain_span(sd)); | |
6780 | /* | |
6781 | * SMT siblings share the power of a single core. | |
a52bfd73 PZ |
6782 | * Usually multiple threads get a better yield out of |
6783 | * that one core than a single thread would have, | |
6784 | * reflect that in sd->smt_gain. | |
f93e65c1 | 6785 | */ |
a52bfd73 PZ |
6786 | if ((sd->flags & SD_SHARE_CPUPOWER) && weight > 1) { |
6787 | power *= sd->smt_gain; | |
f93e65c1 | 6788 | power /= weight; |
a52bfd73 PZ |
6789 | power >>= SCHED_LOAD_SHIFT; |
6790 | } | |
18a3885f | 6791 | sd->groups->cpu_power += power; |
89c4710e SS |
6792 | return; |
6793 | } | |
6794 | ||
89c4710e | 6795 | /* |
f93e65c1 | 6796 | * Add cpu_power of each child group to this groups cpu_power. |
89c4710e SS |
6797 | */ |
6798 | group = child->groups; | |
6799 | do { | |
18a3885f | 6800 | sd->groups->cpu_power += group->cpu_power; |
89c4710e SS |
6801 | group = group->next; |
6802 | } while (group != child->groups); | |
6803 | } | |
6804 | ||
7c16ec58 MT |
6805 | /* |
6806 | * Initializers for schedule domains | |
6807 | * Non-inlined to reduce accumulated stack pressure in build_sched_domains() | |
6808 | */ | |
6809 | ||
a5d8c348 IM |
6810 | #ifdef CONFIG_SCHED_DEBUG |
6811 | # define SD_INIT_NAME(sd, type) sd->name = #type | |
6812 | #else | |
6813 | # define SD_INIT_NAME(sd, type) do { } while (0) | |
6814 | #endif | |
6815 | ||
7c16ec58 | 6816 | #define SD_INIT(sd, type) sd_init_##type(sd) |
a5d8c348 | 6817 | |
7c16ec58 MT |
6818 | #define SD_INIT_FUNC(type) \ |
6819 | static noinline void sd_init_##type(struct sched_domain *sd) \ | |
6820 | { \ | |
6821 | memset(sd, 0, sizeof(*sd)); \ | |
6822 | *sd = SD_##type##_INIT; \ | |
1d3504fc | 6823 | sd->level = SD_LV_##type; \ |
a5d8c348 | 6824 | SD_INIT_NAME(sd, type); \ |
7c16ec58 MT |
6825 | } |
6826 | ||
6827 | SD_INIT_FUNC(CPU) | |
6828 | #ifdef CONFIG_NUMA | |
6829 | SD_INIT_FUNC(ALLNODES) | |
6830 | SD_INIT_FUNC(NODE) | |
6831 | #endif | |
6832 | #ifdef CONFIG_SCHED_SMT | |
6833 | SD_INIT_FUNC(SIBLING) | |
6834 | #endif | |
6835 | #ifdef CONFIG_SCHED_MC | |
6836 | SD_INIT_FUNC(MC) | |
6837 | #endif | |
6838 | ||
1d3504fc HS |
6839 | static int default_relax_domain_level = -1; |
6840 | ||
6841 | static int __init setup_relax_domain_level(char *str) | |
6842 | { | |
30e0e178 LZ |
6843 | unsigned long val; |
6844 | ||
6845 | val = simple_strtoul(str, NULL, 0); | |
6846 | if (val < SD_LV_MAX) | |
6847 | default_relax_domain_level = val; | |
6848 | ||
1d3504fc HS |
6849 | return 1; |
6850 | } | |
6851 | __setup("relax_domain_level=", setup_relax_domain_level); | |
6852 | ||
6853 | static void set_domain_attribute(struct sched_domain *sd, | |
6854 | struct sched_domain_attr *attr) | |
6855 | { | |
6856 | int request; | |
6857 | ||
6858 | if (!attr || attr->relax_domain_level < 0) { | |
6859 | if (default_relax_domain_level < 0) | |
6860 | return; | |
6861 | else | |
6862 | request = default_relax_domain_level; | |
6863 | } else | |
6864 | request = attr->relax_domain_level; | |
6865 | if (request < sd->level) { | |
6866 | /* turn off idle balance on this domain */ | |
c88d5910 | 6867 | sd->flags &= ~(SD_BALANCE_WAKE|SD_BALANCE_NEWIDLE); |
1d3504fc HS |
6868 | } else { |
6869 | /* turn on idle balance on this domain */ | |
c88d5910 | 6870 | sd->flags |= (SD_BALANCE_WAKE|SD_BALANCE_NEWIDLE); |
1d3504fc HS |
6871 | } |
6872 | } | |
6873 | ||
2109b99e AH |
6874 | static void __free_domain_allocs(struct s_data *d, enum s_alloc what, |
6875 | const struct cpumask *cpu_map) | |
6876 | { | |
6877 | switch (what) { | |
6878 | case sa_sched_groups: | |
6879 | free_sched_groups(cpu_map, d->tmpmask); /* fall through */ | |
6880 | d->sched_group_nodes = NULL; | |
6881 | case sa_rootdomain: | |
6882 | free_rootdomain(d->rd); /* fall through */ | |
6883 | case sa_tmpmask: | |
6884 | free_cpumask_var(d->tmpmask); /* fall through */ | |
6885 | case sa_send_covered: | |
6886 | free_cpumask_var(d->send_covered); /* fall through */ | |
6887 | case sa_this_core_map: | |
6888 | free_cpumask_var(d->this_core_map); /* fall through */ | |
6889 | case sa_this_sibling_map: | |
6890 | free_cpumask_var(d->this_sibling_map); /* fall through */ | |
6891 | case sa_nodemask: | |
6892 | free_cpumask_var(d->nodemask); /* fall through */ | |
6893 | case sa_sched_group_nodes: | |
d1b55138 | 6894 | #ifdef CONFIG_NUMA |
2109b99e AH |
6895 | kfree(d->sched_group_nodes); /* fall through */ |
6896 | case sa_notcovered: | |
6897 | free_cpumask_var(d->notcovered); /* fall through */ | |
6898 | case sa_covered: | |
6899 | free_cpumask_var(d->covered); /* fall through */ | |
6900 | case sa_domainspan: | |
6901 | free_cpumask_var(d->domainspan); /* fall through */ | |
3404c8d9 | 6902 | #endif |
2109b99e AH |
6903 | case sa_none: |
6904 | break; | |
6905 | } | |
6906 | } | |
3404c8d9 | 6907 | |
2109b99e AH |
6908 | static enum s_alloc __visit_domain_allocation_hell(struct s_data *d, |
6909 | const struct cpumask *cpu_map) | |
6910 | { | |
3404c8d9 | 6911 | #ifdef CONFIG_NUMA |
2109b99e AH |
6912 | if (!alloc_cpumask_var(&d->domainspan, GFP_KERNEL)) |
6913 | return sa_none; | |
6914 | if (!alloc_cpumask_var(&d->covered, GFP_KERNEL)) | |
6915 | return sa_domainspan; | |
6916 | if (!alloc_cpumask_var(&d->notcovered, GFP_KERNEL)) | |
6917 | return sa_covered; | |
6918 | /* Allocate the per-node list of sched groups */ | |
6919 | d->sched_group_nodes = kcalloc(nr_node_ids, | |
6920 | sizeof(struct sched_group *), GFP_KERNEL); | |
6921 | if (!d->sched_group_nodes) { | |
3df0fc5b | 6922 | printk(KERN_WARNING "Can not alloc sched group node list\n"); |
2109b99e | 6923 | return sa_notcovered; |
d1b55138 | 6924 | } |
2109b99e | 6925 | sched_group_nodes_bycpu[cpumask_first(cpu_map)] = d->sched_group_nodes; |
d1b55138 | 6926 | #endif |
2109b99e AH |
6927 | if (!alloc_cpumask_var(&d->nodemask, GFP_KERNEL)) |
6928 | return sa_sched_group_nodes; | |
6929 | if (!alloc_cpumask_var(&d->this_sibling_map, GFP_KERNEL)) | |
6930 | return sa_nodemask; | |
6931 | if (!alloc_cpumask_var(&d->this_core_map, GFP_KERNEL)) | |
6932 | return sa_this_sibling_map; | |
6933 | if (!alloc_cpumask_var(&d->send_covered, GFP_KERNEL)) | |
6934 | return sa_this_core_map; | |
6935 | if (!alloc_cpumask_var(&d->tmpmask, GFP_KERNEL)) | |
6936 | return sa_send_covered; | |
6937 | d->rd = alloc_rootdomain(); | |
6938 | if (!d->rd) { | |
3df0fc5b | 6939 | printk(KERN_WARNING "Cannot alloc root domain\n"); |
2109b99e | 6940 | return sa_tmpmask; |
57d885fe | 6941 | } |
2109b99e AH |
6942 | return sa_rootdomain; |
6943 | } | |
57d885fe | 6944 | |
7f4588f3 AH |
6945 | static struct sched_domain *__build_numa_sched_domains(struct s_data *d, |
6946 | const struct cpumask *cpu_map, struct sched_domain_attr *attr, int i) | |
6947 | { | |
6948 | struct sched_domain *sd = NULL; | |
7c16ec58 | 6949 | #ifdef CONFIG_NUMA |
7f4588f3 | 6950 | struct sched_domain *parent; |
1da177e4 | 6951 | |
7f4588f3 AH |
6952 | d->sd_allnodes = 0; |
6953 | if (cpumask_weight(cpu_map) > | |
6954 | SD_NODES_PER_DOMAIN * cpumask_weight(d->nodemask)) { | |
6955 | sd = &per_cpu(allnodes_domains, i).sd; | |
6956 | SD_INIT(sd, ALLNODES); | |
1d3504fc | 6957 | set_domain_attribute(sd, attr); |
7f4588f3 AH |
6958 | cpumask_copy(sched_domain_span(sd), cpu_map); |
6959 | cpu_to_allnodes_group(i, cpu_map, &sd->groups, d->tmpmask); | |
6960 | d->sd_allnodes = 1; | |
6961 | } | |
6962 | parent = sd; | |
6963 | ||
6964 | sd = &per_cpu(node_domains, i).sd; | |
6965 | SD_INIT(sd, NODE); | |
6966 | set_domain_attribute(sd, attr); | |
6967 | sched_domain_node_span(cpu_to_node(i), sched_domain_span(sd)); | |
6968 | sd->parent = parent; | |
6969 | if (parent) | |
6970 | parent->child = sd; | |
6971 | cpumask_and(sched_domain_span(sd), sched_domain_span(sd), cpu_map); | |
1da177e4 | 6972 | #endif |
7f4588f3 AH |
6973 | return sd; |
6974 | } | |
1da177e4 | 6975 | |
87cce662 AH |
6976 | static struct sched_domain *__build_cpu_sched_domain(struct s_data *d, |
6977 | const struct cpumask *cpu_map, struct sched_domain_attr *attr, | |
6978 | struct sched_domain *parent, int i) | |
6979 | { | |
6980 | struct sched_domain *sd; | |
6981 | sd = &per_cpu(phys_domains, i).sd; | |
6982 | SD_INIT(sd, CPU); | |
6983 | set_domain_attribute(sd, attr); | |
6984 | cpumask_copy(sched_domain_span(sd), d->nodemask); | |
6985 | sd->parent = parent; | |
6986 | if (parent) | |
6987 | parent->child = sd; | |
6988 | cpu_to_phys_group(i, cpu_map, &sd->groups, d->tmpmask); | |
6989 | return sd; | |
6990 | } | |
1da177e4 | 6991 | |
410c4081 AH |
6992 | static struct sched_domain *__build_mc_sched_domain(struct s_data *d, |
6993 | const struct cpumask *cpu_map, struct sched_domain_attr *attr, | |
6994 | struct sched_domain *parent, int i) | |
6995 | { | |
6996 | struct sched_domain *sd = parent; | |
1e9f28fa | 6997 | #ifdef CONFIG_SCHED_MC |
410c4081 AH |
6998 | sd = &per_cpu(core_domains, i).sd; |
6999 | SD_INIT(sd, MC); | |
7000 | set_domain_attribute(sd, attr); | |
7001 | cpumask_and(sched_domain_span(sd), cpu_map, cpu_coregroup_mask(i)); | |
7002 | sd->parent = parent; | |
7003 | parent->child = sd; | |
7004 | cpu_to_core_group(i, cpu_map, &sd->groups, d->tmpmask); | |
1e9f28fa | 7005 | #endif |
410c4081 AH |
7006 | return sd; |
7007 | } | |
1e9f28fa | 7008 | |
d8173535 AH |
7009 | static struct sched_domain *__build_smt_sched_domain(struct s_data *d, |
7010 | const struct cpumask *cpu_map, struct sched_domain_attr *attr, | |
7011 | struct sched_domain *parent, int i) | |
7012 | { | |
7013 | struct sched_domain *sd = parent; | |
1da177e4 | 7014 | #ifdef CONFIG_SCHED_SMT |
d8173535 AH |
7015 | sd = &per_cpu(cpu_domains, i).sd; |
7016 | SD_INIT(sd, SIBLING); | |
7017 | set_domain_attribute(sd, attr); | |
7018 | cpumask_and(sched_domain_span(sd), cpu_map, topology_thread_cpumask(i)); | |
7019 | sd->parent = parent; | |
7020 | parent->child = sd; | |
7021 | cpu_to_cpu_group(i, cpu_map, &sd->groups, d->tmpmask); | |
1da177e4 | 7022 | #endif |
d8173535 AH |
7023 | return sd; |
7024 | } | |
1da177e4 | 7025 | |
0e8e85c9 AH |
7026 | static void build_sched_groups(struct s_data *d, enum sched_domain_level l, |
7027 | const struct cpumask *cpu_map, int cpu) | |
7028 | { | |
7029 | switch (l) { | |
1da177e4 | 7030 | #ifdef CONFIG_SCHED_SMT |
0e8e85c9 AH |
7031 | case SD_LV_SIBLING: /* set up CPU (sibling) groups */ |
7032 | cpumask_and(d->this_sibling_map, cpu_map, | |
7033 | topology_thread_cpumask(cpu)); | |
7034 | if (cpu == cpumask_first(d->this_sibling_map)) | |
7035 | init_sched_build_groups(d->this_sibling_map, cpu_map, | |
7036 | &cpu_to_cpu_group, | |
7037 | d->send_covered, d->tmpmask); | |
7038 | break; | |
1da177e4 | 7039 | #endif |
1e9f28fa | 7040 | #ifdef CONFIG_SCHED_MC |
a2af04cd AH |
7041 | case SD_LV_MC: /* set up multi-core groups */ |
7042 | cpumask_and(d->this_core_map, cpu_map, cpu_coregroup_mask(cpu)); | |
7043 | if (cpu == cpumask_first(d->this_core_map)) | |
7044 | init_sched_build_groups(d->this_core_map, cpu_map, | |
7045 | &cpu_to_core_group, | |
7046 | d->send_covered, d->tmpmask); | |
7047 | break; | |
1e9f28fa | 7048 | #endif |
86548096 AH |
7049 | case SD_LV_CPU: /* set up physical groups */ |
7050 | cpumask_and(d->nodemask, cpumask_of_node(cpu), cpu_map); | |
7051 | if (!cpumask_empty(d->nodemask)) | |
7052 | init_sched_build_groups(d->nodemask, cpu_map, | |
7053 | &cpu_to_phys_group, | |
7054 | d->send_covered, d->tmpmask); | |
7055 | break; | |
1da177e4 | 7056 | #ifdef CONFIG_NUMA |
de616e36 AH |
7057 | case SD_LV_ALLNODES: |
7058 | init_sched_build_groups(cpu_map, cpu_map, &cpu_to_allnodes_group, | |
7059 | d->send_covered, d->tmpmask); | |
7060 | break; | |
7061 | #endif | |
0e8e85c9 AH |
7062 | default: |
7063 | break; | |
7c16ec58 | 7064 | } |
0e8e85c9 | 7065 | } |
9c1cfda2 | 7066 | |
2109b99e AH |
7067 | /* |
7068 | * Build sched domains for a given set of cpus and attach the sched domains | |
7069 | * to the individual cpus | |
7070 | */ | |
7071 | static int __build_sched_domains(const struct cpumask *cpu_map, | |
7072 | struct sched_domain_attr *attr) | |
7073 | { | |
7074 | enum s_alloc alloc_state = sa_none; | |
7075 | struct s_data d; | |
294b0c96 | 7076 | struct sched_domain *sd; |
2109b99e | 7077 | int i; |
7c16ec58 | 7078 | #ifdef CONFIG_NUMA |
2109b99e | 7079 | d.sd_allnodes = 0; |
7c16ec58 | 7080 | #endif |
9c1cfda2 | 7081 | |
2109b99e AH |
7082 | alloc_state = __visit_domain_allocation_hell(&d, cpu_map); |
7083 | if (alloc_state != sa_rootdomain) | |
7084 | goto error; | |
7085 | alloc_state = sa_sched_groups; | |
9c1cfda2 | 7086 | |
1da177e4 | 7087 | /* |
1a20ff27 | 7088 | * Set up domains for cpus specified by the cpu_map. |
1da177e4 | 7089 | */ |
abcd083a | 7090 | for_each_cpu(i, cpu_map) { |
49a02c51 AH |
7091 | cpumask_and(d.nodemask, cpumask_of_node(cpu_to_node(i)), |
7092 | cpu_map); | |
9761eea8 | 7093 | |
7f4588f3 | 7094 | sd = __build_numa_sched_domains(&d, cpu_map, attr, i); |
87cce662 | 7095 | sd = __build_cpu_sched_domain(&d, cpu_map, attr, sd, i); |
410c4081 | 7096 | sd = __build_mc_sched_domain(&d, cpu_map, attr, sd, i); |
d8173535 | 7097 | sd = __build_smt_sched_domain(&d, cpu_map, attr, sd, i); |
1da177e4 | 7098 | } |
9c1cfda2 | 7099 | |
abcd083a | 7100 | for_each_cpu(i, cpu_map) { |
0e8e85c9 | 7101 | build_sched_groups(&d, SD_LV_SIBLING, cpu_map, i); |
a2af04cd | 7102 | build_sched_groups(&d, SD_LV_MC, cpu_map, i); |
1da177e4 | 7103 | } |
9c1cfda2 | 7104 | |
1da177e4 | 7105 | /* Set up physical groups */ |
86548096 AH |
7106 | for (i = 0; i < nr_node_ids; i++) |
7107 | build_sched_groups(&d, SD_LV_CPU, cpu_map, i); | |
9c1cfda2 | 7108 | |
1da177e4 LT |
7109 | #ifdef CONFIG_NUMA |
7110 | /* Set up node groups */ | |
de616e36 AH |
7111 | if (d.sd_allnodes) |
7112 | build_sched_groups(&d, SD_LV_ALLNODES, cpu_map, 0); | |
9c1cfda2 | 7113 | |
0601a88d AH |
7114 | for (i = 0; i < nr_node_ids; i++) |
7115 | if (build_numa_sched_groups(&d, cpu_map, i)) | |
51888ca2 | 7116 | goto error; |
1da177e4 LT |
7117 | #endif |
7118 | ||
7119 | /* Calculate CPU power for physical packages and nodes */ | |
5c45bf27 | 7120 | #ifdef CONFIG_SCHED_SMT |
abcd083a | 7121 | for_each_cpu(i, cpu_map) { |
294b0c96 | 7122 | sd = &per_cpu(cpu_domains, i).sd; |
89c4710e | 7123 | init_sched_groups_power(i, sd); |
5c45bf27 | 7124 | } |
1da177e4 | 7125 | #endif |
1e9f28fa | 7126 | #ifdef CONFIG_SCHED_MC |
abcd083a | 7127 | for_each_cpu(i, cpu_map) { |
294b0c96 | 7128 | sd = &per_cpu(core_domains, i).sd; |
89c4710e | 7129 | init_sched_groups_power(i, sd); |
5c45bf27 SS |
7130 | } |
7131 | #endif | |
1e9f28fa | 7132 | |
abcd083a | 7133 | for_each_cpu(i, cpu_map) { |
294b0c96 | 7134 | sd = &per_cpu(phys_domains, i).sd; |
89c4710e | 7135 | init_sched_groups_power(i, sd); |
1da177e4 LT |
7136 | } |
7137 | ||
9c1cfda2 | 7138 | #ifdef CONFIG_NUMA |
076ac2af | 7139 | for (i = 0; i < nr_node_ids; i++) |
49a02c51 | 7140 | init_numa_sched_groups_power(d.sched_group_nodes[i]); |
9c1cfda2 | 7141 | |
49a02c51 | 7142 | if (d.sd_allnodes) { |
6711cab4 | 7143 | struct sched_group *sg; |
f712c0c7 | 7144 | |
96f874e2 | 7145 | cpu_to_allnodes_group(cpumask_first(cpu_map), cpu_map, &sg, |
49a02c51 | 7146 | d.tmpmask); |
f712c0c7 SS |
7147 | init_numa_sched_groups_power(sg); |
7148 | } | |
9c1cfda2 JH |
7149 | #endif |
7150 | ||
1da177e4 | 7151 | /* Attach the domains */ |
abcd083a | 7152 | for_each_cpu(i, cpu_map) { |
1da177e4 | 7153 | #ifdef CONFIG_SCHED_SMT |
6c99e9ad | 7154 | sd = &per_cpu(cpu_domains, i).sd; |
1e9f28fa | 7155 | #elif defined(CONFIG_SCHED_MC) |
6c99e9ad | 7156 | sd = &per_cpu(core_domains, i).sd; |
1da177e4 | 7157 | #else |
6c99e9ad | 7158 | sd = &per_cpu(phys_domains, i).sd; |
1da177e4 | 7159 | #endif |
49a02c51 | 7160 | cpu_attach_domain(sd, d.rd, i); |
1da177e4 | 7161 | } |
51888ca2 | 7162 | |
2109b99e AH |
7163 | d.sched_group_nodes = NULL; /* don't free this we still need it */ |
7164 | __free_domain_allocs(&d, sa_tmpmask, cpu_map); | |
7165 | return 0; | |
51888ca2 | 7166 | |
51888ca2 | 7167 | error: |
2109b99e AH |
7168 | __free_domain_allocs(&d, alloc_state, cpu_map); |
7169 | return -ENOMEM; | |
1da177e4 | 7170 | } |
029190c5 | 7171 | |
96f874e2 | 7172 | static int build_sched_domains(const struct cpumask *cpu_map) |
1d3504fc HS |
7173 | { |
7174 | return __build_sched_domains(cpu_map, NULL); | |
7175 | } | |
7176 | ||
acc3f5d7 | 7177 | static cpumask_var_t *doms_cur; /* current sched domains */ |
029190c5 | 7178 | static int ndoms_cur; /* number of sched domains in 'doms_cur' */ |
4285f594 IM |
7179 | static struct sched_domain_attr *dattr_cur; |
7180 | /* attribues of custom domains in 'doms_cur' */ | |
029190c5 PJ |
7181 | |
7182 | /* | |
7183 | * Special case: If a kmalloc of a doms_cur partition (array of | |
4212823f RR |
7184 | * cpumask) fails, then fallback to a single sched domain, |
7185 | * as determined by the single cpumask fallback_doms. | |
029190c5 | 7186 | */ |
4212823f | 7187 | static cpumask_var_t fallback_doms; |
029190c5 | 7188 | |
ee79d1bd HC |
7189 | /* |
7190 | * arch_update_cpu_topology lets virtualized architectures update the | |
7191 | * cpu core maps. It is supposed to return 1 if the topology changed | |
7192 | * or 0 if it stayed the same. | |
7193 | */ | |
7194 | int __attribute__((weak)) arch_update_cpu_topology(void) | |
22e52b07 | 7195 | { |
ee79d1bd | 7196 | return 0; |
22e52b07 HC |
7197 | } |
7198 | ||
acc3f5d7 RR |
7199 | cpumask_var_t *alloc_sched_domains(unsigned int ndoms) |
7200 | { | |
7201 | int i; | |
7202 | cpumask_var_t *doms; | |
7203 | ||
7204 | doms = kmalloc(sizeof(*doms) * ndoms, GFP_KERNEL); | |
7205 | if (!doms) | |
7206 | return NULL; | |
7207 | for (i = 0; i < ndoms; i++) { | |
7208 | if (!alloc_cpumask_var(&doms[i], GFP_KERNEL)) { | |
7209 | free_sched_domains(doms, i); | |
7210 | return NULL; | |
7211 | } | |
7212 | } | |
7213 | return doms; | |
7214 | } | |
7215 | ||
7216 | void free_sched_domains(cpumask_var_t doms[], unsigned int ndoms) | |
7217 | { | |
7218 | unsigned int i; | |
7219 | for (i = 0; i < ndoms; i++) | |
7220 | free_cpumask_var(doms[i]); | |
7221 | kfree(doms); | |
7222 | } | |
7223 | ||
1a20ff27 | 7224 | /* |
41a2d6cf | 7225 | * Set up scheduler domains and groups. Callers must hold the hotplug lock. |
029190c5 PJ |
7226 | * For now this just excludes isolated cpus, but could be used to |
7227 | * exclude other special cases in the future. | |
1a20ff27 | 7228 | */ |
96f874e2 | 7229 | static int arch_init_sched_domains(const struct cpumask *cpu_map) |
1a20ff27 | 7230 | { |
7378547f MM |
7231 | int err; |
7232 | ||
22e52b07 | 7233 | arch_update_cpu_topology(); |
029190c5 | 7234 | ndoms_cur = 1; |
acc3f5d7 | 7235 | doms_cur = alloc_sched_domains(ndoms_cur); |
029190c5 | 7236 | if (!doms_cur) |
acc3f5d7 RR |
7237 | doms_cur = &fallback_doms; |
7238 | cpumask_andnot(doms_cur[0], cpu_map, cpu_isolated_map); | |
1d3504fc | 7239 | dattr_cur = NULL; |
acc3f5d7 | 7240 | err = build_sched_domains(doms_cur[0]); |
6382bc90 | 7241 | register_sched_domain_sysctl(); |
7378547f MM |
7242 | |
7243 | return err; | |
1a20ff27 DG |
7244 | } |
7245 | ||
96f874e2 RR |
7246 | static void arch_destroy_sched_domains(const struct cpumask *cpu_map, |
7247 | struct cpumask *tmpmask) | |
1da177e4 | 7248 | { |
7c16ec58 | 7249 | free_sched_groups(cpu_map, tmpmask); |
9c1cfda2 | 7250 | } |
1da177e4 | 7251 | |
1a20ff27 DG |
7252 | /* |
7253 | * Detach sched domains from a group of cpus specified in cpu_map | |
7254 | * These cpus will now be attached to the NULL domain | |
7255 | */ | |
96f874e2 | 7256 | static void detach_destroy_domains(const struct cpumask *cpu_map) |
1a20ff27 | 7257 | { |
96f874e2 RR |
7258 | /* Save because hotplug lock held. */ |
7259 | static DECLARE_BITMAP(tmpmask, CONFIG_NR_CPUS); | |
1a20ff27 DG |
7260 | int i; |
7261 | ||
abcd083a | 7262 | for_each_cpu(i, cpu_map) |
57d885fe | 7263 | cpu_attach_domain(NULL, &def_root_domain, i); |
1a20ff27 | 7264 | synchronize_sched(); |
96f874e2 | 7265 | arch_destroy_sched_domains(cpu_map, to_cpumask(tmpmask)); |
1a20ff27 DG |
7266 | } |
7267 | ||
1d3504fc HS |
7268 | /* handle null as "default" */ |
7269 | static int dattrs_equal(struct sched_domain_attr *cur, int idx_cur, | |
7270 | struct sched_domain_attr *new, int idx_new) | |
7271 | { | |
7272 | struct sched_domain_attr tmp; | |
7273 | ||
7274 | /* fast path */ | |
7275 | if (!new && !cur) | |
7276 | return 1; | |
7277 | ||
7278 | tmp = SD_ATTR_INIT; | |
7279 | return !memcmp(cur ? (cur + idx_cur) : &tmp, | |
7280 | new ? (new + idx_new) : &tmp, | |
7281 | sizeof(struct sched_domain_attr)); | |
7282 | } | |
7283 | ||
029190c5 PJ |
7284 | /* |
7285 | * Partition sched domains as specified by the 'ndoms_new' | |
41a2d6cf | 7286 | * cpumasks in the array doms_new[] of cpumasks. This compares |
029190c5 PJ |
7287 | * doms_new[] to the current sched domain partitioning, doms_cur[]. |
7288 | * It destroys each deleted domain and builds each new domain. | |
7289 | * | |
acc3f5d7 | 7290 | * 'doms_new' is an array of cpumask_var_t's of length 'ndoms_new'. |
41a2d6cf IM |
7291 | * The masks don't intersect (don't overlap.) We should setup one |
7292 | * sched domain for each mask. CPUs not in any of the cpumasks will | |
7293 | * not be load balanced. If the same cpumask appears both in the | |
029190c5 PJ |
7294 | * current 'doms_cur' domains and in the new 'doms_new', we can leave |
7295 | * it as it is. | |
7296 | * | |
acc3f5d7 RR |
7297 | * The passed in 'doms_new' should be allocated using |
7298 | * alloc_sched_domains. This routine takes ownership of it and will | |
7299 | * free_sched_domains it when done with it. If the caller failed the | |
7300 | * alloc call, then it can pass in doms_new == NULL && ndoms_new == 1, | |
7301 | * and partition_sched_domains() will fallback to the single partition | |
7302 | * 'fallback_doms', it also forces the domains to be rebuilt. | |
029190c5 | 7303 | * |
96f874e2 | 7304 | * If doms_new == NULL it will be replaced with cpu_online_mask. |
700018e0 LZ |
7305 | * ndoms_new == 0 is a special case for destroying existing domains, |
7306 | * and it will not create the default domain. | |
dfb512ec | 7307 | * |
029190c5 PJ |
7308 | * Call with hotplug lock held |
7309 | */ | |
acc3f5d7 | 7310 | void partition_sched_domains(int ndoms_new, cpumask_var_t doms_new[], |
1d3504fc | 7311 | struct sched_domain_attr *dattr_new) |
029190c5 | 7312 | { |
dfb512ec | 7313 | int i, j, n; |
d65bd5ec | 7314 | int new_topology; |
029190c5 | 7315 | |
712555ee | 7316 | mutex_lock(&sched_domains_mutex); |
a1835615 | 7317 | |
7378547f MM |
7318 | /* always unregister in case we don't destroy any domains */ |
7319 | unregister_sched_domain_sysctl(); | |
7320 | ||
d65bd5ec HC |
7321 | /* Let architecture update cpu core mappings. */ |
7322 | new_topology = arch_update_cpu_topology(); | |
7323 | ||
dfb512ec | 7324 | n = doms_new ? ndoms_new : 0; |
029190c5 PJ |
7325 | |
7326 | /* Destroy deleted domains */ | |
7327 | for (i = 0; i < ndoms_cur; i++) { | |
d65bd5ec | 7328 | for (j = 0; j < n && !new_topology; j++) { |
acc3f5d7 | 7329 | if (cpumask_equal(doms_cur[i], doms_new[j]) |
1d3504fc | 7330 | && dattrs_equal(dattr_cur, i, dattr_new, j)) |
029190c5 PJ |
7331 | goto match1; |
7332 | } | |
7333 | /* no match - a current sched domain not in new doms_new[] */ | |
acc3f5d7 | 7334 | detach_destroy_domains(doms_cur[i]); |
029190c5 PJ |
7335 | match1: |
7336 | ; | |
7337 | } | |
7338 | ||
e761b772 MK |
7339 | if (doms_new == NULL) { |
7340 | ndoms_cur = 0; | |
acc3f5d7 | 7341 | doms_new = &fallback_doms; |
6ad4c188 | 7342 | cpumask_andnot(doms_new[0], cpu_active_mask, cpu_isolated_map); |
faa2f98f | 7343 | WARN_ON_ONCE(dattr_new); |
e761b772 MK |
7344 | } |
7345 | ||
029190c5 PJ |
7346 | /* Build new domains */ |
7347 | for (i = 0; i < ndoms_new; i++) { | |
d65bd5ec | 7348 | for (j = 0; j < ndoms_cur && !new_topology; j++) { |
acc3f5d7 | 7349 | if (cpumask_equal(doms_new[i], doms_cur[j]) |
1d3504fc | 7350 | && dattrs_equal(dattr_new, i, dattr_cur, j)) |
029190c5 PJ |
7351 | goto match2; |
7352 | } | |
7353 | /* no match - add a new doms_new */ | |
acc3f5d7 | 7354 | __build_sched_domains(doms_new[i], |
1d3504fc | 7355 | dattr_new ? dattr_new + i : NULL); |
029190c5 PJ |
7356 | match2: |
7357 | ; | |
7358 | } | |
7359 | ||
7360 | /* Remember the new sched domains */ | |
acc3f5d7 RR |
7361 | if (doms_cur != &fallback_doms) |
7362 | free_sched_domains(doms_cur, ndoms_cur); | |
1d3504fc | 7363 | kfree(dattr_cur); /* kfree(NULL) is safe */ |
029190c5 | 7364 | doms_cur = doms_new; |
1d3504fc | 7365 | dattr_cur = dattr_new; |
029190c5 | 7366 | ndoms_cur = ndoms_new; |
7378547f MM |
7367 | |
7368 | register_sched_domain_sysctl(); | |
a1835615 | 7369 | |
712555ee | 7370 | mutex_unlock(&sched_domains_mutex); |
029190c5 PJ |
7371 | } |
7372 | ||
5c45bf27 | 7373 | #if defined(CONFIG_SCHED_MC) || defined(CONFIG_SCHED_SMT) |
c70f22d2 | 7374 | static void arch_reinit_sched_domains(void) |
5c45bf27 | 7375 | { |
95402b38 | 7376 | get_online_cpus(); |
dfb512ec MK |
7377 | |
7378 | /* Destroy domains first to force the rebuild */ | |
7379 | partition_sched_domains(0, NULL, NULL); | |
7380 | ||
e761b772 | 7381 | rebuild_sched_domains(); |
95402b38 | 7382 | put_online_cpus(); |
5c45bf27 SS |
7383 | } |
7384 | ||
7385 | static ssize_t sched_power_savings_store(const char *buf, size_t count, int smt) | |
7386 | { | |
afb8a9b7 | 7387 | unsigned int level = 0; |
5c45bf27 | 7388 | |
afb8a9b7 GS |
7389 | if (sscanf(buf, "%u", &level) != 1) |
7390 | return -EINVAL; | |
7391 | ||
7392 | /* | |
7393 | * level is always be positive so don't check for | |
7394 | * level < POWERSAVINGS_BALANCE_NONE which is 0 | |
7395 | * What happens on 0 or 1 byte write, | |
7396 | * need to check for count as well? | |
7397 | */ | |
7398 | ||
7399 | if (level >= MAX_POWERSAVINGS_BALANCE_LEVELS) | |
5c45bf27 SS |
7400 | return -EINVAL; |
7401 | ||
7402 | if (smt) | |
afb8a9b7 | 7403 | sched_smt_power_savings = level; |
5c45bf27 | 7404 | else |
afb8a9b7 | 7405 | sched_mc_power_savings = level; |
5c45bf27 | 7406 | |
c70f22d2 | 7407 | arch_reinit_sched_domains(); |
5c45bf27 | 7408 | |
c70f22d2 | 7409 | return count; |
5c45bf27 SS |
7410 | } |
7411 | ||
5c45bf27 | 7412 | #ifdef CONFIG_SCHED_MC |
f718cd4a | 7413 | static ssize_t sched_mc_power_savings_show(struct sysdev_class *class, |
c9be0a36 | 7414 | struct sysdev_class_attribute *attr, |
f718cd4a | 7415 | char *page) |
5c45bf27 SS |
7416 | { |
7417 | return sprintf(page, "%u\n", sched_mc_power_savings); | |
7418 | } | |
f718cd4a | 7419 | static ssize_t sched_mc_power_savings_store(struct sysdev_class *class, |
c9be0a36 | 7420 | struct sysdev_class_attribute *attr, |
48f24c4d | 7421 | const char *buf, size_t count) |
5c45bf27 SS |
7422 | { |
7423 | return sched_power_savings_store(buf, count, 0); | |
7424 | } | |
f718cd4a AK |
7425 | static SYSDEV_CLASS_ATTR(sched_mc_power_savings, 0644, |
7426 | sched_mc_power_savings_show, | |
7427 | sched_mc_power_savings_store); | |
5c45bf27 SS |
7428 | #endif |
7429 | ||
7430 | #ifdef CONFIG_SCHED_SMT | |
f718cd4a | 7431 | static ssize_t sched_smt_power_savings_show(struct sysdev_class *dev, |
c9be0a36 | 7432 | struct sysdev_class_attribute *attr, |
f718cd4a | 7433 | char *page) |
5c45bf27 SS |
7434 | { |
7435 | return sprintf(page, "%u\n", sched_smt_power_savings); | |
7436 | } | |
f718cd4a | 7437 | static ssize_t sched_smt_power_savings_store(struct sysdev_class *dev, |
c9be0a36 | 7438 | struct sysdev_class_attribute *attr, |
48f24c4d | 7439 | const char *buf, size_t count) |
5c45bf27 SS |
7440 | { |
7441 | return sched_power_savings_store(buf, count, 1); | |
7442 | } | |
f718cd4a AK |
7443 | static SYSDEV_CLASS_ATTR(sched_smt_power_savings, 0644, |
7444 | sched_smt_power_savings_show, | |
6707de00 AB |
7445 | sched_smt_power_savings_store); |
7446 | #endif | |
7447 | ||
39aac648 | 7448 | int __init sched_create_sysfs_power_savings_entries(struct sysdev_class *cls) |
6707de00 AB |
7449 | { |
7450 | int err = 0; | |
7451 | ||
7452 | #ifdef CONFIG_SCHED_SMT | |
7453 | if (smt_capable()) | |
7454 | err = sysfs_create_file(&cls->kset.kobj, | |
7455 | &attr_sched_smt_power_savings.attr); | |
7456 | #endif | |
7457 | #ifdef CONFIG_SCHED_MC | |
7458 | if (!err && mc_capable()) | |
7459 | err = sysfs_create_file(&cls->kset.kobj, | |
7460 | &attr_sched_mc_power_savings.attr); | |
7461 | #endif | |
7462 | return err; | |
7463 | } | |
6d6bc0ad | 7464 | #endif /* CONFIG_SCHED_MC || CONFIG_SCHED_SMT */ |
5c45bf27 | 7465 | |
e761b772 | 7466 | #ifndef CONFIG_CPUSETS |
1da177e4 | 7467 | /* |
e761b772 MK |
7468 | * Add online and remove offline CPUs from the scheduler domains. |
7469 | * When cpusets are enabled they take over this function. | |
1da177e4 LT |
7470 | */ |
7471 | static int update_sched_domains(struct notifier_block *nfb, | |
7472 | unsigned long action, void *hcpu) | |
e761b772 MK |
7473 | { |
7474 | switch (action) { | |
7475 | case CPU_ONLINE: | |
7476 | case CPU_ONLINE_FROZEN: | |
6ad4c188 PZ |
7477 | case CPU_DOWN_PREPARE: |
7478 | case CPU_DOWN_PREPARE_FROZEN: | |
7479 | case CPU_DOWN_FAILED: | |
7480 | case CPU_DOWN_FAILED_FROZEN: | |
dfb512ec | 7481 | partition_sched_domains(1, NULL, NULL); |
e761b772 MK |
7482 | return NOTIFY_OK; |
7483 | ||
7484 | default: | |
7485 | return NOTIFY_DONE; | |
7486 | } | |
7487 | } | |
7488 | #endif | |
7489 | ||
7490 | static int update_runtime(struct notifier_block *nfb, | |
7491 | unsigned long action, void *hcpu) | |
1da177e4 | 7492 | { |
7def2be1 PZ |
7493 | int cpu = (int)(long)hcpu; |
7494 | ||
1da177e4 | 7495 | switch (action) { |
1da177e4 | 7496 | case CPU_DOWN_PREPARE: |
8bb78442 | 7497 | case CPU_DOWN_PREPARE_FROZEN: |
7def2be1 | 7498 | disable_runtime(cpu_rq(cpu)); |
1da177e4 LT |
7499 | return NOTIFY_OK; |
7500 | ||
1da177e4 | 7501 | case CPU_DOWN_FAILED: |
8bb78442 | 7502 | case CPU_DOWN_FAILED_FROZEN: |
1da177e4 | 7503 | case CPU_ONLINE: |
8bb78442 | 7504 | case CPU_ONLINE_FROZEN: |
7def2be1 | 7505 | enable_runtime(cpu_rq(cpu)); |
e761b772 MK |
7506 | return NOTIFY_OK; |
7507 | ||
1da177e4 LT |
7508 | default: |
7509 | return NOTIFY_DONE; | |
7510 | } | |
1da177e4 | 7511 | } |
1da177e4 LT |
7512 | |
7513 | void __init sched_init_smp(void) | |
7514 | { | |
dcc30a35 RR |
7515 | cpumask_var_t non_isolated_cpus; |
7516 | ||
7517 | alloc_cpumask_var(&non_isolated_cpus, GFP_KERNEL); | |
cb5fd13f | 7518 | alloc_cpumask_var(&fallback_doms, GFP_KERNEL); |
5c1e1767 | 7519 | |
434d53b0 MT |
7520 | #if defined(CONFIG_NUMA) |
7521 | sched_group_nodes_bycpu = kzalloc(nr_cpu_ids * sizeof(void **), | |
7522 | GFP_KERNEL); | |
7523 | BUG_ON(sched_group_nodes_bycpu == NULL); | |
7524 | #endif | |
95402b38 | 7525 | get_online_cpus(); |
712555ee | 7526 | mutex_lock(&sched_domains_mutex); |
6ad4c188 | 7527 | arch_init_sched_domains(cpu_active_mask); |
dcc30a35 RR |
7528 | cpumask_andnot(non_isolated_cpus, cpu_possible_mask, cpu_isolated_map); |
7529 | if (cpumask_empty(non_isolated_cpus)) | |
7530 | cpumask_set_cpu(smp_processor_id(), non_isolated_cpus); | |
712555ee | 7531 | mutex_unlock(&sched_domains_mutex); |
95402b38 | 7532 | put_online_cpus(); |
e761b772 MK |
7533 | |
7534 | #ifndef CONFIG_CPUSETS | |
1da177e4 LT |
7535 | /* XXX: Theoretical race here - CPU may be hotplugged now */ |
7536 | hotcpu_notifier(update_sched_domains, 0); | |
e761b772 MK |
7537 | #endif |
7538 | ||
7539 | /* RT runtime code needs to handle some hotplug events */ | |
7540 | hotcpu_notifier(update_runtime, 0); | |
7541 | ||
b328ca18 | 7542 | init_hrtick(); |
5c1e1767 NP |
7543 | |
7544 | /* Move init over to a non-isolated CPU */ | |
dcc30a35 | 7545 | if (set_cpus_allowed_ptr(current, non_isolated_cpus) < 0) |
5c1e1767 | 7546 | BUG(); |
19978ca6 | 7547 | sched_init_granularity(); |
dcc30a35 | 7548 | free_cpumask_var(non_isolated_cpus); |
4212823f | 7549 | |
0e3900e6 | 7550 | init_sched_rt_class(); |
1da177e4 LT |
7551 | } |
7552 | #else | |
7553 | void __init sched_init_smp(void) | |
7554 | { | |
19978ca6 | 7555 | sched_init_granularity(); |
1da177e4 LT |
7556 | } |
7557 | #endif /* CONFIG_SMP */ | |
7558 | ||
cd1bb94b AB |
7559 | const_debug unsigned int sysctl_timer_migration = 1; |
7560 | ||
1da177e4 LT |
7561 | int in_sched_functions(unsigned long addr) |
7562 | { | |
1da177e4 LT |
7563 | return in_lock_functions(addr) || |
7564 | (addr >= (unsigned long)__sched_text_start | |
7565 | && addr < (unsigned long)__sched_text_end); | |
7566 | } | |
7567 | ||
a9957449 | 7568 | static void init_cfs_rq(struct cfs_rq *cfs_rq, struct rq *rq) |
dd41f596 IM |
7569 | { |
7570 | cfs_rq->tasks_timeline = RB_ROOT; | |
4a55bd5e | 7571 | INIT_LIST_HEAD(&cfs_rq->tasks); |
dd41f596 IM |
7572 | #ifdef CONFIG_FAIR_GROUP_SCHED |
7573 | cfs_rq->rq = rq; | |
7574 | #endif | |
67e9fb2a | 7575 | cfs_rq->min_vruntime = (u64)(-(1LL << 20)); |
dd41f596 IM |
7576 | } |
7577 | ||
fa85ae24 PZ |
7578 | static void init_rt_rq(struct rt_rq *rt_rq, struct rq *rq) |
7579 | { | |
7580 | struct rt_prio_array *array; | |
7581 | int i; | |
7582 | ||
7583 | array = &rt_rq->active; | |
7584 | for (i = 0; i < MAX_RT_PRIO; i++) { | |
7585 | INIT_LIST_HEAD(array->queue + i); | |
7586 | __clear_bit(i, array->bitmap); | |
7587 | } | |
7588 | /* delimiter for bitsearch: */ | |
7589 | __set_bit(MAX_RT_PRIO, array->bitmap); | |
7590 | ||
052f1dc7 | 7591 | #if defined CONFIG_SMP || defined CONFIG_RT_GROUP_SCHED |
e864c499 | 7592 | rt_rq->highest_prio.curr = MAX_RT_PRIO; |
398a153b | 7593 | #ifdef CONFIG_SMP |
e864c499 | 7594 | rt_rq->highest_prio.next = MAX_RT_PRIO; |
48d5e258 | 7595 | #endif |
48d5e258 | 7596 | #endif |
fa85ae24 PZ |
7597 | #ifdef CONFIG_SMP |
7598 | rt_rq->rt_nr_migratory = 0; | |
fa85ae24 | 7599 | rt_rq->overloaded = 0; |
05fa785c | 7600 | plist_head_init_raw(&rt_rq->pushable_tasks, &rq->lock); |
fa85ae24 PZ |
7601 | #endif |
7602 | ||
7603 | rt_rq->rt_time = 0; | |
7604 | rt_rq->rt_throttled = 0; | |
ac086bc2 | 7605 | rt_rq->rt_runtime = 0; |
0986b11b | 7606 | raw_spin_lock_init(&rt_rq->rt_runtime_lock); |
6f505b16 | 7607 | |
052f1dc7 | 7608 | #ifdef CONFIG_RT_GROUP_SCHED |
23b0fdfc | 7609 | rt_rq->rt_nr_boosted = 0; |
6f505b16 PZ |
7610 | rt_rq->rq = rq; |
7611 | #endif | |
fa85ae24 PZ |
7612 | } |
7613 | ||
6f505b16 | 7614 | #ifdef CONFIG_FAIR_GROUP_SCHED |
ec7dc8ac DG |
7615 | static void init_tg_cfs_entry(struct task_group *tg, struct cfs_rq *cfs_rq, |
7616 | struct sched_entity *se, int cpu, int add, | |
7617 | struct sched_entity *parent) | |
6f505b16 | 7618 | { |
ec7dc8ac | 7619 | struct rq *rq = cpu_rq(cpu); |
6f505b16 PZ |
7620 | tg->cfs_rq[cpu] = cfs_rq; |
7621 | init_cfs_rq(cfs_rq, rq); | |
7622 | cfs_rq->tg = tg; | |
7623 | if (add) | |
7624 | list_add(&cfs_rq->leaf_cfs_rq_list, &rq->leaf_cfs_rq_list); | |
7625 | ||
7626 | tg->se[cpu] = se; | |
354d60c2 DG |
7627 | /* se could be NULL for init_task_group */ |
7628 | if (!se) | |
7629 | return; | |
7630 | ||
ec7dc8ac DG |
7631 | if (!parent) |
7632 | se->cfs_rq = &rq->cfs; | |
7633 | else | |
7634 | se->cfs_rq = parent->my_q; | |
7635 | ||
6f505b16 PZ |
7636 | se->my_q = cfs_rq; |
7637 | se->load.weight = tg->shares; | |
e05510d0 | 7638 | se->load.inv_weight = 0; |
ec7dc8ac | 7639 | se->parent = parent; |
6f505b16 | 7640 | } |
052f1dc7 | 7641 | #endif |
6f505b16 | 7642 | |
052f1dc7 | 7643 | #ifdef CONFIG_RT_GROUP_SCHED |
ec7dc8ac DG |
7644 | static void init_tg_rt_entry(struct task_group *tg, struct rt_rq *rt_rq, |
7645 | struct sched_rt_entity *rt_se, int cpu, int add, | |
7646 | struct sched_rt_entity *parent) | |
6f505b16 | 7647 | { |
ec7dc8ac DG |
7648 | struct rq *rq = cpu_rq(cpu); |
7649 | ||
6f505b16 PZ |
7650 | tg->rt_rq[cpu] = rt_rq; |
7651 | init_rt_rq(rt_rq, rq); | |
7652 | rt_rq->tg = tg; | |
ac086bc2 | 7653 | rt_rq->rt_runtime = tg->rt_bandwidth.rt_runtime; |
6f505b16 PZ |
7654 | if (add) |
7655 | list_add(&rt_rq->leaf_rt_rq_list, &rq->leaf_rt_rq_list); | |
7656 | ||
7657 | tg->rt_se[cpu] = rt_se; | |
354d60c2 DG |
7658 | if (!rt_se) |
7659 | return; | |
7660 | ||
ec7dc8ac DG |
7661 | if (!parent) |
7662 | rt_se->rt_rq = &rq->rt; | |
7663 | else | |
7664 | rt_se->rt_rq = parent->my_q; | |
7665 | ||
6f505b16 | 7666 | rt_se->my_q = rt_rq; |
ec7dc8ac | 7667 | rt_se->parent = parent; |
6f505b16 PZ |
7668 | INIT_LIST_HEAD(&rt_se->run_list); |
7669 | } | |
7670 | #endif | |
7671 | ||
1da177e4 LT |
7672 | void __init sched_init(void) |
7673 | { | |
dd41f596 | 7674 | int i, j; |
434d53b0 MT |
7675 | unsigned long alloc_size = 0, ptr; |
7676 | ||
7677 | #ifdef CONFIG_FAIR_GROUP_SCHED | |
7678 | alloc_size += 2 * nr_cpu_ids * sizeof(void **); | |
7679 | #endif | |
7680 | #ifdef CONFIG_RT_GROUP_SCHED | |
7681 | alloc_size += 2 * nr_cpu_ids * sizeof(void **); | |
eff766a6 | 7682 | #endif |
df7c8e84 | 7683 | #ifdef CONFIG_CPUMASK_OFFSTACK |
8c083f08 | 7684 | alloc_size += num_possible_cpus() * cpumask_size(); |
434d53b0 | 7685 | #endif |
434d53b0 | 7686 | if (alloc_size) { |
36b7b6d4 | 7687 | ptr = (unsigned long)kzalloc(alloc_size, GFP_NOWAIT); |
434d53b0 MT |
7688 | |
7689 | #ifdef CONFIG_FAIR_GROUP_SCHED | |
7690 | init_task_group.se = (struct sched_entity **)ptr; | |
7691 | ptr += nr_cpu_ids * sizeof(void **); | |
7692 | ||
7693 | init_task_group.cfs_rq = (struct cfs_rq **)ptr; | |
7694 | ptr += nr_cpu_ids * sizeof(void **); | |
eff766a6 | 7695 | |
6d6bc0ad | 7696 | #endif /* CONFIG_FAIR_GROUP_SCHED */ |
434d53b0 MT |
7697 | #ifdef CONFIG_RT_GROUP_SCHED |
7698 | init_task_group.rt_se = (struct sched_rt_entity **)ptr; | |
7699 | ptr += nr_cpu_ids * sizeof(void **); | |
7700 | ||
7701 | init_task_group.rt_rq = (struct rt_rq **)ptr; | |
eff766a6 PZ |
7702 | ptr += nr_cpu_ids * sizeof(void **); |
7703 | ||
6d6bc0ad | 7704 | #endif /* CONFIG_RT_GROUP_SCHED */ |
df7c8e84 RR |
7705 | #ifdef CONFIG_CPUMASK_OFFSTACK |
7706 | for_each_possible_cpu(i) { | |
7707 | per_cpu(load_balance_tmpmask, i) = (void *)ptr; | |
7708 | ptr += cpumask_size(); | |
7709 | } | |
7710 | #endif /* CONFIG_CPUMASK_OFFSTACK */ | |
434d53b0 | 7711 | } |
dd41f596 | 7712 | |
57d885fe GH |
7713 | #ifdef CONFIG_SMP |
7714 | init_defrootdomain(); | |
7715 | #endif | |
7716 | ||
d0b27fa7 PZ |
7717 | init_rt_bandwidth(&def_rt_bandwidth, |
7718 | global_rt_period(), global_rt_runtime()); | |
7719 | ||
7720 | #ifdef CONFIG_RT_GROUP_SCHED | |
7721 | init_rt_bandwidth(&init_task_group.rt_bandwidth, | |
7722 | global_rt_period(), global_rt_runtime()); | |
6d6bc0ad | 7723 | #endif /* CONFIG_RT_GROUP_SCHED */ |
d0b27fa7 | 7724 | |
7c941438 | 7725 | #ifdef CONFIG_CGROUP_SCHED |
6f505b16 | 7726 | list_add(&init_task_group.list, &task_groups); |
f473aa5e PZ |
7727 | INIT_LIST_HEAD(&init_task_group.children); |
7728 | ||
7c941438 | 7729 | #endif /* CONFIG_CGROUP_SCHED */ |
6f505b16 | 7730 | |
4a6cc4bd JK |
7731 | #if defined CONFIG_FAIR_GROUP_SCHED && defined CONFIG_SMP |
7732 | update_shares_data = __alloc_percpu(nr_cpu_ids * sizeof(unsigned long), | |
7733 | __alignof__(unsigned long)); | |
7734 | #endif | |
0a945022 | 7735 | for_each_possible_cpu(i) { |
70b97a7f | 7736 | struct rq *rq; |
1da177e4 LT |
7737 | |
7738 | rq = cpu_rq(i); | |
05fa785c | 7739 | raw_spin_lock_init(&rq->lock); |
7897986b | 7740 | rq->nr_running = 0; |
dce48a84 TG |
7741 | rq->calc_load_active = 0; |
7742 | rq->calc_load_update = jiffies + LOAD_FREQ; | |
dd41f596 | 7743 | init_cfs_rq(&rq->cfs, rq); |
6f505b16 | 7744 | init_rt_rq(&rq->rt, rq); |
dd41f596 | 7745 | #ifdef CONFIG_FAIR_GROUP_SCHED |
4cf86d77 | 7746 | init_task_group.shares = init_task_group_load; |
6f505b16 | 7747 | INIT_LIST_HEAD(&rq->leaf_cfs_rq_list); |
354d60c2 DG |
7748 | #ifdef CONFIG_CGROUP_SCHED |
7749 | /* | |
7750 | * How much cpu bandwidth does init_task_group get? | |
7751 | * | |
7752 | * In case of task-groups formed thr' the cgroup filesystem, it | |
7753 | * gets 100% of the cpu resources in the system. This overall | |
7754 | * system cpu resource is divided among the tasks of | |
7755 | * init_task_group and its child task-groups in a fair manner, | |
7756 | * based on each entity's (task or task-group's) weight | |
7757 | * (se->load.weight). | |
7758 | * | |
7759 | * In other words, if init_task_group has 10 tasks of weight | |
7760 | * 1024) and two child groups A0 and A1 (of weight 1024 each), | |
7761 | * then A0's share of the cpu resource is: | |
7762 | * | |
0d905bca | 7763 | * A0's bandwidth = 1024 / (10*1024 + 1024 + 1024) = 8.33% |
354d60c2 DG |
7764 | * |
7765 | * We achieve this by letting init_task_group's tasks sit | |
7766 | * directly in rq->cfs (i.e init_task_group->se[] = NULL). | |
7767 | */ | |
ec7dc8ac | 7768 | init_tg_cfs_entry(&init_task_group, &rq->cfs, NULL, i, 1, NULL); |
052f1dc7 | 7769 | #endif |
354d60c2 DG |
7770 | #endif /* CONFIG_FAIR_GROUP_SCHED */ |
7771 | ||
7772 | rq->rt.rt_runtime = def_rt_bandwidth.rt_runtime; | |
052f1dc7 | 7773 | #ifdef CONFIG_RT_GROUP_SCHED |
6f505b16 | 7774 | INIT_LIST_HEAD(&rq->leaf_rt_rq_list); |
354d60c2 | 7775 | #ifdef CONFIG_CGROUP_SCHED |
ec7dc8ac | 7776 | init_tg_rt_entry(&init_task_group, &rq->rt, NULL, i, 1, NULL); |
354d60c2 | 7777 | #endif |
dd41f596 | 7778 | #endif |
1da177e4 | 7779 | |
dd41f596 IM |
7780 | for (j = 0; j < CPU_LOAD_IDX_MAX; j++) |
7781 | rq->cpu_load[j] = 0; | |
1da177e4 | 7782 | #ifdef CONFIG_SMP |
41c7ce9a | 7783 | rq->sd = NULL; |
57d885fe | 7784 | rq->rd = NULL; |
3f029d3c | 7785 | rq->post_schedule = 0; |
1da177e4 | 7786 | rq->active_balance = 0; |
dd41f596 | 7787 | rq->next_balance = jiffies; |
1da177e4 | 7788 | rq->push_cpu = 0; |
0a2966b4 | 7789 | rq->cpu = i; |
1f11eb6a | 7790 | rq->online = 0; |
1da177e4 | 7791 | rq->migration_thread = NULL; |
eae0c9df MG |
7792 | rq->idle_stamp = 0; |
7793 | rq->avg_idle = 2*sysctl_sched_migration_cost; | |
1da177e4 | 7794 | INIT_LIST_HEAD(&rq->migration_queue); |
dc938520 | 7795 | rq_attach_root(rq, &def_root_domain); |
1da177e4 | 7796 | #endif |
8f4d37ec | 7797 | init_rq_hrtick(rq); |
1da177e4 | 7798 | atomic_set(&rq->nr_iowait, 0); |
1da177e4 LT |
7799 | } |
7800 | ||
2dd73a4f | 7801 | set_load_weight(&init_task); |
b50f60ce | 7802 | |
e107be36 AK |
7803 | #ifdef CONFIG_PREEMPT_NOTIFIERS |
7804 | INIT_HLIST_HEAD(&init_task.preempt_notifiers); | |
7805 | #endif | |
7806 | ||
c9819f45 | 7807 | #ifdef CONFIG_SMP |
962cf36c | 7808 | open_softirq(SCHED_SOFTIRQ, run_rebalance_domains); |
c9819f45 CL |
7809 | #endif |
7810 | ||
b50f60ce | 7811 | #ifdef CONFIG_RT_MUTEXES |
1d615482 | 7812 | plist_head_init_raw(&init_task.pi_waiters, &init_task.pi_lock); |
b50f60ce HC |
7813 | #endif |
7814 | ||
1da177e4 LT |
7815 | /* |
7816 | * The boot idle thread does lazy MMU switching as well: | |
7817 | */ | |
7818 | atomic_inc(&init_mm.mm_count); | |
7819 | enter_lazy_tlb(&init_mm, current); | |
7820 | ||
7821 | /* | |
7822 | * Make us the idle thread. Technically, schedule() should not be | |
7823 | * called from this thread, however somewhere below it might be, | |
7824 | * but because we are the idle thread, we just pick up running again | |
7825 | * when this runqueue becomes "idle". | |
7826 | */ | |
7827 | init_idle(current, smp_processor_id()); | |
dce48a84 TG |
7828 | |
7829 | calc_load_update = jiffies + LOAD_FREQ; | |
7830 | ||
dd41f596 IM |
7831 | /* |
7832 | * During early bootup we pretend to be a normal task: | |
7833 | */ | |
7834 | current->sched_class = &fair_sched_class; | |
6892b75e | 7835 | |
6a7b3dc3 | 7836 | /* Allocate the nohz_cpu_mask if CONFIG_CPUMASK_OFFSTACK */ |
49557e62 | 7837 | zalloc_cpumask_var(&nohz_cpu_mask, GFP_NOWAIT); |
bf4d83f6 | 7838 | #ifdef CONFIG_SMP |
7d1e6a9b | 7839 | #ifdef CONFIG_NO_HZ |
49557e62 | 7840 | zalloc_cpumask_var(&nohz.cpu_mask, GFP_NOWAIT); |
4bdddf8f | 7841 | alloc_cpumask_var(&nohz.ilb_grp_nohz_mask, GFP_NOWAIT); |
7d1e6a9b | 7842 | #endif |
bdddd296 RR |
7843 | /* May be allocated at isolcpus cmdline parse time */ |
7844 | if (cpu_isolated_map == NULL) | |
7845 | zalloc_cpumask_var(&cpu_isolated_map, GFP_NOWAIT); | |
bf4d83f6 | 7846 | #endif /* SMP */ |
6a7b3dc3 | 7847 | |
cdd6c482 | 7848 | perf_event_init(); |
0d905bca | 7849 | |
6892b75e | 7850 | scheduler_running = 1; |
1da177e4 LT |
7851 | } |
7852 | ||
7853 | #ifdef CONFIG_DEBUG_SPINLOCK_SLEEP | |
e4aafea2 FW |
7854 | static inline int preempt_count_equals(int preempt_offset) |
7855 | { | |
234da7bc | 7856 | int nested = (preempt_count() & ~PREEMPT_ACTIVE) + rcu_preempt_depth(); |
e4aafea2 FW |
7857 | |
7858 | return (nested == PREEMPT_INATOMIC_BASE + preempt_offset); | |
7859 | } | |
7860 | ||
d894837f | 7861 | void __might_sleep(const char *file, int line, int preempt_offset) |
1da177e4 | 7862 | { |
48f24c4d | 7863 | #ifdef in_atomic |
1da177e4 LT |
7864 | static unsigned long prev_jiffy; /* ratelimiting */ |
7865 | ||
e4aafea2 FW |
7866 | if ((preempt_count_equals(preempt_offset) && !irqs_disabled()) || |
7867 | system_state != SYSTEM_RUNNING || oops_in_progress) | |
aef745fc IM |
7868 | return; |
7869 | if (time_before(jiffies, prev_jiffy + HZ) && prev_jiffy) | |
7870 | return; | |
7871 | prev_jiffy = jiffies; | |
7872 | ||
3df0fc5b PZ |
7873 | printk(KERN_ERR |
7874 | "BUG: sleeping function called from invalid context at %s:%d\n", | |
7875 | file, line); | |
7876 | printk(KERN_ERR | |
7877 | "in_atomic(): %d, irqs_disabled(): %d, pid: %d, name: %s\n", | |
7878 | in_atomic(), irqs_disabled(), | |
7879 | current->pid, current->comm); | |
aef745fc IM |
7880 | |
7881 | debug_show_held_locks(current); | |
7882 | if (irqs_disabled()) | |
7883 | print_irqtrace_events(current); | |
7884 | dump_stack(); | |
1da177e4 LT |
7885 | #endif |
7886 | } | |
7887 | EXPORT_SYMBOL(__might_sleep); | |
7888 | #endif | |
7889 | ||
7890 | #ifdef CONFIG_MAGIC_SYSRQ | |
3a5e4dc1 AK |
7891 | static void normalize_task(struct rq *rq, struct task_struct *p) |
7892 | { | |
7893 | int on_rq; | |
3e51f33f | 7894 | |
3a5e4dc1 AK |
7895 | update_rq_clock(rq); |
7896 | on_rq = p->se.on_rq; | |
7897 | if (on_rq) | |
7898 | deactivate_task(rq, p, 0); | |
7899 | __setscheduler(rq, p, SCHED_NORMAL, 0); | |
7900 | if (on_rq) { | |
7901 | activate_task(rq, p, 0); | |
7902 | resched_task(rq->curr); | |
7903 | } | |
7904 | } | |
7905 | ||
1da177e4 LT |
7906 | void normalize_rt_tasks(void) |
7907 | { | |
a0f98a1c | 7908 | struct task_struct *g, *p; |
1da177e4 | 7909 | unsigned long flags; |
70b97a7f | 7910 | struct rq *rq; |
1da177e4 | 7911 | |
4cf5d77a | 7912 | read_lock_irqsave(&tasklist_lock, flags); |
a0f98a1c | 7913 | do_each_thread(g, p) { |
178be793 IM |
7914 | /* |
7915 | * Only normalize user tasks: | |
7916 | */ | |
7917 | if (!p->mm) | |
7918 | continue; | |
7919 | ||
6cfb0d5d | 7920 | p->se.exec_start = 0; |
6cfb0d5d | 7921 | #ifdef CONFIG_SCHEDSTATS |
dd41f596 | 7922 | p->se.wait_start = 0; |
dd41f596 | 7923 | p->se.sleep_start = 0; |
dd41f596 | 7924 | p->se.block_start = 0; |
6cfb0d5d | 7925 | #endif |
dd41f596 IM |
7926 | |
7927 | if (!rt_task(p)) { | |
7928 | /* | |
7929 | * Renice negative nice level userspace | |
7930 | * tasks back to 0: | |
7931 | */ | |
7932 | if (TASK_NICE(p) < 0 && p->mm) | |
7933 | set_user_nice(p, 0); | |
1da177e4 | 7934 | continue; |
dd41f596 | 7935 | } |
1da177e4 | 7936 | |
1d615482 | 7937 | raw_spin_lock(&p->pi_lock); |
b29739f9 | 7938 | rq = __task_rq_lock(p); |
1da177e4 | 7939 | |
178be793 | 7940 | normalize_task(rq, p); |
3a5e4dc1 | 7941 | |
b29739f9 | 7942 | __task_rq_unlock(rq); |
1d615482 | 7943 | raw_spin_unlock(&p->pi_lock); |
a0f98a1c IM |
7944 | } while_each_thread(g, p); |
7945 | ||
4cf5d77a | 7946 | read_unlock_irqrestore(&tasklist_lock, flags); |
1da177e4 LT |
7947 | } |
7948 | ||
7949 | #endif /* CONFIG_MAGIC_SYSRQ */ | |
1df5c10a LT |
7950 | |
7951 | #ifdef CONFIG_IA64 | |
7952 | /* | |
7953 | * These functions are only useful for the IA64 MCA handling. | |
7954 | * | |
7955 | * They can only be called when the whole system has been | |
7956 | * stopped - every CPU needs to be quiescent, and no scheduling | |
7957 | * activity can take place. Using them for anything else would | |
7958 | * be a serious bug, and as a result, they aren't even visible | |
7959 | * under any other configuration. | |
7960 | */ | |
7961 | ||
7962 | /** | |
7963 | * curr_task - return the current task for a given cpu. | |
7964 | * @cpu: the processor in question. | |
7965 | * | |
7966 | * ONLY VALID WHEN THE WHOLE SYSTEM IS STOPPED! | |
7967 | */ | |
36c8b586 | 7968 | struct task_struct *curr_task(int cpu) |
1df5c10a LT |
7969 | { |
7970 | return cpu_curr(cpu); | |
7971 | } | |
7972 | ||
7973 | /** | |
7974 | * set_curr_task - set the current task for a given cpu. | |
7975 | * @cpu: the processor in question. | |
7976 | * @p: the task pointer to set. | |
7977 | * | |
7978 | * Description: This function must only be used when non-maskable interrupts | |
41a2d6cf IM |
7979 | * are serviced on a separate stack. It allows the architecture to switch the |
7980 | * notion of the current task on a cpu in a non-blocking manner. This function | |
1df5c10a LT |
7981 | * must be called with all CPU's synchronized, and interrupts disabled, the |
7982 | * and caller must save the original value of the current task (see | |
7983 | * curr_task() above) and restore that value before reenabling interrupts and | |
7984 | * re-starting the system. | |
7985 | * | |
7986 | * ONLY VALID WHEN THE WHOLE SYSTEM IS STOPPED! | |
7987 | */ | |
36c8b586 | 7988 | void set_curr_task(int cpu, struct task_struct *p) |
1df5c10a LT |
7989 | { |
7990 | cpu_curr(cpu) = p; | |
7991 | } | |
7992 | ||
7993 | #endif | |
29f59db3 | 7994 | |
bccbe08a PZ |
7995 | #ifdef CONFIG_FAIR_GROUP_SCHED |
7996 | static void free_fair_sched_group(struct task_group *tg) | |
6f505b16 PZ |
7997 | { |
7998 | int i; | |
7999 | ||
8000 | for_each_possible_cpu(i) { | |
8001 | if (tg->cfs_rq) | |
8002 | kfree(tg->cfs_rq[i]); | |
8003 | if (tg->se) | |
8004 | kfree(tg->se[i]); | |
6f505b16 PZ |
8005 | } |
8006 | ||
8007 | kfree(tg->cfs_rq); | |
8008 | kfree(tg->se); | |
6f505b16 PZ |
8009 | } |
8010 | ||
ec7dc8ac DG |
8011 | static |
8012 | int alloc_fair_sched_group(struct task_group *tg, struct task_group *parent) | |
29f59db3 | 8013 | { |
29f59db3 | 8014 | struct cfs_rq *cfs_rq; |
eab17229 | 8015 | struct sched_entity *se; |
9b5b7751 | 8016 | struct rq *rq; |
29f59db3 SV |
8017 | int i; |
8018 | ||
434d53b0 | 8019 | tg->cfs_rq = kzalloc(sizeof(cfs_rq) * nr_cpu_ids, GFP_KERNEL); |
29f59db3 SV |
8020 | if (!tg->cfs_rq) |
8021 | goto err; | |
434d53b0 | 8022 | tg->se = kzalloc(sizeof(se) * nr_cpu_ids, GFP_KERNEL); |
29f59db3 SV |
8023 | if (!tg->se) |
8024 | goto err; | |
052f1dc7 PZ |
8025 | |
8026 | tg->shares = NICE_0_LOAD; | |
29f59db3 SV |
8027 | |
8028 | for_each_possible_cpu(i) { | |
9b5b7751 | 8029 | rq = cpu_rq(i); |
29f59db3 | 8030 | |
eab17229 LZ |
8031 | cfs_rq = kzalloc_node(sizeof(struct cfs_rq), |
8032 | GFP_KERNEL, cpu_to_node(i)); | |
29f59db3 SV |
8033 | if (!cfs_rq) |
8034 | goto err; | |
8035 | ||
eab17229 LZ |
8036 | se = kzalloc_node(sizeof(struct sched_entity), |
8037 | GFP_KERNEL, cpu_to_node(i)); | |
29f59db3 | 8038 | if (!se) |
dfc12eb2 | 8039 | goto err_free_rq; |
29f59db3 | 8040 | |
eab17229 | 8041 | init_tg_cfs_entry(tg, cfs_rq, se, i, 0, parent->se[i]); |
bccbe08a PZ |
8042 | } |
8043 | ||
8044 | return 1; | |
8045 | ||
dfc12eb2 PC |
8046 | err_free_rq: |
8047 | kfree(cfs_rq); | |
bccbe08a PZ |
8048 | err: |
8049 | return 0; | |
8050 | } | |
8051 | ||
8052 | static inline void register_fair_sched_group(struct task_group *tg, int cpu) | |
8053 | { | |
8054 | list_add_rcu(&tg->cfs_rq[cpu]->leaf_cfs_rq_list, | |
8055 | &cpu_rq(cpu)->leaf_cfs_rq_list); | |
8056 | } | |
8057 | ||
8058 | static inline void unregister_fair_sched_group(struct task_group *tg, int cpu) | |
8059 | { | |
8060 | list_del_rcu(&tg->cfs_rq[cpu]->leaf_cfs_rq_list); | |
8061 | } | |
6d6bc0ad | 8062 | #else /* !CONFG_FAIR_GROUP_SCHED */ |
bccbe08a PZ |
8063 | static inline void free_fair_sched_group(struct task_group *tg) |
8064 | { | |
8065 | } | |
8066 | ||
ec7dc8ac DG |
8067 | static inline |
8068 | int alloc_fair_sched_group(struct task_group *tg, struct task_group *parent) | |
bccbe08a PZ |
8069 | { |
8070 | return 1; | |
8071 | } | |
8072 | ||
8073 | static inline void register_fair_sched_group(struct task_group *tg, int cpu) | |
8074 | { | |
8075 | } | |
8076 | ||
8077 | static inline void unregister_fair_sched_group(struct task_group *tg, int cpu) | |
8078 | { | |
8079 | } | |
6d6bc0ad | 8080 | #endif /* CONFIG_FAIR_GROUP_SCHED */ |
052f1dc7 PZ |
8081 | |
8082 | #ifdef CONFIG_RT_GROUP_SCHED | |
bccbe08a PZ |
8083 | static void free_rt_sched_group(struct task_group *tg) |
8084 | { | |
8085 | int i; | |
8086 | ||
d0b27fa7 PZ |
8087 | destroy_rt_bandwidth(&tg->rt_bandwidth); |
8088 | ||
bccbe08a PZ |
8089 | for_each_possible_cpu(i) { |
8090 | if (tg->rt_rq) | |
8091 | kfree(tg->rt_rq[i]); | |
8092 | if (tg->rt_se) | |
8093 | kfree(tg->rt_se[i]); | |
8094 | } | |
8095 | ||
8096 | kfree(tg->rt_rq); | |
8097 | kfree(tg->rt_se); | |
8098 | } | |
8099 | ||
ec7dc8ac DG |
8100 | static |
8101 | int alloc_rt_sched_group(struct task_group *tg, struct task_group *parent) | |
bccbe08a PZ |
8102 | { |
8103 | struct rt_rq *rt_rq; | |
eab17229 | 8104 | struct sched_rt_entity *rt_se; |
bccbe08a PZ |
8105 | struct rq *rq; |
8106 | int i; | |
8107 | ||
434d53b0 | 8108 | tg->rt_rq = kzalloc(sizeof(rt_rq) * nr_cpu_ids, GFP_KERNEL); |
bccbe08a PZ |
8109 | if (!tg->rt_rq) |
8110 | goto err; | |
434d53b0 | 8111 | tg->rt_se = kzalloc(sizeof(rt_se) * nr_cpu_ids, GFP_KERNEL); |
bccbe08a PZ |
8112 | if (!tg->rt_se) |
8113 | goto err; | |
8114 | ||
d0b27fa7 PZ |
8115 | init_rt_bandwidth(&tg->rt_bandwidth, |
8116 | ktime_to_ns(def_rt_bandwidth.rt_period), 0); | |
bccbe08a PZ |
8117 | |
8118 | for_each_possible_cpu(i) { | |
8119 | rq = cpu_rq(i); | |
8120 | ||
eab17229 LZ |
8121 | rt_rq = kzalloc_node(sizeof(struct rt_rq), |
8122 | GFP_KERNEL, cpu_to_node(i)); | |
6f505b16 PZ |
8123 | if (!rt_rq) |
8124 | goto err; | |
29f59db3 | 8125 | |
eab17229 LZ |
8126 | rt_se = kzalloc_node(sizeof(struct sched_rt_entity), |
8127 | GFP_KERNEL, cpu_to_node(i)); | |
6f505b16 | 8128 | if (!rt_se) |
dfc12eb2 | 8129 | goto err_free_rq; |
29f59db3 | 8130 | |
eab17229 | 8131 | init_tg_rt_entry(tg, rt_rq, rt_se, i, 0, parent->rt_se[i]); |
29f59db3 SV |
8132 | } |
8133 | ||
bccbe08a PZ |
8134 | return 1; |
8135 | ||
dfc12eb2 PC |
8136 | err_free_rq: |
8137 | kfree(rt_rq); | |
bccbe08a PZ |
8138 | err: |
8139 | return 0; | |
8140 | } | |
8141 | ||
8142 | static inline void register_rt_sched_group(struct task_group *tg, int cpu) | |
8143 | { | |
8144 | list_add_rcu(&tg->rt_rq[cpu]->leaf_rt_rq_list, | |
8145 | &cpu_rq(cpu)->leaf_rt_rq_list); | |
8146 | } | |
8147 | ||
8148 | static inline void unregister_rt_sched_group(struct task_group *tg, int cpu) | |
8149 | { | |
8150 | list_del_rcu(&tg->rt_rq[cpu]->leaf_rt_rq_list); | |
8151 | } | |
6d6bc0ad | 8152 | #else /* !CONFIG_RT_GROUP_SCHED */ |
bccbe08a PZ |
8153 | static inline void free_rt_sched_group(struct task_group *tg) |
8154 | { | |
8155 | } | |
8156 | ||
ec7dc8ac DG |
8157 | static inline |
8158 | int alloc_rt_sched_group(struct task_group *tg, struct task_group *parent) | |
bccbe08a PZ |
8159 | { |
8160 | return 1; | |
8161 | } | |
8162 | ||
8163 | static inline void register_rt_sched_group(struct task_group *tg, int cpu) | |
8164 | { | |
8165 | } | |
8166 | ||
8167 | static inline void unregister_rt_sched_group(struct task_group *tg, int cpu) | |
8168 | { | |
8169 | } | |
6d6bc0ad | 8170 | #endif /* CONFIG_RT_GROUP_SCHED */ |
bccbe08a | 8171 | |
7c941438 | 8172 | #ifdef CONFIG_CGROUP_SCHED |
bccbe08a PZ |
8173 | static void free_sched_group(struct task_group *tg) |
8174 | { | |
8175 | free_fair_sched_group(tg); | |
8176 | free_rt_sched_group(tg); | |
8177 | kfree(tg); | |
8178 | } | |
8179 | ||
8180 | /* allocate runqueue etc for a new task group */ | |
ec7dc8ac | 8181 | struct task_group *sched_create_group(struct task_group *parent) |
bccbe08a PZ |
8182 | { |
8183 | struct task_group *tg; | |
8184 | unsigned long flags; | |
8185 | int i; | |
8186 | ||
8187 | tg = kzalloc(sizeof(*tg), GFP_KERNEL); | |
8188 | if (!tg) | |
8189 | return ERR_PTR(-ENOMEM); | |
8190 | ||
ec7dc8ac | 8191 | if (!alloc_fair_sched_group(tg, parent)) |
bccbe08a PZ |
8192 | goto err; |
8193 | ||
ec7dc8ac | 8194 | if (!alloc_rt_sched_group(tg, parent)) |
bccbe08a PZ |
8195 | goto err; |
8196 | ||
8ed36996 | 8197 | spin_lock_irqsave(&task_group_lock, flags); |
9b5b7751 | 8198 | for_each_possible_cpu(i) { |
bccbe08a PZ |
8199 | register_fair_sched_group(tg, i); |
8200 | register_rt_sched_group(tg, i); | |
9b5b7751 | 8201 | } |
6f505b16 | 8202 | list_add_rcu(&tg->list, &task_groups); |
f473aa5e PZ |
8203 | |
8204 | WARN_ON(!parent); /* root should already exist */ | |
8205 | ||
8206 | tg->parent = parent; | |
f473aa5e | 8207 | INIT_LIST_HEAD(&tg->children); |
09f2724a | 8208 | list_add_rcu(&tg->siblings, &parent->children); |
8ed36996 | 8209 | spin_unlock_irqrestore(&task_group_lock, flags); |
29f59db3 | 8210 | |
9b5b7751 | 8211 | return tg; |
29f59db3 SV |
8212 | |
8213 | err: | |
6f505b16 | 8214 | free_sched_group(tg); |
29f59db3 SV |
8215 | return ERR_PTR(-ENOMEM); |
8216 | } | |
8217 | ||
9b5b7751 | 8218 | /* rcu callback to free various structures associated with a task group */ |
6f505b16 | 8219 | static void free_sched_group_rcu(struct rcu_head *rhp) |
29f59db3 | 8220 | { |
29f59db3 | 8221 | /* now it should be safe to free those cfs_rqs */ |
6f505b16 | 8222 | free_sched_group(container_of(rhp, struct task_group, rcu)); |
29f59db3 SV |
8223 | } |
8224 | ||
9b5b7751 | 8225 | /* Destroy runqueue etc associated with a task group */ |
4cf86d77 | 8226 | void sched_destroy_group(struct task_group *tg) |
29f59db3 | 8227 | { |
8ed36996 | 8228 | unsigned long flags; |
9b5b7751 | 8229 | int i; |
29f59db3 | 8230 | |
8ed36996 | 8231 | spin_lock_irqsave(&task_group_lock, flags); |
9b5b7751 | 8232 | for_each_possible_cpu(i) { |
bccbe08a PZ |
8233 | unregister_fair_sched_group(tg, i); |
8234 | unregister_rt_sched_group(tg, i); | |
9b5b7751 | 8235 | } |
6f505b16 | 8236 | list_del_rcu(&tg->list); |
f473aa5e | 8237 | list_del_rcu(&tg->siblings); |
8ed36996 | 8238 | spin_unlock_irqrestore(&task_group_lock, flags); |
9b5b7751 | 8239 | |
9b5b7751 | 8240 | /* wait for possible concurrent references to cfs_rqs complete */ |
6f505b16 | 8241 | call_rcu(&tg->rcu, free_sched_group_rcu); |
29f59db3 SV |
8242 | } |
8243 | ||
9b5b7751 | 8244 | /* change task's runqueue when it moves between groups. |
3a252015 IM |
8245 | * The caller of this function should have put the task in its new group |
8246 | * by now. This function just updates tsk->se.cfs_rq and tsk->se.parent to | |
8247 | * reflect its new group. | |
9b5b7751 SV |
8248 | */ |
8249 | void sched_move_task(struct task_struct *tsk) | |
29f59db3 SV |
8250 | { |
8251 | int on_rq, running; | |
8252 | unsigned long flags; | |
8253 | struct rq *rq; | |
8254 | ||
8255 | rq = task_rq_lock(tsk, &flags); | |
8256 | ||
29f59db3 SV |
8257 | update_rq_clock(rq); |
8258 | ||
051a1d1a | 8259 | running = task_current(rq, tsk); |
29f59db3 SV |
8260 | on_rq = tsk->se.on_rq; |
8261 | ||
0e1f3483 | 8262 | if (on_rq) |
29f59db3 | 8263 | dequeue_task(rq, tsk, 0); |
0e1f3483 HS |
8264 | if (unlikely(running)) |
8265 | tsk->sched_class->put_prev_task(rq, tsk); | |
29f59db3 | 8266 | |
6f505b16 | 8267 | set_task_rq(tsk, task_cpu(tsk)); |
29f59db3 | 8268 | |
810b3817 PZ |
8269 | #ifdef CONFIG_FAIR_GROUP_SCHED |
8270 | if (tsk->sched_class->moved_group) | |
88ec22d3 | 8271 | tsk->sched_class->moved_group(tsk, on_rq); |
810b3817 PZ |
8272 | #endif |
8273 | ||
0e1f3483 HS |
8274 | if (unlikely(running)) |
8275 | tsk->sched_class->set_curr_task(rq); | |
8276 | if (on_rq) | |
ea87bb78 | 8277 | enqueue_task(rq, tsk, 0, false); |
29f59db3 | 8278 | |
29f59db3 SV |
8279 | task_rq_unlock(rq, &flags); |
8280 | } | |
7c941438 | 8281 | #endif /* CONFIG_CGROUP_SCHED */ |
29f59db3 | 8282 | |
052f1dc7 | 8283 | #ifdef CONFIG_FAIR_GROUP_SCHED |
c09595f6 | 8284 | static void __set_se_shares(struct sched_entity *se, unsigned long shares) |
29f59db3 SV |
8285 | { |
8286 | struct cfs_rq *cfs_rq = se->cfs_rq; | |
29f59db3 SV |
8287 | int on_rq; |
8288 | ||
29f59db3 | 8289 | on_rq = se->on_rq; |
62fb1851 | 8290 | if (on_rq) |
29f59db3 SV |
8291 | dequeue_entity(cfs_rq, se, 0); |
8292 | ||
8293 | se->load.weight = shares; | |
e05510d0 | 8294 | se->load.inv_weight = 0; |
29f59db3 | 8295 | |
62fb1851 | 8296 | if (on_rq) |
29f59db3 | 8297 | enqueue_entity(cfs_rq, se, 0); |
c09595f6 | 8298 | } |
62fb1851 | 8299 | |
c09595f6 PZ |
8300 | static void set_se_shares(struct sched_entity *se, unsigned long shares) |
8301 | { | |
8302 | struct cfs_rq *cfs_rq = se->cfs_rq; | |
8303 | struct rq *rq = cfs_rq->rq; | |
8304 | unsigned long flags; | |
8305 | ||
05fa785c | 8306 | raw_spin_lock_irqsave(&rq->lock, flags); |
c09595f6 | 8307 | __set_se_shares(se, shares); |
05fa785c | 8308 | raw_spin_unlock_irqrestore(&rq->lock, flags); |
29f59db3 SV |
8309 | } |
8310 | ||
8ed36996 PZ |
8311 | static DEFINE_MUTEX(shares_mutex); |
8312 | ||
4cf86d77 | 8313 | int sched_group_set_shares(struct task_group *tg, unsigned long shares) |
29f59db3 SV |
8314 | { |
8315 | int i; | |
8ed36996 | 8316 | unsigned long flags; |
c61935fd | 8317 | |
ec7dc8ac DG |
8318 | /* |
8319 | * We can't change the weight of the root cgroup. | |
8320 | */ | |
8321 | if (!tg->se[0]) | |
8322 | return -EINVAL; | |
8323 | ||
18d95a28 PZ |
8324 | if (shares < MIN_SHARES) |
8325 | shares = MIN_SHARES; | |
cb4ad1ff MX |
8326 | else if (shares > MAX_SHARES) |
8327 | shares = MAX_SHARES; | |
62fb1851 | 8328 | |
8ed36996 | 8329 | mutex_lock(&shares_mutex); |
9b5b7751 | 8330 | if (tg->shares == shares) |
5cb350ba | 8331 | goto done; |
29f59db3 | 8332 | |
8ed36996 | 8333 | spin_lock_irqsave(&task_group_lock, flags); |
bccbe08a PZ |
8334 | for_each_possible_cpu(i) |
8335 | unregister_fair_sched_group(tg, i); | |
f473aa5e | 8336 | list_del_rcu(&tg->siblings); |
8ed36996 | 8337 | spin_unlock_irqrestore(&task_group_lock, flags); |
6b2d7700 SV |
8338 | |
8339 | /* wait for any ongoing reference to this group to finish */ | |
8340 | synchronize_sched(); | |
8341 | ||
8342 | /* | |
8343 | * Now we are free to modify the group's share on each cpu | |
8344 | * w/o tripping rebalance_share or load_balance_fair. | |
8345 | */ | |
9b5b7751 | 8346 | tg->shares = shares; |
c09595f6 PZ |
8347 | for_each_possible_cpu(i) { |
8348 | /* | |
8349 | * force a rebalance | |
8350 | */ | |
8351 | cfs_rq_set_shares(tg->cfs_rq[i], 0); | |
cb4ad1ff | 8352 | set_se_shares(tg->se[i], shares); |
c09595f6 | 8353 | } |
29f59db3 | 8354 | |
6b2d7700 SV |
8355 | /* |
8356 | * Enable load balance activity on this group, by inserting it back on | |
8357 | * each cpu's rq->leaf_cfs_rq_list. | |
8358 | */ | |
8ed36996 | 8359 | spin_lock_irqsave(&task_group_lock, flags); |
bccbe08a PZ |
8360 | for_each_possible_cpu(i) |
8361 | register_fair_sched_group(tg, i); | |
f473aa5e | 8362 | list_add_rcu(&tg->siblings, &tg->parent->children); |
8ed36996 | 8363 | spin_unlock_irqrestore(&task_group_lock, flags); |
5cb350ba | 8364 | done: |
8ed36996 | 8365 | mutex_unlock(&shares_mutex); |
9b5b7751 | 8366 | return 0; |
29f59db3 SV |
8367 | } |
8368 | ||
5cb350ba DG |
8369 | unsigned long sched_group_shares(struct task_group *tg) |
8370 | { | |
8371 | return tg->shares; | |
8372 | } | |
052f1dc7 | 8373 | #endif |
5cb350ba | 8374 | |
052f1dc7 | 8375 | #ifdef CONFIG_RT_GROUP_SCHED |
6f505b16 | 8376 | /* |
9f0c1e56 | 8377 | * Ensure that the real time constraints are schedulable. |
6f505b16 | 8378 | */ |
9f0c1e56 PZ |
8379 | static DEFINE_MUTEX(rt_constraints_mutex); |
8380 | ||
8381 | static unsigned long to_ratio(u64 period, u64 runtime) | |
8382 | { | |
8383 | if (runtime == RUNTIME_INF) | |
9a7e0b18 | 8384 | return 1ULL << 20; |
9f0c1e56 | 8385 | |
9a7e0b18 | 8386 | return div64_u64(runtime << 20, period); |
9f0c1e56 PZ |
8387 | } |
8388 | ||
9a7e0b18 PZ |
8389 | /* Must be called with tasklist_lock held */ |
8390 | static inline int tg_has_rt_tasks(struct task_group *tg) | |
b40b2e8e | 8391 | { |
9a7e0b18 | 8392 | struct task_struct *g, *p; |
b40b2e8e | 8393 | |
9a7e0b18 PZ |
8394 | do_each_thread(g, p) { |
8395 | if (rt_task(p) && rt_rq_of_se(&p->rt)->tg == tg) | |
8396 | return 1; | |
8397 | } while_each_thread(g, p); | |
b40b2e8e | 8398 | |
9a7e0b18 PZ |
8399 | return 0; |
8400 | } | |
b40b2e8e | 8401 | |
9a7e0b18 PZ |
8402 | struct rt_schedulable_data { |
8403 | struct task_group *tg; | |
8404 | u64 rt_period; | |
8405 | u64 rt_runtime; | |
8406 | }; | |
b40b2e8e | 8407 | |
9a7e0b18 PZ |
8408 | static int tg_schedulable(struct task_group *tg, void *data) |
8409 | { | |
8410 | struct rt_schedulable_data *d = data; | |
8411 | struct task_group *child; | |
8412 | unsigned long total, sum = 0; | |
8413 | u64 period, runtime; | |
b40b2e8e | 8414 | |
9a7e0b18 PZ |
8415 | period = ktime_to_ns(tg->rt_bandwidth.rt_period); |
8416 | runtime = tg->rt_bandwidth.rt_runtime; | |
b40b2e8e | 8417 | |
9a7e0b18 PZ |
8418 | if (tg == d->tg) { |
8419 | period = d->rt_period; | |
8420 | runtime = d->rt_runtime; | |
b40b2e8e | 8421 | } |
b40b2e8e | 8422 | |
4653f803 PZ |
8423 | /* |
8424 | * Cannot have more runtime than the period. | |
8425 | */ | |
8426 | if (runtime > period && runtime != RUNTIME_INF) | |
8427 | return -EINVAL; | |
6f505b16 | 8428 | |
4653f803 PZ |
8429 | /* |
8430 | * Ensure we don't starve existing RT tasks. | |
8431 | */ | |
9a7e0b18 PZ |
8432 | if (rt_bandwidth_enabled() && !runtime && tg_has_rt_tasks(tg)) |
8433 | return -EBUSY; | |
6f505b16 | 8434 | |
9a7e0b18 | 8435 | total = to_ratio(period, runtime); |
6f505b16 | 8436 | |
4653f803 PZ |
8437 | /* |
8438 | * Nobody can have more than the global setting allows. | |
8439 | */ | |
8440 | if (total > to_ratio(global_rt_period(), global_rt_runtime())) | |
8441 | return -EINVAL; | |
6f505b16 | 8442 | |
4653f803 PZ |
8443 | /* |
8444 | * The sum of our children's runtime should not exceed our own. | |
8445 | */ | |
9a7e0b18 PZ |
8446 | list_for_each_entry_rcu(child, &tg->children, siblings) { |
8447 | period = ktime_to_ns(child->rt_bandwidth.rt_period); | |
8448 | runtime = child->rt_bandwidth.rt_runtime; | |
6f505b16 | 8449 | |
9a7e0b18 PZ |
8450 | if (child == d->tg) { |
8451 | period = d->rt_period; | |
8452 | runtime = d->rt_runtime; | |
8453 | } | |
6f505b16 | 8454 | |
9a7e0b18 | 8455 | sum += to_ratio(period, runtime); |
9f0c1e56 | 8456 | } |
6f505b16 | 8457 | |
9a7e0b18 PZ |
8458 | if (sum > total) |
8459 | return -EINVAL; | |
8460 | ||
8461 | return 0; | |
6f505b16 PZ |
8462 | } |
8463 | ||
9a7e0b18 | 8464 | static int __rt_schedulable(struct task_group *tg, u64 period, u64 runtime) |
521f1a24 | 8465 | { |
9a7e0b18 PZ |
8466 | struct rt_schedulable_data data = { |
8467 | .tg = tg, | |
8468 | .rt_period = period, | |
8469 | .rt_runtime = runtime, | |
8470 | }; | |
8471 | ||
8472 | return walk_tg_tree(tg_schedulable, tg_nop, &data); | |
521f1a24 DG |
8473 | } |
8474 | ||
d0b27fa7 PZ |
8475 | static int tg_set_bandwidth(struct task_group *tg, |
8476 | u64 rt_period, u64 rt_runtime) | |
6f505b16 | 8477 | { |
ac086bc2 | 8478 | int i, err = 0; |
9f0c1e56 | 8479 | |
9f0c1e56 | 8480 | mutex_lock(&rt_constraints_mutex); |
521f1a24 | 8481 | read_lock(&tasklist_lock); |
9a7e0b18 PZ |
8482 | err = __rt_schedulable(tg, rt_period, rt_runtime); |
8483 | if (err) | |
9f0c1e56 | 8484 | goto unlock; |
ac086bc2 | 8485 | |
0986b11b | 8486 | raw_spin_lock_irq(&tg->rt_bandwidth.rt_runtime_lock); |
d0b27fa7 PZ |
8487 | tg->rt_bandwidth.rt_period = ns_to_ktime(rt_period); |
8488 | tg->rt_bandwidth.rt_runtime = rt_runtime; | |
ac086bc2 PZ |
8489 | |
8490 | for_each_possible_cpu(i) { | |
8491 | struct rt_rq *rt_rq = tg->rt_rq[i]; | |
8492 | ||
0986b11b | 8493 | raw_spin_lock(&rt_rq->rt_runtime_lock); |
ac086bc2 | 8494 | rt_rq->rt_runtime = rt_runtime; |
0986b11b | 8495 | raw_spin_unlock(&rt_rq->rt_runtime_lock); |
ac086bc2 | 8496 | } |
0986b11b | 8497 | raw_spin_unlock_irq(&tg->rt_bandwidth.rt_runtime_lock); |
9f0c1e56 | 8498 | unlock: |
521f1a24 | 8499 | read_unlock(&tasklist_lock); |
9f0c1e56 PZ |
8500 | mutex_unlock(&rt_constraints_mutex); |
8501 | ||
8502 | return err; | |
6f505b16 PZ |
8503 | } |
8504 | ||
d0b27fa7 PZ |
8505 | int sched_group_set_rt_runtime(struct task_group *tg, long rt_runtime_us) |
8506 | { | |
8507 | u64 rt_runtime, rt_period; | |
8508 | ||
8509 | rt_period = ktime_to_ns(tg->rt_bandwidth.rt_period); | |
8510 | rt_runtime = (u64)rt_runtime_us * NSEC_PER_USEC; | |
8511 | if (rt_runtime_us < 0) | |
8512 | rt_runtime = RUNTIME_INF; | |
8513 | ||
8514 | return tg_set_bandwidth(tg, rt_period, rt_runtime); | |
8515 | } | |
8516 | ||
9f0c1e56 PZ |
8517 | long sched_group_rt_runtime(struct task_group *tg) |
8518 | { | |
8519 | u64 rt_runtime_us; | |
8520 | ||
d0b27fa7 | 8521 | if (tg->rt_bandwidth.rt_runtime == RUNTIME_INF) |
9f0c1e56 PZ |
8522 | return -1; |
8523 | ||
d0b27fa7 | 8524 | rt_runtime_us = tg->rt_bandwidth.rt_runtime; |
9f0c1e56 PZ |
8525 | do_div(rt_runtime_us, NSEC_PER_USEC); |
8526 | return rt_runtime_us; | |
8527 | } | |
d0b27fa7 PZ |
8528 | |
8529 | int sched_group_set_rt_period(struct task_group *tg, long rt_period_us) | |
8530 | { | |
8531 | u64 rt_runtime, rt_period; | |
8532 | ||
8533 | rt_period = (u64)rt_period_us * NSEC_PER_USEC; | |
8534 | rt_runtime = tg->rt_bandwidth.rt_runtime; | |
8535 | ||
619b0488 R |
8536 | if (rt_period == 0) |
8537 | return -EINVAL; | |
8538 | ||
d0b27fa7 PZ |
8539 | return tg_set_bandwidth(tg, rt_period, rt_runtime); |
8540 | } | |
8541 | ||
8542 | long sched_group_rt_period(struct task_group *tg) | |
8543 | { | |
8544 | u64 rt_period_us; | |
8545 | ||
8546 | rt_period_us = ktime_to_ns(tg->rt_bandwidth.rt_period); | |
8547 | do_div(rt_period_us, NSEC_PER_USEC); | |
8548 | return rt_period_us; | |
8549 | } | |
8550 | ||
8551 | static int sched_rt_global_constraints(void) | |
8552 | { | |
4653f803 | 8553 | u64 runtime, period; |
d0b27fa7 PZ |
8554 | int ret = 0; |
8555 | ||
ec5d4989 HS |
8556 | if (sysctl_sched_rt_period <= 0) |
8557 | return -EINVAL; | |
8558 | ||
4653f803 PZ |
8559 | runtime = global_rt_runtime(); |
8560 | period = global_rt_period(); | |
8561 | ||
8562 | /* | |
8563 | * Sanity check on the sysctl variables. | |
8564 | */ | |
8565 | if (runtime > period && runtime != RUNTIME_INF) | |
8566 | return -EINVAL; | |
10b612f4 | 8567 | |
d0b27fa7 | 8568 | mutex_lock(&rt_constraints_mutex); |
9a7e0b18 | 8569 | read_lock(&tasklist_lock); |
4653f803 | 8570 | ret = __rt_schedulable(NULL, 0, 0); |
9a7e0b18 | 8571 | read_unlock(&tasklist_lock); |
d0b27fa7 PZ |
8572 | mutex_unlock(&rt_constraints_mutex); |
8573 | ||
8574 | return ret; | |
8575 | } | |
54e99124 DG |
8576 | |
8577 | int sched_rt_can_attach(struct task_group *tg, struct task_struct *tsk) | |
8578 | { | |
8579 | /* Don't accept realtime tasks when there is no way for them to run */ | |
8580 | if (rt_task(tsk) && tg->rt_bandwidth.rt_runtime == 0) | |
8581 | return 0; | |
8582 | ||
8583 | return 1; | |
8584 | } | |
8585 | ||
6d6bc0ad | 8586 | #else /* !CONFIG_RT_GROUP_SCHED */ |
d0b27fa7 PZ |
8587 | static int sched_rt_global_constraints(void) |
8588 | { | |
ac086bc2 PZ |
8589 | unsigned long flags; |
8590 | int i; | |
8591 | ||
ec5d4989 HS |
8592 | if (sysctl_sched_rt_period <= 0) |
8593 | return -EINVAL; | |
8594 | ||
60aa605d PZ |
8595 | /* |
8596 | * There's always some RT tasks in the root group | |
8597 | * -- migration, kstopmachine etc.. | |
8598 | */ | |
8599 | if (sysctl_sched_rt_runtime == 0) | |
8600 | return -EBUSY; | |
8601 | ||
0986b11b | 8602 | raw_spin_lock_irqsave(&def_rt_bandwidth.rt_runtime_lock, flags); |
ac086bc2 PZ |
8603 | for_each_possible_cpu(i) { |
8604 | struct rt_rq *rt_rq = &cpu_rq(i)->rt; | |
8605 | ||
0986b11b | 8606 | raw_spin_lock(&rt_rq->rt_runtime_lock); |
ac086bc2 | 8607 | rt_rq->rt_runtime = global_rt_runtime(); |
0986b11b | 8608 | raw_spin_unlock(&rt_rq->rt_runtime_lock); |
ac086bc2 | 8609 | } |
0986b11b | 8610 | raw_spin_unlock_irqrestore(&def_rt_bandwidth.rt_runtime_lock, flags); |
ac086bc2 | 8611 | |
d0b27fa7 PZ |
8612 | return 0; |
8613 | } | |
6d6bc0ad | 8614 | #endif /* CONFIG_RT_GROUP_SCHED */ |
d0b27fa7 PZ |
8615 | |
8616 | int sched_rt_handler(struct ctl_table *table, int write, | |
8d65af78 | 8617 | void __user *buffer, size_t *lenp, |
d0b27fa7 PZ |
8618 | loff_t *ppos) |
8619 | { | |
8620 | int ret; | |
8621 | int old_period, old_runtime; | |
8622 | static DEFINE_MUTEX(mutex); | |
8623 | ||
8624 | mutex_lock(&mutex); | |
8625 | old_period = sysctl_sched_rt_period; | |
8626 | old_runtime = sysctl_sched_rt_runtime; | |
8627 | ||
8d65af78 | 8628 | ret = proc_dointvec(table, write, buffer, lenp, ppos); |
d0b27fa7 PZ |
8629 | |
8630 | if (!ret && write) { | |
8631 | ret = sched_rt_global_constraints(); | |
8632 | if (ret) { | |
8633 | sysctl_sched_rt_period = old_period; | |
8634 | sysctl_sched_rt_runtime = old_runtime; | |
8635 | } else { | |
8636 | def_rt_bandwidth.rt_runtime = global_rt_runtime(); | |
8637 | def_rt_bandwidth.rt_period = | |
8638 | ns_to_ktime(global_rt_period()); | |
8639 | } | |
8640 | } | |
8641 | mutex_unlock(&mutex); | |
8642 | ||
8643 | return ret; | |
8644 | } | |
68318b8e | 8645 | |
052f1dc7 | 8646 | #ifdef CONFIG_CGROUP_SCHED |
68318b8e SV |
8647 | |
8648 | /* return corresponding task_group object of a cgroup */ | |
2b01dfe3 | 8649 | static inline struct task_group *cgroup_tg(struct cgroup *cgrp) |
68318b8e | 8650 | { |
2b01dfe3 PM |
8651 | return container_of(cgroup_subsys_state(cgrp, cpu_cgroup_subsys_id), |
8652 | struct task_group, css); | |
68318b8e SV |
8653 | } |
8654 | ||
8655 | static struct cgroup_subsys_state * | |
2b01dfe3 | 8656 | cpu_cgroup_create(struct cgroup_subsys *ss, struct cgroup *cgrp) |
68318b8e | 8657 | { |
ec7dc8ac | 8658 | struct task_group *tg, *parent; |
68318b8e | 8659 | |
2b01dfe3 | 8660 | if (!cgrp->parent) { |
68318b8e | 8661 | /* This is early initialization for the top cgroup */ |
68318b8e SV |
8662 | return &init_task_group.css; |
8663 | } | |
8664 | ||
ec7dc8ac DG |
8665 | parent = cgroup_tg(cgrp->parent); |
8666 | tg = sched_create_group(parent); | |
68318b8e SV |
8667 | if (IS_ERR(tg)) |
8668 | return ERR_PTR(-ENOMEM); | |
8669 | ||
68318b8e SV |
8670 | return &tg->css; |
8671 | } | |
8672 | ||
41a2d6cf IM |
8673 | static void |
8674 | cpu_cgroup_destroy(struct cgroup_subsys *ss, struct cgroup *cgrp) | |
68318b8e | 8675 | { |
2b01dfe3 | 8676 | struct task_group *tg = cgroup_tg(cgrp); |
68318b8e SV |
8677 | |
8678 | sched_destroy_group(tg); | |
8679 | } | |
8680 | ||
41a2d6cf | 8681 | static int |
be367d09 | 8682 | cpu_cgroup_can_attach_task(struct cgroup *cgrp, struct task_struct *tsk) |
68318b8e | 8683 | { |
b68aa230 | 8684 | #ifdef CONFIG_RT_GROUP_SCHED |
54e99124 | 8685 | if (!sched_rt_can_attach(cgroup_tg(cgrp), tsk)) |
b68aa230 PZ |
8686 | return -EINVAL; |
8687 | #else | |
68318b8e SV |
8688 | /* We don't support RT-tasks being in separate groups */ |
8689 | if (tsk->sched_class != &fair_sched_class) | |
8690 | return -EINVAL; | |
b68aa230 | 8691 | #endif |
be367d09 BB |
8692 | return 0; |
8693 | } | |
68318b8e | 8694 | |
be367d09 BB |
8695 | static int |
8696 | cpu_cgroup_can_attach(struct cgroup_subsys *ss, struct cgroup *cgrp, | |
8697 | struct task_struct *tsk, bool threadgroup) | |
8698 | { | |
8699 | int retval = cpu_cgroup_can_attach_task(cgrp, tsk); | |
8700 | if (retval) | |
8701 | return retval; | |
8702 | if (threadgroup) { | |
8703 | struct task_struct *c; | |
8704 | rcu_read_lock(); | |
8705 | list_for_each_entry_rcu(c, &tsk->thread_group, thread_group) { | |
8706 | retval = cpu_cgroup_can_attach_task(cgrp, c); | |
8707 | if (retval) { | |
8708 | rcu_read_unlock(); | |
8709 | return retval; | |
8710 | } | |
8711 | } | |
8712 | rcu_read_unlock(); | |
8713 | } | |
68318b8e SV |
8714 | return 0; |
8715 | } | |
8716 | ||
8717 | static void | |
2b01dfe3 | 8718 | cpu_cgroup_attach(struct cgroup_subsys *ss, struct cgroup *cgrp, |
be367d09 BB |
8719 | struct cgroup *old_cont, struct task_struct *tsk, |
8720 | bool threadgroup) | |
68318b8e SV |
8721 | { |
8722 | sched_move_task(tsk); | |
be367d09 BB |
8723 | if (threadgroup) { |
8724 | struct task_struct *c; | |
8725 | rcu_read_lock(); | |
8726 | list_for_each_entry_rcu(c, &tsk->thread_group, thread_group) { | |
8727 | sched_move_task(c); | |
8728 | } | |
8729 | rcu_read_unlock(); | |
8730 | } | |
68318b8e SV |
8731 | } |
8732 | ||
052f1dc7 | 8733 | #ifdef CONFIG_FAIR_GROUP_SCHED |
f4c753b7 | 8734 | static int cpu_shares_write_u64(struct cgroup *cgrp, struct cftype *cftype, |
2b01dfe3 | 8735 | u64 shareval) |
68318b8e | 8736 | { |
2b01dfe3 | 8737 | return sched_group_set_shares(cgroup_tg(cgrp), shareval); |
68318b8e SV |
8738 | } |
8739 | ||
f4c753b7 | 8740 | static u64 cpu_shares_read_u64(struct cgroup *cgrp, struct cftype *cft) |
68318b8e | 8741 | { |
2b01dfe3 | 8742 | struct task_group *tg = cgroup_tg(cgrp); |
68318b8e SV |
8743 | |
8744 | return (u64) tg->shares; | |
8745 | } | |
6d6bc0ad | 8746 | #endif /* CONFIG_FAIR_GROUP_SCHED */ |
68318b8e | 8747 | |
052f1dc7 | 8748 | #ifdef CONFIG_RT_GROUP_SCHED |
0c70814c | 8749 | static int cpu_rt_runtime_write(struct cgroup *cgrp, struct cftype *cft, |
06ecb27c | 8750 | s64 val) |
6f505b16 | 8751 | { |
06ecb27c | 8752 | return sched_group_set_rt_runtime(cgroup_tg(cgrp), val); |
6f505b16 PZ |
8753 | } |
8754 | ||
06ecb27c | 8755 | static s64 cpu_rt_runtime_read(struct cgroup *cgrp, struct cftype *cft) |
6f505b16 | 8756 | { |
06ecb27c | 8757 | return sched_group_rt_runtime(cgroup_tg(cgrp)); |
6f505b16 | 8758 | } |
d0b27fa7 PZ |
8759 | |
8760 | static int cpu_rt_period_write_uint(struct cgroup *cgrp, struct cftype *cftype, | |
8761 | u64 rt_period_us) | |
8762 | { | |
8763 | return sched_group_set_rt_period(cgroup_tg(cgrp), rt_period_us); | |
8764 | } | |
8765 | ||
8766 | static u64 cpu_rt_period_read_uint(struct cgroup *cgrp, struct cftype *cft) | |
8767 | { | |
8768 | return sched_group_rt_period(cgroup_tg(cgrp)); | |
8769 | } | |
6d6bc0ad | 8770 | #endif /* CONFIG_RT_GROUP_SCHED */ |
6f505b16 | 8771 | |
fe5c7cc2 | 8772 | static struct cftype cpu_files[] = { |
052f1dc7 | 8773 | #ifdef CONFIG_FAIR_GROUP_SCHED |
fe5c7cc2 PM |
8774 | { |
8775 | .name = "shares", | |
f4c753b7 PM |
8776 | .read_u64 = cpu_shares_read_u64, |
8777 | .write_u64 = cpu_shares_write_u64, | |
fe5c7cc2 | 8778 | }, |
052f1dc7 PZ |
8779 | #endif |
8780 | #ifdef CONFIG_RT_GROUP_SCHED | |
6f505b16 | 8781 | { |
9f0c1e56 | 8782 | .name = "rt_runtime_us", |
06ecb27c PM |
8783 | .read_s64 = cpu_rt_runtime_read, |
8784 | .write_s64 = cpu_rt_runtime_write, | |
6f505b16 | 8785 | }, |
d0b27fa7 PZ |
8786 | { |
8787 | .name = "rt_period_us", | |
f4c753b7 PM |
8788 | .read_u64 = cpu_rt_period_read_uint, |
8789 | .write_u64 = cpu_rt_period_write_uint, | |
d0b27fa7 | 8790 | }, |
052f1dc7 | 8791 | #endif |
68318b8e SV |
8792 | }; |
8793 | ||
8794 | static int cpu_cgroup_populate(struct cgroup_subsys *ss, struct cgroup *cont) | |
8795 | { | |
fe5c7cc2 | 8796 | return cgroup_add_files(cont, ss, cpu_files, ARRAY_SIZE(cpu_files)); |
68318b8e SV |
8797 | } |
8798 | ||
8799 | struct cgroup_subsys cpu_cgroup_subsys = { | |
38605cae IM |
8800 | .name = "cpu", |
8801 | .create = cpu_cgroup_create, | |
8802 | .destroy = cpu_cgroup_destroy, | |
8803 | .can_attach = cpu_cgroup_can_attach, | |
8804 | .attach = cpu_cgroup_attach, | |
8805 | .populate = cpu_cgroup_populate, | |
8806 | .subsys_id = cpu_cgroup_subsys_id, | |
68318b8e SV |
8807 | .early_init = 1, |
8808 | }; | |
8809 | ||
052f1dc7 | 8810 | #endif /* CONFIG_CGROUP_SCHED */ |
d842de87 SV |
8811 | |
8812 | #ifdef CONFIG_CGROUP_CPUACCT | |
8813 | ||
8814 | /* | |
8815 | * CPU accounting code for task groups. | |
8816 | * | |
8817 | * Based on the work by Paul Menage (menage@google.com) and Balbir Singh | |
8818 | * (balbir@in.ibm.com). | |
8819 | */ | |
8820 | ||
934352f2 | 8821 | /* track cpu usage of a group of tasks and its child groups */ |
d842de87 SV |
8822 | struct cpuacct { |
8823 | struct cgroup_subsys_state css; | |
8824 | /* cpuusage holds pointer to a u64-type object on every cpu */ | |
43cf38eb | 8825 | u64 __percpu *cpuusage; |
ef12fefa | 8826 | struct percpu_counter cpustat[CPUACCT_STAT_NSTATS]; |
934352f2 | 8827 | struct cpuacct *parent; |
d842de87 SV |
8828 | }; |
8829 | ||
8830 | struct cgroup_subsys cpuacct_subsys; | |
8831 | ||
8832 | /* return cpu accounting group corresponding to this container */ | |
32cd756a | 8833 | static inline struct cpuacct *cgroup_ca(struct cgroup *cgrp) |
d842de87 | 8834 | { |
32cd756a | 8835 | return container_of(cgroup_subsys_state(cgrp, cpuacct_subsys_id), |
d842de87 SV |
8836 | struct cpuacct, css); |
8837 | } | |
8838 | ||
8839 | /* return cpu accounting group to which this task belongs */ | |
8840 | static inline struct cpuacct *task_ca(struct task_struct *tsk) | |
8841 | { | |
8842 | return container_of(task_subsys_state(tsk, cpuacct_subsys_id), | |
8843 | struct cpuacct, css); | |
8844 | } | |
8845 | ||
8846 | /* create a new cpu accounting group */ | |
8847 | static struct cgroup_subsys_state *cpuacct_create( | |
32cd756a | 8848 | struct cgroup_subsys *ss, struct cgroup *cgrp) |
d842de87 SV |
8849 | { |
8850 | struct cpuacct *ca = kzalloc(sizeof(*ca), GFP_KERNEL); | |
ef12fefa | 8851 | int i; |
d842de87 SV |
8852 | |
8853 | if (!ca) | |
ef12fefa | 8854 | goto out; |
d842de87 SV |
8855 | |
8856 | ca->cpuusage = alloc_percpu(u64); | |
ef12fefa BR |
8857 | if (!ca->cpuusage) |
8858 | goto out_free_ca; | |
8859 | ||
8860 | for (i = 0; i < CPUACCT_STAT_NSTATS; i++) | |
8861 | if (percpu_counter_init(&ca->cpustat[i], 0)) | |
8862 | goto out_free_counters; | |
d842de87 | 8863 | |
934352f2 BR |
8864 | if (cgrp->parent) |
8865 | ca->parent = cgroup_ca(cgrp->parent); | |
8866 | ||
d842de87 | 8867 | return &ca->css; |
ef12fefa BR |
8868 | |
8869 | out_free_counters: | |
8870 | while (--i >= 0) | |
8871 | percpu_counter_destroy(&ca->cpustat[i]); | |
8872 | free_percpu(ca->cpuusage); | |
8873 | out_free_ca: | |
8874 | kfree(ca); | |
8875 | out: | |
8876 | return ERR_PTR(-ENOMEM); | |
d842de87 SV |
8877 | } |
8878 | ||
8879 | /* destroy an existing cpu accounting group */ | |
41a2d6cf | 8880 | static void |
32cd756a | 8881 | cpuacct_destroy(struct cgroup_subsys *ss, struct cgroup *cgrp) |
d842de87 | 8882 | { |
32cd756a | 8883 | struct cpuacct *ca = cgroup_ca(cgrp); |
ef12fefa | 8884 | int i; |
d842de87 | 8885 | |
ef12fefa BR |
8886 | for (i = 0; i < CPUACCT_STAT_NSTATS; i++) |
8887 | percpu_counter_destroy(&ca->cpustat[i]); | |
d842de87 SV |
8888 | free_percpu(ca->cpuusage); |
8889 | kfree(ca); | |
8890 | } | |
8891 | ||
720f5498 KC |
8892 | static u64 cpuacct_cpuusage_read(struct cpuacct *ca, int cpu) |
8893 | { | |
b36128c8 | 8894 | u64 *cpuusage = per_cpu_ptr(ca->cpuusage, cpu); |
720f5498 KC |
8895 | u64 data; |
8896 | ||
8897 | #ifndef CONFIG_64BIT | |
8898 | /* | |
8899 | * Take rq->lock to make 64-bit read safe on 32-bit platforms. | |
8900 | */ | |
05fa785c | 8901 | raw_spin_lock_irq(&cpu_rq(cpu)->lock); |
720f5498 | 8902 | data = *cpuusage; |
05fa785c | 8903 | raw_spin_unlock_irq(&cpu_rq(cpu)->lock); |
720f5498 KC |
8904 | #else |
8905 | data = *cpuusage; | |
8906 | #endif | |
8907 | ||
8908 | return data; | |
8909 | } | |
8910 | ||
8911 | static void cpuacct_cpuusage_write(struct cpuacct *ca, int cpu, u64 val) | |
8912 | { | |
b36128c8 | 8913 | u64 *cpuusage = per_cpu_ptr(ca->cpuusage, cpu); |
720f5498 KC |
8914 | |
8915 | #ifndef CONFIG_64BIT | |
8916 | /* | |
8917 | * Take rq->lock to make 64-bit write safe on 32-bit platforms. | |
8918 | */ | |
05fa785c | 8919 | raw_spin_lock_irq(&cpu_rq(cpu)->lock); |
720f5498 | 8920 | *cpuusage = val; |
05fa785c | 8921 | raw_spin_unlock_irq(&cpu_rq(cpu)->lock); |
720f5498 KC |
8922 | #else |
8923 | *cpuusage = val; | |
8924 | #endif | |
8925 | } | |
8926 | ||
d842de87 | 8927 | /* return total cpu usage (in nanoseconds) of a group */ |
32cd756a | 8928 | static u64 cpuusage_read(struct cgroup *cgrp, struct cftype *cft) |
d842de87 | 8929 | { |
32cd756a | 8930 | struct cpuacct *ca = cgroup_ca(cgrp); |
d842de87 SV |
8931 | u64 totalcpuusage = 0; |
8932 | int i; | |
8933 | ||
720f5498 KC |
8934 | for_each_present_cpu(i) |
8935 | totalcpuusage += cpuacct_cpuusage_read(ca, i); | |
d842de87 SV |
8936 | |
8937 | return totalcpuusage; | |
8938 | } | |
8939 | ||
0297b803 DG |
8940 | static int cpuusage_write(struct cgroup *cgrp, struct cftype *cftype, |
8941 | u64 reset) | |
8942 | { | |
8943 | struct cpuacct *ca = cgroup_ca(cgrp); | |
8944 | int err = 0; | |
8945 | int i; | |
8946 | ||
8947 | if (reset) { | |
8948 | err = -EINVAL; | |
8949 | goto out; | |
8950 | } | |
8951 | ||
720f5498 KC |
8952 | for_each_present_cpu(i) |
8953 | cpuacct_cpuusage_write(ca, i, 0); | |
0297b803 | 8954 | |
0297b803 DG |
8955 | out: |
8956 | return err; | |
8957 | } | |
8958 | ||
e9515c3c KC |
8959 | static int cpuacct_percpu_seq_read(struct cgroup *cgroup, struct cftype *cft, |
8960 | struct seq_file *m) | |
8961 | { | |
8962 | struct cpuacct *ca = cgroup_ca(cgroup); | |
8963 | u64 percpu; | |
8964 | int i; | |
8965 | ||
8966 | for_each_present_cpu(i) { | |
8967 | percpu = cpuacct_cpuusage_read(ca, i); | |
8968 | seq_printf(m, "%llu ", (unsigned long long) percpu); | |
8969 | } | |
8970 | seq_printf(m, "\n"); | |
8971 | return 0; | |
8972 | } | |
8973 | ||
ef12fefa BR |
8974 | static const char *cpuacct_stat_desc[] = { |
8975 | [CPUACCT_STAT_USER] = "user", | |
8976 | [CPUACCT_STAT_SYSTEM] = "system", | |
8977 | }; | |
8978 | ||
8979 | static int cpuacct_stats_show(struct cgroup *cgrp, struct cftype *cft, | |
8980 | struct cgroup_map_cb *cb) | |
8981 | { | |
8982 | struct cpuacct *ca = cgroup_ca(cgrp); | |
8983 | int i; | |
8984 | ||
8985 | for (i = 0; i < CPUACCT_STAT_NSTATS; i++) { | |
8986 | s64 val = percpu_counter_read(&ca->cpustat[i]); | |
8987 | val = cputime64_to_clock_t(val); | |
8988 | cb->fill(cb, cpuacct_stat_desc[i], val); | |
8989 | } | |
8990 | return 0; | |
8991 | } | |
8992 | ||
d842de87 SV |
8993 | static struct cftype files[] = { |
8994 | { | |
8995 | .name = "usage", | |
f4c753b7 PM |
8996 | .read_u64 = cpuusage_read, |
8997 | .write_u64 = cpuusage_write, | |
d842de87 | 8998 | }, |
e9515c3c KC |
8999 | { |
9000 | .name = "usage_percpu", | |
9001 | .read_seq_string = cpuacct_percpu_seq_read, | |
9002 | }, | |
ef12fefa BR |
9003 | { |
9004 | .name = "stat", | |
9005 | .read_map = cpuacct_stats_show, | |
9006 | }, | |
d842de87 SV |
9007 | }; |
9008 | ||
32cd756a | 9009 | static int cpuacct_populate(struct cgroup_subsys *ss, struct cgroup *cgrp) |
d842de87 | 9010 | { |
32cd756a | 9011 | return cgroup_add_files(cgrp, ss, files, ARRAY_SIZE(files)); |
d842de87 SV |
9012 | } |
9013 | ||
9014 | /* | |
9015 | * charge this task's execution time to its accounting group. | |
9016 | * | |
9017 | * called with rq->lock held. | |
9018 | */ | |
9019 | static void cpuacct_charge(struct task_struct *tsk, u64 cputime) | |
9020 | { | |
9021 | struct cpuacct *ca; | |
934352f2 | 9022 | int cpu; |
d842de87 | 9023 | |
c40c6f85 | 9024 | if (unlikely(!cpuacct_subsys.active)) |
d842de87 SV |
9025 | return; |
9026 | ||
934352f2 | 9027 | cpu = task_cpu(tsk); |
a18b83b7 BR |
9028 | |
9029 | rcu_read_lock(); | |
9030 | ||
d842de87 | 9031 | ca = task_ca(tsk); |
d842de87 | 9032 | |
934352f2 | 9033 | for (; ca; ca = ca->parent) { |
b36128c8 | 9034 | u64 *cpuusage = per_cpu_ptr(ca->cpuusage, cpu); |
d842de87 SV |
9035 | *cpuusage += cputime; |
9036 | } | |
a18b83b7 BR |
9037 | |
9038 | rcu_read_unlock(); | |
d842de87 SV |
9039 | } |
9040 | ||
fa535a77 AB |
9041 | /* |
9042 | * When CONFIG_VIRT_CPU_ACCOUNTING is enabled one jiffy can be very large | |
9043 | * in cputime_t units. As a result, cpuacct_update_stats calls | |
9044 | * percpu_counter_add with values large enough to always overflow the | |
9045 | * per cpu batch limit causing bad SMP scalability. | |
9046 | * | |
9047 | * To fix this we scale percpu_counter_batch by cputime_one_jiffy so we | |
9048 | * batch the same amount of time with CONFIG_VIRT_CPU_ACCOUNTING disabled | |
9049 | * and enabled. We cap it at INT_MAX which is the largest allowed batch value. | |
9050 | */ | |
9051 | #ifdef CONFIG_SMP | |
9052 | #define CPUACCT_BATCH \ | |
9053 | min_t(long, percpu_counter_batch * cputime_one_jiffy, INT_MAX) | |
9054 | #else | |
9055 | #define CPUACCT_BATCH 0 | |
9056 | #endif | |
9057 | ||
ef12fefa BR |
9058 | /* |
9059 | * Charge the system/user time to the task's accounting group. | |
9060 | */ | |
9061 | static void cpuacct_update_stats(struct task_struct *tsk, | |
9062 | enum cpuacct_stat_index idx, cputime_t val) | |
9063 | { | |
9064 | struct cpuacct *ca; | |
fa535a77 | 9065 | int batch = CPUACCT_BATCH; |
ef12fefa BR |
9066 | |
9067 | if (unlikely(!cpuacct_subsys.active)) | |
9068 | return; | |
9069 | ||
9070 | rcu_read_lock(); | |
9071 | ca = task_ca(tsk); | |
9072 | ||
9073 | do { | |
fa535a77 | 9074 | __percpu_counter_add(&ca->cpustat[idx], val, batch); |
ef12fefa BR |
9075 | ca = ca->parent; |
9076 | } while (ca); | |
9077 | rcu_read_unlock(); | |
9078 | } | |
9079 | ||
d842de87 SV |
9080 | struct cgroup_subsys cpuacct_subsys = { |
9081 | .name = "cpuacct", | |
9082 | .create = cpuacct_create, | |
9083 | .destroy = cpuacct_destroy, | |
9084 | .populate = cpuacct_populate, | |
9085 | .subsys_id = cpuacct_subsys_id, | |
9086 | }; | |
9087 | #endif /* CONFIG_CGROUP_CPUACCT */ | |
03b042bf PM |
9088 | |
9089 | #ifndef CONFIG_SMP | |
9090 | ||
9091 | int rcu_expedited_torture_stats(char *page) | |
9092 | { | |
9093 | return 0; | |
9094 | } | |
9095 | EXPORT_SYMBOL_GPL(rcu_expedited_torture_stats); | |
9096 | ||
9097 | void synchronize_sched_expedited(void) | |
9098 | { | |
9099 | } | |
9100 | EXPORT_SYMBOL_GPL(synchronize_sched_expedited); | |
9101 | ||
9102 | #else /* #ifndef CONFIG_SMP */ | |
9103 | ||
9104 | static DEFINE_PER_CPU(struct migration_req, rcu_migration_req); | |
9105 | static DEFINE_MUTEX(rcu_sched_expedited_mutex); | |
9106 | ||
9107 | #define RCU_EXPEDITED_STATE_POST -2 | |
9108 | #define RCU_EXPEDITED_STATE_IDLE -1 | |
9109 | ||
9110 | static int rcu_expedited_state = RCU_EXPEDITED_STATE_IDLE; | |
9111 | ||
9112 | int rcu_expedited_torture_stats(char *page) | |
9113 | { | |
9114 | int cnt = 0; | |
9115 | int cpu; | |
9116 | ||
9117 | cnt += sprintf(&page[cnt], "state: %d /", rcu_expedited_state); | |
9118 | for_each_online_cpu(cpu) { | |
9119 | cnt += sprintf(&page[cnt], " %d:%d", | |
9120 | cpu, per_cpu(rcu_migration_req, cpu).dest_cpu); | |
9121 | } | |
9122 | cnt += sprintf(&page[cnt], "\n"); | |
9123 | return cnt; | |
9124 | } | |
9125 | EXPORT_SYMBOL_GPL(rcu_expedited_torture_stats); | |
9126 | ||
9127 | static long synchronize_sched_expedited_count; | |
9128 | ||
9129 | /* | |
9130 | * Wait for an rcu-sched grace period to elapse, but use "big hammer" | |
9131 | * approach to force grace period to end quickly. This consumes | |
9132 | * significant time on all CPUs, and is thus not recommended for | |
9133 | * any sort of common-case code. | |
9134 | * | |
9135 | * Note that it is illegal to call this function while holding any | |
9136 | * lock that is acquired by a CPU-hotplug notifier. Failing to | |
9137 | * observe this restriction will result in deadlock. | |
9138 | */ | |
9139 | void synchronize_sched_expedited(void) | |
9140 | { | |
9141 | int cpu; | |
9142 | unsigned long flags; | |
9143 | bool need_full_sync = 0; | |
9144 | struct rq *rq; | |
9145 | struct migration_req *req; | |
9146 | long snap; | |
9147 | int trycount = 0; | |
9148 | ||
9149 | smp_mb(); /* ensure prior mod happens before capturing snap. */ | |
9150 | snap = ACCESS_ONCE(synchronize_sched_expedited_count) + 1; | |
9151 | get_online_cpus(); | |
9152 | while (!mutex_trylock(&rcu_sched_expedited_mutex)) { | |
9153 | put_online_cpus(); | |
9154 | if (trycount++ < 10) | |
9155 | udelay(trycount * num_online_cpus()); | |
9156 | else { | |
9157 | synchronize_sched(); | |
9158 | return; | |
9159 | } | |
9160 | if (ACCESS_ONCE(synchronize_sched_expedited_count) - snap > 0) { | |
9161 | smp_mb(); /* ensure test happens before caller kfree */ | |
9162 | return; | |
9163 | } | |
9164 | get_online_cpus(); | |
9165 | } | |
9166 | rcu_expedited_state = RCU_EXPEDITED_STATE_POST; | |
9167 | for_each_online_cpu(cpu) { | |
9168 | rq = cpu_rq(cpu); | |
9169 | req = &per_cpu(rcu_migration_req, cpu); | |
9170 | init_completion(&req->done); | |
9171 | req->task = NULL; | |
9172 | req->dest_cpu = RCU_MIGRATION_NEED_QS; | |
05fa785c | 9173 | raw_spin_lock_irqsave(&rq->lock, flags); |
03b042bf | 9174 | list_add(&req->list, &rq->migration_queue); |
05fa785c | 9175 | raw_spin_unlock_irqrestore(&rq->lock, flags); |
03b042bf PM |
9176 | wake_up_process(rq->migration_thread); |
9177 | } | |
9178 | for_each_online_cpu(cpu) { | |
9179 | rcu_expedited_state = cpu; | |
9180 | req = &per_cpu(rcu_migration_req, cpu); | |
9181 | rq = cpu_rq(cpu); | |
9182 | wait_for_completion(&req->done); | |
05fa785c | 9183 | raw_spin_lock_irqsave(&rq->lock, flags); |
03b042bf PM |
9184 | if (unlikely(req->dest_cpu == RCU_MIGRATION_MUST_SYNC)) |
9185 | need_full_sync = 1; | |
9186 | req->dest_cpu = RCU_MIGRATION_IDLE; | |
05fa785c | 9187 | raw_spin_unlock_irqrestore(&rq->lock, flags); |
03b042bf PM |
9188 | } |
9189 | rcu_expedited_state = RCU_EXPEDITED_STATE_IDLE; | |
956539b7 | 9190 | synchronize_sched_expedited_count++; |
03b042bf PM |
9191 | mutex_unlock(&rcu_sched_expedited_mutex); |
9192 | put_online_cpus(); | |
9193 | if (need_full_sync) | |
9194 | synchronize_sched(); | |
9195 | } | |
9196 | EXPORT_SYMBOL_GPL(synchronize_sched_expedited); | |
9197 | ||
9198 | #endif /* #else #ifndef CONFIG_SMP */ |