Commit | Line | Data |
---|---|---|
1da177e4 | 1 | /* |
391e43da | 2 | * kernel/sched/core.c |
1da177e4 LT |
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 | 34 | #include <linux/highmem.h> |
1da177e4 LT |
35 | #include <asm/mmu_context.h> |
36 | #include <linux/interrupt.h> | |
c59ede7b | 37 | #include <linux/capability.h> |
1da177e4 LT |
38 | #include <linux/completion.h> |
39 | #include <linux/kernel_stat.h> | |
9a11b49a | 40 | #include <linux/debug_locks.h> |
cdd6c482 | 41 | #include <linux/perf_event.h> |
1da177e4 LT |
42 | #include <linux/security.h> |
43 | #include <linux/notifier.h> | |
44 | #include <linux/profile.h> | |
7dfb7103 | 45 | #include <linux/freezer.h> |
198e2f18 | 46 | #include <linux/vmalloc.h> |
1da177e4 LT |
47 | #include <linux/blkdev.h> |
48 | #include <linux/delay.h> | |
b488893a | 49 | #include <linux/pid_namespace.h> |
1da177e4 LT |
50 | #include <linux/smp.h> |
51 | #include <linux/threads.h> | |
52 | #include <linux/timer.h> | |
53 | #include <linux/rcupdate.h> | |
54 | #include <linux/cpu.h> | |
55 | #include <linux/cpuset.h> | |
56 | #include <linux/percpu.h> | |
b5aadf7f | 57 | #include <linux/proc_fs.h> |
1da177e4 | 58 | #include <linux/seq_file.h> |
e692ab53 | 59 | #include <linux/sysctl.h> |
1da177e4 LT |
60 | #include <linux/syscalls.h> |
61 | #include <linux/times.h> | |
8f0ab514 | 62 | #include <linux/tsacct_kern.h> |
c6fd91f0 | 63 | #include <linux/kprobes.h> |
0ff92245 | 64 | #include <linux/delayacct.h> |
dff06c15 | 65 | #include <linux/unistd.h> |
f5ff8422 | 66 | #include <linux/pagemap.h> |
8f4d37ec | 67 | #include <linux/hrtimer.h> |
30914a58 | 68 | #include <linux/tick.h> |
f00b45c1 PZ |
69 | #include <linux/debugfs.h> |
70 | #include <linux/ctype.h> | |
6cd8a4bb | 71 | #include <linux/ftrace.h> |
5a0e3ad6 | 72 | #include <linux/slab.h> |
f1c6f1a7 | 73 | #include <linux/init_task.h> |
40401530 | 74 | #include <linux/binfmts.h> |
91d1aa43 | 75 | #include <linux/context_tracking.h> |
52f5684c | 76 | #include <linux/compiler.h> |
1da177e4 | 77 | |
96f951ed | 78 | #include <asm/switch_to.h> |
5517d86b | 79 | #include <asm/tlb.h> |
838225b4 | 80 | #include <asm/irq_regs.h> |
db7e527d | 81 | #include <asm/mutex.h> |
e6e6685a GC |
82 | #ifdef CONFIG_PARAVIRT |
83 | #include <asm/paravirt.h> | |
84 | #endif | |
1da177e4 | 85 | |
029632fb | 86 | #include "sched.h" |
ea138446 | 87 | #include "../workqueue_internal.h" |
29d5e047 | 88 | #include "../smpboot.h" |
6e0534f2 | 89 | |
a8d154b0 | 90 | #define CREATE_TRACE_POINTS |
ad8d75ff | 91 | #include <trace/events/sched.h> |
a8d154b0 | 92 | |
febdbfe8 PZ |
93 | #ifdef smp_mb__before_atomic |
94 | void __smp_mb__before_atomic(void) | |
95 | { | |
96 | smp_mb__before_atomic(); | |
97 | } | |
98 | EXPORT_SYMBOL(__smp_mb__before_atomic); | |
99 | #endif | |
100 | ||
101 | #ifdef smp_mb__after_atomic | |
102 | void __smp_mb__after_atomic(void) | |
103 | { | |
104 | smp_mb__after_atomic(); | |
105 | } | |
106 | EXPORT_SYMBOL(__smp_mb__after_atomic); | |
107 | #endif | |
108 | ||
029632fb | 109 | void start_bandwidth_timer(struct hrtimer *period_timer, ktime_t period) |
d0b27fa7 | 110 | { |
58088ad0 PT |
111 | unsigned long delta; |
112 | ktime_t soft, hard, now; | |
d0b27fa7 | 113 | |
58088ad0 PT |
114 | for (;;) { |
115 | if (hrtimer_active(period_timer)) | |
116 | break; | |
117 | ||
118 | now = hrtimer_cb_get_time(period_timer); | |
119 | hrtimer_forward(period_timer, now, period); | |
d0b27fa7 | 120 | |
58088ad0 PT |
121 | soft = hrtimer_get_softexpires(period_timer); |
122 | hard = hrtimer_get_expires(period_timer); | |
123 | delta = ktime_to_ns(ktime_sub(hard, soft)); | |
124 | __hrtimer_start_range_ns(period_timer, soft, delta, | |
125 | HRTIMER_MODE_ABS_PINNED, 0); | |
126 | } | |
127 | } | |
128 | ||
029632fb PZ |
129 | DEFINE_MUTEX(sched_domains_mutex); |
130 | DEFINE_PER_CPU_SHARED_ALIGNED(struct rq, runqueues); | |
dc61b1d6 | 131 | |
fe44d621 | 132 | static void update_rq_clock_task(struct rq *rq, s64 delta); |
305e6835 | 133 | |
029632fb | 134 | void update_rq_clock(struct rq *rq) |
3e51f33f | 135 | { |
fe44d621 | 136 | s64 delta; |
305e6835 | 137 | |
61eadef6 | 138 | if (rq->skip_clock_update > 0) |
f26f9aff | 139 | return; |
aa483808 | 140 | |
fe44d621 PZ |
141 | delta = sched_clock_cpu(cpu_of(rq)) - rq->clock; |
142 | rq->clock += delta; | |
143 | update_rq_clock_task(rq, delta); | |
3e51f33f PZ |
144 | } |
145 | ||
bf5c91ba IM |
146 | /* |
147 | * Debugging: various feature bits | |
148 | */ | |
f00b45c1 | 149 | |
f00b45c1 PZ |
150 | #define SCHED_FEAT(name, enabled) \ |
151 | (1UL << __SCHED_FEAT_##name) * enabled | | |
152 | ||
bf5c91ba | 153 | const_debug unsigned int sysctl_sched_features = |
391e43da | 154 | #include "features.h" |
f00b45c1 PZ |
155 | 0; |
156 | ||
157 | #undef SCHED_FEAT | |
158 | ||
159 | #ifdef CONFIG_SCHED_DEBUG | |
160 | #define SCHED_FEAT(name, enabled) \ | |
161 | #name , | |
162 | ||
1292531f | 163 | static const char * const sched_feat_names[] = { |
391e43da | 164 | #include "features.h" |
f00b45c1 PZ |
165 | }; |
166 | ||
167 | #undef SCHED_FEAT | |
168 | ||
34f3a814 | 169 | static int sched_feat_show(struct seq_file *m, void *v) |
f00b45c1 | 170 | { |
f00b45c1 PZ |
171 | int i; |
172 | ||
f8b6d1cc | 173 | for (i = 0; i < __SCHED_FEAT_NR; i++) { |
34f3a814 LZ |
174 | if (!(sysctl_sched_features & (1UL << i))) |
175 | seq_puts(m, "NO_"); | |
176 | seq_printf(m, "%s ", sched_feat_names[i]); | |
f00b45c1 | 177 | } |
34f3a814 | 178 | seq_puts(m, "\n"); |
f00b45c1 | 179 | |
34f3a814 | 180 | return 0; |
f00b45c1 PZ |
181 | } |
182 | ||
f8b6d1cc PZ |
183 | #ifdef HAVE_JUMP_LABEL |
184 | ||
c5905afb IM |
185 | #define jump_label_key__true STATIC_KEY_INIT_TRUE |
186 | #define jump_label_key__false STATIC_KEY_INIT_FALSE | |
f8b6d1cc PZ |
187 | |
188 | #define SCHED_FEAT(name, enabled) \ | |
189 | jump_label_key__##enabled , | |
190 | ||
c5905afb | 191 | struct static_key sched_feat_keys[__SCHED_FEAT_NR] = { |
f8b6d1cc PZ |
192 | #include "features.h" |
193 | }; | |
194 | ||
195 | #undef SCHED_FEAT | |
196 | ||
197 | static void sched_feat_disable(int i) | |
198 | { | |
c5905afb IM |
199 | if (static_key_enabled(&sched_feat_keys[i])) |
200 | static_key_slow_dec(&sched_feat_keys[i]); | |
f8b6d1cc PZ |
201 | } |
202 | ||
203 | static void sched_feat_enable(int i) | |
204 | { | |
c5905afb IM |
205 | if (!static_key_enabled(&sched_feat_keys[i])) |
206 | static_key_slow_inc(&sched_feat_keys[i]); | |
f8b6d1cc PZ |
207 | } |
208 | #else | |
209 | static void sched_feat_disable(int i) { }; | |
210 | static void sched_feat_enable(int i) { }; | |
211 | #endif /* HAVE_JUMP_LABEL */ | |
212 | ||
1a687c2e | 213 | static int sched_feat_set(char *cmp) |
f00b45c1 | 214 | { |
f00b45c1 | 215 | int i; |
1a687c2e | 216 | int neg = 0; |
f00b45c1 | 217 | |
524429c3 | 218 | if (strncmp(cmp, "NO_", 3) == 0) { |
f00b45c1 PZ |
219 | neg = 1; |
220 | cmp += 3; | |
221 | } | |
222 | ||
f8b6d1cc | 223 | for (i = 0; i < __SCHED_FEAT_NR; i++) { |
7740191c | 224 | if (strcmp(cmp, sched_feat_names[i]) == 0) { |
f8b6d1cc | 225 | if (neg) { |
f00b45c1 | 226 | sysctl_sched_features &= ~(1UL << i); |
f8b6d1cc PZ |
227 | sched_feat_disable(i); |
228 | } else { | |
f00b45c1 | 229 | sysctl_sched_features |= (1UL << i); |
f8b6d1cc PZ |
230 | sched_feat_enable(i); |
231 | } | |
f00b45c1 PZ |
232 | break; |
233 | } | |
234 | } | |
235 | ||
1a687c2e MG |
236 | return i; |
237 | } | |
238 | ||
239 | static ssize_t | |
240 | sched_feat_write(struct file *filp, const char __user *ubuf, | |
241 | size_t cnt, loff_t *ppos) | |
242 | { | |
243 | char buf[64]; | |
244 | char *cmp; | |
245 | int i; | |
246 | ||
247 | if (cnt > 63) | |
248 | cnt = 63; | |
249 | ||
250 | if (copy_from_user(&buf, ubuf, cnt)) | |
251 | return -EFAULT; | |
252 | ||
253 | buf[cnt] = 0; | |
254 | cmp = strstrip(buf); | |
255 | ||
256 | i = sched_feat_set(cmp); | |
f8b6d1cc | 257 | if (i == __SCHED_FEAT_NR) |
f00b45c1 PZ |
258 | return -EINVAL; |
259 | ||
42994724 | 260 | *ppos += cnt; |
f00b45c1 PZ |
261 | |
262 | return cnt; | |
263 | } | |
264 | ||
34f3a814 LZ |
265 | static int sched_feat_open(struct inode *inode, struct file *filp) |
266 | { | |
267 | return single_open(filp, sched_feat_show, NULL); | |
268 | } | |
269 | ||
828c0950 | 270 | static const struct file_operations sched_feat_fops = { |
34f3a814 LZ |
271 | .open = sched_feat_open, |
272 | .write = sched_feat_write, | |
273 | .read = seq_read, | |
274 | .llseek = seq_lseek, | |
275 | .release = single_release, | |
f00b45c1 PZ |
276 | }; |
277 | ||
278 | static __init int sched_init_debug(void) | |
279 | { | |
f00b45c1 PZ |
280 | debugfs_create_file("sched_features", 0644, NULL, NULL, |
281 | &sched_feat_fops); | |
282 | ||
283 | return 0; | |
284 | } | |
285 | late_initcall(sched_init_debug); | |
f8b6d1cc | 286 | #endif /* CONFIG_SCHED_DEBUG */ |
bf5c91ba | 287 | |
b82d9fdd PZ |
288 | /* |
289 | * Number of tasks to iterate in a single balance run. | |
290 | * Limited because this is done with IRQs disabled. | |
291 | */ | |
292 | const_debug unsigned int sysctl_sched_nr_migrate = 32; | |
293 | ||
e9e9250b PZ |
294 | /* |
295 | * period over which we average the RT time consumption, measured | |
296 | * in ms. | |
297 | * | |
298 | * default: 1s | |
299 | */ | |
300 | const_debug unsigned int sysctl_sched_time_avg = MSEC_PER_SEC; | |
301 | ||
fa85ae24 | 302 | /* |
9f0c1e56 | 303 | * period over which we measure -rt task cpu usage in us. |
fa85ae24 PZ |
304 | * default: 1s |
305 | */ | |
9f0c1e56 | 306 | unsigned int sysctl_sched_rt_period = 1000000; |
fa85ae24 | 307 | |
029632fb | 308 | __read_mostly int scheduler_running; |
6892b75e | 309 | |
9f0c1e56 PZ |
310 | /* |
311 | * part of the period that we allow rt tasks to run in us. | |
312 | * default: 0.95s | |
313 | */ | |
314 | int sysctl_sched_rt_runtime = 950000; | |
fa85ae24 | 315 | |
0970d299 | 316 | /* |
0122ec5b | 317 | * __task_rq_lock - lock the rq @p resides on. |
b29739f9 | 318 | */ |
70b97a7f | 319 | static inline struct rq *__task_rq_lock(struct task_struct *p) |
b29739f9 IM |
320 | __acquires(rq->lock) |
321 | { | |
0970d299 PZ |
322 | struct rq *rq; |
323 | ||
0122ec5b PZ |
324 | lockdep_assert_held(&p->pi_lock); |
325 | ||
3a5c359a | 326 | for (;;) { |
0970d299 | 327 | rq = task_rq(p); |
05fa785c | 328 | raw_spin_lock(&rq->lock); |
65cc8e48 | 329 | if (likely(rq == task_rq(p))) |
3a5c359a | 330 | return rq; |
05fa785c | 331 | raw_spin_unlock(&rq->lock); |
b29739f9 | 332 | } |
b29739f9 IM |
333 | } |
334 | ||
1da177e4 | 335 | /* |
0122ec5b | 336 | * task_rq_lock - lock p->pi_lock and lock the rq @p resides on. |
1da177e4 | 337 | */ |
70b97a7f | 338 | static struct rq *task_rq_lock(struct task_struct *p, unsigned long *flags) |
0122ec5b | 339 | __acquires(p->pi_lock) |
1da177e4 LT |
340 | __acquires(rq->lock) |
341 | { | |
70b97a7f | 342 | struct rq *rq; |
1da177e4 | 343 | |
3a5c359a | 344 | for (;;) { |
0122ec5b | 345 | raw_spin_lock_irqsave(&p->pi_lock, *flags); |
3a5c359a | 346 | rq = task_rq(p); |
05fa785c | 347 | raw_spin_lock(&rq->lock); |
65cc8e48 | 348 | if (likely(rq == task_rq(p))) |
3a5c359a | 349 | return rq; |
0122ec5b PZ |
350 | raw_spin_unlock(&rq->lock); |
351 | raw_spin_unlock_irqrestore(&p->pi_lock, *flags); | |
1da177e4 | 352 | } |
1da177e4 LT |
353 | } |
354 | ||
a9957449 | 355 | static void __task_rq_unlock(struct rq *rq) |
b29739f9 IM |
356 | __releases(rq->lock) |
357 | { | |
05fa785c | 358 | raw_spin_unlock(&rq->lock); |
b29739f9 IM |
359 | } |
360 | ||
0122ec5b PZ |
361 | static inline void |
362 | task_rq_unlock(struct rq *rq, struct task_struct *p, unsigned long *flags) | |
1da177e4 | 363 | __releases(rq->lock) |
0122ec5b | 364 | __releases(p->pi_lock) |
1da177e4 | 365 | { |
0122ec5b PZ |
366 | raw_spin_unlock(&rq->lock); |
367 | raw_spin_unlock_irqrestore(&p->pi_lock, *flags); | |
1da177e4 LT |
368 | } |
369 | ||
1da177e4 | 370 | /* |
cc2a73b5 | 371 | * this_rq_lock - lock this runqueue and disable interrupts. |
1da177e4 | 372 | */ |
a9957449 | 373 | static struct rq *this_rq_lock(void) |
1da177e4 LT |
374 | __acquires(rq->lock) |
375 | { | |
70b97a7f | 376 | struct rq *rq; |
1da177e4 LT |
377 | |
378 | local_irq_disable(); | |
379 | rq = this_rq(); | |
05fa785c | 380 | raw_spin_lock(&rq->lock); |
1da177e4 LT |
381 | |
382 | return rq; | |
383 | } | |
384 | ||
8f4d37ec PZ |
385 | #ifdef CONFIG_SCHED_HRTICK |
386 | /* | |
387 | * Use HR-timers to deliver accurate preemption points. | |
8f4d37ec | 388 | */ |
8f4d37ec | 389 | |
8f4d37ec PZ |
390 | static void hrtick_clear(struct rq *rq) |
391 | { | |
392 | if (hrtimer_active(&rq->hrtick_timer)) | |
393 | hrtimer_cancel(&rq->hrtick_timer); | |
394 | } | |
395 | ||
8f4d37ec PZ |
396 | /* |
397 | * High-resolution timer tick. | |
398 | * Runs from hardirq context with interrupts disabled. | |
399 | */ | |
400 | static enum hrtimer_restart hrtick(struct hrtimer *timer) | |
401 | { | |
402 | struct rq *rq = container_of(timer, struct rq, hrtick_timer); | |
403 | ||
404 | WARN_ON_ONCE(cpu_of(rq) != smp_processor_id()); | |
405 | ||
05fa785c | 406 | raw_spin_lock(&rq->lock); |
3e51f33f | 407 | update_rq_clock(rq); |
8f4d37ec | 408 | rq->curr->sched_class->task_tick(rq, rq->curr, 1); |
05fa785c | 409 | raw_spin_unlock(&rq->lock); |
8f4d37ec PZ |
410 | |
411 | return HRTIMER_NORESTART; | |
412 | } | |
413 | ||
95e904c7 | 414 | #ifdef CONFIG_SMP |
971ee28c PZ |
415 | |
416 | static int __hrtick_restart(struct rq *rq) | |
417 | { | |
418 | struct hrtimer *timer = &rq->hrtick_timer; | |
419 | ktime_t time = hrtimer_get_softexpires(timer); | |
420 | ||
421 | return __hrtimer_start_range_ns(timer, time, 0, HRTIMER_MODE_ABS_PINNED, 0); | |
422 | } | |
423 | ||
31656519 PZ |
424 | /* |
425 | * called from hardirq (IPI) context | |
426 | */ | |
427 | static void __hrtick_start(void *arg) | |
b328ca18 | 428 | { |
31656519 | 429 | struct rq *rq = arg; |
b328ca18 | 430 | |
05fa785c | 431 | raw_spin_lock(&rq->lock); |
971ee28c | 432 | __hrtick_restart(rq); |
31656519 | 433 | rq->hrtick_csd_pending = 0; |
05fa785c | 434 | raw_spin_unlock(&rq->lock); |
b328ca18 PZ |
435 | } |
436 | ||
31656519 PZ |
437 | /* |
438 | * Called to set the hrtick timer state. | |
439 | * | |
440 | * called with rq->lock held and irqs disabled | |
441 | */ | |
029632fb | 442 | void hrtick_start(struct rq *rq, u64 delay) |
b328ca18 | 443 | { |
31656519 PZ |
444 | struct hrtimer *timer = &rq->hrtick_timer; |
445 | ktime_t time = ktime_add_ns(timer->base->get_time(), delay); | |
b328ca18 | 446 | |
cc584b21 | 447 | hrtimer_set_expires(timer, time); |
31656519 PZ |
448 | |
449 | if (rq == this_rq()) { | |
971ee28c | 450 | __hrtick_restart(rq); |
31656519 | 451 | } else if (!rq->hrtick_csd_pending) { |
c46fff2a | 452 | smp_call_function_single_async(cpu_of(rq), &rq->hrtick_csd); |
31656519 PZ |
453 | rq->hrtick_csd_pending = 1; |
454 | } | |
b328ca18 PZ |
455 | } |
456 | ||
457 | static int | |
458 | hotplug_hrtick(struct notifier_block *nfb, unsigned long action, void *hcpu) | |
459 | { | |
460 | int cpu = (int)(long)hcpu; | |
461 | ||
462 | switch (action) { | |
463 | case CPU_UP_CANCELED: | |
464 | case CPU_UP_CANCELED_FROZEN: | |
465 | case CPU_DOWN_PREPARE: | |
466 | case CPU_DOWN_PREPARE_FROZEN: | |
467 | case CPU_DEAD: | |
468 | case CPU_DEAD_FROZEN: | |
31656519 | 469 | hrtick_clear(cpu_rq(cpu)); |
b328ca18 PZ |
470 | return NOTIFY_OK; |
471 | } | |
472 | ||
473 | return NOTIFY_DONE; | |
474 | } | |
475 | ||
fa748203 | 476 | static __init void init_hrtick(void) |
b328ca18 PZ |
477 | { |
478 | hotcpu_notifier(hotplug_hrtick, 0); | |
479 | } | |
31656519 PZ |
480 | #else |
481 | /* | |
482 | * Called to set the hrtick timer state. | |
483 | * | |
484 | * called with rq->lock held and irqs disabled | |
485 | */ | |
029632fb | 486 | void hrtick_start(struct rq *rq, u64 delay) |
31656519 | 487 | { |
7f1e2ca9 | 488 | __hrtimer_start_range_ns(&rq->hrtick_timer, ns_to_ktime(delay), 0, |
5c333864 | 489 | HRTIMER_MODE_REL_PINNED, 0); |
31656519 | 490 | } |
b328ca18 | 491 | |
006c75f1 | 492 | static inline void init_hrtick(void) |
8f4d37ec | 493 | { |
8f4d37ec | 494 | } |
31656519 | 495 | #endif /* CONFIG_SMP */ |
8f4d37ec | 496 | |
31656519 | 497 | static void init_rq_hrtick(struct rq *rq) |
8f4d37ec | 498 | { |
31656519 PZ |
499 | #ifdef CONFIG_SMP |
500 | rq->hrtick_csd_pending = 0; | |
8f4d37ec | 501 | |
31656519 PZ |
502 | rq->hrtick_csd.flags = 0; |
503 | rq->hrtick_csd.func = __hrtick_start; | |
504 | rq->hrtick_csd.info = rq; | |
505 | #endif | |
8f4d37ec | 506 | |
31656519 PZ |
507 | hrtimer_init(&rq->hrtick_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); |
508 | rq->hrtick_timer.function = hrtick; | |
8f4d37ec | 509 | } |
006c75f1 | 510 | #else /* CONFIG_SCHED_HRTICK */ |
8f4d37ec PZ |
511 | static inline void hrtick_clear(struct rq *rq) |
512 | { | |
513 | } | |
514 | ||
8f4d37ec PZ |
515 | static inline void init_rq_hrtick(struct rq *rq) |
516 | { | |
517 | } | |
518 | ||
b328ca18 PZ |
519 | static inline void init_hrtick(void) |
520 | { | |
521 | } | |
006c75f1 | 522 | #endif /* CONFIG_SCHED_HRTICK */ |
8f4d37ec | 523 | |
fd99f91a PZ |
524 | /* |
525 | * cmpxchg based fetch_or, macro so it works for different integer types | |
526 | */ | |
527 | #define fetch_or(ptr, val) \ | |
528 | ({ typeof(*(ptr)) __old, __val = *(ptr); \ | |
529 | for (;;) { \ | |
530 | __old = cmpxchg((ptr), __val, __val | (val)); \ | |
531 | if (__old == __val) \ | |
532 | break; \ | |
533 | __val = __old; \ | |
534 | } \ | |
535 | __old; \ | |
536 | }) | |
537 | ||
e3baac47 | 538 | #if defined(CONFIG_SMP) && defined(TIF_POLLING_NRFLAG) |
fd99f91a PZ |
539 | /* |
540 | * Atomically set TIF_NEED_RESCHED and test for TIF_POLLING_NRFLAG, | |
541 | * this avoids any races wrt polling state changes and thereby avoids | |
542 | * spurious IPIs. | |
543 | */ | |
544 | static bool set_nr_and_not_polling(struct task_struct *p) | |
545 | { | |
546 | struct thread_info *ti = task_thread_info(p); | |
547 | return !(fetch_or(&ti->flags, _TIF_NEED_RESCHED) & _TIF_POLLING_NRFLAG); | |
548 | } | |
e3baac47 PZ |
549 | |
550 | /* | |
551 | * Atomically set TIF_NEED_RESCHED if TIF_POLLING_NRFLAG is set. | |
552 | * | |
553 | * If this returns true, then the idle task promises to call | |
554 | * sched_ttwu_pending() and reschedule soon. | |
555 | */ | |
556 | static bool set_nr_if_polling(struct task_struct *p) | |
557 | { | |
558 | struct thread_info *ti = task_thread_info(p); | |
559 | typeof(ti->flags) old, val = ACCESS_ONCE(ti->flags); | |
560 | ||
561 | for (;;) { | |
562 | if (!(val & _TIF_POLLING_NRFLAG)) | |
563 | return false; | |
564 | if (val & _TIF_NEED_RESCHED) | |
565 | return true; | |
566 | old = cmpxchg(&ti->flags, val, val | _TIF_NEED_RESCHED); | |
567 | if (old == val) | |
568 | break; | |
569 | val = old; | |
570 | } | |
571 | return true; | |
572 | } | |
573 | ||
fd99f91a PZ |
574 | #else |
575 | static bool set_nr_and_not_polling(struct task_struct *p) | |
576 | { | |
577 | set_tsk_need_resched(p); | |
578 | return true; | |
579 | } | |
e3baac47 PZ |
580 | |
581 | #ifdef CONFIG_SMP | |
582 | static bool set_nr_if_polling(struct task_struct *p) | |
583 | { | |
584 | return false; | |
585 | } | |
586 | #endif | |
fd99f91a PZ |
587 | #endif |
588 | ||
c24d20db IM |
589 | /* |
590 | * resched_task - mark a task 'to be rescheduled now'. | |
591 | * | |
592 | * On UP this means the setting of the need_resched flag, on SMP it | |
593 | * might also involve a cross-CPU call to trigger the scheduler on | |
594 | * the target CPU. | |
595 | */ | |
029632fb | 596 | void resched_task(struct task_struct *p) |
c24d20db IM |
597 | { |
598 | int cpu; | |
599 | ||
b021fe3e | 600 | lockdep_assert_held(&task_rq(p)->lock); |
c24d20db | 601 | |
5ed0cec0 | 602 | if (test_tsk_need_resched(p)) |
c24d20db IM |
603 | return; |
604 | ||
c24d20db | 605 | cpu = task_cpu(p); |
fd99f91a | 606 | |
f27dde8d | 607 | if (cpu == smp_processor_id()) { |
fd99f91a | 608 | set_tsk_need_resched(p); |
f27dde8d | 609 | set_preempt_need_resched(); |
c24d20db | 610 | return; |
f27dde8d | 611 | } |
c24d20db | 612 | |
fd99f91a | 613 | if (set_nr_and_not_polling(p)) |
c24d20db | 614 | smp_send_reschedule(cpu); |
dfc68f29 AL |
615 | else |
616 | trace_sched_wake_idle_without_ipi(cpu); | |
c24d20db IM |
617 | } |
618 | ||
029632fb | 619 | void resched_cpu(int cpu) |
c24d20db IM |
620 | { |
621 | struct rq *rq = cpu_rq(cpu); | |
622 | unsigned long flags; | |
623 | ||
05fa785c | 624 | if (!raw_spin_trylock_irqsave(&rq->lock, flags)) |
c24d20db IM |
625 | return; |
626 | resched_task(cpu_curr(cpu)); | |
05fa785c | 627 | raw_spin_unlock_irqrestore(&rq->lock, flags); |
c24d20db | 628 | } |
06d8308c | 629 | |
b021fe3e | 630 | #ifdef CONFIG_SMP |
3451d024 | 631 | #ifdef CONFIG_NO_HZ_COMMON |
83cd4fe2 VP |
632 | /* |
633 | * In the semi idle case, use the nearest busy cpu for migrating timers | |
634 | * from an idle cpu. This is good for power-savings. | |
635 | * | |
636 | * We don't do similar optimization for completely idle system, as | |
637 | * selecting an idle cpu will add more delays to the timers than intended | |
638 | * (as that cpu's timer base may not be uptodate wrt jiffies etc). | |
639 | */ | |
6201b4d6 | 640 | int get_nohz_timer_target(int pinned) |
83cd4fe2 VP |
641 | { |
642 | int cpu = smp_processor_id(); | |
643 | int i; | |
644 | struct sched_domain *sd; | |
645 | ||
6201b4d6 VK |
646 | if (pinned || !get_sysctl_timer_migration() || !idle_cpu(cpu)) |
647 | return cpu; | |
648 | ||
057f3fad | 649 | rcu_read_lock(); |
83cd4fe2 | 650 | for_each_domain(cpu, sd) { |
057f3fad PZ |
651 | for_each_cpu(i, sched_domain_span(sd)) { |
652 | if (!idle_cpu(i)) { | |
653 | cpu = i; | |
654 | goto unlock; | |
655 | } | |
656 | } | |
83cd4fe2 | 657 | } |
057f3fad PZ |
658 | unlock: |
659 | rcu_read_unlock(); | |
83cd4fe2 VP |
660 | return cpu; |
661 | } | |
06d8308c TG |
662 | /* |
663 | * When add_timer_on() enqueues a timer into the timer wheel of an | |
664 | * idle CPU then this timer might expire before the next timer event | |
665 | * which is scheduled to wake up that CPU. In case of a completely | |
666 | * idle system the next event might even be infinite time into the | |
667 | * future. wake_up_idle_cpu() ensures that the CPU is woken up and | |
668 | * leaves the inner idle loop so the newly added timer is taken into | |
669 | * account when the CPU goes back to idle and evaluates the timer | |
670 | * wheel for the next timer event. | |
671 | */ | |
1c20091e | 672 | static void wake_up_idle_cpu(int cpu) |
06d8308c TG |
673 | { |
674 | struct rq *rq = cpu_rq(cpu); | |
675 | ||
676 | if (cpu == smp_processor_id()) | |
677 | return; | |
678 | ||
67b9ca70 | 679 | if (set_nr_and_not_polling(rq->idle)) |
06d8308c | 680 | smp_send_reschedule(cpu); |
dfc68f29 AL |
681 | else |
682 | trace_sched_wake_idle_without_ipi(cpu); | |
45bf76df IM |
683 | } |
684 | ||
c5bfece2 | 685 | static bool wake_up_full_nohz_cpu(int cpu) |
1c20091e | 686 | { |
c5bfece2 | 687 | if (tick_nohz_full_cpu(cpu)) { |
1c20091e FW |
688 | if (cpu != smp_processor_id() || |
689 | tick_nohz_tick_stopped()) | |
690 | smp_send_reschedule(cpu); | |
691 | return true; | |
692 | } | |
693 | ||
694 | return false; | |
695 | } | |
696 | ||
697 | void wake_up_nohz_cpu(int cpu) | |
698 | { | |
c5bfece2 | 699 | if (!wake_up_full_nohz_cpu(cpu)) |
1c20091e FW |
700 | wake_up_idle_cpu(cpu); |
701 | } | |
702 | ||
ca38062e | 703 | static inline bool got_nohz_idle_kick(void) |
45bf76df | 704 | { |
1c792db7 | 705 | int cpu = smp_processor_id(); |
873b4c65 VG |
706 | |
707 | if (!test_bit(NOHZ_BALANCE_KICK, nohz_flags(cpu))) | |
708 | return false; | |
709 | ||
710 | if (idle_cpu(cpu) && !need_resched()) | |
711 | return true; | |
712 | ||
713 | /* | |
714 | * We can't run Idle Load Balance on this CPU for this time so we | |
715 | * cancel it and clear NOHZ_BALANCE_KICK | |
716 | */ | |
717 | clear_bit(NOHZ_BALANCE_KICK, nohz_flags(cpu)); | |
718 | return false; | |
45bf76df IM |
719 | } |
720 | ||
3451d024 | 721 | #else /* CONFIG_NO_HZ_COMMON */ |
45bf76df | 722 | |
ca38062e | 723 | static inline bool got_nohz_idle_kick(void) |
2069dd75 | 724 | { |
ca38062e | 725 | return false; |
2069dd75 PZ |
726 | } |
727 | ||
3451d024 | 728 | #endif /* CONFIG_NO_HZ_COMMON */ |
d842de87 | 729 | |
ce831b38 FW |
730 | #ifdef CONFIG_NO_HZ_FULL |
731 | bool sched_can_stop_tick(void) | |
732 | { | |
733 | struct rq *rq; | |
734 | ||
735 | rq = this_rq(); | |
736 | ||
737 | /* Make sure rq->nr_running update is visible after the IPI */ | |
738 | smp_rmb(); | |
739 | ||
740 | /* More than one running task need preemption */ | |
741 | if (rq->nr_running > 1) | |
742 | return false; | |
743 | ||
744 | return true; | |
745 | } | |
746 | #endif /* CONFIG_NO_HZ_FULL */ | |
d842de87 | 747 | |
029632fb | 748 | void sched_avg_update(struct rq *rq) |
18d95a28 | 749 | { |
e9e9250b PZ |
750 | s64 period = sched_avg_period(); |
751 | ||
78becc27 | 752 | while ((s64)(rq_clock(rq) - rq->age_stamp) > period) { |
0d98bb26 WD |
753 | /* |
754 | * Inline assembly required to prevent the compiler | |
755 | * optimising this loop into a divmod call. | |
756 | * See __iter_div_u64_rem() for another example of this. | |
757 | */ | |
758 | asm("" : "+rm" (rq->age_stamp)); | |
e9e9250b PZ |
759 | rq->age_stamp += period; |
760 | rq->rt_avg /= 2; | |
761 | } | |
18d95a28 PZ |
762 | } |
763 | ||
6d6bc0ad | 764 | #endif /* CONFIG_SMP */ |
18d95a28 | 765 | |
a790de99 PT |
766 | #if defined(CONFIG_RT_GROUP_SCHED) || (defined(CONFIG_FAIR_GROUP_SCHED) && \ |
767 | (defined(CONFIG_SMP) || defined(CONFIG_CFS_BANDWIDTH))) | |
c09595f6 | 768 | /* |
8277434e PT |
769 | * Iterate task_group tree rooted at *from, calling @down when first entering a |
770 | * node and @up when leaving it for the final time. | |
771 | * | |
772 | * Caller must hold rcu_lock or sufficient equivalent. | |
c09595f6 | 773 | */ |
029632fb | 774 | int walk_tg_tree_from(struct task_group *from, |
8277434e | 775 | tg_visitor down, tg_visitor up, void *data) |
c09595f6 PZ |
776 | { |
777 | struct task_group *parent, *child; | |
eb755805 | 778 | int ret; |
c09595f6 | 779 | |
8277434e PT |
780 | parent = from; |
781 | ||
c09595f6 | 782 | down: |
eb755805 PZ |
783 | ret = (*down)(parent, data); |
784 | if (ret) | |
8277434e | 785 | goto out; |
c09595f6 PZ |
786 | list_for_each_entry_rcu(child, &parent->children, siblings) { |
787 | parent = child; | |
788 | goto down; | |
789 | ||
790 | up: | |
791 | continue; | |
792 | } | |
eb755805 | 793 | ret = (*up)(parent, data); |
8277434e PT |
794 | if (ret || parent == from) |
795 | goto out; | |
c09595f6 PZ |
796 | |
797 | child = parent; | |
798 | parent = parent->parent; | |
799 | if (parent) | |
800 | goto up; | |
8277434e | 801 | out: |
eb755805 | 802 | return ret; |
c09595f6 PZ |
803 | } |
804 | ||
029632fb | 805 | int tg_nop(struct task_group *tg, void *data) |
eb755805 | 806 | { |
e2b245f8 | 807 | return 0; |
eb755805 | 808 | } |
18d95a28 PZ |
809 | #endif |
810 | ||
45bf76df IM |
811 | static void set_load_weight(struct task_struct *p) |
812 | { | |
f05998d4 NR |
813 | int prio = p->static_prio - MAX_RT_PRIO; |
814 | struct load_weight *load = &p->se.load; | |
815 | ||
dd41f596 IM |
816 | /* |
817 | * SCHED_IDLE tasks get minimal weight: | |
818 | */ | |
819 | if (p->policy == SCHED_IDLE) { | |
c8b28116 | 820 | load->weight = scale_load(WEIGHT_IDLEPRIO); |
f05998d4 | 821 | load->inv_weight = WMULT_IDLEPRIO; |
dd41f596 IM |
822 | return; |
823 | } | |
71f8bd46 | 824 | |
c8b28116 | 825 | load->weight = scale_load(prio_to_weight[prio]); |
f05998d4 | 826 | load->inv_weight = prio_to_wmult[prio]; |
71f8bd46 IM |
827 | } |
828 | ||
371fd7e7 | 829 | static void enqueue_task(struct rq *rq, struct task_struct *p, int flags) |
2087a1ad | 830 | { |
a64692a3 | 831 | update_rq_clock(rq); |
43148951 | 832 | sched_info_queued(rq, p); |
371fd7e7 | 833 | p->sched_class->enqueue_task(rq, p, flags); |
71f8bd46 IM |
834 | } |
835 | ||
371fd7e7 | 836 | static void dequeue_task(struct rq *rq, struct task_struct *p, int flags) |
71f8bd46 | 837 | { |
a64692a3 | 838 | update_rq_clock(rq); |
43148951 | 839 | sched_info_dequeued(rq, p); |
371fd7e7 | 840 | p->sched_class->dequeue_task(rq, p, flags); |
71f8bd46 IM |
841 | } |
842 | ||
029632fb | 843 | void activate_task(struct rq *rq, struct task_struct *p, int flags) |
1e3c88bd PZ |
844 | { |
845 | if (task_contributes_to_load(p)) | |
846 | rq->nr_uninterruptible--; | |
847 | ||
371fd7e7 | 848 | enqueue_task(rq, p, flags); |
1e3c88bd PZ |
849 | } |
850 | ||
029632fb | 851 | void deactivate_task(struct rq *rq, struct task_struct *p, int flags) |
1e3c88bd PZ |
852 | { |
853 | if (task_contributes_to_load(p)) | |
854 | rq->nr_uninterruptible++; | |
855 | ||
371fd7e7 | 856 | dequeue_task(rq, p, flags); |
1e3c88bd PZ |
857 | } |
858 | ||
fe44d621 | 859 | static void update_rq_clock_task(struct rq *rq, s64 delta) |
aa483808 | 860 | { |
095c0aa8 GC |
861 | /* |
862 | * In theory, the compile should just see 0 here, and optimize out the call | |
863 | * to sched_rt_avg_update. But I don't trust it... | |
864 | */ | |
865 | #if defined(CONFIG_IRQ_TIME_ACCOUNTING) || defined(CONFIG_PARAVIRT_TIME_ACCOUNTING) | |
866 | s64 steal = 0, irq_delta = 0; | |
867 | #endif | |
868 | #ifdef CONFIG_IRQ_TIME_ACCOUNTING | |
8e92c201 | 869 | irq_delta = irq_time_read(cpu_of(rq)) - rq->prev_irq_time; |
fe44d621 PZ |
870 | |
871 | /* | |
872 | * Since irq_time is only updated on {soft,}irq_exit, we might run into | |
873 | * this case when a previous update_rq_clock() happened inside a | |
874 | * {soft,}irq region. | |
875 | * | |
876 | * When this happens, we stop ->clock_task and only update the | |
877 | * prev_irq_time stamp to account for the part that fit, so that a next | |
878 | * update will consume the rest. This ensures ->clock_task is | |
879 | * monotonic. | |
880 | * | |
881 | * It does however cause some slight miss-attribution of {soft,}irq | |
882 | * time, a more accurate solution would be to update the irq_time using | |
883 | * the current rq->clock timestamp, except that would require using | |
884 | * atomic ops. | |
885 | */ | |
886 | if (irq_delta > delta) | |
887 | irq_delta = delta; | |
888 | ||
889 | rq->prev_irq_time += irq_delta; | |
890 | delta -= irq_delta; | |
095c0aa8 GC |
891 | #endif |
892 | #ifdef CONFIG_PARAVIRT_TIME_ACCOUNTING | |
c5905afb | 893 | if (static_key_false((¶virt_steal_rq_enabled))) { |
095c0aa8 GC |
894 | steal = paravirt_steal_clock(cpu_of(rq)); |
895 | steal -= rq->prev_steal_time_rq; | |
896 | ||
897 | if (unlikely(steal > delta)) | |
898 | steal = delta; | |
899 | ||
095c0aa8 | 900 | rq->prev_steal_time_rq += steal; |
095c0aa8 GC |
901 | delta -= steal; |
902 | } | |
903 | #endif | |
904 | ||
fe44d621 PZ |
905 | rq->clock_task += delta; |
906 | ||
095c0aa8 | 907 | #if defined(CONFIG_IRQ_TIME_ACCOUNTING) || defined(CONFIG_PARAVIRT_TIME_ACCOUNTING) |
5d4dfddd | 908 | if ((irq_delta + steal) && sched_feat(NONTASK_CAPACITY)) |
095c0aa8 GC |
909 | sched_rt_avg_update(rq, irq_delta + steal); |
910 | #endif | |
aa483808 VP |
911 | } |
912 | ||
34f971f6 PZ |
913 | void sched_set_stop_task(int cpu, struct task_struct *stop) |
914 | { | |
915 | struct sched_param param = { .sched_priority = MAX_RT_PRIO - 1 }; | |
916 | struct task_struct *old_stop = cpu_rq(cpu)->stop; | |
917 | ||
918 | if (stop) { | |
919 | /* | |
920 | * Make it appear like a SCHED_FIFO task, its something | |
921 | * userspace knows about and won't get confused about. | |
922 | * | |
923 | * Also, it will make PI more or less work without too | |
924 | * much confusion -- but then, stop work should not | |
925 | * rely on PI working anyway. | |
926 | */ | |
927 | sched_setscheduler_nocheck(stop, SCHED_FIFO, ¶m); | |
928 | ||
929 | stop->sched_class = &stop_sched_class; | |
930 | } | |
931 | ||
932 | cpu_rq(cpu)->stop = stop; | |
933 | ||
934 | if (old_stop) { | |
935 | /* | |
936 | * Reset it back to a normal scheduling class so that | |
937 | * it can die in pieces. | |
938 | */ | |
939 | old_stop->sched_class = &rt_sched_class; | |
940 | } | |
941 | } | |
942 | ||
14531189 | 943 | /* |
dd41f596 | 944 | * __normal_prio - return the priority that is based on the static prio |
14531189 | 945 | */ |
14531189 IM |
946 | static inline int __normal_prio(struct task_struct *p) |
947 | { | |
dd41f596 | 948 | return p->static_prio; |
14531189 IM |
949 | } |
950 | ||
b29739f9 IM |
951 | /* |
952 | * Calculate the expected normal priority: i.e. priority | |
953 | * without taking RT-inheritance into account. Might be | |
954 | * boosted by interactivity modifiers. Changes upon fork, | |
955 | * setprio syscalls, and whenever the interactivity | |
956 | * estimator recalculates. | |
957 | */ | |
36c8b586 | 958 | static inline int normal_prio(struct task_struct *p) |
b29739f9 IM |
959 | { |
960 | int prio; | |
961 | ||
aab03e05 DF |
962 | if (task_has_dl_policy(p)) |
963 | prio = MAX_DL_PRIO-1; | |
964 | else if (task_has_rt_policy(p)) | |
b29739f9 IM |
965 | prio = MAX_RT_PRIO-1 - p->rt_priority; |
966 | else | |
967 | prio = __normal_prio(p); | |
968 | return prio; | |
969 | } | |
970 | ||
971 | /* | |
972 | * Calculate the current priority, i.e. the priority | |
973 | * taken into account by the scheduler. This value might | |
974 | * be boosted by RT tasks, or might be boosted by | |
975 | * interactivity modifiers. Will be RT if the task got | |
976 | * RT-boosted. If not then it returns p->normal_prio. | |
977 | */ | |
36c8b586 | 978 | static int effective_prio(struct task_struct *p) |
b29739f9 IM |
979 | { |
980 | p->normal_prio = normal_prio(p); | |
981 | /* | |
982 | * If we are RT tasks or we were boosted to RT priority, | |
983 | * keep the priority unchanged. Otherwise, update priority | |
984 | * to the normal priority: | |
985 | */ | |
986 | if (!rt_prio(p->prio)) | |
987 | return p->normal_prio; | |
988 | return p->prio; | |
989 | } | |
990 | ||
1da177e4 LT |
991 | /** |
992 | * task_curr - is this task currently executing on a CPU? | |
993 | * @p: the task in question. | |
e69f6186 YB |
994 | * |
995 | * Return: 1 if the task is currently executing. 0 otherwise. | |
1da177e4 | 996 | */ |
36c8b586 | 997 | inline int task_curr(const struct task_struct *p) |
1da177e4 LT |
998 | { |
999 | return cpu_curr(task_cpu(p)) == p; | |
1000 | } | |
1001 | ||
cb469845 SR |
1002 | static inline void check_class_changed(struct rq *rq, struct task_struct *p, |
1003 | const struct sched_class *prev_class, | |
da7a735e | 1004 | int oldprio) |
cb469845 SR |
1005 | { |
1006 | if (prev_class != p->sched_class) { | |
1007 | if (prev_class->switched_from) | |
da7a735e PZ |
1008 | prev_class->switched_from(rq, p); |
1009 | p->sched_class->switched_to(rq, p); | |
2d3d891d | 1010 | } else if (oldprio != p->prio || dl_task(p)) |
da7a735e | 1011 | p->sched_class->prio_changed(rq, p, oldprio); |
cb469845 SR |
1012 | } |
1013 | ||
029632fb | 1014 | void check_preempt_curr(struct rq *rq, struct task_struct *p, int flags) |
1e5a7405 PZ |
1015 | { |
1016 | const struct sched_class *class; | |
1017 | ||
1018 | if (p->sched_class == rq->curr->sched_class) { | |
1019 | rq->curr->sched_class->check_preempt_curr(rq, p, flags); | |
1020 | } else { | |
1021 | for_each_class(class) { | |
1022 | if (class == rq->curr->sched_class) | |
1023 | break; | |
1024 | if (class == p->sched_class) { | |
1025 | resched_task(rq->curr); | |
1026 | break; | |
1027 | } | |
1028 | } | |
1029 | } | |
1030 | ||
1031 | /* | |
1032 | * A queue event has occurred, and we're going to schedule. In | |
1033 | * this case, we can save a useless back to back clock update. | |
1034 | */ | |
fd2f4419 | 1035 | if (rq->curr->on_rq && test_tsk_need_resched(rq->curr)) |
1e5a7405 PZ |
1036 | rq->skip_clock_update = 1; |
1037 | } | |
1038 | ||
1da177e4 | 1039 | #ifdef CONFIG_SMP |
dd41f596 | 1040 | void set_task_cpu(struct task_struct *p, unsigned int new_cpu) |
c65cc870 | 1041 | { |
e2912009 PZ |
1042 | #ifdef CONFIG_SCHED_DEBUG |
1043 | /* | |
1044 | * We should never call set_task_cpu() on a blocked task, | |
1045 | * ttwu() will sort out the placement. | |
1046 | */ | |
077614ee | 1047 | WARN_ON_ONCE(p->state != TASK_RUNNING && p->state != TASK_WAKING && |
01028747 | 1048 | !(task_preempt_count(p) & PREEMPT_ACTIVE)); |
0122ec5b PZ |
1049 | |
1050 | #ifdef CONFIG_LOCKDEP | |
6c6c54e1 PZ |
1051 | /* |
1052 | * The caller should hold either p->pi_lock or rq->lock, when changing | |
1053 | * a task's CPU. ->pi_lock for waking tasks, rq->lock for runnable tasks. | |
1054 | * | |
1055 | * sched_move_task() holds both and thus holding either pins the cgroup, | |
8323f26c | 1056 | * see task_group(). |
6c6c54e1 PZ |
1057 | * |
1058 | * Furthermore, all task_rq users should acquire both locks, see | |
1059 | * task_rq_lock(). | |
1060 | */ | |
0122ec5b PZ |
1061 | WARN_ON_ONCE(debug_locks && !(lockdep_is_held(&p->pi_lock) || |
1062 | lockdep_is_held(&task_rq(p)->lock))); | |
1063 | #endif | |
e2912009 PZ |
1064 | #endif |
1065 | ||
de1d7286 | 1066 | trace_sched_migrate_task(p, new_cpu); |
cbc34ed1 | 1067 | |
0c69774e | 1068 | if (task_cpu(p) != new_cpu) { |
0a74bef8 PT |
1069 | if (p->sched_class->migrate_task_rq) |
1070 | p->sched_class->migrate_task_rq(p, new_cpu); | |
0c69774e | 1071 | p->se.nr_migrations++; |
a8b0ca17 | 1072 | perf_sw_event(PERF_COUNT_SW_CPU_MIGRATIONS, 1, NULL, 0); |
0c69774e | 1073 | } |
dd41f596 IM |
1074 | |
1075 | __set_task_cpu(p, new_cpu); | |
c65cc870 IM |
1076 | } |
1077 | ||
ac66f547 PZ |
1078 | static void __migrate_swap_task(struct task_struct *p, int cpu) |
1079 | { | |
1080 | if (p->on_rq) { | |
1081 | struct rq *src_rq, *dst_rq; | |
1082 | ||
1083 | src_rq = task_rq(p); | |
1084 | dst_rq = cpu_rq(cpu); | |
1085 | ||
1086 | deactivate_task(src_rq, p, 0); | |
1087 | set_task_cpu(p, cpu); | |
1088 | activate_task(dst_rq, p, 0); | |
1089 | check_preempt_curr(dst_rq, p, 0); | |
1090 | } else { | |
1091 | /* | |
1092 | * Task isn't running anymore; make it appear like we migrated | |
1093 | * it before it went to sleep. This means on wakeup we make the | |
1094 | * previous cpu our targer instead of where it really is. | |
1095 | */ | |
1096 | p->wake_cpu = cpu; | |
1097 | } | |
1098 | } | |
1099 | ||
1100 | struct migration_swap_arg { | |
1101 | struct task_struct *src_task, *dst_task; | |
1102 | int src_cpu, dst_cpu; | |
1103 | }; | |
1104 | ||
1105 | static int migrate_swap_stop(void *data) | |
1106 | { | |
1107 | struct migration_swap_arg *arg = data; | |
1108 | struct rq *src_rq, *dst_rq; | |
1109 | int ret = -EAGAIN; | |
1110 | ||
1111 | src_rq = cpu_rq(arg->src_cpu); | |
1112 | dst_rq = cpu_rq(arg->dst_cpu); | |
1113 | ||
74602315 PZ |
1114 | double_raw_lock(&arg->src_task->pi_lock, |
1115 | &arg->dst_task->pi_lock); | |
ac66f547 PZ |
1116 | double_rq_lock(src_rq, dst_rq); |
1117 | if (task_cpu(arg->dst_task) != arg->dst_cpu) | |
1118 | goto unlock; | |
1119 | ||
1120 | if (task_cpu(arg->src_task) != arg->src_cpu) | |
1121 | goto unlock; | |
1122 | ||
1123 | if (!cpumask_test_cpu(arg->dst_cpu, tsk_cpus_allowed(arg->src_task))) | |
1124 | goto unlock; | |
1125 | ||
1126 | if (!cpumask_test_cpu(arg->src_cpu, tsk_cpus_allowed(arg->dst_task))) | |
1127 | goto unlock; | |
1128 | ||
1129 | __migrate_swap_task(arg->src_task, arg->dst_cpu); | |
1130 | __migrate_swap_task(arg->dst_task, arg->src_cpu); | |
1131 | ||
1132 | ret = 0; | |
1133 | ||
1134 | unlock: | |
1135 | double_rq_unlock(src_rq, dst_rq); | |
74602315 PZ |
1136 | raw_spin_unlock(&arg->dst_task->pi_lock); |
1137 | raw_spin_unlock(&arg->src_task->pi_lock); | |
ac66f547 PZ |
1138 | |
1139 | return ret; | |
1140 | } | |
1141 | ||
1142 | /* | |
1143 | * Cross migrate two tasks | |
1144 | */ | |
1145 | int migrate_swap(struct task_struct *cur, struct task_struct *p) | |
1146 | { | |
1147 | struct migration_swap_arg arg; | |
1148 | int ret = -EINVAL; | |
1149 | ||
ac66f547 PZ |
1150 | arg = (struct migration_swap_arg){ |
1151 | .src_task = cur, | |
1152 | .src_cpu = task_cpu(cur), | |
1153 | .dst_task = p, | |
1154 | .dst_cpu = task_cpu(p), | |
1155 | }; | |
1156 | ||
1157 | if (arg.src_cpu == arg.dst_cpu) | |
1158 | goto out; | |
1159 | ||
6acce3ef PZ |
1160 | /* |
1161 | * These three tests are all lockless; this is OK since all of them | |
1162 | * will be re-checked with proper locks held further down the line. | |
1163 | */ | |
ac66f547 PZ |
1164 | if (!cpu_active(arg.src_cpu) || !cpu_active(arg.dst_cpu)) |
1165 | goto out; | |
1166 | ||
1167 | if (!cpumask_test_cpu(arg.dst_cpu, tsk_cpus_allowed(arg.src_task))) | |
1168 | goto out; | |
1169 | ||
1170 | if (!cpumask_test_cpu(arg.src_cpu, tsk_cpus_allowed(arg.dst_task))) | |
1171 | goto out; | |
1172 | ||
286549dc | 1173 | trace_sched_swap_numa(cur, arg.src_cpu, p, arg.dst_cpu); |
ac66f547 PZ |
1174 | ret = stop_two_cpus(arg.dst_cpu, arg.src_cpu, migrate_swap_stop, &arg); |
1175 | ||
1176 | out: | |
ac66f547 PZ |
1177 | return ret; |
1178 | } | |
1179 | ||
969c7921 | 1180 | struct migration_arg { |
36c8b586 | 1181 | struct task_struct *task; |
1da177e4 | 1182 | int dest_cpu; |
70b97a7f | 1183 | }; |
1da177e4 | 1184 | |
969c7921 TH |
1185 | static int migration_cpu_stop(void *data); |
1186 | ||
1da177e4 LT |
1187 | /* |
1188 | * wait_task_inactive - wait for a thread to unschedule. | |
1189 | * | |
85ba2d86 RM |
1190 | * If @match_state is nonzero, it's the @p->state value just checked and |
1191 | * not expected to change. If it changes, i.e. @p might have woken up, | |
1192 | * then return zero. When we succeed in waiting for @p to be off its CPU, | |
1193 | * we return a positive number (its total switch count). If a second call | |
1194 | * a short while later returns the same number, the caller can be sure that | |
1195 | * @p has remained unscheduled the whole time. | |
1196 | * | |
1da177e4 LT |
1197 | * The caller must ensure that the task *will* unschedule sometime soon, |
1198 | * else this function might spin for a *long* time. This function can't | |
1199 | * be called with interrupts off, or it may introduce deadlock with | |
1200 | * smp_call_function() if an IPI is sent by the same process we are | |
1201 | * waiting to become inactive. | |
1202 | */ | |
85ba2d86 | 1203 | unsigned long wait_task_inactive(struct task_struct *p, long match_state) |
1da177e4 LT |
1204 | { |
1205 | unsigned long flags; | |
dd41f596 | 1206 | int running, on_rq; |
85ba2d86 | 1207 | unsigned long ncsw; |
70b97a7f | 1208 | struct rq *rq; |
1da177e4 | 1209 | |
3a5c359a AK |
1210 | for (;;) { |
1211 | /* | |
1212 | * We do the initial early heuristics without holding | |
1213 | * any task-queue locks at all. We'll only try to get | |
1214 | * the runqueue lock when things look like they will | |
1215 | * work out! | |
1216 | */ | |
1217 | rq = task_rq(p); | |
fa490cfd | 1218 | |
3a5c359a AK |
1219 | /* |
1220 | * If the task is actively running on another CPU | |
1221 | * still, just relax and busy-wait without holding | |
1222 | * any locks. | |
1223 | * | |
1224 | * NOTE! Since we don't hold any locks, it's not | |
1225 | * even sure that "rq" stays as the right runqueue! | |
1226 | * But we don't care, since "task_running()" will | |
1227 | * return false if the runqueue has changed and p | |
1228 | * is actually now running somewhere else! | |
1229 | */ | |
85ba2d86 RM |
1230 | while (task_running(rq, p)) { |
1231 | if (match_state && unlikely(p->state != match_state)) | |
1232 | return 0; | |
3a5c359a | 1233 | cpu_relax(); |
85ba2d86 | 1234 | } |
fa490cfd | 1235 | |
3a5c359a AK |
1236 | /* |
1237 | * Ok, time to look more closely! We need the rq | |
1238 | * lock now, to be *sure*. If we're wrong, we'll | |
1239 | * just go back and repeat. | |
1240 | */ | |
1241 | rq = task_rq_lock(p, &flags); | |
27a9da65 | 1242 | trace_sched_wait_task(p); |
3a5c359a | 1243 | running = task_running(rq, p); |
fd2f4419 | 1244 | on_rq = p->on_rq; |
85ba2d86 | 1245 | ncsw = 0; |
f31e11d8 | 1246 | if (!match_state || p->state == match_state) |
93dcf55f | 1247 | ncsw = p->nvcsw | LONG_MIN; /* sets MSB */ |
0122ec5b | 1248 | task_rq_unlock(rq, p, &flags); |
fa490cfd | 1249 | |
85ba2d86 RM |
1250 | /* |
1251 | * If it changed from the expected state, bail out now. | |
1252 | */ | |
1253 | if (unlikely(!ncsw)) | |
1254 | break; | |
1255 | ||
3a5c359a AK |
1256 | /* |
1257 | * Was it really running after all now that we | |
1258 | * checked with the proper locks actually held? | |
1259 | * | |
1260 | * Oops. Go back and try again.. | |
1261 | */ | |
1262 | if (unlikely(running)) { | |
1263 | cpu_relax(); | |
1264 | continue; | |
1265 | } | |
fa490cfd | 1266 | |
3a5c359a AK |
1267 | /* |
1268 | * It's not enough that it's not actively running, | |
1269 | * it must be off the runqueue _entirely_, and not | |
1270 | * preempted! | |
1271 | * | |
80dd99b3 | 1272 | * So if it was still runnable (but just not actively |
3a5c359a AK |
1273 | * running right now), it's preempted, and we should |
1274 | * yield - it could be a while. | |
1275 | */ | |
1276 | if (unlikely(on_rq)) { | |
8eb90c30 TG |
1277 | ktime_t to = ktime_set(0, NSEC_PER_SEC/HZ); |
1278 | ||
1279 | set_current_state(TASK_UNINTERRUPTIBLE); | |
1280 | schedule_hrtimeout(&to, HRTIMER_MODE_REL); | |
3a5c359a AK |
1281 | continue; |
1282 | } | |
fa490cfd | 1283 | |
3a5c359a AK |
1284 | /* |
1285 | * Ahh, all good. It wasn't running, and it wasn't | |
1286 | * runnable, which means that it will never become | |
1287 | * running in the future either. We're all done! | |
1288 | */ | |
1289 | break; | |
1290 | } | |
85ba2d86 RM |
1291 | |
1292 | return ncsw; | |
1da177e4 LT |
1293 | } |
1294 | ||
1295 | /*** | |
1296 | * kick_process - kick a running thread to enter/exit the kernel | |
1297 | * @p: the to-be-kicked thread | |
1298 | * | |
1299 | * Cause a process which is running on another CPU to enter | |
1300 | * kernel-mode, without any delay. (to get signals handled.) | |
1301 | * | |
25985edc | 1302 | * NOTE: this function doesn't have to take the runqueue lock, |
1da177e4 LT |
1303 | * because all it wants to ensure is that the remote task enters |
1304 | * the kernel. If the IPI races and the task has been migrated | |
1305 | * to another CPU then no harm is done and the purpose has been | |
1306 | * achieved as well. | |
1307 | */ | |
36c8b586 | 1308 | void kick_process(struct task_struct *p) |
1da177e4 LT |
1309 | { |
1310 | int cpu; | |
1311 | ||
1312 | preempt_disable(); | |
1313 | cpu = task_cpu(p); | |
1314 | if ((cpu != smp_processor_id()) && task_curr(p)) | |
1315 | smp_send_reschedule(cpu); | |
1316 | preempt_enable(); | |
1317 | } | |
b43e3521 | 1318 | EXPORT_SYMBOL_GPL(kick_process); |
476d139c | 1319 | #endif /* CONFIG_SMP */ |
1da177e4 | 1320 | |
970b13ba | 1321 | #ifdef CONFIG_SMP |
30da688e | 1322 | /* |
013fdb80 | 1323 | * ->cpus_allowed is protected by both rq->lock and p->pi_lock |
30da688e | 1324 | */ |
5da9a0fb PZ |
1325 | static int select_fallback_rq(int cpu, struct task_struct *p) |
1326 | { | |
aa00d89c TC |
1327 | int nid = cpu_to_node(cpu); |
1328 | const struct cpumask *nodemask = NULL; | |
2baab4e9 PZ |
1329 | enum { cpuset, possible, fail } state = cpuset; |
1330 | int dest_cpu; | |
5da9a0fb | 1331 | |
aa00d89c TC |
1332 | /* |
1333 | * If the node that the cpu is on has been offlined, cpu_to_node() | |
1334 | * will return -1. There is no cpu on the node, and we should | |
1335 | * select the cpu on the other node. | |
1336 | */ | |
1337 | if (nid != -1) { | |
1338 | nodemask = cpumask_of_node(nid); | |
1339 | ||
1340 | /* Look for allowed, online CPU in same node. */ | |
1341 | for_each_cpu(dest_cpu, nodemask) { | |
1342 | if (!cpu_online(dest_cpu)) | |
1343 | continue; | |
1344 | if (!cpu_active(dest_cpu)) | |
1345 | continue; | |
1346 | if (cpumask_test_cpu(dest_cpu, tsk_cpus_allowed(p))) | |
1347 | return dest_cpu; | |
1348 | } | |
2baab4e9 | 1349 | } |
5da9a0fb | 1350 | |
2baab4e9 PZ |
1351 | for (;;) { |
1352 | /* Any allowed, online CPU? */ | |
e3831edd | 1353 | for_each_cpu(dest_cpu, tsk_cpus_allowed(p)) { |
2baab4e9 PZ |
1354 | if (!cpu_online(dest_cpu)) |
1355 | continue; | |
1356 | if (!cpu_active(dest_cpu)) | |
1357 | continue; | |
1358 | goto out; | |
1359 | } | |
5da9a0fb | 1360 | |
2baab4e9 PZ |
1361 | switch (state) { |
1362 | case cpuset: | |
1363 | /* No more Mr. Nice Guy. */ | |
1364 | cpuset_cpus_allowed_fallback(p); | |
1365 | state = possible; | |
1366 | break; | |
1367 | ||
1368 | case possible: | |
1369 | do_set_cpus_allowed(p, cpu_possible_mask); | |
1370 | state = fail; | |
1371 | break; | |
1372 | ||
1373 | case fail: | |
1374 | BUG(); | |
1375 | break; | |
1376 | } | |
1377 | } | |
1378 | ||
1379 | out: | |
1380 | if (state != cpuset) { | |
1381 | /* | |
1382 | * Don't tell them about moving exiting tasks or | |
1383 | * kernel threads (both mm NULL), since they never | |
1384 | * leave kernel. | |
1385 | */ | |
1386 | if (p->mm && printk_ratelimit()) { | |
aac74dc4 | 1387 | printk_deferred("process %d (%s) no longer affine to cpu%d\n", |
2baab4e9 PZ |
1388 | task_pid_nr(p), p->comm, cpu); |
1389 | } | |
5da9a0fb PZ |
1390 | } |
1391 | ||
1392 | return dest_cpu; | |
1393 | } | |
1394 | ||
e2912009 | 1395 | /* |
013fdb80 | 1396 | * The caller (fork, wakeup) owns p->pi_lock, ->cpus_allowed is stable. |
e2912009 | 1397 | */ |
970b13ba | 1398 | static inline |
ac66f547 | 1399 | int select_task_rq(struct task_struct *p, int cpu, int sd_flags, int wake_flags) |
970b13ba | 1400 | { |
ac66f547 | 1401 | cpu = p->sched_class->select_task_rq(p, cpu, sd_flags, wake_flags); |
e2912009 PZ |
1402 | |
1403 | /* | |
1404 | * In order not to call set_task_cpu() on a blocking task we need | |
1405 | * to rely on ttwu() to place the task on a valid ->cpus_allowed | |
1406 | * cpu. | |
1407 | * | |
1408 | * Since this is common to all placement strategies, this lives here. | |
1409 | * | |
1410 | * [ this allows ->select_task() to simply return task_cpu(p) and | |
1411 | * not worry about this generic constraint ] | |
1412 | */ | |
fa17b507 | 1413 | if (unlikely(!cpumask_test_cpu(cpu, tsk_cpus_allowed(p)) || |
70f11205 | 1414 | !cpu_online(cpu))) |
5da9a0fb | 1415 | cpu = select_fallback_rq(task_cpu(p), p); |
e2912009 PZ |
1416 | |
1417 | return cpu; | |
970b13ba | 1418 | } |
09a40af5 MG |
1419 | |
1420 | static void update_avg(u64 *avg, u64 sample) | |
1421 | { | |
1422 | s64 diff = sample - *avg; | |
1423 | *avg += diff >> 3; | |
1424 | } | |
970b13ba PZ |
1425 | #endif |
1426 | ||
d7c01d27 | 1427 | static void |
b84cb5df | 1428 | ttwu_stat(struct task_struct *p, int cpu, int wake_flags) |
9ed3811a | 1429 | { |
d7c01d27 | 1430 | #ifdef CONFIG_SCHEDSTATS |
b84cb5df PZ |
1431 | struct rq *rq = this_rq(); |
1432 | ||
d7c01d27 PZ |
1433 | #ifdef CONFIG_SMP |
1434 | int this_cpu = smp_processor_id(); | |
1435 | ||
1436 | if (cpu == this_cpu) { | |
1437 | schedstat_inc(rq, ttwu_local); | |
1438 | schedstat_inc(p, se.statistics.nr_wakeups_local); | |
1439 | } else { | |
1440 | struct sched_domain *sd; | |
1441 | ||
1442 | schedstat_inc(p, se.statistics.nr_wakeups_remote); | |
057f3fad | 1443 | rcu_read_lock(); |
d7c01d27 PZ |
1444 | for_each_domain(this_cpu, sd) { |
1445 | if (cpumask_test_cpu(cpu, sched_domain_span(sd))) { | |
1446 | schedstat_inc(sd, ttwu_wake_remote); | |
1447 | break; | |
1448 | } | |
1449 | } | |
057f3fad | 1450 | rcu_read_unlock(); |
d7c01d27 | 1451 | } |
f339b9dc PZ |
1452 | |
1453 | if (wake_flags & WF_MIGRATED) | |
1454 | schedstat_inc(p, se.statistics.nr_wakeups_migrate); | |
1455 | ||
d7c01d27 PZ |
1456 | #endif /* CONFIG_SMP */ |
1457 | ||
1458 | schedstat_inc(rq, ttwu_count); | |
9ed3811a | 1459 | schedstat_inc(p, se.statistics.nr_wakeups); |
d7c01d27 PZ |
1460 | |
1461 | if (wake_flags & WF_SYNC) | |
9ed3811a | 1462 | schedstat_inc(p, se.statistics.nr_wakeups_sync); |
d7c01d27 | 1463 | |
d7c01d27 PZ |
1464 | #endif /* CONFIG_SCHEDSTATS */ |
1465 | } | |
1466 | ||
1467 | static void ttwu_activate(struct rq *rq, struct task_struct *p, int en_flags) | |
1468 | { | |
9ed3811a | 1469 | activate_task(rq, p, en_flags); |
fd2f4419 | 1470 | p->on_rq = 1; |
c2f7115e PZ |
1471 | |
1472 | /* if a worker is waking up, notify workqueue */ | |
1473 | if (p->flags & PF_WQ_WORKER) | |
1474 | wq_worker_waking_up(p, cpu_of(rq)); | |
9ed3811a TH |
1475 | } |
1476 | ||
23f41eeb PZ |
1477 | /* |
1478 | * Mark the task runnable and perform wakeup-preemption. | |
1479 | */ | |
89363381 | 1480 | static void |
23f41eeb | 1481 | ttwu_do_wakeup(struct rq *rq, struct task_struct *p, int wake_flags) |
9ed3811a | 1482 | { |
9ed3811a | 1483 | check_preempt_curr(rq, p, wake_flags); |
a8d7ad52 | 1484 | trace_sched_wakeup(p, true); |
9ed3811a TH |
1485 | |
1486 | p->state = TASK_RUNNING; | |
1487 | #ifdef CONFIG_SMP | |
1488 | if (p->sched_class->task_woken) | |
1489 | p->sched_class->task_woken(rq, p); | |
1490 | ||
e69c6341 | 1491 | if (rq->idle_stamp) { |
78becc27 | 1492 | u64 delta = rq_clock(rq) - rq->idle_stamp; |
9bd721c5 | 1493 | u64 max = 2*rq->max_idle_balance_cost; |
9ed3811a | 1494 | |
abfafa54 JL |
1495 | update_avg(&rq->avg_idle, delta); |
1496 | ||
1497 | if (rq->avg_idle > max) | |
9ed3811a | 1498 | rq->avg_idle = max; |
abfafa54 | 1499 | |
9ed3811a TH |
1500 | rq->idle_stamp = 0; |
1501 | } | |
1502 | #endif | |
1503 | } | |
1504 | ||
c05fbafb PZ |
1505 | static void |
1506 | ttwu_do_activate(struct rq *rq, struct task_struct *p, int wake_flags) | |
1507 | { | |
1508 | #ifdef CONFIG_SMP | |
1509 | if (p->sched_contributes_to_load) | |
1510 | rq->nr_uninterruptible--; | |
1511 | #endif | |
1512 | ||
1513 | ttwu_activate(rq, p, ENQUEUE_WAKEUP | ENQUEUE_WAKING); | |
1514 | ttwu_do_wakeup(rq, p, wake_flags); | |
1515 | } | |
1516 | ||
1517 | /* | |
1518 | * Called in case the task @p isn't fully descheduled from its runqueue, | |
1519 | * in this case we must do a remote wakeup. Its a 'light' wakeup though, | |
1520 | * since all we need to do is flip p->state to TASK_RUNNING, since | |
1521 | * the task is still ->on_rq. | |
1522 | */ | |
1523 | static int ttwu_remote(struct task_struct *p, int wake_flags) | |
1524 | { | |
1525 | struct rq *rq; | |
1526 | int ret = 0; | |
1527 | ||
1528 | rq = __task_rq_lock(p); | |
1529 | if (p->on_rq) { | |
1ad4ec0d FW |
1530 | /* check_preempt_curr() may use rq clock */ |
1531 | update_rq_clock(rq); | |
c05fbafb PZ |
1532 | ttwu_do_wakeup(rq, p, wake_flags); |
1533 | ret = 1; | |
1534 | } | |
1535 | __task_rq_unlock(rq); | |
1536 | ||
1537 | return ret; | |
1538 | } | |
1539 | ||
317f3941 | 1540 | #ifdef CONFIG_SMP |
e3baac47 | 1541 | void sched_ttwu_pending(void) |
317f3941 PZ |
1542 | { |
1543 | struct rq *rq = this_rq(); | |
fa14ff4a PZ |
1544 | struct llist_node *llist = llist_del_all(&rq->wake_list); |
1545 | struct task_struct *p; | |
e3baac47 | 1546 | unsigned long flags; |
317f3941 | 1547 | |
e3baac47 PZ |
1548 | if (!llist) |
1549 | return; | |
1550 | ||
1551 | raw_spin_lock_irqsave(&rq->lock, flags); | |
317f3941 | 1552 | |
fa14ff4a PZ |
1553 | while (llist) { |
1554 | p = llist_entry(llist, struct task_struct, wake_entry); | |
1555 | llist = llist_next(llist); | |
317f3941 PZ |
1556 | ttwu_do_activate(rq, p, 0); |
1557 | } | |
1558 | ||
e3baac47 | 1559 | raw_spin_unlock_irqrestore(&rq->lock, flags); |
317f3941 PZ |
1560 | } |
1561 | ||
1562 | void scheduler_ipi(void) | |
1563 | { | |
f27dde8d PZ |
1564 | /* |
1565 | * Fold TIF_NEED_RESCHED into the preempt_count; anybody setting | |
1566 | * TIF_NEED_RESCHED remotely (for the first time) will also send | |
1567 | * this IPI. | |
1568 | */ | |
8cb75e0c | 1569 | preempt_fold_need_resched(); |
f27dde8d | 1570 | |
873b4c65 VG |
1571 | if (llist_empty(&this_rq()->wake_list) |
1572 | && !tick_nohz_full_cpu(smp_processor_id()) | |
1573 | && !got_nohz_idle_kick()) | |
c5d753a5 PZ |
1574 | return; |
1575 | ||
1576 | /* | |
1577 | * Not all reschedule IPI handlers call irq_enter/irq_exit, since | |
1578 | * traditionally all their work was done from the interrupt return | |
1579 | * path. Now that we actually do some work, we need to make sure | |
1580 | * we do call them. | |
1581 | * | |
1582 | * Some archs already do call them, luckily irq_enter/exit nest | |
1583 | * properly. | |
1584 | * | |
1585 | * Arguably we should visit all archs and update all handlers, | |
1586 | * however a fair share of IPIs are still resched only so this would | |
1587 | * somewhat pessimize the simple resched case. | |
1588 | */ | |
1589 | irq_enter(); | |
ff442c51 | 1590 | tick_nohz_full_check(); |
fa14ff4a | 1591 | sched_ttwu_pending(); |
ca38062e SS |
1592 | |
1593 | /* | |
1594 | * Check if someone kicked us for doing the nohz idle load balance. | |
1595 | */ | |
873b4c65 | 1596 | if (unlikely(got_nohz_idle_kick())) { |
6eb57e0d | 1597 | this_rq()->idle_balance = 1; |
ca38062e | 1598 | raise_softirq_irqoff(SCHED_SOFTIRQ); |
6eb57e0d | 1599 | } |
c5d753a5 | 1600 | irq_exit(); |
317f3941 PZ |
1601 | } |
1602 | ||
1603 | static void ttwu_queue_remote(struct task_struct *p, int cpu) | |
1604 | { | |
e3baac47 PZ |
1605 | struct rq *rq = cpu_rq(cpu); |
1606 | ||
1607 | if (llist_add(&p->wake_entry, &cpu_rq(cpu)->wake_list)) { | |
1608 | if (!set_nr_if_polling(rq->idle)) | |
1609 | smp_send_reschedule(cpu); | |
1610 | else | |
1611 | trace_sched_wake_idle_without_ipi(cpu); | |
1612 | } | |
317f3941 | 1613 | } |
d6aa8f85 | 1614 | |
39be3501 | 1615 | bool cpus_share_cache(int this_cpu, int that_cpu) |
518cd623 PZ |
1616 | { |
1617 | return per_cpu(sd_llc_id, this_cpu) == per_cpu(sd_llc_id, that_cpu); | |
1618 | } | |
d6aa8f85 | 1619 | #endif /* CONFIG_SMP */ |
317f3941 | 1620 | |
c05fbafb PZ |
1621 | static void ttwu_queue(struct task_struct *p, int cpu) |
1622 | { | |
1623 | struct rq *rq = cpu_rq(cpu); | |
1624 | ||
17d9f311 | 1625 | #if defined(CONFIG_SMP) |
39be3501 | 1626 | if (sched_feat(TTWU_QUEUE) && !cpus_share_cache(smp_processor_id(), cpu)) { |
f01114cb | 1627 | sched_clock_cpu(cpu); /* sync clocks x-cpu */ |
317f3941 PZ |
1628 | ttwu_queue_remote(p, cpu); |
1629 | return; | |
1630 | } | |
1631 | #endif | |
1632 | ||
c05fbafb PZ |
1633 | raw_spin_lock(&rq->lock); |
1634 | ttwu_do_activate(rq, p, 0); | |
1635 | raw_spin_unlock(&rq->lock); | |
9ed3811a TH |
1636 | } |
1637 | ||
1638 | /** | |
1da177e4 | 1639 | * try_to_wake_up - wake up a thread |
9ed3811a | 1640 | * @p: the thread to be awakened |
1da177e4 | 1641 | * @state: the mask of task states that can be woken |
9ed3811a | 1642 | * @wake_flags: wake modifier flags (WF_*) |
1da177e4 LT |
1643 | * |
1644 | * Put it on the run-queue if it's not already there. The "current" | |
1645 | * thread is always on the run-queue (except when the actual | |
1646 | * re-schedule is in progress), and as such you're allowed to do | |
1647 | * the simpler "current->state = TASK_RUNNING" to mark yourself | |
1648 | * runnable without the overhead of this. | |
1649 | * | |
e69f6186 | 1650 | * Return: %true if @p was woken up, %false if it was already running. |
9ed3811a | 1651 | * or @state didn't match @p's state. |
1da177e4 | 1652 | */ |
e4a52bcb PZ |
1653 | static int |
1654 | try_to_wake_up(struct task_struct *p, unsigned int state, int wake_flags) | |
1da177e4 | 1655 | { |
1da177e4 | 1656 | unsigned long flags; |
c05fbafb | 1657 | int cpu, success = 0; |
2398f2c6 | 1658 | |
e0acd0a6 ON |
1659 | /* |
1660 | * If we are going to wake up a thread waiting for CONDITION we | |
1661 | * need to ensure that CONDITION=1 done by the caller can not be | |
1662 | * reordered with p->state check below. This pairs with mb() in | |
1663 | * set_current_state() the waiting thread does. | |
1664 | */ | |
1665 | smp_mb__before_spinlock(); | |
013fdb80 | 1666 | raw_spin_lock_irqsave(&p->pi_lock, flags); |
e9c84311 | 1667 | if (!(p->state & state)) |
1da177e4 LT |
1668 | goto out; |
1669 | ||
c05fbafb | 1670 | success = 1; /* we're going to change ->state */ |
1da177e4 | 1671 | cpu = task_cpu(p); |
1da177e4 | 1672 | |
c05fbafb PZ |
1673 | if (p->on_rq && ttwu_remote(p, wake_flags)) |
1674 | goto stat; | |
1da177e4 | 1675 | |
1da177e4 | 1676 | #ifdef CONFIG_SMP |
e9c84311 | 1677 | /* |
c05fbafb PZ |
1678 | * If the owning (remote) cpu is still in the middle of schedule() with |
1679 | * this task as prev, wait until its done referencing the task. | |
e9c84311 | 1680 | */ |
f3e94786 | 1681 | while (p->on_cpu) |
e4a52bcb | 1682 | cpu_relax(); |
0970d299 | 1683 | /* |
e4a52bcb | 1684 | * Pairs with the smp_wmb() in finish_lock_switch(). |
0970d299 | 1685 | */ |
e4a52bcb | 1686 | smp_rmb(); |
1da177e4 | 1687 | |
a8e4f2ea | 1688 | p->sched_contributes_to_load = !!task_contributes_to_load(p); |
e9c84311 | 1689 | p->state = TASK_WAKING; |
e7693a36 | 1690 | |
e4a52bcb | 1691 | if (p->sched_class->task_waking) |
74f8e4b2 | 1692 | p->sched_class->task_waking(p); |
efbbd05a | 1693 | |
ac66f547 | 1694 | cpu = select_task_rq(p, p->wake_cpu, SD_BALANCE_WAKE, wake_flags); |
f339b9dc PZ |
1695 | if (task_cpu(p) != cpu) { |
1696 | wake_flags |= WF_MIGRATED; | |
e4a52bcb | 1697 | set_task_cpu(p, cpu); |
f339b9dc | 1698 | } |
1da177e4 | 1699 | #endif /* CONFIG_SMP */ |
1da177e4 | 1700 | |
c05fbafb PZ |
1701 | ttwu_queue(p, cpu); |
1702 | stat: | |
b84cb5df | 1703 | ttwu_stat(p, cpu, wake_flags); |
1da177e4 | 1704 | out: |
013fdb80 | 1705 | raw_spin_unlock_irqrestore(&p->pi_lock, flags); |
1da177e4 LT |
1706 | |
1707 | return success; | |
1708 | } | |
1709 | ||
21aa9af0 TH |
1710 | /** |
1711 | * try_to_wake_up_local - try to wake up a local task with rq lock held | |
1712 | * @p: the thread to be awakened | |
1713 | * | |
2acca55e | 1714 | * Put @p on the run-queue if it's not already there. The caller must |
21aa9af0 | 1715 | * ensure that this_rq() is locked, @p is bound to this_rq() and not |
2acca55e | 1716 | * the current task. |
21aa9af0 TH |
1717 | */ |
1718 | static void try_to_wake_up_local(struct task_struct *p) | |
1719 | { | |
1720 | struct rq *rq = task_rq(p); | |
21aa9af0 | 1721 | |
383efcd0 TH |
1722 | if (WARN_ON_ONCE(rq != this_rq()) || |
1723 | WARN_ON_ONCE(p == current)) | |
1724 | return; | |
1725 | ||
21aa9af0 TH |
1726 | lockdep_assert_held(&rq->lock); |
1727 | ||
2acca55e PZ |
1728 | if (!raw_spin_trylock(&p->pi_lock)) { |
1729 | raw_spin_unlock(&rq->lock); | |
1730 | raw_spin_lock(&p->pi_lock); | |
1731 | raw_spin_lock(&rq->lock); | |
1732 | } | |
1733 | ||
21aa9af0 | 1734 | if (!(p->state & TASK_NORMAL)) |
2acca55e | 1735 | goto out; |
21aa9af0 | 1736 | |
fd2f4419 | 1737 | if (!p->on_rq) |
d7c01d27 PZ |
1738 | ttwu_activate(rq, p, ENQUEUE_WAKEUP); |
1739 | ||
23f41eeb | 1740 | ttwu_do_wakeup(rq, p, 0); |
b84cb5df | 1741 | ttwu_stat(p, smp_processor_id(), 0); |
2acca55e PZ |
1742 | out: |
1743 | raw_spin_unlock(&p->pi_lock); | |
21aa9af0 TH |
1744 | } |
1745 | ||
50fa610a DH |
1746 | /** |
1747 | * wake_up_process - Wake up a specific process | |
1748 | * @p: The process to be woken up. | |
1749 | * | |
1750 | * Attempt to wake up the nominated process and move it to the set of runnable | |
e69f6186 YB |
1751 | * processes. |
1752 | * | |
1753 | * Return: 1 if the process was woken up, 0 if it was already running. | |
50fa610a DH |
1754 | * |
1755 | * It may be assumed that this function implies a write memory barrier before | |
1756 | * changing the task state if and only if any tasks are woken up. | |
1757 | */ | |
7ad5b3a5 | 1758 | int wake_up_process(struct task_struct *p) |
1da177e4 | 1759 | { |
9067ac85 ON |
1760 | WARN_ON(task_is_stopped_or_traced(p)); |
1761 | return try_to_wake_up(p, TASK_NORMAL, 0); | |
1da177e4 | 1762 | } |
1da177e4 LT |
1763 | EXPORT_SYMBOL(wake_up_process); |
1764 | ||
7ad5b3a5 | 1765 | int wake_up_state(struct task_struct *p, unsigned int state) |
1da177e4 LT |
1766 | { |
1767 | return try_to_wake_up(p, state, 0); | |
1768 | } | |
1769 | ||
1da177e4 LT |
1770 | /* |
1771 | * Perform scheduler related setup for a newly forked process p. | |
1772 | * p is forked by current. | |
dd41f596 IM |
1773 | * |
1774 | * __sched_fork() is basic setup used by init_idle() too: | |
1775 | */ | |
5e1576ed | 1776 | static void __sched_fork(unsigned long clone_flags, struct task_struct *p) |
dd41f596 | 1777 | { |
fd2f4419 PZ |
1778 | p->on_rq = 0; |
1779 | ||
1780 | p->se.on_rq = 0; | |
dd41f596 IM |
1781 | p->se.exec_start = 0; |
1782 | p->se.sum_exec_runtime = 0; | |
f6cf891c | 1783 | p->se.prev_sum_exec_runtime = 0; |
6c594c21 | 1784 | p->se.nr_migrations = 0; |
da7a735e | 1785 | p->se.vruntime = 0; |
fd2f4419 | 1786 | INIT_LIST_HEAD(&p->se.group_node); |
6cfb0d5d IM |
1787 | |
1788 | #ifdef CONFIG_SCHEDSTATS | |
41acab88 | 1789 | memset(&p->se.statistics, 0, sizeof(p->se.statistics)); |
6cfb0d5d | 1790 | #endif |
476d139c | 1791 | |
aab03e05 DF |
1792 | RB_CLEAR_NODE(&p->dl.rb_node); |
1793 | hrtimer_init(&p->dl.dl_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); | |
1794 | p->dl.dl_runtime = p->dl.runtime = 0; | |
1795 | p->dl.dl_deadline = p->dl.deadline = 0; | |
755378a4 | 1796 | p->dl.dl_period = 0; |
aab03e05 DF |
1797 | p->dl.flags = 0; |
1798 | ||
fa717060 | 1799 | INIT_LIST_HEAD(&p->rt.run_list); |
476d139c | 1800 | |
e107be36 AK |
1801 | #ifdef CONFIG_PREEMPT_NOTIFIERS |
1802 | INIT_HLIST_HEAD(&p->preempt_notifiers); | |
1803 | #endif | |
cbee9f88 PZ |
1804 | |
1805 | #ifdef CONFIG_NUMA_BALANCING | |
1806 | if (p->mm && atomic_read(&p->mm->mm_users) == 1) { | |
7e8d16b6 | 1807 | p->mm->numa_next_scan = jiffies + msecs_to_jiffies(sysctl_numa_balancing_scan_delay); |
cbee9f88 PZ |
1808 | p->mm->numa_scan_seq = 0; |
1809 | } | |
1810 | ||
5e1576ed RR |
1811 | if (clone_flags & CLONE_VM) |
1812 | p->numa_preferred_nid = current->numa_preferred_nid; | |
1813 | else | |
1814 | p->numa_preferred_nid = -1; | |
1815 | ||
cbee9f88 PZ |
1816 | p->node_stamp = 0ULL; |
1817 | p->numa_scan_seq = p->mm ? p->mm->numa_scan_seq : 0; | |
4b96a29b | 1818 | p->numa_scan_period = sysctl_numa_balancing_scan_delay; |
cbee9f88 | 1819 | p->numa_work.next = &p->numa_work; |
ff1df896 RR |
1820 | p->numa_faults_memory = NULL; |
1821 | p->numa_faults_buffer_memory = NULL; | |
7e2703e6 RR |
1822 | p->last_task_numa_placement = 0; |
1823 | p->last_sum_exec_runtime = 0; | |
8c8a743c PZ |
1824 | |
1825 | INIT_LIST_HEAD(&p->numa_entry); | |
1826 | p->numa_group = NULL; | |
cbee9f88 | 1827 | #endif /* CONFIG_NUMA_BALANCING */ |
dd41f596 IM |
1828 | } |
1829 | ||
1a687c2e | 1830 | #ifdef CONFIG_NUMA_BALANCING |
3105b86a | 1831 | #ifdef CONFIG_SCHED_DEBUG |
1a687c2e MG |
1832 | void set_numabalancing_state(bool enabled) |
1833 | { | |
1834 | if (enabled) | |
1835 | sched_feat_set("NUMA"); | |
1836 | else | |
1837 | sched_feat_set("NO_NUMA"); | |
1838 | } | |
3105b86a MG |
1839 | #else |
1840 | __read_mostly bool numabalancing_enabled; | |
1841 | ||
1842 | void set_numabalancing_state(bool enabled) | |
1843 | { | |
1844 | numabalancing_enabled = enabled; | |
dd41f596 | 1845 | } |
3105b86a | 1846 | #endif /* CONFIG_SCHED_DEBUG */ |
54a43d54 AK |
1847 | |
1848 | #ifdef CONFIG_PROC_SYSCTL | |
1849 | int sysctl_numa_balancing(struct ctl_table *table, int write, | |
1850 | void __user *buffer, size_t *lenp, loff_t *ppos) | |
1851 | { | |
1852 | struct ctl_table t; | |
1853 | int err; | |
1854 | int state = numabalancing_enabled; | |
1855 | ||
1856 | if (write && !capable(CAP_SYS_ADMIN)) | |
1857 | return -EPERM; | |
1858 | ||
1859 | t = *table; | |
1860 | t.data = &state; | |
1861 | err = proc_dointvec_minmax(&t, write, buffer, lenp, ppos); | |
1862 | if (err < 0) | |
1863 | return err; | |
1864 | if (write) | |
1865 | set_numabalancing_state(state); | |
1866 | return err; | |
1867 | } | |
1868 | #endif | |
1869 | #endif | |
dd41f596 IM |
1870 | |
1871 | /* | |
1872 | * fork()/clone()-time setup: | |
1873 | */ | |
aab03e05 | 1874 | int sched_fork(unsigned long clone_flags, struct task_struct *p) |
dd41f596 | 1875 | { |
0122ec5b | 1876 | unsigned long flags; |
dd41f596 IM |
1877 | int cpu = get_cpu(); |
1878 | ||
5e1576ed | 1879 | __sched_fork(clone_flags, p); |
06b83b5f | 1880 | /* |
0017d735 | 1881 | * We mark the process as running here. This guarantees that |
06b83b5f PZ |
1882 | * nobody will actually run it, and a signal or other external |
1883 | * event cannot wake it up and insert it on the runqueue either. | |
1884 | */ | |
0017d735 | 1885 | p->state = TASK_RUNNING; |
dd41f596 | 1886 | |
c350a04e MG |
1887 | /* |
1888 | * Make sure we do not leak PI boosting priority to the child. | |
1889 | */ | |
1890 | p->prio = current->normal_prio; | |
1891 | ||
b9dc29e7 MG |
1892 | /* |
1893 | * Revert to default priority/policy on fork if requested. | |
1894 | */ | |
1895 | if (unlikely(p->sched_reset_on_fork)) { | |
aab03e05 | 1896 | if (task_has_dl_policy(p) || task_has_rt_policy(p)) { |
b9dc29e7 | 1897 | p->policy = SCHED_NORMAL; |
6c697bdf | 1898 | p->static_prio = NICE_TO_PRIO(0); |
c350a04e MG |
1899 | p->rt_priority = 0; |
1900 | } else if (PRIO_TO_NICE(p->static_prio) < 0) | |
1901 | p->static_prio = NICE_TO_PRIO(0); | |
1902 | ||
1903 | p->prio = p->normal_prio = __normal_prio(p); | |
1904 | set_load_weight(p); | |
6c697bdf | 1905 | |
b9dc29e7 MG |
1906 | /* |
1907 | * We don't need the reset flag anymore after the fork. It has | |
1908 | * fulfilled its duty: | |
1909 | */ | |
1910 | p->sched_reset_on_fork = 0; | |
1911 | } | |
ca94c442 | 1912 | |
aab03e05 DF |
1913 | if (dl_prio(p->prio)) { |
1914 | put_cpu(); | |
1915 | return -EAGAIN; | |
1916 | } else if (rt_prio(p->prio)) { | |
1917 | p->sched_class = &rt_sched_class; | |
1918 | } else { | |
2ddbf952 | 1919 | p->sched_class = &fair_sched_class; |
aab03e05 | 1920 | } |
b29739f9 | 1921 | |
cd29fe6f PZ |
1922 | if (p->sched_class->task_fork) |
1923 | p->sched_class->task_fork(p); | |
1924 | ||
86951599 PZ |
1925 | /* |
1926 | * The child is not yet in the pid-hash so no cgroup attach races, | |
1927 | * and the cgroup is pinned to this child due to cgroup_fork() | |
1928 | * is ran before sched_fork(). | |
1929 | * | |
1930 | * Silence PROVE_RCU. | |
1931 | */ | |
0122ec5b | 1932 | raw_spin_lock_irqsave(&p->pi_lock, flags); |
5f3edc1b | 1933 | set_task_cpu(p, cpu); |
0122ec5b | 1934 | raw_spin_unlock_irqrestore(&p->pi_lock, flags); |
5f3edc1b | 1935 | |
52f17b6c | 1936 | #if defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT) |
dd41f596 | 1937 | if (likely(sched_info_on())) |
52f17b6c | 1938 | memset(&p->sched_info, 0, sizeof(p->sched_info)); |
1da177e4 | 1939 | #endif |
3ca7a440 PZ |
1940 | #if defined(CONFIG_SMP) |
1941 | p->on_cpu = 0; | |
4866cde0 | 1942 | #endif |
01028747 | 1943 | init_task_preempt_count(p); |
806c09a7 | 1944 | #ifdef CONFIG_SMP |
917b627d | 1945 | plist_node_init(&p->pushable_tasks, MAX_PRIO); |
1baca4ce | 1946 | RB_CLEAR_NODE(&p->pushable_dl_tasks); |
806c09a7 | 1947 | #endif |
917b627d | 1948 | |
476d139c | 1949 | put_cpu(); |
aab03e05 | 1950 | return 0; |
1da177e4 LT |
1951 | } |
1952 | ||
332ac17e DF |
1953 | unsigned long to_ratio(u64 period, u64 runtime) |
1954 | { | |
1955 | if (runtime == RUNTIME_INF) | |
1956 | return 1ULL << 20; | |
1957 | ||
1958 | /* | |
1959 | * Doing this here saves a lot of checks in all | |
1960 | * the calling paths, and returning zero seems | |
1961 | * safe for them anyway. | |
1962 | */ | |
1963 | if (period == 0) | |
1964 | return 0; | |
1965 | ||
1966 | return div64_u64(runtime << 20, period); | |
1967 | } | |
1968 | ||
1969 | #ifdef CONFIG_SMP | |
1970 | inline struct dl_bw *dl_bw_of(int i) | |
1971 | { | |
1972 | return &cpu_rq(i)->rd->dl_bw; | |
1973 | } | |
1974 | ||
de212f18 | 1975 | static inline int dl_bw_cpus(int i) |
332ac17e | 1976 | { |
de212f18 PZ |
1977 | struct root_domain *rd = cpu_rq(i)->rd; |
1978 | int cpus = 0; | |
1979 | ||
1980 | for_each_cpu_and(i, rd->span, cpu_active_mask) | |
1981 | cpus++; | |
1982 | ||
1983 | return cpus; | |
332ac17e DF |
1984 | } |
1985 | #else | |
1986 | inline struct dl_bw *dl_bw_of(int i) | |
1987 | { | |
1988 | return &cpu_rq(i)->dl.dl_bw; | |
1989 | } | |
1990 | ||
de212f18 | 1991 | static inline int dl_bw_cpus(int i) |
332ac17e DF |
1992 | { |
1993 | return 1; | |
1994 | } | |
1995 | #endif | |
1996 | ||
1997 | static inline | |
1998 | void __dl_clear(struct dl_bw *dl_b, u64 tsk_bw) | |
1999 | { | |
2000 | dl_b->total_bw -= tsk_bw; | |
2001 | } | |
2002 | ||
2003 | static inline | |
2004 | void __dl_add(struct dl_bw *dl_b, u64 tsk_bw) | |
2005 | { | |
2006 | dl_b->total_bw += tsk_bw; | |
2007 | } | |
2008 | ||
2009 | static inline | |
2010 | bool __dl_overflow(struct dl_bw *dl_b, int cpus, u64 old_bw, u64 new_bw) | |
2011 | { | |
2012 | return dl_b->bw != -1 && | |
2013 | dl_b->bw * cpus < dl_b->total_bw - old_bw + new_bw; | |
2014 | } | |
2015 | ||
2016 | /* | |
2017 | * We must be sure that accepting a new task (or allowing changing the | |
2018 | * parameters of an existing one) is consistent with the bandwidth | |
2019 | * constraints. If yes, this function also accordingly updates the currently | |
2020 | * allocated bandwidth to reflect the new situation. | |
2021 | * | |
2022 | * This function is called while holding p's rq->lock. | |
2023 | */ | |
2024 | static int dl_overflow(struct task_struct *p, int policy, | |
2025 | const struct sched_attr *attr) | |
2026 | { | |
2027 | ||
2028 | struct dl_bw *dl_b = dl_bw_of(task_cpu(p)); | |
4df1638c | 2029 | u64 period = attr->sched_period ?: attr->sched_deadline; |
332ac17e DF |
2030 | u64 runtime = attr->sched_runtime; |
2031 | u64 new_bw = dl_policy(policy) ? to_ratio(period, runtime) : 0; | |
de212f18 | 2032 | int cpus, err = -1; |
332ac17e DF |
2033 | |
2034 | if (new_bw == p->dl.dl_bw) | |
2035 | return 0; | |
2036 | ||
2037 | /* | |
2038 | * Either if a task, enters, leave, or stays -deadline but changes | |
2039 | * its parameters, we may need to update accordingly the total | |
2040 | * allocated bandwidth of the container. | |
2041 | */ | |
2042 | raw_spin_lock(&dl_b->lock); | |
de212f18 | 2043 | cpus = dl_bw_cpus(task_cpu(p)); |
332ac17e DF |
2044 | if (dl_policy(policy) && !task_has_dl_policy(p) && |
2045 | !__dl_overflow(dl_b, cpus, 0, new_bw)) { | |
2046 | __dl_add(dl_b, new_bw); | |
2047 | err = 0; | |
2048 | } else if (dl_policy(policy) && task_has_dl_policy(p) && | |
2049 | !__dl_overflow(dl_b, cpus, p->dl.dl_bw, new_bw)) { | |
2050 | __dl_clear(dl_b, p->dl.dl_bw); | |
2051 | __dl_add(dl_b, new_bw); | |
2052 | err = 0; | |
2053 | } else if (!dl_policy(policy) && task_has_dl_policy(p)) { | |
2054 | __dl_clear(dl_b, p->dl.dl_bw); | |
2055 | err = 0; | |
2056 | } | |
2057 | raw_spin_unlock(&dl_b->lock); | |
2058 | ||
2059 | return err; | |
2060 | } | |
2061 | ||
2062 | extern void init_dl_bw(struct dl_bw *dl_b); | |
2063 | ||
1da177e4 LT |
2064 | /* |
2065 | * wake_up_new_task - wake up a newly created task for the first time. | |
2066 | * | |
2067 | * This function will do some initial scheduler statistics housekeeping | |
2068 | * that must be done for every newly created context, then puts the task | |
2069 | * on the runqueue and wakes it. | |
2070 | */ | |
3e51e3ed | 2071 | void wake_up_new_task(struct task_struct *p) |
1da177e4 LT |
2072 | { |
2073 | unsigned long flags; | |
dd41f596 | 2074 | struct rq *rq; |
fabf318e | 2075 | |
ab2515c4 | 2076 | raw_spin_lock_irqsave(&p->pi_lock, flags); |
fabf318e PZ |
2077 | #ifdef CONFIG_SMP |
2078 | /* | |
2079 | * Fork balancing, do it here and not earlier because: | |
2080 | * - cpus_allowed can change in the fork path | |
2081 | * - any previously selected cpu might disappear through hotplug | |
fabf318e | 2082 | */ |
ac66f547 | 2083 | set_task_cpu(p, select_task_rq(p, task_cpu(p), SD_BALANCE_FORK, 0)); |
0017d735 PZ |
2084 | #endif |
2085 | ||
a75cdaa9 AS |
2086 | /* Initialize new task's runnable average */ |
2087 | init_task_runnable_average(p); | |
ab2515c4 | 2088 | rq = __task_rq_lock(p); |
cd29fe6f | 2089 | activate_task(rq, p, 0); |
fd2f4419 | 2090 | p->on_rq = 1; |
89363381 | 2091 | trace_sched_wakeup_new(p, true); |
a7558e01 | 2092 | check_preempt_curr(rq, p, WF_FORK); |
9a897c5a | 2093 | #ifdef CONFIG_SMP |
efbbd05a PZ |
2094 | if (p->sched_class->task_woken) |
2095 | p->sched_class->task_woken(rq, p); | |
9a897c5a | 2096 | #endif |
0122ec5b | 2097 | task_rq_unlock(rq, p, &flags); |
1da177e4 LT |
2098 | } |
2099 | ||
e107be36 AK |
2100 | #ifdef CONFIG_PREEMPT_NOTIFIERS |
2101 | ||
2102 | /** | |
80dd99b3 | 2103 | * preempt_notifier_register - tell me when current is being preempted & rescheduled |
421cee29 | 2104 | * @notifier: notifier struct to register |
e107be36 AK |
2105 | */ |
2106 | void preempt_notifier_register(struct preempt_notifier *notifier) | |
2107 | { | |
2108 | hlist_add_head(¬ifier->link, ¤t->preempt_notifiers); | |
2109 | } | |
2110 | EXPORT_SYMBOL_GPL(preempt_notifier_register); | |
2111 | ||
2112 | /** | |
2113 | * preempt_notifier_unregister - no longer interested in preemption notifications | |
421cee29 | 2114 | * @notifier: notifier struct to unregister |
e107be36 AK |
2115 | * |
2116 | * This is safe to call from within a preemption notifier. | |
2117 | */ | |
2118 | void preempt_notifier_unregister(struct preempt_notifier *notifier) | |
2119 | { | |
2120 | hlist_del(¬ifier->link); | |
2121 | } | |
2122 | EXPORT_SYMBOL_GPL(preempt_notifier_unregister); | |
2123 | ||
2124 | static void fire_sched_in_preempt_notifiers(struct task_struct *curr) | |
2125 | { | |
2126 | struct preempt_notifier *notifier; | |
e107be36 | 2127 | |
b67bfe0d | 2128 | hlist_for_each_entry(notifier, &curr->preempt_notifiers, link) |
e107be36 AK |
2129 | notifier->ops->sched_in(notifier, raw_smp_processor_id()); |
2130 | } | |
2131 | ||
2132 | static void | |
2133 | fire_sched_out_preempt_notifiers(struct task_struct *curr, | |
2134 | struct task_struct *next) | |
2135 | { | |
2136 | struct preempt_notifier *notifier; | |
e107be36 | 2137 | |
b67bfe0d | 2138 | hlist_for_each_entry(notifier, &curr->preempt_notifiers, link) |
e107be36 AK |
2139 | notifier->ops->sched_out(notifier, next); |
2140 | } | |
2141 | ||
6d6bc0ad | 2142 | #else /* !CONFIG_PREEMPT_NOTIFIERS */ |
e107be36 AK |
2143 | |
2144 | static void fire_sched_in_preempt_notifiers(struct task_struct *curr) | |
2145 | { | |
2146 | } | |
2147 | ||
2148 | static void | |
2149 | fire_sched_out_preempt_notifiers(struct task_struct *curr, | |
2150 | struct task_struct *next) | |
2151 | { | |
2152 | } | |
2153 | ||
6d6bc0ad | 2154 | #endif /* CONFIG_PREEMPT_NOTIFIERS */ |
e107be36 | 2155 | |
4866cde0 NP |
2156 | /** |
2157 | * prepare_task_switch - prepare to switch tasks | |
2158 | * @rq: the runqueue preparing to switch | |
421cee29 | 2159 | * @prev: the current task that is being switched out |
4866cde0 NP |
2160 | * @next: the task we are going to switch to. |
2161 | * | |
2162 | * This is called with the rq lock held and interrupts off. It must | |
2163 | * be paired with a subsequent finish_task_switch after the context | |
2164 | * switch. | |
2165 | * | |
2166 | * prepare_task_switch sets up locking and calls architecture specific | |
2167 | * hooks. | |
2168 | */ | |
e107be36 AK |
2169 | static inline void |
2170 | prepare_task_switch(struct rq *rq, struct task_struct *prev, | |
2171 | struct task_struct *next) | |
4866cde0 | 2172 | { |
895dd92c | 2173 | trace_sched_switch(prev, next); |
43148951 | 2174 | sched_info_switch(rq, prev, next); |
fe4b04fa | 2175 | perf_event_task_sched_out(prev, next); |
e107be36 | 2176 | fire_sched_out_preempt_notifiers(prev, next); |
4866cde0 NP |
2177 | prepare_lock_switch(rq, next); |
2178 | prepare_arch_switch(next); | |
2179 | } | |
2180 | ||
1da177e4 LT |
2181 | /** |
2182 | * finish_task_switch - clean up after a task-switch | |
344babaa | 2183 | * @rq: runqueue associated with task-switch |
1da177e4 LT |
2184 | * @prev: the thread we just switched away from. |
2185 | * | |
4866cde0 NP |
2186 | * finish_task_switch must be called after the context switch, paired |
2187 | * with a prepare_task_switch call before the context switch. | |
2188 | * finish_task_switch will reconcile locking set up by prepare_task_switch, | |
2189 | * and do any other architecture-specific cleanup actions. | |
1da177e4 LT |
2190 | * |
2191 | * Note that we may have delayed dropping an mm in context_switch(). If | |
41a2d6cf | 2192 | * so, we finish that here outside of the runqueue lock. (Doing it |
1da177e4 LT |
2193 | * with the lock held can cause deadlocks; see schedule() for |
2194 | * details.) | |
2195 | */ | |
a9957449 | 2196 | static void finish_task_switch(struct rq *rq, struct task_struct *prev) |
1da177e4 LT |
2197 | __releases(rq->lock) |
2198 | { | |
1da177e4 | 2199 | struct mm_struct *mm = rq->prev_mm; |
55a101f8 | 2200 | long prev_state; |
1da177e4 LT |
2201 | |
2202 | rq->prev_mm = NULL; | |
2203 | ||
2204 | /* | |
2205 | * A task struct has one reference for the use as "current". | |
c394cc9f | 2206 | * If a task dies, then it sets TASK_DEAD in tsk->state and calls |
55a101f8 ON |
2207 | * schedule one last time. The schedule call will never return, and |
2208 | * the scheduled task must drop that reference. | |
c394cc9f | 2209 | * The test for TASK_DEAD must occur while the runqueue locks are |
1da177e4 LT |
2210 | * still held, otherwise prev could be scheduled on another cpu, die |
2211 | * there before we look at prev->state, and then the reference would | |
2212 | * be dropped twice. | |
2213 | * Manfred Spraul <manfred@colorfullife.com> | |
2214 | */ | |
55a101f8 | 2215 | prev_state = prev->state; |
bf9fae9f | 2216 | vtime_task_switch(prev); |
4866cde0 | 2217 | finish_arch_switch(prev); |
a8d757ef | 2218 | perf_event_task_sched_in(prev, current); |
4866cde0 | 2219 | finish_lock_switch(rq, prev); |
01f23e16 | 2220 | finish_arch_post_lock_switch(); |
e8fa1362 | 2221 | |
e107be36 | 2222 | fire_sched_in_preempt_notifiers(current); |
1da177e4 LT |
2223 | if (mm) |
2224 | mmdrop(mm); | |
c394cc9f | 2225 | if (unlikely(prev_state == TASK_DEAD)) { |
e6c390f2 DF |
2226 | if (prev->sched_class->task_dead) |
2227 | prev->sched_class->task_dead(prev); | |
2228 | ||
c6fd91f0 | 2229 | /* |
2230 | * Remove function-return probe instances associated with this | |
2231 | * task and put them back on the free list. | |
9761eea8 | 2232 | */ |
c6fd91f0 | 2233 | kprobe_flush_task(prev); |
1da177e4 | 2234 | put_task_struct(prev); |
c6fd91f0 | 2235 | } |
99e5ada9 FW |
2236 | |
2237 | tick_nohz_task_switch(current); | |
1da177e4 LT |
2238 | } |
2239 | ||
3f029d3c GH |
2240 | #ifdef CONFIG_SMP |
2241 | ||
3f029d3c GH |
2242 | /* rq->lock is NOT held, but preemption is disabled */ |
2243 | static inline void post_schedule(struct rq *rq) | |
2244 | { | |
2245 | if (rq->post_schedule) { | |
2246 | unsigned long flags; | |
2247 | ||
05fa785c | 2248 | raw_spin_lock_irqsave(&rq->lock, flags); |
3f029d3c GH |
2249 | if (rq->curr->sched_class->post_schedule) |
2250 | rq->curr->sched_class->post_schedule(rq); | |
05fa785c | 2251 | raw_spin_unlock_irqrestore(&rq->lock, flags); |
3f029d3c GH |
2252 | |
2253 | rq->post_schedule = 0; | |
2254 | } | |
2255 | } | |
2256 | ||
2257 | #else | |
da19ab51 | 2258 | |
3f029d3c GH |
2259 | static inline void post_schedule(struct rq *rq) |
2260 | { | |
1da177e4 LT |
2261 | } |
2262 | ||
3f029d3c GH |
2263 | #endif |
2264 | ||
1da177e4 LT |
2265 | /** |
2266 | * schedule_tail - first thing a freshly forked thread must call. | |
2267 | * @prev: the thread we just switched away from. | |
2268 | */ | |
722a9f92 | 2269 | asmlinkage __visible void schedule_tail(struct task_struct *prev) |
1da177e4 LT |
2270 | __releases(rq->lock) |
2271 | { | |
70b97a7f IM |
2272 | struct rq *rq = this_rq(); |
2273 | ||
4866cde0 | 2274 | finish_task_switch(rq, prev); |
da19ab51 | 2275 | |
3f029d3c GH |
2276 | /* |
2277 | * FIXME: do we need to worry about rq being invalidated by the | |
2278 | * task_switch? | |
2279 | */ | |
2280 | post_schedule(rq); | |
70b97a7f | 2281 | |
4866cde0 NP |
2282 | #ifdef __ARCH_WANT_UNLOCKED_CTXSW |
2283 | /* In this case, finish_task_switch does not reenable preemption */ | |
2284 | preempt_enable(); | |
2285 | #endif | |
1da177e4 | 2286 | if (current->set_child_tid) |
b488893a | 2287 | put_user(task_pid_vnr(current), current->set_child_tid); |
1da177e4 LT |
2288 | } |
2289 | ||
2290 | /* | |
2291 | * context_switch - switch to the new MM and the new | |
2292 | * thread's register state. | |
2293 | */ | |
dd41f596 | 2294 | static inline void |
70b97a7f | 2295 | context_switch(struct rq *rq, struct task_struct *prev, |
36c8b586 | 2296 | struct task_struct *next) |
1da177e4 | 2297 | { |
dd41f596 | 2298 | struct mm_struct *mm, *oldmm; |
1da177e4 | 2299 | |
e107be36 | 2300 | prepare_task_switch(rq, prev, next); |
fe4b04fa | 2301 | |
dd41f596 IM |
2302 | mm = next->mm; |
2303 | oldmm = prev->active_mm; | |
9226d125 ZA |
2304 | /* |
2305 | * For paravirt, this is coupled with an exit in switch_to to | |
2306 | * combine the page table reload and the switch backend into | |
2307 | * one hypercall. | |
2308 | */ | |
224101ed | 2309 | arch_start_context_switch(prev); |
9226d125 | 2310 | |
31915ab4 | 2311 | if (!mm) { |
1da177e4 LT |
2312 | next->active_mm = oldmm; |
2313 | atomic_inc(&oldmm->mm_count); | |
2314 | enter_lazy_tlb(oldmm, next); | |
2315 | } else | |
2316 | switch_mm(oldmm, mm, next); | |
2317 | ||
31915ab4 | 2318 | if (!prev->mm) { |
1da177e4 | 2319 | prev->active_mm = NULL; |
1da177e4 LT |
2320 | rq->prev_mm = oldmm; |
2321 | } | |
3a5f5e48 IM |
2322 | /* |
2323 | * Since the runqueue lock will be released by the next | |
2324 | * task (which is an invalid locking op but in the case | |
2325 | * of the scheduler it's an obvious special-case), so we | |
2326 | * do an early lockdep release here: | |
2327 | */ | |
2328 | #ifndef __ARCH_WANT_UNLOCKED_CTXSW | |
8a25d5de | 2329 | spin_release(&rq->lock.dep_map, 1, _THIS_IP_); |
3a5f5e48 | 2330 | #endif |
1da177e4 | 2331 | |
91d1aa43 | 2332 | context_tracking_task_switch(prev, next); |
1da177e4 LT |
2333 | /* Here we just switch the register state and the stack. */ |
2334 | switch_to(prev, next, prev); | |
2335 | ||
dd41f596 IM |
2336 | barrier(); |
2337 | /* | |
2338 | * this_rq must be evaluated again because prev may have moved | |
2339 | * CPUs since it called schedule(), thus the 'rq' on its stack | |
2340 | * frame will be invalid. | |
2341 | */ | |
2342 | finish_task_switch(this_rq(), prev); | |
1da177e4 LT |
2343 | } |
2344 | ||
2345 | /* | |
1c3e8264 | 2346 | * nr_running and nr_context_switches: |
1da177e4 LT |
2347 | * |
2348 | * externally visible scheduler statistics: current number of runnable | |
1c3e8264 | 2349 | * threads, total number of context switches performed since bootup. |
1da177e4 LT |
2350 | */ |
2351 | unsigned long nr_running(void) | |
2352 | { | |
2353 | unsigned long i, sum = 0; | |
2354 | ||
2355 | for_each_online_cpu(i) | |
2356 | sum += cpu_rq(i)->nr_running; | |
2357 | ||
2358 | return sum; | |
f711f609 | 2359 | } |
1da177e4 | 2360 | |
1da177e4 | 2361 | unsigned long long nr_context_switches(void) |
46cb4b7c | 2362 | { |
cc94abfc SR |
2363 | int i; |
2364 | unsigned long long sum = 0; | |
46cb4b7c | 2365 | |
0a945022 | 2366 | for_each_possible_cpu(i) |
1da177e4 | 2367 | sum += cpu_rq(i)->nr_switches; |
46cb4b7c | 2368 | |
1da177e4 LT |
2369 | return sum; |
2370 | } | |
483b4ee6 | 2371 | |
1da177e4 LT |
2372 | unsigned long nr_iowait(void) |
2373 | { | |
2374 | unsigned long i, sum = 0; | |
483b4ee6 | 2375 | |
0a945022 | 2376 | for_each_possible_cpu(i) |
1da177e4 | 2377 | sum += atomic_read(&cpu_rq(i)->nr_iowait); |
46cb4b7c | 2378 | |
1da177e4 LT |
2379 | return sum; |
2380 | } | |
483b4ee6 | 2381 | |
8c215bd3 | 2382 | unsigned long nr_iowait_cpu(int cpu) |
69d25870 | 2383 | { |
8c215bd3 | 2384 | struct rq *this = cpu_rq(cpu); |
69d25870 AV |
2385 | return atomic_read(&this->nr_iowait); |
2386 | } | |
46cb4b7c | 2387 | |
dd41f596 | 2388 | #ifdef CONFIG_SMP |
8a0be9ef | 2389 | |
46cb4b7c | 2390 | /* |
38022906 PZ |
2391 | * sched_exec - execve() is a valuable balancing opportunity, because at |
2392 | * this point the task has the smallest effective memory and cache footprint. | |
46cb4b7c | 2393 | */ |
38022906 | 2394 | void sched_exec(void) |
46cb4b7c | 2395 | { |
38022906 | 2396 | struct task_struct *p = current; |
1da177e4 | 2397 | unsigned long flags; |
0017d735 | 2398 | int dest_cpu; |
46cb4b7c | 2399 | |
8f42ced9 | 2400 | raw_spin_lock_irqsave(&p->pi_lock, flags); |
ac66f547 | 2401 | dest_cpu = p->sched_class->select_task_rq(p, task_cpu(p), SD_BALANCE_EXEC, 0); |
0017d735 PZ |
2402 | if (dest_cpu == smp_processor_id()) |
2403 | goto unlock; | |
38022906 | 2404 | |
8f42ced9 | 2405 | if (likely(cpu_active(dest_cpu))) { |
969c7921 | 2406 | struct migration_arg arg = { p, dest_cpu }; |
46cb4b7c | 2407 | |
8f42ced9 PZ |
2408 | raw_spin_unlock_irqrestore(&p->pi_lock, flags); |
2409 | stop_one_cpu(task_cpu(p), migration_cpu_stop, &arg); | |
1da177e4 LT |
2410 | return; |
2411 | } | |
0017d735 | 2412 | unlock: |
8f42ced9 | 2413 | raw_spin_unlock_irqrestore(&p->pi_lock, flags); |
1da177e4 | 2414 | } |
dd41f596 | 2415 | |
1da177e4 LT |
2416 | #endif |
2417 | ||
1da177e4 | 2418 | DEFINE_PER_CPU(struct kernel_stat, kstat); |
3292beb3 | 2419 | DEFINE_PER_CPU(struct kernel_cpustat, kernel_cpustat); |
1da177e4 LT |
2420 | |
2421 | EXPORT_PER_CPU_SYMBOL(kstat); | |
3292beb3 | 2422 | EXPORT_PER_CPU_SYMBOL(kernel_cpustat); |
1da177e4 LT |
2423 | |
2424 | /* | |
c5f8d995 | 2425 | * Return any ns on the sched_clock that have not yet been accounted in |
f06febc9 | 2426 | * @p in case that task is currently running. |
c5f8d995 HS |
2427 | * |
2428 | * Called with task_rq_lock() held on @rq. | |
1da177e4 | 2429 | */ |
c5f8d995 HS |
2430 | static u64 do_task_delta_exec(struct task_struct *p, struct rq *rq) |
2431 | { | |
2432 | u64 ns = 0; | |
2433 | ||
2434 | if (task_current(rq, p)) { | |
2435 | update_rq_clock(rq); | |
78becc27 | 2436 | ns = rq_clock_task(rq) - p->se.exec_start; |
c5f8d995 HS |
2437 | if ((s64)ns < 0) |
2438 | ns = 0; | |
2439 | } | |
2440 | ||
2441 | return ns; | |
2442 | } | |
2443 | ||
bb34d92f | 2444 | unsigned long long task_delta_exec(struct task_struct *p) |
1da177e4 | 2445 | { |
1da177e4 | 2446 | unsigned long flags; |
41b86e9c | 2447 | struct rq *rq; |
bb34d92f | 2448 | u64 ns = 0; |
48f24c4d | 2449 | |
41b86e9c | 2450 | rq = task_rq_lock(p, &flags); |
c5f8d995 | 2451 | ns = do_task_delta_exec(p, rq); |
0122ec5b | 2452 | task_rq_unlock(rq, p, &flags); |
1508487e | 2453 | |
c5f8d995 HS |
2454 | return ns; |
2455 | } | |
f06febc9 | 2456 | |
c5f8d995 HS |
2457 | /* |
2458 | * Return accounted runtime for the task. | |
2459 | * In case the task is currently running, return the runtime plus current's | |
2460 | * pending runtime that have not been accounted yet. | |
2461 | */ | |
2462 | unsigned long long task_sched_runtime(struct task_struct *p) | |
2463 | { | |
2464 | unsigned long flags; | |
2465 | struct rq *rq; | |
2466 | u64 ns = 0; | |
2467 | ||
911b2898 PZ |
2468 | #if defined(CONFIG_64BIT) && defined(CONFIG_SMP) |
2469 | /* | |
2470 | * 64-bit doesn't need locks to atomically read a 64bit value. | |
2471 | * So we have a optimization chance when the task's delta_exec is 0. | |
2472 | * Reading ->on_cpu is racy, but this is ok. | |
2473 | * | |
2474 | * If we race with it leaving cpu, we'll take a lock. So we're correct. | |
2475 | * If we race with it entering cpu, unaccounted time is 0. This is | |
2476 | * indistinguishable from the read occurring a few cycles earlier. | |
2477 | */ | |
2478 | if (!p->on_cpu) | |
2479 | return p->se.sum_exec_runtime; | |
2480 | #endif | |
2481 | ||
c5f8d995 HS |
2482 | rq = task_rq_lock(p, &flags); |
2483 | ns = p->se.sum_exec_runtime + do_task_delta_exec(p, rq); | |
0122ec5b | 2484 | task_rq_unlock(rq, p, &flags); |
c5f8d995 HS |
2485 | |
2486 | return ns; | |
2487 | } | |
48f24c4d | 2488 | |
7835b98b CL |
2489 | /* |
2490 | * This function gets called by the timer code, with HZ frequency. | |
2491 | * We call it with interrupts disabled. | |
7835b98b CL |
2492 | */ |
2493 | void scheduler_tick(void) | |
2494 | { | |
7835b98b CL |
2495 | int cpu = smp_processor_id(); |
2496 | struct rq *rq = cpu_rq(cpu); | |
dd41f596 | 2497 | struct task_struct *curr = rq->curr; |
3e51f33f PZ |
2498 | |
2499 | sched_clock_tick(); | |
dd41f596 | 2500 | |
05fa785c | 2501 | raw_spin_lock(&rq->lock); |
3e51f33f | 2502 | update_rq_clock(rq); |
fa85ae24 | 2503 | curr->sched_class->task_tick(rq, curr, 0); |
83dfd523 | 2504 | update_cpu_load_active(rq); |
05fa785c | 2505 | raw_spin_unlock(&rq->lock); |
7835b98b | 2506 | |
e9d2b064 | 2507 | perf_event_task_tick(); |
e220d2dc | 2508 | |
e418e1c2 | 2509 | #ifdef CONFIG_SMP |
6eb57e0d | 2510 | rq->idle_balance = idle_cpu(cpu); |
7caff66f | 2511 | trigger_load_balance(rq); |
e418e1c2 | 2512 | #endif |
265f22a9 | 2513 | rq_last_tick_reset(rq); |
1da177e4 LT |
2514 | } |
2515 | ||
265f22a9 FW |
2516 | #ifdef CONFIG_NO_HZ_FULL |
2517 | /** | |
2518 | * scheduler_tick_max_deferment | |
2519 | * | |
2520 | * Keep at least one tick per second when a single | |
2521 | * active task is running because the scheduler doesn't | |
2522 | * yet completely support full dynticks environment. | |
2523 | * | |
2524 | * This makes sure that uptime, CFS vruntime, load | |
2525 | * balancing, etc... continue to move forward, even | |
2526 | * with a very low granularity. | |
e69f6186 YB |
2527 | * |
2528 | * Return: Maximum deferment in nanoseconds. | |
265f22a9 FW |
2529 | */ |
2530 | u64 scheduler_tick_max_deferment(void) | |
2531 | { | |
2532 | struct rq *rq = this_rq(); | |
2533 | unsigned long next, now = ACCESS_ONCE(jiffies); | |
2534 | ||
2535 | next = rq->last_sched_tick + HZ; | |
2536 | ||
2537 | if (time_before_eq(next, now)) | |
2538 | return 0; | |
2539 | ||
8fe8ff09 | 2540 | return jiffies_to_nsecs(next - now); |
1da177e4 | 2541 | } |
265f22a9 | 2542 | #endif |
1da177e4 | 2543 | |
132380a0 | 2544 | notrace unsigned long get_parent_ip(unsigned long addr) |
6cd8a4bb SR |
2545 | { |
2546 | if (in_lock_functions(addr)) { | |
2547 | addr = CALLER_ADDR2; | |
2548 | if (in_lock_functions(addr)) | |
2549 | addr = CALLER_ADDR3; | |
2550 | } | |
2551 | return addr; | |
2552 | } | |
1da177e4 | 2553 | |
7e49fcce SR |
2554 | #if defined(CONFIG_PREEMPT) && (defined(CONFIG_DEBUG_PREEMPT) || \ |
2555 | defined(CONFIG_PREEMPT_TRACER)) | |
2556 | ||
edafe3a5 | 2557 | void preempt_count_add(int val) |
1da177e4 | 2558 | { |
6cd8a4bb | 2559 | #ifdef CONFIG_DEBUG_PREEMPT |
1da177e4 LT |
2560 | /* |
2561 | * Underflow? | |
2562 | */ | |
9a11b49a IM |
2563 | if (DEBUG_LOCKS_WARN_ON((preempt_count() < 0))) |
2564 | return; | |
6cd8a4bb | 2565 | #endif |
bdb43806 | 2566 | __preempt_count_add(val); |
6cd8a4bb | 2567 | #ifdef CONFIG_DEBUG_PREEMPT |
1da177e4 LT |
2568 | /* |
2569 | * Spinlock count overflowing soon? | |
2570 | */ | |
33859f7f MOS |
2571 | DEBUG_LOCKS_WARN_ON((preempt_count() & PREEMPT_MASK) >= |
2572 | PREEMPT_MASK - 10); | |
6cd8a4bb | 2573 | #endif |
8f47b187 TG |
2574 | if (preempt_count() == val) { |
2575 | unsigned long ip = get_parent_ip(CALLER_ADDR1); | |
2576 | #ifdef CONFIG_DEBUG_PREEMPT | |
2577 | current->preempt_disable_ip = ip; | |
2578 | #endif | |
2579 | trace_preempt_off(CALLER_ADDR0, ip); | |
2580 | } | |
1da177e4 | 2581 | } |
bdb43806 | 2582 | EXPORT_SYMBOL(preempt_count_add); |
edafe3a5 | 2583 | NOKPROBE_SYMBOL(preempt_count_add); |
1da177e4 | 2584 | |
edafe3a5 | 2585 | void preempt_count_sub(int val) |
1da177e4 | 2586 | { |
6cd8a4bb | 2587 | #ifdef CONFIG_DEBUG_PREEMPT |
1da177e4 LT |
2588 | /* |
2589 | * Underflow? | |
2590 | */ | |
01e3eb82 | 2591 | if (DEBUG_LOCKS_WARN_ON(val > preempt_count())) |
9a11b49a | 2592 | return; |
1da177e4 LT |
2593 | /* |
2594 | * Is the spinlock portion underflowing? | |
2595 | */ | |
9a11b49a IM |
2596 | if (DEBUG_LOCKS_WARN_ON((val < PREEMPT_MASK) && |
2597 | !(preempt_count() & PREEMPT_MASK))) | |
2598 | return; | |
6cd8a4bb | 2599 | #endif |
9a11b49a | 2600 | |
6cd8a4bb SR |
2601 | if (preempt_count() == val) |
2602 | trace_preempt_on(CALLER_ADDR0, get_parent_ip(CALLER_ADDR1)); | |
bdb43806 | 2603 | __preempt_count_sub(val); |
1da177e4 | 2604 | } |
bdb43806 | 2605 | EXPORT_SYMBOL(preempt_count_sub); |
edafe3a5 | 2606 | NOKPROBE_SYMBOL(preempt_count_sub); |
1da177e4 LT |
2607 | |
2608 | #endif | |
2609 | ||
2610 | /* | |
dd41f596 | 2611 | * Print scheduling while atomic bug: |
1da177e4 | 2612 | */ |
dd41f596 | 2613 | static noinline void __schedule_bug(struct task_struct *prev) |
1da177e4 | 2614 | { |
664dfa65 DJ |
2615 | if (oops_in_progress) |
2616 | return; | |
2617 | ||
3df0fc5b PZ |
2618 | printk(KERN_ERR "BUG: scheduling while atomic: %s/%d/0x%08x\n", |
2619 | prev->comm, prev->pid, preempt_count()); | |
838225b4 | 2620 | |
dd41f596 | 2621 | debug_show_held_locks(prev); |
e21f5b15 | 2622 | print_modules(); |
dd41f596 IM |
2623 | if (irqs_disabled()) |
2624 | print_irqtrace_events(prev); | |
8f47b187 TG |
2625 | #ifdef CONFIG_DEBUG_PREEMPT |
2626 | if (in_atomic_preempt_off()) { | |
2627 | pr_err("Preemption disabled at:"); | |
2628 | print_ip_sym(current->preempt_disable_ip); | |
2629 | pr_cont("\n"); | |
2630 | } | |
2631 | #endif | |
6135fc1e | 2632 | dump_stack(); |
373d4d09 | 2633 | add_taint(TAINT_WARN, LOCKDEP_STILL_OK); |
dd41f596 | 2634 | } |
1da177e4 | 2635 | |
dd41f596 IM |
2636 | /* |
2637 | * Various schedule()-time debugging checks and statistics: | |
2638 | */ | |
2639 | static inline void schedule_debug(struct task_struct *prev) | |
2640 | { | |
1da177e4 | 2641 | /* |
41a2d6cf | 2642 | * Test if we are atomic. Since do_exit() needs to call into |
192301e7 ON |
2643 | * schedule() atomically, we ignore that path. Otherwise whine |
2644 | * if we are scheduling when we should not. | |
1da177e4 | 2645 | */ |
192301e7 | 2646 | if (unlikely(in_atomic_preempt_off() && prev->state != TASK_DEAD)) |
dd41f596 | 2647 | __schedule_bug(prev); |
b3fbab05 | 2648 | rcu_sleep_check(); |
dd41f596 | 2649 | |
1da177e4 LT |
2650 | profile_hit(SCHED_PROFILING, __builtin_return_address(0)); |
2651 | ||
2d72376b | 2652 | schedstat_inc(this_rq(), sched_count); |
dd41f596 IM |
2653 | } |
2654 | ||
2655 | /* | |
2656 | * Pick up the highest-prio task: | |
2657 | */ | |
2658 | static inline struct task_struct * | |
606dba2e | 2659 | pick_next_task(struct rq *rq, struct task_struct *prev) |
dd41f596 | 2660 | { |
37e117c0 | 2661 | const struct sched_class *class = &fair_sched_class; |
dd41f596 | 2662 | struct task_struct *p; |
1da177e4 LT |
2663 | |
2664 | /* | |
dd41f596 IM |
2665 | * Optimization: we know that if all tasks are in |
2666 | * the fair class we can call that function directly: | |
1da177e4 | 2667 | */ |
37e117c0 | 2668 | if (likely(prev->sched_class == class && |
38033c37 | 2669 | rq->nr_running == rq->cfs.h_nr_running)) { |
606dba2e | 2670 | p = fair_sched_class.pick_next_task(rq, prev); |
6ccdc84b PZ |
2671 | if (unlikely(p == RETRY_TASK)) |
2672 | goto again; | |
2673 | ||
2674 | /* assumes fair_sched_class->next == idle_sched_class */ | |
2675 | if (unlikely(!p)) | |
2676 | p = idle_sched_class.pick_next_task(rq, prev); | |
2677 | ||
2678 | return p; | |
1da177e4 LT |
2679 | } |
2680 | ||
37e117c0 | 2681 | again: |
34f971f6 | 2682 | for_each_class(class) { |
606dba2e | 2683 | p = class->pick_next_task(rq, prev); |
37e117c0 PZ |
2684 | if (p) { |
2685 | if (unlikely(p == RETRY_TASK)) | |
2686 | goto again; | |
dd41f596 | 2687 | return p; |
37e117c0 | 2688 | } |
dd41f596 | 2689 | } |
34f971f6 PZ |
2690 | |
2691 | BUG(); /* the idle class will always have a runnable task */ | |
dd41f596 | 2692 | } |
1da177e4 | 2693 | |
dd41f596 | 2694 | /* |
c259e01a | 2695 | * __schedule() is the main scheduler function. |
edde96ea PE |
2696 | * |
2697 | * The main means of driving the scheduler and thus entering this function are: | |
2698 | * | |
2699 | * 1. Explicit blocking: mutex, semaphore, waitqueue, etc. | |
2700 | * | |
2701 | * 2. TIF_NEED_RESCHED flag is checked on interrupt and userspace return | |
2702 | * paths. For example, see arch/x86/entry_64.S. | |
2703 | * | |
2704 | * To drive preemption between tasks, the scheduler sets the flag in timer | |
2705 | * interrupt handler scheduler_tick(). | |
2706 | * | |
2707 | * 3. Wakeups don't really cause entry into schedule(). They add a | |
2708 | * task to the run-queue and that's it. | |
2709 | * | |
2710 | * Now, if the new task added to the run-queue preempts the current | |
2711 | * task, then the wakeup sets TIF_NEED_RESCHED and schedule() gets | |
2712 | * called on the nearest possible occasion: | |
2713 | * | |
2714 | * - If the kernel is preemptible (CONFIG_PREEMPT=y): | |
2715 | * | |
2716 | * - in syscall or exception context, at the next outmost | |
2717 | * preempt_enable(). (this might be as soon as the wake_up()'s | |
2718 | * spin_unlock()!) | |
2719 | * | |
2720 | * - in IRQ context, return from interrupt-handler to | |
2721 | * preemptible context | |
2722 | * | |
2723 | * - If the kernel is not preemptible (CONFIG_PREEMPT is not set) | |
2724 | * then at the next: | |
2725 | * | |
2726 | * - cond_resched() call | |
2727 | * - explicit schedule() call | |
2728 | * - return from syscall or exception to user-space | |
2729 | * - return from interrupt-handler to user-space | |
dd41f596 | 2730 | */ |
c259e01a | 2731 | static void __sched __schedule(void) |
dd41f596 IM |
2732 | { |
2733 | struct task_struct *prev, *next; | |
67ca7bde | 2734 | unsigned long *switch_count; |
dd41f596 | 2735 | struct rq *rq; |
31656519 | 2736 | int cpu; |
dd41f596 | 2737 | |
ff743345 PZ |
2738 | need_resched: |
2739 | preempt_disable(); | |
dd41f596 IM |
2740 | cpu = smp_processor_id(); |
2741 | rq = cpu_rq(cpu); | |
25502a6c | 2742 | rcu_note_context_switch(cpu); |
dd41f596 | 2743 | prev = rq->curr; |
dd41f596 | 2744 | |
dd41f596 | 2745 | schedule_debug(prev); |
1da177e4 | 2746 | |
31656519 | 2747 | if (sched_feat(HRTICK)) |
f333fdc9 | 2748 | hrtick_clear(rq); |
8f4d37ec | 2749 | |
e0acd0a6 ON |
2750 | /* |
2751 | * Make sure that signal_pending_state()->signal_pending() below | |
2752 | * can't be reordered with __set_current_state(TASK_INTERRUPTIBLE) | |
2753 | * done by the caller to avoid the race with signal_wake_up(). | |
2754 | */ | |
2755 | smp_mb__before_spinlock(); | |
05fa785c | 2756 | raw_spin_lock_irq(&rq->lock); |
1da177e4 | 2757 | |
246d86b5 | 2758 | switch_count = &prev->nivcsw; |
1da177e4 | 2759 | if (prev->state && !(preempt_count() & PREEMPT_ACTIVE)) { |
21aa9af0 | 2760 | if (unlikely(signal_pending_state(prev->state, prev))) { |
1da177e4 | 2761 | prev->state = TASK_RUNNING; |
21aa9af0 | 2762 | } else { |
2acca55e PZ |
2763 | deactivate_task(rq, prev, DEQUEUE_SLEEP); |
2764 | prev->on_rq = 0; | |
2765 | ||
21aa9af0 | 2766 | /* |
2acca55e PZ |
2767 | * If a worker went to sleep, notify and ask workqueue |
2768 | * whether it wants to wake up a task to maintain | |
2769 | * concurrency. | |
21aa9af0 TH |
2770 | */ |
2771 | if (prev->flags & PF_WQ_WORKER) { | |
2772 | struct task_struct *to_wakeup; | |
2773 | ||
2774 | to_wakeup = wq_worker_sleeping(prev, cpu); | |
2775 | if (to_wakeup) | |
2776 | try_to_wake_up_local(to_wakeup); | |
2777 | } | |
21aa9af0 | 2778 | } |
dd41f596 | 2779 | switch_count = &prev->nvcsw; |
1da177e4 LT |
2780 | } |
2781 | ||
606dba2e PZ |
2782 | if (prev->on_rq || rq->skip_clock_update < 0) |
2783 | update_rq_clock(rq); | |
2784 | ||
2785 | next = pick_next_task(rq, prev); | |
f26f9aff | 2786 | clear_tsk_need_resched(prev); |
f27dde8d | 2787 | clear_preempt_need_resched(); |
f26f9aff | 2788 | rq->skip_clock_update = 0; |
1da177e4 | 2789 | |
1da177e4 | 2790 | if (likely(prev != next)) { |
1da177e4 LT |
2791 | rq->nr_switches++; |
2792 | rq->curr = next; | |
2793 | ++*switch_count; | |
2794 | ||
dd41f596 | 2795 | context_switch(rq, prev, next); /* unlocks the rq */ |
8f4d37ec | 2796 | /* |
246d86b5 ON |
2797 | * The context switch have flipped the stack from under us |
2798 | * and restored the local variables which were saved when | |
2799 | * this task called schedule() in the past. prev == current | |
2800 | * is still correct, but it can be moved to another cpu/rq. | |
8f4d37ec PZ |
2801 | */ |
2802 | cpu = smp_processor_id(); | |
2803 | rq = cpu_rq(cpu); | |
1da177e4 | 2804 | } else |
05fa785c | 2805 | raw_spin_unlock_irq(&rq->lock); |
1da177e4 | 2806 | |
3f029d3c | 2807 | post_schedule(rq); |
1da177e4 | 2808 | |
ba74c144 | 2809 | sched_preempt_enable_no_resched(); |
ff743345 | 2810 | if (need_resched()) |
1da177e4 LT |
2811 | goto need_resched; |
2812 | } | |
c259e01a | 2813 | |
9c40cef2 TG |
2814 | static inline void sched_submit_work(struct task_struct *tsk) |
2815 | { | |
3c7d5184 | 2816 | if (!tsk->state || tsk_is_pi_blocked(tsk)) |
9c40cef2 TG |
2817 | return; |
2818 | /* | |
2819 | * If we are going to sleep and we have plugged IO queued, | |
2820 | * make sure to submit it to avoid deadlocks. | |
2821 | */ | |
2822 | if (blk_needs_flush_plug(tsk)) | |
2823 | blk_schedule_flush_plug(tsk); | |
2824 | } | |
2825 | ||
722a9f92 | 2826 | asmlinkage __visible void __sched schedule(void) |
c259e01a | 2827 | { |
9c40cef2 TG |
2828 | struct task_struct *tsk = current; |
2829 | ||
2830 | sched_submit_work(tsk); | |
c259e01a TG |
2831 | __schedule(); |
2832 | } | |
1da177e4 LT |
2833 | EXPORT_SYMBOL(schedule); |
2834 | ||
91d1aa43 | 2835 | #ifdef CONFIG_CONTEXT_TRACKING |
722a9f92 | 2836 | asmlinkage __visible void __sched schedule_user(void) |
20ab65e3 FW |
2837 | { |
2838 | /* | |
2839 | * If we come here after a random call to set_need_resched(), | |
2840 | * or we have been woken up remotely but the IPI has not yet arrived, | |
2841 | * we haven't yet exited the RCU idle mode. Do it here manually until | |
2842 | * we find a better solution. | |
2843 | */ | |
91d1aa43 | 2844 | user_exit(); |
20ab65e3 | 2845 | schedule(); |
91d1aa43 | 2846 | user_enter(); |
20ab65e3 FW |
2847 | } |
2848 | #endif | |
2849 | ||
c5491ea7 TG |
2850 | /** |
2851 | * schedule_preempt_disabled - called with preemption disabled | |
2852 | * | |
2853 | * Returns with preemption disabled. Note: preempt_count must be 1 | |
2854 | */ | |
2855 | void __sched schedule_preempt_disabled(void) | |
2856 | { | |
ba74c144 | 2857 | sched_preempt_enable_no_resched(); |
c5491ea7 TG |
2858 | schedule(); |
2859 | preempt_disable(); | |
2860 | } | |
2861 | ||
1da177e4 LT |
2862 | #ifdef CONFIG_PREEMPT |
2863 | /* | |
2ed6e34f | 2864 | * this is the entry point to schedule() from in-kernel preemption |
41a2d6cf | 2865 | * off of preempt_enable. Kernel preemptions off return from interrupt |
1da177e4 LT |
2866 | * occur there and call schedule directly. |
2867 | */ | |
722a9f92 | 2868 | asmlinkage __visible void __sched notrace preempt_schedule(void) |
1da177e4 | 2869 | { |
1da177e4 LT |
2870 | /* |
2871 | * If there is a non-zero preempt_count or interrupts are disabled, | |
41a2d6cf | 2872 | * we do not want to preempt the current task. Just return.. |
1da177e4 | 2873 | */ |
fbb00b56 | 2874 | if (likely(!preemptible())) |
1da177e4 LT |
2875 | return; |
2876 | ||
3a5c359a | 2877 | do { |
bdb43806 | 2878 | __preempt_count_add(PREEMPT_ACTIVE); |
c259e01a | 2879 | __schedule(); |
bdb43806 | 2880 | __preempt_count_sub(PREEMPT_ACTIVE); |
1da177e4 | 2881 | |
3a5c359a AK |
2882 | /* |
2883 | * Check again in case we missed a preemption opportunity | |
2884 | * between schedule and now. | |
2885 | */ | |
2886 | barrier(); | |
5ed0cec0 | 2887 | } while (need_resched()); |
1da177e4 | 2888 | } |
376e2424 | 2889 | NOKPROBE_SYMBOL(preempt_schedule); |
1da177e4 | 2890 | EXPORT_SYMBOL(preempt_schedule); |
32e475d7 | 2891 | #endif /* CONFIG_PREEMPT */ |
1da177e4 LT |
2892 | |
2893 | /* | |
2ed6e34f | 2894 | * this is the entry point to schedule() from kernel preemption |
1da177e4 LT |
2895 | * off of irq context. |
2896 | * Note, that this is called and return with irqs disabled. This will | |
2897 | * protect us against recursive calling from irq. | |
2898 | */ | |
722a9f92 | 2899 | asmlinkage __visible void __sched preempt_schedule_irq(void) |
1da177e4 | 2900 | { |
b22366cd | 2901 | enum ctx_state prev_state; |
6478d880 | 2902 | |
2ed6e34f | 2903 | /* Catch callers which need to be fixed */ |
f27dde8d | 2904 | BUG_ON(preempt_count() || !irqs_disabled()); |
1da177e4 | 2905 | |
b22366cd FW |
2906 | prev_state = exception_enter(); |
2907 | ||
3a5c359a | 2908 | do { |
bdb43806 | 2909 | __preempt_count_add(PREEMPT_ACTIVE); |
3a5c359a | 2910 | local_irq_enable(); |
c259e01a | 2911 | __schedule(); |
3a5c359a | 2912 | local_irq_disable(); |
bdb43806 | 2913 | __preempt_count_sub(PREEMPT_ACTIVE); |
1da177e4 | 2914 | |
3a5c359a AK |
2915 | /* |
2916 | * Check again in case we missed a preemption opportunity | |
2917 | * between schedule and now. | |
2918 | */ | |
2919 | barrier(); | |
5ed0cec0 | 2920 | } while (need_resched()); |
b22366cd FW |
2921 | |
2922 | exception_exit(prev_state); | |
1da177e4 LT |
2923 | } |
2924 | ||
63859d4f | 2925 | int default_wake_function(wait_queue_t *curr, unsigned mode, int wake_flags, |
95cdf3b7 | 2926 | void *key) |
1da177e4 | 2927 | { |
63859d4f | 2928 | return try_to_wake_up(curr->private, mode, wake_flags); |
1da177e4 | 2929 | } |
1da177e4 LT |
2930 | EXPORT_SYMBOL(default_wake_function); |
2931 | ||
b29739f9 IM |
2932 | #ifdef CONFIG_RT_MUTEXES |
2933 | ||
2934 | /* | |
2935 | * rt_mutex_setprio - set the current priority of a task | |
2936 | * @p: task | |
2937 | * @prio: prio value (kernel-internal form) | |
2938 | * | |
2939 | * This function changes the 'effective' priority of a task. It does | |
2940 | * not touch ->normal_prio like __setscheduler(). | |
2941 | * | |
c365c292 TG |
2942 | * Used by the rt_mutex code to implement priority inheritance |
2943 | * logic. Call site only calls if the priority of the task changed. | |
b29739f9 | 2944 | */ |
36c8b586 | 2945 | void rt_mutex_setprio(struct task_struct *p, int prio) |
b29739f9 | 2946 | { |
2d3d891d | 2947 | int oldprio, on_rq, running, enqueue_flag = 0; |
70b97a7f | 2948 | struct rq *rq; |
83ab0aa0 | 2949 | const struct sched_class *prev_class; |
b29739f9 | 2950 | |
aab03e05 | 2951 | BUG_ON(prio > MAX_PRIO); |
b29739f9 | 2952 | |
0122ec5b | 2953 | rq = __task_rq_lock(p); |
b29739f9 | 2954 | |
1c4dd99b TG |
2955 | /* |
2956 | * Idle task boosting is a nono in general. There is one | |
2957 | * exception, when PREEMPT_RT and NOHZ is active: | |
2958 | * | |
2959 | * The idle task calls get_next_timer_interrupt() and holds | |
2960 | * the timer wheel base->lock on the CPU and another CPU wants | |
2961 | * to access the timer (probably to cancel it). We can safely | |
2962 | * ignore the boosting request, as the idle CPU runs this code | |
2963 | * with interrupts disabled and will complete the lock | |
2964 | * protected section without being interrupted. So there is no | |
2965 | * real need to boost. | |
2966 | */ | |
2967 | if (unlikely(p == rq->idle)) { | |
2968 | WARN_ON(p != rq->curr); | |
2969 | WARN_ON(p->pi_blocked_on); | |
2970 | goto out_unlock; | |
2971 | } | |
2972 | ||
a8027073 | 2973 | trace_sched_pi_setprio(p, prio); |
2d3d891d | 2974 | p->pi_top_task = rt_mutex_get_top_task(p); |
d5f9f942 | 2975 | oldprio = p->prio; |
83ab0aa0 | 2976 | prev_class = p->sched_class; |
fd2f4419 | 2977 | on_rq = p->on_rq; |
051a1d1a | 2978 | running = task_current(rq, p); |
0e1f3483 | 2979 | if (on_rq) |
69be72c1 | 2980 | dequeue_task(rq, p, 0); |
0e1f3483 HS |
2981 | if (running) |
2982 | p->sched_class->put_prev_task(rq, p); | |
dd41f596 | 2983 | |
2d3d891d DF |
2984 | /* |
2985 | * Boosting condition are: | |
2986 | * 1. -rt task is running and holds mutex A | |
2987 | * --> -dl task blocks on mutex A | |
2988 | * | |
2989 | * 2. -dl task is running and holds mutex A | |
2990 | * --> -dl task blocks on mutex A and could preempt the | |
2991 | * running task | |
2992 | */ | |
2993 | if (dl_prio(prio)) { | |
2994 | if (!dl_prio(p->normal_prio) || (p->pi_top_task && | |
2995 | dl_entity_preempt(&p->pi_top_task->dl, &p->dl))) { | |
2996 | p->dl.dl_boosted = 1; | |
2997 | p->dl.dl_throttled = 0; | |
2998 | enqueue_flag = ENQUEUE_REPLENISH; | |
2999 | } else | |
3000 | p->dl.dl_boosted = 0; | |
aab03e05 | 3001 | p->sched_class = &dl_sched_class; |
2d3d891d DF |
3002 | } else if (rt_prio(prio)) { |
3003 | if (dl_prio(oldprio)) | |
3004 | p->dl.dl_boosted = 0; | |
3005 | if (oldprio < prio) | |
3006 | enqueue_flag = ENQUEUE_HEAD; | |
dd41f596 | 3007 | p->sched_class = &rt_sched_class; |
2d3d891d DF |
3008 | } else { |
3009 | if (dl_prio(oldprio)) | |
3010 | p->dl.dl_boosted = 0; | |
dd41f596 | 3011 | p->sched_class = &fair_sched_class; |
2d3d891d | 3012 | } |
dd41f596 | 3013 | |
b29739f9 IM |
3014 | p->prio = prio; |
3015 | ||
0e1f3483 HS |
3016 | if (running) |
3017 | p->sched_class->set_curr_task(rq); | |
da7a735e | 3018 | if (on_rq) |
2d3d891d | 3019 | enqueue_task(rq, p, enqueue_flag); |
cb469845 | 3020 | |
da7a735e | 3021 | check_class_changed(rq, p, prev_class, oldprio); |
1c4dd99b | 3022 | out_unlock: |
0122ec5b | 3023 | __task_rq_unlock(rq); |
b29739f9 | 3024 | } |
b29739f9 | 3025 | #endif |
d50dde5a | 3026 | |
36c8b586 | 3027 | void set_user_nice(struct task_struct *p, long nice) |
1da177e4 | 3028 | { |
dd41f596 | 3029 | int old_prio, delta, on_rq; |
1da177e4 | 3030 | unsigned long flags; |
70b97a7f | 3031 | struct rq *rq; |
1da177e4 | 3032 | |
75e45d51 | 3033 | if (task_nice(p) == nice || nice < MIN_NICE || nice > MAX_NICE) |
1da177e4 LT |
3034 | return; |
3035 | /* | |
3036 | * We have to be careful, if called from sys_setpriority(), | |
3037 | * the task might be in the middle of scheduling on another CPU. | |
3038 | */ | |
3039 | rq = task_rq_lock(p, &flags); | |
3040 | /* | |
3041 | * The RT priorities are set via sched_setscheduler(), but we still | |
3042 | * allow the 'normal' nice value to be set - but as expected | |
3043 | * it wont have any effect on scheduling until the task is | |
aab03e05 | 3044 | * SCHED_DEADLINE, SCHED_FIFO or SCHED_RR: |
1da177e4 | 3045 | */ |
aab03e05 | 3046 | if (task_has_dl_policy(p) || task_has_rt_policy(p)) { |
1da177e4 LT |
3047 | p->static_prio = NICE_TO_PRIO(nice); |
3048 | goto out_unlock; | |
3049 | } | |
fd2f4419 | 3050 | on_rq = p->on_rq; |
c09595f6 | 3051 | if (on_rq) |
69be72c1 | 3052 | dequeue_task(rq, p, 0); |
1da177e4 | 3053 | |
1da177e4 | 3054 | p->static_prio = NICE_TO_PRIO(nice); |
2dd73a4f | 3055 | set_load_weight(p); |
b29739f9 IM |
3056 | old_prio = p->prio; |
3057 | p->prio = effective_prio(p); | |
3058 | delta = p->prio - old_prio; | |
1da177e4 | 3059 | |
dd41f596 | 3060 | if (on_rq) { |
371fd7e7 | 3061 | enqueue_task(rq, p, 0); |
1da177e4 | 3062 | /* |
d5f9f942 AM |
3063 | * If the task increased its priority or is running and |
3064 | * lowered its priority, then reschedule its CPU: | |
1da177e4 | 3065 | */ |
d5f9f942 | 3066 | if (delta < 0 || (delta > 0 && task_running(rq, p))) |
1da177e4 LT |
3067 | resched_task(rq->curr); |
3068 | } | |
3069 | out_unlock: | |
0122ec5b | 3070 | task_rq_unlock(rq, p, &flags); |
1da177e4 | 3071 | } |
1da177e4 LT |
3072 | EXPORT_SYMBOL(set_user_nice); |
3073 | ||
e43379f1 MM |
3074 | /* |
3075 | * can_nice - check if a task can reduce its nice value | |
3076 | * @p: task | |
3077 | * @nice: nice value | |
3078 | */ | |
36c8b586 | 3079 | int can_nice(const struct task_struct *p, const int nice) |
e43379f1 | 3080 | { |
024f4747 | 3081 | /* convert nice value [19,-20] to rlimit style value [1,40] */ |
7aa2c016 | 3082 | int nice_rlim = nice_to_rlimit(nice); |
48f24c4d | 3083 | |
78d7d407 | 3084 | return (nice_rlim <= task_rlimit(p, RLIMIT_NICE) || |
e43379f1 MM |
3085 | capable(CAP_SYS_NICE)); |
3086 | } | |
3087 | ||
1da177e4 LT |
3088 | #ifdef __ARCH_WANT_SYS_NICE |
3089 | ||
3090 | /* | |
3091 | * sys_nice - change the priority of the current process. | |
3092 | * @increment: priority increment | |
3093 | * | |
3094 | * sys_setpriority is a more generic, but much slower function that | |
3095 | * does similar things. | |
3096 | */ | |
5add95d4 | 3097 | SYSCALL_DEFINE1(nice, int, increment) |
1da177e4 | 3098 | { |
48f24c4d | 3099 | long nice, retval; |
1da177e4 LT |
3100 | |
3101 | /* | |
3102 | * Setpriority might change our priority at the same moment. | |
3103 | * We don't have to worry. Conceptually one call occurs first | |
3104 | * and we have a single winner. | |
3105 | */ | |
a9467fa3 | 3106 | increment = clamp(increment, -NICE_WIDTH, NICE_WIDTH); |
d0ea0268 | 3107 | nice = task_nice(current) + increment; |
1da177e4 | 3108 | |
a9467fa3 | 3109 | nice = clamp_val(nice, MIN_NICE, MAX_NICE); |
e43379f1 MM |
3110 | if (increment < 0 && !can_nice(current, nice)) |
3111 | return -EPERM; | |
3112 | ||
1da177e4 LT |
3113 | retval = security_task_setnice(current, nice); |
3114 | if (retval) | |
3115 | return retval; | |
3116 | ||
3117 | set_user_nice(current, nice); | |
3118 | return 0; | |
3119 | } | |
3120 | ||
3121 | #endif | |
3122 | ||
3123 | /** | |
3124 | * task_prio - return the priority value of a given task. | |
3125 | * @p: the task in question. | |
3126 | * | |
e69f6186 | 3127 | * Return: The priority value as seen by users in /proc. |
1da177e4 LT |
3128 | * RT tasks are offset by -200. Normal tasks are centered |
3129 | * around 0, value goes from -16 to +15. | |
3130 | */ | |
36c8b586 | 3131 | int task_prio(const struct task_struct *p) |
1da177e4 LT |
3132 | { |
3133 | return p->prio - MAX_RT_PRIO; | |
3134 | } | |
3135 | ||
1da177e4 LT |
3136 | /** |
3137 | * idle_cpu - is a given cpu idle currently? | |
3138 | * @cpu: the processor in question. | |
e69f6186 YB |
3139 | * |
3140 | * Return: 1 if the CPU is currently idle. 0 otherwise. | |
1da177e4 LT |
3141 | */ |
3142 | int idle_cpu(int cpu) | |
3143 | { | |
908a3283 TG |
3144 | struct rq *rq = cpu_rq(cpu); |
3145 | ||
3146 | if (rq->curr != rq->idle) | |
3147 | return 0; | |
3148 | ||
3149 | if (rq->nr_running) | |
3150 | return 0; | |
3151 | ||
3152 | #ifdef CONFIG_SMP | |
3153 | if (!llist_empty(&rq->wake_list)) | |
3154 | return 0; | |
3155 | #endif | |
3156 | ||
3157 | return 1; | |
1da177e4 LT |
3158 | } |
3159 | ||
1da177e4 LT |
3160 | /** |
3161 | * idle_task - return the idle task for a given cpu. | |
3162 | * @cpu: the processor in question. | |
e69f6186 YB |
3163 | * |
3164 | * Return: The idle task for the cpu @cpu. | |
1da177e4 | 3165 | */ |
36c8b586 | 3166 | struct task_struct *idle_task(int cpu) |
1da177e4 LT |
3167 | { |
3168 | return cpu_rq(cpu)->idle; | |
3169 | } | |
3170 | ||
3171 | /** | |
3172 | * find_process_by_pid - find a process with a matching PID value. | |
3173 | * @pid: the pid in question. | |
e69f6186 YB |
3174 | * |
3175 | * The task of @pid, if found. %NULL otherwise. | |
1da177e4 | 3176 | */ |
a9957449 | 3177 | static struct task_struct *find_process_by_pid(pid_t pid) |
1da177e4 | 3178 | { |
228ebcbe | 3179 | return pid ? find_task_by_vpid(pid) : current; |
1da177e4 LT |
3180 | } |
3181 | ||
aab03e05 DF |
3182 | /* |
3183 | * This function initializes the sched_dl_entity of a newly becoming | |
3184 | * SCHED_DEADLINE task. | |
3185 | * | |
3186 | * Only the static values are considered here, the actual runtime and the | |
3187 | * absolute deadline will be properly calculated when the task is enqueued | |
3188 | * for the first time with its new policy. | |
3189 | */ | |
3190 | static void | |
3191 | __setparam_dl(struct task_struct *p, const struct sched_attr *attr) | |
3192 | { | |
3193 | struct sched_dl_entity *dl_se = &p->dl; | |
3194 | ||
3195 | init_dl_task_timer(dl_se); | |
3196 | dl_se->dl_runtime = attr->sched_runtime; | |
3197 | dl_se->dl_deadline = attr->sched_deadline; | |
755378a4 | 3198 | dl_se->dl_period = attr->sched_period ?: dl_se->dl_deadline; |
aab03e05 | 3199 | dl_se->flags = attr->sched_flags; |
332ac17e | 3200 | dl_se->dl_bw = to_ratio(dl_se->dl_period, dl_se->dl_runtime); |
aab03e05 DF |
3201 | dl_se->dl_throttled = 0; |
3202 | dl_se->dl_new = 1; | |
5bfd126e | 3203 | dl_se->dl_yielded = 0; |
aab03e05 DF |
3204 | } |
3205 | ||
c365c292 TG |
3206 | static void __setscheduler_params(struct task_struct *p, |
3207 | const struct sched_attr *attr) | |
1da177e4 | 3208 | { |
d50dde5a DF |
3209 | int policy = attr->sched_policy; |
3210 | ||
39fd8fd2 PZ |
3211 | if (policy == -1) /* setparam */ |
3212 | policy = p->policy; | |
3213 | ||
1da177e4 | 3214 | p->policy = policy; |
d50dde5a | 3215 | |
aab03e05 DF |
3216 | if (dl_policy(policy)) |
3217 | __setparam_dl(p, attr); | |
39fd8fd2 | 3218 | else if (fair_policy(policy)) |
d50dde5a DF |
3219 | p->static_prio = NICE_TO_PRIO(attr->sched_nice); |
3220 | ||
39fd8fd2 PZ |
3221 | /* |
3222 | * __sched_setscheduler() ensures attr->sched_priority == 0 when | |
3223 | * !rt_policy. Always setting this ensures that things like | |
3224 | * getparam()/getattr() don't report silly values for !rt tasks. | |
3225 | */ | |
3226 | p->rt_priority = attr->sched_priority; | |
383afd09 | 3227 | p->normal_prio = normal_prio(p); |
c365c292 TG |
3228 | set_load_weight(p); |
3229 | } | |
39fd8fd2 | 3230 | |
c365c292 TG |
3231 | /* Actually do priority change: must hold pi & rq lock. */ |
3232 | static void __setscheduler(struct rq *rq, struct task_struct *p, | |
3233 | const struct sched_attr *attr) | |
3234 | { | |
3235 | __setscheduler_params(p, attr); | |
d50dde5a | 3236 | |
383afd09 SR |
3237 | /* |
3238 | * If we get here, there was no pi waiters boosting the | |
3239 | * task. It is safe to use the normal prio. | |
3240 | */ | |
3241 | p->prio = normal_prio(p); | |
3242 | ||
aab03e05 DF |
3243 | if (dl_prio(p->prio)) |
3244 | p->sched_class = &dl_sched_class; | |
3245 | else if (rt_prio(p->prio)) | |
ffd44db5 PZ |
3246 | p->sched_class = &rt_sched_class; |
3247 | else | |
3248 | p->sched_class = &fair_sched_class; | |
1da177e4 | 3249 | } |
aab03e05 DF |
3250 | |
3251 | static void | |
3252 | __getparam_dl(struct task_struct *p, struct sched_attr *attr) | |
3253 | { | |
3254 | struct sched_dl_entity *dl_se = &p->dl; | |
3255 | ||
3256 | attr->sched_priority = p->rt_priority; | |
3257 | attr->sched_runtime = dl_se->dl_runtime; | |
3258 | attr->sched_deadline = dl_se->dl_deadline; | |
755378a4 | 3259 | attr->sched_period = dl_se->dl_period; |
aab03e05 DF |
3260 | attr->sched_flags = dl_se->flags; |
3261 | } | |
3262 | ||
3263 | /* | |
3264 | * This function validates the new parameters of a -deadline task. | |
3265 | * We ask for the deadline not being zero, and greater or equal | |
755378a4 | 3266 | * than the runtime, as well as the period of being zero or |
332ac17e | 3267 | * greater than deadline. Furthermore, we have to be sure that |
b0827819 JL |
3268 | * user parameters are above the internal resolution of 1us (we |
3269 | * check sched_runtime only since it is always the smaller one) and | |
3270 | * below 2^63 ns (we have to check both sched_deadline and | |
3271 | * sched_period, as the latter can be zero). | |
aab03e05 DF |
3272 | */ |
3273 | static bool | |
3274 | __checkparam_dl(const struct sched_attr *attr) | |
3275 | { | |
b0827819 JL |
3276 | /* deadline != 0 */ |
3277 | if (attr->sched_deadline == 0) | |
3278 | return false; | |
3279 | ||
3280 | /* | |
3281 | * Since we truncate DL_SCALE bits, make sure we're at least | |
3282 | * that big. | |
3283 | */ | |
3284 | if (attr->sched_runtime < (1ULL << DL_SCALE)) | |
3285 | return false; | |
3286 | ||
3287 | /* | |
3288 | * Since we use the MSB for wrap-around and sign issues, make | |
3289 | * sure it's not set (mind that period can be equal to zero). | |
3290 | */ | |
3291 | if (attr->sched_deadline & (1ULL << 63) || | |
3292 | attr->sched_period & (1ULL << 63)) | |
3293 | return false; | |
3294 | ||
3295 | /* runtime <= deadline <= period (if period != 0) */ | |
3296 | if ((attr->sched_period != 0 && | |
3297 | attr->sched_period < attr->sched_deadline) || | |
3298 | attr->sched_deadline < attr->sched_runtime) | |
3299 | return false; | |
3300 | ||
3301 | return true; | |
aab03e05 DF |
3302 | } |
3303 | ||
c69e8d9c DH |
3304 | /* |
3305 | * check the target process has a UID that matches the current process's | |
3306 | */ | |
3307 | static bool check_same_owner(struct task_struct *p) | |
3308 | { | |
3309 | const struct cred *cred = current_cred(), *pcred; | |
3310 | bool match; | |
3311 | ||
3312 | rcu_read_lock(); | |
3313 | pcred = __task_cred(p); | |
9c806aa0 EB |
3314 | match = (uid_eq(cred->euid, pcred->euid) || |
3315 | uid_eq(cred->euid, pcred->uid)); | |
c69e8d9c DH |
3316 | rcu_read_unlock(); |
3317 | return match; | |
3318 | } | |
3319 | ||
d50dde5a DF |
3320 | static int __sched_setscheduler(struct task_struct *p, |
3321 | const struct sched_attr *attr, | |
3322 | bool user) | |
1da177e4 | 3323 | { |
383afd09 SR |
3324 | int newprio = dl_policy(attr->sched_policy) ? MAX_DL_PRIO - 1 : |
3325 | MAX_RT_PRIO - 1 - attr->sched_priority; | |
83b699ed | 3326 | int retval, oldprio, oldpolicy = -1, on_rq, running; |
d50dde5a | 3327 | int policy = attr->sched_policy; |
1da177e4 | 3328 | unsigned long flags; |
83ab0aa0 | 3329 | const struct sched_class *prev_class; |
70b97a7f | 3330 | struct rq *rq; |
ca94c442 | 3331 | int reset_on_fork; |
1da177e4 | 3332 | |
66e5393a SR |
3333 | /* may grab non-irq protected spin_locks */ |
3334 | BUG_ON(in_interrupt()); | |
1da177e4 LT |
3335 | recheck: |
3336 | /* double check policy once rq lock held */ | |
ca94c442 LP |
3337 | if (policy < 0) { |
3338 | reset_on_fork = p->sched_reset_on_fork; | |
1da177e4 | 3339 | policy = oldpolicy = p->policy; |
ca94c442 | 3340 | } else { |
7479f3c9 | 3341 | reset_on_fork = !!(attr->sched_flags & SCHED_FLAG_RESET_ON_FORK); |
ca94c442 | 3342 | |
aab03e05 DF |
3343 | if (policy != SCHED_DEADLINE && |
3344 | policy != SCHED_FIFO && policy != SCHED_RR && | |
ca94c442 LP |
3345 | policy != SCHED_NORMAL && policy != SCHED_BATCH && |
3346 | policy != SCHED_IDLE) | |
3347 | return -EINVAL; | |
3348 | } | |
3349 | ||
7479f3c9 PZ |
3350 | if (attr->sched_flags & ~(SCHED_FLAG_RESET_ON_FORK)) |
3351 | return -EINVAL; | |
3352 | ||
1da177e4 LT |
3353 | /* |
3354 | * Valid priorities for SCHED_FIFO and SCHED_RR are | |
dd41f596 IM |
3355 | * 1..MAX_USER_RT_PRIO-1, valid priority for SCHED_NORMAL, |
3356 | * SCHED_BATCH and SCHED_IDLE is 0. | |
1da177e4 | 3357 | */ |
0bb040a4 | 3358 | if ((p->mm && attr->sched_priority > MAX_USER_RT_PRIO-1) || |
d50dde5a | 3359 | (!p->mm && attr->sched_priority > MAX_RT_PRIO-1)) |
1da177e4 | 3360 | return -EINVAL; |
aab03e05 DF |
3361 | if ((dl_policy(policy) && !__checkparam_dl(attr)) || |
3362 | (rt_policy(policy) != (attr->sched_priority != 0))) | |
1da177e4 LT |
3363 | return -EINVAL; |
3364 | ||
37e4ab3f OC |
3365 | /* |
3366 | * Allow unprivileged RT tasks to decrease priority: | |
3367 | */ | |
961ccddd | 3368 | if (user && !capable(CAP_SYS_NICE)) { |
d50dde5a | 3369 | if (fair_policy(policy)) { |
d0ea0268 | 3370 | if (attr->sched_nice < task_nice(p) && |
eaad4513 | 3371 | !can_nice(p, attr->sched_nice)) |
d50dde5a DF |
3372 | return -EPERM; |
3373 | } | |
3374 | ||
e05606d3 | 3375 | if (rt_policy(policy)) { |
a44702e8 ON |
3376 | unsigned long rlim_rtprio = |
3377 | task_rlimit(p, RLIMIT_RTPRIO); | |
8dc3e909 ON |
3378 | |
3379 | /* can't set/change the rt policy */ | |
3380 | if (policy != p->policy && !rlim_rtprio) | |
3381 | return -EPERM; | |
3382 | ||
3383 | /* can't increase priority */ | |
d50dde5a DF |
3384 | if (attr->sched_priority > p->rt_priority && |
3385 | attr->sched_priority > rlim_rtprio) | |
8dc3e909 ON |
3386 | return -EPERM; |
3387 | } | |
c02aa73b | 3388 | |
d44753b8 JL |
3389 | /* |
3390 | * Can't set/change SCHED_DEADLINE policy at all for now | |
3391 | * (safest behavior); in the future we would like to allow | |
3392 | * unprivileged DL tasks to increase their relative deadline | |
3393 | * or reduce their runtime (both ways reducing utilization) | |
3394 | */ | |
3395 | if (dl_policy(policy)) | |
3396 | return -EPERM; | |
3397 | ||
dd41f596 | 3398 | /* |
c02aa73b DH |
3399 | * Treat SCHED_IDLE as nice 20. Only allow a switch to |
3400 | * SCHED_NORMAL if the RLIMIT_NICE would normally permit it. | |
dd41f596 | 3401 | */ |
c02aa73b | 3402 | if (p->policy == SCHED_IDLE && policy != SCHED_IDLE) { |
d0ea0268 | 3403 | if (!can_nice(p, task_nice(p))) |
c02aa73b DH |
3404 | return -EPERM; |
3405 | } | |
5fe1d75f | 3406 | |
37e4ab3f | 3407 | /* can't change other user's priorities */ |
c69e8d9c | 3408 | if (!check_same_owner(p)) |
37e4ab3f | 3409 | return -EPERM; |
ca94c442 LP |
3410 | |
3411 | /* Normal users shall not reset the sched_reset_on_fork flag */ | |
3412 | if (p->sched_reset_on_fork && !reset_on_fork) | |
3413 | return -EPERM; | |
37e4ab3f | 3414 | } |
1da177e4 | 3415 | |
725aad24 | 3416 | if (user) { |
b0ae1981 | 3417 | retval = security_task_setscheduler(p); |
725aad24 JF |
3418 | if (retval) |
3419 | return retval; | |
3420 | } | |
3421 | ||
b29739f9 IM |
3422 | /* |
3423 | * make sure no PI-waiters arrive (or leave) while we are | |
3424 | * changing the priority of the task: | |
0122ec5b | 3425 | * |
25985edc | 3426 | * To be able to change p->policy safely, the appropriate |
1da177e4 LT |
3427 | * runqueue lock must be held. |
3428 | */ | |
0122ec5b | 3429 | rq = task_rq_lock(p, &flags); |
dc61b1d6 | 3430 | |
34f971f6 PZ |
3431 | /* |
3432 | * Changing the policy of the stop threads its a very bad idea | |
3433 | */ | |
3434 | if (p == rq->stop) { | |
0122ec5b | 3435 | task_rq_unlock(rq, p, &flags); |
34f971f6 PZ |
3436 | return -EINVAL; |
3437 | } | |
3438 | ||
a51e9198 | 3439 | /* |
d6b1e911 TG |
3440 | * If not changing anything there's no need to proceed further, |
3441 | * but store a possible modification of reset_on_fork. | |
a51e9198 | 3442 | */ |
d50dde5a | 3443 | if (unlikely(policy == p->policy)) { |
d0ea0268 | 3444 | if (fair_policy(policy) && attr->sched_nice != task_nice(p)) |
d50dde5a DF |
3445 | goto change; |
3446 | if (rt_policy(policy) && attr->sched_priority != p->rt_priority) | |
3447 | goto change; | |
aab03e05 DF |
3448 | if (dl_policy(policy)) |
3449 | goto change; | |
d50dde5a | 3450 | |
d6b1e911 | 3451 | p->sched_reset_on_fork = reset_on_fork; |
45afb173 | 3452 | task_rq_unlock(rq, p, &flags); |
a51e9198 DF |
3453 | return 0; |
3454 | } | |
d50dde5a | 3455 | change: |
a51e9198 | 3456 | |
dc61b1d6 | 3457 | if (user) { |
332ac17e | 3458 | #ifdef CONFIG_RT_GROUP_SCHED |
dc61b1d6 PZ |
3459 | /* |
3460 | * Do not allow realtime tasks into groups that have no runtime | |
3461 | * assigned. | |
3462 | */ | |
3463 | if (rt_bandwidth_enabled() && rt_policy(policy) && | |
f4493771 MG |
3464 | task_group(p)->rt_bandwidth.rt_runtime == 0 && |
3465 | !task_group_is_autogroup(task_group(p))) { | |
0122ec5b | 3466 | task_rq_unlock(rq, p, &flags); |
dc61b1d6 PZ |
3467 | return -EPERM; |
3468 | } | |
dc61b1d6 | 3469 | #endif |
332ac17e DF |
3470 | #ifdef CONFIG_SMP |
3471 | if (dl_bandwidth_enabled() && dl_policy(policy)) { | |
3472 | cpumask_t *span = rq->rd->span; | |
332ac17e DF |
3473 | |
3474 | /* | |
3475 | * Don't allow tasks with an affinity mask smaller than | |
3476 | * the entire root_domain to become SCHED_DEADLINE. We | |
3477 | * will also fail if there's no bandwidth available. | |
3478 | */ | |
e4099a5e PZ |
3479 | if (!cpumask_subset(span, &p->cpus_allowed) || |
3480 | rq->rd->dl_bw.bw == 0) { | |
332ac17e DF |
3481 | task_rq_unlock(rq, p, &flags); |
3482 | return -EPERM; | |
3483 | } | |
3484 | } | |
3485 | #endif | |
3486 | } | |
dc61b1d6 | 3487 | |
1da177e4 LT |
3488 | /* recheck policy now with rq lock held */ |
3489 | if (unlikely(oldpolicy != -1 && oldpolicy != p->policy)) { | |
3490 | policy = oldpolicy = -1; | |
0122ec5b | 3491 | task_rq_unlock(rq, p, &flags); |
1da177e4 LT |
3492 | goto recheck; |
3493 | } | |
332ac17e DF |
3494 | |
3495 | /* | |
3496 | * If setscheduling to SCHED_DEADLINE (or changing the parameters | |
3497 | * of a SCHED_DEADLINE task) we need to check if enough bandwidth | |
3498 | * is available. | |
3499 | */ | |
e4099a5e | 3500 | if ((dl_policy(policy) || dl_task(p)) && dl_overflow(p, policy, attr)) { |
332ac17e DF |
3501 | task_rq_unlock(rq, p, &flags); |
3502 | return -EBUSY; | |
3503 | } | |
3504 | ||
c365c292 TG |
3505 | p->sched_reset_on_fork = reset_on_fork; |
3506 | oldprio = p->prio; | |
3507 | ||
3508 | /* | |
3509 | * Special case for priority boosted tasks. | |
3510 | * | |
3511 | * If the new priority is lower or equal (user space view) | |
3512 | * than the current (boosted) priority, we just store the new | |
3513 | * normal parameters and do not touch the scheduler class and | |
3514 | * the runqueue. This will be done when the task deboost | |
3515 | * itself. | |
3516 | */ | |
3517 | if (rt_mutex_check_prio(p, newprio)) { | |
3518 | __setscheduler_params(p, attr); | |
3519 | task_rq_unlock(rq, p, &flags); | |
3520 | return 0; | |
3521 | } | |
3522 | ||
fd2f4419 | 3523 | on_rq = p->on_rq; |
051a1d1a | 3524 | running = task_current(rq, p); |
0e1f3483 | 3525 | if (on_rq) |
4ca9b72b | 3526 | dequeue_task(rq, p, 0); |
0e1f3483 HS |
3527 | if (running) |
3528 | p->sched_class->put_prev_task(rq, p); | |
f6b53205 | 3529 | |
83ab0aa0 | 3530 | prev_class = p->sched_class; |
d50dde5a | 3531 | __setscheduler(rq, p, attr); |
f6b53205 | 3532 | |
0e1f3483 HS |
3533 | if (running) |
3534 | p->sched_class->set_curr_task(rq); | |
81a44c54 TG |
3535 | if (on_rq) { |
3536 | /* | |
3537 | * We enqueue to tail when the priority of a task is | |
3538 | * increased (user space view). | |
3539 | */ | |
3540 | enqueue_task(rq, p, oldprio <= p->prio ? ENQUEUE_HEAD : 0); | |
3541 | } | |
cb469845 | 3542 | |
da7a735e | 3543 | check_class_changed(rq, p, prev_class, oldprio); |
0122ec5b | 3544 | task_rq_unlock(rq, p, &flags); |
b29739f9 | 3545 | |
95e02ca9 TG |
3546 | rt_mutex_adjust_pi(p); |
3547 | ||
1da177e4 LT |
3548 | return 0; |
3549 | } | |
961ccddd | 3550 | |
7479f3c9 PZ |
3551 | static int _sched_setscheduler(struct task_struct *p, int policy, |
3552 | const struct sched_param *param, bool check) | |
3553 | { | |
3554 | struct sched_attr attr = { | |
3555 | .sched_policy = policy, | |
3556 | .sched_priority = param->sched_priority, | |
3557 | .sched_nice = PRIO_TO_NICE(p->static_prio), | |
3558 | }; | |
3559 | ||
3560 | /* | |
3561 | * Fixup the legacy SCHED_RESET_ON_FORK hack | |
3562 | */ | |
3563 | if (policy & SCHED_RESET_ON_FORK) { | |
3564 | attr.sched_flags |= SCHED_FLAG_RESET_ON_FORK; | |
3565 | policy &= ~SCHED_RESET_ON_FORK; | |
3566 | attr.sched_policy = policy; | |
3567 | } | |
3568 | ||
3569 | return __sched_setscheduler(p, &attr, check); | |
3570 | } | |
961ccddd RR |
3571 | /** |
3572 | * sched_setscheduler - change the scheduling policy and/or RT priority of a thread. | |
3573 | * @p: the task in question. | |
3574 | * @policy: new policy. | |
3575 | * @param: structure containing the new RT priority. | |
3576 | * | |
e69f6186 YB |
3577 | * Return: 0 on success. An error code otherwise. |
3578 | * | |
961ccddd RR |
3579 | * NOTE that the task may be already dead. |
3580 | */ | |
3581 | int sched_setscheduler(struct task_struct *p, int policy, | |
fe7de49f | 3582 | const struct sched_param *param) |
961ccddd | 3583 | { |
7479f3c9 | 3584 | return _sched_setscheduler(p, policy, param, true); |
961ccddd | 3585 | } |
1da177e4 LT |
3586 | EXPORT_SYMBOL_GPL(sched_setscheduler); |
3587 | ||
d50dde5a DF |
3588 | int sched_setattr(struct task_struct *p, const struct sched_attr *attr) |
3589 | { | |
3590 | return __sched_setscheduler(p, attr, true); | |
3591 | } | |
3592 | EXPORT_SYMBOL_GPL(sched_setattr); | |
3593 | ||
961ccddd RR |
3594 | /** |
3595 | * sched_setscheduler_nocheck - change the scheduling policy and/or RT priority of a thread from kernelspace. | |
3596 | * @p: the task in question. | |
3597 | * @policy: new policy. | |
3598 | * @param: structure containing the new RT priority. | |
3599 | * | |
3600 | * Just like sched_setscheduler, only don't bother checking if the | |
3601 | * current context has permission. For example, this is needed in | |
3602 | * stop_machine(): we create temporary high priority worker threads, | |
3603 | * but our caller might not have that capability. | |
e69f6186 YB |
3604 | * |
3605 | * Return: 0 on success. An error code otherwise. | |
961ccddd RR |
3606 | */ |
3607 | int sched_setscheduler_nocheck(struct task_struct *p, int policy, | |
fe7de49f | 3608 | const struct sched_param *param) |
961ccddd | 3609 | { |
7479f3c9 | 3610 | return _sched_setscheduler(p, policy, param, false); |
961ccddd RR |
3611 | } |
3612 | ||
95cdf3b7 IM |
3613 | static int |
3614 | do_sched_setscheduler(pid_t pid, int policy, struct sched_param __user *param) | |
1da177e4 | 3615 | { |
1da177e4 LT |
3616 | struct sched_param lparam; |
3617 | struct task_struct *p; | |
36c8b586 | 3618 | int retval; |
1da177e4 LT |
3619 | |
3620 | if (!param || pid < 0) | |
3621 | return -EINVAL; | |
3622 | if (copy_from_user(&lparam, param, sizeof(struct sched_param))) | |
3623 | return -EFAULT; | |
5fe1d75f ON |
3624 | |
3625 | rcu_read_lock(); | |
3626 | retval = -ESRCH; | |
1da177e4 | 3627 | p = find_process_by_pid(pid); |
5fe1d75f ON |
3628 | if (p != NULL) |
3629 | retval = sched_setscheduler(p, policy, &lparam); | |
3630 | rcu_read_unlock(); | |
36c8b586 | 3631 | |
1da177e4 LT |
3632 | return retval; |
3633 | } | |
3634 | ||
d50dde5a DF |
3635 | /* |
3636 | * Mimics kernel/events/core.c perf_copy_attr(). | |
3637 | */ | |
3638 | static int sched_copy_attr(struct sched_attr __user *uattr, | |
3639 | struct sched_attr *attr) | |
3640 | { | |
3641 | u32 size; | |
3642 | int ret; | |
3643 | ||
3644 | if (!access_ok(VERIFY_WRITE, uattr, SCHED_ATTR_SIZE_VER0)) | |
3645 | return -EFAULT; | |
3646 | ||
3647 | /* | |
3648 | * zero the full structure, so that a short copy will be nice. | |
3649 | */ | |
3650 | memset(attr, 0, sizeof(*attr)); | |
3651 | ||
3652 | ret = get_user(size, &uattr->size); | |
3653 | if (ret) | |
3654 | return ret; | |
3655 | ||
3656 | if (size > PAGE_SIZE) /* silly large */ | |
3657 | goto err_size; | |
3658 | ||
3659 | if (!size) /* abi compat */ | |
3660 | size = SCHED_ATTR_SIZE_VER0; | |
3661 | ||
3662 | if (size < SCHED_ATTR_SIZE_VER0) | |
3663 | goto err_size; | |
3664 | ||
3665 | /* | |
3666 | * If we're handed a bigger struct than we know of, | |
3667 | * ensure all the unknown bits are 0 - i.e. new | |
3668 | * user-space does not rely on any kernel feature | |
3669 | * extensions we dont know about yet. | |
3670 | */ | |
3671 | if (size > sizeof(*attr)) { | |
3672 | unsigned char __user *addr; | |
3673 | unsigned char __user *end; | |
3674 | unsigned char val; | |
3675 | ||
3676 | addr = (void __user *)uattr + sizeof(*attr); | |
3677 | end = (void __user *)uattr + size; | |
3678 | ||
3679 | for (; addr < end; addr++) { | |
3680 | ret = get_user(val, addr); | |
3681 | if (ret) | |
3682 | return ret; | |
3683 | if (val) | |
3684 | goto err_size; | |
3685 | } | |
3686 | size = sizeof(*attr); | |
3687 | } | |
3688 | ||
3689 | ret = copy_from_user(attr, uattr, size); | |
3690 | if (ret) | |
3691 | return -EFAULT; | |
3692 | ||
3693 | /* | |
3694 | * XXX: do we want to be lenient like existing syscalls; or do we want | |
3695 | * to be strict and return an error on out-of-bounds values? | |
3696 | */ | |
75e45d51 | 3697 | attr->sched_nice = clamp(attr->sched_nice, MIN_NICE, MAX_NICE); |
d50dde5a | 3698 | |
e78c7bca | 3699 | return 0; |
d50dde5a DF |
3700 | |
3701 | err_size: | |
3702 | put_user(sizeof(*attr), &uattr->size); | |
e78c7bca | 3703 | return -E2BIG; |
d50dde5a DF |
3704 | } |
3705 | ||
1da177e4 LT |
3706 | /** |
3707 | * sys_sched_setscheduler - set/change the scheduler policy and RT priority | |
3708 | * @pid: the pid in question. | |
3709 | * @policy: new policy. | |
3710 | * @param: structure containing the new RT priority. | |
e69f6186 YB |
3711 | * |
3712 | * Return: 0 on success. An error code otherwise. | |
1da177e4 | 3713 | */ |
5add95d4 HC |
3714 | SYSCALL_DEFINE3(sched_setscheduler, pid_t, pid, int, policy, |
3715 | struct sched_param __user *, param) | |
1da177e4 | 3716 | { |
c21761f1 JB |
3717 | /* negative values for policy are not valid */ |
3718 | if (policy < 0) | |
3719 | return -EINVAL; | |
3720 | ||
1da177e4 LT |
3721 | return do_sched_setscheduler(pid, policy, param); |
3722 | } | |
3723 | ||
3724 | /** | |
3725 | * sys_sched_setparam - set/change the RT priority of a thread | |
3726 | * @pid: the pid in question. | |
3727 | * @param: structure containing the new RT priority. | |
e69f6186 YB |
3728 | * |
3729 | * Return: 0 on success. An error code otherwise. | |
1da177e4 | 3730 | */ |
5add95d4 | 3731 | SYSCALL_DEFINE2(sched_setparam, pid_t, pid, struct sched_param __user *, param) |
1da177e4 LT |
3732 | { |
3733 | return do_sched_setscheduler(pid, -1, param); | |
3734 | } | |
3735 | ||
d50dde5a DF |
3736 | /** |
3737 | * sys_sched_setattr - same as above, but with extended sched_attr | |
3738 | * @pid: the pid in question. | |
5778fccf | 3739 | * @uattr: structure containing the extended parameters. |
db66d756 | 3740 | * @flags: for future extension. |
d50dde5a | 3741 | */ |
6d35ab48 PZ |
3742 | SYSCALL_DEFINE3(sched_setattr, pid_t, pid, struct sched_attr __user *, uattr, |
3743 | unsigned int, flags) | |
d50dde5a DF |
3744 | { |
3745 | struct sched_attr attr; | |
3746 | struct task_struct *p; | |
3747 | int retval; | |
3748 | ||
6d35ab48 | 3749 | if (!uattr || pid < 0 || flags) |
d50dde5a DF |
3750 | return -EINVAL; |
3751 | ||
143cf23d MK |
3752 | retval = sched_copy_attr(uattr, &attr); |
3753 | if (retval) | |
3754 | return retval; | |
d50dde5a | 3755 | |
b14ed2c2 | 3756 | if ((int)attr.sched_policy < 0) |
dbdb2275 | 3757 | return -EINVAL; |
d50dde5a DF |
3758 | |
3759 | rcu_read_lock(); | |
3760 | retval = -ESRCH; | |
3761 | p = find_process_by_pid(pid); | |
3762 | if (p != NULL) | |
3763 | retval = sched_setattr(p, &attr); | |
3764 | rcu_read_unlock(); | |
3765 | ||
3766 | return retval; | |
3767 | } | |
3768 | ||
1da177e4 LT |
3769 | /** |
3770 | * sys_sched_getscheduler - get the policy (scheduling class) of a thread | |
3771 | * @pid: the pid in question. | |
e69f6186 YB |
3772 | * |
3773 | * Return: On success, the policy of the thread. Otherwise, a negative error | |
3774 | * code. | |
1da177e4 | 3775 | */ |
5add95d4 | 3776 | SYSCALL_DEFINE1(sched_getscheduler, pid_t, pid) |
1da177e4 | 3777 | { |
36c8b586 | 3778 | struct task_struct *p; |
3a5c359a | 3779 | int retval; |
1da177e4 LT |
3780 | |
3781 | if (pid < 0) | |
3a5c359a | 3782 | return -EINVAL; |
1da177e4 LT |
3783 | |
3784 | retval = -ESRCH; | |
5fe85be0 | 3785 | rcu_read_lock(); |
1da177e4 LT |
3786 | p = find_process_by_pid(pid); |
3787 | if (p) { | |
3788 | retval = security_task_getscheduler(p); | |
3789 | if (!retval) | |
ca94c442 LP |
3790 | retval = p->policy |
3791 | | (p->sched_reset_on_fork ? SCHED_RESET_ON_FORK : 0); | |
1da177e4 | 3792 | } |
5fe85be0 | 3793 | rcu_read_unlock(); |
1da177e4 LT |
3794 | return retval; |
3795 | } | |
3796 | ||
3797 | /** | |
ca94c442 | 3798 | * sys_sched_getparam - get the RT priority of a thread |
1da177e4 LT |
3799 | * @pid: the pid in question. |
3800 | * @param: structure containing the RT priority. | |
e69f6186 YB |
3801 | * |
3802 | * Return: On success, 0 and the RT priority is in @param. Otherwise, an error | |
3803 | * code. | |
1da177e4 | 3804 | */ |
5add95d4 | 3805 | SYSCALL_DEFINE2(sched_getparam, pid_t, pid, struct sched_param __user *, param) |
1da177e4 | 3806 | { |
ce5f7f82 | 3807 | struct sched_param lp = { .sched_priority = 0 }; |
36c8b586 | 3808 | struct task_struct *p; |
3a5c359a | 3809 | int retval; |
1da177e4 LT |
3810 | |
3811 | if (!param || pid < 0) | |
3a5c359a | 3812 | return -EINVAL; |
1da177e4 | 3813 | |
5fe85be0 | 3814 | rcu_read_lock(); |
1da177e4 LT |
3815 | p = find_process_by_pid(pid); |
3816 | retval = -ESRCH; | |
3817 | if (!p) | |
3818 | goto out_unlock; | |
3819 | ||
3820 | retval = security_task_getscheduler(p); | |
3821 | if (retval) | |
3822 | goto out_unlock; | |
3823 | ||
ce5f7f82 PZ |
3824 | if (task_has_rt_policy(p)) |
3825 | lp.sched_priority = p->rt_priority; | |
5fe85be0 | 3826 | rcu_read_unlock(); |
1da177e4 LT |
3827 | |
3828 | /* | |
3829 | * This one might sleep, we cannot do it with a spinlock held ... | |
3830 | */ | |
3831 | retval = copy_to_user(param, &lp, sizeof(*param)) ? -EFAULT : 0; | |
3832 | ||
1da177e4 LT |
3833 | return retval; |
3834 | ||
3835 | out_unlock: | |
5fe85be0 | 3836 | rcu_read_unlock(); |
1da177e4 LT |
3837 | return retval; |
3838 | } | |
3839 | ||
d50dde5a DF |
3840 | static int sched_read_attr(struct sched_attr __user *uattr, |
3841 | struct sched_attr *attr, | |
3842 | unsigned int usize) | |
3843 | { | |
3844 | int ret; | |
3845 | ||
3846 | if (!access_ok(VERIFY_WRITE, uattr, usize)) | |
3847 | return -EFAULT; | |
3848 | ||
3849 | /* | |
3850 | * If we're handed a smaller struct than we know of, | |
3851 | * ensure all the unknown bits are 0 - i.e. old | |
3852 | * user-space does not get uncomplete information. | |
3853 | */ | |
3854 | if (usize < sizeof(*attr)) { | |
3855 | unsigned char *addr; | |
3856 | unsigned char *end; | |
3857 | ||
3858 | addr = (void *)attr + usize; | |
3859 | end = (void *)attr + sizeof(*attr); | |
3860 | ||
3861 | for (; addr < end; addr++) { | |
3862 | if (*addr) | |
22400674 | 3863 | return -EFBIG; |
d50dde5a DF |
3864 | } |
3865 | ||
3866 | attr->size = usize; | |
3867 | } | |
3868 | ||
4efbc454 | 3869 | ret = copy_to_user(uattr, attr, attr->size); |
d50dde5a DF |
3870 | if (ret) |
3871 | return -EFAULT; | |
3872 | ||
22400674 | 3873 | return 0; |
d50dde5a DF |
3874 | } |
3875 | ||
3876 | /** | |
aab03e05 | 3877 | * sys_sched_getattr - similar to sched_getparam, but with sched_attr |
d50dde5a | 3878 | * @pid: the pid in question. |
5778fccf | 3879 | * @uattr: structure containing the extended parameters. |
d50dde5a | 3880 | * @size: sizeof(attr) for fwd/bwd comp. |
db66d756 | 3881 | * @flags: for future extension. |
d50dde5a | 3882 | */ |
6d35ab48 PZ |
3883 | SYSCALL_DEFINE4(sched_getattr, pid_t, pid, struct sched_attr __user *, uattr, |
3884 | unsigned int, size, unsigned int, flags) | |
d50dde5a DF |
3885 | { |
3886 | struct sched_attr attr = { | |
3887 | .size = sizeof(struct sched_attr), | |
3888 | }; | |
3889 | struct task_struct *p; | |
3890 | int retval; | |
3891 | ||
3892 | if (!uattr || pid < 0 || size > PAGE_SIZE || | |
6d35ab48 | 3893 | size < SCHED_ATTR_SIZE_VER0 || flags) |
d50dde5a DF |
3894 | return -EINVAL; |
3895 | ||
3896 | rcu_read_lock(); | |
3897 | p = find_process_by_pid(pid); | |
3898 | retval = -ESRCH; | |
3899 | if (!p) | |
3900 | goto out_unlock; | |
3901 | ||
3902 | retval = security_task_getscheduler(p); | |
3903 | if (retval) | |
3904 | goto out_unlock; | |
3905 | ||
3906 | attr.sched_policy = p->policy; | |
7479f3c9 PZ |
3907 | if (p->sched_reset_on_fork) |
3908 | attr.sched_flags |= SCHED_FLAG_RESET_ON_FORK; | |
aab03e05 DF |
3909 | if (task_has_dl_policy(p)) |
3910 | __getparam_dl(p, &attr); | |
3911 | else if (task_has_rt_policy(p)) | |
d50dde5a DF |
3912 | attr.sched_priority = p->rt_priority; |
3913 | else | |
d0ea0268 | 3914 | attr.sched_nice = task_nice(p); |
d50dde5a DF |
3915 | |
3916 | rcu_read_unlock(); | |
3917 | ||
3918 | retval = sched_read_attr(uattr, &attr, size); | |
3919 | return retval; | |
3920 | ||
3921 | out_unlock: | |
3922 | rcu_read_unlock(); | |
3923 | return retval; | |
3924 | } | |
3925 | ||
96f874e2 | 3926 | long sched_setaffinity(pid_t pid, const struct cpumask *in_mask) |
1da177e4 | 3927 | { |
5a16f3d3 | 3928 | cpumask_var_t cpus_allowed, new_mask; |
36c8b586 IM |
3929 | struct task_struct *p; |
3930 | int retval; | |
1da177e4 | 3931 | |
23f5d142 | 3932 | rcu_read_lock(); |
1da177e4 LT |
3933 | |
3934 | p = find_process_by_pid(pid); | |
3935 | if (!p) { | |
23f5d142 | 3936 | rcu_read_unlock(); |
1da177e4 LT |
3937 | return -ESRCH; |
3938 | } | |
3939 | ||
23f5d142 | 3940 | /* Prevent p going away */ |
1da177e4 | 3941 | get_task_struct(p); |
23f5d142 | 3942 | rcu_read_unlock(); |
1da177e4 | 3943 | |
14a40ffc TH |
3944 | if (p->flags & PF_NO_SETAFFINITY) { |
3945 | retval = -EINVAL; | |
3946 | goto out_put_task; | |
3947 | } | |
5a16f3d3 RR |
3948 | if (!alloc_cpumask_var(&cpus_allowed, GFP_KERNEL)) { |
3949 | retval = -ENOMEM; | |
3950 | goto out_put_task; | |
3951 | } | |
3952 | if (!alloc_cpumask_var(&new_mask, GFP_KERNEL)) { | |
3953 | retval = -ENOMEM; | |
3954 | goto out_free_cpus_allowed; | |
3955 | } | |
1da177e4 | 3956 | retval = -EPERM; |
4c44aaaf EB |
3957 | if (!check_same_owner(p)) { |
3958 | rcu_read_lock(); | |
3959 | if (!ns_capable(__task_cred(p)->user_ns, CAP_SYS_NICE)) { | |
3960 | rcu_read_unlock(); | |
3961 | goto out_unlock; | |
3962 | } | |
3963 | rcu_read_unlock(); | |
3964 | } | |
1da177e4 | 3965 | |
b0ae1981 | 3966 | retval = security_task_setscheduler(p); |
e7834f8f DQ |
3967 | if (retval) |
3968 | goto out_unlock; | |
3969 | ||
e4099a5e PZ |
3970 | |
3971 | cpuset_cpus_allowed(p, cpus_allowed); | |
3972 | cpumask_and(new_mask, in_mask, cpus_allowed); | |
3973 | ||
332ac17e DF |
3974 | /* |
3975 | * Since bandwidth control happens on root_domain basis, | |
3976 | * if admission test is enabled, we only admit -deadline | |
3977 | * tasks allowed to run on all the CPUs in the task's | |
3978 | * root_domain. | |
3979 | */ | |
3980 | #ifdef CONFIG_SMP | |
3981 | if (task_has_dl_policy(p)) { | |
3982 | const struct cpumask *span = task_rq(p)->rd->span; | |
3983 | ||
e4099a5e | 3984 | if (dl_bandwidth_enabled() && !cpumask_subset(span, new_mask)) { |
332ac17e DF |
3985 | retval = -EBUSY; |
3986 | goto out_unlock; | |
3987 | } | |
3988 | } | |
3989 | #endif | |
49246274 | 3990 | again: |
5a16f3d3 | 3991 | retval = set_cpus_allowed_ptr(p, new_mask); |
1da177e4 | 3992 | |
8707d8b8 | 3993 | if (!retval) { |
5a16f3d3 RR |
3994 | cpuset_cpus_allowed(p, cpus_allowed); |
3995 | if (!cpumask_subset(new_mask, cpus_allowed)) { | |
8707d8b8 PM |
3996 | /* |
3997 | * We must have raced with a concurrent cpuset | |
3998 | * update. Just reset the cpus_allowed to the | |
3999 | * cpuset's cpus_allowed | |
4000 | */ | |
5a16f3d3 | 4001 | cpumask_copy(new_mask, cpus_allowed); |
8707d8b8 PM |
4002 | goto again; |
4003 | } | |
4004 | } | |
1da177e4 | 4005 | out_unlock: |
5a16f3d3 RR |
4006 | free_cpumask_var(new_mask); |
4007 | out_free_cpus_allowed: | |
4008 | free_cpumask_var(cpus_allowed); | |
4009 | out_put_task: | |
1da177e4 | 4010 | put_task_struct(p); |
1da177e4 LT |
4011 | return retval; |
4012 | } | |
4013 | ||
4014 | static int get_user_cpu_mask(unsigned long __user *user_mask_ptr, unsigned len, | |
96f874e2 | 4015 | struct cpumask *new_mask) |
1da177e4 | 4016 | { |
96f874e2 RR |
4017 | if (len < cpumask_size()) |
4018 | cpumask_clear(new_mask); | |
4019 | else if (len > cpumask_size()) | |
4020 | len = cpumask_size(); | |
4021 | ||
1da177e4 LT |
4022 | return copy_from_user(new_mask, user_mask_ptr, len) ? -EFAULT : 0; |
4023 | } | |
4024 | ||
4025 | /** | |
4026 | * sys_sched_setaffinity - set the cpu affinity of a process | |
4027 | * @pid: pid of the process | |
4028 | * @len: length in bytes of the bitmask pointed to by user_mask_ptr | |
4029 | * @user_mask_ptr: user-space pointer to the new cpu mask | |
e69f6186 YB |
4030 | * |
4031 | * Return: 0 on success. An error code otherwise. | |
1da177e4 | 4032 | */ |
5add95d4 HC |
4033 | SYSCALL_DEFINE3(sched_setaffinity, pid_t, pid, unsigned int, len, |
4034 | unsigned long __user *, user_mask_ptr) | |
1da177e4 | 4035 | { |
5a16f3d3 | 4036 | cpumask_var_t new_mask; |
1da177e4 LT |
4037 | int retval; |
4038 | ||
5a16f3d3 RR |
4039 | if (!alloc_cpumask_var(&new_mask, GFP_KERNEL)) |
4040 | return -ENOMEM; | |
1da177e4 | 4041 | |
5a16f3d3 RR |
4042 | retval = get_user_cpu_mask(user_mask_ptr, len, new_mask); |
4043 | if (retval == 0) | |
4044 | retval = sched_setaffinity(pid, new_mask); | |
4045 | free_cpumask_var(new_mask); | |
4046 | return retval; | |
1da177e4 LT |
4047 | } |
4048 | ||
96f874e2 | 4049 | long sched_getaffinity(pid_t pid, struct cpumask *mask) |
1da177e4 | 4050 | { |
36c8b586 | 4051 | struct task_struct *p; |
31605683 | 4052 | unsigned long flags; |
1da177e4 | 4053 | int retval; |
1da177e4 | 4054 | |
23f5d142 | 4055 | rcu_read_lock(); |
1da177e4 LT |
4056 | |
4057 | retval = -ESRCH; | |
4058 | p = find_process_by_pid(pid); | |
4059 | if (!p) | |
4060 | goto out_unlock; | |
4061 | ||
e7834f8f DQ |
4062 | retval = security_task_getscheduler(p); |
4063 | if (retval) | |
4064 | goto out_unlock; | |
4065 | ||
013fdb80 | 4066 | raw_spin_lock_irqsave(&p->pi_lock, flags); |
6acce3ef | 4067 | cpumask_and(mask, &p->cpus_allowed, cpu_active_mask); |
013fdb80 | 4068 | raw_spin_unlock_irqrestore(&p->pi_lock, flags); |
1da177e4 LT |
4069 | |
4070 | out_unlock: | |
23f5d142 | 4071 | rcu_read_unlock(); |
1da177e4 | 4072 | |
9531b62f | 4073 | return retval; |
1da177e4 LT |
4074 | } |
4075 | ||
4076 | /** | |
4077 | * sys_sched_getaffinity - get the cpu affinity of a process | |
4078 | * @pid: pid of the process | |
4079 | * @len: length in bytes of the bitmask pointed to by user_mask_ptr | |
4080 | * @user_mask_ptr: user-space pointer to hold the current cpu mask | |
e69f6186 YB |
4081 | * |
4082 | * Return: 0 on success. An error code otherwise. | |
1da177e4 | 4083 | */ |
5add95d4 HC |
4084 | SYSCALL_DEFINE3(sched_getaffinity, pid_t, pid, unsigned int, len, |
4085 | unsigned long __user *, user_mask_ptr) | |
1da177e4 LT |
4086 | { |
4087 | int ret; | |
f17c8607 | 4088 | cpumask_var_t mask; |
1da177e4 | 4089 | |
84fba5ec | 4090 | if ((len * BITS_PER_BYTE) < nr_cpu_ids) |
cd3d8031 KM |
4091 | return -EINVAL; |
4092 | if (len & (sizeof(unsigned long)-1)) | |
1da177e4 LT |
4093 | return -EINVAL; |
4094 | ||
f17c8607 RR |
4095 | if (!alloc_cpumask_var(&mask, GFP_KERNEL)) |
4096 | return -ENOMEM; | |
1da177e4 | 4097 | |
f17c8607 RR |
4098 | ret = sched_getaffinity(pid, mask); |
4099 | if (ret == 0) { | |
8bc037fb | 4100 | size_t retlen = min_t(size_t, len, cpumask_size()); |
cd3d8031 KM |
4101 | |
4102 | if (copy_to_user(user_mask_ptr, mask, retlen)) | |
f17c8607 RR |
4103 | ret = -EFAULT; |
4104 | else | |
cd3d8031 | 4105 | ret = retlen; |
f17c8607 RR |
4106 | } |
4107 | free_cpumask_var(mask); | |
1da177e4 | 4108 | |
f17c8607 | 4109 | return ret; |
1da177e4 LT |
4110 | } |
4111 | ||
4112 | /** | |
4113 | * sys_sched_yield - yield the current processor to other threads. | |
4114 | * | |
dd41f596 IM |
4115 | * This function yields the current CPU to other tasks. If there are no |
4116 | * other threads running on this CPU then this function will return. | |
e69f6186 YB |
4117 | * |
4118 | * Return: 0. | |
1da177e4 | 4119 | */ |
5add95d4 | 4120 | SYSCALL_DEFINE0(sched_yield) |
1da177e4 | 4121 | { |
70b97a7f | 4122 | struct rq *rq = this_rq_lock(); |
1da177e4 | 4123 | |
2d72376b | 4124 | schedstat_inc(rq, yld_count); |
4530d7ab | 4125 | current->sched_class->yield_task(rq); |
1da177e4 LT |
4126 | |
4127 | /* | |
4128 | * Since we are going to call schedule() anyway, there's | |
4129 | * no need to preempt or enable interrupts: | |
4130 | */ | |
4131 | __release(rq->lock); | |
8a25d5de | 4132 | spin_release(&rq->lock.dep_map, 1, _THIS_IP_); |
9828ea9d | 4133 | do_raw_spin_unlock(&rq->lock); |
ba74c144 | 4134 | sched_preempt_enable_no_resched(); |
1da177e4 LT |
4135 | |
4136 | schedule(); | |
4137 | ||
4138 | return 0; | |
4139 | } | |
4140 | ||
e7b38404 | 4141 | static void __cond_resched(void) |
1da177e4 | 4142 | { |
bdb43806 | 4143 | __preempt_count_add(PREEMPT_ACTIVE); |
c259e01a | 4144 | __schedule(); |
bdb43806 | 4145 | __preempt_count_sub(PREEMPT_ACTIVE); |
1da177e4 LT |
4146 | } |
4147 | ||
02b67cc3 | 4148 | int __sched _cond_resched(void) |
1da177e4 | 4149 | { |
ac1bea85 | 4150 | rcu_cond_resched(); |
d86ee480 | 4151 | if (should_resched()) { |
1da177e4 LT |
4152 | __cond_resched(); |
4153 | return 1; | |
4154 | } | |
4155 | return 0; | |
4156 | } | |
02b67cc3 | 4157 | EXPORT_SYMBOL(_cond_resched); |
1da177e4 LT |
4158 | |
4159 | /* | |
613afbf8 | 4160 | * __cond_resched_lock() - if a reschedule is pending, drop the given lock, |
1da177e4 LT |
4161 | * call schedule, and on return reacquire the lock. |
4162 | * | |
41a2d6cf | 4163 | * This works OK both with and without CONFIG_PREEMPT. We do strange low-level |
1da177e4 LT |
4164 | * operations here to prevent schedule() from being called twice (once via |
4165 | * spin_unlock(), once by hand). | |
4166 | */ | |
613afbf8 | 4167 | int __cond_resched_lock(spinlock_t *lock) |
1da177e4 | 4168 | { |
ac1bea85 | 4169 | bool need_rcu_resched = rcu_should_resched(); |
d86ee480 | 4170 | int resched = should_resched(); |
6df3cecb JK |
4171 | int ret = 0; |
4172 | ||
f607c668 PZ |
4173 | lockdep_assert_held(lock); |
4174 | ||
ac1bea85 | 4175 | if (spin_needbreak(lock) || resched || need_rcu_resched) { |
1da177e4 | 4176 | spin_unlock(lock); |
d86ee480 | 4177 | if (resched) |
95c354fe | 4178 | __cond_resched(); |
ac1bea85 PM |
4179 | else if (unlikely(need_rcu_resched)) |
4180 | rcu_resched(); | |
95c354fe NP |
4181 | else |
4182 | cpu_relax(); | |
6df3cecb | 4183 | ret = 1; |
1da177e4 | 4184 | spin_lock(lock); |
1da177e4 | 4185 | } |
6df3cecb | 4186 | return ret; |
1da177e4 | 4187 | } |
613afbf8 | 4188 | EXPORT_SYMBOL(__cond_resched_lock); |
1da177e4 | 4189 | |
613afbf8 | 4190 | int __sched __cond_resched_softirq(void) |
1da177e4 LT |
4191 | { |
4192 | BUG_ON(!in_softirq()); | |
4193 | ||
ac1bea85 | 4194 | rcu_cond_resched(); /* BH disabled OK, just recording QSes. */ |
d86ee480 | 4195 | if (should_resched()) { |
98d82567 | 4196 | local_bh_enable(); |
1da177e4 LT |
4197 | __cond_resched(); |
4198 | local_bh_disable(); | |
4199 | return 1; | |
4200 | } | |
4201 | return 0; | |
4202 | } | |
613afbf8 | 4203 | EXPORT_SYMBOL(__cond_resched_softirq); |
1da177e4 | 4204 | |
1da177e4 LT |
4205 | /** |
4206 | * yield - yield the current processor to other threads. | |
4207 | * | |
8e3fabfd PZ |
4208 | * Do not ever use this function, there's a 99% chance you're doing it wrong. |
4209 | * | |
4210 | * The scheduler is at all times free to pick the calling task as the most | |
4211 | * eligible task to run, if removing the yield() call from your code breaks | |
4212 | * it, its already broken. | |
4213 | * | |
4214 | * Typical broken usage is: | |
4215 | * | |
4216 | * while (!event) | |
4217 | * yield(); | |
4218 | * | |
4219 | * where one assumes that yield() will let 'the other' process run that will | |
4220 | * make event true. If the current task is a SCHED_FIFO task that will never | |
4221 | * happen. Never use yield() as a progress guarantee!! | |
4222 | * | |
4223 | * If you want to use yield() to wait for something, use wait_event(). | |
4224 | * If you want to use yield() to be 'nice' for others, use cond_resched(). | |
4225 | * If you still want to use yield(), do not! | |
1da177e4 LT |
4226 | */ |
4227 | void __sched yield(void) | |
4228 | { | |
4229 | set_current_state(TASK_RUNNING); | |
4230 | sys_sched_yield(); | |
4231 | } | |
1da177e4 LT |
4232 | EXPORT_SYMBOL(yield); |
4233 | ||
d95f4122 MG |
4234 | /** |
4235 | * yield_to - yield the current processor to another thread in | |
4236 | * your thread group, or accelerate that thread toward the | |
4237 | * processor it's on. | |
16addf95 RD |
4238 | * @p: target task |
4239 | * @preempt: whether task preemption is allowed or not | |
d95f4122 MG |
4240 | * |
4241 | * It's the caller's job to ensure that the target task struct | |
4242 | * can't go away on us before we can do any checks. | |
4243 | * | |
e69f6186 | 4244 | * Return: |
7b270f60 PZ |
4245 | * true (>0) if we indeed boosted the target task. |
4246 | * false (0) if we failed to boost the target. | |
4247 | * -ESRCH if there's no task to yield to. | |
d95f4122 | 4248 | */ |
fa93384f | 4249 | int __sched yield_to(struct task_struct *p, bool preempt) |
d95f4122 MG |
4250 | { |
4251 | struct task_struct *curr = current; | |
4252 | struct rq *rq, *p_rq; | |
4253 | unsigned long flags; | |
c3c18640 | 4254 | int yielded = 0; |
d95f4122 MG |
4255 | |
4256 | local_irq_save(flags); | |
4257 | rq = this_rq(); | |
4258 | ||
4259 | again: | |
4260 | p_rq = task_rq(p); | |
7b270f60 PZ |
4261 | /* |
4262 | * If we're the only runnable task on the rq and target rq also | |
4263 | * has only one task, there's absolutely no point in yielding. | |
4264 | */ | |
4265 | if (rq->nr_running == 1 && p_rq->nr_running == 1) { | |
4266 | yielded = -ESRCH; | |
4267 | goto out_irq; | |
4268 | } | |
4269 | ||
d95f4122 | 4270 | double_rq_lock(rq, p_rq); |
39e24d8f | 4271 | if (task_rq(p) != p_rq) { |
d95f4122 MG |
4272 | double_rq_unlock(rq, p_rq); |
4273 | goto again; | |
4274 | } | |
4275 | ||
4276 | if (!curr->sched_class->yield_to_task) | |
7b270f60 | 4277 | goto out_unlock; |
d95f4122 MG |
4278 | |
4279 | if (curr->sched_class != p->sched_class) | |
7b270f60 | 4280 | goto out_unlock; |
d95f4122 MG |
4281 | |
4282 | if (task_running(p_rq, p) || p->state) | |
7b270f60 | 4283 | goto out_unlock; |
d95f4122 MG |
4284 | |
4285 | yielded = curr->sched_class->yield_to_task(rq, p, preempt); | |
6d1cafd8 | 4286 | if (yielded) { |
d95f4122 | 4287 | schedstat_inc(rq, yld_count); |
6d1cafd8 VP |
4288 | /* |
4289 | * Make p's CPU reschedule; pick_next_entity takes care of | |
4290 | * fairness. | |
4291 | */ | |
4292 | if (preempt && rq != p_rq) | |
4293 | resched_task(p_rq->curr); | |
4294 | } | |
d95f4122 | 4295 | |
7b270f60 | 4296 | out_unlock: |
d95f4122 | 4297 | double_rq_unlock(rq, p_rq); |
7b270f60 | 4298 | out_irq: |
d95f4122 MG |
4299 | local_irq_restore(flags); |
4300 | ||
7b270f60 | 4301 | if (yielded > 0) |
d95f4122 MG |
4302 | schedule(); |
4303 | ||
4304 | return yielded; | |
4305 | } | |
4306 | EXPORT_SYMBOL_GPL(yield_to); | |
4307 | ||
1da177e4 | 4308 | /* |
41a2d6cf | 4309 | * This task is about to go to sleep on IO. Increment rq->nr_iowait so |
1da177e4 | 4310 | * that process accounting knows that this is a task in IO wait state. |
1da177e4 LT |
4311 | */ |
4312 | void __sched io_schedule(void) | |
4313 | { | |
54d35f29 | 4314 | struct rq *rq = raw_rq(); |
1da177e4 | 4315 | |
0ff92245 | 4316 | delayacct_blkio_start(); |
1da177e4 | 4317 | atomic_inc(&rq->nr_iowait); |
73c10101 | 4318 | blk_flush_plug(current); |
8f0dfc34 | 4319 | current->in_iowait = 1; |
1da177e4 | 4320 | schedule(); |
8f0dfc34 | 4321 | current->in_iowait = 0; |
1da177e4 | 4322 | atomic_dec(&rq->nr_iowait); |
0ff92245 | 4323 | delayacct_blkio_end(); |
1da177e4 | 4324 | } |
1da177e4 LT |
4325 | EXPORT_SYMBOL(io_schedule); |
4326 | ||
4327 | long __sched io_schedule_timeout(long timeout) | |
4328 | { | |
54d35f29 | 4329 | struct rq *rq = raw_rq(); |
1da177e4 LT |
4330 | long ret; |
4331 | ||
0ff92245 | 4332 | delayacct_blkio_start(); |
1da177e4 | 4333 | atomic_inc(&rq->nr_iowait); |
73c10101 | 4334 | blk_flush_plug(current); |
8f0dfc34 | 4335 | current->in_iowait = 1; |
1da177e4 | 4336 | ret = schedule_timeout(timeout); |
8f0dfc34 | 4337 | current->in_iowait = 0; |
1da177e4 | 4338 | atomic_dec(&rq->nr_iowait); |
0ff92245 | 4339 | delayacct_blkio_end(); |
1da177e4 LT |
4340 | return ret; |
4341 | } | |
4342 | ||
4343 | /** | |
4344 | * sys_sched_get_priority_max - return maximum RT priority. | |
4345 | * @policy: scheduling class. | |
4346 | * | |
e69f6186 YB |
4347 | * Return: On success, this syscall returns the maximum |
4348 | * rt_priority that can be used by a given scheduling class. | |
4349 | * On failure, a negative error code is returned. | |
1da177e4 | 4350 | */ |
5add95d4 | 4351 | SYSCALL_DEFINE1(sched_get_priority_max, int, policy) |
1da177e4 LT |
4352 | { |
4353 | int ret = -EINVAL; | |
4354 | ||
4355 | switch (policy) { | |
4356 | case SCHED_FIFO: | |
4357 | case SCHED_RR: | |
4358 | ret = MAX_USER_RT_PRIO-1; | |
4359 | break; | |
aab03e05 | 4360 | case SCHED_DEADLINE: |
1da177e4 | 4361 | case SCHED_NORMAL: |
b0a9499c | 4362 | case SCHED_BATCH: |
dd41f596 | 4363 | case SCHED_IDLE: |
1da177e4 LT |
4364 | ret = 0; |
4365 | break; | |
4366 | } | |
4367 | return ret; | |
4368 | } | |
4369 | ||
4370 | /** | |
4371 | * sys_sched_get_priority_min - return minimum RT priority. | |
4372 | * @policy: scheduling class. | |
4373 | * | |
e69f6186 YB |
4374 | * Return: On success, this syscall returns the minimum |
4375 | * rt_priority that can be used by a given scheduling class. | |
4376 | * On failure, a negative error code is returned. | |
1da177e4 | 4377 | */ |
5add95d4 | 4378 | SYSCALL_DEFINE1(sched_get_priority_min, int, policy) |
1da177e4 LT |
4379 | { |
4380 | int ret = -EINVAL; | |
4381 | ||
4382 | switch (policy) { | |
4383 | case SCHED_FIFO: | |
4384 | case SCHED_RR: | |
4385 | ret = 1; | |
4386 | break; | |
aab03e05 | 4387 | case SCHED_DEADLINE: |
1da177e4 | 4388 | case SCHED_NORMAL: |
b0a9499c | 4389 | case SCHED_BATCH: |
dd41f596 | 4390 | case SCHED_IDLE: |
1da177e4 LT |
4391 | ret = 0; |
4392 | } | |
4393 | return ret; | |
4394 | } | |
4395 | ||
4396 | /** | |
4397 | * sys_sched_rr_get_interval - return the default timeslice of a process. | |
4398 | * @pid: pid of the process. | |
4399 | * @interval: userspace pointer to the timeslice value. | |
4400 | * | |
4401 | * this syscall writes the default timeslice value of a given process | |
4402 | * into the user-space timespec buffer. A value of '0' means infinity. | |
e69f6186 YB |
4403 | * |
4404 | * Return: On success, 0 and the timeslice is in @interval. Otherwise, | |
4405 | * an error code. | |
1da177e4 | 4406 | */ |
17da2bd9 | 4407 | SYSCALL_DEFINE2(sched_rr_get_interval, pid_t, pid, |
754fe8d2 | 4408 | struct timespec __user *, interval) |
1da177e4 | 4409 | { |
36c8b586 | 4410 | struct task_struct *p; |
a4ec24b4 | 4411 | unsigned int time_slice; |
dba091b9 TG |
4412 | unsigned long flags; |
4413 | struct rq *rq; | |
3a5c359a | 4414 | int retval; |
1da177e4 | 4415 | struct timespec t; |
1da177e4 LT |
4416 | |
4417 | if (pid < 0) | |
3a5c359a | 4418 | return -EINVAL; |
1da177e4 LT |
4419 | |
4420 | retval = -ESRCH; | |
1a551ae7 | 4421 | rcu_read_lock(); |
1da177e4 LT |
4422 | p = find_process_by_pid(pid); |
4423 | if (!p) | |
4424 | goto out_unlock; | |
4425 | ||
4426 | retval = security_task_getscheduler(p); | |
4427 | if (retval) | |
4428 | goto out_unlock; | |
4429 | ||
dba091b9 | 4430 | rq = task_rq_lock(p, &flags); |
a57beec5 PZ |
4431 | time_slice = 0; |
4432 | if (p->sched_class->get_rr_interval) | |
4433 | time_slice = p->sched_class->get_rr_interval(rq, p); | |
0122ec5b | 4434 | task_rq_unlock(rq, p, &flags); |
a4ec24b4 | 4435 | |
1a551ae7 | 4436 | rcu_read_unlock(); |
a4ec24b4 | 4437 | jiffies_to_timespec(time_slice, &t); |
1da177e4 | 4438 | retval = copy_to_user(interval, &t, sizeof(t)) ? -EFAULT : 0; |
1da177e4 | 4439 | return retval; |
3a5c359a | 4440 | |
1da177e4 | 4441 | out_unlock: |
1a551ae7 | 4442 | rcu_read_unlock(); |
1da177e4 LT |
4443 | return retval; |
4444 | } | |
4445 | ||
7c731e0a | 4446 | static const char stat_nam[] = TASK_STATE_TO_CHAR_STR; |
36c8b586 | 4447 | |
82a1fcb9 | 4448 | void sched_show_task(struct task_struct *p) |
1da177e4 | 4449 | { |
1da177e4 | 4450 | unsigned long free = 0; |
4e79752c | 4451 | int ppid; |
36c8b586 | 4452 | unsigned state; |
1da177e4 | 4453 | |
1da177e4 | 4454 | state = p->state ? __ffs(p->state) + 1 : 0; |
28d0686c | 4455 | printk(KERN_INFO "%-15.15s %c", p->comm, |
2ed6e34f | 4456 | state < sizeof(stat_nam) - 1 ? stat_nam[state] : '?'); |
4bd77321 | 4457 | #if BITS_PER_LONG == 32 |
1da177e4 | 4458 | if (state == TASK_RUNNING) |
3df0fc5b | 4459 | printk(KERN_CONT " running "); |
1da177e4 | 4460 | else |
3df0fc5b | 4461 | printk(KERN_CONT " %08lx ", thread_saved_pc(p)); |
1da177e4 LT |
4462 | #else |
4463 | if (state == TASK_RUNNING) | |
3df0fc5b | 4464 | printk(KERN_CONT " running task "); |
1da177e4 | 4465 | else |
3df0fc5b | 4466 | printk(KERN_CONT " %016lx ", thread_saved_pc(p)); |
1da177e4 LT |
4467 | #endif |
4468 | #ifdef CONFIG_DEBUG_STACK_USAGE | |
7c9f8861 | 4469 | free = stack_not_used(p); |
1da177e4 | 4470 | #endif |
4e79752c PM |
4471 | rcu_read_lock(); |
4472 | ppid = task_pid_nr(rcu_dereference(p->real_parent)); | |
4473 | rcu_read_unlock(); | |
3df0fc5b | 4474 | printk(KERN_CONT "%5lu %5d %6d 0x%08lx\n", free, |
4e79752c | 4475 | task_pid_nr(p), ppid, |
aa47b7e0 | 4476 | (unsigned long)task_thread_info(p)->flags); |
1da177e4 | 4477 | |
3d1cb205 | 4478 | print_worker_info(KERN_INFO, p); |
5fb5e6de | 4479 | show_stack(p, NULL); |
1da177e4 LT |
4480 | } |
4481 | ||
e59e2ae2 | 4482 | void show_state_filter(unsigned long state_filter) |
1da177e4 | 4483 | { |
36c8b586 | 4484 | struct task_struct *g, *p; |
1da177e4 | 4485 | |
4bd77321 | 4486 | #if BITS_PER_LONG == 32 |
3df0fc5b PZ |
4487 | printk(KERN_INFO |
4488 | " task PC stack pid father\n"); | |
1da177e4 | 4489 | #else |
3df0fc5b PZ |
4490 | printk(KERN_INFO |
4491 | " task PC stack pid father\n"); | |
1da177e4 | 4492 | #endif |
510f5acc | 4493 | rcu_read_lock(); |
1da177e4 LT |
4494 | do_each_thread(g, p) { |
4495 | /* | |
4496 | * reset the NMI-timeout, listing all files on a slow | |
25985edc | 4497 | * console might take a lot of time: |
1da177e4 LT |
4498 | */ |
4499 | touch_nmi_watchdog(); | |
39bc89fd | 4500 | if (!state_filter || (p->state & state_filter)) |
82a1fcb9 | 4501 | sched_show_task(p); |
1da177e4 LT |
4502 | } while_each_thread(g, p); |
4503 | ||
04c9167f JF |
4504 | touch_all_softlockup_watchdogs(); |
4505 | ||
dd41f596 IM |
4506 | #ifdef CONFIG_SCHED_DEBUG |
4507 | sysrq_sched_debug_show(); | |
4508 | #endif | |
510f5acc | 4509 | rcu_read_unlock(); |
e59e2ae2 IM |
4510 | /* |
4511 | * Only show locks if all tasks are dumped: | |
4512 | */ | |
93335a21 | 4513 | if (!state_filter) |
e59e2ae2 | 4514 | debug_show_all_locks(); |
1da177e4 LT |
4515 | } |
4516 | ||
0db0628d | 4517 | void init_idle_bootup_task(struct task_struct *idle) |
1df21055 | 4518 | { |
dd41f596 | 4519 | idle->sched_class = &idle_sched_class; |
1df21055 IM |
4520 | } |
4521 | ||
f340c0d1 IM |
4522 | /** |
4523 | * init_idle - set up an idle thread for a given CPU | |
4524 | * @idle: task in question | |
4525 | * @cpu: cpu the idle task belongs to | |
4526 | * | |
4527 | * NOTE: this function does not set the idle thread's NEED_RESCHED | |
4528 | * flag, to make booting more robust. | |
4529 | */ | |
0db0628d | 4530 | void init_idle(struct task_struct *idle, int cpu) |
1da177e4 | 4531 | { |
70b97a7f | 4532 | struct rq *rq = cpu_rq(cpu); |
1da177e4 LT |
4533 | unsigned long flags; |
4534 | ||
05fa785c | 4535 | raw_spin_lock_irqsave(&rq->lock, flags); |
5cbd54ef | 4536 | |
5e1576ed | 4537 | __sched_fork(0, idle); |
06b83b5f | 4538 | idle->state = TASK_RUNNING; |
dd41f596 IM |
4539 | idle->se.exec_start = sched_clock(); |
4540 | ||
1e1b6c51 | 4541 | do_set_cpus_allowed(idle, cpumask_of(cpu)); |
6506cf6c PZ |
4542 | /* |
4543 | * We're having a chicken and egg problem, even though we are | |
4544 | * holding rq->lock, the cpu isn't yet set to this cpu so the | |
4545 | * lockdep check in task_group() will fail. | |
4546 | * | |
4547 | * Similar case to sched_fork(). / Alternatively we could | |
4548 | * use task_rq_lock() here and obtain the other rq->lock. | |
4549 | * | |
4550 | * Silence PROVE_RCU | |
4551 | */ | |
4552 | rcu_read_lock(); | |
dd41f596 | 4553 | __set_task_cpu(idle, cpu); |
6506cf6c | 4554 | rcu_read_unlock(); |
1da177e4 | 4555 | |
1da177e4 | 4556 | rq->curr = rq->idle = idle; |
77177856 | 4557 | idle->on_rq = 1; |
3ca7a440 PZ |
4558 | #if defined(CONFIG_SMP) |
4559 | idle->on_cpu = 1; | |
4866cde0 | 4560 | #endif |
05fa785c | 4561 | raw_spin_unlock_irqrestore(&rq->lock, flags); |
1da177e4 LT |
4562 | |
4563 | /* Set the preempt count _outside_ the spinlocks! */ | |
01028747 | 4564 | init_idle_preempt_count(idle, cpu); |
55cd5340 | 4565 | |
dd41f596 IM |
4566 | /* |
4567 | * The idle tasks have their own, simple scheduling class: | |
4568 | */ | |
4569 | idle->sched_class = &idle_sched_class; | |
868baf07 | 4570 | ftrace_graph_init_idle_task(idle, cpu); |
45eacc69 | 4571 | vtime_init_idle(idle, cpu); |
f1c6f1a7 CE |
4572 | #if defined(CONFIG_SMP) |
4573 | sprintf(idle->comm, "%s/%d", INIT_TASK_COMM, cpu); | |
4574 | #endif | |
19978ca6 IM |
4575 | } |
4576 | ||
1da177e4 | 4577 | #ifdef CONFIG_SMP |
1e1b6c51 KM |
4578 | void do_set_cpus_allowed(struct task_struct *p, const struct cpumask *new_mask) |
4579 | { | |
4580 | if (p->sched_class && p->sched_class->set_cpus_allowed) | |
4581 | p->sched_class->set_cpus_allowed(p, new_mask); | |
4939602a PZ |
4582 | |
4583 | cpumask_copy(&p->cpus_allowed, new_mask); | |
29baa747 | 4584 | p->nr_cpus_allowed = cpumask_weight(new_mask); |
1e1b6c51 KM |
4585 | } |
4586 | ||
1da177e4 LT |
4587 | /* |
4588 | * This is how migration works: | |
4589 | * | |
969c7921 TH |
4590 | * 1) we invoke migration_cpu_stop() on the target CPU using |
4591 | * stop_one_cpu(). | |
4592 | * 2) stopper starts to run (implicitly forcing the migrated thread | |
4593 | * off the CPU) | |
4594 | * 3) it checks whether the migrated task is still in the wrong runqueue. | |
4595 | * 4) if it's in the wrong runqueue then the migration thread removes | |
1da177e4 | 4596 | * it and puts it into the right queue. |
969c7921 TH |
4597 | * 5) stopper completes and stop_one_cpu() returns and the migration |
4598 | * is done. | |
1da177e4 LT |
4599 | */ |
4600 | ||
4601 | /* | |
4602 | * Change a given task's CPU affinity. Migrate the thread to a | |
4603 | * proper CPU and schedule it away if the CPU it's executing on | |
4604 | * is removed from the allowed bitmask. | |
4605 | * | |
4606 | * NOTE: the caller must have a valid reference to the task, the | |
41a2d6cf | 4607 | * task must not exit() & deallocate itself prematurely. The |
1da177e4 LT |
4608 | * call is not atomic; no spinlocks may be held. |
4609 | */ | |
96f874e2 | 4610 | int set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask) |
1da177e4 LT |
4611 | { |
4612 | unsigned long flags; | |
70b97a7f | 4613 | struct rq *rq; |
969c7921 | 4614 | unsigned int dest_cpu; |
48f24c4d | 4615 | int ret = 0; |
1da177e4 LT |
4616 | |
4617 | rq = task_rq_lock(p, &flags); | |
e2912009 | 4618 | |
db44fc01 YZ |
4619 | if (cpumask_equal(&p->cpus_allowed, new_mask)) |
4620 | goto out; | |
4621 | ||
6ad4c188 | 4622 | if (!cpumask_intersects(new_mask, cpu_active_mask)) { |
1da177e4 LT |
4623 | ret = -EINVAL; |
4624 | goto out; | |
4625 | } | |
4626 | ||
1e1b6c51 | 4627 | do_set_cpus_allowed(p, new_mask); |
73fe6aae | 4628 | |
1da177e4 | 4629 | /* Can the task run on the task's current CPU? If so, we're done */ |
96f874e2 | 4630 | if (cpumask_test_cpu(task_cpu(p), new_mask)) |
1da177e4 LT |
4631 | goto out; |
4632 | ||
969c7921 | 4633 | dest_cpu = cpumask_any_and(cpu_active_mask, new_mask); |
bd8e7dde | 4634 | if (p->on_rq) { |
969c7921 | 4635 | struct migration_arg arg = { p, dest_cpu }; |
1da177e4 | 4636 | /* Need help from migration thread: drop lock and wait. */ |
0122ec5b | 4637 | task_rq_unlock(rq, p, &flags); |
969c7921 | 4638 | stop_one_cpu(cpu_of(rq), migration_cpu_stop, &arg); |
1da177e4 LT |
4639 | tlb_migrate_finish(p->mm); |
4640 | return 0; | |
4641 | } | |
4642 | out: | |
0122ec5b | 4643 | task_rq_unlock(rq, p, &flags); |
48f24c4d | 4644 | |
1da177e4 LT |
4645 | return ret; |
4646 | } | |
cd8ba7cd | 4647 | EXPORT_SYMBOL_GPL(set_cpus_allowed_ptr); |
1da177e4 LT |
4648 | |
4649 | /* | |
41a2d6cf | 4650 | * Move (not current) task off this cpu, onto dest cpu. We're doing |
1da177e4 LT |
4651 | * this because either it can't run here any more (set_cpus_allowed() |
4652 | * away from this CPU, or CPU going down), or because we're | |
4653 | * attempting to rebalance this task on exec (sched_exec). | |
4654 | * | |
4655 | * So we race with normal scheduler movements, but that's OK, as long | |
4656 | * as the task is no longer on this CPU. | |
efc30814 KK |
4657 | * |
4658 | * Returns non-zero if task was successfully migrated. | |
1da177e4 | 4659 | */ |
efc30814 | 4660 | static int __migrate_task(struct task_struct *p, int src_cpu, int dest_cpu) |
1da177e4 | 4661 | { |
70b97a7f | 4662 | struct rq *rq_dest, *rq_src; |
e2912009 | 4663 | int ret = 0; |
1da177e4 | 4664 | |
e761b772 | 4665 | if (unlikely(!cpu_active(dest_cpu))) |
efc30814 | 4666 | return ret; |
1da177e4 LT |
4667 | |
4668 | rq_src = cpu_rq(src_cpu); | |
4669 | rq_dest = cpu_rq(dest_cpu); | |
4670 | ||
0122ec5b | 4671 | raw_spin_lock(&p->pi_lock); |
1da177e4 LT |
4672 | double_rq_lock(rq_src, rq_dest); |
4673 | /* Already moved. */ | |
4674 | if (task_cpu(p) != src_cpu) | |
b1e38734 | 4675 | goto done; |
1da177e4 | 4676 | /* Affinity changed (again). */ |
fa17b507 | 4677 | if (!cpumask_test_cpu(dest_cpu, tsk_cpus_allowed(p))) |
b1e38734 | 4678 | goto fail; |
1da177e4 | 4679 | |
e2912009 PZ |
4680 | /* |
4681 | * If we're not on a rq, the next wake-up will ensure we're | |
4682 | * placed properly. | |
4683 | */ | |
fd2f4419 | 4684 | if (p->on_rq) { |
4ca9b72b | 4685 | dequeue_task(rq_src, p, 0); |
e2912009 | 4686 | set_task_cpu(p, dest_cpu); |
4ca9b72b | 4687 | enqueue_task(rq_dest, p, 0); |
15afe09b | 4688 | check_preempt_curr(rq_dest, p, 0); |
1da177e4 | 4689 | } |
b1e38734 | 4690 | done: |
efc30814 | 4691 | ret = 1; |
b1e38734 | 4692 | fail: |
1da177e4 | 4693 | double_rq_unlock(rq_src, rq_dest); |
0122ec5b | 4694 | raw_spin_unlock(&p->pi_lock); |
efc30814 | 4695 | return ret; |
1da177e4 LT |
4696 | } |
4697 | ||
e6628d5b MG |
4698 | #ifdef CONFIG_NUMA_BALANCING |
4699 | /* Migrate current task p to target_cpu */ | |
4700 | int migrate_task_to(struct task_struct *p, int target_cpu) | |
4701 | { | |
4702 | struct migration_arg arg = { p, target_cpu }; | |
4703 | int curr_cpu = task_cpu(p); | |
4704 | ||
4705 | if (curr_cpu == target_cpu) | |
4706 | return 0; | |
4707 | ||
4708 | if (!cpumask_test_cpu(target_cpu, tsk_cpus_allowed(p))) | |
4709 | return -EINVAL; | |
4710 | ||
4711 | /* TODO: This is not properly updating schedstats */ | |
4712 | ||
286549dc | 4713 | trace_sched_move_numa(p, curr_cpu, target_cpu); |
e6628d5b MG |
4714 | return stop_one_cpu(curr_cpu, migration_cpu_stop, &arg); |
4715 | } | |
0ec8aa00 PZ |
4716 | |
4717 | /* | |
4718 | * Requeue a task on a given node and accurately track the number of NUMA | |
4719 | * tasks on the runqueues | |
4720 | */ | |
4721 | void sched_setnuma(struct task_struct *p, int nid) | |
4722 | { | |
4723 | struct rq *rq; | |
4724 | unsigned long flags; | |
4725 | bool on_rq, running; | |
4726 | ||
4727 | rq = task_rq_lock(p, &flags); | |
4728 | on_rq = p->on_rq; | |
4729 | running = task_current(rq, p); | |
4730 | ||
4731 | if (on_rq) | |
4732 | dequeue_task(rq, p, 0); | |
4733 | if (running) | |
4734 | p->sched_class->put_prev_task(rq, p); | |
4735 | ||
4736 | p->numa_preferred_nid = nid; | |
0ec8aa00 PZ |
4737 | |
4738 | if (running) | |
4739 | p->sched_class->set_curr_task(rq); | |
4740 | if (on_rq) | |
4741 | enqueue_task(rq, p, 0); | |
4742 | task_rq_unlock(rq, p, &flags); | |
4743 | } | |
e6628d5b MG |
4744 | #endif |
4745 | ||
1da177e4 | 4746 | /* |
969c7921 TH |
4747 | * migration_cpu_stop - this will be executed by a highprio stopper thread |
4748 | * and performs thread migration by bumping thread off CPU then | |
4749 | * 'pushing' onto another runqueue. | |
1da177e4 | 4750 | */ |
969c7921 | 4751 | static int migration_cpu_stop(void *data) |
1da177e4 | 4752 | { |
969c7921 | 4753 | struct migration_arg *arg = data; |
f7b4cddc | 4754 | |
969c7921 TH |
4755 | /* |
4756 | * The original target cpu might have gone down and we might | |
4757 | * be on another cpu but it doesn't matter. | |
4758 | */ | |
f7b4cddc | 4759 | local_irq_disable(); |
969c7921 | 4760 | __migrate_task(arg->task, raw_smp_processor_id(), arg->dest_cpu); |
f7b4cddc | 4761 | local_irq_enable(); |
1da177e4 | 4762 | return 0; |
f7b4cddc ON |
4763 | } |
4764 | ||
1da177e4 | 4765 | #ifdef CONFIG_HOTPLUG_CPU |
48c5ccae | 4766 | |
054b9108 | 4767 | /* |
48c5ccae PZ |
4768 | * Ensures that the idle task is using init_mm right before its cpu goes |
4769 | * offline. | |
054b9108 | 4770 | */ |
48c5ccae | 4771 | void idle_task_exit(void) |
1da177e4 | 4772 | { |
48c5ccae | 4773 | struct mm_struct *mm = current->active_mm; |
e76bd8d9 | 4774 | |
48c5ccae | 4775 | BUG_ON(cpu_online(smp_processor_id())); |
e76bd8d9 | 4776 | |
a53efe5f | 4777 | if (mm != &init_mm) { |
48c5ccae | 4778 | switch_mm(mm, &init_mm, current); |
a53efe5f MS |
4779 | finish_arch_post_lock_switch(); |
4780 | } | |
48c5ccae | 4781 | mmdrop(mm); |
1da177e4 LT |
4782 | } |
4783 | ||
4784 | /* | |
5d180232 PZ |
4785 | * Since this CPU is going 'away' for a while, fold any nr_active delta |
4786 | * we might have. Assumes we're called after migrate_tasks() so that the | |
4787 | * nr_active count is stable. | |
4788 | * | |
4789 | * Also see the comment "Global load-average calculations". | |
1da177e4 | 4790 | */ |
5d180232 | 4791 | static void calc_load_migrate(struct rq *rq) |
1da177e4 | 4792 | { |
5d180232 PZ |
4793 | long delta = calc_load_fold_active(rq); |
4794 | if (delta) | |
4795 | atomic_long_add(delta, &calc_load_tasks); | |
1da177e4 LT |
4796 | } |
4797 | ||
3f1d2a31 PZ |
4798 | static void put_prev_task_fake(struct rq *rq, struct task_struct *prev) |
4799 | { | |
4800 | } | |
4801 | ||
4802 | static const struct sched_class fake_sched_class = { | |
4803 | .put_prev_task = put_prev_task_fake, | |
4804 | }; | |
4805 | ||
4806 | static struct task_struct fake_task = { | |
4807 | /* | |
4808 | * Avoid pull_{rt,dl}_task() | |
4809 | */ | |
4810 | .prio = MAX_PRIO + 1, | |
4811 | .sched_class = &fake_sched_class, | |
4812 | }; | |
4813 | ||
48f24c4d | 4814 | /* |
48c5ccae PZ |
4815 | * Migrate all tasks from the rq, sleeping tasks will be migrated by |
4816 | * try_to_wake_up()->select_task_rq(). | |
4817 | * | |
4818 | * Called with rq->lock held even though we'er in stop_machine() and | |
4819 | * there's no concurrency possible, we hold the required locks anyway | |
4820 | * because of lock validation efforts. | |
1da177e4 | 4821 | */ |
48c5ccae | 4822 | static void migrate_tasks(unsigned int dead_cpu) |
1da177e4 | 4823 | { |
70b97a7f | 4824 | struct rq *rq = cpu_rq(dead_cpu); |
48c5ccae PZ |
4825 | struct task_struct *next, *stop = rq->stop; |
4826 | int dest_cpu; | |
1da177e4 LT |
4827 | |
4828 | /* | |
48c5ccae PZ |
4829 | * Fudge the rq selection such that the below task selection loop |
4830 | * doesn't get stuck on the currently eligible stop task. | |
4831 | * | |
4832 | * We're currently inside stop_machine() and the rq is either stuck | |
4833 | * in the stop_machine_cpu_stop() loop, or we're executing this code, | |
4834 | * either way we should never end up calling schedule() until we're | |
4835 | * done here. | |
1da177e4 | 4836 | */ |
48c5ccae | 4837 | rq->stop = NULL; |
48f24c4d | 4838 | |
77bd3970 FW |
4839 | /* |
4840 | * put_prev_task() and pick_next_task() sched | |
4841 | * class method both need to have an up-to-date | |
4842 | * value of rq->clock[_task] | |
4843 | */ | |
4844 | update_rq_clock(rq); | |
4845 | ||
dd41f596 | 4846 | for ( ; ; ) { |
48c5ccae PZ |
4847 | /* |
4848 | * There's this thread running, bail when that's the only | |
4849 | * remaining thread. | |
4850 | */ | |
4851 | if (rq->nr_running == 1) | |
dd41f596 | 4852 | break; |
48c5ccae | 4853 | |
3f1d2a31 | 4854 | next = pick_next_task(rq, &fake_task); |
48c5ccae | 4855 | BUG_ON(!next); |
79c53799 | 4856 | next->sched_class->put_prev_task(rq, next); |
e692ab53 | 4857 | |
48c5ccae PZ |
4858 | /* Find suitable destination for @next, with force if needed. */ |
4859 | dest_cpu = select_fallback_rq(dead_cpu, next); | |
4860 | raw_spin_unlock(&rq->lock); | |
4861 | ||
4862 | __migrate_task(next, dead_cpu, dest_cpu); | |
4863 | ||
4864 | raw_spin_lock(&rq->lock); | |
1da177e4 | 4865 | } |
dce48a84 | 4866 | |
48c5ccae | 4867 | rq->stop = stop; |
dce48a84 | 4868 | } |
48c5ccae | 4869 | |
1da177e4 LT |
4870 | #endif /* CONFIG_HOTPLUG_CPU */ |
4871 | ||
e692ab53 NP |
4872 | #if defined(CONFIG_SCHED_DEBUG) && defined(CONFIG_SYSCTL) |
4873 | ||
4874 | static struct ctl_table sd_ctl_dir[] = { | |
e0361851 AD |
4875 | { |
4876 | .procname = "sched_domain", | |
c57baf1e | 4877 | .mode = 0555, |
e0361851 | 4878 | }, |
56992309 | 4879 | {} |
e692ab53 NP |
4880 | }; |
4881 | ||
4882 | static struct ctl_table sd_ctl_root[] = { | |
e0361851 AD |
4883 | { |
4884 | .procname = "kernel", | |
c57baf1e | 4885 | .mode = 0555, |
e0361851 AD |
4886 | .child = sd_ctl_dir, |
4887 | }, | |
56992309 | 4888 | {} |
e692ab53 NP |
4889 | }; |
4890 | ||
4891 | static struct ctl_table *sd_alloc_ctl_entry(int n) | |
4892 | { | |
4893 | struct ctl_table *entry = | |
5cf9f062 | 4894 | kcalloc(n, sizeof(struct ctl_table), GFP_KERNEL); |
e692ab53 | 4895 | |
e692ab53 NP |
4896 | return entry; |
4897 | } | |
4898 | ||
6382bc90 MM |
4899 | static void sd_free_ctl_entry(struct ctl_table **tablep) |
4900 | { | |
cd790076 | 4901 | struct ctl_table *entry; |
6382bc90 | 4902 | |
cd790076 MM |
4903 | /* |
4904 | * In the intermediate directories, both the child directory and | |
4905 | * procname are dynamically allocated and could fail but the mode | |
41a2d6cf | 4906 | * will always be set. In the lowest directory the names are |
cd790076 MM |
4907 | * static strings and all have proc handlers. |
4908 | */ | |
4909 | for (entry = *tablep; entry->mode; entry++) { | |
6382bc90 MM |
4910 | if (entry->child) |
4911 | sd_free_ctl_entry(&entry->child); | |
cd790076 MM |
4912 | if (entry->proc_handler == NULL) |
4913 | kfree(entry->procname); | |
4914 | } | |
6382bc90 MM |
4915 | |
4916 | kfree(*tablep); | |
4917 | *tablep = NULL; | |
4918 | } | |
4919 | ||
201c373e | 4920 | static int min_load_idx = 0; |
fd9b86d3 | 4921 | static int max_load_idx = CPU_LOAD_IDX_MAX-1; |
201c373e | 4922 | |
e692ab53 | 4923 | static void |
e0361851 | 4924 | set_table_entry(struct ctl_table *entry, |
e692ab53 | 4925 | const char *procname, void *data, int maxlen, |
201c373e NK |
4926 | umode_t mode, proc_handler *proc_handler, |
4927 | bool load_idx) | |
e692ab53 | 4928 | { |
e692ab53 NP |
4929 | entry->procname = procname; |
4930 | entry->data = data; | |
4931 | entry->maxlen = maxlen; | |
4932 | entry->mode = mode; | |
4933 | entry->proc_handler = proc_handler; | |
201c373e NK |
4934 | |
4935 | if (load_idx) { | |
4936 | entry->extra1 = &min_load_idx; | |
4937 | entry->extra2 = &max_load_idx; | |
4938 | } | |
e692ab53 NP |
4939 | } |
4940 | ||
4941 | static struct ctl_table * | |
4942 | sd_alloc_ctl_domain_table(struct sched_domain *sd) | |
4943 | { | |
37e6bae8 | 4944 | struct ctl_table *table = sd_alloc_ctl_entry(14); |
e692ab53 | 4945 | |
ad1cdc1d MM |
4946 | if (table == NULL) |
4947 | return NULL; | |
4948 | ||
e0361851 | 4949 | set_table_entry(&table[0], "min_interval", &sd->min_interval, |
201c373e | 4950 | sizeof(long), 0644, proc_doulongvec_minmax, false); |
e0361851 | 4951 | set_table_entry(&table[1], "max_interval", &sd->max_interval, |
201c373e | 4952 | sizeof(long), 0644, proc_doulongvec_minmax, false); |
e0361851 | 4953 | set_table_entry(&table[2], "busy_idx", &sd->busy_idx, |
201c373e | 4954 | sizeof(int), 0644, proc_dointvec_minmax, true); |
e0361851 | 4955 | set_table_entry(&table[3], "idle_idx", &sd->idle_idx, |
201c373e | 4956 | sizeof(int), 0644, proc_dointvec_minmax, true); |
e0361851 | 4957 | set_table_entry(&table[4], "newidle_idx", &sd->newidle_idx, |
201c373e | 4958 | sizeof(int), 0644, proc_dointvec_minmax, true); |
e0361851 | 4959 | set_table_entry(&table[5], "wake_idx", &sd->wake_idx, |
201c373e | 4960 | sizeof(int), 0644, proc_dointvec_minmax, true); |
e0361851 | 4961 | set_table_entry(&table[6], "forkexec_idx", &sd->forkexec_idx, |
201c373e | 4962 | sizeof(int), 0644, proc_dointvec_minmax, true); |
e0361851 | 4963 | set_table_entry(&table[7], "busy_factor", &sd->busy_factor, |
201c373e | 4964 | sizeof(int), 0644, proc_dointvec_minmax, false); |
e0361851 | 4965 | set_table_entry(&table[8], "imbalance_pct", &sd->imbalance_pct, |
201c373e | 4966 | sizeof(int), 0644, proc_dointvec_minmax, false); |
ace8b3d6 | 4967 | set_table_entry(&table[9], "cache_nice_tries", |
e692ab53 | 4968 | &sd->cache_nice_tries, |
201c373e | 4969 | sizeof(int), 0644, proc_dointvec_minmax, false); |
ace8b3d6 | 4970 | set_table_entry(&table[10], "flags", &sd->flags, |
201c373e | 4971 | sizeof(int), 0644, proc_dointvec_minmax, false); |
37e6bae8 AS |
4972 | set_table_entry(&table[11], "max_newidle_lb_cost", |
4973 | &sd->max_newidle_lb_cost, | |
4974 | sizeof(long), 0644, proc_doulongvec_minmax, false); | |
4975 | set_table_entry(&table[12], "name", sd->name, | |
201c373e | 4976 | CORENAME_MAX_SIZE, 0444, proc_dostring, false); |
37e6bae8 | 4977 | /* &table[13] is terminator */ |
e692ab53 NP |
4978 | |
4979 | return table; | |
4980 | } | |
4981 | ||
be7002e6 | 4982 | static struct ctl_table *sd_alloc_ctl_cpu_table(int cpu) |
e692ab53 NP |
4983 | { |
4984 | struct ctl_table *entry, *table; | |
4985 | struct sched_domain *sd; | |
4986 | int domain_num = 0, i; | |
4987 | char buf[32]; | |
4988 | ||
4989 | for_each_domain(cpu, sd) | |
4990 | domain_num++; | |
4991 | entry = table = sd_alloc_ctl_entry(domain_num + 1); | |
ad1cdc1d MM |
4992 | if (table == NULL) |
4993 | return NULL; | |
e692ab53 NP |
4994 | |
4995 | i = 0; | |
4996 | for_each_domain(cpu, sd) { | |
4997 | snprintf(buf, 32, "domain%d", i); | |
e692ab53 | 4998 | entry->procname = kstrdup(buf, GFP_KERNEL); |
c57baf1e | 4999 | entry->mode = 0555; |
e692ab53 NP |
5000 | entry->child = sd_alloc_ctl_domain_table(sd); |
5001 | entry++; | |
5002 | i++; | |
5003 | } | |
5004 | return table; | |
5005 | } | |
5006 | ||
5007 | static struct ctl_table_header *sd_sysctl_header; | |
6382bc90 | 5008 | static void register_sched_domain_sysctl(void) |
e692ab53 | 5009 | { |
6ad4c188 | 5010 | int i, cpu_num = num_possible_cpus(); |
e692ab53 NP |
5011 | struct ctl_table *entry = sd_alloc_ctl_entry(cpu_num + 1); |
5012 | char buf[32]; | |
5013 | ||
7378547f MM |
5014 | WARN_ON(sd_ctl_dir[0].child); |
5015 | sd_ctl_dir[0].child = entry; | |
5016 | ||
ad1cdc1d MM |
5017 | if (entry == NULL) |
5018 | return; | |
5019 | ||
6ad4c188 | 5020 | for_each_possible_cpu(i) { |
e692ab53 | 5021 | snprintf(buf, 32, "cpu%d", i); |
e692ab53 | 5022 | entry->procname = kstrdup(buf, GFP_KERNEL); |
c57baf1e | 5023 | entry->mode = 0555; |
e692ab53 | 5024 | entry->child = sd_alloc_ctl_cpu_table(i); |
97b6ea7b | 5025 | entry++; |
e692ab53 | 5026 | } |
7378547f MM |
5027 | |
5028 | WARN_ON(sd_sysctl_header); | |
e692ab53 NP |
5029 | sd_sysctl_header = register_sysctl_table(sd_ctl_root); |
5030 | } | |
6382bc90 | 5031 | |
7378547f | 5032 | /* may be called multiple times per register */ |
6382bc90 MM |
5033 | static void unregister_sched_domain_sysctl(void) |
5034 | { | |
7378547f MM |
5035 | if (sd_sysctl_header) |
5036 | unregister_sysctl_table(sd_sysctl_header); | |
6382bc90 | 5037 | sd_sysctl_header = NULL; |
7378547f MM |
5038 | if (sd_ctl_dir[0].child) |
5039 | sd_free_ctl_entry(&sd_ctl_dir[0].child); | |
6382bc90 | 5040 | } |
e692ab53 | 5041 | #else |
6382bc90 MM |
5042 | static void register_sched_domain_sysctl(void) |
5043 | { | |
5044 | } | |
5045 | static void unregister_sched_domain_sysctl(void) | |
e692ab53 NP |
5046 | { |
5047 | } | |
5048 | #endif | |
5049 | ||
1f11eb6a GH |
5050 | static void set_rq_online(struct rq *rq) |
5051 | { | |
5052 | if (!rq->online) { | |
5053 | const struct sched_class *class; | |
5054 | ||
c6c4927b | 5055 | cpumask_set_cpu(rq->cpu, rq->rd->online); |
1f11eb6a GH |
5056 | rq->online = 1; |
5057 | ||
5058 | for_each_class(class) { | |
5059 | if (class->rq_online) | |
5060 | class->rq_online(rq); | |
5061 | } | |
5062 | } | |
5063 | } | |
5064 | ||
5065 | static void set_rq_offline(struct rq *rq) | |
5066 | { | |
5067 | if (rq->online) { | |
5068 | const struct sched_class *class; | |
5069 | ||
5070 | for_each_class(class) { | |
5071 | if (class->rq_offline) | |
5072 | class->rq_offline(rq); | |
5073 | } | |
5074 | ||
c6c4927b | 5075 | cpumask_clear_cpu(rq->cpu, rq->rd->online); |
1f11eb6a GH |
5076 | rq->online = 0; |
5077 | } | |
5078 | } | |
5079 | ||
1da177e4 LT |
5080 | /* |
5081 | * migration_call - callback that gets triggered when a CPU is added. | |
5082 | * Here we can start up the necessary migration thread for the new CPU. | |
5083 | */ | |
0db0628d | 5084 | static int |
48f24c4d | 5085 | migration_call(struct notifier_block *nfb, unsigned long action, void *hcpu) |
1da177e4 | 5086 | { |
48f24c4d | 5087 | int cpu = (long)hcpu; |
1da177e4 | 5088 | unsigned long flags; |
969c7921 | 5089 | struct rq *rq = cpu_rq(cpu); |
1da177e4 | 5090 | |
48c5ccae | 5091 | switch (action & ~CPU_TASKS_FROZEN) { |
5be9361c | 5092 | |
1da177e4 | 5093 | case CPU_UP_PREPARE: |
a468d389 | 5094 | rq->calc_load_update = calc_load_update; |
1da177e4 | 5095 | break; |
48f24c4d | 5096 | |
1da177e4 | 5097 | case CPU_ONLINE: |
1f94ef59 | 5098 | /* Update our root-domain */ |
05fa785c | 5099 | raw_spin_lock_irqsave(&rq->lock, flags); |
1f94ef59 | 5100 | if (rq->rd) { |
c6c4927b | 5101 | BUG_ON(!cpumask_test_cpu(cpu, rq->rd->span)); |
1f11eb6a GH |
5102 | |
5103 | set_rq_online(rq); | |
1f94ef59 | 5104 | } |
05fa785c | 5105 | raw_spin_unlock_irqrestore(&rq->lock, flags); |
1da177e4 | 5106 | break; |
48f24c4d | 5107 | |
1da177e4 | 5108 | #ifdef CONFIG_HOTPLUG_CPU |
08f503b0 | 5109 | case CPU_DYING: |
317f3941 | 5110 | sched_ttwu_pending(); |
57d885fe | 5111 | /* Update our root-domain */ |
05fa785c | 5112 | raw_spin_lock_irqsave(&rq->lock, flags); |
57d885fe | 5113 | if (rq->rd) { |
c6c4927b | 5114 | BUG_ON(!cpumask_test_cpu(cpu, rq->rd->span)); |
1f11eb6a | 5115 | set_rq_offline(rq); |
57d885fe | 5116 | } |
48c5ccae PZ |
5117 | migrate_tasks(cpu); |
5118 | BUG_ON(rq->nr_running != 1); /* the migration thread */ | |
05fa785c | 5119 | raw_spin_unlock_irqrestore(&rq->lock, flags); |
5d180232 | 5120 | break; |
48c5ccae | 5121 | |
5d180232 | 5122 | case CPU_DEAD: |
f319da0c | 5123 | calc_load_migrate(rq); |
57d885fe | 5124 | break; |
1da177e4 LT |
5125 | #endif |
5126 | } | |
49c022e6 PZ |
5127 | |
5128 | update_max_interval(); | |
5129 | ||
1da177e4 LT |
5130 | return NOTIFY_OK; |
5131 | } | |
5132 | ||
f38b0820 PM |
5133 | /* |
5134 | * Register at high priority so that task migration (migrate_all_tasks) | |
5135 | * happens before everything else. This has to be lower priority than | |
cdd6c482 | 5136 | * the notifier in the perf_event subsystem, though. |
1da177e4 | 5137 | */ |
0db0628d | 5138 | static struct notifier_block migration_notifier = { |
1da177e4 | 5139 | .notifier_call = migration_call, |
50a323b7 | 5140 | .priority = CPU_PRI_MIGRATION, |
1da177e4 LT |
5141 | }; |
5142 | ||
a803f026 CM |
5143 | static void __cpuinit set_cpu_rq_start_time(void) |
5144 | { | |
5145 | int cpu = smp_processor_id(); | |
5146 | struct rq *rq = cpu_rq(cpu); | |
5147 | rq->age_stamp = sched_clock_cpu(cpu); | |
5148 | } | |
5149 | ||
0db0628d | 5150 | static int sched_cpu_active(struct notifier_block *nfb, |
3a101d05 TH |
5151 | unsigned long action, void *hcpu) |
5152 | { | |
5153 | switch (action & ~CPU_TASKS_FROZEN) { | |
a803f026 CM |
5154 | case CPU_STARTING: |
5155 | set_cpu_rq_start_time(); | |
5156 | return NOTIFY_OK; | |
3a101d05 TH |
5157 | case CPU_DOWN_FAILED: |
5158 | set_cpu_active((long)hcpu, true); | |
5159 | return NOTIFY_OK; | |
5160 | default: | |
5161 | return NOTIFY_DONE; | |
5162 | } | |
5163 | } | |
5164 | ||
0db0628d | 5165 | static int sched_cpu_inactive(struct notifier_block *nfb, |
3a101d05 TH |
5166 | unsigned long action, void *hcpu) |
5167 | { | |
de212f18 PZ |
5168 | unsigned long flags; |
5169 | long cpu = (long)hcpu; | |
5170 | ||
3a101d05 TH |
5171 | switch (action & ~CPU_TASKS_FROZEN) { |
5172 | case CPU_DOWN_PREPARE: | |
de212f18 PZ |
5173 | set_cpu_active(cpu, false); |
5174 | ||
5175 | /* explicitly allow suspend */ | |
5176 | if (!(action & CPU_TASKS_FROZEN)) { | |
5177 | struct dl_bw *dl_b = dl_bw_of(cpu); | |
5178 | bool overflow; | |
5179 | int cpus; | |
5180 | ||
5181 | raw_spin_lock_irqsave(&dl_b->lock, flags); | |
5182 | cpus = dl_bw_cpus(cpu); | |
5183 | overflow = __dl_overflow(dl_b, cpus, 0, 0); | |
5184 | raw_spin_unlock_irqrestore(&dl_b->lock, flags); | |
5185 | ||
5186 | if (overflow) | |
5187 | return notifier_from_errno(-EBUSY); | |
5188 | } | |
3a101d05 | 5189 | return NOTIFY_OK; |
3a101d05 | 5190 | } |
de212f18 PZ |
5191 | |
5192 | return NOTIFY_DONE; | |
3a101d05 TH |
5193 | } |
5194 | ||
7babe8db | 5195 | static int __init migration_init(void) |
1da177e4 LT |
5196 | { |
5197 | void *cpu = (void *)(long)smp_processor_id(); | |
07dccf33 | 5198 | int err; |
48f24c4d | 5199 | |
3a101d05 | 5200 | /* Initialize migration for the boot CPU */ |
07dccf33 AM |
5201 | err = migration_call(&migration_notifier, CPU_UP_PREPARE, cpu); |
5202 | BUG_ON(err == NOTIFY_BAD); | |
1da177e4 LT |
5203 | migration_call(&migration_notifier, CPU_ONLINE, cpu); |
5204 | register_cpu_notifier(&migration_notifier); | |
7babe8db | 5205 | |
3a101d05 TH |
5206 | /* Register cpu active notifiers */ |
5207 | cpu_notifier(sched_cpu_active, CPU_PRI_SCHED_ACTIVE); | |
5208 | cpu_notifier(sched_cpu_inactive, CPU_PRI_SCHED_INACTIVE); | |
5209 | ||
a004cd42 | 5210 | return 0; |
1da177e4 | 5211 | } |
7babe8db | 5212 | early_initcall(migration_init); |
1da177e4 LT |
5213 | #endif |
5214 | ||
5215 | #ifdef CONFIG_SMP | |
476f3534 | 5216 | |
4cb98839 PZ |
5217 | static cpumask_var_t sched_domains_tmpmask; /* sched_domains_mutex */ |
5218 | ||
3e9830dc | 5219 | #ifdef CONFIG_SCHED_DEBUG |
4dcf6aff | 5220 | |
d039ac60 | 5221 | static __read_mostly int sched_debug_enabled; |
f6630114 | 5222 | |
d039ac60 | 5223 | static int __init sched_debug_setup(char *str) |
f6630114 | 5224 | { |
d039ac60 | 5225 | sched_debug_enabled = 1; |
f6630114 MT |
5226 | |
5227 | return 0; | |
5228 | } | |
d039ac60 PZ |
5229 | early_param("sched_debug", sched_debug_setup); |
5230 | ||
5231 | static inline bool sched_debug(void) | |
5232 | { | |
5233 | return sched_debug_enabled; | |
5234 | } | |
f6630114 | 5235 | |
7c16ec58 | 5236 | static int sched_domain_debug_one(struct sched_domain *sd, int cpu, int level, |
96f874e2 | 5237 | struct cpumask *groupmask) |
1da177e4 | 5238 | { |
4dcf6aff | 5239 | struct sched_group *group = sd->groups; |
434d53b0 | 5240 | char str[256]; |
1da177e4 | 5241 | |
968ea6d8 | 5242 | cpulist_scnprintf(str, sizeof(str), sched_domain_span(sd)); |
96f874e2 | 5243 | cpumask_clear(groupmask); |
4dcf6aff IM |
5244 | |
5245 | printk(KERN_DEBUG "%*s domain %d: ", level, "", level); | |
5246 | ||
5247 | if (!(sd->flags & SD_LOAD_BALANCE)) { | |
3df0fc5b | 5248 | printk("does not load-balance\n"); |
4dcf6aff | 5249 | if (sd->parent) |
3df0fc5b PZ |
5250 | printk(KERN_ERR "ERROR: !SD_LOAD_BALANCE domain" |
5251 | " has parent"); | |
4dcf6aff | 5252 | return -1; |
41c7ce9a NP |
5253 | } |
5254 | ||
3df0fc5b | 5255 | printk(KERN_CONT "span %s level %s\n", str, sd->name); |
4dcf6aff | 5256 | |
758b2cdc | 5257 | if (!cpumask_test_cpu(cpu, sched_domain_span(sd))) { |
3df0fc5b PZ |
5258 | printk(KERN_ERR "ERROR: domain->span does not contain " |
5259 | "CPU%d\n", cpu); | |
4dcf6aff | 5260 | } |
758b2cdc | 5261 | if (!cpumask_test_cpu(cpu, sched_group_cpus(group))) { |
3df0fc5b PZ |
5262 | printk(KERN_ERR "ERROR: domain->groups does not contain" |
5263 | " CPU%d\n", cpu); | |
4dcf6aff | 5264 | } |
1da177e4 | 5265 | |
4dcf6aff | 5266 | printk(KERN_DEBUG "%*s groups:", level + 1, ""); |
1da177e4 | 5267 | do { |
4dcf6aff | 5268 | if (!group) { |
3df0fc5b PZ |
5269 | printk("\n"); |
5270 | printk(KERN_ERR "ERROR: group is NULL\n"); | |
1da177e4 LT |
5271 | break; |
5272 | } | |
5273 | ||
c3decf0d | 5274 | /* |
63b2ca30 NP |
5275 | * Even though we initialize ->capacity to something semi-sane, |
5276 | * we leave capacity_orig unset. This allows us to detect if | |
c3decf0d PZ |
5277 | * domain iteration is still funny without causing /0 traps. |
5278 | */ | |
63b2ca30 | 5279 | if (!group->sgc->capacity_orig) { |
3df0fc5b | 5280 | printk(KERN_CONT "\n"); |
63b2ca30 | 5281 | printk(KERN_ERR "ERROR: domain->cpu_capacity not set\n"); |
4dcf6aff IM |
5282 | break; |
5283 | } | |
1da177e4 | 5284 | |
758b2cdc | 5285 | if (!cpumask_weight(sched_group_cpus(group))) { |
3df0fc5b PZ |
5286 | printk(KERN_CONT "\n"); |
5287 | printk(KERN_ERR "ERROR: empty group\n"); | |
4dcf6aff IM |
5288 | break; |
5289 | } | |
1da177e4 | 5290 | |
cb83b629 PZ |
5291 | if (!(sd->flags & SD_OVERLAP) && |
5292 | cpumask_intersects(groupmask, sched_group_cpus(group))) { | |
3df0fc5b PZ |
5293 | printk(KERN_CONT "\n"); |
5294 | printk(KERN_ERR "ERROR: repeated CPUs\n"); | |
4dcf6aff IM |
5295 | break; |
5296 | } | |
1da177e4 | 5297 | |
758b2cdc | 5298 | cpumask_or(groupmask, groupmask, sched_group_cpus(group)); |
1da177e4 | 5299 | |
968ea6d8 | 5300 | cpulist_scnprintf(str, sizeof(str), sched_group_cpus(group)); |
381512cf | 5301 | |
3df0fc5b | 5302 | printk(KERN_CONT " %s", str); |
ca8ce3d0 | 5303 | if (group->sgc->capacity != SCHED_CAPACITY_SCALE) { |
63b2ca30 NP |
5304 | printk(KERN_CONT " (cpu_capacity = %d)", |
5305 | group->sgc->capacity); | |
381512cf | 5306 | } |
1da177e4 | 5307 | |
4dcf6aff IM |
5308 | group = group->next; |
5309 | } while (group != sd->groups); | |
3df0fc5b | 5310 | printk(KERN_CONT "\n"); |
1da177e4 | 5311 | |
758b2cdc | 5312 | if (!cpumask_equal(sched_domain_span(sd), groupmask)) |
3df0fc5b | 5313 | printk(KERN_ERR "ERROR: groups don't span domain->span\n"); |
1da177e4 | 5314 | |
758b2cdc RR |
5315 | if (sd->parent && |
5316 | !cpumask_subset(groupmask, sched_domain_span(sd->parent))) | |
3df0fc5b PZ |
5317 | printk(KERN_ERR "ERROR: parent span is not a superset " |
5318 | "of domain->span\n"); | |
4dcf6aff IM |
5319 | return 0; |
5320 | } | |
1da177e4 | 5321 | |
4dcf6aff IM |
5322 | static void sched_domain_debug(struct sched_domain *sd, int cpu) |
5323 | { | |
5324 | int level = 0; | |
1da177e4 | 5325 | |
d039ac60 | 5326 | if (!sched_debug_enabled) |
f6630114 MT |
5327 | return; |
5328 | ||
4dcf6aff IM |
5329 | if (!sd) { |
5330 | printk(KERN_DEBUG "CPU%d attaching NULL sched-domain.\n", cpu); | |
5331 | return; | |
5332 | } | |
1da177e4 | 5333 | |
4dcf6aff IM |
5334 | printk(KERN_DEBUG "CPU%d attaching sched-domain:\n", cpu); |
5335 | ||
5336 | for (;;) { | |
4cb98839 | 5337 | if (sched_domain_debug_one(sd, cpu, level, sched_domains_tmpmask)) |
4dcf6aff | 5338 | break; |
1da177e4 LT |
5339 | level++; |
5340 | sd = sd->parent; | |
33859f7f | 5341 | if (!sd) |
4dcf6aff IM |
5342 | break; |
5343 | } | |
1da177e4 | 5344 | } |
6d6bc0ad | 5345 | #else /* !CONFIG_SCHED_DEBUG */ |
48f24c4d | 5346 | # define sched_domain_debug(sd, cpu) do { } while (0) |
d039ac60 PZ |
5347 | static inline bool sched_debug(void) |
5348 | { | |
5349 | return false; | |
5350 | } | |
6d6bc0ad | 5351 | #endif /* CONFIG_SCHED_DEBUG */ |
1da177e4 | 5352 | |
1a20ff27 | 5353 | static int sd_degenerate(struct sched_domain *sd) |
245af2c7 | 5354 | { |
758b2cdc | 5355 | if (cpumask_weight(sched_domain_span(sd)) == 1) |
245af2c7 SS |
5356 | return 1; |
5357 | ||
5358 | /* Following flags need at least 2 groups */ | |
5359 | if (sd->flags & (SD_LOAD_BALANCE | | |
5360 | SD_BALANCE_NEWIDLE | | |
5361 | SD_BALANCE_FORK | | |
89c4710e | 5362 | SD_BALANCE_EXEC | |
5d4dfddd | 5363 | SD_SHARE_CPUCAPACITY | |
d77b3ed5 VG |
5364 | SD_SHARE_PKG_RESOURCES | |
5365 | SD_SHARE_POWERDOMAIN)) { | |
245af2c7 SS |
5366 | if (sd->groups != sd->groups->next) |
5367 | return 0; | |
5368 | } | |
5369 | ||
5370 | /* Following flags don't use groups */ | |
c88d5910 | 5371 | if (sd->flags & (SD_WAKE_AFFINE)) |
245af2c7 SS |
5372 | return 0; |
5373 | ||
5374 | return 1; | |
5375 | } | |
5376 | ||
48f24c4d IM |
5377 | static int |
5378 | sd_parent_degenerate(struct sched_domain *sd, struct sched_domain *parent) | |
245af2c7 SS |
5379 | { |
5380 | unsigned long cflags = sd->flags, pflags = parent->flags; | |
5381 | ||
5382 | if (sd_degenerate(parent)) | |
5383 | return 1; | |
5384 | ||
758b2cdc | 5385 | if (!cpumask_equal(sched_domain_span(sd), sched_domain_span(parent))) |
245af2c7 SS |
5386 | return 0; |
5387 | ||
245af2c7 SS |
5388 | /* Flags needing groups don't count if only 1 group in parent */ |
5389 | if (parent->groups == parent->groups->next) { | |
5390 | pflags &= ~(SD_LOAD_BALANCE | | |
5391 | SD_BALANCE_NEWIDLE | | |
5392 | SD_BALANCE_FORK | | |
89c4710e | 5393 | SD_BALANCE_EXEC | |
5d4dfddd | 5394 | SD_SHARE_CPUCAPACITY | |
10866e62 | 5395 | SD_SHARE_PKG_RESOURCES | |
d77b3ed5 VG |
5396 | SD_PREFER_SIBLING | |
5397 | SD_SHARE_POWERDOMAIN); | |
5436499e KC |
5398 | if (nr_node_ids == 1) |
5399 | pflags &= ~SD_SERIALIZE; | |
245af2c7 SS |
5400 | } |
5401 | if (~cflags & pflags) | |
5402 | return 0; | |
5403 | ||
5404 | return 1; | |
5405 | } | |
5406 | ||
dce840a0 | 5407 | static void free_rootdomain(struct rcu_head *rcu) |
c6c4927b | 5408 | { |
dce840a0 | 5409 | struct root_domain *rd = container_of(rcu, struct root_domain, rcu); |
047106ad | 5410 | |
68e74568 | 5411 | cpupri_cleanup(&rd->cpupri); |
6bfd6d72 | 5412 | cpudl_cleanup(&rd->cpudl); |
1baca4ce | 5413 | free_cpumask_var(rd->dlo_mask); |
c6c4927b RR |
5414 | free_cpumask_var(rd->rto_mask); |
5415 | free_cpumask_var(rd->online); | |
5416 | free_cpumask_var(rd->span); | |
5417 | kfree(rd); | |
5418 | } | |
5419 | ||
57d885fe GH |
5420 | static void rq_attach_root(struct rq *rq, struct root_domain *rd) |
5421 | { | |
a0490fa3 | 5422 | struct root_domain *old_rd = NULL; |
57d885fe | 5423 | unsigned long flags; |
57d885fe | 5424 | |
05fa785c | 5425 | raw_spin_lock_irqsave(&rq->lock, flags); |
57d885fe GH |
5426 | |
5427 | if (rq->rd) { | |
a0490fa3 | 5428 | old_rd = rq->rd; |
57d885fe | 5429 | |
c6c4927b | 5430 | if (cpumask_test_cpu(rq->cpu, old_rd->online)) |
1f11eb6a | 5431 | set_rq_offline(rq); |
57d885fe | 5432 | |
c6c4927b | 5433 | cpumask_clear_cpu(rq->cpu, old_rd->span); |
dc938520 | 5434 | |
a0490fa3 | 5435 | /* |
0515973f | 5436 | * If we dont want to free the old_rd yet then |
a0490fa3 IM |
5437 | * set old_rd to NULL to skip the freeing later |
5438 | * in this function: | |
5439 | */ | |
5440 | if (!atomic_dec_and_test(&old_rd->refcount)) | |
5441 | old_rd = NULL; | |
57d885fe GH |
5442 | } |
5443 | ||
5444 | atomic_inc(&rd->refcount); | |
5445 | rq->rd = rd; | |
5446 | ||
c6c4927b | 5447 | cpumask_set_cpu(rq->cpu, rd->span); |
00aec93d | 5448 | if (cpumask_test_cpu(rq->cpu, cpu_active_mask)) |
1f11eb6a | 5449 | set_rq_online(rq); |
57d885fe | 5450 | |
05fa785c | 5451 | raw_spin_unlock_irqrestore(&rq->lock, flags); |
a0490fa3 IM |
5452 | |
5453 | if (old_rd) | |
dce840a0 | 5454 | call_rcu_sched(&old_rd->rcu, free_rootdomain); |
57d885fe GH |
5455 | } |
5456 | ||
68c38fc3 | 5457 | static int init_rootdomain(struct root_domain *rd) |
57d885fe GH |
5458 | { |
5459 | memset(rd, 0, sizeof(*rd)); | |
5460 | ||
68c38fc3 | 5461 | if (!alloc_cpumask_var(&rd->span, GFP_KERNEL)) |
0c910d28 | 5462 | goto out; |
68c38fc3 | 5463 | if (!alloc_cpumask_var(&rd->online, GFP_KERNEL)) |
c6c4927b | 5464 | goto free_span; |
1baca4ce | 5465 | if (!alloc_cpumask_var(&rd->dlo_mask, GFP_KERNEL)) |
c6c4927b | 5466 | goto free_online; |
1baca4ce JL |
5467 | if (!alloc_cpumask_var(&rd->rto_mask, GFP_KERNEL)) |
5468 | goto free_dlo_mask; | |
6e0534f2 | 5469 | |
332ac17e | 5470 | init_dl_bw(&rd->dl_bw); |
6bfd6d72 JL |
5471 | if (cpudl_init(&rd->cpudl) != 0) |
5472 | goto free_dlo_mask; | |
332ac17e | 5473 | |
68c38fc3 | 5474 | if (cpupri_init(&rd->cpupri) != 0) |
68e74568 | 5475 | goto free_rto_mask; |
c6c4927b | 5476 | return 0; |
6e0534f2 | 5477 | |
68e74568 RR |
5478 | free_rto_mask: |
5479 | free_cpumask_var(rd->rto_mask); | |
1baca4ce JL |
5480 | free_dlo_mask: |
5481 | free_cpumask_var(rd->dlo_mask); | |
c6c4927b RR |
5482 | free_online: |
5483 | free_cpumask_var(rd->online); | |
5484 | free_span: | |
5485 | free_cpumask_var(rd->span); | |
0c910d28 | 5486 | out: |
c6c4927b | 5487 | return -ENOMEM; |
57d885fe GH |
5488 | } |
5489 | ||
029632fb PZ |
5490 | /* |
5491 | * By default the system creates a single root-domain with all cpus as | |
5492 | * members (mimicking the global state we have today). | |
5493 | */ | |
5494 | struct root_domain def_root_domain; | |
5495 | ||
57d885fe GH |
5496 | static void init_defrootdomain(void) |
5497 | { | |
68c38fc3 | 5498 | init_rootdomain(&def_root_domain); |
c6c4927b | 5499 | |
57d885fe GH |
5500 | atomic_set(&def_root_domain.refcount, 1); |
5501 | } | |
5502 | ||
dc938520 | 5503 | static struct root_domain *alloc_rootdomain(void) |
57d885fe GH |
5504 | { |
5505 | struct root_domain *rd; | |
5506 | ||
5507 | rd = kmalloc(sizeof(*rd), GFP_KERNEL); | |
5508 | if (!rd) | |
5509 | return NULL; | |
5510 | ||
68c38fc3 | 5511 | if (init_rootdomain(rd) != 0) { |
c6c4927b RR |
5512 | kfree(rd); |
5513 | return NULL; | |
5514 | } | |
57d885fe GH |
5515 | |
5516 | return rd; | |
5517 | } | |
5518 | ||
63b2ca30 | 5519 | static void free_sched_groups(struct sched_group *sg, int free_sgc) |
e3589f6c PZ |
5520 | { |
5521 | struct sched_group *tmp, *first; | |
5522 | ||
5523 | if (!sg) | |
5524 | return; | |
5525 | ||
5526 | first = sg; | |
5527 | do { | |
5528 | tmp = sg->next; | |
5529 | ||
63b2ca30 NP |
5530 | if (free_sgc && atomic_dec_and_test(&sg->sgc->ref)) |
5531 | kfree(sg->sgc); | |
e3589f6c PZ |
5532 | |
5533 | kfree(sg); | |
5534 | sg = tmp; | |
5535 | } while (sg != first); | |
5536 | } | |
5537 | ||
dce840a0 PZ |
5538 | static void free_sched_domain(struct rcu_head *rcu) |
5539 | { | |
5540 | struct sched_domain *sd = container_of(rcu, struct sched_domain, rcu); | |
e3589f6c PZ |
5541 | |
5542 | /* | |
5543 | * If its an overlapping domain it has private groups, iterate and | |
5544 | * nuke them all. | |
5545 | */ | |
5546 | if (sd->flags & SD_OVERLAP) { | |
5547 | free_sched_groups(sd->groups, 1); | |
5548 | } else if (atomic_dec_and_test(&sd->groups->ref)) { | |
63b2ca30 | 5549 | kfree(sd->groups->sgc); |
dce840a0 | 5550 | kfree(sd->groups); |
9c3f75cb | 5551 | } |
dce840a0 PZ |
5552 | kfree(sd); |
5553 | } | |
5554 | ||
5555 | static void destroy_sched_domain(struct sched_domain *sd, int cpu) | |
5556 | { | |
5557 | call_rcu(&sd->rcu, free_sched_domain); | |
5558 | } | |
5559 | ||
5560 | static void destroy_sched_domains(struct sched_domain *sd, int cpu) | |
5561 | { | |
5562 | for (; sd; sd = sd->parent) | |
5563 | destroy_sched_domain(sd, cpu); | |
5564 | } | |
5565 | ||
518cd623 PZ |
5566 | /* |
5567 | * Keep a special pointer to the highest sched_domain that has | |
5568 | * SD_SHARE_PKG_RESOURCE set (Last Level Cache Domain) for this | |
5569 | * allows us to avoid some pointer chasing select_idle_sibling(). | |
5570 | * | |
5571 | * Also keep a unique ID per domain (we use the first cpu number in | |
5572 | * the cpumask of the domain), this allows us to quickly tell if | |
39be3501 | 5573 | * two cpus are in the same cache domain, see cpus_share_cache(). |
518cd623 PZ |
5574 | */ |
5575 | DEFINE_PER_CPU(struct sched_domain *, sd_llc); | |
7d9ffa89 | 5576 | DEFINE_PER_CPU(int, sd_llc_size); |
518cd623 | 5577 | DEFINE_PER_CPU(int, sd_llc_id); |
fb13c7ee | 5578 | DEFINE_PER_CPU(struct sched_domain *, sd_numa); |
37dc6b50 PM |
5579 | DEFINE_PER_CPU(struct sched_domain *, sd_busy); |
5580 | DEFINE_PER_CPU(struct sched_domain *, sd_asym); | |
518cd623 PZ |
5581 | |
5582 | static void update_top_cache_domain(int cpu) | |
5583 | { | |
5584 | struct sched_domain *sd; | |
5d4cf996 | 5585 | struct sched_domain *busy_sd = NULL; |
518cd623 | 5586 | int id = cpu; |
7d9ffa89 | 5587 | int size = 1; |
518cd623 PZ |
5588 | |
5589 | sd = highest_flag_domain(cpu, SD_SHARE_PKG_RESOURCES); | |
7d9ffa89 | 5590 | if (sd) { |
518cd623 | 5591 | id = cpumask_first(sched_domain_span(sd)); |
7d9ffa89 | 5592 | size = cpumask_weight(sched_domain_span(sd)); |
5d4cf996 | 5593 | busy_sd = sd->parent; /* sd_busy */ |
7d9ffa89 | 5594 | } |
5d4cf996 | 5595 | rcu_assign_pointer(per_cpu(sd_busy, cpu), busy_sd); |
518cd623 PZ |
5596 | |
5597 | rcu_assign_pointer(per_cpu(sd_llc, cpu), sd); | |
7d9ffa89 | 5598 | per_cpu(sd_llc_size, cpu) = size; |
518cd623 | 5599 | per_cpu(sd_llc_id, cpu) = id; |
fb13c7ee MG |
5600 | |
5601 | sd = lowest_flag_domain(cpu, SD_NUMA); | |
5602 | rcu_assign_pointer(per_cpu(sd_numa, cpu), sd); | |
37dc6b50 PM |
5603 | |
5604 | sd = highest_flag_domain(cpu, SD_ASYM_PACKING); | |
5605 | rcu_assign_pointer(per_cpu(sd_asym, cpu), sd); | |
518cd623 PZ |
5606 | } |
5607 | ||
1da177e4 | 5608 | /* |
0eab9146 | 5609 | * Attach the domain 'sd' to 'cpu' as its base domain. Callers must |
1da177e4 LT |
5610 | * hold the hotplug lock. |
5611 | */ | |
0eab9146 IM |
5612 | static void |
5613 | cpu_attach_domain(struct sched_domain *sd, struct root_domain *rd, int cpu) | |
1da177e4 | 5614 | { |
70b97a7f | 5615 | struct rq *rq = cpu_rq(cpu); |
245af2c7 SS |
5616 | struct sched_domain *tmp; |
5617 | ||
5618 | /* Remove the sched domains which do not contribute to scheduling. */ | |
f29c9b1c | 5619 | for (tmp = sd; tmp; ) { |
245af2c7 SS |
5620 | struct sched_domain *parent = tmp->parent; |
5621 | if (!parent) | |
5622 | break; | |
f29c9b1c | 5623 | |
1a848870 | 5624 | if (sd_parent_degenerate(tmp, parent)) { |
245af2c7 | 5625 | tmp->parent = parent->parent; |
1a848870 SS |
5626 | if (parent->parent) |
5627 | parent->parent->child = tmp; | |
10866e62 PZ |
5628 | /* |
5629 | * Transfer SD_PREFER_SIBLING down in case of a | |
5630 | * degenerate parent; the spans match for this | |
5631 | * so the property transfers. | |
5632 | */ | |
5633 | if (parent->flags & SD_PREFER_SIBLING) | |
5634 | tmp->flags |= SD_PREFER_SIBLING; | |
dce840a0 | 5635 | destroy_sched_domain(parent, cpu); |
f29c9b1c LZ |
5636 | } else |
5637 | tmp = tmp->parent; | |
245af2c7 SS |
5638 | } |
5639 | ||
1a848870 | 5640 | if (sd && sd_degenerate(sd)) { |
dce840a0 | 5641 | tmp = sd; |
245af2c7 | 5642 | sd = sd->parent; |
dce840a0 | 5643 | destroy_sched_domain(tmp, cpu); |
1a848870 SS |
5644 | if (sd) |
5645 | sd->child = NULL; | |
5646 | } | |
1da177e4 | 5647 | |
4cb98839 | 5648 | sched_domain_debug(sd, cpu); |
1da177e4 | 5649 | |
57d885fe | 5650 | rq_attach_root(rq, rd); |
dce840a0 | 5651 | tmp = rq->sd; |
674311d5 | 5652 | rcu_assign_pointer(rq->sd, sd); |
dce840a0 | 5653 | destroy_sched_domains(tmp, cpu); |
518cd623 PZ |
5654 | |
5655 | update_top_cache_domain(cpu); | |
1da177e4 LT |
5656 | } |
5657 | ||
5658 | /* cpus with isolated domains */ | |
dcc30a35 | 5659 | static cpumask_var_t cpu_isolated_map; |
1da177e4 LT |
5660 | |
5661 | /* Setup the mask of cpus configured for isolated domains */ | |
5662 | static int __init isolated_cpu_setup(char *str) | |
5663 | { | |
bdddd296 | 5664 | alloc_bootmem_cpumask_var(&cpu_isolated_map); |
968ea6d8 | 5665 | cpulist_parse(str, cpu_isolated_map); |
1da177e4 LT |
5666 | return 1; |
5667 | } | |
5668 | ||
8927f494 | 5669 | __setup("isolcpus=", isolated_cpu_setup); |
1da177e4 | 5670 | |
49a02c51 | 5671 | struct s_data { |
21d42ccf | 5672 | struct sched_domain ** __percpu sd; |
49a02c51 AH |
5673 | struct root_domain *rd; |
5674 | }; | |
5675 | ||
2109b99e | 5676 | enum s_alloc { |
2109b99e | 5677 | sa_rootdomain, |
21d42ccf | 5678 | sa_sd, |
dce840a0 | 5679 | sa_sd_storage, |
2109b99e AH |
5680 | sa_none, |
5681 | }; | |
5682 | ||
c1174876 PZ |
5683 | /* |
5684 | * Build an iteration mask that can exclude certain CPUs from the upwards | |
5685 | * domain traversal. | |
5686 | * | |
5687 | * Asymmetric node setups can result in situations where the domain tree is of | |
5688 | * unequal depth, make sure to skip domains that already cover the entire | |
5689 | * range. | |
5690 | * | |
5691 | * In that case build_sched_domains() will have terminated the iteration early | |
5692 | * and our sibling sd spans will be empty. Domains should always include the | |
5693 | * cpu they're built on, so check that. | |
5694 | * | |
5695 | */ | |
5696 | static void build_group_mask(struct sched_domain *sd, struct sched_group *sg) | |
5697 | { | |
5698 | const struct cpumask *span = sched_domain_span(sd); | |
5699 | struct sd_data *sdd = sd->private; | |
5700 | struct sched_domain *sibling; | |
5701 | int i; | |
5702 | ||
5703 | for_each_cpu(i, span) { | |
5704 | sibling = *per_cpu_ptr(sdd->sd, i); | |
5705 | if (!cpumask_test_cpu(i, sched_domain_span(sibling))) | |
5706 | continue; | |
5707 | ||
5708 | cpumask_set_cpu(i, sched_group_mask(sg)); | |
5709 | } | |
5710 | } | |
5711 | ||
5712 | /* | |
5713 | * Return the canonical balance cpu for this group, this is the first cpu | |
5714 | * of this group that's also in the iteration mask. | |
5715 | */ | |
5716 | int group_balance_cpu(struct sched_group *sg) | |
5717 | { | |
5718 | return cpumask_first_and(sched_group_cpus(sg), sched_group_mask(sg)); | |
5719 | } | |
5720 | ||
e3589f6c PZ |
5721 | static int |
5722 | build_overlap_sched_groups(struct sched_domain *sd, int cpu) | |
5723 | { | |
5724 | struct sched_group *first = NULL, *last = NULL, *groups = NULL, *sg; | |
5725 | const struct cpumask *span = sched_domain_span(sd); | |
5726 | struct cpumask *covered = sched_domains_tmpmask; | |
5727 | struct sd_data *sdd = sd->private; | |
5728 | struct sched_domain *child; | |
5729 | int i; | |
5730 | ||
5731 | cpumask_clear(covered); | |
5732 | ||
5733 | for_each_cpu(i, span) { | |
5734 | struct cpumask *sg_span; | |
5735 | ||
5736 | if (cpumask_test_cpu(i, covered)) | |
5737 | continue; | |
5738 | ||
c1174876 PZ |
5739 | child = *per_cpu_ptr(sdd->sd, i); |
5740 | ||
5741 | /* See the comment near build_group_mask(). */ | |
5742 | if (!cpumask_test_cpu(i, sched_domain_span(child))) | |
5743 | continue; | |
5744 | ||
e3589f6c | 5745 | sg = kzalloc_node(sizeof(struct sched_group) + cpumask_size(), |
4d78a223 | 5746 | GFP_KERNEL, cpu_to_node(cpu)); |
e3589f6c PZ |
5747 | |
5748 | if (!sg) | |
5749 | goto fail; | |
5750 | ||
5751 | sg_span = sched_group_cpus(sg); | |
e3589f6c PZ |
5752 | if (child->child) { |
5753 | child = child->child; | |
5754 | cpumask_copy(sg_span, sched_domain_span(child)); | |
5755 | } else | |
5756 | cpumask_set_cpu(i, sg_span); | |
5757 | ||
5758 | cpumask_or(covered, covered, sg_span); | |
5759 | ||
63b2ca30 NP |
5760 | sg->sgc = *per_cpu_ptr(sdd->sgc, i); |
5761 | if (atomic_inc_return(&sg->sgc->ref) == 1) | |
c1174876 PZ |
5762 | build_group_mask(sd, sg); |
5763 | ||
c3decf0d | 5764 | /* |
63b2ca30 | 5765 | * Initialize sgc->capacity such that even if we mess up the |
c3decf0d PZ |
5766 | * domains and no possible iteration will get us here, we won't |
5767 | * die on a /0 trap. | |
5768 | */ | |
ca8ce3d0 | 5769 | sg->sgc->capacity = SCHED_CAPACITY_SCALE * cpumask_weight(sg_span); |
63b2ca30 | 5770 | sg->sgc->capacity_orig = sg->sgc->capacity; |
e3589f6c | 5771 | |
c1174876 PZ |
5772 | /* |
5773 | * Make sure the first group of this domain contains the | |
5774 | * canonical balance cpu. Otherwise the sched_domain iteration | |
5775 | * breaks. See update_sg_lb_stats(). | |
5776 | */ | |
74a5ce20 | 5777 | if ((!groups && cpumask_test_cpu(cpu, sg_span)) || |
c1174876 | 5778 | group_balance_cpu(sg) == cpu) |
e3589f6c PZ |
5779 | groups = sg; |
5780 | ||
5781 | if (!first) | |
5782 | first = sg; | |
5783 | if (last) | |
5784 | last->next = sg; | |
5785 | last = sg; | |
5786 | last->next = first; | |
5787 | } | |
5788 | sd->groups = groups; | |
5789 | ||
5790 | return 0; | |
5791 | ||
5792 | fail: | |
5793 | free_sched_groups(first, 0); | |
5794 | ||
5795 | return -ENOMEM; | |
5796 | } | |
5797 | ||
dce840a0 | 5798 | static int get_group(int cpu, struct sd_data *sdd, struct sched_group **sg) |
1da177e4 | 5799 | { |
dce840a0 PZ |
5800 | struct sched_domain *sd = *per_cpu_ptr(sdd->sd, cpu); |
5801 | struct sched_domain *child = sd->child; | |
1da177e4 | 5802 | |
dce840a0 PZ |
5803 | if (child) |
5804 | cpu = cpumask_first(sched_domain_span(child)); | |
1e9f28fa | 5805 | |
9c3f75cb | 5806 | if (sg) { |
dce840a0 | 5807 | *sg = *per_cpu_ptr(sdd->sg, cpu); |
63b2ca30 NP |
5808 | (*sg)->sgc = *per_cpu_ptr(sdd->sgc, cpu); |
5809 | atomic_set(&(*sg)->sgc->ref, 1); /* for claim_allocations */ | |
9c3f75cb | 5810 | } |
dce840a0 PZ |
5811 | |
5812 | return cpu; | |
1e9f28fa | 5813 | } |
1e9f28fa | 5814 | |
01a08546 | 5815 | /* |
dce840a0 PZ |
5816 | * build_sched_groups will build a circular linked list of the groups |
5817 | * covered by the given span, and will set each group's ->cpumask correctly, | |
ced549fa | 5818 | * and ->cpu_capacity to 0. |
e3589f6c PZ |
5819 | * |
5820 | * Assumes the sched_domain tree is fully constructed | |
01a08546 | 5821 | */ |
e3589f6c PZ |
5822 | static int |
5823 | build_sched_groups(struct sched_domain *sd, int cpu) | |
1da177e4 | 5824 | { |
dce840a0 PZ |
5825 | struct sched_group *first = NULL, *last = NULL; |
5826 | struct sd_data *sdd = sd->private; | |
5827 | const struct cpumask *span = sched_domain_span(sd); | |
f96225fd | 5828 | struct cpumask *covered; |
dce840a0 | 5829 | int i; |
9c1cfda2 | 5830 | |
e3589f6c PZ |
5831 | get_group(cpu, sdd, &sd->groups); |
5832 | atomic_inc(&sd->groups->ref); | |
5833 | ||
0936629f | 5834 | if (cpu != cpumask_first(span)) |
e3589f6c PZ |
5835 | return 0; |
5836 | ||
f96225fd PZ |
5837 | lockdep_assert_held(&sched_domains_mutex); |
5838 | covered = sched_domains_tmpmask; | |
5839 | ||
dce840a0 | 5840 | cpumask_clear(covered); |
6711cab4 | 5841 | |
dce840a0 PZ |
5842 | for_each_cpu(i, span) { |
5843 | struct sched_group *sg; | |
cd08e923 | 5844 | int group, j; |
6711cab4 | 5845 | |
dce840a0 PZ |
5846 | if (cpumask_test_cpu(i, covered)) |
5847 | continue; | |
6711cab4 | 5848 | |
cd08e923 | 5849 | group = get_group(i, sdd, &sg); |
c1174876 | 5850 | cpumask_setall(sched_group_mask(sg)); |
0601a88d | 5851 | |
dce840a0 PZ |
5852 | for_each_cpu(j, span) { |
5853 | if (get_group(j, sdd, NULL) != group) | |
5854 | continue; | |
0601a88d | 5855 | |
dce840a0 PZ |
5856 | cpumask_set_cpu(j, covered); |
5857 | cpumask_set_cpu(j, sched_group_cpus(sg)); | |
5858 | } | |
0601a88d | 5859 | |
dce840a0 PZ |
5860 | if (!first) |
5861 | first = sg; | |
5862 | if (last) | |
5863 | last->next = sg; | |
5864 | last = sg; | |
5865 | } | |
5866 | last->next = first; | |
e3589f6c PZ |
5867 | |
5868 | return 0; | |
0601a88d | 5869 | } |
51888ca2 | 5870 | |
89c4710e | 5871 | /* |
63b2ca30 | 5872 | * Initialize sched groups cpu_capacity. |
89c4710e | 5873 | * |
63b2ca30 | 5874 | * cpu_capacity indicates the capacity of sched group, which is used while |
89c4710e | 5875 | * distributing the load between different sched groups in a sched domain. |
63b2ca30 NP |
5876 | * Typically cpu_capacity for all the groups in a sched domain will be same |
5877 | * unless there are asymmetries in the topology. If there are asymmetries, | |
5878 | * group having more cpu_capacity will pickup more load compared to the | |
5879 | * group having less cpu_capacity. | |
89c4710e | 5880 | */ |
63b2ca30 | 5881 | static void init_sched_groups_capacity(int cpu, struct sched_domain *sd) |
89c4710e | 5882 | { |
e3589f6c | 5883 | struct sched_group *sg = sd->groups; |
89c4710e | 5884 | |
94c95ba6 | 5885 | WARN_ON(!sg); |
e3589f6c PZ |
5886 | |
5887 | do { | |
5888 | sg->group_weight = cpumask_weight(sched_group_cpus(sg)); | |
5889 | sg = sg->next; | |
5890 | } while (sg != sd->groups); | |
89c4710e | 5891 | |
c1174876 | 5892 | if (cpu != group_balance_cpu(sg)) |
e3589f6c | 5893 | return; |
aae6d3dd | 5894 | |
63b2ca30 NP |
5895 | update_group_capacity(sd, cpu); |
5896 | atomic_set(&sg->sgc->nr_busy_cpus, sg->group_weight); | |
89c4710e SS |
5897 | } |
5898 | ||
7c16ec58 MT |
5899 | /* |
5900 | * Initializers for schedule domains | |
5901 | * Non-inlined to reduce accumulated stack pressure in build_sched_domains() | |
5902 | */ | |
5903 | ||
1d3504fc | 5904 | static int default_relax_domain_level = -1; |
60495e77 | 5905 | int sched_domain_level_max; |
1d3504fc HS |
5906 | |
5907 | static int __init setup_relax_domain_level(char *str) | |
5908 | { | |
a841f8ce DS |
5909 | if (kstrtoint(str, 0, &default_relax_domain_level)) |
5910 | pr_warn("Unable to set relax_domain_level\n"); | |
30e0e178 | 5911 | |
1d3504fc HS |
5912 | return 1; |
5913 | } | |
5914 | __setup("relax_domain_level=", setup_relax_domain_level); | |
5915 | ||
5916 | static void set_domain_attribute(struct sched_domain *sd, | |
5917 | struct sched_domain_attr *attr) | |
5918 | { | |
5919 | int request; | |
5920 | ||
5921 | if (!attr || attr->relax_domain_level < 0) { | |
5922 | if (default_relax_domain_level < 0) | |
5923 | return; | |
5924 | else | |
5925 | request = default_relax_domain_level; | |
5926 | } else | |
5927 | request = attr->relax_domain_level; | |
5928 | if (request < sd->level) { | |
5929 | /* turn off idle balance on this domain */ | |
c88d5910 | 5930 | sd->flags &= ~(SD_BALANCE_WAKE|SD_BALANCE_NEWIDLE); |
1d3504fc HS |
5931 | } else { |
5932 | /* turn on idle balance on this domain */ | |
c88d5910 | 5933 | sd->flags |= (SD_BALANCE_WAKE|SD_BALANCE_NEWIDLE); |
1d3504fc HS |
5934 | } |
5935 | } | |
5936 | ||
54ab4ff4 PZ |
5937 | static void __sdt_free(const struct cpumask *cpu_map); |
5938 | static int __sdt_alloc(const struct cpumask *cpu_map); | |
5939 | ||
2109b99e AH |
5940 | static void __free_domain_allocs(struct s_data *d, enum s_alloc what, |
5941 | const struct cpumask *cpu_map) | |
5942 | { | |
5943 | switch (what) { | |
2109b99e | 5944 | case sa_rootdomain: |
822ff793 PZ |
5945 | if (!atomic_read(&d->rd->refcount)) |
5946 | free_rootdomain(&d->rd->rcu); /* fall through */ | |
21d42ccf PZ |
5947 | case sa_sd: |
5948 | free_percpu(d->sd); /* fall through */ | |
dce840a0 | 5949 | case sa_sd_storage: |
54ab4ff4 | 5950 | __sdt_free(cpu_map); /* fall through */ |
2109b99e AH |
5951 | case sa_none: |
5952 | break; | |
5953 | } | |
5954 | } | |
3404c8d9 | 5955 | |
2109b99e AH |
5956 | static enum s_alloc __visit_domain_allocation_hell(struct s_data *d, |
5957 | const struct cpumask *cpu_map) | |
5958 | { | |
dce840a0 PZ |
5959 | memset(d, 0, sizeof(*d)); |
5960 | ||
54ab4ff4 PZ |
5961 | if (__sdt_alloc(cpu_map)) |
5962 | return sa_sd_storage; | |
dce840a0 PZ |
5963 | d->sd = alloc_percpu(struct sched_domain *); |
5964 | if (!d->sd) | |
5965 | return sa_sd_storage; | |
2109b99e | 5966 | d->rd = alloc_rootdomain(); |
dce840a0 | 5967 | if (!d->rd) |
21d42ccf | 5968 | return sa_sd; |
2109b99e AH |
5969 | return sa_rootdomain; |
5970 | } | |
57d885fe | 5971 | |
dce840a0 PZ |
5972 | /* |
5973 | * NULL the sd_data elements we've used to build the sched_domain and | |
5974 | * sched_group structure so that the subsequent __free_domain_allocs() | |
5975 | * will not free the data we're using. | |
5976 | */ | |
5977 | static void claim_allocations(int cpu, struct sched_domain *sd) | |
5978 | { | |
5979 | struct sd_data *sdd = sd->private; | |
dce840a0 PZ |
5980 | |
5981 | WARN_ON_ONCE(*per_cpu_ptr(sdd->sd, cpu) != sd); | |
5982 | *per_cpu_ptr(sdd->sd, cpu) = NULL; | |
5983 | ||
e3589f6c | 5984 | if (atomic_read(&(*per_cpu_ptr(sdd->sg, cpu))->ref)) |
dce840a0 | 5985 | *per_cpu_ptr(sdd->sg, cpu) = NULL; |
e3589f6c | 5986 | |
63b2ca30 NP |
5987 | if (atomic_read(&(*per_cpu_ptr(sdd->sgc, cpu))->ref)) |
5988 | *per_cpu_ptr(sdd->sgc, cpu) = NULL; | |
dce840a0 PZ |
5989 | } |
5990 | ||
cb83b629 | 5991 | #ifdef CONFIG_NUMA |
cb83b629 | 5992 | static int sched_domains_numa_levels; |
cb83b629 PZ |
5993 | static int *sched_domains_numa_distance; |
5994 | static struct cpumask ***sched_domains_numa_masks; | |
5995 | static int sched_domains_curr_level; | |
143e1e28 | 5996 | #endif |
cb83b629 | 5997 | |
143e1e28 VG |
5998 | /* |
5999 | * SD_flags allowed in topology descriptions. | |
6000 | * | |
5d4dfddd | 6001 | * SD_SHARE_CPUCAPACITY - describes SMT topologies |
143e1e28 VG |
6002 | * SD_SHARE_PKG_RESOURCES - describes shared caches |
6003 | * SD_NUMA - describes NUMA topologies | |
d77b3ed5 | 6004 | * SD_SHARE_POWERDOMAIN - describes shared power domain |
143e1e28 VG |
6005 | * |
6006 | * Odd one out: | |
6007 | * SD_ASYM_PACKING - describes SMT quirks | |
6008 | */ | |
6009 | #define TOPOLOGY_SD_FLAGS \ | |
5d4dfddd | 6010 | (SD_SHARE_CPUCAPACITY | \ |
143e1e28 VG |
6011 | SD_SHARE_PKG_RESOURCES | \ |
6012 | SD_NUMA | \ | |
d77b3ed5 VG |
6013 | SD_ASYM_PACKING | \ |
6014 | SD_SHARE_POWERDOMAIN) | |
cb83b629 PZ |
6015 | |
6016 | static struct sched_domain * | |
143e1e28 | 6017 | sd_init(struct sched_domain_topology_level *tl, int cpu) |
cb83b629 PZ |
6018 | { |
6019 | struct sched_domain *sd = *per_cpu_ptr(tl->data.sd, cpu); | |
143e1e28 VG |
6020 | int sd_weight, sd_flags = 0; |
6021 | ||
6022 | #ifdef CONFIG_NUMA | |
6023 | /* | |
6024 | * Ugly hack to pass state to sd_numa_mask()... | |
6025 | */ | |
6026 | sched_domains_curr_level = tl->numa_level; | |
6027 | #endif | |
6028 | ||
6029 | sd_weight = cpumask_weight(tl->mask(cpu)); | |
6030 | ||
6031 | if (tl->sd_flags) | |
6032 | sd_flags = (*tl->sd_flags)(); | |
6033 | if (WARN_ONCE(sd_flags & ~TOPOLOGY_SD_FLAGS, | |
6034 | "wrong sd_flags in topology description\n")) | |
6035 | sd_flags &= ~TOPOLOGY_SD_FLAGS; | |
cb83b629 PZ |
6036 | |
6037 | *sd = (struct sched_domain){ | |
6038 | .min_interval = sd_weight, | |
6039 | .max_interval = 2*sd_weight, | |
6040 | .busy_factor = 32, | |
870a0bb5 | 6041 | .imbalance_pct = 125, |
143e1e28 VG |
6042 | |
6043 | .cache_nice_tries = 0, | |
6044 | .busy_idx = 0, | |
6045 | .idle_idx = 0, | |
cb83b629 PZ |
6046 | .newidle_idx = 0, |
6047 | .wake_idx = 0, | |
6048 | .forkexec_idx = 0, | |
6049 | ||
6050 | .flags = 1*SD_LOAD_BALANCE | |
6051 | | 1*SD_BALANCE_NEWIDLE | |
143e1e28 VG |
6052 | | 1*SD_BALANCE_EXEC |
6053 | | 1*SD_BALANCE_FORK | |
cb83b629 | 6054 | | 0*SD_BALANCE_WAKE |
143e1e28 | 6055 | | 1*SD_WAKE_AFFINE |
5d4dfddd | 6056 | | 0*SD_SHARE_CPUCAPACITY |
cb83b629 | 6057 | | 0*SD_SHARE_PKG_RESOURCES |
143e1e28 | 6058 | | 0*SD_SERIALIZE |
cb83b629 | 6059 | | 0*SD_PREFER_SIBLING |
143e1e28 VG |
6060 | | 0*SD_NUMA |
6061 | | sd_flags | |
cb83b629 | 6062 | , |
143e1e28 | 6063 | |
cb83b629 PZ |
6064 | .last_balance = jiffies, |
6065 | .balance_interval = sd_weight, | |
143e1e28 | 6066 | .smt_gain = 0, |
2b4cfe64 JL |
6067 | .max_newidle_lb_cost = 0, |
6068 | .next_decay_max_lb_cost = jiffies, | |
143e1e28 VG |
6069 | #ifdef CONFIG_SCHED_DEBUG |
6070 | .name = tl->name, | |
6071 | #endif | |
cb83b629 | 6072 | }; |
cb83b629 PZ |
6073 | |
6074 | /* | |
143e1e28 | 6075 | * Convert topological properties into behaviour. |
cb83b629 | 6076 | */ |
143e1e28 | 6077 | |
5d4dfddd | 6078 | if (sd->flags & SD_SHARE_CPUCAPACITY) { |
143e1e28 VG |
6079 | sd->imbalance_pct = 110; |
6080 | sd->smt_gain = 1178; /* ~15% */ | |
143e1e28 VG |
6081 | |
6082 | } else if (sd->flags & SD_SHARE_PKG_RESOURCES) { | |
6083 | sd->imbalance_pct = 117; | |
6084 | sd->cache_nice_tries = 1; | |
6085 | sd->busy_idx = 2; | |
6086 | ||
6087 | #ifdef CONFIG_NUMA | |
6088 | } else if (sd->flags & SD_NUMA) { | |
6089 | sd->cache_nice_tries = 2; | |
6090 | sd->busy_idx = 3; | |
6091 | sd->idle_idx = 2; | |
6092 | ||
6093 | sd->flags |= SD_SERIALIZE; | |
6094 | if (sched_domains_numa_distance[tl->numa_level] > RECLAIM_DISTANCE) { | |
6095 | sd->flags &= ~(SD_BALANCE_EXEC | | |
6096 | SD_BALANCE_FORK | | |
6097 | SD_WAKE_AFFINE); | |
6098 | } | |
6099 | ||
6100 | #endif | |
6101 | } else { | |
6102 | sd->flags |= SD_PREFER_SIBLING; | |
6103 | sd->cache_nice_tries = 1; | |
6104 | sd->busy_idx = 2; | |
6105 | sd->idle_idx = 1; | |
6106 | } | |
6107 | ||
6108 | sd->private = &tl->data; | |
cb83b629 PZ |
6109 | |
6110 | return sd; | |
6111 | } | |
6112 | ||
143e1e28 VG |
6113 | /* |
6114 | * Topology list, bottom-up. | |
6115 | */ | |
6116 | static struct sched_domain_topology_level default_topology[] = { | |
6117 | #ifdef CONFIG_SCHED_SMT | |
6118 | { cpu_smt_mask, cpu_smt_flags, SD_INIT_NAME(SMT) }, | |
6119 | #endif | |
6120 | #ifdef CONFIG_SCHED_MC | |
6121 | { cpu_coregroup_mask, cpu_core_flags, SD_INIT_NAME(MC) }, | |
143e1e28 VG |
6122 | #endif |
6123 | { cpu_cpu_mask, SD_INIT_NAME(DIE) }, | |
6124 | { NULL, }, | |
6125 | }; | |
6126 | ||
6127 | struct sched_domain_topology_level *sched_domain_topology = default_topology; | |
6128 | ||
6129 | #define for_each_sd_topology(tl) \ | |
6130 | for (tl = sched_domain_topology; tl->mask; tl++) | |
6131 | ||
6132 | void set_sched_topology(struct sched_domain_topology_level *tl) | |
6133 | { | |
6134 | sched_domain_topology = tl; | |
6135 | } | |
6136 | ||
6137 | #ifdef CONFIG_NUMA | |
6138 | ||
cb83b629 PZ |
6139 | static const struct cpumask *sd_numa_mask(int cpu) |
6140 | { | |
6141 | return sched_domains_numa_masks[sched_domains_curr_level][cpu_to_node(cpu)]; | |
6142 | } | |
6143 | ||
d039ac60 PZ |
6144 | static void sched_numa_warn(const char *str) |
6145 | { | |
6146 | static int done = false; | |
6147 | int i,j; | |
6148 | ||
6149 | if (done) | |
6150 | return; | |
6151 | ||
6152 | done = true; | |
6153 | ||
6154 | printk(KERN_WARNING "ERROR: %s\n\n", str); | |
6155 | ||
6156 | for (i = 0; i < nr_node_ids; i++) { | |
6157 | printk(KERN_WARNING " "); | |
6158 | for (j = 0; j < nr_node_ids; j++) | |
6159 | printk(KERN_CONT "%02d ", node_distance(i,j)); | |
6160 | printk(KERN_CONT "\n"); | |
6161 | } | |
6162 | printk(KERN_WARNING "\n"); | |
6163 | } | |
6164 | ||
6165 | static bool find_numa_distance(int distance) | |
6166 | { | |
6167 | int i; | |
6168 | ||
6169 | if (distance == node_distance(0, 0)) | |
6170 | return true; | |
6171 | ||
6172 | for (i = 0; i < sched_domains_numa_levels; i++) { | |
6173 | if (sched_domains_numa_distance[i] == distance) | |
6174 | return true; | |
6175 | } | |
6176 | ||
6177 | return false; | |
6178 | } | |
6179 | ||
cb83b629 PZ |
6180 | static void sched_init_numa(void) |
6181 | { | |
6182 | int next_distance, curr_distance = node_distance(0, 0); | |
6183 | struct sched_domain_topology_level *tl; | |
6184 | int level = 0; | |
6185 | int i, j, k; | |
6186 | ||
cb83b629 PZ |
6187 | sched_domains_numa_distance = kzalloc(sizeof(int) * nr_node_ids, GFP_KERNEL); |
6188 | if (!sched_domains_numa_distance) | |
6189 | return; | |
6190 | ||
6191 | /* | |
6192 | * O(nr_nodes^2) deduplicating selection sort -- in order to find the | |
6193 | * unique distances in the node_distance() table. | |
6194 | * | |
6195 | * Assumes node_distance(0,j) includes all distances in | |
6196 | * node_distance(i,j) in order to avoid cubic time. | |
cb83b629 PZ |
6197 | */ |
6198 | next_distance = curr_distance; | |
6199 | for (i = 0; i < nr_node_ids; i++) { | |
6200 | for (j = 0; j < nr_node_ids; j++) { | |
d039ac60 PZ |
6201 | for (k = 0; k < nr_node_ids; k++) { |
6202 | int distance = node_distance(i, k); | |
6203 | ||
6204 | if (distance > curr_distance && | |
6205 | (distance < next_distance || | |
6206 | next_distance == curr_distance)) | |
6207 | next_distance = distance; | |
6208 | ||
6209 | /* | |
6210 | * While not a strong assumption it would be nice to know | |
6211 | * about cases where if node A is connected to B, B is not | |
6212 | * equally connected to A. | |
6213 | */ | |
6214 | if (sched_debug() && node_distance(k, i) != distance) | |
6215 | sched_numa_warn("Node-distance not symmetric"); | |
6216 | ||
6217 | if (sched_debug() && i && !find_numa_distance(distance)) | |
6218 | sched_numa_warn("Node-0 not representative"); | |
6219 | } | |
6220 | if (next_distance != curr_distance) { | |
6221 | sched_domains_numa_distance[level++] = next_distance; | |
6222 | sched_domains_numa_levels = level; | |
6223 | curr_distance = next_distance; | |
6224 | } else break; | |
cb83b629 | 6225 | } |
d039ac60 PZ |
6226 | |
6227 | /* | |
6228 | * In case of sched_debug() we verify the above assumption. | |
6229 | */ | |
6230 | if (!sched_debug()) | |
6231 | break; | |
cb83b629 PZ |
6232 | } |
6233 | /* | |
6234 | * 'level' contains the number of unique distances, excluding the | |
6235 | * identity distance node_distance(i,i). | |
6236 | * | |
28b4a521 | 6237 | * The sched_domains_numa_distance[] array includes the actual distance |
cb83b629 PZ |
6238 | * numbers. |
6239 | */ | |
6240 | ||
5f7865f3 TC |
6241 | /* |
6242 | * Here, we should temporarily reset sched_domains_numa_levels to 0. | |
6243 | * If it fails to allocate memory for array sched_domains_numa_masks[][], | |
6244 | * the array will contain less then 'level' members. This could be | |
6245 | * dangerous when we use it to iterate array sched_domains_numa_masks[][] | |
6246 | * in other functions. | |
6247 | * | |
6248 | * We reset it to 'level' at the end of this function. | |
6249 | */ | |
6250 | sched_domains_numa_levels = 0; | |
6251 | ||
cb83b629 PZ |
6252 | sched_domains_numa_masks = kzalloc(sizeof(void *) * level, GFP_KERNEL); |
6253 | if (!sched_domains_numa_masks) | |
6254 | return; | |
6255 | ||
6256 | /* | |
6257 | * Now for each level, construct a mask per node which contains all | |
6258 | * cpus of nodes that are that many hops away from us. | |
6259 | */ | |
6260 | for (i = 0; i < level; i++) { | |
6261 | sched_domains_numa_masks[i] = | |
6262 | kzalloc(nr_node_ids * sizeof(void *), GFP_KERNEL); | |
6263 | if (!sched_domains_numa_masks[i]) | |
6264 | return; | |
6265 | ||
6266 | for (j = 0; j < nr_node_ids; j++) { | |
2ea45800 | 6267 | struct cpumask *mask = kzalloc(cpumask_size(), GFP_KERNEL); |
cb83b629 PZ |
6268 | if (!mask) |
6269 | return; | |
6270 | ||
6271 | sched_domains_numa_masks[i][j] = mask; | |
6272 | ||
6273 | for (k = 0; k < nr_node_ids; k++) { | |
dd7d8634 | 6274 | if (node_distance(j, k) > sched_domains_numa_distance[i]) |
cb83b629 PZ |
6275 | continue; |
6276 | ||
6277 | cpumask_or(mask, mask, cpumask_of_node(k)); | |
6278 | } | |
6279 | } | |
6280 | } | |
6281 | ||
143e1e28 VG |
6282 | /* Compute default topology size */ |
6283 | for (i = 0; sched_domain_topology[i].mask; i++); | |
6284 | ||
c515db8c | 6285 | tl = kzalloc((i + level + 1) * |
cb83b629 PZ |
6286 | sizeof(struct sched_domain_topology_level), GFP_KERNEL); |
6287 | if (!tl) | |
6288 | return; | |
6289 | ||
6290 | /* | |
6291 | * Copy the default topology bits.. | |
6292 | */ | |
143e1e28 VG |
6293 | for (i = 0; sched_domain_topology[i].mask; i++) |
6294 | tl[i] = sched_domain_topology[i]; | |
cb83b629 PZ |
6295 | |
6296 | /* | |
6297 | * .. and append 'j' levels of NUMA goodness. | |
6298 | */ | |
6299 | for (j = 0; j < level; i++, j++) { | |
6300 | tl[i] = (struct sched_domain_topology_level){ | |
cb83b629 | 6301 | .mask = sd_numa_mask, |
143e1e28 | 6302 | .sd_flags = cpu_numa_flags, |
cb83b629 PZ |
6303 | .flags = SDTL_OVERLAP, |
6304 | .numa_level = j, | |
143e1e28 | 6305 | SD_INIT_NAME(NUMA) |
cb83b629 PZ |
6306 | }; |
6307 | } | |
6308 | ||
6309 | sched_domain_topology = tl; | |
5f7865f3 TC |
6310 | |
6311 | sched_domains_numa_levels = level; | |
cb83b629 | 6312 | } |
301a5cba TC |
6313 | |
6314 | static void sched_domains_numa_masks_set(int cpu) | |
6315 | { | |
6316 | int i, j; | |
6317 | int node = cpu_to_node(cpu); | |
6318 | ||
6319 | for (i = 0; i < sched_domains_numa_levels; i++) { | |
6320 | for (j = 0; j < nr_node_ids; j++) { | |
6321 | if (node_distance(j, node) <= sched_domains_numa_distance[i]) | |
6322 | cpumask_set_cpu(cpu, sched_domains_numa_masks[i][j]); | |
6323 | } | |
6324 | } | |
6325 | } | |
6326 | ||
6327 | static void sched_domains_numa_masks_clear(int cpu) | |
6328 | { | |
6329 | int i, j; | |
6330 | for (i = 0; i < sched_domains_numa_levels; i++) { | |
6331 | for (j = 0; j < nr_node_ids; j++) | |
6332 | cpumask_clear_cpu(cpu, sched_domains_numa_masks[i][j]); | |
6333 | } | |
6334 | } | |
6335 | ||
6336 | /* | |
6337 | * Update sched_domains_numa_masks[level][node] array when new cpus | |
6338 | * are onlined. | |
6339 | */ | |
6340 | static int sched_domains_numa_masks_update(struct notifier_block *nfb, | |
6341 | unsigned long action, | |
6342 | void *hcpu) | |
6343 | { | |
6344 | int cpu = (long)hcpu; | |
6345 | ||
6346 | switch (action & ~CPU_TASKS_FROZEN) { | |
6347 | case CPU_ONLINE: | |
6348 | sched_domains_numa_masks_set(cpu); | |
6349 | break; | |
6350 | ||
6351 | case CPU_DEAD: | |
6352 | sched_domains_numa_masks_clear(cpu); | |
6353 | break; | |
6354 | ||
6355 | default: | |
6356 | return NOTIFY_DONE; | |
6357 | } | |
6358 | ||
6359 | return NOTIFY_OK; | |
cb83b629 PZ |
6360 | } |
6361 | #else | |
6362 | static inline void sched_init_numa(void) | |
6363 | { | |
6364 | } | |
301a5cba TC |
6365 | |
6366 | static int sched_domains_numa_masks_update(struct notifier_block *nfb, | |
6367 | unsigned long action, | |
6368 | void *hcpu) | |
6369 | { | |
6370 | return 0; | |
6371 | } | |
cb83b629 PZ |
6372 | #endif /* CONFIG_NUMA */ |
6373 | ||
54ab4ff4 PZ |
6374 | static int __sdt_alloc(const struct cpumask *cpu_map) |
6375 | { | |
6376 | struct sched_domain_topology_level *tl; | |
6377 | int j; | |
6378 | ||
27723a68 | 6379 | for_each_sd_topology(tl) { |
54ab4ff4 PZ |
6380 | struct sd_data *sdd = &tl->data; |
6381 | ||
6382 | sdd->sd = alloc_percpu(struct sched_domain *); | |
6383 | if (!sdd->sd) | |
6384 | return -ENOMEM; | |
6385 | ||
6386 | sdd->sg = alloc_percpu(struct sched_group *); | |
6387 | if (!sdd->sg) | |
6388 | return -ENOMEM; | |
6389 | ||
63b2ca30 NP |
6390 | sdd->sgc = alloc_percpu(struct sched_group_capacity *); |
6391 | if (!sdd->sgc) | |
9c3f75cb PZ |
6392 | return -ENOMEM; |
6393 | ||
54ab4ff4 PZ |
6394 | for_each_cpu(j, cpu_map) { |
6395 | struct sched_domain *sd; | |
6396 | struct sched_group *sg; | |
63b2ca30 | 6397 | struct sched_group_capacity *sgc; |
54ab4ff4 PZ |
6398 | |
6399 | sd = kzalloc_node(sizeof(struct sched_domain) + cpumask_size(), | |
6400 | GFP_KERNEL, cpu_to_node(j)); | |
6401 | if (!sd) | |
6402 | return -ENOMEM; | |
6403 | ||
6404 | *per_cpu_ptr(sdd->sd, j) = sd; | |
6405 | ||
6406 | sg = kzalloc_node(sizeof(struct sched_group) + cpumask_size(), | |
6407 | GFP_KERNEL, cpu_to_node(j)); | |
6408 | if (!sg) | |
6409 | return -ENOMEM; | |
6410 | ||
30b4e9eb IM |
6411 | sg->next = sg; |
6412 | ||
54ab4ff4 | 6413 | *per_cpu_ptr(sdd->sg, j) = sg; |
9c3f75cb | 6414 | |
63b2ca30 | 6415 | sgc = kzalloc_node(sizeof(struct sched_group_capacity) + cpumask_size(), |
9c3f75cb | 6416 | GFP_KERNEL, cpu_to_node(j)); |
63b2ca30 | 6417 | if (!sgc) |
9c3f75cb PZ |
6418 | return -ENOMEM; |
6419 | ||
63b2ca30 | 6420 | *per_cpu_ptr(sdd->sgc, j) = sgc; |
54ab4ff4 PZ |
6421 | } |
6422 | } | |
6423 | ||
6424 | return 0; | |
6425 | } | |
6426 | ||
6427 | static void __sdt_free(const struct cpumask *cpu_map) | |
6428 | { | |
6429 | struct sched_domain_topology_level *tl; | |
6430 | int j; | |
6431 | ||
27723a68 | 6432 | for_each_sd_topology(tl) { |
54ab4ff4 PZ |
6433 | struct sd_data *sdd = &tl->data; |
6434 | ||
6435 | for_each_cpu(j, cpu_map) { | |
fb2cf2c6 | 6436 | struct sched_domain *sd; |
6437 | ||
6438 | if (sdd->sd) { | |
6439 | sd = *per_cpu_ptr(sdd->sd, j); | |
6440 | if (sd && (sd->flags & SD_OVERLAP)) | |
6441 | free_sched_groups(sd->groups, 0); | |
6442 | kfree(*per_cpu_ptr(sdd->sd, j)); | |
6443 | } | |
6444 | ||
6445 | if (sdd->sg) | |
6446 | kfree(*per_cpu_ptr(sdd->sg, j)); | |
63b2ca30 NP |
6447 | if (sdd->sgc) |
6448 | kfree(*per_cpu_ptr(sdd->sgc, j)); | |
54ab4ff4 PZ |
6449 | } |
6450 | free_percpu(sdd->sd); | |
fb2cf2c6 | 6451 | sdd->sd = NULL; |
54ab4ff4 | 6452 | free_percpu(sdd->sg); |
fb2cf2c6 | 6453 | sdd->sg = NULL; |
63b2ca30 NP |
6454 | free_percpu(sdd->sgc); |
6455 | sdd->sgc = NULL; | |
54ab4ff4 PZ |
6456 | } |
6457 | } | |
6458 | ||
2c402dc3 | 6459 | struct sched_domain *build_sched_domain(struct sched_domain_topology_level *tl, |
4a850cbe VK |
6460 | const struct cpumask *cpu_map, struct sched_domain_attr *attr, |
6461 | struct sched_domain *child, int cpu) | |
2c402dc3 | 6462 | { |
143e1e28 | 6463 | struct sched_domain *sd = sd_init(tl, cpu); |
2c402dc3 | 6464 | if (!sd) |
d069b916 | 6465 | return child; |
2c402dc3 | 6466 | |
2c402dc3 | 6467 | cpumask_and(sched_domain_span(sd), cpu_map, tl->mask(cpu)); |
60495e77 PZ |
6468 | if (child) { |
6469 | sd->level = child->level + 1; | |
6470 | sched_domain_level_max = max(sched_domain_level_max, sd->level); | |
d069b916 | 6471 | child->parent = sd; |
c75e0128 | 6472 | sd->child = child; |
60495e77 | 6473 | } |
a841f8ce | 6474 | set_domain_attribute(sd, attr); |
2c402dc3 PZ |
6475 | |
6476 | return sd; | |
6477 | } | |
6478 | ||
2109b99e AH |
6479 | /* |
6480 | * Build sched domains for a given set of cpus and attach the sched domains | |
6481 | * to the individual cpus | |
6482 | */ | |
dce840a0 PZ |
6483 | static int build_sched_domains(const struct cpumask *cpu_map, |
6484 | struct sched_domain_attr *attr) | |
2109b99e | 6485 | { |
1c632169 | 6486 | enum s_alloc alloc_state; |
dce840a0 | 6487 | struct sched_domain *sd; |
2109b99e | 6488 | struct s_data d; |
822ff793 | 6489 | int i, ret = -ENOMEM; |
9c1cfda2 | 6490 | |
2109b99e AH |
6491 | alloc_state = __visit_domain_allocation_hell(&d, cpu_map); |
6492 | if (alloc_state != sa_rootdomain) | |
6493 | goto error; | |
9c1cfda2 | 6494 | |
dce840a0 | 6495 | /* Set up domains for cpus specified by the cpu_map. */ |
abcd083a | 6496 | for_each_cpu(i, cpu_map) { |
eb7a74e6 PZ |
6497 | struct sched_domain_topology_level *tl; |
6498 | ||
3bd65a80 | 6499 | sd = NULL; |
27723a68 | 6500 | for_each_sd_topology(tl) { |
4a850cbe | 6501 | sd = build_sched_domain(tl, cpu_map, attr, sd, i); |
22da9569 VK |
6502 | if (tl == sched_domain_topology) |
6503 | *per_cpu_ptr(d.sd, i) = sd; | |
e3589f6c PZ |
6504 | if (tl->flags & SDTL_OVERLAP || sched_feat(FORCE_SD_OVERLAP)) |
6505 | sd->flags |= SD_OVERLAP; | |
d110235d PZ |
6506 | if (cpumask_equal(cpu_map, sched_domain_span(sd))) |
6507 | break; | |
e3589f6c | 6508 | } |
dce840a0 PZ |
6509 | } |
6510 | ||
6511 | /* Build the groups for the domains */ | |
6512 | for_each_cpu(i, cpu_map) { | |
6513 | for (sd = *per_cpu_ptr(d.sd, i); sd; sd = sd->parent) { | |
6514 | sd->span_weight = cpumask_weight(sched_domain_span(sd)); | |
e3589f6c PZ |
6515 | if (sd->flags & SD_OVERLAP) { |
6516 | if (build_overlap_sched_groups(sd, i)) | |
6517 | goto error; | |
6518 | } else { | |
6519 | if (build_sched_groups(sd, i)) | |
6520 | goto error; | |
6521 | } | |
1cf51902 | 6522 | } |
a06dadbe | 6523 | } |
9c1cfda2 | 6524 | |
ced549fa | 6525 | /* Calculate CPU capacity for physical packages and nodes */ |
a9c9a9b6 PZ |
6526 | for (i = nr_cpumask_bits-1; i >= 0; i--) { |
6527 | if (!cpumask_test_cpu(i, cpu_map)) | |
6528 | continue; | |
9c1cfda2 | 6529 | |
dce840a0 PZ |
6530 | for (sd = *per_cpu_ptr(d.sd, i); sd; sd = sd->parent) { |
6531 | claim_allocations(i, sd); | |
63b2ca30 | 6532 | init_sched_groups_capacity(i, sd); |
dce840a0 | 6533 | } |
f712c0c7 | 6534 | } |
9c1cfda2 | 6535 | |
1da177e4 | 6536 | /* Attach the domains */ |
dce840a0 | 6537 | rcu_read_lock(); |
abcd083a | 6538 | for_each_cpu(i, cpu_map) { |
21d42ccf | 6539 | sd = *per_cpu_ptr(d.sd, i); |
49a02c51 | 6540 | cpu_attach_domain(sd, d.rd, i); |
1da177e4 | 6541 | } |
dce840a0 | 6542 | rcu_read_unlock(); |
51888ca2 | 6543 | |
822ff793 | 6544 | ret = 0; |
51888ca2 | 6545 | error: |
2109b99e | 6546 | __free_domain_allocs(&d, alloc_state, cpu_map); |
822ff793 | 6547 | return ret; |
1da177e4 | 6548 | } |
029190c5 | 6549 | |
acc3f5d7 | 6550 | static cpumask_var_t *doms_cur; /* current sched domains */ |
029190c5 | 6551 | static int ndoms_cur; /* number of sched domains in 'doms_cur' */ |
4285f594 IM |
6552 | static struct sched_domain_attr *dattr_cur; |
6553 | /* attribues of custom domains in 'doms_cur' */ | |
029190c5 PJ |
6554 | |
6555 | /* | |
6556 | * Special case: If a kmalloc of a doms_cur partition (array of | |
4212823f RR |
6557 | * cpumask) fails, then fallback to a single sched domain, |
6558 | * as determined by the single cpumask fallback_doms. | |
029190c5 | 6559 | */ |
4212823f | 6560 | static cpumask_var_t fallback_doms; |
029190c5 | 6561 | |
ee79d1bd HC |
6562 | /* |
6563 | * arch_update_cpu_topology lets virtualized architectures update the | |
6564 | * cpu core maps. It is supposed to return 1 if the topology changed | |
6565 | * or 0 if it stayed the same. | |
6566 | */ | |
52f5684c | 6567 | int __weak arch_update_cpu_topology(void) |
22e52b07 | 6568 | { |
ee79d1bd | 6569 | return 0; |
22e52b07 HC |
6570 | } |
6571 | ||
acc3f5d7 RR |
6572 | cpumask_var_t *alloc_sched_domains(unsigned int ndoms) |
6573 | { | |
6574 | int i; | |
6575 | cpumask_var_t *doms; | |
6576 | ||
6577 | doms = kmalloc(sizeof(*doms) * ndoms, GFP_KERNEL); | |
6578 | if (!doms) | |
6579 | return NULL; | |
6580 | for (i = 0; i < ndoms; i++) { | |
6581 | if (!alloc_cpumask_var(&doms[i], GFP_KERNEL)) { | |
6582 | free_sched_domains(doms, i); | |
6583 | return NULL; | |
6584 | } | |
6585 | } | |
6586 | return doms; | |
6587 | } | |
6588 | ||
6589 | void free_sched_domains(cpumask_var_t doms[], unsigned int ndoms) | |
6590 | { | |
6591 | unsigned int i; | |
6592 | for (i = 0; i < ndoms; i++) | |
6593 | free_cpumask_var(doms[i]); | |
6594 | kfree(doms); | |
6595 | } | |
6596 | ||
1a20ff27 | 6597 | /* |
41a2d6cf | 6598 | * Set up scheduler domains and groups. Callers must hold the hotplug lock. |
029190c5 PJ |
6599 | * For now this just excludes isolated cpus, but could be used to |
6600 | * exclude other special cases in the future. | |
1a20ff27 | 6601 | */ |
c4a8849a | 6602 | static int init_sched_domains(const struct cpumask *cpu_map) |
1a20ff27 | 6603 | { |
7378547f MM |
6604 | int err; |
6605 | ||
22e52b07 | 6606 | arch_update_cpu_topology(); |
029190c5 | 6607 | ndoms_cur = 1; |
acc3f5d7 | 6608 | doms_cur = alloc_sched_domains(ndoms_cur); |
029190c5 | 6609 | if (!doms_cur) |
acc3f5d7 RR |
6610 | doms_cur = &fallback_doms; |
6611 | cpumask_andnot(doms_cur[0], cpu_map, cpu_isolated_map); | |
dce840a0 | 6612 | err = build_sched_domains(doms_cur[0], NULL); |
6382bc90 | 6613 | register_sched_domain_sysctl(); |
7378547f MM |
6614 | |
6615 | return err; | |
1a20ff27 DG |
6616 | } |
6617 | ||
1a20ff27 DG |
6618 | /* |
6619 | * Detach sched domains from a group of cpus specified in cpu_map | |
6620 | * These cpus will now be attached to the NULL domain | |
6621 | */ | |
96f874e2 | 6622 | static void detach_destroy_domains(const struct cpumask *cpu_map) |
1a20ff27 DG |
6623 | { |
6624 | int i; | |
6625 | ||
dce840a0 | 6626 | rcu_read_lock(); |
abcd083a | 6627 | for_each_cpu(i, cpu_map) |
57d885fe | 6628 | cpu_attach_domain(NULL, &def_root_domain, i); |
dce840a0 | 6629 | rcu_read_unlock(); |
1a20ff27 DG |
6630 | } |
6631 | ||
1d3504fc HS |
6632 | /* handle null as "default" */ |
6633 | static int dattrs_equal(struct sched_domain_attr *cur, int idx_cur, | |
6634 | struct sched_domain_attr *new, int idx_new) | |
6635 | { | |
6636 | struct sched_domain_attr tmp; | |
6637 | ||
6638 | /* fast path */ | |
6639 | if (!new && !cur) | |
6640 | return 1; | |
6641 | ||
6642 | tmp = SD_ATTR_INIT; | |
6643 | return !memcmp(cur ? (cur + idx_cur) : &tmp, | |
6644 | new ? (new + idx_new) : &tmp, | |
6645 | sizeof(struct sched_domain_attr)); | |
6646 | } | |
6647 | ||
029190c5 PJ |
6648 | /* |
6649 | * Partition sched domains as specified by the 'ndoms_new' | |
41a2d6cf | 6650 | * cpumasks in the array doms_new[] of cpumasks. This compares |
029190c5 PJ |
6651 | * doms_new[] to the current sched domain partitioning, doms_cur[]. |
6652 | * It destroys each deleted domain and builds each new domain. | |
6653 | * | |
acc3f5d7 | 6654 | * 'doms_new' is an array of cpumask_var_t's of length 'ndoms_new'. |
41a2d6cf IM |
6655 | * The masks don't intersect (don't overlap.) We should setup one |
6656 | * sched domain for each mask. CPUs not in any of the cpumasks will | |
6657 | * not be load balanced. If the same cpumask appears both in the | |
029190c5 PJ |
6658 | * current 'doms_cur' domains and in the new 'doms_new', we can leave |
6659 | * it as it is. | |
6660 | * | |
acc3f5d7 RR |
6661 | * The passed in 'doms_new' should be allocated using |
6662 | * alloc_sched_domains. This routine takes ownership of it and will | |
6663 | * free_sched_domains it when done with it. If the caller failed the | |
6664 | * alloc call, then it can pass in doms_new == NULL && ndoms_new == 1, | |
6665 | * and partition_sched_domains() will fallback to the single partition | |
6666 | * 'fallback_doms', it also forces the domains to be rebuilt. | |
029190c5 | 6667 | * |
96f874e2 | 6668 | * If doms_new == NULL it will be replaced with cpu_online_mask. |
700018e0 LZ |
6669 | * ndoms_new == 0 is a special case for destroying existing domains, |
6670 | * and it will not create the default domain. | |
dfb512ec | 6671 | * |
029190c5 PJ |
6672 | * Call with hotplug lock held |
6673 | */ | |
acc3f5d7 | 6674 | void partition_sched_domains(int ndoms_new, cpumask_var_t doms_new[], |
1d3504fc | 6675 | struct sched_domain_attr *dattr_new) |
029190c5 | 6676 | { |
dfb512ec | 6677 | int i, j, n; |
d65bd5ec | 6678 | int new_topology; |
029190c5 | 6679 | |
712555ee | 6680 | mutex_lock(&sched_domains_mutex); |
a1835615 | 6681 | |
7378547f MM |
6682 | /* always unregister in case we don't destroy any domains */ |
6683 | unregister_sched_domain_sysctl(); | |
6684 | ||
d65bd5ec HC |
6685 | /* Let architecture update cpu core mappings. */ |
6686 | new_topology = arch_update_cpu_topology(); | |
6687 | ||
dfb512ec | 6688 | n = doms_new ? ndoms_new : 0; |
029190c5 PJ |
6689 | |
6690 | /* Destroy deleted domains */ | |
6691 | for (i = 0; i < ndoms_cur; i++) { | |
d65bd5ec | 6692 | for (j = 0; j < n && !new_topology; j++) { |
acc3f5d7 | 6693 | if (cpumask_equal(doms_cur[i], doms_new[j]) |
1d3504fc | 6694 | && dattrs_equal(dattr_cur, i, dattr_new, j)) |
029190c5 PJ |
6695 | goto match1; |
6696 | } | |
6697 | /* no match - a current sched domain not in new doms_new[] */ | |
acc3f5d7 | 6698 | detach_destroy_domains(doms_cur[i]); |
029190c5 PJ |
6699 | match1: |
6700 | ; | |
6701 | } | |
6702 | ||
c8d2d47a | 6703 | n = ndoms_cur; |
e761b772 | 6704 | if (doms_new == NULL) { |
c8d2d47a | 6705 | n = 0; |
acc3f5d7 | 6706 | doms_new = &fallback_doms; |
6ad4c188 | 6707 | cpumask_andnot(doms_new[0], cpu_active_mask, cpu_isolated_map); |
faa2f98f | 6708 | WARN_ON_ONCE(dattr_new); |
e761b772 MK |
6709 | } |
6710 | ||
029190c5 PJ |
6711 | /* Build new domains */ |
6712 | for (i = 0; i < ndoms_new; i++) { | |
c8d2d47a | 6713 | for (j = 0; j < n && !new_topology; j++) { |
acc3f5d7 | 6714 | if (cpumask_equal(doms_new[i], doms_cur[j]) |
1d3504fc | 6715 | && dattrs_equal(dattr_new, i, dattr_cur, j)) |
029190c5 PJ |
6716 | goto match2; |
6717 | } | |
6718 | /* no match - add a new doms_new */ | |
dce840a0 | 6719 | build_sched_domains(doms_new[i], dattr_new ? dattr_new + i : NULL); |
029190c5 PJ |
6720 | match2: |
6721 | ; | |
6722 | } | |
6723 | ||
6724 | /* Remember the new sched domains */ | |
acc3f5d7 RR |
6725 | if (doms_cur != &fallback_doms) |
6726 | free_sched_domains(doms_cur, ndoms_cur); | |
1d3504fc | 6727 | kfree(dattr_cur); /* kfree(NULL) is safe */ |
029190c5 | 6728 | doms_cur = doms_new; |
1d3504fc | 6729 | dattr_cur = dattr_new; |
029190c5 | 6730 | ndoms_cur = ndoms_new; |
7378547f MM |
6731 | |
6732 | register_sched_domain_sysctl(); | |
a1835615 | 6733 | |
712555ee | 6734 | mutex_unlock(&sched_domains_mutex); |
029190c5 PJ |
6735 | } |
6736 | ||
d35be8ba SB |
6737 | static int num_cpus_frozen; /* used to mark begin/end of suspend/resume */ |
6738 | ||
1da177e4 | 6739 | /* |
3a101d05 TH |
6740 | * Update cpusets according to cpu_active mask. If cpusets are |
6741 | * disabled, cpuset_update_active_cpus() becomes a simple wrapper | |
6742 | * around partition_sched_domains(). | |
d35be8ba SB |
6743 | * |
6744 | * If we come here as part of a suspend/resume, don't touch cpusets because we | |
6745 | * want to restore it back to its original state upon resume anyway. | |
1da177e4 | 6746 | */ |
0b2e918a TH |
6747 | static int cpuset_cpu_active(struct notifier_block *nfb, unsigned long action, |
6748 | void *hcpu) | |
e761b772 | 6749 | { |
d35be8ba SB |
6750 | switch (action) { |
6751 | case CPU_ONLINE_FROZEN: | |
6752 | case CPU_DOWN_FAILED_FROZEN: | |
6753 | ||
6754 | /* | |
6755 | * num_cpus_frozen tracks how many CPUs are involved in suspend | |
6756 | * resume sequence. As long as this is not the last online | |
6757 | * operation in the resume sequence, just build a single sched | |
6758 | * domain, ignoring cpusets. | |
6759 | */ | |
6760 | num_cpus_frozen--; | |
6761 | if (likely(num_cpus_frozen)) { | |
6762 | partition_sched_domains(1, NULL, NULL); | |
6763 | break; | |
6764 | } | |
6765 | ||
6766 | /* | |
6767 | * This is the last CPU online operation. So fall through and | |
6768 | * restore the original sched domains by considering the | |
6769 | * cpuset configurations. | |
6770 | */ | |
6771 | ||
e761b772 | 6772 | case CPU_ONLINE: |
6ad4c188 | 6773 | case CPU_DOWN_FAILED: |
7ddf96b0 | 6774 | cpuset_update_active_cpus(true); |
d35be8ba | 6775 | break; |
3a101d05 TH |
6776 | default: |
6777 | return NOTIFY_DONE; | |
6778 | } | |
d35be8ba | 6779 | return NOTIFY_OK; |
3a101d05 | 6780 | } |
e761b772 | 6781 | |
0b2e918a TH |
6782 | static int cpuset_cpu_inactive(struct notifier_block *nfb, unsigned long action, |
6783 | void *hcpu) | |
3a101d05 | 6784 | { |
d35be8ba | 6785 | switch (action) { |
3a101d05 | 6786 | case CPU_DOWN_PREPARE: |
7ddf96b0 | 6787 | cpuset_update_active_cpus(false); |
d35be8ba SB |
6788 | break; |
6789 | case CPU_DOWN_PREPARE_FROZEN: | |
6790 | num_cpus_frozen++; | |
6791 | partition_sched_domains(1, NULL, NULL); | |
6792 | break; | |
e761b772 MK |
6793 | default: |
6794 | return NOTIFY_DONE; | |
6795 | } | |
d35be8ba | 6796 | return NOTIFY_OK; |
e761b772 | 6797 | } |
e761b772 | 6798 | |
1da177e4 LT |
6799 | void __init sched_init_smp(void) |
6800 | { | |
dcc30a35 RR |
6801 | cpumask_var_t non_isolated_cpus; |
6802 | ||
6803 | alloc_cpumask_var(&non_isolated_cpus, GFP_KERNEL); | |
cb5fd13f | 6804 | alloc_cpumask_var(&fallback_doms, GFP_KERNEL); |
5c1e1767 | 6805 | |
cb83b629 PZ |
6806 | sched_init_numa(); |
6807 | ||
6acce3ef PZ |
6808 | /* |
6809 | * There's no userspace yet to cause hotplug operations; hence all the | |
6810 | * cpu masks are stable and all blatant races in the below code cannot | |
6811 | * happen. | |
6812 | */ | |
712555ee | 6813 | mutex_lock(&sched_domains_mutex); |
c4a8849a | 6814 | init_sched_domains(cpu_active_mask); |
dcc30a35 RR |
6815 | cpumask_andnot(non_isolated_cpus, cpu_possible_mask, cpu_isolated_map); |
6816 | if (cpumask_empty(non_isolated_cpus)) | |
6817 | cpumask_set_cpu(smp_processor_id(), non_isolated_cpus); | |
712555ee | 6818 | mutex_unlock(&sched_domains_mutex); |
e761b772 | 6819 | |
301a5cba | 6820 | hotcpu_notifier(sched_domains_numa_masks_update, CPU_PRI_SCHED_ACTIVE); |
3a101d05 TH |
6821 | hotcpu_notifier(cpuset_cpu_active, CPU_PRI_CPUSET_ACTIVE); |
6822 | hotcpu_notifier(cpuset_cpu_inactive, CPU_PRI_CPUSET_INACTIVE); | |
e761b772 | 6823 | |
b328ca18 | 6824 | init_hrtick(); |
5c1e1767 NP |
6825 | |
6826 | /* Move init over to a non-isolated CPU */ | |
dcc30a35 | 6827 | if (set_cpus_allowed_ptr(current, non_isolated_cpus) < 0) |
5c1e1767 | 6828 | BUG(); |
19978ca6 | 6829 | sched_init_granularity(); |
dcc30a35 | 6830 | free_cpumask_var(non_isolated_cpus); |
4212823f | 6831 | |
0e3900e6 | 6832 | init_sched_rt_class(); |
1baca4ce | 6833 | init_sched_dl_class(); |
1da177e4 LT |
6834 | } |
6835 | #else | |
6836 | void __init sched_init_smp(void) | |
6837 | { | |
19978ca6 | 6838 | sched_init_granularity(); |
1da177e4 LT |
6839 | } |
6840 | #endif /* CONFIG_SMP */ | |
6841 | ||
cd1bb94b AB |
6842 | const_debug unsigned int sysctl_timer_migration = 1; |
6843 | ||
1da177e4 LT |
6844 | int in_sched_functions(unsigned long addr) |
6845 | { | |
1da177e4 LT |
6846 | return in_lock_functions(addr) || |
6847 | (addr >= (unsigned long)__sched_text_start | |
6848 | && addr < (unsigned long)__sched_text_end); | |
6849 | } | |
6850 | ||
029632fb | 6851 | #ifdef CONFIG_CGROUP_SCHED |
27b4b931 LZ |
6852 | /* |
6853 | * Default task group. | |
6854 | * Every task in system belongs to this group at bootup. | |
6855 | */ | |
029632fb | 6856 | struct task_group root_task_group; |
35cf4e50 | 6857 | LIST_HEAD(task_groups); |
052f1dc7 | 6858 | #endif |
6f505b16 | 6859 | |
e6252c3e | 6860 | DECLARE_PER_CPU(cpumask_var_t, load_balance_mask); |
6f505b16 | 6861 | |
1da177e4 LT |
6862 | void __init sched_init(void) |
6863 | { | |
dd41f596 | 6864 | int i, j; |
434d53b0 MT |
6865 | unsigned long alloc_size = 0, ptr; |
6866 | ||
6867 | #ifdef CONFIG_FAIR_GROUP_SCHED | |
6868 | alloc_size += 2 * nr_cpu_ids * sizeof(void **); | |
6869 | #endif | |
6870 | #ifdef CONFIG_RT_GROUP_SCHED | |
6871 | alloc_size += 2 * nr_cpu_ids * sizeof(void **); | |
eff766a6 | 6872 | #endif |
df7c8e84 | 6873 | #ifdef CONFIG_CPUMASK_OFFSTACK |
8c083f08 | 6874 | alloc_size += num_possible_cpus() * cpumask_size(); |
434d53b0 | 6875 | #endif |
434d53b0 | 6876 | if (alloc_size) { |
36b7b6d4 | 6877 | ptr = (unsigned long)kzalloc(alloc_size, GFP_NOWAIT); |
434d53b0 MT |
6878 | |
6879 | #ifdef CONFIG_FAIR_GROUP_SCHED | |
07e06b01 | 6880 | root_task_group.se = (struct sched_entity **)ptr; |
434d53b0 MT |
6881 | ptr += nr_cpu_ids * sizeof(void **); |
6882 | ||
07e06b01 | 6883 | root_task_group.cfs_rq = (struct cfs_rq **)ptr; |
434d53b0 | 6884 | ptr += nr_cpu_ids * sizeof(void **); |
eff766a6 | 6885 | |
6d6bc0ad | 6886 | #endif /* CONFIG_FAIR_GROUP_SCHED */ |
434d53b0 | 6887 | #ifdef CONFIG_RT_GROUP_SCHED |
07e06b01 | 6888 | root_task_group.rt_se = (struct sched_rt_entity **)ptr; |
434d53b0 MT |
6889 | ptr += nr_cpu_ids * sizeof(void **); |
6890 | ||
07e06b01 | 6891 | root_task_group.rt_rq = (struct rt_rq **)ptr; |
eff766a6 PZ |
6892 | ptr += nr_cpu_ids * sizeof(void **); |
6893 | ||
6d6bc0ad | 6894 | #endif /* CONFIG_RT_GROUP_SCHED */ |
df7c8e84 RR |
6895 | #ifdef CONFIG_CPUMASK_OFFSTACK |
6896 | for_each_possible_cpu(i) { | |
e6252c3e | 6897 | per_cpu(load_balance_mask, i) = (void *)ptr; |
df7c8e84 RR |
6898 | ptr += cpumask_size(); |
6899 | } | |
6900 | #endif /* CONFIG_CPUMASK_OFFSTACK */ | |
434d53b0 | 6901 | } |
dd41f596 | 6902 | |
332ac17e DF |
6903 | init_rt_bandwidth(&def_rt_bandwidth, |
6904 | global_rt_period(), global_rt_runtime()); | |
6905 | init_dl_bandwidth(&def_dl_bandwidth, | |
1724813d | 6906 | global_rt_period(), global_rt_runtime()); |
332ac17e | 6907 | |
57d885fe GH |
6908 | #ifdef CONFIG_SMP |
6909 | init_defrootdomain(); | |
6910 | #endif | |
6911 | ||
d0b27fa7 | 6912 | #ifdef CONFIG_RT_GROUP_SCHED |
07e06b01 | 6913 | init_rt_bandwidth(&root_task_group.rt_bandwidth, |
d0b27fa7 | 6914 | global_rt_period(), global_rt_runtime()); |
6d6bc0ad | 6915 | #endif /* CONFIG_RT_GROUP_SCHED */ |
d0b27fa7 | 6916 | |
7c941438 | 6917 | #ifdef CONFIG_CGROUP_SCHED |
07e06b01 YZ |
6918 | list_add(&root_task_group.list, &task_groups); |
6919 | INIT_LIST_HEAD(&root_task_group.children); | |
f4d6f6c2 | 6920 | INIT_LIST_HEAD(&root_task_group.siblings); |
5091faa4 | 6921 | autogroup_init(&init_task); |
54c707e9 | 6922 | |
7c941438 | 6923 | #endif /* CONFIG_CGROUP_SCHED */ |
6f505b16 | 6924 | |
0a945022 | 6925 | for_each_possible_cpu(i) { |
70b97a7f | 6926 | struct rq *rq; |
1da177e4 LT |
6927 | |
6928 | rq = cpu_rq(i); | |
05fa785c | 6929 | raw_spin_lock_init(&rq->lock); |
7897986b | 6930 | rq->nr_running = 0; |
dce48a84 TG |
6931 | rq->calc_load_active = 0; |
6932 | rq->calc_load_update = jiffies + LOAD_FREQ; | |
acb5a9ba | 6933 | init_cfs_rq(&rq->cfs); |
6f505b16 | 6934 | init_rt_rq(&rq->rt, rq); |
aab03e05 | 6935 | init_dl_rq(&rq->dl, rq); |
dd41f596 | 6936 | #ifdef CONFIG_FAIR_GROUP_SCHED |
029632fb | 6937 | root_task_group.shares = ROOT_TASK_GROUP_LOAD; |
6f505b16 | 6938 | INIT_LIST_HEAD(&rq->leaf_cfs_rq_list); |
354d60c2 | 6939 | /* |
07e06b01 | 6940 | * How much cpu bandwidth does root_task_group get? |
354d60c2 DG |
6941 | * |
6942 | * In case of task-groups formed thr' the cgroup filesystem, it | |
6943 | * gets 100% of the cpu resources in the system. This overall | |
6944 | * system cpu resource is divided among the tasks of | |
07e06b01 | 6945 | * root_task_group and its child task-groups in a fair manner, |
354d60c2 DG |
6946 | * based on each entity's (task or task-group's) weight |
6947 | * (se->load.weight). | |
6948 | * | |
07e06b01 | 6949 | * In other words, if root_task_group has 10 tasks of weight |
354d60c2 DG |
6950 | * 1024) and two child groups A0 and A1 (of weight 1024 each), |
6951 | * then A0's share of the cpu resource is: | |
6952 | * | |
0d905bca | 6953 | * A0's bandwidth = 1024 / (10*1024 + 1024 + 1024) = 8.33% |
354d60c2 | 6954 | * |
07e06b01 YZ |
6955 | * We achieve this by letting root_task_group's tasks sit |
6956 | * directly in rq->cfs (i.e root_task_group->se[] = NULL). | |
354d60c2 | 6957 | */ |
ab84d31e | 6958 | init_cfs_bandwidth(&root_task_group.cfs_bandwidth); |
07e06b01 | 6959 | init_tg_cfs_entry(&root_task_group, &rq->cfs, NULL, i, NULL); |
354d60c2 DG |
6960 | #endif /* CONFIG_FAIR_GROUP_SCHED */ |
6961 | ||
6962 | rq->rt.rt_runtime = def_rt_bandwidth.rt_runtime; | |
052f1dc7 | 6963 | #ifdef CONFIG_RT_GROUP_SCHED |
07e06b01 | 6964 | init_tg_rt_entry(&root_task_group, &rq->rt, NULL, i, NULL); |
dd41f596 | 6965 | #endif |
1da177e4 | 6966 | |
dd41f596 IM |
6967 | for (j = 0; j < CPU_LOAD_IDX_MAX; j++) |
6968 | rq->cpu_load[j] = 0; | |
fdf3e95d VP |
6969 | |
6970 | rq->last_load_update_tick = jiffies; | |
6971 | ||
1da177e4 | 6972 | #ifdef CONFIG_SMP |
41c7ce9a | 6973 | rq->sd = NULL; |
57d885fe | 6974 | rq->rd = NULL; |
ca8ce3d0 | 6975 | rq->cpu_capacity = SCHED_CAPACITY_SCALE; |
3f029d3c | 6976 | rq->post_schedule = 0; |
1da177e4 | 6977 | rq->active_balance = 0; |
dd41f596 | 6978 | rq->next_balance = jiffies; |
1da177e4 | 6979 | rq->push_cpu = 0; |
0a2966b4 | 6980 | rq->cpu = i; |
1f11eb6a | 6981 | rq->online = 0; |
eae0c9df MG |
6982 | rq->idle_stamp = 0; |
6983 | rq->avg_idle = 2*sysctl_sched_migration_cost; | |
9bd721c5 | 6984 | rq->max_idle_balance_cost = sysctl_sched_migration_cost; |
367456c7 PZ |
6985 | |
6986 | INIT_LIST_HEAD(&rq->cfs_tasks); | |
6987 | ||
dc938520 | 6988 | rq_attach_root(rq, &def_root_domain); |
3451d024 | 6989 | #ifdef CONFIG_NO_HZ_COMMON |
1c792db7 | 6990 | rq->nohz_flags = 0; |
83cd4fe2 | 6991 | #endif |
265f22a9 FW |
6992 | #ifdef CONFIG_NO_HZ_FULL |
6993 | rq->last_sched_tick = 0; | |
6994 | #endif | |
1da177e4 | 6995 | #endif |
8f4d37ec | 6996 | init_rq_hrtick(rq); |
1da177e4 | 6997 | atomic_set(&rq->nr_iowait, 0); |
1da177e4 LT |
6998 | } |
6999 | ||
2dd73a4f | 7000 | set_load_weight(&init_task); |
b50f60ce | 7001 | |
e107be36 AK |
7002 | #ifdef CONFIG_PREEMPT_NOTIFIERS |
7003 | INIT_HLIST_HEAD(&init_task.preempt_notifiers); | |
7004 | #endif | |
7005 | ||
1da177e4 LT |
7006 | /* |
7007 | * The boot idle thread does lazy MMU switching as well: | |
7008 | */ | |
7009 | atomic_inc(&init_mm.mm_count); | |
7010 | enter_lazy_tlb(&init_mm, current); | |
7011 | ||
7012 | /* | |
7013 | * Make us the idle thread. Technically, schedule() should not be | |
7014 | * called from this thread, however somewhere below it might be, | |
7015 | * but because we are the idle thread, we just pick up running again | |
7016 | * when this runqueue becomes "idle". | |
7017 | */ | |
7018 | init_idle(current, smp_processor_id()); | |
dce48a84 TG |
7019 | |
7020 | calc_load_update = jiffies + LOAD_FREQ; | |
7021 | ||
dd41f596 IM |
7022 | /* |
7023 | * During early bootup we pretend to be a normal task: | |
7024 | */ | |
7025 | current->sched_class = &fair_sched_class; | |
6892b75e | 7026 | |
bf4d83f6 | 7027 | #ifdef CONFIG_SMP |
4cb98839 | 7028 | zalloc_cpumask_var(&sched_domains_tmpmask, GFP_NOWAIT); |
bdddd296 RR |
7029 | /* May be allocated at isolcpus cmdline parse time */ |
7030 | if (cpu_isolated_map == NULL) | |
7031 | zalloc_cpumask_var(&cpu_isolated_map, GFP_NOWAIT); | |
29d5e047 | 7032 | idle_thread_set_boot_cpu(); |
a803f026 | 7033 | set_cpu_rq_start_time(); |
029632fb PZ |
7034 | #endif |
7035 | init_sched_fair_class(); | |
6a7b3dc3 | 7036 | |
6892b75e | 7037 | scheduler_running = 1; |
1da177e4 LT |
7038 | } |
7039 | ||
d902db1e | 7040 | #ifdef CONFIG_DEBUG_ATOMIC_SLEEP |
e4aafea2 FW |
7041 | static inline int preempt_count_equals(int preempt_offset) |
7042 | { | |
234da7bc | 7043 | int nested = (preempt_count() & ~PREEMPT_ACTIVE) + rcu_preempt_depth(); |
e4aafea2 | 7044 | |
4ba8216c | 7045 | return (nested == preempt_offset); |
e4aafea2 FW |
7046 | } |
7047 | ||
d894837f | 7048 | void __might_sleep(const char *file, int line, int preempt_offset) |
1da177e4 | 7049 | { |
1da177e4 LT |
7050 | static unsigned long prev_jiffy; /* ratelimiting */ |
7051 | ||
b3fbab05 | 7052 | rcu_sleep_check(); /* WARN_ON_ONCE() by default, no rate limit reqd. */ |
db273be2 TG |
7053 | if ((preempt_count_equals(preempt_offset) && !irqs_disabled() && |
7054 | !is_idle_task(current)) || | |
e4aafea2 | 7055 | system_state != SYSTEM_RUNNING || oops_in_progress) |
aef745fc IM |
7056 | return; |
7057 | if (time_before(jiffies, prev_jiffy + HZ) && prev_jiffy) | |
7058 | return; | |
7059 | prev_jiffy = jiffies; | |
7060 | ||
3df0fc5b PZ |
7061 | printk(KERN_ERR |
7062 | "BUG: sleeping function called from invalid context at %s:%d\n", | |
7063 | file, line); | |
7064 | printk(KERN_ERR | |
7065 | "in_atomic(): %d, irqs_disabled(): %d, pid: %d, name: %s\n", | |
7066 | in_atomic(), irqs_disabled(), | |
7067 | current->pid, current->comm); | |
aef745fc IM |
7068 | |
7069 | debug_show_held_locks(current); | |
7070 | if (irqs_disabled()) | |
7071 | print_irqtrace_events(current); | |
8f47b187 TG |
7072 | #ifdef CONFIG_DEBUG_PREEMPT |
7073 | if (!preempt_count_equals(preempt_offset)) { | |
7074 | pr_err("Preemption disabled at:"); | |
7075 | print_ip_sym(current->preempt_disable_ip); | |
7076 | pr_cont("\n"); | |
7077 | } | |
7078 | #endif | |
aef745fc | 7079 | dump_stack(); |
1da177e4 LT |
7080 | } |
7081 | EXPORT_SYMBOL(__might_sleep); | |
7082 | #endif | |
7083 | ||
7084 | #ifdef CONFIG_MAGIC_SYSRQ | |
3a5e4dc1 AK |
7085 | static void normalize_task(struct rq *rq, struct task_struct *p) |
7086 | { | |
da7a735e | 7087 | const struct sched_class *prev_class = p->sched_class; |
d50dde5a DF |
7088 | struct sched_attr attr = { |
7089 | .sched_policy = SCHED_NORMAL, | |
7090 | }; | |
da7a735e | 7091 | int old_prio = p->prio; |
3a5e4dc1 | 7092 | int on_rq; |
3e51f33f | 7093 | |
fd2f4419 | 7094 | on_rq = p->on_rq; |
3a5e4dc1 | 7095 | if (on_rq) |
4ca9b72b | 7096 | dequeue_task(rq, p, 0); |
d50dde5a | 7097 | __setscheduler(rq, p, &attr); |
3a5e4dc1 | 7098 | if (on_rq) { |
4ca9b72b | 7099 | enqueue_task(rq, p, 0); |
3a5e4dc1 AK |
7100 | resched_task(rq->curr); |
7101 | } | |
da7a735e PZ |
7102 | |
7103 | check_class_changed(rq, p, prev_class, old_prio); | |
3a5e4dc1 AK |
7104 | } |
7105 | ||
1da177e4 LT |
7106 | void normalize_rt_tasks(void) |
7107 | { | |
a0f98a1c | 7108 | struct task_struct *g, *p; |
1da177e4 | 7109 | unsigned long flags; |
70b97a7f | 7110 | struct rq *rq; |
1da177e4 | 7111 | |
4cf5d77a | 7112 | read_lock_irqsave(&tasklist_lock, flags); |
a0f98a1c | 7113 | do_each_thread(g, p) { |
178be793 IM |
7114 | /* |
7115 | * Only normalize user tasks: | |
7116 | */ | |
7117 | if (!p->mm) | |
7118 | continue; | |
7119 | ||
6cfb0d5d | 7120 | p->se.exec_start = 0; |
6cfb0d5d | 7121 | #ifdef CONFIG_SCHEDSTATS |
41acab88 LDM |
7122 | p->se.statistics.wait_start = 0; |
7123 | p->se.statistics.sleep_start = 0; | |
7124 | p->se.statistics.block_start = 0; | |
6cfb0d5d | 7125 | #endif |
dd41f596 | 7126 | |
aab03e05 | 7127 | if (!dl_task(p) && !rt_task(p)) { |
dd41f596 IM |
7128 | /* |
7129 | * Renice negative nice level userspace | |
7130 | * tasks back to 0: | |
7131 | */ | |
d0ea0268 | 7132 | if (task_nice(p) < 0 && p->mm) |
dd41f596 | 7133 | set_user_nice(p, 0); |
1da177e4 | 7134 | continue; |
dd41f596 | 7135 | } |
1da177e4 | 7136 | |
1d615482 | 7137 | raw_spin_lock(&p->pi_lock); |
b29739f9 | 7138 | rq = __task_rq_lock(p); |
1da177e4 | 7139 | |
178be793 | 7140 | normalize_task(rq, p); |
3a5e4dc1 | 7141 | |
b29739f9 | 7142 | __task_rq_unlock(rq); |
1d615482 | 7143 | raw_spin_unlock(&p->pi_lock); |
a0f98a1c IM |
7144 | } while_each_thread(g, p); |
7145 | ||
4cf5d77a | 7146 | read_unlock_irqrestore(&tasklist_lock, flags); |
1da177e4 LT |
7147 | } |
7148 | ||
7149 | #endif /* CONFIG_MAGIC_SYSRQ */ | |
1df5c10a | 7150 | |
67fc4e0c | 7151 | #if defined(CONFIG_IA64) || defined(CONFIG_KGDB_KDB) |
1df5c10a | 7152 | /* |
67fc4e0c | 7153 | * These functions are only useful for the IA64 MCA handling, or kdb. |
1df5c10a LT |
7154 | * |
7155 | * They can only be called when the whole system has been | |
7156 | * stopped - every CPU needs to be quiescent, and no scheduling | |
7157 | * activity can take place. Using them for anything else would | |
7158 | * be a serious bug, and as a result, they aren't even visible | |
7159 | * under any other configuration. | |
7160 | */ | |
7161 | ||
7162 | /** | |
7163 | * curr_task - return the current task for a given cpu. | |
7164 | * @cpu: the processor in question. | |
7165 | * | |
7166 | * ONLY VALID WHEN THE WHOLE SYSTEM IS STOPPED! | |
e69f6186 YB |
7167 | * |
7168 | * Return: The current task for @cpu. | |
1df5c10a | 7169 | */ |
36c8b586 | 7170 | struct task_struct *curr_task(int cpu) |
1df5c10a LT |
7171 | { |
7172 | return cpu_curr(cpu); | |
7173 | } | |
7174 | ||
67fc4e0c JW |
7175 | #endif /* defined(CONFIG_IA64) || defined(CONFIG_KGDB_KDB) */ |
7176 | ||
7177 | #ifdef CONFIG_IA64 | |
1df5c10a LT |
7178 | /** |
7179 | * set_curr_task - set the current task for a given cpu. | |
7180 | * @cpu: the processor in question. | |
7181 | * @p: the task pointer to set. | |
7182 | * | |
7183 | * Description: This function must only be used when non-maskable interrupts | |
41a2d6cf IM |
7184 | * are serviced on a separate stack. It allows the architecture to switch the |
7185 | * notion of the current task on a cpu in a non-blocking manner. This function | |
1df5c10a LT |
7186 | * must be called with all CPU's synchronized, and interrupts disabled, the |
7187 | * and caller must save the original value of the current task (see | |
7188 | * curr_task() above) and restore that value before reenabling interrupts and | |
7189 | * re-starting the system. | |
7190 | * | |
7191 | * ONLY VALID WHEN THE WHOLE SYSTEM IS STOPPED! | |
7192 | */ | |
36c8b586 | 7193 | void set_curr_task(int cpu, struct task_struct *p) |
1df5c10a LT |
7194 | { |
7195 | cpu_curr(cpu) = p; | |
7196 | } | |
7197 | ||
7198 | #endif | |
29f59db3 | 7199 | |
7c941438 | 7200 | #ifdef CONFIG_CGROUP_SCHED |
029632fb PZ |
7201 | /* task_group_lock serializes the addition/removal of task groups */ |
7202 | static DEFINE_SPINLOCK(task_group_lock); | |
7203 | ||
bccbe08a PZ |
7204 | static void free_sched_group(struct task_group *tg) |
7205 | { | |
7206 | free_fair_sched_group(tg); | |
7207 | free_rt_sched_group(tg); | |
e9aa1dd1 | 7208 | autogroup_free(tg); |
bccbe08a PZ |
7209 | kfree(tg); |
7210 | } | |
7211 | ||
7212 | /* allocate runqueue etc for a new task group */ | |
ec7dc8ac | 7213 | struct task_group *sched_create_group(struct task_group *parent) |
bccbe08a PZ |
7214 | { |
7215 | struct task_group *tg; | |
bccbe08a PZ |
7216 | |
7217 | tg = kzalloc(sizeof(*tg), GFP_KERNEL); | |
7218 | if (!tg) | |
7219 | return ERR_PTR(-ENOMEM); | |
7220 | ||
ec7dc8ac | 7221 | if (!alloc_fair_sched_group(tg, parent)) |
bccbe08a PZ |
7222 | goto err; |
7223 | ||
ec7dc8ac | 7224 | if (!alloc_rt_sched_group(tg, parent)) |
bccbe08a PZ |
7225 | goto err; |
7226 | ||
ace783b9 LZ |
7227 | return tg; |
7228 | ||
7229 | err: | |
7230 | free_sched_group(tg); | |
7231 | return ERR_PTR(-ENOMEM); | |
7232 | } | |
7233 | ||
7234 | void sched_online_group(struct task_group *tg, struct task_group *parent) | |
7235 | { | |
7236 | unsigned long flags; | |
7237 | ||
8ed36996 | 7238 | spin_lock_irqsave(&task_group_lock, flags); |
6f505b16 | 7239 | list_add_rcu(&tg->list, &task_groups); |
f473aa5e PZ |
7240 | |
7241 | WARN_ON(!parent); /* root should already exist */ | |
7242 | ||
7243 | tg->parent = parent; | |
f473aa5e | 7244 | INIT_LIST_HEAD(&tg->children); |
09f2724a | 7245 | list_add_rcu(&tg->siblings, &parent->children); |
8ed36996 | 7246 | spin_unlock_irqrestore(&task_group_lock, flags); |
29f59db3 SV |
7247 | } |
7248 | ||
9b5b7751 | 7249 | /* rcu callback to free various structures associated with a task group */ |
6f505b16 | 7250 | static void free_sched_group_rcu(struct rcu_head *rhp) |
29f59db3 | 7251 | { |
29f59db3 | 7252 | /* now it should be safe to free those cfs_rqs */ |
6f505b16 | 7253 | free_sched_group(container_of(rhp, struct task_group, rcu)); |
29f59db3 SV |
7254 | } |
7255 | ||
9b5b7751 | 7256 | /* Destroy runqueue etc associated with a task group */ |
4cf86d77 | 7257 | void sched_destroy_group(struct task_group *tg) |
ace783b9 LZ |
7258 | { |
7259 | /* wait for possible concurrent references to cfs_rqs complete */ | |
7260 | call_rcu(&tg->rcu, free_sched_group_rcu); | |
7261 | } | |
7262 | ||
7263 | void sched_offline_group(struct task_group *tg) | |
29f59db3 | 7264 | { |
8ed36996 | 7265 | unsigned long flags; |
9b5b7751 | 7266 | int i; |
29f59db3 | 7267 | |
3d4b47b4 PZ |
7268 | /* end participation in shares distribution */ |
7269 | for_each_possible_cpu(i) | |
bccbe08a | 7270 | unregister_fair_sched_group(tg, i); |
3d4b47b4 PZ |
7271 | |
7272 | spin_lock_irqsave(&task_group_lock, flags); | |
6f505b16 | 7273 | list_del_rcu(&tg->list); |
f473aa5e | 7274 | list_del_rcu(&tg->siblings); |
8ed36996 | 7275 | spin_unlock_irqrestore(&task_group_lock, flags); |
29f59db3 SV |
7276 | } |
7277 | ||
9b5b7751 | 7278 | /* change task's runqueue when it moves between groups. |
3a252015 IM |
7279 | * The caller of this function should have put the task in its new group |
7280 | * by now. This function just updates tsk->se.cfs_rq and tsk->se.parent to | |
7281 | * reflect its new group. | |
9b5b7751 SV |
7282 | */ |
7283 | void sched_move_task(struct task_struct *tsk) | |
29f59db3 | 7284 | { |
8323f26c | 7285 | struct task_group *tg; |
29f59db3 SV |
7286 | int on_rq, running; |
7287 | unsigned long flags; | |
7288 | struct rq *rq; | |
7289 | ||
7290 | rq = task_rq_lock(tsk, &flags); | |
7291 | ||
051a1d1a | 7292 | running = task_current(rq, tsk); |
fd2f4419 | 7293 | on_rq = tsk->on_rq; |
29f59db3 | 7294 | |
0e1f3483 | 7295 | if (on_rq) |
29f59db3 | 7296 | dequeue_task(rq, tsk, 0); |
0e1f3483 HS |
7297 | if (unlikely(running)) |
7298 | tsk->sched_class->put_prev_task(rq, tsk); | |
29f59db3 | 7299 | |
073219e9 | 7300 | tg = container_of(task_css_check(tsk, cpu_cgrp_id, |
8323f26c PZ |
7301 | lockdep_is_held(&tsk->sighand->siglock)), |
7302 | struct task_group, css); | |
7303 | tg = autogroup_task_group(tsk, tg); | |
7304 | tsk->sched_task_group = tg; | |
7305 | ||
810b3817 | 7306 | #ifdef CONFIG_FAIR_GROUP_SCHED |
b2b5ce02 PZ |
7307 | if (tsk->sched_class->task_move_group) |
7308 | tsk->sched_class->task_move_group(tsk, on_rq); | |
7309 | else | |
810b3817 | 7310 | #endif |
b2b5ce02 | 7311 | set_task_rq(tsk, task_cpu(tsk)); |
810b3817 | 7312 | |
0e1f3483 HS |
7313 | if (unlikely(running)) |
7314 | tsk->sched_class->set_curr_task(rq); | |
7315 | if (on_rq) | |
371fd7e7 | 7316 | enqueue_task(rq, tsk, 0); |
29f59db3 | 7317 | |
0122ec5b | 7318 | task_rq_unlock(rq, tsk, &flags); |
29f59db3 | 7319 | } |
7c941438 | 7320 | #endif /* CONFIG_CGROUP_SCHED */ |
29f59db3 | 7321 | |
a790de99 PT |
7322 | #ifdef CONFIG_RT_GROUP_SCHED |
7323 | /* | |
7324 | * Ensure that the real time constraints are schedulable. | |
7325 | */ | |
7326 | static DEFINE_MUTEX(rt_constraints_mutex); | |
9f0c1e56 | 7327 | |
9a7e0b18 PZ |
7328 | /* Must be called with tasklist_lock held */ |
7329 | static inline int tg_has_rt_tasks(struct task_group *tg) | |
b40b2e8e | 7330 | { |
9a7e0b18 | 7331 | struct task_struct *g, *p; |
b40b2e8e | 7332 | |
9a7e0b18 | 7333 | do_each_thread(g, p) { |
029632fb | 7334 | if (rt_task(p) && task_rq(p)->rt.tg == tg) |
9a7e0b18 PZ |
7335 | return 1; |
7336 | } while_each_thread(g, p); | |
b40b2e8e | 7337 | |
9a7e0b18 PZ |
7338 | return 0; |
7339 | } | |
b40b2e8e | 7340 | |
9a7e0b18 PZ |
7341 | struct rt_schedulable_data { |
7342 | struct task_group *tg; | |
7343 | u64 rt_period; | |
7344 | u64 rt_runtime; | |
7345 | }; | |
b40b2e8e | 7346 | |
a790de99 | 7347 | static int tg_rt_schedulable(struct task_group *tg, void *data) |
9a7e0b18 PZ |
7348 | { |
7349 | struct rt_schedulable_data *d = data; | |
7350 | struct task_group *child; | |
7351 | unsigned long total, sum = 0; | |
7352 | u64 period, runtime; | |
b40b2e8e | 7353 | |
9a7e0b18 PZ |
7354 | period = ktime_to_ns(tg->rt_bandwidth.rt_period); |
7355 | runtime = tg->rt_bandwidth.rt_runtime; | |
b40b2e8e | 7356 | |
9a7e0b18 PZ |
7357 | if (tg == d->tg) { |
7358 | period = d->rt_period; | |
7359 | runtime = d->rt_runtime; | |
b40b2e8e | 7360 | } |
b40b2e8e | 7361 | |
4653f803 PZ |
7362 | /* |
7363 | * Cannot have more runtime than the period. | |
7364 | */ | |
7365 | if (runtime > period && runtime != RUNTIME_INF) | |
7366 | return -EINVAL; | |
6f505b16 | 7367 | |
4653f803 PZ |
7368 | /* |
7369 | * Ensure we don't starve existing RT tasks. | |
7370 | */ | |
9a7e0b18 PZ |
7371 | if (rt_bandwidth_enabled() && !runtime && tg_has_rt_tasks(tg)) |
7372 | return -EBUSY; | |
6f505b16 | 7373 | |
9a7e0b18 | 7374 | total = to_ratio(period, runtime); |
6f505b16 | 7375 | |
4653f803 PZ |
7376 | /* |
7377 | * Nobody can have more than the global setting allows. | |
7378 | */ | |
7379 | if (total > to_ratio(global_rt_period(), global_rt_runtime())) | |
7380 | return -EINVAL; | |
6f505b16 | 7381 | |
4653f803 PZ |
7382 | /* |
7383 | * The sum of our children's runtime should not exceed our own. | |
7384 | */ | |
9a7e0b18 PZ |
7385 | list_for_each_entry_rcu(child, &tg->children, siblings) { |
7386 | period = ktime_to_ns(child->rt_bandwidth.rt_period); | |
7387 | runtime = child->rt_bandwidth.rt_runtime; | |
6f505b16 | 7388 | |
9a7e0b18 PZ |
7389 | if (child == d->tg) { |
7390 | period = d->rt_period; | |
7391 | runtime = d->rt_runtime; | |
7392 | } | |
6f505b16 | 7393 | |
9a7e0b18 | 7394 | sum += to_ratio(period, runtime); |
9f0c1e56 | 7395 | } |
6f505b16 | 7396 | |
9a7e0b18 PZ |
7397 | if (sum > total) |
7398 | return -EINVAL; | |
7399 | ||
7400 | return 0; | |
6f505b16 PZ |
7401 | } |
7402 | ||
9a7e0b18 | 7403 | static int __rt_schedulable(struct task_group *tg, u64 period, u64 runtime) |
521f1a24 | 7404 | { |
8277434e PT |
7405 | int ret; |
7406 | ||
9a7e0b18 PZ |
7407 | struct rt_schedulable_data data = { |
7408 | .tg = tg, | |
7409 | .rt_period = period, | |
7410 | .rt_runtime = runtime, | |
7411 | }; | |
7412 | ||
8277434e PT |
7413 | rcu_read_lock(); |
7414 | ret = walk_tg_tree(tg_rt_schedulable, tg_nop, &data); | |
7415 | rcu_read_unlock(); | |
7416 | ||
7417 | return ret; | |
521f1a24 DG |
7418 | } |
7419 | ||
ab84d31e | 7420 | static int tg_set_rt_bandwidth(struct task_group *tg, |
d0b27fa7 | 7421 | u64 rt_period, u64 rt_runtime) |
6f505b16 | 7422 | { |
ac086bc2 | 7423 | int i, err = 0; |
9f0c1e56 | 7424 | |
9f0c1e56 | 7425 | mutex_lock(&rt_constraints_mutex); |
521f1a24 | 7426 | read_lock(&tasklist_lock); |
9a7e0b18 PZ |
7427 | err = __rt_schedulable(tg, rt_period, rt_runtime); |
7428 | if (err) | |
9f0c1e56 | 7429 | goto unlock; |
ac086bc2 | 7430 | |
0986b11b | 7431 | raw_spin_lock_irq(&tg->rt_bandwidth.rt_runtime_lock); |
d0b27fa7 PZ |
7432 | tg->rt_bandwidth.rt_period = ns_to_ktime(rt_period); |
7433 | tg->rt_bandwidth.rt_runtime = rt_runtime; | |
ac086bc2 PZ |
7434 | |
7435 | for_each_possible_cpu(i) { | |
7436 | struct rt_rq *rt_rq = tg->rt_rq[i]; | |
7437 | ||
0986b11b | 7438 | raw_spin_lock(&rt_rq->rt_runtime_lock); |
ac086bc2 | 7439 | rt_rq->rt_runtime = rt_runtime; |
0986b11b | 7440 | raw_spin_unlock(&rt_rq->rt_runtime_lock); |
ac086bc2 | 7441 | } |
0986b11b | 7442 | raw_spin_unlock_irq(&tg->rt_bandwidth.rt_runtime_lock); |
49246274 | 7443 | unlock: |
521f1a24 | 7444 | read_unlock(&tasklist_lock); |
9f0c1e56 PZ |
7445 | mutex_unlock(&rt_constraints_mutex); |
7446 | ||
7447 | return err; | |
6f505b16 PZ |
7448 | } |
7449 | ||
25cc7da7 | 7450 | static int sched_group_set_rt_runtime(struct task_group *tg, long rt_runtime_us) |
d0b27fa7 PZ |
7451 | { |
7452 | u64 rt_runtime, rt_period; | |
7453 | ||
7454 | rt_period = ktime_to_ns(tg->rt_bandwidth.rt_period); | |
7455 | rt_runtime = (u64)rt_runtime_us * NSEC_PER_USEC; | |
7456 | if (rt_runtime_us < 0) | |
7457 | rt_runtime = RUNTIME_INF; | |
7458 | ||
ab84d31e | 7459 | return tg_set_rt_bandwidth(tg, rt_period, rt_runtime); |
d0b27fa7 PZ |
7460 | } |
7461 | ||
25cc7da7 | 7462 | static long sched_group_rt_runtime(struct task_group *tg) |
9f0c1e56 PZ |
7463 | { |
7464 | u64 rt_runtime_us; | |
7465 | ||
d0b27fa7 | 7466 | if (tg->rt_bandwidth.rt_runtime == RUNTIME_INF) |
9f0c1e56 PZ |
7467 | return -1; |
7468 | ||
d0b27fa7 | 7469 | rt_runtime_us = tg->rt_bandwidth.rt_runtime; |
9f0c1e56 PZ |
7470 | do_div(rt_runtime_us, NSEC_PER_USEC); |
7471 | return rt_runtime_us; | |
7472 | } | |
d0b27fa7 | 7473 | |
25cc7da7 | 7474 | static int sched_group_set_rt_period(struct task_group *tg, long rt_period_us) |
d0b27fa7 PZ |
7475 | { |
7476 | u64 rt_runtime, rt_period; | |
7477 | ||
7478 | rt_period = (u64)rt_period_us * NSEC_PER_USEC; | |
7479 | rt_runtime = tg->rt_bandwidth.rt_runtime; | |
7480 | ||
619b0488 R |
7481 | if (rt_period == 0) |
7482 | return -EINVAL; | |
7483 | ||
ab84d31e | 7484 | return tg_set_rt_bandwidth(tg, rt_period, rt_runtime); |
d0b27fa7 PZ |
7485 | } |
7486 | ||
25cc7da7 | 7487 | static long sched_group_rt_period(struct task_group *tg) |
d0b27fa7 PZ |
7488 | { |
7489 | u64 rt_period_us; | |
7490 | ||
7491 | rt_period_us = ktime_to_ns(tg->rt_bandwidth.rt_period); | |
7492 | do_div(rt_period_us, NSEC_PER_USEC); | |
7493 | return rt_period_us; | |
7494 | } | |
332ac17e | 7495 | #endif /* CONFIG_RT_GROUP_SCHED */ |
d0b27fa7 | 7496 | |
332ac17e | 7497 | #ifdef CONFIG_RT_GROUP_SCHED |
d0b27fa7 PZ |
7498 | static int sched_rt_global_constraints(void) |
7499 | { | |
7500 | int ret = 0; | |
7501 | ||
7502 | mutex_lock(&rt_constraints_mutex); | |
9a7e0b18 | 7503 | read_lock(&tasklist_lock); |
4653f803 | 7504 | ret = __rt_schedulable(NULL, 0, 0); |
9a7e0b18 | 7505 | read_unlock(&tasklist_lock); |
d0b27fa7 PZ |
7506 | mutex_unlock(&rt_constraints_mutex); |
7507 | ||
7508 | return ret; | |
7509 | } | |
54e99124 | 7510 | |
25cc7da7 | 7511 | static int sched_rt_can_attach(struct task_group *tg, struct task_struct *tsk) |
54e99124 DG |
7512 | { |
7513 | /* Don't accept realtime tasks when there is no way for them to run */ | |
7514 | if (rt_task(tsk) && tg->rt_bandwidth.rt_runtime == 0) | |
7515 | return 0; | |
7516 | ||
7517 | return 1; | |
7518 | } | |
7519 | ||
6d6bc0ad | 7520 | #else /* !CONFIG_RT_GROUP_SCHED */ |
d0b27fa7 PZ |
7521 | static int sched_rt_global_constraints(void) |
7522 | { | |
ac086bc2 | 7523 | unsigned long flags; |
332ac17e | 7524 | int i, ret = 0; |
ec5d4989 | 7525 | |
0986b11b | 7526 | raw_spin_lock_irqsave(&def_rt_bandwidth.rt_runtime_lock, flags); |
ac086bc2 PZ |
7527 | for_each_possible_cpu(i) { |
7528 | struct rt_rq *rt_rq = &cpu_rq(i)->rt; | |
7529 | ||
0986b11b | 7530 | raw_spin_lock(&rt_rq->rt_runtime_lock); |
ac086bc2 | 7531 | rt_rq->rt_runtime = global_rt_runtime(); |
0986b11b | 7532 | raw_spin_unlock(&rt_rq->rt_runtime_lock); |
ac086bc2 | 7533 | } |
0986b11b | 7534 | raw_spin_unlock_irqrestore(&def_rt_bandwidth.rt_runtime_lock, flags); |
ac086bc2 | 7535 | |
332ac17e | 7536 | return ret; |
d0b27fa7 | 7537 | } |
6d6bc0ad | 7538 | #endif /* CONFIG_RT_GROUP_SCHED */ |
d0b27fa7 | 7539 | |
332ac17e DF |
7540 | static int sched_dl_global_constraints(void) |
7541 | { | |
1724813d PZ |
7542 | u64 runtime = global_rt_runtime(); |
7543 | u64 period = global_rt_period(); | |
332ac17e | 7544 | u64 new_bw = to_ratio(period, runtime); |
1724813d | 7545 | int cpu, ret = 0; |
49516342 | 7546 | unsigned long flags; |
332ac17e DF |
7547 | |
7548 | /* | |
7549 | * Here we want to check the bandwidth not being set to some | |
7550 | * value smaller than the currently allocated bandwidth in | |
7551 | * any of the root_domains. | |
7552 | * | |
7553 | * FIXME: Cycling on all the CPUs is overdoing, but simpler than | |
7554 | * cycling on root_domains... Discussion on different/better | |
7555 | * solutions is welcome! | |
7556 | */ | |
1724813d PZ |
7557 | for_each_possible_cpu(cpu) { |
7558 | struct dl_bw *dl_b = dl_bw_of(cpu); | |
332ac17e | 7559 | |
49516342 | 7560 | raw_spin_lock_irqsave(&dl_b->lock, flags); |
1724813d PZ |
7561 | if (new_bw < dl_b->total_bw) |
7562 | ret = -EBUSY; | |
49516342 | 7563 | raw_spin_unlock_irqrestore(&dl_b->lock, flags); |
1724813d PZ |
7564 | |
7565 | if (ret) | |
7566 | break; | |
332ac17e DF |
7567 | } |
7568 | ||
1724813d | 7569 | return ret; |
332ac17e DF |
7570 | } |
7571 | ||
1724813d | 7572 | static void sched_dl_do_global(void) |
ce0dbbbb | 7573 | { |
1724813d PZ |
7574 | u64 new_bw = -1; |
7575 | int cpu; | |
49516342 | 7576 | unsigned long flags; |
ce0dbbbb | 7577 | |
1724813d PZ |
7578 | def_dl_bandwidth.dl_period = global_rt_period(); |
7579 | def_dl_bandwidth.dl_runtime = global_rt_runtime(); | |
7580 | ||
7581 | if (global_rt_runtime() != RUNTIME_INF) | |
7582 | new_bw = to_ratio(global_rt_period(), global_rt_runtime()); | |
7583 | ||
7584 | /* | |
7585 | * FIXME: As above... | |
7586 | */ | |
7587 | for_each_possible_cpu(cpu) { | |
7588 | struct dl_bw *dl_b = dl_bw_of(cpu); | |
7589 | ||
49516342 | 7590 | raw_spin_lock_irqsave(&dl_b->lock, flags); |
1724813d | 7591 | dl_b->bw = new_bw; |
49516342 | 7592 | raw_spin_unlock_irqrestore(&dl_b->lock, flags); |
ce0dbbbb | 7593 | } |
1724813d PZ |
7594 | } |
7595 | ||
7596 | static int sched_rt_global_validate(void) | |
7597 | { | |
7598 | if (sysctl_sched_rt_period <= 0) | |
7599 | return -EINVAL; | |
7600 | ||
e9e7cb38 JL |
7601 | if ((sysctl_sched_rt_runtime != RUNTIME_INF) && |
7602 | (sysctl_sched_rt_runtime > sysctl_sched_rt_period)) | |
1724813d PZ |
7603 | return -EINVAL; |
7604 | ||
7605 | return 0; | |
7606 | } | |
7607 | ||
7608 | static void sched_rt_do_global(void) | |
7609 | { | |
7610 | def_rt_bandwidth.rt_runtime = global_rt_runtime(); | |
7611 | def_rt_bandwidth.rt_period = ns_to_ktime(global_rt_period()); | |
ce0dbbbb CW |
7612 | } |
7613 | ||
d0b27fa7 | 7614 | int sched_rt_handler(struct ctl_table *table, int write, |
8d65af78 | 7615 | void __user *buffer, size_t *lenp, |
d0b27fa7 PZ |
7616 | loff_t *ppos) |
7617 | { | |
d0b27fa7 PZ |
7618 | int old_period, old_runtime; |
7619 | static DEFINE_MUTEX(mutex); | |
1724813d | 7620 | int ret; |
d0b27fa7 PZ |
7621 | |
7622 | mutex_lock(&mutex); | |
7623 | old_period = sysctl_sched_rt_period; | |
7624 | old_runtime = sysctl_sched_rt_runtime; | |
7625 | ||
8d65af78 | 7626 | ret = proc_dointvec(table, write, buffer, lenp, ppos); |
d0b27fa7 PZ |
7627 | |
7628 | if (!ret && write) { | |
1724813d PZ |
7629 | ret = sched_rt_global_validate(); |
7630 | if (ret) | |
7631 | goto undo; | |
7632 | ||
d0b27fa7 | 7633 | ret = sched_rt_global_constraints(); |
1724813d PZ |
7634 | if (ret) |
7635 | goto undo; | |
7636 | ||
7637 | ret = sched_dl_global_constraints(); | |
7638 | if (ret) | |
7639 | goto undo; | |
7640 | ||
7641 | sched_rt_do_global(); | |
7642 | sched_dl_do_global(); | |
7643 | } | |
7644 | if (0) { | |
7645 | undo: | |
7646 | sysctl_sched_rt_period = old_period; | |
7647 | sysctl_sched_rt_runtime = old_runtime; | |
d0b27fa7 PZ |
7648 | } |
7649 | mutex_unlock(&mutex); | |
7650 | ||
7651 | return ret; | |
7652 | } | |
68318b8e | 7653 | |
1724813d | 7654 | int sched_rr_handler(struct ctl_table *table, int write, |
332ac17e DF |
7655 | void __user *buffer, size_t *lenp, |
7656 | loff_t *ppos) | |
7657 | { | |
7658 | int ret; | |
332ac17e | 7659 | static DEFINE_MUTEX(mutex); |
332ac17e DF |
7660 | |
7661 | mutex_lock(&mutex); | |
332ac17e | 7662 | ret = proc_dointvec(table, write, buffer, lenp, ppos); |
1724813d PZ |
7663 | /* make sure that internally we keep jiffies */ |
7664 | /* also, writing zero resets timeslice to default */ | |
332ac17e | 7665 | if (!ret && write) { |
1724813d PZ |
7666 | sched_rr_timeslice = sched_rr_timeslice <= 0 ? |
7667 | RR_TIMESLICE : msecs_to_jiffies(sched_rr_timeslice); | |
332ac17e DF |
7668 | } |
7669 | mutex_unlock(&mutex); | |
332ac17e DF |
7670 | return ret; |
7671 | } | |
7672 | ||
052f1dc7 | 7673 | #ifdef CONFIG_CGROUP_SCHED |
68318b8e | 7674 | |
a7c6d554 | 7675 | static inline struct task_group *css_tg(struct cgroup_subsys_state *css) |
68318b8e | 7676 | { |
a7c6d554 | 7677 | return css ? container_of(css, struct task_group, css) : NULL; |
68318b8e SV |
7678 | } |
7679 | ||
eb95419b TH |
7680 | static struct cgroup_subsys_state * |
7681 | cpu_cgroup_css_alloc(struct cgroup_subsys_state *parent_css) | |
68318b8e | 7682 | { |
eb95419b TH |
7683 | struct task_group *parent = css_tg(parent_css); |
7684 | struct task_group *tg; | |
68318b8e | 7685 | |
eb95419b | 7686 | if (!parent) { |
68318b8e | 7687 | /* This is early initialization for the top cgroup */ |
07e06b01 | 7688 | return &root_task_group.css; |
68318b8e SV |
7689 | } |
7690 | ||
ec7dc8ac | 7691 | tg = sched_create_group(parent); |
68318b8e SV |
7692 | if (IS_ERR(tg)) |
7693 | return ERR_PTR(-ENOMEM); | |
7694 | ||
68318b8e SV |
7695 | return &tg->css; |
7696 | } | |
7697 | ||
eb95419b | 7698 | static int cpu_cgroup_css_online(struct cgroup_subsys_state *css) |
ace783b9 | 7699 | { |
eb95419b | 7700 | struct task_group *tg = css_tg(css); |
5c9d535b | 7701 | struct task_group *parent = css_tg(css->parent); |
ace783b9 | 7702 | |
63876986 TH |
7703 | if (parent) |
7704 | sched_online_group(tg, parent); | |
ace783b9 LZ |
7705 | return 0; |
7706 | } | |
7707 | ||
eb95419b | 7708 | static void cpu_cgroup_css_free(struct cgroup_subsys_state *css) |
68318b8e | 7709 | { |
eb95419b | 7710 | struct task_group *tg = css_tg(css); |
68318b8e SV |
7711 | |
7712 | sched_destroy_group(tg); | |
7713 | } | |
7714 | ||
eb95419b | 7715 | static void cpu_cgroup_css_offline(struct cgroup_subsys_state *css) |
ace783b9 | 7716 | { |
eb95419b | 7717 | struct task_group *tg = css_tg(css); |
ace783b9 LZ |
7718 | |
7719 | sched_offline_group(tg); | |
7720 | } | |
7721 | ||
eb95419b | 7722 | static int cpu_cgroup_can_attach(struct cgroup_subsys_state *css, |
bb9d97b6 | 7723 | struct cgroup_taskset *tset) |
68318b8e | 7724 | { |
bb9d97b6 TH |
7725 | struct task_struct *task; |
7726 | ||
924f0d9a | 7727 | cgroup_taskset_for_each(task, tset) { |
b68aa230 | 7728 | #ifdef CONFIG_RT_GROUP_SCHED |
eb95419b | 7729 | if (!sched_rt_can_attach(css_tg(css), task)) |
bb9d97b6 | 7730 | return -EINVAL; |
b68aa230 | 7731 | #else |
bb9d97b6 TH |
7732 | /* We don't support RT-tasks being in separate groups */ |
7733 | if (task->sched_class != &fair_sched_class) | |
7734 | return -EINVAL; | |
b68aa230 | 7735 | #endif |
bb9d97b6 | 7736 | } |
be367d09 BB |
7737 | return 0; |
7738 | } | |
68318b8e | 7739 | |
eb95419b | 7740 | static void cpu_cgroup_attach(struct cgroup_subsys_state *css, |
bb9d97b6 | 7741 | struct cgroup_taskset *tset) |
68318b8e | 7742 | { |
bb9d97b6 TH |
7743 | struct task_struct *task; |
7744 | ||
924f0d9a | 7745 | cgroup_taskset_for_each(task, tset) |
bb9d97b6 | 7746 | sched_move_task(task); |
68318b8e SV |
7747 | } |
7748 | ||
eb95419b TH |
7749 | static void cpu_cgroup_exit(struct cgroup_subsys_state *css, |
7750 | struct cgroup_subsys_state *old_css, | |
7751 | struct task_struct *task) | |
068c5cc5 PZ |
7752 | { |
7753 | /* | |
7754 | * cgroup_exit() is called in the copy_process() failure path. | |
7755 | * Ignore this case since the task hasn't ran yet, this avoids | |
7756 | * trying to poke a half freed task state from generic code. | |
7757 | */ | |
7758 | if (!(task->flags & PF_EXITING)) | |
7759 | return; | |
7760 | ||
7761 | sched_move_task(task); | |
7762 | } | |
7763 | ||
052f1dc7 | 7764 | #ifdef CONFIG_FAIR_GROUP_SCHED |
182446d0 TH |
7765 | static int cpu_shares_write_u64(struct cgroup_subsys_state *css, |
7766 | struct cftype *cftype, u64 shareval) | |
68318b8e | 7767 | { |
182446d0 | 7768 | return sched_group_set_shares(css_tg(css), scale_load(shareval)); |
68318b8e SV |
7769 | } |
7770 | ||
182446d0 TH |
7771 | static u64 cpu_shares_read_u64(struct cgroup_subsys_state *css, |
7772 | struct cftype *cft) | |
68318b8e | 7773 | { |
182446d0 | 7774 | struct task_group *tg = css_tg(css); |
68318b8e | 7775 | |
c8b28116 | 7776 | return (u64) scale_load_down(tg->shares); |
68318b8e | 7777 | } |
ab84d31e PT |
7778 | |
7779 | #ifdef CONFIG_CFS_BANDWIDTH | |
a790de99 PT |
7780 | static DEFINE_MUTEX(cfs_constraints_mutex); |
7781 | ||
ab84d31e PT |
7782 | const u64 max_cfs_quota_period = 1 * NSEC_PER_SEC; /* 1s */ |
7783 | const u64 min_cfs_quota_period = 1 * NSEC_PER_MSEC; /* 1ms */ | |
7784 | ||
a790de99 PT |
7785 | static int __cfs_schedulable(struct task_group *tg, u64 period, u64 runtime); |
7786 | ||
ab84d31e PT |
7787 | static int tg_set_cfs_bandwidth(struct task_group *tg, u64 period, u64 quota) |
7788 | { | |
56f570e5 | 7789 | int i, ret = 0, runtime_enabled, runtime_was_enabled; |
029632fb | 7790 | struct cfs_bandwidth *cfs_b = &tg->cfs_bandwidth; |
ab84d31e PT |
7791 | |
7792 | if (tg == &root_task_group) | |
7793 | return -EINVAL; | |
7794 | ||
7795 | /* | |
7796 | * Ensure we have at some amount of bandwidth every period. This is | |
7797 | * to prevent reaching a state of large arrears when throttled via | |
7798 | * entity_tick() resulting in prolonged exit starvation. | |
7799 | */ | |
7800 | if (quota < min_cfs_quota_period || period < min_cfs_quota_period) | |
7801 | return -EINVAL; | |
7802 | ||
7803 | /* | |
7804 | * Likewise, bound things on the otherside by preventing insane quota | |
7805 | * periods. This also allows us to normalize in computing quota | |
7806 | * feasibility. | |
7807 | */ | |
7808 | if (period > max_cfs_quota_period) | |
7809 | return -EINVAL; | |
7810 | ||
a790de99 PT |
7811 | mutex_lock(&cfs_constraints_mutex); |
7812 | ret = __cfs_schedulable(tg, period, quota); | |
7813 | if (ret) | |
7814 | goto out_unlock; | |
7815 | ||
58088ad0 | 7816 | runtime_enabled = quota != RUNTIME_INF; |
56f570e5 | 7817 | runtime_was_enabled = cfs_b->quota != RUNTIME_INF; |
1ee14e6c BS |
7818 | /* |
7819 | * If we need to toggle cfs_bandwidth_used, off->on must occur | |
7820 | * before making related changes, and on->off must occur afterwards | |
7821 | */ | |
7822 | if (runtime_enabled && !runtime_was_enabled) | |
7823 | cfs_bandwidth_usage_inc(); | |
ab84d31e PT |
7824 | raw_spin_lock_irq(&cfs_b->lock); |
7825 | cfs_b->period = ns_to_ktime(period); | |
7826 | cfs_b->quota = quota; | |
58088ad0 | 7827 | |
a9cf55b2 | 7828 | __refill_cfs_bandwidth_runtime(cfs_b); |
58088ad0 PT |
7829 | /* restart the period timer (if active) to handle new period expiry */ |
7830 | if (runtime_enabled && cfs_b->timer_active) { | |
7831 | /* force a reprogram */ | |
09dc4ab0 | 7832 | __start_cfs_bandwidth(cfs_b, true); |
58088ad0 | 7833 | } |
ab84d31e PT |
7834 | raw_spin_unlock_irq(&cfs_b->lock); |
7835 | ||
7836 | for_each_possible_cpu(i) { | |
7837 | struct cfs_rq *cfs_rq = tg->cfs_rq[i]; | |
029632fb | 7838 | struct rq *rq = cfs_rq->rq; |
ab84d31e PT |
7839 | |
7840 | raw_spin_lock_irq(&rq->lock); | |
58088ad0 | 7841 | cfs_rq->runtime_enabled = runtime_enabled; |
ab84d31e | 7842 | cfs_rq->runtime_remaining = 0; |
671fd9da | 7843 | |
029632fb | 7844 | if (cfs_rq->throttled) |
671fd9da | 7845 | unthrottle_cfs_rq(cfs_rq); |
ab84d31e PT |
7846 | raw_spin_unlock_irq(&rq->lock); |
7847 | } | |
1ee14e6c BS |
7848 | if (runtime_was_enabled && !runtime_enabled) |
7849 | cfs_bandwidth_usage_dec(); | |
a790de99 PT |
7850 | out_unlock: |
7851 | mutex_unlock(&cfs_constraints_mutex); | |
ab84d31e | 7852 | |
a790de99 | 7853 | return ret; |
ab84d31e PT |
7854 | } |
7855 | ||
7856 | int tg_set_cfs_quota(struct task_group *tg, long cfs_quota_us) | |
7857 | { | |
7858 | u64 quota, period; | |
7859 | ||
029632fb | 7860 | period = ktime_to_ns(tg->cfs_bandwidth.period); |
ab84d31e PT |
7861 | if (cfs_quota_us < 0) |
7862 | quota = RUNTIME_INF; | |
7863 | else | |
7864 | quota = (u64)cfs_quota_us * NSEC_PER_USEC; | |
7865 | ||
7866 | return tg_set_cfs_bandwidth(tg, period, quota); | |
7867 | } | |
7868 | ||
7869 | long tg_get_cfs_quota(struct task_group *tg) | |
7870 | { | |
7871 | u64 quota_us; | |
7872 | ||
029632fb | 7873 | if (tg->cfs_bandwidth.quota == RUNTIME_INF) |
ab84d31e PT |
7874 | return -1; |
7875 | ||
029632fb | 7876 | quota_us = tg->cfs_bandwidth.quota; |
ab84d31e PT |
7877 | do_div(quota_us, NSEC_PER_USEC); |
7878 | ||
7879 | return quota_us; | |
7880 | } | |
7881 | ||
7882 | int tg_set_cfs_period(struct task_group *tg, long cfs_period_us) | |
7883 | { | |
7884 | u64 quota, period; | |
7885 | ||
7886 | period = (u64)cfs_period_us * NSEC_PER_USEC; | |
029632fb | 7887 | quota = tg->cfs_bandwidth.quota; |
ab84d31e | 7888 | |
ab84d31e PT |
7889 | return tg_set_cfs_bandwidth(tg, period, quota); |
7890 | } | |
7891 | ||
7892 | long tg_get_cfs_period(struct task_group *tg) | |
7893 | { | |
7894 | u64 cfs_period_us; | |
7895 | ||
029632fb | 7896 | cfs_period_us = ktime_to_ns(tg->cfs_bandwidth.period); |
ab84d31e PT |
7897 | do_div(cfs_period_us, NSEC_PER_USEC); |
7898 | ||
7899 | return cfs_period_us; | |
7900 | } | |
7901 | ||
182446d0 TH |
7902 | static s64 cpu_cfs_quota_read_s64(struct cgroup_subsys_state *css, |
7903 | struct cftype *cft) | |
ab84d31e | 7904 | { |
182446d0 | 7905 | return tg_get_cfs_quota(css_tg(css)); |
ab84d31e PT |
7906 | } |
7907 | ||
182446d0 TH |
7908 | static int cpu_cfs_quota_write_s64(struct cgroup_subsys_state *css, |
7909 | struct cftype *cftype, s64 cfs_quota_us) | |
ab84d31e | 7910 | { |
182446d0 | 7911 | return tg_set_cfs_quota(css_tg(css), cfs_quota_us); |
ab84d31e PT |
7912 | } |
7913 | ||
182446d0 TH |
7914 | static u64 cpu_cfs_period_read_u64(struct cgroup_subsys_state *css, |
7915 | struct cftype *cft) | |
ab84d31e | 7916 | { |
182446d0 | 7917 | return tg_get_cfs_period(css_tg(css)); |
ab84d31e PT |
7918 | } |
7919 | ||
182446d0 TH |
7920 | static int cpu_cfs_period_write_u64(struct cgroup_subsys_state *css, |
7921 | struct cftype *cftype, u64 cfs_period_us) | |
ab84d31e | 7922 | { |
182446d0 | 7923 | return tg_set_cfs_period(css_tg(css), cfs_period_us); |
ab84d31e PT |
7924 | } |
7925 | ||
a790de99 PT |
7926 | struct cfs_schedulable_data { |
7927 | struct task_group *tg; | |
7928 | u64 period, quota; | |
7929 | }; | |
7930 | ||
7931 | /* | |
7932 | * normalize group quota/period to be quota/max_period | |
7933 | * note: units are usecs | |
7934 | */ | |
7935 | static u64 normalize_cfs_quota(struct task_group *tg, | |
7936 | struct cfs_schedulable_data *d) | |
7937 | { | |
7938 | u64 quota, period; | |
7939 | ||
7940 | if (tg == d->tg) { | |
7941 | period = d->period; | |
7942 | quota = d->quota; | |
7943 | } else { | |
7944 | period = tg_get_cfs_period(tg); | |
7945 | quota = tg_get_cfs_quota(tg); | |
7946 | } | |
7947 | ||
7948 | /* note: these should typically be equivalent */ | |
7949 | if (quota == RUNTIME_INF || quota == -1) | |
7950 | return RUNTIME_INF; | |
7951 | ||
7952 | return to_ratio(period, quota); | |
7953 | } | |
7954 | ||
7955 | static int tg_cfs_schedulable_down(struct task_group *tg, void *data) | |
7956 | { | |
7957 | struct cfs_schedulable_data *d = data; | |
029632fb | 7958 | struct cfs_bandwidth *cfs_b = &tg->cfs_bandwidth; |
a790de99 PT |
7959 | s64 quota = 0, parent_quota = -1; |
7960 | ||
7961 | if (!tg->parent) { | |
7962 | quota = RUNTIME_INF; | |
7963 | } else { | |
029632fb | 7964 | struct cfs_bandwidth *parent_b = &tg->parent->cfs_bandwidth; |
a790de99 PT |
7965 | |
7966 | quota = normalize_cfs_quota(tg, d); | |
7967 | parent_quota = parent_b->hierarchal_quota; | |
7968 | ||
7969 | /* | |
7970 | * ensure max(child_quota) <= parent_quota, inherit when no | |
7971 | * limit is set | |
7972 | */ | |
7973 | if (quota == RUNTIME_INF) | |
7974 | quota = parent_quota; | |
7975 | else if (parent_quota != RUNTIME_INF && quota > parent_quota) | |
7976 | return -EINVAL; | |
7977 | } | |
7978 | cfs_b->hierarchal_quota = quota; | |
7979 | ||
7980 | return 0; | |
7981 | } | |
7982 | ||
7983 | static int __cfs_schedulable(struct task_group *tg, u64 period, u64 quota) | |
7984 | { | |
8277434e | 7985 | int ret; |
a790de99 PT |
7986 | struct cfs_schedulable_data data = { |
7987 | .tg = tg, | |
7988 | .period = period, | |
7989 | .quota = quota, | |
7990 | }; | |
7991 | ||
7992 | if (quota != RUNTIME_INF) { | |
7993 | do_div(data.period, NSEC_PER_USEC); | |
7994 | do_div(data.quota, NSEC_PER_USEC); | |
7995 | } | |
7996 | ||
8277434e PT |
7997 | rcu_read_lock(); |
7998 | ret = walk_tg_tree(tg_cfs_schedulable_down, tg_nop, &data); | |
7999 | rcu_read_unlock(); | |
8000 | ||
8001 | return ret; | |
a790de99 | 8002 | } |
e8da1b18 | 8003 | |
2da8ca82 | 8004 | static int cpu_stats_show(struct seq_file *sf, void *v) |
e8da1b18 | 8005 | { |
2da8ca82 | 8006 | struct task_group *tg = css_tg(seq_css(sf)); |
029632fb | 8007 | struct cfs_bandwidth *cfs_b = &tg->cfs_bandwidth; |
e8da1b18 | 8008 | |
44ffc75b TH |
8009 | seq_printf(sf, "nr_periods %d\n", cfs_b->nr_periods); |
8010 | seq_printf(sf, "nr_throttled %d\n", cfs_b->nr_throttled); | |
8011 | seq_printf(sf, "throttled_time %llu\n", cfs_b->throttled_time); | |
e8da1b18 NR |
8012 | |
8013 | return 0; | |
8014 | } | |
ab84d31e | 8015 | #endif /* CONFIG_CFS_BANDWIDTH */ |
6d6bc0ad | 8016 | #endif /* CONFIG_FAIR_GROUP_SCHED */ |
68318b8e | 8017 | |
052f1dc7 | 8018 | #ifdef CONFIG_RT_GROUP_SCHED |
182446d0 TH |
8019 | static int cpu_rt_runtime_write(struct cgroup_subsys_state *css, |
8020 | struct cftype *cft, s64 val) | |
6f505b16 | 8021 | { |
182446d0 | 8022 | return sched_group_set_rt_runtime(css_tg(css), val); |
6f505b16 PZ |
8023 | } |
8024 | ||
182446d0 TH |
8025 | static s64 cpu_rt_runtime_read(struct cgroup_subsys_state *css, |
8026 | struct cftype *cft) | |
6f505b16 | 8027 | { |
182446d0 | 8028 | return sched_group_rt_runtime(css_tg(css)); |
6f505b16 | 8029 | } |
d0b27fa7 | 8030 | |
182446d0 TH |
8031 | static int cpu_rt_period_write_uint(struct cgroup_subsys_state *css, |
8032 | struct cftype *cftype, u64 rt_period_us) | |
d0b27fa7 | 8033 | { |
182446d0 | 8034 | return sched_group_set_rt_period(css_tg(css), rt_period_us); |
d0b27fa7 PZ |
8035 | } |
8036 | ||
182446d0 TH |
8037 | static u64 cpu_rt_period_read_uint(struct cgroup_subsys_state *css, |
8038 | struct cftype *cft) | |
d0b27fa7 | 8039 | { |
182446d0 | 8040 | return sched_group_rt_period(css_tg(css)); |
d0b27fa7 | 8041 | } |
6d6bc0ad | 8042 | #endif /* CONFIG_RT_GROUP_SCHED */ |
6f505b16 | 8043 | |
fe5c7cc2 | 8044 | static struct cftype cpu_files[] = { |
052f1dc7 | 8045 | #ifdef CONFIG_FAIR_GROUP_SCHED |
fe5c7cc2 PM |
8046 | { |
8047 | .name = "shares", | |
f4c753b7 PM |
8048 | .read_u64 = cpu_shares_read_u64, |
8049 | .write_u64 = cpu_shares_write_u64, | |
fe5c7cc2 | 8050 | }, |
052f1dc7 | 8051 | #endif |
ab84d31e PT |
8052 | #ifdef CONFIG_CFS_BANDWIDTH |
8053 | { | |
8054 | .name = "cfs_quota_us", | |
8055 | .read_s64 = cpu_cfs_quota_read_s64, | |
8056 | .write_s64 = cpu_cfs_quota_write_s64, | |
8057 | }, | |
8058 | { | |
8059 | .name = "cfs_period_us", | |
8060 | .read_u64 = cpu_cfs_period_read_u64, | |
8061 | .write_u64 = cpu_cfs_period_write_u64, | |
8062 | }, | |
e8da1b18 NR |
8063 | { |
8064 | .name = "stat", | |
2da8ca82 | 8065 | .seq_show = cpu_stats_show, |
e8da1b18 | 8066 | }, |
ab84d31e | 8067 | #endif |
052f1dc7 | 8068 | #ifdef CONFIG_RT_GROUP_SCHED |
6f505b16 | 8069 | { |
9f0c1e56 | 8070 | .name = "rt_runtime_us", |
06ecb27c PM |
8071 | .read_s64 = cpu_rt_runtime_read, |
8072 | .write_s64 = cpu_rt_runtime_write, | |
6f505b16 | 8073 | }, |
d0b27fa7 PZ |
8074 | { |
8075 | .name = "rt_period_us", | |
f4c753b7 PM |
8076 | .read_u64 = cpu_rt_period_read_uint, |
8077 | .write_u64 = cpu_rt_period_write_uint, | |
d0b27fa7 | 8078 | }, |
052f1dc7 | 8079 | #endif |
4baf6e33 | 8080 | { } /* terminate */ |
68318b8e SV |
8081 | }; |
8082 | ||
073219e9 | 8083 | struct cgroup_subsys cpu_cgrp_subsys = { |
92fb9748 TH |
8084 | .css_alloc = cpu_cgroup_css_alloc, |
8085 | .css_free = cpu_cgroup_css_free, | |
ace783b9 LZ |
8086 | .css_online = cpu_cgroup_css_online, |
8087 | .css_offline = cpu_cgroup_css_offline, | |
bb9d97b6 TH |
8088 | .can_attach = cpu_cgroup_can_attach, |
8089 | .attach = cpu_cgroup_attach, | |
068c5cc5 | 8090 | .exit = cpu_cgroup_exit, |
4baf6e33 | 8091 | .base_cftypes = cpu_files, |
68318b8e SV |
8092 | .early_init = 1, |
8093 | }; | |
8094 | ||
052f1dc7 | 8095 | #endif /* CONFIG_CGROUP_SCHED */ |
d842de87 | 8096 | |
b637a328 PM |
8097 | void dump_cpu_task(int cpu) |
8098 | { | |
8099 | pr_info("Task dump for CPU %d:\n", cpu); | |
8100 | sched_show_task(cpu_curr(cpu)); | |
8101 | } |