]>
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 | 141 | delta = sched_clock_cpu(cpu_of(rq)) - rq->clock; |
4036ac15 MG |
142 | if (delta < 0) |
143 | return; | |
fe44d621 PZ |
144 | rq->clock += delta; |
145 | update_rq_clock_task(rq, delta); | |
3e51f33f PZ |
146 | } |
147 | ||
bf5c91ba IM |
148 | /* |
149 | * Debugging: various feature bits | |
150 | */ | |
f00b45c1 | 151 | |
f00b45c1 PZ |
152 | #define SCHED_FEAT(name, enabled) \ |
153 | (1UL << __SCHED_FEAT_##name) * enabled | | |
154 | ||
bf5c91ba | 155 | const_debug unsigned int sysctl_sched_features = |
391e43da | 156 | #include "features.h" |
f00b45c1 PZ |
157 | 0; |
158 | ||
159 | #undef SCHED_FEAT | |
160 | ||
161 | #ifdef CONFIG_SCHED_DEBUG | |
162 | #define SCHED_FEAT(name, enabled) \ | |
163 | #name , | |
164 | ||
1292531f | 165 | static const char * const sched_feat_names[] = { |
391e43da | 166 | #include "features.h" |
f00b45c1 PZ |
167 | }; |
168 | ||
169 | #undef SCHED_FEAT | |
170 | ||
34f3a814 | 171 | static int sched_feat_show(struct seq_file *m, void *v) |
f00b45c1 | 172 | { |
f00b45c1 PZ |
173 | int i; |
174 | ||
f8b6d1cc | 175 | for (i = 0; i < __SCHED_FEAT_NR; i++) { |
34f3a814 LZ |
176 | if (!(sysctl_sched_features & (1UL << i))) |
177 | seq_puts(m, "NO_"); | |
178 | seq_printf(m, "%s ", sched_feat_names[i]); | |
f00b45c1 | 179 | } |
34f3a814 | 180 | seq_puts(m, "\n"); |
f00b45c1 | 181 | |
34f3a814 | 182 | return 0; |
f00b45c1 PZ |
183 | } |
184 | ||
f8b6d1cc PZ |
185 | #ifdef HAVE_JUMP_LABEL |
186 | ||
c5905afb IM |
187 | #define jump_label_key__true STATIC_KEY_INIT_TRUE |
188 | #define jump_label_key__false STATIC_KEY_INIT_FALSE | |
f8b6d1cc PZ |
189 | |
190 | #define SCHED_FEAT(name, enabled) \ | |
191 | jump_label_key__##enabled , | |
192 | ||
c5905afb | 193 | struct static_key sched_feat_keys[__SCHED_FEAT_NR] = { |
f8b6d1cc PZ |
194 | #include "features.h" |
195 | }; | |
196 | ||
197 | #undef SCHED_FEAT | |
198 | ||
199 | static void sched_feat_disable(int i) | |
200 | { | |
c5905afb IM |
201 | if (static_key_enabled(&sched_feat_keys[i])) |
202 | static_key_slow_dec(&sched_feat_keys[i]); | |
f8b6d1cc PZ |
203 | } |
204 | ||
205 | static void sched_feat_enable(int i) | |
206 | { | |
c5905afb IM |
207 | if (!static_key_enabled(&sched_feat_keys[i])) |
208 | static_key_slow_inc(&sched_feat_keys[i]); | |
f8b6d1cc PZ |
209 | } |
210 | #else | |
211 | static void sched_feat_disable(int i) { }; | |
212 | static void sched_feat_enable(int i) { }; | |
213 | #endif /* HAVE_JUMP_LABEL */ | |
214 | ||
1a687c2e | 215 | static int sched_feat_set(char *cmp) |
f00b45c1 | 216 | { |
f00b45c1 | 217 | int i; |
1a687c2e | 218 | int neg = 0; |
f00b45c1 | 219 | |
524429c3 | 220 | if (strncmp(cmp, "NO_", 3) == 0) { |
f00b45c1 PZ |
221 | neg = 1; |
222 | cmp += 3; | |
223 | } | |
224 | ||
f8b6d1cc | 225 | for (i = 0; i < __SCHED_FEAT_NR; i++) { |
7740191c | 226 | if (strcmp(cmp, sched_feat_names[i]) == 0) { |
f8b6d1cc | 227 | if (neg) { |
f00b45c1 | 228 | sysctl_sched_features &= ~(1UL << i); |
f8b6d1cc PZ |
229 | sched_feat_disable(i); |
230 | } else { | |
f00b45c1 | 231 | sysctl_sched_features |= (1UL << i); |
f8b6d1cc PZ |
232 | sched_feat_enable(i); |
233 | } | |
f00b45c1 PZ |
234 | break; |
235 | } | |
236 | } | |
237 | ||
1a687c2e MG |
238 | return i; |
239 | } | |
240 | ||
241 | static ssize_t | |
242 | sched_feat_write(struct file *filp, const char __user *ubuf, | |
243 | size_t cnt, loff_t *ppos) | |
244 | { | |
245 | char buf[64]; | |
246 | char *cmp; | |
247 | int i; | |
248 | ||
249 | if (cnt > 63) | |
250 | cnt = 63; | |
251 | ||
252 | if (copy_from_user(&buf, ubuf, cnt)) | |
253 | return -EFAULT; | |
254 | ||
255 | buf[cnt] = 0; | |
256 | cmp = strstrip(buf); | |
257 | ||
258 | i = sched_feat_set(cmp); | |
f8b6d1cc | 259 | if (i == __SCHED_FEAT_NR) |
f00b45c1 PZ |
260 | return -EINVAL; |
261 | ||
42994724 | 262 | *ppos += cnt; |
f00b45c1 PZ |
263 | |
264 | return cnt; | |
265 | } | |
266 | ||
34f3a814 LZ |
267 | static int sched_feat_open(struct inode *inode, struct file *filp) |
268 | { | |
269 | return single_open(filp, sched_feat_show, NULL); | |
270 | } | |
271 | ||
828c0950 | 272 | static const struct file_operations sched_feat_fops = { |
34f3a814 LZ |
273 | .open = sched_feat_open, |
274 | .write = sched_feat_write, | |
275 | .read = seq_read, | |
276 | .llseek = seq_lseek, | |
277 | .release = single_release, | |
f00b45c1 PZ |
278 | }; |
279 | ||
280 | static __init int sched_init_debug(void) | |
281 | { | |
f00b45c1 PZ |
282 | debugfs_create_file("sched_features", 0644, NULL, NULL, |
283 | &sched_feat_fops); | |
284 | ||
285 | return 0; | |
286 | } | |
287 | late_initcall(sched_init_debug); | |
f8b6d1cc | 288 | #endif /* CONFIG_SCHED_DEBUG */ |
bf5c91ba | 289 | |
b82d9fdd PZ |
290 | /* |
291 | * Number of tasks to iterate in a single balance run. | |
292 | * Limited because this is done with IRQs disabled. | |
293 | */ | |
294 | const_debug unsigned int sysctl_sched_nr_migrate = 32; | |
295 | ||
e9e9250b PZ |
296 | /* |
297 | * period over which we average the RT time consumption, measured | |
298 | * in ms. | |
299 | * | |
300 | * default: 1s | |
301 | */ | |
302 | const_debug unsigned int sysctl_sched_time_avg = MSEC_PER_SEC; | |
303 | ||
fa85ae24 | 304 | /* |
9f0c1e56 | 305 | * period over which we measure -rt task cpu usage in us. |
fa85ae24 PZ |
306 | * default: 1s |
307 | */ | |
9f0c1e56 | 308 | unsigned int sysctl_sched_rt_period = 1000000; |
fa85ae24 | 309 | |
029632fb | 310 | __read_mostly int scheduler_running; |
6892b75e | 311 | |
9f0c1e56 PZ |
312 | /* |
313 | * part of the period that we allow rt tasks to run in us. | |
314 | * default: 0.95s | |
315 | */ | |
316 | int sysctl_sched_rt_runtime = 950000; | |
fa85ae24 | 317 | |
0970d299 | 318 | /* |
0122ec5b | 319 | * __task_rq_lock - lock the rq @p resides on. |
b29739f9 | 320 | */ |
70b97a7f | 321 | static inline struct rq *__task_rq_lock(struct task_struct *p) |
b29739f9 IM |
322 | __acquires(rq->lock) |
323 | { | |
0970d299 PZ |
324 | struct rq *rq; |
325 | ||
0122ec5b PZ |
326 | lockdep_assert_held(&p->pi_lock); |
327 | ||
3a5c359a | 328 | for (;;) { |
0970d299 | 329 | rq = task_rq(p); |
05fa785c | 330 | raw_spin_lock(&rq->lock); |
65cc8e48 | 331 | if (likely(rq == task_rq(p))) |
3a5c359a | 332 | return rq; |
05fa785c | 333 | raw_spin_unlock(&rq->lock); |
b29739f9 | 334 | } |
b29739f9 IM |
335 | } |
336 | ||
1da177e4 | 337 | /* |
0122ec5b | 338 | * task_rq_lock - lock p->pi_lock and lock the rq @p resides on. |
1da177e4 | 339 | */ |
70b97a7f | 340 | static struct rq *task_rq_lock(struct task_struct *p, unsigned long *flags) |
0122ec5b | 341 | __acquires(p->pi_lock) |
1da177e4 LT |
342 | __acquires(rq->lock) |
343 | { | |
70b97a7f | 344 | struct rq *rq; |
1da177e4 | 345 | |
3a5c359a | 346 | for (;;) { |
0122ec5b | 347 | raw_spin_lock_irqsave(&p->pi_lock, *flags); |
3a5c359a | 348 | rq = task_rq(p); |
05fa785c | 349 | raw_spin_lock(&rq->lock); |
65cc8e48 | 350 | if (likely(rq == task_rq(p))) |
3a5c359a | 351 | return rq; |
0122ec5b PZ |
352 | raw_spin_unlock(&rq->lock); |
353 | raw_spin_unlock_irqrestore(&p->pi_lock, *flags); | |
1da177e4 | 354 | } |
1da177e4 LT |
355 | } |
356 | ||
a9957449 | 357 | static void __task_rq_unlock(struct rq *rq) |
b29739f9 IM |
358 | __releases(rq->lock) |
359 | { | |
05fa785c | 360 | raw_spin_unlock(&rq->lock); |
b29739f9 IM |
361 | } |
362 | ||
0122ec5b PZ |
363 | static inline void |
364 | task_rq_unlock(struct rq *rq, struct task_struct *p, unsigned long *flags) | |
1da177e4 | 365 | __releases(rq->lock) |
0122ec5b | 366 | __releases(p->pi_lock) |
1da177e4 | 367 | { |
0122ec5b PZ |
368 | raw_spin_unlock(&rq->lock); |
369 | raw_spin_unlock_irqrestore(&p->pi_lock, *flags); | |
1da177e4 LT |
370 | } |
371 | ||
1da177e4 | 372 | /* |
cc2a73b5 | 373 | * this_rq_lock - lock this runqueue and disable interrupts. |
1da177e4 | 374 | */ |
a9957449 | 375 | static struct rq *this_rq_lock(void) |
1da177e4 LT |
376 | __acquires(rq->lock) |
377 | { | |
70b97a7f | 378 | struct rq *rq; |
1da177e4 LT |
379 | |
380 | local_irq_disable(); | |
381 | rq = this_rq(); | |
05fa785c | 382 | raw_spin_lock(&rq->lock); |
1da177e4 LT |
383 | |
384 | return rq; | |
385 | } | |
386 | ||
8f4d37ec PZ |
387 | #ifdef CONFIG_SCHED_HRTICK |
388 | /* | |
389 | * Use HR-timers to deliver accurate preemption points. | |
8f4d37ec | 390 | */ |
8f4d37ec | 391 | |
8f4d37ec PZ |
392 | static void hrtick_clear(struct rq *rq) |
393 | { | |
394 | if (hrtimer_active(&rq->hrtick_timer)) | |
395 | hrtimer_cancel(&rq->hrtick_timer); | |
396 | } | |
397 | ||
8f4d37ec PZ |
398 | /* |
399 | * High-resolution timer tick. | |
400 | * Runs from hardirq context with interrupts disabled. | |
401 | */ | |
402 | static enum hrtimer_restart hrtick(struct hrtimer *timer) | |
403 | { | |
404 | struct rq *rq = container_of(timer, struct rq, hrtick_timer); | |
405 | ||
406 | WARN_ON_ONCE(cpu_of(rq) != smp_processor_id()); | |
407 | ||
05fa785c | 408 | raw_spin_lock(&rq->lock); |
3e51f33f | 409 | update_rq_clock(rq); |
8f4d37ec | 410 | rq->curr->sched_class->task_tick(rq, rq->curr, 1); |
05fa785c | 411 | raw_spin_unlock(&rq->lock); |
8f4d37ec PZ |
412 | |
413 | return HRTIMER_NORESTART; | |
414 | } | |
415 | ||
95e904c7 | 416 | #ifdef CONFIG_SMP |
971ee28c PZ |
417 | |
418 | static int __hrtick_restart(struct rq *rq) | |
419 | { | |
420 | struct hrtimer *timer = &rq->hrtick_timer; | |
421 | ktime_t time = hrtimer_get_softexpires(timer); | |
422 | ||
423 | return __hrtimer_start_range_ns(timer, time, 0, HRTIMER_MODE_ABS_PINNED, 0); | |
424 | } | |
425 | ||
31656519 PZ |
426 | /* |
427 | * called from hardirq (IPI) context | |
428 | */ | |
429 | static void __hrtick_start(void *arg) | |
b328ca18 | 430 | { |
31656519 | 431 | struct rq *rq = arg; |
b328ca18 | 432 | |
05fa785c | 433 | raw_spin_lock(&rq->lock); |
971ee28c | 434 | __hrtick_restart(rq); |
31656519 | 435 | rq->hrtick_csd_pending = 0; |
05fa785c | 436 | raw_spin_unlock(&rq->lock); |
b328ca18 PZ |
437 | } |
438 | ||
31656519 PZ |
439 | /* |
440 | * Called to set the hrtick timer state. | |
441 | * | |
442 | * called with rq->lock held and irqs disabled | |
443 | */ | |
029632fb | 444 | void hrtick_start(struct rq *rq, u64 delay) |
b328ca18 | 445 | { |
31656519 PZ |
446 | struct hrtimer *timer = &rq->hrtick_timer; |
447 | ktime_t time = ktime_add_ns(timer->base->get_time(), delay); | |
b328ca18 | 448 | |
cc584b21 | 449 | hrtimer_set_expires(timer, time); |
31656519 PZ |
450 | |
451 | if (rq == this_rq()) { | |
971ee28c | 452 | __hrtick_restart(rq); |
31656519 | 453 | } else if (!rq->hrtick_csd_pending) { |
c46fff2a | 454 | smp_call_function_single_async(cpu_of(rq), &rq->hrtick_csd); |
31656519 PZ |
455 | rq->hrtick_csd_pending = 1; |
456 | } | |
b328ca18 PZ |
457 | } |
458 | ||
459 | static int | |
460 | hotplug_hrtick(struct notifier_block *nfb, unsigned long action, void *hcpu) | |
461 | { | |
462 | int cpu = (int)(long)hcpu; | |
463 | ||
464 | switch (action) { | |
465 | case CPU_UP_CANCELED: | |
466 | case CPU_UP_CANCELED_FROZEN: | |
467 | case CPU_DOWN_PREPARE: | |
468 | case CPU_DOWN_PREPARE_FROZEN: | |
469 | case CPU_DEAD: | |
470 | case CPU_DEAD_FROZEN: | |
31656519 | 471 | hrtick_clear(cpu_rq(cpu)); |
b328ca18 PZ |
472 | return NOTIFY_OK; |
473 | } | |
474 | ||
475 | return NOTIFY_DONE; | |
476 | } | |
477 | ||
fa748203 | 478 | static __init void init_hrtick(void) |
b328ca18 PZ |
479 | { |
480 | hotcpu_notifier(hotplug_hrtick, 0); | |
481 | } | |
31656519 PZ |
482 | #else |
483 | /* | |
484 | * Called to set the hrtick timer state. | |
485 | * | |
486 | * called with rq->lock held and irqs disabled | |
487 | */ | |
029632fb | 488 | void hrtick_start(struct rq *rq, u64 delay) |
31656519 | 489 | { |
7f1e2ca9 | 490 | __hrtimer_start_range_ns(&rq->hrtick_timer, ns_to_ktime(delay), 0, |
5c333864 | 491 | HRTIMER_MODE_REL_PINNED, 0); |
31656519 | 492 | } |
b328ca18 | 493 | |
006c75f1 | 494 | static inline void init_hrtick(void) |
8f4d37ec | 495 | { |
8f4d37ec | 496 | } |
31656519 | 497 | #endif /* CONFIG_SMP */ |
8f4d37ec | 498 | |
31656519 | 499 | static void init_rq_hrtick(struct rq *rq) |
8f4d37ec | 500 | { |
31656519 PZ |
501 | #ifdef CONFIG_SMP |
502 | rq->hrtick_csd_pending = 0; | |
8f4d37ec | 503 | |
31656519 PZ |
504 | rq->hrtick_csd.flags = 0; |
505 | rq->hrtick_csd.func = __hrtick_start; | |
506 | rq->hrtick_csd.info = rq; | |
507 | #endif | |
8f4d37ec | 508 | |
31656519 PZ |
509 | hrtimer_init(&rq->hrtick_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); |
510 | rq->hrtick_timer.function = hrtick; | |
8f4d37ec | 511 | } |
006c75f1 | 512 | #else /* CONFIG_SCHED_HRTICK */ |
8f4d37ec PZ |
513 | static inline void hrtick_clear(struct rq *rq) |
514 | { | |
515 | } | |
516 | ||
8f4d37ec PZ |
517 | static inline void init_rq_hrtick(struct rq *rq) |
518 | { | |
519 | } | |
520 | ||
b328ca18 PZ |
521 | static inline void init_hrtick(void) |
522 | { | |
523 | } | |
006c75f1 | 524 | #endif /* CONFIG_SCHED_HRTICK */ |
8f4d37ec | 525 | |
fd99f91a PZ |
526 | /* |
527 | * cmpxchg based fetch_or, macro so it works for different integer types | |
528 | */ | |
529 | #define fetch_or(ptr, val) \ | |
530 | ({ typeof(*(ptr)) __old, __val = *(ptr); \ | |
531 | for (;;) { \ | |
532 | __old = cmpxchg((ptr), __val, __val | (val)); \ | |
533 | if (__old == __val) \ | |
534 | break; \ | |
535 | __val = __old; \ | |
536 | } \ | |
537 | __old; \ | |
538 | }) | |
539 | ||
e3baac47 | 540 | #if defined(CONFIG_SMP) && defined(TIF_POLLING_NRFLAG) |
fd99f91a PZ |
541 | /* |
542 | * Atomically set TIF_NEED_RESCHED and test for TIF_POLLING_NRFLAG, | |
543 | * this avoids any races wrt polling state changes and thereby avoids | |
544 | * spurious IPIs. | |
545 | */ | |
546 | static bool set_nr_and_not_polling(struct task_struct *p) | |
547 | { | |
548 | struct thread_info *ti = task_thread_info(p); | |
549 | return !(fetch_or(&ti->flags, _TIF_NEED_RESCHED) & _TIF_POLLING_NRFLAG); | |
550 | } | |
e3baac47 PZ |
551 | |
552 | /* | |
553 | * Atomically set TIF_NEED_RESCHED if TIF_POLLING_NRFLAG is set. | |
554 | * | |
555 | * If this returns true, then the idle task promises to call | |
556 | * sched_ttwu_pending() and reschedule soon. | |
557 | */ | |
558 | static bool set_nr_if_polling(struct task_struct *p) | |
559 | { | |
560 | struct thread_info *ti = task_thread_info(p); | |
561 | typeof(ti->flags) old, val = ACCESS_ONCE(ti->flags); | |
562 | ||
563 | for (;;) { | |
564 | if (!(val & _TIF_POLLING_NRFLAG)) | |
565 | return false; | |
566 | if (val & _TIF_NEED_RESCHED) | |
567 | return true; | |
568 | old = cmpxchg(&ti->flags, val, val | _TIF_NEED_RESCHED); | |
569 | if (old == val) | |
570 | break; | |
571 | val = old; | |
572 | } | |
573 | return true; | |
574 | } | |
575 | ||
fd99f91a PZ |
576 | #else |
577 | static bool set_nr_and_not_polling(struct task_struct *p) | |
578 | { | |
579 | set_tsk_need_resched(p); | |
580 | return true; | |
581 | } | |
e3baac47 PZ |
582 | |
583 | #ifdef CONFIG_SMP | |
584 | static bool set_nr_if_polling(struct task_struct *p) | |
585 | { | |
586 | return false; | |
587 | } | |
588 | #endif | |
fd99f91a PZ |
589 | #endif |
590 | ||
c24d20db IM |
591 | /* |
592 | * resched_task - mark a task 'to be rescheduled now'. | |
593 | * | |
594 | * On UP this means the setting of the need_resched flag, on SMP it | |
595 | * might also involve a cross-CPU call to trigger the scheduler on | |
596 | * the target CPU. | |
597 | */ | |
029632fb | 598 | void resched_task(struct task_struct *p) |
c24d20db IM |
599 | { |
600 | int cpu; | |
601 | ||
b021fe3e | 602 | lockdep_assert_held(&task_rq(p)->lock); |
c24d20db | 603 | |
5ed0cec0 | 604 | if (test_tsk_need_resched(p)) |
c24d20db IM |
605 | return; |
606 | ||
c24d20db | 607 | cpu = task_cpu(p); |
fd99f91a | 608 | |
f27dde8d | 609 | if (cpu == smp_processor_id()) { |
fd99f91a | 610 | set_tsk_need_resched(p); |
f27dde8d | 611 | set_preempt_need_resched(); |
c24d20db | 612 | return; |
f27dde8d | 613 | } |
c24d20db | 614 | |
fd99f91a | 615 | if (set_nr_and_not_polling(p)) |
c24d20db | 616 | smp_send_reschedule(cpu); |
dfc68f29 AL |
617 | else |
618 | trace_sched_wake_idle_without_ipi(cpu); | |
c24d20db IM |
619 | } |
620 | ||
029632fb | 621 | void resched_cpu(int cpu) |
c24d20db IM |
622 | { |
623 | struct rq *rq = cpu_rq(cpu); | |
624 | unsigned long flags; | |
625 | ||
05fa785c | 626 | if (!raw_spin_trylock_irqsave(&rq->lock, flags)) |
c24d20db IM |
627 | return; |
628 | resched_task(cpu_curr(cpu)); | |
05fa785c | 629 | raw_spin_unlock_irqrestore(&rq->lock, flags); |
c24d20db | 630 | } |
06d8308c | 631 | |
b021fe3e | 632 | #ifdef CONFIG_SMP |
3451d024 | 633 | #ifdef CONFIG_NO_HZ_COMMON |
83cd4fe2 VP |
634 | /* |
635 | * In the semi idle case, use the nearest busy cpu for migrating timers | |
636 | * from an idle cpu. This is good for power-savings. | |
637 | * | |
638 | * We don't do similar optimization for completely idle system, as | |
639 | * selecting an idle cpu will add more delays to the timers than intended | |
640 | * (as that cpu's timer base may not be uptodate wrt jiffies etc). | |
641 | */ | |
6201b4d6 | 642 | int get_nohz_timer_target(int pinned) |
83cd4fe2 VP |
643 | { |
644 | int cpu = smp_processor_id(); | |
645 | int i; | |
646 | struct sched_domain *sd; | |
647 | ||
6201b4d6 VK |
648 | if (pinned || !get_sysctl_timer_migration() || !idle_cpu(cpu)) |
649 | return cpu; | |
650 | ||
057f3fad | 651 | rcu_read_lock(); |
83cd4fe2 | 652 | for_each_domain(cpu, sd) { |
057f3fad PZ |
653 | for_each_cpu(i, sched_domain_span(sd)) { |
654 | if (!idle_cpu(i)) { | |
655 | cpu = i; | |
656 | goto unlock; | |
657 | } | |
658 | } | |
83cd4fe2 | 659 | } |
057f3fad PZ |
660 | unlock: |
661 | rcu_read_unlock(); | |
83cd4fe2 VP |
662 | return cpu; |
663 | } | |
06d8308c TG |
664 | /* |
665 | * When add_timer_on() enqueues a timer into the timer wheel of an | |
666 | * idle CPU then this timer might expire before the next timer event | |
667 | * which is scheduled to wake up that CPU. In case of a completely | |
668 | * idle system the next event might even be infinite time into the | |
669 | * future. wake_up_idle_cpu() ensures that the CPU is woken up and | |
670 | * leaves the inner idle loop so the newly added timer is taken into | |
671 | * account when the CPU goes back to idle and evaluates the timer | |
672 | * wheel for the next timer event. | |
673 | */ | |
1c20091e | 674 | static void wake_up_idle_cpu(int cpu) |
06d8308c TG |
675 | { |
676 | struct rq *rq = cpu_rq(cpu); | |
677 | ||
678 | if (cpu == smp_processor_id()) | |
679 | return; | |
680 | ||
67b9ca70 | 681 | if (set_nr_and_not_polling(rq->idle)) |
06d8308c | 682 | smp_send_reschedule(cpu); |
dfc68f29 AL |
683 | else |
684 | trace_sched_wake_idle_without_ipi(cpu); | |
45bf76df IM |
685 | } |
686 | ||
c5bfece2 | 687 | static bool wake_up_full_nohz_cpu(int cpu) |
1c20091e | 688 | { |
53c5fa16 FW |
689 | /* |
690 | * We just need the target to call irq_exit() and re-evaluate | |
691 | * the next tick. The nohz full kick at least implies that. | |
692 | * If needed we can still optimize that later with an | |
693 | * empty IRQ. | |
694 | */ | |
c5bfece2 | 695 | if (tick_nohz_full_cpu(cpu)) { |
1c20091e FW |
696 | if (cpu != smp_processor_id() || |
697 | tick_nohz_tick_stopped()) | |
53c5fa16 | 698 | tick_nohz_full_kick_cpu(cpu); |
1c20091e FW |
699 | return true; |
700 | } | |
701 | ||
702 | return false; | |
703 | } | |
704 | ||
705 | void wake_up_nohz_cpu(int cpu) | |
706 | { | |
c5bfece2 | 707 | if (!wake_up_full_nohz_cpu(cpu)) |
1c20091e FW |
708 | wake_up_idle_cpu(cpu); |
709 | } | |
710 | ||
ca38062e | 711 | static inline bool got_nohz_idle_kick(void) |
45bf76df | 712 | { |
1c792db7 | 713 | int cpu = smp_processor_id(); |
873b4c65 VG |
714 | |
715 | if (!test_bit(NOHZ_BALANCE_KICK, nohz_flags(cpu))) | |
716 | return false; | |
717 | ||
718 | if (idle_cpu(cpu) && !need_resched()) | |
719 | return true; | |
720 | ||
721 | /* | |
722 | * We can't run Idle Load Balance on this CPU for this time so we | |
723 | * cancel it and clear NOHZ_BALANCE_KICK | |
724 | */ | |
725 | clear_bit(NOHZ_BALANCE_KICK, nohz_flags(cpu)); | |
726 | return false; | |
45bf76df IM |
727 | } |
728 | ||
3451d024 | 729 | #else /* CONFIG_NO_HZ_COMMON */ |
45bf76df | 730 | |
ca38062e | 731 | static inline bool got_nohz_idle_kick(void) |
2069dd75 | 732 | { |
ca38062e | 733 | return false; |
2069dd75 PZ |
734 | } |
735 | ||
3451d024 | 736 | #endif /* CONFIG_NO_HZ_COMMON */ |
d842de87 | 737 | |
ce831b38 FW |
738 | #ifdef CONFIG_NO_HZ_FULL |
739 | bool sched_can_stop_tick(void) | |
740 | { | |
3882ec64 FW |
741 | /* |
742 | * More than one running task need preemption. | |
743 | * nr_running update is assumed to be visible | |
744 | * after IPI is sent from wakers. | |
745 | */ | |
541b8264 VK |
746 | if (this_rq()->nr_running > 1) |
747 | return false; | |
ce831b38 | 748 | |
541b8264 | 749 | return true; |
ce831b38 FW |
750 | } |
751 | #endif /* CONFIG_NO_HZ_FULL */ | |
d842de87 | 752 | |
029632fb | 753 | void sched_avg_update(struct rq *rq) |
18d95a28 | 754 | { |
e9e9250b PZ |
755 | s64 period = sched_avg_period(); |
756 | ||
78becc27 | 757 | while ((s64)(rq_clock(rq) - rq->age_stamp) > period) { |
0d98bb26 WD |
758 | /* |
759 | * Inline assembly required to prevent the compiler | |
760 | * optimising this loop into a divmod call. | |
761 | * See __iter_div_u64_rem() for another example of this. | |
762 | */ | |
763 | asm("" : "+rm" (rq->age_stamp)); | |
e9e9250b PZ |
764 | rq->age_stamp += period; |
765 | rq->rt_avg /= 2; | |
766 | } | |
18d95a28 PZ |
767 | } |
768 | ||
6d6bc0ad | 769 | #endif /* CONFIG_SMP */ |
18d95a28 | 770 | |
a790de99 PT |
771 | #if defined(CONFIG_RT_GROUP_SCHED) || (defined(CONFIG_FAIR_GROUP_SCHED) && \ |
772 | (defined(CONFIG_SMP) || defined(CONFIG_CFS_BANDWIDTH))) | |
c09595f6 | 773 | /* |
8277434e PT |
774 | * Iterate task_group tree rooted at *from, calling @down when first entering a |
775 | * node and @up when leaving it for the final time. | |
776 | * | |
777 | * Caller must hold rcu_lock or sufficient equivalent. | |
c09595f6 | 778 | */ |
029632fb | 779 | int walk_tg_tree_from(struct task_group *from, |
8277434e | 780 | tg_visitor down, tg_visitor up, void *data) |
c09595f6 PZ |
781 | { |
782 | struct task_group *parent, *child; | |
eb755805 | 783 | int ret; |
c09595f6 | 784 | |
8277434e PT |
785 | parent = from; |
786 | ||
c09595f6 | 787 | down: |
eb755805 PZ |
788 | ret = (*down)(parent, data); |
789 | if (ret) | |
8277434e | 790 | goto out; |
c09595f6 PZ |
791 | list_for_each_entry_rcu(child, &parent->children, siblings) { |
792 | parent = child; | |
793 | goto down; | |
794 | ||
795 | up: | |
796 | continue; | |
797 | } | |
eb755805 | 798 | ret = (*up)(parent, data); |
8277434e PT |
799 | if (ret || parent == from) |
800 | goto out; | |
c09595f6 PZ |
801 | |
802 | child = parent; | |
803 | parent = parent->parent; | |
804 | if (parent) | |
805 | goto up; | |
8277434e | 806 | out: |
eb755805 | 807 | return ret; |
c09595f6 PZ |
808 | } |
809 | ||
029632fb | 810 | int tg_nop(struct task_group *tg, void *data) |
eb755805 | 811 | { |
e2b245f8 | 812 | return 0; |
eb755805 | 813 | } |
18d95a28 PZ |
814 | #endif |
815 | ||
45bf76df IM |
816 | static void set_load_weight(struct task_struct *p) |
817 | { | |
f05998d4 NR |
818 | int prio = p->static_prio - MAX_RT_PRIO; |
819 | struct load_weight *load = &p->se.load; | |
820 | ||
dd41f596 IM |
821 | /* |
822 | * SCHED_IDLE tasks get minimal weight: | |
823 | */ | |
824 | if (p->policy == SCHED_IDLE) { | |
c8b28116 | 825 | load->weight = scale_load(WEIGHT_IDLEPRIO); |
f05998d4 | 826 | load->inv_weight = WMULT_IDLEPRIO; |
dd41f596 IM |
827 | return; |
828 | } | |
71f8bd46 | 829 | |
c8b28116 | 830 | load->weight = scale_load(prio_to_weight[prio]); |
f05998d4 | 831 | load->inv_weight = prio_to_wmult[prio]; |
71f8bd46 IM |
832 | } |
833 | ||
371fd7e7 | 834 | static void enqueue_task(struct rq *rq, struct task_struct *p, int flags) |
2087a1ad | 835 | { |
a64692a3 | 836 | update_rq_clock(rq); |
43148951 | 837 | sched_info_queued(rq, p); |
371fd7e7 | 838 | p->sched_class->enqueue_task(rq, p, flags); |
71f8bd46 IM |
839 | } |
840 | ||
371fd7e7 | 841 | static void dequeue_task(struct rq *rq, struct task_struct *p, int flags) |
71f8bd46 | 842 | { |
a64692a3 | 843 | update_rq_clock(rq); |
43148951 | 844 | sched_info_dequeued(rq, p); |
371fd7e7 | 845 | p->sched_class->dequeue_task(rq, p, flags); |
71f8bd46 IM |
846 | } |
847 | ||
029632fb | 848 | void activate_task(struct rq *rq, struct task_struct *p, int flags) |
1e3c88bd PZ |
849 | { |
850 | if (task_contributes_to_load(p)) | |
851 | rq->nr_uninterruptible--; | |
852 | ||
371fd7e7 | 853 | enqueue_task(rq, p, flags); |
1e3c88bd PZ |
854 | } |
855 | ||
029632fb | 856 | void deactivate_task(struct rq *rq, struct task_struct *p, int flags) |
1e3c88bd PZ |
857 | { |
858 | if (task_contributes_to_load(p)) | |
859 | rq->nr_uninterruptible++; | |
860 | ||
371fd7e7 | 861 | dequeue_task(rq, p, flags); |
1e3c88bd PZ |
862 | } |
863 | ||
fe44d621 | 864 | static void update_rq_clock_task(struct rq *rq, s64 delta) |
aa483808 | 865 | { |
095c0aa8 GC |
866 | /* |
867 | * In theory, the compile should just see 0 here, and optimize out the call | |
868 | * to sched_rt_avg_update. But I don't trust it... | |
869 | */ | |
870 | #if defined(CONFIG_IRQ_TIME_ACCOUNTING) || defined(CONFIG_PARAVIRT_TIME_ACCOUNTING) | |
871 | s64 steal = 0, irq_delta = 0; | |
872 | #endif | |
873 | #ifdef CONFIG_IRQ_TIME_ACCOUNTING | |
8e92c201 | 874 | irq_delta = irq_time_read(cpu_of(rq)) - rq->prev_irq_time; |
fe44d621 PZ |
875 | |
876 | /* | |
877 | * Since irq_time is only updated on {soft,}irq_exit, we might run into | |
878 | * this case when a previous update_rq_clock() happened inside a | |
879 | * {soft,}irq region. | |
880 | * | |
881 | * When this happens, we stop ->clock_task and only update the | |
882 | * prev_irq_time stamp to account for the part that fit, so that a next | |
883 | * update will consume the rest. This ensures ->clock_task is | |
884 | * monotonic. | |
885 | * | |
886 | * It does however cause some slight miss-attribution of {soft,}irq | |
887 | * time, a more accurate solution would be to update the irq_time using | |
888 | * the current rq->clock timestamp, except that would require using | |
889 | * atomic ops. | |
890 | */ | |
891 | if (irq_delta > delta) | |
892 | irq_delta = delta; | |
893 | ||
894 | rq->prev_irq_time += irq_delta; | |
895 | delta -= irq_delta; | |
095c0aa8 GC |
896 | #endif |
897 | #ifdef CONFIG_PARAVIRT_TIME_ACCOUNTING | |
c5905afb | 898 | if (static_key_false((¶virt_steal_rq_enabled))) { |
095c0aa8 GC |
899 | steal = paravirt_steal_clock(cpu_of(rq)); |
900 | steal -= rq->prev_steal_time_rq; | |
901 | ||
902 | if (unlikely(steal > delta)) | |
903 | steal = delta; | |
904 | ||
095c0aa8 | 905 | rq->prev_steal_time_rq += steal; |
095c0aa8 GC |
906 | delta -= steal; |
907 | } | |
908 | #endif | |
909 | ||
fe44d621 PZ |
910 | rq->clock_task += delta; |
911 | ||
095c0aa8 | 912 | #if defined(CONFIG_IRQ_TIME_ACCOUNTING) || defined(CONFIG_PARAVIRT_TIME_ACCOUNTING) |
5d4dfddd | 913 | if ((irq_delta + steal) && sched_feat(NONTASK_CAPACITY)) |
095c0aa8 GC |
914 | sched_rt_avg_update(rq, irq_delta + steal); |
915 | #endif | |
aa483808 VP |
916 | } |
917 | ||
34f971f6 PZ |
918 | void sched_set_stop_task(int cpu, struct task_struct *stop) |
919 | { | |
920 | struct sched_param param = { .sched_priority = MAX_RT_PRIO - 1 }; | |
921 | struct task_struct *old_stop = cpu_rq(cpu)->stop; | |
922 | ||
923 | if (stop) { | |
924 | /* | |
925 | * Make it appear like a SCHED_FIFO task, its something | |
926 | * userspace knows about and won't get confused about. | |
927 | * | |
928 | * Also, it will make PI more or less work without too | |
929 | * much confusion -- but then, stop work should not | |
930 | * rely on PI working anyway. | |
931 | */ | |
932 | sched_setscheduler_nocheck(stop, SCHED_FIFO, ¶m); | |
933 | ||
934 | stop->sched_class = &stop_sched_class; | |
935 | } | |
936 | ||
937 | cpu_rq(cpu)->stop = stop; | |
938 | ||
939 | if (old_stop) { | |
940 | /* | |
941 | * Reset it back to a normal scheduling class so that | |
942 | * it can die in pieces. | |
943 | */ | |
944 | old_stop->sched_class = &rt_sched_class; | |
945 | } | |
946 | } | |
947 | ||
14531189 | 948 | /* |
dd41f596 | 949 | * __normal_prio - return the priority that is based on the static prio |
14531189 | 950 | */ |
14531189 IM |
951 | static inline int __normal_prio(struct task_struct *p) |
952 | { | |
dd41f596 | 953 | return p->static_prio; |
14531189 IM |
954 | } |
955 | ||
b29739f9 IM |
956 | /* |
957 | * Calculate the expected normal priority: i.e. priority | |
958 | * without taking RT-inheritance into account. Might be | |
959 | * boosted by interactivity modifiers. Changes upon fork, | |
960 | * setprio syscalls, and whenever the interactivity | |
961 | * estimator recalculates. | |
962 | */ | |
36c8b586 | 963 | static inline int normal_prio(struct task_struct *p) |
b29739f9 IM |
964 | { |
965 | int prio; | |
966 | ||
aab03e05 DF |
967 | if (task_has_dl_policy(p)) |
968 | prio = MAX_DL_PRIO-1; | |
969 | else if (task_has_rt_policy(p)) | |
b29739f9 IM |
970 | prio = MAX_RT_PRIO-1 - p->rt_priority; |
971 | else | |
972 | prio = __normal_prio(p); | |
973 | return prio; | |
974 | } | |
975 | ||
976 | /* | |
977 | * Calculate the current priority, i.e. the priority | |
978 | * taken into account by the scheduler. This value might | |
979 | * be boosted by RT tasks, or might be boosted by | |
980 | * interactivity modifiers. Will be RT if the task got | |
981 | * RT-boosted. If not then it returns p->normal_prio. | |
982 | */ | |
36c8b586 | 983 | static int effective_prio(struct task_struct *p) |
b29739f9 IM |
984 | { |
985 | p->normal_prio = normal_prio(p); | |
986 | /* | |
987 | * If we are RT tasks or we were boosted to RT priority, | |
988 | * keep the priority unchanged. Otherwise, update priority | |
989 | * to the normal priority: | |
990 | */ | |
991 | if (!rt_prio(p->prio)) | |
992 | return p->normal_prio; | |
993 | return p->prio; | |
994 | } | |
995 | ||
1da177e4 LT |
996 | /** |
997 | * task_curr - is this task currently executing on a CPU? | |
998 | * @p: the task in question. | |
e69f6186 YB |
999 | * |
1000 | * Return: 1 if the task is currently executing. 0 otherwise. | |
1da177e4 | 1001 | */ |
36c8b586 | 1002 | inline int task_curr(const struct task_struct *p) |
1da177e4 LT |
1003 | { |
1004 | return cpu_curr(task_cpu(p)) == p; | |
1005 | } | |
1006 | ||
cb469845 SR |
1007 | static inline void check_class_changed(struct rq *rq, struct task_struct *p, |
1008 | const struct sched_class *prev_class, | |
da7a735e | 1009 | int oldprio) |
cb469845 SR |
1010 | { |
1011 | if (prev_class != p->sched_class) { | |
1012 | if (prev_class->switched_from) | |
da7a735e PZ |
1013 | prev_class->switched_from(rq, p); |
1014 | p->sched_class->switched_to(rq, p); | |
2d3d891d | 1015 | } else if (oldprio != p->prio || dl_task(p)) |
da7a735e | 1016 | p->sched_class->prio_changed(rq, p, oldprio); |
cb469845 SR |
1017 | } |
1018 | ||
029632fb | 1019 | void check_preempt_curr(struct rq *rq, struct task_struct *p, int flags) |
1e5a7405 PZ |
1020 | { |
1021 | const struct sched_class *class; | |
1022 | ||
1023 | if (p->sched_class == rq->curr->sched_class) { | |
1024 | rq->curr->sched_class->check_preempt_curr(rq, p, flags); | |
1025 | } else { | |
1026 | for_each_class(class) { | |
1027 | if (class == rq->curr->sched_class) | |
1028 | break; | |
1029 | if (class == p->sched_class) { | |
1030 | resched_task(rq->curr); | |
1031 | break; | |
1032 | } | |
1033 | } | |
1034 | } | |
1035 | ||
1036 | /* | |
1037 | * A queue event has occurred, and we're going to schedule. In | |
1038 | * this case, we can save a useless back to back clock update. | |
1039 | */ | |
fd2f4419 | 1040 | if (rq->curr->on_rq && test_tsk_need_resched(rq->curr)) |
1e5a7405 PZ |
1041 | rq->skip_clock_update = 1; |
1042 | } | |
1043 | ||
1da177e4 | 1044 | #ifdef CONFIG_SMP |
dd41f596 | 1045 | void set_task_cpu(struct task_struct *p, unsigned int new_cpu) |
c65cc870 | 1046 | { |
e2912009 PZ |
1047 | #ifdef CONFIG_SCHED_DEBUG |
1048 | /* | |
1049 | * We should never call set_task_cpu() on a blocked task, | |
1050 | * ttwu() will sort out the placement. | |
1051 | */ | |
077614ee | 1052 | WARN_ON_ONCE(p->state != TASK_RUNNING && p->state != TASK_WAKING && |
01028747 | 1053 | !(task_preempt_count(p) & PREEMPT_ACTIVE)); |
0122ec5b PZ |
1054 | |
1055 | #ifdef CONFIG_LOCKDEP | |
6c6c54e1 PZ |
1056 | /* |
1057 | * The caller should hold either p->pi_lock or rq->lock, when changing | |
1058 | * a task's CPU. ->pi_lock for waking tasks, rq->lock for runnable tasks. | |
1059 | * | |
1060 | * sched_move_task() holds both and thus holding either pins the cgroup, | |
8323f26c | 1061 | * see task_group(). |
6c6c54e1 PZ |
1062 | * |
1063 | * Furthermore, all task_rq users should acquire both locks, see | |
1064 | * task_rq_lock(). | |
1065 | */ | |
0122ec5b PZ |
1066 | WARN_ON_ONCE(debug_locks && !(lockdep_is_held(&p->pi_lock) || |
1067 | lockdep_is_held(&task_rq(p)->lock))); | |
1068 | #endif | |
e2912009 PZ |
1069 | #endif |
1070 | ||
de1d7286 | 1071 | trace_sched_migrate_task(p, new_cpu); |
cbc34ed1 | 1072 | |
0c69774e | 1073 | if (task_cpu(p) != new_cpu) { |
0a74bef8 PT |
1074 | if (p->sched_class->migrate_task_rq) |
1075 | p->sched_class->migrate_task_rq(p, new_cpu); | |
0c69774e | 1076 | p->se.nr_migrations++; |
a8b0ca17 | 1077 | perf_sw_event(PERF_COUNT_SW_CPU_MIGRATIONS, 1, NULL, 0); |
0c69774e | 1078 | } |
dd41f596 IM |
1079 | |
1080 | __set_task_cpu(p, new_cpu); | |
c65cc870 IM |
1081 | } |
1082 | ||
ac66f547 PZ |
1083 | static void __migrate_swap_task(struct task_struct *p, int cpu) |
1084 | { | |
1085 | if (p->on_rq) { | |
1086 | struct rq *src_rq, *dst_rq; | |
1087 | ||
1088 | src_rq = task_rq(p); | |
1089 | dst_rq = cpu_rq(cpu); | |
1090 | ||
1091 | deactivate_task(src_rq, p, 0); | |
1092 | set_task_cpu(p, cpu); | |
1093 | activate_task(dst_rq, p, 0); | |
1094 | check_preempt_curr(dst_rq, p, 0); | |
1095 | } else { | |
1096 | /* | |
1097 | * Task isn't running anymore; make it appear like we migrated | |
1098 | * it before it went to sleep. This means on wakeup we make the | |
1099 | * previous cpu our targer instead of where it really is. | |
1100 | */ | |
1101 | p->wake_cpu = cpu; | |
1102 | } | |
1103 | } | |
1104 | ||
1105 | struct migration_swap_arg { | |
1106 | struct task_struct *src_task, *dst_task; | |
1107 | int src_cpu, dst_cpu; | |
1108 | }; | |
1109 | ||
1110 | static int migrate_swap_stop(void *data) | |
1111 | { | |
1112 | struct migration_swap_arg *arg = data; | |
1113 | struct rq *src_rq, *dst_rq; | |
1114 | int ret = -EAGAIN; | |
1115 | ||
1116 | src_rq = cpu_rq(arg->src_cpu); | |
1117 | dst_rq = cpu_rq(arg->dst_cpu); | |
1118 | ||
74602315 PZ |
1119 | double_raw_lock(&arg->src_task->pi_lock, |
1120 | &arg->dst_task->pi_lock); | |
ac66f547 PZ |
1121 | double_rq_lock(src_rq, dst_rq); |
1122 | if (task_cpu(arg->dst_task) != arg->dst_cpu) | |
1123 | goto unlock; | |
1124 | ||
1125 | if (task_cpu(arg->src_task) != arg->src_cpu) | |
1126 | goto unlock; | |
1127 | ||
1128 | if (!cpumask_test_cpu(arg->dst_cpu, tsk_cpus_allowed(arg->src_task))) | |
1129 | goto unlock; | |
1130 | ||
1131 | if (!cpumask_test_cpu(arg->src_cpu, tsk_cpus_allowed(arg->dst_task))) | |
1132 | goto unlock; | |
1133 | ||
1134 | __migrate_swap_task(arg->src_task, arg->dst_cpu); | |
1135 | __migrate_swap_task(arg->dst_task, arg->src_cpu); | |
1136 | ||
1137 | ret = 0; | |
1138 | ||
1139 | unlock: | |
1140 | double_rq_unlock(src_rq, dst_rq); | |
74602315 PZ |
1141 | raw_spin_unlock(&arg->dst_task->pi_lock); |
1142 | raw_spin_unlock(&arg->src_task->pi_lock); | |
ac66f547 PZ |
1143 | |
1144 | return ret; | |
1145 | } | |
1146 | ||
1147 | /* | |
1148 | * Cross migrate two tasks | |
1149 | */ | |
1150 | int migrate_swap(struct task_struct *cur, struct task_struct *p) | |
1151 | { | |
1152 | struct migration_swap_arg arg; | |
1153 | int ret = -EINVAL; | |
1154 | ||
ac66f547 PZ |
1155 | arg = (struct migration_swap_arg){ |
1156 | .src_task = cur, | |
1157 | .src_cpu = task_cpu(cur), | |
1158 | .dst_task = p, | |
1159 | .dst_cpu = task_cpu(p), | |
1160 | }; | |
1161 | ||
1162 | if (arg.src_cpu == arg.dst_cpu) | |
1163 | goto out; | |
1164 | ||
6acce3ef PZ |
1165 | /* |
1166 | * These three tests are all lockless; this is OK since all of them | |
1167 | * will be re-checked with proper locks held further down the line. | |
1168 | */ | |
ac66f547 PZ |
1169 | if (!cpu_active(arg.src_cpu) || !cpu_active(arg.dst_cpu)) |
1170 | goto out; | |
1171 | ||
1172 | if (!cpumask_test_cpu(arg.dst_cpu, tsk_cpus_allowed(arg.src_task))) | |
1173 | goto out; | |
1174 | ||
1175 | if (!cpumask_test_cpu(arg.src_cpu, tsk_cpus_allowed(arg.dst_task))) | |
1176 | goto out; | |
1177 | ||
286549dc | 1178 | trace_sched_swap_numa(cur, arg.src_cpu, p, arg.dst_cpu); |
ac66f547 PZ |
1179 | ret = stop_two_cpus(arg.dst_cpu, arg.src_cpu, migrate_swap_stop, &arg); |
1180 | ||
1181 | out: | |
ac66f547 PZ |
1182 | return ret; |
1183 | } | |
1184 | ||
969c7921 | 1185 | struct migration_arg { |
36c8b586 | 1186 | struct task_struct *task; |
1da177e4 | 1187 | int dest_cpu; |
70b97a7f | 1188 | }; |
1da177e4 | 1189 | |
969c7921 TH |
1190 | static int migration_cpu_stop(void *data); |
1191 | ||
1da177e4 LT |
1192 | /* |
1193 | * wait_task_inactive - wait for a thread to unschedule. | |
1194 | * | |
85ba2d86 RM |
1195 | * If @match_state is nonzero, it's the @p->state value just checked and |
1196 | * not expected to change. If it changes, i.e. @p might have woken up, | |
1197 | * then return zero. When we succeed in waiting for @p to be off its CPU, | |
1198 | * we return a positive number (its total switch count). If a second call | |
1199 | * a short while later returns the same number, the caller can be sure that | |
1200 | * @p has remained unscheduled the whole time. | |
1201 | * | |
1da177e4 LT |
1202 | * The caller must ensure that the task *will* unschedule sometime soon, |
1203 | * else this function might spin for a *long* time. This function can't | |
1204 | * be called with interrupts off, or it may introduce deadlock with | |
1205 | * smp_call_function() if an IPI is sent by the same process we are | |
1206 | * waiting to become inactive. | |
1207 | */ | |
85ba2d86 | 1208 | unsigned long wait_task_inactive(struct task_struct *p, long match_state) |
1da177e4 LT |
1209 | { |
1210 | unsigned long flags; | |
dd41f596 | 1211 | int running, on_rq; |
85ba2d86 | 1212 | unsigned long ncsw; |
70b97a7f | 1213 | struct rq *rq; |
1da177e4 | 1214 | |
3a5c359a AK |
1215 | for (;;) { |
1216 | /* | |
1217 | * We do the initial early heuristics without holding | |
1218 | * any task-queue locks at all. We'll only try to get | |
1219 | * the runqueue lock when things look like they will | |
1220 | * work out! | |
1221 | */ | |
1222 | rq = task_rq(p); | |
fa490cfd | 1223 | |
3a5c359a AK |
1224 | /* |
1225 | * If the task is actively running on another CPU | |
1226 | * still, just relax and busy-wait without holding | |
1227 | * any locks. | |
1228 | * | |
1229 | * NOTE! Since we don't hold any locks, it's not | |
1230 | * even sure that "rq" stays as the right runqueue! | |
1231 | * But we don't care, since "task_running()" will | |
1232 | * return false if the runqueue has changed and p | |
1233 | * is actually now running somewhere else! | |
1234 | */ | |
85ba2d86 RM |
1235 | while (task_running(rq, p)) { |
1236 | if (match_state && unlikely(p->state != match_state)) | |
1237 | return 0; | |
3a5c359a | 1238 | cpu_relax(); |
85ba2d86 | 1239 | } |
fa490cfd | 1240 | |
3a5c359a AK |
1241 | /* |
1242 | * Ok, time to look more closely! We need the rq | |
1243 | * lock now, to be *sure*. If we're wrong, we'll | |
1244 | * just go back and repeat. | |
1245 | */ | |
1246 | rq = task_rq_lock(p, &flags); | |
27a9da65 | 1247 | trace_sched_wait_task(p); |
3a5c359a | 1248 | running = task_running(rq, p); |
fd2f4419 | 1249 | on_rq = p->on_rq; |
85ba2d86 | 1250 | ncsw = 0; |
f31e11d8 | 1251 | if (!match_state || p->state == match_state) |
93dcf55f | 1252 | ncsw = p->nvcsw | LONG_MIN; /* sets MSB */ |
0122ec5b | 1253 | task_rq_unlock(rq, p, &flags); |
fa490cfd | 1254 | |
85ba2d86 RM |
1255 | /* |
1256 | * If it changed from the expected state, bail out now. | |
1257 | */ | |
1258 | if (unlikely(!ncsw)) | |
1259 | break; | |
1260 | ||
3a5c359a AK |
1261 | /* |
1262 | * Was it really running after all now that we | |
1263 | * checked with the proper locks actually held? | |
1264 | * | |
1265 | * Oops. Go back and try again.. | |
1266 | */ | |
1267 | if (unlikely(running)) { | |
1268 | cpu_relax(); | |
1269 | continue; | |
1270 | } | |
fa490cfd | 1271 | |
3a5c359a AK |
1272 | /* |
1273 | * It's not enough that it's not actively running, | |
1274 | * it must be off the runqueue _entirely_, and not | |
1275 | * preempted! | |
1276 | * | |
80dd99b3 | 1277 | * So if it was still runnable (but just not actively |
3a5c359a AK |
1278 | * running right now), it's preempted, and we should |
1279 | * yield - it could be a while. | |
1280 | */ | |
1281 | if (unlikely(on_rq)) { | |
8eb90c30 TG |
1282 | ktime_t to = ktime_set(0, NSEC_PER_SEC/HZ); |
1283 | ||
1284 | set_current_state(TASK_UNINTERRUPTIBLE); | |
1285 | schedule_hrtimeout(&to, HRTIMER_MODE_REL); | |
3a5c359a AK |
1286 | continue; |
1287 | } | |
fa490cfd | 1288 | |
3a5c359a AK |
1289 | /* |
1290 | * Ahh, all good. It wasn't running, and it wasn't | |
1291 | * runnable, which means that it will never become | |
1292 | * running in the future either. We're all done! | |
1293 | */ | |
1294 | break; | |
1295 | } | |
85ba2d86 RM |
1296 | |
1297 | return ncsw; | |
1da177e4 LT |
1298 | } |
1299 | ||
1300 | /*** | |
1301 | * kick_process - kick a running thread to enter/exit the kernel | |
1302 | * @p: the to-be-kicked thread | |
1303 | * | |
1304 | * Cause a process which is running on another CPU to enter | |
1305 | * kernel-mode, without any delay. (to get signals handled.) | |
1306 | * | |
25985edc | 1307 | * NOTE: this function doesn't have to take the runqueue lock, |
1da177e4 LT |
1308 | * because all it wants to ensure is that the remote task enters |
1309 | * the kernel. If the IPI races and the task has been migrated | |
1310 | * to another CPU then no harm is done and the purpose has been | |
1311 | * achieved as well. | |
1312 | */ | |
36c8b586 | 1313 | void kick_process(struct task_struct *p) |
1da177e4 LT |
1314 | { |
1315 | int cpu; | |
1316 | ||
1317 | preempt_disable(); | |
1318 | cpu = task_cpu(p); | |
1319 | if ((cpu != smp_processor_id()) && task_curr(p)) | |
1320 | smp_send_reschedule(cpu); | |
1321 | preempt_enable(); | |
1322 | } | |
b43e3521 | 1323 | EXPORT_SYMBOL_GPL(kick_process); |
476d139c | 1324 | #endif /* CONFIG_SMP */ |
1da177e4 | 1325 | |
970b13ba | 1326 | #ifdef CONFIG_SMP |
30da688e | 1327 | /* |
013fdb80 | 1328 | * ->cpus_allowed is protected by both rq->lock and p->pi_lock |
30da688e | 1329 | */ |
5da9a0fb PZ |
1330 | static int select_fallback_rq(int cpu, struct task_struct *p) |
1331 | { | |
aa00d89c TC |
1332 | int nid = cpu_to_node(cpu); |
1333 | const struct cpumask *nodemask = NULL; | |
2baab4e9 PZ |
1334 | enum { cpuset, possible, fail } state = cpuset; |
1335 | int dest_cpu; | |
5da9a0fb | 1336 | |
aa00d89c TC |
1337 | /* |
1338 | * If the node that the cpu is on has been offlined, cpu_to_node() | |
1339 | * will return -1. There is no cpu on the node, and we should | |
1340 | * select the cpu on the other node. | |
1341 | */ | |
1342 | if (nid != -1) { | |
1343 | nodemask = cpumask_of_node(nid); | |
1344 | ||
1345 | /* Look for allowed, online CPU in same node. */ | |
1346 | for_each_cpu(dest_cpu, nodemask) { | |
1347 | if (!cpu_online(dest_cpu)) | |
1348 | continue; | |
1349 | if (!cpu_active(dest_cpu)) | |
1350 | continue; | |
1351 | if (cpumask_test_cpu(dest_cpu, tsk_cpus_allowed(p))) | |
1352 | return dest_cpu; | |
1353 | } | |
2baab4e9 | 1354 | } |
5da9a0fb | 1355 | |
2baab4e9 PZ |
1356 | for (;;) { |
1357 | /* Any allowed, online CPU? */ | |
e3831edd | 1358 | for_each_cpu(dest_cpu, tsk_cpus_allowed(p)) { |
2baab4e9 PZ |
1359 | if (!cpu_online(dest_cpu)) |
1360 | continue; | |
1361 | if (!cpu_active(dest_cpu)) | |
1362 | continue; | |
1363 | goto out; | |
1364 | } | |
5da9a0fb | 1365 | |
2baab4e9 PZ |
1366 | switch (state) { |
1367 | case cpuset: | |
1368 | /* No more Mr. Nice Guy. */ | |
1369 | cpuset_cpus_allowed_fallback(p); | |
1370 | state = possible; | |
1371 | break; | |
1372 | ||
1373 | case possible: | |
1374 | do_set_cpus_allowed(p, cpu_possible_mask); | |
1375 | state = fail; | |
1376 | break; | |
1377 | ||
1378 | case fail: | |
1379 | BUG(); | |
1380 | break; | |
1381 | } | |
1382 | } | |
1383 | ||
1384 | out: | |
1385 | if (state != cpuset) { | |
1386 | /* | |
1387 | * Don't tell them about moving exiting tasks or | |
1388 | * kernel threads (both mm NULL), since they never | |
1389 | * leave kernel. | |
1390 | */ | |
1391 | if (p->mm && printk_ratelimit()) { | |
aac74dc4 | 1392 | printk_deferred("process %d (%s) no longer affine to cpu%d\n", |
2baab4e9 PZ |
1393 | task_pid_nr(p), p->comm, cpu); |
1394 | } | |
5da9a0fb PZ |
1395 | } |
1396 | ||
1397 | return dest_cpu; | |
1398 | } | |
1399 | ||
e2912009 | 1400 | /* |
013fdb80 | 1401 | * The caller (fork, wakeup) owns p->pi_lock, ->cpus_allowed is stable. |
e2912009 | 1402 | */ |
970b13ba | 1403 | static inline |
ac66f547 | 1404 | int select_task_rq(struct task_struct *p, int cpu, int sd_flags, int wake_flags) |
970b13ba | 1405 | { |
ac66f547 | 1406 | cpu = p->sched_class->select_task_rq(p, cpu, sd_flags, wake_flags); |
e2912009 PZ |
1407 | |
1408 | /* | |
1409 | * In order not to call set_task_cpu() on a blocking task we need | |
1410 | * to rely on ttwu() to place the task on a valid ->cpus_allowed | |
1411 | * cpu. | |
1412 | * | |
1413 | * Since this is common to all placement strategies, this lives here. | |
1414 | * | |
1415 | * [ this allows ->select_task() to simply return task_cpu(p) and | |
1416 | * not worry about this generic constraint ] | |
1417 | */ | |
fa17b507 | 1418 | if (unlikely(!cpumask_test_cpu(cpu, tsk_cpus_allowed(p)) || |
70f11205 | 1419 | !cpu_online(cpu))) |
5da9a0fb | 1420 | cpu = select_fallback_rq(task_cpu(p), p); |
e2912009 PZ |
1421 | |
1422 | return cpu; | |
970b13ba | 1423 | } |
09a40af5 MG |
1424 | |
1425 | static void update_avg(u64 *avg, u64 sample) | |
1426 | { | |
1427 | s64 diff = sample - *avg; | |
1428 | *avg += diff >> 3; | |
1429 | } | |
970b13ba PZ |
1430 | #endif |
1431 | ||
d7c01d27 | 1432 | static void |
b84cb5df | 1433 | ttwu_stat(struct task_struct *p, int cpu, int wake_flags) |
9ed3811a | 1434 | { |
d7c01d27 | 1435 | #ifdef CONFIG_SCHEDSTATS |
b84cb5df PZ |
1436 | struct rq *rq = this_rq(); |
1437 | ||
d7c01d27 PZ |
1438 | #ifdef CONFIG_SMP |
1439 | int this_cpu = smp_processor_id(); | |
1440 | ||
1441 | if (cpu == this_cpu) { | |
1442 | schedstat_inc(rq, ttwu_local); | |
1443 | schedstat_inc(p, se.statistics.nr_wakeups_local); | |
1444 | } else { | |
1445 | struct sched_domain *sd; | |
1446 | ||
1447 | schedstat_inc(p, se.statistics.nr_wakeups_remote); | |
057f3fad | 1448 | rcu_read_lock(); |
d7c01d27 PZ |
1449 | for_each_domain(this_cpu, sd) { |
1450 | if (cpumask_test_cpu(cpu, sched_domain_span(sd))) { | |
1451 | schedstat_inc(sd, ttwu_wake_remote); | |
1452 | break; | |
1453 | } | |
1454 | } | |
057f3fad | 1455 | rcu_read_unlock(); |
d7c01d27 | 1456 | } |
f339b9dc PZ |
1457 | |
1458 | if (wake_flags & WF_MIGRATED) | |
1459 | schedstat_inc(p, se.statistics.nr_wakeups_migrate); | |
1460 | ||
d7c01d27 PZ |
1461 | #endif /* CONFIG_SMP */ |
1462 | ||
1463 | schedstat_inc(rq, ttwu_count); | |
9ed3811a | 1464 | schedstat_inc(p, se.statistics.nr_wakeups); |
d7c01d27 PZ |
1465 | |
1466 | if (wake_flags & WF_SYNC) | |
9ed3811a | 1467 | schedstat_inc(p, se.statistics.nr_wakeups_sync); |
d7c01d27 | 1468 | |
d7c01d27 PZ |
1469 | #endif /* CONFIG_SCHEDSTATS */ |
1470 | } | |
1471 | ||
1472 | static void ttwu_activate(struct rq *rq, struct task_struct *p, int en_flags) | |
1473 | { | |
9ed3811a | 1474 | activate_task(rq, p, en_flags); |
fd2f4419 | 1475 | p->on_rq = 1; |
c2f7115e PZ |
1476 | |
1477 | /* if a worker is waking up, notify workqueue */ | |
1478 | if (p->flags & PF_WQ_WORKER) | |
1479 | wq_worker_waking_up(p, cpu_of(rq)); | |
9ed3811a TH |
1480 | } |
1481 | ||
23f41eeb PZ |
1482 | /* |
1483 | * Mark the task runnable and perform wakeup-preemption. | |
1484 | */ | |
89363381 | 1485 | static void |
23f41eeb | 1486 | ttwu_do_wakeup(struct rq *rq, struct task_struct *p, int wake_flags) |
9ed3811a | 1487 | { |
9ed3811a | 1488 | check_preempt_curr(rq, p, wake_flags); |
a8d7ad52 | 1489 | trace_sched_wakeup(p, true); |
9ed3811a TH |
1490 | |
1491 | p->state = TASK_RUNNING; | |
1492 | #ifdef CONFIG_SMP | |
1493 | if (p->sched_class->task_woken) | |
1494 | p->sched_class->task_woken(rq, p); | |
1495 | ||
e69c6341 | 1496 | if (rq->idle_stamp) { |
78becc27 | 1497 | u64 delta = rq_clock(rq) - rq->idle_stamp; |
9bd721c5 | 1498 | u64 max = 2*rq->max_idle_balance_cost; |
9ed3811a | 1499 | |
abfafa54 JL |
1500 | update_avg(&rq->avg_idle, delta); |
1501 | ||
1502 | if (rq->avg_idle > max) | |
9ed3811a | 1503 | rq->avg_idle = max; |
abfafa54 | 1504 | |
9ed3811a TH |
1505 | rq->idle_stamp = 0; |
1506 | } | |
1507 | #endif | |
1508 | } | |
1509 | ||
c05fbafb PZ |
1510 | static void |
1511 | ttwu_do_activate(struct rq *rq, struct task_struct *p, int wake_flags) | |
1512 | { | |
1513 | #ifdef CONFIG_SMP | |
1514 | if (p->sched_contributes_to_load) | |
1515 | rq->nr_uninterruptible--; | |
1516 | #endif | |
1517 | ||
1518 | ttwu_activate(rq, p, ENQUEUE_WAKEUP | ENQUEUE_WAKING); | |
1519 | ttwu_do_wakeup(rq, p, wake_flags); | |
1520 | } | |
1521 | ||
1522 | /* | |
1523 | * Called in case the task @p isn't fully descheduled from its runqueue, | |
1524 | * in this case we must do a remote wakeup. Its a 'light' wakeup though, | |
1525 | * since all we need to do is flip p->state to TASK_RUNNING, since | |
1526 | * the task is still ->on_rq. | |
1527 | */ | |
1528 | static int ttwu_remote(struct task_struct *p, int wake_flags) | |
1529 | { | |
1530 | struct rq *rq; | |
1531 | int ret = 0; | |
1532 | ||
1533 | rq = __task_rq_lock(p); | |
1534 | if (p->on_rq) { | |
1ad4ec0d FW |
1535 | /* check_preempt_curr() may use rq clock */ |
1536 | update_rq_clock(rq); | |
c05fbafb PZ |
1537 | ttwu_do_wakeup(rq, p, wake_flags); |
1538 | ret = 1; | |
1539 | } | |
1540 | __task_rq_unlock(rq); | |
1541 | ||
1542 | return ret; | |
1543 | } | |
1544 | ||
317f3941 | 1545 | #ifdef CONFIG_SMP |
e3baac47 | 1546 | void sched_ttwu_pending(void) |
317f3941 PZ |
1547 | { |
1548 | struct rq *rq = this_rq(); | |
fa14ff4a PZ |
1549 | struct llist_node *llist = llist_del_all(&rq->wake_list); |
1550 | struct task_struct *p; | |
e3baac47 | 1551 | unsigned long flags; |
317f3941 | 1552 | |
e3baac47 PZ |
1553 | if (!llist) |
1554 | return; | |
1555 | ||
1556 | raw_spin_lock_irqsave(&rq->lock, flags); | |
317f3941 | 1557 | |
fa14ff4a PZ |
1558 | while (llist) { |
1559 | p = llist_entry(llist, struct task_struct, wake_entry); | |
1560 | llist = llist_next(llist); | |
317f3941 PZ |
1561 | ttwu_do_activate(rq, p, 0); |
1562 | } | |
1563 | ||
e3baac47 | 1564 | raw_spin_unlock_irqrestore(&rq->lock, flags); |
317f3941 PZ |
1565 | } |
1566 | ||
1567 | void scheduler_ipi(void) | |
1568 | { | |
f27dde8d PZ |
1569 | /* |
1570 | * Fold TIF_NEED_RESCHED into the preempt_count; anybody setting | |
1571 | * TIF_NEED_RESCHED remotely (for the first time) will also send | |
1572 | * this IPI. | |
1573 | */ | |
8cb75e0c | 1574 | preempt_fold_need_resched(); |
f27dde8d | 1575 | |
fd2ac4f4 | 1576 | if (llist_empty(&this_rq()->wake_list) && !got_nohz_idle_kick()) |
c5d753a5 PZ |
1577 | return; |
1578 | ||
1579 | /* | |
1580 | * Not all reschedule IPI handlers call irq_enter/irq_exit, since | |
1581 | * traditionally all their work was done from the interrupt return | |
1582 | * path. Now that we actually do some work, we need to make sure | |
1583 | * we do call them. | |
1584 | * | |
1585 | * Some archs already do call them, luckily irq_enter/exit nest | |
1586 | * properly. | |
1587 | * | |
1588 | * Arguably we should visit all archs and update all handlers, | |
1589 | * however a fair share of IPIs are still resched only so this would | |
1590 | * somewhat pessimize the simple resched case. | |
1591 | */ | |
1592 | irq_enter(); | |
fa14ff4a | 1593 | sched_ttwu_pending(); |
ca38062e SS |
1594 | |
1595 | /* | |
1596 | * Check if someone kicked us for doing the nohz idle load balance. | |
1597 | */ | |
873b4c65 | 1598 | if (unlikely(got_nohz_idle_kick())) { |
6eb57e0d | 1599 | this_rq()->idle_balance = 1; |
ca38062e | 1600 | raise_softirq_irqoff(SCHED_SOFTIRQ); |
6eb57e0d | 1601 | } |
c5d753a5 | 1602 | irq_exit(); |
317f3941 PZ |
1603 | } |
1604 | ||
1605 | static void ttwu_queue_remote(struct task_struct *p, int cpu) | |
1606 | { | |
e3baac47 PZ |
1607 | struct rq *rq = cpu_rq(cpu); |
1608 | ||
1609 | if (llist_add(&p->wake_entry, &cpu_rq(cpu)->wake_list)) { | |
1610 | if (!set_nr_if_polling(rq->idle)) | |
1611 | smp_send_reschedule(cpu); | |
1612 | else | |
1613 | trace_sched_wake_idle_without_ipi(cpu); | |
1614 | } | |
317f3941 | 1615 | } |
d6aa8f85 | 1616 | |
39be3501 | 1617 | bool cpus_share_cache(int this_cpu, int that_cpu) |
518cd623 PZ |
1618 | { |
1619 | return per_cpu(sd_llc_id, this_cpu) == per_cpu(sd_llc_id, that_cpu); | |
1620 | } | |
d6aa8f85 | 1621 | #endif /* CONFIG_SMP */ |
317f3941 | 1622 | |
c05fbafb PZ |
1623 | static void ttwu_queue(struct task_struct *p, int cpu) |
1624 | { | |
1625 | struct rq *rq = cpu_rq(cpu); | |
1626 | ||
17d9f311 | 1627 | #if defined(CONFIG_SMP) |
39be3501 | 1628 | if (sched_feat(TTWU_QUEUE) && !cpus_share_cache(smp_processor_id(), cpu)) { |
f01114cb | 1629 | sched_clock_cpu(cpu); /* sync clocks x-cpu */ |
317f3941 PZ |
1630 | ttwu_queue_remote(p, cpu); |
1631 | return; | |
1632 | } | |
1633 | #endif | |
1634 | ||
c05fbafb PZ |
1635 | raw_spin_lock(&rq->lock); |
1636 | ttwu_do_activate(rq, p, 0); | |
1637 | raw_spin_unlock(&rq->lock); | |
9ed3811a TH |
1638 | } |
1639 | ||
1640 | /** | |
1da177e4 | 1641 | * try_to_wake_up - wake up a thread |
9ed3811a | 1642 | * @p: the thread to be awakened |
1da177e4 | 1643 | * @state: the mask of task states that can be woken |
9ed3811a | 1644 | * @wake_flags: wake modifier flags (WF_*) |
1da177e4 LT |
1645 | * |
1646 | * Put it on the run-queue if it's not already there. The "current" | |
1647 | * thread is always on the run-queue (except when the actual | |
1648 | * re-schedule is in progress), and as such you're allowed to do | |
1649 | * the simpler "current->state = TASK_RUNNING" to mark yourself | |
1650 | * runnable without the overhead of this. | |
1651 | * | |
e69f6186 | 1652 | * Return: %true if @p was woken up, %false if it was already running. |
9ed3811a | 1653 | * or @state didn't match @p's state. |
1da177e4 | 1654 | */ |
e4a52bcb PZ |
1655 | static int |
1656 | try_to_wake_up(struct task_struct *p, unsigned int state, int wake_flags) | |
1da177e4 | 1657 | { |
1da177e4 | 1658 | unsigned long flags; |
c05fbafb | 1659 | int cpu, success = 0; |
2398f2c6 | 1660 | |
e0acd0a6 ON |
1661 | /* |
1662 | * If we are going to wake up a thread waiting for CONDITION we | |
1663 | * need to ensure that CONDITION=1 done by the caller can not be | |
1664 | * reordered with p->state check below. This pairs with mb() in | |
1665 | * set_current_state() the waiting thread does. | |
1666 | */ | |
1667 | smp_mb__before_spinlock(); | |
013fdb80 | 1668 | raw_spin_lock_irqsave(&p->pi_lock, flags); |
e9c84311 | 1669 | if (!(p->state & state)) |
1da177e4 LT |
1670 | goto out; |
1671 | ||
c05fbafb | 1672 | success = 1; /* we're going to change ->state */ |
1da177e4 | 1673 | cpu = task_cpu(p); |
1da177e4 | 1674 | |
c05fbafb PZ |
1675 | if (p->on_rq && ttwu_remote(p, wake_flags)) |
1676 | goto stat; | |
1da177e4 | 1677 | |
1da177e4 | 1678 | #ifdef CONFIG_SMP |
e9c84311 | 1679 | /* |
c05fbafb PZ |
1680 | * If the owning (remote) cpu is still in the middle of schedule() with |
1681 | * this task as prev, wait until its done referencing the task. | |
e9c84311 | 1682 | */ |
f3e94786 | 1683 | while (p->on_cpu) |
e4a52bcb | 1684 | cpu_relax(); |
0970d299 | 1685 | /* |
e4a52bcb | 1686 | * Pairs with the smp_wmb() in finish_lock_switch(). |
0970d299 | 1687 | */ |
e4a52bcb | 1688 | smp_rmb(); |
1da177e4 | 1689 | |
a8e4f2ea | 1690 | p->sched_contributes_to_load = !!task_contributes_to_load(p); |
e9c84311 | 1691 | p->state = TASK_WAKING; |
e7693a36 | 1692 | |
e4a52bcb | 1693 | if (p->sched_class->task_waking) |
74f8e4b2 | 1694 | p->sched_class->task_waking(p); |
efbbd05a | 1695 | |
ac66f547 | 1696 | cpu = select_task_rq(p, p->wake_cpu, SD_BALANCE_WAKE, wake_flags); |
f339b9dc PZ |
1697 | if (task_cpu(p) != cpu) { |
1698 | wake_flags |= WF_MIGRATED; | |
e4a52bcb | 1699 | set_task_cpu(p, cpu); |
f339b9dc | 1700 | } |
1da177e4 | 1701 | #endif /* CONFIG_SMP */ |
1da177e4 | 1702 | |
c05fbafb PZ |
1703 | ttwu_queue(p, cpu); |
1704 | stat: | |
b84cb5df | 1705 | ttwu_stat(p, cpu, wake_flags); |
1da177e4 | 1706 | out: |
013fdb80 | 1707 | raw_spin_unlock_irqrestore(&p->pi_lock, flags); |
1da177e4 LT |
1708 | |
1709 | return success; | |
1710 | } | |
1711 | ||
21aa9af0 TH |
1712 | /** |
1713 | * try_to_wake_up_local - try to wake up a local task with rq lock held | |
1714 | * @p: the thread to be awakened | |
1715 | * | |
2acca55e | 1716 | * Put @p on the run-queue if it's not already there. The caller must |
21aa9af0 | 1717 | * ensure that this_rq() is locked, @p is bound to this_rq() and not |
2acca55e | 1718 | * the current task. |
21aa9af0 TH |
1719 | */ |
1720 | static void try_to_wake_up_local(struct task_struct *p) | |
1721 | { | |
1722 | struct rq *rq = task_rq(p); | |
21aa9af0 | 1723 | |
383efcd0 TH |
1724 | if (WARN_ON_ONCE(rq != this_rq()) || |
1725 | WARN_ON_ONCE(p == current)) | |
1726 | return; | |
1727 | ||
21aa9af0 TH |
1728 | lockdep_assert_held(&rq->lock); |
1729 | ||
2acca55e PZ |
1730 | if (!raw_spin_trylock(&p->pi_lock)) { |
1731 | raw_spin_unlock(&rq->lock); | |
1732 | raw_spin_lock(&p->pi_lock); | |
1733 | raw_spin_lock(&rq->lock); | |
1734 | } | |
1735 | ||
21aa9af0 | 1736 | if (!(p->state & TASK_NORMAL)) |
2acca55e | 1737 | goto out; |
21aa9af0 | 1738 | |
fd2f4419 | 1739 | if (!p->on_rq) |
d7c01d27 PZ |
1740 | ttwu_activate(rq, p, ENQUEUE_WAKEUP); |
1741 | ||
23f41eeb | 1742 | ttwu_do_wakeup(rq, p, 0); |
b84cb5df | 1743 | ttwu_stat(p, smp_processor_id(), 0); |
2acca55e PZ |
1744 | out: |
1745 | raw_spin_unlock(&p->pi_lock); | |
21aa9af0 TH |
1746 | } |
1747 | ||
50fa610a DH |
1748 | /** |
1749 | * wake_up_process - Wake up a specific process | |
1750 | * @p: The process to be woken up. | |
1751 | * | |
1752 | * Attempt to wake up the nominated process and move it to the set of runnable | |
e69f6186 YB |
1753 | * processes. |
1754 | * | |
1755 | * Return: 1 if the process was woken up, 0 if it was already running. | |
50fa610a DH |
1756 | * |
1757 | * It may be assumed that this function implies a write memory barrier before | |
1758 | * changing the task state if and only if any tasks are woken up. | |
1759 | */ | |
7ad5b3a5 | 1760 | int wake_up_process(struct task_struct *p) |
1da177e4 | 1761 | { |
9067ac85 ON |
1762 | WARN_ON(task_is_stopped_or_traced(p)); |
1763 | return try_to_wake_up(p, TASK_NORMAL, 0); | |
1da177e4 | 1764 | } |
1da177e4 LT |
1765 | EXPORT_SYMBOL(wake_up_process); |
1766 | ||
7ad5b3a5 | 1767 | int wake_up_state(struct task_struct *p, unsigned int state) |
1da177e4 LT |
1768 | { |
1769 | return try_to_wake_up(p, state, 0); | |
1770 | } | |
1771 | ||
1da177e4 LT |
1772 | /* |
1773 | * Perform scheduler related setup for a newly forked process p. | |
1774 | * p is forked by current. | |
dd41f596 IM |
1775 | * |
1776 | * __sched_fork() is basic setup used by init_idle() too: | |
1777 | */ | |
5e1576ed | 1778 | static void __sched_fork(unsigned long clone_flags, struct task_struct *p) |
dd41f596 | 1779 | { |
fd2f4419 PZ |
1780 | p->on_rq = 0; |
1781 | ||
1782 | p->se.on_rq = 0; | |
dd41f596 IM |
1783 | p->se.exec_start = 0; |
1784 | p->se.sum_exec_runtime = 0; | |
f6cf891c | 1785 | p->se.prev_sum_exec_runtime = 0; |
6c594c21 | 1786 | p->se.nr_migrations = 0; |
da7a735e | 1787 | p->se.vruntime = 0; |
fd2f4419 | 1788 | INIT_LIST_HEAD(&p->se.group_node); |
6cfb0d5d IM |
1789 | |
1790 | #ifdef CONFIG_SCHEDSTATS | |
41acab88 | 1791 | memset(&p->se.statistics, 0, sizeof(p->se.statistics)); |
6cfb0d5d | 1792 | #endif |
476d139c | 1793 | |
aab03e05 DF |
1794 | RB_CLEAR_NODE(&p->dl.rb_node); |
1795 | hrtimer_init(&p->dl.dl_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); | |
1796 | p->dl.dl_runtime = p->dl.runtime = 0; | |
1797 | p->dl.dl_deadline = p->dl.deadline = 0; | |
755378a4 | 1798 | p->dl.dl_period = 0; |
aab03e05 DF |
1799 | p->dl.flags = 0; |
1800 | ||
fa717060 | 1801 | INIT_LIST_HEAD(&p->rt.run_list); |
476d139c | 1802 | |
e107be36 AK |
1803 | #ifdef CONFIG_PREEMPT_NOTIFIERS |
1804 | INIT_HLIST_HEAD(&p->preempt_notifiers); | |
1805 | #endif | |
cbee9f88 PZ |
1806 | |
1807 | #ifdef CONFIG_NUMA_BALANCING | |
1808 | if (p->mm && atomic_read(&p->mm->mm_users) == 1) { | |
7e8d16b6 | 1809 | p->mm->numa_next_scan = jiffies + msecs_to_jiffies(sysctl_numa_balancing_scan_delay); |
cbee9f88 PZ |
1810 | p->mm->numa_scan_seq = 0; |
1811 | } | |
1812 | ||
5e1576ed RR |
1813 | if (clone_flags & CLONE_VM) |
1814 | p->numa_preferred_nid = current->numa_preferred_nid; | |
1815 | else | |
1816 | p->numa_preferred_nid = -1; | |
1817 | ||
cbee9f88 PZ |
1818 | p->node_stamp = 0ULL; |
1819 | p->numa_scan_seq = p->mm ? p->mm->numa_scan_seq : 0; | |
4b96a29b | 1820 | p->numa_scan_period = sysctl_numa_balancing_scan_delay; |
cbee9f88 | 1821 | p->numa_work.next = &p->numa_work; |
ff1df896 RR |
1822 | p->numa_faults_memory = NULL; |
1823 | p->numa_faults_buffer_memory = NULL; | |
7e2703e6 RR |
1824 | p->last_task_numa_placement = 0; |
1825 | p->last_sum_exec_runtime = 0; | |
8c8a743c PZ |
1826 | |
1827 | INIT_LIST_HEAD(&p->numa_entry); | |
1828 | p->numa_group = NULL; | |
cbee9f88 | 1829 | #endif /* CONFIG_NUMA_BALANCING */ |
dd41f596 IM |
1830 | } |
1831 | ||
1a687c2e | 1832 | #ifdef CONFIG_NUMA_BALANCING |
3105b86a | 1833 | #ifdef CONFIG_SCHED_DEBUG |
1a687c2e MG |
1834 | void set_numabalancing_state(bool enabled) |
1835 | { | |
1836 | if (enabled) | |
1837 | sched_feat_set("NUMA"); | |
1838 | else | |
1839 | sched_feat_set("NO_NUMA"); | |
1840 | } | |
3105b86a MG |
1841 | #else |
1842 | __read_mostly bool numabalancing_enabled; | |
1843 | ||
1844 | void set_numabalancing_state(bool enabled) | |
1845 | { | |
1846 | numabalancing_enabled = enabled; | |
dd41f596 | 1847 | } |
3105b86a | 1848 | #endif /* CONFIG_SCHED_DEBUG */ |
54a43d54 AK |
1849 | |
1850 | #ifdef CONFIG_PROC_SYSCTL | |
1851 | int sysctl_numa_balancing(struct ctl_table *table, int write, | |
1852 | void __user *buffer, size_t *lenp, loff_t *ppos) | |
1853 | { | |
1854 | struct ctl_table t; | |
1855 | int err; | |
1856 | int state = numabalancing_enabled; | |
1857 | ||
1858 | if (write && !capable(CAP_SYS_ADMIN)) | |
1859 | return -EPERM; | |
1860 | ||
1861 | t = *table; | |
1862 | t.data = &state; | |
1863 | err = proc_dointvec_minmax(&t, write, buffer, lenp, ppos); | |
1864 | if (err < 0) | |
1865 | return err; | |
1866 | if (write) | |
1867 | set_numabalancing_state(state); | |
1868 | return err; | |
1869 | } | |
1870 | #endif | |
1871 | #endif | |
dd41f596 IM |
1872 | |
1873 | /* | |
1874 | * fork()/clone()-time setup: | |
1875 | */ | |
aab03e05 | 1876 | int sched_fork(unsigned long clone_flags, struct task_struct *p) |
dd41f596 | 1877 | { |
0122ec5b | 1878 | unsigned long flags; |
dd41f596 IM |
1879 | int cpu = get_cpu(); |
1880 | ||
5e1576ed | 1881 | __sched_fork(clone_flags, p); |
06b83b5f | 1882 | /* |
0017d735 | 1883 | * We mark the process as running here. This guarantees that |
06b83b5f PZ |
1884 | * nobody will actually run it, and a signal or other external |
1885 | * event cannot wake it up and insert it on the runqueue either. | |
1886 | */ | |
0017d735 | 1887 | p->state = TASK_RUNNING; |
dd41f596 | 1888 | |
c350a04e MG |
1889 | /* |
1890 | * Make sure we do not leak PI boosting priority to the child. | |
1891 | */ | |
1892 | p->prio = current->normal_prio; | |
1893 | ||
b9dc29e7 MG |
1894 | /* |
1895 | * Revert to default priority/policy on fork if requested. | |
1896 | */ | |
1897 | if (unlikely(p->sched_reset_on_fork)) { | |
aab03e05 | 1898 | if (task_has_dl_policy(p) || task_has_rt_policy(p)) { |
b9dc29e7 | 1899 | p->policy = SCHED_NORMAL; |
6c697bdf | 1900 | p->static_prio = NICE_TO_PRIO(0); |
c350a04e MG |
1901 | p->rt_priority = 0; |
1902 | } else if (PRIO_TO_NICE(p->static_prio) < 0) | |
1903 | p->static_prio = NICE_TO_PRIO(0); | |
1904 | ||
1905 | p->prio = p->normal_prio = __normal_prio(p); | |
1906 | set_load_weight(p); | |
6c697bdf | 1907 | |
b9dc29e7 MG |
1908 | /* |
1909 | * We don't need the reset flag anymore after the fork. It has | |
1910 | * fulfilled its duty: | |
1911 | */ | |
1912 | p->sched_reset_on_fork = 0; | |
1913 | } | |
ca94c442 | 1914 | |
aab03e05 DF |
1915 | if (dl_prio(p->prio)) { |
1916 | put_cpu(); | |
1917 | return -EAGAIN; | |
1918 | } else if (rt_prio(p->prio)) { | |
1919 | p->sched_class = &rt_sched_class; | |
1920 | } else { | |
2ddbf952 | 1921 | p->sched_class = &fair_sched_class; |
aab03e05 | 1922 | } |
b29739f9 | 1923 | |
cd29fe6f PZ |
1924 | if (p->sched_class->task_fork) |
1925 | p->sched_class->task_fork(p); | |
1926 | ||
86951599 PZ |
1927 | /* |
1928 | * The child is not yet in the pid-hash so no cgroup attach races, | |
1929 | * and the cgroup is pinned to this child due to cgroup_fork() | |
1930 | * is ran before sched_fork(). | |
1931 | * | |
1932 | * Silence PROVE_RCU. | |
1933 | */ | |
0122ec5b | 1934 | raw_spin_lock_irqsave(&p->pi_lock, flags); |
5f3edc1b | 1935 | set_task_cpu(p, cpu); |
0122ec5b | 1936 | raw_spin_unlock_irqrestore(&p->pi_lock, flags); |
5f3edc1b | 1937 | |
52f17b6c | 1938 | #if defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT) |
dd41f596 | 1939 | if (likely(sched_info_on())) |
52f17b6c | 1940 | memset(&p->sched_info, 0, sizeof(p->sched_info)); |
1da177e4 | 1941 | #endif |
3ca7a440 PZ |
1942 | #if defined(CONFIG_SMP) |
1943 | p->on_cpu = 0; | |
4866cde0 | 1944 | #endif |
01028747 | 1945 | init_task_preempt_count(p); |
806c09a7 | 1946 | #ifdef CONFIG_SMP |
917b627d | 1947 | plist_node_init(&p->pushable_tasks, MAX_PRIO); |
1baca4ce | 1948 | RB_CLEAR_NODE(&p->pushable_dl_tasks); |
806c09a7 | 1949 | #endif |
917b627d | 1950 | |
476d139c | 1951 | put_cpu(); |
aab03e05 | 1952 | return 0; |
1da177e4 LT |
1953 | } |
1954 | ||
332ac17e DF |
1955 | unsigned long to_ratio(u64 period, u64 runtime) |
1956 | { | |
1957 | if (runtime == RUNTIME_INF) | |
1958 | return 1ULL << 20; | |
1959 | ||
1960 | /* | |
1961 | * Doing this here saves a lot of checks in all | |
1962 | * the calling paths, and returning zero seems | |
1963 | * safe for them anyway. | |
1964 | */ | |
1965 | if (period == 0) | |
1966 | return 0; | |
1967 | ||
1968 | return div64_u64(runtime << 20, period); | |
1969 | } | |
1970 | ||
1971 | #ifdef CONFIG_SMP | |
1972 | inline struct dl_bw *dl_bw_of(int i) | |
1973 | { | |
1974 | return &cpu_rq(i)->rd->dl_bw; | |
1975 | } | |
1976 | ||
de212f18 | 1977 | static inline int dl_bw_cpus(int i) |
332ac17e | 1978 | { |
de212f18 PZ |
1979 | struct root_domain *rd = cpu_rq(i)->rd; |
1980 | int cpus = 0; | |
1981 | ||
1982 | for_each_cpu_and(i, rd->span, cpu_active_mask) | |
1983 | cpus++; | |
1984 | ||
1985 | return cpus; | |
332ac17e DF |
1986 | } |
1987 | #else | |
1988 | inline struct dl_bw *dl_bw_of(int i) | |
1989 | { | |
1990 | return &cpu_rq(i)->dl.dl_bw; | |
1991 | } | |
1992 | ||
de212f18 | 1993 | static inline int dl_bw_cpus(int i) |
332ac17e DF |
1994 | { |
1995 | return 1; | |
1996 | } | |
1997 | #endif | |
1998 | ||
1999 | static inline | |
2000 | void __dl_clear(struct dl_bw *dl_b, u64 tsk_bw) | |
2001 | { | |
2002 | dl_b->total_bw -= tsk_bw; | |
2003 | } | |
2004 | ||
2005 | static inline | |
2006 | void __dl_add(struct dl_bw *dl_b, u64 tsk_bw) | |
2007 | { | |
2008 | dl_b->total_bw += tsk_bw; | |
2009 | } | |
2010 | ||
2011 | static inline | |
2012 | bool __dl_overflow(struct dl_bw *dl_b, int cpus, u64 old_bw, u64 new_bw) | |
2013 | { | |
2014 | return dl_b->bw != -1 && | |
2015 | dl_b->bw * cpus < dl_b->total_bw - old_bw + new_bw; | |
2016 | } | |
2017 | ||
2018 | /* | |
2019 | * We must be sure that accepting a new task (or allowing changing the | |
2020 | * parameters of an existing one) is consistent with the bandwidth | |
2021 | * constraints. If yes, this function also accordingly updates the currently | |
2022 | * allocated bandwidth to reflect the new situation. | |
2023 | * | |
2024 | * This function is called while holding p's rq->lock. | |
2025 | */ | |
2026 | static int dl_overflow(struct task_struct *p, int policy, | |
2027 | const struct sched_attr *attr) | |
2028 | { | |
2029 | ||
2030 | struct dl_bw *dl_b = dl_bw_of(task_cpu(p)); | |
4df1638c | 2031 | u64 period = attr->sched_period ?: attr->sched_deadline; |
332ac17e DF |
2032 | u64 runtime = attr->sched_runtime; |
2033 | u64 new_bw = dl_policy(policy) ? to_ratio(period, runtime) : 0; | |
de212f18 | 2034 | int cpus, err = -1; |
332ac17e DF |
2035 | |
2036 | if (new_bw == p->dl.dl_bw) | |
2037 | return 0; | |
2038 | ||
2039 | /* | |
2040 | * Either if a task, enters, leave, or stays -deadline but changes | |
2041 | * its parameters, we may need to update accordingly the total | |
2042 | * allocated bandwidth of the container. | |
2043 | */ | |
2044 | raw_spin_lock(&dl_b->lock); | |
de212f18 | 2045 | cpus = dl_bw_cpus(task_cpu(p)); |
332ac17e DF |
2046 | if (dl_policy(policy) && !task_has_dl_policy(p) && |
2047 | !__dl_overflow(dl_b, cpus, 0, new_bw)) { | |
2048 | __dl_add(dl_b, new_bw); | |
2049 | err = 0; | |
2050 | } else if (dl_policy(policy) && task_has_dl_policy(p) && | |
2051 | !__dl_overflow(dl_b, cpus, p->dl.dl_bw, new_bw)) { | |
2052 | __dl_clear(dl_b, p->dl.dl_bw); | |
2053 | __dl_add(dl_b, new_bw); | |
2054 | err = 0; | |
2055 | } else if (!dl_policy(policy) && task_has_dl_policy(p)) { | |
2056 | __dl_clear(dl_b, p->dl.dl_bw); | |
2057 | err = 0; | |
2058 | } | |
2059 | raw_spin_unlock(&dl_b->lock); | |
2060 | ||
2061 | return err; | |
2062 | } | |
2063 | ||
2064 | extern void init_dl_bw(struct dl_bw *dl_b); | |
2065 | ||
1da177e4 LT |
2066 | /* |
2067 | * wake_up_new_task - wake up a newly created task for the first time. | |
2068 | * | |
2069 | * This function will do some initial scheduler statistics housekeeping | |
2070 | * that must be done for every newly created context, then puts the task | |
2071 | * on the runqueue and wakes it. | |
2072 | */ | |
3e51e3ed | 2073 | void wake_up_new_task(struct task_struct *p) |
1da177e4 LT |
2074 | { |
2075 | unsigned long flags; | |
dd41f596 | 2076 | struct rq *rq; |
fabf318e | 2077 | |
ab2515c4 | 2078 | raw_spin_lock_irqsave(&p->pi_lock, flags); |
fabf318e PZ |
2079 | #ifdef CONFIG_SMP |
2080 | /* | |
2081 | * Fork balancing, do it here and not earlier because: | |
2082 | * - cpus_allowed can change in the fork path | |
2083 | * - any previously selected cpu might disappear through hotplug | |
fabf318e | 2084 | */ |
ac66f547 | 2085 | set_task_cpu(p, select_task_rq(p, task_cpu(p), SD_BALANCE_FORK, 0)); |
0017d735 PZ |
2086 | #endif |
2087 | ||
a75cdaa9 AS |
2088 | /* Initialize new task's runnable average */ |
2089 | init_task_runnable_average(p); | |
ab2515c4 | 2090 | rq = __task_rq_lock(p); |
cd29fe6f | 2091 | activate_task(rq, p, 0); |
fd2f4419 | 2092 | p->on_rq = 1; |
89363381 | 2093 | trace_sched_wakeup_new(p, true); |
a7558e01 | 2094 | check_preempt_curr(rq, p, WF_FORK); |
9a897c5a | 2095 | #ifdef CONFIG_SMP |
efbbd05a PZ |
2096 | if (p->sched_class->task_woken) |
2097 | p->sched_class->task_woken(rq, p); | |
9a897c5a | 2098 | #endif |
0122ec5b | 2099 | task_rq_unlock(rq, p, &flags); |
1da177e4 LT |
2100 | } |
2101 | ||
e107be36 AK |
2102 | #ifdef CONFIG_PREEMPT_NOTIFIERS |
2103 | ||
2104 | /** | |
80dd99b3 | 2105 | * preempt_notifier_register - tell me when current is being preempted & rescheduled |
421cee29 | 2106 | * @notifier: notifier struct to register |
e107be36 AK |
2107 | */ |
2108 | void preempt_notifier_register(struct preempt_notifier *notifier) | |
2109 | { | |
2110 | hlist_add_head(¬ifier->link, ¤t->preempt_notifiers); | |
2111 | } | |
2112 | EXPORT_SYMBOL_GPL(preempt_notifier_register); | |
2113 | ||
2114 | /** | |
2115 | * preempt_notifier_unregister - no longer interested in preemption notifications | |
421cee29 | 2116 | * @notifier: notifier struct to unregister |
e107be36 AK |
2117 | * |
2118 | * This is safe to call from within a preemption notifier. | |
2119 | */ | |
2120 | void preempt_notifier_unregister(struct preempt_notifier *notifier) | |
2121 | { | |
2122 | hlist_del(¬ifier->link); | |
2123 | } | |
2124 | EXPORT_SYMBOL_GPL(preempt_notifier_unregister); | |
2125 | ||
2126 | static void fire_sched_in_preempt_notifiers(struct task_struct *curr) | |
2127 | { | |
2128 | struct preempt_notifier *notifier; | |
e107be36 | 2129 | |
b67bfe0d | 2130 | hlist_for_each_entry(notifier, &curr->preempt_notifiers, link) |
e107be36 AK |
2131 | notifier->ops->sched_in(notifier, raw_smp_processor_id()); |
2132 | } | |
2133 | ||
2134 | static void | |
2135 | fire_sched_out_preempt_notifiers(struct task_struct *curr, | |
2136 | struct task_struct *next) | |
2137 | { | |
2138 | struct preempt_notifier *notifier; | |
e107be36 | 2139 | |
b67bfe0d | 2140 | hlist_for_each_entry(notifier, &curr->preempt_notifiers, link) |
e107be36 AK |
2141 | notifier->ops->sched_out(notifier, next); |
2142 | } | |
2143 | ||
6d6bc0ad | 2144 | #else /* !CONFIG_PREEMPT_NOTIFIERS */ |
e107be36 AK |
2145 | |
2146 | static void fire_sched_in_preempt_notifiers(struct task_struct *curr) | |
2147 | { | |
2148 | } | |
2149 | ||
2150 | static void | |
2151 | fire_sched_out_preempt_notifiers(struct task_struct *curr, | |
2152 | struct task_struct *next) | |
2153 | { | |
2154 | } | |
2155 | ||
6d6bc0ad | 2156 | #endif /* CONFIG_PREEMPT_NOTIFIERS */ |
e107be36 | 2157 | |
4866cde0 NP |
2158 | /** |
2159 | * prepare_task_switch - prepare to switch tasks | |
2160 | * @rq: the runqueue preparing to switch | |
421cee29 | 2161 | * @prev: the current task that is being switched out |
4866cde0 NP |
2162 | * @next: the task we are going to switch to. |
2163 | * | |
2164 | * This is called with the rq lock held and interrupts off. It must | |
2165 | * be paired with a subsequent finish_task_switch after the context | |
2166 | * switch. | |
2167 | * | |
2168 | * prepare_task_switch sets up locking and calls architecture specific | |
2169 | * hooks. | |
2170 | */ | |
e107be36 AK |
2171 | static inline void |
2172 | prepare_task_switch(struct rq *rq, struct task_struct *prev, | |
2173 | struct task_struct *next) | |
4866cde0 | 2174 | { |
895dd92c | 2175 | trace_sched_switch(prev, next); |
43148951 | 2176 | sched_info_switch(rq, prev, next); |
fe4b04fa | 2177 | perf_event_task_sched_out(prev, next); |
e107be36 | 2178 | fire_sched_out_preempt_notifiers(prev, next); |
4866cde0 NP |
2179 | prepare_lock_switch(rq, next); |
2180 | prepare_arch_switch(next); | |
2181 | } | |
2182 | ||
1da177e4 LT |
2183 | /** |
2184 | * finish_task_switch - clean up after a task-switch | |
344babaa | 2185 | * @rq: runqueue associated with task-switch |
1da177e4 LT |
2186 | * @prev: the thread we just switched away from. |
2187 | * | |
4866cde0 NP |
2188 | * finish_task_switch must be called after the context switch, paired |
2189 | * with a prepare_task_switch call before the context switch. | |
2190 | * finish_task_switch will reconcile locking set up by prepare_task_switch, | |
2191 | * and do any other architecture-specific cleanup actions. | |
1da177e4 LT |
2192 | * |
2193 | * Note that we may have delayed dropping an mm in context_switch(). If | |
41a2d6cf | 2194 | * so, we finish that here outside of the runqueue lock. (Doing it |
1da177e4 LT |
2195 | * with the lock held can cause deadlocks; see schedule() for |
2196 | * details.) | |
2197 | */ | |
a9957449 | 2198 | static void finish_task_switch(struct rq *rq, struct task_struct *prev) |
1da177e4 LT |
2199 | __releases(rq->lock) |
2200 | { | |
1da177e4 | 2201 | struct mm_struct *mm = rq->prev_mm; |
55a101f8 | 2202 | long prev_state; |
1da177e4 LT |
2203 | |
2204 | rq->prev_mm = NULL; | |
2205 | ||
2206 | /* | |
2207 | * A task struct has one reference for the use as "current". | |
c394cc9f | 2208 | * If a task dies, then it sets TASK_DEAD in tsk->state and calls |
55a101f8 ON |
2209 | * schedule one last time. The schedule call will never return, and |
2210 | * the scheduled task must drop that reference. | |
c394cc9f | 2211 | * The test for TASK_DEAD must occur while the runqueue locks are |
1da177e4 LT |
2212 | * still held, otherwise prev could be scheduled on another cpu, die |
2213 | * there before we look at prev->state, and then the reference would | |
2214 | * be dropped twice. | |
2215 | * Manfred Spraul <manfred@colorfullife.com> | |
2216 | */ | |
55a101f8 | 2217 | prev_state = prev->state; |
bf9fae9f | 2218 | vtime_task_switch(prev); |
4866cde0 | 2219 | finish_arch_switch(prev); |
a8d757ef | 2220 | perf_event_task_sched_in(prev, current); |
4866cde0 | 2221 | finish_lock_switch(rq, prev); |
01f23e16 | 2222 | finish_arch_post_lock_switch(); |
e8fa1362 | 2223 | |
e107be36 | 2224 | fire_sched_in_preempt_notifiers(current); |
1da177e4 LT |
2225 | if (mm) |
2226 | mmdrop(mm); | |
c394cc9f | 2227 | if (unlikely(prev_state == TASK_DEAD)) { |
e6c390f2 DF |
2228 | if (prev->sched_class->task_dead) |
2229 | prev->sched_class->task_dead(prev); | |
2230 | ||
c6fd91f0 | 2231 | /* |
2232 | * Remove function-return probe instances associated with this | |
2233 | * task and put them back on the free list. | |
9761eea8 | 2234 | */ |
c6fd91f0 | 2235 | kprobe_flush_task(prev); |
1da177e4 | 2236 | put_task_struct(prev); |
c6fd91f0 | 2237 | } |
99e5ada9 FW |
2238 | |
2239 | tick_nohz_task_switch(current); | |
1da177e4 LT |
2240 | } |
2241 | ||
3f029d3c GH |
2242 | #ifdef CONFIG_SMP |
2243 | ||
3f029d3c GH |
2244 | /* rq->lock is NOT held, but preemption is disabled */ |
2245 | static inline void post_schedule(struct rq *rq) | |
2246 | { | |
2247 | if (rq->post_schedule) { | |
2248 | unsigned long flags; | |
2249 | ||
05fa785c | 2250 | raw_spin_lock_irqsave(&rq->lock, flags); |
3f029d3c GH |
2251 | if (rq->curr->sched_class->post_schedule) |
2252 | rq->curr->sched_class->post_schedule(rq); | |
05fa785c | 2253 | raw_spin_unlock_irqrestore(&rq->lock, flags); |
3f029d3c GH |
2254 | |
2255 | rq->post_schedule = 0; | |
2256 | } | |
2257 | } | |
2258 | ||
2259 | #else | |
da19ab51 | 2260 | |
3f029d3c GH |
2261 | static inline void post_schedule(struct rq *rq) |
2262 | { | |
1da177e4 LT |
2263 | } |
2264 | ||
3f029d3c GH |
2265 | #endif |
2266 | ||
1da177e4 LT |
2267 | /** |
2268 | * schedule_tail - first thing a freshly forked thread must call. | |
2269 | * @prev: the thread we just switched away from. | |
2270 | */ | |
722a9f92 | 2271 | asmlinkage __visible void schedule_tail(struct task_struct *prev) |
1da177e4 LT |
2272 | __releases(rq->lock) |
2273 | { | |
70b97a7f IM |
2274 | struct rq *rq = this_rq(); |
2275 | ||
4866cde0 | 2276 | finish_task_switch(rq, prev); |
da19ab51 | 2277 | |
3f029d3c GH |
2278 | /* |
2279 | * FIXME: do we need to worry about rq being invalidated by the | |
2280 | * task_switch? | |
2281 | */ | |
2282 | post_schedule(rq); | |
70b97a7f | 2283 | |
4866cde0 NP |
2284 | #ifdef __ARCH_WANT_UNLOCKED_CTXSW |
2285 | /* In this case, finish_task_switch does not reenable preemption */ | |
2286 | preempt_enable(); | |
2287 | #endif | |
1da177e4 | 2288 | if (current->set_child_tid) |
b488893a | 2289 | put_user(task_pid_vnr(current), current->set_child_tid); |
1da177e4 LT |
2290 | } |
2291 | ||
2292 | /* | |
2293 | * context_switch - switch to the new MM and the new | |
2294 | * thread's register state. | |
2295 | */ | |
dd41f596 | 2296 | static inline void |
70b97a7f | 2297 | context_switch(struct rq *rq, struct task_struct *prev, |
36c8b586 | 2298 | struct task_struct *next) |
1da177e4 | 2299 | { |
dd41f596 | 2300 | struct mm_struct *mm, *oldmm; |
1da177e4 | 2301 | |
e107be36 | 2302 | prepare_task_switch(rq, prev, next); |
fe4b04fa | 2303 | |
dd41f596 IM |
2304 | mm = next->mm; |
2305 | oldmm = prev->active_mm; | |
9226d125 ZA |
2306 | /* |
2307 | * For paravirt, this is coupled with an exit in switch_to to | |
2308 | * combine the page table reload and the switch backend into | |
2309 | * one hypercall. | |
2310 | */ | |
224101ed | 2311 | arch_start_context_switch(prev); |
9226d125 | 2312 | |
31915ab4 | 2313 | if (!mm) { |
1da177e4 LT |
2314 | next->active_mm = oldmm; |
2315 | atomic_inc(&oldmm->mm_count); | |
2316 | enter_lazy_tlb(oldmm, next); | |
2317 | } else | |
2318 | switch_mm(oldmm, mm, next); | |
2319 | ||
31915ab4 | 2320 | if (!prev->mm) { |
1da177e4 | 2321 | prev->active_mm = NULL; |
1da177e4 LT |
2322 | rq->prev_mm = oldmm; |
2323 | } | |
3a5f5e48 IM |
2324 | /* |
2325 | * Since the runqueue lock will be released by the next | |
2326 | * task (which is an invalid locking op but in the case | |
2327 | * of the scheduler it's an obvious special-case), so we | |
2328 | * do an early lockdep release here: | |
2329 | */ | |
2330 | #ifndef __ARCH_WANT_UNLOCKED_CTXSW | |
8a25d5de | 2331 | spin_release(&rq->lock.dep_map, 1, _THIS_IP_); |
3a5f5e48 | 2332 | #endif |
1da177e4 | 2333 | |
91d1aa43 | 2334 | context_tracking_task_switch(prev, next); |
1da177e4 LT |
2335 | /* Here we just switch the register state and the stack. */ |
2336 | switch_to(prev, next, prev); | |
2337 | ||
dd41f596 IM |
2338 | barrier(); |
2339 | /* | |
2340 | * this_rq must be evaluated again because prev may have moved | |
2341 | * CPUs since it called schedule(), thus the 'rq' on its stack | |
2342 | * frame will be invalid. | |
2343 | */ | |
2344 | finish_task_switch(this_rq(), prev); | |
1da177e4 LT |
2345 | } |
2346 | ||
2347 | /* | |
1c3e8264 | 2348 | * nr_running and nr_context_switches: |
1da177e4 LT |
2349 | * |
2350 | * externally visible scheduler statistics: current number of runnable | |
1c3e8264 | 2351 | * threads, total number of context switches performed since bootup. |
1da177e4 LT |
2352 | */ |
2353 | unsigned long nr_running(void) | |
2354 | { | |
2355 | unsigned long i, sum = 0; | |
2356 | ||
2357 | for_each_online_cpu(i) | |
2358 | sum += cpu_rq(i)->nr_running; | |
2359 | ||
2360 | return sum; | |
f711f609 | 2361 | } |
1da177e4 | 2362 | |
1da177e4 | 2363 | unsigned long long nr_context_switches(void) |
46cb4b7c | 2364 | { |
cc94abfc SR |
2365 | int i; |
2366 | unsigned long long sum = 0; | |
46cb4b7c | 2367 | |
0a945022 | 2368 | for_each_possible_cpu(i) |
1da177e4 | 2369 | sum += cpu_rq(i)->nr_switches; |
46cb4b7c | 2370 | |
1da177e4 LT |
2371 | return sum; |
2372 | } | |
483b4ee6 | 2373 | |
1da177e4 LT |
2374 | unsigned long nr_iowait(void) |
2375 | { | |
2376 | unsigned long i, sum = 0; | |
483b4ee6 | 2377 | |
0a945022 | 2378 | for_each_possible_cpu(i) |
1da177e4 | 2379 | sum += atomic_read(&cpu_rq(i)->nr_iowait); |
46cb4b7c | 2380 | |
1da177e4 LT |
2381 | return sum; |
2382 | } | |
483b4ee6 | 2383 | |
8c215bd3 | 2384 | unsigned long nr_iowait_cpu(int cpu) |
69d25870 | 2385 | { |
8c215bd3 | 2386 | struct rq *this = cpu_rq(cpu); |
69d25870 AV |
2387 | return atomic_read(&this->nr_iowait); |
2388 | } | |
46cb4b7c | 2389 | |
dd41f596 | 2390 | #ifdef CONFIG_SMP |
8a0be9ef | 2391 | |
46cb4b7c | 2392 | /* |
38022906 PZ |
2393 | * sched_exec - execve() is a valuable balancing opportunity, because at |
2394 | * this point the task has the smallest effective memory and cache footprint. | |
46cb4b7c | 2395 | */ |
38022906 | 2396 | void sched_exec(void) |
46cb4b7c | 2397 | { |
38022906 | 2398 | struct task_struct *p = current; |
1da177e4 | 2399 | unsigned long flags; |
0017d735 | 2400 | int dest_cpu; |
46cb4b7c | 2401 | |
8f42ced9 | 2402 | raw_spin_lock_irqsave(&p->pi_lock, flags); |
ac66f547 | 2403 | dest_cpu = p->sched_class->select_task_rq(p, task_cpu(p), SD_BALANCE_EXEC, 0); |
0017d735 PZ |
2404 | if (dest_cpu == smp_processor_id()) |
2405 | goto unlock; | |
38022906 | 2406 | |
8f42ced9 | 2407 | if (likely(cpu_active(dest_cpu))) { |
969c7921 | 2408 | struct migration_arg arg = { p, dest_cpu }; |
46cb4b7c | 2409 | |
8f42ced9 PZ |
2410 | raw_spin_unlock_irqrestore(&p->pi_lock, flags); |
2411 | stop_one_cpu(task_cpu(p), migration_cpu_stop, &arg); | |
1da177e4 LT |
2412 | return; |
2413 | } | |
0017d735 | 2414 | unlock: |
8f42ced9 | 2415 | raw_spin_unlock_irqrestore(&p->pi_lock, flags); |
1da177e4 | 2416 | } |
dd41f596 | 2417 | |
1da177e4 LT |
2418 | #endif |
2419 | ||
1da177e4 | 2420 | DEFINE_PER_CPU(struct kernel_stat, kstat); |
3292beb3 | 2421 | DEFINE_PER_CPU(struct kernel_cpustat, kernel_cpustat); |
1da177e4 LT |
2422 | |
2423 | EXPORT_PER_CPU_SYMBOL(kstat); | |
3292beb3 | 2424 | EXPORT_PER_CPU_SYMBOL(kernel_cpustat); |
1da177e4 LT |
2425 | |
2426 | /* | |
c5f8d995 | 2427 | * Return any ns on the sched_clock that have not yet been accounted in |
f06febc9 | 2428 | * @p in case that task is currently running. |
c5f8d995 HS |
2429 | * |
2430 | * Called with task_rq_lock() held on @rq. | |
1da177e4 | 2431 | */ |
c5f8d995 HS |
2432 | static u64 do_task_delta_exec(struct task_struct *p, struct rq *rq) |
2433 | { | |
2434 | u64 ns = 0; | |
2435 | ||
4036ac15 MG |
2436 | /* |
2437 | * Must be ->curr _and_ ->on_rq. If dequeued, we would | |
2438 | * project cycles that may never be accounted to this | |
2439 | * thread, breaking clock_gettime(). | |
2440 | */ | |
2441 | if (task_current(rq, p) && p->on_rq) { | |
c5f8d995 | 2442 | update_rq_clock(rq); |
78becc27 | 2443 | ns = rq_clock_task(rq) - p->se.exec_start; |
c5f8d995 HS |
2444 | if ((s64)ns < 0) |
2445 | ns = 0; | |
2446 | } | |
2447 | ||
2448 | return ns; | |
2449 | } | |
2450 | ||
bb34d92f | 2451 | unsigned long long task_delta_exec(struct task_struct *p) |
1da177e4 | 2452 | { |
1da177e4 | 2453 | unsigned long flags; |
41b86e9c | 2454 | struct rq *rq; |
bb34d92f | 2455 | u64 ns = 0; |
48f24c4d | 2456 | |
41b86e9c | 2457 | rq = task_rq_lock(p, &flags); |
c5f8d995 | 2458 | ns = do_task_delta_exec(p, rq); |
0122ec5b | 2459 | task_rq_unlock(rq, p, &flags); |
1508487e | 2460 | |
c5f8d995 HS |
2461 | return ns; |
2462 | } | |
f06febc9 | 2463 | |
c5f8d995 HS |
2464 | /* |
2465 | * Return accounted runtime for the task. | |
2466 | * In case the task is currently running, return the runtime plus current's | |
2467 | * pending runtime that have not been accounted yet. | |
2468 | */ | |
2469 | unsigned long long task_sched_runtime(struct task_struct *p) | |
2470 | { | |
2471 | unsigned long flags; | |
2472 | struct rq *rq; | |
2473 | u64 ns = 0; | |
2474 | ||
911b2898 PZ |
2475 | #if defined(CONFIG_64BIT) && defined(CONFIG_SMP) |
2476 | /* | |
2477 | * 64-bit doesn't need locks to atomically read a 64bit value. | |
2478 | * So we have a optimization chance when the task's delta_exec is 0. | |
2479 | * Reading ->on_cpu is racy, but this is ok. | |
2480 | * | |
2481 | * If we race with it leaving cpu, we'll take a lock. So we're correct. | |
2482 | * If we race with it entering cpu, unaccounted time is 0. This is | |
2483 | * indistinguishable from the read occurring a few cycles earlier. | |
4036ac15 MG |
2484 | * If we see ->on_cpu without ->on_rq, the task is leaving, and has |
2485 | * been accounted, so we're correct here as well. | |
911b2898 | 2486 | */ |
4036ac15 | 2487 | if (!p->on_cpu || !p->on_rq) |
911b2898 PZ |
2488 | return p->se.sum_exec_runtime; |
2489 | #endif | |
2490 | ||
c5f8d995 HS |
2491 | rq = task_rq_lock(p, &flags); |
2492 | ns = p->se.sum_exec_runtime + do_task_delta_exec(p, rq); | |
0122ec5b | 2493 | task_rq_unlock(rq, p, &flags); |
c5f8d995 HS |
2494 | |
2495 | return ns; | |
2496 | } | |
48f24c4d | 2497 | |
7835b98b CL |
2498 | /* |
2499 | * This function gets called by the timer code, with HZ frequency. | |
2500 | * We call it with interrupts disabled. | |
7835b98b CL |
2501 | */ |
2502 | void scheduler_tick(void) | |
2503 | { | |
7835b98b CL |
2504 | int cpu = smp_processor_id(); |
2505 | struct rq *rq = cpu_rq(cpu); | |
dd41f596 | 2506 | struct task_struct *curr = rq->curr; |
3e51f33f PZ |
2507 | |
2508 | sched_clock_tick(); | |
dd41f596 | 2509 | |
05fa785c | 2510 | raw_spin_lock(&rq->lock); |
3e51f33f | 2511 | update_rq_clock(rq); |
fa85ae24 | 2512 | curr->sched_class->task_tick(rq, curr, 0); |
83dfd523 | 2513 | update_cpu_load_active(rq); |
05fa785c | 2514 | raw_spin_unlock(&rq->lock); |
7835b98b | 2515 | |
e9d2b064 | 2516 | perf_event_task_tick(); |
e220d2dc | 2517 | |
e418e1c2 | 2518 | #ifdef CONFIG_SMP |
6eb57e0d | 2519 | rq->idle_balance = idle_cpu(cpu); |
7caff66f | 2520 | trigger_load_balance(rq); |
e418e1c2 | 2521 | #endif |
265f22a9 | 2522 | rq_last_tick_reset(rq); |
1da177e4 LT |
2523 | } |
2524 | ||
265f22a9 FW |
2525 | #ifdef CONFIG_NO_HZ_FULL |
2526 | /** | |
2527 | * scheduler_tick_max_deferment | |
2528 | * | |
2529 | * Keep at least one tick per second when a single | |
2530 | * active task is running because the scheduler doesn't | |
2531 | * yet completely support full dynticks environment. | |
2532 | * | |
2533 | * This makes sure that uptime, CFS vruntime, load | |
2534 | * balancing, etc... continue to move forward, even | |
2535 | * with a very low granularity. | |
e69f6186 YB |
2536 | * |
2537 | * Return: Maximum deferment in nanoseconds. | |
265f22a9 FW |
2538 | */ |
2539 | u64 scheduler_tick_max_deferment(void) | |
2540 | { | |
2541 | struct rq *rq = this_rq(); | |
2542 | unsigned long next, now = ACCESS_ONCE(jiffies); | |
2543 | ||
2544 | next = rq->last_sched_tick + HZ; | |
2545 | ||
2546 | if (time_before_eq(next, now)) | |
2547 | return 0; | |
2548 | ||
8fe8ff09 | 2549 | return jiffies_to_nsecs(next - now); |
1da177e4 | 2550 | } |
265f22a9 | 2551 | #endif |
1da177e4 | 2552 | |
132380a0 | 2553 | notrace unsigned long get_parent_ip(unsigned long addr) |
6cd8a4bb SR |
2554 | { |
2555 | if (in_lock_functions(addr)) { | |
2556 | addr = CALLER_ADDR2; | |
2557 | if (in_lock_functions(addr)) | |
2558 | addr = CALLER_ADDR3; | |
2559 | } | |
2560 | return addr; | |
2561 | } | |
1da177e4 | 2562 | |
7e49fcce SR |
2563 | #if defined(CONFIG_PREEMPT) && (defined(CONFIG_DEBUG_PREEMPT) || \ |
2564 | defined(CONFIG_PREEMPT_TRACER)) | |
2565 | ||
edafe3a5 | 2566 | void preempt_count_add(int val) |
1da177e4 | 2567 | { |
6cd8a4bb | 2568 | #ifdef CONFIG_DEBUG_PREEMPT |
1da177e4 LT |
2569 | /* |
2570 | * Underflow? | |
2571 | */ | |
9a11b49a IM |
2572 | if (DEBUG_LOCKS_WARN_ON((preempt_count() < 0))) |
2573 | return; | |
6cd8a4bb | 2574 | #endif |
bdb43806 | 2575 | __preempt_count_add(val); |
6cd8a4bb | 2576 | #ifdef CONFIG_DEBUG_PREEMPT |
1da177e4 LT |
2577 | /* |
2578 | * Spinlock count overflowing soon? | |
2579 | */ | |
33859f7f MOS |
2580 | DEBUG_LOCKS_WARN_ON((preempt_count() & PREEMPT_MASK) >= |
2581 | PREEMPT_MASK - 10); | |
6cd8a4bb | 2582 | #endif |
8f47b187 TG |
2583 | if (preempt_count() == val) { |
2584 | unsigned long ip = get_parent_ip(CALLER_ADDR1); | |
2585 | #ifdef CONFIG_DEBUG_PREEMPT | |
2586 | current->preempt_disable_ip = ip; | |
2587 | #endif | |
2588 | trace_preempt_off(CALLER_ADDR0, ip); | |
2589 | } | |
1da177e4 | 2590 | } |
bdb43806 | 2591 | EXPORT_SYMBOL(preempt_count_add); |
edafe3a5 | 2592 | NOKPROBE_SYMBOL(preempt_count_add); |
1da177e4 | 2593 | |
edafe3a5 | 2594 | void preempt_count_sub(int val) |
1da177e4 | 2595 | { |
6cd8a4bb | 2596 | #ifdef CONFIG_DEBUG_PREEMPT |
1da177e4 LT |
2597 | /* |
2598 | * Underflow? | |
2599 | */ | |
01e3eb82 | 2600 | if (DEBUG_LOCKS_WARN_ON(val > preempt_count())) |
9a11b49a | 2601 | return; |
1da177e4 LT |
2602 | /* |
2603 | * Is the spinlock portion underflowing? | |
2604 | */ | |
9a11b49a IM |
2605 | if (DEBUG_LOCKS_WARN_ON((val < PREEMPT_MASK) && |
2606 | !(preempt_count() & PREEMPT_MASK))) | |
2607 | return; | |
6cd8a4bb | 2608 | #endif |
9a11b49a | 2609 | |
6cd8a4bb SR |
2610 | if (preempt_count() == val) |
2611 | trace_preempt_on(CALLER_ADDR0, get_parent_ip(CALLER_ADDR1)); | |
bdb43806 | 2612 | __preempt_count_sub(val); |
1da177e4 | 2613 | } |
bdb43806 | 2614 | EXPORT_SYMBOL(preempt_count_sub); |
edafe3a5 | 2615 | NOKPROBE_SYMBOL(preempt_count_sub); |
1da177e4 LT |
2616 | |
2617 | #endif | |
2618 | ||
2619 | /* | |
dd41f596 | 2620 | * Print scheduling while atomic bug: |
1da177e4 | 2621 | */ |
dd41f596 | 2622 | static noinline void __schedule_bug(struct task_struct *prev) |
1da177e4 | 2623 | { |
664dfa65 DJ |
2624 | if (oops_in_progress) |
2625 | return; | |
2626 | ||
3df0fc5b PZ |
2627 | printk(KERN_ERR "BUG: scheduling while atomic: %s/%d/0x%08x\n", |
2628 | prev->comm, prev->pid, preempt_count()); | |
838225b4 | 2629 | |
dd41f596 | 2630 | debug_show_held_locks(prev); |
e21f5b15 | 2631 | print_modules(); |
dd41f596 IM |
2632 | if (irqs_disabled()) |
2633 | print_irqtrace_events(prev); | |
8f47b187 TG |
2634 | #ifdef CONFIG_DEBUG_PREEMPT |
2635 | if (in_atomic_preempt_off()) { | |
2636 | pr_err("Preemption disabled at:"); | |
2637 | print_ip_sym(current->preempt_disable_ip); | |
2638 | pr_cont("\n"); | |
2639 | } | |
2640 | #endif | |
6135fc1e | 2641 | dump_stack(); |
373d4d09 | 2642 | add_taint(TAINT_WARN, LOCKDEP_STILL_OK); |
dd41f596 | 2643 | } |
1da177e4 | 2644 | |
dd41f596 IM |
2645 | /* |
2646 | * Various schedule()-time debugging checks and statistics: | |
2647 | */ | |
2648 | static inline void schedule_debug(struct task_struct *prev) | |
2649 | { | |
1da177e4 | 2650 | /* |
41a2d6cf | 2651 | * Test if we are atomic. Since do_exit() needs to call into |
192301e7 ON |
2652 | * schedule() atomically, we ignore that path. Otherwise whine |
2653 | * if we are scheduling when we should not. | |
1da177e4 | 2654 | */ |
192301e7 | 2655 | if (unlikely(in_atomic_preempt_off() && prev->state != TASK_DEAD)) |
dd41f596 | 2656 | __schedule_bug(prev); |
b3fbab05 | 2657 | rcu_sleep_check(); |
dd41f596 | 2658 | |
1da177e4 LT |
2659 | profile_hit(SCHED_PROFILING, __builtin_return_address(0)); |
2660 | ||
2d72376b | 2661 | schedstat_inc(this_rq(), sched_count); |
dd41f596 IM |
2662 | } |
2663 | ||
2664 | /* | |
2665 | * Pick up the highest-prio task: | |
2666 | */ | |
2667 | static inline struct task_struct * | |
606dba2e | 2668 | pick_next_task(struct rq *rq, struct task_struct *prev) |
dd41f596 | 2669 | { |
37e117c0 | 2670 | const struct sched_class *class = &fair_sched_class; |
dd41f596 | 2671 | struct task_struct *p; |
1da177e4 LT |
2672 | |
2673 | /* | |
dd41f596 IM |
2674 | * Optimization: we know that if all tasks are in |
2675 | * the fair class we can call that function directly: | |
1da177e4 | 2676 | */ |
37e117c0 | 2677 | if (likely(prev->sched_class == class && |
38033c37 | 2678 | rq->nr_running == rq->cfs.h_nr_running)) { |
606dba2e | 2679 | p = fair_sched_class.pick_next_task(rq, prev); |
6ccdc84b PZ |
2680 | if (unlikely(p == RETRY_TASK)) |
2681 | goto again; | |
2682 | ||
2683 | /* assumes fair_sched_class->next == idle_sched_class */ | |
2684 | if (unlikely(!p)) | |
2685 | p = idle_sched_class.pick_next_task(rq, prev); | |
2686 | ||
2687 | return p; | |
1da177e4 LT |
2688 | } |
2689 | ||
37e117c0 | 2690 | again: |
34f971f6 | 2691 | for_each_class(class) { |
606dba2e | 2692 | p = class->pick_next_task(rq, prev); |
37e117c0 PZ |
2693 | if (p) { |
2694 | if (unlikely(p == RETRY_TASK)) | |
2695 | goto again; | |
dd41f596 | 2696 | return p; |
37e117c0 | 2697 | } |
dd41f596 | 2698 | } |
34f971f6 PZ |
2699 | |
2700 | BUG(); /* the idle class will always have a runnable task */ | |
dd41f596 | 2701 | } |
1da177e4 | 2702 | |
dd41f596 | 2703 | /* |
c259e01a | 2704 | * __schedule() is the main scheduler function. |
edde96ea PE |
2705 | * |
2706 | * The main means of driving the scheduler and thus entering this function are: | |
2707 | * | |
2708 | * 1. Explicit blocking: mutex, semaphore, waitqueue, etc. | |
2709 | * | |
2710 | * 2. TIF_NEED_RESCHED flag is checked on interrupt and userspace return | |
2711 | * paths. For example, see arch/x86/entry_64.S. | |
2712 | * | |
2713 | * To drive preemption between tasks, the scheduler sets the flag in timer | |
2714 | * interrupt handler scheduler_tick(). | |
2715 | * | |
2716 | * 3. Wakeups don't really cause entry into schedule(). They add a | |
2717 | * task to the run-queue and that's it. | |
2718 | * | |
2719 | * Now, if the new task added to the run-queue preempts the current | |
2720 | * task, then the wakeup sets TIF_NEED_RESCHED and schedule() gets | |
2721 | * called on the nearest possible occasion: | |
2722 | * | |
2723 | * - If the kernel is preemptible (CONFIG_PREEMPT=y): | |
2724 | * | |
2725 | * - in syscall or exception context, at the next outmost | |
2726 | * preempt_enable(). (this might be as soon as the wake_up()'s | |
2727 | * spin_unlock()!) | |
2728 | * | |
2729 | * - in IRQ context, return from interrupt-handler to | |
2730 | * preemptible context | |
2731 | * | |
2732 | * - If the kernel is not preemptible (CONFIG_PREEMPT is not set) | |
2733 | * then at the next: | |
2734 | * | |
2735 | * - cond_resched() call | |
2736 | * - explicit schedule() call | |
2737 | * - return from syscall or exception to user-space | |
2738 | * - return from interrupt-handler to user-space | |
dd41f596 | 2739 | */ |
c259e01a | 2740 | static void __sched __schedule(void) |
dd41f596 IM |
2741 | { |
2742 | struct task_struct *prev, *next; | |
67ca7bde | 2743 | unsigned long *switch_count; |
dd41f596 | 2744 | struct rq *rq; |
31656519 | 2745 | int cpu; |
dd41f596 | 2746 | |
ff743345 PZ |
2747 | need_resched: |
2748 | preempt_disable(); | |
dd41f596 IM |
2749 | cpu = smp_processor_id(); |
2750 | rq = cpu_rq(cpu); | |
25502a6c | 2751 | rcu_note_context_switch(cpu); |
dd41f596 | 2752 | prev = rq->curr; |
dd41f596 | 2753 | |
dd41f596 | 2754 | schedule_debug(prev); |
1da177e4 | 2755 | |
31656519 | 2756 | if (sched_feat(HRTICK)) |
f333fdc9 | 2757 | hrtick_clear(rq); |
8f4d37ec | 2758 | |
e0acd0a6 ON |
2759 | /* |
2760 | * Make sure that signal_pending_state()->signal_pending() below | |
2761 | * can't be reordered with __set_current_state(TASK_INTERRUPTIBLE) | |
2762 | * done by the caller to avoid the race with signal_wake_up(). | |
2763 | */ | |
2764 | smp_mb__before_spinlock(); | |
05fa785c | 2765 | raw_spin_lock_irq(&rq->lock); |
1da177e4 | 2766 | |
246d86b5 | 2767 | switch_count = &prev->nivcsw; |
1da177e4 | 2768 | if (prev->state && !(preempt_count() & PREEMPT_ACTIVE)) { |
21aa9af0 | 2769 | if (unlikely(signal_pending_state(prev->state, prev))) { |
1da177e4 | 2770 | prev->state = TASK_RUNNING; |
21aa9af0 | 2771 | } else { |
2acca55e PZ |
2772 | deactivate_task(rq, prev, DEQUEUE_SLEEP); |
2773 | prev->on_rq = 0; | |
2774 | ||
21aa9af0 | 2775 | /* |
2acca55e PZ |
2776 | * If a worker went to sleep, notify and ask workqueue |
2777 | * whether it wants to wake up a task to maintain | |
2778 | * concurrency. | |
21aa9af0 TH |
2779 | */ |
2780 | if (prev->flags & PF_WQ_WORKER) { | |
2781 | struct task_struct *to_wakeup; | |
2782 | ||
2783 | to_wakeup = wq_worker_sleeping(prev, cpu); | |
2784 | if (to_wakeup) | |
2785 | try_to_wake_up_local(to_wakeup); | |
2786 | } | |
21aa9af0 | 2787 | } |
dd41f596 | 2788 | switch_count = &prev->nvcsw; |
1da177e4 LT |
2789 | } |
2790 | ||
606dba2e PZ |
2791 | if (prev->on_rq || rq->skip_clock_update < 0) |
2792 | update_rq_clock(rq); | |
2793 | ||
2794 | next = pick_next_task(rq, prev); | |
f26f9aff | 2795 | clear_tsk_need_resched(prev); |
f27dde8d | 2796 | clear_preempt_need_resched(); |
f26f9aff | 2797 | rq->skip_clock_update = 0; |
1da177e4 | 2798 | |
1da177e4 | 2799 | if (likely(prev != next)) { |
1da177e4 LT |
2800 | rq->nr_switches++; |
2801 | rq->curr = next; | |
2802 | ++*switch_count; | |
2803 | ||
dd41f596 | 2804 | context_switch(rq, prev, next); /* unlocks the rq */ |
8f4d37ec | 2805 | /* |
246d86b5 ON |
2806 | * The context switch have flipped the stack from under us |
2807 | * and restored the local variables which were saved when | |
2808 | * this task called schedule() in the past. prev == current | |
2809 | * is still correct, but it can be moved to another cpu/rq. | |
8f4d37ec PZ |
2810 | */ |
2811 | cpu = smp_processor_id(); | |
2812 | rq = cpu_rq(cpu); | |
1da177e4 | 2813 | } else |
05fa785c | 2814 | raw_spin_unlock_irq(&rq->lock); |
1da177e4 | 2815 | |
3f029d3c | 2816 | post_schedule(rq); |
1da177e4 | 2817 | |
ba74c144 | 2818 | sched_preempt_enable_no_resched(); |
ff743345 | 2819 | if (need_resched()) |
1da177e4 LT |
2820 | goto need_resched; |
2821 | } | |
c259e01a | 2822 | |
9c40cef2 TG |
2823 | static inline void sched_submit_work(struct task_struct *tsk) |
2824 | { | |
3c7d5184 | 2825 | if (!tsk->state || tsk_is_pi_blocked(tsk)) |
9c40cef2 TG |
2826 | return; |
2827 | /* | |
2828 | * If we are going to sleep and we have plugged IO queued, | |
2829 | * make sure to submit it to avoid deadlocks. | |
2830 | */ | |
2831 | if (blk_needs_flush_plug(tsk)) | |
2832 | blk_schedule_flush_plug(tsk); | |
2833 | } | |
2834 | ||
722a9f92 | 2835 | asmlinkage __visible void __sched schedule(void) |
c259e01a | 2836 | { |
9c40cef2 TG |
2837 | struct task_struct *tsk = current; |
2838 | ||
2839 | sched_submit_work(tsk); | |
c259e01a TG |
2840 | __schedule(); |
2841 | } | |
1da177e4 LT |
2842 | EXPORT_SYMBOL(schedule); |
2843 | ||
91d1aa43 | 2844 | #ifdef CONFIG_CONTEXT_TRACKING |
722a9f92 | 2845 | asmlinkage __visible void __sched schedule_user(void) |
20ab65e3 FW |
2846 | { |
2847 | /* | |
2848 | * If we come here after a random call to set_need_resched(), | |
2849 | * or we have been woken up remotely but the IPI has not yet arrived, | |
2850 | * we haven't yet exited the RCU idle mode. Do it here manually until | |
2851 | * we find a better solution. | |
2852 | */ | |
91d1aa43 | 2853 | user_exit(); |
20ab65e3 | 2854 | schedule(); |
91d1aa43 | 2855 | user_enter(); |
20ab65e3 FW |
2856 | } |
2857 | #endif | |
2858 | ||
c5491ea7 TG |
2859 | /** |
2860 | * schedule_preempt_disabled - called with preemption disabled | |
2861 | * | |
2862 | * Returns with preemption disabled. Note: preempt_count must be 1 | |
2863 | */ | |
2864 | void __sched schedule_preempt_disabled(void) | |
2865 | { | |
ba74c144 | 2866 | sched_preempt_enable_no_resched(); |
c5491ea7 TG |
2867 | schedule(); |
2868 | preempt_disable(); | |
2869 | } | |
2870 | ||
1da177e4 LT |
2871 | #ifdef CONFIG_PREEMPT |
2872 | /* | |
2ed6e34f | 2873 | * this is the entry point to schedule() from in-kernel preemption |
41a2d6cf | 2874 | * off of preempt_enable. Kernel preemptions off return from interrupt |
1da177e4 LT |
2875 | * occur there and call schedule directly. |
2876 | */ | |
722a9f92 | 2877 | asmlinkage __visible void __sched notrace preempt_schedule(void) |
1da177e4 | 2878 | { |
1da177e4 LT |
2879 | /* |
2880 | * If there is a non-zero preempt_count or interrupts are disabled, | |
41a2d6cf | 2881 | * we do not want to preempt the current task. Just return.. |
1da177e4 | 2882 | */ |
fbb00b56 | 2883 | if (likely(!preemptible())) |
1da177e4 LT |
2884 | return; |
2885 | ||
3a5c359a | 2886 | do { |
bdb43806 | 2887 | __preempt_count_add(PREEMPT_ACTIVE); |
c259e01a | 2888 | __schedule(); |
bdb43806 | 2889 | __preempt_count_sub(PREEMPT_ACTIVE); |
1da177e4 | 2890 | |
3a5c359a AK |
2891 | /* |
2892 | * Check again in case we missed a preemption opportunity | |
2893 | * between schedule and now. | |
2894 | */ | |
2895 | barrier(); | |
5ed0cec0 | 2896 | } while (need_resched()); |
1da177e4 | 2897 | } |
376e2424 | 2898 | NOKPROBE_SYMBOL(preempt_schedule); |
1da177e4 | 2899 | EXPORT_SYMBOL(preempt_schedule); |
32e475d7 | 2900 | #endif /* CONFIG_PREEMPT */ |
1da177e4 LT |
2901 | |
2902 | /* | |
2ed6e34f | 2903 | * this is the entry point to schedule() from kernel preemption |
1da177e4 LT |
2904 | * off of irq context. |
2905 | * Note, that this is called and return with irqs disabled. This will | |
2906 | * protect us against recursive calling from irq. | |
2907 | */ | |
722a9f92 | 2908 | asmlinkage __visible void __sched preempt_schedule_irq(void) |
1da177e4 | 2909 | { |
b22366cd | 2910 | enum ctx_state prev_state; |
6478d880 | 2911 | |
2ed6e34f | 2912 | /* Catch callers which need to be fixed */ |
f27dde8d | 2913 | BUG_ON(preempt_count() || !irqs_disabled()); |
1da177e4 | 2914 | |
b22366cd FW |
2915 | prev_state = exception_enter(); |
2916 | ||
3a5c359a | 2917 | do { |
bdb43806 | 2918 | __preempt_count_add(PREEMPT_ACTIVE); |
3a5c359a | 2919 | local_irq_enable(); |
c259e01a | 2920 | __schedule(); |
3a5c359a | 2921 | local_irq_disable(); |
bdb43806 | 2922 | __preempt_count_sub(PREEMPT_ACTIVE); |
1da177e4 | 2923 | |
3a5c359a AK |
2924 | /* |
2925 | * Check again in case we missed a preemption opportunity | |
2926 | * between schedule and now. | |
2927 | */ | |
2928 | barrier(); | |
5ed0cec0 | 2929 | } while (need_resched()); |
b22366cd FW |
2930 | |
2931 | exception_exit(prev_state); | |
1da177e4 LT |
2932 | } |
2933 | ||
63859d4f | 2934 | int default_wake_function(wait_queue_t *curr, unsigned mode, int wake_flags, |
95cdf3b7 | 2935 | void *key) |
1da177e4 | 2936 | { |
63859d4f | 2937 | return try_to_wake_up(curr->private, mode, wake_flags); |
1da177e4 | 2938 | } |
1da177e4 LT |
2939 | EXPORT_SYMBOL(default_wake_function); |
2940 | ||
b29739f9 IM |
2941 | #ifdef CONFIG_RT_MUTEXES |
2942 | ||
2943 | /* | |
2944 | * rt_mutex_setprio - set the current priority of a task | |
2945 | * @p: task | |
2946 | * @prio: prio value (kernel-internal form) | |
2947 | * | |
2948 | * This function changes the 'effective' priority of a task. It does | |
2949 | * not touch ->normal_prio like __setscheduler(). | |
2950 | * | |
c365c292 TG |
2951 | * Used by the rt_mutex code to implement priority inheritance |
2952 | * logic. Call site only calls if the priority of the task changed. | |
b29739f9 | 2953 | */ |
36c8b586 | 2954 | void rt_mutex_setprio(struct task_struct *p, int prio) |
b29739f9 | 2955 | { |
2d3d891d | 2956 | int oldprio, on_rq, running, enqueue_flag = 0; |
70b97a7f | 2957 | struct rq *rq; |
83ab0aa0 | 2958 | const struct sched_class *prev_class; |
b29739f9 | 2959 | |
aab03e05 | 2960 | BUG_ON(prio > MAX_PRIO); |
b29739f9 | 2961 | |
0122ec5b | 2962 | rq = __task_rq_lock(p); |
b29739f9 | 2963 | |
1c4dd99b TG |
2964 | /* |
2965 | * Idle task boosting is a nono in general. There is one | |
2966 | * exception, when PREEMPT_RT and NOHZ is active: | |
2967 | * | |
2968 | * The idle task calls get_next_timer_interrupt() and holds | |
2969 | * the timer wheel base->lock on the CPU and another CPU wants | |
2970 | * to access the timer (probably to cancel it). We can safely | |
2971 | * ignore the boosting request, as the idle CPU runs this code | |
2972 | * with interrupts disabled and will complete the lock | |
2973 | * protected section without being interrupted. So there is no | |
2974 | * real need to boost. | |
2975 | */ | |
2976 | if (unlikely(p == rq->idle)) { | |
2977 | WARN_ON(p != rq->curr); | |
2978 | WARN_ON(p->pi_blocked_on); | |
2979 | goto out_unlock; | |
2980 | } | |
2981 | ||
a8027073 | 2982 | trace_sched_pi_setprio(p, prio); |
2d3d891d | 2983 | p->pi_top_task = rt_mutex_get_top_task(p); |
d5f9f942 | 2984 | oldprio = p->prio; |
83ab0aa0 | 2985 | prev_class = p->sched_class; |
fd2f4419 | 2986 | on_rq = p->on_rq; |
051a1d1a | 2987 | running = task_current(rq, p); |
0e1f3483 | 2988 | if (on_rq) |
69be72c1 | 2989 | dequeue_task(rq, p, 0); |
0e1f3483 HS |
2990 | if (running) |
2991 | p->sched_class->put_prev_task(rq, p); | |
dd41f596 | 2992 | |
2d3d891d DF |
2993 | /* |
2994 | * Boosting condition are: | |
2995 | * 1. -rt task is running and holds mutex A | |
2996 | * --> -dl task blocks on mutex A | |
2997 | * | |
2998 | * 2. -dl task is running and holds mutex A | |
2999 | * --> -dl task blocks on mutex A and could preempt the | |
3000 | * running task | |
3001 | */ | |
3002 | if (dl_prio(prio)) { | |
3003 | if (!dl_prio(p->normal_prio) || (p->pi_top_task && | |
3004 | dl_entity_preempt(&p->pi_top_task->dl, &p->dl))) { | |
3005 | p->dl.dl_boosted = 1; | |
3006 | p->dl.dl_throttled = 0; | |
3007 | enqueue_flag = ENQUEUE_REPLENISH; | |
3008 | } else | |
3009 | p->dl.dl_boosted = 0; | |
aab03e05 | 3010 | p->sched_class = &dl_sched_class; |
2d3d891d DF |
3011 | } else if (rt_prio(prio)) { |
3012 | if (dl_prio(oldprio)) | |
3013 | p->dl.dl_boosted = 0; | |
3014 | if (oldprio < prio) | |
3015 | enqueue_flag = ENQUEUE_HEAD; | |
dd41f596 | 3016 | p->sched_class = &rt_sched_class; |
2d3d891d DF |
3017 | } else { |
3018 | if (dl_prio(oldprio)) | |
3019 | p->dl.dl_boosted = 0; | |
dd41f596 | 3020 | p->sched_class = &fair_sched_class; |
2d3d891d | 3021 | } |
dd41f596 | 3022 | |
b29739f9 IM |
3023 | p->prio = prio; |
3024 | ||
0e1f3483 HS |
3025 | if (running) |
3026 | p->sched_class->set_curr_task(rq); | |
da7a735e | 3027 | if (on_rq) |
2d3d891d | 3028 | enqueue_task(rq, p, enqueue_flag); |
cb469845 | 3029 | |
da7a735e | 3030 | check_class_changed(rq, p, prev_class, oldprio); |
1c4dd99b | 3031 | out_unlock: |
0122ec5b | 3032 | __task_rq_unlock(rq); |
b29739f9 | 3033 | } |
b29739f9 | 3034 | #endif |
d50dde5a | 3035 | |
36c8b586 | 3036 | void set_user_nice(struct task_struct *p, long nice) |
1da177e4 | 3037 | { |
dd41f596 | 3038 | int old_prio, delta, on_rq; |
1da177e4 | 3039 | unsigned long flags; |
70b97a7f | 3040 | struct rq *rq; |
1da177e4 | 3041 | |
75e45d51 | 3042 | if (task_nice(p) == nice || nice < MIN_NICE || nice > MAX_NICE) |
1da177e4 LT |
3043 | return; |
3044 | /* | |
3045 | * We have to be careful, if called from sys_setpriority(), | |
3046 | * the task might be in the middle of scheduling on another CPU. | |
3047 | */ | |
3048 | rq = task_rq_lock(p, &flags); | |
3049 | /* | |
3050 | * The RT priorities are set via sched_setscheduler(), but we still | |
3051 | * allow the 'normal' nice value to be set - but as expected | |
3052 | * it wont have any effect on scheduling until the task is | |
aab03e05 | 3053 | * SCHED_DEADLINE, SCHED_FIFO or SCHED_RR: |
1da177e4 | 3054 | */ |
aab03e05 | 3055 | if (task_has_dl_policy(p) || task_has_rt_policy(p)) { |
1da177e4 LT |
3056 | p->static_prio = NICE_TO_PRIO(nice); |
3057 | goto out_unlock; | |
3058 | } | |
fd2f4419 | 3059 | on_rq = p->on_rq; |
c09595f6 | 3060 | if (on_rq) |
69be72c1 | 3061 | dequeue_task(rq, p, 0); |
1da177e4 | 3062 | |
1da177e4 | 3063 | p->static_prio = NICE_TO_PRIO(nice); |
2dd73a4f | 3064 | set_load_weight(p); |
b29739f9 IM |
3065 | old_prio = p->prio; |
3066 | p->prio = effective_prio(p); | |
3067 | delta = p->prio - old_prio; | |
1da177e4 | 3068 | |
dd41f596 | 3069 | if (on_rq) { |
371fd7e7 | 3070 | enqueue_task(rq, p, 0); |
1da177e4 | 3071 | /* |
d5f9f942 AM |
3072 | * If the task increased its priority or is running and |
3073 | * lowered its priority, then reschedule its CPU: | |
1da177e4 | 3074 | */ |
d5f9f942 | 3075 | if (delta < 0 || (delta > 0 && task_running(rq, p))) |
1da177e4 LT |
3076 | resched_task(rq->curr); |
3077 | } | |
3078 | out_unlock: | |
0122ec5b | 3079 | task_rq_unlock(rq, p, &flags); |
1da177e4 | 3080 | } |
1da177e4 LT |
3081 | EXPORT_SYMBOL(set_user_nice); |
3082 | ||
e43379f1 MM |
3083 | /* |
3084 | * can_nice - check if a task can reduce its nice value | |
3085 | * @p: task | |
3086 | * @nice: nice value | |
3087 | */ | |
36c8b586 | 3088 | int can_nice(const struct task_struct *p, const int nice) |
e43379f1 | 3089 | { |
024f4747 | 3090 | /* convert nice value [19,-20] to rlimit style value [1,40] */ |
7aa2c016 | 3091 | int nice_rlim = nice_to_rlimit(nice); |
48f24c4d | 3092 | |
78d7d407 | 3093 | return (nice_rlim <= task_rlimit(p, RLIMIT_NICE) || |
e43379f1 MM |
3094 | capable(CAP_SYS_NICE)); |
3095 | } | |
3096 | ||
1da177e4 LT |
3097 | #ifdef __ARCH_WANT_SYS_NICE |
3098 | ||
3099 | /* | |
3100 | * sys_nice - change the priority of the current process. | |
3101 | * @increment: priority increment | |
3102 | * | |
3103 | * sys_setpriority is a more generic, but much slower function that | |
3104 | * does similar things. | |
3105 | */ | |
5add95d4 | 3106 | SYSCALL_DEFINE1(nice, int, increment) |
1da177e4 | 3107 | { |
48f24c4d | 3108 | long nice, retval; |
1da177e4 LT |
3109 | |
3110 | /* | |
3111 | * Setpriority might change our priority at the same moment. | |
3112 | * We don't have to worry. Conceptually one call occurs first | |
3113 | * and we have a single winner. | |
3114 | */ | |
a9467fa3 | 3115 | increment = clamp(increment, -NICE_WIDTH, NICE_WIDTH); |
d0ea0268 | 3116 | nice = task_nice(current) + increment; |
1da177e4 | 3117 | |
a9467fa3 | 3118 | nice = clamp_val(nice, MIN_NICE, MAX_NICE); |
e43379f1 MM |
3119 | if (increment < 0 && !can_nice(current, nice)) |
3120 | return -EPERM; | |
3121 | ||
1da177e4 LT |
3122 | retval = security_task_setnice(current, nice); |
3123 | if (retval) | |
3124 | return retval; | |
3125 | ||
3126 | set_user_nice(current, nice); | |
3127 | return 0; | |
3128 | } | |
3129 | ||
3130 | #endif | |
3131 | ||
3132 | /** | |
3133 | * task_prio - return the priority value of a given task. | |
3134 | * @p: the task in question. | |
3135 | * | |
e69f6186 | 3136 | * Return: The priority value as seen by users in /proc. |
1da177e4 LT |
3137 | * RT tasks are offset by -200. Normal tasks are centered |
3138 | * around 0, value goes from -16 to +15. | |
3139 | */ | |
36c8b586 | 3140 | int task_prio(const struct task_struct *p) |
1da177e4 LT |
3141 | { |
3142 | return p->prio - MAX_RT_PRIO; | |
3143 | } | |
3144 | ||
1da177e4 LT |
3145 | /** |
3146 | * idle_cpu - is a given cpu idle currently? | |
3147 | * @cpu: the processor in question. | |
e69f6186 YB |
3148 | * |
3149 | * Return: 1 if the CPU is currently idle. 0 otherwise. | |
1da177e4 LT |
3150 | */ |
3151 | int idle_cpu(int cpu) | |
3152 | { | |
908a3283 TG |
3153 | struct rq *rq = cpu_rq(cpu); |
3154 | ||
3155 | if (rq->curr != rq->idle) | |
3156 | return 0; | |
3157 | ||
3158 | if (rq->nr_running) | |
3159 | return 0; | |
3160 | ||
3161 | #ifdef CONFIG_SMP | |
3162 | if (!llist_empty(&rq->wake_list)) | |
3163 | return 0; | |
3164 | #endif | |
3165 | ||
3166 | return 1; | |
1da177e4 LT |
3167 | } |
3168 | ||
1da177e4 LT |
3169 | /** |
3170 | * idle_task - return the idle task for a given cpu. | |
3171 | * @cpu: the processor in question. | |
e69f6186 YB |
3172 | * |
3173 | * Return: The idle task for the cpu @cpu. | |
1da177e4 | 3174 | */ |
36c8b586 | 3175 | struct task_struct *idle_task(int cpu) |
1da177e4 LT |
3176 | { |
3177 | return cpu_rq(cpu)->idle; | |
3178 | } | |
3179 | ||
3180 | /** | |
3181 | * find_process_by_pid - find a process with a matching PID value. | |
3182 | * @pid: the pid in question. | |
e69f6186 YB |
3183 | * |
3184 | * The task of @pid, if found. %NULL otherwise. | |
1da177e4 | 3185 | */ |
a9957449 | 3186 | static struct task_struct *find_process_by_pid(pid_t pid) |
1da177e4 | 3187 | { |
228ebcbe | 3188 | return pid ? find_task_by_vpid(pid) : current; |
1da177e4 LT |
3189 | } |
3190 | ||
aab03e05 DF |
3191 | /* |
3192 | * This function initializes the sched_dl_entity of a newly becoming | |
3193 | * SCHED_DEADLINE task. | |
3194 | * | |
3195 | * Only the static values are considered here, the actual runtime and the | |
3196 | * absolute deadline will be properly calculated when the task is enqueued | |
3197 | * for the first time with its new policy. | |
3198 | */ | |
3199 | static void | |
3200 | __setparam_dl(struct task_struct *p, const struct sched_attr *attr) | |
3201 | { | |
3202 | struct sched_dl_entity *dl_se = &p->dl; | |
3203 | ||
3204 | init_dl_task_timer(dl_se); | |
3205 | dl_se->dl_runtime = attr->sched_runtime; | |
3206 | dl_se->dl_deadline = attr->sched_deadline; | |
755378a4 | 3207 | dl_se->dl_period = attr->sched_period ?: dl_se->dl_deadline; |
aab03e05 | 3208 | dl_se->flags = attr->sched_flags; |
332ac17e | 3209 | dl_se->dl_bw = to_ratio(dl_se->dl_period, dl_se->dl_runtime); |
aab03e05 DF |
3210 | dl_se->dl_throttled = 0; |
3211 | dl_se->dl_new = 1; | |
5bfd126e | 3212 | dl_se->dl_yielded = 0; |
aab03e05 DF |
3213 | } |
3214 | ||
c365c292 TG |
3215 | static void __setscheduler_params(struct task_struct *p, |
3216 | const struct sched_attr *attr) | |
1da177e4 | 3217 | { |
d50dde5a DF |
3218 | int policy = attr->sched_policy; |
3219 | ||
39fd8fd2 PZ |
3220 | if (policy == -1) /* setparam */ |
3221 | policy = p->policy; | |
3222 | ||
1da177e4 | 3223 | p->policy = policy; |
d50dde5a | 3224 | |
aab03e05 DF |
3225 | if (dl_policy(policy)) |
3226 | __setparam_dl(p, attr); | |
39fd8fd2 | 3227 | else if (fair_policy(policy)) |
d50dde5a DF |
3228 | p->static_prio = NICE_TO_PRIO(attr->sched_nice); |
3229 | ||
39fd8fd2 PZ |
3230 | /* |
3231 | * __sched_setscheduler() ensures attr->sched_priority == 0 when | |
3232 | * !rt_policy. Always setting this ensures that things like | |
3233 | * getparam()/getattr() don't report silly values for !rt tasks. | |
3234 | */ | |
3235 | p->rt_priority = attr->sched_priority; | |
383afd09 | 3236 | p->normal_prio = normal_prio(p); |
c365c292 TG |
3237 | set_load_weight(p); |
3238 | } | |
39fd8fd2 | 3239 | |
c365c292 TG |
3240 | /* Actually do priority change: must hold pi & rq lock. */ |
3241 | static void __setscheduler(struct rq *rq, struct task_struct *p, | |
3242 | const struct sched_attr *attr) | |
3243 | { | |
3244 | __setscheduler_params(p, attr); | |
d50dde5a | 3245 | |
383afd09 SR |
3246 | /* |
3247 | * If we get here, there was no pi waiters boosting the | |
3248 | * task. It is safe to use the normal prio. | |
3249 | */ | |
3250 | p->prio = normal_prio(p); | |
3251 | ||
aab03e05 DF |
3252 | if (dl_prio(p->prio)) |
3253 | p->sched_class = &dl_sched_class; | |
3254 | else if (rt_prio(p->prio)) | |
ffd44db5 PZ |
3255 | p->sched_class = &rt_sched_class; |
3256 | else | |
3257 | p->sched_class = &fair_sched_class; | |
1da177e4 | 3258 | } |
aab03e05 DF |
3259 | |
3260 | static void | |
3261 | __getparam_dl(struct task_struct *p, struct sched_attr *attr) | |
3262 | { | |
3263 | struct sched_dl_entity *dl_se = &p->dl; | |
3264 | ||
3265 | attr->sched_priority = p->rt_priority; | |
3266 | attr->sched_runtime = dl_se->dl_runtime; | |
3267 | attr->sched_deadline = dl_se->dl_deadline; | |
755378a4 | 3268 | attr->sched_period = dl_se->dl_period; |
aab03e05 DF |
3269 | attr->sched_flags = dl_se->flags; |
3270 | } | |
3271 | ||
3272 | /* | |
3273 | * This function validates the new parameters of a -deadline task. | |
3274 | * We ask for the deadline not being zero, and greater or equal | |
755378a4 | 3275 | * than the runtime, as well as the period of being zero or |
332ac17e | 3276 | * greater than deadline. Furthermore, we have to be sure that |
b0827819 JL |
3277 | * user parameters are above the internal resolution of 1us (we |
3278 | * check sched_runtime only since it is always the smaller one) and | |
3279 | * below 2^63 ns (we have to check both sched_deadline and | |
3280 | * sched_period, as the latter can be zero). | |
aab03e05 DF |
3281 | */ |
3282 | static bool | |
3283 | __checkparam_dl(const struct sched_attr *attr) | |
3284 | { | |
b0827819 JL |
3285 | /* deadline != 0 */ |
3286 | if (attr->sched_deadline == 0) | |
3287 | return false; | |
3288 | ||
3289 | /* | |
3290 | * Since we truncate DL_SCALE bits, make sure we're at least | |
3291 | * that big. | |
3292 | */ | |
3293 | if (attr->sched_runtime < (1ULL << DL_SCALE)) | |
3294 | return false; | |
3295 | ||
3296 | /* | |
3297 | * Since we use the MSB for wrap-around and sign issues, make | |
3298 | * sure it's not set (mind that period can be equal to zero). | |
3299 | */ | |
3300 | if (attr->sched_deadline & (1ULL << 63) || | |
3301 | attr->sched_period & (1ULL << 63)) | |
3302 | return false; | |
3303 | ||
3304 | /* runtime <= deadline <= period (if period != 0) */ | |
3305 | if ((attr->sched_period != 0 && | |
3306 | attr->sched_period < attr->sched_deadline) || | |
3307 | attr->sched_deadline < attr->sched_runtime) | |
3308 | return false; | |
3309 | ||
3310 | return true; | |
aab03e05 DF |
3311 | } |
3312 | ||
c69e8d9c DH |
3313 | /* |
3314 | * check the target process has a UID that matches the current process's | |
3315 | */ | |
3316 | static bool check_same_owner(struct task_struct *p) | |
3317 | { | |
3318 | const struct cred *cred = current_cred(), *pcred; | |
3319 | bool match; | |
3320 | ||
3321 | rcu_read_lock(); | |
3322 | pcred = __task_cred(p); | |
9c806aa0 EB |
3323 | match = (uid_eq(cred->euid, pcred->euid) || |
3324 | uid_eq(cred->euid, pcred->uid)); | |
c69e8d9c DH |
3325 | rcu_read_unlock(); |
3326 | return match; | |
3327 | } | |
3328 | ||
d50dde5a DF |
3329 | static int __sched_setscheduler(struct task_struct *p, |
3330 | const struct sched_attr *attr, | |
3331 | bool user) | |
1da177e4 | 3332 | { |
383afd09 SR |
3333 | int newprio = dl_policy(attr->sched_policy) ? MAX_DL_PRIO - 1 : |
3334 | MAX_RT_PRIO - 1 - attr->sched_priority; | |
83b699ed | 3335 | int retval, oldprio, oldpolicy = -1, on_rq, running; |
d50dde5a | 3336 | int policy = attr->sched_policy; |
1da177e4 | 3337 | unsigned long flags; |
83ab0aa0 | 3338 | const struct sched_class *prev_class; |
70b97a7f | 3339 | struct rq *rq; |
ca94c442 | 3340 | int reset_on_fork; |
1da177e4 | 3341 | |
66e5393a SR |
3342 | /* may grab non-irq protected spin_locks */ |
3343 | BUG_ON(in_interrupt()); | |
1da177e4 LT |
3344 | recheck: |
3345 | /* double check policy once rq lock held */ | |
ca94c442 LP |
3346 | if (policy < 0) { |
3347 | reset_on_fork = p->sched_reset_on_fork; | |
1da177e4 | 3348 | policy = oldpolicy = p->policy; |
ca94c442 | 3349 | } else { |
7479f3c9 | 3350 | reset_on_fork = !!(attr->sched_flags & SCHED_FLAG_RESET_ON_FORK); |
ca94c442 | 3351 | |
aab03e05 DF |
3352 | if (policy != SCHED_DEADLINE && |
3353 | policy != SCHED_FIFO && policy != SCHED_RR && | |
ca94c442 LP |
3354 | policy != SCHED_NORMAL && policy != SCHED_BATCH && |
3355 | policy != SCHED_IDLE) | |
3356 | return -EINVAL; | |
3357 | } | |
3358 | ||
7479f3c9 PZ |
3359 | if (attr->sched_flags & ~(SCHED_FLAG_RESET_ON_FORK)) |
3360 | return -EINVAL; | |
3361 | ||
1da177e4 LT |
3362 | /* |
3363 | * Valid priorities for SCHED_FIFO and SCHED_RR are | |
dd41f596 IM |
3364 | * 1..MAX_USER_RT_PRIO-1, valid priority for SCHED_NORMAL, |
3365 | * SCHED_BATCH and SCHED_IDLE is 0. | |
1da177e4 | 3366 | */ |
0bb040a4 | 3367 | if ((p->mm && attr->sched_priority > MAX_USER_RT_PRIO-1) || |
d50dde5a | 3368 | (!p->mm && attr->sched_priority > MAX_RT_PRIO-1)) |
1da177e4 | 3369 | return -EINVAL; |
aab03e05 DF |
3370 | if ((dl_policy(policy) && !__checkparam_dl(attr)) || |
3371 | (rt_policy(policy) != (attr->sched_priority != 0))) | |
1da177e4 LT |
3372 | return -EINVAL; |
3373 | ||
37e4ab3f OC |
3374 | /* |
3375 | * Allow unprivileged RT tasks to decrease priority: | |
3376 | */ | |
961ccddd | 3377 | if (user && !capable(CAP_SYS_NICE)) { |
d50dde5a | 3378 | if (fair_policy(policy)) { |
d0ea0268 | 3379 | if (attr->sched_nice < task_nice(p) && |
eaad4513 | 3380 | !can_nice(p, attr->sched_nice)) |
d50dde5a DF |
3381 | return -EPERM; |
3382 | } | |
3383 | ||
e05606d3 | 3384 | if (rt_policy(policy)) { |
a44702e8 ON |
3385 | unsigned long rlim_rtprio = |
3386 | task_rlimit(p, RLIMIT_RTPRIO); | |
8dc3e909 ON |
3387 | |
3388 | /* can't set/change the rt policy */ | |
3389 | if (policy != p->policy && !rlim_rtprio) | |
3390 | return -EPERM; | |
3391 | ||
3392 | /* can't increase priority */ | |
d50dde5a DF |
3393 | if (attr->sched_priority > p->rt_priority && |
3394 | attr->sched_priority > rlim_rtprio) | |
8dc3e909 ON |
3395 | return -EPERM; |
3396 | } | |
c02aa73b | 3397 | |
d44753b8 JL |
3398 | /* |
3399 | * Can't set/change SCHED_DEADLINE policy at all for now | |
3400 | * (safest behavior); in the future we would like to allow | |
3401 | * unprivileged DL tasks to increase their relative deadline | |
3402 | * or reduce their runtime (both ways reducing utilization) | |
3403 | */ | |
3404 | if (dl_policy(policy)) | |
3405 | return -EPERM; | |
3406 | ||
dd41f596 | 3407 | /* |
c02aa73b DH |
3408 | * Treat SCHED_IDLE as nice 20. Only allow a switch to |
3409 | * SCHED_NORMAL if the RLIMIT_NICE would normally permit it. | |
dd41f596 | 3410 | */ |
c02aa73b | 3411 | if (p->policy == SCHED_IDLE && policy != SCHED_IDLE) { |
d0ea0268 | 3412 | if (!can_nice(p, task_nice(p))) |
c02aa73b DH |
3413 | return -EPERM; |
3414 | } | |
5fe1d75f | 3415 | |
37e4ab3f | 3416 | /* can't change other user's priorities */ |
c69e8d9c | 3417 | if (!check_same_owner(p)) |
37e4ab3f | 3418 | return -EPERM; |
ca94c442 LP |
3419 | |
3420 | /* Normal users shall not reset the sched_reset_on_fork flag */ | |
3421 | if (p->sched_reset_on_fork && !reset_on_fork) | |
3422 | return -EPERM; | |
37e4ab3f | 3423 | } |
1da177e4 | 3424 | |
725aad24 | 3425 | if (user) { |
b0ae1981 | 3426 | retval = security_task_setscheduler(p); |
725aad24 JF |
3427 | if (retval) |
3428 | return retval; | |
3429 | } | |
3430 | ||
b29739f9 IM |
3431 | /* |
3432 | * make sure no PI-waiters arrive (or leave) while we are | |
3433 | * changing the priority of the task: | |
0122ec5b | 3434 | * |
25985edc | 3435 | * To be able to change p->policy safely, the appropriate |
1da177e4 LT |
3436 | * runqueue lock must be held. |
3437 | */ | |
0122ec5b | 3438 | rq = task_rq_lock(p, &flags); |
dc61b1d6 | 3439 | |
34f971f6 PZ |
3440 | /* |
3441 | * Changing the policy of the stop threads its a very bad idea | |
3442 | */ | |
3443 | if (p == rq->stop) { | |
0122ec5b | 3444 | task_rq_unlock(rq, p, &flags); |
34f971f6 PZ |
3445 | return -EINVAL; |
3446 | } | |
3447 | ||
a51e9198 | 3448 | /* |
d6b1e911 TG |
3449 | * If not changing anything there's no need to proceed further, |
3450 | * but store a possible modification of reset_on_fork. | |
a51e9198 | 3451 | */ |
d50dde5a | 3452 | if (unlikely(policy == p->policy)) { |
d0ea0268 | 3453 | if (fair_policy(policy) && attr->sched_nice != task_nice(p)) |
d50dde5a DF |
3454 | goto change; |
3455 | if (rt_policy(policy) && attr->sched_priority != p->rt_priority) | |
3456 | goto change; | |
aab03e05 DF |
3457 | if (dl_policy(policy)) |
3458 | goto change; | |
d50dde5a | 3459 | |
d6b1e911 | 3460 | p->sched_reset_on_fork = reset_on_fork; |
45afb173 | 3461 | task_rq_unlock(rq, p, &flags); |
a51e9198 DF |
3462 | return 0; |
3463 | } | |
d50dde5a | 3464 | change: |
a51e9198 | 3465 | |
dc61b1d6 | 3466 | if (user) { |
332ac17e | 3467 | #ifdef CONFIG_RT_GROUP_SCHED |
dc61b1d6 PZ |
3468 | /* |
3469 | * Do not allow realtime tasks into groups that have no runtime | |
3470 | * assigned. | |
3471 | */ | |
3472 | if (rt_bandwidth_enabled() && rt_policy(policy) && | |
f4493771 MG |
3473 | task_group(p)->rt_bandwidth.rt_runtime == 0 && |
3474 | !task_group_is_autogroup(task_group(p))) { | |
0122ec5b | 3475 | task_rq_unlock(rq, p, &flags); |
dc61b1d6 PZ |
3476 | return -EPERM; |
3477 | } | |
dc61b1d6 | 3478 | #endif |
332ac17e DF |
3479 | #ifdef CONFIG_SMP |
3480 | if (dl_bandwidth_enabled() && dl_policy(policy)) { | |
3481 | cpumask_t *span = rq->rd->span; | |
332ac17e DF |
3482 | |
3483 | /* | |
3484 | * Don't allow tasks with an affinity mask smaller than | |
3485 | * the entire root_domain to become SCHED_DEADLINE. We | |
3486 | * will also fail if there's no bandwidth available. | |
3487 | */ | |
e4099a5e PZ |
3488 | if (!cpumask_subset(span, &p->cpus_allowed) || |
3489 | rq->rd->dl_bw.bw == 0) { | |
332ac17e DF |
3490 | task_rq_unlock(rq, p, &flags); |
3491 | return -EPERM; | |
3492 | } | |
3493 | } | |
3494 | #endif | |
3495 | } | |
dc61b1d6 | 3496 | |
1da177e4 LT |
3497 | /* recheck policy now with rq lock held */ |
3498 | if (unlikely(oldpolicy != -1 && oldpolicy != p->policy)) { | |
3499 | policy = oldpolicy = -1; | |
0122ec5b | 3500 | task_rq_unlock(rq, p, &flags); |
1da177e4 LT |
3501 | goto recheck; |
3502 | } | |
332ac17e DF |
3503 | |
3504 | /* | |
3505 | * If setscheduling to SCHED_DEADLINE (or changing the parameters | |
3506 | * of a SCHED_DEADLINE task) we need to check if enough bandwidth | |
3507 | * is available. | |
3508 | */ | |
e4099a5e | 3509 | if ((dl_policy(policy) || dl_task(p)) && dl_overflow(p, policy, attr)) { |
332ac17e DF |
3510 | task_rq_unlock(rq, p, &flags); |
3511 | return -EBUSY; | |
3512 | } | |
3513 | ||
c365c292 TG |
3514 | p->sched_reset_on_fork = reset_on_fork; |
3515 | oldprio = p->prio; | |
3516 | ||
3517 | /* | |
3518 | * Special case for priority boosted tasks. | |
3519 | * | |
3520 | * If the new priority is lower or equal (user space view) | |
3521 | * than the current (boosted) priority, we just store the new | |
3522 | * normal parameters and do not touch the scheduler class and | |
3523 | * the runqueue. This will be done when the task deboost | |
3524 | * itself. | |
3525 | */ | |
3526 | if (rt_mutex_check_prio(p, newprio)) { | |
3527 | __setscheduler_params(p, attr); | |
3528 | task_rq_unlock(rq, p, &flags); | |
3529 | return 0; | |
3530 | } | |
3531 | ||
fd2f4419 | 3532 | on_rq = p->on_rq; |
051a1d1a | 3533 | running = task_current(rq, p); |
0e1f3483 | 3534 | if (on_rq) |
4ca9b72b | 3535 | dequeue_task(rq, p, 0); |
0e1f3483 HS |
3536 | if (running) |
3537 | p->sched_class->put_prev_task(rq, p); | |
f6b53205 | 3538 | |
83ab0aa0 | 3539 | prev_class = p->sched_class; |
d50dde5a | 3540 | __setscheduler(rq, p, attr); |
f6b53205 | 3541 | |
0e1f3483 HS |
3542 | if (running) |
3543 | p->sched_class->set_curr_task(rq); | |
81a44c54 TG |
3544 | if (on_rq) { |
3545 | /* | |
3546 | * We enqueue to tail when the priority of a task is | |
3547 | * increased (user space view). | |
3548 | */ | |
3549 | enqueue_task(rq, p, oldprio <= p->prio ? ENQUEUE_HEAD : 0); | |
3550 | } | |
cb469845 | 3551 | |
da7a735e | 3552 | check_class_changed(rq, p, prev_class, oldprio); |
0122ec5b | 3553 | task_rq_unlock(rq, p, &flags); |
b29739f9 | 3554 | |
95e02ca9 TG |
3555 | rt_mutex_adjust_pi(p); |
3556 | ||
1da177e4 LT |
3557 | return 0; |
3558 | } | |
961ccddd | 3559 | |
7479f3c9 PZ |
3560 | static int _sched_setscheduler(struct task_struct *p, int policy, |
3561 | const struct sched_param *param, bool check) | |
3562 | { | |
3563 | struct sched_attr attr = { | |
3564 | .sched_policy = policy, | |
3565 | .sched_priority = param->sched_priority, | |
3566 | .sched_nice = PRIO_TO_NICE(p->static_prio), | |
3567 | }; | |
3568 | ||
3569 | /* | |
3570 | * Fixup the legacy SCHED_RESET_ON_FORK hack | |
3571 | */ | |
3572 | if (policy & SCHED_RESET_ON_FORK) { | |
3573 | attr.sched_flags |= SCHED_FLAG_RESET_ON_FORK; | |
3574 | policy &= ~SCHED_RESET_ON_FORK; | |
3575 | attr.sched_policy = policy; | |
3576 | } | |
3577 | ||
3578 | return __sched_setscheduler(p, &attr, check); | |
3579 | } | |
961ccddd RR |
3580 | /** |
3581 | * sched_setscheduler - change the scheduling policy and/or RT priority of a thread. | |
3582 | * @p: the task in question. | |
3583 | * @policy: new policy. | |
3584 | * @param: structure containing the new RT priority. | |
3585 | * | |
e69f6186 YB |
3586 | * Return: 0 on success. An error code otherwise. |
3587 | * | |
961ccddd RR |
3588 | * NOTE that the task may be already dead. |
3589 | */ | |
3590 | int sched_setscheduler(struct task_struct *p, int policy, | |
fe7de49f | 3591 | const struct sched_param *param) |
961ccddd | 3592 | { |
7479f3c9 | 3593 | return _sched_setscheduler(p, policy, param, true); |
961ccddd | 3594 | } |
1da177e4 LT |
3595 | EXPORT_SYMBOL_GPL(sched_setscheduler); |
3596 | ||
d50dde5a DF |
3597 | int sched_setattr(struct task_struct *p, const struct sched_attr *attr) |
3598 | { | |
3599 | return __sched_setscheduler(p, attr, true); | |
3600 | } | |
3601 | EXPORT_SYMBOL_GPL(sched_setattr); | |
3602 | ||
961ccddd RR |
3603 | /** |
3604 | * sched_setscheduler_nocheck - change the scheduling policy and/or RT priority of a thread from kernelspace. | |
3605 | * @p: the task in question. | |
3606 | * @policy: new policy. | |
3607 | * @param: structure containing the new RT priority. | |
3608 | * | |
3609 | * Just like sched_setscheduler, only don't bother checking if the | |
3610 | * current context has permission. For example, this is needed in | |
3611 | * stop_machine(): we create temporary high priority worker threads, | |
3612 | * but our caller might not have that capability. | |
e69f6186 YB |
3613 | * |
3614 | * Return: 0 on success. An error code otherwise. | |
961ccddd RR |
3615 | */ |
3616 | int sched_setscheduler_nocheck(struct task_struct *p, int policy, | |
fe7de49f | 3617 | const struct sched_param *param) |
961ccddd | 3618 | { |
7479f3c9 | 3619 | return _sched_setscheduler(p, policy, param, false); |
961ccddd RR |
3620 | } |
3621 | ||
95cdf3b7 IM |
3622 | static int |
3623 | do_sched_setscheduler(pid_t pid, int policy, struct sched_param __user *param) | |
1da177e4 | 3624 | { |
1da177e4 LT |
3625 | struct sched_param lparam; |
3626 | struct task_struct *p; | |
36c8b586 | 3627 | int retval; |
1da177e4 LT |
3628 | |
3629 | if (!param || pid < 0) | |
3630 | return -EINVAL; | |
3631 | if (copy_from_user(&lparam, param, sizeof(struct sched_param))) | |
3632 | return -EFAULT; | |
5fe1d75f ON |
3633 | |
3634 | rcu_read_lock(); | |
3635 | retval = -ESRCH; | |
1da177e4 | 3636 | p = find_process_by_pid(pid); |
5fe1d75f ON |
3637 | if (p != NULL) |
3638 | retval = sched_setscheduler(p, policy, &lparam); | |
3639 | rcu_read_unlock(); | |
36c8b586 | 3640 | |
1da177e4 LT |
3641 | return retval; |
3642 | } | |
3643 | ||
d50dde5a DF |
3644 | /* |
3645 | * Mimics kernel/events/core.c perf_copy_attr(). | |
3646 | */ | |
3647 | static int sched_copy_attr(struct sched_attr __user *uattr, | |
3648 | struct sched_attr *attr) | |
3649 | { | |
3650 | u32 size; | |
3651 | int ret; | |
3652 | ||
3653 | if (!access_ok(VERIFY_WRITE, uattr, SCHED_ATTR_SIZE_VER0)) | |
3654 | return -EFAULT; | |
3655 | ||
3656 | /* | |
3657 | * zero the full structure, so that a short copy will be nice. | |
3658 | */ | |
3659 | memset(attr, 0, sizeof(*attr)); | |
3660 | ||
3661 | ret = get_user(size, &uattr->size); | |
3662 | if (ret) | |
3663 | return ret; | |
3664 | ||
3665 | if (size > PAGE_SIZE) /* silly large */ | |
3666 | goto err_size; | |
3667 | ||
3668 | if (!size) /* abi compat */ | |
3669 | size = SCHED_ATTR_SIZE_VER0; | |
3670 | ||
3671 | if (size < SCHED_ATTR_SIZE_VER0) | |
3672 | goto err_size; | |
3673 | ||
3674 | /* | |
3675 | * If we're handed a bigger struct than we know of, | |
3676 | * ensure all the unknown bits are 0 - i.e. new | |
3677 | * user-space does not rely on any kernel feature | |
3678 | * extensions we dont know about yet. | |
3679 | */ | |
3680 | if (size > sizeof(*attr)) { | |
3681 | unsigned char __user *addr; | |
3682 | unsigned char __user *end; | |
3683 | unsigned char val; | |
3684 | ||
3685 | addr = (void __user *)uattr + sizeof(*attr); | |
3686 | end = (void __user *)uattr + size; | |
3687 | ||
3688 | for (; addr < end; addr++) { | |
3689 | ret = get_user(val, addr); | |
3690 | if (ret) | |
3691 | return ret; | |
3692 | if (val) | |
3693 | goto err_size; | |
3694 | } | |
3695 | size = sizeof(*attr); | |
3696 | } | |
3697 | ||
3698 | ret = copy_from_user(attr, uattr, size); | |
3699 | if (ret) | |
3700 | return -EFAULT; | |
3701 | ||
3702 | /* | |
3703 | * XXX: do we want to be lenient like existing syscalls; or do we want | |
3704 | * to be strict and return an error on out-of-bounds values? | |
3705 | */ | |
75e45d51 | 3706 | attr->sched_nice = clamp(attr->sched_nice, MIN_NICE, MAX_NICE); |
d50dde5a | 3707 | |
e78c7bca | 3708 | return 0; |
d50dde5a DF |
3709 | |
3710 | err_size: | |
3711 | put_user(sizeof(*attr), &uattr->size); | |
e78c7bca | 3712 | return -E2BIG; |
d50dde5a DF |
3713 | } |
3714 | ||
1da177e4 LT |
3715 | /** |
3716 | * sys_sched_setscheduler - set/change the scheduler policy and RT priority | |
3717 | * @pid: the pid in question. | |
3718 | * @policy: new policy. | |
3719 | * @param: structure containing the new RT priority. | |
e69f6186 YB |
3720 | * |
3721 | * Return: 0 on success. An error code otherwise. | |
1da177e4 | 3722 | */ |
5add95d4 HC |
3723 | SYSCALL_DEFINE3(sched_setscheduler, pid_t, pid, int, policy, |
3724 | struct sched_param __user *, param) | |
1da177e4 | 3725 | { |
c21761f1 JB |
3726 | /* negative values for policy are not valid */ |
3727 | if (policy < 0) | |
3728 | return -EINVAL; | |
3729 | ||
1da177e4 LT |
3730 | return do_sched_setscheduler(pid, policy, param); |
3731 | } | |
3732 | ||
3733 | /** | |
3734 | * sys_sched_setparam - set/change the RT priority of a thread | |
3735 | * @pid: the pid in question. | |
3736 | * @param: structure containing the new RT priority. | |
e69f6186 YB |
3737 | * |
3738 | * Return: 0 on success. An error code otherwise. | |
1da177e4 | 3739 | */ |
5add95d4 | 3740 | SYSCALL_DEFINE2(sched_setparam, pid_t, pid, struct sched_param __user *, param) |
1da177e4 LT |
3741 | { |
3742 | return do_sched_setscheduler(pid, -1, param); | |
3743 | } | |
3744 | ||
d50dde5a DF |
3745 | /** |
3746 | * sys_sched_setattr - same as above, but with extended sched_attr | |
3747 | * @pid: the pid in question. | |
5778fccf | 3748 | * @uattr: structure containing the extended parameters. |
db66d756 | 3749 | * @flags: for future extension. |
d50dde5a | 3750 | */ |
6d35ab48 PZ |
3751 | SYSCALL_DEFINE3(sched_setattr, pid_t, pid, struct sched_attr __user *, uattr, |
3752 | unsigned int, flags) | |
d50dde5a DF |
3753 | { |
3754 | struct sched_attr attr; | |
3755 | struct task_struct *p; | |
3756 | int retval; | |
3757 | ||
6d35ab48 | 3758 | if (!uattr || pid < 0 || flags) |
d50dde5a DF |
3759 | return -EINVAL; |
3760 | ||
143cf23d MK |
3761 | retval = sched_copy_attr(uattr, &attr); |
3762 | if (retval) | |
3763 | return retval; | |
d50dde5a | 3764 | |
b14ed2c2 | 3765 | if ((int)attr.sched_policy < 0) |
dbdb2275 | 3766 | return -EINVAL; |
d50dde5a DF |
3767 | |
3768 | rcu_read_lock(); | |
3769 | retval = -ESRCH; | |
3770 | p = find_process_by_pid(pid); | |
3771 | if (p != NULL) | |
3772 | retval = sched_setattr(p, &attr); | |
3773 | rcu_read_unlock(); | |
3774 | ||
3775 | return retval; | |
3776 | } | |
3777 | ||
1da177e4 LT |
3778 | /** |
3779 | * sys_sched_getscheduler - get the policy (scheduling class) of a thread | |
3780 | * @pid: the pid in question. | |
e69f6186 YB |
3781 | * |
3782 | * Return: On success, the policy of the thread. Otherwise, a negative error | |
3783 | * code. | |
1da177e4 | 3784 | */ |
5add95d4 | 3785 | SYSCALL_DEFINE1(sched_getscheduler, pid_t, pid) |
1da177e4 | 3786 | { |
36c8b586 | 3787 | struct task_struct *p; |
3a5c359a | 3788 | int retval; |
1da177e4 LT |
3789 | |
3790 | if (pid < 0) | |
3a5c359a | 3791 | return -EINVAL; |
1da177e4 LT |
3792 | |
3793 | retval = -ESRCH; | |
5fe85be0 | 3794 | rcu_read_lock(); |
1da177e4 LT |
3795 | p = find_process_by_pid(pid); |
3796 | if (p) { | |
3797 | retval = security_task_getscheduler(p); | |
3798 | if (!retval) | |
ca94c442 LP |
3799 | retval = p->policy |
3800 | | (p->sched_reset_on_fork ? SCHED_RESET_ON_FORK : 0); | |
1da177e4 | 3801 | } |
5fe85be0 | 3802 | rcu_read_unlock(); |
1da177e4 LT |
3803 | return retval; |
3804 | } | |
3805 | ||
3806 | /** | |
ca94c442 | 3807 | * sys_sched_getparam - get the RT priority of a thread |
1da177e4 LT |
3808 | * @pid: the pid in question. |
3809 | * @param: structure containing the RT priority. | |
e69f6186 YB |
3810 | * |
3811 | * Return: On success, 0 and the RT priority is in @param. Otherwise, an error | |
3812 | * code. | |
1da177e4 | 3813 | */ |
5add95d4 | 3814 | SYSCALL_DEFINE2(sched_getparam, pid_t, pid, struct sched_param __user *, param) |
1da177e4 | 3815 | { |
ce5f7f82 | 3816 | struct sched_param lp = { .sched_priority = 0 }; |
36c8b586 | 3817 | struct task_struct *p; |
3a5c359a | 3818 | int retval; |
1da177e4 LT |
3819 | |
3820 | if (!param || pid < 0) | |
3a5c359a | 3821 | return -EINVAL; |
1da177e4 | 3822 | |
5fe85be0 | 3823 | rcu_read_lock(); |
1da177e4 LT |
3824 | p = find_process_by_pid(pid); |
3825 | retval = -ESRCH; | |
3826 | if (!p) | |
3827 | goto out_unlock; | |
3828 | ||
3829 | retval = security_task_getscheduler(p); | |
3830 | if (retval) | |
3831 | goto out_unlock; | |
3832 | ||
ce5f7f82 PZ |
3833 | if (task_has_rt_policy(p)) |
3834 | lp.sched_priority = p->rt_priority; | |
5fe85be0 | 3835 | rcu_read_unlock(); |
1da177e4 LT |
3836 | |
3837 | /* | |
3838 | * This one might sleep, we cannot do it with a spinlock held ... | |
3839 | */ | |
3840 | retval = copy_to_user(param, &lp, sizeof(*param)) ? -EFAULT : 0; | |
3841 | ||
1da177e4 LT |
3842 | return retval; |
3843 | ||
3844 | out_unlock: | |
5fe85be0 | 3845 | rcu_read_unlock(); |
1da177e4 LT |
3846 | return retval; |
3847 | } | |
3848 | ||
d50dde5a DF |
3849 | static int sched_read_attr(struct sched_attr __user *uattr, |
3850 | struct sched_attr *attr, | |
3851 | unsigned int usize) | |
3852 | { | |
3853 | int ret; | |
3854 | ||
3855 | if (!access_ok(VERIFY_WRITE, uattr, usize)) | |
3856 | return -EFAULT; | |
3857 | ||
3858 | /* | |
3859 | * If we're handed a smaller struct than we know of, | |
3860 | * ensure all the unknown bits are 0 - i.e. old | |
3861 | * user-space does not get uncomplete information. | |
3862 | */ | |
3863 | if (usize < sizeof(*attr)) { | |
3864 | unsigned char *addr; | |
3865 | unsigned char *end; | |
3866 | ||
3867 | addr = (void *)attr + usize; | |
3868 | end = (void *)attr + sizeof(*attr); | |
3869 | ||
3870 | for (; addr < end; addr++) { | |
3871 | if (*addr) | |
22400674 | 3872 | return -EFBIG; |
d50dde5a DF |
3873 | } |
3874 | ||
3875 | attr->size = usize; | |
3876 | } | |
3877 | ||
4efbc454 | 3878 | ret = copy_to_user(uattr, attr, attr->size); |
d50dde5a DF |
3879 | if (ret) |
3880 | return -EFAULT; | |
3881 | ||
22400674 | 3882 | return 0; |
d50dde5a DF |
3883 | } |
3884 | ||
3885 | /** | |
aab03e05 | 3886 | * sys_sched_getattr - similar to sched_getparam, but with sched_attr |
d50dde5a | 3887 | * @pid: the pid in question. |
5778fccf | 3888 | * @uattr: structure containing the extended parameters. |
d50dde5a | 3889 | * @size: sizeof(attr) for fwd/bwd comp. |
db66d756 | 3890 | * @flags: for future extension. |
d50dde5a | 3891 | */ |
6d35ab48 PZ |
3892 | SYSCALL_DEFINE4(sched_getattr, pid_t, pid, struct sched_attr __user *, uattr, |
3893 | unsigned int, size, unsigned int, flags) | |
d50dde5a DF |
3894 | { |
3895 | struct sched_attr attr = { | |
3896 | .size = sizeof(struct sched_attr), | |
3897 | }; | |
3898 | struct task_struct *p; | |
3899 | int retval; | |
3900 | ||
3901 | if (!uattr || pid < 0 || size > PAGE_SIZE || | |
6d35ab48 | 3902 | size < SCHED_ATTR_SIZE_VER0 || flags) |
d50dde5a DF |
3903 | return -EINVAL; |
3904 | ||
3905 | rcu_read_lock(); | |
3906 | p = find_process_by_pid(pid); | |
3907 | retval = -ESRCH; | |
3908 | if (!p) | |
3909 | goto out_unlock; | |
3910 | ||
3911 | retval = security_task_getscheduler(p); | |
3912 | if (retval) | |
3913 | goto out_unlock; | |
3914 | ||
3915 | attr.sched_policy = p->policy; | |
7479f3c9 PZ |
3916 | if (p->sched_reset_on_fork) |
3917 | attr.sched_flags |= SCHED_FLAG_RESET_ON_FORK; | |
aab03e05 DF |
3918 | if (task_has_dl_policy(p)) |
3919 | __getparam_dl(p, &attr); | |
3920 | else if (task_has_rt_policy(p)) | |
d50dde5a DF |
3921 | attr.sched_priority = p->rt_priority; |
3922 | else | |
d0ea0268 | 3923 | attr.sched_nice = task_nice(p); |
d50dde5a DF |
3924 | |
3925 | rcu_read_unlock(); | |
3926 | ||
3927 | retval = sched_read_attr(uattr, &attr, size); | |
3928 | return retval; | |
3929 | ||
3930 | out_unlock: | |
3931 | rcu_read_unlock(); | |
3932 | return retval; | |
3933 | } | |
3934 | ||
96f874e2 | 3935 | long sched_setaffinity(pid_t pid, const struct cpumask *in_mask) |
1da177e4 | 3936 | { |
5a16f3d3 | 3937 | cpumask_var_t cpus_allowed, new_mask; |
36c8b586 IM |
3938 | struct task_struct *p; |
3939 | int retval; | |
1da177e4 | 3940 | |
23f5d142 | 3941 | rcu_read_lock(); |
1da177e4 LT |
3942 | |
3943 | p = find_process_by_pid(pid); | |
3944 | if (!p) { | |
23f5d142 | 3945 | rcu_read_unlock(); |
1da177e4 LT |
3946 | return -ESRCH; |
3947 | } | |
3948 | ||
23f5d142 | 3949 | /* Prevent p going away */ |
1da177e4 | 3950 | get_task_struct(p); |
23f5d142 | 3951 | rcu_read_unlock(); |
1da177e4 | 3952 | |
14a40ffc TH |
3953 | if (p->flags & PF_NO_SETAFFINITY) { |
3954 | retval = -EINVAL; | |
3955 | goto out_put_task; | |
3956 | } | |
5a16f3d3 RR |
3957 | if (!alloc_cpumask_var(&cpus_allowed, GFP_KERNEL)) { |
3958 | retval = -ENOMEM; | |
3959 | goto out_put_task; | |
3960 | } | |
3961 | if (!alloc_cpumask_var(&new_mask, GFP_KERNEL)) { | |
3962 | retval = -ENOMEM; | |
3963 | goto out_free_cpus_allowed; | |
3964 | } | |
1da177e4 | 3965 | retval = -EPERM; |
4c44aaaf EB |
3966 | if (!check_same_owner(p)) { |
3967 | rcu_read_lock(); | |
3968 | if (!ns_capable(__task_cred(p)->user_ns, CAP_SYS_NICE)) { | |
3969 | rcu_read_unlock(); | |
3970 | goto out_unlock; | |
3971 | } | |
3972 | rcu_read_unlock(); | |
3973 | } | |
1da177e4 | 3974 | |
b0ae1981 | 3975 | retval = security_task_setscheduler(p); |
e7834f8f DQ |
3976 | if (retval) |
3977 | goto out_unlock; | |
3978 | ||
e4099a5e PZ |
3979 | |
3980 | cpuset_cpus_allowed(p, cpus_allowed); | |
3981 | cpumask_and(new_mask, in_mask, cpus_allowed); | |
3982 | ||
332ac17e DF |
3983 | /* |
3984 | * Since bandwidth control happens on root_domain basis, | |
3985 | * if admission test is enabled, we only admit -deadline | |
3986 | * tasks allowed to run on all the CPUs in the task's | |
3987 | * root_domain. | |
3988 | */ | |
3989 | #ifdef CONFIG_SMP | |
3990 | if (task_has_dl_policy(p)) { | |
3991 | const struct cpumask *span = task_rq(p)->rd->span; | |
3992 | ||
e4099a5e | 3993 | if (dl_bandwidth_enabled() && !cpumask_subset(span, new_mask)) { |
332ac17e DF |
3994 | retval = -EBUSY; |
3995 | goto out_unlock; | |
3996 | } | |
3997 | } | |
3998 | #endif | |
49246274 | 3999 | again: |
5a16f3d3 | 4000 | retval = set_cpus_allowed_ptr(p, new_mask); |
1da177e4 | 4001 | |
8707d8b8 | 4002 | if (!retval) { |
5a16f3d3 RR |
4003 | cpuset_cpus_allowed(p, cpus_allowed); |
4004 | if (!cpumask_subset(new_mask, cpus_allowed)) { | |
8707d8b8 PM |
4005 | /* |
4006 | * We must have raced with a concurrent cpuset | |
4007 | * update. Just reset the cpus_allowed to the | |
4008 | * cpuset's cpus_allowed | |
4009 | */ | |
5a16f3d3 | 4010 | cpumask_copy(new_mask, cpus_allowed); |
8707d8b8 PM |
4011 | goto again; |
4012 | } | |
4013 | } | |
1da177e4 | 4014 | out_unlock: |
5a16f3d3 RR |
4015 | free_cpumask_var(new_mask); |
4016 | out_free_cpus_allowed: | |
4017 | free_cpumask_var(cpus_allowed); | |
4018 | out_put_task: | |
1da177e4 | 4019 | put_task_struct(p); |
1da177e4 LT |
4020 | return retval; |
4021 | } | |
4022 | ||
4023 | static int get_user_cpu_mask(unsigned long __user *user_mask_ptr, unsigned len, | |
96f874e2 | 4024 | struct cpumask *new_mask) |
1da177e4 | 4025 | { |
96f874e2 RR |
4026 | if (len < cpumask_size()) |
4027 | cpumask_clear(new_mask); | |
4028 | else if (len > cpumask_size()) | |
4029 | len = cpumask_size(); | |
4030 | ||
1da177e4 LT |
4031 | return copy_from_user(new_mask, user_mask_ptr, len) ? -EFAULT : 0; |
4032 | } | |
4033 | ||
4034 | /** | |
4035 | * sys_sched_setaffinity - set the cpu affinity of a process | |
4036 | * @pid: pid of the process | |
4037 | * @len: length in bytes of the bitmask pointed to by user_mask_ptr | |
4038 | * @user_mask_ptr: user-space pointer to the new cpu mask | |
e69f6186 YB |
4039 | * |
4040 | * Return: 0 on success. An error code otherwise. | |
1da177e4 | 4041 | */ |
5add95d4 HC |
4042 | SYSCALL_DEFINE3(sched_setaffinity, pid_t, pid, unsigned int, len, |
4043 | unsigned long __user *, user_mask_ptr) | |
1da177e4 | 4044 | { |
5a16f3d3 | 4045 | cpumask_var_t new_mask; |
1da177e4 LT |
4046 | int retval; |
4047 | ||
5a16f3d3 RR |
4048 | if (!alloc_cpumask_var(&new_mask, GFP_KERNEL)) |
4049 | return -ENOMEM; | |
1da177e4 | 4050 | |
5a16f3d3 RR |
4051 | retval = get_user_cpu_mask(user_mask_ptr, len, new_mask); |
4052 | if (retval == 0) | |
4053 | retval = sched_setaffinity(pid, new_mask); | |
4054 | free_cpumask_var(new_mask); | |
4055 | return retval; | |
1da177e4 LT |
4056 | } |
4057 | ||
96f874e2 | 4058 | long sched_getaffinity(pid_t pid, struct cpumask *mask) |
1da177e4 | 4059 | { |
36c8b586 | 4060 | struct task_struct *p; |
31605683 | 4061 | unsigned long flags; |
1da177e4 | 4062 | int retval; |
1da177e4 | 4063 | |
23f5d142 | 4064 | rcu_read_lock(); |
1da177e4 LT |
4065 | |
4066 | retval = -ESRCH; | |
4067 | p = find_process_by_pid(pid); | |
4068 | if (!p) | |
4069 | goto out_unlock; | |
4070 | ||
e7834f8f DQ |
4071 | retval = security_task_getscheduler(p); |
4072 | if (retval) | |
4073 | goto out_unlock; | |
4074 | ||
013fdb80 | 4075 | raw_spin_lock_irqsave(&p->pi_lock, flags); |
6acce3ef | 4076 | cpumask_and(mask, &p->cpus_allowed, cpu_active_mask); |
013fdb80 | 4077 | raw_spin_unlock_irqrestore(&p->pi_lock, flags); |
1da177e4 LT |
4078 | |
4079 | out_unlock: | |
23f5d142 | 4080 | rcu_read_unlock(); |
1da177e4 | 4081 | |
9531b62f | 4082 | return retval; |
1da177e4 LT |
4083 | } |
4084 | ||
4085 | /** | |
4086 | * sys_sched_getaffinity - get the cpu affinity of a process | |
4087 | * @pid: pid of the process | |
4088 | * @len: length in bytes of the bitmask pointed to by user_mask_ptr | |
4089 | * @user_mask_ptr: user-space pointer to hold the current cpu mask | |
e69f6186 YB |
4090 | * |
4091 | * Return: 0 on success. An error code otherwise. | |
1da177e4 | 4092 | */ |
5add95d4 HC |
4093 | SYSCALL_DEFINE3(sched_getaffinity, pid_t, pid, unsigned int, len, |
4094 | unsigned long __user *, user_mask_ptr) | |
1da177e4 LT |
4095 | { |
4096 | int ret; | |
f17c8607 | 4097 | cpumask_var_t mask; |
1da177e4 | 4098 | |
84fba5ec | 4099 | if ((len * BITS_PER_BYTE) < nr_cpu_ids) |
cd3d8031 KM |
4100 | return -EINVAL; |
4101 | if (len & (sizeof(unsigned long)-1)) | |
1da177e4 LT |
4102 | return -EINVAL; |
4103 | ||
f17c8607 RR |
4104 | if (!alloc_cpumask_var(&mask, GFP_KERNEL)) |
4105 | return -ENOMEM; | |
1da177e4 | 4106 | |
f17c8607 RR |
4107 | ret = sched_getaffinity(pid, mask); |
4108 | if (ret == 0) { | |
8bc037fb | 4109 | size_t retlen = min_t(size_t, len, cpumask_size()); |
cd3d8031 KM |
4110 | |
4111 | if (copy_to_user(user_mask_ptr, mask, retlen)) | |
f17c8607 RR |
4112 | ret = -EFAULT; |
4113 | else | |
cd3d8031 | 4114 | ret = retlen; |
f17c8607 RR |
4115 | } |
4116 | free_cpumask_var(mask); | |
1da177e4 | 4117 | |
f17c8607 | 4118 | return ret; |
1da177e4 LT |
4119 | } |
4120 | ||
4121 | /** | |
4122 | * sys_sched_yield - yield the current processor to other threads. | |
4123 | * | |
dd41f596 IM |
4124 | * This function yields the current CPU to other tasks. If there are no |
4125 | * other threads running on this CPU then this function will return. | |
e69f6186 YB |
4126 | * |
4127 | * Return: 0. | |
1da177e4 | 4128 | */ |
5add95d4 | 4129 | SYSCALL_DEFINE0(sched_yield) |
1da177e4 | 4130 | { |
70b97a7f | 4131 | struct rq *rq = this_rq_lock(); |
1da177e4 | 4132 | |
2d72376b | 4133 | schedstat_inc(rq, yld_count); |
4530d7ab | 4134 | current->sched_class->yield_task(rq); |
1da177e4 LT |
4135 | |
4136 | /* | |
4137 | * Since we are going to call schedule() anyway, there's | |
4138 | * no need to preempt or enable interrupts: | |
4139 | */ | |
4140 | __release(rq->lock); | |
8a25d5de | 4141 | spin_release(&rq->lock.dep_map, 1, _THIS_IP_); |
9828ea9d | 4142 | do_raw_spin_unlock(&rq->lock); |
ba74c144 | 4143 | sched_preempt_enable_no_resched(); |
1da177e4 LT |
4144 | |
4145 | schedule(); | |
4146 | ||
4147 | return 0; | |
4148 | } | |
4149 | ||
e7b38404 | 4150 | static void __cond_resched(void) |
1da177e4 | 4151 | { |
bdb43806 | 4152 | __preempt_count_add(PREEMPT_ACTIVE); |
c259e01a | 4153 | __schedule(); |
bdb43806 | 4154 | __preempt_count_sub(PREEMPT_ACTIVE); |
1da177e4 LT |
4155 | } |
4156 | ||
02b67cc3 | 4157 | int __sched _cond_resched(void) |
1da177e4 | 4158 | { |
ac1bea85 | 4159 | rcu_cond_resched(); |
d86ee480 | 4160 | if (should_resched()) { |
1da177e4 LT |
4161 | __cond_resched(); |
4162 | return 1; | |
4163 | } | |
4164 | return 0; | |
4165 | } | |
02b67cc3 | 4166 | EXPORT_SYMBOL(_cond_resched); |
1da177e4 LT |
4167 | |
4168 | /* | |
613afbf8 | 4169 | * __cond_resched_lock() - if a reschedule is pending, drop the given lock, |
1da177e4 LT |
4170 | * call schedule, and on return reacquire the lock. |
4171 | * | |
41a2d6cf | 4172 | * This works OK both with and without CONFIG_PREEMPT. We do strange low-level |
1da177e4 LT |
4173 | * operations here to prevent schedule() from being called twice (once via |
4174 | * spin_unlock(), once by hand). | |
4175 | */ | |
613afbf8 | 4176 | int __cond_resched_lock(spinlock_t *lock) |
1da177e4 | 4177 | { |
ac1bea85 | 4178 | bool need_rcu_resched = rcu_should_resched(); |
d86ee480 | 4179 | int resched = should_resched(); |
6df3cecb JK |
4180 | int ret = 0; |
4181 | ||
f607c668 PZ |
4182 | lockdep_assert_held(lock); |
4183 | ||
ac1bea85 | 4184 | if (spin_needbreak(lock) || resched || need_rcu_resched) { |
1da177e4 | 4185 | spin_unlock(lock); |
d86ee480 | 4186 | if (resched) |
95c354fe | 4187 | __cond_resched(); |
ac1bea85 PM |
4188 | else if (unlikely(need_rcu_resched)) |
4189 | rcu_resched(); | |
95c354fe NP |
4190 | else |
4191 | cpu_relax(); | |
6df3cecb | 4192 | ret = 1; |
1da177e4 | 4193 | spin_lock(lock); |
1da177e4 | 4194 | } |
6df3cecb | 4195 | return ret; |
1da177e4 | 4196 | } |
613afbf8 | 4197 | EXPORT_SYMBOL(__cond_resched_lock); |
1da177e4 | 4198 | |
613afbf8 | 4199 | int __sched __cond_resched_softirq(void) |
1da177e4 LT |
4200 | { |
4201 | BUG_ON(!in_softirq()); | |
4202 | ||
ac1bea85 | 4203 | rcu_cond_resched(); /* BH disabled OK, just recording QSes. */ |
d86ee480 | 4204 | if (should_resched()) { |
98d82567 | 4205 | local_bh_enable(); |
1da177e4 LT |
4206 | __cond_resched(); |
4207 | local_bh_disable(); | |
4208 | return 1; | |
4209 | } | |
4210 | return 0; | |
4211 | } | |
613afbf8 | 4212 | EXPORT_SYMBOL(__cond_resched_softirq); |
1da177e4 | 4213 | |
1da177e4 LT |
4214 | /** |
4215 | * yield - yield the current processor to other threads. | |
4216 | * | |
8e3fabfd PZ |
4217 | * Do not ever use this function, there's a 99% chance you're doing it wrong. |
4218 | * | |
4219 | * The scheduler is at all times free to pick the calling task as the most | |
4220 | * eligible task to run, if removing the yield() call from your code breaks | |
4221 | * it, its already broken. | |
4222 | * | |
4223 | * Typical broken usage is: | |
4224 | * | |
4225 | * while (!event) | |
4226 | * yield(); | |
4227 | * | |
4228 | * where one assumes that yield() will let 'the other' process run that will | |
4229 | * make event true. If the current task is a SCHED_FIFO task that will never | |
4230 | * happen. Never use yield() as a progress guarantee!! | |
4231 | * | |
4232 | * If you want to use yield() to wait for something, use wait_event(). | |
4233 | * If you want to use yield() to be 'nice' for others, use cond_resched(). | |
4234 | * If you still want to use yield(), do not! | |
1da177e4 LT |
4235 | */ |
4236 | void __sched yield(void) | |
4237 | { | |
4238 | set_current_state(TASK_RUNNING); | |
4239 | sys_sched_yield(); | |
4240 | } | |
1da177e4 LT |
4241 | EXPORT_SYMBOL(yield); |
4242 | ||
d95f4122 MG |
4243 | /** |
4244 | * yield_to - yield the current processor to another thread in | |
4245 | * your thread group, or accelerate that thread toward the | |
4246 | * processor it's on. | |
16addf95 RD |
4247 | * @p: target task |
4248 | * @preempt: whether task preemption is allowed or not | |
d95f4122 MG |
4249 | * |
4250 | * It's the caller's job to ensure that the target task struct | |
4251 | * can't go away on us before we can do any checks. | |
4252 | * | |
e69f6186 | 4253 | * Return: |
7b270f60 PZ |
4254 | * true (>0) if we indeed boosted the target task. |
4255 | * false (0) if we failed to boost the target. | |
4256 | * -ESRCH if there's no task to yield to. | |
d95f4122 | 4257 | */ |
fa93384f | 4258 | int __sched yield_to(struct task_struct *p, bool preempt) |
d95f4122 MG |
4259 | { |
4260 | struct task_struct *curr = current; | |
4261 | struct rq *rq, *p_rq; | |
4262 | unsigned long flags; | |
c3c18640 | 4263 | int yielded = 0; |
d95f4122 MG |
4264 | |
4265 | local_irq_save(flags); | |
4266 | rq = this_rq(); | |
4267 | ||
4268 | again: | |
4269 | p_rq = task_rq(p); | |
7b270f60 PZ |
4270 | /* |
4271 | * If we're the only runnable task on the rq and target rq also | |
4272 | * has only one task, there's absolutely no point in yielding. | |
4273 | */ | |
4274 | if (rq->nr_running == 1 && p_rq->nr_running == 1) { | |
4275 | yielded = -ESRCH; | |
4276 | goto out_irq; | |
4277 | } | |
4278 | ||
d95f4122 | 4279 | double_rq_lock(rq, p_rq); |
39e24d8f | 4280 | if (task_rq(p) != p_rq) { |
d95f4122 MG |
4281 | double_rq_unlock(rq, p_rq); |
4282 | goto again; | |
4283 | } | |
4284 | ||
4285 | if (!curr->sched_class->yield_to_task) | |
7b270f60 | 4286 | goto out_unlock; |
d95f4122 MG |
4287 | |
4288 | if (curr->sched_class != p->sched_class) | |
7b270f60 | 4289 | goto out_unlock; |
d95f4122 MG |
4290 | |
4291 | if (task_running(p_rq, p) || p->state) | |
7b270f60 | 4292 | goto out_unlock; |
d95f4122 MG |
4293 | |
4294 | yielded = curr->sched_class->yield_to_task(rq, p, preempt); | |
6d1cafd8 | 4295 | if (yielded) { |
d95f4122 | 4296 | schedstat_inc(rq, yld_count); |
6d1cafd8 VP |
4297 | /* |
4298 | * Make p's CPU reschedule; pick_next_entity takes care of | |
4299 | * fairness. | |
4300 | */ | |
4301 | if (preempt && rq != p_rq) | |
4302 | resched_task(p_rq->curr); | |
4303 | } | |
d95f4122 | 4304 | |
7b270f60 | 4305 | out_unlock: |
d95f4122 | 4306 | double_rq_unlock(rq, p_rq); |
7b270f60 | 4307 | out_irq: |
d95f4122 MG |
4308 | local_irq_restore(flags); |
4309 | ||
7b270f60 | 4310 | if (yielded > 0) |
d95f4122 MG |
4311 | schedule(); |
4312 | ||
4313 | return yielded; | |
4314 | } | |
4315 | EXPORT_SYMBOL_GPL(yield_to); | |
4316 | ||
1da177e4 | 4317 | /* |
41a2d6cf | 4318 | * This task is about to go to sleep on IO. Increment rq->nr_iowait so |
1da177e4 | 4319 | * that process accounting knows that this is a task in IO wait state. |
1da177e4 LT |
4320 | */ |
4321 | void __sched io_schedule(void) | |
4322 | { | |
54d35f29 | 4323 | struct rq *rq = raw_rq(); |
1da177e4 | 4324 | |
0ff92245 | 4325 | delayacct_blkio_start(); |
1da177e4 | 4326 | atomic_inc(&rq->nr_iowait); |
73c10101 | 4327 | blk_flush_plug(current); |
8f0dfc34 | 4328 | current->in_iowait = 1; |
1da177e4 | 4329 | schedule(); |
8f0dfc34 | 4330 | current->in_iowait = 0; |
1da177e4 | 4331 | atomic_dec(&rq->nr_iowait); |
0ff92245 | 4332 | delayacct_blkio_end(); |
1da177e4 | 4333 | } |
1da177e4 LT |
4334 | EXPORT_SYMBOL(io_schedule); |
4335 | ||
4336 | long __sched io_schedule_timeout(long timeout) | |
4337 | { | |
54d35f29 | 4338 | struct rq *rq = raw_rq(); |
1da177e4 LT |
4339 | long ret; |
4340 | ||
0ff92245 | 4341 | delayacct_blkio_start(); |
1da177e4 | 4342 | atomic_inc(&rq->nr_iowait); |
73c10101 | 4343 | blk_flush_plug(current); |
8f0dfc34 | 4344 | current->in_iowait = 1; |
1da177e4 | 4345 | ret = schedule_timeout(timeout); |
8f0dfc34 | 4346 | current->in_iowait = 0; |
1da177e4 | 4347 | atomic_dec(&rq->nr_iowait); |
0ff92245 | 4348 | delayacct_blkio_end(); |
1da177e4 LT |
4349 | return ret; |
4350 | } | |
4351 | ||
4352 | /** | |
4353 | * sys_sched_get_priority_max - return maximum RT priority. | |
4354 | * @policy: scheduling class. | |
4355 | * | |
e69f6186 YB |
4356 | * Return: On success, this syscall returns the maximum |
4357 | * rt_priority that can be used by a given scheduling class. | |
4358 | * On failure, a negative error code is returned. | |
1da177e4 | 4359 | */ |
5add95d4 | 4360 | SYSCALL_DEFINE1(sched_get_priority_max, int, policy) |
1da177e4 LT |
4361 | { |
4362 | int ret = -EINVAL; | |
4363 | ||
4364 | switch (policy) { | |
4365 | case SCHED_FIFO: | |
4366 | case SCHED_RR: | |
4367 | ret = MAX_USER_RT_PRIO-1; | |
4368 | break; | |
aab03e05 | 4369 | case SCHED_DEADLINE: |
1da177e4 | 4370 | case SCHED_NORMAL: |
b0a9499c | 4371 | case SCHED_BATCH: |
dd41f596 | 4372 | case SCHED_IDLE: |
1da177e4 LT |
4373 | ret = 0; |
4374 | break; | |
4375 | } | |
4376 | return ret; | |
4377 | } | |
4378 | ||
4379 | /** | |
4380 | * sys_sched_get_priority_min - return minimum RT priority. | |
4381 | * @policy: scheduling class. | |
4382 | * | |
e69f6186 YB |
4383 | * Return: On success, this syscall returns the minimum |
4384 | * rt_priority that can be used by a given scheduling class. | |
4385 | * On failure, a negative error code is returned. | |
1da177e4 | 4386 | */ |
5add95d4 | 4387 | SYSCALL_DEFINE1(sched_get_priority_min, int, policy) |
1da177e4 LT |
4388 | { |
4389 | int ret = -EINVAL; | |
4390 | ||
4391 | switch (policy) { | |
4392 | case SCHED_FIFO: | |
4393 | case SCHED_RR: | |
4394 | ret = 1; | |
4395 | break; | |
aab03e05 | 4396 | case SCHED_DEADLINE: |
1da177e4 | 4397 | case SCHED_NORMAL: |
b0a9499c | 4398 | case SCHED_BATCH: |
dd41f596 | 4399 | case SCHED_IDLE: |
1da177e4 LT |
4400 | ret = 0; |
4401 | } | |
4402 | return ret; | |
4403 | } | |
4404 | ||
4405 | /** | |
4406 | * sys_sched_rr_get_interval - return the default timeslice of a process. | |
4407 | * @pid: pid of the process. | |
4408 | * @interval: userspace pointer to the timeslice value. | |
4409 | * | |
4410 | * this syscall writes the default timeslice value of a given process | |
4411 | * into the user-space timespec buffer. A value of '0' means infinity. | |
e69f6186 YB |
4412 | * |
4413 | * Return: On success, 0 and the timeslice is in @interval. Otherwise, | |
4414 | * an error code. | |
1da177e4 | 4415 | */ |
17da2bd9 | 4416 | SYSCALL_DEFINE2(sched_rr_get_interval, pid_t, pid, |
754fe8d2 | 4417 | struct timespec __user *, interval) |
1da177e4 | 4418 | { |
36c8b586 | 4419 | struct task_struct *p; |
a4ec24b4 | 4420 | unsigned int time_slice; |
dba091b9 TG |
4421 | unsigned long flags; |
4422 | struct rq *rq; | |
3a5c359a | 4423 | int retval; |
1da177e4 | 4424 | struct timespec t; |
1da177e4 LT |
4425 | |
4426 | if (pid < 0) | |
3a5c359a | 4427 | return -EINVAL; |
1da177e4 LT |
4428 | |
4429 | retval = -ESRCH; | |
1a551ae7 | 4430 | rcu_read_lock(); |
1da177e4 LT |
4431 | p = find_process_by_pid(pid); |
4432 | if (!p) | |
4433 | goto out_unlock; | |
4434 | ||
4435 | retval = security_task_getscheduler(p); | |
4436 | if (retval) | |
4437 | goto out_unlock; | |
4438 | ||
dba091b9 | 4439 | rq = task_rq_lock(p, &flags); |
a57beec5 PZ |
4440 | time_slice = 0; |
4441 | if (p->sched_class->get_rr_interval) | |
4442 | time_slice = p->sched_class->get_rr_interval(rq, p); | |
0122ec5b | 4443 | task_rq_unlock(rq, p, &flags); |
a4ec24b4 | 4444 | |
1a551ae7 | 4445 | rcu_read_unlock(); |
a4ec24b4 | 4446 | jiffies_to_timespec(time_slice, &t); |
1da177e4 | 4447 | retval = copy_to_user(interval, &t, sizeof(t)) ? -EFAULT : 0; |
1da177e4 | 4448 | return retval; |
3a5c359a | 4449 | |
1da177e4 | 4450 | out_unlock: |
1a551ae7 | 4451 | rcu_read_unlock(); |
1da177e4 LT |
4452 | return retval; |
4453 | } | |
4454 | ||
7c731e0a | 4455 | static const char stat_nam[] = TASK_STATE_TO_CHAR_STR; |
36c8b586 | 4456 | |
82a1fcb9 | 4457 | void sched_show_task(struct task_struct *p) |
1da177e4 | 4458 | { |
1da177e4 | 4459 | unsigned long free = 0; |
4e79752c | 4460 | int ppid; |
36c8b586 | 4461 | unsigned state; |
1da177e4 | 4462 | |
1da177e4 | 4463 | state = p->state ? __ffs(p->state) + 1 : 0; |
28d0686c | 4464 | printk(KERN_INFO "%-15.15s %c", p->comm, |
2ed6e34f | 4465 | state < sizeof(stat_nam) - 1 ? stat_nam[state] : '?'); |
4bd77321 | 4466 | #if BITS_PER_LONG == 32 |
1da177e4 | 4467 | if (state == TASK_RUNNING) |
3df0fc5b | 4468 | printk(KERN_CONT " running "); |
1da177e4 | 4469 | else |
3df0fc5b | 4470 | printk(KERN_CONT " %08lx ", thread_saved_pc(p)); |
1da177e4 LT |
4471 | #else |
4472 | if (state == TASK_RUNNING) | |
3df0fc5b | 4473 | printk(KERN_CONT " running task "); |
1da177e4 | 4474 | else |
3df0fc5b | 4475 | printk(KERN_CONT " %016lx ", thread_saved_pc(p)); |
1da177e4 LT |
4476 | #endif |
4477 | #ifdef CONFIG_DEBUG_STACK_USAGE | |
7c9f8861 | 4478 | free = stack_not_used(p); |
1da177e4 | 4479 | #endif |
4e79752c PM |
4480 | rcu_read_lock(); |
4481 | ppid = task_pid_nr(rcu_dereference(p->real_parent)); | |
4482 | rcu_read_unlock(); | |
3df0fc5b | 4483 | printk(KERN_CONT "%5lu %5d %6d 0x%08lx\n", free, |
4e79752c | 4484 | task_pid_nr(p), ppid, |
aa47b7e0 | 4485 | (unsigned long)task_thread_info(p)->flags); |
1da177e4 | 4486 | |
3d1cb205 | 4487 | print_worker_info(KERN_INFO, p); |
5fb5e6de | 4488 | show_stack(p, NULL); |
1da177e4 LT |
4489 | } |
4490 | ||
e59e2ae2 | 4491 | void show_state_filter(unsigned long state_filter) |
1da177e4 | 4492 | { |
36c8b586 | 4493 | struct task_struct *g, *p; |
1da177e4 | 4494 | |
4bd77321 | 4495 | #if BITS_PER_LONG == 32 |
3df0fc5b PZ |
4496 | printk(KERN_INFO |
4497 | " task PC stack pid father\n"); | |
1da177e4 | 4498 | #else |
3df0fc5b PZ |
4499 | printk(KERN_INFO |
4500 | " task PC stack pid father\n"); | |
1da177e4 | 4501 | #endif |
510f5acc | 4502 | rcu_read_lock(); |
1da177e4 LT |
4503 | do_each_thread(g, p) { |
4504 | /* | |
4505 | * reset the NMI-timeout, listing all files on a slow | |
25985edc | 4506 | * console might take a lot of time: |
1da177e4 LT |
4507 | */ |
4508 | touch_nmi_watchdog(); | |
39bc89fd | 4509 | if (!state_filter || (p->state & state_filter)) |
82a1fcb9 | 4510 | sched_show_task(p); |
1da177e4 LT |
4511 | } while_each_thread(g, p); |
4512 | ||
04c9167f JF |
4513 | touch_all_softlockup_watchdogs(); |
4514 | ||
dd41f596 IM |
4515 | #ifdef CONFIG_SCHED_DEBUG |
4516 | sysrq_sched_debug_show(); | |
4517 | #endif | |
510f5acc | 4518 | rcu_read_unlock(); |
e59e2ae2 IM |
4519 | /* |
4520 | * Only show locks if all tasks are dumped: | |
4521 | */ | |
93335a21 | 4522 | if (!state_filter) |
e59e2ae2 | 4523 | debug_show_all_locks(); |
1da177e4 LT |
4524 | } |
4525 | ||
0db0628d | 4526 | void init_idle_bootup_task(struct task_struct *idle) |
1df21055 | 4527 | { |
dd41f596 | 4528 | idle->sched_class = &idle_sched_class; |
1df21055 IM |
4529 | } |
4530 | ||
f340c0d1 IM |
4531 | /** |
4532 | * init_idle - set up an idle thread for a given CPU | |
4533 | * @idle: task in question | |
4534 | * @cpu: cpu the idle task belongs to | |
4535 | * | |
4536 | * NOTE: this function does not set the idle thread's NEED_RESCHED | |
4537 | * flag, to make booting more robust. | |
4538 | */ | |
0db0628d | 4539 | void init_idle(struct task_struct *idle, int cpu) |
1da177e4 | 4540 | { |
70b97a7f | 4541 | struct rq *rq = cpu_rq(cpu); |
1da177e4 LT |
4542 | unsigned long flags; |
4543 | ||
05fa785c | 4544 | raw_spin_lock_irqsave(&rq->lock, flags); |
5cbd54ef | 4545 | |
5e1576ed | 4546 | __sched_fork(0, idle); |
06b83b5f | 4547 | idle->state = TASK_RUNNING; |
dd41f596 IM |
4548 | idle->se.exec_start = sched_clock(); |
4549 | ||
1e1b6c51 | 4550 | do_set_cpus_allowed(idle, cpumask_of(cpu)); |
6506cf6c PZ |
4551 | /* |
4552 | * We're having a chicken and egg problem, even though we are | |
4553 | * holding rq->lock, the cpu isn't yet set to this cpu so the | |
4554 | * lockdep check in task_group() will fail. | |
4555 | * | |
4556 | * Similar case to sched_fork(). / Alternatively we could | |
4557 | * use task_rq_lock() here and obtain the other rq->lock. | |
4558 | * | |
4559 | * Silence PROVE_RCU | |
4560 | */ | |
4561 | rcu_read_lock(); | |
dd41f596 | 4562 | __set_task_cpu(idle, cpu); |
6506cf6c | 4563 | rcu_read_unlock(); |
1da177e4 | 4564 | |
1da177e4 | 4565 | rq->curr = rq->idle = idle; |
77177856 | 4566 | idle->on_rq = 1; |
3ca7a440 PZ |
4567 | #if defined(CONFIG_SMP) |
4568 | idle->on_cpu = 1; | |
4866cde0 | 4569 | #endif |
05fa785c | 4570 | raw_spin_unlock_irqrestore(&rq->lock, flags); |
1da177e4 LT |
4571 | |
4572 | /* Set the preempt count _outside_ the spinlocks! */ | |
01028747 | 4573 | init_idle_preempt_count(idle, cpu); |
55cd5340 | 4574 | |
dd41f596 IM |
4575 | /* |
4576 | * The idle tasks have their own, simple scheduling class: | |
4577 | */ | |
4578 | idle->sched_class = &idle_sched_class; | |
868baf07 | 4579 | ftrace_graph_init_idle_task(idle, cpu); |
45eacc69 | 4580 | vtime_init_idle(idle, cpu); |
f1c6f1a7 CE |
4581 | #if defined(CONFIG_SMP) |
4582 | sprintf(idle->comm, "%s/%d", INIT_TASK_COMM, cpu); | |
4583 | #endif | |
19978ca6 IM |
4584 | } |
4585 | ||
1da177e4 | 4586 | #ifdef CONFIG_SMP |
1e1b6c51 KM |
4587 | void do_set_cpus_allowed(struct task_struct *p, const struct cpumask *new_mask) |
4588 | { | |
4589 | if (p->sched_class && p->sched_class->set_cpus_allowed) | |
4590 | p->sched_class->set_cpus_allowed(p, new_mask); | |
4939602a PZ |
4591 | |
4592 | cpumask_copy(&p->cpus_allowed, new_mask); | |
29baa747 | 4593 | p->nr_cpus_allowed = cpumask_weight(new_mask); |
1e1b6c51 KM |
4594 | } |
4595 | ||
1da177e4 LT |
4596 | /* |
4597 | * This is how migration works: | |
4598 | * | |
969c7921 TH |
4599 | * 1) we invoke migration_cpu_stop() on the target CPU using |
4600 | * stop_one_cpu(). | |
4601 | * 2) stopper starts to run (implicitly forcing the migrated thread | |
4602 | * off the CPU) | |
4603 | * 3) it checks whether the migrated task is still in the wrong runqueue. | |
4604 | * 4) if it's in the wrong runqueue then the migration thread removes | |
1da177e4 | 4605 | * it and puts it into the right queue. |
969c7921 TH |
4606 | * 5) stopper completes and stop_one_cpu() returns and the migration |
4607 | * is done. | |
1da177e4 LT |
4608 | */ |
4609 | ||
4610 | /* | |
4611 | * Change a given task's CPU affinity. Migrate the thread to a | |
4612 | * proper CPU and schedule it away if the CPU it's executing on | |
4613 | * is removed from the allowed bitmask. | |
4614 | * | |
4615 | * NOTE: the caller must have a valid reference to the task, the | |
41a2d6cf | 4616 | * task must not exit() & deallocate itself prematurely. The |
1da177e4 LT |
4617 | * call is not atomic; no spinlocks may be held. |
4618 | */ | |
96f874e2 | 4619 | int set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask) |
1da177e4 LT |
4620 | { |
4621 | unsigned long flags; | |
70b97a7f | 4622 | struct rq *rq; |
969c7921 | 4623 | unsigned int dest_cpu; |
48f24c4d | 4624 | int ret = 0; |
1da177e4 LT |
4625 | |
4626 | rq = task_rq_lock(p, &flags); | |
e2912009 | 4627 | |
db44fc01 YZ |
4628 | if (cpumask_equal(&p->cpus_allowed, new_mask)) |
4629 | goto out; | |
4630 | ||
6ad4c188 | 4631 | if (!cpumask_intersects(new_mask, cpu_active_mask)) { |
1da177e4 LT |
4632 | ret = -EINVAL; |
4633 | goto out; | |
4634 | } | |
4635 | ||
1e1b6c51 | 4636 | do_set_cpus_allowed(p, new_mask); |
73fe6aae | 4637 | |
1da177e4 | 4638 | /* Can the task run on the task's current CPU? If so, we're done */ |
96f874e2 | 4639 | if (cpumask_test_cpu(task_cpu(p), new_mask)) |
1da177e4 LT |
4640 | goto out; |
4641 | ||
969c7921 | 4642 | dest_cpu = cpumask_any_and(cpu_active_mask, new_mask); |
bd8e7dde | 4643 | if (p->on_rq) { |
969c7921 | 4644 | struct migration_arg arg = { p, dest_cpu }; |
1da177e4 | 4645 | /* Need help from migration thread: drop lock and wait. */ |
0122ec5b | 4646 | task_rq_unlock(rq, p, &flags); |
969c7921 | 4647 | stop_one_cpu(cpu_of(rq), migration_cpu_stop, &arg); |
1da177e4 LT |
4648 | tlb_migrate_finish(p->mm); |
4649 | return 0; | |
4650 | } | |
4651 | out: | |
0122ec5b | 4652 | task_rq_unlock(rq, p, &flags); |
48f24c4d | 4653 | |
1da177e4 LT |
4654 | return ret; |
4655 | } | |
cd8ba7cd | 4656 | EXPORT_SYMBOL_GPL(set_cpus_allowed_ptr); |
1da177e4 LT |
4657 | |
4658 | /* | |
41a2d6cf | 4659 | * Move (not current) task off this cpu, onto dest cpu. We're doing |
1da177e4 LT |
4660 | * this because either it can't run here any more (set_cpus_allowed() |
4661 | * away from this CPU, or CPU going down), or because we're | |
4662 | * attempting to rebalance this task on exec (sched_exec). | |
4663 | * | |
4664 | * So we race with normal scheduler movements, but that's OK, as long | |
4665 | * as the task is no longer on this CPU. | |
efc30814 KK |
4666 | * |
4667 | * Returns non-zero if task was successfully migrated. | |
1da177e4 | 4668 | */ |
efc30814 | 4669 | static int __migrate_task(struct task_struct *p, int src_cpu, int dest_cpu) |
1da177e4 | 4670 | { |
70b97a7f | 4671 | struct rq *rq_dest, *rq_src; |
e2912009 | 4672 | int ret = 0; |
1da177e4 | 4673 | |
e761b772 | 4674 | if (unlikely(!cpu_active(dest_cpu))) |
efc30814 | 4675 | return ret; |
1da177e4 LT |
4676 | |
4677 | rq_src = cpu_rq(src_cpu); | |
4678 | rq_dest = cpu_rq(dest_cpu); | |
4679 | ||
0122ec5b | 4680 | raw_spin_lock(&p->pi_lock); |
1da177e4 LT |
4681 | double_rq_lock(rq_src, rq_dest); |
4682 | /* Already moved. */ | |
4683 | if (task_cpu(p) != src_cpu) | |
b1e38734 | 4684 | goto done; |
1da177e4 | 4685 | /* Affinity changed (again). */ |
fa17b507 | 4686 | if (!cpumask_test_cpu(dest_cpu, tsk_cpus_allowed(p))) |
b1e38734 | 4687 | goto fail; |
1da177e4 | 4688 | |
e2912009 PZ |
4689 | /* |
4690 | * If we're not on a rq, the next wake-up will ensure we're | |
4691 | * placed properly. | |
4692 | */ | |
fd2f4419 | 4693 | if (p->on_rq) { |
4ca9b72b | 4694 | dequeue_task(rq_src, p, 0); |
e2912009 | 4695 | set_task_cpu(p, dest_cpu); |
4ca9b72b | 4696 | enqueue_task(rq_dest, p, 0); |
15afe09b | 4697 | check_preempt_curr(rq_dest, p, 0); |
1da177e4 | 4698 | } |
b1e38734 | 4699 | done: |
efc30814 | 4700 | ret = 1; |
b1e38734 | 4701 | fail: |
1da177e4 | 4702 | double_rq_unlock(rq_src, rq_dest); |
0122ec5b | 4703 | raw_spin_unlock(&p->pi_lock); |
efc30814 | 4704 | return ret; |
1da177e4 LT |
4705 | } |
4706 | ||
e6628d5b MG |
4707 | #ifdef CONFIG_NUMA_BALANCING |
4708 | /* Migrate current task p to target_cpu */ | |
4709 | int migrate_task_to(struct task_struct *p, int target_cpu) | |
4710 | { | |
4711 | struct migration_arg arg = { p, target_cpu }; | |
4712 | int curr_cpu = task_cpu(p); | |
4713 | ||
4714 | if (curr_cpu == target_cpu) | |
4715 | return 0; | |
4716 | ||
4717 | if (!cpumask_test_cpu(target_cpu, tsk_cpus_allowed(p))) | |
4718 | return -EINVAL; | |
4719 | ||
4720 | /* TODO: This is not properly updating schedstats */ | |
4721 | ||
286549dc | 4722 | trace_sched_move_numa(p, curr_cpu, target_cpu); |
e6628d5b MG |
4723 | return stop_one_cpu(curr_cpu, migration_cpu_stop, &arg); |
4724 | } | |
0ec8aa00 PZ |
4725 | |
4726 | /* | |
4727 | * Requeue a task on a given node and accurately track the number of NUMA | |
4728 | * tasks on the runqueues | |
4729 | */ | |
4730 | void sched_setnuma(struct task_struct *p, int nid) | |
4731 | { | |
4732 | struct rq *rq; | |
4733 | unsigned long flags; | |
4734 | bool on_rq, running; | |
4735 | ||
4736 | rq = task_rq_lock(p, &flags); | |
4737 | on_rq = p->on_rq; | |
4738 | running = task_current(rq, p); | |
4739 | ||
4740 | if (on_rq) | |
4741 | dequeue_task(rq, p, 0); | |
4742 | if (running) | |
4743 | p->sched_class->put_prev_task(rq, p); | |
4744 | ||
4745 | p->numa_preferred_nid = nid; | |
0ec8aa00 PZ |
4746 | |
4747 | if (running) | |
4748 | p->sched_class->set_curr_task(rq); | |
4749 | if (on_rq) | |
4750 | enqueue_task(rq, p, 0); | |
4751 | task_rq_unlock(rq, p, &flags); | |
4752 | } | |
e6628d5b MG |
4753 | #endif |
4754 | ||
1da177e4 | 4755 | /* |
969c7921 TH |
4756 | * migration_cpu_stop - this will be executed by a highprio stopper thread |
4757 | * and performs thread migration by bumping thread off CPU then | |
4758 | * 'pushing' onto another runqueue. | |
1da177e4 | 4759 | */ |
969c7921 | 4760 | static int migration_cpu_stop(void *data) |
1da177e4 | 4761 | { |
969c7921 | 4762 | struct migration_arg *arg = data; |
f7b4cddc | 4763 | |
969c7921 TH |
4764 | /* |
4765 | * The original target cpu might have gone down and we might | |
4766 | * be on another cpu but it doesn't matter. | |
4767 | */ | |
f7b4cddc | 4768 | local_irq_disable(); |
969c7921 | 4769 | __migrate_task(arg->task, raw_smp_processor_id(), arg->dest_cpu); |
f7b4cddc | 4770 | local_irq_enable(); |
1da177e4 | 4771 | return 0; |
f7b4cddc ON |
4772 | } |
4773 | ||
1da177e4 | 4774 | #ifdef CONFIG_HOTPLUG_CPU |
48c5ccae | 4775 | |
054b9108 | 4776 | /* |
48c5ccae PZ |
4777 | * Ensures that the idle task is using init_mm right before its cpu goes |
4778 | * offline. | |
054b9108 | 4779 | */ |
48c5ccae | 4780 | void idle_task_exit(void) |
1da177e4 | 4781 | { |
48c5ccae | 4782 | struct mm_struct *mm = current->active_mm; |
e76bd8d9 | 4783 | |
48c5ccae | 4784 | BUG_ON(cpu_online(smp_processor_id())); |
e76bd8d9 | 4785 | |
a53efe5f | 4786 | if (mm != &init_mm) { |
48c5ccae | 4787 | switch_mm(mm, &init_mm, current); |
a53efe5f MS |
4788 | finish_arch_post_lock_switch(); |
4789 | } | |
48c5ccae | 4790 | mmdrop(mm); |
1da177e4 LT |
4791 | } |
4792 | ||
4793 | /* | |
5d180232 PZ |
4794 | * Since this CPU is going 'away' for a while, fold any nr_active delta |
4795 | * we might have. Assumes we're called after migrate_tasks() so that the | |
4796 | * nr_active count is stable. | |
4797 | * | |
4798 | * Also see the comment "Global load-average calculations". | |
1da177e4 | 4799 | */ |
5d180232 | 4800 | static void calc_load_migrate(struct rq *rq) |
1da177e4 | 4801 | { |
5d180232 PZ |
4802 | long delta = calc_load_fold_active(rq); |
4803 | if (delta) | |
4804 | atomic_long_add(delta, &calc_load_tasks); | |
1da177e4 LT |
4805 | } |
4806 | ||
3f1d2a31 PZ |
4807 | static void put_prev_task_fake(struct rq *rq, struct task_struct *prev) |
4808 | { | |
4809 | } | |
4810 | ||
4811 | static const struct sched_class fake_sched_class = { | |
4812 | .put_prev_task = put_prev_task_fake, | |
4813 | }; | |
4814 | ||
4815 | static struct task_struct fake_task = { | |
4816 | /* | |
4817 | * Avoid pull_{rt,dl}_task() | |
4818 | */ | |
4819 | .prio = MAX_PRIO + 1, | |
4820 | .sched_class = &fake_sched_class, | |
4821 | }; | |
4822 | ||
48f24c4d | 4823 | /* |
48c5ccae PZ |
4824 | * Migrate all tasks from the rq, sleeping tasks will be migrated by |
4825 | * try_to_wake_up()->select_task_rq(). | |
4826 | * | |
4827 | * Called with rq->lock held even though we'er in stop_machine() and | |
4828 | * there's no concurrency possible, we hold the required locks anyway | |
4829 | * because of lock validation efforts. | |
1da177e4 | 4830 | */ |
48c5ccae | 4831 | static void migrate_tasks(unsigned int dead_cpu) |
1da177e4 | 4832 | { |
70b97a7f | 4833 | struct rq *rq = cpu_rq(dead_cpu); |
48c5ccae PZ |
4834 | struct task_struct *next, *stop = rq->stop; |
4835 | int dest_cpu; | |
1da177e4 LT |
4836 | |
4837 | /* | |
48c5ccae PZ |
4838 | * Fudge the rq selection such that the below task selection loop |
4839 | * doesn't get stuck on the currently eligible stop task. | |
4840 | * | |
4841 | * We're currently inside stop_machine() and the rq is either stuck | |
4842 | * in the stop_machine_cpu_stop() loop, or we're executing this code, | |
4843 | * either way we should never end up calling schedule() until we're | |
4844 | * done here. | |
1da177e4 | 4845 | */ |
48c5ccae | 4846 | rq->stop = NULL; |
48f24c4d | 4847 | |
77bd3970 FW |
4848 | /* |
4849 | * put_prev_task() and pick_next_task() sched | |
4850 | * class method both need to have an up-to-date | |
4851 | * value of rq->clock[_task] | |
4852 | */ | |
4853 | update_rq_clock(rq); | |
4854 | ||
dd41f596 | 4855 | for ( ; ; ) { |
48c5ccae PZ |
4856 | /* |
4857 | * There's this thread running, bail when that's the only | |
4858 | * remaining thread. | |
4859 | */ | |
4860 | if (rq->nr_running == 1) | |
dd41f596 | 4861 | break; |
48c5ccae | 4862 | |
3f1d2a31 | 4863 | next = pick_next_task(rq, &fake_task); |
48c5ccae | 4864 | BUG_ON(!next); |
79c53799 | 4865 | next->sched_class->put_prev_task(rq, next); |
e692ab53 | 4866 | |
48c5ccae PZ |
4867 | /* Find suitable destination for @next, with force if needed. */ |
4868 | dest_cpu = select_fallback_rq(dead_cpu, next); | |
4869 | raw_spin_unlock(&rq->lock); | |
4870 | ||
4871 | __migrate_task(next, dead_cpu, dest_cpu); | |
4872 | ||
4873 | raw_spin_lock(&rq->lock); | |
1da177e4 | 4874 | } |
dce48a84 | 4875 | |
48c5ccae | 4876 | rq->stop = stop; |
dce48a84 | 4877 | } |
48c5ccae | 4878 | |
1da177e4 LT |
4879 | #endif /* CONFIG_HOTPLUG_CPU */ |
4880 | ||
e692ab53 NP |
4881 | #if defined(CONFIG_SCHED_DEBUG) && defined(CONFIG_SYSCTL) |
4882 | ||
4883 | static struct ctl_table sd_ctl_dir[] = { | |
e0361851 AD |
4884 | { |
4885 | .procname = "sched_domain", | |
c57baf1e | 4886 | .mode = 0555, |
e0361851 | 4887 | }, |
56992309 | 4888 | {} |
e692ab53 NP |
4889 | }; |
4890 | ||
4891 | static struct ctl_table sd_ctl_root[] = { | |
e0361851 AD |
4892 | { |
4893 | .procname = "kernel", | |
c57baf1e | 4894 | .mode = 0555, |
e0361851 AD |
4895 | .child = sd_ctl_dir, |
4896 | }, | |
56992309 | 4897 | {} |
e692ab53 NP |
4898 | }; |
4899 | ||
4900 | static struct ctl_table *sd_alloc_ctl_entry(int n) | |
4901 | { | |
4902 | struct ctl_table *entry = | |
5cf9f062 | 4903 | kcalloc(n, sizeof(struct ctl_table), GFP_KERNEL); |
e692ab53 | 4904 | |
e692ab53 NP |
4905 | return entry; |
4906 | } | |
4907 | ||
6382bc90 MM |
4908 | static void sd_free_ctl_entry(struct ctl_table **tablep) |
4909 | { | |
cd790076 | 4910 | struct ctl_table *entry; |
6382bc90 | 4911 | |
cd790076 MM |
4912 | /* |
4913 | * In the intermediate directories, both the child directory and | |
4914 | * procname are dynamically allocated and could fail but the mode | |
41a2d6cf | 4915 | * will always be set. In the lowest directory the names are |
cd790076 MM |
4916 | * static strings and all have proc handlers. |
4917 | */ | |
4918 | for (entry = *tablep; entry->mode; entry++) { | |
6382bc90 MM |
4919 | if (entry->child) |
4920 | sd_free_ctl_entry(&entry->child); | |
cd790076 MM |
4921 | if (entry->proc_handler == NULL) |
4922 | kfree(entry->procname); | |
4923 | } | |
6382bc90 MM |
4924 | |
4925 | kfree(*tablep); | |
4926 | *tablep = NULL; | |
4927 | } | |
4928 | ||
201c373e | 4929 | static int min_load_idx = 0; |
fd9b86d3 | 4930 | static int max_load_idx = CPU_LOAD_IDX_MAX-1; |
201c373e | 4931 | |
e692ab53 | 4932 | static void |
e0361851 | 4933 | set_table_entry(struct ctl_table *entry, |
e692ab53 | 4934 | const char *procname, void *data, int maxlen, |
201c373e NK |
4935 | umode_t mode, proc_handler *proc_handler, |
4936 | bool load_idx) | |
e692ab53 | 4937 | { |
e692ab53 NP |
4938 | entry->procname = procname; |
4939 | entry->data = data; | |
4940 | entry->maxlen = maxlen; | |
4941 | entry->mode = mode; | |
4942 | entry->proc_handler = proc_handler; | |
201c373e NK |
4943 | |
4944 | if (load_idx) { | |
4945 | entry->extra1 = &min_load_idx; | |
4946 | entry->extra2 = &max_load_idx; | |
4947 | } | |
e692ab53 NP |
4948 | } |
4949 | ||
4950 | static struct ctl_table * | |
4951 | sd_alloc_ctl_domain_table(struct sched_domain *sd) | |
4952 | { | |
37e6bae8 | 4953 | struct ctl_table *table = sd_alloc_ctl_entry(14); |
e692ab53 | 4954 | |
ad1cdc1d MM |
4955 | if (table == NULL) |
4956 | return NULL; | |
4957 | ||
e0361851 | 4958 | set_table_entry(&table[0], "min_interval", &sd->min_interval, |
201c373e | 4959 | sizeof(long), 0644, proc_doulongvec_minmax, false); |
e0361851 | 4960 | set_table_entry(&table[1], "max_interval", &sd->max_interval, |
201c373e | 4961 | sizeof(long), 0644, proc_doulongvec_minmax, false); |
e0361851 | 4962 | set_table_entry(&table[2], "busy_idx", &sd->busy_idx, |
201c373e | 4963 | sizeof(int), 0644, proc_dointvec_minmax, true); |
e0361851 | 4964 | set_table_entry(&table[3], "idle_idx", &sd->idle_idx, |
201c373e | 4965 | sizeof(int), 0644, proc_dointvec_minmax, true); |
e0361851 | 4966 | set_table_entry(&table[4], "newidle_idx", &sd->newidle_idx, |
201c373e | 4967 | sizeof(int), 0644, proc_dointvec_minmax, true); |
e0361851 | 4968 | set_table_entry(&table[5], "wake_idx", &sd->wake_idx, |
201c373e | 4969 | sizeof(int), 0644, proc_dointvec_minmax, true); |
e0361851 | 4970 | set_table_entry(&table[6], "forkexec_idx", &sd->forkexec_idx, |
201c373e | 4971 | sizeof(int), 0644, proc_dointvec_minmax, true); |
e0361851 | 4972 | set_table_entry(&table[7], "busy_factor", &sd->busy_factor, |
201c373e | 4973 | sizeof(int), 0644, proc_dointvec_minmax, false); |
e0361851 | 4974 | set_table_entry(&table[8], "imbalance_pct", &sd->imbalance_pct, |
201c373e | 4975 | sizeof(int), 0644, proc_dointvec_minmax, false); |
ace8b3d6 | 4976 | set_table_entry(&table[9], "cache_nice_tries", |
e692ab53 | 4977 | &sd->cache_nice_tries, |
201c373e | 4978 | sizeof(int), 0644, proc_dointvec_minmax, false); |
ace8b3d6 | 4979 | set_table_entry(&table[10], "flags", &sd->flags, |
201c373e | 4980 | sizeof(int), 0644, proc_dointvec_minmax, false); |
37e6bae8 AS |
4981 | set_table_entry(&table[11], "max_newidle_lb_cost", |
4982 | &sd->max_newidle_lb_cost, | |
4983 | sizeof(long), 0644, proc_doulongvec_minmax, false); | |
4984 | set_table_entry(&table[12], "name", sd->name, | |
201c373e | 4985 | CORENAME_MAX_SIZE, 0444, proc_dostring, false); |
37e6bae8 | 4986 | /* &table[13] is terminator */ |
e692ab53 NP |
4987 | |
4988 | return table; | |
4989 | } | |
4990 | ||
be7002e6 | 4991 | static struct ctl_table *sd_alloc_ctl_cpu_table(int cpu) |
e692ab53 NP |
4992 | { |
4993 | struct ctl_table *entry, *table; | |
4994 | struct sched_domain *sd; | |
4995 | int domain_num = 0, i; | |
4996 | char buf[32]; | |
4997 | ||
4998 | for_each_domain(cpu, sd) | |
4999 | domain_num++; | |
5000 | entry = table = sd_alloc_ctl_entry(domain_num + 1); | |
ad1cdc1d MM |
5001 | if (table == NULL) |
5002 | return NULL; | |
e692ab53 NP |
5003 | |
5004 | i = 0; | |
5005 | for_each_domain(cpu, sd) { | |
5006 | snprintf(buf, 32, "domain%d", i); | |
e692ab53 | 5007 | entry->procname = kstrdup(buf, GFP_KERNEL); |
c57baf1e | 5008 | entry->mode = 0555; |
e692ab53 NP |
5009 | entry->child = sd_alloc_ctl_domain_table(sd); |
5010 | entry++; | |
5011 | i++; | |
5012 | } | |
5013 | return table; | |
5014 | } | |
5015 | ||
5016 | static struct ctl_table_header *sd_sysctl_header; | |
6382bc90 | 5017 | static void register_sched_domain_sysctl(void) |
e692ab53 | 5018 | { |
6ad4c188 | 5019 | int i, cpu_num = num_possible_cpus(); |
e692ab53 NP |
5020 | struct ctl_table *entry = sd_alloc_ctl_entry(cpu_num + 1); |
5021 | char buf[32]; | |
5022 | ||
7378547f MM |
5023 | WARN_ON(sd_ctl_dir[0].child); |
5024 | sd_ctl_dir[0].child = entry; | |
5025 | ||
ad1cdc1d MM |
5026 | if (entry == NULL) |
5027 | return; | |
5028 | ||
6ad4c188 | 5029 | for_each_possible_cpu(i) { |
e692ab53 | 5030 | snprintf(buf, 32, "cpu%d", i); |
e692ab53 | 5031 | entry->procname = kstrdup(buf, GFP_KERNEL); |
c57baf1e | 5032 | entry->mode = 0555; |
e692ab53 | 5033 | entry->child = sd_alloc_ctl_cpu_table(i); |
97b6ea7b | 5034 | entry++; |
e692ab53 | 5035 | } |
7378547f MM |
5036 | |
5037 | WARN_ON(sd_sysctl_header); | |
e692ab53 NP |
5038 | sd_sysctl_header = register_sysctl_table(sd_ctl_root); |
5039 | } | |
6382bc90 | 5040 | |
7378547f | 5041 | /* may be called multiple times per register */ |
6382bc90 MM |
5042 | static void unregister_sched_domain_sysctl(void) |
5043 | { | |
7378547f MM |
5044 | if (sd_sysctl_header) |
5045 | unregister_sysctl_table(sd_sysctl_header); | |
6382bc90 | 5046 | sd_sysctl_header = NULL; |
7378547f MM |
5047 | if (sd_ctl_dir[0].child) |
5048 | sd_free_ctl_entry(&sd_ctl_dir[0].child); | |
6382bc90 | 5049 | } |
e692ab53 | 5050 | #else |
6382bc90 MM |
5051 | static void register_sched_domain_sysctl(void) |
5052 | { | |
5053 | } | |
5054 | static void unregister_sched_domain_sysctl(void) | |
e692ab53 NP |
5055 | { |
5056 | } | |
5057 | #endif | |
5058 | ||
1f11eb6a GH |
5059 | static void set_rq_online(struct rq *rq) |
5060 | { | |
5061 | if (!rq->online) { | |
5062 | const struct sched_class *class; | |
5063 | ||
c6c4927b | 5064 | cpumask_set_cpu(rq->cpu, rq->rd->online); |
1f11eb6a GH |
5065 | rq->online = 1; |
5066 | ||
5067 | for_each_class(class) { | |
5068 | if (class->rq_online) | |
5069 | class->rq_online(rq); | |
5070 | } | |
5071 | } | |
5072 | } | |
5073 | ||
5074 | static void set_rq_offline(struct rq *rq) | |
5075 | { | |
5076 | if (rq->online) { | |
5077 | const struct sched_class *class; | |
5078 | ||
5079 | for_each_class(class) { | |
5080 | if (class->rq_offline) | |
5081 | class->rq_offline(rq); | |
5082 | } | |
5083 | ||
c6c4927b | 5084 | cpumask_clear_cpu(rq->cpu, rq->rd->online); |
1f11eb6a GH |
5085 | rq->online = 0; |
5086 | } | |
5087 | } | |
5088 | ||
1da177e4 LT |
5089 | /* |
5090 | * migration_call - callback that gets triggered when a CPU is added. | |
5091 | * Here we can start up the necessary migration thread for the new CPU. | |
5092 | */ | |
0db0628d | 5093 | static int |
48f24c4d | 5094 | migration_call(struct notifier_block *nfb, unsigned long action, void *hcpu) |
1da177e4 | 5095 | { |
48f24c4d | 5096 | int cpu = (long)hcpu; |
1da177e4 | 5097 | unsigned long flags; |
969c7921 | 5098 | struct rq *rq = cpu_rq(cpu); |
1da177e4 | 5099 | |
48c5ccae | 5100 | switch (action & ~CPU_TASKS_FROZEN) { |
5be9361c | 5101 | |
1da177e4 | 5102 | case CPU_UP_PREPARE: |
a468d389 | 5103 | rq->calc_load_update = calc_load_update; |
1da177e4 | 5104 | break; |
48f24c4d | 5105 | |
1da177e4 | 5106 | case CPU_ONLINE: |
1f94ef59 | 5107 | /* Update our root-domain */ |
05fa785c | 5108 | raw_spin_lock_irqsave(&rq->lock, flags); |
1f94ef59 | 5109 | if (rq->rd) { |
c6c4927b | 5110 | BUG_ON(!cpumask_test_cpu(cpu, rq->rd->span)); |
1f11eb6a GH |
5111 | |
5112 | set_rq_online(rq); | |
1f94ef59 | 5113 | } |
05fa785c | 5114 | raw_spin_unlock_irqrestore(&rq->lock, flags); |
1da177e4 | 5115 | break; |
48f24c4d | 5116 | |
1da177e4 | 5117 | #ifdef CONFIG_HOTPLUG_CPU |
08f503b0 | 5118 | case CPU_DYING: |
317f3941 | 5119 | sched_ttwu_pending(); |
57d885fe | 5120 | /* Update our root-domain */ |
05fa785c | 5121 | raw_spin_lock_irqsave(&rq->lock, flags); |
57d885fe | 5122 | if (rq->rd) { |
c6c4927b | 5123 | BUG_ON(!cpumask_test_cpu(cpu, rq->rd->span)); |
1f11eb6a | 5124 | set_rq_offline(rq); |
57d885fe | 5125 | } |
48c5ccae PZ |
5126 | migrate_tasks(cpu); |
5127 | BUG_ON(rq->nr_running != 1); /* the migration thread */ | |
05fa785c | 5128 | raw_spin_unlock_irqrestore(&rq->lock, flags); |
5d180232 | 5129 | break; |
48c5ccae | 5130 | |
5d180232 | 5131 | case CPU_DEAD: |
f319da0c | 5132 | calc_load_migrate(rq); |
57d885fe | 5133 | break; |
1da177e4 LT |
5134 | #endif |
5135 | } | |
49c022e6 PZ |
5136 | |
5137 | update_max_interval(); | |
5138 | ||
1da177e4 LT |
5139 | return NOTIFY_OK; |
5140 | } | |
5141 | ||
f38b0820 PM |
5142 | /* |
5143 | * Register at high priority so that task migration (migrate_all_tasks) | |
5144 | * happens before everything else. This has to be lower priority than | |
cdd6c482 | 5145 | * the notifier in the perf_event subsystem, though. |
1da177e4 | 5146 | */ |
0db0628d | 5147 | static struct notifier_block migration_notifier = { |
1da177e4 | 5148 | .notifier_call = migration_call, |
50a323b7 | 5149 | .priority = CPU_PRI_MIGRATION, |
1da177e4 LT |
5150 | }; |
5151 | ||
a803f026 CM |
5152 | static void __cpuinit set_cpu_rq_start_time(void) |
5153 | { | |
5154 | int cpu = smp_processor_id(); | |
5155 | struct rq *rq = cpu_rq(cpu); | |
5156 | rq->age_stamp = sched_clock_cpu(cpu); | |
5157 | } | |
5158 | ||
0db0628d | 5159 | static int sched_cpu_active(struct notifier_block *nfb, |
3a101d05 TH |
5160 | unsigned long action, void *hcpu) |
5161 | { | |
5162 | switch (action & ~CPU_TASKS_FROZEN) { | |
a803f026 CM |
5163 | case CPU_STARTING: |
5164 | set_cpu_rq_start_time(); | |
5165 | return NOTIFY_OK; | |
3a101d05 TH |
5166 | case CPU_DOWN_FAILED: |
5167 | set_cpu_active((long)hcpu, true); | |
5168 | return NOTIFY_OK; | |
5169 | default: | |
5170 | return NOTIFY_DONE; | |
5171 | } | |
5172 | } | |
5173 | ||
0db0628d | 5174 | static int sched_cpu_inactive(struct notifier_block *nfb, |
3a101d05 TH |
5175 | unsigned long action, void *hcpu) |
5176 | { | |
de212f18 PZ |
5177 | unsigned long flags; |
5178 | long cpu = (long)hcpu; | |
5179 | ||
3a101d05 TH |
5180 | switch (action & ~CPU_TASKS_FROZEN) { |
5181 | case CPU_DOWN_PREPARE: | |
de212f18 PZ |
5182 | set_cpu_active(cpu, false); |
5183 | ||
5184 | /* explicitly allow suspend */ | |
5185 | if (!(action & CPU_TASKS_FROZEN)) { | |
5186 | struct dl_bw *dl_b = dl_bw_of(cpu); | |
5187 | bool overflow; | |
5188 | int cpus; | |
5189 | ||
5190 | raw_spin_lock_irqsave(&dl_b->lock, flags); | |
5191 | cpus = dl_bw_cpus(cpu); | |
5192 | overflow = __dl_overflow(dl_b, cpus, 0, 0); | |
5193 | raw_spin_unlock_irqrestore(&dl_b->lock, flags); | |
5194 | ||
5195 | if (overflow) | |
5196 | return notifier_from_errno(-EBUSY); | |
5197 | } | |
3a101d05 | 5198 | return NOTIFY_OK; |
3a101d05 | 5199 | } |
de212f18 PZ |
5200 | |
5201 | return NOTIFY_DONE; | |
3a101d05 TH |
5202 | } |
5203 | ||
7babe8db | 5204 | static int __init migration_init(void) |
1da177e4 LT |
5205 | { |
5206 | void *cpu = (void *)(long)smp_processor_id(); | |
07dccf33 | 5207 | int err; |
48f24c4d | 5208 | |
3a101d05 | 5209 | /* Initialize migration for the boot CPU */ |
07dccf33 AM |
5210 | err = migration_call(&migration_notifier, CPU_UP_PREPARE, cpu); |
5211 | BUG_ON(err == NOTIFY_BAD); | |
1da177e4 LT |
5212 | migration_call(&migration_notifier, CPU_ONLINE, cpu); |
5213 | register_cpu_notifier(&migration_notifier); | |
7babe8db | 5214 | |
3a101d05 TH |
5215 | /* Register cpu active notifiers */ |
5216 | cpu_notifier(sched_cpu_active, CPU_PRI_SCHED_ACTIVE); | |
5217 | cpu_notifier(sched_cpu_inactive, CPU_PRI_SCHED_INACTIVE); | |
5218 | ||
a004cd42 | 5219 | return 0; |
1da177e4 | 5220 | } |
7babe8db | 5221 | early_initcall(migration_init); |
1da177e4 LT |
5222 | #endif |
5223 | ||
5224 | #ifdef CONFIG_SMP | |
476f3534 | 5225 | |
4cb98839 PZ |
5226 | static cpumask_var_t sched_domains_tmpmask; /* sched_domains_mutex */ |
5227 | ||
3e9830dc | 5228 | #ifdef CONFIG_SCHED_DEBUG |
4dcf6aff | 5229 | |
d039ac60 | 5230 | static __read_mostly int sched_debug_enabled; |
f6630114 | 5231 | |
d039ac60 | 5232 | static int __init sched_debug_setup(char *str) |
f6630114 | 5233 | { |
d039ac60 | 5234 | sched_debug_enabled = 1; |
f6630114 MT |
5235 | |
5236 | return 0; | |
5237 | } | |
d039ac60 PZ |
5238 | early_param("sched_debug", sched_debug_setup); |
5239 | ||
5240 | static inline bool sched_debug(void) | |
5241 | { | |
5242 | return sched_debug_enabled; | |
5243 | } | |
f6630114 | 5244 | |
7c16ec58 | 5245 | static int sched_domain_debug_one(struct sched_domain *sd, int cpu, int level, |
96f874e2 | 5246 | struct cpumask *groupmask) |
1da177e4 | 5247 | { |
4dcf6aff | 5248 | struct sched_group *group = sd->groups; |
434d53b0 | 5249 | char str[256]; |
1da177e4 | 5250 | |
968ea6d8 | 5251 | cpulist_scnprintf(str, sizeof(str), sched_domain_span(sd)); |
96f874e2 | 5252 | cpumask_clear(groupmask); |
4dcf6aff IM |
5253 | |
5254 | printk(KERN_DEBUG "%*s domain %d: ", level, "", level); | |
5255 | ||
5256 | if (!(sd->flags & SD_LOAD_BALANCE)) { | |
3df0fc5b | 5257 | printk("does not load-balance\n"); |
4dcf6aff | 5258 | if (sd->parent) |
3df0fc5b PZ |
5259 | printk(KERN_ERR "ERROR: !SD_LOAD_BALANCE domain" |
5260 | " has parent"); | |
4dcf6aff | 5261 | return -1; |
41c7ce9a NP |
5262 | } |
5263 | ||
3df0fc5b | 5264 | printk(KERN_CONT "span %s level %s\n", str, sd->name); |
4dcf6aff | 5265 | |
758b2cdc | 5266 | if (!cpumask_test_cpu(cpu, sched_domain_span(sd))) { |
3df0fc5b PZ |
5267 | printk(KERN_ERR "ERROR: domain->span does not contain " |
5268 | "CPU%d\n", cpu); | |
4dcf6aff | 5269 | } |
758b2cdc | 5270 | if (!cpumask_test_cpu(cpu, sched_group_cpus(group))) { |
3df0fc5b PZ |
5271 | printk(KERN_ERR "ERROR: domain->groups does not contain" |
5272 | " CPU%d\n", cpu); | |
4dcf6aff | 5273 | } |
1da177e4 | 5274 | |
4dcf6aff | 5275 | printk(KERN_DEBUG "%*s groups:", level + 1, ""); |
1da177e4 | 5276 | do { |
4dcf6aff | 5277 | if (!group) { |
3df0fc5b PZ |
5278 | printk("\n"); |
5279 | printk(KERN_ERR "ERROR: group is NULL\n"); | |
1da177e4 LT |
5280 | break; |
5281 | } | |
5282 | ||
c3decf0d | 5283 | /* |
63b2ca30 NP |
5284 | * Even though we initialize ->capacity to something semi-sane, |
5285 | * we leave capacity_orig unset. This allows us to detect if | |
c3decf0d PZ |
5286 | * domain iteration is still funny without causing /0 traps. |
5287 | */ | |
63b2ca30 | 5288 | if (!group->sgc->capacity_orig) { |
3df0fc5b | 5289 | printk(KERN_CONT "\n"); |
63b2ca30 | 5290 | printk(KERN_ERR "ERROR: domain->cpu_capacity not set\n"); |
4dcf6aff IM |
5291 | break; |
5292 | } | |
1da177e4 | 5293 | |
758b2cdc | 5294 | if (!cpumask_weight(sched_group_cpus(group))) { |
3df0fc5b PZ |
5295 | printk(KERN_CONT "\n"); |
5296 | printk(KERN_ERR "ERROR: empty group\n"); | |
4dcf6aff IM |
5297 | break; |
5298 | } | |
1da177e4 | 5299 | |
cb83b629 PZ |
5300 | if (!(sd->flags & SD_OVERLAP) && |
5301 | cpumask_intersects(groupmask, sched_group_cpus(group))) { | |
3df0fc5b PZ |
5302 | printk(KERN_CONT "\n"); |
5303 | printk(KERN_ERR "ERROR: repeated CPUs\n"); | |
4dcf6aff IM |
5304 | break; |
5305 | } | |
1da177e4 | 5306 | |
758b2cdc | 5307 | cpumask_or(groupmask, groupmask, sched_group_cpus(group)); |
1da177e4 | 5308 | |
968ea6d8 | 5309 | cpulist_scnprintf(str, sizeof(str), sched_group_cpus(group)); |
381512cf | 5310 | |
3df0fc5b | 5311 | printk(KERN_CONT " %s", str); |
ca8ce3d0 | 5312 | if (group->sgc->capacity != SCHED_CAPACITY_SCALE) { |
63b2ca30 NP |
5313 | printk(KERN_CONT " (cpu_capacity = %d)", |
5314 | group->sgc->capacity); | |
381512cf | 5315 | } |
1da177e4 | 5316 | |
4dcf6aff IM |
5317 | group = group->next; |
5318 | } while (group != sd->groups); | |
3df0fc5b | 5319 | printk(KERN_CONT "\n"); |
1da177e4 | 5320 | |
758b2cdc | 5321 | if (!cpumask_equal(sched_domain_span(sd), groupmask)) |
3df0fc5b | 5322 | printk(KERN_ERR "ERROR: groups don't span domain->span\n"); |
1da177e4 | 5323 | |
758b2cdc RR |
5324 | if (sd->parent && |
5325 | !cpumask_subset(groupmask, sched_domain_span(sd->parent))) | |
3df0fc5b PZ |
5326 | printk(KERN_ERR "ERROR: parent span is not a superset " |
5327 | "of domain->span\n"); | |
4dcf6aff IM |
5328 | return 0; |
5329 | } | |
1da177e4 | 5330 | |
4dcf6aff IM |
5331 | static void sched_domain_debug(struct sched_domain *sd, int cpu) |
5332 | { | |
5333 | int level = 0; | |
1da177e4 | 5334 | |
d039ac60 | 5335 | if (!sched_debug_enabled) |
f6630114 MT |
5336 | return; |
5337 | ||
4dcf6aff IM |
5338 | if (!sd) { |
5339 | printk(KERN_DEBUG "CPU%d attaching NULL sched-domain.\n", cpu); | |
5340 | return; | |
5341 | } | |
1da177e4 | 5342 | |
4dcf6aff IM |
5343 | printk(KERN_DEBUG "CPU%d attaching sched-domain:\n", cpu); |
5344 | ||
5345 | for (;;) { | |
4cb98839 | 5346 | if (sched_domain_debug_one(sd, cpu, level, sched_domains_tmpmask)) |
4dcf6aff | 5347 | break; |
1da177e4 LT |
5348 | level++; |
5349 | sd = sd->parent; | |
33859f7f | 5350 | if (!sd) |
4dcf6aff IM |
5351 | break; |
5352 | } | |
1da177e4 | 5353 | } |
6d6bc0ad | 5354 | #else /* !CONFIG_SCHED_DEBUG */ |
48f24c4d | 5355 | # define sched_domain_debug(sd, cpu) do { } while (0) |
d039ac60 PZ |
5356 | static inline bool sched_debug(void) |
5357 | { | |
5358 | return false; | |
5359 | } | |
6d6bc0ad | 5360 | #endif /* CONFIG_SCHED_DEBUG */ |
1da177e4 | 5361 | |
1a20ff27 | 5362 | static int sd_degenerate(struct sched_domain *sd) |
245af2c7 | 5363 | { |
758b2cdc | 5364 | if (cpumask_weight(sched_domain_span(sd)) == 1) |
245af2c7 SS |
5365 | return 1; |
5366 | ||
5367 | /* Following flags need at least 2 groups */ | |
5368 | if (sd->flags & (SD_LOAD_BALANCE | | |
5369 | SD_BALANCE_NEWIDLE | | |
5370 | SD_BALANCE_FORK | | |
89c4710e | 5371 | SD_BALANCE_EXEC | |
5d4dfddd | 5372 | SD_SHARE_CPUCAPACITY | |
d77b3ed5 VG |
5373 | SD_SHARE_PKG_RESOURCES | |
5374 | SD_SHARE_POWERDOMAIN)) { | |
245af2c7 SS |
5375 | if (sd->groups != sd->groups->next) |
5376 | return 0; | |
5377 | } | |
5378 | ||
5379 | /* Following flags don't use groups */ | |
c88d5910 | 5380 | if (sd->flags & (SD_WAKE_AFFINE)) |
245af2c7 SS |
5381 | return 0; |
5382 | ||
5383 | return 1; | |
5384 | } | |
5385 | ||
48f24c4d IM |
5386 | static int |
5387 | sd_parent_degenerate(struct sched_domain *sd, struct sched_domain *parent) | |
245af2c7 SS |
5388 | { |
5389 | unsigned long cflags = sd->flags, pflags = parent->flags; | |
5390 | ||
5391 | if (sd_degenerate(parent)) | |
5392 | return 1; | |
5393 | ||
758b2cdc | 5394 | if (!cpumask_equal(sched_domain_span(sd), sched_domain_span(parent))) |
245af2c7 SS |
5395 | return 0; |
5396 | ||
245af2c7 SS |
5397 | /* Flags needing groups don't count if only 1 group in parent */ |
5398 | if (parent->groups == parent->groups->next) { | |
5399 | pflags &= ~(SD_LOAD_BALANCE | | |
5400 | SD_BALANCE_NEWIDLE | | |
5401 | SD_BALANCE_FORK | | |
89c4710e | 5402 | SD_BALANCE_EXEC | |
5d4dfddd | 5403 | SD_SHARE_CPUCAPACITY | |
10866e62 | 5404 | SD_SHARE_PKG_RESOURCES | |
d77b3ed5 VG |
5405 | SD_PREFER_SIBLING | |
5406 | SD_SHARE_POWERDOMAIN); | |
5436499e KC |
5407 | if (nr_node_ids == 1) |
5408 | pflags &= ~SD_SERIALIZE; | |
245af2c7 SS |
5409 | } |
5410 | if (~cflags & pflags) | |
5411 | return 0; | |
5412 | ||
5413 | return 1; | |
5414 | } | |
5415 | ||
dce840a0 | 5416 | static void free_rootdomain(struct rcu_head *rcu) |
c6c4927b | 5417 | { |
dce840a0 | 5418 | struct root_domain *rd = container_of(rcu, struct root_domain, rcu); |
047106ad | 5419 | |
68e74568 | 5420 | cpupri_cleanup(&rd->cpupri); |
6bfd6d72 | 5421 | cpudl_cleanup(&rd->cpudl); |
1baca4ce | 5422 | free_cpumask_var(rd->dlo_mask); |
c6c4927b RR |
5423 | free_cpumask_var(rd->rto_mask); |
5424 | free_cpumask_var(rd->online); | |
5425 | free_cpumask_var(rd->span); | |
5426 | kfree(rd); | |
5427 | } | |
5428 | ||
57d885fe GH |
5429 | static void rq_attach_root(struct rq *rq, struct root_domain *rd) |
5430 | { | |
a0490fa3 | 5431 | struct root_domain *old_rd = NULL; |
57d885fe | 5432 | unsigned long flags; |
57d885fe | 5433 | |
05fa785c | 5434 | raw_spin_lock_irqsave(&rq->lock, flags); |
57d885fe GH |
5435 | |
5436 | if (rq->rd) { | |
a0490fa3 | 5437 | old_rd = rq->rd; |
57d885fe | 5438 | |
c6c4927b | 5439 | if (cpumask_test_cpu(rq->cpu, old_rd->online)) |
1f11eb6a | 5440 | set_rq_offline(rq); |
57d885fe | 5441 | |
c6c4927b | 5442 | cpumask_clear_cpu(rq->cpu, old_rd->span); |
dc938520 | 5443 | |
a0490fa3 | 5444 | /* |
0515973f | 5445 | * If we dont want to free the old_rd yet then |
a0490fa3 IM |
5446 | * set old_rd to NULL to skip the freeing later |
5447 | * in this function: | |
5448 | */ | |
5449 | if (!atomic_dec_and_test(&old_rd->refcount)) | |
5450 | old_rd = NULL; | |
57d885fe GH |
5451 | } |
5452 | ||
5453 | atomic_inc(&rd->refcount); | |
5454 | rq->rd = rd; | |
5455 | ||
c6c4927b | 5456 | cpumask_set_cpu(rq->cpu, rd->span); |
00aec93d | 5457 | if (cpumask_test_cpu(rq->cpu, cpu_active_mask)) |
1f11eb6a | 5458 | set_rq_online(rq); |
57d885fe | 5459 | |
05fa785c | 5460 | raw_spin_unlock_irqrestore(&rq->lock, flags); |
a0490fa3 IM |
5461 | |
5462 | if (old_rd) | |
dce840a0 | 5463 | call_rcu_sched(&old_rd->rcu, free_rootdomain); |
57d885fe GH |
5464 | } |
5465 | ||
68c38fc3 | 5466 | static int init_rootdomain(struct root_domain *rd) |
57d885fe GH |
5467 | { |
5468 | memset(rd, 0, sizeof(*rd)); | |
5469 | ||
68c38fc3 | 5470 | if (!alloc_cpumask_var(&rd->span, GFP_KERNEL)) |
0c910d28 | 5471 | goto out; |
68c38fc3 | 5472 | if (!alloc_cpumask_var(&rd->online, GFP_KERNEL)) |
c6c4927b | 5473 | goto free_span; |
1baca4ce | 5474 | if (!alloc_cpumask_var(&rd->dlo_mask, GFP_KERNEL)) |
c6c4927b | 5475 | goto free_online; |
1baca4ce JL |
5476 | if (!alloc_cpumask_var(&rd->rto_mask, GFP_KERNEL)) |
5477 | goto free_dlo_mask; | |
6e0534f2 | 5478 | |
332ac17e | 5479 | init_dl_bw(&rd->dl_bw); |
6bfd6d72 JL |
5480 | if (cpudl_init(&rd->cpudl) != 0) |
5481 | goto free_dlo_mask; | |
332ac17e | 5482 | |
68c38fc3 | 5483 | if (cpupri_init(&rd->cpupri) != 0) |
68e74568 | 5484 | goto free_rto_mask; |
c6c4927b | 5485 | return 0; |
6e0534f2 | 5486 | |
68e74568 RR |
5487 | free_rto_mask: |
5488 | free_cpumask_var(rd->rto_mask); | |
1baca4ce JL |
5489 | free_dlo_mask: |
5490 | free_cpumask_var(rd->dlo_mask); | |
c6c4927b RR |
5491 | free_online: |
5492 | free_cpumask_var(rd->online); | |
5493 | free_span: | |
5494 | free_cpumask_var(rd->span); | |
0c910d28 | 5495 | out: |
c6c4927b | 5496 | return -ENOMEM; |
57d885fe GH |
5497 | } |
5498 | ||
029632fb PZ |
5499 | /* |
5500 | * By default the system creates a single root-domain with all cpus as | |
5501 | * members (mimicking the global state we have today). | |
5502 | */ | |
5503 | struct root_domain def_root_domain; | |
5504 | ||
57d885fe GH |
5505 | static void init_defrootdomain(void) |
5506 | { | |
68c38fc3 | 5507 | init_rootdomain(&def_root_domain); |
c6c4927b | 5508 | |
57d885fe GH |
5509 | atomic_set(&def_root_domain.refcount, 1); |
5510 | } | |
5511 | ||
dc938520 | 5512 | static struct root_domain *alloc_rootdomain(void) |
57d885fe GH |
5513 | { |
5514 | struct root_domain *rd; | |
5515 | ||
5516 | rd = kmalloc(sizeof(*rd), GFP_KERNEL); | |
5517 | if (!rd) | |
5518 | return NULL; | |
5519 | ||
68c38fc3 | 5520 | if (init_rootdomain(rd) != 0) { |
c6c4927b RR |
5521 | kfree(rd); |
5522 | return NULL; | |
5523 | } | |
57d885fe GH |
5524 | |
5525 | return rd; | |
5526 | } | |
5527 | ||
63b2ca30 | 5528 | static void free_sched_groups(struct sched_group *sg, int free_sgc) |
e3589f6c PZ |
5529 | { |
5530 | struct sched_group *tmp, *first; | |
5531 | ||
5532 | if (!sg) | |
5533 | return; | |
5534 | ||
5535 | first = sg; | |
5536 | do { | |
5537 | tmp = sg->next; | |
5538 | ||
63b2ca30 NP |
5539 | if (free_sgc && atomic_dec_and_test(&sg->sgc->ref)) |
5540 | kfree(sg->sgc); | |
e3589f6c PZ |
5541 | |
5542 | kfree(sg); | |
5543 | sg = tmp; | |
5544 | } while (sg != first); | |
5545 | } | |
5546 | ||
dce840a0 PZ |
5547 | static void free_sched_domain(struct rcu_head *rcu) |
5548 | { | |
5549 | struct sched_domain *sd = container_of(rcu, struct sched_domain, rcu); | |
e3589f6c PZ |
5550 | |
5551 | /* | |
5552 | * If its an overlapping domain it has private groups, iterate and | |
5553 | * nuke them all. | |
5554 | */ | |
5555 | if (sd->flags & SD_OVERLAP) { | |
5556 | free_sched_groups(sd->groups, 1); | |
5557 | } else if (atomic_dec_and_test(&sd->groups->ref)) { | |
63b2ca30 | 5558 | kfree(sd->groups->sgc); |
dce840a0 | 5559 | kfree(sd->groups); |
9c3f75cb | 5560 | } |
dce840a0 PZ |
5561 | kfree(sd); |
5562 | } | |
5563 | ||
5564 | static void destroy_sched_domain(struct sched_domain *sd, int cpu) | |
5565 | { | |
5566 | call_rcu(&sd->rcu, free_sched_domain); | |
5567 | } | |
5568 | ||
5569 | static void destroy_sched_domains(struct sched_domain *sd, int cpu) | |
5570 | { | |
5571 | for (; sd; sd = sd->parent) | |
5572 | destroy_sched_domain(sd, cpu); | |
5573 | } | |
5574 | ||
518cd623 PZ |
5575 | /* |
5576 | * Keep a special pointer to the highest sched_domain that has | |
5577 | * SD_SHARE_PKG_RESOURCE set (Last Level Cache Domain) for this | |
5578 | * allows us to avoid some pointer chasing select_idle_sibling(). | |
5579 | * | |
5580 | * Also keep a unique ID per domain (we use the first cpu number in | |
5581 | * the cpumask of the domain), this allows us to quickly tell if | |
39be3501 | 5582 | * two cpus are in the same cache domain, see cpus_share_cache(). |
518cd623 PZ |
5583 | */ |
5584 | DEFINE_PER_CPU(struct sched_domain *, sd_llc); | |
7d9ffa89 | 5585 | DEFINE_PER_CPU(int, sd_llc_size); |
518cd623 | 5586 | DEFINE_PER_CPU(int, sd_llc_id); |
fb13c7ee | 5587 | DEFINE_PER_CPU(struct sched_domain *, sd_numa); |
37dc6b50 PM |
5588 | DEFINE_PER_CPU(struct sched_domain *, sd_busy); |
5589 | DEFINE_PER_CPU(struct sched_domain *, sd_asym); | |
518cd623 PZ |
5590 | |
5591 | static void update_top_cache_domain(int cpu) | |
5592 | { | |
5593 | struct sched_domain *sd; | |
5d4cf996 | 5594 | struct sched_domain *busy_sd = NULL; |
518cd623 | 5595 | int id = cpu; |
7d9ffa89 | 5596 | int size = 1; |
518cd623 PZ |
5597 | |
5598 | sd = highest_flag_domain(cpu, SD_SHARE_PKG_RESOURCES); | |
7d9ffa89 | 5599 | if (sd) { |
518cd623 | 5600 | id = cpumask_first(sched_domain_span(sd)); |
7d9ffa89 | 5601 | size = cpumask_weight(sched_domain_span(sd)); |
5d4cf996 | 5602 | busy_sd = sd->parent; /* sd_busy */ |
7d9ffa89 | 5603 | } |
5d4cf996 | 5604 | rcu_assign_pointer(per_cpu(sd_busy, cpu), busy_sd); |
518cd623 PZ |
5605 | |
5606 | rcu_assign_pointer(per_cpu(sd_llc, cpu), sd); | |
7d9ffa89 | 5607 | per_cpu(sd_llc_size, cpu) = size; |
518cd623 | 5608 | per_cpu(sd_llc_id, cpu) = id; |
fb13c7ee MG |
5609 | |
5610 | sd = lowest_flag_domain(cpu, SD_NUMA); | |
5611 | rcu_assign_pointer(per_cpu(sd_numa, cpu), sd); | |
37dc6b50 PM |
5612 | |
5613 | sd = highest_flag_domain(cpu, SD_ASYM_PACKING); | |
5614 | rcu_assign_pointer(per_cpu(sd_asym, cpu), sd); | |
518cd623 PZ |
5615 | } |
5616 | ||
1da177e4 | 5617 | /* |
0eab9146 | 5618 | * Attach the domain 'sd' to 'cpu' as its base domain. Callers must |
1da177e4 LT |
5619 | * hold the hotplug lock. |
5620 | */ | |
0eab9146 IM |
5621 | static void |
5622 | cpu_attach_domain(struct sched_domain *sd, struct root_domain *rd, int cpu) | |
1da177e4 | 5623 | { |
70b97a7f | 5624 | struct rq *rq = cpu_rq(cpu); |
245af2c7 SS |
5625 | struct sched_domain *tmp; |
5626 | ||
5627 | /* Remove the sched domains which do not contribute to scheduling. */ | |
f29c9b1c | 5628 | for (tmp = sd; tmp; ) { |
245af2c7 SS |
5629 | struct sched_domain *parent = tmp->parent; |
5630 | if (!parent) | |
5631 | break; | |
f29c9b1c | 5632 | |
1a848870 | 5633 | if (sd_parent_degenerate(tmp, parent)) { |
245af2c7 | 5634 | tmp->parent = parent->parent; |
1a848870 SS |
5635 | if (parent->parent) |
5636 | parent->parent->child = tmp; | |
10866e62 PZ |
5637 | /* |
5638 | * Transfer SD_PREFER_SIBLING down in case of a | |
5639 | * degenerate parent; the spans match for this | |
5640 | * so the property transfers. | |
5641 | */ | |
5642 | if (parent->flags & SD_PREFER_SIBLING) | |
5643 | tmp->flags |= SD_PREFER_SIBLING; | |
dce840a0 | 5644 | destroy_sched_domain(parent, cpu); |
f29c9b1c LZ |
5645 | } else |
5646 | tmp = tmp->parent; | |
245af2c7 SS |
5647 | } |
5648 | ||
1a848870 | 5649 | if (sd && sd_degenerate(sd)) { |
dce840a0 | 5650 | tmp = sd; |
245af2c7 | 5651 | sd = sd->parent; |
dce840a0 | 5652 | destroy_sched_domain(tmp, cpu); |
1a848870 SS |
5653 | if (sd) |
5654 | sd->child = NULL; | |
5655 | } | |
1da177e4 | 5656 | |
4cb98839 | 5657 | sched_domain_debug(sd, cpu); |
1da177e4 | 5658 | |
57d885fe | 5659 | rq_attach_root(rq, rd); |
dce840a0 | 5660 | tmp = rq->sd; |
674311d5 | 5661 | rcu_assign_pointer(rq->sd, sd); |
dce840a0 | 5662 | destroy_sched_domains(tmp, cpu); |
518cd623 PZ |
5663 | |
5664 | update_top_cache_domain(cpu); | |
1da177e4 LT |
5665 | } |
5666 | ||
5667 | /* cpus with isolated domains */ | |
dcc30a35 | 5668 | static cpumask_var_t cpu_isolated_map; |
1da177e4 LT |
5669 | |
5670 | /* Setup the mask of cpus configured for isolated domains */ | |
5671 | static int __init isolated_cpu_setup(char *str) | |
5672 | { | |
bdddd296 | 5673 | alloc_bootmem_cpumask_var(&cpu_isolated_map); |
968ea6d8 | 5674 | cpulist_parse(str, cpu_isolated_map); |
1da177e4 LT |
5675 | return 1; |
5676 | } | |
5677 | ||
8927f494 | 5678 | __setup("isolcpus=", isolated_cpu_setup); |
1da177e4 | 5679 | |
49a02c51 | 5680 | struct s_data { |
21d42ccf | 5681 | struct sched_domain ** __percpu sd; |
49a02c51 AH |
5682 | struct root_domain *rd; |
5683 | }; | |
5684 | ||
2109b99e | 5685 | enum s_alloc { |
2109b99e | 5686 | sa_rootdomain, |
21d42ccf | 5687 | sa_sd, |
dce840a0 | 5688 | sa_sd_storage, |
2109b99e AH |
5689 | sa_none, |
5690 | }; | |
5691 | ||
c1174876 PZ |
5692 | /* |
5693 | * Build an iteration mask that can exclude certain CPUs from the upwards | |
5694 | * domain traversal. | |
5695 | * | |
5696 | * Asymmetric node setups can result in situations where the domain tree is of | |
5697 | * unequal depth, make sure to skip domains that already cover the entire | |
5698 | * range. | |
5699 | * | |
5700 | * In that case build_sched_domains() will have terminated the iteration early | |
5701 | * and our sibling sd spans will be empty. Domains should always include the | |
5702 | * cpu they're built on, so check that. | |
5703 | * | |
5704 | */ | |
5705 | static void build_group_mask(struct sched_domain *sd, struct sched_group *sg) | |
5706 | { | |
5707 | const struct cpumask *span = sched_domain_span(sd); | |
5708 | struct sd_data *sdd = sd->private; | |
5709 | struct sched_domain *sibling; | |
5710 | int i; | |
5711 | ||
5712 | for_each_cpu(i, span) { | |
5713 | sibling = *per_cpu_ptr(sdd->sd, i); | |
5714 | if (!cpumask_test_cpu(i, sched_domain_span(sibling))) | |
5715 | continue; | |
5716 | ||
5717 | cpumask_set_cpu(i, sched_group_mask(sg)); | |
5718 | } | |
5719 | } | |
5720 | ||
5721 | /* | |
5722 | * Return the canonical balance cpu for this group, this is the first cpu | |
5723 | * of this group that's also in the iteration mask. | |
5724 | */ | |
5725 | int group_balance_cpu(struct sched_group *sg) | |
5726 | { | |
5727 | return cpumask_first_and(sched_group_cpus(sg), sched_group_mask(sg)); | |
5728 | } | |
5729 | ||
e3589f6c PZ |
5730 | static int |
5731 | build_overlap_sched_groups(struct sched_domain *sd, int cpu) | |
5732 | { | |
5733 | struct sched_group *first = NULL, *last = NULL, *groups = NULL, *sg; | |
5734 | const struct cpumask *span = sched_domain_span(sd); | |
5735 | struct cpumask *covered = sched_domains_tmpmask; | |
5736 | struct sd_data *sdd = sd->private; | |
5737 | struct sched_domain *child; | |
5738 | int i; | |
5739 | ||
5740 | cpumask_clear(covered); | |
5741 | ||
5742 | for_each_cpu(i, span) { | |
5743 | struct cpumask *sg_span; | |
5744 | ||
5745 | if (cpumask_test_cpu(i, covered)) | |
5746 | continue; | |
5747 | ||
c1174876 PZ |
5748 | child = *per_cpu_ptr(sdd->sd, i); |
5749 | ||
5750 | /* See the comment near build_group_mask(). */ | |
5751 | if (!cpumask_test_cpu(i, sched_domain_span(child))) | |
5752 | continue; | |
5753 | ||
e3589f6c | 5754 | sg = kzalloc_node(sizeof(struct sched_group) + cpumask_size(), |
4d78a223 | 5755 | GFP_KERNEL, cpu_to_node(cpu)); |
e3589f6c PZ |
5756 | |
5757 | if (!sg) | |
5758 | goto fail; | |
5759 | ||
5760 | sg_span = sched_group_cpus(sg); | |
e3589f6c PZ |
5761 | if (child->child) { |
5762 | child = child->child; | |
5763 | cpumask_copy(sg_span, sched_domain_span(child)); | |
5764 | } else | |
5765 | cpumask_set_cpu(i, sg_span); | |
5766 | ||
5767 | cpumask_or(covered, covered, sg_span); | |
5768 | ||
63b2ca30 NP |
5769 | sg->sgc = *per_cpu_ptr(sdd->sgc, i); |
5770 | if (atomic_inc_return(&sg->sgc->ref) == 1) | |
c1174876 PZ |
5771 | build_group_mask(sd, sg); |
5772 | ||
c3decf0d | 5773 | /* |
63b2ca30 | 5774 | * Initialize sgc->capacity such that even if we mess up the |
c3decf0d PZ |
5775 | * domains and no possible iteration will get us here, we won't |
5776 | * die on a /0 trap. | |
5777 | */ | |
ca8ce3d0 | 5778 | sg->sgc->capacity = SCHED_CAPACITY_SCALE * cpumask_weight(sg_span); |
63b2ca30 | 5779 | sg->sgc->capacity_orig = sg->sgc->capacity; |
e3589f6c | 5780 | |
c1174876 PZ |
5781 | /* |
5782 | * Make sure the first group of this domain contains the | |
5783 | * canonical balance cpu. Otherwise the sched_domain iteration | |
5784 | * breaks. See update_sg_lb_stats(). | |
5785 | */ | |
74a5ce20 | 5786 | if ((!groups && cpumask_test_cpu(cpu, sg_span)) || |
c1174876 | 5787 | group_balance_cpu(sg) == cpu) |
e3589f6c PZ |
5788 | groups = sg; |
5789 | ||
5790 | if (!first) | |
5791 | first = sg; | |
5792 | if (last) | |
5793 | last->next = sg; | |
5794 | last = sg; | |
5795 | last->next = first; | |
5796 | } | |
5797 | sd->groups = groups; | |
5798 | ||
5799 | return 0; | |
5800 | ||
5801 | fail: | |
5802 | free_sched_groups(first, 0); | |
5803 | ||
5804 | return -ENOMEM; | |
5805 | } | |
5806 | ||
dce840a0 | 5807 | static int get_group(int cpu, struct sd_data *sdd, struct sched_group **sg) |
1da177e4 | 5808 | { |
dce840a0 PZ |
5809 | struct sched_domain *sd = *per_cpu_ptr(sdd->sd, cpu); |
5810 | struct sched_domain *child = sd->child; | |
1da177e4 | 5811 | |
dce840a0 PZ |
5812 | if (child) |
5813 | cpu = cpumask_first(sched_domain_span(child)); | |
1e9f28fa | 5814 | |
9c3f75cb | 5815 | if (sg) { |
dce840a0 | 5816 | *sg = *per_cpu_ptr(sdd->sg, cpu); |
63b2ca30 NP |
5817 | (*sg)->sgc = *per_cpu_ptr(sdd->sgc, cpu); |
5818 | atomic_set(&(*sg)->sgc->ref, 1); /* for claim_allocations */ | |
9c3f75cb | 5819 | } |
dce840a0 PZ |
5820 | |
5821 | return cpu; | |
1e9f28fa | 5822 | } |
1e9f28fa | 5823 | |
01a08546 | 5824 | /* |
dce840a0 PZ |
5825 | * build_sched_groups will build a circular linked list of the groups |
5826 | * covered by the given span, and will set each group's ->cpumask correctly, | |
ced549fa | 5827 | * and ->cpu_capacity to 0. |
e3589f6c PZ |
5828 | * |
5829 | * Assumes the sched_domain tree is fully constructed | |
01a08546 | 5830 | */ |
e3589f6c PZ |
5831 | static int |
5832 | build_sched_groups(struct sched_domain *sd, int cpu) | |
1da177e4 | 5833 | { |
dce840a0 PZ |
5834 | struct sched_group *first = NULL, *last = NULL; |
5835 | struct sd_data *sdd = sd->private; | |
5836 | const struct cpumask *span = sched_domain_span(sd); | |
f96225fd | 5837 | struct cpumask *covered; |
dce840a0 | 5838 | int i; |
9c1cfda2 | 5839 | |
e3589f6c PZ |
5840 | get_group(cpu, sdd, &sd->groups); |
5841 | atomic_inc(&sd->groups->ref); | |
5842 | ||
0936629f | 5843 | if (cpu != cpumask_first(span)) |
e3589f6c PZ |
5844 | return 0; |
5845 | ||
f96225fd PZ |
5846 | lockdep_assert_held(&sched_domains_mutex); |
5847 | covered = sched_domains_tmpmask; | |
5848 | ||
dce840a0 | 5849 | cpumask_clear(covered); |
6711cab4 | 5850 | |
dce840a0 PZ |
5851 | for_each_cpu(i, span) { |
5852 | struct sched_group *sg; | |
cd08e923 | 5853 | int group, j; |
6711cab4 | 5854 | |
dce840a0 PZ |
5855 | if (cpumask_test_cpu(i, covered)) |
5856 | continue; | |
6711cab4 | 5857 | |
cd08e923 | 5858 | group = get_group(i, sdd, &sg); |
c1174876 | 5859 | cpumask_setall(sched_group_mask(sg)); |
0601a88d | 5860 | |
dce840a0 PZ |
5861 | for_each_cpu(j, span) { |
5862 | if (get_group(j, sdd, NULL) != group) | |
5863 | continue; | |
0601a88d | 5864 | |
dce840a0 PZ |
5865 | cpumask_set_cpu(j, covered); |
5866 | cpumask_set_cpu(j, sched_group_cpus(sg)); | |
5867 | } | |
0601a88d | 5868 | |
dce840a0 PZ |
5869 | if (!first) |
5870 | first = sg; | |
5871 | if (last) | |
5872 | last->next = sg; | |
5873 | last = sg; | |
5874 | } | |
5875 | last->next = first; | |
e3589f6c PZ |
5876 | |
5877 | return 0; | |
0601a88d | 5878 | } |
51888ca2 | 5879 | |
89c4710e | 5880 | /* |
63b2ca30 | 5881 | * Initialize sched groups cpu_capacity. |
89c4710e | 5882 | * |
63b2ca30 | 5883 | * cpu_capacity indicates the capacity of sched group, which is used while |
89c4710e | 5884 | * distributing the load between different sched groups in a sched domain. |
63b2ca30 NP |
5885 | * Typically cpu_capacity for all the groups in a sched domain will be same |
5886 | * unless there are asymmetries in the topology. If there are asymmetries, | |
5887 | * group having more cpu_capacity will pickup more load compared to the | |
5888 | * group having less cpu_capacity. | |
89c4710e | 5889 | */ |
63b2ca30 | 5890 | static void init_sched_groups_capacity(int cpu, struct sched_domain *sd) |
89c4710e | 5891 | { |
e3589f6c | 5892 | struct sched_group *sg = sd->groups; |
89c4710e | 5893 | |
94c95ba6 | 5894 | WARN_ON(!sg); |
e3589f6c PZ |
5895 | |
5896 | do { | |
5897 | sg->group_weight = cpumask_weight(sched_group_cpus(sg)); | |
5898 | sg = sg->next; | |
5899 | } while (sg != sd->groups); | |
89c4710e | 5900 | |
c1174876 | 5901 | if (cpu != group_balance_cpu(sg)) |
e3589f6c | 5902 | return; |
aae6d3dd | 5903 | |
63b2ca30 NP |
5904 | update_group_capacity(sd, cpu); |
5905 | atomic_set(&sg->sgc->nr_busy_cpus, sg->group_weight); | |
89c4710e SS |
5906 | } |
5907 | ||
7c16ec58 MT |
5908 | /* |
5909 | * Initializers for schedule domains | |
5910 | * Non-inlined to reduce accumulated stack pressure in build_sched_domains() | |
5911 | */ | |
5912 | ||
1d3504fc | 5913 | static int default_relax_domain_level = -1; |
60495e77 | 5914 | int sched_domain_level_max; |
1d3504fc HS |
5915 | |
5916 | static int __init setup_relax_domain_level(char *str) | |
5917 | { | |
a841f8ce DS |
5918 | if (kstrtoint(str, 0, &default_relax_domain_level)) |
5919 | pr_warn("Unable to set relax_domain_level\n"); | |
30e0e178 | 5920 | |
1d3504fc HS |
5921 | return 1; |
5922 | } | |
5923 | __setup("relax_domain_level=", setup_relax_domain_level); | |
5924 | ||
5925 | static void set_domain_attribute(struct sched_domain *sd, | |
5926 | struct sched_domain_attr *attr) | |
5927 | { | |
5928 | int request; | |
5929 | ||
5930 | if (!attr || attr->relax_domain_level < 0) { | |
5931 | if (default_relax_domain_level < 0) | |
5932 | return; | |
5933 | else | |
5934 | request = default_relax_domain_level; | |
5935 | } else | |
5936 | request = attr->relax_domain_level; | |
5937 | if (request < sd->level) { | |
5938 | /* turn off idle balance on this domain */ | |
c88d5910 | 5939 | sd->flags &= ~(SD_BALANCE_WAKE|SD_BALANCE_NEWIDLE); |
1d3504fc HS |
5940 | } else { |
5941 | /* turn on idle balance on this domain */ | |
c88d5910 | 5942 | sd->flags |= (SD_BALANCE_WAKE|SD_BALANCE_NEWIDLE); |
1d3504fc HS |
5943 | } |
5944 | } | |
5945 | ||
54ab4ff4 PZ |
5946 | static void __sdt_free(const struct cpumask *cpu_map); |
5947 | static int __sdt_alloc(const struct cpumask *cpu_map); | |
5948 | ||
2109b99e AH |
5949 | static void __free_domain_allocs(struct s_data *d, enum s_alloc what, |
5950 | const struct cpumask *cpu_map) | |
5951 | { | |
5952 | switch (what) { | |
2109b99e | 5953 | case sa_rootdomain: |
822ff793 PZ |
5954 | if (!atomic_read(&d->rd->refcount)) |
5955 | free_rootdomain(&d->rd->rcu); /* fall through */ | |
21d42ccf PZ |
5956 | case sa_sd: |
5957 | free_percpu(d->sd); /* fall through */ | |
dce840a0 | 5958 | case sa_sd_storage: |
54ab4ff4 | 5959 | __sdt_free(cpu_map); /* fall through */ |
2109b99e AH |
5960 | case sa_none: |
5961 | break; | |
5962 | } | |
5963 | } | |
3404c8d9 | 5964 | |
2109b99e AH |
5965 | static enum s_alloc __visit_domain_allocation_hell(struct s_data *d, |
5966 | const struct cpumask *cpu_map) | |
5967 | { | |
dce840a0 PZ |
5968 | memset(d, 0, sizeof(*d)); |
5969 | ||
54ab4ff4 PZ |
5970 | if (__sdt_alloc(cpu_map)) |
5971 | return sa_sd_storage; | |
dce840a0 PZ |
5972 | d->sd = alloc_percpu(struct sched_domain *); |
5973 | if (!d->sd) | |
5974 | return sa_sd_storage; | |
2109b99e | 5975 | d->rd = alloc_rootdomain(); |
dce840a0 | 5976 | if (!d->rd) |
21d42ccf | 5977 | return sa_sd; |
2109b99e AH |
5978 | return sa_rootdomain; |
5979 | } | |
57d885fe | 5980 | |
dce840a0 PZ |
5981 | /* |
5982 | * NULL the sd_data elements we've used to build the sched_domain and | |
5983 | * sched_group structure so that the subsequent __free_domain_allocs() | |
5984 | * will not free the data we're using. | |
5985 | */ | |
5986 | static void claim_allocations(int cpu, struct sched_domain *sd) | |
5987 | { | |
5988 | struct sd_data *sdd = sd->private; | |
dce840a0 PZ |
5989 | |
5990 | WARN_ON_ONCE(*per_cpu_ptr(sdd->sd, cpu) != sd); | |
5991 | *per_cpu_ptr(sdd->sd, cpu) = NULL; | |
5992 | ||
e3589f6c | 5993 | if (atomic_read(&(*per_cpu_ptr(sdd->sg, cpu))->ref)) |
dce840a0 | 5994 | *per_cpu_ptr(sdd->sg, cpu) = NULL; |
e3589f6c | 5995 | |
63b2ca30 NP |
5996 | if (atomic_read(&(*per_cpu_ptr(sdd->sgc, cpu))->ref)) |
5997 | *per_cpu_ptr(sdd->sgc, cpu) = NULL; | |
dce840a0 PZ |
5998 | } |
5999 | ||
cb83b629 | 6000 | #ifdef CONFIG_NUMA |
cb83b629 | 6001 | static int sched_domains_numa_levels; |
cb83b629 PZ |
6002 | static int *sched_domains_numa_distance; |
6003 | static struct cpumask ***sched_domains_numa_masks; | |
6004 | static int sched_domains_curr_level; | |
143e1e28 | 6005 | #endif |
cb83b629 | 6006 | |
143e1e28 VG |
6007 | /* |
6008 | * SD_flags allowed in topology descriptions. | |
6009 | * | |
5d4dfddd | 6010 | * SD_SHARE_CPUCAPACITY - describes SMT topologies |
143e1e28 VG |
6011 | * SD_SHARE_PKG_RESOURCES - describes shared caches |
6012 | * SD_NUMA - describes NUMA topologies | |
d77b3ed5 | 6013 | * SD_SHARE_POWERDOMAIN - describes shared power domain |
143e1e28 VG |
6014 | * |
6015 | * Odd one out: | |
6016 | * SD_ASYM_PACKING - describes SMT quirks | |
6017 | */ | |
6018 | #define TOPOLOGY_SD_FLAGS \ | |
5d4dfddd | 6019 | (SD_SHARE_CPUCAPACITY | \ |
143e1e28 VG |
6020 | SD_SHARE_PKG_RESOURCES | \ |
6021 | SD_NUMA | \ | |
d77b3ed5 VG |
6022 | SD_ASYM_PACKING | \ |
6023 | SD_SHARE_POWERDOMAIN) | |
cb83b629 PZ |
6024 | |
6025 | static struct sched_domain * | |
143e1e28 | 6026 | sd_init(struct sched_domain_topology_level *tl, int cpu) |
cb83b629 PZ |
6027 | { |
6028 | struct sched_domain *sd = *per_cpu_ptr(tl->data.sd, cpu); | |
143e1e28 VG |
6029 | int sd_weight, sd_flags = 0; |
6030 | ||
6031 | #ifdef CONFIG_NUMA | |
6032 | /* | |
6033 | * Ugly hack to pass state to sd_numa_mask()... | |
6034 | */ | |
6035 | sched_domains_curr_level = tl->numa_level; | |
6036 | #endif | |
6037 | ||
6038 | sd_weight = cpumask_weight(tl->mask(cpu)); | |
6039 | ||
6040 | if (tl->sd_flags) | |
6041 | sd_flags = (*tl->sd_flags)(); | |
6042 | if (WARN_ONCE(sd_flags & ~TOPOLOGY_SD_FLAGS, | |
6043 | "wrong sd_flags in topology description\n")) | |
6044 | sd_flags &= ~TOPOLOGY_SD_FLAGS; | |
cb83b629 PZ |
6045 | |
6046 | *sd = (struct sched_domain){ | |
6047 | .min_interval = sd_weight, | |
6048 | .max_interval = 2*sd_weight, | |
6049 | .busy_factor = 32, | |
870a0bb5 | 6050 | .imbalance_pct = 125, |
143e1e28 VG |
6051 | |
6052 | .cache_nice_tries = 0, | |
6053 | .busy_idx = 0, | |
6054 | .idle_idx = 0, | |
cb83b629 PZ |
6055 | .newidle_idx = 0, |
6056 | .wake_idx = 0, | |
6057 | .forkexec_idx = 0, | |
6058 | ||
6059 | .flags = 1*SD_LOAD_BALANCE | |
6060 | | 1*SD_BALANCE_NEWIDLE | |
143e1e28 VG |
6061 | | 1*SD_BALANCE_EXEC |
6062 | | 1*SD_BALANCE_FORK | |
cb83b629 | 6063 | | 0*SD_BALANCE_WAKE |
143e1e28 | 6064 | | 1*SD_WAKE_AFFINE |
5d4dfddd | 6065 | | 0*SD_SHARE_CPUCAPACITY |
cb83b629 | 6066 | | 0*SD_SHARE_PKG_RESOURCES |
143e1e28 | 6067 | | 0*SD_SERIALIZE |
cb83b629 | 6068 | | 0*SD_PREFER_SIBLING |
143e1e28 VG |
6069 | | 0*SD_NUMA |
6070 | | sd_flags | |
cb83b629 | 6071 | , |
143e1e28 | 6072 | |
cb83b629 PZ |
6073 | .last_balance = jiffies, |
6074 | .balance_interval = sd_weight, | |
143e1e28 | 6075 | .smt_gain = 0, |
2b4cfe64 JL |
6076 | .max_newidle_lb_cost = 0, |
6077 | .next_decay_max_lb_cost = jiffies, | |
143e1e28 VG |
6078 | #ifdef CONFIG_SCHED_DEBUG |
6079 | .name = tl->name, | |
6080 | #endif | |
cb83b629 | 6081 | }; |
cb83b629 PZ |
6082 | |
6083 | /* | |
143e1e28 | 6084 | * Convert topological properties into behaviour. |
cb83b629 | 6085 | */ |
143e1e28 | 6086 | |
5d4dfddd | 6087 | if (sd->flags & SD_SHARE_CPUCAPACITY) { |
143e1e28 VG |
6088 | sd->imbalance_pct = 110; |
6089 | sd->smt_gain = 1178; /* ~15% */ | |
143e1e28 VG |
6090 | |
6091 | } else if (sd->flags & SD_SHARE_PKG_RESOURCES) { | |
6092 | sd->imbalance_pct = 117; | |
6093 | sd->cache_nice_tries = 1; | |
6094 | sd->busy_idx = 2; | |
6095 | ||
6096 | #ifdef CONFIG_NUMA | |
6097 | } else if (sd->flags & SD_NUMA) { | |
6098 | sd->cache_nice_tries = 2; | |
6099 | sd->busy_idx = 3; | |
6100 | sd->idle_idx = 2; | |
6101 | ||
6102 | sd->flags |= SD_SERIALIZE; | |
6103 | if (sched_domains_numa_distance[tl->numa_level] > RECLAIM_DISTANCE) { | |
6104 | sd->flags &= ~(SD_BALANCE_EXEC | | |
6105 | SD_BALANCE_FORK | | |
6106 | SD_WAKE_AFFINE); | |
6107 | } | |
6108 | ||
6109 | #endif | |
6110 | } else { | |
6111 | sd->flags |= SD_PREFER_SIBLING; | |
6112 | sd->cache_nice_tries = 1; | |
6113 | sd->busy_idx = 2; | |
6114 | sd->idle_idx = 1; | |
6115 | } | |
6116 | ||
6117 | sd->private = &tl->data; | |
cb83b629 PZ |
6118 | |
6119 | return sd; | |
6120 | } | |
6121 | ||
143e1e28 VG |
6122 | /* |
6123 | * Topology list, bottom-up. | |
6124 | */ | |
6125 | static struct sched_domain_topology_level default_topology[] = { | |
6126 | #ifdef CONFIG_SCHED_SMT | |
6127 | { cpu_smt_mask, cpu_smt_flags, SD_INIT_NAME(SMT) }, | |
6128 | #endif | |
6129 | #ifdef CONFIG_SCHED_MC | |
6130 | { cpu_coregroup_mask, cpu_core_flags, SD_INIT_NAME(MC) }, | |
143e1e28 VG |
6131 | #endif |
6132 | { cpu_cpu_mask, SD_INIT_NAME(DIE) }, | |
6133 | { NULL, }, | |
6134 | }; | |
6135 | ||
6136 | struct sched_domain_topology_level *sched_domain_topology = default_topology; | |
6137 | ||
6138 | #define for_each_sd_topology(tl) \ | |
6139 | for (tl = sched_domain_topology; tl->mask; tl++) | |
6140 | ||
6141 | void set_sched_topology(struct sched_domain_topology_level *tl) | |
6142 | { | |
6143 | sched_domain_topology = tl; | |
6144 | } | |
6145 | ||
6146 | #ifdef CONFIG_NUMA | |
6147 | ||
cb83b629 PZ |
6148 | static const struct cpumask *sd_numa_mask(int cpu) |
6149 | { | |
6150 | return sched_domains_numa_masks[sched_domains_curr_level][cpu_to_node(cpu)]; | |
6151 | } | |
6152 | ||
d039ac60 PZ |
6153 | static void sched_numa_warn(const char *str) |
6154 | { | |
6155 | static int done = false; | |
6156 | int i,j; | |
6157 | ||
6158 | if (done) | |
6159 | return; | |
6160 | ||
6161 | done = true; | |
6162 | ||
6163 | printk(KERN_WARNING "ERROR: %s\n\n", str); | |
6164 | ||
6165 | for (i = 0; i < nr_node_ids; i++) { | |
6166 | printk(KERN_WARNING " "); | |
6167 | for (j = 0; j < nr_node_ids; j++) | |
6168 | printk(KERN_CONT "%02d ", node_distance(i,j)); | |
6169 | printk(KERN_CONT "\n"); | |
6170 | } | |
6171 | printk(KERN_WARNING "\n"); | |
6172 | } | |
6173 | ||
6174 | static bool find_numa_distance(int distance) | |
6175 | { | |
6176 | int i; | |
6177 | ||
6178 | if (distance == node_distance(0, 0)) | |
6179 | return true; | |
6180 | ||
6181 | for (i = 0; i < sched_domains_numa_levels; i++) { | |
6182 | if (sched_domains_numa_distance[i] == distance) | |
6183 | return true; | |
6184 | } | |
6185 | ||
6186 | return false; | |
6187 | } | |
6188 | ||
cb83b629 PZ |
6189 | static void sched_init_numa(void) |
6190 | { | |
6191 | int next_distance, curr_distance = node_distance(0, 0); | |
6192 | struct sched_domain_topology_level *tl; | |
6193 | int level = 0; | |
6194 | int i, j, k; | |
6195 | ||
cb83b629 PZ |
6196 | sched_domains_numa_distance = kzalloc(sizeof(int) * nr_node_ids, GFP_KERNEL); |
6197 | if (!sched_domains_numa_distance) | |
6198 | return; | |
6199 | ||
6200 | /* | |
6201 | * O(nr_nodes^2) deduplicating selection sort -- in order to find the | |
6202 | * unique distances in the node_distance() table. | |
6203 | * | |
6204 | * Assumes node_distance(0,j) includes all distances in | |
6205 | * node_distance(i,j) in order to avoid cubic time. | |
cb83b629 PZ |
6206 | */ |
6207 | next_distance = curr_distance; | |
6208 | for (i = 0; i < nr_node_ids; i++) { | |
6209 | for (j = 0; j < nr_node_ids; j++) { | |
d039ac60 PZ |
6210 | for (k = 0; k < nr_node_ids; k++) { |
6211 | int distance = node_distance(i, k); | |
6212 | ||
6213 | if (distance > curr_distance && | |
6214 | (distance < next_distance || | |
6215 | next_distance == curr_distance)) | |
6216 | next_distance = distance; | |
6217 | ||
6218 | /* | |
6219 | * While not a strong assumption it would be nice to know | |
6220 | * about cases where if node A is connected to B, B is not | |
6221 | * equally connected to A. | |
6222 | */ | |
6223 | if (sched_debug() && node_distance(k, i) != distance) | |
6224 | sched_numa_warn("Node-distance not symmetric"); | |
6225 | ||
6226 | if (sched_debug() && i && !find_numa_distance(distance)) | |
6227 | sched_numa_warn("Node-0 not representative"); | |
6228 | } | |
6229 | if (next_distance != curr_distance) { | |
6230 | sched_domains_numa_distance[level++] = next_distance; | |
6231 | sched_domains_numa_levels = level; | |
6232 | curr_distance = next_distance; | |
6233 | } else break; | |
cb83b629 | 6234 | } |
d039ac60 PZ |
6235 | |
6236 | /* | |
6237 | * In case of sched_debug() we verify the above assumption. | |
6238 | */ | |
6239 | if (!sched_debug()) | |
6240 | break; | |
cb83b629 PZ |
6241 | } |
6242 | /* | |
6243 | * 'level' contains the number of unique distances, excluding the | |
6244 | * identity distance node_distance(i,i). | |
6245 | * | |
28b4a521 | 6246 | * The sched_domains_numa_distance[] array includes the actual distance |
cb83b629 PZ |
6247 | * numbers. |
6248 | */ | |
6249 | ||
5f7865f3 TC |
6250 | /* |
6251 | * Here, we should temporarily reset sched_domains_numa_levels to 0. | |
6252 | * If it fails to allocate memory for array sched_domains_numa_masks[][], | |
6253 | * the array will contain less then 'level' members. This could be | |
6254 | * dangerous when we use it to iterate array sched_domains_numa_masks[][] | |
6255 | * in other functions. | |
6256 | * | |
6257 | * We reset it to 'level' at the end of this function. | |
6258 | */ | |
6259 | sched_domains_numa_levels = 0; | |
6260 | ||
cb83b629 PZ |
6261 | sched_domains_numa_masks = kzalloc(sizeof(void *) * level, GFP_KERNEL); |
6262 | if (!sched_domains_numa_masks) | |
6263 | return; | |
6264 | ||
6265 | /* | |
6266 | * Now for each level, construct a mask per node which contains all | |
6267 | * cpus of nodes that are that many hops away from us. | |
6268 | */ | |
6269 | for (i = 0; i < level; i++) { | |
6270 | sched_domains_numa_masks[i] = | |
6271 | kzalloc(nr_node_ids * sizeof(void *), GFP_KERNEL); | |
6272 | if (!sched_domains_numa_masks[i]) | |
6273 | return; | |
6274 | ||
6275 | for (j = 0; j < nr_node_ids; j++) { | |
2ea45800 | 6276 | struct cpumask *mask = kzalloc(cpumask_size(), GFP_KERNEL); |
cb83b629 PZ |
6277 | if (!mask) |
6278 | return; | |
6279 | ||
6280 | sched_domains_numa_masks[i][j] = mask; | |
6281 | ||
6282 | for (k = 0; k < nr_node_ids; k++) { | |
dd7d8634 | 6283 | if (node_distance(j, k) > sched_domains_numa_distance[i]) |
cb83b629 PZ |
6284 | continue; |
6285 | ||
6286 | cpumask_or(mask, mask, cpumask_of_node(k)); | |
6287 | } | |
6288 | } | |
6289 | } | |
6290 | ||
143e1e28 VG |
6291 | /* Compute default topology size */ |
6292 | for (i = 0; sched_domain_topology[i].mask; i++); | |
6293 | ||
c515db8c | 6294 | tl = kzalloc((i + level + 1) * |
cb83b629 PZ |
6295 | sizeof(struct sched_domain_topology_level), GFP_KERNEL); |
6296 | if (!tl) | |
6297 | return; | |
6298 | ||
6299 | /* | |
6300 | * Copy the default topology bits.. | |
6301 | */ | |
143e1e28 VG |
6302 | for (i = 0; sched_domain_topology[i].mask; i++) |
6303 | tl[i] = sched_domain_topology[i]; | |
cb83b629 PZ |
6304 | |
6305 | /* | |
6306 | * .. and append 'j' levels of NUMA goodness. | |
6307 | */ | |
6308 | for (j = 0; j < level; i++, j++) { | |
6309 | tl[i] = (struct sched_domain_topology_level){ | |
cb83b629 | 6310 | .mask = sd_numa_mask, |
143e1e28 | 6311 | .sd_flags = cpu_numa_flags, |
cb83b629 PZ |
6312 | .flags = SDTL_OVERLAP, |
6313 | .numa_level = j, | |
143e1e28 | 6314 | SD_INIT_NAME(NUMA) |
cb83b629 PZ |
6315 | }; |
6316 | } | |
6317 | ||
6318 | sched_domain_topology = tl; | |
5f7865f3 TC |
6319 | |
6320 | sched_domains_numa_levels = level; | |
cb83b629 | 6321 | } |
301a5cba TC |
6322 | |
6323 | static void sched_domains_numa_masks_set(int cpu) | |
6324 | { | |
6325 | int i, j; | |
6326 | int node = cpu_to_node(cpu); | |
6327 | ||
6328 | for (i = 0; i < sched_domains_numa_levels; i++) { | |
6329 | for (j = 0; j < nr_node_ids; j++) { | |
6330 | if (node_distance(j, node) <= sched_domains_numa_distance[i]) | |
6331 | cpumask_set_cpu(cpu, sched_domains_numa_masks[i][j]); | |
6332 | } | |
6333 | } | |
6334 | } | |
6335 | ||
6336 | static void sched_domains_numa_masks_clear(int cpu) | |
6337 | { | |
6338 | int i, j; | |
6339 | for (i = 0; i < sched_domains_numa_levels; i++) { | |
6340 | for (j = 0; j < nr_node_ids; j++) | |
6341 | cpumask_clear_cpu(cpu, sched_domains_numa_masks[i][j]); | |
6342 | } | |
6343 | } | |
6344 | ||
6345 | /* | |
6346 | * Update sched_domains_numa_masks[level][node] array when new cpus | |
6347 | * are onlined. | |
6348 | */ | |
6349 | static int sched_domains_numa_masks_update(struct notifier_block *nfb, | |
6350 | unsigned long action, | |
6351 | void *hcpu) | |
6352 | { | |
6353 | int cpu = (long)hcpu; | |
6354 | ||
6355 | switch (action & ~CPU_TASKS_FROZEN) { | |
6356 | case CPU_ONLINE: | |
6357 | sched_domains_numa_masks_set(cpu); | |
6358 | break; | |
6359 | ||
6360 | case CPU_DEAD: | |
6361 | sched_domains_numa_masks_clear(cpu); | |
6362 | break; | |
6363 | ||
6364 | default: | |
6365 | return NOTIFY_DONE; | |
6366 | } | |
6367 | ||
6368 | return NOTIFY_OK; | |
cb83b629 PZ |
6369 | } |
6370 | #else | |
6371 | static inline void sched_init_numa(void) | |
6372 | { | |
6373 | } | |
301a5cba TC |
6374 | |
6375 | static int sched_domains_numa_masks_update(struct notifier_block *nfb, | |
6376 | unsigned long action, | |
6377 | void *hcpu) | |
6378 | { | |
6379 | return 0; | |
6380 | } | |
cb83b629 PZ |
6381 | #endif /* CONFIG_NUMA */ |
6382 | ||
54ab4ff4 PZ |
6383 | static int __sdt_alloc(const struct cpumask *cpu_map) |
6384 | { | |
6385 | struct sched_domain_topology_level *tl; | |
6386 | int j; | |
6387 | ||
27723a68 | 6388 | for_each_sd_topology(tl) { |
54ab4ff4 PZ |
6389 | struct sd_data *sdd = &tl->data; |
6390 | ||
6391 | sdd->sd = alloc_percpu(struct sched_domain *); | |
6392 | if (!sdd->sd) | |
6393 | return -ENOMEM; | |
6394 | ||
6395 | sdd->sg = alloc_percpu(struct sched_group *); | |
6396 | if (!sdd->sg) | |
6397 | return -ENOMEM; | |
6398 | ||
63b2ca30 NP |
6399 | sdd->sgc = alloc_percpu(struct sched_group_capacity *); |
6400 | if (!sdd->sgc) | |
9c3f75cb PZ |
6401 | return -ENOMEM; |
6402 | ||
54ab4ff4 PZ |
6403 | for_each_cpu(j, cpu_map) { |
6404 | struct sched_domain *sd; | |
6405 | struct sched_group *sg; | |
63b2ca30 | 6406 | struct sched_group_capacity *sgc; |
54ab4ff4 PZ |
6407 | |
6408 | sd = kzalloc_node(sizeof(struct sched_domain) + cpumask_size(), | |
6409 | GFP_KERNEL, cpu_to_node(j)); | |
6410 | if (!sd) | |
6411 | return -ENOMEM; | |
6412 | ||
6413 | *per_cpu_ptr(sdd->sd, j) = sd; | |
6414 | ||
6415 | sg = kzalloc_node(sizeof(struct sched_group) + cpumask_size(), | |
6416 | GFP_KERNEL, cpu_to_node(j)); | |
6417 | if (!sg) | |
6418 | return -ENOMEM; | |
6419 | ||
30b4e9eb IM |
6420 | sg->next = sg; |
6421 | ||
54ab4ff4 | 6422 | *per_cpu_ptr(sdd->sg, j) = sg; |
9c3f75cb | 6423 | |
63b2ca30 | 6424 | sgc = kzalloc_node(sizeof(struct sched_group_capacity) + cpumask_size(), |
9c3f75cb | 6425 | GFP_KERNEL, cpu_to_node(j)); |
63b2ca30 | 6426 | if (!sgc) |
9c3f75cb PZ |
6427 | return -ENOMEM; |
6428 | ||
63b2ca30 | 6429 | *per_cpu_ptr(sdd->sgc, j) = sgc; |
54ab4ff4 PZ |
6430 | } |
6431 | } | |
6432 | ||
6433 | return 0; | |
6434 | } | |
6435 | ||
6436 | static void __sdt_free(const struct cpumask *cpu_map) | |
6437 | { | |
6438 | struct sched_domain_topology_level *tl; | |
6439 | int j; | |
6440 | ||
27723a68 | 6441 | for_each_sd_topology(tl) { |
54ab4ff4 PZ |
6442 | struct sd_data *sdd = &tl->data; |
6443 | ||
6444 | for_each_cpu(j, cpu_map) { | |
fb2cf2c6 | 6445 | struct sched_domain *sd; |
6446 | ||
6447 | if (sdd->sd) { | |
6448 | sd = *per_cpu_ptr(sdd->sd, j); | |
6449 | if (sd && (sd->flags & SD_OVERLAP)) | |
6450 | free_sched_groups(sd->groups, 0); | |
6451 | kfree(*per_cpu_ptr(sdd->sd, j)); | |
6452 | } | |
6453 | ||
6454 | if (sdd->sg) | |
6455 | kfree(*per_cpu_ptr(sdd->sg, j)); | |
63b2ca30 NP |
6456 | if (sdd->sgc) |
6457 | kfree(*per_cpu_ptr(sdd->sgc, j)); | |
54ab4ff4 PZ |
6458 | } |
6459 | free_percpu(sdd->sd); | |
fb2cf2c6 | 6460 | sdd->sd = NULL; |
54ab4ff4 | 6461 | free_percpu(sdd->sg); |
fb2cf2c6 | 6462 | sdd->sg = NULL; |
63b2ca30 NP |
6463 | free_percpu(sdd->sgc); |
6464 | sdd->sgc = NULL; | |
54ab4ff4 PZ |
6465 | } |
6466 | } | |
6467 | ||
2c402dc3 | 6468 | struct sched_domain *build_sched_domain(struct sched_domain_topology_level *tl, |
4a850cbe VK |
6469 | const struct cpumask *cpu_map, struct sched_domain_attr *attr, |
6470 | struct sched_domain *child, int cpu) | |
2c402dc3 | 6471 | { |
143e1e28 | 6472 | struct sched_domain *sd = sd_init(tl, cpu); |
2c402dc3 | 6473 | if (!sd) |
d069b916 | 6474 | return child; |
2c402dc3 | 6475 | |
2c402dc3 | 6476 | cpumask_and(sched_domain_span(sd), cpu_map, tl->mask(cpu)); |
60495e77 PZ |
6477 | if (child) { |
6478 | sd->level = child->level + 1; | |
6479 | sched_domain_level_max = max(sched_domain_level_max, sd->level); | |
d069b916 | 6480 | child->parent = sd; |
c75e0128 | 6481 | sd->child = child; |
60495e77 | 6482 | } |
a841f8ce | 6483 | set_domain_attribute(sd, attr); |
2c402dc3 PZ |
6484 | |
6485 | return sd; | |
6486 | } | |
6487 | ||
2109b99e AH |
6488 | /* |
6489 | * Build sched domains for a given set of cpus and attach the sched domains | |
6490 | * to the individual cpus | |
6491 | */ | |
dce840a0 PZ |
6492 | static int build_sched_domains(const struct cpumask *cpu_map, |
6493 | struct sched_domain_attr *attr) | |
2109b99e | 6494 | { |
1c632169 | 6495 | enum s_alloc alloc_state; |
dce840a0 | 6496 | struct sched_domain *sd; |
2109b99e | 6497 | struct s_data d; |
822ff793 | 6498 | int i, ret = -ENOMEM; |
9c1cfda2 | 6499 | |
2109b99e AH |
6500 | alloc_state = __visit_domain_allocation_hell(&d, cpu_map); |
6501 | if (alloc_state != sa_rootdomain) | |
6502 | goto error; | |
9c1cfda2 | 6503 | |
dce840a0 | 6504 | /* Set up domains for cpus specified by the cpu_map. */ |
abcd083a | 6505 | for_each_cpu(i, cpu_map) { |
eb7a74e6 PZ |
6506 | struct sched_domain_topology_level *tl; |
6507 | ||
3bd65a80 | 6508 | sd = NULL; |
27723a68 | 6509 | for_each_sd_topology(tl) { |
4a850cbe | 6510 | sd = build_sched_domain(tl, cpu_map, attr, sd, i); |
22da9569 VK |
6511 | if (tl == sched_domain_topology) |
6512 | *per_cpu_ptr(d.sd, i) = sd; | |
e3589f6c PZ |
6513 | if (tl->flags & SDTL_OVERLAP || sched_feat(FORCE_SD_OVERLAP)) |
6514 | sd->flags |= SD_OVERLAP; | |
d110235d PZ |
6515 | if (cpumask_equal(cpu_map, sched_domain_span(sd))) |
6516 | break; | |
e3589f6c | 6517 | } |
dce840a0 PZ |
6518 | } |
6519 | ||
6520 | /* Build the groups for the domains */ | |
6521 | for_each_cpu(i, cpu_map) { | |
6522 | for (sd = *per_cpu_ptr(d.sd, i); sd; sd = sd->parent) { | |
6523 | sd->span_weight = cpumask_weight(sched_domain_span(sd)); | |
e3589f6c PZ |
6524 | if (sd->flags & SD_OVERLAP) { |
6525 | if (build_overlap_sched_groups(sd, i)) | |
6526 | goto error; | |
6527 | } else { | |
6528 | if (build_sched_groups(sd, i)) | |
6529 | goto error; | |
6530 | } | |
1cf51902 | 6531 | } |
a06dadbe | 6532 | } |
9c1cfda2 | 6533 | |
ced549fa | 6534 | /* Calculate CPU capacity for physical packages and nodes */ |
a9c9a9b6 PZ |
6535 | for (i = nr_cpumask_bits-1; i >= 0; i--) { |
6536 | if (!cpumask_test_cpu(i, cpu_map)) | |
6537 | continue; | |
9c1cfda2 | 6538 | |
dce840a0 PZ |
6539 | for (sd = *per_cpu_ptr(d.sd, i); sd; sd = sd->parent) { |
6540 | claim_allocations(i, sd); | |
63b2ca30 | 6541 | init_sched_groups_capacity(i, sd); |
dce840a0 | 6542 | } |
f712c0c7 | 6543 | } |
9c1cfda2 | 6544 | |
1da177e4 | 6545 | /* Attach the domains */ |
dce840a0 | 6546 | rcu_read_lock(); |
abcd083a | 6547 | for_each_cpu(i, cpu_map) { |
21d42ccf | 6548 | sd = *per_cpu_ptr(d.sd, i); |
49a02c51 | 6549 | cpu_attach_domain(sd, d.rd, i); |
1da177e4 | 6550 | } |
dce840a0 | 6551 | rcu_read_unlock(); |
51888ca2 | 6552 | |
822ff793 | 6553 | ret = 0; |
51888ca2 | 6554 | error: |
2109b99e | 6555 | __free_domain_allocs(&d, alloc_state, cpu_map); |
822ff793 | 6556 | return ret; |
1da177e4 | 6557 | } |
029190c5 | 6558 | |
acc3f5d7 | 6559 | static cpumask_var_t *doms_cur; /* current sched domains */ |
029190c5 | 6560 | static int ndoms_cur; /* number of sched domains in 'doms_cur' */ |
4285f594 IM |
6561 | static struct sched_domain_attr *dattr_cur; |
6562 | /* attribues of custom domains in 'doms_cur' */ | |
029190c5 PJ |
6563 | |
6564 | /* | |
6565 | * Special case: If a kmalloc of a doms_cur partition (array of | |
4212823f RR |
6566 | * cpumask) fails, then fallback to a single sched domain, |
6567 | * as determined by the single cpumask fallback_doms. | |
029190c5 | 6568 | */ |
4212823f | 6569 | static cpumask_var_t fallback_doms; |
029190c5 | 6570 | |
ee79d1bd HC |
6571 | /* |
6572 | * arch_update_cpu_topology lets virtualized architectures update the | |
6573 | * cpu core maps. It is supposed to return 1 if the topology changed | |
6574 | * or 0 if it stayed the same. | |
6575 | */ | |
52f5684c | 6576 | int __weak arch_update_cpu_topology(void) |
22e52b07 | 6577 | { |
ee79d1bd | 6578 | return 0; |
22e52b07 HC |
6579 | } |
6580 | ||
acc3f5d7 RR |
6581 | cpumask_var_t *alloc_sched_domains(unsigned int ndoms) |
6582 | { | |
6583 | int i; | |
6584 | cpumask_var_t *doms; | |
6585 | ||
6586 | doms = kmalloc(sizeof(*doms) * ndoms, GFP_KERNEL); | |
6587 | if (!doms) | |
6588 | return NULL; | |
6589 | for (i = 0; i < ndoms; i++) { | |
6590 | if (!alloc_cpumask_var(&doms[i], GFP_KERNEL)) { | |
6591 | free_sched_domains(doms, i); | |
6592 | return NULL; | |
6593 | } | |
6594 | } | |
6595 | return doms; | |
6596 | } | |
6597 | ||
6598 | void free_sched_domains(cpumask_var_t doms[], unsigned int ndoms) | |
6599 | { | |
6600 | unsigned int i; | |
6601 | for (i = 0; i < ndoms; i++) | |
6602 | free_cpumask_var(doms[i]); | |
6603 | kfree(doms); | |
6604 | } | |
6605 | ||
1a20ff27 | 6606 | /* |
41a2d6cf | 6607 | * Set up scheduler domains and groups. Callers must hold the hotplug lock. |
029190c5 PJ |
6608 | * For now this just excludes isolated cpus, but could be used to |
6609 | * exclude other special cases in the future. | |
1a20ff27 | 6610 | */ |
c4a8849a | 6611 | static int init_sched_domains(const struct cpumask *cpu_map) |
1a20ff27 | 6612 | { |
7378547f MM |
6613 | int err; |
6614 | ||
22e52b07 | 6615 | arch_update_cpu_topology(); |
029190c5 | 6616 | ndoms_cur = 1; |
acc3f5d7 | 6617 | doms_cur = alloc_sched_domains(ndoms_cur); |
029190c5 | 6618 | if (!doms_cur) |
acc3f5d7 RR |
6619 | doms_cur = &fallback_doms; |
6620 | cpumask_andnot(doms_cur[0], cpu_map, cpu_isolated_map); | |
dce840a0 | 6621 | err = build_sched_domains(doms_cur[0], NULL); |
6382bc90 | 6622 | register_sched_domain_sysctl(); |
7378547f MM |
6623 | |
6624 | return err; | |
1a20ff27 DG |
6625 | } |
6626 | ||
1a20ff27 DG |
6627 | /* |
6628 | * Detach sched domains from a group of cpus specified in cpu_map | |
6629 | * These cpus will now be attached to the NULL domain | |
6630 | */ | |
96f874e2 | 6631 | static void detach_destroy_domains(const struct cpumask *cpu_map) |
1a20ff27 DG |
6632 | { |
6633 | int i; | |
6634 | ||
dce840a0 | 6635 | rcu_read_lock(); |
abcd083a | 6636 | for_each_cpu(i, cpu_map) |
57d885fe | 6637 | cpu_attach_domain(NULL, &def_root_domain, i); |
dce840a0 | 6638 | rcu_read_unlock(); |
1a20ff27 DG |
6639 | } |
6640 | ||
1d3504fc HS |
6641 | /* handle null as "default" */ |
6642 | static int dattrs_equal(struct sched_domain_attr *cur, int idx_cur, | |
6643 | struct sched_domain_attr *new, int idx_new) | |
6644 | { | |
6645 | struct sched_domain_attr tmp; | |
6646 | ||
6647 | /* fast path */ | |
6648 | if (!new && !cur) | |
6649 | return 1; | |
6650 | ||
6651 | tmp = SD_ATTR_INIT; | |
6652 | return !memcmp(cur ? (cur + idx_cur) : &tmp, | |
6653 | new ? (new + idx_new) : &tmp, | |
6654 | sizeof(struct sched_domain_attr)); | |
6655 | } | |
6656 | ||
029190c5 PJ |
6657 | /* |
6658 | * Partition sched domains as specified by the 'ndoms_new' | |
41a2d6cf | 6659 | * cpumasks in the array doms_new[] of cpumasks. This compares |
029190c5 PJ |
6660 | * doms_new[] to the current sched domain partitioning, doms_cur[]. |
6661 | * It destroys each deleted domain and builds each new domain. | |
6662 | * | |
acc3f5d7 | 6663 | * 'doms_new' is an array of cpumask_var_t's of length 'ndoms_new'. |
41a2d6cf IM |
6664 | * The masks don't intersect (don't overlap.) We should setup one |
6665 | * sched domain for each mask. CPUs not in any of the cpumasks will | |
6666 | * not be load balanced. If the same cpumask appears both in the | |
029190c5 PJ |
6667 | * current 'doms_cur' domains and in the new 'doms_new', we can leave |
6668 | * it as it is. | |
6669 | * | |
acc3f5d7 RR |
6670 | * The passed in 'doms_new' should be allocated using |
6671 | * alloc_sched_domains. This routine takes ownership of it and will | |
6672 | * free_sched_domains it when done with it. If the caller failed the | |
6673 | * alloc call, then it can pass in doms_new == NULL && ndoms_new == 1, | |
6674 | * and partition_sched_domains() will fallback to the single partition | |
6675 | * 'fallback_doms', it also forces the domains to be rebuilt. | |
029190c5 | 6676 | * |
96f874e2 | 6677 | * If doms_new == NULL it will be replaced with cpu_online_mask. |
700018e0 LZ |
6678 | * ndoms_new == 0 is a special case for destroying existing domains, |
6679 | * and it will not create the default domain. | |
dfb512ec | 6680 | * |
029190c5 PJ |
6681 | * Call with hotplug lock held |
6682 | */ | |
acc3f5d7 | 6683 | void partition_sched_domains(int ndoms_new, cpumask_var_t doms_new[], |
1d3504fc | 6684 | struct sched_domain_attr *dattr_new) |
029190c5 | 6685 | { |
dfb512ec | 6686 | int i, j, n; |
d65bd5ec | 6687 | int new_topology; |
029190c5 | 6688 | |
712555ee | 6689 | mutex_lock(&sched_domains_mutex); |
a1835615 | 6690 | |
7378547f MM |
6691 | /* always unregister in case we don't destroy any domains */ |
6692 | unregister_sched_domain_sysctl(); | |
6693 | ||
d65bd5ec HC |
6694 | /* Let architecture update cpu core mappings. */ |
6695 | new_topology = arch_update_cpu_topology(); | |
6696 | ||
dfb512ec | 6697 | n = doms_new ? ndoms_new : 0; |
029190c5 PJ |
6698 | |
6699 | /* Destroy deleted domains */ | |
6700 | for (i = 0; i < ndoms_cur; i++) { | |
d65bd5ec | 6701 | for (j = 0; j < n && !new_topology; j++) { |
acc3f5d7 | 6702 | if (cpumask_equal(doms_cur[i], doms_new[j]) |
1d3504fc | 6703 | && dattrs_equal(dattr_cur, i, dattr_new, j)) |
029190c5 PJ |
6704 | goto match1; |
6705 | } | |
6706 | /* no match - a current sched domain not in new doms_new[] */ | |
acc3f5d7 | 6707 | detach_destroy_domains(doms_cur[i]); |
029190c5 PJ |
6708 | match1: |
6709 | ; | |
6710 | } | |
6711 | ||
c8d2d47a | 6712 | n = ndoms_cur; |
e761b772 | 6713 | if (doms_new == NULL) { |
c8d2d47a | 6714 | n = 0; |
acc3f5d7 | 6715 | doms_new = &fallback_doms; |
6ad4c188 | 6716 | cpumask_andnot(doms_new[0], cpu_active_mask, cpu_isolated_map); |
faa2f98f | 6717 | WARN_ON_ONCE(dattr_new); |
e761b772 MK |
6718 | } |
6719 | ||
029190c5 PJ |
6720 | /* Build new domains */ |
6721 | for (i = 0; i < ndoms_new; i++) { | |
c8d2d47a | 6722 | for (j = 0; j < n && !new_topology; j++) { |
acc3f5d7 | 6723 | if (cpumask_equal(doms_new[i], doms_cur[j]) |
1d3504fc | 6724 | && dattrs_equal(dattr_new, i, dattr_cur, j)) |
029190c5 PJ |
6725 | goto match2; |
6726 | } | |
6727 | /* no match - add a new doms_new */ | |
dce840a0 | 6728 | build_sched_domains(doms_new[i], dattr_new ? dattr_new + i : NULL); |
029190c5 PJ |
6729 | match2: |
6730 | ; | |
6731 | } | |
6732 | ||
6733 | /* Remember the new sched domains */ | |
acc3f5d7 RR |
6734 | if (doms_cur != &fallback_doms) |
6735 | free_sched_domains(doms_cur, ndoms_cur); | |
1d3504fc | 6736 | kfree(dattr_cur); /* kfree(NULL) is safe */ |
029190c5 | 6737 | doms_cur = doms_new; |
1d3504fc | 6738 | dattr_cur = dattr_new; |
029190c5 | 6739 | ndoms_cur = ndoms_new; |
7378547f MM |
6740 | |
6741 | register_sched_domain_sysctl(); | |
a1835615 | 6742 | |
712555ee | 6743 | mutex_unlock(&sched_domains_mutex); |
029190c5 PJ |
6744 | } |
6745 | ||
d35be8ba SB |
6746 | static int num_cpus_frozen; /* used to mark begin/end of suspend/resume */ |
6747 | ||
1da177e4 | 6748 | /* |
3a101d05 TH |
6749 | * Update cpusets according to cpu_active mask. If cpusets are |
6750 | * disabled, cpuset_update_active_cpus() becomes a simple wrapper | |
6751 | * around partition_sched_domains(). | |
d35be8ba SB |
6752 | * |
6753 | * If we come here as part of a suspend/resume, don't touch cpusets because we | |
6754 | * want to restore it back to its original state upon resume anyway. | |
1da177e4 | 6755 | */ |
0b2e918a TH |
6756 | static int cpuset_cpu_active(struct notifier_block *nfb, unsigned long action, |
6757 | void *hcpu) | |
e761b772 | 6758 | { |
d35be8ba SB |
6759 | switch (action) { |
6760 | case CPU_ONLINE_FROZEN: | |
6761 | case CPU_DOWN_FAILED_FROZEN: | |
6762 | ||
6763 | /* | |
6764 | * num_cpus_frozen tracks how many CPUs are involved in suspend | |
6765 | * resume sequence. As long as this is not the last online | |
6766 | * operation in the resume sequence, just build a single sched | |
6767 | * domain, ignoring cpusets. | |
6768 | */ | |
6769 | num_cpus_frozen--; | |
6770 | if (likely(num_cpus_frozen)) { | |
6771 | partition_sched_domains(1, NULL, NULL); | |
6772 | break; | |
6773 | } | |
6774 | ||
6775 | /* | |
6776 | * This is the last CPU online operation. So fall through and | |
6777 | * restore the original sched domains by considering the | |
6778 | * cpuset configurations. | |
6779 | */ | |
6780 | ||
e761b772 | 6781 | case CPU_ONLINE: |
6ad4c188 | 6782 | case CPU_DOWN_FAILED: |
7ddf96b0 | 6783 | cpuset_update_active_cpus(true); |
d35be8ba | 6784 | break; |
3a101d05 TH |
6785 | default: |
6786 | return NOTIFY_DONE; | |
6787 | } | |
d35be8ba | 6788 | return NOTIFY_OK; |
3a101d05 | 6789 | } |
e761b772 | 6790 | |
0b2e918a TH |
6791 | static int cpuset_cpu_inactive(struct notifier_block *nfb, unsigned long action, |
6792 | void *hcpu) | |
3a101d05 | 6793 | { |
d35be8ba | 6794 | switch (action) { |
3a101d05 | 6795 | case CPU_DOWN_PREPARE: |
7ddf96b0 | 6796 | cpuset_update_active_cpus(false); |
d35be8ba SB |
6797 | break; |
6798 | case CPU_DOWN_PREPARE_FROZEN: | |
6799 | num_cpus_frozen++; | |
6800 | partition_sched_domains(1, NULL, NULL); | |
6801 | break; | |
e761b772 MK |
6802 | default: |
6803 | return NOTIFY_DONE; | |
6804 | } | |
d35be8ba | 6805 | return NOTIFY_OK; |
e761b772 | 6806 | } |
e761b772 | 6807 | |
1da177e4 LT |
6808 | void __init sched_init_smp(void) |
6809 | { | |
dcc30a35 RR |
6810 | cpumask_var_t non_isolated_cpus; |
6811 | ||
6812 | alloc_cpumask_var(&non_isolated_cpus, GFP_KERNEL); | |
cb5fd13f | 6813 | alloc_cpumask_var(&fallback_doms, GFP_KERNEL); |
5c1e1767 | 6814 | |
cb83b629 PZ |
6815 | sched_init_numa(); |
6816 | ||
6acce3ef PZ |
6817 | /* |
6818 | * There's no userspace yet to cause hotplug operations; hence all the | |
6819 | * cpu masks are stable and all blatant races in the below code cannot | |
6820 | * happen. | |
6821 | */ | |
712555ee | 6822 | mutex_lock(&sched_domains_mutex); |
c4a8849a | 6823 | init_sched_domains(cpu_active_mask); |
dcc30a35 RR |
6824 | cpumask_andnot(non_isolated_cpus, cpu_possible_mask, cpu_isolated_map); |
6825 | if (cpumask_empty(non_isolated_cpus)) | |
6826 | cpumask_set_cpu(smp_processor_id(), non_isolated_cpus); | |
712555ee | 6827 | mutex_unlock(&sched_domains_mutex); |
e761b772 | 6828 | |
301a5cba | 6829 | hotcpu_notifier(sched_domains_numa_masks_update, CPU_PRI_SCHED_ACTIVE); |
3a101d05 TH |
6830 | hotcpu_notifier(cpuset_cpu_active, CPU_PRI_CPUSET_ACTIVE); |
6831 | hotcpu_notifier(cpuset_cpu_inactive, CPU_PRI_CPUSET_INACTIVE); | |
e761b772 | 6832 | |
b328ca18 | 6833 | init_hrtick(); |
5c1e1767 NP |
6834 | |
6835 | /* Move init over to a non-isolated CPU */ | |
dcc30a35 | 6836 | if (set_cpus_allowed_ptr(current, non_isolated_cpus) < 0) |
5c1e1767 | 6837 | BUG(); |
19978ca6 | 6838 | sched_init_granularity(); |
dcc30a35 | 6839 | free_cpumask_var(non_isolated_cpus); |
4212823f | 6840 | |
0e3900e6 | 6841 | init_sched_rt_class(); |
1baca4ce | 6842 | init_sched_dl_class(); |
1da177e4 LT |
6843 | } |
6844 | #else | |
6845 | void __init sched_init_smp(void) | |
6846 | { | |
19978ca6 | 6847 | sched_init_granularity(); |
1da177e4 LT |
6848 | } |
6849 | #endif /* CONFIG_SMP */ | |
6850 | ||
cd1bb94b AB |
6851 | const_debug unsigned int sysctl_timer_migration = 1; |
6852 | ||
1da177e4 LT |
6853 | int in_sched_functions(unsigned long addr) |
6854 | { | |
1da177e4 LT |
6855 | return in_lock_functions(addr) || |
6856 | (addr >= (unsigned long)__sched_text_start | |
6857 | && addr < (unsigned long)__sched_text_end); | |
6858 | } | |
6859 | ||
029632fb | 6860 | #ifdef CONFIG_CGROUP_SCHED |
27b4b931 LZ |
6861 | /* |
6862 | * Default task group. | |
6863 | * Every task in system belongs to this group at bootup. | |
6864 | */ | |
029632fb | 6865 | struct task_group root_task_group; |
35cf4e50 | 6866 | LIST_HEAD(task_groups); |
052f1dc7 | 6867 | #endif |
6f505b16 | 6868 | |
e6252c3e | 6869 | DECLARE_PER_CPU(cpumask_var_t, load_balance_mask); |
6f505b16 | 6870 | |
1da177e4 LT |
6871 | void __init sched_init(void) |
6872 | { | |
dd41f596 | 6873 | int i, j; |
434d53b0 MT |
6874 | unsigned long alloc_size = 0, ptr; |
6875 | ||
6876 | #ifdef CONFIG_FAIR_GROUP_SCHED | |
6877 | alloc_size += 2 * nr_cpu_ids * sizeof(void **); | |
6878 | #endif | |
6879 | #ifdef CONFIG_RT_GROUP_SCHED | |
6880 | alloc_size += 2 * nr_cpu_ids * sizeof(void **); | |
eff766a6 | 6881 | #endif |
df7c8e84 | 6882 | #ifdef CONFIG_CPUMASK_OFFSTACK |
8c083f08 | 6883 | alloc_size += num_possible_cpus() * cpumask_size(); |
434d53b0 | 6884 | #endif |
434d53b0 | 6885 | if (alloc_size) { |
36b7b6d4 | 6886 | ptr = (unsigned long)kzalloc(alloc_size, GFP_NOWAIT); |
434d53b0 MT |
6887 | |
6888 | #ifdef CONFIG_FAIR_GROUP_SCHED | |
07e06b01 | 6889 | root_task_group.se = (struct sched_entity **)ptr; |
434d53b0 MT |
6890 | ptr += nr_cpu_ids * sizeof(void **); |
6891 | ||
07e06b01 | 6892 | root_task_group.cfs_rq = (struct cfs_rq **)ptr; |
434d53b0 | 6893 | ptr += nr_cpu_ids * sizeof(void **); |
eff766a6 | 6894 | |
6d6bc0ad | 6895 | #endif /* CONFIG_FAIR_GROUP_SCHED */ |
434d53b0 | 6896 | #ifdef CONFIG_RT_GROUP_SCHED |
07e06b01 | 6897 | root_task_group.rt_se = (struct sched_rt_entity **)ptr; |
434d53b0 MT |
6898 | ptr += nr_cpu_ids * sizeof(void **); |
6899 | ||
07e06b01 | 6900 | root_task_group.rt_rq = (struct rt_rq **)ptr; |
eff766a6 PZ |
6901 | ptr += nr_cpu_ids * sizeof(void **); |
6902 | ||
6d6bc0ad | 6903 | #endif /* CONFIG_RT_GROUP_SCHED */ |
df7c8e84 RR |
6904 | #ifdef CONFIG_CPUMASK_OFFSTACK |
6905 | for_each_possible_cpu(i) { | |
e6252c3e | 6906 | per_cpu(load_balance_mask, i) = (void *)ptr; |
df7c8e84 RR |
6907 | ptr += cpumask_size(); |
6908 | } | |
6909 | #endif /* CONFIG_CPUMASK_OFFSTACK */ | |
434d53b0 | 6910 | } |
dd41f596 | 6911 | |
332ac17e DF |
6912 | init_rt_bandwidth(&def_rt_bandwidth, |
6913 | global_rt_period(), global_rt_runtime()); | |
6914 | init_dl_bandwidth(&def_dl_bandwidth, | |
1724813d | 6915 | global_rt_period(), global_rt_runtime()); |
332ac17e | 6916 | |
57d885fe GH |
6917 | #ifdef CONFIG_SMP |
6918 | init_defrootdomain(); | |
6919 | #endif | |
6920 | ||
d0b27fa7 | 6921 | #ifdef CONFIG_RT_GROUP_SCHED |
07e06b01 | 6922 | init_rt_bandwidth(&root_task_group.rt_bandwidth, |
d0b27fa7 | 6923 | global_rt_period(), global_rt_runtime()); |
6d6bc0ad | 6924 | #endif /* CONFIG_RT_GROUP_SCHED */ |
d0b27fa7 | 6925 | |
7c941438 | 6926 | #ifdef CONFIG_CGROUP_SCHED |
07e06b01 YZ |
6927 | list_add(&root_task_group.list, &task_groups); |
6928 | INIT_LIST_HEAD(&root_task_group.children); | |
f4d6f6c2 | 6929 | INIT_LIST_HEAD(&root_task_group.siblings); |
5091faa4 | 6930 | autogroup_init(&init_task); |
54c707e9 | 6931 | |
7c941438 | 6932 | #endif /* CONFIG_CGROUP_SCHED */ |
6f505b16 | 6933 | |
0a945022 | 6934 | for_each_possible_cpu(i) { |
70b97a7f | 6935 | struct rq *rq; |
1da177e4 LT |
6936 | |
6937 | rq = cpu_rq(i); | |
05fa785c | 6938 | raw_spin_lock_init(&rq->lock); |
7897986b | 6939 | rq->nr_running = 0; |
dce48a84 TG |
6940 | rq->calc_load_active = 0; |
6941 | rq->calc_load_update = jiffies + LOAD_FREQ; | |
acb5a9ba | 6942 | init_cfs_rq(&rq->cfs); |
6f505b16 | 6943 | init_rt_rq(&rq->rt, rq); |
aab03e05 | 6944 | init_dl_rq(&rq->dl, rq); |
dd41f596 | 6945 | #ifdef CONFIG_FAIR_GROUP_SCHED |
029632fb | 6946 | root_task_group.shares = ROOT_TASK_GROUP_LOAD; |
6f505b16 | 6947 | INIT_LIST_HEAD(&rq->leaf_cfs_rq_list); |
354d60c2 | 6948 | /* |
07e06b01 | 6949 | * How much cpu bandwidth does root_task_group get? |
354d60c2 DG |
6950 | * |
6951 | * In case of task-groups formed thr' the cgroup filesystem, it | |
6952 | * gets 100% of the cpu resources in the system. This overall | |
6953 | * system cpu resource is divided among the tasks of | |
07e06b01 | 6954 | * root_task_group and its child task-groups in a fair manner, |
354d60c2 DG |
6955 | * based on each entity's (task or task-group's) weight |
6956 | * (se->load.weight). | |
6957 | * | |
07e06b01 | 6958 | * In other words, if root_task_group has 10 tasks of weight |
354d60c2 DG |
6959 | * 1024) and two child groups A0 and A1 (of weight 1024 each), |
6960 | * then A0's share of the cpu resource is: | |
6961 | * | |
0d905bca | 6962 | * A0's bandwidth = 1024 / (10*1024 + 1024 + 1024) = 8.33% |
354d60c2 | 6963 | * |
07e06b01 YZ |
6964 | * We achieve this by letting root_task_group's tasks sit |
6965 | * directly in rq->cfs (i.e root_task_group->se[] = NULL). | |
354d60c2 | 6966 | */ |
ab84d31e | 6967 | init_cfs_bandwidth(&root_task_group.cfs_bandwidth); |
07e06b01 | 6968 | init_tg_cfs_entry(&root_task_group, &rq->cfs, NULL, i, NULL); |
354d60c2 DG |
6969 | #endif /* CONFIG_FAIR_GROUP_SCHED */ |
6970 | ||
6971 | rq->rt.rt_runtime = def_rt_bandwidth.rt_runtime; | |
052f1dc7 | 6972 | #ifdef CONFIG_RT_GROUP_SCHED |
07e06b01 | 6973 | init_tg_rt_entry(&root_task_group, &rq->rt, NULL, i, NULL); |
dd41f596 | 6974 | #endif |
1da177e4 | 6975 | |
dd41f596 IM |
6976 | for (j = 0; j < CPU_LOAD_IDX_MAX; j++) |
6977 | rq->cpu_load[j] = 0; | |
fdf3e95d VP |
6978 | |
6979 | rq->last_load_update_tick = jiffies; | |
6980 | ||
1da177e4 | 6981 | #ifdef CONFIG_SMP |
41c7ce9a | 6982 | rq->sd = NULL; |
57d885fe | 6983 | rq->rd = NULL; |
ca8ce3d0 | 6984 | rq->cpu_capacity = SCHED_CAPACITY_SCALE; |
3f029d3c | 6985 | rq->post_schedule = 0; |
1da177e4 | 6986 | rq->active_balance = 0; |
dd41f596 | 6987 | rq->next_balance = jiffies; |
1da177e4 | 6988 | rq->push_cpu = 0; |
0a2966b4 | 6989 | rq->cpu = i; |
1f11eb6a | 6990 | rq->online = 0; |
eae0c9df MG |
6991 | rq->idle_stamp = 0; |
6992 | rq->avg_idle = 2*sysctl_sched_migration_cost; | |
9bd721c5 | 6993 | rq->max_idle_balance_cost = sysctl_sched_migration_cost; |
367456c7 PZ |
6994 | |
6995 | INIT_LIST_HEAD(&rq->cfs_tasks); | |
6996 | ||
dc938520 | 6997 | rq_attach_root(rq, &def_root_domain); |
3451d024 | 6998 | #ifdef CONFIG_NO_HZ_COMMON |
1c792db7 | 6999 | rq->nohz_flags = 0; |
83cd4fe2 | 7000 | #endif |
265f22a9 FW |
7001 | #ifdef CONFIG_NO_HZ_FULL |
7002 | rq->last_sched_tick = 0; | |
7003 | #endif | |
1da177e4 | 7004 | #endif |
8f4d37ec | 7005 | init_rq_hrtick(rq); |
1da177e4 | 7006 | atomic_set(&rq->nr_iowait, 0); |
1da177e4 LT |
7007 | } |
7008 | ||
2dd73a4f | 7009 | set_load_weight(&init_task); |
b50f60ce | 7010 | |
e107be36 AK |
7011 | #ifdef CONFIG_PREEMPT_NOTIFIERS |
7012 | INIT_HLIST_HEAD(&init_task.preempt_notifiers); | |
7013 | #endif | |
7014 | ||
1da177e4 LT |
7015 | /* |
7016 | * The boot idle thread does lazy MMU switching as well: | |
7017 | */ | |
7018 | atomic_inc(&init_mm.mm_count); | |
7019 | enter_lazy_tlb(&init_mm, current); | |
7020 | ||
7021 | /* | |
7022 | * Make us the idle thread. Technically, schedule() should not be | |
7023 | * called from this thread, however somewhere below it might be, | |
7024 | * but because we are the idle thread, we just pick up running again | |
7025 | * when this runqueue becomes "idle". | |
7026 | */ | |
7027 | init_idle(current, smp_processor_id()); | |
dce48a84 TG |
7028 | |
7029 | calc_load_update = jiffies + LOAD_FREQ; | |
7030 | ||
dd41f596 IM |
7031 | /* |
7032 | * During early bootup we pretend to be a normal task: | |
7033 | */ | |
7034 | current->sched_class = &fair_sched_class; | |
6892b75e | 7035 | |
bf4d83f6 | 7036 | #ifdef CONFIG_SMP |
4cb98839 | 7037 | zalloc_cpumask_var(&sched_domains_tmpmask, GFP_NOWAIT); |
bdddd296 RR |
7038 | /* May be allocated at isolcpus cmdline parse time */ |
7039 | if (cpu_isolated_map == NULL) | |
7040 | zalloc_cpumask_var(&cpu_isolated_map, GFP_NOWAIT); | |
29d5e047 | 7041 | idle_thread_set_boot_cpu(); |
a803f026 | 7042 | set_cpu_rq_start_time(); |
029632fb PZ |
7043 | #endif |
7044 | init_sched_fair_class(); | |
6a7b3dc3 | 7045 | |
6892b75e | 7046 | scheduler_running = 1; |
1da177e4 LT |
7047 | } |
7048 | ||
d902db1e | 7049 | #ifdef CONFIG_DEBUG_ATOMIC_SLEEP |
e4aafea2 FW |
7050 | static inline int preempt_count_equals(int preempt_offset) |
7051 | { | |
234da7bc | 7052 | int nested = (preempt_count() & ~PREEMPT_ACTIVE) + rcu_preempt_depth(); |
e4aafea2 | 7053 | |
4ba8216c | 7054 | return (nested == preempt_offset); |
e4aafea2 FW |
7055 | } |
7056 | ||
d894837f | 7057 | void __might_sleep(const char *file, int line, int preempt_offset) |
1da177e4 | 7058 | { |
1da177e4 LT |
7059 | static unsigned long prev_jiffy; /* ratelimiting */ |
7060 | ||
b3fbab05 | 7061 | rcu_sleep_check(); /* WARN_ON_ONCE() by default, no rate limit reqd. */ |
db273be2 TG |
7062 | if ((preempt_count_equals(preempt_offset) && !irqs_disabled() && |
7063 | !is_idle_task(current)) || | |
e4aafea2 | 7064 | system_state != SYSTEM_RUNNING || oops_in_progress) |
aef745fc IM |
7065 | return; |
7066 | if (time_before(jiffies, prev_jiffy + HZ) && prev_jiffy) | |
7067 | return; | |
7068 | prev_jiffy = jiffies; | |
7069 | ||
3df0fc5b PZ |
7070 | printk(KERN_ERR |
7071 | "BUG: sleeping function called from invalid context at %s:%d\n", | |
7072 | file, line); | |
7073 | printk(KERN_ERR | |
7074 | "in_atomic(): %d, irqs_disabled(): %d, pid: %d, name: %s\n", | |
7075 | in_atomic(), irqs_disabled(), | |
7076 | current->pid, current->comm); | |
aef745fc IM |
7077 | |
7078 | debug_show_held_locks(current); | |
7079 | if (irqs_disabled()) | |
7080 | print_irqtrace_events(current); | |
8f47b187 TG |
7081 | #ifdef CONFIG_DEBUG_PREEMPT |
7082 | if (!preempt_count_equals(preempt_offset)) { | |
7083 | pr_err("Preemption disabled at:"); | |
7084 | print_ip_sym(current->preempt_disable_ip); | |
7085 | pr_cont("\n"); | |
7086 | } | |
7087 | #endif | |
aef745fc | 7088 | dump_stack(); |
1da177e4 LT |
7089 | } |
7090 | EXPORT_SYMBOL(__might_sleep); | |
7091 | #endif | |
7092 | ||
7093 | #ifdef CONFIG_MAGIC_SYSRQ | |
3a5e4dc1 AK |
7094 | static void normalize_task(struct rq *rq, struct task_struct *p) |
7095 | { | |
da7a735e | 7096 | const struct sched_class *prev_class = p->sched_class; |
d50dde5a DF |
7097 | struct sched_attr attr = { |
7098 | .sched_policy = SCHED_NORMAL, | |
7099 | }; | |
da7a735e | 7100 | int old_prio = p->prio; |
3a5e4dc1 | 7101 | int on_rq; |
3e51f33f | 7102 | |
fd2f4419 | 7103 | on_rq = p->on_rq; |
3a5e4dc1 | 7104 | if (on_rq) |
4ca9b72b | 7105 | dequeue_task(rq, p, 0); |
d50dde5a | 7106 | __setscheduler(rq, p, &attr); |
3a5e4dc1 | 7107 | if (on_rq) { |
4ca9b72b | 7108 | enqueue_task(rq, p, 0); |
3a5e4dc1 AK |
7109 | resched_task(rq->curr); |
7110 | } | |
da7a735e PZ |
7111 | |
7112 | check_class_changed(rq, p, prev_class, old_prio); | |
3a5e4dc1 AK |
7113 | } |
7114 | ||
1da177e4 LT |
7115 | void normalize_rt_tasks(void) |
7116 | { | |
a0f98a1c | 7117 | struct task_struct *g, *p; |
1da177e4 | 7118 | unsigned long flags; |
70b97a7f | 7119 | struct rq *rq; |
1da177e4 | 7120 | |
4cf5d77a | 7121 | read_lock_irqsave(&tasklist_lock, flags); |
a0f98a1c | 7122 | do_each_thread(g, p) { |
178be793 IM |
7123 | /* |
7124 | * Only normalize user tasks: | |
7125 | */ | |
7126 | if (!p->mm) | |
7127 | continue; | |
7128 | ||
6cfb0d5d | 7129 | p->se.exec_start = 0; |
6cfb0d5d | 7130 | #ifdef CONFIG_SCHEDSTATS |
41acab88 LDM |
7131 | p->se.statistics.wait_start = 0; |
7132 | p->se.statistics.sleep_start = 0; | |
7133 | p->se.statistics.block_start = 0; | |
6cfb0d5d | 7134 | #endif |
dd41f596 | 7135 | |
aab03e05 | 7136 | if (!dl_task(p) && !rt_task(p)) { |
dd41f596 IM |
7137 | /* |
7138 | * Renice negative nice level userspace | |
7139 | * tasks back to 0: | |
7140 | */ | |
d0ea0268 | 7141 | if (task_nice(p) < 0 && p->mm) |
dd41f596 | 7142 | set_user_nice(p, 0); |
1da177e4 | 7143 | continue; |
dd41f596 | 7144 | } |
1da177e4 | 7145 | |
1d615482 | 7146 | raw_spin_lock(&p->pi_lock); |
b29739f9 | 7147 | rq = __task_rq_lock(p); |
1da177e4 | 7148 | |
178be793 | 7149 | normalize_task(rq, p); |
3a5e4dc1 | 7150 | |
b29739f9 | 7151 | __task_rq_unlock(rq); |
1d615482 | 7152 | raw_spin_unlock(&p->pi_lock); |
a0f98a1c IM |
7153 | } while_each_thread(g, p); |
7154 | ||
4cf5d77a | 7155 | read_unlock_irqrestore(&tasklist_lock, flags); |
1da177e4 LT |
7156 | } |
7157 | ||
7158 | #endif /* CONFIG_MAGIC_SYSRQ */ | |
1df5c10a | 7159 | |
67fc4e0c | 7160 | #if defined(CONFIG_IA64) || defined(CONFIG_KGDB_KDB) |
1df5c10a | 7161 | /* |
67fc4e0c | 7162 | * These functions are only useful for the IA64 MCA handling, or kdb. |
1df5c10a LT |
7163 | * |
7164 | * They can only be called when the whole system has been | |
7165 | * stopped - every CPU needs to be quiescent, and no scheduling | |
7166 | * activity can take place. Using them for anything else would | |
7167 | * be a serious bug, and as a result, they aren't even visible | |
7168 | * under any other configuration. | |
7169 | */ | |
7170 | ||
7171 | /** | |
7172 | * curr_task - return the current task for a given cpu. | |
7173 | * @cpu: the processor in question. | |
7174 | * | |
7175 | * ONLY VALID WHEN THE WHOLE SYSTEM IS STOPPED! | |
e69f6186 YB |
7176 | * |
7177 | * Return: The current task for @cpu. | |
1df5c10a | 7178 | */ |
36c8b586 | 7179 | struct task_struct *curr_task(int cpu) |
1df5c10a LT |
7180 | { |
7181 | return cpu_curr(cpu); | |
7182 | } | |
7183 | ||
67fc4e0c JW |
7184 | #endif /* defined(CONFIG_IA64) || defined(CONFIG_KGDB_KDB) */ |
7185 | ||
7186 | #ifdef CONFIG_IA64 | |
1df5c10a LT |
7187 | /** |
7188 | * set_curr_task - set the current task for a given cpu. | |
7189 | * @cpu: the processor in question. | |
7190 | * @p: the task pointer to set. | |
7191 | * | |
7192 | * Description: This function must only be used when non-maskable interrupts | |
41a2d6cf IM |
7193 | * are serviced on a separate stack. It allows the architecture to switch the |
7194 | * notion of the current task on a cpu in a non-blocking manner. This function | |
1df5c10a LT |
7195 | * must be called with all CPU's synchronized, and interrupts disabled, the |
7196 | * and caller must save the original value of the current task (see | |
7197 | * curr_task() above) and restore that value before reenabling interrupts and | |
7198 | * re-starting the system. | |
7199 | * | |
7200 | * ONLY VALID WHEN THE WHOLE SYSTEM IS STOPPED! | |
7201 | */ | |
36c8b586 | 7202 | void set_curr_task(int cpu, struct task_struct *p) |
1df5c10a LT |
7203 | { |
7204 | cpu_curr(cpu) = p; | |
7205 | } | |
7206 | ||
7207 | #endif | |
29f59db3 | 7208 | |
7c941438 | 7209 | #ifdef CONFIG_CGROUP_SCHED |
029632fb PZ |
7210 | /* task_group_lock serializes the addition/removal of task groups */ |
7211 | static DEFINE_SPINLOCK(task_group_lock); | |
7212 | ||
bccbe08a PZ |
7213 | static void free_sched_group(struct task_group *tg) |
7214 | { | |
7215 | free_fair_sched_group(tg); | |
7216 | free_rt_sched_group(tg); | |
e9aa1dd1 | 7217 | autogroup_free(tg); |
bccbe08a PZ |
7218 | kfree(tg); |
7219 | } | |
7220 | ||
7221 | /* allocate runqueue etc for a new task group */ | |
ec7dc8ac | 7222 | struct task_group *sched_create_group(struct task_group *parent) |
bccbe08a PZ |
7223 | { |
7224 | struct task_group *tg; | |
bccbe08a PZ |
7225 | |
7226 | tg = kzalloc(sizeof(*tg), GFP_KERNEL); | |
7227 | if (!tg) | |
7228 | return ERR_PTR(-ENOMEM); | |
7229 | ||
ec7dc8ac | 7230 | if (!alloc_fair_sched_group(tg, parent)) |
bccbe08a PZ |
7231 | goto err; |
7232 | ||
ec7dc8ac | 7233 | if (!alloc_rt_sched_group(tg, parent)) |
bccbe08a PZ |
7234 | goto err; |
7235 | ||
ace783b9 LZ |
7236 | return tg; |
7237 | ||
7238 | err: | |
7239 | free_sched_group(tg); | |
7240 | return ERR_PTR(-ENOMEM); | |
7241 | } | |
7242 | ||
7243 | void sched_online_group(struct task_group *tg, struct task_group *parent) | |
7244 | { | |
7245 | unsigned long flags; | |
7246 | ||
8ed36996 | 7247 | spin_lock_irqsave(&task_group_lock, flags); |
6f505b16 | 7248 | list_add_rcu(&tg->list, &task_groups); |
f473aa5e PZ |
7249 | |
7250 | WARN_ON(!parent); /* root should already exist */ | |
7251 | ||
7252 | tg->parent = parent; | |
f473aa5e | 7253 | INIT_LIST_HEAD(&tg->children); |
09f2724a | 7254 | list_add_rcu(&tg->siblings, &parent->children); |
8ed36996 | 7255 | spin_unlock_irqrestore(&task_group_lock, flags); |
29f59db3 SV |
7256 | } |
7257 | ||
9b5b7751 | 7258 | /* rcu callback to free various structures associated with a task group */ |
6f505b16 | 7259 | static void free_sched_group_rcu(struct rcu_head *rhp) |
29f59db3 | 7260 | { |
29f59db3 | 7261 | /* now it should be safe to free those cfs_rqs */ |
6f505b16 | 7262 | free_sched_group(container_of(rhp, struct task_group, rcu)); |
29f59db3 SV |
7263 | } |
7264 | ||
9b5b7751 | 7265 | /* Destroy runqueue etc associated with a task group */ |
4cf86d77 | 7266 | void sched_destroy_group(struct task_group *tg) |
ace783b9 LZ |
7267 | { |
7268 | /* wait for possible concurrent references to cfs_rqs complete */ | |
7269 | call_rcu(&tg->rcu, free_sched_group_rcu); | |
7270 | } | |
7271 | ||
7272 | void sched_offline_group(struct task_group *tg) | |
29f59db3 | 7273 | { |
8ed36996 | 7274 | unsigned long flags; |
9b5b7751 | 7275 | int i; |
29f59db3 | 7276 | |
3d4b47b4 PZ |
7277 | /* end participation in shares distribution */ |
7278 | for_each_possible_cpu(i) | |
bccbe08a | 7279 | unregister_fair_sched_group(tg, i); |
3d4b47b4 PZ |
7280 | |
7281 | spin_lock_irqsave(&task_group_lock, flags); | |
6f505b16 | 7282 | list_del_rcu(&tg->list); |
f473aa5e | 7283 | list_del_rcu(&tg->siblings); |
8ed36996 | 7284 | spin_unlock_irqrestore(&task_group_lock, flags); |
29f59db3 SV |
7285 | } |
7286 | ||
9b5b7751 | 7287 | /* change task's runqueue when it moves between groups. |
3a252015 IM |
7288 | * The caller of this function should have put the task in its new group |
7289 | * by now. This function just updates tsk->se.cfs_rq and tsk->se.parent to | |
7290 | * reflect its new group. | |
9b5b7751 SV |
7291 | */ |
7292 | void sched_move_task(struct task_struct *tsk) | |
29f59db3 | 7293 | { |
8323f26c | 7294 | struct task_group *tg; |
29f59db3 SV |
7295 | int on_rq, running; |
7296 | unsigned long flags; | |
7297 | struct rq *rq; | |
7298 | ||
7299 | rq = task_rq_lock(tsk, &flags); | |
7300 | ||
051a1d1a | 7301 | running = task_current(rq, tsk); |
fd2f4419 | 7302 | on_rq = tsk->on_rq; |
29f59db3 | 7303 | |
0e1f3483 | 7304 | if (on_rq) |
29f59db3 | 7305 | dequeue_task(rq, tsk, 0); |
0e1f3483 HS |
7306 | if (unlikely(running)) |
7307 | tsk->sched_class->put_prev_task(rq, tsk); | |
29f59db3 | 7308 | |
073219e9 | 7309 | tg = container_of(task_css_check(tsk, cpu_cgrp_id, |
8323f26c PZ |
7310 | lockdep_is_held(&tsk->sighand->siglock)), |
7311 | struct task_group, css); | |
7312 | tg = autogroup_task_group(tsk, tg); | |
7313 | tsk->sched_task_group = tg; | |
7314 | ||
810b3817 | 7315 | #ifdef CONFIG_FAIR_GROUP_SCHED |
b2b5ce02 PZ |
7316 | if (tsk->sched_class->task_move_group) |
7317 | tsk->sched_class->task_move_group(tsk, on_rq); | |
7318 | else | |
810b3817 | 7319 | #endif |
b2b5ce02 | 7320 | set_task_rq(tsk, task_cpu(tsk)); |
810b3817 | 7321 | |
0e1f3483 HS |
7322 | if (unlikely(running)) |
7323 | tsk->sched_class->set_curr_task(rq); | |
7324 | if (on_rq) | |
371fd7e7 | 7325 | enqueue_task(rq, tsk, 0); |
29f59db3 | 7326 | |
0122ec5b | 7327 | task_rq_unlock(rq, tsk, &flags); |
29f59db3 | 7328 | } |
7c941438 | 7329 | #endif /* CONFIG_CGROUP_SCHED */ |
29f59db3 | 7330 | |
a790de99 PT |
7331 | #ifdef CONFIG_RT_GROUP_SCHED |
7332 | /* | |
7333 | * Ensure that the real time constraints are schedulable. | |
7334 | */ | |
7335 | static DEFINE_MUTEX(rt_constraints_mutex); | |
9f0c1e56 | 7336 | |
9a7e0b18 PZ |
7337 | /* Must be called with tasklist_lock held */ |
7338 | static inline int tg_has_rt_tasks(struct task_group *tg) | |
b40b2e8e | 7339 | { |
9a7e0b18 | 7340 | struct task_struct *g, *p; |
b40b2e8e | 7341 | |
9a7e0b18 | 7342 | do_each_thread(g, p) { |
029632fb | 7343 | if (rt_task(p) && task_rq(p)->rt.tg == tg) |
9a7e0b18 PZ |
7344 | return 1; |
7345 | } while_each_thread(g, p); | |
b40b2e8e | 7346 | |
9a7e0b18 PZ |
7347 | return 0; |
7348 | } | |
b40b2e8e | 7349 | |
9a7e0b18 PZ |
7350 | struct rt_schedulable_data { |
7351 | struct task_group *tg; | |
7352 | u64 rt_period; | |
7353 | u64 rt_runtime; | |
7354 | }; | |
b40b2e8e | 7355 | |
a790de99 | 7356 | static int tg_rt_schedulable(struct task_group *tg, void *data) |
9a7e0b18 PZ |
7357 | { |
7358 | struct rt_schedulable_data *d = data; | |
7359 | struct task_group *child; | |
7360 | unsigned long total, sum = 0; | |
7361 | u64 period, runtime; | |
b40b2e8e | 7362 | |
9a7e0b18 PZ |
7363 | period = ktime_to_ns(tg->rt_bandwidth.rt_period); |
7364 | runtime = tg->rt_bandwidth.rt_runtime; | |
b40b2e8e | 7365 | |
9a7e0b18 PZ |
7366 | if (tg == d->tg) { |
7367 | period = d->rt_period; | |
7368 | runtime = d->rt_runtime; | |
b40b2e8e | 7369 | } |
b40b2e8e | 7370 | |
4653f803 PZ |
7371 | /* |
7372 | * Cannot have more runtime than the period. | |
7373 | */ | |
7374 | if (runtime > period && runtime != RUNTIME_INF) | |
7375 | return -EINVAL; | |
6f505b16 | 7376 | |
4653f803 PZ |
7377 | /* |
7378 | * Ensure we don't starve existing RT tasks. | |
7379 | */ | |
9a7e0b18 PZ |
7380 | if (rt_bandwidth_enabled() && !runtime && tg_has_rt_tasks(tg)) |
7381 | return -EBUSY; | |
6f505b16 | 7382 | |
9a7e0b18 | 7383 | total = to_ratio(period, runtime); |
6f505b16 | 7384 | |
4653f803 PZ |
7385 | /* |
7386 | * Nobody can have more than the global setting allows. | |
7387 | */ | |
7388 | if (total > to_ratio(global_rt_period(), global_rt_runtime())) | |
7389 | return -EINVAL; | |
6f505b16 | 7390 | |
4653f803 PZ |
7391 | /* |
7392 | * The sum of our children's runtime should not exceed our own. | |
7393 | */ | |
9a7e0b18 PZ |
7394 | list_for_each_entry_rcu(child, &tg->children, siblings) { |
7395 | period = ktime_to_ns(child->rt_bandwidth.rt_period); | |
7396 | runtime = child->rt_bandwidth.rt_runtime; | |
6f505b16 | 7397 | |
9a7e0b18 PZ |
7398 | if (child == d->tg) { |
7399 | period = d->rt_period; | |
7400 | runtime = d->rt_runtime; | |
7401 | } | |
6f505b16 | 7402 | |
9a7e0b18 | 7403 | sum += to_ratio(period, runtime); |
9f0c1e56 | 7404 | } |
6f505b16 | 7405 | |
9a7e0b18 PZ |
7406 | if (sum > total) |
7407 | return -EINVAL; | |
7408 | ||
7409 | return 0; | |
6f505b16 PZ |
7410 | } |
7411 | ||
9a7e0b18 | 7412 | static int __rt_schedulable(struct task_group *tg, u64 period, u64 runtime) |
521f1a24 | 7413 | { |
8277434e PT |
7414 | int ret; |
7415 | ||
9a7e0b18 PZ |
7416 | struct rt_schedulable_data data = { |
7417 | .tg = tg, | |
7418 | .rt_period = period, | |
7419 | .rt_runtime = runtime, | |
7420 | }; | |
7421 | ||
8277434e PT |
7422 | rcu_read_lock(); |
7423 | ret = walk_tg_tree(tg_rt_schedulable, tg_nop, &data); | |
7424 | rcu_read_unlock(); | |
7425 | ||
7426 | return ret; | |
521f1a24 DG |
7427 | } |
7428 | ||
ab84d31e | 7429 | static int tg_set_rt_bandwidth(struct task_group *tg, |
d0b27fa7 | 7430 | u64 rt_period, u64 rt_runtime) |
6f505b16 | 7431 | { |
ac086bc2 | 7432 | int i, err = 0; |
9f0c1e56 | 7433 | |
9f0c1e56 | 7434 | mutex_lock(&rt_constraints_mutex); |
521f1a24 | 7435 | read_lock(&tasklist_lock); |
9a7e0b18 PZ |
7436 | err = __rt_schedulable(tg, rt_period, rt_runtime); |
7437 | if (err) | |
9f0c1e56 | 7438 | goto unlock; |
ac086bc2 | 7439 | |
0986b11b | 7440 | raw_spin_lock_irq(&tg->rt_bandwidth.rt_runtime_lock); |
d0b27fa7 PZ |
7441 | tg->rt_bandwidth.rt_period = ns_to_ktime(rt_period); |
7442 | tg->rt_bandwidth.rt_runtime = rt_runtime; | |
ac086bc2 PZ |
7443 | |
7444 | for_each_possible_cpu(i) { | |
7445 | struct rt_rq *rt_rq = tg->rt_rq[i]; | |
7446 | ||
0986b11b | 7447 | raw_spin_lock(&rt_rq->rt_runtime_lock); |
ac086bc2 | 7448 | rt_rq->rt_runtime = rt_runtime; |
0986b11b | 7449 | raw_spin_unlock(&rt_rq->rt_runtime_lock); |
ac086bc2 | 7450 | } |
0986b11b | 7451 | raw_spin_unlock_irq(&tg->rt_bandwidth.rt_runtime_lock); |
49246274 | 7452 | unlock: |
521f1a24 | 7453 | read_unlock(&tasklist_lock); |
9f0c1e56 PZ |
7454 | mutex_unlock(&rt_constraints_mutex); |
7455 | ||
7456 | return err; | |
6f505b16 PZ |
7457 | } |
7458 | ||
25cc7da7 | 7459 | static int sched_group_set_rt_runtime(struct task_group *tg, long rt_runtime_us) |
d0b27fa7 PZ |
7460 | { |
7461 | u64 rt_runtime, rt_period; | |
7462 | ||
7463 | rt_period = ktime_to_ns(tg->rt_bandwidth.rt_period); | |
7464 | rt_runtime = (u64)rt_runtime_us * NSEC_PER_USEC; | |
7465 | if (rt_runtime_us < 0) | |
7466 | rt_runtime = RUNTIME_INF; | |
7467 | ||
ab84d31e | 7468 | return tg_set_rt_bandwidth(tg, rt_period, rt_runtime); |
d0b27fa7 PZ |
7469 | } |
7470 | ||
25cc7da7 | 7471 | static long sched_group_rt_runtime(struct task_group *tg) |
9f0c1e56 PZ |
7472 | { |
7473 | u64 rt_runtime_us; | |
7474 | ||
d0b27fa7 | 7475 | if (tg->rt_bandwidth.rt_runtime == RUNTIME_INF) |
9f0c1e56 PZ |
7476 | return -1; |
7477 | ||
d0b27fa7 | 7478 | rt_runtime_us = tg->rt_bandwidth.rt_runtime; |
9f0c1e56 PZ |
7479 | do_div(rt_runtime_us, NSEC_PER_USEC); |
7480 | return rt_runtime_us; | |
7481 | } | |
d0b27fa7 | 7482 | |
25cc7da7 | 7483 | static int sched_group_set_rt_period(struct task_group *tg, long rt_period_us) |
d0b27fa7 PZ |
7484 | { |
7485 | u64 rt_runtime, rt_period; | |
7486 | ||
7487 | rt_period = (u64)rt_period_us * NSEC_PER_USEC; | |
7488 | rt_runtime = tg->rt_bandwidth.rt_runtime; | |
7489 | ||
619b0488 R |
7490 | if (rt_period == 0) |
7491 | return -EINVAL; | |
7492 | ||
ab84d31e | 7493 | return tg_set_rt_bandwidth(tg, rt_period, rt_runtime); |
d0b27fa7 PZ |
7494 | } |
7495 | ||
25cc7da7 | 7496 | static long sched_group_rt_period(struct task_group *tg) |
d0b27fa7 PZ |
7497 | { |
7498 | u64 rt_period_us; | |
7499 | ||
7500 | rt_period_us = ktime_to_ns(tg->rt_bandwidth.rt_period); | |
7501 | do_div(rt_period_us, NSEC_PER_USEC); | |
7502 | return rt_period_us; | |
7503 | } | |
332ac17e | 7504 | #endif /* CONFIG_RT_GROUP_SCHED */ |
d0b27fa7 | 7505 | |
332ac17e | 7506 | #ifdef CONFIG_RT_GROUP_SCHED |
d0b27fa7 PZ |
7507 | static int sched_rt_global_constraints(void) |
7508 | { | |
7509 | int ret = 0; | |
7510 | ||
7511 | mutex_lock(&rt_constraints_mutex); | |
9a7e0b18 | 7512 | read_lock(&tasklist_lock); |
4653f803 | 7513 | ret = __rt_schedulable(NULL, 0, 0); |
9a7e0b18 | 7514 | read_unlock(&tasklist_lock); |
d0b27fa7 PZ |
7515 | mutex_unlock(&rt_constraints_mutex); |
7516 | ||
7517 | return ret; | |
7518 | } | |
54e99124 | 7519 | |
25cc7da7 | 7520 | static int sched_rt_can_attach(struct task_group *tg, struct task_struct *tsk) |
54e99124 DG |
7521 | { |
7522 | /* Don't accept realtime tasks when there is no way for them to run */ | |
7523 | if (rt_task(tsk) && tg->rt_bandwidth.rt_runtime == 0) | |
7524 | return 0; | |
7525 | ||
7526 | return 1; | |
7527 | } | |
7528 | ||
6d6bc0ad | 7529 | #else /* !CONFIG_RT_GROUP_SCHED */ |
d0b27fa7 PZ |
7530 | static int sched_rt_global_constraints(void) |
7531 | { | |
ac086bc2 | 7532 | unsigned long flags; |
332ac17e | 7533 | int i, ret = 0; |
ec5d4989 | 7534 | |
0986b11b | 7535 | raw_spin_lock_irqsave(&def_rt_bandwidth.rt_runtime_lock, flags); |
ac086bc2 PZ |
7536 | for_each_possible_cpu(i) { |
7537 | struct rt_rq *rt_rq = &cpu_rq(i)->rt; | |
7538 | ||
0986b11b | 7539 | raw_spin_lock(&rt_rq->rt_runtime_lock); |
ac086bc2 | 7540 | rt_rq->rt_runtime = global_rt_runtime(); |
0986b11b | 7541 | raw_spin_unlock(&rt_rq->rt_runtime_lock); |
ac086bc2 | 7542 | } |
0986b11b | 7543 | raw_spin_unlock_irqrestore(&def_rt_bandwidth.rt_runtime_lock, flags); |
ac086bc2 | 7544 | |
332ac17e | 7545 | return ret; |
d0b27fa7 | 7546 | } |
6d6bc0ad | 7547 | #endif /* CONFIG_RT_GROUP_SCHED */ |
d0b27fa7 | 7548 | |
332ac17e DF |
7549 | static int sched_dl_global_constraints(void) |
7550 | { | |
1724813d PZ |
7551 | u64 runtime = global_rt_runtime(); |
7552 | u64 period = global_rt_period(); | |
332ac17e | 7553 | u64 new_bw = to_ratio(period, runtime); |
1724813d | 7554 | int cpu, ret = 0; |
49516342 | 7555 | unsigned long flags; |
332ac17e DF |
7556 | |
7557 | /* | |
7558 | * Here we want to check the bandwidth not being set to some | |
7559 | * value smaller than the currently allocated bandwidth in | |
7560 | * any of the root_domains. | |
7561 | * | |
7562 | * FIXME: Cycling on all the CPUs is overdoing, but simpler than | |
7563 | * cycling on root_domains... Discussion on different/better | |
7564 | * solutions is welcome! | |
7565 | */ | |
1724813d PZ |
7566 | for_each_possible_cpu(cpu) { |
7567 | struct dl_bw *dl_b = dl_bw_of(cpu); | |
332ac17e | 7568 | |
49516342 | 7569 | raw_spin_lock_irqsave(&dl_b->lock, flags); |
1724813d PZ |
7570 | if (new_bw < dl_b->total_bw) |
7571 | ret = -EBUSY; | |
49516342 | 7572 | raw_spin_unlock_irqrestore(&dl_b->lock, flags); |
1724813d PZ |
7573 | |
7574 | if (ret) | |
7575 | break; | |
332ac17e DF |
7576 | } |
7577 | ||
1724813d | 7578 | return ret; |
332ac17e DF |
7579 | } |
7580 | ||
1724813d | 7581 | static void sched_dl_do_global(void) |
ce0dbbbb | 7582 | { |
1724813d PZ |
7583 | u64 new_bw = -1; |
7584 | int cpu; | |
49516342 | 7585 | unsigned long flags; |
ce0dbbbb | 7586 | |
1724813d PZ |
7587 | def_dl_bandwidth.dl_period = global_rt_period(); |
7588 | def_dl_bandwidth.dl_runtime = global_rt_runtime(); | |
7589 | ||
7590 | if (global_rt_runtime() != RUNTIME_INF) | |
7591 | new_bw = to_ratio(global_rt_period(), global_rt_runtime()); | |
7592 | ||
7593 | /* | |
7594 | * FIXME: As above... | |
7595 | */ | |
7596 | for_each_possible_cpu(cpu) { | |
7597 | struct dl_bw *dl_b = dl_bw_of(cpu); | |
7598 | ||
49516342 | 7599 | raw_spin_lock_irqsave(&dl_b->lock, flags); |
1724813d | 7600 | dl_b->bw = new_bw; |
49516342 | 7601 | raw_spin_unlock_irqrestore(&dl_b->lock, flags); |
ce0dbbbb | 7602 | } |
1724813d PZ |
7603 | } |
7604 | ||
7605 | static int sched_rt_global_validate(void) | |
7606 | { | |
7607 | if (sysctl_sched_rt_period <= 0) | |
7608 | return -EINVAL; | |
7609 | ||
e9e7cb38 JL |
7610 | if ((sysctl_sched_rt_runtime != RUNTIME_INF) && |
7611 | (sysctl_sched_rt_runtime > sysctl_sched_rt_period)) | |
1724813d PZ |
7612 | return -EINVAL; |
7613 | ||
7614 | return 0; | |
7615 | } | |
7616 | ||
7617 | static void sched_rt_do_global(void) | |
7618 | { | |
7619 | def_rt_bandwidth.rt_runtime = global_rt_runtime(); | |
7620 | def_rt_bandwidth.rt_period = ns_to_ktime(global_rt_period()); | |
ce0dbbbb CW |
7621 | } |
7622 | ||
d0b27fa7 | 7623 | int sched_rt_handler(struct ctl_table *table, int write, |
8d65af78 | 7624 | void __user *buffer, size_t *lenp, |
d0b27fa7 PZ |
7625 | loff_t *ppos) |
7626 | { | |
d0b27fa7 PZ |
7627 | int old_period, old_runtime; |
7628 | static DEFINE_MUTEX(mutex); | |
1724813d | 7629 | int ret; |
d0b27fa7 PZ |
7630 | |
7631 | mutex_lock(&mutex); | |
7632 | old_period = sysctl_sched_rt_period; | |
7633 | old_runtime = sysctl_sched_rt_runtime; | |
7634 | ||
8d65af78 | 7635 | ret = proc_dointvec(table, write, buffer, lenp, ppos); |
d0b27fa7 PZ |
7636 | |
7637 | if (!ret && write) { | |
1724813d PZ |
7638 | ret = sched_rt_global_validate(); |
7639 | if (ret) | |
7640 | goto undo; | |
7641 | ||
d0b27fa7 | 7642 | ret = sched_rt_global_constraints(); |
1724813d PZ |
7643 | if (ret) |
7644 | goto undo; | |
7645 | ||
7646 | ret = sched_dl_global_constraints(); | |
7647 | if (ret) | |
7648 | goto undo; | |
7649 | ||
7650 | sched_rt_do_global(); | |
7651 | sched_dl_do_global(); | |
7652 | } | |
7653 | if (0) { | |
7654 | undo: | |
7655 | sysctl_sched_rt_period = old_period; | |
7656 | sysctl_sched_rt_runtime = old_runtime; | |
d0b27fa7 PZ |
7657 | } |
7658 | mutex_unlock(&mutex); | |
7659 | ||
7660 | return ret; | |
7661 | } | |
68318b8e | 7662 | |
1724813d | 7663 | int sched_rr_handler(struct ctl_table *table, int write, |
332ac17e DF |
7664 | void __user *buffer, size_t *lenp, |
7665 | loff_t *ppos) | |
7666 | { | |
7667 | int ret; | |
332ac17e | 7668 | static DEFINE_MUTEX(mutex); |
332ac17e DF |
7669 | |
7670 | mutex_lock(&mutex); | |
332ac17e | 7671 | ret = proc_dointvec(table, write, buffer, lenp, ppos); |
1724813d PZ |
7672 | /* make sure that internally we keep jiffies */ |
7673 | /* also, writing zero resets timeslice to default */ | |
332ac17e | 7674 | if (!ret && write) { |
1724813d PZ |
7675 | sched_rr_timeslice = sched_rr_timeslice <= 0 ? |
7676 | RR_TIMESLICE : msecs_to_jiffies(sched_rr_timeslice); | |
332ac17e DF |
7677 | } |
7678 | mutex_unlock(&mutex); | |
332ac17e DF |
7679 | return ret; |
7680 | } | |
7681 | ||
052f1dc7 | 7682 | #ifdef CONFIG_CGROUP_SCHED |
68318b8e | 7683 | |
a7c6d554 | 7684 | static inline struct task_group *css_tg(struct cgroup_subsys_state *css) |
68318b8e | 7685 | { |
a7c6d554 | 7686 | return css ? container_of(css, struct task_group, css) : NULL; |
68318b8e SV |
7687 | } |
7688 | ||
eb95419b TH |
7689 | static struct cgroup_subsys_state * |
7690 | cpu_cgroup_css_alloc(struct cgroup_subsys_state *parent_css) | |
68318b8e | 7691 | { |
eb95419b TH |
7692 | struct task_group *parent = css_tg(parent_css); |
7693 | struct task_group *tg; | |
68318b8e | 7694 | |
eb95419b | 7695 | if (!parent) { |
68318b8e | 7696 | /* This is early initialization for the top cgroup */ |
07e06b01 | 7697 | return &root_task_group.css; |
68318b8e SV |
7698 | } |
7699 | ||
ec7dc8ac | 7700 | tg = sched_create_group(parent); |
68318b8e SV |
7701 | if (IS_ERR(tg)) |
7702 | return ERR_PTR(-ENOMEM); | |
7703 | ||
68318b8e SV |
7704 | return &tg->css; |
7705 | } | |
7706 | ||
eb95419b | 7707 | static int cpu_cgroup_css_online(struct cgroup_subsys_state *css) |
ace783b9 | 7708 | { |
eb95419b | 7709 | struct task_group *tg = css_tg(css); |
5c9d535b | 7710 | struct task_group *parent = css_tg(css->parent); |
ace783b9 | 7711 | |
63876986 TH |
7712 | if (parent) |
7713 | sched_online_group(tg, parent); | |
ace783b9 LZ |
7714 | return 0; |
7715 | } | |
7716 | ||
eb95419b | 7717 | static void cpu_cgroup_css_free(struct cgroup_subsys_state *css) |
68318b8e | 7718 | { |
eb95419b | 7719 | struct task_group *tg = css_tg(css); |
68318b8e SV |
7720 | |
7721 | sched_destroy_group(tg); | |
7722 | } | |
7723 | ||
eb95419b | 7724 | static void cpu_cgroup_css_offline(struct cgroup_subsys_state *css) |
ace783b9 | 7725 | { |
eb95419b | 7726 | struct task_group *tg = css_tg(css); |
ace783b9 LZ |
7727 | |
7728 | sched_offline_group(tg); | |
7729 | } | |
7730 | ||
eb95419b | 7731 | static int cpu_cgroup_can_attach(struct cgroup_subsys_state *css, |
bb9d97b6 | 7732 | struct cgroup_taskset *tset) |
68318b8e | 7733 | { |
bb9d97b6 TH |
7734 | struct task_struct *task; |
7735 | ||
924f0d9a | 7736 | cgroup_taskset_for_each(task, tset) { |
b68aa230 | 7737 | #ifdef CONFIG_RT_GROUP_SCHED |
eb95419b | 7738 | if (!sched_rt_can_attach(css_tg(css), task)) |
bb9d97b6 | 7739 | return -EINVAL; |
b68aa230 | 7740 | #else |
bb9d97b6 TH |
7741 | /* We don't support RT-tasks being in separate groups */ |
7742 | if (task->sched_class != &fair_sched_class) | |
7743 | return -EINVAL; | |
b68aa230 | 7744 | #endif |
bb9d97b6 | 7745 | } |
be367d09 BB |
7746 | return 0; |
7747 | } | |
68318b8e | 7748 | |
eb95419b | 7749 | static void cpu_cgroup_attach(struct cgroup_subsys_state *css, |
bb9d97b6 | 7750 | struct cgroup_taskset *tset) |
68318b8e | 7751 | { |
bb9d97b6 TH |
7752 | struct task_struct *task; |
7753 | ||
924f0d9a | 7754 | cgroup_taskset_for_each(task, tset) |
bb9d97b6 | 7755 | sched_move_task(task); |
68318b8e SV |
7756 | } |
7757 | ||
eb95419b TH |
7758 | static void cpu_cgroup_exit(struct cgroup_subsys_state *css, |
7759 | struct cgroup_subsys_state *old_css, | |
7760 | struct task_struct *task) | |
068c5cc5 PZ |
7761 | { |
7762 | /* | |
7763 | * cgroup_exit() is called in the copy_process() failure path. | |
7764 | * Ignore this case since the task hasn't ran yet, this avoids | |
7765 | * trying to poke a half freed task state from generic code. | |
7766 | */ | |
7767 | if (!(task->flags & PF_EXITING)) | |
7768 | return; | |
7769 | ||
7770 | sched_move_task(task); | |
7771 | } | |
7772 | ||
052f1dc7 | 7773 | #ifdef CONFIG_FAIR_GROUP_SCHED |
182446d0 TH |
7774 | static int cpu_shares_write_u64(struct cgroup_subsys_state *css, |
7775 | struct cftype *cftype, u64 shareval) | |
68318b8e | 7776 | { |
182446d0 | 7777 | return sched_group_set_shares(css_tg(css), scale_load(shareval)); |
68318b8e SV |
7778 | } |
7779 | ||
182446d0 TH |
7780 | static u64 cpu_shares_read_u64(struct cgroup_subsys_state *css, |
7781 | struct cftype *cft) | |
68318b8e | 7782 | { |
182446d0 | 7783 | struct task_group *tg = css_tg(css); |
68318b8e | 7784 | |
c8b28116 | 7785 | return (u64) scale_load_down(tg->shares); |
68318b8e | 7786 | } |
ab84d31e PT |
7787 | |
7788 | #ifdef CONFIG_CFS_BANDWIDTH | |
a790de99 PT |
7789 | static DEFINE_MUTEX(cfs_constraints_mutex); |
7790 | ||
ab84d31e PT |
7791 | const u64 max_cfs_quota_period = 1 * NSEC_PER_SEC; /* 1s */ |
7792 | const u64 min_cfs_quota_period = 1 * NSEC_PER_MSEC; /* 1ms */ | |
7793 | ||
a790de99 PT |
7794 | static int __cfs_schedulable(struct task_group *tg, u64 period, u64 runtime); |
7795 | ||
ab84d31e PT |
7796 | static int tg_set_cfs_bandwidth(struct task_group *tg, u64 period, u64 quota) |
7797 | { | |
56f570e5 | 7798 | int i, ret = 0, runtime_enabled, runtime_was_enabled; |
029632fb | 7799 | struct cfs_bandwidth *cfs_b = &tg->cfs_bandwidth; |
ab84d31e PT |
7800 | |
7801 | if (tg == &root_task_group) | |
7802 | return -EINVAL; | |
7803 | ||
7804 | /* | |
7805 | * Ensure we have at some amount of bandwidth every period. This is | |
7806 | * to prevent reaching a state of large arrears when throttled via | |
7807 | * entity_tick() resulting in prolonged exit starvation. | |
7808 | */ | |
7809 | if (quota < min_cfs_quota_period || period < min_cfs_quota_period) | |
7810 | return -EINVAL; | |
7811 | ||
7812 | /* | |
7813 | * Likewise, bound things on the otherside by preventing insane quota | |
7814 | * periods. This also allows us to normalize in computing quota | |
7815 | * feasibility. | |
7816 | */ | |
7817 | if (period > max_cfs_quota_period) | |
7818 | return -EINVAL; | |
7819 | ||
0e59bdae KT |
7820 | /* |
7821 | * Prevent race between setting of cfs_rq->runtime_enabled and | |
7822 | * unthrottle_offline_cfs_rqs(). | |
7823 | */ | |
7824 | get_online_cpus(); | |
a790de99 PT |
7825 | mutex_lock(&cfs_constraints_mutex); |
7826 | ret = __cfs_schedulable(tg, period, quota); | |
7827 | if (ret) | |
7828 | goto out_unlock; | |
7829 | ||
58088ad0 | 7830 | runtime_enabled = quota != RUNTIME_INF; |
56f570e5 | 7831 | runtime_was_enabled = cfs_b->quota != RUNTIME_INF; |
1ee14e6c BS |
7832 | /* |
7833 | * If we need to toggle cfs_bandwidth_used, off->on must occur | |
7834 | * before making related changes, and on->off must occur afterwards | |
7835 | */ | |
7836 | if (runtime_enabled && !runtime_was_enabled) | |
7837 | cfs_bandwidth_usage_inc(); | |
ab84d31e PT |
7838 | raw_spin_lock_irq(&cfs_b->lock); |
7839 | cfs_b->period = ns_to_ktime(period); | |
7840 | cfs_b->quota = quota; | |
58088ad0 | 7841 | |
a9cf55b2 | 7842 | __refill_cfs_bandwidth_runtime(cfs_b); |
58088ad0 PT |
7843 | /* restart the period timer (if active) to handle new period expiry */ |
7844 | if (runtime_enabled && cfs_b->timer_active) { | |
7845 | /* force a reprogram */ | |
09dc4ab0 | 7846 | __start_cfs_bandwidth(cfs_b, true); |
58088ad0 | 7847 | } |
ab84d31e PT |
7848 | raw_spin_unlock_irq(&cfs_b->lock); |
7849 | ||
0e59bdae | 7850 | for_each_online_cpu(i) { |
ab84d31e | 7851 | struct cfs_rq *cfs_rq = tg->cfs_rq[i]; |
029632fb | 7852 | struct rq *rq = cfs_rq->rq; |
ab84d31e PT |
7853 | |
7854 | raw_spin_lock_irq(&rq->lock); | |
58088ad0 | 7855 | cfs_rq->runtime_enabled = runtime_enabled; |
ab84d31e | 7856 | cfs_rq->runtime_remaining = 0; |
671fd9da | 7857 | |
029632fb | 7858 | if (cfs_rq->throttled) |
671fd9da | 7859 | unthrottle_cfs_rq(cfs_rq); |
ab84d31e PT |
7860 | raw_spin_unlock_irq(&rq->lock); |
7861 | } | |
1ee14e6c BS |
7862 | if (runtime_was_enabled && !runtime_enabled) |
7863 | cfs_bandwidth_usage_dec(); | |
a790de99 PT |
7864 | out_unlock: |
7865 | mutex_unlock(&cfs_constraints_mutex); | |
0e59bdae | 7866 | put_online_cpus(); |
ab84d31e | 7867 | |
a790de99 | 7868 | return ret; |
ab84d31e PT |
7869 | } |
7870 | ||
7871 | int tg_set_cfs_quota(struct task_group *tg, long cfs_quota_us) | |
7872 | { | |
7873 | u64 quota, period; | |
7874 | ||
029632fb | 7875 | period = ktime_to_ns(tg->cfs_bandwidth.period); |
ab84d31e PT |
7876 | if (cfs_quota_us < 0) |
7877 | quota = RUNTIME_INF; | |
7878 | else | |
7879 | quota = (u64)cfs_quota_us * NSEC_PER_USEC; | |
7880 | ||
7881 | return tg_set_cfs_bandwidth(tg, period, quota); | |
7882 | } | |
7883 | ||
7884 | long tg_get_cfs_quota(struct task_group *tg) | |
7885 | { | |
7886 | u64 quota_us; | |
7887 | ||
029632fb | 7888 | if (tg->cfs_bandwidth.quota == RUNTIME_INF) |
ab84d31e PT |
7889 | return -1; |
7890 | ||
029632fb | 7891 | quota_us = tg->cfs_bandwidth.quota; |
ab84d31e PT |
7892 | do_div(quota_us, NSEC_PER_USEC); |
7893 | ||
7894 | return quota_us; | |
7895 | } | |
7896 | ||
7897 | int tg_set_cfs_period(struct task_group *tg, long cfs_period_us) | |
7898 | { | |
7899 | u64 quota, period; | |
7900 | ||
7901 | period = (u64)cfs_period_us * NSEC_PER_USEC; | |
029632fb | 7902 | quota = tg->cfs_bandwidth.quota; |
ab84d31e | 7903 | |
ab84d31e PT |
7904 | return tg_set_cfs_bandwidth(tg, period, quota); |
7905 | } | |
7906 | ||
7907 | long tg_get_cfs_period(struct task_group *tg) | |
7908 | { | |
7909 | u64 cfs_period_us; | |
7910 | ||
029632fb | 7911 | cfs_period_us = ktime_to_ns(tg->cfs_bandwidth.period); |
ab84d31e PT |
7912 | do_div(cfs_period_us, NSEC_PER_USEC); |
7913 | ||
7914 | return cfs_period_us; | |
7915 | } | |
7916 | ||
182446d0 TH |
7917 | static s64 cpu_cfs_quota_read_s64(struct cgroup_subsys_state *css, |
7918 | struct cftype *cft) | |
ab84d31e | 7919 | { |
182446d0 | 7920 | return tg_get_cfs_quota(css_tg(css)); |
ab84d31e PT |
7921 | } |
7922 | ||
182446d0 TH |
7923 | static int cpu_cfs_quota_write_s64(struct cgroup_subsys_state *css, |
7924 | struct cftype *cftype, s64 cfs_quota_us) | |
ab84d31e | 7925 | { |
182446d0 | 7926 | return tg_set_cfs_quota(css_tg(css), cfs_quota_us); |
ab84d31e PT |
7927 | } |
7928 | ||
182446d0 TH |
7929 | static u64 cpu_cfs_period_read_u64(struct cgroup_subsys_state *css, |
7930 | struct cftype *cft) | |
ab84d31e | 7931 | { |
182446d0 | 7932 | return tg_get_cfs_period(css_tg(css)); |
ab84d31e PT |
7933 | } |
7934 | ||
182446d0 TH |
7935 | static int cpu_cfs_period_write_u64(struct cgroup_subsys_state *css, |
7936 | struct cftype *cftype, u64 cfs_period_us) | |
ab84d31e | 7937 | { |
182446d0 | 7938 | return tg_set_cfs_period(css_tg(css), cfs_period_us); |
ab84d31e PT |
7939 | } |
7940 | ||
a790de99 PT |
7941 | struct cfs_schedulable_data { |
7942 | struct task_group *tg; | |
7943 | u64 period, quota; | |
7944 | }; | |
7945 | ||
7946 | /* | |
7947 | * normalize group quota/period to be quota/max_period | |
7948 | * note: units are usecs | |
7949 | */ | |
7950 | static u64 normalize_cfs_quota(struct task_group *tg, | |
7951 | struct cfs_schedulable_data *d) | |
7952 | { | |
7953 | u64 quota, period; | |
7954 | ||
7955 | if (tg == d->tg) { | |
7956 | period = d->period; | |
7957 | quota = d->quota; | |
7958 | } else { | |
7959 | period = tg_get_cfs_period(tg); | |
7960 | quota = tg_get_cfs_quota(tg); | |
7961 | } | |
7962 | ||
7963 | /* note: these should typically be equivalent */ | |
7964 | if (quota == RUNTIME_INF || quota == -1) | |
7965 | return RUNTIME_INF; | |
7966 | ||
7967 | return to_ratio(period, quota); | |
7968 | } | |
7969 | ||
7970 | static int tg_cfs_schedulable_down(struct task_group *tg, void *data) | |
7971 | { | |
7972 | struct cfs_schedulable_data *d = data; | |
029632fb | 7973 | struct cfs_bandwidth *cfs_b = &tg->cfs_bandwidth; |
a790de99 PT |
7974 | s64 quota = 0, parent_quota = -1; |
7975 | ||
7976 | if (!tg->parent) { | |
7977 | quota = RUNTIME_INF; | |
7978 | } else { | |
029632fb | 7979 | struct cfs_bandwidth *parent_b = &tg->parent->cfs_bandwidth; |
a790de99 PT |
7980 | |
7981 | quota = normalize_cfs_quota(tg, d); | |
7982 | parent_quota = parent_b->hierarchal_quota; | |
7983 | ||
7984 | /* | |
7985 | * ensure max(child_quota) <= parent_quota, inherit when no | |
7986 | * limit is set | |
7987 | */ | |
7988 | if (quota == RUNTIME_INF) | |
7989 | quota = parent_quota; | |
7990 | else if (parent_quota != RUNTIME_INF && quota > parent_quota) | |
7991 | return -EINVAL; | |
7992 | } | |
7993 | cfs_b->hierarchal_quota = quota; | |
7994 | ||
7995 | return 0; | |
7996 | } | |
7997 | ||
7998 | static int __cfs_schedulable(struct task_group *tg, u64 period, u64 quota) | |
7999 | { | |
8277434e | 8000 | int ret; |
a790de99 PT |
8001 | struct cfs_schedulable_data data = { |
8002 | .tg = tg, | |
8003 | .period = period, | |
8004 | .quota = quota, | |
8005 | }; | |
8006 | ||
8007 | if (quota != RUNTIME_INF) { | |
8008 | do_div(data.period, NSEC_PER_USEC); | |
8009 | do_div(data.quota, NSEC_PER_USEC); | |
8010 | } | |
8011 | ||
8277434e PT |
8012 | rcu_read_lock(); |
8013 | ret = walk_tg_tree(tg_cfs_schedulable_down, tg_nop, &data); | |
8014 | rcu_read_unlock(); | |
8015 | ||
8016 | return ret; | |
a790de99 | 8017 | } |
e8da1b18 | 8018 | |
2da8ca82 | 8019 | static int cpu_stats_show(struct seq_file *sf, void *v) |
e8da1b18 | 8020 | { |
2da8ca82 | 8021 | struct task_group *tg = css_tg(seq_css(sf)); |
029632fb | 8022 | struct cfs_bandwidth *cfs_b = &tg->cfs_bandwidth; |
e8da1b18 | 8023 | |
44ffc75b TH |
8024 | seq_printf(sf, "nr_periods %d\n", cfs_b->nr_periods); |
8025 | seq_printf(sf, "nr_throttled %d\n", cfs_b->nr_throttled); | |
8026 | seq_printf(sf, "throttled_time %llu\n", cfs_b->throttled_time); | |
e8da1b18 NR |
8027 | |
8028 | return 0; | |
8029 | } | |
ab84d31e | 8030 | #endif /* CONFIG_CFS_BANDWIDTH */ |
6d6bc0ad | 8031 | #endif /* CONFIG_FAIR_GROUP_SCHED */ |
68318b8e | 8032 | |
052f1dc7 | 8033 | #ifdef CONFIG_RT_GROUP_SCHED |
182446d0 TH |
8034 | static int cpu_rt_runtime_write(struct cgroup_subsys_state *css, |
8035 | struct cftype *cft, s64 val) | |
6f505b16 | 8036 | { |
182446d0 | 8037 | return sched_group_set_rt_runtime(css_tg(css), val); |
6f505b16 PZ |
8038 | } |
8039 | ||
182446d0 TH |
8040 | static s64 cpu_rt_runtime_read(struct cgroup_subsys_state *css, |
8041 | struct cftype *cft) | |
6f505b16 | 8042 | { |
182446d0 | 8043 | return sched_group_rt_runtime(css_tg(css)); |
6f505b16 | 8044 | } |
d0b27fa7 | 8045 | |
182446d0 TH |
8046 | static int cpu_rt_period_write_uint(struct cgroup_subsys_state *css, |
8047 | struct cftype *cftype, u64 rt_period_us) | |
d0b27fa7 | 8048 | { |
182446d0 | 8049 | return sched_group_set_rt_period(css_tg(css), rt_period_us); |
d0b27fa7 PZ |
8050 | } |
8051 | ||
182446d0 TH |
8052 | static u64 cpu_rt_period_read_uint(struct cgroup_subsys_state *css, |
8053 | struct cftype *cft) | |
d0b27fa7 | 8054 | { |
182446d0 | 8055 | return sched_group_rt_period(css_tg(css)); |
d0b27fa7 | 8056 | } |
6d6bc0ad | 8057 | #endif /* CONFIG_RT_GROUP_SCHED */ |
6f505b16 | 8058 | |
fe5c7cc2 | 8059 | static struct cftype cpu_files[] = { |
052f1dc7 | 8060 | #ifdef CONFIG_FAIR_GROUP_SCHED |
fe5c7cc2 PM |
8061 | { |
8062 | .name = "shares", | |
f4c753b7 PM |
8063 | .read_u64 = cpu_shares_read_u64, |
8064 | .write_u64 = cpu_shares_write_u64, | |
fe5c7cc2 | 8065 | }, |
052f1dc7 | 8066 | #endif |
ab84d31e PT |
8067 | #ifdef CONFIG_CFS_BANDWIDTH |
8068 | { | |
8069 | .name = "cfs_quota_us", | |
8070 | .read_s64 = cpu_cfs_quota_read_s64, | |
8071 | .write_s64 = cpu_cfs_quota_write_s64, | |
8072 | }, | |
8073 | { | |
8074 | .name = "cfs_period_us", | |
8075 | .read_u64 = cpu_cfs_period_read_u64, | |
8076 | .write_u64 = cpu_cfs_period_write_u64, | |
8077 | }, | |
e8da1b18 NR |
8078 | { |
8079 | .name = "stat", | |
2da8ca82 | 8080 | .seq_show = cpu_stats_show, |
e8da1b18 | 8081 | }, |
ab84d31e | 8082 | #endif |
052f1dc7 | 8083 | #ifdef CONFIG_RT_GROUP_SCHED |
6f505b16 | 8084 | { |
9f0c1e56 | 8085 | .name = "rt_runtime_us", |
06ecb27c PM |
8086 | .read_s64 = cpu_rt_runtime_read, |
8087 | .write_s64 = cpu_rt_runtime_write, | |
6f505b16 | 8088 | }, |
d0b27fa7 PZ |
8089 | { |
8090 | .name = "rt_period_us", | |
f4c753b7 PM |
8091 | .read_u64 = cpu_rt_period_read_uint, |
8092 | .write_u64 = cpu_rt_period_write_uint, | |
d0b27fa7 | 8093 | }, |
052f1dc7 | 8094 | #endif |
4baf6e33 | 8095 | { } /* terminate */ |
68318b8e SV |
8096 | }; |
8097 | ||
073219e9 | 8098 | struct cgroup_subsys cpu_cgrp_subsys = { |
92fb9748 TH |
8099 | .css_alloc = cpu_cgroup_css_alloc, |
8100 | .css_free = cpu_cgroup_css_free, | |
ace783b9 LZ |
8101 | .css_online = cpu_cgroup_css_online, |
8102 | .css_offline = cpu_cgroup_css_offline, | |
bb9d97b6 TH |
8103 | .can_attach = cpu_cgroup_can_attach, |
8104 | .attach = cpu_cgroup_attach, | |
068c5cc5 | 8105 | .exit = cpu_cgroup_exit, |
4baf6e33 | 8106 | .base_cftypes = cpu_files, |
68318b8e SV |
8107 | .early_init = 1, |
8108 | }; | |
8109 | ||
052f1dc7 | 8110 | #endif /* CONFIG_CGROUP_SCHED */ |
d842de87 | 8111 | |
b637a328 PM |
8112 | void dump_cpu_task(int cpu) |
8113 | { | |
8114 | pr_info("Task dump for CPU %d:\n", cpu); | |
8115 | sched_show_task(cpu_curr(cpu)); | |
8116 | } |