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 | |
029632fb | 93 | void start_bandwidth_timer(struct hrtimer *period_timer, ktime_t period) |
d0b27fa7 | 94 | { |
58088ad0 PT |
95 | unsigned long delta; |
96 | ktime_t soft, hard, now; | |
d0b27fa7 | 97 | |
58088ad0 PT |
98 | for (;;) { |
99 | if (hrtimer_active(period_timer)) | |
100 | break; | |
101 | ||
102 | now = hrtimer_cb_get_time(period_timer); | |
103 | hrtimer_forward(period_timer, now, period); | |
d0b27fa7 | 104 | |
58088ad0 PT |
105 | soft = hrtimer_get_softexpires(period_timer); |
106 | hard = hrtimer_get_expires(period_timer); | |
107 | delta = ktime_to_ns(ktime_sub(hard, soft)); | |
108 | __hrtimer_start_range_ns(period_timer, soft, delta, | |
109 | HRTIMER_MODE_ABS_PINNED, 0); | |
110 | } | |
111 | } | |
112 | ||
029632fb PZ |
113 | DEFINE_MUTEX(sched_domains_mutex); |
114 | DEFINE_PER_CPU_SHARED_ALIGNED(struct rq, runqueues); | |
dc61b1d6 | 115 | |
fe44d621 | 116 | static void update_rq_clock_task(struct rq *rq, s64 delta); |
305e6835 | 117 | |
029632fb | 118 | void update_rq_clock(struct rq *rq) |
3e51f33f | 119 | { |
fe44d621 | 120 | s64 delta; |
305e6835 | 121 | |
9edfbfed PZ |
122 | lockdep_assert_held(&rq->lock); |
123 | ||
124 | if (rq->clock_skip_update & RQCF_ACT_SKIP) | |
f26f9aff | 125 | return; |
aa483808 | 126 | |
fe44d621 | 127 | delta = sched_clock_cpu(cpu_of(rq)) - rq->clock; |
4036ac15 MG |
128 | if (delta < 0) |
129 | return; | |
fe44d621 PZ |
130 | rq->clock += delta; |
131 | update_rq_clock_task(rq, delta); | |
3e51f33f PZ |
132 | } |
133 | ||
bf5c91ba IM |
134 | /* |
135 | * Debugging: various feature bits | |
136 | */ | |
f00b45c1 | 137 | |
f00b45c1 PZ |
138 | #define SCHED_FEAT(name, enabled) \ |
139 | (1UL << __SCHED_FEAT_##name) * enabled | | |
140 | ||
bf5c91ba | 141 | const_debug unsigned int sysctl_sched_features = |
391e43da | 142 | #include "features.h" |
f00b45c1 PZ |
143 | 0; |
144 | ||
145 | #undef SCHED_FEAT | |
146 | ||
147 | #ifdef CONFIG_SCHED_DEBUG | |
148 | #define SCHED_FEAT(name, enabled) \ | |
149 | #name , | |
150 | ||
1292531f | 151 | static const char * const sched_feat_names[] = { |
391e43da | 152 | #include "features.h" |
f00b45c1 PZ |
153 | }; |
154 | ||
155 | #undef SCHED_FEAT | |
156 | ||
34f3a814 | 157 | static int sched_feat_show(struct seq_file *m, void *v) |
f00b45c1 | 158 | { |
f00b45c1 PZ |
159 | int i; |
160 | ||
f8b6d1cc | 161 | for (i = 0; i < __SCHED_FEAT_NR; i++) { |
34f3a814 LZ |
162 | if (!(sysctl_sched_features & (1UL << i))) |
163 | seq_puts(m, "NO_"); | |
164 | seq_printf(m, "%s ", sched_feat_names[i]); | |
f00b45c1 | 165 | } |
34f3a814 | 166 | seq_puts(m, "\n"); |
f00b45c1 | 167 | |
34f3a814 | 168 | return 0; |
f00b45c1 PZ |
169 | } |
170 | ||
f8b6d1cc PZ |
171 | #ifdef HAVE_JUMP_LABEL |
172 | ||
c5905afb IM |
173 | #define jump_label_key__true STATIC_KEY_INIT_TRUE |
174 | #define jump_label_key__false STATIC_KEY_INIT_FALSE | |
f8b6d1cc PZ |
175 | |
176 | #define SCHED_FEAT(name, enabled) \ | |
177 | jump_label_key__##enabled , | |
178 | ||
c5905afb | 179 | struct static_key sched_feat_keys[__SCHED_FEAT_NR] = { |
f8b6d1cc PZ |
180 | #include "features.h" |
181 | }; | |
182 | ||
183 | #undef SCHED_FEAT | |
184 | ||
185 | static void sched_feat_disable(int i) | |
186 | { | |
c5905afb IM |
187 | if (static_key_enabled(&sched_feat_keys[i])) |
188 | static_key_slow_dec(&sched_feat_keys[i]); | |
f8b6d1cc PZ |
189 | } |
190 | ||
191 | static void sched_feat_enable(int i) | |
192 | { | |
c5905afb IM |
193 | if (!static_key_enabled(&sched_feat_keys[i])) |
194 | static_key_slow_inc(&sched_feat_keys[i]); | |
f8b6d1cc PZ |
195 | } |
196 | #else | |
197 | static void sched_feat_disable(int i) { }; | |
198 | static void sched_feat_enable(int i) { }; | |
199 | #endif /* HAVE_JUMP_LABEL */ | |
200 | ||
1a687c2e | 201 | static int sched_feat_set(char *cmp) |
f00b45c1 | 202 | { |
f00b45c1 | 203 | int i; |
1a687c2e | 204 | int neg = 0; |
f00b45c1 | 205 | |
524429c3 | 206 | if (strncmp(cmp, "NO_", 3) == 0) { |
f00b45c1 PZ |
207 | neg = 1; |
208 | cmp += 3; | |
209 | } | |
210 | ||
f8b6d1cc | 211 | for (i = 0; i < __SCHED_FEAT_NR; i++) { |
7740191c | 212 | if (strcmp(cmp, sched_feat_names[i]) == 0) { |
f8b6d1cc | 213 | if (neg) { |
f00b45c1 | 214 | sysctl_sched_features &= ~(1UL << i); |
f8b6d1cc PZ |
215 | sched_feat_disable(i); |
216 | } else { | |
f00b45c1 | 217 | sysctl_sched_features |= (1UL << i); |
f8b6d1cc PZ |
218 | sched_feat_enable(i); |
219 | } | |
f00b45c1 PZ |
220 | break; |
221 | } | |
222 | } | |
223 | ||
1a687c2e MG |
224 | return i; |
225 | } | |
226 | ||
227 | static ssize_t | |
228 | sched_feat_write(struct file *filp, const char __user *ubuf, | |
229 | size_t cnt, loff_t *ppos) | |
230 | { | |
231 | char buf[64]; | |
232 | char *cmp; | |
233 | int i; | |
5cd08fbf | 234 | struct inode *inode; |
1a687c2e MG |
235 | |
236 | if (cnt > 63) | |
237 | cnt = 63; | |
238 | ||
239 | if (copy_from_user(&buf, ubuf, cnt)) | |
240 | return -EFAULT; | |
241 | ||
242 | buf[cnt] = 0; | |
243 | cmp = strstrip(buf); | |
244 | ||
5cd08fbf JB |
245 | /* Ensure the static_key remains in a consistent state */ |
246 | inode = file_inode(filp); | |
247 | mutex_lock(&inode->i_mutex); | |
1a687c2e | 248 | i = sched_feat_set(cmp); |
5cd08fbf | 249 | mutex_unlock(&inode->i_mutex); |
f8b6d1cc | 250 | if (i == __SCHED_FEAT_NR) |
f00b45c1 PZ |
251 | return -EINVAL; |
252 | ||
42994724 | 253 | *ppos += cnt; |
f00b45c1 PZ |
254 | |
255 | return cnt; | |
256 | } | |
257 | ||
34f3a814 LZ |
258 | static int sched_feat_open(struct inode *inode, struct file *filp) |
259 | { | |
260 | return single_open(filp, sched_feat_show, NULL); | |
261 | } | |
262 | ||
828c0950 | 263 | static const struct file_operations sched_feat_fops = { |
34f3a814 LZ |
264 | .open = sched_feat_open, |
265 | .write = sched_feat_write, | |
266 | .read = seq_read, | |
267 | .llseek = seq_lseek, | |
268 | .release = single_release, | |
f00b45c1 PZ |
269 | }; |
270 | ||
271 | static __init int sched_init_debug(void) | |
272 | { | |
f00b45c1 PZ |
273 | debugfs_create_file("sched_features", 0644, NULL, NULL, |
274 | &sched_feat_fops); | |
275 | ||
276 | return 0; | |
277 | } | |
278 | late_initcall(sched_init_debug); | |
f8b6d1cc | 279 | #endif /* CONFIG_SCHED_DEBUG */ |
bf5c91ba | 280 | |
b82d9fdd PZ |
281 | /* |
282 | * Number of tasks to iterate in a single balance run. | |
283 | * Limited because this is done with IRQs disabled. | |
284 | */ | |
285 | const_debug unsigned int sysctl_sched_nr_migrate = 32; | |
286 | ||
e9e9250b PZ |
287 | /* |
288 | * period over which we average the RT time consumption, measured | |
289 | * in ms. | |
290 | * | |
291 | * default: 1s | |
292 | */ | |
293 | const_debug unsigned int sysctl_sched_time_avg = MSEC_PER_SEC; | |
294 | ||
fa85ae24 | 295 | /* |
9f0c1e56 | 296 | * period over which we measure -rt task cpu usage in us. |
fa85ae24 PZ |
297 | * default: 1s |
298 | */ | |
9f0c1e56 | 299 | unsigned int sysctl_sched_rt_period = 1000000; |
fa85ae24 | 300 | |
029632fb | 301 | __read_mostly int scheduler_running; |
6892b75e | 302 | |
9f0c1e56 PZ |
303 | /* |
304 | * part of the period that we allow rt tasks to run in us. | |
305 | * default: 0.95s | |
306 | */ | |
307 | int sysctl_sched_rt_runtime = 950000; | |
fa85ae24 | 308 | |
0970d299 | 309 | /* |
0122ec5b | 310 | * __task_rq_lock - lock the rq @p resides on. |
b29739f9 | 311 | */ |
70b97a7f | 312 | static inline struct rq *__task_rq_lock(struct task_struct *p) |
b29739f9 IM |
313 | __acquires(rq->lock) |
314 | { | |
0970d299 PZ |
315 | struct rq *rq; |
316 | ||
0122ec5b PZ |
317 | lockdep_assert_held(&p->pi_lock); |
318 | ||
3a5c359a | 319 | for (;;) { |
0970d299 | 320 | rq = task_rq(p); |
05fa785c | 321 | raw_spin_lock(&rq->lock); |
cca26e80 | 322 | if (likely(rq == task_rq(p) && !task_on_rq_migrating(p))) |
3a5c359a | 323 | return rq; |
05fa785c | 324 | raw_spin_unlock(&rq->lock); |
cca26e80 KT |
325 | |
326 | while (unlikely(task_on_rq_migrating(p))) | |
327 | cpu_relax(); | |
b29739f9 | 328 | } |
b29739f9 IM |
329 | } |
330 | ||
1da177e4 | 331 | /* |
0122ec5b | 332 | * task_rq_lock - lock p->pi_lock and lock the rq @p resides on. |
1da177e4 | 333 | */ |
70b97a7f | 334 | static struct rq *task_rq_lock(struct task_struct *p, unsigned long *flags) |
0122ec5b | 335 | __acquires(p->pi_lock) |
1da177e4 LT |
336 | __acquires(rq->lock) |
337 | { | |
70b97a7f | 338 | struct rq *rq; |
1da177e4 | 339 | |
3a5c359a | 340 | for (;;) { |
0122ec5b | 341 | raw_spin_lock_irqsave(&p->pi_lock, *flags); |
3a5c359a | 342 | rq = task_rq(p); |
05fa785c | 343 | raw_spin_lock(&rq->lock); |
cca26e80 | 344 | if (likely(rq == task_rq(p) && !task_on_rq_migrating(p))) |
3a5c359a | 345 | return rq; |
0122ec5b PZ |
346 | raw_spin_unlock(&rq->lock); |
347 | raw_spin_unlock_irqrestore(&p->pi_lock, *flags); | |
cca26e80 KT |
348 | |
349 | while (unlikely(task_on_rq_migrating(p))) | |
350 | cpu_relax(); | |
1da177e4 | 351 | } |
1da177e4 LT |
352 | } |
353 | ||
a9957449 | 354 | static void __task_rq_unlock(struct rq *rq) |
b29739f9 IM |
355 | __releases(rq->lock) |
356 | { | |
05fa785c | 357 | raw_spin_unlock(&rq->lock); |
b29739f9 IM |
358 | } |
359 | ||
0122ec5b PZ |
360 | static inline void |
361 | task_rq_unlock(struct rq *rq, struct task_struct *p, unsigned long *flags) | |
1da177e4 | 362 | __releases(rq->lock) |
0122ec5b | 363 | __releases(p->pi_lock) |
1da177e4 | 364 | { |
0122ec5b PZ |
365 | raw_spin_unlock(&rq->lock); |
366 | raw_spin_unlock_irqrestore(&p->pi_lock, *flags); | |
1da177e4 LT |
367 | } |
368 | ||
1da177e4 | 369 | /* |
cc2a73b5 | 370 | * this_rq_lock - lock this runqueue and disable interrupts. |
1da177e4 | 371 | */ |
a9957449 | 372 | static struct rq *this_rq_lock(void) |
1da177e4 LT |
373 | __acquires(rq->lock) |
374 | { | |
70b97a7f | 375 | struct rq *rq; |
1da177e4 LT |
376 | |
377 | local_irq_disable(); | |
378 | rq = this_rq(); | |
05fa785c | 379 | raw_spin_lock(&rq->lock); |
1da177e4 LT |
380 | |
381 | return rq; | |
382 | } | |
383 | ||
8f4d37ec PZ |
384 | #ifdef CONFIG_SCHED_HRTICK |
385 | /* | |
386 | * Use HR-timers to deliver accurate preemption points. | |
8f4d37ec | 387 | */ |
8f4d37ec | 388 | |
8f4d37ec PZ |
389 | static void hrtick_clear(struct rq *rq) |
390 | { | |
391 | if (hrtimer_active(&rq->hrtick_timer)) | |
392 | hrtimer_cancel(&rq->hrtick_timer); | |
393 | } | |
394 | ||
8f4d37ec PZ |
395 | /* |
396 | * High-resolution timer tick. | |
397 | * Runs from hardirq context with interrupts disabled. | |
398 | */ | |
399 | static enum hrtimer_restart hrtick(struct hrtimer *timer) | |
400 | { | |
401 | struct rq *rq = container_of(timer, struct rq, hrtick_timer); | |
402 | ||
403 | WARN_ON_ONCE(cpu_of(rq) != smp_processor_id()); | |
404 | ||
05fa785c | 405 | raw_spin_lock(&rq->lock); |
3e51f33f | 406 | update_rq_clock(rq); |
8f4d37ec | 407 | rq->curr->sched_class->task_tick(rq, rq->curr, 1); |
05fa785c | 408 | raw_spin_unlock(&rq->lock); |
8f4d37ec PZ |
409 | |
410 | return HRTIMER_NORESTART; | |
411 | } | |
412 | ||
95e904c7 | 413 | #ifdef CONFIG_SMP |
971ee28c PZ |
414 | |
415 | static int __hrtick_restart(struct rq *rq) | |
416 | { | |
417 | struct hrtimer *timer = &rq->hrtick_timer; | |
418 | ktime_t time = hrtimer_get_softexpires(timer); | |
419 | ||
420 | return __hrtimer_start_range_ns(timer, time, 0, HRTIMER_MODE_ABS_PINNED, 0); | |
421 | } | |
422 | ||
31656519 PZ |
423 | /* |
424 | * called from hardirq (IPI) context | |
425 | */ | |
426 | static void __hrtick_start(void *arg) | |
b328ca18 | 427 | { |
31656519 | 428 | struct rq *rq = arg; |
b328ca18 | 429 | |
05fa785c | 430 | raw_spin_lock(&rq->lock); |
971ee28c | 431 | __hrtick_restart(rq); |
31656519 | 432 | rq->hrtick_csd_pending = 0; |
05fa785c | 433 | raw_spin_unlock(&rq->lock); |
b328ca18 PZ |
434 | } |
435 | ||
31656519 PZ |
436 | /* |
437 | * Called to set the hrtick timer state. | |
438 | * | |
439 | * called with rq->lock held and irqs disabled | |
440 | */ | |
029632fb | 441 | void hrtick_start(struct rq *rq, u64 delay) |
b328ca18 | 442 | { |
31656519 | 443 | struct hrtimer *timer = &rq->hrtick_timer; |
177ef2a6 | 444 | ktime_t time; |
445 | s64 delta; | |
446 | ||
447 | /* | |
448 | * Don't schedule slices shorter than 10000ns, that just | |
449 | * doesn't make sense and can cause timer DoS. | |
450 | */ | |
451 | delta = max_t(s64, delay, 10000LL); | |
452 | time = ktime_add_ns(timer->base->get_time(), delta); | |
b328ca18 | 453 | |
cc584b21 | 454 | hrtimer_set_expires(timer, time); |
31656519 PZ |
455 | |
456 | if (rq == this_rq()) { | |
971ee28c | 457 | __hrtick_restart(rq); |
31656519 | 458 | } else if (!rq->hrtick_csd_pending) { |
c46fff2a | 459 | smp_call_function_single_async(cpu_of(rq), &rq->hrtick_csd); |
31656519 PZ |
460 | rq->hrtick_csd_pending = 1; |
461 | } | |
b328ca18 PZ |
462 | } |
463 | ||
464 | static int | |
465 | hotplug_hrtick(struct notifier_block *nfb, unsigned long action, void *hcpu) | |
466 | { | |
467 | int cpu = (int)(long)hcpu; | |
468 | ||
469 | switch (action) { | |
470 | case CPU_UP_CANCELED: | |
471 | case CPU_UP_CANCELED_FROZEN: | |
472 | case CPU_DOWN_PREPARE: | |
473 | case CPU_DOWN_PREPARE_FROZEN: | |
474 | case CPU_DEAD: | |
475 | case CPU_DEAD_FROZEN: | |
31656519 | 476 | hrtick_clear(cpu_rq(cpu)); |
b328ca18 PZ |
477 | return NOTIFY_OK; |
478 | } | |
479 | ||
480 | return NOTIFY_DONE; | |
481 | } | |
482 | ||
fa748203 | 483 | static __init void init_hrtick(void) |
b328ca18 PZ |
484 | { |
485 | hotcpu_notifier(hotplug_hrtick, 0); | |
486 | } | |
31656519 PZ |
487 | #else |
488 | /* | |
489 | * Called to set the hrtick timer state. | |
490 | * | |
491 | * called with rq->lock held and irqs disabled | |
492 | */ | |
029632fb | 493 | void hrtick_start(struct rq *rq, u64 delay) |
31656519 | 494 | { |
7f1e2ca9 | 495 | __hrtimer_start_range_ns(&rq->hrtick_timer, ns_to_ktime(delay), 0, |
5c333864 | 496 | HRTIMER_MODE_REL_PINNED, 0); |
31656519 | 497 | } |
b328ca18 | 498 | |
006c75f1 | 499 | static inline void init_hrtick(void) |
8f4d37ec | 500 | { |
8f4d37ec | 501 | } |
31656519 | 502 | #endif /* CONFIG_SMP */ |
8f4d37ec | 503 | |
31656519 | 504 | static void init_rq_hrtick(struct rq *rq) |
8f4d37ec | 505 | { |
31656519 PZ |
506 | #ifdef CONFIG_SMP |
507 | rq->hrtick_csd_pending = 0; | |
8f4d37ec | 508 | |
31656519 PZ |
509 | rq->hrtick_csd.flags = 0; |
510 | rq->hrtick_csd.func = __hrtick_start; | |
511 | rq->hrtick_csd.info = rq; | |
512 | #endif | |
8f4d37ec | 513 | |
31656519 PZ |
514 | hrtimer_init(&rq->hrtick_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); |
515 | rq->hrtick_timer.function = hrtick; | |
8f4d37ec | 516 | } |
006c75f1 | 517 | #else /* CONFIG_SCHED_HRTICK */ |
8f4d37ec PZ |
518 | static inline void hrtick_clear(struct rq *rq) |
519 | { | |
520 | } | |
521 | ||
8f4d37ec PZ |
522 | static inline void init_rq_hrtick(struct rq *rq) |
523 | { | |
524 | } | |
525 | ||
b328ca18 PZ |
526 | static inline void init_hrtick(void) |
527 | { | |
528 | } | |
006c75f1 | 529 | #endif /* CONFIG_SCHED_HRTICK */ |
8f4d37ec | 530 | |
fd99f91a PZ |
531 | /* |
532 | * cmpxchg based fetch_or, macro so it works for different integer types | |
533 | */ | |
534 | #define fetch_or(ptr, val) \ | |
535 | ({ typeof(*(ptr)) __old, __val = *(ptr); \ | |
536 | for (;;) { \ | |
537 | __old = cmpxchg((ptr), __val, __val | (val)); \ | |
538 | if (__old == __val) \ | |
539 | break; \ | |
540 | __val = __old; \ | |
541 | } \ | |
542 | __old; \ | |
543 | }) | |
544 | ||
e3baac47 | 545 | #if defined(CONFIG_SMP) && defined(TIF_POLLING_NRFLAG) |
fd99f91a PZ |
546 | /* |
547 | * Atomically set TIF_NEED_RESCHED and test for TIF_POLLING_NRFLAG, | |
548 | * this avoids any races wrt polling state changes and thereby avoids | |
549 | * spurious IPIs. | |
550 | */ | |
551 | static bool set_nr_and_not_polling(struct task_struct *p) | |
552 | { | |
553 | struct thread_info *ti = task_thread_info(p); | |
554 | return !(fetch_or(&ti->flags, _TIF_NEED_RESCHED) & _TIF_POLLING_NRFLAG); | |
555 | } | |
e3baac47 PZ |
556 | |
557 | /* | |
558 | * Atomically set TIF_NEED_RESCHED if TIF_POLLING_NRFLAG is set. | |
559 | * | |
560 | * If this returns true, then the idle task promises to call | |
561 | * sched_ttwu_pending() and reschedule soon. | |
562 | */ | |
563 | static bool set_nr_if_polling(struct task_struct *p) | |
564 | { | |
565 | struct thread_info *ti = task_thread_info(p); | |
566 | typeof(ti->flags) old, val = ACCESS_ONCE(ti->flags); | |
567 | ||
568 | for (;;) { | |
569 | if (!(val & _TIF_POLLING_NRFLAG)) | |
570 | return false; | |
571 | if (val & _TIF_NEED_RESCHED) | |
572 | return true; | |
573 | old = cmpxchg(&ti->flags, val, val | _TIF_NEED_RESCHED); | |
574 | if (old == val) | |
575 | break; | |
576 | val = old; | |
577 | } | |
578 | return true; | |
579 | } | |
580 | ||
fd99f91a PZ |
581 | #else |
582 | static bool set_nr_and_not_polling(struct task_struct *p) | |
583 | { | |
584 | set_tsk_need_resched(p); | |
585 | return true; | |
586 | } | |
e3baac47 PZ |
587 | |
588 | #ifdef CONFIG_SMP | |
589 | static bool set_nr_if_polling(struct task_struct *p) | |
590 | { | |
591 | return false; | |
592 | } | |
593 | #endif | |
fd99f91a PZ |
594 | #endif |
595 | ||
c24d20db | 596 | /* |
8875125e | 597 | * resched_curr - mark rq's current task 'to be rescheduled now'. |
c24d20db IM |
598 | * |
599 | * On UP this means the setting of the need_resched flag, on SMP it | |
600 | * might also involve a cross-CPU call to trigger the scheduler on | |
601 | * the target CPU. | |
602 | */ | |
8875125e | 603 | void resched_curr(struct rq *rq) |
c24d20db | 604 | { |
8875125e | 605 | struct task_struct *curr = rq->curr; |
c24d20db IM |
606 | int cpu; |
607 | ||
8875125e | 608 | lockdep_assert_held(&rq->lock); |
c24d20db | 609 | |
8875125e | 610 | if (test_tsk_need_resched(curr)) |
c24d20db IM |
611 | return; |
612 | ||
8875125e | 613 | cpu = cpu_of(rq); |
fd99f91a | 614 | |
f27dde8d | 615 | if (cpu == smp_processor_id()) { |
8875125e | 616 | set_tsk_need_resched(curr); |
f27dde8d | 617 | set_preempt_need_resched(); |
c24d20db | 618 | return; |
f27dde8d | 619 | } |
c24d20db | 620 | |
8875125e | 621 | if (set_nr_and_not_polling(curr)) |
c24d20db | 622 | smp_send_reschedule(cpu); |
dfc68f29 AL |
623 | else |
624 | trace_sched_wake_idle_without_ipi(cpu); | |
c24d20db IM |
625 | } |
626 | ||
029632fb | 627 | void resched_cpu(int cpu) |
c24d20db IM |
628 | { |
629 | struct rq *rq = cpu_rq(cpu); | |
630 | unsigned long flags; | |
631 | ||
05fa785c | 632 | if (!raw_spin_trylock_irqsave(&rq->lock, flags)) |
c24d20db | 633 | return; |
8875125e | 634 | resched_curr(rq); |
05fa785c | 635 | raw_spin_unlock_irqrestore(&rq->lock, flags); |
c24d20db | 636 | } |
06d8308c | 637 | |
b021fe3e | 638 | #ifdef CONFIG_SMP |
3451d024 | 639 | #ifdef CONFIG_NO_HZ_COMMON |
83cd4fe2 VP |
640 | /* |
641 | * In the semi idle case, use the nearest busy cpu for migrating timers | |
642 | * from an idle cpu. This is good for power-savings. | |
643 | * | |
644 | * We don't do similar optimization for completely idle system, as | |
645 | * selecting an idle cpu will add more delays to the timers than intended | |
646 | * (as that cpu's timer base may not be uptodate wrt jiffies etc). | |
647 | */ | |
6201b4d6 | 648 | int get_nohz_timer_target(int pinned) |
83cd4fe2 VP |
649 | { |
650 | int cpu = smp_processor_id(); | |
651 | int i; | |
652 | struct sched_domain *sd; | |
653 | ||
6201b4d6 VK |
654 | if (pinned || !get_sysctl_timer_migration() || !idle_cpu(cpu)) |
655 | return cpu; | |
656 | ||
057f3fad | 657 | rcu_read_lock(); |
83cd4fe2 | 658 | for_each_domain(cpu, sd) { |
057f3fad PZ |
659 | for_each_cpu(i, sched_domain_span(sd)) { |
660 | if (!idle_cpu(i)) { | |
661 | cpu = i; | |
662 | goto unlock; | |
663 | } | |
664 | } | |
83cd4fe2 | 665 | } |
057f3fad PZ |
666 | unlock: |
667 | rcu_read_unlock(); | |
83cd4fe2 VP |
668 | return cpu; |
669 | } | |
06d8308c TG |
670 | /* |
671 | * When add_timer_on() enqueues a timer into the timer wheel of an | |
672 | * idle CPU then this timer might expire before the next timer event | |
673 | * which is scheduled to wake up that CPU. In case of a completely | |
674 | * idle system the next event might even be infinite time into the | |
675 | * future. wake_up_idle_cpu() ensures that the CPU is woken up and | |
676 | * leaves the inner idle loop so the newly added timer is taken into | |
677 | * account when the CPU goes back to idle and evaluates the timer | |
678 | * wheel for the next timer event. | |
679 | */ | |
1c20091e | 680 | static void wake_up_idle_cpu(int cpu) |
06d8308c TG |
681 | { |
682 | struct rq *rq = cpu_rq(cpu); | |
683 | ||
684 | if (cpu == smp_processor_id()) | |
685 | return; | |
686 | ||
67b9ca70 | 687 | if (set_nr_and_not_polling(rq->idle)) |
06d8308c | 688 | smp_send_reschedule(cpu); |
dfc68f29 AL |
689 | else |
690 | trace_sched_wake_idle_without_ipi(cpu); | |
45bf76df IM |
691 | } |
692 | ||
c5bfece2 | 693 | static bool wake_up_full_nohz_cpu(int cpu) |
1c20091e | 694 | { |
53c5fa16 FW |
695 | /* |
696 | * We just need the target to call irq_exit() and re-evaluate | |
697 | * the next tick. The nohz full kick at least implies that. | |
698 | * If needed we can still optimize that later with an | |
699 | * empty IRQ. | |
700 | */ | |
c5bfece2 | 701 | if (tick_nohz_full_cpu(cpu)) { |
1c20091e FW |
702 | if (cpu != smp_processor_id() || |
703 | tick_nohz_tick_stopped()) | |
53c5fa16 | 704 | tick_nohz_full_kick_cpu(cpu); |
1c20091e FW |
705 | return true; |
706 | } | |
707 | ||
708 | return false; | |
709 | } | |
710 | ||
711 | void wake_up_nohz_cpu(int cpu) | |
712 | { | |
c5bfece2 | 713 | if (!wake_up_full_nohz_cpu(cpu)) |
1c20091e FW |
714 | wake_up_idle_cpu(cpu); |
715 | } | |
716 | ||
ca38062e | 717 | static inline bool got_nohz_idle_kick(void) |
45bf76df | 718 | { |
1c792db7 | 719 | int cpu = smp_processor_id(); |
873b4c65 VG |
720 | |
721 | if (!test_bit(NOHZ_BALANCE_KICK, nohz_flags(cpu))) | |
722 | return false; | |
723 | ||
724 | if (idle_cpu(cpu) && !need_resched()) | |
725 | return true; | |
726 | ||
727 | /* | |
728 | * We can't run Idle Load Balance on this CPU for this time so we | |
729 | * cancel it and clear NOHZ_BALANCE_KICK | |
730 | */ | |
731 | clear_bit(NOHZ_BALANCE_KICK, nohz_flags(cpu)); | |
732 | return false; | |
45bf76df IM |
733 | } |
734 | ||
3451d024 | 735 | #else /* CONFIG_NO_HZ_COMMON */ |
45bf76df | 736 | |
ca38062e | 737 | static inline bool got_nohz_idle_kick(void) |
2069dd75 | 738 | { |
ca38062e | 739 | return false; |
2069dd75 PZ |
740 | } |
741 | ||
3451d024 | 742 | #endif /* CONFIG_NO_HZ_COMMON */ |
d842de87 | 743 | |
ce831b38 FW |
744 | #ifdef CONFIG_NO_HZ_FULL |
745 | bool sched_can_stop_tick(void) | |
746 | { | |
3882ec64 FW |
747 | /* |
748 | * More than one running task need preemption. | |
749 | * nr_running update is assumed to be visible | |
750 | * after IPI is sent from wakers. | |
751 | */ | |
541b8264 VK |
752 | if (this_rq()->nr_running > 1) |
753 | return false; | |
ce831b38 | 754 | |
541b8264 | 755 | return true; |
ce831b38 FW |
756 | } |
757 | #endif /* CONFIG_NO_HZ_FULL */ | |
d842de87 | 758 | |
029632fb | 759 | void sched_avg_update(struct rq *rq) |
18d95a28 | 760 | { |
e9e9250b PZ |
761 | s64 period = sched_avg_period(); |
762 | ||
78becc27 | 763 | while ((s64)(rq_clock(rq) - rq->age_stamp) > period) { |
0d98bb26 WD |
764 | /* |
765 | * Inline assembly required to prevent the compiler | |
766 | * optimising this loop into a divmod call. | |
767 | * See __iter_div_u64_rem() for another example of this. | |
768 | */ | |
769 | asm("" : "+rm" (rq->age_stamp)); | |
e9e9250b PZ |
770 | rq->age_stamp += period; |
771 | rq->rt_avg /= 2; | |
772 | } | |
18d95a28 PZ |
773 | } |
774 | ||
6d6bc0ad | 775 | #endif /* CONFIG_SMP */ |
18d95a28 | 776 | |
a790de99 PT |
777 | #if defined(CONFIG_RT_GROUP_SCHED) || (defined(CONFIG_FAIR_GROUP_SCHED) && \ |
778 | (defined(CONFIG_SMP) || defined(CONFIG_CFS_BANDWIDTH))) | |
c09595f6 | 779 | /* |
8277434e PT |
780 | * Iterate task_group tree rooted at *from, calling @down when first entering a |
781 | * node and @up when leaving it for the final time. | |
782 | * | |
783 | * Caller must hold rcu_lock or sufficient equivalent. | |
c09595f6 | 784 | */ |
029632fb | 785 | int walk_tg_tree_from(struct task_group *from, |
8277434e | 786 | tg_visitor down, tg_visitor up, void *data) |
c09595f6 PZ |
787 | { |
788 | struct task_group *parent, *child; | |
eb755805 | 789 | int ret; |
c09595f6 | 790 | |
8277434e PT |
791 | parent = from; |
792 | ||
c09595f6 | 793 | down: |
eb755805 PZ |
794 | ret = (*down)(parent, data); |
795 | if (ret) | |
8277434e | 796 | goto out; |
c09595f6 PZ |
797 | list_for_each_entry_rcu(child, &parent->children, siblings) { |
798 | parent = child; | |
799 | goto down; | |
800 | ||
801 | up: | |
802 | continue; | |
803 | } | |
eb755805 | 804 | ret = (*up)(parent, data); |
8277434e PT |
805 | if (ret || parent == from) |
806 | goto out; | |
c09595f6 PZ |
807 | |
808 | child = parent; | |
809 | parent = parent->parent; | |
810 | if (parent) | |
811 | goto up; | |
8277434e | 812 | out: |
eb755805 | 813 | return ret; |
c09595f6 PZ |
814 | } |
815 | ||
029632fb | 816 | int tg_nop(struct task_group *tg, void *data) |
eb755805 | 817 | { |
e2b245f8 | 818 | return 0; |
eb755805 | 819 | } |
18d95a28 PZ |
820 | #endif |
821 | ||
45bf76df IM |
822 | static void set_load_weight(struct task_struct *p) |
823 | { | |
f05998d4 NR |
824 | int prio = p->static_prio - MAX_RT_PRIO; |
825 | struct load_weight *load = &p->se.load; | |
826 | ||
dd41f596 IM |
827 | /* |
828 | * SCHED_IDLE tasks get minimal weight: | |
829 | */ | |
830 | if (p->policy == SCHED_IDLE) { | |
c8b28116 | 831 | load->weight = scale_load(WEIGHT_IDLEPRIO); |
f05998d4 | 832 | load->inv_weight = WMULT_IDLEPRIO; |
dd41f596 IM |
833 | return; |
834 | } | |
71f8bd46 | 835 | |
c8b28116 | 836 | load->weight = scale_load(prio_to_weight[prio]); |
f05998d4 | 837 | load->inv_weight = prio_to_wmult[prio]; |
71f8bd46 IM |
838 | } |
839 | ||
371fd7e7 | 840 | static void enqueue_task(struct rq *rq, struct task_struct *p, int flags) |
2087a1ad | 841 | { |
a64692a3 | 842 | update_rq_clock(rq); |
43148951 | 843 | sched_info_queued(rq, p); |
371fd7e7 | 844 | p->sched_class->enqueue_task(rq, p, flags); |
71f8bd46 IM |
845 | } |
846 | ||
371fd7e7 | 847 | static void dequeue_task(struct rq *rq, struct task_struct *p, int flags) |
71f8bd46 | 848 | { |
a64692a3 | 849 | update_rq_clock(rq); |
43148951 | 850 | sched_info_dequeued(rq, p); |
371fd7e7 | 851 | p->sched_class->dequeue_task(rq, p, flags); |
71f8bd46 IM |
852 | } |
853 | ||
029632fb | 854 | void activate_task(struct rq *rq, struct task_struct *p, int flags) |
1e3c88bd PZ |
855 | { |
856 | if (task_contributes_to_load(p)) | |
857 | rq->nr_uninterruptible--; | |
858 | ||
371fd7e7 | 859 | enqueue_task(rq, p, flags); |
1e3c88bd PZ |
860 | } |
861 | ||
029632fb | 862 | void deactivate_task(struct rq *rq, struct task_struct *p, int flags) |
1e3c88bd PZ |
863 | { |
864 | if (task_contributes_to_load(p)) | |
865 | rq->nr_uninterruptible++; | |
866 | ||
371fd7e7 | 867 | dequeue_task(rq, p, flags); |
1e3c88bd PZ |
868 | } |
869 | ||
fe44d621 | 870 | static void update_rq_clock_task(struct rq *rq, s64 delta) |
aa483808 | 871 | { |
095c0aa8 GC |
872 | /* |
873 | * In theory, the compile should just see 0 here, and optimize out the call | |
874 | * to sched_rt_avg_update. But I don't trust it... | |
875 | */ | |
876 | #if defined(CONFIG_IRQ_TIME_ACCOUNTING) || defined(CONFIG_PARAVIRT_TIME_ACCOUNTING) | |
877 | s64 steal = 0, irq_delta = 0; | |
878 | #endif | |
879 | #ifdef CONFIG_IRQ_TIME_ACCOUNTING | |
8e92c201 | 880 | irq_delta = irq_time_read(cpu_of(rq)) - rq->prev_irq_time; |
fe44d621 PZ |
881 | |
882 | /* | |
883 | * Since irq_time is only updated on {soft,}irq_exit, we might run into | |
884 | * this case when a previous update_rq_clock() happened inside a | |
885 | * {soft,}irq region. | |
886 | * | |
887 | * When this happens, we stop ->clock_task and only update the | |
888 | * prev_irq_time stamp to account for the part that fit, so that a next | |
889 | * update will consume the rest. This ensures ->clock_task is | |
890 | * monotonic. | |
891 | * | |
892 | * It does however cause some slight miss-attribution of {soft,}irq | |
893 | * time, a more accurate solution would be to update the irq_time using | |
894 | * the current rq->clock timestamp, except that would require using | |
895 | * atomic ops. | |
896 | */ | |
897 | if (irq_delta > delta) | |
898 | irq_delta = delta; | |
899 | ||
900 | rq->prev_irq_time += irq_delta; | |
901 | delta -= irq_delta; | |
095c0aa8 GC |
902 | #endif |
903 | #ifdef CONFIG_PARAVIRT_TIME_ACCOUNTING | |
c5905afb | 904 | if (static_key_false((¶virt_steal_rq_enabled))) { |
095c0aa8 GC |
905 | steal = paravirt_steal_clock(cpu_of(rq)); |
906 | steal -= rq->prev_steal_time_rq; | |
907 | ||
908 | if (unlikely(steal > delta)) | |
909 | steal = delta; | |
910 | ||
095c0aa8 | 911 | rq->prev_steal_time_rq += steal; |
095c0aa8 GC |
912 | delta -= steal; |
913 | } | |
914 | #endif | |
915 | ||
fe44d621 PZ |
916 | rq->clock_task += delta; |
917 | ||
095c0aa8 | 918 | #if defined(CONFIG_IRQ_TIME_ACCOUNTING) || defined(CONFIG_PARAVIRT_TIME_ACCOUNTING) |
5d4dfddd | 919 | if ((irq_delta + steal) && sched_feat(NONTASK_CAPACITY)) |
095c0aa8 GC |
920 | sched_rt_avg_update(rq, irq_delta + steal); |
921 | #endif | |
aa483808 VP |
922 | } |
923 | ||
34f971f6 PZ |
924 | void sched_set_stop_task(int cpu, struct task_struct *stop) |
925 | { | |
926 | struct sched_param param = { .sched_priority = MAX_RT_PRIO - 1 }; | |
927 | struct task_struct *old_stop = cpu_rq(cpu)->stop; | |
928 | ||
929 | if (stop) { | |
930 | /* | |
931 | * Make it appear like a SCHED_FIFO task, its something | |
932 | * userspace knows about and won't get confused about. | |
933 | * | |
934 | * Also, it will make PI more or less work without too | |
935 | * much confusion -- but then, stop work should not | |
936 | * rely on PI working anyway. | |
937 | */ | |
938 | sched_setscheduler_nocheck(stop, SCHED_FIFO, ¶m); | |
939 | ||
940 | stop->sched_class = &stop_sched_class; | |
941 | } | |
942 | ||
943 | cpu_rq(cpu)->stop = stop; | |
944 | ||
945 | if (old_stop) { | |
946 | /* | |
947 | * Reset it back to a normal scheduling class so that | |
948 | * it can die in pieces. | |
949 | */ | |
950 | old_stop->sched_class = &rt_sched_class; | |
951 | } | |
952 | } | |
953 | ||
14531189 | 954 | /* |
dd41f596 | 955 | * __normal_prio - return the priority that is based on the static prio |
14531189 | 956 | */ |
14531189 IM |
957 | static inline int __normal_prio(struct task_struct *p) |
958 | { | |
dd41f596 | 959 | return p->static_prio; |
14531189 IM |
960 | } |
961 | ||
b29739f9 IM |
962 | /* |
963 | * Calculate the expected normal priority: i.e. priority | |
964 | * without taking RT-inheritance into account. Might be | |
965 | * boosted by interactivity modifiers. Changes upon fork, | |
966 | * setprio syscalls, and whenever the interactivity | |
967 | * estimator recalculates. | |
968 | */ | |
36c8b586 | 969 | static inline int normal_prio(struct task_struct *p) |
b29739f9 IM |
970 | { |
971 | int prio; | |
972 | ||
aab03e05 DF |
973 | if (task_has_dl_policy(p)) |
974 | prio = MAX_DL_PRIO-1; | |
975 | else if (task_has_rt_policy(p)) | |
b29739f9 IM |
976 | prio = MAX_RT_PRIO-1 - p->rt_priority; |
977 | else | |
978 | prio = __normal_prio(p); | |
979 | return prio; | |
980 | } | |
981 | ||
982 | /* | |
983 | * Calculate the current priority, i.e. the priority | |
984 | * taken into account by the scheduler. This value might | |
985 | * be boosted by RT tasks, or might be boosted by | |
986 | * interactivity modifiers. Will be RT if the task got | |
987 | * RT-boosted. If not then it returns p->normal_prio. | |
988 | */ | |
36c8b586 | 989 | static int effective_prio(struct task_struct *p) |
b29739f9 IM |
990 | { |
991 | p->normal_prio = normal_prio(p); | |
992 | /* | |
993 | * If we are RT tasks or we were boosted to RT priority, | |
994 | * keep the priority unchanged. Otherwise, update priority | |
995 | * to the normal priority: | |
996 | */ | |
997 | if (!rt_prio(p->prio)) | |
998 | return p->normal_prio; | |
999 | return p->prio; | |
1000 | } | |
1001 | ||
1da177e4 LT |
1002 | /** |
1003 | * task_curr - is this task currently executing on a CPU? | |
1004 | * @p: the task in question. | |
e69f6186 YB |
1005 | * |
1006 | * Return: 1 if the task is currently executing. 0 otherwise. | |
1da177e4 | 1007 | */ |
36c8b586 | 1008 | inline int task_curr(const struct task_struct *p) |
1da177e4 LT |
1009 | { |
1010 | return cpu_curr(task_cpu(p)) == p; | |
1011 | } | |
1012 | ||
67dfa1b7 KT |
1013 | /* |
1014 | * Can drop rq->lock because from sched_class::switched_from() methods drop it. | |
1015 | */ | |
cb469845 SR |
1016 | static inline void check_class_changed(struct rq *rq, struct task_struct *p, |
1017 | const struct sched_class *prev_class, | |
da7a735e | 1018 | int oldprio) |
cb469845 SR |
1019 | { |
1020 | if (prev_class != p->sched_class) { | |
1021 | if (prev_class->switched_from) | |
da7a735e | 1022 | prev_class->switched_from(rq, p); |
67dfa1b7 | 1023 | /* Possble rq->lock 'hole'. */ |
da7a735e | 1024 | p->sched_class->switched_to(rq, p); |
2d3d891d | 1025 | } else if (oldprio != p->prio || dl_task(p)) |
da7a735e | 1026 | p->sched_class->prio_changed(rq, p, oldprio); |
cb469845 SR |
1027 | } |
1028 | ||
029632fb | 1029 | void check_preempt_curr(struct rq *rq, struct task_struct *p, int flags) |
1e5a7405 PZ |
1030 | { |
1031 | const struct sched_class *class; | |
1032 | ||
1033 | if (p->sched_class == rq->curr->sched_class) { | |
1034 | rq->curr->sched_class->check_preempt_curr(rq, p, flags); | |
1035 | } else { | |
1036 | for_each_class(class) { | |
1037 | if (class == rq->curr->sched_class) | |
1038 | break; | |
1039 | if (class == p->sched_class) { | |
8875125e | 1040 | resched_curr(rq); |
1e5a7405 PZ |
1041 | break; |
1042 | } | |
1043 | } | |
1044 | } | |
1045 | ||
1046 | /* | |
1047 | * A queue event has occurred, and we're going to schedule. In | |
1048 | * this case, we can save a useless back to back clock update. | |
1049 | */ | |
da0c1e65 | 1050 | if (task_on_rq_queued(rq->curr) && test_tsk_need_resched(rq->curr)) |
9edfbfed | 1051 | rq_clock_skip_update(rq, true); |
1e5a7405 PZ |
1052 | } |
1053 | ||
1da177e4 | 1054 | #ifdef CONFIG_SMP |
dd41f596 | 1055 | void set_task_cpu(struct task_struct *p, unsigned int new_cpu) |
c65cc870 | 1056 | { |
e2912009 PZ |
1057 | #ifdef CONFIG_SCHED_DEBUG |
1058 | /* | |
1059 | * We should never call set_task_cpu() on a blocked task, | |
1060 | * ttwu() will sort out the placement. | |
1061 | */ | |
077614ee | 1062 | WARN_ON_ONCE(p->state != TASK_RUNNING && p->state != TASK_WAKING && |
e2336f6e | 1063 | !p->on_rq); |
0122ec5b PZ |
1064 | |
1065 | #ifdef CONFIG_LOCKDEP | |
6c6c54e1 PZ |
1066 | /* |
1067 | * The caller should hold either p->pi_lock or rq->lock, when changing | |
1068 | * a task's CPU. ->pi_lock for waking tasks, rq->lock for runnable tasks. | |
1069 | * | |
1070 | * sched_move_task() holds both and thus holding either pins the cgroup, | |
8323f26c | 1071 | * see task_group(). |
6c6c54e1 PZ |
1072 | * |
1073 | * Furthermore, all task_rq users should acquire both locks, see | |
1074 | * task_rq_lock(). | |
1075 | */ | |
0122ec5b PZ |
1076 | WARN_ON_ONCE(debug_locks && !(lockdep_is_held(&p->pi_lock) || |
1077 | lockdep_is_held(&task_rq(p)->lock))); | |
1078 | #endif | |
e2912009 PZ |
1079 | #endif |
1080 | ||
de1d7286 | 1081 | trace_sched_migrate_task(p, new_cpu); |
cbc34ed1 | 1082 | |
0c69774e | 1083 | if (task_cpu(p) != new_cpu) { |
0a74bef8 PT |
1084 | if (p->sched_class->migrate_task_rq) |
1085 | p->sched_class->migrate_task_rq(p, new_cpu); | |
0c69774e | 1086 | p->se.nr_migrations++; |
a8b0ca17 | 1087 | perf_sw_event(PERF_COUNT_SW_CPU_MIGRATIONS, 1, NULL, 0); |
0c69774e | 1088 | } |
dd41f596 IM |
1089 | |
1090 | __set_task_cpu(p, new_cpu); | |
c65cc870 IM |
1091 | } |
1092 | ||
ac66f547 PZ |
1093 | static void __migrate_swap_task(struct task_struct *p, int cpu) |
1094 | { | |
da0c1e65 | 1095 | if (task_on_rq_queued(p)) { |
ac66f547 PZ |
1096 | struct rq *src_rq, *dst_rq; |
1097 | ||
1098 | src_rq = task_rq(p); | |
1099 | dst_rq = cpu_rq(cpu); | |
1100 | ||
1101 | deactivate_task(src_rq, p, 0); | |
1102 | set_task_cpu(p, cpu); | |
1103 | activate_task(dst_rq, p, 0); | |
1104 | check_preempt_curr(dst_rq, p, 0); | |
1105 | } else { | |
1106 | /* | |
1107 | * Task isn't running anymore; make it appear like we migrated | |
1108 | * it before it went to sleep. This means on wakeup we make the | |
1109 | * previous cpu our targer instead of where it really is. | |
1110 | */ | |
1111 | p->wake_cpu = cpu; | |
1112 | } | |
1113 | } | |
1114 | ||
1115 | struct migration_swap_arg { | |
1116 | struct task_struct *src_task, *dst_task; | |
1117 | int src_cpu, dst_cpu; | |
1118 | }; | |
1119 | ||
1120 | static int migrate_swap_stop(void *data) | |
1121 | { | |
1122 | struct migration_swap_arg *arg = data; | |
1123 | struct rq *src_rq, *dst_rq; | |
1124 | int ret = -EAGAIN; | |
1125 | ||
1126 | src_rq = cpu_rq(arg->src_cpu); | |
1127 | dst_rq = cpu_rq(arg->dst_cpu); | |
1128 | ||
74602315 PZ |
1129 | double_raw_lock(&arg->src_task->pi_lock, |
1130 | &arg->dst_task->pi_lock); | |
ac66f547 PZ |
1131 | double_rq_lock(src_rq, dst_rq); |
1132 | if (task_cpu(arg->dst_task) != arg->dst_cpu) | |
1133 | goto unlock; | |
1134 | ||
1135 | if (task_cpu(arg->src_task) != arg->src_cpu) | |
1136 | goto unlock; | |
1137 | ||
1138 | if (!cpumask_test_cpu(arg->dst_cpu, tsk_cpus_allowed(arg->src_task))) | |
1139 | goto unlock; | |
1140 | ||
1141 | if (!cpumask_test_cpu(arg->src_cpu, tsk_cpus_allowed(arg->dst_task))) | |
1142 | goto unlock; | |
1143 | ||
1144 | __migrate_swap_task(arg->src_task, arg->dst_cpu); | |
1145 | __migrate_swap_task(arg->dst_task, arg->src_cpu); | |
1146 | ||
1147 | ret = 0; | |
1148 | ||
1149 | unlock: | |
1150 | double_rq_unlock(src_rq, dst_rq); | |
74602315 PZ |
1151 | raw_spin_unlock(&arg->dst_task->pi_lock); |
1152 | raw_spin_unlock(&arg->src_task->pi_lock); | |
ac66f547 PZ |
1153 | |
1154 | return ret; | |
1155 | } | |
1156 | ||
1157 | /* | |
1158 | * Cross migrate two tasks | |
1159 | */ | |
1160 | int migrate_swap(struct task_struct *cur, struct task_struct *p) | |
1161 | { | |
1162 | struct migration_swap_arg arg; | |
1163 | int ret = -EINVAL; | |
1164 | ||
ac66f547 PZ |
1165 | arg = (struct migration_swap_arg){ |
1166 | .src_task = cur, | |
1167 | .src_cpu = task_cpu(cur), | |
1168 | .dst_task = p, | |
1169 | .dst_cpu = task_cpu(p), | |
1170 | }; | |
1171 | ||
1172 | if (arg.src_cpu == arg.dst_cpu) | |
1173 | goto out; | |
1174 | ||
6acce3ef PZ |
1175 | /* |
1176 | * These three tests are all lockless; this is OK since all of them | |
1177 | * will be re-checked with proper locks held further down the line. | |
1178 | */ | |
ac66f547 PZ |
1179 | if (!cpu_active(arg.src_cpu) || !cpu_active(arg.dst_cpu)) |
1180 | goto out; | |
1181 | ||
1182 | if (!cpumask_test_cpu(arg.dst_cpu, tsk_cpus_allowed(arg.src_task))) | |
1183 | goto out; | |
1184 | ||
1185 | if (!cpumask_test_cpu(arg.src_cpu, tsk_cpus_allowed(arg.dst_task))) | |
1186 | goto out; | |
1187 | ||
286549dc | 1188 | trace_sched_swap_numa(cur, arg.src_cpu, p, arg.dst_cpu); |
ac66f547 PZ |
1189 | ret = stop_two_cpus(arg.dst_cpu, arg.src_cpu, migrate_swap_stop, &arg); |
1190 | ||
1191 | out: | |
ac66f547 PZ |
1192 | return ret; |
1193 | } | |
1194 | ||
969c7921 | 1195 | struct migration_arg { |
36c8b586 | 1196 | struct task_struct *task; |
1da177e4 | 1197 | int dest_cpu; |
70b97a7f | 1198 | }; |
1da177e4 | 1199 | |
969c7921 TH |
1200 | static int migration_cpu_stop(void *data); |
1201 | ||
1da177e4 LT |
1202 | /* |
1203 | * wait_task_inactive - wait for a thread to unschedule. | |
1204 | * | |
85ba2d86 RM |
1205 | * If @match_state is nonzero, it's the @p->state value just checked and |
1206 | * not expected to change. If it changes, i.e. @p might have woken up, | |
1207 | * then return zero. When we succeed in waiting for @p to be off its CPU, | |
1208 | * we return a positive number (its total switch count). If a second call | |
1209 | * a short while later returns the same number, the caller can be sure that | |
1210 | * @p has remained unscheduled the whole time. | |
1211 | * | |
1da177e4 LT |
1212 | * The caller must ensure that the task *will* unschedule sometime soon, |
1213 | * else this function might spin for a *long* time. This function can't | |
1214 | * be called with interrupts off, or it may introduce deadlock with | |
1215 | * smp_call_function() if an IPI is sent by the same process we are | |
1216 | * waiting to become inactive. | |
1217 | */ | |
85ba2d86 | 1218 | unsigned long wait_task_inactive(struct task_struct *p, long match_state) |
1da177e4 LT |
1219 | { |
1220 | unsigned long flags; | |
da0c1e65 | 1221 | int running, queued; |
85ba2d86 | 1222 | unsigned long ncsw; |
70b97a7f | 1223 | struct rq *rq; |
1da177e4 | 1224 | |
3a5c359a AK |
1225 | for (;;) { |
1226 | /* | |
1227 | * We do the initial early heuristics without holding | |
1228 | * any task-queue locks at all. We'll only try to get | |
1229 | * the runqueue lock when things look like they will | |
1230 | * work out! | |
1231 | */ | |
1232 | rq = task_rq(p); | |
fa490cfd | 1233 | |
3a5c359a AK |
1234 | /* |
1235 | * If the task is actively running on another CPU | |
1236 | * still, just relax and busy-wait without holding | |
1237 | * any locks. | |
1238 | * | |
1239 | * NOTE! Since we don't hold any locks, it's not | |
1240 | * even sure that "rq" stays as the right runqueue! | |
1241 | * But we don't care, since "task_running()" will | |
1242 | * return false if the runqueue has changed and p | |
1243 | * is actually now running somewhere else! | |
1244 | */ | |
85ba2d86 RM |
1245 | while (task_running(rq, p)) { |
1246 | if (match_state && unlikely(p->state != match_state)) | |
1247 | return 0; | |
3a5c359a | 1248 | cpu_relax(); |
85ba2d86 | 1249 | } |
fa490cfd | 1250 | |
3a5c359a AK |
1251 | /* |
1252 | * Ok, time to look more closely! We need the rq | |
1253 | * lock now, to be *sure*. If we're wrong, we'll | |
1254 | * just go back and repeat. | |
1255 | */ | |
1256 | rq = task_rq_lock(p, &flags); | |
27a9da65 | 1257 | trace_sched_wait_task(p); |
3a5c359a | 1258 | running = task_running(rq, p); |
da0c1e65 | 1259 | queued = task_on_rq_queued(p); |
85ba2d86 | 1260 | ncsw = 0; |
f31e11d8 | 1261 | if (!match_state || p->state == match_state) |
93dcf55f | 1262 | ncsw = p->nvcsw | LONG_MIN; /* sets MSB */ |
0122ec5b | 1263 | task_rq_unlock(rq, p, &flags); |
fa490cfd | 1264 | |
85ba2d86 RM |
1265 | /* |
1266 | * If it changed from the expected state, bail out now. | |
1267 | */ | |
1268 | if (unlikely(!ncsw)) | |
1269 | break; | |
1270 | ||
3a5c359a AK |
1271 | /* |
1272 | * Was it really running after all now that we | |
1273 | * checked with the proper locks actually held? | |
1274 | * | |
1275 | * Oops. Go back and try again.. | |
1276 | */ | |
1277 | if (unlikely(running)) { | |
1278 | cpu_relax(); | |
1279 | continue; | |
1280 | } | |
fa490cfd | 1281 | |
3a5c359a AK |
1282 | /* |
1283 | * It's not enough that it's not actively running, | |
1284 | * it must be off the runqueue _entirely_, and not | |
1285 | * preempted! | |
1286 | * | |
80dd99b3 | 1287 | * So if it was still runnable (but just not actively |
3a5c359a AK |
1288 | * running right now), it's preempted, and we should |
1289 | * yield - it could be a while. | |
1290 | */ | |
da0c1e65 | 1291 | if (unlikely(queued)) { |
8eb90c30 TG |
1292 | ktime_t to = ktime_set(0, NSEC_PER_SEC/HZ); |
1293 | ||
1294 | set_current_state(TASK_UNINTERRUPTIBLE); | |
1295 | schedule_hrtimeout(&to, HRTIMER_MODE_REL); | |
3a5c359a AK |
1296 | continue; |
1297 | } | |
fa490cfd | 1298 | |
3a5c359a AK |
1299 | /* |
1300 | * Ahh, all good. It wasn't running, and it wasn't | |
1301 | * runnable, which means that it will never become | |
1302 | * running in the future either. We're all done! | |
1303 | */ | |
1304 | break; | |
1305 | } | |
85ba2d86 RM |
1306 | |
1307 | return ncsw; | |
1da177e4 LT |
1308 | } |
1309 | ||
1310 | /*** | |
1311 | * kick_process - kick a running thread to enter/exit the kernel | |
1312 | * @p: the to-be-kicked thread | |
1313 | * | |
1314 | * Cause a process which is running on another CPU to enter | |
1315 | * kernel-mode, without any delay. (to get signals handled.) | |
1316 | * | |
25985edc | 1317 | * NOTE: this function doesn't have to take the runqueue lock, |
1da177e4 LT |
1318 | * because all it wants to ensure is that the remote task enters |
1319 | * the kernel. If the IPI races and the task has been migrated | |
1320 | * to another CPU then no harm is done and the purpose has been | |
1321 | * achieved as well. | |
1322 | */ | |
36c8b586 | 1323 | void kick_process(struct task_struct *p) |
1da177e4 LT |
1324 | { |
1325 | int cpu; | |
1326 | ||
1327 | preempt_disable(); | |
1328 | cpu = task_cpu(p); | |
1329 | if ((cpu != smp_processor_id()) && task_curr(p)) | |
1330 | smp_send_reschedule(cpu); | |
1331 | preempt_enable(); | |
1332 | } | |
b43e3521 | 1333 | EXPORT_SYMBOL_GPL(kick_process); |
476d139c | 1334 | #endif /* CONFIG_SMP */ |
1da177e4 | 1335 | |
970b13ba | 1336 | #ifdef CONFIG_SMP |
30da688e | 1337 | /* |
013fdb80 | 1338 | * ->cpus_allowed is protected by both rq->lock and p->pi_lock |
30da688e | 1339 | */ |
5da9a0fb PZ |
1340 | static int select_fallback_rq(int cpu, struct task_struct *p) |
1341 | { | |
aa00d89c TC |
1342 | int nid = cpu_to_node(cpu); |
1343 | const struct cpumask *nodemask = NULL; | |
2baab4e9 PZ |
1344 | enum { cpuset, possible, fail } state = cpuset; |
1345 | int dest_cpu; | |
5da9a0fb | 1346 | |
aa00d89c TC |
1347 | /* |
1348 | * If the node that the cpu is on has been offlined, cpu_to_node() | |
1349 | * will return -1. There is no cpu on the node, and we should | |
1350 | * select the cpu on the other node. | |
1351 | */ | |
1352 | if (nid != -1) { | |
1353 | nodemask = cpumask_of_node(nid); | |
1354 | ||
1355 | /* Look for allowed, online CPU in same node. */ | |
1356 | for_each_cpu(dest_cpu, nodemask) { | |
1357 | if (!cpu_online(dest_cpu)) | |
1358 | continue; | |
1359 | if (!cpu_active(dest_cpu)) | |
1360 | continue; | |
1361 | if (cpumask_test_cpu(dest_cpu, tsk_cpus_allowed(p))) | |
1362 | return dest_cpu; | |
1363 | } | |
2baab4e9 | 1364 | } |
5da9a0fb | 1365 | |
2baab4e9 PZ |
1366 | for (;;) { |
1367 | /* Any allowed, online CPU? */ | |
e3831edd | 1368 | for_each_cpu(dest_cpu, tsk_cpus_allowed(p)) { |
2baab4e9 PZ |
1369 | if (!cpu_online(dest_cpu)) |
1370 | continue; | |
1371 | if (!cpu_active(dest_cpu)) | |
1372 | continue; | |
1373 | goto out; | |
1374 | } | |
5da9a0fb | 1375 | |
2baab4e9 PZ |
1376 | switch (state) { |
1377 | case cpuset: | |
1378 | /* No more Mr. Nice Guy. */ | |
1379 | cpuset_cpus_allowed_fallback(p); | |
1380 | state = possible; | |
1381 | break; | |
1382 | ||
1383 | case possible: | |
1384 | do_set_cpus_allowed(p, cpu_possible_mask); | |
1385 | state = fail; | |
1386 | break; | |
1387 | ||
1388 | case fail: | |
1389 | BUG(); | |
1390 | break; | |
1391 | } | |
1392 | } | |
1393 | ||
1394 | out: | |
1395 | if (state != cpuset) { | |
1396 | /* | |
1397 | * Don't tell them about moving exiting tasks or | |
1398 | * kernel threads (both mm NULL), since they never | |
1399 | * leave kernel. | |
1400 | */ | |
1401 | if (p->mm && printk_ratelimit()) { | |
aac74dc4 | 1402 | printk_deferred("process %d (%s) no longer affine to cpu%d\n", |
2baab4e9 PZ |
1403 | task_pid_nr(p), p->comm, cpu); |
1404 | } | |
5da9a0fb PZ |
1405 | } |
1406 | ||
1407 | return dest_cpu; | |
1408 | } | |
1409 | ||
e2912009 | 1410 | /* |
013fdb80 | 1411 | * The caller (fork, wakeup) owns p->pi_lock, ->cpus_allowed is stable. |
e2912009 | 1412 | */ |
970b13ba | 1413 | static inline |
ac66f547 | 1414 | int select_task_rq(struct task_struct *p, int cpu, int sd_flags, int wake_flags) |
970b13ba | 1415 | { |
6c1d9410 WL |
1416 | if (p->nr_cpus_allowed > 1) |
1417 | cpu = p->sched_class->select_task_rq(p, cpu, sd_flags, wake_flags); | |
e2912009 PZ |
1418 | |
1419 | /* | |
1420 | * In order not to call set_task_cpu() on a blocking task we need | |
1421 | * to rely on ttwu() to place the task on a valid ->cpus_allowed | |
1422 | * cpu. | |
1423 | * | |
1424 | * Since this is common to all placement strategies, this lives here. | |
1425 | * | |
1426 | * [ this allows ->select_task() to simply return task_cpu(p) and | |
1427 | * not worry about this generic constraint ] | |
1428 | */ | |
fa17b507 | 1429 | if (unlikely(!cpumask_test_cpu(cpu, tsk_cpus_allowed(p)) || |
70f11205 | 1430 | !cpu_online(cpu))) |
5da9a0fb | 1431 | cpu = select_fallback_rq(task_cpu(p), p); |
e2912009 PZ |
1432 | |
1433 | return cpu; | |
970b13ba | 1434 | } |
09a40af5 MG |
1435 | |
1436 | static void update_avg(u64 *avg, u64 sample) | |
1437 | { | |
1438 | s64 diff = sample - *avg; | |
1439 | *avg += diff >> 3; | |
1440 | } | |
970b13ba PZ |
1441 | #endif |
1442 | ||
d7c01d27 | 1443 | static void |
b84cb5df | 1444 | ttwu_stat(struct task_struct *p, int cpu, int wake_flags) |
9ed3811a | 1445 | { |
d7c01d27 | 1446 | #ifdef CONFIG_SCHEDSTATS |
b84cb5df PZ |
1447 | struct rq *rq = this_rq(); |
1448 | ||
d7c01d27 PZ |
1449 | #ifdef CONFIG_SMP |
1450 | int this_cpu = smp_processor_id(); | |
1451 | ||
1452 | if (cpu == this_cpu) { | |
1453 | schedstat_inc(rq, ttwu_local); | |
1454 | schedstat_inc(p, se.statistics.nr_wakeups_local); | |
1455 | } else { | |
1456 | struct sched_domain *sd; | |
1457 | ||
1458 | schedstat_inc(p, se.statistics.nr_wakeups_remote); | |
057f3fad | 1459 | rcu_read_lock(); |
d7c01d27 PZ |
1460 | for_each_domain(this_cpu, sd) { |
1461 | if (cpumask_test_cpu(cpu, sched_domain_span(sd))) { | |
1462 | schedstat_inc(sd, ttwu_wake_remote); | |
1463 | break; | |
1464 | } | |
1465 | } | |
057f3fad | 1466 | rcu_read_unlock(); |
d7c01d27 | 1467 | } |
f339b9dc PZ |
1468 | |
1469 | if (wake_flags & WF_MIGRATED) | |
1470 | schedstat_inc(p, se.statistics.nr_wakeups_migrate); | |
1471 | ||
d7c01d27 PZ |
1472 | #endif /* CONFIG_SMP */ |
1473 | ||
1474 | schedstat_inc(rq, ttwu_count); | |
9ed3811a | 1475 | schedstat_inc(p, se.statistics.nr_wakeups); |
d7c01d27 PZ |
1476 | |
1477 | if (wake_flags & WF_SYNC) | |
9ed3811a | 1478 | schedstat_inc(p, se.statistics.nr_wakeups_sync); |
d7c01d27 | 1479 | |
d7c01d27 PZ |
1480 | #endif /* CONFIG_SCHEDSTATS */ |
1481 | } | |
1482 | ||
1483 | static void ttwu_activate(struct rq *rq, struct task_struct *p, int en_flags) | |
1484 | { | |
9ed3811a | 1485 | activate_task(rq, p, en_flags); |
da0c1e65 | 1486 | p->on_rq = TASK_ON_RQ_QUEUED; |
c2f7115e PZ |
1487 | |
1488 | /* if a worker is waking up, notify workqueue */ | |
1489 | if (p->flags & PF_WQ_WORKER) | |
1490 | wq_worker_waking_up(p, cpu_of(rq)); | |
9ed3811a TH |
1491 | } |
1492 | ||
23f41eeb PZ |
1493 | /* |
1494 | * Mark the task runnable and perform wakeup-preemption. | |
1495 | */ | |
89363381 | 1496 | static void |
23f41eeb | 1497 | ttwu_do_wakeup(struct rq *rq, struct task_struct *p, int wake_flags) |
9ed3811a | 1498 | { |
9ed3811a | 1499 | check_preempt_curr(rq, p, wake_flags); |
a8d7ad52 | 1500 | trace_sched_wakeup(p, true); |
9ed3811a TH |
1501 | |
1502 | p->state = TASK_RUNNING; | |
1503 | #ifdef CONFIG_SMP | |
1504 | if (p->sched_class->task_woken) | |
1505 | p->sched_class->task_woken(rq, p); | |
1506 | ||
e69c6341 | 1507 | if (rq->idle_stamp) { |
78becc27 | 1508 | u64 delta = rq_clock(rq) - rq->idle_stamp; |
9bd721c5 | 1509 | u64 max = 2*rq->max_idle_balance_cost; |
9ed3811a | 1510 | |
abfafa54 JL |
1511 | update_avg(&rq->avg_idle, delta); |
1512 | ||
1513 | if (rq->avg_idle > max) | |
9ed3811a | 1514 | rq->avg_idle = max; |
abfafa54 | 1515 | |
9ed3811a TH |
1516 | rq->idle_stamp = 0; |
1517 | } | |
1518 | #endif | |
1519 | } | |
1520 | ||
c05fbafb PZ |
1521 | static void |
1522 | ttwu_do_activate(struct rq *rq, struct task_struct *p, int wake_flags) | |
1523 | { | |
1524 | #ifdef CONFIG_SMP | |
1525 | if (p->sched_contributes_to_load) | |
1526 | rq->nr_uninterruptible--; | |
1527 | #endif | |
1528 | ||
1529 | ttwu_activate(rq, p, ENQUEUE_WAKEUP | ENQUEUE_WAKING); | |
1530 | ttwu_do_wakeup(rq, p, wake_flags); | |
1531 | } | |
1532 | ||
1533 | /* | |
1534 | * Called in case the task @p isn't fully descheduled from its runqueue, | |
1535 | * in this case we must do a remote wakeup. Its a 'light' wakeup though, | |
1536 | * since all we need to do is flip p->state to TASK_RUNNING, since | |
1537 | * the task is still ->on_rq. | |
1538 | */ | |
1539 | static int ttwu_remote(struct task_struct *p, int wake_flags) | |
1540 | { | |
1541 | struct rq *rq; | |
1542 | int ret = 0; | |
1543 | ||
1544 | rq = __task_rq_lock(p); | |
da0c1e65 | 1545 | if (task_on_rq_queued(p)) { |
1ad4ec0d FW |
1546 | /* check_preempt_curr() may use rq clock */ |
1547 | update_rq_clock(rq); | |
c05fbafb PZ |
1548 | ttwu_do_wakeup(rq, p, wake_flags); |
1549 | ret = 1; | |
1550 | } | |
1551 | __task_rq_unlock(rq); | |
1552 | ||
1553 | return ret; | |
1554 | } | |
1555 | ||
317f3941 | 1556 | #ifdef CONFIG_SMP |
e3baac47 | 1557 | void sched_ttwu_pending(void) |
317f3941 PZ |
1558 | { |
1559 | struct rq *rq = this_rq(); | |
fa14ff4a PZ |
1560 | struct llist_node *llist = llist_del_all(&rq->wake_list); |
1561 | struct task_struct *p; | |
e3baac47 | 1562 | unsigned long flags; |
317f3941 | 1563 | |
e3baac47 PZ |
1564 | if (!llist) |
1565 | return; | |
1566 | ||
1567 | raw_spin_lock_irqsave(&rq->lock, flags); | |
317f3941 | 1568 | |
fa14ff4a PZ |
1569 | while (llist) { |
1570 | p = llist_entry(llist, struct task_struct, wake_entry); | |
1571 | llist = llist_next(llist); | |
317f3941 PZ |
1572 | ttwu_do_activate(rq, p, 0); |
1573 | } | |
1574 | ||
e3baac47 | 1575 | raw_spin_unlock_irqrestore(&rq->lock, flags); |
317f3941 PZ |
1576 | } |
1577 | ||
1578 | void scheduler_ipi(void) | |
1579 | { | |
f27dde8d PZ |
1580 | /* |
1581 | * Fold TIF_NEED_RESCHED into the preempt_count; anybody setting | |
1582 | * TIF_NEED_RESCHED remotely (for the first time) will also send | |
1583 | * this IPI. | |
1584 | */ | |
8cb75e0c | 1585 | preempt_fold_need_resched(); |
f27dde8d | 1586 | |
fd2ac4f4 | 1587 | if (llist_empty(&this_rq()->wake_list) && !got_nohz_idle_kick()) |
c5d753a5 PZ |
1588 | return; |
1589 | ||
1590 | /* | |
1591 | * Not all reschedule IPI handlers call irq_enter/irq_exit, since | |
1592 | * traditionally all their work was done from the interrupt return | |
1593 | * path. Now that we actually do some work, we need to make sure | |
1594 | * we do call them. | |
1595 | * | |
1596 | * Some archs already do call them, luckily irq_enter/exit nest | |
1597 | * properly. | |
1598 | * | |
1599 | * Arguably we should visit all archs and update all handlers, | |
1600 | * however a fair share of IPIs are still resched only so this would | |
1601 | * somewhat pessimize the simple resched case. | |
1602 | */ | |
1603 | irq_enter(); | |
fa14ff4a | 1604 | sched_ttwu_pending(); |
ca38062e SS |
1605 | |
1606 | /* | |
1607 | * Check if someone kicked us for doing the nohz idle load balance. | |
1608 | */ | |
873b4c65 | 1609 | if (unlikely(got_nohz_idle_kick())) { |
6eb57e0d | 1610 | this_rq()->idle_balance = 1; |
ca38062e | 1611 | raise_softirq_irqoff(SCHED_SOFTIRQ); |
6eb57e0d | 1612 | } |
c5d753a5 | 1613 | irq_exit(); |
317f3941 PZ |
1614 | } |
1615 | ||
1616 | static void ttwu_queue_remote(struct task_struct *p, int cpu) | |
1617 | { | |
e3baac47 PZ |
1618 | struct rq *rq = cpu_rq(cpu); |
1619 | ||
1620 | if (llist_add(&p->wake_entry, &cpu_rq(cpu)->wake_list)) { | |
1621 | if (!set_nr_if_polling(rq->idle)) | |
1622 | smp_send_reschedule(cpu); | |
1623 | else | |
1624 | trace_sched_wake_idle_without_ipi(cpu); | |
1625 | } | |
317f3941 | 1626 | } |
d6aa8f85 | 1627 | |
f6be8af1 CL |
1628 | void wake_up_if_idle(int cpu) |
1629 | { | |
1630 | struct rq *rq = cpu_rq(cpu); | |
1631 | unsigned long flags; | |
1632 | ||
fd7de1e8 AL |
1633 | rcu_read_lock(); |
1634 | ||
1635 | if (!is_idle_task(rcu_dereference(rq->curr))) | |
1636 | goto out; | |
f6be8af1 CL |
1637 | |
1638 | if (set_nr_if_polling(rq->idle)) { | |
1639 | trace_sched_wake_idle_without_ipi(cpu); | |
1640 | } else { | |
1641 | raw_spin_lock_irqsave(&rq->lock, flags); | |
1642 | if (is_idle_task(rq->curr)) | |
1643 | smp_send_reschedule(cpu); | |
1644 | /* Else cpu is not in idle, do nothing here */ | |
1645 | raw_spin_unlock_irqrestore(&rq->lock, flags); | |
1646 | } | |
fd7de1e8 AL |
1647 | |
1648 | out: | |
1649 | rcu_read_unlock(); | |
f6be8af1 CL |
1650 | } |
1651 | ||
39be3501 | 1652 | bool cpus_share_cache(int this_cpu, int that_cpu) |
518cd623 PZ |
1653 | { |
1654 | return per_cpu(sd_llc_id, this_cpu) == per_cpu(sd_llc_id, that_cpu); | |
1655 | } | |
d6aa8f85 | 1656 | #endif /* CONFIG_SMP */ |
317f3941 | 1657 | |
c05fbafb PZ |
1658 | static void ttwu_queue(struct task_struct *p, int cpu) |
1659 | { | |
1660 | struct rq *rq = cpu_rq(cpu); | |
1661 | ||
17d9f311 | 1662 | #if defined(CONFIG_SMP) |
39be3501 | 1663 | if (sched_feat(TTWU_QUEUE) && !cpus_share_cache(smp_processor_id(), cpu)) { |
f01114cb | 1664 | sched_clock_cpu(cpu); /* sync clocks x-cpu */ |
317f3941 PZ |
1665 | ttwu_queue_remote(p, cpu); |
1666 | return; | |
1667 | } | |
1668 | #endif | |
1669 | ||
c05fbafb PZ |
1670 | raw_spin_lock(&rq->lock); |
1671 | ttwu_do_activate(rq, p, 0); | |
1672 | raw_spin_unlock(&rq->lock); | |
9ed3811a TH |
1673 | } |
1674 | ||
1675 | /** | |
1da177e4 | 1676 | * try_to_wake_up - wake up a thread |
9ed3811a | 1677 | * @p: the thread to be awakened |
1da177e4 | 1678 | * @state: the mask of task states that can be woken |
9ed3811a | 1679 | * @wake_flags: wake modifier flags (WF_*) |
1da177e4 LT |
1680 | * |
1681 | * Put it on the run-queue if it's not already there. The "current" | |
1682 | * thread is always on the run-queue (except when the actual | |
1683 | * re-schedule is in progress), and as such you're allowed to do | |
1684 | * the simpler "current->state = TASK_RUNNING" to mark yourself | |
1685 | * runnable without the overhead of this. | |
1686 | * | |
e69f6186 | 1687 | * Return: %true if @p was woken up, %false if it was already running. |
9ed3811a | 1688 | * or @state didn't match @p's state. |
1da177e4 | 1689 | */ |
e4a52bcb PZ |
1690 | static int |
1691 | try_to_wake_up(struct task_struct *p, unsigned int state, int wake_flags) | |
1da177e4 | 1692 | { |
1da177e4 | 1693 | unsigned long flags; |
c05fbafb | 1694 | int cpu, success = 0; |
2398f2c6 | 1695 | |
e0acd0a6 ON |
1696 | /* |
1697 | * If we are going to wake up a thread waiting for CONDITION we | |
1698 | * need to ensure that CONDITION=1 done by the caller can not be | |
1699 | * reordered with p->state check below. This pairs with mb() in | |
1700 | * set_current_state() the waiting thread does. | |
1701 | */ | |
1702 | smp_mb__before_spinlock(); | |
013fdb80 | 1703 | raw_spin_lock_irqsave(&p->pi_lock, flags); |
e9c84311 | 1704 | if (!(p->state & state)) |
1da177e4 LT |
1705 | goto out; |
1706 | ||
c05fbafb | 1707 | success = 1; /* we're going to change ->state */ |
1da177e4 | 1708 | cpu = task_cpu(p); |
1da177e4 | 1709 | |
c05fbafb PZ |
1710 | if (p->on_rq && ttwu_remote(p, wake_flags)) |
1711 | goto stat; | |
1da177e4 | 1712 | |
1da177e4 | 1713 | #ifdef CONFIG_SMP |
e9c84311 | 1714 | /* |
c05fbafb PZ |
1715 | * If the owning (remote) cpu is still in the middle of schedule() with |
1716 | * this task as prev, wait until its done referencing the task. | |
e9c84311 | 1717 | */ |
f3e94786 | 1718 | while (p->on_cpu) |
e4a52bcb | 1719 | cpu_relax(); |
0970d299 | 1720 | /* |
e4a52bcb | 1721 | * Pairs with the smp_wmb() in finish_lock_switch(). |
0970d299 | 1722 | */ |
e4a52bcb | 1723 | smp_rmb(); |
1da177e4 | 1724 | |
a8e4f2ea | 1725 | p->sched_contributes_to_load = !!task_contributes_to_load(p); |
e9c84311 | 1726 | p->state = TASK_WAKING; |
e7693a36 | 1727 | |
e4a52bcb | 1728 | if (p->sched_class->task_waking) |
74f8e4b2 | 1729 | p->sched_class->task_waking(p); |
efbbd05a | 1730 | |
ac66f547 | 1731 | cpu = select_task_rq(p, p->wake_cpu, SD_BALANCE_WAKE, wake_flags); |
f339b9dc PZ |
1732 | if (task_cpu(p) != cpu) { |
1733 | wake_flags |= WF_MIGRATED; | |
e4a52bcb | 1734 | set_task_cpu(p, cpu); |
f339b9dc | 1735 | } |
1da177e4 | 1736 | #endif /* CONFIG_SMP */ |
1da177e4 | 1737 | |
c05fbafb PZ |
1738 | ttwu_queue(p, cpu); |
1739 | stat: | |
b84cb5df | 1740 | ttwu_stat(p, cpu, wake_flags); |
1da177e4 | 1741 | out: |
013fdb80 | 1742 | raw_spin_unlock_irqrestore(&p->pi_lock, flags); |
1da177e4 LT |
1743 | |
1744 | return success; | |
1745 | } | |
1746 | ||
21aa9af0 TH |
1747 | /** |
1748 | * try_to_wake_up_local - try to wake up a local task with rq lock held | |
1749 | * @p: the thread to be awakened | |
1750 | * | |
2acca55e | 1751 | * Put @p on the run-queue if it's not already there. The caller must |
21aa9af0 | 1752 | * ensure that this_rq() is locked, @p is bound to this_rq() and not |
2acca55e | 1753 | * the current task. |
21aa9af0 TH |
1754 | */ |
1755 | static void try_to_wake_up_local(struct task_struct *p) | |
1756 | { | |
1757 | struct rq *rq = task_rq(p); | |
21aa9af0 | 1758 | |
383efcd0 TH |
1759 | if (WARN_ON_ONCE(rq != this_rq()) || |
1760 | WARN_ON_ONCE(p == current)) | |
1761 | return; | |
1762 | ||
21aa9af0 TH |
1763 | lockdep_assert_held(&rq->lock); |
1764 | ||
2acca55e PZ |
1765 | if (!raw_spin_trylock(&p->pi_lock)) { |
1766 | raw_spin_unlock(&rq->lock); | |
1767 | raw_spin_lock(&p->pi_lock); | |
1768 | raw_spin_lock(&rq->lock); | |
1769 | } | |
1770 | ||
21aa9af0 | 1771 | if (!(p->state & TASK_NORMAL)) |
2acca55e | 1772 | goto out; |
21aa9af0 | 1773 | |
da0c1e65 | 1774 | if (!task_on_rq_queued(p)) |
d7c01d27 PZ |
1775 | ttwu_activate(rq, p, ENQUEUE_WAKEUP); |
1776 | ||
23f41eeb | 1777 | ttwu_do_wakeup(rq, p, 0); |
b84cb5df | 1778 | ttwu_stat(p, smp_processor_id(), 0); |
2acca55e PZ |
1779 | out: |
1780 | raw_spin_unlock(&p->pi_lock); | |
21aa9af0 TH |
1781 | } |
1782 | ||
50fa610a DH |
1783 | /** |
1784 | * wake_up_process - Wake up a specific process | |
1785 | * @p: The process to be woken up. | |
1786 | * | |
1787 | * Attempt to wake up the nominated process and move it to the set of runnable | |
e69f6186 YB |
1788 | * processes. |
1789 | * | |
1790 | * Return: 1 if the process was woken up, 0 if it was already running. | |
50fa610a DH |
1791 | * |
1792 | * It may be assumed that this function implies a write memory barrier before | |
1793 | * changing the task state if and only if any tasks are woken up. | |
1794 | */ | |
7ad5b3a5 | 1795 | int wake_up_process(struct task_struct *p) |
1da177e4 | 1796 | { |
9067ac85 ON |
1797 | WARN_ON(task_is_stopped_or_traced(p)); |
1798 | return try_to_wake_up(p, TASK_NORMAL, 0); | |
1da177e4 | 1799 | } |
1da177e4 LT |
1800 | EXPORT_SYMBOL(wake_up_process); |
1801 | ||
7ad5b3a5 | 1802 | int wake_up_state(struct task_struct *p, unsigned int state) |
1da177e4 LT |
1803 | { |
1804 | return try_to_wake_up(p, state, 0); | |
1805 | } | |
1806 | ||
a5e7be3b JL |
1807 | /* |
1808 | * This function clears the sched_dl_entity static params. | |
1809 | */ | |
1810 | void __dl_clear_params(struct task_struct *p) | |
1811 | { | |
1812 | struct sched_dl_entity *dl_se = &p->dl; | |
1813 | ||
1814 | dl_se->dl_runtime = 0; | |
1815 | dl_se->dl_deadline = 0; | |
1816 | dl_se->dl_period = 0; | |
1817 | dl_se->flags = 0; | |
1818 | dl_se->dl_bw = 0; | |
40767b0d PZ |
1819 | |
1820 | dl_se->dl_throttled = 0; | |
1821 | dl_se->dl_new = 1; | |
1822 | dl_se->dl_yielded = 0; | |
a5e7be3b JL |
1823 | } |
1824 | ||
1da177e4 LT |
1825 | /* |
1826 | * Perform scheduler related setup for a newly forked process p. | |
1827 | * p is forked by current. | |
dd41f596 IM |
1828 | * |
1829 | * __sched_fork() is basic setup used by init_idle() too: | |
1830 | */ | |
5e1576ed | 1831 | static void __sched_fork(unsigned long clone_flags, struct task_struct *p) |
dd41f596 | 1832 | { |
fd2f4419 PZ |
1833 | p->on_rq = 0; |
1834 | ||
1835 | p->se.on_rq = 0; | |
dd41f596 IM |
1836 | p->se.exec_start = 0; |
1837 | p->se.sum_exec_runtime = 0; | |
f6cf891c | 1838 | p->se.prev_sum_exec_runtime = 0; |
6c594c21 | 1839 | p->se.nr_migrations = 0; |
da7a735e | 1840 | p->se.vruntime = 0; |
bb04159d KT |
1841 | #ifdef CONFIG_SMP |
1842 | p->se.avg.decay_count = 0; | |
1843 | #endif | |
fd2f4419 | 1844 | INIT_LIST_HEAD(&p->se.group_node); |
6cfb0d5d IM |
1845 | |
1846 | #ifdef CONFIG_SCHEDSTATS | |
41acab88 | 1847 | memset(&p->se.statistics, 0, sizeof(p->se.statistics)); |
6cfb0d5d | 1848 | #endif |
476d139c | 1849 | |
aab03e05 | 1850 | RB_CLEAR_NODE(&p->dl.rb_node); |
40767b0d | 1851 | init_dl_task_timer(&p->dl); |
a5e7be3b | 1852 | __dl_clear_params(p); |
aab03e05 | 1853 | |
fa717060 | 1854 | INIT_LIST_HEAD(&p->rt.run_list); |
476d139c | 1855 | |
e107be36 AK |
1856 | #ifdef CONFIG_PREEMPT_NOTIFIERS |
1857 | INIT_HLIST_HEAD(&p->preempt_notifiers); | |
1858 | #endif | |
cbee9f88 PZ |
1859 | |
1860 | #ifdef CONFIG_NUMA_BALANCING | |
1861 | if (p->mm && atomic_read(&p->mm->mm_users) == 1) { | |
7e8d16b6 | 1862 | p->mm->numa_next_scan = jiffies + msecs_to_jiffies(sysctl_numa_balancing_scan_delay); |
cbee9f88 PZ |
1863 | p->mm->numa_scan_seq = 0; |
1864 | } | |
1865 | ||
5e1576ed RR |
1866 | if (clone_flags & CLONE_VM) |
1867 | p->numa_preferred_nid = current->numa_preferred_nid; | |
1868 | else | |
1869 | p->numa_preferred_nid = -1; | |
1870 | ||
cbee9f88 PZ |
1871 | p->node_stamp = 0ULL; |
1872 | p->numa_scan_seq = p->mm ? p->mm->numa_scan_seq : 0; | |
4b96a29b | 1873 | p->numa_scan_period = sysctl_numa_balancing_scan_delay; |
cbee9f88 | 1874 | p->numa_work.next = &p->numa_work; |
44dba3d5 | 1875 | p->numa_faults = NULL; |
7e2703e6 RR |
1876 | p->last_task_numa_placement = 0; |
1877 | p->last_sum_exec_runtime = 0; | |
8c8a743c | 1878 | |
8c8a743c | 1879 | p->numa_group = NULL; |
cbee9f88 | 1880 | #endif /* CONFIG_NUMA_BALANCING */ |
dd41f596 IM |
1881 | } |
1882 | ||
1a687c2e | 1883 | #ifdef CONFIG_NUMA_BALANCING |
3105b86a | 1884 | #ifdef CONFIG_SCHED_DEBUG |
1a687c2e MG |
1885 | void set_numabalancing_state(bool enabled) |
1886 | { | |
1887 | if (enabled) | |
1888 | sched_feat_set("NUMA"); | |
1889 | else | |
1890 | sched_feat_set("NO_NUMA"); | |
1891 | } | |
3105b86a MG |
1892 | #else |
1893 | __read_mostly bool numabalancing_enabled; | |
1894 | ||
1895 | void set_numabalancing_state(bool enabled) | |
1896 | { | |
1897 | numabalancing_enabled = enabled; | |
dd41f596 | 1898 | } |
3105b86a | 1899 | #endif /* CONFIG_SCHED_DEBUG */ |
54a43d54 AK |
1900 | |
1901 | #ifdef CONFIG_PROC_SYSCTL | |
1902 | int sysctl_numa_balancing(struct ctl_table *table, int write, | |
1903 | void __user *buffer, size_t *lenp, loff_t *ppos) | |
1904 | { | |
1905 | struct ctl_table t; | |
1906 | int err; | |
1907 | int state = numabalancing_enabled; | |
1908 | ||
1909 | if (write && !capable(CAP_SYS_ADMIN)) | |
1910 | return -EPERM; | |
1911 | ||
1912 | t = *table; | |
1913 | t.data = &state; | |
1914 | err = proc_dointvec_minmax(&t, write, buffer, lenp, ppos); | |
1915 | if (err < 0) | |
1916 | return err; | |
1917 | if (write) | |
1918 | set_numabalancing_state(state); | |
1919 | return err; | |
1920 | } | |
1921 | #endif | |
1922 | #endif | |
dd41f596 IM |
1923 | |
1924 | /* | |
1925 | * fork()/clone()-time setup: | |
1926 | */ | |
aab03e05 | 1927 | int sched_fork(unsigned long clone_flags, struct task_struct *p) |
dd41f596 | 1928 | { |
0122ec5b | 1929 | unsigned long flags; |
dd41f596 IM |
1930 | int cpu = get_cpu(); |
1931 | ||
5e1576ed | 1932 | __sched_fork(clone_flags, p); |
06b83b5f | 1933 | /* |
0017d735 | 1934 | * We mark the process as running here. This guarantees that |
06b83b5f PZ |
1935 | * nobody will actually run it, and a signal or other external |
1936 | * event cannot wake it up and insert it on the runqueue either. | |
1937 | */ | |
0017d735 | 1938 | p->state = TASK_RUNNING; |
dd41f596 | 1939 | |
c350a04e MG |
1940 | /* |
1941 | * Make sure we do not leak PI boosting priority to the child. | |
1942 | */ | |
1943 | p->prio = current->normal_prio; | |
1944 | ||
b9dc29e7 MG |
1945 | /* |
1946 | * Revert to default priority/policy on fork if requested. | |
1947 | */ | |
1948 | if (unlikely(p->sched_reset_on_fork)) { | |
aab03e05 | 1949 | if (task_has_dl_policy(p) || task_has_rt_policy(p)) { |
b9dc29e7 | 1950 | p->policy = SCHED_NORMAL; |
6c697bdf | 1951 | p->static_prio = NICE_TO_PRIO(0); |
c350a04e MG |
1952 | p->rt_priority = 0; |
1953 | } else if (PRIO_TO_NICE(p->static_prio) < 0) | |
1954 | p->static_prio = NICE_TO_PRIO(0); | |
1955 | ||
1956 | p->prio = p->normal_prio = __normal_prio(p); | |
1957 | set_load_weight(p); | |
6c697bdf | 1958 | |
b9dc29e7 MG |
1959 | /* |
1960 | * We don't need the reset flag anymore after the fork. It has | |
1961 | * fulfilled its duty: | |
1962 | */ | |
1963 | p->sched_reset_on_fork = 0; | |
1964 | } | |
ca94c442 | 1965 | |
aab03e05 DF |
1966 | if (dl_prio(p->prio)) { |
1967 | put_cpu(); | |
1968 | return -EAGAIN; | |
1969 | } else if (rt_prio(p->prio)) { | |
1970 | p->sched_class = &rt_sched_class; | |
1971 | } else { | |
2ddbf952 | 1972 | p->sched_class = &fair_sched_class; |
aab03e05 | 1973 | } |
b29739f9 | 1974 | |
cd29fe6f PZ |
1975 | if (p->sched_class->task_fork) |
1976 | p->sched_class->task_fork(p); | |
1977 | ||
86951599 PZ |
1978 | /* |
1979 | * The child is not yet in the pid-hash so no cgroup attach races, | |
1980 | * and the cgroup is pinned to this child due to cgroup_fork() | |
1981 | * is ran before sched_fork(). | |
1982 | * | |
1983 | * Silence PROVE_RCU. | |
1984 | */ | |
0122ec5b | 1985 | raw_spin_lock_irqsave(&p->pi_lock, flags); |
5f3edc1b | 1986 | set_task_cpu(p, cpu); |
0122ec5b | 1987 | raw_spin_unlock_irqrestore(&p->pi_lock, flags); |
5f3edc1b | 1988 | |
52f17b6c | 1989 | #if defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT) |
dd41f596 | 1990 | if (likely(sched_info_on())) |
52f17b6c | 1991 | memset(&p->sched_info, 0, sizeof(p->sched_info)); |
1da177e4 | 1992 | #endif |
3ca7a440 PZ |
1993 | #if defined(CONFIG_SMP) |
1994 | p->on_cpu = 0; | |
4866cde0 | 1995 | #endif |
01028747 | 1996 | init_task_preempt_count(p); |
806c09a7 | 1997 | #ifdef CONFIG_SMP |
917b627d | 1998 | plist_node_init(&p->pushable_tasks, MAX_PRIO); |
1baca4ce | 1999 | RB_CLEAR_NODE(&p->pushable_dl_tasks); |
806c09a7 | 2000 | #endif |
917b627d | 2001 | |
476d139c | 2002 | put_cpu(); |
aab03e05 | 2003 | return 0; |
1da177e4 LT |
2004 | } |
2005 | ||
332ac17e DF |
2006 | unsigned long to_ratio(u64 period, u64 runtime) |
2007 | { | |
2008 | if (runtime == RUNTIME_INF) | |
2009 | return 1ULL << 20; | |
2010 | ||
2011 | /* | |
2012 | * Doing this here saves a lot of checks in all | |
2013 | * the calling paths, and returning zero seems | |
2014 | * safe for them anyway. | |
2015 | */ | |
2016 | if (period == 0) | |
2017 | return 0; | |
2018 | ||
2019 | return div64_u64(runtime << 20, period); | |
2020 | } | |
2021 | ||
2022 | #ifdef CONFIG_SMP | |
2023 | inline struct dl_bw *dl_bw_of(int i) | |
2024 | { | |
66339c31 KT |
2025 | rcu_lockdep_assert(rcu_read_lock_sched_held(), |
2026 | "sched RCU must be held"); | |
332ac17e DF |
2027 | return &cpu_rq(i)->rd->dl_bw; |
2028 | } | |
2029 | ||
de212f18 | 2030 | static inline int dl_bw_cpus(int i) |
332ac17e | 2031 | { |
de212f18 PZ |
2032 | struct root_domain *rd = cpu_rq(i)->rd; |
2033 | int cpus = 0; | |
2034 | ||
66339c31 KT |
2035 | rcu_lockdep_assert(rcu_read_lock_sched_held(), |
2036 | "sched RCU must be held"); | |
de212f18 PZ |
2037 | for_each_cpu_and(i, rd->span, cpu_active_mask) |
2038 | cpus++; | |
2039 | ||
2040 | return cpus; | |
332ac17e DF |
2041 | } |
2042 | #else | |
2043 | inline struct dl_bw *dl_bw_of(int i) | |
2044 | { | |
2045 | return &cpu_rq(i)->dl.dl_bw; | |
2046 | } | |
2047 | ||
de212f18 | 2048 | static inline int dl_bw_cpus(int i) |
332ac17e DF |
2049 | { |
2050 | return 1; | |
2051 | } | |
2052 | #endif | |
2053 | ||
332ac17e DF |
2054 | /* |
2055 | * We must be sure that accepting a new task (or allowing changing the | |
2056 | * parameters of an existing one) is consistent with the bandwidth | |
2057 | * constraints. If yes, this function also accordingly updates the currently | |
2058 | * allocated bandwidth to reflect the new situation. | |
2059 | * | |
2060 | * This function is called while holding p's rq->lock. | |
40767b0d PZ |
2061 | * |
2062 | * XXX we should delay bw change until the task's 0-lag point, see | |
2063 | * __setparam_dl(). | |
332ac17e DF |
2064 | */ |
2065 | static int dl_overflow(struct task_struct *p, int policy, | |
2066 | const struct sched_attr *attr) | |
2067 | { | |
2068 | ||
2069 | struct dl_bw *dl_b = dl_bw_of(task_cpu(p)); | |
4df1638c | 2070 | u64 period = attr->sched_period ?: attr->sched_deadline; |
332ac17e DF |
2071 | u64 runtime = attr->sched_runtime; |
2072 | u64 new_bw = dl_policy(policy) ? to_ratio(period, runtime) : 0; | |
de212f18 | 2073 | int cpus, err = -1; |
332ac17e DF |
2074 | |
2075 | if (new_bw == p->dl.dl_bw) | |
2076 | return 0; | |
2077 | ||
2078 | /* | |
2079 | * Either if a task, enters, leave, or stays -deadline but changes | |
2080 | * its parameters, we may need to update accordingly the total | |
2081 | * allocated bandwidth of the container. | |
2082 | */ | |
2083 | raw_spin_lock(&dl_b->lock); | |
de212f18 | 2084 | cpus = dl_bw_cpus(task_cpu(p)); |
332ac17e DF |
2085 | if (dl_policy(policy) && !task_has_dl_policy(p) && |
2086 | !__dl_overflow(dl_b, cpus, 0, new_bw)) { | |
2087 | __dl_add(dl_b, new_bw); | |
2088 | err = 0; | |
2089 | } else if (dl_policy(policy) && task_has_dl_policy(p) && | |
2090 | !__dl_overflow(dl_b, cpus, p->dl.dl_bw, new_bw)) { | |
2091 | __dl_clear(dl_b, p->dl.dl_bw); | |
2092 | __dl_add(dl_b, new_bw); | |
2093 | err = 0; | |
2094 | } else if (!dl_policy(policy) && task_has_dl_policy(p)) { | |
2095 | __dl_clear(dl_b, p->dl.dl_bw); | |
2096 | err = 0; | |
2097 | } | |
2098 | raw_spin_unlock(&dl_b->lock); | |
2099 | ||
2100 | return err; | |
2101 | } | |
2102 | ||
2103 | extern void init_dl_bw(struct dl_bw *dl_b); | |
2104 | ||
1da177e4 LT |
2105 | /* |
2106 | * wake_up_new_task - wake up a newly created task for the first time. | |
2107 | * | |
2108 | * This function will do some initial scheduler statistics housekeeping | |
2109 | * that must be done for every newly created context, then puts the task | |
2110 | * on the runqueue and wakes it. | |
2111 | */ | |
3e51e3ed | 2112 | void wake_up_new_task(struct task_struct *p) |
1da177e4 LT |
2113 | { |
2114 | unsigned long flags; | |
dd41f596 | 2115 | struct rq *rq; |
fabf318e | 2116 | |
ab2515c4 | 2117 | raw_spin_lock_irqsave(&p->pi_lock, flags); |
fabf318e PZ |
2118 | #ifdef CONFIG_SMP |
2119 | /* | |
2120 | * Fork balancing, do it here and not earlier because: | |
2121 | * - cpus_allowed can change in the fork path | |
2122 | * - any previously selected cpu might disappear through hotplug | |
fabf318e | 2123 | */ |
ac66f547 | 2124 | set_task_cpu(p, select_task_rq(p, task_cpu(p), SD_BALANCE_FORK, 0)); |
0017d735 PZ |
2125 | #endif |
2126 | ||
a75cdaa9 AS |
2127 | /* Initialize new task's runnable average */ |
2128 | init_task_runnable_average(p); | |
ab2515c4 | 2129 | rq = __task_rq_lock(p); |
cd29fe6f | 2130 | activate_task(rq, p, 0); |
da0c1e65 | 2131 | p->on_rq = TASK_ON_RQ_QUEUED; |
89363381 | 2132 | trace_sched_wakeup_new(p, true); |
a7558e01 | 2133 | check_preempt_curr(rq, p, WF_FORK); |
9a897c5a | 2134 | #ifdef CONFIG_SMP |
efbbd05a PZ |
2135 | if (p->sched_class->task_woken) |
2136 | p->sched_class->task_woken(rq, p); | |
9a897c5a | 2137 | #endif |
0122ec5b | 2138 | task_rq_unlock(rq, p, &flags); |
1da177e4 LT |
2139 | } |
2140 | ||
e107be36 AK |
2141 | #ifdef CONFIG_PREEMPT_NOTIFIERS |
2142 | ||
2143 | /** | |
80dd99b3 | 2144 | * preempt_notifier_register - tell me when current is being preempted & rescheduled |
421cee29 | 2145 | * @notifier: notifier struct to register |
e107be36 AK |
2146 | */ |
2147 | void preempt_notifier_register(struct preempt_notifier *notifier) | |
2148 | { | |
2149 | hlist_add_head(¬ifier->link, ¤t->preempt_notifiers); | |
2150 | } | |
2151 | EXPORT_SYMBOL_GPL(preempt_notifier_register); | |
2152 | ||
2153 | /** | |
2154 | * preempt_notifier_unregister - no longer interested in preemption notifications | |
421cee29 | 2155 | * @notifier: notifier struct to unregister |
e107be36 AK |
2156 | * |
2157 | * This is safe to call from within a preemption notifier. | |
2158 | */ | |
2159 | void preempt_notifier_unregister(struct preempt_notifier *notifier) | |
2160 | { | |
2161 | hlist_del(¬ifier->link); | |
2162 | } | |
2163 | EXPORT_SYMBOL_GPL(preempt_notifier_unregister); | |
2164 | ||
2165 | static void fire_sched_in_preempt_notifiers(struct task_struct *curr) | |
2166 | { | |
2167 | struct preempt_notifier *notifier; | |
e107be36 | 2168 | |
b67bfe0d | 2169 | hlist_for_each_entry(notifier, &curr->preempt_notifiers, link) |
e107be36 AK |
2170 | notifier->ops->sched_in(notifier, raw_smp_processor_id()); |
2171 | } | |
2172 | ||
2173 | static void | |
2174 | fire_sched_out_preempt_notifiers(struct task_struct *curr, | |
2175 | struct task_struct *next) | |
2176 | { | |
2177 | struct preempt_notifier *notifier; | |
e107be36 | 2178 | |
b67bfe0d | 2179 | hlist_for_each_entry(notifier, &curr->preempt_notifiers, link) |
e107be36 AK |
2180 | notifier->ops->sched_out(notifier, next); |
2181 | } | |
2182 | ||
6d6bc0ad | 2183 | #else /* !CONFIG_PREEMPT_NOTIFIERS */ |
e107be36 AK |
2184 | |
2185 | static void fire_sched_in_preempt_notifiers(struct task_struct *curr) | |
2186 | { | |
2187 | } | |
2188 | ||
2189 | static void | |
2190 | fire_sched_out_preempt_notifiers(struct task_struct *curr, | |
2191 | struct task_struct *next) | |
2192 | { | |
2193 | } | |
2194 | ||
6d6bc0ad | 2195 | #endif /* CONFIG_PREEMPT_NOTIFIERS */ |
e107be36 | 2196 | |
4866cde0 NP |
2197 | /** |
2198 | * prepare_task_switch - prepare to switch tasks | |
2199 | * @rq: the runqueue preparing to switch | |
421cee29 | 2200 | * @prev: the current task that is being switched out |
4866cde0 NP |
2201 | * @next: the task we are going to switch to. |
2202 | * | |
2203 | * This is called with the rq lock held and interrupts off. It must | |
2204 | * be paired with a subsequent finish_task_switch after the context | |
2205 | * switch. | |
2206 | * | |
2207 | * prepare_task_switch sets up locking and calls architecture specific | |
2208 | * hooks. | |
2209 | */ | |
e107be36 AK |
2210 | static inline void |
2211 | prepare_task_switch(struct rq *rq, struct task_struct *prev, | |
2212 | struct task_struct *next) | |
4866cde0 | 2213 | { |
895dd92c | 2214 | trace_sched_switch(prev, next); |
43148951 | 2215 | sched_info_switch(rq, prev, next); |
fe4b04fa | 2216 | perf_event_task_sched_out(prev, next); |
e107be36 | 2217 | fire_sched_out_preempt_notifiers(prev, next); |
4866cde0 NP |
2218 | prepare_lock_switch(rq, next); |
2219 | prepare_arch_switch(next); | |
2220 | } | |
2221 | ||
1da177e4 LT |
2222 | /** |
2223 | * finish_task_switch - clean up after a task-switch | |
2224 | * @prev: the thread we just switched away from. | |
2225 | * | |
4866cde0 NP |
2226 | * finish_task_switch must be called after the context switch, paired |
2227 | * with a prepare_task_switch call before the context switch. | |
2228 | * finish_task_switch will reconcile locking set up by prepare_task_switch, | |
2229 | * and do any other architecture-specific cleanup actions. | |
1da177e4 LT |
2230 | * |
2231 | * Note that we may have delayed dropping an mm in context_switch(). If | |
41a2d6cf | 2232 | * so, we finish that here outside of the runqueue lock. (Doing it |
1da177e4 LT |
2233 | * with the lock held can cause deadlocks; see schedule() for |
2234 | * details.) | |
dfa50b60 ON |
2235 | * |
2236 | * The context switch have flipped the stack from under us and restored the | |
2237 | * local variables which were saved when this task called schedule() in the | |
2238 | * past. prev == current is still correct but we need to recalculate this_rq | |
2239 | * because prev may have moved to another CPU. | |
1da177e4 | 2240 | */ |
dfa50b60 | 2241 | static struct rq *finish_task_switch(struct task_struct *prev) |
1da177e4 LT |
2242 | __releases(rq->lock) |
2243 | { | |
dfa50b60 | 2244 | struct rq *rq = this_rq(); |
1da177e4 | 2245 | struct mm_struct *mm = rq->prev_mm; |
55a101f8 | 2246 | long prev_state; |
1da177e4 LT |
2247 | |
2248 | rq->prev_mm = NULL; | |
2249 | ||
2250 | /* | |
2251 | * A task struct has one reference for the use as "current". | |
c394cc9f | 2252 | * If a task dies, then it sets TASK_DEAD in tsk->state and calls |
55a101f8 ON |
2253 | * schedule one last time. The schedule call will never return, and |
2254 | * the scheduled task must drop that reference. | |
c394cc9f | 2255 | * The test for TASK_DEAD must occur while the runqueue locks are |
1da177e4 LT |
2256 | * still held, otherwise prev could be scheduled on another cpu, die |
2257 | * there before we look at prev->state, and then the reference would | |
2258 | * be dropped twice. | |
2259 | * Manfred Spraul <manfred@colorfullife.com> | |
2260 | */ | |
55a101f8 | 2261 | prev_state = prev->state; |
bf9fae9f | 2262 | vtime_task_switch(prev); |
4866cde0 | 2263 | finish_arch_switch(prev); |
a8d757ef | 2264 | perf_event_task_sched_in(prev, current); |
4866cde0 | 2265 | finish_lock_switch(rq, prev); |
01f23e16 | 2266 | finish_arch_post_lock_switch(); |
e8fa1362 | 2267 | |
e107be36 | 2268 | fire_sched_in_preempt_notifiers(current); |
1da177e4 LT |
2269 | if (mm) |
2270 | mmdrop(mm); | |
c394cc9f | 2271 | if (unlikely(prev_state == TASK_DEAD)) { |
e6c390f2 DF |
2272 | if (prev->sched_class->task_dead) |
2273 | prev->sched_class->task_dead(prev); | |
2274 | ||
c6fd91f0 | 2275 | /* |
2276 | * Remove function-return probe instances associated with this | |
2277 | * task and put them back on the free list. | |
9761eea8 | 2278 | */ |
c6fd91f0 | 2279 | kprobe_flush_task(prev); |
1da177e4 | 2280 | put_task_struct(prev); |
c6fd91f0 | 2281 | } |
99e5ada9 FW |
2282 | |
2283 | tick_nohz_task_switch(current); | |
dfa50b60 | 2284 | return rq; |
1da177e4 LT |
2285 | } |
2286 | ||
3f029d3c GH |
2287 | #ifdef CONFIG_SMP |
2288 | ||
3f029d3c GH |
2289 | /* rq->lock is NOT held, but preemption is disabled */ |
2290 | static inline void post_schedule(struct rq *rq) | |
2291 | { | |
2292 | if (rq->post_schedule) { | |
2293 | unsigned long flags; | |
2294 | ||
05fa785c | 2295 | raw_spin_lock_irqsave(&rq->lock, flags); |
3f029d3c GH |
2296 | if (rq->curr->sched_class->post_schedule) |
2297 | rq->curr->sched_class->post_schedule(rq); | |
05fa785c | 2298 | raw_spin_unlock_irqrestore(&rq->lock, flags); |
3f029d3c GH |
2299 | |
2300 | rq->post_schedule = 0; | |
2301 | } | |
2302 | } | |
2303 | ||
2304 | #else | |
da19ab51 | 2305 | |
3f029d3c GH |
2306 | static inline void post_schedule(struct rq *rq) |
2307 | { | |
1da177e4 LT |
2308 | } |
2309 | ||
3f029d3c GH |
2310 | #endif |
2311 | ||
1da177e4 LT |
2312 | /** |
2313 | * schedule_tail - first thing a freshly forked thread must call. | |
2314 | * @prev: the thread we just switched away from. | |
2315 | */ | |
722a9f92 | 2316 | asmlinkage __visible void schedule_tail(struct task_struct *prev) |
1da177e4 LT |
2317 | __releases(rq->lock) |
2318 | { | |
1a43a14a | 2319 | struct rq *rq; |
da19ab51 | 2320 | |
1a43a14a ON |
2321 | /* finish_task_switch() drops rq->lock and enables preemtion */ |
2322 | preempt_disable(); | |
dfa50b60 | 2323 | rq = finish_task_switch(prev); |
3f029d3c | 2324 | post_schedule(rq); |
1a43a14a | 2325 | preempt_enable(); |
70b97a7f | 2326 | |
1da177e4 | 2327 | if (current->set_child_tid) |
b488893a | 2328 | put_user(task_pid_vnr(current), current->set_child_tid); |
1da177e4 LT |
2329 | } |
2330 | ||
2331 | /* | |
dfa50b60 | 2332 | * context_switch - switch to the new MM and the new thread's register state. |
1da177e4 | 2333 | */ |
dfa50b60 | 2334 | static inline struct rq * |
70b97a7f | 2335 | context_switch(struct rq *rq, struct task_struct *prev, |
36c8b586 | 2336 | struct task_struct *next) |
1da177e4 | 2337 | { |
dd41f596 | 2338 | struct mm_struct *mm, *oldmm; |
1da177e4 | 2339 | |
e107be36 | 2340 | prepare_task_switch(rq, prev, next); |
fe4b04fa | 2341 | |
dd41f596 IM |
2342 | mm = next->mm; |
2343 | oldmm = prev->active_mm; | |
9226d125 ZA |
2344 | /* |
2345 | * For paravirt, this is coupled with an exit in switch_to to | |
2346 | * combine the page table reload and the switch backend into | |
2347 | * one hypercall. | |
2348 | */ | |
224101ed | 2349 | arch_start_context_switch(prev); |
9226d125 | 2350 | |
31915ab4 | 2351 | if (!mm) { |
1da177e4 LT |
2352 | next->active_mm = oldmm; |
2353 | atomic_inc(&oldmm->mm_count); | |
2354 | enter_lazy_tlb(oldmm, next); | |
2355 | } else | |
2356 | switch_mm(oldmm, mm, next); | |
2357 | ||
31915ab4 | 2358 | if (!prev->mm) { |
1da177e4 | 2359 | prev->active_mm = NULL; |
1da177e4 LT |
2360 | rq->prev_mm = oldmm; |
2361 | } | |
3a5f5e48 IM |
2362 | /* |
2363 | * Since the runqueue lock will be released by the next | |
2364 | * task (which is an invalid locking op but in the case | |
2365 | * of the scheduler it's an obvious special-case), so we | |
2366 | * do an early lockdep release here: | |
2367 | */ | |
8a25d5de | 2368 | spin_release(&rq->lock.dep_map, 1, _THIS_IP_); |
1da177e4 | 2369 | |
91d1aa43 | 2370 | context_tracking_task_switch(prev, next); |
1da177e4 LT |
2371 | /* Here we just switch the register state and the stack. */ |
2372 | switch_to(prev, next, prev); | |
dd41f596 | 2373 | barrier(); |
dfa50b60 ON |
2374 | |
2375 | return finish_task_switch(prev); | |
1da177e4 LT |
2376 | } |
2377 | ||
2378 | /* | |
1c3e8264 | 2379 | * nr_running and nr_context_switches: |
1da177e4 LT |
2380 | * |
2381 | * externally visible scheduler statistics: current number of runnable | |
1c3e8264 | 2382 | * threads, total number of context switches performed since bootup. |
1da177e4 LT |
2383 | */ |
2384 | unsigned long nr_running(void) | |
2385 | { | |
2386 | unsigned long i, sum = 0; | |
2387 | ||
2388 | for_each_online_cpu(i) | |
2389 | sum += cpu_rq(i)->nr_running; | |
2390 | ||
2391 | return sum; | |
f711f609 | 2392 | } |
1da177e4 | 2393 | |
2ee507c4 TC |
2394 | /* |
2395 | * Check if only the current task is running on the cpu. | |
2396 | */ | |
2397 | bool single_task_running(void) | |
2398 | { | |
2399 | if (cpu_rq(smp_processor_id())->nr_running == 1) | |
2400 | return true; | |
2401 | else | |
2402 | return false; | |
2403 | } | |
2404 | EXPORT_SYMBOL(single_task_running); | |
2405 | ||
1da177e4 | 2406 | unsigned long long nr_context_switches(void) |
46cb4b7c | 2407 | { |
cc94abfc SR |
2408 | int i; |
2409 | unsigned long long sum = 0; | |
46cb4b7c | 2410 | |
0a945022 | 2411 | for_each_possible_cpu(i) |
1da177e4 | 2412 | sum += cpu_rq(i)->nr_switches; |
46cb4b7c | 2413 | |
1da177e4 LT |
2414 | return sum; |
2415 | } | |
483b4ee6 | 2416 | |
1da177e4 LT |
2417 | unsigned long nr_iowait(void) |
2418 | { | |
2419 | unsigned long i, sum = 0; | |
483b4ee6 | 2420 | |
0a945022 | 2421 | for_each_possible_cpu(i) |
1da177e4 | 2422 | sum += atomic_read(&cpu_rq(i)->nr_iowait); |
46cb4b7c | 2423 | |
1da177e4 LT |
2424 | return sum; |
2425 | } | |
483b4ee6 | 2426 | |
8c215bd3 | 2427 | unsigned long nr_iowait_cpu(int cpu) |
69d25870 | 2428 | { |
8c215bd3 | 2429 | struct rq *this = cpu_rq(cpu); |
69d25870 AV |
2430 | return atomic_read(&this->nr_iowait); |
2431 | } | |
46cb4b7c | 2432 | |
372ba8cb MG |
2433 | void get_iowait_load(unsigned long *nr_waiters, unsigned long *load) |
2434 | { | |
2435 | struct rq *this = this_rq(); | |
2436 | *nr_waiters = atomic_read(&this->nr_iowait); | |
2437 | *load = this->cpu_load[0]; | |
2438 | } | |
2439 | ||
dd41f596 | 2440 | #ifdef CONFIG_SMP |
8a0be9ef | 2441 | |
46cb4b7c | 2442 | /* |
38022906 PZ |
2443 | * sched_exec - execve() is a valuable balancing opportunity, because at |
2444 | * this point the task has the smallest effective memory and cache footprint. | |
46cb4b7c | 2445 | */ |
38022906 | 2446 | void sched_exec(void) |
46cb4b7c | 2447 | { |
38022906 | 2448 | struct task_struct *p = current; |
1da177e4 | 2449 | unsigned long flags; |
0017d735 | 2450 | int dest_cpu; |
46cb4b7c | 2451 | |
8f42ced9 | 2452 | raw_spin_lock_irqsave(&p->pi_lock, flags); |
ac66f547 | 2453 | dest_cpu = p->sched_class->select_task_rq(p, task_cpu(p), SD_BALANCE_EXEC, 0); |
0017d735 PZ |
2454 | if (dest_cpu == smp_processor_id()) |
2455 | goto unlock; | |
38022906 | 2456 | |
8f42ced9 | 2457 | if (likely(cpu_active(dest_cpu))) { |
969c7921 | 2458 | struct migration_arg arg = { p, dest_cpu }; |
46cb4b7c | 2459 | |
8f42ced9 PZ |
2460 | raw_spin_unlock_irqrestore(&p->pi_lock, flags); |
2461 | stop_one_cpu(task_cpu(p), migration_cpu_stop, &arg); | |
1da177e4 LT |
2462 | return; |
2463 | } | |
0017d735 | 2464 | unlock: |
8f42ced9 | 2465 | raw_spin_unlock_irqrestore(&p->pi_lock, flags); |
1da177e4 | 2466 | } |
dd41f596 | 2467 | |
1da177e4 LT |
2468 | #endif |
2469 | ||
1da177e4 | 2470 | DEFINE_PER_CPU(struct kernel_stat, kstat); |
3292beb3 | 2471 | DEFINE_PER_CPU(struct kernel_cpustat, kernel_cpustat); |
1da177e4 LT |
2472 | |
2473 | EXPORT_PER_CPU_SYMBOL(kstat); | |
3292beb3 | 2474 | EXPORT_PER_CPU_SYMBOL(kernel_cpustat); |
1da177e4 | 2475 | |
c5f8d995 HS |
2476 | /* |
2477 | * Return accounted runtime for the task. | |
2478 | * In case the task is currently running, return the runtime plus current's | |
2479 | * pending runtime that have not been accounted yet. | |
2480 | */ | |
2481 | unsigned long long task_sched_runtime(struct task_struct *p) | |
2482 | { | |
2483 | unsigned long flags; | |
2484 | struct rq *rq; | |
6e998916 | 2485 | u64 ns; |
c5f8d995 | 2486 | |
911b2898 PZ |
2487 | #if defined(CONFIG_64BIT) && defined(CONFIG_SMP) |
2488 | /* | |
2489 | * 64-bit doesn't need locks to atomically read a 64bit value. | |
2490 | * So we have a optimization chance when the task's delta_exec is 0. | |
2491 | * Reading ->on_cpu is racy, but this is ok. | |
2492 | * | |
2493 | * If we race with it leaving cpu, we'll take a lock. So we're correct. | |
2494 | * If we race with it entering cpu, unaccounted time is 0. This is | |
2495 | * indistinguishable from the read occurring a few cycles earlier. | |
4036ac15 MG |
2496 | * If we see ->on_cpu without ->on_rq, the task is leaving, and has |
2497 | * been accounted, so we're correct here as well. | |
911b2898 | 2498 | */ |
da0c1e65 | 2499 | if (!p->on_cpu || !task_on_rq_queued(p)) |
911b2898 PZ |
2500 | return p->se.sum_exec_runtime; |
2501 | #endif | |
2502 | ||
c5f8d995 | 2503 | rq = task_rq_lock(p, &flags); |
6e998916 SG |
2504 | /* |
2505 | * Must be ->curr _and_ ->on_rq. If dequeued, we would | |
2506 | * project cycles that may never be accounted to this | |
2507 | * thread, breaking clock_gettime(). | |
2508 | */ | |
2509 | if (task_current(rq, p) && task_on_rq_queued(p)) { | |
2510 | update_rq_clock(rq); | |
2511 | p->sched_class->update_curr(rq); | |
2512 | } | |
2513 | ns = p->se.sum_exec_runtime; | |
0122ec5b | 2514 | task_rq_unlock(rq, p, &flags); |
c5f8d995 HS |
2515 | |
2516 | return ns; | |
2517 | } | |
48f24c4d | 2518 | |
7835b98b CL |
2519 | /* |
2520 | * This function gets called by the timer code, with HZ frequency. | |
2521 | * We call it with interrupts disabled. | |
7835b98b CL |
2522 | */ |
2523 | void scheduler_tick(void) | |
2524 | { | |
7835b98b CL |
2525 | int cpu = smp_processor_id(); |
2526 | struct rq *rq = cpu_rq(cpu); | |
dd41f596 | 2527 | struct task_struct *curr = rq->curr; |
3e51f33f PZ |
2528 | |
2529 | sched_clock_tick(); | |
dd41f596 | 2530 | |
05fa785c | 2531 | raw_spin_lock(&rq->lock); |
3e51f33f | 2532 | update_rq_clock(rq); |
fa85ae24 | 2533 | curr->sched_class->task_tick(rq, curr, 0); |
83dfd523 | 2534 | update_cpu_load_active(rq); |
05fa785c | 2535 | raw_spin_unlock(&rq->lock); |
7835b98b | 2536 | |
e9d2b064 | 2537 | perf_event_task_tick(); |
e220d2dc | 2538 | |
e418e1c2 | 2539 | #ifdef CONFIG_SMP |
6eb57e0d | 2540 | rq->idle_balance = idle_cpu(cpu); |
7caff66f | 2541 | trigger_load_balance(rq); |
e418e1c2 | 2542 | #endif |
265f22a9 | 2543 | rq_last_tick_reset(rq); |
1da177e4 LT |
2544 | } |
2545 | ||
265f22a9 FW |
2546 | #ifdef CONFIG_NO_HZ_FULL |
2547 | /** | |
2548 | * scheduler_tick_max_deferment | |
2549 | * | |
2550 | * Keep at least one tick per second when a single | |
2551 | * active task is running because the scheduler doesn't | |
2552 | * yet completely support full dynticks environment. | |
2553 | * | |
2554 | * This makes sure that uptime, CFS vruntime, load | |
2555 | * balancing, etc... continue to move forward, even | |
2556 | * with a very low granularity. | |
e69f6186 YB |
2557 | * |
2558 | * Return: Maximum deferment in nanoseconds. | |
265f22a9 FW |
2559 | */ |
2560 | u64 scheduler_tick_max_deferment(void) | |
2561 | { | |
2562 | struct rq *rq = this_rq(); | |
2563 | unsigned long next, now = ACCESS_ONCE(jiffies); | |
2564 | ||
2565 | next = rq->last_sched_tick + HZ; | |
2566 | ||
2567 | if (time_before_eq(next, now)) | |
2568 | return 0; | |
2569 | ||
8fe8ff09 | 2570 | return jiffies_to_nsecs(next - now); |
1da177e4 | 2571 | } |
265f22a9 | 2572 | #endif |
1da177e4 | 2573 | |
132380a0 | 2574 | notrace unsigned long get_parent_ip(unsigned long addr) |
6cd8a4bb SR |
2575 | { |
2576 | if (in_lock_functions(addr)) { | |
2577 | addr = CALLER_ADDR2; | |
2578 | if (in_lock_functions(addr)) | |
2579 | addr = CALLER_ADDR3; | |
2580 | } | |
2581 | return addr; | |
2582 | } | |
1da177e4 | 2583 | |
7e49fcce SR |
2584 | #if defined(CONFIG_PREEMPT) && (defined(CONFIG_DEBUG_PREEMPT) || \ |
2585 | defined(CONFIG_PREEMPT_TRACER)) | |
2586 | ||
edafe3a5 | 2587 | void preempt_count_add(int val) |
1da177e4 | 2588 | { |
6cd8a4bb | 2589 | #ifdef CONFIG_DEBUG_PREEMPT |
1da177e4 LT |
2590 | /* |
2591 | * Underflow? | |
2592 | */ | |
9a11b49a IM |
2593 | if (DEBUG_LOCKS_WARN_ON((preempt_count() < 0))) |
2594 | return; | |
6cd8a4bb | 2595 | #endif |
bdb43806 | 2596 | __preempt_count_add(val); |
6cd8a4bb | 2597 | #ifdef CONFIG_DEBUG_PREEMPT |
1da177e4 LT |
2598 | /* |
2599 | * Spinlock count overflowing soon? | |
2600 | */ | |
33859f7f MOS |
2601 | DEBUG_LOCKS_WARN_ON((preempt_count() & PREEMPT_MASK) >= |
2602 | PREEMPT_MASK - 10); | |
6cd8a4bb | 2603 | #endif |
8f47b187 TG |
2604 | if (preempt_count() == val) { |
2605 | unsigned long ip = get_parent_ip(CALLER_ADDR1); | |
2606 | #ifdef CONFIG_DEBUG_PREEMPT | |
2607 | current->preempt_disable_ip = ip; | |
2608 | #endif | |
2609 | trace_preempt_off(CALLER_ADDR0, ip); | |
2610 | } | |
1da177e4 | 2611 | } |
bdb43806 | 2612 | EXPORT_SYMBOL(preempt_count_add); |
edafe3a5 | 2613 | NOKPROBE_SYMBOL(preempt_count_add); |
1da177e4 | 2614 | |
edafe3a5 | 2615 | void preempt_count_sub(int val) |
1da177e4 | 2616 | { |
6cd8a4bb | 2617 | #ifdef CONFIG_DEBUG_PREEMPT |
1da177e4 LT |
2618 | /* |
2619 | * Underflow? | |
2620 | */ | |
01e3eb82 | 2621 | if (DEBUG_LOCKS_WARN_ON(val > preempt_count())) |
9a11b49a | 2622 | return; |
1da177e4 LT |
2623 | /* |
2624 | * Is the spinlock portion underflowing? | |
2625 | */ | |
9a11b49a IM |
2626 | if (DEBUG_LOCKS_WARN_ON((val < PREEMPT_MASK) && |
2627 | !(preempt_count() & PREEMPT_MASK))) | |
2628 | return; | |
6cd8a4bb | 2629 | #endif |
9a11b49a | 2630 | |
6cd8a4bb SR |
2631 | if (preempt_count() == val) |
2632 | trace_preempt_on(CALLER_ADDR0, get_parent_ip(CALLER_ADDR1)); | |
bdb43806 | 2633 | __preempt_count_sub(val); |
1da177e4 | 2634 | } |
bdb43806 | 2635 | EXPORT_SYMBOL(preempt_count_sub); |
edafe3a5 | 2636 | NOKPROBE_SYMBOL(preempt_count_sub); |
1da177e4 LT |
2637 | |
2638 | #endif | |
2639 | ||
2640 | /* | |
dd41f596 | 2641 | * Print scheduling while atomic bug: |
1da177e4 | 2642 | */ |
dd41f596 | 2643 | static noinline void __schedule_bug(struct task_struct *prev) |
1da177e4 | 2644 | { |
664dfa65 DJ |
2645 | if (oops_in_progress) |
2646 | return; | |
2647 | ||
3df0fc5b PZ |
2648 | printk(KERN_ERR "BUG: scheduling while atomic: %s/%d/0x%08x\n", |
2649 | prev->comm, prev->pid, preempt_count()); | |
838225b4 | 2650 | |
dd41f596 | 2651 | debug_show_held_locks(prev); |
e21f5b15 | 2652 | print_modules(); |
dd41f596 IM |
2653 | if (irqs_disabled()) |
2654 | print_irqtrace_events(prev); | |
8f47b187 TG |
2655 | #ifdef CONFIG_DEBUG_PREEMPT |
2656 | if (in_atomic_preempt_off()) { | |
2657 | pr_err("Preemption disabled at:"); | |
2658 | print_ip_sym(current->preempt_disable_ip); | |
2659 | pr_cont("\n"); | |
2660 | } | |
2661 | #endif | |
6135fc1e | 2662 | dump_stack(); |
373d4d09 | 2663 | add_taint(TAINT_WARN, LOCKDEP_STILL_OK); |
dd41f596 | 2664 | } |
1da177e4 | 2665 | |
dd41f596 IM |
2666 | /* |
2667 | * Various schedule()-time debugging checks and statistics: | |
2668 | */ | |
2669 | static inline void schedule_debug(struct task_struct *prev) | |
2670 | { | |
0d9e2632 AT |
2671 | #ifdef CONFIG_SCHED_STACK_END_CHECK |
2672 | BUG_ON(unlikely(task_stack_end_corrupted(prev))); | |
2673 | #endif | |
1da177e4 | 2674 | /* |
41a2d6cf | 2675 | * Test if we are atomic. Since do_exit() needs to call into |
192301e7 ON |
2676 | * schedule() atomically, we ignore that path. Otherwise whine |
2677 | * if we are scheduling when we should not. | |
1da177e4 | 2678 | */ |
192301e7 | 2679 | if (unlikely(in_atomic_preempt_off() && prev->state != TASK_DEAD)) |
dd41f596 | 2680 | __schedule_bug(prev); |
b3fbab05 | 2681 | rcu_sleep_check(); |
dd41f596 | 2682 | |
1da177e4 LT |
2683 | profile_hit(SCHED_PROFILING, __builtin_return_address(0)); |
2684 | ||
2d72376b | 2685 | schedstat_inc(this_rq(), sched_count); |
dd41f596 IM |
2686 | } |
2687 | ||
2688 | /* | |
2689 | * Pick up the highest-prio task: | |
2690 | */ | |
2691 | static inline struct task_struct * | |
606dba2e | 2692 | pick_next_task(struct rq *rq, struct task_struct *prev) |
dd41f596 | 2693 | { |
37e117c0 | 2694 | const struct sched_class *class = &fair_sched_class; |
dd41f596 | 2695 | struct task_struct *p; |
1da177e4 LT |
2696 | |
2697 | /* | |
dd41f596 IM |
2698 | * Optimization: we know that if all tasks are in |
2699 | * the fair class we can call that function directly: | |
1da177e4 | 2700 | */ |
37e117c0 | 2701 | if (likely(prev->sched_class == class && |
38033c37 | 2702 | rq->nr_running == rq->cfs.h_nr_running)) { |
606dba2e | 2703 | p = fair_sched_class.pick_next_task(rq, prev); |
6ccdc84b PZ |
2704 | if (unlikely(p == RETRY_TASK)) |
2705 | goto again; | |
2706 | ||
2707 | /* assumes fair_sched_class->next == idle_sched_class */ | |
2708 | if (unlikely(!p)) | |
2709 | p = idle_sched_class.pick_next_task(rq, prev); | |
2710 | ||
2711 | return p; | |
1da177e4 LT |
2712 | } |
2713 | ||
37e117c0 | 2714 | again: |
34f971f6 | 2715 | for_each_class(class) { |
606dba2e | 2716 | p = class->pick_next_task(rq, prev); |
37e117c0 PZ |
2717 | if (p) { |
2718 | if (unlikely(p == RETRY_TASK)) | |
2719 | goto again; | |
dd41f596 | 2720 | return p; |
37e117c0 | 2721 | } |
dd41f596 | 2722 | } |
34f971f6 PZ |
2723 | |
2724 | BUG(); /* the idle class will always have a runnable task */ | |
dd41f596 | 2725 | } |
1da177e4 | 2726 | |
dd41f596 | 2727 | /* |
c259e01a | 2728 | * __schedule() is the main scheduler function. |
edde96ea PE |
2729 | * |
2730 | * The main means of driving the scheduler and thus entering this function are: | |
2731 | * | |
2732 | * 1. Explicit blocking: mutex, semaphore, waitqueue, etc. | |
2733 | * | |
2734 | * 2. TIF_NEED_RESCHED flag is checked on interrupt and userspace return | |
2735 | * paths. For example, see arch/x86/entry_64.S. | |
2736 | * | |
2737 | * To drive preemption between tasks, the scheduler sets the flag in timer | |
2738 | * interrupt handler scheduler_tick(). | |
2739 | * | |
2740 | * 3. Wakeups don't really cause entry into schedule(). They add a | |
2741 | * task to the run-queue and that's it. | |
2742 | * | |
2743 | * Now, if the new task added to the run-queue preempts the current | |
2744 | * task, then the wakeup sets TIF_NEED_RESCHED and schedule() gets | |
2745 | * called on the nearest possible occasion: | |
2746 | * | |
2747 | * - If the kernel is preemptible (CONFIG_PREEMPT=y): | |
2748 | * | |
2749 | * - in syscall or exception context, at the next outmost | |
2750 | * preempt_enable(). (this might be as soon as the wake_up()'s | |
2751 | * spin_unlock()!) | |
2752 | * | |
2753 | * - in IRQ context, return from interrupt-handler to | |
2754 | * preemptible context | |
2755 | * | |
2756 | * - If the kernel is not preemptible (CONFIG_PREEMPT is not set) | |
2757 | * then at the next: | |
2758 | * | |
2759 | * - cond_resched() call | |
2760 | * - explicit schedule() call | |
2761 | * - return from syscall or exception to user-space | |
2762 | * - return from interrupt-handler to user-space | |
dd41f596 | 2763 | */ |
c259e01a | 2764 | static void __sched __schedule(void) |
dd41f596 IM |
2765 | { |
2766 | struct task_struct *prev, *next; | |
67ca7bde | 2767 | unsigned long *switch_count; |
dd41f596 | 2768 | struct rq *rq; |
31656519 | 2769 | int cpu; |
dd41f596 | 2770 | |
ff743345 PZ |
2771 | need_resched: |
2772 | preempt_disable(); | |
dd41f596 IM |
2773 | cpu = smp_processor_id(); |
2774 | rq = cpu_rq(cpu); | |
38200cf2 | 2775 | rcu_note_context_switch(); |
dd41f596 | 2776 | prev = rq->curr; |
dd41f596 | 2777 | |
dd41f596 | 2778 | schedule_debug(prev); |
1da177e4 | 2779 | |
31656519 | 2780 | if (sched_feat(HRTICK)) |
f333fdc9 | 2781 | hrtick_clear(rq); |
8f4d37ec | 2782 | |
e0acd0a6 ON |
2783 | /* |
2784 | * Make sure that signal_pending_state()->signal_pending() below | |
2785 | * can't be reordered with __set_current_state(TASK_INTERRUPTIBLE) | |
2786 | * done by the caller to avoid the race with signal_wake_up(). | |
2787 | */ | |
2788 | smp_mb__before_spinlock(); | |
05fa785c | 2789 | raw_spin_lock_irq(&rq->lock); |
1da177e4 | 2790 | |
9edfbfed PZ |
2791 | rq->clock_skip_update <<= 1; /* promote REQ to ACT */ |
2792 | ||
246d86b5 | 2793 | switch_count = &prev->nivcsw; |
1da177e4 | 2794 | if (prev->state && !(preempt_count() & PREEMPT_ACTIVE)) { |
21aa9af0 | 2795 | if (unlikely(signal_pending_state(prev->state, prev))) { |
1da177e4 | 2796 | prev->state = TASK_RUNNING; |
21aa9af0 | 2797 | } else { |
2acca55e PZ |
2798 | deactivate_task(rq, prev, DEQUEUE_SLEEP); |
2799 | prev->on_rq = 0; | |
2800 | ||
21aa9af0 | 2801 | /* |
2acca55e PZ |
2802 | * If a worker went to sleep, notify and ask workqueue |
2803 | * whether it wants to wake up a task to maintain | |
2804 | * concurrency. | |
21aa9af0 TH |
2805 | */ |
2806 | if (prev->flags & PF_WQ_WORKER) { | |
2807 | struct task_struct *to_wakeup; | |
2808 | ||
2809 | to_wakeup = wq_worker_sleeping(prev, cpu); | |
2810 | if (to_wakeup) | |
2811 | try_to_wake_up_local(to_wakeup); | |
2812 | } | |
21aa9af0 | 2813 | } |
dd41f596 | 2814 | switch_count = &prev->nvcsw; |
1da177e4 LT |
2815 | } |
2816 | ||
9edfbfed | 2817 | if (task_on_rq_queued(prev)) |
606dba2e PZ |
2818 | update_rq_clock(rq); |
2819 | ||
2820 | next = pick_next_task(rq, prev); | |
f26f9aff | 2821 | clear_tsk_need_resched(prev); |
f27dde8d | 2822 | clear_preempt_need_resched(); |
9edfbfed | 2823 | rq->clock_skip_update = 0; |
1da177e4 | 2824 | |
1da177e4 | 2825 | if (likely(prev != next)) { |
1da177e4 LT |
2826 | rq->nr_switches++; |
2827 | rq->curr = next; | |
2828 | ++*switch_count; | |
2829 | ||
dfa50b60 ON |
2830 | rq = context_switch(rq, prev, next); /* unlocks the rq */ |
2831 | cpu = cpu_of(rq); | |
1da177e4 | 2832 | } else |
05fa785c | 2833 | raw_spin_unlock_irq(&rq->lock); |
1da177e4 | 2834 | |
3f029d3c | 2835 | post_schedule(rq); |
1da177e4 | 2836 | |
ba74c144 | 2837 | sched_preempt_enable_no_resched(); |
ff743345 | 2838 | if (need_resched()) |
1da177e4 LT |
2839 | goto need_resched; |
2840 | } | |
c259e01a | 2841 | |
9c40cef2 TG |
2842 | static inline void sched_submit_work(struct task_struct *tsk) |
2843 | { | |
3c7d5184 | 2844 | if (!tsk->state || tsk_is_pi_blocked(tsk)) |
9c40cef2 TG |
2845 | return; |
2846 | /* | |
2847 | * If we are going to sleep and we have plugged IO queued, | |
2848 | * make sure to submit it to avoid deadlocks. | |
2849 | */ | |
2850 | if (blk_needs_flush_plug(tsk)) | |
2851 | blk_schedule_flush_plug(tsk); | |
2852 | } | |
2853 | ||
722a9f92 | 2854 | asmlinkage __visible void __sched schedule(void) |
c259e01a | 2855 | { |
9c40cef2 TG |
2856 | struct task_struct *tsk = current; |
2857 | ||
2858 | sched_submit_work(tsk); | |
c259e01a TG |
2859 | __schedule(); |
2860 | } | |
1da177e4 LT |
2861 | EXPORT_SYMBOL(schedule); |
2862 | ||
91d1aa43 | 2863 | #ifdef CONFIG_CONTEXT_TRACKING |
722a9f92 | 2864 | asmlinkage __visible void __sched schedule_user(void) |
20ab65e3 FW |
2865 | { |
2866 | /* | |
2867 | * If we come here after a random call to set_need_resched(), | |
2868 | * or we have been woken up remotely but the IPI has not yet arrived, | |
2869 | * we haven't yet exited the RCU idle mode. Do it here manually until | |
2870 | * we find a better solution. | |
7cc78f8f AL |
2871 | * |
2872 | * NB: There are buggy callers of this function. Ideally we | |
2873 | * should warn if prev_state != IN_USER, but that will trigger | |
2874 | * too frequently to make sense yet. | |
20ab65e3 | 2875 | */ |
7cc78f8f | 2876 | enum ctx_state prev_state = exception_enter(); |
20ab65e3 | 2877 | schedule(); |
7cc78f8f | 2878 | exception_exit(prev_state); |
20ab65e3 FW |
2879 | } |
2880 | #endif | |
2881 | ||
c5491ea7 TG |
2882 | /** |
2883 | * schedule_preempt_disabled - called with preemption disabled | |
2884 | * | |
2885 | * Returns with preemption disabled. Note: preempt_count must be 1 | |
2886 | */ | |
2887 | void __sched schedule_preempt_disabled(void) | |
2888 | { | |
ba74c144 | 2889 | sched_preempt_enable_no_resched(); |
c5491ea7 TG |
2890 | schedule(); |
2891 | preempt_disable(); | |
2892 | } | |
2893 | ||
a18b5d01 FW |
2894 | static void preempt_schedule_common(void) |
2895 | { | |
2896 | do { | |
2897 | __preempt_count_add(PREEMPT_ACTIVE); | |
2898 | __schedule(); | |
2899 | __preempt_count_sub(PREEMPT_ACTIVE); | |
2900 | ||
2901 | /* | |
2902 | * Check again in case we missed a preemption opportunity | |
2903 | * between schedule and now. | |
2904 | */ | |
2905 | barrier(); | |
2906 | } while (need_resched()); | |
2907 | } | |
2908 | ||
1da177e4 LT |
2909 | #ifdef CONFIG_PREEMPT |
2910 | /* | |
2ed6e34f | 2911 | * this is the entry point to schedule() from in-kernel preemption |
41a2d6cf | 2912 | * off of preempt_enable. Kernel preemptions off return from interrupt |
1da177e4 LT |
2913 | * occur there and call schedule directly. |
2914 | */ | |
722a9f92 | 2915 | asmlinkage __visible void __sched notrace preempt_schedule(void) |
1da177e4 | 2916 | { |
1da177e4 LT |
2917 | /* |
2918 | * If there is a non-zero preempt_count or interrupts are disabled, | |
41a2d6cf | 2919 | * we do not want to preempt the current task. Just return.. |
1da177e4 | 2920 | */ |
fbb00b56 | 2921 | if (likely(!preemptible())) |
1da177e4 LT |
2922 | return; |
2923 | ||
a18b5d01 | 2924 | preempt_schedule_common(); |
1da177e4 | 2925 | } |
376e2424 | 2926 | NOKPROBE_SYMBOL(preempt_schedule); |
1da177e4 | 2927 | EXPORT_SYMBOL(preempt_schedule); |
009f60e2 ON |
2928 | |
2929 | #ifdef CONFIG_CONTEXT_TRACKING | |
2930 | /** | |
2931 | * preempt_schedule_context - preempt_schedule called by tracing | |
2932 | * | |
2933 | * The tracing infrastructure uses preempt_enable_notrace to prevent | |
2934 | * recursion and tracing preempt enabling caused by the tracing | |
2935 | * infrastructure itself. But as tracing can happen in areas coming | |
2936 | * from userspace or just about to enter userspace, a preempt enable | |
2937 | * can occur before user_exit() is called. This will cause the scheduler | |
2938 | * to be called when the system is still in usermode. | |
2939 | * | |
2940 | * To prevent this, the preempt_enable_notrace will use this function | |
2941 | * instead of preempt_schedule() to exit user context if needed before | |
2942 | * calling the scheduler. | |
2943 | */ | |
2944 | asmlinkage __visible void __sched notrace preempt_schedule_context(void) | |
2945 | { | |
2946 | enum ctx_state prev_ctx; | |
2947 | ||
2948 | if (likely(!preemptible())) | |
2949 | return; | |
2950 | ||
2951 | do { | |
2952 | __preempt_count_add(PREEMPT_ACTIVE); | |
2953 | /* | |
2954 | * Needs preempt disabled in case user_exit() is traced | |
2955 | * and the tracer calls preempt_enable_notrace() causing | |
2956 | * an infinite recursion. | |
2957 | */ | |
2958 | prev_ctx = exception_enter(); | |
2959 | __schedule(); | |
2960 | exception_exit(prev_ctx); | |
2961 | ||
2962 | __preempt_count_sub(PREEMPT_ACTIVE); | |
2963 | barrier(); | |
2964 | } while (need_resched()); | |
2965 | } | |
2966 | EXPORT_SYMBOL_GPL(preempt_schedule_context); | |
2967 | #endif /* CONFIG_CONTEXT_TRACKING */ | |
2968 | ||
32e475d7 | 2969 | #endif /* CONFIG_PREEMPT */ |
1da177e4 LT |
2970 | |
2971 | /* | |
2ed6e34f | 2972 | * this is the entry point to schedule() from kernel preemption |
1da177e4 LT |
2973 | * off of irq context. |
2974 | * Note, that this is called and return with irqs disabled. This will | |
2975 | * protect us against recursive calling from irq. | |
2976 | */ | |
722a9f92 | 2977 | asmlinkage __visible void __sched preempt_schedule_irq(void) |
1da177e4 | 2978 | { |
b22366cd | 2979 | enum ctx_state prev_state; |
6478d880 | 2980 | |
2ed6e34f | 2981 | /* Catch callers which need to be fixed */ |
f27dde8d | 2982 | BUG_ON(preempt_count() || !irqs_disabled()); |
1da177e4 | 2983 | |
b22366cd FW |
2984 | prev_state = exception_enter(); |
2985 | ||
3a5c359a | 2986 | do { |
bdb43806 | 2987 | __preempt_count_add(PREEMPT_ACTIVE); |
3a5c359a | 2988 | local_irq_enable(); |
c259e01a | 2989 | __schedule(); |
3a5c359a | 2990 | local_irq_disable(); |
bdb43806 | 2991 | __preempt_count_sub(PREEMPT_ACTIVE); |
1da177e4 | 2992 | |
3a5c359a AK |
2993 | /* |
2994 | * Check again in case we missed a preemption opportunity | |
2995 | * between schedule and now. | |
2996 | */ | |
2997 | barrier(); | |
5ed0cec0 | 2998 | } while (need_resched()); |
b22366cd FW |
2999 | |
3000 | exception_exit(prev_state); | |
1da177e4 LT |
3001 | } |
3002 | ||
63859d4f | 3003 | int default_wake_function(wait_queue_t *curr, unsigned mode, int wake_flags, |
95cdf3b7 | 3004 | void *key) |
1da177e4 | 3005 | { |
63859d4f | 3006 | return try_to_wake_up(curr->private, mode, wake_flags); |
1da177e4 | 3007 | } |
1da177e4 LT |
3008 | EXPORT_SYMBOL(default_wake_function); |
3009 | ||
b29739f9 IM |
3010 | #ifdef CONFIG_RT_MUTEXES |
3011 | ||
3012 | /* | |
3013 | * rt_mutex_setprio - set the current priority of a task | |
3014 | * @p: task | |
3015 | * @prio: prio value (kernel-internal form) | |
3016 | * | |
3017 | * This function changes the 'effective' priority of a task. It does | |
3018 | * not touch ->normal_prio like __setscheduler(). | |
3019 | * | |
c365c292 TG |
3020 | * Used by the rt_mutex code to implement priority inheritance |
3021 | * logic. Call site only calls if the priority of the task changed. | |
b29739f9 | 3022 | */ |
36c8b586 | 3023 | void rt_mutex_setprio(struct task_struct *p, int prio) |
b29739f9 | 3024 | { |
da0c1e65 | 3025 | int oldprio, queued, running, enqueue_flag = 0; |
70b97a7f | 3026 | struct rq *rq; |
83ab0aa0 | 3027 | const struct sched_class *prev_class; |
b29739f9 | 3028 | |
aab03e05 | 3029 | BUG_ON(prio > MAX_PRIO); |
b29739f9 | 3030 | |
0122ec5b | 3031 | rq = __task_rq_lock(p); |
b29739f9 | 3032 | |
1c4dd99b TG |
3033 | /* |
3034 | * Idle task boosting is a nono in general. There is one | |
3035 | * exception, when PREEMPT_RT and NOHZ is active: | |
3036 | * | |
3037 | * The idle task calls get_next_timer_interrupt() and holds | |
3038 | * the timer wheel base->lock on the CPU and another CPU wants | |
3039 | * to access the timer (probably to cancel it). We can safely | |
3040 | * ignore the boosting request, as the idle CPU runs this code | |
3041 | * with interrupts disabled and will complete the lock | |
3042 | * protected section without being interrupted. So there is no | |
3043 | * real need to boost. | |
3044 | */ | |
3045 | if (unlikely(p == rq->idle)) { | |
3046 | WARN_ON(p != rq->curr); | |
3047 | WARN_ON(p->pi_blocked_on); | |
3048 | goto out_unlock; | |
3049 | } | |
3050 | ||
a8027073 | 3051 | trace_sched_pi_setprio(p, prio); |
d5f9f942 | 3052 | oldprio = p->prio; |
83ab0aa0 | 3053 | prev_class = p->sched_class; |
da0c1e65 | 3054 | queued = task_on_rq_queued(p); |
051a1d1a | 3055 | running = task_current(rq, p); |
da0c1e65 | 3056 | if (queued) |
69be72c1 | 3057 | dequeue_task(rq, p, 0); |
0e1f3483 | 3058 | if (running) |
f3cd1c4e | 3059 | put_prev_task(rq, p); |
dd41f596 | 3060 | |
2d3d891d DF |
3061 | /* |
3062 | * Boosting condition are: | |
3063 | * 1. -rt task is running and holds mutex A | |
3064 | * --> -dl task blocks on mutex A | |
3065 | * | |
3066 | * 2. -dl task is running and holds mutex A | |
3067 | * --> -dl task blocks on mutex A and could preempt the | |
3068 | * running task | |
3069 | */ | |
3070 | if (dl_prio(prio)) { | |
466af29b ON |
3071 | struct task_struct *pi_task = rt_mutex_get_top_task(p); |
3072 | if (!dl_prio(p->normal_prio) || | |
3073 | (pi_task && dl_entity_preempt(&pi_task->dl, &p->dl))) { | |
2d3d891d DF |
3074 | p->dl.dl_boosted = 1; |
3075 | p->dl.dl_throttled = 0; | |
3076 | enqueue_flag = ENQUEUE_REPLENISH; | |
3077 | } else | |
3078 | p->dl.dl_boosted = 0; | |
aab03e05 | 3079 | p->sched_class = &dl_sched_class; |
2d3d891d DF |
3080 | } else if (rt_prio(prio)) { |
3081 | if (dl_prio(oldprio)) | |
3082 | p->dl.dl_boosted = 0; | |
3083 | if (oldprio < prio) | |
3084 | enqueue_flag = ENQUEUE_HEAD; | |
dd41f596 | 3085 | p->sched_class = &rt_sched_class; |
2d3d891d DF |
3086 | } else { |
3087 | if (dl_prio(oldprio)) | |
3088 | p->dl.dl_boosted = 0; | |
dd41f596 | 3089 | p->sched_class = &fair_sched_class; |
2d3d891d | 3090 | } |
dd41f596 | 3091 | |
b29739f9 IM |
3092 | p->prio = prio; |
3093 | ||
0e1f3483 HS |
3094 | if (running) |
3095 | p->sched_class->set_curr_task(rq); | |
da0c1e65 | 3096 | if (queued) |
2d3d891d | 3097 | enqueue_task(rq, p, enqueue_flag); |
cb469845 | 3098 | |
da7a735e | 3099 | check_class_changed(rq, p, prev_class, oldprio); |
1c4dd99b | 3100 | out_unlock: |
0122ec5b | 3101 | __task_rq_unlock(rq); |
b29739f9 | 3102 | } |
b29739f9 | 3103 | #endif |
d50dde5a | 3104 | |
36c8b586 | 3105 | void set_user_nice(struct task_struct *p, long nice) |
1da177e4 | 3106 | { |
da0c1e65 | 3107 | int old_prio, delta, queued; |
1da177e4 | 3108 | unsigned long flags; |
70b97a7f | 3109 | struct rq *rq; |
1da177e4 | 3110 | |
75e45d51 | 3111 | if (task_nice(p) == nice || nice < MIN_NICE || nice > MAX_NICE) |
1da177e4 LT |
3112 | return; |
3113 | /* | |
3114 | * We have to be careful, if called from sys_setpriority(), | |
3115 | * the task might be in the middle of scheduling on another CPU. | |
3116 | */ | |
3117 | rq = task_rq_lock(p, &flags); | |
3118 | /* | |
3119 | * The RT priorities are set via sched_setscheduler(), but we still | |
3120 | * allow the 'normal' nice value to be set - but as expected | |
3121 | * it wont have any effect on scheduling until the task is | |
aab03e05 | 3122 | * SCHED_DEADLINE, SCHED_FIFO or SCHED_RR: |
1da177e4 | 3123 | */ |
aab03e05 | 3124 | if (task_has_dl_policy(p) || task_has_rt_policy(p)) { |
1da177e4 LT |
3125 | p->static_prio = NICE_TO_PRIO(nice); |
3126 | goto out_unlock; | |
3127 | } | |
da0c1e65 KT |
3128 | queued = task_on_rq_queued(p); |
3129 | if (queued) | |
69be72c1 | 3130 | dequeue_task(rq, p, 0); |
1da177e4 | 3131 | |
1da177e4 | 3132 | p->static_prio = NICE_TO_PRIO(nice); |
2dd73a4f | 3133 | set_load_weight(p); |
b29739f9 IM |
3134 | old_prio = p->prio; |
3135 | p->prio = effective_prio(p); | |
3136 | delta = p->prio - old_prio; | |
1da177e4 | 3137 | |
da0c1e65 | 3138 | if (queued) { |
371fd7e7 | 3139 | enqueue_task(rq, p, 0); |
1da177e4 | 3140 | /* |
d5f9f942 AM |
3141 | * If the task increased its priority or is running and |
3142 | * lowered its priority, then reschedule its CPU: | |
1da177e4 | 3143 | */ |
d5f9f942 | 3144 | if (delta < 0 || (delta > 0 && task_running(rq, p))) |
8875125e | 3145 | resched_curr(rq); |
1da177e4 LT |
3146 | } |
3147 | out_unlock: | |
0122ec5b | 3148 | task_rq_unlock(rq, p, &flags); |
1da177e4 | 3149 | } |
1da177e4 LT |
3150 | EXPORT_SYMBOL(set_user_nice); |
3151 | ||
e43379f1 MM |
3152 | /* |
3153 | * can_nice - check if a task can reduce its nice value | |
3154 | * @p: task | |
3155 | * @nice: nice value | |
3156 | */ | |
36c8b586 | 3157 | int can_nice(const struct task_struct *p, const int nice) |
e43379f1 | 3158 | { |
024f4747 | 3159 | /* convert nice value [19,-20] to rlimit style value [1,40] */ |
7aa2c016 | 3160 | int nice_rlim = nice_to_rlimit(nice); |
48f24c4d | 3161 | |
78d7d407 | 3162 | return (nice_rlim <= task_rlimit(p, RLIMIT_NICE) || |
e43379f1 MM |
3163 | capable(CAP_SYS_NICE)); |
3164 | } | |
3165 | ||
1da177e4 LT |
3166 | #ifdef __ARCH_WANT_SYS_NICE |
3167 | ||
3168 | /* | |
3169 | * sys_nice - change the priority of the current process. | |
3170 | * @increment: priority increment | |
3171 | * | |
3172 | * sys_setpriority is a more generic, but much slower function that | |
3173 | * does similar things. | |
3174 | */ | |
5add95d4 | 3175 | SYSCALL_DEFINE1(nice, int, increment) |
1da177e4 | 3176 | { |
48f24c4d | 3177 | long nice, retval; |
1da177e4 LT |
3178 | |
3179 | /* | |
3180 | * Setpriority might change our priority at the same moment. | |
3181 | * We don't have to worry. Conceptually one call occurs first | |
3182 | * and we have a single winner. | |
3183 | */ | |
a9467fa3 | 3184 | increment = clamp(increment, -NICE_WIDTH, NICE_WIDTH); |
d0ea0268 | 3185 | nice = task_nice(current) + increment; |
1da177e4 | 3186 | |
a9467fa3 | 3187 | nice = clamp_val(nice, MIN_NICE, MAX_NICE); |
e43379f1 MM |
3188 | if (increment < 0 && !can_nice(current, nice)) |
3189 | return -EPERM; | |
3190 | ||
1da177e4 LT |
3191 | retval = security_task_setnice(current, nice); |
3192 | if (retval) | |
3193 | return retval; | |
3194 | ||
3195 | set_user_nice(current, nice); | |
3196 | return 0; | |
3197 | } | |
3198 | ||
3199 | #endif | |
3200 | ||
3201 | /** | |
3202 | * task_prio - return the priority value of a given task. | |
3203 | * @p: the task in question. | |
3204 | * | |
e69f6186 | 3205 | * Return: The priority value as seen by users in /proc. |
1da177e4 LT |
3206 | * RT tasks are offset by -200. Normal tasks are centered |
3207 | * around 0, value goes from -16 to +15. | |
3208 | */ | |
36c8b586 | 3209 | int task_prio(const struct task_struct *p) |
1da177e4 LT |
3210 | { |
3211 | return p->prio - MAX_RT_PRIO; | |
3212 | } | |
3213 | ||
1da177e4 LT |
3214 | /** |
3215 | * idle_cpu - is a given cpu idle currently? | |
3216 | * @cpu: the processor in question. | |
e69f6186 YB |
3217 | * |
3218 | * Return: 1 if the CPU is currently idle. 0 otherwise. | |
1da177e4 LT |
3219 | */ |
3220 | int idle_cpu(int cpu) | |
3221 | { | |
908a3283 TG |
3222 | struct rq *rq = cpu_rq(cpu); |
3223 | ||
3224 | if (rq->curr != rq->idle) | |
3225 | return 0; | |
3226 | ||
3227 | if (rq->nr_running) | |
3228 | return 0; | |
3229 | ||
3230 | #ifdef CONFIG_SMP | |
3231 | if (!llist_empty(&rq->wake_list)) | |
3232 | return 0; | |
3233 | #endif | |
3234 | ||
3235 | return 1; | |
1da177e4 LT |
3236 | } |
3237 | ||
1da177e4 LT |
3238 | /** |
3239 | * idle_task - return the idle task for a given cpu. | |
3240 | * @cpu: the processor in question. | |
e69f6186 YB |
3241 | * |
3242 | * Return: The idle task for the cpu @cpu. | |
1da177e4 | 3243 | */ |
36c8b586 | 3244 | struct task_struct *idle_task(int cpu) |
1da177e4 LT |
3245 | { |
3246 | return cpu_rq(cpu)->idle; | |
3247 | } | |
3248 | ||
3249 | /** | |
3250 | * find_process_by_pid - find a process with a matching PID value. | |
3251 | * @pid: the pid in question. | |
e69f6186 YB |
3252 | * |
3253 | * The task of @pid, if found. %NULL otherwise. | |
1da177e4 | 3254 | */ |
a9957449 | 3255 | static struct task_struct *find_process_by_pid(pid_t pid) |
1da177e4 | 3256 | { |
228ebcbe | 3257 | return pid ? find_task_by_vpid(pid) : current; |
1da177e4 LT |
3258 | } |
3259 | ||
aab03e05 DF |
3260 | /* |
3261 | * This function initializes the sched_dl_entity of a newly becoming | |
3262 | * SCHED_DEADLINE task. | |
3263 | * | |
3264 | * Only the static values are considered here, the actual runtime and the | |
3265 | * absolute deadline will be properly calculated when the task is enqueued | |
3266 | * for the first time with its new policy. | |
3267 | */ | |
3268 | static void | |
3269 | __setparam_dl(struct task_struct *p, const struct sched_attr *attr) | |
3270 | { | |
3271 | struct sched_dl_entity *dl_se = &p->dl; | |
3272 | ||
aab03e05 DF |
3273 | dl_se->dl_runtime = attr->sched_runtime; |
3274 | dl_se->dl_deadline = attr->sched_deadline; | |
755378a4 | 3275 | dl_se->dl_period = attr->sched_period ?: dl_se->dl_deadline; |
aab03e05 | 3276 | dl_se->flags = attr->sched_flags; |
332ac17e | 3277 | dl_se->dl_bw = to_ratio(dl_se->dl_period, dl_se->dl_runtime); |
40767b0d PZ |
3278 | |
3279 | /* | |
3280 | * Changing the parameters of a task is 'tricky' and we're not doing | |
3281 | * the correct thing -- also see task_dead_dl() and switched_from_dl(). | |
3282 | * | |
3283 | * What we SHOULD do is delay the bandwidth release until the 0-lag | |
3284 | * point. This would include retaining the task_struct until that time | |
3285 | * and change dl_overflow() to not immediately decrement the current | |
3286 | * amount. | |
3287 | * | |
3288 | * Instead we retain the current runtime/deadline and let the new | |
3289 | * parameters take effect after the current reservation period lapses. | |
3290 | * This is safe (albeit pessimistic) because the 0-lag point is always | |
3291 | * before the current scheduling deadline. | |
3292 | * | |
3293 | * We can still have temporary overloads because we do not delay the | |
3294 | * change in bandwidth until that time; so admission control is | |
3295 | * not on the safe side. It does however guarantee tasks will never | |
3296 | * consume more than promised. | |
3297 | */ | |
aab03e05 DF |
3298 | } |
3299 | ||
c13db6b1 SR |
3300 | /* |
3301 | * sched_setparam() passes in -1 for its policy, to let the functions | |
3302 | * it calls know not to change it. | |
3303 | */ | |
3304 | #define SETPARAM_POLICY -1 | |
3305 | ||
c365c292 TG |
3306 | static void __setscheduler_params(struct task_struct *p, |
3307 | const struct sched_attr *attr) | |
1da177e4 | 3308 | { |
d50dde5a DF |
3309 | int policy = attr->sched_policy; |
3310 | ||
c13db6b1 | 3311 | if (policy == SETPARAM_POLICY) |
39fd8fd2 PZ |
3312 | policy = p->policy; |
3313 | ||
1da177e4 | 3314 | p->policy = policy; |
d50dde5a | 3315 | |
aab03e05 DF |
3316 | if (dl_policy(policy)) |
3317 | __setparam_dl(p, attr); | |
39fd8fd2 | 3318 | else if (fair_policy(policy)) |
d50dde5a DF |
3319 | p->static_prio = NICE_TO_PRIO(attr->sched_nice); |
3320 | ||
39fd8fd2 PZ |
3321 | /* |
3322 | * __sched_setscheduler() ensures attr->sched_priority == 0 when | |
3323 | * !rt_policy. Always setting this ensures that things like | |
3324 | * getparam()/getattr() don't report silly values for !rt tasks. | |
3325 | */ | |
3326 | p->rt_priority = attr->sched_priority; | |
383afd09 | 3327 | p->normal_prio = normal_prio(p); |
c365c292 TG |
3328 | set_load_weight(p); |
3329 | } | |
39fd8fd2 | 3330 | |
c365c292 TG |
3331 | /* Actually do priority change: must hold pi & rq lock. */ |
3332 | static void __setscheduler(struct rq *rq, struct task_struct *p, | |
3333 | const struct sched_attr *attr) | |
3334 | { | |
3335 | __setscheduler_params(p, attr); | |
d50dde5a | 3336 | |
383afd09 SR |
3337 | /* |
3338 | * If we get here, there was no pi waiters boosting the | |
3339 | * task. It is safe to use the normal prio. | |
3340 | */ | |
3341 | p->prio = normal_prio(p); | |
3342 | ||
aab03e05 DF |
3343 | if (dl_prio(p->prio)) |
3344 | p->sched_class = &dl_sched_class; | |
3345 | else if (rt_prio(p->prio)) | |
ffd44db5 PZ |
3346 | p->sched_class = &rt_sched_class; |
3347 | else | |
3348 | p->sched_class = &fair_sched_class; | |
1da177e4 | 3349 | } |
aab03e05 DF |
3350 | |
3351 | static void | |
3352 | __getparam_dl(struct task_struct *p, struct sched_attr *attr) | |
3353 | { | |
3354 | struct sched_dl_entity *dl_se = &p->dl; | |
3355 | ||
3356 | attr->sched_priority = p->rt_priority; | |
3357 | attr->sched_runtime = dl_se->dl_runtime; | |
3358 | attr->sched_deadline = dl_se->dl_deadline; | |
755378a4 | 3359 | attr->sched_period = dl_se->dl_period; |
aab03e05 DF |
3360 | attr->sched_flags = dl_se->flags; |
3361 | } | |
3362 | ||
3363 | /* | |
3364 | * This function validates the new parameters of a -deadline task. | |
3365 | * We ask for the deadline not being zero, and greater or equal | |
755378a4 | 3366 | * than the runtime, as well as the period of being zero or |
332ac17e | 3367 | * greater than deadline. Furthermore, we have to be sure that |
b0827819 JL |
3368 | * user parameters are above the internal resolution of 1us (we |
3369 | * check sched_runtime only since it is always the smaller one) and | |
3370 | * below 2^63 ns (we have to check both sched_deadline and | |
3371 | * sched_period, as the latter can be zero). | |
aab03e05 DF |
3372 | */ |
3373 | static bool | |
3374 | __checkparam_dl(const struct sched_attr *attr) | |
3375 | { | |
b0827819 JL |
3376 | /* deadline != 0 */ |
3377 | if (attr->sched_deadline == 0) | |
3378 | return false; | |
3379 | ||
3380 | /* | |
3381 | * Since we truncate DL_SCALE bits, make sure we're at least | |
3382 | * that big. | |
3383 | */ | |
3384 | if (attr->sched_runtime < (1ULL << DL_SCALE)) | |
3385 | return false; | |
3386 | ||
3387 | /* | |
3388 | * Since we use the MSB for wrap-around and sign issues, make | |
3389 | * sure it's not set (mind that period can be equal to zero). | |
3390 | */ | |
3391 | if (attr->sched_deadline & (1ULL << 63) || | |
3392 | attr->sched_period & (1ULL << 63)) | |
3393 | return false; | |
3394 | ||
3395 | /* runtime <= deadline <= period (if period != 0) */ | |
3396 | if ((attr->sched_period != 0 && | |
3397 | attr->sched_period < attr->sched_deadline) || | |
3398 | attr->sched_deadline < attr->sched_runtime) | |
3399 | return false; | |
3400 | ||
3401 | return true; | |
aab03e05 DF |
3402 | } |
3403 | ||
c69e8d9c DH |
3404 | /* |
3405 | * check the target process has a UID that matches the current process's | |
3406 | */ | |
3407 | static bool check_same_owner(struct task_struct *p) | |
3408 | { | |
3409 | const struct cred *cred = current_cred(), *pcred; | |
3410 | bool match; | |
3411 | ||
3412 | rcu_read_lock(); | |
3413 | pcred = __task_cred(p); | |
9c806aa0 EB |
3414 | match = (uid_eq(cred->euid, pcred->euid) || |
3415 | uid_eq(cred->euid, pcred->uid)); | |
c69e8d9c DH |
3416 | rcu_read_unlock(); |
3417 | return match; | |
3418 | } | |
3419 | ||
d50dde5a DF |
3420 | static int __sched_setscheduler(struct task_struct *p, |
3421 | const struct sched_attr *attr, | |
3422 | bool user) | |
1da177e4 | 3423 | { |
383afd09 SR |
3424 | int newprio = dl_policy(attr->sched_policy) ? MAX_DL_PRIO - 1 : |
3425 | MAX_RT_PRIO - 1 - attr->sched_priority; | |
da0c1e65 | 3426 | int retval, oldprio, oldpolicy = -1, queued, running; |
d50dde5a | 3427 | int policy = attr->sched_policy; |
1da177e4 | 3428 | unsigned long flags; |
83ab0aa0 | 3429 | const struct sched_class *prev_class; |
70b97a7f | 3430 | struct rq *rq; |
ca94c442 | 3431 | int reset_on_fork; |
1da177e4 | 3432 | |
66e5393a SR |
3433 | /* may grab non-irq protected spin_locks */ |
3434 | BUG_ON(in_interrupt()); | |
1da177e4 LT |
3435 | recheck: |
3436 | /* double check policy once rq lock held */ | |
ca94c442 LP |
3437 | if (policy < 0) { |
3438 | reset_on_fork = p->sched_reset_on_fork; | |
1da177e4 | 3439 | policy = oldpolicy = p->policy; |
ca94c442 | 3440 | } else { |
7479f3c9 | 3441 | reset_on_fork = !!(attr->sched_flags & SCHED_FLAG_RESET_ON_FORK); |
ca94c442 | 3442 | |
aab03e05 DF |
3443 | if (policy != SCHED_DEADLINE && |
3444 | policy != SCHED_FIFO && policy != SCHED_RR && | |
ca94c442 LP |
3445 | policy != SCHED_NORMAL && policy != SCHED_BATCH && |
3446 | policy != SCHED_IDLE) | |
3447 | return -EINVAL; | |
3448 | } | |
3449 | ||
7479f3c9 PZ |
3450 | if (attr->sched_flags & ~(SCHED_FLAG_RESET_ON_FORK)) |
3451 | return -EINVAL; | |
3452 | ||
1da177e4 LT |
3453 | /* |
3454 | * Valid priorities for SCHED_FIFO and SCHED_RR are | |
dd41f596 IM |
3455 | * 1..MAX_USER_RT_PRIO-1, valid priority for SCHED_NORMAL, |
3456 | * SCHED_BATCH and SCHED_IDLE is 0. | |
1da177e4 | 3457 | */ |
0bb040a4 | 3458 | if ((p->mm && attr->sched_priority > MAX_USER_RT_PRIO-1) || |
d50dde5a | 3459 | (!p->mm && attr->sched_priority > MAX_RT_PRIO-1)) |
1da177e4 | 3460 | return -EINVAL; |
aab03e05 DF |
3461 | if ((dl_policy(policy) && !__checkparam_dl(attr)) || |
3462 | (rt_policy(policy) != (attr->sched_priority != 0))) | |
1da177e4 LT |
3463 | return -EINVAL; |
3464 | ||
37e4ab3f OC |
3465 | /* |
3466 | * Allow unprivileged RT tasks to decrease priority: | |
3467 | */ | |
961ccddd | 3468 | if (user && !capable(CAP_SYS_NICE)) { |
d50dde5a | 3469 | if (fair_policy(policy)) { |
d0ea0268 | 3470 | if (attr->sched_nice < task_nice(p) && |
eaad4513 | 3471 | !can_nice(p, attr->sched_nice)) |
d50dde5a DF |
3472 | return -EPERM; |
3473 | } | |
3474 | ||
e05606d3 | 3475 | if (rt_policy(policy)) { |
a44702e8 ON |
3476 | unsigned long rlim_rtprio = |
3477 | task_rlimit(p, RLIMIT_RTPRIO); | |
8dc3e909 ON |
3478 | |
3479 | /* can't set/change the rt policy */ | |
3480 | if (policy != p->policy && !rlim_rtprio) | |
3481 | return -EPERM; | |
3482 | ||
3483 | /* can't increase priority */ | |
d50dde5a DF |
3484 | if (attr->sched_priority > p->rt_priority && |
3485 | attr->sched_priority > rlim_rtprio) | |
8dc3e909 ON |
3486 | return -EPERM; |
3487 | } | |
c02aa73b | 3488 | |
d44753b8 JL |
3489 | /* |
3490 | * Can't set/change SCHED_DEADLINE policy at all for now | |
3491 | * (safest behavior); in the future we would like to allow | |
3492 | * unprivileged DL tasks to increase their relative deadline | |
3493 | * or reduce their runtime (both ways reducing utilization) | |
3494 | */ | |
3495 | if (dl_policy(policy)) | |
3496 | return -EPERM; | |
3497 | ||
dd41f596 | 3498 | /* |
c02aa73b DH |
3499 | * Treat SCHED_IDLE as nice 20. Only allow a switch to |
3500 | * SCHED_NORMAL if the RLIMIT_NICE would normally permit it. | |
dd41f596 | 3501 | */ |
c02aa73b | 3502 | if (p->policy == SCHED_IDLE && policy != SCHED_IDLE) { |
d0ea0268 | 3503 | if (!can_nice(p, task_nice(p))) |
c02aa73b DH |
3504 | return -EPERM; |
3505 | } | |
5fe1d75f | 3506 | |
37e4ab3f | 3507 | /* can't change other user's priorities */ |
c69e8d9c | 3508 | if (!check_same_owner(p)) |
37e4ab3f | 3509 | return -EPERM; |
ca94c442 LP |
3510 | |
3511 | /* Normal users shall not reset the sched_reset_on_fork flag */ | |
3512 | if (p->sched_reset_on_fork && !reset_on_fork) | |
3513 | return -EPERM; | |
37e4ab3f | 3514 | } |
1da177e4 | 3515 | |
725aad24 | 3516 | if (user) { |
b0ae1981 | 3517 | retval = security_task_setscheduler(p); |
725aad24 JF |
3518 | if (retval) |
3519 | return retval; | |
3520 | } | |
3521 | ||
b29739f9 IM |
3522 | /* |
3523 | * make sure no PI-waiters arrive (or leave) while we are | |
3524 | * changing the priority of the task: | |
0122ec5b | 3525 | * |
25985edc | 3526 | * To be able to change p->policy safely, the appropriate |
1da177e4 LT |
3527 | * runqueue lock must be held. |
3528 | */ | |
0122ec5b | 3529 | rq = task_rq_lock(p, &flags); |
dc61b1d6 | 3530 | |
34f971f6 PZ |
3531 | /* |
3532 | * Changing the policy of the stop threads its a very bad idea | |
3533 | */ | |
3534 | if (p == rq->stop) { | |
0122ec5b | 3535 | task_rq_unlock(rq, p, &flags); |
34f971f6 PZ |
3536 | return -EINVAL; |
3537 | } | |
3538 | ||
a51e9198 | 3539 | /* |
d6b1e911 TG |
3540 | * If not changing anything there's no need to proceed further, |
3541 | * but store a possible modification of reset_on_fork. | |
a51e9198 | 3542 | */ |
d50dde5a | 3543 | if (unlikely(policy == p->policy)) { |
d0ea0268 | 3544 | if (fair_policy(policy) && attr->sched_nice != task_nice(p)) |
d50dde5a DF |
3545 | goto change; |
3546 | if (rt_policy(policy) && attr->sched_priority != p->rt_priority) | |
3547 | goto change; | |
aab03e05 DF |
3548 | if (dl_policy(policy)) |
3549 | goto change; | |
d50dde5a | 3550 | |
d6b1e911 | 3551 | p->sched_reset_on_fork = reset_on_fork; |
45afb173 | 3552 | task_rq_unlock(rq, p, &flags); |
a51e9198 DF |
3553 | return 0; |
3554 | } | |
d50dde5a | 3555 | change: |
a51e9198 | 3556 | |
dc61b1d6 | 3557 | if (user) { |
332ac17e | 3558 | #ifdef CONFIG_RT_GROUP_SCHED |
dc61b1d6 PZ |
3559 | /* |
3560 | * Do not allow realtime tasks into groups that have no runtime | |
3561 | * assigned. | |
3562 | */ | |
3563 | if (rt_bandwidth_enabled() && rt_policy(policy) && | |
f4493771 MG |
3564 | task_group(p)->rt_bandwidth.rt_runtime == 0 && |
3565 | !task_group_is_autogroup(task_group(p))) { | |
0122ec5b | 3566 | task_rq_unlock(rq, p, &flags); |
dc61b1d6 PZ |
3567 | return -EPERM; |
3568 | } | |
dc61b1d6 | 3569 | #endif |
332ac17e DF |
3570 | #ifdef CONFIG_SMP |
3571 | if (dl_bandwidth_enabled() && dl_policy(policy)) { | |
3572 | cpumask_t *span = rq->rd->span; | |
332ac17e DF |
3573 | |
3574 | /* | |
3575 | * Don't allow tasks with an affinity mask smaller than | |
3576 | * the entire root_domain to become SCHED_DEADLINE. We | |
3577 | * will also fail if there's no bandwidth available. | |
3578 | */ | |
e4099a5e PZ |
3579 | if (!cpumask_subset(span, &p->cpus_allowed) || |
3580 | rq->rd->dl_bw.bw == 0) { | |
332ac17e DF |
3581 | task_rq_unlock(rq, p, &flags); |
3582 | return -EPERM; | |
3583 | } | |
3584 | } | |
3585 | #endif | |
3586 | } | |
dc61b1d6 | 3587 | |
1da177e4 LT |
3588 | /* recheck policy now with rq lock held */ |
3589 | if (unlikely(oldpolicy != -1 && oldpolicy != p->policy)) { | |
3590 | policy = oldpolicy = -1; | |
0122ec5b | 3591 | task_rq_unlock(rq, p, &flags); |
1da177e4 LT |
3592 | goto recheck; |
3593 | } | |
332ac17e DF |
3594 | |
3595 | /* | |
3596 | * If setscheduling to SCHED_DEADLINE (or changing the parameters | |
3597 | * of a SCHED_DEADLINE task) we need to check if enough bandwidth | |
3598 | * is available. | |
3599 | */ | |
e4099a5e | 3600 | if ((dl_policy(policy) || dl_task(p)) && dl_overflow(p, policy, attr)) { |
332ac17e DF |
3601 | task_rq_unlock(rq, p, &flags); |
3602 | return -EBUSY; | |
3603 | } | |
3604 | ||
c365c292 TG |
3605 | p->sched_reset_on_fork = reset_on_fork; |
3606 | oldprio = p->prio; | |
3607 | ||
3608 | /* | |
3609 | * Special case for priority boosted tasks. | |
3610 | * | |
3611 | * If the new priority is lower or equal (user space view) | |
3612 | * than the current (boosted) priority, we just store the new | |
3613 | * normal parameters and do not touch the scheduler class and | |
3614 | * the runqueue. This will be done when the task deboost | |
3615 | * itself. | |
3616 | */ | |
3617 | if (rt_mutex_check_prio(p, newprio)) { | |
3618 | __setscheduler_params(p, attr); | |
3619 | task_rq_unlock(rq, p, &flags); | |
3620 | return 0; | |
3621 | } | |
3622 | ||
da0c1e65 | 3623 | queued = task_on_rq_queued(p); |
051a1d1a | 3624 | running = task_current(rq, p); |
da0c1e65 | 3625 | if (queued) |
4ca9b72b | 3626 | dequeue_task(rq, p, 0); |
0e1f3483 | 3627 | if (running) |
f3cd1c4e | 3628 | put_prev_task(rq, p); |
f6b53205 | 3629 | |
83ab0aa0 | 3630 | prev_class = p->sched_class; |
d50dde5a | 3631 | __setscheduler(rq, p, attr); |
f6b53205 | 3632 | |
0e1f3483 HS |
3633 | if (running) |
3634 | p->sched_class->set_curr_task(rq); | |
da0c1e65 | 3635 | if (queued) { |
81a44c54 TG |
3636 | /* |
3637 | * We enqueue to tail when the priority of a task is | |
3638 | * increased (user space view). | |
3639 | */ | |
3640 | enqueue_task(rq, p, oldprio <= p->prio ? ENQUEUE_HEAD : 0); | |
3641 | } | |
cb469845 | 3642 | |
da7a735e | 3643 | check_class_changed(rq, p, prev_class, oldprio); |
0122ec5b | 3644 | task_rq_unlock(rq, p, &flags); |
b29739f9 | 3645 | |
95e02ca9 TG |
3646 | rt_mutex_adjust_pi(p); |
3647 | ||
1da177e4 LT |
3648 | return 0; |
3649 | } | |
961ccddd | 3650 | |
7479f3c9 PZ |
3651 | static int _sched_setscheduler(struct task_struct *p, int policy, |
3652 | const struct sched_param *param, bool check) | |
3653 | { | |
3654 | struct sched_attr attr = { | |
3655 | .sched_policy = policy, | |
3656 | .sched_priority = param->sched_priority, | |
3657 | .sched_nice = PRIO_TO_NICE(p->static_prio), | |
3658 | }; | |
3659 | ||
c13db6b1 SR |
3660 | /* Fixup the legacy SCHED_RESET_ON_FORK hack. */ |
3661 | if ((policy != SETPARAM_POLICY) && (policy & SCHED_RESET_ON_FORK)) { | |
7479f3c9 PZ |
3662 | attr.sched_flags |= SCHED_FLAG_RESET_ON_FORK; |
3663 | policy &= ~SCHED_RESET_ON_FORK; | |
3664 | attr.sched_policy = policy; | |
3665 | } | |
3666 | ||
3667 | return __sched_setscheduler(p, &attr, check); | |
3668 | } | |
961ccddd RR |
3669 | /** |
3670 | * sched_setscheduler - change the scheduling policy and/or RT priority of a thread. | |
3671 | * @p: the task in question. | |
3672 | * @policy: new policy. | |
3673 | * @param: structure containing the new RT priority. | |
3674 | * | |
e69f6186 YB |
3675 | * Return: 0 on success. An error code otherwise. |
3676 | * | |
961ccddd RR |
3677 | * NOTE that the task may be already dead. |
3678 | */ | |
3679 | int sched_setscheduler(struct task_struct *p, int policy, | |
fe7de49f | 3680 | const struct sched_param *param) |
961ccddd | 3681 | { |
7479f3c9 | 3682 | return _sched_setscheduler(p, policy, param, true); |
961ccddd | 3683 | } |
1da177e4 LT |
3684 | EXPORT_SYMBOL_GPL(sched_setscheduler); |
3685 | ||
d50dde5a DF |
3686 | int sched_setattr(struct task_struct *p, const struct sched_attr *attr) |
3687 | { | |
3688 | return __sched_setscheduler(p, attr, true); | |
3689 | } | |
3690 | EXPORT_SYMBOL_GPL(sched_setattr); | |
3691 | ||
961ccddd RR |
3692 | /** |
3693 | * sched_setscheduler_nocheck - change the scheduling policy and/or RT priority of a thread from kernelspace. | |
3694 | * @p: the task in question. | |
3695 | * @policy: new policy. | |
3696 | * @param: structure containing the new RT priority. | |
3697 | * | |
3698 | * Just like sched_setscheduler, only don't bother checking if the | |
3699 | * current context has permission. For example, this is needed in | |
3700 | * stop_machine(): we create temporary high priority worker threads, | |
3701 | * but our caller might not have that capability. | |
e69f6186 YB |
3702 | * |
3703 | * Return: 0 on success. An error code otherwise. | |
961ccddd RR |
3704 | */ |
3705 | int sched_setscheduler_nocheck(struct task_struct *p, int policy, | |
fe7de49f | 3706 | const struct sched_param *param) |
961ccddd | 3707 | { |
7479f3c9 | 3708 | return _sched_setscheduler(p, policy, param, false); |
961ccddd RR |
3709 | } |
3710 | ||
95cdf3b7 IM |
3711 | static int |
3712 | do_sched_setscheduler(pid_t pid, int policy, struct sched_param __user *param) | |
1da177e4 | 3713 | { |
1da177e4 LT |
3714 | struct sched_param lparam; |
3715 | struct task_struct *p; | |
36c8b586 | 3716 | int retval; |
1da177e4 LT |
3717 | |
3718 | if (!param || pid < 0) | |
3719 | return -EINVAL; | |
3720 | if (copy_from_user(&lparam, param, sizeof(struct sched_param))) | |
3721 | return -EFAULT; | |
5fe1d75f ON |
3722 | |
3723 | rcu_read_lock(); | |
3724 | retval = -ESRCH; | |
1da177e4 | 3725 | p = find_process_by_pid(pid); |
5fe1d75f ON |
3726 | if (p != NULL) |
3727 | retval = sched_setscheduler(p, policy, &lparam); | |
3728 | rcu_read_unlock(); | |
36c8b586 | 3729 | |
1da177e4 LT |
3730 | return retval; |
3731 | } | |
3732 | ||
d50dde5a DF |
3733 | /* |
3734 | * Mimics kernel/events/core.c perf_copy_attr(). | |
3735 | */ | |
3736 | static int sched_copy_attr(struct sched_attr __user *uattr, | |
3737 | struct sched_attr *attr) | |
3738 | { | |
3739 | u32 size; | |
3740 | int ret; | |
3741 | ||
3742 | if (!access_ok(VERIFY_WRITE, uattr, SCHED_ATTR_SIZE_VER0)) | |
3743 | return -EFAULT; | |
3744 | ||
3745 | /* | |
3746 | * zero the full structure, so that a short copy will be nice. | |
3747 | */ | |
3748 | memset(attr, 0, sizeof(*attr)); | |
3749 | ||
3750 | ret = get_user(size, &uattr->size); | |
3751 | if (ret) | |
3752 | return ret; | |
3753 | ||
3754 | if (size > PAGE_SIZE) /* silly large */ | |
3755 | goto err_size; | |
3756 | ||
3757 | if (!size) /* abi compat */ | |
3758 | size = SCHED_ATTR_SIZE_VER0; | |
3759 | ||
3760 | if (size < SCHED_ATTR_SIZE_VER0) | |
3761 | goto err_size; | |
3762 | ||
3763 | /* | |
3764 | * If we're handed a bigger struct than we know of, | |
3765 | * ensure all the unknown bits are 0 - i.e. new | |
3766 | * user-space does not rely on any kernel feature | |
3767 | * extensions we dont know about yet. | |
3768 | */ | |
3769 | if (size > sizeof(*attr)) { | |
3770 | unsigned char __user *addr; | |
3771 | unsigned char __user *end; | |
3772 | unsigned char val; | |
3773 | ||
3774 | addr = (void __user *)uattr + sizeof(*attr); | |
3775 | end = (void __user *)uattr + size; | |
3776 | ||
3777 | for (; addr < end; addr++) { | |
3778 | ret = get_user(val, addr); | |
3779 | if (ret) | |
3780 | return ret; | |
3781 | if (val) | |
3782 | goto err_size; | |
3783 | } | |
3784 | size = sizeof(*attr); | |
3785 | } | |
3786 | ||
3787 | ret = copy_from_user(attr, uattr, size); | |
3788 | if (ret) | |
3789 | return -EFAULT; | |
3790 | ||
3791 | /* | |
3792 | * XXX: do we want to be lenient like existing syscalls; or do we want | |
3793 | * to be strict and return an error on out-of-bounds values? | |
3794 | */ | |
75e45d51 | 3795 | attr->sched_nice = clamp(attr->sched_nice, MIN_NICE, MAX_NICE); |
d50dde5a | 3796 | |
e78c7bca | 3797 | return 0; |
d50dde5a DF |
3798 | |
3799 | err_size: | |
3800 | put_user(sizeof(*attr), &uattr->size); | |
e78c7bca | 3801 | return -E2BIG; |
d50dde5a DF |
3802 | } |
3803 | ||
1da177e4 LT |
3804 | /** |
3805 | * sys_sched_setscheduler - set/change the scheduler policy and RT priority | |
3806 | * @pid: the pid in question. | |
3807 | * @policy: new policy. | |
3808 | * @param: structure containing the new RT priority. | |
e69f6186 YB |
3809 | * |
3810 | * Return: 0 on success. An error code otherwise. | |
1da177e4 | 3811 | */ |
5add95d4 HC |
3812 | SYSCALL_DEFINE3(sched_setscheduler, pid_t, pid, int, policy, |
3813 | struct sched_param __user *, param) | |
1da177e4 | 3814 | { |
c21761f1 JB |
3815 | /* negative values for policy are not valid */ |
3816 | if (policy < 0) | |
3817 | return -EINVAL; | |
3818 | ||
1da177e4 LT |
3819 | return do_sched_setscheduler(pid, policy, param); |
3820 | } | |
3821 | ||
3822 | /** | |
3823 | * sys_sched_setparam - set/change the RT priority of a thread | |
3824 | * @pid: the pid in question. | |
3825 | * @param: structure containing the new RT priority. | |
e69f6186 YB |
3826 | * |
3827 | * Return: 0 on success. An error code otherwise. | |
1da177e4 | 3828 | */ |
5add95d4 | 3829 | SYSCALL_DEFINE2(sched_setparam, pid_t, pid, struct sched_param __user *, param) |
1da177e4 | 3830 | { |
c13db6b1 | 3831 | return do_sched_setscheduler(pid, SETPARAM_POLICY, param); |
1da177e4 LT |
3832 | } |
3833 | ||
d50dde5a DF |
3834 | /** |
3835 | * sys_sched_setattr - same as above, but with extended sched_attr | |
3836 | * @pid: the pid in question. | |
5778fccf | 3837 | * @uattr: structure containing the extended parameters. |
db66d756 | 3838 | * @flags: for future extension. |
d50dde5a | 3839 | */ |
6d35ab48 PZ |
3840 | SYSCALL_DEFINE3(sched_setattr, pid_t, pid, struct sched_attr __user *, uattr, |
3841 | unsigned int, flags) | |
d50dde5a DF |
3842 | { |
3843 | struct sched_attr attr; | |
3844 | struct task_struct *p; | |
3845 | int retval; | |
3846 | ||
6d35ab48 | 3847 | if (!uattr || pid < 0 || flags) |
d50dde5a DF |
3848 | return -EINVAL; |
3849 | ||
143cf23d MK |
3850 | retval = sched_copy_attr(uattr, &attr); |
3851 | if (retval) | |
3852 | return retval; | |
d50dde5a | 3853 | |
b14ed2c2 | 3854 | if ((int)attr.sched_policy < 0) |
dbdb2275 | 3855 | return -EINVAL; |
d50dde5a DF |
3856 | |
3857 | rcu_read_lock(); | |
3858 | retval = -ESRCH; | |
3859 | p = find_process_by_pid(pid); | |
3860 | if (p != NULL) | |
3861 | retval = sched_setattr(p, &attr); | |
3862 | rcu_read_unlock(); | |
3863 | ||
3864 | return retval; | |
3865 | } | |
3866 | ||
1da177e4 LT |
3867 | /** |
3868 | * sys_sched_getscheduler - get the policy (scheduling class) of a thread | |
3869 | * @pid: the pid in question. | |
e69f6186 YB |
3870 | * |
3871 | * Return: On success, the policy of the thread. Otherwise, a negative error | |
3872 | * code. | |
1da177e4 | 3873 | */ |
5add95d4 | 3874 | SYSCALL_DEFINE1(sched_getscheduler, pid_t, pid) |
1da177e4 | 3875 | { |
36c8b586 | 3876 | struct task_struct *p; |
3a5c359a | 3877 | int retval; |
1da177e4 LT |
3878 | |
3879 | if (pid < 0) | |
3a5c359a | 3880 | return -EINVAL; |
1da177e4 LT |
3881 | |
3882 | retval = -ESRCH; | |
5fe85be0 | 3883 | rcu_read_lock(); |
1da177e4 LT |
3884 | p = find_process_by_pid(pid); |
3885 | if (p) { | |
3886 | retval = security_task_getscheduler(p); | |
3887 | if (!retval) | |
ca94c442 LP |
3888 | retval = p->policy |
3889 | | (p->sched_reset_on_fork ? SCHED_RESET_ON_FORK : 0); | |
1da177e4 | 3890 | } |
5fe85be0 | 3891 | rcu_read_unlock(); |
1da177e4 LT |
3892 | return retval; |
3893 | } | |
3894 | ||
3895 | /** | |
ca94c442 | 3896 | * sys_sched_getparam - get the RT priority of a thread |
1da177e4 LT |
3897 | * @pid: the pid in question. |
3898 | * @param: structure containing the RT priority. | |
e69f6186 YB |
3899 | * |
3900 | * Return: On success, 0 and the RT priority is in @param. Otherwise, an error | |
3901 | * code. | |
1da177e4 | 3902 | */ |
5add95d4 | 3903 | SYSCALL_DEFINE2(sched_getparam, pid_t, pid, struct sched_param __user *, param) |
1da177e4 | 3904 | { |
ce5f7f82 | 3905 | struct sched_param lp = { .sched_priority = 0 }; |
36c8b586 | 3906 | struct task_struct *p; |
3a5c359a | 3907 | int retval; |
1da177e4 LT |
3908 | |
3909 | if (!param || pid < 0) | |
3a5c359a | 3910 | return -EINVAL; |
1da177e4 | 3911 | |
5fe85be0 | 3912 | rcu_read_lock(); |
1da177e4 LT |
3913 | p = find_process_by_pid(pid); |
3914 | retval = -ESRCH; | |
3915 | if (!p) | |
3916 | goto out_unlock; | |
3917 | ||
3918 | retval = security_task_getscheduler(p); | |
3919 | if (retval) | |
3920 | goto out_unlock; | |
3921 | ||
ce5f7f82 PZ |
3922 | if (task_has_rt_policy(p)) |
3923 | lp.sched_priority = p->rt_priority; | |
5fe85be0 | 3924 | rcu_read_unlock(); |
1da177e4 LT |
3925 | |
3926 | /* | |
3927 | * This one might sleep, we cannot do it with a spinlock held ... | |
3928 | */ | |
3929 | retval = copy_to_user(param, &lp, sizeof(*param)) ? -EFAULT : 0; | |
3930 | ||
1da177e4 LT |
3931 | return retval; |
3932 | ||
3933 | out_unlock: | |
5fe85be0 | 3934 | rcu_read_unlock(); |
1da177e4 LT |
3935 | return retval; |
3936 | } | |
3937 | ||
d50dde5a DF |
3938 | static int sched_read_attr(struct sched_attr __user *uattr, |
3939 | struct sched_attr *attr, | |
3940 | unsigned int usize) | |
3941 | { | |
3942 | int ret; | |
3943 | ||
3944 | if (!access_ok(VERIFY_WRITE, uattr, usize)) | |
3945 | return -EFAULT; | |
3946 | ||
3947 | /* | |
3948 | * If we're handed a smaller struct than we know of, | |
3949 | * ensure all the unknown bits are 0 - i.e. old | |
3950 | * user-space does not get uncomplete information. | |
3951 | */ | |
3952 | if (usize < sizeof(*attr)) { | |
3953 | unsigned char *addr; | |
3954 | unsigned char *end; | |
3955 | ||
3956 | addr = (void *)attr + usize; | |
3957 | end = (void *)attr + sizeof(*attr); | |
3958 | ||
3959 | for (; addr < end; addr++) { | |
3960 | if (*addr) | |
22400674 | 3961 | return -EFBIG; |
d50dde5a DF |
3962 | } |
3963 | ||
3964 | attr->size = usize; | |
3965 | } | |
3966 | ||
4efbc454 | 3967 | ret = copy_to_user(uattr, attr, attr->size); |
d50dde5a DF |
3968 | if (ret) |
3969 | return -EFAULT; | |
3970 | ||
22400674 | 3971 | return 0; |
d50dde5a DF |
3972 | } |
3973 | ||
3974 | /** | |
aab03e05 | 3975 | * sys_sched_getattr - similar to sched_getparam, but with sched_attr |
d50dde5a | 3976 | * @pid: the pid in question. |
5778fccf | 3977 | * @uattr: structure containing the extended parameters. |
d50dde5a | 3978 | * @size: sizeof(attr) for fwd/bwd comp. |
db66d756 | 3979 | * @flags: for future extension. |
d50dde5a | 3980 | */ |
6d35ab48 PZ |
3981 | SYSCALL_DEFINE4(sched_getattr, pid_t, pid, struct sched_attr __user *, uattr, |
3982 | unsigned int, size, unsigned int, flags) | |
d50dde5a DF |
3983 | { |
3984 | struct sched_attr attr = { | |
3985 | .size = sizeof(struct sched_attr), | |
3986 | }; | |
3987 | struct task_struct *p; | |
3988 | int retval; | |
3989 | ||
3990 | if (!uattr || pid < 0 || size > PAGE_SIZE || | |
6d35ab48 | 3991 | size < SCHED_ATTR_SIZE_VER0 || flags) |
d50dde5a DF |
3992 | return -EINVAL; |
3993 | ||
3994 | rcu_read_lock(); | |
3995 | p = find_process_by_pid(pid); | |
3996 | retval = -ESRCH; | |
3997 | if (!p) | |
3998 | goto out_unlock; | |
3999 | ||
4000 | retval = security_task_getscheduler(p); | |
4001 | if (retval) | |
4002 | goto out_unlock; | |
4003 | ||
4004 | attr.sched_policy = p->policy; | |
7479f3c9 PZ |
4005 | if (p->sched_reset_on_fork) |
4006 | attr.sched_flags |= SCHED_FLAG_RESET_ON_FORK; | |
aab03e05 DF |
4007 | if (task_has_dl_policy(p)) |
4008 | __getparam_dl(p, &attr); | |
4009 | else if (task_has_rt_policy(p)) | |
d50dde5a DF |
4010 | attr.sched_priority = p->rt_priority; |
4011 | else | |
d0ea0268 | 4012 | attr.sched_nice = task_nice(p); |
d50dde5a DF |
4013 | |
4014 | rcu_read_unlock(); | |
4015 | ||
4016 | retval = sched_read_attr(uattr, &attr, size); | |
4017 | return retval; | |
4018 | ||
4019 | out_unlock: | |
4020 | rcu_read_unlock(); | |
4021 | return retval; | |
4022 | } | |
4023 | ||
96f874e2 | 4024 | long sched_setaffinity(pid_t pid, const struct cpumask *in_mask) |
1da177e4 | 4025 | { |
5a16f3d3 | 4026 | cpumask_var_t cpus_allowed, new_mask; |
36c8b586 IM |
4027 | struct task_struct *p; |
4028 | int retval; | |
1da177e4 | 4029 | |
23f5d142 | 4030 | rcu_read_lock(); |
1da177e4 LT |
4031 | |
4032 | p = find_process_by_pid(pid); | |
4033 | if (!p) { | |
23f5d142 | 4034 | rcu_read_unlock(); |
1da177e4 LT |
4035 | return -ESRCH; |
4036 | } | |
4037 | ||
23f5d142 | 4038 | /* Prevent p going away */ |
1da177e4 | 4039 | get_task_struct(p); |
23f5d142 | 4040 | rcu_read_unlock(); |
1da177e4 | 4041 | |
14a40ffc TH |
4042 | if (p->flags & PF_NO_SETAFFINITY) { |
4043 | retval = -EINVAL; | |
4044 | goto out_put_task; | |
4045 | } | |
5a16f3d3 RR |
4046 | if (!alloc_cpumask_var(&cpus_allowed, GFP_KERNEL)) { |
4047 | retval = -ENOMEM; | |
4048 | goto out_put_task; | |
4049 | } | |
4050 | if (!alloc_cpumask_var(&new_mask, GFP_KERNEL)) { | |
4051 | retval = -ENOMEM; | |
4052 | goto out_free_cpus_allowed; | |
4053 | } | |
1da177e4 | 4054 | retval = -EPERM; |
4c44aaaf EB |
4055 | if (!check_same_owner(p)) { |
4056 | rcu_read_lock(); | |
4057 | if (!ns_capable(__task_cred(p)->user_ns, CAP_SYS_NICE)) { | |
4058 | rcu_read_unlock(); | |
16303ab2 | 4059 | goto out_free_new_mask; |
4c44aaaf EB |
4060 | } |
4061 | rcu_read_unlock(); | |
4062 | } | |
1da177e4 | 4063 | |
b0ae1981 | 4064 | retval = security_task_setscheduler(p); |
e7834f8f | 4065 | if (retval) |
16303ab2 | 4066 | goto out_free_new_mask; |
e7834f8f | 4067 | |
e4099a5e PZ |
4068 | |
4069 | cpuset_cpus_allowed(p, cpus_allowed); | |
4070 | cpumask_and(new_mask, in_mask, cpus_allowed); | |
4071 | ||
332ac17e DF |
4072 | /* |
4073 | * Since bandwidth control happens on root_domain basis, | |
4074 | * if admission test is enabled, we only admit -deadline | |
4075 | * tasks allowed to run on all the CPUs in the task's | |
4076 | * root_domain. | |
4077 | */ | |
4078 | #ifdef CONFIG_SMP | |
f1e3a093 KT |
4079 | if (task_has_dl_policy(p) && dl_bandwidth_enabled()) { |
4080 | rcu_read_lock(); | |
4081 | if (!cpumask_subset(task_rq(p)->rd->span, new_mask)) { | |
332ac17e | 4082 | retval = -EBUSY; |
f1e3a093 | 4083 | rcu_read_unlock(); |
16303ab2 | 4084 | goto out_free_new_mask; |
332ac17e | 4085 | } |
f1e3a093 | 4086 | rcu_read_unlock(); |
332ac17e DF |
4087 | } |
4088 | #endif | |
49246274 | 4089 | again: |
5a16f3d3 | 4090 | retval = set_cpus_allowed_ptr(p, new_mask); |
1da177e4 | 4091 | |
8707d8b8 | 4092 | if (!retval) { |
5a16f3d3 RR |
4093 | cpuset_cpus_allowed(p, cpus_allowed); |
4094 | if (!cpumask_subset(new_mask, cpus_allowed)) { | |
8707d8b8 PM |
4095 | /* |
4096 | * We must have raced with a concurrent cpuset | |
4097 | * update. Just reset the cpus_allowed to the | |
4098 | * cpuset's cpus_allowed | |
4099 | */ | |
5a16f3d3 | 4100 | cpumask_copy(new_mask, cpus_allowed); |
8707d8b8 PM |
4101 | goto again; |
4102 | } | |
4103 | } | |
16303ab2 | 4104 | out_free_new_mask: |
5a16f3d3 RR |
4105 | free_cpumask_var(new_mask); |
4106 | out_free_cpus_allowed: | |
4107 | free_cpumask_var(cpus_allowed); | |
4108 | out_put_task: | |
1da177e4 | 4109 | put_task_struct(p); |
1da177e4 LT |
4110 | return retval; |
4111 | } | |
4112 | ||
4113 | static int get_user_cpu_mask(unsigned long __user *user_mask_ptr, unsigned len, | |
96f874e2 | 4114 | struct cpumask *new_mask) |
1da177e4 | 4115 | { |
96f874e2 RR |
4116 | if (len < cpumask_size()) |
4117 | cpumask_clear(new_mask); | |
4118 | else if (len > cpumask_size()) | |
4119 | len = cpumask_size(); | |
4120 | ||
1da177e4 LT |
4121 | return copy_from_user(new_mask, user_mask_ptr, len) ? -EFAULT : 0; |
4122 | } | |
4123 | ||
4124 | /** | |
4125 | * sys_sched_setaffinity - set the cpu affinity of a process | |
4126 | * @pid: pid of the process | |
4127 | * @len: length in bytes of the bitmask pointed to by user_mask_ptr | |
4128 | * @user_mask_ptr: user-space pointer to the new cpu mask | |
e69f6186 YB |
4129 | * |
4130 | * Return: 0 on success. An error code otherwise. | |
1da177e4 | 4131 | */ |
5add95d4 HC |
4132 | SYSCALL_DEFINE3(sched_setaffinity, pid_t, pid, unsigned int, len, |
4133 | unsigned long __user *, user_mask_ptr) | |
1da177e4 | 4134 | { |
5a16f3d3 | 4135 | cpumask_var_t new_mask; |
1da177e4 LT |
4136 | int retval; |
4137 | ||
5a16f3d3 RR |
4138 | if (!alloc_cpumask_var(&new_mask, GFP_KERNEL)) |
4139 | return -ENOMEM; | |
1da177e4 | 4140 | |
5a16f3d3 RR |
4141 | retval = get_user_cpu_mask(user_mask_ptr, len, new_mask); |
4142 | if (retval == 0) | |
4143 | retval = sched_setaffinity(pid, new_mask); | |
4144 | free_cpumask_var(new_mask); | |
4145 | return retval; | |
1da177e4 LT |
4146 | } |
4147 | ||
96f874e2 | 4148 | long sched_getaffinity(pid_t pid, struct cpumask *mask) |
1da177e4 | 4149 | { |
36c8b586 | 4150 | struct task_struct *p; |
31605683 | 4151 | unsigned long flags; |
1da177e4 | 4152 | int retval; |
1da177e4 | 4153 | |
23f5d142 | 4154 | rcu_read_lock(); |
1da177e4 LT |
4155 | |
4156 | retval = -ESRCH; | |
4157 | p = find_process_by_pid(pid); | |
4158 | if (!p) | |
4159 | goto out_unlock; | |
4160 | ||
e7834f8f DQ |
4161 | retval = security_task_getscheduler(p); |
4162 | if (retval) | |
4163 | goto out_unlock; | |
4164 | ||
013fdb80 | 4165 | raw_spin_lock_irqsave(&p->pi_lock, flags); |
6acce3ef | 4166 | cpumask_and(mask, &p->cpus_allowed, cpu_active_mask); |
013fdb80 | 4167 | raw_spin_unlock_irqrestore(&p->pi_lock, flags); |
1da177e4 LT |
4168 | |
4169 | out_unlock: | |
23f5d142 | 4170 | rcu_read_unlock(); |
1da177e4 | 4171 | |
9531b62f | 4172 | return retval; |
1da177e4 LT |
4173 | } |
4174 | ||
4175 | /** | |
4176 | * sys_sched_getaffinity - get the cpu affinity of a process | |
4177 | * @pid: pid of the process | |
4178 | * @len: length in bytes of the bitmask pointed to by user_mask_ptr | |
4179 | * @user_mask_ptr: user-space pointer to hold the current cpu mask | |
e69f6186 YB |
4180 | * |
4181 | * Return: 0 on success. An error code otherwise. | |
1da177e4 | 4182 | */ |
5add95d4 HC |
4183 | SYSCALL_DEFINE3(sched_getaffinity, pid_t, pid, unsigned int, len, |
4184 | unsigned long __user *, user_mask_ptr) | |
1da177e4 LT |
4185 | { |
4186 | int ret; | |
f17c8607 | 4187 | cpumask_var_t mask; |
1da177e4 | 4188 | |
84fba5ec | 4189 | if ((len * BITS_PER_BYTE) < nr_cpu_ids) |
cd3d8031 KM |
4190 | return -EINVAL; |
4191 | if (len & (sizeof(unsigned long)-1)) | |
1da177e4 LT |
4192 | return -EINVAL; |
4193 | ||
f17c8607 RR |
4194 | if (!alloc_cpumask_var(&mask, GFP_KERNEL)) |
4195 | return -ENOMEM; | |
1da177e4 | 4196 | |
f17c8607 RR |
4197 | ret = sched_getaffinity(pid, mask); |
4198 | if (ret == 0) { | |
8bc037fb | 4199 | size_t retlen = min_t(size_t, len, cpumask_size()); |
cd3d8031 KM |
4200 | |
4201 | if (copy_to_user(user_mask_ptr, mask, retlen)) | |
f17c8607 RR |
4202 | ret = -EFAULT; |
4203 | else | |
cd3d8031 | 4204 | ret = retlen; |
f17c8607 RR |
4205 | } |
4206 | free_cpumask_var(mask); | |
1da177e4 | 4207 | |
f17c8607 | 4208 | return ret; |
1da177e4 LT |
4209 | } |
4210 | ||
4211 | /** | |
4212 | * sys_sched_yield - yield the current processor to other threads. | |
4213 | * | |
dd41f596 IM |
4214 | * This function yields the current CPU to other tasks. If there are no |
4215 | * other threads running on this CPU then this function will return. | |
e69f6186 YB |
4216 | * |
4217 | * Return: 0. | |
1da177e4 | 4218 | */ |
5add95d4 | 4219 | SYSCALL_DEFINE0(sched_yield) |
1da177e4 | 4220 | { |
70b97a7f | 4221 | struct rq *rq = this_rq_lock(); |
1da177e4 | 4222 | |
2d72376b | 4223 | schedstat_inc(rq, yld_count); |
4530d7ab | 4224 | current->sched_class->yield_task(rq); |
1da177e4 LT |
4225 | |
4226 | /* | |
4227 | * Since we are going to call schedule() anyway, there's | |
4228 | * no need to preempt or enable interrupts: | |
4229 | */ | |
4230 | __release(rq->lock); | |
8a25d5de | 4231 | spin_release(&rq->lock.dep_map, 1, _THIS_IP_); |
9828ea9d | 4232 | do_raw_spin_unlock(&rq->lock); |
ba74c144 | 4233 | sched_preempt_enable_no_resched(); |
1da177e4 LT |
4234 | |
4235 | schedule(); | |
4236 | ||
4237 | return 0; | |
4238 | } | |
4239 | ||
02b67cc3 | 4240 | int __sched _cond_resched(void) |
1da177e4 | 4241 | { |
d86ee480 | 4242 | if (should_resched()) { |
a18b5d01 | 4243 | preempt_schedule_common(); |
1da177e4 LT |
4244 | return 1; |
4245 | } | |
4246 | return 0; | |
4247 | } | |
02b67cc3 | 4248 | EXPORT_SYMBOL(_cond_resched); |
1da177e4 LT |
4249 | |
4250 | /* | |
613afbf8 | 4251 | * __cond_resched_lock() - if a reschedule is pending, drop the given lock, |
1da177e4 LT |
4252 | * call schedule, and on return reacquire the lock. |
4253 | * | |
41a2d6cf | 4254 | * This works OK both with and without CONFIG_PREEMPT. We do strange low-level |
1da177e4 LT |
4255 | * operations here to prevent schedule() from being called twice (once via |
4256 | * spin_unlock(), once by hand). | |
4257 | */ | |
613afbf8 | 4258 | int __cond_resched_lock(spinlock_t *lock) |
1da177e4 | 4259 | { |
d86ee480 | 4260 | int resched = should_resched(); |
6df3cecb JK |
4261 | int ret = 0; |
4262 | ||
f607c668 PZ |
4263 | lockdep_assert_held(lock); |
4264 | ||
4a81e832 | 4265 | if (spin_needbreak(lock) || resched) { |
1da177e4 | 4266 | spin_unlock(lock); |
d86ee480 | 4267 | if (resched) |
a18b5d01 | 4268 | preempt_schedule_common(); |
95c354fe NP |
4269 | else |
4270 | cpu_relax(); | |
6df3cecb | 4271 | ret = 1; |
1da177e4 | 4272 | spin_lock(lock); |
1da177e4 | 4273 | } |
6df3cecb | 4274 | return ret; |
1da177e4 | 4275 | } |
613afbf8 | 4276 | EXPORT_SYMBOL(__cond_resched_lock); |
1da177e4 | 4277 | |
613afbf8 | 4278 | int __sched __cond_resched_softirq(void) |
1da177e4 LT |
4279 | { |
4280 | BUG_ON(!in_softirq()); | |
4281 | ||
d86ee480 | 4282 | if (should_resched()) { |
98d82567 | 4283 | local_bh_enable(); |
a18b5d01 | 4284 | preempt_schedule_common(); |
1da177e4 LT |
4285 | local_bh_disable(); |
4286 | return 1; | |
4287 | } | |
4288 | return 0; | |
4289 | } | |
613afbf8 | 4290 | EXPORT_SYMBOL(__cond_resched_softirq); |
1da177e4 | 4291 | |
1da177e4 LT |
4292 | /** |
4293 | * yield - yield the current processor to other threads. | |
4294 | * | |
8e3fabfd PZ |
4295 | * Do not ever use this function, there's a 99% chance you're doing it wrong. |
4296 | * | |
4297 | * The scheduler is at all times free to pick the calling task as the most | |
4298 | * eligible task to run, if removing the yield() call from your code breaks | |
4299 | * it, its already broken. | |
4300 | * | |
4301 | * Typical broken usage is: | |
4302 | * | |
4303 | * while (!event) | |
4304 | * yield(); | |
4305 | * | |
4306 | * where one assumes that yield() will let 'the other' process run that will | |
4307 | * make event true. If the current task is a SCHED_FIFO task that will never | |
4308 | * happen. Never use yield() as a progress guarantee!! | |
4309 | * | |
4310 | * If you want to use yield() to wait for something, use wait_event(). | |
4311 | * If you want to use yield() to be 'nice' for others, use cond_resched(). | |
4312 | * If you still want to use yield(), do not! | |
1da177e4 LT |
4313 | */ |
4314 | void __sched yield(void) | |
4315 | { | |
4316 | set_current_state(TASK_RUNNING); | |
4317 | sys_sched_yield(); | |
4318 | } | |
1da177e4 LT |
4319 | EXPORT_SYMBOL(yield); |
4320 | ||
d95f4122 MG |
4321 | /** |
4322 | * yield_to - yield the current processor to another thread in | |
4323 | * your thread group, or accelerate that thread toward the | |
4324 | * processor it's on. | |
16addf95 RD |
4325 | * @p: target task |
4326 | * @preempt: whether task preemption is allowed or not | |
d95f4122 MG |
4327 | * |
4328 | * It's the caller's job to ensure that the target task struct | |
4329 | * can't go away on us before we can do any checks. | |
4330 | * | |
e69f6186 | 4331 | * Return: |
7b270f60 PZ |
4332 | * true (>0) if we indeed boosted the target task. |
4333 | * false (0) if we failed to boost the target. | |
4334 | * -ESRCH if there's no task to yield to. | |
d95f4122 | 4335 | */ |
fa93384f | 4336 | int __sched yield_to(struct task_struct *p, bool preempt) |
d95f4122 MG |
4337 | { |
4338 | struct task_struct *curr = current; | |
4339 | struct rq *rq, *p_rq; | |
4340 | unsigned long flags; | |
c3c18640 | 4341 | int yielded = 0; |
d95f4122 MG |
4342 | |
4343 | local_irq_save(flags); | |
4344 | rq = this_rq(); | |
4345 | ||
4346 | again: | |
4347 | p_rq = task_rq(p); | |
7b270f60 PZ |
4348 | /* |
4349 | * If we're the only runnable task on the rq and target rq also | |
4350 | * has only one task, there's absolutely no point in yielding. | |
4351 | */ | |
4352 | if (rq->nr_running == 1 && p_rq->nr_running == 1) { | |
4353 | yielded = -ESRCH; | |
4354 | goto out_irq; | |
4355 | } | |
4356 | ||
d95f4122 | 4357 | double_rq_lock(rq, p_rq); |
39e24d8f | 4358 | if (task_rq(p) != p_rq) { |
d95f4122 MG |
4359 | double_rq_unlock(rq, p_rq); |
4360 | goto again; | |
4361 | } | |
4362 | ||
4363 | if (!curr->sched_class->yield_to_task) | |
7b270f60 | 4364 | goto out_unlock; |
d95f4122 MG |
4365 | |
4366 | if (curr->sched_class != p->sched_class) | |
7b270f60 | 4367 | goto out_unlock; |
d95f4122 MG |
4368 | |
4369 | if (task_running(p_rq, p) || p->state) | |
7b270f60 | 4370 | goto out_unlock; |
d95f4122 MG |
4371 | |
4372 | yielded = curr->sched_class->yield_to_task(rq, p, preempt); | |
6d1cafd8 | 4373 | if (yielded) { |
d95f4122 | 4374 | schedstat_inc(rq, yld_count); |
6d1cafd8 VP |
4375 | /* |
4376 | * Make p's CPU reschedule; pick_next_entity takes care of | |
4377 | * fairness. | |
4378 | */ | |
4379 | if (preempt && rq != p_rq) | |
8875125e | 4380 | resched_curr(p_rq); |
6d1cafd8 | 4381 | } |
d95f4122 | 4382 | |
7b270f60 | 4383 | out_unlock: |
d95f4122 | 4384 | double_rq_unlock(rq, p_rq); |
7b270f60 | 4385 | out_irq: |
d95f4122 MG |
4386 | local_irq_restore(flags); |
4387 | ||
7b270f60 | 4388 | if (yielded > 0) |
d95f4122 MG |
4389 | schedule(); |
4390 | ||
4391 | return yielded; | |
4392 | } | |
4393 | EXPORT_SYMBOL_GPL(yield_to); | |
4394 | ||
1da177e4 | 4395 | /* |
41a2d6cf | 4396 | * This task is about to go to sleep on IO. Increment rq->nr_iowait so |
1da177e4 | 4397 | * that process accounting knows that this is a task in IO wait state. |
1da177e4 LT |
4398 | */ |
4399 | void __sched io_schedule(void) | |
4400 | { | |
54d35f29 | 4401 | struct rq *rq = raw_rq(); |
1da177e4 | 4402 | |
0ff92245 | 4403 | delayacct_blkio_start(); |
1da177e4 | 4404 | atomic_inc(&rq->nr_iowait); |
73c10101 | 4405 | blk_flush_plug(current); |
8f0dfc34 | 4406 | current->in_iowait = 1; |
1da177e4 | 4407 | schedule(); |
8f0dfc34 | 4408 | current->in_iowait = 0; |
1da177e4 | 4409 | atomic_dec(&rq->nr_iowait); |
0ff92245 | 4410 | delayacct_blkio_end(); |
1da177e4 | 4411 | } |
1da177e4 LT |
4412 | EXPORT_SYMBOL(io_schedule); |
4413 | ||
4414 | long __sched io_schedule_timeout(long timeout) | |
4415 | { | |
54d35f29 | 4416 | struct rq *rq = raw_rq(); |
1da177e4 LT |
4417 | long ret; |
4418 | ||
0ff92245 | 4419 | delayacct_blkio_start(); |
1da177e4 | 4420 | atomic_inc(&rq->nr_iowait); |
73c10101 | 4421 | blk_flush_plug(current); |
8f0dfc34 | 4422 | current->in_iowait = 1; |
1da177e4 | 4423 | ret = schedule_timeout(timeout); |
8f0dfc34 | 4424 | current->in_iowait = 0; |
1da177e4 | 4425 | atomic_dec(&rq->nr_iowait); |
0ff92245 | 4426 | delayacct_blkio_end(); |
1da177e4 LT |
4427 | return ret; |
4428 | } | |
4429 | ||
4430 | /** | |
4431 | * sys_sched_get_priority_max - return maximum RT priority. | |
4432 | * @policy: scheduling class. | |
4433 | * | |
e69f6186 YB |
4434 | * Return: On success, this syscall returns the maximum |
4435 | * rt_priority that can be used by a given scheduling class. | |
4436 | * On failure, a negative error code is returned. | |
1da177e4 | 4437 | */ |
5add95d4 | 4438 | SYSCALL_DEFINE1(sched_get_priority_max, int, policy) |
1da177e4 LT |
4439 | { |
4440 | int ret = -EINVAL; | |
4441 | ||
4442 | switch (policy) { | |
4443 | case SCHED_FIFO: | |
4444 | case SCHED_RR: | |
4445 | ret = MAX_USER_RT_PRIO-1; | |
4446 | break; | |
aab03e05 | 4447 | case SCHED_DEADLINE: |
1da177e4 | 4448 | case SCHED_NORMAL: |
b0a9499c | 4449 | case SCHED_BATCH: |
dd41f596 | 4450 | case SCHED_IDLE: |
1da177e4 LT |
4451 | ret = 0; |
4452 | break; | |
4453 | } | |
4454 | return ret; | |
4455 | } | |
4456 | ||
4457 | /** | |
4458 | * sys_sched_get_priority_min - return minimum RT priority. | |
4459 | * @policy: scheduling class. | |
4460 | * | |
e69f6186 YB |
4461 | * Return: On success, this syscall returns the minimum |
4462 | * rt_priority that can be used by a given scheduling class. | |
4463 | * On failure, a negative error code is returned. | |
1da177e4 | 4464 | */ |
5add95d4 | 4465 | SYSCALL_DEFINE1(sched_get_priority_min, int, policy) |
1da177e4 LT |
4466 | { |
4467 | int ret = -EINVAL; | |
4468 | ||
4469 | switch (policy) { | |
4470 | case SCHED_FIFO: | |
4471 | case SCHED_RR: | |
4472 | ret = 1; | |
4473 | break; | |
aab03e05 | 4474 | case SCHED_DEADLINE: |
1da177e4 | 4475 | case SCHED_NORMAL: |
b0a9499c | 4476 | case SCHED_BATCH: |
dd41f596 | 4477 | case SCHED_IDLE: |
1da177e4 LT |
4478 | ret = 0; |
4479 | } | |
4480 | return ret; | |
4481 | } | |
4482 | ||
4483 | /** | |
4484 | * sys_sched_rr_get_interval - return the default timeslice of a process. | |
4485 | * @pid: pid of the process. | |
4486 | * @interval: userspace pointer to the timeslice value. | |
4487 | * | |
4488 | * this syscall writes the default timeslice value of a given process | |
4489 | * into the user-space timespec buffer. A value of '0' means infinity. | |
e69f6186 YB |
4490 | * |
4491 | * Return: On success, 0 and the timeslice is in @interval. Otherwise, | |
4492 | * an error code. | |
1da177e4 | 4493 | */ |
17da2bd9 | 4494 | SYSCALL_DEFINE2(sched_rr_get_interval, pid_t, pid, |
754fe8d2 | 4495 | struct timespec __user *, interval) |
1da177e4 | 4496 | { |
36c8b586 | 4497 | struct task_struct *p; |
a4ec24b4 | 4498 | unsigned int time_slice; |
dba091b9 TG |
4499 | unsigned long flags; |
4500 | struct rq *rq; | |
3a5c359a | 4501 | int retval; |
1da177e4 | 4502 | struct timespec t; |
1da177e4 LT |
4503 | |
4504 | if (pid < 0) | |
3a5c359a | 4505 | return -EINVAL; |
1da177e4 LT |
4506 | |
4507 | retval = -ESRCH; | |
1a551ae7 | 4508 | rcu_read_lock(); |
1da177e4 LT |
4509 | p = find_process_by_pid(pid); |
4510 | if (!p) | |
4511 | goto out_unlock; | |
4512 | ||
4513 | retval = security_task_getscheduler(p); | |
4514 | if (retval) | |
4515 | goto out_unlock; | |
4516 | ||
dba091b9 | 4517 | rq = task_rq_lock(p, &flags); |
a57beec5 PZ |
4518 | time_slice = 0; |
4519 | if (p->sched_class->get_rr_interval) | |
4520 | time_slice = p->sched_class->get_rr_interval(rq, p); | |
0122ec5b | 4521 | task_rq_unlock(rq, p, &flags); |
a4ec24b4 | 4522 | |
1a551ae7 | 4523 | rcu_read_unlock(); |
a4ec24b4 | 4524 | jiffies_to_timespec(time_slice, &t); |
1da177e4 | 4525 | retval = copy_to_user(interval, &t, sizeof(t)) ? -EFAULT : 0; |
1da177e4 | 4526 | return retval; |
3a5c359a | 4527 | |
1da177e4 | 4528 | out_unlock: |
1a551ae7 | 4529 | rcu_read_unlock(); |
1da177e4 LT |
4530 | return retval; |
4531 | } | |
4532 | ||
7c731e0a | 4533 | static const char stat_nam[] = TASK_STATE_TO_CHAR_STR; |
36c8b586 | 4534 | |
82a1fcb9 | 4535 | void sched_show_task(struct task_struct *p) |
1da177e4 | 4536 | { |
1da177e4 | 4537 | unsigned long free = 0; |
4e79752c | 4538 | int ppid; |
1f8a7633 | 4539 | unsigned long state = p->state; |
1da177e4 | 4540 | |
1f8a7633 TH |
4541 | if (state) |
4542 | state = __ffs(state) + 1; | |
28d0686c | 4543 | printk(KERN_INFO "%-15.15s %c", p->comm, |
2ed6e34f | 4544 | state < sizeof(stat_nam) - 1 ? stat_nam[state] : '?'); |
4bd77321 | 4545 | #if BITS_PER_LONG == 32 |
1da177e4 | 4546 | if (state == TASK_RUNNING) |
3df0fc5b | 4547 | printk(KERN_CONT " running "); |
1da177e4 | 4548 | else |
3df0fc5b | 4549 | printk(KERN_CONT " %08lx ", thread_saved_pc(p)); |
1da177e4 LT |
4550 | #else |
4551 | if (state == TASK_RUNNING) | |
3df0fc5b | 4552 | printk(KERN_CONT " running task "); |
1da177e4 | 4553 | else |
3df0fc5b | 4554 | printk(KERN_CONT " %016lx ", thread_saved_pc(p)); |
1da177e4 LT |
4555 | #endif |
4556 | #ifdef CONFIG_DEBUG_STACK_USAGE | |
7c9f8861 | 4557 | free = stack_not_used(p); |
1da177e4 | 4558 | #endif |
a90e984c | 4559 | ppid = 0; |
4e79752c | 4560 | rcu_read_lock(); |
a90e984c ON |
4561 | if (pid_alive(p)) |
4562 | ppid = task_pid_nr(rcu_dereference(p->real_parent)); | |
4e79752c | 4563 | rcu_read_unlock(); |
3df0fc5b | 4564 | printk(KERN_CONT "%5lu %5d %6d 0x%08lx\n", free, |
4e79752c | 4565 | task_pid_nr(p), ppid, |
aa47b7e0 | 4566 | (unsigned long)task_thread_info(p)->flags); |
1da177e4 | 4567 | |
3d1cb205 | 4568 | print_worker_info(KERN_INFO, p); |
5fb5e6de | 4569 | show_stack(p, NULL); |
1da177e4 LT |
4570 | } |
4571 | ||
e59e2ae2 | 4572 | void show_state_filter(unsigned long state_filter) |
1da177e4 | 4573 | { |
36c8b586 | 4574 | struct task_struct *g, *p; |
1da177e4 | 4575 | |
4bd77321 | 4576 | #if BITS_PER_LONG == 32 |
3df0fc5b PZ |
4577 | printk(KERN_INFO |
4578 | " task PC stack pid father\n"); | |
1da177e4 | 4579 | #else |
3df0fc5b PZ |
4580 | printk(KERN_INFO |
4581 | " task PC stack pid father\n"); | |
1da177e4 | 4582 | #endif |
510f5acc | 4583 | rcu_read_lock(); |
5d07f420 | 4584 | for_each_process_thread(g, p) { |
1da177e4 LT |
4585 | /* |
4586 | * reset the NMI-timeout, listing all files on a slow | |
25985edc | 4587 | * console might take a lot of time: |
1da177e4 LT |
4588 | */ |
4589 | touch_nmi_watchdog(); | |
39bc89fd | 4590 | if (!state_filter || (p->state & state_filter)) |
82a1fcb9 | 4591 | sched_show_task(p); |
5d07f420 | 4592 | } |
1da177e4 | 4593 | |
04c9167f JF |
4594 | touch_all_softlockup_watchdogs(); |
4595 | ||
dd41f596 IM |
4596 | #ifdef CONFIG_SCHED_DEBUG |
4597 | sysrq_sched_debug_show(); | |
4598 | #endif | |
510f5acc | 4599 | rcu_read_unlock(); |
e59e2ae2 IM |
4600 | /* |
4601 | * Only show locks if all tasks are dumped: | |
4602 | */ | |
93335a21 | 4603 | if (!state_filter) |
e59e2ae2 | 4604 | debug_show_all_locks(); |
1da177e4 LT |
4605 | } |
4606 | ||
0db0628d | 4607 | void init_idle_bootup_task(struct task_struct *idle) |
1df21055 | 4608 | { |
dd41f596 | 4609 | idle->sched_class = &idle_sched_class; |
1df21055 IM |
4610 | } |
4611 | ||
f340c0d1 IM |
4612 | /** |
4613 | * init_idle - set up an idle thread for a given CPU | |
4614 | * @idle: task in question | |
4615 | * @cpu: cpu the idle task belongs to | |
4616 | * | |
4617 | * NOTE: this function does not set the idle thread's NEED_RESCHED | |
4618 | * flag, to make booting more robust. | |
4619 | */ | |
0db0628d | 4620 | void init_idle(struct task_struct *idle, int cpu) |
1da177e4 | 4621 | { |
70b97a7f | 4622 | struct rq *rq = cpu_rq(cpu); |
1da177e4 LT |
4623 | unsigned long flags; |
4624 | ||
05fa785c | 4625 | raw_spin_lock_irqsave(&rq->lock, flags); |
5cbd54ef | 4626 | |
5e1576ed | 4627 | __sched_fork(0, idle); |
06b83b5f | 4628 | idle->state = TASK_RUNNING; |
dd41f596 IM |
4629 | idle->se.exec_start = sched_clock(); |
4630 | ||
1e1b6c51 | 4631 | do_set_cpus_allowed(idle, cpumask_of(cpu)); |
6506cf6c PZ |
4632 | /* |
4633 | * We're having a chicken and egg problem, even though we are | |
4634 | * holding rq->lock, the cpu isn't yet set to this cpu so the | |
4635 | * lockdep check in task_group() will fail. | |
4636 | * | |
4637 | * Similar case to sched_fork(). / Alternatively we could | |
4638 | * use task_rq_lock() here and obtain the other rq->lock. | |
4639 | * | |
4640 | * Silence PROVE_RCU | |
4641 | */ | |
4642 | rcu_read_lock(); | |
dd41f596 | 4643 | __set_task_cpu(idle, cpu); |
6506cf6c | 4644 | rcu_read_unlock(); |
1da177e4 | 4645 | |
1da177e4 | 4646 | rq->curr = rq->idle = idle; |
da0c1e65 | 4647 | idle->on_rq = TASK_ON_RQ_QUEUED; |
3ca7a440 PZ |
4648 | #if defined(CONFIG_SMP) |
4649 | idle->on_cpu = 1; | |
4866cde0 | 4650 | #endif |
05fa785c | 4651 | raw_spin_unlock_irqrestore(&rq->lock, flags); |
1da177e4 LT |
4652 | |
4653 | /* Set the preempt count _outside_ the spinlocks! */ | |
01028747 | 4654 | init_idle_preempt_count(idle, cpu); |
55cd5340 | 4655 | |
dd41f596 IM |
4656 | /* |
4657 | * The idle tasks have their own, simple scheduling class: | |
4658 | */ | |
4659 | idle->sched_class = &idle_sched_class; | |
868baf07 | 4660 | ftrace_graph_init_idle_task(idle, cpu); |
45eacc69 | 4661 | vtime_init_idle(idle, cpu); |
f1c6f1a7 CE |
4662 | #if defined(CONFIG_SMP) |
4663 | sprintf(idle->comm, "%s/%d", INIT_TASK_COMM, cpu); | |
4664 | #endif | |
19978ca6 IM |
4665 | } |
4666 | ||
f82f8042 JL |
4667 | int cpuset_cpumask_can_shrink(const struct cpumask *cur, |
4668 | const struct cpumask *trial) | |
4669 | { | |
4670 | int ret = 1, trial_cpus; | |
4671 | struct dl_bw *cur_dl_b; | |
4672 | unsigned long flags; | |
4673 | ||
bb2bc55a MG |
4674 | if (!cpumask_weight(cur)) |
4675 | return ret; | |
4676 | ||
75e23e49 | 4677 | rcu_read_lock_sched(); |
f82f8042 JL |
4678 | cur_dl_b = dl_bw_of(cpumask_any(cur)); |
4679 | trial_cpus = cpumask_weight(trial); | |
4680 | ||
4681 | raw_spin_lock_irqsave(&cur_dl_b->lock, flags); | |
4682 | if (cur_dl_b->bw != -1 && | |
4683 | cur_dl_b->bw * trial_cpus < cur_dl_b->total_bw) | |
4684 | ret = 0; | |
4685 | raw_spin_unlock_irqrestore(&cur_dl_b->lock, flags); | |
75e23e49 | 4686 | rcu_read_unlock_sched(); |
f82f8042 JL |
4687 | |
4688 | return ret; | |
4689 | } | |
4690 | ||
7f51412a JL |
4691 | int task_can_attach(struct task_struct *p, |
4692 | const struct cpumask *cs_cpus_allowed) | |
4693 | { | |
4694 | int ret = 0; | |
4695 | ||
4696 | /* | |
4697 | * Kthreads which disallow setaffinity shouldn't be moved | |
4698 | * to a new cpuset; we don't want to change their cpu | |
4699 | * affinity and isolating such threads by their set of | |
4700 | * allowed nodes is unnecessary. Thus, cpusets are not | |
4701 | * applicable for such threads. This prevents checking for | |
4702 | * success of set_cpus_allowed_ptr() on all attached tasks | |
4703 | * before cpus_allowed may be changed. | |
4704 | */ | |
4705 | if (p->flags & PF_NO_SETAFFINITY) { | |
4706 | ret = -EINVAL; | |
4707 | goto out; | |
4708 | } | |
4709 | ||
4710 | #ifdef CONFIG_SMP | |
4711 | if (dl_task(p) && !cpumask_intersects(task_rq(p)->rd->span, | |
4712 | cs_cpus_allowed)) { | |
4713 | unsigned int dest_cpu = cpumask_any_and(cpu_active_mask, | |
4714 | cs_cpus_allowed); | |
75e23e49 | 4715 | struct dl_bw *dl_b; |
7f51412a JL |
4716 | bool overflow; |
4717 | int cpus; | |
4718 | unsigned long flags; | |
4719 | ||
75e23e49 JL |
4720 | rcu_read_lock_sched(); |
4721 | dl_b = dl_bw_of(dest_cpu); | |
7f51412a JL |
4722 | raw_spin_lock_irqsave(&dl_b->lock, flags); |
4723 | cpus = dl_bw_cpus(dest_cpu); | |
4724 | overflow = __dl_overflow(dl_b, cpus, 0, p->dl.dl_bw); | |
4725 | if (overflow) | |
4726 | ret = -EBUSY; | |
4727 | else { | |
4728 | /* | |
4729 | * We reserve space for this task in the destination | |
4730 | * root_domain, as we can't fail after this point. | |
4731 | * We will free resources in the source root_domain | |
4732 | * later on (see set_cpus_allowed_dl()). | |
4733 | */ | |
4734 | __dl_add(dl_b, p->dl.dl_bw); | |
4735 | } | |
4736 | raw_spin_unlock_irqrestore(&dl_b->lock, flags); | |
75e23e49 | 4737 | rcu_read_unlock_sched(); |
7f51412a JL |
4738 | |
4739 | } | |
4740 | #endif | |
4741 | out: | |
4742 | return ret; | |
4743 | } | |
4744 | ||
1da177e4 | 4745 | #ifdef CONFIG_SMP |
a15b12ac KT |
4746 | /* |
4747 | * move_queued_task - move a queued task to new rq. | |
4748 | * | |
4749 | * Returns (locked) new rq. Old rq's lock is released. | |
4750 | */ | |
4751 | static struct rq *move_queued_task(struct task_struct *p, int new_cpu) | |
4752 | { | |
4753 | struct rq *rq = task_rq(p); | |
4754 | ||
4755 | lockdep_assert_held(&rq->lock); | |
4756 | ||
4757 | dequeue_task(rq, p, 0); | |
4758 | p->on_rq = TASK_ON_RQ_MIGRATING; | |
4759 | set_task_cpu(p, new_cpu); | |
4760 | raw_spin_unlock(&rq->lock); | |
4761 | ||
4762 | rq = cpu_rq(new_cpu); | |
4763 | ||
4764 | raw_spin_lock(&rq->lock); | |
4765 | BUG_ON(task_cpu(p) != new_cpu); | |
4766 | p->on_rq = TASK_ON_RQ_QUEUED; | |
4767 | enqueue_task(rq, p, 0); | |
4768 | check_preempt_curr(rq, p, 0); | |
4769 | ||
4770 | return rq; | |
4771 | } | |
4772 | ||
1e1b6c51 KM |
4773 | void do_set_cpus_allowed(struct task_struct *p, const struct cpumask *new_mask) |
4774 | { | |
1b537c7d | 4775 | if (p->sched_class->set_cpus_allowed) |
1e1b6c51 | 4776 | p->sched_class->set_cpus_allowed(p, new_mask); |
4939602a PZ |
4777 | |
4778 | cpumask_copy(&p->cpus_allowed, new_mask); | |
29baa747 | 4779 | p->nr_cpus_allowed = cpumask_weight(new_mask); |
1e1b6c51 KM |
4780 | } |
4781 | ||
1da177e4 LT |
4782 | /* |
4783 | * This is how migration works: | |
4784 | * | |
969c7921 TH |
4785 | * 1) we invoke migration_cpu_stop() on the target CPU using |
4786 | * stop_one_cpu(). | |
4787 | * 2) stopper starts to run (implicitly forcing the migrated thread | |
4788 | * off the CPU) | |
4789 | * 3) it checks whether the migrated task is still in the wrong runqueue. | |
4790 | * 4) if it's in the wrong runqueue then the migration thread removes | |
1da177e4 | 4791 | * it and puts it into the right queue. |
969c7921 TH |
4792 | * 5) stopper completes and stop_one_cpu() returns and the migration |
4793 | * is done. | |
1da177e4 LT |
4794 | */ |
4795 | ||
4796 | /* | |
4797 | * Change a given task's CPU affinity. Migrate the thread to a | |
4798 | * proper CPU and schedule it away if the CPU it's executing on | |
4799 | * is removed from the allowed bitmask. | |
4800 | * | |
4801 | * NOTE: the caller must have a valid reference to the task, the | |
41a2d6cf | 4802 | * task must not exit() & deallocate itself prematurely. The |
1da177e4 LT |
4803 | * call is not atomic; no spinlocks may be held. |
4804 | */ | |
96f874e2 | 4805 | int set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask) |
1da177e4 LT |
4806 | { |
4807 | unsigned long flags; | |
70b97a7f | 4808 | struct rq *rq; |
969c7921 | 4809 | unsigned int dest_cpu; |
48f24c4d | 4810 | int ret = 0; |
1da177e4 LT |
4811 | |
4812 | rq = task_rq_lock(p, &flags); | |
e2912009 | 4813 | |
db44fc01 YZ |
4814 | if (cpumask_equal(&p->cpus_allowed, new_mask)) |
4815 | goto out; | |
4816 | ||
6ad4c188 | 4817 | if (!cpumask_intersects(new_mask, cpu_active_mask)) { |
1da177e4 LT |
4818 | ret = -EINVAL; |
4819 | goto out; | |
4820 | } | |
4821 | ||
1e1b6c51 | 4822 | do_set_cpus_allowed(p, new_mask); |
73fe6aae | 4823 | |
1da177e4 | 4824 | /* Can the task run on the task's current CPU? If so, we're done */ |
96f874e2 | 4825 | if (cpumask_test_cpu(task_cpu(p), new_mask)) |
1da177e4 LT |
4826 | goto out; |
4827 | ||
969c7921 | 4828 | dest_cpu = cpumask_any_and(cpu_active_mask, new_mask); |
a15b12ac | 4829 | if (task_running(rq, p) || p->state == TASK_WAKING) { |
969c7921 | 4830 | struct migration_arg arg = { p, dest_cpu }; |
1da177e4 | 4831 | /* Need help from migration thread: drop lock and wait. */ |
0122ec5b | 4832 | task_rq_unlock(rq, p, &flags); |
969c7921 | 4833 | stop_one_cpu(cpu_of(rq), migration_cpu_stop, &arg); |
1da177e4 LT |
4834 | tlb_migrate_finish(p->mm); |
4835 | return 0; | |
a15b12ac KT |
4836 | } else if (task_on_rq_queued(p)) |
4837 | rq = move_queued_task(p, dest_cpu); | |
1da177e4 | 4838 | out: |
0122ec5b | 4839 | task_rq_unlock(rq, p, &flags); |
48f24c4d | 4840 | |
1da177e4 LT |
4841 | return ret; |
4842 | } | |
cd8ba7cd | 4843 | EXPORT_SYMBOL_GPL(set_cpus_allowed_ptr); |
1da177e4 LT |
4844 | |
4845 | /* | |
41a2d6cf | 4846 | * Move (not current) task off this cpu, onto dest cpu. We're doing |
1da177e4 LT |
4847 | * this because either it can't run here any more (set_cpus_allowed() |
4848 | * away from this CPU, or CPU going down), or because we're | |
4849 | * attempting to rebalance this task on exec (sched_exec). | |
4850 | * | |
4851 | * So we race with normal scheduler movements, but that's OK, as long | |
4852 | * as the task is no longer on this CPU. | |
efc30814 KK |
4853 | * |
4854 | * Returns non-zero if task was successfully migrated. | |
1da177e4 | 4855 | */ |
efc30814 | 4856 | static int __migrate_task(struct task_struct *p, int src_cpu, int dest_cpu) |
1da177e4 | 4857 | { |
a1e01829 | 4858 | struct rq *rq; |
e2912009 | 4859 | int ret = 0; |
1da177e4 | 4860 | |
e761b772 | 4861 | if (unlikely(!cpu_active(dest_cpu))) |
efc30814 | 4862 | return ret; |
1da177e4 | 4863 | |
a1e01829 | 4864 | rq = cpu_rq(src_cpu); |
1da177e4 | 4865 | |
0122ec5b | 4866 | raw_spin_lock(&p->pi_lock); |
a1e01829 | 4867 | raw_spin_lock(&rq->lock); |
1da177e4 LT |
4868 | /* Already moved. */ |
4869 | if (task_cpu(p) != src_cpu) | |
b1e38734 | 4870 | goto done; |
a1e01829 | 4871 | |
1da177e4 | 4872 | /* Affinity changed (again). */ |
fa17b507 | 4873 | if (!cpumask_test_cpu(dest_cpu, tsk_cpus_allowed(p))) |
b1e38734 | 4874 | goto fail; |
1da177e4 | 4875 | |
e2912009 PZ |
4876 | /* |
4877 | * If we're not on a rq, the next wake-up will ensure we're | |
4878 | * placed properly. | |
4879 | */ | |
a15b12ac KT |
4880 | if (task_on_rq_queued(p)) |
4881 | rq = move_queued_task(p, dest_cpu); | |
b1e38734 | 4882 | done: |
efc30814 | 4883 | ret = 1; |
b1e38734 | 4884 | fail: |
a1e01829 | 4885 | raw_spin_unlock(&rq->lock); |
0122ec5b | 4886 | raw_spin_unlock(&p->pi_lock); |
efc30814 | 4887 | return ret; |
1da177e4 LT |
4888 | } |
4889 | ||
e6628d5b MG |
4890 | #ifdef CONFIG_NUMA_BALANCING |
4891 | /* Migrate current task p to target_cpu */ | |
4892 | int migrate_task_to(struct task_struct *p, int target_cpu) | |
4893 | { | |
4894 | struct migration_arg arg = { p, target_cpu }; | |
4895 | int curr_cpu = task_cpu(p); | |
4896 | ||
4897 | if (curr_cpu == target_cpu) | |
4898 | return 0; | |
4899 | ||
4900 | if (!cpumask_test_cpu(target_cpu, tsk_cpus_allowed(p))) | |
4901 | return -EINVAL; | |
4902 | ||
4903 | /* TODO: This is not properly updating schedstats */ | |
4904 | ||
286549dc | 4905 | trace_sched_move_numa(p, curr_cpu, target_cpu); |
e6628d5b MG |
4906 | return stop_one_cpu(curr_cpu, migration_cpu_stop, &arg); |
4907 | } | |
0ec8aa00 PZ |
4908 | |
4909 | /* | |
4910 | * Requeue a task on a given node and accurately track the number of NUMA | |
4911 | * tasks on the runqueues | |
4912 | */ | |
4913 | void sched_setnuma(struct task_struct *p, int nid) | |
4914 | { | |
4915 | struct rq *rq; | |
4916 | unsigned long flags; | |
da0c1e65 | 4917 | bool queued, running; |
0ec8aa00 PZ |
4918 | |
4919 | rq = task_rq_lock(p, &flags); | |
da0c1e65 | 4920 | queued = task_on_rq_queued(p); |
0ec8aa00 PZ |
4921 | running = task_current(rq, p); |
4922 | ||
da0c1e65 | 4923 | if (queued) |
0ec8aa00 PZ |
4924 | dequeue_task(rq, p, 0); |
4925 | if (running) | |
f3cd1c4e | 4926 | put_prev_task(rq, p); |
0ec8aa00 PZ |
4927 | |
4928 | p->numa_preferred_nid = nid; | |
0ec8aa00 PZ |
4929 | |
4930 | if (running) | |
4931 | p->sched_class->set_curr_task(rq); | |
da0c1e65 | 4932 | if (queued) |
0ec8aa00 PZ |
4933 | enqueue_task(rq, p, 0); |
4934 | task_rq_unlock(rq, p, &flags); | |
4935 | } | |
e6628d5b MG |
4936 | #endif |
4937 | ||
1da177e4 | 4938 | /* |
969c7921 TH |
4939 | * migration_cpu_stop - this will be executed by a highprio stopper thread |
4940 | * and performs thread migration by bumping thread off CPU then | |
4941 | * 'pushing' onto another runqueue. | |
1da177e4 | 4942 | */ |
969c7921 | 4943 | static int migration_cpu_stop(void *data) |
1da177e4 | 4944 | { |
969c7921 | 4945 | struct migration_arg *arg = data; |
f7b4cddc | 4946 | |
969c7921 TH |
4947 | /* |
4948 | * The original target cpu might have gone down and we might | |
4949 | * be on another cpu but it doesn't matter. | |
4950 | */ | |
f7b4cddc | 4951 | local_irq_disable(); |
5cd038f5 LJ |
4952 | /* |
4953 | * We need to explicitly wake pending tasks before running | |
4954 | * __migrate_task() such that we will not miss enforcing cpus_allowed | |
4955 | * during wakeups, see set_cpus_allowed_ptr()'s TASK_WAKING test. | |
4956 | */ | |
4957 | sched_ttwu_pending(); | |
969c7921 | 4958 | __migrate_task(arg->task, raw_smp_processor_id(), arg->dest_cpu); |
f7b4cddc | 4959 | local_irq_enable(); |
1da177e4 | 4960 | return 0; |
f7b4cddc ON |
4961 | } |
4962 | ||
1da177e4 | 4963 | #ifdef CONFIG_HOTPLUG_CPU |
48c5ccae | 4964 | |
054b9108 | 4965 | /* |
48c5ccae PZ |
4966 | * Ensures that the idle task is using init_mm right before its cpu goes |
4967 | * offline. | |
054b9108 | 4968 | */ |
48c5ccae | 4969 | void idle_task_exit(void) |
1da177e4 | 4970 | { |
48c5ccae | 4971 | struct mm_struct *mm = current->active_mm; |
e76bd8d9 | 4972 | |
48c5ccae | 4973 | BUG_ON(cpu_online(smp_processor_id())); |
e76bd8d9 | 4974 | |
a53efe5f | 4975 | if (mm != &init_mm) { |
48c5ccae | 4976 | switch_mm(mm, &init_mm, current); |
a53efe5f MS |
4977 | finish_arch_post_lock_switch(); |
4978 | } | |
48c5ccae | 4979 | mmdrop(mm); |
1da177e4 LT |
4980 | } |
4981 | ||
4982 | /* | |
5d180232 PZ |
4983 | * Since this CPU is going 'away' for a while, fold any nr_active delta |
4984 | * we might have. Assumes we're called after migrate_tasks() so that the | |
4985 | * nr_active count is stable. | |
4986 | * | |
4987 | * Also see the comment "Global load-average calculations". | |
1da177e4 | 4988 | */ |
5d180232 | 4989 | static void calc_load_migrate(struct rq *rq) |
1da177e4 | 4990 | { |
5d180232 PZ |
4991 | long delta = calc_load_fold_active(rq); |
4992 | if (delta) | |
4993 | atomic_long_add(delta, &calc_load_tasks); | |
1da177e4 LT |
4994 | } |
4995 | ||
3f1d2a31 PZ |
4996 | static void put_prev_task_fake(struct rq *rq, struct task_struct *prev) |
4997 | { | |
4998 | } | |
4999 | ||
5000 | static const struct sched_class fake_sched_class = { | |
5001 | .put_prev_task = put_prev_task_fake, | |
5002 | }; | |
5003 | ||
5004 | static struct task_struct fake_task = { | |
5005 | /* | |
5006 | * Avoid pull_{rt,dl}_task() | |
5007 | */ | |
5008 | .prio = MAX_PRIO + 1, | |
5009 | .sched_class = &fake_sched_class, | |
5010 | }; | |
5011 | ||
48f24c4d | 5012 | /* |
48c5ccae PZ |
5013 | * Migrate all tasks from the rq, sleeping tasks will be migrated by |
5014 | * try_to_wake_up()->select_task_rq(). | |
5015 | * | |
5016 | * Called with rq->lock held even though we'er in stop_machine() and | |
5017 | * there's no concurrency possible, we hold the required locks anyway | |
5018 | * because of lock validation efforts. | |
1da177e4 | 5019 | */ |
48c5ccae | 5020 | static void migrate_tasks(unsigned int dead_cpu) |
1da177e4 | 5021 | { |
70b97a7f | 5022 | struct rq *rq = cpu_rq(dead_cpu); |
48c5ccae PZ |
5023 | struct task_struct *next, *stop = rq->stop; |
5024 | int dest_cpu; | |
1da177e4 LT |
5025 | |
5026 | /* | |
48c5ccae PZ |
5027 | * Fudge the rq selection such that the below task selection loop |
5028 | * doesn't get stuck on the currently eligible stop task. | |
5029 | * | |
5030 | * We're currently inside stop_machine() and the rq is either stuck | |
5031 | * in the stop_machine_cpu_stop() loop, or we're executing this code, | |
5032 | * either way we should never end up calling schedule() until we're | |
5033 | * done here. | |
1da177e4 | 5034 | */ |
48c5ccae | 5035 | rq->stop = NULL; |
48f24c4d | 5036 | |
77bd3970 FW |
5037 | /* |
5038 | * put_prev_task() and pick_next_task() sched | |
5039 | * class method both need to have an up-to-date | |
5040 | * value of rq->clock[_task] | |
5041 | */ | |
5042 | update_rq_clock(rq); | |
5043 | ||
dd41f596 | 5044 | for ( ; ; ) { |
48c5ccae PZ |
5045 | /* |
5046 | * There's this thread running, bail when that's the only | |
5047 | * remaining thread. | |
5048 | */ | |
5049 | if (rq->nr_running == 1) | |
dd41f596 | 5050 | break; |
48c5ccae | 5051 | |
3f1d2a31 | 5052 | next = pick_next_task(rq, &fake_task); |
48c5ccae | 5053 | BUG_ON(!next); |
79c53799 | 5054 | next->sched_class->put_prev_task(rq, next); |
e692ab53 | 5055 | |
48c5ccae PZ |
5056 | /* Find suitable destination for @next, with force if needed. */ |
5057 | dest_cpu = select_fallback_rq(dead_cpu, next); | |
5058 | raw_spin_unlock(&rq->lock); | |
5059 | ||
5060 | __migrate_task(next, dead_cpu, dest_cpu); | |
5061 | ||
5062 | raw_spin_lock(&rq->lock); | |
1da177e4 | 5063 | } |
dce48a84 | 5064 | |
48c5ccae | 5065 | rq->stop = stop; |
dce48a84 | 5066 | } |
48c5ccae | 5067 | |
1da177e4 LT |
5068 | #endif /* CONFIG_HOTPLUG_CPU */ |
5069 | ||
e692ab53 NP |
5070 | #if defined(CONFIG_SCHED_DEBUG) && defined(CONFIG_SYSCTL) |
5071 | ||
5072 | static struct ctl_table sd_ctl_dir[] = { | |
e0361851 AD |
5073 | { |
5074 | .procname = "sched_domain", | |
c57baf1e | 5075 | .mode = 0555, |
e0361851 | 5076 | }, |
56992309 | 5077 | {} |
e692ab53 NP |
5078 | }; |
5079 | ||
5080 | static struct ctl_table sd_ctl_root[] = { | |
e0361851 AD |
5081 | { |
5082 | .procname = "kernel", | |
c57baf1e | 5083 | .mode = 0555, |
e0361851 AD |
5084 | .child = sd_ctl_dir, |
5085 | }, | |
56992309 | 5086 | {} |
e692ab53 NP |
5087 | }; |
5088 | ||
5089 | static struct ctl_table *sd_alloc_ctl_entry(int n) | |
5090 | { | |
5091 | struct ctl_table *entry = | |
5cf9f062 | 5092 | kcalloc(n, sizeof(struct ctl_table), GFP_KERNEL); |
e692ab53 | 5093 | |
e692ab53 NP |
5094 | return entry; |
5095 | } | |
5096 | ||
6382bc90 MM |
5097 | static void sd_free_ctl_entry(struct ctl_table **tablep) |
5098 | { | |
cd790076 | 5099 | struct ctl_table *entry; |
6382bc90 | 5100 | |
cd790076 MM |
5101 | /* |
5102 | * In the intermediate directories, both the child directory and | |
5103 | * procname are dynamically allocated and could fail but the mode | |
41a2d6cf | 5104 | * will always be set. In the lowest directory the names are |
cd790076 MM |
5105 | * static strings and all have proc handlers. |
5106 | */ | |
5107 | for (entry = *tablep; entry->mode; entry++) { | |
6382bc90 MM |
5108 | if (entry->child) |
5109 | sd_free_ctl_entry(&entry->child); | |
cd790076 MM |
5110 | if (entry->proc_handler == NULL) |
5111 | kfree(entry->procname); | |
5112 | } | |
6382bc90 MM |
5113 | |
5114 | kfree(*tablep); | |
5115 | *tablep = NULL; | |
5116 | } | |
5117 | ||
201c373e | 5118 | static int min_load_idx = 0; |
fd9b86d3 | 5119 | static int max_load_idx = CPU_LOAD_IDX_MAX-1; |
201c373e | 5120 | |
e692ab53 | 5121 | static void |
e0361851 | 5122 | set_table_entry(struct ctl_table *entry, |
e692ab53 | 5123 | const char *procname, void *data, int maxlen, |
201c373e NK |
5124 | umode_t mode, proc_handler *proc_handler, |
5125 | bool load_idx) | |
e692ab53 | 5126 | { |
e692ab53 NP |
5127 | entry->procname = procname; |
5128 | entry->data = data; | |
5129 | entry->maxlen = maxlen; | |
5130 | entry->mode = mode; | |
5131 | entry->proc_handler = proc_handler; | |
201c373e NK |
5132 | |
5133 | if (load_idx) { | |
5134 | entry->extra1 = &min_load_idx; | |
5135 | entry->extra2 = &max_load_idx; | |
5136 | } | |
e692ab53 NP |
5137 | } |
5138 | ||
5139 | static struct ctl_table * | |
5140 | sd_alloc_ctl_domain_table(struct sched_domain *sd) | |
5141 | { | |
37e6bae8 | 5142 | struct ctl_table *table = sd_alloc_ctl_entry(14); |
e692ab53 | 5143 | |
ad1cdc1d MM |
5144 | if (table == NULL) |
5145 | return NULL; | |
5146 | ||
e0361851 | 5147 | set_table_entry(&table[0], "min_interval", &sd->min_interval, |
201c373e | 5148 | sizeof(long), 0644, proc_doulongvec_minmax, false); |
e0361851 | 5149 | set_table_entry(&table[1], "max_interval", &sd->max_interval, |
201c373e | 5150 | sizeof(long), 0644, proc_doulongvec_minmax, false); |
e0361851 | 5151 | set_table_entry(&table[2], "busy_idx", &sd->busy_idx, |
201c373e | 5152 | sizeof(int), 0644, proc_dointvec_minmax, true); |
e0361851 | 5153 | set_table_entry(&table[3], "idle_idx", &sd->idle_idx, |
201c373e | 5154 | sizeof(int), 0644, proc_dointvec_minmax, true); |
e0361851 | 5155 | set_table_entry(&table[4], "newidle_idx", &sd->newidle_idx, |
201c373e | 5156 | sizeof(int), 0644, proc_dointvec_minmax, true); |
e0361851 | 5157 | set_table_entry(&table[5], "wake_idx", &sd->wake_idx, |
201c373e | 5158 | sizeof(int), 0644, proc_dointvec_minmax, true); |
e0361851 | 5159 | set_table_entry(&table[6], "forkexec_idx", &sd->forkexec_idx, |
201c373e | 5160 | sizeof(int), 0644, proc_dointvec_minmax, true); |
e0361851 | 5161 | set_table_entry(&table[7], "busy_factor", &sd->busy_factor, |
201c373e | 5162 | sizeof(int), 0644, proc_dointvec_minmax, false); |
e0361851 | 5163 | set_table_entry(&table[8], "imbalance_pct", &sd->imbalance_pct, |
201c373e | 5164 | sizeof(int), 0644, proc_dointvec_minmax, false); |
ace8b3d6 | 5165 | set_table_entry(&table[9], "cache_nice_tries", |
e692ab53 | 5166 | &sd->cache_nice_tries, |
201c373e | 5167 | sizeof(int), 0644, proc_dointvec_minmax, false); |
ace8b3d6 | 5168 | set_table_entry(&table[10], "flags", &sd->flags, |
201c373e | 5169 | sizeof(int), 0644, proc_dointvec_minmax, false); |
37e6bae8 AS |
5170 | set_table_entry(&table[11], "max_newidle_lb_cost", |
5171 | &sd->max_newidle_lb_cost, | |
5172 | sizeof(long), 0644, proc_doulongvec_minmax, false); | |
5173 | set_table_entry(&table[12], "name", sd->name, | |
201c373e | 5174 | CORENAME_MAX_SIZE, 0444, proc_dostring, false); |
37e6bae8 | 5175 | /* &table[13] is terminator */ |
e692ab53 NP |
5176 | |
5177 | return table; | |
5178 | } | |
5179 | ||
be7002e6 | 5180 | static struct ctl_table *sd_alloc_ctl_cpu_table(int cpu) |
e692ab53 NP |
5181 | { |
5182 | struct ctl_table *entry, *table; | |
5183 | struct sched_domain *sd; | |
5184 | int domain_num = 0, i; | |
5185 | char buf[32]; | |
5186 | ||
5187 | for_each_domain(cpu, sd) | |
5188 | domain_num++; | |
5189 | entry = table = sd_alloc_ctl_entry(domain_num + 1); | |
ad1cdc1d MM |
5190 | if (table == NULL) |
5191 | return NULL; | |
e692ab53 NP |
5192 | |
5193 | i = 0; | |
5194 | for_each_domain(cpu, sd) { | |
5195 | snprintf(buf, 32, "domain%d", i); | |
e692ab53 | 5196 | entry->procname = kstrdup(buf, GFP_KERNEL); |
c57baf1e | 5197 | entry->mode = 0555; |
e692ab53 NP |
5198 | entry->child = sd_alloc_ctl_domain_table(sd); |
5199 | entry++; | |
5200 | i++; | |
5201 | } | |
5202 | return table; | |
5203 | } | |
5204 | ||
5205 | static struct ctl_table_header *sd_sysctl_header; | |
6382bc90 | 5206 | static void register_sched_domain_sysctl(void) |
e692ab53 | 5207 | { |
6ad4c188 | 5208 | int i, cpu_num = num_possible_cpus(); |
e692ab53 NP |
5209 | struct ctl_table *entry = sd_alloc_ctl_entry(cpu_num + 1); |
5210 | char buf[32]; | |
5211 | ||
7378547f MM |
5212 | WARN_ON(sd_ctl_dir[0].child); |
5213 | sd_ctl_dir[0].child = entry; | |
5214 | ||
ad1cdc1d MM |
5215 | if (entry == NULL) |
5216 | return; | |
5217 | ||
6ad4c188 | 5218 | for_each_possible_cpu(i) { |
e692ab53 | 5219 | snprintf(buf, 32, "cpu%d", i); |
e692ab53 | 5220 | entry->procname = kstrdup(buf, GFP_KERNEL); |
c57baf1e | 5221 | entry->mode = 0555; |
e692ab53 | 5222 | entry->child = sd_alloc_ctl_cpu_table(i); |
97b6ea7b | 5223 | entry++; |
e692ab53 | 5224 | } |
7378547f MM |
5225 | |
5226 | WARN_ON(sd_sysctl_header); | |
e692ab53 NP |
5227 | sd_sysctl_header = register_sysctl_table(sd_ctl_root); |
5228 | } | |
6382bc90 | 5229 | |
7378547f | 5230 | /* may be called multiple times per register */ |
6382bc90 MM |
5231 | static void unregister_sched_domain_sysctl(void) |
5232 | { | |
7378547f MM |
5233 | if (sd_sysctl_header) |
5234 | unregister_sysctl_table(sd_sysctl_header); | |
6382bc90 | 5235 | sd_sysctl_header = NULL; |
7378547f MM |
5236 | if (sd_ctl_dir[0].child) |
5237 | sd_free_ctl_entry(&sd_ctl_dir[0].child); | |
6382bc90 | 5238 | } |
e692ab53 | 5239 | #else |
6382bc90 MM |
5240 | static void register_sched_domain_sysctl(void) |
5241 | { | |
5242 | } | |
5243 | static void unregister_sched_domain_sysctl(void) | |
e692ab53 NP |
5244 | { |
5245 | } | |
5246 | #endif | |
5247 | ||
1f11eb6a GH |
5248 | static void set_rq_online(struct rq *rq) |
5249 | { | |
5250 | if (!rq->online) { | |
5251 | const struct sched_class *class; | |
5252 | ||
c6c4927b | 5253 | cpumask_set_cpu(rq->cpu, rq->rd->online); |
1f11eb6a GH |
5254 | rq->online = 1; |
5255 | ||
5256 | for_each_class(class) { | |
5257 | if (class->rq_online) | |
5258 | class->rq_online(rq); | |
5259 | } | |
5260 | } | |
5261 | } | |
5262 | ||
5263 | static void set_rq_offline(struct rq *rq) | |
5264 | { | |
5265 | if (rq->online) { | |
5266 | const struct sched_class *class; | |
5267 | ||
5268 | for_each_class(class) { | |
5269 | if (class->rq_offline) | |
5270 | class->rq_offline(rq); | |
5271 | } | |
5272 | ||
c6c4927b | 5273 | cpumask_clear_cpu(rq->cpu, rq->rd->online); |
1f11eb6a GH |
5274 | rq->online = 0; |
5275 | } | |
5276 | } | |
5277 | ||
1da177e4 LT |
5278 | /* |
5279 | * migration_call - callback that gets triggered when a CPU is added. | |
5280 | * Here we can start up the necessary migration thread for the new CPU. | |
5281 | */ | |
0db0628d | 5282 | static int |
48f24c4d | 5283 | migration_call(struct notifier_block *nfb, unsigned long action, void *hcpu) |
1da177e4 | 5284 | { |
48f24c4d | 5285 | int cpu = (long)hcpu; |
1da177e4 | 5286 | unsigned long flags; |
969c7921 | 5287 | struct rq *rq = cpu_rq(cpu); |
1da177e4 | 5288 | |
48c5ccae | 5289 | switch (action & ~CPU_TASKS_FROZEN) { |
5be9361c | 5290 | |
1da177e4 | 5291 | case CPU_UP_PREPARE: |
a468d389 | 5292 | rq->calc_load_update = calc_load_update; |
1da177e4 | 5293 | break; |
48f24c4d | 5294 | |
1da177e4 | 5295 | case CPU_ONLINE: |
1f94ef59 | 5296 | /* Update our root-domain */ |
05fa785c | 5297 | raw_spin_lock_irqsave(&rq->lock, flags); |
1f94ef59 | 5298 | if (rq->rd) { |
c6c4927b | 5299 | BUG_ON(!cpumask_test_cpu(cpu, rq->rd->span)); |
1f11eb6a GH |
5300 | |
5301 | set_rq_online(rq); | |
1f94ef59 | 5302 | } |
05fa785c | 5303 | raw_spin_unlock_irqrestore(&rq->lock, flags); |
1da177e4 | 5304 | break; |
48f24c4d | 5305 | |
1da177e4 | 5306 | #ifdef CONFIG_HOTPLUG_CPU |
08f503b0 | 5307 | case CPU_DYING: |
317f3941 | 5308 | sched_ttwu_pending(); |
57d885fe | 5309 | /* Update our root-domain */ |
05fa785c | 5310 | raw_spin_lock_irqsave(&rq->lock, flags); |
57d885fe | 5311 | if (rq->rd) { |
c6c4927b | 5312 | BUG_ON(!cpumask_test_cpu(cpu, rq->rd->span)); |
1f11eb6a | 5313 | set_rq_offline(rq); |
57d885fe | 5314 | } |
48c5ccae PZ |
5315 | migrate_tasks(cpu); |
5316 | BUG_ON(rq->nr_running != 1); /* the migration thread */ | |
05fa785c | 5317 | raw_spin_unlock_irqrestore(&rq->lock, flags); |
5d180232 | 5318 | break; |
48c5ccae | 5319 | |
5d180232 | 5320 | case CPU_DEAD: |
f319da0c | 5321 | calc_load_migrate(rq); |
57d885fe | 5322 | break; |
1da177e4 LT |
5323 | #endif |
5324 | } | |
49c022e6 PZ |
5325 | |
5326 | update_max_interval(); | |
5327 | ||
1da177e4 LT |
5328 | return NOTIFY_OK; |
5329 | } | |
5330 | ||
f38b0820 PM |
5331 | /* |
5332 | * Register at high priority so that task migration (migrate_all_tasks) | |
5333 | * happens before everything else. This has to be lower priority than | |
cdd6c482 | 5334 | * the notifier in the perf_event subsystem, though. |
1da177e4 | 5335 | */ |
0db0628d | 5336 | static struct notifier_block migration_notifier = { |
1da177e4 | 5337 | .notifier_call = migration_call, |
50a323b7 | 5338 | .priority = CPU_PRI_MIGRATION, |
1da177e4 LT |
5339 | }; |
5340 | ||
a803f026 CM |
5341 | static void __cpuinit set_cpu_rq_start_time(void) |
5342 | { | |
5343 | int cpu = smp_processor_id(); | |
5344 | struct rq *rq = cpu_rq(cpu); | |
5345 | rq->age_stamp = sched_clock_cpu(cpu); | |
5346 | } | |
5347 | ||
0db0628d | 5348 | static int sched_cpu_active(struct notifier_block *nfb, |
3a101d05 TH |
5349 | unsigned long action, void *hcpu) |
5350 | { | |
5351 | switch (action & ~CPU_TASKS_FROZEN) { | |
a803f026 CM |
5352 | case CPU_STARTING: |
5353 | set_cpu_rq_start_time(); | |
5354 | return NOTIFY_OK; | |
3a101d05 TH |
5355 | case CPU_DOWN_FAILED: |
5356 | set_cpu_active((long)hcpu, true); | |
5357 | return NOTIFY_OK; | |
5358 | default: | |
5359 | return NOTIFY_DONE; | |
5360 | } | |
5361 | } | |
5362 | ||
0db0628d | 5363 | static int sched_cpu_inactive(struct notifier_block *nfb, |
3a101d05 TH |
5364 | unsigned long action, void *hcpu) |
5365 | { | |
de212f18 PZ |
5366 | unsigned long flags; |
5367 | long cpu = (long)hcpu; | |
f10e00f4 | 5368 | struct dl_bw *dl_b; |
de212f18 | 5369 | |
3a101d05 TH |
5370 | switch (action & ~CPU_TASKS_FROZEN) { |
5371 | case CPU_DOWN_PREPARE: | |
de212f18 PZ |
5372 | set_cpu_active(cpu, false); |
5373 | ||
5374 | /* explicitly allow suspend */ | |
5375 | if (!(action & CPU_TASKS_FROZEN)) { | |
de212f18 PZ |
5376 | bool overflow; |
5377 | int cpus; | |
5378 | ||
f10e00f4 KT |
5379 | rcu_read_lock_sched(); |
5380 | dl_b = dl_bw_of(cpu); | |
5381 | ||
de212f18 PZ |
5382 | raw_spin_lock_irqsave(&dl_b->lock, flags); |
5383 | cpus = dl_bw_cpus(cpu); | |
5384 | overflow = __dl_overflow(dl_b, cpus, 0, 0); | |
5385 | raw_spin_unlock_irqrestore(&dl_b->lock, flags); | |
5386 | ||
f10e00f4 KT |
5387 | rcu_read_unlock_sched(); |
5388 | ||
de212f18 PZ |
5389 | if (overflow) |
5390 | return notifier_from_errno(-EBUSY); | |
5391 | } | |
3a101d05 | 5392 | return NOTIFY_OK; |
3a101d05 | 5393 | } |
de212f18 PZ |
5394 | |
5395 | return NOTIFY_DONE; | |
3a101d05 TH |
5396 | } |
5397 | ||
7babe8db | 5398 | static int __init migration_init(void) |
1da177e4 LT |
5399 | { |
5400 | void *cpu = (void *)(long)smp_processor_id(); | |
07dccf33 | 5401 | int err; |
48f24c4d | 5402 | |
3a101d05 | 5403 | /* Initialize migration for the boot CPU */ |
07dccf33 AM |
5404 | err = migration_call(&migration_notifier, CPU_UP_PREPARE, cpu); |
5405 | BUG_ON(err == NOTIFY_BAD); | |
1da177e4 LT |
5406 | migration_call(&migration_notifier, CPU_ONLINE, cpu); |
5407 | register_cpu_notifier(&migration_notifier); | |
7babe8db | 5408 | |
3a101d05 TH |
5409 | /* Register cpu active notifiers */ |
5410 | cpu_notifier(sched_cpu_active, CPU_PRI_SCHED_ACTIVE); | |
5411 | cpu_notifier(sched_cpu_inactive, CPU_PRI_SCHED_INACTIVE); | |
5412 | ||
a004cd42 | 5413 | return 0; |
1da177e4 | 5414 | } |
7babe8db | 5415 | early_initcall(migration_init); |
1da177e4 LT |
5416 | #endif |
5417 | ||
5418 | #ifdef CONFIG_SMP | |
476f3534 | 5419 | |
4cb98839 PZ |
5420 | static cpumask_var_t sched_domains_tmpmask; /* sched_domains_mutex */ |
5421 | ||
3e9830dc | 5422 | #ifdef CONFIG_SCHED_DEBUG |
4dcf6aff | 5423 | |
d039ac60 | 5424 | static __read_mostly int sched_debug_enabled; |
f6630114 | 5425 | |
d039ac60 | 5426 | static int __init sched_debug_setup(char *str) |
f6630114 | 5427 | { |
d039ac60 | 5428 | sched_debug_enabled = 1; |
f6630114 MT |
5429 | |
5430 | return 0; | |
5431 | } | |
d039ac60 PZ |
5432 | early_param("sched_debug", sched_debug_setup); |
5433 | ||
5434 | static inline bool sched_debug(void) | |
5435 | { | |
5436 | return sched_debug_enabled; | |
5437 | } | |
f6630114 | 5438 | |
7c16ec58 | 5439 | static int sched_domain_debug_one(struct sched_domain *sd, int cpu, int level, |
96f874e2 | 5440 | struct cpumask *groupmask) |
1da177e4 | 5441 | { |
4dcf6aff | 5442 | struct sched_group *group = sd->groups; |
434d53b0 | 5443 | char str[256]; |
1da177e4 | 5444 | |
968ea6d8 | 5445 | cpulist_scnprintf(str, sizeof(str), sched_domain_span(sd)); |
96f874e2 | 5446 | cpumask_clear(groupmask); |
4dcf6aff IM |
5447 | |
5448 | printk(KERN_DEBUG "%*s domain %d: ", level, "", level); | |
5449 | ||
5450 | if (!(sd->flags & SD_LOAD_BALANCE)) { | |
3df0fc5b | 5451 | printk("does not load-balance\n"); |
4dcf6aff | 5452 | if (sd->parent) |
3df0fc5b PZ |
5453 | printk(KERN_ERR "ERROR: !SD_LOAD_BALANCE domain" |
5454 | " has parent"); | |
4dcf6aff | 5455 | return -1; |
41c7ce9a NP |
5456 | } |
5457 | ||
3df0fc5b | 5458 | printk(KERN_CONT "span %s level %s\n", str, sd->name); |
4dcf6aff | 5459 | |
758b2cdc | 5460 | if (!cpumask_test_cpu(cpu, sched_domain_span(sd))) { |
3df0fc5b PZ |
5461 | printk(KERN_ERR "ERROR: domain->span does not contain " |
5462 | "CPU%d\n", cpu); | |
4dcf6aff | 5463 | } |
758b2cdc | 5464 | if (!cpumask_test_cpu(cpu, sched_group_cpus(group))) { |
3df0fc5b PZ |
5465 | printk(KERN_ERR "ERROR: domain->groups does not contain" |
5466 | " CPU%d\n", cpu); | |
4dcf6aff | 5467 | } |
1da177e4 | 5468 | |
4dcf6aff | 5469 | printk(KERN_DEBUG "%*s groups:", level + 1, ""); |
1da177e4 | 5470 | do { |
4dcf6aff | 5471 | if (!group) { |
3df0fc5b PZ |
5472 | printk("\n"); |
5473 | printk(KERN_ERR "ERROR: group is NULL\n"); | |
1da177e4 LT |
5474 | break; |
5475 | } | |
5476 | ||
c3decf0d | 5477 | /* |
63b2ca30 NP |
5478 | * Even though we initialize ->capacity to something semi-sane, |
5479 | * we leave capacity_orig unset. This allows us to detect if | |
c3decf0d PZ |
5480 | * domain iteration is still funny without causing /0 traps. |
5481 | */ | |
63b2ca30 | 5482 | if (!group->sgc->capacity_orig) { |
3df0fc5b | 5483 | printk(KERN_CONT "\n"); |
63b2ca30 | 5484 | printk(KERN_ERR "ERROR: domain->cpu_capacity not set\n"); |
4dcf6aff IM |
5485 | break; |
5486 | } | |
1da177e4 | 5487 | |
758b2cdc | 5488 | if (!cpumask_weight(sched_group_cpus(group))) { |
3df0fc5b PZ |
5489 | printk(KERN_CONT "\n"); |
5490 | printk(KERN_ERR "ERROR: empty group\n"); | |
4dcf6aff IM |
5491 | break; |
5492 | } | |
1da177e4 | 5493 | |
cb83b629 PZ |
5494 | if (!(sd->flags & SD_OVERLAP) && |
5495 | cpumask_intersects(groupmask, sched_group_cpus(group))) { | |
3df0fc5b PZ |
5496 | printk(KERN_CONT "\n"); |
5497 | printk(KERN_ERR "ERROR: repeated CPUs\n"); | |
4dcf6aff IM |
5498 | break; |
5499 | } | |
1da177e4 | 5500 | |
758b2cdc | 5501 | cpumask_or(groupmask, groupmask, sched_group_cpus(group)); |
1da177e4 | 5502 | |
968ea6d8 | 5503 | cpulist_scnprintf(str, sizeof(str), sched_group_cpus(group)); |
381512cf | 5504 | |
3df0fc5b | 5505 | printk(KERN_CONT " %s", str); |
ca8ce3d0 | 5506 | if (group->sgc->capacity != SCHED_CAPACITY_SCALE) { |
63b2ca30 NP |
5507 | printk(KERN_CONT " (cpu_capacity = %d)", |
5508 | group->sgc->capacity); | |
381512cf | 5509 | } |
1da177e4 | 5510 | |
4dcf6aff IM |
5511 | group = group->next; |
5512 | } while (group != sd->groups); | |
3df0fc5b | 5513 | printk(KERN_CONT "\n"); |
1da177e4 | 5514 | |
758b2cdc | 5515 | if (!cpumask_equal(sched_domain_span(sd), groupmask)) |
3df0fc5b | 5516 | printk(KERN_ERR "ERROR: groups don't span domain->span\n"); |
1da177e4 | 5517 | |
758b2cdc RR |
5518 | if (sd->parent && |
5519 | !cpumask_subset(groupmask, sched_domain_span(sd->parent))) | |
3df0fc5b PZ |
5520 | printk(KERN_ERR "ERROR: parent span is not a superset " |
5521 | "of domain->span\n"); | |
4dcf6aff IM |
5522 | return 0; |
5523 | } | |
1da177e4 | 5524 | |
4dcf6aff IM |
5525 | static void sched_domain_debug(struct sched_domain *sd, int cpu) |
5526 | { | |
5527 | int level = 0; | |
1da177e4 | 5528 | |
d039ac60 | 5529 | if (!sched_debug_enabled) |
f6630114 MT |
5530 | return; |
5531 | ||
4dcf6aff IM |
5532 | if (!sd) { |
5533 | printk(KERN_DEBUG "CPU%d attaching NULL sched-domain.\n", cpu); | |
5534 | return; | |
5535 | } | |
1da177e4 | 5536 | |
4dcf6aff IM |
5537 | printk(KERN_DEBUG "CPU%d attaching sched-domain:\n", cpu); |
5538 | ||
5539 | for (;;) { | |
4cb98839 | 5540 | if (sched_domain_debug_one(sd, cpu, level, sched_domains_tmpmask)) |
4dcf6aff | 5541 | break; |
1da177e4 LT |
5542 | level++; |
5543 | sd = sd->parent; | |
33859f7f | 5544 | if (!sd) |
4dcf6aff IM |
5545 | break; |
5546 | } | |
1da177e4 | 5547 | } |
6d6bc0ad | 5548 | #else /* !CONFIG_SCHED_DEBUG */ |
48f24c4d | 5549 | # define sched_domain_debug(sd, cpu) do { } while (0) |
d039ac60 PZ |
5550 | static inline bool sched_debug(void) |
5551 | { | |
5552 | return false; | |
5553 | } | |
6d6bc0ad | 5554 | #endif /* CONFIG_SCHED_DEBUG */ |
1da177e4 | 5555 | |
1a20ff27 | 5556 | static int sd_degenerate(struct sched_domain *sd) |
245af2c7 | 5557 | { |
758b2cdc | 5558 | if (cpumask_weight(sched_domain_span(sd)) == 1) |
245af2c7 SS |
5559 | return 1; |
5560 | ||
5561 | /* Following flags need at least 2 groups */ | |
5562 | if (sd->flags & (SD_LOAD_BALANCE | | |
5563 | SD_BALANCE_NEWIDLE | | |
5564 | SD_BALANCE_FORK | | |
89c4710e | 5565 | SD_BALANCE_EXEC | |
5d4dfddd | 5566 | SD_SHARE_CPUCAPACITY | |
d77b3ed5 VG |
5567 | SD_SHARE_PKG_RESOURCES | |
5568 | SD_SHARE_POWERDOMAIN)) { | |
245af2c7 SS |
5569 | if (sd->groups != sd->groups->next) |
5570 | return 0; | |
5571 | } | |
5572 | ||
5573 | /* Following flags don't use groups */ | |
c88d5910 | 5574 | if (sd->flags & (SD_WAKE_AFFINE)) |
245af2c7 SS |
5575 | return 0; |
5576 | ||
5577 | return 1; | |
5578 | } | |
5579 | ||
48f24c4d IM |
5580 | static int |
5581 | sd_parent_degenerate(struct sched_domain *sd, struct sched_domain *parent) | |
245af2c7 SS |
5582 | { |
5583 | unsigned long cflags = sd->flags, pflags = parent->flags; | |
5584 | ||
5585 | if (sd_degenerate(parent)) | |
5586 | return 1; | |
5587 | ||
758b2cdc | 5588 | if (!cpumask_equal(sched_domain_span(sd), sched_domain_span(parent))) |
245af2c7 SS |
5589 | return 0; |
5590 | ||
245af2c7 SS |
5591 | /* Flags needing groups don't count if only 1 group in parent */ |
5592 | if (parent->groups == parent->groups->next) { | |
5593 | pflags &= ~(SD_LOAD_BALANCE | | |
5594 | SD_BALANCE_NEWIDLE | | |
5595 | SD_BALANCE_FORK | | |
89c4710e | 5596 | SD_BALANCE_EXEC | |
5d4dfddd | 5597 | SD_SHARE_CPUCAPACITY | |
10866e62 | 5598 | SD_SHARE_PKG_RESOURCES | |
d77b3ed5 VG |
5599 | SD_PREFER_SIBLING | |
5600 | SD_SHARE_POWERDOMAIN); | |
5436499e KC |
5601 | if (nr_node_ids == 1) |
5602 | pflags &= ~SD_SERIALIZE; | |
245af2c7 SS |
5603 | } |
5604 | if (~cflags & pflags) | |
5605 | return 0; | |
5606 | ||
5607 | return 1; | |
5608 | } | |
5609 | ||
dce840a0 | 5610 | static void free_rootdomain(struct rcu_head *rcu) |
c6c4927b | 5611 | { |
dce840a0 | 5612 | struct root_domain *rd = container_of(rcu, struct root_domain, rcu); |
047106ad | 5613 | |
68e74568 | 5614 | cpupri_cleanup(&rd->cpupri); |
6bfd6d72 | 5615 | cpudl_cleanup(&rd->cpudl); |
1baca4ce | 5616 | free_cpumask_var(rd->dlo_mask); |
c6c4927b RR |
5617 | free_cpumask_var(rd->rto_mask); |
5618 | free_cpumask_var(rd->online); | |
5619 | free_cpumask_var(rd->span); | |
5620 | kfree(rd); | |
5621 | } | |
5622 | ||
57d885fe GH |
5623 | static void rq_attach_root(struct rq *rq, struct root_domain *rd) |
5624 | { | |
a0490fa3 | 5625 | struct root_domain *old_rd = NULL; |
57d885fe | 5626 | unsigned long flags; |
57d885fe | 5627 | |
05fa785c | 5628 | raw_spin_lock_irqsave(&rq->lock, flags); |
57d885fe GH |
5629 | |
5630 | if (rq->rd) { | |
a0490fa3 | 5631 | old_rd = rq->rd; |
57d885fe | 5632 | |
c6c4927b | 5633 | if (cpumask_test_cpu(rq->cpu, old_rd->online)) |
1f11eb6a | 5634 | set_rq_offline(rq); |
57d885fe | 5635 | |
c6c4927b | 5636 | cpumask_clear_cpu(rq->cpu, old_rd->span); |
dc938520 | 5637 | |
a0490fa3 | 5638 | /* |
0515973f | 5639 | * If we dont want to free the old_rd yet then |
a0490fa3 IM |
5640 | * set old_rd to NULL to skip the freeing later |
5641 | * in this function: | |
5642 | */ | |
5643 | if (!atomic_dec_and_test(&old_rd->refcount)) | |
5644 | old_rd = NULL; | |
57d885fe GH |
5645 | } |
5646 | ||
5647 | atomic_inc(&rd->refcount); | |
5648 | rq->rd = rd; | |
5649 | ||
c6c4927b | 5650 | cpumask_set_cpu(rq->cpu, rd->span); |
00aec93d | 5651 | if (cpumask_test_cpu(rq->cpu, cpu_active_mask)) |
1f11eb6a | 5652 | set_rq_online(rq); |
57d885fe | 5653 | |
05fa785c | 5654 | raw_spin_unlock_irqrestore(&rq->lock, flags); |
a0490fa3 IM |
5655 | |
5656 | if (old_rd) | |
dce840a0 | 5657 | call_rcu_sched(&old_rd->rcu, free_rootdomain); |
57d885fe GH |
5658 | } |
5659 | ||
68c38fc3 | 5660 | static int init_rootdomain(struct root_domain *rd) |
57d885fe GH |
5661 | { |
5662 | memset(rd, 0, sizeof(*rd)); | |
5663 | ||
68c38fc3 | 5664 | if (!alloc_cpumask_var(&rd->span, GFP_KERNEL)) |
0c910d28 | 5665 | goto out; |
68c38fc3 | 5666 | if (!alloc_cpumask_var(&rd->online, GFP_KERNEL)) |
c6c4927b | 5667 | goto free_span; |
1baca4ce | 5668 | if (!alloc_cpumask_var(&rd->dlo_mask, GFP_KERNEL)) |
c6c4927b | 5669 | goto free_online; |
1baca4ce JL |
5670 | if (!alloc_cpumask_var(&rd->rto_mask, GFP_KERNEL)) |
5671 | goto free_dlo_mask; | |
6e0534f2 | 5672 | |
332ac17e | 5673 | init_dl_bw(&rd->dl_bw); |
6bfd6d72 JL |
5674 | if (cpudl_init(&rd->cpudl) != 0) |
5675 | goto free_dlo_mask; | |
332ac17e | 5676 | |
68c38fc3 | 5677 | if (cpupri_init(&rd->cpupri) != 0) |
68e74568 | 5678 | goto free_rto_mask; |
c6c4927b | 5679 | return 0; |
6e0534f2 | 5680 | |
68e74568 RR |
5681 | free_rto_mask: |
5682 | free_cpumask_var(rd->rto_mask); | |
1baca4ce JL |
5683 | free_dlo_mask: |
5684 | free_cpumask_var(rd->dlo_mask); | |
c6c4927b RR |
5685 | free_online: |
5686 | free_cpumask_var(rd->online); | |
5687 | free_span: | |
5688 | free_cpumask_var(rd->span); | |
0c910d28 | 5689 | out: |
c6c4927b | 5690 | return -ENOMEM; |
57d885fe GH |
5691 | } |
5692 | ||
029632fb PZ |
5693 | /* |
5694 | * By default the system creates a single root-domain with all cpus as | |
5695 | * members (mimicking the global state we have today). | |
5696 | */ | |
5697 | struct root_domain def_root_domain; | |
5698 | ||
57d885fe GH |
5699 | static void init_defrootdomain(void) |
5700 | { | |
68c38fc3 | 5701 | init_rootdomain(&def_root_domain); |
c6c4927b | 5702 | |
57d885fe GH |
5703 | atomic_set(&def_root_domain.refcount, 1); |
5704 | } | |
5705 | ||
dc938520 | 5706 | static struct root_domain *alloc_rootdomain(void) |
57d885fe GH |
5707 | { |
5708 | struct root_domain *rd; | |
5709 | ||
5710 | rd = kmalloc(sizeof(*rd), GFP_KERNEL); | |
5711 | if (!rd) | |
5712 | return NULL; | |
5713 | ||
68c38fc3 | 5714 | if (init_rootdomain(rd) != 0) { |
c6c4927b RR |
5715 | kfree(rd); |
5716 | return NULL; | |
5717 | } | |
57d885fe GH |
5718 | |
5719 | return rd; | |
5720 | } | |
5721 | ||
63b2ca30 | 5722 | static void free_sched_groups(struct sched_group *sg, int free_sgc) |
e3589f6c PZ |
5723 | { |
5724 | struct sched_group *tmp, *first; | |
5725 | ||
5726 | if (!sg) | |
5727 | return; | |
5728 | ||
5729 | first = sg; | |
5730 | do { | |
5731 | tmp = sg->next; | |
5732 | ||
63b2ca30 NP |
5733 | if (free_sgc && atomic_dec_and_test(&sg->sgc->ref)) |
5734 | kfree(sg->sgc); | |
e3589f6c PZ |
5735 | |
5736 | kfree(sg); | |
5737 | sg = tmp; | |
5738 | } while (sg != first); | |
5739 | } | |
5740 | ||
dce840a0 PZ |
5741 | static void free_sched_domain(struct rcu_head *rcu) |
5742 | { | |
5743 | struct sched_domain *sd = container_of(rcu, struct sched_domain, rcu); | |
e3589f6c PZ |
5744 | |
5745 | /* | |
5746 | * If its an overlapping domain it has private groups, iterate and | |
5747 | * nuke them all. | |
5748 | */ | |
5749 | if (sd->flags & SD_OVERLAP) { | |
5750 | free_sched_groups(sd->groups, 1); | |
5751 | } else if (atomic_dec_and_test(&sd->groups->ref)) { | |
63b2ca30 | 5752 | kfree(sd->groups->sgc); |
dce840a0 | 5753 | kfree(sd->groups); |
9c3f75cb | 5754 | } |
dce840a0 PZ |
5755 | kfree(sd); |
5756 | } | |
5757 | ||
5758 | static void destroy_sched_domain(struct sched_domain *sd, int cpu) | |
5759 | { | |
5760 | call_rcu(&sd->rcu, free_sched_domain); | |
5761 | } | |
5762 | ||
5763 | static void destroy_sched_domains(struct sched_domain *sd, int cpu) | |
5764 | { | |
5765 | for (; sd; sd = sd->parent) | |
5766 | destroy_sched_domain(sd, cpu); | |
5767 | } | |
5768 | ||
518cd623 PZ |
5769 | /* |
5770 | * Keep a special pointer to the highest sched_domain that has | |
5771 | * SD_SHARE_PKG_RESOURCE set (Last Level Cache Domain) for this | |
5772 | * allows us to avoid some pointer chasing select_idle_sibling(). | |
5773 | * | |
5774 | * Also keep a unique ID per domain (we use the first cpu number in | |
5775 | * the cpumask of the domain), this allows us to quickly tell if | |
39be3501 | 5776 | * two cpus are in the same cache domain, see cpus_share_cache(). |
518cd623 PZ |
5777 | */ |
5778 | DEFINE_PER_CPU(struct sched_domain *, sd_llc); | |
7d9ffa89 | 5779 | DEFINE_PER_CPU(int, sd_llc_size); |
518cd623 | 5780 | DEFINE_PER_CPU(int, sd_llc_id); |
fb13c7ee | 5781 | DEFINE_PER_CPU(struct sched_domain *, sd_numa); |
37dc6b50 PM |
5782 | DEFINE_PER_CPU(struct sched_domain *, sd_busy); |
5783 | DEFINE_PER_CPU(struct sched_domain *, sd_asym); | |
518cd623 PZ |
5784 | |
5785 | static void update_top_cache_domain(int cpu) | |
5786 | { | |
5787 | struct sched_domain *sd; | |
5d4cf996 | 5788 | struct sched_domain *busy_sd = NULL; |
518cd623 | 5789 | int id = cpu; |
7d9ffa89 | 5790 | int size = 1; |
518cd623 PZ |
5791 | |
5792 | sd = highest_flag_domain(cpu, SD_SHARE_PKG_RESOURCES); | |
7d9ffa89 | 5793 | if (sd) { |
518cd623 | 5794 | id = cpumask_first(sched_domain_span(sd)); |
7d9ffa89 | 5795 | size = cpumask_weight(sched_domain_span(sd)); |
5d4cf996 | 5796 | busy_sd = sd->parent; /* sd_busy */ |
7d9ffa89 | 5797 | } |
5d4cf996 | 5798 | rcu_assign_pointer(per_cpu(sd_busy, cpu), busy_sd); |
518cd623 PZ |
5799 | |
5800 | rcu_assign_pointer(per_cpu(sd_llc, cpu), sd); | |
7d9ffa89 | 5801 | per_cpu(sd_llc_size, cpu) = size; |
518cd623 | 5802 | per_cpu(sd_llc_id, cpu) = id; |
fb13c7ee MG |
5803 | |
5804 | sd = lowest_flag_domain(cpu, SD_NUMA); | |
5805 | rcu_assign_pointer(per_cpu(sd_numa, cpu), sd); | |
37dc6b50 PM |
5806 | |
5807 | sd = highest_flag_domain(cpu, SD_ASYM_PACKING); | |
5808 | rcu_assign_pointer(per_cpu(sd_asym, cpu), sd); | |
518cd623 PZ |
5809 | } |
5810 | ||
1da177e4 | 5811 | /* |
0eab9146 | 5812 | * Attach the domain 'sd' to 'cpu' as its base domain. Callers must |
1da177e4 LT |
5813 | * hold the hotplug lock. |
5814 | */ | |
0eab9146 IM |
5815 | static void |
5816 | cpu_attach_domain(struct sched_domain *sd, struct root_domain *rd, int cpu) | |
1da177e4 | 5817 | { |
70b97a7f | 5818 | struct rq *rq = cpu_rq(cpu); |
245af2c7 SS |
5819 | struct sched_domain *tmp; |
5820 | ||
5821 | /* Remove the sched domains which do not contribute to scheduling. */ | |
f29c9b1c | 5822 | for (tmp = sd; tmp; ) { |
245af2c7 SS |
5823 | struct sched_domain *parent = tmp->parent; |
5824 | if (!parent) | |
5825 | break; | |
f29c9b1c | 5826 | |
1a848870 | 5827 | if (sd_parent_degenerate(tmp, parent)) { |
245af2c7 | 5828 | tmp->parent = parent->parent; |
1a848870 SS |
5829 | if (parent->parent) |
5830 | parent->parent->child = tmp; | |
10866e62 PZ |
5831 | /* |
5832 | * Transfer SD_PREFER_SIBLING down in case of a | |
5833 | * degenerate parent; the spans match for this | |
5834 | * so the property transfers. | |
5835 | */ | |
5836 | if (parent->flags & SD_PREFER_SIBLING) | |
5837 | tmp->flags |= SD_PREFER_SIBLING; | |
dce840a0 | 5838 | destroy_sched_domain(parent, cpu); |
f29c9b1c LZ |
5839 | } else |
5840 | tmp = tmp->parent; | |
245af2c7 SS |
5841 | } |
5842 | ||
1a848870 | 5843 | if (sd && sd_degenerate(sd)) { |
dce840a0 | 5844 | tmp = sd; |
245af2c7 | 5845 | sd = sd->parent; |
dce840a0 | 5846 | destroy_sched_domain(tmp, cpu); |
1a848870 SS |
5847 | if (sd) |
5848 | sd->child = NULL; | |
5849 | } | |
1da177e4 | 5850 | |
4cb98839 | 5851 | sched_domain_debug(sd, cpu); |
1da177e4 | 5852 | |
57d885fe | 5853 | rq_attach_root(rq, rd); |
dce840a0 | 5854 | tmp = rq->sd; |
674311d5 | 5855 | rcu_assign_pointer(rq->sd, sd); |
dce840a0 | 5856 | destroy_sched_domains(tmp, cpu); |
518cd623 PZ |
5857 | |
5858 | update_top_cache_domain(cpu); | |
1da177e4 LT |
5859 | } |
5860 | ||
5861 | /* cpus with isolated domains */ | |
dcc30a35 | 5862 | static cpumask_var_t cpu_isolated_map; |
1da177e4 LT |
5863 | |
5864 | /* Setup the mask of cpus configured for isolated domains */ | |
5865 | static int __init isolated_cpu_setup(char *str) | |
5866 | { | |
bdddd296 | 5867 | alloc_bootmem_cpumask_var(&cpu_isolated_map); |
968ea6d8 | 5868 | cpulist_parse(str, cpu_isolated_map); |
1da177e4 LT |
5869 | return 1; |
5870 | } | |
5871 | ||
8927f494 | 5872 | __setup("isolcpus=", isolated_cpu_setup); |
1da177e4 | 5873 | |
49a02c51 | 5874 | struct s_data { |
21d42ccf | 5875 | struct sched_domain ** __percpu sd; |
49a02c51 AH |
5876 | struct root_domain *rd; |
5877 | }; | |
5878 | ||
2109b99e | 5879 | enum s_alloc { |
2109b99e | 5880 | sa_rootdomain, |
21d42ccf | 5881 | sa_sd, |
dce840a0 | 5882 | sa_sd_storage, |
2109b99e AH |
5883 | sa_none, |
5884 | }; | |
5885 | ||
c1174876 PZ |
5886 | /* |
5887 | * Build an iteration mask that can exclude certain CPUs from the upwards | |
5888 | * domain traversal. | |
5889 | * | |
5890 | * Asymmetric node setups can result in situations where the domain tree is of | |
5891 | * unequal depth, make sure to skip domains that already cover the entire | |
5892 | * range. | |
5893 | * | |
5894 | * In that case build_sched_domains() will have terminated the iteration early | |
5895 | * and our sibling sd spans will be empty. Domains should always include the | |
5896 | * cpu they're built on, so check that. | |
5897 | * | |
5898 | */ | |
5899 | static void build_group_mask(struct sched_domain *sd, struct sched_group *sg) | |
5900 | { | |
5901 | const struct cpumask *span = sched_domain_span(sd); | |
5902 | struct sd_data *sdd = sd->private; | |
5903 | struct sched_domain *sibling; | |
5904 | int i; | |
5905 | ||
5906 | for_each_cpu(i, span) { | |
5907 | sibling = *per_cpu_ptr(sdd->sd, i); | |
5908 | if (!cpumask_test_cpu(i, sched_domain_span(sibling))) | |
5909 | continue; | |
5910 | ||
5911 | cpumask_set_cpu(i, sched_group_mask(sg)); | |
5912 | } | |
5913 | } | |
5914 | ||
5915 | /* | |
5916 | * Return the canonical balance cpu for this group, this is the first cpu | |
5917 | * of this group that's also in the iteration mask. | |
5918 | */ | |
5919 | int group_balance_cpu(struct sched_group *sg) | |
5920 | { | |
5921 | return cpumask_first_and(sched_group_cpus(sg), sched_group_mask(sg)); | |
5922 | } | |
5923 | ||
e3589f6c PZ |
5924 | static int |
5925 | build_overlap_sched_groups(struct sched_domain *sd, int cpu) | |
5926 | { | |
5927 | struct sched_group *first = NULL, *last = NULL, *groups = NULL, *sg; | |
5928 | const struct cpumask *span = sched_domain_span(sd); | |
5929 | struct cpumask *covered = sched_domains_tmpmask; | |
5930 | struct sd_data *sdd = sd->private; | |
aaecac4a | 5931 | struct sched_domain *sibling; |
e3589f6c PZ |
5932 | int i; |
5933 | ||
5934 | cpumask_clear(covered); | |
5935 | ||
5936 | for_each_cpu(i, span) { | |
5937 | struct cpumask *sg_span; | |
5938 | ||
5939 | if (cpumask_test_cpu(i, covered)) | |
5940 | continue; | |
5941 | ||
aaecac4a | 5942 | sibling = *per_cpu_ptr(sdd->sd, i); |
c1174876 PZ |
5943 | |
5944 | /* See the comment near build_group_mask(). */ | |
aaecac4a | 5945 | if (!cpumask_test_cpu(i, sched_domain_span(sibling))) |
c1174876 PZ |
5946 | continue; |
5947 | ||
e3589f6c | 5948 | sg = kzalloc_node(sizeof(struct sched_group) + cpumask_size(), |
4d78a223 | 5949 | GFP_KERNEL, cpu_to_node(cpu)); |
e3589f6c PZ |
5950 | |
5951 | if (!sg) | |
5952 | goto fail; | |
5953 | ||
5954 | sg_span = sched_group_cpus(sg); | |
aaecac4a ZZ |
5955 | if (sibling->child) |
5956 | cpumask_copy(sg_span, sched_domain_span(sibling->child)); | |
5957 | else | |
e3589f6c PZ |
5958 | cpumask_set_cpu(i, sg_span); |
5959 | ||
5960 | cpumask_or(covered, covered, sg_span); | |
5961 | ||
63b2ca30 NP |
5962 | sg->sgc = *per_cpu_ptr(sdd->sgc, i); |
5963 | if (atomic_inc_return(&sg->sgc->ref) == 1) | |
c1174876 PZ |
5964 | build_group_mask(sd, sg); |
5965 | ||
c3decf0d | 5966 | /* |
63b2ca30 | 5967 | * Initialize sgc->capacity such that even if we mess up the |
c3decf0d PZ |
5968 | * domains and no possible iteration will get us here, we won't |
5969 | * die on a /0 trap. | |
5970 | */ | |
ca8ce3d0 | 5971 | sg->sgc->capacity = SCHED_CAPACITY_SCALE * cpumask_weight(sg_span); |
63b2ca30 | 5972 | sg->sgc->capacity_orig = sg->sgc->capacity; |
e3589f6c | 5973 | |
c1174876 PZ |
5974 | /* |
5975 | * Make sure the first group of this domain contains the | |
5976 | * canonical balance cpu. Otherwise the sched_domain iteration | |
5977 | * breaks. See update_sg_lb_stats(). | |
5978 | */ | |
74a5ce20 | 5979 | if ((!groups && cpumask_test_cpu(cpu, sg_span)) || |
c1174876 | 5980 | group_balance_cpu(sg) == cpu) |
e3589f6c PZ |
5981 | groups = sg; |
5982 | ||
5983 | if (!first) | |
5984 | first = sg; | |
5985 | if (last) | |
5986 | last->next = sg; | |
5987 | last = sg; | |
5988 | last->next = first; | |
5989 | } | |
5990 | sd->groups = groups; | |
5991 | ||
5992 | return 0; | |
5993 | ||
5994 | fail: | |
5995 | free_sched_groups(first, 0); | |
5996 | ||
5997 | return -ENOMEM; | |
5998 | } | |
5999 | ||
dce840a0 | 6000 | static int get_group(int cpu, struct sd_data *sdd, struct sched_group **sg) |
1da177e4 | 6001 | { |
dce840a0 PZ |
6002 | struct sched_domain *sd = *per_cpu_ptr(sdd->sd, cpu); |
6003 | struct sched_domain *child = sd->child; | |
1da177e4 | 6004 | |
dce840a0 PZ |
6005 | if (child) |
6006 | cpu = cpumask_first(sched_domain_span(child)); | |
1e9f28fa | 6007 | |
9c3f75cb | 6008 | if (sg) { |
dce840a0 | 6009 | *sg = *per_cpu_ptr(sdd->sg, cpu); |
63b2ca30 NP |
6010 | (*sg)->sgc = *per_cpu_ptr(sdd->sgc, cpu); |
6011 | atomic_set(&(*sg)->sgc->ref, 1); /* for claim_allocations */ | |
9c3f75cb | 6012 | } |
dce840a0 PZ |
6013 | |
6014 | return cpu; | |
1e9f28fa | 6015 | } |
1e9f28fa | 6016 | |
01a08546 | 6017 | /* |
dce840a0 PZ |
6018 | * build_sched_groups will build a circular linked list of the groups |
6019 | * covered by the given span, and will set each group's ->cpumask correctly, | |
ced549fa | 6020 | * and ->cpu_capacity to 0. |
e3589f6c PZ |
6021 | * |
6022 | * Assumes the sched_domain tree is fully constructed | |
01a08546 | 6023 | */ |
e3589f6c PZ |
6024 | static int |
6025 | build_sched_groups(struct sched_domain *sd, int cpu) | |
1da177e4 | 6026 | { |
dce840a0 PZ |
6027 | struct sched_group *first = NULL, *last = NULL; |
6028 | struct sd_data *sdd = sd->private; | |
6029 | const struct cpumask *span = sched_domain_span(sd); | |
f96225fd | 6030 | struct cpumask *covered; |
dce840a0 | 6031 | int i; |
9c1cfda2 | 6032 | |
e3589f6c PZ |
6033 | get_group(cpu, sdd, &sd->groups); |
6034 | atomic_inc(&sd->groups->ref); | |
6035 | ||
0936629f | 6036 | if (cpu != cpumask_first(span)) |
e3589f6c PZ |
6037 | return 0; |
6038 | ||
f96225fd PZ |
6039 | lockdep_assert_held(&sched_domains_mutex); |
6040 | covered = sched_domains_tmpmask; | |
6041 | ||
dce840a0 | 6042 | cpumask_clear(covered); |
6711cab4 | 6043 | |
dce840a0 PZ |
6044 | for_each_cpu(i, span) { |
6045 | struct sched_group *sg; | |
cd08e923 | 6046 | int group, j; |
6711cab4 | 6047 | |
dce840a0 PZ |
6048 | if (cpumask_test_cpu(i, covered)) |
6049 | continue; | |
6711cab4 | 6050 | |
cd08e923 | 6051 | group = get_group(i, sdd, &sg); |
c1174876 | 6052 | cpumask_setall(sched_group_mask(sg)); |
0601a88d | 6053 | |
dce840a0 PZ |
6054 | for_each_cpu(j, span) { |
6055 | if (get_group(j, sdd, NULL) != group) | |
6056 | continue; | |
0601a88d | 6057 | |
dce840a0 PZ |
6058 | cpumask_set_cpu(j, covered); |
6059 | cpumask_set_cpu(j, sched_group_cpus(sg)); | |
6060 | } | |
0601a88d | 6061 | |
dce840a0 PZ |
6062 | if (!first) |
6063 | first = sg; | |
6064 | if (last) | |
6065 | last->next = sg; | |
6066 | last = sg; | |
6067 | } | |
6068 | last->next = first; | |
e3589f6c PZ |
6069 | |
6070 | return 0; | |
0601a88d | 6071 | } |
51888ca2 | 6072 | |
89c4710e | 6073 | /* |
63b2ca30 | 6074 | * Initialize sched groups cpu_capacity. |
89c4710e | 6075 | * |
63b2ca30 | 6076 | * cpu_capacity indicates the capacity of sched group, which is used while |
89c4710e | 6077 | * distributing the load between different sched groups in a sched domain. |
63b2ca30 NP |
6078 | * Typically cpu_capacity for all the groups in a sched domain will be same |
6079 | * unless there are asymmetries in the topology. If there are asymmetries, | |
6080 | * group having more cpu_capacity will pickup more load compared to the | |
6081 | * group having less cpu_capacity. | |
89c4710e | 6082 | */ |
63b2ca30 | 6083 | static void init_sched_groups_capacity(int cpu, struct sched_domain *sd) |
89c4710e | 6084 | { |
e3589f6c | 6085 | struct sched_group *sg = sd->groups; |
89c4710e | 6086 | |
94c95ba6 | 6087 | WARN_ON(!sg); |
e3589f6c PZ |
6088 | |
6089 | do { | |
6090 | sg->group_weight = cpumask_weight(sched_group_cpus(sg)); | |
6091 | sg = sg->next; | |
6092 | } while (sg != sd->groups); | |
89c4710e | 6093 | |
c1174876 | 6094 | if (cpu != group_balance_cpu(sg)) |
e3589f6c | 6095 | return; |
aae6d3dd | 6096 | |
63b2ca30 NP |
6097 | update_group_capacity(sd, cpu); |
6098 | atomic_set(&sg->sgc->nr_busy_cpus, sg->group_weight); | |
89c4710e SS |
6099 | } |
6100 | ||
7c16ec58 MT |
6101 | /* |
6102 | * Initializers for schedule domains | |
6103 | * Non-inlined to reduce accumulated stack pressure in build_sched_domains() | |
6104 | */ | |
6105 | ||
1d3504fc | 6106 | static int default_relax_domain_level = -1; |
60495e77 | 6107 | int sched_domain_level_max; |
1d3504fc HS |
6108 | |
6109 | static int __init setup_relax_domain_level(char *str) | |
6110 | { | |
a841f8ce DS |
6111 | if (kstrtoint(str, 0, &default_relax_domain_level)) |
6112 | pr_warn("Unable to set relax_domain_level\n"); | |
30e0e178 | 6113 | |
1d3504fc HS |
6114 | return 1; |
6115 | } | |
6116 | __setup("relax_domain_level=", setup_relax_domain_level); | |
6117 | ||
6118 | static void set_domain_attribute(struct sched_domain *sd, | |
6119 | struct sched_domain_attr *attr) | |
6120 | { | |
6121 | int request; | |
6122 | ||
6123 | if (!attr || attr->relax_domain_level < 0) { | |
6124 | if (default_relax_domain_level < 0) | |
6125 | return; | |
6126 | else | |
6127 | request = default_relax_domain_level; | |
6128 | } else | |
6129 | request = attr->relax_domain_level; | |
6130 | if (request < sd->level) { | |
6131 | /* turn off idle balance on this domain */ | |
c88d5910 | 6132 | sd->flags &= ~(SD_BALANCE_WAKE|SD_BALANCE_NEWIDLE); |
1d3504fc HS |
6133 | } else { |
6134 | /* turn on idle balance on this domain */ | |
c88d5910 | 6135 | sd->flags |= (SD_BALANCE_WAKE|SD_BALANCE_NEWIDLE); |
1d3504fc HS |
6136 | } |
6137 | } | |
6138 | ||
54ab4ff4 PZ |
6139 | static void __sdt_free(const struct cpumask *cpu_map); |
6140 | static int __sdt_alloc(const struct cpumask *cpu_map); | |
6141 | ||
2109b99e AH |
6142 | static void __free_domain_allocs(struct s_data *d, enum s_alloc what, |
6143 | const struct cpumask *cpu_map) | |
6144 | { | |
6145 | switch (what) { | |
2109b99e | 6146 | case sa_rootdomain: |
822ff793 PZ |
6147 | if (!atomic_read(&d->rd->refcount)) |
6148 | free_rootdomain(&d->rd->rcu); /* fall through */ | |
21d42ccf PZ |
6149 | case sa_sd: |
6150 | free_percpu(d->sd); /* fall through */ | |
dce840a0 | 6151 | case sa_sd_storage: |
54ab4ff4 | 6152 | __sdt_free(cpu_map); /* fall through */ |
2109b99e AH |
6153 | case sa_none: |
6154 | break; | |
6155 | } | |
6156 | } | |
3404c8d9 | 6157 | |
2109b99e AH |
6158 | static enum s_alloc __visit_domain_allocation_hell(struct s_data *d, |
6159 | const struct cpumask *cpu_map) | |
6160 | { | |
dce840a0 PZ |
6161 | memset(d, 0, sizeof(*d)); |
6162 | ||
54ab4ff4 PZ |
6163 | if (__sdt_alloc(cpu_map)) |
6164 | return sa_sd_storage; | |
dce840a0 PZ |
6165 | d->sd = alloc_percpu(struct sched_domain *); |
6166 | if (!d->sd) | |
6167 | return sa_sd_storage; | |
2109b99e | 6168 | d->rd = alloc_rootdomain(); |
dce840a0 | 6169 | if (!d->rd) |
21d42ccf | 6170 | return sa_sd; |
2109b99e AH |
6171 | return sa_rootdomain; |
6172 | } | |
57d885fe | 6173 | |
dce840a0 PZ |
6174 | /* |
6175 | * NULL the sd_data elements we've used to build the sched_domain and | |
6176 | * sched_group structure so that the subsequent __free_domain_allocs() | |
6177 | * will not free the data we're using. | |
6178 | */ | |
6179 | static void claim_allocations(int cpu, struct sched_domain *sd) | |
6180 | { | |
6181 | struct sd_data *sdd = sd->private; | |
dce840a0 PZ |
6182 | |
6183 | WARN_ON_ONCE(*per_cpu_ptr(sdd->sd, cpu) != sd); | |
6184 | *per_cpu_ptr(sdd->sd, cpu) = NULL; | |
6185 | ||
e3589f6c | 6186 | if (atomic_read(&(*per_cpu_ptr(sdd->sg, cpu))->ref)) |
dce840a0 | 6187 | *per_cpu_ptr(sdd->sg, cpu) = NULL; |
e3589f6c | 6188 | |
63b2ca30 NP |
6189 | if (atomic_read(&(*per_cpu_ptr(sdd->sgc, cpu))->ref)) |
6190 | *per_cpu_ptr(sdd->sgc, cpu) = NULL; | |
dce840a0 PZ |
6191 | } |
6192 | ||
cb83b629 | 6193 | #ifdef CONFIG_NUMA |
cb83b629 | 6194 | static int sched_domains_numa_levels; |
e3fe70b1 | 6195 | enum numa_topology_type sched_numa_topology_type; |
cb83b629 | 6196 | static int *sched_domains_numa_distance; |
9942f79b | 6197 | int sched_max_numa_distance; |
cb83b629 PZ |
6198 | static struct cpumask ***sched_domains_numa_masks; |
6199 | static int sched_domains_curr_level; | |
143e1e28 | 6200 | #endif |
cb83b629 | 6201 | |
143e1e28 VG |
6202 | /* |
6203 | * SD_flags allowed in topology descriptions. | |
6204 | * | |
5d4dfddd | 6205 | * SD_SHARE_CPUCAPACITY - describes SMT topologies |
143e1e28 VG |
6206 | * SD_SHARE_PKG_RESOURCES - describes shared caches |
6207 | * SD_NUMA - describes NUMA topologies | |
d77b3ed5 | 6208 | * SD_SHARE_POWERDOMAIN - describes shared power domain |
143e1e28 VG |
6209 | * |
6210 | * Odd one out: | |
6211 | * SD_ASYM_PACKING - describes SMT quirks | |
6212 | */ | |
6213 | #define TOPOLOGY_SD_FLAGS \ | |
5d4dfddd | 6214 | (SD_SHARE_CPUCAPACITY | \ |
143e1e28 VG |
6215 | SD_SHARE_PKG_RESOURCES | \ |
6216 | SD_NUMA | \ | |
d77b3ed5 VG |
6217 | SD_ASYM_PACKING | \ |
6218 | SD_SHARE_POWERDOMAIN) | |
cb83b629 PZ |
6219 | |
6220 | static struct sched_domain * | |
143e1e28 | 6221 | sd_init(struct sched_domain_topology_level *tl, int cpu) |
cb83b629 PZ |
6222 | { |
6223 | struct sched_domain *sd = *per_cpu_ptr(tl->data.sd, cpu); | |
143e1e28 VG |
6224 | int sd_weight, sd_flags = 0; |
6225 | ||
6226 | #ifdef CONFIG_NUMA | |
6227 | /* | |
6228 | * Ugly hack to pass state to sd_numa_mask()... | |
6229 | */ | |
6230 | sched_domains_curr_level = tl->numa_level; | |
6231 | #endif | |
6232 | ||
6233 | sd_weight = cpumask_weight(tl->mask(cpu)); | |
6234 | ||
6235 | if (tl->sd_flags) | |
6236 | sd_flags = (*tl->sd_flags)(); | |
6237 | if (WARN_ONCE(sd_flags & ~TOPOLOGY_SD_FLAGS, | |
6238 | "wrong sd_flags in topology description\n")) | |
6239 | sd_flags &= ~TOPOLOGY_SD_FLAGS; | |
cb83b629 PZ |
6240 | |
6241 | *sd = (struct sched_domain){ | |
6242 | .min_interval = sd_weight, | |
6243 | .max_interval = 2*sd_weight, | |
6244 | .busy_factor = 32, | |
870a0bb5 | 6245 | .imbalance_pct = 125, |
143e1e28 VG |
6246 | |
6247 | .cache_nice_tries = 0, | |
6248 | .busy_idx = 0, | |
6249 | .idle_idx = 0, | |
cb83b629 PZ |
6250 | .newidle_idx = 0, |
6251 | .wake_idx = 0, | |
6252 | .forkexec_idx = 0, | |
6253 | ||
6254 | .flags = 1*SD_LOAD_BALANCE | |
6255 | | 1*SD_BALANCE_NEWIDLE | |
143e1e28 VG |
6256 | | 1*SD_BALANCE_EXEC |
6257 | | 1*SD_BALANCE_FORK | |
cb83b629 | 6258 | | 0*SD_BALANCE_WAKE |
143e1e28 | 6259 | | 1*SD_WAKE_AFFINE |
5d4dfddd | 6260 | | 0*SD_SHARE_CPUCAPACITY |
cb83b629 | 6261 | | 0*SD_SHARE_PKG_RESOURCES |
143e1e28 | 6262 | | 0*SD_SERIALIZE |
cb83b629 | 6263 | | 0*SD_PREFER_SIBLING |
143e1e28 VG |
6264 | | 0*SD_NUMA |
6265 | | sd_flags | |
cb83b629 | 6266 | , |
143e1e28 | 6267 | |
cb83b629 PZ |
6268 | .last_balance = jiffies, |
6269 | .balance_interval = sd_weight, | |
143e1e28 | 6270 | .smt_gain = 0, |
2b4cfe64 JL |
6271 | .max_newidle_lb_cost = 0, |
6272 | .next_decay_max_lb_cost = jiffies, | |
143e1e28 VG |
6273 | #ifdef CONFIG_SCHED_DEBUG |
6274 | .name = tl->name, | |
6275 | #endif | |
cb83b629 | 6276 | }; |
cb83b629 PZ |
6277 | |
6278 | /* | |
143e1e28 | 6279 | * Convert topological properties into behaviour. |
cb83b629 | 6280 | */ |
143e1e28 | 6281 | |
5d4dfddd | 6282 | if (sd->flags & SD_SHARE_CPUCAPACITY) { |
143e1e28 VG |
6283 | sd->imbalance_pct = 110; |
6284 | sd->smt_gain = 1178; /* ~15% */ | |
143e1e28 VG |
6285 | |
6286 | } else if (sd->flags & SD_SHARE_PKG_RESOURCES) { | |
6287 | sd->imbalance_pct = 117; | |
6288 | sd->cache_nice_tries = 1; | |
6289 | sd->busy_idx = 2; | |
6290 | ||
6291 | #ifdef CONFIG_NUMA | |
6292 | } else if (sd->flags & SD_NUMA) { | |
6293 | sd->cache_nice_tries = 2; | |
6294 | sd->busy_idx = 3; | |
6295 | sd->idle_idx = 2; | |
6296 | ||
6297 | sd->flags |= SD_SERIALIZE; | |
6298 | if (sched_domains_numa_distance[tl->numa_level] > RECLAIM_DISTANCE) { | |
6299 | sd->flags &= ~(SD_BALANCE_EXEC | | |
6300 | SD_BALANCE_FORK | | |
6301 | SD_WAKE_AFFINE); | |
6302 | } | |
6303 | ||
6304 | #endif | |
6305 | } else { | |
6306 | sd->flags |= SD_PREFER_SIBLING; | |
6307 | sd->cache_nice_tries = 1; | |
6308 | sd->busy_idx = 2; | |
6309 | sd->idle_idx = 1; | |
6310 | } | |
6311 | ||
6312 | sd->private = &tl->data; | |
cb83b629 PZ |
6313 | |
6314 | return sd; | |
6315 | } | |
6316 | ||
143e1e28 VG |
6317 | /* |
6318 | * Topology list, bottom-up. | |
6319 | */ | |
6320 | static struct sched_domain_topology_level default_topology[] = { | |
6321 | #ifdef CONFIG_SCHED_SMT | |
6322 | { cpu_smt_mask, cpu_smt_flags, SD_INIT_NAME(SMT) }, | |
6323 | #endif | |
6324 | #ifdef CONFIG_SCHED_MC | |
6325 | { cpu_coregroup_mask, cpu_core_flags, SD_INIT_NAME(MC) }, | |
143e1e28 VG |
6326 | #endif |
6327 | { cpu_cpu_mask, SD_INIT_NAME(DIE) }, | |
6328 | { NULL, }, | |
6329 | }; | |
6330 | ||
6331 | struct sched_domain_topology_level *sched_domain_topology = default_topology; | |
6332 | ||
6333 | #define for_each_sd_topology(tl) \ | |
6334 | for (tl = sched_domain_topology; tl->mask; tl++) | |
6335 | ||
6336 | void set_sched_topology(struct sched_domain_topology_level *tl) | |
6337 | { | |
6338 | sched_domain_topology = tl; | |
6339 | } | |
6340 | ||
6341 | #ifdef CONFIG_NUMA | |
6342 | ||
cb83b629 PZ |
6343 | static const struct cpumask *sd_numa_mask(int cpu) |
6344 | { | |
6345 | return sched_domains_numa_masks[sched_domains_curr_level][cpu_to_node(cpu)]; | |
6346 | } | |
6347 | ||
d039ac60 PZ |
6348 | static void sched_numa_warn(const char *str) |
6349 | { | |
6350 | static int done = false; | |
6351 | int i,j; | |
6352 | ||
6353 | if (done) | |
6354 | return; | |
6355 | ||
6356 | done = true; | |
6357 | ||
6358 | printk(KERN_WARNING "ERROR: %s\n\n", str); | |
6359 | ||
6360 | for (i = 0; i < nr_node_ids; i++) { | |
6361 | printk(KERN_WARNING " "); | |
6362 | for (j = 0; j < nr_node_ids; j++) | |
6363 | printk(KERN_CONT "%02d ", node_distance(i,j)); | |
6364 | printk(KERN_CONT "\n"); | |
6365 | } | |
6366 | printk(KERN_WARNING "\n"); | |
6367 | } | |
6368 | ||
9942f79b | 6369 | bool find_numa_distance(int distance) |
d039ac60 PZ |
6370 | { |
6371 | int i; | |
6372 | ||
6373 | if (distance == node_distance(0, 0)) | |
6374 | return true; | |
6375 | ||
6376 | for (i = 0; i < sched_domains_numa_levels; i++) { | |
6377 | if (sched_domains_numa_distance[i] == distance) | |
6378 | return true; | |
6379 | } | |
6380 | ||
6381 | return false; | |
6382 | } | |
6383 | ||
e3fe70b1 RR |
6384 | /* |
6385 | * A system can have three types of NUMA topology: | |
6386 | * NUMA_DIRECT: all nodes are directly connected, or not a NUMA system | |
6387 | * NUMA_GLUELESS_MESH: some nodes reachable through intermediary nodes | |
6388 | * NUMA_BACKPLANE: nodes can reach other nodes through a backplane | |
6389 | * | |
6390 | * The difference between a glueless mesh topology and a backplane | |
6391 | * topology lies in whether communication between not directly | |
6392 | * connected nodes goes through intermediary nodes (where programs | |
6393 | * could run), or through backplane controllers. This affects | |
6394 | * placement of programs. | |
6395 | * | |
6396 | * The type of topology can be discerned with the following tests: | |
6397 | * - If the maximum distance between any nodes is 1 hop, the system | |
6398 | * is directly connected. | |
6399 | * - If for two nodes A and B, located N > 1 hops away from each other, | |
6400 | * there is an intermediary node C, which is < N hops away from both | |
6401 | * nodes A and B, the system is a glueless mesh. | |
6402 | */ | |
6403 | static void init_numa_topology_type(void) | |
6404 | { | |
6405 | int a, b, c, n; | |
6406 | ||
6407 | n = sched_max_numa_distance; | |
6408 | ||
6409 | if (n <= 1) | |
6410 | sched_numa_topology_type = NUMA_DIRECT; | |
6411 | ||
6412 | for_each_online_node(a) { | |
6413 | for_each_online_node(b) { | |
6414 | /* Find two nodes furthest removed from each other. */ | |
6415 | if (node_distance(a, b) < n) | |
6416 | continue; | |
6417 | ||
6418 | /* Is there an intermediary node between a and b? */ | |
6419 | for_each_online_node(c) { | |
6420 | if (node_distance(a, c) < n && | |
6421 | node_distance(b, c) < n) { | |
6422 | sched_numa_topology_type = | |
6423 | NUMA_GLUELESS_MESH; | |
6424 | return; | |
6425 | } | |
6426 | } | |
6427 | ||
6428 | sched_numa_topology_type = NUMA_BACKPLANE; | |
6429 | return; | |
6430 | } | |
6431 | } | |
6432 | } | |
6433 | ||
cb83b629 PZ |
6434 | static void sched_init_numa(void) |
6435 | { | |
6436 | int next_distance, curr_distance = node_distance(0, 0); | |
6437 | struct sched_domain_topology_level *tl; | |
6438 | int level = 0; | |
6439 | int i, j, k; | |
6440 | ||
cb83b629 PZ |
6441 | sched_domains_numa_distance = kzalloc(sizeof(int) * nr_node_ids, GFP_KERNEL); |
6442 | if (!sched_domains_numa_distance) | |
6443 | return; | |
6444 | ||
6445 | /* | |
6446 | * O(nr_nodes^2) deduplicating selection sort -- in order to find the | |
6447 | * unique distances in the node_distance() table. | |
6448 | * | |
6449 | * Assumes node_distance(0,j) includes all distances in | |
6450 | * node_distance(i,j) in order to avoid cubic time. | |
cb83b629 PZ |
6451 | */ |
6452 | next_distance = curr_distance; | |
6453 | for (i = 0; i < nr_node_ids; i++) { | |
6454 | for (j = 0; j < nr_node_ids; j++) { | |
d039ac60 PZ |
6455 | for (k = 0; k < nr_node_ids; k++) { |
6456 | int distance = node_distance(i, k); | |
6457 | ||
6458 | if (distance > curr_distance && | |
6459 | (distance < next_distance || | |
6460 | next_distance == curr_distance)) | |
6461 | next_distance = distance; | |
6462 | ||
6463 | /* | |
6464 | * While not a strong assumption it would be nice to know | |
6465 | * about cases where if node A is connected to B, B is not | |
6466 | * equally connected to A. | |
6467 | */ | |
6468 | if (sched_debug() && node_distance(k, i) != distance) | |
6469 | sched_numa_warn("Node-distance not symmetric"); | |
6470 | ||
6471 | if (sched_debug() && i && !find_numa_distance(distance)) | |
6472 | sched_numa_warn("Node-0 not representative"); | |
6473 | } | |
6474 | if (next_distance != curr_distance) { | |
6475 | sched_domains_numa_distance[level++] = next_distance; | |
6476 | sched_domains_numa_levels = level; | |
6477 | curr_distance = next_distance; | |
6478 | } else break; | |
cb83b629 | 6479 | } |
d039ac60 PZ |
6480 | |
6481 | /* | |
6482 | * In case of sched_debug() we verify the above assumption. | |
6483 | */ | |
6484 | if (!sched_debug()) | |
6485 | break; | |
cb83b629 | 6486 | } |
c123588b AR |
6487 | |
6488 | if (!level) | |
6489 | return; | |
6490 | ||
cb83b629 PZ |
6491 | /* |
6492 | * 'level' contains the number of unique distances, excluding the | |
6493 | * identity distance node_distance(i,i). | |
6494 | * | |
28b4a521 | 6495 | * The sched_domains_numa_distance[] array includes the actual distance |
cb83b629 PZ |
6496 | * numbers. |
6497 | */ | |
6498 | ||
5f7865f3 TC |
6499 | /* |
6500 | * Here, we should temporarily reset sched_domains_numa_levels to 0. | |
6501 | * If it fails to allocate memory for array sched_domains_numa_masks[][], | |
6502 | * the array will contain less then 'level' members. This could be | |
6503 | * dangerous when we use it to iterate array sched_domains_numa_masks[][] | |
6504 | * in other functions. | |
6505 | * | |
6506 | * We reset it to 'level' at the end of this function. | |
6507 | */ | |
6508 | sched_domains_numa_levels = 0; | |
6509 | ||
cb83b629 PZ |
6510 | sched_domains_numa_masks = kzalloc(sizeof(void *) * level, GFP_KERNEL); |
6511 | if (!sched_domains_numa_masks) | |
6512 | return; | |
6513 | ||
6514 | /* | |
6515 | * Now for each level, construct a mask per node which contains all | |
6516 | * cpus of nodes that are that many hops away from us. | |
6517 | */ | |
6518 | for (i = 0; i < level; i++) { | |
6519 | sched_domains_numa_masks[i] = | |
6520 | kzalloc(nr_node_ids * sizeof(void *), GFP_KERNEL); | |
6521 | if (!sched_domains_numa_masks[i]) | |
6522 | return; | |
6523 | ||
6524 | for (j = 0; j < nr_node_ids; j++) { | |
2ea45800 | 6525 | struct cpumask *mask = kzalloc(cpumask_size(), GFP_KERNEL); |
cb83b629 PZ |
6526 | if (!mask) |
6527 | return; | |
6528 | ||
6529 | sched_domains_numa_masks[i][j] = mask; | |
6530 | ||
6531 | for (k = 0; k < nr_node_ids; k++) { | |
dd7d8634 | 6532 | if (node_distance(j, k) > sched_domains_numa_distance[i]) |
cb83b629 PZ |
6533 | continue; |
6534 | ||
6535 | cpumask_or(mask, mask, cpumask_of_node(k)); | |
6536 | } | |
6537 | } | |
6538 | } | |
6539 | ||
143e1e28 VG |
6540 | /* Compute default topology size */ |
6541 | for (i = 0; sched_domain_topology[i].mask; i++); | |
6542 | ||
c515db8c | 6543 | tl = kzalloc((i + level + 1) * |
cb83b629 PZ |
6544 | sizeof(struct sched_domain_topology_level), GFP_KERNEL); |
6545 | if (!tl) | |
6546 | return; | |
6547 | ||
6548 | /* | |
6549 | * Copy the default topology bits.. | |
6550 | */ | |
143e1e28 VG |
6551 | for (i = 0; sched_domain_topology[i].mask; i++) |
6552 | tl[i] = sched_domain_topology[i]; | |
cb83b629 PZ |
6553 | |
6554 | /* | |
6555 | * .. and append 'j' levels of NUMA goodness. | |
6556 | */ | |
6557 | for (j = 0; j < level; i++, j++) { | |
6558 | tl[i] = (struct sched_domain_topology_level){ | |
cb83b629 | 6559 | .mask = sd_numa_mask, |
143e1e28 | 6560 | .sd_flags = cpu_numa_flags, |
cb83b629 PZ |
6561 | .flags = SDTL_OVERLAP, |
6562 | .numa_level = j, | |
143e1e28 | 6563 | SD_INIT_NAME(NUMA) |
cb83b629 PZ |
6564 | }; |
6565 | } | |
6566 | ||
6567 | sched_domain_topology = tl; | |
5f7865f3 TC |
6568 | |
6569 | sched_domains_numa_levels = level; | |
9942f79b | 6570 | sched_max_numa_distance = sched_domains_numa_distance[level - 1]; |
e3fe70b1 RR |
6571 | |
6572 | init_numa_topology_type(); | |
cb83b629 | 6573 | } |
301a5cba TC |
6574 | |
6575 | static void sched_domains_numa_masks_set(int cpu) | |
6576 | { | |
6577 | int i, j; | |
6578 | int node = cpu_to_node(cpu); | |
6579 | ||
6580 | for (i = 0; i < sched_domains_numa_levels; i++) { | |
6581 | for (j = 0; j < nr_node_ids; j++) { | |
6582 | if (node_distance(j, node) <= sched_domains_numa_distance[i]) | |
6583 | cpumask_set_cpu(cpu, sched_domains_numa_masks[i][j]); | |
6584 | } | |
6585 | } | |
6586 | } | |
6587 | ||
6588 | static void sched_domains_numa_masks_clear(int cpu) | |
6589 | { | |
6590 | int i, j; | |
6591 | for (i = 0; i < sched_domains_numa_levels; i++) { | |
6592 | for (j = 0; j < nr_node_ids; j++) | |
6593 | cpumask_clear_cpu(cpu, sched_domains_numa_masks[i][j]); | |
6594 | } | |
6595 | } | |
6596 | ||
6597 | /* | |
6598 | * Update sched_domains_numa_masks[level][node] array when new cpus | |
6599 | * are onlined. | |
6600 | */ | |
6601 | static int sched_domains_numa_masks_update(struct notifier_block *nfb, | |
6602 | unsigned long action, | |
6603 | void *hcpu) | |
6604 | { | |
6605 | int cpu = (long)hcpu; | |
6606 | ||
6607 | switch (action & ~CPU_TASKS_FROZEN) { | |
6608 | case CPU_ONLINE: | |
6609 | sched_domains_numa_masks_set(cpu); | |
6610 | break; | |
6611 | ||
6612 | case CPU_DEAD: | |
6613 | sched_domains_numa_masks_clear(cpu); | |
6614 | break; | |
6615 | ||
6616 | default: | |
6617 | return NOTIFY_DONE; | |
6618 | } | |
6619 | ||
6620 | return NOTIFY_OK; | |
cb83b629 PZ |
6621 | } |
6622 | #else | |
6623 | static inline void sched_init_numa(void) | |
6624 | { | |
6625 | } | |
301a5cba TC |
6626 | |
6627 | static int sched_domains_numa_masks_update(struct notifier_block *nfb, | |
6628 | unsigned long action, | |
6629 | void *hcpu) | |
6630 | { | |
6631 | return 0; | |
6632 | } | |
cb83b629 PZ |
6633 | #endif /* CONFIG_NUMA */ |
6634 | ||
54ab4ff4 PZ |
6635 | static int __sdt_alloc(const struct cpumask *cpu_map) |
6636 | { | |
6637 | struct sched_domain_topology_level *tl; | |
6638 | int j; | |
6639 | ||
27723a68 | 6640 | for_each_sd_topology(tl) { |
54ab4ff4 PZ |
6641 | struct sd_data *sdd = &tl->data; |
6642 | ||
6643 | sdd->sd = alloc_percpu(struct sched_domain *); | |
6644 | if (!sdd->sd) | |
6645 | return -ENOMEM; | |
6646 | ||
6647 | sdd->sg = alloc_percpu(struct sched_group *); | |
6648 | if (!sdd->sg) | |
6649 | return -ENOMEM; | |
6650 | ||
63b2ca30 NP |
6651 | sdd->sgc = alloc_percpu(struct sched_group_capacity *); |
6652 | if (!sdd->sgc) | |
9c3f75cb PZ |
6653 | return -ENOMEM; |
6654 | ||
54ab4ff4 PZ |
6655 | for_each_cpu(j, cpu_map) { |
6656 | struct sched_domain *sd; | |
6657 | struct sched_group *sg; | |
63b2ca30 | 6658 | struct sched_group_capacity *sgc; |
54ab4ff4 PZ |
6659 | |
6660 | sd = kzalloc_node(sizeof(struct sched_domain) + cpumask_size(), | |
6661 | GFP_KERNEL, cpu_to_node(j)); | |
6662 | if (!sd) | |
6663 | return -ENOMEM; | |
6664 | ||
6665 | *per_cpu_ptr(sdd->sd, j) = sd; | |
6666 | ||
6667 | sg = kzalloc_node(sizeof(struct sched_group) + cpumask_size(), | |
6668 | GFP_KERNEL, cpu_to_node(j)); | |
6669 | if (!sg) | |
6670 | return -ENOMEM; | |
6671 | ||
30b4e9eb IM |
6672 | sg->next = sg; |
6673 | ||
54ab4ff4 | 6674 | *per_cpu_ptr(sdd->sg, j) = sg; |
9c3f75cb | 6675 | |
63b2ca30 | 6676 | sgc = kzalloc_node(sizeof(struct sched_group_capacity) + cpumask_size(), |
9c3f75cb | 6677 | GFP_KERNEL, cpu_to_node(j)); |
63b2ca30 | 6678 | if (!sgc) |
9c3f75cb PZ |
6679 | return -ENOMEM; |
6680 | ||
63b2ca30 | 6681 | *per_cpu_ptr(sdd->sgc, j) = sgc; |
54ab4ff4 PZ |
6682 | } |
6683 | } | |
6684 | ||
6685 | return 0; | |
6686 | } | |
6687 | ||
6688 | static void __sdt_free(const struct cpumask *cpu_map) | |
6689 | { | |
6690 | struct sched_domain_topology_level *tl; | |
6691 | int j; | |
6692 | ||
27723a68 | 6693 | for_each_sd_topology(tl) { |
54ab4ff4 PZ |
6694 | struct sd_data *sdd = &tl->data; |
6695 | ||
6696 | for_each_cpu(j, cpu_map) { | |
fb2cf2c6 | 6697 | struct sched_domain *sd; |
6698 | ||
6699 | if (sdd->sd) { | |
6700 | sd = *per_cpu_ptr(sdd->sd, j); | |
6701 | if (sd && (sd->flags & SD_OVERLAP)) | |
6702 | free_sched_groups(sd->groups, 0); | |
6703 | kfree(*per_cpu_ptr(sdd->sd, j)); | |
6704 | } | |
6705 | ||
6706 | if (sdd->sg) | |
6707 | kfree(*per_cpu_ptr(sdd->sg, j)); | |
63b2ca30 NP |
6708 | if (sdd->sgc) |
6709 | kfree(*per_cpu_ptr(sdd->sgc, j)); | |
54ab4ff4 PZ |
6710 | } |
6711 | free_percpu(sdd->sd); | |
fb2cf2c6 | 6712 | sdd->sd = NULL; |
54ab4ff4 | 6713 | free_percpu(sdd->sg); |
fb2cf2c6 | 6714 | sdd->sg = NULL; |
63b2ca30 NP |
6715 | free_percpu(sdd->sgc); |
6716 | sdd->sgc = NULL; | |
54ab4ff4 PZ |
6717 | } |
6718 | } | |
6719 | ||
2c402dc3 | 6720 | struct sched_domain *build_sched_domain(struct sched_domain_topology_level *tl, |
4a850cbe VK |
6721 | const struct cpumask *cpu_map, struct sched_domain_attr *attr, |
6722 | struct sched_domain *child, int cpu) | |
2c402dc3 | 6723 | { |
143e1e28 | 6724 | struct sched_domain *sd = sd_init(tl, cpu); |
2c402dc3 | 6725 | if (!sd) |
d069b916 | 6726 | return child; |
2c402dc3 | 6727 | |
2c402dc3 | 6728 | cpumask_and(sched_domain_span(sd), cpu_map, tl->mask(cpu)); |
60495e77 PZ |
6729 | if (child) { |
6730 | sd->level = child->level + 1; | |
6731 | sched_domain_level_max = max(sched_domain_level_max, sd->level); | |
d069b916 | 6732 | child->parent = sd; |
c75e0128 | 6733 | sd->child = child; |
6ae72dff PZ |
6734 | |
6735 | if (!cpumask_subset(sched_domain_span(child), | |
6736 | sched_domain_span(sd))) { | |
6737 | pr_err("BUG: arch topology borken\n"); | |
6738 | #ifdef CONFIG_SCHED_DEBUG | |
6739 | pr_err(" the %s domain not a subset of the %s domain\n", | |
6740 | child->name, sd->name); | |
6741 | #endif | |
6742 | /* Fixup, ensure @sd has at least @child cpus. */ | |
6743 | cpumask_or(sched_domain_span(sd), | |
6744 | sched_domain_span(sd), | |
6745 | sched_domain_span(child)); | |
6746 | } | |
6747 | ||
60495e77 | 6748 | } |
a841f8ce | 6749 | set_domain_attribute(sd, attr); |
2c402dc3 PZ |
6750 | |
6751 | return sd; | |
6752 | } | |
6753 | ||
2109b99e AH |
6754 | /* |
6755 | * Build sched domains for a given set of cpus and attach the sched domains | |
6756 | * to the individual cpus | |
6757 | */ | |
dce840a0 PZ |
6758 | static int build_sched_domains(const struct cpumask *cpu_map, |
6759 | struct sched_domain_attr *attr) | |
2109b99e | 6760 | { |
1c632169 | 6761 | enum s_alloc alloc_state; |
dce840a0 | 6762 | struct sched_domain *sd; |
2109b99e | 6763 | struct s_data d; |
822ff793 | 6764 | int i, ret = -ENOMEM; |
9c1cfda2 | 6765 | |
2109b99e AH |
6766 | alloc_state = __visit_domain_allocation_hell(&d, cpu_map); |
6767 | if (alloc_state != sa_rootdomain) | |
6768 | goto error; | |
9c1cfda2 | 6769 | |
dce840a0 | 6770 | /* Set up domains for cpus specified by the cpu_map. */ |
abcd083a | 6771 | for_each_cpu(i, cpu_map) { |
eb7a74e6 PZ |
6772 | struct sched_domain_topology_level *tl; |
6773 | ||
3bd65a80 | 6774 | sd = NULL; |
27723a68 | 6775 | for_each_sd_topology(tl) { |
4a850cbe | 6776 | sd = build_sched_domain(tl, cpu_map, attr, sd, i); |
22da9569 VK |
6777 | if (tl == sched_domain_topology) |
6778 | *per_cpu_ptr(d.sd, i) = sd; | |
e3589f6c PZ |
6779 | if (tl->flags & SDTL_OVERLAP || sched_feat(FORCE_SD_OVERLAP)) |
6780 | sd->flags |= SD_OVERLAP; | |
d110235d PZ |
6781 | if (cpumask_equal(cpu_map, sched_domain_span(sd))) |
6782 | break; | |
e3589f6c | 6783 | } |
dce840a0 PZ |
6784 | } |
6785 | ||
6786 | /* Build the groups for the domains */ | |
6787 | for_each_cpu(i, cpu_map) { | |
6788 | for (sd = *per_cpu_ptr(d.sd, i); sd; sd = sd->parent) { | |
6789 | sd->span_weight = cpumask_weight(sched_domain_span(sd)); | |
e3589f6c PZ |
6790 | if (sd->flags & SD_OVERLAP) { |
6791 | if (build_overlap_sched_groups(sd, i)) | |
6792 | goto error; | |
6793 | } else { | |
6794 | if (build_sched_groups(sd, i)) | |
6795 | goto error; | |
6796 | } | |
1cf51902 | 6797 | } |
a06dadbe | 6798 | } |
9c1cfda2 | 6799 | |
ced549fa | 6800 | /* Calculate CPU capacity for physical packages and nodes */ |
a9c9a9b6 PZ |
6801 | for (i = nr_cpumask_bits-1; i >= 0; i--) { |
6802 | if (!cpumask_test_cpu(i, cpu_map)) | |
6803 | continue; | |
9c1cfda2 | 6804 | |
dce840a0 PZ |
6805 | for (sd = *per_cpu_ptr(d.sd, i); sd; sd = sd->parent) { |
6806 | claim_allocations(i, sd); | |
63b2ca30 | 6807 | init_sched_groups_capacity(i, sd); |
dce840a0 | 6808 | } |
f712c0c7 | 6809 | } |
9c1cfda2 | 6810 | |
1da177e4 | 6811 | /* Attach the domains */ |
dce840a0 | 6812 | rcu_read_lock(); |
abcd083a | 6813 | for_each_cpu(i, cpu_map) { |
21d42ccf | 6814 | sd = *per_cpu_ptr(d.sd, i); |
49a02c51 | 6815 | cpu_attach_domain(sd, d.rd, i); |
1da177e4 | 6816 | } |
dce840a0 | 6817 | rcu_read_unlock(); |
51888ca2 | 6818 | |
822ff793 | 6819 | ret = 0; |
51888ca2 | 6820 | error: |
2109b99e | 6821 | __free_domain_allocs(&d, alloc_state, cpu_map); |
822ff793 | 6822 | return ret; |
1da177e4 | 6823 | } |
029190c5 | 6824 | |
acc3f5d7 | 6825 | static cpumask_var_t *doms_cur; /* current sched domains */ |
029190c5 | 6826 | static int ndoms_cur; /* number of sched domains in 'doms_cur' */ |
4285f594 IM |
6827 | static struct sched_domain_attr *dattr_cur; |
6828 | /* attribues of custom domains in 'doms_cur' */ | |
029190c5 PJ |
6829 | |
6830 | /* | |
6831 | * Special case: If a kmalloc of a doms_cur partition (array of | |
4212823f RR |
6832 | * cpumask) fails, then fallback to a single sched domain, |
6833 | * as determined by the single cpumask fallback_doms. | |
029190c5 | 6834 | */ |
4212823f | 6835 | static cpumask_var_t fallback_doms; |
029190c5 | 6836 | |
ee79d1bd HC |
6837 | /* |
6838 | * arch_update_cpu_topology lets virtualized architectures update the | |
6839 | * cpu core maps. It is supposed to return 1 if the topology changed | |
6840 | * or 0 if it stayed the same. | |
6841 | */ | |
52f5684c | 6842 | int __weak arch_update_cpu_topology(void) |
22e52b07 | 6843 | { |
ee79d1bd | 6844 | return 0; |
22e52b07 HC |
6845 | } |
6846 | ||
acc3f5d7 RR |
6847 | cpumask_var_t *alloc_sched_domains(unsigned int ndoms) |
6848 | { | |
6849 | int i; | |
6850 | cpumask_var_t *doms; | |
6851 | ||
6852 | doms = kmalloc(sizeof(*doms) * ndoms, GFP_KERNEL); | |
6853 | if (!doms) | |
6854 | return NULL; | |
6855 | for (i = 0; i < ndoms; i++) { | |
6856 | if (!alloc_cpumask_var(&doms[i], GFP_KERNEL)) { | |
6857 | free_sched_domains(doms, i); | |
6858 | return NULL; | |
6859 | } | |
6860 | } | |
6861 | return doms; | |
6862 | } | |
6863 | ||
6864 | void free_sched_domains(cpumask_var_t doms[], unsigned int ndoms) | |
6865 | { | |
6866 | unsigned int i; | |
6867 | for (i = 0; i < ndoms; i++) | |
6868 | free_cpumask_var(doms[i]); | |
6869 | kfree(doms); | |
6870 | } | |
6871 | ||
1a20ff27 | 6872 | /* |
41a2d6cf | 6873 | * Set up scheduler domains and groups. Callers must hold the hotplug lock. |
029190c5 PJ |
6874 | * For now this just excludes isolated cpus, but could be used to |
6875 | * exclude other special cases in the future. | |
1a20ff27 | 6876 | */ |
c4a8849a | 6877 | static int init_sched_domains(const struct cpumask *cpu_map) |
1a20ff27 | 6878 | { |
7378547f MM |
6879 | int err; |
6880 | ||
22e52b07 | 6881 | arch_update_cpu_topology(); |
029190c5 | 6882 | ndoms_cur = 1; |
acc3f5d7 | 6883 | doms_cur = alloc_sched_domains(ndoms_cur); |
029190c5 | 6884 | if (!doms_cur) |
acc3f5d7 RR |
6885 | doms_cur = &fallback_doms; |
6886 | cpumask_andnot(doms_cur[0], cpu_map, cpu_isolated_map); | |
dce840a0 | 6887 | err = build_sched_domains(doms_cur[0], NULL); |
6382bc90 | 6888 | register_sched_domain_sysctl(); |
7378547f MM |
6889 | |
6890 | return err; | |
1a20ff27 DG |
6891 | } |
6892 | ||
1a20ff27 DG |
6893 | /* |
6894 | * Detach sched domains from a group of cpus specified in cpu_map | |
6895 | * These cpus will now be attached to the NULL domain | |
6896 | */ | |
96f874e2 | 6897 | static void detach_destroy_domains(const struct cpumask *cpu_map) |
1a20ff27 DG |
6898 | { |
6899 | int i; | |
6900 | ||
dce840a0 | 6901 | rcu_read_lock(); |
abcd083a | 6902 | for_each_cpu(i, cpu_map) |
57d885fe | 6903 | cpu_attach_domain(NULL, &def_root_domain, i); |
dce840a0 | 6904 | rcu_read_unlock(); |
1a20ff27 DG |
6905 | } |
6906 | ||
1d3504fc HS |
6907 | /* handle null as "default" */ |
6908 | static int dattrs_equal(struct sched_domain_attr *cur, int idx_cur, | |
6909 | struct sched_domain_attr *new, int idx_new) | |
6910 | { | |
6911 | struct sched_domain_attr tmp; | |
6912 | ||
6913 | /* fast path */ | |
6914 | if (!new && !cur) | |
6915 | return 1; | |
6916 | ||
6917 | tmp = SD_ATTR_INIT; | |
6918 | return !memcmp(cur ? (cur + idx_cur) : &tmp, | |
6919 | new ? (new + idx_new) : &tmp, | |
6920 | sizeof(struct sched_domain_attr)); | |
6921 | } | |
6922 | ||
029190c5 PJ |
6923 | /* |
6924 | * Partition sched domains as specified by the 'ndoms_new' | |
41a2d6cf | 6925 | * cpumasks in the array doms_new[] of cpumasks. This compares |
029190c5 PJ |
6926 | * doms_new[] to the current sched domain partitioning, doms_cur[]. |
6927 | * It destroys each deleted domain and builds each new domain. | |
6928 | * | |
acc3f5d7 | 6929 | * 'doms_new' is an array of cpumask_var_t's of length 'ndoms_new'. |
41a2d6cf IM |
6930 | * The masks don't intersect (don't overlap.) We should setup one |
6931 | * sched domain for each mask. CPUs not in any of the cpumasks will | |
6932 | * not be load balanced. If the same cpumask appears both in the | |
029190c5 PJ |
6933 | * current 'doms_cur' domains and in the new 'doms_new', we can leave |
6934 | * it as it is. | |
6935 | * | |
acc3f5d7 RR |
6936 | * The passed in 'doms_new' should be allocated using |
6937 | * alloc_sched_domains. This routine takes ownership of it and will | |
6938 | * free_sched_domains it when done with it. If the caller failed the | |
6939 | * alloc call, then it can pass in doms_new == NULL && ndoms_new == 1, | |
6940 | * and partition_sched_domains() will fallback to the single partition | |
6941 | * 'fallback_doms', it also forces the domains to be rebuilt. | |
029190c5 | 6942 | * |
96f874e2 | 6943 | * If doms_new == NULL it will be replaced with cpu_online_mask. |
700018e0 LZ |
6944 | * ndoms_new == 0 is a special case for destroying existing domains, |
6945 | * and it will not create the default domain. | |
dfb512ec | 6946 | * |
029190c5 PJ |
6947 | * Call with hotplug lock held |
6948 | */ | |
acc3f5d7 | 6949 | void partition_sched_domains(int ndoms_new, cpumask_var_t doms_new[], |
1d3504fc | 6950 | struct sched_domain_attr *dattr_new) |
029190c5 | 6951 | { |
dfb512ec | 6952 | int i, j, n; |
d65bd5ec | 6953 | int new_topology; |
029190c5 | 6954 | |
712555ee | 6955 | mutex_lock(&sched_domains_mutex); |
a1835615 | 6956 | |
7378547f MM |
6957 | /* always unregister in case we don't destroy any domains */ |
6958 | unregister_sched_domain_sysctl(); | |
6959 | ||
d65bd5ec HC |
6960 | /* Let architecture update cpu core mappings. */ |
6961 | new_topology = arch_update_cpu_topology(); | |
6962 | ||
dfb512ec | 6963 | n = doms_new ? ndoms_new : 0; |
029190c5 PJ |
6964 | |
6965 | /* Destroy deleted domains */ | |
6966 | for (i = 0; i < ndoms_cur; i++) { | |
d65bd5ec | 6967 | for (j = 0; j < n && !new_topology; j++) { |
acc3f5d7 | 6968 | if (cpumask_equal(doms_cur[i], doms_new[j]) |
1d3504fc | 6969 | && dattrs_equal(dattr_cur, i, dattr_new, j)) |
029190c5 PJ |
6970 | goto match1; |
6971 | } | |
6972 | /* no match - a current sched domain not in new doms_new[] */ | |
acc3f5d7 | 6973 | detach_destroy_domains(doms_cur[i]); |
029190c5 PJ |
6974 | match1: |
6975 | ; | |
6976 | } | |
6977 | ||
c8d2d47a | 6978 | n = ndoms_cur; |
e761b772 | 6979 | if (doms_new == NULL) { |
c8d2d47a | 6980 | n = 0; |
acc3f5d7 | 6981 | doms_new = &fallback_doms; |
6ad4c188 | 6982 | cpumask_andnot(doms_new[0], cpu_active_mask, cpu_isolated_map); |
faa2f98f | 6983 | WARN_ON_ONCE(dattr_new); |
e761b772 MK |
6984 | } |
6985 | ||
029190c5 PJ |
6986 | /* Build new domains */ |
6987 | for (i = 0; i < ndoms_new; i++) { | |
c8d2d47a | 6988 | for (j = 0; j < n && !new_topology; j++) { |
acc3f5d7 | 6989 | if (cpumask_equal(doms_new[i], doms_cur[j]) |
1d3504fc | 6990 | && dattrs_equal(dattr_new, i, dattr_cur, j)) |
029190c5 PJ |
6991 | goto match2; |
6992 | } | |
6993 | /* no match - add a new doms_new */ | |
dce840a0 | 6994 | build_sched_domains(doms_new[i], dattr_new ? dattr_new + i : NULL); |
029190c5 PJ |
6995 | match2: |
6996 | ; | |
6997 | } | |
6998 | ||
6999 | /* Remember the new sched domains */ | |
acc3f5d7 RR |
7000 | if (doms_cur != &fallback_doms) |
7001 | free_sched_domains(doms_cur, ndoms_cur); | |
1d3504fc | 7002 | kfree(dattr_cur); /* kfree(NULL) is safe */ |
029190c5 | 7003 | doms_cur = doms_new; |
1d3504fc | 7004 | dattr_cur = dattr_new; |
029190c5 | 7005 | ndoms_cur = ndoms_new; |
7378547f MM |
7006 | |
7007 | register_sched_domain_sysctl(); | |
a1835615 | 7008 | |
712555ee | 7009 | mutex_unlock(&sched_domains_mutex); |
029190c5 PJ |
7010 | } |
7011 | ||
d35be8ba SB |
7012 | static int num_cpus_frozen; /* used to mark begin/end of suspend/resume */ |
7013 | ||
1da177e4 | 7014 | /* |
3a101d05 TH |
7015 | * Update cpusets according to cpu_active mask. If cpusets are |
7016 | * disabled, cpuset_update_active_cpus() becomes a simple wrapper | |
7017 | * around partition_sched_domains(). | |
d35be8ba SB |
7018 | * |
7019 | * If we come here as part of a suspend/resume, don't touch cpusets because we | |
7020 | * want to restore it back to its original state upon resume anyway. | |
1da177e4 | 7021 | */ |
0b2e918a TH |
7022 | static int cpuset_cpu_active(struct notifier_block *nfb, unsigned long action, |
7023 | void *hcpu) | |
e761b772 | 7024 | { |
d35be8ba SB |
7025 | switch (action) { |
7026 | case CPU_ONLINE_FROZEN: | |
7027 | case CPU_DOWN_FAILED_FROZEN: | |
7028 | ||
7029 | /* | |
7030 | * num_cpus_frozen tracks how many CPUs are involved in suspend | |
7031 | * resume sequence. As long as this is not the last online | |
7032 | * operation in the resume sequence, just build a single sched | |
7033 | * domain, ignoring cpusets. | |
7034 | */ | |
7035 | num_cpus_frozen--; | |
7036 | if (likely(num_cpus_frozen)) { | |
7037 | partition_sched_domains(1, NULL, NULL); | |
7038 | break; | |
7039 | } | |
7040 | ||
7041 | /* | |
7042 | * This is the last CPU online operation. So fall through and | |
7043 | * restore the original sched domains by considering the | |
7044 | * cpuset configurations. | |
7045 | */ | |
7046 | ||
e761b772 | 7047 | case CPU_ONLINE: |
6ad4c188 | 7048 | case CPU_DOWN_FAILED: |
7ddf96b0 | 7049 | cpuset_update_active_cpus(true); |
d35be8ba | 7050 | break; |
3a101d05 TH |
7051 | default: |
7052 | return NOTIFY_DONE; | |
7053 | } | |
d35be8ba | 7054 | return NOTIFY_OK; |
3a101d05 | 7055 | } |
e761b772 | 7056 | |
0b2e918a TH |
7057 | static int cpuset_cpu_inactive(struct notifier_block *nfb, unsigned long action, |
7058 | void *hcpu) | |
3a101d05 | 7059 | { |
d35be8ba | 7060 | switch (action) { |
3a101d05 | 7061 | case CPU_DOWN_PREPARE: |
7ddf96b0 | 7062 | cpuset_update_active_cpus(false); |
d35be8ba SB |
7063 | break; |
7064 | case CPU_DOWN_PREPARE_FROZEN: | |
7065 | num_cpus_frozen++; | |
7066 | partition_sched_domains(1, NULL, NULL); | |
7067 | break; | |
e761b772 MK |
7068 | default: |
7069 | return NOTIFY_DONE; | |
7070 | } | |
d35be8ba | 7071 | return NOTIFY_OK; |
e761b772 | 7072 | } |
e761b772 | 7073 | |
1da177e4 LT |
7074 | void __init sched_init_smp(void) |
7075 | { | |
dcc30a35 RR |
7076 | cpumask_var_t non_isolated_cpus; |
7077 | ||
7078 | alloc_cpumask_var(&non_isolated_cpus, GFP_KERNEL); | |
cb5fd13f | 7079 | alloc_cpumask_var(&fallback_doms, GFP_KERNEL); |
5c1e1767 | 7080 | |
cb83b629 PZ |
7081 | sched_init_numa(); |
7082 | ||
6acce3ef PZ |
7083 | /* |
7084 | * There's no userspace yet to cause hotplug operations; hence all the | |
7085 | * cpu masks are stable and all blatant races in the below code cannot | |
7086 | * happen. | |
7087 | */ | |
712555ee | 7088 | mutex_lock(&sched_domains_mutex); |
c4a8849a | 7089 | init_sched_domains(cpu_active_mask); |
dcc30a35 RR |
7090 | cpumask_andnot(non_isolated_cpus, cpu_possible_mask, cpu_isolated_map); |
7091 | if (cpumask_empty(non_isolated_cpus)) | |
7092 | cpumask_set_cpu(smp_processor_id(), non_isolated_cpus); | |
712555ee | 7093 | mutex_unlock(&sched_domains_mutex); |
e761b772 | 7094 | |
301a5cba | 7095 | hotcpu_notifier(sched_domains_numa_masks_update, CPU_PRI_SCHED_ACTIVE); |
3a101d05 TH |
7096 | hotcpu_notifier(cpuset_cpu_active, CPU_PRI_CPUSET_ACTIVE); |
7097 | hotcpu_notifier(cpuset_cpu_inactive, CPU_PRI_CPUSET_INACTIVE); | |
e761b772 | 7098 | |
b328ca18 | 7099 | init_hrtick(); |
5c1e1767 NP |
7100 | |
7101 | /* Move init over to a non-isolated CPU */ | |
dcc30a35 | 7102 | if (set_cpus_allowed_ptr(current, non_isolated_cpus) < 0) |
5c1e1767 | 7103 | BUG(); |
19978ca6 | 7104 | sched_init_granularity(); |
dcc30a35 | 7105 | free_cpumask_var(non_isolated_cpus); |
4212823f | 7106 | |
0e3900e6 | 7107 | init_sched_rt_class(); |
1baca4ce | 7108 | init_sched_dl_class(); |
1da177e4 LT |
7109 | } |
7110 | #else | |
7111 | void __init sched_init_smp(void) | |
7112 | { | |
19978ca6 | 7113 | sched_init_granularity(); |
1da177e4 LT |
7114 | } |
7115 | #endif /* CONFIG_SMP */ | |
7116 | ||
cd1bb94b AB |
7117 | const_debug unsigned int sysctl_timer_migration = 1; |
7118 | ||
1da177e4 LT |
7119 | int in_sched_functions(unsigned long addr) |
7120 | { | |
1da177e4 LT |
7121 | return in_lock_functions(addr) || |
7122 | (addr >= (unsigned long)__sched_text_start | |
7123 | && addr < (unsigned long)__sched_text_end); | |
7124 | } | |
7125 | ||
029632fb | 7126 | #ifdef CONFIG_CGROUP_SCHED |
27b4b931 LZ |
7127 | /* |
7128 | * Default task group. | |
7129 | * Every task in system belongs to this group at bootup. | |
7130 | */ | |
029632fb | 7131 | struct task_group root_task_group; |
35cf4e50 | 7132 | LIST_HEAD(task_groups); |
052f1dc7 | 7133 | #endif |
6f505b16 | 7134 | |
e6252c3e | 7135 | DECLARE_PER_CPU(cpumask_var_t, load_balance_mask); |
6f505b16 | 7136 | |
1da177e4 LT |
7137 | void __init sched_init(void) |
7138 | { | |
dd41f596 | 7139 | int i, j; |
434d53b0 MT |
7140 | unsigned long alloc_size = 0, ptr; |
7141 | ||
7142 | #ifdef CONFIG_FAIR_GROUP_SCHED | |
7143 | alloc_size += 2 * nr_cpu_ids * sizeof(void **); | |
7144 | #endif | |
7145 | #ifdef CONFIG_RT_GROUP_SCHED | |
7146 | alloc_size += 2 * nr_cpu_ids * sizeof(void **); | |
7147 | #endif | |
434d53b0 | 7148 | if (alloc_size) { |
36b7b6d4 | 7149 | ptr = (unsigned long)kzalloc(alloc_size, GFP_NOWAIT); |
434d53b0 MT |
7150 | |
7151 | #ifdef CONFIG_FAIR_GROUP_SCHED | |
07e06b01 | 7152 | root_task_group.se = (struct sched_entity **)ptr; |
434d53b0 MT |
7153 | ptr += nr_cpu_ids * sizeof(void **); |
7154 | ||
07e06b01 | 7155 | root_task_group.cfs_rq = (struct cfs_rq **)ptr; |
434d53b0 | 7156 | ptr += nr_cpu_ids * sizeof(void **); |
eff766a6 | 7157 | |
6d6bc0ad | 7158 | #endif /* CONFIG_FAIR_GROUP_SCHED */ |
434d53b0 | 7159 | #ifdef CONFIG_RT_GROUP_SCHED |
07e06b01 | 7160 | root_task_group.rt_se = (struct sched_rt_entity **)ptr; |
434d53b0 MT |
7161 | ptr += nr_cpu_ids * sizeof(void **); |
7162 | ||
07e06b01 | 7163 | root_task_group.rt_rq = (struct rt_rq **)ptr; |
eff766a6 PZ |
7164 | ptr += nr_cpu_ids * sizeof(void **); |
7165 | ||
6d6bc0ad | 7166 | #endif /* CONFIG_RT_GROUP_SCHED */ |
b74e6278 | 7167 | } |
df7c8e84 | 7168 | #ifdef CONFIG_CPUMASK_OFFSTACK |
b74e6278 AT |
7169 | for_each_possible_cpu(i) { |
7170 | per_cpu(load_balance_mask, i) = (cpumask_var_t)kzalloc_node( | |
7171 | cpumask_size(), GFP_KERNEL, cpu_to_node(i)); | |
434d53b0 | 7172 | } |
b74e6278 | 7173 | #endif /* CONFIG_CPUMASK_OFFSTACK */ |
dd41f596 | 7174 | |
332ac17e DF |
7175 | init_rt_bandwidth(&def_rt_bandwidth, |
7176 | global_rt_period(), global_rt_runtime()); | |
7177 | init_dl_bandwidth(&def_dl_bandwidth, | |
1724813d | 7178 | global_rt_period(), global_rt_runtime()); |
332ac17e | 7179 | |
57d885fe GH |
7180 | #ifdef CONFIG_SMP |
7181 | init_defrootdomain(); | |
7182 | #endif | |
7183 | ||
d0b27fa7 | 7184 | #ifdef CONFIG_RT_GROUP_SCHED |
07e06b01 | 7185 | init_rt_bandwidth(&root_task_group.rt_bandwidth, |
d0b27fa7 | 7186 | global_rt_period(), global_rt_runtime()); |
6d6bc0ad | 7187 | #endif /* CONFIG_RT_GROUP_SCHED */ |
d0b27fa7 | 7188 | |
7c941438 | 7189 | #ifdef CONFIG_CGROUP_SCHED |
07e06b01 YZ |
7190 | list_add(&root_task_group.list, &task_groups); |
7191 | INIT_LIST_HEAD(&root_task_group.children); | |
f4d6f6c2 | 7192 | INIT_LIST_HEAD(&root_task_group.siblings); |
5091faa4 | 7193 | autogroup_init(&init_task); |
54c707e9 | 7194 | |
7c941438 | 7195 | #endif /* CONFIG_CGROUP_SCHED */ |
6f505b16 | 7196 | |
0a945022 | 7197 | for_each_possible_cpu(i) { |
70b97a7f | 7198 | struct rq *rq; |
1da177e4 LT |
7199 | |
7200 | rq = cpu_rq(i); | |
05fa785c | 7201 | raw_spin_lock_init(&rq->lock); |
7897986b | 7202 | rq->nr_running = 0; |
dce48a84 TG |
7203 | rq->calc_load_active = 0; |
7204 | rq->calc_load_update = jiffies + LOAD_FREQ; | |
acb5a9ba | 7205 | init_cfs_rq(&rq->cfs); |
6f505b16 | 7206 | init_rt_rq(&rq->rt, rq); |
aab03e05 | 7207 | init_dl_rq(&rq->dl, rq); |
dd41f596 | 7208 | #ifdef CONFIG_FAIR_GROUP_SCHED |
029632fb | 7209 | root_task_group.shares = ROOT_TASK_GROUP_LOAD; |
6f505b16 | 7210 | INIT_LIST_HEAD(&rq->leaf_cfs_rq_list); |
354d60c2 | 7211 | /* |
07e06b01 | 7212 | * How much cpu bandwidth does root_task_group get? |
354d60c2 DG |
7213 | * |
7214 | * In case of task-groups formed thr' the cgroup filesystem, it | |
7215 | * gets 100% of the cpu resources in the system. This overall | |
7216 | * system cpu resource is divided among the tasks of | |
07e06b01 | 7217 | * root_task_group and its child task-groups in a fair manner, |
354d60c2 DG |
7218 | * based on each entity's (task or task-group's) weight |
7219 | * (se->load.weight). | |
7220 | * | |
07e06b01 | 7221 | * In other words, if root_task_group has 10 tasks of weight |
354d60c2 DG |
7222 | * 1024) and two child groups A0 and A1 (of weight 1024 each), |
7223 | * then A0's share of the cpu resource is: | |
7224 | * | |
0d905bca | 7225 | * A0's bandwidth = 1024 / (10*1024 + 1024 + 1024) = 8.33% |
354d60c2 | 7226 | * |
07e06b01 YZ |
7227 | * We achieve this by letting root_task_group's tasks sit |
7228 | * directly in rq->cfs (i.e root_task_group->se[] = NULL). | |
354d60c2 | 7229 | */ |
ab84d31e | 7230 | init_cfs_bandwidth(&root_task_group.cfs_bandwidth); |
07e06b01 | 7231 | init_tg_cfs_entry(&root_task_group, &rq->cfs, NULL, i, NULL); |
354d60c2 DG |
7232 | #endif /* CONFIG_FAIR_GROUP_SCHED */ |
7233 | ||
7234 | rq->rt.rt_runtime = def_rt_bandwidth.rt_runtime; | |
052f1dc7 | 7235 | #ifdef CONFIG_RT_GROUP_SCHED |
07e06b01 | 7236 | init_tg_rt_entry(&root_task_group, &rq->rt, NULL, i, NULL); |
dd41f596 | 7237 | #endif |
1da177e4 | 7238 | |
dd41f596 IM |
7239 | for (j = 0; j < CPU_LOAD_IDX_MAX; j++) |
7240 | rq->cpu_load[j] = 0; | |
fdf3e95d VP |
7241 | |
7242 | rq->last_load_update_tick = jiffies; | |
7243 | ||
1da177e4 | 7244 | #ifdef CONFIG_SMP |
41c7ce9a | 7245 | rq->sd = NULL; |
57d885fe | 7246 | rq->rd = NULL; |
ca8ce3d0 | 7247 | rq->cpu_capacity = SCHED_CAPACITY_SCALE; |
3f029d3c | 7248 | rq->post_schedule = 0; |
1da177e4 | 7249 | rq->active_balance = 0; |
dd41f596 | 7250 | rq->next_balance = jiffies; |
1da177e4 | 7251 | rq->push_cpu = 0; |
0a2966b4 | 7252 | rq->cpu = i; |
1f11eb6a | 7253 | rq->online = 0; |
eae0c9df MG |
7254 | rq->idle_stamp = 0; |
7255 | rq->avg_idle = 2*sysctl_sched_migration_cost; | |
9bd721c5 | 7256 | rq->max_idle_balance_cost = sysctl_sched_migration_cost; |
367456c7 PZ |
7257 | |
7258 | INIT_LIST_HEAD(&rq->cfs_tasks); | |
7259 | ||
dc938520 | 7260 | rq_attach_root(rq, &def_root_domain); |
3451d024 | 7261 | #ifdef CONFIG_NO_HZ_COMMON |
1c792db7 | 7262 | rq->nohz_flags = 0; |
83cd4fe2 | 7263 | #endif |
265f22a9 FW |
7264 | #ifdef CONFIG_NO_HZ_FULL |
7265 | rq->last_sched_tick = 0; | |
7266 | #endif | |
1da177e4 | 7267 | #endif |
8f4d37ec | 7268 | init_rq_hrtick(rq); |
1da177e4 | 7269 | atomic_set(&rq->nr_iowait, 0); |
1da177e4 LT |
7270 | } |
7271 | ||
2dd73a4f | 7272 | set_load_weight(&init_task); |
b50f60ce | 7273 | |
e107be36 AK |
7274 | #ifdef CONFIG_PREEMPT_NOTIFIERS |
7275 | INIT_HLIST_HEAD(&init_task.preempt_notifiers); | |
7276 | #endif | |
7277 | ||
1da177e4 LT |
7278 | /* |
7279 | * The boot idle thread does lazy MMU switching as well: | |
7280 | */ | |
7281 | atomic_inc(&init_mm.mm_count); | |
7282 | enter_lazy_tlb(&init_mm, current); | |
7283 | ||
1b537c7d YD |
7284 | /* |
7285 | * During early bootup we pretend to be a normal task: | |
7286 | */ | |
7287 | current->sched_class = &fair_sched_class; | |
7288 | ||
1da177e4 LT |
7289 | /* |
7290 | * Make us the idle thread. Technically, schedule() should not be | |
7291 | * called from this thread, however somewhere below it might be, | |
7292 | * but because we are the idle thread, we just pick up running again | |
7293 | * when this runqueue becomes "idle". | |
7294 | */ | |
7295 | init_idle(current, smp_processor_id()); | |
dce48a84 TG |
7296 | |
7297 | calc_load_update = jiffies + LOAD_FREQ; | |
7298 | ||
bf4d83f6 | 7299 | #ifdef CONFIG_SMP |
4cb98839 | 7300 | zalloc_cpumask_var(&sched_domains_tmpmask, GFP_NOWAIT); |
bdddd296 RR |
7301 | /* May be allocated at isolcpus cmdline parse time */ |
7302 | if (cpu_isolated_map == NULL) | |
7303 | zalloc_cpumask_var(&cpu_isolated_map, GFP_NOWAIT); | |
29d5e047 | 7304 | idle_thread_set_boot_cpu(); |
a803f026 | 7305 | set_cpu_rq_start_time(); |
029632fb PZ |
7306 | #endif |
7307 | init_sched_fair_class(); | |
6a7b3dc3 | 7308 | |
6892b75e | 7309 | scheduler_running = 1; |
1da177e4 LT |
7310 | } |
7311 | ||
d902db1e | 7312 | #ifdef CONFIG_DEBUG_ATOMIC_SLEEP |
e4aafea2 FW |
7313 | static inline int preempt_count_equals(int preempt_offset) |
7314 | { | |
234da7bc | 7315 | int nested = (preempt_count() & ~PREEMPT_ACTIVE) + rcu_preempt_depth(); |
e4aafea2 | 7316 | |
4ba8216c | 7317 | return (nested == preempt_offset); |
e4aafea2 FW |
7318 | } |
7319 | ||
d894837f | 7320 | void __might_sleep(const char *file, int line, int preempt_offset) |
1da177e4 | 7321 | { |
8eb23b9f PZ |
7322 | /* |
7323 | * Blocking primitives will set (and therefore destroy) current->state, | |
7324 | * since we will exit with TASK_RUNNING make sure we enter with it, | |
7325 | * otherwise we will destroy state. | |
7326 | */ | |
e7097e8b | 7327 | if (WARN_ONCE(current->state != TASK_RUNNING, |
8eb23b9f PZ |
7328 | "do not call blocking ops when !TASK_RUNNING; " |
7329 | "state=%lx set at [<%p>] %pS\n", | |
7330 | current->state, | |
7331 | (void *)current->task_state_change, | |
7332 | (void *)current->task_state_change)) | |
7333 | __set_current_state(TASK_RUNNING); | |
7334 | ||
3427445a PZ |
7335 | ___might_sleep(file, line, preempt_offset); |
7336 | } | |
7337 | EXPORT_SYMBOL(__might_sleep); | |
7338 | ||
7339 | void ___might_sleep(const char *file, int line, int preempt_offset) | |
1da177e4 | 7340 | { |
1da177e4 LT |
7341 | static unsigned long prev_jiffy; /* ratelimiting */ |
7342 | ||
b3fbab05 | 7343 | rcu_sleep_check(); /* WARN_ON_ONCE() by default, no rate limit reqd. */ |
db273be2 TG |
7344 | if ((preempt_count_equals(preempt_offset) && !irqs_disabled() && |
7345 | !is_idle_task(current)) || | |
e4aafea2 | 7346 | system_state != SYSTEM_RUNNING || oops_in_progress) |
aef745fc IM |
7347 | return; |
7348 | if (time_before(jiffies, prev_jiffy + HZ) && prev_jiffy) | |
7349 | return; | |
7350 | prev_jiffy = jiffies; | |
7351 | ||
3df0fc5b PZ |
7352 | printk(KERN_ERR |
7353 | "BUG: sleeping function called from invalid context at %s:%d\n", | |
7354 | file, line); | |
7355 | printk(KERN_ERR | |
7356 | "in_atomic(): %d, irqs_disabled(): %d, pid: %d, name: %s\n", | |
7357 | in_atomic(), irqs_disabled(), | |
7358 | current->pid, current->comm); | |
aef745fc | 7359 | |
a8b686b3 ES |
7360 | if (task_stack_end_corrupted(current)) |
7361 | printk(KERN_EMERG "Thread overran stack, or stack corrupted\n"); | |
7362 | ||
aef745fc IM |
7363 | debug_show_held_locks(current); |
7364 | if (irqs_disabled()) | |
7365 | print_irqtrace_events(current); | |
8f47b187 TG |
7366 | #ifdef CONFIG_DEBUG_PREEMPT |
7367 | if (!preempt_count_equals(preempt_offset)) { | |
7368 | pr_err("Preemption disabled at:"); | |
7369 | print_ip_sym(current->preempt_disable_ip); | |
7370 | pr_cont("\n"); | |
7371 | } | |
7372 | #endif | |
aef745fc | 7373 | dump_stack(); |
1da177e4 | 7374 | } |
3427445a | 7375 | EXPORT_SYMBOL(___might_sleep); |
1da177e4 LT |
7376 | #endif |
7377 | ||
7378 | #ifdef CONFIG_MAGIC_SYSRQ | |
3a5e4dc1 AK |
7379 | static void normalize_task(struct rq *rq, struct task_struct *p) |
7380 | { | |
da7a735e | 7381 | const struct sched_class *prev_class = p->sched_class; |
d50dde5a DF |
7382 | struct sched_attr attr = { |
7383 | .sched_policy = SCHED_NORMAL, | |
7384 | }; | |
da7a735e | 7385 | int old_prio = p->prio; |
da0c1e65 | 7386 | int queued; |
3e51f33f | 7387 | |
da0c1e65 KT |
7388 | queued = task_on_rq_queued(p); |
7389 | if (queued) | |
4ca9b72b | 7390 | dequeue_task(rq, p, 0); |
d50dde5a | 7391 | __setscheduler(rq, p, &attr); |
da0c1e65 | 7392 | if (queued) { |
4ca9b72b | 7393 | enqueue_task(rq, p, 0); |
8875125e | 7394 | resched_curr(rq); |
3a5e4dc1 | 7395 | } |
da7a735e PZ |
7396 | |
7397 | check_class_changed(rq, p, prev_class, old_prio); | |
3a5e4dc1 AK |
7398 | } |
7399 | ||
1da177e4 LT |
7400 | void normalize_rt_tasks(void) |
7401 | { | |
a0f98a1c | 7402 | struct task_struct *g, *p; |
1da177e4 | 7403 | unsigned long flags; |
70b97a7f | 7404 | struct rq *rq; |
1da177e4 | 7405 | |
3472eaa1 | 7406 | read_lock(&tasklist_lock); |
5d07f420 | 7407 | for_each_process_thread(g, p) { |
178be793 IM |
7408 | /* |
7409 | * Only normalize user tasks: | |
7410 | */ | |
3472eaa1 | 7411 | if (p->flags & PF_KTHREAD) |
178be793 IM |
7412 | continue; |
7413 | ||
6cfb0d5d | 7414 | p->se.exec_start = 0; |
6cfb0d5d | 7415 | #ifdef CONFIG_SCHEDSTATS |
41acab88 LDM |
7416 | p->se.statistics.wait_start = 0; |
7417 | p->se.statistics.sleep_start = 0; | |
7418 | p->se.statistics.block_start = 0; | |
6cfb0d5d | 7419 | #endif |
dd41f596 | 7420 | |
aab03e05 | 7421 | if (!dl_task(p) && !rt_task(p)) { |
dd41f596 IM |
7422 | /* |
7423 | * Renice negative nice level userspace | |
7424 | * tasks back to 0: | |
7425 | */ | |
3472eaa1 | 7426 | if (task_nice(p) < 0) |
dd41f596 | 7427 | set_user_nice(p, 0); |
1da177e4 | 7428 | continue; |
dd41f596 | 7429 | } |
1da177e4 | 7430 | |
3472eaa1 | 7431 | rq = task_rq_lock(p, &flags); |
178be793 | 7432 | normalize_task(rq, p); |
3472eaa1 | 7433 | task_rq_unlock(rq, p, &flags); |
5d07f420 | 7434 | } |
3472eaa1 | 7435 | read_unlock(&tasklist_lock); |
1da177e4 LT |
7436 | } |
7437 | ||
7438 | #endif /* CONFIG_MAGIC_SYSRQ */ | |
1df5c10a | 7439 | |
67fc4e0c | 7440 | #if defined(CONFIG_IA64) || defined(CONFIG_KGDB_KDB) |
1df5c10a | 7441 | /* |
67fc4e0c | 7442 | * These functions are only useful for the IA64 MCA handling, or kdb. |
1df5c10a LT |
7443 | * |
7444 | * They can only be called when the whole system has been | |
7445 | * stopped - every CPU needs to be quiescent, and no scheduling | |
7446 | * activity can take place. Using them for anything else would | |
7447 | * be a serious bug, and as a result, they aren't even visible | |
7448 | * under any other configuration. | |
7449 | */ | |
7450 | ||
7451 | /** | |
7452 | * curr_task - return the current task for a given cpu. | |
7453 | * @cpu: the processor in question. | |
7454 | * | |
7455 | * ONLY VALID WHEN THE WHOLE SYSTEM IS STOPPED! | |
e69f6186 YB |
7456 | * |
7457 | * Return: The current task for @cpu. | |
1df5c10a | 7458 | */ |
36c8b586 | 7459 | struct task_struct *curr_task(int cpu) |
1df5c10a LT |
7460 | { |
7461 | return cpu_curr(cpu); | |
7462 | } | |
7463 | ||
67fc4e0c JW |
7464 | #endif /* defined(CONFIG_IA64) || defined(CONFIG_KGDB_KDB) */ |
7465 | ||
7466 | #ifdef CONFIG_IA64 | |
1df5c10a LT |
7467 | /** |
7468 | * set_curr_task - set the current task for a given cpu. | |
7469 | * @cpu: the processor in question. | |
7470 | * @p: the task pointer to set. | |
7471 | * | |
7472 | * Description: This function must only be used when non-maskable interrupts | |
41a2d6cf IM |
7473 | * are serviced on a separate stack. It allows the architecture to switch the |
7474 | * notion of the current task on a cpu in a non-blocking manner. This function | |
1df5c10a LT |
7475 | * must be called with all CPU's synchronized, and interrupts disabled, the |
7476 | * and caller must save the original value of the current task (see | |
7477 | * curr_task() above) and restore that value before reenabling interrupts and | |
7478 | * re-starting the system. | |
7479 | * | |
7480 | * ONLY VALID WHEN THE WHOLE SYSTEM IS STOPPED! | |
7481 | */ | |
36c8b586 | 7482 | void set_curr_task(int cpu, struct task_struct *p) |
1df5c10a LT |
7483 | { |
7484 | cpu_curr(cpu) = p; | |
7485 | } | |
7486 | ||
7487 | #endif | |
29f59db3 | 7488 | |
7c941438 | 7489 | #ifdef CONFIG_CGROUP_SCHED |
029632fb PZ |
7490 | /* task_group_lock serializes the addition/removal of task groups */ |
7491 | static DEFINE_SPINLOCK(task_group_lock); | |
7492 | ||
bccbe08a PZ |
7493 | static void free_sched_group(struct task_group *tg) |
7494 | { | |
7495 | free_fair_sched_group(tg); | |
7496 | free_rt_sched_group(tg); | |
e9aa1dd1 | 7497 | autogroup_free(tg); |
bccbe08a PZ |
7498 | kfree(tg); |
7499 | } | |
7500 | ||
7501 | /* allocate runqueue etc for a new task group */ | |
ec7dc8ac | 7502 | struct task_group *sched_create_group(struct task_group *parent) |
bccbe08a PZ |
7503 | { |
7504 | struct task_group *tg; | |
bccbe08a PZ |
7505 | |
7506 | tg = kzalloc(sizeof(*tg), GFP_KERNEL); | |
7507 | if (!tg) | |
7508 | return ERR_PTR(-ENOMEM); | |
7509 | ||
ec7dc8ac | 7510 | if (!alloc_fair_sched_group(tg, parent)) |
bccbe08a PZ |
7511 | goto err; |
7512 | ||
ec7dc8ac | 7513 | if (!alloc_rt_sched_group(tg, parent)) |
bccbe08a PZ |
7514 | goto err; |
7515 | ||
ace783b9 LZ |
7516 | return tg; |
7517 | ||
7518 | err: | |
7519 | free_sched_group(tg); | |
7520 | return ERR_PTR(-ENOMEM); | |
7521 | } | |
7522 | ||
7523 | void sched_online_group(struct task_group *tg, struct task_group *parent) | |
7524 | { | |
7525 | unsigned long flags; | |
7526 | ||
8ed36996 | 7527 | spin_lock_irqsave(&task_group_lock, flags); |
6f505b16 | 7528 | list_add_rcu(&tg->list, &task_groups); |
f473aa5e PZ |
7529 | |
7530 | WARN_ON(!parent); /* root should already exist */ | |
7531 | ||
7532 | tg->parent = parent; | |
f473aa5e | 7533 | INIT_LIST_HEAD(&tg->children); |
09f2724a | 7534 | list_add_rcu(&tg->siblings, &parent->children); |
8ed36996 | 7535 | spin_unlock_irqrestore(&task_group_lock, flags); |
29f59db3 SV |
7536 | } |
7537 | ||
9b5b7751 | 7538 | /* rcu callback to free various structures associated with a task group */ |
6f505b16 | 7539 | static void free_sched_group_rcu(struct rcu_head *rhp) |
29f59db3 | 7540 | { |
29f59db3 | 7541 | /* now it should be safe to free those cfs_rqs */ |
6f505b16 | 7542 | free_sched_group(container_of(rhp, struct task_group, rcu)); |
29f59db3 SV |
7543 | } |
7544 | ||
9b5b7751 | 7545 | /* Destroy runqueue etc associated with a task group */ |
4cf86d77 | 7546 | void sched_destroy_group(struct task_group *tg) |
ace783b9 LZ |
7547 | { |
7548 | /* wait for possible concurrent references to cfs_rqs complete */ | |
7549 | call_rcu(&tg->rcu, free_sched_group_rcu); | |
7550 | } | |
7551 | ||
7552 | void sched_offline_group(struct task_group *tg) | |
29f59db3 | 7553 | { |
8ed36996 | 7554 | unsigned long flags; |
9b5b7751 | 7555 | int i; |
29f59db3 | 7556 | |
3d4b47b4 PZ |
7557 | /* end participation in shares distribution */ |
7558 | for_each_possible_cpu(i) | |
bccbe08a | 7559 | unregister_fair_sched_group(tg, i); |
3d4b47b4 PZ |
7560 | |
7561 | spin_lock_irqsave(&task_group_lock, flags); | |
6f505b16 | 7562 | list_del_rcu(&tg->list); |
f473aa5e | 7563 | list_del_rcu(&tg->siblings); |
8ed36996 | 7564 | spin_unlock_irqrestore(&task_group_lock, flags); |
29f59db3 SV |
7565 | } |
7566 | ||
9b5b7751 | 7567 | /* change task's runqueue when it moves between groups. |
3a252015 IM |
7568 | * The caller of this function should have put the task in its new group |
7569 | * by now. This function just updates tsk->se.cfs_rq and tsk->se.parent to | |
7570 | * reflect its new group. | |
9b5b7751 SV |
7571 | */ |
7572 | void sched_move_task(struct task_struct *tsk) | |
29f59db3 | 7573 | { |
8323f26c | 7574 | struct task_group *tg; |
da0c1e65 | 7575 | int queued, running; |
29f59db3 SV |
7576 | unsigned long flags; |
7577 | struct rq *rq; | |
7578 | ||
7579 | rq = task_rq_lock(tsk, &flags); | |
7580 | ||
051a1d1a | 7581 | running = task_current(rq, tsk); |
da0c1e65 | 7582 | queued = task_on_rq_queued(tsk); |
29f59db3 | 7583 | |
da0c1e65 | 7584 | if (queued) |
29f59db3 | 7585 | dequeue_task(rq, tsk, 0); |
0e1f3483 | 7586 | if (unlikely(running)) |
f3cd1c4e | 7587 | put_prev_task(rq, tsk); |
29f59db3 | 7588 | |
f7b8a47d KT |
7589 | /* |
7590 | * All callers are synchronized by task_rq_lock(); we do not use RCU | |
7591 | * which is pointless here. Thus, we pass "true" to task_css_check() | |
7592 | * to prevent lockdep warnings. | |
7593 | */ | |
7594 | tg = container_of(task_css_check(tsk, cpu_cgrp_id, true), | |
8323f26c PZ |
7595 | struct task_group, css); |
7596 | tg = autogroup_task_group(tsk, tg); | |
7597 | tsk->sched_task_group = tg; | |
7598 | ||
810b3817 | 7599 | #ifdef CONFIG_FAIR_GROUP_SCHED |
b2b5ce02 | 7600 | if (tsk->sched_class->task_move_group) |
da0c1e65 | 7601 | tsk->sched_class->task_move_group(tsk, queued); |
b2b5ce02 | 7602 | else |
810b3817 | 7603 | #endif |
b2b5ce02 | 7604 | set_task_rq(tsk, task_cpu(tsk)); |
810b3817 | 7605 | |
0e1f3483 HS |
7606 | if (unlikely(running)) |
7607 | tsk->sched_class->set_curr_task(rq); | |
da0c1e65 | 7608 | if (queued) |
371fd7e7 | 7609 | enqueue_task(rq, tsk, 0); |
29f59db3 | 7610 | |
0122ec5b | 7611 | task_rq_unlock(rq, tsk, &flags); |
29f59db3 | 7612 | } |
7c941438 | 7613 | #endif /* CONFIG_CGROUP_SCHED */ |
29f59db3 | 7614 | |
a790de99 PT |
7615 | #ifdef CONFIG_RT_GROUP_SCHED |
7616 | /* | |
7617 | * Ensure that the real time constraints are schedulable. | |
7618 | */ | |
7619 | static DEFINE_MUTEX(rt_constraints_mutex); | |
9f0c1e56 | 7620 | |
9a7e0b18 PZ |
7621 | /* Must be called with tasklist_lock held */ |
7622 | static inline int tg_has_rt_tasks(struct task_group *tg) | |
b40b2e8e | 7623 | { |
9a7e0b18 | 7624 | struct task_struct *g, *p; |
b40b2e8e | 7625 | |
5d07f420 | 7626 | for_each_process_thread(g, p) { |
8651c658 | 7627 | if (rt_task(p) && task_group(p) == tg) |
9a7e0b18 | 7628 | return 1; |
5d07f420 | 7629 | } |
b40b2e8e | 7630 | |
9a7e0b18 PZ |
7631 | return 0; |
7632 | } | |
b40b2e8e | 7633 | |
9a7e0b18 PZ |
7634 | struct rt_schedulable_data { |
7635 | struct task_group *tg; | |
7636 | u64 rt_period; | |
7637 | u64 rt_runtime; | |
7638 | }; | |
b40b2e8e | 7639 | |
a790de99 | 7640 | static int tg_rt_schedulable(struct task_group *tg, void *data) |
9a7e0b18 PZ |
7641 | { |
7642 | struct rt_schedulable_data *d = data; | |
7643 | struct task_group *child; | |
7644 | unsigned long total, sum = 0; | |
7645 | u64 period, runtime; | |
b40b2e8e | 7646 | |
9a7e0b18 PZ |
7647 | period = ktime_to_ns(tg->rt_bandwidth.rt_period); |
7648 | runtime = tg->rt_bandwidth.rt_runtime; | |
b40b2e8e | 7649 | |
9a7e0b18 PZ |
7650 | if (tg == d->tg) { |
7651 | period = d->rt_period; | |
7652 | runtime = d->rt_runtime; | |
b40b2e8e | 7653 | } |
b40b2e8e | 7654 | |
4653f803 PZ |
7655 | /* |
7656 | * Cannot have more runtime than the period. | |
7657 | */ | |
7658 | if (runtime > period && runtime != RUNTIME_INF) | |
7659 | return -EINVAL; | |
6f505b16 | 7660 | |
4653f803 PZ |
7661 | /* |
7662 | * Ensure we don't starve existing RT tasks. | |
7663 | */ | |
9a7e0b18 PZ |
7664 | if (rt_bandwidth_enabled() && !runtime && tg_has_rt_tasks(tg)) |
7665 | return -EBUSY; | |
6f505b16 | 7666 | |
9a7e0b18 | 7667 | total = to_ratio(period, runtime); |
6f505b16 | 7668 | |
4653f803 PZ |
7669 | /* |
7670 | * Nobody can have more than the global setting allows. | |
7671 | */ | |
7672 | if (total > to_ratio(global_rt_period(), global_rt_runtime())) | |
7673 | return -EINVAL; | |
6f505b16 | 7674 | |
4653f803 PZ |
7675 | /* |
7676 | * The sum of our children's runtime should not exceed our own. | |
7677 | */ | |
9a7e0b18 PZ |
7678 | list_for_each_entry_rcu(child, &tg->children, siblings) { |
7679 | period = ktime_to_ns(child->rt_bandwidth.rt_period); | |
7680 | runtime = child->rt_bandwidth.rt_runtime; | |
6f505b16 | 7681 | |
9a7e0b18 PZ |
7682 | if (child == d->tg) { |
7683 | period = d->rt_period; | |
7684 | runtime = d->rt_runtime; | |
7685 | } | |
6f505b16 | 7686 | |
9a7e0b18 | 7687 | sum += to_ratio(period, runtime); |
9f0c1e56 | 7688 | } |
6f505b16 | 7689 | |
9a7e0b18 PZ |
7690 | if (sum > total) |
7691 | return -EINVAL; | |
7692 | ||
7693 | return 0; | |
6f505b16 PZ |
7694 | } |
7695 | ||
9a7e0b18 | 7696 | static int __rt_schedulable(struct task_group *tg, u64 period, u64 runtime) |
521f1a24 | 7697 | { |
8277434e PT |
7698 | int ret; |
7699 | ||
9a7e0b18 PZ |
7700 | struct rt_schedulable_data data = { |
7701 | .tg = tg, | |
7702 | .rt_period = period, | |
7703 | .rt_runtime = runtime, | |
7704 | }; | |
7705 | ||
8277434e PT |
7706 | rcu_read_lock(); |
7707 | ret = walk_tg_tree(tg_rt_schedulable, tg_nop, &data); | |
7708 | rcu_read_unlock(); | |
7709 | ||
7710 | return ret; | |
521f1a24 DG |
7711 | } |
7712 | ||
ab84d31e | 7713 | static int tg_set_rt_bandwidth(struct task_group *tg, |
d0b27fa7 | 7714 | u64 rt_period, u64 rt_runtime) |
6f505b16 | 7715 | { |
ac086bc2 | 7716 | int i, err = 0; |
9f0c1e56 | 7717 | |
9f0c1e56 | 7718 | mutex_lock(&rt_constraints_mutex); |
521f1a24 | 7719 | read_lock(&tasklist_lock); |
9a7e0b18 PZ |
7720 | err = __rt_schedulable(tg, rt_period, rt_runtime); |
7721 | if (err) | |
9f0c1e56 | 7722 | goto unlock; |
ac086bc2 | 7723 | |
0986b11b | 7724 | raw_spin_lock_irq(&tg->rt_bandwidth.rt_runtime_lock); |
d0b27fa7 PZ |
7725 | tg->rt_bandwidth.rt_period = ns_to_ktime(rt_period); |
7726 | tg->rt_bandwidth.rt_runtime = rt_runtime; | |
ac086bc2 PZ |
7727 | |
7728 | for_each_possible_cpu(i) { | |
7729 | struct rt_rq *rt_rq = tg->rt_rq[i]; | |
7730 | ||
0986b11b | 7731 | raw_spin_lock(&rt_rq->rt_runtime_lock); |
ac086bc2 | 7732 | rt_rq->rt_runtime = rt_runtime; |
0986b11b | 7733 | raw_spin_unlock(&rt_rq->rt_runtime_lock); |
ac086bc2 | 7734 | } |
0986b11b | 7735 | raw_spin_unlock_irq(&tg->rt_bandwidth.rt_runtime_lock); |
49246274 | 7736 | unlock: |
521f1a24 | 7737 | read_unlock(&tasklist_lock); |
9f0c1e56 PZ |
7738 | mutex_unlock(&rt_constraints_mutex); |
7739 | ||
7740 | return err; | |
6f505b16 PZ |
7741 | } |
7742 | ||
25cc7da7 | 7743 | static int sched_group_set_rt_runtime(struct task_group *tg, long rt_runtime_us) |
d0b27fa7 PZ |
7744 | { |
7745 | u64 rt_runtime, rt_period; | |
7746 | ||
7747 | rt_period = ktime_to_ns(tg->rt_bandwidth.rt_period); | |
7748 | rt_runtime = (u64)rt_runtime_us * NSEC_PER_USEC; | |
7749 | if (rt_runtime_us < 0) | |
7750 | rt_runtime = RUNTIME_INF; | |
7751 | ||
ab84d31e | 7752 | return tg_set_rt_bandwidth(tg, rt_period, rt_runtime); |
d0b27fa7 PZ |
7753 | } |
7754 | ||
25cc7da7 | 7755 | static long sched_group_rt_runtime(struct task_group *tg) |
9f0c1e56 PZ |
7756 | { |
7757 | u64 rt_runtime_us; | |
7758 | ||
d0b27fa7 | 7759 | if (tg->rt_bandwidth.rt_runtime == RUNTIME_INF) |
9f0c1e56 PZ |
7760 | return -1; |
7761 | ||
d0b27fa7 | 7762 | rt_runtime_us = tg->rt_bandwidth.rt_runtime; |
9f0c1e56 PZ |
7763 | do_div(rt_runtime_us, NSEC_PER_USEC); |
7764 | return rt_runtime_us; | |
7765 | } | |
d0b27fa7 | 7766 | |
25cc7da7 | 7767 | static int sched_group_set_rt_period(struct task_group *tg, long rt_period_us) |
d0b27fa7 PZ |
7768 | { |
7769 | u64 rt_runtime, rt_period; | |
7770 | ||
7771 | rt_period = (u64)rt_period_us * NSEC_PER_USEC; | |
7772 | rt_runtime = tg->rt_bandwidth.rt_runtime; | |
7773 | ||
619b0488 R |
7774 | if (rt_period == 0) |
7775 | return -EINVAL; | |
7776 | ||
ab84d31e | 7777 | return tg_set_rt_bandwidth(tg, rt_period, rt_runtime); |
d0b27fa7 PZ |
7778 | } |
7779 | ||
25cc7da7 | 7780 | static long sched_group_rt_period(struct task_group *tg) |
d0b27fa7 PZ |
7781 | { |
7782 | u64 rt_period_us; | |
7783 | ||
7784 | rt_period_us = ktime_to_ns(tg->rt_bandwidth.rt_period); | |
7785 | do_div(rt_period_us, NSEC_PER_USEC); | |
7786 | return rt_period_us; | |
7787 | } | |
332ac17e | 7788 | #endif /* CONFIG_RT_GROUP_SCHED */ |
d0b27fa7 | 7789 | |
332ac17e | 7790 | #ifdef CONFIG_RT_GROUP_SCHED |
d0b27fa7 PZ |
7791 | static int sched_rt_global_constraints(void) |
7792 | { | |
7793 | int ret = 0; | |
7794 | ||
7795 | mutex_lock(&rt_constraints_mutex); | |
9a7e0b18 | 7796 | read_lock(&tasklist_lock); |
4653f803 | 7797 | ret = __rt_schedulable(NULL, 0, 0); |
9a7e0b18 | 7798 | read_unlock(&tasklist_lock); |
d0b27fa7 PZ |
7799 | mutex_unlock(&rt_constraints_mutex); |
7800 | ||
7801 | return ret; | |
7802 | } | |
54e99124 | 7803 | |
25cc7da7 | 7804 | static int sched_rt_can_attach(struct task_group *tg, struct task_struct *tsk) |
54e99124 DG |
7805 | { |
7806 | /* Don't accept realtime tasks when there is no way for them to run */ | |
7807 | if (rt_task(tsk) && tg->rt_bandwidth.rt_runtime == 0) | |
7808 | return 0; | |
7809 | ||
7810 | return 1; | |
7811 | } | |
7812 | ||
6d6bc0ad | 7813 | #else /* !CONFIG_RT_GROUP_SCHED */ |
d0b27fa7 PZ |
7814 | static int sched_rt_global_constraints(void) |
7815 | { | |
ac086bc2 | 7816 | unsigned long flags; |
332ac17e | 7817 | int i, ret = 0; |
ec5d4989 | 7818 | |
0986b11b | 7819 | raw_spin_lock_irqsave(&def_rt_bandwidth.rt_runtime_lock, flags); |
ac086bc2 PZ |
7820 | for_each_possible_cpu(i) { |
7821 | struct rt_rq *rt_rq = &cpu_rq(i)->rt; | |
7822 | ||
0986b11b | 7823 | raw_spin_lock(&rt_rq->rt_runtime_lock); |
ac086bc2 | 7824 | rt_rq->rt_runtime = global_rt_runtime(); |
0986b11b | 7825 | raw_spin_unlock(&rt_rq->rt_runtime_lock); |
ac086bc2 | 7826 | } |
0986b11b | 7827 | raw_spin_unlock_irqrestore(&def_rt_bandwidth.rt_runtime_lock, flags); |
ac086bc2 | 7828 | |
332ac17e | 7829 | return ret; |
d0b27fa7 | 7830 | } |
6d6bc0ad | 7831 | #endif /* CONFIG_RT_GROUP_SCHED */ |
d0b27fa7 | 7832 | |
332ac17e DF |
7833 | static int sched_dl_global_constraints(void) |
7834 | { | |
1724813d PZ |
7835 | u64 runtime = global_rt_runtime(); |
7836 | u64 period = global_rt_period(); | |
332ac17e | 7837 | u64 new_bw = to_ratio(period, runtime); |
f10e00f4 | 7838 | struct dl_bw *dl_b; |
1724813d | 7839 | int cpu, ret = 0; |
49516342 | 7840 | unsigned long flags; |
332ac17e DF |
7841 | |
7842 | /* | |
7843 | * Here we want to check the bandwidth not being set to some | |
7844 | * value smaller than the currently allocated bandwidth in | |
7845 | * any of the root_domains. | |
7846 | * | |
7847 | * FIXME: Cycling on all the CPUs is overdoing, but simpler than | |
7848 | * cycling on root_domains... Discussion on different/better | |
7849 | * solutions is welcome! | |
7850 | */ | |
1724813d | 7851 | for_each_possible_cpu(cpu) { |
f10e00f4 KT |
7852 | rcu_read_lock_sched(); |
7853 | dl_b = dl_bw_of(cpu); | |
332ac17e | 7854 | |
49516342 | 7855 | raw_spin_lock_irqsave(&dl_b->lock, flags); |
1724813d PZ |
7856 | if (new_bw < dl_b->total_bw) |
7857 | ret = -EBUSY; | |
49516342 | 7858 | raw_spin_unlock_irqrestore(&dl_b->lock, flags); |
1724813d | 7859 | |
f10e00f4 KT |
7860 | rcu_read_unlock_sched(); |
7861 | ||
1724813d PZ |
7862 | if (ret) |
7863 | break; | |
332ac17e DF |
7864 | } |
7865 | ||
1724813d | 7866 | return ret; |
332ac17e DF |
7867 | } |
7868 | ||
1724813d | 7869 | static void sched_dl_do_global(void) |
ce0dbbbb | 7870 | { |
1724813d | 7871 | u64 new_bw = -1; |
f10e00f4 | 7872 | struct dl_bw *dl_b; |
1724813d | 7873 | int cpu; |
49516342 | 7874 | unsigned long flags; |
ce0dbbbb | 7875 | |
1724813d PZ |
7876 | def_dl_bandwidth.dl_period = global_rt_period(); |
7877 | def_dl_bandwidth.dl_runtime = global_rt_runtime(); | |
7878 | ||
7879 | if (global_rt_runtime() != RUNTIME_INF) | |
7880 | new_bw = to_ratio(global_rt_period(), global_rt_runtime()); | |
7881 | ||
7882 | /* | |
7883 | * FIXME: As above... | |
7884 | */ | |
7885 | for_each_possible_cpu(cpu) { | |
f10e00f4 KT |
7886 | rcu_read_lock_sched(); |
7887 | dl_b = dl_bw_of(cpu); | |
1724813d | 7888 | |
49516342 | 7889 | raw_spin_lock_irqsave(&dl_b->lock, flags); |
1724813d | 7890 | dl_b->bw = new_bw; |
49516342 | 7891 | raw_spin_unlock_irqrestore(&dl_b->lock, flags); |
f10e00f4 KT |
7892 | |
7893 | rcu_read_unlock_sched(); | |
ce0dbbbb | 7894 | } |
1724813d PZ |
7895 | } |
7896 | ||
7897 | static int sched_rt_global_validate(void) | |
7898 | { | |
7899 | if (sysctl_sched_rt_period <= 0) | |
7900 | return -EINVAL; | |
7901 | ||
e9e7cb38 JL |
7902 | if ((sysctl_sched_rt_runtime != RUNTIME_INF) && |
7903 | (sysctl_sched_rt_runtime > sysctl_sched_rt_period)) | |
1724813d PZ |
7904 | return -EINVAL; |
7905 | ||
7906 | return 0; | |
7907 | } | |
7908 | ||
7909 | static void sched_rt_do_global(void) | |
7910 | { | |
7911 | def_rt_bandwidth.rt_runtime = global_rt_runtime(); | |
7912 | def_rt_bandwidth.rt_period = ns_to_ktime(global_rt_period()); | |
ce0dbbbb CW |
7913 | } |
7914 | ||
d0b27fa7 | 7915 | int sched_rt_handler(struct ctl_table *table, int write, |
8d65af78 | 7916 | void __user *buffer, size_t *lenp, |
d0b27fa7 PZ |
7917 | loff_t *ppos) |
7918 | { | |
d0b27fa7 PZ |
7919 | int old_period, old_runtime; |
7920 | static DEFINE_MUTEX(mutex); | |
1724813d | 7921 | int ret; |
d0b27fa7 PZ |
7922 | |
7923 | mutex_lock(&mutex); | |
7924 | old_period = sysctl_sched_rt_period; | |
7925 | old_runtime = sysctl_sched_rt_runtime; | |
7926 | ||
8d65af78 | 7927 | ret = proc_dointvec(table, write, buffer, lenp, ppos); |
d0b27fa7 PZ |
7928 | |
7929 | if (!ret && write) { | |
1724813d PZ |
7930 | ret = sched_rt_global_validate(); |
7931 | if (ret) | |
7932 | goto undo; | |
7933 | ||
d0b27fa7 | 7934 | ret = sched_rt_global_constraints(); |
1724813d PZ |
7935 | if (ret) |
7936 | goto undo; | |
7937 | ||
7938 | ret = sched_dl_global_constraints(); | |
7939 | if (ret) | |
7940 | goto undo; | |
7941 | ||
7942 | sched_rt_do_global(); | |
7943 | sched_dl_do_global(); | |
7944 | } | |
7945 | if (0) { | |
7946 | undo: | |
7947 | sysctl_sched_rt_period = old_period; | |
7948 | sysctl_sched_rt_runtime = old_runtime; | |
d0b27fa7 PZ |
7949 | } |
7950 | mutex_unlock(&mutex); | |
7951 | ||
7952 | return ret; | |
7953 | } | |
68318b8e | 7954 | |
1724813d | 7955 | int sched_rr_handler(struct ctl_table *table, int write, |
332ac17e DF |
7956 | void __user *buffer, size_t *lenp, |
7957 | loff_t *ppos) | |
7958 | { | |
7959 | int ret; | |
332ac17e | 7960 | static DEFINE_MUTEX(mutex); |
332ac17e DF |
7961 | |
7962 | mutex_lock(&mutex); | |
332ac17e | 7963 | ret = proc_dointvec(table, write, buffer, lenp, ppos); |
1724813d PZ |
7964 | /* make sure that internally we keep jiffies */ |
7965 | /* also, writing zero resets timeslice to default */ | |
332ac17e | 7966 | if (!ret && write) { |
1724813d PZ |
7967 | sched_rr_timeslice = sched_rr_timeslice <= 0 ? |
7968 | RR_TIMESLICE : msecs_to_jiffies(sched_rr_timeslice); | |
332ac17e DF |
7969 | } |
7970 | mutex_unlock(&mutex); | |
332ac17e DF |
7971 | return ret; |
7972 | } | |
7973 | ||
052f1dc7 | 7974 | #ifdef CONFIG_CGROUP_SCHED |
68318b8e | 7975 | |
a7c6d554 | 7976 | static inline struct task_group *css_tg(struct cgroup_subsys_state *css) |
68318b8e | 7977 | { |
a7c6d554 | 7978 | return css ? container_of(css, struct task_group, css) : NULL; |
68318b8e SV |
7979 | } |
7980 | ||
eb95419b TH |
7981 | static struct cgroup_subsys_state * |
7982 | cpu_cgroup_css_alloc(struct cgroup_subsys_state *parent_css) | |
68318b8e | 7983 | { |
eb95419b TH |
7984 | struct task_group *parent = css_tg(parent_css); |
7985 | struct task_group *tg; | |
68318b8e | 7986 | |
eb95419b | 7987 | if (!parent) { |
68318b8e | 7988 | /* This is early initialization for the top cgroup */ |
07e06b01 | 7989 | return &root_task_group.css; |
68318b8e SV |
7990 | } |
7991 | ||
ec7dc8ac | 7992 | tg = sched_create_group(parent); |
68318b8e SV |
7993 | if (IS_ERR(tg)) |
7994 | return ERR_PTR(-ENOMEM); | |
7995 | ||
68318b8e SV |
7996 | return &tg->css; |
7997 | } | |
7998 | ||
eb95419b | 7999 | static int cpu_cgroup_css_online(struct cgroup_subsys_state *css) |
ace783b9 | 8000 | { |
eb95419b | 8001 | struct task_group *tg = css_tg(css); |
5c9d535b | 8002 | struct task_group *parent = css_tg(css->parent); |
ace783b9 | 8003 | |
63876986 TH |
8004 | if (parent) |
8005 | sched_online_group(tg, parent); | |
ace783b9 LZ |
8006 | return 0; |
8007 | } | |
8008 | ||
eb95419b | 8009 | static void cpu_cgroup_css_free(struct cgroup_subsys_state *css) |
68318b8e | 8010 | { |
eb95419b | 8011 | struct task_group *tg = css_tg(css); |
68318b8e SV |
8012 | |
8013 | sched_destroy_group(tg); | |
8014 | } | |
8015 | ||
eb95419b | 8016 | static void cpu_cgroup_css_offline(struct cgroup_subsys_state *css) |
ace783b9 | 8017 | { |
eb95419b | 8018 | struct task_group *tg = css_tg(css); |
ace783b9 LZ |
8019 | |
8020 | sched_offline_group(tg); | |
8021 | } | |
8022 | ||
eeb61e53 KT |
8023 | static void cpu_cgroup_fork(struct task_struct *task) |
8024 | { | |
8025 | sched_move_task(task); | |
8026 | } | |
8027 | ||
eb95419b | 8028 | static int cpu_cgroup_can_attach(struct cgroup_subsys_state *css, |
bb9d97b6 | 8029 | struct cgroup_taskset *tset) |
68318b8e | 8030 | { |
bb9d97b6 TH |
8031 | struct task_struct *task; |
8032 | ||
924f0d9a | 8033 | cgroup_taskset_for_each(task, tset) { |
b68aa230 | 8034 | #ifdef CONFIG_RT_GROUP_SCHED |
eb95419b | 8035 | if (!sched_rt_can_attach(css_tg(css), task)) |
bb9d97b6 | 8036 | return -EINVAL; |
b68aa230 | 8037 | #else |
bb9d97b6 TH |
8038 | /* We don't support RT-tasks being in separate groups */ |
8039 | if (task->sched_class != &fair_sched_class) | |
8040 | return -EINVAL; | |
b68aa230 | 8041 | #endif |
bb9d97b6 | 8042 | } |
be367d09 BB |
8043 | return 0; |
8044 | } | |
68318b8e | 8045 | |
eb95419b | 8046 | static void cpu_cgroup_attach(struct cgroup_subsys_state *css, |
bb9d97b6 | 8047 | struct cgroup_taskset *tset) |
68318b8e | 8048 | { |
bb9d97b6 TH |
8049 | struct task_struct *task; |
8050 | ||
924f0d9a | 8051 | cgroup_taskset_for_each(task, tset) |
bb9d97b6 | 8052 | sched_move_task(task); |
68318b8e SV |
8053 | } |
8054 | ||
eb95419b TH |
8055 | static void cpu_cgroup_exit(struct cgroup_subsys_state *css, |
8056 | struct cgroup_subsys_state *old_css, | |
8057 | struct task_struct *task) | |
068c5cc5 PZ |
8058 | { |
8059 | /* | |
8060 | * cgroup_exit() is called in the copy_process() failure path. | |
8061 | * Ignore this case since the task hasn't ran yet, this avoids | |
8062 | * trying to poke a half freed task state from generic code. | |
8063 | */ | |
8064 | if (!(task->flags & PF_EXITING)) | |
8065 | return; | |
8066 | ||
8067 | sched_move_task(task); | |
8068 | } | |
8069 | ||
052f1dc7 | 8070 | #ifdef CONFIG_FAIR_GROUP_SCHED |
182446d0 TH |
8071 | static int cpu_shares_write_u64(struct cgroup_subsys_state *css, |
8072 | struct cftype *cftype, u64 shareval) | |
68318b8e | 8073 | { |
182446d0 | 8074 | return sched_group_set_shares(css_tg(css), scale_load(shareval)); |
68318b8e SV |
8075 | } |
8076 | ||
182446d0 TH |
8077 | static u64 cpu_shares_read_u64(struct cgroup_subsys_state *css, |
8078 | struct cftype *cft) | |
68318b8e | 8079 | { |
182446d0 | 8080 | struct task_group *tg = css_tg(css); |
68318b8e | 8081 | |
c8b28116 | 8082 | return (u64) scale_load_down(tg->shares); |
68318b8e | 8083 | } |
ab84d31e PT |
8084 | |
8085 | #ifdef CONFIG_CFS_BANDWIDTH | |
a790de99 PT |
8086 | static DEFINE_MUTEX(cfs_constraints_mutex); |
8087 | ||
ab84d31e PT |
8088 | const u64 max_cfs_quota_period = 1 * NSEC_PER_SEC; /* 1s */ |
8089 | const u64 min_cfs_quota_period = 1 * NSEC_PER_MSEC; /* 1ms */ | |
8090 | ||
a790de99 PT |
8091 | static int __cfs_schedulable(struct task_group *tg, u64 period, u64 runtime); |
8092 | ||
ab84d31e PT |
8093 | static int tg_set_cfs_bandwidth(struct task_group *tg, u64 period, u64 quota) |
8094 | { | |
56f570e5 | 8095 | int i, ret = 0, runtime_enabled, runtime_was_enabled; |
029632fb | 8096 | struct cfs_bandwidth *cfs_b = &tg->cfs_bandwidth; |
ab84d31e PT |
8097 | |
8098 | if (tg == &root_task_group) | |
8099 | return -EINVAL; | |
8100 | ||
8101 | /* | |
8102 | * Ensure we have at some amount of bandwidth every period. This is | |
8103 | * to prevent reaching a state of large arrears when throttled via | |
8104 | * entity_tick() resulting in prolonged exit starvation. | |
8105 | */ | |
8106 | if (quota < min_cfs_quota_period || period < min_cfs_quota_period) | |
8107 | return -EINVAL; | |
8108 | ||
8109 | /* | |
8110 | * Likewise, bound things on the otherside by preventing insane quota | |
8111 | * periods. This also allows us to normalize in computing quota | |
8112 | * feasibility. | |
8113 | */ | |
8114 | if (period > max_cfs_quota_period) | |
8115 | return -EINVAL; | |
8116 | ||
0e59bdae KT |
8117 | /* |
8118 | * Prevent race between setting of cfs_rq->runtime_enabled and | |
8119 | * unthrottle_offline_cfs_rqs(). | |
8120 | */ | |
8121 | get_online_cpus(); | |
a790de99 PT |
8122 | mutex_lock(&cfs_constraints_mutex); |
8123 | ret = __cfs_schedulable(tg, period, quota); | |
8124 | if (ret) | |
8125 | goto out_unlock; | |
8126 | ||
58088ad0 | 8127 | runtime_enabled = quota != RUNTIME_INF; |
56f570e5 | 8128 | runtime_was_enabled = cfs_b->quota != RUNTIME_INF; |
1ee14e6c BS |
8129 | /* |
8130 | * If we need to toggle cfs_bandwidth_used, off->on must occur | |
8131 | * before making related changes, and on->off must occur afterwards | |
8132 | */ | |
8133 | if (runtime_enabled && !runtime_was_enabled) | |
8134 | cfs_bandwidth_usage_inc(); | |
ab84d31e PT |
8135 | raw_spin_lock_irq(&cfs_b->lock); |
8136 | cfs_b->period = ns_to_ktime(period); | |
8137 | cfs_b->quota = quota; | |
58088ad0 | 8138 | |
a9cf55b2 | 8139 | __refill_cfs_bandwidth_runtime(cfs_b); |
58088ad0 PT |
8140 | /* restart the period timer (if active) to handle new period expiry */ |
8141 | if (runtime_enabled && cfs_b->timer_active) { | |
8142 | /* force a reprogram */ | |
09dc4ab0 | 8143 | __start_cfs_bandwidth(cfs_b, true); |
58088ad0 | 8144 | } |
ab84d31e PT |
8145 | raw_spin_unlock_irq(&cfs_b->lock); |
8146 | ||
0e59bdae | 8147 | for_each_online_cpu(i) { |
ab84d31e | 8148 | struct cfs_rq *cfs_rq = tg->cfs_rq[i]; |
029632fb | 8149 | struct rq *rq = cfs_rq->rq; |
ab84d31e PT |
8150 | |
8151 | raw_spin_lock_irq(&rq->lock); | |
58088ad0 | 8152 | cfs_rq->runtime_enabled = runtime_enabled; |
ab84d31e | 8153 | cfs_rq->runtime_remaining = 0; |
671fd9da | 8154 | |
029632fb | 8155 | if (cfs_rq->throttled) |
671fd9da | 8156 | unthrottle_cfs_rq(cfs_rq); |
ab84d31e PT |
8157 | raw_spin_unlock_irq(&rq->lock); |
8158 | } | |
1ee14e6c BS |
8159 | if (runtime_was_enabled && !runtime_enabled) |
8160 | cfs_bandwidth_usage_dec(); | |
a790de99 PT |
8161 | out_unlock: |
8162 | mutex_unlock(&cfs_constraints_mutex); | |
0e59bdae | 8163 | put_online_cpus(); |
ab84d31e | 8164 | |
a790de99 | 8165 | return ret; |
ab84d31e PT |
8166 | } |
8167 | ||
8168 | int tg_set_cfs_quota(struct task_group *tg, long cfs_quota_us) | |
8169 | { | |
8170 | u64 quota, period; | |
8171 | ||
029632fb | 8172 | period = ktime_to_ns(tg->cfs_bandwidth.period); |
ab84d31e PT |
8173 | if (cfs_quota_us < 0) |
8174 | quota = RUNTIME_INF; | |
8175 | else | |
8176 | quota = (u64)cfs_quota_us * NSEC_PER_USEC; | |
8177 | ||
8178 | return tg_set_cfs_bandwidth(tg, period, quota); | |
8179 | } | |
8180 | ||
8181 | long tg_get_cfs_quota(struct task_group *tg) | |
8182 | { | |
8183 | u64 quota_us; | |
8184 | ||
029632fb | 8185 | if (tg->cfs_bandwidth.quota == RUNTIME_INF) |
ab84d31e PT |
8186 | return -1; |
8187 | ||
029632fb | 8188 | quota_us = tg->cfs_bandwidth.quota; |
ab84d31e PT |
8189 | do_div(quota_us, NSEC_PER_USEC); |
8190 | ||
8191 | return quota_us; | |
8192 | } | |
8193 | ||
8194 | int tg_set_cfs_period(struct task_group *tg, long cfs_period_us) | |
8195 | { | |
8196 | u64 quota, period; | |
8197 | ||
8198 | period = (u64)cfs_period_us * NSEC_PER_USEC; | |
029632fb | 8199 | quota = tg->cfs_bandwidth.quota; |
ab84d31e | 8200 | |
ab84d31e PT |
8201 | return tg_set_cfs_bandwidth(tg, period, quota); |
8202 | } | |
8203 | ||
8204 | long tg_get_cfs_period(struct task_group *tg) | |
8205 | { | |
8206 | u64 cfs_period_us; | |
8207 | ||
029632fb | 8208 | cfs_period_us = ktime_to_ns(tg->cfs_bandwidth.period); |
ab84d31e PT |
8209 | do_div(cfs_period_us, NSEC_PER_USEC); |
8210 | ||
8211 | return cfs_period_us; | |
8212 | } | |
8213 | ||
182446d0 TH |
8214 | static s64 cpu_cfs_quota_read_s64(struct cgroup_subsys_state *css, |
8215 | struct cftype *cft) | |
ab84d31e | 8216 | { |
182446d0 | 8217 | return tg_get_cfs_quota(css_tg(css)); |
ab84d31e PT |
8218 | } |
8219 | ||
182446d0 TH |
8220 | static int cpu_cfs_quota_write_s64(struct cgroup_subsys_state *css, |
8221 | struct cftype *cftype, s64 cfs_quota_us) | |
ab84d31e | 8222 | { |
182446d0 | 8223 | return tg_set_cfs_quota(css_tg(css), cfs_quota_us); |
ab84d31e PT |
8224 | } |
8225 | ||
182446d0 TH |
8226 | static u64 cpu_cfs_period_read_u64(struct cgroup_subsys_state *css, |
8227 | struct cftype *cft) | |
ab84d31e | 8228 | { |
182446d0 | 8229 | return tg_get_cfs_period(css_tg(css)); |
ab84d31e PT |
8230 | } |
8231 | ||
182446d0 TH |
8232 | static int cpu_cfs_period_write_u64(struct cgroup_subsys_state *css, |
8233 | struct cftype *cftype, u64 cfs_period_us) | |
ab84d31e | 8234 | { |
182446d0 | 8235 | return tg_set_cfs_period(css_tg(css), cfs_period_us); |
ab84d31e PT |
8236 | } |
8237 | ||
a790de99 PT |
8238 | struct cfs_schedulable_data { |
8239 | struct task_group *tg; | |
8240 | u64 period, quota; | |
8241 | }; | |
8242 | ||
8243 | /* | |
8244 | * normalize group quota/period to be quota/max_period | |
8245 | * note: units are usecs | |
8246 | */ | |
8247 | static u64 normalize_cfs_quota(struct task_group *tg, | |
8248 | struct cfs_schedulable_data *d) | |
8249 | { | |
8250 | u64 quota, period; | |
8251 | ||
8252 | if (tg == d->tg) { | |
8253 | period = d->period; | |
8254 | quota = d->quota; | |
8255 | } else { | |
8256 | period = tg_get_cfs_period(tg); | |
8257 | quota = tg_get_cfs_quota(tg); | |
8258 | } | |
8259 | ||
8260 | /* note: these should typically be equivalent */ | |
8261 | if (quota == RUNTIME_INF || quota == -1) | |
8262 | return RUNTIME_INF; | |
8263 | ||
8264 | return to_ratio(period, quota); | |
8265 | } | |
8266 | ||
8267 | static int tg_cfs_schedulable_down(struct task_group *tg, void *data) | |
8268 | { | |
8269 | struct cfs_schedulable_data *d = data; | |
029632fb | 8270 | struct cfs_bandwidth *cfs_b = &tg->cfs_bandwidth; |
a790de99 PT |
8271 | s64 quota = 0, parent_quota = -1; |
8272 | ||
8273 | if (!tg->parent) { | |
8274 | quota = RUNTIME_INF; | |
8275 | } else { | |
029632fb | 8276 | struct cfs_bandwidth *parent_b = &tg->parent->cfs_bandwidth; |
a790de99 PT |
8277 | |
8278 | quota = normalize_cfs_quota(tg, d); | |
9c58c79a | 8279 | parent_quota = parent_b->hierarchical_quota; |
a790de99 PT |
8280 | |
8281 | /* | |
8282 | * ensure max(child_quota) <= parent_quota, inherit when no | |
8283 | * limit is set | |
8284 | */ | |
8285 | if (quota == RUNTIME_INF) | |
8286 | quota = parent_quota; | |
8287 | else if (parent_quota != RUNTIME_INF && quota > parent_quota) | |
8288 | return -EINVAL; | |
8289 | } | |
9c58c79a | 8290 | cfs_b->hierarchical_quota = quota; |
a790de99 PT |
8291 | |
8292 | return 0; | |
8293 | } | |
8294 | ||
8295 | static int __cfs_schedulable(struct task_group *tg, u64 period, u64 quota) | |
8296 | { | |
8277434e | 8297 | int ret; |
a790de99 PT |
8298 | struct cfs_schedulable_data data = { |
8299 | .tg = tg, | |
8300 | .period = period, | |
8301 | .quota = quota, | |
8302 | }; | |
8303 | ||
8304 | if (quota != RUNTIME_INF) { | |
8305 | do_div(data.period, NSEC_PER_USEC); | |
8306 | do_div(data.quota, NSEC_PER_USEC); | |
8307 | } | |
8308 | ||
8277434e PT |
8309 | rcu_read_lock(); |
8310 | ret = walk_tg_tree(tg_cfs_schedulable_down, tg_nop, &data); | |
8311 | rcu_read_unlock(); | |
8312 | ||
8313 | return ret; | |
a790de99 | 8314 | } |
e8da1b18 | 8315 | |
2da8ca82 | 8316 | static int cpu_stats_show(struct seq_file *sf, void *v) |
e8da1b18 | 8317 | { |
2da8ca82 | 8318 | struct task_group *tg = css_tg(seq_css(sf)); |
029632fb | 8319 | struct cfs_bandwidth *cfs_b = &tg->cfs_bandwidth; |
e8da1b18 | 8320 | |
44ffc75b TH |
8321 | seq_printf(sf, "nr_periods %d\n", cfs_b->nr_periods); |
8322 | seq_printf(sf, "nr_throttled %d\n", cfs_b->nr_throttled); | |
8323 | seq_printf(sf, "throttled_time %llu\n", cfs_b->throttled_time); | |
e8da1b18 NR |
8324 | |
8325 | return 0; | |
8326 | } | |
ab84d31e | 8327 | #endif /* CONFIG_CFS_BANDWIDTH */ |
6d6bc0ad | 8328 | #endif /* CONFIG_FAIR_GROUP_SCHED */ |
68318b8e | 8329 | |
052f1dc7 | 8330 | #ifdef CONFIG_RT_GROUP_SCHED |
182446d0 TH |
8331 | static int cpu_rt_runtime_write(struct cgroup_subsys_state *css, |
8332 | struct cftype *cft, s64 val) | |
6f505b16 | 8333 | { |
182446d0 | 8334 | return sched_group_set_rt_runtime(css_tg(css), val); |
6f505b16 PZ |
8335 | } |
8336 | ||
182446d0 TH |
8337 | static s64 cpu_rt_runtime_read(struct cgroup_subsys_state *css, |
8338 | struct cftype *cft) | |
6f505b16 | 8339 | { |
182446d0 | 8340 | return sched_group_rt_runtime(css_tg(css)); |
6f505b16 | 8341 | } |
d0b27fa7 | 8342 | |
182446d0 TH |
8343 | static int cpu_rt_period_write_uint(struct cgroup_subsys_state *css, |
8344 | struct cftype *cftype, u64 rt_period_us) | |
d0b27fa7 | 8345 | { |
182446d0 | 8346 | return sched_group_set_rt_period(css_tg(css), rt_period_us); |
d0b27fa7 PZ |
8347 | } |
8348 | ||
182446d0 TH |
8349 | static u64 cpu_rt_period_read_uint(struct cgroup_subsys_state *css, |
8350 | struct cftype *cft) | |
d0b27fa7 | 8351 | { |
182446d0 | 8352 | return sched_group_rt_period(css_tg(css)); |
d0b27fa7 | 8353 | } |
6d6bc0ad | 8354 | #endif /* CONFIG_RT_GROUP_SCHED */ |
6f505b16 | 8355 | |
fe5c7cc2 | 8356 | static struct cftype cpu_files[] = { |
052f1dc7 | 8357 | #ifdef CONFIG_FAIR_GROUP_SCHED |
fe5c7cc2 PM |
8358 | { |
8359 | .name = "shares", | |
f4c753b7 PM |
8360 | .read_u64 = cpu_shares_read_u64, |
8361 | .write_u64 = cpu_shares_write_u64, | |
fe5c7cc2 | 8362 | }, |
052f1dc7 | 8363 | #endif |
ab84d31e PT |
8364 | #ifdef CONFIG_CFS_BANDWIDTH |
8365 | { | |
8366 | .name = "cfs_quota_us", | |
8367 | .read_s64 = cpu_cfs_quota_read_s64, | |
8368 | .write_s64 = cpu_cfs_quota_write_s64, | |
8369 | }, | |
8370 | { | |
8371 | .name = "cfs_period_us", | |
8372 | .read_u64 = cpu_cfs_period_read_u64, | |
8373 | .write_u64 = cpu_cfs_period_write_u64, | |
8374 | }, | |
e8da1b18 NR |
8375 | { |
8376 | .name = "stat", | |
2da8ca82 | 8377 | .seq_show = cpu_stats_show, |
e8da1b18 | 8378 | }, |
ab84d31e | 8379 | #endif |
052f1dc7 | 8380 | #ifdef CONFIG_RT_GROUP_SCHED |
6f505b16 | 8381 | { |
9f0c1e56 | 8382 | .name = "rt_runtime_us", |
06ecb27c PM |
8383 | .read_s64 = cpu_rt_runtime_read, |
8384 | .write_s64 = cpu_rt_runtime_write, | |
6f505b16 | 8385 | }, |
d0b27fa7 PZ |
8386 | { |
8387 | .name = "rt_period_us", | |
f4c753b7 PM |
8388 | .read_u64 = cpu_rt_period_read_uint, |
8389 | .write_u64 = cpu_rt_period_write_uint, | |
d0b27fa7 | 8390 | }, |
052f1dc7 | 8391 | #endif |
4baf6e33 | 8392 | { } /* terminate */ |
68318b8e SV |
8393 | }; |
8394 | ||
073219e9 | 8395 | struct cgroup_subsys cpu_cgrp_subsys = { |
92fb9748 TH |
8396 | .css_alloc = cpu_cgroup_css_alloc, |
8397 | .css_free = cpu_cgroup_css_free, | |
ace783b9 LZ |
8398 | .css_online = cpu_cgroup_css_online, |
8399 | .css_offline = cpu_cgroup_css_offline, | |
eeb61e53 | 8400 | .fork = cpu_cgroup_fork, |
bb9d97b6 TH |
8401 | .can_attach = cpu_cgroup_can_attach, |
8402 | .attach = cpu_cgroup_attach, | |
068c5cc5 | 8403 | .exit = cpu_cgroup_exit, |
5577964e | 8404 | .legacy_cftypes = cpu_files, |
68318b8e SV |
8405 | .early_init = 1, |
8406 | }; | |
8407 | ||
052f1dc7 | 8408 | #endif /* CONFIG_CGROUP_SCHED */ |
d842de87 | 8409 | |
b637a328 PM |
8410 | void dump_cpu_task(int cpu) |
8411 | { | |
8412 | pr_info("Task dump for CPU %d:\n", cpu); | |
8413 | sched_show_task(cpu_curr(cpu)); | |
8414 | } |