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1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3 * Scheduler internal types and methods:
4 */
5 #include <linux/sched.h>
6
7 #include <linux/sched/autogroup.h>
8 #include <linux/sched/clock.h>
9 #include <linux/sched/coredump.h>
10 #include <linux/sched/cpufreq.h>
11 #include <linux/sched/cputime.h>
12 #include <linux/sched/deadline.h>
13 #include <linux/sched/debug.h>
14 #include <linux/sched/hotplug.h>
15 #include <linux/sched/idle.h>
16 #include <linux/sched/init.h>
17 #include <linux/sched/isolation.h>
18 #include <linux/sched/jobctl.h>
19 #include <linux/sched/loadavg.h>
20 #include <linux/sched/mm.h>
21 #include <linux/sched/nohz.h>
22 #include <linux/sched/numa_balancing.h>
23 #include <linux/sched/prio.h>
24 #include <linux/sched/rt.h>
25 #include <linux/sched/signal.h>
26 #include <linux/sched/smt.h>
27 #include <linux/sched/stat.h>
28 #include <linux/sched/sysctl.h>
29 #include <linux/sched/task.h>
30 #include <linux/sched/task_stack.h>
31 #include <linux/sched/topology.h>
32 #include <linux/sched/user.h>
33 #include <linux/sched/wake_q.h>
34 #include <linux/sched/xacct.h>
35
36 #include <uapi/linux/sched/types.h>
37
38 #include <linux/binfmts.h>
39 #include <linux/blkdev.h>
40 #include <linux/compat.h>
41 #include <linux/context_tracking.h>
42 #include <linux/cpufreq.h>
43 #include <linux/cpuidle.h>
44 #include <linux/cpuset.h>
45 #include <linux/ctype.h>
46 #include <linux/debugfs.h>
47 #include <linux/delayacct.h>
48 #include <linux/energy_model.h>
49 #include <linux/init_task.h>
50 #include <linux/kprobes.h>
51 #include <linux/kthread.h>
52 #include <linux/membarrier.h>
53 #include <linux/migrate.h>
54 #include <linux/mmu_context.h>
55 #include <linux/nmi.h>
56 #include <linux/proc_fs.h>
57 #include <linux/prefetch.h>
58 #include <linux/profile.h>
59 #include <linux/psi.h>
60 #include <linux/rcupdate_wait.h>
61 #include <linux/security.h>
62 #include <linux/stop_machine.h>
63 #include <linux/suspend.h>
64 #include <linux/swait.h>
65 #include <linux/syscalls.h>
66 #include <linux/task_work.h>
67 #include <linux/tsacct_kern.h>
68
69 #include <asm/tlb.h>
70
71 #ifdef CONFIG_PARAVIRT
72 # include <asm/paravirt.h>
73 #endif
74
75 #include "cpupri.h"
76 #include "cpudeadline.h"
77
78 #ifdef CONFIG_SCHED_DEBUG
79 # define SCHED_WARN_ON(x) WARN_ONCE(x, #x)
80 #else
81 # define SCHED_WARN_ON(x) ({ (void)(x), 0; })
82 #endif
83
84 struct rq;
85 struct cpuidle_state;
86
87 /* task_struct::on_rq states: */
88 #define TASK_ON_RQ_QUEUED 1
89 #define TASK_ON_RQ_MIGRATING 2
90
91 extern __read_mostly int scheduler_running;
92
93 extern unsigned long calc_load_update;
94 extern atomic_long_t calc_load_tasks;
95
96 extern void calc_global_load_tick(struct rq *this_rq);
97 extern long calc_load_fold_active(struct rq *this_rq, long adjust);
98
99 /*
100 * Helpers for converting nanosecond timing to jiffy resolution
101 */
102 #define NS_TO_JIFFIES(TIME) ((unsigned long)(TIME) / (NSEC_PER_SEC / HZ))
103
104 /*
105 * Increase resolution of nice-level calculations for 64-bit architectures.
106 * The extra resolution improves shares distribution and load balancing of
107 * low-weight task groups (eg. nice +19 on an autogroup), deeper taskgroup
108 * hierarchies, especially on larger systems. This is not a user-visible change
109 * and does not change the user-interface for setting shares/weights.
110 *
111 * We increase resolution only if we have enough bits to allow this increased
112 * resolution (i.e. 64-bit). The costs for increasing resolution when 32-bit
113 * are pretty high and the returns do not justify the increased costs.
114 *
115 * Really only required when CONFIG_FAIR_GROUP_SCHED=y is also set, but to
116 * increase coverage and consistency always enable it on 64-bit platforms.
117 */
118 #ifdef CONFIG_64BIT
119 # define NICE_0_LOAD_SHIFT (SCHED_FIXEDPOINT_SHIFT + SCHED_FIXEDPOINT_SHIFT)
120 # define scale_load(w) ((w) << SCHED_FIXEDPOINT_SHIFT)
121 # define scale_load_down(w) \
122 ({ \
123 unsigned long __w = (w); \
124 if (__w) \
125 __w = max(2UL, __w >> SCHED_FIXEDPOINT_SHIFT); \
126 __w; \
127 })
128 #else
129 # define NICE_0_LOAD_SHIFT (SCHED_FIXEDPOINT_SHIFT)
130 # define scale_load(w) (w)
131 # define scale_load_down(w) (w)
132 #endif
133
134 /*
135 * Task weight (visible to users) and its load (invisible to users) have
136 * independent resolution, but they should be well calibrated. We use
137 * scale_load() and scale_load_down(w) to convert between them. The
138 * following must be true:
139 *
140 * scale_load(sched_prio_to_weight[USER_PRIO(NICE_TO_PRIO(0))]) == NICE_0_LOAD
141 *
142 */
143 #define NICE_0_LOAD (1L << NICE_0_LOAD_SHIFT)
144
145 /*
146 * Single value that decides SCHED_DEADLINE internal math precision.
147 * 10 -> just above 1us
148 * 9 -> just above 0.5us
149 */
150 #define DL_SCALE 10
151
152 /*
153 * Single value that denotes runtime == period, ie unlimited time.
154 */
155 #define RUNTIME_INF ((u64)~0ULL)
156
157 static inline int idle_policy(int policy)
158 {
159 return policy == SCHED_IDLE;
160 }
161 static inline int fair_policy(int policy)
162 {
163 return policy == SCHED_NORMAL || policy == SCHED_BATCH;
164 }
165
166 static inline int rt_policy(int policy)
167 {
168 return policy == SCHED_FIFO || policy == SCHED_RR;
169 }
170
171 static inline int dl_policy(int policy)
172 {
173 return policy == SCHED_DEADLINE;
174 }
175 static inline bool valid_policy(int policy)
176 {
177 return idle_policy(policy) || fair_policy(policy) ||
178 rt_policy(policy) || dl_policy(policy);
179 }
180
181 static inline int task_has_idle_policy(struct task_struct *p)
182 {
183 return idle_policy(p->policy);
184 }
185
186 static inline int task_has_rt_policy(struct task_struct *p)
187 {
188 return rt_policy(p->policy);
189 }
190
191 static inline int task_has_dl_policy(struct task_struct *p)
192 {
193 return dl_policy(p->policy);
194 }
195
196 #define cap_scale(v, s) ((v)*(s) >> SCHED_CAPACITY_SHIFT)
197
198 static inline void update_avg(u64 *avg, u64 sample)
199 {
200 s64 diff = sample - *avg;
201 *avg += diff / 8;
202 }
203
204 /*
205 * !! For sched_setattr_nocheck() (kernel) only !!
206 *
207 * This is actually gross. :(
208 *
209 * It is used to make schedutil kworker(s) higher priority than SCHED_DEADLINE
210 * tasks, but still be able to sleep. We need this on platforms that cannot
211 * atomically change clock frequency. Remove once fast switching will be
212 * available on such platforms.
213 *
214 * SUGOV stands for SchedUtil GOVernor.
215 */
216 #define SCHED_FLAG_SUGOV 0x10000000
217
218 static inline bool dl_entity_is_special(struct sched_dl_entity *dl_se)
219 {
220 #ifdef CONFIG_CPU_FREQ_GOV_SCHEDUTIL
221 return unlikely(dl_se->flags & SCHED_FLAG_SUGOV);
222 #else
223 return false;
224 #endif
225 }
226
227 /*
228 * Tells if entity @a should preempt entity @b.
229 */
230 static inline bool
231 dl_entity_preempt(struct sched_dl_entity *a, struct sched_dl_entity *b)
232 {
233 return dl_entity_is_special(a) ||
234 dl_time_before(a->deadline, b->deadline);
235 }
236
237 /*
238 * This is the priority-queue data structure of the RT scheduling class:
239 */
240 struct rt_prio_array {
241 DECLARE_BITMAP(bitmap, MAX_RT_PRIO+1); /* include 1 bit for delimiter */
242 struct list_head queue[MAX_RT_PRIO];
243 };
244
245 struct rt_bandwidth {
246 /* nests inside the rq lock: */
247 raw_spinlock_t rt_runtime_lock;
248 ktime_t rt_period;
249 u64 rt_runtime;
250 struct hrtimer rt_period_timer;
251 unsigned int rt_period_active;
252 };
253
254 void __dl_clear_params(struct task_struct *p);
255
256 /*
257 * To keep the bandwidth of -deadline tasks and groups under control
258 * we need some place where:
259 * - store the maximum -deadline bandwidth of the system (the group);
260 * - cache the fraction of that bandwidth that is currently allocated.
261 *
262 * This is all done in the data structure below. It is similar to the
263 * one used for RT-throttling (rt_bandwidth), with the main difference
264 * that, since here we are only interested in admission control, we
265 * do not decrease any runtime while the group "executes", neither we
266 * need a timer to replenish it.
267 *
268 * With respect to SMP, the bandwidth is given on a per-CPU basis,
269 * meaning that:
270 * - dl_bw (< 100%) is the bandwidth of the system (group) on each CPU;
271 * - dl_total_bw array contains, in the i-eth element, the currently
272 * allocated bandwidth on the i-eth CPU.
273 * Moreover, groups consume bandwidth on each CPU, while tasks only
274 * consume bandwidth on the CPU they're running on.
275 * Finally, dl_total_bw_cpu is used to cache the index of dl_total_bw
276 * that will be shown the next time the proc or cgroup controls will
277 * be red. It on its turn can be changed by writing on its own
278 * control.
279 */
280 struct dl_bandwidth {
281 raw_spinlock_t dl_runtime_lock;
282 u64 dl_runtime;
283 u64 dl_period;
284 };
285
286 static inline int dl_bandwidth_enabled(void)
287 {
288 return sysctl_sched_rt_runtime >= 0;
289 }
290
291 struct dl_bw {
292 raw_spinlock_t lock;
293 u64 bw;
294 u64 total_bw;
295 };
296
297 static inline void __dl_update(struct dl_bw *dl_b, s64 bw);
298
299 static inline
300 void __dl_sub(struct dl_bw *dl_b, u64 tsk_bw, int cpus)
301 {
302 dl_b->total_bw -= tsk_bw;
303 __dl_update(dl_b, (s32)tsk_bw / cpus);
304 }
305
306 static inline
307 void __dl_add(struct dl_bw *dl_b, u64 tsk_bw, int cpus)
308 {
309 dl_b->total_bw += tsk_bw;
310 __dl_update(dl_b, -((s32)tsk_bw / cpus));
311 }
312
313 static inline
314 bool __dl_overflow(struct dl_bw *dl_b, int cpus, u64 old_bw, u64 new_bw)
315 {
316 return dl_b->bw != -1 &&
317 dl_b->bw * cpus < dl_b->total_bw - old_bw + new_bw;
318 }
319
320 extern void init_dl_bw(struct dl_bw *dl_b);
321 extern int sched_dl_global_validate(void);
322 extern void sched_dl_do_global(void);
323 extern int sched_dl_overflow(struct task_struct *p, int policy, const struct sched_attr *attr);
324 extern void __setparam_dl(struct task_struct *p, const struct sched_attr *attr);
325 extern void __getparam_dl(struct task_struct *p, struct sched_attr *attr);
326 extern bool __checkparam_dl(const struct sched_attr *attr);
327 extern bool dl_param_changed(struct task_struct *p, const struct sched_attr *attr);
328 extern int dl_task_can_attach(struct task_struct *p, const struct cpumask *cs_cpus_allowed);
329 extern int dl_cpuset_cpumask_can_shrink(const struct cpumask *cur, const struct cpumask *trial);
330 extern bool dl_cpu_busy(unsigned int cpu);
331
332 #ifdef CONFIG_CGROUP_SCHED
333
334 #include <linux/cgroup.h>
335 #include <linux/psi.h>
336
337 struct cfs_rq;
338 struct rt_rq;
339
340 extern struct list_head task_groups;
341
342 struct cfs_bandwidth {
343 #ifdef CONFIG_CFS_BANDWIDTH
344 raw_spinlock_t lock;
345 ktime_t period;
346 u64 quota;
347 u64 runtime;
348 s64 hierarchical_quota;
349
350 u8 idle;
351 u8 period_active;
352 u8 distribute_running;
353 u8 slack_started;
354 struct hrtimer period_timer;
355 struct hrtimer slack_timer;
356 struct list_head throttled_cfs_rq;
357
358 /* Statistics: */
359 int nr_periods;
360 int nr_throttled;
361 u64 throttled_time;
362 #endif
363 };
364
365 /* Task group related information */
366 struct task_group {
367 struct cgroup_subsys_state css;
368
369 #ifdef CONFIG_FAIR_GROUP_SCHED
370 /* schedulable entities of this group on each CPU */
371 struct sched_entity **se;
372 /* runqueue "owned" by this group on each CPU */
373 struct cfs_rq **cfs_rq;
374 unsigned long shares;
375
376 #ifdef CONFIG_SMP
377 /*
378 * load_avg can be heavily contended at clock tick time, so put
379 * it in its own cacheline separated from the fields above which
380 * will also be accessed at each tick.
381 */
382 atomic_long_t load_avg ____cacheline_aligned;
383 #endif
384 #endif
385
386 #ifdef CONFIG_RT_GROUP_SCHED
387 struct sched_rt_entity **rt_se;
388 struct rt_rq **rt_rq;
389
390 struct rt_bandwidth rt_bandwidth;
391 #endif
392
393 struct rcu_head rcu;
394 struct list_head list;
395
396 struct task_group *parent;
397 struct list_head siblings;
398 struct list_head children;
399
400 #ifdef CONFIG_SCHED_AUTOGROUP
401 struct autogroup *autogroup;
402 #endif
403
404 struct cfs_bandwidth cfs_bandwidth;
405
406 #ifdef CONFIG_UCLAMP_TASK_GROUP
407 /* The two decimal precision [%] value requested from user-space */
408 unsigned int uclamp_pct[UCLAMP_CNT];
409 /* Clamp values requested for a task group */
410 struct uclamp_se uclamp_req[UCLAMP_CNT];
411 /* Effective clamp values used for a task group */
412 struct uclamp_se uclamp[UCLAMP_CNT];
413 #endif
414
415 };
416
417 #ifdef CONFIG_FAIR_GROUP_SCHED
418 #define ROOT_TASK_GROUP_LOAD NICE_0_LOAD
419
420 /*
421 * A weight of 0 or 1 can cause arithmetics problems.
422 * A weight of a cfs_rq is the sum of weights of which entities
423 * are queued on this cfs_rq, so a weight of a entity should not be
424 * too large, so as the shares value of a task group.
425 * (The default weight is 1024 - so there's no practical
426 * limitation from this.)
427 */
428 #define MIN_SHARES (1UL << 1)
429 #define MAX_SHARES (1UL << 18)
430 #endif
431
432 typedef int (*tg_visitor)(struct task_group *, void *);
433
434 extern int walk_tg_tree_from(struct task_group *from,
435 tg_visitor down, tg_visitor up, void *data);
436
437 /*
438 * Iterate the full tree, calling @down when first entering a node and @up when
439 * leaving it for the final time.
440 *
441 * Caller must hold rcu_lock or sufficient equivalent.
442 */
443 static inline int walk_tg_tree(tg_visitor down, tg_visitor up, void *data)
444 {
445 return walk_tg_tree_from(&root_task_group, down, up, data);
446 }
447
448 extern int tg_nop(struct task_group *tg, void *data);
449
450 extern void free_fair_sched_group(struct task_group *tg);
451 extern int alloc_fair_sched_group(struct task_group *tg, struct task_group *parent);
452 extern void online_fair_sched_group(struct task_group *tg);
453 extern void unregister_fair_sched_group(struct task_group *tg);
454 extern void init_tg_cfs_entry(struct task_group *tg, struct cfs_rq *cfs_rq,
455 struct sched_entity *se, int cpu,
456 struct sched_entity *parent);
457 extern void init_cfs_bandwidth(struct cfs_bandwidth *cfs_b);
458
459 extern void __refill_cfs_bandwidth_runtime(struct cfs_bandwidth *cfs_b);
460 extern void start_cfs_bandwidth(struct cfs_bandwidth *cfs_b);
461 extern void unthrottle_cfs_rq(struct cfs_rq *cfs_rq);
462
463 extern void free_rt_sched_group(struct task_group *tg);
464 extern int alloc_rt_sched_group(struct task_group *tg, struct task_group *parent);
465 extern void init_tg_rt_entry(struct task_group *tg, struct rt_rq *rt_rq,
466 struct sched_rt_entity *rt_se, int cpu,
467 struct sched_rt_entity *parent);
468 extern int sched_group_set_rt_runtime(struct task_group *tg, long rt_runtime_us);
469 extern int sched_group_set_rt_period(struct task_group *tg, u64 rt_period_us);
470 extern long sched_group_rt_runtime(struct task_group *tg);
471 extern long sched_group_rt_period(struct task_group *tg);
472 extern int sched_rt_can_attach(struct task_group *tg, struct task_struct *tsk);
473
474 extern struct task_group *sched_create_group(struct task_group *parent);
475 extern void sched_online_group(struct task_group *tg,
476 struct task_group *parent);
477 extern void sched_destroy_group(struct task_group *tg);
478 extern void sched_offline_group(struct task_group *tg);
479
480 extern void sched_move_task(struct task_struct *tsk);
481
482 #ifdef CONFIG_FAIR_GROUP_SCHED
483 extern int sched_group_set_shares(struct task_group *tg, unsigned long shares);
484
485 #ifdef CONFIG_SMP
486 extern void set_task_rq_fair(struct sched_entity *se,
487 struct cfs_rq *prev, struct cfs_rq *next);
488 #else /* !CONFIG_SMP */
489 static inline void set_task_rq_fair(struct sched_entity *se,
490 struct cfs_rq *prev, struct cfs_rq *next) { }
491 #endif /* CONFIG_SMP */
492 #endif /* CONFIG_FAIR_GROUP_SCHED */
493
494 #else /* CONFIG_CGROUP_SCHED */
495
496 struct cfs_bandwidth { };
497
498 #endif /* CONFIG_CGROUP_SCHED */
499
500 /* CFS-related fields in a runqueue */
501 struct cfs_rq {
502 struct load_weight load;
503 unsigned int nr_running;
504 unsigned int h_nr_running; /* SCHED_{NORMAL,BATCH,IDLE} */
505 unsigned int idle_h_nr_running; /* SCHED_IDLE */
506
507 u64 exec_clock;
508 u64 min_vruntime;
509 #ifndef CONFIG_64BIT
510 u64 min_vruntime_copy;
511 #endif
512
513 struct rb_root_cached tasks_timeline;
514
515 /*
516 * 'curr' points to currently running entity on this cfs_rq.
517 * It is set to NULL otherwise (i.e when none are currently running).
518 */
519 struct sched_entity *curr;
520 struct sched_entity *next;
521 struct sched_entity *last;
522 struct sched_entity *skip;
523
524 #ifdef CONFIG_SCHED_DEBUG
525 unsigned int nr_spread_over;
526 #endif
527
528 #ifdef CONFIG_SMP
529 /*
530 * CFS load tracking
531 */
532 struct sched_avg avg;
533 #ifndef CONFIG_64BIT
534 u64 load_last_update_time_copy;
535 #endif
536 struct {
537 raw_spinlock_t lock ____cacheline_aligned;
538 int nr;
539 unsigned long load_avg;
540 unsigned long util_avg;
541 unsigned long runnable_avg;
542 } removed;
543
544 #ifdef CONFIG_FAIR_GROUP_SCHED
545 unsigned long tg_load_avg_contrib;
546 long propagate;
547 long prop_runnable_sum;
548
549 /*
550 * h_load = weight * f(tg)
551 *
552 * Where f(tg) is the recursive weight fraction assigned to
553 * this group.
554 */
555 unsigned long h_load;
556 u64 last_h_load_update;
557 struct sched_entity *h_load_next;
558 #endif /* CONFIG_FAIR_GROUP_SCHED */
559 #endif /* CONFIG_SMP */
560
561 #ifdef CONFIG_FAIR_GROUP_SCHED
562 struct rq *rq; /* CPU runqueue to which this cfs_rq is attached */
563
564 /*
565 * leaf cfs_rqs are those that hold tasks (lowest schedulable entity in
566 * a hierarchy). Non-leaf lrqs hold other higher schedulable entities
567 * (like users, containers etc.)
568 *
569 * leaf_cfs_rq_list ties together list of leaf cfs_rq's in a CPU.
570 * This list is used during load balance.
571 */
572 int on_list;
573 struct list_head leaf_cfs_rq_list;
574 struct task_group *tg; /* group that "owns" this runqueue */
575
576 #ifdef CONFIG_CFS_BANDWIDTH
577 int runtime_enabled;
578 s64 runtime_remaining;
579
580 u64 throttled_clock;
581 u64 throttled_clock_task;
582 u64 throttled_clock_task_time;
583 int throttled;
584 int throttle_count;
585 struct list_head throttled_list;
586 #endif /* CONFIG_CFS_BANDWIDTH */
587 #endif /* CONFIG_FAIR_GROUP_SCHED */
588 };
589
590 static inline int rt_bandwidth_enabled(void)
591 {
592 return sysctl_sched_rt_runtime >= 0;
593 }
594
595 /* RT IPI pull logic requires IRQ_WORK */
596 #if defined(CONFIG_IRQ_WORK) && defined(CONFIG_SMP)
597 # define HAVE_RT_PUSH_IPI
598 #endif
599
600 /* Real-Time classes' related field in a runqueue: */
601 struct rt_rq {
602 struct rt_prio_array active;
603 unsigned int rt_nr_running;
604 unsigned int rr_nr_running;
605 #if defined CONFIG_SMP || defined CONFIG_RT_GROUP_SCHED
606 struct {
607 int curr; /* highest queued rt task prio */
608 #ifdef CONFIG_SMP
609 int next; /* next highest */
610 #endif
611 } highest_prio;
612 #endif
613 #ifdef CONFIG_SMP
614 unsigned long rt_nr_migratory;
615 unsigned long rt_nr_total;
616 int overloaded;
617 struct plist_head pushable_tasks;
618
619 #endif /* CONFIG_SMP */
620 int rt_queued;
621
622 int rt_throttled;
623 u64 rt_time;
624 u64 rt_runtime;
625 /* Nests inside the rq lock: */
626 raw_spinlock_t rt_runtime_lock;
627
628 #ifdef CONFIG_RT_GROUP_SCHED
629 unsigned long rt_nr_boosted;
630
631 struct rq *rq;
632 struct task_group *tg;
633 #endif
634 };
635
636 static inline bool rt_rq_is_runnable(struct rt_rq *rt_rq)
637 {
638 return rt_rq->rt_queued && rt_rq->rt_nr_running;
639 }
640
641 /* Deadline class' related fields in a runqueue */
642 struct dl_rq {
643 /* runqueue is an rbtree, ordered by deadline */
644 struct rb_root_cached root;
645
646 unsigned long dl_nr_running;
647
648 #ifdef CONFIG_SMP
649 /*
650 * Deadline values of the currently executing and the
651 * earliest ready task on this rq. Caching these facilitates
652 * the decision whether or not a ready but not running task
653 * should migrate somewhere else.
654 */
655 struct {
656 u64 curr;
657 u64 next;
658 } earliest_dl;
659
660 unsigned long dl_nr_migratory;
661 int overloaded;
662
663 /*
664 * Tasks on this rq that can be pushed away. They are kept in
665 * an rb-tree, ordered by tasks' deadlines, with caching
666 * of the leftmost (earliest deadline) element.
667 */
668 struct rb_root_cached pushable_dl_tasks_root;
669 #else
670 struct dl_bw dl_bw;
671 #endif
672 /*
673 * "Active utilization" for this runqueue: increased when a
674 * task wakes up (becomes TASK_RUNNING) and decreased when a
675 * task blocks
676 */
677 u64 running_bw;
678
679 /*
680 * Utilization of the tasks "assigned" to this runqueue (including
681 * the tasks that are in runqueue and the tasks that executed on this
682 * CPU and blocked). Increased when a task moves to this runqueue, and
683 * decreased when the task moves away (migrates, changes scheduling
684 * policy, or terminates).
685 * This is needed to compute the "inactive utilization" for the
686 * runqueue (inactive utilization = this_bw - running_bw).
687 */
688 u64 this_bw;
689 u64 extra_bw;
690
691 /*
692 * Inverse of the fraction of CPU utilization that can be reclaimed
693 * by the GRUB algorithm.
694 */
695 u64 bw_ratio;
696 };
697
698 #ifdef CONFIG_FAIR_GROUP_SCHED
699 /* An entity is a task if it doesn't "own" a runqueue */
700 #define entity_is_task(se) (!se->my_q)
701
702 static inline void se_update_runnable(struct sched_entity *se)
703 {
704 if (!entity_is_task(se))
705 se->runnable_weight = se->my_q->h_nr_running;
706 }
707
708 static inline long se_runnable(struct sched_entity *se)
709 {
710 if (entity_is_task(se))
711 return !!se->on_rq;
712 else
713 return se->runnable_weight;
714 }
715
716 #else
717 #define entity_is_task(se) 1
718
719 static inline void se_update_runnable(struct sched_entity *se) {}
720
721 static inline long se_runnable(struct sched_entity *se)
722 {
723 return !!se->on_rq;
724 }
725 #endif
726
727 #ifdef CONFIG_SMP
728 /*
729 * XXX we want to get rid of these helpers and use the full load resolution.
730 */
731 static inline long se_weight(struct sched_entity *se)
732 {
733 return scale_load_down(se->load.weight);
734 }
735
736
737 static inline bool sched_asym_prefer(int a, int b)
738 {
739 return arch_asym_cpu_priority(a) > arch_asym_cpu_priority(b);
740 }
741
742 struct perf_domain {
743 struct em_perf_domain *em_pd;
744 struct perf_domain *next;
745 struct rcu_head rcu;
746 };
747
748 /* Scheduling group status flags */
749 #define SG_OVERLOAD 0x1 /* More than one runnable task on a CPU. */
750 #define SG_OVERUTILIZED 0x2 /* One or more CPUs are over-utilized. */
751
752 /*
753 * We add the notion of a root-domain which will be used to define per-domain
754 * variables. Each exclusive cpuset essentially defines an island domain by
755 * fully partitioning the member CPUs from any other cpuset. Whenever a new
756 * exclusive cpuset is created, we also create and attach a new root-domain
757 * object.
758 *
759 */
760 struct root_domain {
761 atomic_t refcount;
762 atomic_t rto_count;
763 struct rcu_head rcu;
764 cpumask_var_t span;
765 cpumask_var_t online;
766
767 /*
768 * Indicate pullable load on at least one CPU, e.g:
769 * - More than one runnable task
770 * - Running task is misfit
771 */
772 int overload;
773
774 /* Indicate one or more cpus over-utilized (tipping point) */
775 int overutilized;
776
777 /*
778 * The bit corresponding to a CPU gets set here if such CPU has more
779 * than one runnable -deadline task (as it is below for RT tasks).
780 */
781 cpumask_var_t dlo_mask;
782 atomic_t dlo_count;
783 struct dl_bw dl_bw;
784 struct cpudl cpudl;
785
786 #ifdef HAVE_RT_PUSH_IPI
787 /*
788 * For IPI pull requests, loop across the rto_mask.
789 */
790 struct irq_work rto_push_work;
791 raw_spinlock_t rto_lock;
792 /* These are only updated and read within rto_lock */
793 int rto_loop;
794 int rto_cpu;
795 /* These atomics are updated outside of a lock */
796 atomic_t rto_loop_next;
797 atomic_t rto_loop_start;
798 #endif
799 /*
800 * The "RT overload" flag: it gets set if a CPU has more than
801 * one runnable RT task.
802 */
803 cpumask_var_t rto_mask;
804 struct cpupri cpupri;
805
806 unsigned long max_cpu_capacity;
807
808 /*
809 * NULL-terminated list of performance domains intersecting with the
810 * CPUs of the rd. Protected by RCU.
811 */
812 struct perf_domain __rcu *pd;
813 };
814
815 extern void init_defrootdomain(void);
816 extern int sched_init_domains(const struct cpumask *cpu_map);
817 extern void rq_attach_root(struct rq *rq, struct root_domain *rd);
818 extern void sched_get_rd(struct root_domain *rd);
819 extern void sched_put_rd(struct root_domain *rd);
820
821 #ifdef HAVE_RT_PUSH_IPI
822 extern void rto_push_irq_work_func(struct irq_work *work);
823 #endif
824 #endif /* CONFIG_SMP */
825
826 #ifdef CONFIG_UCLAMP_TASK
827 /*
828 * struct uclamp_bucket - Utilization clamp bucket
829 * @value: utilization clamp value for tasks on this clamp bucket
830 * @tasks: number of RUNNABLE tasks on this clamp bucket
831 *
832 * Keep track of how many tasks are RUNNABLE for a given utilization
833 * clamp value.
834 */
835 struct uclamp_bucket {
836 unsigned long value : bits_per(SCHED_CAPACITY_SCALE);
837 unsigned long tasks : BITS_PER_LONG - bits_per(SCHED_CAPACITY_SCALE);
838 };
839
840 /*
841 * struct uclamp_rq - rq's utilization clamp
842 * @value: currently active clamp values for a rq
843 * @bucket: utilization clamp buckets affecting a rq
844 *
845 * Keep track of RUNNABLE tasks on a rq to aggregate their clamp values.
846 * A clamp value is affecting a rq when there is at least one task RUNNABLE
847 * (or actually running) with that value.
848 *
849 * There are up to UCLAMP_CNT possible different clamp values, currently there
850 * are only two: minimum utilization and maximum utilization.
851 *
852 * All utilization clamping values are MAX aggregated, since:
853 * - for util_min: we want to run the CPU at least at the max of the minimum
854 * utilization required by its currently RUNNABLE tasks.
855 * - for util_max: we want to allow the CPU to run up to the max of the
856 * maximum utilization allowed by its currently RUNNABLE tasks.
857 *
858 * Since on each system we expect only a limited number of different
859 * utilization clamp values (UCLAMP_BUCKETS), use a simple array to track
860 * the metrics required to compute all the per-rq utilization clamp values.
861 */
862 struct uclamp_rq {
863 unsigned int value;
864 struct uclamp_bucket bucket[UCLAMP_BUCKETS];
865 };
866 #endif /* CONFIG_UCLAMP_TASK */
867
868 /*
869 * This is the main, per-CPU runqueue data structure.
870 *
871 * Locking rule: those places that want to lock multiple runqueues
872 * (such as the load balancing or the thread migration code), lock
873 * acquire operations must be ordered by ascending &runqueue.
874 */
875 struct rq {
876 /* runqueue lock: */
877 raw_spinlock_t lock;
878
879 /*
880 * nr_running and cpu_load should be in the same cacheline because
881 * remote CPUs use both these fields when doing load calculation.
882 */
883 unsigned int nr_running;
884 #ifdef CONFIG_NUMA_BALANCING
885 unsigned int nr_numa_running;
886 unsigned int nr_preferred_running;
887 unsigned int numa_migrate_on;
888 #endif
889 #ifdef CONFIG_NO_HZ_COMMON
890 #ifdef CONFIG_SMP
891 unsigned long last_load_update_tick;
892 unsigned long last_blocked_load_update_tick;
893 unsigned int has_blocked_load;
894 #endif /* CONFIG_SMP */
895 unsigned int nohz_tick_stopped;
896 atomic_t nohz_flags;
897 #endif /* CONFIG_NO_HZ_COMMON */
898
899 unsigned long nr_load_updates;
900 u64 nr_switches;
901
902 #ifdef CONFIG_UCLAMP_TASK
903 /* Utilization clamp values based on CPU's RUNNABLE tasks */
904 struct uclamp_rq uclamp[UCLAMP_CNT] ____cacheline_aligned;
905 unsigned int uclamp_flags;
906 #define UCLAMP_FLAG_IDLE 0x01
907 #endif
908
909 struct cfs_rq cfs;
910 struct rt_rq rt;
911 struct dl_rq dl;
912
913 #ifdef CONFIG_FAIR_GROUP_SCHED
914 /* list of leaf cfs_rq on this CPU: */
915 struct list_head leaf_cfs_rq_list;
916 struct list_head *tmp_alone_branch;
917 #endif /* CONFIG_FAIR_GROUP_SCHED */
918
919 /*
920 * This is part of a global counter where only the total sum
921 * over all CPUs matters. A task can increase this counter on
922 * one CPU and if it got migrated afterwards it may decrease
923 * it on another CPU. Always updated under the runqueue lock:
924 */
925 unsigned long nr_uninterruptible;
926
927 struct task_struct __rcu *curr;
928 struct task_struct *idle;
929 struct task_struct *stop;
930 unsigned long next_balance;
931 struct mm_struct *prev_mm;
932
933 unsigned int clock_update_flags;
934 u64 clock;
935 /* Ensure that all clocks are in the same cache line */
936 u64 clock_task ____cacheline_aligned;
937 u64 clock_pelt;
938 unsigned long lost_idle_time;
939
940 atomic_t nr_iowait;
941
942 #ifdef CONFIG_MEMBARRIER
943 int membarrier_state;
944 #endif
945
946 #ifdef CONFIG_SMP
947 struct root_domain *rd;
948 struct sched_domain __rcu *sd;
949
950 unsigned long cpu_capacity;
951 unsigned long cpu_capacity_orig;
952
953 struct callback_head *balance_callback;
954
955 unsigned char idle_balance;
956
957 unsigned long misfit_task_load;
958
959 /* For active balancing */
960 int active_balance;
961 int push_cpu;
962 struct cpu_stop_work active_balance_work;
963
964 /* CPU of this runqueue: */
965 int cpu;
966 int online;
967
968 struct list_head cfs_tasks;
969
970 struct sched_avg avg_rt;
971 struct sched_avg avg_dl;
972 #ifdef CONFIG_HAVE_SCHED_AVG_IRQ
973 struct sched_avg avg_irq;
974 #endif
975 #ifdef CONFIG_SCHED_THERMAL_PRESSURE
976 struct sched_avg avg_thermal;
977 #endif
978 u64 idle_stamp;
979 u64 avg_idle;
980
981 /* This is used to determine avg_idle's max value */
982 u64 max_idle_balance_cost;
983 #endif
984
985 #ifdef CONFIG_IRQ_TIME_ACCOUNTING
986 u64 prev_irq_time;
987 #endif
988 #ifdef CONFIG_PARAVIRT
989 u64 prev_steal_time;
990 #endif
991 #ifdef CONFIG_PARAVIRT_TIME_ACCOUNTING
992 u64 prev_steal_time_rq;
993 #endif
994
995 /* calc_load related fields */
996 unsigned long calc_load_update;
997 long calc_load_active;
998
999 #ifdef CONFIG_SCHED_HRTICK
1000 #ifdef CONFIG_SMP
1001 call_single_data_t hrtick_csd;
1002 #endif
1003 struct hrtimer hrtick_timer;
1004 #endif
1005
1006 #ifdef CONFIG_SCHEDSTATS
1007 /* latency stats */
1008 struct sched_info rq_sched_info;
1009 unsigned long long rq_cpu_time;
1010 /* could above be rq->cfs_rq.exec_clock + rq->rt_rq.rt_runtime ? */
1011
1012 /* sys_sched_yield() stats */
1013 unsigned int yld_count;
1014
1015 /* schedule() stats */
1016 unsigned int sched_count;
1017 unsigned int sched_goidle;
1018
1019 /* try_to_wake_up() stats */
1020 unsigned int ttwu_count;
1021 unsigned int ttwu_local;
1022 #endif
1023
1024 #ifdef CONFIG_SMP
1025 struct llist_head wake_list;
1026 #endif
1027
1028 #ifdef CONFIG_CPU_IDLE
1029 /* Must be inspected within a rcu lock section */
1030 struct cpuidle_state *idle_state;
1031 #endif
1032 };
1033
1034 #ifdef CONFIG_FAIR_GROUP_SCHED
1035
1036 /* CPU runqueue to which this cfs_rq is attached */
1037 static inline struct rq *rq_of(struct cfs_rq *cfs_rq)
1038 {
1039 return cfs_rq->rq;
1040 }
1041
1042 #else
1043
1044 static inline struct rq *rq_of(struct cfs_rq *cfs_rq)
1045 {
1046 return container_of(cfs_rq, struct rq, cfs);
1047 }
1048 #endif
1049
1050 static inline int cpu_of(struct rq *rq)
1051 {
1052 #ifdef CONFIG_SMP
1053 return rq->cpu;
1054 #else
1055 return 0;
1056 #endif
1057 }
1058
1059
1060 #ifdef CONFIG_SCHED_SMT
1061 extern void __update_idle_core(struct rq *rq);
1062
1063 static inline void update_idle_core(struct rq *rq)
1064 {
1065 if (static_branch_unlikely(&sched_smt_present))
1066 __update_idle_core(rq);
1067 }
1068
1069 #else
1070 static inline void update_idle_core(struct rq *rq) { }
1071 #endif
1072
1073 DECLARE_PER_CPU_SHARED_ALIGNED(struct rq, runqueues);
1074
1075 #define cpu_rq(cpu) (&per_cpu(runqueues, (cpu)))
1076 #define this_rq() this_cpu_ptr(&runqueues)
1077 #define task_rq(p) cpu_rq(task_cpu(p))
1078 #define cpu_curr(cpu) (cpu_rq(cpu)->curr)
1079 #define raw_rq() raw_cpu_ptr(&runqueues)
1080
1081 extern void update_rq_clock(struct rq *rq);
1082
1083 static inline u64 __rq_clock_broken(struct rq *rq)
1084 {
1085 return READ_ONCE(rq->clock);
1086 }
1087
1088 /*
1089 * rq::clock_update_flags bits
1090 *
1091 * %RQCF_REQ_SKIP - will request skipping of clock update on the next
1092 * call to __schedule(). This is an optimisation to avoid
1093 * neighbouring rq clock updates.
1094 *
1095 * %RQCF_ACT_SKIP - is set from inside of __schedule() when skipping is
1096 * in effect and calls to update_rq_clock() are being ignored.
1097 *
1098 * %RQCF_UPDATED - is a debug flag that indicates whether a call has been
1099 * made to update_rq_clock() since the last time rq::lock was pinned.
1100 *
1101 * If inside of __schedule(), clock_update_flags will have been
1102 * shifted left (a left shift is a cheap operation for the fast path
1103 * to promote %RQCF_REQ_SKIP to %RQCF_ACT_SKIP), so you must use,
1104 *
1105 * if (rq-clock_update_flags >= RQCF_UPDATED)
1106 *
1107 * to check if %RQCF_UPADTED is set. It'll never be shifted more than
1108 * one position though, because the next rq_unpin_lock() will shift it
1109 * back.
1110 */
1111 #define RQCF_REQ_SKIP 0x01
1112 #define RQCF_ACT_SKIP 0x02
1113 #define RQCF_UPDATED 0x04
1114
1115 static inline void assert_clock_updated(struct rq *rq)
1116 {
1117 /*
1118 * The only reason for not seeing a clock update since the
1119 * last rq_pin_lock() is if we're currently skipping updates.
1120 */
1121 SCHED_WARN_ON(rq->clock_update_flags < RQCF_ACT_SKIP);
1122 }
1123
1124 static inline u64 rq_clock(struct rq *rq)
1125 {
1126 lockdep_assert_held(&rq->lock);
1127 assert_clock_updated(rq);
1128
1129 return rq->clock;
1130 }
1131
1132 static inline u64 rq_clock_task(struct rq *rq)
1133 {
1134 lockdep_assert_held(&rq->lock);
1135 assert_clock_updated(rq);
1136
1137 return rq->clock_task;
1138 }
1139
1140 /**
1141 * By default the decay is the default pelt decay period.
1142 * The decay shift can change the decay period in
1143 * multiples of 32.
1144 * Decay shift Decay period(ms)
1145 * 0 32
1146 * 1 64
1147 * 2 128
1148 * 3 256
1149 * 4 512
1150 */
1151 extern int sched_thermal_decay_shift;
1152
1153 static inline u64 rq_clock_thermal(struct rq *rq)
1154 {
1155 return rq_clock_task(rq) >> sched_thermal_decay_shift;
1156 }
1157
1158 static inline void rq_clock_skip_update(struct rq *rq)
1159 {
1160 lockdep_assert_held(&rq->lock);
1161 rq->clock_update_flags |= RQCF_REQ_SKIP;
1162 }
1163
1164 /*
1165 * See rt task throttling, which is the only time a skip
1166 * request is cancelled.
1167 */
1168 static inline void rq_clock_cancel_skipupdate(struct rq *rq)
1169 {
1170 lockdep_assert_held(&rq->lock);
1171 rq->clock_update_flags &= ~RQCF_REQ_SKIP;
1172 }
1173
1174 struct rq_flags {
1175 unsigned long flags;
1176 struct pin_cookie cookie;
1177 #ifdef CONFIG_SCHED_DEBUG
1178 /*
1179 * A copy of (rq::clock_update_flags & RQCF_UPDATED) for the
1180 * current pin context is stashed here in case it needs to be
1181 * restored in rq_repin_lock().
1182 */
1183 unsigned int clock_update_flags;
1184 #endif
1185 };
1186
1187 static inline void rq_pin_lock(struct rq *rq, struct rq_flags *rf)
1188 {
1189 rf->cookie = lockdep_pin_lock(&rq->lock);
1190
1191 #ifdef CONFIG_SCHED_DEBUG
1192 rq->clock_update_flags &= (RQCF_REQ_SKIP|RQCF_ACT_SKIP);
1193 rf->clock_update_flags = 0;
1194 #endif
1195 }
1196
1197 static inline void rq_unpin_lock(struct rq *rq, struct rq_flags *rf)
1198 {
1199 #ifdef CONFIG_SCHED_DEBUG
1200 if (rq->clock_update_flags > RQCF_ACT_SKIP)
1201 rf->clock_update_flags = RQCF_UPDATED;
1202 #endif
1203
1204 lockdep_unpin_lock(&rq->lock, rf->cookie);
1205 }
1206
1207 static inline void rq_repin_lock(struct rq *rq, struct rq_flags *rf)
1208 {
1209 lockdep_repin_lock(&rq->lock, rf->cookie);
1210
1211 #ifdef CONFIG_SCHED_DEBUG
1212 /*
1213 * Restore the value we stashed in @rf for this pin context.
1214 */
1215 rq->clock_update_flags |= rf->clock_update_flags;
1216 #endif
1217 }
1218
1219 struct rq *__task_rq_lock(struct task_struct *p, struct rq_flags *rf)
1220 __acquires(rq->lock);
1221
1222 struct rq *task_rq_lock(struct task_struct *p, struct rq_flags *rf)
1223 __acquires(p->pi_lock)
1224 __acquires(rq->lock);
1225
1226 static inline void __task_rq_unlock(struct rq *rq, struct rq_flags *rf)
1227 __releases(rq->lock)
1228 {
1229 rq_unpin_lock(rq, rf);
1230 raw_spin_unlock(&rq->lock);
1231 }
1232
1233 static inline void
1234 task_rq_unlock(struct rq *rq, struct task_struct *p, struct rq_flags *rf)
1235 __releases(rq->lock)
1236 __releases(p->pi_lock)
1237 {
1238 rq_unpin_lock(rq, rf);
1239 raw_spin_unlock(&rq->lock);
1240 raw_spin_unlock_irqrestore(&p->pi_lock, rf->flags);
1241 }
1242
1243 static inline void
1244 rq_lock_irqsave(struct rq *rq, struct rq_flags *rf)
1245 __acquires(rq->lock)
1246 {
1247 raw_spin_lock_irqsave(&rq->lock, rf->flags);
1248 rq_pin_lock(rq, rf);
1249 }
1250
1251 static inline void
1252 rq_lock_irq(struct rq *rq, struct rq_flags *rf)
1253 __acquires(rq->lock)
1254 {
1255 raw_spin_lock_irq(&rq->lock);
1256 rq_pin_lock(rq, rf);
1257 }
1258
1259 static inline void
1260 rq_lock(struct rq *rq, struct rq_flags *rf)
1261 __acquires(rq->lock)
1262 {
1263 raw_spin_lock(&rq->lock);
1264 rq_pin_lock(rq, rf);
1265 }
1266
1267 static inline void
1268 rq_relock(struct rq *rq, struct rq_flags *rf)
1269 __acquires(rq->lock)
1270 {
1271 raw_spin_lock(&rq->lock);
1272 rq_repin_lock(rq, rf);
1273 }
1274
1275 static inline void
1276 rq_unlock_irqrestore(struct rq *rq, struct rq_flags *rf)
1277 __releases(rq->lock)
1278 {
1279 rq_unpin_lock(rq, rf);
1280 raw_spin_unlock_irqrestore(&rq->lock, rf->flags);
1281 }
1282
1283 static inline void
1284 rq_unlock_irq(struct rq *rq, struct rq_flags *rf)
1285 __releases(rq->lock)
1286 {
1287 rq_unpin_lock(rq, rf);
1288 raw_spin_unlock_irq(&rq->lock);
1289 }
1290
1291 static inline void
1292 rq_unlock(struct rq *rq, struct rq_flags *rf)
1293 __releases(rq->lock)
1294 {
1295 rq_unpin_lock(rq, rf);
1296 raw_spin_unlock(&rq->lock);
1297 }
1298
1299 static inline struct rq *
1300 this_rq_lock_irq(struct rq_flags *rf)
1301 __acquires(rq->lock)
1302 {
1303 struct rq *rq;
1304
1305 local_irq_disable();
1306 rq = this_rq();
1307 rq_lock(rq, rf);
1308 return rq;
1309 }
1310
1311 #ifdef CONFIG_NUMA
1312 enum numa_topology_type {
1313 NUMA_DIRECT,
1314 NUMA_GLUELESS_MESH,
1315 NUMA_BACKPLANE,
1316 };
1317 extern enum numa_topology_type sched_numa_topology_type;
1318 extern int sched_max_numa_distance;
1319 extern bool find_numa_distance(int distance);
1320 extern void sched_init_numa(void);
1321 extern void sched_domains_numa_masks_set(unsigned int cpu);
1322 extern void sched_domains_numa_masks_clear(unsigned int cpu);
1323 extern int sched_numa_find_closest(const struct cpumask *cpus, int cpu);
1324 #else
1325 static inline void sched_init_numa(void) { }
1326 static inline void sched_domains_numa_masks_set(unsigned int cpu) { }
1327 static inline void sched_domains_numa_masks_clear(unsigned int cpu) { }
1328 static inline int sched_numa_find_closest(const struct cpumask *cpus, int cpu)
1329 {
1330 return nr_cpu_ids;
1331 }
1332 #endif
1333
1334 #ifdef CONFIG_NUMA_BALANCING
1335 /* The regions in numa_faults array from task_struct */
1336 enum numa_faults_stats {
1337 NUMA_MEM = 0,
1338 NUMA_CPU,
1339 NUMA_MEMBUF,
1340 NUMA_CPUBUF
1341 };
1342 extern void sched_setnuma(struct task_struct *p, int node);
1343 extern int migrate_task_to(struct task_struct *p, int cpu);
1344 extern int migrate_swap(struct task_struct *p, struct task_struct *t,
1345 int cpu, int scpu);
1346 extern void init_numa_balancing(unsigned long clone_flags, struct task_struct *p);
1347 #else
1348 static inline void
1349 init_numa_balancing(unsigned long clone_flags, struct task_struct *p)
1350 {
1351 }
1352 #endif /* CONFIG_NUMA_BALANCING */
1353
1354 #ifdef CONFIG_SMP
1355
1356 static inline void
1357 queue_balance_callback(struct rq *rq,
1358 struct callback_head *head,
1359 void (*func)(struct rq *rq))
1360 {
1361 lockdep_assert_held(&rq->lock);
1362
1363 if (unlikely(head->next))
1364 return;
1365
1366 head->func = (void (*)(struct callback_head *))func;
1367 head->next = rq->balance_callback;
1368 rq->balance_callback = head;
1369 }
1370
1371 extern void sched_ttwu_pending(void);
1372
1373 #define rcu_dereference_check_sched_domain(p) \
1374 rcu_dereference_check((p), \
1375 lockdep_is_held(&sched_domains_mutex))
1376
1377 /*
1378 * The domain tree (rq->sd) is protected by RCU's quiescent state transition.
1379 * See destroy_sched_domains: call_rcu for details.
1380 *
1381 * The domain tree of any CPU may only be accessed from within
1382 * preempt-disabled sections.
1383 */
1384 #define for_each_domain(cpu, __sd) \
1385 for (__sd = rcu_dereference_check_sched_domain(cpu_rq(cpu)->sd); \
1386 __sd; __sd = __sd->parent)
1387
1388 /**
1389 * highest_flag_domain - Return highest sched_domain containing flag.
1390 * @cpu: The CPU whose highest level of sched domain is to
1391 * be returned.
1392 * @flag: The flag to check for the highest sched_domain
1393 * for the given CPU.
1394 *
1395 * Returns the highest sched_domain of a CPU which contains the given flag.
1396 */
1397 static inline struct sched_domain *highest_flag_domain(int cpu, int flag)
1398 {
1399 struct sched_domain *sd, *hsd = NULL;
1400
1401 for_each_domain(cpu, sd) {
1402 if (!(sd->flags & flag))
1403 break;
1404 hsd = sd;
1405 }
1406
1407 return hsd;
1408 }
1409
1410 static inline struct sched_domain *lowest_flag_domain(int cpu, int flag)
1411 {
1412 struct sched_domain *sd;
1413
1414 for_each_domain(cpu, sd) {
1415 if (sd->flags & flag)
1416 break;
1417 }
1418
1419 return sd;
1420 }
1421
1422 DECLARE_PER_CPU(struct sched_domain __rcu *, sd_llc);
1423 DECLARE_PER_CPU(int, sd_llc_size);
1424 DECLARE_PER_CPU(int, sd_llc_id);
1425 DECLARE_PER_CPU(struct sched_domain_shared __rcu *, sd_llc_shared);
1426 DECLARE_PER_CPU(struct sched_domain __rcu *, sd_numa);
1427 DECLARE_PER_CPU(struct sched_domain __rcu *, sd_asym_packing);
1428 DECLARE_PER_CPU(struct sched_domain __rcu *, sd_asym_cpucapacity);
1429 extern struct static_key_false sched_asym_cpucapacity;
1430
1431 struct sched_group_capacity {
1432 atomic_t ref;
1433 /*
1434 * CPU capacity of this group, SCHED_CAPACITY_SCALE being max capacity
1435 * for a single CPU.
1436 */
1437 unsigned long capacity;
1438 unsigned long min_capacity; /* Min per-CPU capacity in group */
1439 unsigned long max_capacity; /* Max per-CPU capacity in group */
1440 unsigned long next_update;
1441 int imbalance; /* XXX unrelated to capacity but shared group state */
1442
1443 #ifdef CONFIG_SCHED_DEBUG
1444 int id;
1445 #endif
1446
1447 unsigned long cpumask[0]; /* Balance mask */
1448 };
1449
1450 struct sched_group {
1451 struct sched_group *next; /* Must be a circular list */
1452 atomic_t ref;
1453
1454 unsigned int group_weight;
1455 struct sched_group_capacity *sgc;
1456 int asym_prefer_cpu; /* CPU of highest priority in group */
1457
1458 /*
1459 * The CPUs this group covers.
1460 *
1461 * NOTE: this field is variable length. (Allocated dynamically
1462 * by attaching extra space to the end of the structure,
1463 * depending on how many CPUs the kernel has booted up with)
1464 */
1465 unsigned long cpumask[0];
1466 };
1467
1468 static inline struct cpumask *sched_group_span(struct sched_group *sg)
1469 {
1470 return to_cpumask(sg->cpumask);
1471 }
1472
1473 /*
1474 * See build_balance_mask().
1475 */
1476 static inline struct cpumask *group_balance_mask(struct sched_group *sg)
1477 {
1478 return to_cpumask(sg->sgc->cpumask);
1479 }
1480
1481 /**
1482 * group_first_cpu - Returns the first CPU in the cpumask of a sched_group.
1483 * @group: The group whose first CPU is to be returned.
1484 */
1485 static inline unsigned int group_first_cpu(struct sched_group *group)
1486 {
1487 return cpumask_first(sched_group_span(group));
1488 }
1489
1490 extern int group_balance_cpu(struct sched_group *sg);
1491
1492 #if defined(CONFIG_SCHED_DEBUG) && defined(CONFIG_SYSCTL)
1493 void register_sched_domain_sysctl(void);
1494 void dirty_sched_domain_sysctl(int cpu);
1495 void unregister_sched_domain_sysctl(void);
1496 #else
1497 static inline void register_sched_domain_sysctl(void)
1498 {
1499 }
1500 static inline void dirty_sched_domain_sysctl(int cpu)
1501 {
1502 }
1503 static inline void unregister_sched_domain_sysctl(void)
1504 {
1505 }
1506 #endif
1507
1508 extern int newidle_balance(struct rq *this_rq, struct rq_flags *rf);
1509
1510 #else
1511
1512 static inline void sched_ttwu_pending(void) { }
1513
1514 static inline int newidle_balance(struct rq *this_rq, struct rq_flags *rf) { return 0; }
1515
1516 #endif /* CONFIG_SMP */
1517
1518 #include "stats.h"
1519 #include "autogroup.h"
1520
1521 #ifdef CONFIG_CGROUP_SCHED
1522
1523 /*
1524 * Return the group to which this tasks belongs.
1525 *
1526 * We cannot use task_css() and friends because the cgroup subsystem
1527 * changes that value before the cgroup_subsys::attach() method is called,
1528 * therefore we cannot pin it and might observe the wrong value.
1529 *
1530 * The same is true for autogroup's p->signal->autogroup->tg, the autogroup
1531 * core changes this before calling sched_move_task().
1532 *
1533 * Instead we use a 'copy' which is updated from sched_move_task() while
1534 * holding both task_struct::pi_lock and rq::lock.
1535 */
1536 static inline struct task_group *task_group(struct task_struct *p)
1537 {
1538 return p->sched_task_group;
1539 }
1540
1541 /* Change a task's cfs_rq and parent entity if it moves across CPUs/groups */
1542 static inline void set_task_rq(struct task_struct *p, unsigned int cpu)
1543 {
1544 #if defined(CONFIG_FAIR_GROUP_SCHED) || defined(CONFIG_RT_GROUP_SCHED)
1545 struct task_group *tg = task_group(p);
1546 #endif
1547
1548 #ifdef CONFIG_FAIR_GROUP_SCHED
1549 set_task_rq_fair(&p->se, p->se.cfs_rq, tg->cfs_rq[cpu]);
1550 p->se.cfs_rq = tg->cfs_rq[cpu];
1551 p->se.parent = tg->se[cpu];
1552 #endif
1553
1554 #ifdef CONFIG_RT_GROUP_SCHED
1555 p->rt.rt_rq = tg->rt_rq[cpu];
1556 p->rt.parent = tg->rt_se[cpu];
1557 #endif
1558 }
1559
1560 #else /* CONFIG_CGROUP_SCHED */
1561
1562 static inline void set_task_rq(struct task_struct *p, unsigned int cpu) { }
1563 static inline struct task_group *task_group(struct task_struct *p)
1564 {
1565 return NULL;
1566 }
1567
1568 #endif /* CONFIG_CGROUP_SCHED */
1569
1570 static inline void __set_task_cpu(struct task_struct *p, unsigned int cpu)
1571 {
1572 set_task_rq(p, cpu);
1573 #ifdef CONFIG_SMP
1574 /*
1575 * After ->cpu is set up to a new value, task_rq_lock(p, ...) can be
1576 * successfully executed on another CPU. We must ensure that updates of
1577 * per-task data have been completed by this moment.
1578 */
1579 smp_wmb();
1580 #ifdef CONFIG_THREAD_INFO_IN_TASK
1581 WRITE_ONCE(p->cpu, cpu);
1582 #else
1583 WRITE_ONCE(task_thread_info(p)->cpu, cpu);
1584 #endif
1585 p->wake_cpu = cpu;
1586 #endif
1587 }
1588
1589 /*
1590 * Tunables that become constants when CONFIG_SCHED_DEBUG is off:
1591 */
1592 #ifdef CONFIG_SCHED_DEBUG
1593 # include <linux/static_key.h>
1594 # define const_debug __read_mostly
1595 #else
1596 # define const_debug const
1597 #endif
1598
1599 #define SCHED_FEAT(name, enabled) \
1600 __SCHED_FEAT_##name ,
1601
1602 enum {
1603 #include "features.h"
1604 __SCHED_FEAT_NR,
1605 };
1606
1607 #undef SCHED_FEAT
1608
1609 #if defined(CONFIG_SCHED_DEBUG) && defined(CONFIG_JUMP_LABEL)
1610
1611 /*
1612 * To support run-time toggling of sched features, all the translation units
1613 * (but core.c) reference the sysctl_sched_features defined in core.c.
1614 */
1615 extern const_debug unsigned int sysctl_sched_features;
1616
1617 #define SCHED_FEAT(name, enabled) \
1618 static __always_inline bool static_branch_##name(struct static_key *key) \
1619 { \
1620 return static_key_##enabled(key); \
1621 }
1622
1623 #include "features.h"
1624 #undef SCHED_FEAT
1625
1626 extern struct static_key sched_feat_keys[__SCHED_FEAT_NR];
1627 #define sched_feat(x) (static_branch_##x(&sched_feat_keys[__SCHED_FEAT_##x]))
1628
1629 #else /* !(SCHED_DEBUG && CONFIG_JUMP_LABEL) */
1630
1631 /*
1632 * Each translation unit has its own copy of sysctl_sched_features to allow
1633 * constants propagation at compile time and compiler optimization based on
1634 * features default.
1635 */
1636 #define SCHED_FEAT(name, enabled) \
1637 (1UL << __SCHED_FEAT_##name) * enabled |
1638 static const_debug __maybe_unused unsigned int sysctl_sched_features =
1639 #include "features.h"
1640 0;
1641 #undef SCHED_FEAT
1642
1643 #define sched_feat(x) !!(sysctl_sched_features & (1UL << __SCHED_FEAT_##x))
1644
1645 #endif /* SCHED_DEBUG && CONFIG_JUMP_LABEL */
1646
1647 extern struct static_key_false sched_numa_balancing;
1648 extern struct static_key_false sched_schedstats;
1649
1650 static inline u64 global_rt_period(void)
1651 {
1652 return (u64)sysctl_sched_rt_period * NSEC_PER_USEC;
1653 }
1654
1655 static inline u64 global_rt_runtime(void)
1656 {
1657 if (sysctl_sched_rt_runtime < 0)
1658 return RUNTIME_INF;
1659
1660 return (u64)sysctl_sched_rt_runtime * NSEC_PER_USEC;
1661 }
1662
1663 static inline int task_current(struct rq *rq, struct task_struct *p)
1664 {
1665 return rq->curr == p;
1666 }
1667
1668 static inline int task_running(struct rq *rq, struct task_struct *p)
1669 {
1670 #ifdef CONFIG_SMP
1671 return p->on_cpu;
1672 #else
1673 return task_current(rq, p);
1674 #endif
1675 }
1676
1677 static inline int task_on_rq_queued(struct task_struct *p)
1678 {
1679 return p->on_rq == TASK_ON_RQ_QUEUED;
1680 }
1681
1682 static inline int task_on_rq_migrating(struct task_struct *p)
1683 {
1684 return READ_ONCE(p->on_rq) == TASK_ON_RQ_MIGRATING;
1685 }
1686
1687 /*
1688 * wake flags
1689 */
1690 #define WF_SYNC 0x01 /* Waker goes to sleep after wakeup */
1691 #define WF_FORK 0x02 /* Child wakeup after fork */
1692 #define WF_MIGRATED 0x4 /* Internal use, task got migrated */
1693
1694 /*
1695 * To aid in avoiding the subversion of "niceness" due to uneven distribution
1696 * of tasks with abnormal "nice" values across CPUs the contribution that
1697 * each task makes to its run queue's load is weighted according to its
1698 * scheduling class and "nice" value. For SCHED_NORMAL tasks this is just a
1699 * scaled version of the new time slice allocation that they receive on time
1700 * slice expiry etc.
1701 */
1702
1703 #define WEIGHT_IDLEPRIO 3
1704 #define WMULT_IDLEPRIO 1431655765
1705
1706 extern const int sched_prio_to_weight[40];
1707 extern const u32 sched_prio_to_wmult[40];
1708
1709 /*
1710 * {de,en}queue flags:
1711 *
1712 * DEQUEUE_SLEEP - task is no longer runnable
1713 * ENQUEUE_WAKEUP - task just became runnable
1714 *
1715 * SAVE/RESTORE - an otherwise spurious dequeue/enqueue, done to ensure tasks
1716 * are in a known state which allows modification. Such pairs
1717 * should preserve as much state as possible.
1718 *
1719 * MOVE - paired with SAVE/RESTORE, explicitly does not preserve the location
1720 * in the runqueue.
1721 *
1722 * ENQUEUE_HEAD - place at front of runqueue (tail if not specified)
1723 * ENQUEUE_REPLENISH - CBS (replenish runtime and postpone deadline)
1724 * ENQUEUE_MIGRATED - the task was migrated during wakeup
1725 *
1726 */
1727
1728 #define DEQUEUE_SLEEP 0x01
1729 #define DEQUEUE_SAVE 0x02 /* Matches ENQUEUE_RESTORE */
1730 #define DEQUEUE_MOVE 0x04 /* Matches ENQUEUE_MOVE */
1731 #define DEQUEUE_NOCLOCK 0x08 /* Matches ENQUEUE_NOCLOCK */
1732
1733 #define ENQUEUE_WAKEUP 0x01
1734 #define ENQUEUE_RESTORE 0x02
1735 #define ENQUEUE_MOVE 0x04
1736 #define ENQUEUE_NOCLOCK 0x08
1737
1738 #define ENQUEUE_HEAD 0x10
1739 #define ENQUEUE_REPLENISH 0x20
1740 #ifdef CONFIG_SMP
1741 #define ENQUEUE_MIGRATED 0x40
1742 #else
1743 #define ENQUEUE_MIGRATED 0x00
1744 #endif
1745
1746 #define RETRY_TASK ((void *)-1UL)
1747
1748 struct sched_class {
1749 const struct sched_class *next;
1750
1751 #ifdef CONFIG_UCLAMP_TASK
1752 int uclamp_enabled;
1753 #endif
1754
1755 void (*enqueue_task) (struct rq *rq, struct task_struct *p, int flags);
1756 void (*dequeue_task) (struct rq *rq, struct task_struct *p, int flags);
1757 void (*yield_task) (struct rq *rq);
1758 bool (*yield_to_task)(struct rq *rq, struct task_struct *p, bool preempt);
1759
1760 void (*check_preempt_curr)(struct rq *rq, struct task_struct *p, int flags);
1761
1762 struct task_struct *(*pick_next_task)(struct rq *rq);
1763
1764 void (*put_prev_task)(struct rq *rq, struct task_struct *p);
1765 void (*set_next_task)(struct rq *rq, struct task_struct *p, bool first);
1766
1767 #ifdef CONFIG_SMP
1768 int (*balance)(struct rq *rq, struct task_struct *prev, struct rq_flags *rf);
1769 int (*select_task_rq)(struct task_struct *p, int task_cpu, int sd_flag, int flags);
1770 void (*migrate_task_rq)(struct task_struct *p, int new_cpu);
1771
1772 void (*task_woken)(struct rq *this_rq, struct task_struct *task);
1773
1774 void (*set_cpus_allowed)(struct task_struct *p,
1775 const struct cpumask *newmask);
1776
1777 void (*rq_online)(struct rq *rq);
1778 void (*rq_offline)(struct rq *rq);
1779 #endif
1780
1781 void (*task_tick)(struct rq *rq, struct task_struct *p, int queued);
1782 void (*task_fork)(struct task_struct *p);
1783 void (*task_dead)(struct task_struct *p);
1784
1785 /*
1786 * The switched_from() call is allowed to drop rq->lock, therefore we
1787 * cannot assume the switched_from/switched_to pair is serliazed by
1788 * rq->lock. They are however serialized by p->pi_lock.
1789 */
1790 void (*switched_from)(struct rq *this_rq, struct task_struct *task);
1791 void (*switched_to) (struct rq *this_rq, struct task_struct *task);
1792 void (*prio_changed) (struct rq *this_rq, struct task_struct *task,
1793 int oldprio);
1794
1795 unsigned int (*get_rr_interval)(struct rq *rq,
1796 struct task_struct *task);
1797
1798 void (*update_curr)(struct rq *rq);
1799
1800 #define TASK_SET_GROUP 0
1801 #define TASK_MOVE_GROUP 1
1802
1803 #ifdef CONFIG_FAIR_GROUP_SCHED
1804 void (*task_change_group)(struct task_struct *p, int type);
1805 #endif
1806 };
1807
1808 static inline void put_prev_task(struct rq *rq, struct task_struct *prev)
1809 {
1810 WARN_ON_ONCE(rq->curr != prev);
1811 prev->sched_class->put_prev_task(rq, prev);
1812 }
1813
1814 static inline void set_next_task(struct rq *rq, struct task_struct *next)
1815 {
1816 WARN_ON_ONCE(rq->curr != next);
1817 next->sched_class->set_next_task(rq, next, false);
1818 }
1819
1820 #ifdef CONFIG_SMP
1821 #define sched_class_highest (&stop_sched_class)
1822 #else
1823 #define sched_class_highest (&dl_sched_class)
1824 #endif
1825
1826 #define for_class_range(class, _from, _to) \
1827 for (class = (_from); class != (_to); class = class->next)
1828
1829 #define for_each_class(class) \
1830 for_class_range(class, sched_class_highest, NULL)
1831
1832 extern const struct sched_class stop_sched_class;
1833 extern const struct sched_class dl_sched_class;
1834 extern const struct sched_class rt_sched_class;
1835 extern const struct sched_class fair_sched_class;
1836 extern const struct sched_class idle_sched_class;
1837
1838 static inline bool sched_stop_runnable(struct rq *rq)
1839 {
1840 return rq->stop && task_on_rq_queued(rq->stop);
1841 }
1842
1843 static inline bool sched_dl_runnable(struct rq *rq)
1844 {
1845 return rq->dl.dl_nr_running > 0;
1846 }
1847
1848 static inline bool sched_rt_runnable(struct rq *rq)
1849 {
1850 return rq->rt.rt_queued > 0;
1851 }
1852
1853 static inline bool sched_fair_runnable(struct rq *rq)
1854 {
1855 return rq->cfs.nr_running > 0;
1856 }
1857
1858 extern struct task_struct *pick_next_task_fair(struct rq *rq, struct task_struct *prev, struct rq_flags *rf);
1859 extern struct task_struct *pick_next_task_idle(struct rq *rq);
1860
1861 #ifdef CONFIG_SMP
1862
1863 extern void update_group_capacity(struct sched_domain *sd, int cpu);
1864
1865 extern void trigger_load_balance(struct rq *rq);
1866
1867 extern void set_cpus_allowed_common(struct task_struct *p, const struct cpumask *new_mask);
1868
1869 #endif
1870
1871 #ifdef CONFIG_CPU_IDLE
1872 static inline void idle_set_state(struct rq *rq,
1873 struct cpuidle_state *idle_state)
1874 {
1875 rq->idle_state = idle_state;
1876 }
1877
1878 static inline struct cpuidle_state *idle_get_state(struct rq *rq)
1879 {
1880 SCHED_WARN_ON(!rcu_read_lock_held());
1881
1882 return rq->idle_state;
1883 }
1884 #else
1885 static inline void idle_set_state(struct rq *rq,
1886 struct cpuidle_state *idle_state)
1887 {
1888 }
1889
1890 static inline struct cpuidle_state *idle_get_state(struct rq *rq)
1891 {
1892 return NULL;
1893 }
1894 #endif
1895
1896 extern void schedule_idle(void);
1897
1898 extern void sysrq_sched_debug_show(void);
1899 extern void sched_init_granularity(void);
1900 extern void update_max_interval(void);
1901
1902 extern void init_sched_dl_class(void);
1903 extern void init_sched_rt_class(void);
1904 extern void init_sched_fair_class(void);
1905
1906 extern void reweight_task(struct task_struct *p, int prio);
1907
1908 extern void resched_curr(struct rq *rq);
1909 extern void resched_cpu(int cpu);
1910
1911 extern struct rt_bandwidth def_rt_bandwidth;
1912 extern void init_rt_bandwidth(struct rt_bandwidth *rt_b, u64 period, u64 runtime);
1913
1914 extern struct dl_bandwidth def_dl_bandwidth;
1915 extern void init_dl_bandwidth(struct dl_bandwidth *dl_b, u64 period, u64 runtime);
1916 extern void init_dl_task_timer(struct sched_dl_entity *dl_se);
1917 extern void init_dl_inactive_task_timer(struct sched_dl_entity *dl_se);
1918
1919 #define BW_SHIFT 20
1920 #define BW_UNIT (1 << BW_SHIFT)
1921 #define RATIO_SHIFT 8
1922 unsigned long to_ratio(u64 period, u64 runtime);
1923
1924 extern void init_entity_runnable_average(struct sched_entity *se);
1925 extern void post_init_entity_util_avg(struct task_struct *p);
1926
1927 #ifdef CONFIG_NO_HZ_FULL
1928 extern bool sched_can_stop_tick(struct rq *rq);
1929 extern int __init sched_tick_offload_init(void);
1930
1931 /*
1932 * Tick may be needed by tasks in the runqueue depending on their policy and
1933 * requirements. If tick is needed, lets send the target an IPI to kick it out of
1934 * nohz mode if necessary.
1935 */
1936 static inline void sched_update_tick_dependency(struct rq *rq)
1937 {
1938 int cpu;
1939
1940 if (!tick_nohz_full_enabled())
1941 return;
1942
1943 cpu = cpu_of(rq);
1944
1945 if (!tick_nohz_full_cpu(cpu))
1946 return;
1947
1948 if (sched_can_stop_tick(rq))
1949 tick_nohz_dep_clear_cpu(cpu, TICK_DEP_BIT_SCHED);
1950 else
1951 tick_nohz_dep_set_cpu(cpu, TICK_DEP_BIT_SCHED);
1952 }
1953 #else
1954 static inline int sched_tick_offload_init(void) { return 0; }
1955 static inline void sched_update_tick_dependency(struct rq *rq) { }
1956 #endif
1957
1958 static inline void add_nr_running(struct rq *rq, unsigned count)
1959 {
1960 unsigned prev_nr = rq->nr_running;
1961
1962 rq->nr_running = prev_nr + count;
1963
1964 #ifdef CONFIG_SMP
1965 if (prev_nr < 2 && rq->nr_running >= 2) {
1966 if (!READ_ONCE(rq->rd->overload))
1967 WRITE_ONCE(rq->rd->overload, 1);
1968 }
1969 #endif
1970
1971 sched_update_tick_dependency(rq);
1972 }
1973
1974 static inline void sub_nr_running(struct rq *rq, unsigned count)
1975 {
1976 rq->nr_running -= count;
1977 /* Check if we still need preemption */
1978 sched_update_tick_dependency(rq);
1979 }
1980
1981 extern void activate_task(struct rq *rq, struct task_struct *p, int flags);
1982 extern void deactivate_task(struct rq *rq, struct task_struct *p, int flags);
1983
1984 extern void check_preempt_curr(struct rq *rq, struct task_struct *p, int flags);
1985
1986 extern const_debug unsigned int sysctl_sched_nr_migrate;
1987 extern const_debug unsigned int sysctl_sched_migration_cost;
1988
1989 #ifdef CONFIG_SCHED_HRTICK
1990
1991 /*
1992 * Use hrtick when:
1993 * - enabled by features
1994 * - hrtimer is actually high res
1995 */
1996 static inline int hrtick_enabled(struct rq *rq)
1997 {
1998 if (!sched_feat(HRTICK))
1999 return 0;
2000 if (!cpu_active(cpu_of(rq)))
2001 return 0;
2002 return hrtimer_is_hres_active(&rq->hrtick_timer);
2003 }
2004
2005 void hrtick_start(struct rq *rq, u64 delay);
2006
2007 #else
2008
2009 static inline int hrtick_enabled(struct rq *rq)
2010 {
2011 return 0;
2012 }
2013
2014 #endif /* CONFIG_SCHED_HRTICK */
2015
2016 #ifndef arch_scale_freq_tick
2017 static __always_inline
2018 void arch_scale_freq_tick(void)
2019 {
2020 }
2021 #endif
2022
2023 #ifndef arch_scale_freq_capacity
2024 static __always_inline
2025 unsigned long arch_scale_freq_capacity(int cpu)
2026 {
2027 return SCHED_CAPACITY_SCALE;
2028 }
2029 #endif
2030
2031 #ifdef CONFIG_SMP
2032 #ifdef CONFIG_PREEMPTION
2033
2034 static inline void double_rq_lock(struct rq *rq1, struct rq *rq2);
2035
2036 /*
2037 * fair double_lock_balance: Safely acquires both rq->locks in a fair
2038 * way at the expense of forcing extra atomic operations in all
2039 * invocations. This assures that the double_lock is acquired using the
2040 * same underlying policy as the spinlock_t on this architecture, which
2041 * reduces latency compared to the unfair variant below. However, it
2042 * also adds more overhead and therefore may reduce throughput.
2043 */
2044 static inline int _double_lock_balance(struct rq *this_rq, struct rq *busiest)
2045 __releases(this_rq->lock)
2046 __acquires(busiest->lock)
2047 __acquires(this_rq->lock)
2048 {
2049 raw_spin_unlock(&this_rq->lock);
2050 double_rq_lock(this_rq, busiest);
2051
2052 return 1;
2053 }
2054
2055 #else
2056 /*
2057 * Unfair double_lock_balance: Optimizes throughput at the expense of
2058 * latency by eliminating extra atomic operations when the locks are
2059 * already in proper order on entry. This favors lower CPU-ids and will
2060 * grant the double lock to lower CPUs over higher ids under contention,
2061 * regardless of entry order into the function.
2062 */
2063 static inline int _double_lock_balance(struct rq *this_rq, struct rq *busiest)
2064 __releases(this_rq->lock)
2065 __acquires(busiest->lock)
2066 __acquires(this_rq->lock)
2067 {
2068 int ret = 0;
2069
2070 if (unlikely(!raw_spin_trylock(&busiest->lock))) {
2071 if (busiest < this_rq) {
2072 raw_spin_unlock(&this_rq->lock);
2073 raw_spin_lock(&busiest->lock);
2074 raw_spin_lock_nested(&this_rq->lock,
2075 SINGLE_DEPTH_NESTING);
2076 ret = 1;
2077 } else
2078 raw_spin_lock_nested(&busiest->lock,
2079 SINGLE_DEPTH_NESTING);
2080 }
2081 return ret;
2082 }
2083
2084 #endif /* CONFIG_PREEMPTION */
2085
2086 /*
2087 * double_lock_balance - lock the busiest runqueue, this_rq is locked already.
2088 */
2089 static inline int double_lock_balance(struct rq *this_rq, struct rq *busiest)
2090 {
2091 if (unlikely(!irqs_disabled())) {
2092 /* printk() doesn't work well under rq->lock */
2093 raw_spin_unlock(&this_rq->lock);
2094 BUG_ON(1);
2095 }
2096
2097 return _double_lock_balance(this_rq, busiest);
2098 }
2099
2100 static inline void double_unlock_balance(struct rq *this_rq, struct rq *busiest)
2101 __releases(busiest->lock)
2102 {
2103 raw_spin_unlock(&busiest->lock);
2104 lock_set_subclass(&this_rq->lock.dep_map, 0, _RET_IP_);
2105 }
2106
2107 static inline void double_lock(spinlock_t *l1, spinlock_t *l2)
2108 {
2109 if (l1 > l2)
2110 swap(l1, l2);
2111
2112 spin_lock(l1);
2113 spin_lock_nested(l2, SINGLE_DEPTH_NESTING);
2114 }
2115
2116 static inline void double_lock_irq(spinlock_t *l1, spinlock_t *l2)
2117 {
2118 if (l1 > l2)
2119 swap(l1, l2);
2120
2121 spin_lock_irq(l1);
2122 spin_lock_nested(l2, SINGLE_DEPTH_NESTING);
2123 }
2124
2125 static inline void double_raw_lock(raw_spinlock_t *l1, raw_spinlock_t *l2)
2126 {
2127 if (l1 > l2)
2128 swap(l1, l2);
2129
2130 raw_spin_lock(l1);
2131 raw_spin_lock_nested(l2, SINGLE_DEPTH_NESTING);
2132 }
2133
2134 /*
2135 * double_rq_lock - safely lock two runqueues
2136 *
2137 * Note this does not disable interrupts like task_rq_lock,
2138 * you need to do so manually before calling.
2139 */
2140 static inline void double_rq_lock(struct rq *rq1, struct rq *rq2)
2141 __acquires(rq1->lock)
2142 __acquires(rq2->lock)
2143 {
2144 BUG_ON(!irqs_disabled());
2145 if (rq1 == rq2) {
2146 raw_spin_lock(&rq1->lock);
2147 __acquire(rq2->lock); /* Fake it out ;) */
2148 } else {
2149 if (rq1 < rq2) {
2150 raw_spin_lock(&rq1->lock);
2151 raw_spin_lock_nested(&rq2->lock, SINGLE_DEPTH_NESTING);
2152 } else {
2153 raw_spin_lock(&rq2->lock);
2154 raw_spin_lock_nested(&rq1->lock, SINGLE_DEPTH_NESTING);
2155 }
2156 }
2157 }
2158
2159 /*
2160 * double_rq_unlock - safely unlock two runqueues
2161 *
2162 * Note this does not restore interrupts like task_rq_unlock,
2163 * you need to do so manually after calling.
2164 */
2165 static inline void double_rq_unlock(struct rq *rq1, struct rq *rq2)
2166 __releases(rq1->lock)
2167 __releases(rq2->lock)
2168 {
2169 raw_spin_unlock(&rq1->lock);
2170 if (rq1 != rq2)
2171 raw_spin_unlock(&rq2->lock);
2172 else
2173 __release(rq2->lock);
2174 }
2175
2176 extern void set_rq_online (struct rq *rq);
2177 extern void set_rq_offline(struct rq *rq);
2178 extern bool sched_smp_initialized;
2179
2180 #else /* CONFIG_SMP */
2181
2182 /*
2183 * double_rq_lock - safely lock two runqueues
2184 *
2185 * Note this does not disable interrupts like task_rq_lock,
2186 * you need to do so manually before calling.
2187 */
2188 static inline void double_rq_lock(struct rq *rq1, struct rq *rq2)
2189 __acquires(rq1->lock)
2190 __acquires(rq2->lock)
2191 {
2192 BUG_ON(!irqs_disabled());
2193 BUG_ON(rq1 != rq2);
2194 raw_spin_lock(&rq1->lock);
2195 __acquire(rq2->lock); /* Fake it out ;) */
2196 }
2197
2198 /*
2199 * double_rq_unlock - safely unlock two runqueues
2200 *
2201 * Note this does not restore interrupts like task_rq_unlock,
2202 * you need to do so manually after calling.
2203 */
2204 static inline void double_rq_unlock(struct rq *rq1, struct rq *rq2)
2205 __releases(rq1->lock)
2206 __releases(rq2->lock)
2207 {
2208 BUG_ON(rq1 != rq2);
2209 raw_spin_unlock(&rq1->lock);
2210 __release(rq2->lock);
2211 }
2212
2213 #endif
2214
2215 extern struct sched_entity *__pick_first_entity(struct cfs_rq *cfs_rq);
2216 extern struct sched_entity *__pick_last_entity(struct cfs_rq *cfs_rq);
2217
2218 #ifdef CONFIG_SCHED_DEBUG
2219 extern bool sched_debug_enabled;
2220
2221 extern void print_cfs_stats(struct seq_file *m, int cpu);
2222 extern void print_rt_stats(struct seq_file *m, int cpu);
2223 extern void print_dl_stats(struct seq_file *m, int cpu);
2224 extern void print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq);
2225 extern void print_rt_rq(struct seq_file *m, int cpu, struct rt_rq *rt_rq);
2226 extern void print_dl_rq(struct seq_file *m, int cpu, struct dl_rq *dl_rq);
2227 #ifdef CONFIG_NUMA_BALANCING
2228 extern void
2229 show_numa_stats(struct task_struct *p, struct seq_file *m);
2230 extern void
2231 print_numa_stats(struct seq_file *m, int node, unsigned long tsf,
2232 unsigned long tpf, unsigned long gsf, unsigned long gpf);
2233 #endif /* CONFIG_NUMA_BALANCING */
2234 #endif /* CONFIG_SCHED_DEBUG */
2235
2236 extern void init_cfs_rq(struct cfs_rq *cfs_rq);
2237 extern void init_rt_rq(struct rt_rq *rt_rq);
2238 extern void init_dl_rq(struct dl_rq *dl_rq);
2239
2240 extern void cfs_bandwidth_usage_inc(void);
2241 extern void cfs_bandwidth_usage_dec(void);
2242
2243 #ifdef CONFIG_NO_HZ_COMMON
2244 #define NOHZ_BALANCE_KICK_BIT 0
2245 #define NOHZ_STATS_KICK_BIT 1
2246
2247 #define NOHZ_BALANCE_KICK BIT(NOHZ_BALANCE_KICK_BIT)
2248 #define NOHZ_STATS_KICK BIT(NOHZ_STATS_KICK_BIT)
2249
2250 #define NOHZ_KICK_MASK (NOHZ_BALANCE_KICK | NOHZ_STATS_KICK)
2251
2252 #define nohz_flags(cpu) (&cpu_rq(cpu)->nohz_flags)
2253
2254 extern void nohz_balance_exit_idle(struct rq *rq);
2255 #else
2256 static inline void nohz_balance_exit_idle(struct rq *rq) { }
2257 #endif
2258
2259
2260 #ifdef CONFIG_SMP
2261 static inline
2262 void __dl_update(struct dl_bw *dl_b, s64 bw)
2263 {
2264 struct root_domain *rd = container_of(dl_b, struct root_domain, dl_bw);
2265 int i;
2266
2267 RCU_LOCKDEP_WARN(!rcu_read_lock_sched_held(),
2268 "sched RCU must be held");
2269 for_each_cpu_and(i, rd->span, cpu_active_mask) {
2270 struct rq *rq = cpu_rq(i);
2271
2272 rq->dl.extra_bw += bw;
2273 }
2274 }
2275 #else
2276 static inline
2277 void __dl_update(struct dl_bw *dl_b, s64 bw)
2278 {
2279 struct dl_rq *dl = container_of(dl_b, struct dl_rq, dl_bw);
2280
2281 dl->extra_bw += bw;
2282 }
2283 #endif
2284
2285
2286 #ifdef CONFIG_IRQ_TIME_ACCOUNTING
2287 struct irqtime {
2288 u64 total;
2289 u64 tick_delta;
2290 u64 irq_start_time;
2291 struct u64_stats_sync sync;
2292 };
2293
2294 DECLARE_PER_CPU(struct irqtime, cpu_irqtime);
2295
2296 /*
2297 * Returns the irqtime minus the softirq time computed by ksoftirqd.
2298 * Otherwise ksoftirqd's sum_exec_runtime is substracted its own runtime
2299 * and never move forward.
2300 */
2301 static inline u64 irq_time_read(int cpu)
2302 {
2303 struct irqtime *irqtime = &per_cpu(cpu_irqtime, cpu);
2304 unsigned int seq;
2305 u64 total;
2306
2307 do {
2308 seq = __u64_stats_fetch_begin(&irqtime->sync);
2309 total = irqtime->total;
2310 } while (__u64_stats_fetch_retry(&irqtime->sync, seq));
2311
2312 return total;
2313 }
2314 #endif /* CONFIG_IRQ_TIME_ACCOUNTING */
2315
2316 #ifdef CONFIG_CPU_FREQ
2317 DECLARE_PER_CPU(struct update_util_data __rcu *, cpufreq_update_util_data);
2318
2319 /**
2320 * cpufreq_update_util - Take a note about CPU utilization changes.
2321 * @rq: Runqueue to carry out the update for.
2322 * @flags: Update reason flags.
2323 *
2324 * This function is called by the scheduler on the CPU whose utilization is
2325 * being updated.
2326 *
2327 * It can only be called from RCU-sched read-side critical sections.
2328 *
2329 * The way cpufreq is currently arranged requires it to evaluate the CPU
2330 * performance state (frequency/voltage) on a regular basis to prevent it from
2331 * being stuck in a completely inadequate performance level for too long.
2332 * That is not guaranteed to happen if the updates are only triggered from CFS
2333 * and DL, though, because they may not be coming in if only RT tasks are
2334 * active all the time (or there are RT tasks only).
2335 *
2336 * As a workaround for that issue, this function is called periodically by the
2337 * RT sched class to trigger extra cpufreq updates to prevent it from stalling,
2338 * but that really is a band-aid. Going forward it should be replaced with
2339 * solutions targeted more specifically at RT tasks.
2340 */
2341 static inline void cpufreq_update_util(struct rq *rq, unsigned int flags)
2342 {
2343 struct update_util_data *data;
2344
2345 data = rcu_dereference_sched(*per_cpu_ptr(&cpufreq_update_util_data,
2346 cpu_of(rq)));
2347 if (data)
2348 data->func(data, rq_clock(rq), flags);
2349 }
2350 #else
2351 static inline void cpufreq_update_util(struct rq *rq, unsigned int flags) {}
2352 #endif /* CONFIG_CPU_FREQ */
2353
2354 #ifdef CONFIG_UCLAMP_TASK
2355 unsigned long uclamp_eff_value(struct task_struct *p, enum uclamp_id clamp_id);
2356
2357 static __always_inline
2358 unsigned long uclamp_rq_util_with(struct rq *rq, unsigned long util,
2359 struct task_struct *p)
2360 {
2361 unsigned long min_util = READ_ONCE(rq->uclamp[UCLAMP_MIN].value);
2362 unsigned long max_util = READ_ONCE(rq->uclamp[UCLAMP_MAX].value);
2363
2364 if (p) {
2365 min_util = max(min_util, uclamp_eff_value(p, UCLAMP_MIN));
2366 max_util = max(max_util, uclamp_eff_value(p, UCLAMP_MAX));
2367 }
2368
2369 /*
2370 * Since CPU's {min,max}_util clamps are MAX aggregated considering
2371 * RUNNABLE tasks with _different_ clamps, we can end up with an
2372 * inversion. Fix it now when the clamps are applied.
2373 */
2374 if (unlikely(min_util >= max_util))
2375 return min_util;
2376
2377 return clamp(util, min_util, max_util);
2378 }
2379 #else /* CONFIG_UCLAMP_TASK */
2380 static inline
2381 unsigned long uclamp_rq_util_with(struct rq *rq, unsigned long util,
2382 struct task_struct *p)
2383 {
2384 return util;
2385 }
2386 #endif /* CONFIG_UCLAMP_TASK */
2387
2388 #ifdef arch_scale_freq_capacity
2389 # ifndef arch_scale_freq_invariant
2390 # define arch_scale_freq_invariant() true
2391 # endif
2392 #else
2393 # define arch_scale_freq_invariant() false
2394 #endif
2395
2396 #ifdef CONFIG_SMP
2397 static inline unsigned long capacity_orig_of(int cpu)
2398 {
2399 return cpu_rq(cpu)->cpu_capacity_orig;
2400 }
2401 #endif
2402
2403 /**
2404 * enum schedutil_type - CPU utilization type
2405 * @FREQUENCY_UTIL: Utilization used to select frequency
2406 * @ENERGY_UTIL: Utilization used during energy calculation
2407 *
2408 * The utilization signals of all scheduling classes (CFS/RT/DL) and IRQ time
2409 * need to be aggregated differently depending on the usage made of them. This
2410 * enum is used within schedutil_freq_util() to differentiate the types of
2411 * utilization expected by the callers, and adjust the aggregation accordingly.
2412 */
2413 enum schedutil_type {
2414 FREQUENCY_UTIL,
2415 ENERGY_UTIL,
2416 };
2417
2418 #ifdef CONFIG_CPU_FREQ_GOV_SCHEDUTIL
2419
2420 unsigned long schedutil_cpu_util(int cpu, unsigned long util_cfs,
2421 unsigned long max, enum schedutil_type type,
2422 struct task_struct *p);
2423
2424 static inline unsigned long cpu_bw_dl(struct rq *rq)
2425 {
2426 return (rq->dl.running_bw * SCHED_CAPACITY_SCALE) >> BW_SHIFT;
2427 }
2428
2429 static inline unsigned long cpu_util_dl(struct rq *rq)
2430 {
2431 return READ_ONCE(rq->avg_dl.util_avg);
2432 }
2433
2434 static inline unsigned long cpu_util_cfs(struct rq *rq)
2435 {
2436 unsigned long util = READ_ONCE(rq->cfs.avg.util_avg);
2437
2438 if (sched_feat(UTIL_EST)) {
2439 util = max_t(unsigned long, util,
2440 READ_ONCE(rq->cfs.avg.util_est.enqueued));
2441 }
2442
2443 return util;
2444 }
2445
2446 static inline unsigned long cpu_util_rt(struct rq *rq)
2447 {
2448 return READ_ONCE(rq->avg_rt.util_avg);
2449 }
2450 #else /* CONFIG_CPU_FREQ_GOV_SCHEDUTIL */
2451 static inline unsigned long schedutil_cpu_util(int cpu, unsigned long util_cfs,
2452 unsigned long max, enum schedutil_type type,
2453 struct task_struct *p)
2454 {
2455 return 0;
2456 }
2457 #endif /* CONFIG_CPU_FREQ_GOV_SCHEDUTIL */
2458
2459 #ifdef CONFIG_HAVE_SCHED_AVG_IRQ
2460 static inline unsigned long cpu_util_irq(struct rq *rq)
2461 {
2462 return rq->avg_irq.util_avg;
2463 }
2464
2465 static inline
2466 unsigned long scale_irq_capacity(unsigned long util, unsigned long irq, unsigned long max)
2467 {
2468 util *= (max - irq);
2469 util /= max;
2470
2471 return util;
2472
2473 }
2474 #else
2475 static inline unsigned long cpu_util_irq(struct rq *rq)
2476 {
2477 return 0;
2478 }
2479
2480 static inline
2481 unsigned long scale_irq_capacity(unsigned long util, unsigned long irq, unsigned long max)
2482 {
2483 return util;
2484 }
2485 #endif
2486
2487 #if defined(CONFIG_ENERGY_MODEL) && defined(CONFIG_CPU_FREQ_GOV_SCHEDUTIL)
2488
2489 #define perf_domain_span(pd) (to_cpumask(((pd)->em_pd->cpus)))
2490
2491 DECLARE_STATIC_KEY_FALSE(sched_energy_present);
2492
2493 static inline bool sched_energy_enabled(void)
2494 {
2495 return static_branch_unlikely(&sched_energy_present);
2496 }
2497
2498 #else /* ! (CONFIG_ENERGY_MODEL && CONFIG_CPU_FREQ_GOV_SCHEDUTIL) */
2499
2500 #define perf_domain_span(pd) NULL
2501 static inline bool sched_energy_enabled(void) { return false; }
2502
2503 #endif /* CONFIG_ENERGY_MODEL && CONFIG_CPU_FREQ_GOV_SCHEDUTIL */
2504
2505 #ifdef CONFIG_MEMBARRIER
2506 /*
2507 * The scheduler provides memory barriers required by membarrier between:
2508 * - prior user-space memory accesses and store to rq->membarrier_state,
2509 * - store to rq->membarrier_state and following user-space memory accesses.
2510 * In the same way it provides those guarantees around store to rq->curr.
2511 */
2512 static inline void membarrier_switch_mm(struct rq *rq,
2513 struct mm_struct *prev_mm,
2514 struct mm_struct *next_mm)
2515 {
2516 int membarrier_state;
2517
2518 if (prev_mm == next_mm)
2519 return;
2520
2521 membarrier_state = atomic_read(&next_mm->membarrier_state);
2522 if (READ_ONCE(rq->membarrier_state) == membarrier_state)
2523 return;
2524
2525 WRITE_ONCE(rq->membarrier_state, membarrier_state);
2526 }
2527 #else
2528 static inline void membarrier_switch_mm(struct rq *rq,
2529 struct mm_struct *prev_mm,
2530 struct mm_struct *next_mm)
2531 {
2532 }
2533 #endif
2534
2535 #ifdef CONFIG_SMP
2536 static inline bool is_per_cpu_kthread(struct task_struct *p)
2537 {
2538 if (!(p->flags & PF_KTHREAD))
2539 return false;
2540
2541 if (p->nr_cpus_allowed != 1)
2542 return false;
2543
2544 return true;
2545 }
2546 #endif
2547
2548 void swake_up_all_locked(struct swait_queue_head *q);
2549 void __prepare_to_swait(struct swait_queue_head *q, struct swait_queue *wait);