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