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