]> git.proxmox.com Git - mirror_ubuntu-focal-kernel.git/blob - kernel/sched/sched.h
Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
[mirror_ubuntu-focal-kernel.git] / kernel / sched / sched.h
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_cached tasks_timeline;
430
431 /*
432 * 'curr' points to currently running entity on this cfs_rq.
433 * It is set to NULL otherwise (i.e when none are currently running).
434 */
435 struct sched_entity *curr, *next, *last, *skip;
436
437 #ifdef CONFIG_SCHED_DEBUG
438 unsigned int nr_spread_over;
439 #endif
440
441 #ifdef CONFIG_SMP
442 /*
443 * CFS load tracking
444 */
445 struct sched_avg avg;
446 u64 runnable_load_sum;
447 unsigned long runnable_load_avg;
448 #ifdef CONFIG_FAIR_GROUP_SCHED
449 unsigned long tg_load_avg_contrib;
450 unsigned long propagate_avg;
451 #endif
452 atomic_long_t removed_load_avg, removed_util_avg;
453 #ifndef CONFIG_64BIT
454 u64 load_last_update_time_copy;
455 #endif
456
457 #ifdef CONFIG_FAIR_GROUP_SCHED
458 /*
459 * h_load = weight * f(tg)
460 *
461 * Where f(tg) is the recursive weight fraction assigned to
462 * this group.
463 */
464 unsigned long h_load;
465 u64 last_h_load_update;
466 struct sched_entity *h_load_next;
467 #endif /* CONFIG_FAIR_GROUP_SCHED */
468 #endif /* CONFIG_SMP */
469
470 #ifdef CONFIG_FAIR_GROUP_SCHED
471 struct rq *rq; /* cpu runqueue to which this cfs_rq is attached */
472
473 /*
474 * leaf cfs_rqs are those that hold tasks (lowest schedulable entity in
475 * a hierarchy). Non-leaf lrqs hold other higher schedulable entities
476 * (like users, containers etc.)
477 *
478 * leaf_cfs_rq_list ties together list of leaf cfs_rq's in a cpu. This
479 * list is used during load balance.
480 */
481 int on_list;
482 struct list_head leaf_cfs_rq_list;
483 struct task_group *tg; /* group that "owns" this runqueue */
484
485 #ifdef CONFIG_CFS_BANDWIDTH
486 int runtime_enabled;
487 u64 runtime_expires;
488 s64 runtime_remaining;
489
490 u64 throttled_clock, throttled_clock_task;
491 u64 throttled_clock_task_time;
492 int throttled, throttle_count;
493 struct list_head throttled_list;
494 #endif /* CONFIG_CFS_BANDWIDTH */
495 #endif /* CONFIG_FAIR_GROUP_SCHED */
496 };
497
498 static inline int rt_bandwidth_enabled(void)
499 {
500 return sysctl_sched_rt_runtime >= 0;
501 }
502
503 /* RT IPI pull logic requires IRQ_WORK */
504 #ifdef CONFIG_IRQ_WORK
505 # define HAVE_RT_PUSH_IPI
506 #endif
507
508 /* Real-Time classes' related field in a runqueue: */
509 struct rt_rq {
510 struct rt_prio_array active;
511 unsigned int rt_nr_running;
512 unsigned int rr_nr_running;
513 #if defined CONFIG_SMP || defined CONFIG_RT_GROUP_SCHED
514 struct {
515 int curr; /* highest queued rt task prio */
516 #ifdef CONFIG_SMP
517 int next; /* next highest */
518 #endif
519 } highest_prio;
520 #endif
521 #ifdef CONFIG_SMP
522 unsigned long rt_nr_migratory;
523 unsigned long rt_nr_total;
524 int overloaded;
525 struct plist_head pushable_tasks;
526 #ifdef HAVE_RT_PUSH_IPI
527 int push_flags;
528 int push_cpu;
529 struct irq_work push_work;
530 raw_spinlock_t push_lock;
531 #endif
532 #endif /* CONFIG_SMP */
533 int rt_queued;
534
535 int rt_throttled;
536 u64 rt_time;
537 u64 rt_runtime;
538 /* Nests inside the rq lock: */
539 raw_spinlock_t rt_runtime_lock;
540
541 #ifdef CONFIG_RT_GROUP_SCHED
542 unsigned long rt_nr_boosted;
543
544 struct rq *rq;
545 struct task_group *tg;
546 #endif
547 };
548
549 /* Deadline class' related fields in a runqueue */
550 struct dl_rq {
551 /* runqueue is an rbtree, ordered by deadline */
552 struct rb_root_cached root;
553
554 unsigned long dl_nr_running;
555
556 #ifdef CONFIG_SMP
557 /*
558 * Deadline values of the currently executing and the
559 * earliest ready task on this rq. Caching these facilitates
560 * the decision wether or not a ready but not running task
561 * should migrate somewhere else.
562 */
563 struct {
564 u64 curr;
565 u64 next;
566 } earliest_dl;
567
568 unsigned long dl_nr_migratory;
569 int overloaded;
570
571 /*
572 * Tasks on this rq that can be pushed away. They are kept in
573 * an rb-tree, ordered by tasks' deadlines, with caching
574 * of the leftmost (earliest deadline) element.
575 */
576 struct rb_root_cached pushable_dl_tasks_root;
577 #else
578 struct dl_bw dl_bw;
579 #endif
580 /*
581 * "Active utilization" for this runqueue: increased when a
582 * task wakes up (becomes TASK_RUNNING) and decreased when a
583 * task blocks
584 */
585 u64 running_bw;
586
587 /*
588 * Utilization of the tasks "assigned" to this runqueue (including
589 * the tasks that are in runqueue and the tasks that executed on this
590 * CPU and blocked). Increased when a task moves to this runqueue, and
591 * decreased when the task moves away (migrates, changes scheduling
592 * policy, or terminates).
593 * This is needed to compute the "inactive utilization" for the
594 * runqueue (inactive utilization = this_bw - running_bw).
595 */
596 u64 this_bw;
597 u64 extra_bw;
598
599 /*
600 * Inverse of the fraction of CPU utilization that can be reclaimed
601 * by the GRUB algorithm.
602 */
603 u64 bw_ratio;
604 };
605
606 #ifdef CONFIG_SMP
607
608 static inline bool sched_asym_prefer(int a, int b)
609 {
610 return arch_asym_cpu_priority(a) > arch_asym_cpu_priority(b);
611 }
612
613 /*
614 * We add the notion of a root-domain which will be used to define per-domain
615 * variables. Each exclusive cpuset essentially defines an island domain by
616 * fully partitioning the member cpus from any other cpuset. Whenever a new
617 * exclusive cpuset is created, we also create and attach a new root-domain
618 * object.
619 *
620 */
621 struct root_domain {
622 atomic_t refcount;
623 atomic_t rto_count;
624 struct rcu_head rcu;
625 cpumask_var_t span;
626 cpumask_var_t online;
627
628 /* Indicate more than one runnable task for any CPU */
629 bool overload;
630
631 /*
632 * The bit corresponding to a CPU gets set here if such CPU has more
633 * than one runnable -deadline task (as it is below for RT tasks).
634 */
635 cpumask_var_t dlo_mask;
636 atomic_t dlo_count;
637 struct dl_bw dl_bw;
638 struct cpudl cpudl;
639
640 /*
641 * The "RT overload" flag: it gets set if a CPU has more than
642 * one runnable RT task.
643 */
644 cpumask_var_t rto_mask;
645 struct cpupri cpupri;
646
647 unsigned long max_cpu_capacity;
648 };
649
650 extern struct root_domain def_root_domain;
651 extern struct mutex sched_domains_mutex;
652
653 extern void init_defrootdomain(void);
654 extern int sched_init_domains(const struct cpumask *cpu_map);
655 extern void rq_attach_root(struct rq *rq, struct root_domain *rd);
656
657 #endif /* CONFIG_SMP */
658
659 /*
660 * This is the main, per-CPU runqueue data structure.
661 *
662 * Locking rule: those places that want to lock multiple runqueues
663 * (such as the load balancing or the thread migration code), lock
664 * acquire operations must be ordered by ascending &runqueue.
665 */
666 struct rq {
667 /* runqueue lock: */
668 raw_spinlock_t lock;
669
670 /*
671 * nr_running and cpu_load should be in the same cacheline because
672 * remote CPUs use both these fields when doing load calculation.
673 */
674 unsigned int nr_running;
675 #ifdef CONFIG_NUMA_BALANCING
676 unsigned int nr_numa_running;
677 unsigned int nr_preferred_running;
678 #endif
679 #define CPU_LOAD_IDX_MAX 5
680 unsigned long cpu_load[CPU_LOAD_IDX_MAX];
681 #ifdef CONFIG_NO_HZ_COMMON
682 #ifdef CONFIG_SMP
683 unsigned long last_load_update_tick;
684 #endif /* CONFIG_SMP */
685 unsigned long nohz_flags;
686 #endif /* CONFIG_NO_HZ_COMMON */
687 #ifdef CONFIG_NO_HZ_FULL
688 unsigned long last_sched_tick;
689 #endif
690 /* capture load from *all* tasks on this cpu: */
691 struct load_weight load;
692 unsigned long nr_load_updates;
693 u64 nr_switches;
694
695 struct cfs_rq cfs;
696 struct rt_rq rt;
697 struct dl_rq dl;
698
699 #ifdef CONFIG_FAIR_GROUP_SCHED
700 /* list of leaf cfs_rq on this cpu: */
701 struct list_head leaf_cfs_rq_list;
702 struct list_head *tmp_alone_branch;
703 #endif /* CONFIG_FAIR_GROUP_SCHED */
704
705 /*
706 * This is part of a global counter where only the total sum
707 * over all CPUs matters. A task can increase this counter on
708 * one CPU and if it got migrated afterwards it may decrease
709 * it on another CPU. Always updated under the runqueue lock:
710 */
711 unsigned long nr_uninterruptible;
712
713 struct task_struct *curr, *idle, *stop;
714 unsigned long next_balance;
715 struct mm_struct *prev_mm;
716
717 unsigned int clock_update_flags;
718 u64 clock;
719 u64 clock_task;
720
721 atomic_t nr_iowait;
722
723 #ifdef CONFIG_SMP
724 struct root_domain *rd;
725 struct sched_domain *sd;
726
727 unsigned long cpu_capacity;
728 unsigned long cpu_capacity_orig;
729
730 struct callback_head *balance_callback;
731
732 unsigned char idle_balance;
733 /* For active balancing */
734 int active_balance;
735 int push_cpu;
736 struct cpu_stop_work active_balance_work;
737 /* cpu of this runqueue: */
738 int cpu;
739 int online;
740
741 struct list_head cfs_tasks;
742
743 u64 rt_avg;
744 u64 age_stamp;
745 u64 idle_stamp;
746 u64 avg_idle;
747
748 /* This is used to determine avg_idle's max value */
749 u64 max_idle_balance_cost;
750 #endif
751
752 #ifdef CONFIG_IRQ_TIME_ACCOUNTING
753 u64 prev_irq_time;
754 #endif
755 #ifdef CONFIG_PARAVIRT
756 u64 prev_steal_time;
757 #endif
758 #ifdef CONFIG_PARAVIRT_TIME_ACCOUNTING
759 u64 prev_steal_time_rq;
760 #endif
761
762 /* calc_load related fields */
763 unsigned long calc_load_update;
764 long calc_load_active;
765
766 #ifdef CONFIG_SCHED_HRTICK
767 #ifdef CONFIG_SMP
768 int hrtick_csd_pending;
769 call_single_data_t hrtick_csd;
770 #endif
771 struct hrtimer hrtick_timer;
772 #endif
773
774 #ifdef CONFIG_SCHEDSTATS
775 /* latency stats */
776 struct sched_info rq_sched_info;
777 unsigned long long rq_cpu_time;
778 /* could above be rq->cfs_rq.exec_clock + rq->rt_rq.rt_runtime ? */
779
780 /* sys_sched_yield() stats */
781 unsigned int yld_count;
782
783 /* schedule() stats */
784 unsigned int sched_count;
785 unsigned int sched_goidle;
786
787 /* try_to_wake_up() stats */
788 unsigned int ttwu_count;
789 unsigned int ttwu_local;
790 #endif
791
792 #ifdef CONFIG_SMP
793 struct llist_head wake_list;
794 #endif
795
796 #ifdef CONFIG_CPU_IDLE
797 /* Must be inspected within a rcu lock section */
798 struct cpuidle_state *idle_state;
799 #endif
800 };
801
802 static inline int cpu_of(struct rq *rq)
803 {
804 #ifdef CONFIG_SMP
805 return rq->cpu;
806 #else
807 return 0;
808 #endif
809 }
810
811
812 #ifdef CONFIG_SCHED_SMT
813
814 extern struct static_key_false sched_smt_present;
815
816 extern void __update_idle_core(struct rq *rq);
817
818 static inline void update_idle_core(struct rq *rq)
819 {
820 if (static_branch_unlikely(&sched_smt_present))
821 __update_idle_core(rq);
822 }
823
824 #else
825 static inline void update_idle_core(struct rq *rq) { }
826 #endif
827
828 DECLARE_PER_CPU_SHARED_ALIGNED(struct rq, runqueues);
829
830 #define cpu_rq(cpu) (&per_cpu(runqueues, (cpu)))
831 #define this_rq() this_cpu_ptr(&runqueues)
832 #define task_rq(p) cpu_rq(task_cpu(p))
833 #define cpu_curr(cpu) (cpu_rq(cpu)->curr)
834 #define raw_rq() raw_cpu_ptr(&runqueues)
835
836 static inline u64 __rq_clock_broken(struct rq *rq)
837 {
838 return READ_ONCE(rq->clock);
839 }
840
841 /*
842 * rq::clock_update_flags bits
843 *
844 * %RQCF_REQ_SKIP - will request skipping of clock update on the next
845 * call to __schedule(). This is an optimisation to avoid
846 * neighbouring rq clock updates.
847 *
848 * %RQCF_ACT_SKIP - is set from inside of __schedule() when skipping is
849 * in effect and calls to update_rq_clock() are being ignored.
850 *
851 * %RQCF_UPDATED - is a debug flag that indicates whether a call has been
852 * made to update_rq_clock() since the last time rq::lock was pinned.
853 *
854 * If inside of __schedule(), clock_update_flags will have been
855 * shifted left (a left shift is a cheap operation for the fast path
856 * to promote %RQCF_REQ_SKIP to %RQCF_ACT_SKIP), so you must use,
857 *
858 * if (rq-clock_update_flags >= RQCF_UPDATED)
859 *
860 * to check if %RQCF_UPADTED is set. It'll never be shifted more than
861 * one position though, because the next rq_unpin_lock() will shift it
862 * back.
863 */
864 #define RQCF_REQ_SKIP 0x01
865 #define RQCF_ACT_SKIP 0x02
866 #define RQCF_UPDATED 0x04
867
868 static inline void assert_clock_updated(struct rq *rq)
869 {
870 /*
871 * The only reason for not seeing a clock update since the
872 * last rq_pin_lock() is if we're currently skipping updates.
873 */
874 SCHED_WARN_ON(rq->clock_update_flags < RQCF_ACT_SKIP);
875 }
876
877 static inline u64 rq_clock(struct rq *rq)
878 {
879 lockdep_assert_held(&rq->lock);
880 assert_clock_updated(rq);
881
882 return rq->clock;
883 }
884
885 static inline u64 rq_clock_task(struct rq *rq)
886 {
887 lockdep_assert_held(&rq->lock);
888 assert_clock_updated(rq);
889
890 return rq->clock_task;
891 }
892
893 static inline void rq_clock_skip_update(struct rq *rq, bool skip)
894 {
895 lockdep_assert_held(&rq->lock);
896 if (skip)
897 rq->clock_update_flags |= RQCF_REQ_SKIP;
898 else
899 rq->clock_update_flags &= ~RQCF_REQ_SKIP;
900 }
901
902 struct rq_flags {
903 unsigned long flags;
904 struct pin_cookie cookie;
905 #ifdef CONFIG_SCHED_DEBUG
906 /*
907 * A copy of (rq::clock_update_flags & RQCF_UPDATED) for the
908 * current pin context is stashed here in case it needs to be
909 * restored in rq_repin_lock().
910 */
911 unsigned int clock_update_flags;
912 #endif
913 };
914
915 static inline void rq_pin_lock(struct rq *rq, struct rq_flags *rf)
916 {
917 rf->cookie = lockdep_pin_lock(&rq->lock);
918
919 #ifdef CONFIG_SCHED_DEBUG
920 rq->clock_update_flags &= (RQCF_REQ_SKIP|RQCF_ACT_SKIP);
921 rf->clock_update_flags = 0;
922 #endif
923 }
924
925 static inline void rq_unpin_lock(struct rq *rq, struct rq_flags *rf)
926 {
927 #ifdef CONFIG_SCHED_DEBUG
928 if (rq->clock_update_flags > RQCF_ACT_SKIP)
929 rf->clock_update_flags = RQCF_UPDATED;
930 #endif
931
932 lockdep_unpin_lock(&rq->lock, rf->cookie);
933 }
934
935 static inline void rq_repin_lock(struct rq *rq, struct rq_flags *rf)
936 {
937 lockdep_repin_lock(&rq->lock, rf->cookie);
938
939 #ifdef CONFIG_SCHED_DEBUG
940 /*
941 * Restore the value we stashed in @rf for this pin context.
942 */
943 rq->clock_update_flags |= rf->clock_update_flags;
944 #endif
945 }
946
947 #ifdef CONFIG_NUMA
948 enum numa_topology_type {
949 NUMA_DIRECT,
950 NUMA_GLUELESS_MESH,
951 NUMA_BACKPLANE,
952 };
953 extern enum numa_topology_type sched_numa_topology_type;
954 extern int sched_max_numa_distance;
955 extern bool find_numa_distance(int distance);
956 #endif
957
958 #ifdef CONFIG_NUMA
959 extern void sched_init_numa(void);
960 extern void sched_domains_numa_masks_set(unsigned int cpu);
961 extern void sched_domains_numa_masks_clear(unsigned int cpu);
962 #else
963 static inline void sched_init_numa(void) { }
964 static inline void sched_domains_numa_masks_set(unsigned int cpu) { }
965 static inline void sched_domains_numa_masks_clear(unsigned int cpu) { }
966 #endif
967
968 #ifdef CONFIG_NUMA_BALANCING
969 /* The regions in numa_faults array from task_struct */
970 enum numa_faults_stats {
971 NUMA_MEM = 0,
972 NUMA_CPU,
973 NUMA_MEMBUF,
974 NUMA_CPUBUF
975 };
976 extern void sched_setnuma(struct task_struct *p, int node);
977 extern int migrate_task_to(struct task_struct *p, int cpu);
978 extern int migrate_swap(struct task_struct *, struct task_struct *);
979 #endif /* CONFIG_NUMA_BALANCING */
980
981 #ifdef CONFIG_SMP
982
983 static inline void
984 queue_balance_callback(struct rq *rq,
985 struct callback_head *head,
986 void (*func)(struct rq *rq))
987 {
988 lockdep_assert_held(&rq->lock);
989
990 if (unlikely(head->next))
991 return;
992
993 head->func = (void (*)(struct callback_head *))func;
994 head->next = rq->balance_callback;
995 rq->balance_callback = head;
996 }
997
998 extern void sched_ttwu_pending(void);
999
1000 #define rcu_dereference_check_sched_domain(p) \
1001 rcu_dereference_check((p), \
1002 lockdep_is_held(&sched_domains_mutex))
1003
1004 /*
1005 * The domain tree (rq->sd) is protected by RCU's quiescent state transition.
1006 * See detach_destroy_domains: synchronize_sched for details.
1007 *
1008 * The domain tree of any CPU may only be accessed from within
1009 * preempt-disabled sections.
1010 */
1011 #define for_each_domain(cpu, __sd) \
1012 for (__sd = rcu_dereference_check_sched_domain(cpu_rq(cpu)->sd); \
1013 __sd; __sd = __sd->parent)
1014
1015 #define for_each_lower_domain(sd) for (; sd; sd = sd->child)
1016
1017 /**
1018 * highest_flag_domain - Return highest sched_domain containing flag.
1019 * @cpu: The cpu whose highest level of sched domain is to
1020 * be returned.
1021 * @flag: The flag to check for the highest sched_domain
1022 * for the given cpu.
1023 *
1024 * Returns the highest sched_domain of a cpu which contains the given flag.
1025 */
1026 static inline struct sched_domain *highest_flag_domain(int cpu, int flag)
1027 {
1028 struct sched_domain *sd, *hsd = NULL;
1029
1030 for_each_domain(cpu, sd) {
1031 if (!(sd->flags & flag))
1032 break;
1033 hsd = sd;
1034 }
1035
1036 return hsd;
1037 }
1038
1039 static inline struct sched_domain *lowest_flag_domain(int cpu, int flag)
1040 {
1041 struct sched_domain *sd;
1042
1043 for_each_domain(cpu, sd) {
1044 if (sd->flags & flag)
1045 break;
1046 }
1047
1048 return sd;
1049 }
1050
1051 DECLARE_PER_CPU(struct sched_domain *, sd_llc);
1052 DECLARE_PER_CPU(int, sd_llc_size);
1053 DECLARE_PER_CPU(int, sd_llc_id);
1054 DECLARE_PER_CPU(struct sched_domain_shared *, sd_llc_shared);
1055 DECLARE_PER_CPU(struct sched_domain *, sd_numa);
1056 DECLARE_PER_CPU(struct sched_domain *, sd_asym);
1057
1058 struct sched_group_capacity {
1059 atomic_t ref;
1060 /*
1061 * CPU capacity of this group, SCHED_CAPACITY_SCALE being max capacity
1062 * for a single CPU.
1063 */
1064 unsigned long capacity;
1065 unsigned long min_capacity; /* Min per-CPU capacity in group */
1066 unsigned long next_update;
1067 int imbalance; /* XXX unrelated to capacity but shared group state */
1068
1069 #ifdef CONFIG_SCHED_DEBUG
1070 int id;
1071 #endif
1072
1073 unsigned long cpumask[0]; /* balance mask */
1074 };
1075
1076 struct sched_group {
1077 struct sched_group *next; /* Must be a circular list */
1078 atomic_t ref;
1079
1080 unsigned int group_weight;
1081 struct sched_group_capacity *sgc;
1082 int asym_prefer_cpu; /* cpu of highest priority in group */
1083
1084 /*
1085 * The CPUs this group covers.
1086 *
1087 * NOTE: this field is variable length. (Allocated dynamically
1088 * by attaching extra space to the end of the structure,
1089 * depending on how many CPUs the kernel has booted up with)
1090 */
1091 unsigned long cpumask[0];
1092 };
1093
1094 static inline struct cpumask *sched_group_span(struct sched_group *sg)
1095 {
1096 return to_cpumask(sg->cpumask);
1097 }
1098
1099 /*
1100 * See build_balance_mask().
1101 */
1102 static inline struct cpumask *group_balance_mask(struct sched_group *sg)
1103 {
1104 return to_cpumask(sg->sgc->cpumask);
1105 }
1106
1107 /**
1108 * group_first_cpu - Returns the first cpu in the cpumask of a sched_group.
1109 * @group: The group whose first cpu is to be returned.
1110 */
1111 static inline unsigned int group_first_cpu(struct sched_group *group)
1112 {
1113 return cpumask_first(sched_group_span(group));
1114 }
1115
1116 extern int group_balance_cpu(struct sched_group *sg);
1117
1118 #if defined(CONFIG_SCHED_DEBUG) && defined(CONFIG_SYSCTL)
1119 void register_sched_domain_sysctl(void);
1120 void dirty_sched_domain_sysctl(int cpu);
1121 void unregister_sched_domain_sysctl(void);
1122 #else
1123 static inline void register_sched_domain_sysctl(void)
1124 {
1125 }
1126 static inline void dirty_sched_domain_sysctl(int cpu)
1127 {
1128 }
1129 static inline void unregister_sched_domain_sysctl(void)
1130 {
1131 }
1132 #endif
1133
1134 #else
1135
1136 static inline void sched_ttwu_pending(void) { }
1137
1138 #endif /* CONFIG_SMP */
1139
1140 #include "stats.h"
1141 #include "autogroup.h"
1142
1143 #ifdef CONFIG_CGROUP_SCHED
1144
1145 /*
1146 * Return the group to which this tasks belongs.
1147 *
1148 * We cannot use task_css() and friends because the cgroup subsystem
1149 * changes that value before the cgroup_subsys::attach() method is called,
1150 * therefore we cannot pin it and might observe the wrong value.
1151 *
1152 * The same is true for autogroup's p->signal->autogroup->tg, the autogroup
1153 * core changes this before calling sched_move_task().
1154 *
1155 * Instead we use a 'copy' which is updated from sched_move_task() while
1156 * holding both task_struct::pi_lock and rq::lock.
1157 */
1158 static inline struct task_group *task_group(struct task_struct *p)
1159 {
1160 return p->sched_task_group;
1161 }
1162
1163 /* Change a task's cfs_rq and parent entity if it moves across CPUs/groups */
1164 static inline void set_task_rq(struct task_struct *p, unsigned int cpu)
1165 {
1166 #if defined(CONFIG_FAIR_GROUP_SCHED) || defined(CONFIG_RT_GROUP_SCHED)
1167 struct task_group *tg = task_group(p);
1168 #endif
1169
1170 #ifdef CONFIG_FAIR_GROUP_SCHED
1171 set_task_rq_fair(&p->se, p->se.cfs_rq, tg->cfs_rq[cpu]);
1172 p->se.cfs_rq = tg->cfs_rq[cpu];
1173 p->se.parent = tg->se[cpu];
1174 #endif
1175
1176 #ifdef CONFIG_RT_GROUP_SCHED
1177 p->rt.rt_rq = tg->rt_rq[cpu];
1178 p->rt.parent = tg->rt_se[cpu];
1179 #endif
1180 }
1181
1182 #else /* CONFIG_CGROUP_SCHED */
1183
1184 static inline void set_task_rq(struct task_struct *p, unsigned int cpu) { }
1185 static inline struct task_group *task_group(struct task_struct *p)
1186 {
1187 return NULL;
1188 }
1189
1190 #endif /* CONFIG_CGROUP_SCHED */
1191
1192 static inline void __set_task_cpu(struct task_struct *p, unsigned int cpu)
1193 {
1194 set_task_rq(p, cpu);
1195 #ifdef CONFIG_SMP
1196 /*
1197 * After ->cpu is set up to a new value, task_rq_lock(p, ...) can be
1198 * successfuly executed on another CPU. We must ensure that updates of
1199 * per-task data have been completed by this moment.
1200 */
1201 smp_wmb();
1202 #ifdef CONFIG_THREAD_INFO_IN_TASK
1203 p->cpu = cpu;
1204 #else
1205 task_thread_info(p)->cpu = cpu;
1206 #endif
1207 p->wake_cpu = cpu;
1208 #endif
1209 }
1210
1211 /*
1212 * Tunables that become constants when CONFIG_SCHED_DEBUG is off:
1213 */
1214 #ifdef CONFIG_SCHED_DEBUG
1215 # include <linux/static_key.h>
1216 # define const_debug __read_mostly
1217 #else
1218 # define const_debug const
1219 #endif
1220
1221 extern const_debug unsigned int sysctl_sched_features;
1222
1223 #define SCHED_FEAT(name, enabled) \
1224 __SCHED_FEAT_##name ,
1225
1226 enum {
1227 #include "features.h"
1228 __SCHED_FEAT_NR,
1229 };
1230
1231 #undef SCHED_FEAT
1232
1233 #if defined(CONFIG_SCHED_DEBUG) && defined(HAVE_JUMP_LABEL)
1234 #define SCHED_FEAT(name, enabled) \
1235 static __always_inline bool static_branch_##name(struct static_key *key) \
1236 { \
1237 return static_key_##enabled(key); \
1238 }
1239
1240 #include "features.h"
1241
1242 #undef SCHED_FEAT
1243
1244 extern struct static_key sched_feat_keys[__SCHED_FEAT_NR];
1245 #define sched_feat(x) (static_branch_##x(&sched_feat_keys[__SCHED_FEAT_##x]))
1246 #else /* !(SCHED_DEBUG && HAVE_JUMP_LABEL) */
1247 #define sched_feat(x) (sysctl_sched_features & (1UL << __SCHED_FEAT_##x))
1248 #endif /* SCHED_DEBUG && HAVE_JUMP_LABEL */
1249
1250 extern struct static_key_false sched_numa_balancing;
1251 extern struct static_key_false sched_schedstats;
1252
1253 static inline u64 global_rt_period(void)
1254 {
1255 return (u64)sysctl_sched_rt_period * NSEC_PER_USEC;
1256 }
1257
1258 static inline u64 global_rt_runtime(void)
1259 {
1260 if (sysctl_sched_rt_runtime < 0)
1261 return RUNTIME_INF;
1262
1263 return (u64)sysctl_sched_rt_runtime * NSEC_PER_USEC;
1264 }
1265
1266 static inline int task_current(struct rq *rq, struct task_struct *p)
1267 {
1268 return rq->curr == p;
1269 }
1270
1271 static inline int task_running(struct rq *rq, struct task_struct *p)
1272 {
1273 #ifdef CONFIG_SMP
1274 return p->on_cpu;
1275 #else
1276 return task_current(rq, p);
1277 #endif
1278 }
1279
1280 static inline int task_on_rq_queued(struct task_struct *p)
1281 {
1282 return p->on_rq == TASK_ON_RQ_QUEUED;
1283 }
1284
1285 static inline int task_on_rq_migrating(struct task_struct *p)
1286 {
1287 return p->on_rq == TASK_ON_RQ_MIGRATING;
1288 }
1289
1290 #ifndef prepare_arch_switch
1291 # define prepare_arch_switch(next) do { } while (0)
1292 #endif
1293 #ifndef finish_arch_post_lock_switch
1294 # define finish_arch_post_lock_switch() do { } while (0)
1295 #endif
1296
1297 static inline void prepare_lock_switch(struct rq *rq, struct task_struct *next)
1298 {
1299 #ifdef CONFIG_SMP
1300 /*
1301 * We can optimise this out completely for !SMP, because the
1302 * SMP rebalancing from interrupt is the only thing that cares
1303 * here.
1304 */
1305 next->on_cpu = 1;
1306 #endif
1307 }
1308
1309 static inline void finish_lock_switch(struct rq *rq, struct task_struct *prev)
1310 {
1311 #ifdef CONFIG_SMP
1312 /*
1313 * After ->on_cpu is cleared, the task can be moved to a different CPU.
1314 * We must ensure this doesn't happen until the switch is completely
1315 * finished.
1316 *
1317 * In particular, the load of prev->state in finish_task_switch() must
1318 * happen before this.
1319 *
1320 * Pairs with the smp_cond_load_acquire() in try_to_wake_up().
1321 */
1322 smp_store_release(&prev->on_cpu, 0);
1323 #endif
1324 #ifdef CONFIG_DEBUG_SPINLOCK
1325 /* this is a valid case when another task releases the spinlock */
1326 rq->lock.owner = current;
1327 #endif
1328 /*
1329 * If we are tracking spinlock dependencies then we have to
1330 * fix up the runqueue lock - which gets 'carried over' from
1331 * prev into current:
1332 */
1333 spin_acquire(&rq->lock.dep_map, 0, 0, _THIS_IP_);
1334
1335 raw_spin_unlock_irq(&rq->lock);
1336 }
1337
1338 /*
1339 * wake flags
1340 */
1341 #define WF_SYNC 0x01 /* waker goes to sleep after wakeup */
1342 #define WF_FORK 0x02 /* child wakeup after fork */
1343 #define WF_MIGRATED 0x4 /* internal use, task got migrated */
1344
1345 /*
1346 * To aid in avoiding the subversion of "niceness" due to uneven distribution
1347 * of tasks with abnormal "nice" values across CPUs the contribution that
1348 * each task makes to its run queue's load is weighted according to its
1349 * scheduling class and "nice" value. For SCHED_NORMAL tasks this is just a
1350 * scaled version of the new time slice allocation that they receive on time
1351 * slice expiry etc.
1352 */
1353
1354 #define WEIGHT_IDLEPRIO 3
1355 #define WMULT_IDLEPRIO 1431655765
1356
1357 extern const int sched_prio_to_weight[40];
1358 extern const u32 sched_prio_to_wmult[40];
1359
1360 /*
1361 * {de,en}queue flags:
1362 *
1363 * DEQUEUE_SLEEP - task is no longer runnable
1364 * ENQUEUE_WAKEUP - task just became runnable
1365 *
1366 * SAVE/RESTORE - an otherwise spurious dequeue/enqueue, done to ensure tasks
1367 * are in a known state which allows modification. Such pairs
1368 * should preserve as much state as possible.
1369 *
1370 * MOVE - paired with SAVE/RESTORE, explicitly does not preserve the location
1371 * in the runqueue.
1372 *
1373 * ENQUEUE_HEAD - place at front of runqueue (tail if not specified)
1374 * ENQUEUE_REPLENISH - CBS (replenish runtime and postpone deadline)
1375 * ENQUEUE_MIGRATED - the task was migrated during wakeup
1376 *
1377 */
1378
1379 #define DEQUEUE_SLEEP 0x01
1380 #define DEQUEUE_SAVE 0x02 /* matches ENQUEUE_RESTORE */
1381 #define DEQUEUE_MOVE 0x04 /* matches ENQUEUE_MOVE */
1382 #define DEQUEUE_NOCLOCK 0x08 /* matches ENQUEUE_NOCLOCK */
1383
1384 #define ENQUEUE_WAKEUP 0x01
1385 #define ENQUEUE_RESTORE 0x02
1386 #define ENQUEUE_MOVE 0x04
1387 #define ENQUEUE_NOCLOCK 0x08
1388
1389 #define ENQUEUE_HEAD 0x10
1390 #define ENQUEUE_REPLENISH 0x20
1391 #ifdef CONFIG_SMP
1392 #define ENQUEUE_MIGRATED 0x40
1393 #else
1394 #define ENQUEUE_MIGRATED 0x00
1395 #endif
1396
1397 #define RETRY_TASK ((void *)-1UL)
1398
1399 struct sched_class {
1400 const struct sched_class *next;
1401
1402 void (*enqueue_task) (struct rq *rq, struct task_struct *p, int flags);
1403 void (*dequeue_task) (struct rq *rq, struct task_struct *p, int flags);
1404 void (*yield_task) (struct rq *rq);
1405 bool (*yield_to_task) (struct rq *rq, struct task_struct *p, bool preempt);
1406
1407 void (*check_preempt_curr) (struct rq *rq, struct task_struct *p, int flags);
1408
1409 /*
1410 * It is the responsibility of the pick_next_task() method that will
1411 * return the next task to call put_prev_task() on the @prev task or
1412 * something equivalent.
1413 *
1414 * May return RETRY_TASK when it finds a higher prio class has runnable
1415 * tasks.
1416 */
1417 struct task_struct * (*pick_next_task) (struct rq *rq,
1418 struct task_struct *prev,
1419 struct rq_flags *rf);
1420 void (*put_prev_task) (struct rq *rq, struct task_struct *p);
1421
1422 #ifdef CONFIG_SMP
1423 int (*select_task_rq)(struct task_struct *p, int task_cpu, int sd_flag, int flags);
1424 void (*migrate_task_rq)(struct task_struct *p);
1425
1426 void (*task_woken) (struct rq *this_rq, struct task_struct *task);
1427
1428 void (*set_cpus_allowed)(struct task_struct *p,
1429 const struct cpumask *newmask);
1430
1431 void (*rq_online)(struct rq *rq);
1432 void (*rq_offline)(struct rq *rq);
1433 #endif
1434
1435 void (*set_curr_task) (struct rq *rq);
1436 void (*task_tick) (struct rq *rq, struct task_struct *p, int queued);
1437 void (*task_fork) (struct task_struct *p);
1438 void (*task_dead) (struct task_struct *p);
1439
1440 /*
1441 * The switched_from() call is allowed to drop rq->lock, therefore we
1442 * cannot assume the switched_from/switched_to pair is serliazed by
1443 * rq->lock. They are however serialized by p->pi_lock.
1444 */
1445 void (*switched_from) (struct rq *this_rq, struct task_struct *task);
1446 void (*switched_to) (struct rq *this_rq, struct task_struct *task);
1447 void (*prio_changed) (struct rq *this_rq, struct task_struct *task,
1448 int oldprio);
1449
1450 unsigned int (*get_rr_interval) (struct rq *rq,
1451 struct task_struct *task);
1452
1453 void (*update_curr) (struct rq *rq);
1454
1455 #define TASK_SET_GROUP 0
1456 #define TASK_MOVE_GROUP 1
1457
1458 #ifdef CONFIG_FAIR_GROUP_SCHED
1459 void (*task_change_group) (struct task_struct *p, int type);
1460 #endif
1461 };
1462
1463 static inline void put_prev_task(struct rq *rq, struct task_struct *prev)
1464 {
1465 prev->sched_class->put_prev_task(rq, prev);
1466 }
1467
1468 static inline void set_curr_task(struct rq *rq, struct task_struct *curr)
1469 {
1470 curr->sched_class->set_curr_task(rq);
1471 }
1472
1473 #ifdef CONFIG_SMP
1474 #define sched_class_highest (&stop_sched_class)
1475 #else
1476 #define sched_class_highest (&dl_sched_class)
1477 #endif
1478 #define for_each_class(class) \
1479 for (class = sched_class_highest; class; class = class->next)
1480
1481 extern const struct sched_class stop_sched_class;
1482 extern const struct sched_class dl_sched_class;
1483 extern const struct sched_class rt_sched_class;
1484 extern const struct sched_class fair_sched_class;
1485 extern const struct sched_class idle_sched_class;
1486
1487
1488 #ifdef CONFIG_SMP
1489
1490 extern void update_group_capacity(struct sched_domain *sd, int cpu);
1491
1492 extern void trigger_load_balance(struct rq *rq);
1493
1494 extern void set_cpus_allowed_common(struct task_struct *p, const struct cpumask *new_mask);
1495
1496 #endif
1497
1498 #ifdef CONFIG_CPU_IDLE
1499 static inline void idle_set_state(struct rq *rq,
1500 struct cpuidle_state *idle_state)
1501 {
1502 rq->idle_state = idle_state;
1503 }
1504
1505 static inline struct cpuidle_state *idle_get_state(struct rq *rq)
1506 {
1507 SCHED_WARN_ON(!rcu_read_lock_held());
1508 return rq->idle_state;
1509 }
1510 #else
1511 static inline void idle_set_state(struct rq *rq,
1512 struct cpuidle_state *idle_state)
1513 {
1514 }
1515
1516 static inline struct cpuidle_state *idle_get_state(struct rq *rq)
1517 {
1518 return NULL;
1519 }
1520 #endif
1521
1522 extern void schedule_idle(void);
1523
1524 extern void sysrq_sched_debug_show(void);
1525 extern void sched_init_granularity(void);
1526 extern void update_max_interval(void);
1527
1528 extern void init_sched_dl_class(void);
1529 extern void init_sched_rt_class(void);
1530 extern void init_sched_fair_class(void);
1531
1532 extern void resched_curr(struct rq *rq);
1533 extern void resched_cpu(int cpu);
1534
1535 extern struct rt_bandwidth def_rt_bandwidth;
1536 extern void init_rt_bandwidth(struct rt_bandwidth *rt_b, u64 period, u64 runtime);
1537
1538 extern struct dl_bandwidth def_dl_bandwidth;
1539 extern void init_dl_bandwidth(struct dl_bandwidth *dl_b, u64 period, u64 runtime);
1540 extern void init_dl_task_timer(struct sched_dl_entity *dl_se);
1541 extern void init_dl_inactive_task_timer(struct sched_dl_entity *dl_se);
1542 extern void init_dl_rq_bw_ratio(struct dl_rq *dl_rq);
1543
1544 #define BW_SHIFT 20
1545 #define BW_UNIT (1 << BW_SHIFT)
1546 #define RATIO_SHIFT 8
1547 unsigned long to_ratio(u64 period, u64 runtime);
1548
1549 extern void init_entity_runnable_average(struct sched_entity *se);
1550 extern void post_init_entity_util_avg(struct sched_entity *se);
1551
1552 #ifdef CONFIG_NO_HZ_FULL
1553 extern bool sched_can_stop_tick(struct rq *rq);
1554
1555 /*
1556 * Tick may be needed by tasks in the runqueue depending on their policy and
1557 * requirements. If tick is needed, lets send the target an IPI to kick it out of
1558 * nohz mode if necessary.
1559 */
1560 static inline void sched_update_tick_dependency(struct rq *rq)
1561 {
1562 int cpu;
1563
1564 if (!tick_nohz_full_enabled())
1565 return;
1566
1567 cpu = cpu_of(rq);
1568
1569 if (!tick_nohz_full_cpu(cpu))
1570 return;
1571
1572 if (sched_can_stop_tick(rq))
1573 tick_nohz_dep_clear_cpu(cpu, TICK_DEP_BIT_SCHED);
1574 else
1575 tick_nohz_dep_set_cpu(cpu, TICK_DEP_BIT_SCHED);
1576 }
1577 #else
1578 static inline void sched_update_tick_dependency(struct rq *rq) { }
1579 #endif
1580
1581 static inline void add_nr_running(struct rq *rq, unsigned count)
1582 {
1583 unsigned prev_nr = rq->nr_running;
1584
1585 rq->nr_running = prev_nr + count;
1586
1587 if (prev_nr < 2 && rq->nr_running >= 2) {
1588 #ifdef CONFIG_SMP
1589 if (!rq->rd->overload)
1590 rq->rd->overload = true;
1591 #endif
1592 }
1593
1594 sched_update_tick_dependency(rq);
1595 }
1596
1597 static inline void sub_nr_running(struct rq *rq, unsigned count)
1598 {
1599 rq->nr_running -= count;
1600 /* Check if we still need preemption */
1601 sched_update_tick_dependency(rq);
1602 }
1603
1604 static inline void rq_last_tick_reset(struct rq *rq)
1605 {
1606 #ifdef CONFIG_NO_HZ_FULL
1607 rq->last_sched_tick = jiffies;
1608 #endif
1609 }
1610
1611 extern void update_rq_clock(struct rq *rq);
1612
1613 extern void activate_task(struct rq *rq, struct task_struct *p, int flags);
1614 extern void deactivate_task(struct rq *rq, struct task_struct *p, int flags);
1615
1616 extern void check_preempt_curr(struct rq *rq, struct task_struct *p, int flags);
1617
1618 extern const_debug unsigned int sysctl_sched_time_avg;
1619 extern const_debug unsigned int sysctl_sched_nr_migrate;
1620 extern const_debug unsigned int sysctl_sched_migration_cost;
1621
1622 static inline u64 sched_avg_period(void)
1623 {
1624 return (u64)sysctl_sched_time_avg * NSEC_PER_MSEC / 2;
1625 }
1626
1627 #ifdef CONFIG_SCHED_HRTICK
1628
1629 /*
1630 * Use hrtick when:
1631 * - enabled by features
1632 * - hrtimer is actually high res
1633 */
1634 static inline int hrtick_enabled(struct rq *rq)
1635 {
1636 if (!sched_feat(HRTICK))
1637 return 0;
1638 if (!cpu_active(cpu_of(rq)))
1639 return 0;
1640 return hrtimer_is_hres_active(&rq->hrtick_timer);
1641 }
1642
1643 void hrtick_start(struct rq *rq, u64 delay);
1644
1645 #else
1646
1647 static inline int hrtick_enabled(struct rq *rq)
1648 {
1649 return 0;
1650 }
1651
1652 #endif /* CONFIG_SCHED_HRTICK */
1653
1654 #ifdef CONFIG_SMP
1655 extern void sched_avg_update(struct rq *rq);
1656
1657 #ifndef arch_scale_freq_capacity
1658 static __always_inline
1659 unsigned long arch_scale_freq_capacity(struct sched_domain *sd, int cpu)
1660 {
1661 return SCHED_CAPACITY_SCALE;
1662 }
1663 #endif
1664
1665 #ifndef arch_scale_cpu_capacity
1666 static __always_inline
1667 unsigned long arch_scale_cpu_capacity(struct sched_domain *sd, int cpu)
1668 {
1669 if (sd && (sd->flags & SD_SHARE_CPUCAPACITY) && (sd->span_weight > 1))
1670 return sd->smt_gain / sd->span_weight;
1671
1672 return SCHED_CAPACITY_SCALE;
1673 }
1674 #endif
1675
1676 static inline void sched_rt_avg_update(struct rq *rq, u64 rt_delta)
1677 {
1678 rq->rt_avg += rt_delta * arch_scale_freq_capacity(NULL, cpu_of(rq));
1679 sched_avg_update(rq);
1680 }
1681 #else
1682 static inline void sched_rt_avg_update(struct rq *rq, u64 rt_delta) { }
1683 static inline void sched_avg_update(struct rq *rq) { }
1684 #endif
1685
1686 struct rq *__task_rq_lock(struct task_struct *p, struct rq_flags *rf)
1687 __acquires(rq->lock);
1688
1689 struct rq *task_rq_lock(struct task_struct *p, struct rq_flags *rf)
1690 __acquires(p->pi_lock)
1691 __acquires(rq->lock);
1692
1693 static inline void __task_rq_unlock(struct rq *rq, struct rq_flags *rf)
1694 __releases(rq->lock)
1695 {
1696 rq_unpin_lock(rq, rf);
1697 raw_spin_unlock(&rq->lock);
1698 }
1699
1700 static inline void
1701 task_rq_unlock(struct rq *rq, struct task_struct *p, struct rq_flags *rf)
1702 __releases(rq->lock)
1703 __releases(p->pi_lock)
1704 {
1705 rq_unpin_lock(rq, rf);
1706 raw_spin_unlock(&rq->lock);
1707 raw_spin_unlock_irqrestore(&p->pi_lock, rf->flags);
1708 }
1709
1710 static inline void
1711 rq_lock_irqsave(struct rq *rq, struct rq_flags *rf)
1712 __acquires(rq->lock)
1713 {
1714 raw_spin_lock_irqsave(&rq->lock, rf->flags);
1715 rq_pin_lock(rq, rf);
1716 }
1717
1718 static inline void
1719 rq_lock_irq(struct rq *rq, struct rq_flags *rf)
1720 __acquires(rq->lock)
1721 {
1722 raw_spin_lock_irq(&rq->lock);
1723 rq_pin_lock(rq, rf);
1724 }
1725
1726 static inline void
1727 rq_lock(struct rq *rq, struct rq_flags *rf)
1728 __acquires(rq->lock)
1729 {
1730 raw_spin_lock(&rq->lock);
1731 rq_pin_lock(rq, rf);
1732 }
1733
1734 static inline void
1735 rq_relock(struct rq *rq, struct rq_flags *rf)
1736 __acquires(rq->lock)
1737 {
1738 raw_spin_lock(&rq->lock);
1739 rq_repin_lock(rq, rf);
1740 }
1741
1742 static inline void
1743 rq_unlock_irqrestore(struct rq *rq, struct rq_flags *rf)
1744 __releases(rq->lock)
1745 {
1746 rq_unpin_lock(rq, rf);
1747 raw_spin_unlock_irqrestore(&rq->lock, rf->flags);
1748 }
1749
1750 static inline void
1751 rq_unlock_irq(struct rq *rq, struct rq_flags *rf)
1752 __releases(rq->lock)
1753 {
1754 rq_unpin_lock(rq, rf);
1755 raw_spin_unlock_irq(&rq->lock);
1756 }
1757
1758 static inline void
1759 rq_unlock(struct rq *rq, struct rq_flags *rf)
1760 __releases(rq->lock)
1761 {
1762 rq_unpin_lock(rq, rf);
1763 raw_spin_unlock(&rq->lock);
1764 }
1765
1766 #ifdef CONFIG_SMP
1767 #ifdef CONFIG_PREEMPT
1768
1769 static inline void double_rq_lock(struct rq *rq1, struct rq *rq2);
1770
1771 /*
1772 * fair double_lock_balance: Safely acquires both rq->locks in a fair
1773 * way at the expense of forcing extra atomic operations in all
1774 * invocations. This assures that the double_lock is acquired using the
1775 * same underlying policy as the spinlock_t on this architecture, which
1776 * reduces latency compared to the unfair variant below. However, it
1777 * also adds more overhead and therefore may reduce throughput.
1778 */
1779 static inline int _double_lock_balance(struct rq *this_rq, struct rq *busiest)
1780 __releases(this_rq->lock)
1781 __acquires(busiest->lock)
1782 __acquires(this_rq->lock)
1783 {
1784 raw_spin_unlock(&this_rq->lock);
1785 double_rq_lock(this_rq, busiest);
1786
1787 return 1;
1788 }
1789
1790 #else
1791 /*
1792 * Unfair double_lock_balance: Optimizes throughput at the expense of
1793 * latency by eliminating extra atomic operations when the locks are
1794 * already in proper order on entry. This favors lower cpu-ids and will
1795 * grant the double lock to lower cpus over higher ids under contention,
1796 * regardless of entry order into the function.
1797 */
1798 static inline int _double_lock_balance(struct rq *this_rq, struct rq *busiest)
1799 __releases(this_rq->lock)
1800 __acquires(busiest->lock)
1801 __acquires(this_rq->lock)
1802 {
1803 int ret = 0;
1804
1805 if (unlikely(!raw_spin_trylock(&busiest->lock))) {
1806 if (busiest < this_rq) {
1807 raw_spin_unlock(&this_rq->lock);
1808 raw_spin_lock(&busiest->lock);
1809 raw_spin_lock_nested(&this_rq->lock,
1810 SINGLE_DEPTH_NESTING);
1811 ret = 1;
1812 } else
1813 raw_spin_lock_nested(&busiest->lock,
1814 SINGLE_DEPTH_NESTING);
1815 }
1816 return ret;
1817 }
1818
1819 #endif /* CONFIG_PREEMPT */
1820
1821 /*
1822 * double_lock_balance - lock the busiest runqueue, this_rq is locked already.
1823 */
1824 static inline int double_lock_balance(struct rq *this_rq, struct rq *busiest)
1825 {
1826 if (unlikely(!irqs_disabled())) {
1827 /* printk() doesn't work good under rq->lock */
1828 raw_spin_unlock(&this_rq->lock);
1829 BUG_ON(1);
1830 }
1831
1832 return _double_lock_balance(this_rq, busiest);
1833 }
1834
1835 static inline void double_unlock_balance(struct rq *this_rq, struct rq *busiest)
1836 __releases(busiest->lock)
1837 {
1838 raw_spin_unlock(&busiest->lock);
1839 lock_set_subclass(&this_rq->lock.dep_map, 0, _RET_IP_);
1840 }
1841
1842 static inline void double_lock(spinlock_t *l1, spinlock_t *l2)
1843 {
1844 if (l1 > l2)
1845 swap(l1, l2);
1846
1847 spin_lock(l1);
1848 spin_lock_nested(l2, SINGLE_DEPTH_NESTING);
1849 }
1850
1851 static inline void double_lock_irq(spinlock_t *l1, spinlock_t *l2)
1852 {
1853 if (l1 > l2)
1854 swap(l1, l2);
1855
1856 spin_lock_irq(l1);
1857 spin_lock_nested(l2, SINGLE_DEPTH_NESTING);
1858 }
1859
1860 static inline void double_raw_lock(raw_spinlock_t *l1, raw_spinlock_t *l2)
1861 {
1862 if (l1 > l2)
1863 swap(l1, l2);
1864
1865 raw_spin_lock(l1);
1866 raw_spin_lock_nested(l2, SINGLE_DEPTH_NESTING);
1867 }
1868
1869 /*
1870 * double_rq_lock - safely lock two runqueues
1871 *
1872 * Note this does not disable interrupts like task_rq_lock,
1873 * you need to do so manually before calling.
1874 */
1875 static inline void double_rq_lock(struct rq *rq1, struct rq *rq2)
1876 __acquires(rq1->lock)
1877 __acquires(rq2->lock)
1878 {
1879 BUG_ON(!irqs_disabled());
1880 if (rq1 == rq2) {
1881 raw_spin_lock(&rq1->lock);
1882 __acquire(rq2->lock); /* Fake it out ;) */
1883 } else {
1884 if (rq1 < rq2) {
1885 raw_spin_lock(&rq1->lock);
1886 raw_spin_lock_nested(&rq2->lock, SINGLE_DEPTH_NESTING);
1887 } else {
1888 raw_spin_lock(&rq2->lock);
1889 raw_spin_lock_nested(&rq1->lock, SINGLE_DEPTH_NESTING);
1890 }
1891 }
1892 }
1893
1894 /*
1895 * double_rq_unlock - safely unlock two runqueues
1896 *
1897 * Note this does not restore interrupts like task_rq_unlock,
1898 * you need to do so manually after calling.
1899 */
1900 static inline void double_rq_unlock(struct rq *rq1, struct rq *rq2)
1901 __releases(rq1->lock)
1902 __releases(rq2->lock)
1903 {
1904 raw_spin_unlock(&rq1->lock);
1905 if (rq1 != rq2)
1906 raw_spin_unlock(&rq2->lock);
1907 else
1908 __release(rq2->lock);
1909 }
1910
1911 extern void set_rq_online (struct rq *rq);
1912 extern void set_rq_offline(struct rq *rq);
1913 extern bool sched_smp_initialized;
1914
1915 #else /* CONFIG_SMP */
1916
1917 /*
1918 * double_rq_lock - safely lock two runqueues
1919 *
1920 * Note this does not disable interrupts like task_rq_lock,
1921 * you need to do so manually before calling.
1922 */
1923 static inline void double_rq_lock(struct rq *rq1, struct rq *rq2)
1924 __acquires(rq1->lock)
1925 __acquires(rq2->lock)
1926 {
1927 BUG_ON(!irqs_disabled());
1928 BUG_ON(rq1 != rq2);
1929 raw_spin_lock(&rq1->lock);
1930 __acquire(rq2->lock); /* Fake it out ;) */
1931 }
1932
1933 /*
1934 * double_rq_unlock - safely unlock two runqueues
1935 *
1936 * Note this does not restore interrupts like task_rq_unlock,
1937 * you need to do so manually after calling.
1938 */
1939 static inline void double_rq_unlock(struct rq *rq1, struct rq *rq2)
1940 __releases(rq1->lock)
1941 __releases(rq2->lock)
1942 {
1943 BUG_ON(rq1 != rq2);
1944 raw_spin_unlock(&rq1->lock);
1945 __release(rq2->lock);
1946 }
1947
1948 #endif
1949
1950 extern struct sched_entity *__pick_first_entity(struct cfs_rq *cfs_rq);
1951 extern struct sched_entity *__pick_last_entity(struct cfs_rq *cfs_rq);
1952
1953 #ifdef CONFIG_SCHED_DEBUG
1954 extern bool sched_debug_enabled;
1955
1956 extern void print_cfs_stats(struct seq_file *m, int cpu);
1957 extern void print_rt_stats(struct seq_file *m, int cpu);
1958 extern void print_dl_stats(struct seq_file *m, int cpu);
1959 extern void
1960 print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq);
1961 #ifdef CONFIG_NUMA_BALANCING
1962 extern void
1963 show_numa_stats(struct task_struct *p, struct seq_file *m);
1964 extern void
1965 print_numa_stats(struct seq_file *m, int node, unsigned long tsf,
1966 unsigned long tpf, unsigned long gsf, unsigned long gpf);
1967 #endif /* CONFIG_NUMA_BALANCING */
1968 #endif /* CONFIG_SCHED_DEBUG */
1969
1970 extern void init_cfs_rq(struct cfs_rq *cfs_rq);
1971 extern void init_rt_rq(struct rt_rq *rt_rq);
1972 extern void init_dl_rq(struct dl_rq *dl_rq);
1973
1974 extern void cfs_bandwidth_usage_inc(void);
1975 extern void cfs_bandwidth_usage_dec(void);
1976
1977 #ifdef CONFIG_NO_HZ_COMMON
1978 enum rq_nohz_flag_bits {
1979 NOHZ_TICK_STOPPED,
1980 NOHZ_BALANCE_KICK,
1981 };
1982
1983 #define nohz_flags(cpu) (&cpu_rq(cpu)->nohz_flags)
1984
1985 extern void nohz_balance_exit_idle(unsigned int cpu);
1986 #else
1987 static inline void nohz_balance_exit_idle(unsigned int cpu) { }
1988 #endif
1989
1990
1991 #ifdef CONFIG_SMP
1992 static inline
1993 void __dl_update(struct dl_bw *dl_b, s64 bw)
1994 {
1995 struct root_domain *rd = container_of(dl_b, struct root_domain, dl_bw);
1996 int i;
1997
1998 RCU_LOCKDEP_WARN(!rcu_read_lock_sched_held(),
1999 "sched RCU must be held");
2000 for_each_cpu_and(i, rd->span, cpu_active_mask) {
2001 struct rq *rq = cpu_rq(i);
2002
2003 rq->dl.extra_bw += bw;
2004 }
2005 }
2006 #else
2007 static inline
2008 void __dl_update(struct dl_bw *dl_b, s64 bw)
2009 {
2010 struct dl_rq *dl = container_of(dl_b, struct dl_rq, dl_bw);
2011
2012 dl->extra_bw += bw;
2013 }
2014 #endif
2015
2016
2017 #ifdef CONFIG_IRQ_TIME_ACCOUNTING
2018 struct irqtime {
2019 u64 total;
2020 u64 tick_delta;
2021 u64 irq_start_time;
2022 struct u64_stats_sync sync;
2023 };
2024
2025 DECLARE_PER_CPU(struct irqtime, cpu_irqtime);
2026
2027 /*
2028 * Returns the irqtime minus the softirq time computed by ksoftirqd.
2029 * Otherwise ksoftirqd's sum_exec_runtime is substracted its own runtime
2030 * and never move forward.
2031 */
2032 static inline u64 irq_time_read(int cpu)
2033 {
2034 struct irqtime *irqtime = &per_cpu(cpu_irqtime, cpu);
2035 unsigned int seq;
2036 u64 total;
2037
2038 do {
2039 seq = __u64_stats_fetch_begin(&irqtime->sync);
2040 total = irqtime->total;
2041 } while (__u64_stats_fetch_retry(&irqtime->sync, seq));
2042
2043 return total;
2044 }
2045 #endif /* CONFIG_IRQ_TIME_ACCOUNTING */
2046
2047 #ifdef CONFIG_CPU_FREQ
2048 DECLARE_PER_CPU(struct update_util_data *, cpufreq_update_util_data);
2049
2050 /**
2051 * cpufreq_update_util - Take a note about CPU utilization changes.
2052 * @rq: Runqueue to carry out the update for.
2053 * @flags: Update reason flags.
2054 *
2055 * This function is called by the scheduler on the CPU whose utilization is
2056 * being updated.
2057 *
2058 * It can only be called from RCU-sched read-side critical sections.
2059 *
2060 * The way cpufreq is currently arranged requires it to evaluate the CPU
2061 * performance state (frequency/voltage) on a regular basis to prevent it from
2062 * being stuck in a completely inadequate performance level for too long.
2063 * That is not guaranteed to happen if the updates are only triggered from CFS,
2064 * though, because they may not be coming in if RT or deadline tasks are active
2065 * all the time (or there are RT and DL tasks only).
2066 *
2067 * As a workaround for that issue, this function is called by the RT and DL
2068 * sched classes to trigger extra cpufreq updates to prevent it from stalling,
2069 * but that really is a band-aid. Going forward it should be replaced with
2070 * solutions targeted more specifically at RT and DL tasks.
2071 */
2072 static inline void cpufreq_update_util(struct rq *rq, unsigned int flags)
2073 {
2074 struct update_util_data *data;
2075
2076 data = rcu_dereference_sched(*per_cpu_ptr(&cpufreq_update_util_data,
2077 cpu_of(rq)));
2078 if (data)
2079 data->func(data, rq_clock(rq), flags);
2080 }
2081 #else
2082 static inline void cpufreq_update_util(struct rq *rq, unsigned int flags) {}
2083 #endif /* CONFIG_CPU_FREQ */
2084
2085 #ifdef arch_scale_freq_capacity
2086 #ifndef arch_scale_freq_invariant
2087 #define arch_scale_freq_invariant() (true)
2088 #endif
2089 #else /* arch_scale_freq_capacity */
2090 #define arch_scale_freq_invariant() (false)
2091 #endif