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Linux/kernel/sched/sched.h

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

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