xref: /openbmc/linux/kernel/sched/sched.h (revision 31b90347)
1 
2 #include <linux/sched.h>
3 #include <linux/sched/sysctl.h>
4 #include <linux/sched/rt.h>
5 #include <linux/mutex.h>
6 #include <linux/spinlock.h>
7 #include <linux/stop_machine.h>
8 #include <linux/tick.h>
9 #include <linux/slab.h>
10 
11 #include "cpupri.h"
12 #include "cpuacct.h"
13 
14 struct rq;
15 
16 extern __read_mostly int scheduler_running;
17 
18 extern unsigned long calc_load_update;
19 extern atomic_long_t calc_load_tasks;
20 
21 extern long calc_load_fold_active(struct rq *this_rq);
22 extern void update_cpu_load_active(struct rq *this_rq);
23 
24 /*
25  * Convert user-nice values [ -20 ... 0 ... 19 ]
26  * to static priority [ MAX_RT_PRIO..MAX_PRIO-1 ],
27  * and back.
28  */
29 #define NICE_TO_PRIO(nice)	(MAX_RT_PRIO + (nice) + 20)
30 #define PRIO_TO_NICE(prio)	((prio) - MAX_RT_PRIO - 20)
31 #define TASK_NICE(p)		PRIO_TO_NICE((p)->static_prio)
32 
33 /*
34  * 'User priority' is the nice value converted to something we
35  * can work with better when scaling various scheduler parameters,
36  * it's a [ 0 ... 39 ] range.
37  */
38 #define USER_PRIO(p)		((p)-MAX_RT_PRIO)
39 #define TASK_USER_PRIO(p)	USER_PRIO((p)->static_prio)
40 #define MAX_USER_PRIO		(USER_PRIO(MAX_PRIO))
41 
42 /*
43  * Helpers for converting nanosecond timing to jiffy resolution
44  */
45 #define NS_TO_JIFFIES(TIME)	((unsigned long)(TIME) / (NSEC_PER_SEC / HZ))
46 
47 /*
48  * Increase resolution of nice-level calculations for 64-bit architectures.
49  * The extra resolution improves shares distribution and load balancing of
50  * low-weight task groups (eg. nice +19 on an autogroup), deeper taskgroup
51  * hierarchies, especially on larger systems. This is not a user-visible change
52  * and does not change the user-interface for setting shares/weights.
53  *
54  * We increase resolution only if we have enough bits to allow this increased
55  * resolution (i.e. BITS_PER_LONG > 32). The costs for increasing resolution
56  * when BITS_PER_LONG <= 32 are pretty high and the returns do not justify the
57  * increased costs.
58  */
59 #if 0 /* BITS_PER_LONG > 32 -- currently broken: it increases power usage under light load  */
60 # define SCHED_LOAD_RESOLUTION	10
61 # define scale_load(w)		((w) << SCHED_LOAD_RESOLUTION)
62 # define scale_load_down(w)	((w) >> SCHED_LOAD_RESOLUTION)
63 #else
64 # define SCHED_LOAD_RESOLUTION	0
65 # define scale_load(w)		(w)
66 # define scale_load_down(w)	(w)
67 #endif
68 
69 #define SCHED_LOAD_SHIFT	(10 + SCHED_LOAD_RESOLUTION)
70 #define SCHED_LOAD_SCALE	(1L << SCHED_LOAD_SHIFT)
71 
72 #define NICE_0_LOAD		SCHED_LOAD_SCALE
73 #define NICE_0_SHIFT		SCHED_LOAD_SHIFT
74 
75 /*
76  * These are the 'tuning knobs' of the scheduler:
77  */
78 
79 /*
80  * single value that denotes runtime == period, ie unlimited time.
81  */
82 #define RUNTIME_INF	((u64)~0ULL)
83 
84 static inline int rt_policy(int policy)
85 {
86 	if (policy == SCHED_FIFO || policy == SCHED_RR)
87 		return 1;
88 	return 0;
89 }
90 
91 static inline int task_has_rt_policy(struct task_struct *p)
92 {
93 	return rt_policy(p->policy);
94 }
95 
96 /*
97  * This is the priority-queue data structure of the RT scheduling class:
98  */
99 struct rt_prio_array {
100 	DECLARE_BITMAP(bitmap, MAX_RT_PRIO+1); /* include 1 bit for delimiter */
101 	struct list_head queue[MAX_RT_PRIO];
102 };
103 
104 struct rt_bandwidth {
105 	/* nests inside the rq lock: */
106 	raw_spinlock_t		rt_runtime_lock;
107 	ktime_t			rt_period;
108 	u64			rt_runtime;
109 	struct hrtimer		rt_period_timer;
110 };
111 
112 extern struct mutex sched_domains_mutex;
113 
114 #ifdef CONFIG_CGROUP_SCHED
115 
116 #include <linux/cgroup.h>
117 
118 struct cfs_rq;
119 struct rt_rq;
120 
121 extern struct list_head task_groups;
122 
123 struct cfs_bandwidth {
124 #ifdef CONFIG_CFS_BANDWIDTH
125 	raw_spinlock_t lock;
126 	ktime_t period;
127 	u64 quota, runtime;
128 	s64 hierarchal_quota;
129 	u64 runtime_expires;
130 
131 	int idle, timer_active;
132 	struct hrtimer period_timer, slack_timer;
133 	struct list_head throttled_cfs_rq;
134 
135 	/* statistics */
136 	int nr_periods, nr_throttled;
137 	u64 throttled_time;
138 #endif
139 };
140 
141 /* task group related information */
142 struct task_group {
143 	struct cgroup_subsys_state css;
144 
145 #ifdef CONFIG_FAIR_GROUP_SCHED
146 	/* schedulable entities of this group on each cpu */
147 	struct sched_entity **se;
148 	/* runqueue "owned" by this group on each cpu */
149 	struct cfs_rq **cfs_rq;
150 	unsigned long shares;
151 
152 #ifdef	CONFIG_SMP
153 	atomic_long_t load_avg;
154 	atomic_t runnable_avg;
155 #endif
156 #endif
157 
158 #ifdef CONFIG_RT_GROUP_SCHED
159 	struct sched_rt_entity **rt_se;
160 	struct rt_rq **rt_rq;
161 
162 	struct rt_bandwidth rt_bandwidth;
163 #endif
164 
165 	struct rcu_head rcu;
166 	struct list_head list;
167 
168 	struct task_group *parent;
169 	struct list_head siblings;
170 	struct list_head children;
171 
172 #ifdef CONFIG_SCHED_AUTOGROUP
173 	struct autogroup *autogroup;
174 #endif
175 
176 	struct cfs_bandwidth cfs_bandwidth;
177 };
178 
179 #ifdef CONFIG_FAIR_GROUP_SCHED
180 #define ROOT_TASK_GROUP_LOAD	NICE_0_LOAD
181 
182 /*
183  * A weight of 0 or 1 can cause arithmetics problems.
184  * A weight of a cfs_rq is the sum of weights of which entities
185  * are queued on this cfs_rq, so a weight of a entity should not be
186  * too large, so as the shares value of a task group.
187  * (The default weight is 1024 - so there's no practical
188  *  limitation from this.)
189  */
190 #define MIN_SHARES	(1UL <<  1)
191 #define MAX_SHARES	(1UL << 18)
192 #endif
193 
194 typedef int (*tg_visitor)(struct task_group *, void *);
195 
196 extern int walk_tg_tree_from(struct task_group *from,
197 			     tg_visitor down, tg_visitor up, void *data);
198 
199 /*
200  * Iterate the full tree, calling @down when first entering a node and @up when
201  * leaving it for the final time.
202  *
203  * Caller must hold rcu_lock or sufficient equivalent.
204  */
205 static inline int walk_tg_tree(tg_visitor down, tg_visitor up, void *data)
206 {
207 	return walk_tg_tree_from(&root_task_group, down, up, data);
208 }
209 
210 extern int tg_nop(struct task_group *tg, void *data);
211 
212 extern void free_fair_sched_group(struct task_group *tg);
213 extern int alloc_fair_sched_group(struct task_group *tg, struct task_group *parent);
214 extern void unregister_fair_sched_group(struct task_group *tg, int cpu);
215 extern void init_tg_cfs_entry(struct task_group *tg, struct cfs_rq *cfs_rq,
216 			struct sched_entity *se, int cpu,
217 			struct sched_entity *parent);
218 extern void init_cfs_bandwidth(struct cfs_bandwidth *cfs_b);
219 extern int sched_group_set_shares(struct task_group *tg, unsigned long shares);
220 
221 extern void __refill_cfs_bandwidth_runtime(struct cfs_bandwidth *cfs_b);
222 extern void __start_cfs_bandwidth(struct cfs_bandwidth *cfs_b);
223 extern void unthrottle_cfs_rq(struct cfs_rq *cfs_rq);
224 
225 extern void free_rt_sched_group(struct task_group *tg);
226 extern int alloc_rt_sched_group(struct task_group *tg, struct task_group *parent);
227 extern void init_tg_rt_entry(struct task_group *tg, struct rt_rq *rt_rq,
228 		struct sched_rt_entity *rt_se, int cpu,
229 		struct sched_rt_entity *parent);
230 
231 extern struct task_group *sched_create_group(struct task_group *parent);
232 extern void sched_online_group(struct task_group *tg,
233 			       struct task_group *parent);
234 extern void sched_destroy_group(struct task_group *tg);
235 extern void sched_offline_group(struct task_group *tg);
236 
237 extern void sched_move_task(struct task_struct *tsk);
238 
239 #ifdef CONFIG_FAIR_GROUP_SCHED
240 extern int sched_group_set_shares(struct task_group *tg, unsigned long shares);
241 #endif
242 
243 #else /* CONFIG_CGROUP_SCHED */
244 
245 struct cfs_bandwidth { };
246 
247 #endif	/* CONFIG_CGROUP_SCHED */
248 
249 /* CFS-related fields in a runqueue */
250 struct cfs_rq {
251 	struct load_weight load;
252 	unsigned int nr_running, h_nr_running;
253 
254 	u64 exec_clock;
255 	u64 min_vruntime;
256 #ifndef CONFIG_64BIT
257 	u64 min_vruntime_copy;
258 #endif
259 
260 	struct rb_root tasks_timeline;
261 	struct rb_node *rb_leftmost;
262 
263 	/*
264 	 * 'curr' points to currently running entity on this cfs_rq.
265 	 * It is set to NULL otherwise (i.e when none are currently running).
266 	 */
267 	struct sched_entity *curr, *next, *last, *skip;
268 
269 #ifdef	CONFIG_SCHED_DEBUG
270 	unsigned int nr_spread_over;
271 #endif
272 
273 #ifdef CONFIG_SMP
274 	/*
275 	 * CFS Load tracking
276 	 * Under CFS, load is tracked on a per-entity basis and aggregated up.
277 	 * This allows for the description of both thread and group usage (in
278 	 * the FAIR_GROUP_SCHED case).
279 	 */
280 	unsigned long runnable_load_avg, blocked_load_avg;
281 	atomic64_t decay_counter;
282 	u64 last_decay;
283 	atomic_long_t removed_load;
284 
285 #ifdef CONFIG_FAIR_GROUP_SCHED
286 	/* Required to track per-cpu representation of a task_group */
287 	u32 tg_runnable_contrib;
288 	unsigned long tg_load_contrib;
289 
290 	/*
291 	 *   h_load = weight * f(tg)
292 	 *
293 	 * Where f(tg) is the recursive weight fraction assigned to
294 	 * this group.
295 	 */
296 	unsigned long h_load;
297 	u64 last_h_load_update;
298 	struct sched_entity *h_load_next;
299 #endif /* CONFIG_FAIR_GROUP_SCHED */
300 #endif /* CONFIG_SMP */
301 
302 #ifdef CONFIG_FAIR_GROUP_SCHED
303 	struct rq *rq;	/* cpu runqueue to which this cfs_rq is attached */
304 
305 	/*
306 	 * leaf cfs_rqs are those that hold tasks (lowest schedulable entity in
307 	 * a hierarchy). Non-leaf lrqs hold other higher schedulable entities
308 	 * (like users, containers etc.)
309 	 *
310 	 * leaf_cfs_rq_list ties together list of leaf cfs_rq's in a cpu. This
311 	 * list is used during load balance.
312 	 */
313 	int on_list;
314 	struct list_head leaf_cfs_rq_list;
315 	struct task_group *tg;	/* group that "owns" this runqueue */
316 
317 #ifdef CONFIG_CFS_BANDWIDTH
318 	int runtime_enabled;
319 	u64 runtime_expires;
320 	s64 runtime_remaining;
321 
322 	u64 throttled_clock, throttled_clock_task;
323 	u64 throttled_clock_task_time;
324 	int throttled, throttle_count;
325 	struct list_head throttled_list;
326 #endif /* CONFIG_CFS_BANDWIDTH */
327 #endif /* CONFIG_FAIR_GROUP_SCHED */
328 };
329 
330 static inline int rt_bandwidth_enabled(void)
331 {
332 	return sysctl_sched_rt_runtime >= 0;
333 }
334 
335 /* Real-Time classes' related field in a runqueue: */
336 struct rt_rq {
337 	struct rt_prio_array active;
338 	unsigned int rt_nr_running;
339 #if defined CONFIG_SMP || defined CONFIG_RT_GROUP_SCHED
340 	struct {
341 		int curr; /* highest queued rt task prio */
342 #ifdef CONFIG_SMP
343 		int next; /* next highest */
344 #endif
345 	} highest_prio;
346 #endif
347 #ifdef CONFIG_SMP
348 	unsigned long rt_nr_migratory;
349 	unsigned long rt_nr_total;
350 	int overloaded;
351 	struct plist_head pushable_tasks;
352 #endif
353 	int rt_throttled;
354 	u64 rt_time;
355 	u64 rt_runtime;
356 	/* Nests inside the rq lock: */
357 	raw_spinlock_t rt_runtime_lock;
358 
359 #ifdef CONFIG_RT_GROUP_SCHED
360 	unsigned long rt_nr_boosted;
361 
362 	struct rq *rq;
363 	struct task_group *tg;
364 #endif
365 };
366 
367 #ifdef CONFIG_SMP
368 
369 /*
370  * We add the notion of a root-domain which will be used to define per-domain
371  * variables. Each exclusive cpuset essentially defines an island domain by
372  * fully partitioning the member cpus from any other cpuset. Whenever a new
373  * exclusive cpuset is created, we also create and attach a new root-domain
374  * object.
375  *
376  */
377 struct root_domain {
378 	atomic_t refcount;
379 	atomic_t rto_count;
380 	struct rcu_head rcu;
381 	cpumask_var_t span;
382 	cpumask_var_t online;
383 
384 	/*
385 	 * The "RT overload" flag: it gets set if a CPU has more than
386 	 * one runnable RT task.
387 	 */
388 	cpumask_var_t rto_mask;
389 	struct cpupri cpupri;
390 };
391 
392 extern struct root_domain def_root_domain;
393 
394 #endif /* CONFIG_SMP */
395 
396 /*
397  * This is the main, per-CPU runqueue data structure.
398  *
399  * Locking rule: those places that want to lock multiple runqueues
400  * (such as the load balancing or the thread migration code), lock
401  * acquire operations must be ordered by ascending &runqueue.
402  */
403 struct rq {
404 	/* runqueue lock: */
405 	raw_spinlock_t lock;
406 
407 	/*
408 	 * nr_running and cpu_load should be in the same cacheline because
409 	 * remote CPUs use both these fields when doing load calculation.
410 	 */
411 	unsigned int nr_running;
412 #ifdef CONFIG_NUMA_BALANCING
413 	unsigned int nr_numa_running;
414 	unsigned int nr_preferred_running;
415 #endif
416 	#define CPU_LOAD_IDX_MAX 5
417 	unsigned long cpu_load[CPU_LOAD_IDX_MAX];
418 	unsigned long last_load_update_tick;
419 #ifdef CONFIG_NO_HZ_COMMON
420 	u64 nohz_stamp;
421 	unsigned long nohz_flags;
422 #endif
423 #ifdef CONFIG_NO_HZ_FULL
424 	unsigned long last_sched_tick;
425 #endif
426 	int skip_clock_update;
427 
428 	/* capture load from *all* tasks on this cpu: */
429 	struct load_weight load;
430 	unsigned long nr_load_updates;
431 	u64 nr_switches;
432 
433 	struct cfs_rq cfs;
434 	struct rt_rq rt;
435 
436 #ifdef CONFIG_FAIR_GROUP_SCHED
437 	/* list of leaf cfs_rq on this cpu: */
438 	struct list_head leaf_cfs_rq_list;
439 #endif /* CONFIG_FAIR_GROUP_SCHED */
440 
441 #ifdef CONFIG_RT_GROUP_SCHED
442 	struct list_head leaf_rt_rq_list;
443 #endif
444 
445 	/*
446 	 * This is part of a global counter where only the total sum
447 	 * over all CPUs matters. A task can increase this counter on
448 	 * one CPU and if it got migrated afterwards it may decrease
449 	 * it on another CPU. Always updated under the runqueue lock:
450 	 */
451 	unsigned long nr_uninterruptible;
452 
453 	struct task_struct *curr, *idle, *stop;
454 	unsigned long next_balance;
455 	struct mm_struct *prev_mm;
456 
457 	u64 clock;
458 	u64 clock_task;
459 
460 	atomic_t nr_iowait;
461 
462 #ifdef CONFIG_SMP
463 	struct root_domain *rd;
464 	struct sched_domain *sd;
465 
466 	unsigned long cpu_power;
467 
468 	unsigned char idle_balance;
469 	/* For active balancing */
470 	int post_schedule;
471 	int active_balance;
472 	int push_cpu;
473 	struct cpu_stop_work active_balance_work;
474 	/* cpu of this runqueue: */
475 	int cpu;
476 	int online;
477 
478 	struct list_head cfs_tasks;
479 
480 	u64 rt_avg;
481 	u64 age_stamp;
482 	u64 idle_stamp;
483 	u64 avg_idle;
484 
485 	/* This is used to determine avg_idle's max value */
486 	u64 max_idle_balance_cost;
487 #endif
488 
489 #ifdef CONFIG_IRQ_TIME_ACCOUNTING
490 	u64 prev_irq_time;
491 #endif
492 #ifdef CONFIG_PARAVIRT
493 	u64 prev_steal_time;
494 #endif
495 #ifdef CONFIG_PARAVIRT_TIME_ACCOUNTING
496 	u64 prev_steal_time_rq;
497 #endif
498 
499 	/* calc_load related fields */
500 	unsigned long calc_load_update;
501 	long calc_load_active;
502 
503 #ifdef CONFIG_SCHED_HRTICK
504 #ifdef CONFIG_SMP
505 	int hrtick_csd_pending;
506 	struct call_single_data hrtick_csd;
507 #endif
508 	struct hrtimer hrtick_timer;
509 #endif
510 
511 #ifdef CONFIG_SCHEDSTATS
512 	/* latency stats */
513 	struct sched_info rq_sched_info;
514 	unsigned long long rq_cpu_time;
515 	/* could above be rq->cfs_rq.exec_clock + rq->rt_rq.rt_runtime ? */
516 
517 	/* sys_sched_yield() stats */
518 	unsigned int yld_count;
519 
520 	/* schedule() stats */
521 	unsigned int sched_count;
522 	unsigned int sched_goidle;
523 
524 	/* try_to_wake_up() stats */
525 	unsigned int ttwu_count;
526 	unsigned int ttwu_local;
527 #endif
528 
529 #ifdef CONFIG_SMP
530 	struct llist_head wake_list;
531 #endif
532 
533 	struct sched_avg avg;
534 };
535 
536 static inline int cpu_of(struct rq *rq)
537 {
538 #ifdef CONFIG_SMP
539 	return rq->cpu;
540 #else
541 	return 0;
542 #endif
543 }
544 
545 DECLARE_PER_CPU(struct rq, runqueues);
546 
547 #define cpu_rq(cpu)		(&per_cpu(runqueues, (cpu)))
548 #define this_rq()		(&__get_cpu_var(runqueues))
549 #define task_rq(p)		cpu_rq(task_cpu(p))
550 #define cpu_curr(cpu)		(cpu_rq(cpu)->curr)
551 #define raw_rq()		(&__raw_get_cpu_var(runqueues))
552 
553 static inline u64 rq_clock(struct rq *rq)
554 {
555 	return rq->clock;
556 }
557 
558 static inline u64 rq_clock_task(struct rq *rq)
559 {
560 	return rq->clock_task;
561 }
562 
563 #ifdef CONFIG_NUMA_BALANCING
564 extern void sched_setnuma(struct task_struct *p, int node);
565 extern int migrate_task_to(struct task_struct *p, int cpu);
566 extern int migrate_swap(struct task_struct *, struct task_struct *);
567 #endif /* CONFIG_NUMA_BALANCING */
568 
569 #ifdef CONFIG_SMP
570 
571 #define rcu_dereference_check_sched_domain(p) \
572 	rcu_dereference_check((p), \
573 			      lockdep_is_held(&sched_domains_mutex))
574 
575 /*
576  * The domain tree (rq->sd) is protected by RCU's quiescent state transition.
577  * See detach_destroy_domains: synchronize_sched for details.
578  *
579  * The domain tree of any CPU may only be accessed from within
580  * preempt-disabled sections.
581  */
582 #define for_each_domain(cpu, __sd) \
583 	for (__sd = rcu_dereference_check_sched_domain(cpu_rq(cpu)->sd); \
584 			__sd; __sd = __sd->parent)
585 
586 #define for_each_lower_domain(sd) for (; sd; sd = sd->child)
587 
588 /**
589  * highest_flag_domain - Return highest sched_domain containing flag.
590  * @cpu:	The cpu whose highest level of sched domain is to
591  *		be returned.
592  * @flag:	The flag to check for the highest sched_domain
593  *		for the given cpu.
594  *
595  * Returns the highest sched_domain of a cpu which contains the given flag.
596  */
597 static inline struct sched_domain *highest_flag_domain(int cpu, int flag)
598 {
599 	struct sched_domain *sd, *hsd = NULL;
600 
601 	for_each_domain(cpu, sd) {
602 		if (!(sd->flags & flag))
603 			break;
604 		hsd = sd;
605 	}
606 
607 	return hsd;
608 }
609 
610 static inline struct sched_domain *lowest_flag_domain(int cpu, int flag)
611 {
612 	struct sched_domain *sd;
613 
614 	for_each_domain(cpu, sd) {
615 		if (sd->flags & flag)
616 			break;
617 	}
618 
619 	return sd;
620 }
621 
622 DECLARE_PER_CPU(struct sched_domain *, sd_llc);
623 DECLARE_PER_CPU(int, sd_llc_size);
624 DECLARE_PER_CPU(int, sd_llc_id);
625 DECLARE_PER_CPU(struct sched_domain *, sd_numa);
626 DECLARE_PER_CPU(struct sched_domain *, sd_busy);
627 DECLARE_PER_CPU(struct sched_domain *, sd_asym);
628 
629 struct sched_group_power {
630 	atomic_t ref;
631 	/*
632 	 * CPU power of this group, SCHED_LOAD_SCALE being max power for a
633 	 * single CPU.
634 	 */
635 	unsigned int power, power_orig;
636 	unsigned long next_update;
637 	int imbalance; /* XXX unrelated to power but shared group state */
638 	/*
639 	 * Number of busy cpus in this group.
640 	 */
641 	atomic_t nr_busy_cpus;
642 
643 	unsigned long cpumask[0]; /* iteration mask */
644 };
645 
646 struct sched_group {
647 	struct sched_group *next;	/* Must be a circular list */
648 	atomic_t ref;
649 
650 	unsigned int group_weight;
651 	struct sched_group_power *sgp;
652 
653 	/*
654 	 * The CPUs this group covers.
655 	 *
656 	 * NOTE: this field is variable length. (Allocated dynamically
657 	 * by attaching extra space to the end of the structure,
658 	 * depending on how many CPUs the kernel has booted up with)
659 	 */
660 	unsigned long cpumask[0];
661 };
662 
663 static inline struct cpumask *sched_group_cpus(struct sched_group *sg)
664 {
665 	return to_cpumask(sg->cpumask);
666 }
667 
668 /*
669  * cpumask masking which cpus in the group are allowed to iterate up the domain
670  * tree.
671  */
672 static inline struct cpumask *sched_group_mask(struct sched_group *sg)
673 {
674 	return to_cpumask(sg->sgp->cpumask);
675 }
676 
677 /**
678  * group_first_cpu - Returns the first cpu in the cpumask of a sched_group.
679  * @group: The group whose first cpu is to be returned.
680  */
681 static inline unsigned int group_first_cpu(struct sched_group *group)
682 {
683 	return cpumask_first(sched_group_cpus(group));
684 }
685 
686 extern int group_balance_cpu(struct sched_group *sg);
687 
688 #endif /* CONFIG_SMP */
689 
690 #include "stats.h"
691 #include "auto_group.h"
692 
693 #ifdef CONFIG_CGROUP_SCHED
694 
695 /*
696  * Return the group to which this tasks belongs.
697  *
698  * We cannot use task_css() and friends because the cgroup subsystem
699  * changes that value before the cgroup_subsys::attach() method is called,
700  * therefore we cannot pin it and might observe the wrong value.
701  *
702  * The same is true for autogroup's p->signal->autogroup->tg, the autogroup
703  * core changes this before calling sched_move_task().
704  *
705  * Instead we use a 'copy' which is updated from sched_move_task() while
706  * holding both task_struct::pi_lock and rq::lock.
707  */
708 static inline struct task_group *task_group(struct task_struct *p)
709 {
710 	return p->sched_task_group;
711 }
712 
713 /* Change a task's cfs_rq and parent entity if it moves across CPUs/groups */
714 static inline void set_task_rq(struct task_struct *p, unsigned int cpu)
715 {
716 #if defined(CONFIG_FAIR_GROUP_SCHED) || defined(CONFIG_RT_GROUP_SCHED)
717 	struct task_group *tg = task_group(p);
718 #endif
719 
720 #ifdef CONFIG_FAIR_GROUP_SCHED
721 	p->se.cfs_rq = tg->cfs_rq[cpu];
722 	p->se.parent = tg->se[cpu];
723 #endif
724 
725 #ifdef CONFIG_RT_GROUP_SCHED
726 	p->rt.rt_rq  = tg->rt_rq[cpu];
727 	p->rt.parent = tg->rt_se[cpu];
728 #endif
729 }
730 
731 #else /* CONFIG_CGROUP_SCHED */
732 
733 static inline void set_task_rq(struct task_struct *p, unsigned int cpu) { }
734 static inline struct task_group *task_group(struct task_struct *p)
735 {
736 	return NULL;
737 }
738 
739 #endif /* CONFIG_CGROUP_SCHED */
740 
741 static inline void __set_task_cpu(struct task_struct *p, unsigned int cpu)
742 {
743 	set_task_rq(p, cpu);
744 #ifdef CONFIG_SMP
745 	/*
746 	 * After ->cpu is set up to a new value, task_rq_lock(p, ...) can be
747 	 * successfuly executed on another CPU. We must ensure that updates of
748 	 * per-task data have been completed by this moment.
749 	 */
750 	smp_wmb();
751 	task_thread_info(p)->cpu = cpu;
752 	p->wake_cpu = cpu;
753 #endif
754 }
755 
756 /*
757  * Tunables that become constants when CONFIG_SCHED_DEBUG is off:
758  */
759 #ifdef CONFIG_SCHED_DEBUG
760 # include <linux/static_key.h>
761 # define const_debug __read_mostly
762 #else
763 # define const_debug const
764 #endif
765 
766 extern const_debug unsigned int sysctl_sched_features;
767 
768 #define SCHED_FEAT(name, enabled)	\
769 	__SCHED_FEAT_##name ,
770 
771 enum {
772 #include "features.h"
773 	__SCHED_FEAT_NR,
774 };
775 
776 #undef SCHED_FEAT
777 
778 #if defined(CONFIG_SCHED_DEBUG) && defined(HAVE_JUMP_LABEL)
779 static __always_inline bool static_branch__true(struct static_key *key)
780 {
781 	return static_key_true(key); /* Not out of line branch. */
782 }
783 
784 static __always_inline bool static_branch__false(struct static_key *key)
785 {
786 	return static_key_false(key); /* Out of line branch. */
787 }
788 
789 #define SCHED_FEAT(name, enabled)					\
790 static __always_inline bool static_branch_##name(struct static_key *key) \
791 {									\
792 	return static_branch__##enabled(key);				\
793 }
794 
795 #include "features.h"
796 
797 #undef SCHED_FEAT
798 
799 extern struct static_key sched_feat_keys[__SCHED_FEAT_NR];
800 #define sched_feat(x) (static_branch_##x(&sched_feat_keys[__SCHED_FEAT_##x]))
801 #else /* !(SCHED_DEBUG && HAVE_JUMP_LABEL) */
802 #define sched_feat(x) (sysctl_sched_features & (1UL << __SCHED_FEAT_##x))
803 #endif /* SCHED_DEBUG && HAVE_JUMP_LABEL */
804 
805 #ifdef CONFIG_NUMA_BALANCING
806 #define sched_feat_numa(x) sched_feat(x)
807 #ifdef CONFIG_SCHED_DEBUG
808 #define numabalancing_enabled sched_feat_numa(NUMA)
809 #else
810 extern bool numabalancing_enabled;
811 #endif /* CONFIG_SCHED_DEBUG */
812 #else
813 #define sched_feat_numa(x) (0)
814 #define numabalancing_enabled (0)
815 #endif /* CONFIG_NUMA_BALANCING */
816 
817 static inline u64 global_rt_period(void)
818 {
819 	return (u64)sysctl_sched_rt_period * NSEC_PER_USEC;
820 }
821 
822 static inline u64 global_rt_runtime(void)
823 {
824 	if (sysctl_sched_rt_runtime < 0)
825 		return RUNTIME_INF;
826 
827 	return (u64)sysctl_sched_rt_runtime * NSEC_PER_USEC;
828 }
829 
830 
831 
832 static inline int task_current(struct rq *rq, struct task_struct *p)
833 {
834 	return rq->curr == p;
835 }
836 
837 static inline int task_running(struct rq *rq, struct task_struct *p)
838 {
839 #ifdef CONFIG_SMP
840 	return p->on_cpu;
841 #else
842 	return task_current(rq, p);
843 #endif
844 }
845 
846 
847 #ifndef prepare_arch_switch
848 # define prepare_arch_switch(next)	do { } while (0)
849 #endif
850 #ifndef finish_arch_switch
851 # define finish_arch_switch(prev)	do { } while (0)
852 #endif
853 #ifndef finish_arch_post_lock_switch
854 # define finish_arch_post_lock_switch()	do { } while (0)
855 #endif
856 
857 #ifndef __ARCH_WANT_UNLOCKED_CTXSW
858 static inline void prepare_lock_switch(struct rq *rq, struct task_struct *next)
859 {
860 #ifdef CONFIG_SMP
861 	/*
862 	 * We can optimise this out completely for !SMP, because the
863 	 * SMP rebalancing from interrupt is the only thing that cares
864 	 * here.
865 	 */
866 	next->on_cpu = 1;
867 #endif
868 }
869 
870 static inline void finish_lock_switch(struct rq *rq, struct task_struct *prev)
871 {
872 #ifdef CONFIG_SMP
873 	/*
874 	 * After ->on_cpu is cleared, the task can be moved to a different CPU.
875 	 * We must ensure this doesn't happen until the switch is completely
876 	 * finished.
877 	 */
878 	smp_wmb();
879 	prev->on_cpu = 0;
880 #endif
881 #ifdef CONFIG_DEBUG_SPINLOCK
882 	/* this is a valid case when another task releases the spinlock */
883 	rq->lock.owner = current;
884 #endif
885 	/*
886 	 * If we are tracking spinlock dependencies then we have to
887 	 * fix up the runqueue lock - which gets 'carried over' from
888 	 * prev into current:
889 	 */
890 	spin_acquire(&rq->lock.dep_map, 0, 0, _THIS_IP_);
891 
892 	raw_spin_unlock_irq(&rq->lock);
893 }
894 
895 #else /* __ARCH_WANT_UNLOCKED_CTXSW */
896 static inline void prepare_lock_switch(struct rq *rq, struct task_struct *next)
897 {
898 #ifdef CONFIG_SMP
899 	/*
900 	 * We can optimise this out completely for !SMP, because the
901 	 * SMP rebalancing from interrupt is the only thing that cares
902 	 * here.
903 	 */
904 	next->on_cpu = 1;
905 #endif
906 	raw_spin_unlock(&rq->lock);
907 }
908 
909 static inline void finish_lock_switch(struct rq *rq, struct task_struct *prev)
910 {
911 #ifdef CONFIG_SMP
912 	/*
913 	 * After ->on_cpu is cleared, the task can be moved to a different CPU.
914 	 * We must ensure this doesn't happen until the switch is completely
915 	 * finished.
916 	 */
917 	smp_wmb();
918 	prev->on_cpu = 0;
919 #endif
920 	local_irq_enable();
921 }
922 #endif /* __ARCH_WANT_UNLOCKED_CTXSW */
923 
924 /*
925  * wake flags
926  */
927 #define WF_SYNC		0x01		/* waker goes to sleep after wakeup */
928 #define WF_FORK		0x02		/* child wakeup after fork */
929 #define WF_MIGRATED	0x4		/* internal use, task got migrated */
930 
931 /*
932  * To aid in avoiding the subversion of "niceness" due to uneven distribution
933  * of tasks with abnormal "nice" values across CPUs the contribution that
934  * each task makes to its run queue's load is weighted according to its
935  * scheduling class and "nice" value. For SCHED_NORMAL tasks this is just a
936  * scaled version of the new time slice allocation that they receive on time
937  * slice expiry etc.
938  */
939 
940 #define WEIGHT_IDLEPRIO                3
941 #define WMULT_IDLEPRIO         1431655765
942 
943 /*
944  * Nice levels are multiplicative, with a gentle 10% change for every
945  * nice level changed. I.e. when a CPU-bound task goes from nice 0 to
946  * nice 1, it will get ~10% less CPU time than another CPU-bound task
947  * that remained on nice 0.
948  *
949  * The "10% effect" is relative and cumulative: from _any_ nice level,
950  * if you go up 1 level, it's -10% CPU usage, if you go down 1 level
951  * it's +10% CPU usage. (to achieve that we use a multiplier of 1.25.
952  * If a task goes up by ~10% and another task goes down by ~10% then
953  * the relative distance between them is ~25%.)
954  */
955 static const int prio_to_weight[40] = {
956  /* -20 */     88761,     71755,     56483,     46273,     36291,
957  /* -15 */     29154,     23254,     18705,     14949,     11916,
958  /* -10 */      9548,      7620,      6100,      4904,      3906,
959  /*  -5 */      3121,      2501,      1991,      1586,      1277,
960  /*   0 */      1024,       820,       655,       526,       423,
961  /*   5 */       335,       272,       215,       172,       137,
962  /*  10 */       110,        87,        70,        56,        45,
963  /*  15 */        36,        29,        23,        18,        15,
964 };
965 
966 /*
967  * Inverse (2^32/x) values of the prio_to_weight[] array, precalculated.
968  *
969  * In cases where the weight does not change often, we can use the
970  * precalculated inverse to speed up arithmetics by turning divisions
971  * into multiplications:
972  */
973 static const u32 prio_to_wmult[40] = {
974  /* -20 */     48388,     59856,     76040,     92818,    118348,
975  /* -15 */    147320,    184698,    229616,    287308,    360437,
976  /* -10 */    449829,    563644,    704093,    875809,   1099582,
977  /*  -5 */   1376151,   1717300,   2157191,   2708050,   3363326,
978  /*   0 */   4194304,   5237765,   6557202,   8165337,  10153587,
979  /*   5 */  12820798,  15790321,  19976592,  24970740,  31350126,
980  /*  10 */  39045157,  49367440,  61356676,  76695844,  95443717,
981  /*  15 */ 119304647, 148102320, 186737708, 238609294, 286331153,
982 };
983 
984 #define ENQUEUE_WAKEUP		1
985 #define ENQUEUE_HEAD		2
986 #ifdef CONFIG_SMP
987 #define ENQUEUE_WAKING		4	/* sched_class::task_waking was called */
988 #else
989 #define ENQUEUE_WAKING		0
990 #endif
991 
992 #define DEQUEUE_SLEEP		1
993 
994 struct sched_class {
995 	const struct sched_class *next;
996 
997 	void (*enqueue_task) (struct rq *rq, struct task_struct *p, int flags);
998 	void (*dequeue_task) (struct rq *rq, struct task_struct *p, int flags);
999 	void (*yield_task) (struct rq *rq);
1000 	bool (*yield_to_task) (struct rq *rq, struct task_struct *p, bool preempt);
1001 
1002 	void (*check_preempt_curr) (struct rq *rq, struct task_struct *p, int flags);
1003 
1004 	struct task_struct * (*pick_next_task) (struct rq *rq);
1005 	void (*put_prev_task) (struct rq *rq, struct task_struct *p);
1006 
1007 #ifdef CONFIG_SMP
1008 	int  (*select_task_rq)(struct task_struct *p, int task_cpu, int sd_flag, int flags);
1009 	void (*migrate_task_rq)(struct task_struct *p, int next_cpu);
1010 
1011 	void (*pre_schedule) (struct rq *this_rq, struct task_struct *task);
1012 	void (*post_schedule) (struct rq *this_rq);
1013 	void (*task_waking) (struct task_struct *task);
1014 	void (*task_woken) (struct rq *this_rq, struct task_struct *task);
1015 
1016 	void (*set_cpus_allowed)(struct task_struct *p,
1017 				 const struct cpumask *newmask);
1018 
1019 	void (*rq_online)(struct rq *rq);
1020 	void (*rq_offline)(struct rq *rq);
1021 #endif
1022 
1023 	void (*set_curr_task) (struct rq *rq);
1024 	void (*task_tick) (struct rq *rq, struct task_struct *p, int queued);
1025 	void (*task_fork) (struct task_struct *p);
1026 
1027 	void (*switched_from) (struct rq *this_rq, struct task_struct *task);
1028 	void (*switched_to) (struct rq *this_rq, struct task_struct *task);
1029 	void (*prio_changed) (struct rq *this_rq, struct task_struct *task,
1030 			     int oldprio);
1031 
1032 	unsigned int (*get_rr_interval) (struct rq *rq,
1033 					 struct task_struct *task);
1034 
1035 #ifdef CONFIG_FAIR_GROUP_SCHED
1036 	void (*task_move_group) (struct task_struct *p, int on_rq);
1037 #endif
1038 };
1039 
1040 #define sched_class_highest (&stop_sched_class)
1041 #define for_each_class(class) \
1042    for (class = sched_class_highest; class; class = class->next)
1043 
1044 extern const struct sched_class stop_sched_class;
1045 extern const struct sched_class rt_sched_class;
1046 extern const struct sched_class fair_sched_class;
1047 extern const struct sched_class idle_sched_class;
1048 
1049 
1050 #ifdef CONFIG_SMP
1051 
1052 extern void update_group_power(struct sched_domain *sd, int cpu);
1053 
1054 extern void trigger_load_balance(struct rq *rq, int cpu);
1055 extern void idle_balance(int this_cpu, struct rq *this_rq);
1056 
1057 extern void idle_enter_fair(struct rq *this_rq);
1058 extern void idle_exit_fair(struct rq *this_rq);
1059 
1060 #else	/* CONFIG_SMP */
1061 
1062 static inline void idle_balance(int cpu, struct rq *rq)
1063 {
1064 }
1065 
1066 #endif
1067 
1068 extern void sysrq_sched_debug_show(void);
1069 extern void sched_init_granularity(void);
1070 extern void update_max_interval(void);
1071 extern void init_sched_rt_class(void);
1072 extern void init_sched_fair_class(void);
1073 
1074 extern void resched_task(struct task_struct *p);
1075 extern void resched_cpu(int cpu);
1076 
1077 extern struct rt_bandwidth def_rt_bandwidth;
1078 extern void init_rt_bandwidth(struct rt_bandwidth *rt_b, u64 period, u64 runtime);
1079 
1080 extern void update_idle_cpu_load(struct rq *this_rq);
1081 
1082 extern void init_task_runnable_average(struct task_struct *p);
1083 
1084 #ifdef CONFIG_PARAVIRT
1085 static inline u64 steal_ticks(u64 steal)
1086 {
1087 	if (unlikely(steal > NSEC_PER_SEC))
1088 		return div_u64(steal, TICK_NSEC);
1089 
1090 	return __iter_div_u64_rem(steal, TICK_NSEC, &steal);
1091 }
1092 #endif
1093 
1094 static inline void inc_nr_running(struct rq *rq)
1095 {
1096 	rq->nr_running++;
1097 
1098 #ifdef CONFIG_NO_HZ_FULL
1099 	if (rq->nr_running == 2) {
1100 		if (tick_nohz_full_cpu(rq->cpu)) {
1101 			/* Order rq->nr_running write against the IPI */
1102 			smp_wmb();
1103 			smp_send_reschedule(rq->cpu);
1104 		}
1105        }
1106 #endif
1107 }
1108 
1109 static inline void dec_nr_running(struct rq *rq)
1110 {
1111 	rq->nr_running--;
1112 }
1113 
1114 static inline void rq_last_tick_reset(struct rq *rq)
1115 {
1116 #ifdef CONFIG_NO_HZ_FULL
1117 	rq->last_sched_tick = jiffies;
1118 #endif
1119 }
1120 
1121 extern void update_rq_clock(struct rq *rq);
1122 
1123 extern void activate_task(struct rq *rq, struct task_struct *p, int flags);
1124 extern void deactivate_task(struct rq *rq, struct task_struct *p, int flags);
1125 
1126 extern void check_preempt_curr(struct rq *rq, struct task_struct *p, int flags);
1127 
1128 extern const_debug unsigned int sysctl_sched_time_avg;
1129 extern const_debug unsigned int sysctl_sched_nr_migrate;
1130 extern const_debug unsigned int sysctl_sched_migration_cost;
1131 
1132 static inline u64 sched_avg_period(void)
1133 {
1134 	return (u64)sysctl_sched_time_avg * NSEC_PER_MSEC / 2;
1135 }
1136 
1137 #ifdef CONFIG_SCHED_HRTICK
1138 
1139 /*
1140  * Use hrtick when:
1141  *  - enabled by features
1142  *  - hrtimer is actually high res
1143  */
1144 static inline int hrtick_enabled(struct rq *rq)
1145 {
1146 	if (!sched_feat(HRTICK))
1147 		return 0;
1148 	if (!cpu_active(cpu_of(rq)))
1149 		return 0;
1150 	return hrtimer_is_hres_active(&rq->hrtick_timer);
1151 }
1152 
1153 void hrtick_start(struct rq *rq, u64 delay);
1154 
1155 #else
1156 
1157 static inline int hrtick_enabled(struct rq *rq)
1158 {
1159 	return 0;
1160 }
1161 
1162 #endif /* CONFIG_SCHED_HRTICK */
1163 
1164 #ifdef CONFIG_SMP
1165 extern void sched_avg_update(struct rq *rq);
1166 static inline void sched_rt_avg_update(struct rq *rq, u64 rt_delta)
1167 {
1168 	rq->rt_avg += rt_delta;
1169 	sched_avg_update(rq);
1170 }
1171 #else
1172 static inline void sched_rt_avg_update(struct rq *rq, u64 rt_delta) { }
1173 static inline void sched_avg_update(struct rq *rq) { }
1174 #endif
1175 
1176 extern void start_bandwidth_timer(struct hrtimer *period_timer, ktime_t period);
1177 
1178 #ifdef CONFIG_SMP
1179 #ifdef CONFIG_PREEMPT
1180 
1181 static inline void double_rq_lock(struct rq *rq1, struct rq *rq2);
1182 
1183 /*
1184  * fair double_lock_balance: Safely acquires both rq->locks in a fair
1185  * way at the expense of forcing extra atomic operations in all
1186  * invocations.  This assures that the double_lock is acquired using the
1187  * same underlying policy as the spinlock_t on this architecture, which
1188  * reduces latency compared to the unfair variant below.  However, it
1189  * also adds more overhead and therefore may reduce throughput.
1190  */
1191 static inline int _double_lock_balance(struct rq *this_rq, struct rq *busiest)
1192 	__releases(this_rq->lock)
1193 	__acquires(busiest->lock)
1194 	__acquires(this_rq->lock)
1195 {
1196 	raw_spin_unlock(&this_rq->lock);
1197 	double_rq_lock(this_rq, busiest);
1198 
1199 	return 1;
1200 }
1201 
1202 #else
1203 /*
1204  * Unfair double_lock_balance: Optimizes throughput at the expense of
1205  * latency by eliminating extra atomic operations when the locks are
1206  * already in proper order on entry.  This favors lower cpu-ids and will
1207  * grant the double lock to lower cpus over higher ids under contention,
1208  * regardless of entry order into the function.
1209  */
1210 static inline int _double_lock_balance(struct rq *this_rq, struct rq *busiest)
1211 	__releases(this_rq->lock)
1212 	__acquires(busiest->lock)
1213 	__acquires(this_rq->lock)
1214 {
1215 	int ret = 0;
1216 
1217 	if (unlikely(!raw_spin_trylock(&busiest->lock))) {
1218 		if (busiest < this_rq) {
1219 			raw_spin_unlock(&this_rq->lock);
1220 			raw_spin_lock(&busiest->lock);
1221 			raw_spin_lock_nested(&this_rq->lock,
1222 					      SINGLE_DEPTH_NESTING);
1223 			ret = 1;
1224 		} else
1225 			raw_spin_lock_nested(&busiest->lock,
1226 					      SINGLE_DEPTH_NESTING);
1227 	}
1228 	return ret;
1229 }
1230 
1231 #endif /* CONFIG_PREEMPT */
1232 
1233 /*
1234  * double_lock_balance - lock the busiest runqueue, this_rq is locked already.
1235  */
1236 static inline int double_lock_balance(struct rq *this_rq, struct rq *busiest)
1237 {
1238 	if (unlikely(!irqs_disabled())) {
1239 		/* printk() doesn't work good under rq->lock */
1240 		raw_spin_unlock(&this_rq->lock);
1241 		BUG_ON(1);
1242 	}
1243 
1244 	return _double_lock_balance(this_rq, busiest);
1245 }
1246 
1247 static inline void double_unlock_balance(struct rq *this_rq, struct rq *busiest)
1248 	__releases(busiest->lock)
1249 {
1250 	raw_spin_unlock(&busiest->lock);
1251 	lock_set_subclass(&this_rq->lock.dep_map, 0, _RET_IP_);
1252 }
1253 
1254 static inline void double_lock(spinlock_t *l1, spinlock_t *l2)
1255 {
1256 	if (l1 > l2)
1257 		swap(l1, l2);
1258 
1259 	spin_lock(l1);
1260 	spin_lock_nested(l2, SINGLE_DEPTH_NESTING);
1261 }
1262 
1263 static inline void double_raw_lock(raw_spinlock_t *l1, raw_spinlock_t *l2)
1264 {
1265 	if (l1 > l2)
1266 		swap(l1, l2);
1267 
1268 	raw_spin_lock(l1);
1269 	raw_spin_lock_nested(l2, SINGLE_DEPTH_NESTING);
1270 }
1271 
1272 /*
1273  * double_rq_lock - safely lock two runqueues
1274  *
1275  * Note this does not disable interrupts like task_rq_lock,
1276  * you need to do so manually before calling.
1277  */
1278 static inline void double_rq_lock(struct rq *rq1, struct rq *rq2)
1279 	__acquires(rq1->lock)
1280 	__acquires(rq2->lock)
1281 {
1282 	BUG_ON(!irqs_disabled());
1283 	if (rq1 == rq2) {
1284 		raw_spin_lock(&rq1->lock);
1285 		__acquire(rq2->lock);	/* Fake it out ;) */
1286 	} else {
1287 		if (rq1 < rq2) {
1288 			raw_spin_lock(&rq1->lock);
1289 			raw_spin_lock_nested(&rq2->lock, SINGLE_DEPTH_NESTING);
1290 		} else {
1291 			raw_spin_lock(&rq2->lock);
1292 			raw_spin_lock_nested(&rq1->lock, SINGLE_DEPTH_NESTING);
1293 		}
1294 	}
1295 }
1296 
1297 /*
1298  * double_rq_unlock - safely unlock two runqueues
1299  *
1300  * Note this does not restore interrupts like task_rq_unlock,
1301  * you need to do so manually after calling.
1302  */
1303 static inline void double_rq_unlock(struct rq *rq1, struct rq *rq2)
1304 	__releases(rq1->lock)
1305 	__releases(rq2->lock)
1306 {
1307 	raw_spin_unlock(&rq1->lock);
1308 	if (rq1 != rq2)
1309 		raw_spin_unlock(&rq2->lock);
1310 	else
1311 		__release(rq2->lock);
1312 }
1313 
1314 #else /* CONFIG_SMP */
1315 
1316 /*
1317  * double_rq_lock - safely lock two runqueues
1318  *
1319  * Note this does not disable interrupts like task_rq_lock,
1320  * you need to do so manually before calling.
1321  */
1322 static inline void double_rq_lock(struct rq *rq1, struct rq *rq2)
1323 	__acquires(rq1->lock)
1324 	__acquires(rq2->lock)
1325 {
1326 	BUG_ON(!irqs_disabled());
1327 	BUG_ON(rq1 != rq2);
1328 	raw_spin_lock(&rq1->lock);
1329 	__acquire(rq2->lock);	/* Fake it out ;) */
1330 }
1331 
1332 /*
1333  * double_rq_unlock - safely unlock two runqueues
1334  *
1335  * Note this does not restore interrupts like task_rq_unlock,
1336  * you need to do so manually after calling.
1337  */
1338 static inline void double_rq_unlock(struct rq *rq1, struct rq *rq2)
1339 	__releases(rq1->lock)
1340 	__releases(rq2->lock)
1341 {
1342 	BUG_ON(rq1 != rq2);
1343 	raw_spin_unlock(&rq1->lock);
1344 	__release(rq2->lock);
1345 }
1346 
1347 #endif
1348 
1349 extern struct sched_entity *__pick_first_entity(struct cfs_rq *cfs_rq);
1350 extern struct sched_entity *__pick_last_entity(struct cfs_rq *cfs_rq);
1351 extern void print_cfs_stats(struct seq_file *m, int cpu);
1352 extern void print_rt_stats(struct seq_file *m, int cpu);
1353 
1354 extern void init_cfs_rq(struct cfs_rq *cfs_rq);
1355 extern void init_rt_rq(struct rt_rq *rt_rq, struct rq *rq);
1356 
1357 extern void cfs_bandwidth_usage_inc(void);
1358 extern void cfs_bandwidth_usage_dec(void);
1359 
1360 #ifdef CONFIG_NO_HZ_COMMON
1361 enum rq_nohz_flag_bits {
1362 	NOHZ_TICK_STOPPED,
1363 	NOHZ_BALANCE_KICK,
1364 };
1365 
1366 #define nohz_flags(cpu)	(&cpu_rq(cpu)->nohz_flags)
1367 #endif
1368 
1369 #ifdef CONFIG_IRQ_TIME_ACCOUNTING
1370 
1371 DECLARE_PER_CPU(u64, cpu_hardirq_time);
1372 DECLARE_PER_CPU(u64, cpu_softirq_time);
1373 
1374 #ifndef CONFIG_64BIT
1375 DECLARE_PER_CPU(seqcount_t, irq_time_seq);
1376 
1377 static inline void irq_time_write_begin(void)
1378 {
1379 	__this_cpu_inc(irq_time_seq.sequence);
1380 	smp_wmb();
1381 }
1382 
1383 static inline void irq_time_write_end(void)
1384 {
1385 	smp_wmb();
1386 	__this_cpu_inc(irq_time_seq.sequence);
1387 }
1388 
1389 static inline u64 irq_time_read(int cpu)
1390 {
1391 	u64 irq_time;
1392 	unsigned seq;
1393 
1394 	do {
1395 		seq = read_seqcount_begin(&per_cpu(irq_time_seq, cpu));
1396 		irq_time = per_cpu(cpu_softirq_time, cpu) +
1397 			   per_cpu(cpu_hardirq_time, cpu);
1398 	} while (read_seqcount_retry(&per_cpu(irq_time_seq, cpu), seq));
1399 
1400 	return irq_time;
1401 }
1402 #else /* CONFIG_64BIT */
1403 static inline void irq_time_write_begin(void)
1404 {
1405 }
1406 
1407 static inline void irq_time_write_end(void)
1408 {
1409 }
1410 
1411 static inline u64 irq_time_read(int cpu)
1412 {
1413 	return per_cpu(cpu_softirq_time, cpu) + per_cpu(cpu_hardirq_time, cpu);
1414 }
1415 #endif /* CONFIG_64BIT */
1416 #endif /* CONFIG_IRQ_TIME_ACCOUNTING */
1417