Merge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6
[deliverable/linux.git] / 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/sched/deadline.h>
6 #include <linux/mutex.h>
7 #include <linux/spinlock.h>
8 #include <linux/stop_machine.h>
9 #include <linux/irq_work.h>
10 #include <linux/tick.h>
11 #include <linux/slab.h>
12
13 #include "cpupri.h"
14 #include "cpudeadline.h"
15 #include "cpuacct.h"
16
17 struct rq;
18 struct cpuidle_state;
19
20 /* task_struct::on_rq states: */
21 #define TASK_ON_RQ_QUEUED 1
22 #define TASK_ON_RQ_MIGRATING 2
23
24 extern __read_mostly int scheduler_running;
25
26 extern unsigned long calc_load_update;
27 extern atomic_long_t calc_load_tasks;
28
29 extern void calc_global_load_tick(struct rq *this_rq);
30 extern long calc_load_fold_active(struct rq *this_rq);
31
32 #ifdef CONFIG_SMP
33 extern void update_cpu_load_active(struct rq *this_rq);
34 #else
35 static inline void update_cpu_load_active(struct rq *this_rq) { }
36 #endif
37
38 /*
39 * Helpers for converting nanosecond timing to jiffy resolution
40 */
41 #define NS_TO_JIFFIES(TIME) ((unsigned long)(TIME) / (NSEC_PER_SEC / HZ))
42
43 /*
44 * Increase resolution of nice-level calculations for 64-bit architectures.
45 * The extra resolution improves shares distribution and load balancing of
46 * low-weight task groups (eg. nice +19 on an autogroup), deeper taskgroup
47 * hierarchies, especially on larger systems. This is not a user-visible change
48 * and does not change the user-interface for setting shares/weights.
49 *
50 * We increase resolution only if we have enough bits to allow this increased
51 * resolution (i.e. BITS_PER_LONG > 32). The costs for increasing resolution
52 * when BITS_PER_LONG <= 32 are pretty high and the returns do not justify the
53 * increased costs.
54 */
55 #if 0 /* BITS_PER_LONG > 32 -- currently broken: it increases power usage under light load */
56 # define SCHED_LOAD_RESOLUTION 10
57 # define scale_load(w) ((w) << SCHED_LOAD_RESOLUTION)
58 # define scale_load_down(w) ((w) >> SCHED_LOAD_RESOLUTION)
59 #else
60 # define SCHED_LOAD_RESOLUTION 0
61 # define scale_load(w) (w)
62 # define scale_load_down(w) (w)
63 #endif
64
65 #define SCHED_LOAD_SHIFT (10 + SCHED_LOAD_RESOLUTION)
66 #define SCHED_LOAD_SCALE (1L << SCHED_LOAD_SHIFT)
67
68 #define NICE_0_LOAD SCHED_LOAD_SCALE
69 #define NICE_0_SHIFT SCHED_LOAD_SHIFT
70
71 /*
72 * Single value that decides SCHED_DEADLINE internal math precision.
73 * 10 -> just above 1us
74 * 9 -> just above 0.5us
75 */
76 #define DL_SCALE (10)
77
78 /*
79 * These are the 'tuning knobs' of the scheduler:
80 */
81
82 /*
83 * single value that denotes runtime == period, ie unlimited time.
84 */
85 #define RUNTIME_INF ((u64)~0ULL)
86
87 static inline int idle_policy(int policy)
88 {
89 return policy == SCHED_IDLE;
90 }
91 static inline int fair_policy(int policy)
92 {
93 return policy == SCHED_NORMAL || policy == SCHED_BATCH;
94 }
95
96 static inline int rt_policy(int policy)
97 {
98 return policy == SCHED_FIFO || policy == SCHED_RR;
99 }
100
101 static inline int dl_policy(int policy)
102 {
103 return policy == SCHED_DEADLINE;
104 }
105 static inline bool valid_policy(int policy)
106 {
107 return idle_policy(policy) || fair_policy(policy) ||
108 rt_policy(policy) || dl_policy(policy);
109 }
110
111 static inline int task_has_rt_policy(struct task_struct *p)
112 {
113 return rt_policy(p->policy);
114 }
115
116 static inline int task_has_dl_policy(struct task_struct *p)
117 {
118 return dl_policy(p->policy);
119 }
120
121 /*
122 * Tells if entity @a should preempt entity @b.
123 */
124 static inline bool
125 dl_entity_preempt(struct sched_dl_entity *a, struct sched_dl_entity *b)
126 {
127 return dl_time_before(a->deadline, b->deadline);
128 }
129
130 /*
131 * This is the priority-queue data structure of the RT scheduling class:
132 */
133 struct rt_prio_array {
134 DECLARE_BITMAP(bitmap, MAX_RT_PRIO+1); /* include 1 bit for delimiter */
135 struct list_head queue[MAX_RT_PRIO];
136 };
137
138 struct rt_bandwidth {
139 /* nests inside the rq lock: */
140 raw_spinlock_t rt_runtime_lock;
141 ktime_t rt_period;
142 u64 rt_runtime;
143 struct hrtimer rt_period_timer;
144 unsigned int rt_period_active;
145 };
146
147 void __dl_clear_params(struct task_struct *p);
148
149 /*
150 * To keep the bandwidth of -deadline tasks and groups under control
151 * we need some place where:
152 * - store the maximum -deadline bandwidth of the system (the group);
153 * - cache the fraction of that bandwidth that is currently allocated.
154 *
155 * This is all done in the data structure below. It is similar to the
156 * one used for RT-throttling (rt_bandwidth), with the main difference
157 * that, since here we are only interested in admission control, we
158 * do not decrease any runtime while the group "executes", neither we
159 * need a timer to replenish it.
160 *
161 * With respect to SMP, the bandwidth is given on a per-CPU basis,
162 * meaning that:
163 * - dl_bw (< 100%) is the bandwidth of the system (group) on each CPU;
164 * - dl_total_bw array contains, in the i-eth element, the currently
165 * allocated bandwidth on the i-eth CPU.
166 * Moreover, groups consume bandwidth on each CPU, while tasks only
167 * consume bandwidth on the CPU they're running on.
168 * Finally, dl_total_bw_cpu is used to cache the index of dl_total_bw
169 * that will be shown the next time the proc or cgroup controls will
170 * be red. It on its turn can be changed by writing on its own
171 * control.
172 */
173 struct dl_bandwidth {
174 raw_spinlock_t dl_runtime_lock;
175 u64 dl_runtime;
176 u64 dl_period;
177 };
178
179 static inline int dl_bandwidth_enabled(void)
180 {
181 return sysctl_sched_rt_runtime >= 0;
182 }
183
184 extern struct dl_bw *dl_bw_of(int i);
185
186 struct dl_bw {
187 raw_spinlock_t lock;
188 u64 bw, total_bw;
189 };
190
191 static inline
192 void __dl_clear(struct dl_bw *dl_b, u64 tsk_bw)
193 {
194 dl_b->total_bw -= tsk_bw;
195 }
196
197 static inline
198 void __dl_add(struct dl_bw *dl_b, u64 tsk_bw)
199 {
200 dl_b->total_bw += tsk_bw;
201 }
202
203 static inline
204 bool __dl_overflow(struct dl_bw *dl_b, int cpus, u64 old_bw, u64 new_bw)
205 {
206 return dl_b->bw != -1 &&
207 dl_b->bw * cpus < dl_b->total_bw - old_bw + new_bw;
208 }
209
210 extern struct mutex sched_domains_mutex;
211
212 #ifdef CONFIG_CGROUP_SCHED
213
214 #include <linux/cgroup.h>
215
216 struct cfs_rq;
217 struct rt_rq;
218
219 extern struct list_head task_groups;
220
221 struct cfs_bandwidth {
222 #ifdef CONFIG_CFS_BANDWIDTH
223 raw_spinlock_t lock;
224 ktime_t period;
225 u64 quota, runtime;
226 s64 hierarchical_quota;
227 u64 runtime_expires;
228
229 int idle, period_active;
230 struct hrtimer period_timer, slack_timer;
231 struct list_head throttled_cfs_rq;
232
233 /* statistics */
234 int nr_periods, nr_throttled;
235 u64 throttled_time;
236 #endif
237 };
238
239 /* task group related information */
240 struct task_group {
241 struct cgroup_subsys_state css;
242
243 #ifdef CONFIG_FAIR_GROUP_SCHED
244 /* schedulable entities of this group on each cpu */
245 struct sched_entity **se;
246 /* runqueue "owned" by this group on each cpu */
247 struct cfs_rq **cfs_rq;
248 unsigned long shares;
249
250 #ifdef CONFIG_SMP
251 atomic_long_t load_avg;
252 #endif
253 #endif
254
255 #ifdef CONFIG_RT_GROUP_SCHED
256 struct sched_rt_entity **rt_se;
257 struct rt_rq **rt_rq;
258
259 struct rt_bandwidth rt_bandwidth;
260 #endif
261
262 struct rcu_head rcu;
263 struct list_head list;
264
265 struct task_group *parent;
266 struct list_head siblings;
267 struct list_head children;
268
269 #ifdef CONFIG_SCHED_AUTOGROUP
270 struct autogroup *autogroup;
271 #endif
272
273 struct cfs_bandwidth cfs_bandwidth;
274 };
275
276 #ifdef CONFIG_FAIR_GROUP_SCHED
277 #define ROOT_TASK_GROUP_LOAD NICE_0_LOAD
278
279 /*
280 * A weight of 0 or 1 can cause arithmetics problems.
281 * A weight of a cfs_rq is the sum of weights of which entities
282 * are queued on this cfs_rq, so a weight of a entity should not be
283 * too large, so as the shares value of a task group.
284 * (The default weight is 1024 - so there's no practical
285 * limitation from this.)
286 */
287 #define MIN_SHARES (1UL << 1)
288 #define MAX_SHARES (1UL << 18)
289 #endif
290
291 typedef int (*tg_visitor)(struct task_group *, void *);
292
293 extern int walk_tg_tree_from(struct task_group *from,
294 tg_visitor down, tg_visitor up, void *data);
295
296 /*
297 * Iterate the full tree, calling @down when first entering a node and @up when
298 * leaving it for the final time.
299 *
300 * Caller must hold rcu_lock or sufficient equivalent.
301 */
302 static inline int walk_tg_tree(tg_visitor down, tg_visitor up, void *data)
303 {
304 return walk_tg_tree_from(&root_task_group, down, up, data);
305 }
306
307 extern int tg_nop(struct task_group *tg, void *data);
308
309 extern void free_fair_sched_group(struct task_group *tg);
310 extern int alloc_fair_sched_group(struct task_group *tg, struct task_group *parent);
311 extern void unregister_fair_sched_group(struct task_group *tg, int cpu);
312 extern void init_tg_cfs_entry(struct task_group *tg, struct cfs_rq *cfs_rq,
313 struct sched_entity *se, int cpu,
314 struct sched_entity *parent);
315 extern void init_cfs_bandwidth(struct cfs_bandwidth *cfs_b);
316 extern int sched_group_set_shares(struct task_group *tg, unsigned long shares);
317
318 extern void __refill_cfs_bandwidth_runtime(struct cfs_bandwidth *cfs_b);
319 extern void start_cfs_bandwidth(struct cfs_bandwidth *cfs_b);
320 extern void unthrottle_cfs_rq(struct cfs_rq *cfs_rq);
321
322 extern void free_rt_sched_group(struct task_group *tg);
323 extern int alloc_rt_sched_group(struct task_group *tg, struct task_group *parent);
324 extern void init_tg_rt_entry(struct task_group *tg, struct rt_rq *rt_rq,
325 struct sched_rt_entity *rt_se, int cpu,
326 struct sched_rt_entity *parent);
327
328 extern struct task_group *sched_create_group(struct task_group *parent);
329 extern void sched_online_group(struct task_group *tg,
330 struct task_group *parent);
331 extern void sched_destroy_group(struct task_group *tg);
332 extern void sched_offline_group(struct task_group *tg);
333
334 extern void sched_move_task(struct task_struct *tsk);
335
336 #ifdef CONFIG_FAIR_GROUP_SCHED
337 extern int sched_group_set_shares(struct task_group *tg, unsigned long shares);
338 #endif
339
340 #else /* CONFIG_CGROUP_SCHED */
341
342 struct cfs_bandwidth { };
343
344 #endif /* CONFIG_CGROUP_SCHED */
345
346 /* CFS-related fields in a runqueue */
347 struct cfs_rq {
348 struct load_weight load;
349 unsigned int nr_running, h_nr_running;
350
351 u64 exec_clock;
352 u64 min_vruntime;
353 #ifndef CONFIG_64BIT
354 u64 min_vruntime_copy;
355 #endif
356
357 struct rb_root tasks_timeline;
358 struct rb_node *rb_leftmost;
359
360 /*
361 * 'curr' points to currently running entity on this cfs_rq.
362 * It is set to NULL otherwise (i.e when none are currently running).
363 */
364 struct sched_entity *curr, *next, *last, *skip;
365
366 #ifdef CONFIG_SCHED_DEBUG
367 unsigned int nr_spread_over;
368 #endif
369
370 #ifdef CONFIG_SMP
371 /*
372 * CFS load tracking
373 */
374 struct sched_avg avg;
375 u64 runnable_load_sum;
376 unsigned long runnable_load_avg;
377 #ifdef CONFIG_FAIR_GROUP_SCHED
378 unsigned long tg_load_avg_contrib;
379 #endif
380 atomic_long_t removed_load_avg, removed_util_avg;
381 #ifndef CONFIG_64BIT
382 u64 load_last_update_time_copy;
383 #endif
384
385 #ifdef CONFIG_FAIR_GROUP_SCHED
386 /*
387 * h_load = weight * f(tg)
388 *
389 * Where f(tg) is the recursive weight fraction assigned to
390 * this group.
391 */
392 unsigned long h_load;
393 u64 last_h_load_update;
394 struct sched_entity *h_load_next;
395 #endif /* CONFIG_FAIR_GROUP_SCHED */
396 #endif /* CONFIG_SMP */
397
398 #ifdef CONFIG_FAIR_GROUP_SCHED
399 struct rq *rq; /* cpu runqueue to which this cfs_rq is attached */
400
401 /*
402 * leaf cfs_rqs are those that hold tasks (lowest schedulable entity in
403 * a hierarchy). Non-leaf lrqs hold other higher schedulable entities
404 * (like users, containers etc.)
405 *
406 * leaf_cfs_rq_list ties together list of leaf cfs_rq's in a cpu. This
407 * list is used during load balance.
408 */
409 int on_list;
410 struct list_head leaf_cfs_rq_list;
411 struct task_group *tg; /* group that "owns" this runqueue */
412
413 #ifdef CONFIG_CFS_BANDWIDTH
414 int runtime_enabled;
415 u64 runtime_expires;
416 s64 runtime_remaining;
417
418 u64 throttled_clock, throttled_clock_task;
419 u64 throttled_clock_task_time;
420 int throttled, throttle_count;
421 struct list_head throttled_list;
422 #endif /* CONFIG_CFS_BANDWIDTH */
423 #endif /* CONFIG_FAIR_GROUP_SCHED */
424 };
425
426 static inline int rt_bandwidth_enabled(void)
427 {
428 return sysctl_sched_rt_runtime >= 0;
429 }
430
431 /* RT IPI pull logic requires IRQ_WORK */
432 #ifdef CONFIG_IRQ_WORK
433 # define HAVE_RT_PUSH_IPI
434 #endif
435
436 /* Real-Time classes' related field in a runqueue: */
437 struct rt_rq {
438 struct rt_prio_array active;
439 unsigned int rt_nr_running;
440 #if defined CONFIG_SMP || defined CONFIG_RT_GROUP_SCHED
441 struct {
442 int curr; /* highest queued rt task prio */
443 #ifdef CONFIG_SMP
444 int next; /* next highest */
445 #endif
446 } highest_prio;
447 #endif
448 #ifdef CONFIG_SMP
449 unsigned long rt_nr_migratory;
450 unsigned long rt_nr_total;
451 int overloaded;
452 struct plist_head pushable_tasks;
453 #ifdef HAVE_RT_PUSH_IPI
454 int push_flags;
455 int push_cpu;
456 struct irq_work push_work;
457 raw_spinlock_t push_lock;
458 #endif
459 #endif /* CONFIG_SMP */
460 int rt_queued;
461
462 int rt_throttled;
463 u64 rt_time;
464 u64 rt_runtime;
465 /* Nests inside the rq lock: */
466 raw_spinlock_t rt_runtime_lock;
467
468 #ifdef CONFIG_RT_GROUP_SCHED
469 unsigned long rt_nr_boosted;
470
471 struct rq *rq;
472 struct task_group *tg;
473 #endif
474 };
475
476 /* Deadline class' related fields in a runqueue */
477 struct dl_rq {
478 /* runqueue is an rbtree, ordered by deadline */
479 struct rb_root rb_root;
480 struct rb_node *rb_leftmost;
481
482 unsigned long dl_nr_running;
483
484 #ifdef CONFIG_SMP
485 /*
486 * Deadline values of the currently executing and the
487 * earliest ready task on this rq. Caching these facilitates
488 * the decision wether or not a ready but not running task
489 * should migrate somewhere else.
490 */
491 struct {
492 u64 curr;
493 u64 next;
494 } earliest_dl;
495
496 unsigned long dl_nr_migratory;
497 int overloaded;
498
499 /*
500 * Tasks on this rq that can be pushed away. They are kept in
501 * an rb-tree, ordered by tasks' deadlines, with caching
502 * of the leftmost (earliest deadline) element.
503 */
504 struct rb_root pushable_dl_tasks_root;
505 struct rb_node *pushable_dl_tasks_leftmost;
506 #else
507 struct dl_bw dl_bw;
508 #endif
509 };
510
511 #ifdef CONFIG_SMP
512
513 /*
514 * We add the notion of a root-domain which will be used to define per-domain
515 * variables. Each exclusive cpuset essentially defines an island domain by
516 * fully partitioning the member cpus from any other cpuset. Whenever a new
517 * exclusive cpuset is created, we also create and attach a new root-domain
518 * object.
519 *
520 */
521 struct root_domain {
522 atomic_t refcount;
523 atomic_t rto_count;
524 struct rcu_head rcu;
525 cpumask_var_t span;
526 cpumask_var_t online;
527
528 /* Indicate more than one runnable task for any CPU */
529 bool overload;
530
531 /*
532 * The bit corresponding to a CPU gets set here if such CPU has more
533 * than one runnable -deadline task (as it is below for RT tasks).
534 */
535 cpumask_var_t dlo_mask;
536 atomic_t dlo_count;
537 struct dl_bw dl_bw;
538 struct cpudl cpudl;
539
540 /*
541 * The "RT overload" flag: it gets set if a CPU has more than
542 * one runnable RT task.
543 */
544 cpumask_var_t rto_mask;
545 struct cpupri cpupri;
546 };
547
548 extern struct root_domain def_root_domain;
549
550 #endif /* CONFIG_SMP */
551
552 /*
553 * This is the main, per-CPU runqueue data structure.
554 *
555 * Locking rule: those places that want to lock multiple runqueues
556 * (such as the load balancing or the thread migration code), lock
557 * acquire operations must be ordered by ascending &runqueue.
558 */
559 struct rq {
560 /* runqueue lock: */
561 raw_spinlock_t lock;
562
563 /*
564 * nr_running and cpu_load should be in the same cacheline because
565 * remote CPUs use both these fields when doing load calculation.
566 */
567 unsigned int nr_running;
568 #ifdef CONFIG_NUMA_BALANCING
569 unsigned int nr_numa_running;
570 unsigned int nr_preferred_running;
571 #endif
572 #define CPU_LOAD_IDX_MAX 5
573 unsigned long cpu_load[CPU_LOAD_IDX_MAX];
574 unsigned long last_load_update_tick;
575 #ifdef CONFIG_NO_HZ_COMMON
576 u64 nohz_stamp;
577 unsigned long nohz_flags;
578 #endif
579 #ifdef CONFIG_NO_HZ_FULL
580 unsigned long last_sched_tick;
581 #endif
582 /* capture load from *all* tasks on this cpu: */
583 struct load_weight load;
584 unsigned long nr_load_updates;
585 u64 nr_switches;
586
587 struct cfs_rq cfs;
588 struct rt_rq rt;
589 struct dl_rq dl;
590
591 #ifdef CONFIG_FAIR_GROUP_SCHED
592 /* list of leaf cfs_rq on this cpu: */
593 struct list_head leaf_cfs_rq_list;
594 #endif /* CONFIG_FAIR_GROUP_SCHED */
595
596 /*
597 * This is part of a global counter where only the total sum
598 * over all CPUs matters. A task can increase this counter on
599 * one CPU and if it got migrated afterwards it may decrease
600 * it on another CPU. Always updated under the runqueue lock:
601 */
602 unsigned long nr_uninterruptible;
603
604 struct task_struct *curr, *idle, *stop;
605 unsigned long next_balance;
606 struct mm_struct *prev_mm;
607
608 unsigned int clock_skip_update;
609 u64 clock;
610 u64 clock_task;
611
612 atomic_t nr_iowait;
613
614 #ifdef CONFIG_SMP
615 struct root_domain *rd;
616 struct sched_domain *sd;
617
618 unsigned long cpu_capacity;
619 unsigned long cpu_capacity_orig;
620
621 struct callback_head *balance_callback;
622
623 unsigned char idle_balance;
624 /* For active balancing */
625 int active_balance;
626 int push_cpu;
627 struct cpu_stop_work active_balance_work;
628 /* cpu of this runqueue: */
629 int cpu;
630 int online;
631
632 struct list_head cfs_tasks;
633
634 u64 rt_avg;
635 u64 age_stamp;
636 u64 idle_stamp;
637 u64 avg_idle;
638
639 /* This is used to determine avg_idle's max value */
640 u64 max_idle_balance_cost;
641 #endif
642
643 #ifdef CONFIG_IRQ_TIME_ACCOUNTING
644 u64 prev_irq_time;
645 #endif
646 #ifdef CONFIG_PARAVIRT
647 u64 prev_steal_time;
648 #endif
649 #ifdef CONFIG_PARAVIRT_TIME_ACCOUNTING
650 u64 prev_steal_time_rq;
651 #endif
652
653 /* calc_load related fields */
654 unsigned long calc_load_update;
655 long calc_load_active;
656
657 #ifdef CONFIG_SCHED_HRTICK
658 #ifdef CONFIG_SMP
659 int hrtick_csd_pending;
660 struct call_single_data hrtick_csd;
661 #endif
662 struct hrtimer hrtick_timer;
663 #endif
664
665 #ifdef CONFIG_SCHEDSTATS
666 /* latency stats */
667 struct sched_info rq_sched_info;
668 unsigned long long rq_cpu_time;
669 /* could above be rq->cfs_rq.exec_clock + rq->rt_rq.rt_runtime ? */
670
671 /* sys_sched_yield() stats */
672 unsigned int yld_count;
673
674 /* schedule() stats */
675 unsigned int sched_count;
676 unsigned int sched_goidle;
677
678 /* try_to_wake_up() stats */
679 unsigned int ttwu_count;
680 unsigned int ttwu_local;
681 #endif
682
683 #ifdef CONFIG_SMP
684 struct llist_head wake_list;
685 #endif
686
687 #ifdef CONFIG_CPU_IDLE
688 /* Must be inspected within a rcu lock section */
689 struct cpuidle_state *idle_state;
690 #endif
691 };
692
693 static inline int cpu_of(struct rq *rq)
694 {
695 #ifdef CONFIG_SMP
696 return rq->cpu;
697 #else
698 return 0;
699 #endif
700 }
701
702 DECLARE_PER_CPU_SHARED_ALIGNED(struct rq, runqueues);
703
704 #define cpu_rq(cpu) (&per_cpu(runqueues, (cpu)))
705 #define this_rq() this_cpu_ptr(&runqueues)
706 #define task_rq(p) cpu_rq(task_cpu(p))
707 #define cpu_curr(cpu) (cpu_rq(cpu)->curr)
708 #define raw_rq() raw_cpu_ptr(&runqueues)
709
710 static inline u64 __rq_clock_broken(struct rq *rq)
711 {
712 return READ_ONCE(rq->clock);
713 }
714
715 static inline u64 rq_clock(struct rq *rq)
716 {
717 lockdep_assert_held(&rq->lock);
718 return rq->clock;
719 }
720
721 static inline u64 rq_clock_task(struct rq *rq)
722 {
723 lockdep_assert_held(&rq->lock);
724 return rq->clock_task;
725 }
726
727 #define RQCF_REQ_SKIP 0x01
728 #define RQCF_ACT_SKIP 0x02
729
730 static inline void rq_clock_skip_update(struct rq *rq, bool skip)
731 {
732 lockdep_assert_held(&rq->lock);
733 if (skip)
734 rq->clock_skip_update |= RQCF_REQ_SKIP;
735 else
736 rq->clock_skip_update &= ~RQCF_REQ_SKIP;
737 }
738
739 #ifdef CONFIG_NUMA
740 enum numa_topology_type {
741 NUMA_DIRECT,
742 NUMA_GLUELESS_MESH,
743 NUMA_BACKPLANE,
744 };
745 extern enum numa_topology_type sched_numa_topology_type;
746 extern int sched_max_numa_distance;
747 extern bool find_numa_distance(int distance);
748 #endif
749
750 #ifdef CONFIG_NUMA_BALANCING
751 /* The regions in numa_faults array from task_struct */
752 enum numa_faults_stats {
753 NUMA_MEM = 0,
754 NUMA_CPU,
755 NUMA_MEMBUF,
756 NUMA_CPUBUF
757 };
758 extern void sched_setnuma(struct task_struct *p, int node);
759 extern int migrate_task_to(struct task_struct *p, int cpu);
760 extern int migrate_swap(struct task_struct *, struct task_struct *);
761 #endif /* CONFIG_NUMA_BALANCING */
762
763 #ifdef CONFIG_SMP
764
765 static inline void
766 queue_balance_callback(struct rq *rq,
767 struct callback_head *head,
768 void (*func)(struct rq *rq))
769 {
770 lockdep_assert_held(&rq->lock);
771
772 if (unlikely(head->next))
773 return;
774
775 head->func = (void (*)(struct callback_head *))func;
776 head->next = rq->balance_callback;
777 rq->balance_callback = head;
778 }
779
780 extern void sched_ttwu_pending(void);
781
782 #define rcu_dereference_check_sched_domain(p) \
783 rcu_dereference_check((p), \
784 lockdep_is_held(&sched_domains_mutex))
785
786 /*
787 * The domain tree (rq->sd) is protected by RCU's quiescent state transition.
788 * See detach_destroy_domains: synchronize_sched for details.
789 *
790 * The domain tree of any CPU may only be accessed from within
791 * preempt-disabled sections.
792 */
793 #define for_each_domain(cpu, __sd) \
794 for (__sd = rcu_dereference_check_sched_domain(cpu_rq(cpu)->sd); \
795 __sd; __sd = __sd->parent)
796
797 #define for_each_lower_domain(sd) for (; sd; sd = sd->child)
798
799 /**
800 * highest_flag_domain - Return highest sched_domain containing flag.
801 * @cpu: The cpu whose highest level of sched domain is to
802 * be returned.
803 * @flag: The flag to check for the highest sched_domain
804 * for the given cpu.
805 *
806 * Returns the highest sched_domain of a cpu which contains the given flag.
807 */
808 static inline struct sched_domain *highest_flag_domain(int cpu, int flag)
809 {
810 struct sched_domain *sd, *hsd = NULL;
811
812 for_each_domain(cpu, sd) {
813 if (!(sd->flags & flag))
814 break;
815 hsd = sd;
816 }
817
818 return hsd;
819 }
820
821 static inline struct sched_domain *lowest_flag_domain(int cpu, int flag)
822 {
823 struct sched_domain *sd;
824
825 for_each_domain(cpu, sd) {
826 if (sd->flags & flag)
827 break;
828 }
829
830 return sd;
831 }
832
833 DECLARE_PER_CPU(struct sched_domain *, sd_llc);
834 DECLARE_PER_CPU(int, sd_llc_size);
835 DECLARE_PER_CPU(int, sd_llc_id);
836 DECLARE_PER_CPU(struct sched_domain *, sd_numa);
837 DECLARE_PER_CPU(struct sched_domain *, sd_busy);
838 DECLARE_PER_CPU(struct sched_domain *, sd_asym);
839
840 struct sched_group_capacity {
841 atomic_t ref;
842 /*
843 * CPU capacity of this group, SCHED_LOAD_SCALE being max capacity
844 * for a single CPU.
845 */
846 unsigned int capacity;
847 unsigned long next_update;
848 int imbalance; /* XXX unrelated to capacity but shared group state */
849 /*
850 * Number of busy cpus in this group.
851 */
852 atomic_t nr_busy_cpus;
853
854 unsigned long cpumask[0]; /* iteration mask */
855 };
856
857 struct sched_group {
858 struct sched_group *next; /* Must be a circular list */
859 atomic_t ref;
860
861 unsigned int group_weight;
862 struct sched_group_capacity *sgc;
863
864 /*
865 * The CPUs this group covers.
866 *
867 * NOTE: this field is variable length. (Allocated dynamically
868 * by attaching extra space to the end of the structure,
869 * depending on how many CPUs the kernel has booted up with)
870 */
871 unsigned long cpumask[0];
872 };
873
874 static inline struct cpumask *sched_group_cpus(struct sched_group *sg)
875 {
876 return to_cpumask(sg->cpumask);
877 }
878
879 /*
880 * cpumask masking which cpus in the group are allowed to iterate up the domain
881 * tree.
882 */
883 static inline struct cpumask *sched_group_mask(struct sched_group *sg)
884 {
885 return to_cpumask(sg->sgc->cpumask);
886 }
887
888 /**
889 * group_first_cpu - Returns the first cpu in the cpumask of a sched_group.
890 * @group: The group whose first cpu is to be returned.
891 */
892 static inline unsigned int group_first_cpu(struct sched_group *group)
893 {
894 return cpumask_first(sched_group_cpus(group));
895 }
896
897 extern int group_balance_cpu(struct sched_group *sg);
898
899 #else
900
901 static inline void sched_ttwu_pending(void) { }
902
903 #endif /* CONFIG_SMP */
904
905 #include "stats.h"
906 #include "auto_group.h"
907
908 #ifdef CONFIG_CGROUP_SCHED
909
910 /*
911 * Return the group to which this tasks belongs.
912 *
913 * We cannot use task_css() and friends because the cgroup subsystem
914 * changes that value before the cgroup_subsys::attach() method is called,
915 * therefore we cannot pin it and might observe the wrong value.
916 *
917 * The same is true for autogroup's p->signal->autogroup->tg, the autogroup
918 * core changes this before calling sched_move_task().
919 *
920 * Instead we use a 'copy' which is updated from sched_move_task() while
921 * holding both task_struct::pi_lock and rq::lock.
922 */
923 static inline struct task_group *task_group(struct task_struct *p)
924 {
925 return p->sched_task_group;
926 }
927
928 /* Change a task's cfs_rq and parent entity if it moves across CPUs/groups */
929 static inline void set_task_rq(struct task_struct *p, unsigned int cpu)
930 {
931 #if defined(CONFIG_FAIR_GROUP_SCHED) || defined(CONFIG_RT_GROUP_SCHED)
932 struct task_group *tg = task_group(p);
933 #endif
934
935 #ifdef CONFIG_FAIR_GROUP_SCHED
936 p->se.cfs_rq = tg->cfs_rq[cpu];
937 p->se.parent = tg->se[cpu];
938 #endif
939
940 #ifdef CONFIG_RT_GROUP_SCHED
941 p->rt.rt_rq = tg->rt_rq[cpu];
942 p->rt.parent = tg->rt_se[cpu];
943 #endif
944 }
945
946 #else /* CONFIG_CGROUP_SCHED */
947
948 static inline void set_task_rq(struct task_struct *p, unsigned int cpu) { }
949 static inline struct task_group *task_group(struct task_struct *p)
950 {
951 return NULL;
952 }
953
954 #endif /* CONFIG_CGROUP_SCHED */
955
956 static inline void __set_task_cpu(struct task_struct *p, unsigned int cpu)
957 {
958 set_task_rq(p, cpu);
959 #ifdef CONFIG_SMP
960 /*
961 * After ->cpu is set up to a new value, task_rq_lock(p, ...) can be
962 * successfuly executed on another CPU. We must ensure that updates of
963 * per-task data have been completed by this moment.
964 */
965 smp_wmb();
966 task_thread_info(p)->cpu = cpu;
967 p->wake_cpu = cpu;
968 #endif
969 }
970
971 /*
972 * Tunables that become constants when CONFIG_SCHED_DEBUG is off:
973 */
974 #ifdef CONFIG_SCHED_DEBUG
975 # include <linux/static_key.h>
976 # define const_debug __read_mostly
977 #else
978 # define const_debug const
979 #endif
980
981 extern const_debug unsigned int sysctl_sched_features;
982
983 #define SCHED_FEAT(name, enabled) \
984 __SCHED_FEAT_##name ,
985
986 enum {
987 #include "features.h"
988 __SCHED_FEAT_NR,
989 };
990
991 #undef SCHED_FEAT
992
993 #if defined(CONFIG_SCHED_DEBUG) && defined(HAVE_JUMP_LABEL)
994 #define SCHED_FEAT(name, enabled) \
995 static __always_inline bool static_branch_##name(struct static_key *key) \
996 { \
997 return static_key_##enabled(key); \
998 }
999
1000 #include "features.h"
1001
1002 #undef SCHED_FEAT
1003
1004 extern struct static_key sched_feat_keys[__SCHED_FEAT_NR];
1005 #define sched_feat(x) (static_branch_##x(&sched_feat_keys[__SCHED_FEAT_##x]))
1006 #else /* !(SCHED_DEBUG && HAVE_JUMP_LABEL) */
1007 #define sched_feat(x) (sysctl_sched_features & (1UL << __SCHED_FEAT_##x))
1008 #endif /* SCHED_DEBUG && HAVE_JUMP_LABEL */
1009
1010 extern struct static_key_false sched_numa_balancing;
1011
1012 static inline u64 global_rt_period(void)
1013 {
1014 return (u64)sysctl_sched_rt_period * NSEC_PER_USEC;
1015 }
1016
1017 static inline u64 global_rt_runtime(void)
1018 {
1019 if (sysctl_sched_rt_runtime < 0)
1020 return RUNTIME_INF;
1021
1022 return (u64)sysctl_sched_rt_runtime * NSEC_PER_USEC;
1023 }
1024
1025 static inline int task_current(struct rq *rq, struct task_struct *p)
1026 {
1027 return rq->curr == p;
1028 }
1029
1030 static inline int task_running(struct rq *rq, struct task_struct *p)
1031 {
1032 #ifdef CONFIG_SMP
1033 return p->on_cpu;
1034 #else
1035 return task_current(rq, p);
1036 #endif
1037 }
1038
1039 static inline int task_on_rq_queued(struct task_struct *p)
1040 {
1041 return p->on_rq == TASK_ON_RQ_QUEUED;
1042 }
1043
1044 static inline int task_on_rq_migrating(struct task_struct *p)
1045 {
1046 return p->on_rq == TASK_ON_RQ_MIGRATING;
1047 }
1048
1049 #ifndef prepare_arch_switch
1050 # define prepare_arch_switch(next) do { } while (0)
1051 #endif
1052 #ifndef finish_arch_post_lock_switch
1053 # define finish_arch_post_lock_switch() do { } while (0)
1054 #endif
1055
1056 static inline void prepare_lock_switch(struct rq *rq, struct task_struct *next)
1057 {
1058 #ifdef CONFIG_SMP
1059 /*
1060 * We can optimise this out completely for !SMP, because the
1061 * SMP rebalancing from interrupt is the only thing that cares
1062 * here.
1063 */
1064 next->on_cpu = 1;
1065 #endif
1066 }
1067
1068 static inline void finish_lock_switch(struct rq *rq, struct task_struct *prev)
1069 {
1070 #ifdef CONFIG_SMP
1071 /*
1072 * After ->on_cpu is cleared, the task can be moved to a different CPU.
1073 * We must ensure this doesn't happen until the switch is completely
1074 * finished.
1075 *
1076 * Pairs with the control dependency and rmb in try_to_wake_up().
1077 */
1078 smp_store_release(&prev->on_cpu, 0);
1079 #endif
1080 #ifdef CONFIG_DEBUG_SPINLOCK
1081 /* this is a valid case when another task releases the spinlock */
1082 rq->lock.owner = current;
1083 #endif
1084 /*
1085 * If we are tracking spinlock dependencies then we have to
1086 * fix up the runqueue lock - which gets 'carried over' from
1087 * prev into current:
1088 */
1089 spin_acquire(&rq->lock.dep_map, 0, 0, _THIS_IP_);
1090
1091 raw_spin_unlock_irq(&rq->lock);
1092 }
1093
1094 /*
1095 * wake flags
1096 */
1097 #define WF_SYNC 0x01 /* waker goes to sleep after wakeup */
1098 #define WF_FORK 0x02 /* child wakeup after fork */
1099 #define WF_MIGRATED 0x4 /* internal use, task got migrated */
1100
1101 /*
1102 * To aid in avoiding the subversion of "niceness" due to uneven distribution
1103 * of tasks with abnormal "nice" values across CPUs the contribution that
1104 * each task makes to its run queue's load is weighted according to its
1105 * scheduling class and "nice" value. For SCHED_NORMAL tasks this is just a
1106 * scaled version of the new time slice allocation that they receive on time
1107 * slice expiry etc.
1108 */
1109
1110 #define WEIGHT_IDLEPRIO 3
1111 #define WMULT_IDLEPRIO 1431655765
1112
1113 /*
1114 * Nice levels are multiplicative, with a gentle 10% change for every
1115 * nice level changed. I.e. when a CPU-bound task goes from nice 0 to
1116 * nice 1, it will get ~10% less CPU time than another CPU-bound task
1117 * that remained on nice 0.
1118 *
1119 * The "10% effect" is relative and cumulative: from _any_ nice level,
1120 * if you go up 1 level, it's -10% CPU usage, if you go down 1 level
1121 * it's +10% CPU usage. (to achieve that we use a multiplier of 1.25.
1122 * If a task goes up by ~10% and another task goes down by ~10% then
1123 * the relative distance between them is ~25%.)
1124 */
1125 static const int prio_to_weight[40] = {
1126 /* -20 */ 88761, 71755, 56483, 46273, 36291,
1127 /* -15 */ 29154, 23254, 18705, 14949, 11916,
1128 /* -10 */ 9548, 7620, 6100, 4904, 3906,
1129 /* -5 */ 3121, 2501, 1991, 1586, 1277,
1130 /* 0 */ 1024, 820, 655, 526, 423,
1131 /* 5 */ 335, 272, 215, 172, 137,
1132 /* 10 */ 110, 87, 70, 56, 45,
1133 /* 15 */ 36, 29, 23, 18, 15,
1134 };
1135
1136 /*
1137 * Inverse (2^32/x) values of the prio_to_weight[] array, precalculated.
1138 *
1139 * In cases where the weight does not change often, we can use the
1140 * precalculated inverse to speed up arithmetics by turning divisions
1141 * into multiplications:
1142 */
1143 static const u32 prio_to_wmult[40] = {
1144 /* -20 */ 48388, 59856, 76040, 92818, 118348,
1145 /* -15 */ 147320, 184698, 229616, 287308, 360437,
1146 /* -10 */ 449829, 563644, 704093, 875809, 1099582,
1147 /* -5 */ 1376151, 1717300, 2157191, 2708050, 3363326,
1148 /* 0 */ 4194304, 5237765, 6557202, 8165337, 10153587,
1149 /* 5 */ 12820798, 15790321, 19976592, 24970740, 31350126,
1150 /* 10 */ 39045157, 49367440, 61356676, 76695844, 95443717,
1151 /* 15 */ 119304647, 148102320, 186737708, 238609294, 286331153,
1152 };
1153
1154 #define ENQUEUE_WAKEUP 0x01
1155 #define ENQUEUE_HEAD 0x02
1156 #ifdef CONFIG_SMP
1157 #define ENQUEUE_WAKING 0x04 /* sched_class::task_waking was called */
1158 #else
1159 #define ENQUEUE_WAKING 0x00
1160 #endif
1161 #define ENQUEUE_REPLENISH 0x08
1162 #define ENQUEUE_RESTORE 0x10
1163
1164 #define DEQUEUE_SLEEP 0x01
1165 #define DEQUEUE_SAVE 0x02
1166
1167 #define RETRY_TASK ((void *)-1UL)
1168
1169 struct sched_class {
1170 const struct sched_class *next;
1171
1172 void (*enqueue_task) (struct rq *rq, struct task_struct *p, int flags);
1173 void (*dequeue_task) (struct rq *rq, struct task_struct *p, int flags);
1174 void (*yield_task) (struct rq *rq);
1175 bool (*yield_to_task) (struct rq *rq, struct task_struct *p, bool preempt);
1176
1177 void (*check_preempt_curr) (struct rq *rq, struct task_struct *p, int flags);
1178
1179 /*
1180 * It is the responsibility of the pick_next_task() method that will
1181 * return the next task to call put_prev_task() on the @prev task or
1182 * something equivalent.
1183 *
1184 * May return RETRY_TASK when it finds a higher prio class has runnable
1185 * tasks.
1186 */
1187 struct task_struct * (*pick_next_task) (struct rq *rq,
1188 struct task_struct *prev);
1189 void (*put_prev_task) (struct rq *rq, struct task_struct *p);
1190
1191 #ifdef CONFIG_SMP
1192 int (*select_task_rq)(struct task_struct *p, int task_cpu, int sd_flag, int flags);
1193 void (*migrate_task_rq)(struct task_struct *p);
1194
1195 void (*task_waking) (struct task_struct *task);
1196 void (*task_woken) (struct rq *this_rq, struct task_struct *task);
1197
1198 void (*set_cpus_allowed)(struct task_struct *p,
1199 const struct cpumask *newmask);
1200
1201 void (*rq_online)(struct rq *rq);
1202 void (*rq_offline)(struct rq *rq);
1203 #endif
1204
1205 void (*set_curr_task) (struct rq *rq);
1206 void (*task_tick) (struct rq *rq, struct task_struct *p, int queued);
1207 void (*task_fork) (struct task_struct *p);
1208 void (*task_dead) (struct task_struct *p);
1209
1210 /*
1211 * The switched_from() call is allowed to drop rq->lock, therefore we
1212 * cannot assume the switched_from/switched_to pair is serliazed by
1213 * rq->lock. They are however serialized by p->pi_lock.
1214 */
1215 void (*switched_from) (struct rq *this_rq, struct task_struct *task);
1216 void (*switched_to) (struct rq *this_rq, struct task_struct *task);
1217 void (*prio_changed) (struct rq *this_rq, struct task_struct *task,
1218 int oldprio);
1219
1220 unsigned int (*get_rr_interval) (struct rq *rq,
1221 struct task_struct *task);
1222
1223 void (*update_curr) (struct rq *rq);
1224
1225 #ifdef CONFIG_FAIR_GROUP_SCHED
1226 void (*task_move_group) (struct task_struct *p);
1227 #endif
1228 };
1229
1230 static inline void put_prev_task(struct rq *rq, struct task_struct *prev)
1231 {
1232 prev->sched_class->put_prev_task(rq, prev);
1233 }
1234
1235 #define sched_class_highest (&stop_sched_class)
1236 #define for_each_class(class) \
1237 for (class = sched_class_highest; class; class = class->next)
1238
1239 extern const struct sched_class stop_sched_class;
1240 extern const struct sched_class dl_sched_class;
1241 extern const struct sched_class rt_sched_class;
1242 extern const struct sched_class fair_sched_class;
1243 extern const struct sched_class idle_sched_class;
1244
1245
1246 #ifdef CONFIG_SMP
1247
1248 extern void update_group_capacity(struct sched_domain *sd, int cpu);
1249
1250 extern void trigger_load_balance(struct rq *rq);
1251
1252 extern void idle_enter_fair(struct rq *this_rq);
1253 extern void idle_exit_fair(struct rq *this_rq);
1254
1255 extern void set_cpus_allowed_common(struct task_struct *p, const struct cpumask *new_mask);
1256
1257 #else
1258
1259 static inline void idle_enter_fair(struct rq *rq) { }
1260 static inline void idle_exit_fair(struct rq *rq) { }
1261
1262 #endif
1263
1264 #ifdef CONFIG_CPU_IDLE
1265 static inline void idle_set_state(struct rq *rq,
1266 struct cpuidle_state *idle_state)
1267 {
1268 rq->idle_state = idle_state;
1269 }
1270
1271 static inline struct cpuidle_state *idle_get_state(struct rq *rq)
1272 {
1273 WARN_ON(!rcu_read_lock_held());
1274 return rq->idle_state;
1275 }
1276 #else
1277 static inline void idle_set_state(struct rq *rq,
1278 struct cpuidle_state *idle_state)
1279 {
1280 }
1281
1282 static inline struct cpuidle_state *idle_get_state(struct rq *rq)
1283 {
1284 return NULL;
1285 }
1286 #endif
1287
1288 extern void sysrq_sched_debug_show(void);
1289 extern void sched_init_granularity(void);
1290 extern void update_max_interval(void);
1291
1292 extern void init_sched_dl_class(void);
1293 extern void init_sched_rt_class(void);
1294 extern void init_sched_fair_class(void);
1295
1296 extern void resched_curr(struct rq *rq);
1297 extern void resched_cpu(int cpu);
1298
1299 extern struct rt_bandwidth def_rt_bandwidth;
1300 extern void init_rt_bandwidth(struct rt_bandwidth *rt_b, u64 period, u64 runtime);
1301
1302 extern struct dl_bandwidth def_dl_bandwidth;
1303 extern void init_dl_bandwidth(struct dl_bandwidth *dl_b, u64 period, u64 runtime);
1304 extern void init_dl_task_timer(struct sched_dl_entity *dl_se);
1305
1306 unsigned long to_ratio(u64 period, u64 runtime);
1307
1308 extern void init_entity_runnable_average(struct sched_entity *se);
1309
1310 static inline void add_nr_running(struct rq *rq, unsigned count)
1311 {
1312 unsigned prev_nr = rq->nr_running;
1313
1314 rq->nr_running = prev_nr + count;
1315
1316 if (prev_nr < 2 && rq->nr_running >= 2) {
1317 #ifdef CONFIG_SMP
1318 if (!rq->rd->overload)
1319 rq->rd->overload = true;
1320 #endif
1321
1322 #ifdef CONFIG_NO_HZ_FULL
1323 if (tick_nohz_full_cpu(rq->cpu)) {
1324 /*
1325 * Tick is needed if more than one task runs on a CPU.
1326 * Send the target an IPI to kick it out of nohz mode.
1327 *
1328 * We assume that IPI implies full memory barrier and the
1329 * new value of rq->nr_running is visible on reception
1330 * from the target.
1331 */
1332 tick_nohz_full_kick_cpu(rq->cpu);
1333 }
1334 #endif
1335 }
1336 }
1337
1338 static inline void sub_nr_running(struct rq *rq, unsigned count)
1339 {
1340 rq->nr_running -= count;
1341 }
1342
1343 static inline void rq_last_tick_reset(struct rq *rq)
1344 {
1345 #ifdef CONFIG_NO_HZ_FULL
1346 rq->last_sched_tick = jiffies;
1347 #endif
1348 }
1349
1350 extern void update_rq_clock(struct rq *rq);
1351
1352 extern void activate_task(struct rq *rq, struct task_struct *p, int flags);
1353 extern void deactivate_task(struct rq *rq, struct task_struct *p, int flags);
1354
1355 extern void check_preempt_curr(struct rq *rq, struct task_struct *p, int flags);
1356
1357 extern const_debug unsigned int sysctl_sched_time_avg;
1358 extern const_debug unsigned int sysctl_sched_nr_migrate;
1359 extern const_debug unsigned int sysctl_sched_migration_cost;
1360
1361 static inline u64 sched_avg_period(void)
1362 {
1363 return (u64)sysctl_sched_time_avg * NSEC_PER_MSEC / 2;
1364 }
1365
1366 #ifdef CONFIG_SCHED_HRTICK
1367
1368 /*
1369 * Use hrtick when:
1370 * - enabled by features
1371 * - hrtimer is actually high res
1372 */
1373 static inline int hrtick_enabled(struct rq *rq)
1374 {
1375 if (!sched_feat(HRTICK))
1376 return 0;
1377 if (!cpu_active(cpu_of(rq)))
1378 return 0;
1379 return hrtimer_is_hres_active(&rq->hrtick_timer);
1380 }
1381
1382 void hrtick_start(struct rq *rq, u64 delay);
1383
1384 #else
1385
1386 static inline int hrtick_enabled(struct rq *rq)
1387 {
1388 return 0;
1389 }
1390
1391 #endif /* CONFIG_SCHED_HRTICK */
1392
1393 #ifdef CONFIG_SMP
1394 extern void sched_avg_update(struct rq *rq);
1395
1396 #ifndef arch_scale_freq_capacity
1397 static __always_inline
1398 unsigned long arch_scale_freq_capacity(struct sched_domain *sd, int cpu)
1399 {
1400 return SCHED_CAPACITY_SCALE;
1401 }
1402 #endif
1403
1404 #ifndef arch_scale_cpu_capacity
1405 static __always_inline
1406 unsigned long arch_scale_cpu_capacity(struct sched_domain *sd, int cpu)
1407 {
1408 if (sd && (sd->flags & SD_SHARE_CPUCAPACITY) && (sd->span_weight > 1))
1409 return sd->smt_gain / sd->span_weight;
1410
1411 return SCHED_CAPACITY_SCALE;
1412 }
1413 #endif
1414
1415 static inline void sched_rt_avg_update(struct rq *rq, u64 rt_delta)
1416 {
1417 rq->rt_avg += rt_delta * arch_scale_freq_capacity(NULL, cpu_of(rq));
1418 sched_avg_update(rq);
1419 }
1420 #else
1421 static inline void sched_rt_avg_update(struct rq *rq, u64 rt_delta) { }
1422 static inline void sched_avg_update(struct rq *rq) { }
1423 #endif
1424
1425 /*
1426 * __task_rq_lock - lock the rq @p resides on.
1427 */
1428 static inline struct rq *__task_rq_lock(struct task_struct *p)
1429 __acquires(rq->lock)
1430 {
1431 struct rq *rq;
1432
1433 lockdep_assert_held(&p->pi_lock);
1434
1435 for (;;) {
1436 rq = task_rq(p);
1437 raw_spin_lock(&rq->lock);
1438 if (likely(rq == task_rq(p) && !task_on_rq_migrating(p))) {
1439 lockdep_pin_lock(&rq->lock);
1440 return rq;
1441 }
1442 raw_spin_unlock(&rq->lock);
1443
1444 while (unlikely(task_on_rq_migrating(p)))
1445 cpu_relax();
1446 }
1447 }
1448
1449 /*
1450 * task_rq_lock - lock p->pi_lock and lock the rq @p resides on.
1451 */
1452 static inline struct rq *task_rq_lock(struct task_struct *p, unsigned long *flags)
1453 __acquires(p->pi_lock)
1454 __acquires(rq->lock)
1455 {
1456 struct rq *rq;
1457
1458 for (;;) {
1459 raw_spin_lock_irqsave(&p->pi_lock, *flags);
1460 rq = task_rq(p);
1461 raw_spin_lock(&rq->lock);
1462 /*
1463 * move_queued_task() task_rq_lock()
1464 *
1465 * ACQUIRE (rq->lock)
1466 * [S] ->on_rq = MIGRATING [L] rq = task_rq()
1467 * WMB (__set_task_cpu()) ACQUIRE (rq->lock);
1468 * [S] ->cpu = new_cpu [L] task_rq()
1469 * [L] ->on_rq
1470 * RELEASE (rq->lock)
1471 *
1472 * If we observe the old cpu in task_rq_lock, the acquire of
1473 * the old rq->lock will fully serialize against the stores.
1474 *
1475 * If we observe the new cpu in task_rq_lock, the acquire will
1476 * pair with the WMB to ensure we must then also see migrating.
1477 */
1478 if (likely(rq == task_rq(p) && !task_on_rq_migrating(p))) {
1479 lockdep_pin_lock(&rq->lock);
1480 return rq;
1481 }
1482 raw_spin_unlock(&rq->lock);
1483 raw_spin_unlock_irqrestore(&p->pi_lock, *flags);
1484
1485 while (unlikely(task_on_rq_migrating(p)))
1486 cpu_relax();
1487 }
1488 }
1489
1490 static inline void __task_rq_unlock(struct rq *rq)
1491 __releases(rq->lock)
1492 {
1493 lockdep_unpin_lock(&rq->lock);
1494 raw_spin_unlock(&rq->lock);
1495 }
1496
1497 static inline void
1498 task_rq_unlock(struct rq *rq, struct task_struct *p, unsigned long *flags)
1499 __releases(rq->lock)
1500 __releases(p->pi_lock)
1501 {
1502 lockdep_unpin_lock(&rq->lock);
1503 raw_spin_unlock(&rq->lock);
1504 raw_spin_unlock_irqrestore(&p->pi_lock, *flags);
1505 }
1506
1507 #ifdef CONFIG_SMP
1508 #ifdef CONFIG_PREEMPT
1509
1510 static inline void double_rq_lock(struct rq *rq1, struct rq *rq2);
1511
1512 /*
1513 * fair double_lock_balance: Safely acquires both rq->locks in a fair
1514 * way at the expense of forcing extra atomic operations in all
1515 * invocations. This assures that the double_lock is acquired using the
1516 * same underlying policy as the spinlock_t on this architecture, which
1517 * reduces latency compared to the unfair variant below. However, it
1518 * also adds more overhead and therefore may reduce throughput.
1519 */
1520 static inline int _double_lock_balance(struct rq *this_rq, struct rq *busiest)
1521 __releases(this_rq->lock)
1522 __acquires(busiest->lock)
1523 __acquires(this_rq->lock)
1524 {
1525 raw_spin_unlock(&this_rq->lock);
1526 double_rq_lock(this_rq, busiest);
1527
1528 return 1;
1529 }
1530
1531 #else
1532 /*
1533 * Unfair double_lock_balance: Optimizes throughput at the expense of
1534 * latency by eliminating extra atomic operations when the locks are
1535 * already in proper order on entry. This favors lower cpu-ids and will
1536 * grant the double lock to lower cpus over higher ids under contention,
1537 * regardless of entry order into the function.
1538 */
1539 static inline int _double_lock_balance(struct rq *this_rq, struct rq *busiest)
1540 __releases(this_rq->lock)
1541 __acquires(busiest->lock)
1542 __acquires(this_rq->lock)
1543 {
1544 int ret = 0;
1545
1546 if (unlikely(!raw_spin_trylock(&busiest->lock))) {
1547 if (busiest < this_rq) {
1548 raw_spin_unlock(&this_rq->lock);
1549 raw_spin_lock(&busiest->lock);
1550 raw_spin_lock_nested(&this_rq->lock,
1551 SINGLE_DEPTH_NESTING);
1552 ret = 1;
1553 } else
1554 raw_spin_lock_nested(&busiest->lock,
1555 SINGLE_DEPTH_NESTING);
1556 }
1557 return ret;
1558 }
1559
1560 #endif /* CONFIG_PREEMPT */
1561
1562 /*
1563 * double_lock_balance - lock the busiest runqueue, this_rq is locked already.
1564 */
1565 static inline int double_lock_balance(struct rq *this_rq, struct rq *busiest)
1566 {
1567 if (unlikely(!irqs_disabled())) {
1568 /* printk() doesn't work good under rq->lock */
1569 raw_spin_unlock(&this_rq->lock);
1570 BUG_ON(1);
1571 }
1572
1573 return _double_lock_balance(this_rq, busiest);
1574 }
1575
1576 static inline void double_unlock_balance(struct rq *this_rq, struct rq *busiest)
1577 __releases(busiest->lock)
1578 {
1579 raw_spin_unlock(&busiest->lock);
1580 lock_set_subclass(&this_rq->lock.dep_map, 0, _RET_IP_);
1581 }
1582
1583 static inline void double_lock(spinlock_t *l1, spinlock_t *l2)
1584 {
1585 if (l1 > l2)
1586 swap(l1, l2);
1587
1588 spin_lock(l1);
1589 spin_lock_nested(l2, SINGLE_DEPTH_NESTING);
1590 }
1591
1592 static inline void double_lock_irq(spinlock_t *l1, spinlock_t *l2)
1593 {
1594 if (l1 > l2)
1595 swap(l1, l2);
1596
1597 spin_lock_irq(l1);
1598 spin_lock_nested(l2, SINGLE_DEPTH_NESTING);
1599 }
1600
1601 static inline void double_raw_lock(raw_spinlock_t *l1, raw_spinlock_t *l2)
1602 {
1603 if (l1 > l2)
1604 swap(l1, l2);
1605
1606 raw_spin_lock(l1);
1607 raw_spin_lock_nested(l2, SINGLE_DEPTH_NESTING);
1608 }
1609
1610 /*
1611 * double_rq_lock - safely lock two runqueues
1612 *
1613 * Note this does not disable interrupts like task_rq_lock,
1614 * you need to do so manually before calling.
1615 */
1616 static inline void double_rq_lock(struct rq *rq1, struct rq *rq2)
1617 __acquires(rq1->lock)
1618 __acquires(rq2->lock)
1619 {
1620 BUG_ON(!irqs_disabled());
1621 if (rq1 == rq2) {
1622 raw_spin_lock(&rq1->lock);
1623 __acquire(rq2->lock); /* Fake it out ;) */
1624 } else {
1625 if (rq1 < rq2) {
1626 raw_spin_lock(&rq1->lock);
1627 raw_spin_lock_nested(&rq2->lock, SINGLE_DEPTH_NESTING);
1628 } else {
1629 raw_spin_lock(&rq2->lock);
1630 raw_spin_lock_nested(&rq1->lock, SINGLE_DEPTH_NESTING);
1631 }
1632 }
1633 }
1634
1635 /*
1636 * double_rq_unlock - safely unlock two runqueues
1637 *
1638 * Note this does not restore interrupts like task_rq_unlock,
1639 * you need to do so manually after calling.
1640 */
1641 static inline void double_rq_unlock(struct rq *rq1, struct rq *rq2)
1642 __releases(rq1->lock)
1643 __releases(rq2->lock)
1644 {
1645 raw_spin_unlock(&rq1->lock);
1646 if (rq1 != rq2)
1647 raw_spin_unlock(&rq2->lock);
1648 else
1649 __release(rq2->lock);
1650 }
1651
1652 #else /* CONFIG_SMP */
1653
1654 /*
1655 * double_rq_lock - safely lock two runqueues
1656 *
1657 * Note this does not disable interrupts like task_rq_lock,
1658 * you need to do so manually before calling.
1659 */
1660 static inline void double_rq_lock(struct rq *rq1, struct rq *rq2)
1661 __acquires(rq1->lock)
1662 __acquires(rq2->lock)
1663 {
1664 BUG_ON(!irqs_disabled());
1665 BUG_ON(rq1 != rq2);
1666 raw_spin_lock(&rq1->lock);
1667 __acquire(rq2->lock); /* Fake it out ;) */
1668 }
1669
1670 /*
1671 * double_rq_unlock - safely unlock two runqueues
1672 *
1673 * Note this does not restore interrupts like task_rq_unlock,
1674 * you need to do so manually after calling.
1675 */
1676 static inline void double_rq_unlock(struct rq *rq1, struct rq *rq2)
1677 __releases(rq1->lock)
1678 __releases(rq2->lock)
1679 {
1680 BUG_ON(rq1 != rq2);
1681 raw_spin_unlock(&rq1->lock);
1682 __release(rq2->lock);
1683 }
1684
1685 #endif
1686
1687 extern struct sched_entity *__pick_first_entity(struct cfs_rq *cfs_rq);
1688 extern struct sched_entity *__pick_last_entity(struct cfs_rq *cfs_rq);
1689
1690 #ifdef CONFIG_SCHED_DEBUG
1691 extern void print_cfs_stats(struct seq_file *m, int cpu);
1692 extern void print_rt_stats(struct seq_file *m, int cpu);
1693 extern void print_dl_stats(struct seq_file *m, int cpu);
1694 extern void
1695 print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq);
1696
1697 #ifdef CONFIG_NUMA_BALANCING
1698 extern void
1699 show_numa_stats(struct task_struct *p, struct seq_file *m);
1700 extern void
1701 print_numa_stats(struct seq_file *m, int node, unsigned long tsf,
1702 unsigned long tpf, unsigned long gsf, unsigned long gpf);
1703 #endif /* CONFIG_NUMA_BALANCING */
1704 #endif /* CONFIG_SCHED_DEBUG */
1705
1706 extern void init_cfs_rq(struct cfs_rq *cfs_rq);
1707 extern void init_rt_rq(struct rt_rq *rt_rq);
1708 extern void init_dl_rq(struct dl_rq *dl_rq);
1709
1710 extern void cfs_bandwidth_usage_inc(void);
1711 extern void cfs_bandwidth_usage_dec(void);
1712
1713 #ifdef CONFIG_NO_HZ_COMMON
1714 enum rq_nohz_flag_bits {
1715 NOHZ_TICK_STOPPED,
1716 NOHZ_BALANCE_KICK,
1717 };
1718
1719 #define nohz_flags(cpu) (&cpu_rq(cpu)->nohz_flags)
1720 #endif
1721
1722 #ifdef CONFIG_IRQ_TIME_ACCOUNTING
1723
1724 DECLARE_PER_CPU(u64, cpu_hardirq_time);
1725 DECLARE_PER_CPU(u64, cpu_softirq_time);
1726
1727 #ifndef CONFIG_64BIT
1728 DECLARE_PER_CPU(seqcount_t, irq_time_seq);
1729
1730 static inline void irq_time_write_begin(void)
1731 {
1732 __this_cpu_inc(irq_time_seq.sequence);
1733 smp_wmb();
1734 }
1735
1736 static inline void irq_time_write_end(void)
1737 {
1738 smp_wmb();
1739 __this_cpu_inc(irq_time_seq.sequence);
1740 }
1741
1742 static inline u64 irq_time_read(int cpu)
1743 {
1744 u64 irq_time;
1745 unsigned seq;
1746
1747 do {
1748 seq = read_seqcount_begin(&per_cpu(irq_time_seq, cpu));
1749 irq_time = per_cpu(cpu_softirq_time, cpu) +
1750 per_cpu(cpu_hardirq_time, cpu);
1751 } while (read_seqcount_retry(&per_cpu(irq_time_seq, cpu), seq));
1752
1753 return irq_time;
1754 }
1755 #else /* CONFIG_64BIT */
1756 static inline void irq_time_write_begin(void)
1757 {
1758 }
1759
1760 static inline void irq_time_write_end(void)
1761 {
1762 }
1763
1764 static inline u64 irq_time_read(int cpu)
1765 {
1766 return per_cpu(cpu_softirq_time, cpu) + per_cpu(cpu_hardirq_time, cpu);
1767 }
1768 #endif /* CONFIG_64BIT */
1769 #endif /* CONFIG_IRQ_TIME_ACCOUNTING */
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