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