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 long calc_load_fold_active(struct rq *this_rq); 30 extern void update_cpu_load_active(struct rq *this_rq); 31 32 /* 33 * Helpers for converting nanosecond timing to jiffy resolution 34 */ 35 #define NS_TO_JIFFIES(TIME) ((unsigned long)(TIME) / (NSEC_PER_SEC / HZ)) 36 37 /* 38 * Increase resolution of nice-level calculations for 64-bit architectures. 39 * The extra resolution improves shares distribution and load balancing of 40 * low-weight task groups (eg. nice +19 on an autogroup), deeper taskgroup 41 * hierarchies, especially on larger systems. This is not a user-visible change 42 * and does not change the user-interface for setting shares/weights. 43 * 44 * We increase resolution only if we have enough bits to allow this increased 45 * resolution (i.e. BITS_PER_LONG > 32). The costs for increasing resolution 46 * when BITS_PER_LONG <= 32 are pretty high and the returns do not justify the 47 * increased costs. 48 */ 49 #if 0 /* BITS_PER_LONG > 32 -- currently broken: it increases power usage under light load */ 50 # define SCHED_LOAD_RESOLUTION 10 51 # define scale_load(w) ((w) << SCHED_LOAD_RESOLUTION) 52 # define scale_load_down(w) ((w) >> SCHED_LOAD_RESOLUTION) 53 #else 54 # define SCHED_LOAD_RESOLUTION 0 55 # define scale_load(w) (w) 56 # define scale_load_down(w) (w) 57 #endif 58 59 #define SCHED_LOAD_SHIFT (10 + SCHED_LOAD_RESOLUTION) 60 #define SCHED_LOAD_SCALE (1L << SCHED_LOAD_SHIFT) 61 62 #define NICE_0_LOAD SCHED_LOAD_SCALE 63 #define NICE_0_SHIFT SCHED_LOAD_SHIFT 64 65 /* 66 * Single value that decides SCHED_DEADLINE internal math precision. 67 * 10 -> just above 1us 68 * 9 -> just above 0.5us 69 */ 70 #define DL_SCALE (10) 71 72 /* 73 * These are the 'tuning knobs' of the scheduler: 74 */ 75 76 /* 77 * single value that denotes runtime == period, ie unlimited time. 78 */ 79 #define RUNTIME_INF ((u64)~0ULL) 80 81 static inline int fair_policy(int policy) 82 { 83 return policy == SCHED_NORMAL || policy == SCHED_BATCH; 84 } 85 86 static inline int rt_policy(int policy) 87 { 88 return policy == SCHED_FIFO || policy == SCHED_RR; 89 } 90 91 static inline int dl_policy(int policy) 92 { 93 return policy == SCHED_DEADLINE; 94 } 95 96 static inline int task_has_rt_policy(struct task_struct *p) 97 { 98 return rt_policy(p->policy); 99 } 100 101 static inline int task_has_dl_policy(struct task_struct *p) 102 { 103 return dl_policy(p->policy); 104 } 105 106 static inline bool dl_time_before(u64 a, u64 b) 107 { 108 return (s64)(a - b) < 0; 109 } 110 111 /* 112 * Tells if entity @a should preempt entity @b. 113 */ 114 static inline bool 115 dl_entity_preempt(struct sched_dl_entity *a, struct sched_dl_entity *b) 116 { 117 return dl_time_before(a->deadline, b->deadline); 118 } 119 120 /* 121 * This is the priority-queue data structure of the RT scheduling class: 122 */ 123 struct rt_prio_array { 124 DECLARE_BITMAP(bitmap, MAX_RT_PRIO+1); /* include 1 bit for delimiter */ 125 struct list_head queue[MAX_RT_PRIO]; 126 }; 127 128 struct rt_bandwidth { 129 /* nests inside the rq lock: */ 130 raw_spinlock_t rt_runtime_lock; 131 ktime_t rt_period; 132 u64 rt_runtime; 133 struct hrtimer rt_period_timer; 134 }; 135 136 void __dl_clear_params(struct task_struct *p); 137 138 /* 139 * To keep the bandwidth of -deadline tasks and groups under control 140 * we need some place where: 141 * - store the maximum -deadline bandwidth of the system (the group); 142 * - cache the fraction of that bandwidth that is currently allocated. 143 * 144 * This is all done in the data structure below. It is similar to the 145 * one used for RT-throttling (rt_bandwidth), with the main difference 146 * that, since here we are only interested in admission control, we 147 * do not decrease any runtime while the group "executes", neither we 148 * need a timer to replenish it. 149 * 150 * With respect to SMP, the bandwidth is given on a per-CPU basis, 151 * meaning that: 152 * - dl_bw (< 100%) is the bandwidth of the system (group) on each CPU; 153 * - dl_total_bw array contains, in the i-eth element, the currently 154 * allocated bandwidth on the i-eth CPU. 155 * Moreover, groups consume bandwidth on each CPU, while tasks only 156 * consume bandwidth on the CPU they're running on. 157 * Finally, dl_total_bw_cpu is used to cache the index of dl_total_bw 158 * that will be shown the next time the proc or cgroup controls will 159 * be red. It on its turn can be changed by writing on its own 160 * control. 161 */ 162 struct dl_bandwidth { 163 raw_spinlock_t dl_runtime_lock; 164 u64 dl_runtime; 165 u64 dl_period; 166 }; 167 168 static inline int dl_bandwidth_enabled(void) 169 { 170 return sysctl_sched_rt_runtime >= 0; 171 } 172 173 extern struct dl_bw *dl_bw_of(int i); 174 175 struct dl_bw { 176 raw_spinlock_t lock; 177 u64 bw, total_bw; 178 }; 179 180 static inline 181 void __dl_clear(struct dl_bw *dl_b, u64 tsk_bw) 182 { 183 dl_b->total_bw -= tsk_bw; 184 } 185 186 static inline 187 void __dl_add(struct dl_bw *dl_b, u64 tsk_bw) 188 { 189 dl_b->total_bw += tsk_bw; 190 } 191 192 static inline 193 bool __dl_overflow(struct dl_bw *dl_b, int cpus, u64 old_bw, u64 new_bw) 194 { 195 return dl_b->bw != -1 && 196 dl_b->bw * cpus < dl_b->total_bw - old_bw + new_bw; 197 } 198 199 extern struct mutex sched_domains_mutex; 200 201 #ifdef CONFIG_CGROUP_SCHED 202 203 #include <linux/cgroup.h> 204 205 struct cfs_rq; 206 struct rt_rq; 207 208 extern struct list_head task_groups; 209 210 struct cfs_bandwidth { 211 #ifdef CONFIG_CFS_BANDWIDTH 212 raw_spinlock_t lock; 213 ktime_t period; 214 u64 quota, runtime; 215 s64 hierarchical_quota; 216 u64 runtime_expires; 217 218 int idle, timer_active; 219 struct hrtimer period_timer, slack_timer; 220 struct list_head throttled_cfs_rq; 221 222 /* statistics */ 223 int nr_periods, nr_throttled; 224 u64 throttled_time; 225 #endif 226 }; 227 228 /* task group related information */ 229 struct task_group { 230 struct cgroup_subsys_state css; 231 232 #ifdef CONFIG_FAIR_GROUP_SCHED 233 /* schedulable entities of this group on each cpu */ 234 struct sched_entity **se; 235 /* runqueue "owned" by this group on each cpu */ 236 struct cfs_rq **cfs_rq; 237 unsigned long shares; 238 239 #ifdef CONFIG_SMP 240 atomic_long_t load_avg; 241 atomic_t runnable_avg; 242 #endif 243 #endif 244 245 #ifdef CONFIG_RT_GROUP_SCHED 246 struct sched_rt_entity **rt_se; 247 struct rt_rq **rt_rq; 248 249 struct rt_bandwidth rt_bandwidth; 250 #endif 251 252 struct rcu_head rcu; 253 struct list_head list; 254 255 struct task_group *parent; 256 struct list_head siblings; 257 struct list_head children; 258 259 #ifdef CONFIG_SCHED_AUTOGROUP 260 struct autogroup *autogroup; 261 #endif 262 263 struct cfs_bandwidth cfs_bandwidth; 264 }; 265 266 #ifdef CONFIG_FAIR_GROUP_SCHED 267 #define ROOT_TASK_GROUP_LOAD NICE_0_LOAD 268 269 /* 270 * A weight of 0 or 1 can cause arithmetics problems. 271 * A weight of a cfs_rq is the sum of weights of which entities 272 * are queued on this cfs_rq, so a weight of a entity should not be 273 * too large, so as the shares value of a task group. 274 * (The default weight is 1024 - so there's no practical 275 * limitation from this.) 276 */ 277 #define MIN_SHARES (1UL << 1) 278 #define MAX_SHARES (1UL << 18) 279 #endif 280 281 typedef int (*tg_visitor)(struct task_group *, void *); 282 283 extern int walk_tg_tree_from(struct task_group *from, 284 tg_visitor down, tg_visitor up, void *data); 285 286 /* 287 * Iterate the full tree, calling @down when first entering a node and @up when 288 * leaving it for the final time. 289 * 290 * Caller must hold rcu_lock or sufficient equivalent. 291 */ 292 static inline int walk_tg_tree(tg_visitor down, tg_visitor up, void *data) 293 { 294 return walk_tg_tree_from(&root_task_group, down, up, data); 295 } 296 297 extern int tg_nop(struct task_group *tg, void *data); 298 299 extern void free_fair_sched_group(struct task_group *tg); 300 extern int alloc_fair_sched_group(struct task_group *tg, struct task_group *parent); 301 extern void unregister_fair_sched_group(struct task_group *tg, int cpu); 302 extern void init_tg_cfs_entry(struct task_group *tg, struct cfs_rq *cfs_rq, 303 struct sched_entity *se, int cpu, 304 struct sched_entity *parent); 305 extern void init_cfs_bandwidth(struct cfs_bandwidth *cfs_b); 306 extern int sched_group_set_shares(struct task_group *tg, unsigned long shares); 307 308 extern void __refill_cfs_bandwidth_runtime(struct cfs_bandwidth *cfs_b); 309 extern void __start_cfs_bandwidth(struct cfs_bandwidth *cfs_b, bool force); 310 extern void unthrottle_cfs_rq(struct cfs_rq *cfs_rq); 311 312 extern void free_rt_sched_group(struct task_group *tg); 313 extern int alloc_rt_sched_group(struct task_group *tg, struct task_group *parent); 314 extern void init_tg_rt_entry(struct task_group *tg, struct rt_rq *rt_rq, 315 struct sched_rt_entity *rt_se, int cpu, 316 struct sched_rt_entity *parent); 317 318 extern struct task_group *sched_create_group(struct task_group *parent); 319 extern void sched_online_group(struct task_group *tg, 320 struct task_group *parent); 321 extern void sched_destroy_group(struct task_group *tg); 322 extern void sched_offline_group(struct task_group *tg); 323 324 extern void sched_move_task(struct task_struct *tsk); 325 326 #ifdef CONFIG_FAIR_GROUP_SCHED 327 extern int sched_group_set_shares(struct task_group *tg, unsigned long shares); 328 #endif 329 330 #else /* CONFIG_CGROUP_SCHED */ 331 332 struct cfs_bandwidth { }; 333 334 #endif /* CONFIG_CGROUP_SCHED */ 335 336 /* CFS-related fields in a runqueue */ 337 struct cfs_rq { 338 struct load_weight load; 339 unsigned int nr_running, h_nr_running; 340 341 u64 exec_clock; 342 u64 min_vruntime; 343 #ifndef CONFIG_64BIT 344 u64 min_vruntime_copy; 345 #endif 346 347 struct rb_root tasks_timeline; 348 struct rb_node *rb_leftmost; 349 350 /* 351 * 'curr' points to currently running entity on this cfs_rq. 352 * It is set to NULL otherwise (i.e when none are currently running). 353 */ 354 struct sched_entity *curr, *next, *last, *skip; 355 356 #ifdef CONFIG_SCHED_DEBUG 357 unsigned int nr_spread_over; 358 #endif 359 360 #ifdef CONFIG_SMP 361 /* 362 * CFS Load tracking 363 * Under CFS, load is tracked on a per-entity basis and aggregated up. 364 * This allows for the description of both thread and group usage (in 365 * the FAIR_GROUP_SCHED case). 366 * runnable_load_avg is the sum of the load_avg_contrib of the 367 * sched_entities on the rq. 368 * blocked_load_avg is similar to runnable_load_avg except that its 369 * the blocked sched_entities on the rq. 370 * utilization_load_avg is the sum of the average running time of the 371 * sched_entities on the rq. 372 */ 373 unsigned long runnable_load_avg, blocked_load_avg, utilization_load_avg; 374 atomic64_t decay_counter; 375 u64 last_decay; 376 atomic_long_t removed_load; 377 378 #ifdef CONFIG_FAIR_GROUP_SCHED 379 /* Required to track per-cpu representation of a task_group */ 380 u32 tg_runnable_contrib; 381 unsigned long tg_load_contrib; 382 383 /* 384 * h_load = weight * f(tg) 385 * 386 * Where f(tg) is the recursive weight fraction assigned to 387 * this group. 388 */ 389 unsigned long h_load; 390 u64 last_h_load_update; 391 struct sched_entity *h_load_next; 392 #endif /* CONFIG_FAIR_GROUP_SCHED */ 393 #endif /* CONFIG_SMP */ 394 395 #ifdef CONFIG_FAIR_GROUP_SCHED 396 struct rq *rq; /* cpu runqueue to which this cfs_rq is attached */ 397 398 /* 399 * leaf cfs_rqs are those that hold tasks (lowest schedulable entity in 400 * a hierarchy). Non-leaf lrqs hold other higher schedulable entities 401 * (like users, containers etc.) 402 * 403 * leaf_cfs_rq_list ties together list of leaf cfs_rq's in a cpu. This 404 * list is used during load balance. 405 */ 406 int on_list; 407 struct list_head leaf_cfs_rq_list; 408 struct task_group *tg; /* group that "owns" this runqueue */ 409 410 #ifdef CONFIG_CFS_BANDWIDTH 411 int runtime_enabled; 412 u64 runtime_expires; 413 s64 runtime_remaining; 414 415 u64 throttled_clock, throttled_clock_task; 416 u64 throttled_clock_task_time; 417 int throttled, throttle_count; 418 struct list_head throttled_list; 419 #endif /* CONFIG_CFS_BANDWIDTH */ 420 #endif /* CONFIG_FAIR_GROUP_SCHED */ 421 }; 422 423 static inline int rt_bandwidth_enabled(void) 424 { 425 return sysctl_sched_rt_runtime >= 0; 426 } 427 428 /* RT IPI pull logic requires IRQ_WORK */ 429 #ifdef CONFIG_IRQ_WORK 430 # define HAVE_RT_PUSH_IPI 431 #endif 432 433 /* Real-Time classes' related field in a runqueue: */ 434 struct rt_rq { 435 struct rt_prio_array active; 436 unsigned int rt_nr_running; 437 #if defined CONFIG_SMP || defined CONFIG_RT_GROUP_SCHED 438 struct { 439 int curr; /* highest queued rt task prio */ 440 #ifdef CONFIG_SMP 441 int next; /* next highest */ 442 #endif 443 } highest_prio; 444 #endif 445 #ifdef CONFIG_SMP 446 unsigned long rt_nr_migratory; 447 unsigned long rt_nr_total; 448 int overloaded; 449 struct plist_head pushable_tasks; 450 #ifdef HAVE_RT_PUSH_IPI 451 int push_flags; 452 int push_cpu; 453 struct irq_work push_work; 454 raw_spinlock_t push_lock; 455 #endif 456 #endif /* CONFIG_SMP */ 457 int rt_queued; 458 459 int rt_throttled; 460 u64 rt_time; 461 u64 rt_runtime; 462 /* Nests inside the rq lock: */ 463 raw_spinlock_t rt_runtime_lock; 464 465 #ifdef CONFIG_RT_GROUP_SCHED 466 unsigned long rt_nr_boosted; 467 468 struct rq *rq; 469 struct task_group *tg; 470 #endif 471 }; 472 473 /* Deadline class' related fields in a runqueue */ 474 struct dl_rq { 475 /* runqueue is an rbtree, ordered by deadline */ 476 struct rb_root rb_root; 477 struct rb_node *rb_leftmost; 478 479 unsigned long dl_nr_running; 480 481 #ifdef CONFIG_SMP 482 /* 483 * Deadline values of the currently executing and the 484 * earliest ready task on this rq. Caching these facilitates 485 * the decision wether or not a ready but not running task 486 * should migrate somewhere else. 487 */ 488 struct { 489 u64 curr; 490 u64 next; 491 } earliest_dl; 492 493 unsigned long dl_nr_migratory; 494 int overloaded; 495 496 /* 497 * Tasks on this rq that can be pushed away. They are kept in 498 * an rb-tree, ordered by tasks' deadlines, with caching 499 * of the leftmost (earliest deadline) element. 500 */ 501 struct rb_root pushable_dl_tasks_root; 502 struct rb_node *pushable_dl_tasks_leftmost; 503 #else 504 struct dl_bw dl_bw; 505 #endif 506 }; 507 508 #ifdef CONFIG_SMP 509 510 /* 511 * We add the notion of a root-domain which will be used to define per-domain 512 * variables. Each exclusive cpuset essentially defines an island domain by 513 * fully partitioning the member cpus from any other cpuset. Whenever a new 514 * exclusive cpuset is created, we also create and attach a new root-domain 515 * object. 516 * 517 */ 518 struct root_domain { 519 atomic_t refcount; 520 atomic_t rto_count; 521 struct rcu_head rcu; 522 cpumask_var_t span; 523 cpumask_var_t online; 524 525 /* Indicate more than one runnable task for any CPU */ 526 bool overload; 527 528 /* 529 * The bit corresponding to a CPU gets set here if such CPU has more 530 * than one runnable -deadline task (as it is below for RT tasks). 531 */ 532 cpumask_var_t dlo_mask; 533 atomic_t dlo_count; 534 struct dl_bw dl_bw; 535 struct cpudl cpudl; 536 537 /* 538 * The "RT overload" flag: it gets set if a CPU has more than 539 * one runnable RT task. 540 */ 541 cpumask_var_t rto_mask; 542 struct cpupri cpupri; 543 }; 544 545 extern struct root_domain def_root_domain; 546 547 #endif /* CONFIG_SMP */ 548 549 /* 550 * This is the main, per-CPU runqueue data structure. 551 * 552 * Locking rule: those places that want to lock multiple runqueues 553 * (such as the load balancing or the thread migration code), lock 554 * acquire operations must be ordered by ascending &runqueue. 555 */ 556 struct rq { 557 /* runqueue lock: */ 558 raw_spinlock_t lock; 559 560 /* 561 * nr_running and cpu_load should be in the same cacheline because 562 * remote CPUs use both these fields when doing load calculation. 563 */ 564 unsigned int nr_running; 565 #ifdef CONFIG_NUMA_BALANCING 566 unsigned int nr_numa_running; 567 unsigned int nr_preferred_running; 568 #endif 569 #define CPU_LOAD_IDX_MAX 5 570 unsigned long cpu_load[CPU_LOAD_IDX_MAX]; 571 unsigned long last_load_update_tick; 572 #ifdef CONFIG_NO_HZ_COMMON 573 u64 nohz_stamp; 574 unsigned long nohz_flags; 575 #endif 576 #ifdef CONFIG_NO_HZ_FULL 577 unsigned long last_sched_tick; 578 #endif 579 /* capture load from *all* tasks on this cpu: */ 580 struct load_weight load; 581 unsigned long nr_load_updates; 582 u64 nr_switches; 583 584 struct cfs_rq cfs; 585 struct rt_rq rt; 586 struct dl_rq dl; 587 588 #ifdef CONFIG_FAIR_GROUP_SCHED 589 /* list of leaf cfs_rq on this cpu: */ 590 struct list_head leaf_cfs_rq_list; 591 592 struct sched_avg avg; 593 #endif /* CONFIG_FAIR_GROUP_SCHED */ 594 595 /* 596 * This is part of a global counter where only the total sum 597 * over all CPUs matters. A task can increase this counter on 598 * one CPU and if it got migrated afterwards it may decrease 599 * it on another CPU. Always updated under the runqueue lock: 600 */ 601 unsigned long nr_uninterruptible; 602 603 struct task_struct *curr, *idle, *stop; 604 unsigned long next_balance; 605 struct mm_struct *prev_mm; 606 607 unsigned int clock_skip_update; 608 u64 clock; 609 u64 clock_task; 610 611 atomic_t nr_iowait; 612 613 #ifdef CONFIG_SMP 614 struct root_domain *rd; 615 struct sched_domain *sd; 616 617 unsigned long cpu_capacity; 618 unsigned long cpu_capacity_orig; 619 620 unsigned char idle_balance; 621 /* For active balancing */ 622 int post_schedule; 623 int active_balance; 624 int push_cpu; 625 struct cpu_stop_work active_balance_work; 626 /* cpu of this runqueue: */ 627 int cpu; 628 int online; 629 630 struct list_head cfs_tasks; 631 632 u64 rt_avg; 633 u64 age_stamp; 634 u64 idle_stamp; 635 u64 avg_idle; 636 637 /* This is used to determine avg_idle's max value */ 638 u64 max_idle_balance_cost; 639 #endif 640 641 #ifdef CONFIG_IRQ_TIME_ACCOUNTING 642 u64 prev_irq_time; 643 #endif 644 #ifdef CONFIG_PARAVIRT 645 u64 prev_steal_time; 646 #endif 647 #ifdef CONFIG_PARAVIRT_TIME_ACCOUNTING 648 u64 prev_steal_time_rq; 649 #endif 650 651 /* calc_load related fields */ 652 unsigned long calc_load_update; 653 long calc_load_active; 654 655 #ifdef CONFIG_SCHED_HRTICK 656 #ifdef CONFIG_SMP 657 int hrtick_csd_pending; 658 struct call_single_data hrtick_csd; 659 #endif 660 struct hrtimer hrtick_timer; 661 #endif 662 663 #ifdef CONFIG_SCHEDSTATS 664 /* latency stats */ 665 struct sched_info rq_sched_info; 666 unsigned long long rq_cpu_time; 667 /* could above be rq->cfs_rq.exec_clock + rq->rt_rq.rt_runtime ? */ 668 669 /* sys_sched_yield() stats */ 670 unsigned int yld_count; 671 672 /* schedule() stats */ 673 unsigned int sched_count; 674 unsigned int sched_goidle; 675 676 /* try_to_wake_up() stats */ 677 unsigned int ttwu_count; 678 unsigned int ttwu_local; 679 #endif 680 681 #ifdef CONFIG_SMP 682 struct llist_head wake_list; 683 #endif 684 685 #ifdef CONFIG_CPU_IDLE 686 /* Must be inspected within a rcu lock section */ 687 struct cpuidle_state *idle_state; 688 #endif 689 }; 690 691 static inline int cpu_of(struct rq *rq) 692 { 693 #ifdef CONFIG_SMP 694 return rq->cpu; 695 #else 696 return 0; 697 #endif 698 } 699 700 DECLARE_PER_CPU_SHARED_ALIGNED(struct rq, runqueues); 701 702 #define cpu_rq(cpu) (&per_cpu(runqueues, (cpu))) 703 #define this_rq() this_cpu_ptr(&runqueues) 704 #define task_rq(p) cpu_rq(task_cpu(p)) 705 #define cpu_curr(cpu) (cpu_rq(cpu)->curr) 706 #define raw_rq() raw_cpu_ptr(&runqueues) 707 708 static inline u64 __rq_clock_broken(struct rq *rq) 709 { 710 return ACCESS_ONCE(rq->clock); 711 } 712 713 static inline u64 rq_clock(struct rq *rq) 714 { 715 lockdep_assert_held(&rq->lock); 716 return rq->clock; 717 } 718 719 static inline u64 rq_clock_task(struct rq *rq) 720 { 721 lockdep_assert_held(&rq->lock); 722 return rq->clock_task; 723 } 724 725 #define RQCF_REQ_SKIP 0x01 726 #define RQCF_ACT_SKIP 0x02 727 728 static inline void rq_clock_skip_update(struct rq *rq, bool skip) 729 { 730 lockdep_assert_held(&rq->lock); 731 if (skip) 732 rq->clock_skip_update |= RQCF_REQ_SKIP; 733 else 734 rq->clock_skip_update &= ~RQCF_REQ_SKIP; 735 } 736 737 #ifdef CONFIG_NUMA 738 enum numa_topology_type { 739 NUMA_DIRECT, 740 NUMA_GLUELESS_MESH, 741 NUMA_BACKPLANE, 742 }; 743 extern enum numa_topology_type sched_numa_topology_type; 744 extern int sched_max_numa_distance; 745 extern bool find_numa_distance(int distance); 746 #endif 747 748 #ifdef CONFIG_NUMA_BALANCING 749 /* The regions in numa_faults array from task_struct */ 750 enum numa_faults_stats { 751 NUMA_MEM = 0, 752 NUMA_CPU, 753 NUMA_MEMBUF, 754 NUMA_CPUBUF 755 }; 756 extern void sched_setnuma(struct task_struct *p, int node); 757 extern int migrate_task_to(struct task_struct *p, int cpu); 758 extern int migrate_swap(struct task_struct *, struct task_struct *); 759 #endif /* CONFIG_NUMA_BALANCING */ 760 761 #ifdef CONFIG_SMP 762 763 extern void sched_ttwu_pending(void); 764 765 #define rcu_dereference_check_sched_domain(p) \ 766 rcu_dereference_check((p), \ 767 lockdep_is_held(&sched_domains_mutex)) 768 769 /* 770 * The domain tree (rq->sd) is protected by RCU's quiescent state transition. 771 * See detach_destroy_domains: synchronize_sched for details. 772 * 773 * The domain tree of any CPU may only be accessed from within 774 * preempt-disabled sections. 775 */ 776 #define for_each_domain(cpu, __sd) \ 777 for (__sd = rcu_dereference_check_sched_domain(cpu_rq(cpu)->sd); \ 778 __sd; __sd = __sd->parent) 779 780 #define for_each_lower_domain(sd) for (; sd; sd = sd->child) 781 782 /** 783 * highest_flag_domain - Return highest sched_domain containing flag. 784 * @cpu: The cpu whose highest level of sched domain is to 785 * be returned. 786 * @flag: The flag to check for the highest sched_domain 787 * for the given cpu. 788 * 789 * Returns the highest sched_domain of a cpu which contains the given flag. 790 */ 791 static inline struct sched_domain *highest_flag_domain(int cpu, int flag) 792 { 793 struct sched_domain *sd, *hsd = NULL; 794 795 for_each_domain(cpu, sd) { 796 if (!(sd->flags & flag)) 797 break; 798 hsd = sd; 799 } 800 801 return hsd; 802 } 803 804 static inline struct sched_domain *lowest_flag_domain(int cpu, int flag) 805 { 806 struct sched_domain *sd; 807 808 for_each_domain(cpu, sd) { 809 if (sd->flags & flag) 810 break; 811 } 812 813 return sd; 814 } 815 816 DECLARE_PER_CPU(struct sched_domain *, sd_llc); 817 DECLARE_PER_CPU(int, sd_llc_size); 818 DECLARE_PER_CPU(int, sd_llc_id); 819 DECLARE_PER_CPU(struct sched_domain *, sd_numa); 820 DECLARE_PER_CPU(struct sched_domain *, sd_busy); 821 DECLARE_PER_CPU(struct sched_domain *, sd_asym); 822 823 struct sched_group_capacity { 824 atomic_t ref; 825 /* 826 * CPU capacity of this group, SCHED_LOAD_SCALE being max capacity 827 * for a single CPU. 828 */ 829 unsigned int capacity; 830 unsigned long next_update; 831 int imbalance; /* XXX unrelated to capacity but shared group state */ 832 /* 833 * Number of busy cpus in this group. 834 */ 835 atomic_t nr_busy_cpus; 836 837 unsigned long cpumask[0]; /* iteration mask */ 838 }; 839 840 struct sched_group { 841 struct sched_group *next; /* Must be a circular list */ 842 atomic_t ref; 843 844 unsigned int group_weight; 845 struct sched_group_capacity *sgc; 846 847 /* 848 * The CPUs this group covers. 849 * 850 * NOTE: this field is variable length. (Allocated dynamically 851 * by attaching extra space to the end of the structure, 852 * depending on how many CPUs the kernel has booted up with) 853 */ 854 unsigned long cpumask[0]; 855 }; 856 857 static inline struct cpumask *sched_group_cpus(struct sched_group *sg) 858 { 859 return to_cpumask(sg->cpumask); 860 } 861 862 /* 863 * cpumask masking which cpus in the group are allowed to iterate up the domain 864 * tree. 865 */ 866 static inline struct cpumask *sched_group_mask(struct sched_group *sg) 867 { 868 return to_cpumask(sg->sgc->cpumask); 869 } 870 871 /** 872 * group_first_cpu - Returns the first cpu in the cpumask of a sched_group. 873 * @group: The group whose first cpu is to be returned. 874 */ 875 static inline unsigned int group_first_cpu(struct sched_group *group) 876 { 877 return cpumask_first(sched_group_cpus(group)); 878 } 879 880 extern int group_balance_cpu(struct sched_group *sg); 881 882 #else 883 884 static inline void sched_ttwu_pending(void) { } 885 886 #endif /* CONFIG_SMP */ 887 888 #include "stats.h" 889 #include "auto_group.h" 890 891 #ifdef CONFIG_CGROUP_SCHED 892 893 /* 894 * Return the group to which this tasks belongs. 895 * 896 * We cannot use task_css() and friends because the cgroup subsystem 897 * changes that value before the cgroup_subsys::attach() method is called, 898 * therefore we cannot pin it and might observe the wrong value. 899 * 900 * The same is true for autogroup's p->signal->autogroup->tg, the autogroup 901 * core changes this before calling sched_move_task(). 902 * 903 * Instead we use a 'copy' which is updated from sched_move_task() while 904 * holding both task_struct::pi_lock and rq::lock. 905 */ 906 static inline struct task_group *task_group(struct task_struct *p) 907 { 908 return p->sched_task_group; 909 } 910 911 /* Change a task's cfs_rq and parent entity if it moves across CPUs/groups */ 912 static inline void set_task_rq(struct task_struct *p, unsigned int cpu) 913 { 914 #if defined(CONFIG_FAIR_GROUP_SCHED) || defined(CONFIG_RT_GROUP_SCHED) 915 struct task_group *tg = task_group(p); 916 #endif 917 918 #ifdef CONFIG_FAIR_GROUP_SCHED 919 p->se.cfs_rq = tg->cfs_rq[cpu]; 920 p->se.parent = tg->se[cpu]; 921 #endif 922 923 #ifdef CONFIG_RT_GROUP_SCHED 924 p->rt.rt_rq = tg->rt_rq[cpu]; 925 p->rt.parent = tg->rt_se[cpu]; 926 #endif 927 } 928 929 #else /* CONFIG_CGROUP_SCHED */ 930 931 static inline void set_task_rq(struct task_struct *p, unsigned int cpu) { } 932 static inline struct task_group *task_group(struct task_struct *p) 933 { 934 return NULL; 935 } 936 937 #endif /* CONFIG_CGROUP_SCHED */ 938 939 static inline void __set_task_cpu(struct task_struct *p, unsigned int cpu) 940 { 941 set_task_rq(p, cpu); 942 #ifdef CONFIG_SMP 943 /* 944 * After ->cpu is set up to a new value, task_rq_lock(p, ...) can be 945 * successfuly executed on another CPU. We must ensure that updates of 946 * per-task data have been completed by this moment. 947 */ 948 smp_wmb(); 949 task_thread_info(p)->cpu = cpu; 950 p->wake_cpu = cpu; 951 #endif 952 } 953 954 /* 955 * Tunables that become constants when CONFIG_SCHED_DEBUG is off: 956 */ 957 #ifdef CONFIG_SCHED_DEBUG 958 # include <linux/static_key.h> 959 # define const_debug __read_mostly 960 #else 961 # define const_debug const 962 #endif 963 964 extern const_debug unsigned int sysctl_sched_features; 965 966 #define SCHED_FEAT(name, enabled) \ 967 __SCHED_FEAT_##name , 968 969 enum { 970 #include "features.h" 971 __SCHED_FEAT_NR, 972 }; 973 974 #undef SCHED_FEAT 975 976 #if defined(CONFIG_SCHED_DEBUG) && defined(HAVE_JUMP_LABEL) 977 #define SCHED_FEAT(name, enabled) \ 978 static __always_inline bool static_branch_##name(struct static_key *key) \ 979 { \ 980 return static_key_##enabled(key); \ 981 } 982 983 #include "features.h" 984 985 #undef SCHED_FEAT 986 987 extern struct static_key sched_feat_keys[__SCHED_FEAT_NR]; 988 #define sched_feat(x) (static_branch_##x(&sched_feat_keys[__SCHED_FEAT_##x])) 989 #else /* !(SCHED_DEBUG && HAVE_JUMP_LABEL) */ 990 #define sched_feat(x) (sysctl_sched_features & (1UL << __SCHED_FEAT_##x)) 991 #endif /* SCHED_DEBUG && HAVE_JUMP_LABEL */ 992 993 #ifdef CONFIG_NUMA_BALANCING 994 #define sched_feat_numa(x) sched_feat(x) 995 #ifdef CONFIG_SCHED_DEBUG 996 #define numabalancing_enabled sched_feat_numa(NUMA) 997 #else 998 extern bool numabalancing_enabled; 999 #endif /* CONFIG_SCHED_DEBUG */ 1000 #else 1001 #define sched_feat_numa(x) (0) 1002 #define numabalancing_enabled (0) 1003 #endif /* CONFIG_NUMA_BALANCING */ 1004 1005 static inline u64 global_rt_period(void) 1006 { 1007 return (u64)sysctl_sched_rt_period * NSEC_PER_USEC; 1008 } 1009 1010 static inline u64 global_rt_runtime(void) 1011 { 1012 if (sysctl_sched_rt_runtime < 0) 1013 return RUNTIME_INF; 1014 1015 return (u64)sysctl_sched_rt_runtime * NSEC_PER_USEC; 1016 } 1017 1018 static inline int task_current(struct rq *rq, struct task_struct *p) 1019 { 1020 return rq->curr == p; 1021 } 1022 1023 static inline int task_running(struct rq *rq, struct task_struct *p) 1024 { 1025 #ifdef CONFIG_SMP 1026 return p->on_cpu; 1027 #else 1028 return task_current(rq, p); 1029 #endif 1030 } 1031 1032 static inline int task_on_rq_queued(struct task_struct *p) 1033 { 1034 return p->on_rq == TASK_ON_RQ_QUEUED; 1035 } 1036 1037 static inline int task_on_rq_migrating(struct task_struct *p) 1038 { 1039 return p->on_rq == TASK_ON_RQ_MIGRATING; 1040 } 1041 1042 #ifndef prepare_arch_switch 1043 # define prepare_arch_switch(next) do { } while (0) 1044 #endif 1045 #ifndef finish_arch_switch 1046 # define finish_arch_switch(prev) do { } while (0) 1047 #endif 1048 #ifndef finish_arch_post_lock_switch 1049 # define finish_arch_post_lock_switch() do { } while (0) 1050 #endif 1051 1052 static inline void prepare_lock_switch(struct rq *rq, struct task_struct *next) 1053 { 1054 #ifdef CONFIG_SMP 1055 /* 1056 * We can optimise this out completely for !SMP, because the 1057 * SMP rebalancing from interrupt is the only thing that cares 1058 * here. 1059 */ 1060 next->on_cpu = 1; 1061 #endif 1062 } 1063 1064 static inline void finish_lock_switch(struct rq *rq, struct task_struct *prev) 1065 { 1066 #ifdef CONFIG_SMP 1067 /* 1068 * After ->on_cpu is cleared, the task can be moved to a different CPU. 1069 * We must ensure this doesn't happen until the switch is completely 1070 * finished. 1071 */ 1072 smp_wmb(); 1073 prev->on_cpu = 0; 1074 #endif 1075 #ifdef CONFIG_DEBUG_SPINLOCK 1076 /* this is a valid case when another task releases the spinlock */ 1077 rq->lock.owner = current; 1078 #endif 1079 /* 1080 * If we are tracking spinlock dependencies then we have to 1081 * fix up the runqueue lock - which gets 'carried over' from 1082 * prev into current: 1083 */ 1084 spin_acquire(&rq->lock.dep_map, 0, 0, _THIS_IP_); 1085 1086 raw_spin_unlock_irq(&rq->lock); 1087 } 1088 1089 /* 1090 * wake flags 1091 */ 1092 #define WF_SYNC 0x01 /* waker goes to sleep after wakeup */ 1093 #define WF_FORK 0x02 /* child wakeup after fork */ 1094 #define WF_MIGRATED 0x4 /* internal use, task got migrated */ 1095 1096 /* 1097 * To aid in avoiding the subversion of "niceness" due to uneven distribution 1098 * of tasks with abnormal "nice" values across CPUs the contribution that 1099 * each task makes to its run queue's load is weighted according to its 1100 * scheduling class and "nice" value. For SCHED_NORMAL tasks this is just a 1101 * scaled version of the new time slice allocation that they receive on time 1102 * slice expiry etc. 1103 */ 1104 1105 #define WEIGHT_IDLEPRIO 3 1106 #define WMULT_IDLEPRIO 1431655765 1107 1108 /* 1109 * Nice levels are multiplicative, with a gentle 10% change for every 1110 * nice level changed. I.e. when a CPU-bound task goes from nice 0 to 1111 * nice 1, it will get ~10% less CPU time than another CPU-bound task 1112 * that remained on nice 0. 1113 * 1114 * The "10% effect" is relative and cumulative: from _any_ nice level, 1115 * if you go up 1 level, it's -10% CPU usage, if you go down 1 level 1116 * it's +10% CPU usage. (to achieve that we use a multiplier of 1.25. 1117 * If a task goes up by ~10% and another task goes down by ~10% then 1118 * the relative distance between them is ~25%.) 1119 */ 1120 static const int prio_to_weight[40] = { 1121 /* -20 */ 88761, 71755, 56483, 46273, 36291, 1122 /* -15 */ 29154, 23254, 18705, 14949, 11916, 1123 /* -10 */ 9548, 7620, 6100, 4904, 3906, 1124 /* -5 */ 3121, 2501, 1991, 1586, 1277, 1125 /* 0 */ 1024, 820, 655, 526, 423, 1126 /* 5 */ 335, 272, 215, 172, 137, 1127 /* 10 */ 110, 87, 70, 56, 45, 1128 /* 15 */ 36, 29, 23, 18, 15, 1129 }; 1130 1131 /* 1132 * Inverse (2^32/x) values of the prio_to_weight[] array, precalculated. 1133 * 1134 * In cases where the weight does not change often, we can use the 1135 * precalculated inverse to speed up arithmetics by turning divisions 1136 * into multiplications: 1137 */ 1138 static const u32 prio_to_wmult[40] = { 1139 /* -20 */ 48388, 59856, 76040, 92818, 118348, 1140 /* -15 */ 147320, 184698, 229616, 287308, 360437, 1141 /* -10 */ 449829, 563644, 704093, 875809, 1099582, 1142 /* -5 */ 1376151, 1717300, 2157191, 2708050, 3363326, 1143 /* 0 */ 4194304, 5237765, 6557202, 8165337, 10153587, 1144 /* 5 */ 12820798, 15790321, 19976592, 24970740, 31350126, 1145 /* 10 */ 39045157, 49367440, 61356676, 76695844, 95443717, 1146 /* 15 */ 119304647, 148102320, 186737708, 238609294, 286331153, 1147 }; 1148 1149 #define ENQUEUE_WAKEUP 1 1150 #define ENQUEUE_HEAD 2 1151 #ifdef CONFIG_SMP 1152 #define ENQUEUE_WAKING 4 /* sched_class::task_waking was called */ 1153 #else 1154 #define ENQUEUE_WAKING 0 1155 #endif 1156 #define ENQUEUE_REPLENISH 8 1157 1158 #define DEQUEUE_SLEEP 1 1159 1160 #define RETRY_TASK ((void *)-1UL) 1161 1162 struct sched_class { 1163 const struct sched_class *next; 1164 1165 void (*enqueue_task) (struct rq *rq, struct task_struct *p, int flags); 1166 void (*dequeue_task) (struct rq *rq, struct task_struct *p, int flags); 1167 void (*yield_task) (struct rq *rq); 1168 bool (*yield_to_task) (struct rq *rq, struct task_struct *p, bool preempt); 1169 1170 void (*check_preempt_curr) (struct rq *rq, struct task_struct *p, int flags); 1171 1172 /* 1173 * It is the responsibility of the pick_next_task() method that will 1174 * return the next task to call put_prev_task() on the @prev task or 1175 * something equivalent. 1176 * 1177 * May return RETRY_TASK when it finds a higher prio class has runnable 1178 * tasks. 1179 */ 1180 struct task_struct * (*pick_next_task) (struct rq *rq, 1181 struct task_struct *prev); 1182 void (*put_prev_task) (struct rq *rq, struct task_struct *p); 1183 1184 #ifdef CONFIG_SMP 1185 int (*select_task_rq)(struct task_struct *p, int task_cpu, int sd_flag, int flags); 1186 void (*migrate_task_rq)(struct task_struct *p, int next_cpu); 1187 1188 void (*post_schedule) (struct rq *this_rq); 1189 void (*task_waking) (struct task_struct *task); 1190 void (*task_woken) (struct rq *this_rq, struct task_struct *task); 1191 1192 void (*set_cpus_allowed)(struct task_struct *p, 1193 const struct cpumask *newmask); 1194 1195 void (*rq_online)(struct rq *rq); 1196 void (*rq_offline)(struct rq *rq); 1197 #endif 1198 1199 void (*set_curr_task) (struct rq *rq); 1200 void (*task_tick) (struct rq *rq, struct task_struct *p, int queued); 1201 void (*task_fork) (struct task_struct *p); 1202 void (*task_dead) (struct task_struct *p); 1203 1204 /* 1205 * The switched_from() call is allowed to drop rq->lock, therefore we 1206 * cannot assume the switched_from/switched_to pair is serliazed by 1207 * rq->lock. They are however serialized by p->pi_lock. 1208 */ 1209 void (*switched_from) (struct rq *this_rq, struct task_struct *task); 1210 void (*switched_to) (struct rq *this_rq, struct task_struct *task); 1211 void (*prio_changed) (struct rq *this_rq, struct task_struct *task, 1212 int oldprio); 1213 1214 unsigned int (*get_rr_interval) (struct rq *rq, 1215 struct task_struct *task); 1216 1217 void (*update_curr) (struct rq *rq); 1218 1219 #ifdef CONFIG_FAIR_GROUP_SCHED 1220 void (*task_move_group) (struct task_struct *p, int on_rq); 1221 #endif 1222 }; 1223 1224 static inline void put_prev_task(struct rq *rq, struct task_struct *prev) 1225 { 1226 prev->sched_class->put_prev_task(rq, prev); 1227 } 1228 1229 #define sched_class_highest (&stop_sched_class) 1230 #define for_each_class(class) \ 1231 for (class = sched_class_highest; class; class = class->next) 1232 1233 extern const struct sched_class stop_sched_class; 1234 extern const struct sched_class dl_sched_class; 1235 extern const struct sched_class rt_sched_class; 1236 extern const struct sched_class fair_sched_class; 1237 extern const struct sched_class idle_sched_class; 1238 1239 1240 #ifdef CONFIG_SMP 1241 1242 extern void update_group_capacity(struct sched_domain *sd, int cpu); 1243 1244 extern void trigger_load_balance(struct rq *rq); 1245 1246 extern void idle_enter_fair(struct rq *this_rq); 1247 extern void idle_exit_fair(struct rq *this_rq); 1248 1249 #else 1250 1251 static inline void idle_enter_fair(struct rq *rq) { } 1252 static inline void idle_exit_fair(struct rq *rq) { } 1253 1254 #endif 1255 1256 #ifdef CONFIG_CPU_IDLE 1257 static inline void idle_set_state(struct rq *rq, 1258 struct cpuidle_state *idle_state) 1259 { 1260 rq->idle_state = idle_state; 1261 } 1262 1263 static inline struct cpuidle_state *idle_get_state(struct rq *rq) 1264 { 1265 WARN_ON(!rcu_read_lock_held()); 1266 return rq->idle_state; 1267 } 1268 #else 1269 static inline void idle_set_state(struct rq *rq, 1270 struct cpuidle_state *idle_state) 1271 { 1272 } 1273 1274 static inline struct cpuidle_state *idle_get_state(struct rq *rq) 1275 { 1276 return NULL; 1277 } 1278 #endif 1279 1280 extern void sysrq_sched_debug_show(void); 1281 extern void sched_init_granularity(void); 1282 extern void update_max_interval(void); 1283 1284 extern void init_sched_dl_class(void); 1285 extern void init_sched_rt_class(void); 1286 extern void init_sched_fair_class(void); 1287 extern void init_sched_dl_class(void); 1288 1289 extern void resched_curr(struct rq *rq); 1290 extern void resched_cpu(int cpu); 1291 1292 extern struct rt_bandwidth def_rt_bandwidth; 1293 extern void init_rt_bandwidth(struct rt_bandwidth *rt_b, u64 period, u64 runtime); 1294 1295 extern struct dl_bandwidth def_dl_bandwidth; 1296 extern void init_dl_bandwidth(struct dl_bandwidth *dl_b, u64 period, u64 runtime); 1297 extern void init_dl_task_timer(struct sched_dl_entity *dl_se); 1298 1299 unsigned long to_ratio(u64 period, u64 runtime); 1300 1301 extern void update_idle_cpu_load(struct rq *this_rq); 1302 1303 extern void init_task_runnable_average(struct task_struct *p); 1304 1305 static inline void add_nr_running(struct rq *rq, unsigned count) 1306 { 1307 unsigned prev_nr = rq->nr_running; 1308 1309 rq->nr_running = prev_nr + count; 1310 1311 if (prev_nr < 2 && rq->nr_running >= 2) { 1312 #ifdef CONFIG_SMP 1313 if (!rq->rd->overload) 1314 rq->rd->overload = true; 1315 #endif 1316 1317 #ifdef CONFIG_NO_HZ_FULL 1318 if (tick_nohz_full_cpu(rq->cpu)) { 1319 /* 1320 * Tick is needed if more than one task runs on a CPU. 1321 * Send the target an IPI to kick it out of nohz mode. 1322 * 1323 * We assume that IPI implies full memory barrier and the 1324 * new value of rq->nr_running is visible on reception 1325 * from the target. 1326 */ 1327 tick_nohz_full_kick_cpu(rq->cpu); 1328 } 1329 #endif 1330 } 1331 } 1332 1333 static inline void sub_nr_running(struct rq *rq, unsigned count) 1334 { 1335 rq->nr_running -= count; 1336 } 1337 1338 static inline void rq_last_tick_reset(struct rq *rq) 1339 { 1340 #ifdef CONFIG_NO_HZ_FULL 1341 rq->last_sched_tick = jiffies; 1342 #endif 1343 } 1344 1345 extern void update_rq_clock(struct rq *rq); 1346 1347 extern void activate_task(struct rq *rq, struct task_struct *p, int flags); 1348 extern void deactivate_task(struct rq *rq, struct task_struct *p, int flags); 1349 1350 extern void check_preempt_curr(struct rq *rq, struct task_struct *p, int flags); 1351 1352 extern const_debug unsigned int sysctl_sched_time_avg; 1353 extern const_debug unsigned int sysctl_sched_nr_migrate; 1354 extern const_debug unsigned int sysctl_sched_migration_cost; 1355 1356 static inline u64 sched_avg_period(void) 1357 { 1358 return (u64)sysctl_sched_time_avg * NSEC_PER_MSEC / 2; 1359 } 1360 1361 #ifdef CONFIG_SCHED_HRTICK 1362 1363 /* 1364 * Use hrtick when: 1365 * - enabled by features 1366 * - hrtimer is actually high res 1367 */ 1368 static inline int hrtick_enabled(struct rq *rq) 1369 { 1370 if (!sched_feat(HRTICK)) 1371 return 0; 1372 if (!cpu_active(cpu_of(rq))) 1373 return 0; 1374 return hrtimer_is_hres_active(&rq->hrtick_timer); 1375 } 1376 1377 void hrtick_start(struct rq *rq, u64 delay); 1378 1379 #else 1380 1381 static inline int hrtick_enabled(struct rq *rq) 1382 { 1383 return 0; 1384 } 1385 1386 #endif /* CONFIG_SCHED_HRTICK */ 1387 1388 #ifdef CONFIG_SMP 1389 extern void sched_avg_update(struct rq *rq); 1390 1391 #ifndef arch_scale_freq_capacity 1392 static __always_inline 1393 unsigned long arch_scale_freq_capacity(struct sched_domain *sd, int cpu) 1394 { 1395 return SCHED_CAPACITY_SCALE; 1396 } 1397 #endif 1398 1399 static inline void sched_rt_avg_update(struct rq *rq, u64 rt_delta) 1400 { 1401 rq->rt_avg += rt_delta * arch_scale_freq_capacity(NULL, cpu_of(rq)); 1402 sched_avg_update(rq); 1403 } 1404 #else 1405 static inline void sched_rt_avg_update(struct rq *rq, u64 rt_delta) { } 1406 static inline void sched_avg_update(struct rq *rq) { } 1407 #endif 1408 1409 extern void start_bandwidth_timer(struct hrtimer *period_timer, ktime_t period); 1410 1411 /* 1412 * __task_rq_lock - lock the rq @p resides on. 1413 */ 1414 static inline struct rq *__task_rq_lock(struct task_struct *p) 1415 __acquires(rq->lock) 1416 { 1417 struct rq *rq; 1418 1419 lockdep_assert_held(&p->pi_lock); 1420 1421 for (;;) { 1422 rq = task_rq(p); 1423 raw_spin_lock(&rq->lock); 1424 if (likely(rq == task_rq(p) && !task_on_rq_migrating(p))) 1425 return rq; 1426 raw_spin_unlock(&rq->lock); 1427 1428 while (unlikely(task_on_rq_migrating(p))) 1429 cpu_relax(); 1430 } 1431 } 1432 1433 /* 1434 * task_rq_lock - lock p->pi_lock and lock the rq @p resides on. 1435 */ 1436 static inline struct rq *task_rq_lock(struct task_struct *p, unsigned long *flags) 1437 __acquires(p->pi_lock) 1438 __acquires(rq->lock) 1439 { 1440 struct rq *rq; 1441 1442 for (;;) { 1443 raw_spin_lock_irqsave(&p->pi_lock, *flags); 1444 rq = task_rq(p); 1445 raw_spin_lock(&rq->lock); 1446 /* 1447 * move_queued_task() task_rq_lock() 1448 * 1449 * ACQUIRE (rq->lock) 1450 * [S] ->on_rq = MIGRATING [L] rq = task_rq() 1451 * WMB (__set_task_cpu()) ACQUIRE (rq->lock); 1452 * [S] ->cpu = new_cpu [L] task_rq() 1453 * [L] ->on_rq 1454 * RELEASE (rq->lock) 1455 * 1456 * If we observe the old cpu in task_rq_lock, the acquire of 1457 * the old rq->lock will fully serialize against the stores. 1458 * 1459 * If we observe the new cpu in task_rq_lock, the acquire will 1460 * pair with the WMB to ensure we must then also see migrating. 1461 */ 1462 if (likely(rq == task_rq(p) && !task_on_rq_migrating(p))) 1463 return rq; 1464 raw_spin_unlock(&rq->lock); 1465 raw_spin_unlock_irqrestore(&p->pi_lock, *flags); 1466 1467 while (unlikely(task_on_rq_migrating(p))) 1468 cpu_relax(); 1469 } 1470 } 1471 1472 static inline void __task_rq_unlock(struct rq *rq) 1473 __releases(rq->lock) 1474 { 1475 raw_spin_unlock(&rq->lock); 1476 } 1477 1478 static inline void 1479 task_rq_unlock(struct rq *rq, struct task_struct *p, unsigned long *flags) 1480 __releases(rq->lock) 1481 __releases(p->pi_lock) 1482 { 1483 raw_spin_unlock(&rq->lock); 1484 raw_spin_unlock_irqrestore(&p->pi_lock, *flags); 1485 } 1486 1487 #ifdef CONFIG_SMP 1488 #ifdef CONFIG_PREEMPT 1489 1490 static inline void double_rq_lock(struct rq *rq1, struct rq *rq2); 1491 1492 /* 1493 * fair double_lock_balance: Safely acquires both rq->locks in a fair 1494 * way at the expense of forcing extra atomic operations in all 1495 * invocations. This assures that the double_lock is acquired using the 1496 * same underlying policy as the spinlock_t on this architecture, which 1497 * reduces latency compared to the unfair variant below. However, it 1498 * also adds more overhead and therefore may reduce throughput. 1499 */ 1500 static inline int _double_lock_balance(struct rq *this_rq, struct rq *busiest) 1501 __releases(this_rq->lock) 1502 __acquires(busiest->lock) 1503 __acquires(this_rq->lock) 1504 { 1505 raw_spin_unlock(&this_rq->lock); 1506 double_rq_lock(this_rq, busiest); 1507 1508 return 1; 1509 } 1510 1511 #else 1512 /* 1513 * Unfair double_lock_balance: Optimizes throughput at the expense of 1514 * latency by eliminating extra atomic operations when the locks are 1515 * already in proper order on entry. This favors lower cpu-ids and will 1516 * grant the double lock to lower cpus over higher ids under contention, 1517 * regardless of entry order into the function. 1518 */ 1519 static inline int _double_lock_balance(struct rq *this_rq, struct rq *busiest) 1520 __releases(this_rq->lock) 1521 __acquires(busiest->lock) 1522 __acquires(this_rq->lock) 1523 { 1524 int ret = 0; 1525 1526 if (unlikely(!raw_spin_trylock(&busiest->lock))) { 1527 if (busiest < this_rq) { 1528 raw_spin_unlock(&this_rq->lock); 1529 raw_spin_lock(&busiest->lock); 1530 raw_spin_lock_nested(&this_rq->lock, 1531 SINGLE_DEPTH_NESTING); 1532 ret = 1; 1533 } else 1534 raw_spin_lock_nested(&busiest->lock, 1535 SINGLE_DEPTH_NESTING); 1536 } 1537 return ret; 1538 } 1539 1540 #endif /* CONFIG_PREEMPT */ 1541 1542 /* 1543 * double_lock_balance - lock the busiest runqueue, this_rq is locked already. 1544 */ 1545 static inline int double_lock_balance(struct rq *this_rq, struct rq *busiest) 1546 { 1547 if (unlikely(!irqs_disabled())) { 1548 /* printk() doesn't work good under rq->lock */ 1549 raw_spin_unlock(&this_rq->lock); 1550 BUG_ON(1); 1551 } 1552 1553 return _double_lock_balance(this_rq, busiest); 1554 } 1555 1556 static inline void double_unlock_balance(struct rq *this_rq, struct rq *busiest) 1557 __releases(busiest->lock) 1558 { 1559 raw_spin_unlock(&busiest->lock); 1560 lock_set_subclass(&this_rq->lock.dep_map, 0, _RET_IP_); 1561 } 1562 1563 static inline void double_lock(spinlock_t *l1, spinlock_t *l2) 1564 { 1565 if (l1 > l2) 1566 swap(l1, l2); 1567 1568 spin_lock(l1); 1569 spin_lock_nested(l2, SINGLE_DEPTH_NESTING); 1570 } 1571 1572 static inline void double_lock_irq(spinlock_t *l1, spinlock_t *l2) 1573 { 1574 if (l1 > l2) 1575 swap(l1, l2); 1576 1577 spin_lock_irq(l1); 1578 spin_lock_nested(l2, SINGLE_DEPTH_NESTING); 1579 } 1580 1581 static inline void double_raw_lock(raw_spinlock_t *l1, raw_spinlock_t *l2) 1582 { 1583 if (l1 > l2) 1584 swap(l1, l2); 1585 1586 raw_spin_lock(l1); 1587 raw_spin_lock_nested(l2, SINGLE_DEPTH_NESTING); 1588 } 1589 1590 /* 1591 * double_rq_lock - safely lock two runqueues 1592 * 1593 * Note this does not disable interrupts like task_rq_lock, 1594 * you need to do so manually before calling. 1595 */ 1596 static inline void double_rq_lock(struct rq *rq1, struct rq *rq2) 1597 __acquires(rq1->lock) 1598 __acquires(rq2->lock) 1599 { 1600 BUG_ON(!irqs_disabled()); 1601 if (rq1 == rq2) { 1602 raw_spin_lock(&rq1->lock); 1603 __acquire(rq2->lock); /* Fake it out ;) */ 1604 } else { 1605 if (rq1 < rq2) { 1606 raw_spin_lock(&rq1->lock); 1607 raw_spin_lock_nested(&rq2->lock, SINGLE_DEPTH_NESTING); 1608 } else { 1609 raw_spin_lock(&rq2->lock); 1610 raw_spin_lock_nested(&rq1->lock, SINGLE_DEPTH_NESTING); 1611 } 1612 } 1613 } 1614 1615 /* 1616 * double_rq_unlock - safely unlock two runqueues 1617 * 1618 * Note this does not restore interrupts like task_rq_unlock, 1619 * you need to do so manually after calling. 1620 */ 1621 static inline void double_rq_unlock(struct rq *rq1, struct rq *rq2) 1622 __releases(rq1->lock) 1623 __releases(rq2->lock) 1624 { 1625 raw_spin_unlock(&rq1->lock); 1626 if (rq1 != rq2) 1627 raw_spin_unlock(&rq2->lock); 1628 else 1629 __release(rq2->lock); 1630 } 1631 1632 #else /* CONFIG_SMP */ 1633 1634 /* 1635 * double_rq_lock - safely lock two runqueues 1636 * 1637 * Note this does not disable interrupts like task_rq_lock, 1638 * you need to do so manually before calling. 1639 */ 1640 static inline void double_rq_lock(struct rq *rq1, struct rq *rq2) 1641 __acquires(rq1->lock) 1642 __acquires(rq2->lock) 1643 { 1644 BUG_ON(!irqs_disabled()); 1645 BUG_ON(rq1 != rq2); 1646 raw_spin_lock(&rq1->lock); 1647 __acquire(rq2->lock); /* Fake it out ;) */ 1648 } 1649 1650 /* 1651 * double_rq_unlock - safely unlock two runqueues 1652 * 1653 * Note this does not restore interrupts like task_rq_unlock, 1654 * you need to do so manually after calling. 1655 */ 1656 static inline void double_rq_unlock(struct rq *rq1, struct rq *rq2) 1657 __releases(rq1->lock) 1658 __releases(rq2->lock) 1659 { 1660 BUG_ON(rq1 != rq2); 1661 raw_spin_unlock(&rq1->lock); 1662 __release(rq2->lock); 1663 } 1664 1665 #endif 1666 1667 extern struct sched_entity *__pick_first_entity(struct cfs_rq *cfs_rq); 1668 extern struct sched_entity *__pick_last_entity(struct cfs_rq *cfs_rq); 1669 extern void print_cfs_stats(struct seq_file *m, int cpu); 1670 extern void print_rt_stats(struct seq_file *m, int cpu); 1671 extern void print_dl_stats(struct seq_file *m, int cpu); 1672 1673 extern void init_cfs_rq(struct cfs_rq *cfs_rq); 1674 extern void init_rt_rq(struct rt_rq *rt_rq); 1675 extern void init_dl_rq(struct dl_rq *dl_rq); 1676 1677 extern void cfs_bandwidth_usage_inc(void); 1678 extern void cfs_bandwidth_usage_dec(void); 1679 1680 #ifdef CONFIG_NO_HZ_COMMON 1681 enum rq_nohz_flag_bits { 1682 NOHZ_TICK_STOPPED, 1683 NOHZ_BALANCE_KICK, 1684 }; 1685 1686 #define nohz_flags(cpu) (&cpu_rq(cpu)->nohz_flags) 1687 #endif 1688 1689 #ifdef CONFIG_IRQ_TIME_ACCOUNTING 1690 1691 DECLARE_PER_CPU(u64, cpu_hardirq_time); 1692 DECLARE_PER_CPU(u64, cpu_softirq_time); 1693 1694 #ifndef CONFIG_64BIT 1695 DECLARE_PER_CPU(seqcount_t, irq_time_seq); 1696 1697 static inline void irq_time_write_begin(void) 1698 { 1699 __this_cpu_inc(irq_time_seq.sequence); 1700 smp_wmb(); 1701 } 1702 1703 static inline void irq_time_write_end(void) 1704 { 1705 smp_wmb(); 1706 __this_cpu_inc(irq_time_seq.sequence); 1707 } 1708 1709 static inline u64 irq_time_read(int cpu) 1710 { 1711 u64 irq_time; 1712 unsigned seq; 1713 1714 do { 1715 seq = read_seqcount_begin(&per_cpu(irq_time_seq, cpu)); 1716 irq_time = per_cpu(cpu_softirq_time, cpu) + 1717 per_cpu(cpu_hardirq_time, cpu); 1718 } while (read_seqcount_retry(&per_cpu(irq_time_seq, cpu), seq)); 1719 1720 return irq_time; 1721 } 1722 #else /* CONFIG_64BIT */ 1723 static inline void irq_time_write_begin(void) 1724 { 1725 } 1726 1727 static inline void irq_time_write_end(void) 1728 { 1729 } 1730 1731 static inline u64 irq_time_read(int cpu) 1732 { 1733 return per_cpu(cpu_softirq_time, cpu) + per_cpu(cpu_hardirq_time, cpu); 1734 } 1735 #endif /* CONFIG_64BIT */ 1736 #endif /* CONFIG_IRQ_TIME_ACCOUNTING */ 1737