1 2 #include <linux/sched.h> 3 #include <linux/sched/sysctl.h> 4 #include <linux/sched/rt.h> 5 #include <linux/sched/deadline.h> 6 #include <linux/mutex.h> 7 #include <linux/spinlock.h> 8 #include <linux/stop_machine.h> 9 #include <linux/irq_work.h> 10 #include <linux/tick.h> 11 #include <linux/slab.h> 12 13 #include "cpupri.h" 14 #include "cpudeadline.h" 15 #include "cpuacct.h" 16 17 struct rq; 18 struct cpuidle_state; 19 20 /* task_struct::on_rq states: */ 21 #define TASK_ON_RQ_QUEUED 1 22 #define TASK_ON_RQ_MIGRATING 2 23 24 extern __read_mostly int scheduler_running; 25 26 extern unsigned long calc_load_update; 27 extern atomic_long_t calc_load_tasks; 28 29 extern void calc_global_load_tick(struct rq *this_rq); 30 extern long calc_load_fold_active(struct rq *this_rq); 31 32 #ifdef CONFIG_SMP 33 extern void update_cpu_load_active(struct rq *this_rq); 34 #else 35 static inline void update_cpu_load_active(struct rq *this_rq) { } 36 #endif 37 38 /* 39 * Helpers for converting nanosecond timing to jiffy resolution 40 */ 41 #define NS_TO_JIFFIES(TIME) ((unsigned long)(TIME) / (NSEC_PER_SEC / HZ)) 42 43 /* 44 * Increase resolution of nice-level calculations for 64-bit architectures. 45 * The extra resolution improves shares distribution and load balancing of 46 * low-weight task groups (eg. nice +19 on an autogroup), deeper taskgroup 47 * hierarchies, especially on larger systems. This is not a user-visible change 48 * and does not change the user-interface for setting shares/weights. 49 * 50 * We increase resolution only if we have enough bits to allow this increased 51 * resolution (i.e. BITS_PER_LONG > 32). The costs for increasing resolution 52 * when BITS_PER_LONG <= 32 are pretty high and the returns do not justify the 53 * increased costs. 54 */ 55 #if 0 /* BITS_PER_LONG > 32 -- currently broken: it increases power usage under light load */ 56 # define SCHED_LOAD_RESOLUTION 10 57 # define scale_load(w) ((w) << SCHED_LOAD_RESOLUTION) 58 # define scale_load_down(w) ((w) >> SCHED_LOAD_RESOLUTION) 59 #else 60 # define SCHED_LOAD_RESOLUTION 0 61 # define scale_load(w) (w) 62 # define scale_load_down(w) (w) 63 #endif 64 65 #define SCHED_LOAD_SHIFT (10 + SCHED_LOAD_RESOLUTION) 66 #define SCHED_LOAD_SCALE (1L << SCHED_LOAD_SHIFT) 67 68 #define NICE_0_LOAD SCHED_LOAD_SCALE 69 #define NICE_0_SHIFT SCHED_LOAD_SHIFT 70 71 /* 72 * Single value that decides SCHED_DEADLINE internal math precision. 73 * 10 -> just above 1us 74 * 9 -> just above 0.5us 75 */ 76 #define DL_SCALE (10) 77 78 /* 79 * These are the 'tuning knobs' of the scheduler: 80 */ 81 82 /* 83 * single value that denotes runtime == period, ie unlimited time. 84 */ 85 #define RUNTIME_INF ((u64)~0ULL) 86 87 static inline int idle_policy(int policy) 88 { 89 return policy == SCHED_IDLE; 90 } 91 static inline int fair_policy(int policy) 92 { 93 return policy == SCHED_NORMAL || policy == SCHED_BATCH; 94 } 95 96 static inline int rt_policy(int policy) 97 { 98 return policy == SCHED_FIFO || policy == SCHED_RR; 99 } 100 101 static inline int dl_policy(int policy) 102 { 103 return policy == SCHED_DEADLINE; 104 } 105 static inline bool valid_policy(int policy) 106 { 107 return idle_policy(policy) || fair_policy(policy) || 108 rt_policy(policy) || dl_policy(policy); 109 } 110 111 static inline int task_has_rt_policy(struct task_struct *p) 112 { 113 return rt_policy(p->policy); 114 } 115 116 static inline int task_has_dl_policy(struct task_struct *p) 117 { 118 return dl_policy(p->policy); 119 } 120 121 /* 122 * Tells if entity @a should preempt entity @b. 123 */ 124 static inline bool 125 dl_entity_preempt(struct sched_dl_entity *a, struct sched_dl_entity *b) 126 { 127 return dl_time_before(a->deadline, b->deadline); 128 } 129 130 /* 131 * This is the priority-queue data structure of the RT scheduling class: 132 */ 133 struct rt_prio_array { 134 DECLARE_BITMAP(bitmap, MAX_RT_PRIO+1); /* include 1 bit for delimiter */ 135 struct list_head queue[MAX_RT_PRIO]; 136 }; 137 138 struct rt_bandwidth { 139 /* nests inside the rq lock: */ 140 raw_spinlock_t rt_runtime_lock; 141 ktime_t rt_period; 142 u64 rt_runtime; 143 struct hrtimer rt_period_timer; 144 unsigned int rt_period_active; 145 }; 146 147 void __dl_clear_params(struct task_struct *p); 148 149 /* 150 * To keep the bandwidth of -deadline tasks and groups under control 151 * we need some place where: 152 * - store the maximum -deadline bandwidth of the system (the group); 153 * - cache the fraction of that bandwidth that is currently allocated. 154 * 155 * This is all done in the data structure below. It is similar to the 156 * one used for RT-throttling (rt_bandwidth), with the main difference 157 * that, since here we are only interested in admission control, we 158 * do not decrease any runtime while the group "executes", neither we 159 * need a timer to replenish it. 160 * 161 * With respect to SMP, the bandwidth is given on a per-CPU basis, 162 * meaning that: 163 * - dl_bw (< 100%) is the bandwidth of the system (group) on each CPU; 164 * - dl_total_bw array contains, in the i-eth element, the currently 165 * allocated bandwidth on the i-eth CPU. 166 * Moreover, groups consume bandwidth on each CPU, while tasks only 167 * consume bandwidth on the CPU they're running on. 168 * Finally, dl_total_bw_cpu is used to cache the index of dl_total_bw 169 * that will be shown the next time the proc or cgroup controls will 170 * be red. It on its turn can be changed by writing on its own 171 * control. 172 */ 173 struct dl_bandwidth { 174 raw_spinlock_t dl_runtime_lock; 175 u64 dl_runtime; 176 u64 dl_period; 177 }; 178 179 static inline int dl_bandwidth_enabled(void) 180 { 181 return sysctl_sched_rt_runtime >= 0; 182 } 183 184 extern struct dl_bw *dl_bw_of(int i); 185 186 struct dl_bw { 187 raw_spinlock_t lock; 188 u64 bw, total_bw; 189 }; 190 191 static inline 192 void __dl_clear(struct dl_bw *dl_b, u64 tsk_bw) 193 { 194 dl_b->total_bw -= tsk_bw; 195 } 196 197 static inline 198 void __dl_add(struct dl_bw *dl_b, u64 tsk_bw) 199 { 200 dl_b->total_bw += tsk_bw; 201 } 202 203 static inline 204 bool __dl_overflow(struct dl_bw *dl_b, int cpus, u64 old_bw, u64 new_bw) 205 { 206 return dl_b->bw != -1 && 207 dl_b->bw * cpus < dl_b->total_bw - old_bw + new_bw; 208 } 209 210 extern struct mutex sched_domains_mutex; 211 212 #ifdef CONFIG_CGROUP_SCHED 213 214 #include <linux/cgroup.h> 215 216 struct cfs_rq; 217 struct rt_rq; 218 219 extern struct list_head task_groups; 220 221 struct cfs_bandwidth { 222 #ifdef CONFIG_CFS_BANDWIDTH 223 raw_spinlock_t lock; 224 ktime_t period; 225 u64 quota, runtime; 226 s64 hierarchical_quota; 227 u64 runtime_expires; 228 229 int idle, period_active; 230 struct hrtimer period_timer, slack_timer; 231 struct list_head throttled_cfs_rq; 232 233 /* statistics */ 234 int nr_periods, nr_throttled; 235 u64 throttled_time; 236 #endif 237 }; 238 239 /* task group related information */ 240 struct task_group { 241 struct cgroup_subsys_state css; 242 243 #ifdef CONFIG_FAIR_GROUP_SCHED 244 /* schedulable entities of this group on each cpu */ 245 struct sched_entity **se; 246 /* runqueue "owned" by this group on each cpu */ 247 struct cfs_rq **cfs_rq; 248 unsigned long shares; 249 250 #ifdef CONFIG_SMP 251 atomic_long_t load_avg; 252 #endif 253 #endif 254 255 #ifdef CONFIG_RT_GROUP_SCHED 256 struct sched_rt_entity **rt_se; 257 struct rt_rq **rt_rq; 258 259 struct rt_bandwidth rt_bandwidth; 260 #endif 261 262 struct rcu_head rcu; 263 struct list_head list; 264 265 struct task_group *parent; 266 struct list_head siblings; 267 struct list_head children; 268 269 #ifdef CONFIG_SCHED_AUTOGROUP 270 struct autogroup *autogroup; 271 #endif 272 273 struct cfs_bandwidth cfs_bandwidth; 274 }; 275 276 #ifdef CONFIG_FAIR_GROUP_SCHED 277 #define ROOT_TASK_GROUP_LOAD NICE_0_LOAD 278 279 /* 280 * A weight of 0 or 1 can cause arithmetics problems. 281 * A weight of a cfs_rq is the sum of weights of which entities 282 * are queued on this cfs_rq, so a weight of a entity should not be 283 * too large, so as the shares value of a task group. 284 * (The default weight is 1024 - so there's no practical 285 * limitation from this.) 286 */ 287 #define MIN_SHARES (1UL << 1) 288 #define MAX_SHARES (1UL << 18) 289 #endif 290 291 typedef int (*tg_visitor)(struct task_group *, void *); 292 293 extern int walk_tg_tree_from(struct task_group *from, 294 tg_visitor down, tg_visitor up, void *data); 295 296 /* 297 * Iterate the full tree, calling @down when first entering a node and @up when 298 * leaving it for the final time. 299 * 300 * Caller must hold rcu_lock or sufficient equivalent. 301 */ 302 static inline int walk_tg_tree(tg_visitor down, tg_visitor up, void *data) 303 { 304 return walk_tg_tree_from(&root_task_group, down, up, data); 305 } 306 307 extern int tg_nop(struct task_group *tg, void *data); 308 309 extern void free_fair_sched_group(struct task_group *tg); 310 extern int alloc_fair_sched_group(struct task_group *tg, struct task_group *parent); 311 extern void unregister_fair_sched_group(struct task_group *tg, int cpu); 312 extern void init_tg_cfs_entry(struct task_group *tg, struct cfs_rq *cfs_rq, 313 struct sched_entity *se, int cpu, 314 struct sched_entity *parent); 315 extern void init_cfs_bandwidth(struct cfs_bandwidth *cfs_b); 316 extern int sched_group_set_shares(struct task_group *tg, unsigned long shares); 317 318 extern void __refill_cfs_bandwidth_runtime(struct cfs_bandwidth *cfs_b); 319 extern void start_cfs_bandwidth(struct cfs_bandwidth *cfs_b); 320 extern void unthrottle_cfs_rq(struct cfs_rq *cfs_rq); 321 322 extern void free_rt_sched_group(struct task_group *tg); 323 extern int alloc_rt_sched_group(struct task_group *tg, struct task_group *parent); 324 extern void init_tg_rt_entry(struct task_group *tg, struct rt_rq *rt_rq, 325 struct sched_rt_entity *rt_se, int cpu, 326 struct sched_rt_entity *parent); 327 328 extern struct task_group *sched_create_group(struct task_group *parent); 329 extern void sched_online_group(struct task_group *tg, 330 struct task_group *parent); 331 extern void sched_destroy_group(struct task_group *tg); 332 extern void sched_offline_group(struct task_group *tg); 333 334 extern void sched_move_task(struct task_struct *tsk); 335 336 #ifdef CONFIG_FAIR_GROUP_SCHED 337 extern int sched_group_set_shares(struct task_group *tg, unsigned long shares); 338 #endif 339 340 #else /* CONFIG_CGROUP_SCHED */ 341 342 struct cfs_bandwidth { }; 343 344 #endif /* CONFIG_CGROUP_SCHED */ 345 346 /* CFS-related fields in a runqueue */ 347 struct cfs_rq { 348 struct load_weight load; 349 unsigned int nr_running, h_nr_running; 350 351 u64 exec_clock; 352 u64 min_vruntime; 353 #ifndef CONFIG_64BIT 354 u64 min_vruntime_copy; 355 #endif 356 357 struct rb_root tasks_timeline; 358 struct rb_node *rb_leftmost; 359 360 /* 361 * 'curr' points to currently running entity on this cfs_rq. 362 * It is set to NULL otherwise (i.e when none are currently running). 363 */ 364 struct sched_entity *curr, *next, *last, *skip; 365 366 #ifdef CONFIG_SCHED_DEBUG 367 unsigned int nr_spread_over; 368 #endif 369 370 #ifdef CONFIG_SMP 371 /* 372 * CFS load tracking 373 */ 374 struct sched_avg avg; 375 u64 runnable_load_sum; 376 unsigned long runnable_load_avg; 377 #ifdef CONFIG_FAIR_GROUP_SCHED 378 unsigned long tg_load_avg_contrib; 379 #endif 380 atomic_long_t removed_load_avg, removed_util_avg; 381 #ifndef CONFIG_64BIT 382 u64 load_last_update_time_copy; 383 #endif 384 385 #ifdef CONFIG_FAIR_GROUP_SCHED 386 /* 387 * h_load = weight * f(tg) 388 * 389 * Where f(tg) is the recursive weight fraction assigned to 390 * this group. 391 */ 392 unsigned long h_load; 393 u64 last_h_load_update; 394 struct sched_entity *h_load_next; 395 #endif /* CONFIG_FAIR_GROUP_SCHED */ 396 #endif /* CONFIG_SMP */ 397 398 #ifdef CONFIG_FAIR_GROUP_SCHED 399 struct rq *rq; /* cpu runqueue to which this cfs_rq is attached */ 400 401 /* 402 * leaf cfs_rqs are those that hold tasks (lowest schedulable entity in 403 * a hierarchy). Non-leaf lrqs hold other higher schedulable entities 404 * (like users, containers etc.) 405 * 406 * leaf_cfs_rq_list ties together list of leaf cfs_rq's in a cpu. This 407 * list is used during load balance. 408 */ 409 int on_list; 410 struct list_head leaf_cfs_rq_list; 411 struct task_group *tg; /* group that "owns" this runqueue */ 412 413 #ifdef CONFIG_CFS_BANDWIDTH 414 int runtime_enabled; 415 u64 runtime_expires; 416 s64 runtime_remaining; 417 418 u64 throttled_clock, throttled_clock_task; 419 u64 throttled_clock_task_time; 420 int throttled, throttle_count; 421 struct list_head throttled_list; 422 #endif /* CONFIG_CFS_BANDWIDTH */ 423 #endif /* CONFIG_FAIR_GROUP_SCHED */ 424 }; 425 426 static inline int rt_bandwidth_enabled(void) 427 { 428 return sysctl_sched_rt_runtime >= 0; 429 } 430 431 /* RT IPI pull logic requires IRQ_WORK */ 432 #ifdef CONFIG_IRQ_WORK 433 # define HAVE_RT_PUSH_IPI 434 #endif 435 436 /* Real-Time classes' related field in a runqueue: */ 437 struct rt_rq { 438 struct rt_prio_array active; 439 unsigned int rt_nr_running; 440 #if defined CONFIG_SMP || defined CONFIG_RT_GROUP_SCHED 441 struct { 442 int curr; /* highest queued rt task prio */ 443 #ifdef CONFIG_SMP 444 int next; /* next highest */ 445 #endif 446 } highest_prio; 447 #endif 448 #ifdef CONFIG_SMP 449 unsigned long rt_nr_migratory; 450 unsigned long rt_nr_total; 451 int overloaded; 452 struct plist_head pushable_tasks; 453 #ifdef HAVE_RT_PUSH_IPI 454 int push_flags; 455 int push_cpu; 456 struct irq_work push_work; 457 raw_spinlock_t push_lock; 458 #endif 459 #endif /* CONFIG_SMP */ 460 int rt_queued; 461 462 int rt_throttled; 463 u64 rt_time; 464 u64 rt_runtime; 465 /* Nests inside the rq lock: */ 466 raw_spinlock_t rt_runtime_lock; 467 468 #ifdef CONFIG_RT_GROUP_SCHED 469 unsigned long rt_nr_boosted; 470 471 struct rq *rq; 472 struct task_group *tg; 473 #endif 474 }; 475 476 /* Deadline class' related fields in a runqueue */ 477 struct dl_rq { 478 /* runqueue is an rbtree, ordered by deadline */ 479 struct rb_root rb_root; 480 struct rb_node *rb_leftmost; 481 482 unsigned long dl_nr_running; 483 484 #ifdef CONFIG_SMP 485 /* 486 * Deadline values of the currently executing and the 487 * earliest ready task on this rq. Caching these facilitates 488 * the decision wether or not a ready but not running task 489 * should migrate somewhere else. 490 */ 491 struct { 492 u64 curr; 493 u64 next; 494 } earliest_dl; 495 496 unsigned long dl_nr_migratory; 497 int overloaded; 498 499 /* 500 * Tasks on this rq that can be pushed away. They are kept in 501 * an rb-tree, ordered by tasks' deadlines, with caching 502 * of the leftmost (earliest deadline) element. 503 */ 504 struct rb_root pushable_dl_tasks_root; 505 struct rb_node *pushable_dl_tasks_leftmost; 506 #else 507 struct dl_bw dl_bw; 508 #endif 509 }; 510 511 #ifdef CONFIG_SMP 512 513 /* 514 * We add the notion of a root-domain which will be used to define per-domain 515 * variables. Each exclusive cpuset essentially defines an island domain by 516 * fully partitioning the member cpus from any other cpuset. Whenever a new 517 * exclusive cpuset is created, we also create and attach a new root-domain 518 * object. 519 * 520 */ 521 struct root_domain { 522 atomic_t refcount; 523 atomic_t rto_count; 524 struct rcu_head rcu; 525 cpumask_var_t span; 526 cpumask_var_t online; 527 528 /* Indicate more than one runnable task for any CPU */ 529 bool overload; 530 531 /* 532 * The bit corresponding to a CPU gets set here if such CPU has more 533 * than one runnable -deadline task (as it is below for RT tasks). 534 */ 535 cpumask_var_t dlo_mask; 536 atomic_t dlo_count; 537 struct dl_bw dl_bw; 538 struct cpudl cpudl; 539 540 /* 541 * The "RT overload" flag: it gets set if a CPU has more than 542 * one runnable RT task. 543 */ 544 cpumask_var_t rto_mask; 545 struct cpupri cpupri; 546 }; 547 548 extern struct root_domain def_root_domain; 549 550 #endif /* CONFIG_SMP */ 551 552 /* 553 * This is the main, per-CPU runqueue data structure. 554 * 555 * Locking rule: those places that want to lock multiple runqueues 556 * (such as the load balancing or the thread migration code), lock 557 * acquire operations must be ordered by ascending &runqueue. 558 */ 559 struct rq { 560 /* runqueue lock: */ 561 raw_spinlock_t lock; 562 563 /* 564 * nr_running and cpu_load should be in the same cacheline because 565 * remote CPUs use both these fields when doing load calculation. 566 */ 567 unsigned int nr_running; 568 #ifdef CONFIG_NUMA_BALANCING 569 unsigned int nr_numa_running; 570 unsigned int nr_preferred_running; 571 #endif 572 #define CPU_LOAD_IDX_MAX 5 573 unsigned long cpu_load[CPU_LOAD_IDX_MAX]; 574 unsigned long last_load_update_tick; 575 #ifdef CONFIG_NO_HZ_COMMON 576 u64 nohz_stamp; 577 unsigned long nohz_flags; 578 #endif 579 #ifdef CONFIG_NO_HZ_FULL 580 unsigned long last_sched_tick; 581 #endif 582 /* capture load from *all* tasks on this cpu: */ 583 struct load_weight load; 584 unsigned long nr_load_updates; 585 u64 nr_switches; 586 587 struct cfs_rq cfs; 588 struct rt_rq rt; 589 struct dl_rq dl; 590 591 #ifdef CONFIG_FAIR_GROUP_SCHED 592 /* list of leaf cfs_rq on this cpu: */ 593 struct list_head leaf_cfs_rq_list; 594 #endif /* CONFIG_FAIR_GROUP_SCHED */ 595 596 /* 597 * This is part of a global counter where only the total sum 598 * over all CPUs matters. A task can increase this counter on 599 * one CPU and if it got migrated afterwards it may decrease 600 * it on another CPU. Always updated under the runqueue lock: 601 */ 602 unsigned long nr_uninterruptible; 603 604 struct task_struct *curr, *idle, *stop; 605 unsigned long next_balance; 606 struct mm_struct *prev_mm; 607 608 unsigned int clock_skip_update; 609 u64 clock; 610 u64 clock_task; 611 612 atomic_t nr_iowait; 613 614 #ifdef CONFIG_SMP 615 struct root_domain *rd; 616 struct sched_domain *sd; 617 618 unsigned long cpu_capacity; 619 unsigned long cpu_capacity_orig; 620 621 struct callback_head *balance_callback; 622 623 unsigned char idle_balance; 624 /* For active balancing */ 625 int active_balance; 626 int push_cpu; 627 struct cpu_stop_work active_balance_work; 628 /* cpu of this runqueue: */ 629 int cpu; 630 int online; 631 632 struct list_head cfs_tasks; 633 634 u64 rt_avg; 635 u64 age_stamp; 636 u64 idle_stamp; 637 u64 avg_idle; 638 639 /* This is used to determine avg_idle's max value */ 640 u64 max_idle_balance_cost; 641 #endif 642 643 #ifdef CONFIG_IRQ_TIME_ACCOUNTING 644 u64 prev_irq_time; 645 #endif 646 #ifdef CONFIG_PARAVIRT 647 u64 prev_steal_time; 648 #endif 649 #ifdef CONFIG_PARAVIRT_TIME_ACCOUNTING 650 u64 prev_steal_time_rq; 651 #endif 652 653 /* calc_load related fields */ 654 unsigned long calc_load_update; 655 long calc_load_active; 656 657 #ifdef CONFIG_SCHED_HRTICK 658 #ifdef CONFIG_SMP 659 int hrtick_csd_pending; 660 struct call_single_data hrtick_csd; 661 #endif 662 struct hrtimer hrtick_timer; 663 #endif 664 665 #ifdef CONFIG_SCHEDSTATS 666 /* latency stats */ 667 struct sched_info rq_sched_info; 668 unsigned long long rq_cpu_time; 669 /* could above be rq->cfs_rq.exec_clock + rq->rt_rq.rt_runtime ? */ 670 671 /* sys_sched_yield() stats */ 672 unsigned int yld_count; 673 674 /* schedule() stats */ 675 unsigned int sched_count; 676 unsigned int sched_goidle; 677 678 /* try_to_wake_up() stats */ 679 unsigned int ttwu_count; 680 unsigned int ttwu_local; 681 #endif 682 683 #ifdef CONFIG_SMP 684 struct llist_head wake_list; 685 #endif 686 687 #ifdef CONFIG_CPU_IDLE 688 /* Must be inspected within a rcu lock section */ 689 struct cpuidle_state *idle_state; 690 #endif 691 }; 692 693 static inline int cpu_of(struct rq *rq) 694 { 695 #ifdef CONFIG_SMP 696 return rq->cpu; 697 #else 698 return 0; 699 #endif 700 } 701 702 DECLARE_PER_CPU_SHARED_ALIGNED(struct rq, runqueues); 703 704 #define cpu_rq(cpu) (&per_cpu(runqueues, (cpu))) 705 #define this_rq() this_cpu_ptr(&runqueues) 706 #define task_rq(p) cpu_rq(task_cpu(p)) 707 #define cpu_curr(cpu) (cpu_rq(cpu)->curr) 708 #define raw_rq() raw_cpu_ptr(&runqueues) 709 710 static inline u64 __rq_clock_broken(struct rq *rq) 711 { 712 return READ_ONCE(rq->clock); 713 } 714 715 static inline u64 rq_clock(struct rq *rq) 716 { 717 lockdep_assert_held(&rq->lock); 718 return rq->clock; 719 } 720 721 static inline u64 rq_clock_task(struct rq *rq) 722 { 723 lockdep_assert_held(&rq->lock); 724 return rq->clock_task; 725 } 726 727 #define RQCF_REQ_SKIP 0x01 728 #define RQCF_ACT_SKIP 0x02 729 730 static inline void rq_clock_skip_update(struct rq *rq, bool skip) 731 { 732 lockdep_assert_held(&rq->lock); 733 if (skip) 734 rq->clock_skip_update |= RQCF_REQ_SKIP; 735 else 736 rq->clock_skip_update &= ~RQCF_REQ_SKIP; 737 } 738 739 #ifdef CONFIG_NUMA 740 enum numa_topology_type { 741 NUMA_DIRECT, 742 NUMA_GLUELESS_MESH, 743 NUMA_BACKPLANE, 744 }; 745 extern enum numa_topology_type sched_numa_topology_type; 746 extern int sched_max_numa_distance; 747 extern bool find_numa_distance(int distance); 748 #endif 749 750 #ifdef CONFIG_NUMA_BALANCING 751 /* The regions in numa_faults array from task_struct */ 752 enum numa_faults_stats { 753 NUMA_MEM = 0, 754 NUMA_CPU, 755 NUMA_MEMBUF, 756 NUMA_CPUBUF 757 }; 758 extern void sched_setnuma(struct task_struct *p, int node); 759 extern int migrate_task_to(struct task_struct *p, int cpu); 760 extern int migrate_swap(struct task_struct *, struct task_struct *); 761 #endif /* CONFIG_NUMA_BALANCING */ 762 763 #ifdef CONFIG_SMP 764 765 static inline void 766 queue_balance_callback(struct rq *rq, 767 struct callback_head *head, 768 void (*func)(struct rq *rq)) 769 { 770 lockdep_assert_held(&rq->lock); 771 772 if (unlikely(head->next)) 773 return; 774 775 head->func = (void (*)(struct callback_head *))func; 776 head->next = rq->balance_callback; 777 rq->balance_callback = head; 778 } 779 780 extern void sched_ttwu_pending(void); 781 782 #define rcu_dereference_check_sched_domain(p) \ 783 rcu_dereference_check((p), \ 784 lockdep_is_held(&sched_domains_mutex)) 785 786 /* 787 * The domain tree (rq->sd) is protected by RCU's quiescent state transition. 788 * See detach_destroy_domains: synchronize_sched for details. 789 * 790 * The domain tree of any CPU may only be accessed from within 791 * preempt-disabled sections. 792 */ 793 #define for_each_domain(cpu, __sd) \ 794 for (__sd = rcu_dereference_check_sched_domain(cpu_rq(cpu)->sd); \ 795 __sd; __sd = __sd->parent) 796 797 #define for_each_lower_domain(sd) for (; sd; sd = sd->child) 798 799 /** 800 * highest_flag_domain - Return highest sched_domain containing flag. 801 * @cpu: The cpu whose highest level of sched domain is to 802 * be returned. 803 * @flag: The flag to check for the highest sched_domain 804 * for the given cpu. 805 * 806 * Returns the highest sched_domain of a cpu which contains the given flag. 807 */ 808 static inline struct sched_domain *highest_flag_domain(int cpu, int flag) 809 { 810 struct sched_domain *sd, *hsd = NULL; 811 812 for_each_domain(cpu, sd) { 813 if (!(sd->flags & flag)) 814 break; 815 hsd = sd; 816 } 817 818 return hsd; 819 } 820 821 static inline struct sched_domain *lowest_flag_domain(int cpu, int flag) 822 { 823 struct sched_domain *sd; 824 825 for_each_domain(cpu, sd) { 826 if (sd->flags & flag) 827 break; 828 } 829 830 return sd; 831 } 832 833 DECLARE_PER_CPU(struct sched_domain *, sd_llc); 834 DECLARE_PER_CPU(int, sd_llc_size); 835 DECLARE_PER_CPU(int, sd_llc_id); 836 DECLARE_PER_CPU(struct sched_domain *, sd_numa); 837 DECLARE_PER_CPU(struct sched_domain *, sd_busy); 838 DECLARE_PER_CPU(struct sched_domain *, sd_asym); 839 840 struct sched_group_capacity { 841 atomic_t ref; 842 /* 843 * CPU capacity of this group, SCHED_LOAD_SCALE being max capacity 844 * for a single CPU. 845 */ 846 unsigned int capacity; 847 unsigned long next_update; 848 int imbalance; /* XXX unrelated to capacity but shared group state */ 849 /* 850 * Number of busy cpus in this group. 851 */ 852 atomic_t nr_busy_cpus; 853 854 unsigned long cpumask[0]; /* iteration mask */ 855 }; 856 857 struct sched_group { 858 struct sched_group *next; /* Must be a circular list */ 859 atomic_t ref; 860 861 unsigned int group_weight; 862 struct sched_group_capacity *sgc; 863 864 /* 865 * The CPUs this group covers. 866 * 867 * NOTE: this field is variable length. (Allocated dynamically 868 * by attaching extra space to the end of the structure, 869 * depending on how many CPUs the kernel has booted up with) 870 */ 871 unsigned long cpumask[0]; 872 }; 873 874 static inline struct cpumask *sched_group_cpus(struct sched_group *sg) 875 { 876 return to_cpumask(sg->cpumask); 877 } 878 879 /* 880 * cpumask masking which cpus in the group are allowed to iterate up the domain 881 * tree. 882 */ 883 static inline struct cpumask *sched_group_mask(struct sched_group *sg) 884 { 885 return to_cpumask(sg->sgc->cpumask); 886 } 887 888 /** 889 * group_first_cpu - Returns the first cpu in the cpumask of a sched_group. 890 * @group: The group whose first cpu is to be returned. 891 */ 892 static inline unsigned int group_first_cpu(struct sched_group *group) 893 { 894 return cpumask_first(sched_group_cpus(group)); 895 } 896 897 extern int group_balance_cpu(struct sched_group *sg); 898 899 #else 900 901 static inline void sched_ttwu_pending(void) { } 902 903 #endif /* CONFIG_SMP */ 904 905 #include "stats.h" 906 #include "auto_group.h" 907 908 #ifdef CONFIG_CGROUP_SCHED 909 910 /* 911 * Return the group to which this tasks belongs. 912 * 913 * We cannot use task_css() and friends because the cgroup subsystem 914 * changes that value before the cgroup_subsys::attach() method is called, 915 * therefore we cannot pin it and might observe the wrong value. 916 * 917 * The same is true for autogroup's p->signal->autogroup->tg, the autogroup 918 * core changes this before calling sched_move_task(). 919 * 920 * Instead we use a 'copy' which is updated from sched_move_task() while 921 * holding both task_struct::pi_lock and rq::lock. 922 */ 923 static inline struct task_group *task_group(struct task_struct *p) 924 { 925 return p->sched_task_group; 926 } 927 928 /* Change a task's cfs_rq and parent entity if it moves across CPUs/groups */ 929 static inline void set_task_rq(struct task_struct *p, unsigned int cpu) 930 { 931 #if defined(CONFIG_FAIR_GROUP_SCHED) || defined(CONFIG_RT_GROUP_SCHED) 932 struct task_group *tg = task_group(p); 933 #endif 934 935 #ifdef CONFIG_FAIR_GROUP_SCHED 936 p->se.cfs_rq = tg->cfs_rq[cpu]; 937 p->se.parent = tg->se[cpu]; 938 #endif 939 940 #ifdef CONFIG_RT_GROUP_SCHED 941 p->rt.rt_rq = tg->rt_rq[cpu]; 942 p->rt.parent = tg->rt_se[cpu]; 943 #endif 944 } 945 946 #else /* CONFIG_CGROUP_SCHED */ 947 948 static inline void set_task_rq(struct task_struct *p, unsigned int cpu) { } 949 static inline struct task_group *task_group(struct task_struct *p) 950 { 951 return NULL; 952 } 953 954 #endif /* CONFIG_CGROUP_SCHED */ 955 956 static inline void __set_task_cpu(struct task_struct *p, unsigned int cpu) 957 { 958 set_task_rq(p, cpu); 959 #ifdef CONFIG_SMP 960 /* 961 * After ->cpu is set up to a new value, task_rq_lock(p, ...) can be 962 * successfuly executed on another CPU. We must ensure that updates of 963 * per-task data have been completed by this moment. 964 */ 965 smp_wmb(); 966 task_thread_info(p)->cpu = cpu; 967 p->wake_cpu = cpu; 968 #endif 969 } 970 971 /* 972 * Tunables that become constants when CONFIG_SCHED_DEBUG is off: 973 */ 974 #ifdef CONFIG_SCHED_DEBUG 975 # include <linux/static_key.h> 976 # define const_debug __read_mostly 977 #else 978 # define const_debug const 979 #endif 980 981 extern const_debug unsigned int sysctl_sched_features; 982 983 #define SCHED_FEAT(name, enabled) \ 984 __SCHED_FEAT_##name , 985 986 enum { 987 #include "features.h" 988 __SCHED_FEAT_NR, 989 }; 990 991 #undef SCHED_FEAT 992 993 #if defined(CONFIG_SCHED_DEBUG) && defined(HAVE_JUMP_LABEL) 994 #define SCHED_FEAT(name, enabled) \ 995 static __always_inline bool static_branch_##name(struct static_key *key) \ 996 { \ 997 return static_key_##enabled(key); \ 998 } 999 1000 #include "features.h" 1001 1002 #undef SCHED_FEAT 1003 1004 extern struct static_key sched_feat_keys[__SCHED_FEAT_NR]; 1005 #define sched_feat(x) (static_branch_##x(&sched_feat_keys[__SCHED_FEAT_##x])) 1006 #else /* !(SCHED_DEBUG && HAVE_JUMP_LABEL) */ 1007 #define sched_feat(x) (sysctl_sched_features & (1UL << __SCHED_FEAT_##x)) 1008 #endif /* SCHED_DEBUG && HAVE_JUMP_LABEL */ 1009 1010 extern struct static_key_false sched_numa_balancing; 1011 1012 static inline u64 global_rt_period(void) 1013 { 1014 return (u64)sysctl_sched_rt_period * NSEC_PER_USEC; 1015 } 1016 1017 static inline u64 global_rt_runtime(void) 1018 { 1019 if (sysctl_sched_rt_runtime < 0) 1020 return RUNTIME_INF; 1021 1022 return (u64)sysctl_sched_rt_runtime * NSEC_PER_USEC; 1023 } 1024 1025 static inline int task_current(struct rq *rq, struct task_struct *p) 1026 { 1027 return rq->curr == p; 1028 } 1029 1030 static inline int task_running(struct rq *rq, struct task_struct *p) 1031 { 1032 #ifdef CONFIG_SMP 1033 return p->on_cpu; 1034 #else 1035 return task_current(rq, p); 1036 #endif 1037 } 1038 1039 static inline int task_on_rq_queued(struct task_struct *p) 1040 { 1041 return p->on_rq == TASK_ON_RQ_QUEUED; 1042 } 1043 1044 static inline int task_on_rq_migrating(struct task_struct *p) 1045 { 1046 return p->on_rq == TASK_ON_RQ_MIGRATING; 1047 } 1048 1049 #ifndef prepare_arch_switch 1050 # define prepare_arch_switch(next) do { } while (0) 1051 #endif 1052 #ifndef finish_arch_post_lock_switch 1053 # define finish_arch_post_lock_switch() do { } while (0) 1054 #endif 1055 1056 static inline void prepare_lock_switch(struct rq *rq, struct task_struct *next) 1057 { 1058 #ifdef CONFIG_SMP 1059 /* 1060 * We can optimise this out completely for !SMP, because the 1061 * SMP rebalancing from interrupt is the only thing that cares 1062 * here. 1063 */ 1064 next->on_cpu = 1; 1065 #endif 1066 } 1067 1068 static inline void finish_lock_switch(struct rq *rq, struct task_struct *prev) 1069 { 1070 #ifdef CONFIG_SMP 1071 /* 1072 * After ->on_cpu is cleared, the task can be moved to a different CPU. 1073 * We must ensure this doesn't happen until the switch is completely 1074 * finished. 1075 * 1076 * Pairs with the control dependency and rmb in try_to_wake_up(). 1077 */ 1078 smp_store_release(&prev->on_cpu, 0); 1079 #endif 1080 #ifdef CONFIG_DEBUG_SPINLOCK 1081 /* this is a valid case when another task releases the spinlock */ 1082 rq->lock.owner = current; 1083 #endif 1084 /* 1085 * If we are tracking spinlock dependencies then we have to 1086 * fix up the runqueue lock - which gets 'carried over' from 1087 * prev into current: 1088 */ 1089 spin_acquire(&rq->lock.dep_map, 0, 0, _THIS_IP_); 1090 1091 raw_spin_unlock_irq(&rq->lock); 1092 } 1093 1094 /* 1095 * wake flags 1096 */ 1097 #define WF_SYNC 0x01 /* waker goes to sleep after wakeup */ 1098 #define WF_FORK 0x02 /* child wakeup after fork */ 1099 #define WF_MIGRATED 0x4 /* internal use, task got migrated */ 1100 1101 /* 1102 * To aid in avoiding the subversion of "niceness" due to uneven distribution 1103 * of tasks with abnormal "nice" values across CPUs the contribution that 1104 * each task makes to its run queue's load is weighted according to its 1105 * scheduling class and "nice" value. For SCHED_NORMAL tasks this is just a 1106 * scaled version of the new time slice allocation that they receive on time 1107 * slice expiry etc. 1108 */ 1109 1110 #define WEIGHT_IDLEPRIO 3 1111 #define WMULT_IDLEPRIO 1431655765 1112 1113 /* 1114 * Nice levels are multiplicative, with a gentle 10% change for every 1115 * nice level changed. I.e. when a CPU-bound task goes from nice 0 to 1116 * nice 1, it will get ~10% less CPU time than another CPU-bound task 1117 * that remained on nice 0. 1118 * 1119 * The "10% effect" is relative and cumulative: from _any_ nice level, 1120 * if you go up 1 level, it's -10% CPU usage, if you go down 1 level 1121 * it's +10% CPU usage. (to achieve that we use a multiplier of 1.25. 1122 * If a task goes up by ~10% and another task goes down by ~10% then 1123 * the relative distance between them is ~25%.) 1124 */ 1125 static const int prio_to_weight[40] = { 1126 /* -20 */ 88761, 71755, 56483, 46273, 36291, 1127 /* -15 */ 29154, 23254, 18705, 14949, 11916, 1128 /* -10 */ 9548, 7620, 6100, 4904, 3906, 1129 /* -5 */ 3121, 2501, 1991, 1586, 1277, 1130 /* 0 */ 1024, 820, 655, 526, 423, 1131 /* 5 */ 335, 272, 215, 172, 137, 1132 /* 10 */ 110, 87, 70, 56, 45, 1133 /* 15 */ 36, 29, 23, 18, 15, 1134 }; 1135 1136 /* 1137 * Inverse (2^32/x) values of the prio_to_weight[] array, precalculated. 1138 * 1139 * In cases where the weight does not change often, we can use the 1140 * precalculated inverse to speed up arithmetics by turning divisions 1141 * into multiplications: 1142 */ 1143 static const u32 prio_to_wmult[40] = { 1144 /* -20 */ 48388, 59856, 76040, 92818, 118348, 1145 /* -15 */ 147320, 184698, 229616, 287308, 360437, 1146 /* -10 */ 449829, 563644, 704093, 875809, 1099582, 1147 /* -5 */ 1376151, 1717300, 2157191, 2708050, 3363326, 1148 /* 0 */ 4194304, 5237765, 6557202, 8165337, 10153587, 1149 /* 5 */ 12820798, 15790321, 19976592, 24970740, 31350126, 1150 /* 10 */ 39045157, 49367440, 61356676, 76695844, 95443717, 1151 /* 15 */ 119304647, 148102320, 186737708, 238609294, 286331153, 1152 }; 1153 1154 #define ENQUEUE_WAKEUP 0x01 1155 #define ENQUEUE_HEAD 0x02 1156 #ifdef CONFIG_SMP 1157 #define ENQUEUE_WAKING 0x04 /* sched_class::task_waking was called */ 1158 #else 1159 #define ENQUEUE_WAKING 0x00 1160 #endif 1161 #define ENQUEUE_REPLENISH 0x08 1162 #define ENQUEUE_RESTORE 0x10 1163 1164 #define DEQUEUE_SLEEP 0x01 1165 #define DEQUEUE_SAVE 0x02 1166 1167 #define RETRY_TASK ((void *)-1UL) 1168 1169 struct sched_class { 1170 const struct sched_class *next; 1171 1172 void (*enqueue_task) (struct rq *rq, struct task_struct *p, int flags); 1173 void (*dequeue_task) (struct rq *rq, struct task_struct *p, int flags); 1174 void (*yield_task) (struct rq *rq); 1175 bool (*yield_to_task) (struct rq *rq, struct task_struct *p, bool preempt); 1176 1177 void (*check_preempt_curr) (struct rq *rq, struct task_struct *p, int flags); 1178 1179 /* 1180 * It is the responsibility of the pick_next_task() method that will 1181 * return the next task to call put_prev_task() on the @prev task or 1182 * something equivalent. 1183 * 1184 * May return RETRY_TASK when it finds a higher prio class has runnable 1185 * tasks. 1186 */ 1187 struct task_struct * (*pick_next_task) (struct rq *rq, 1188 struct task_struct *prev); 1189 void (*put_prev_task) (struct rq *rq, struct task_struct *p); 1190 1191 #ifdef CONFIG_SMP 1192 int (*select_task_rq)(struct task_struct *p, int task_cpu, int sd_flag, int flags); 1193 void (*migrate_task_rq)(struct task_struct *p); 1194 1195 void (*task_waking) (struct task_struct *task); 1196 void (*task_woken) (struct rq *this_rq, struct task_struct *task); 1197 1198 void (*set_cpus_allowed)(struct task_struct *p, 1199 const struct cpumask *newmask); 1200 1201 void (*rq_online)(struct rq *rq); 1202 void (*rq_offline)(struct rq *rq); 1203 #endif 1204 1205 void (*set_curr_task) (struct rq *rq); 1206 void (*task_tick) (struct rq *rq, struct task_struct *p, int queued); 1207 void (*task_fork) (struct task_struct *p); 1208 void (*task_dead) (struct task_struct *p); 1209 1210 /* 1211 * The switched_from() call is allowed to drop rq->lock, therefore we 1212 * cannot assume the switched_from/switched_to pair is serliazed by 1213 * rq->lock. They are however serialized by p->pi_lock. 1214 */ 1215 void (*switched_from) (struct rq *this_rq, struct task_struct *task); 1216 void (*switched_to) (struct rq *this_rq, struct task_struct *task); 1217 void (*prio_changed) (struct rq *this_rq, struct task_struct *task, 1218 int oldprio); 1219 1220 unsigned int (*get_rr_interval) (struct rq *rq, 1221 struct task_struct *task); 1222 1223 void (*update_curr) (struct rq *rq); 1224 1225 #ifdef CONFIG_FAIR_GROUP_SCHED 1226 void (*task_move_group) (struct task_struct *p); 1227 #endif 1228 }; 1229 1230 static inline void put_prev_task(struct rq *rq, struct task_struct *prev) 1231 { 1232 prev->sched_class->put_prev_task(rq, prev); 1233 } 1234 1235 #define sched_class_highest (&stop_sched_class) 1236 #define for_each_class(class) \ 1237 for (class = sched_class_highest; class; class = class->next) 1238 1239 extern const struct sched_class stop_sched_class; 1240 extern const struct sched_class dl_sched_class; 1241 extern const struct sched_class rt_sched_class; 1242 extern const struct sched_class fair_sched_class; 1243 extern const struct sched_class idle_sched_class; 1244 1245 1246 #ifdef CONFIG_SMP 1247 1248 extern void update_group_capacity(struct sched_domain *sd, int cpu); 1249 1250 extern void trigger_load_balance(struct rq *rq); 1251 1252 extern void idle_enter_fair(struct rq *this_rq); 1253 extern void idle_exit_fair(struct rq *this_rq); 1254 1255 extern void set_cpus_allowed_common(struct task_struct *p, const struct cpumask *new_mask); 1256 1257 #else 1258 1259 static inline void idle_enter_fair(struct rq *rq) { } 1260 static inline void idle_exit_fair(struct rq *rq) { } 1261 1262 #endif 1263 1264 #ifdef CONFIG_CPU_IDLE 1265 static inline void idle_set_state(struct rq *rq, 1266 struct cpuidle_state *idle_state) 1267 { 1268 rq->idle_state = idle_state; 1269 } 1270 1271 static inline struct cpuidle_state *idle_get_state(struct rq *rq) 1272 { 1273 WARN_ON(!rcu_read_lock_held()); 1274 return rq->idle_state; 1275 } 1276 #else 1277 static inline void idle_set_state(struct rq *rq, 1278 struct cpuidle_state *idle_state) 1279 { 1280 } 1281 1282 static inline struct cpuidle_state *idle_get_state(struct rq *rq) 1283 { 1284 return NULL; 1285 } 1286 #endif 1287 1288 extern void sysrq_sched_debug_show(void); 1289 extern void sched_init_granularity(void); 1290 extern void update_max_interval(void); 1291 1292 extern void init_sched_dl_class(void); 1293 extern void init_sched_rt_class(void); 1294 extern void init_sched_fair_class(void); 1295 1296 extern void resched_curr(struct rq *rq); 1297 extern void resched_cpu(int cpu); 1298 1299 extern struct rt_bandwidth def_rt_bandwidth; 1300 extern void init_rt_bandwidth(struct rt_bandwidth *rt_b, u64 period, u64 runtime); 1301 1302 extern struct dl_bandwidth def_dl_bandwidth; 1303 extern void init_dl_bandwidth(struct dl_bandwidth *dl_b, u64 period, u64 runtime); 1304 extern void init_dl_task_timer(struct sched_dl_entity *dl_se); 1305 1306 unsigned long to_ratio(u64 period, u64 runtime); 1307 1308 extern void init_entity_runnable_average(struct sched_entity *se); 1309 1310 static inline void add_nr_running(struct rq *rq, unsigned count) 1311 { 1312 unsigned prev_nr = rq->nr_running; 1313 1314 rq->nr_running = prev_nr + count; 1315 1316 if (prev_nr < 2 && rq->nr_running >= 2) { 1317 #ifdef CONFIG_SMP 1318 if (!rq->rd->overload) 1319 rq->rd->overload = true; 1320 #endif 1321 1322 #ifdef CONFIG_NO_HZ_FULL 1323 if (tick_nohz_full_cpu(rq->cpu)) { 1324 /* 1325 * Tick is needed if more than one task runs on a CPU. 1326 * Send the target an IPI to kick it out of nohz mode. 1327 * 1328 * We assume that IPI implies full memory barrier and the 1329 * new value of rq->nr_running is visible on reception 1330 * from the target. 1331 */ 1332 tick_nohz_full_kick_cpu(rq->cpu); 1333 } 1334 #endif 1335 } 1336 } 1337 1338 static inline void sub_nr_running(struct rq *rq, unsigned count) 1339 { 1340 rq->nr_running -= count; 1341 } 1342 1343 static inline void rq_last_tick_reset(struct rq *rq) 1344 { 1345 #ifdef CONFIG_NO_HZ_FULL 1346 rq->last_sched_tick = jiffies; 1347 #endif 1348 } 1349 1350 extern void update_rq_clock(struct rq *rq); 1351 1352 extern void activate_task(struct rq *rq, struct task_struct *p, int flags); 1353 extern void deactivate_task(struct rq *rq, struct task_struct *p, int flags); 1354 1355 extern void check_preempt_curr(struct rq *rq, struct task_struct *p, int flags); 1356 1357 extern const_debug unsigned int sysctl_sched_time_avg; 1358 extern const_debug unsigned int sysctl_sched_nr_migrate; 1359 extern const_debug unsigned int sysctl_sched_migration_cost; 1360 1361 static inline u64 sched_avg_period(void) 1362 { 1363 return (u64)sysctl_sched_time_avg * NSEC_PER_MSEC / 2; 1364 } 1365 1366 #ifdef CONFIG_SCHED_HRTICK 1367 1368 /* 1369 * Use hrtick when: 1370 * - enabled by features 1371 * - hrtimer is actually high res 1372 */ 1373 static inline int hrtick_enabled(struct rq *rq) 1374 { 1375 if (!sched_feat(HRTICK)) 1376 return 0; 1377 if (!cpu_active(cpu_of(rq))) 1378 return 0; 1379 return hrtimer_is_hres_active(&rq->hrtick_timer); 1380 } 1381 1382 void hrtick_start(struct rq *rq, u64 delay); 1383 1384 #else 1385 1386 static inline int hrtick_enabled(struct rq *rq) 1387 { 1388 return 0; 1389 } 1390 1391 #endif /* CONFIG_SCHED_HRTICK */ 1392 1393 #ifdef CONFIG_SMP 1394 extern void sched_avg_update(struct rq *rq); 1395 1396 #ifndef arch_scale_freq_capacity 1397 static __always_inline 1398 unsigned long arch_scale_freq_capacity(struct sched_domain *sd, int cpu) 1399 { 1400 return SCHED_CAPACITY_SCALE; 1401 } 1402 #endif 1403 1404 #ifndef arch_scale_cpu_capacity 1405 static __always_inline 1406 unsigned long arch_scale_cpu_capacity(struct sched_domain *sd, int cpu) 1407 { 1408 if (sd && (sd->flags & SD_SHARE_CPUCAPACITY) && (sd->span_weight > 1)) 1409 return sd->smt_gain / sd->span_weight; 1410 1411 return SCHED_CAPACITY_SCALE; 1412 } 1413 #endif 1414 1415 static inline void sched_rt_avg_update(struct rq *rq, u64 rt_delta) 1416 { 1417 rq->rt_avg += rt_delta * arch_scale_freq_capacity(NULL, cpu_of(rq)); 1418 sched_avg_update(rq); 1419 } 1420 #else 1421 static inline void sched_rt_avg_update(struct rq *rq, u64 rt_delta) { } 1422 static inline void sched_avg_update(struct rq *rq) { } 1423 #endif 1424 1425 /* 1426 * __task_rq_lock - lock the rq @p resides on. 1427 */ 1428 static inline struct rq *__task_rq_lock(struct task_struct *p) 1429 __acquires(rq->lock) 1430 { 1431 struct rq *rq; 1432 1433 lockdep_assert_held(&p->pi_lock); 1434 1435 for (;;) { 1436 rq = task_rq(p); 1437 raw_spin_lock(&rq->lock); 1438 if (likely(rq == task_rq(p) && !task_on_rq_migrating(p))) { 1439 lockdep_pin_lock(&rq->lock); 1440 return rq; 1441 } 1442 raw_spin_unlock(&rq->lock); 1443 1444 while (unlikely(task_on_rq_migrating(p))) 1445 cpu_relax(); 1446 } 1447 } 1448 1449 /* 1450 * task_rq_lock - lock p->pi_lock and lock the rq @p resides on. 1451 */ 1452 static inline struct rq *task_rq_lock(struct task_struct *p, unsigned long *flags) 1453 __acquires(p->pi_lock) 1454 __acquires(rq->lock) 1455 { 1456 struct rq *rq; 1457 1458 for (;;) { 1459 raw_spin_lock_irqsave(&p->pi_lock, *flags); 1460 rq = task_rq(p); 1461 raw_spin_lock(&rq->lock); 1462 /* 1463 * move_queued_task() task_rq_lock() 1464 * 1465 * ACQUIRE (rq->lock) 1466 * [S] ->on_rq = MIGRATING [L] rq = task_rq() 1467 * WMB (__set_task_cpu()) ACQUIRE (rq->lock); 1468 * [S] ->cpu = new_cpu [L] task_rq() 1469 * [L] ->on_rq 1470 * RELEASE (rq->lock) 1471 * 1472 * If we observe the old cpu in task_rq_lock, the acquire of 1473 * the old rq->lock will fully serialize against the stores. 1474 * 1475 * If we observe the new cpu in task_rq_lock, the acquire will 1476 * pair with the WMB to ensure we must then also see migrating. 1477 */ 1478 if (likely(rq == task_rq(p) && !task_on_rq_migrating(p))) { 1479 lockdep_pin_lock(&rq->lock); 1480 return rq; 1481 } 1482 raw_spin_unlock(&rq->lock); 1483 raw_spin_unlock_irqrestore(&p->pi_lock, *flags); 1484 1485 while (unlikely(task_on_rq_migrating(p))) 1486 cpu_relax(); 1487 } 1488 } 1489 1490 static inline void __task_rq_unlock(struct rq *rq) 1491 __releases(rq->lock) 1492 { 1493 lockdep_unpin_lock(&rq->lock); 1494 raw_spin_unlock(&rq->lock); 1495 } 1496 1497 static inline void 1498 task_rq_unlock(struct rq *rq, struct task_struct *p, unsigned long *flags) 1499 __releases(rq->lock) 1500 __releases(p->pi_lock) 1501 { 1502 lockdep_unpin_lock(&rq->lock); 1503 raw_spin_unlock(&rq->lock); 1504 raw_spin_unlock_irqrestore(&p->pi_lock, *flags); 1505 } 1506 1507 #ifdef CONFIG_SMP 1508 #ifdef CONFIG_PREEMPT 1509 1510 static inline void double_rq_lock(struct rq *rq1, struct rq *rq2); 1511 1512 /* 1513 * fair double_lock_balance: Safely acquires both rq->locks in a fair 1514 * way at the expense of forcing extra atomic operations in all 1515 * invocations. This assures that the double_lock is acquired using the 1516 * same underlying policy as the spinlock_t on this architecture, which 1517 * reduces latency compared to the unfair variant below. However, it 1518 * also adds more overhead and therefore may reduce throughput. 1519 */ 1520 static inline int _double_lock_balance(struct rq *this_rq, struct rq *busiest) 1521 __releases(this_rq->lock) 1522 __acquires(busiest->lock) 1523 __acquires(this_rq->lock) 1524 { 1525 raw_spin_unlock(&this_rq->lock); 1526 double_rq_lock(this_rq, busiest); 1527 1528 return 1; 1529 } 1530 1531 #else 1532 /* 1533 * Unfair double_lock_balance: Optimizes throughput at the expense of 1534 * latency by eliminating extra atomic operations when the locks are 1535 * already in proper order on entry. This favors lower cpu-ids and will 1536 * grant the double lock to lower cpus over higher ids under contention, 1537 * regardless of entry order into the function. 1538 */ 1539 static inline int _double_lock_balance(struct rq *this_rq, struct rq *busiest) 1540 __releases(this_rq->lock) 1541 __acquires(busiest->lock) 1542 __acquires(this_rq->lock) 1543 { 1544 int ret = 0; 1545 1546 if (unlikely(!raw_spin_trylock(&busiest->lock))) { 1547 if (busiest < this_rq) { 1548 raw_spin_unlock(&this_rq->lock); 1549 raw_spin_lock(&busiest->lock); 1550 raw_spin_lock_nested(&this_rq->lock, 1551 SINGLE_DEPTH_NESTING); 1552 ret = 1; 1553 } else 1554 raw_spin_lock_nested(&busiest->lock, 1555 SINGLE_DEPTH_NESTING); 1556 } 1557 return ret; 1558 } 1559 1560 #endif /* CONFIG_PREEMPT */ 1561 1562 /* 1563 * double_lock_balance - lock the busiest runqueue, this_rq is locked already. 1564 */ 1565 static inline int double_lock_balance(struct rq *this_rq, struct rq *busiest) 1566 { 1567 if (unlikely(!irqs_disabled())) { 1568 /* printk() doesn't work good under rq->lock */ 1569 raw_spin_unlock(&this_rq->lock); 1570 BUG_ON(1); 1571 } 1572 1573 return _double_lock_balance(this_rq, busiest); 1574 } 1575 1576 static inline void double_unlock_balance(struct rq *this_rq, struct rq *busiest) 1577 __releases(busiest->lock) 1578 { 1579 raw_spin_unlock(&busiest->lock); 1580 lock_set_subclass(&this_rq->lock.dep_map, 0, _RET_IP_); 1581 } 1582 1583 static inline void double_lock(spinlock_t *l1, spinlock_t *l2) 1584 { 1585 if (l1 > l2) 1586 swap(l1, l2); 1587 1588 spin_lock(l1); 1589 spin_lock_nested(l2, SINGLE_DEPTH_NESTING); 1590 } 1591 1592 static inline void double_lock_irq(spinlock_t *l1, spinlock_t *l2) 1593 { 1594 if (l1 > l2) 1595 swap(l1, l2); 1596 1597 spin_lock_irq(l1); 1598 spin_lock_nested(l2, SINGLE_DEPTH_NESTING); 1599 } 1600 1601 static inline void double_raw_lock(raw_spinlock_t *l1, raw_spinlock_t *l2) 1602 { 1603 if (l1 > l2) 1604 swap(l1, l2); 1605 1606 raw_spin_lock(l1); 1607 raw_spin_lock_nested(l2, SINGLE_DEPTH_NESTING); 1608 } 1609 1610 /* 1611 * double_rq_lock - safely lock two runqueues 1612 * 1613 * Note this does not disable interrupts like task_rq_lock, 1614 * you need to do so manually before calling. 1615 */ 1616 static inline void double_rq_lock(struct rq *rq1, struct rq *rq2) 1617 __acquires(rq1->lock) 1618 __acquires(rq2->lock) 1619 { 1620 BUG_ON(!irqs_disabled()); 1621 if (rq1 == rq2) { 1622 raw_spin_lock(&rq1->lock); 1623 __acquire(rq2->lock); /* Fake it out ;) */ 1624 } else { 1625 if (rq1 < rq2) { 1626 raw_spin_lock(&rq1->lock); 1627 raw_spin_lock_nested(&rq2->lock, SINGLE_DEPTH_NESTING); 1628 } else { 1629 raw_spin_lock(&rq2->lock); 1630 raw_spin_lock_nested(&rq1->lock, SINGLE_DEPTH_NESTING); 1631 } 1632 } 1633 } 1634 1635 /* 1636 * double_rq_unlock - safely unlock two runqueues 1637 * 1638 * Note this does not restore interrupts like task_rq_unlock, 1639 * you need to do so manually after calling. 1640 */ 1641 static inline void double_rq_unlock(struct rq *rq1, struct rq *rq2) 1642 __releases(rq1->lock) 1643 __releases(rq2->lock) 1644 { 1645 raw_spin_unlock(&rq1->lock); 1646 if (rq1 != rq2) 1647 raw_spin_unlock(&rq2->lock); 1648 else 1649 __release(rq2->lock); 1650 } 1651 1652 #else /* CONFIG_SMP */ 1653 1654 /* 1655 * double_rq_lock - safely lock two runqueues 1656 * 1657 * Note this does not disable interrupts like task_rq_lock, 1658 * you need to do so manually before calling. 1659 */ 1660 static inline void double_rq_lock(struct rq *rq1, struct rq *rq2) 1661 __acquires(rq1->lock) 1662 __acquires(rq2->lock) 1663 { 1664 BUG_ON(!irqs_disabled()); 1665 BUG_ON(rq1 != rq2); 1666 raw_spin_lock(&rq1->lock); 1667 __acquire(rq2->lock); /* Fake it out ;) */ 1668 } 1669 1670 /* 1671 * double_rq_unlock - safely unlock two runqueues 1672 * 1673 * Note this does not restore interrupts like task_rq_unlock, 1674 * you need to do so manually after calling. 1675 */ 1676 static inline void double_rq_unlock(struct rq *rq1, struct rq *rq2) 1677 __releases(rq1->lock) 1678 __releases(rq2->lock) 1679 { 1680 BUG_ON(rq1 != rq2); 1681 raw_spin_unlock(&rq1->lock); 1682 __release(rq2->lock); 1683 } 1684 1685 #endif 1686 1687 extern struct sched_entity *__pick_first_entity(struct cfs_rq *cfs_rq); 1688 extern struct sched_entity *__pick_last_entity(struct cfs_rq *cfs_rq); 1689 1690 #ifdef CONFIG_SCHED_DEBUG 1691 extern void print_cfs_stats(struct seq_file *m, int cpu); 1692 extern void print_rt_stats(struct seq_file *m, int cpu); 1693 extern void print_dl_stats(struct seq_file *m, int cpu); 1694 extern void 1695 print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq); 1696 1697 #ifdef CONFIG_NUMA_BALANCING 1698 extern void 1699 show_numa_stats(struct task_struct *p, struct seq_file *m); 1700 extern void 1701 print_numa_stats(struct seq_file *m, int node, unsigned long tsf, 1702 unsigned long tpf, unsigned long gsf, unsigned long gpf); 1703 #endif /* CONFIG_NUMA_BALANCING */ 1704 #endif /* CONFIG_SCHED_DEBUG */ 1705 1706 extern void init_cfs_rq(struct cfs_rq *cfs_rq); 1707 extern void init_rt_rq(struct rt_rq *rt_rq); 1708 extern void init_dl_rq(struct dl_rq *dl_rq); 1709 1710 extern void cfs_bandwidth_usage_inc(void); 1711 extern void cfs_bandwidth_usage_dec(void); 1712 1713 #ifdef CONFIG_NO_HZ_COMMON 1714 enum rq_nohz_flag_bits { 1715 NOHZ_TICK_STOPPED, 1716 NOHZ_BALANCE_KICK, 1717 }; 1718 1719 #define nohz_flags(cpu) (&cpu_rq(cpu)->nohz_flags) 1720 #endif 1721 1722 #ifdef CONFIG_IRQ_TIME_ACCOUNTING 1723 1724 DECLARE_PER_CPU(u64, cpu_hardirq_time); 1725 DECLARE_PER_CPU(u64, cpu_softirq_time); 1726 1727 #ifndef CONFIG_64BIT 1728 DECLARE_PER_CPU(seqcount_t, irq_time_seq); 1729 1730 static inline void irq_time_write_begin(void) 1731 { 1732 __this_cpu_inc(irq_time_seq.sequence); 1733 smp_wmb(); 1734 } 1735 1736 static inline void irq_time_write_end(void) 1737 { 1738 smp_wmb(); 1739 __this_cpu_inc(irq_time_seq.sequence); 1740 } 1741 1742 static inline u64 irq_time_read(int cpu) 1743 { 1744 u64 irq_time; 1745 unsigned seq; 1746 1747 do { 1748 seq = read_seqcount_begin(&per_cpu(irq_time_seq, cpu)); 1749 irq_time = per_cpu(cpu_softirq_time, cpu) + 1750 per_cpu(cpu_hardirq_time, cpu); 1751 } while (read_seqcount_retry(&per_cpu(irq_time_seq, cpu), seq)); 1752 1753 return irq_time; 1754 } 1755 #else /* CONFIG_64BIT */ 1756 static inline void irq_time_write_begin(void) 1757 { 1758 } 1759 1760 static inline void irq_time_write_end(void) 1761 { 1762 } 1763 1764 static inline u64 irq_time_read(int cpu) 1765 { 1766 return per_cpu(cpu_softirq_time, cpu) + per_cpu(cpu_hardirq_time, cpu); 1767 } 1768 #endif /* CONFIG_64BIT */ 1769 #endif /* CONFIG_IRQ_TIME_ACCOUNTING */ 1770