1 2 #include <linux/sched.h> 3 #include <linux/sched/autogroup.h> 4 #include <linux/sched/sysctl.h> 5 #include <linux/sched/topology.h> 6 #include <linux/sched/rt.h> 7 #include <linux/sched/deadline.h> 8 #include <linux/sched/clock.h> 9 #include <linux/sched/wake_q.h> 10 #include <linux/sched/signal.h> 11 #include <linux/sched/numa_balancing.h> 12 #include <linux/sched/mm.h> 13 #include <linux/sched/cpufreq.h> 14 #include <linux/sched/stat.h> 15 #include <linux/sched/nohz.h> 16 #include <linux/sched/debug.h> 17 #include <linux/sched/hotplug.h> 18 #include <linux/sched/task.h> 19 #include <linux/sched/task_stack.h> 20 #include <linux/sched/cputime.h> 21 #include <linux/sched/init.h> 22 23 #include <linux/u64_stats_sync.h> 24 #include <linux/kernel_stat.h> 25 #include <linux/binfmts.h> 26 #include <linux/mutex.h> 27 #include <linux/spinlock.h> 28 #include <linux/stop_machine.h> 29 #include <linux/irq_work.h> 30 #include <linux/tick.h> 31 #include <linux/slab.h> 32 33 #ifdef CONFIG_PARAVIRT 34 #include <asm/paravirt.h> 35 #endif 36 37 #include "cpupri.h" 38 #include "cpudeadline.h" 39 #include "cpuacct.h" 40 41 #ifdef CONFIG_SCHED_DEBUG 42 #define SCHED_WARN_ON(x) WARN_ONCE(x, #x) 43 #else 44 #define SCHED_WARN_ON(x) ((void)(x)) 45 #endif 46 47 struct rq; 48 struct cpuidle_state; 49 50 /* task_struct::on_rq states: */ 51 #define TASK_ON_RQ_QUEUED 1 52 #define TASK_ON_RQ_MIGRATING 2 53 54 extern __read_mostly int scheduler_running; 55 56 extern unsigned long calc_load_update; 57 extern atomic_long_t calc_load_tasks; 58 59 extern void calc_global_load_tick(struct rq *this_rq); 60 extern long calc_load_fold_active(struct rq *this_rq, long adjust); 61 62 #ifdef CONFIG_SMP 63 extern void cpu_load_update_active(struct rq *this_rq); 64 #else 65 static inline void cpu_load_update_active(struct rq *this_rq) { } 66 #endif 67 68 /* 69 * Helpers for converting nanosecond timing to jiffy resolution 70 */ 71 #define NS_TO_JIFFIES(TIME) ((unsigned long)(TIME) / (NSEC_PER_SEC / HZ)) 72 73 /* 74 * Increase resolution of nice-level calculations for 64-bit architectures. 75 * The extra resolution improves shares distribution and load balancing of 76 * low-weight task groups (eg. nice +19 on an autogroup), deeper taskgroup 77 * hierarchies, especially on larger systems. This is not a user-visible change 78 * and does not change the user-interface for setting shares/weights. 79 * 80 * We increase resolution only if we have enough bits to allow this increased 81 * resolution (i.e. 64bit). The costs for increasing resolution when 32bit are 82 * pretty high and the returns do not justify the increased costs. 83 * 84 * Really only required when CONFIG_FAIR_GROUP_SCHED is also set, but to 85 * increase coverage and consistency always enable it on 64bit platforms. 86 */ 87 #ifdef CONFIG_64BIT 88 # define NICE_0_LOAD_SHIFT (SCHED_FIXEDPOINT_SHIFT + SCHED_FIXEDPOINT_SHIFT) 89 # define scale_load(w) ((w) << SCHED_FIXEDPOINT_SHIFT) 90 # define scale_load_down(w) ((w) >> SCHED_FIXEDPOINT_SHIFT) 91 #else 92 # define NICE_0_LOAD_SHIFT (SCHED_FIXEDPOINT_SHIFT) 93 # define scale_load(w) (w) 94 # define scale_load_down(w) (w) 95 #endif 96 97 /* 98 * Task weight (visible to users) and its load (invisible to users) have 99 * independent resolution, but they should be well calibrated. We use 100 * scale_load() and scale_load_down(w) to convert between them. The 101 * following must be true: 102 * 103 * scale_load(sched_prio_to_weight[USER_PRIO(NICE_TO_PRIO(0))]) == NICE_0_LOAD 104 * 105 */ 106 #define NICE_0_LOAD (1L << NICE_0_LOAD_SHIFT) 107 108 /* 109 * Single value that decides SCHED_DEADLINE internal math precision. 110 * 10 -> just above 1us 111 * 9 -> just above 0.5us 112 */ 113 #define DL_SCALE (10) 114 115 /* 116 * These are the 'tuning knobs' of the scheduler: 117 */ 118 119 /* 120 * single value that denotes runtime == period, ie unlimited time. 121 */ 122 #define RUNTIME_INF ((u64)~0ULL) 123 124 static inline int idle_policy(int policy) 125 { 126 return policy == SCHED_IDLE; 127 } 128 static inline int fair_policy(int policy) 129 { 130 return policy == SCHED_NORMAL || policy == SCHED_BATCH; 131 } 132 133 static inline int rt_policy(int policy) 134 { 135 return policy == SCHED_FIFO || policy == SCHED_RR; 136 } 137 138 static inline int dl_policy(int policy) 139 { 140 return policy == SCHED_DEADLINE; 141 } 142 static inline bool valid_policy(int policy) 143 { 144 return idle_policy(policy) || fair_policy(policy) || 145 rt_policy(policy) || dl_policy(policy); 146 } 147 148 static inline int task_has_rt_policy(struct task_struct *p) 149 { 150 return rt_policy(p->policy); 151 } 152 153 static inline int task_has_dl_policy(struct task_struct *p) 154 { 155 return dl_policy(p->policy); 156 } 157 158 /* 159 * Tells if entity @a should preempt entity @b. 160 */ 161 static inline bool 162 dl_entity_preempt(struct sched_dl_entity *a, struct sched_dl_entity *b) 163 { 164 return dl_time_before(a->deadline, b->deadline); 165 } 166 167 /* 168 * This is the priority-queue data structure of the RT scheduling class: 169 */ 170 struct rt_prio_array { 171 DECLARE_BITMAP(bitmap, MAX_RT_PRIO+1); /* include 1 bit for delimiter */ 172 struct list_head queue[MAX_RT_PRIO]; 173 }; 174 175 struct rt_bandwidth { 176 /* nests inside the rq lock: */ 177 raw_spinlock_t rt_runtime_lock; 178 ktime_t rt_period; 179 u64 rt_runtime; 180 struct hrtimer rt_period_timer; 181 unsigned int rt_period_active; 182 }; 183 184 void __dl_clear_params(struct task_struct *p); 185 186 /* 187 * To keep the bandwidth of -deadline tasks and groups under control 188 * we need some place where: 189 * - store the maximum -deadline bandwidth of the system (the group); 190 * - cache the fraction of that bandwidth that is currently allocated. 191 * 192 * This is all done in the data structure below. It is similar to the 193 * one used for RT-throttling (rt_bandwidth), with the main difference 194 * that, since here we are only interested in admission control, we 195 * do not decrease any runtime while the group "executes", neither we 196 * need a timer to replenish it. 197 * 198 * With respect to SMP, the bandwidth is given on a per-CPU basis, 199 * meaning that: 200 * - dl_bw (< 100%) is the bandwidth of the system (group) on each CPU; 201 * - dl_total_bw array contains, in the i-eth element, the currently 202 * allocated bandwidth on the i-eth CPU. 203 * Moreover, groups consume bandwidth on each CPU, while tasks only 204 * consume bandwidth on the CPU they're running on. 205 * Finally, dl_total_bw_cpu is used to cache the index of dl_total_bw 206 * that will be shown the next time the proc or cgroup controls will 207 * be red. It on its turn can be changed by writing on its own 208 * control. 209 */ 210 struct dl_bandwidth { 211 raw_spinlock_t dl_runtime_lock; 212 u64 dl_runtime; 213 u64 dl_period; 214 }; 215 216 static inline int dl_bandwidth_enabled(void) 217 { 218 return sysctl_sched_rt_runtime >= 0; 219 } 220 221 extern struct dl_bw *dl_bw_of(int i); 222 223 struct dl_bw { 224 raw_spinlock_t lock; 225 u64 bw, total_bw; 226 }; 227 228 static inline 229 void __dl_clear(struct dl_bw *dl_b, u64 tsk_bw) 230 { 231 dl_b->total_bw -= tsk_bw; 232 } 233 234 static inline 235 void __dl_add(struct dl_bw *dl_b, u64 tsk_bw) 236 { 237 dl_b->total_bw += tsk_bw; 238 } 239 240 static inline 241 bool __dl_overflow(struct dl_bw *dl_b, int cpus, u64 old_bw, u64 new_bw) 242 { 243 return dl_b->bw != -1 && 244 dl_b->bw * cpus < dl_b->total_bw - old_bw + new_bw; 245 } 246 247 extern void init_dl_bw(struct dl_bw *dl_b); 248 249 #ifdef CONFIG_CGROUP_SCHED 250 251 #include <linux/cgroup.h> 252 253 struct cfs_rq; 254 struct rt_rq; 255 256 extern struct list_head task_groups; 257 258 struct cfs_bandwidth { 259 #ifdef CONFIG_CFS_BANDWIDTH 260 raw_spinlock_t lock; 261 ktime_t period; 262 u64 quota, runtime; 263 s64 hierarchical_quota; 264 u64 runtime_expires; 265 266 int idle, period_active; 267 struct hrtimer period_timer, slack_timer; 268 struct list_head throttled_cfs_rq; 269 270 /* statistics */ 271 int nr_periods, nr_throttled; 272 u64 throttled_time; 273 #endif 274 }; 275 276 /* task group related information */ 277 struct task_group { 278 struct cgroup_subsys_state css; 279 280 #ifdef CONFIG_FAIR_GROUP_SCHED 281 /* schedulable entities of this group on each cpu */ 282 struct sched_entity **se; 283 /* runqueue "owned" by this group on each cpu */ 284 struct cfs_rq **cfs_rq; 285 unsigned long shares; 286 287 #ifdef CONFIG_SMP 288 /* 289 * load_avg can be heavily contended at clock tick time, so put 290 * it in its own cacheline separated from the fields above which 291 * will also be accessed at each tick. 292 */ 293 atomic_long_t load_avg ____cacheline_aligned; 294 #endif 295 #endif 296 297 #ifdef CONFIG_RT_GROUP_SCHED 298 struct sched_rt_entity **rt_se; 299 struct rt_rq **rt_rq; 300 301 struct rt_bandwidth rt_bandwidth; 302 #endif 303 304 struct rcu_head rcu; 305 struct list_head list; 306 307 struct task_group *parent; 308 struct list_head siblings; 309 struct list_head children; 310 311 #ifdef CONFIG_SCHED_AUTOGROUP 312 struct autogroup *autogroup; 313 #endif 314 315 struct cfs_bandwidth cfs_bandwidth; 316 }; 317 318 #ifdef CONFIG_FAIR_GROUP_SCHED 319 #define ROOT_TASK_GROUP_LOAD NICE_0_LOAD 320 321 /* 322 * A weight of 0 or 1 can cause arithmetics problems. 323 * A weight of a cfs_rq is the sum of weights of which entities 324 * are queued on this cfs_rq, so a weight of a entity should not be 325 * too large, so as the shares value of a task group. 326 * (The default weight is 1024 - so there's no practical 327 * limitation from this.) 328 */ 329 #define MIN_SHARES (1UL << 1) 330 #define MAX_SHARES (1UL << 18) 331 #endif 332 333 typedef int (*tg_visitor)(struct task_group *, void *); 334 335 extern int walk_tg_tree_from(struct task_group *from, 336 tg_visitor down, tg_visitor up, void *data); 337 338 /* 339 * Iterate the full tree, calling @down when first entering a node and @up when 340 * leaving it for the final time. 341 * 342 * Caller must hold rcu_lock or sufficient equivalent. 343 */ 344 static inline int walk_tg_tree(tg_visitor down, tg_visitor up, void *data) 345 { 346 return walk_tg_tree_from(&root_task_group, down, up, data); 347 } 348 349 extern int tg_nop(struct task_group *tg, void *data); 350 351 extern void free_fair_sched_group(struct task_group *tg); 352 extern int alloc_fair_sched_group(struct task_group *tg, struct task_group *parent); 353 extern void online_fair_sched_group(struct task_group *tg); 354 extern void unregister_fair_sched_group(struct task_group *tg); 355 extern void init_tg_cfs_entry(struct task_group *tg, struct cfs_rq *cfs_rq, 356 struct sched_entity *se, int cpu, 357 struct sched_entity *parent); 358 extern void init_cfs_bandwidth(struct cfs_bandwidth *cfs_b); 359 360 extern void __refill_cfs_bandwidth_runtime(struct cfs_bandwidth *cfs_b); 361 extern void start_cfs_bandwidth(struct cfs_bandwidth *cfs_b); 362 extern void unthrottle_cfs_rq(struct cfs_rq *cfs_rq); 363 364 extern void free_rt_sched_group(struct task_group *tg); 365 extern int alloc_rt_sched_group(struct task_group *tg, struct task_group *parent); 366 extern void init_tg_rt_entry(struct task_group *tg, struct rt_rq *rt_rq, 367 struct sched_rt_entity *rt_se, int cpu, 368 struct sched_rt_entity *parent); 369 370 extern struct task_group *sched_create_group(struct task_group *parent); 371 extern void sched_online_group(struct task_group *tg, 372 struct task_group *parent); 373 extern void sched_destroy_group(struct task_group *tg); 374 extern void sched_offline_group(struct task_group *tg); 375 376 extern void sched_move_task(struct task_struct *tsk); 377 378 #ifdef CONFIG_FAIR_GROUP_SCHED 379 extern int sched_group_set_shares(struct task_group *tg, unsigned long shares); 380 381 #ifdef CONFIG_SMP 382 extern void set_task_rq_fair(struct sched_entity *se, 383 struct cfs_rq *prev, struct cfs_rq *next); 384 #else /* !CONFIG_SMP */ 385 static inline void set_task_rq_fair(struct sched_entity *se, 386 struct cfs_rq *prev, struct cfs_rq *next) { } 387 #endif /* CONFIG_SMP */ 388 #endif /* CONFIG_FAIR_GROUP_SCHED */ 389 390 #else /* CONFIG_CGROUP_SCHED */ 391 392 struct cfs_bandwidth { }; 393 394 #endif /* CONFIG_CGROUP_SCHED */ 395 396 /* CFS-related fields in a runqueue */ 397 struct cfs_rq { 398 struct load_weight load; 399 unsigned int nr_running, h_nr_running; 400 401 u64 exec_clock; 402 u64 min_vruntime; 403 #ifndef CONFIG_64BIT 404 u64 min_vruntime_copy; 405 #endif 406 407 struct rb_root tasks_timeline; 408 struct rb_node *rb_leftmost; 409 410 /* 411 * 'curr' points to currently running entity on this cfs_rq. 412 * It is set to NULL otherwise (i.e when none are currently running). 413 */ 414 struct sched_entity *curr, *next, *last, *skip; 415 416 #ifdef CONFIG_SCHED_DEBUG 417 unsigned int nr_spread_over; 418 #endif 419 420 #ifdef CONFIG_SMP 421 /* 422 * CFS load tracking 423 */ 424 struct sched_avg avg; 425 u64 runnable_load_sum; 426 unsigned long runnable_load_avg; 427 #ifdef CONFIG_FAIR_GROUP_SCHED 428 unsigned long tg_load_avg_contrib; 429 unsigned long propagate_avg; 430 #endif 431 atomic_long_t removed_load_avg, removed_util_avg; 432 #ifndef CONFIG_64BIT 433 u64 load_last_update_time_copy; 434 #endif 435 436 #ifdef CONFIG_FAIR_GROUP_SCHED 437 /* 438 * h_load = weight * f(tg) 439 * 440 * Where f(tg) is the recursive weight fraction assigned to 441 * this group. 442 */ 443 unsigned long h_load; 444 u64 last_h_load_update; 445 struct sched_entity *h_load_next; 446 #endif /* CONFIG_FAIR_GROUP_SCHED */ 447 #endif /* CONFIG_SMP */ 448 449 #ifdef CONFIG_FAIR_GROUP_SCHED 450 struct rq *rq; /* cpu runqueue to which this cfs_rq is attached */ 451 452 /* 453 * leaf cfs_rqs are those that hold tasks (lowest schedulable entity in 454 * a hierarchy). Non-leaf lrqs hold other higher schedulable entities 455 * (like users, containers etc.) 456 * 457 * leaf_cfs_rq_list ties together list of leaf cfs_rq's in a cpu. This 458 * list is used during load balance. 459 */ 460 int on_list; 461 struct list_head leaf_cfs_rq_list; 462 struct task_group *tg; /* group that "owns" this runqueue */ 463 464 #ifdef CONFIG_CFS_BANDWIDTH 465 int runtime_enabled; 466 u64 runtime_expires; 467 s64 runtime_remaining; 468 469 u64 throttled_clock, throttled_clock_task; 470 u64 throttled_clock_task_time; 471 int throttled, throttle_count; 472 struct list_head throttled_list; 473 #endif /* CONFIG_CFS_BANDWIDTH */ 474 #endif /* CONFIG_FAIR_GROUP_SCHED */ 475 }; 476 477 static inline int rt_bandwidth_enabled(void) 478 { 479 return sysctl_sched_rt_runtime >= 0; 480 } 481 482 /* RT IPI pull logic requires IRQ_WORK */ 483 #ifdef CONFIG_IRQ_WORK 484 # define HAVE_RT_PUSH_IPI 485 #endif 486 487 /* Real-Time classes' related field in a runqueue: */ 488 struct rt_rq { 489 struct rt_prio_array active; 490 unsigned int rt_nr_running; 491 unsigned int rr_nr_running; 492 #if defined CONFIG_SMP || defined CONFIG_RT_GROUP_SCHED 493 struct { 494 int curr; /* highest queued rt task prio */ 495 #ifdef CONFIG_SMP 496 int next; /* next highest */ 497 #endif 498 } highest_prio; 499 #endif 500 #ifdef CONFIG_SMP 501 unsigned long rt_nr_migratory; 502 unsigned long rt_nr_total; 503 int overloaded; 504 struct plist_head pushable_tasks; 505 #ifdef HAVE_RT_PUSH_IPI 506 int push_flags; 507 int push_cpu; 508 struct irq_work push_work; 509 raw_spinlock_t push_lock; 510 #endif 511 #endif /* CONFIG_SMP */ 512 int rt_queued; 513 514 int rt_throttled; 515 u64 rt_time; 516 u64 rt_runtime; 517 /* Nests inside the rq lock: */ 518 raw_spinlock_t rt_runtime_lock; 519 520 #ifdef CONFIG_RT_GROUP_SCHED 521 unsigned long rt_nr_boosted; 522 523 struct rq *rq; 524 struct task_group *tg; 525 #endif 526 }; 527 528 /* Deadline class' related fields in a runqueue */ 529 struct dl_rq { 530 /* runqueue is an rbtree, ordered by deadline */ 531 struct rb_root rb_root; 532 struct rb_node *rb_leftmost; 533 534 unsigned long dl_nr_running; 535 536 #ifdef CONFIG_SMP 537 /* 538 * Deadline values of the currently executing and the 539 * earliest ready task on this rq. Caching these facilitates 540 * the decision wether or not a ready but not running task 541 * should migrate somewhere else. 542 */ 543 struct { 544 u64 curr; 545 u64 next; 546 } earliest_dl; 547 548 unsigned long dl_nr_migratory; 549 int overloaded; 550 551 /* 552 * Tasks on this rq that can be pushed away. They are kept in 553 * an rb-tree, ordered by tasks' deadlines, with caching 554 * of the leftmost (earliest deadline) element. 555 */ 556 struct rb_root pushable_dl_tasks_root; 557 struct rb_node *pushable_dl_tasks_leftmost; 558 #else 559 struct dl_bw dl_bw; 560 #endif 561 }; 562 563 #ifdef CONFIG_SMP 564 565 static inline bool sched_asym_prefer(int a, int b) 566 { 567 return arch_asym_cpu_priority(a) > arch_asym_cpu_priority(b); 568 } 569 570 /* 571 * We add the notion of a root-domain which will be used to define per-domain 572 * variables. Each exclusive cpuset essentially defines an island domain by 573 * fully partitioning the member cpus from any other cpuset. Whenever a new 574 * exclusive cpuset is created, we also create and attach a new root-domain 575 * object. 576 * 577 */ 578 struct root_domain { 579 atomic_t refcount; 580 atomic_t rto_count; 581 struct rcu_head rcu; 582 cpumask_var_t span; 583 cpumask_var_t online; 584 585 /* Indicate more than one runnable task for any CPU */ 586 bool overload; 587 588 /* 589 * The bit corresponding to a CPU gets set here if such CPU has more 590 * than one runnable -deadline task (as it is below for RT tasks). 591 */ 592 cpumask_var_t dlo_mask; 593 atomic_t dlo_count; 594 struct dl_bw dl_bw; 595 struct cpudl cpudl; 596 597 /* 598 * The "RT overload" flag: it gets set if a CPU has more than 599 * one runnable RT task. 600 */ 601 cpumask_var_t rto_mask; 602 struct cpupri cpupri; 603 604 unsigned long max_cpu_capacity; 605 }; 606 607 extern struct root_domain def_root_domain; 608 extern struct mutex sched_domains_mutex; 609 extern cpumask_var_t fallback_doms; 610 extern cpumask_var_t sched_domains_tmpmask; 611 612 extern void init_defrootdomain(void); 613 extern int init_sched_domains(const struct cpumask *cpu_map); 614 extern void rq_attach_root(struct rq *rq, struct root_domain *rd); 615 616 #endif /* CONFIG_SMP */ 617 618 /* 619 * This is the main, per-CPU runqueue data structure. 620 * 621 * Locking rule: those places that want to lock multiple runqueues 622 * (such as the load balancing or the thread migration code), lock 623 * acquire operations must be ordered by ascending &runqueue. 624 */ 625 struct rq { 626 /* runqueue lock: */ 627 raw_spinlock_t lock; 628 629 /* 630 * nr_running and cpu_load should be in the same cacheline because 631 * remote CPUs use both these fields when doing load calculation. 632 */ 633 unsigned int nr_running; 634 #ifdef CONFIG_NUMA_BALANCING 635 unsigned int nr_numa_running; 636 unsigned int nr_preferred_running; 637 #endif 638 #define CPU_LOAD_IDX_MAX 5 639 unsigned long cpu_load[CPU_LOAD_IDX_MAX]; 640 #ifdef CONFIG_NO_HZ_COMMON 641 #ifdef CONFIG_SMP 642 unsigned long last_load_update_tick; 643 #endif /* CONFIG_SMP */ 644 unsigned long nohz_flags; 645 #endif /* CONFIG_NO_HZ_COMMON */ 646 #ifdef CONFIG_NO_HZ_FULL 647 unsigned long last_sched_tick; 648 #endif 649 /* capture load from *all* tasks on this cpu: */ 650 struct load_weight load; 651 unsigned long nr_load_updates; 652 u64 nr_switches; 653 654 struct cfs_rq cfs; 655 struct rt_rq rt; 656 struct dl_rq dl; 657 658 #ifdef CONFIG_FAIR_GROUP_SCHED 659 /* list of leaf cfs_rq on this cpu: */ 660 struct list_head leaf_cfs_rq_list; 661 struct list_head *tmp_alone_branch; 662 #endif /* CONFIG_FAIR_GROUP_SCHED */ 663 664 /* 665 * This is part of a global counter where only the total sum 666 * over all CPUs matters. A task can increase this counter on 667 * one CPU and if it got migrated afterwards it may decrease 668 * it on another CPU. Always updated under the runqueue lock: 669 */ 670 unsigned long nr_uninterruptible; 671 672 struct task_struct *curr, *idle, *stop; 673 unsigned long next_balance; 674 struct mm_struct *prev_mm; 675 676 unsigned int clock_update_flags; 677 u64 clock; 678 u64 clock_task; 679 680 atomic_t nr_iowait; 681 682 #ifdef CONFIG_SMP 683 struct root_domain *rd; 684 struct sched_domain *sd; 685 686 unsigned long cpu_capacity; 687 unsigned long cpu_capacity_orig; 688 689 struct callback_head *balance_callback; 690 691 unsigned char idle_balance; 692 /* For active balancing */ 693 int active_balance; 694 int push_cpu; 695 struct cpu_stop_work active_balance_work; 696 /* cpu of this runqueue: */ 697 int cpu; 698 int online; 699 700 struct list_head cfs_tasks; 701 702 u64 rt_avg; 703 u64 age_stamp; 704 u64 idle_stamp; 705 u64 avg_idle; 706 707 /* This is used to determine avg_idle's max value */ 708 u64 max_idle_balance_cost; 709 #endif 710 711 #ifdef CONFIG_IRQ_TIME_ACCOUNTING 712 u64 prev_irq_time; 713 #endif 714 #ifdef CONFIG_PARAVIRT 715 u64 prev_steal_time; 716 #endif 717 #ifdef CONFIG_PARAVIRT_TIME_ACCOUNTING 718 u64 prev_steal_time_rq; 719 #endif 720 721 /* calc_load related fields */ 722 unsigned long calc_load_update; 723 long calc_load_active; 724 725 #ifdef CONFIG_SCHED_HRTICK 726 #ifdef CONFIG_SMP 727 int hrtick_csd_pending; 728 struct call_single_data hrtick_csd; 729 #endif 730 struct hrtimer hrtick_timer; 731 #endif 732 733 #ifdef CONFIG_SCHEDSTATS 734 /* latency stats */ 735 struct sched_info rq_sched_info; 736 unsigned long long rq_cpu_time; 737 /* could above be rq->cfs_rq.exec_clock + rq->rt_rq.rt_runtime ? */ 738 739 /* sys_sched_yield() stats */ 740 unsigned int yld_count; 741 742 /* schedule() stats */ 743 unsigned int sched_count; 744 unsigned int sched_goidle; 745 746 /* try_to_wake_up() stats */ 747 unsigned int ttwu_count; 748 unsigned int ttwu_local; 749 #endif 750 751 #ifdef CONFIG_SMP 752 struct llist_head wake_list; 753 #endif 754 755 #ifdef CONFIG_CPU_IDLE 756 /* Must be inspected within a rcu lock section */ 757 struct cpuidle_state *idle_state; 758 #endif 759 }; 760 761 static inline int cpu_of(struct rq *rq) 762 { 763 #ifdef CONFIG_SMP 764 return rq->cpu; 765 #else 766 return 0; 767 #endif 768 } 769 770 771 #ifdef CONFIG_SCHED_SMT 772 773 extern struct static_key_false sched_smt_present; 774 775 extern void __update_idle_core(struct rq *rq); 776 777 static inline void update_idle_core(struct rq *rq) 778 { 779 if (static_branch_unlikely(&sched_smt_present)) 780 __update_idle_core(rq); 781 } 782 783 #else 784 static inline void update_idle_core(struct rq *rq) { } 785 #endif 786 787 DECLARE_PER_CPU_SHARED_ALIGNED(struct rq, runqueues); 788 789 #define cpu_rq(cpu) (&per_cpu(runqueues, (cpu))) 790 #define this_rq() this_cpu_ptr(&runqueues) 791 #define task_rq(p) cpu_rq(task_cpu(p)) 792 #define cpu_curr(cpu) (cpu_rq(cpu)->curr) 793 #define raw_rq() raw_cpu_ptr(&runqueues) 794 795 static inline u64 __rq_clock_broken(struct rq *rq) 796 { 797 return READ_ONCE(rq->clock); 798 } 799 800 /* 801 * rq::clock_update_flags bits 802 * 803 * %RQCF_REQ_SKIP - will request skipping of clock update on the next 804 * call to __schedule(). This is an optimisation to avoid 805 * neighbouring rq clock updates. 806 * 807 * %RQCF_ACT_SKIP - is set from inside of __schedule() when skipping is 808 * in effect and calls to update_rq_clock() are being ignored. 809 * 810 * %RQCF_UPDATED - is a debug flag that indicates whether a call has been 811 * made to update_rq_clock() since the last time rq::lock was pinned. 812 * 813 * If inside of __schedule(), clock_update_flags will have been 814 * shifted left (a left shift is a cheap operation for the fast path 815 * to promote %RQCF_REQ_SKIP to %RQCF_ACT_SKIP), so you must use, 816 * 817 * if (rq-clock_update_flags >= RQCF_UPDATED) 818 * 819 * to check if %RQCF_UPADTED is set. It'll never be shifted more than 820 * one position though, because the next rq_unpin_lock() will shift it 821 * back. 822 */ 823 #define RQCF_REQ_SKIP 0x01 824 #define RQCF_ACT_SKIP 0x02 825 #define RQCF_UPDATED 0x04 826 827 static inline void assert_clock_updated(struct rq *rq) 828 { 829 /* 830 * The only reason for not seeing a clock update since the 831 * last rq_pin_lock() is if we're currently skipping updates. 832 */ 833 SCHED_WARN_ON(rq->clock_update_flags < RQCF_ACT_SKIP); 834 } 835 836 static inline u64 rq_clock(struct rq *rq) 837 { 838 lockdep_assert_held(&rq->lock); 839 assert_clock_updated(rq); 840 841 return rq->clock; 842 } 843 844 static inline u64 rq_clock_task(struct rq *rq) 845 { 846 lockdep_assert_held(&rq->lock); 847 assert_clock_updated(rq); 848 849 return rq->clock_task; 850 } 851 852 static inline void rq_clock_skip_update(struct rq *rq, bool skip) 853 { 854 lockdep_assert_held(&rq->lock); 855 if (skip) 856 rq->clock_update_flags |= RQCF_REQ_SKIP; 857 else 858 rq->clock_update_flags &= ~RQCF_REQ_SKIP; 859 } 860 861 struct rq_flags { 862 unsigned long flags; 863 struct pin_cookie cookie; 864 #ifdef CONFIG_SCHED_DEBUG 865 /* 866 * A copy of (rq::clock_update_flags & RQCF_UPDATED) for the 867 * current pin context is stashed here in case it needs to be 868 * restored in rq_repin_lock(). 869 */ 870 unsigned int clock_update_flags; 871 #endif 872 }; 873 874 static inline void rq_pin_lock(struct rq *rq, struct rq_flags *rf) 875 { 876 rf->cookie = lockdep_pin_lock(&rq->lock); 877 878 #ifdef CONFIG_SCHED_DEBUG 879 rq->clock_update_flags &= (RQCF_REQ_SKIP|RQCF_ACT_SKIP); 880 rf->clock_update_flags = 0; 881 #endif 882 } 883 884 static inline void rq_unpin_lock(struct rq *rq, struct rq_flags *rf) 885 { 886 #ifdef CONFIG_SCHED_DEBUG 887 if (rq->clock_update_flags > RQCF_ACT_SKIP) 888 rf->clock_update_flags = RQCF_UPDATED; 889 #endif 890 891 lockdep_unpin_lock(&rq->lock, rf->cookie); 892 } 893 894 static inline void rq_repin_lock(struct rq *rq, struct rq_flags *rf) 895 { 896 lockdep_repin_lock(&rq->lock, rf->cookie); 897 898 #ifdef CONFIG_SCHED_DEBUG 899 /* 900 * Restore the value we stashed in @rf for this pin context. 901 */ 902 rq->clock_update_flags |= rf->clock_update_flags; 903 #endif 904 } 905 906 #ifdef CONFIG_NUMA 907 enum numa_topology_type { 908 NUMA_DIRECT, 909 NUMA_GLUELESS_MESH, 910 NUMA_BACKPLANE, 911 }; 912 extern enum numa_topology_type sched_numa_topology_type; 913 extern int sched_max_numa_distance; 914 extern bool find_numa_distance(int distance); 915 #endif 916 917 #ifdef CONFIG_NUMA 918 extern void sched_init_numa(void); 919 extern void sched_domains_numa_masks_set(unsigned int cpu); 920 extern void sched_domains_numa_masks_clear(unsigned int cpu); 921 #else 922 static inline void sched_init_numa(void) { } 923 static inline void sched_domains_numa_masks_set(unsigned int cpu) { } 924 static inline void sched_domains_numa_masks_clear(unsigned int cpu) { } 925 #endif 926 927 #ifdef CONFIG_NUMA_BALANCING 928 /* The regions in numa_faults array from task_struct */ 929 enum numa_faults_stats { 930 NUMA_MEM = 0, 931 NUMA_CPU, 932 NUMA_MEMBUF, 933 NUMA_CPUBUF 934 }; 935 extern void sched_setnuma(struct task_struct *p, int node); 936 extern int migrate_task_to(struct task_struct *p, int cpu); 937 extern int migrate_swap(struct task_struct *, struct task_struct *); 938 #endif /* CONFIG_NUMA_BALANCING */ 939 940 #ifdef CONFIG_SMP 941 942 static inline void 943 queue_balance_callback(struct rq *rq, 944 struct callback_head *head, 945 void (*func)(struct rq *rq)) 946 { 947 lockdep_assert_held(&rq->lock); 948 949 if (unlikely(head->next)) 950 return; 951 952 head->func = (void (*)(struct callback_head *))func; 953 head->next = rq->balance_callback; 954 rq->balance_callback = head; 955 } 956 957 extern void sched_ttwu_pending(void); 958 959 #define rcu_dereference_check_sched_domain(p) \ 960 rcu_dereference_check((p), \ 961 lockdep_is_held(&sched_domains_mutex)) 962 963 /* 964 * The domain tree (rq->sd) is protected by RCU's quiescent state transition. 965 * See detach_destroy_domains: synchronize_sched for details. 966 * 967 * The domain tree of any CPU may only be accessed from within 968 * preempt-disabled sections. 969 */ 970 #define for_each_domain(cpu, __sd) \ 971 for (__sd = rcu_dereference_check_sched_domain(cpu_rq(cpu)->sd); \ 972 __sd; __sd = __sd->parent) 973 974 #define for_each_lower_domain(sd) for (; sd; sd = sd->child) 975 976 /** 977 * highest_flag_domain - Return highest sched_domain containing flag. 978 * @cpu: The cpu whose highest level of sched domain is to 979 * be returned. 980 * @flag: The flag to check for the highest sched_domain 981 * for the given cpu. 982 * 983 * Returns the highest sched_domain of a cpu which contains the given flag. 984 */ 985 static inline struct sched_domain *highest_flag_domain(int cpu, int flag) 986 { 987 struct sched_domain *sd, *hsd = NULL; 988 989 for_each_domain(cpu, sd) { 990 if (!(sd->flags & flag)) 991 break; 992 hsd = sd; 993 } 994 995 return hsd; 996 } 997 998 static inline struct sched_domain *lowest_flag_domain(int cpu, int flag) 999 { 1000 struct sched_domain *sd; 1001 1002 for_each_domain(cpu, sd) { 1003 if (sd->flags & flag) 1004 break; 1005 } 1006 1007 return sd; 1008 } 1009 1010 DECLARE_PER_CPU(struct sched_domain *, sd_llc); 1011 DECLARE_PER_CPU(int, sd_llc_size); 1012 DECLARE_PER_CPU(int, sd_llc_id); 1013 DECLARE_PER_CPU(struct sched_domain_shared *, sd_llc_shared); 1014 DECLARE_PER_CPU(struct sched_domain *, sd_numa); 1015 DECLARE_PER_CPU(struct sched_domain *, sd_asym); 1016 1017 struct sched_group_capacity { 1018 atomic_t ref; 1019 /* 1020 * CPU capacity of this group, SCHED_CAPACITY_SCALE being max capacity 1021 * for a single CPU. 1022 */ 1023 unsigned long capacity; 1024 unsigned long min_capacity; /* Min per-CPU capacity in group */ 1025 unsigned long next_update; 1026 int imbalance; /* XXX unrelated to capacity but shared group state */ 1027 1028 unsigned long cpumask[0]; /* iteration mask */ 1029 }; 1030 1031 struct sched_group { 1032 struct sched_group *next; /* Must be a circular list */ 1033 atomic_t ref; 1034 1035 unsigned int group_weight; 1036 struct sched_group_capacity *sgc; 1037 int asym_prefer_cpu; /* cpu of highest priority in group */ 1038 1039 /* 1040 * The CPUs this group covers. 1041 * 1042 * NOTE: this field is variable length. (Allocated dynamically 1043 * by attaching extra space to the end of the structure, 1044 * depending on how many CPUs the kernel has booted up with) 1045 */ 1046 unsigned long cpumask[0]; 1047 }; 1048 1049 static inline struct cpumask *sched_group_cpus(struct sched_group *sg) 1050 { 1051 return to_cpumask(sg->cpumask); 1052 } 1053 1054 /* 1055 * cpumask masking which cpus in the group are allowed to iterate up the domain 1056 * tree. 1057 */ 1058 static inline struct cpumask *sched_group_mask(struct sched_group *sg) 1059 { 1060 return to_cpumask(sg->sgc->cpumask); 1061 } 1062 1063 /** 1064 * group_first_cpu - Returns the first cpu in the cpumask of a sched_group. 1065 * @group: The group whose first cpu is to be returned. 1066 */ 1067 static inline unsigned int group_first_cpu(struct sched_group *group) 1068 { 1069 return cpumask_first(sched_group_cpus(group)); 1070 } 1071 1072 extern int group_balance_cpu(struct sched_group *sg); 1073 1074 #if defined(CONFIG_SCHED_DEBUG) && defined(CONFIG_SYSCTL) 1075 void register_sched_domain_sysctl(void); 1076 void unregister_sched_domain_sysctl(void); 1077 #else 1078 static inline void register_sched_domain_sysctl(void) 1079 { 1080 } 1081 static inline void unregister_sched_domain_sysctl(void) 1082 { 1083 } 1084 #endif 1085 1086 #else 1087 1088 static inline void sched_ttwu_pending(void) { } 1089 1090 #endif /* CONFIG_SMP */ 1091 1092 #include "stats.h" 1093 #include "autogroup.h" 1094 1095 #ifdef CONFIG_CGROUP_SCHED 1096 1097 /* 1098 * Return the group to which this tasks belongs. 1099 * 1100 * We cannot use task_css() and friends because the cgroup subsystem 1101 * changes that value before the cgroup_subsys::attach() method is called, 1102 * therefore we cannot pin it and might observe the wrong value. 1103 * 1104 * The same is true for autogroup's p->signal->autogroup->tg, the autogroup 1105 * core changes this before calling sched_move_task(). 1106 * 1107 * Instead we use a 'copy' which is updated from sched_move_task() while 1108 * holding both task_struct::pi_lock and rq::lock. 1109 */ 1110 static inline struct task_group *task_group(struct task_struct *p) 1111 { 1112 return p->sched_task_group; 1113 } 1114 1115 /* Change a task's cfs_rq and parent entity if it moves across CPUs/groups */ 1116 static inline void set_task_rq(struct task_struct *p, unsigned int cpu) 1117 { 1118 #if defined(CONFIG_FAIR_GROUP_SCHED) || defined(CONFIG_RT_GROUP_SCHED) 1119 struct task_group *tg = task_group(p); 1120 #endif 1121 1122 #ifdef CONFIG_FAIR_GROUP_SCHED 1123 set_task_rq_fair(&p->se, p->se.cfs_rq, tg->cfs_rq[cpu]); 1124 p->se.cfs_rq = tg->cfs_rq[cpu]; 1125 p->se.parent = tg->se[cpu]; 1126 #endif 1127 1128 #ifdef CONFIG_RT_GROUP_SCHED 1129 p->rt.rt_rq = tg->rt_rq[cpu]; 1130 p->rt.parent = tg->rt_se[cpu]; 1131 #endif 1132 } 1133 1134 #else /* CONFIG_CGROUP_SCHED */ 1135 1136 static inline void set_task_rq(struct task_struct *p, unsigned int cpu) { } 1137 static inline struct task_group *task_group(struct task_struct *p) 1138 { 1139 return NULL; 1140 } 1141 1142 #endif /* CONFIG_CGROUP_SCHED */ 1143 1144 static inline void __set_task_cpu(struct task_struct *p, unsigned int cpu) 1145 { 1146 set_task_rq(p, cpu); 1147 #ifdef CONFIG_SMP 1148 /* 1149 * After ->cpu is set up to a new value, task_rq_lock(p, ...) can be 1150 * successfuly executed on another CPU. We must ensure that updates of 1151 * per-task data have been completed by this moment. 1152 */ 1153 smp_wmb(); 1154 #ifdef CONFIG_THREAD_INFO_IN_TASK 1155 p->cpu = cpu; 1156 #else 1157 task_thread_info(p)->cpu = cpu; 1158 #endif 1159 p->wake_cpu = cpu; 1160 #endif 1161 } 1162 1163 /* 1164 * Tunables that become constants when CONFIG_SCHED_DEBUG is off: 1165 */ 1166 #ifdef CONFIG_SCHED_DEBUG 1167 # include <linux/static_key.h> 1168 # define const_debug __read_mostly 1169 #else 1170 # define const_debug const 1171 #endif 1172 1173 extern const_debug unsigned int sysctl_sched_features; 1174 1175 #define SCHED_FEAT(name, enabled) \ 1176 __SCHED_FEAT_##name , 1177 1178 enum { 1179 #include "features.h" 1180 __SCHED_FEAT_NR, 1181 }; 1182 1183 #undef SCHED_FEAT 1184 1185 #if defined(CONFIG_SCHED_DEBUG) && defined(HAVE_JUMP_LABEL) 1186 #define SCHED_FEAT(name, enabled) \ 1187 static __always_inline bool static_branch_##name(struct static_key *key) \ 1188 { \ 1189 return static_key_##enabled(key); \ 1190 } 1191 1192 #include "features.h" 1193 1194 #undef SCHED_FEAT 1195 1196 extern struct static_key sched_feat_keys[__SCHED_FEAT_NR]; 1197 #define sched_feat(x) (static_branch_##x(&sched_feat_keys[__SCHED_FEAT_##x])) 1198 #else /* !(SCHED_DEBUG && HAVE_JUMP_LABEL) */ 1199 #define sched_feat(x) (sysctl_sched_features & (1UL << __SCHED_FEAT_##x)) 1200 #endif /* SCHED_DEBUG && HAVE_JUMP_LABEL */ 1201 1202 extern struct static_key_false sched_numa_balancing; 1203 extern struct static_key_false sched_schedstats; 1204 1205 static inline u64 global_rt_period(void) 1206 { 1207 return (u64)sysctl_sched_rt_period * NSEC_PER_USEC; 1208 } 1209 1210 static inline u64 global_rt_runtime(void) 1211 { 1212 if (sysctl_sched_rt_runtime < 0) 1213 return RUNTIME_INF; 1214 1215 return (u64)sysctl_sched_rt_runtime * NSEC_PER_USEC; 1216 } 1217 1218 static inline int task_current(struct rq *rq, struct task_struct *p) 1219 { 1220 return rq->curr == p; 1221 } 1222 1223 static inline int task_running(struct rq *rq, struct task_struct *p) 1224 { 1225 #ifdef CONFIG_SMP 1226 return p->on_cpu; 1227 #else 1228 return task_current(rq, p); 1229 #endif 1230 } 1231 1232 static inline int task_on_rq_queued(struct task_struct *p) 1233 { 1234 return p->on_rq == TASK_ON_RQ_QUEUED; 1235 } 1236 1237 static inline int task_on_rq_migrating(struct task_struct *p) 1238 { 1239 return p->on_rq == TASK_ON_RQ_MIGRATING; 1240 } 1241 1242 #ifndef prepare_arch_switch 1243 # define prepare_arch_switch(next) do { } while (0) 1244 #endif 1245 #ifndef finish_arch_post_lock_switch 1246 # define finish_arch_post_lock_switch() do { } while (0) 1247 #endif 1248 1249 static inline void prepare_lock_switch(struct rq *rq, struct task_struct *next) 1250 { 1251 #ifdef CONFIG_SMP 1252 /* 1253 * We can optimise this out completely for !SMP, because the 1254 * SMP rebalancing from interrupt is the only thing that cares 1255 * here. 1256 */ 1257 next->on_cpu = 1; 1258 #endif 1259 } 1260 1261 static inline void finish_lock_switch(struct rq *rq, struct task_struct *prev) 1262 { 1263 #ifdef CONFIG_SMP 1264 /* 1265 * After ->on_cpu is cleared, the task can be moved to a different CPU. 1266 * We must ensure this doesn't happen until the switch is completely 1267 * finished. 1268 * 1269 * In particular, the load of prev->state in finish_task_switch() must 1270 * happen before this. 1271 * 1272 * Pairs with the smp_cond_load_acquire() in try_to_wake_up(). 1273 */ 1274 smp_store_release(&prev->on_cpu, 0); 1275 #endif 1276 #ifdef CONFIG_DEBUG_SPINLOCK 1277 /* this is a valid case when another task releases the spinlock */ 1278 rq->lock.owner = current; 1279 #endif 1280 /* 1281 * If we are tracking spinlock dependencies then we have to 1282 * fix up the runqueue lock - which gets 'carried over' from 1283 * prev into current: 1284 */ 1285 spin_acquire(&rq->lock.dep_map, 0, 0, _THIS_IP_); 1286 1287 raw_spin_unlock_irq(&rq->lock); 1288 } 1289 1290 /* 1291 * wake flags 1292 */ 1293 #define WF_SYNC 0x01 /* waker goes to sleep after wakeup */ 1294 #define WF_FORK 0x02 /* child wakeup after fork */ 1295 #define WF_MIGRATED 0x4 /* internal use, task got migrated */ 1296 1297 /* 1298 * To aid in avoiding the subversion of "niceness" due to uneven distribution 1299 * of tasks with abnormal "nice" values across CPUs the contribution that 1300 * each task makes to its run queue's load is weighted according to its 1301 * scheduling class and "nice" value. For SCHED_NORMAL tasks this is just a 1302 * scaled version of the new time slice allocation that they receive on time 1303 * slice expiry etc. 1304 */ 1305 1306 #define WEIGHT_IDLEPRIO 3 1307 #define WMULT_IDLEPRIO 1431655765 1308 1309 extern const int sched_prio_to_weight[40]; 1310 extern const u32 sched_prio_to_wmult[40]; 1311 1312 /* 1313 * {de,en}queue flags: 1314 * 1315 * DEQUEUE_SLEEP - task is no longer runnable 1316 * ENQUEUE_WAKEUP - task just became runnable 1317 * 1318 * SAVE/RESTORE - an otherwise spurious dequeue/enqueue, done to ensure tasks 1319 * are in a known state which allows modification. Such pairs 1320 * should preserve as much state as possible. 1321 * 1322 * MOVE - paired with SAVE/RESTORE, explicitly does not preserve the location 1323 * in the runqueue. 1324 * 1325 * ENQUEUE_HEAD - place at front of runqueue (tail if not specified) 1326 * ENQUEUE_REPLENISH - CBS (replenish runtime and postpone deadline) 1327 * ENQUEUE_MIGRATED - the task was migrated during wakeup 1328 * 1329 */ 1330 1331 #define DEQUEUE_SLEEP 0x01 1332 #define DEQUEUE_SAVE 0x02 /* matches ENQUEUE_RESTORE */ 1333 #define DEQUEUE_MOVE 0x04 /* matches ENQUEUE_MOVE */ 1334 1335 #define ENQUEUE_WAKEUP 0x01 1336 #define ENQUEUE_RESTORE 0x02 1337 #define ENQUEUE_MOVE 0x04 1338 1339 #define ENQUEUE_HEAD 0x08 1340 #define ENQUEUE_REPLENISH 0x10 1341 #ifdef CONFIG_SMP 1342 #define ENQUEUE_MIGRATED 0x20 1343 #else 1344 #define ENQUEUE_MIGRATED 0x00 1345 #endif 1346 1347 #define RETRY_TASK ((void *)-1UL) 1348 1349 struct sched_class { 1350 const struct sched_class *next; 1351 1352 void (*enqueue_task) (struct rq *rq, struct task_struct *p, int flags); 1353 void (*dequeue_task) (struct rq *rq, struct task_struct *p, int flags); 1354 void (*yield_task) (struct rq *rq); 1355 bool (*yield_to_task) (struct rq *rq, struct task_struct *p, bool preempt); 1356 1357 void (*check_preempt_curr) (struct rq *rq, struct task_struct *p, int flags); 1358 1359 /* 1360 * It is the responsibility of the pick_next_task() method that will 1361 * return the next task to call put_prev_task() on the @prev task or 1362 * something equivalent. 1363 * 1364 * May return RETRY_TASK when it finds a higher prio class has runnable 1365 * tasks. 1366 */ 1367 struct task_struct * (*pick_next_task) (struct rq *rq, 1368 struct task_struct *prev, 1369 struct rq_flags *rf); 1370 void (*put_prev_task) (struct rq *rq, struct task_struct *p); 1371 1372 #ifdef CONFIG_SMP 1373 int (*select_task_rq)(struct task_struct *p, int task_cpu, int sd_flag, int flags); 1374 void (*migrate_task_rq)(struct task_struct *p); 1375 1376 void (*task_woken) (struct rq *this_rq, struct task_struct *task); 1377 1378 void (*set_cpus_allowed)(struct task_struct *p, 1379 const struct cpumask *newmask); 1380 1381 void (*rq_online)(struct rq *rq); 1382 void (*rq_offline)(struct rq *rq); 1383 #endif 1384 1385 void (*set_curr_task) (struct rq *rq); 1386 void (*task_tick) (struct rq *rq, struct task_struct *p, int queued); 1387 void (*task_fork) (struct task_struct *p); 1388 void (*task_dead) (struct task_struct *p); 1389 1390 /* 1391 * The switched_from() call is allowed to drop rq->lock, therefore we 1392 * cannot assume the switched_from/switched_to pair is serliazed by 1393 * rq->lock. They are however serialized by p->pi_lock. 1394 */ 1395 void (*switched_from) (struct rq *this_rq, struct task_struct *task); 1396 void (*switched_to) (struct rq *this_rq, struct task_struct *task); 1397 void (*prio_changed) (struct rq *this_rq, struct task_struct *task, 1398 int oldprio); 1399 1400 unsigned int (*get_rr_interval) (struct rq *rq, 1401 struct task_struct *task); 1402 1403 void (*update_curr) (struct rq *rq); 1404 1405 #define TASK_SET_GROUP 0 1406 #define TASK_MOVE_GROUP 1 1407 1408 #ifdef CONFIG_FAIR_GROUP_SCHED 1409 void (*task_change_group) (struct task_struct *p, int type); 1410 #endif 1411 }; 1412 1413 static inline void put_prev_task(struct rq *rq, struct task_struct *prev) 1414 { 1415 prev->sched_class->put_prev_task(rq, prev); 1416 } 1417 1418 static inline void set_curr_task(struct rq *rq, struct task_struct *curr) 1419 { 1420 curr->sched_class->set_curr_task(rq); 1421 } 1422 1423 #define sched_class_highest (&stop_sched_class) 1424 #define for_each_class(class) \ 1425 for (class = sched_class_highest; class; class = class->next) 1426 1427 extern const struct sched_class stop_sched_class; 1428 extern const struct sched_class dl_sched_class; 1429 extern const struct sched_class rt_sched_class; 1430 extern const struct sched_class fair_sched_class; 1431 extern const struct sched_class idle_sched_class; 1432 1433 1434 #ifdef CONFIG_SMP 1435 1436 extern void update_group_capacity(struct sched_domain *sd, int cpu); 1437 1438 extern void trigger_load_balance(struct rq *rq); 1439 1440 extern void set_cpus_allowed_common(struct task_struct *p, const struct cpumask *new_mask); 1441 1442 #endif 1443 1444 #ifdef CONFIG_CPU_IDLE 1445 static inline void idle_set_state(struct rq *rq, 1446 struct cpuidle_state *idle_state) 1447 { 1448 rq->idle_state = idle_state; 1449 } 1450 1451 static inline struct cpuidle_state *idle_get_state(struct rq *rq) 1452 { 1453 SCHED_WARN_ON(!rcu_read_lock_held()); 1454 return rq->idle_state; 1455 } 1456 #else 1457 static inline void idle_set_state(struct rq *rq, 1458 struct cpuidle_state *idle_state) 1459 { 1460 } 1461 1462 static inline struct cpuidle_state *idle_get_state(struct rq *rq) 1463 { 1464 return NULL; 1465 } 1466 #endif 1467 1468 extern void sysrq_sched_debug_show(void); 1469 extern void sched_init_granularity(void); 1470 extern void update_max_interval(void); 1471 1472 extern void init_sched_dl_class(void); 1473 extern void init_sched_rt_class(void); 1474 extern void init_sched_fair_class(void); 1475 1476 extern void resched_curr(struct rq *rq); 1477 extern void resched_cpu(int cpu); 1478 1479 extern struct rt_bandwidth def_rt_bandwidth; 1480 extern void init_rt_bandwidth(struct rt_bandwidth *rt_b, u64 period, u64 runtime); 1481 1482 extern struct dl_bandwidth def_dl_bandwidth; 1483 extern void init_dl_bandwidth(struct dl_bandwidth *dl_b, u64 period, u64 runtime); 1484 extern void init_dl_task_timer(struct sched_dl_entity *dl_se); 1485 1486 unsigned long to_ratio(u64 period, u64 runtime); 1487 1488 extern void init_entity_runnable_average(struct sched_entity *se); 1489 extern void post_init_entity_util_avg(struct sched_entity *se); 1490 1491 #ifdef CONFIG_NO_HZ_FULL 1492 extern bool sched_can_stop_tick(struct rq *rq); 1493 1494 /* 1495 * Tick may be needed by tasks in the runqueue depending on their policy and 1496 * requirements. If tick is needed, lets send the target an IPI to kick it out of 1497 * nohz mode if necessary. 1498 */ 1499 static inline void sched_update_tick_dependency(struct rq *rq) 1500 { 1501 int cpu; 1502 1503 if (!tick_nohz_full_enabled()) 1504 return; 1505 1506 cpu = cpu_of(rq); 1507 1508 if (!tick_nohz_full_cpu(cpu)) 1509 return; 1510 1511 if (sched_can_stop_tick(rq)) 1512 tick_nohz_dep_clear_cpu(cpu, TICK_DEP_BIT_SCHED); 1513 else 1514 tick_nohz_dep_set_cpu(cpu, TICK_DEP_BIT_SCHED); 1515 } 1516 #else 1517 static inline void sched_update_tick_dependency(struct rq *rq) { } 1518 #endif 1519 1520 static inline void add_nr_running(struct rq *rq, unsigned count) 1521 { 1522 unsigned prev_nr = rq->nr_running; 1523 1524 rq->nr_running = prev_nr + count; 1525 1526 if (prev_nr < 2 && rq->nr_running >= 2) { 1527 #ifdef CONFIG_SMP 1528 if (!rq->rd->overload) 1529 rq->rd->overload = true; 1530 #endif 1531 } 1532 1533 sched_update_tick_dependency(rq); 1534 } 1535 1536 static inline void sub_nr_running(struct rq *rq, unsigned count) 1537 { 1538 rq->nr_running -= count; 1539 /* Check if we still need preemption */ 1540 sched_update_tick_dependency(rq); 1541 } 1542 1543 static inline void rq_last_tick_reset(struct rq *rq) 1544 { 1545 #ifdef CONFIG_NO_HZ_FULL 1546 rq->last_sched_tick = jiffies; 1547 #endif 1548 } 1549 1550 extern void update_rq_clock(struct rq *rq); 1551 1552 extern void activate_task(struct rq *rq, struct task_struct *p, int flags); 1553 extern void deactivate_task(struct rq *rq, struct task_struct *p, int flags); 1554 1555 extern void check_preempt_curr(struct rq *rq, struct task_struct *p, int flags); 1556 1557 extern const_debug unsigned int sysctl_sched_time_avg; 1558 extern const_debug unsigned int sysctl_sched_nr_migrate; 1559 extern const_debug unsigned int sysctl_sched_migration_cost; 1560 1561 static inline u64 sched_avg_period(void) 1562 { 1563 return (u64)sysctl_sched_time_avg * NSEC_PER_MSEC / 2; 1564 } 1565 1566 #ifdef CONFIG_SCHED_HRTICK 1567 1568 /* 1569 * Use hrtick when: 1570 * - enabled by features 1571 * - hrtimer is actually high res 1572 */ 1573 static inline int hrtick_enabled(struct rq *rq) 1574 { 1575 if (!sched_feat(HRTICK)) 1576 return 0; 1577 if (!cpu_active(cpu_of(rq))) 1578 return 0; 1579 return hrtimer_is_hres_active(&rq->hrtick_timer); 1580 } 1581 1582 void hrtick_start(struct rq *rq, u64 delay); 1583 1584 #else 1585 1586 static inline int hrtick_enabled(struct rq *rq) 1587 { 1588 return 0; 1589 } 1590 1591 #endif /* CONFIG_SCHED_HRTICK */ 1592 1593 #ifdef CONFIG_SMP 1594 extern void sched_avg_update(struct rq *rq); 1595 1596 #ifndef arch_scale_freq_capacity 1597 static __always_inline 1598 unsigned long arch_scale_freq_capacity(struct sched_domain *sd, int cpu) 1599 { 1600 return SCHED_CAPACITY_SCALE; 1601 } 1602 #endif 1603 1604 #ifndef arch_scale_cpu_capacity 1605 static __always_inline 1606 unsigned long arch_scale_cpu_capacity(struct sched_domain *sd, int cpu) 1607 { 1608 if (sd && (sd->flags & SD_SHARE_CPUCAPACITY) && (sd->span_weight > 1)) 1609 return sd->smt_gain / sd->span_weight; 1610 1611 return SCHED_CAPACITY_SCALE; 1612 } 1613 #endif 1614 1615 static inline void sched_rt_avg_update(struct rq *rq, u64 rt_delta) 1616 { 1617 rq->rt_avg += rt_delta * arch_scale_freq_capacity(NULL, cpu_of(rq)); 1618 sched_avg_update(rq); 1619 } 1620 #else 1621 static inline void sched_rt_avg_update(struct rq *rq, u64 rt_delta) { } 1622 static inline void sched_avg_update(struct rq *rq) { } 1623 #endif 1624 1625 struct rq *__task_rq_lock(struct task_struct *p, struct rq_flags *rf) 1626 __acquires(rq->lock); 1627 struct rq *task_rq_lock(struct task_struct *p, struct rq_flags *rf) 1628 __acquires(p->pi_lock) 1629 __acquires(rq->lock); 1630 1631 static inline void __task_rq_unlock(struct rq *rq, struct rq_flags *rf) 1632 __releases(rq->lock) 1633 { 1634 rq_unpin_lock(rq, rf); 1635 raw_spin_unlock(&rq->lock); 1636 } 1637 1638 static inline void 1639 task_rq_unlock(struct rq *rq, struct task_struct *p, struct rq_flags *rf) 1640 __releases(rq->lock) 1641 __releases(p->pi_lock) 1642 { 1643 rq_unpin_lock(rq, rf); 1644 raw_spin_unlock(&rq->lock); 1645 raw_spin_unlock_irqrestore(&p->pi_lock, rf->flags); 1646 } 1647 1648 #ifdef CONFIG_SMP 1649 #ifdef CONFIG_PREEMPT 1650 1651 static inline void double_rq_lock(struct rq *rq1, struct rq *rq2); 1652 1653 /* 1654 * fair double_lock_balance: Safely acquires both rq->locks in a fair 1655 * way at the expense of forcing extra atomic operations in all 1656 * invocations. This assures that the double_lock is acquired using the 1657 * same underlying policy as the spinlock_t on this architecture, which 1658 * reduces latency compared to the unfair variant below. However, it 1659 * also adds more overhead and therefore may reduce throughput. 1660 */ 1661 static inline int _double_lock_balance(struct rq *this_rq, struct rq *busiest) 1662 __releases(this_rq->lock) 1663 __acquires(busiest->lock) 1664 __acquires(this_rq->lock) 1665 { 1666 raw_spin_unlock(&this_rq->lock); 1667 double_rq_lock(this_rq, busiest); 1668 1669 return 1; 1670 } 1671 1672 #else 1673 /* 1674 * Unfair double_lock_balance: Optimizes throughput at the expense of 1675 * latency by eliminating extra atomic operations when the locks are 1676 * already in proper order on entry. This favors lower cpu-ids and will 1677 * grant the double lock to lower cpus over higher ids under contention, 1678 * regardless of entry order into the function. 1679 */ 1680 static inline int _double_lock_balance(struct rq *this_rq, struct rq *busiest) 1681 __releases(this_rq->lock) 1682 __acquires(busiest->lock) 1683 __acquires(this_rq->lock) 1684 { 1685 int ret = 0; 1686 1687 if (unlikely(!raw_spin_trylock(&busiest->lock))) { 1688 if (busiest < this_rq) { 1689 raw_spin_unlock(&this_rq->lock); 1690 raw_spin_lock(&busiest->lock); 1691 raw_spin_lock_nested(&this_rq->lock, 1692 SINGLE_DEPTH_NESTING); 1693 ret = 1; 1694 } else 1695 raw_spin_lock_nested(&busiest->lock, 1696 SINGLE_DEPTH_NESTING); 1697 } 1698 return ret; 1699 } 1700 1701 #endif /* CONFIG_PREEMPT */ 1702 1703 /* 1704 * double_lock_balance - lock the busiest runqueue, this_rq is locked already. 1705 */ 1706 static inline int double_lock_balance(struct rq *this_rq, struct rq *busiest) 1707 { 1708 if (unlikely(!irqs_disabled())) { 1709 /* printk() doesn't work good under rq->lock */ 1710 raw_spin_unlock(&this_rq->lock); 1711 BUG_ON(1); 1712 } 1713 1714 return _double_lock_balance(this_rq, busiest); 1715 } 1716 1717 static inline void double_unlock_balance(struct rq *this_rq, struct rq *busiest) 1718 __releases(busiest->lock) 1719 { 1720 raw_spin_unlock(&busiest->lock); 1721 lock_set_subclass(&this_rq->lock.dep_map, 0, _RET_IP_); 1722 } 1723 1724 static inline void double_lock(spinlock_t *l1, spinlock_t *l2) 1725 { 1726 if (l1 > l2) 1727 swap(l1, l2); 1728 1729 spin_lock(l1); 1730 spin_lock_nested(l2, SINGLE_DEPTH_NESTING); 1731 } 1732 1733 static inline void double_lock_irq(spinlock_t *l1, spinlock_t *l2) 1734 { 1735 if (l1 > l2) 1736 swap(l1, l2); 1737 1738 spin_lock_irq(l1); 1739 spin_lock_nested(l2, SINGLE_DEPTH_NESTING); 1740 } 1741 1742 static inline void double_raw_lock(raw_spinlock_t *l1, raw_spinlock_t *l2) 1743 { 1744 if (l1 > l2) 1745 swap(l1, l2); 1746 1747 raw_spin_lock(l1); 1748 raw_spin_lock_nested(l2, SINGLE_DEPTH_NESTING); 1749 } 1750 1751 /* 1752 * double_rq_lock - safely lock two runqueues 1753 * 1754 * Note this does not disable interrupts like task_rq_lock, 1755 * you need to do so manually before calling. 1756 */ 1757 static inline void double_rq_lock(struct rq *rq1, struct rq *rq2) 1758 __acquires(rq1->lock) 1759 __acquires(rq2->lock) 1760 { 1761 BUG_ON(!irqs_disabled()); 1762 if (rq1 == rq2) { 1763 raw_spin_lock(&rq1->lock); 1764 __acquire(rq2->lock); /* Fake it out ;) */ 1765 } else { 1766 if (rq1 < rq2) { 1767 raw_spin_lock(&rq1->lock); 1768 raw_spin_lock_nested(&rq2->lock, SINGLE_DEPTH_NESTING); 1769 } else { 1770 raw_spin_lock(&rq2->lock); 1771 raw_spin_lock_nested(&rq1->lock, SINGLE_DEPTH_NESTING); 1772 } 1773 } 1774 } 1775 1776 /* 1777 * double_rq_unlock - safely unlock two runqueues 1778 * 1779 * Note this does not restore interrupts like task_rq_unlock, 1780 * you need to do so manually after calling. 1781 */ 1782 static inline void double_rq_unlock(struct rq *rq1, struct rq *rq2) 1783 __releases(rq1->lock) 1784 __releases(rq2->lock) 1785 { 1786 raw_spin_unlock(&rq1->lock); 1787 if (rq1 != rq2) 1788 raw_spin_unlock(&rq2->lock); 1789 else 1790 __release(rq2->lock); 1791 } 1792 1793 extern void set_rq_online (struct rq *rq); 1794 extern void set_rq_offline(struct rq *rq); 1795 extern bool sched_smp_initialized; 1796 1797 #else /* CONFIG_SMP */ 1798 1799 /* 1800 * double_rq_lock - safely lock two runqueues 1801 * 1802 * Note this does not disable interrupts like task_rq_lock, 1803 * you need to do so manually before calling. 1804 */ 1805 static inline void double_rq_lock(struct rq *rq1, struct rq *rq2) 1806 __acquires(rq1->lock) 1807 __acquires(rq2->lock) 1808 { 1809 BUG_ON(!irqs_disabled()); 1810 BUG_ON(rq1 != rq2); 1811 raw_spin_lock(&rq1->lock); 1812 __acquire(rq2->lock); /* Fake it out ;) */ 1813 } 1814 1815 /* 1816 * double_rq_unlock - safely unlock two runqueues 1817 * 1818 * Note this does not restore interrupts like task_rq_unlock, 1819 * you need to do so manually after calling. 1820 */ 1821 static inline void double_rq_unlock(struct rq *rq1, struct rq *rq2) 1822 __releases(rq1->lock) 1823 __releases(rq2->lock) 1824 { 1825 BUG_ON(rq1 != rq2); 1826 raw_spin_unlock(&rq1->lock); 1827 __release(rq2->lock); 1828 } 1829 1830 #endif 1831 1832 extern struct sched_entity *__pick_first_entity(struct cfs_rq *cfs_rq); 1833 extern struct sched_entity *__pick_last_entity(struct cfs_rq *cfs_rq); 1834 1835 #ifdef CONFIG_SCHED_DEBUG 1836 extern void print_cfs_stats(struct seq_file *m, int cpu); 1837 extern void print_rt_stats(struct seq_file *m, int cpu); 1838 extern void print_dl_stats(struct seq_file *m, int cpu); 1839 extern void 1840 print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq); 1841 #ifdef CONFIG_NUMA_BALANCING 1842 extern void 1843 show_numa_stats(struct task_struct *p, struct seq_file *m); 1844 extern void 1845 print_numa_stats(struct seq_file *m, int node, unsigned long tsf, 1846 unsigned long tpf, unsigned long gsf, unsigned long gpf); 1847 #endif /* CONFIG_NUMA_BALANCING */ 1848 #endif /* CONFIG_SCHED_DEBUG */ 1849 1850 extern void init_cfs_rq(struct cfs_rq *cfs_rq); 1851 extern void init_rt_rq(struct rt_rq *rt_rq); 1852 extern void init_dl_rq(struct dl_rq *dl_rq); 1853 1854 extern void cfs_bandwidth_usage_inc(void); 1855 extern void cfs_bandwidth_usage_dec(void); 1856 1857 #ifdef CONFIG_NO_HZ_COMMON 1858 enum rq_nohz_flag_bits { 1859 NOHZ_TICK_STOPPED, 1860 NOHZ_BALANCE_KICK, 1861 }; 1862 1863 #define nohz_flags(cpu) (&cpu_rq(cpu)->nohz_flags) 1864 1865 extern void nohz_balance_exit_idle(unsigned int cpu); 1866 #else 1867 static inline void nohz_balance_exit_idle(unsigned int cpu) { } 1868 #endif 1869 1870 #ifdef CONFIG_IRQ_TIME_ACCOUNTING 1871 struct irqtime { 1872 u64 total; 1873 u64 tick_delta; 1874 u64 irq_start_time; 1875 struct u64_stats_sync sync; 1876 }; 1877 1878 DECLARE_PER_CPU(struct irqtime, cpu_irqtime); 1879 1880 /* 1881 * Returns the irqtime minus the softirq time computed by ksoftirqd. 1882 * Otherwise ksoftirqd's sum_exec_runtime is substracted its own runtime 1883 * and never move forward. 1884 */ 1885 static inline u64 irq_time_read(int cpu) 1886 { 1887 struct irqtime *irqtime = &per_cpu(cpu_irqtime, cpu); 1888 unsigned int seq; 1889 u64 total; 1890 1891 do { 1892 seq = __u64_stats_fetch_begin(&irqtime->sync); 1893 total = irqtime->total; 1894 } while (__u64_stats_fetch_retry(&irqtime->sync, seq)); 1895 1896 return total; 1897 } 1898 #endif /* CONFIG_IRQ_TIME_ACCOUNTING */ 1899 1900 #ifdef CONFIG_CPU_FREQ 1901 DECLARE_PER_CPU(struct update_util_data *, cpufreq_update_util_data); 1902 1903 /** 1904 * cpufreq_update_util - Take a note about CPU utilization changes. 1905 * @rq: Runqueue to carry out the update for. 1906 * @flags: Update reason flags. 1907 * 1908 * This function is called by the scheduler on the CPU whose utilization is 1909 * being updated. 1910 * 1911 * It can only be called from RCU-sched read-side critical sections. 1912 * 1913 * The way cpufreq is currently arranged requires it to evaluate the CPU 1914 * performance state (frequency/voltage) on a regular basis to prevent it from 1915 * being stuck in a completely inadequate performance level for too long. 1916 * That is not guaranteed to happen if the updates are only triggered from CFS, 1917 * though, because they may not be coming in if RT or deadline tasks are active 1918 * all the time (or there are RT and DL tasks only). 1919 * 1920 * As a workaround for that issue, this function is called by the RT and DL 1921 * sched classes to trigger extra cpufreq updates to prevent it from stalling, 1922 * but that really is a band-aid. Going forward it should be replaced with 1923 * solutions targeted more specifically at RT and DL tasks. 1924 */ 1925 static inline void cpufreq_update_util(struct rq *rq, unsigned int flags) 1926 { 1927 struct update_util_data *data; 1928 1929 data = rcu_dereference_sched(*this_cpu_ptr(&cpufreq_update_util_data)); 1930 if (data) 1931 data->func(data, rq_clock(rq), flags); 1932 } 1933 1934 static inline void cpufreq_update_this_cpu(struct rq *rq, unsigned int flags) 1935 { 1936 if (cpu_of(rq) == smp_processor_id()) 1937 cpufreq_update_util(rq, flags); 1938 } 1939 #else 1940 static inline void cpufreq_update_util(struct rq *rq, unsigned int flags) {} 1941 static inline void cpufreq_update_this_cpu(struct rq *rq, unsigned int flags) {} 1942 #endif /* CONFIG_CPU_FREQ */ 1943 1944 #ifdef arch_scale_freq_capacity 1945 #ifndef arch_scale_freq_invariant 1946 #define arch_scale_freq_invariant() (true) 1947 #endif 1948 #else /* arch_scale_freq_capacity */ 1949 #define arch_scale_freq_invariant() (false) 1950 #endif 1951