1 /* SPDX-License-Identifier: GPL-2.0 */ 2 3 #include <linux/sched.h> 4 #include <linux/sched/autogroup.h> 5 #include <linux/sched/sysctl.h> 6 #include <linux/sched/topology.h> 7 #include <linux/sched/rt.h> 8 #include <linux/sched/deadline.h> 9 #include <linux/sched/clock.h> 10 #include <linux/sched/wake_q.h> 11 #include <linux/sched/signal.h> 12 #include <linux/sched/numa_balancing.h> 13 #include <linux/sched/mm.h> 14 #include <linux/sched/cpufreq.h> 15 #include <linux/sched/stat.h> 16 #include <linux/sched/nohz.h> 17 #include <linux/sched/debug.h> 18 #include <linux/sched/hotplug.h> 19 #include <linux/sched/task.h> 20 #include <linux/sched/task_stack.h> 21 #include <linux/sched/cputime.h> 22 #include <linux/sched/init.h> 23 24 #include <linux/u64_stats_sync.h> 25 #include <linux/kernel_stat.h> 26 #include <linux/binfmts.h> 27 #include <linux/mutex.h> 28 #include <linux/spinlock.h> 29 #include <linux/stop_machine.h> 30 #include <linux/irq_work.h> 31 #include <linux/tick.h> 32 #include <linux/slab.h> 33 #include <linux/cgroup.h> 34 35 #ifdef CONFIG_PARAVIRT 36 #include <asm/paravirt.h> 37 #endif 38 39 #include "cpupri.h" 40 #include "cpudeadline.h" 41 42 #ifdef CONFIG_SCHED_DEBUG 43 # define SCHED_WARN_ON(x) WARN_ONCE(x, #x) 44 #else 45 # define SCHED_WARN_ON(x) ({ (void)(x), 0; }) 46 #endif 47 48 struct rq; 49 struct cpuidle_state; 50 51 /* task_struct::on_rq states: */ 52 #define TASK_ON_RQ_QUEUED 1 53 #define TASK_ON_RQ_MIGRATING 2 54 55 extern __read_mostly int scheduler_running; 56 57 extern unsigned long calc_load_update; 58 extern atomic_long_t calc_load_tasks; 59 60 extern void calc_global_load_tick(struct rq *this_rq); 61 extern long calc_load_fold_active(struct rq *this_rq, long adjust); 62 63 #ifdef CONFIG_SMP 64 extern void cpu_load_update_active(struct rq *this_rq); 65 #else 66 static inline void cpu_load_update_active(struct rq *this_rq) { } 67 #endif 68 69 /* 70 * Helpers for converting nanosecond timing to jiffy resolution 71 */ 72 #define NS_TO_JIFFIES(TIME) ((unsigned long)(TIME) / (NSEC_PER_SEC / HZ)) 73 74 /* 75 * Increase resolution of nice-level calculations for 64-bit architectures. 76 * The extra resolution improves shares distribution and load balancing of 77 * low-weight task groups (eg. nice +19 on an autogroup), deeper taskgroup 78 * hierarchies, especially on larger systems. This is not a user-visible change 79 * and does not change the user-interface for setting shares/weights. 80 * 81 * We increase resolution only if we have enough bits to allow this increased 82 * resolution (i.e. 64bit). The costs for increasing resolution when 32bit are 83 * pretty high and the returns do not justify the increased costs. 84 * 85 * Really only required when CONFIG_FAIR_GROUP_SCHED is also set, but to 86 * increase coverage and consistency always enable it on 64bit platforms. 87 */ 88 #ifdef CONFIG_64BIT 89 # define NICE_0_LOAD_SHIFT (SCHED_FIXEDPOINT_SHIFT + SCHED_FIXEDPOINT_SHIFT) 90 # define scale_load(w) ((w) << SCHED_FIXEDPOINT_SHIFT) 91 # define scale_load_down(w) ((w) >> SCHED_FIXEDPOINT_SHIFT) 92 #else 93 # define NICE_0_LOAD_SHIFT (SCHED_FIXEDPOINT_SHIFT) 94 # define scale_load(w) (w) 95 # define scale_load_down(w) (w) 96 #endif 97 98 /* 99 * Task weight (visible to users) and its load (invisible to users) have 100 * independent resolution, but they should be well calibrated. We use 101 * scale_load() and scale_load_down(w) to convert between them. The 102 * following must be true: 103 * 104 * scale_load(sched_prio_to_weight[USER_PRIO(NICE_TO_PRIO(0))]) == NICE_0_LOAD 105 * 106 */ 107 #define NICE_0_LOAD (1L << NICE_0_LOAD_SHIFT) 108 109 /* 110 * Single value that decides SCHED_DEADLINE internal math precision. 111 * 10 -> just above 1us 112 * 9 -> just above 0.5us 113 */ 114 #define DL_SCALE (10) 115 116 /* 117 * These are the 'tuning knobs' of the scheduler: 118 */ 119 120 /* 121 * single value that denotes runtime == period, ie unlimited time. 122 */ 123 #define RUNTIME_INF ((u64)~0ULL) 124 125 static inline int idle_policy(int policy) 126 { 127 return policy == SCHED_IDLE; 128 } 129 static inline int fair_policy(int policy) 130 { 131 return policy == SCHED_NORMAL || policy == SCHED_BATCH; 132 } 133 134 static inline int rt_policy(int policy) 135 { 136 return policy == SCHED_FIFO || policy == SCHED_RR; 137 } 138 139 static inline int dl_policy(int policy) 140 { 141 return policy == SCHED_DEADLINE; 142 } 143 static inline bool valid_policy(int policy) 144 { 145 return idle_policy(policy) || fair_policy(policy) || 146 rt_policy(policy) || dl_policy(policy); 147 } 148 149 static inline int task_has_rt_policy(struct task_struct *p) 150 { 151 return rt_policy(p->policy); 152 } 153 154 static inline int task_has_dl_policy(struct task_struct *p) 155 { 156 return dl_policy(p->policy); 157 } 158 159 /* 160 * Tells if entity @a should preempt entity @b. 161 */ 162 static inline bool 163 dl_entity_preempt(struct sched_dl_entity *a, struct sched_dl_entity *b) 164 { 165 return dl_time_before(a->deadline, b->deadline); 166 } 167 168 /* 169 * This is the priority-queue data structure of the RT scheduling class: 170 */ 171 struct rt_prio_array { 172 DECLARE_BITMAP(bitmap, MAX_RT_PRIO+1); /* include 1 bit for delimiter */ 173 struct list_head queue[MAX_RT_PRIO]; 174 }; 175 176 struct rt_bandwidth { 177 /* nests inside the rq lock: */ 178 raw_spinlock_t rt_runtime_lock; 179 ktime_t rt_period; 180 u64 rt_runtime; 181 struct hrtimer rt_period_timer; 182 unsigned int rt_period_active; 183 }; 184 185 void __dl_clear_params(struct task_struct *p); 186 187 /* 188 * To keep the bandwidth of -deadline tasks and groups under control 189 * we need some place where: 190 * - store the maximum -deadline bandwidth of the system (the group); 191 * - cache the fraction of that bandwidth that is currently allocated. 192 * 193 * This is all done in the data structure below. It is similar to the 194 * one used for RT-throttling (rt_bandwidth), with the main difference 195 * that, since here we are only interested in admission control, we 196 * do not decrease any runtime while the group "executes", neither we 197 * need a timer to replenish it. 198 * 199 * With respect to SMP, the bandwidth is given on a per-CPU basis, 200 * meaning that: 201 * - dl_bw (< 100%) is the bandwidth of the system (group) on each CPU; 202 * - dl_total_bw array contains, in the i-eth element, the currently 203 * allocated bandwidth on the i-eth CPU. 204 * Moreover, groups consume bandwidth on each CPU, while tasks only 205 * consume bandwidth on the CPU they're running on. 206 * Finally, dl_total_bw_cpu is used to cache the index of dl_total_bw 207 * that will be shown the next time the proc or cgroup controls will 208 * be red. It on its turn can be changed by writing on its own 209 * control. 210 */ 211 struct dl_bandwidth { 212 raw_spinlock_t dl_runtime_lock; 213 u64 dl_runtime; 214 u64 dl_period; 215 }; 216 217 static inline int dl_bandwidth_enabled(void) 218 { 219 return sysctl_sched_rt_runtime >= 0; 220 } 221 222 struct dl_bw { 223 raw_spinlock_t lock; 224 u64 bw, total_bw; 225 }; 226 227 static inline void __dl_update(struct dl_bw *dl_b, s64 bw); 228 229 static inline 230 void __dl_sub(struct dl_bw *dl_b, u64 tsk_bw, int cpus) 231 { 232 dl_b->total_bw -= tsk_bw; 233 __dl_update(dl_b, (s32)tsk_bw / cpus); 234 } 235 236 static inline 237 void __dl_add(struct dl_bw *dl_b, u64 tsk_bw, int cpus) 238 { 239 dl_b->total_bw += tsk_bw; 240 __dl_update(dl_b, -((s32)tsk_bw / cpus)); 241 } 242 243 static inline 244 bool __dl_overflow(struct dl_bw *dl_b, int cpus, u64 old_bw, u64 new_bw) 245 { 246 return dl_b->bw != -1 && 247 dl_b->bw * cpus < dl_b->total_bw - old_bw + new_bw; 248 } 249 250 void dl_change_utilization(struct task_struct *p, u64 new_bw); 251 extern void init_dl_bw(struct dl_bw *dl_b); 252 extern int sched_dl_global_validate(void); 253 extern void sched_dl_do_global(void); 254 extern int sched_dl_overflow(struct task_struct *p, int policy, 255 const struct sched_attr *attr); 256 extern void __setparam_dl(struct task_struct *p, const struct sched_attr *attr); 257 extern void __getparam_dl(struct task_struct *p, struct sched_attr *attr); 258 extern bool __checkparam_dl(const struct sched_attr *attr); 259 extern bool dl_param_changed(struct task_struct *p, const struct sched_attr *attr); 260 extern int dl_task_can_attach(struct task_struct *p, 261 const struct cpumask *cs_cpus_allowed); 262 extern int dl_cpuset_cpumask_can_shrink(const struct cpumask *cur, 263 const struct cpumask *trial); 264 extern bool dl_cpu_busy(unsigned int cpu); 265 266 #ifdef CONFIG_CGROUP_SCHED 267 268 #include <linux/cgroup.h> 269 270 struct cfs_rq; 271 struct rt_rq; 272 273 extern struct list_head task_groups; 274 275 struct cfs_bandwidth { 276 #ifdef CONFIG_CFS_BANDWIDTH 277 raw_spinlock_t lock; 278 ktime_t period; 279 u64 quota, runtime; 280 s64 hierarchical_quota; 281 u64 runtime_expires; 282 283 int idle, period_active; 284 struct hrtimer period_timer, slack_timer; 285 struct list_head throttled_cfs_rq; 286 287 /* statistics */ 288 int nr_periods, nr_throttled; 289 u64 throttled_time; 290 #endif 291 }; 292 293 /* task group related information */ 294 struct task_group { 295 struct cgroup_subsys_state css; 296 297 #ifdef CONFIG_FAIR_GROUP_SCHED 298 /* schedulable entities of this group on each cpu */ 299 struct sched_entity **se; 300 /* runqueue "owned" by this group on each cpu */ 301 struct cfs_rq **cfs_rq; 302 unsigned long shares; 303 304 #ifdef CONFIG_SMP 305 /* 306 * load_avg can be heavily contended at clock tick time, so put 307 * it in its own cacheline separated from the fields above which 308 * will also be accessed at each tick. 309 */ 310 atomic_long_t load_avg ____cacheline_aligned; 311 #endif 312 #endif 313 314 #ifdef CONFIG_RT_GROUP_SCHED 315 struct sched_rt_entity **rt_se; 316 struct rt_rq **rt_rq; 317 318 struct rt_bandwidth rt_bandwidth; 319 #endif 320 321 struct rcu_head rcu; 322 struct list_head list; 323 324 struct task_group *parent; 325 struct list_head siblings; 326 struct list_head children; 327 328 #ifdef CONFIG_SCHED_AUTOGROUP 329 struct autogroup *autogroup; 330 #endif 331 332 struct cfs_bandwidth cfs_bandwidth; 333 }; 334 335 #ifdef CONFIG_FAIR_GROUP_SCHED 336 #define ROOT_TASK_GROUP_LOAD NICE_0_LOAD 337 338 /* 339 * A weight of 0 or 1 can cause arithmetics problems. 340 * A weight of a cfs_rq is the sum of weights of which entities 341 * are queued on this cfs_rq, so a weight of a entity should not be 342 * too large, so as the shares value of a task group. 343 * (The default weight is 1024 - so there's no practical 344 * limitation from this.) 345 */ 346 #define MIN_SHARES (1UL << 1) 347 #define MAX_SHARES (1UL << 18) 348 #endif 349 350 typedef int (*tg_visitor)(struct task_group *, void *); 351 352 extern int walk_tg_tree_from(struct task_group *from, 353 tg_visitor down, tg_visitor up, void *data); 354 355 /* 356 * Iterate the full tree, calling @down when first entering a node and @up when 357 * leaving it for the final time. 358 * 359 * Caller must hold rcu_lock or sufficient equivalent. 360 */ 361 static inline int walk_tg_tree(tg_visitor down, tg_visitor up, void *data) 362 { 363 return walk_tg_tree_from(&root_task_group, down, up, data); 364 } 365 366 extern int tg_nop(struct task_group *tg, void *data); 367 368 extern void free_fair_sched_group(struct task_group *tg); 369 extern int alloc_fair_sched_group(struct task_group *tg, struct task_group *parent); 370 extern void online_fair_sched_group(struct task_group *tg); 371 extern void unregister_fair_sched_group(struct task_group *tg); 372 extern void init_tg_cfs_entry(struct task_group *tg, struct cfs_rq *cfs_rq, 373 struct sched_entity *se, int cpu, 374 struct sched_entity *parent); 375 extern void init_cfs_bandwidth(struct cfs_bandwidth *cfs_b); 376 377 extern void __refill_cfs_bandwidth_runtime(struct cfs_bandwidth *cfs_b); 378 extern void start_cfs_bandwidth(struct cfs_bandwidth *cfs_b); 379 extern void unthrottle_cfs_rq(struct cfs_rq *cfs_rq); 380 381 extern void free_rt_sched_group(struct task_group *tg); 382 extern int alloc_rt_sched_group(struct task_group *tg, struct task_group *parent); 383 extern void init_tg_rt_entry(struct task_group *tg, struct rt_rq *rt_rq, 384 struct sched_rt_entity *rt_se, int cpu, 385 struct sched_rt_entity *parent); 386 extern int sched_group_set_rt_runtime(struct task_group *tg, long rt_runtime_us); 387 extern int sched_group_set_rt_period(struct task_group *tg, u64 rt_period_us); 388 extern long sched_group_rt_runtime(struct task_group *tg); 389 extern long sched_group_rt_period(struct task_group *tg); 390 extern int sched_rt_can_attach(struct task_group *tg, struct task_struct *tsk); 391 392 extern struct task_group *sched_create_group(struct task_group *parent); 393 extern void sched_online_group(struct task_group *tg, 394 struct task_group *parent); 395 extern void sched_destroy_group(struct task_group *tg); 396 extern void sched_offline_group(struct task_group *tg); 397 398 extern void sched_move_task(struct task_struct *tsk); 399 400 #ifdef CONFIG_FAIR_GROUP_SCHED 401 extern int sched_group_set_shares(struct task_group *tg, unsigned long shares); 402 403 #ifdef CONFIG_SMP 404 extern void set_task_rq_fair(struct sched_entity *se, 405 struct cfs_rq *prev, struct cfs_rq *next); 406 #else /* !CONFIG_SMP */ 407 static inline void set_task_rq_fair(struct sched_entity *se, 408 struct cfs_rq *prev, struct cfs_rq *next) { } 409 #endif /* CONFIG_SMP */ 410 #endif /* CONFIG_FAIR_GROUP_SCHED */ 411 412 #else /* CONFIG_CGROUP_SCHED */ 413 414 struct cfs_bandwidth { }; 415 416 #endif /* CONFIG_CGROUP_SCHED */ 417 418 /* CFS-related fields in a runqueue */ 419 struct cfs_rq { 420 struct load_weight load; 421 unsigned long runnable_weight; 422 unsigned int nr_running, h_nr_running; 423 424 u64 exec_clock; 425 u64 min_vruntime; 426 #ifndef CONFIG_64BIT 427 u64 min_vruntime_copy; 428 #endif 429 430 struct rb_root_cached tasks_timeline; 431 432 /* 433 * 'curr' points to currently running entity on this cfs_rq. 434 * It is set to NULL otherwise (i.e when none are currently running). 435 */ 436 struct sched_entity *curr, *next, *last, *skip; 437 438 #ifdef CONFIG_SCHED_DEBUG 439 unsigned int nr_spread_over; 440 #endif 441 442 #ifdef CONFIG_SMP 443 /* 444 * CFS load tracking 445 */ 446 struct sched_avg avg; 447 #ifndef CONFIG_64BIT 448 u64 load_last_update_time_copy; 449 #endif 450 struct { 451 raw_spinlock_t lock ____cacheline_aligned; 452 int nr; 453 unsigned long load_avg; 454 unsigned long util_avg; 455 unsigned long runnable_sum; 456 } removed; 457 458 #ifdef CONFIG_FAIR_GROUP_SCHED 459 unsigned long tg_load_avg_contrib; 460 long propagate; 461 long prop_runnable_sum; 462 463 /* 464 * h_load = weight * f(tg) 465 * 466 * Where f(tg) is the recursive weight fraction assigned to 467 * this group. 468 */ 469 unsigned long h_load; 470 u64 last_h_load_update; 471 struct sched_entity *h_load_next; 472 #endif /* CONFIG_FAIR_GROUP_SCHED */ 473 #endif /* CONFIG_SMP */ 474 475 #ifdef CONFIG_FAIR_GROUP_SCHED 476 struct rq *rq; /* cpu runqueue to which this cfs_rq is attached */ 477 478 /* 479 * leaf cfs_rqs are those that hold tasks (lowest schedulable entity in 480 * a hierarchy). Non-leaf lrqs hold other higher schedulable entities 481 * (like users, containers etc.) 482 * 483 * leaf_cfs_rq_list ties together list of leaf cfs_rq's in a cpu. This 484 * list is used during load balance. 485 */ 486 int on_list; 487 struct list_head leaf_cfs_rq_list; 488 struct task_group *tg; /* group that "owns" this runqueue */ 489 490 #ifdef CONFIG_CFS_BANDWIDTH 491 int runtime_enabled; 492 u64 runtime_expires; 493 s64 runtime_remaining; 494 495 u64 throttled_clock, throttled_clock_task; 496 u64 throttled_clock_task_time; 497 int throttled, throttle_count; 498 struct list_head throttled_list; 499 #endif /* CONFIG_CFS_BANDWIDTH */ 500 #endif /* CONFIG_FAIR_GROUP_SCHED */ 501 }; 502 503 static inline int rt_bandwidth_enabled(void) 504 { 505 return sysctl_sched_rt_runtime >= 0; 506 } 507 508 /* RT IPI pull logic requires IRQ_WORK */ 509 #if defined(CONFIG_IRQ_WORK) && defined(CONFIG_SMP) 510 # define HAVE_RT_PUSH_IPI 511 #endif 512 513 /* Real-Time classes' related field in a runqueue: */ 514 struct rt_rq { 515 struct rt_prio_array active; 516 unsigned int rt_nr_running; 517 unsigned int rr_nr_running; 518 #if defined CONFIG_SMP || defined CONFIG_RT_GROUP_SCHED 519 struct { 520 int curr; /* highest queued rt task prio */ 521 #ifdef CONFIG_SMP 522 int next; /* next highest */ 523 #endif 524 } highest_prio; 525 #endif 526 #ifdef CONFIG_SMP 527 unsigned long rt_nr_migratory; 528 unsigned long rt_nr_total; 529 int overloaded; 530 struct plist_head pushable_tasks; 531 #endif /* CONFIG_SMP */ 532 int rt_queued; 533 534 int rt_throttled; 535 u64 rt_time; 536 u64 rt_runtime; 537 /* Nests inside the rq lock: */ 538 raw_spinlock_t rt_runtime_lock; 539 540 #ifdef CONFIG_RT_GROUP_SCHED 541 unsigned long rt_nr_boosted; 542 543 struct rq *rq; 544 struct task_group *tg; 545 #endif 546 }; 547 548 /* Deadline class' related fields in a runqueue */ 549 struct dl_rq { 550 /* runqueue is an rbtree, ordered by deadline */ 551 struct rb_root_cached root; 552 553 unsigned long dl_nr_running; 554 555 #ifdef CONFIG_SMP 556 /* 557 * Deadline values of the currently executing and the 558 * earliest ready task on this rq. Caching these facilitates 559 * the decision wether or not a ready but not running task 560 * should migrate somewhere else. 561 */ 562 struct { 563 u64 curr; 564 u64 next; 565 } earliest_dl; 566 567 unsigned long dl_nr_migratory; 568 int overloaded; 569 570 /* 571 * Tasks on this rq that can be pushed away. They are kept in 572 * an rb-tree, ordered by tasks' deadlines, with caching 573 * of the leftmost (earliest deadline) element. 574 */ 575 struct rb_root_cached pushable_dl_tasks_root; 576 #else 577 struct dl_bw dl_bw; 578 #endif 579 /* 580 * "Active utilization" for this runqueue: increased when a 581 * task wakes up (becomes TASK_RUNNING) and decreased when a 582 * task blocks 583 */ 584 u64 running_bw; 585 586 /* 587 * Utilization of the tasks "assigned" to this runqueue (including 588 * the tasks that are in runqueue and the tasks that executed on this 589 * CPU and blocked). Increased when a task moves to this runqueue, and 590 * decreased when the task moves away (migrates, changes scheduling 591 * policy, or terminates). 592 * This is needed to compute the "inactive utilization" for the 593 * runqueue (inactive utilization = this_bw - running_bw). 594 */ 595 u64 this_bw; 596 u64 extra_bw; 597 598 /* 599 * Inverse of the fraction of CPU utilization that can be reclaimed 600 * by the GRUB algorithm. 601 */ 602 u64 bw_ratio; 603 }; 604 605 #ifdef CONFIG_SMP 606 607 static inline bool sched_asym_prefer(int a, int b) 608 { 609 return arch_asym_cpu_priority(a) > arch_asym_cpu_priority(b); 610 } 611 612 /* 613 * We add the notion of a root-domain which will be used to define per-domain 614 * variables. Each exclusive cpuset essentially defines an island domain by 615 * fully partitioning the member cpus from any other cpuset. Whenever a new 616 * exclusive cpuset is created, we also create and attach a new root-domain 617 * object. 618 * 619 */ 620 struct root_domain { 621 atomic_t refcount; 622 atomic_t rto_count; 623 struct rcu_head rcu; 624 cpumask_var_t span; 625 cpumask_var_t online; 626 627 /* Indicate more than one runnable task for any CPU */ 628 bool overload; 629 630 /* 631 * The bit corresponding to a CPU gets set here if such CPU has more 632 * than one runnable -deadline task (as it is below for RT tasks). 633 */ 634 cpumask_var_t dlo_mask; 635 atomic_t dlo_count; 636 struct dl_bw dl_bw; 637 struct cpudl cpudl; 638 639 #ifdef HAVE_RT_PUSH_IPI 640 /* 641 * For IPI pull requests, loop across the rto_mask. 642 */ 643 struct irq_work rto_push_work; 644 raw_spinlock_t rto_lock; 645 /* These are only updated and read within rto_lock */ 646 int rto_loop; 647 int rto_cpu; 648 /* These atomics are updated outside of a lock */ 649 atomic_t rto_loop_next; 650 atomic_t rto_loop_start; 651 #endif 652 /* 653 * The "RT overload" flag: it gets set if a CPU has more than 654 * one runnable RT task. 655 */ 656 cpumask_var_t rto_mask; 657 struct cpupri cpupri; 658 659 unsigned long max_cpu_capacity; 660 }; 661 662 extern struct root_domain def_root_domain; 663 extern struct mutex sched_domains_mutex; 664 665 extern void init_defrootdomain(void); 666 extern int sched_init_domains(const struct cpumask *cpu_map); 667 extern void rq_attach_root(struct rq *rq, struct root_domain *rd); 668 669 #ifdef HAVE_RT_PUSH_IPI 670 extern void rto_push_irq_work_func(struct irq_work *work); 671 #endif 672 #endif /* CONFIG_SMP */ 673 674 /* 675 * This is the main, per-CPU runqueue data structure. 676 * 677 * Locking rule: those places that want to lock multiple runqueues 678 * (such as the load balancing or the thread migration code), lock 679 * acquire operations must be ordered by ascending &runqueue. 680 */ 681 struct rq { 682 /* runqueue lock: */ 683 raw_spinlock_t lock; 684 685 /* 686 * nr_running and cpu_load should be in the same cacheline because 687 * remote CPUs use both these fields when doing load calculation. 688 */ 689 unsigned int nr_running; 690 #ifdef CONFIG_NUMA_BALANCING 691 unsigned int nr_numa_running; 692 unsigned int nr_preferred_running; 693 #endif 694 #define CPU_LOAD_IDX_MAX 5 695 unsigned long cpu_load[CPU_LOAD_IDX_MAX]; 696 #ifdef CONFIG_NO_HZ_COMMON 697 #ifdef CONFIG_SMP 698 unsigned long last_load_update_tick; 699 #endif /* CONFIG_SMP */ 700 unsigned long nohz_flags; 701 #endif /* CONFIG_NO_HZ_COMMON */ 702 #ifdef CONFIG_NO_HZ_FULL 703 unsigned long last_sched_tick; 704 #endif 705 /* capture load from *all* tasks on this cpu: */ 706 struct load_weight load; 707 unsigned long nr_load_updates; 708 u64 nr_switches; 709 710 struct cfs_rq cfs; 711 struct rt_rq rt; 712 struct dl_rq dl; 713 714 #ifdef CONFIG_FAIR_GROUP_SCHED 715 /* list of leaf cfs_rq on this cpu: */ 716 struct list_head leaf_cfs_rq_list; 717 struct list_head *tmp_alone_branch; 718 #endif /* CONFIG_FAIR_GROUP_SCHED */ 719 720 /* 721 * This is part of a global counter where only the total sum 722 * over all CPUs matters. A task can increase this counter on 723 * one CPU and if it got migrated afterwards it may decrease 724 * it on another CPU. Always updated under the runqueue lock: 725 */ 726 unsigned long nr_uninterruptible; 727 728 struct task_struct *curr, *idle, *stop; 729 unsigned long next_balance; 730 struct mm_struct *prev_mm; 731 732 unsigned int clock_update_flags; 733 u64 clock; 734 u64 clock_task; 735 736 atomic_t nr_iowait; 737 738 #ifdef CONFIG_SMP 739 struct root_domain *rd; 740 struct sched_domain *sd; 741 742 unsigned long cpu_capacity; 743 unsigned long cpu_capacity_orig; 744 745 struct callback_head *balance_callback; 746 747 unsigned char idle_balance; 748 /* For active balancing */ 749 int active_balance; 750 int push_cpu; 751 struct cpu_stop_work active_balance_work; 752 /* cpu of this runqueue: */ 753 int cpu; 754 int online; 755 756 struct list_head cfs_tasks; 757 758 u64 rt_avg; 759 u64 age_stamp; 760 u64 idle_stamp; 761 u64 avg_idle; 762 763 /* This is used to determine avg_idle's max value */ 764 u64 max_idle_balance_cost; 765 #endif 766 767 #ifdef CONFIG_IRQ_TIME_ACCOUNTING 768 u64 prev_irq_time; 769 #endif 770 #ifdef CONFIG_PARAVIRT 771 u64 prev_steal_time; 772 #endif 773 #ifdef CONFIG_PARAVIRT_TIME_ACCOUNTING 774 u64 prev_steal_time_rq; 775 #endif 776 777 /* calc_load related fields */ 778 unsigned long calc_load_update; 779 long calc_load_active; 780 781 #ifdef CONFIG_SCHED_HRTICK 782 #ifdef CONFIG_SMP 783 int hrtick_csd_pending; 784 call_single_data_t hrtick_csd; 785 #endif 786 struct hrtimer hrtick_timer; 787 #endif 788 789 #ifdef CONFIG_SCHEDSTATS 790 /* latency stats */ 791 struct sched_info rq_sched_info; 792 unsigned long long rq_cpu_time; 793 /* could above be rq->cfs_rq.exec_clock + rq->rt_rq.rt_runtime ? */ 794 795 /* sys_sched_yield() stats */ 796 unsigned int yld_count; 797 798 /* schedule() stats */ 799 unsigned int sched_count; 800 unsigned int sched_goidle; 801 802 /* try_to_wake_up() stats */ 803 unsigned int ttwu_count; 804 unsigned int ttwu_local; 805 #endif 806 807 #ifdef CONFIG_SMP 808 struct llist_head wake_list; 809 #endif 810 811 #ifdef CONFIG_CPU_IDLE 812 /* Must be inspected within a rcu lock section */ 813 struct cpuidle_state *idle_state; 814 #endif 815 }; 816 817 static inline int cpu_of(struct rq *rq) 818 { 819 #ifdef CONFIG_SMP 820 return rq->cpu; 821 #else 822 return 0; 823 #endif 824 } 825 826 827 #ifdef CONFIG_SCHED_SMT 828 829 extern struct static_key_false sched_smt_present; 830 831 extern void __update_idle_core(struct rq *rq); 832 833 static inline void update_idle_core(struct rq *rq) 834 { 835 if (static_branch_unlikely(&sched_smt_present)) 836 __update_idle_core(rq); 837 } 838 839 #else 840 static inline void update_idle_core(struct rq *rq) { } 841 #endif 842 843 DECLARE_PER_CPU_SHARED_ALIGNED(struct rq, runqueues); 844 845 #define cpu_rq(cpu) (&per_cpu(runqueues, (cpu))) 846 #define this_rq() this_cpu_ptr(&runqueues) 847 #define task_rq(p) cpu_rq(task_cpu(p)) 848 #define cpu_curr(cpu) (cpu_rq(cpu)->curr) 849 #define raw_rq() raw_cpu_ptr(&runqueues) 850 851 static inline u64 __rq_clock_broken(struct rq *rq) 852 { 853 return READ_ONCE(rq->clock); 854 } 855 856 /* 857 * rq::clock_update_flags bits 858 * 859 * %RQCF_REQ_SKIP - will request skipping of clock update on the next 860 * call to __schedule(). This is an optimisation to avoid 861 * neighbouring rq clock updates. 862 * 863 * %RQCF_ACT_SKIP - is set from inside of __schedule() when skipping is 864 * in effect and calls to update_rq_clock() are being ignored. 865 * 866 * %RQCF_UPDATED - is a debug flag that indicates whether a call has been 867 * made to update_rq_clock() since the last time rq::lock was pinned. 868 * 869 * If inside of __schedule(), clock_update_flags will have been 870 * shifted left (a left shift is a cheap operation for the fast path 871 * to promote %RQCF_REQ_SKIP to %RQCF_ACT_SKIP), so you must use, 872 * 873 * if (rq-clock_update_flags >= RQCF_UPDATED) 874 * 875 * to check if %RQCF_UPADTED is set. It'll never be shifted more than 876 * one position though, because the next rq_unpin_lock() will shift it 877 * back. 878 */ 879 #define RQCF_REQ_SKIP 0x01 880 #define RQCF_ACT_SKIP 0x02 881 #define RQCF_UPDATED 0x04 882 883 static inline void assert_clock_updated(struct rq *rq) 884 { 885 /* 886 * The only reason for not seeing a clock update since the 887 * last rq_pin_lock() is if we're currently skipping updates. 888 */ 889 SCHED_WARN_ON(rq->clock_update_flags < RQCF_ACT_SKIP); 890 } 891 892 static inline u64 rq_clock(struct rq *rq) 893 { 894 lockdep_assert_held(&rq->lock); 895 assert_clock_updated(rq); 896 897 return rq->clock; 898 } 899 900 static inline u64 rq_clock_task(struct rq *rq) 901 { 902 lockdep_assert_held(&rq->lock); 903 assert_clock_updated(rq); 904 905 return rq->clock_task; 906 } 907 908 static inline void rq_clock_skip_update(struct rq *rq, bool skip) 909 { 910 lockdep_assert_held(&rq->lock); 911 if (skip) 912 rq->clock_update_flags |= RQCF_REQ_SKIP; 913 else 914 rq->clock_update_flags &= ~RQCF_REQ_SKIP; 915 } 916 917 struct rq_flags { 918 unsigned long flags; 919 struct pin_cookie cookie; 920 #ifdef CONFIG_SCHED_DEBUG 921 /* 922 * A copy of (rq::clock_update_flags & RQCF_UPDATED) for the 923 * current pin context is stashed here in case it needs to be 924 * restored in rq_repin_lock(). 925 */ 926 unsigned int clock_update_flags; 927 #endif 928 }; 929 930 static inline void rq_pin_lock(struct rq *rq, struct rq_flags *rf) 931 { 932 rf->cookie = lockdep_pin_lock(&rq->lock); 933 934 #ifdef CONFIG_SCHED_DEBUG 935 rq->clock_update_flags &= (RQCF_REQ_SKIP|RQCF_ACT_SKIP); 936 rf->clock_update_flags = 0; 937 #endif 938 } 939 940 static inline void rq_unpin_lock(struct rq *rq, struct rq_flags *rf) 941 { 942 #ifdef CONFIG_SCHED_DEBUG 943 if (rq->clock_update_flags > RQCF_ACT_SKIP) 944 rf->clock_update_flags = RQCF_UPDATED; 945 #endif 946 947 lockdep_unpin_lock(&rq->lock, rf->cookie); 948 } 949 950 static inline void rq_repin_lock(struct rq *rq, struct rq_flags *rf) 951 { 952 lockdep_repin_lock(&rq->lock, rf->cookie); 953 954 #ifdef CONFIG_SCHED_DEBUG 955 /* 956 * Restore the value we stashed in @rf for this pin context. 957 */ 958 rq->clock_update_flags |= rf->clock_update_flags; 959 #endif 960 } 961 962 #ifdef CONFIG_NUMA 963 enum numa_topology_type { 964 NUMA_DIRECT, 965 NUMA_GLUELESS_MESH, 966 NUMA_BACKPLANE, 967 }; 968 extern enum numa_topology_type sched_numa_topology_type; 969 extern int sched_max_numa_distance; 970 extern bool find_numa_distance(int distance); 971 #endif 972 973 #ifdef CONFIG_NUMA 974 extern void sched_init_numa(void); 975 extern void sched_domains_numa_masks_set(unsigned int cpu); 976 extern void sched_domains_numa_masks_clear(unsigned int cpu); 977 #else 978 static inline void sched_init_numa(void) { } 979 static inline void sched_domains_numa_masks_set(unsigned int cpu) { } 980 static inline void sched_domains_numa_masks_clear(unsigned int cpu) { } 981 #endif 982 983 #ifdef CONFIG_NUMA_BALANCING 984 /* The regions in numa_faults array from task_struct */ 985 enum numa_faults_stats { 986 NUMA_MEM = 0, 987 NUMA_CPU, 988 NUMA_MEMBUF, 989 NUMA_CPUBUF 990 }; 991 extern void sched_setnuma(struct task_struct *p, int node); 992 extern int migrate_task_to(struct task_struct *p, int cpu); 993 extern int migrate_swap(struct task_struct *, struct task_struct *); 994 #endif /* CONFIG_NUMA_BALANCING */ 995 996 #ifdef CONFIG_SMP 997 998 static inline void 999 queue_balance_callback(struct rq *rq, 1000 struct callback_head *head, 1001 void (*func)(struct rq *rq)) 1002 { 1003 lockdep_assert_held(&rq->lock); 1004 1005 if (unlikely(head->next)) 1006 return; 1007 1008 head->func = (void (*)(struct callback_head *))func; 1009 head->next = rq->balance_callback; 1010 rq->balance_callback = head; 1011 } 1012 1013 extern void sched_ttwu_pending(void); 1014 1015 #define rcu_dereference_check_sched_domain(p) \ 1016 rcu_dereference_check((p), \ 1017 lockdep_is_held(&sched_domains_mutex)) 1018 1019 /* 1020 * The domain tree (rq->sd) is protected by RCU's quiescent state transition. 1021 * See detach_destroy_domains: synchronize_sched for details. 1022 * 1023 * The domain tree of any CPU may only be accessed from within 1024 * preempt-disabled sections. 1025 */ 1026 #define for_each_domain(cpu, __sd) \ 1027 for (__sd = rcu_dereference_check_sched_domain(cpu_rq(cpu)->sd); \ 1028 __sd; __sd = __sd->parent) 1029 1030 #define for_each_lower_domain(sd) for (; sd; sd = sd->child) 1031 1032 /** 1033 * highest_flag_domain - Return highest sched_domain containing flag. 1034 * @cpu: The cpu whose highest level of sched domain is to 1035 * be returned. 1036 * @flag: The flag to check for the highest sched_domain 1037 * for the given cpu. 1038 * 1039 * Returns the highest sched_domain of a cpu which contains the given flag. 1040 */ 1041 static inline struct sched_domain *highest_flag_domain(int cpu, int flag) 1042 { 1043 struct sched_domain *sd, *hsd = NULL; 1044 1045 for_each_domain(cpu, sd) { 1046 if (!(sd->flags & flag)) 1047 break; 1048 hsd = sd; 1049 } 1050 1051 return hsd; 1052 } 1053 1054 static inline struct sched_domain *lowest_flag_domain(int cpu, int flag) 1055 { 1056 struct sched_domain *sd; 1057 1058 for_each_domain(cpu, sd) { 1059 if (sd->flags & flag) 1060 break; 1061 } 1062 1063 return sd; 1064 } 1065 1066 DECLARE_PER_CPU(struct sched_domain *, sd_llc); 1067 DECLARE_PER_CPU(int, sd_llc_size); 1068 DECLARE_PER_CPU(int, sd_llc_id); 1069 DECLARE_PER_CPU(struct sched_domain_shared *, sd_llc_shared); 1070 DECLARE_PER_CPU(struct sched_domain *, sd_numa); 1071 DECLARE_PER_CPU(struct sched_domain *, sd_asym); 1072 1073 struct sched_group_capacity { 1074 atomic_t ref; 1075 /* 1076 * CPU capacity of this group, SCHED_CAPACITY_SCALE being max capacity 1077 * for a single CPU. 1078 */ 1079 unsigned long capacity; 1080 unsigned long min_capacity; /* Min per-CPU capacity in group */ 1081 unsigned long next_update; 1082 int imbalance; /* XXX unrelated to capacity but shared group state */ 1083 1084 #ifdef CONFIG_SCHED_DEBUG 1085 int id; 1086 #endif 1087 1088 unsigned long cpumask[0]; /* balance mask */ 1089 }; 1090 1091 struct sched_group { 1092 struct sched_group *next; /* Must be a circular list */ 1093 atomic_t ref; 1094 1095 unsigned int group_weight; 1096 struct sched_group_capacity *sgc; 1097 int asym_prefer_cpu; /* cpu of highest priority in group */ 1098 1099 /* 1100 * The CPUs this group covers. 1101 * 1102 * NOTE: this field is variable length. (Allocated dynamically 1103 * by attaching extra space to the end of the structure, 1104 * depending on how many CPUs the kernel has booted up with) 1105 */ 1106 unsigned long cpumask[0]; 1107 }; 1108 1109 static inline struct cpumask *sched_group_span(struct sched_group *sg) 1110 { 1111 return to_cpumask(sg->cpumask); 1112 } 1113 1114 /* 1115 * See build_balance_mask(). 1116 */ 1117 static inline struct cpumask *group_balance_mask(struct sched_group *sg) 1118 { 1119 return to_cpumask(sg->sgc->cpumask); 1120 } 1121 1122 /** 1123 * group_first_cpu - Returns the first cpu in the cpumask of a sched_group. 1124 * @group: The group whose first cpu is to be returned. 1125 */ 1126 static inline unsigned int group_first_cpu(struct sched_group *group) 1127 { 1128 return cpumask_first(sched_group_span(group)); 1129 } 1130 1131 extern int group_balance_cpu(struct sched_group *sg); 1132 1133 #if defined(CONFIG_SCHED_DEBUG) && defined(CONFIG_SYSCTL) 1134 void register_sched_domain_sysctl(void); 1135 void dirty_sched_domain_sysctl(int cpu); 1136 void unregister_sched_domain_sysctl(void); 1137 #else 1138 static inline void register_sched_domain_sysctl(void) 1139 { 1140 } 1141 static inline void dirty_sched_domain_sysctl(int cpu) 1142 { 1143 } 1144 static inline void unregister_sched_domain_sysctl(void) 1145 { 1146 } 1147 #endif 1148 1149 #else 1150 1151 static inline void sched_ttwu_pending(void) { } 1152 1153 #endif /* CONFIG_SMP */ 1154 1155 #include "stats.h" 1156 #include "autogroup.h" 1157 1158 #ifdef CONFIG_CGROUP_SCHED 1159 1160 /* 1161 * Return the group to which this tasks belongs. 1162 * 1163 * We cannot use task_css() and friends because the cgroup subsystem 1164 * changes that value before the cgroup_subsys::attach() method is called, 1165 * therefore we cannot pin it and might observe the wrong value. 1166 * 1167 * The same is true for autogroup's p->signal->autogroup->tg, the autogroup 1168 * core changes this before calling sched_move_task(). 1169 * 1170 * Instead we use a 'copy' which is updated from sched_move_task() while 1171 * holding both task_struct::pi_lock and rq::lock. 1172 */ 1173 static inline struct task_group *task_group(struct task_struct *p) 1174 { 1175 return p->sched_task_group; 1176 } 1177 1178 /* Change a task's cfs_rq and parent entity if it moves across CPUs/groups */ 1179 static inline void set_task_rq(struct task_struct *p, unsigned int cpu) 1180 { 1181 #if defined(CONFIG_FAIR_GROUP_SCHED) || defined(CONFIG_RT_GROUP_SCHED) 1182 struct task_group *tg = task_group(p); 1183 #endif 1184 1185 #ifdef CONFIG_FAIR_GROUP_SCHED 1186 set_task_rq_fair(&p->se, p->se.cfs_rq, tg->cfs_rq[cpu]); 1187 p->se.cfs_rq = tg->cfs_rq[cpu]; 1188 p->se.parent = tg->se[cpu]; 1189 #endif 1190 1191 #ifdef CONFIG_RT_GROUP_SCHED 1192 p->rt.rt_rq = tg->rt_rq[cpu]; 1193 p->rt.parent = tg->rt_se[cpu]; 1194 #endif 1195 } 1196 1197 #else /* CONFIG_CGROUP_SCHED */ 1198 1199 static inline void set_task_rq(struct task_struct *p, unsigned int cpu) { } 1200 static inline struct task_group *task_group(struct task_struct *p) 1201 { 1202 return NULL; 1203 } 1204 1205 #endif /* CONFIG_CGROUP_SCHED */ 1206 1207 static inline void __set_task_cpu(struct task_struct *p, unsigned int cpu) 1208 { 1209 set_task_rq(p, cpu); 1210 #ifdef CONFIG_SMP 1211 /* 1212 * After ->cpu is set up to a new value, task_rq_lock(p, ...) can be 1213 * successfuly executed on another CPU. We must ensure that updates of 1214 * per-task data have been completed by this moment. 1215 */ 1216 smp_wmb(); 1217 #ifdef CONFIG_THREAD_INFO_IN_TASK 1218 p->cpu = cpu; 1219 #else 1220 task_thread_info(p)->cpu = cpu; 1221 #endif 1222 p->wake_cpu = cpu; 1223 #endif 1224 } 1225 1226 /* 1227 * Tunables that become constants when CONFIG_SCHED_DEBUG is off: 1228 */ 1229 #ifdef CONFIG_SCHED_DEBUG 1230 # include <linux/static_key.h> 1231 # define const_debug __read_mostly 1232 #else 1233 # define const_debug const 1234 #endif 1235 1236 #define SCHED_FEAT(name, enabled) \ 1237 __SCHED_FEAT_##name , 1238 1239 enum { 1240 #include "features.h" 1241 __SCHED_FEAT_NR, 1242 }; 1243 1244 #undef SCHED_FEAT 1245 1246 #if defined(CONFIG_SCHED_DEBUG) && defined(HAVE_JUMP_LABEL) 1247 1248 /* 1249 * To support run-time toggling of sched features, all the translation units 1250 * (but core.c) reference the sysctl_sched_features defined in core.c. 1251 */ 1252 extern const_debug unsigned int sysctl_sched_features; 1253 1254 #define SCHED_FEAT(name, enabled) \ 1255 static __always_inline bool static_branch_##name(struct static_key *key) \ 1256 { \ 1257 return static_key_##enabled(key); \ 1258 } 1259 1260 #include "features.h" 1261 #undef SCHED_FEAT 1262 1263 extern struct static_key sched_feat_keys[__SCHED_FEAT_NR]; 1264 #define sched_feat(x) (static_branch_##x(&sched_feat_keys[__SCHED_FEAT_##x])) 1265 1266 #else /* !(SCHED_DEBUG && HAVE_JUMP_LABEL) */ 1267 1268 /* 1269 * Each translation unit has its own copy of sysctl_sched_features to allow 1270 * constants propagation at compile time and compiler optimization based on 1271 * features default. 1272 */ 1273 #define SCHED_FEAT(name, enabled) \ 1274 (1UL << __SCHED_FEAT_##name) * enabled | 1275 static const_debug __maybe_unused unsigned int sysctl_sched_features = 1276 #include "features.h" 1277 0; 1278 #undef SCHED_FEAT 1279 1280 #define sched_feat(x) (sysctl_sched_features & (1UL << __SCHED_FEAT_##x)) 1281 1282 #endif /* SCHED_DEBUG && HAVE_JUMP_LABEL */ 1283 1284 extern struct static_key_false sched_numa_balancing; 1285 extern struct static_key_false sched_schedstats; 1286 1287 static inline u64 global_rt_period(void) 1288 { 1289 return (u64)sysctl_sched_rt_period * NSEC_PER_USEC; 1290 } 1291 1292 static inline u64 global_rt_runtime(void) 1293 { 1294 if (sysctl_sched_rt_runtime < 0) 1295 return RUNTIME_INF; 1296 1297 return (u64)sysctl_sched_rt_runtime * NSEC_PER_USEC; 1298 } 1299 1300 static inline int task_current(struct rq *rq, struct task_struct *p) 1301 { 1302 return rq->curr == p; 1303 } 1304 1305 static inline int task_running(struct rq *rq, struct task_struct *p) 1306 { 1307 #ifdef CONFIG_SMP 1308 return p->on_cpu; 1309 #else 1310 return task_current(rq, p); 1311 #endif 1312 } 1313 1314 static inline int task_on_rq_queued(struct task_struct *p) 1315 { 1316 return p->on_rq == TASK_ON_RQ_QUEUED; 1317 } 1318 1319 static inline int task_on_rq_migrating(struct task_struct *p) 1320 { 1321 return p->on_rq == TASK_ON_RQ_MIGRATING; 1322 } 1323 1324 #ifndef prepare_arch_switch 1325 # define prepare_arch_switch(next) do { } while (0) 1326 #endif 1327 #ifndef finish_arch_post_lock_switch 1328 # define finish_arch_post_lock_switch() do { } while (0) 1329 #endif 1330 1331 static inline void prepare_lock_switch(struct rq *rq, struct task_struct *next) 1332 { 1333 #ifdef CONFIG_SMP 1334 /* 1335 * We can optimise this out completely for !SMP, because the 1336 * SMP rebalancing from interrupt is the only thing that cares 1337 * here. 1338 */ 1339 next->on_cpu = 1; 1340 #endif 1341 } 1342 1343 static inline void finish_lock_switch(struct rq *rq, struct task_struct *prev) 1344 { 1345 #ifdef CONFIG_SMP 1346 /* 1347 * After ->on_cpu is cleared, the task can be moved to a different CPU. 1348 * We must ensure this doesn't happen until the switch is completely 1349 * finished. 1350 * 1351 * In particular, the load of prev->state in finish_task_switch() must 1352 * happen before this. 1353 * 1354 * Pairs with the smp_cond_load_acquire() in try_to_wake_up(). 1355 */ 1356 smp_store_release(&prev->on_cpu, 0); 1357 #endif 1358 #ifdef CONFIG_DEBUG_SPINLOCK 1359 /* this is a valid case when another task releases the spinlock */ 1360 rq->lock.owner = current; 1361 #endif 1362 /* 1363 * If we are tracking spinlock dependencies then we have to 1364 * fix up the runqueue lock - which gets 'carried over' from 1365 * prev into current: 1366 */ 1367 spin_acquire(&rq->lock.dep_map, 0, 0, _THIS_IP_); 1368 1369 raw_spin_unlock_irq(&rq->lock); 1370 } 1371 1372 /* 1373 * wake flags 1374 */ 1375 #define WF_SYNC 0x01 /* waker goes to sleep after wakeup */ 1376 #define WF_FORK 0x02 /* child wakeup after fork */ 1377 #define WF_MIGRATED 0x4 /* internal use, task got migrated */ 1378 1379 /* 1380 * To aid in avoiding the subversion of "niceness" due to uneven distribution 1381 * of tasks with abnormal "nice" values across CPUs the contribution that 1382 * each task makes to its run queue's load is weighted according to its 1383 * scheduling class and "nice" value. For SCHED_NORMAL tasks this is just a 1384 * scaled version of the new time slice allocation that they receive on time 1385 * slice expiry etc. 1386 */ 1387 1388 #define WEIGHT_IDLEPRIO 3 1389 #define WMULT_IDLEPRIO 1431655765 1390 1391 extern const int sched_prio_to_weight[40]; 1392 extern const u32 sched_prio_to_wmult[40]; 1393 1394 /* 1395 * {de,en}queue flags: 1396 * 1397 * DEQUEUE_SLEEP - task is no longer runnable 1398 * ENQUEUE_WAKEUP - task just became runnable 1399 * 1400 * SAVE/RESTORE - an otherwise spurious dequeue/enqueue, done to ensure tasks 1401 * are in a known state which allows modification. Such pairs 1402 * should preserve as much state as possible. 1403 * 1404 * MOVE - paired with SAVE/RESTORE, explicitly does not preserve the location 1405 * in the runqueue. 1406 * 1407 * ENQUEUE_HEAD - place at front of runqueue (tail if not specified) 1408 * ENQUEUE_REPLENISH - CBS (replenish runtime and postpone deadline) 1409 * ENQUEUE_MIGRATED - the task was migrated during wakeup 1410 * 1411 */ 1412 1413 #define DEQUEUE_SLEEP 0x01 1414 #define DEQUEUE_SAVE 0x02 /* matches ENQUEUE_RESTORE */ 1415 #define DEQUEUE_MOVE 0x04 /* matches ENQUEUE_MOVE */ 1416 #define DEQUEUE_NOCLOCK 0x08 /* matches ENQUEUE_NOCLOCK */ 1417 1418 #define ENQUEUE_WAKEUP 0x01 1419 #define ENQUEUE_RESTORE 0x02 1420 #define ENQUEUE_MOVE 0x04 1421 #define ENQUEUE_NOCLOCK 0x08 1422 1423 #define ENQUEUE_HEAD 0x10 1424 #define ENQUEUE_REPLENISH 0x20 1425 #ifdef CONFIG_SMP 1426 #define ENQUEUE_MIGRATED 0x40 1427 #else 1428 #define ENQUEUE_MIGRATED 0x00 1429 #endif 1430 1431 #define RETRY_TASK ((void *)-1UL) 1432 1433 struct sched_class { 1434 const struct sched_class *next; 1435 1436 void (*enqueue_task) (struct rq *rq, struct task_struct *p, int flags); 1437 void (*dequeue_task) (struct rq *rq, struct task_struct *p, int flags); 1438 void (*yield_task) (struct rq *rq); 1439 bool (*yield_to_task) (struct rq *rq, struct task_struct *p, bool preempt); 1440 1441 void (*check_preempt_curr) (struct rq *rq, struct task_struct *p, int flags); 1442 1443 /* 1444 * It is the responsibility of the pick_next_task() method that will 1445 * return the next task to call put_prev_task() on the @prev task or 1446 * something equivalent. 1447 * 1448 * May return RETRY_TASK when it finds a higher prio class has runnable 1449 * tasks. 1450 */ 1451 struct task_struct * (*pick_next_task) (struct rq *rq, 1452 struct task_struct *prev, 1453 struct rq_flags *rf); 1454 void (*put_prev_task) (struct rq *rq, struct task_struct *p); 1455 1456 #ifdef CONFIG_SMP 1457 int (*select_task_rq)(struct task_struct *p, int task_cpu, int sd_flag, int flags); 1458 void (*migrate_task_rq)(struct task_struct *p); 1459 1460 void (*task_woken) (struct rq *this_rq, struct task_struct *task); 1461 1462 void (*set_cpus_allowed)(struct task_struct *p, 1463 const struct cpumask *newmask); 1464 1465 void (*rq_online)(struct rq *rq); 1466 void (*rq_offline)(struct rq *rq); 1467 #endif 1468 1469 void (*set_curr_task) (struct rq *rq); 1470 void (*task_tick) (struct rq *rq, struct task_struct *p, int queued); 1471 void (*task_fork) (struct task_struct *p); 1472 void (*task_dead) (struct task_struct *p); 1473 1474 /* 1475 * The switched_from() call is allowed to drop rq->lock, therefore we 1476 * cannot assume the switched_from/switched_to pair is serliazed by 1477 * rq->lock. They are however serialized by p->pi_lock. 1478 */ 1479 void (*switched_from) (struct rq *this_rq, struct task_struct *task); 1480 void (*switched_to) (struct rq *this_rq, struct task_struct *task); 1481 void (*prio_changed) (struct rq *this_rq, struct task_struct *task, 1482 int oldprio); 1483 1484 unsigned int (*get_rr_interval) (struct rq *rq, 1485 struct task_struct *task); 1486 1487 void (*update_curr) (struct rq *rq); 1488 1489 #define TASK_SET_GROUP 0 1490 #define TASK_MOVE_GROUP 1 1491 1492 #ifdef CONFIG_FAIR_GROUP_SCHED 1493 void (*task_change_group) (struct task_struct *p, int type); 1494 #endif 1495 }; 1496 1497 static inline void put_prev_task(struct rq *rq, struct task_struct *prev) 1498 { 1499 prev->sched_class->put_prev_task(rq, prev); 1500 } 1501 1502 static inline void set_curr_task(struct rq *rq, struct task_struct *curr) 1503 { 1504 curr->sched_class->set_curr_task(rq); 1505 } 1506 1507 #ifdef CONFIG_SMP 1508 #define sched_class_highest (&stop_sched_class) 1509 #else 1510 #define sched_class_highest (&dl_sched_class) 1511 #endif 1512 #define for_each_class(class) \ 1513 for (class = sched_class_highest; class; class = class->next) 1514 1515 extern const struct sched_class stop_sched_class; 1516 extern const struct sched_class dl_sched_class; 1517 extern const struct sched_class rt_sched_class; 1518 extern const struct sched_class fair_sched_class; 1519 extern const struct sched_class idle_sched_class; 1520 1521 1522 #ifdef CONFIG_SMP 1523 1524 extern void update_group_capacity(struct sched_domain *sd, int cpu); 1525 1526 extern void trigger_load_balance(struct rq *rq); 1527 1528 extern void set_cpus_allowed_common(struct task_struct *p, const struct cpumask *new_mask); 1529 1530 #endif 1531 1532 #ifdef CONFIG_CPU_IDLE 1533 static inline void idle_set_state(struct rq *rq, 1534 struct cpuidle_state *idle_state) 1535 { 1536 rq->idle_state = idle_state; 1537 } 1538 1539 static inline struct cpuidle_state *idle_get_state(struct rq *rq) 1540 { 1541 SCHED_WARN_ON(!rcu_read_lock_held()); 1542 return rq->idle_state; 1543 } 1544 #else 1545 static inline void idle_set_state(struct rq *rq, 1546 struct cpuidle_state *idle_state) 1547 { 1548 } 1549 1550 static inline struct cpuidle_state *idle_get_state(struct rq *rq) 1551 { 1552 return NULL; 1553 } 1554 #endif 1555 1556 extern void schedule_idle(void); 1557 1558 extern void sysrq_sched_debug_show(void); 1559 extern void sched_init_granularity(void); 1560 extern void update_max_interval(void); 1561 1562 extern void init_sched_dl_class(void); 1563 extern void init_sched_rt_class(void); 1564 extern void init_sched_fair_class(void); 1565 1566 extern void reweight_task(struct task_struct *p, int prio); 1567 1568 extern void resched_curr(struct rq *rq); 1569 extern void resched_cpu(int cpu); 1570 1571 extern struct rt_bandwidth def_rt_bandwidth; 1572 extern void init_rt_bandwidth(struct rt_bandwidth *rt_b, u64 period, u64 runtime); 1573 1574 extern struct dl_bandwidth def_dl_bandwidth; 1575 extern void init_dl_bandwidth(struct dl_bandwidth *dl_b, u64 period, u64 runtime); 1576 extern void init_dl_task_timer(struct sched_dl_entity *dl_se); 1577 extern void init_dl_inactive_task_timer(struct sched_dl_entity *dl_se); 1578 extern void init_dl_rq_bw_ratio(struct dl_rq *dl_rq); 1579 1580 #define BW_SHIFT 20 1581 #define BW_UNIT (1 << BW_SHIFT) 1582 #define RATIO_SHIFT 8 1583 unsigned long to_ratio(u64 period, u64 runtime); 1584 1585 extern void init_entity_runnable_average(struct sched_entity *se); 1586 extern void post_init_entity_util_avg(struct sched_entity *se); 1587 1588 #ifdef CONFIG_NO_HZ_FULL 1589 extern bool sched_can_stop_tick(struct rq *rq); 1590 1591 /* 1592 * Tick may be needed by tasks in the runqueue depending on their policy and 1593 * requirements. If tick is needed, lets send the target an IPI to kick it out of 1594 * nohz mode if necessary. 1595 */ 1596 static inline void sched_update_tick_dependency(struct rq *rq) 1597 { 1598 int cpu; 1599 1600 if (!tick_nohz_full_enabled()) 1601 return; 1602 1603 cpu = cpu_of(rq); 1604 1605 if (!tick_nohz_full_cpu(cpu)) 1606 return; 1607 1608 if (sched_can_stop_tick(rq)) 1609 tick_nohz_dep_clear_cpu(cpu, TICK_DEP_BIT_SCHED); 1610 else 1611 tick_nohz_dep_set_cpu(cpu, TICK_DEP_BIT_SCHED); 1612 } 1613 #else 1614 static inline void sched_update_tick_dependency(struct rq *rq) { } 1615 #endif 1616 1617 static inline void add_nr_running(struct rq *rq, unsigned count) 1618 { 1619 unsigned prev_nr = rq->nr_running; 1620 1621 rq->nr_running = prev_nr + count; 1622 1623 if (prev_nr < 2 && rq->nr_running >= 2) { 1624 #ifdef CONFIG_SMP 1625 if (!rq->rd->overload) 1626 rq->rd->overload = true; 1627 #endif 1628 } 1629 1630 sched_update_tick_dependency(rq); 1631 } 1632 1633 static inline void sub_nr_running(struct rq *rq, unsigned count) 1634 { 1635 rq->nr_running -= count; 1636 /* Check if we still need preemption */ 1637 sched_update_tick_dependency(rq); 1638 } 1639 1640 static inline void rq_last_tick_reset(struct rq *rq) 1641 { 1642 #ifdef CONFIG_NO_HZ_FULL 1643 rq->last_sched_tick = jiffies; 1644 #endif 1645 } 1646 1647 extern void update_rq_clock(struct rq *rq); 1648 1649 extern void activate_task(struct rq *rq, struct task_struct *p, int flags); 1650 extern void deactivate_task(struct rq *rq, struct task_struct *p, int flags); 1651 1652 extern void check_preempt_curr(struct rq *rq, struct task_struct *p, int flags); 1653 1654 extern const_debug unsigned int sysctl_sched_time_avg; 1655 extern const_debug unsigned int sysctl_sched_nr_migrate; 1656 extern const_debug unsigned int sysctl_sched_migration_cost; 1657 1658 static inline u64 sched_avg_period(void) 1659 { 1660 return (u64)sysctl_sched_time_avg * NSEC_PER_MSEC / 2; 1661 } 1662 1663 #ifdef CONFIG_SCHED_HRTICK 1664 1665 /* 1666 * Use hrtick when: 1667 * - enabled by features 1668 * - hrtimer is actually high res 1669 */ 1670 static inline int hrtick_enabled(struct rq *rq) 1671 { 1672 if (!sched_feat(HRTICK)) 1673 return 0; 1674 if (!cpu_active(cpu_of(rq))) 1675 return 0; 1676 return hrtimer_is_hres_active(&rq->hrtick_timer); 1677 } 1678 1679 void hrtick_start(struct rq *rq, u64 delay); 1680 1681 #else 1682 1683 static inline int hrtick_enabled(struct rq *rq) 1684 { 1685 return 0; 1686 } 1687 1688 #endif /* CONFIG_SCHED_HRTICK */ 1689 1690 #ifdef CONFIG_SMP 1691 extern void sched_avg_update(struct rq *rq); 1692 1693 #ifndef arch_scale_freq_capacity 1694 static __always_inline 1695 unsigned long arch_scale_freq_capacity(struct sched_domain *sd, int cpu) 1696 { 1697 return SCHED_CAPACITY_SCALE; 1698 } 1699 #endif 1700 1701 #ifndef arch_scale_cpu_capacity 1702 static __always_inline 1703 unsigned long arch_scale_cpu_capacity(struct sched_domain *sd, int cpu) 1704 { 1705 if (sd && (sd->flags & SD_SHARE_CPUCAPACITY) && (sd->span_weight > 1)) 1706 return sd->smt_gain / sd->span_weight; 1707 1708 return SCHED_CAPACITY_SCALE; 1709 } 1710 #endif 1711 1712 static inline void sched_rt_avg_update(struct rq *rq, u64 rt_delta) 1713 { 1714 rq->rt_avg += rt_delta * arch_scale_freq_capacity(NULL, cpu_of(rq)); 1715 sched_avg_update(rq); 1716 } 1717 #else 1718 static inline void sched_rt_avg_update(struct rq *rq, u64 rt_delta) { } 1719 static inline void sched_avg_update(struct rq *rq) { } 1720 #endif 1721 1722 struct rq *__task_rq_lock(struct task_struct *p, struct rq_flags *rf) 1723 __acquires(rq->lock); 1724 1725 struct rq *task_rq_lock(struct task_struct *p, struct rq_flags *rf) 1726 __acquires(p->pi_lock) 1727 __acquires(rq->lock); 1728 1729 static inline void __task_rq_unlock(struct rq *rq, struct rq_flags *rf) 1730 __releases(rq->lock) 1731 { 1732 rq_unpin_lock(rq, rf); 1733 raw_spin_unlock(&rq->lock); 1734 } 1735 1736 static inline void 1737 task_rq_unlock(struct rq *rq, struct task_struct *p, struct rq_flags *rf) 1738 __releases(rq->lock) 1739 __releases(p->pi_lock) 1740 { 1741 rq_unpin_lock(rq, rf); 1742 raw_spin_unlock(&rq->lock); 1743 raw_spin_unlock_irqrestore(&p->pi_lock, rf->flags); 1744 } 1745 1746 static inline void 1747 rq_lock_irqsave(struct rq *rq, struct rq_flags *rf) 1748 __acquires(rq->lock) 1749 { 1750 raw_spin_lock_irqsave(&rq->lock, rf->flags); 1751 rq_pin_lock(rq, rf); 1752 } 1753 1754 static inline void 1755 rq_lock_irq(struct rq *rq, struct rq_flags *rf) 1756 __acquires(rq->lock) 1757 { 1758 raw_spin_lock_irq(&rq->lock); 1759 rq_pin_lock(rq, rf); 1760 } 1761 1762 static inline void 1763 rq_lock(struct rq *rq, struct rq_flags *rf) 1764 __acquires(rq->lock) 1765 { 1766 raw_spin_lock(&rq->lock); 1767 rq_pin_lock(rq, rf); 1768 } 1769 1770 static inline void 1771 rq_relock(struct rq *rq, struct rq_flags *rf) 1772 __acquires(rq->lock) 1773 { 1774 raw_spin_lock(&rq->lock); 1775 rq_repin_lock(rq, rf); 1776 } 1777 1778 static inline void 1779 rq_unlock_irqrestore(struct rq *rq, struct rq_flags *rf) 1780 __releases(rq->lock) 1781 { 1782 rq_unpin_lock(rq, rf); 1783 raw_spin_unlock_irqrestore(&rq->lock, rf->flags); 1784 } 1785 1786 static inline void 1787 rq_unlock_irq(struct rq *rq, struct rq_flags *rf) 1788 __releases(rq->lock) 1789 { 1790 rq_unpin_lock(rq, rf); 1791 raw_spin_unlock_irq(&rq->lock); 1792 } 1793 1794 static inline void 1795 rq_unlock(struct rq *rq, struct rq_flags *rf) 1796 __releases(rq->lock) 1797 { 1798 rq_unpin_lock(rq, rf); 1799 raw_spin_unlock(&rq->lock); 1800 } 1801 1802 #ifdef CONFIG_SMP 1803 #ifdef CONFIG_PREEMPT 1804 1805 static inline void double_rq_lock(struct rq *rq1, struct rq *rq2); 1806 1807 /* 1808 * fair double_lock_balance: Safely acquires both rq->locks in a fair 1809 * way at the expense of forcing extra atomic operations in all 1810 * invocations. This assures that the double_lock is acquired using the 1811 * same underlying policy as the spinlock_t on this architecture, which 1812 * reduces latency compared to the unfair variant below. However, it 1813 * also adds more overhead and therefore may reduce throughput. 1814 */ 1815 static inline int _double_lock_balance(struct rq *this_rq, struct rq *busiest) 1816 __releases(this_rq->lock) 1817 __acquires(busiest->lock) 1818 __acquires(this_rq->lock) 1819 { 1820 raw_spin_unlock(&this_rq->lock); 1821 double_rq_lock(this_rq, busiest); 1822 1823 return 1; 1824 } 1825 1826 #else 1827 /* 1828 * Unfair double_lock_balance: Optimizes throughput at the expense of 1829 * latency by eliminating extra atomic operations when the locks are 1830 * already in proper order on entry. This favors lower cpu-ids and will 1831 * grant the double lock to lower cpus over higher ids under contention, 1832 * regardless of entry order into the function. 1833 */ 1834 static inline int _double_lock_balance(struct rq *this_rq, struct rq *busiest) 1835 __releases(this_rq->lock) 1836 __acquires(busiest->lock) 1837 __acquires(this_rq->lock) 1838 { 1839 int ret = 0; 1840 1841 if (unlikely(!raw_spin_trylock(&busiest->lock))) { 1842 if (busiest < this_rq) { 1843 raw_spin_unlock(&this_rq->lock); 1844 raw_spin_lock(&busiest->lock); 1845 raw_spin_lock_nested(&this_rq->lock, 1846 SINGLE_DEPTH_NESTING); 1847 ret = 1; 1848 } else 1849 raw_spin_lock_nested(&busiest->lock, 1850 SINGLE_DEPTH_NESTING); 1851 } 1852 return ret; 1853 } 1854 1855 #endif /* CONFIG_PREEMPT */ 1856 1857 /* 1858 * double_lock_balance - lock the busiest runqueue, this_rq is locked already. 1859 */ 1860 static inline int double_lock_balance(struct rq *this_rq, struct rq *busiest) 1861 { 1862 if (unlikely(!irqs_disabled())) { 1863 /* printk() doesn't work good under rq->lock */ 1864 raw_spin_unlock(&this_rq->lock); 1865 BUG_ON(1); 1866 } 1867 1868 return _double_lock_balance(this_rq, busiest); 1869 } 1870 1871 static inline void double_unlock_balance(struct rq *this_rq, struct rq *busiest) 1872 __releases(busiest->lock) 1873 { 1874 raw_spin_unlock(&busiest->lock); 1875 lock_set_subclass(&this_rq->lock.dep_map, 0, _RET_IP_); 1876 } 1877 1878 static inline void double_lock(spinlock_t *l1, spinlock_t *l2) 1879 { 1880 if (l1 > l2) 1881 swap(l1, l2); 1882 1883 spin_lock(l1); 1884 spin_lock_nested(l2, SINGLE_DEPTH_NESTING); 1885 } 1886 1887 static inline void double_lock_irq(spinlock_t *l1, spinlock_t *l2) 1888 { 1889 if (l1 > l2) 1890 swap(l1, l2); 1891 1892 spin_lock_irq(l1); 1893 spin_lock_nested(l2, SINGLE_DEPTH_NESTING); 1894 } 1895 1896 static inline void double_raw_lock(raw_spinlock_t *l1, raw_spinlock_t *l2) 1897 { 1898 if (l1 > l2) 1899 swap(l1, l2); 1900 1901 raw_spin_lock(l1); 1902 raw_spin_lock_nested(l2, SINGLE_DEPTH_NESTING); 1903 } 1904 1905 /* 1906 * double_rq_lock - safely lock two runqueues 1907 * 1908 * Note this does not disable interrupts like task_rq_lock, 1909 * you need to do so manually before calling. 1910 */ 1911 static inline void double_rq_lock(struct rq *rq1, struct rq *rq2) 1912 __acquires(rq1->lock) 1913 __acquires(rq2->lock) 1914 { 1915 BUG_ON(!irqs_disabled()); 1916 if (rq1 == rq2) { 1917 raw_spin_lock(&rq1->lock); 1918 __acquire(rq2->lock); /* Fake it out ;) */ 1919 } else { 1920 if (rq1 < rq2) { 1921 raw_spin_lock(&rq1->lock); 1922 raw_spin_lock_nested(&rq2->lock, SINGLE_DEPTH_NESTING); 1923 } else { 1924 raw_spin_lock(&rq2->lock); 1925 raw_spin_lock_nested(&rq1->lock, SINGLE_DEPTH_NESTING); 1926 } 1927 } 1928 } 1929 1930 /* 1931 * double_rq_unlock - safely unlock two runqueues 1932 * 1933 * Note this does not restore interrupts like task_rq_unlock, 1934 * you need to do so manually after calling. 1935 */ 1936 static inline void double_rq_unlock(struct rq *rq1, struct rq *rq2) 1937 __releases(rq1->lock) 1938 __releases(rq2->lock) 1939 { 1940 raw_spin_unlock(&rq1->lock); 1941 if (rq1 != rq2) 1942 raw_spin_unlock(&rq2->lock); 1943 else 1944 __release(rq2->lock); 1945 } 1946 1947 extern void set_rq_online (struct rq *rq); 1948 extern void set_rq_offline(struct rq *rq); 1949 extern bool sched_smp_initialized; 1950 1951 #else /* CONFIG_SMP */ 1952 1953 /* 1954 * double_rq_lock - safely lock two runqueues 1955 * 1956 * Note this does not disable interrupts like task_rq_lock, 1957 * you need to do so manually before calling. 1958 */ 1959 static inline void double_rq_lock(struct rq *rq1, struct rq *rq2) 1960 __acquires(rq1->lock) 1961 __acquires(rq2->lock) 1962 { 1963 BUG_ON(!irqs_disabled()); 1964 BUG_ON(rq1 != rq2); 1965 raw_spin_lock(&rq1->lock); 1966 __acquire(rq2->lock); /* Fake it out ;) */ 1967 } 1968 1969 /* 1970 * double_rq_unlock - safely unlock two runqueues 1971 * 1972 * Note this does not restore interrupts like task_rq_unlock, 1973 * you need to do so manually after calling. 1974 */ 1975 static inline void double_rq_unlock(struct rq *rq1, struct rq *rq2) 1976 __releases(rq1->lock) 1977 __releases(rq2->lock) 1978 { 1979 BUG_ON(rq1 != rq2); 1980 raw_spin_unlock(&rq1->lock); 1981 __release(rq2->lock); 1982 } 1983 1984 #endif 1985 1986 extern struct sched_entity *__pick_first_entity(struct cfs_rq *cfs_rq); 1987 extern struct sched_entity *__pick_last_entity(struct cfs_rq *cfs_rq); 1988 1989 #ifdef CONFIG_SCHED_DEBUG 1990 extern bool sched_debug_enabled; 1991 1992 extern void print_cfs_stats(struct seq_file *m, int cpu); 1993 extern void print_rt_stats(struct seq_file *m, int cpu); 1994 extern void print_dl_stats(struct seq_file *m, int cpu); 1995 extern void 1996 print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq); 1997 #ifdef CONFIG_NUMA_BALANCING 1998 extern void 1999 show_numa_stats(struct task_struct *p, struct seq_file *m); 2000 extern void 2001 print_numa_stats(struct seq_file *m, int node, unsigned long tsf, 2002 unsigned long tpf, unsigned long gsf, unsigned long gpf); 2003 #endif /* CONFIG_NUMA_BALANCING */ 2004 #endif /* CONFIG_SCHED_DEBUG */ 2005 2006 extern void init_cfs_rq(struct cfs_rq *cfs_rq); 2007 extern void init_rt_rq(struct rt_rq *rt_rq); 2008 extern void init_dl_rq(struct dl_rq *dl_rq); 2009 2010 extern void cfs_bandwidth_usage_inc(void); 2011 extern void cfs_bandwidth_usage_dec(void); 2012 2013 #ifdef CONFIG_NO_HZ_COMMON 2014 enum rq_nohz_flag_bits { 2015 NOHZ_TICK_STOPPED, 2016 NOHZ_BALANCE_KICK, 2017 }; 2018 2019 #define nohz_flags(cpu) (&cpu_rq(cpu)->nohz_flags) 2020 2021 extern void nohz_balance_exit_idle(unsigned int cpu); 2022 #else 2023 static inline void nohz_balance_exit_idle(unsigned int cpu) { } 2024 #endif 2025 2026 2027 #ifdef CONFIG_SMP 2028 static inline 2029 void __dl_update(struct dl_bw *dl_b, s64 bw) 2030 { 2031 struct root_domain *rd = container_of(dl_b, struct root_domain, dl_bw); 2032 int i; 2033 2034 RCU_LOCKDEP_WARN(!rcu_read_lock_sched_held(), 2035 "sched RCU must be held"); 2036 for_each_cpu_and(i, rd->span, cpu_active_mask) { 2037 struct rq *rq = cpu_rq(i); 2038 2039 rq->dl.extra_bw += bw; 2040 } 2041 } 2042 #else 2043 static inline 2044 void __dl_update(struct dl_bw *dl_b, s64 bw) 2045 { 2046 struct dl_rq *dl = container_of(dl_b, struct dl_rq, dl_bw); 2047 2048 dl->extra_bw += bw; 2049 } 2050 #endif 2051 2052 2053 #ifdef CONFIG_IRQ_TIME_ACCOUNTING 2054 struct irqtime { 2055 u64 total; 2056 u64 tick_delta; 2057 u64 irq_start_time; 2058 struct u64_stats_sync sync; 2059 }; 2060 2061 DECLARE_PER_CPU(struct irqtime, cpu_irqtime); 2062 2063 /* 2064 * Returns the irqtime minus the softirq time computed by ksoftirqd. 2065 * Otherwise ksoftirqd's sum_exec_runtime is substracted its own runtime 2066 * and never move forward. 2067 */ 2068 static inline u64 irq_time_read(int cpu) 2069 { 2070 struct irqtime *irqtime = &per_cpu(cpu_irqtime, cpu); 2071 unsigned int seq; 2072 u64 total; 2073 2074 do { 2075 seq = __u64_stats_fetch_begin(&irqtime->sync); 2076 total = irqtime->total; 2077 } while (__u64_stats_fetch_retry(&irqtime->sync, seq)); 2078 2079 return total; 2080 } 2081 #endif /* CONFIG_IRQ_TIME_ACCOUNTING */ 2082 2083 #ifdef CONFIG_CPU_FREQ 2084 DECLARE_PER_CPU(struct update_util_data *, cpufreq_update_util_data); 2085 2086 /** 2087 * cpufreq_update_util - Take a note about CPU utilization changes. 2088 * @rq: Runqueue to carry out the update for. 2089 * @flags: Update reason flags. 2090 * 2091 * This function is called by the scheduler on the CPU whose utilization is 2092 * being updated. 2093 * 2094 * It can only be called from RCU-sched read-side critical sections. 2095 * 2096 * The way cpufreq is currently arranged requires it to evaluate the CPU 2097 * performance state (frequency/voltage) on a regular basis to prevent it from 2098 * being stuck in a completely inadequate performance level for too long. 2099 * That is not guaranteed to happen if the updates are only triggered from CFS, 2100 * though, because they may not be coming in if RT or deadline tasks are active 2101 * all the time (or there are RT and DL tasks only). 2102 * 2103 * As a workaround for that issue, this function is called by the RT and DL 2104 * sched classes to trigger extra cpufreq updates to prevent it from stalling, 2105 * but that really is a band-aid. Going forward it should be replaced with 2106 * solutions targeted more specifically at RT and DL tasks. 2107 */ 2108 static inline void cpufreq_update_util(struct rq *rq, unsigned int flags) 2109 { 2110 struct update_util_data *data; 2111 2112 data = rcu_dereference_sched(*per_cpu_ptr(&cpufreq_update_util_data, 2113 cpu_of(rq))); 2114 if (data) 2115 data->func(data, rq_clock(rq), flags); 2116 } 2117 #else 2118 static inline void cpufreq_update_util(struct rq *rq, unsigned int flags) {} 2119 #endif /* CONFIG_CPU_FREQ */ 2120 2121 #ifdef arch_scale_freq_capacity 2122 #ifndef arch_scale_freq_invariant 2123 #define arch_scale_freq_invariant() (true) 2124 #endif 2125 #else /* arch_scale_freq_capacity */ 2126 #define arch_scale_freq_invariant() (false) 2127 #endif 2128