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