1 /* SPDX-License-Identifier: GPL-2.0 */ 2 /* 3 * Scheduler internal types and methods: 4 */ 5 #ifndef _KERNEL_SCHED_SCHED_H 6 #define _KERNEL_SCHED_SCHED_H 7 8 #include <linux/sched/affinity.h> 9 #include <linux/sched/autogroup.h> 10 #include <linux/sched/cpufreq.h> 11 #include <linux/sched/deadline.h> 12 #include <linux/sched.h> 13 #include <linux/sched/loadavg.h> 14 #include <linux/sched/mm.h> 15 #include <linux/sched/rseq_api.h> 16 #include <linux/sched/signal.h> 17 #include <linux/sched/smt.h> 18 #include <linux/sched/stat.h> 19 #include <linux/sched/sysctl.h> 20 #include <linux/sched/task_flags.h> 21 #include <linux/sched/task.h> 22 #include <linux/sched/topology.h> 23 24 #include <linux/atomic.h> 25 #include <linux/bitmap.h> 26 #include <linux/bug.h> 27 #include <linux/capability.h> 28 #include <linux/cgroup_api.h> 29 #include <linux/cgroup.h> 30 #include <linux/context_tracking.h> 31 #include <linux/cpufreq.h> 32 #include <linux/cpumask_api.h> 33 #include <linux/ctype.h> 34 #include <linux/file.h> 35 #include <linux/fs_api.h> 36 #include <linux/hrtimer_api.h> 37 #include <linux/interrupt.h> 38 #include <linux/irq_work.h> 39 #include <linux/jiffies.h> 40 #include <linux/kref_api.h> 41 #include <linux/kthread.h> 42 #include <linux/ktime_api.h> 43 #include <linux/lockdep_api.h> 44 #include <linux/lockdep.h> 45 #include <linux/minmax.h> 46 #include <linux/mm.h> 47 #include <linux/module.h> 48 #include <linux/mutex_api.h> 49 #include <linux/plist.h> 50 #include <linux/poll.h> 51 #include <linux/proc_fs.h> 52 #include <linux/profile.h> 53 #include <linux/psi.h> 54 #include <linux/rcupdate.h> 55 #include <linux/seq_file.h> 56 #include <linux/seqlock.h> 57 #include <linux/softirq.h> 58 #include <linux/spinlock_api.h> 59 #include <linux/static_key.h> 60 #include <linux/stop_machine.h> 61 #include <linux/syscalls_api.h> 62 #include <linux/syscalls.h> 63 #include <linux/tick.h> 64 #include <linux/topology.h> 65 #include <linux/types.h> 66 #include <linux/u64_stats_sync_api.h> 67 #include <linux/uaccess.h> 68 #include <linux/wait_api.h> 69 #include <linux/wait_bit.h> 70 #include <linux/workqueue_api.h> 71 72 #include <trace/events/power.h> 73 #include <trace/events/sched.h> 74 75 #include "../workqueue_internal.h" 76 77 #ifdef CONFIG_PARAVIRT 78 # include <asm/paravirt.h> 79 # include <asm/paravirt_api_clock.h> 80 #endif 81 82 #include "cpupri.h" 83 #include "cpudeadline.h" 84 85 #ifdef CONFIG_SCHED_DEBUG 86 # define SCHED_WARN_ON(x) WARN_ONCE(x, #x) 87 #else 88 # define SCHED_WARN_ON(x) ({ (void)(x), 0; }) 89 #endif 90 91 struct rq; 92 struct cpuidle_state; 93 94 /* task_struct::on_rq states: */ 95 #define TASK_ON_RQ_QUEUED 1 96 #define TASK_ON_RQ_MIGRATING 2 97 98 extern __read_mostly int scheduler_running; 99 100 extern unsigned long calc_load_update; 101 extern atomic_long_t calc_load_tasks; 102 103 extern void calc_global_load_tick(struct rq *this_rq); 104 extern long calc_load_fold_active(struct rq *this_rq, long adjust); 105 106 extern void call_trace_sched_update_nr_running(struct rq *rq, int count); 107 108 extern int sysctl_sched_rt_period; 109 extern int sysctl_sched_rt_runtime; 110 extern int sched_rr_timeslice; 111 112 /* 113 * Helpers for converting nanosecond timing to jiffy resolution 114 */ 115 #define NS_TO_JIFFIES(TIME) ((unsigned long)(TIME) / (NSEC_PER_SEC / HZ)) 116 117 /* 118 * Increase resolution of nice-level calculations for 64-bit architectures. 119 * The extra resolution improves shares distribution and load balancing of 120 * low-weight task groups (eg. nice +19 on an autogroup), deeper taskgroup 121 * hierarchies, especially on larger systems. This is not a user-visible change 122 * and does not change the user-interface for setting shares/weights. 123 * 124 * We increase resolution only if we have enough bits to allow this increased 125 * resolution (i.e. 64-bit). The costs for increasing resolution when 32-bit 126 * are pretty high and the returns do not justify the increased costs. 127 * 128 * Really only required when CONFIG_FAIR_GROUP_SCHED=y is also set, but to 129 * increase coverage and consistency always enable it on 64-bit platforms. 130 */ 131 #ifdef CONFIG_64BIT 132 # define NICE_0_LOAD_SHIFT (SCHED_FIXEDPOINT_SHIFT + SCHED_FIXEDPOINT_SHIFT) 133 # define scale_load(w) ((w) << SCHED_FIXEDPOINT_SHIFT) 134 # define scale_load_down(w) \ 135 ({ \ 136 unsigned long __w = (w); \ 137 if (__w) \ 138 __w = max(2UL, __w >> SCHED_FIXEDPOINT_SHIFT); \ 139 __w; \ 140 }) 141 #else 142 # define NICE_0_LOAD_SHIFT (SCHED_FIXEDPOINT_SHIFT) 143 # define scale_load(w) (w) 144 # define scale_load_down(w) (w) 145 #endif 146 147 /* 148 * Task weight (visible to users) and its load (invisible to users) have 149 * independent resolution, but they should be well calibrated. We use 150 * scale_load() and scale_load_down(w) to convert between them. The 151 * following must be true: 152 * 153 * scale_load(sched_prio_to_weight[NICE_TO_PRIO(0)-MAX_RT_PRIO]) == NICE_0_LOAD 154 * 155 */ 156 #define NICE_0_LOAD (1L << NICE_0_LOAD_SHIFT) 157 158 /* 159 * Single value that decides SCHED_DEADLINE internal math precision. 160 * 10 -> just above 1us 161 * 9 -> just above 0.5us 162 */ 163 #define DL_SCALE 10 164 165 /* 166 * Single value that denotes runtime == period, ie unlimited time. 167 */ 168 #define RUNTIME_INF ((u64)~0ULL) 169 170 static inline int idle_policy(int policy) 171 { 172 return policy == SCHED_IDLE; 173 } 174 static inline int fair_policy(int policy) 175 { 176 return policy == SCHED_NORMAL || policy == SCHED_BATCH; 177 } 178 179 static inline int rt_policy(int policy) 180 { 181 return policy == SCHED_FIFO || policy == SCHED_RR; 182 } 183 184 static inline int dl_policy(int policy) 185 { 186 return policy == SCHED_DEADLINE; 187 } 188 static inline bool valid_policy(int policy) 189 { 190 return idle_policy(policy) || fair_policy(policy) || 191 rt_policy(policy) || dl_policy(policy); 192 } 193 194 static inline int task_has_idle_policy(struct task_struct *p) 195 { 196 return idle_policy(p->policy); 197 } 198 199 static inline int task_has_rt_policy(struct task_struct *p) 200 { 201 return rt_policy(p->policy); 202 } 203 204 static inline int task_has_dl_policy(struct task_struct *p) 205 { 206 return dl_policy(p->policy); 207 } 208 209 #define cap_scale(v, s) ((v)*(s) >> SCHED_CAPACITY_SHIFT) 210 211 static inline void update_avg(u64 *avg, u64 sample) 212 { 213 s64 diff = sample - *avg; 214 *avg += diff / 8; 215 } 216 217 /* 218 * Shifting a value by an exponent greater *or equal* to the size of said value 219 * is UB; cap at size-1. 220 */ 221 #define shr_bound(val, shift) \ 222 (val >> min_t(typeof(shift), shift, BITS_PER_TYPE(typeof(val)) - 1)) 223 224 /* 225 * !! For sched_setattr_nocheck() (kernel) only !! 226 * 227 * This is actually gross. :( 228 * 229 * It is used to make schedutil kworker(s) higher priority than SCHED_DEADLINE 230 * tasks, but still be able to sleep. We need this on platforms that cannot 231 * atomically change clock frequency. Remove once fast switching will be 232 * available on such platforms. 233 * 234 * SUGOV stands for SchedUtil GOVernor. 235 */ 236 #define SCHED_FLAG_SUGOV 0x10000000 237 238 #define SCHED_DL_FLAGS (SCHED_FLAG_RECLAIM | SCHED_FLAG_DL_OVERRUN | SCHED_FLAG_SUGOV) 239 240 static inline bool dl_entity_is_special(const struct sched_dl_entity *dl_se) 241 { 242 #ifdef CONFIG_CPU_FREQ_GOV_SCHEDUTIL 243 return unlikely(dl_se->flags & SCHED_FLAG_SUGOV); 244 #else 245 return false; 246 #endif 247 } 248 249 /* 250 * Tells if entity @a should preempt entity @b. 251 */ 252 static inline bool dl_entity_preempt(const struct sched_dl_entity *a, 253 const struct sched_dl_entity *b) 254 { 255 return dl_entity_is_special(a) || 256 dl_time_before(a->deadline, b->deadline); 257 } 258 259 /* 260 * This is the priority-queue data structure of the RT scheduling class: 261 */ 262 struct rt_prio_array { 263 DECLARE_BITMAP(bitmap, MAX_RT_PRIO+1); /* include 1 bit for delimiter */ 264 struct list_head queue[MAX_RT_PRIO]; 265 }; 266 267 struct rt_bandwidth { 268 /* nests inside the rq lock: */ 269 raw_spinlock_t rt_runtime_lock; 270 ktime_t rt_period; 271 u64 rt_runtime; 272 struct hrtimer rt_period_timer; 273 unsigned int rt_period_active; 274 }; 275 276 void __dl_clear_params(struct task_struct *p); 277 278 static inline int dl_bandwidth_enabled(void) 279 { 280 return sysctl_sched_rt_runtime >= 0; 281 } 282 283 /* 284 * To keep the bandwidth of -deadline tasks under control 285 * we need some place where: 286 * - store the maximum -deadline bandwidth of each cpu; 287 * - cache the fraction of bandwidth that is currently allocated in 288 * each root domain; 289 * 290 * This is all done in the data structure below. It is similar to the 291 * one used for RT-throttling (rt_bandwidth), with the main difference 292 * that, since here we are only interested in admission control, we 293 * do not decrease any runtime while the group "executes", neither we 294 * need a timer to replenish it. 295 * 296 * With respect to SMP, bandwidth is given on a per root domain basis, 297 * meaning that: 298 * - bw (< 100%) is the deadline bandwidth of each CPU; 299 * - total_bw is the currently allocated bandwidth in each root domain; 300 */ 301 struct dl_bw { 302 raw_spinlock_t lock; 303 u64 bw; 304 u64 total_bw; 305 }; 306 307 extern void init_dl_bw(struct dl_bw *dl_b); 308 extern int sched_dl_global_validate(void); 309 extern void sched_dl_do_global(void); 310 extern int sched_dl_overflow(struct task_struct *p, int policy, const struct sched_attr *attr); 311 extern void __setparam_dl(struct task_struct *p, const struct sched_attr *attr); 312 extern void __getparam_dl(struct task_struct *p, struct sched_attr *attr); 313 extern bool __checkparam_dl(const struct sched_attr *attr); 314 extern bool dl_param_changed(struct task_struct *p, const struct sched_attr *attr); 315 extern int dl_cpuset_cpumask_can_shrink(const struct cpumask *cur, const struct cpumask *trial); 316 extern int dl_bw_check_overflow(int cpu); 317 318 #ifdef CONFIG_CGROUP_SCHED 319 320 struct cfs_rq; 321 struct rt_rq; 322 323 extern struct list_head task_groups; 324 325 struct cfs_bandwidth { 326 #ifdef CONFIG_CFS_BANDWIDTH 327 raw_spinlock_t lock; 328 ktime_t period; 329 u64 quota; 330 u64 runtime; 331 u64 burst; 332 u64 runtime_snap; 333 s64 hierarchical_quota; 334 335 u8 idle; 336 u8 period_active; 337 u8 slack_started; 338 struct hrtimer period_timer; 339 struct hrtimer slack_timer; 340 struct list_head throttled_cfs_rq; 341 342 /* Statistics: */ 343 int nr_periods; 344 int nr_throttled; 345 int nr_burst; 346 u64 throttled_time; 347 u64 burst_time; 348 #endif 349 }; 350 351 /* Task group related information */ 352 struct task_group { 353 struct cgroup_subsys_state css; 354 355 #ifdef CONFIG_FAIR_GROUP_SCHED 356 /* schedulable entities of this group on each CPU */ 357 struct sched_entity **se; 358 /* runqueue "owned" by this group on each CPU */ 359 struct cfs_rq **cfs_rq; 360 unsigned long shares; 361 362 /* A positive value indicates that this is a SCHED_IDLE group. */ 363 int idle; 364 365 #ifdef CONFIG_SMP 366 /* 367 * load_avg can be heavily contended at clock tick time, so put 368 * it in its own cacheline separated from the fields above which 369 * will also be accessed at each tick. 370 */ 371 atomic_long_t load_avg ____cacheline_aligned; 372 #endif 373 #endif 374 375 #ifdef CONFIG_RT_GROUP_SCHED 376 struct sched_rt_entity **rt_se; 377 struct rt_rq **rt_rq; 378 379 struct rt_bandwidth rt_bandwidth; 380 #endif 381 382 struct rcu_head rcu; 383 struct list_head list; 384 385 struct task_group *parent; 386 struct list_head siblings; 387 struct list_head children; 388 389 #ifdef CONFIG_SCHED_AUTOGROUP 390 struct autogroup *autogroup; 391 #endif 392 393 struct cfs_bandwidth cfs_bandwidth; 394 395 #ifdef CONFIG_UCLAMP_TASK_GROUP 396 /* The two decimal precision [%] value requested from user-space */ 397 unsigned int uclamp_pct[UCLAMP_CNT]; 398 /* Clamp values requested for a task group */ 399 struct uclamp_se uclamp_req[UCLAMP_CNT]; 400 /* Effective clamp values used for a task group */ 401 struct uclamp_se uclamp[UCLAMP_CNT]; 402 #endif 403 404 }; 405 406 #ifdef CONFIG_FAIR_GROUP_SCHED 407 #define ROOT_TASK_GROUP_LOAD NICE_0_LOAD 408 409 /* 410 * A weight of 0 or 1 can cause arithmetics problems. 411 * A weight of a cfs_rq is the sum of weights of which entities 412 * are queued on this cfs_rq, so a weight of a entity should not be 413 * too large, so as the shares value of a task group. 414 * (The default weight is 1024 - so there's no practical 415 * limitation from this.) 416 */ 417 #define MIN_SHARES (1UL << 1) 418 #define MAX_SHARES (1UL << 18) 419 #endif 420 421 typedef int (*tg_visitor)(struct task_group *, void *); 422 423 extern int walk_tg_tree_from(struct task_group *from, 424 tg_visitor down, tg_visitor up, void *data); 425 426 /* 427 * Iterate the full tree, calling @down when first entering a node and @up when 428 * leaving it for the final time. 429 * 430 * Caller must hold rcu_lock or sufficient equivalent. 431 */ 432 static inline int walk_tg_tree(tg_visitor down, tg_visitor up, void *data) 433 { 434 return walk_tg_tree_from(&root_task_group, down, up, data); 435 } 436 437 extern int tg_nop(struct task_group *tg, void *data); 438 439 extern void free_fair_sched_group(struct task_group *tg); 440 extern int alloc_fair_sched_group(struct task_group *tg, struct task_group *parent); 441 extern void online_fair_sched_group(struct task_group *tg); 442 extern void unregister_fair_sched_group(struct task_group *tg); 443 extern void init_tg_cfs_entry(struct task_group *tg, struct cfs_rq *cfs_rq, 444 struct sched_entity *se, int cpu, 445 struct sched_entity *parent); 446 extern void init_cfs_bandwidth(struct cfs_bandwidth *cfs_b, struct cfs_bandwidth *parent); 447 448 extern void __refill_cfs_bandwidth_runtime(struct cfs_bandwidth *cfs_b); 449 extern void start_cfs_bandwidth(struct cfs_bandwidth *cfs_b); 450 extern void unthrottle_cfs_rq(struct cfs_rq *cfs_rq); 451 extern bool cfs_task_bw_constrained(struct task_struct *p); 452 453 extern void init_tg_rt_entry(struct task_group *tg, struct rt_rq *rt_rq, 454 struct sched_rt_entity *rt_se, int cpu, 455 struct sched_rt_entity *parent); 456 extern int sched_group_set_rt_runtime(struct task_group *tg, long rt_runtime_us); 457 extern int sched_group_set_rt_period(struct task_group *tg, u64 rt_period_us); 458 extern long sched_group_rt_runtime(struct task_group *tg); 459 extern long sched_group_rt_period(struct task_group *tg); 460 extern int sched_rt_can_attach(struct task_group *tg, struct task_struct *tsk); 461 462 extern struct task_group *sched_create_group(struct task_group *parent); 463 extern void sched_online_group(struct task_group *tg, 464 struct task_group *parent); 465 extern void sched_destroy_group(struct task_group *tg); 466 extern void sched_release_group(struct task_group *tg); 467 468 extern void sched_move_task(struct task_struct *tsk); 469 470 #ifdef CONFIG_FAIR_GROUP_SCHED 471 extern int sched_group_set_shares(struct task_group *tg, unsigned long shares); 472 473 extern int sched_group_set_idle(struct task_group *tg, long idle); 474 475 #ifdef CONFIG_SMP 476 extern void set_task_rq_fair(struct sched_entity *se, 477 struct cfs_rq *prev, struct cfs_rq *next); 478 #else /* !CONFIG_SMP */ 479 static inline void set_task_rq_fair(struct sched_entity *se, 480 struct cfs_rq *prev, struct cfs_rq *next) { } 481 #endif /* CONFIG_SMP */ 482 #endif /* CONFIG_FAIR_GROUP_SCHED */ 483 484 #else /* CONFIG_CGROUP_SCHED */ 485 486 struct cfs_bandwidth { }; 487 static inline bool cfs_task_bw_constrained(struct task_struct *p) { return false; } 488 489 #endif /* CONFIG_CGROUP_SCHED */ 490 491 extern void unregister_rt_sched_group(struct task_group *tg); 492 extern void free_rt_sched_group(struct task_group *tg); 493 extern int alloc_rt_sched_group(struct task_group *tg, struct task_group *parent); 494 495 /* 496 * u64_u32_load/u64_u32_store 497 * 498 * Use a copy of a u64 value to protect against data race. This is only 499 * applicable for 32-bits architectures. 500 */ 501 #ifdef CONFIG_64BIT 502 # define u64_u32_load_copy(var, copy) var 503 # define u64_u32_store_copy(var, copy, val) (var = val) 504 #else 505 # define u64_u32_load_copy(var, copy) \ 506 ({ \ 507 u64 __val, __val_copy; \ 508 do { \ 509 __val_copy = copy; \ 510 /* \ 511 * paired with u64_u32_store_copy(), ordering access \ 512 * to var and copy. \ 513 */ \ 514 smp_rmb(); \ 515 __val = var; \ 516 } while (__val != __val_copy); \ 517 __val; \ 518 }) 519 # define u64_u32_store_copy(var, copy, val) \ 520 do { \ 521 typeof(val) __val = (val); \ 522 var = __val; \ 523 /* \ 524 * paired with u64_u32_load_copy(), ordering access to var and \ 525 * copy. \ 526 */ \ 527 smp_wmb(); \ 528 copy = __val; \ 529 } while (0) 530 #endif 531 # define u64_u32_load(var) u64_u32_load_copy(var, var##_copy) 532 # define u64_u32_store(var, val) u64_u32_store_copy(var, var##_copy, val) 533 534 /* CFS-related fields in a runqueue */ 535 struct cfs_rq { 536 struct load_weight load; 537 unsigned int nr_running; 538 unsigned int h_nr_running; /* SCHED_{NORMAL,BATCH,IDLE} */ 539 unsigned int idle_nr_running; /* SCHED_IDLE */ 540 unsigned int idle_h_nr_running; /* SCHED_IDLE */ 541 542 s64 avg_vruntime; 543 u64 avg_load; 544 545 u64 exec_clock; 546 u64 min_vruntime; 547 #ifdef CONFIG_SCHED_CORE 548 unsigned int forceidle_seq; 549 u64 min_vruntime_fi; 550 #endif 551 552 #ifndef CONFIG_64BIT 553 u64 min_vruntime_copy; 554 #endif 555 556 struct rb_root_cached tasks_timeline; 557 558 /* 559 * 'curr' points to currently running entity on this cfs_rq. 560 * It is set to NULL otherwise (i.e when none are currently running). 561 */ 562 struct sched_entity *curr; 563 struct sched_entity *next; 564 565 #ifdef CONFIG_SCHED_DEBUG 566 unsigned int nr_spread_over; 567 #endif 568 569 #ifdef CONFIG_SMP 570 /* 571 * CFS load tracking 572 */ 573 struct sched_avg avg; 574 #ifndef CONFIG_64BIT 575 u64 last_update_time_copy; 576 #endif 577 struct { 578 raw_spinlock_t lock ____cacheline_aligned; 579 int nr; 580 unsigned long load_avg; 581 unsigned long util_avg; 582 unsigned long runnable_avg; 583 } removed; 584 585 #ifdef CONFIG_FAIR_GROUP_SCHED 586 u64 last_update_tg_load_avg; 587 unsigned long tg_load_avg_contrib; 588 long propagate; 589 long prop_runnable_sum; 590 591 /* 592 * h_load = weight * f(tg) 593 * 594 * Where f(tg) is the recursive weight fraction assigned to 595 * this group. 596 */ 597 unsigned long h_load; 598 u64 last_h_load_update; 599 struct sched_entity *h_load_next; 600 #endif /* CONFIG_FAIR_GROUP_SCHED */ 601 #endif /* CONFIG_SMP */ 602 603 #ifdef CONFIG_FAIR_GROUP_SCHED 604 struct rq *rq; /* CPU runqueue to which this cfs_rq is attached */ 605 606 /* 607 * leaf cfs_rqs are those that hold tasks (lowest schedulable entity in 608 * a hierarchy). Non-leaf lrqs hold other higher schedulable entities 609 * (like users, containers etc.) 610 * 611 * leaf_cfs_rq_list ties together list of leaf cfs_rq's in a CPU. 612 * This list is used during load balance. 613 */ 614 int on_list; 615 struct list_head leaf_cfs_rq_list; 616 struct task_group *tg; /* group that "owns" this runqueue */ 617 618 /* Locally cached copy of our task_group's idle value */ 619 int idle; 620 621 #ifdef CONFIG_CFS_BANDWIDTH 622 int runtime_enabled; 623 s64 runtime_remaining; 624 625 u64 throttled_pelt_idle; 626 #ifndef CONFIG_64BIT 627 u64 throttled_pelt_idle_copy; 628 #endif 629 u64 throttled_clock; 630 u64 throttled_clock_pelt; 631 u64 throttled_clock_pelt_time; 632 u64 throttled_clock_self; 633 u64 throttled_clock_self_time; 634 int throttled; 635 int throttle_count; 636 struct list_head throttled_list; 637 struct list_head throttled_csd_list; 638 #endif /* CONFIG_CFS_BANDWIDTH */ 639 #endif /* CONFIG_FAIR_GROUP_SCHED */ 640 }; 641 642 static inline int rt_bandwidth_enabled(void) 643 { 644 return sysctl_sched_rt_runtime >= 0; 645 } 646 647 /* RT IPI pull logic requires IRQ_WORK */ 648 #if defined(CONFIG_IRQ_WORK) && defined(CONFIG_SMP) 649 # define HAVE_RT_PUSH_IPI 650 #endif 651 652 /* Real-Time classes' related field in a runqueue: */ 653 struct rt_rq { 654 struct rt_prio_array active; 655 unsigned int rt_nr_running; 656 unsigned int rr_nr_running; 657 #if defined CONFIG_SMP || defined CONFIG_RT_GROUP_SCHED 658 struct { 659 int curr; /* highest queued rt task prio */ 660 #ifdef CONFIG_SMP 661 int next; /* next highest */ 662 #endif 663 } highest_prio; 664 #endif 665 #ifdef CONFIG_SMP 666 int overloaded; 667 struct plist_head pushable_tasks; 668 669 #endif /* CONFIG_SMP */ 670 int rt_queued; 671 672 int rt_throttled; 673 u64 rt_time; 674 u64 rt_runtime; 675 /* Nests inside the rq lock: */ 676 raw_spinlock_t rt_runtime_lock; 677 678 #ifdef CONFIG_RT_GROUP_SCHED 679 unsigned int rt_nr_boosted; 680 681 struct rq *rq; 682 struct task_group *tg; 683 #endif 684 }; 685 686 static inline bool rt_rq_is_runnable(struct rt_rq *rt_rq) 687 { 688 return rt_rq->rt_queued && rt_rq->rt_nr_running; 689 } 690 691 /* Deadline class' related fields in a runqueue */ 692 struct dl_rq { 693 /* runqueue is an rbtree, ordered by deadline */ 694 struct rb_root_cached root; 695 696 unsigned int dl_nr_running; 697 698 #ifdef CONFIG_SMP 699 /* 700 * Deadline values of the currently executing and the 701 * earliest ready task on this rq. Caching these facilitates 702 * the decision whether or not a ready but not running task 703 * should migrate somewhere else. 704 */ 705 struct { 706 u64 curr; 707 u64 next; 708 } earliest_dl; 709 710 int overloaded; 711 712 /* 713 * Tasks on this rq that can be pushed away. They are kept in 714 * an rb-tree, ordered by tasks' deadlines, with caching 715 * of the leftmost (earliest deadline) element. 716 */ 717 struct rb_root_cached pushable_dl_tasks_root; 718 #else 719 struct dl_bw dl_bw; 720 #endif 721 /* 722 * "Active utilization" for this runqueue: increased when a 723 * task wakes up (becomes TASK_RUNNING) and decreased when a 724 * task blocks 725 */ 726 u64 running_bw; 727 728 /* 729 * Utilization of the tasks "assigned" to this runqueue (including 730 * the tasks that are in runqueue and the tasks that executed on this 731 * CPU and blocked). Increased when a task moves to this runqueue, and 732 * decreased when the task moves away (migrates, changes scheduling 733 * policy, or terminates). 734 * This is needed to compute the "inactive utilization" for the 735 * runqueue (inactive utilization = this_bw - running_bw). 736 */ 737 u64 this_bw; 738 u64 extra_bw; 739 740 /* 741 * Maximum available bandwidth for reclaiming by SCHED_FLAG_RECLAIM 742 * tasks of this rq. Used in calculation of reclaimable bandwidth(GRUB). 743 */ 744 u64 max_bw; 745 746 /* 747 * Inverse of the fraction of CPU utilization that can be reclaimed 748 * by the GRUB algorithm. 749 */ 750 u64 bw_ratio; 751 }; 752 753 #ifdef CONFIG_FAIR_GROUP_SCHED 754 /* An entity is a task if it doesn't "own" a runqueue */ 755 #define entity_is_task(se) (!se->my_q) 756 757 static inline void se_update_runnable(struct sched_entity *se) 758 { 759 if (!entity_is_task(se)) 760 se->runnable_weight = se->my_q->h_nr_running; 761 } 762 763 static inline long se_runnable(struct sched_entity *se) 764 { 765 if (entity_is_task(se)) 766 return !!se->on_rq; 767 else 768 return se->runnable_weight; 769 } 770 771 #else 772 #define entity_is_task(se) 1 773 774 static inline void se_update_runnable(struct sched_entity *se) {} 775 776 static inline long se_runnable(struct sched_entity *se) 777 { 778 return !!se->on_rq; 779 } 780 #endif 781 782 #ifdef CONFIG_SMP 783 /* 784 * XXX we want to get rid of these helpers and use the full load resolution. 785 */ 786 static inline long se_weight(struct sched_entity *se) 787 { 788 return scale_load_down(se->load.weight); 789 } 790 791 792 static inline bool sched_asym_prefer(int a, int b) 793 { 794 return arch_asym_cpu_priority(a) > arch_asym_cpu_priority(b); 795 } 796 797 struct perf_domain { 798 struct em_perf_domain *em_pd; 799 struct perf_domain *next; 800 struct rcu_head rcu; 801 }; 802 803 /* Scheduling group status flags */ 804 #define SG_OVERLOAD 0x1 /* More than one runnable task on a CPU. */ 805 #define SG_OVERUTILIZED 0x2 /* One or more CPUs are over-utilized. */ 806 807 /* 808 * We add the notion of a root-domain which will be used to define per-domain 809 * variables. Each exclusive cpuset essentially defines an island domain by 810 * fully partitioning the member CPUs from any other cpuset. Whenever a new 811 * exclusive cpuset is created, we also create and attach a new root-domain 812 * object. 813 * 814 */ 815 struct root_domain { 816 atomic_t refcount; 817 atomic_t rto_count; 818 struct rcu_head rcu; 819 cpumask_var_t span; 820 cpumask_var_t online; 821 822 /* 823 * Indicate pullable load on at least one CPU, e.g: 824 * - More than one runnable task 825 * - Running task is misfit 826 */ 827 int overload; 828 829 /* Indicate one or more cpus over-utilized (tipping point) */ 830 int overutilized; 831 832 /* 833 * The bit corresponding to a CPU gets set here if such CPU has more 834 * than one runnable -deadline task (as it is below for RT tasks). 835 */ 836 cpumask_var_t dlo_mask; 837 atomic_t dlo_count; 838 struct dl_bw dl_bw; 839 struct cpudl cpudl; 840 841 /* 842 * Indicate whether a root_domain's dl_bw has been checked or 843 * updated. It's monotonously increasing value. 844 * 845 * Also, some corner cases, like 'wrap around' is dangerous, but given 846 * that u64 is 'big enough'. So that shouldn't be a concern. 847 */ 848 u64 visit_gen; 849 850 #ifdef HAVE_RT_PUSH_IPI 851 /* 852 * For IPI pull requests, loop across the rto_mask. 853 */ 854 struct irq_work rto_push_work; 855 raw_spinlock_t rto_lock; 856 /* These are only updated and read within rto_lock */ 857 int rto_loop; 858 int rto_cpu; 859 /* These atomics are updated outside of a lock */ 860 atomic_t rto_loop_next; 861 atomic_t rto_loop_start; 862 #endif 863 /* 864 * The "RT overload" flag: it gets set if a CPU has more than 865 * one runnable RT task. 866 */ 867 cpumask_var_t rto_mask; 868 struct cpupri cpupri; 869 870 unsigned long max_cpu_capacity; 871 872 /* 873 * NULL-terminated list of performance domains intersecting with the 874 * CPUs of the rd. Protected by RCU. 875 */ 876 struct perf_domain __rcu *pd; 877 }; 878 879 extern void init_defrootdomain(void); 880 extern int sched_init_domains(const struct cpumask *cpu_map); 881 extern void rq_attach_root(struct rq *rq, struct root_domain *rd); 882 extern void sched_get_rd(struct root_domain *rd); 883 extern void sched_put_rd(struct root_domain *rd); 884 885 #ifdef HAVE_RT_PUSH_IPI 886 extern void rto_push_irq_work_func(struct irq_work *work); 887 #endif 888 #endif /* CONFIG_SMP */ 889 890 #ifdef CONFIG_UCLAMP_TASK 891 /* 892 * struct uclamp_bucket - Utilization clamp bucket 893 * @value: utilization clamp value for tasks on this clamp bucket 894 * @tasks: number of RUNNABLE tasks on this clamp bucket 895 * 896 * Keep track of how many tasks are RUNNABLE for a given utilization 897 * clamp value. 898 */ 899 struct uclamp_bucket { 900 unsigned long value : bits_per(SCHED_CAPACITY_SCALE); 901 unsigned long tasks : BITS_PER_LONG - bits_per(SCHED_CAPACITY_SCALE); 902 }; 903 904 /* 905 * struct uclamp_rq - rq's utilization clamp 906 * @value: currently active clamp values for a rq 907 * @bucket: utilization clamp buckets affecting a rq 908 * 909 * Keep track of RUNNABLE tasks on a rq to aggregate their clamp values. 910 * A clamp value is affecting a rq when there is at least one task RUNNABLE 911 * (or actually running) with that value. 912 * 913 * There are up to UCLAMP_CNT possible different clamp values, currently there 914 * are only two: minimum utilization and maximum utilization. 915 * 916 * All utilization clamping values are MAX aggregated, since: 917 * - for util_min: we want to run the CPU at least at the max of the minimum 918 * utilization required by its currently RUNNABLE tasks. 919 * - for util_max: we want to allow the CPU to run up to the max of the 920 * maximum utilization allowed by its currently RUNNABLE tasks. 921 * 922 * Since on each system we expect only a limited number of different 923 * utilization clamp values (UCLAMP_BUCKETS), use a simple array to track 924 * the metrics required to compute all the per-rq utilization clamp values. 925 */ 926 struct uclamp_rq { 927 unsigned int value; 928 struct uclamp_bucket bucket[UCLAMP_BUCKETS]; 929 }; 930 931 DECLARE_STATIC_KEY_FALSE(sched_uclamp_used); 932 #endif /* CONFIG_UCLAMP_TASK */ 933 934 struct rq; 935 struct balance_callback { 936 struct balance_callback *next; 937 void (*func)(struct rq *rq); 938 }; 939 940 /* 941 * This is the main, per-CPU runqueue data structure. 942 * 943 * Locking rule: those places that want to lock multiple runqueues 944 * (such as the load balancing or the thread migration code), lock 945 * acquire operations must be ordered by ascending &runqueue. 946 */ 947 struct rq { 948 /* runqueue lock: */ 949 raw_spinlock_t __lock; 950 951 unsigned int nr_running; 952 #ifdef CONFIG_NUMA_BALANCING 953 unsigned int nr_numa_running; 954 unsigned int nr_preferred_running; 955 unsigned int numa_migrate_on; 956 #endif 957 #ifdef CONFIG_NO_HZ_COMMON 958 #ifdef CONFIG_SMP 959 unsigned long last_blocked_load_update_tick; 960 unsigned int has_blocked_load; 961 call_single_data_t nohz_csd; 962 #endif /* CONFIG_SMP */ 963 unsigned int nohz_tick_stopped; 964 atomic_t nohz_flags; 965 #endif /* CONFIG_NO_HZ_COMMON */ 966 967 #ifdef CONFIG_SMP 968 unsigned int ttwu_pending; 969 #endif 970 u64 nr_switches; 971 972 #ifdef CONFIG_UCLAMP_TASK 973 /* Utilization clamp values based on CPU's RUNNABLE tasks */ 974 struct uclamp_rq uclamp[UCLAMP_CNT] ____cacheline_aligned; 975 unsigned int uclamp_flags; 976 #define UCLAMP_FLAG_IDLE 0x01 977 #endif 978 979 struct cfs_rq cfs; 980 struct rt_rq rt; 981 struct dl_rq dl; 982 983 #ifdef CONFIG_FAIR_GROUP_SCHED 984 /* list of leaf cfs_rq on this CPU: */ 985 struct list_head leaf_cfs_rq_list; 986 struct list_head *tmp_alone_branch; 987 #endif /* CONFIG_FAIR_GROUP_SCHED */ 988 989 /* 990 * This is part of a global counter where only the total sum 991 * over all CPUs matters. A task can increase this counter on 992 * one CPU and if it got migrated afterwards it may decrease 993 * it on another CPU. Always updated under the runqueue lock: 994 */ 995 unsigned int nr_uninterruptible; 996 997 struct task_struct __rcu *curr; 998 struct task_struct *idle; 999 struct task_struct *stop; 1000 unsigned long next_balance; 1001 struct mm_struct *prev_mm; 1002 1003 unsigned int clock_update_flags; 1004 u64 clock; 1005 /* Ensure that all clocks are in the same cache line */ 1006 u64 clock_task ____cacheline_aligned; 1007 u64 clock_pelt; 1008 unsigned long lost_idle_time; 1009 u64 clock_pelt_idle; 1010 u64 clock_idle; 1011 #ifndef CONFIG_64BIT 1012 u64 clock_pelt_idle_copy; 1013 u64 clock_idle_copy; 1014 #endif 1015 1016 atomic_t nr_iowait; 1017 1018 #ifdef CONFIG_SCHED_DEBUG 1019 u64 last_seen_need_resched_ns; 1020 int ticks_without_resched; 1021 #endif 1022 1023 #ifdef CONFIG_MEMBARRIER 1024 int membarrier_state; 1025 #endif 1026 1027 #ifdef CONFIG_SMP 1028 struct root_domain *rd; 1029 struct sched_domain __rcu *sd; 1030 1031 unsigned long cpu_capacity; 1032 1033 struct balance_callback *balance_callback; 1034 1035 unsigned char nohz_idle_balance; 1036 unsigned char idle_balance; 1037 1038 unsigned long misfit_task_load; 1039 1040 /* For active balancing */ 1041 int active_balance; 1042 int push_cpu; 1043 struct cpu_stop_work active_balance_work; 1044 1045 /* CPU of this runqueue: */ 1046 int cpu; 1047 int online; 1048 1049 struct list_head cfs_tasks; 1050 1051 struct sched_avg avg_rt; 1052 struct sched_avg avg_dl; 1053 #ifdef CONFIG_HAVE_SCHED_AVG_IRQ 1054 struct sched_avg avg_irq; 1055 #endif 1056 #ifdef CONFIG_SCHED_THERMAL_PRESSURE 1057 struct sched_avg avg_thermal; 1058 #endif 1059 u64 idle_stamp; 1060 u64 avg_idle; 1061 1062 /* This is used to determine avg_idle's max value */ 1063 u64 max_idle_balance_cost; 1064 1065 #ifdef CONFIG_HOTPLUG_CPU 1066 struct rcuwait hotplug_wait; 1067 #endif 1068 #endif /* CONFIG_SMP */ 1069 1070 #ifdef CONFIG_IRQ_TIME_ACCOUNTING 1071 u64 prev_irq_time; 1072 #endif 1073 #ifdef CONFIG_PARAVIRT 1074 u64 prev_steal_time; 1075 #endif 1076 #ifdef CONFIG_PARAVIRT_TIME_ACCOUNTING 1077 u64 prev_steal_time_rq; 1078 #endif 1079 1080 /* calc_load related fields */ 1081 unsigned long calc_load_update; 1082 long calc_load_active; 1083 1084 #ifdef CONFIG_SCHED_HRTICK 1085 #ifdef CONFIG_SMP 1086 call_single_data_t hrtick_csd; 1087 #endif 1088 struct hrtimer hrtick_timer; 1089 ktime_t hrtick_time; 1090 #endif 1091 1092 #ifdef CONFIG_SCHEDSTATS 1093 /* latency stats */ 1094 struct sched_info rq_sched_info; 1095 unsigned long long rq_cpu_time; 1096 /* could above be rq->cfs_rq.exec_clock + rq->rt_rq.rt_runtime ? */ 1097 1098 /* sys_sched_yield() stats */ 1099 unsigned int yld_count; 1100 1101 /* schedule() stats */ 1102 unsigned int sched_count; 1103 unsigned int sched_goidle; 1104 1105 /* try_to_wake_up() stats */ 1106 unsigned int ttwu_count; 1107 unsigned int ttwu_local; 1108 #endif 1109 1110 #ifdef CONFIG_CPU_IDLE 1111 /* Must be inspected within a rcu lock section */ 1112 struct cpuidle_state *idle_state; 1113 #endif 1114 1115 #ifdef CONFIG_SMP 1116 unsigned int nr_pinned; 1117 #endif 1118 unsigned int push_busy; 1119 struct cpu_stop_work push_work; 1120 1121 #ifdef CONFIG_SCHED_CORE 1122 /* per rq */ 1123 struct rq *core; 1124 struct task_struct *core_pick; 1125 unsigned int core_enabled; 1126 unsigned int core_sched_seq; 1127 struct rb_root core_tree; 1128 1129 /* shared state -- careful with sched_core_cpu_deactivate() */ 1130 unsigned int core_task_seq; 1131 unsigned int core_pick_seq; 1132 unsigned long core_cookie; 1133 unsigned int core_forceidle_count; 1134 unsigned int core_forceidle_seq; 1135 unsigned int core_forceidle_occupation; 1136 u64 core_forceidle_start; 1137 #endif 1138 1139 /* Scratch cpumask to be temporarily used under rq_lock */ 1140 cpumask_var_t scratch_mask; 1141 1142 #if defined(CONFIG_CFS_BANDWIDTH) && defined(CONFIG_SMP) 1143 call_single_data_t cfsb_csd; 1144 struct list_head cfsb_csd_list; 1145 #endif 1146 }; 1147 1148 #ifdef CONFIG_FAIR_GROUP_SCHED 1149 1150 /* CPU runqueue to which this cfs_rq is attached */ 1151 static inline struct rq *rq_of(struct cfs_rq *cfs_rq) 1152 { 1153 return cfs_rq->rq; 1154 } 1155 1156 #else 1157 1158 static inline struct rq *rq_of(struct cfs_rq *cfs_rq) 1159 { 1160 return container_of(cfs_rq, struct rq, cfs); 1161 } 1162 #endif 1163 1164 static inline int cpu_of(struct rq *rq) 1165 { 1166 #ifdef CONFIG_SMP 1167 return rq->cpu; 1168 #else 1169 return 0; 1170 #endif 1171 } 1172 1173 #define MDF_PUSH 0x01 1174 1175 static inline bool is_migration_disabled(struct task_struct *p) 1176 { 1177 #ifdef CONFIG_SMP 1178 return p->migration_disabled; 1179 #else 1180 return false; 1181 #endif 1182 } 1183 1184 DECLARE_PER_CPU_SHARED_ALIGNED(struct rq, runqueues); 1185 1186 #define cpu_rq(cpu) (&per_cpu(runqueues, (cpu))) 1187 #define this_rq() this_cpu_ptr(&runqueues) 1188 #define task_rq(p) cpu_rq(task_cpu(p)) 1189 #define cpu_curr(cpu) (cpu_rq(cpu)->curr) 1190 #define raw_rq() raw_cpu_ptr(&runqueues) 1191 1192 struct sched_group; 1193 #ifdef CONFIG_SCHED_CORE 1194 static inline struct cpumask *sched_group_span(struct sched_group *sg); 1195 1196 DECLARE_STATIC_KEY_FALSE(__sched_core_enabled); 1197 1198 static inline bool sched_core_enabled(struct rq *rq) 1199 { 1200 return static_branch_unlikely(&__sched_core_enabled) && rq->core_enabled; 1201 } 1202 1203 static inline bool sched_core_disabled(void) 1204 { 1205 return !static_branch_unlikely(&__sched_core_enabled); 1206 } 1207 1208 /* 1209 * Be careful with this function; not for general use. The return value isn't 1210 * stable unless you actually hold a relevant rq->__lock. 1211 */ 1212 static inline raw_spinlock_t *rq_lockp(struct rq *rq) 1213 { 1214 if (sched_core_enabled(rq)) 1215 return &rq->core->__lock; 1216 1217 return &rq->__lock; 1218 } 1219 1220 static inline raw_spinlock_t *__rq_lockp(struct rq *rq) 1221 { 1222 if (rq->core_enabled) 1223 return &rq->core->__lock; 1224 1225 return &rq->__lock; 1226 } 1227 1228 bool cfs_prio_less(const struct task_struct *a, const struct task_struct *b, 1229 bool fi); 1230 void task_vruntime_update(struct rq *rq, struct task_struct *p, bool in_fi); 1231 1232 /* 1233 * Helpers to check if the CPU's core cookie matches with the task's cookie 1234 * when core scheduling is enabled. 1235 * A special case is that the task's cookie always matches with CPU's core 1236 * cookie if the CPU is in an idle core. 1237 */ 1238 static inline bool sched_cpu_cookie_match(struct rq *rq, struct task_struct *p) 1239 { 1240 /* Ignore cookie match if core scheduler is not enabled on the CPU. */ 1241 if (!sched_core_enabled(rq)) 1242 return true; 1243 1244 return rq->core->core_cookie == p->core_cookie; 1245 } 1246 1247 static inline bool sched_core_cookie_match(struct rq *rq, struct task_struct *p) 1248 { 1249 bool idle_core = true; 1250 int cpu; 1251 1252 /* Ignore cookie match if core scheduler is not enabled on the CPU. */ 1253 if (!sched_core_enabled(rq)) 1254 return true; 1255 1256 for_each_cpu(cpu, cpu_smt_mask(cpu_of(rq))) { 1257 if (!available_idle_cpu(cpu)) { 1258 idle_core = false; 1259 break; 1260 } 1261 } 1262 1263 /* 1264 * A CPU in an idle core is always the best choice for tasks with 1265 * cookies. 1266 */ 1267 return idle_core || rq->core->core_cookie == p->core_cookie; 1268 } 1269 1270 static inline bool sched_group_cookie_match(struct rq *rq, 1271 struct task_struct *p, 1272 struct sched_group *group) 1273 { 1274 int cpu; 1275 1276 /* Ignore cookie match if core scheduler is not enabled on the CPU. */ 1277 if (!sched_core_enabled(rq)) 1278 return true; 1279 1280 for_each_cpu_and(cpu, sched_group_span(group), p->cpus_ptr) { 1281 if (sched_core_cookie_match(cpu_rq(cpu), p)) 1282 return true; 1283 } 1284 return false; 1285 } 1286 1287 static inline bool sched_core_enqueued(struct task_struct *p) 1288 { 1289 return !RB_EMPTY_NODE(&p->core_node); 1290 } 1291 1292 extern void sched_core_enqueue(struct rq *rq, struct task_struct *p); 1293 extern void sched_core_dequeue(struct rq *rq, struct task_struct *p, int flags); 1294 1295 extern void sched_core_get(void); 1296 extern void sched_core_put(void); 1297 1298 #else /* !CONFIG_SCHED_CORE */ 1299 1300 static inline bool sched_core_enabled(struct rq *rq) 1301 { 1302 return false; 1303 } 1304 1305 static inline bool sched_core_disabled(void) 1306 { 1307 return true; 1308 } 1309 1310 static inline raw_spinlock_t *rq_lockp(struct rq *rq) 1311 { 1312 return &rq->__lock; 1313 } 1314 1315 static inline raw_spinlock_t *__rq_lockp(struct rq *rq) 1316 { 1317 return &rq->__lock; 1318 } 1319 1320 static inline bool sched_cpu_cookie_match(struct rq *rq, struct task_struct *p) 1321 { 1322 return true; 1323 } 1324 1325 static inline bool sched_core_cookie_match(struct rq *rq, struct task_struct *p) 1326 { 1327 return true; 1328 } 1329 1330 static inline bool sched_group_cookie_match(struct rq *rq, 1331 struct task_struct *p, 1332 struct sched_group *group) 1333 { 1334 return true; 1335 } 1336 #endif /* CONFIG_SCHED_CORE */ 1337 1338 static inline void lockdep_assert_rq_held(struct rq *rq) 1339 { 1340 lockdep_assert_held(__rq_lockp(rq)); 1341 } 1342 1343 extern void raw_spin_rq_lock_nested(struct rq *rq, int subclass); 1344 extern bool raw_spin_rq_trylock(struct rq *rq); 1345 extern void raw_spin_rq_unlock(struct rq *rq); 1346 1347 static inline void raw_spin_rq_lock(struct rq *rq) 1348 { 1349 raw_spin_rq_lock_nested(rq, 0); 1350 } 1351 1352 static inline void raw_spin_rq_lock_irq(struct rq *rq) 1353 { 1354 local_irq_disable(); 1355 raw_spin_rq_lock(rq); 1356 } 1357 1358 static inline void raw_spin_rq_unlock_irq(struct rq *rq) 1359 { 1360 raw_spin_rq_unlock(rq); 1361 local_irq_enable(); 1362 } 1363 1364 static inline unsigned long _raw_spin_rq_lock_irqsave(struct rq *rq) 1365 { 1366 unsigned long flags; 1367 local_irq_save(flags); 1368 raw_spin_rq_lock(rq); 1369 return flags; 1370 } 1371 1372 static inline void raw_spin_rq_unlock_irqrestore(struct rq *rq, unsigned long flags) 1373 { 1374 raw_spin_rq_unlock(rq); 1375 local_irq_restore(flags); 1376 } 1377 1378 #define raw_spin_rq_lock_irqsave(rq, flags) \ 1379 do { \ 1380 flags = _raw_spin_rq_lock_irqsave(rq); \ 1381 } while (0) 1382 1383 #ifdef CONFIG_SCHED_SMT 1384 extern void __update_idle_core(struct rq *rq); 1385 1386 static inline void update_idle_core(struct rq *rq) 1387 { 1388 if (static_branch_unlikely(&sched_smt_present)) 1389 __update_idle_core(rq); 1390 } 1391 1392 #else 1393 static inline void update_idle_core(struct rq *rq) { } 1394 #endif 1395 1396 #ifdef CONFIG_FAIR_GROUP_SCHED 1397 static inline struct task_struct *task_of(struct sched_entity *se) 1398 { 1399 SCHED_WARN_ON(!entity_is_task(se)); 1400 return container_of(se, struct task_struct, se); 1401 } 1402 1403 static inline struct cfs_rq *task_cfs_rq(struct task_struct *p) 1404 { 1405 return p->se.cfs_rq; 1406 } 1407 1408 /* runqueue on which this entity is (to be) queued */ 1409 static inline struct cfs_rq *cfs_rq_of(const struct sched_entity *se) 1410 { 1411 return se->cfs_rq; 1412 } 1413 1414 /* runqueue "owned" by this group */ 1415 static inline struct cfs_rq *group_cfs_rq(struct sched_entity *grp) 1416 { 1417 return grp->my_q; 1418 } 1419 1420 #else 1421 1422 #define task_of(_se) container_of(_se, struct task_struct, se) 1423 1424 static inline struct cfs_rq *task_cfs_rq(const struct task_struct *p) 1425 { 1426 return &task_rq(p)->cfs; 1427 } 1428 1429 static inline struct cfs_rq *cfs_rq_of(const struct sched_entity *se) 1430 { 1431 const struct task_struct *p = task_of(se); 1432 struct rq *rq = task_rq(p); 1433 1434 return &rq->cfs; 1435 } 1436 1437 /* runqueue "owned" by this group */ 1438 static inline struct cfs_rq *group_cfs_rq(struct sched_entity *grp) 1439 { 1440 return NULL; 1441 } 1442 #endif 1443 1444 extern void update_rq_clock(struct rq *rq); 1445 1446 /* 1447 * rq::clock_update_flags bits 1448 * 1449 * %RQCF_REQ_SKIP - will request skipping of clock update on the next 1450 * call to __schedule(). This is an optimisation to avoid 1451 * neighbouring rq clock updates. 1452 * 1453 * %RQCF_ACT_SKIP - is set from inside of __schedule() when skipping is 1454 * in effect and calls to update_rq_clock() are being ignored. 1455 * 1456 * %RQCF_UPDATED - is a debug flag that indicates whether a call has been 1457 * made to update_rq_clock() since the last time rq::lock was pinned. 1458 * 1459 * If inside of __schedule(), clock_update_flags will have been 1460 * shifted left (a left shift is a cheap operation for the fast path 1461 * to promote %RQCF_REQ_SKIP to %RQCF_ACT_SKIP), so you must use, 1462 * 1463 * if (rq-clock_update_flags >= RQCF_UPDATED) 1464 * 1465 * to check if %RQCF_UPDATED is set. It'll never be shifted more than 1466 * one position though, because the next rq_unpin_lock() will shift it 1467 * back. 1468 */ 1469 #define RQCF_REQ_SKIP 0x01 1470 #define RQCF_ACT_SKIP 0x02 1471 #define RQCF_UPDATED 0x04 1472 1473 static inline void assert_clock_updated(struct rq *rq) 1474 { 1475 /* 1476 * The only reason for not seeing a clock update since the 1477 * last rq_pin_lock() is if we're currently skipping updates. 1478 */ 1479 SCHED_WARN_ON(rq->clock_update_flags < RQCF_ACT_SKIP); 1480 } 1481 1482 static inline u64 rq_clock(struct rq *rq) 1483 { 1484 lockdep_assert_rq_held(rq); 1485 assert_clock_updated(rq); 1486 1487 return rq->clock; 1488 } 1489 1490 static inline u64 rq_clock_task(struct rq *rq) 1491 { 1492 lockdep_assert_rq_held(rq); 1493 assert_clock_updated(rq); 1494 1495 return rq->clock_task; 1496 } 1497 1498 /** 1499 * By default the decay is the default pelt decay period. 1500 * The decay shift can change the decay period in 1501 * multiples of 32. 1502 * Decay shift Decay period(ms) 1503 * 0 32 1504 * 1 64 1505 * 2 128 1506 * 3 256 1507 * 4 512 1508 */ 1509 extern int sched_thermal_decay_shift; 1510 1511 static inline u64 rq_clock_thermal(struct rq *rq) 1512 { 1513 return rq_clock_task(rq) >> sched_thermal_decay_shift; 1514 } 1515 1516 static inline void rq_clock_skip_update(struct rq *rq) 1517 { 1518 lockdep_assert_rq_held(rq); 1519 rq->clock_update_flags |= RQCF_REQ_SKIP; 1520 } 1521 1522 /* 1523 * See rt task throttling, which is the only time a skip 1524 * request is canceled. 1525 */ 1526 static inline void rq_clock_cancel_skipupdate(struct rq *rq) 1527 { 1528 lockdep_assert_rq_held(rq); 1529 rq->clock_update_flags &= ~RQCF_REQ_SKIP; 1530 } 1531 1532 /* 1533 * During cpu offlining and rq wide unthrottling, we can trigger 1534 * an update_rq_clock() for several cfs and rt runqueues (Typically 1535 * when using list_for_each_entry_*) 1536 * rq_clock_start_loop_update() can be called after updating the clock 1537 * once and before iterating over the list to prevent multiple update. 1538 * After the iterative traversal, we need to call rq_clock_stop_loop_update() 1539 * to clear RQCF_ACT_SKIP of rq->clock_update_flags. 1540 */ 1541 static inline void rq_clock_start_loop_update(struct rq *rq) 1542 { 1543 lockdep_assert_rq_held(rq); 1544 SCHED_WARN_ON(rq->clock_update_flags & RQCF_ACT_SKIP); 1545 rq->clock_update_flags |= RQCF_ACT_SKIP; 1546 } 1547 1548 static inline void rq_clock_stop_loop_update(struct rq *rq) 1549 { 1550 lockdep_assert_rq_held(rq); 1551 rq->clock_update_flags &= ~RQCF_ACT_SKIP; 1552 } 1553 1554 struct rq_flags { 1555 unsigned long flags; 1556 struct pin_cookie cookie; 1557 #ifdef CONFIG_SCHED_DEBUG 1558 /* 1559 * A copy of (rq::clock_update_flags & RQCF_UPDATED) for the 1560 * current pin context is stashed here in case it needs to be 1561 * restored in rq_repin_lock(). 1562 */ 1563 unsigned int clock_update_flags; 1564 #endif 1565 }; 1566 1567 extern struct balance_callback balance_push_callback; 1568 1569 /* 1570 * Lockdep annotation that avoids accidental unlocks; it's like a 1571 * sticky/continuous lockdep_assert_held(). 1572 * 1573 * This avoids code that has access to 'struct rq *rq' (basically everything in 1574 * the scheduler) from accidentally unlocking the rq if they do not also have a 1575 * copy of the (on-stack) 'struct rq_flags rf'. 1576 * 1577 * Also see Documentation/locking/lockdep-design.rst. 1578 */ 1579 static inline void rq_pin_lock(struct rq *rq, struct rq_flags *rf) 1580 { 1581 rf->cookie = lockdep_pin_lock(__rq_lockp(rq)); 1582 1583 #ifdef CONFIG_SCHED_DEBUG 1584 rq->clock_update_flags &= (RQCF_REQ_SKIP|RQCF_ACT_SKIP); 1585 rf->clock_update_flags = 0; 1586 #ifdef CONFIG_SMP 1587 SCHED_WARN_ON(rq->balance_callback && rq->balance_callback != &balance_push_callback); 1588 #endif 1589 #endif 1590 } 1591 1592 static inline void rq_unpin_lock(struct rq *rq, struct rq_flags *rf) 1593 { 1594 #ifdef CONFIG_SCHED_DEBUG 1595 if (rq->clock_update_flags > RQCF_ACT_SKIP) 1596 rf->clock_update_flags = RQCF_UPDATED; 1597 #endif 1598 1599 lockdep_unpin_lock(__rq_lockp(rq), rf->cookie); 1600 } 1601 1602 static inline void rq_repin_lock(struct rq *rq, struct rq_flags *rf) 1603 { 1604 lockdep_repin_lock(__rq_lockp(rq), rf->cookie); 1605 1606 #ifdef CONFIG_SCHED_DEBUG 1607 /* 1608 * Restore the value we stashed in @rf for this pin context. 1609 */ 1610 rq->clock_update_flags |= rf->clock_update_flags; 1611 #endif 1612 } 1613 1614 struct rq *__task_rq_lock(struct task_struct *p, struct rq_flags *rf) 1615 __acquires(rq->lock); 1616 1617 struct rq *task_rq_lock(struct task_struct *p, struct rq_flags *rf) 1618 __acquires(p->pi_lock) 1619 __acquires(rq->lock); 1620 1621 static inline void __task_rq_unlock(struct rq *rq, struct rq_flags *rf) 1622 __releases(rq->lock) 1623 { 1624 rq_unpin_lock(rq, rf); 1625 raw_spin_rq_unlock(rq); 1626 } 1627 1628 static inline void 1629 task_rq_unlock(struct rq *rq, struct task_struct *p, struct rq_flags *rf) 1630 __releases(rq->lock) 1631 __releases(p->pi_lock) 1632 { 1633 rq_unpin_lock(rq, rf); 1634 raw_spin_rq_unlock(rq); 1635 raw_spin_unlock_irqrestore(&p->pi_lock, rf->flags); 1636 } 1637 1638 DEFINE_LOCK_GUARD_1(task_rq_lock, struct task_struct, 1639 _T->rq = task_rq_lock(_T->lock, &_T->rf), 1640 task_rq_unlock(_T->rq, _T->lock, &_T->rf), 1641 struct rq *rq; struct rq_flags rf) 1642 1643 static inline void 1644 rq_lock_irqsave(struct rq *rq, struct rq_flags *rf) 1645 __acquires(rq->lock) 1646 { 1647 raw_spin_rq_lock_irqsave(rq, rf->flags); 1648 rq_pin_lock(rq, rf); 1649 } 1650 1651 static inline void 1652 rq_lock_irq(struct rq *rq, struct rq_flags *rf) 1653 __acquires(rq->lock) 1654 { 1655 raw_spin_rq_lock_irq(rq); 1656 rq_pin_lock(rq, rf); 1657 } 1658 1659 static inline void 1660 rq_lock(struct rq *rq, struct rq_flags *rf) 1661 __acquires(rq->lock) 1662 { 1663 raw_spin_rq_lock(rq); 1664 rq_pin_lock(rq, rf); 1665 } 1666 1667 static inline void 1668 rq_unlock_irqrestore(struct rq *rq, struct rq_flags *rf) 1669 __releases(rq->lock) 1670 { 1671 rq_unpin_lock(rq, rf); 1672 raw_spin_rq_unlock_irqrestore(rq, rf->flags); 1673 } 1674 1675 static inline void 1676 rq_unlock_irq(struct rq *rq, struct rq_flags *rf) 1677 __releases(rq->lock) 1678 { 1679 rq_unpin_lock(rq, rf); 1680 raw_spin_rq_unlock_irq(rq); 1681 } 1682 1683 static inline void 1684 rq_unlock(struct rq *rq, struct rq_flags *rf) 1685 __releases(rq->lock) 1686 { 1687 rq_unpin_lock(rq, rf); 1688 raw_spin_rq_unlock(rq); 1689 } 1690 1691 DEFINE_LOCK_GUARD_1(rq_lock, struct rq, 1692 rq_lock(_T->lock, &_T->rf), 1693 rq_unlock(_T->lock, &_T->rf), 1694 struct rq_flags rf) 1695 1696 DEFINE_LOCK_GUARD_1(rq_lock_irq, struct rq, 1697 rq_lock_irq(_T->lock, &_T->rf), 1698 rq_unlock_irq(_T->lock, &_T->rf), 1699 struct rq_flags rf) 1700 1701 DEFINE_LOCK_GUARD_1(rq_lock_irqsave, struct rq, 1702 rq_lock_irqsave(_T->lock, &_T->rf), 1703 rq_unlock_irqrestore(_T->lock, &_T->rf), 1704 struct rq_flags rf) 1705 1706 static inline struct rq * 1707 this_rq_lock_irq(struct rq_flags *rf) 1708 __acquires(rq->lock) 1709 { 1710 struct rq *rq; 1711 1712 local_irq_disable(); 1713 rq = this_rq(); 1714 rq_lock(rq, rf); 1715 return rq; 1716 } 1717 1718 #ifdef CONFIG_NUMA 1719 enum numa_topology_type { 1720 NUMA_DIRECT, 1721 NUMA_GLUELESS_MESH, 1722 NUMA_BACKPLANE, 1723 }; 1724 extern enum numa_topology_type sched_numa_topology_type; 1725 extern int sched_max_numa_distance; 1726 extern bool find_numa_distance(int distance); 1727 extern void sched_init_numa(int offline_node); 1728 extern void sched_update_numa(int cpu, bool online); 1729 extern void sched_domains_numa_masks_set(unsigned int cpu); 1730 extern void sched_domains_numa_masks_clear(unsigned int cpu); 1731 extern int sched_numa_find_closest(const struct cpumask *cpus, int cpu); 1732 #else 1733 static inline void sched_init_numa(int offline_node) { } 1734 static inline void sched_update_numa(int cpu, bool online) { } 1735 static inline void sched_domains_numa_masks_set(unsigned int cpu) { } 1736 static inline void sched_domains_numa_masks_clear(unsigned int cpu) { } 1737 static inline int sched_numa_find_closest(const struct cpumask *cpus, int cpu) 1738 { 1739 return nr_cpu_ids; 1740 } 1741 #endif 1742 1743 #ifdef CONFIG_NUMA_BALANCING 1744 /* The regions in numa_faults array from task_struct */ 1745 enum numa_faults_stats { 1746 NUMA_MEM = 0, 1747 NUMA_CPU, 1748 NUMA_MEMBUF, 1749 NUMA_CPUBUF 1750 }; 1751 extern void sched_setnuma(struct task_struct *p, int node); 1752 extern int migrate_task_to(struct task_struct *p, int cpu); 1753 extern int migrate_swap(struct task_struct *p, struct task_struct *t, 1754 int cpu, int scpu); 1755 extern void init_numa_balancing(unsigned long clone_flags, struct task_struct *p); 1756 #else 1757 static inline void 1758 init_numa_balancing(unsigned long clone_flags, struct task_struct *p) 1759 { 1760 } 1761 #endif /* CONFIG_NUMA_BALANCING */ 1762 1763 #ifdef CONFIG_SMP 1764 1765 static inline void 1766 queue_balance_callback(struct rq *rq, 1767 struct balance_callback *head, 1768 void (*func)(struct rq *rq)) 1769 { 1770 lockdep_assert_rq_held(rq); 1771 1772 /* 1773 * Don't (re)queue an already queued item; nor queue anything when 1774 * balance_push() is active, see the comment with 1775 * balance_push_callback. 1776 */ 1777 if (unlikely(head->next || rq->balance_callback == &balance_push_callback)) 1778 return; 1779 1780 head->func = func; 1781 head->next = rq->balance_callback; 1782 rq->balance_callback = head; 1783 } 1784 1785 #define rcu_dereference_check_sched_domain(p) \ 1786 rcu_dereference_check((p), \ 1787 lockdep_is_held(&sched_domains_mutex)) 1788 1789 /* 1790 * The domain tree (rq->sd) is protected by RCU's quiescent state transition. 1791 * See destroy_sched_domains: call_rcu for details. 1792 * 1793 * The domain tree of any CPU may only be accessed from within 1794 * preempt-disabled sections. 1795 */ 1796 #define for_each_domain(cpu, __sd) \ 1797 for (__sd = rcu_dereference_check_sched_domain(cpu_rq(cpu)->sd); \ 1798 __sd; __sd = __sd->parent) 1799 1800 /* A mask of all the SD flags that have the SDF_SHARED_CHILD metaflag */ 1801 #define SD_FLAG(name, mflags) (name * !!((mflags) & SDF_SHARED_CHILD)) | 1802 static const unsigned int SD_SHARED_CHILD_MASK = 1803 #include <linux/sched/sd_flags.h> 1804 0; 1805 #undef SD_FLAG 1806 1807 /** 1808 * highest_flag_domain - Return highest sched_domain containing flag. 1809 * @cpu: The CPU whose highest level of sched domain is to 1810 * be returned. 1811 * @flag: The flag to check for the highest sched_domain 1812 * for the given CPU. 1813 * 1814 * Returns the highest sched_domain of a CPU which contains @flag. If @flag has 1815 * the SDF_SHARED_CHILD metaflag, all the children domains also have @flag. 1816 */ 1817 static inline struct sched_domain *highest_flag_domain(int cpu, int flag) 1818 { 1819 struct sched_domain *sd, *hsd = NULL; 1820 1821 for_each_domain(cpu, sd) { 1822 if (sd->flags & flag) { 1823 hsd = sd; 1824 continue; 1825 } 1826 1827 /* 1828 * Stop the search if @flag is known to be shared at lower 1829 * levels. It will not be found further up. 1830 */ 1831 if (flag & SD_SHARED_CHILD_MASK) 1832 break; 1833 } 1834 1835 return hsd; 1836 } 1837 1838 static inline struct sched_domain *lowest_flag_domain(int cpu, int flag) 1839 { 1840 struct sched_domain *sd; 1841 1842 for_each_domain(cpu, sd) { 1843 if (sd->flags & flag) 1844 break; 1845 } 1846 1847 return sd; 1848 } 1849 1850 DECLARE_PER_CPU(struct sched_domain __rcu *, sd_llc); 1851 DECLARE_PER_CPU(int, sd_llc_size); 1852 DECLARE_PER_CPU(int, sd_llc_id); 1853 DECLARE_PER_CPU(int, sd_share_id); 1854 DECLARE_PER_CPU(struct sched_domain_shared __rcu *, sd_llc_shared); 1855 DECLARE_PER_CPU(struct sched_domain __rcu *, sd_numa); 1856 DECLARE_PER_CPU(struct sched_domain __rcu *, sd_asym_packing); 1857 DECLARE_PER_CPU(struct sched_domain __rcu *, sd_asym_cpucapacity); 1858 extern struct static_key_false sched_asym_cpucapacity; 1859 extern struct static_key_false sched_cluster_active; 1860 1861 static __always_inline bool sched_asym_cpucap_active(void) 1862 { 1863 return static_branch_unlikely(&sched_asym_cpucapacity); 1864 } 1865 1866 struct sched_group_capacity { 1867 atomic_t ref; 1868 /* 1869 * CPU capacity of this group, SCHED_CAPACITY_SCALE being max capacity 1870 * for a single CPU. 1871 */ 1872 unsigned long capacity; 1873 unsigned long min_capacity; /* Min per-CPU capacity in group */ 1874 unsigned long max_capacity; /* Max per-CPU capacity in group */ 1875 unsigned long next_update; 1876 int imbalance; /* XXX unrelated to capacity but shared group state */ 1877 1878 #ifdef CONFIG_SCHED_DEBUG 1879 int id; 1880 #endif 1881 1882 unsigned long cpumask[]; /* Balance mask */ 1883 }; 1884 1885 struct sched_group { 1886 struct sched_group *next; /* Must be a circular list */ 1887 atomic_t ref; 1888 1889 unsigned int group_weight; 1890 unsigned int cores; 1891 struct sched_group_capacity *sgc; 1892 int asym_prefer_cpu; /* CPU of highest priority in group */ 1893 int flags; 1894 1895 /* 1896 * The CPUs this group covers. 1897 * 1898 * NOTE: this field is variable length. (Allocated dynamically 1899 * by attaching extra space to the end of the structure, 1900 * depending on how many CPUs the kernel has booted up with) 1901 */ 1902 unsigned long cpumask[]; 1903 }; 1904 1905 static inline struct cpumask *sched_group_span(struct sched_group *sg) 1906 { 1907 return to_cpumask(sg->cpumask); 1908 } 1909 1910 /* 1911 * See build_balance_mask(). 1912 */ 1913 static inline struct cpumask *group_balance_mask(struct sched_group *sg) 1914 { 1915 return to_cpumask(sg->sgc->cpumask); 1916 } 1917 1918 extern int group_balance_cpu(struct sched_group *sg); 1919 1920 #ifdef CONFIG_SCHED_DEBUG 1921 void update_sched_domain_debugfs(void); 1922 void dirty_sched_domain_sysctl(int cpu); 1923 #else 1924 static inline void update_sched_domain_debugfs(void) 1925 { 1926 } 1927 static inline void dirty_sched_domain_sysctl(int cpu) 1928 { 1929 } 1930 #endif 1931 1932 extern int sched_update_scaling(void); 1933 1934 static inline const struct cpumask *task_user_cpus(struct task_struct *p) 1935 { 1936 if (!p->user_cpus_ptr) 1937 return cpu_possible_mask; /* &init_task.cpus_mask */ 1938 return p->user_cpus_ptr; 1939 } 1940 #endif /* CONFIG_SMP */ 1941 1942 #include "stats.h" 1943 1944 #if defined(CONFIG_SCHED_CORE) && defined(CONFIG_SCHEDSTATS) 1945 1946 extern void __sched_core_account_forceidle(struct rq *rq); 1947 1948 static inline void sched_core_account_forceidle(struct rq *rq) 1949 { 1950 if (schedstat_enabled()) 1951 __sched_core_account_forceidle(rq); 1952 } 1953 1954 extern void __sched_core_tick(struct rq *rq); 1955 1956 static inline void sched_core_tick(struct rq *rq) 1957 { 1958 if (sched_core_enabled(rq) && schedstat_enabled()) 1959 __sched_core_tick(rq); 1960 } 1961 1962 #else 1963 1964 static inline void sched_core_account_forceidle(struct rq *rq) {} 1965 1966 static inline void sched_core_tick(struct rq *rq) {} 1967 1968 #endif /* CONFIG_SCHED_CORE && CONFIG_SCHEDSTATS */ 1969 1970 #ifdef CONFIG_CGROUP_SCHED 1971 1972 /* 1973 * Return the group to which this tasks belongs. 1974 * 1975 * We cannot use task_css() and friends because the cgroup subsystem 1976 * changes that value before the cgroup_subsys::attach() method is called, 1977 * therefore we cannot pin it and might observe the wrong value. 1978 * 1979 * The same is true for autogroup's p->signal->autogroup->tg, the autogroup 1980 * core changes this before calling sched_move_task(). 1981 * 1982 * Instead we use a 'copy' which is updated from sched_move_task() while 1983 * holding both task_struct::pi_lock and rq::lock. 1984 */ 1985 static inline struct task_group *task_group(struct task_struct *p) 1986 { 1987 return p->sched_task_group; 1988 } 1989 1990 /* Change a task's cfs_rq and parent entity if it moves across CPUs/groups */ 1991 static inline void set_task_rq(struct task_struct *p, unsigned int cpu) 1992 { 1993 #if defined(CONFIG_FAIR_GROUP_SCHED) || defined(CONFIG_RT_GROUP_SCHED) 1994 struct task_group *tg = task_group(p); 1995 #endif 1996 1997 #ifdef CONFIG_FAIR_GROUP_SCHED 1998 set_task_rq_fair(&p->se, p->se.cfs_rq, tg->cfs_rq[cpu]); 1999 p->se.cfs_rq = tg->cfs_rq[cpu]; 2000 p->se.parent = tg->se[cpu]; 2001 p->se.depth = tg->se[cpu] ? tg->se[cpu]->depth + 1 : 0; 2002 #endif 2003 2004 #ifdef CONFIG_RT_GROUP_SCHED 2005 p->rt.rt_rq = tg->rt_rq[cpu]; 2006 p->rt.parent = tg->rt_se[cpu]; 2007 #endif 2008 } 2009 2010 #else /* CONFIG_CGROUP_SCHED */ 2011 2012 static inline void set_task_rq(struct task_struct *p, unsigned int cpu) { } 2013 static inline struct task_group *task_group(struct task_struct *p) 2014 { 2015 return NULL; 2016 } 2017 2018 #endif /* CONFIG_CGROUP_SCHED */ 2019 2020 static inline void __set_task_cpu(struct task_struct *p, unsigned int cpu) 2021 { 2022 set_task_rq(p, cpu); 2023 #ifdef CONFIG_SMP 2024 /* 2025 * After ->cpu is set up to a new value, task_rq_lock(p, ...) can be 2026 * successfully executed on another CPU. We must ensure that updates of 2027 * per-task data have been completed by this moment. 2028 */ 2029 smp_wmb(); 2030 WRITE_ONCE(task_thread_info(p)->cpu, cpu); 2031 p->wake_cpu = cpu; 2032 #endif 2033 } 2034 2035 /* 2036 * Tunables that become constants when CONFIG_SCHED_DEBUG is off: 2037 */ 2038 #ifdef CONFIG_SCHED_DEBUG 2039 # define const_debug __read_mostly 2040 #else 2041 # define const_debug const 2042 #endif 2043 2044 #define SCHED_FEAT(name, enabled) \ 2045 __SCHED_FEAT_##name , 2046 2047 enum { 2048 #include "features.h" 2049 __SCHED_FEAT_NR, 2050 }; 2051 2052 #undef SCHED_FEAT 2053 2054 #ifdef CONFIG_SCHED_DEBUG 2055 2056 /* 2057 * To support run-time toggling of sched features, all the translation units 2058 * (but core.c) reference the sysctl_sched_features defined in core.c. 2059 */ 2060 extern const_debug unsigned int sysctl_sched_features; 2061 2062 #ifdef CONFIG_JUMP_LABEL 2063 #define SCHED_FEAT(name, enabled) \ 2064 static __always_inline bool static_branch_##name(struct static_key *key) \ 2065 { \ 2066 return static_key_##enabled(key); \ 2067 } 2068 2069 #include "features.h" 2070 #undef SCHED_FEAT 2071 2072 extern struct static_key sched_feat_keys[__SCHED_FEAT_NR]; 2073 #define sched_feat(x) (static_branch_##x(&sched_feat_keys[__SCHED_FEAT_##x])) 2074 2075 #else /* !CONFIG_JUMP_LABEL */ 2076 2077 #define sched_feat(x) (sysctl_sched_features & (1UL << __SCHED_FEAT_##x)) 2078 2079 #endif /* CONFIG_JUMP_LABEL */ 2080 2081 #else /* !SCHED_DEBUG */ 2082 2083 /* 2084 * Each translation unit has its own copy of sysctl_sched_features to allow 2085 * constants propagation at compile time and compiler optimization based on 2086 * features default. 2087 */ 2088 #define SCHED_FEAT(name, enabled) \ 2089 (1UL << __SCHED_FEAT_##name) * enabled | 2090 static const_debug __maybe_unused unsigned int sysctl_sched_features = 2091 #include "features.h" 2092 0; 2093 #undef SCHED_FEAT 2094 2095 #define sched_feat(x) !!(sysctl_sched_features & (1UL << __SCHED_FEAT_##x)) 2096 2097 #endif /* SCHED_DEBUG */ 2098 2099 extern struct static_key_false sched_numa_balancing; 2100 extern struct static_key_false sched_schedstats; 2101 2102 static inline u64 global_rt_period(void) 2103 { 2104 return (u64)sysctl_sched_rt_period * NSEC_PER_USEC; 2105 } 2106 2107 static inline u64 global_rt_runtime(void) 2108 { 2109 if (sysctl_sched_rt_runtime < 0) 2110 return RUNTIME_INF; 2111 2112 return (u64)sysctl_sched_rt_runtime * NSEC_PER_USEC; 2113 } 2114 2115 static inline int task_current(struct rq *rq, struct task_struct *p) 2116 { 2117 return rq->curr == p; 2118 } 2119 2120 static inline int task_on_cpu(struct rq *rq, struct task_struct *p) 2121 { 2122 #ifdef CONFIG_SMP 2123 return p->on_cpu; 2124 #else 2125 return task_current(rq, p); 2126 #endif 2127 } 2128 2129 static inline int task_on_rq_queued(struct task_struct *p) 2130 { 2131 return p->on_rq == TASK_ON_RQ_QUEUED; 2132 } 2133 2134 static inline int task_on_rq_migrating(struct task_struct *p) 2135 { 2136 return READ_ONCE(p->on_rq) == TASK_ON_RQ_MIGRATING; 2137 } 2138 2139 /* Wake flags. The first three directly map to some SD flag value */ 2140 #define WF_EXEC 0x02 /* Wakeup after exec; maps to SD_BALANCE_EXEC */ 2141 #define WF_FORK 0x04 /* Wakeup after fork; maps to SD_BALANCE_FORK */ 2142 #define WF_TTWU 0x08 /* Wakeup; maps to SD_BALANCE_WAKE */ 2143 2144 #define WF_SYNC 0x10 /* Waker goes to sleep after wakeup */ 2145 #define WF_MIGRATED 0x20 /* Internal use, task got migrated */ 2146 #define WF_CURRENT_CPU 0x40 /* Prefer to move the wakee to the current CPU. */ 2147 2148 #ifdef CONFIG_SMP 2149 static_assert(WF_EXEC == SD_BALANCE_EXEC); 2150 static_assert(WF_FORK == SD_BALANCE_FORK); 2151 static_assert(WF_TTWU == SD_BALANCE_WAKE); 2152 #endif 2153 2154 /* 2155 * To aid in avoiding the subversion of "niceness" due to uneven distribution 2156 * of tasks with abnormal "nice" values across CPUs the contribution that 2157 * each task makes to its run queue's load is weighted according to its 2158 * scheduling class and "nice" value. For SCHED_NORMAL tasks this is just a 2159 * scaled version of the new time slice allocation that they receive on time 2160 * slice expiry etc. 2161 */ 2162 2163 #define WEIGHT_IDLEPRIO 3 2164 #define WMULT_IDLEPRIO 1431655765 2165 2166 extern const int sched_prio_to_weight[40]; 2167 extern const u32 sched_prio_to_wmult[40]; 2168 2169 /* 2170 * {de,en}queue flags: 2171 * 2172 * DEQUEUE_SLEEP - task is no longer runnable 2173 * ENQUEUE_WAKEUP - task just became runnable 2174 * 2175 * SAVE/RESTORE - an otherwise spurious dequeue/enqueue, done to ensure tasks 2176 * are in a known state which allows modification. Such pairs 2177 * should preserve as much state as possible. 2178 * 2179 * MOVE - paired with SAVE/RESTORE, explicitly does not preserve the location 2180 * in the runqueue. 2181 * 2182 * ENQUEUE_HEAD - place at front of runqueue (tail if not specified) 2183 * ENQUEUE_REPLENISH - CBS (replenish runtime and postpone deadline) 2184 * ENQUEUE_MIGRATED - the task was migrated during wakeup 2185 * 2186 */ 2187 2188 #define DEQUEUE_SLEEP 0x01 2189 #define DEQUEUE_SAVE 0x02 /* Matches ENQUEUE_RESTORE */ 2190 #define DEQUEUE_MOVE 0x04 /* Matches ENQUEUE_MOVE */ 2191 #define DEQUEUE_NOCLOCK 0x08 /* Matches ENQUEUE_NOCLOCK */ 2192 2193 #define ENQUEUE_WAKEUP 0x01 2194 #define ENQUEUE_RESTORE 0x02 2195 #define ENQUEUE_MOVE 0x04 2196 #define ENQUEUE_NOCLOCK 0x08 2197 2198 #define ENQUEUE_HEAD 0x10 2199 #define ENQUEUE_REPLENISH 0x20 2200 #ifdef CONFIG_SMP 2201 #define ENQUEUE_MIGRATED 0x40 2202 #else 2203 #define ENQUEUE_MIGRATED 0x00 2204 #endif 2205 #define ENQUEUE_INITIAL 0x80 2206 2207 #define RETRY_TASK ((void *)-1UL) 2208 2209 struct affinity_context { 2210 const struct cpumask *new_mask; 2211 struct cpumask *user_mask; 2212 unsigned int flags; 2213 }; 2214 2215 struct sched_class { 2216 2217 #ifdef CONFIG_UCLAMP_TASK 2218 int uclamp_enabled; 2219 #endif 2220 2221 void (*enqueue_task) (struct rq *rq, struct task_struct *p, int flags); 2222 void (*dequeue_task) (struct rq *rq, struct task_struct *p, int flags); 2223 void (*yield_task) (struct rq *rq); 2224 bool (*yield_to_task)(struct rq *rq, struct task_struct *p); 2225 2226 void (*wakeup_preempt)(struct rq *rq, struct task_struct *p, int flags); 2227 2228 struct task_struct *(*pick_next_task)(struct rq *rq); 2229 2230 void (*put_prev_task)(struct rq *rq, struct task_struct *p); 2231 void (*set_next_task)(struct rq *rq, struct task_struct *p, bool first); 2232 2233 #ifdef CONFIG_SMP 2234 int (*balance)(struct rq *rq, struct task_struct *prev, struct rq_flags *rf); 2235 int (*select_task_rq)(struct task_struct *p, int task_cpu, int flags); 2236 2237 struct task_struct * (*pick_task)(struct rq *rq); 2238 2239 void (*migrate_task_rq)(struct task_struct *p, int new_cpu); 2240 2241 void (*task_woken)(struct rq *this_rq, struct task_struct *task); 2242 2243 void (*set_cpus_allowed)(struct task_struct *p, struct affinity_context *ctx); 2244 2245 void (*rq_online)(struct rq *rq); 2246 void (*rq_offline)(struct rq *rq); 2247 2248 struct rq *(*find_lock_rq)(struct task_struct *p, struct rq *rq); 2249 #endif 2250 2251 void (*task_tick)(struct rq *rq, struct task_struct *p, int queued); 2252 void (*task_fork)(struct task_struct *p); 2253 void (*task_dead)(struct task_struct *p); 2254 2255 /* 2256 * The switched_from() call is allowed to drop rq->lock, therefore we 2257 * cannot assume the switched_from/switched_to pair is serialized by 2258 * rq->lock. They are however serialized by p->pi_lock. 2259 */ 2260 void (*switched_from)(struct rq *this_rq, struct task_struct *task); 2261 void (*switched_to) (struct rq *this_rq, struct task_struct *task); 2262 void (*prio_changed) (struct rq *this_rq, struct task_struct *task, 2263 int oldprio); 2264 2265 unsigned int (*get_rr_interval)(struct rq *rq, 2266 struct task_struct *task); 2267 2268 void (*update_curr)(struct rq *rq); 2269 2270 #ifdef CONFIG_FAIR_GROUP_SCHED 2271 void (*task_change_group)(struct task_struct *p); 2272 #endif 2273 2274 #ifdef CONFIG_SCHED_CORE 2275 int (*task_is_throttled)(struct task_struct *p, int cpu); 2276 #endif 2277 }; 2278 2279 static inline void put_prev_task(struct rq *rq, struct task_struct *prev) 2280 { 2281 WARN_ON_ONCE(rq->curr != prev); 2282 prev->sched_class->put_prev_task(rq, prev); 2283 } 2284 2285 static inline void set_next_task(struct rq *rq, struct task_struct *next) 2286 { 2287 next->sched_class->set_next_task(rq, next, false); 2288 } 2289 2290 2291 /* 2292 * Helper to define a sched_class instance; each one is placed in a separate 2293 * section which is ordered by the linker script: 2294 * 2295 * include/asm-generic/vmlinux.lds.h 2296 * 2297 * *CAREFUL* they are laid out in *REVERSE* order!!! 2298 * 2299 * Also enforce alignment on the instance, not the type, to guarantee layout. 2300 */ 2301 #define DEFINE_SCHED_CLASS(name) \ 2302 const struct sched_class name##_sched_class \ 2303 __aligned(__alignof__(struct sched_class)) \ 2304 __section("__" #name "_sched_class") 2305 2306 /* Defined in include/asm-generic/vmlinux.lds.h */ 2307 extern struct sched_class __sched_class_highest[]; 2308 extern struct sched_class __sched_class_lowest[]; 2309 2310 #define for_class_range(class, _from, _to) \ 2311 for (class = (_from); class < (_to); class++) 2312 2313 #define for_each_class(class) \ 2314 for_class_range(class, __sched_class_highest, __sched_class_lowest) 2315 2316 #define sched_class_above(_a, _b) ((_a) < (_b)) 2317 2318 extern const struct sched_class stop_sched_class; 2319 extern const struct sched_class dl_sched_class; 2320 extern const struct sched_class rt_sched_class; 2321 extern const struct sched_class fair_sched_class; 2322 extern const struct sched_class idle_sched_class; 2323 2324 static inline bool sched_stop_runnable(struct rq *rq) 2325 { 2326 return rq->stop && task_on_rq_queued(rq->stop); 2327 } 2328 2329 static inline bool sched_dl_runnable(struct rq *rq) 2330 { 2331 return rq->dl.dl_nr_running > 0; 2332 } 2333 2334 static inline bool sched_rt_runnable(struct rq *rq) 2335 { 2336 return rq->rt.rt_queued > 0; 2337 } 2338 2339 static inline bool sched_fair_runnable(struct rq *rq) 2340 { 2341 return rq->cfs.nr_running > 0; 2342 } 2343 2344 extern struct task_struct *pick_next_task_fair(struct rq *rq, struct task_struct *prev, struct rq_flags *rf); 2345 extern struct task_struct *pick_next_task_idle(struct rq *rq); 2346 2347 #define SCA_CHECK 0x01 2348 #define SCA_MIGRATE_DISABLE 0x02 2349 #define SCA_MIGRATE_ENABLE 0x04 2350 #define SCA_USER 0x08 2351 2352 #ifdef CONFIG_SMP 2353 2354 extern void update_group_capacity(struct sched_domain *sd, int cpu); 2355 2356 extern void trigger_load_balance(struct rq *rq); 2357 2358 extern void set_cpus_allowed_common(struct task_struct *p, struct affinity_context *ctx); 2359 2360 static inline struct task_struct *get_push_task(struct rq *rq) 2361 { 2362 struct task_struct *p = rq->curr; 2363 2364 lockdep_assert_rq_held(rq); 2365 2366 if (rq->push_busy) 2367 return NULL; 2368 2369 if (p->nr_cpus_allowed == 1) 2370 return NULL; 2371 2372 if (p->migration_disabled) 2373 return NULL; 2374 2375 rq->push_busy = true; 2376 return get_task_struct(p); 2377 } 2378 2379 extern int push_cpu_stop(void *arg); 2380 2381 #endif 2382 2383 #ifdef CONFIG_CPU_IDLE 2384 static inline void idle_set_state(struct rq *rq, 2385 struct cpuidle_state *idle_state) 2386 { 2387 rq->idle_state = idle_state; 2388 } 2389 2390 static inline struct cpuidle_state *idle_get_state(struct rq *rq) 2391 { 2392 SCHED_WARN_ON(!rcu_read_lock_held()); 2393 2394 return rq->idle_state; 2395 } 2396 #else 2397 static inline void idle_set_state(struct rq *rq, 2398 struct cpuidle_state *idle_state) 2399 { 2400 } 2401 2402 static inline struct cpuidle_state *idle_get_state(struct rq *rq) 2403 { 2404 return NULL; 2405 } 2406 #endif 2407 2408 extern void schedule_idle(void); 2409 asmlinkage void schedule_user(void); 2410 2411 extern void sysrq_sched_debug_show(void); 2412 extern void sched_init_granularity(void); 2413 extern void update_max_interval(void); 2414 2415 extern void init_sched_dl_class(void); 2416 extern void init_sched_rt_class(void); 2417 extern void init_sched_fair_class(void); 2418 2419 extern void reweight_task(struct task_struct *p, int prio); 2420 2421 extern void resched_curr(struct rq *rq); 2422 extern void resched_cpu(int cpu); 2423 2424 extern struct rt_bandwidth def_rt_bandwidth; 2425 extern void init_rt_bandwidth(struct rt_bandwidth *rt_b, u64 period, u64 runtime); 2426 extern bool sched_rt_bandwidth_account(struct rt_rq *rt_rq); 2427 2428 extern void init_dl_task_timer(struct sched_dl_entity *dl_se); 2429 extern void init_dl_inactive_task_timer(struct sched_dl_entity *dl_se); 2430 2431 #define BW_SHIFT 20 2432 #define BW_UNIT (1 << BW_SHIFT) 2433 #define RATIO_SHIFT 8 2434 #define MAX_BW_BITS (64 - BW_SHIFT) 2435 #define MAX_BW ((1ULL << MAX_BW_BITS) - 1) 2436 unsigned long to_ratio(u64 period, u64 runtime); 2437 2438 extern void init_entity_runnable_average(struct sched_entity *se); 2439 extern void post_init_entity_util_avg(struct task_struct *p); 2440 2441 #ifdef CONFIG_NO_HZ_FULL 2442 extern bool sched_can_stop_tick(struct rq *rq); 2443 extern int __init sched_tick_offload_init(void); 2444 2445 /* 2446 * Tick may be needed by tasks in the runqueue depending on their policy and 2447 * requirements. If tick is needed, lets send the target an IPI to kick it out of 2448 * nohz mode if necessary. 2449 */ 2450 static inline void sched_update_tick_dependency(struct rq *rq) 2451 { 2452 int cpu = cpu_of(rq); 2453 2454 if (!tick_nohz_full_cpu(cpu)) 2455 return; 2456 2457 if (sched_can_stop_tick(rq)) 2458 tick_nohz_dep_clear_cpu(cpu, TICK_DEP_BIT_SCHED); 2459 else 2460 tick_nohz_dep_set_cpu(cpu, TICK_DEP_BIT_SCHED); 2461 } 2462 #else 2463 static inline int sched_tick_offload_init(void) { return 0; } 2464 static inline void sched_update_tick_dependency(struct rq *rq) { } 2465 #endif 2466 2467 static inline void add_nr_running(struct rq *rq, unsigned count) 2468 { 2469 unsigned prev_nr = rq->nr_running; 2470 2471 rq->nr_running = prev_nr + count; 2472 if (trace_sched_update_nr_running_tp_enabled()) { 2473 call_trace_sched_update_nr_running(rq, count); 2474 } 2475 2476 #ifdef CONFIG_SMP 2477 if (prev_nr < 2 && rq->nr_running >= 2) { 2478 if (!READ_ONCE(rq->rd->overload)) 2479 WRITE_ONCE(rq->rd->overload, 1); 2480 } 2481 #endif 2482 2483 sched_update_tick_dependency(rq); 2484 } 2485 2486 static inline void sub_nr_running(struct rq *rq, unsigned count) 2487 { 2488 rq->nr_running -= count; 2489 if (trace_sched_update_nr_running_tp_enabled()) { 2490 call_trace_sched_update_nr_running(rq, -count); 2491 } 2492 2493 /* Check if we still need preemption */ 2494 sched_update_tick_dependency(rq); 2495 } 2496 2497 extern void activate_task(struct rq *rq, struct task_struct *p, int flags); 2498 extern void deactivate_task(struct rq *rq, struct task_struct *p, int flags); 2499 2500 extern void wakeup_preempt(struct rq *rq, struct task_struct *p, int flags); 2501 2502 #ifdef CONFIG_PREEMPT_RT 2503 #define SCHED_NR_MIGRATE_BREAK 8 2504 #else 2505 #define SCHED_NR_MIGRATE_BREAK 32 2506 #endif 2507 2508 extern const_debug unsigned int sysctl_sched_nr_migrate; 2509 extern const_debug unsigned int sysctl_sched_migration_cost; 2510 2511 extern unsigned int sysctl_sched_base_slice; 2512 2513 #ifdef CONFIG_SCHED_DEBUG 2514 extern int sysctl_resched_latency_warn_ms; 2515 extern int sysctl_resched_latency_warn_once; 2516 2517 extern unsigned int sysctl_sched_tunable_scaling; 2518 2519 extern unsigned int sysctl_numa_balancing_scan_delay; 2520 extern unsigned int sysctl_numa_balancing_scan_period_min; 2521 extern unsigned int sysctl_numa_balancing_scan_period_max; 2522 extern unsigned int sysctl_numa_balancing_scan_size; 2523 extern unsigned int sysctl_numa_balancing_hot_threshold; 2524 #endif 2525 2526 #ifdef CONFIG_SCHED_HRTICK 2527 2528 /* 2529 * Use hrtick when: 2530 * - enabled by features 2531 * - hrtimer is actually high res 2532 */ 2533 static inline int hrtick_enabled(struct rq *rq) 2534 { 2535 if (!cpu_active(cpu_of(rq))) 2536 return 0; 2537 return hrtimer_is_hres_active(&rq->hrtick_timer); 2538 } 2539 2540 static inline int hrtick_enabled_fair(struct rq *rq) 2541 { 2542 if (!sched_feat(HRTICK)) 2543 return 0; 2544 return hrtick_enabled(rq); 2545 } 2546 2547 static inline int hrtick_enabled_dl(struct rq *rq) 2548 { 2549 if (!sched_feat(HRTICK_DL)) 2550 return 0; 2551 return hrtick_enabled(rq); 2552 } 2553 2554 void hrtick_start(struct rq *rq, u64 delay); 2555 2556 #else 2557 2558 static inline int hrtick_enabled_fair(struct rq *rq) 2559 { 2560 return 0; 2561 } 2562 2563 static inline int hrtick_enabled_dl(struct rq *rq) 2564 { 2565 return 0; 2566 } 2567 2568 static inline int hrtick_enabled(struct rq *rq) 2569 { 2570 return 0; 2571 } 2572 2573 #endif /* CONFIG_SCHED_HRTICK */ 2574 2575 #ifndef arch_scale_freq_tick 2576 static __always_inline 2577 void arch_scale_freq_tick(void) 2578 { 2579 } 2580 #endif 2581 2582 #ifndef arch_scale_freq_capacity 2583 /** 2584 * arch_scale_freq_capacity - get the frequency scale factor of a given CPU. 2585 * @cpu: the CPU in question. 2586 * 2587 * Return: the frequency scale factor normalized against SCHED_CAPACITY_SCALE, i.e. 2588 * 2589 * f_curr 2590 * ------ * SCHED_CAPACITY_SCALE 2591 * f_max 2592 */ 2593 static __always_inline 2594 unsigned long arch_scale_freq_capacity(int cpu) 2595 { 2596 return SCHED_CAPACITY_SCALE; 2597 } 2598 #endif 2599 2600 #ifdef CONFIG_SCHED_DEBUG 2601 /* 2602 * In double_lock_balance()/double_rq_lock(), we use raw_spin_rq_lock() to 2603 * acquire rq lock instead of rq_lock(). So at the end of these two functions 2604 * we need to call double_rq_clock_clear_update() to clear RQCF_UPDATED of 2605 * rq->clock_update_flags to avoid the WARN_DOUBLE_CLOCK warning. 2606 */ 2607 static inline void double_rq_clock_clear_update(struct rq *rq1, struct rq *rq2) 2608 { 2609 rq1->clock_update_flags &= (RQCF_REQ_SKIP|RQCF_ACT_SKIP); 2610 /* rq1 == rq2 for !CONFIG_SMP, so just clear RQCF_UPDATED once. */ 2611 #ifdef CONFIG_SMP 2612 rq2->clock_update_flags &= (RQCF_REQ_SKIP|RQCF_ACT_SKIP); 2613 #endif 2614 } 2615 #else 2616 static inline void double_rq_clock_clear_update(struct rq *rq1, struct rq *rq2) {} 2617 #endif 2618 2619 #define DEFINE_LOCK_GUARD_2(name, type, _lock, _unlock, ...) \ 2620 __DEFINE_UNLOCK_GUARD(name, type, _unlock, type *lock2; __VA_ARGS__) \ 2621 static inline class_##name##_t class_##name##_constructor(type *lock, type *lock2) \ 2622 { class_##name##_t _t = { .lock = lock, .lock2 = lock2 }, *_T = &_t; \ 2623 _lock; return _t; } 2624 2625 #ifdef CONFIG_SMP 2626 2627 static inline bool rq_order_less(struct rq *rq1, struct rq *rq2) 2628 { 2629 #ifdef CONFIG_SCHED_CORE 2630 /* 2631 * In order to not have {0,2},{1,3} turn into into an AB-BA, 2632 * order by core-id first and cpu-id second. 2633 * 2634 * Notably: 2635 * 2636 * double_rq_lock(0,3); will take core-0, core-1 lock 2637 * double_rq_lock(1,2); will take core-1, core-0 lock 2638 * 2639 * when only cpu-id is considered. 2640 */ 2641 if (rq1->core->cpu < rq2->core->cpu) 2642 return true; 2643 if (rq1->core->cpu > rq2->core->cpu) 2644 return false; 2645 2646 /* 2647 * __sched_core_flip() relies on SMT having cpu-id lock order. 2648 */ 2649 #endif 2650 return rq1->cpu < rq2->cpu; 2651 } 2652 2653 extern void double_rq_lock(struct rq *rq1, struct rq *rq2); 2654 2655 #ifdef CONFIG_PREEMPTION 2656 2657 /* 2658 * fair double_lock_balance: Safely acquires both rq->locks in a fair 2659 * way at the expense of forcing extra atomic operations in all 2660 * invocations. This assures that the double_lock is acquired using the 2661 * same underlying policy as the spinlock_t on this architecture, which 2662 * reduces latency compared to the unfair variant below. However, it 2663 * also adds more overhead and therefore may reduce throughput. 2664 */ 2665 static inline int _double_lock_balance(struct rq *this_rq, struct rq *busiest) 2666 __releases(this_rq->lock) 2667 __acquires(busiest->lock) 2668 __acquires(this_rq->lock) 2669 { 2670 raw_spin_rq_unlock(this_rq); 2671 double_rq_lock(this_rq, busiest); 2672 2673 return 1; 2674 } 2675 2676 #else 2677 /* 2678 * Unfair double_lock_balance: Optimizes throughput at the expense of 2679 * latency by eliminating extra atomic operations when the locks are 2680 * already in proper order on entry. This favors lower CPU-ids and will 2681 * grant the double lock to lower CPUs over higher ids under contention, 2682 * regardless of entry order into the function. 2683 */ 2684 static inline int _double_lock_balance(struct rq *this_rq, struct rq *busiest) 2685 __releases(this_rq->lock) 2686 __acquires(busiest->lock) 2687 __acquires(this_rq->lock) 2688 { 2689 if (__rq_lockp(this_rq) == __rq_lockp(busiest) || 2690 likely(raw_spin_rq_trylock(busiest))) { 2691 double_rq_clock_clear_update(this_rq, busiest); 2692 return 0; 2693 } 2694 2695 if (rq_order_less(this_rq, busiest)) { 2696 raw_spin_rq_lock_nested(busiest, SINGLE_DEPTH_NESTING); 2697 double_rq_clock_clear_update(this_rq, busiest); 2698 return 0; 2699 } 2700 2701 raw_spin_rq_unlock(this_rq); 2702 double_rq_lock(this_rq, busiest); 2703 2704 return 1; 2705 } 2706 2707 #endif /* CONFIG_PREEMPTION */ 2708 2709 /* 2710 * double_lock_balance - lock the busiest runqueue, this_rq is locked already. 2711 */ 2712 static inline int double_lock_balance(struct rq *this_rq, struct rq *busiest) 2713 { 2714 lockdep_assert_irqs_disabled(); 2715 2716 return _double_lock_balance(this_rq, busiest); 2717 } 2718 2719 static inline void double_unlock_balance(struct rq *this_rq, struct rq *busiest) 2720 __releases(busiest->lock) 2721 { 2722 if (__rq_lockp(this_rq) != __rq_lockp(busiest)) 2723 raw_spin_rq_unlock(busiest); 2724 lock_set_subclass(&__rq_lockp(this_rq)->dep_map, 0, _RET_IP_); 2725 } 2726 2727 static inline void double_lock(spinlock_t *l1, spinlock_t *l2) 2728 { 2729 if (l1 > l2) 2730 swap(l1, l2); 2731 2732 spin_lock(l1); 2733 spin_lock_nested(l2, SINGLE_DEPTH_NESTING); 2734 } 2735 2736 static inline void double_lock_irq(spinlock_t *l1, spinlock_t *l2) 2737 { 2738 if (l1 > l2) 2739 swap(l1, l2); 2740 2741 spin_lock_irq(l1); 2742 spin_lock_nested(l2, SINGLE_DEPTH_NESTING); 2743 } 2744 2745 static inline void double_raw_lock(raw_spinlock_t *l1, raw_spinlock_t *l2) 2746 { 2747 if (l1 > l2) 2748 swap(l1, l2); 2749 2750 raw_spin_lock(l1); 2751 raw_spin_lock_nested(l2, SINGLE_DEPTH_NESTING); 2752 } 2753 2754 static inline void double_raw_unlock(raw_spinlock_t *l1, raw_spinlock_t *l2) 2755 { 2756 raw_spin_unlock(l1); 2757 raw_spin_unlock(l2); 2758 } 2759 2760 DEFINE_LOCK_GUARD_2(double_raw_spinlock, raw_spinlock_t, 2761 double_raw_lock(_T->lock, _T->lock2), 2762 double_raw_unlock(_T->lock, _T->lock2)) 2763 2764 /* 2765 * double_rq_unlock - safely unlock two runqueues 2766 * 2767 * Note this does not restore interrupts like task_rq_unlock, 2768 * you need to do so manually after calling. 2769 */ 2770 static inline void double_rq_unlock(struct rq *rq1, struct rq *rq2) 2771 __releases(rq1->lock) 2772 __releases(rq2->lock) 2773 { 2774 if (__rq_lockp(rq1) != __rq_lockp(rq2)) 2775 raw_spin_rq_unlock(rq2); 2776 else 2777 __release(rq2->lock); 2778 raw_spin_rq_unlock(rq1); 2779 } 2780 2781 extern void set_rq_online (struct rq *rq); 2782 extern void set_rq_offline(struct rq *rq); 2783 extern bool sched_smp_initialized; 2784 2785 #else /* CONFIG_SMP */ 2786 2787 /* 2788 * double_rq_lock - safely lock two runqueues 2789 * 2790 * Note this does not disable interrupts like task_rq_lock, 2791 * you need to do so manually before calling. 2792 */ 2793 static inline void double_rq_lock(struct rq *rq1, struct rq *rq2) 2794 __acquires(rq1->lock) 2795 __acquires(rq2->lock) 2796 { 2797 WARN_ON_ONCE(!irqs_disabled()); 2798 WARN_ON_ONCE(rq1 != rq2); 2799 raw_spin_rq_lock(rq1); 2800 __acquire(rq2->lock); /* Fake it out ;) */ 2801 double_rq_clock_clear_update(rq1, rq2); 2802 } 2803 2804 /* 2805 * double_rq_unlock - safely unlock two runqueues 2806 * 2807 * Note this does not restore interrupts like task_rq_unlock, 2808 * you need to do so manually after calling. 2809 */ 2810 static inline void double_rq_unlock(struct rq *rq1, struct rq *rq2) 2811 __releases(rq1->lock) 2812 __releases(rq2->lock) 2813 { 2814 WARN_ON_ONCE(rq1 != rq2); 2815 raw_spin_rq_unlock(rq1); 2816 __release(rq2->lock); 2817 } 2818 2819 #endif 2820 2821 DEFINE_LOCK_GUARD_2(double_rq_lock, struct rq, 2822 double_rq_lock(_T->lock, _T->lock2), 2823 double_rq_unlock(_T->lock, _T->lock2)) 2824 2825 extern struct sched_entity *__pick_first_entity(struct cfs_rq *cfs_rq); 2826 extern struct sched_entity *__pick_last_entity(struct cfs_rq *cfs_rq); 2827 2828 #ifdef CONFIG_SCHED_DEBUG 2829 extern bool sched_debug_verbose; 2830 2831 extern void print_cfs_stats(struct seq_file *m, int cpu); 2832 extern void print_rt_stats(struct seq_file *m, int cpu); 2833 extern void print_dl_stats(struct seq_file *m, int cpu); 2834 extern void print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq); 2835 extern void print_rt_rq(struct seq_file *m, int cpu, struct rt_rq *rt_rq); 2836 extern void print_dl_rq(struct seq_file *m, int cpu, struct dl_rq *dl_rq); 2837 2838 extern void resched_latency_warn(int cpu, u64 latency); 2839 #ifdef CONFIG_NUMA_BALANCING 2840 extern void 2841 show_numa_stats(struct task_struct *p, struct seq_file *m); 2842 extern void 2843 print_numa_stats(struct seq_file *m, int node, unsigned long tsf, 2844 unsigned long tpf, unsigned long gsf, unsigned long gpf); 2845 #endif /* CONFIG_NUMA_BALANCING */ 2846 #else 2847 static inline void resched_latency_warn(int cpu, u64 latency) {} 2848 #endif /* CONFIG_SCHED_DEBUG */ 2849 2850 extern void init_cfs_rq(struct cfs_rq *cfs_rq); 2851 extern void init_rt_rq(struct rt_rq *rt_rq); 2852 extern void init_dl_rq(struct dl_rq *dl_rq); 2853 2854 extern void cfs_bandwidth_usage_inc(void); 2855 extern void cfs_bandwidth_usage_dec(void); 2856 2857 #ifdef CONFIG_NO_HZ_COMMON 2858 #define NOHZ_BALANCE_KICK_BIT 0 2859 #define NOHZ_STATS_KICK_BIT 1 2860 #define NOHZ_NEWILB_KICK_BIT 2 2861 #define NOHZ_NEXT_KICK_BIT 3 2862 2863 /* Run rebalance_domains() */ 2864 #define NOHZ_BALANCE_KICK BIT(NOHZ_BALANCE_KICK_BIT) 2865 /* Update blocked load */ 2866 #define NOHZ_STATS_KICK BIT(NOHZ_STATS_KICK_BIT) 2867 /* Update blocked load when entering idle */ 2868 #define NOHZ_NEWILB_KICK BIT(NOHZ_NEWILB_KICK_BIT) 2869 /* Update nohz.next_balance */ 2870 #define NOHZ_NEXT_KICK BIT(NOHZ_NEXT_KICK_BIT) 2871 2872 #define NOHZ_KICK_MASK (NOHZ_BALANCE_KICK | NOHZ_STATS_KICK | NOHZ_NEXT_KICK) 2873 2874 #define nohz_flags(cpu) (&cpu_rq(cpu)->nohz_flags) 2875 2876 extern void nohz_balance_exit_idle(struct rq *rq); 2877 #else 2878 static inline void nohz_balance_exit_idle(struct rq *rq) { } 2879 #endif 2880 2881 #if defined(CONFIG_SMP) && defined(CONFIG_NO_HZ_COMMON) 2882 extern void nohz_run_idle_balance(int cpu); 2883 #else 2884 static inline void nohz_run_idle_balance(int cpu) { } 2885 #endif 2886 2887 #ifdef CONFIG_IRQ_TIME_ACCOUNTING 2888 struct irqtime { 2889 u64 total; 2890 u64 tick_delta; 2891 u64 irq_start_time; 2892 struct u64_stats_sync sync; 2893 }; 2894 2895 DECLARE_PER_CPU(struct irqtime, cpu_irqtime); 2896 2897 /* 2898 * Returns the irqtime minus the softirq time computed by ksoftirqd. 2899 * Otherwise ksoftirqd's sum_exec_runtime is subtracted its own runtime 2900 * and never move forward. 2901 */ 2902 static inline u64 irq_time_read(int cpu) 2903 { 2904 struct irqtime *irqtime = &per_cpu(cpu_irqtime, cpu); 2905 unsigned int seq; 2906 u64 total; 2907 2908 do { 2909 seq = __u64_stats_fetch_begin(&irqtime->sync); 2910 total = irqtime->total; 2911 } while (__u64_stats_fetch_retry(&irqtime->sync, seq)); 2912 2913 return total; 2914 } 2915 #endif /* CONFIG_IRQ_TIME_ACCOUNTING */ 2916 2917 #ifdef CONFIG_CPU_FREQ 2918 DECLARE_PER_CPU(struct update_util_data __rcu *, cpufreq_update_util_data); 2919 2920 /** 2921 * cpufreq_update_util - Take a note about CPU utilization changes. 2922 * @rq: Runqueue to carry out the update for. 2923 * @flags: Update reason flags. 2924 * 2925 * This function is called by the scheduler on the CPU whose utilization is 2926 * being updated. 2927 * 2928 * It can only be called from RCU-sched read-side critical sections. 2929 * 2930 * The way cpufreq is currently arranged requires it to evaluate the CPU 2931 * performance state (frequency/voltage) on a regular basis to prevent it from 2932 * being stuck in a completely inadequate performance level for too long. 2933 * That is not guaranteed to happen if the updates are only triggered from CFS 2934 * and DL, though, because they may not be coming in if only RT tasks are 2935 * active all the time (or there are RT tasks only). 2936 * 2937 * As a workaround for that issue, this function is called periodically by the 2938 * RT sched class to trigger extra cpufreq updates to prevent it from stalling, 2939 * but that really is a band-aid. Going forward it should be replaced with 2940 * solutions targeted more specifically at RT tasks. 2941 */ 2942 static inline void cpufreq_update_util(struct rq *rq, unsigned int flags) 2943 { 2944 struct update_util_data *data; 2945 2946 data = rcu_dereference_sched(*per_cpu_ptr(&cpufreq_update_util_data, 2947 cpu_of(rq))); 2948 if (data) 2949 data->func(data, rq_clock(rq), flags); 2950 } 2951 #else 2952 static inline void cpufreq_update_util(struct rq *rq, unsigned int flags) {} 2953 #endif /* CONFIG_CPU_FREQ */ 2954 2955 #ifdef arch_scale_freq_capacity 2956 # ifndef arch_scale_freq_invariant 2957 # define arch_scale_freq_invariant() true 2958 # endif 2959 #else 2960 # define arch_scale_freq_invariant() false 2961 #endif 2962 2963 #ifdef CONFIG_SMP 2964 /** 2965 * enum cpu_util_type - CPU utilization type 2966 * @FREQUENCY_UTIL: Utilization used to select frequency 2967 * @ENERGY_UTIL: Utilization used during energy calculation 2968 * 2969 * The utilization signals of all scheduling classes (CFS/RT/DL) and IRQ time 2970 * need to be aggregated differently depending on the usage made of them. This 2971 * enum is used within effective_cpu_util() to differentiate the types of 2972 * utilization expected by the callers, and adjust the aggregation accordingly. 2973 */ 2974 enum cpu_util_type { 2975 FREQUENCY_UTIL, 2976 ENERGY_UTIL, 2977 }; 2978 2979 unsigned long effective_cpu_util(int cpu, unsigned long util_cfs, 2980 enum cpu_util_type type, 2981 struct task_struct *p); 2982 2983 /* 2984 * Verify the fitness of task @p to run on @cpu taking into account the 2985 * CPU original capacity and the runtime/deadline ratio of the task. 2986 * 2987 * The function will return true if the original capacity of @cpu is 2988 * greater than or equal to task's deadline density right shifted by 2989 * (BW_SHIFT - SCHED_CAPACITY_SHIFT) and false otherwise. 2990 */ 2991 static inline bool dl_task_fits_capacity(struct task_struct *p, int cpu) 2992 { 2993 unsigned long cap = arch_scale_cpu_capacity(cpu); 2994 2995 return cap >= p->dl.dl_density >> (BW_SHIFT - SCHED_CAPACITY_SHIFT); 2996 } 2997 2998 static inline unsigned long cpu_bw_dl(struct rq *rq) 2999 { 3000 return (rq->dl.running_bw * SCHED_CAPACITY_SCALE) >> BW_SHIFT; 3001 } 3002 3003 static inline unsigned long cpu_util_dl(struct rq *rq) 3004 { 3005 return READ_ONCE(rq->avg_dl.util_avg); 3006 } 3007 3008 3009 extern unsigned long cpu_util_cfs(int cpu); 3010 extern unsigned long cpu_util_cfs_boost(int cpu); 3011 3012 static inline unsigned long cpu_util_rt(struct rq *rq) 3013 { 3014 return READ_ONCE(rq->avg_rt.util_avg); 3015 } 3016 #endif 3017 3018 #ifdef CONFIG_UCLAMP_TASK 3019 unsigned long uclamp_eff_value(struct task_struct *p, enum uclamp_id clamp_id); 3020 3021 static inline unsigned long uclamp_rq_get(struct rq *rq, 3022 enum uclamp_id clamp_id) 3023 { 3024 return READ_ONCE(rq->uclamp[clamp_id].value); 3025 } 3026 3027 static inline void uclamp_rq_set(struct rq *rq, enum uclamp_id clamp_id, 3028 unsigned int value) 3029 { 3030 WRITE_ONCE(rq->uclamp[clamp_id].value, value); 3031 } 3032 3033 static inline bool uclamp_rq_is_idle(struct rq *rq) 3034 { 3035 return rq->uclamp_flags & UCLAMP_FLAG_IDLE; 3036 } 3037 3038 /** 3039 * uclamp_rq_util_with - clamp @util with @rq and @p effective uclamp values. 3040 * @rq: The rq to clamp against. Must not be NULL. 3041 * @util: The util value to clamp. 3042 * @p: The task to clamp against. Can be NULL if you want to clamp 3043 * against @rq only. 3044 * 3045 * Clamps the passed @util to the max(@rq, @p) effective uclamp values. 3046 * 3047 * If sched_uclamp_used static key is disabled, then just return the util 3048 * without any clamping since uclamp aggregation at the rq level in the fast 3049 * path is disabled, rendering this operation a NOP. 3050 * 3051 * Use uclamp_eff_value() if you don't care about uclamp values at rq level. It 3052 * will return the correct effective uclamp value of the task even if the 3053 * static key is disabled. 3054 */ 3055 static __always_inline 3056 unsigned long uclamp_rq_util_with(struct rq *rq, unsigned long util, 3057 struct task_struct *p) 3058 { 3059 unsigned long min_util = 0; 3060 unsigned long max_util = 0; 3061 3062 if (!static_branch_likely(&sched_uclamp_used)) 3063 return util; 3064 3065 if (p) { 3066 min_util = uclamp_eff_value(p, UCLAMP_MIN); 3067 max_util = uclamp_eff_value(p, UCLAMP_MAX); 3068 3069 /* 3070 * Ignore last runnable task's max clamp, as this task will 3071 * reset it. Similarly, no need to read the rq's min clamp. 3072 */ 3073 if (uclamp_rq_is_idle(rq)) 3074 goto out; 3075 } 3076 3077 min_util = max_t(unsigned long, min_util, uclamp_rq_get(rq, UCLAMP_MIN)); 3078 max_util = max_t(unsigned long, max_util, uclamp_rq_get(rq, UCLAMP_MAX)); 3079 out: 3080 /* 3081 * Since CPU's {min,max}_util clamps are MAX aggregated considering 3082 * RUNNABLE tasks with _different_ clamps, we can end up with an 3083 * inversion. Fix it now when the clamps are applied. 3084 */ 3085 if (unlikely(min_util >= max_util)) 3086 return min_util; 3087 3088 return clamp(util, min_util, max_util); 3089 } 3090 3091 /* Is the rq being capped/throttled by uclamp_max? */ 3092 static inline bool uclamp_rq_is_capped(struct rq *rq) 3093 { 3094 unsigned long rq_util; 3095 unsigned long max_util; 3096 3097 if (!static_branch_likely(&sched_uclamp_used)) 3098 return false; 3099 3100 rq_util = cpu_util_cfs(cpu_of(rq)) + cpu_util_rt(rq); 3101 max_util = READ_ONCE(rq->uclamp[UCLAMP_MAX].value); 3102 3103 return max_util != SCHED_CAPACITY_SCALE && rq_util >= max_util; 3104 } 3105 3106 /* 3107 * When uclamp is compiled in, the aggregation at rq level is 'turned off' 3108 * by default in the fast path and only gets turned on once userspace performs 3109 * an operation that requires it. 3110 * 3111 * Returns true if userspace opted-in to use uclamp and aggregation at rq level 3112 * hence is active. 3113 */ 3114 static inline bool uclamp_is_used(void) 3115 { 3116 return static_branch_likely(&sched_uclamp_used); 3117 } 3118 #else /* CONFIG_UCLAMP_TASK */ 3119 static inline unsigned long uclamp_eff_value(struct task_struct *p, 3120 enum uclamp_id clamp_id) 3121 { 3122 if (clamp_id == UCLAMP_MIN) 3123 return 0; 3124 3125 return SCHED_CAPACITY_SCALE; 3126 } 3127 3128 static inline 3129 unsigned long uclamp_rq_util_with(struct rq *rq, unsigned long util, 3130 struct task_struct *p) 3131 { 3132 return util; 3133 } 3134 3135 static inline bool uclamp_rq_is_capped(struct rq *rq) { return false; } 3136 3137 static inline bool uclamp_is_used(void) 3138 { 3139 return false; 3140 } 3141 3142 static inline unsigned long uclamp_rq_get(struct rq *rq, 3143 enum uclamp_id clamp_id) 3144 { 3145 if (clamp_id == UCLAMP_MIN) 3146 return 0; 3147 3148 return SCHED_CAPACITY_SCALE; 3149 } 3150 3151 static inline void uclamp_rq_set(struct rq *rq, enum uclamp_id clamp_id, 3152 unsigned int value) 3153 { 3154 } 3155 3156 static inline bool uclamp_rq_is_idle(struct rq *rq) 3157 { 3158 return false; 3159 } 3160 #endif /* CONFIG_UCLAMP_TASK */ 3161 3162 #ifdef CONFIG_HAVE_SCHED_AVG_IRQ 3163 static inline unsigned long cpu_util_irq(struct rq *rq) 3164 { 3165 return rq->avg_irq.util_avg; 3166 } 3167 3168 static inline 3169 unsigned long scale_irq_capacity(unsigned long util, unsigned long irq, unsigned long max) 3170 { 3171 util *= (max - irq); 3172 util /= max; 3173 3174 return util; 3175 3176 } 3177 #else 3178 static inline unsigned long cpu_util_irq(struct rq *rq) 3179 { 3180 return 0; 3181 } 3182 3183 static inline 3184 unsigned long scale_irq_capacity(unsigned long util, unsigned long irq, unsigned long max) 3185 { 3186 return util; 3187 } 3188 #endif 3189 3190 #if defined(CONFIG_ENERGY_MODEL) && defined(CONFIG_CPU_FREQ_GOV_SCHEDUTIL) 3191 3192 #define perf_domain_span(pd) (to_cpumask(((pd)->em_pd->cpus))) 3193 3194 DECLARE_STATIC_KEY_FALSE(sched_energy_present); 3195 3196 static inline bool sched_energy_enabled(void) 3197 { 3198 return static_branch_unlikely(&sched_energy_present); 3199 } 3200 3201 extern struct cpufreq_governor schedutil_gov; 3202 3203 #else /* ! (CONFIG_ENERGY_MODEL && CONFIG_CPU_FREQ_GOV_SCHEDUTIL) */ 3204 3205 #define perf_domain_span(pd) NULL 3206 static inline bool sched_energy_enabled(void) { return false; } 3207 3208 #endif /* CONFIG_ENERGY_MODEL && CONFIG_CPU_FREQ_GOV_SCHEDUTIL */ 3209 3210 #ifdef CONFIG_MEMBARRIER 3211 /* 3212 * The scheduler provides memory barriers required by membarrier between: 3213 * - prior user-space memory accesses and store to rq->membarrier_state, 3214 * - store to rq->membarrier_state and following user-space memory accesses. 3215 * In the same way it provides those guarantees around store to rq->curr. 3216 */ 3217 static inline void membarrier_switch_mm(struct rq *rq, 3218 struct mm_struct *prev_mm, 3219 struct mm_struct *next_mm) 3220 { 3221 int membarrier_state; 3222 3223 if (prev_mm == next_mm) 3224 return; 3225 3226 membarrier_state = atomic_read(&next_mm->membarrier_state); 3227 if (READ_ONCE(rq->membarrier_state) == membarrier_state) 3228 return; 3229 3230 WRITE_ONCE(rq->membarrier_state, membarrier_state); 3231 } 3232 #else 3233 static inline void membarrier_switch_mm(struct rq *rq, 3234 struct mm_struct *prev_mm, 3235 struct mm_struct *next_mm) 3236 { 3237 } 3238 #endif 3239 3240 #ifdef CONFIG_SMP 3241 static inline bool is_per_cpu_kthread(struct task_struct *p) 3242 { 3243 if (!(p->flags & PF_KTHREAD)) 3244 return false; 3245 3246 if (p->nr_cpus_allowed != 1) 3247 return false; 3248 3249 return true; 3250 } 3251 #endif 3252 3253 extern void swake_up_all_locked(struct swait_queue_head *q); 3254 extern void __prepare_to_swait(struct swait_queue_head *q, struct swait_queue *wait); 3255 3256 extern int try_to_wake_up(struct task_struct *tsk, unsigned int state, int wake_flags); 3257 3258 #ifdef CONFIG_PREEMPT_DYNAMIC 3259 extern int preempt_dynamic_mode; 3260 extern int sched_dynamic_mode(const char *str); 3261 extern void sched_dynamic_update(int mode); 3262 #endif 3263 3264 static inline void update_current_exec_runtime(struct task_struct *curr, 3265 u64 now, u64 delta_exec) 3266 { 3267 curr->se.sum_exec_runtime += delta_exec; 3268 account_group_exec_runtime(curr, delta_exec); 3269 3270 curr->se.exec_start = now; 3271 cgroup_account_cputime(curr, delta_exec); 3272 } 3273 3274 #ifdef CONFIG_SCHED_MM_CID 3275 3276 #define SCHED_MM_CID_PERIOD_NS (100ULL * 1000000) /* 100ms */ 3277 #define MM_CID_SCAN_DELAY 100 /* 100ms */ 3278 3279 extern raw_spinlock_t cid_lock; 3280 extern int use_cid_lock; 3281 3282 extern void sched_mm_cid_migrate_from(struct task_struct *t); 3283 extern void sched_mm_cid_migrate_to(struct rq *dst_rq, struct task_struct *t); 3284 extern void task_tick_mm_cid(struct rq *rq, struct task_struct *curr); 3285 extern void init_sched_mm_cid(struct task_struct *t); 3286 3287 static inline void __mm_cid_put(struct mm_struct *mm, int cid) 3288 { 3289 if (cid < 0) 3290 return; 3291 cpumask_clear_cpu(cid, mm_cidmask(mm)); 3292 } 3293 3294 /* 3295 * The per-mm/cpu cid can have the MM_CID_LAZY_PUT flag set or transition to 3296 * the MM_CID_UNSET state without holding the rq lock, but the rq lock needs to 3297 * be held to transition to other states. 3298 * 3299 * State transitions synchronized with cmpxchg or try_cmpxchg need to be 3300 * consistent across cpus, which prevents use of this_cpu_cmpxchg. 3301 */ 3302 static inline void mm_cid_put_lazy(struct task_struct *t) 3303 { 3304 struct mm_struct *mm = t->mm; 3305 struct mm_cid __percpu *pcpu_cid = mm->pcpu_cid; 3306 int cid; 3307 3308 lockdep_assert_irqs_disabled(); 3309 cid = __this_cpu_read(pcpu_cid->cid); 3310 if (!mm_cid_is_lazy_put(cid) || 3311 !try_cmpxchg(&this_cpu_ptr(pcpu_cid)->cid, &cid, MM_CID_UNSET)) 3312 return; 3313 __mm_cid_put(mm, mm_cid_clear_lazy_put(cid)); 3314 } 3315 3316 static inline int mm_cid_pcpu_unset(struct mm_struct *mm) 3317 { 3318 struct mm_cid __percpu *pcpu_cid = mm->pcpu_cid; 3319 int cid, res; 3320 3321 lockdep_assert_irqs_disabled(); 3322 cid = __this_cpu_read(pcpu_cid->cid); 3323 for (;;) { 3324 if (mm_cid_is_unset(cid)) 3325 return MM_CID_UNSET; 3326 /* 3327 * Attempt transition from valid or lazy-put to unset. 3328 */ 3329 res = cmpxchg(&this_cpu_ptr(pcpu_cid)->cid, cid, MM_CID_UNSET); 3330 if (res == cid) 3331 break; 3332 cid = res; 3333 } 3334 return cid; 3335 } 3336 3337 static inline void mm_cid_put(struct mm_struct *mm) 3338 { 3339 int cid; 3340 3341 lockdep_assert_irqs_disabled(); 3342 cid = mm_cid_pcpu_unset(mm); 3343 if (cid == MM_CID_UNSET) 3344 return; 3345 __mm_cid_put(mm, mm_cid_clear_lazy_put(cid)); 3346 } 3347 3348 static inline int __mm_cid_try_get(struct mm_struct *mm) 3349 { 3350 struct cpumask *cpumask; 3351 int cid; 3352 3353 cpumask = mm_cidmask(mm); 3354 /* 3355 * Retry finding first zero bit if the mask is temporarily 3356 * filled. This only happens during concurrent remote-clear 3357 * which owns a cid without holding a rq lock. 3358 */ 3359 for (;;) { 3360 cid = cpumask_first_zero(cpumask); 3361 if (cid < nr_cpu_ids) 3362 break; 3363 cpu_relax(); 3364 } 3365 if (cpumask_test_and_set_cpu(cid, cpumask)) 3366 return -1; 3367 return cid; 3368 } 3369 3370 /* 3371 * Save a snapshot of the current runqueue time of this cpu 3372 * with the per-cpu cid value, allowing to estimate how recently it was used. 3373 */ 3374 static inline void mm_cid_snapshot_time(struct rq *rq, struct mm_struct *mm) 3375 { 3376 struct mm_cid *pcpu_cid = per_cpu_ptr(mm->pcpu_cid, cpu_of(rq)); 3377 3378 lockdep_assert_rq_held(rq); 3379 WRITE_ONCE(pcpu_cid->time, rq->clock); 3380 } 3381 3382 static inline int __mm_cid_get(struct rq *rq, struct mm_struct *mm) 3383 { 3384 int cid; 3385 3386 /* 3387 * All allocations (even those using the cid_lock) are lock-free. If 3388 * use_cid_lock is set, hold the cid_lock to perform cid allocation to 3389 * guarantee forward progress. 3390 */ 3391 if (!READ_ONCE(use_cid_lock)) { 3392 cid = __mm_cid_try_get(mm); 3393 if (cid >= 0) 3394 goto end; 3395 raw_spin_lock(&cid_lock); 3396 } else { 3397 raw_spin_lock(&cid_lock); 3398 cid = __mm_cid_try_get(mm); 3399 if (cid >= 0) 3400 goto unlock; 3401 } 3402 3403 /* 3404 * cid concurrently allocated. Retry while forcing following 3405 * allocations to use the cid_lock to ensure forward progress. 3406 */ 3407 WRITE_ONCE(use_cid_lock, 1); 3408 /* 3409 * Set use_cid_lock before allocation. Only care about program order 3410 * because this is only required for forward progress. 3411 */ 3412 barrier(); 3413 /* 3414 * Retry until it succeeds. It is guaranteed to eventually succeed once 3415 * all newcoming allocations observe the use_cid_lock flag set. 3416 */ 3417 do { 3418 cid = __mm_cid_try_get(mm); 3419 cpu_relax(); 3420 } while (cid < 0); 3421 /* 3422 * Allocate before clearing use_cid_lock. Only care about 3423 * program order because this is for forward progress. 3424 */ 3425 barrier(); 3426 WRITE_ONCE(use_cid_lock, 0); 3427 unlock: 3428 raw_spin_unlock(&cid_lock); 3429 end: 3430 mm_cid_snapshot_time(rq, mm); 3431 return cid; 3432 } 3433 3434 static inline int mm_cid_get(struct rq *rq, struct mm_struct *mm) 3435 { 3436 struct mm_cid __percpu *pcpu_cid = mm->pcpu_cid; 3437 struct cpumask *cpumask; 3438 int cid; 3439 3440 lockdep_assert_rq_held(rq); 3441 cpumask = mm_cidmask(mm); 3442 cid = __this_cpu_read(pcpu_cid->cid); 3443 if (mm_cid_is_valid(cid)) { 3444 mm_cid_snapshot_time(rq, mm); 3445 return cid; 3446 } 3447 if (mm_cid_is_lazy_put(cid)) { 3448 if (try_cmpxchg(&this_cpu_ptr(pcpu_cid)->cid, &cid, MM_CID_UNSET)) 3449 __mm_cid_put(mm, mm_cid_clear_lazy_put(cid)); 3450 } 3451 cid = __mm_cid_get(rq, mm); 3452 __this_cpu_write(pcpu_cid->cid, cid); 3453 return cid; 3454 } 3455 3456 static inline void switch_mm_cid(struct rq *rq, 3457 struct task_struct *prev, 3458 struct task_struct *next) 3459 { 3460 /* 3461 * Provide a memory barrier between rq->curr store and load of 3462 * {prev,next}->mm->pcpu_cid[cpu] on rq->curr->mm transition. 3463 * 3464 * Should be adapted if context_switch() is modified. 3465 */ 3466 if (!next->mm) { // to kernel 3467 /* 3468 * user -> kernel transition does not guarantee a barrier, but 3469 * we can use the fact that it performs an atomic operation in 3470 * mmgrab(). 3471 */ 3472 if (prev->mm) // from user 3473 smp_mb__after_mmgrab(); 3474 /* 3475 * kernel -> kernel transition does not change rq->curr->mm 3476 * state. It stays NULL. 3477 */ 3478 } else { // to user 3479 /* 3480 * kernel -> user transition does not provide a barrier 3481 * between rq->curr store and load of {prev,next}->mm->pcpu_cid[cpu]. 3482 * Provide it here. 3483 */ 3484 if (!prev->mm) // from kernel 3485 smp_mb(); 3486 /* 3487 * user -> user transition guarantees a memory barrier through 3488 * switch_mm() when current->mm changes. If current->mm is 3489 * unchanged, no barrier is needed. 3490 */ 3491 } 3492 if (prev->mm_cid_active) { 3493 mm_cid_snapshot_time(rq, prev->mm); 3494 mm_cid_put_lazy(prev); 3495 prev->mm_cid = -1; 3496 } 3497 if (next->mm_cid_active) 3498 next->last_mm_cid = next->mm_cid = mm_cid_get(rq, next->mm); 3499 } 3500 3501 #else 3502 static inline void switch_mm_cid(struct rq *rq, struct task_struct *prev, struct task_struct *next) { } 3503 static inline void sched_mm_cid_migrate_from(struct task_struct *t) { } 3504 static inline void sched_mm_cid_migrate_to(struct rq *dst_rq, struct task_struct *t) { } 3505 static inline void task_tick_mm_cid(struct rq *rq, struct task_struct *curr) { } 3506 static inline void init_sched_mm_cid(struct task_struct *t) { } 3507 #endif 3508 3509 extern u64 avg_vruntime(struct cfs_rq *cfs_rq); 3510 extern int entity_eligible(struct cfs_rq *cfs_rq, struct sched_entity *se); 3511 3512 #endif /* _KERNEL_SCHED_SCHED_H */ 3513