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_CGROUP_SCHED 78 #include <linux/cgroup.h> 79 #include <linux/psi.h> 80 #endif 81 82 #ifdef CONFIG_SCHED_DEBUG 83 # include <linux/static_key.h> 84 #endif 85 86 #ifdef CONFIG_PARAVIRT 87 # include <asm/paravirt.h> 88 # include <asm/paravirt_api_clock.h> 89 #endif 90 91 #include <asm/barrier.h> 92 93 #include "cpupri.h" 94 #include "cpudeadline.h" 95 96 #ifdef CONFIG_SCHED_DEBUG 97 # define SCHED_WARN_ON(x) WARN_ONCE(x, #x) 98 #else 99 # define SCHED_WARN_ON(x) ({ (void)(x), 0; }) 100 #endif 101 102 struct rq; 103 struct cpuidle_state; 104 105 /* task_struct::on_rq states: */ 106 #define TASK_ON_RQ_QUEUED 1 107 #define TASK_ON_RQ_MIGRATING 2 108 109 extern __read_mostly int scheduler_running; 110 111 extern unsigned long calc_load_update; 112 extern atomic_long_t calc_load_tasks; 113 114 extern unsigned int sysctl_sched_child_runs_first; 115 116 extern void calc_global_load_tick(struct rq *this_rq); 117 extern long calc_load_fold_active(struct rq *this_rq, long adjust); 118 119 extern void call_trace_sched_update_nr_running(struct rq *rq, int count); 120 121 extern unsigned int sysctl_sched_rt_period; 122 extern int sysctl_sched_rt_runtime; 123 extern int sched_rr_timeslice; 124 125 /* 126 * Helpers for converting nanosecond timing to jiffy resolution 127 */ 128 #define NS_TO_JIFFIES(TIME) ((unsigned long)(TIME) / (NSEC_PER_SEC / HZ)) 129 130 /* 131 * Increase resolution of nice-level calculations for 64-bit architectures. 132 * The extra resolution improves shares distribution and load balancing of 133 * low-weight task groups (eg. nice +19 on an autogroup), deeper taskgroup 134 * hierarchies, especially on larger systems. This is not a user-visible change 135 * and does not change the user-interface for setting shares/weights. 136 * 137 * We increase resolution only if we have enough bits to allow this increased 138 * resolution (i.e. 64-bit). The costs for increasing resolution when 32-bit 139 * are pretty high and the returns do not justify the increased costs. 140 * 141 * Really only required when CONFIG_FAIR_GROUP_SCHED=y is also set, but to 142 * increase coverage and consistency always enable it on 64-bit platforms. 143 */ 144 #ifdef CONFIG_64BIT 145 # define NICE_0_LOAD_SHIFT (SCHED_FIXEDPOINT_SHIFT + SCHED_FIXEDPOINT_SHIFT) 146 # define scale_load(w) ((w) << SCHED_FIXEDPOINT_SHIFT) 147 # define scale_load_down(w) \ 148 ({ \ 149 unsigned long __w = (w); \ 150 if (__w) \ 151 __w = max(2UL, __w >> SCHED_FIXEDPOINT_SHIFT); \ 152 __w; \ 153 }) 154 #else 155 # define NICE_0_LOAD_SHIFT (SCHED_FIXEDPOINT_SHIFT) 156 # define scale_load(w) (w) 157 # define scale_load_down(w) (w) 158 #endif 159 160 /* 161 * Task weight (visible to users) and its load (invisible to users) have 162 * independent resolution, but they should be well calibrated. We use 163 * scale_load() and scale_load_down(w) to convert between them. The 164 * following must be true: 165 * 166 * scale_load(sched_prio_to_weight[NICE_TO_PRIO(0)-MAX_RT_PRIO]) == NICE_0_LOAD 167 * 168 */ 169 #define NICE_0_LOAD (1L << NICE_0_LOAD_SHIFT) 170 171 /* 172 * Single value that decides SCHED_DEADLINE internal math precision. 173 * 10 -> just above 1us 174 * 9 -> just above 0.5us 175 */ 176 #define DL_SCALE 10 177 178 /* 179 * Single value that denotes runtime == period, ie unlimited time. 180 */ 181 #define RUNTIME_INF ((u64)~0ULL) 182 183 static inline int idle_policy(int policy) 184 { 185 return policy == SCHED_IDLE; 186 } 187 static inline int fair_policy(int policy) 188 { 189 return policy == SCHED_NORMAL || policy == SCHED_BATCH; 190 } 191 192 static inline int rt_policy(int policy) 193 { 194 return policy == SCHED_FIFO || policy == SCHED_RR; 195 } 196 197 static inline int dl_policy(int policy) 198 { 199 return policy == SCHED_DEADLINE; 200 } 201 static inline bool valid_policy(int policy) 202 { 203 return idle_policy(policy) || fair_policy(policy) || 204 rt_policy(policy) || dl_policy(policy); 205 } 206 207 static inline int task_has_idle_policy(struct task_struct *p) 208 { 209 return idle_policy(p->policy); 210 } 211 212 static inline int task_has_rt_policy(struct task_struct *p) 213 { 214 return rt_policy(p->policy); 215 } 216 217 static inline int task_has_dl_policy(struct task_struct *p) 218 { 219 return dl_policy(p->policy); 220 } 221 222 #define cap_scale(v, s) ((v)*(s) >> SCHED_CAPACITY_SHIFT) 223 224 static inline void update_avg(u64 *avg, u64 sample) 225 { 226 s64 diff = sample - *avg; 227 *avg += diff / 8; 228 } 229 230 /* 231 * Shifting a value by an exponent greater *or equal* to the size of said value 232 * is UB; cap at size-1. 233 */ 234 #define shr_bound(val, shift) \ 235 (val >> min_t(typeof(shift), shift, BITS_PER_TYPE(typeof(val)) - 1)) 236 237 /* 238 * !! For sched_setattr_nocheck() (kernel) only !! 239 * 240 * This is actually gross. :( 241 * 242 * It is used to make schedutil kworker(s) higher priority than SCHED_DEADLINE 243 * tasks, but still be able to sleep. We need this on platforms that cannot 244 * atomically change clock frequency. Remove once fast switching will be 245 * available on such platforms. 246 * 247 * SUGOV stands for SchedUtil GOVernor. 248 */ 249 #define SCHED_FLAG_SUGOV 0x10000000 250 251 #define SCHED_DL_FLAGS (SCHED_FLAG_RECLAIM | SCHED_FLAG_DL_OVERRUN | SCHED_FLAG_SUGOV) 252 253 static inline bool dl_entity_is_special(const struct sched_dl_entity *dl_se) 254 { 255 #ifdef CONFIG_CPU_FREQ_GOV_SCHEDUTIL 256 return unlikely(dl_se->flags & SCHED_FLAG_SUGOV); 257 #else 258 return false; 259 #endif 260 } 261 262 /* 263 * Tells if entity @a should preempt entity @b. 264 */ 265 static inline bool dl_entity_preempt(const struct sched_dl_entity *a, 266 const struct sched_dl_entity *b) 267 { 268 return dl_entity_is_special(a) || 269 dl_time_before(a->deadline, b->deadline); 270 } 271 272 /* 273 * This is the priority-queue data structure of the RT scheduling class: 274 */ 275 struct rt_prio_array { 276 DECLARE_BITMAP(bitmap, MAX_RT_PRIO+1); /* include 1 bit for delimiter */ 277 struct list_head queue[MAX_RT_PRIO]; 278 }; 279 280 struct rt_bandwidth { 281 /* nests inside the rq lock: */ 282 raw_spinlock_t rt_runtime_lock; 283 ktime_t rt_period; 284 u64 rt_runtime; 285 struct hrtimer rt_period_timer; 286 unsigned int rt_period_active; 287 }; 288 289 static inline int dl_bandwidth_enabled(void) 290 { 291 return sysctl_sched_rt_runtime >= 0; 292 } 293 294 /* 295 * To keep the bandwidth of -deadline tasks under control 296 * we need some place where: 297 * - store the maximum -deadline bandwidth of each cpu; 298 * - cache the fraction of bandwidth that is currently allocated in 299 * each root domain; 300 * 301 * This is all done in the data structure below. It is similar to the 302 * one used for RT-throttling (rt_bandwidth), with the main difference 303 * that, since here we are only interested in admission control, we 304 * do not decrease any runtime while the group "executes", neither we 305 * need a timer to replenish it. 306 * 307 * With respect to SMP, bandwidth is given on a per root domain basis, 308 * meaning that: 309 * - bw (< 100%) is the deadline bandwidth of each CPU; 310 * - total_bw is the currently allocated bandwidth in each root domain; 311 */ 312 struct dl_bw { 313 raw_spinlock_t lock; 314 u64 bw; 315 u64 total_bw; 316 }; 317 318 extern void init_dl_bw(struct dl_bw *dl_b); 319 extern int sched_dl_global_validate(void); 320 extern void sched_dl_do_global(void); 321 extern int sched_dl_overflow(struct task_struct *p, int policy, const struct sched_attr *attr); 322 extern void __setparam_dl(struct task_struct *p, const struct sched_attr *attr); 323 extern void __getparam_dl(struct task_struct *p, struct sched_attr *attr); 324 extern bool __checkparam_dl(const struct sched_attr *attr); 325 extern bool dl_param_changed(struct task_struct *p, const struct sched_attr *attr); 326 extern int dl_cpuset_cpumask_can_shrink(const struct cpumask *cur, const struct cpumask *trial); 327 extern int dl_bw_check_overflow(int cpu); 328 329 #ifdef CONFIG_CGROUP_SCHED 330 331 struct cfs_rq; 332 struct rt_rq; 333 334 extern struct list_head task_groups; 335 336 struct cfs_bandwidth { 337 #ifdef CONFIG_CFS_BANDWIDTH 338 raw_spinlock_t lock; 339 ktime_t period; 340 u64 quota; 341 u64 runtime; 342 u64 burst; 343 u64 runtime_snap; 344 s64 hierarchical_quota; 345 346 u8 idle; 347 u8 period_active; 348 u8 slack_started; 349 struct hrtimer period_timer; 350 struct hrtimer slack_timer; 351 struct list_head throttled_cfs_rq; 352 353 /* Statistics: */ 354 int nr_periods; 355 int nr_throttled; 356 int nr_burst; 357 u64 throttled_time; 358 u64 burst_time; 359 #endif 360 }; 361 362 /* Task group related information */ 363 struct task_group { 364 struct cgroup_subsys_state css; 365 366 #ifdef CONFIG_FAIR_GROUP_SCHED 367 /* schedulable entities of this group on each CPU */ 368 struct sched_entity **se; 369 /* runqueue "owned" by this group on each CPU */ 370 struct cfs_rq **cfs_rq; 371 unsigned long shares; 372 373 /* A positive value indicates that this is a SCHED_IDLE group. */ 374 int idle; 375 376 #ifdef CONFIG_SMP 377 /* 378 * load_avg can be heavily contended at clock tick time, so put 379 * it in its own cacheline separated from the fields above which 380 * will also be accessed at each tick. 381 */ 382 atomic_long_t load_avg ____cacheline_aligned; 383 #endif 384 #endif 385 386 #ifdef CONFIG_RT_GROUP_SCHED 387 struct sched_rt_entity **rt_se; 388 struct rt_rq **rt_rq; 389 390 struct rt_bandwidth rt_bandwidth; 391 #endif 392 393 struct rcu_head rcu; 394 struct list_head list; 395 396 struct task_group *parent; 397 struct list_head siblings; 398 struct list_head children; 399 400 #ifdef CONFIG_SCHED_AUTOGROUP 401 struct autogroup *autogroup; 402 #endif 403 404 struct cfs_bandwidth cfs_bandwidth; 405 406 #ifdef CONFIG_UCLAMP_TASK_GROUP 407 /* The two decimal precision [%] value requested from user-space */ 408 unsigned int uclamp_pct[UCLAMP_CNT]; 409 /* Clamp values requested for a task group */ 410 struct uclamp_se uclamp_req[UCLAMP_CNT]; 411 /* Effective clamp values used for a task group */ 412 struct uclamp_se uclamp[UCLAMP_CNT]; 413 #endif 414 415 }; 416 417 #ifdef CONFIG_FAIR_GROUP_SCHED 418 #define ROOT_TASK_GROUP_LOAD NICE_0_LOAD 419 420 /* 421 * A weight of 0 or 1 can cause arithmetics problems. 422 * A weight of a cfs_rq is the sum of weights of which entities 423 * are queued on this cfs_rq, so a weight of a entity should not be 424 * too large, so as the shares value of a task group. 425 * (The default weight is 1024 - so there's no practical 426 * limitation from this.) 427 */ 428 #define MIN_SHARES (1UL << 1) 429 #define MAX_SHARES (1UL << 18) 430 #endif 431 432 typedef int (*tg_visitor)(struct task_group *, void *); 433 434 extern int walk_tg_tree_from(struct task_group *from, 435 tg_visitor down, tg_visitor up, void *data); 436 437 /* 438 * Iterate the full tree, calling @down when first entering a node and @up when 439 * leaving it for the final time. 440 * 441 * Caller must hold rcu_lock or sufficient equivalent. 442 */ 443 static inline int walk_tg_tree(tg_visitor down, tg_visitor up, void *data) 444 { 445 return walk_tg_tree_from(&root_task_group, down, up, data); 446 } 447 448 extern int tg_nop(struct task_group *tg, void *data); 449 450 extern void free_fair_sched_group(struct task_group *tg); 451 extern int alloc_fair_sched_group(struct task_group *tg, struct task_group *parent); 452 extern void online_fair_sched_group(struct task_group *tg); 453 extern void unregister_fair_sched_group(struct task_group *tg); 454 extern void init_tg_cfs_entry(struct task_group *tg, struct cfs_rq *cfs_rq, 455 struct sched_entity *se, int cpu, 456 struct sched_entity *parent); 457 extern void init_cfs_bandwidth(struct cfs_bandwidth *cfs_b, struct cfs_bandwidth *parent); 458 459 extern void __refill_cfs_bandwidth_runtime(struct cfs_bandwidth *cfs_b); 460 extern void start_cfs_bandwidth(struct cfs_bandwidth *cfs_b); 461 extern void unthrottle_cfs_rq(struct cfs_rq *cfs_rq); 462 extern bool cfs_task_bw_constrained(struct task_struct *p); 463 464 extern void init_tg_rt_entry(struct task_group *tg, struct rt_rq *rt_rq, 465 struct sched_rt_entity *rt_se, int cpu, 466 struct sched_rt_entity *parent); 467 extern int sched_group_set_rt_runtime(struct task_group *tg, long rt_runtime_us); 468 extern int sched_group_set_rt_period(struct task_group *tg, u64 rt_period_us); 469 extern long sched_group_rt_runtime(struct task_group *tg); 470 extern long sched_group_rt_period(struct task_group *tg); 471 extern int sched_rt_can_attach(struct task_group *tg, struct task_struct *tsk); 472 473 extern struct task_group *sched_create_group(struct task_group *parent); 474 extern void sched_online_group(struct task_group *tg, 475 struct task_group *parent); 476 extern void sched_destroy_group(struct task_group *tg); 477 extern void sched_release_group(struct task_group *tg); 478 479 extern void sched_move_task(struct task_struct *tsk); 480 481 #ifdef CONFIG_FAIR_GROUP_SCHED 482 extern int sched_group_set_shares(struct task_group *tg, unsigned long shares); 483 484 extern int sched_group_set_idle(struct task_group *tg, long idle); 485 486 #ifdef CONFIG_SMP 487 extern void set_task_rq_fair(struct sched_entity *se, 488 struct cfs_rq *prev, struct cfs_rq *next); 489 #else /* !CONFIG_SMP */ 490 static inline void set_task_rq_fair(struct sched_entity *se, 491 struct cfs_rq *prev, struct cfs_rq *next) { } 492 #endif /* CONFIG_SMP */ 493 #endif /* CONFIG_FAIR_GROUP_SCHED */ 494 495 #else /* CONFIG_CGROUP_SCHED */ 496 497 struct cfs_bandwidth { }; 498 static inline bool cfs_task_bw_constrained(struct task_struct *p) { return false; } 499 500 #endif /* CONFIG_CGROUP_SCHED */ 501 502 extern void unregister_rt_sched_group(struct task_group *tg); 503 extern void free_rt_sched_group(struct task_group *tg); 504 extern int alloc_rt_sched_group(struct task_group *tg, struct task_group *parent); 505 506 /* 507 * u64_u32_load/u64_u32_store 508 * 509 * Use a copy of a u64 value to protect against data race. This is only 510 * applicable for 32-bits architectures. 511 */ 512 #ifdef CONFIG_64BIT 513 # define u64_u32_load_copy(var, copy) var 514 # define u64_u32_store_copy(var, copy, val) (var = val) 515 #else 516 # define u64_u32_load_copy(var, copy) \ 517 ({ \ 518 u64 __val, __val_copy; \ 519 do { \ 520 __val_copy = copy; \ 521 /* \ 522 * paired with u64_u32_store_copy(), ordering access \ 523 * to var and copy. \ 524 */ \ 525 smp_rmb(); \ 526 __val = var; \ 527 } while (__val != __val_copy); \ 528 __val; \ 529 }) 530 # define u64_u32_store_copy(var, copy, val) \ 531 do { \ 532 typeof(val) __val = (val); \ 533 var = __val; \ 534 /* \ 535 * paired with u64_u32_load_copy(), ordering access to var and \ 536 * copy. \ 537 */ \ 538 smp_wmb(); \ 539 copy = __val; \ 540 } while (0) 541 #endif 542 # define u64_u32_load(var) u64_u32_load_copy(var, var##_copy) 543 # define u64_u32_store(var, val) u64_u32_store_copy(var, var##_copy, val) 544 545 /* CFS-related fields in a runqueue */ 546 struct cfs_rq { 547 struct load_weight load; 548 unsigned int nr_running; 549 unsigned int h_nr_running; /* SCHED_{NORMAL,BATCH,IDLE} */ 550 unsigned int idle_nr_running; /* SCHED_IDLE */ 551 unsigned int idle_h_nr_running; /* SCHED_IDLE */ 552 553 s64 avg_vruntime; 554 u64 avg_load; 555 556 u64 exec_clock; 557 u64 min_vruntime; 558 #ifdef CONFIG_SCHED_CORE 559 unsigned int forceidle_seq; 560 u64 min_vruntime_fi; 561 #endif 562 563 #ifndef CONFIG_64BIT 564 u64 min_vruntime_copy; 565 #endif 566 567 struct rb_root_cached tasks_timeline; 568 569 /* 570 * 'curr' points to currently running entity on this cfs_rq. 571 * It is set to NULL otherwise (i.e when none are currently running). 572 */ 573 struct sched_entity *curr; 574 struct sched_entity *next; 575 576 #ifdef CONFIG_SCHED_DEBUG 577 unsigned int nr_spread_over; 578 #endif 579 580 #ifdef CONFIG_SMP 581 /* 582 * CFS load tracking 583 */ 584 struct sched_avg avg; 585 #ifndef CONFIG_64BIT 586 u64 last_update_time_copy; 587 #endif 588 struct { 589 raw_spinlock_t lock ____cacheline_aligned; 590 int nr; 591 unsigned long load_avg; 592 unsigned long util_avg; 593 unsigned long runnable_avg; 594 } removed; 595 596 #ifdef CONFIG_FAIR_GROUP_SCHED 597 unsigned long tg_load_avg_contrib; 598 long propagate; 599 long prop_runnable_sum; 600 601 /* 602 * h_load = weight * f(tg) 603 * 604 * Where f(tg) is the recursive weight fraction assigned to 605 * this group. 606 */ 607 unsigned long h_load; 608 u64 last_h_load_update; 609 struct sched_entity *h_load_next; 610 #endif /* CONFIG_FAIR_GROUP_SCHED */ 611 #endif /* CONFIG_SMP */ 612 613 #ifdef CONFIG_FAIR_GROUP_SCHED 614 struct rq *rq; /* CPU runqueue to which this cfs_rq is attached */ 615 616 /* 617 * leaf cfs_rqs are those that hold tasks (lowest schedulable entity in 618 * a hierarchy). Non-leaf lrqs hold other higher schedulable entities 619 * (like users, containers etc.) 620 * 621 * leaf_cfs_rq_list ties together list of leaf cfs_rq's in a CPU. 622 * This list is used during load balance. 623 */ 624 int on_list; 625 struct list_head leaf_cfs_rq_list; 626 struct task_group *tg; /* group that "owns" this runqueue */ 627 628 /* Locally cached copy of our task_group's idle value */ 629 int idle; 630 631 #ifdef CONFIG_CFS_BANDWIDTH 632 int runtime_enabled; 633 s64 runtime_remaining; 634 635 u64 throttled_pelt_idle; 636 #ifndef CONFIG_64BIT 637 u64 throttled_pelt_idle_copy; 638 #endif 639 u64 throttled_clock; 640 u64 throttled_clock_pelt; 641 u64 throttled_clock_pelt_time; 642 u64 throttled_clock_self; 643 u64 throttled_clock_self_time; 644 int throttled; 645 int throttle_count; 646 struct list_head throttled_list; 647 #ifdef CONFIG_SMP 648 struct list_head throttled_csd_list; 649 #endif 650 #endif /* CONFIG_CFS_BANDWIDTH */ 651 #endif /* CONFIG_FAIR_GROUP_SCHED */ 652 }; 653 654 static inline int rt_bandwidth_enabled(void) 655 { 656 return sysctl_sched_rt_runtime >= 0; 657 } 658 659 /* RT IPI pull logic requires IRQ_WORK */ 660 #if defined(CONFIG_IRQ_WORK) && defined(CONFIG_SMP) 661 # define HAVE_RT_PUSH_IPI 662 #endif 663 664 /* Real-Time classes' related field in a runqueue: */ 665 struct rt_rq { 666 struct rt_prio_array active; 667 unsigned int rt_nr_running; 668 unsigned int rr_nr_running; 669 #if defined CONFIG_SMP || defined CONFIG_RT_GROUP_SCHED 670 struct { 671 int curr; /* highest queued rt task prio */ 672 #ifdef CONFIG_SMP 673 int next; /* next highest */ 674 #endif 675 } highest_prio; 676 #endif 677 #ifdef CONFIG_SMP 678 unsigned int rt_nr_migratory; 679 unsigned int rt_nr_total; 680 int overloaded; 681 struct plist_head pushable_tasks; 682 683 #endif /* CONFIG_SMP */ 684 int rt_queued; 685 686 int rt_throttled; 687 u64 rt_time; 688 u64 rt_runtime; 689 /* Nests inside the rq lock: */ 690 raw_spinlock_t rt_runtime_lock; 691 692 #ifdef CONFIG_RT_GROUP_SCHED 693 unsigned int rt_nr_boosted; 694 695 struct rq *rq; 696 struct task_group *tg; 697 #endif 698 }; 699 700 static inline bool rt_rq_is_runnable(struct rt_rq *rt_rq) 701 { 702 return rt_rq->rt_queued && rt_rq->rt_nr_running; 703 } 704 705 /* Deadline class' related fields in a runqueue */ 706 struct dl_rq { 707 /* runqueue is an rbtree, ordered by deadline */ 708 struct rb_root_cached root; 709 710 unsigned int dl_nr_running; 711 712 #ifdef CONFIG_SMP 713 /* 714 * Deadline values of the currently executing and the 715 * earliest ready task on this rq. Caching these facilitates 716 * the decision whether or not a ready but not running task 717 * should migrate somewhere else. 718 */ 719 struct { 720 u64 curr; 721 u64 next; 722 } earliest_dl; 723 724 unsigned int dl_nr_migratory; 725 int overloaded; 726 727 /* 728 * Tasks on this rq that can be pushed away. They are kept in 729 * an rb-tree, ordered by tasks' deadlines, with caching 730 * of the leftmost (earliest deadline) element. 731 */ 732 struct rb_root_cached pushable_dl_tasks_root; 733 #else 734 struct dl_bw dl_bw; 735 #endif 736 /* 737 * "Active utilization" for this runqueue: increased when a 738 * task wakes up (becomes TASK_RUNNING) and decreased when a 739 * task blocks 740 */ 741 u64 running_bw; 742 743 /* 744 * Utilization of the tasks "assigned" to this runqueue (including 745 * the tasks that are in runqueue and the tasks that executed on this 746 * CPU and blocked). Increased when a task moves to this runqueue, and 747 * decreased when the task moves away (migrates, changes scheduling 748 * policy, or terminates). 749 * This is needed to compute the "inactive utilization" for the 750 * runqueue (inactive utilization = this_bw - running_bw). 751 */ 752 u64 this_bw; 753 u64 extra_bw; 754 755 /* 756 * Maximum available bandwidth for reclaiming by SCHED_FLAG_RECLAIM 757 * tasks of this rq. Used in calculation of reclaimable bandwidth(GRUB). 758 */ 759 u64 max_bw; 760 761 /* 762 * Inverse of the fraction of CPU utilization that can be reclaimed 763 * by the GRUB algorithm. 764 */ 765 u64 bw_ratio; 766 }; 767 768 #ifdef CONFIG_FAIR_GROUP_SCHED 769 /* An entity is a task if it doesn't "own" a runqueue */ 770 #define entity_is_task(se) (!se->my_q) 771 772 static inline void se_update_runnable(struct sched_entity *se) 773 { 774 if (!entity_is_task(se)) 775 se->runnable_weight = se->my_q->h_nr_running; 776 } 777 778 static inline long se_runnable(struct sched_entity *se) 779 { 780 if (entity_is_task(se)) 781 return !!se->on_rq; 782 else 783 return se->runnable_weight; 784 } 785 786 #else 787 #define entity_is_task(se) 1 788 789 static inline void se_update_runnable(struct sched_entity *se) {} 790 791 static inline long se_runnable(struct sched_entity *se) 792 { 793 return !!se->on_rq; 794 } 795 #endif 796 797 #ifdef CONFIG_SMP 798 /* 799 * XXX we want to get rid of these helpers and use the full load resolution. 800 */ 801 static inline long se_weight(struct sched_entity *se) 802 { 803 return scale_load_down(se->load.weight); 804 } 805 806 807 static inline bool sched_asym_prefer(int a, int b) 808 { 809 return arch_asym_cpu_priority(a) > arch_asym_cpu_priority(b); 810 } 811 812 struct perf_domain { 813 struct em_perf_domain *em_pd; 814 struct perf_domain *next; 815 struct rcu_head rcu; 816 }; 817 818 /* Scheduling group status flags */ 819 #define SG_OVERLOAD 0x1 /* More than one runnable task on a CPU. */ 820 #define SG_OVERUTILIZED 0x2 /* One or more CPUs are over-utilized. */ 821 822 /* 823 * We add the notion of a root-domain which will be used to define per-domain 824 * variables. Each exclusive cpuset essentially defines an island domain by 825 * fully partitioning the member CPUs from any other cpuset. Whenever a new 826 * exclusive cpuset is created, we also create and attach a new root-domain 827 * object. 828 * 829 */ 830 struct root_domain { 831 atomic_t refcount; 832 atomic_t rto_count; 833 struct rcu_head rcu; 834 cpumask_var_t span; 835 cpumask_var_t online; 836 837 /* 838 * Indicate pullable load on at least one CPU, e.g: 839 * - More than one runnable task 840 * - Running task is misfit 841 */ 842 int overload; 843 844 /* Indicate one or more cpus over-utilized (tipping point) */ 845 int overutilized; 846 847 /* 848 * The bit corresponding to a CPU gets set here if such CPU has more 849 * than one runnable -deadline task (as it is below for RT tasks). 850 */ 851 cpumask_var_t dlo_mask; 852 atomic_t dlo_count; 853 struct dl_bw dl_bw; 854 struct cpudl cpudl; 855 856 /* 857 * Indicate whether a root_domain's dl_bw has been checked or 858 * updated. It's monotonously increasing value. 859 * 860 * Also, some corner cases, like 'wrap around' is dangerous, but given 861 * that u64 is 'big enough'. So that shouldn't be a concern. 862 */ 863 u64 visit_gen; 864 865 #ifdef HAVE_RT_PUSH_IPI 866 /* 867 * For IPI pull requests, loop across the rto_mask. 868 */ 869 struct irq_work rto_push_work; 870 raw_spinlock_t rto_lock; 871 /* These are only updated and read within rto_lock */ 872 int rto_loop; 873 int rto_cpu; 874 /* These atomics are updated outside of a lock */ 875 atomic_t rto_loop_next; 876 atomic_t rto_loop_start; 877 #endif 878 /* 879 * The "RT overload" flag: it gets set if a CPU has more than 880 * one runnable RT task. 881 */ 882 cpumask_var_t rto_mask; 883 struct cpupri cpupri; 884 885 unsigned long max_cpu_capacity; 886 887 /* 888 * NULL-terminated list of performance domains intersecting with the 889 * CPUs of the rd. Protected by RCU. 890 */ 891 struct perf_domain __rcu *pd; 892 }; 893 894 extern void init_defrootdomain(void); 895 extern int sched_init_domains(const struct cpumask *cpu_map); 896 extern void rq_attach_root(struct rq *rq, struct root_domain *rd); 897 extern void sched_get_rd(struct root_domain *rd); 898 extern void sched_put_rd(struct root_domain *rd); 899 900 #ifdef HAVE_RT_PUSH_IPI 901 extern void rto_push_irq_work_func(struct irq_work *work); 902 #endif 903 #endif /* CONFIG_SMP */ 904 905 #ifdef CONFIG_UCLAMP_TASK 906 /* 907 * struct uclamp_bucket - Utilization clamp bucket 908 * @value: utilization clamp value for tasks on this clamp bucket 909 * @tasks: number of RUNNABLE tasks on this clamp bucket 910 * 911 * Keep track of how many tasks are RUNNABLE for a given utilization 912 * clamp value. 913 */ 914 struct uclamp_bucket { 915 unsigned long value : bits_per(SCHED_CAPACITY_SCALE); 916 unsigned long tasks : BITS_PER_LONG - bits_per(SCHED_CAPACITY_SCALE); 917 }; 918 919 /* 920 * struct uclamp_rq - rq's utilization clamp 921 * @value: currently active clamp values for a rq 922 * @bucket: utilization clamp buckets affecting a rq 923 * 924 * Keep track of RUNNABLE tasks on a rq to aggregate their clamp values. 925 * A clamp value is affecting a rq when there is at least one task RUNNABLE 926 * (or actually running) with that value. 927 * 928 * There are up to UCLAMP_CNT possible different clamp values, currently there 929 * are only two: minimum utilization and maximum utilization. 930 * 931 * All utilization clamping values are MAX aggregated, since: 932 * - for util_min: we want to run the CPU at least at the max of the minimum 933 * utilization required by its currently RUNNABLE tasks. 934 * - for util_max: we want to allow the CPU to run up to the max of the 935 * maximum utilization allowed by its currently RUNNABLE tasks. 936 * 937 * Since on each system we expect only a limited number of different 938 * utilization clamp values (UCLAMP_BUCKETS), use a simple array to track 939 * the metrics required to compute all the per-rq utilization clamp values. 940 */ 941 struct uclamp_rq { 942 unsigned int value; 943 struct uclamp_bucket bucket[UCLAMP_BUCKETS]; 944 }; 945 946 DECLARE_STATIC_KEY_FALSE(sched_uclamp_used); 947 #endif /* CONFIG_UCLAMP_TASK */ 948 949 struct rq; 950 struct balance_callback { 951 struct balance_callback *next; 952 void (*func)(struct rq *rq); 953 }; 954 955 /* 956 * This is the main, per-CPU runqueue data structure. 957 * 958 * Locking rule: those places that want to lock multiple runqueues 959 * (such as the load balancing or the thread migration code), lock 960 * acquire operations must be ordered by ascending &runqueue. 961 */ 962 struct rq { 963 /* runqueue lock: */ 964 raw_spinlock_t __lock; 965 966 /* 967 * nr_running and cpu_load should be in the same cacheline because 968 * remote CPUs use both these fields when doing load calculation. 969 */ 970 unsigned int nr_running; 971 #ifdef CONFIG_NUMA_BALANCING 972 unsigned int nr_numa_running; 973 unsigned int nr_preferred_running; 974 unsigned int numa_migrate_on; 975 #endif 976 #ifdef CONFIG_NO_HZ_COMMON 977 #ifdef CONFIG_SMP 978 unsigned long last_blocked_load_update_tick; 979 unsigned int has_blocked_load; 980 call_single_data_t nohz_csd; 981 #endif /* CONFIG_SMP */ 982 unsigned int nohz_tick_stopped; 983 atomic_t nohz_flags; 984 #endif /* CONFIG_NO_HZ_COMMON */ 985 986 #ifdef CONFIG_SMP 987 unsigned int ttwu_pending; 988 #endif 989 u64 nr_switches; 990 991 #ifdef CONFIG_UCLAMP_TASK 992 /* Utilization clamp values based on CPU's RUNNABLE tasks */ 993 struct uclamp_rq uclamp[UCLAMP_CNT] ____cacheline_aligned; 994 unsigned int uclamp_flags; 995 #define UCLAMP_FLAG_IDLE 0x01 996 #endif 997 998 struct cfs_rq cfs; 999 struct rt_rq rt; 1000 struct dl_rq dl; 1001 1002 #ifdef CONFIG_FAIR_GROUP_SCHED 1003 /* list of leaf cfs_rq on this CPU: */ 1004 struct list_head leaf_cfs_rq_list; 1005 struct list_head *tmp_alone_branch; 1006 #endif /* CONFIG_FAIR_GROUP_SCHED */ 1007 1008 /* 1009 * This is part of a global counter where only the total sum 1010 * over all CPUs matters. A task can increase this counter on 1011 * one CPU and if it got migrated afterwards it may decrease 1012 * it on another CPU. Always updated under the runqueue lock: 1013 */ 1014 unsigned int nr_uninterruptible; 1015 1016 struct task_struct __rcu *curr; 1017 struct task_struct *idle; 1018 struct task_struct *stop; 1019 unsigned long next_balance; 1020 struct mm_struct *prev_mm; 1021 1022 unsigned int clock_update_flags; 1023 u64 clock; 1024 /* Ensure that all clocks are in the same cache line */ 1025 u64 clock_task ____cacheline_aligned; 1026 u64 clock_pelt; 1027 unsigned long lost_idle_time; 1028 u64 clock_pelt_idle; 1029 u64 clock_idle; 1030 #ifndef CONFIG_64BIT 1031 u64 clock_pelt_idle_copy; 1032 u64 clock_idle_copy; 1033 #endif 1034 1035 atomic_t nr_iowait; 1036 1037 #ifdef CONFIG_SCHED_DEBUG 1038 u64 last_seen_need_resched_ns; 1039 int ticks_without_resched; 1040 #endif 1041 1042 #ifdef CONFIG_MEMBARRIER 1043 int membarrier_state; 1044 #endif 1045 1046 #ifdef CONFIG_SMP 1047 struct root_domain *rd; 1048 struct sched_domain __rcu *sd; 1049 1050 unsigned long cpu_capacity; 1051 unsigned long cpu_capacity_orig; 1052 1053 struct balance_callback *balance_callback; 1054 1055 unsigned char nohz_idle_balance; 1056 unsigned char idle_balance; 1057 1058 unsigned long misfit_task_load; 1059 1060 /* For active balancing */ 1061 int active_balance; 1062 int push_cpu; 1063 struct cpu_stop_work active_balance_work; 1064 1065 /* CPU of this runqueue: */ 1066 int cpu; 1067 int online; 1068 1069 struct list_head cfs_tasks; 1070 1071 struct sched_avg avg_rt; 1072 struct sched_avg avg_dl; 1073 #ifdef CONFIG_HAVE_SCHED_AVG_IRQ 1074 struct sched_avg avg_irq; 1075 #endif 1076 #ifdef CONFIG_SCHED_THERMAL_PRESSURE 1077 struct sched_avg avg_thermal; 1078 #endif 1079 u64 idle_stamp; 1080 u64 avg_idle; 1081 1082 unsigned long wake_stamp; 1083 u64 wake_avg_idle; 1084 1085 /* This is used to determine avg_idle's max value */ 1086 u64 max_idle_balance_cost; 1087 1088 #ifdef CONFIG_HOTPLUG_CPU 1089 struct rcuwait hotplug_wait; 1090 #endif 1091 #endif /* CONFIG_SMP */ 1092 1093 #ifdef CONFIG_IRQ_TIME_ACCOUNTING 1094 u64 prev_irq_time; 1095 u64 psi_irq_time; 1096 #endif 1097 #ifdef CONFIG_PARAVIRT 1098 u64 prev_steal_time; 1099 #endif 1100 #ifdef CONFIG_PARAVIRT_TIME_ACCOUNTING 1101 u64 prev_steal_time_rq; 1102 #endif 1103 1104 /* calc_load related fields */ 1105 unsigned long calc_load_update; 1106 long calc_load_active; 1107 1108 #ifdef CONFIG_SCHED_HRTICK 1109 #ifdef CONFIG_SMP 1110 call_single_data_t hrtick_csd; 1111 #endif 1112 struct hrtimer hrtick_timer; 1113 ktime_t hrtick_time; 1114 #endif 1115 1116 #ifdef CONFIG_SCHEDSTATS 1117 /* latency stats */ 1118 struct sched_info rq_sched_info; 1119 unsigned long long rq_cpu_time; 1120 /* could above be rq->cfs_rq.exec_clock + rq->rt_rq.rt_runtime ? */ 1121 1122 /* sys_sched_yield() stats */ 1123 unsigned int yld_count; 1124 1125 /* schedule() stats */ 1126 unsigned int sched_count; 1127 unsigned int sched_goidle; 1128 1129 /* try_to_wake_up() stats */ 1130 unsigned int ttwu_count; 1131 unsigned int ttwu_local; 1132 #endif 1133 1134 #ifdef CONFIG_CPU_IDLE 1135 /* Must be inspected within a rcu lock section */ 1136 struct cpuidle_state *idle_state; 1137 #endif 1138 1139 #ifdef CONFIG_SMP 1140 unsigned int nr_pinned; 1141 #endif 1142 unsigned int push_busy; 1143 struct cpu_stop_work push_work; 1144 1145 #ifdef CONFIG_SCHED_CORE 1146 /* per rq */ 1147 struct rq *core; 1148 struct task_struct *core_pick; 1149 unsigned int core_enabled; 1150 unsigned int core_sched_seq; 1151 struct rb_root core_tree; 1152 1153 /* shared state -- careful with sched_core_cpu_deactivate() */ 1154 unsigned int core_task_seq; 1155 unsigned int core_pick_seq; 1156 unsigned long core_cookie; 1157 unsigned int core_forceidle_count; 1158 unsigned int core_forceidle_seq; 1159 unsigned int core_forceidle_occupation; 1160 u64 core_forceidle_start; 1161 #endif 1162 1163 /* Scratch cpumask to be temporarily used under rq_lock */ 1164 cpumask_var_t scratch_mask; 1165 1166 #if defined(CONFIG_CFS_BANDWIDTH) && defined(CONFIG_SMP) 1167 call_single_data_t cfsb_csd; 1168 struct list_head cfsb_csd_list; 1169 #endif 1170 }; 1171 1172 #ifdef CONFIG_FAIR_GROUP_SCHED 1173 1174 /* CPU runqueue to which this cfs_rq is attached */ 1175 static inline struct rq *rq_of(struct cfs_rq *cfs_rq) 1176 { 1177 return cfs_rq->rq; 1178 } 1179 1180 #else 1181 1182 static inline struct rq *rq_of(struct cfs_rq *cfs_rq) 1183 { 1184 return container_of(cfs_rq, struct rq, cfs); 1185 } 1186 #endif 1187 1188 static inline int cpu_of(struct rq *rq) 1189 { 1190 #ifdef CONFIG_SMP 1191 return rq->cpu; 1192 #else 1193 return 0; 1194 #endif 1195 } 1196 1197 #define MDF_PUSH 0x01 1198 1199 static inline bool is_migration_disabled(struct task_struct *p) 1200 { 1201 #ifdef CONFIG_SMP 1202 return p->migration_disabled; 1203 #else 1204 return false; 1205 #endif 1206 } 1207 1208 DECLARE_PER_CPU_SHARED_ALIGNED(struct rq, runqueues); 1209 1210 #define cpu_rq(cpu) (&per_cpu(runqueues, (cpu))) 1211 #define this_rq() this_cpu_ptr(&runqueues) 1212 #define task_rq(p) cpu_rq(task_cpu(p)) 1213 #define cpu_curr(cpu) (cpu_rq(cpu)->curr) 1214 #define raw_rq() raw_cpu_ptr(&runqueues) 1215 1216 struct sched_group; 1217 #ifdef CONFIG_SCHED_CORE 1218 static inline struct cpumask *sched_group_span(struct sched_group *sg); 1219 1220 DECLARE_STATIC_KEY_FALSE(__sched_core_enabled); 1221 1222 static inline bool sched_core_enabled(struct rq *rq) 1223 { 1224 return static_branch_unlikely(&__sched_core_enabled) && rq->core_enabled; 1225 } 1226 1227 static inline bool sched_core_disabled(void) 1228 { 1229 return !static_branch_unlikely(&__sched_core_enabled); 1230 } 1231 1232 /* 1233 * Be careful with this function; not for general use. The return value isn't 1234 * stable unless you actually hold a relevant rq->__lock. 1235 */ 1236 static inline raw_spinlock_t *rq_lockp(struct rq *rq) 1237 { 1238 if (sched_core_enabled(rq)) 1239 return &rq->core->__lock; 1240 1241 return &rq->__lock; 1242 } 1243 1244 static inline raw_spinlock_t *__rq_lockp(struct rq *rq) 1245 { 1246 if (rq->core_enabled) 1247 return &rq->core->__lock; 1248 1249 return &rq->__lock; 1250 } 1251 1252 bool cfs_prio_less(const struct task_struct *a, const struct task_struct *b, 1253 bool fi); 1254 void task_vruntime_update(struct rq *rq, struct task_struct *p, bool in_fi); 1255 1256 /* 1257 * Helpers to check if the CPU's core cookie matches with the task's cookie 1258 * when core scheduling is enabled. 1259 * A special case is that the task's cookie always matches with CPU's core 1260 * cookie if the CPU is in an idle core. 1261 */ 1262 static inline bool sched_cpu_cookie_match(struct rq *rq, struct task_struct *p) 1263 { 1264 /* Ignore cookie match if core scheduler is not enabled on the CPU. */ 1265 if (!sched_core_enabled(rq)) 1266 return true; 1267 1268 return rq->core->core_cookie == p->core_cookie; 1269 } 1270 1271 static inline bool sched_core_cookie_match(struct rq *rq, struct task_struct *p) 1272 { 1273 bool idle_core = true; 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(cpu, cpu_smt_mask(cpu_of(rq))) { 1281 if (!available_idle_cpu(cpu)) { 1282 idle_core = false; 1283 break; 1284 } 1285 } 1286 1287 /* 1288 * A CPU in an idle core is always the best choice for tasks with 1289 * cookies. 1290 */ 1291 return idle_core || rq->core->core_cookie == p->core_cookie; 1292 } 1293 1294 static inline bool sched_group_cookie_match(struct rq *rq, 1295 struct task_struct *p, 1296 struct sched_group *group) 1297 { 1298 int cpu; 1299 1300 /* Ignore cookie match if core scheduler is not enabled on the CPU. */ 1301 if (!sched_core_enabled(rq)) 1302 return true; 1303 1304 for_each_cpu_and(cpu, sched_group_span(group), p->cpus_ptr) { 1305 if (sched_core_cookie_match(cpu_rq(cpu), p)) 1306 return true; 1307 } 1308 return false; 1309 } 1310 1311 static inline bool sched_core_enqueued(struct task_struct *p) 1312 { 1313 return !RB_EMPTY_NODE(&p->core_node); 1314 } 1315 1316 extern void sched_core_enqueue(struct rq *rq, struct task_struct *p); 1317 extern void sched_core_dequeue(struct rq *rq, struct task_struct *p, int flags); 1318 1319 extern void sched_core_get(void); 1320 extern void sched_core_put(void); 1321 1322 #else /* !CONFIG_SCHED_CORE */ 1323 1324 static inline bool sched_core_enabled(struct rq *rq) 1325 { 1326 return false; 1327 } 1328 1329 static inline bool sched_core_disabled(void) 1330 { 1331 return true; 1332 } 1333 1334 static inline raw_spinlock_t *rq_lockp(struct rq *rq) 1335 { 1336 return &rq->__lock; 1337 } 1338 1339 static inline raw_spinlock_t *__rq_lockp(struct rq *rq) 1340 { 1341 return &rq->__lock; 1342 } 1343 1344 static inline bool sched_cpu_cookie_match(struct rq *rq, struct task_struct *p) 1345 { 1346 return true; 1347 } 1348 1349 static inline bool sched_core_cookie_match(struct rq *rq, struct task_struct *p) 1350 { 1351 return true; 1352 } 1353 1354 static inline bool sched_group_cookie_match(struct rq *rq, 1355 struct task_struct *p, 1356 struct sched_group *group) 1357 { 1358 return true; 1359 } 1360 #endif /* CONFIG_SCHED_CORE */ 1361 1362 static inline void lockdep_assert_rq_held(struct rq *rq) 1363 { 1364 lockdep_assert_held(__rq_lockp(rq)); 1365 } 1366 1367 extern void raw_spin_rq_lock_nested(struct rq *rq, int subclass); 1368 extern bool raw_spin_rq_trylock(struct rq *rq); 1369 extern void raw_spin_rq_unlock(struct rq *rq); 1370 1371 static inline void raw_spin_rq_lock(struct rq *rq) 1372 { 1373 raw_spin_rq_lock_nested(rq, 0); 1374 } 1375 1376 static inline void raw_spin_rq_lock_irq(struct rq *rq) 1377 { 1378 local_irq_disable(); 1379 raw_spin_rq_lock(rq); 1380 } 1381 1382 static inline void raw_spin_rq_unlock_irq(struct rq *rq) 1383 { 1384 raw_spin_rq_unlock(rq); 1385 local_irq_enable(); 1386 } 1387 1388 static inline unsigned long _raw_spin_rq_lock_irqsave(struct rq *rq) 1389 { 1390 unsigned long flags; 1391 local_irq_save(flags); 1392 raw_spin_rq_lock(rq); 1393 return flags; 1394 } 1395 1396 static inline void raw_spin_rq_unlock_irqrestore(struct rq *rq, unsigned long flags) 1397 { 1398 raw_spin_rq_unlock(rq); 1399 local_irq_restore(flags); 1400 } 1401 1402 #define raw_spin_rq_lock_irqsave(rq, flags) \ 1403 do { \ 1404 flags = _raw_spin_rq_lock_irqsave(rq); \ 1405 } while (0) 1406 1407 #ifdef CONFIG_SCHED_SMT 1408 extern void __update_idle_core(struct rq *rq); 1409 1410 static inline void update_idle_core(struct rq *rq) 1411 { 1412 if (static_branch_unlikely(&sched_smt_present)) 1413 __update_idle_core(rq); 1414 } 1415 1416 #else 1417 static inline void update_idle_core(struct rq *rq) { } 1418 #endif 1419 1420 #ifdef CONFIG_FAIR_GROUP_SCHED 1421 static inline struct task_struct *task_of(struct sched_entity *se) 1422 { 1423 SCHED_WARN_ON(!entity_is_task(se)); 1424 return container_of(se, struct task_struct, se); 1425 } 1426 1427 static inline struct cfs_rq *task_cfs_rq(struct task_struct *p) 1428 { 1429 return p->se.cfs_rq; 1430 } 1431 1432 /* runqueue on which this entity is (to be) queued */ 1433 static inline struct cfs_rq *cfs_rq_of(const struct sched_entity *se) 1434 { 1435 return se->cfs_rq; 1436 } 1437 1438 /* runqueue "owned" by this group */ 1439 static inline struct cfs_rq *group_cfs_rq(struct sched_entity *grp) 1440 { 1441 return grp->my_q; 1442 } 1443 1444 #else 1445 1446 #define task_of(_se) container_of(_se, struct task_struct, se) 1447 1448 static inline struct cfs_rq *task_cfs_rq(const struct task_struct *p) 1449 { 1450 return &task_rq(p)->cfs; 1451 } 1452 1453 static inline struct cfs_rq *cfs_rq_of(const struct sched_entity *se) 1454 { 1455 const struct task_struct *p = task_of(se); 1456 struct rq *rq = task_rq(p); 1457 1458 return &rq->cfs; 1459 } 1460 1461 /* runqueue "owned" by this group */ 1462 static inline struct cfs_rq *group_cfs_rq(struct sched_entity *grp) 1463 { 1464 return NULL; 1465 } 1466 #endif 1467 1468 extern void update_rq_clock(struct rq *rq); 1469 1470 /* 1471 * rq::clock_update_flags bits 1472 * 1473 * %RQCF_REQ_SKIP - will request skipping of clock update on the next 1474 * call to __schedule(). This is an optimisation to avoid 1475 * neighbouring rq clock updates. 1476 * 1477 * %RQCF_ACT_SKIP - is set from inside of __schedule() when skipping is 1478 * in effect and calls to update_rq_clock() are being ignored. 1479 * 1480 * %RQCF_UPDATED - is a debug flag that indicates whether a call has been 1481 * made to update_rq_clock() since the last time rq::lock was pinned. 1482 * 1483 * If inside of __schedule(), clock_update_flags will have been 1484 * shifted left (a left shift is a cheap operation for the fast path 1485 * to promote %RQCF_REQ_SKIP to %RQCF_ACT_SKIP), so you must use, 1486 * 1487 * if (rq-clock_update_flags >= RQCF_UPDATED) 1488 * 1489 * to check if %RQCF_UPDATED is set. It'll never be shifted more than 1490 * one position though, because the next rq_unpin_lock() will shift it 1491 * back. 1492 */ 1493 #define RQCF_REQ_SKIP 0x01 1494 #define RQCF_ACT_SKIP 0x02 1495 #define RQCF_UPDATED 0x04 1496 1497 static inline void assert_clock_updated(struct rq *rq) 1498 { 1499 /* 1500 * The only reason for not seeing a clock update since the 1501 * last rq_pin_lock() is if we're currently skipping updates. 1502 */ 1503 SCHED_WARN_ON(rq->clock_update_flags < RQCF_ACT_SKIP); 1504 } 1505 1506 static inline u64 rq_clock(struct rq *rq) 1507 { 1508 lockdep_assert_rq_held(rq); 1509 assert_clock_updated(rq); 1510 1511 return rq->clock; 1512 } 1513 1514 static inline u64 rq_clock_task(struct rq *rq) 1515 { 1516 lockdep_assert_rq_held(rq); 1517 assert_clock_updated(rq); 1518 1519 return rq->clock_task; 1520 } 1521 1522 /** 1523 * By default the decay is the default pelt decay period. 1524 * The decay shift can change the decay period in 1525 * multiples of 32. 1526 * Decay shift Decay period(ms) 1527 * 0 32 1528 * 1 64 1529 * 2 128 1530 * 3 256 1531 * 4 512 1532 */ 1533 extern int sched_thermal_decay_shift; 1534 1535 static inline u64 rq_clock_thermal(struct rq *rq) 1536 { 1537 return rq_clock_task(rq) >> sched_thermal_decay_shift; 1538 } 1539 1540 static inline void rq_clock_skip_update(struct rq *rq) 1541 { 1542 lockdep_assert_rq_held(rq); 1543 rq->clock_update_flags |= RQCF_REQ_SKIP; 1544 } 1545 1546 /* 1547 * See rt task throttling, which is the only time a skip 1548 * request is canceled. 1549 */ 1550 static inline void rq_clock_cancel_skipupdate(struct rq *rq) 1551 { 1552 lockdep_assert_rq_held(rq); 1553 rq->clock_update_flags &= ~RQCF_REQ_SKIP; 1554 } 1555 1556 /* 1557 * During cpu offlining and rq wide unthrottling, we can trigger 1558 * an update_rq_clock() for several cfs and rt runqueues (Typically 1559 * when using list_for_each_entry_*) 1560 * rq_clock_start_loop_update() can be called after updating the clock 1561 * once and before iterating over the list to prevent multiple update. 1562 * After the iterative traversal, we need to call rq_clock_stop_loop_update() 1563 * to clear RQCF_ACT_SKIP of rq->clock_update_flags. 1564 */ 1565 static inline void rq_clock_start_loop_update(struct rq *rq) 1566 { 1567 lockdep_assert_rq_held(rq); 1568 SCHED_WARN_ON(rq->clock_update_flags & RQCF_ACT_SKIP); 1569 rq->clock_update_flags |= RQCF_ACT_SKIP; 1570 } 1571 1572 static inline void rq_clock_stop_loop_update(struct rq *rq) 1573 { 1574 lockdep_assert_rq_held(rq); 1575 rq->clock_update_flags &= ~RQCF_ACT_SKIP; 1576 } 1577 1578 struct rq_flags { 1579 unsigned long flags; 1580 struct pin_cookie cookie; 1581 #ifdef CONFIG_SCHED_DEBUG 1582 /* 1583 * A copy of (rq::clock_update_flags & RQCF_UPDATED) for the 1584 * current pin context is stashed here in case it needs to be 1585 * restored in rq_repin_lock(). 1586 */ 1587 unsigned int clock_update_flags; 1588 #endif 1589 }; 1590 1591 extern struct balance_callback balance_push_callback; 1592 1593 /* 1594 * Lockdep annotation that avoids accidental unlocks; it's like a 1595 * sticky/continuous lockdep_assert_held(). 1596 * 1597 * This avoids code that has access to 'struct rq *rq' (basically everything in 1598 * the scheduler) from accidentally unlocking the rq if they do not also have a 1599 * copy of the (on-stack) 'struct rq_flags rf'. 1600 * 1601 * Also see Documentation/locking/lockdep-design.rst. 1602 */ 1603 static inline void rq_pin_lock(struct rq *rq, struct rq_flags *rf) 1604 { 1605 rf->cookie = lockdep_pin_lock(__rq_lockp(rq)); 1606 1607 #ifdef CONFIG_SCHED_DEBUG 1608 rq->clock_update_flags &= (RQCF_REQ_SKIP|RQCF_ACT_SKIP); 1609 rf->clock_update_flags = 0; 1610 #ifdef CONFIG_SMP 1611 SCHED_WARN_ON(rq->balance_callback && rq->balance_callback != &balance_push_callback); 1612 #endif 1613 #endif 1614 } 1615 1616 static inline void rq_unpin_lock(struct rq *rq, struct rq_flags *rf) 1617 { 1618 #ifdef CONFIG_SCHED_DEBUG 1619 if (rq->clock_update_flags > RQCF_ACT_SKIP) 1620 rf->clock_update_flags = RQCF_UPDATED; 1621 #endif 1622 1623 lockdep_unpin_lock(__rq_lockp(rq), rf->cookie); 1624 } 1625 1626 static inline void rq_repin_lock(struct rq *rq, struct rq_flags *rf) 1627 { 1628 lockdep_repin_lock(__rq_lockp(rq), rf->cookie); 1629 1630 #ifdef CONFIG_SCHED_DEBUG 1631 /* 1632 * Restore the value we stashed in @rf for this pin context. 1633 */ 1634 rq->clock_update_flags |= rf->clock_update_flags; 1635 #endif 1636 } 1637 1638 struct rq *__task_rq_lock(struct task_struct *p, struct rq_flags *rf) 1639 __acquires(rq->lock); 1640 1641 struct rq *task_rq_lock(struct task_struct *p, struct rq_flags *rf) 1642 __acquires(p->pi_lock) 1643 __acquires(rq->lock); 1644 1645 static inline void __task_rq_unlock(struct rq *rq, struct rq_flags *rf) 1646 __releases(rq->lock) 1647 { 1648 rq_unpin_lock(rq, rf); 1649 raw_spin_rq_unlock(rq); 1650 } 1651 1652 static inline void 1653 task_rq_unlock(struct rq *rq, struct task_struct *p, struct rq_flags *rf) 1654 __releases(rq->lock) 1655 __releases(p->pi_lock) 1656 { 1657 rq_unpin_lock(rq, rf); 1658 raw_spin_rq_unlock(rq); 1659 raw_spin_unlock_irqrestore(&p->pi_lock, rf->flags); 1660 } 1661 1662 static inline void 1663 rq_lock_irqsave(struct rq *rq, struct rq_flags *rf) 1664 __acquires(rq->lock) 1665 { 1666 raw_spin_rq_lock_irqsave(rq, rf->flags); 1667 rq_pin_lock(rq, rf); 1668 } 1669 1670 static inline void 1671 rq_lock_irq(struct rq *rq, struct rq_flags *rf) 1672 __acquires(rq->lock) 1673 { 1674 raw_spin_rq_lock_irq(rq); 1675 rq_pin_lock(rq, rf); 1676 } 1677 1678 static inline void 1679 rq_lock(struct rq *rq, struct rq_flags *rf) 1680 __acquires(rq->lock) 1681 { 1682 raw_spin_rq_lock(rq); 1683 rq_pin_lock(rq, rf); 1684 } 1685 1686 static inline void 1687 rq_unlock_irqrestore(struct rq *rq, struct rq_flags *rf) 1688 __releases(rq->lock) 1689 { 1690 rq_unpin_lock(rq, rf); 1691 raw_spin_rq_unlock_irqrestore(rq, rf->flags); 1692 } 1693 1694 static inline void 1695 rq_unlock_irq(struct rq *rq, struct rq_flags *rf) 1696 __releases(rq->lock) 1697 { 1698 rq_unpin_lock(rq, rf); 1699 raw_spin_rq_unlock_irq(rq); 1700 } 1701 1702 static inline void 1703 rq_unlock(struct rq *rq, struct rq_flags *rf) 1704 __releases(rq->lock) 1705 { 1706 rq_unpin_lock(rq, rf); 1707 raw_spin_rq_unlock(rq); 1708 } 1709 1710 DEFINE_LOCK_GUARD_1(rq_lock, struct rq, 1711 rq_lock(_T->lock, &_T->rf), 1712 rq_unlock(_T->lock, &_T->rf), 1713 struct rq_flags rf) 1714 1715 DEFINE_LOCK_GUARD_1(rq_lock_irq, struct rq, 1716 rq_lock_irq(_T->lock, &_T->rf), 1717 rq_unlock_irq(_T->lock, &_T->rf), 1718 struct rq_flags rf) 1719 1720 DEFINE_LOCK_GUARD_1(rq_lock_irqsave, struct rq, 1721 rq_lock_irqsave(_T->lock, &_T->rf), 1722 rq_unlock_irqrestore(_T->lock, &_T->rf), 1723 struct rq_flags rf) 1724 1725 static inline struct rq * 1726 this_rq_lock_irq(struct rq_flags *rf) 1727 __acquires(rq->lock) 1728 { 1729 struct rq *rq; 1730 1731 local_irq_disable(); 1732 rq = this_rq(); 1733 rq_lock(rq, rf); 1734 return rq; 1735 } 1736 1737 #ifdef CONFIG_NUMA 1738 enum numa_topology_type { 1739 NUMA_DIRECT, 1740 NUMA_GLUELESS_MESH, 1741 NUMA_BACKPLANE, 1742 }; 1743 extern enum numa_topology_type sched_numa_topology_type; 1744 extern int sched_max_numa_distance; 1745 extern bool find_numa_distance(int distance); 1746 extern void sched_init_numa(int offline_node); 1747 extern void sched_update_numa(int cpu, bool online); 1748 extern void sched_domains_numa_masks_set(unsigned int cpu); 1749 extern void sched_domains_numa_masks_clear(unsigned int cpu); 1750 extern int sched_numa_find_closest(const struct cpumask *cpus, int cpu); 1751 #else 1752 static inline void sched_init_numa(int offline_node) { } 1753 static inline void sched_update_numa(int cpu, bool online) { } 1754 static inline void sched_domains_numa_masks_set(unsigned int cpu) { } 1755 static inline void sched_domains_numa_masks_clear(unsigned int cpu) { } 1756 static inline int sched_numa_find_closest(const struct cpumask *cpus, int cpu) 1757 { 1758 return nr_cpu_ids; 1759 } 1760 #endif 1761 1762 #ifdef CONFIG_NUMA_BALANCING 1763 /* The regions in numa_faults array from task_struct */ 1764 enum numa_faults_stats { 1765 NUMA_MEM = 0, 1766 NUMA_CPU, 1767 NUMA_MEMBUF, 1768 NUMA_CPUBUF 1769 }; 1770 extern void sched_setnuma(struct task_struct *p, int node); 1771 extern int migrate_task_to(struct task_struct *p, int cpu); 1772 extern int migrate_swap(struct task_struct *p, struct task_struct *t, 1773 int cpu, int scpu); 1774 extern void init_numa_balancing(unsigned long clone_flags, struct task_struct *p); 1775 #else 1776 static inline void 1777 init_numa_balancing(unsigned long clone_flags, struct task_struct *p) 1778 { 1779 } 1780 #endif /* CONFIG_NUMA_BALANCING */ 1781 1782 #ifdef CONFIG_SMP 1783 1784 static inline void 1785 queue_balance_callback(struct rq *rq, 1786 struct balance_callback *head, 1787 void (*func)(struct rq *rq)) 1788 { 1789 lockdep_assert_rq_held(rq); 1790 1791 /* 1792 * Don't (re)queue an already queued item; nor queue anything when 1793 * balance_push() is active, see the comment with 1794 * balance_push_callback. 1795 */ 1796 if (unlikely(head->next || rq->balance_callback == &balance_push_callback)) 1797 return; 1798 1799 head->func = func; 1800 head->next = rq->balance_callback; 1801 rq->balance_callback = head; 1802 } 1803 1804 #define rcu_dereference_check_sched_domain(p) \ 1805 rcu_dereference_check((p), \ 1806 lockdep_is_held(&sched_domains_mutex)) 1807 1808 /* 1809 * The domain tree (rq->sd) is protected by RCU's quiescent state transition. 1810 * See destroy_sched_domains: call_rcu for details. 1811 * 1812 * The domain tree of any CPU may only be accessed from within 1813 * preempt-disabled sections. 1814 */ 1815 #define for_each_domain(cpu, __sd) \ 1816 for (__sd = rcu_dereference_check_sched_domain(cpu_rq(cpu)->sd); \ 1817 __sd; __sd = __sd->parent) 1818 1819 /* A mask of all the SD flags that have the SDF_SHARED_CHILD metaflag */ 1820 #define SD_FLAG(name, mflags) (name * !!((mflags) & SDF_SHARED_CHILD)) | 1821 static const unsigned int SD_SHARED_CHILD_MASK = 1822 #include <linux/sched/sd_flags.h> 1823 0; 1824 #undef SD_FLAG 1825 1826 /** 1827 * highest_flag_domain - Return highest sched_domain containing flag. 1828 * @cpu: The CPU whose highest level of sched domain is to 1829 * be returned. 1830 * @flag: The flag to check for the highest sched_domain 1831 * for the given CPU. 1832 * 1833 * Returns the highest sched_domain of a CPU which contains @flag. If @flag has 1834 * the SDF_SHARED_CHILD metaflag, all the children domains also have @flag. 1835 */ 1836 static inline struct sched_domain *highest_flag_domain(int cpu, int flag) 1837 { 1838 struct sched_domain *sd, *hsd = NULL; 1839 1840 for_each_domain(cpu, sd) { 1841 if (sd->flags & flag) { 1842 hsd = sd; 1843 continue; 1844 } 1845 1846 /* 1847 * Stop the search if @flag is known to be shared at lower 1848 * levels. It will not be found further up. 1849 */ 1850 if (flag & SD_SHARED_CHILD_MASK) 1851 break; 1852 } 1853 1854 return hsd; 1855 } 1856 1857 static inline struct sched_domain *lowest_flag_domain(int cpu, int flag) 1858 { 1859 struct sched_domain *sd; 1860 1861 for_each_domain(cpu, sd) { 1862 if (sd->flags & flag) 1863 break; 1864 } 1865 1866 return sd; 1867 } 1868 1869 DECLARE_PER_CPU(struct sched_domain __rcu *, sd_llc); 1870 DECLARE_PER_CPU(int, sd_llc_size); 1871 DECLARE_PER_CPU(int, sd_llc_id); 1872 DECLARE_PER_CPU(struct sched_domain_shared __rcu *, sd_llc_shared); 1873 DECLARE_PER_CPU(struct sched_domain __rcu *, sd_numa); 1874 DECLARE_PER_CPU(struct sched_domain __rcu *, sd_asym_packing); 1875 DECLARE_PER_CPU(struct sched_domain __rcu *, sd_asym_cpucapacity); 1876 extern struct static_key_false sched_asym_cpucapacity; 1877 1878 static __always_inline bool sched_asym_cpucap_active(void) 1879 { 1880 return static_branch_unlikely(&sched_asym_cpucapacity); 1881 } 1882 1883 struct sched_group_capacity { 1884 atomic_t ref; 1885 /* 1886 * CPU capacity of this group, SCHED_CAPACITY_SCALE being max capacity 1887 * for a single CPU. 1888 */ 1889 unsigned long capacity; 1890 unsigned long min_capacity; /* Min per-CPU capacity in group */ 1891 unsigned long max_capacity; /* Max per-CPU capacity in group */ 1892 unsigned long next_update; 1893 int imbalance; /* XXX unrelated to capacity but shared group state */ 1894 1895 #ifdef CONFIG_SCHED_DEBUG 1896 int id; 1897 #endif 1898 1899 unsigned long cpumask[]; /* Balance mask */ 1900 }; 1901 1902 struct sched_group { 1903 struct sched_group *next; /* Must be a circular list */ 1904 atomic_t ref; 1905 1906 unsigned int group_weight; 1907 unsigned int cores; 1908 struct sched_group_capacity *sgc; 1909 int asym_prefer_cpu; /* CPU of highest priority in group */ 1910 int flags; 1911 1912 /* 1913 * The CPUs this group covers. 1914 * 1915 * NOTE: this field is variable length. (Allocated dynamically 1916 * by attaching extra space to the end of the structure, 1917 * depending on how many CPUs the kernel has booted up with) 1918 */ 1919 unsigned long cpumask[]; 1920 }; 1921 1922 static inline struct cpumask *sched_group_span(struct sched_group *sg) 1923 { 1924 return to_cpumask(sg->cpumask); 1925 } 1926 1927 /* 1928 * See build_balance_mask(). 1929 */ 1930 static inline struct cpumask *group_balance_mask(struct sched_group *sg) 1931 { 1932 return to_cpumask(sg->sgc->cpumask); 1933 } 1934 1935 extern int group_balance_cpu(struct sched_group *sg); 1936 1937 #ifdef CONFIG_SCHED_DEBUG 1938 void update_sched_domain_debugfs(void); 1939 void dirty_sched_domain_sysctl(int cpu); 1940 #else 1941 static inline void update_sched_domain_debugfs(void) 1942 { 1943 } 1944 static inline void dirty_sched_domain_sysctl(int cpu) 1945 { 1946 } 1947 #endif 1948 1949 extern int sched_update_scaling(void); 1950 1951 static inline const struct cpumask *task_user_cpus(struct task_struct *p) 1952 { 1953 if (!p->user_cpus_ptr) 1954 return cpu_possible_mask; /* &init_task.cpus_mask */ 1955 return p->user_cpus_ptr; 1956 } 1957 #endif /* CONFIG_SMP */ 1958 1959 #include "stats.h" 1960 1961 #if defined(CONFIG_SCHED_CORE) && defined(CONFIG_SCHEDSTATS) 1962 1963 extern void __sched_core_account_forceidle(struct rq *rq); 1964 1965 static inline void sched_core_account_forceidle(struct rq *rq) 1966 { 1967 if (schedstat_enabled()) 1968 __sched_core_account_forceidle(rq); 1969 } 1970 1971 extern void __sched_core_tick(struct rq *rq); 1972 1973 static inline void sched_core_tick(struct rq *rq) 1974 { 1975 if (sched_core_enabled(rq) && schedstat_enabled()) 1976 __sched_core_tick(rq); 1977 } 1978 1979 #else 1980 1981 static inline void sched_core_account_forceidle(struct rq *rq) {} 1982 1983 static inline void sched_core_tick(struct rq *rq) {} 1984 1985 #endif /* CONFIG_SCHED_CORE && CONFIG_SCHEDSTATS */ 1986 1987 #ifdef CONFIG_CGROUP_SCHED 1988 1989 /* 1990 * Return the group to which this tasks belongs. 1991 * 1992 * We cannot use task_css() and friends because the cgroup subsystem 1993 * changes that value before the cgroup_subsys::attach() method is called, 1994 * therefore we cannot pin it and might observe the wrong value. 1995 * 1996 * The same is true for autogroup's p->signal->autogroup->tg, the autogroup 1997 * core changes this before calling sched_move_task(). 1998 * 1999 * Instead we use a 'copy' which is updated from sched_move_task() while 2000 * holding both task_struct::pi_lock and rq::lock. 2001 */ 2002 static inline struct task_group *task_group(struct task_struct *p) 2003 { 2004 return p->sched_task_group; 2005 } 2006 2007 /* Change a task's cfs_rq and parent entity if it moves across CPUs/groups */ 2008 static inline void set_task_rq(struct task_struct *p, unsigned int cpu) 2009 { 2010 #if defined(CONFIG_FAIR_GROUP_SCHED) || defined(CONFIG_RT_GROUP_SCHED) 2011 struct task_group *tg = task_group(p); 2012 #endif 2013 2014 #ifdef CONFIG_FAIR_GROUP_SCHED 2015 set_task_rq_fair(&p->se, p->se.cfs_rq, tg->cfs_rq[cpu]); 2016 p->se.cfs_rq = tg->cfs_rq[cpu]; 2017 p->se.parent = tg->se[cpu]; 2018 p->se.depth = tg->se[cpu] ? tg->se[cpu]->depth + 1 : 0; 2019 #endif 2020 2021 #ifdef CONFIG_RT_GROUP_SCHED 2022 p->rt.rt_rq = tg->rt_rq[cpu]; 2023 p->rt.parent = tg->rt_se[cpu]; 2024 #endif 2025 } 2026 2027 #else /* CONFIG_CGROUP_SCHED */ 2028 2029 static inline void set_task_rq(struct task_struct *p, unsigned int cpu) { } 2030 static inline struct task_group *task_group(struct task_struct *p) 2031 { 2032 return NULL; 2033 } 2034 2035 #endif /* CONFIG_CGROUP_SCHED */ 2036 2037 static inline void __set_task_cpu(struct task_struct *p, unsigned int cpu) 2038 { 2039 set_task_rq(p, cpu); 2040 #ifdef CONFIG_SMP 2041 /* 2042 * After ->cpu is set up to a new value, task_rq_lock(p, ...) can be 2043 * successfully executed on another CPU. We must ensure that updates of 2044 * per-task data have been completed by this moment. 2045 */ 2046 smp_wmb(); 2047 WRITE_ONCE(task_thread_info(p)->cpu, cpu); 2048 p->wake_cpu = cpu; 2049 #endif 2050 } 2051 2052 /* 2053 * Tunables that become constants when CONFIG_SCHED_DEBUG is off: 2054 */ 2055 #ifdef CONFIG_SCHED_DEBUG 2056 # define const_debug __read_mostly 2057 #else 2058 # define const_debug const 2059 #endif 2060 2061 #define SCHED_FEAT(name, enabled) \ 2062 __SCHED_FEAT_##name , 2063 2064 enum { 2065 #include "features.h" 2066 __SCHED_FEAT_NR, 2067 }; 2068 2069 #undef SCHED_FEAT 2070 2071 #ifdef CONFIG_SCHED_DEBUG 2072 2073 /* 2074 * To support run-time toggling of sched features, all the translation units 2075 * (but core.c) reference the sysctl_sched_features defined in core.c. 2076 */ 2077 extern const_debug unsigned int sysctl_sched_features; 2078 2079 #ifdef CONFIG_JUMP_LABEL 2080 #define SCHED_FEAT(name, enabled) \ 2081 static __always_inline bool static_branch_##name(struct static_key *key) \ 2082 { \ 2083 return static_key_##enabled(key); \ 2084 } 2085 2086 #include "features.h" 2087 #undef SCHED_FEAT 2088 2089 extern struct static_key sched_feat_keys[__SCHED_FEAT_NR]; 2090 #define sched_feat(x) (static_branch_##x(&sched_feat_keys[__SCHED_FEAT_##x])) 2091 2092 #else /* !CONFIG_JUMP_LABEL */ 2093 2094 #define sched_feat(x) (sysctl_sched_features & (1UL << __SCHED_FEAT_##x)) 2095 2096 #endif /* CONFIG_JUMP_LABEL */ 2097 2098 #else /* !SCHED_DEBUG */ 2099 2100 /* 2101 * Each translation unit has its own copy of sysctl_sched_features to allow 2102 * constants propagation at compile time and compiler optimization based on 2103 * features default. 2104 */ 2105 #define SCHED_FEAT(name, enabled) \ 2106 (1UL << __SCHED_FEAT_##name) * enabled | 2107 static const_debug __maybe_unused unsigned int sysctl_sched_features = 2108 #include "features.h" 2109 0; 2110 #undef SCHED_FEAT 2111 2112 #define sched_feat(x) !!(sysctl_sched_features & (1UL << __SCHED_FEAT_##x)) 2113 2114 #endif /* SCHED_DEBUG */ 2115 2116 extern struct static_key_false sched_numa_balancing; 2117 extern struct static_key_false sched_schedstats; 2118 2119 static inline u64 global_rt_period(void) 2120 { 2121 return (u64)sysctl_sched_rt_period * NSEC_PER_USEC; 2122 } 2123 2124 static inline u64 global_rt_runtime(void) 2125 { 2126 if (sysctl_sched_rt_runtime < 0) 2127 return RUNTIME_INF; 2128 2129 return (u64)sysctl_sched_rt_runtime * NSEC_PER_USEC; 2130 } 2131 2132 static inline int task_current(struct rq *rq, struct task_struct *p) 2133 { 2134 return rq->curr == p; 2135 } 2136 2137 static inline int task_on_cpu(struct rq *rq, struct task_struct *p) 2138 { 2139 #ifdef CONFIG_SMP 2140 return p->on_cpu; 2141 #else 2142 return task_current(rq, p); 2143 #endif 2144 } 2145 2146 static inline int task_on_rq_queued(struct task_struct *p) 2147 { 2148 return p->on_rq == TASK_ON_RQ_QUEUED; 2149 } 2150 2151 static inline int task_on_rq_migrating(struct task_struct *p) 2152 { 2153 return READ_ONCE(p->on_rq) == TASK_ON_RQ_MIGRATING; 2154 } 2155 2156 /* Wake flags. The first three directly map to some SD flag value */ 2157 #define WF_EXEC 0x02 /* Wakeup after exec; maps to SD_BALANCE_EXEC */ 2158 #define WF_FORK 0x04 /* Wakeup after fork; maps to SD_BALANCE_FORK */ 2159 #define WF_TTWU 0x08 /* Wakeup; maps to SD_BALANCE_WAKE */ 2160 2161 #define WF_SYNC 0x10 /* Waker goes to sleep after wakeup */ 2162 #define WF_MIGRATED 0x20 /* Internal use, task got migrated */ 2163 #define WF_CURRENT_CPU 0x40 /* Prefer to move the wakee to the current CPU. */ 2164 2165 #ifdef CONFIG_SMP 2166 static_assert(WF_EXEC == SD_BALANCE_EXEC); 2167 static_assert(WF_FORK == SD_BALANCE_FORK); 2168 static_assert(WF_TTWU == SD_BALANCE_WAKE); 2169 #endif 2170 2171 /* 2172 * To aid in avoiding the subversion of "niceness" due to uneven distribution 2173 * of tasks with abnormal "nice" values across CPUs the contribution that 2174 * each task makes to its run queue's load is weighted according to its 2175 * scheduling class and "nice" value. For SCHED_NORMAL tasks this is just a 2176 * scaled version of the new time slice allocation that they receive on time 2177 * slice expiry etc. 2178 */ 2179 2180 #define WEIGHT_IDLEPRIO 3 2181 #define WMULT_IDLEPRIO 1431655765 2182 2183 extern const int sched_prio_to_weight[40]; 2184 extern const u32 sched_prio_to_wmult[40]; 2185 2186 /* 2187 * {de,en}queue flags: 2188 * 2189 * DEQUEUE_SLEEP - task is no longer runnable 2190 * ENQUEUE_WAKEUP - task just became runnable 2191 * 2192 * SAVE/RESTORE - an otherwise spurious dequeue/enqueue, done to ensure tasks 2193 * are in a known state which allows modification. Such pairs 2194 * should preserve as much state as possible. 2195 * 2196 * MOVE - paired with SAVE/RESTORE, explicitly does not preserve the location 2197 * in the runqueue. 2198 * 2199 * NOCLOCK - skip the update_rq_clock() (avoids double updates) 2200 * 2201 * MIGRATION - p->on_rq == TASK_ON_RQ_MIGRATING (used for DEADLINE) 2202 * 2203 * ENQUEUE_HEAD - place at front of runqueue (tail if not specified) 2204 * ENQUEUE_REPLENISH - CBS (replenish runtime and postpone deadline) 2205 * ENQUEUE_MIGRATED - the task was migrated during wakeup 2206 * 2207 */ 2208 2209 #define DEQUEUE_SLEEP 0x01 2210 #define DEQUEUE_SAVE 0x02 /* Matches ENQUEUE_RESTORE */ 2211 #define DEQUEUE_MOVE 0x04 /* Matches ENQUEUE_MOVE */ 2212 #define DEQUEUE_NOCLOCK 0x08 /* Matches ENQUEUE_NOCLOCK */ 2213 #define DEQUEUE_MIGRATING 0x100 /* Matches ENQUEUE_MIGRATING */ 2214 2215 #define ENQUEUE_WAKEUP 0x01 2216 #define ENQUEUE_RESTORE 0x02 2217 #define ENQUEUE_MOVE 0x04 2218 #define ENQUEUE_NOCLOCK 0x08 2219 2220 #define ENQUEUE_HEAD 0x10 2221 #define ENQUEUE_REPLENISH 0x20 2222 #ifdef CONFIG_SMP 2223 #define ENQUEUE_MIGRATED 0x40 2224 #else 2225 #define ENQUEUE_MIGRATED 0x00 2226 #endif 2227 #define ENQUEUE_INITIAL 0x80 2228 #define ENQUEUE_MIGRATING 0x100 2229 2230 #define RETRY_TASK ((void *)-1UL) 2231 2232 struct affinity_context { 2233 const struct cpumask *new_mask; 2234 struct cpumask *user_mask; 2235 unsigned int flags; 2236 }; 2237 2238 extern s64 update_curr_common(struct rq *rq); 2239 2240 struct sched_class { 2241 2242 #ifdef CONFIG_UCLAMP_TASK 2243 int uclamp_enabled; 2244 #endif 2245 2246 void (*enqueue_task) (struct rq *rq, struct task_struct *p, int flags); 2247 void (*dequeue_task) (struct rq *rq, struct task_struct *p, int flags); 2248 void (*yield_task) (struct rq *rq); 2249 bool (*yield_to_task)(struct rq *rq, struct task_struct *p); 2250 2251 void (*wakeup_preempt)(struct rq *rq, struct task_struct *p, int flags); 2252 2253 struct task_struct *(*pick_next_task)(struct rq *rq); 2254 2255 void (*put_prev_task)(struct rq *rq, struct task_struct *p); 2256 void (*set_next_task)(struct rq *rq, struct task_struct *p, bool first); 2257 2258 #ifdef CONFIG_SMP 2259 int (*balance)(struct rq *rq, struct task_struct *prev, struct rq_flags *rf); 2260 int (*select_task_rq)(struct task_struct *p, int task_cpu, int flags); 2261 2262 struct task_struct * (*pick_task)(struct rq *rq); 2263 2264 void (*migrate_task_rq)(struct task_struct *p, int new_cpu); 2265 2266 void (*task_woken)(struct rq *this_rq, struct task_struct *task); 2267 2268 void (*set_cpus_allowed)(struct task_struct *p, struct affinity_context *ctx); 2269 2270 void (*rq_online)(struct rq *rq); 2271 void (*rq_offline)(struct rq *rq); 2272 2273 struct rq *(*find_lock_rq)(struct task_struct *p, struct rq *rq); 2274 #endif 2275 2276 void (*task_tick)(struct rq *rq, struct task_struct *p, int queued); 2277 void (*task_fork)(struct task_struct *p); 2278 void (*task_dead)(struct task_struct *p); 2279 2280 /* 2281 * The switched_from() call is allowed to drop rq->lock, therefore we 2282 * cannot assume the switched_from/switched_to pair is serialized by 2283 * rq->lock. They are however serialized by p->pi_lock. 2284 */ 2285 void (*switched_from)(struct rq *this_rq, struct task_struct *task); 2286 void (*switched_to) (struct rq *this_rq, struct task_struct *task); 2287 void (*prio_changed) (struct rq *this_rq, struct task_struct *task, 2288 int oldprio); 2289 2290 unsigned int (*get_rr_interval)(struct rq *rq, 2291 struct task_struct *task); 2292 2293 void (*update_curr)(struct rq *rq); 2294 2295 #ifdef CONFIG_FAIR_GROUP_SCHED 2296 void (*task_change_group)(struct task_struct *p); 2297 #endif 2298 2299 #ifdef CONFIG_SCHED_CORE 2300 int (*task_is_throttled)(struct task_struct *p, int cpu); 2301 #endif 2302 }; 2303 2304 static inline void put_prev_task(struct rq *rq, struct task_struct *prev) 2305 { 2306 WARN_ON_ONCE(rq->curr != prev); 2307 prev->sched_class->put_prev_task(rq, prev); 2308 } 2309 2310 static inline void set_next_task(struct rq *rq, struct task_struct *next) 2311 { 2312 next->sched_class->set_next_task(rq, next, false); 2313 } 2314 2315 2316 /* 2317 * Helper to define a sched_class instance; each one is placed in a separate 2318 * section which is ordered by the linker script: 2319 * 2320 * include/asm-generic/vmlinux.lds.h 2321 * 2322 * *CAREFUL* they are laid out in *REVERSE* order!!! 2323 * 2324 * Also enforce alignment on the instance, not the type, to guarantee layout. 2325 */ 2326 #define DEFINE_SCHED_CLASS(name) \ 2327 const struct sched_class name##_sched_class \ 2328 __aligned(__alignof__(struct sched_class)) \ 2329 __section("__" #name "_sched_class") 2330 2331 /* Defined in include/asm-generic/vmlinux.lds.h */ 2332 extern struct sched_class __sched_class_highest[]; 2333 extern struct sched_class __sched_class_lowest[]; 2334 2335 #define for_class_range(class, _from, _to) \ 2336 for (class = (_from); class < (_to); class++) 2337 2338 #define for_each_class(class) \ 2339 for_class_range(class, __sched_class_highest, __sched_class_lowest) 2340 2341 #define sched_class_above(_a, _b) ((_a) < (_b)) 2342 2343 extern const struct sched_class stop_sched_class; 2344 extern const struct sched_class dl_sched_class; 2345 extern const struct sched_class rt_sched_class; 2346 extern const struct sched_class fair_sched_class; 2347 extern const struct sched_class idle_sched_class; 2348 2349 static inline bool sched_stop_runnable(struct rq *rq) 2350 { 2351 return rq->stop && task_on_rq_queued(rq->stop); 2352 } 2353 2354 static inline bool sched_dl_runnable(struct rq *rq) 2355 { 2356 return rq->dl.dl_nr_running > 0; 2357 } 2358 2359 static inline bool sched_rt_runnable(struct rq *rq) 2360 { 2361 return rq->rt.rt_queued > 0; 2362 } 2363 2364 static inline bool sched_fair_runnable(struct rq *rq) 2365 { 2366 return rq->cfs.nr_running > 0; 2367 } 2368 2369 extern struct task_struct *pick_next_task_fair(struct rq *rq, struct task_struct *prev, struct rq_flags *rf); 2370 extern struct task_struct *pick_next_task_idle(struct rq *rq); 2371 2372 #define SCA_CHECK 0x01 2373 #define SCA_MIGRATE_DISABLE 0x02 2374 #define SCA_MIGRATE_ENABLE 0x04 2375 #define SCA_USER 0x08 2376 2377 #ifdef CONFIG_SMP 2378 2379 extern void update_group_capacity(struct sched_domain *sd, int cpu); 2380 2381 extern void trigger_load_balance(struct rq *rq); 2382 2383 extern void set_cpus_allowed_common(struct task_struct *p, struct affinity_context *ctx); 2384 2385 static inline struct task_struct *get_push_task(struct rq *rq) 2386 { 2387 struct task_struct *p = rq->curr; 2388 2389 lockdep_assert_rq_held(rq); 2390 2391 if (rq->push_busy) 2392 return NULL; 2393 2394 if (p->nr_cpus_allowed == 1) 2395 return NULL; 2396 2397 if (p->migration_disabled) 2398 return NULL; 2399 2400 rq->push_busy = true; 2401 return get_task_struct(p); 2402 } 2403 2404 extern int push_cpu_stop(void *arg); 2405 2406 #endif 2407 2408 #ifdef CONFIG_CPU_IDLE 2409 static inline void idle_set_state(struct rq *rq, 2410 struct cpuidle_state *idle_state) 2411 { 2412 rq->idle_state = idle_state; 2413 } 2414 2415 static inline struct cpuidle_state *idle_get_state(struct rq *rq) 2416 { 2417 SCHED_WARN_ON(!rcu_read_lock_held()); 2418 2419 return rq->idle_state; 2420 } 2421 #else 2422 static inline void idle_set_state(struct rq *rq, 2423 struct cpuidle_state *idle_state) 2424 { 2425 } 2426 2427 static inline struct cpuidle_state *idle_get_state(struct rq *rq) 2428 { 2429 return NULL; 2430 } 2431 #endif 2432 2433 extern void schedule_idle(void); 2434 asmlinkage void schedule_user(void); 2435 2436 extern void sysrq_sched_debug_show(void); 2437 extern void sched_init_granularity(void); 2438 extern void update_max_interval(void); 2439 2440 extern void init_sched_dl_class(void); 2441 extern void init_sched_rt_class(void); 2442 extern void init_sched_fair_class(void); 2443 2444 extern void reweight_task(struct task_struct *p, const struct load_weight *lw); 2445 2446 extern void resched_curr(struct rq *rq); 2447 extern void resched_cpu(int cpu); 2448 2449 extern struct rt_bandwidth def_rt_bandwidth; 2450 extern void init_rt_bandwidth(struct rt_bandwidth *rt_b, u64 period, u64 runtime); 2451 extern bool sched_rt_bandwidth_account(struct rt_rq *rt_rq); 2452 2453 extern void init_dl_entity(struct sched_dl_entity *dl_se); 2454 2455 #define BW_SHIFT 20 2456 #define BW_UNIT (1 << BW_SHIFT) 2457 #define RATIO_SHIFT 8 2458 #define MAX_BW_BITS (64 - BW_SHIFT) 2459 #define MAX_BW ((1ULL << MAX_BW_BITS) - 1) 2460 unsigned long to_ratio(u64 period, u64 runtime); 2461 2462 extern void init_entity_runnable_average(struct sched_entity *se); 2463 extern void post_init_entity_util_avg(struct task_struct *p); 2464 2465 #ifdef CONFIG_NO_HZ_FULL 2466 extern bool sched_can_stop_tick(struct rq *rq); 2467 extern int __init sched_tick_offload_init(void); 2468 2469 /* 2470 * Tick may be needed by tasks in the runqueue depending on their policy and 2471 * requirements. If tick is needed, lets send the target an IPI to kick it out of 2472 * nohz mode if necessary. 2473 */ 2474 static inline void sched_update_tick_dependency(struct rq *rq) 2475 { 2476 int cpu = cpu_of(rq); 2477 2478 if (!tick_nohz_full_cpu(cpu)) 2479 return; 2480 2481 if (sched_can_stop_tick(rq)) 2482 tick_nohz_dep_clear_cpu(cpu, TICK_DEP_BIT_SCHED); 2483 else 2484 tick_nohz_dep_set_cpu(cpu, TICK_DEP_BIT_SCHED); 2485 } 2486 #else 2487 static inline int sched_tick_offload_init(void) { return 0; } 2488 static inline void sched_update_tick_dependency(struct rq *rq) { } 2489 #endif 2490 2491 static inline void add_nr_running(struct rq *rq, unsigned count) 2492 { 2493 unsigned prev_nr = rq->nr_running; 2494 2495 rq->nr_running = prev_nr + count; 2496 if (trace_sched_update_nr_running_tp_enabled()) { 2497 call_trace_sched_update_nr_running(rq, count); 2498 } 2499 2500 #ifdef CONFIG_SMP 2501 if (prev_nr < 2 && rq->nr_running >= 2) { 2502 if (!READ_ONCE(rq->rd->overload)) 2503 WRITE_ONCE(rq->rd->overload, 1); 2504 } 2505 #endif 2506 2507 sched_update_tick_dependency(rq); 2508 } 2509 2510 static inline void sub_nr_running(struct rq *rq, unsigned count) 2511 { 2512 rq->nr_running -= count; 2513 if (trace_sched_update_nr_running_tp_enabled()) { 2514 call_trace_sched_update_nr_running(rq, -count); 2515 } 2516 2517 /* Check if we still need preemption */ 2518 sched_update_tick_dependency(rq); 2519 } 2520 2521 extern void activate_task(struct rq *rq, struct task_struct *p, int flags); 2522 extern void deactivate_task(struct rq *rq, struct task_struct *p, int flags); 2523 2524 extern void wakeup_preempt(struct rq *rq, struct task_struct *p, int flags); 2525 2526 #ifdef CONFIG_PREEMPT_RT 2527 #define SCHED_NR_MIGRATE_BREAK 8 2528 #else 2529 #define SCHED_NR_MIGRATE_BREAK 32 2530 #endif 2531 2532 extern const_debug unsigned int sysctl_sched_nr_migrate; 2533 extern const_debug unsigned int sysctl_sched_migration_cost; 2534 2535 extern unsigned int sysctl_sched_base_slice; 2536 2537 #ifdef CONFIG_SCHED_DEBUG 2538 extern int sysctl_resched_latency_warn_ms; 2539 extern int sysctl_resched_latency_warn_once; 2540 2541 extern unsigned int sysctl_sched_tunable_scaling; 2542 2543 extern unsigned int sysctl_numa_balancing_scan_delay; 2544 extern unsigned int sysctl_numa_balancing_scan_period_min; 2545 extern unsigned int sysctl_numa_balancing_scan_period_max; 2546 extern unsigned int sysctl_numa_balancing_scan_size; 2547 extern unsigned int sysctl_numa_balancing_hot_threshold; 2548 #endif 2549 2550 #ifdef CONFIG_SCHED_HRTICK 2551 2552 /* 2553 * Use hrtick when: 2554 * - enabled by features 2555 * - hrtimer is actually high res 2556 */ 2557 static inline int hrtick_enabled(struct rq *rq) 2558 { 2559 if (!cpu_active(cpu_of(rq))) 2560 return 0; 2561 return hrtimer_is_hres_active(&rq->hrtick_timer); 2562 } 2563 2564 static inline int hrtick_enabled_fair(struct rq *rq) 2565 { 2566 if (!sched_feat(HRTICK)) 2567 return 0; 2568 return hrtick_enabled(rq); 2569 } 2570 2571 static inline int hrtick_enabled_dl(struct rq *rq) 2572 { 2573 if (!sched_feat(HRTICK_DL)) 2574 return 0; 2575 return hrtick_enabled(rq); 2576 } 2577 2578 void hrtick_start(struct rq *rq, u64 delay); 2579 2580 #else 2581 2582 static inline int hrtick_enabled_fair(struct rq *rq) 2583 { 2584 return 0; 2585 } 2586 2587 static inline int hrtick_enabled_dl(struct rq *rq) 2588 { 2589 return 0; 2590 } 2591 2592 static inline int hrtick_enabled(struct rq *rq) 2593 { 2594 return 0; 2595 } 2596 2597 #endif /* CONFIG_SCHED_HRTICK */ 2598 2599 #ifndef arch_scale_freq_tick 2600 static __always_inline 2601 void arch_scale_freq_tick(void) 2602 { 2603 } 2604 #endif 2605 2606 #ifndef arch_scale_freq_capacity 2607 /** 2608 * arch_scale_freq_capacity - get the frequency scale factor of a given CPU. 2609 * @cpu: the CPU in question. 2610 * 2611 * Return: the frequency scale factor normalized against SCHED_CAPACITY_SCALE, i.e. 2612 * 2613 * f_curr 2614 * ------ * SCHED_CAPACITY_SCALE 2615 * f_max 2616 */ 2617 static __always_inline 2618 unsigned long arch_scale_freq_capacity(int cpu) 2619 { 2620 return SCHED_CAPACITY_SCALE; 2621 } 2622 #endif 2623 2624 #ifdef CONFIG_SCHED_DEBUG 2625 /* 2626 * In double_lock_balance()/double_rq_lock(), we use raw_spin_rq_lock() to 2627 * acquire rq lock instead of rq_lock(). So at the end of these two functions 2628 * we need to call double_rq_clock_clear_update() to clear RQCF_UPDATED of 2629 * rq->clock_update_flags to avoid the WARN_DOUBLE_CLOCK warning. 2630 */ 2631 static inline void double_rq_clock_clear_update(struct rq *rq1, struct rq *rq2) 2632 { 2633 rq1->clock_update_flags &= (RQCF_REQ_SKIP|RQCF_ACT_SKIP); 2634 /* rq1 == rq2 for !CONFIG_SMP, so just clear RQCF_UPDATED once. */ 2635 #ifdef CONFIG_SMP 2636 rq2->clock_update_flags &= (RQCF_REQ_SKIP|RQCF_ACT_SKIP); 2637 #endif 2638 } 2639 #else 2640 static inline void double_rq_clock_clear_update(struct rq *rq1, struct rq *rq2) {} 2641 #endif 2642 2643 #define DEFINE_LOCK_GUARD_2(name, type, _lock, _unlock, ...) \ 2644 __DEFINE_UNLOCK_GUARD(name, type, _unlock, type *lock2; __VA_ARGS__) \ 2645 static inline class_##name##_t class_##name##_constructor(type *lock, type *lock2) \ 2646 { class_##name##_t _t = { .lock = lock, .lock2 = lock2 }, *_T = &_t; \ 2647 _lock; return _t; } 2648 2649 #ifdef CONFIG_SMP 2650 2651 static inline bool rq_order_less(struct rq *rq1, struct rq *rq2) 2652 { 2653 #ifdef CONFIG_SCHED_CORE 2654 /* 2655 * In order to not have {0,2},{1,3} turn into into an AB-BA, 2656 * order by core-id first and cpu-id second. 2657 * 2658 * Notably: 2659 * 2660 * double_rq_lock(0,3); will take core-0, core-1 lock 2661 * double_rq_lock(1,2); will take core-1, core-0 lock 2662 * 2663 * when only cpu-id is considered. 2664 */ 2665 if (rq1->core->cpu < rq2->core->cpu) 2666 return true; 2667 if (rq1->core->cpu > rq2->core->cpu) 2668 return false; 2669 2670 /* 2671 * __sched_core_flip() relies on SMT having cpu-id lock order. 2672 */ 2673 #endif 2674 return rq1->cpu < rq2->cpu; 2675 } 2676 2677 extern void double_rq_lock(struct rq *rq1, struct rq *rq2); 2678 2679 #ifdef CONFIG_PREEMPTION 2680 2681 /* 2682 * fair double_lock_balance: Safely acquires both rq->locks in a fair 2683 * way at the expense of forcing extra atomic operations in all 2684 * invocations. This assures that the double_lock is acquired using the 2685 * same underlying policy as the spinlock_t on this architecture, which 2686 * reduces latency compared to the unfair variant below. However, it 2687 * also adds more overhead and therefore may reduce throughput. 2688 */ 2689 static inline int _double_lock_balance(struct rq *this_rq, struct rq *busiest) 2690 __releases(this_rq->lock) 2691 __acquires(busiest->lock) 2692 __acquires(this_rq->lock) 2693 { 2694 raw_spin_rq_unlock(this_rq); 2695 double_rq_lock(this_rq, busiest); 2696 2697 return 1; 2698 } 2699 2700 #else 2701 /* 2702 * Unfair double_lock_balance: Optimizes throughput at the expense of 2703 * latency by eliminating extra atomic operations when the locks are 2704 * already in proper order on entry. This favors lower CPU-ids and will 2705 * grant the double lock to lower CPUs over higher ids under contention, 2706 * regardless of entry order into the function. 2707 */ 2708 static inline int _double_lock_balance(struct rq *this_rq, struct rq *busiest) 2709 __releases(this_rq->lock) 2710 __acquires(busiest->lock) 2711 __acquires(this_rq->lock) 2712 { 2713 if (__rq_lockp(this_rq) == __rq_lockp(busiest) || 2714 likely(raw_spin_rq_trylock(busiest))) { 2715 double_rq_clock_clear_update(this_rq, busiest); 2716 return 0; 2717 } 2718 2719 if (rq_order_less(this_rq, busiest)) { 2720 raw_spin_rq_lock_nested(busiest, SINGLE_DEPTH_NESTING); 2721 double_rq_clock_clear_update(this_rq, busiest); 2722 return 0; 2723 } 2724 2725 raw_spin_rq_unlock(this_rq); 2726 double_rq_lock(this_rq, busiest); 2727 2728 return 1; 2729 } 2730 2731 #endif /* CONFIG_PREEMPTION */ 2732 2733 /* 2734 * double_lock_balance - lock the busiest runqueue, this_rq is locked already. 2735 */ 2736 static inline int double_lock_balance(struct rq *this_rq, struct rq *busiest) 2737 { 2738 lockdep_assert_irqs_disabled(); 2739 2740 return _double_lock_balance(this_rq, busiest); 2741 } 2742 2743 static inline void double_unlock_balance(struct rq *this_rq, struct rq *busiest) 2744 __releases(busiest->lock) 2745 { 2746 if (__rq_lockp(this_rq) != __rq_lockp(busiest)) 2747 raw_spin_rq_unlock(busiest); 2748 lock_set_subclass(&__rq_lockp(this_rq)->dep_map, 0, _RET_IP_); 2749 } 2750 2751 static inline void double_lock(spinlock_t *l1, spinlock_t *l2) 2752 { 2753 if (l1 > l2) 2754 swap(l1, l2); 2755 2756 spin_lock(l1); 2757 spin_lock_nested(l2, SINGLE_DEPTH_NESTING); 2758 } 2759 2760 static inline void double_lock_irq(spinlock_t *l1, spinlock_t *l2) 2761 { 2762 if (l1 > l2) 2763 swap(l1, l2); 2764 2765 spin_lock_irq(l1); 2766 spin_lock_nested(l2, SINGLE_DEPTH_NESTING); 2767 } 2768 2769 static inline void double_raw_lock(raw_spinlock_t *l1, raw_spinlock_t *l2) 2770 { 2771 if (l1 > l2) 2772 swap(l1, l2); 2773 2774 raw_spin_lock(l1); 2775 raw_spin_lock_nested(l2, SINGLE_DEPTH_NESTING); 2776 } 2777 2778 static inline void double_raw_unlock(raw_spinlock_t *l1, raw_spinlock_t *l2) 2779 { 2780 raw_spin_unlock(l1); 2781 raw_spin_unlock(l2); 2782 } 2783 2784 DEFINE_LOCK_GUARD_2(double_raw_spinlock, raw_spinlock_t, 2785 double_raw_lock(_T->lock, _T->lock2), 2786 double_raw_unlock(_T->lock, _T->lock2)) 2787 2788 /* 2789 * double_rq_unlock - safely unlock two runqueues 2790 * 2791 * Note this does not restore interrupts like task_rq_unlock, 2792 * you need to do so manually after calling. 2793 */ 2794 static inline void double_rq_unlock(struct rq *rq1, struct rq *rq2) 2795 __releases(rq1->lock) 2796 __releases(rq2->lock) 2797 { 2798 if (__rq_lockp(rq1) != __rq_lockp(rq2)) 2799 raw_spin_rq_unlock(rq2); 2800 else 2801 __release(rq2->lock); 2802 raw_spin_rq_unlock(rq1); 2803 } 2804 2805 extern void set_rq_online (struct rq *rq); 2806 extern void set_rq_offline(struct rq *rq); 2807 extern bool sched_smp_initialized; 2808 2809 #else /* CONFIG_SMP */ 2810 2811 /* 2812 * double_rq_lock - safely lock two runqueues 2813 * 2814 * Note this does not disable interrupts like task_rq_lock, 2815 * you need to do so manually before calling. 2816 */ 2817 static inline void double_rq_lock(struct rq *rq1, struct rq *rq2) 2818 __acquires(rq1->lock) 2819 __acquires(rq2->lock) 2820 { 2821 WARN_ON_ONCE(!irqs_disabled()); 2822 WARN_ON_ONCE(rq1 != rq2); 2823 raw_spin_rq_lock(rq1); 2824 __acquire(rq2->lock); /* Fake it out ;) */ 2825 double_rq_clock_clear_update(rq1, rq2); 2826 } 2827 2828 /* 2829 * double_rq_unlock - safely unlock two runqueues 2830 * 2831 * Note this does not restore interrupts like task_rq_unlock, 2832 * you need to do so manually after calling. 2833 */ 2834 static inline void double_rq_unlock(struct rq *rq1, struct rq *rq2) 2835 __releases(rq1->lock) 2836 __releases(rq2->lock) 2837 { 2838 WARN_ON_ONCE(rq1 != rq2); 2839 raw_spin_rq_unlock(rq1); 2840 __release(rq2->lock); 2841 } 2842 2843 #endif 2844 2845 DEFINE_LOCK_GUARD_2(double_rq_lock, struct rq, 2846 double_rq_lock(_T->lock, _T->lock2), 2847 double_rq_unlock(_T->lock, _T->lock2)) 2848 2849 extern struct sched_entity *__pick_first_entity(struct cfs_rq *cfs_rq); 2850 extern struct sched_entity *__pick_last_entity(struct cfs_rq *cfs_rq); 2851 2852 #ifdef CONFIG_SCHED_DEBUG 2853 extern bool sched_debug_verbose; 2854 2855 extern void print_cfs_stats(struct seq_file *m, int cpu); 2856 extern void print_rt_stats(struct seq_file *m, int cpu); 2857 extern void print_dl_stats(struct seq_file *m, int cpu); 2858 extern void print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq); 2859 extern void print_rt_rq(struct seq_file *m, int cpu, struct rt_rq *rt_rq); 2860 extern void print_dl_rq(struct seq_file *m, int cpu, struct dl_rq *dl_rq); 2861 2862 extern void resched_latency_warn(int cpu, u64 latency); 2863 #ifdef CONFIG_NUMA_BALANCING 2864 extern void 2865 show_numa_stats(struct task_struct *p, struct seq_file *m); 2866 extern void 2867 print_numa_stats(struct seq_file *m, int node, unsigned long tsf, 2868 unsigned long tpf, unsigned long gsf, unsigned long gpf); 2869 #endif /* CONFIG_NUMA_BALANCING */ 2870 #else 2871 static inline void resched_latency_warn(int cpu, u64 latency) {} 2872 #endif /* CONFIG_SCHED_DEBUG */ 2873 2874 extern void init_cfs_rq(struct cfs_rq *cfs_rq); 2875 extern void init_rt_rq(struct rt_rq *rt_rq); 2876 extern void init_dl_rq(struct dl_rq *dl_rq); 2877 2878 extern void cfs_bandwidth_usage_inc(void); 2879 extern void cfs_bandwidth_usage_dec(void); 2880 2881 #ifdef CONFIG_NO_HZ_COMMON 2882 #define NOHZ_BALANCE_KICK_BIT 0 2883 #define NOHZ_STATS_KICK_BIT 1 2884 #define NOHZ_NEWILB_KICK_BIT 2 2885 #define NOHZ_NEXT_KICK_BIT 3 2886 2887 /* Run rebalance_domains() */ 2888 #define NOHZ_BALANCE_KICK BIT(NOHZ_BALANCE_KICK_BIT) 2889 /* Update blocked load */ 2890 #define NOHZ_STATS_KICK BIT(NOHZ_STATS_KICK_BIT) 2891 /* Update blocked load when entering idle */ 2892 #define NOHZ_NEWILB_KICK BIT(NOHZ_NEWILB_KICK_BIT) 2893 /* Update nohz.next_balance */ 2894 #define NOHZ_NEXT_KICK BIT(NOHZ_NEXT_KICK_BIT) 2895 2896 #define NOHZ_KICK_MASK (NOHZ_BALANCE_KICK | NOHZ_STATS_KICK | NOHZ_NEXT_KICK) 2897 2898 #define nohz_flags(cpu) (&cpu_rq(cpu)->nohz_flags) 2899 2900 extern void nohz_balance_exit_idle(struct rq *rq); 2901 #else 2902 static inline void nohz_balance_exit_idle(struct rq *rq) { } 2903 #endif 2904 2905 #if defined(CONFIG_SMP) && defined(CONFIG_NO_HZ_COMMON) 2906 extern void nohz_run_idle_balance(int cpu); 2907 #else 2908 static inline void nohz_run_idle_balance(int cpu) { } 2909 #endif 2910 2911 #ifdef CONFIG_IRQ_TIME_ACCOUNTING 2912 struct irqtime { 2913 u64 total; 2914 u64 tick_delta; 2915 u64 irq_start_time; 2916 struct u64_stats_sync sync; 2917 }; 2918 2919 DECLARE_PER_CPU(struct irqtime, cpu_irqtime); 2920 2921 /* 2922 * Returns the irqtime minus the softirq time computed by ksoftirqd. 2923 * Otherwise ksoftirqd's sum_exec_runtime is subtracted its own runtime 2924 * and never move forward. 2925 */ 2926 static inline u64 irq_time_read(int cpu) 2927 { 2928 struct irqtime *irqtime = &per_cpu(cpu_irqtime, cpu); 2929 unsigned int seq; 2930 u64 total; 2931 2932 do { 2933 seq = __u64_stats_fetch_begin(&irqtime->sync); 2934 total = irqtime->total; 2935 } while (__u64_stats_fetch_retry(&irqtime->sync, seq)); 2936 2937 return total; 2938 } 2939 #endif /* CONFIG_IRQ_TIME_ACCOUNTING */ 2940 2941 #ifdef CONFIG_CPU_FREQ 2942 DECLARE_PER_CPU(struct update_util_data __rcu *, cpufreq_update_util_data); 2943 2944 /** 2945 * cpufreq_update_util - Take a note about CPU utilization changes. 2946 * @rq: Runqueue to carry out the update for. 2947 * @flags: Update reason flags. 2948 * 2949 * This function is called by the scheduler on the CPU whose utilization is 2950 * being updated. 2951 * 2952 * It can only be called from RCU-sched read-side critical sections. 2953 * 2954 * The way cpufreq is currently arranged requires it to evaluate the CPU 2955 * performance state (frequency/voltage) on a regular basis to prevent it from 2956 * being stuck in a completely inadequate performance level for too long. 2957 * That is not guaranteed to happen if the updates are only triggered from CFS 2958 * and DL, though, because they may not be coming in if only RT tasks are 2959 * active all the time (or there are RT tasks only). 2960 * 2961 * As a workaround for that issue, this function is called periodically by the 2962 * RT sched class to trigger extra cpufreq updates to prevent it from stalling, 2963 * but that really is a band-aid. Going forward it should be replaced with 2964 * solutions targeted more specifically at RT tasks. 2965 */ 2966 static inline void cpufreq_update_util(struct rq *rq, unsigned int flags) 2967 { 2968 struct update_util_data *data; 2969 2970 data = rcu_dereference_sched(*per_cpu_ptr(&cpufreq_update_util_data, 2971 cpu_of(rq))); 2972 if (data) 2973 data->func(data, rq_clock(rq), flags); 2974 } 2975 #else 2976 static inline void cpufreq_update_util(struct rq *rq, unsigned int flags) {} 2977 #endif /* CONFIG_CPU_FREQ */ 2978 2979 #ifdef arch_scale_freq_capacity 2980 # ifndef arch_scale_freq_invariant 2981 # define arch_scale_freq_invariant() true 2982 # endif 2983 #else 2984 # define arch_scale_freq_invariant() false 2985 #endif 2986 2987 #ifdef CONFIG_SMP 2988 static inline unsigned long capacity_orig_of(int cpu) 2989 { 2990 return cpu_rq(cpu)->cpu_capacity_orig; 2991 } 2992 2993 /** 2994 * enum cpu_util_type - CPU utilization type 2995 * @FREQUENCY_UTIL: Utilization used to select frequency 2996 * @ENERGY_UTIL: Utilization used during energy calculation 2997 * 2998 * The utilization signals of all scheduling classes (CFS/RT/DL) and IRQ time 2999 * need to be aggregated differently depending on the usage made of them. This 3000 * enum is used within effective_cpu_util() to differentiate the types of 3001 * utilization expected by the callers, and adjust the aggregation accordingly. 3002 */ 3003 enum cpu_util_type { 3004 FREQUENCY_UTIL, 3005 ENERGY_UTIL, 3006 }; 3007 3008 unsigned long effective_cpu_util(int cpu, unsigned long util_cfs, 3009 enum cpu_util_type type, 3010 struct task_struct *p); 3011 3012 /* 3013 * Verify the fitness of task @p to run on @cpu taking into account the 3014 * CPU original capacity and the runtime/deadline ratio of the task. 3015 * 3016 * The function will return true if the original capacity of @cpu is 3017 * greater than or equal to task's deadline density right shifted by 3018 * (BW_SHIFT - SCHED_CAPACITY_SHIFT) and false otherwise. 3019 */ 3020 static inline bool dl_task_fits_capacity(struct task_struct *p, int cpu) 3021 { 3022 unsigned long cap = arch_scale_cpu_capacity(cpu); 3023 3024 return cap >= p->dl.dl_density >> (BW_SHIFT - SCHED_CAPACITY_SHIFT); 3025 } 3026 3027 static inline unsigned long cpu_bw_dl(struct rq *rq) 3028 { 3029 return (rq->dl.running_bw * SCHED_CAPACITY_SCALE) >> BW_SHIFT; 3030 } 3031 3032 static inline unsigned long cpu_util_dl(struct rq *rq) 3033 { 3034 return READ_ONCE(rq->avg_dl.util_avg); 3035 } 3036 3037 3038 extern unsigned long cpu_util_cfs(int cpu); 3039 extern unsigned long cpu_util_cfs_boost(int cpu); 3040 3041 static inline unsigned long cpu_util_rt(struct rq *rq) 3042 { 3043 return READ_ONCE(rq->avg_rt.util_avg); 3044 } 3045 #endif 3046 3047 #ifdef CONFIG_UCLAMP_TASK 3048 unsigned long uclamp_eff_value(struct task_struct *p, enum uclamp_id clamp_id); 3049 3050 static inline unsigned long uclamp_rq_get(struct rq *rq, 3051 enum uclamp_id clamp_id) 3052 { 3053 return READ_ONCE(rq->uclamp[clamp_id].value); 3054 } 3055 3056 static inline void uclamp_rq_set(struct rq *rq, enum uclamp_id clamp_id, 3057 unsigned int value) 3058 { 3059 WRITE_ONCE(rq->uclamp[clamp_id].value, value); 3060 } 3061 3062 static inline bool uclamp_rq_is_idle(struct rq *rq) 3063 { 3064 return rq->uclamp_flags & UCLAMP_FLAG_IDLE; 3065 } 3066 3067 /** 3068 * uclamp_rq_util_with - clamp @util with @rq and @p effective uclamp values. 3069 * @rq: The rq to clamp against. Must not be NULL. 3070 * @util: The util value to clamp. 3071 * @p: The task to clamp against. Can be NULL if you want to clamp 3072 * against @rq only. 3073 * 3074 * Clamps the passed @util to the max(@rq, @p) effective uclamp values. 3075 * 3076 * If sched_uclamp_used static key is disabled, then just return the util 3077 * without any clamping since uclamp aggregation at the rq level in the fast 3078 * path is disabled, rendering this operation a NOP. 3079 * 3080 * Use uclamp_eff_value() if you don't care about uclamp values at rq level. It 3081 * will return the correct effective uclamp value of the task even if the 3082 * static key is disabled. 3083 */ 3084 static __always_inline 3085 unsigned long uclamp_rq_util_with(struct rq *rq, unsigned long util, 3086 struct task_struct *p) 3087 { 3088 unsigned long min_util = 0; 3089 unsigned long max_util = 0; 3090 3091 if (!static_branch_likely(&sched_uclamp_used)) 3092 return util; 3093 3094 if (p) { 3095 min_util = uclamp_eff_value(p, UCLAMP_MIN); 3096 max_util = uclamp_eff_value(p, UCLAMP_MAX); 3097 3098 /* 3099 * Ignore last runnable task's max clamp, as this task will 3100 * reset it. Similarly, no need to read the rq's min clamp. 3101 */ 3102 if (uclamp_rq_is_idle(rq)) 3103 goto out; 3104 } 3105 3106 min_util = max_t(unsigned long, min_util, uclamp_rq_get(rq, UCLAMP_MIN)); 3107 max_util = max_t(unsigned long, max_util, uclamp_rq_get(rq, UCLAMP_MAX)); 3108 out: 3109 /* 3110 * Since CPU's {min,max}_util clamps are MAX aggregated considering 3111 * RUNNABLE tasks with _different_ clamps, we can end up with an 3112 * inversion. Fix it now when the clamps are applied. 3113 */ 3114 if (unlikely(min_util >= max_util)) 3115 return min_util; 3116 3117 return clamp(util, min_util, max_util); 3118 } 3119 3120 /* Is the rq being capped/throttled by uclamp_max? */ 3121 static inline bool uclamp_rq_is_capped(struct rq *rq) 3122 { 3123 unsigned long rq_util; 3124 unsigned long max_util; 3125 3126 if (!static_branch_likely(&sched_uclamp_used)) 3127 return false; 3128 3129 rq_util = cpu_util_cfs(cpu_of(rq)) + cpu_util_rt(rq); 3130 max_util = READ_ONCE(rq->uclamp[UCLAMP_MAX].value); 3131 3132 return max_util != SCHED_CAPACITY_SCALE && rq_util >= max_util; 3133 } 3134 3135 /* 3136 * When uclamp is compiled in, the aggregation at rq level is 'turned off' 3137 * by default in the fast path and only gets turned on once userspace performs 3138 * an operation that requires it. 3139 * 3140 * Returns true if userspace opted-in to use uclamp and aggregation at rq level 3141 * hence is active. 3142 */ 3143 static inline bool uclamp_is_used(void) 3144 { 3145 return static_branch_likely(&sched_uclamp_used); 3146 } 3147 #else /* CONFIG_UCLAMP_TASK */ 3148 static inline unsigned long uclamp_eff_value(struct task_struct *p, 3149 enum uclamp_id clamp_id) 3150 { 3151 if (clamp_id == UCLAMP_MIN) 3152 return 0; 3153 3154 return SCHED_CAPACITY_SCALE; 3155 } 3156 3157 static inline 3158 unsigned long uclamp_rq_util_with(struct rq *rq, unsigned long util, 3159 struct task_struct *p) 3160 { 3161 return util; 3162 } 3163 3164 static inline bool uclamp_rq_is_capped(struct rq *rq) { return false; } 3165 3166 static inline bool uclamp_is_used(void) 3167 { 3168 return false; 3169 } 3170 3171 static inline unsigned long uclamp_rq_get(struct rq *rq, 3172 enum uclamp_id clamp_id) 3173 { 3174 if (clamp_id == UCLAMP_MIN) 3175 return 0; 3176 3177 return SCHED_CAPACITY_SCALE; 3178 } 3179 3180 static inline void uclamp_rq_set(struct rq *rq, enum uclamp_id clamp_id, 3181 unsigned int value) 3182 { 3183 } 3184 3185 static inline bool uclamp_rq_is_idle(struct rq *rq) 3186 { 3187 return false; 3188 } 3189 #endif /* CONFIG_UCLAMP_TASK */ 3190 3191 #ifdef CONFIG_HAVE_SCHED_AVG_IRQ 3192 static inline unsigned long cpu_util_irq(struct rq *rq) 3193 { 3194 return rq->avg_irq.util_avg; 3195 } 3196 3197 static inline 3198 unsigned long scale_irq_capacity(unsigned long util, unsigned long irq, unsigned long max) 3199 { 3200 util *= (max - irq); 3201 util /= max; 3202 3203 return util; 3204 3205 } 3206 #else 3207 static inline unsigned long cpu_util_irq(struct rq *rq) 3208 { 3209 return 0; 3210 } 3211 3212 static inline 3213 unsigned long scale_irq_capacity(unsigned long util, unsigned long irq, unsigned long max) 3214 { 3215 return util; 3216 } 3217 #endif 3218 3219 #if defined(CONFIG_ENERGY_MODEL) && defined(CONFIG_CPU_FREQ_GOV_SCHEDUTIL) 3220 3221 #define perf_domain_span(pd) (to_cpumask(((pd)->em_pd->cpus))) 3222 3223 DECLARE_STATIC_KEY_FALSE(sched_energy_present); 3224 3225 static inline bool sched_energy_enabled(void) 3226 { 3227 return static_branch_unlikely(&sched_energy_present); 3228 } 3229 3230 #else /* ! (CONFIG_ENERGY_MODEL && CONFIG_CPU_FREQ_GOV_SCHEDUTIL) */ 3231 3232 #define perf_domain_span(pd) NULL 3233 static inline bool sched_energy_enabled(void) { return false; } 3234 3235 #endif /* CONFIG_ENERGY_MODEL && CONFIG_CPU_FREQ_GOV_SCHEDUTIL */ 3236 3237 #ifdef CONFIG_MEMBARRIER 3238 /* 3239 * The scheduler provides memory barriers required by membarrier between: 3240 * - prior user-space memory accesses and store to rq->membarrier_state, 3241 * - store to rq->membarrier_state and following user-space memory accesses. 3242 * In the same way it provides those guarantees around store to rq->curr. 3243 */ 3244 static inline void membarrier_switch_mm(struct rq *rq, 3245 struct mm_struct *prev_mm, 3246 struct mm_struct *next_mm) 3247 { 3248 int membarrier_state; 3249 3250 if (prev_mm == next_mm) 3251 return; 3252 3253 membarrier_state = atomic_read(&next_mm->membarrier_state); 3254 if (READ_ONCE(rq->membarrier_state) == membarrier_state) 3255 return; 3256 3257 WRITE_ONCE(rq->membarrier_state, membarrier_state); 3258 } 3259 #else 3260 static inline void membarrier_switch_mm(struct rq *rq, 3261 struct mm_struct *prev_mm, 3262 struct mm_struct *next_mm) 3263 { 3264 } 3265 #endif 3266 3267 #ifdef CONFIG_SMP 3268 static inline bool is_per_cpu_kthread(struct task_struct *p) 3269 { 3270 if (!(p->flags & PF_KTHREAD)) 3271 return false; 3272 3273 if (p->nr_cpus_allowed != 1) 3274 return false; 3275 3276 return true; 3277 } 3278 #endif 3279 3280 extern void swake_up_all_locked(struct swait_queue_head *q); 3281 extern void __prepare_to_swait(struct swait_queue_head *q, struct swait_queue *wait); 3282 3283 extern int try_to_wake_up(struct task_struct *tsk, unsigned int state, int wake_flags); 3284 3285 #ifdef CONFIG_PREEMPT_DYNAMIC 3286 extern int preempt_dynamic_mode; 3287 extern int sched_dynamic_mode(const char *str); 3288 extern void sched_dynamic_update(int mode); 3289 #endif 3290 3291 #ifdef CONFIG_SCHED_MM_CID 3292 3293 #define SCHED_MM_CID_PERIOD_NS (100ULL * 1000000) /* 100ms */ 3294 #define MM_CID_SCAN_DELAY 100 /* 100ms */ 3295 3296 extern raw_spinlock_t cid_lock; 3297 extern int use_cid_lock; 3298 3299 extern void sched_mm_cid_migrate_from(struct task_struct *t); 3300 extern void sched_mm_cid_migrate_to(struct rq *dst_rq, struct task_struct *t); 3301 extern void task_tick_mm_cid(struct rq *rq, struct task_struct *curr); 3302 extern void init_sched_mm_cid(struct task_struct *t); 3303 3304 static inline void __mm_cid_put(struct mm_struct *mm, int cid) 3305 { 3306 if (cid < 0) 3307 return; 3308 cpumask_clear_cpu(cid, mm_cidmask(mm)); 3309 } 3310 3311 /* 3312 * The per-mm/cpu cid can have the MM_CID_LAZY_PUT flag set or transition to 3313 * the MM_CID_UNSET state without holding the rq lock, but the rq lock needs to 3314 * be held to transition to other states. 3315 * 3316 * State transitions synchronized with cmpxchg or try_cmpxchg need to be 3317 * consistent across cpus, which prevents use of this_cpu_cmpxchg. 3318 */ 3319 static inline void mm_cid_put_lazy(struct task_struct *t) 3320 { 3321 struct mm_struct *mm = t->mm; 3322 struct mm_cid __percpu *pcpu_cid = mm->pcpu_cid; 3323 int cid; 3324 3325 lockdep_assert_irqs_disabled(); 3326 cid = __this_cpu_read(pcpu_cid->cid); 3327 if (!mm_cid_is_lazy_put(cid) || 3328 !try_cmpxchg(&this_cpu_ptr(pcpu_cid)->cid, &cid, MM_CID_UNSET)) 3329 return; 3330 __mm_cid_put(mm, mm_cid_clear_lazy_put(cid)); 3331 } 3332 3333 static inline int mm_cid_pcpu_unset(struct mm_struct *mm) 3334 { 3335 struct mm_cid __percpu *pcpu_cid = mm->pcpu_cid; 3336 int cid, res; 3337 3338 lockdep_assert_irqs_disabled(); 3339 cid = __this_cpu_read(pcpu_cid->cid); 3340 for (;;) { 3341 if (mm_cid_is_unset(cid)) 3342 return MM_CID_UNSET; 3343 /* 3344 * Attempt transition from valid or lazy-put to unset. 3345 */ 3346 res = cmpxchg(&this_cpu_ptr(pcpu_cid)->cid, cid, MM_CID_UNSET); 3347 if (res == cid) 3348 break; 3349 cid = res; 3350 } 3351 return cid; 3352 } 3353 3354 static inline void mm_cid_put(struct mm_struct *mm) 3355 { 3356 int cid; 3357 3358 lockdep_assert_irqs_disabled(); 3359 cid = mm_cid_pcpu_unset(mm); 3360 if (cid == MM_CID_UNSET) 3361 return; 3362 __mm_cid_put(mm, mm_cid_clear_lazy_put(cid)); 3363 } 3364 3365 static inline int __mm_cid_try_get(struct mm_struct *mm) 3366 { 3367 struct cpumask *cpumask; 3368 int cid; 3369 3370 cpumask = mm_cidmask(mm); 3371 /* 3372 * Retry finding first zero bit if the mask is temporarily 3373 * filled. This only happens during concurrent remote-clear 3374 * which owns a cid without holding a rq lock. 3375 */ 3376 for (;;) { 3377 cid = cpumask_first_zero(cpumask); 3378 if (cid < nr_cpu_ids) 3379 break; 3380 cpu_relax(); 3381 } 3382 if (cpumask_test_and_set_cpu(cid, cpumask)) 3383 return -1; 3384 return cid; 3385 } 3386 3387 /* 3388 * Save a snapshot of the current runqueue time of this cpu 3389 * with the per-cpu cid value, allowing to estimate how recently it was used. 3390 */ 3391 static inline void mm_cid_snapshot_time(struct rq *rq, struct mm_struct *mm) 3392 { 3393 struct mm_cid *pcpu_cid = per_cpu_ptr(mm->pcpu_cid, cpu_of(rq)); 3394 3395 lockdep_assert_rq_held(rq); 3396 WRITE_ONCE(pcpu_cid->time, rq->clock); 3397 } 3398 3399 static inline int __mm_cid_get(struct rq *rq, struct mm_struct *mm) 3400 { 3401 int cid; 3402 3403 /* 3404 * All allocations (even those using the cid_lock) are lock-free. If 3405 * use_cid_lock is set, hold the cid_lock to perform cid allocation to 3406 * guarantee forward progress. 3407 */ 3408 if (!READ_ONCE(use_cid_lock)) { 3409 cid = __mm_cid_try_get(mm); 3410 if (cid >= 0) 3411 goto end; 3412 raw_spin_lock(&cid_lock); 3413 } else { 3414 raw_spin_lock(&cid_lock); 3415 cid = __mm_cid_try_get(mm); 3416 if (cid >= 0) 3417 goto unlock; 3418 } 3419 3420 /* 3421 * cid concurrently allocated. Retry while forcing following 3422 * allocations to use the cid_lock to ensure forward progress. 3423 */ 3424 WRITE_ONCE(use_cid_lock, 1); 3425 /* 3426 * Set use_cid_lock before allocation. Only care about program order 3427 * because this is only required for forward progress. 3428 */ 3429 barrier(); 3430 /* 3431 * Retry until it succeeds. It is guaranteed to eventually succeed once 3432 * all newcoming allocations observe the use_cid_lock flag set. 3433 */ 3434 do { 3435 cid = __mm_cid_try_get(mm); 3436 cpu_relax(); 3437 } while (cid < 0); 3438 /* 3439 * Allocate before clearing use_cid_lock. Only care about 3440 * program order because this is for forward progress. 3441 */ 3442 barrier(); 3443 WRITE_ONCE(use_cid_lock, 0); 3444 unlock: 3445 raw_spin_unlock(&cid_lock); 3446 end: 3447 mm_cid_snapshot_time(rq, mm); 3448 return cid; 3449 } 3450 3451 static inline int mm_cid_get(struct rq *rq, struct mm_struct *mm) 3452 { 3453 struct mm_cid __percpu *pcpu_cid = mm->pcpu_cid; 3454 struct cpumask *cpumask; 3455 int cid; 3456 3457 lockdep_assert_rq_held(rq); 3458 cpumask = mm_cidmask(mm); 3459 cid = __this_cpu_read(pcpu_cid->cid); 3460 if (mm_cid_is_valid(cid)) { 3461 mm_cid_snapshot_time(rq, mm); 3462 return cid; 3463 } 3464 if (mm_cid_is_lazy_put(cid)) { 3465 if (try_cmpxchg(&this_cpu_ptr(pcpu_cid)->cid, &cid, MM_CID_UNSET)) 3466 __mm_cid_put(mm, mm_cid_clear_lazy_put(cid)); 3467 } 3468 cid = __mm_cid_get(rq, mm); 3469 __this_cpu_write(pcpu_cid->cid, cid); 3470 return cid; 3471 } 3472 3473 static inline void switch_mm_cid(struct rq *rq, 3474 struct task_struct *prev, 3475 struct task_struct *next) 3476 { 3477 /* 3478 * Provide a memory barrier between rq->curr store and load of 3479 * {prev,next}->mm->pcpu_cid[cpu] on rq->curr->mm transition. 3480 * 3481 * Should be adapted if context_switch() is modified. 3482 */ 3483 if (!next->mm) { // to kernel 3484 /* 3485 * user -> kernel transition does not guarantee a barrier, but 3486 * we can use the fact that it performs an atomic operation in 3487 * mmgrab(). 3488 */ 3489 if (prev->mm) // from user 3490 smp_mb__after_mmgrab(); 3491 /* 3492 * kernel -> kernel transition does not change rq->curr->mm 3493 * state. It stays NULL. 3494 */ 3495 } else { // to user 3496 /* 3497 * kernel -> user transition does not provide a barrier 3498 * between rq->curr store and load of {prev,next}->mm->pcpu_cid[cpu]. 3499 * Provide it here. 3500 */ 3501 if (!prev->mm) { // from kernel 3502 smp_mb(); 3503 } else { // from user 3504 /* 3505 * user->user transition relies on an implicit 3506 * memory barrier in switch_mm() when 3507 * current->mm changes. If the architecture 3508 * switch_mm() does not have an implicit memory 3509 * barrier, it is emitted here. If current->mm 3510 * is unchanged, no barrier is needed. 3511 */ 3512 smp_mb__after_switch_mm(); 3513 } 3514 } 3515 if (prev->mm_cid_active) { 3516 mm_cid_snapshot_time(rq, prev->mm); 3517 mm_cid_put_lazy(prev); 3518 prev->mm_cid = -1; 3519 } 3520 if (next->mm_cid_active) 3521 next->last_mm_cid = next->mm_cid = mm_cid_get(rq, next->mm); 3522 } 3523 3524 #else 3525 static inline void switch_mm_cid(struct rq *rq, struct task_struct *prev, struct task_struct *next) { } 3526 static inline void sched_mm_cid_migrate_from(struct task_struct *t) { } 3527 static inline void sched_mm_cid_migrate_to(struct rq *dst_rq, struct task_struct *t) { } 3528 static inline void task_tick_mm_cid(struct rq *rq, struct task_struct *curr) { } 3529 static inline void init_sched_mm_cid(struct task_struct *t) { } 3530 #endif 3531 3532 extern u64 avg_vruntime(struct cfs_rq *cfs_rq); 3533 extern int entity_eligible(struct cfs_rq *cfs_rq, struct sched_entity *se); 3534 3535 #endif /* _KERNEL_SCHED_SCHED_H */ 3536