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 void __dl_clear_params(struct task_struct *p); 290 291 static inline int dl_bandwidth_enabled(void) 292 { 293 return sysctl_sched_rt_runtime >= 0; 294 } 295 296 /* 297 * To keep the bandwidth of -deadline tasks under control 298 * we need some place where: 299 * - store the maximum -deadline bandwidth of each cpu; 300 * - cache the fraction of bandwidth that is currently allocated in 301 * each root domain; 302 * 303 * This is all done in the data structure below. It is similar to the 304 * one used for RT-throttling (rt_bandwidth), with the main difference 305 * that, since here we are only interested in admission control, we 306 * do not decrease any runtime while the group "executes", neither we 307 * need a timer to replenish it. 308 * 309 * With respect to SMP, bandwidth is given on a per root domain basis, 310 * meaning that: 311 * - bw (< 100%) is the deadline bandwidth of each CPU; 312 * - total_bw is the currently allocated bandwidth in each root domain; 313 */ 314 struct dl_bw { 315 raw_spinlock_t lock; 316 u64 bw; 317 u64 total_bw; 318 }; 319 320 extern void init_dl_bw(struct dl_bw *dl_b); 321 extern int sched_dl_global_validate(void); 322 extern void sched_dl_do_global(void); 323 extern int sched_dl_overflow(struct task_struct *p, int policy, const struct sched_attr *attr); 324 extern void __setparam_dl(struct task_struct *p, const struct sched_attr *attr); 325 extern void __getparam_dl(struct task_struct *p, struct sched_attr *attr); 326 extern bool __checkparam_dl(const struct sched_attr *attr); 327 extern bool dl_param_changed(struct task_struct *p, const struct sched_attr *attr); 328 extern int dl_cpuset_cpumask_can_shrink(const struct cpumask *cur, const struct cpumask *trial); 329 extern int dl_bw_check_overflow(int cpu); 330 331 #ifdef CONFIG_CGROUP_SCHED 332 333 struct cfs_rq; 334 struct rt_rq; 335 336 extern struct list_head task_groups; 337 338 struct cfs_bandwidth { 339 #ifdef CONFIG_CFS_BANDWIDTH 340 raw_spinlock_t lock; 341 ktime_t period; 342 u64 quota; 343 u64 runtime; 344 u64 burst; 345 u64 runtime_snap; 346 s64 hierarchical_quota; 347 348 u8 idle; 349 u8 period_active; 350 u8 slack_started; 351 struct hrtimer period_timer; 352 struct hrtimer slack_timer; 353 struct list_head throttled_cfs_rq; 354 355 /* Statistics: */ 356 int nr_periods; 357 int nr_throttled; 358 int nr_burst; 359 u64 throttled_time; 360 u64 burst_time; 361 #endif 362 }; 363 364 /* Task group related information */ 365 struct task_group { 366 struct cgroup_subsys_state css; 367 368 #ifdef CONFIG_FAIR_GROUP_SCHED 369 /* schedulable entities of this group on each CPU */ 370 struct sched_entity **se; 371 /* runqueue "owned" by this group on each CPU */ 372 struct cfs_rq **cfs_rq; 373 unsigned long shares; 374 375 /* A positive value indicates that this is a SCHED_IDLE group. */ 376 int idle; 377 378 #ifdef CONFIG_SMP 379 /* 380 * load_avg can be heavily contended at clock tick time, so put 381 * it in its own cacheline separated from the fields above which 382 * will also be accessed at each tick. 383 */ 384 atomic_long_t load_avg ____cacheline_aligned; 385 #endif 386 #endif 387 388 #ifdef CONFIG_RT_GROUP_SCHED 389 struct sched_rt_entity **rt_se; 390 struct rt_rq **rt_rq; 391 392 struct rt_bandwidth rt_bandwidth; 393 #endif 394 395 struct rcu_head rcu; 396 struct list_head list; 397 398 struct task_group *parent; 399 struct list_head siblings; 400 struct list_head children; 401 402 #ifdef CONFIG_SCHED_AUTOGROUP 403 struct autogroup *autogroup; 404 #endif 405 406 struct cfs_bandwidth cfs_bandwidth; 407 408 #ifdef CONFIG_UCLAMP_TASK_GROUP 409 /* The two decimal precision [%] value requested from user-space */ 410 unsigned int uclamp_pct[UCLAMP_CNT]; 411 /* Clamp values requested for a task group */ 412 struct uclamp_se uclamp_req[UCLAMP_CNT]; 413 /* Effective clamp values used for a task group */ 414 struct uclamp_se uclamp[UCLAMP_CNT]; 415 #endif 416 417 }; 418 419 #ifdef CONFIG_FAIR_GROUP_SCHED 420 #define ROOT_TASK_GROUP_LOAD NICE_0_LOAD 421 422 /* 423 * A weight of 0 or 1 can cause arithmetics problems. 424 * A weight of a cfs_rq is the sum of weights of which entities 425 * are queued on this cfs_rq, so a weight of a entity should not be 426 * too large, so as the shares value of a task group. 427 * (The default weight is 1024 - so there's no practical 428 * limitation from this.) 429 */ 430 #define MIN_SHARES (1UL << 1) 431 #define MAX_SHARES (1UL << 18) 432 #endif 433 434 typedef int (*tg_visitor)(struct task_group *, void *); 435 436 extern int walk_tg_tree_from(struct task_group *from, 437 tg_visitor down, tg_visitor up, void *data); 438 439 /* 440 * Iterate the full tree, calling @down when first entering a node and @up when 441 * leaving it for the final time. 442 * 443 * Caller must hold rcu_lock or sufficient equivalent. 444 */ 445 static inline int walk_tg_tree(tg_visitor down, tg_visitor up, void *data) 446 { 447 return walk_tg_tree_from(&root_task_group, down, up, data); 448 } 449 450 extern int tg_nop(struct task_group *tg, void *data); 451 452 extern void free_fair_sched_group(struct task_group *tg); 453 extern int alloc_fair_sched_group(struct task_group *tg, struct task_group *parent); 454 extern void online_fair_sched_group(struct task_group *tg); 455 extern void unregister_fair_sched_group(struct task_group *tg); 456 extern void init_tg_cfs_entry(struct task_group *tg, struct cfs_rq *cfs_rq, 457 struct sched_entity *se, int cpu, 458 struct sched_entity *parent); 459 extern void init_cfs_bandwidth(struct cfs_bandwidth *cfs_b, struct cfs_bandwidth *parent); 460 461 extern void __refill_cfs_bandwidth_runtime(struct cfs_bandwidth *cfs_b); 462 extern void start_cfs_bandwidth(struct cfs_bandwidth *cfs_b); 463 extern void unthrottle_cfs_rq(struct cfs_rq *cfs_rq); 464 extern bool cfs_task_bw_constrained(struct task_struct *p); 465 466 extern void init_tg_rt_entry(struct task_group *tg, struct rt_rq *rt_rq, 467 struct sched_rt_entity *rt_se, int cpu, 468 struct sched_rt_entity *parent); 469 extern int sched_group_set_rt_runtime(struct task_group *tg, long rt_runtime_us); 470 extern int sched_group_set_rt_period(struct task_group *tg, u64 rt_period_us); 471 extern long sched_group_rt_runtime(struct task_group *tg); 472 extern long sched_group_rt_period(struct task_group *tg); 473 extern int sched_rt_can_attach(struct task_group *tg, struct task_struct *tsk); 474 475 extern struct task_group *sched_create_group(struct task_group *parent); 476 extern void sched_online_group(struct task_group *tg, 477 struct task_group *parent); 478 extern void sched_destroy_group(struct task_group *tg); 479 extern void sched_release_group(struct task_group *tg); 480 481 extern void sched_move_task(struct task_struct *tsk); 482 483 #ifdef CONFIG_FAIR_GROUP_SCHED 484 extern int sched_group_set_shares(struct task_group *tg, unsigned long shares); 485 486 extern int sched_group_set_idle(struct task_group *tg, long idle); 487 488 #ifdef CONFIG_SMP 489 extern void set_task_rq_fair(struct sched_entity *se, 490 struct cfs_rq *prev, struct cfs_rq *next); 491 #else /* !CONFIG_SMP */ 492 static inline void set_task_rq_fair(struct sched_entity *se, 493 struct cfs_rq *prev, struct cfs_rq *next) { } 494 #endif /* CONFIG_SMP */ 495 #endif /* CONFIG_FAIR_GROUP_SCHED */ 496 497 #else /* CONFIG_CGROUP_SCHED */ 498 499 struct cfs_bandwidth { }; 500 static inline bool cfs_task_bw_constrained(struct task_struct *p) { return false; } 501 502 #endif /* CONFIG_CGROUP_SCHED */ 503 504 extern void unregister_rt_sched_group(struct task_group *tg); 505 extern void free_rt_sched_group(struct task_group *tg); 506 extern int alloc_rt_sched_group(struct task_group *tg, struct task_group *parent); 507 508 /* 509 * u64_u32_load/u64_u32_store 510 * 511 * Use a copy of a u64 value to protect against data race. This is only 512 * applicable for 32-bits architectures. 513 */ 514 #ifdef CONFIG_64BIT 515 # define u64_u32_load_copy(var, copy) var 516 # define u64_u32_store_copy(var, copy, val) (var = val) 517 #else 518 # define u64_u32_load_copy(var, copy) \ 519 ({ \ 520 u64 __val, __val_copy; \ 521 do { \ 522 __val_copy = copy; \ 523 /* \ 524 * paired with u64_u32_store_copy(), ordering access \ 525 * to var and copy. \ 526 */ \ 527 smp_rmb(); \ 528 __val = var; \ 529 } while (__val != __val_copy); \ 530 __val; \ 531 }) 532 # define u64_u32_store_copy(var, copy, val) \ 533 do { \ 534 typeof(val) __val = (val); \ 535 var = __val; \ 536 /* \ 537 * paired with u64_u32_load_copy(), ordering access to var and \ 538 * copy. \ 539 */ \ 540 smp_wmb(); \ 541 copy = __val; \ 542 } while (0) 543 #endif 544 # define u64_u32_load(var) u64_u32_load_copy(var, var##_copy) 545 # define u64_u32_store(var, val) u64_u32_store_copy(var, var##_copy, val) 546 547 /* CFS-related fields in a runqueue */ 548 struct cfs_rq { 549 struct load_weight load; 550 unsigned int nr_running; 551 unsigned int h_nr_running; /* SCHED_{NORMAL,BATCH,IDLE} */ 552 unsigned int idle_nr_running; /* SCHED_IDLE */ 553 unsigned int idle_h_nr_running; /* SCHED_IDLE */ 554 555 s64 avg_vruntime; 556 u64 avg_load; 557 558 u64 exec_clock; 559 u64 min_vruntime; 560 #ifdef CONFIG_SCHED_CORE 561 unsigned int forceidle_seq; 562 u64 min_vruntime_fi; 563 #endif 564 565 #ifndef CONFIG_64BIT 566 u64 min_vruntime_copy; 567 #endif 568 569 struct rb_root_cached tasks_timeline; 570 571 /* 572 * 'curr' points to currently running entity on this cfs_rq. 573 * It is set to NULL otherwise (i.e when none are currently running). 574 */ 575 struct sched_entity *curr; 576 struct sched_entity *next; 577 578 #ifdef CONFIG_SCHED_DEBUG 579 unsigned int nr_spread_over; 580 #endif 581 582 #ifdef CONFIG_SMP 583 /* 584 * CFS load tracking 585 */ 586 struct sched_avg avg; 587 #ifndef CONFIG_64BIT 588 u64 last_update_time_copy; 589 #endif 590 struct { 591 raw_spinlock_t lock ____cacheline_aligned; 592 int nr; 593 unsigned long load_avg; 594 unsigned long util_avg; 595 unsigned long runnable_avg; 596 } removed; 597 598 #ifdef CONFIG_FAIR_GROUP_SCHED 599 unsigned long tg_load_avg_contrib; 600 long propagate; 601 long prop_runnable_sum; 602 603 /* 604 * h_load = weight * f(tg) 605 * 606 * Where f(tg) is the recursive weight fraction assigned to 607 * this group. 608 */ 609 unsigned long h_load; 610 u64 last_h_load_update; 611 struct sched_entity *h_load_next; 612 #endif /* CONFIG_FAIR_GROUP_SCHED */ 613 #endif /* CONFIG_SMP */ 614 615 #ifdef CONFIG_FAIR_GROUP_SCHED 616 struct rq *rq; /* CPU runqueue to which this cfs_rq is attached */ 617 618 /* 619 * leaf cfs_rqs are those that hold tasks (lowest schedulable entity in 620 * a hierarchy). Non-leaf lrqs hold other higher schedulable entities 621 * (like users, containers etc.) 622 * 623 * leaf_cfs_rq_list ties together list of leaf cfs_rq's in a CPU. 624 * This list is used during load balance. 625 */ 626 int on_list; 627 struct list_head leaf_cfs_rq_list; 628 struct task_group *tg; /* group that "owns" this runqueue */ 629 630 /* Locally cached copy of our task_group's idle value */ 631 int idle; 632 633 #ifdef CONFIG_CFS_BANDWIDTH 634 int runtime_enabled; 635 s64 runtime_remaining; 636 637 u64 throttled_pelt_idle; 638 #ifndef CONFIG_64BIT 639 u64 throttled_pelt_idle_copy; 640 #endif 641 u64 throttled_clock; 642 u64 throttled_clock_pelt; 643 u64 throttled_clock_pelt_time; 644 u64 throttled_clock_self; 645 u64 throttled_clock_self_time; 646 int throttled; 647 int throttle_count; 648 struct list_head throttled_list; 649 #ifdef CONFIG_SMP 650 struct list_head throttled_csd_list; 651 #endif 652 #endif /* CONFIG_CFS_BANDWIDTH */ 653 #endif /* CONFIG_FAIR_GROUP_SCHED */ 654 }; 655 656 static inline int rt_bandwidth_enabled(void) 657 { 658 return sysctl_sched_rt_runtime >= 0; 659 } 660 661 /* RT IPI pull logic requires IRQ_WORK */ 662 #if defined(CONFIG_IRQ_WORK) && defined(CONFIG_SMP) 663 # define HAVE_RT_PUSH_IPI 664 #endif 665 666 /* Real-Time classes' related field in a runqueue: */ 667 struct rt_rq { 668 struct rt_prio_array active; 669 unsigned int rt_nr_running; 670 unsigned int rr_nr_running; 671 #if defined CONFIG_SMP || defined CONFIG_RT_GROUP_SCHED 672 struct { 673 int curr; /* highest queued rt task prio */ 674 #ifdef CONFIG_SMP 675 int next; /* next highest */ 676 #endif 677 } highest_prio; 678 #endif 679 #ifdef CONFIG_SMP 680 unsigned int rt_nr_migratory; 681 unsigned int rt_nr_total; 682 int overloaded; 683 struct plist_head pushable_tasks; 684 685 #endif /* CONFIG_SMP */ 686 int rt_queued; 687 688 int rt_throttled; 689 u64 rt_time; 690 u64 rt_runtime; 691 /* Nests inside the rq lock: */ 692 raw_spinlock_t rt_runtime_lock; 693 694 #ifdef CONFIG_RT_GROUP_SCHED 695 unsigned int rt_nr_boosted; 696 697 struct rq *rq; 698 struct task_group *tg; 699 #endif 700 }; 701 702 static inline bool rt_rq_is_runnable(struct rt_rq *rt_rq) 703 { 704 return rt_rq->rt_queued && rt_rq->rt_nr_running; 705 } 706 707 /* Deadline class' related fields in a runqueue */ 708 struct dl_rq { 709 /* runqueue is an rbtree, ordered by deadline */ 710 struct rb_root_cached root; 711 712 unsigned int dl_nr_running; 713 714 #ifdef CONFIG_SMP 715 /* 716 * Deadline values of the currently executing and the 717 * earliest ready task on this rq. Caching these facilitates 718 * the decision whether or not a ready but not running task 719 * should migrate somewhere else. 720 */ 721 struct { 722 u64 curr; 723 u64 next; 724 } earliest_dl; 725 726 unsigned int dl_nr_migratory; 727 int overloaded; 728 729 /* 730 * Tasks on this rq that can be pushed away. They are kept in 731 * an rb-tree, ordered by tasks' deadlines, with caching 732 * of the leftmost (earliest deadline) element. 733 */ 734 struct rb_root_cached pushable_dl_tasks_root; 735 #else 736 struct dl_bw dl_bw; 737 #endif 738 /* 739 * "Active utilization" for this runqueue: increased when a 740 * task wakes up (becomes TASK_RUNNING) and decreased when a 741 * task blocks 742 */ 743 u64 running_bw; 744 745 /* 746 * Utilization of the tasks "assigned" to this runqueue (including 747 * the tasks that are in runqueue and the tasks that executed on this 748 * CPU and blocked). Increased when a task moves to this runqueue, and 749 * decreased when the task moves away (migrates, changes scheduling 750 * policy, or terminates). 751 * This is needed to compute the "inactive utilization" for the 752 * runqueue (inactive utilization = this_bw - running_bw). 753 */ 754 u64 this_bw; 755 u64 extra_bw; 756 757 /* 758 * Maximum available bandwidth for reclaiming by SCHED_FLAG_RECLAIM 759 * tasks of this rq. Used in calculation of reclaimable bandwidth(GRUB). 760 */ 761 u64 max_bw; 762 763 /* 764 * Inverse of the fraction of CPU utilization that can be reclaimed 765 * by the GRUB algorithm. 766 */ 767 u64 bw_ratio; 768 }; 769 770 #ifdef CONFIG_FAIR_GROUP_SCHED 771 /* An entity is a task if it doesn't "own" a runqueue */ 772 #define entity_is_task(se) (!se->my_q) 773 774 static inline void se_update_runnable(struct sched_entity *se) 775 { 776 if (!entity_is_task(se)) 777 se->runnable_weight = se->my_q->h_nr_running; 778 } 779 780 static inline long se_runnable(struct sched_entity *se) 781 { 782 if (entity_is_task(se)) 783 return !!se->on_rq; 784 else 785 return se->runnable_weight; 786 } 787 788 #else 789 #define entity_is_task(se) 1 790 791 static inline void se_update_runnable(struct sched_entity *se) {} 792 793 static inline long se_runnable(struct sched_entity *se) 794 { 795 return !!se->on_rq; 796 } 797 #endif 798 799 #ifdef CONFIG_SMP 800 /* 801 * XXX we want to get rid of these helpers and use the full load resolution. 802 */ 803 static inline long se_weight(struct sched_entity *se) 804 { 805 return scale_load_down(se->load.weight); 806 } 807 808 809 static inline bool sched_asym_prefer(int a, int b) 810 { 811 return arch_asym_cpu_priority(a) > arch_asym_cpu_priority(b); 812 } 813 814 struct perf_domain { 815 struct em_perf_domain *em_pd; 816 struct perf_domain *next; 817 struct rcu_head rcu; 818 }; 819 820 /* Scheduling group status flags */ 821 #define SG_OVERLOAD 0x1 /* More than one runnable task on a CPU. */ 822 #define SG_OVERUTILIZED 0x2 /* One or more CPUs are over-utilized. */ 823 824 /* 825 * We add the notion of a root-domain which will be used to define per-domain 826 * variables. Each exclusive cpuset essentially defines an island domain by 827 * fully partitioning the member CPUs from any other cpuset. Whenever a new 828 * exclusive cpuset is created, we also create and attach a new root-domain 829 * object. 830 * 831 */ 832 struct root_domain { 833 atomic_t refcount; 834 atomic_t rto_count; 835 struct rcu_head rcu; 836 cpumask_var_t span; 837 cpumask_var_t online; 838 839 /* 840 * Indicate pullable load on at least one CPU, e.g: 841 * - More than one runnable task 842 * - Running task is misfit 843 */ 844 int overload; 845 846 /* Indicate one or more cpus over-utilized (tipping point) */ 847 int overutilized; 848 849 /* 850 * The bit corresponding to a CPU gets set here if such CPU has more 851 * than one runnable -deadline task (as it is below for RT tasks). 852 */ 853 cpumask_var_t dlo_mask; 854 atomic_t dlo_count; 855 struct dl_bw dl_bw; 856 struct cpudl cpudl; 857 858 /* 859 * Indicate whether a root_domain's dl_bw has been checked or 860 * updated. It's monotonously increasing value. 861 * 862 * Also, some corner cases, like 'wrap around' is dangerous, but given 863 * that u64 is 'big enough'. So that shouldn't be a concern. 864 */ 865 u64 visit_gen; 866 867 #ifdef HAVE_RT_PUSH_IPI 868 /* 869 * For IPI pull requests, loop across the rto_mask. 870 */ 871 struct irq_work rto_push_work; 872 raw_spinlock_t rto_lock; 873 /* These are only updated and read within rto_lock */ 874 int rto_loop; 875 int rto_cpu; 876 /* These atomics are updated outside of a lock */ 877 atomic_t rto_loop_next; 878 atomic_t rto_loop_start; 879 #endif 880 /* 881 * The "RT overload" flag: it gets set if a CPU has more than 882 * one runnable RT task. 883 */ 884 cpumask_var_t rto_mask; 885 struct cpupri cpupri; 886 887 unsigned long max_cpu_capacity; 888 889 /* 890 * NULL-terminated list of performance domains intersecting with the 891 * CPUs of the rd. Protected by RCU. 892 */ 893 struct perf_domain __rcu *pd; 894 }; 895 896 extern void init_defrootdomain(void); 897 extern int sched_init_domains(const struct cpumask *cpu_map); 898 extern void rq_attach_root(struct rq *rq, struct root_domain *rd); 899 extern void sched_get_rd(struct root_domain *rd); 900 extern void sched_put_rd(struct root_domain *rd); 901 902 #ifdef HAVE_RT_PUSH_IPI 903 extern void rto_push_irq_work_func(struct irq_work *work); 904 #endif 905 #endif /* CONFIG_SMP */ 906 907 #ifdef CONFIG_UCLAMP_TASK 908 /* 909 * struct uclamp_bucket - Utilization clamp bucket 910 * @value: utilization clamp value for tasks on this clamp bucket 911 * @tasks: number of RUNNABLE tasks on this clamp bucket 912 * 913 * Keep track of how many tasks are RUNNABLE for a given utilization 914 * clamp value. 915 */ 916 struct uclamp_bucket { 917 unsigned long value : bits_per(SCHED_CAPACITY_SCALE); 918 unsigned long tasks : BITS_PER_LONG - bits_per(SCHED_CAPACITY_SCALE); 919 }; 920 921 /* 922 * struct uclamp_rq - rq's utilization clamp 923 * @value: currently active clamp values for a rq 924 * @bucket: utilization clamp buckets affecting a rq 925 * 926 * Keep track of RUNNABLE tasks on a rq to aggregate their clamp values. 927 * A clamp value is affecting a rq when there is at least one task RUNNABLE 928 * (or actually running) with that value. 929 * 930 * There are up to UCLAMP_CNT possible different clamp values, currently there 931 * are only two: minimum utilization and maximum utilization. 932 * 933 * All utilization clamping values are MAX aggregated, since: 934 * - for util_min: we want to run the CPU at least at the max of the minimum 935 * utilization required by its currently RUNNABLE tasks. 936 * - for util_max: we want to allow the CPU to run up to the max of the 937 * maximum utilization allowed by its currently RUNNABLE tasks. 938 * 939 * Since on each system we expect only a limited number of different 940 * utilization clamp values (UCLAMP_BUCKETS), use a simple array to track 941 * the metrics required to compute all the per-rq utilization clamp values. 942 */ 943 struct uclamp_rq { 944 unsigned int value; 945 struct uclamp_bucket bucket[UCLAMP_BUCKETS]; 946 }; 947 948 DECLARE_STATIC_KEY_FALSE(sched_uclamp_used); 949 #endif /* CONFIG_UCLAMP_TASK */ 950 951 struct rq; 952 struct balance_callback { 953 struct balance_callback *next; 954 void (*func)(struct rq *rq); 955 }; 956 957 /* 958 * This is the main, per-CPU runqueue data structure. 959 * 960 * Locking rule: those places that want to lock multiple runqueues 961 * (such as the load balancing or the thread migration code), lock 962 * acquire operations must be ordered by ascending &runqueue. 963 */ 964 struct rq { 965 /* runqueue lock: */ 966 raw_spinlock_t __lock; 967 968 /* 969 * nr_running and cpu_load should be in the same cacheline because 970 * remote CPUs use both these fields when doing load calculation. 971 */ 972 unsigned int nr_running; 973 #ifdef CONFIG_NUMA_BALANCING 974 unsigned int nr_numa_running; 975 unsigned int nr_preferred_running; 976 unsigned int numa_migrate_on; 977 #endif 978 #ifdef CONFIG_NO_HZ_COMMON 979 #ifdef CONFIG_SMP 980 unsigned long last_blocked_load_update_tick; 981 unsigned int has_blocked_load; 982 call_single_data_t nohz_csd; 983 #endif /* CONFIG_SMP */ 984 unsigned int nohz_tick_stopped; 985 atomic_t nohz_flags; 986 #endif /* CONFIG_NO_HZ_COMMON */ 987 988 #ifdef CONFIG_SMP 989 unsigned int ttwu_pending; 990 #endif 991 u64 nr_switches; 992 993 #ifdef CONFIG_UCLAMP_TASK 994 /* Utilization clamp values based on CPU's RUNNABLE tasks */ 995 struct uclamp_rq uclamp[UCLAMP_CNT] ____cacheline_aligned; 996 unsigned int uclamp_flags; 997 #define UCLAMP_FLAG_IDLE 0x01 998 #endif 999 1000 struct cfs_rq cfs; 1001 struct rt_rq rt; 1002 struct dl_rq dl; 1003 1004 #ifdef CONFIG_FAIR_GROUP_SCHED 1005 /* list of leaf cfs_rq on this CPU: */ 1006 struct list_head leaf_cfs_rq_list; 1007 struct list_head *tmp_alone_branch; 1008 #endif /* CONFIG_FAIR_GROUP_SCHED */ 1009 1010 /* 1011 * This is part of a global counter where only the total sum 1012 * over all CPUs matters. A task can increase this counter on 1013 * one CPU and if it got migrated afterwards it may decrease 1014 * it on another CPU. Always updated under the runqueue lock: 1015 */ 1016 unsigned int nr_uninterruptible; 1017 1018 struct task_struct __rcu *curr; 1019 struct task_struct *idle; 1020 struct task_struct *stop; 1021 unsigned long next_balance; 1022 struct mm_struct *prev_mm; 1023 1024 unsigned int clock_update_flags; 1025 u64 clock; 1026 /* Ensure that all clocks are in the same cache line */ 1027 u64 clock_task ____cacheline_aligned; 1028 u64 clock_pelt; 1029 unsigned long lost_idle_time; 1030 u64 clock_pelt_idle; 1031 u64 clock_idle; 1032 #ifndef CONFIG_64BIT 1033 u64 clock_pelt_idle_copy; 1034 u64 clock_idle_copy; 1035 #endif 1036 1037 atomic_t nr_iowait; 1038 1039 #ifdef CONFIG_SCHED_DEBUG 1040 u64 last_seen_need_resched_ns; 1041 int ticks_without_resched; 1042 #endif 1043 1044 #ifdef CONFIG_MEMBARRIER 1045 int membarrier_state; 1046 #endif 1047 1048 #ifdef CONFIG_SMP 1049 struct root_domain *rd; 1050 struct sched_domain __rcu *sd; 1051 1052 unsigned long cpu_capacity; 1053 unsigned long cpu_capacity_orig; 1054 1055 struct balance_callback *balance_callback; 1056 1057 unsigned char nohz_idle_balance; 1058 unsigned char idle_balance; 1059 1060 unsigned long misfit_task_load; 1061 1062 /* For active balancing */ 1063 int active_balance; 1064 int push_cpu; 1065 struct cpu_stop_work active_balance_work; 1066 1067 /* CPU of this runqueue: */ 1068 int cpu; 1069 int online; 1070 1071 struct list_head cfs_tasks; 1072 1073 struct sched_avg avg_rt; 1074 struct sched_avg avg_dl; 1075 #ifdef CONFIG_HAVE_SCHED_AVG_IRQ 1076 struct sched_avg avg_irq; 1077 #endif 1078 #ifdef CONFIG_SCHED_THERMAL_PRESSURE 1079 struct sched_avg avg_thermal; 1080 #endif 1081 u64 idle_stamp; 1082 u64 avg_idle; 1083 1084 unsigned long wake_stamp; 1085 u64 wake_avg_idle; 1086 1087 /* This is used to determine avg_idle's max value */ 1088 u64 max_idle_balance_cost; 1089 1090 #ifdef CONFIG_HOTPLUG_CPU 1091 struct rcuwait hotplug_wait; 1092 #endif 1093 #endif /* CONFIG_SMP */ 1094 1095 #ifdef CONFIG_IRQ_TIME_ACCOUNTING 1096 u64 prev_irq_time; 1097 #endif 1098 #ifdef CONFIG_PARAVIRT 1099 u64 prev_steal_time; 1100 #endif 1101 #ifdef CONFIG_PARAVIRT_TIME_ACCOUNTING 1102 u64 prev_steal_time_rq; 1103 #endif 1104 1105 /* calc_load related fields */ 1106 unsigned long calc_load_update; 1107 long calc_load_active; 1108 1109 #ifdef CONFIG_SCHED_HRTICK 1110 #ifdef CONFIG_SMP 1111 call_single_data_t hrtick_csd; 1112 #endif 1113 struct hrtimer hrtick_timer; 1114 ktime_t hrtick_time; 1115 #endif 1116 1117 #ifdef CONFIG_SCHEDSTATS 1118 /* latency stats */ 1119 struct sched_info rq_sched_info; 1120 unsigned long long rq_cpu_time; 1121 /* could above be rq->cfs_rq.exec_clock + rq->rt_rq.rt_runtime ? */ 1122 1123 /* sys_sched_yield() stats */ 1124 unsigned int yld_count; 1125 1126 /* schedule() stats */ 1127 unsigned int sched_count; 1128 unsigned int sched_goidle; 1129 1130 /* try_to_wake_up() stats */ 1131 unsigned int ttwu_count; 1132 unsigned int ttwu_local; 1133 #endif 1134 1135 #ifdef CONFIG_CPU_IDLE 1136 /* Must be inspected within a rcu lock section */ 1137 struct cpuidle_state *idle_state; 1138 #endif 1139 1140 #ifdef CONFIG_SMP 1141 unsigned int nr_pinned; 1142 #endif 1143 unsigned int push_busy; 1144 struct cpu_stop_work push_work; 1145 1146 #ifdef CONFIG_SCHED_CORE 1147 /* per rq */ 1148 struct rq *core; 1149 struct task_struct *core_pick; 1150 unsigned int core_enabled; 1151 unsigned int core_sched_seq; 1152 struct rb_root core_tree; 1153 1154 /* shared state -- careful with sched_core_cpu_deactivate() */ 1155 unsigned int core_task_seq; 1156 unsigned int core_pick_seq; 1157 unsigned long core_cookie; 1158 unsigned int core_forceidle_count; 1159 unsigned int core_forceidle_seq; 1160 unsigned int core_forceidle_occupation; 1161 u64 core_forceidle_start; 1162 #endif 1163 1164 /* Scratch cpumask to be temporarily used under rq_lock */ 1165 cpumask_var_t scratch_mask; 1166 1167 #if defined(CONFIG_CFS_BANDWIDTH) && defined(CONFIG_SMP) 1168 call_single_data_t cfsb_csd; 1169 struct list_head cfsb_csd_list; 1170 #endif 1171 }; 1172 1173 #ifdef CONFIG_FAIR_GROUP_SCHED 1174 1175 /* CPU runqueue to which this cfs_rq is attached */ 1176 static inline struct rq *rq_of(struct cfs_rq *cfs_rq) 1177 { 1178 return cfs_rq->rq; 1179 } 1180 1181 #else 1182 1183 static inline struct rq *rq_of(struct cfs_rq *cfs_rq) 1184 { 1185 return container_of(cfs_rq, struct rq, cfs); 1186 } 1187 #endif 1188 1189 static inline int cpu_of(struct rq *rq) 1190 { 1191 #ifdef CONFIG_SMP 1192 return rq->cpu; 1193 #else 1194 return 0; 1195 #endif 1196 } 1197 1198 #define MDF_PUSH 0x01 1199 1200 static inline bool is_migration_disabled(struct task_struct *p) 1201 { 1202 #ifdef CONFIG_SMP 1203 return p->migration_disabled; 1204 #else 1205 return false; 1206 #endif 1207 } 1208 1209 DECLARE_PER_CPU_SHARED_ALIGNED(struct rq, runqueues); 1210 1211 #define cpu_rq(cpu) (&per_cpu(runqueues, (cpu))) 1212 #define this_rq() this_cpu_ptr(&runqueues) 1213 #define task_rq(p) cpu_rq(task_cpu(p)) 1214 #define cpu_curr(cpu) (cpu_rq(cpu)->curr) 1215 #define raw_rq() raw_cpu_ptr(&runqueues) 1216 1217 struct sched_group; 1218 #ifdef CONFIG_SCHED_CORE 1219 static inline struct cpumask *sched_group_span(struct sched_group *sg); 1220 1221 DECLARE_STATIC_KEY_FALSE(__sched_core_enabled); 1222 1223 static inline bool sched_core_enabled(struct rq *rq) 1224 { 1225 return static_branch_unlikely(&__sched_core_enabled) && rq->core_enabled; 1226 } 1227 1228 static inline bool sched_core_disabled(void) 1229 { 1230 return !static_branch_unlikely(&__sched_core_enabled); 1231 } 1232 1233 /* 1234 * Be careful with this function; not for general use. The return value isn't 1235 * stable unless you actually hold a relevant rq->__lock. 1236 */ 1237 static inline raw_spinlock_t *rq_lockp(struct rq *rq) 1238 { 1239 if (sched_core_enabled(rq)) 1240 return &rq->core->__lock; 1241 1242 return &rq->__lock; 1243 } 1244 1245 static inline raw_spinlock_t *__rq_lockp(struct rq *rq) 1246 { 1247 if (rq->core_enabled) 1248 return &rq->core->__lock; 1249 1250 return &rq->__lock; 1251 } 1252 1253 bool cfs_prio_less(const struct task_struct *a, const struct task_struct *b, 1254 bool fi); 1255 void task_vruntime_update(struct rq *rq, struct task_struct *p, bool in_fi); 1256 1257 /* 1258 * Helpers to check if the CPU's core cookie matches with the task's cookie 1259 * when core scheduling is enabled. 1260 * A special case is that the task's cookie always matches with CPU's core 1261 * cookie if the CPU is in an idle core. 1262 */ 1263 static inline bool sched_cpu_cookie_match(struct rq *rq, struct task_struct *p) 1264 { 1265 /* Ignore cookie match if core scheduler is not enabled on the CPU. */ 1266 if (!sched_core_enabled(rq)) 1267 return true; 1268 1269 return rq->core->core_cookie == p->core_cookie; 1270 } 1271 1272 static inline bool sched_core_cookie_match(struct rq *rq, struct task_struct *p) 1273 { 1274 bool idle_core = true; 1275 int cpu; 1276 1277 /* Ignore cookie match if core scheduler is not enabled on the CPU. */ 1278 if (!sched_core_enabled(rq)) 1279 return true; 1280 1281 for_each_cpu(cpu, cpu_smt_mask(cpu_of(rq))) { 1282 if (!available_idle_cpu(cpu)) { 1283 idle_core = false; 1284 break; 1285 } 1286 } 1287 1288 /* 1289 * A CPU in an idle core is always the best choice for tasks with 1290 * cookies. 1291 */ 1292 return idle_core || rq->core->core_cookie == p->core_cookie; 1293 } 1294 1295 static inline bool sched_group_cookie_match(struct rq *rq, 1296 struct task_struct *p, 1297 struct sched_group *group) 1298 { 1299 int cpu; 1300 1301 /* Ignore cookie match if core scheduler is not enabled on the CPU. */ 1302 if (!sched_core_enabled(rq)) 1303 return true; 1304 1305 for_each_cpu_and(cpu, sched_group_span(group), p->cpus_ptr) { 1306 if (sched_core_cookie_match(cpu_rq(cpu), p)) 1307 return true; 1308 } 1309 return false; 1310 } 1311 1312 static inline bool sched_core_enqueued(struct task_struct *p) 1313 { 1314 return !RB_EMPTY_NODE(&p->core_node); 1315 } 1316 1317 extern void sched_core_enqueue(struct rq *rq, struct task_struct *p); 1318 extern void sched_core_dequeue(struct rq *rq, struct task_struct *p, int flags); 1319 1320 extern void sched_core_get(void); 1321 extern void sched_core_put(void); 1322 1323 #else /* !CONFIG_SCHED_CORE */ 1324 1325 static inline bool sched_core_enabled(struct rq *rq) 1326 { 1327 return false; 1328 } 1329 1330 static inline bool sched_core_disabled(void) 1331 { 1332 return true; 1333 } 1334 1335 static inline raw_spinlock_t *rq_lockp(struct rq *rq) 1336 { 1337 return &rq->__lock; 1338 } 1339 1340 static inline raw_spinlock_t *__rq_lockp(struct rq *rq) 1341 { 1342 return &rq->__lock; 1343 } 1344 1345 static inline bool sched_cpu_cookie_match(struct rq *rq, struct task_struct *p) 1346 { 1347 return true; 1348 } 1349 1350 static inline bool sched_core_cookie_match(struct rq *rq, struct task_struct *p) 1351 { 1352 return true; 1353 } 1354 1355 static inline bool sched_group_cookie_match(struct rq *rq, 1356 struct task_struct *p, 1357 struct sched_group *group) 1358 { 1359 return true; 1360 } 1361 #endif /* CONFIG_SCHED_CORE */ 1362 1363 static inline void lockdep_assert_rq_held(struct rq *rq) 1364 { 1365 lockdep_assert_held(__rq_lockp(rq)); 1366 } 1367 1368 extern void raw_spin_rq_lock_nested(struct rq *rq, int subclass); 1369 extern bool raw_spin_rq_trylock(struct rq *rq); 1370 extern void raw_spin_rq_unlock(struct rq *rq); 1371 1372 static inline void raw_spin_rq_lock(struct rq *rq) 1373 { 1374 raw_spin_rq_lock_nested(rq, 0); 1375 } 1376 1377 static inline void raw_spin_rq_lock_irq(struct rq *rq) 1378 { 1379 local_irq_disable(); 1380 raw_spin_rq_lock(rq); 1381 } 1382 1383 static inline void raw_spin_rq_unlock_irq(struct rq *rq) 1384 { 1385 raw_spin_rq_unlock(rq); 1386 local_irq_enable(); 1387 } 1388 1389 static inline unsigned long _raw_spin_rq_lock_irqsave(struct rq *rq) 1390 { 1391 unsigned long flags; 1392 local_irq_save(flags); 1393 raw_spin_rq_lock(rq); 1394 return flags; 1395 } 1396 1397 static inline void raw_spin_rq_unlock_irqrestore(struct rq *rq, unsigned long flags) 1398 { 1399 raw_spin_rq_unlock(rq); 1400 local_irq_restore(flags); 1401 } 1402 1403 #define raw_spin_rq_lock_irqsave(rq, flags) \ 1404 do { \ 1405 flags = _raw_spin_rq_lock_irqsave(rq); \ 1406 } while (0) 1407 1408 #ifdef CONFIG_SCHED_SMT 1409 extern void __update_idle_core(struct rq *rq); 1410 1411 static inline void update_idle_core(struct rq *rq) 1412 { 1413 if (static_branch_unlikely(&sched_smt_present)) 1414 __update_idle_core(rq); 1415 } 1416 1417 #else 1418 static inline void update_idle_core(struct rq *rq) { } 1419 #endif 1420 1421 #ifdef CONFIG_FAIR_GROUP_SCHED 1422 static inline struct task_struct *task_of(struct sched_entity *se) 1423 { 1424 SCHED_WARN_ON(!entity_is_task(se)); 1425 return container_of(se, struct task_struct, se); 1426 } 1427 1428 static inline struct cfs_rq *task_cfs_rq(struct task_struct *p) 1429 { 1430 return p->se.cfs_rq; 1431 } 1432 1433 /* runqueue on which this entity is (to be) queued */ 1434 static inline struct cfs_rq *cfs_rq_of(const struct sched_entity *se) 1435 { 1436 return se->cfs_rq; 1437 } 1438 1439 /* runqueue "owned" by this group */ 1440 static inline struct cfs_rq *group_cfs_rq(struct sched_entity *grp) 1441 { 1442 return grp->my_q; 1443 } 1444 1445 #else 1446 1447 #define task_of(_se) container_of(_se, struct task_struct, se) 1448 1449 static inline struct cfs_rq *task_cfs_rq(const struct task_struct *p) 1450 { 1451 return &task_rq(p)->cfs; 1452 } 1453 1454 static inline struct cfs_rq *cfs_rq_of(const struct sched_entity *se) 1455 { 1456 const struct task_struct *p = task_of(se); 1457 struct rq *rq = task_rq(p); 1458 1459 return &rq->cfs; 1460 } 1461 1462 /* runqueue "owned" by this group */ 1463 static inline struct cfs_rq *group_cfs_rq(struct sched_entity *grp) 1464 { 1465 return NULL; 1466 } 1467 #endif 1468 1469 extern void update_rq_clock(struct rq *rq); 1470 1471 /* 1472 * rq::clock_update_flags bits 1473 * 1474 * %RQCF_REQ_SKIP - will request skipping of clock update on the next 1475 * call to __schedule(). This is an optimisation to avoid 1476 * neighbouring rq clock updates. 1477 * 1478 * %RQCF_ACT_SKIP - is set from inside of __schedule() when skipping is 1479 * in effect and calls to update_rq_clock() are being ignored. 1480 * 1481 * %RQCF_UPDATED - is a debug flag that indicates whether a call has been 1482 * made to update_rq_clock() since the last time rq::lock was pinned. 1483 * 1484 * If inside of __schedule(), clock_update_flags will have been 1485 * shifted left (a left shift is a cheap operation for the fast path 1486 * to promote %RQCF_REQ_SKIP to %RQCF_ACT_SKIP), so you must use, 1487 * 1488 * if (rq-clock_update_flags >= RQCF_UPDATED) 1489 * 1490 * to check if %RQCF_UPDATED is set. It'll never be shifted more than 1491 * one position though, because the next rq_unpin_lock() will shift it 1492 * back. 1493 */ 1494 #define RQCF_REQ_SKIP 0x01 1495 #define RQCF_ACT_SKIP 0x02 1496 #define RQCF_UPDATED 0x04 1497 1498 static inline void assert_clock_updated(struct rq *rq) 1499 { 1500 /* 1501 * The only reason for not seeing a clock update since the 1502 * last rq_pin_lock() is if we're currently skipping updates. 1503 */ 1504 SCHED_WARN_ON(rq->clock_update_flags < RQCF_ACT_SKIP); 1505 } 1506 1507 static inline u64 rq_clock(struct rq *rq) 1508 { 1509 lockdep_assert_rq_held(rq); 1510 assert_clock_updated(rq); 1511 1512 return rq->clock; 1513 } 1514 1515 static inline u64 rq_clock_task(struct rq *rq) 1516 { 1517 lockdep_assert_rq_held(rq); 1518 assert_clock_updated(rq); 1519 1520 return rq->clock_task; 1521 } 1522 1523 /** 1524 * By default the decay is the default pelt decay period. 1525 * The decay shift can change the decay period in 1526 * multiples of 32. 1527 * Decay shift Decay period(ms) 1528 * 0 32 1529 * 1 64 1530 * 2 128 1531 * 3 256 1532 * 4 512 1533 */ 1534 extern int sched_thermal_decay_shift; 1535 1536 static inline u64 rq_clock_thermal(struct rq *rq) 1537 { 1538 return rq_clock_task(rq) >> sched_thermal_decay_shift; 1539 } 1540 1541 static inline void rq_clock_skip_update(struct rq *rq) 1542 { 1543 lockdep_assert_rq_held(rq); 1544 rq->clock_update_flags |= RQCF_REQ_SKIP; 1545 } 1546 1547 /* 1548 * See rt task throttling, which is the only time a skip 1549 * request is canceled. 1550 */ 1551 static inline void rq_clock_cancel_skipupdate(struct rq *rq) 1552 { 1553 lockdep_assert_rq_held(rq); 1554 rq->clock_update_flags &= ~RQCF_REQ_SKIP; 1555 } 1556 1557 /* 1558 * During cpu offlining and rq wide unthrottling, we can trigger 1559 * an update_rq_clock() for several cfs and rt runqueues (Typically 1560 * when using list_for_each_entry_*) 1561 * rq_clock_start_loop_update() can be called after updating the clock 1562 * once and before iterating over the list to prevent multiple update. 1563 * After the iterative traversal, we need to call rq_clock_stop_loop_update() 1564 * to clear RQCF_ACT_SKIP of rq->clock_update_flags. 1565 */ 1566 static inline void rq_clock_start_loop_update(struct rq *rq) 1567 { 1568 lockdep_assert_rq_held(rq); 1569 SCHED_WARN_ON(rq->clock_update_flags & RQCF_ACT_SKIP); 1570 rq->clock_update_flags |= RQCF_ACT_SKIP; 1571 } 1572 1573 static inline void rq_clock_stop_loop_update(struct rq *rq) 1574 { 1575 lockdep_assert_rq_held(rq); 1576 rq->clock_update_flags &= ~RQCF_ACT_SKIP; 1577 } 1578 1579 struct rq_flags { 1580 unsigned long flags; 1581 struct pin_cookie cookie; 1582 #ifdef CONFIG_SCHED_DEBUG 1583 /* 1584 * A copy of (rq::clock_update_flags & RQCF_UPDATED) for the 1585 * current pin context is stashed here in case it needs to be 1586 * restored in rq_repin_lock(). 1587 */ 1588 unsigned int clock_update_flags; 1589 #endif 1590 }; 1591 1592 extern struct balance_callback balance_push_callback; 1593 1594 /* 1595 * Lockdep annotation that avoids accidental unlocks; it's like a 1596 * sticky/continuous lockdep_assert_held(). 1597 * 1598 * This avoids code that has access to 'struct rq *rq' (basically everything in 1599 * the scheduler) from accidentally unlocking the rq if they do not also have a 1600 * copy of the (on-stack) 'struct rq_flags rf'. 1601 * 1602 * Also see Documentation/locking/lockdep-design.rst. 1603 */ 1604 static inline void rq_pin_lock(struct rq *rq, struct rq_flags *rf) 1605 { 1606 rf->cookie = lockdep_pin_lock(__rq_lockp(rq)); 1607 1608 #ifdef CONFIG_SCHED_DEBUG 1609 rq->clock_update_flags &= (RQCF_REQ_SKIP|RQCF_ACT_SKIP); 1610 rf->clock_update_flags = 0; 1611 #ifdef CONFIG_SMP 1612 SCHED_WARN_ON(rq->balance_callback && rq->balance_callback != &balance_push_callback); 1613 #endif 1614 #endif 1615 } 1616 1617 static inline void rq_unpin_lock(struct rq *rq, struct rq_flags *rf) 1618 { 1619 #ifdef CONFIG_SCHED_DEBUG 1620 if (rq->clock_update_flags > RQCF_ACT_SKIP) 1621 rf->clock_update_flags = RQCF_UPDATED; 1622 #endif 1623 1624 lockdep_unpin_lock(__rq_lockp(rq), rf->cookie); 1625 } 1626 1627 static inline void rq_repin_lock(struct rq *rq, struct rq_flags *rf) 1628 { 1629 lockdep_repin_lock(__rq_lockp(rq), rf->cookie); 1630 1631 #ifdef CONFIG_SCHED_DEBUG 1632 /* 1633 * Restore the value we stashed in @rf for this pin context. 1634 */ 1635 rq->clock_update_flags |= rf->clock_update_flags; 1636 #endif 1637 } 1638 1639 struct rq *__task_rq_lock(struct task_struct *p, struct rq_flags *rf) 1640 __acquires(rq->lock); 1641 1642 struct rq *task_rq_lock(struct task_struct *p, struct rq_flags *rf) 1643 __acquires(p->pi_lock) 1644 __acquires(rq->lock); 1645 1646 static inline void __task_rq_unlock(struct rq *rq, struct rq_flags *rf) 1647 __releases(rq->lock) 1648 { 1649 rq_unpin_lock(rq, rf); 1650 raw_spin_rq_unlock(rq); 1651 } 1652 1653 static inline void 1654 task_rq_unlock(struct rq *rq, struct task_struct *p, struct rq_flags *rf) 1655 __releases(rq->lock) 1656 __releases(p->pi_lock) 1657 { 1658 rq_unpin_lock(rq, rf); 1659 raw_spin_rq_unlock(rq); 1660 raw_spin_unlock_irqrestore(&p->pi_lock, rf->flags); 1661 } 1662 1663 static inline void 1664 rq_lock_irqsave(struct rq *rq, struct rq_flags *rf) 1665 __acquires(rq->lock) 1666 { 1667 raw_spin_rq_lock_irqsave(rq, rf->flags); 1668 rq_pin_lock(rq, rf); 1669 } 1670 1671 static inline void 1672 rq_lock_irq(struct rq *rq, struct rq_flags *rf) 1673 __acquires(rq->lock) 1674 { 1675 raw_spin_rq_lock_irq(rq); 1676 rq_pin_lock(rq, rf); 1677 } 1678 1679 static inline void 1680 rq_lock(struct rq *rq, struct rq_flags *rf) 1681 __acquires(rq->lock) 1682 { 1683 raw_spin_rq_lock(rq); 1684 rq_pin_lock(rq, rf); 1685 } 1686 1687 static inline void 1688 rq_unlock_irqrestore(struct rq *rq, struct rq_flags *rf) 1689 __releases(rq->lock) 1690 { 1691 rq_unpin_lock(rq, rf); 1692 raw_spin_rq_unlock_irqrestore(rq, rf->flags); 1693 } 1694 1695 static inline void 1696 rq_unlock_irq(struct rq *rq, struct rq_flags *rf) 1697 __releases(rq->lock) 1698 { 1699 rq_unpin_lock(rq, rf); 1700 raw_spin_rq_unlock_irq(rq); 1701 } 1702 1703 static inline void 1704 rq_unlock(struct rq *rq, struct rq_flags *rf) 1705 __releases(rq->lock) 1706 { 1707 rq_unpin_lock(rq, rf); 1708 raw_spin_rq_unlock(rq); 1709 } 1710 1711 DEFINE_LOCK_GUARD_1(rq_lock, struct rq, 1712 rq_lock(_T->lock, &_T->rf), 1713 rq_unlock(_T->lock, &_T->rf), 1714 struct rq_flags rf) 1715 1716 DEFINE_LOCK_GUARD_1(rq_lock_irq, struct rq, 1717 rq_lock_irq(_T->lock, &_T->rf), 1718 rq_unlock_irq(_T->lock, &_T->rf), 1719 struct rq_flags rf) 1720 1721 DEFINE_LOCK_GUARD_1(rq_lock_irqsave, struct rq, 1722 rq_lock_irqsave(_T->lock, &_T->rf), 1723 rq_unlock_irqrestore(_T->lock, &_T->rf), 1724 struct rq_flags rf) 1725 1726 static inline struct rq * 1727 this_rq_lock_irq(struct rq_flags *rf) 1728 __acquires(rq->lock) 1729 { 1730 struct rq *rq; 1731 1732 local_irq_disable(); 1733 rq = this_rq(); 1734 rq_lock(rq, rf); 1735 return rq; 1736 } 1737 1738 #ifdef CONFIG_NUMA 1739 enum numa_topology_type { 1740 NUMA_DIRECT, 1741 NUMA_GLUELESS_MESH, 1742 NUMA_BACKPLANE, 1743 }; 1744 extern enum numa_topology_type sched_numa_topology_type; 1745 extern int sched_max_numa_distance; 1746 extern bool find_numa_distance(int distance); 1747 extern void sched_init_numa(int offline_node); 1748 extern void sched_update_numa(int cpu, bool online); 1749 extern void sched_domains_numa_masks_set(unsigned int cpu); 1750 extern void sched_domains_numa_masks_clear(unsigned int cpu); 1751 extern int sched_numa_find_closest(const struct cpumask *cpus, int cpu); 1752 #else 1753 static inline void sched_init_numa(int offline_node) { } 1754 static inline void sched_update_numa(int cpu, bool online) { } 1755 static inline void sched_domains_numa_masks_set(unsigned int cpu) { } 1756 static inline void sched_domains_numa_masks_clear(unsigned int cpu) { } 1757 static inline int sched_numa_find_closest(const struct cpumask *cpus, int cpu) 1758 { 1759 return nr_cpu_ids; 1760 } 1761 #endif 1762 1763 #ifdef CONFIG_NUMA_BALANCING 1764 /* The regions in numa_faults array from task_struct */ 1765 enum numa_faults_stats { 1766 NUMA_MEM = 0, 1767 NUMA_CPU, 1768 NUMA_MEMBUF, 1769 NUMA_CPUBUF 1770 }; 1771 extern void sched_setnuma(struct task_struct *p, int node); 1772 extern int migrate_task_to(struct task_struct *p, int cpu); 1773 extern int migrate_swap(struct task_struct *p, struct task_struct *t, 1774 int cpu, int scpu); 1775 extern void init_numa_balancing(unsigned long clone_flags, struct task_struct *p); 1776 #else 1777 static inline void 1778 init_numa_balancing(unsigned long clone_flags, struct task_struct *p) 1779 { 1780 } 1781 #endif /* CONFIG_NUMA_BALANCING */ 1782 1783 #ifdef CONFIG_SMP 1784 1785 static inline void 1786 queue_balance_callback(struct rq *rq, 1787 struct balance_callback *head, 1788 void (*func)(struct rq *rq)) 1789 { 1790 lockdep_assert_rq_held(rq); 1791 1792 /* 1793 * Don't (re)queue an already queued item; nor queue anything when 1794 * balance_push() is active, see the comment with 1795 * balance_push_callback. 1796 */ 1797 if (unlikely(head->next || rq->balance_callback == &balance_push_callback)) 1798 return; 1799 1800 head->func = func; 1801 head->next = rq->balance_callback; 1802 rq->balance_callback = head; 1803 } 1804 1805 #define rcu_dereference_check_sched_domain(p) \ 1806 rcu_dereference_check((p), \ 1807 lockdep_is_held(&sched_domains_mutex)) 1808 1809 /* 1810 * The domain tree (rq->sd) is protected by RCU's quiescent state transition. 1811 * See destroy_sched_domains: call_rcu for details. 1812 * 1813 * The domain tree of any CPU may only be accessed from within 1814 * preempt-disabled sections. 1815 */ 1816 #define for_each_domain(cpu, __sd) \ 1817 for (__sd = rcu_dereference_check_sched_domain(cpu_rq(cpu)->sd); \ 1818 __sd; __sd = __sd->parent) 1819 1820 /* A mask of all the SD flags that have the SDF_SHARED_CHILD metaflag */ 1821 #define SD_FLAG(name, mflags) (name * !!((mflags) & SDF_SHARED_CHILD)) | 1822 static const unsigned int SD_SHARED_CHILD_MASK = 1823 #include <linux/sched/sd_flags.h> 1824 0; 1825 #undef SD_FLAG 1826 1827 /** 1828 * highest_flag_domain - Return highest sched_domain containing flag. 1829 * @cpu: The CPU whose highest level of sched domain is to 1830 * be returned. 1831 * @flag: The flag to check for the highest sched_domain 1832 * for the given CPU. 1833 * 1834 * Returns the highest sched_domain of a CPU which contains @flag. If @flag has 1835 * the SDF_SHARED_CHILD metaflag, all the children domains also have @flag. 1836 */ 1837 static inline struct sched_domain *highest_flag_domain(int cpu, int flag) 1838 { 1839 struct sched_domain *sd, *hsd = NULL; 1840 1841 for_each_domain(cpu, sd) { 1842 if (sd->flags & flag) { 1843 hsd = sd; 1844 continue; 1845 } 1846 1847 /* 1848 * Stop the search if @flag is known to be shared at lower 1849 * levels. It will not be found further up. 1850 */ 1851 if (flag & SD_SHARED_CHILD_MASK) 1852 break; 1853 } 1854 1855 return hsd; 1856 } 1857 1858 static inline struct sched_domain *lowest_flag_domain(int cpu, int flag) 1859 { 1860 struct sched_domain *sd; 1861 1862 for_each_domain(cpu, sd) { 1863 if (sd->flags & flag) 1864 break; 1865 } 1866 1867 return sd; 1868 } 1869 1870 DECLARE_PER_CPU(struct sched_domain __rcu *, sd_llc); 1871 DECLARE_PER_CPU(int, sd_llc_size); 1872 DECLARE_PER_CPU(int, sd_llc_id); 1873 DECLARE_PER_CPU(struct sched_domain_shared __rcu *, sd_llc_shared); 1874 DECLARE_PER_CPU(struct sched_domain __rcu *, sd_numa); 1875 DECLARE_PER_CPU(struct sched_domain __rcu *, sd_asym_packing); 1876 DECLARE_PER_CPU(struct sched_domain __rcu *, sd_asym_cpucapacity); 1877 extern struct static_key_false sched_asym_cpucapacity; 1878 1879 static __always_inline bool sched_asym_cpucap_active(void) 1880 { 1881 return static_branch_unlikely(&sched_asym_cpucapacity); 1882 } 1883 1884 struct sched_group_capacity { 1885 atomic_t ref; 1886 /* 1887 * CPU capacity of this group, SCHED_CAPACITY_SCALE being max capacity 1888 * for a single CPU. 1889 */ 1890 unsigned long capacity; 1891 unsigned long min_capacity; /* Min per-CPU capacity in group */ 1892 unsigned long max_capacity; /* Max per-CPU capacity in group */ 1893 unsigned long next_update; 1894 int imbalance; /* XXX unrelated to capacity but shared group state */ 1895 1896 #ifdef CONFIG_SCHED_DEBUG 1897 int id; 1898 #endif 1899 1900 unsigned long cpumask[]; /* Balance mask */ 1901 }; 1902 1903 struct sched_group { 1904 struct sched_group *next; /* Must be a circular list */ 1905 atomic_t ref; 1906 1907 unsigned int group_weight; 1908 unsigned int cores; 1909 struct sched_group_capacity *sgc; 1910 int asym_prefer_cpu; /* CPU of highest priority in group */ 1911 int flags; 1912 1913 /* 1914 * The CPUs this group covers. 1915 * 1916 * NOTE: this field is variable length. (Allocated dynamically 1917 * by attaching extra space to the end of the structure, 1918 * depending on how many CPUs the kernel has booted up with) 1919 */ 1920 unsigned long cpumask[]; 1921 }; 1922 1923 static inline struct cpumask *sched_group_span(struct sched_group *sg) 1924 { 1925 return to_cpumask(sg->cpumask); 1926 } 1927 1928 /* 1929 * See build_balance_mask(). 1930 */ 1931 static inline struct cpumask *group_balance_mask(struct sched_group *sg) 1932 { 1933 return to_cpumask(sg->sgc->cpumask); 1934 } 1935 1936 extern int group_balance_cpu(struct sched_group *sg); 1937 1938 #ifdef CONFIG_SCHED_DEBUG 1939 void update_sched_domain_debugfs(void); 1940 void dirty_sched_domain_sysctl(int cpu); 1941 #else 1942 static inline void update_sched_domain_debugfs(void) 1943 { 1944 } 1945 static inline void dirty_sched_domain_sysctl(int cpu) 1946 { 1947 } 1948 #endif 1949 1950 extern int sched_update_scaling(void); 1951 1952 static inline const struct cpumask *task_user_cpus(struct task_struct *p) 1953 { 1954 if (!p->user_cpus_ptr) 1955 return cpu_possible_mask; /* &init_task.cpus_mask */ 1956 return p->user_cpus_ptr; 1957 } 1958 #endif /* CONFIG_SMP */ 1959 1960 #include "stats.h" 1961 1962 #if defined(CONFIG_SCHED_CORE) && defined(CONFIG_SCHEDSTATS) 1963 1964 extern void __sched_core_account_forceidle(struct rq *rq); 1965 1966 static inline void sched_core_account_forceidle(struct rq *rq) 1967 { 1968 if (schedstat_enabled()) 1969 __sched_core_account_forceidle(rq); 1970 } 1971 1972 extern void __sched_core_tick(struct rq *rq); 1973 1974 static inline void sched_core_tick(struct rq *rq) 1975 { 1976 if (sched_core_enabled(rq) && schedstat_enabled()) 1977 __sched_core_tick(rq); 1978 } 1979 1980 #else 1981 1982 static inline void sched_core_account_forceidle(struct rq *rq) {} 1983 1984 static inline void sched_core_tick(struct rq *rq) {} 1985 1986 #endif /* CONFIG_SCHED_CORE && CONFIG_SCHEDSTATS */ 1987 1988 #ifdef CONFIG_CGROUP_SCHED 1989 1990 /* 1991 * Return the group to which this tasks belongs. 1992 * 1993 * We cannot use task_css() and friends because the cgroup subsystem 1994 * changes that value before the cgroup_subsys::attach() method is called, 1995 * therefore we cannot pin it and might observe the wrong value. 1996 * 1997 * The same is true for autogroup's p->signal->autogroup->tg, the autogroup 1998 * core changes this before calling sched_move_task(). 1999 * 2000 * Instead we use a 'copy' which is updated from sched_move_task() while 2001 * holding both task_struct::pi_lock and rq::lock. 2002 */ 2003 static inline struct task_group *task_group(struct task_struct *p) 2004 { 2005 return p->sched_task_group; 2006 } 2007 2008 /* Change a task's cfs_rq and parent entity if it moves across CPUs/groups */ 2009 static inline void set_task_rq(struct task_struct *p, unsigned int cpu) 2010 { 2011 #if defined(CONFIG_FAIR_GROUP_SCHED) || defined(CONFIG_RT_GROUP_SCHED) 2012 struct task_group *tg = task_group(p); 2013 #endif 2014 2015 #ifdef CONFIG_FAIR_GROUP_SCHED 2016 set_task_rq_fair(&p->se, p->se.cfs_rq, tg->cfs_rq[cpu]); 2017 p->se.cfs_rq = tg->cfs_rq[cpu]; 2018 p->se.parent = tg->se[cpu]; 2019 p->se.depth = tg->se[cpu] ? tg->se[cpu]->depth + 1 : 0; 2020 #endif 2021 2022 #ifdef CONFIG_RT_GROUP_SCHED 2023 p->rt.rt_rq = tg->rt_rq[cpu]; 2024 p->rt.parent = tg->rt_se[cpu]; 2025 #endif 2026 } 2027 2028 #else /* CONFIG_CGROUP_SCHED */ 2029 2030 static inline void set_task_rq(struct task_struct *p, unsigned int cpu) { } 2031 static inline struct task_group *task_group(struct task_struct *p) 2032 { 2033 return NULL; 2034 } 2035 2036 #endif /* CONFIG_CGROUP_SCHED */ 2037 2038 static inline void __set_task_cpu(struct task_struct *p, unsigned int cpu) 2039 { 2040 set_task_rq(p, cpu); 2041 #ifdef CONFIG_SMP 2042 /* 2043 * After ->cpu is set up to a new value, task_rq_lock(p, ...) can be 2044 * successfully executed on another CPU. We must ensure that updates of 2045 * per-task data have been completed by this moment. 2046 */ 2047 smp_wmb(); 2048 WRITE_ONCE(task_thread_info(p)->cpu, cpu); 2049 p->wake_cpu = cpu; 2050 #endif 2051 } 2052 2053 /* 2054 * Tunables that become constants when CONFIG_SCHED_DEBUG is off: 2055 */ 2056 #ifdef CONFIG_SCHED_DEBUG 2057 # define const_debug __read_mostly 2058 #else 2059 # define const_debug const 2060 #endif 2061 2062 #define SCHED_FEAT(name, enabled) \ 2063 __SCHED_FEAT_##name , 2064 2065 enum { 2066 #include "features.h" 2067 __SCHED_FEAT_NR, 2068 }; 2069 2070 #undef SCHED_FEAT 2071 2072 #ifdef CONFIG_SCHED_DEBUG 2073 2074 /* 2075 * To support run-time toggling of sched features, all the translation units 2076 * (but core.c) reference the sysctl_sched_features defined in core.c. 2077 */ 2078 extern const_debug unsigned int sysctl_sched_features; 2079 2080 #ifdef CONFIG_JUMP_LABEL 2081 #define SCHED_FEAT(name, enabled) \ 2082 static __always_inline bool static_branch_##name(struct static_key *key) \ 2083 { \ 2084 return static_key_##enabled(key); \ 2085 } 2086 2087 #include "features.h" 2088 #undef SCHED_FEAT 2089 2090 extern struct static_key sched_feat_keys[__SCHED_FEAT_NR]; 2091 #define sched_feat(x) (static_branch_##x(&sched_feat_keys[__SCHED_FEAT_##x])) 2092 2093 #else /* !CONFIG_JUMP_LABEL */ 2094 2095 #define sched_feat(x) (sysctl_sched_features & (1UL << __SCHED_FEAT_##x)) 2096 2097 #endif /* CONFIG_JUMP_LABEL */ 2098 2099 #else /* !SCHED_DEBUG */ 2100 2101 /* 2102 * Each translation unit has its own copy of sysctl_sched_features to allow 2103 * constants propagation at compile time and compiler optimization based on 2104 * features default. 2105 */ 2106 #define SCHED_FEAT(name, enabled) \ 2107 (1UL << __SCHED_FEAT_##name) * enabled | 2108 static const_debug __maybe_unused unsigned int sysctl_sched_features = 2109 #include "features.h" 2110 0; 2111 #undef SCHED_FEAT 2112 2113 #define sched_feat(x) !!(sysctl_sched_features & (1UL << __SCHED_FEAT_##x)) 2114 2115 #endif /* SCHED_DEBUG */ 2116 2117 extern struct static_key_false sched_numa_balancing; 2118 extern struct static_key_false sched_schedstats; 2119 2120 static inline u64 global_rt_period(void) 2121 { 2122 return (u64)sysctl_sched_rt_period * NSEC_PER_USEC; 2123 } 2124 2125 static inline u64 global_rt_runtime(void) 2126 { 2127 if (sysctl_sched_rt_runtime < 0) 2128 return RUNTIME_INF; 2129 2130 return (u64)sysctl_sched_rt_runtime * NSEC_PER_USEC; 2131 } 2132 2133 static inline int task_current(struct rq *rq, struct task_struct *p) 2134 { 2135 return rq->curr == p; 2136 } 2137 2138 static inline int task_on_cpu(struct rq *rq, struct task_struct *p) 2139 { 2140 #ifdef CONFIG_SMP 2141 return p->on_cpu; 2142 #else 2143 return task_current(rq, p); 2144 #endif 2145 } 2146 2147 static inline int task_on_rq_queued(struct task_struct *p) 2148 { 2149 return p->on_rq == TASK_ON_RQ_QUEUED; 2150 } 2151 2152 static inline int task_on_rq_migrating(struct task_struct *p) 2153 { 2154 return READ_ONCE(p->on_rq) == TASK_ON_RQ_MIGRATING; 2155 } 2156 2157 /* Wake flags. The first three directly map to some SD flag value */ 2158 #define WF_EXEC 0x02 /* Wakeup after exec; maps to SD_BALANCE_EXEC */ 2159 #define WF_FORK 0x04 /* Wakeup after fork; maps to SD_BALANCE_FORK */ 2160 #define WF_TTWU 0x08 /* Wakeup; maps to SD_BALANCE_WAKE */ 2161 2162 #define WF_SYNC 0x10 /* Waker goes to sleep after wakeup */ 2163 #define WF_MIGRATED 0x20 /* Internal use, task got migrated */ 2164 #define WF_CURRENT_CPU 0x40 /* Prefer to move the wakee to the current CPU. */ 2165 2166 #ifdef CONFIG_SMP 2167 static_assert(WF_EXEC == SD_BALANCE_EXEC); 2168 static_assert(WF_FORK == SD_BALANCE_FORK); 2169 static_assert(WF_TTWU == SD_BALANCE_WAKE); 2170 #endif 2171 2172 /* 2173 * To aid in avoiding the subversion of "niceness" due to uneven distribution 2174 * of tasks with abnormal "nice" values across CPUs the contribution that 2175 * each task makes to its run queue's load is weighted according to its 2176 * scheduling class and "nice" value. For SCHED_NORMAL tasks this is just a 2177 * scaled version of the new time slice allocation that they receive on time 2178 * slice expiry etc. 2179 */ 2180 2181 #define WEIGHT_IDLEPRIO 3 2182 #define WMULT_IDLEPRIO 1431655765 2183 2184 extern const int sched_prio_to_weight[40]; 2185 extern const u32 sched_prio_to_wmult[40]; 2186 2187 /* 2188 * {de,en}queue flags: 2189 * 2190 * DEQUEUE_SLEEP - task is no longer runnable 2191 * ENQUEUE_WAKEUP - task just became runnable 2192 * 2193 * SAVE/RESTORE - an otherwise spurious dequeue/enqueue, done to ensure tasks 2194 * are in a known state which allows modification. Such pairs 2195 * should preserve as much state as possible. 2196 * 2197 * MOVE - paired with SAVE/RESTORE, explicitly does not preserve the location 2198 * in the runqueue. 2199 * 2200 * ENQUEUE_HEAD - place at front of runqueue (tail if not specified) 2201 * ENQUEUE_REPLENISH - CBS (replenish runtime and postpone deadline) 2202 * ENQUEUE_MIGRATED - the task was migrated during wakeup 2203 * 2204 */ 2205 2206 #define DEQUEUE_SLEEP 0x01 2207 #define DEQUEUE_SAVE 0x02 /* Matches ENQUEUE_RESTORE */ 2208 #define DEQUEUE_MOVE 0x04 /* Matches ENQUEUE_MOVE */ 2209 #define DEQUEUE_NOCLOCK 0x08 /* Matches ENQUEUE_NOCLOCK */ 2210 2211 #define ENQUEUE_WAKEUP 0x01 2212 #define ENQUEUE_RESTORE 0x02 2213 #define ENQUEUE_MOVE 0x04 2214 #define ENQUEUE_NOCLOCK 0x08 2215 2216 #define ENQUEUE_HEAD 0x10 2217 #define ENQUEUE_REPLENISH 0x20 2218 #ifdef CONFIG_SMP 2219 #define ENQUEUE_MIGRATED 0x40 2220 #else 2221 #define ENQUEUE_MIGRATED 0x00 2222 #endif 2223 #define ENQUEUE_INITIAL 0x80 2224 2225 #define RETRY_TASK ((void *)-1UL) 2226 2227 struct affinity_context { 2228 const struct cpumask *new_mask; 2229 struct cpumask *user_mask; 2230 unsigned int flags; 2231 }; 2232 2233 struct sched_class { 2234 2235 #ifdef CONFIG_UCLAMP_TASK 2236 int uclamp_enabled; 2237 #endif 2238 2239 void (*enqueue_task) (struct rq *rq, struct task_struct *p, int flags); 2240 void (*dequeue_task) (struct rq *rq, struct task_struct *p, int flags); 2241 void (*yield_task) (struct rq *rq); 2242 bool (*yield_to_task)(struct rq *rq, struct task_struct *p); 2243 2244 void (*check_preempt_curr)(struct rq *rq, struct task_struct *p, int flags); 2245 2246 struct task_struct *(*pick_next_task)(struct rq *rq); 2247 2248 void (*put_prev_task)(struct rq *rq, struct task_struct *p); 2249 void (*set_next_task)(struct rq *rq, struct task_struct *p, bool first); 2250 2251 #ifdef CONFIG_SMP 2252 int (*balance)(struct rq *rq, struct task_struct *prev, struct rq_flags *rf); 2253 int (*select_task_rq)(struct task_struct *p, int task_cpu, int flags); 2254 2255 struct task_struct * (*pick_task)(struct rq *rq); 2256 2257 void (*migrate_task_rq)(struct task_struct *p, int new_cpu); 2258 2259 void (*task_woken)(struct rq *this_rq, struct task_struct *task); 2260 2261 void (*set_cpus_allowed)(struct task_struct *p, struct affinity_context *ctx); 2262 2263 void (*rq_online)(struct rq *rq); 2264 void (*rq_offline)(struct rq *rq); 2265 2266 struct rq *(*find_lock_rq)(struct task_struct *p, struct rq *rq); 2267 #endif 2268 2269 void (*task_tick)(struct rq *rq, struct task_struct *p, int queued); 2270 void (*task_fork)(struct task_struct *p); 2271 void (*task_dead)(struct task_struct *p); 2272 2273 /* 2274 * The switched_from() call is allowed to drop rq->lock, therefore we 2275 * cannot assume the switched_from/switched_to pair is serialized by 2276 * rq->lock. They are however serialized by p->pi_lock. 2277 */ 2278 void (*switched_from)(struct rq *this_rq, struct task_struct *task); 2279 void (*switched_to) (struct rq *this_rq, struct task_struct *task); 2280 void (*prio_changed) (struct rq *this_rq, struct task_struct *task, 2281 int oldprio); 2282 2283 unsigned int (*get_rr_interval)(struct rq *rq, 2284 struct task_struct *task); 2285 2286 void (*update_curr)(struct rq *rq); 2287 2288 #ifdef CONFIG_FAIR_GROUP_SCHED 2289 void (*task_change_group)(struct task_struct *p); 2290 #endif 2291 2292 #ifdef CONFIG_SCHED_CORE 2293 int (*task_is_throttled)(struct task_struct *p, int cpu); 2294 #endif 2295 }; 2296 2297 static inline void put_prev_task(struct rq *rq, struct task_struct *prev) 2298 { 2299 WARN_ON_ONCE(rq->curr != prev); 2300 prev->sched_class->put_prev_task(rq, prev); 2301 } 2302 2303 static inline void set_next_task(struct rq *rq, struct task_struct *next) 2304 { 2305 next->sched_class->set_next_task(rq, next, false); 2306 } 2307 2308 2309 /* 2310 * Helper to define a sched_class instance; each one is placed in a separate 2311 * section which is ordered by the linker script: 2312 * 2313 * include/asm-generic/vmlinux.lds.h 2314 * 2315 * *CAREFUL* they are laid out in *REVERSE* order!!! 2316 * 2317 * Also enforce alignment on the instance, not the type, to guarantee layout. 2318 */ 2319 #define DEFINE_SCHED_CLASS(name) \ 2320 const struct sched_class name##_sched_class \ 2321 __aligned(__alignof__(struct sched_class)) \ 2322 __section("__" #name "_sched_class") 2323 2324 /* Defined in include/asm-generic/vmlinux.lds.h */ 2325 extern struct sched_class __sched_class_highest[]; 2326 extern struct sched_class __sched_class_lowest[]; 2327 2328 #define for_class_range(class, _from, _to) \ 2329 for (class = (_from); class < (_to); class++) 2330 2331 #define for_each_class(class) \ 2332 for_class_range(class, __sched_class_highest, __sched_class_lowest) 2333 2334 #define sched_class_above(_a, _b) ((_a) < (_b)) 2335 2336 extern const struct sched_class stop_sched_class; 2337 extern const struct sched_class dl_sched_class; 2338 extern const struct sched_class rt_sched_class; 2339 extern const struct sched_class fair_sched_class; 2340 extern const struct sched_class idle_sched_class; 2341 2342 static inline bool sched_stop_runnable(struct rq *rq) 2343 { 2344 return rq->stop && task_on_rq_queued(rq->stop); 2345 } 2346 2347 static inline bool sched_dl_runnable(struct rq *rq) 2348 { 2349 return rq->dl.dl_nr_running > 0; 2350 } 2351 2352 static inline bool sched_rt_runnable(struct rq *rq) 2353 { 2354 return rq->rt.rt_queued > 0; 2355 } 2356 2357 static inline bool sched_fair_runnable(struct rq *rq) 2358 { 2359 return rq->cfs.nr_running > 0; 2360 } 2361 2362 extern struct task_struct *pick_next_task_fair(struct rq *rq, struct task_struct *prev, struct rq_flags *rf); 2363 extern struct task_struct *pick_next_task_idle(struct rq *rq); 2364 2365 #define SCA_CHECK 0x01 2366 #define SCA_MIGRATE_DISABLE 0x02 2367 #define SCA_MIGRATE_ENABLE 0x04 2368 #define SCA_USER 0x08 2369 2370 #ifdef CONFIG_SMP 2371 2372 extern void update_group_capacity(struct sched_domain *sd, int cpu); 2373 2374 extern void trigger_load_balance(struct rq *rq); 2375 2376 extern void set_cpus_allowed_common(struct task_struct *p, struct affinity_context *ctx); 2377 2378 static inline struct task_struct *get_push_task(struct rq *rq) 2379 { 2380 struct task_struct *p = rq->curr; 2381 2382 lockdep_assert_rq_held(rq); 2383 2384 if (rq->push_busy) 2385 return NULL; 2386 2387 if (p->nr_cpus_allowed == 1) 2388 return NULL; 2389 2390 if (p->migration_disabled) 2391 return NULL; 2392 2393 rq->push_busy = true; 2394 return get_task_struct(p); 2395 } 2396 2397 extern int push_cpu_stop(void *arg); 2398 2399 #endif 2400 2401 #ifdef CONFIG_CPU_IDLE 2402 static inline void idle_set_state(struct rq *rq, 2403 struct cpuidle_state *idle_state) 2404 { 2405 rq->idle_state = idle_state; 2406 } 2407 2408 static inline struct cpuidle_state *idle_get_state(struct rq *rq) 2409 { 2410 SCHED_WARN_ON(!rcu_read_lock_held()); 2411 2412 return rq->idle_state; 2413 } 2414 #else 2415 static inline void idle_set_state(struct rq *rq, 2416 struct cpuidle_state *idle_state) 2417 { 2418 } 2419 2420 static inline struct cpuidle_state *idle_get_state(struct rq *rq) 2421 { 2422 return NULL; 2423 } 2424 #endif 2425 2426 extern void schedule_idle(void); 2427 asmlinkage void schedule_user(void); 2428 2429 extern void sysrq_sched_debug_show(void); 2430 extern void sched_init_granularity(void); 2431 extern void update_max_interval(void); 2432 2433 extern void init_sched_dl_class(void); 2434 extern void init_sched_rt_class(void); 2435 extern void init_sched_fair_class(void); 2436 2437 extern void reweight_task(struct task_struct *p, int prio); 2438 2439 extern void resched_curr(struct rq *rq); 2440 extern void resched_cpu(int cpu); 2441 2442 extern struct rt_bandwidth def_rt_bandwidth; 2443 extern void init_rt_bandwidth(struct rt_bandwidth *rt_b, u64 period, u64 runtime); 2444 extern bool sched_rt_bandwidth_account(struct rt_rq *rt_rq); 2445 2446 extern void init_dl_task_timer(struct sched_dl_entity *dl_se); 2447 extern void init_dl_inactive_task_timer(struct sched_dl_entity *dl_se); 2448 2449 #define BW_SHIFT 20 2450 #define BW_UNIT (1 << BW_SHIFT) 2451 #define RATIO_SHIFT 8 2452 #define MAX_BW_BITS (64 - BW_SHIFT) 2453 #define MAX_BW ((1ULL << MAX_BW_BITS) - 1) 2454 unsigned long to_ratio(u64 period, u64 runtime); 2455 2456 extern void init_entity_runnable_average(struct sched_entity *se); 2457 extern void post_init_entity_util_avg(struct task_struct *p); 2458 2459 #ifdef CONFIG_NO_HZ_FULL 2460 extern bool sched_can_stop_tick(struct rq *rq); 2461 extern int __init sched_tick_offload_init(void); 2462 2463 /* 2464 * Tick may be needed by tasks in the runqueue depending on their policy and 2465 * requirements. If tick is needed, lets send the target an IPI to kick it out of 2466 * nohz mode if necessary. 2467 */ 2468 static inline void sched_update_tick_dependency(struct rq *rq) 2469 { 2470 int cpu = cpu_of(rq); 2471 2472 if (!tick_nohz_full_cpu(cpu)) 2473 return; 2474 2475 if (sched_can_stop_tick(rq)) 2476 tick_nohz_dep_clear_cpu(cpu, TICK_DEP_BIT_SCHED); 2477 else 2478 tick_nohz_dep_set_cpu(cpu, TICK_DEP_BIT_SCHED); 2479 } 2480 #else 2481 static inline int sched_tick_offload_init(void) { return 0; } 2482 static inline void sched_update_tick_dependency(struct rq *rq) { } 2483 #endif 2484 2485 static inline void add_nr_running(struct rq *rq, unsigned count) 2486 { 2487 unsigned prev_nr = rq->nr_running; 2488 2489 rq->nr_running = prev_nr + count; 2490 if (trace_sched_update_nr_running_tp_enabled()) { 2491 call_trace_sched_update_nr_running(rq, count); 2492 } 2493 2494 #ifdef CONFIG_SMP 2495 if (prev_nr < 2 && rq->nr_running >= 2) { 2496 if (!READ_ONCE(rq->rd->overload)) 2497 WRITE_ONCE(rq->rd->overload, 1); 2498 } 2499 #endif 2500 2501 sched_update_tick_dependency(rq); 2502 } 2503 2504 static inline void sub_nr_running(struct rq *rq, unsigned count) 2505 { 2506 rq->nr_running -= count; 2507 if (trace_sched_update_nr_running_tp_enabled()) { 2508 call_trace_sched_update_nr_running(rq, -count); 2509 } 2510 2511 /* Check if we still need preemption */ 2512 sched_update_tick_dependency(rq); 2513 } 2514 2515 extern void activate_task(struct rq *rq, struct task_struct *p, int flags); 2516 extern void deactivate_task(struct rq *rq, struct task_struct *p, int flags); 2517 2518 extern void check_preempt_curr(struct rq *rq, struct task_struct *p, int flags); 2519 2520 #ifdef CONFIG_PREEMPT_RT 2521 #define SCHED_NR_MIGRATE_BREAK 8 2522 #else 2523 #define SCHED_NR_MIGRATE_BREAK 32 2524 #endif 2525 2526 extern const_debug unsigned int sysctl_sched_nr_migrate; 2527 extern const_debug unsigned int sysctl_sched_migration_cost; 2528 2529 extern unsigned int sysctl_sched_base_slice; 2530 2531 #ifdef CONFIG_SCHED_DEBUG 2532 extern int sysctl_resched_latency_warn_ms; 2533 extern int sysctl_resched_latency_warn_once; 2534 2535 extern unsigned int sysctl_sched_tunable_scaling; 2536 2537 extern unsigned int sysctl_numa_balancing_scan_delay; 2538 extern unsigned int sysctl_numa_balancing_scan_period_min; 2539 extern unsigned int sysctl_numa_balancing_scan_period_max; 2540 extern unsigned int sysctl_numa_balancing_scan_size; 2541 extern unsigned int sysctl_numa_balancing_hot_threshold; 2542 #endif 2543 2544 #ifdef CONFIG_SCHED_HRTICK 2545 2546 /* 2547 * Use hrtick when: 2548 * - enabled by features 2549 * - hrtimer is actually high res 2550 */ 2551 static inline int hrtick_enabled(struct rq *rq) 2552 { 2553 if (!cpu_active(cpu_of(rq))) 2554 return 0; 2555 return hrtimer_is_hres_active(&rq->hrtick_timer); 2556 } 2557 2558 static inline int hrtick_enabled_fair(struct rq *rq) 2559 { 2560 if (!sched_feat(HRTICK)) 2561 return 0; 2562 return hrtick_enabled(rq); 2563 } 2564 2565 static inline int hrtick_enabled_dl(struct rq *rq) 2566 { 2567 if (!sched_feat(HRTICK_DL)) 2568 return 0; 2569 return hrtick_enabled(rq); 2570 } 2571 2572 void hrtick_start(struct rq *rq, u64 delay); 2573 2574 #else 2575 2576 static inline int hrtick_enabled_fair(struct rq *rq) 2577 { 2578 return 0; 2579 } 2580 2581 static inline int hrtick_enabled_dl(struct rq *rq) 2582 { 2583 return 0; 2584 } 2585 2586 static inline int hrtick_enabled(struct rq *rq) 2587 { 2588 return 0; 2589 } 2590 2591 #endif /* CONFIG_SCHED_HRTICK */ 2592 2593 #ifndef arch_scale_freq_tick 2594 static __always_inline 2595 void arch_scale_freq_tick(void) 2596 { 2597 } 2598 #endif 2599 2600 #ifndef arch_scale_freq_capacity 2601 /** 2602 * arch_scale_freq_capacity - get the frequency scale factor of a given CPU. 2603 * @cpu: the CPU in question. 2604 * 2605 * Return: the frequency scale factor normalized against SCHED_CAPACITY_SCALE, i.e. 2606 * 2607 * f_curr 2608 * ------ * SCHED_CAPACITY_SCALE 2609 * f_max 2610 */ 2611 static __always_inline 2612 unsigned long arch_scale_freq_capacity(int cpu) 2613 { 2614 return SCHED_CAPACITY_SCALE; 2615 } 2616 #endif 2617 2618 #ifdef CONFIG_SCHED_DEBUG 2619 /* 2620 * In double_lock_balance()/double_rq_lock(), we use raw_spin_rq_lock() to 2621 * acquire rq lock instead of rq_lock(). So at the end of these two functions 2622 * we need to call double_rq_clock_clear_update() to clear RQCF_UPDATED of 2623 * rq->clock_update_flags to avoid the WARN_DOUBLE_CLOCK warning. 2624 */ 2625 static inline void double_rq_clock_clear_update(struct rq *rq1, struct rq *rq2) 2626 { 2627 rq1->clock_update_flags &= (RQCF_REQ_SKIP|RQCF_ACT_SKIP); 2628 /* rq1 == rq2 for !CONFIG_SMP, so just clear RQCF_UPDATED once. */ 2629 #ifdef CONFIG_SMP 2630 rq2->clock_update_flags &= (RQCF_REQ_SKIP|RQCF_ACT_SKIP); 2631 #endif 2632 } 2633 #else 2634 static inline void double_rq_clock_clear_update(struct rq *rq1, struct rq *rq2) {} 2635 #endif 2636 2637 #define DEFINE_LOCK_GUARD_2(name, type, _lock, _unlock, ...) \ 2638 __DEFINE_UNLOCK_GUARD(name, type, _unlock, type *lock2; __VA_ARGS__) \ 2639 static inline class_##name##_t class_##name##_constructor(type *lock, type *lock2) \ 2640 { class_##name##_t _t = { .lock = lock, .lock2 = lock2 }, *_T = &_t; \ 2641 _lock; return _t; } 2642 2643 #ifdef CONFIG_SMP 2644 2645 static inline bool rq_order_less(struct rq *rq1, struct rq *rq2) 2646 { 2647 #ifdef CONFIG_SCHED_CORE 2648 /* 2649 * In order to not have {0,2},{1,3} turn into into an AB-BA, 2650 * order by core-id first and cpu-id second. 2651 * 2652 * Notably: 2653 * 2654 * double_rq_lock(0,3); will take core-0, core-1 lock 2655 * double_rq_lock(1,2); will take core-1, core-0 lock 2656 * 2657 * when only cpu-id is considered. 2658 */ 2659 if (rq1->core->cpu < rq2->core->cpu) 2660 return true; 2661 if (rq1->core->cpu > rq2->core->cpu) 2662 return false; 2663 2664 /* 2665 * __sched_core_flip() relies on SMT having cpu-id lock order. 2666 */ 2667 #endif 2668 return rq1->cpu < rq2->cpu; 2669 } 2670 2671 extern void double_rq_lock(struct rq *rq1, struct rq *rq2); 2672 2673 #ifdef CONFIG_PREEMPTION 2674 2675 /* 2676 * fair double_lock_balance: Safely acquires both rq->locks in a fair 2677 * way at the expense of forcing extra atomic operations in all 2678 * invocations. This assures that the double_lock is acquired using the 2679 * same underlying policy as the spinlock_t on this architecture, which 2680 * reduces latency compared to the unfair variant below. However, it 2681 * also adds more overhead and therefore may reduce throughput. 2682 */ 2683 static inline int _double_lock_balance(struct rq *this_rq, struct rq *busiest) 2684 __releases(this_rq->lock) 2685 __acquires(busiest->lock) 2686 __acquires(this_rq->lock) 2687 { 2688 raw_spin_rq_unlock(this_rq); 2689 double_rq_lock(this_rq, busiest); 2690 2691 return 1; 2692 } 2693 2694 #else 2695 /* 2696 * Unfair double_lock_balance: Optimizes throughput at the expense of 2697 * latency by eliminating extra atomic operations when the locks are 2698 * already in proper order on entry. This favors lower CPU-ids and will 2699 * grant the double lock to lower CPUs over higher ids under contention, 2700 * regardless of entry order into the function. 2701 */ 2702 static inline int _double_lock_balance(struct rq *this_rq, struct rq *busiest) 2703 __releases(this_rq->lock) 2704 __acquires(busiest->lock) 2705 __acquires(this_rq->lock) 2706 { 2707 if (__rq_lockp(this_rq) == __rq_lockp(busiest) || 2708 likely(raw_spin_rq_trylock(busiest))) { 2709 double_rq_clock_clear_update(this_rq, busiest); 2710 return 0; 2711 } 2712 2713 if (rq_order_less(this_rq, busiest)) { 2714 raw_spin_rq_lock_nested(busiest, SINGLE_DEPTH_NESTING); 2715 double_rq_clock_clear_update(this_rq, busiest); 2716 return 0; 2717 } 2718 2719 raw_spin_rq_unlock(this_rq); 2720 double_rq_lock(this_rq, busiest); 2721 2722 return 1; 2723 } 2724 2725 #endif /* CONFIG_PREEMPTION */ 2726 2727 /* 2728 * double_lock_balance - lock the busiest runqueue, this_rq is locked already. 2729 */ 2730 static inline int double_lock_balance(struct rq *this_rq, struct rq *busiest) 2731 { 2732 lockdep_assert_irqs_disabled(); 2733 2734 return _double_lock_balance(this_rq, busiest); 2735 } 2736 2737 static inline void double_unlock_balance(struct rq *this_rq, struct rq *busiest) 2738 __releases(busiest->lock) 2739 { 2740 if (__rq_lockp(this_rq) != __rq_lockp(busiest)) 2741 raw_spin_rq_unlock(busiest); 2742 lock_set_subclass(&__rq_lockp(this_rq)->dep_map, 0, _RET_IP_); 2743 } 2744 2745 static inline void double_lock(spinlock_t *l1, spinlock_t *l2) 2746 { 2747 if (l1 > l2) 2748 swap(l1, l2); 2749 2750 spin_lock(l1); 2751 spin_lock_nested(l2, SINGLE_DEPTH_NESTING); 2752 } 2753 2754 static inline void double_lock_irq(spinlock_t *l1, spinlock_t *l2) 2755 { 2756 if (l1 > l2) 2757 swap(l1, l2); 2758 2759 spin_lock_irq(l1); 2760 spin_lock_nested(l2, SINGLE_DEPTH_NESTING); 2761 } 2762 2763 static inline void double_raw_lock(raw_spinlock_t *l1, raw_spinlock_t *l2) 2764 { 2765 if (l1 > l2) 2766 swap(l1, l2); 2767 2768 raw_spin_lock(l1); 2769 raw_spin_lock_nested(l2, SINGLE_DEPTH_NESTING); 2770 } 2771 2772 static inline void double_raw_unlock(raw_spinlock_t *l1, raw_spinlock_t *l2) 2773 { 2774 raw_spin_unlock(l1); 2775 raw_spin_unlock(l2); 2776 } 2777 2778 DEFINE_LOCK_GUARD_2(double_raw_spinlock, raw_spinlock_t, 2779 double_raw_lock(_T->lock, _T->lock2), 2780 double_raw_unlock(_T->lock, _T->lock2)) 2781 2782 /* 2783 * double_rq_unlock - safely unlock two runqueues 2784 * 2785 * Note this does not restore interrupts like task_rq_unlock, 2786 * you need to do so manually after calling. 2787 */ 2788 static inline void double_rq_unlock(struct rq *rq1, struct rq *rq2) 2789 __releases(rq1->lock) 2790 __releases(rq2->lock) 2791 { 2792 if (__rq_lockp(rq1) != __rq_lockp(rq2)) 2793 raw_spin_rq_unlock(rq2); 2794 else 2795 __release(rq2->lock); 2796 raw_spin_rq_unlock(rq1); 2797 } 2798 2799 extern void set_rq_online (struct rq *rq); 2800 extern void set_rq_offline(struct rq *rq); 2801 extern bool sched_smp_initialized; 2802 2803 #else /* CONFIG_SMP */ 2804 2805 /* 2806 * double_rq_lock - safely lock two runqueues 2807 * 2808 * Note this does not disable interrupts like task_rq_lock, 2809 * you need to do so manually before calling. 2810 */ 2811 static inline void double_rq_lock(struct rq *rq1, struct rq *rq2) 2812 __acquires(rq1->lock) 2813 __acquires(rq2->lock) 2814 { 2815 WARN_ON_ONCE(!irqs_disabled()); 2816 WARN_ON_ONCE(rq1 != rq2); 2817 raw_spin_rq_lock(rq1); 2818 __acquire(rq2->lock); /* Fake it out ;) */ 2819 double_rq_clock_clear_update(rq1, rq2); 2820 } 2821 2822 /* 2823 * double_rq_unlock - safely unlock two runqueues 2824 * 2825 * Note this does not restore interrupts like task_rq_unlock, 2826 * you need to do so manually after calling. 2827 */ 2828 static inline void double_rq_unlock(struct rq *rq1, struct rq *rq2) 2829 __releases(rq1->lock) 2830 __releases(rq2->lock) 2831 { 2832 WARN_ON_ONCE(rq1 != rq2); 2833 raw_spin_rq_unlock(rq1); 2834 __release(rq2->lock); 2835 } 2836 2837 #endif 2838 2839 DEFINE_LOCK_GUARD_2(double_rq_lock, struct rq, 2840 double_rq_lock(_T->lock, _T->lock2), 2841 double_rq_unlock(_T->lock, _T->lock2)) 2842 2843 extern struct sched_entity *__pick_first_entity(struct cfs_rq *cfs_rq); 2844 extern struct sched_entity *__pick_last_entity(struct cfs_rq *cfs_rq); 2845 2846 #ifdef CONFIG_SCHED_DEBUG 2847 extern bool sched_debug_verbose; 2848 2849 extern void print_cfs_stats(struct seq_file *m, int cpu); 2850 extern void print_rt_stats(struct seq_file *m, int cpu); 2851 extern void print_dl_stats(struct seq_file *m, int cpu); 2852 extern void print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq); 2853 extern void print_rt_rq(struct seq_file *m, int cpu, struct rt_rq *rt_rq); 2854 extern void print_dl_rq(struct seq_file *m, int cpu, struct dl_rq *dl_rq); 2855 2856 extern void resched_latency_warn(int cpu, u64 latency); 2857 #ifdef CONFIG_NUMA_BALANCING 2858 extern void 2859 show_numa_stats(struct task_struct *p, struct seq_file *m); 2860 extern void 2861 print_numa_stats(struct seq_file *m, int node, unsigned long tsf, 2862 unsigned long tpf, unsigned long gsf, unsigned long gpf); 2863 #endif /* CONFIG_NUMA_BALANCING */ 2864 #else 2865 static inline void resched_latency_warn(int cpu, u64 latency) {} 2866 #endif /* CONFIG_SCHED_DEBUG */ 2867 2868 extern void init_cfs_rq(struct cfs_rq *cfs_rq); 2869 extern void init_rt_rq(struct rt_rq *rt_rq); 2870 extern void init_dl_rq(struct dl_rq *dl_rq); 2871 2872 extern void cfs_bandwidth_usage_inc(void); 2873 extern void cfs_bandwidth_usage_dec(void); 2874 2875 #ifdef CONFIG_NO_HZ_COMMON 2876 #define NOHZ_BALANCE_KICK_BIT 0 2877 #define NOHZ_STATS_KICK_BIT 1 2878 #define NOHZ_NEWILB_KICK_BIT 2 2879 #define NOHZ_NEXT_KICK_BIT 3 2880 2881 /* Run rebalance_domains() */ 2882 #define NOHZ_BALANCE_KICK BIT(NOHZ_BALANCE_KICK_BIT) 2883 /* Update blocked load */ 2884 #define NOHZ_STATS_KICK BIT(NOHZ_STATS_KICK_BIT) 2885 /* Update blocked load when entering idle */ 2886 #define NOHZ_NEWILB_KICK BIT(NOHZ_NEWILB_KICK_BIT) 2887 /* Update nohz.next_balance */ 2888 #define NOHZ_NEXT_KICK BIT(NOHZ_NEXT_KICK_BIT) 2889 2890 #define NOHZ_KICK_MASK (NOHZ_BALANCE_KICK | NOHZ_STATS_KICK | NOHZ_NEXT_KICK) 2891 2892 #define nohz_flags(cpu) (&cpu_rq(cpu)->nohz_flags) 2893 2894 extern void nohz_balance_exit_idle(struct rq *rq); 2895 #else 2896 static inline void nohz_balance_exit_idle(struct rq *rq) { } 2897 #endif 2898 2899 #if defined(CONFIG_SMP) && defined(CONFIG_NO_HZ_COMMON) 2900 extern void nohz_run_idle_balance(int cpu); 2901 #else 2902 static inline void nohz_run_idle_balance(int cpu) { } 2903 #endif 2904 2905 #ifdef CONFIG_IRQ_TIME_ACCOUNTING 2906 struct irqtime { 2907 u64 total; 2908 u64 tick_delta; 2909 u64 irq_start_time; 2910 struct u64_stats_sync sync; 2911 }; 2912 2913 DECLARE_PER_CPU(struct irqtime, cpu_irqtime); 2914 2915 /* 2916 * Returns the irqtime minus the softirq time computed by ksoftirqd. 2917 * Otherwise ksoftirqd's sum_exec_runtime is subtracted its own runtime 2918 * and never move forward. 2919 */ 2920 static inline u64 irq_time_read(int cpu) 2921 { 2922 struct irqtime *irqtime = &per_cpu(cpu_irqtime, cpu); 2923 unsigned int seq; 2924 u64 total; 2925 2926 do { 2927 seq = __u64_stats_fetch_begin(&irqtime->sync); 2928 total = irqtime->total; 2929 } while (__u64_stats_fetch_retry(&irqtime->sync, seq)); 2930 2931 return total; 2932 } 2933 #endif /* CONFIG_IRQ_TIME_ACCOUNTING */ 2934 2935 #ifdef CONFIG_CPU_FREQ 2936 DECLARE_PER_CPU(struct update_util_data __rcu *, cpufreq_update_util_data); 2937 2938 /** 2939 * cpufreq_update_util - Take a note about CPU utilization changes. 2940 * @rq: Runqueue to carry out the update for. 2941 * @flags: Update reason flags. 2942 * 2943 * This function is called by the scheduler on the CPU whose utilization is 2944 * being updated. 2945 * 2946 * It can only be called from RCU-sched read-side critical sections. 2947 * 2948 * The way cpufreq is currently arranged requires it to evaluate the CPU 2949 * performance state (frequency/voltage) on a regular basis to prevent it from 2950 * being stuck in a completely inadequate performance level for too long. 2951 * That is not guaranteed to happen if the updates are only triggered from CFS 2952 * and DL, though, because they may not be coming in if only RT tasks are 2953 * active all the time (or there are RT tasks only). 2954 * 2955 * As a workaround for that issue, this function is called periodically by the 2956 * RT sched class to trigger extra cpufreq updates to prevent it from stalling, 2957 * but that really is a band-aid. Going forward it should be replaced with 2958 * solutions targeted more specifically at RT tasks. 2959 */ 2960 static inline void cpufreq_update_util(struct rq *rq, unsigned int flags) 2961 { 2962 struct update_util_data *data; 2963 2964 data = rcu_dereference_sched(*per_cpu_ptr(&cpufreq_update_util_data, 2965 cpu_of(rq))); 2966 if (data) 2967 data->func(data, rq_clock(rq), flags); 2968 } 2969 #else 2970 static inline void cpufreq_update_util(struct rq *rq, unsigned int flags) {} 2971 #endif /* CONFIG_CPU_FREQ */ 2972 2973 #ifdef arch_scale_freq_capacity 2974 # ifndef arch_scale_freq_invariant 2975 # define arch_scale_freq_invariant() true 2976 # endif 2977 #else 2978 # define arch_scale_freq_invariant() false 2979 #endif 2980 2981 #ifdef CONFIG_SMP 2982 static inline unsigned long capacity_orig_of(int cpu) 2983 { 2984 return cpu_rq(cpu)->cpu_capacity_orig; 2985 } 2986 2987 /** 2988 * enum cpu_util_type - CPU utilization type 2989 * @FREQUENCY_UTIL: Utilization used to select frequency 2990 * @ENERGY_UTIL: Utilization used during energy calculation 2991 * 2992 * The utilization signals of all scheduling classes (CFS/RT/DL) and IRQ time 2993 * need to be aggregated differently depending on the usage made of them. This 2994 * enum is used within effective_cpu_util() to differentiate the types of 2995 * utilization expected by the callers, and adjust the aggregation accordingly. 2996 */ 2997 enum cpu_util_type { 2998 FREQUENCY_UTIL, 2999 ENERGY_UTIL, 3000 }; 3001 3002 unsigned long effective_cpu_util(int cpu, unsigned long util_cfs, 3003 enum cpu_util_type type, 3004 struct task_struct *p); 3005 3006 /* 3007 * Verify the fitness of task @p to run on @cpu taking into account the 3008 * CPU original capacity and the runtime/deadline ratio of the task. 3009 * 3010 * The function will return true if the original capacity of @cpu is 3011 * greater than or equal to task's deadline density right shifted by 3012 * (BW_SHIFT - SCHED_CAPACITY_SHIFT) and false otherwise. 3013 */ 3014 static inline bool dl_task_fits_capacity(struct task_struct *p, int cpu) 3015 { 3016 unsigned long cap = arch_scale_cpu_capacity(cpu); 3017 3018 return cap >= p->dl.dl_density >> (BW_SHIFT - SCHED_CAPACITY_SHIFT); 3019 } 3020 3021 static inline unsigned long cpu_bw_dl(struct rq *rq) 3022 { 3023 return (rq->dl.running_bw * SCHED_CAPACITY_SCALE) >> BW_SHIFT; 3024 } 3025 3026 static inline unsigned long cpu_util_dl(struct rq *rq) 3027 { 3028 return READ_ONCE(rq->avg_dl.util_avg); 3029 } 3030 3031 3032 extern unsigned long cpu_util_cfs(int cpu); 3033 extern unsigned long cpu_util_cfs_boost(int cpu); 3034 3035 static inline unsigned long cpu_util_rt(struct rq *rq) 3036 { 3037 return READ_ONCE(rq->avg_rt.util_avg); 3038 } 3039 #endif 3040 3041 #ifdef CONFIG_UCLAMP_TASK 3042 unsigned long uclamp_eff_value(struct task_struct *p, enum uclamp_id clamp_id); 3043 3044 static inline unsigned long uclamp_rq_get(struct rq *rq, 3045 enum uclamp_id clamp_id) 3046 { 3047 return READ_ONCE(rq->uclamp[clamp_id].value); 3048 } 3049 3050 static inline void uclamp_rq_set(struct rq *rq, enum uclamp_id clamp_id, 3051 unsigned int value) 3052 { 3053 WRITE_ONCE(rq->uclamp[clamp_id].value, value); 3054 } 3055 3056 static inline bool uclamp_rq_is_idle(struct rq *rq) 3057 { 3058 return rq->uclamp_flags & UCLAMP_FLAG_IDLE; 3059 } 3060 3061 /** 3062 * uclamp_rq_util_with - clamp @util with @rq and @p effective uclamp values. 3063 * @rq: The rq to clamp against. Must not be NULL. 3064 * @util: The util value to clamp. 3065 * @p: The task to clamp against. Can be NULL if you want to clamp 3066 * against @rq only. 3067 * 3068 * Clamps the passed @util to the max(@rq, @p) effective uclamp values. 3069 * 3070 * If sched_uclamp_used static key is disabled, then just return the util 3071 * without any clamping since uclamp aggregation at the rq level in the fast 3072 * path is disabled, rendering this operation a NOP. 3073 * 3074 * Use uclamp_eff_value() if you don't care about uclamp values at rq level. It 3075 * will return the correct effective uclamp value of the task even if the 3076 * static key is disabled. 3077 */ 3078 static __always_inline 3079 unsigned long uclamp_rq_util_with(struct rq *rq, unsigned long util, 3080 struct task_struct *p) 3081 { 3082 unsigned long min_util = 0; 3083 unsigned long max_util = 0; 3084 3085 if (!static_branch_likely(&sched_uclamp_used)) 3086 return util; 3087 3088 if (p) { 3089 min_util = uclamp_eff_value(p, UCLAMP_MIN); 3090 max_util = uclamp_eff_value(p, UCLAMP_MAX); 3091 3092 /* 3093 * Ignore last runnable task's max clamp, as this task will 3094 * reset it. Similarly, no need to read the rq's min clamp. 3095 */ 3096 if (uclamp_rq_is_idle(rq)) 3097 goto out; 3098 } 3099 3100 min_util = max_t(unsigned long, min_util, uclamp_rq_get(rq, UCLAMP_MIN)); 3101 max_util = max_t(unsigned long, max_util, uclamp_rq_get(rq, UCLAMP_MAX)); 3102 out: 3103 /* 3104 * Since CPU's {min,max}_util clamps are MAX aggregated considering 3105 * RUNNABLE tasks with _different_ clamps, we can end up with an 3106 * inversion. Fix it now when the clamps are applied. 3107 */ 3108 if (unlikely(min_util >= max_util)) 3109 return min_util; 3110 3111 return clamp(util, min_util, max_util); 3112 } 3113 3114 /* Is the rq being capped/throttled by uclamp_max? */ 3115 static inline bool uclamp_rq_is_capped(struct rq *rq) 3116 { 3117 unsigned long rq_util; 3118 unsigned long max_util; 3119 3120 if (!static_branch_likely(&sched_uclamp_used)) 3121 return false; 3122 3123 rq_util = cpu_util_cfs(cpu_of(rq)) + cpu_util_rt(rq); 3124 max_util = READ_ONCE(rq->uclamp[UCLAMP_MAX].value); 3125 3126 return max_util != SCHED_CAPACITY_SCALE && rq_util >= max_util; 3127 } 3128 3129 /* 3130 * When uclamp is compiled in, the aggregation at rq level is 'turned off' 3131 * by default in the fast path and only gets turned on once userspace performs 3132 * an operation that requires it. 3133 * 3134 * Returns true if userspace opted-in to use uclamp and aggregation at rq level 3135 * hence is active. 3136 */ 3137 static inline bool uclamp_is_used(void) 3138 { 3139 return static_branch_likely(&sched_uclamp_used); 3140 } 3141 #else /* CONFIG_UCLAMP_TASK */ 3142 static inline unsigned long uclamp_eff_value(struct task_struct *p, 3143 enum uclamp_id clamp_id) 3144 { 3145 if (clamp_id == UCLAMP_MIN) 3146 return 0; 3147 3148 return SCHED_CAPACITY_SCALE; 3149 } 3150 3151 static inline 3152 unsigned long uclamp_rq_util_with(struct rq *rq, unsigned long util, 3153 struct task_struct *p) 3154 { 3155 return util; 3156 } 3157 3158 static inline bool uclamp_rq_is_capped(struct rq *rq) { return false; } 3159 3160 static inline bool uclamp_is_used(void) 3161 { 3162 return false; 3163 } 3164 3165 static inline unsigned long uclamp_rq_get(struct rq *rq, 3166 enum uclamp_id clamp_id) 3167 { 3168 if (clamp_id == UCLAMP_MIN) 3169 return 0; 3170 3171 return SCHED_CAPACITY_SCALE; 3172 } 3173 3174 static inline void uclamp_rq_set(struct rq *rq, enum uclamp_id clamp_id, 3175 unsigned int value) 3176 { 3177 } 3178 3179 static inline bool uclamp_rq_is_idle(struct rq *rq) 3180 { 3181 return false; 3182 } 3183 #endif /* CONFIG_UCLAMP_TASK */ 3184 3185 #ifdef CONFIG_HAVE_SCHED_AVG_IRQ 3186 static inline unsigned long cpu_util_irq(struct rq *rq) 3187 { 3188 return rq->avg_irq.util_avg; 3189 } 3190 3191 static inline 3192 unsigned long scale_irq_capacity(unsigned long util, unsigned long irq, unsigned long max) 3193 { 3194 util *= (max - irq); 3195 util /= max; 3196 3197 return util; 3198 3199 } 3200 #else 3201 static inline unsigned long cpu_util_irq(struct rq *rq) 3202 { 3203 return 0; 3204 } 3205 3206 static inline 3207 unsigned long scale_irq_capacity(unsigned long util, unsigned long irq, unsigned long max) 3208 { 3209 return util; 3210 } 3211 #endif 3212 3213 #if defined(CONFIG_ENERGY_MODEL) && defined(CONFIG_CPU_FREQ_GOV_SCHEDUTIL) 3214 3215 #define perf_domain_span(pd) (to_cpumask(((pd)->em_pd->cpus))) 3216 3217 DECLARE_STATIC_KEY_FALSE(sched_energy_present); 3218 3219 static inline bool sched_energy_enabled(void) 3220 { 3221 return static_branch_unlikely(&sched_energy_present); 3222 } 3223 3224 #else /* ! (CONFIG_ENERGY_MODEL && CONFIG_CPU_FREQ_GOV_SCHEDUTIL) */ 3225 3226 #define perf_domain_span(pd) NULL 3227 static inline bool sched_energy_enabled(void) { return false; } 3228 3229 #endif /* CONFIG_ENERGY_MODEL && CONFIG_CPU_FREQ_GOV_SCHEDUTIL */ 3230 3231 #ifdef CONFIG_MEMBARRIER 3232 /* 3233 * The scheduler provides memory barriers required by membarrier between: 3234 * - prior user-space memory accesses and store to rq->membarrier_state, 3235 * - store to rq->membarrier_state and following user-space memory accesses. 3236 * In the same way it provides those guarantees around store to rq->curr. 3237 */ 3238 static inline void membarrier_switch_mm(struct rq *rq, 3239 struct mm_struct *prev_mm, 3240 struct mm_struct *next_mm) 3241 { 3242 int membarrier_state; 3243 3244 if (prev_mm == next_mm) 3245 return; 3246 3247 membarrier_state = atomic_read(&next_mm->membarrier_state); 3248 if (READ_ONCE(rq->membarrier_state) == membarrier_state) 3249 return; 3250 3251 WRITE_ONCE(rq->membarrier_state, membarrier_state); 3252 } 3253 #else 3254 static inline void membarrier_switch_mm(struct rq *rq, 3255 struct mm_struct *prev_mm, 3256 struct mm_struct *next_mm) 3257 { 3258 } 3259 #endif 3260 3261 #ifdef CONFIG_SMP 3262 static inline bool is_per_cpu_kthread(struct task_struct *p) 3263 { 3264 if (!(p->flags & PF_KTHREAD)) 3265 return false; 3266 3267 if (p->nr_cpus_allowed != 1) 3268 return false; 3269 3270 return true; 3271 } 3272 #endif 3273 3274 extern void swake_up_all_locked(struct swait_queue_head *q); 3275 extern void __prepare_to_swait(struct swait_queue_head *q, struct swait_queue *wait); 3276 3277 extern int try_to_wake_up(struct task_struct *tsk, unsigned int state, int wake_flags); 3278 3279 #ifdef CONFIG_PREEMPT_DYNAMIC 3280 extern int preempt_dynamic_mode; 3281 extern int sched_dynamic_mode(const char *str); 3282 extern void sched_dynamic_update(int mode); 3283 #endif 3284 3285 static inline void update_current_exec_runtime(struct task_struct *curr, 3286 u64 now, u64 delta_exec) 3287 { 3288 curr->se.sum_exec_runtime += delta_exec; 3289 account_group_exec_runtime(curr, delta_exec); 3290 3291 curr->se.exec_start = now; 3292 cgroup_account_cputime(curr, delta_exec); 3293 } 3294 3295 #ifdef CONFIG_SCHED_MM_CID 3296 3297 #define SCHED_MM_CID_PERIOD_NS (100ULL * 1000000) /* 100ms */ 3298 #define MM_CID_SCAN_DELAY 100 /* 100ms */ 3299 3300 extern raw_spinlock_t cid_lock; 3301 extern int use_cid_lock; 3302 3303 extern void sched_mm_cid_migrate_from(struct task_struct *t); 3304 extern void sched_mm_cid_migrate_to(struct rq *dst_rq, struct task_struct *t); 3305 extern void task_tick_mm_cid(struct rq *rq, struct task_struct *curr); 3306 extern void init_sched_mm_cid(struct task_struct *t); 3307 3308 static inline void __mm_cid_put(struct mm_struct *mm, int cid) 3309 { 3310 if (cid < 0) 3311 return; 3312 cpumask_clear_cpu(cid, mm_cidmask(mm)); 3313 } 3314 3315 /* 3316 * The per-mm/cpu cid can have the MM_CID_LAZY_PUT flag set or transition to 3317 * the MM_CID_UNSET state without holding the rq lock, but the rq lock needs to 3318 * be held to transition to other states. 3319 * 3320 * State transitions synchronized with cmpxchg or try_cmpxchg need to be 3321 * consistent across cpus, which prevents use of this_cpu_cmpxchg. 3322 */ 3323 static inline void mm_cid_put_lazy(struct task_struct *t) 3324 { 3325 struct mm_struct *mm = t->mm; 3326 struct mm_cid __percpu *pcpu_cid = mm->pcpu_cid; 3327 int cid; 3328 3329 lockdep_assert_irqs_disabled(); 3330 cid = __this_cpu_read(pcpu_cid->cid); 3331 if (!mm_cid_is_lazy_put(cid) || 3332 !try_cmpxchg(&this_cpu_ptr(pcpu_cid)->cid, &cid, MM_CID_UNSET)) 3333 return; 3334 __mm_cid_put(mm, mm_cid_clear_lazy_put(cid)); 3335 } 3336 3337 static inline int mm_cid_pcpu_unset(struct mm_struct *mm) 3338 { 3339 struct mm_cid __percpu *pcpu_cid = mm->pcpu_cid; 3340 int cid, res; 3341 3342 lockdep_assert_irqs_disabled(); 3343 cid = __this_cpu_read(pcpu_cid->cid); 3344 for (;;) { 3345 if (mm_cid_is_unset(cid)) 3346 return MM_CID_UNSET; 3347 /* 3348 * Attempt transition from valid or lazy-put to unset. 3349 */ 3350 res = cmpxchg(&this_cpu_ptr(pcpu_cid)->cid, cid, MM_CID_UNSET); 3351 if (res == cid) 3352 break; 3353 cid = res; 3354 } 3355 return cid; 3356 } 3357 3358 static inline void mm_cid_put(struct mm_struct *mm) 3359 { 3360 int cid; 3361 3362 lockdep_assert_irqs_disabled(); 3363 cid = mm_cid_pcpu_unset(mm); 3364 if (cid == MM_CID_UNSET) 3365 return; 3366 __mm_cid_put(mm, mm_cid_clear_lazy_put(cid)); 3367 } 3368 3369 static inline int __mm_cid_try_get(struct mm_struct *mm) 3370 { 3371 struct cpumask *cpumask; 3372 int cid; 3373 3374 cpumask = mm_cidmask(mm); 3375 /* 3376 * Retry finding first zero bit if the mask is temporarily 3377 * filled. This only happens during concurrent remote-clear 3378 * which owns a cid without holding a rq lock. 3379 */ 3380 for (;;) { 3381 cid = cpumask_first_zero(cpumask); 3382 if (cid < nr_cpu_ids) 3383 break; 3384 cpu_relax(); 3385 } 3386 if (cpumask_test_and_set_cpu(cid, cpumask)) 3387 return -1; 3388 return cid; 3389 } 3390 3391 /* 3392 * Save a snapshot of the current runqueue time of this cpu 3393 * with the per-cpu cid value, allowing to estimate how recently it was used. 3394 */ 3395 static inline void mm_cid_snapshot_time(struct rq *rq, struct mm_struct *mm) 3396 { 3397 struct mm_cid *pcpu_cid = per_cpu_ptr(mm->pcpu_cid, cpu_of(rq)); 3398 3399 lockdep_assert_rq_held(rq); 3400 WRITE_ONCE(pcpu_cid->time, rq->clock); 3401 } 3402 3403 static inline int __mm_cid_get(struct rq *rq, struct mm_struct *mm) 3404 { 3405 int cid; 3406 3407 /* 3408 * All allocations (even those using the cid_lock) are lock-free. If 3409 * use_cid_lock is set, hold the cid_lock to perform cid allocation to 3410 * guarantee forward progress. 3411 */ 3412 if (!READ_ONCE(use_cid_lock)) { 3413 cid = __mm_cid_try_get(mm); 3414 if (cid >= 0) 3415 goto end; 3416 raw_spin_lock(&cid_lock); 3417 } else { 3418 raw_spin_lock(&cid_lock); 3419 cid = __mm_cid_try_get(mm); 3420 if (cid >= 0) 3421 goto unlock; 3422 } 3423 3424 /* 3425 * cid concurrently allocated. Retry while forcing following 3426 * allocations to use the cid_lock to ensure forward progress. 3427 */ 3428 WRITE_ONCE(use_cid_lock, 1); 3429 /* 3430 * Set use_cid_lock before allocation. Only care about program order 3431 * because this is only required for forward progress. 3432 */ 3433 barrier(); 3434 /* 3435 * Retry until it succeeds. It is guaranteed to eventually succeed once 3436 * all newcoming allocations observe the use_cid_lock flag set. 3437 */ 3438 do { 3439 cid = __mm_cid_try_get(mm); 3440 cpu_relax(); 3441 } while (cid < 0); 3442 /* 3443 * Allocate before clearing use_cid_lock. Only care about 3444 * program order because this is for forward progress. 3445 */ 3446 barrier(); 3447 WRITE_ONCE(use_cid_lock, 0); 3448 unlock: 3449 raw_spin_unlock(&cid_lock); 3450 end: 3451 mm_cid_snapshot_time(rq, mm); 3452 return cid; 3453 } 3454 3455 static inline int mm_cid_get(struct rq *rq, struct mm_struct *mm) 3456 { 3457 struct mm_cid __percpu *pcpu_cid = mm->pcpu_cid; 3458 struct cpumask *cpumask; 3459 int cid; 3460 3461 lockdep_assert_rq_held(rq); 3462 cpumask = mm_cidmask(mm); 3463 cid = __this_cpu_read(pcpu_cid->cid); 3464 if (mm_cid_is_valid(cid)) { 3465 mm_cid_snapshot_time(rq, mm); 3466 return cid; 3467 } 3468 if (mm_cid_is_lazy_put(cid)) { 3469 if (try_cmpxchg(&this_cpu_ptr(pcpu_cid)->cid, &cid, MM_CID_UNSET)) 3470 __mm_cid_put(mm, mm_cid_clear_lazy_put(cid)); 3471 } 3472 cid = __mm_cid_get(rq, mm); 3473 __this_cpu_write(pcpu_cid->cid, cid); 3474 return cid; 3475 } 3476 3477 static inline void switch_mm_cid(struct rq *rq, 3478 struct task_struct *prev, 3479 struct task_struct *next) 3480 { 3481 /* 3482 * Provide a memory barrier between rq->curr store and load of 3483 * {prev,next}->mm->pcpu_cid[cpu] on rq->curr->mm transition. 3484 * 3485 * Should be adapted if context_switch() is modified. 3486 */ 3487 if (!next->mm) { // to kernel 3488 /* 3489 * user -> kernel transition does not guarantee a barrier, but 3490 * we can use the fact that it performs an atomic operation in 3491 * mmgrab(). 3492 */ 3493 if (prev->mm) // from user 3494 smp_mb__after_mmgrab(); 3495 /* 3496 * kernel -> kernel transition does not change rq->curr->mm 3497 * state. It stays NULL. 3498 */ 3499 } else { // to user 3500 /* 3501 * kernel -> user transition does not provide a barrier 3502 * between rq->curr store and load of {prev,next}->mm->pcpu_cid[cpu]. 3503 * Provide it here. 3504 */ 3505 if (!prev->mm) { // from kernel 3506 smp_mb(); 3507 } else { // from user 3508 /* 3509 * user->user transition relies on an implicit 3510 * memory barrier in switch_mm() when 3511 * current->mm changes. If the architecture 3512 * switch_mm() does not have an implicit memory 3513 * barrier, it is emitted here. If current->mm 3514 * is unchanged, no barrier is needed. 3515 */ 3516 smp_mb__after_switch_mm(); 3517 } 3518 } 3519 if (prev->mm_cid_active) { 3520 mm_cid_snapshot_time(rq, prev->mm); 3521 mm_cid_put_lazy(prev); 3522 prev->mm_cid = -1; 3523 } 3524 if (next->mm_cid_active) 3525 next->last_mm_cid = next->mm_cid = mm_cid_get(rq, next->mm); 3526 } 3527 3528 #else 3529 static inline void switch_mm_cid(struct rq *rq, struct task_struct *prev, struct task_struct *next) { } 3530 static inline void sched_mm_cid_migrate_from(struct task_struct *t) { } 3531 static inline void sched_mm_cid_migrate_to(struct rq *dst_rq, struct task_struct *t) { } 3532 static inline void task_tick_mm_cid(struct rq *rq, struct task_struct *curr) { } 3533 static inline void init_sched_mm_cid(struct task_struct *t) { } 3534 #endif 3535 3536 extern u64 avg_vruntime(struct cfs_rq *cfs_rq); 3537 extern int entity_eligible(struct cfs_rq *cfs_rq, struct sched_entity *se); 3538 3539 #endif /* _KERNEL_SCHED_SCHED_H */ 3540