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 "cpupri.h" 92 #include "cpudeadline.h" 93 94 #ifdef CONFIG_SCHED_DEBUG 95 # define SCHED_WARN_ON(x) WARN_ONCE(x, #x) 96 #else 97 # define SCHED_WARN_ON(x) ({ (void)(x), 0; }) 98 #endif 99 100 struct rq; 101 struct cpuidle_state; 102 103 /* task_struct::on_rq states: */ 104 #define TASK_ON_RQ_QUEUED 1 105 #define TASK_ON_RQ_MIGRATING 2 106 107 extern __read_mostly int scheduler_running; 108 109 extern unsigned long calc_load_update; 110 extern atomic_long_t calc_load_tasks; 111 112 extern unsigned int sysctl_sched_child_runs_first; 113 114 extern void calc_global_load_tick(struct rq *this_rq); 115 extern long calc_load_fold_active(struct rq *this_rq, long adjust); 116 117 extern void call_trace_sched_update_nr_running(struct rq *rq, int count); 118 119 extern unsigned int sysctl_sched_rt_period; 120 extern int sysctl_sched_rt_runtime; 121 extern int sched_rr_timeslice; 122 123 /* 124 * Helpers for converting nanosecond timing to jiffy resolution 125 */ 126 #define NS_TO_JIFFIES(TIME) ((unsigned long)(TIME) / (NSEC_PER_SEC / HZ)) 127 128 /* 129 * Increase resolution of nice-level calculations for 64-bit architectures. 130 * The extra resolution improves shares distribution and load balancing of 131 * low-weight task groups (eg. nice +19 on an autogroup), deeper taskgroup 132 * hierarchies, especially on larger systems. This is not a user-visible change 133 * and does not change the user-interface for setting shares/weights. 134 * 135 * We increase resolution only if we have enough bits to allow this increased 136 * resolution (i.e. 64-bit). The costs for increasing resolution when 32-bit 137 * are pretty high and the returns do not justify the increased costs. 138 * 139 * Really only required when CONFIG_FAIR_GROUP_SCHED=y is also set, but to 140 * increase coverage and consistency always enable it on 64-bit platforms. 141 */ 142 #ifdef CONFIG_64BIT 143 # define NICE_0_LOAD_SHIFT (SCHED_FIXEDPOINT_SHIFT + SCHED_FIXEDPOINT_SHIFT) 144 # define scale_load(w) ((w) << SCHED_FIXEDPOINT_SHIFT) 145 # define scale_load_down(w) \ 146 ({ \ 147 unsigned long __w = (w); \ 148 if (__w) \ 149 __w = max(2UL, __w >> SCHED_FIXEDPOINT_SHIFT); \ 150 __w; \ 151 }) 152 #else 153 # define NICE_0_LOAD_SHIFT (SCHED_FIXEDPOINT_SHIFT) 154 # define scale_load(w) (w) 155 # define scale_load_down(w) (w) 156 #endif 157 158 /* 159 * Task weight (visible to users) and its load (invisible to users) have 160 * independent resolution, but they should be well calibrated. We use 161 * scale_load() and scale_load_down(w) to convert between them. The 162 * following must be true: 163 * 164 * scale_load(sched_prio_to_weight[NICE_TO_PRIO(0)-MAX_RT_PRIO]) == NICE_0_LOAD 165 * 166 */ 167 #define NICE_0_LOAD (1L << NICE_0_LOAD_SHIFT) 168 169 /* 170 * Single value that decides SCHED_DEADLINE internal math precision. 171 * 10 -> just above 1us 172 * 9 -> just above 0.5us 173 */ 174 #define DL_SCALE 10 175 176 /* 177 * Single value that denotes runtime == period, ie unlimited time. 178 */ 179 #define RUNTIME_INF ((u64)~0ULL) 180 181 static inline int idle_policy(int policy) 182 { 183 return policy == SCHED_IDLE; 184 } 185 static inline int fair_policy(int policy) 186 { 187 return policy == SCHED_NORMAL || policy == SCHED_BATCH; 188 } 189 190 static inline int rt_policy(int policy) 191 { 192 return policy == SCHED_FIFO || policy == SCHED_RR; 193 } 194 195 static inline int dl_policy(int policy) 196 { 197 return policy == SCHED_DEADLINE; 198 } 199 static inline bool valid_policy(int policy) 200 { 201 return idle_policy(policy) || fair_policy(policy) || 202 rt_policy(policy) || dl_policy(policy); 203 } 204 205 static inline int task_has_idle_policy(struct task_struct *p) 206 { 207 return idle_policy(p->policy); 208 } 209 210 static inline int task_has_rt_policy(struct task_struct *p) 211 { 212 return rt_policy(p->policy); 213 } 214 215 static inline int task_has_dl_policy(struct task_struct *p) 216 { 217 return dl_policy(p->policy); 218 } 219 220 #define cap_scale(v, s) ((v)*(s) >> SCHED_CAPACITY_SHIFT) 221 222 static inline void update_avg(u64 *avg, u64 sample) 223 { 224 s64 diff = sample - *avg; 225 *avg += diff / 8; 226 } 227 228 /* 229 * Shifting a value by an exponent greater *or equal* to the size of said value 230 * is UB; cap at size-1. 231 */ 232 #define shr_bound(val, shift) \ 233 (val >> min_t(typeof(shift), shift, BITS_PER_TYPE(typeof(val)) - 1)) 234 235 /* 236 * !! For sched_setattr_nocheck() (kernel) only !! 237 * 238 * This is actually gross. :( 239 * 240 * It is used to make schedutil kworker(s) higher priority than SCHED_DEADLINE 241 * tasks, but still be able to sleep. We need this on platforms that cannot 242 * atomically change clock frequency. Remove once fast switching will be 243 * available on such platforms. 244 * 245 * SUGOV stands for SchedUtil GOVernor. 246 */ 247 #define SCHED_FLAG_SUGOV 0x10000000 248 249 #define SCHED_DL_FLAGS (SCHED_FLAG_RECLAIM | SCHED_FLAG_DL_OVERRUN | SCHED_FLAG_SUGOV) 250 251 static inline bool dl_entity_is_special(const struct sched_dl_entity *dl_se) 252 { 253 #ifdef CONFIG_CPU_FREQ_GOV_SCHEDUTIL 254 return unlikely(dl_se->flags & SCHED_FLAG_SUGOV); 255 #else 256 return false; 257 #endif 258 } 259 260 /* 261 * Tells if entity @a should preempt entity @b. 262 */ 263 static inline bool dl_entity_preempt(const struct sched_dl_entity *a, 264 const struct sched_dl_entity *b) 265 { 266 return dl_entity_is_special(a) || 267 dl_time_before(a->deadline, b->deadline); 268 } 269 270 /* 271 * This is the priority-queue data structure of the RT scheduling class: 272 */ 273 struct rt_prio_array { 274 DECLARE_BITMAP(bitmap, MAX_RT_PRIO+1); /* include 1 bit for delimiter */ 275 struct list_head queue[MAX_RT_PRIO]; 276 }; 277 278 struct rt_bandwidth { 279 /* nests inside the rq lock: */ 280 raw_spinlock_t rt_runtime_lock; 281 ktime_t rt_period; 282 u64 rt_runtime; 283 struct hrtimer rt_period_timer; 284 unsigned int rt_period_active; 285 }; 286 287 void __dl_clear_params(struct task_struct *p); 288 289 struct dl_bandwidth { 290 raw_spinlock_t dl_runtime_lock; 291 u64 dl_runtime; 292 u64 dl_period; 293 }; 294 295 static inline int dl_bandwidth_enabled(void) 296 { 297 return sysctl_sched_rt_runtime >= 0; 298 } 299 300 /* 301 * To keep the bandwidth of -deadline tasks under control 302 * we need some place where: 303 * - store the maximum -deadline bandwidth of each cpu; 304 * - cache the fraction of bandwidth that is currently allocated in 305 * each root domain; 306 * 307 * This is all done in the data structure below. It is similar to the 308 * one used for RT-throttling (rt_bandwidth), with the main difference 309 * that, since here we are only interested in admission control, we 310 * do not decrease any runtime while the group "executes", neither we 311 * need a timer to replenish it. 312 * 313 * With respect to SMP, bandwidth is given on a per root domain basis, 314 * meaning that: 315 * - bw (< 100%) is the deadline bandwidth of each CPU; 316 * - total_bw is the currently allocated bandwidth in each root domain; 317 */ 318 struct dl_bw { 319 raw_spinlock_t lock; 320 u64 bw; 321 u64 total_bw; 322 }; 323 324 extern void init_dl_bw(struct dl_bw *dl_b); 325 extern int sched_dl_global_validate(void); 326 extern void sched_dl_do_global(void); 327 extern int sched_dl_overflow(struct task_struct *p, int policy, const struct sched_attr *attr); 328 extern void __setparam_dl(struct task_struct *p, const struct sched_attr *attr); 329 extern void __getparam_dl(struct task_struct *p, struct sched_attr *attr); 330 extern bool __checkparam_dl(const struct sched_attr *attr); 331 extern bool dl_param_changed(struct task_struct *p, const struct sched_attr *attr); 332 extern int dl_cpuset_cpumask_can_shrink(const struct cpumask *cur, const struct cpumask *trial); 333 extern int dl_cpu_busy(int cpu, struct task_struct *p); 334 335 #ifdef CONFIG_CGROUP_SCHED 336 337 struct cfs_rq; 338 struct rt_rq; 339 340 extern struct list_head task_groups; 341 342 struct cfs_bandwidth { 343 #ifdef CONFIG_CFS_BANDWIDTH 344 raw_spinlock_t lock; 345 ktime_t period; 346 u64 quota; 347 u64 runtime; 348 u64 burst; 349 u64 runtime_snap; 350 s64 hierarchical_quota; 351 352 u8 idle; 353 u8 period_active; 354 u8 slack_started; 355 struct hrtimer period_timer; 356 struct hrtimer slack_timer; 357 struct list_head throttled_cfs_rq; 358 359 /* Statistics: */ 360 int nr_periods; 361 int nr_throttled; 362 int nr_burst; 363 u64 throttled_time; 364 u64 burst_time; 365 #endif 366 }; 367 368 /* Task group related information */ 369 struct task_group { 370 struct cgroup_subsys_state css; 371 372 #ifdef CONFIG_FAIR_GROUP_SCHED 373 /* schedulable entities of this group on each CPU */ 374 struct sched_entity **se; 375 /* runqueue "owned" by this group on each CPU */ 376 struct cfs_rq **cfs_rq; 377 unsigned long shares; 378 379 /* A positive value indicates that this is a SCHED_IDLE group. */ 380 int idle; 381 382 #ifdef CONFIG_SMP 383 /* 384 * load_avg can be heavily contended at clock tick time, so put 385 * it in its own cacheline separated from the fields above which 386 * will also be accessed at each tick. 387 */ 388 atomic_long_t load_avg ____cacheline_aligned; 389 #endif 390 #endif 391 392 #ifdef CONFIG_RT_GROUP_SCHED 393 struct sched_rt_entity **rt_se; 394 struct rt_rq **rt_rq; 395 396 struct rt_bandwidth rt_bandwidth; 397 #endif 398 399 struct rcu_head rcu; 400 struct list_head list; 401 402 struct task_group *parent; 403 struct list_head siblings; 404 struct list_head children; 405 406 #ifdef CONFIG_SCHED_AUTOGROUP 407 struct autogroup *autogroup; 408 #endif 409 410 struct cfs_bandwidth cfs_bandwidth; 411 412 #ifdef CONFIG_UCLAMP_TASK_GROUP 413 /* The two decimal precision [%] value requested from user-space */ 414 unsigned int uclamp_pct[UCLAMP_CNT]; 415 /* Clamp values requested for a task group */ 416 struct uclamp_se uclamp_req[UCLAMP_CNT]; 417 /* Effective clamp values used for a task group */ 418 struct uclamp_se uclamp[UCLAMP_CNT]; 419 #endif 420 421 }; 422 423 #ifdef CONFIG_FAIR_GROUP_SCHED 424 #define ROOT_TASK_GROUP_LOAD NICE_0_LOAD 425 426 /* 427 * A weight of 0 or 1 can cause arithmetics problems. 428 * A weight of a cfs_rq is the sum of weights of which entities 429 * are queued on this cfs_rq, so a weight of a entity should not be 430 * too large, so as the shares value of a task group. 431 * (The default weight is 1024 - so there's no practical 432 * limitation from this.) 433 */ 434 #define MIN_SHARES (1UL << 1) 435 #define MAX_SHARES (1UL << 18) 436 #endif 437 438 typedef int (*tg_visitor)(struct task_group *, void *); 439 440 extern int walk_tg_tree_from(struct task_group *from, 441 tg_visitor down, tg_visitor up, void *data); 442 443 /* 444 * Iterate the full tree, calling @down when first entering a node and @up when 445 * leaving it for the final time. 446 * 447 * Caller must hold rcu_lock or sufficient equivalent. 448 */ 449 static inline int walk_tg_tree(tg_visitor down, tg_visitor up, void *data) 450 { 451 return walk_tg_tree_from(&root_task_group, down, up, data); 452 } 453 454 extern int tg_nop(struct task_group *tg, void *data); 455 456 extern void free_fair_sched_group(struct task_group *tg); 457 extern int alloc_fair_sched_group(struct task_group *tg, struct task_group *parent); 458 extern void online_fair_sched_group(struct task_group *tg); 459 extern void unregister_fair_sched_group(struct task_group *tg); 460 extern void init_tg_cfs_entry(struct task_group *tg, struct cfs_rq *cfs_rq, 461 struct sched_entity *se, int cpu, 462 struct sched_entity *parent); 463 extern void init_cfs_bandwidth(struct cfs_bandwidth *cfs_b); 464 465 extern void __refill_cfs_bandwidth_runtime(struct cfs_bandwidth *cfs_b); 466 extern void start_cfs_bandwidth(struct cfs_bandwidth *cfs_b); 467 extern void unthrottle_cfs_rq(struct cfs_rq *cfs_rq); 468 469 extern void init_tg_rt_entry(struct task_group *tg, struct rt_rq *rt_rq, 470 struct sched_rt_entity *rt_se, int cpu, 471 struct sched_rt_entity *parent); 472 extern int sched_group_set_rt_runtime(struct task_group *tg, long rt_runtime_us); 473 extern int sched_group_set_rt_period(struct task_group *tg, u64 rt_period_us); 474 extern long sched_group_rt_runtime(struct task_group *tg); 475 extern long sched_group_rt_period(struct task_group *tg); 476 extern int sched_rt_can_attach(struct task_group *tg, struct task_struct *tsk); 477 478 extern struct task_group *sched_create_group(struct task_group *parent); 479 extern void sched_online_group(struct task_group *tg, 480 struct task_group *parent); 481 extern void sched_destroy_group(struct task_group *tg); 482 extern void sched_release_group(struct task_group *tg); 483 484 extern void sched_move_task(struct task_struct *tsk); 485 486 #ifdef CONFIG_FAIR_GROUP_SCHED 487 extern int sched_group_set_shares(struct task_group *tg, unsigned long shares); 488 489 extern int sched_group_set_idle(struct task_group *tg, long idle); 490 491 #ifdef CONFIG_SMP 492 extern void set_task_rq_fair(struct sched_entity *se, 493 struct cfs_rq *prev, struct cfs_rq *next); 494 #else /* !CONFIG_SMP */ 495 static inline void set_task_rq_fair(struct sched_entity *se, 496 struct cfs_rq *prev, struct cfs_rq *next) { } 497 #endif /* CONFIG_SMP */ 498 #endif /* CONFIG_FAIR_GROUP_SCHED */ 499 500 #else /* CONFIG_CGROUP_SCHED */ 501 502 struct cfs_bandwidth { }; 503 504 #endif /* CONFIG_CGROUP_SCHED */ 505 506 extern void unregister_rt_sched_group(struct task_group *tg); 507 extern void free_rt_sched_group(struct task_group *tg); 508 extern int alloc_rt_sched_group(struct task_group *tg, struct task_group *parent); 509 510 /* 511 * u64_u32_load/u64_u32_store 512 * 513 * Use a copy of a u64 value to protect against data race. This is only 514 * applicable for 32-bits architectures. 515 */ 516 #ifdef CONFIG_64BIT 517 # define u64_u32_load_copy(var, copy) var 518 # define u64_u32_store_copy(var, copy, val) (var = val) 519 #else 520 # define u64_u32_load_copy(var, copy) \ 521 ({ \ 522 u64 __val, __val_copy; \ 523 do { \ 524 __val_copy = copy; \ 525 /* \ 526 * paired with u64_u32_store_copy(), ordering access \ 527 * to var and copy. \ 528 */ \ 529 smp_rmb(); \ 530 __val = var; \ 531 } while (__val != __val_copy); \ 532 __val; \ 533 }) 534 # define u64_u32_store_copy(var, copy, val) \ 535 do { \ 536 typeof(val) __val = (val); \ 537 var = __val; \ 538 /* \ 539 * paired with u64_u32_load_copy(), ordering access to var and \ 540 * copy. \ 541 */ \ 542 smp_wmb(); \ 543 copy = __val; \ 544 } while (0) 545 #endif 546 # define u64_u32_load(var) u64_u32_load_copy(var, var##_copy) 547 # define u64_u32_store(var, val) u64_u32_store_copy(var, var##_copy, val) 548 549 /* CFS-related fields in a runqueue */ 550 struct cfs_rq { 551 struct load_weight load; 552 unsigned int nr_running; 553 unsigned int h_nr_running; /* SCHED_{NORMAL,BATCH,IDLE} */ 554 unsigned int idle_nr_running; /* SCHED_IDLE */ 555 unsigned int idle_h_nr_running; /* SCHED_IDLE */ 556 557 u64 exec_clock; 558 u64 min_vruntime; 559 #ifdef CONFIG_SCHED_CORE 560 unsigned int forceidle_seq; 561 u64 min_vruntime_fi; 562 #endif 563 564 #ifndef CONFIG_64BIT 565 u64 min_vruntime_copy; 566 #endif 567 568 struct rb_root_cached tasks_timeline; 569 570 /* 571 * 'curr' points to currently running entity on this cfs_rq. 572 * It is set to NULL otherwise (i.e when none are currently running). 573 */ 574 struct sched_entity *curr; 575 struct sched_entity *next; 576 struct sched_entity *last; 577 struct sched_entity *skip; 578 579 #ifdef CONFIG_SCHED_DEBUG 580 unsigned int nr_spread_over; 581 #endif 582 583 #ifdef CONFIG_SMP 584 /* 585 * CFS load tracking 586 */ 587 struct sched_avg avg; 588 #ifndef CONFIG_64BIT 589 u64 last_update_time_copy; 590 #endif 591 struct { 592 raw_spinlock_t lock ____cacheline_aligned; 593 int nr; 594 unsigned long load_avg; 595 unsigned long util_avg; 596 unsigned long runnable_avg; 597 } removed; 598 599 #ifdef CONFIG_FAIR_GROUP_SCHED 600 unsigned long tg_load_avg_contrib; 601 long propagate; 602 long prop_runnable_sum; 603 604 /* 605 * h_load = weight * f(tg) 606 * 607 * Where f(tg) is the recursive weight fraction assigned to 608 * this group. 609 */ 610 unsigned long h_load; 611 u64 last_h_load_update; 612 struct sched_entity *h_load_next; 613 #endif /* CONFIG_FAIR_GROUP_SCHED */ 614 #endif /* CONFIG_SMP */ 615 616 #ifdef CONFIG_FAIR_GROUP_SCHED 617 struct rq *rq; /* CPU runqueue to which this cfs_rq is attached */ 618 619 /* 620 * leaf cfs_rqs are those that hold tasks (lowest schedulable entity in 621 * a hierarchy). Non-leaf lrqs hold other higher schedulable entities 622 * (like users, containers etc.) 623 * 624 * leaf_cfs_rq_list ties together list of leaf cfs_rq's in a CPU. 625 * This list is used during load balance. 626 */ 627 int on_list; 628 struct list_head leaf_cfs_rq_list; 629 struct task_group *tg; /* group that "owns" this runqueue */ 630 631 /* Locally cached copy of our task_group's idle value */ 632 int idle; 633 634 #ifdef CONFIG_CFS_BANDWIDTH 635 int runtime_enabled; 636 s64 runtime_remaining; 637 638 u64 throttled_pelt_idle; 639 #ifndef CONFIG_64BIT 640 u64 throttled_pelt_idle_copy; 641 #endif 642 u64 throttled_clock; 643 u64 throttled_clock_pelt; 644 u64 throttled_clock_pelt_time; 645 int throttled; 646 int throttle_count; 647 struct list_head throttled_list; 648 #ifdef CONFIG_SMP 649 struct list_head throttled_csd_list; 650 #endif 651 #endif /* CONFIG_CFS_BANDWIDTH */ 652 #endif /* CONFIG_FAIR_GROUP_SCHED */ 653 }; 654 655 static inline int rt_bandwidth_enabled(void) 656 { 657 return sysctl_sched_rt_runtime >= 0; 658 } 659 660 /* RT IPI pull logic requires IRQ_WORK */ 661 #if defined(CONFIG_IRQ_WORK) && defined(CONFIG_SMP) 662 # define HAVE_RT_PUSH_IPI 663 #endif 664 665 /* Real-Time classes' related field in a runqueue: */ 666 struct rt_rq { 667 struct rt_prio_array active; 668 unsigned int rt_nr_running; 669 unsigned int rr_nr_running; 670 #if defined CONFIG_SMP || defined CONFIG_RT_GROUP_SCHED 671 struct { 672 int curr; /* highest queued rt task prio */ 673 #ifdef CONFIG_SMP 674 int next; /* next highest */ 675 #endif 676 } highest_prio; 677 #endif 678 #ifdef CONFIG_SMP 679 unsigned int rt_nr_migratory; 680 unsigned int rt_nr_total; 681 int overloaded; 682 struct plist_head pushable_tasks; 683 684 #endif /* CONFIG_SMP */ 685 int rt_queued; 686 687 int rt_throttled; 688 u64 rt_time; 689 u64 rt_runtime; 690 /* Nests inside the rq lock: */ 691 raw_spinlock_t rt_runtime_lock; 692 693 #ifdef CONFIG_RT_GROUP_SCHED 694 unsigned int rt_nr_boosted; 695 696 struct rq *rq; 697 struct task_group *tg; 698 #endif 699 }; 700 701 static inline bool rt_rq_is_runnable(struct rt_rq *rt_rq) 702 { 703 return rt_rq->rt_queued && rt_rq->rt_nr_running; 704 } 705 706 /* Deadline class' related fields in a runqueue */ 707 struct dl_rq { 708 /* runqueue is an rbtree, ordered by deadline */ 709 struct rb_root_cached root; 710 711 unsigned int dl_nr_running; 712 713 #ifdef CONFIG_SMP 714 /* 715 * Deadline values of the currently executing and the 716 * earliest ready task on this rq. Caching these facilitates 717 * the decision whether or not a ready but not running task 718 * should migrate somewhere else. 719 */ 720 struct { 721 u64 curr; 722 u64 next; 723 } earliest_dl; 724 725 unsigned int dl_nr_migratory; 726 int overloaded; 727 728 /* 729 * Tasks on this rq that can be pushed away. They are kept in 730 * an rb-tree, ordered by tasks' deadlines, with caching 731 * of the leftmost (earliest deadline) element. 732 */ 733 struct rb_root_cached pushable_dl_tasks_root; 734 #else 735 struct dl_bw dl_bw; 736 #endif 737 /* 738 * "Active utilization" for this runqueue: increased when a 739 * task wakes up (becomes TASK_RUNNING) and decreased when a 740 * task blocks 741 */ 742 u64 running_bw; 743 744 /* 745 * Utilization of the tasks "assigned" to this runqueue (including 746 * the tasks that are in runqueue and the tasks that executed on this 747 * CPU and blocked). Increased when a task moves to this runqueue, and 748 * decreased when the task moves away (migrates, changes scheduling 749 * policy, or terminates). 750 * This is needed to compute the "inactive utilization" for the 751 * runqueue (inactive utilization = this_bw - running_bw). 752 */ 753 u64 this_bw; 754 u64 extra_bw; 755 756 /* 757 * Inverse of the fraction of CPU utilization that can be reclaimed 758 * by the GRUB algorithm. 759 */ 760 u64 bw_ratio; 761 }; 762 763 #ifdef CONFIG_FAIR_GROUP_SCHED 764 /* An entity is a task if it doesn't "own" a runqueue */ 765 #define entity_is_task(se) (!se->my_q) 766 767 static inline void se_update_runnable(struct sched_entity *se) 768 { 769 if (!entity_is_task(se)) 770 se->runnable_weight = se->my_q->h_nr_running; 771 } 772 773 static inline long se_runnable(struct sched_entity *se) 774 { 775 if (entity_is_task(se)) 776 return !!se->on_rq; 777 else 778 return se->runnable_weight; 779 } 780 781 #else 782 #define entity_is_task(se) 1 783 784 static inline void se_update_runnable(struct sched_entity *se) {} 785 786 static inline long se_runnable(struct sched_entity *se) 787 { 788 return !!se->on_rq; 789 } 790 #endif 791 792 #ifdef CONFIG_SMP 793 /* 794 * XXX we want to get rid of these helpers and use the full load resolution. 795 */ 796 static inline long se_weight(struct sched_entity *se) 797 { 798 return scale_load_down(se->load.weight); 799 } 800 801 802 static inline bool sched_asym_prefer(int a, int b) 803 { 804 return arch_asym_cpu_priority(a) > arch_asym_cpu_priority(b); 805 } 806 807 struct perf_domain { 808 struct em_perf_domain *em_pd; 809 struct perf_domain *next; 810 struct rcu_head rcu; 811 }; 812 813 /* Scheduling group status flags */ 814 #define SG_OVERLOAD 0x1 /* More than one runnable task on a CPU. */ 815 #define SG_OVERUTILIZED 0x2 /* One or more CPUs are over-utilized. */ 816 817 /* 818 * We add the notion of a root-domain which will be used to define per-domain 819 * variables. Each exclusive cpuset essentially defines an island domain by 820 * fully partitioning the member CPUs from any other cpuset. Whenever a new 821 * exclusive cpuset is created, we also create and attach a new root-domain 822 * object. 823 * 824 */ 825 struct root_domain { 826 atomic_t refcount; 827 atomic_t rto_count; 828 struct rcu_head rcu; 829 cpumask_var_t span; 830 cpumask_var_t online; 831 832 /* 833 * Indicate pullable load on at least one CPU, e.g: 834 * - More than one runnable task 835 * - Running task is misfit 836 */ 837 int overload; 838 839 /* Indicate one or more cpus over-utilized (tipping point) */ 840 int overutilized; 841 842 /* 843 * The bit corresponding to a CPU gets set here if such CPU has more 844 * than one runnable -deadline task (as it is below for RT tasks). 845 */ 846 cpumask_var_t dlo_mask; 847 atomic_t dlo_count; 848 struct dl_bw dl_bw; 849 struct cpudl cpudl; 850 851 /* 852 * Indicate whether a root_domain's dl_bw has been checked or 853 * updated. It's monotonously increasing value. 854 * 855 * Also, some corner cases, like 'wrap around' is dangerous, but given 856 * that u64 is 'big enough'. So that shouldn't be a concern. 857 */ 858 u64 visit_gen; 859 860 #ifdef HAVE_RT_PUSH_IPI 861 /* 862 * For IPI pull requests, loop across the rto_mask. 863 */ 864 struct irq_work rto_push_work; 865 raw_spinlock_t rto_lock; 866 /* These are only updated and read within rto_lock */ 867 int rto_loop; 868 int rto_cpu; 869 /* These atomics are updated outside of a lock */ 870 atomic_t rto_loop_next; 871 atomic_t rto_loop_start; 872 #endif 873 /* 874 * The "RT overload" flag: it gets set if a CPU has more than 875 * one runnable RT task. 876 */ 877 cpumask_var_t rto_mask; 878 struct cpupri cpupri; 879 880 unsigned long max_cpu_capacity; 881 882 /* 883 * NULL-terminated list of performance domains intersecting with the 884 * CPUs of the rd. Protected by RCU. 885 */ 886 struct perf_domain __rcu *pd; 887 }; 888 889 extern void init_defrootdomain(void); 890 extern int sched_init_domains(const struct cpumask *cpu_map); 891 extern void rq_attach_root(struct rq *rq, struct root_domain *rd); 892 extern void sched_get_rd(struct root_domain *rd); 893 extern void sched_put_rd(struct root_domain *rd); 894 895 #ifdef HAVE_RT_PUSH_IPI 896 extern void rto_push_irq_work_func(struct irq_work *work); 897 #endif 898 #endif /* CONFIG_SMP */ 899 900 #ifdef CONFIG_UCLAMP_TASK 901 /* 902 * struct uclamp_bucket - Utilization clamp bucket 903 * @value: utilization clamp value for tasks on this clamp bucket 904 * @tasks: number of RUNNABLE tasks on this clamp bucket 905 * 906 * Keep track of how many tasks are RUNNABLE for a given utilization 907 * clamp value. 908 */ 909 struct uclamp_bucket { 910 unsigned long value : bits_per(SCHED_CAPACITY_SCALE); 911 unsigned long tasks : BITS_PER_LONG - bits_per(SCHED_CAPACITY_SCALE); 912 }; 913 914 /* 915 * struct uclamp_rq - rq's utilization clamp 916 * @value: currently active clamp values for a rq 917 * @bucket: utilization clamp buckets affecting a rq 918 * 919 * Keep track of RUNNABLE tasks on a rq to aggregate their clamp values. 920 * A clamp value is affecting a rq when there is at least one task RUNNABLE 921 * (or actually running) with that value. 922 * 923 * There are up to UCLAMP_CNT possible different clamp values, currently there 924 * are only two: minimum utilization and maximum utilization. 925 * 926 * All utilization clamping values are MAX aggregated, since: 927 * - for util_min: we want to run the CPU at least at the max of the minimum 928 * utilization required by its currently RUNNABLE tasks. 929 * - for util_max: we want to allow the CPU to run up to the max of the 930 * maximum utilization allowed by its currently RUNNABLE tasks. 931 * 932 * Since on each system we expect only a limited number of different 933 * utilization clamp values (UCLAMP_BUCKETS), use a simple array to track 934 * the metrics required to compute all the per-rq utilization clamp values. 935 */ 936 struct uclamp_rq { 937 unsigned int value; 938 struct uclamp_bucket bucket[UCLAMP_BUCKETS]; 939 }; 940 941 DECLARE_STATIC_KEY_FALSE(sched_uclamp_used); 942 #endif /* CONFIG_UCLAMP_TASK */ 943 944 struct rq; 945 struct balance_callback { 946 struct balance_callback *next; 947 void (*func)(struct rq *rq); 948 }; 949 950 /* 951 * This is the main, per-CPU runqueue data structure. 952 * 953 * Locking rule: those places that want to lock multiple runqueues 954 * (such as the load balancing or the thread migration code), lock 955 * acquire operations must be ordered by ascending &runqueue. 956 */ 957 struct rq { 958 /* runqueue lock: */ 959 raw_spinlock_t __lock; 960 961 /* 962 * nr_running and cpu_load should be in the same cacheline because 963 * remote CPUs use both these fields when doing load calculation. 964 */ 965 unsigned int nr_running; 966 #ifdef CONFIG_NUMA_BALANCING 967 unsigned int nr_numa_running; 968 unsigned int nr_preferred_running; 969 unsigned int numa_migrate_on; 970 #endif 971 #ifdef CONFIG_NO_HZ_COMMON 972 #ifdef CONFIG_SMP 973 unsigned long last_blocked_load_update_tick; 974 unsigned int has_blocked_load; 975 call_single_data_t nohz_csd; 976 #endif /* CONFIG_SMP */ 977 unsigned int nohz_tick_stopped; 978 atomic_t nohz_flags; 979 #endif /* CONFIG_NO_HZ_COMMON */ 980 981 #ifdef CONFIG_SMP 982 unsigned int ttwu_pending; 983 #endif 984 u64 nr_switches; 985 986 #ifdef CONFIG_UCLAMP_TASK 987 /* Utilization clamp values based on CPU's RUNNABLE tasks */ 988 struct uclamp_rq uclamp[UCLAMP_CNT] ____cacheline_aligned; 989 unsigned int uclamp_flags; 990 #define UCLAMP_FLAG_IDLE 0x01 991 #endif 992 993 struct cfs_rq cfs; 994 struct rt_rq rt; 995 struct dl_rq dl; 996 997 #ifdef CONFIG_FAIR_GROUP_SCHED 998 /* list of leaf cfs_rq on this CPU: */ 999 struct list_head leaf_cfs_rq_list; 1000 struct list_head *tmp_alone_branch; 1001 #endif /* CONFIG_FAIR_GROUP_SCHED */ 1002 1003 /* 1004 * This is part of a global counter where only the total sum 1005 * over all CPUs matters. A task can increase this counter on 1006 * one CPU and if it got migrated afterwards it may decrease 1007 * it on another CPU. Always updated under the runqueue lock: 1008 */ 1009 unsigned int nr_uninterruptible; 1010 1011 struct task_struct __rcu *curr; 1012 struct task_struct *idle; 1013 struct task_struct *stop; 1014 unsigned long next_balance; 1015 struct mm_struct *prev_mm; 1016 1017 unsigned int clock_update_flags; 1018 u64 clock; 1019 /* Ensure that all clocks are in the same cache line */ 1020 u64 clock_task ____cacheline_aligned; 1021 u64 clock_pelt; 1022 unsigned long lost_idle_time; 1023 u64 clock_pelt_idle; 1024 u64 clock_idle; 1025 #ifndef CONFIG_64BIT 1026 u64 clock_pelt_idle_copy; 1027 u64 clock_idle_copy; 1028 #endif 1029 1030 atomic_t nr_iowait; 1031 1032 #ifdef CONFIG_SCHED_DEBUG 1033 u64 last_seen_need_resched_ns; 1034 int ticks_without_resched; 1035 #endif 1036 1037 #ifdef CONFIG_MEMBARRIER 1038 int membarrier_state; 1039 #endif 1040 1041 #ifdef CONFIG_SMP 1042 struct root_domain *rd; 1043 struct sched_domain __rcu *sd; 1044 1045 unsigned long cpu_capacity; 1046 unsigned long cpu_capacity_orig; 1047 1048 struct balance_callback *balance_callback; 1049 1050 unsigned char nohz_idle_balance; 1051 unsigned char idle_balance; 1052 1053 unsigned long misfit_task_load; 1054 1055 /* For active balancing */ 1056 int active_balance; 1057 int push_cpu; 1058 struct cpu_stop_work active_balance_work; 1059 1060 /* CPU of this runqueue: */ 1061 int cpu; 1062 int online; 1063 1064 struct list_head cfs_tasks; 1065 1066 struct sched_avg avg_rt; 1067 struct sched_avg avg_dl; 1068 #ifdef CONFIG_HAVE_SCHED_AVG_IRQ 1069 struct sched_avg avg_irq; 1070 #endif 1071 #ifdef CONFIG_SCHED_THERMAL_PRESSURE 1072 struct sched_avg avg_thermal; 1073 #endif 1074 u64 idle_stamp; 1075 u64 avg_idle; 1076 1077 unsigned long wake_stamp; 1078 u64 wake_avg_idle; 1079 1080 /* This is used to determine avg_idle's max value */ 1081 u64 max_idle_balance_cost; 1082 1083 #ifdef CONFIG_HOTPLUG_CPU 1084 struct rcuwait hotplug_wait; 1085 #endif 1086 #endif /* CONFIG_SMP */ 1087 1088 #ifdef CONFIG_IRQ_TIME_ACCOUNTING 1089 u64 prev_irq_time; 1090 #endif 1091 #ifdef CONFIG_PARAVIRT 1092 u64 prev_steal_time; 1093 #endif 1094 #ifdef CONFIG_PARAVIRT_TIME_ACCOUNTING 1095 u64 prev_steal_time_rq; 1096 #endif 1097 1098 /* calc_load related fields */ 1099 unsigned long calc_load_update; 1100 long calc_load_active; 1101 1102 #ifdef CONFIG_SCHED_HRTICK 1103 #ifdef CONFIG_SMP 1104 call_single_data_t hrtick_csd; 1105 #endif 1106 struct hrtimer hrtick_timer; 1107 ktime_t hrtick_time; 1108 #endif 1109 1110 #ifdef CONFIG_SCHEDSTATS 1111 /* latency stats */ 1112 struct sched_info rq_sched_info; 1113 unsigned long long rq_cpu_time; 1114 /* could above be rq->cfs_rq.exec_clock + rq->rt_rq.rt_runtime ? */ 1115 1116 /* sys_sched_yield() stats */ 1117 unsigned int yld_count; 1118 1119 /* schedule() stats */ 1120 unsigned int sched_count; 1121 unsigned int sched_goidle; 1122 1123 /* try_to_wake_up() stats */ 1124 unsigned int ttwu_count; 1125 unsigned int ttwu_local; 1126 #endif 1127 1128 #ifdef CONFIG_CPU_IDLE 1129 /* Must be inspected within a rcu lock section */ 1130 struct cpuidle_state *idle_state; 1131 #endif 1132 1133 #ifdef CONFIG_SMP 1134 unsigned int nr_pinned; 1135 #endif 1136 unsigned int push_busy; 1137 struct cpu_stop_work push_work; 1138 1139 #ifdef CONFIG_SCHED_CORE 1140 /* per rq */ 1141 struct rq *core; 1142 struct task_struct *core_pick; 1143 unsigned int core_enabled; 1144 unsigned int core_sched_seq; 1145 struct rb_root core_tree; 1146 1147 /* shared state -- careful with sched_core_cpu_deactivate() */ 1148 unsigned int core_task_seq; 1149 unsigned int core_pick_seq; 1150 unsigned long core_cookie; 1151 unsigned int core_forceidle_count; 1152 unsigned int core_forceidle_seq; 1153 unsigned int core_forceidle_occupation; 1154 u64 core_forceidle_start; 1155 #endif 1156 1157 /* Scratch cpumask to be temporarily used under rq_lock */ 1158 cpumask_var_t scratch_mask; 1159 1160 #if defined(CONFIG_CFS_BANDWIDTH) && defined(CONFIG_SMP) 1161 call_single_data_t cfsb_csd; 1162 struct list_head cfsb_csd_list; 1163 #endif 1164 }; 1165 1166 #ifdef CONFIG_FAIR_GROUP_SCHED 1167 1168 /* CPU runqueue to which this cfs_rq is attached */ 1169 static inline struct rq *rq_of(struct cfs_rq *cfs_rq) 1170 { 1171 return cfs_rq->rq; 1172 } 1173 1174 #else 1175 1176 static inline struct rq *rq_of(struct cfs_rq *cfs_rq) 1177 { 1178 return container_of(cfs_rq, struct rq, cfs); 1179 } 1180 #endif 1181 1182 static inline int cpu_of(struct rq *rq) 1183 { 1184 #ifdef CONFIG_SMP 1185 return rq->cpu; 1186 #else 1187 return 0; 1188 #endif 1189 } 1190 1191 #define MDF_PUSH 0x01 1192 1193 static inline bool is_migration_disabled(struct task_struct *p) 1194 { 1195 #ifdef CONFIG_SMP 1196 return p->migration_disabled; 1197 #else 1198 return false; 1199 #endif 1200 } 1201 1202 DECLARE_PER_CPU_SHARED_ALIGNED(struct rq, runqueues); 1203 1204 #define cpu_rq(cpu) (&per_cpu(runqueues, (cpu))) 1205 #define this_rq() this_cpu_ptr(&runqueues) 1206 #define task_rq(p) cpu_rq(task_cpu(p)) 1207 #define cpu_curr(cpu) (cpu_rq(cpu)->curr) 1208 #define raw_rq() raw_cpu_ptr(&runqueues) 1209 1210 struct sched_group; 1211 #ifdef CONFIG_SCHED_CORE 1212 static inline struct cpumask *sched_group_span(struct sched_group *sg); 1213 1214 DECLARE_STATIC_KEY_FALSE(__sched_core_enabled); 1215 1216 static inline bool sched_core_enabled(struct rq *rq) 1217 { 1218 return static_branch_unlikely(&__sched_core_enabled) && rq->core_enabled; 1219 } 1220 1221 static inline bool sched_core_disabled(void) 1222 { 1223 return !static_branch_unlikely(&__sched_core_enabled); 1224 } 1225 1226 /* 1227 * Be careful with this function; not for general use. The return value isn't 1228 * stable unless you actually hold a relevant rq->__lock. 1229 */ 1230 static inline raw_spinlock_t *rq_lockp(struct rq *rq) 1231 { 1232 if (sched_core_enabled(rq)) 1233 return &rq->core->__lock; 1234 1235 return &rq->__lock; 1236 } 1237 1238 static inline raw_spinlock_t *__rq_lockp(struct rq *rq) 1239 { 1240 if (rq->core_enabled) 1241 return &rq->core->__lock; 1242 1243 return &rq->__lock; 1244 } 1245 1246 bool cfs_prio_less(const struct task_struct *a, const struct task_struct *b, 1247 bool fi); 1248 1249 /* 1250 * Helpers to check if the CPU's core cookie matches with the task's cookie 1251 * when core scheduling is enabled. 1252 * A special case is that the task's cookie always matches with CPU's core 1253 * cookie if the CPU is in an idle core. 1254 */ 1255 static inline bool sched_cpu_cookie_match(struct rq *rq, struct task_struct *p) 1256 { 1257 /* Ignore cookie match if core scheduler is not enabled on the CPU. */ 1258 if (!sched_core_enabled(rq)) 1259 return true; 1260 1261 return rq->core->core_cookie == p->core_cookie; 1262 } 1263 1264 static inline bool sched_core_cookie_match(struct rq *rq, struct task_struct *p) 1265 { 1266 bool idle_core = true; 1267 int cpu; 1268 1269 /* Ignore cookie match if core scheduler is not enabled on the CPU. */ 1270 if (!sched_core_enabled(rq)) 1271 return true; 1272 1273 for_each_cpu(cpu, cpu_smt_mask(cpu_of(rq))) { 1274 if (!available_idle_cpu(cpu)) { 1275 idle_core = false; 1276 break; 1277 } 1278 } 1279 1280 /* 1281 * A CPU in an idle core is always the best choice for tasks with 1282 * cookies. 1283 */ 1284 return idle_core || rq->core->core_cookie == p->core_cookie; 1285 } 1286 1287 static inline bool sched_group_cookie_match(struct rq *rq, 1288 struct task_struct *p, 1289 struct sched_group *group) 1290 { 1291 int cpu; 1292 1293 /* Ignore cookie match if core scheduler is not enabled on the CPU. */ 1294 if (!sched_core_enabled(rq)) 1295 return true; 1296 1297 for_each_cpu_and(cpu, sched_group_span(group), p->cpus_ptr) { 1298 if (sched_core_cookie_match(cpu_rq(cpu), p)) 1299 return true; 1300 } 1301 return false; 1302 } 1303 1304 static inline bool sched_core_enqueued(struct task_struct *p) 1305 { 1306 return !RB_EMPTY_NODE(&p->core_node); 1307 } 1308 1309 extern void sched_core_enqueue(struct rq *rq, struct task_struct *p); 1310 extern void sched_core_dequeue(struct rq *rq, struct task_struct *p, int flags); 1311 1312 extern void sched_core_get(void); 1313 extern void sched_core_put(void); 1314 1315 #else /* !CONFIG_SCHED_CORE */ 1316 1317 static inline bool sched_core_enabled(struct rq *rq) 1318 { 1319 return false; 1320 } 1321 1322 static inline bool sched_core_disabled(void) 1323 { 1324 return true; 1325 } 1326 1327 static inline raw_spinlock_t *rq_lockp(struct rq *rq) 1328 { 1329 return &rq->__lock; 1330 } 1331 1332 static inline raw_spinlock_t *__rq_lockp(struct rq *rq) 1333 { 1334 return &rq->__lock; 1335 } 1336 1337 static inline bool sched_cpu_cookie_match(struct rq *rq, struct task_struct *p) 1338 { 1339 return true; 1340 } 1341 1342 static inline bool sched_core_cookie_match(struct rq *rq, struct task_struct *p) 1343 { 1344 return true; 1345 } 1346 1347 static inline bool sched_group_cookie_match(struct rq *rq, 1348 struct task_struct *p, 1349 struct sched_group *group) 1350 { 1351 return true; 1352 } 1353 #endif /* CONFIG_SCHED_CORE */ 1354 1355 static inline void lockdep_assert_rq_held(struct rq *rq) 1356 { 1357 lockdep_assert_held(__rq_lockp(rq)); 1358 } 1359 1360 extern void raw_spin_rq_lock_nested(struct rq *rq, int subclass); 1361 extern bool raw_spin_rq_trylock(struct rq *rq); 1362 extern void raw_spin_rq_unlock(struct rq *rq); 1363 1364 static inline void raw_spin_rq_lock(struct rq *rq) 1365 { 1366 raw_spin_rq_lock_nested(rq, 0); 1367 } 1368 1369 static inline void raw_spin_rq_lock_irq(struct rq *rq) 1370 { 1371 local_irq_disable(); 1372 raw_spin_rq_lock(rq); 1373 } 1374 1375 static inline void raw_spin_rq_unlock_irq(struct rq *rq) 1376 { 1377 raw_spin_rq_unlock(rq); 1378 local_irq_enable(); 1379 } 1380 1381 static inline unsigned long _raw_spin_rq_lock_irqsave(struct rq *rq) 1382 { 1383 unsigned long flags; 1384 local_irq_save(flags); 1385 raw_spin_rq_lock(rq); 1386 return flags; 1387 } 1388 1389 static inline void raw_spin_rq_unlock_irqrestore(struct rq *rq, unsigned long flags) 1390 { 1391 raw_spin_rq_unlock(rq); 1392 local_irq_restore(flags); 1393 } 1394 1395 #define raw_spin_rq_lock_irqsave(rq, flags) \ 1396 do { \ 1397 flags = _raw_spin_rq_lock_irqsave(rq); \ 1398 } while (0) 1399 1400 #ifdef CONFIG_SCHED_SMT 1401 extern void __update_idle_core(struct rq *rq); 1402 1403 static inline void update_idle_core(struct rq *rq) 1404 { 1405 if (static_branch_unlikely(&sched_smt_present)) 1406 __update_idle_core(rq); 1407 } 1408 1409 #else 1410 static inline void update_idle_core(struct rq *rq) { } 1411 #endif 1412 1413 #ifdef CONFIG_FAIR_GROUP_SCHED 1414 static inline struct task_struct *task_of(struct sched_entity *se) 1415 { 1416 SCHED_WARN_ON(!entity_is_task(se)); 1417 return container_of(se, struct task_struct, se); 1418 } 1419 1420 static inline struct cfs_rq *task_cfs_rq(struct task_struct *p) 1421 { 1422 return p->se.cfs_rq; 1423 } 1424 1425 /* runqueue on which this entity is (to be) queued */ 1426 static inline struct cfs_rq *cfs_rq_of(const struct sched_entity *se) 1427 { 1428 return se->cfs_rq; 1429 } 1430 1431 /* runqueue "owned" by this group */ 1432 static inline struct cfs_rq *group_cfs_rq(struct sched_entity *grp) 1433 { 1434 return grp->my_q; 1435 } 1436 1437 #else 1438 1439 #define task_of(_se) container_of(_se, struct task_struct, se) 1440 1441 static inline struct cfs_rq *task_cfs_rq(const struct task_struct *p) 1442 { 1443 return &task_rq(p)->cfs; 1444 } 1445 1446 static inline struct cfs_rq *cfs_rq_of(const struct sched_entity *se) 1447 { 1448 const struct task_struct *p = task_of(se); 1449 struct rq *rq = task_rq(p); 1450 1451 return &rq->cfs; 1452 } 1453 1454 /* runqueue "owned" by this group */ 1455 static inline struct cfs_rq *group_cfs_rq(struct sched_entity *grp) 1456 { 1457 return NULL; 1458 } 1459 #endif 1460 1461 extern void update_rq_clock(struct rq *rq); 1462 1463 /* 1464 * rq::clock_update_flags bits 1465 * 1466 * %RQCF_REQ_SKIP - will request skipping of clock update on the next 1467 * call to __schedule(). This is an optimisation to avoid 1468 * neighbouring rq clock updates. 1469 * 1470 * %RQCF_ACT_SKIP - is set from inside of __schedule() when skipping is 1471 * in effect and calls to update_rq_clock() are being ignored. 1472 * 1473 * %RQCF_UPDATED - is a debug flag that indicates whether a call has been 1474 * made to update_rq_clock() since the last time rq::lock was pinned. 1475 * 1476 * If inside of __schedule(), clock_update_flags will have been 1477 * shifted left (a left shift is a cheap operation for the fast path 1478 * to promote %RQCF_REQ_SKIP to %RQCF_ACT_SKIP), so you must use, 1479 * 1480 * if (rq-clock_update_flags >= RQCF_UPDATED) 1481 * 1482 * to check if %RQCF_UPDATED is set. It'll never be shifted more than 1483 * one position though, because the next rq_unpin_lock() will shift it 1484 * back. 1485 */ 1486 #define RQCF_REQ_SKIP 0x01 1487 #define RQCF_ACT_SKIP 0x02 1488 #define RQCF_UPDATED 0x04 1489 1490 static inline void assert_clock_updated(struct rq *rq) 1491 { 1492 /* 1493 * The only reason for not seeing a clock update since the 1494 * last rq_pin_lock() is if we're currently skipping updates. 1495 */ 1496 SCHED_WARN_ON(rq->clock_update_flags < RQCF_ACT_SKIP); 1497 } 1498 1499 static inline u64 rq_clock(struct rq *rq) 1500 { 1501 lockdep_assert_rq_held(rq); 1502 assert_clock_updated(rq); 1503 1504 return rq->clock; 1505 } 1506 1507 static inline u64 rq_clock_task(struct rq *rq) 1508 { 1509 lockdep_assert_rq_held(rq); 1510 assert_clock_updated(rq); 1511 1512 return rq->clock_task; 1513 } 1514 1515 /** 1516 * By default the decay is the default pelt decay period. 1517 * The decay shift can change the decay period in 1518 * multiples of 32. 1519 * Decay shift Decay period(ms) 1520 * 0 32 1521 * 1 64 1522 * 2 128 1523 * 3 256 1524 * 4 512 1525 */ 1526 extern int sched_thermal_decay_shift; 1527 1528 static inline u64 rq_clock_thermal(struct rq *rq) 1529 { 1530 return rq_clock_task(rq) >> sched_thermal_decay_shift; 1531 } 1532 1533 static inline void rq_clock_skip_update(struct rq *rq) 1534 { 1535 lockdep_assert_rq_held(rq); 1536 rq->clock_update_flags |= RQCF_REQ_SKIP; 1537 } 1538 1539 /* 1540 * See rt task throttling, which is the only time a skip 1541 * request is canceled. 1542 */ 1543 static inline void rq_clock_cancel_skipupdate(struct rq *rq) 1544 { 1545 lockdep_assert_rq_held(rq); 1546 rq->clock_update_flags &= ~RQCF_REQ_SKIP; 1547 } 1548 1549 struct rq_flags { 1550 unsigned long flags; 1551 struct pin_cookie cookie; 1552 #ifdef CONFIG_SCHED_DEBUG 1553 /* 1554 * A copy of (rq::clock_update_flags & RQCF_UPDATED) for the 1555 * current pin context is stashed here in case it needs to be 1556 * restored in rq_repin_lock(). 1557 */ 1558 unsigned int clock_update_flags; 1559 #endif 1560 }; 1561 1562 extern struct balance_callback balance_push_callback; 1563 1564 /* 1565 * Lockdep annotation that avoids accidental unlocks; it's like a 1566 * sticky/continuous lockdep_assert_held(). 1567 * 1568 * This avoids code that has access to 'struct rq *rq' (basically everything in 1569 * the scheduler) from accidentally unlocking the rq if they do not also have a 1570 * copy of the (on-stack) 'struct rq_flags rf'. 1571 * 1572 * Also see Documentation/locking/lockdep-design.rst. 1573 */ 1574 static inline void rq_pin_lock(struct rq *rq, struct rq_flags *rf) 1575 { 1576 rf->cookie = lockdep_pin_lock(__rq_lockp(rq)); 1577 1578 #ifdef CONFIG_SCHED_DEBUG 1579 rq->clock_update_flags &= (RQCF_REQ_SKIP|RQCF_ACT_SKIP); 1580 rf->clock_update_flags = 0; 1581 #ifdef CONFIG_SMP 1582 SCHED_WARN_ON(rq->balance_callback && rq->balance_callback != &balance_push_callback); 1583 #endif 1584 #endif 1585 } 1586 1587 static inline void rq_unpin_lock(struct rq *rq, struct rq_flags *rf) 1588 { 1589 #ifdef CONFIG_SCHED_DEBUG 1590 if (rq->clock_update_flags > RQCF_ACT_SKIP) 1591 rf->clock_update_flags = RQCF_UPDATED; 1592 #endif 1593 1594 lockdep_unpin_lock(__rq_lockp(rq), rf->cookie); 1595 } 1596 1597 static inline void rq_repin_lock(struct rq *rq, struct rq_flags *rf) 1598 { 1599 lockdep_repin_lock(__rq_lockp(rq), rf->cookie); 1600 1601 #ifdef CONFIG_SCHED_DEBUG 1602 /* 1603 * Restore the value we stashed in @rf for this pin context. 1604 */ 1605 rq->clock_update_flags |= rf->clock_update_flags; 1606 #endif 1607 } 1608 1609 struct rq *__task_rq_lock(struct task_struct *p, struct rq_flags *rf) 1610 __acquires(rq->lock); 1611 1612 struct rq *task_rq_lock(struct task_struct *p, struct rq_flags *rf) 1613 __acquires(p->pi_lock) 1614 __acquires(rq->lock); 1615 1616 static inline void __task_rq_unlock(struct rq *rq, struct rq_flags *rf) 1617 __releases(rq->lock) 1618 { 1619 rq_unpin_lock(rq, rf); 1620 raw_spin_rq_unlock(rq); 1621 } 1622 1623 static inline void 1624 task_rq_unlock(struct rq *rq, struct task_struct *p, struct rq_flags *rf) 1625 __releases(rq->lock) 1626 __releases(p->pi_lock) 1627 { 1628 rq_unpin_lock(rq, rf); 1629 raw_spin_rq_unlock(rq); 1630 raw_spin_unlock_irqrestore(&p->pi_lock, rf->flags); 1631 } 1632 1633 static inline void 1634 rq_lock_irqsave(struct rq *rq, struct rq_flags *rf) 1635 __acquires(rq->lock) 1636 { 1637 raw_spin_rq_lock_irqsave(rq, rf->flags); 1638 rq_pin_lock(rq, rf); 1639 } 1640 1641 static inline void 1642 rq_lock_irq(struct rq *rq, struct rq_flags *rf) 1643 __acquires(rq->lock) 1644 { 1645 raw_spin_rq_lock_irq(rq); 1646 rq_pin_lock(rq, rf); 1647 } 1648 1649 static inline void 1650 rq_lock(struct rq *rq, struct rq_flags *rf) 1651 __acquires(rq->lock) 1652 { 1653 raw_spin_rq_lock(rq); 1654 rq_pin_lock(rq, rf); 1655 } 1656 1657 static inline void 1658 rq_unlock_irqrestore(struct rq *rq, struct rq_flags *rf) 1659 __releases(rq->lock) 1660 { 1661 rq_unpin_lock(rq, rf); 1662 raw_spin_rq_unlock_irqrestore(rq, rf->flags); 1663 } 1664 1665 static inline void 1666 rq_unlock_irq(struct rq *rq, struct rq_flags *rf) 1667 __releases(rq->lock) 1668 { 1669 rq_unpin_lock(rq, rf); 1670 raw_spin_rq_unlock_irq(rq); 1671 } 1672 1673 static inline void 1674 rq_unlock(struct rq *rq, struct rq_flags *rf) 1675 __releases(rq->lock) 1676 { 1677 rq_unpin_lock(rq, rf); 1678 raw_spin_rq_unlock(rq); 1679 } 1680 1681 static inline struct rq * 1682 this_rq_lock_irq(struct rq_flags *rf) 1683 __acquires(rq->lock) 1684 { 1685 struct rq *rq; 1686 1687 local_irq_disable(); 1688 rq = this_rq(); 1689 rq_lock(rq, rf); 1690 return rq; 1691 } 1692 1693 #ifdef CONFIG_NUMA 1694 enum numa_topology_type { 1695 NUMA_DIRECT, 1696 NUMA_GLUELESS_MESH, 1697 NUMA_BACKPLANE, 1698 }; 1699 extern enum numa_topology_type sched_numa_topology_type; 1700 extern int sched_max_numa_distance; 1701 extern bool find_numa_distance(int distance); 1702 extern void sched_init_numa(int offline_node); 1703 extern void sched_update_numa(int cpu, bool online); 1704 extern void sched_domains_numa_masks_set(unsigned int cpu); 1705 extern void sched_domains_numa_masks_clear(unsigned int cpu); 1706 extern int sched_numa_find_closest(const struct cpumask *cpus, int cpu); 1707 #else 1708 static inline void sched_init_numa(int offline_node) { } 1709 static inline void sched_update_numa(int cpu, bool online) { } 1710 static inline void sched_domains_numa_masks_set(unsigned int cpu) { } 1711 static inline void sched_domains_numa_masks_clear(unsigned int cpu) { } 1712 static inline int sched_numa_find_closest(const struct cpumask *cpus, int cpu) 1713 { 1714 return nr_cpu_ids; 1715 } 1716 #endif 1717 1718 #ifdef CONFIG_NUMA_BALANCING 1719 /* The regions in numa_faults array from task_struct */ 1720 enum numa_faults_stats { 1721 NUMA_MEM = 0, 1722 NUMA_CPU, 1723 NUMA_MEMBUF, 1724 NUMA_CPUBUF 1725 }; 1726 extern void sched_setnuma(struct task_struct *p, int node); 1727 extern int migrate_task_to(struct task_struct *p, int cpu); 1728 extern int migrate_swap(struct task_struct *p, struct task_struct *t, 1729 int cpu, int scpu); 1730 extern void init_numa_balancing(unsigned long clone_flags, struct task_struct *p); 1731 #else 1732 static inline void 1733 init_numa_balancing(unsigned long clone_flags, struct task_struct *p) 1734 { 1735 } 1736 #endif /* CONFIG_NUMA_BALANCING */ 1737 1738 #ifdef CONFIG_SMP 1739 1740 static inline void 1741 queue_balance_callback(struct rq *rq, 1742 struct balance_callback *head, 1743 void (*func)(struct rq *rq)) 1744 { 1745 lockdep_assert_rq_held(rq); 1746 1747 /* 1748 * Don't (re)queue an already queued item; nor queue anything when 1749 * balance_push() is active, see the comment with 1750 * balance_push_callback. 1751 */ 1752 if (unlikely(head->next || rq->balance_callback == &balance_push_callback)) 1753 return; 1754 1755 head->func = func; 1756 head->next = rq->balance_callback; 1757 rq->balance_callback = head; 1758 } 1759 1760 #define rcu_dereference_check_sched_domain(p) \ 1761 rcu_dereference_check((p), \ 1762 lockdep_is_held(&sched_domains_mutex)) 1763 1764 /* 1765 * The domain tree (rq->sd) is protected by RCU's quiescent state transition. 1766 * See destroy_sched_domains: call_rcu for details. 1767 * 1768 * The domain tree of any CPU may only be accessed from within 1769 * preempt-disabled sections. 1770 */ 1771 #define for_each_domain(cpu, __sd) \ 1772 for (__sd = rcu_dereference_check_sched_domain(cpu_rq(cpu)->sd); \ 1773 __sd; __sd = __sd->parent) 1774 1775 /** 1776 * highest_flag_domain - Return highest sched_domain containing flag. 1777 * @cpu: The CPU whose highest level of sched domain is to 1778 * be returned. 1779 * @flag: The flag to check for the highest sched_domain 1780 * for the given CPU. 1781 * 1782 * Returns the highest sched_domain of a CPU which contains the given flag. 1783 */ 1784 static inline struct sched_domain *highest_flag_domain(int cpu, int flag) 1785 { 1786 struct sched_domain *sd, *hsd = NULL; 1787 1788 for_each_domain(cpu, sd) { 1789 if (!(sd->flags & flag)) 1790 break; 1791 hsd = sd; 1792 } 1793 1794 return hsd; 1795 } 1796 1797 static inline struct sched_domain *lowest_flag_domain(int cpu, int flag) 1798 { 1799 struct sched_domain *sd; 1800 1801 for_each_domain(cpu, sd) { 1802 if (sd->flags & flag) 1803 break; 1804 } 1805 1806 return sd; 1807 } 1808 1809 DECLARE_PER_CPU(struct sched_domain __rcu *, sd_llc); 1810 DECLARE_PER_CPU(int, sd_llc_size); 1811 DECLARE_PER_CPU(int, sd_llc_id); 1812 DECLARE_PER_CPU(struct sched_domain_shared __rcu *, sd_llc_shared); 1813 DECLARE_PER_CPU(struct sched_domain __rcu *, sd_numa); 1814 DECLARE_PER_CPU(struct sched_domain __rcu *, sd_asym_packing); 1815 DECLARE_PER_CPU(struct sched_domain __rcu *, sd_asym_cpucapacity); 1816 extern struct static_key_false sched_asym_cpucapacity; 1817 1818 static __always_inline bool sched_asym_cpucap_active(void) 1819 { 1820 return static_branch_unlikely(&sched_asym_cpucapacity); 1821 } 1822 1823 struct sched_group_capacity { 1824 atomic_t ref; 1825 /* 1826 * CPU capacity of this group, SCHED_CAPACITY_SCALE being max capacity 1827 * for a single CPU. 1828 */ 1829 unsigned long capacity; 1830 unsigned long min_capacity; /* Min per-CPU capacity in group */ 1831 unsigned long max_capacity; /* Max per-CPU capacity in group */ 1832 unsigned long next_update; 1833 int imbalance; /* XXX unrelated to capacity but shared group state */ 1834 1835 #ifdef CONFIG_SCHED_DEBUG 1836 int id; 1837 #endif 1838 1839 unsigned long cpumask[]; /* Balance mask */ 1840 }; 1841 1842 struct sched_group { 1843 struct sched_group *next; /* Must be a circular list */ 1844 atomic_t ref; 1845 1846 unsigned int group_weight; 1847 struct sched_group_capacity *sgc; 1848 int asym_prefer_cpu; /* CPU of highest priority in group */ 1849 int flags; 1850 1851 /* 1852 * The CPUs this group covers. 1853 * 1854 * NOTE: this field is variable length. (Allocated dynamically 1855 * by attaching extra space to the end of the structure, 1856 * depending on how many CPUs the kernel has booted up with) 1857 */ 1858 unsigned long cpumask[]; 1859 }; 1860 1861 static inline struct cpumask *sched_group_span(struct sched_group *sg) 1862 { 1863 return to_cpumask(sg->cpumask); 1864 } 1865 1866 /* 1867 * See build_balance_mask(). 1868 */ 1869 static inline struct cpumask *group_balance_mask(struct sched_group *sg) 1870 { 1871 return to_cpumask(sg->sgc->cpumask); 1872 } 1873 1874 extern int group_balance_cpu(struct sched_group *sg); 1875 1876 #ifdef CONFIG_SCHED_DEBUG 1877 void update_sched_domain_debugfs(void); 1878 void dirty_sched_domain_sysctl(int cpu); 1879 #else 1880 static inline void update_sched_domain_debugfs(void) 1881 { 1882 } 1883 static inline void dirty_sched_domain_sysctl(int cpu) 1884 { 1885 } 1886 #endif 1887 1888 extern int sched_update_scaling(void); 1889 1890 static inline const struct cpumask *task_user_cpus(struct task_struct *p) 1891 { 1892 if (!p->user_cpus_ptr) 1893 return cpu_possible_mask; /* &init_task.cpus_mask */ 1894 return p->user_cpus_ptr; 1895 } 1896 #endif /* CONFIG_SMP */ 1897 1898 #include "stats.h" 1899 1900 #if defined(CONFIG_SCHED_CORE) && defined(CONFIG_SCHEDSTATS) 1901 1902 extern void __sched_core_account_forceidle(struct rq *rq); 1903 1904 static inline void sched_core_account_forceidle(struct rq *rq) 1905 { 1906 if (schedstat_enabled()) 1907 __sched_core_account_forceidle(rq); 1908 } 1909 1910 extern void __sched_core_tick(struct rq *rq); 1911 1912 static inline void sched_core_tick(struct rq *rq) 1913 { 1914 if (sched_core_enabled(rq) && schedstat_enabled()) 1915 __sched_core_tick(rq); 1916 } 1917 1918 #else 1919 1920 static inline void sched_core_account_forceidle(struct rq *rq) {} 1921 1922 static inline void sched_core_tick(struct rq *rq) {} 1923 1924 #endif /* CONFIG_SCHED_CORE && CONFIG_SCHEDSTATS */ 1925 1926 #ifdef CONFIG_CGROUP_SCHED 1927 1928 /* 1929 * Return the group to which this tasks belongs. 1930 * 1931 * We cannot use task_css() and friends because the cgroup subsystem 1932 * changes that value before the cgroup_subsys::attach() method is called, 1933 * therefore we cannot pin it and might observe the wrong value. 1934 * 1935 * The same is true for autogroup's p->signal->autogroup->tg, the autogroup 1936 * core changes this before calling sched_move_task(). 1937 * 1938 * Instead we use a 'copy' which is updated from sched_move_task() while 1939 * holding both task_struct::pi_lock and rq::lock. 1940 */ 1941 static inline struct task_group *task_group(struct task_struct *p) 1942 { 1943 return p->sched_task_group; 1944 } 1945 1946 /* Change a task's cfs_rq and parent entity if it moves across CPUs/groups */ 1947 static inline void set_task_rq(struct task_struct *p, unsigned int cpu) 1948 { 1949 #if defined(CONFIG_FAIR_GROUP_SCHED) || defined(CONFIG_RT_GROUP_SCHED) 1950 struct task_group *tg = task_group(p); 1951 #endif 1952 1953 #ifdef CONFIG_FAIR_GROUP_SCHED 1954 set_task_rq_fair(&p->se, p->se.cfs_rq, tg->cfs_rq[cpu]); 1955 p->se.cfs_rq = tg->cfs_rq[cpu]; 1956 p->se.parent = tg->se[cpu]; 1957 p->se.depth = tg->se[cpu] ? tg->se[cpu]->depth + 1 : 0; 1958 #endif 1959 1960 #ifdef CONFIG_RT_GROUP_SCHED 1961 p->rt.rt_rq = tg->rt_rq[cpu]; 1962 p->rt.parent = tg->rt_se[cpu]; 1963 #endif 1964 } 1965 1966 #else /* CONFIG_CGROUP_SCHED */ 1967 1968 static inline void set_task_rq(struct task_struct *p, unsigned int cpu) { } 1969 static inline struct task_group *task_group(struct task_struct *p) 1970 { 1971 return NULL; 1972 } 1973 1974 #endif /* CONFIG_CGROUP_SCHED */ 1975 1976 static inline void __set_task_cpu(struct task_struct *p, unsigned int cpu) 1977 { 1978 set_task_rq(p, cpu); 1979 #ifdef CONFIG_SMP 1980 /* 1981 * After ->cpu is set up to a new value, task_rq_lock(p, ...) can be 1982 * successfully executed on another CPU. We must ensure that updates of 1983 * per-task data have been completed by this moment. 1984 */ 1985 smp_wmb(); 1986 WRITE_ONCE(task_thread_info(p)->cpu, cpu); 1987 p->wake_cpu = cpu; 1988 #endif 1989 } 1990 1991 /* 1992 * Tunables that become constants when CONFIG_SCHED_DEBUG is off: 1993 */ 1994 #ifdef CONFIG_SCHED_DEBUG 1995 # define const_debug __read_mostly 1996 #else 1997 # define const_debug const 1998 #endif 1999 2000 #define SCHED_FEAT(name, enabled) \ 2001 __SCHED_FEAT_##name , 2002 2003 enum { 2004 #include "features.h" 2005 __SCHED_FEAT_NR, 2006 }; 2007 2008 #undef SCHED_FEAT 2009 2010 #ifdef CONFIG_SCHED_DEBUG 2011 2012 /* 2013 * To support run-time toggling of sched features, all the translation units 2014 * (but core.c) reference the sysctl_sched_features defined in core.c. 2015 */ 2016 extern const_debug unsigned int sysctl_sched_features; 2017 2018 #ifdef CONFIG_JUMP_LABEL 2019 #define SCHED_FEAT(name, enabled) \ 2020 static __always_inline bool static_branch_##name(struct static_key *key) \ 2021 { \ 2022 return static_key_##enabled(key); \ 2023 } 2024 2025 #include "features.h" 2026 #undef SCHED_FEAT 2027 2028 extern struct static_key sched_feat_keys[__SCHED_FEAT_NR]; 2029 #define sched_feat(x) (static_branch_##x(&sched_feat_keys[__SCHED_FEAT_##x])) 2030 2031 #else /* !CONFIG_JUMP_LABEL */ 2032 2033 #define sched_feat(x) (sysctl_sched_features & (1UL << __SCHED_FEAT_##x)) 2034 2035 #endif /* CONFIG_JUMP_LABEL */ 2036 2037 #else /* !SCHED_DEBUG */ 2038 2039 /* 2040 * Each translation unit has its own copy of sysctl_sched_features to allow 2041 * constants propagation at compile time and compiler optimization based on 2042 * features default. 2043 */ 2044 #define SCHED_FEAT(name, enabled) \ 2045 (1UL << __SCHED_FEAT_##name) * enabled | 2046 static const_debug __maybe_unused unsigned int sysctl_sched_features = 2047 #include "features.h" 2048 0; 2049 #undef SCHED_FEAT 2050 2051 #define sched_feat(x) !!(sysctl_sched_features & (1UL << __SCHED_FEAT_##x)) 2052 2053 #endif /* SCHED_DEBUG */ 2054 2055 extern struct static_key_false sched_numa_balancing; 2056 extern struct static_key_false sched_schedstats; 2057 2058 static inline u64 global_rt_period(void) 2059 { 2060 return (u64)sysctl_sched_rt_period * NSEC_PER_USEC; 2061 } 2062 2063 static inline u64 global_rt_runtime(void) 2064 { 2065 if (sysctl_sched_rt_runtime < 0) 2066 return RUNTIME_INF; 2067 2068 return (u64)sysctl_sched_rt_runtime * NSEC_PER_USEC; 2069 } 2070 2071 static inline int task_current(struct rq *rq, struct task_struct *p) 2072 { 2073 return rq->curr == p; 2074 } 2075 2076 static inline int task_on_cpu(struct rq *rq, struct task_struct *p) 2077 { 2078 #ifdef CONFIG_SMP 2079 return p->on_cpu; 2080 #else 2081 return task_current(rq, p); 2082 #endif 2083 } 2084 2085 static inline int task_on_rq_queued(struct task_struct *p) 2086 { 2087 return p->on_rq == TASK_ON_RQ_QUEUED; 2088 } 2089 2090 static inline int task_on_rq_migrating(struct task_struct *p) 2091 { 2092 return READ_ONCE(p->on_rq) == TASK_ON_RQ_MIGRATING; 2093 } 2094 2095 /* Wake flags. The first three directly map to some SD flag value */ 2096 #define WF_EXEC 0x02 /* Wakeup after exec; maps to SD_BALANCE_EXEC */ 2097 #define WF_FORK 0x04 /* Wakeup after fork; maps to SD_BALANCE_FORK */ 2098 #define WF_TTWU 0x08 /* Wakeup; maps to SD_BALANCE_WAKE */ 2099 2100 #define WF_SYNC 0x10 /* Waker goes to sleep after wakeup */ 2101 #define WF_MIGRATED 0x20 /* Internal use, task got migrated */ 2102 2103 #ifdef CONFIG_SMP 2104 static_assert(WF_EXEC == SD_BALANCE_EXEC); 2105 static_assert(WF_FORK == SD_BALANCE_FORK); 2106 static_assert(WF_TTWU == SD_BALANCE_WAKE); 2107 #endif 2108 2109 /* 2110 * To aid in avoiding the subversion of "niceness" due to uneven distribution 2111 * of tasks with abnormal "nice" values across CPUs the contribution that 2112 * each task makes to its run queue's load is weighted according to its 2113 * scheduling class and "nice" value. For SCHED_NORMAL tasks this is just a 2114 * scaled version of the new time slice allocation that they receive on time 2115 * slice expiry etc. 2116 */ 2117 2118 #define WEIGHT_IDLEPRIO 3 2119 #define WMULT_IDLEPRIO 1431655765 2120 2121 extern const int sched_prio_to_weight[40]; 2122 extern const u32 sched_prio_to_wmult[40]; 2123 2124 /* 2125 * {de,en}queue flags: 2126 * 2127 * DEQUEUE_SLEEP - task is no longer runnable 2128 * ENQUEUE_WAKEUP - task just became runnable 2129 * 2130 * SAVE/RESTORE - an otherwise spurious dequeue/enqueue, done to ensure tasks 2131 * are in a known state which allows modification. Such pairs 2132 * should preserve as much state as possible. 2133 * 2134 * MOVE - paired with SAVE/RESTORE, explicitly does not preserve the location 2135 * in the runqueue. 2136 * 2137 * ENQUEUE_HEAD - place at front of runqueue (tail if not specified) 2138 * ENQUEUE_REPLENISH - CBS (replenish runtime and postpone deadline) 2139 * ENQUEUE_MIGRATED - the task was migrated during wakeup 2140 * 2141 */ 2142 2143 #define DEQUEUE_SLEEP 0x01 2144 #define DEQUEUE_SAVE 0x02 /* Matches ENQUEUE_RESTORE */ 2145 #define DEQUEUE_MOVE 0x04 /* Matches ENQUEUE_MOVE */ 2146 #define DEQUEUE_NOCLOCK 0x08 /* Matches ENQUEUE_NOCLOCK */ 2147 2148 #define ENQUEUE_WAKEUP 0x01 2149 #define ENQUEUE_RESTORE 0x02 2150 #define ENQUEUE_MOVE 0x04 2151 #define ENQUEUE_NOCLOCK 0x08 2152 2153 #define ENQUEUE_HEAD 0x10 2154 #define ENQUEUE_REPLENISH 0x20 2155 #ifdef CONFIG_SMP 2156 #define ENQUEUE_MIGRATED 0x40 2157 #else 2158 #define ENQUEUE_MIGRATED 0x00 2159 #endif 2160 2161 #define RETRY_TASK ((void *)-1UL) 2162 2163 struct affinity_context { 2164 const struct cpumask *new_mask; 2165 struct cpumask *user_mask; 2166 unsigned int flags; 2167 }; 2168 2169 struct sched_class { 2170 2171 #ifdef CONFIG_UCLAMP_TASK 2172 int uclamp_enabled; 2173 #endif 2174 2175 void (*enqueue_task) (struct rq *rq, struct task_struct *p, int flags); 2176 void (*dequeue_task) (struct rq *rq, struct task_struct *p, int flags); 2177 void (*yield_task) (struct rq *rq); 2178 bool (*yield_to_task)(struct rq *rq, struct task_struct *p); 2179 2180 void (*check_preempt_curr)(struct rq *rq, struct task_struct *p, int flags); 2181 2182 struct task_struct *(*pick_next_task)(struct rq *rq); 2183 2184 void (*put_prev_task)(struct rq *rq, struct task_struct *p); 2185 void (*set_next_task)(struct rq *rq, struct task_struct *p, bool first); 2186 2187 #ifdef CONFIG_SMP 2188 int (*balance)(struct rq *rq, struct task_struct *prev, struct rq_flags *rf); 2189 int (*select_task_rq)(struct task_struct *p, int task_cpu, int flags); 2190 2191 struct task_struct * (*pick_task)(struct rq *rq); 2192 2193 void (*migrate_task_rq)(struct task_struct *p, int new_cpu); 2194 2195 void (*task_woken)(struct rq *this_rq, struct task_struct *task); 2196 2197 void (*set_cpus_allowed)(struct task_struct *p, struct affinity_context *ctx); 2198 2199 void (*rq_online)(struct rq *rq); 2200 void (*rq_offline)(struct rq *rq); 2201 2202 struct rq *(*find_lock_rq)(struct task_struct *p, struct rq *rq); 2203 #endif 2204 2205 void (*task_tick)(struct rq *rq, struct task_struct *p, int queued); 2206 void (*task_fork)(struct task_struct *p); 2207 void (*task_dead)(struct task_struct *p); 2208 2209 /* 2210 * The switched_from() call is allowed to drop rq->lock, therefore we 2211 * cannot assume the switched_from/switched_to pair is serialized by 2212 * rq->lock. They are however serialized by p->pi_lock. 2213 */ 2214 void (*switched_from)(struct rq *this_rq, struct task_struct *task); 2215 void (*switched_to) (struct rq *this_rq, struct task_struct *task); 2216 void (*prio_changed) (struct rq *this_rq, struct task_struct *task, 2217 int oldprio); 2218 2219 unsigned int (*get_rr_interval)(struct rq *rq, 2220 struct task_struct *task); 2221 2222 void (*update_curr)(struct rq *rq); 2223 2224 #ifdef CONFIG_FAIR_GROUP_SCHED 2225 void (*task_change_group)(struct task_struct *p); 2226 #endif 2227 2228 #ifdef CONFIG_SCHED_CORE 2229 int (*task_is_throttled)(struct task_struct *p, int cpu); 2230 #endif 2231 }; 2232 2233 static inline void put_prev_task(struct rq *rq, struct task_struct *prev) 2234 { 2235 WARN_ON_ONCE(rq->curr != prev); 2236 prev->sched_class->put_prev_task(rq, prev); 2237 } 2238 2239 static inline void set_next_task(struct rq *rq, struct task_struct *next) 2240 { 2241 next->sched_class->set_next_task(rq, next, false); 2242 } 2243 2244 2245 /* 2246 * Helper to define a sched_class instance; each one is placed in a separate 2247 * section which is ordered by the linker script: 2248 * 2249 * include/asm-generic/vmlinux.lds.h 2250 * 2251 * *CAREFUL* they are laid out in *REVERSE* order!!! 2252 * 2253 * Also enforce alignment on the instance, not the type, to guarantee layout. 2254 */ 2255 #define DEFINE_SCHED_CLASS(name) \ 2256 const struct sched_class name##_sched_class \ 2257 __aligned(__alignof__(struct sched_class)) \ 2258 __section("__" #name "_sched_class") 2259 2260 /* Defined in include/asm-generic/vmlinux.lds.h */ 2261 extern struct sched_class __sched_class_highest[]; 2262 extern struct sched_class __sched_class_lowest[]; 2263 2264 #define for_class_range(class, _from, _to) \ 2265 for (class = (_from); class < (_to); class++) 2266 2267 #define for_each_class(class) \ 2268 for_class_range(class, __sched_class_highest, __sched_class_lowest) 2269 2270 #define sched_class_above(_a, _b) ((_a) < (_b)) 2271 2272 extern const struct sched_class stop_sched_class; 2273 extern const struct sched_class dl_sched_class; 2274 extern const struct sched_class rt_sched_class; 2275 extern const struct sched_class fair_sched_class; 2276 extern const struct sched_class idle_sched_class; 2277 2278 static inline bool sched_stop_runnable(struct rq *rq) 2279 { 2280 return rq->stop && task_on_rq_queued(rq->stop); 2281 } 2282 2283 static inline bool sched_dl_runnable(struct rq *rq) 2284 { 2285 return rq->dl.dl_nr_running > 0; 2286 } 2287 2288 static inline bool sched_rt_runnable(struct rq *rq) 2289 { 2290 return rq->rt.rt_queued > 0; 2291 } 2292 2293 static inline bool sched_fair_runnable(struct rq *rq) 2294 { 2295 return rq->cfs.nr_running > 0; 2296 } 2297 2298 extern struct task_struct *pick_next_task_fair(struct rq *rq, struct task_struct *prev, struct rq_flags *rf); 2299 extern struct task_struct *pick_next_task_idle(struct rq *rq); 2300 2301 #define SCA_CHECK 0x01 2302 #define SCA_MIGRATE_DISABLE 0x02 2303 #define SCA_MIGRATE_ENABLE 0x04 2304 #define SCA_USER 0x08 2305 2306 #ifdef CONFIG_SMP 2307 2308 extern void update_group_capacity(struct sched_domain *sd, int cpu); 2309 2310 extern void trigger_load_balance(struct rq *rq); 2311 2312 extern void set_cpus_allowed_common(struct task_struct *p, struct affinity_context *ctx); 2313 2314 static inline struct task_struct *get_push_task(struct rq *rq) 2315 { 2316 struct task_struct *p = rq->curr; 2317 2318 lockdep_assert_rq_held(rq); 2319 2320 if (rq->push_busy) 2321 return NULL; 2322 2323 if (p->nr_cpus_allowed == 1) 2324 return NULL; 2325 2326 if (p->migration_disabled) 2327 return NULL; 2328 2329 rq->push_busy = true; 2330 return get_task_struct(p); 2331 } 2332 2333 extern int push_cpu_stop(void *arg); 2334 2335 #endif 2336 2337 #ifdef CONFIG_CPU_IDLE 2338 static inline void idle_set_state(struct rq *rq, 2339 struct cpuidle_state *idle_state) 2340 { 2341 rq->idle_state = idle_state; 2342 } 2343 2344 static inline struct cpuidle_state *idle_get_state(struct rq *rq) 2345 { 2346 SCHED_WARN_ON(!rcu_read_lock_held()); 2347 2348 return rq->idle_state; 2349 } 2350 #else 2351 static inline void idle_set_state(struct rq *rq, 2352 struct cpuidle_state *idle_state) 2353 { 2354 } 2355 2356 static inline struct cpuidle_state *idle_get_state(struct rq *rq) 2357 { 2358 return NULL; 2359 } 2360 #endif 2361 2362 extern void schedule_idle(void); 2363 2364 extern void sysrq_sched_debug_show(void); 2365 extern void sched_init_granularity(void); 2366 extern void update_max_interval(void); 2367 2368 extern void init_sched_dl_class(void); 2369 extern void init_sched_rt_class(void); 2370 extern void init_sched_fair_class(void); 2371 2372 extern void reweight_task(struct task_struct *p, int prio); 2373 2374 extern void resched_curr(struct rq *rq); 2375 extern void resched_cpu(int cpu); 2376 2377 extern struct rt_bandwidth def_rt_bandwidth; 2378 extern void init_rt_bandwidth(struct rt_bandwidth *rt_b, u64 period, u64 runtime); 2379 extern bool sched_rt_bandwidth_account(struct rt_rq *rt_rq); 2380 2381 extern void init_dl_bandwidth(struct dl_bandwidth *dl_b, u64 period, u64 runtime); 2382 extern void init_dl_task_timer(struct sched_dl_entity *dl_se); 2383 extern void init_dl_inactive_task_timer(struct sched_dl_entity *dl_se); 2384 2385 #define BW_SHIFT 20 2386 #define BW_UNIT (1 << BW_SHIFT) 2387 #define RATIO_SHIFT 8 2388 #define MAX_BW_BITS (64 - BW_SHIFT) 2389 #define MAX_BW ((1ULL << MAX_BW_BITS) - 1) 2390 unsigned long to_ratio(u64 period, u64 runtime); 2391 2392 extern void init_entity_runnable_average(struct sched_entity *se); 2393 extern void post_init_entity_util_avg(struct task_struct *p); 2394 2395 #ifdef CONFIG_NO_HZ_FULL 2396 extern bool sched_can_stop_tick(struct rq *rq); 2397 extern int __init sched_tick_offload_init(void); 2398 2399 /* 2400 * Tick may be needed by tasks in the runqueue depending on their policy and 2401 * requirements. If tick is needed, lets send the target an IPI to kick it out of 2402 * nohz mode if necessary. 2403 */ 2404 static inline void sched_update_tick_dependency(struct rq *rq) 2405 { 2406 int cpu = cpu_of(rq); 2407 2408 if (!tick_nohz_full_cpu(cpu)) 2409 return; 2410 2411 if (sched_can_stop_tick(rq)) 2412 tick_nohz_dep_clear_cpu(cpu, TICK_DEP_BIT_SCHED); 2413 else 2414 tick_nohz_dep_set_cpu(cpu, TICK_DEP_BIT_SCHED); 2415 } 2416 #else 2417 static inline int sched_tick_offload_init(void) { return 0; } 2418 static inline void sched_update_tick_dependency(struct rq *rq) { } 2419 #endif 2420 2421 static inline void add_nr_running(struct rq *rq, unsigned count) 2422 { 2423 unsigned prev_nr = rq->nr_running; 2424 2425 rq->nr_running = prev_nr + count; 2426 if (trace_sched_update_nr_running_tp_enabled()) { 2427 call_trace_sched_update_nr_running(rq, count); 2428 } 2429 2430 #ifdef CONFIG_SMP 2431 if (prev_nr < 2 && rq->nr_running >= 2) { 2432 if (!READ_ONCE(rq->rd->overload)) 2433 WRITE_ONCE(rq->rd->overload, 1); 2434 } 2435 #endif 2436 2437 sched_update_tick_dependency(rq); 2438 } 2439 2440 static inline void sub_nr_running(struct rq *rq, unsigned count) 2441 { 2442 rq->nr_running -= count; 2443 if (trace_sched_update_nr_running_tp_enabled()) { 2444 call_trace_sched_update_nr_running(rq, -count); 2445 } 2446 2447 /* Check if we still need preemption */ 2448 sched_update_tick_dependency(rq); 2449 } 2450 2451 extern void activate_task(struct rq *rq, struct task_struct *p, int flags); 2452 extern void deactivate_task(struct rq *rq, struct task_struct *p, int flags); 2453 2454 extern void check_preempt_curr(struct rq *rq, struct task_struct *p, int flags); 2455 2456 #ifdef CONFIG_PREEMPT_RT 2457 #define SCHED_NR_MIGRATE_BREAK 8 2458 #else 2459 #define SCHED_NR_MIGRATE_BREAK 32 2460 #endif 2461 2462 extern const_debug unsigned int sysctl_sched_nr_migrate; 2463 extern const_debug unsigned int sysctl_sched_migration_cost; 2464 2465 #ifdef CONFIG_SCHED_DEBUG 2466 extern unsigned int sysctl_sched_latency; 2467 extern unsigned int sysctl_sched_min_granularity; 2468 extern unsigned int sysctl_sched_idle_min_granularity; 2469 extern unsigned int sysctl_sched_wakeup_granularity; 2470 extern int sysctl_resched_latency_warn_ms; 2471 extern int sysctl_resched_latency_warn_once; 2472 2473 extern unsigned int sysctl_sched_tunable_scaling; 2474 2475 extern unsigned int sysctl_numa_balancing_scan_delay; 2476 extern unsigned int sysctl_numa_balancing_scan_period_min; 2477 extern unsigned int sysctl_numa_balancing_scan_period_max; 2478 extern unsigned int sysctl_numa_balancing_scan_size; 2479 extern unsigned int sysctl_numa_balancing_hot_threshold; 2480 #endif 2481 2482 #ifdef CONFIG_SCHED_HRTICK 2483 2484 /* 2485 * Use hrtick when: 2486 * - enabled by features 2487 * - hrtimer is actually high res 2488 */ 2489 static inline int hrtick_enabled(struct rq *rq) 2490 { 2491 if (!cpu_active(cpu_of(rq))) 2492 return 0; 2493 return hrtimer_is_hres_active(&rq->hrtick_timer); 2494 } 2495 2496 static inline int hrtick_enabled_fair(struct rq *rq) 2497 { 2498 if (!sched_feat(HRTICK)) 2499 return 0; 2500 return hrtick_enabled(rq); 2501 } 2502 2503 static inline int hrtick_enabled_dl(struct rq *rq) 2504 { 2505 if (!sched_feat(HRTICK_DL)) 2506 return 0; 2507 return hrtick_enabled(rq); 2508 } 2509 2510 void hrtick_start(struct rq *rq, u64 delay); 2511 2512 #else 2513 2514 static inline int hrtick_enabled_fair(struct rq *rq) 2515 { 2516 return 0; 2517 } 2518 2519 static inline int hrtick_enabled_dl(struct rq *rq) 2520 { 2521 return 0; 2522 } 2523 2524 static inline int hrtick_enabled(struct rq *rq) 2525 { 2526 return 0; 2527 } 2528 2529 #endif /* CONFIG_SCHED_HRTICK */ 2530 2531 #ifndef arch_scale_freq_tick 2532 static __always_inline 2533 void arch_scale_freq_tick(void) 2534 { 2535 } 2536 #endif 2537 2538 #ifndef arch_scale_freq_capacity 2539 /** 2540 * arch_scale_freq_capacity - get the frequency scale factor of a given CPU. 2541 * @cpu: the CPU in question. 2542 * 2543 * Return: the frequency scale factor normalized against SCHED_CAPACITY_SCALE, i.e. 2544 * 2545 * f_curr 2546 * ------ * SCHED_CAPACITY_SCALE 2547 * f_max 2548 */ 2549 static __always_inline 2550 unsigned long arch_scale_freq_capacity(int cpu) 2551 { 2552 return SCHED_CAPACITY_SCALE; 2553 } 2554 #endif 2555 2556 #ifdef CONFIG_SCHED_DEBUG 2557 /* 2558 * In double_lock_balance()/double_rq_lock(), we use raw_spin_rq_lock() to 2559 * acquire rq lock instead of rq_lock(). So at the end of these two functions 2560 * we need to call double_rq_clock_clear_update() to clear RQCF_UPDATED of 2561 * rq->clock_update_flags to avoid the WARN_DOUBLE_CLOCK warning. 2562 */ 2563 static inline void double_rq_clock_clear_update(struct rq *rq1, struct rq *rq2) 2564 { 2565 rq1->clock_update_flags &= (RQCF_REQ_SKIP|RQCF_ACT_SKIP); 2566 /* rq1 == rq2 for !CONFIG_SMP, so just clear RQCF_UPDATED once. */ 2567 #ifdef CONFIG_SMP 2568 rq2->clock_update_flags &= (RQCF_REQ_SKIP|RQCF_ACT_SKIP); 2569 #endif 2570 } 2571 #else 2572 static inline void double_rq_clock_clear_update(struct rq *rq1, struct rq *rq2) {} 2573 #endif 2574 2575 #ifdef CONFIG_SMP 2576 2577 static inline bool rq_order_less(struct rq *rq1, struct rq *rq2) 2578 { 2579 #ifdef CONFIG_SCHED_CORE 2580 /* 2581 * In order to not have {0,2},{1,3} turn into into an AB-BA, 2582 * order by core-id first and cpu-id second. 2583 * 2584 * Notably: 2585 * 2586 * double_rq_lock(0,3); will take core-0, core-1 lock 2587 * double_rq_lock(1,2); will take core-1, core-0 lock 2588 * 2589 * when only cpu-id is considered. 2590 */ 2591 if (rq1->core->cpu < rq2->core->cpu) 2592 return true; 2593 if (rq1->core->cpu > rq2->core->cpu) 2594 return false; 2595 2596 /* 2597 * __sched_core_flip() relies on SMT having cpu-id lock order. 2598 */ 2599 #endif 2600 return rq1->cpu < rq2->cpu; 2601 } 2602 2603 extern void double_rq_lock(struct rq *rq1, struct rq *rq2); 2604 2605 #ifdef CONFIG_PREEMPTION 2606 2607 /* 2608 * fair double_lock_balance: Safely acquires both rq->locks in a fair 2609 * way at the expense of forcing extra atomic operations in all 2610 * invocations. This assures that the double_lock is acquired using the 2611 * same underlying policy as the spinlock_t on this architecture, which 2612 * reduces latency compared to the unfair variant below. However, it 2613 * also adds more overhead and therefore may reduce throughput. 2614 */ 2615 static inline int _double_lock_balance(struct rq *this_rq, struct rq *busiest) 2616 __releases(this_rq->lock) 2617 __acquires(busiest->lock) 2618 __acquires(this_rq->lock) 2619 { 2620 raw_spin_rq_unlock(this_rq); 2621 double_rq_lock(this_rq, busiest); 2622 2623 return 1; 2624 } 2625 2626 #else 2627 /* 2628 * Unfair double_lock_balance: Optimizes throughput at the expense of 2629 * latency by eliminating extra atomic operations when the locks are 2630 * already in proper order on entry. This favors lower CPU-ids and will 2631 * grant the double lock to lower CPUs over higher ids under contention, 2632 * regardless of entry order into the function. 2633 */ 2634 static inline int _double_lock_balance(struct rq *this_rq, struct rq *busiest) 2635 __releases(this_rq->lock) 2636 __acquires(busiest->lock) 2637 __acquires(this_rq->lock) 2638 { 2639 if (__rq_lockp(this_rq) == __rq_lockp(busiest) || 2640 likely(raw_spin_rq_trylock(busiest))) { 2641 double_rq_clock_clear_update(this_rq, busiest); 2642 return 0; 2643 } 2644 2645 if (rq_order_less(this_rq, busiest)) { 2646 raw_spin_rq_lock_nested(busiest, SINGLE_DEPTH_NESTING); 2647 double_rq_clock_clear_update(this_rq, busiest); 2648 return 0; 2649 } 2650 2651 raw_spin_rq_unlock(this_rq); 2652 double_rq_lock(this_rq, busiest); 2653 2654 return 1; 2655 } 2656 2657 #endif /* CONFIG_PREEMPTION */ 2658 2659 /* 2660 * double_lock_balance - lock the busiest runqueue, this_rq is locked already. 2661 */ 2662 static inline int double_lock_balance(struct rq *this_rq, struct rq *busiest) 2663 { 2664 lockdep_assert_irqs_disabled(); 2665 2666 return _double_lock_balance(this_rq, busiest); 2667 } 2668 2669 static inline void double_unlock_balance(struct rq *this_rq, struct rq *busiest) 2670 __releases(busiest->lock) 2671 { 2672 if (__rq_lockp(this_rq) != __rq_lockp(busiest)) 2673 raw_spin_rq_unlock(busiest); 2674 lock_set_subclass(&__rq_lockp(this_rq)->dep_map, 0, _RET_IP_); 2675 } 2676 2677 static inline void double_lock(spinlock_t *l1, spinlock_t *l2) 2678 { 2679 if (l1 > l2) 2680 swap(l1, l2); 2681 2682 spin_lock(l1); 2683 spin_lock_nested(l2, SINGLE_DEPTH_NESTING); 2684 } 2685 2686 static inline void double_lock_irq(spinlock_t *l1, spinlock_t *l2) 2687 { 2688 if (l1 > l2) 2689 swap(l1, l2); 2690 2691 spin_lock_irq(l1); 2692 spin_lock_nested(l2, SINGLE_DEPTH_NESTING); 2693 } 2694 2695 static inline void double_raw_lock(raw_spinlock_t *l1, raw_spinlock_t *l2) 2696 { 2697 if (l1 > l2) 2698 swap(l1, l2); 2699 2700 raw_spin_lock(l1); 2701 raw_spin_lock_nested(l2, SINGLE_DEPTH_NESTING); 2702 } 2703 2704 /* 2705 * double_rq_unlock - safely unlock two runqueues 2706 * 2707 * Note this does not restore interrupts like task_rq_unlock, 2708 * you need to do so manually after calling. 2709 */ 2710 static inline void double_rq_unlock(struct rq *rq1, struct rq *rq2) 2711 __releases(rq1->lock) 2712 __releases(rq2->lock) 2713 { 2714 if (__rq_lockp(rq1) != __rq_lockp(rq2)) 2715 raw_spin_rq_unlock(rq2); 2716 else 2717 __release(rq2->lock); 2718 raw_spin_rq_unlock(rq1); 2719 } 2720 2721 extern void set_rq_online (struct rq *rq); 2722 extern void set_rq_offline(struct rq *rq); 2723 extern bool sched_smp_initialized; 2724 2725 #else /* CONFIG_SMP */ 2726 2727 /* 2728 * double_rq_lock - safely lock two runqueues 2729 * 2730 * Note this does not disable interrupts like task_rq_lock, 2731 * you need to do so manually before calling. 2732 */ 2733 static inline void double_rq_lock(struct rq *rq1, struct rq *rq2) 2734 __acquires(rq1->lock) 2735 __acquires(rq2->lock) 2736 { 2737 WARN_ON_ONCE(!irqs_disabled()); 2738 WARN_ON_ONCE(rq1 != rq2); 2739 raw_spin_rq_lock(rq1); 2740 __acquire(rq2->lock); /* Fake it out ;) */ 2741 double_rq_clock_clear_update(rq1, rq2); 2742 } 2743 2744 /* 2745 * double_rq_unlock - safely unlock two runqueues 2746 * 2747 * Note this does not restore interrupts like task_rq_unlock, 2748 * you need to do so manually after calling. 2749 */ 2750 static inline void double_rq_unlock(struct rq *rq1, struct rq *rq2) 2751 __releases(rq1->lock) 2752 __releases(rq2->lock) 2753 { 2754 WARN_ON_ONCE(rq1 != rq2); 2755 raw_spin_rq_unlock(rq1); 2756 __release(rq2->lock); 2757 } 2758 2759 #endif 2760 2761 extern struct sched_entity *__pick_first_entity(struct cfs_rq *cfs_rq); 2762 extern struct sched_entity *__pick_last_entity(struct cfs_rq *cfs_rq); 2763 2764 #ifdef CONFIG_SCHED_DEBUG 2765 extern bool sched_debug_verbose; 2766 2767 extern void print_cfs_stats(struct seq_file *m, int cpu); 2768 extern void print_rt_stats(struct seq_file *m, int cpu); 2769 extern void print_dl_stats(struct seq_file *m, int cpu); 2770 extern void print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq); 2771 extern void print_rt_rq(struct seq_file *m, int cpu, struct rt_rq *rt_rq); 2772 extern void print_dl_rq(struct seq_file *m, int cpu, struct dl_rq *dl_rq); 2773 2774 extern void resched_latency_warn(int cpu, u64 latency); 2775 #ifdef CONFIG_NUMA_BALANCING 2776 extern void 2777 show_numa_stats(struct task_struct *p, struct seq_file *m); 2778 extern void 2779 print_numa_stats(struct seq_file *m, int node, unsigned long tsf, 2780 unsigned long tpf, unsigned long gsf, unsigned long gpf); 2781 #endif /* CONFIG_NUMA_BALANCING */ 2782 #else 2783 static inline void resched_latency_warn(int cpu, u64 latency) {} 2784 #endif /* CONFIG_SCHED_DEBUG */ 2785 2786 extern void init_cfs_rq(struct cfs_rq *cfs_rq); 2787 extern void init_rt_rq(struct rt_rq *rt_rq); 2788 extern void init_dl_rq(struct dl_rq *dl_rq); 2789 2790 extern void cfs_bandwidth_usage_inc(void); 2791 extern void cfs_bandwidth_usage_dec(void); 2792 2793 #ifdef CONFIG_NO_HZ_COMMON 2794 #define NOHZ_BALANCE_KICK_BIT 0 2795 #define NOHZ_STATS_KICK_BIT 1 2796 #define NOHZ_NEWILB_KICK_BIT 2 2797 #define NOHZ_NEXT_KICK_BIT 3 2798 2799 /* Run rebalance_domains() */ 2800 #define NOHZ_BALANCE_KICK BIT(NOHZ_BALANCE_KICK_BIT) 2801 /* Update blocked load */ 2802 #define NOHZ_STATS_KICK BIT(NOHZ_STATS_KICK_BIT) 2803 /* Update blocked load when entering idle */ 2804 #define NOHZ_NEWILB_KICK BIT(NOHZ_NEWILB_KICK_BIT) 2805 /* Update nohz.next_balance */ 2806 #define NOHZ_NEXT_KICK BIT(NOHZ_NEXT_KICK_BIT) 2807 2808 #define NOHZ_KICK_MASK (NOHZ_BALANCE_KICK | NOHZ_STATS_KICK | NOHZ_NEXT_KICK) 2809 2810 #define nohz_flags(cpu) (&cpu_rq(cpu)->nohz_flags) 2811 2812 extern void nohz_balance_exit_idle(struct rq *rq); 2813 #else 2814 static inline void nohz_balance_exit_idle(struct rq *rq) { } 2815 #endif 2816 2817 #if defined(CONFIG_SMP) && defined(CONFIG_NO_HZ_COMMON) 2818 extern void nohz_run_idle_balance(int cpu); 2819 #else 2820 static inline void nohz_run_idle_balance(int cpu) { } 2821 #endif 2822 2823 #ifdef CONFIG_IRQ_TIME_ACCOUNTING 2824 struct irqtime { 2825 u64 total; 2826 u64 tick_delta; 2827 u64 irq_start_time; 2828 struct u64_stats_sync sync; 2829 }; 2830 2831 DECLARE_PER_CPU(struct irqtime, cpu_irqtime); 2832 2833 /* 2834 * Returns the irqtime minus the softirq time computed by ksoftirqd. 2835 * Otherwise ksoftirqd's sum_exec_runtime is subtracted its own runtime 2836 * and never move forward. 2837 */ 2838 static inline u64 irq_time_read(int cpu) 2839 { 2840 struct irqtime *irqtime = &per_cpu(cpu_irqtime, cpu); 2841 unsigned int seq; 2842 u64 total; 2843 2844 do { 2845 seq = __u64_stats_fetch_begin(&irqtime->sync); 2846 total = irqtime->total; 2847 } while (__u64_stats_fetch_retry(&irqtime->sync, seq)); 2848 2849 return total; 2850 } 2851 #endif /* CONFIG_IRQ_TIME_ACCOUNTING */ 2852 2853 #ifdef CONFIG_CPU_FREQ 2854 DECLARE_PER_CPU(struct update_util_data __rcu *, cpufreq_update_util_data); 2855 2856 /** 2857 * cpufreq_update_util - Take a note about CPU utilization changes. 2858 * @rq: Runqueue to carry out the update for. 2859 * @flags: Update reason flags. 2860 * 2861 * This function is called by the scheduler on the CPU whose utilization is 2862 * being updated. 2863 * 2864 * It can only be called from RCU-sched read-side critical sections. 2865 * 2866 * The way cpufreq is currently arranged requires it to evaluate the CPU 2867 * performance state (frequency/voltage) on a regular basis to prevent it from 2868 * being stuck in a completely inadequate performance level for too long. 2869 * That is not guaranteed to happen if the updates are only triggered from CFS 2870 * and DL, though, because they may not be coming in if only RT tasks are 2871 * active all the time (or there are RT tasks only). 2872 * 2873 * As a workaround for that issue, this function is called periodically by the 2874 * RT sched class to trigger extra cpufreq updates to prevent it from stalling, 2875 * but that really is a band-aid. Going forward it should be replaced with 2876 * solutions targeted more specifically at RT tasks. 2877 */ 2878 static inline void cpufreq_update_util(struct rq *rq, unsigned int flags) 2879 { 2880 struct update_util_data *data; 2881 2882 data = rcu_dereference_sched(*per_cpu_ptr(&cpufreq_update_util_data, 2883 cpu_of(rq))); 2884 if (data) 2885 data->func(data, rq_clock(rq), flags); 2886 } 2887 #else 2888 static inline void cpufreq_update_util(struct rq *rq, unsigned int flags) {} 2889 #endif /* CONFIG_CPU_FREQ */ 2890 2891 #ifdef arch_scale_freq_capacity 2892 # ifndef arch_scale_freq_invariant 2893 # define arch_scale_freq_invariant() true 2894 # endif 2895 #else 2896 # define arch_scale_freq_invariant() false 2897 #endif 2898 2899 #ifdef CONFIG_SMP 2900 static inline unsigned long capacity_orig_of(int cpu) 2901 { 2902 return cpu_rq(cpu)->cpu_capacity_orig; 2903 } 2904 2905 /** 2906 * enum cpu_util_type - CPU utilization type 2907 * @FREQUENCY_UTIL: Utilization used to select frequency 2908 * @ENERGY_UTIL: Utilization used during energy calculation 2909 * 2910 * The utilization signals of all scheduling classes (CFS/RT/DL) and IRQ time 2911 * need to be aggregated differently depending on the usage made of them. This 2912 * enum is used within effective_cpu_util() to differentiate the types of 2913 * utilization expected by the callers, and adjust the aggregation accordingly. 2914 */ 2915 enum cpu_util_type { 2916 FREQUENCY_UTIL, 2917 ENERGY_UTIL, 2918 }; 2919 2920 unsigned long effective_cpu_util(int cpu, unsigned long util_cfs, 2921 enum cpu_util_type type, 2922 struct task_struct *p); 2923 2924 /* 2925 * Verify the fitness of task @p to run on @cpu taking into account the 2926 * CPU original capacity and the runtime/deadline ratio of the task. 2927 * 2928 * The function will return true if the original capacity of @cpu is 2929 * greater than or equal to task's deadline density right shifted by 2930 * (BW_SHIFT - SCHED_CAPACITY_SHIFT) and false otherwise. 2931 */ 2932 static inline bool dl_task_fits_capacity(struct task_struct *p, int cpu) 2933 { 2934 unsigned long cap = arch_scale_cpu_capacity(cpu); 2935 2936 return cap >= p->dl.dl_density >> (BW_SHIFT - SCHED_CAPACITY_SHIFT); 2937 } 2938 2939 static inline unsigned long cpu_bw_dl(struct rq *rq) 2940 { 2941 return (rq->dl.running_bw * SCHED_CAPACITY_SCALE) >> BW_SHIFT; 2942 } 2943 2944 static inline unsigned long cpu_util_dl(struct rq *rq) 2945 { 2946 return READ_ONCE(rq->avg_dl.util_avg); 2947 } 2948 2949 /** 2950 * cpu_util_cfs() - Estimates the amount of CPU capacity used by CFS tasks. 2951 * @cpu: the CPU to get the utilization for. 2952 * 2953 * The unit of the return value must be the same as the one of CPU capacity 2954 * so that CPU utilization can be compared with CPU capacity. 2955 * 2956 * CPU utilization is the sum of running time of runnable tasks plus the 2957 * recent utilization of currently non-runnable tasks on that CPU. 2958 * It represents the amount of CPU capacity currently used by CFS tasks in 2959 * the range [0..max CPU capacity] with max CPU capacity being the CPU 2960 * capacity at f_max. 2961 * 2962 * The estimated CPU utilization is defined as the maximum between CPU 2963 * utilization and sum of the estimated utilization of the currently 2964 * runnable tasks on that CPU. It preserves a utilization "snapshot" of 2965 * previously-executed tasks, which helps better deduce how busy a CPU will 2966 * be when a long-sleeping task wakes up. The contribution to CPU utilization 2967 * of such a task would be significantly decayed at this point of time. 2968 * 2969 * CPU utilization can be higher than the current CPU capacity 2970 * (f_curr/f_max * max CPU capacity) or even the max CPU capacity because 2971 * of rounding errors as well as task migrations or wakeups of new tasks. 2972 * CPU utilization has to be capped to fit into the [0..max CPU capacity] 2973 * range. Otherwise a group of CPUs (CPU0 util = 121% + CPU1 util = 80%) 2974 * could be seen as over-utilized even though CPU1 has 20% of spare CPU 2975 * capacity. CPU utilization is allowed to overshoot current CPU capacity 2976 * though since this is useful for predicting the CPU capacity required 2977 * after task migrations (scheduler-driven DVFS). 2978 * 2979 * Return: (Estimated) utilization for the specified CPU. 2980 */ 2981 static inline unsigned long cpu_util_cfs(int cpu) 2982 { 2983 struct cfs_rq *cfs_rq; 2984 unsigned long util; 2985 2986 cfs_rq = &cpu_rq(cpu)->cfs; 2987 util = READ_ONCE(cfs_rq->avg.util_avg); 2988 2989 if (sched_feat(UTIL_EST)) { 2990 util = max_t(unsigned long, util, 2991 READ_ONCE(cfs_rq->avg.util_est.enqueued)); 2992 } 2993 2994 return min(util, capacity_orig_of(cpu)); 2995 } 2996 2997 static inline unsigned long cpu_util_rt(struct rq *rq) 2998 { 2999 return READ_ONCE(rq->avg_rt.util_avg); 3000 } 3001 #endif 3002 3003 #ifdef CONFIG_UCLAMP_TASK 3004 unsigned long uclamp_eff_value(struct task_struct *p, enum uclamp_id clamp_id); 3005 3006 static inline unsigned long uclamp_rq_get(struct rq *rq, 3007 enum uclamp_id clamp_id) 3008 { 3009 return READ_ONCE(rq->uclamp[clamp_id].value); 3010 } 3011 3012 static inline void uclamp_rq_set(struct rq *rq, enum uclamp_id clamp_id, 3013 unsigned int value) 3014 { 3015 WRITE_ONCE(rq->uclamp[clamp_id].value, value); 3016 } 3017 3018 static inline bool uclamp_rq_is_idle(struct rq *rq) 3019 { 3020 return rq->uclamp_flags & UCLAMP_FLAG_IDLE; 3021 } 3022 3023 /** 3024 * uclamp_rq_util_with - clamp @util with @rq and @p effective uclamp values. 3025 * @rq: The rq to clamp against. Must not be NULL. 3026 * @util: The util value to clamp. 3027 * @p: The task to clamp against. Can be NULL if you want to clamp 3028 * against @rq only. 3029 * 3030 * Clamps the passed @util to the max(@rq, @p) effective uclamp values. 3031 * 3032 * If sched_uclamp_used static key is disabled, then just return the util 3033 * without any clamping since uclamp aggregation at the rq level in the fast 3034 * path is disabled, rendering this operation a NOP. 3035 * 3036 * Use uclamp_eff_value() if you don't care about uclamp values at rq level. It 3037 * will return the correct effective uclamp value of the task even if the 3038 * static key is disabled. 3039 */ 3040 static __always_inline 3041 unsigned long uclamp_rq_util_with(struct rq *rq, unsigned long util, 3042 struct task_struct *p) 3043 { 3044 unsigned long min_util = 0; 3045 unsigned long max_util = 0; 3046 3047 if (!static_branch_likely(&sched_uclamp_used)) 3048 return util; 3049 3050 if (p) { 3051 min_util = uclamp_eff_value(p, UCLAMP_MIN); 3052 max_util = uclamp_eff_value(p, UCLAMP_MAX); 3053 3054 /* 3055 * Ignore last runnable task's max clamp, as this task will 3056 * reset it. Similarly, no need to read the rq's min clamp. 3057 */ 3058 if (uclamp_rq_is_idle(rq)) 3059 goto out; 3060 } 3061 3062 min_util = max_t(unsigned long, min_util, uclamp_rq_get(rq, UCLAMP_MIN)); 3063 max_util = max_t(unsigned long, max_util, uclamp_rq_get(rq, UCLAMP_MAX)); 3064 out: 3065 /* 3066 * Since CPU's {min,max}_util clamps are MAX aggregated considering 3067 * RUNNABLE tasks with _different_ clamps, we can end up with an 3068 * inversion. Fix it now when the clamps are applied. 3069 */ 3070 if (unlikely(min_util >= max_util)) 3071 return min_util; 3072 3073 return clamp(util, min_util, max_util); 3074 } 3075 3076 /* Is the rq being capped/throttled by uclamp_max? */ 3077 static inline bool uclamp_rq_is_capped(struct rq *rq) 3078 { 3079 unsigned long rq_util; 3080 unsigned long max_util; 3081 3082 if (!static_branch_likely(&sched_uclamp_used)) 3083 return false; 3084 3085 rq_util = cpu_util_cfs(cpu_of(rq)) + cpu_util_rt(rq); 3086 max_util = READ_ONCE(rq->uclamp[UCLAMP_MAX].value); 3087 3088 return max_util != SCHED_CAPACITY_SCALE && rq_util >= max_util; 3089 } 3090 3091 /* 3092 * When uclamp is compiled in, the aggregation at rq level is 'turned off' 3093 * by default in the fast path and only gets turned on once userspace performs 3094 * an operation that requires it. 3095 * 3096 * Returns true if userspace opted-in to use uclamp and aggregation at rq level 3097 * hence is active. 3098 */ 3099 static inline bool uclamp_is_used(void) 3100 { 3101 return static_branch_likely(&sched_uclamp_used); 3102 } 3103 #else /* CONFIG_UCLAMP_TASK */ 3104 static inline unsigned long uclamp_eff_value(struct task_struct *p, 3105 enum uclamp_id clamp_id) 3106 { 3107 if (clamp_id == UCLAMP_MIN) 3108 return 0; 3109 3110 return SCHED_CAPACITY_SCALE; 3111 } 3112 3113 static inline 3114 unsigned long uclamp_rq_util_with(struct rq *rq, unsigned long util, 3115 struct task_struct *p) 3116 { 3117 return util; 3118 } 3119 3120 static inline bool uclamp_rq_is_capped(struct rq *rq) { return false; } 3121 3122 static inline bool uclamp_is_used(void) 3123 { 3124 return false; 3125 } 3126 3127 static inline unsigned long uclamp_rq_get(struct rq *rq, 3128 enum uclamp_id clamp_id) 3129 { 3130 if (clamp_id == UCLAMP_MIN) 3131 return 0; 3132 3133 return SCHED_CAPACITY_SCALE; 3134 } 3135 3136 static inline void uclamp_rq_set(struct rq *rq, enum uclamp_id clamp_id, 3137 unsigned int value) 3138 { 3139 } 3140 3141 static inline bool uclamp_rq_is_idle(struct rq *rq) 3142 { 3143 return false; 3144 } 3145 #endif /* CONFIG_UCLAMP_TASK */ 3146 3147 #ifdef CONFIG_HAVE_SCHED_AVG_IRQ 3148 static inline unsigned long cpu_util_irq(struct rq *rq) 3149 { 3150 return rq->avg_irq.util_avg; 3151 } 3152 3153 static inline 3154 unsigned long scale_irq_capacity(unsigned long util, unsigned long irq, unsigned long max) 3155 { 3156 util *= (max - irq); 3157 util /= max; 3158 3159 return util; 3160 3161 } 3162 #else 3163 static inline unsigned long cpu_util_irq(struct rq *rq) 3164 { 3165 return 0; 3166 } 3167 3168 static inline 3169 unsigned long scale_irq_capacity(unsigned long util, unsigned long irq, unsigned long max) 3170 { 3171 return util; 3172 } 3173 #endif 3174 3175 #if defined(CONFIG_ENERGY_MODEL) && defined(CONFIG_CPU_FREQ_GOV_SCHEDUTIL) 3176 3177 #define perf_domain_span(pd) (to_cpumask(((pd)->em_pd->cpus))) 3178 3179 DECLARE_STATIC_KEY_FALSE(sched_energy_present); 3180 3181 static inline bool sched_energy_enabled(void) 3182 { 3183 return static_branch_unlikely(&sched_energy_present); 3184 } 3185 3186 #else /* ! (CONFIG_ENERGY_MODEL && CONFIG_CPU_FREQ_GOV_SCHEDUTIL) */ 3187 3188 #define perf_domain_span(pd) NULL 3189 static inline bool sched_energy_enabled(void) { return false; } 3190 3191 #endif /* CONFIG_ENERGY_MODEL && CONFIG_CPU_FREQ_GOV_SCHEDUTIL */ 3192 3193 #ifdef CONFIG_MEMBARRIER 3194 /* 3195 * The scheduler provides memory barriers required by membarrier between: 3196 * - prior user-space memory accesses and store to rq->membarrier_state, 3197 * - store to rq->membarrier_state and following user-space memory accesses. 3198 * In the same way it provides those guarantees around store to rq->curr. 3199 */ 3200 static inline void membarrier_switch_mm(struct rq *rq, 3201 struct mm_struct *prev_mm, 3202 struct mm_struct *next_mm) 3203 { 3204 int membarrier_state; 3205 3206 if (prev_mm == next_mm) 3207 return; 3208 3209 membarrier_state = atomic_read(&next_mm->membarrier_state); 3210 if (READ_ONCE(rq->membarrier_state) == membarrier_state) 3211 return; 3212 3213 WRITE_ONCE(rq->membarrier_state, membarrier_state); 3214 } 3215 #else 3216 static inline void membarrier_switch_mm(struct rq *rq, 3217 struct mm_struct *prev_mm, 3218 struct mm_struct *next_mm) 3219 { 3220 } 3221 #endif 3222 3223 #ifdef CONFIG_SMP 3224 static inline bool is_per_cpu_kthread(struct task_struct *p) 3225 { 3226 if (!(p->flags & PF_KTHREAD)) 3227 return false; 3228 3229 if (p->nr_cpus_allowed != 1) 3230 return false; 3231 3232 return true; 3233 } 3234 #endif 3235 3236 extern void swake_up_all_locked(struct swait_queue_head *q); 3237 extern void __prepare_to_swait(struct swait_queue_head *q, struct swait_queue *wait); 3238 3239 #ifdef CONFIG_PREEMPT_DYNAMIC 3240 extern int preempt_dynamic_mode; 3241 extern int sched_dynamic_mode(const char *str); 3242 extern void sched_dynamic_update(int mode); 3243 #endif 3244 3245 static inline void update_current_exec_runtime(struct task_struct *curr, 3246 u64 now, u64 delta_exec) 3247 { 3248 curr->se.sum_exec_runtime += delta_exec; 3249 account_group_exec_runtime(curr, delta_exec); 3250 3251 curr->se.exec_start = now; 3252 cgroup_account_cputime(curr, delta_exec); 3253 } 3254 3255 #ifdef CONFIG_SCHED_MM_CID 3256 3257 #define SCHED_MM_CID_PERIOD_NS (100ULL * 1000000) /* 100ms */ 3258 #define MM_CID_SCAN_DELAY 100 /* 100ms */ 3259 3260 extern raw_spinlock_t cid_lock; 3261 extern int use_cid_lock; 3262 3263 extern void sched_mm_cid_migrate_from(struct task_struct *t); 3264 extern void sched_mm_cid_migrate_to(struct rq *dst_rq, struct task_struct *t); 3265 extern void task_tick_mm_cid(struct rq *rq, struct task_struct *curr); 3266 extern void init_sched_mm_cid(struct task_struct *t); 3267 3268 static inline void __mm_cid_put(struct mm_struct *mm, int cid) 3269 { 3270 if (cid < 0) 3271 return; 3272 cpumask_clear_cpu(cid, mm_cidmask(mm)); 3273 } 3274 3275 /* 3276 * The per-mm/cpu cid can have the MM_CID_LAZY_PUT flag set or transition to 3277 * the MM_CID_UNSET state without holding the rq lock, but the rq lock needs to 3278 * be held to transition to other states. 3279 * 3280 * State transitions synchronized with cmpxchg or try_cmpxchg need to be 3281 * consistent across cpus, which prevents use of this_cpu_cmpxchg. 3282 */ 3283 static inline void mm_cid_put_lazy(struct task_struct *t) 3284 { 3285 struct mm_struct *mm = t->mm; 3286 struct mm_cid __percpu *pcpu_cid = mm->pcpu_cid; 3287 int cid; 3288 3289 lockdep_assert_irqs_disabled(); 3290 cid = __this_cpu_read(pcpu_cid->cid); 3291 if (!mm_cid_is_lazy_put(cid) || 3292 !try_cmpxchg(&this_cpu_ptr(pcpu_cid)->cid, &cid, MM_CID_UNSET)) 3293 return; 3294 __mm_cid_put(mm, mm_cid_clear_lazy_put(cid)); 3295 } 3296 3297 static inline int mm_cid_pcpu_unset(struct mm_struct *mm) 3298 { 3299 struct mm_cid __percpu *pcpu_cid = mm->pcpu_cid; 3300 int cid, res; 3301 3302 lockdep_assert_irqs_disabled(); 3303 cid = __this_cpu_read(pcpu_cid->cid); 3304 for (;;) { 3305 if (mm_cid_is_unset(cid)) 3306 return MM_CID_UNSET; 3307 /* 3308 * Attempt transition from valid or lazy-put to unset. 3309 */ 3310 res = cmpxchg(&this_cpu_ptr(pcpu_cid)->cid, cid, MM_CID_UNSET); 3311 if (res == cid) 3312 break; 3313 cid = res; 3314 } 3315 return cid; 3316 } 3317 3318 static inline void mm_cid_put(struct mm_struct *mm) 3319 { 3320 int cid; 3321 3322 lockdep_assert_irqs_disabled(); 3323 cid = mm_cid_pcpu_unset(mm); 3324 if (cid == MM_CID_UNSET) 3325 return; 3326 __mm_cid_put(mm, mm_cid_clear_lazy_put(cid)); 3327 } 3328 3329 static inline int __mm_cid_try_get(struct mm_struct *mm) 3330 { 3331 struct cpumask *cpumask; 3332 int cid; 3333 3334 cpumask = mm_cidmask(mm); 3335 /* 3336 * Retry finding first zero bit if the mask is temporarily 3337 * filled. This only happens during concurrent remote-clear 3338 * which owns a cid without holding a rq lock. 3339 */ 3340 for (;;) { 3341 cid = cpumask_first_zero(cpumask); 3342 if (cid < nr_cpu_ids) 3343 break; 3344 cpu_relax(); 3345 } 3346 if (cpumask_test_and_set_cpu(cid, cpumask)) 3347 return -1; 3348 return cid; 3349 } 3350 3351 /* 3352 * Save a snapshot of the current runqueue time of this cpu 3353 * with the per-cpu cid value, allowing to estimate how recently it was used. 3354 */ 3355 static inline void mm_cid_snapshot_time(struct rq *rq, struct mm_struct *mm) 3356 { 3357 struct mm_cid *pcpu_cid = per_cpu_ptr(mm->pcpu_cid, cpu_of(rq)); 3358 3359 lockdep_assert_rq_held(rq); 3360 WRITE_ONCE(pcpu_cid->time, rq->clock); 3361 } 3362 3363 static inline int __mm_cid_get(struct rq *rq, struct mm_struct *mm) 3364 { 3365 int cid; 3366 3367 /* 3368 * All allocations (even those using the cid_lock) are lock-free. If 3369 * use_cid_lock is set, hold the cid_lock to perform cid allocation to 3370 * guarantee forward progress. 3371 */ 3372 if (!READ_ONCE(use_cid_lock)) { 3373 cid = __mm_cid_try_get(mm); 3374 if (cid >= 0) 3375 goto end; 3376 raw_spin_lock(&cid_lock); 3377 } else { 3378 raw_spin_lock(&cid_lock); 3379 cid = __mm_cid_try_get(mm); 3380 if (cid >= 0) 3381 goto unlock; 3382 } 3383 3384 /* 3385 * cid concurrently allocated. Retry while forcing following 3386 * allocations to use the cid_lock to ensure forward progress. 3387 */ 3388 WRITE_ONCE(use_cid_lock, 1); 3389 /* 3390 * Set use_cid_lock before allocation. Only care about program order 3391 * because this is only required for forward progress. 3392 */ 3393 barrier(); 3394 /* 3395 * Retry until it succeeds. It is guaranteed to eventually succeed once 3396 * all newcoming allocations observe the use_cid_lock flag set. 3397 */ 3398 do { 3399 cid = __mm_cid_try_get(mm); 3400 cpu_relax(); 3401 } while (cid < 0); 3402 /* 3403 * Allocate before clearing use_cid_lock. Only care about 3404 * program order because this is for forward progress. 3405 */ 3406 barrier(); 3407 WRITE_ONCE(use_cid_lock, 0); 3408 unlock: 3409 raw_spin_unlock(&cid_lock); 3410 end: 3411 mm_cid_snapshot_time(rq, mm); 3412 return cid; 3413 } 3414 3415 static inline int mm_cid_get(struct rq *rq, struct mm_struct *mm) 3416 { 3417 struct mm_cid __percpu *pcpu_cid = mm->pcpu_cid; 3418 struct cpumask *cpumask; 3419 int cid; 3420 3421 lockdep_assert_rq_held(rq); 3422 cpumask = mm_cidmask(mm); 3423 cid = __this_cpu_read(pcpu_cid->cid); 3424 if (mm_cid_is_valid(cid)) { 3425 mm_cid_snapshot_time(rq, mm); 3426 return cid; 3427 } 3428 if (mm_cid_is_lazy_put(cid)) { 3429 if (try_cmpxchg(&this_cpu_ptr(pcpu_cid)->cid, &cid, MM_CID_UNSET)) 3430 __mm_cid_put(mm, mm_cid_clear_lazy_put(cid)); 3431 } 3432 cid = __mm_cid_get(rq, mm); 3433 __this_cpu_write(pcpu_cid->cid, cid); 3434 return cid; 3435 } 3436 3437 static inline void switch_mm_cid(struct rq *rq, 3438 struct task_struct *prev, 3439 struct task_struct *next) 3440 { 3441 /* 3442 * Provide a memory barrier between rq->curr store and load of 3443 * {prev,next}->mm->pcpu_cid[cpu] on rq->curr->mm transition. 3444 * 3445 * Should be adapted if context_switch() is modified. 3446 */ 3447 if (!next->mm) { // to kernel 3448 /* 3449 * user -> kernel transition does not guarantee a barrier, but 3450 * we can use the fact that it performs an atomic operation in 3451 * mmgrab(). 3452 */ 3453 if (prev->mm) // from user 3454 smp_mb__after_mmgrab(); 3455 /* 3456 * kernel -> kernel transition does not change rq->curr->mm 3457 * state. It stays NULL. 3458 */ 3459 } else { // to user 3460 /* 3461 * kernel -> user transition does not provide a barrier 3462 * between rq->curr store and load of {prev,next}->mm->pcpu_cid[cpu]. 3463 * Provide it here. 3464 */ 3465 if (!prev->mm) // from kernel 3466 smp_mb(); 3467 /* 3468 * user -> user transition guarantees a memory barrier through 3469 * switch_mm() when current->mm changes. If current->mm is 3470 * unchanged, no barrier is needed. 3471 */ 3472 } 3473 if (prev->mm_cid_active) { 3474 mm_cid_snapshot_time(rq, prev->mm); 3475 mm_cid_put_lazy(prev); 3476 prev->mm_cid = -1; 3477 } 3478 if (next->mm_cid_active) 3479 next->last_mm_cid = next->mm_cid = mm_cid_get(rq, next->mm); 3480 } 3481 3482 #else 3483 static inline void switch_mm_cid(struct rq *rq, struct task_struct *prev, struct task_struct *next) { } 3484 static inline void sched_mm_cid_migrate_from(struct task_struct *t) { } 3485 static inline void sched_mm_cid_migrate_to(struct rq *dst_rq, struct task_struct *t) { } 3486 static inline void task_tick_mm_cid(struct rq *rq, struct task_struct *curr) { } 3487 static inline void init_sched_mm_cid(struct task_struct *t) { } 3488 #endif 3489 3490 #endif /* _KERNEL_SCHED_SCHED_H */ 3491