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/prandom.h> 9 #include <linux/sched/affinity.h> 10 #include <linux/sched/autogroup.h> 11 #include <linux/sched/cpufreq.h> 12 #include <linux/sched/deadline.h> 13 #include <linux/sched.h> 14 #include <linux/sched/loadavg.h> 15 #include <linux/sched/mm.h> 16 #include <linux/sched/rseq_api.h> 17 #include <linux/sched/signal.h> 18 #include <linux/sched/smt.h> 19 #include <linux/sched/stat.h> 20 #include <linux/sched/sysctl.h> 21 #include <linux/sched/task_flags.h> 22 #include <linux/sched/task.h> 23 #include <linux/sched/topology.h> 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/cpuset.h> 34 #include <linux/ctype.h> 35 #include <linux/file.h> 36 #include <linux/fs_api.h> 37 #include <linux/hrtimer_api.h> 38 #include <linux/interrupt.h> 39 #include <linux/irq_work.h> 40 #include <linux/jiffies.h> 41 #include <linux/kref_api.h> 42 #include <linux/kthread.h> 43 #include <linux/ktime_api.h> 44 #include <linux/lockdep_api.h> 45 #include <linux/lockdep.h> 46 #include <linux/memblock.h> 47 #include <linux/memcontrol.h> 48 #include <linux/minmax.h> 49 #include <linux/mm.h> 50 #include <linux/module.h> 51 #include <linux/mutex_api.h> 52 #include <linux/plist.h> 53 #include <linux/poll.h> 54 #include <linux/proc_fs.h> 55 #include <linux/profile.h> 56 #include <linux/psi.h> 57 #include <linux/rcupdate.h> 58 #include <linux/seq_file.h> 59 #include <linux/seqlock.h> 60 #include <linux/softirq.h> 61 #include <linux/spinlock_api.h> 62 #include <linux/static_key.h> 63 #include <linux/stop_machine.h> 64 #include <linux/syscalls_api.h> 65 #include <linux/syscalls.h> 66 #include <linux/tick.h> 67 #include <linux/topology.h> 68 #include <linux/types.h> 69 #include <linux/u64_stats_sync_api.h> 70 #include <linux/uaccess.h> 71 #include <linux/vmstat.h> 72 #include <linux/wait_api.h> 73 #include <linux/wait_bit.h> 74 #include <linux/workqueue_api.h> 75 #include <linux/delayacct.h> 76 #include <linux/mmu_context.h> 77 78 #include <trace/events/power.h> 79 #include <trace/events/sched.h> 80 81 #include "../workqueue_internal.h" 82 83 struct rq; 84 struct cfs_rq; 85 struct rt_rq; 86 struct sched_group; 87 struct cpuidle_state; 88 89 #if defined(CONFIG_PARAVIRT) && !defined(CONFIG_HAVE_PV_STEAL_CLOCK_GEN) 90 # include <asm/paravirt.h> 91 #endif 92 93 #include <asm/barrier.h> 94 95 #include "cpupri.h" 96 #include "cpudeadline.h" 97 98 /* task_struct::on_rq states: */ 99 #define TASK_ON_RQ_QUEUED 1 100 #define TASK_ON_RQ_MIGRATING 2 101 102 extern __read_mostly int scheduler_running; 103 104 extern unsigned long calc_load_update; 105 extern atomic_long_t calc_load_tasks; 106 107 extern void calc_global_load_tick(struct rq *this_rq); 108 extern long calc_load_fold_active(struct rq *this_rq, long adjust); 109 110 extern void call_trace_sched_update_nr_running(struct rq *rq, int count); 111 112 extern int sysctl_sched_rt_period; 113 extern int sysctl_sched_rt_runtime; 114 extern int sched_rr_timeslice; 115 116 /* 117 * Asymmetric CPU capacity bits 118 */ 119 struct asym_cap_data { 120 struct list_head link; 121 struct rcu_head rcu; 122 unsigned long capacity; 123 unsigned long cpus[]; 124 }; 125 126 extern struct list_head asym_cap_list; 127 128 #define cpu_capacity_span(asym_data) to_cpumask((asym_data)->cpus) 129 130 /* 131 * Helpers for converting nanosecond timing to jiffy resolution 132 */ 133 #define NS_TO_JIFFIES(time) ((unsigned long)(time) / (NSEC_PER_SEC/HZ)) 134 135 /* 136 * Increase resolution of nice-level calculations for 64-bit architectures. 137 * The extra resolution improves shares distribution and load balancing of 138 * low-weight task groups (eg. nice +19 on an autogroup), deeper task-group 139 * hierarchies, especially on larger systems. This is not a user-visible change 140 * and does not change the user-interface for setting shares/weights. 141 * 142 * We increase resolution only if we have enough bits to allow this increased 143 * resolution (i.e. 64-bit). The costs for increasing resolution when 32-bit 144 * are pretty high and the returns do not justify the increased costs. 145 * 146 * Really only required when CONFIG_FAIR_GROUP_SCHED=y is also set, but to 147 * increase coverage and consistency always enable it on 64-bit platforms. 148 */ 149 #ifdef CONFIG_64BIT 150 # define NICE_0_LOAD_SHIFT (SCHED_FIXEDPOINT_SHIFT + SCHED_FIXEDPOINT_SHIFT) 151 # define scale_load(w) ((w) << SCHED_FIXEDPOINT_SHIFT) 152 # define scale_load_down(w) \ 153 ({ \ 154 unsigned long __w = (w); \ 155 \ 156 if (__w) \ 157 __w = max(2UL, __w >> SCHED_FIXEDPOINT_SHIFT); \ 158 __w; \ 159 }) 160 #else 161 # define NICE_0_LOAD_SHIFT (SCHED_FIXEDPOINT_SHIFT) 162 # define scale_load(w) (w) 163 # define scale_load_down(w) (w) 164 #endif 165 166 /* 167 * Task weight (visible to users) and its load (invisible to users) have 168 * independent resolution, but they should be well calibrated. We use 169 * scale_load() and scale_load_down(w) to convert between them. The 170 * following must be true: 171 * 172 * scale_load(sched_prio_to_weight[NICE_TO_PRIO(0)-MAX_RT_PRIO]) == NICE_0_LOAD 173 * 174 */ 175 #define NICE_0_LOAD (1L << NICE_0_LOAD_SHIFT) 176 177 /* 178 * Single value that decides SCHED_DEADLINE internal math precision. 179 * 10 -> just above 1us 180 * 9 -> just above 0.5us 181 */ 182 #define DL_SCALE 10 183 184 /* 185 * Single value that denotes runtime == period, ie unlimited time. 186 */ 187 #define RUNTIME_INF ((u64)~0ULL) 188 189 static inline int idle_policy(int policy) 190 { 191 return policy == SCHED_IDLE; 192 } 193 194 static inline int normal_policy(int policy) 195 { 196 #ifdef CONFIG_SCHED_CLASS_EXT 197 if (policy == SCHED_EXT) 198 return true; 199 #endif 200 return policy == SCHED_NORMAL; 201 } 202 203 static inline int fair_policy(int policy) 204 { 205 return normal_policy(policy) || policy == SCHED_BATCH; 206 } 207 208 static inline int rt_policy(int policy) 209 { 210 return policy == SCHED_FIFO || policy == SCHED_RR; 211 } 212 213 static inline int dl_policy(int policy) 214 { 215 return policy == SCHED_DEADLINE; 216 } 217 218 static inline bool valid_policy(int policy) 219 { 220 return idle_policy(policy) || fair_policy(policy) || 221 rt_policy(policy) || dl_policy(policy); 222 } 223 224 static inline int task_has_idle_policy(struct task_struct *p) 225 { 226 return idle_policy(p->policy); 227 } 228 229 static inline int task_has_rt_policy(struct task_struct *p) 230 { 231 return rt_policy(p->policy); 232 } 233 234 static inline int task_has_dl_policy(struct task_struct *p) 235 { 236 return dl_policy(p->policy); 237 } 238 239 #define cap_scale(v, s) ((v)*(s) >> SCHED_CAPACITY_SHIFT) 240 241 static inline void update_avg(u64 *avg, u64 sample) 242 { 243 s64 diff = sample - *avg; 244 245 *avg += diff / 8; 246 } 247 248 /* 249 * Shifting a value by an exponent greater *or equal* to the size of said value 250 * is UB; cap at size-1. 251 */ 252 #define shr_bound(val, shift) \ 253 (val >> min_t(typeof(shift), shift, BITS_PER_TYPE(typeof(val)) - 1)) 254 255 /* 256 * cgroup weight knobs should use the common MIN, DFL and MAX values which are 257 * 1, 100 and 10000 respectively. While it loses a bit of range on both ends, it 258 * maps pretty well onto the shares value used by scheduler and the round-trip 259 * conversions preserve the original value over the entire range. 260 */ 261 static inline unsigned long sched_weight_from_cgroup(unsigned long cgrp_weight) 262 { 263 return DIV_ROUND_CLOSEST_ULL(cgrp_weight * 1024, CGROUP_WEIGHT_DFL); 264 } 265 266 static inline unsigned long sched_weight_to_cgroup(unsigned long weight) 267 { 268 return clamp_t(unsigned long, 269 DIV_ROUND_CLOSEST_ULL(weight * CGROUP_WEIGHT_DFL, 1024), 270 CGROUP_WEIGHT_MIN, CGROUP_WEIGHT_MAX); 271 } 272 273 /* 274 * !! For sched_setattr_nocheck() (kernel) only !! 275 * 276 * This is actually gross. :( 277 * 278 * It is used to make schedutil kworker(s) higher priority than SCHED_DEADLINE 279 * tasks, but still be able to sleep. We need this on platforms that cannot 280 * atomically change clock frequency. Remove once fast switching will be 281 * available on such platforms. 282 * 283 * SUGOV stands for SchedUtil GOVernor. 284 */ 285 #define SCHED_FLAG_SUGOV 0x10000000 286 287 #define SCHED_DL_FLAGS (SCHED_FLAG_RECLAIM | SCHED_FLAG_DL_OVERRUN | SCHED_FLAG_SUGOV) 288 289 static inline bool dl_entity_is_special(const struct sched_dl_entity *dl_se) 290 { 291 #ifdef CONFIG_CPU_FREQ_GOV_SCHEDUTIL 292 return unlikely(dl_se->flags & SCHED_FLAG_SUGOV); 293 #else 294 return false; 295 #endif 296 } 297 298 /* 299 * Tells if entity @a should preempt entity @b. 300 */ 301 static inline bool dl_entity_preempt(const struct sched_dl_entity *a, 302 const struct sched_dl_entity *b) 303 { 304 return dl_entity_is_special(a) || 305 dl_time_before(a->deadline, b->deadline); 306 } 307 308 /* 309 * This is the priority-queue data structure of the RT scheduling class: 310 */ 311 struct rt_prio_array { 312 DECLARE_BITMAP(bitmap, MAX_RT_PRIO+1); /* include 1 bit for delimiter */ 313 struct list_head queue[MAX_RT_PRIO]; 314 }; 315 316 struct rt_bandwidth { 317 /* nests inside the rq lock: */ 318 raw_spinlock_t rt_runtime_lock; 319 ktime_t rt_period; 320 u64 rt_runtime; 321 struct hrtimer rt_period_timer; 322 unsigned int rt_period_active; 323 }; 324 325 static inline int dl_bandwidth_enabled(void) 326 { 327 return sysctl_sched_rt_runtime >= 0; 328 } 329 330 /* 331 * To keep the bandwidth of -deadline tasks under control 332 * we need some place where: 333 * - store the maximum -deadline bandwidth of each cpu; 334 * - cache the fraction of bandwidth that is currently allocated in 335 * each root domain; 336 * 337 * This is all done in the data structure below. It is similar to the 338 * one used for RT-throttling (rt_bandwidth), with the main difference 339 * that, since here we are only interested in admission control, we 340 * do not decrease any runtime while the group "executes", neither we 341 * need a timer to replenish it. 342 * 343 * With respect to SMP, bandwidth is given on a per root domain basis, 344 * meaning that: 345 * - bw (< 100%) is the deadline bandwidth of each CPU; 346 * - total_bw is the currently allocated bandwidth in each root domain; 347 */ 348 struct dl_bw { 349 raw_spinlock_t lock; 350 u64 bw; 351 u64 total_bw; 352 }; 353 354 extern void init_dl_bw(struct dl_bw *dl_b); 355 extern int sched_dl_global_validate(void); 356 extern void sched_dl_do_global(void); 357 extern int sched_dl_overflow(struct task_struct *p, int policy, const struct sched_attr *attr); 358 extern void __setparam_dl(struct task_struct *p, const struct sched_attr *attr); 359 extern void __getparam_dl(struct task_struct *p, struct sched_attr *attr); 360 extern bool __checkparam_dl(const struct sched_attr *attr); 361 extern bool dl_param_changed(struct task_struct *p, const struct sched_attr *attr); 362 extern int dl_cpuset_cpumask_can_shrink(const struct cpumask *cur, const struct cpumask *trial); 363 extern int dl_bw_deactivate(int cpu); 364 extern s64 dl_scaled_delta_exec(struct rq *rq, struct sched_dl_entity *dl_se, s64 delta_exec); 365 /* 366 * SCHED_DEADLINE supports servers (nested scheduling) with the following 367 * interface: 368 * 369 * dl_se::rq -- runqueue we belong to. 370 * 371 * dl_se::server_pick() -- nested pick_next_task(); we yield the period if this 372 * returns NULL. 373 * 374 * dl_server_update() -- called from update_curr_common(), propagates runtime 375 * to the server. 376 * 377 * dl_server_start() -- start the server when it has tasks; it will stop 378 * automatically when there are no more tasks, per 379 * dl_se::server_pick() returning NULL. 380 * 381 * dl_server_stop() -- (force) stop the server; use when updating 382 * parameters. 383 * 384 * dl_server_init() -- initializes the server. 385 * 386 * When started the dl_server will (per dl_defer) schedule a timer for its 387 * zero-laxity point -- that is, unlike regular EDF tasks which run ASAP, a 388 * server will run at the very end of its period. 389 * 390 * This is done such that any runtime from the target class can be accounted 391 * against the server -- through dl_server_update() above -- such that when it 392 * becomes time to run, it might already be out of runtime and get deferred 393 * until the next period. In this case dl_server_timer() will alternate 394 * between defer and replenish but never actually enqueue the server. 395 * 396 * Only when the target class does not manage to exhaust the server's runtime 397 * (there's actualy starvation in the given period), will the dl_server get on 398 * the runqueue. Once queued it will pick tasks from the target class and run 399 * them until either its runtime is exhaused, at which point its back to 400 * dl_server_timer, or until there are no more tasks to run, at which point 401 * the dl_server stops itself. 402 * 403 * By stopping at this point the dl_server retains bandwidth, which, if a new 404 * task wakes up imminently (starting the server again), can be used -- 405 * subject to CBS wakeup rules -- without having to wait for the next period. 406 * 407 * Additionally, because of the dl_defer behaviour the start/stop behaviour is 408 * naturally thottled to once per period, avoiding high context switch 409 * workloads from spamming the hrtimer program/cancel paths. 410 */ 411 extern void dl_server_update_idle(struct sched_dl_entity *dl_se, s64 delta_exec); 412 extern void dl_server_update(struct sched_dl_entity *dl_se, s64 delta_exec); 413 extern void dl_server_start(struct sched_dl_entity *dl_se); 414 extern void dl_server_stop(struct sched_dl_entity *dl_se); 415 extern void dl_server_init(struct sched_dl_entity *dl_se, struct rq *rq, 416 dl_server_pick_f pick_task); 417 extern void sched_init_dl_servers(void); 418 419 extern void fair_server_init(struct rq *rq); 420 extern void ext_server_init(struct rq *rq); 421 extern void __dl_server_attach_root(struct sched_dl_entity *dl_se, struct rq *rq); 422 extern int dl_server_apply_params(struct sched_dl_entity *dl_se, 423 u64 runtime, u64 period, bool init); 424 425 static inline bool dl_server_active(struct sched_dl_entity *dl_se) 426 { 427 return dl_se->dl_server_active; 428 } 429 430 #ifdef CONFIG_CGROUP_SCHED 431 432 extern struct list_head task_groups; 433 434 #ifdef CONFIG_GROUP_SCHED_BANDWIDTH 435 extern const u64 max_bw_quota_period_us; 436 437 /* 438 * default period for group bandwidth. 439 * default: 0.1s, units: microseconds 440 */ 441 static inline u64 default_bw_period_us(void) 442 { 443 return 100000ULL; 444 } 445 #endif /* CONFIG_GROUP_SCHED_BANDWIDTH */ 446 447 struct cfs_bandwidth { 448 #ifdef CONFIG_CFS_BANDWIDTH 449 raw_spinlock_t lock; 450 ktime_t period; 451 u64 quota; 452 u64 runtime; 453 u64 burst; 454 u64 runtime_snap; 455 s64 hierarchical_quota; 456 457 u8 idle; 458 u8 period_active; 459 u8 slack_started; 460 struct hrtimer period_timer; 461 struct hrtimer slack_timer; 462 struct list_head throttled_cfs_rq; 463 464 /* Statistics: */ 465 int nr_periods; 466 int nr_throttled; 467 int nr_burst; 468 u64 throttled_time; 469 u64 burst_time; 470 #endif /* CONFIG_CFS_BANDWIDTH */ 471 }; 472 473 /* Task group related information */ 474 struct task_group { 475 struct cgroup_subsys_state css; 476 477 #ifdef CONFIG_GROUP_SCHED_WEIGHT 478 /* A positive value indicates that this is a SCHED_IDLE group. */ 479 int idle; 480 #endif 481 482 #ifdef CONFIG_FAIR_GROUP_SCHED 483 /* schedulable entities of this group on each CPU */ 484 struct sched_entity **se; 485 /* runqueue "owned" by this group on each CPU */ 486 struct cfs_rq **cfs_rq; 487 unsigned long shares; 488 /* 489 * load_avg can be heavily contended at clock tick time, so put 490 * it in its own cache-line separated from the fields above which 491 * will also be accessed at each tick. 492 */ 493 atomic_long_t load_avg ____cacheline_aligned; 494 #endif /* CONFIG_FAIR_GROUP_SCHED */ 495 496 #ifdef CONFIG_RT_GROUP_SCHED 497 struct sched_rt_entity **rt_se; 498 struct rt_rq **rt_rq; 499 500 struct rt_bandwidth rt_bandwidth; 501 #endif 502 503 struct scx_task_group scx; 504 505 struct rcu_head rcu; 506 struct list_head list; 507 508 struct task_group *parent; 509 struct list_head siblings; 510 struct list_head children; 511 512 #ifdef CONFIG_SCHED_AUTOGROUP 513 struct autogroup *autogroup; 514 #endif 515 516 struct cfs_bandwidth cfs_bandwidth; 517 518 #ifdef CONFIG_UCLAMP_TASK_GROUP 519 /* The two decimal precision [%] value requested from user-space */ 520 unsigned int uclamp_pct[UCLAMP_CNT]; 521 /* Clamp values requested for a task group */ 522 struct uclamp_se uclamp_req[UCLAMP_CNT]; 523 /* Effective clamp values used for a task group */ 524 struct uclamp_se uclamp[UCLAMP_CNT]; 525 #endif 526 527 }; 528 529 #ifdef CONFIG_GROUP_SCHED_WEIGHT 530 #define ROOT_TASK_GROUP_LOAD NICE_0_LOAD 531 532 /* 533 * A weight of 0 or 1 can cause arithmetics problems. 534 * A weight of a cfs_rq is the sum of weights of which entities 535 * are queued on this cfs_rq, so a weight of a entity should not be 536 * too large, so as the shares value of a task group. 537 * (The default weight is 1024 - so there's no practical 538 * limitation from this.) 539 */ 540 #define MIN_SHARES (1UL << 1) 541 #define MAX_SHARES (1UL << 18) 542 #endif 543 544 typedef int (*tg_visitor)(struct task_group *, void *); 545 546 extern int walk_tg_tree_from(struct task_group *from, 547 tg_visitor down, tg_visitor up, void *data); 548 549 /* 550 * Iterate the full tree, calling @down when first entering a node and @up when 551 * leaving it for the final time. 552 * 553 * Caller must hold rcu_lock or sufficient equivalent. 554 */ 555 static inline int walk_tg_tree(tg_visitor down, tg_visitor up, void *data) 556 { 557 return walk_tg_tree_from(&root_task_group, down, up, data); 558 } 559 560 static inline struct task_group *css_tg(struct cgroup_subsys_state *css) 561 { 562 return css ? container_of(css, struct task_group, css) : NULL; 563 } 564 565 extern int tg_nop(struct task_group *tg, void *data); 566 567 #ifdef CONFIG_FAIR_GROUP_SCHED 568 extern void free_fair_sched_group(struct task_group *tg); 569 extern int alloc_fair_sched_group(struct task_group *tg, struct task_group *parent); 570 extern void online_fair_sched_group(struct task_group *tg); 571 extern void unregister_fair_sched_group(struct task_group *tg); 572 #else /* !CONFIG_FAIR_GROUP_SCHED: */ 573 static inline void free_fair_sched_group(struct task_group *tg) { } 574 static inline int alloc_fair_sched_group(struct task_group *tg, struct task_group *parent) 575 { 576 return 1; 577 } 578 static inline void online_fair_sched_group(struct task_group *tg) { } 579 static inline void unregister_fair_sched_group(struct task_group *tg) { } 580 #endif /* !CONFIG_FAIR_GROUP_SCHED */ 581 582 extern void init_tg_cfs_entry(struct task_group *tg, struct cfs_rq *cfs_rq, 583 struct sched_entity *se, int cpu, 584 struct sched_entity *parent); 585 extern void init_cfs_bandwidth(struct cfs_bandwidth *cfs_b, struct cfs_bandwidth *parent); 586 587 extern void __refill_cfs_bandwidth_runtime(struct cfs_bandwidth *cfs_b); 588 extern void start_cfs_bandwidth(struct cfs_bandwidth *cfs_b); 589 extern void unthrottle_cfs_rq(struct cfs_rq *cfs_rq); 590 extern bool cfs_task_bw_constrained(struct task_struct *p); 591 592 extern void init_tg_rt_entry(struct task_group *tg, struct rt_rq *rt_rq, 593 struct sched_rt_entity *rt_se, int cpu, 594 struct sched_rt_entity *parent); 595 extern int sched_group_set_rt_runtime(struct task_group *tg, long rt_runtime_us); 596 extern int sched_group_set_rt_period(struct task_group *tg, u64 rt_period_us); 597 extern long sched_group_rt_runtime(struct task_group *tg); 598 extern long sched_group_rt_period(struct task_group *tg); 599 extern int sched_rt_can_attach(struct task_group *tg, struct task_struct *tsk); 600 601 extern struct task_group *sched_create_group(struct task_group *parent); 602 extern void sched_online_group(struct task_group *tg, 603 struct task_group *parent); 604 extern void sched_destroy_group(struct task_group *tg); 605 extern void sched_release_group(struct task_group *tg); 606 607 extern void sched_move_task(struct task_struct *tsk, bool for_autogroup); 608 609 #ifdef CONFIG_FAIR_GROUP_SCHED 610 extern int sched_group_set_shares(struct task_group *tg, unsigned long shares); 611 612 extern int sched_group_set_idle(struct task_group *tg, long idle); 613 614 extern void set_task_rq_fair(struct sched_entity *se, 615 struct cfs_rq *prev, struct cfs_rq *next); 616 #else /* !CONFIG_FAIR_GROUP_SCHED: */ 617 static inline int sched_group_set_shares(struct task_group *tg, unsigned long shares) { return 0; } 618 static inline int sched_group_set_idle(struct task_group *tg, long idle) { return 0; } 619 #endif /* !CONFIG_FAIR_GROUP_SCHED */ 620 621 #else /* !CONFIG_CGROUP_SCHED: */ 622 623 struct cfs_bandwidth { }; 624 625 static inline bool cfs_task_bw_constrained(struct task_struct *p) { return false; } 626 627 #endif /* !CONFIG_CGROUP_SCHED */ 628 629 extern void unregister_rt_sched_group(struct task_group *tg); 630 extern void free_rt_sched_group(struct task_group *tg); 631 extern int alloc_rt_sched_group(struct task_group *tg, struct task_group *parent); 632 633 /* 634 * u64_u32_load/u64_u32_store 635 * 636 * Use a copy of a u64 value to protect against data race. This is only 637 * applicable for 32-bits architectures. 638 */ 639 #ifdef CONFIG_64BIT 640 # define u64_u32_load_copy(var, copy) var 641 # define u64_u32_store_copy(var, copy, val) (var = val) 642 #else 643 # define u64_u32_load_copy(var, copy) \ 644 ({ \ 645 u64 __val, __val_copy; \ 646 do { \ 647 __val_copy = copy; \ 648 /* \ 649 * paired with u64_u32_store_copy(), ordering access \ 650 * to var and copy. \ 651 */ \ 652 smp_rmb(); \ 653 __val = var; \ 654 } while (__val != __val_copy); \ 655 __val; \ 656 }) 657 # define u64_u32_store_copy(var, copy, val) \ 658 do { \ 659 typeof(val) __val = (val); \ 660 var = __val; \ 661 /* \ 662 * paired with u64_u32_load_copy(), ordering access to var and \ 663 * copy. \ 664 */ \ 665 smp_wmb(); \ 666 copy = __val; \ 667 } while (0) 668 #endif 669 # define u64_u32_load(var) u64_u32_load_copy(var, var##_copy) 670 # define u64_u32_store(var, val) u64_u32_store_copy(var, var##_copy, val) 671 672 struct balance_callback { 673 struct balance_callback *next; 674 void (*func)(struct rq *rq); 675 }; 676 677 /* Fair scheduling SCHED_{NORMAL,BATCH,IDLE} related fields in a runqueue: */ 678 struct cfs_rq { 679 struct load_weight load; 680 unsigned int nr_queued; 681 unsigned int h_nr_queued; /* SCHED_{NORMAL,BATCH,IDLE} */ 682 unsigned int h_nr_runnable; /* SCHED_{NORMAL,BATCH,IDLE} */ 683 unsigned int h_nr_idle; /* SCHED_IDLE */ 684 685 s64 sum_w_vruntime; 686 u64 sum_weight; 687 688 u64 zero_vruntime; 689 #ifdef CONFIG_SCHED_CORE 690 unsigned int forceidle_seq; 691 u64 zero_vruntime_fi; 692 #endif 693 694 struct rb_root_cached tasks_timeline; 695 696 /* 697 * 'curr' points to the currently running entity on this cfs_rq. 698 * It is set to NULL otherwise (i.e when none are currently running). 699 */ 700 struct sched_entity *curr; 701 struct sched_entity *next; 702 703 /* 704 * CFS load tracking 705 */ 706 struct sched_avg avg; 707 #ifndef CONFIG_64BIT 708 u64 last_update_time_copy; 709 #endif 710 struct { 711 raw_spinlock_t lock ____cacheline_aligned; 712 int nr; 713 unsigned long load_avg; 714 unsigned long util_avg; 715 unsigned long runnable_avg; 716 } removed; 717 718 #ifdef CONFIG_FAIR_GROUP_SCHED 719 u64 last_update_tg_load_avg; 720 unsigned long tg_load_avg_contrib; 721 long propagate; 722 long prop_runnable_sum; 723 724 /* 725 * h_load = weight * f(tg) 726 * 727 * Where f(tg) is the recursive weight fraction assigned to 728 * this group. 729 */ 730 unsigned long h_load; 731 u64 last_h_load_update; 732 struct sched_entity *h_load_next; 733 734 struct rq *rq; /* CPU runqueue to which this cfs_rq is attached */ 735 736 /* 737 * leaf cfs_rqs are those that hold tasks (lowest schedulable entity in 738 * a hierarchy). Non-leaf lrqs hold other higher schedulable entities 739 * (like users, containers etc.) 740 * 741 * leaf_cfs_rq_list ties together list of leaf cfs_rq's in a CPU. 742 * This list is used during load balance. 743 */ 744 int on_list; 745 struct list_head leaf_cfs_rq_list; 746 struct task_group *tg; /* Group that "owns" this runqueue */ 747 748 /* Locally cached copy of our task_group's idle value */ 749 int idle; 750 751 # ifdef CONFIG_CFS_BANDWIDTH 752 int runtime_enabled; 753 s64 runtime_remaining; 754 755 u64 throttled_pelt_idle; 756 # ifndef CONFIG_64BIT 757 u64 throttled_pelt_idle_copy; 758 # endif 759 u64 throttled_clock; 760 u64 throttled_clock_pelt; 761 u64 throttled_clock_pelt_time; 762 u64 throttled_clock_self; 763 u64 throttled_clock_self_time; 764 bool throttled:1; 765 bool pelt_clock_throttled:1; 766 int throttle_count; 767 struct list_head throttled_list; 768 struct list_head throttled_csd_list; 769 struct list_head throttled_limbo_list; 770 # endif /* CONFIG_CFS_BANDWIDTH */ 771 #endif /* CONFIG_FAIR_GROUP_SCHED */ 772 }; 773 774 #ifdef CONFIG_SCHED_CLASS_EXT 775 /* scx_rq->flags, protected by the rq lock */ 776 enum scx_rq_flags { 777 /* 778 * A hotplugged CPU starts scheduling before rq_online_scx(). Track 779 * ops.cpu_on/offline() state so that ops.enqueue/dispatch() are called 780 * only while the BPF scheduler considers the CPU to be online. 781 */ 782 SCX_RQ_ONLINE = 1 << 0, 783 SCX_RQ_CAN_STOP_TICK = 1 << 1, 784 SCX_RQ_BAL_KEEP = 1 << 3, /* balance decided to keep current */ 785 SCX_RQ_BYPASSING = 1 << 4, 786 SCX_RQ_CLK_VALID = 1 << 5, /* RQ clock is fresh and valid */ 787 SCX_RQ_BAL_CB_PENDING = 1 << 6, /* must queue a cb after dispatching */ 788 789 SCX_RQ_IN_WAKEUP = 1 << 16, 790 SCX_RQ_IN_BALANCE = 1 << 17, 791 }; 792 793 struct scx_rq { 794 struct scx_dispatch_q local_dsq; 795 struct list_head runnable_list; /* runnable tasks on this rq */ 796 struct list_head ddsp_deferred_locals; /* deferred ddsps from enq */ 797 unsigned long ops_qseq; 798 u64 extra_enq_flags; /* see move_task_to_local_dsq() */ 799 u32 nr_running; 800 u32 cpuperf_target; /* [0, SCHED_CAPACITY_SCALE] */ 801 bool cpu_released; 802 u32 flags; 803 u64 clock; /* current per-rq clock -- see scx_bpf_now() */ 804 cpumask_var_t cpus_to_kick; 805 cpumask_var_t cpus_to_kick_if_idle; 806 cpumask_var_t cpus_to_preempt; 807 cpumask_var_t cpus_to_wait; 808 cpumask_var_t cpus_to_sync; 809 bool kick_sync_pending; 810 unsigned long kick_sync; 811 local_t reenq_local_deferred; 812 struct balance_callback deferred_bal_cb; 813 struct balance_callback kick_sync_bal_cb; 814 struct irq_work deferred_irq_work; 815 struct irq_work kick_cpus_irq_work; 816 struct scx_dispatch_q bypass_dsq; 817 }; 818 #endif /* CONFIG_SCHED_CLASS_EXT */ 819 820 static inline int rt_bandwidth_enabled(void) 821 { 822 return sysctl_sched_rt_runtime >= 0; 823 } 824 825 /* RT IPI pull logic requires IRQ_WORK */ 826 #if defined(CONFIG_IRQ_WORK) && defined(CONFIG_SMP) 827 # define HAVE_RT_PUSH_IPI 828 #endif 829 830 /* Real-Time classes' related field in a runqueue: */ 831 struct rt_rq { 832 struct rt_prio_array active; 833 unsigned int rt_nr_running; 834 unsigned int rr_nr_running; 835 struct { 836 int curr; /* highest queued rt task prio */ 837 int next; /* next highest */ 838 } highest_prio; 839 bool overloaded; 840 struct plist_head pushable_tasks; 841 842 int rt_queued; 843 844 #ifdef CONFIG_RT_GROUP_SCHED 845 int rt_throttled; 846 u64 rt_time; /* consumed RT time, goes up in update_curr_rt */ 847 u64 rt_runtime; /* allotted RT time, "slice" from rt_bandwidth, RT sharing/balancing */ 848 /* Nests inside the rq lock: */ 849 raw_spinlock_t rt_runtime_lock; 850 851 unsigned int rt_nr_boosted; 852 853 struct rq *rq; /* this is always top-level rq, cache? */ 854 #endif 855 #ifdef CONFIG_CGROUP_SCHED 856 struct task_group *tg; /* this tg has "this" rt_rq on given CPU for runnable entities */ 857 #endif 858 }; 859 860 static inline bool rt_rq_is_runnable(struct rt_rq *rt_rq) 861 { 862 return rt_rq->rt_queued && rt_rq->rt_nr_running; 863 } 864 865 /* Deadline class' related fields in a runqueue */ 866 struct dl_rq { 867 /* runqueue is an rbtree, ordered by deadline */ 868 struct rb_root_cached root; 869 870 unsigned int dl_nr_running; 871 872 /* 873 * Deadline values of the currently executing and the 874 * earliest ready task on this rq. Caching these facilitates 875 * the decision whether or not a ready but not running task 876 * should migrate somewhere else. 877 */ 878 struct { 879 u64 curr; 880 u64 next; 881 } earliest_dl; 882 883 bool overloaded; 884 885 /* 886 * Tasks on this rq that can be pushed away. They are kept in 887 * an rb-tree, ordered by tasks' deadlines, with caching 888 * of the leftmost (earliest deadline) element. 889 */ 890 struct rb_root_cached pushable_dl_tasks_root; 891 892 /* 893 * "Active utilization" for this runqueue: increased when a 894 * task wakes up (becomes TASK_RUNNING) and decreased when a 895 * task blocks 896 */ 897 u64 running_bw; 898 899 /* 900 * Utilization of the tasks "assigned" to this runqueue (including 901 * the tasks that are in runqueue and the tasks that executed on this 902 * CPU and blocked). Increased when a task moves to this runqueue, and 903 * decreased when the task moves away (migrates, changes scheduling 904 * policy, or terminates). 905 * This is needed to compute the "inactive utilization" for the 906 * runqueue (inactive utilization = this_bw - running_bw). 907 */ 908 u64 this_bw; 909 u64 extra_bw; 910 911 /* 912 * Maximum available bandwidth for reclaiming by SCHED_FLAG_RECLAIM 913 * tasks of this rq. Used in calculation of reclaimable bandwidth(GRUB). 914 */ 915 u64 max_bw; 916 917 /* 918 * Inverse of the fraction of CPU utilization that can be reclaimed 919 * by the GRUB algorithm. 920 */ 921 u64 bw_ratio; 922 }; 923 924 #ifdef CONFIG_FAIR_GROUP_SCHED 925 926 /* An entity is a task if it doesn't "own" a runqueue */ 927 #define entity_is_task(se) (!se->my_q) 928 929 static inline void se_update_runnable(struct sched_entity *se) 930 { 931 if (!entity_is_task(se)) 932 se->runnable_weight = se->my_q->h_nr_runnable; 933 } 934 935 static inline long se_runnable(struct sched_entity *se) 936 { 937 if (se->sched_delayed) 938 return false; 939 940 if (entity_is_task(se)) 941 return !!se->on_rq; 942 else 943 return se->runnable_weight; 944 } 945 946 #else /* !CONFIG_FAIR_GROUP_SCHED: */ 947 948 #define entity_is_task(se) 1 949 950 static inline void se_update_runnable(struct sched_entity *se) { } 951 952 static inline long se_runnable(struct sched_entity *se) 953 { 954 if (se->sched_delayed) 955 return false; 956 957 return !!se->on_rq; 958 } 959 960 #endif /* !CONFIG_FAIR_GROUP_SCHED */ 961 962 /* 963 * XXX we want to get rid of these helpers and use the full load resolution. 964 */ 965 static inline long se_weight(struct sched_entity *se) 966 { 967 return scale_load_down(se->load.weight); 968 } 969 970 971 static inline bool sched_asym_prefer(int a, int b) 972 { 973 return arch_asym_cpu_priority(a) > arch_asym_cpu_priority(b); 974 } 975 976 struct perf_domain { 977 struct em_perf_domain *em_pd; 978 struct perf_domain *next; 979 struct rcu_head rcu; 980 }; 981 982 /* 983 * We add the notion of a root-domain which will be used to define per-domain 984 * variables. Each exclusive cpuset essentially defines an island domain by 985 * fully partitioning the member CPUs from any other cpuset. Whenever a new 986 * exclusive cpuset is created, we also create and attach a new root-domain 987 * object. 988 * 989 */ 990 struct root_domain { 991 atomic_t refcount; 992 atomic_t rto_count; 993 struct rcu_head rcu; 994 cpumask_var_t span; 995 cpumask_var_t online; 996 997 /* 998 * Indicate pullable load on at least one CPU, e.g: 999 * - More than one runnable task 1000 * - Running task is misfit 1001 */ 1002 bool overloaded; 1003 1004 /* Indicate one or more CPUs over-utilized (tipping point) */ 1005 bool overutilized; 1006 1007 /* 1008 * The bit corresponding to a CPU gets set here if such CPU has more 1009 * than one runnable -deadline task (as it is below for RT tasks). 1010 */ 1011 cpumask_var_t dlo_mask; 1012 atomic_t dlo_count; 1013 struct dl_bw dl_bw; 1014 struct cpudl cpudl; 1015 1016 /* 1017 * Indicate whether a root_domain's dl_bw has been checked or 1018 * updated. It's monotonously increasing value. 1019 * 1020 * Also, some corner cases, like 'wrap around' is dangerous, but given 1021 * that u64 is 'big enough'. So that shouldn't be a concern. 1022 */ 1023 u64 visit_cookie; 1024 1025 #ifdef HAVE_RT_PUSH_IPI 1026 /* 1027 * For IPI pull requests, loop across the rto_mask. 1028 */ 1029 struct irq_work rto_push_work; 1030 raw_spinlock_t rto_lock; 1031 /* These are only updated and read within rto_lock */ 1032 int rto_loop; 1033 int rto_cpu; 1034 /* These atomics are updated outside of a lock */ 1035 atomic_t rto_loop_next; 1036 atomic_t rto_loop_start; 1037 #endif /* HAVE_RT_PUSH_IPI */ 1038 /* 1039 * The "RT overload" flag: it gets set if a CPU has more than 1040 * one runnable RT task. 1041 */ 1042 cpumask_var_t rto_mask; 1043 struct cpupri cpupri; 1044 1045 /* 1046 * NULL-terminated list of performance domains intersecting with the 1047 * CPUs of the rd. Protected by RCU. 1048 */ 1049 struct perf_domain __rcu *pd; 1050 }; 1051 1052 extern void init_defrootdomain(void); 1053 extern int sched_init_domains(const struct cpumask *cpu_map); 1054 extern void rq_attach_root(struct rq *rq, struct root_domain *rd); 1055 extern void sched_get_rd(struct root_domain *rd); 1056 extern void sched_put_rd(struct root_domain *rd); 1057 1058 static inline int get_rd_overloaded(struct root_domain *rd) 1059 { 1060 return READ_ONCE(rd->overloaded); 1061 } 1062 1063 static inline void set_rd_overloaded(struct root_domain *rd, int status) 1064 { 1065 if (get_rd_overloaded(rd) != status) 1066 WRITE_ONCE(rd->overloaded, status); 1067 } 1068 1069 #ifdef HAVE_RT_PUSH_IPI 1070 extern void rto_push_irq_work_func(struct irq_work *work); 1071 #endif 1072 1073 #ifdef CONFIG_UCLAMP_TASK 1074 /* 1075 * struct uclamp_bucket - Utilization clamp bucket 1076 * @value: utilization clamp value for tasks on this clamp bucket 1077 * @tasks: number of RUNNABLE tasks on this clamp bucket 1078 * 1079 * Keep track of how many tasks are RUNNABLE for a given utilization 1080 * clamp value. 1081 */ 1082 struct uclamp_bucket { 1083 unsigned long value : bits_per(SCHED_CAPACITY_SCALE); 1084 unsigned long tasks : BITS_PER_LONG - bits_per(SCHED_CAPACITY_SCALE); 1085 }; 1086 1087 /* 1088 * struct uclamp_rq - rq's utilization clamp 1089 * @value: currently active clamp values for a rq 1090 * @bucket: utilization clamp buckets affecting a rq 1091 * 1092 * Keep track of RUNNABLE tasks on a rq to aggregate their clamp values. 1093 * A clamp value is affecting a rq when there is at least one task RUNNABLE 1094 * (or actually running) with that value. 1095 * 1096 * There are up to UCLAMP_CNT possible different clamp values, currently there 1097 * are only two: minimum utilization and maximum utilization. 1098 * 1099 * All utilization clamping values are MAX aggregated, since: 1100 * - for util_min: we want to run the CPU at least at the max of the minimum 1101 * utilization required by its currently RUNNABLE tasks. 1102 * - for util_max: we want to allow the CPU to run up to the max of the 1103 * maximum utilization allowed by its currently RUNNABLE tasks. 1104 * 1105 * Since on each system we expect only a limited number of different 1106 * utilization clamp values (UCLAMP_BUCKETS), use a simple array to track 1107 * the metrics required to compute all the per-rq utilization clamp values. 1108 */ 1109 struct uclamp_rq { 1110 unsigned int value; 1111 struct uclamp_bucket bucket[UCLAMP_BUCKETS]; 1112 }; 1113 1114 DECLARE_STATIC_KEY_FALSE(sched_uclamp_used); 1115 #endif /* CONFIG_UCLAMP_TASK */ 1116 1117 /* 1118 * This is the main, per-CPU runqueue data structure. 1119 * 1120 * Locking rule: those places that want to lock multiple runqueues 1121 * (such as the load balancing or the thread migration code), lock 1122 * acquire operations must be ordered by ascending &runqueue. 1123 */ 1124 struct rq { 1125 /* 1126 * The following members are loaded together, without holding the 1127 * rq->lock, in an extremely hot loop in update_sg_lb_stats() 1128 * (called from pick_next_task()). To reduce cache pollution from 1129 * this operation, they are placed together on this dedicated cache 1130 * line. Even though some of them are frequently modified, they are 1131 * loaded much more frequently than they are stored. 1132 */ 1133 unsigned int nr_running; 1134 #ifdef CONFIG_NUMA_BALANCING 1135 unsigned int nr_numa_running; 1136 unsigned int nr_preferred_running; 1137 #endif 1138 unsigned int ttwu_pending; 1139 unsigned long cpu_capacity; 1140 #ifdef CONFIG_SCHED_PROXY_EXEC 1141 struct task_struct __rcu *donor; /* Scheduling context */ 1142 struct task_struct __rcu *curr; /* Execution context */ 1143 #else 1144 union { 1145 struct task_struct __rcu *donor; /* Scheduler context */ 1146 struct task_struct __rcu *curr; /* Execution context */ 1147 }; 1148 #endif 1149 struct task_struct *idle; 1150 /* padding left here deliberately */ 1151 1152 /* 1153 * The next cacheline holds the (hot) runqueue lock, as well as 1154 * some other less performance-critical fields. 1155 */ 1156 u64 nr_switches ____cacheline_aligned; 1157 1158 /* runqueue lock: */ 1159 raw_spinlock_t __lock; 1160 1161 #ifdef CONFIG_NO_HZ_COMMON 1162 unsigned int nohz_tick_stopped; 1163 atomic_t nohz_flags; 1164 unsigned int has_blocked_load; 1165 unsigned long last_blocked_load_update_tick; 1166 call_single_data_t nohz_csd; 1167 #endif /* CONFIG_NO_HZ_COMMON */ 1168 1169 #ifdef CONFIG_UCLAMP_TASK 1170 /* Utilization clamp values based on CPU's RUNNABLE tasks */ 1171 struct uclamp_rq uclamp[UCLAMP_CNT] ____cacheline_aligned; 1172 unsigned int uclamp_flags; 1173 #define UCLAMP_FLAG_IDLE 0x01 1174 #endif 1175 1176 struct cfs_rq cfs; 1177 struct rt_rq rt; 1178 struct dl_rq dl; 1179 #ifdef CONFIG_SCHED_CLASS_EXT 1180 struct scx_rq scx; 1181 struct sched_dl_entity ext_server; 1182 #endif 1183 1184 struct sched_dl_entity fair_server; 1185 1186 #ifdef CONFIG_FAIR_GROUP_SCHED 1187 /* list of leaf cfs_rq on this CPU: */ 1188 struct list_head leaf_cfs_rq_list; 1189 struct list_head *tmp_alone_branch; 1190 #endif /* CONFIG_FAIR_GROUP_SCHED */ 1191 1192 #ifdef CONFIG_NUMA_BALANCING 1193 unsigned int numa_migrate_on; 1194 #endif 1195 /* 1196 * This is part of a global counter where only the total sum 1197 * over all CPUs matters. A task can increase this counter on 1198 * one CPU and if it got migrated afterwards it may decrease 1199 * it on another CPU. Always updated under the runqueue lock: 1200 */ 1201 unsigned long nr_uninterruptible; 1202 1203 struct sched_dl_entity *dl_server; 1204 struct task_struct *stop; 1205 const struct sched_class *next_class; 1206 unsigned long next_balance; 1207 struct mm_struct *prev_mm; 1208 1209 /* 1210 * The following fields of clock data are frequently referenced 1211 * and updated together, and should go on their own cache line. 1212 */ 1213 u64 clock_task ____cacheline_aligned; 1214 u64 clock_pelt; 1215 u64 clock; 1216 unsigned long lost_idle_time; 1217 unsigned int clock_update_flags; 1218 u64 clock_pelt_idle; 1219 u64 clock_idle; 1220 1221 #ifndef CONFIG_64BIT 1222 u64 clock_pelt_idle_copy; 1223 u64 clock_idle_copy; 1224 #endif 1225 1226 u64 last_seen_need_resched_ns; 1227 int ticks_without_resched; 1228 1229 #ifdef CONFIG_MEMBARRIER 1230 int membarrier_state; 1231 #endif 1232 1233 struct root_domain *rd; 1234 struct sched_domain __rcu *sd; 1235 1236 struct balance_callback *balance_callback; 1237 1238 unsigned char nohz_idle_balance; 1239 unsigned char idle_balance; 1240 1241 unsigned long misfit_task_load; 1242 1243 /* For active balancing */ 1244 int active_balance; 1245 int push_cpu; 1246 struct cpu_stop_work active_balance_work; 1247 1248 /* CPU of this runqueue: */ 1249 int cpu; 1250 int online; 1251 1252 struct list_head cfs_tasks; 1253 1254 struct sched_avg avg_rt; 1255 struct sched_avg avg_dl; 1256 #ifdef CONFIG_HAVE_SCHED_AVG_IRQ 1257 struct sched_avg avg_irq; 1258 #endif 1259 #ifdef CONFIG_SCHED_HW_PRESSURE 1260 struct sched_avg avg_hw; 1261 #endif 1262 u64 idle_stamp; 1263 u64 avg_idle; 1264 1265 /* This is used to determine avg_idle's max value */ 1266 u64 max_idle_balance_cost; 1267 1268 #ifdef CONFIG_HOTPLUG_CPU 1269 struct rcuwait hotplug_wait; 1270 #endif 1271 1272 #ifdef CONFIG_IRQ_TIME_ACCOUNTING 1273 u64 prev_irq_time; 1274 u64 psi_irq_time; 1275 #endif 1276 #ifdef CONFIG_PARAVIRT 1277 u64 prev_steal_time; 1278 #endif 1279 #ifdef CONFIG_PARAVIRT_TIME_ACCOUNTING 1280 u64 prev_steal_time_rq; 1281 #endif 1282 1283 /* calc_load related fields */ 1284 unsigned long calc_load_update; 1285 long calc_load_active; 1286 1287 #ifdef CONFIG_SCHED_HRTICK 1288 call_single_data_t hrtick_csd; 1289 struct hrtimer hrtick_timer; 1290 ktime_t hrtick_time; 1291 ktime_t hrtick_delay; 1292 unsigned int hrtick_sched; 1293 #endif 1294 1295 #ifdef CONFIG_SCHEDSTATS 1296 /* latency stats */ 1297 struct sched_info rq_sched_info; 1298 unsigned long long rq_cpu_time; 1299 1300 /* sys_sched_yield() stats */ 1301 unsigned int yld_count; 1302 1303 /* schedule() stats */ 1304 unsigned int sched_count; 1305 unsigned int sched_goidle; 1306 1307 /* try_to_wake_up() stats */ 1308 unsigned int ttwu_count; 1309 unsigned int ttwu_local; 1310 #endif 1311 1312 #ifdef CONFIG_CPU_IDLE 1313 /* Must be inspected within a RCU lock section */ 1314 struct cpuidle_state *idle_state; 1315 #endif 1316 1317 unsigned int nr_pinned; 1318 unsigned int push_busy; 1319 struct cpu_stop_work push_work; 1320 1321 #ifdef CONFIG_SCHED_CORE 1322 /* per rq */ 1323 struct rq *core; 1324 struct task_struct *core_pick; 1325 struct sched_dl_entity *core_dl_server; 1326 unsigned int core_enabled; 1327 unsigned int core_sched_seq; 1328 struct rb_root core_tree; 1329 1330 /* shared state -- careful with sched_core_cpu_deactivate() */ 1331 unsigned int core_task_seq; 1332 unsigned int core_pick_seq; 1333 unsigned long core_cookie; 1334 unsigned int core_forceidle_count; 1335 unsigned int core_forceidle_seq; 1336 unsigned int core_forceidle_occupation; 1337 u64 core_forceidle_start; 1338 #endif /* CONFIG_SCHED_CORE */ 1339 1340 /* Scratch cpumask to be temporarily used under rq_lock */ 1341 cpumask_var_t scratch_mask; 1342 1343 #ifdef CONFIG_CFS_BANDWIDTH 1344 call_single_data_t cfsb_csd; 1345 struct list_head cfsb_csd_list; 1346 #endif 1347 1348 atomic_t nr_iowait; 1349 } __no_randomize_layout; 1350 1351 #ifdef CONFIG_FAIR_GROUP_SCHED 1352 1353 /* CPU runqueue to which this cfs_rq is attached */ 1354 static inline struct rq *rq_of(struct cfs_rq *cfs_rq) 1355 { 1356 return cfs_rq->rq; 1357 } 1358 1359 #else /* !CONFIG_FAIR_GROUP_SCHED: */ 1360 1361 static inline struct rq *rq_of(struct cfs_rq *cfs_rq) 1362 { 1363 return container_of(cfs_rq, struct rq, cfs); 1364 } 1365 #endif /* !CONFIG_FAIR_GROUP_SCHED */ 1366 1367 static inline int cpu_of(struct rq *rq) 1368 { 1369 return rq->cpu; 1370 } 1371 1372 #define MDF_PUSH 0x01 1373 1374 static inline bool is_migration_disabled(struct task_struct *p) 1375 { 1376 return p->migration_disabled; 1377 } 1378 1379 DECLARE_PER_CPU_SHARED_ALIGNED(struct rq, runqueues); 1380 DECLARE_PER_CPU(struct rnd_state, sched_rnd_state); 1381 1382 static inline u32 sched_rng(void) 1383 { 1384 return prandom_u32_state(this_cpu_ptr(&sched_rnd_state)); 1385 } 1386 1387 static __always_inline struct rq *__this_rq(void) 1388 { 1389 return this_cpu_ptr(&runqueues); 1390 } 1391 1392 #define cpu_rq(cpu) (&per_cpu(runqueues, (cpu))) 1393 #define this_rq() __this_rq() 1394 #define task_rq(p) cpu_rq(task_cpu(p)) 1395 #define cpu_curr(cpu) (cpu_rq(cpu)->curr) 1396 #define raw_rq() raw_cpu_ptr(&runqueues) 1397 1398 static inline bool idle_rq(struct rq *rq) 1399 { 1400 return rq->curr == rq->idle && !rq->nr_running && !rq->ttwu_pending; 1401 } 1402 1403 /** 1404 * available_idle_cpu - is a given CPU idle for enqueuing work. 1405 * @cpu: the CPU in question. 1406 * 1407 * Return: 1 if the CPU is currently idle. 0 otherwise. 1408 */ 1409 static inline bool available_idle_cpu(int cpu) 1410 { 1411 if (!idle_rq(cpu_rq(cpu))) 1412 return 0; 1413 1414 if (vcpu_is_preempted(cpu)) 1415 return 0; 1416 1417 return 1; 1418 } 1419 1420 #ifdef CONFIG_SCHED_PROXY_EXEC 1421 static inline void rq_set_donor(struct rq *rq, struct task_struct *t) 1422 { 1423 rcu_assign_pointer(rq->donor, t); 1424 } 1425 #else 1426 static inline void rq_set_donor(struct rq *rq, struct task_struct *t) 1427 { 1428 /* Do nothing */ 1429 } 1430 #endif 1431 1432 #ifdef CONFIG_SCHED_CORE 1433 static inline struct cpumask *sched_group_span(struct sched_group *sg); 1434 1435 DECLARE_STATIC_KEY_FALSE(__sched_core_enabled); 1436 1437 static inline bool sched_core_enabled(struct rq *rq) 1438 { 1439 return static_branch_unlikely(&__sched_core_enabled) && rq->core_enabled; 1440 } 1441 1442 static inline bool sched_core_disabled(void) 1443 { 1444 return !static_branch_unlikely(&__sched_core_enabled); 1445 } 1446 1447 /* 1448 * Be careful with this function; not for general use. The return value isn't 1449 * stable unless you actually hold a relevant rq->__lock. 1450 */ 1451 static inline raw_spinlock_t *rq_lockp(struct rq *rq) 1452 { 1453 if (sched_core_enabled(rq)) 1454 return &rq->core->__lock; 1455 1456 return &rq->__lock; 1457 } 1458 1459 static inline raw_spinlock_t *__rq_lockp(struct rq *rq) 1460 __returns_ctx_lock(rq_lockp(rq)) /* alias them */ 1461 { 1462 if (rq->core_enabled) 1463 return &rq->core->__lock; 1464 1465 return &rq->__lock; 1466 } 1467 1468 extern bool 1469 cfs_prio_less(const struct task_struct *a, const struct task_struct *b, bool fi); 1470 1471 extern void task_vruntime_update(struct rq *rq, struct task_struct *p, bool in_fi); 1472 1473 /* 1474 * Helpers to check if the CPU's core cookie matches with the task's cookie 1475 * when core scheduling is enabled. 1476 * A special case is that the task's cookie always matches with CPU's core 1477 * cookie if the CPU is in an idle core. 1478 */ 1479 static inline bool sched_cpu_cookie_match(struct rq *rq, struct task_struct *p) 1480 { 1481 /* Ignore cookie match if core scheduler is not enabled on the CPU. */ 1482 if (!sched_core_enabled(rq)) 1483 return true; 1484 1485 return rq->core->core_cookie == p->core_cookie; 1486 } 1487 1488 static inline bool sched_core_cookie_match(struct rq *rq, struct task_struct *p) 1489 { 1490 bool idle_core = true; 1491 int cpu; 1492 1493 /* Ignore cookie match if core scheduler is not enabled on the CPU. */ 1494 if (!sched_core_enabled(rq)) 1495 return true; 1496 1497 if (rq->core->core_cookie == p->core_cookie) 1498 return true; 1499 1500 for_each_cpu(cpu, cpu_smt_mask(cpu_of(rq))) { 1501 if (!available_idle_cpu(cpu)) { 1502 idle_core = false; 1503 break; 1504 } 1505 } 1506 1507 /* 1508 * A CPU in an idle core is always the best choice for tasks with 1509 * cookies. 1510 */ 1511 return idle_core; 1512 } 1513 1514 static inline bool sched_group_cookie_match(struct rq *rq, 1515 struct task_struct *p, 1516 struct sched_group *group) 1517 { 1518 int cpu; 1519 1520 /* Ignore cookie match if core scheduler is not enabled on the CPU. */ 1521 if (!sched_core_enabled(rq)) 1522 return true; 1523 1524 for_each_cpu_and(cpu, sched_group_span(group), p->cpus_ptr) { 1525 if (sched_core_cookie_match(cpu_rq(cpu), p)) 1526 return true; 1527 } 1528 return false; 1529 } 1530 1531 static inline bool sched_core_enqueued(struct task_struct *p) 1532 { 1533 return !RB_EMPTY_NODE(&p->core_node); 1534 } 1535 1536 extern void sched_core_enqueue(struct rq *rq, struct task_struct *p); 1537 extern void sched_core_dequeue(struct rq *rq, struct task_struct *p, int flags); 1538 1539 extern void sched_core_get(void); 1540 extern void sched_core_put(void); 1541 1542 #else /* !CONFIG_SCHED_CORE: */ 1543 1544 static inline bool sched_core_enabled(struct rq *rq) 1545 { 1546 return false; 1547 } 1548 1549 static inline bool sched_core_disabled(void) 1550 { 1551 return true; 1552 } 1553 1554 static inline raw_spinlock_t *rq_lockp(struct rq *rq) 1555 { 1556 return &rq->__lock; 1557 } 1558 1559 static inline raw_spinlock_t *__rq_lockp(struct rq *rq) 1560 __returns_ctx_lock(rq_lockp(rq)) /* alias them */ 1561 { 1562 return &rq->__lock; 1563 } 1564 1565 static inline bool sched_cpu_cookie_match(struct rq *rq, struct task_struct *p) 1566 { 1567 return true; 1568 } 1569 1570 static inline bool sched_core_cookie_match(struct rq *rq, struct task_struct *p) 1571 { 1572 return true; 1573 } 1574 1575 static inline bool sched_group_cookie_match(struct rq *rq, 1576 struct task_struct *p, 1577 struct sched_group *group) 1578 { 1579 return true; 1580 } 1581 1582 #endif /* !CONFIG_SCHED_CORE */ 1583 1584 #ifdef CONFIG_RT_GROUP_SCHED 1585 # ifdef CONFIG_RT_GROUP_SCHED_DEFAULT_DISABLED 1586 DECLARE_STATIC_KEY_FALSE(rt_group_sched); 1587 static inline bool rt_group_sched_enabled(void) 1588 { 1589 return static_branch_unlikely(&rt_group_sched); 1590 } 1591 # else /* !CONFIG_RT_GROUP_SCHED_DEFAULT_DISABLED: */ 1592 DECLARE_STATIC_KEY_TRUE(rt_group_sched); 1593 static inline bool rt_group_sched_enabled(void) 1594 { 1595 return static_branch_likely(&rt_group_sched); 1596 } 1597 # endif /* !CONFIG_RT_GROUP_SCHED_DEFAULT_DISABLED */ 1598 #else /* !CONFIG_RT_GROUP_SCHED: */ 1599 # define rt_group_sched_enabled() false 1600 #endif /* !CONFIG_RT_GROUP_SCHED */ 1601 1602 static inline void lockdep_assert_rq_held(struct rq *rq) 1603 __assumes_ctx_lock(__rq_lockp(rq)) 1604 { 1605 lockdep_assert_held(__rq_lockp(rq)); 1606 } 1607 1608 extern void raw_spin_rq_lock_nested(struct rq *rq, int subclass) 1609 __acquires(__rq_lockp(rq)); 1610 1611 extern bool raw_spin_rq_trylock(struct rq *rq) 1612 __cond_acquires(true, __rq_lockp(rq)); 1613 1614 extern void raw_spin_rq_unlock(struct rq *rq) 1615 __releases(__rq_lockp(rq)); 1616 1617 static inline void raw_spin_rq_lock(struct rq *rq) 1618 __acquires(__rq_lockp(rq)) 1619 { 1620 raw_spin_rq_lock_nested(rq, 0); 1621 } 1622 1623 static inline void raw_spin_rq_lock_irq(struct rq *rq) 1624 __acquires(__rq_lockp(rq)) 1625 { 1626 local_irq_disable(); 1627 raw_spin_rq_lock(rq); 1628 } 1629 1630 static inline void raw_spin_rq_unlock_irq(struct rq *rq) 1631 __releases(__rq_lockp(rq)) 1632 { 1633 raw_spin_rq_unlock(rq); 1634 local_irq_enable(); 1635 } 1636 1637 static inline unsigned long _raw_spin_rq_lock_irqsave(struct rq *rq) 1638 __acquires(__rq_lockp(rq)) 1639 { 1640 unsigned long flags; 1641 1642 local_irq_save(flags); 1643 raw_spin_rq_lock(rq); 1644 1645 return flags; 1646 } 1647 1648 static inline void raw_spin_rq_unlock_irqrestore(struct rq *rq, unsigned long flags) 1649 __releases(__rq_lockp(rq)) 1650 { 1651 raw_spin_rq_unlock(rq); 1652 local_irq_restore(flags); 1653 } 1654 1655 #define raw_spin_rq_lock_irqsave(rq, flags) \ 1656 do { \ 1657 flags = _raw_spin_rq_lock_irqsave(rq); \ 1658 } while (0) 1659 1660 #ifdef CONFIG_SCHED_SMT 1661 extern void __update_idle_core(struct rq *rq); 1662 1663 static inline void update_idle_core(struct rq *rq) 1664 { 1665 if (static_branch_unlikely(&sched_smt_present)) 1666 __update_idle_core(rq); 1667 } 1668 1669 #else /* !CONFIG_SCHED_SMT: */ 1670 static inline void update_idle_core(struct rq *rq) { } 1671 #endif /* !CONFIG_SCHED_SMT */ 1672 1673 #ifdef CONFIG_FAIR_GROUP_SCHED 1674 1675 static inline struct task_struct *task_of(struct sched_entity *se) 1676 { 1677 WARN_ON_ONCE(!entity_is_task(se)); 1678 return container_of(se, struct task_struct, se); 1679 } 1680 1681 static inline struct cfs_rq *task_cfs_rq(struct task_struct *p) 1682 { 1683 return p->se.cfs_rq; 1684 } 1685 1686 /* runqueue on which this entity is (to be) queued */ 1687 static inline struct cfs_rq *cfs_rq_of(const struct sched_entity *se) 1688 { 1689 return se->cfs_rq; 1690 } 1691 1692 /* runqueue "owned" by this group */ 1693 static inline struct cfs_rq *group_cfs_rq(struct sched_entity *grp) 1694 { 1695 return grp->my_q; 1696 } 1697 1698 #else /* !CONFIG_FAIR_GROUP_SCHED: */ 1699 1700 #define task_of(_se) container_of(_se, struct task_struct, se) 1701 1702 static inline struct cfs_rq *task_cfs_rq(const struct task_struct *p) 1703 { 1704 return &task_rq(p)->cfs; 1705 } 1706 1707 static inline struct cfs_rq *cfs_rq_of(const struct sched_entity *se) 1708 { 1709 const struct task_struct *p = task_of(se); 1710 struct rq *rq = task_rq(p); 1711 1712 return &rq->cfs; 1713 } 1714 1715 /* runqueue "owned" by this group */ 1716 static inline struct cfs_rq *group_cfs_rq(struct sched_entity *grp) 1717 { 1718 return NULL; 1719 } 1720 1721 #endif /* !CONFIG_FAIR_GROUP_SCHED */ 1722 1723 extern void update_rq_avg_idle(struct rq *rq); 1724 extern void update_rq_clock(struct rq *rq); 1725 1726 /* 1727 * rq::clock_update_flags bits 1728 * 1729 * %RQCF_REQ_SKIP - will request skipping of clock update on the next 1730 * call to __schedule(). This is an optimisation to avoid 1731 * neighbouring rq clock updates. 1732 * 1733 * %RQCF_ACT_SKIP - is set from inside of __schedule() when skipping is 1734 * in effect and calls to update_rq_clock() are being ignored. 1735 * 1736 * %RQCF_UPDATED - is a debug flag that indicates whether a call has been 1737 * made to update_rq_clock() since the last time rq::lock was pinned. 1738 * 1739 * If inside of __schedule(), clock_update_flags will have been 1740 * shifted left (a left shift is a cheap operation for the fast path 1741 * to promote %RQCF_REQ_SKIP to %RQCF_ACT_SKIP), so you must use, 1742 * 1743 * if (rq-clock_update_flags >= RQCF_UPDATED) 1744 * 1745 * to check if %RQCF_UPDATED is set. It'll never be shifted more than 1746 * one position though, because the next rq_unpin_lock() will shift it 1747 * back. 1748 */ 1749 #define RQCF_REQ_SKIP 0x01 1750 #define RQCF_ACT_SKIP 0x02 1751 #define RQCF_UPDATED 0x04 1752 1753 static inline void assert_clock_updated(struct rq *rq) 1754 { 1755 /* 1756 * The only reason for not seeing a clock update since the 1757 * last rq_pin_lock() is if we're currently skipping updates. 1758 */ 1759 WARN_ON_ONCE(rq->clock_update_flags < RQCF_ACT_SKIP); 1760 } 1761 1762 static inline u64 rq_clock(struct rq *rq) 1763 { 1764 lockdep_assert_rq_held(rq); 1765 assert_clock_updated(rq); 1766 1767 return rq->clock; 1768 } 1769 1770 static inline u64 rq_clock_task(struct rq *rq) 1771 { 1772 lockdep_assert_rq_held(rq); 1773 assert_clock_updated(rq); 1774 1775 return rq->clock_task; 1776 } 1777 1778 static inline void rq_clock_skip_update(struct rq *rq) 1779 { 1780 lockdep_assert_rq_held(rq); 1781 rq->clock_update_flags |= RQCF_REQ_SKIP; 1782 } 1783 1784 /* 1785 * See rt task throttling, which is the only time a skip 1786 * request is canceled. 1787 */ 1788 static inline void rq_clock_cancel_skipupdate(struct rq *rq) 1789 { 1790 lockdep_assert_rq_held(rq); 1791 rq->clock_update_flags &= ~RQCF_REQ_SKIP; 1792 } 1793 1794 /* 1795 * During cpu offlining and rq wide unthrottling, we can trigger 1796 * an update_rq_clock() for several cfs and rt runqueues (Typically 1797 * when using list_for_each_entry_*) 1798 * rq_clock_start_loop_update() can be called after updating the clock 1799 * once and before iterating over the list to prevent multiple update. 1800 * After the iterative traversal, we need to call rq_clock_stop_loop_update() 1801 * to clear RQCF_ACT_SKIP of rq->clock_update_flags. 1802 */ 1803 static inline void rq_clock_start_loop_update(struct rq *rq) 1804 { 1805 lockdep_assert_rq_held(rq); 1806 WARN_ON_ONCE(rq->clock_update_flags & RQCF_ACT_SKIP); 1807 rq->clock_update_flags |= RQCF_ACT_SKIP; 1808 } 1809 1810 static inline void rq_clock_stop_loop_update(struct rq *rq) 1811 { 1812 lockdep_assert_rq_held(rq); 1813 rq->clock_update_flags &= ~RQCF_ACT_SKIP; 1814 } 1815 1816 struct rq_flags { 1817 unsigned long flags; 1818 struct pin_cookie cookie; 1819 /* 1820 * A copy of (rq::clock_update_flags & RQCF_UPDATED) for the 1821 * current pin context is stashed here in case it needs to be 1822 * restored in rq_repin_lock(). 1823 */ 1824 unsigned int clock_update_flags; 1825 }; 1826 1827 extern struct balance_callback balance_push_callback; 1828 1829 #ifdef CONFIG_SCHED_CLASS_EXT 1830 extern const struct sched_class ext_sched_class; 1831 1832 DECLARE_STATIC_KEY_FALSE(__scx_enabled); /* SCX BPF scheduler loaded */ 1833 DECLARE_STATIC_KEY_FALSE(__scx_switched_all); /* all fair class tasks on SCX */ 1834 1835 #define scx_enabled() static_branch_unlikely(&__scx_enabled) 1836 #define scx_switched_all() static_branch_unlikely(&__scx_switched_all) 1837 1838 static inline void scx_rq_clock_update(struct rq *rq, u64 clock) 1839 { 1840 if (!scx_enabled()) 1841 return; 1842 WRITE_ONCE(rq->scx.clock, clock); 1843 smp_store_release(&rq->scx.flags, rq->scx.flags | SCX_RQ_CLK_VALID); 1844 } 1845 1846 static inline void scx_rq_clock_invalidate(struct rq *rq) 1847 { 1848 if (!scx_enabled()) 1849 return; 1850 WRITE_ONCE(rq->scx.flags, rq->scx.flags & ~SCX_RQ_CLK_VALID); 1851 } 1852 1853 #else /* !CONFIG_SCHED_CLASS_EXT: */ 1854 #define scx_enabled() false 1855 #define scx_switched_all() false 1856 1857 static inline void scx_rq_clock_update(struct rq *rq, u64 clock) {} 1858 static inline void scx_rq_clock_invalidate(struct rq *rq) {} 1859 #endif /* !CONFIG_SCHED_CLASS_EXT */ 1860 1861 /* 1862 * Lockdep annotation that avoids accidental unlocks; it's like a 1863 * sticky/continuous lockdep_assert_held(). 1864 * 1865 * This avoids code that has access to 'struct rq *rq' (basically everything in 1866 * the scheduler) from accidentally unlocking the rq if they do not also have a 1867 * copy of the (on-stack) 'struct rq_flags rf'. 1868 * 1869 * Also see Documentation/locking/lockdep-design.rst. 1870 */ 1871 static inline void rq_pin_lock(struct rq *rq, struct rq_flags *rf) 1872 { 1873 rf->cookie = lockdep_pin_lock(__rq_lockp(rq)); 1874 1875 rq->clock_update_flags &= (RQCF_REQ_SKIP|RQCF_ACT_SKIP); 1876 rf->clock_update_flags = 0; 1877 WARN_ON_ONCE(rq->balance_callback && rq->balance_callback != &balance_push_callback); 1878 } 1879 1880 static inline void rq_unpin_lock(struct rq *rq, struct rq_flags *rf) 1881 { 1882 if (rq->clock_update_flags > RQCF_ACT_SKIP) 1883 rf->clock_update_flags = RQCF_UPDATED; 1884 1885 scx_rq_clock_invalidate(rq); 1886 lockdep_unpin_lock(__rq_lockp(rq), rf->cookie); 1887 } 1888 1889 static inline void rq_repin_lock(struct rq *rq, struct rq_flags *rf) 1890 { 1891 lockdep_repin_lock(__rq_lockp(rq), rf->cookie); 1892 1893 /* 1894 * Restore the value we stashed in @rf for this pin context. 1895 */ 1896 rq->clock_update_flags |= rf->clock_update_flags; 1897 } 1898 1899 #define __task_rq_lock(...) __acquire_ret(___task_rq_lock(__VA_ARGS__), __rq_lockp(__ret)) 1900 extern struct rq *___task_rq_lock(struct task_struct *p, struct rq_flags *rf) __acquires_ret; 1901 1902 #define task_rq_lock(...) __acquire_ret(_task_rq_lock(__VA_ARGS__), __rq_lockp(__ret)) 1903 extern struct rq *_task_rq_lock(struct task_struct *p, struct rq_flags *rf) 1904 __acquires(&p->pi_lock) __acquires_ret; 1905 1906 static inline void 1907 __task_rq_unlock(struct rq *rq, struct task_struct *p, struct rq_flags *rf) 1908 __releases(__rq_lockp(rq)) 1909 { 1910 rq_unpin_lock(rq, rf); 1911 raw_spin_rq_unlock(rq); 1912 } 1913 1914 static inline void 1915 task_rq_unlock(struct rq *rq, struct task_struct *p, struct rq_flags *rf) 1916 __releases(__rq_lockp(rq), &p->pi_lock) 1917 { 1918 __task_rq_unlock(rq, p, rf); 1919 raw_spin_unlock_irqrestore(&p->pi_lock, rf->flags); 1920 } 1921 1922 DEFINE_LOCK_GUARD_1(task_rq_lock, struct task_struct, 1923 _T->rq = task_rq_lock(_T->lock, &_T->rf), 1924 task_rq_unlock(_T->rq, _T->lock, &_T->rf), 1925 struct rq *rq; struct rq_flags rf) 1926 DECLARE_LOCK_GUARD_1_ATTRS(task_rq_lock, __acquires(_T->pi_lock), __releases((*(struct task_struct **)_T)->pi_lock)) 1927 #define class_task_rq_lock_constructor(_T) WITH_LOCK_GUARD_1_ATTRS(task_rq_lock, _T) 1928 1929 DEFINE_LOCK_GUARD_1(__task_rq_lock, struct task_struct, 1930 _T->rq = __task_rq_lock(_T->lock, &_T->rf), 1931 __task_rq_unlock(_T->rq, _T->lock, &_T->rf), 1932 struct rq *rq; struct rq_flags rf) 1933 1934 static inline void rq_lock_irqsave(struct rq *rq, struct rq_flags *rf) 1935 __acquires(__rq_lockp(rq)) 1936 { 1937 raw_spin_rq_lock_irqsave(rq, rf->flags); 1938 rq_pin_lock(rq, rf); 1939 } 1940 1941 static inline void rq_lock_irq(struct rq *rq, struct rq_flags *rf) 1942 __acquires(__rq_lockp(rq)) 1943 { 1944 raw_spin_rq_lock_irq(rq); 1945 rq_pin_lock(rq, rf); 1946 } 1947 1948 static inline void rq_lock(struct rq *rq, struct rq_flags *rf) 1949 __acquires(__rq_lockp(rq)) 1950 { 1951 raw_spin_rq_lock(rq); 1952 rq_pin_lock(rq, rf); 1953 } 1954 1955 static inline void rq_unlock_irqrestore(struct rq *rq, struct rq_flags *rf) 1956 __releases(__rq_lockp(rq)) 1957 { 1958 rq_unpin_lock(rq, rf); 1959 raw_spin_rq_unlock_irqrestore(rq, rf->flags); 1960 } 1961 1962 static inline void rq_unlock_irq(struct rq *rq, struct rq_flags *rf) 1963 __releases(__rq_lockp(rq)) 1964 { 1965 rq_unpin_lock(rq, rf); 1966 raw_spin_rq_unlock_irq(rq); 1967 } 1968 1969 static inline void rq_unlock(struct rq *rq, struct rq_flags *rf) 1970 __releases(__rq_lockp(rq)) 1971 { 1972 rq_unpin_lock(rq, rf); 1973 raw_spin_rq_unlock(rq); 1974 } 1975 1976 DEFINE_LOCK_GUARD_1(rq_lock, struct rq, 1977 rq_lock(_T->lock, &_T->rf), 1978 rq_unlock(_T->lock, &_T->rf), 1979 struct rq_flags rf) 1980 1981 DECLARE_LOCK_GUARD_1_ATTRS(rq_lock, __acquires(__rq_lockp(_T)), __releases(__rq_lockp(*(struct rq **)_T))); 1982 #define class_rq_lock_constructor(_T) WITH_LOCK_GUARD_1_ATTRS(rq_lock, _T) 1983 1984 DEFINE_LOCK_GUARD_1(rq_lock_irq, struct rq, 1985 rq_lock_irq(_T->lock, &_T->rf), 1986 rq_unlock_irq(_T->lock, &_T->rf), 1987 struct rq_flags rf) 1988 1989 DECLARE_LOCK_GUARD_1_ATTRS(rq_lock_irq, __acquires(__rq_lockp(_T)), __releases(__rq_lockp(*(struct rq **)_T))); 1990 #define class_rq_lock_irq_constructor(_T) WITH_LOCK_GUARD_1_ATTRS(rq_lock_irq, _T) 1991 1992 DEFINE_LOCK_GUARD_1(rq_lock_irqsave, struct rq, 1993 rq_lock_irqsave(_T->lock, &_T->rf), 1994 rq_unlock_irqrestore(_T->lock, &_T->rf), 1995 struct rq_flags rf) 1996 1997 DECLARE_LOCK_GUARD_1_ATTRS(rq_lock_irqsave, __acquires(__rq_lockp(_T)), __releases(__rq_lockp(*(struct rq **)_T))); 1998 #define class_rq_lock_irqsave_constructor(_T) WITH_LOCK_GUARD_1_ATTRS(rq_lock_irqsave, _T) 1999 2000 #define this_rq_lock_irq(...) __acquire_ret(_this_rq_lock_irq(__VA_ARGS__), __rq_lockp(__ret)) 2001 static inline struct rq *_this_rq_lock_irq(struct rq_flags *rf) __acquires_ret 2002 { 2003 struct rq *rq; 2004 2005 local_irq_disable(); 2006 rq = this_rq(); 2007 rq_lock(rq, rf); 2008 2009 return rq; 2010 } 2011 2012 #ifdef CONFIG_NUMA 2013 2014 enum numa_topology_type { 2015 NUMA_DIRECT, 2016 NUMA_GLUELESS_MESH, 2017 NUMA_BACKPLANE, 2018 }; 2019 2020 extern enum numa_topology_type sched_numa_topology_type; 2021 extern int sched_max_numa_distance; 2022 extern bool find_numa_distance(int distance); 2023 extern void sched_init_numa(int offline_node); 2024 extern void sched_update_numa(int cpu, bool online); 2025 extern void sched_domains_numa_masks_set(unsigned int cpu); 2026 extern void sched_domains_numa_masks_clear(unsigned int cpu); 2027 extern int sched_numa_find_closest(const struct cpumask *cpus, int cpu); 2028 2029 #else /* !CONFIG_NUMA: */ 2030 2031 static inline void sched_init_numa(int offline_node) { } 2032 static inline void sched_update_numa(int cpu, bool online) { } 2033 static inline void sched_domains_numa_masks_set(unsigned int cpu) { } 2034 static inline void sched_domains_numa_masks_clear(unsigned int cpu) { } 2035 2036 static inline int sched_numa_find_closest(const struct cpumask *cpus, int cpu) 2037 { 2038 return nr_cpu_ids; 2039 } 2040 2041 #endif /* !CONFIG_NUMA */ 2042 2043 #ifdef CONFIG_NUMA_BALANCING 2044 2045 /* The regions in numa_faults array from task_struct */ 2046 enum numa_faults_stats { 2047 NUMA_MEM = 0, 2048 NUMA_CPU, 2049 NUMA_MEMBUF, 2050 NUMA_CPUBUF 2051 }; 2052 2053 extern void sched_setnuma(struct task_struct *p, int node); 2054 extern int migrate_task_to(struct task_struct *p, int cpu); 2055 extern int migrate_swap(struct task_struct *p, struct task_struct *t, 2056 int cpu, int scpu); 2057 extern void init_numa_balancing(u64 clone_flags, struct task_struct *p); 2058 2059 #else /* !CONFIG_NUMA_BALANCING: */ 2060 2061 static inline void 2062 init_numa_balancing(u64 clone_flags, struct task_struct *p) 2063 { 2064 } 2065 2066 #endif /* !CONFIG_NUMA_BALANCING */ 2067 2068 static inline void 2069 queue_balance_callback(struct rq *rq, 2070 struct balance_callback *head, 2071 void (*func)(struct rq *rq)) 2072 { 2073 lockdep_assert_rq_held(rq); 2074 2075 /* 2076 * Don't (re)queue an already queued item; nor queue anything when 2077 * balance_push() is active, see the comment with 2078 * balance_push_callback. 2079 */ 2080 if (unlikely(head->next || rq->balance_callback == &balance_push_callback)) 2081 return; 2082 2083 head->func = func; 2084 head->next = rq->balance_callback; 2085 rq->balance_callback = head; 2086 } 2087 2088 #define rcu_dereference_sched_domain(p) \ 2089 rcu_dereference_all_check((p), lockdep_is_held(&sched_domains_mutex)) 2090 2091 /* 2092 * The domain tree (rq->sd) is protected by RCU's quiescent state transition. 2093 * See destroy_sched_domains: call_rcu for details. 2094 * 2095 * The domain tree of any CPU may only be accessed from within 2096 * preempt-disabled sections. 2097 */ 2098 #define for_each_domain(cpu, __sd) \ 2099 for (__sd = rcu_dereference_sched_domain(cpu_rq(cpu)->sd); \ 2100 __sd; __sd = __sd->parent) 2101 2102 /* A mask of all the SD flags that have the SDF_SHARED_CHILD metaflag */ 2103 #define SD_FLAG(name, mflags) (name * !!((mflags) & SDF_SHARED_CHILD)) | 2104 static const unsigned int SD_SHARED_CHILD_MASK = 2105 #include <linux/sched/sd_flags.h> 2106 0; 2107 #undef SD_FLAG 2108 2109 /** 2110 * highest_flag_domain - Return highest sched_domain containing flag. 2111 * @cpu: The CPU whose highest level of sched domain is to 2112 * be returned. 2113 * @flag: The flag to check for the highest sched_domain 2114 * for the given CPU. 2115 * 2116 * Returns the highest sched_domain of a CPU which contains @flag. If @flag has 2117 * the SDF_SHARED_CHILD metaflag, all the children domains also have @flag. 2118 */ 2119 static inline struct sched_domain *highest_flag_domain(int cpu, int flag) 2120 { 2121 struct sched_domain *sd, *hsd = NULL; 2122 2123 for_each_domain(cpu, sd) { 2124 if (sd->flags & flag) { 2125 hsd = sd; 2126 continue; 2127 } 2128 2129 /* 2130 * Stop the search if @flag is known to be shared at lower 2131 * levels. It will not be found further up. 2132 */ 2133 if (flag & SD_SHARED_CHILD_MASK) 2134 break; 2135 } 2136 2137 return hsd; 2138 } 2139 2140 static inline struct sched_domain *lowest_flag_domain(int cpu, int flag) 2141 { 2142 struct sched_domain *sd; 2143 2144 for_each_domain(cpu, sd) { 2145 if (sd->flags & flag) 2146 break; 2147 } 2148 2149 return sd; 2150 } 2151 2152 DECLARE_PER_CPU(struct sched_domain __rcu *, sd_llc); 2153 DECLARE_PER_CPU(int, sd_llc_size); 2154 DECLARE_PER_CPU(int, sd_llc_id); 2155 DECLARE_PER_CPU(int, sd_share_id); 2156 DECLARE_PER_CPU(struct sched_domain_shared __rcu *, sd_llc_shared); 2157 DECLARE_PER_CPU(struct sched_domain __rcu *, sd_numa); 2158 DECLARE_PER_CPU(struct sched_domain __rcu *, sd_asym_packing); 2159 DECLARE_PER_CPU(struct sched_domain __rcu *, sd_asym_cpucapacity); 2160 2161 extern struct static_key_false sched_asym_cpucapacity; 2162 extern struct static_key_false sched_cluster_active; 2163 2164 static __always_inline bool sched_asym_cpucap_active(void) 2165 { 2166 return static_branch_unlikely(&sched_asym_cpucapacity); 2167 } 2168 2169 struct sched_group_capacity { 2170 atomic_t ref; 2171 /* 2172 * CPU capacity of this group, SCHED_CAPACITY_SCALE being max capacity 2173 * for a single CPU. 2174 */ 2175 unsigned long capacity; 2176 unsigned long min_capacity; /* Min per-CPU capacity in group */ 2177 unsigned long max_capacity; /* Max per-CPU capacity in group */ 2178 unsigned long next_update; 2179 int imbalance; /* XXX unrelated to capacity but shared group state */ 2180 2181 int id; 2182 2183 unsigned long cpumask[]; /* Balance mask */ 2184 }; 2185 2186 struct sched_group { 2187 struct sched_group *next; /* Must be a circular list */ 2188 atomic_t ref; 2189 2190 unsigned int group_weight; 2191 unsigned int cores; 2192 struct sched_group_capacity *sgc; 2193 int asym_prefer_cpu; /* CPU of highest priority in group */ 2194 int flags; 2195 2196 /* 2197 * The CPUs this group covers. 2198 * 2199 * NOTE: this field is variable length. (Allocated dynamically 2200 * by attaching extra space to the end of the structure, 2201 * depending on how many CPUs the kernel has booted up with) 2202 */ 2203 unsigned long cpumask[]; 2204 }; 2205 2206 static inline struct cpumask *sched_group_span(struct sched_group *sg) 2207 { 2208 return to_cpumask(sg->cpumask); 2209 } 2210 2211 /* 2212 * See build_balance_mask(). 2213 */ 2214 static inline struct cpumask *group_balance_mask(struct sched_group *sg) 2215 { 2216 return to_cpumask(sg->sgc->cpumask); 2217 } 2218 2219 extern int group_balance_cpu(struct sched_group *sg); 2220 2221 extern void update_sched_domain_debugfs(void); 2222 extern void dirty_sched_domain_sysctl(int cpu); 2223 2224 extern int sched_update_scaling(void); 2225 2226 static inline const struct cpumask *task_user_cpus(struct task_struct *p) 2227 { 2228 if (!p->user_cpus_ptr) 2229 return cpu_possible_mask; /* &init_task.cpus_mask */ 2230 return p->user_cpus_ptr; 2231 } 2232 2233 #ifdef CONFIG_CGROUP_SCHED 2234 2235 /* 2236 * Return the group to which this tasks belongs. 2237 * 2238 * We cannot use task_css() and friends because the cgroup subsystem 2239 * changes that value before the cgroup_subsys::attach() method is called, 2240 * therefore we cannot pin it and might observe the wrong value. 2241 * 2242 * The same is true for autogroup's p->signal->autogroup->tg, the autogroup 2243 * core changes this before calling sched_move_task(). 2244 * 2245 * Instead we use a 'copy' which is updated from sched_move_task() while 2246 * holding both task_struct::pi_lock and rq::lock. 2247 */ 2248 static inline struct task_group *task_group(struct task_struct *p) 2249 { 2250 return p->sched_task_group; 2251 } 2252 2253 /* Change a task's cfs_rq and parent entity if it moves across CPUs/groups */ 2254 static inline void set_task_rq(struct task_struct *p, unsigned int cpu) 2255 { 2256 #if defined(CONFIG_FAIR_GROUP_SCHED) || defined(CONFIG_RT_GROUP_SCHED) 2257 struct task_group *tg = task_group(p); 2258 #endif 2259 2260 #ifdef CONFIG_FAIR_GROUP_SCHED 2261 set_task_rq_fair(&p->se, p->se.cfs_rq, tg->cfs_rq[cpu]); 2262 p->se.cfs_rq = tg->cfs_rq[cpu]; 2263 p->se.parent = tg->se[cpu]; 2264 p->se.depth = tg->se[cpu] ? tg->se[cpu]->depth + 1 : 0; 2265 #endif 2266 2267 #ifdef CONFIG_RT_GROUP_SCHED 2268 /* 2269 * p->rt.rt_rq is NULL initially and it is easier to assign 2270 * root_task_group's rt_rq than switching in rt_rq_of_se() 2271 * Clobbers tg(!) 2272 */ 2273 if (!rt_group_sched_enabled()) 2274 tg = &root_task_group; 2275 p->rt.rt_rq = tg->rt_rq[cpu]; 2276 p->rt.parent = tg->rt_se[cpu]; 2277 #endif /* CONFIG_RT_GROUP_SCHED */ 2278 } 2279 2280 #else /* !CONFIG_CGROUP_SCHED: */ 2281 2282 static inline void set_task_rq(struct task_struct *p, unsigned int cpu) { } 2283 2284 static inline struct task_group *task_group(struct task_struct *p) 2285 { 2286 return NULL; 2287 } 2288 2289 #endif /* !CONFIG_CGROUP_SCHED */ 2290 2291 static inline void __set_task_cpu(struct task_struct *p, unsigned int cpu) 2292 { 2293 set_task_rq(p, cpu); 2294 #ifdef CONFIG_SMP 2295 /* 2296 * After ->cpu is set up to a new value, task_rq_lock(p, ...) can be 2297 * successfully executed on another CPU. We must ensure that updates of 2298 * per-task data have been completed by this moment. 2299 */ 2300 smp_wmb(); 2301 WRITE_ONCE(task_thread_info(p)->cpu, cpu); 2302 p->wake_cpu = cpu; 2303 rseq_sched_set_ids_changed(p); 2304 #endif /* CONFIG_SMP */ 2305 } 2306 2307 /* 2308 * Tunables: 2309 */ 2310 2311 #define SCHED_FEAT(name, enabled) \ 2312 __SCHED_FEAT_##name , 2313 2314 enum { 2315 #include "features.h" 2316 __SCHED_FEAT_NR, 2317 }; 2318 2319 #undef SCHED_FEAT 2320 2321 /* 2322 * To support run-time toggling of sched features, all the translation units 2323 * (but core.c) reference the sysctl_sched_features defined in core.c. 2324 */ 2325 extern __read_mostly unsigned int sysctl_sched_features; 2326 2327 #ifdef CONFIG_JUMP_LABEL 2328 2329 #define SCHED_FEAT(name, enabled) \ 2330 static __always_inline bool static_branch_##name(struct static_key *key) \ 2331 { \ 2332 return static_key_##enabled(key); \ 2333 } 2334 2335 #include "features.h" 2336 #undef SCHED_FEAT 2337 2338 extern struct static_key sched_feat_keys[__SCHED_FEAT_NR]; 2339 #define sched_feat(x) (static_branch_##x(&sched_feat_keys[__SCHED_FEAT_##x])) 2340 2341 #else /* !CONFIG_JUMP_LABEL: */ 2342 2343 #define sched_feat(x) (sysctl_sched_features & (1UL << __SCHED_FEAT_##x)) 2344 2345 #endif /* !CONFIG_JUMP_LABEL */ 2346 2347 extern struct static_key_false sched_numa_balancing; 2348 extern struct static_key_false sched_schedstats; 2349 2350 static inline u64 global_rt_period(void) 2351 { 2352 return (u64)sysctl_sched_rt_period * NSEC_PER_USEC; 2353 } 2354 2355 static inline u64 global_rt_runtime(void) 2356 { 2357 if (sysctl_sched_rt_runtime < 0) 2358 return RUNTIME_INF; 2359 2360 return (u64)sysctl_sched_rt_runtime * NSEC_PER_USEC; 2361 } 2362 2363 /* 2364 * Is p the current execution context? 2365 */ 2366 static inline int task_current(struct rq *rq, struct task_struct *p) 2367 { 2368 return rq->curr == p; 2369 } 2370 2371 /* 2372 * Is p the current scheduling context? 2373 * 2374 * Note that it might be the current execution context at the same time if 2375 * rq->curr == rq->donor == p. 2376 */ 2377 static inline int task_current_donor(struct rq *rq, struct task_struct *p) 2378 { 2379 return rq->donor == p; 2380 } 2381 2382 static inline bool task_is_blocked(struct task_struct *p) 2383 { 2384 if (!sched_proxy_exec()) 2385 return false; 2386 2387 return !!p->blocked_on; 2388 } 2389 2390 static inline int task_on_cpu(struct rq *rq, struct task_struct *p) 2391 { 2392 return p->on_cpu; 2393 } 2394 2395 static inline int task_on_rq_queued(struct task_struct *p) 2396 { 2397 return READ_ONCE(p->on_rq) == TASK_ON_RQ_QUEUED; 2398 } 2399 2400 static inline int task_on_rq_migrating(struct task_struct *p) 2401 { 2402 return READ_ONCE(p->on_rq) == TASK_ON_RQ_MIGRATING; 2403 } 2404 2405 /* Wake flags. The first three directly map to some SD flag value */ 2406 #define WF_EXEC 0x02 /* Wakeup after exec; maps to SD_BALANCE_EXEC */ 2407 #define WF_FORK 0x04 /* Wakeup after fork; maps to SD_BALANCE_FORK */ 2408 #define WF_TTWU 0x08 /* Wakeup; maps to SD_BALANCE_WAKE */ 2409 2410 #define WF_SYNC 0x10 /* Waker goes to sleep after wakeup */ 2411 #define WF_MIGRATED 0x20 /* Internal use, task got migrated */ 2412 #define WF_CURRENT_CPU 0x40 /* Prefer to move the wakee to the current CPU. */ 2413 #define WF_RQ_SELECTED 0x80 /* ->select_task_rq() was called */ 2414 2415 static_assert(WF_EXEC == SD_BALANCE_EXEC); 2416 static_assert(WF_FORK == SD_BALANCE_FORK); 2417 static_assert(WF_TTWU == SD_BALANCE_WAKE); 2418 2419 /* 2420 * To aid in avoiding the subversion of "niceness" due to uneven distribution 2421 * of tasks with abnormal "nice" values across CPUs the contribution that 2422 * each task makes to its run queue's load is weighted according to its 2423 * scheduling class and "nice" value. For SCHED_NORMAL tasks this is just a 2424 * scaled version of the new time slice allocation that they receive on time 2425 * slice expiry etc. 2426 */ 2427 2428 #define WEIGHT_IDLEPRIO 3 2429 #define WMULT_IDLEPRIO 1431655765 2430 2431 extern const int sched_prio_to_weight[40]; 2432 extern const u32 sched_prio_to_wmult[40]; 2433 2434 /* 2435 * {de,en}queue flags: 2436 * 2437 * SLEEP/WAKEUP - task is no-longer/just-became runnable 2438 * 2439 * SAVE/RESTORE - an otherwise spurious dequeue/enqueue, done to ensure tasks 2440 * are in a known state which allows modification. Such pairs 2441 * should preserve as much state as possible. 2442 * 2443 * MOVE - paired with SAVE/RESTORE, explicitly does not preserve the location 2444 * in the runqueue. IOW the priority is allowed to change. Callers 2445 * must expect to deal with balance callbacks. 2446 * 2447 * NOCLOCK - skip the update_rq_clock() (avoids double updates) 2448 * 2449 * MIGRATION - p->on_rq == TASK_ON_RQ_MIGRATING (used for DEADLINE) 2450 * 2451 * DELAYED - de/re-queue a sched_delayed task 2452 * 2453 * CLASS - going to update p->sched_class; makes sched_change call the 2454 * various switch methods. 2455 * 2456 * ENQUEUE_HEAD - place at front of runqueue (tail if not specified) 2457 * ENQUEUE_REPLENISH - CBS (replenish runtime and postpone deadline) 2458 * ENQUEUE_MIGRATED - the task was migrated during wakeup 2459 * ENQUEUE_RQ_SELECTED - ->select_task_rq() was called 2460 * 2461 * XXX SAVE/RESTORE in combination with CLASS doesn't really make sense, but 2462 * SCHED_DEADLINE seems to rely on this for now. 2463 */ 2464 2465 #define DEQUEUE_SLEEP 0x0001 /* Matches ENQUEUE_WAKEUP */ 2466 #define DEQUEUE_SAVE 0x0002 /* Matches ENQUEUE_RESTORE */ 2467 #define DEQUEUE_MOVE 0x0004 /* Matches ENQUEUE_MOVE */ 2468 #define DEQUEUE_NOCLOCK 0x0008 /* Matches ENQUEUE_NOCLOCK */ 2469 2470 #define DEQUEUE_MIGRATING 0x0010 /* Matches ENQUEUE_MIGRATING */ 2471 #define DEQUEUE_DELAYED 0x0020 /* Matches ENQUEUE_DELAYED */ 2472 #define DEQUEUE_CLASS 0x0040 /* Matches ENQUEUE_CLASS */ 2473 2474 #define DEQUEUE_SPECIAL 0x00010000 2475 #define DEQUEUE_THROTTLE 0x00020000 2476 2477 #define ENQUEUE_WAKEUP 0x0001 2478 #define ENQUEUE_RESTORE 0x0002 2479 #define ENQUEUE_MOVE 0x0004 2480 #define ENQUEUE_NOCLOCK 0x0008 2481 2482 #define ENQUEUE_MIGRATING 0x0010 2483 #define ENQUEUE_DELAYED 0x0020 2484 #define ENQUEUE_CLASS 0x0040 2485 2486 #define ENQUEUE_HEAD 0x00010000 2487 #define ENQUEUE_REPLENISH 0x00020000 2488 #define ENQUEUE_MIGRATED 0x00040000 2489 #define ENQUEUE_INITIAL 0x00080000 2490 #define ENQUEUE_RQ_SELECTED 0x00100000 2491 2492 #define RETRY_TASK ((void *)-1UL) 2493 2494 struct affinity_context { 2495 const struct cpumask *new_mask; 2496 struct cpumask *user_mask; 2497 unsigned int flags; 2498 }; 2499 2500 extern s64 update_curr_common(struct rq *rq); 2501 2502 struct sched_class { 2503 2504 #ifdef CONFIG_UCLAMP_TASK 2505 int uclamp_enabled; 2506 #endif 2507 2508 /* 2509 * move_queued_task/activate_task/enqueue_task: rq->lock 2510 * ttwu_do_activate/activate_task/enqueue_task: rq->lock 2511 * wake_up_new_task/activate_task/enqueue_task: task_rq_lock 2512 * ttwu_runnable/enqueue_task: task_rq_lock 2513 * proxy_task_current: rq->lock 2514 * sched_change_end 2515 */ 2516 void (*enqueue_task) (struct rq *rq, struct task_struct *p, int flags); 2517 /* 2518 * move_queued_task/deactivate_task/dequeue_task: rq->lock 2519 * __schedule/block_task/dequeue_task: rq->lock 2520 * proxy_task_current: rq->lock 2521 * wait_task_inactive: task_rq_lock 2522 * sched_change_begin 2523 */ 2524 bool (*dequeue_task) (struct rq *rq, struct task_struct *p, int flags); 2525 2526 /* 2527 * do_sched_yield: rq->lock 2528 */ 2529 void (*yield_task) (struct rq *rq); 2530 /* 2531 * yield_to: rq->lock (double) 2532 */ 2533 bool (*yield_to_task)(struct rq *rq, struct task_struct *p); 2534 2535 /* 2536 * move_queued_task: rq->lock 2537 * __migrate_swap_task: rq->lock 2538 * ttwu_do_activate: rq->lock 2539 * ttwu_runnable: task_rq_lock 2540 * wake_up_new_task: task_rq_lock 2541 */ 2542 void (*wakeup_preempt)(struct rq *rq, struct task_struct *p, int flags); 2543 2544 /* 2545 * schedule/pick_next_task/prev_balance: rq->lock 2546 */ 2547 int (*balance)(struct rq *rq, struct task_struct *prev, struct rq_flags *rf); 2548 2549 /* 2550 * schedule/pick_next_task: rq->lock 2551 */ 2552 struct task_struct *(*pick_task)(struct rq *rq, struct rq_flags *rf); 2553 /* 2554 * Optional! When implemented pick_next_task() should be equivalent to: 2555 * 2556 * next = pick_task(); 2557 * if (next) { 2558 * put_prev_task(prev); 2559 * set_next_task_first(next); 2560 * } 2561 */ 2562 struct task_struct *(*pick_next_task)(struct rq *rq, struct task_struct *prev, 2563 struct rq_flags *rf); 2564 2565 /* 2566 * sched_change: 2567 * __schedule: rq->lock 2568 */ 2569 void (*put_prev_task)(struct rq *rq, struct task_struct *p, struct task_struct *next); 2570 void (*set_next_task)(struct rq *rq, struct task_struct *p, bool first); 2571 2572 /* 2573 * select_task_rq: p->pi_lock 2574 * sched_exec: p->pi_lock 2575 */ 2576 int (*select_task_rq)(struct task_struct *p, int task_cpu, int flags); 2577 2578 /* 2579 * set_task_cpu: p->pi_lock || rq->lock (ttwu like) 2580 */ 2581 void (*migrate_task_rq)(struct task_struct *p, int new_cpu); 2582 2583 /* 2584 * ttwu_do_activate: rq->lock 2585 * wake_up_new_task: task_rq_lock 2586 */ 2587 void (*task_woken)(struct rq *this_rq, struct task_struct *task); 2588 2589 /* 2590 * do_set_cpus_allowed: task_rq_lock + sched_change 2591 */ 2592 void (*set_cpus_allowed)(struct task_struct *p, struct affinity_context *ctx); 2593 2594 /* 2595 * sched_set_rq_{on,off}line: rq->lock 2596 */ 2597 void (*rq_online)(struct rq *rq); 2598 void (*rq_offline)(struct rq *rq); 2599 2600 /* 2601 * push_cpu_stop: p->pi_lock && rq->lock 2602 */ 2603 struct rq *(*find_lock_rq)(struct task_struct *p, struct rq *rq); 2604 2605 /* 2606 * hrtick: rq->lock 2607 * sched_tick: rq->lock 2608 * sched_tick_remote: rq->lock 2609 */ 2610 void (*task_tick)(struct rq *rq, struct task_struct *p, int queued); 2611 /* 2612 * sched_cgroup_fork: p->pi_lock 2613 */ 2614 void (*task_fork)(struct task_struct *p); 2615 /* 2616 * finish_task_switch: no locks 2617 */ 2618 void (*task_dead)(struct task_struct *p); 2619 2620 /* 2621 * sched_change 2622 */ 2623 void (*switching_from)(struct rq *this_rq, struct task_struct *task); 2624 void (*switched_from) (struct rq *this_rq, struct task_struct *task); 2625 void (*switching_to) (struct rq *this_rq, struct task_struct *task); 2626 void (*switched_to) (struct rq *this_rq, struct task_struct *task); 2627 u64 (*get_prio) (struct rq *this_rq, struct task_struct *task); 2628 void (*prio_changed) (struct rq *this_rq, struct task_struct *task, 2629 u64 oldprio); 2630 2631 /* 2632 * set_load_weight: task_rq_lock + sched_change 2633 * __setscheduler_parms: task_rq_lock + sched_change 2634 */ 2635 void (*reweight_task)(struct rq *this_rq, struct task_struct *task, 2636 const struct load_weight *lw); 2637 2638 /* 2639 * sched_rr_get_interval: task_rq_lock 2640 */ 2641 unsigned int (*get_rr_interval)(struct rq *rq, 2642 struct task_struct *task); 2643 2644 /* 2645 * task_sched_runtime: task_rq_lock 2646 */ 2647 void (*update_curr)(struct rq *rq); 2648 2649 #ifdef CONFIG_FAIR_GROUP_SCHED 2650 /* 2651 * sched_change_group: task_rq_lock + sched_change 2652 */ 2653 void (*task_change_group)(struct task_struct *p); 2654 #endif 2655 2656 #ifdef CONFIG_SCHED_CORE 2657 /* 2658 * pick_next_task: rq->lock 2659 * try_steal_cookie: rq->lock (double) 2660 */ 2661 int (*task_is_throttled)(struct task_struct *p, int cpu); 2662 #endif 2663 }; 2664 2665 static inline void put_prev_task(struct rq *rq, struct task_struct *prev) 2666 { 2667 WARN_ON_ONCE(rq->donor != prev); 2668 prev->sched_class->put_prev_task(rq, prev, NULL); 2669 } 2670 2671 static inline void set_next_task(struct rq *rq, struct task_struct *next) 2672 { 2673 next->sched_class->set_next_task(rq, next, false); 2674 } 2675 2676 static inline void 2677 __put_prev_set_next_dl_server(struct rq *rq, 2678 struct task_struct *prev, 2679 struct task_struct *next) 2680 { 2681 prev->dl_server = NULL; 2682 next->dl_server = rq->dl_server; 2683 rq->dl_server = NULL; 2684 } 2685 2686 static inline void put_prev_set_next_task(struct rq *rq, 2687 struct task_struct *prev, 2688 struct task_struct *next) 2689 { 2690 WARN_ON_ONCE(rq->donor != prev); 2691 2692 __put_prev_set_next_dl_server(rq, prev, next); 2693 2694 if (next == prev) 2695 return; 2696 2697 prev->sched_class->put_prev_task(rq, prev, next); 2698 next->sched_class->set_next_task(rq, next, true); 2699 } 2700 2701 /* 2702 * Helper to define a sched_class instance; each one is placed in a separate 2703 * section which is ordered by the linker script: 2704 * 2705 * include/asm-generic/vmlinux.lds.h 2706 * 2707 * *CAREFUL* they are laid out in *REVERSE* order!!! 2708 * 2709 * Also enforce alignment on the instance, not the type, to guarantee layout. 2710 */ 2711 #define DEFINE_SCHED_CLASS(name) \ 2712 const struct sched_class name##_sched_class \ 2713 __aligned(__alignof__(struct sched_class)) \ 2714 __section("__" #name "_sched_class") 2715 2716 /* Defined in include/asm-generic/vmlinux.lds.h */ 2717 extern struct sched_class __sched_class_highest[]; 2718 extern struct sched_class __sched_class_lowest[]; 2719 2720 extern const struct sched_class stop_sched_class; 2721 extern const struct sched_class dl_sched_class; 2722 extern const struct sched_class rt_sched_class; 2723 extern const struct sched_class fair_sched_class; 2724 extern const struct sched_class idle_sched_class; 2725 2726 /* 2727 * Iterate only active classes. SCX can take over all fair tasks or be 2728 * completely disabled. If the former, skip fair. If the latter, skip SCX. 2729 */ 2730 static inline const struct sched_class *next_active_class(const struct sched_class *class) 2731 { 2732 class++; 2733 #ifdef CONFIG_SCHED_CLASS_EXT 2734 if (scx_switched_all() && class == &fair_sched_class) 2735 class++; 2736 if (!scx_enabled() && class == &ext_sched_class) 2737 class++; 2738 #endif 2739 return class; 2740 } 2741 2742 #define for_class_range(class, _from, _to) \ 2743 for (class = (_from); class < (_to); class++) 2744 2745 #define for_each_class(class) \ 2746 for_class_range(class, __sched_class_highest, __sched_class_lowest) 2747 2748 #define for_active_class_range(class, _from, _to) \ 2749 for (class = (_from); class != (_to); class = next_active_class(class)) 2750 2751 #define for_each_active_class(class) \ 2752 for_active_class_range(class, __sched_class_highest, __sched_class_lowest) 2753 2754 #define sched_class_above(_a, _b) ((_a) < (_b)) 2755 2756 static inline void rq_modified_begin(struct rq *rq, const struct sched_class *class) 2757 { 2758 if (sched_class_above(rq->next_class, class)) 2759 rq->next_class = class; 2760 } 2761 2762 static inline bool rq_modified_above(struct rq *rq, const struct sched_class *class) 2763 { 2764 return sched_class_above(rq->next_class, class); 2765 } 2766 2767 static inline bool sched_stop_runnable(struct rq *rq) 2768 { 2769 return rq->stop && task_on_rq_queued(rq->stop); 2770 } 2771 2772 static inline bool sched_dl_runnable(struct rq *rq) 2773 { 2774 return rq->dl.dl_nr_running > 0; 2775 } 2776 2777 static inline bool sched_rt_runnable(struct rq *rq) 2778 { 2779 return rq->rt.rt_queued > 0; 2780 } 2781 2782 static inline bool sched_fair_runnable(struct rq *rq) 2783 { 2784 return rq->cfs.nr_queued > 0; 2785 } 2786 2787 extern struct task_struct *pick_next_task_fair(struct rq *rq, struct task_struct *prev, 2788 struct rq_flags *rf); 2789 extern struct task_struct *pick_task_idle(struct rq *rq, struct rq_flags *rf); 2790 2791 #define SCA_CHECK 0x01 2792 #define SCA_MIGRATE_DISABLE 0x02 2793 #define SCA_MIGRATE_ENABLE 0x04 2794 #define SCA_USER 0x08 2795 2796 extern void update_group_capacity(struct sched_domain *sd, int cpu); 2797 2798 extern void sched_balance_trigger(struct rq *rq); 2799 2800 extern int __set_cpus_allowed_ptr(struct task_struct *p, struct affinity_context *ctx); 2801 extern void set_cpus_allowed_common(struct task_struct *p, struct affinity_context *ctx); 2802 2803 static inline bool task_allowed_on_cpu(struct task_struct *p, int cpu) 2804 { 2805 /* When not in the task's cpumask, no point in looking further. */ 2806 if (!cpumask_test_cpu(cpu, p->cpus_ptr)) 2807 return false; 2808 2809 /* Can @cpu run a user thread? */ 2810 if (!(p->flags & PF_KTHREAD) && !task_cpu_possible(cpu, p)) 2811 return false; 2812 2813 return true; 2814 } 2815 2816 static inline cpumask_t *alloc_user_cpus_ptr(int node) 2817 { 2818 /* 2819 * See set_cpus_allowed_force() above for the rcu_head usage. 2820 */ 2821 int size = max_t(int, cpumask_size(), sizeof(struct rcu_head)); 2822 2823 return kmalloc_node(size, GFP_KERNEL, node); 2824 } 2825 2826 static inline struct task_struct *get_push_task(struct rq *rq) 2827 { 2828 struct task_struct *p = rq->donor; 2829 2830 lockdep_assert_rq_held(rq); 2831 2832 if (rq->push_busy) 2833 return NULL; 2834 2835 if (p->nr_cpus_allowed == 1) 2836 return NULL; 2837 2838 if (p->migration_disabled) 2839 return NULL; 2840 2841 rq->push_busy = true; 2842 return get_task_struct(p); 2843 } 2844 2845 extern int push_cpu_stop(void *arg); 2846 2847 #ifdef CONFIG_CPU_IDLE 2848 2849 static inline void idle_set_state(struct rq *rq, 2850 struct cpuidle_state *idle_state) 2851 { 2852 rq->idle_state = idle_state; 2853 } 2854 2855 static inline struct cpuidle_state *idle_get_state(struct rq *rq) 2856 { 2857 WARN_ON_ONCE(!rcu_read_lock_held()); 2858 2859 return rq->idle_state; 2860 } 2861 2862 #else /* !CONFIG_CPU_IDLE: */ 2863 2864 static inline void idle_set_state(struct rq *rq, 2865 struct cpuidle_state *idle_state) 2866 { 2867 } 2868 2869 static inline struct cpuidle_state *idle_get_state(struct rq *rq) 2870 { 2871 return NULL; 2872 } 2873 2874 #endif /* !CONFIG_CPU_IDLE */ 2875 2876 extern void schedule_idle(void); 2877 asmlinkage void schedule_user(void); 2878 2879 extern void sysrq_sched_debug_show(void); 2880 extern void sched_init_granularity(void); 2881 extern void update_max_interval(void); 2882 2883 extern void init_sched_dl_class(void); 2884 extern void init_sched_rt_class(void); 2885 extern void init_sched_fair_class(void); 2886 2887 extern void resched_curr(struct rq *rq); 2888 extern void resched_curr_lazy(struct rq *rq); 2889 extern void resched_cpu(int cpu); 2890 2891 extern void init_rt_bandwidth(struct rt_bandwidth *rt_b, u64 period, u64 runtime); 2892 extern bool sched_rt_bandwidth_account(struct rt_rq *rt_rq); 2893 2894 extern void init_dl_entity(struct sched_dl_entity *dl_se); 2895 2896 extern void init_cfs_throttle_work(struct task_struct *p); 2897 2898 #define BW_SHIFT 20 2899 #define BW_UNIT (1 << BW_SHIFT) 2900 #define RATIO_SHIFT 8 2901 #define MAX_BW_BITS (64 - BW_SHIFT) 2902 #define MAX_BW ((1ULL << MAX_BW_BITS) - 1) 2903 2904 extern unsigned long to_ratio(u64 period, u64 runtime); 2905 2906 extern void init_entity_runnable_average(struct sched_entity *se); 2907 extern void post_init_entity_util_avg(struct task_struct *p); 2908 2909 #ifdef CONFIG_NO_HZ_FULL 2910 extern bool sched_can_stop_tick(struct rq *rq); 2911 extern int __init sched_tick_offload_init(void); 2912 2913 /* 2914 * Tick may be needed by tasks in the runqueue depending on their policy and 2915 * requirements. If tick is needed, lets send the target an IPI to kick it out of 2916 * nohz mode if necessary. 2917 */ 2918 static inline void sched_update_tick_dependency(struct rq *rq) 2919 { 2920 int cpu = cpu_of(rq); 2921 2922 if (!tick_nohz_full_cpu(cpu)) 2923 return; 2924 2925 if (sched_can_stop_tick(rq)) 2926 tick_nohz_dep_clear_cpu(cpu, TICK_DEP_BIT_SCHED); 2927 else 2928 tick_nohz_dep_set_cpu(cpu, TICK_DEP_BIT_SCHED); 2929 } 2930 #else /* !CONFIG_NO_HZ_FULL: */ 2931 static inline int sched_tick_offload_init(void) { return 0; } 2932 static inline void sched_update_tick_dependency(struct rq *rq) { } 2933 #endif /* !CONFIG_NO_HZ_FULL */ 2934 2935 static inline void add_nr_running(struct rq *rq, unsigned count) 2936 { 2937 unsigned prev_nr = rq->nr_running; 2938 2939 rq->nr_running = prev_nr + count; 2940 if (trace_sched_update_nr_running_tp_enabled()) { 2941 call_trace_sched_update_nr_running(rq, count); 2942 } 2943 2944 if (prev_nr < 2 && rq->nr_running >= 2) 2945 set_rd_overloaded(rq->rd, 1); 2946 2947 sched_update_tick_dependency(rq); 2948 } 2949 2950 static inline void sub_nr_running(struct rq *rq, unsigned count) 2951 { 2952 rq->nr_running -= count; 2953 if (trace_sched_update_nr_running_tp_enabled()) { 2954 call_trace_sched_update_nr_running(rq, -count); 2955 } 2956 2957 /* Check if we still need preemption */ 2958 sched_update_tick_dependency(rq); 2959 } 2960 2961 static inline void __block_task(struct rq *rq, struct task_struct *p) 2962 { 2963 if (p->sched_contributes_to_load) 2964 rq->nr_uninterruptible++; 2965 2966 if (p->in_iowait) { 2967 atomic_inc(&rq->nr_iowait); 2968 delayacct_blkio_start(); 2969 } 2970 2971 ASSERT_EXCLUSIVE_WRITER(p->on_rq); 2972 2973 /* 2974 * The moment this write goes through, ttwu() can swoop in and migrate 2975 * this task, rendering our rq->__lock ineffective. 2976 * 2977 * __schedule() try_to_wake_up() 2978 * LOCK rq->__lock LOCK p->pi_lock 2979 * pick_next_task() 2980 * pick_next_task_fair() 2981 * pick_next_entity() 2982 * dequeue_entities() 2983 * __block_task() 2984 * RELEASE p->on_rq = 0 if (p->on_rq && ...) 2985 * break; 2986 * 2987 * ACQUIRE (after ctrl-dep) 2988 * 2989 * cpu = select_task_rq(); 2990 * set_task_cpu(p, cpu); 2991 * ttwu_queue() 2992 * ttwu_do_activate() 2993 * LOCK rq->__lock 2994 * activate_task() 2995 * STORE p->on_rq = 1 2996 * UNLOCK rq->__lock 2997 * 2998 * Callers must ensure to not reference @p after this -- we no longer 2999 * own it. 3000 */ 3001 smp_store_release(&p->on_rq, 0); 3002 } 3003 3004 extern void activate_task(struct rq *rq, struct task_struct *p, int flags); 3005 extern void deactivate_task(struct rq *rq, struct task_struct *p, int flags); 3006 3007 extern void wakeup_preempt(struct rq *rq, struct task_struct *p, int flags); 3008 3009 #ifdef CONFIG_PREEMPT_RT 3010 # define SCHED_NR_MIGRATE_BREAK 8 3011 #else 3012 # define SCHED_NR_MIGRATE_BREAK 32 3013 #endif 3014 3015 extern __read_mostly unsigned int sysctl_sched_nr_migrate; 3016 extern __read_mostly unsigned int sysctl_sched_migration_cost; 3017 3018 extern unsigned int sysctl_sched_base_slice; 3019 3020 extern int sysctl_resched_latency_warn_ms; 3021 extern int sysctl_resched_latency_warn_once; 3022 3023 extern unsigned int sysctl_sched_tunable_scaling; 3024 3025 extern unsigned int sysctl_numa_balancing_scan_delay; 3026 extern unsigned int sysctl_numa_balancing_scan_period_min; 3027 extern unsigned int sysctl_numa_balancing_scan_period_max; 3028 extern unsigned int sysctl_numa_balancing_scan_size; 3029 extern unsigned int sysctl_numa_balancing_hot_threshold; 3030 3031 #ifdef CONFIG_SCHED_HRTICK 3032 3033 /* 3034 * Use hrtick when: 3035 * - enabled by features 3036 * - hrtimer is actually high res 3037 */ 3038 static inline bool hrtick_enabled(struct rq *rq) 3039 { 3040 return cpu_active(cpu_of(rq)) && hrtimer_highres_enabled(); 3041 } 3042 3043 static inline bool hrtick_enabled_fair(struct rq *rq) 3044 { 3045 return sched_feat(HRTICK) && hrtick_enabled(rq); 3046 } 3047 3048 static inline bool hrtick_enabled_dl(struct rq *rq) 3049 { 3050 return sched_feat(HRTICK_DL) && hrtick_enabled(rq); 3051 } 3052 3053 extern void hrtick_start(struct rq *rq, u64 delay); 3054 static inline bool hrtick_active(struct rq *rq) 3055 { 3056 return hrtimer_active(&rq->hrtick_timer); 3057 } 3058 3059 #else /* !CONFIG_SCHED_HRTICK: */ 3060 static inline bool hrtick_enabled_fair(struct rq *rq) { return false; } 3061 static inline bool hrtick_enabled_dl(struct rq *rq) { return false; } 3062 static inline bool hrtick_enabled(struct rq *rq) { return false; } 3063 #endif /* !CONFIG_SCHED_HRTICK */ 3064 3065 #ifndef arch_scale_freq_tick 3066 static __always_inline void arch_scale_freq_tick(void) { } 3067 #endif 3068 3069 #ifndef arch_scale_freq_capacity 3070 /** 3071 * arch_scale_freq_capacity - get the frequency scale factor of a given CPU. 3072 * @cpu: the CPU in question. 3073 * 3074 * Return: the frequency scale factor normalized against SCHED_CAPACITY_SCALE, i.e. 3075 * 3076 * f_curr 3077 * ------ * SCHED_CAPACITY_SCALE 3078 * f_max 3079 */ 3080 static __always_inline 3081 unsigned long arch_scale_freq_capacity(int cpu) 3082 { 3083 return SCHED_CAPACITY_SCALE; 3084 } 3085 #endif 3086 3087 /* 3088 * In double_lock_balance()/double_rq_lock(), we use raw_spin_rq_lock() to 3089 * acquire rq lock instead of rq_lock(). So at the end of these two functions 3090 * we need to call double_rq_clock_clear_update() to clear RQCF_UPDATED of 3091 * rq->clock_update_flags to avoid the WARN_DOUBLE_CLOCK warning. 3092 */ 3093 static inline void double_rq_clock_clear_update(struct rq *rq1, struct rq *rq2) 3094 { 3095 rq1->clock_update_flags &= (RQCF_REQ_SKIP|RQCF_ACT_SKIP); 3096 rq2->clock_update_flags &= (RQCF_REQ_SKIP|RQCF_ACT_SKIP); 3097 } 3098 3099 #define DEFINE_LOCK_GUARD_2(name, type, _lock, _unlock, ...) \ 3100 __DEFINE_UNLOCK_GUARD(name, type, _unlock, type *lock2; __VA_ARGS__) \ 3101 static inline class_##name##_t class_##name##_constructor(type *lock, type *lock2) \ 3102 __no_context_analysis \ 3103 { class_##name##_t _t = { .lock = lock, .lock2 = lock2 }, *_T = &_t; \ 3104 _lock; return _t; } 3105 #define DECLARE_LOCK_GUARD_2_ATTRS(_name, _lock, _unlock1, _unlock2) \ 3106 static inline class_##_name##_t class_##_name##_constructor(lock_##_name##_t *_T1, \ 3107 lock_##_name##_t *_T2) _lock; \ 3108 static __always_inline void __class_##_name##_cleanup_ctx1(class_##_name##_t **_T1) \ 3109 __no_context_analysis _unlock1 { } \ 3110 static __always_inline void __class_##_name##_cleanup_ctx2(class_##_name##_t **_T2) \ 3111 __no_context_analysis _unlock2 { } 3112 #define WITH_LOCK_GUARD_2_ATTRS(_name, _T1, _T2) \ 3113 class_##_name##_constructor(_T1, _T2), \ 3114 *__UNIQUE_ID(unlock1) __cleanup(__class_##_name##_cleanup_ctx1) = (void *)(_T1),\ 3115 *__UNIQUE_ID(unlock2) __cleanup(__class_##_name##_cleanup_ctx2) = (void *)(_T2) 3116 3117 static inline bool rq_order_less(struct rq *rq1, struct rq *rq2) 3118 { 3119 #ifdef CONFIG_SCHED_CORE 3120 /* 3121 * In order to not have {0,2},{1,3} turn into into an AB-BA, 3122 * order by core-id first and cpu-id second. 3123 * 3124 * Notably: 3125 * 3126 * double_rq_lock(0,3); will take core-0, core-1 lock 3127 * double_rq_lock(1,2); will take core-1, core-0 lock 3128 * 3129 * when only cpu-id is considered. 3130 */ 3131 if (rq1->core->cpu < rq2->core->cpu) 3132 return true; 3133 if (rq1->core->cpu > rq2->core->cpu) 3134 return false; 3135 3136 /* 3137 * __sched_core_flip() relies on SMT having cpu-id lock order. 3138 */ 3139 #endif /* CONFIG_SCHED_CORE */ 3140 return rq1->cpu < rq2->cpu; 3141 } 3142 3143 extern void double_rq_lock(struct rq *rq1, struct rq *rq2) 3144 __acquires(__rq_lockp(rq1), __rq_lockp(rq2)); 3145 3146 #ifdef CONFIG_PREEMPTION 3147 3148 /* 3149 * fair double_lock_balance: Safely acquires both rq->locks in a fair 3150 * way at the expense of forcing extra atomic operations in all 3151 * invocations. This assures that the double_lock is acquired using the 3152 * same underlying policy as the spinlock_t on this architecture, which 3153 * reduces latency compared to the unfair variant below. However, it 3154 * also adds more overhead and therefore may reduce throughput. 3155 */ 3156 static inline int _double_lock_balance(struct rq *this_rq, struct rq *busiest) 3157 __must_hold(__rq_lockp(this_rq)) 3158 __acquires(__rq_lockp(busiest)) 3159 { 3160 raw_spin_rq_unlock(this_rq); 3161 double_rq_lock(this_rq, busiest); 3162 3163 return 1; 3164 } 3165 3166 #else /* !CONFIG_PREEMPTION: */ 3167 /* 3168 * Unfair double_lock_balance: Optimizes throughput at the expense of 3169 * latency by eliminating extra atomic operations when the locks are 3170 * already in proper order on entry. This favors lower CPU-ids and will 3171 * grant the double lock to lower CPUs over higher ids under contention, 3172 * regardless of entry order into the function. 3173 */ 3174 static inline int _double_lock_balance(struct rq *this_rq, struct rq *busiest) 3175 __must_hold(__rq_lockp(this_rq)) 3176 __acquires(__rq_lockp(busiest)) 3177 { 3178 if (__rq_lockp(this_rq) == __rq_lockp(busiest)) { 3179 __acquire(__rq_lockp(busiest)); /* already held */ 3180 double_rq_clock_clear_update(this_rq, busiest); 3181 return 0; 3182 } 3183 3184 if (likely(raw_spin_rq_trylock(busiest))) { 3185 double_rq_clock_clear_update(this_rq, busiest); 3186 return 0; 3187 } 3188 3189 if (rq_order_less(this_rq, busiest)) { 3190 raw_spin_rq_lock_nested(busiest, SINGLE_DEPTH_NESTING); 3191 double_rq_clock_clear_update(this_rq, busiest); 3192 return 0; 3193 } 3194 3195 raw_spin_rq_unlock(this_rq); 3196 double_rq_lock(this_rq, busiest); 3197 3198 return 1; 3199 } 3200 3201 #endif /* !CONFIG_PREEMPTION */ 3202 3203 /* 3204 * double_lock_balance - lock the busiest runqueue, this_rq is locked already. 3205 */ 3206 static inline int double_lock_balance(struct rq *this_rq, struct rq *busiest) 3207 __must_hold(__rq_lockp(this_rq)) 3208 __acquires(__rq_lockp(busiest)) 3209 { 3210 lockdep_assert_irqs_disabled(); 3211 3212 return _double_lock_balance(this_rq, busiest); 3213 } 3214 3215 static inline void double_unlock_balance(struct rq *this_rq, struct rq *busiest) 3216 __releases(__rq_lockp(busiest)) 3217 { 3218 if (__rq_lockp(this_rq) != __rq_lockp(busiest)) 3219 raw_spin_rq_unlock(busiest); 3220 else 3221 __release(__rq_lockp(busiest)); /* fake release */ 3222 lock_set_subclass(&__rq_lockp(this_rq)->dep_map, 0, _RET_IP_); 3223 } 3224 3225 static inline void double_lock(spinlock_t *l1, spinlock_t *l2) 3226 __acquires(l1, l2) 3227 { 3228 if (l1 > l2) 3229 swap(l1, l2); 3230 3231 spin_lock(l1); 3232 spin_lock_nested(l2, SINGLE_DEPTH_NESTING); 3233 } 3234 3235 static inline void double_lock_irq(spinlock_t *l1, spinlock_t *l2) 3236 __acquires(l1, l2) 3237 { 3238 if (l1 > l2) 3239 swap(l1, l2); 3240 3241 spin_lock_irq(l1); 3242 spin_lock_nested(l2, SINGLE_DEPTH_NESTING); 3243 } 3244 3245 static inline void double_raw_lock(raw_spinlock_t *l1, raw_spinlock_t *l2) 3246 __acquires(l1, l2) 3247 { 3248 if (l1 > l2) 3249 swap(l1, l2); 3250 3251 raw_spin_lock(l1); 3252 raw_spin_lock_nested(l2, SINGLE_DEPTH_NESTING); 3253 } 3254 3255 static inline void double_raw_unlock(raw_spinlock_t *l1, raw_spinlock_t *l2) 3256 __releases(l1, l2) 3257 { 3258 raw_spin_unlock(l1); 3259 raw_spin_unlock(l2); 3260 } 3261 3262 DEFINE_LOCK_GUARD_2(double_raw_spinlock, raw_spinlock_t, 3263 double_raw_lock(_T->lock, _T->lock2), 3264 double_raw_unlock(_T->lock, _T->lock2)) 3265 3266 DECLARE_LOCK_GUARD_2_ATTRS(double_raw_spinlock, 3267 __acquires(_T1, _T2), 3268 __releases(*(raw_spinlock_t **)_T1), 3269 __releases(*(raw_spinlock_t **)_T2)); 3270 #define class_double_raw_spinlock_constructor(_T1, _T2) \ 3271 WITH_LOCK_GUARD_2_ATTRS(double_raw_spinlock, _T1, _T2) 3272 3273 /* 3274 * double_rq_unlock - safely unlock two runqueues 3275 * 3276 * Note this does not restore interrupts like task_rq_unlock, 3277 * you need to do so manually after calling. 3278 */ 3279 static inline void double_rq_unlock(struct rq *rq1, struct rq *rq2) 3280 __releases(__rq_lockp(rq1), __rq_lockp(rq2)) 3281 { 3282 if (__rq_lockp(rq1) != __rq_lockp(rq2)) 3283 raw_spin_rq_unlock(rq2); 3284 else 3285 __release(__rq_lockp(rq2)); /* fake release */ 3286 raw_spin_rq_unlock(rq1); 3287 } 3288 3289 extern void set_rq_online (struct rq *rq); 3290 extern void set_rq_offline(struct rq *rq); 3291 3292 extern bool sched_smp_initialized; 3293 3294 DEFINE_LOCK_GUARD_2(double_rq_lock, struct rq, 3295 double_rq_lock(_T->lock, _T->lock2), 3296 double_rq_unlock(_T->lock, _T->lock2)) 3297 3298 extern struct sched_entity *__pick_root_entity(struct cfs_rq *cfs_rq); 3299 extern struct sched_entity *__pick_first_entity(struct cfs_rq *cfs_rq); 3300 extern struct sched_entity *__pick_last_entity(struct cfs_rq *cfs_rq); 3301 3302 extern bool sched_debug_verbose; 3303 3304 extern void print_cfs_stats(struct seq_file *m, int cpu); 3305 extern void print_rt_stats(struct seq_file *m, int cpu); 3306 extern void print_dl_stats(struct seq_file *m, int cpu); 3307 extern void print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq); 3308 extern void print_rt_rq(struct seq_file *m, int cpu, struct rt_rq *rt_rq); 3309 extern void print_dl_rq(struct seq_file *m, int cpu, struct dl_rq *dl_rq); 3310 3311 extern void resched_latency_warn(int cpu, u64 latency); 3312 3313 #ifdef CONFIG_NUMA_BALANCING 3314 extern void show_numa_stats(struct task_struct *p, struct seq_file *m); 3315 extern void 3316 print_numa_stats(struct seq_file *m, int node, unsigned long tsf, 3317 unsigned long tpf, unsigned long gsf, unsigned long gpf); 3318 #endif /* CONFIG_NUMA_BALANCING */ 3319 3320 extern void init_cfs_rq(struct cfs_rq *cfs_rq); 3321 extern void init_rt_rq(struct rt_rq *rt_rq); 3322 extern void init_dl_rq(struct dl_rq *dl_rq); 3323 3324 extern void cfs_bandwidth_usage_inc(void); 3325 extern void cfs_bandwidth_usage_dec(void); 3326 3327 #ifdef CONFIG_NO_HZ_COMMON 3328 3329 #define NOHZ_BALANCE_KICK_BIT 0 3330 #define NOHZ_STATS_KICK_BIT 1 3331 #define NOHZ_NEWILB_KICK_BIT 2 3332 #define NOHZ_NEXT_KICK_BIT 3 3333 3334 /* Run sched_balance_domains() */ 3335 #define NOHZ_BALANCE_KICK BIT(NOHZ_BALANCE_KICK_BIT) 3336 /* Update blocked load */ 3337 #define NOHZ_STATS_KICK BIT(NOHZ_STATS_KICK_BIT) 3338 /* Update blocked load when entering idle */ 3339 #define NOHZ_NEWILB_KICK BIT(NOHZ_NEWILB_KICK_BIT) 3340 /* Update nohz.next_balance */ 3341 #define NOHZ_NEXT_KICK BIT(NOHZ_NEXT_KICK_BIT) 3342 3343 #define NOHZ_KICK_MASK (NOHZ_BALANCE_KICK | NOHZ_STATS_KICK | NOHZ_NEXT_KICK) 3344 3345 #define nohz_flags(cpu) (&cpu_rq(cpu)->nohz_flags) 3346 3347 extern void nohz_balance_exit_idle(struct rq *rq); 3348 #else /* !CONFIG_NO_HZ_COMMON: */ 3349 static inline void nohz_balance_exit_idle(struct rq *rq) { } 3350 #endif /* !CONFIG_NO_HZ_COMMON */ 3351 3352 #ifdef CONFIG_NO_HZ_COMMON 3353 extern void nohz_run_idle_balance(int cpu); 3354 #else 3355 static inline void nohz_run_idle_balance(int cpu) { } 3356 #endif 3357 3358 #include "stats.h" 3359 3360 #if defined(CONFIG_SCHED_CORE) && defined(CONFIG_SCHEDSTATS) 3361 3362 extern void __sched_core_account_forceidle(struct rq *rq); 3363 3364 static inline void sched_core_account_forceidle(struct rq *rq) 3365 { 3366 if (schedstat_enabled()) 3367 __sched_core_account_forceidle(rq); 3368 } 3369 3370 extern void __sched_core_tick(struct rq *rq); 3371 3372 static inline void sched_core_tick(struct rq *rq) 3373 { 3374 if (sched_core_enabled(rq) && schedstat_enabled()) 3375 __sched_core_tick(rq); 3376 } 3377 3378 #else /* !(CONFIG_SCHED_CORE && CONFIG_SCHEDSTATS): */ 3379 3380 static inline void sched_core_account_forceidle(struct rq *rq) { } 3381 3382 static inline void sched_core_tick(struct rq *rq) { } 3383 3384 #endif /* !(CONFIG_SCHED_CORE && CONFIG_SCHEDSTATS) */ 3385 3386 #ifdef CONFIG_IRQ_TIME_ACCOUNTING 3387 3388 struct irqtime { 3389 u64 total; 3390 u64 tick_delta; 3391 u64 irq_start_time; 3392 struct u64_stats_sync sync; 3393 }; 3394 3395 DECLARE_PER_CPU(struct irqtime, cpu_irqtime); 3396 DECLARE_STATIC_KEY_FALSE(sched_clock_irqtime); 3397 3398 static inline int irqtime_enabled(void) 3399 { 3400 return static_branch_likely(&sched_clock_irqtime); 3401 } 3402 3403 /* 3404 * Returns the irqtime minus the softirq time computed by ksoftirqd. 3405 * Otherwise ksoftirqd's sum_exec_runtime is subtracted its own runtime 3406 * and never move forward. 3407 */ 3408 static inline u64 irq_time_read(int cpu) 3409 { 3410 struct irqtime *irqtime = &per_cpu(cpu_irqtime, cpu); 3411 unsigned int seq; 3412 u64 total; 3413 3414 do { 3415 seq = __u64_stats_fetch_begin(&irqtime->sync); 3416 total = irqtime->total; 3417 } while (__u64_stats_fetch_retry(&irqtime->sync, seq)); 3418 3419 return total; 3420 } 3421 3422 #else /* !CONFIG_IRQ_TIME_ACCOUNTING: */ 3423 3424 static inline int irqtime_enabled(void) 3425 { 3426 return 0; 3427 } 3428 3429 #endif /* !CONFIG_IRQ_TIME_ACCOUNTING */ 3430 3431 #ifdef CONFIG_CPU_FREQ 3432 3433 DECLARE_PER_CPU(struct update_util_data __rcu *, cpufreq_update_util_data); 3434 3435 /** 3436 * cpufreq_update_util - Take a note about CPU utilization changes. 3437 * @rq: Runqueue to carry out the update for. 3438 * @flags: Update reason flags. 3439 * 3440 * This function is called by the scheduler on the CPU whose utilization is 3441 * being updated. 3442 * 3443 * It can only be called from RCU-sched read-side critical sections. 3444 * 3445 * The way cpufreq is currently arranged requires it to evaluate the CPU 3446 * performance state (frequency/voltage) on a regular basis to prevent it from 3447 * being stuck in a completely inadequate performance level for too long. 3448 * That is not guaranteed to happen if the updates are only triggered from CFS 3449 * and DL, though, because they may not be coming in if only RT tasks are 3450 * active all the time (or there are RT tasks only). 3451 * 3452 * As a workaround for that issue, this function is called periodically by the 3453 * RT sched class to trigger extra cpufreq updates to prevent it from stalling, 3454 * but that really is a band-aid. Going forward it should be replaced with 3455 * solutions targeted more specifically at RT tasks. 3456 */ 3457 static inline void cpufreq_update_util(struct rq *rq, unsigned int flags) 3458 { 3459 struct update_util_data *data; 3460 3461 data = rcu_dereference_sched(*per_cpu_ptr(&cpufreq_update_util_data, 3462 cpu_of(rq))); 3463 if (data) 3464 data->func(data, rq_clock(rq), flags); 3465 } 3466 #else /* !CONFIG_CPU_FREQ: */ 3467 static inline void cpufreq_update_util(struct rq *rq, unsigned int flags) { } 3468 #endif /* !CONFIG_CPU_FREQ */ 3469 3470 #ifdef arch_scale_freq_capacity 3471 # ifndef arch_scale_freq_invariant 3472 # define arch_scale_freq_invariant() true 3473 # endif 3474 #else 3475 # define arch_scale_freq_invariant() false 3476 #endif 3477 3478 unsigned long effective_cpu_util(int cpu, unsigned long util_cfs, 3479 unsigned long *min, 3480 unsigned long *max); 3481 3482 unsigned long sugov_effective_cpu_perf(int cpu, unsigned long actual, 3483 unsigned long min, 3484 unsigned long max); 3485 3486 3487 /* 3488 * Verify the fitness of task @p to run on @cpu taking into account the 3489 * CPU original capacity and the runtime/deadline ratio of the task. 3490 * 3491 * The function will return true if the original capacity of @cpu is 3492 * greater than or equal to task's deadline density right shifted by 3493 * (BW_SHIFT - SCHED_CAPACITY_SHIFT) and false otherwise. 3494 */ 3495 static inline bool dl_task_fits_capacity(struct task_struct *p, int cpu) 3496 { 3497 unsigned long cap = arch_scale_cpu_capacity(cpu); 3498 3499 return cap >= p->dl.dl_density >> (BW_SHIFT - SCHED_CAPACITY_SHIFT); 3500 } 3501 3502 static inline unsigned long cpu_bw_dl(struct rq *rq) 3503 { 3504 return (rq->dl.running_bw * SCHED_CAPACITY_SCALE) >> BW_SHIFT; 3505 } 3506 3507 static inline unsigned long cpu_util_dl(struct rq *rq) 3508 { 3509 return READ_ONCE(rq->avg_dl.util_avg); 3510 } 3511 3512 3513 extern unsigned long cpu_util_cfs(int cpu); 3514 extern unsigned long cpu_util_cfs_boost(int cpu); 3515 3516 static inline unsigned long cpu_util_rt(struct rq *rq) 3517 { 3518 return READ_ONCE(rq->avg_rt.util_avg); 3519 } 3520 3521 #ifdef CONFIG_UCLAMP_TASK 3522 3523 unsigned long uclamp_eff_value(struct task_struct *p, enum uclamp_id clamp_id); 3524 3525 /* 3526 * When uclamp is compiled in, the aggregation at rq level is 'turned off' 3527 * by default in the fast path and only gets turned on once userspace performs 3528 * an operation that requires it. 3529 * 3530 * Returns true if userspace opted-in to use uclamp and aggregation at rq level 3531 * hence is active. 3532 */ 3533 static inline bool uclamp_is_used(void) 3534 { 3535 return static_branch_likely(&sched_uclamp_used); 3536 } 3537 3538 /* 3539 * Enabling static branches would get the cpus_read_lock(), 3540 * check whether uclamp_is_used before enable it to avoid always 3541 * calling cpus_read_lock(). Because we never disable this 3542 * static key once enable it. 3543 */ 3544 static inline void sched_uclamp_enable(void) 3545 { 3546 if (!uclamp_is_used()) 3547 static_branch_enable(&sched_uclamp_used); 3548 } 3549 3550 static inline unsigned long uclamp_rq_get(struct rq *rq, 3551 enum uclamp_id clamp_id) 3552 { 3553 return READ_ONCE(rq->uclamp[clamp_id].value); 3554 } 3555 3556 static inline void uclamp_rq_set(struct rq *rq, enum uclamp_id clamp_id, 3557 unsigned int value) 3558 { 3559 WRITE_ONCE(rq->uclamp[clamp_id].value, value); 3560 } 3561 3562 static inline bool uclamp_rq_is_idle(struct rq *rq) 3563 { 3564 return rq->uclamp_flags & UCLAMP_FLAG_IDLE; 3565 } 3566 3567 /* Is the rq being capped/throttled by uclamp_max? */ 3568 static inline bool uclamp_rq_is_capped(struct rq *rq) 3569 { 3570 unsigned long rq_util; 3571 unsigned long max_util; 3572 3573 if (!uclamp_is_used()) 3574 return false; 3575 3576 rq_util = cpu_util_cfs(cpu_of(rq)) + cpu_util_rt(rq); 3577 max_util = READ_ONCE(rq->uclamp[UCLAMP_MAX].value); 3578 3579 return max_util != SCHED_CAPACITY_SCALE && rq_util >= max_util; 3580 } 3581 3582 #define for_each_clamp_id(clamp_id) \ 3583 for ((clamp_id) = 0; (clamp_id) < UCLAMP_CNT; (clamp_id)++) 3584 3585 extern unsigned int sysctl_sched_uclamp_util_min_rt_default; 3586 3587 3588 static inline unsigned int uclamp_none(enum uclamp_id clamp_id) 3589 { 3590 if (clamp_id == UCLAMP_MIN) 3591 return 0; 3592 return SCHED_CAPACITY_SCALE; 3593 } 3594 3595 /* Integer rounded range for each bucket */ 3596 #define UCLAMP_BUCKET_DELTA DIV_ROUND_CLOSEST(SCHED_CAPACITY_SCALE, UCLAMP_BUCKETS) 3597 3598 static inline unsigned int uclamp_bucket_id(unsigned int clamp_value) 3599 { 3600 return min_t(unsigned int, clamp_value / UCLAMP_BUCKET_DELTA, UCLAMP_BUCKETS - 1); 3601 } 3602 3603 static inline void 3604 uclamp_se_set(struct uclamp_se *uc_se, unsigned int value, bool user_defined) 3605 { 3606 uc_se->value = value; 3607 uc_se->bucket_id = uclamp_bucket_id(value); 3608 uc_se->user_defined = user_defined; 3609 } 3610 3611 #else /* !CONFIG_UCLAMP_TASK: */ 3612 3613 static inline unsigned long 3614 uclamp_eff_value(struct task_struct *p, enum uclamp_id clamp_id) 3615 { 3616 if (clamp_id == UCLAMP_MIN) 3617 return 0; 3618 3619 return SCHED_CAPACITY_SCALE; 3620 } 3621 3622 static inline bool uclamp_rq_is_capped(struct rq *rq) { return false; } 3623 3624 static inline bool uclamp_is_used(void) 3625 { 3626 return false; 3627 } 3628 3629 static inline void sched_uclamp_enable(void) {} 3630 3631 static inline unsigned long 3632 uclamp_rq_get(struct rq *rq, enum uclamp_id clamp_id) 3633 { 3634 if (clamp_id == UCLAMP_MIN) 3635 return 0; 3636 3637 return SCHED_CAPACITY_SCALE; 3638 } 3639 3640 static inline void 3641 uclamp_rq_set(struct rq *rq, enum uclamp_id clamp_id, unsigned int value) 3642 { 3643 } 3644 3645 static inline bool uclamp_rq_is_idle(struct rq *rq) 3646 { 3647 return false; 3648 } 3649 3650 #endif /* !CONFIG_UCLAMP_TASK */ 3651 3652 #ifdef CONFIG_HAVE_SCHED_AVG_IRQ 3653 3654 static inline unsigned long cpu_util_irq(struct rq *rq) 3655 { 3656 return READ_ONCE(rq->avg_irq.util_avg); 3657 } 3658 3659 static inline 3660 unsigned long scale_irq_capacity(unsigned long util, unsigned long irq, unsigned long max) 3661 { 3662 util *= (max - irq); 3663 util /= max; 3664 3665 return util; 3666 3667 } 3668 3669 #else /* !CONFIG_HAVE_SCHED_AVG_IRQ: */ 3670 3671 static inline unsigned long cpu_util_irq(struct rq *rq) 3672 { 3673 return 0; 3674 } 3675 3676 static inline 3677 unsigned long scale_irq_capacity(unsigned long util, unsigned long irq, unsigned long max) 3678 { 3679 return util; 3680 } 3681 3682 #endif /* !CONFIG_HAVE_SCHED_AVG_IRQ */ 3683 3684 extern void __setparam_fair(struct task_struct *p, const struct sched_attr *attr); 3685 3686 #if defined(CONFIG_ENERGY_MODEL) && defined(CONFIG_CPU_FREQ_GOV_SCHEDUTIL) 3687 3688 #define perf_domain_span(pd) (to_cpumask(((pd)->em_pd->cpus))) 3689 3690 DECLARE_STATIC_KEY_FALSE(sched_energy_present); 3691 3692 static inline bool sched_energy_enabled(void) 3693 { 3694 return static_branch_unlikely(&sched_energy_present); 3695 } 3696 3697 #else /* !(CONFIG_ENERGY_MODEL && CONFIG_CPU_FREQ_GOV_SCHEDUTIL): */ 3698 3699 #define perf_domain_span(pd) NULL 3700 3701 static inline bool sched_energy_enabled(void) { return false; } 3702 3703 #endif /* !(CONFIG_ENERGY_MODEL && CONFIG_CPU_FREQ_GOV_SCHEDUTIL) */ 3704 3705 #ifdef CONFIG_MEMBARRIER 3706 3707 /* 3708 * The scheduler provides memory barriers required by membarrier between: 3709 * - prior user-space memory accesses and store to rq->membarrier_state, 3710 * - store to rq->membarrier_state and following user-space memory accesses. 3711 * In the same way it provides those guarantees around store to rq->curr. 3712 */ 3713 static inline void membarrier_switch_mm(struct rq *rq, 3714 struct mm_struct *prev_mm, 3715 struct mm_struct *next_mm) 3716 { 3717 int membarrier_state; 3718 3719 if (prev_mm == next_mm) 3720 return; 3721 3722 membarrier_state = atomic_read(&next_mm->membarrier_state); 3723 if (READ_ONCE(rq->membarrier_state) == membarrier_state) 3724 return; 3725 3726 WRITE_ONCE(rq->membarrier_state, membarrier_state); 3727 } 3728 3729 #else /* !CONFIG_MEMBARRIER: */ 3730 3731 static inline void membarrier_switch_mm(struct rq *rq, 3732 struct mm_struct *prev_mm, 3733 struct mm_struct *next_mm) 3734 { 3735 } 3736 3737 #endif /* !CONFIG_MEMBARRIER */ 3738 3739 static inline bool is_per_cpu_kthread(struct task_struct *p) 3740 { 3741 if (!(p->flags & PF_KTHREAD)) 3742 return false; 3743 3744 if (p->nr_cpus_allowed != 1) 3745 return false; 3746 3747 return true; 3748 } 3749 3750 extern void swake_up_all_locked(struct swait_queue_head *q); 3751 extern void __prepare_to_swait(struct swait_queue_head *q, struct swait_queue *wait); 3752 3753 extern int try_to_wake_up(struct task_struct *tsk, unsigned int state, int wake_flags); 3754 3755 #ifdef CONFIG_PREEMPT_DYNAMIC 3756 extern int preempt_dynamic_mode; 3757 extern int sched_dynamic_mode(const char *str); 3758 extern void sched_dynamic_update(int mode); 3759 #endif 3760 extern const char *preempt_modes[]; 3761 3762 #ifdef CONFIG_SCHED_MM_CID 3763 3764 static __always_inline bool cid_on_cpu(unsigned int cid) 3765 { 3766 return cid & MM_CID_ONCPU; 3767 } 3768 3769 static __always_inline bool cid_in_transit(unsigned int cid) 3770 { 3771 return cid & MM_CID_TRANSIT; 3772 } 3773 3774 static __always_inline unsigned int cpu_cid_to_cid(unsigned int cid) 3775 { 3776 return cid & ~MM_CID_ONCPU; 3777 } 3778 3779 static __always_inline unsigned int cid_to_cpu_cid(unsigned int cid) 3780 { 3781 return cid | MM_CID_ONCPU; 3782 } 3783 3784 static __always_inline unsigned int cid_to_transit_cid(unsigned int cid) 3785 { 3786 return cid | MM_CID_TRANSIT; 3787 } 3788 3789 static __always_inline unsigned int cid_from_transit_cid(unsigned int cid) 3790 { 3791 return cid & ~MM_CID_TRANSIT; 3792 } 3793 3794 static __always_inline bool cid_on_task(unsigned int cid) 3795 { 3796 /* True if none of the MM_CID_ONCPU, MM_CID_TRANSIT, MM_CID_UNSET bits is set */ 3797 return cid < MM_CID_TRANSIT; 3798 } 3799 3800 static __always_inline void mm_drop_cid(struct mm_struct *mm, unsigned int cid) 3801 { 3802 clear_bit(cid, mm_cidmask(mm)); 3803 } 3804 3805 static __always_inline void mm_unset_cid_on_task(struct task_struct *t) 3806 { 3807 unsigned int cid = t->mm_cid.cid; 3808 3809 t->mm_cid.cid = MM_CID_UNSET; 3810 if (cid_on_task(cid)) 3811 mm_drop_cid(t->mm, cid); 3812 } 3813 3814 static __always_inline void mm_drop_cid_on_cpu(struct mm_struct *mm, struct mm_cid_pcpu *pcp) 3815 { 3816 /* Clear the ONCPU bit, but do not set UNSET in the per CPU storage */ 3817 if (cid_on_cpu(pcp->cid)) { 3818 pcp->cid = cpu_cid_to_cid(pcp->cid); 3819 mm_drop_cid(mm, pcp->cid); 3820 } 3821 } 3822 3823 static inline unsigned int __mm_get_cid(struct mm_struct *mm, unsigned int max_cids) 3824 { 3825 unsigned int cid = find_first_zero_bit(mm_cidmask(mm), max_cids); 3826 3827 if (cid >= max_cids) 3828 return MM_CID_UNSET; 3829 if (test_and_set_bit(cid, mm_cidmask(mm))) 3830 return MM_CID_UNSET; 3831 return cid; 3832 } 3833 3834 static inline unsigned int mm_get_cid(struct mm_struct *mm) 3835 { 3836 unsigned int cid = __mm_get_cid(mm, READ_ONCE(mm->mm_cid.max_cids)); 3837 3838 while (cid == MM_CID_UNSET) { 3839 cpu_relax(); 3840 cid = __mm_get_cid(mm, num_possible_cpus()); 3841 } 3842 return cid; 3843 } 3844 3845 static inline unsigned int mm_cid_converge(struct mm_struct *mm, unsigned int orig_cid, 3846 unsigned int max_cids) 3847 { 3848 unsigned int new_cid, cid = cpu_cid_to_cid(orig_cid); 3849 3850 /* Is it in the optimal CID space? */ 3851 if (likely(cid < max_cids)) 3852 return orig_cid; 3853 3854 /* Try to find one in the optimal space. Otherwise keep the provided. */ 3855 new_cid = __mm_get_cid(mm, max_cids); 3856 if (new_cid != MM_CID_UNSET) { 3857 mm_drop_cid(mm, cid); 3858 /* Preserve the ONCPU mode of the original CID */ 3859 return new_cid | (orig_cid & MM_CID_ONCPU); 3860 } 3861 return orig_cid; 3862 } 3863 3864 static __always_inline void mm_cid_update_task_cid(struct task_struct *t, unsigned int cid) 3865 { 3866 if (t->mm_cid.cid != cid) { 3867 t->mm_cid.cid = cid; 3868 rseq_sched_set_ids_changed(t); 3869 } 3870 } 3871 3872 static __always_inline void mm_cid_update_pcpu_cid(struct mm_struct *mm, unsigned int cid) 3873 { 3874 __this_cpu_write(mm->mm_cid.pcpu->cid, cid); 3875 } 3876 3877 static __always_inline void mm_cid_from_cpu(struct task_struct *t, unsigned int cpu_cid, 3878 unsigned int mode) 3879 { 3880 unsigned int max_cids, tcid = t->mm_cid.cid; 3881 struct mm_struct *mm = t->mm; 3882 3883 max_cids = READ_ONCE(mm->mm_cid.max_cids); 3884 /* Optimize for the common case where both have the ONCPU bit set */ 3885 if (likely(cid_on_cpu(cpu_cid & tcid))) { 3886 if (likely(cpu_cid_to_cid(cpu_cid) < max_cids)) { 3887 mm_cid_update_task_cid(t, cpu_cid); 3888 return; 3889 } 3890 /* Try to converge into the optimal CID space */ 3891 cpu_cid = mm_cid_converge(mm, cpu_cid, max_cids); 3892 } else { 3893 /* Hand over or drop the task owned CID */ 3894 if (cid_on_task(tcid)) { 3895 if (cid_on_cpu(cpu_cid)) 3896 mm_unset_cid_on_task(t); 3897 else 3898 cpu_cid = cid_to_cpu_cid(tcid); 3899 } 3900 /* Still nothing, allocate a new one */ 3901 if (!cid_on_cpu(cpu_cid)) 3902 cpu_cid = cid_to_cpu_cid(mm_get_cid(mm)); 3903 3904 /* Handle the transition mode flag if required */ 3905 if (mode & MM_CID_TRANSIT) 3906 cpu_cid = cpu_cid_to_cid(cpu_cid) | MM_CID_TRANSIT; 3907 } 3908 mm_cid_update_pcpu_cid(mm, cpu_cid); 3909 mm_cid_update_task_cid(t, cpu_cid); 3910 } 3911 3912 static __always_inline void mm_cid_from_task(struct task_struct *t, unsigned int cpu_cid, 3913 unsigned int mode) 3914 { 3915 unsigned int max_cids, tcid = t->mm_cid.cid; 3916 struct mm_struct *mm = t->mm; 3917 3918 max_cids = READ_ONCE(mm->mm_cid.max_cids); 3919 /* Optimize for the common case, where both have the ONCPU bit clear */ 3920 if (likely(cid_on_task(tcid | cpu_cid))) { 3921 if (likely(tcid < max_cids)) { 3922 mm_cid_update_pcpu_cid(mm, tcid); 3923 return; 3924 } 3925 /* Try to converge into the optimal CID space */ 3926 tcid = mm_cid_converge(mm, tcid, max_cids); 3927 } else { 3928 /* Hand over or drop the CPU owned CID */ 3929 if (cid_on_cpu(cpu_cid)) { 3930 if (cid_on_task(tcid)) 3931 mm_drop_cid_on_cpu(mm, this_cpu_ptr(mm->mm_cid.pcpu)); 3932 else 3933 tcid = cpu_cid_to_cid(cpu_cid); 3934 } 3935 /* Still nothing, allocate a new one */ 3936 if (!cid_on_task(tcid)) 3937 tcid = mm_get_cid(mm); 3938 /* Set the transition mode flag if required */ 3939 tcid |= mode & MM_CID_TRANSIT; 3940 } 3941 mm_cid_update_pcpu_cid(mm, tcid); 3942 mm_cid_update_task_cid(t, tcid); 3943 } 3944 3945 static __always_inline void mm_cid_schedin(struct task_struct *next) 3946 { 3947 struct mm_struct *mm = next->mm; 3948 unsigned int cpu_cid, mode; 3949 3950 if (!next->mm_cid.active) 3951 return; 3952 3953 cpu_cid = __this_cpu_read(mm->mm_cid.pcpu->cid); 3954 mode = READ_ONCE(mm->mm_cid.mode); 3955 if (likely(!cid_on_cpu(mode))) 3956 mm_cid_from_task(next, cpu_cid, mode); 3957 else 3958 mm_cid_from_cpu(next, cpu_cid, mode); 3959 } 3960 3961 static __always_inline void mm_cid_schedout(struct task_struct *prev) 3962 { 3963 struct mm_struct *mm = prev->mm; 3964 unsigned int mode, cid; 3965 3966 /* During mode transitions CIDs are temporary and need to be dropped */ 3967 if (likely(!cid_in_transit(prev->mm_cid.cid))) 3968 return; 3969 3970 mode = READ_ONCE(mm->mm_cid.mode); 3971 cid = cid_from_transit_cid(prev->mm_cid.cid); 3972 3973 /* 3974 * If transition mode is done, transfer ownership when the CID is 3975 * within the convergence range to optimize the next schedule in. 3976 */ 3977 if (!cid_in_transit(mode) && cid < READ_ONCE(mm->mm_cid.max_cids)) { 3978 if (cid_on_cpu(mode)) 3979 cid = cid_to_cpu_cid(cid); 3980 3981 /* Update both so that the next schedule in goes into the fast path */ 3982 mm_cid_update_pcpu_cid(mm, cid); 3983 prev->mm_cid.cid = cid; 3984 } else { 3985 mm_drop_cid(mm, cid); 3986 prev->mm_cid.cid = MM_CID_UNSET; 3987 } 3988 } 3989 3990 static inline void mm_cid_switch_to(struct task_struct *prev, struct task_struct *next) 3991 { 3992 mm_cid_schedout(prev); 3993 mm_cid_schedin(next); 3994 } 3995 3996 #else /* !CONFIG_SCHED_MM_CID: */ 3997 static inline void mm_cid_switch_to(struct task_struct *prev, struct task_struct *next) { } 3998 #endif /* !CONFIG_SCHED_MM_CID */ 3999 4000 extern u64 avg_vruntime(struct cfs_rq *cfs_rq); 4001 extern int entity_eligible(struct cfs_rq *cfs_rq, struct sched_entity *se); 4002 static inline 4003 void move_queued_task_locked(struct rq *src_rq, struct rq *dst_rq, struct task_struct *task) 4004 { 4005 lockdep_assert_rq_held(src_rq); 4006 lockdep_assert_rq_held(dst_rq); 4007 4008 deactivate_task(src_rq, task, 0); 4009 set_task_cpu(task, dst_rq->cpu); 4010 activate_task(dst_rq, task, 0); 4011 wakeup_preempt(dst_rq, task, 0); 4012 } 4013 4014 static inline 4015 bool task_is_pushable(struct rq *rq, struct task_struct *p, int cpu) 4016 { 4017 if (!task_on_cpu(rq, p) && 4018 cpumask_test_cpu(cpu, &p->cpus_mask)) 4019 return true; 4020 4021 return false; 4022 } 4023 4024 #ifdef CONFIG_RT_MUTEXES 4025 4026 static inline int __rt_effective_prio(struct task_struct *pi_task, int prio) 4027 { 4028 if (pi_task) 4029 prio = min(prio, pi_task->prio); 4030 4031 return prio; 4032 } 4033 4034 static inline int rt_effective_prio(struct task_struct *p, int prio) 4035 { 4036 struct task_struct *pi_task = rt_mutex_get_top_task(p); 4037 4038 return __rt_effective_prio(pi_task, prio); 4039 } 4040 4041 #else /* !CONFIG_RT_MUTEXES: */ 4042 4043 static inline int rt_effective_prio(struct task_struct *p, int prio) 4044 { 4045 return prio; 4046 } 4047 4048 #endif /* !CONFIG_RT_MUTEXES */ 4049 4050 extern int __sched_setscheduler(struct task_struct *p, const struct sched_attr *attr, bool user, bool pi); 4051 extern int __sched_setaffinity(struct task_struct *p, struct affinity_context *ctx); 4052 extern const struct sched_class *__setscheduler_class(int policy, int prio); 4053 extern void set_load_weight(struct task_struct *p, bool update_load); 4054 extern void enqueue_task(struct rq *rq, struct task_struct *p, int flags); 4055 extern bool dequeue_task(struct rq *rq, struct task_struct *p, int flags); 4056 4057 extern struct balance_callback *splice_balance_callbacks(struct rq *rq); 4058 4059 extern void __balance_callbacks(struct rq *rq, struct rq_flags *rf); 4060 extern void balance_callbacks(struct rq *rq, struct balance_callback *head); 4061 4062 /* 4063 * The 'sched_change' pattern is the safe, easy and slow way of changing a 4064 * task's scheduling properties. It dequeues a task, such that the scheduler 4065 * is fully unaware of it; at which point its properties can be modified; 4066 * after which it is enqueued again. 4067 * 4068 * Typically this must be called while holding task_rq_lock, since most/all 4069 * properties are serialized under those locks. There is currently one 4070 * exception to this rule in sched/ext which only holds rq->lock. 4071 */ 4072 4073 /* 4074 * This structure is a temporary, used to preserve/convey the queueing state 4075 * of the task between sched_change_begin() and sched_change_end(). Ensuring 4076 * the task's queueing state is idempotent across the operation. 4077 */ 4078 struct sched_change_ctx { 4079 u64 prio; 4080 struct task_struct *p; 4081 const struct sched_class *class; 4082 int flags; 4083 bool queued; 4084 bool running; 4085 }; 4086 4087 struct sched_change_ctx *sched_change_begin(struct task_struct *p, unsigned int flags); 4088 void sched_change_end(struct sched_change_ctx *ctx); 4089 4090 DEFINE_CLASS(sched_change, struct sched_change_ctx *, 4091 sched_change_end(_T), 4092 sched_change_begin(p, flags), 4093 struct task_struct *p, unsigned int flags) 4094 4095 DEFINE_CLASS_IS_UNCONDITIONAL(sched_change) 4096 4097 #include "ext.h" 4098 4099 #endif /* _KERNEL_SCHED_SCHED_H */ 4100