1 2 #include <linux/sched.h> 3 #include <linux/mutex.h> 4 #include <linux/spinlock.h> 5 #include <linux/stop_machine.h> 6 7 #include "cpupri.h" 8 9 extern __read_mostly int scheduler_running; 10 11 /* 12 * Convert user-nice values [ -20 ... 0 ... 19 ] 13 * to static priority [ MAX_RT_PRIO..MAX_PRIO-1 ], 14 * and back. 15 */ 16 #define NICE_TO_PRIO(nice) (MAX_RT_PRIO + (nice) + 20) 17 #define PRIO_TO_NICE(prio) ((prio) - MAX_RT_PRIO - 20) 18 #define TASK_NICE(p) PRIO_TO_NICE((p)->static_prio) 19 20 /* 21 * 'User priority' is the nice value converted to something we 22 * can work with better when scaling various scheduler parameters, 23 * it's a [ 0 ... 39 ] range. 24 */ 25 #define USER_PRIO(p) ((p)-MAX_RT_PRIO) 26 #define TASK_USER_PRIO(p) USER_PRIO((p)->static_prio) 27 #define MAX_USER_PRIO (USER_PRIO(MAX_PRIO)) 28 29 /* 30 * Helpers for converting nanosecond timing to jiffy resolution 31 */ 32 #define NS_TO_JIFFIES(TIME) ((unsigned long)(TIME) / (NSEC_PER_SEC / HZ)) 33 34 #define NICE_0_LOAD SCHED_LOAD_SCALE 35 #define NICE_0_SHIFT SCHED_LOAD_SHIFT 36 37 /* 38 * These are the 'tuning knobs' of the scheduler: 39 * 40 * default timeslice is 100 msecs (used only for SCHED_RR tasks). 41 * Timeslices get refilled after they expire. 42 */ 43 #define DEF_TIMESLICE (100 * HZ / 1000) 44 45 /* 46 * single value that denotes runtime == period, ie unlimited time. 47 */ 48 #define RUNTIME_INF ((u64)~0ULL) 49 50 static inline int rt_policy(int policy) 51 { 52 if (policy == SCHED_FIFO || policy == SCHED_RR) 53 return 1; 54 return 0; 55 } 56 57 static inline int task_has_rt_policy(struct task_struct *p) 58 { 59 return rt_policy(p->policy); 60 } 61 62 /* 63 * This is the priority-queue data structure of the RT scheduling class: 64 */ 65 struct rt_prio_array { 66 DECLARE_BITMAP(bitmap, MAX_RT_PRIO+1); /* include 1 bit for delimiter */ 67 struct list_head queue[MAX_RT_PRIO]; 68 }; 69 70 struct rt_bandwidth { 71 /* nests inside the rq lock: */ 72 raw_spinlock_t rt_runtime_lock; 73 ktime_t rt_period; 74 u64 rt_runtime; 75 struct hrtimer rt_period_timer; 76 }; 77 78 extern struct mutex sched_domains_mutex; 79 80 #ifdef CONFIG_CGROUP_SCHED 81 82 #include <linux/cgroup.h> 83 84 struct cfs_rq; 85 struct rt_rq; 86 87 static LIST_HEAD(task_groups); 88 89 struct cfs_bandwidth { 90 #ifdef CONFIG_CFS_BANDWIDTH 91 raw_spinlock_t lock; 92 ktime_t period; 93 u64 quota, runtime; 94 s64 hierarchal_quota; 95 u64 runtime_expires; 96 97 int idle, timer_active; 98 struct hrtimer period_timer, slack_timer; 99 struct list_head throttled_cfs_rq; 100 101 /* statistics */ 102 int nr_periods, nr_throttled; 103 u64 throttled_time; 104 #endif 105 }; 106 107 /* task group related information */ 108 struct task_group { 109 struct cgroup_subsys_state css; 110 111 #ifdef CONFIG_FAIR_GROUP_SCHED 112 /* schedulable entities of this group on each cpu */ 113 struct sched_entity **se; 114 /* runqueue "owned" by this group on each cpu */ 115 struct cfs_rq **cfs_rq; 116 unsigned long shares; 117 118 atomic_t load_weight; 119 #endif 120 121 #ifdef CONFIG_RT_GROUP_SCHED 122 struct sched_rt_entity **rt_se; 123 struct rt_rq **rt_rq; 124 125 struct rt_bandwidth rt_bandwidth; 126 #endif 127 128 struct rcu_head rcu; 129 struct list_head list; 130 131 struct task_group *parent; 132 struct list_head siblings; 133 struct list_head children; 134 135 #ifdef CONFIG_SCHED_AUTOGROUP 136 struct autogroup *autogroup; 137 #endif 138 139 struct cfs_bandwidth cfs_bandwidth; 140 }; 141 142 #ifdef CONFIG_FAIR_GROUP_SCHED 143 #define ROOT_TASK_GROUP_LOAD NICE_0_LOAD 144 145 /* 146 * A weight of 0 or 1 can cause arithmetics problems. 147 * A weight of a cfs_rq is the sum of weights of which entities 148 * are queued on this cfs_rq, so a weight of a entity should not be 149 * too large, so as the shares value of a task group. 150 * (The default weight is 1024 - so there's no practical 151 * limitation from this.) 152 */ 153 #define MIN_SHARES (1UL << 1) 154 #define MAX_SHARES (1UL << 18) 155 #endif 156 157 /* Default task group. 158 * Every task in system belong to this group at bootup. 159 */ 160 extern struct task_group root_task_group; 161 162 typedef int (*tg_visitor)(struct task_group *, void *); 163 164 extern int walk_tg_tree_from(struct task_group *from, 165 tg_visitor down, tg_visitor up, void *data); 166 167 /* 168 * Iterate the full tree, calling @down when first entering a node and @up when 169 * leaving it for the final time. 170 * 171 * Caller must hold rcu_lock or sufficient equivalent. 172 */ 173 static inline int walk_tg_tree(tg_visitor down, tg_visitor up, void *data) 174 { 175 return walk_tg_tree_from(&root_task_group, down, up, data); 176 } 177 178 extern int tg_nop(struct task_group *tg, void *data); 179 180 extern void free_fair_sched_group(struct task_group *tg); 181 extern int alloc_fair_sched_group(struct task_group *tg, struct task_group *parent); 182 extern void unregister_fair_sched_group(struct task_group *tg, int cpu); 183 extern void init_tg_cfs_entry(struct task_group *tg, struct cfs_rq *cfs_rq, 184 struct sched_entity *se, int cpu, 185 struct sched_entity *parent); 186 extern void init_cfs_bandwidth(struct cfs_bandwidth *cfs_b); 187 extern int sched_group_set_shares(struct task_group *tg, unsigned long shares); 188 189 extern void __refill_cfs_bandwidth_runtime(struct cfs_bandwidth *cfs_b); 190 extern void __start_cfs_bandwidth(struct cfs_bandwidth *cfs_b); 191 extern void unthrottle_cfs_rq(struct cfs_rq *cfs_rq); 192 193 extern void free_rt_sched_group(struct task_group *tg); 194 extern int alloc_rt_sched_group(struct task_group *tg, struct task_group *parent); 195 extern void init_tg_rt_entry(struct task_group *tg, struct rt_rq *rt_rq, 196 struct sched_rt_entity *rt_se, int cpu, 197 struct sched_rt_entity *parent); 198 199 #else /* CONFIG_CGROUP_SCHED */ 200 201 struct cfs_bandwidth { }; 202 203 #endif /* CONFIG_CGROUP_SCHED */ 204 205 /* CFS-related fields in a runqueue */ 206 struct cfs_rq { 207 struct load_weight load; 208 unsigned long nr_running, h_nr_running; 209 210 u64 exec_clock; 211 u64 min_vruntime; 212 #ifndef CONFIG_64BIT 213 u64 min_vruntime_copy; 214 #endif 215 216 struct rb_root tasks_timeline; 217 struct rb_node *rb_leftmost; 218 219 struct list_head tasks; 220 struct list_head *balance_iterator; 221 222 /* 223 * 'curr' points to currently running entity on this cfs_rq. 224 * It is set to NULL otherwise (i.e when none are currently running). 225 */ 226 struct sched_entity *curr, *next, *last, *skip; 227 228 #ifdef CONFIG_SCHED_DEBUG 229 unsigned int nr_spread_over; 230 #endif 231 232 #ifdef CONFIG_FAIR_GROUP_SCHED 233 struct rq *rq; /* cpu runqueue to which this cfs_rq is attached */ 234 235 /* 236 * leaf cfs_rqs are those that hold tasks (lowest schedulable entity in 237 * a hierarchy). Non-leaf lrqs hold other higher schedulable entities 238 * (like users, containers etc.) 239 * 240 * leaf_cfs_rq_list ties together list of leaf cfs_rq's in a cpu. This 241 * list is used during load balance. 242 */ 243 int on_list; 244 struct list_head leaf_cfs_rq_list; 245 struct task_group *tg; /* group that "owns" this runqueue */ 246 247 #ifdef CONFIG_SMP 248 /* 249 * the part of load.weight contributed by tasks 250 */ 251 unsigned long task_weight; 252 253 /* 254 * h_load = weight * f(tg) 255 * 256 * Where f(tg) is the recursive weight fraction assigned to 257 * this group. 258 */ 259 unsigned long h_load; 260 261 /* 262 * Maintaining per-cpu shares distribution for group scheduling 263 * 264 * load_stamp is the last time we updated the load average 265 * load_last is the last time we updated the load average and saw load 266 * load_unacc_exec_time is currently unaccounted execution time 267 */ 268 u64 load_avg; 269 u64 load_period; 270 u64 load_stamp, load_last, load_unacc_exec_time; 271 272 unsigned long load_contribution; 273 #endif /* CONFIG_SMP */ 274 #ifdef CONFIG_CFS_BANDWIDTH 275 int runtime_enabled; 276 u64 runtime_expires; 277 s64 runtime_remaining; 278 279 u64 throttled_timestamp; 280 int throttled, throttle_count; 281 struct list_head throttled_list; 282 #endif /* CONFIG_CFS_BANDWIDTH */ 283 #endif /* CONFIG_FAIR_GROUP_SCHED */ 284 }; 285 286 static inline int rt_bandwidth_enabled(void) 287 { 288 return sysctl_sched_rt_runtime >= 0; 289 } 290 291 /* Real-Time classes' related field in a runqueue: */ 292 struct rt_rq { 293 struct rt_prio_array active; 294 unsigned long rt_nr_running; 295 #if defined CONFIG_SMP || defined CONFIG_RT_GROUP_SCHED 296 struct { 297 int curr; /* highest queued rt task prio */ 298 #ifdef CONFIG_SMP 299 int next; /* next highest */ 300 #endif 301 } highest_prio; 302 #endif 303 #ifdef CONFIG_SMP 304 unsigned long rt_nr_migratory; 305 unsigned long rt_nr_total; 306 int overloaded; 307 struct plist_head pushable_tasks; 308 #endif 309 int rt_throttled; 310 u64 rt_time; 311 u64 rt_runtime; 312 /* Nests inside the rq lock: */ 313 raw_spinlock_t rt_runtime_lock; 314 315 #ifdef CONFIG_RT_GROUP_SCHED 316 unsigned long rt_nr_boosted; 317 318 struct rq *rq; 319 struct list_head leaf_rt_rq_list; 320 struct task_group *tg; 321 #endif 322 }; 323 324 #ifdef CONFIG_SMP 325 326 /* 327 * We add the notion of a root-domain which will be used to define per-domain 328 * variables. Each exclusive cpuset essentially defines an island domain by 329 * fully partitioning the member cpus from any other cpuset. Whenever a new 330 * exclusive cpuset is created, we also create and attach a new root-domain 331 * object. 332 * 333 */ 334 struct root_domain { 335 atomic_t refcount; 336 atomic_t rto_count; 337 struct rcu_head rcu; 338 cpumask_var_t span; 339 cpumask_var_t online; 340 341 /* 342 * The "RT overload" flag: it gets set if a CPU has more than 343 * one runnable RT task. 344 */ 345 cpumask_var_t rto_mask; 346 struct cpupri cpupri; 347 }; 348 349 extern struct root_domain def_root_domain; 350 351 #endif /* CONFIG_SMP */ 352 353 /* 354 * This is the main, per-CPU runqueue data structure. 355 * 356 * Locking rule: those places that want to lock multiple runqueues 357 * (such as the load balancing or the thread migration code), lock 358 * acquire operations must be ordered by ascending &runqueue. 359 */ 360 struct rq { 361 /* runqueue lock: */ 362 raw_spinlock_t lock; 363 364 /* 365 * nr_running and cpu_load should be in the same cacheline because 366 * remote CPUs use both these fields when doing load calculation. 367 */ 368 unsigned long nr_running; 369 #define CPU_LOAD_IDX_MAX 5 370 unsigned long cpu_load[CPU_LOAD_IDX_MAX]; 371 unsigned long last_load_update_tick; 372 #ifdef CONFIG_NO_HZ 373 u64 nohz_stamp; 374 unsigned char nohz_balance_kick; 375 #endif 376 int skip_clock_update; 377 378 /* capture load from *all* tasks on this cpu: */ 379 struct load_weight load; 380 unsigned long nr_load_updates; 381 u64 nr_switches; 382 383 struct cfs_rq cfs; 384 struct rt_rq rt; 385 386 #ifdef CONFIG_FAIR_GROUP_SCHED 387 /* list of leaf cfs_rq on this cpu: */ 388 struct list_head leaf_cfs_rq_list; 389 #endif 390 #ifdef CONFIG_RT_GROUP_SCHED 391 struct list_head leaf_rt_rq_list; 392 #endif 393 394 /* 395 * This is part of a global counter where only the total sum 396 * over all CPUs matters. A task can increase this counter on 397 * one CPU and if it got migrated afterwards it may decrease 398 * it on another CPU. Always updated under the runqueue lock: 399 */ 400 unsigned long nr_uninterruptible; 401 402 struct task_struct *curr, *idle, *stop; 403 unsigned long next_balance; 404 struct mm_struct *prev_mm; 405 406 u64 clock; 407 u64 clock_task; 408 409 atomic_t nr_iowait; 410 411 #ifdef CONFIG_SMP 412 struct root_domain *rd; 413 struct sched_domain *sd; 414 415 unsigned long cpu_power; 416 417 unsigned char idle_balance; 418 /* For active balancing */ 419 int post_schedule; 420 int active_balance; 421 int push_cpu; 422 struct cpu_stop_work active_balance_work; 423 /* cpu of this runqueue: */ 424 int cpu; 425 int online; 426 427 u64 rt_avg; 428 u64 age_stamp; 429 u64 idle_stamp; 430 u64 avg_idle; 431 #endif 432 433 #ifdef CONFIG_IRQ_TIME_ACCOUNTING 434 u64 prev_irq_time; 435 #endif 436 #ifdef CONFIG_PARAVIRT 437 u64 prev_steal_time; 438 #endif 439 #ifdef CONFIG_PARAVIRT_TIME_ACCOUNTING 440 u64 prev_steal_time_rq; 441 #endif 442 443 /* calc_load related fields */ 444 unsigned long calc_load_update; 445 long calc_load_active; 446 447 #ifdef CONFIG_SCHED_HRTICK 448 #ifdef CONFIG_SMP 449 int hrtick_csd_pending; 450 struct call_single_data hrtick_csd; 451 #endif 452 struct hrtimer hrtick_timer; 453 #endif 454 455 #ifdef CONFIG_SCHEDSTATS 456 /* latency stats */ 457 struct sched_info rq_sched_info; 458 unsigned long long rq_cpu_time; 459 /* could above be rq->cfs_rq.exec_clock + rq->rt_rq.rt_runtime ? */ 460 461 /* sys_sched_yield() stats */ 462 unsigned int yld_count; 463 464 /* schedule() stats */ 465 unsigned int sched_switch; 466 unsigned int sched_count; 467 unsigned int sched_goidle; 468 469 /* try_to_wake_up() stats */ 470 unsigned int ttwu_count; 471 unsigned int ttwu_local; 472 #endif 473 474 #ifdef CONFIG_SMP 475 struct llist_head wake_list; 476 #endif 477 }; 478 479 static inline int cpu_of(struct rq *rq) 480 { 481 #ifdef CONFIG_SMP 482 return rq->cpu; 483 #else 484 return 0; 485 #endif 486 } 487 488 DECLARE_PER_CPU(struct rq, runqueues); 489 490 #define rcu_dereference_check_sched_domain(p) \ 491 rcu_dereference_check((p), \ 492 lockdep_is_held(&sched_domains_mutex)) 493 494 /* 495 * The domain tree (rq->sd) is protected by RCU's quiescent state transition. 496 * See detach_destroy_domains: synchronize_sched for details. 497 * 498 * The domain tree of any CPU may only be accessed from within 499 * preempt-disabled sections. 500 */ 501 #define for_each_domain(cpu, __sd) \ 502 for (__sd = rcu_dereference_check_sched_domain(cpu_rq(cpu)->sd); __sd; __sd = __sd->parent) 503 504 #define cpu_rq(cpu) (&per_cpu(runqueues, (cpu))) 505 #define this_rq() (&__get_cpu_var(runqueues)) 506 #define task_rq(p) cpu_rq(task_cpu(p)) 507 #define cpu_curr(cpu) (cpu_rq(cpu)->curr) 508 #define raw_rq() (&__raw_get_cpu_var(runqueues)) 509 510 #include "stats.h" 511 #include "auto_group.h" 512 513 #ifdef CONFIG_CGROUP_SCHED 514 515 /* 516 * Return the group to which this tasks belongs. 517 * 518 * We use task_subsys_state_check() and extend the RCU verification with 519 * pi->lock and rq->lock because cpu_cgroup_attach() holds those locks for each 520 * task it moves into the cgroup. Therefore by holding either of those locks, 521 * we pin the task to the current cgroup. 522 */ 523 static inline struct task_group *task_group(struct task_struct *p) 524 { 525 struct task_group *tg; 526 struct cgroup_subsys_state *css; 527 528 css = task_subsys_state_check(p, cpu_cgroup_subsys_id, 529 lockdep_is_held(&p->pi_lock) || 530 lockdep_is_held(&task_rq(p)->lock)); 531 tg = container_of(css, struct task_group, css); 532 533 return autogroup_task_group(p, tg); 534 } 535 536 /* Change a task's cfs_rq and parent entity if it moves across CPUs/groups */ 537 static inline void set_task_rq(struct task_struct *p, unsigned int cpu) 538 { 539 #if defined(CONFIG_FAIR_GROUP_SCHED) || defined(CONFIG_RT_GROUP_SCHED) 540 struct task_group *tg = task_group(p); 541 #endif 542 543 #ifdef CONFIG_FAIR_GROUP_SCHED 544 p->se.cfs_rq = tg->cfs_rq[cpu]; 545 p->se.parent = tg->se[cpu]; 546 #endif 547 548 #ifdef CONFIG_RT_GROUP_SCHED 549 p->rt.rt_rq = tg->rt_rq[cpu]; 550 p->rt.parent = tg->rt_se[cpu]; 551 #endif 552 } 553 554 #else /* CONFIG_CGROUP_SCHED */ 555 556 static inline void set_task_rq(struct task_struct *p, unsigned int cpu) { } 557 static inline struct task_group *task_group(struct task_struct *p) 558 { 559 return NULL; 560 } 561 562 #endif /* CONFIG_CGROUP_SCHED */ 563 564 static inline void __set_task_cpu(struct task_struct *p, unsigned int cpu) 565 { 566 set_task_rq(p, cpu); 567 #ifdef CONFIG_SMP 568 /* 569 * After ->cpu is set up to a new value, task_rq_lock(p, ...) can be 570 * successfuly executed on another CPU. We must ensure that updates of 571 * per-task data have been completed by this moment. 572 */ 573 smp_wmb(); 574 task_thread_info(p)->cpu = cpu; 575 #endif 576 } 577 578 /* 579 * Tunables that become constants when CONFIG_SCHED_DEBUG is off: 580 */ 581 #ifdef CONFIG_SCHED_DEBUG 582 # define const_debug __read_mostly 583 #else 584 # define const_debug const 585 #endif 586 587 extern const_debug unsigned int sysctl_sched_features; 588 589 #define SCHED_FEAT(name, enabled) \ 590 __SCHED_FEAT_##name , 591 592 enum { 593 #include "features.h" 594 }; 595 596 #undef SCHED_FEAT 597 598 #define sched_feat(x) (sysctl_sched_features & (1UL << __SCHED_FEAT_##x)) 599 600 static inline u64 global_rt_period(void) 601 { 602 return (u64)sysctl_sched_rt_period * NSEC_PER_USEC; 603 } 604 605 static inline u64 global_rt_runtime(void) 606 { 607 if (sysctl_sched_rt_runtime < 0) 608 return RUNTIME_INF; 609 610 return (u64)sysctl_sched_rt_runtime * NSEC_PER_USEC; 611 } 612 613 614 615 static inline int task_current(struct rq *rq, struct task_struct *p) 616 { 617 return rq->curr == p; 618 } 619 620 static inline int task_running(struct rq *rq, struct task_struct *p) 621 { 622 #ifdef CONFIG_SMP 623 return p->on_cpu; 624 #else 625 return task_current(rq, p); 626 #endif 627 } 628 629 630 #ifndef prepare_arch_switch 631 # define prepare_arch_switch(next) do { } while (0) 632 #endif 633 #ifndef finish_arch_switch 634 # define finish_arch_switch(prev) do { } while (0) 635 #endif 636 637 #ifndef __ARCH_WANT_UNLOCKED_CTXSW 638 static inline void prepare_lock_switch(struct rq *rq, struct task_struct *next) 639 { 640 #ifdef CONFIG_SMP 641 /* 642 * We can optimise this out completely for !SMP, because the 643 * SMP rebalancing from interrupt is the only thing that cares 644 * here. 645 */ 646 next->on_cpu = 1; 647 #endif 648 } 649 650 static inline void finish_lock_switch(struct rq *rq, struct task_struct *prev) 651 { 652 #ifdef CONFIG_SMP 653 /* 654 * After ->on_cpu is cleared, the task can be moved to a different CPU. 655 * We must ensure this doesn't happen until the switch is completely 656 * finished. 657 */ 658 smp_wmb(); 659 prev->on_cpu = 0; 660 #endif 661 #ifdef CONFIG_DEBUG_SPINLOCK 662 /* this is a valid case when another task releases the spinlock */ 663 rq->lock.owner = current; 664 #endif 665 /* 666 * If we are tracking spinlock dependencies then we have to 667 * fix up the runqueue lock - which gets 'carried over' from 668 * prev into current: 669 */ 670 spin_acquire(&rq->lock.dep_map, 0, 0, _THIS_IP_); 671 672 raw_spin_unlock_irq(&rq->lock); 673 } 674 675 #else /* __ARCH_WANT_UNLOCKED_CTXSW */ 676 static inline void prepare_lock_switch(struct rq *rq, struct task_struct *next) 677 { 678 #ifdef CONFIG_SMP 679 /* 680 * We can optimise this out completely for !SMP, because the 681 * SMP rebalancing from interrupt is the only thing that cares 682 * here. 683 */ 684 next->on_cpu = 1; 685 #endif 686 #ifdef __ARCH_WANT_INTERRUPTS_ON_CTXSW 687 raw_spin_unlock_irq(&rq->lock); 688 #else 689 raw_spin_unlock(&rq->lock); 690 #endif 691 } 692 693 static inline void finish_lock_switch(struct rq *rq, struct task_struct *prev) 694 { 695 #ifdef CONFIG_SMP 696 /* 697 * After ->on_cpu is cleared, the task can be moved to a different CPU. 698 * We must ensure this doesn't happen until the switch is completely 699 * finished. 700 */ 701 smp_wmb(); 702 prev->on_cpu = 0; 703 #endif 704 #ifndef __ARCH_WANT_INTERRUPTS_ON_CTXSW 705 local_irq_enable(); 706 #endif 707 } 708 #endif /* __ARCH_WANT_UNLOCKED_CTXSW */ 709 710 711 static inline void update_load_add(struct load_weight *lw, unsigned long inc) 712 { 713 lw->weight += inc; 714 lw->inv_weight = 0; 715 } 716 717 static inline void update_load_sub(struct load_weight *lw, unsigned long dec) 718 { 719 lw->weight -= dec; 720 lw->inv_weight = 0; 721 } 722 723 static inline void update_load_set(struct load_weight *lw, unsigned long w) 724 { 725 lw->weight = w; 726 lw->inv_weight = 0; 727 } 728 729 /* 730 * To aid in avoiding the subversion of "niceness" due to uneven distribution 731 * of tasks with abnormal "nice" values across CPUs the contribution that 732 * each task makes to its run queue's load is weighted according to its 733 * scheduling class and "nice" value. For SCHED_NORMAL tasks this is just a 734 * scaled version of the new time slice allocation that they receive on time 735 * slice expiry etc. 736 */ 737 738 #define WEIGHT_IDLEPRIO 3 739 #define WMULT_IDLEPRIO 1431655765 740 741 /* 742 * Nice levels are multiplicative, with a gentle 10% change for every 743 * nice level changed. I.e. when a CPU-bound task goes from nice 0 to 744 * nice 1, it will get ~10% less CPU time than another CPU-bound task 745 * that remained on nice 0. 746 * 747 * The "10% effect" is relative and cumulative: from _any_ nice level, 748 * if you go up 1 level, it's -10% CPU usage, if you go down 1 level 749 * it's +10% CPU usage. (to achieve that we use a multiplier of 1.25. 750 * If a task goes up by ~10% and another task goes down by ~10% then 751 * the relative distance between them is ~25%.) 752 */ 753 static const int prio_to_weight[40] = { 754 /* -20 */ 88761, 71755, 56483, 46273, 36291, 755 /* -15 */ 29154, 23254, 18705, 14949, 11916, 756 /* -10 */ 9548, 7620, 6100, 4904, 3906, 757 /* -5 */ 3121, 2501, 1991, 1586, 1277, 758 /* 0 */ 1024, 820, 655, 526, 423, 759 /* 5 */ 335, 272, 215, 172, 137, 760 /* 10 */ 110, 87, 70, 56, 45, 761 /* 15 */ 36, 29, 23, 18, 15, 762 }; 763 764 /* 765 * Inverse (2^32/x) values of the prio_to_weight[] array, precalculated. 766 * 767 * In cases where the weight does not change often, we can use the 768 * precalculated inverse to speed up arithmetics by turning divisions 769 * into multiplications: 770 */ 771 static const u32 prio_to_wmult[40] = { 772 /* -20 */ 48388, 59856, 76040, 92818, 118348, 773 /* -15 */ 147320, 184698, 229616, 287308, 360437, 774 /* -10 */ 449829, 563644, 704093, 875809, 1099582, 775 /* -5 */ 1376151, 1717300, 2157191, 2708050, 3363326, 776 /* 0 */ 4194304, 5237765, 6557202, 8165337, 10153587, 777 /* 5 */ 12820798, 15790321, 19976592, 24970740, 31350126, 778 /* 10 */ 39045157, 49367440, 61356676, 76695844, 95443717, 779 /* 15 */ 119304647, 148102320, 186737708, 238609294, 286331153, 780 }; 781 782 /* Time spent by the tasks of the cpu accounting group executing in ... */ 783 enum cpuacct_stat_index { 784 CPUACCT_STAT_USER, /* ... user mode */ 785 CPUACCT_STAT_SYSTEM, /* ... kernel mode */ 786 787 CPUACCT_STAT_NSTATS, 788 }; 789 790 791 #define sched_class_highest (&stop_sched_class) 792 #define for_each_class(class) \ 793 for (class = sched_class_highest; class; class = class->next) 794 795 extern const struct sched_class stop_sched_class; 796 extern const struct sched_class rt_sched_class; 797 extern const struct sched_class fair_sched_class; 798 extern const struct sched_class idle_sched_class; 799 800 801 #ifdef CONFIG_SMP 802 803 extern void trigger_load_balance(struct rq *rq, int cpu); 804 extern void idle_balance(int this_cpu, struct rq *this_rq); 805 806 #else /* CONFIG_SMP */ 807 808 static inline void idle_balance(int cpu, struct rq *rq) 809 { 810 } 811 812 #endif 813 814 extern void sysrq_sched_debug_show(void); 815 extern void sched_init_granularity(void); 816 extern void update_max_interval(void); 817 extern void update_group_power(struct sched_domain *sd, int cpu); 818 extern int update_runtime(struct notifier_block *nfb, unsigned long action, void *hcpu); 819 extern void init_sched_rt_class(void); 820 extern void init_sched_fair_class(void); 821 822 extern void resched_task(struct task_struct *p); 823 extern void resched_cpu(int cpu); 824 825 extern struct rt_bandwidth def_rt_bandwidth; 826 extern void init_rt_bandwidth(struct rt_bandwidth *rt_b, u64 period, u64 runtime); 827 828 extern void update_cpu_load(struct rq *this_rq); 829 830 #ifdef CONFIG_CGROUP_CPUACCT 831 extern void cpuacct_charge(struct task_struct *tsk, u64 cputime); 832 extern void cpuacct_update_stats(struct task_struct *tsk, 833 enum cpuacct_stat_index idx, cputime_t val); 834 #else 835 static inline void cpuacct_charge(struct task_struct *tsk, u64 cputime) {} 836 static inline void cpuacct_update_stats(struct task_struct *tsk, 837 enum cpuacct_stat_index idx, cputime_t val) {} 838 #endif 839 840 static inline void inc_nr_running(struct rq *rq) 841 { 842 rq->nr_running++; 843 } 844 845 static inline void dec_nr_running(struct rq *rq) 846 { 847 rq->nr_running--; 848 } 849 850 extern void update_rq_clock(struct rq *rq); 851 852 extern void activate_task(struct rq *rq, struct task_struct *p, int flags); 853 extern void deactivate_task(struct rq *rq, struct task_struct *p, int flags); 854 855 extern void check_preempt_curr(struct rq *rq, struct task_struct *p, int flags); 856 857 extern const_debug unsigned int sysctl_sched_time_avg; 858 extern const_debug unsigned int sysctl_sched_nr_migrate; 859 extern const_debug unsigned int sysctl_sched_migration_cost; 860 861 static inline u64 sched_avg_period(void) 862 { 863 return (u64)sysctl_sched_time_avg * NSEC_PER_MSEC / 2; 864 } 865 866 void calc_load_account_idle(struct rq *this_rq); 867 868 #ifdef CONFIG_SCHED_HRTICK 869 870 /* 871 * Use hrtick when: 872 * - enabled by features 873 * - hrtimer is actually high res 874 */ 875 static inline int hrtick_enabled(struct rq *rq) 876 { 877 if (!sched_feat(HRTICK)) 878 return 0; 879 if (!cpu_active(cpu_of(rq))) 880 return 0; 881 return hrtimer_is_hres_active(&rq->hrtick_timer); 882 } 883 884 void hrtick_start(struct rq *rq, u64 delay); 885 886 #endif /* CONFIG_SCHED_HRTICK */ 887 888 #ifdef CONFIG_SMP 889 extern void sched_avg_update(struct rq *rq); 890 static inline void sched_rt_avg_update(struct rq *rq, u64 rt_delta) 891 { 892 rq->rt_avg += rt_delta; 893 sched_avg_update(rq); 894 } 895 #else 896 static inline void sched_rt_avg_update(struct rq *rq, u64 rt_delta) { } 897 static inline void sched_avg_update(struct rq *rq) { } 898 #endif 899 900 extern void start_bandwidth_timer(struct hrtimer *period_timer, ktime_t period); 901 902 #ifdef CONFIG_SMP 903 #ifdef CONFIG_PREEMPT 904 905 static inline void double_rq_lock(struct rq *rq1, struct rq *rq2); 906 907 /* 908 * fair double_lock_balance: Safely acquires both rq->locks in a fair 909 * way at the expense of forcing extra atomic operations in all 910 * invocations. This assures that the double_lock is acquired using the 911 * same underlying policy as the spinlock_t on this architecture, which 912 * reduces latency compared to the unfair variant below. However, it 913 * also adds more overhead and therefore may reduce throughput. 914 */ 915 static inline int _double_lock_balance(struct rq *this_rq, struct rq *busiest) 916 __releases(this_rq->lock) 917 __acquires(busiest->lock) 918 __acquires(this_rq->lock) 919 { 920 raw_spin_unlock(&this_rq->lock); 921 double_rq_lock(this_rq, busiest); 922 923 return 1; 924 } 925 926 #else 927 /* 928 * Unfair double_lock_balance: Optimizes throughput at the expense of 929 * latency by eliminating extra atomic operations when the locks are 930 * already in proper order on entry. This favors lower cpu-ids and will 931 * grant the double lock to lower cpus over higher ids under contention, 932 * regardless of entry order into the function. 933 */ 934 static inline int _double_lock_balance(struct rq *this_rq, struct rq *busiest) 935 __releases(this_rq->lock) 936 __acquires(busiest->lock) 937 __acquires(this_rq->lock) 938 { 939 int ret = 0; 940 941 if (unlikely(!raw_spin_trylock(&busiest->lock))) { 942 if (busiest < this_rq) { 943 raw_spin_unlock(&this_rq->lock); 944 raw_spin_lock(&busiest->lock); 945 raw_spin_lock_nested(&this_rq->lock, 946 SINGLE_DEPTH_NESTING); 947 ret = 1; 948 } else 949 raw_spin_lock_nested(&busiest->lock, 950 SINGLE_DEPTH_NESTING); 951 } 952 return ret; 953 } 954 955 #endif /* CONFIG_PREEMPT */ 956 957 /* 958 * double_lock_balance - lock the busiest runqueue, this_rq is locked already. 959 */ 960 static inline int double_lock_balance(struct rq *this_rq, struct rq *busiest) 961 { 962 if (unlikely(!irqs_disabled())) { 963 /* printk() doesn't work good under rq->lock */ 964 raw_spin_unlock(&this_rq->lock); 965 BUG_ON(1); 966 } 967 968 return _double_lock_balance(this_rq, busiest); 969 } 970 971 static inline void double_unlock_balance(struct rq *this_rq, struct rq *busiest) 972 __releases(busiest->lock) 973 { 974 raw_spin_unlock(&busiest->lock); 975 lock_set_subclass(&this_rq->lock.dep_map, 0, _RET_IP_); 976 } 977 978 /* 979 * double_rq_lock - safely lock two runqueues 980 * 981 * Note this does not disable interrupts like task_rq_lock, 982 * you need to do so manually before calling. 983 */ 984 static inline void double_rq_lock(struct rq *rq1, struct rq *rq2) 985 __acquires(rq1->lock) 986 __acquires(rq2->lock) 987 { 988 BUG_ON(!irqs_disabled()); 989 if (rq1 == rq2) { 990 raw_spin_lock(&rq1->lock); 991 __acquire(rq2->lock); /* Fake it out ;) */ 992 } else { 993 if (rq1 < rq2) { 994 raw_spin_lock(&rq1->lock); 995 raw_spin_lock_nested(&rq2->lock, SINGLE_DEPTH_NESTING); 996 } else { 997 raw_spin_lock(&rq2->lock); 998 raw_spin_lock_nested(&rq1->lock, SINGLE_DEPTH_NESTING); 999 } 1000 } 1001 } 1002 1003 /* 1004 * double_rq_unlock - safely unlock two runqueues 1005 * 1006 * Note this does not restore interrupts like task_rq_unlock, 1007 * you need to do so manually after calling. 1008 */ 1009 static inline void double_rq_unlock(struct rq *rq1, struct rq *rq2) 1010 __releases(rq1->lock) 1011 __releases(rq2->lock) 1012 { 1013 raw_spin_unlock(&rq1->lock); 1014 if (rq1 != rq2) 1015 raw_spin_unlock(&rq2->lock); 1016 else 1017 __release(rq2->lock); 1018 } 1019 1020 #else /* CONFIG_SMP */ 1021 1022 /* 1023 * double_rq_lock - safely lock two runqueues 1024 * 1025 * Note this does not disable interrupts like task_rq_lock, 1026 * you need to do so manually before calling. 1027 */ 1028 static inline void double_rq_lock(struct rq *rq1, struct rq *rq2) 1029 __acquires(rq1->lock) 1030 __acquires(rq2->lock) 1031 { 1032 BUG_ON(!irqs_disabled()); 1033 BUG_ON(rq1 != rq2); 1034 raw_spin_lock(&rq1->lock); 1035 __acquire(rq2->lock); /* Fake it out ;) */ 1036 } 1037 1038 /* 1039 * double_rq_unlock - safely unlock two runqueues 1040 * 1041 * Note this does not restore interrupts like task_rq_unlock, 1042 * you need to do so manually after calling. 1043 */ 1044 static inline void double_rq_unlock(struct rq *rq1, struct rq *rq2) 1045 __releases(rq1->lock) 1046 __releases(rq2->lock) 1047 { 1048 BUG_ON(rq1 != rq2); 1049 raw_spin_unlock(&rq1->lock); 1050 __release(rq2->lock); 1051 } 1052 1053 #endif 1054 1055 extern struct sched_entity *__pick_first_entity(struct cfs_rq *cfs_rq); 1056 extern struct sched_entity *__pick_last_entity(struct cfs_rq *cfs_rq); 1057 extern void print_cfs_stats(struct seq_file *m, int cpu); 1058 extern void print_rt_stats(struct seq_file *m, int cpu); 1059 1060 extern void init_cfs_rq(struct cfs_rq *cfs_rq); 1061 extern void init_rt_rq(struct rt_rq *rt_rq, struct rq *rq); 1062 extern void unthrottle_offline_cfs_rqs(struct rq *rq); 1063 1064 extern void account_cfs_bandwidth_used(int enabled, int was_enabled); 1065