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1da177e4 LT |
1 | /* |
2 | * kernel/sched.c | |
3 | * | |
4 | * Kernel scheduler and related syscalls | |
5 | * | |
6 | * Copyright (C) 1991-2002 Linus Torvalds | |
7 | * | |
8 | * 1996-12-23 Modified by Dave Grothe to fix bugs in semaphores and | |
9 | * make semaphores SMP safe | |
10 | * 1998-11-19 Implemented schedule_timeout() and related stuff | |
11 | * by Andrea Arcangeli | |
12 | * 2002-01-04 New ultra-scalable O(1) scheduler by Ingo Molnar: | |
13 | * hybrid priority-list and round-robin design with | |
14 | * an array-switch method of distributing timeslices | |
15 | * and per-CPU runqueues. Cleanups and useful suggestions | |
16 | * by Davide Libenzi, preemptible kernel bits by Robert Love. | |
17 | * 2003-09-03 Interactivity tuning by Con Kolivas. | |
18 | * 2004-04-02 Scheduler domains code by Nick Piggin | |
c31f2e8a IM |
19 | * 2007-04-15 Work begun on replacing all interactivity tuning with a |
20 | * fair scheduling design by Con Kolivas. | |
21 | * 2007-05-05 Load balancing (smp-nice) and other improvements | |
22 | * by Peter Williams | |
23 | * 2007-05-06 Interactivity improvements to CFS by Mike Galbraith | |
24 | * 2007-07-01 Group scheduling enhancements by Srivatsa Vaddagiri | |
b9131769 IM |
25 | * 2007-11-29 RT balancing improvements by Steven Rostedt, Gregory Haskins, |
26 | * Thomas Gleixner, Mike Kravetz | |
1da177e4 LT |
27 | */ |
28 | ||
29 | #include <linux/mm.h> | |
30 | #include <linux/module.h> | |
31 | #include <linux/nmi.h> | |
32 | #include <linux/init.h> | |
dff06c15 | 33 | #include <linux/uaccess.h> |
1da177e4 LT |
34 | #include <linux/highmem.h> |
35 | #include <linux/smp_lock.h> | |
36 | #include <asm/mmu_context.h> | |
37 | #include <linux/interrupt.h> | |
c59ede7b | 38 | #include <linux/capability.h> |
1da177e4 LT |
39 | #include <linux/completion.h> |
40 | #include <linux/kernel_stat.h> | |
9a11b49a | 41 | #include <linux/debug_locks.h> |
cdd6c482 | 42 | #include <linux/perf_event.h> |
1da177e4 LT |
43 | #include <linux/security.h> |
44 | #include <linux/notifier.h> | |
45 | #include <linux/profile.h> | |
7dfb7103 | 46 | #include <linux/freezer.h> |
198e2f18 | 47 | #include <linux/vmalloc.h> |
1da177e4 LT |
48 | #include <linux/blkdev.h> |
49 | #include <linux/delay.h> | |
b488893a | 50 | #include <linux/pid_namespace.h> |
1da177e4 LT |
51 | #include <linux/smp.h> |
52 | #include <linux/threads.h> | |
53 | #include <linux/timer.h> | |
54 | #include <linux/rcupdate.h> | |
55 | #include <linux/cpu.h> | |
56 | #include <linux/cpuset.h> | |
57 | #include <linux/percpu.h> | |
b5aadf7f | 58 | #include <linux/proc_fs.h> |
1da177e4 | 59 | #include <linux/seq_file.h> |
969c7921 | 60 | #include <linux/stop_machine.h> |
e692ab53 | 61 | #include <linux/sysctl.h> |
1da177e4 LT |
62 | #include <linux/syscalls.h> |
63 | #include <linux/times.h> | |
8f0ab514 | 64 | #include <linux/tsacct_kern.h> |
c6fd91f0 | 65 | #include <linux/kprobes.h> |
0ff92245 | 66 | #include <linux/delayacct.h> |
dff06c15 | 67 | #include <linux/unistd.h> |
f5ff8422 | 68 | #include <linux/pagemap.h> |
8f4d37ec | 69 | #include <linux/hrtimer.h> |
30914a58 | 70 | #include <linux/tick.h> |
f00b45c1 PZ |
71 | #include <linux/debugfs.h> |
72 | #include <linux/ctype.h> | |
6cd8a4bb | 73 | #include <linux/ftrace.h> |
5a0e3ad6 | 74 | #include <linux/slab.h> |
1da177e4 | 75 | |
5517d86b | 76 | #include <asm/tlb.h> |
838225b4 | 77 | #include <asm/irq_regs.h> |
1da177e4 | 78 | |
6e0534f2 | 79 | #include "sched_cpupri.h" |
21aa9af0 | 80 | #include "workqueue_sched.h" |
6e0534f2 | 81 | |
a8d154b0 | 82 | #define CREATE_TRACE_POINTS |
ad8d75ff | 83 | #include <trace/events/sched.h> |
a8d154b0 | 84 | |
1da177e4 LT |
85 | /* |
86 | * Convert user-nice values [ -20 ... 0 ... 19 ] | |
87 | * to static priority [ MAX_RT_PRIO..MAX_PRIO-1 ], | |
88 | * and back. | |
89 | */ | |
90 | #define NICE_TO_PRIO(nice) (MAX_RT_PRIO + (nice) + 20) | |
91 | #define PRIO_TO_NICE(prio) ((prio) - MAX_RT_PRIO - 20) | |
92 | #define TASK_NICE(p) PRIO_TO_NICE((p)->static_prio) | |
93 | ||
94 | /* | |
95 | * 'User priority' is the nice value converted to something we | |
96 | * can work with better when scaling various scheduler parameters, | |
97 | * it's a [ 0 ... 39 ] range. | |
98 | */ | |
99 | #define USER_PRIO(p) ((p)-MAX_RT_PRIO) | |
100 | #define TASK_USER_PRIO(p) USER_PRIO((p)->static_prio) | |
101 | #define MAX_USER_PRIO (USER_PRIO(MAX_PRIO)) | |
102 | ||
103 | /* | |
d7876a08 | 104 | * Helpers for converting nanosecond timing to jiffy resolution |
1da177e4 | 105 | */ |
d6322faf | 106 | #define NS_TO_JIFFIES(TIME) ((unsigned long)(TIME) / (NSEC_PER_SEC / HZ)) |
1da177e4 | 107 | |
6aa645ea IM |
108 | #define NICE_0_LOAD SCHED_LOAD_SCALE |
109 | #define NICE_0_SHIFT SCHED_LOAD_SHIFT | |
110 | ||
1da177e4 LT |
111 | /* |
112 | * These are the 'tuning knobs' of the scheduler: | |
113 | * | |
a4ec24b4 | 114 | * default timeslice is 100 msecs (used only for SCHED_RR tasks). |
1da177e4 LT |
115 | * Timeslices get refilled after they expire. |
116 | */ | |
1da177e4 | 117 | #define DEF_TIMESLICE (100 * HZ / 1000) |
2dd73a4f | 118 | |
d0b27fa7 PZ |
119 | /* |
120 | * single value that denotes runtime == period, ie unlimited time. | |
121 | */ | |
122 | #define RUNTIME_INF ((u64)~0ULL) | |
123 | ||
e05606d3 IM |
124 | static inline int rt_policy(int policy) |
125 | { | |
3f33a7ce | 126 | if (unlikely(policy == SCHED_FIFO || policy == SCHED_RR)) |
e05606d3 IM |
127 | return 1; |
128 | return 0; | |
129 | } | |
130 | ||
131 | static inline int task_has_rt_policy(struct task_struct *p) | |
132 | { | |
133 | return rt_policy(p->policy); | |
134 | } | |
135 | ||
1da177e4 | 136 | /* |
6aa645ea | 137 | * This is the priority-queue data structure of the RT scheduling class: |
1da177e4 | 138 | */ |
6aa645ea IM |
139 | struct rt_prio_array { |
140 | DECLARE_BITMAP(bitmap, MAX_RT_PRIO+1); /* include 1 bit for delimiter */ | |
141 | struct list_head queue[MAX_RT_PRIO]; | |
142 | }; | |
143 | ||
d0b27fa7 | 144 | struct rt_bandwidth { |
ea736ed5 | 145 | /* nests inside the rq lock: */ |
0986b11b | 146 | raw_spinlock_t rt_runtime_lock; |
ea736ed5 IM |
147 | ktime_t rt_period; |
148 | u64 rt_runtime; | |
149 | struct hrtimer rt_period_timer; | |
d0b27fa7 PZ |
150 | }; |
151 | ||
152 | static struct rt_bandwidth def_rt_bandwidth; | |
153 | ||
154 | static int do_sched_rt_period_timer(struct rt_bandwidth *rt_b, int overrun); | |
155 | ||
156 | static enum hrtimer_restart sched_rt_period_timer(struct hrtimer *timer) | |
157 | { | |
158 | struct rt_bandwidth *rt_b = | |
159 | container_of(timer, struct rt_bandwidth, rt_period_timer); | |
160 | ktime_t now; | |
161 | int overrun; | |
162 | int idle = 0; | |
163 | ||
164 | for (;;) { | |
165 | now = hrtimer_cb_get_time(timer); | |
166 | overrun = hrtimer_forward(timer, now, rt_b->rt_period); | |
167 | ||
168 | if (!overrun) | |
169 | break; | |
170 | ||
171 | idle = do_sched_rt_period_timer(rt_b, overrun); | |
172 | } | |
173 | ||
174 | return idle ? HRTIMER_NORESTART : HRTIMER_RESTART; | |
175 | } | |
176 | ||
177 | static | |
178 | void init_rt_bandwidth(struct rt_bandwidth *rt_b, u64 period, u64 runtime) | |
179 | { | |
180 | rt_b->rt_period = ns_to_ktime(period); | |
181 | rt_b->rt_runtime = runtime; | |
182 | ||
0986b11b | 183 | raw_spin_lock_init(&rt_b->rt_runtime_lock); |
ac086bc2 | 184 | |
d0b27fa7 PZ |
185 | hrtimer_init(&rt_b->rt_period_timer, |
186 | CLOCK_MONOTONIC, HRTIMER_MODE_REL); | |
187 | rt_b->rt_period_timer.function = sched_rt_period_timer; | |
d0b27fa7 PZ |
188 | } |
189 | ||
c8bfff6d KH |
190 | static inline int rt_bandwidth_enabled(void) |
191 | { | |
192 | return sysctl_sched_rt_runtime >= 0; | |
d0b27fa7 PZ |
193 | } |
194 | ||
195 | static void start_rt_bandwidth(struct rt_bandwidth *rt_b) | |
196 | { | |
197 | ktime_t now; | |
198 | ||
cac64d00 | 199 | if (!rt_bandwidth_enabled() || rt_b->rt_runtime == RUNTIME_INF) |
d0b27fa7 PZ |
200 | return; |
201 | ||
202 | if (hrtimer_active(&rt_b->rt_period_timer)) | |
203 | return; | |
204 | ||
0986b11b | 205 | raw_spin_lock(&rt_b->rt_runtime_lock); |
d0b27fa7 | 206 | for (;;) { |
7f1e2ca9 PZ |
207 | unsigned long delta; |
208 | ktime_t soft, hard; | |
209 | ||
d0b27fa7 PZ |
210 | if (hrtimer_active(&rt_b->rt_period_timer)) |
211 | break; | |
212 | ||
213 | now = hrtimer_cb_get_time(&rt_b->rt_period_timer); | |
214 | hrtimer_forward(&rt_b->rt_period_timer, now, rt_b->rt_period); | |
7f1e2ca9 PZ |
215 | |
216 | soft = hrtimer_get_softexpires(&rt_b->rt_period_timer); | |
217 | hard = hrtimer_get_expires(&rt_b->rt_period_timer); | |
218 | delta = ktime_to_ns(ktime_sub(hard, soft)); | |
219 | __hrtimer_start_range_ns(&rt_b->rt_period_timer, soft, delta, | |
5c333864 | 220 | HRTIMER_MODE_ABS_PINNED, 0); |
d0b27fa7 | 221 | } |
0986b11b | 222 | raw_spin_unlock(&rt_b->rt_runtime_lock); |
d0b27fa7 PZ |
223 | } |
224 | ||
225 | #ifdef CONFIG_RT_GROUP_SCHED | |
226 | static void destroy_rt_bandwidth(struct rt_bandwidth *rt_b) | |
227 | { | |
228 | hrtimer_cancel(&rt_b->rt_period_timer); | |
229 | } | |
230 | #endif | |
231 | ||
712555ee HC |
232 | /* |
233 | * sched_domains_mutex serializes calls to arch_init_sched_domains, | |
234 | * detach_destroy_domains and partition_sched_domains. | |
235 | */ | |
236 | static DEFINE_MUTEX(sched_domains_mutex); | |
237 | ||
7c941438 | 238 | #ifdef CONFIG_CGROUP_SCHED |
29f59db3 | 239 | |
68318b8e SV |
240 | #include <linux/cgroup.h> |
241 | ||
29f59db3 SV |
242 | struct cfs_rq; |
243 | ||
6f505b16 PZ |
244 | static LIST_HEAD(task_groups); |
245 | ||
29f59db3 | 246 | /* task group related information */ |
4cf86d77 | 247 | struct task_group { |
68318b8e | 248 | struct cgroup_subsys_state css; |
6c415b92 | 249 | |
052f1dc7 | 250 | #ifdef CONFIG_FAIR_GROUP_SCHED |
29f59db3 SV |
251 | /* schedulable entities of this group on each cpu */ |
252 | struct sched_entity **se; | |
253 | /* runqueue "owned" by this group on each cpu */ | |
254 | struct cfs_rq **cfs_rq; | |
255 | unsigned long shares; | |
052f1dc7 PZ |
256 | #endif |
257 | ||
258 | #ifdef CONFIG_RT_GROUP_SCHED | |
259 | struct sched_rt_entity **rt_se; | |
260 | struct rt_rq **rt_rq; | |
261 | ||
d0b27fa7 | 262 | struct rt_bandwidth rt_bandwidth; |
052f1dc7 | 263 | #endif |
6b2d7700 | 264 | |
ae8393e5 | 265 | struct rcu_head rcu; |
6f505b16 | 266 | struct list_head list; |
f473aa5e PZ |
267 | |
268 | struct task_group *parent; | |
269 | struct list_head siblings; | |
270 | struct list_head children; | |
29f59db3 SV |
271 | }; |
272 | ||
eff766a6 | 273 | #define root_task_group init_task_group |
6f505b16 | 274 | |
8ed36996 | 275 | /* task_group_lock serializes add/remove of task groups and also changes to |
ec2c507f SV |
276 | * a task group's cpu shares. |
277 | */ | |
8ed36996 | 278 | static DEFINE_SPINLOCK(task_group_lock); |
ec2c507f | 279 | |
e9036b36 CG |
280 | #ifdef CONFIG_FAIR_GROUP_SCHED |
281 | ||
57310a98 PZ |
282 | #ifdef CONFIG_SMP |
283 | static int root_task_group_empty(void) | |
284 | { | |
285 | return list_empty(&root_task_group.children); | |
286 | } | |
287 | #endif | |
288 | ||
052f1dc7 | 289 | # define INIT_TASK_GROUP_LOAD NICE_0_LOAD |
052f1dc7 | 290 | |
cb4ad1ff | 291 | /* |
2e084786 LJ |
292 | * A weight of 0 or 1 can cause arithmetics problems. |
293 | * A weight of a cfs_rq is the sum of weights of which entities | |
294 | * are queued on this cfs_rq, so a weight of a entity should not be | |
295 | * too large, so as the shares value of a task group. | |
cb4ad1ff MX |
296 | * (The default weight is 1024 - so there's no practical |
297 | * limitation from this.) | |
298 | */ | |
18d95a28 | 299 | #define MIN_SHARES 2 |
2e084786 | 300 | #define MAX_SHARES (1UL << 18) |
18d95a28 | 301 | |
052f1dc7 PZ |
302 | static int init_task_group_load = INIT_TASK_GROUP_LOAD; |
303 | #endif | |
304 | ||
29f59db3 | 305 | /* Default task group. |
3a252015 | 306 | * Every task in system belong to this group at bootup. |
29f59db3 | 307 | */ |
434d53b0 | 308 | struct task_group init_task_group; |
29f59db3 | 309 | |
7c941438 | 310 | #endif /* CONFIG_CGROUP_SCHED */ |
29f59db3 | 311 | |
6aa645ea IM |
312 | /* CFS-related fields in a runqueue */ |
313 | struct cfs_rq { | |
314 | struct load_weight load; | |
315 | unsigned long nr_running; | |
316 | ||
6aa645ea | 317 | u64 exec_clock; |
e9acbff6 | 318 | u64 min_vruntime; |
6aa645ea IM |
319 | |
320 | struct rb_root tasks_timeline; | |
321 | struct rb_node *rb_leftmost; | |
4a55bd5e PZ |
322 | |
323 | struct list_head tasks; | |
324 | struct list_head *balance_iterator; | |
325 | ||
326 | /* | |
327 | * 'curr' points to currently running entity on this cfs_rq. | |
6aa645ea IM |
328 | * It is set to NULL otherwise (i.e when none are currently running). |
329 | */ | |
4793241b | 330 | struct sched_entity *curr, *next, *last; |
ddc97297 | 331 | |
5ac5c4d6 | 332 | unsigned int nr_spread_over; |
ddc97297 | 333 | |
62160e3f | 334 | #ifdef CONFIG_FAIR_GROUP_SCHED |
6aa645ea IM |
335 | struct rq *rq; /* cpu runqueue to which this cfs_rq is attached */ |
336 | ||
41a2d6cf IM |
337 | /* |
338 | * leaf cfs_rqs are those that hold tasks (lowest schedulable entity in | |
6aa645ea IM |
339 | * a hierarchy). Non-leaf lrqs hold other higher schedulable entities |
340 | * (like users, containers etc.) | |
341 | * | |
342 | * leaf_cfs_rq_list ties together list of leaf cfs_rq's in a cpu. This | |
343 | * list is used during load balance. | |
344 | */ | |
41a2d6cf IM |
345 | struct list_head leaf_cfs_rq_list; |
346 | struct task_group *tg; /* group that "owns" this runqueue */ | |
c09595f6 PZ |
347 | |
348 | #ifdef CONFIG_SMP | |
c09595f6 | 349 | /* |
c8cba857 | 350 | * the part of load.weight contributed by tasks |
c09595f6 | 351 | */ |
c8cba857 | 352 | unsigned long task_weight; |
c09595f6 | 353 | |
c8cba857 PZ |
354 | /* |
355 | * h_load = weight * f(tg) | |
356 | * | |
357 | * Where f(tg) is the recursive weight fraction assigned to | |
358 | * this group. | |
359 | */ | |
360 | unsigned long h_load; | |
c09595f6 | 361 | |
c8cba857 PZ |
362 | /* |
363 | * this cpu's part of tg->shares | |
364 | */ | |
365 | unsigned long shares; | |
f1d239f7 PZ |
366 | |
367 | /* | |
368 | * load.weight at the time we set shares | |
369 | */ | |
370 | unsigned long rq_weight; | |
c09595f6 | 371 | #endif |
6aa645ea IM |
372 | #endif |
373 | }; | |
1da177e4 | 374 | |
6aa645ea IM |
375 | /* Real-Time classes' related field in a runqueue: */ |
376 | struct rt_rq { | |
377 | struct rt_prio_array active; | |
63489e45 | 378 | unsigned long rt_nr_running; |
052f1dc7 | 379 | #if defined CONFIG_SMP || defined CONFIG_RT_GROUP_SCHED |
e864c499 GH |
380 | struct { |
381 | int curr; /* highest queued rt task prio */ | |
398a153b | 382 | #ifdef CONFIG_SMP |
e864c499 | 383 | int next; /* next highest */ |
398a153b | 384 | #endif |
e864c499 | 385 | } highest_prio; |
6f505b16 | 386 | #endif |
fa85ae24 | 387 | #ifdef CONFIG_SMP |
73fe6aae | 388 | unsigned long rt_nr_migratory; |
a1ba4d8b | 389 | unsigned long rt_nr_total; |
a22d7fc1 | 390 | int overloaded; |
917b627d | 391 | struct plist_head pushable_tasks; |
fa85ae24 | 392 | #endif |
6f505b16 | 393 | int rt_throttled; |
fa85ae24 | 394 | u64 rt_time; |
ac086bc2 | 395 | u64 rt_runtime; |
ea736ed5 | 396 | /* Nests inside the rq lock: */ |
0986b11b | 397 | raw_spinlock_t rt_runtime_lock; |
6f505b16 | 398 | |
052f1dc7 | 399 | #ifdef CONFIG_RT_GROUP_SCHED |
23b0fdfc PZ |
400 | unsigned long rt_nr_boosted; |
401 | ||
6f505b16 PZ |
402 | struct rq *rq; |
403 | struct list_head leaf_rt_rq_list; | |
404 | struct task_group *tg; | |
6f505b16 | 405 | #endif |
6aa645ea IM |
406 | }; |
407 | ||
57d885fe GH |
408 | #ifdef CONFIG_SMP |
409 | ||
410 | /* | |
411 | * We add the notion of a root-domain which will be used to define per-domain | |
0eab9146 IM |
412 | * variables. Each exclusive cpuset essentially defines an island domain by |
413 | * fully partitioning the member cpus from any other cpuset. Whenever a new | |
57d885fe GH |
414 | * exclusive cpuset is created, we also create and attach a new root-domain |
415 | * object. | |
416 | * | |
57d885fe GH |
417 | */ |
418 | struct root_domain { | |
419 | atomic_t refcount; | |
c6c4927b RR |
420 | cpumask_var_t span; |
421 | cpumask_var_t online; | |
637f5085 | 422 | |
0eab9146 | 423 | /* |
637f5085 GH |
424 | * The "RT overload" flag: it gets set if a CPU has more than |
425 | * one runnable RT task. | |
426 | */ | |
c6c4927b | 427 | cpumask_var_t rto_mask; |
0eab9146 | 428 | atomic_t rto_count; |
6e0534f2 GH |
429 | #ifdef CONFIG_SMP |
430 | struct cpupri cpupri; | |
431 | #endif | |
57d885fe GH |
432 | }; |
433 | ||
dc938520 GH |
434 | /* |
435 | * By default the system creates a single root-domain with all cpus as | |
436 | * members (mimicking the global state we have today). | |
437 | */ | |
57d885fe GH |
438 | static struct root_domain def_root_domain; |
439 | ||
440 | #endif | |
441 | ||
1da177e4 LT |
442 | /* |
443 | * This is the main, per-CPU runqueue data structure. | |
444 | * | |
445 | * Locking rule: those places that want to lock multiple runqueues | |
446 | * (such as the load balancing or the thread migration code), lock | |
447 | * acquire operations must be ordered by ascending &runqueue. | |
448 | */ | |
70b97a7f | 449 | struct rq { |
d8016491 | 450 | /* runqueue lock: */ |
05fa785c | 451 | raw_spinlock_t lock; |
1da177e4 LT |
452 | |
453 | /* | |
454 | * nr_running and cpu_load should be in the same cacheline because | |
455 | * remote CPUs use both these fields when doing load calculation. | |
456 | */ | |
457 | unsigned long nr_running; | |
6aa645ea IM |
458 | #define CPU_LOAD_IDX_MAX 5 |
459 | unsigned long cpu_load[CPU_LOAD_IDX_MAX]; | |
fdf3e95d | 460 | unsigned long last_load_update_tick; |
46cb4b7c | 461 | #ifdef CONFIG_NO_HZ |
39c0cbe2 | 462 | u64 nohz_stamp; |
83cd4fe2 | 463 | unsigned char nohz_balance_kick; |
46cb4b7c | 464 | #endif |
a64692a3 MG |
465 | unsigned int skip_clock_update; |
466 | ||
d8016491 IM |
467 | /* capture load from *all* tasks on this cpu: */ |
468 | struct load_weight load; | |
6aa645ea IM |
469 | unsigned long nr_load_updates; |
470 | u64 nr_switches; | |
471 | ||
472 | struct cfs_rq cfs; | |
6f505b16 | 473 | struct rt_rq rt; |
6f505b16 | 474 | |
6aa645ea | 475 | #ifdef CONFIG_FAIR_GROUP_SCHED |
d8016491 IM |
476 | /* list of leaf cfs_rq on this cpu: */ |
477 | struct list_head leaf_cfs_rq_list; | |
052f1dc7 PZ |
478 | #endif |
479 | #ifdef CONFIG_RT_GROUP_SCHED | |
6f505b16 | 480 | struct list_head leaf_rt_rq_list; |
1da177e4 | 481 | #endif |
1da177e4 LT |
482 | |
483 | /* | |
484 | * This is part of a global counter where only the total sum | |
485 | * over all CPUs matters. A task can increase this counter on | |
486 | * one CPU and if it got migrated afterwards it may decrease | |
487 | * it on another CPU. Always updated under the runqueue lock: | |
488 | */ | |
489 | unsigned long nr_uninterruptible; | |
490 | ||
36c8b586 | 491 | struct task_struct *curr, *idle; |
c9819f45 | 492 | unsigned long next_balance; |
1da177e4 | 493 | struct mm_struct *prev_mm; |
6aa645ea | 494 | |
3e51f33f | 495 | u64 clock; |
6aa645ea | 496 | |
1da177e4 LT |
497 | atomic_t nr_iowait; |
498 | ||
499 | #ifdef CONFIG_SMP | |
0eab9146 | 500 | struct root_domain *rd; |
1da177e4 LT |
501 | struct sched_domain *sd; |
502 | ||
e51fd5e2 PZ |
503 | unsigned long cpu_power; |
504 | ||
a0a522ce | 505 | unsigned char idle_at_tick; |
1da177e4 | 506 | /* For active balancing */ |
3f029d3c | 507 | int post_schedule; |
1da177e4 LT |
508 | int active_balance; |
509 | int push_cpu; | |
969c7921 | 510 | struct cpu_stop_work active_balance_work; |
d8016491 IM |
511 | /* cpu of this runqueue: */ |
512 | int cpu; | |
1f11eb6a | 513 | int online; |
1da177e4 | 514 | |
a8a51d5e | 515 | unsigned long avg_load_per_task; |
1da177e4 | 516 | |
e9e9250b PZ |
517 | u64 rt_avg; |
518 | u64 age_stamp; | |
1b9508f6 MG |
519 | u64 idle_stamp; |
520 | u64 avg_idle; | |
1da177e4 LT |
521 | #endif |
522 | ||
dce48a84 TG |
523 | /* calc_load related fields */ |
524 | unsigned long calc_load_update; | |
525 | long calc_load_active; | |
526 | ||
8f4d37ec | 527 | #ifdef CONFIG_SCHED_HRTICK |
31656519 PZ |
528 | #ifdef CONFIG_SMP |
529 | int hrtick_csd_pending; | |
530 | struct call_single_data hrtick_csd; | |
531 | #endif | |
8f4d37ec PZ |
532 | struct hrtimer hrtick_timer; |
533 | #endif | |
534 | ||
1da177e4 LT |
535 | #ifdef CONFIG_SCHEDSTATS |
536 | /* latency stats */ | |
537 | struct sched_info rq_sched_info; | |
9c2c4802 KC |
538 | unsigned long long rq_cpu_time; |
539 | /* could above be rq->cfs_rq.exec_clock + rq->rt_rq.rt_runtime ? */ | |
1da177e4 LT |
540 | |
541 | /* sys_sched_yield() stats */ | |
480b9434 | 542 | unsigned int yld_count; |
1da177e4 LT |
543 | |
544 | /* schedule() stats */ | |
480b9434 KC |
545 | unsigned int sched_switch; |
546 | unsigned int sched_count; | |
547 | unsigned int sched_goidle; | |
1da177e4 LT |
548 | |
549 | /* try_to_wake_up() stats */ | |
480b9434 KC |
550 | unsigned int ttwu_count; |
551 | unsigned int ttwu_local; | |
b8efb561 IM |
552 | |
553 | /* BKL stats */ | |
480b9434 | 554 | unsigned int bkl_count; |
1da177e4 LT |
555 | #endif |
556 | }; | |
557 | ||
f34e3b61 | 558 | static DEFINE_PER_CPU_SHARED_ALIGNED(struct rq, runqueues); |
1da177e4 | 559 | |
7d478721 PZ |
560 | static inline |
561 | void check_preempt_curr(struct rq *rq, struct task_struct *p, int flags) | |
dd41f596 | 562 | { |
7d478721 | 563 | rq->curr->sched_class->check_preempt_curr(rq, p, flags); |
a64692a3 MG |
564 | |
565 | /* | |
566 | * A queue event has occurred, and we're going to schedule. In | |
567 | * this case, we can save a useless back to back clock update. | |
568 | */ | |
569 | if (test_tsk_need_resched(p)) | |
570 | rq->skip_clock_update = 1; | |
dd41f596 IM |
571 | } |
572 | ||
0a2966b4 CL |
573 | static inline int cpu_of(struct rq *rq) |
574 | { | |
575 | #ifdef CONFIG_SMP | |
576 | return rq->cpu; | |
577 | #else | |
578 | return 0; | |
579 | #endif | |
580 | } | |
581 | ||
497f0ab3 | 582 | #define rcu_dereference_check_sched_domain(p) \ |
d11c563d PM |
583 | rcu_dereference_check((p), \ |
584 | rcu_read_lock_sched_held() || \ | |
585 | lockdep_is_held(&sched_domains_mutex)) | |
586 | ||
674311d5 NP |
587 | /* |
588 | * The domain tree (rq->sd) is protected by RCU's quiescent state transition. | |
1a20ff27 | 589 | * See detach_destroy_domains: synchronize_sched for details. |
674311d5 NP |
590 | * |
591 | * The domain tree of any CPU may only be accessed from within | |
592 | * preempt-disabled sections. | |
593 | */ | |
48f24c4d | 594 | #define for_each_domain(cpu, __sd) \ |
497f0ab3 | 595 | for (__sd = rcu_dereference_check_sched_domain(cpu_rq(cpu)->sd); __sd; __sd = __sd->parent) |
1da177e4 LT |
596 | |
597 | #define cpu_rq(cpu) (&per_cpu(runqueues, (cpu))) | |
598 | #define this_rq() (&__get_cpu_var(runqueues)) | |
599 | #define task_rq(p) cpu_rq(task_cpu(p)) | |
600 | #define cpu_curr(cpu) (cpu_rq(cpu)->curr) | |
54d35f29 | 601 | #define raw_rq() (&__raw_get_cpu_var(runqueues)) |
1da177e4 | 602 | |
dc61b1d6 PZ |
603 | #ifdef CONFIG_CGROUP_SCHED |
604 | ||
605 | /* | |
606 | * Return the group to which this tasks belongs. | |
607 | * | |
608 | * We use task_subsys_state_check() and extend the RCU verification | |
609 | * with lockdep_is_held(&task_rq(p)->lock) because cpu_cgroup_attach() | |
610 | * holds that lock for each task it moves into the cgroup. Therefore | |
611 | * by holding that lock, we pin the task to the current cgroup. | |
612 | */ | |
613 | static inline struct task_group *task_group(struct task_struct *p) | |
614 | { | |
615 | struct cgroup_subsys_state *css; | |
616 | ||
617 | css = task_subsys_state_check(p, cpu_cgroup_subsys_id, | |
618 | lockdep_is_held(&task_rq(p)->lock)); | |
619 | return container_of(css, struct task_group, css); | |
620 | } | |
621 | ||
622 | /* Change a task's cfs_rq and parent entity if it moves across CPUs/groups */ | |
623 | static inline void set_task_rq(struct task_struct *p, unsigned int cpu) | |
624 | { | |
625 | #ifdef CONFIG_FAIR_GROUP_SCHED | |
626 | p->se.cfs_rq = task_group(p)->cfs_rq[cpu]; | |
627 | p->se.parent = task_group(p)->se[cpu]; | |
628 | #endif | |
629 | ||
630 | #ifdef CONFIG_RT_GROUP_SCHED | |
631 | p->rt.rt_rq = task_group(p)->rt_rq[cpu]; | |
632 | p->rt.parent = task_group(p)->rt_se[cpu]; | |
633 | #endif | |
634 | } | |
635 | ||
636 | #else /* CONFIG_CGROUP_SCHED */ | |
637 | ||
638 | static inline void set_task_rq(struct task_struct *p, unsigned int cpu) { } | |
639 | static inline struct task_group *task_group(struct task_struct *p) | |
640 | { | |
641 | return NULL; | |
642 | } | |
643 | ||
644 | #endif /* CONFIG_CGROUP_SCHED */ | |
645 | ||
aa9c4c0f | 646 | inline void update_rq_clock(struct rq *rq) |
3e51f33f | 647 | { |
a64692a3 MG |
648 | if (!rq->skip_clock_update) |
649 | rq->clock = sched_clock_cpu(cpu_of(rq)); | |
3e51f33f PZ |
650 | } |
651 | ||
bf5c91ba IM |
652 | /* |
653 | * Tunables that become constants when CONFIG_SCHED_DEBUG is off: | |
654 | */ | |
655 | #ifdef CONFIG_SCHED_DEBUG | |
656 | # define const_debug __read_mostly | |
657 | #else | |
658 | # define const_debug static const | |
659 | #endif | |
660 | ||
017730c1 IM |
661 | /** |
662 | * runqueue_is_locked | |
e17b38bf | 663 | * @cpu: the processor in question. |
017730c1 IM |
664 | * |
665 | * Returns true if the current cpu runqueue is locked. | |
666 | * This interface allows printk to be called with the runqueue lock | |
667 | * held and know whether or not it is OK to wake up the klogd. | |
668 | */ | |
89f19f04 | 669 | int runqueue_is_locked(int cpu) |
017730c1 | 670 | { |
05fa785c | 671 | return raw_spin_is_locked(&cpu_rq(cpu)->lock); |
017730c1 IM |
672 | } |
673 | ||
bf5c91ba IM |
674 | /* |
675 | * Debugging: various feature bits | |
676 | */ | |
f00b45c1 PZ |
677 | |
678 | #define SCHED_FEAT(name, enabled) \ | |
679 | __SCHED_FEAT_##name , | |
680 | ||
bf5c91ba | 681 | enum { |
f00b45c1 | 682 | #include "sched_features.h" |
bf5c91ba IM |
683 | }; |
684 | ||
f00b45c1 PZ |
685 | #undef SCHED_FEAT |
686 | ||
687 | #define SCHED_FEAT(name, enabled) \ | |
688 | (1UL << __SCHED_FEAT_##name) * enabled | | |
689 | ||
bf5c91ba | 690 | const_debug unsigned int sysctl_sched_features = |
f00b45c1 PZ |
691 | #include "sched_features.h" |
692 | 0; | |
693 | ||
694 | #undef SCHED_FEAT | |
695 | ||
696 | #ifdef CONFIG_SCHED_DEBUG | |
697 | #define SCHED_FEAT(name, enabled) \ | |
698 | #name , | |
699 | ||
983ed7a6 | 700 | static __read_mostly char *sched_feat_names[] = { |
f00b45c1 PZ |
701 | #include "sched_features.h" |
702 | NULL | |
703 | }; | |
704 | ||
705 | #undef SCHED_FEAT | |
706 | ||
34f3a814 | 707 | static int sched_feat_show(struct seq_file *m, void *v) |
f00b45c1 | 708 | { |
f00b45c1 PZ |
709 | int i; |
710 | ||
711 | for (i = 0; sched_feat_names[i]; i++) { | |
34f3a814 LZ |
712 | if (!(sysctl_sched_features & (1UL << i))) |
713 | seq_puts(m, "NO_"); | |
714 | seq_printf(m, "%s ", sched_feat_names[i]); | |
f00b45c1 | 715 | } |
34f3a814 | 716 | seq_puts(m, "\n"); |
f00b45c1 | 717 | |
34f3a814 | 718 | return 0; |
f00b45c1 PZ |
719 | } |
720 | ||
721 | static ssize_t | |
722 | sched_feat_write(struct file *filp, const char __user *ubuf, | |
723 | size_t cnt, loff_t *ppos) | |
724 | { | |
725 | char buf[64]; | |
726 | char *cmp = buf; | |
727 | int neg = 0; | |
728 | int i; | |
729 | ||
730 | if (cnt > 63) | |
731 | cnt = 63; | |
732 | ||
733 | if (copy_from_user(&buf, ubuf, cnt)) | |
734 | return -EFAULT; | |
735 | ||
736 | buf[cnt] = 0; | |
737 | ||
c24b7c52 | 738 | if (strncmp(buf, "NO_", 3) == 0) { |
f00b45c1 PZ |
739 | neg = 1; |
740 | cmp += 3; | |
741 | } | |
742 | ||
743 | for (i = 0; sched_feat_names[i]; i++) { | |
744 | int len = strlen(sched_feat_names[i]); | |
745 | ||
746 | if (strncmp(cmp, sched_feat_names[i], len) == 0) { | |
747 | if (neg) | |
748 | sysctl_sched_features &= ~(1UL << i); | |
749 | else | |
750 | sysctl_sched_features |= (1UL << i); | |
751 | break; | |
752 | } | |
753 | } | |
754 | ||
755 | if (!sched_feat_names[i]) | |
756 | return -EINVAL; | |
757 | ||
42994724 | 758 | *ppos += cnt; |
f00b45c1 PZ |
759 | |
760 | return cnt; | |
761 | } | |
762 | ||
34f3a814 LZ |
763 | static int sched_feat_open(struct inode *inode, struct file *filp) |
764 | { | |
765 | return single_open(filp, sched_feat_show, NULL); | |
766 | } | |
767 | ||
828c0950 | 768 | static const struct file_operations sched_feat_fops = { |
34f3a814 LZ |
769 | .open = sched_feat_open, |
770 | .write = sched_feat_write, | |
771 | .read = seq_read, | |
772 | .llseek = seq_lseek, | |
773 | .release = single_release, | |
f00b45c1 PZ |
774 | }; |
775 | ||
776 | static __init int sched_init_debug(void) | |
777 | { | |
f00b45c1 PZ |
778 | debugfs_create_file("sched_features", 0644, NULL, NULL, |
779 | &sched_feat_fops); | |
780 | ||
781 | return 0; | |
782 | } | |
783 | late_initcall(sched_init_debug); | |
784 | ||
785 | #endif | |
786 | ||
787 | #define sched_feat(x) (sysctl_sched_features & (1UL << __SCHED_FEAT_##x)) | |
bf5c91ba | 788 | |
b82d9fdd PZ |
789 | /* |
790 | * Number of tasks to iterate in a single balance run. | |
791 | * Limited because this is done with IRQs disabled. | |
792 | */ | |
793 | const_debug unsigned int sysctl_sched_nr_migrate = 32; | |
794 | ||
2398f2c6 PZ |
795 | /* |
796 | * ratelimit for updating the group shares. | |
55cd5340 | 797 | * default: 0.25ms |
2398f2c6 | 798 | */ |
55cd5340 | 799 | unsigned int sysctl_sched_shares_ratelimit = 250000; |
0bcdcf28 | 800 | unsigned int normalized_sysctl_sched_shares_ratelimit = 250000; |
2398f2c6 | 801 | |
ffda12a1 PZ |
802 | /* |
803 | * Inject some fuzzyness into changing the per-cpu group shares | |
804 | * this avoids remote rq-locks at the expense of fairness. | |
805 | * default: 4 | |
806 | */ | |
807 | unsigned int sysctl_sched_shares_thresh = 4; | |
808 | ||
e9e9250b PZ |
809 | /* |
810 | * period over which we average the RT time consumption, measured | |
811 | * in ms. | |
812 | * | |
813 | * default: 1s | |
814 | */ | |
815 | const_debug unsigned int sysctl_sched_time_avg = MSEC_PER_SEC; | |
816 | ||
fa85ae24 | 817 | /* |
9f0c1e56 | 818 | * period over which we measure -rt task cpu usage in us. |
fa85ae24 PZ |
819 | * default: 1s |
820 | */ | |
9f0c1e56 | 821 | unsigned int sysctl_sched_rt_period = 1000000; |
fa85ae24 | 822 | |
6892b75e IM |
823 | static __read_mostly int scheduler_running; |
824 | ||
9f0c1e56 PZ |
825 | /* |
826 | * part of the period that we allow rt tasks to run in us. | |
827 | * default: 0.95s | |
828 | */ | |
829 | int sysctl_sched_rt_runtime = 950000; | |
fa85ae24 | 830 | |
d0b27fa7 PZ |
831 | static inline u64 global_rt_period(void) |
832 | { | |
833 | return (u64)sysctl_sched_rt_period * NSEC_PER_USEC; | |
834 | } | |
835 | ||
836 | static inline u64 global_rt_runtime(void) | |
837 | { | |
e26873bb | 838 | if (sysctl_sched_rt_runtime < 0) |
d0b27fa7 PZ |
839 | return RUNTIME_INF; |
840 | ||
841 | return (u64)sysctl_sched_rt_runtime * NSEC_PER_USEC; | |
842 | } | |
fa85ae24 | 843 | |
1da177e4 | 844 | #ifndef prepare_arch_switch |
4866cde0 NP |
845 | # define prepare_arch_switch(next) do { } while (0) |
846 | #endif | |
847 | #ifndef finish_arch_switch | |
848 | # define finish_arch_switch(prev) do { } while (0) | |
849 | #endif | |
850 | ||
051a1d1a DA |
851 | static inline int task_current(struct rq *rq, struct task_struct *p) |
852 | { | |
853 | return rq->curr == p; | |
854 | } | |
855 | ||
4866cde0 | 856 | #ifndef __ARCH_WANT_UNLOCKED_CTXSW |
70b97a7f | 857 | static inline int task_running(struct rq *rq, struct task_struct *p) |
4866cde0 | 858 | { |
051a1d1a | 859 | return task_current(rq, p); |
4866cde0 NP |
860 | } |
861 | ||
70b97a7f | 862 | static inline void prepare_lock_switch(struct rq *rq, struct task_struct *next) |
4866cde0 NP |
863 | { |
864 | } | |
865 | ||
70b97a7f | 866 | static inline void finish_lock_switch(struct rq *rq, struct task_struct *prev) |
4866cde0 | 867 | { |
da04c035 IM |
868 | #ifdef CONFIG_DEBUG_SPINLOCK |
869 | /* this is a valid case when another task releases the spinlock */ | |
870 | rq->lock.owner = current; | |
871 | #endif | |
8a25d5de IM |
872 | /* |
873 | * If we are tracking spinlock dependencies then we have to | |
874 | * fix up the runqueue lock - which gets 'carried over' from | |
875 | * prev into current: | |
876 | */ | |
877 | spin_acquire(&rq->lock.dep_map, 0, 0, _THIS_IP_); | |
878 | ||
05fa785c | 879 | raw_spin_unlock_irq(&rq->lock); |
4866cde0 NP |
880 | } |
881 | ||
882 | #else /* __ARCH_WANT_UNLOCKED_CTXSW */ | |
70b97a7f | 883 | static inline int task_running(struct rq *rq, struct task_struct *p) |
4866cde0 NP |
884 | { |
885 | #ifdef CONFIG_SMP | |
886 | return p->oncpu; | |
887 | #else | |
051a1d1a | 888 | return task_current(rq, p); |
4866cde0 NP |
889 | #endif |
890 | } | |
891 | ||
70b97a7f | 892 | static inline void prepare_lock_switch(struct rq *rq, struct task_struct *next) |
4866cde0 NP |
893 | { |
894 | #ifdef CONFIG_SMP | |
895 | /* | |
896 | * We can optimise this out completely for !SMP, because the | |
897 | * SMP rebalancing from interrupt is the only thing that cares | |
898 | * here. | |
899 | */ | |
900 | next->oncpu = 1; | |
901 | #endif | |
902 | #ifdef __ARCH_WANT_INTERRUPTS_ON_CTXSW | |
05fa785c | 903 | raw_spin_unlock_irq(&rq->lock); |
4866cde0 | 904 | #else |
05fa785c | 905 | raw_spin_unlock(&rq->lock); |
4866cde0 NP |
906 | #endif |
907 | } | |
908 | ||
70b97a7f | 909 | static inline void finish_lock_switch(struct rq *rq, struct task_struct *prev) |
4866cde0 NP |
910 | { |
911 | #ifdef CONFIG_SMP | |
912 | /* | |
913 | * After ->oncpu is cleared, the task can be moved to a different CPU. | |
914 | * We must ensure this doesn't happen until the switch is completely | |
915 | * finished. | |
916 | */ | |
917 | smp_wmb(); | |
918 | prev->oncpu = 0; | |
919 | #endif | |
920 | #ifndef __ARCH_WANT_INTERRUPTS_ON_CTXSW | |
921 | local_irq_enable(); | |
1da177e4 | 922 | #endif |
4866cde0 NP |
923 | } |
924 | #endif /* __ARCH_WANT_UNLOCKED_CTXSW */ | |
1da177e4 | 925 | |
0970d299 | 926 | /* |
65cc8e48 PZ |
927 | * Check whether the task is waking, we use this to synchronize ->cpus_allowed |
928 | * against ttwu(). | |
0970d299 PZ |
929 | */ |
930 | static inline int task_is_waking(struct task_struct *p) | |
931 | { | |
0017d735 | 932 | return unlikely(p->state == TASK_WAKING); |
0970d299 PZ |
933 | } |
934 | ||
b29739f9 IM |
935 | /* |
936 | * __task_rq_lock - lock the runqueue a given task resides on. | |
937 | * Must be called interrupts disabled. | |
938 | */ | |
70b97a7f | 939 | static inline struct rq *__task_rq_lock(struct task_struct *p) |
b29739f9 IM |
940 | __acquires(rq->lock) |
941 | { | |
0970d299 PZ |
942 | struct rq *rq; |
943 | ||
3a5c359a | 944 | for (;;) { |
0970d299 | 945 | rq = task_rq(p); |
05fa785c | 946 | raw_spin_lock(&rq->lock); |
65cc8e48 | 947 | if (likely(rq == task_rq(p))) |
3a5c359a | 948 | return rq; |
05fa785c | 949 | raw_spin_unlock(&rq->lock); |
b29739f9 | 950 | } |
b29739f9 IM |
951 | } |
952 | ||
1da177e4 LT |
953 | /* |
954 | * task_rq_lock - lock the runqueue a given task resides on and disable | |
41a2d6cf | 955 | * interrupts. Note the ordering: we can safely lookup the task_rq without |
1da177e4 LT |
956 | * explicitly disabling preemption. |
957 | */ | |
70b97a7f | 958 | static struct rq *task_rq_lock(struct task_struct *p, unsigned long *flags) |
1da177e4 LT |
959 | __acquires(rq->lock) |
960 | { | |
70b97a7f | 961 | struct rq *rq; |
1da177e4 | 962 | |
3a5c359a AK |
963 | for (;;) { |
964 | local_irq_save(*flags); | |
965 | rq = task_rq(p); | |
05fa785c | 966 | raw_spin_lock(&rq->lock); |
65cc8e48 | 967 | if (likely(rq == task_rq(p))) |
3a5c359a | 968 | return rq; |
05fa785c | 969 | raw_spin_unlock_irqrestore(&rq->lock, *flags); |
1da177e4 | 970 | } |
1da177e4 LT |
971 | } |
972 | ||
a9957449 | 973 | static void __task_rq_unlock(struct rq *rq) |
b29739f9 IM |
974 | __releases(rq->lock) |
975 | { | |
05fa785c | 976 | raw_spin_unlock(&rq->lock); |
b29739f9 IM |
977 | } |
978 | ||
70b97a7f | 979 | static inline void task_rq_unlock(struct rq *rq, unsigned long *flags) |
1da177e4 LT |
980 | __releases(rq->lock) |
981 | { | |
05fa785c | 982 | raw_spin_unlock_irqrestore(&rq->lock, *flags); |
1da177e4 LT |
983 | } |
984 | ||
1da177e4 | 985 | /* |
cc2a73b5 | 986 | * this_rq_lock - lock this runqueue and disable interrupts. |
1da177e4 | 987 | */ |
a9957449 | 988 | static struct rq *this_rq_lock(void) |
1da177e4 LT |
989 | __acquires(rq->lock) |
990 | { | |
70b97a7f | 991 | struct rq *rq; |
1da177e4 LT |
992 | |
993 | local_irq_disable(); | |
994 | rq = this_rq(); | |
05fa785c | 995 | raw_spin_lock(&rq->lock); |
1da177e4 LT |
996 | |
997 | return rq; | |
998 | } | |
999 | ||
8f4d37ec PZ |
1000 | #ifdef CONFIG_SCHED_HRTICK |
1001 | /* | |
1002 | * Use HR-timers to deliver accurate preemption points. | |
1003 | * | |
1004 | * Its all a bit involved since we cannot program an hrt while holding the | |
1005 | * rq->lock. So what we do is store a state in in rq->hrtick_* and ask for a | |
1006 | * reschedule event. | |
1007 | * | |
1008 | * When we get rescheduled we reprogram the hrtick_timer outside of the | |
1009 | * rq->lock. | |
1010 | */ | |
8f4d37ec PZ |
1011 | |
1012 | /* | |
1013 | * Use hrtick when: | |
1014 | * - enabled by features | |
1015 | * - hrtimer is actually high res | |
1016 | */ | |
1017 | static inline int hrtick_enabled(struct rq *rq) | |
1018 | { | |
1019 | if (!sched_feat(HRTICK)) | |
1020 | return 0; | |
ba42059f | 1021 | if (!cpu_active(cpu_of(rq))) |
b328ca18 | 1022 | return 0; |
8f4d37ec PZ |
1023 | return hrtimer_is_hres_active(&rq->hrtick_timer); |
1024 | } | |
1025 | ||
8f4d37ec PZ |
1026 | static void hrtick_clear(struct rq *rq) |
1027 | { | |
1028 | if (hrtimer_active(&rq->hrtick_timer)) | |
1029 | hrtimer_cancel(&rq->hrtick_timer); | |
1030 | } | |
1031 | ||
8f4d37ec PZ |
1032 | /* |
1033 | * High-resolution timer tick. | |
1034 | * Runs from hardirq context with interrupts disabled. | |
1035 | */ | |
1036 | static enum hrtimer_restart hrtick(struct hrtimer *timer) | |
1037 | { | |
1038 | struct rq *rq = container_of(timer, struct rq, hrtick_timer); | |
1039 | ||
1040 | WARN_ON_ONCE(cpu_of(rq) != smp_processor_id()); | |
1041 | ||
05fa785c | 1042 | raw_spin_lock(&rq->lock); |
3e51f33f | 1043 | update_rq_clock(rq); |
8f4d37ec | 1044 | rq->curr->sched_class->task_tick(rq, rq->curr, 1); |
05fa785c | 1045 | raw_spin_unlock(&rq->lock); |
8f4d37ec PZ |
1046 | |
1047 | return HRTIMER_NORESTART; | |
1048 | } | |
1049 | ||
95e904c7 | 1050 | #ifdef CONFIG_SMP |
31656519 PZ |
1051 | /* |
1052 | * called from hardirq (IPI) context | |
1053 | */ | |
1054 | static void __hrtick_start(void *arg) | |
b328ca18 | 1055 | { |
31656519 | 1056 | struct rq *rq = arg; |
b328ca18 | 1057 | |
05fa785c | 1058 | raw_spin_lock(&rq->lock); |
31656519 PZ |
1059 | hrtimer_restart(&rq->hrtick_timer); |
1060 | rq->hrtick_csd_pending = 0; | |
05fa785c | 1061 | raw_spin_unlock(&rq->lock); |
b328ca18 PZ |
1062 | } |
1063 | ||
31656519 PZ |
1064 | /* |
1065 | * Called to set the hrtick timer state. | |
1066 | * | |
1067 | * called with rq->lock held and irqs disabled | |
1068 | */ | |
1069 | static void hrtick_start(struct rq *rq, u64 delay) | |
b328ca18 | 1070 | { |
31656519 PZ |
1071 | struct hrtimer *timer = &rq->hrtick_timer; |
1072 | ktime_t time = ktime_add_ns(timer->base->get_time(), delay); | |
b328ca18 | 1073 | |
cc584b21 | 1074 | hrtimer_set_expires(timer, time); |
31656519 PZ |
1075 | |
1076 | if (rq == this_rq()) { | |
1077 | hrtimer_restart(timer); | |
1078 | } else if (!rq->hrtick_csd_pending) { | |
6e275637 | 1079 | __smp_call_function_single(cpu_of(rq), &rq->hrtick_csd, 0); |
31656519 PZ |
1080 | rq->hrtick_csd_pending = 1; |
1081 | } | |
b328ca18 PZ |
1082 | } |
1083 | ||
1084 | static int | |
1085 | hotplug_hrtick(struct notifier_block *nfb, unsigned long action, void *hcpu) | |
1086 | { | |
1087 | int cpu = (int)(long)hcpu; | |
1088 | ||
1089 | switch (action) { | |
1090 | case CPU_UP_CANCELED: | |
1091 | case CPU_UP_CANCELED_FROZEN: | |
1092 | case CPU_DOWN_PREPARE: | |
1093 | case CPU_DOWN_PREPARE_FROZEN: | |
1094 | case CPU_DEAD: | |
1095 | case CPU_DEAD_FROZEN: | |
31656519 | 1096 | hrtick_clear(cpu_rq(cpu)); |
b328ca18 PZ |
1097 | return NOTIFY_OK; |
1098 | } | |
1099 | ||
1100 | return NOTIFY_DONE; | |
1101 | } | |
1102 | ||
fa748203 | 1103 | static __init void init_hrtick(void) |
b328ca18 PZ |
1104 | { |
1105 | hotcpu_notifier(hotplug_hrtick, 0); | |
1106 | } | |
31656519 PZ |
1107 | #else |
1108 | /* | |
1109 | * Called to set the hrtick timer state. | |
1110 | * | |
1111 | * called with rq->lock held and irqs disabled | |
1112 | */ | |
1113 | static void hrtick_start(struct rq *rq, u64 delay) | |
1114 | { | |
7f1e2ca9 | 1115 | __hrtimer_start_range_ns(&rq->hrtick_timer, ns_to_ktime(delay), 0, |
5c333864 | 1116 | HRTIMER_MODE_REL_PINNED, 0); |
31656519 | 1117 | } |
b328ca18 | 1118 | |
006c75f1 | 1119 | static inline void init_hrtick(void) |
8f4d37ec | 1120 | { |
8f4d37ec | 1121 | } |
31656519 | 1122 | #endif /* CONFIG_SMP */ |
8f4d37ec | 1123 | |
31656519 | 1124 | static void init_rq_hrtick(struct rq *rq) |
8f4d37ec | 1125 | { |
31656519 PZ |
1126 | #ifdef CONFIG_SMP |
1127 | rq->hrtick_csd_pending = 0; | |
8f4d37ec | 1128 | |
31656519 PZ |
1129 | rq->hrtick_csd.flags = 0; |
1130 | rq->hrtick_csd.func = __hrtick_start; | |
1131 | rq->hrtick_csd.info = rq; | |
1132 | #endif | |
8f4d37ec | 1133 | |
31656519 PZ |
1134 | hrtimer_init(&rq->hrtick_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); |
1135 | rq->hrtick_timer.function = hrtick; | |
8f4d37ec | 1136 | } |
006c75f1 | 1137 | #else /* CONFIG_SCHED_HRTICK */ |
8f4d37ec PZ |
1138 | static inline void hrtick_clear(struct rq *rq) |
1139 | { | |
1140 | } | |
1141 | ||
8f4d37ec PZ |
1142 | static inline void init_rq_hrtick(struct rq *rq) |
1143 | { | |
1144 | } | |
1145 | ||
b328ca18 PZ |
1146 | static inline void init_hrtick(void) |
1147 | { | |
1148 | } | |
006c75f1 | 1149 | #endif /* CONFIG_SCHED_HRTICK */ |
8f4d37ec | 1150 | |
c24d20db IM |
1151 | /* |
1152 | * resched_task - mark a task 'to be rescheduled now'. | |
1153 | * | |
1154 | * On UP this means the setting of the need_resched flag, on SMP it | |
1155 | * might also involve a cross-CPU call to trigger the scheduler on | |
1156 | * the target CPU. | |
1157 | */ | |
1158 | #ifdef CONFIG_SMP | |
1159 | ||
1160 | #ifndef tsk_is_polling | |
1161 | #define tsk_is_polling(t) test_tsk_thread_flag(t, TIF_POLLING_NRFLAG) | |
1162 | #endif | |
1163 | ||
31656519 | 1164 | static void resched_task(struct task_struct *p) |
c24d20db IM |
1165 | { |
1166 | int cpu; | |
1167 | ||
05fa785c | 1168 | assert_raw_spin_locked(&task_rq(p)->lock); |
c24d20db | 1169 | |
5ed0cec0 | 1170 | if (test_tsk_need_resched(p)) |
c24d20db IM |
1171 | return; |
1172 | ||
5ed0cec0 | 1173 | set_tsk_need_resched(p); |
c24d20db IM |
1174 | |
1175 | cpu = task_cpu(p); | |
1176 | if (cpu == smp_processor_id()) | |
1177 | return; | |
1178 | ||
1179 | /* NEED_RESCHED must be visible before we test polling */ | |
1180 | smp_mb(); | |
1181 | if (!tsk_is_polling(p)) | |
1182 | smp_send_reschedule(cpu); | |
1183 | } | |
1184 | ||
1185 | static void resched_cpu(int cpu) | |
1186 | { | |
1187 | struct rq *rq = cpu_rq(cpu); | |
1188 | unsigned long flags; | |
1189 | ||
05fa785c | 1190 | if (!raw_spin_trylock_irqsave(&rq->lock, flags)) |
c24d20db IM |
1191 | return; |
1192 | resched_task(cpu_curr(cpu)); | |
05fa785c | 1193 | raw_spin_unlock_irqrestore(&rq->lock, flags); |
c24d20db | 1194 | } |
06d8308c TG |
1195 | |
1196 | #ifdef CONFIG_NO_HZ | |
83cd4fe2 VP |
1197 | /* |
1198 | * In the semi idle case, use the nearest busy cpu for migrating timers | |
1199 | * from an idle cpu. This is good for power-savings. | |
1200 | * | |
1201 | * We don't do similar optimization for completely idle system, as | |
1202 | * selecting an idle cpu will add more delays to the timers than intended | |
1203 | * (as that cpu's timer base may not be uptodate wrt jiffies etc). | |
1204 | */ | |
1205 | int get_nohz_timer_target(void) | |
1206 | { | |
1207 | int cpu = smp_processor_id(); | |
1208 | int i; | |
1209 | struct sched_domain *sd; | |
1210 | ||
1211 | for_each_domain(cpu, sd) { | |
1212 | for_each_cpu(i, sched_domain_span(sd)) | |
1213 | if (!idle_cpu(i)) | |
1214 | return i; | |
1215 | } | |
1216 | return cpu; | |
1217 | } | |
06d8308c TG |
1218 | /* |
1219 | * When add_timer_on() enqueues a timer into the timer wheel of an | |
1220 | * idle CPU then this timer might expire before the next timer event | |
1221 | * which is scheduled to wake up that CPU. In case of a completely | |
1222 | * idle system the next event might even be infinite time into the | |
1223 | * future. wake_up_idle_cpu() ensures that the CPU is woken up and | |
1224 | * leaves the inner idle loop so the newly added timer is taken into | |
1225 | * account when the CPU goes back to idle and evaluates the timer | |
1226 | * wheel for the next timer event. | |
1227 | */ | |
1228 | void wake_up_idle_cpu(int cpu) | |
1229 | { | |
1230 | struct rq *rq = cpu_rq(cpu); | |
1231 | ||
1232 | if (cpu == smp_processor_id()) | |
1233 | return; | |
1234 | ||
1235 | /* | |
1236 | * This is safe, as this function is called with the timer | |
1237 | * wheel base lock of (cpu) held. When the CPU is on the way | |
1238 | * to idle and has not yet set rq->curr to idle then it will | |
1239 | * be serialized on the timer wheel base lock and take the new | |
1240 | * timer into account automatically. | |
1241 | */ | |
1242 | if (rq->curr != rq->idle) | |
1243 | return; | |
1244 | ||
1245 | /* | |
1246 | * We can set TIF_RESCHED on the idle task of the other CPU | |
1247 | * lockless. The worst case is that the other CPU runs the | |
1248 | * idle task through an additional NOOP schedule() | |
1249 | */ | |
5ed0cec0 | 1250 | set_tsk_need_resched(rq->idle); |
06d8308c TG |
1251 | |
1252 | /* NEED_RESCHED must be visible before we test polling */ | |
1253 | smp_mb(); | |
1254 | if (!tsk_is_polling(rq->idle)) | |
1255 | smp_send_reschedule(cpu); | |
1256 | } | |
39c0cbe2 | 1257 | |
6d6bc0ad | 1258 | #endif /* CONFIG_NO_HZ */ |
06d8308c | 1259 | |
e9e9250b PZ |
1260 | static u64 sched_avg_period(void) |
1261 | { | |
1262 | return (u64)sysctl_sched_time_avg * NSEC_PER_MSEC / 2; | |
1263 | } | |
1264 | ||
1265 | static void sched_avg_update(struct rq *rq) | |
1266 | { | |
1267 | s64 period = sched_avg_period(); | |
1268 | ||
1269 | while ((s64)(rq->clock - rq->age_stamp) > period) { | |
0d98bb26 WD |
1270 | /* |
1271 | * Inline assembly required to prevent the compiler | |
1272 | * optimising this loop into a divmod call. | |
1273 | * See __iter_div_u64_rem() for another example of this. | |
1274 | */ | |
1275 | asm("" : "+rm" (rq->age_stamp)); | |
e9e9250b PZ |
1276 | rq->age_stamp += period; |
1277 | rq->rt_avg /= 2; | |
1278 | } | |
1279 | } | |
1280 | ||
1281 | static void sched_rt_avg_update(struct rq *rq, u64 rt_delta) | |
1282 | { | |
1283 | rq->rt_avg += rt_delta; | |
1284 | sched_avg_update(rq); | |
1285 | } | |
1286 | ||
6d6bc0ad | 1287 | #else /* !CONFIG_SMP */ |
31656519 | 1288 | static void resched_task(struct task_struct *p) |
c24d20db | 1289 | { |
05fa785c | 1290 | assert_raw_spin_locked(&task_rq(p)->lock); |
31656519 | 1291 | set_tsk_need_resched(p); |
c24d20db | 1292 | } |
e9e9250b PZ |
1293 | |
1294 | static void sched_rt_avg_update(struct rq *rq, u64 rt_delta) | |
1295 | { | |
1296 | } | |
6d6bc0ad | 1297 | #endif /* CONFIG_SMP */ |
c24d20db | 1298 | |
45bf76df IM |
1299 | #if BITS_PER_LONG == 32 |
1300 | # define WMULT_CONST (~0UL) | |
1301 | #else | |
1302 | # define WMULT_CONST (1UL << 32) | |
1303 | #endif | |
1304 | ||
1305 | #define WMULT_SHIFT 32 | |
1306 | ||
194081eb IM |
1307 | /* |
1308 | * Shift right and round: | |
1309 | */ | |
cf2ab469 | 1310 | #define SRR(x, y) (((x) + (1UL << ((y) - 1))) >> (y)) |
194081eb | 1311 | |
a7be37ac PZ |
1312 | /* |
1313 | * delta *= weight / lw | |
1314 | */ | |
cb1c4fc9 | 1315 | static unsigned long |
45bf76df IM |
1316 | calc_delta_mine(unsigned long delta_exec, unsigned long weight, |
1317 | struct load_weight *lw) | |
1318 | { | |
1319 | u64 tmp; | |
1320 | ||
7a232e03 LJ |
1321 | if (!lw->inv_weight) { |
1322 | if (BITS_PER_LONG > 32 && unlikely(lw->weight >= WMULT_CONST)) | |
1323 | lw->inv_weight = 1; | |
1324 | else | |
1325 | lw->inv_weight = 1 + (WMULT_CONST-lw->weight/2) | |
1326 | / (lw->weight+1); | |
1327 | } | |
45bf76df IM |
1328 | |
1329 | tmp = (u64)delta_exec * weight; | |
1330 | /* | |
1331 | * Check whether we'd overflow the 64-bit multiplication: | |
1332 | */ | |
194081eb | 1333 | if (unlikely(tmp > WMULT_CONST)) |
cf2ab469 | 1334 | tmp = SRR(SRR(tmp, WMULT_SHIFT/2) * lw->inv_weight, |
194081eb IM |
1335 | WMULT_SHIFT/2); |
1336 | else | |
cf2ab469 | 1337 | tmp = SRR(tmp * lw->inv_weight, WMULT_SHIFT); |
45bf76df | 1338 | |
ecf691da | 1339 | return (unsigned long)min(tmp, (u64)(unsigned long)LONG_MAX); |
45bf76df IM |
1340 | } |
1341 | ||
1091985b | 1342 | static inline void update_load_add(struct load_weight *lw, unsigned long inc) |
45bf76df IM |
1343 | { |
1344 | lw->weight += inc; | |
e89996ae | 1345 | lw->inv_weight = 0; |
45bf76df IM |
1346 | } |
1347 | ||
1091985b | 1348 | static inline void update_load_sub(struct load_weight *lw, unsigned long dec) |
45bf76df IM |
1349 | { |
1350 | lw->weight -= dec; | |
e89996ae | 1351 | lw->inv_weight = 0; |
45bf76df IM |
1352 | } |
1353 | ||
2dd73a4f PW |
1354 | /* |
1355 | * To aid in avoiding the subversion of "niceness" due to uneven distribution | |
1356 | * of tasks with abnormal "nice" values across CPUs the contribution that | |
1357 | * each task makes to its run queue's load is weighted according to its | |
41a2d6cf | 1358 | * scheduling class and "nice" value. For SCHED_NORMAL tasks this is just a |
2dd73a4f PW |
1359 | * scaled version of the new time slice allocation that they receive on time |
1360 | * slice expiry etc. | |
1361 | */ | |
1362 | ||
cce7ade8 PZ |
1363 | #define WEIGHT_IDLEPRIO 3 |
1364 | #define WMULT_IDLEPRIO 1431655765 | |
dd41f596 IM |
1365 | |
1366 | /* | |
1367 | * Nice levels are multiplicative, with a gentle 10% change for every | |
1368 | * nice level changed. I.e. when a CPU-bound task goes from nice 0 to | |
1369 | * nice 1, it will get ~10% less CPU time than another CPU-bound task | |
1370 | * that remained on nice 0. | |
1371 | * | |
1372 | * The "10% effect" is relative and cumulative: from _any_ nice level, | |
1373 | * if you go up 1 level, it's -10% CPU usage, if you go down 1 level | |
f9153ee6 IM |
1374 | * it's +10% CPU usage. (to achieve that we use a multiplier of 1.25. |
1375 | * If a task goes up by ~10% and another task goes down by ~10% then | |
1376 | * the relative distance between them is ~25%.) | |
dd41f596 IM |
1377 | */ |
1378 | static const int prio_to_weight[40] = { | |
254753dc IM |
1379 | /* -20 */ 88761, 71755, 56483, 46273, 36291, |
1380 | /* -15 */ 29154, 23254, 18705, 14949, 11916, | |
1381 | /* -10 */ 9548, 7620, 6100, 4904, 3906, | |
1382 | /* -5 */ 3121, 2501, 1991, 1586, 1277, | |
1383 | /* 0 */ 1024, 820, 655, 526, 423, | |
1384 | /* 5 */ 335, 272, 215, 172, 137, | |
1385 | /* 10 */ 110, 87, 70, 56, 45, | |
1386 | /* 15 */ 36, 29, 23, 18, 15, | |
dd41f596 IM |
1387 | }; |
1388 | ||
5714d2de IM |
1389 | /* |
1390 | * Inverse (2^32/x) values of the prio_to_weight[] array, precalculated. | |
1391 | * | |
1392 | * In cases where the weight does not change often, we can use the | |
1393 | * precalculated inverse to speed up arithmetics by turning divisions | |
1394 | * into multiplications: | |
1395 | */ | |
dd41f596 | 1396 | static const u32 prio_to_wmult[40] = { |
254753dc IM |
1397 | /* -20 */ 48388, 59856, 76040, 92818, 118348, |
1398 | /* -15 */ 147320, 184698, 229616, 287308, 360437, | |
1399 | /* -10 */ 449829, 563644, 704093, 875809, 1099582, | |
1400 | /* -5 */ 1376151, 1717300, 2157191, 2708050, 3363326, | |
1401 | /* 0 */ 4194304, 5237765, 6557202, 8165337, 10153587, | |
1402 | /* 5 */ 12820798, 15790321, 19976592, 24970740, 31350126, | |
1403 | /* 10 */ 39045157, 49367440, 61356676, 76695844, 95443717, | |
1404 | /* 15 */ 119304647, 148102320, 186737708, 238609294, 286331153, | |
dd41f596 | 1405 | }; |
2dd73a4f | 1406 | |
ef12fefa BR |
1407 | /* Time spent by the tasks of the cpu accounting group executing in ... */ |
1408 | enum cpuacct_stat_index { | |
1409 | CPUACCT_STAT_USER, /* ... user mode */ | |
1410 | CPUACCT_STAT_SYSTEM, /* ... kernel mode */ | |
1411 | ||
1412 | CPUACCT_STAT_NSTATS, | |
1413 | }; | |
1414 | ||
d842de87 SV |
1415 | #ifdef CONFIG_CGROUP_CPUACCT |
1416 | static void cpuacct_charge(struct task_struct *tsk, u64 cputime); | |
ef12fefa BR |
1417 | static void cpuacct_update_stats(struct task_struct *tsk, |
1418 | enum cpuacct_stat_index idx, cputime_t val); | |
d842de87 SV |
1419 | #else |
1420 | static inline void cpuacct_charge(struct task_struct *tsk, u64 cputime) {} | |
ef12fefa BR |
1421 | static inline void cpuacct_update_stats(struct task_struct *tsk, |
1422 | enum cpuacct_stat_index idx, cputime_t val) {} | |
d842de87 SV |
1423 | #endif |
1424 | ||
18d95a28 PZ |
1425 | static inline void inc_cpu_load(struct rq *rq, unsigned long load) |
1426 | { | |
1427 | update_load_add(&rq->load, load); | |
1428 | } | |
1429 | ||
1430 | static inline void dec_cpu_load(struct rq *rq, unsigned long load) | |
1431 | { | |
1432 | update_load_sub(&rq->load, load); | |
1433 | } | |
1434 | ||
7940ca36 | 1435 | #if (defined(CONFIG_SMP) && defined(CONFIG_FAIR_GROUP_SCHED)) || defined(CONFIG_RT_GROUP_SCHED) |
eb755805 | 1436 | typedef int (*tg_visitor)(struct task_group *, void *); |
c09595f6 PZ |
1437 | |
1438 | /* | |
1439 | * Iterate the full tree, calling @down when first entering a node and @up when | |
1440 | * leaving it for the final time. | |
1441 | */ | |
eb755805 | 1442 | static int walk_tg_tree(tg_visitor down, tg_visitor up, void *data) |
c09595f6 PZ |
1443 | { |
1444 | struct task_group *parent, *child; | |
eb755805 | 1445 | int ret; |
c09595f6 PZ |
1446 | |
1447 | rcu_read_lock(); | |
1448 | parent = &root_task_group; | |
1449 | down: | |
eb755805 PZ |
1450 | ret = (*down)(parent, data); |
1451 | if (ret) | |
1452 | goto out_unlock; | |
c09595f6 PZ |
1453 | list_for_each_entry_rcu(child, &parent->children, siblings) { |
1454 | parent = child; | |
1455 | goto down; | |
1456 | ||
1457 | up: | |
1458 | continue; | |
1459 | } | |
eb755805 PZ |
1460 | ret = (*up)(parent, data); |
1461 | if (ret) | |
1462 | goto out_unlock; | |
c09595f6 PZ |
1463 | |
1464 | child = parent; | |
1465 | parent = parent->parent; | |
1466 | if (parent) | |
1467 | goto up; | |
eb755805 | 1468 | out_unlock: |
c09595f6 | 1469 | rcu_read_unlock(); |
eb755805 PZ |
1470 | |
1471 | return ret; | |
c09595f6 PZ |
1472 | } |
1473 | ||
eb755805 PZ |
1474 | static int tg_nop(struct task_group *tg, void *data) |
1475 | { | |
1476 | return 0; | |
c09595f6 | 1477 | } |
eb755805 PZ |
1478 | #endif |
1479 | ||
1480 | #ifdef CONFIG_SMP | |
f5f08f39 PZ |
1481 | /* Used instead of source_load when we know the type == 0 */ |
1482 | static unsigned long weighted_cpuload(const int cpu) | |
1483 | { | |
1484 | return cpu_rq(cpu)->load.weight; | |
1485 | } | |
1486 | ||
1487 | /* | |
1488 | * Return a low guess at the load of a migration-source cpu weighted | |
1489 | * according to the scheduling class and "nice" value. | |
1490 | * | |
1491 | * We want to under-estimate the load of migration sources, to | |
1492 | * balance conservatively. | |
1493 | */ | |
1494 | static unsigned long source_load(int cpu, int type) | |
1495 | { | |
1496 | struct rq *rq = cpu_rq(cpu); | |
1497 | unsigned long total = weighted_cpuload(cpu); | |
1498 | ||
1499 | if (type == 0 || !sched_feat(LB_BIAS)) | |
1500 | return total; | |
1501 | ||
1502 | return min(rq->cpu_load[type-1], total); | |
1503 | } | |
1504 | ||
1505 | /* | |
1506 | * Return a high guess at the load of a migration-target cpu weighted | |
1507 | * according to the scheduling class and "nice" value. | |
1508 | */ | |
1509 | static unsigned long target_load(int cpu, int type) | |
1510 | { | |
1511 | struct rq *rq = cpu_rq(cpu); | |
1512 | unsigned long total = weighted_cpuload(cpu); | |
1513 | ||
1514 | if (type == 0 || !sched_feat(LB_BIAS)) | |
1515 | return total; | |
1516 | ||
1517 | return max(rq->cpu_load[type-1], total); | |
1518 | } | |
1519 | ||
ae154be1 PZ |
1520 | static unsigned long power_of(int cpu) |
1521 | { | |
e51fd5e2 | 1522 | return cpu_rq(cpu)->cpu_power; |
ae154be1 PZ |
1523 | } |
1524 | ||
eb755805 PZ |
1525 | static int task_hot(struct task_struct *p, u64 now, struct sched_domain *sd); |
1526 | ||
1527 | static unsigned long cpu_avg_load_per_task(int cpu) | |
1528 | { | |
1529 | struct rq *rq = cpu_rq(cpu); | |
af6d596f | 1530 | unsigned long nr_running = ACCESS_ONCE(rq->nr_running); |
eb755805 | 1531 | |
4cd42620 SR |
1532 | if (nr_running) |
1533 | rq->avg_load_per_task = rq->load.weight / nr_running; | |
a2d47777 BS |
1534 | else |
1535 | rq->avg_load_per_task = 0; | |
eb755805 PZ |
1536 | |
1537 | return rq->avg_load_per_task; | |
1538 | } | |
1539 | ||
1540 | #ifdef CONFIG_FAIR_GROUP_SCHED | |
c09595f6 | 1541 | |
43cf38eb | 1542 | static __read_mostly unsigned long __percpu *update_shares_data; |
34d76c41 | 1543 | |
c09595f6 PZ |
1544 | static void __set_se_shares(struct sched_entity *se, unsigned long shares); |
1545 | ||
1546 | /* | |
1547 | * Calculate and set the cpu's group shares. | |
1548 | */ | |
34d76c41 PZ |
1549 | static void update_group_shares_cpu(struct task_group *tg, int cpu, |
1550 | unsigned long sd_shares, | |
1551 | unsigned long sd_rq_weight, | |
4a6cc4bd | 1552 | unsigned long *usd_rq_weight) |
18d95a28 | 1553 | { |
34d76c41 | 1554 | unsigned long shares, rq_weight; |
a5004278 | 1555 | int boost = 0; |
c09595f6 | 1556 | |
4a6cc4bd | 1557 | rq_weight = usd_rq_weight[cpu]; |
a5004278 PZ |
1558 | if (!rq_weight) { |
1559 | boost = 1; | |
1560 | rq_weight = NICE_0_LOAD; | |
1561 | } | |
c8cba857 | 1562 | |
c09595f6 | 1563 | /* |
a8af7246 PZ |
1564 | * \Sum_j shares_j * rq_weight_i |
1565 | * shares_i = ----------------------------- | |
1566 | * \Sum_j rq_weight_j | |
c09595f6 | 1567 | */ |
ec4e0e2f | 1568 | shares = (sd_shares * rq_weight) / sd_rq_weight; |
ffda12a1 | 1569 | shares = clamp_t(unsigned long, shares, MIN_SHARES, MAX_SHARES); |
c09595f6 | 1570 | |
ffda12a1 PZ |
1571 | if (abs(shares - tg->se[cpu]->load.weight) > |
1572 | sysctl_sched_shares_thresh) { | |
1573 | struct rq *rq = cpu_rq(cpu); | |
1574 | unsigned long flags; | |
c09595f6 | 1575 | |
05fa785c | 1576 | raw_spin_lock_irqsave(&rq->lock, flags); |
34d76c41 | 1577 | tg->cfs_rq[cpu]->rq_weight = boost ? 0 : rq_weight; |
a5004278 | 1578 | tg->cfs_rq[cpu]->shares = boost ? 0 : shares; |
ffda12a1 | 1579 | __set_se_shares(tg->se[cpu], shares); |
05fa785c | 1580 | raw_spin_unlock_irqrestore(&rq->lock, flags); |
ffda12a1 | 1581 | } |
18d95a28 | 1582 | } |
c09595f6 PZ |
1583 | |
1584 | /* | |
c8cba857 PZ |
1585 | * Re-compute the task group their per cpu shares over the given domain. |
1586 | * This needs to be done in a bottom-up fashion because the rq weight of a | |
1587 | * parent group depends on the shares of its child groups. | |
c09595f6 | 1588 | */ |
eb755805 | 1589 | static int tg_shares_up(struct task_group *tg, void *data) |
c09595f6 | 1590 | { |
cd8ad40d | 1591 | unsigned long weight, rq_weight = 0, sum_weight = 0, shares = 0; |
4a6cc4bd | 1592 | unsigned long *usd_rq_weight; |
eb755805 | 1593 | struct sched_domain *sd = data; |
34d76c41 | 1594 | unsigned long flags; |
c8cba857 | 1595 | int i; |
c09595f6 | 1596 | |
34d76c41 PZ |
1597 | if (!tg->se[0]) |
1598 | return 0; | |
1599 | ||
1600 | local_irq_save(flags); | |
4a6cc4bd | 1601 | usd_rq_weight = per_cpu_ptr(update_shares_data, smp_processor_id()); |
34d76c41 | 1602 | |
758b2cdc | 1603 | for_each_cpu(i, sched_domain_span(sd)) { |
34d76c41 | 1604 | weight = tg->cfs_rq[i]->load.weight; |
4a6cc4bd | 1605 | usd_rq_weight[i] = weight; |
34d76c41 | 1606 | |
cd8ad40d | 1607 | rq_weight += weight; |
ec4e0e2f KC |
1608 | /* |
1609 | * If there are currently no tasks on the cpu pretend there | |
1610 | * is one of average load so that when a new task gets to | |
1611 | * run here it will not get delayed by group starvation. | |
1612 | */ | |
ec4e0e2f KC |
1613 | if (!weight) |
1614 | weight = NICE_0_LOAD; | |
1615 | ||
cd8ad40d | 1616 | sum_weight += weight; |
c8cba857 | 1617 | shares += tg->cfs_rq[i]->shares; |
c09595f6 | 1618 | } |
c09595f6 | 1619 | |
cd8ad40d PZ |
1620 | if (!rq_weight) |
1621 | rq_weight = sum_weight; | |
1622 | ||
c8cba857 PZ |
1623 | if ((!shares && rq_weight) || shares > tg->shares) |
1624 | shares = tg->shares; | |
1625 | ||
1626 | if (!sd->parent || !(sd->parent->flags & SD_LOAD_BALANCE)) | |
1627 | shares = tg->shares; | |
c09595f6 | 1628 | |
758b2cdc | 1629 | for_each_cpu(i, sched_domain_span(sd)) |
4a6cc4bd | 1630 | update_group_shares_cpu(tg, i, shares, rq_weight, usd_rq_weight); |
34d76c41 PZ |
1631 | |
1632 | local_irq_restore(flags); | |
eb755805 PZ |
1633 | |
1634 | return 0; | |
c09595f6 PZ |
1635 | } |
1636 | ||
1637 | /* | |
c8cba857 PZ |
1638 | * Compute the cpu's hierarchical load factor for each task group. |
1639 | * This needs to be done in a top-down fashion because the load of a child | |
1640 | * group is a fraction of its parents load. | |
c09595f6 | 1641 | */ |
eb755805 | 1642 | static int tg_load_down(struct task_group *tg, void *data) |
c09595f6 | 1643 | { |
c8cba857 | 1644 | unsigned long load; |
eb755805 | 1645 | long cpu = (long)data; |
c09595f6 | 1646 | |
c8cba857 PZ |
1647 | if (!tg->parent) { |
1648 | load = cpu_rq(cpu)->load.weight; | |
1649 | } else { | |
1650 | load = tg->parent->cfs_rq[cpu]->h_load; | |
1651 | load *= tg->cfs_rq[cpu]->shares; | |
1652 | load /= tg->parent->cfs_rq[cpu]->load.weight + 1; | |
1653 | } | |
c09595f6 | 1654 | |
c8cba857 | 1655 | tg->cfs_rq[cpu]->h_load = load; |
c09595f6 | 1656 | |
eb755805 | 1657 | return 0; |
c09595f6 PZ |
1658 | } |
1659 | ||
c8cba857 | 1660 | static void update_shares(struct sched_domain *sd) |
4d8d595d | 1661 | { |
e7097159 PZ |
1662 | s64 elapsed; |
1663 | u64 now; | |
1664 | ||
1665 | if (root_task_group_empty()) | |
1666 | return; | |
1667 | ||
c676329a | 1668 | now = local_clock(); |
e7097159 | 1669 | elapsed = now - sd->last_update; |
2398f2c6 PZ |
1670 | |
1671 | if (elapsed >= (s64)(u64)sysctl_sched_shares_ratelimit) { | |
1672 | sd->last_update = now; | |
eb755805 | 1673 | walk_tg_tree(tg_nop, tg_shares_up, sd); |
2398f2c6 | 1674 | } |
4d8d595d PZ |
1675 | } |
1676 | ||
eb755805 | 1677 | static void update_h_load(long cpu) |
c09595f6 | 1678 | { |
eb755805 | 1679 | walk_tg_tree(tg_load_down, tg_nop, (void *)cpu); |
c09595f6 PZ |
1680 | } |
1681 | ||
c09595f6 PZ |
1682 | #else |
1683 | ||
c8cba857 | 1684 | static inline void update_shares(struct sched_domain *sd) |
4d8d595d PZ |
1685 | { |
1686 | } | |
1687 | ||
18d95a28 PZ |
1688 | #endif |
1689 | ||
8f45e2b5 GH |
1690 | #ifdef CONFIG_PREEMPT |
1691 | ||
b78bb868 PZ |
1692 | static void double_rq_lock(struct rq *rq1, struct rq *rq2); |
1693 | ||
70574a99 | 1694 | /* |
8f45e2b5 GH |
1695 | * fair double_lock_balance: Safely acquires both rq->locks in a fair |
1696 | * way at the expense of forcing extra atomic operations in all | |
1697 | * invocations. This assures that the double_lock is acquired using the | |
1698 | * same underlying policy as the spinlock_t on this architecture, which | |
1699 | * reduces latency compared to the unfair variant below. However, it | |
1700 | * also adds more overhead and therefore may reduce throughput. | |
70574a99 | 1701 | */ |
8f45e2b5 GH |
1702 | static inline int _double_lock_balance(struct rq *this_rq, struct rq *busiest) |
1703 | __releases(this_rq->lock) | |
1704 | __acquires(busiest->lock) | |
1705 | __acquires(this_rq->lock) | |
1706 | { | |
05fa785c | 1707 | raw_spin_unlock(&this_rq->lock); |
8f45e2b5 GH |
1708 | double_rq_lock(this_rq, busiest); |
1709 | ||
1710 | return 1; | |
1711 | } | |
1712 | ||
1713 | #else | |
1714 | /* | |
1715 | * Unfair double_lock_balance: Optimizes throughput at the expense of | |
1716 | * latency by eliminating extra atomic operations when the locks are | |
1717 | * already in proper order on entry. This favors lower cpu-ids and will | |
1718 | * grant the double lock to lower cpus over higher ids under contention, | |
1719 | * regardless of entry order into the function. | |
1720 | */ | |
1721 | static int _double_lock_balance(struct rq *this_rq, struct rq *busiest) | |
70574a99 AD |
1722 | __releases(this_rq->lock) |
1723 | __acquires(busiest->lock) | |
1724 | __acquires(this_rq->lock) | |
1725 | { | |
1726 | int ret = 0; | |
1727 | ||
05fa785c | 1728 | if (unlikely(!raw_spin_trylock(&busiest->lock))) { |
70574a99 | 1729 | if (busiest < this_rq) { |
05fa785c TG |
1730 | raw_spin_unlock(&this_rq->lock); |
1731 | raw_spin_lock(&busiest->lock); | |
1732 | raw_spin_lock_nested(&this_rq->lock, | |
1733 | SINGLE_DEPTH_NESTING); | |
70574a99 AD |
1734 | ret = 1; |
1735 | } else | |
05fa785c TG |
1736 | raw_spin_lock_nested(&busiest->lock, |
1737 | SINGLE_DEPTH_NESTING); | |
70574a99 AD |
1738 | } |
1739 | return ret; | |
1740 | } | |
1741 | ||
8f45e2b5 GH |
1742 | #endif /* CONFIG_PREEMPT */ |
1743 | ||
1744 | /* | |
1745 | * double_lock_balance - lock the busiest runqueue, this_rq is locked already. | |
1746 | */ | |
1747 | static int double_lock_balance(struct rq *this_rq, struct rq *busiest) | |
1748 | { | |
1749 | if (unlikely(!irqs_disabled())) { | |
1750 | /* printk() doesn't work good under rq->lock */ | |
05fa785c | 1751 | raw_spin_unlock(&this_rq->lock); |
8f45e2b5 GH |
1752 | BUG_ON(1); |
1753 | } | |
1754 | ||
1755 | return _double_lock_balance(this_rq, busiest); | |
1756 | } | |
1757 | ||
70574a99 AD |
1758 | static inline void double_unlock_balance(struct rq *this_rq, struct rq *busiest) |
1759 | __releases(busiest->lock) | |
1760 | { | |
05fa785c | 1761 | raw_spin_unlock(&busiest->lock); |
70574a99 AD |
1762 | lock_set_subclass(&this_rq->lock.dep_map, 0, _RET_IP_); |
1763 | } | |
1e3c88bd PZ |
1764 | |
1765 | /* | |
1766 | * double_rq_lock - safely lock two runqueues | |
1767 | * | |
1768 | * Note this does not disable interrupts like task_rq_lock, | |
1769 | * you need to do so manually before calling. | |
1770 | */ | |
1771 | static void double_rq_lock(struct rq *rq1, struct rq *rq2) | |
1772 | __acquires(rq1->lock) | |
1773 | __acquires(rq2->lock) | |
1774 | { | |
1775 | BUG_ON(!irqs_disabled()); | |
1776 | if (rq1 == rq2) { | |
1777 | raw_spin_lock(&rq1->lock); | |
1778 | __acquire(rq2->lock); /* Fake it out ;) */ | |
1779 | } else { | |
1780 | if (rq1 < rq2) { | |
1781 | raw_spin_lock(&rq1->lock); | |
1782 | raw_spin_lock_nested(&rq2->lock, SINGLE_DEPTH_NESTING); | |
1783 | } else { | |
1784 | raw_spin_lock(&rq2->lock); | |
1785 | raw_spin_lock_nested(&rq1->lock, SINGLE_DEPTH_NESTING); | |
1786 | } | |
1787 | } | |
1e3c88bd PZ |
1788 | } |
1789 | ||
1790 | /* | |
1791 | * double_rq_unlock - safely unlock two runqueues | |
1792 | * | |
1793 | * Note this does not restore interrupts like task_rq_unlock, | |
1794 | * you need to do so manually after calling. | |
1795 | */ | |
1796 | static void double_rq_unlock(struct rq *rq1, struct rq *rq2) | |
1797 | __releases(rq1->lock) | |
1798 | __releases(rq2->lock) | |
1799 | { | |
1800 | raw_spin_unlock(&rq1->lock); | |
1801 | if (rq1 != rq2) | |
1802 | raw_spin_unlock(&rq2->lock); | |
1803 | else | |
1804 | __release(rq2->lock); | |
1805 | } | |
1806 | ||
18d95a28 PZ |
1807 | #endif |
1808 | ||
30432094 | 1809 | #ifdef CONFIG_FAIR_GROUP_SCHED |
34e83e85 IM |
1810 | static void cfs_rq_set_shares(struct cfs_rq *cfs_rq, unsigned long shares) |
1811 | { | |
30432094 | 1812 | #ifdef CONFIG_SMP |
34e83e85 IM |
1813 | cfs_rq->shares = shares; |
1814 | #endif | |
1815 | } | |
30432094 | 1816 | #endif |
e7693a36 | 1817 | |
74f5187a | 1818 | static void calc_load_account_idle(struct rq *this_rq); |
0bcdcf28 | 1819 | static void update_sysctl(void); |
acb4a848 | 1820 | static int get_update_sysctl_factor(void); |
fdf3e95d | 1821 | static void update_cpu_load(struct rq *this_rq); |
dce48a84 | 1822 | |
cd29fe6f PZ |
1823 | static inline void __set_task_cpu(struct task_struct *p, unsigned int cpu) |
1824 | { | |
1825 | set_task_rq(p, cpu); | |
1826 | #ifdef CONFIG_SMP | |
1827 | /* | |
1828 | * After ->cpu is set up to a new value, task_rq_lock(p, ...) can be | |
1829 | * successfuly executed on another CPU. We must ensure that updates of | |
1830 | * per-task data have been completed by this moment. | |
1831 | */ | |
1832 | smp_wmb(); | |
1833 | task_thread_info(p)->cpu = cpu; | |
1834 | #endif | |
1835 | } | |
dce48a84 | 1836 | |
1e3c88bd | 1837 | static const struct sched_class rt_sched_class; |
dd41f596 IM |
1838 | |
1839 | #define sched_class_highest (&rt_sched_class) | |
1f11eb6a GH |
1840 | #define for_each_class(class) \ |
1841 | for (class = sched_class_highest; class; class = class->next) | |
dd41f596 | 1842 | |
1e3c88bd PZ |
1843 | #include "sched_stats.h" |
1844 | ||
c09595f6 | 1845 | static void inc_nr_running(struct rq *rq) |
9c217245 IM |
1846 | { |
1847 | rq->nr_running++; | |
9c217245 IM |
1848 | } |
1849 | ||
c09595f6 | 1850 | static void dec_nr_running(struct rq *rq) |
9c217245 IM |
1851 | { |
1852 | rq->nr_running--; | |
9c217245 IM |
1853 | } |
1854 | ||
45bf76df IM |
1855 | static void set_load_weight(struct task_struct *p) |
1856 | { | |
1857 | if (task_has_rt_policy(p)) { | |
e51fd5e2 PZ |
1858 | p->se.load.weight = 0; |
1859 | p->se.load.inv_weight = WMULT_CONST; | |
dd41f596 IM |
1860 | return; |
1861 | } | |
45bf76df | 1862 | |
dd41f596 IM |
1863 | /* |
1864 | * SCHED_IDLE tasks get minimal weight: | |
1865 | */ | |
1866 | if (p->policy == SCHED_IDLE) { | |
1867 | p->se.load.weight = WEIGHT_IDLEPRIO; | |
1868 | p->se.load.inv_weight = WMULT_IDLEPRIO; | |
1869 | return; | |
1870 | } | |
71f8bd46 | 1871 | |
dd41f596 IM |
1872 | p->se.load.weight = prio_to_weight[p->static_prio - MAX_RT_PRIO]; |
1873 | p->se.load.inv_weight = prio_to_wmult[p->static_prio - MAX_RT_PRIO]; | |
71f8bd46 IM |
1874 | } |
1875 | ||
371fd7e7 | 1876 | static void enqueue_task(struct rq *rq, struct task_struct *p, int flags) |
2087a1ad | 1877 | { |
a64692a3 | 1878 | update_rq_clock(rq); |
dd41f596 | 1879 | sched_info_queued(p); |
371fd7e7 | 1880 | p->sched_class->enqueue_task(rq, p, flags); |
dd41f596 | 1881 | p->se.on_rq = 1; |
71f8bd46 IM |
1882 | } |
1883 | ||
371fd7e7 | 1884 | static void dequeue_task(struct rq *rq, struct task_struct *p, int flags) |
71f8bd46 | 1885 | { |
a64692a3 | 1886 | update_rq_clock(rq); |
46ac22ba | 1887 | sched_info_dequeued(p); |
371fd7e7 | 1888 | p->sched_class->dequeue_task(rq, p, flags); |
dd41f596 | 1889 | p->se.on_rq = 0; |
71f8bd46 IM |
1890 | } |
1891 | ||
1e3c88bd PZ |
1892 | /* |
1893 | * activate_task - move a task to the runqueue. | |
1894 | */ | |
371fd7e7 | 1895 | static void activate_task(struct rq *rq, struct task_struct *p, int flags) |
1e3c88bd PZ |
1896 | { |
1897 | if (task_contributes_to_load(p)) | |
1898 | rq->nr_uninterruptible--; | |
1899 | ||
371fd7e7 | 1900 | enqueue_task(rq, p, flags); |
1e3c88bd PZ |
1901 | inc_nr_running(rq); |
1902 | } | |
1903 | ||
1904 | /* | |
1905 | * deactivate_task - remove a task from the runqueue. | |
1906 | */ | |
371fd7e7 | 1907 | static void deactivate_task(struct rq *rq, struct task_struct *p, int flags) |
1e3c88bd PZ |
1908 | { |
1909 | if (task_contributes_to_load(p)) | |
1910 | rq->nr_uninterruptible++; | |
1911 | ||
371fd7e7 | 1912 | dequeue_task(rq, p, flags); |
1e3c88bd PZ |
1913 | dec_nr_running(rq); |
1914 | } | |
1915 | ||
1916 | #include "sched_idletask.c" | |
1917 | #include "sched_fair.c" | |
1918 | #include "sched_rt.c" | |
1919 | #ifdef CONFIG_SCHED_DEBUG | |
1920 | # include "sched_debug.c" | |
1921 | #endif | |
1922 | ||
14531189 | 1923 | /* |
dd41f596 | 1924 | * __normal_prio - return the priority that is based on the static prio |
14531189 | 1925 | */ |
14531189 IM |
1926 | static inline int __normal_prio(struct task_struct *p) |
1927 | { | |
dd41f596 | 1928 | return p->static_prio; |
14531189 IM |
1929 | } |
1930 | ||
b29739f9 IM |
1931 | /* |
1932 | * Calculate the expected normal priority: i.e. priority | |
1933 | * without taking RT-inheritance into account. Might be | |
1934 | * boosted by interactivity modifiers. Changes upon fork, | |
1935 | * setprio syscalls, and whenever the interactivity | |
1936 | * estimator recalculates. | |
1937 | */ | |
36c8b586 | 1938 | static inline int normal_prio(struct task_struct *p) |
b29739f9 IM |
1939 | { |
1940 | int prio; | |
1941 | ||
e05606d3 | 1942 | if (task_has_rt_policy(p)) |
b29739f9 IM |
1943 | prio = MAX_RT_PRIO-1 - p->rt_priority; |
1944 | else | |
1945 | prio = __normal_prio(p); | |
1946 | return prio; | |
1947 | } | |
1948 | ||
1949 | /* | |
1950 | * Calculate the current priority, i.e. the priority | |
1951 | * taken into account by the scheduler. This value might | |
1952 | * be boosted by RT tasks, or might be boosted by | |
1953 | * interactivity modifiers. Will be RT if the task got | |
1954 | * RT-boosted. If not then it returns p->normal_prio. | |
1955 | */ | |
36c8b586 | 1956 | static int effective_prio(struct task_struct *p) |
b29739f9 IM |
1957 | { |
1958 | p->normal_prio = normal_prio(p); | |
1959 | /* | |
1960 | * If we are RT tasks or we were boosted to RT priority, | |
1961 | * keep the priority unchanged. Otherwise, update priority | |
1962 | * to the normal priority: | |
1963 | */ | |
1964 | if (!rt_prio(p->prio)) | |
1965 | return p->normal_prio; | |
1966 | return p->prio; | |
1967 | } | |
1968 | ||
1da177e4 LT |
1969 | /** |
1970 | * task_curr - is this task currently executing on a CPU? | |
1971 | * @p: the task in question. | |
1972 | */ | |
36c8b586 | 1973 | inline int task_curr(const struct task_struct *p) |
1da177e4 LT |
1974 | { |
1975 | return cpu_curr(task_cpu(p)) == p; | |
1976 | } | |
1977 | ||
cb469845 SR |
1978 | static inline void check_class_changed(struct rq *rq, struct task_struct *p, |
1979 | const struct sched_class *prev_class, | |
1980 | int oldprio, int running) | |
1981 | { | |
1982 | if (prev_class != p->sched_class) { | |
1983 | if (prev_class->switched_from) | |
1984 | prev_class->switched_from(rq, p, running); | |
1985 | p->sched_class->switched_to(rq, p, running); | |
1986 | } else | |
1987 | p->sched_class->prio_changed(rq, p, oldprio, running); | |
1988 | } | |
1989 | ||
1da177e4 | 1990 | #ifdef CONFIG_SMP |
cc367732 IM |
1991 | /* |
1992 | * Is this task likely cache-hot: | |
1993 | */ | |
e7693a36 | 1994 | static int |
cc367732 IM |
1995 | task_hot(struct task_struct *p, u64 now, struct sched_domain *sd) |
1996 | { | |
1997 | s64 delta; | |
1998 | ||
e6c8fba7 PZ |
1999 | if (p->sched_class != &fair_sched_class) |
2000 | return 0; | |
2001 | ||
f540a608 IM |
2002 | /* |
2003 | * Buddy candidates are cache hot: | |
2004 | */ | |
f685ceac | 2005 | if (sched_feat(CACHE_HOT_BUDDY) && this_rq()->nr_running && |
4793241b PZ |
2006 | (&p->se == cfs_rq_of(&p->se)->next || |
2007 | &p->se == cfs_rq_of(&p->se)->last)) | |
f540a608 IM |
2008 | return 1; |
2009 | ||
6bc1665b IM |
2010 | if (sysctl_sched_migration_cost == -1) |
2011 | return 1; | |
2012 | if (sysctl_sched_migration_cost == 0) | |
2013 | return 0; | |
2014 | ||
cc367732 IM |
2015 | delta = now - p->se.exec_start; |
2016 | ||
2017 | return delta < (s64)sysctl_sched_migration_cost; | |
2018 | } | |
2019 | ||
dd41f596 | 2020 | void set_task_cpu(struct task_struct *p, unsigned int new_cpu) |
c65cc870 | 2021 | { |
e2912009 PZ |
2022 | #ifdef CONFIG_SCHED_DEBUG |
2023 | /* | |
2024 | * We should never call set_task_cpu() on a blocked task, | |
2025 | * ttwu() will sort out the placement. | |
2026 | */ | |
077614ee PZ |
2027 | WARN_ON_ONCE(p->state != TASK_RUNNING && p->state != TASK_WAKING && |
2028 | !(task_thread_info(p)->preempt_count & PREEMPT_ACTIVE)); | |
e2912009 PZ |
2029 | #endif |
2030 | ||
de1d7286 | 2031 | trace_sched_migrate_task(p, new_cpu); |
cbc34ed1 | 2032 | |
0c69774e PZ |
2033 | if (task_cpu(p) != new_cpu) { |
2034 | p->se.nr_migrations++; | |
2035 | perf_sw_event(PERF_COUNT_SW_CPU_MIGRATIONS, 1, 1, NULL, 0); | |
2036 | } | |
dd41f596 IM |
2037 | |
2038 | __set_task_cpu(p, new_cpu); | |
c65cc870 IM |
2039 | } |
2040 | ||
969c7921 | 2041 | struct migration_arg { |
36c8b586 | 2042 | struct task_struct *task; |
1da177e4 | 2043 | int dest_cpu; |
70b97a7f | 2044 | }; |
1da177e4 | 2045 | |
969c7921 TH |
2046 | static int migration_cpu_stop(void *data); |
2047 | ||
1da177e4 LT |
2048 | /* |
2049 | * The task's runqueue lock must be held. | |
2050 | * Returns true if you have to wait for migration thread. | |
2051 | */ | |
969c7921 | 2052 | static bool migrate_task(struct task_struct *p, int dest_cpu) |
1da177e4 | 2053 | { |
70b97a7f | 2054 | struct rq *rq = task_rq(p); |
1da177e4 LT |
2055 | |
2056 | /* | |
2057 | * If the task is not on a runqueue (and not running), then | |
e2912009 | 2058 | * the next wake-up will properly place the task. |
1da177e4 | 2059 | */ |
969c7921 | 2060 | return p->se.on_rq || task_running(rq, p); |
1da177e4 LT |
2061 | } |
2062 | ||
2063 | /* | |
2064 | * wait_task_inactive - wait for a thread to unschedule. | |
2065 | * | |
85ba2d86 RM |
2066 | * If @match_state is nonzero, it's the @p->state value just checked and |
2067 | * not expected to change. If it changes, i.e. @p might have woken up, | |
2068 | * then return zero. When we succeed in waiting for @p to be off its CPU, | |
2069 | * we return a positive number (its total switch count). If a second call | |
2070 | * a short while later returns the same number, the caller can be sure that | |
2071 | * @p has remained unscheduled the whole time. | |
2072 | * | |
1da177e4 LT |
2073 | * The caller must ensure that the task *will* unschedule sometime soon, |
2074 | * else this function might spin for a *long* time. This function can't | |
2075 | * be called with interrupts off, or it may introduce deadlock with | |
2076 | * smp_call_function() if an IPI is sent by the same process we are | |
2077 | * waiting to become inactive. | |
2078 | */ | |
85ba2d86 | 2079 | unsigned long wait_task_inactive(struct task_struct *p, long match_state) |
1da177e4 LT |
2080 | { |
2081 | unsigned long flags; | |
dd41f596 | 2082 | int running, on_rq; |
85ba2d86 | 2083 | unsigned long ncsw; |
70b97a7f | 2084 | struct rq *rq; |
1da177e4 | 2085 | |
3a5c359a AK |
2086 | for (;;) { |
2087 | /* | |
2088 | * We do the initial early heuristics without holding | |
2089 | * any task-queue locks at all. We'll only try to get | |
2090 | * the runqueue lock when things look like they will | |
2091 | * work out! | |
2092 | */ | |
2093 | rq = task_rq(p); | |
fa490cfd | 2094 | |
3a5c359a AK |
2095 | /* |
2096 | * If the task is actively running on another CPU | |
2097 | * still, just relax and busy-wait without holding | |
2098 | * any locks. | |
2099 | * | |
2100 | * NOTE! Since we don't hold any locks, it's not | |
2101 | * even sure that "rq" stays as the right runqueue! | |
2102 | * But we don't care, since "task_running()" will | |
2103 | * return false if the runqueue has changed and p | |
2104 | * is actually now running somewhere else! | |
2105 | */ | |
85ba2d86 RM |
2106 | while (task_running(rq, p)) { |
2107 | if (match_state && unlikely(p->state != match_state)) | |
2108 | return 0; | |
3a5c359a | 2109 | cpu_relax(); |
85ba2d86 | 2110 | } |
fa490cfd | 2111 | |
3a5c359a AK |
2112 | /* |
2113 | * Ok, time to look more closely! We need the rq | |
2114 | * lock now, to be *sure*. If we're wrong, we'll | |
2115 | * just go back and repeat. | |
2116 | */ | |
2117 | rq = task_rq_lock(p, &flags); | |
27a9da65 | 2118 | trace_sched_wait_task(p); |
3a5c359a AK |
2119 | running = task_running(rq, p); |
2120 | on_rq = p->se.on_rq; | |
85ba2d86 | 2121 | ncsw = 0; |
f31e11d8 | 2122 | if (!match_state || p->state == match_state) |
93dcf55f | 2123 | ncsw = p->nvcsw | LONG_MIN; /* sets MSB */ |
3a5c359a | 2124 | task_rq_unlock(rq, &flags); |
fa490cfd | 2125 | |
85ba2d86 RM |
2126 | /* |
2127 | * If it changed from the expected state, bail out now. | |
2128 | */ | |
2129 | if (unlikely(!ncsw)) | |
2130 | break; | |
2131 | ||
3a5c359a AK |
2132 | /* |
2133 | * Was it really running after all now that we | |
2134 | * checked with the proper locks actually held? | |
2135 | * | |
2136 | * Oops. Go back and try again.. | |
2137 | */ | |
2138 | if (unlikely(running)) { | |
2139 | cpu_relax(); | |
2140 | continue; | |
2141 | } | |
fa490cfd | 2142 | |
3a5c359a AK |
2143 | /* |
2144 | * It's not enough that it's not actively running, | |
2145 | * it must be off the runqueue _entirely_, and not | |
2146 | * preempted! | |
2147 | * | |
80dd99b3 | 2148 | * So if it was still runnable (but just not actively |
3a5c359a AK |
2149 | * running right now), it's preempted, and we should |
2150 | * yield - it could be a while. | |
2151 | */ | |
2152 | if (unlikely(on_rq)) { | |
2153 | schedule_timeout_uninterruptible(1); | |
2154 | continue; | |
2155 | } | |
fa490cfd | 2156 | |
3a5c359a AK |
2157 | /* |
2158 | * Ahh, all good. It wasn't running, and it wasn't | |
2159 | * runnable, which means that it will never become | |
2160 | * running in the future either. We're all done! | |
2161 | */ | |
2162 | break; | |
2163 | } | |
85ba2d86 RM |
2164 | |
2165 | return ncsw; | |
1da177e4 LT |
2166 | } |
2167 | ||
2168 | /*** | |
2169 | * kick_process - kick a running thread to enter/exit the kernel | |
2170 | * @p: the to-be-kicked thread | |
2171 | * | |
2172 | * Cause a process which is running on another CPU to enter | |
2173 | * kernel-mode, without any delay. (to get signals handled.) | |
2174 | * | |
2175 | * NOTE: this function doesnt have to take the runqueue lock, | |
2176 | * because all it wants to ensure is that the remote task enters | |
2177 | * the kernel. If the IPI races and the task has been migrated | |
2178 | * to another CPU then no harm is done and the purpose has been | |
2179 | * achieved as well. | |
2180 | */ | |
36c8b586 | 2181 | void kick_process(struct task_struct *p) |
1da177e4 LT |
2182 | { |
2183 | int cpu; | |
2184 | ||
2185 | preempt_disable(); | |
2186 | cpu = task_cpu(p); | |
2187 | if ((cpu != smp_processor_id()) && task_curr(p)) | |
2188 | smp_send_reschedule(cpu); | |
2189 | preempt_enable(); | |
2190 | } | |
b43e3521 | 2191 | EXPORT_SYMBOL_GPL(kick_process); |
476d139c | 2192 | #endif /* CONFIG_SMP */ |
1da177e4 | 2193 | |
0793a61d TG |
2194 | /** |
2195 | * task_oncpu_function_call - call a function on the cpu on which a task runs | |
2196 | * @p: the task to evaluate | |
2197 | * @func: the function to be called | |
2198 | * @info: the function call argument | |
2199 | * | |
2200 | * Calls the function @func when the task is currently running. This might | |
2201 | * be on the current CPU, which just calls the function directly | |
2202 | */ | |
2203 | void task_oncpu_function_call(struct task_struct *p, | |
2204 | void (*func) (void *info), void *info) | |
2205 | { | |
2206 | int cpu; | |
2207 | ||
2208 | preempt_disable(); | |
2209 | cpu = task_cpu(p); | |
2210 | if (task_curr(p)) | |
2211 | smp_call_function_single(cpu, func, info, 1); | |
2212 | preempt_enable(); | |
2213 | } | |
2214 | ||
970b13ba | 2215 | #ifdef CONFIG_SMP |
30da688e ON |
2216 | /* |
2217 | * ->cpus_allowed is protected by either TASK_WAKING or rq->lock held. | |
2218 | */ | |
5da9a0fb PZ |
2219 | static int select_fallback_rq(int cpu, struct task_struct *p) |
2220 | { | |
2221 | int dest_cpu; | |
2222 | const struct cpumask *nodemask = cpumask_of_node(cpu_to_node(cpu)); | |
2223 | ||
2224 | /* Look for allowed, online CPU in same node. */ | |
2225 | for_each_cpu_and(dest_cpu, nodemask, cpu_active_mask) | |
2226 | if (cpumask_test_cpu(dest_cpu, &p->cpus_allowed)) | |
2227 | return dest_cpu; | |
2228 | ||
2229 | /* Any allowed, online CPU? */ | |
2230 | dest_cpu = cpumask_any_and(&p->cpus_allowed, cpu_active_mask); | |
2231 | if (dest_cpu < nr_cpu_ids) | |
2232 | return dest_cpu; | |
2233 | ||
2234 | /* No more Mr. Nice Guy. */ | |
897f0b3c | 2235 | if (unlikely(dest_cpu >= nr_cpu_ids)) { |
9084bb82 | 2236 | dest_cpu = cpuset_cpus_allowed_fallback(p); |
5da9a0fb PZ |
2237 | /* |
2238 | * Don't tell them about moving exiting tasks or | |
2239 | * kernel threads (both mm NULL), since they never | |
2240 | * leave kernel. | |
2241 | */ | |
2242 | if (p->mm && printk_ratelimit()) { | |
2243 | printk(KERN_INFO "process %d (%s) no " | |
2244 | "longer affine to cpu%d\n", | |
2245 | task_pid_nr(p), p->comm, cpu); | |
2246 | } | |
2247 | } | |
2248 | ||
2249 | return dest_cpu; | |
2250 | } | |
2251 | ||
e2912009 | 2252 | /* |
30da688e | 2253 | * The caller (fork, wakeup) owns TASK_WAKING, ->cpus_allowed is stable. |
e2912009 | 2254 | */ |
970b13ba | 2255 | static inline |
0017d735 | 2256 | int select_task_rq(struct rq *rq, struct task_struct *p, int sd_flags, int wake_flags) |
970b13ba | 2257 | { |
0017d735 | 2258 | int cpu = p->sched_class->select_task_rq(rq, p, sd_flags, wake_flags); |
e2912009 PZ |
2259 | |
2260 | /* | |
2261 | * In order not to call set_task_cpu() on a blocking task we need | |
2262 | * to rely on ttwu() to place the task on a valid ->cpus_allowed | |
2263 | * cpu. | |
2264 | * | |
2265 | * Since this is common to all placement strategies, this lives here. | |
2266 | * | |
2267 | * [ this allows ->select_task() to simply return task_cpu(p) and | |
2268 | * not worry about this generic constraint ] | |
2269 | */ | |
2270 | if (unlikely(!cpumask_test_cpu(cpu, &p->cpus_allowed) || | |
70f11205 | 2271 | !cpu_online(cpu))) |
5da9a0fb | 2272 | cpu = select_fallback_rq(task_cpu(p), p); |
e2912009 PZ |
2273 | |
2274 | return cpu; | |
970b13ba | 2275 | } |
09a40af5 MG |
2276 | |
2277 | static void update_avg(u64 *avg, u64 sample) | |
2278 | { | |
2279 | s64 diff = sample - *avg; | |
2280 | *avg += diff >> 3; | |
2281 | } | |
970b13ba PZ |
2282 | #endif |
2283 | ||
9ed3811a TH |
2284 | static inline void ttwu_activate(struct task_struct *p, struct rq *rq, |
2285 | bool is_sync, bool is_migrate, bool is_local, | |
2286 | unsigned long en_flags) | |
2287 | { | |
2288 | schedstat_inc(p, se.statistics.nr_wakeups); | |
2289 | if (is_sync) | |
2290 | schedstat_inc(p, se.statistics.nr_wakeups_sync); | |
2291 | if (is_migrate) | |
2292 | schedstat_inc(p, se.statistics.nr_wakeups_migrate); | |
2293 | if (is_local) | |
2294 | schedstat_inc(p, se.statistics.nr_wakeups_local); | |
2295 | else | |
2296 | schedstat_inc(p, se.statistics.nr_wakeups_remote); | |
2297 | ||
2298 | activate_task(rq, p, en_flags); | |
2299 | } | |
2300 | ||
2301 | static inline void ttwu_post_activation(struct task_struct *p, struct rq *rq, | |
2302 | int wake_flags, bool success) | |
2303 | { | |
2304 | trace_sched_wakeup(p, success); | |
2305 | check_preempt_curr(rq, p, wake_flags); | |
2306 | ||
2307 | p->state = TASK_RUNNING; | |
2308 | #ifdef CONFIG_SMP | |
2309 | if (p->sched_class->task_woken) | |
2310 | p->sched_class->task_woken(rq, p); | |
2311 | ||
2312 | if (unlikely(rq->idle_stamp)) { | |
2313 | u64 delta = rq->clock - rq->idle_stamp; | |
2314 | u64 max = 2*sysctl_sched_migration_cost; | |
2315 | ||
2316 | if (delta > max) | |
2317 | rq->avg_idle = max; | |
2318 | else | |
2319 | update_avg(&rq->avg_idle, delta); | |
2320 | rq->idle_stamp = 0; | |
2321 | } | |
2322 | #endif | |
21aa9af0 TH |
2323 | /* if a worker is waking up, notify workqueue */ |
2324 | if ((p->flags & PF_WQ_WORKER) && success) | |
2325 | wq_worker_waking_up(p, cpu_of(rq)); | |
9ed3811a TH |
2326 | } |
2327 | ||
2328 | /** | |
1da177e4 | 2329 | * try_to_wake_up - wake up a thread |
9ed3811a | 2330 | * @p: the thread to be awakened |
1da177e4 | 2331 | * @state: the mask of task states that can be woken |
9ed3811a | 2332 | * @wake_flags: wake modifier flags (WF_*) |
1da177e4 LT |
2333 | * |
2334 | * Put it on the run-queue if it's not already there. The "current" | |
2335 | * thread is always on the run-queue (except when the actual | |
2336 | * re-schedule is in progress), and as such you're allowed to do | |
2337 | * the simpler "current->state = TASK_RUNNING" to mark yourself | |
2338 | * runnable without the overhead of this. | |
2339 | * | |
9ed3811a TH |
2340 | * Returns %true if @p was woken up, %false if it was already running |
2341 | * or @state didn't match @p's state. | |
1da177e4 | 2342 | */ |
7d478721 PZ |
2343 | static int try_to_wake_up(struct task_struct *p, unsigned int state, |
2344 | int wake_flags) | |
1da177e4 | 2345 | { |
cc367732 | 2346 | int cpu, orig_cpu, this_cpu, success = 0; |
1da177e4 | 2347 | unsigned long flags; |
371fd7e7 | 2348 | unsigned long en_flags = ENQUEUE_WAKEUP; |
ab3b3aa5 | 2349 | struct rq *rq; |
1da177e4 | 2350 | |
e9c84311 | 2351 | this_cpu = get_cpu(); |
2398f2c6 | 2352 | |
04e2f174 | 2353 | smp_wmb(); |
ab3b3aa5 | 2354 | rq = task_rq_lock(p, &flags); |
e9c84311 | 2355 | if (!(p->state & state)) |
1da177e4 LT |
2356 | goto out; |
2357 | ||
dd41f596 | 2358 | if (p->se.on_rq) |
1da177e4 LT |
2359 | goto out_running; |
2360 | ||
2361 | cpu = task_cpu(p); | |
cc367732 | 2362 | orig_cpu = cpu; |
1da177e4 LT |
2363 | |
2364 | #ifdef CONFIG_SMP | |
2365 | if (unlikely(task_running(rq, p))) | |
2366 | goto out_activate; | |
2367 | ||
e9c84311 PZ |
2368 | /* |
2369 | * In order to handle concurrent wakeups and release the rq->lock | |
2370 | * we put the task in TASK_WAKING state. | |
eb24073b IM |
2371 | * |
2372 | * First fix up the nr_uninterruptible count: | |
e9c84311 | 2373 | */ |
cc87f76a PZ |
2374 | if (task_contributes_to_load(p)) { |
2375 | if (likely(cpu_online(orig_cpu))) | |
2376 | rq->nr_uninterruptible--; | |
2377 | else | |
2378 | this_rq()->nr_uninterruptible--; | |
2379 | } | |
e9c84311 | 2380 | p->state = TASK_WAKING; |
efbbd05a | 2381 | |
371fd7e7 | 2382 | if (p->sched_class->task_waking) { |
efbbd05a | 2383 | p->sched_class->task_waking(rq, p); |
371fd7e7 PZ |
2384 | en_flags |= ENQUEUE_WAKING; |
2385 | } | |
efbbd05a | 2386 | |
0017d735 PZ |
2387 | cpu = select_task_rq(rq, p, SD_BALANCE_WAKE, wake_flags); |
2388 | if (cpu != orig_cpu) | |
5d2f5a61 | 2389 | set_task_cpu(p, cpu); |
0017d735 | 2390 | __task_rq_unlock(rq); |
ab19cb23 | 2391 | |
0970d299 PZ |
2392 | rq = cpu_rq(cpu); |
2393 | raw_spin_lock(&rq->lock); | |
f5dc3753 | 2394 | |
0970d299 PZ |
2395 | /* |
2396 | * We migrated the task without holding either rq->lock, however | |
2397 | * since the task is not on the task list itself, nobody else | |
2398 | * will try and migrate the task, hence the rq should match the | |
2399 | * cpu we just moved it to. | |
2400 | */ | |
2401 | WARN_ON(task_cpu(p) != cpu); | |
e9c84311 | 2402 | WARN_ON(p->state != TASK_WAKING); |
1da177e4 | 2403 | |
e7693a36 GH |
2404 | #ifdef CONFIG_SCHEDSTATS |
2405 | schedstat_inc(rq, ttwu_count); | |
2406 | if (cpu == this_cpu) | |
2407 | schedstat_inc(rq, ttwu_local); | |
2408 | else { | |
2409 | struct sched_domain *sd; | |
2410 | for_each_domain(this_cpu, sd) { | |
758b2cdc | 2411 | if (cpumask_test_cpu(cpu, sched_domain_span(sd))) { |
e7693a36 GH |
2412 | schedstat_inc(sd, ttwu_wake_remote); |
2413 | break; | |
2414 | } | |
2415 | } | |
2416 | } | |
6d6bc0ad | 2417 | #endif /* CONFIG_SCHEDSTATS */ |
e7693a36 | 2418 | |
1da177e4 LT |
2419 | out_activate: |
2420 | #endif /* CONFIG_SMP */ | |
9ed3811a TH |
2421 | ttwu_activate(p, rq, wake_flags & WF_SYNC, orig_cpu != cpu, |
2422 | cpu == this_cpu, en_flags); | |
1da177e4 | 2423 | success = 1; |
1da177e4 | 2424 | out_running: |
9ed3811a | 2425 | ttwu_post_activation(p, rq, wake_flags, success); |
1da177e4 LT |
2426 | out: |
2427 | task_rq_unlock(rq, &flags); | |
e9c84311 | 2428 | put_cpu(); |
1da177e4 LT |
2429 | |
2430 | return success; | |
2431 | } | |
2432 | ||
21aa9af0 TH |
2433 | /** |
2434 | * try_to_wake_up_local - try to wake up a local task with rq lock held | |
2435 | * @p: the thread to be awakened | |
2436 | * | |
2437 | * Put @p on the run-queue if it's not alredy there. The caller must | |
2438 | * ensure that this_rq() is locked, @p is bound to this_rq() and not | |
2439 | * the current task. this_rq() stays locked over invocation. | |
2440 | */ | |
2441 | static void try_to_wake_up_local(struct task_struct *p) | |
2442 | { | |
2443 | struct rq *rq = task_rq(p); | |
2444 | bool success = false; | |
2445 | ||
2446 | BUG_ON(rq != this_rq()); | |
2447 | BUG_ON(p == current); | |
2448 | lockdep_assert_held(&rq->lock); | |
2449 | ||
2450 | if (!(p->state & TASK_NORMAL)) | |
2451 | return; | |
2452 | ||
2453 | if (!p->se.on_rq) { | |
2454 | if (likely(!task_running(rq, p))) { | |
2455 | schedstat_inc(rq, ttwu_count); | |
2456 | schedstat_inc(rq, ttwu_local); | |
2457 | } | |
2458 | ttwu_activate(p, rq, false, false, true, ENQUEUE_WAKEUP); | |
2459 | success = true; | |
2460 | } | |
2461 | ttwu_post_activation(p, rq, 0, success); | |
2462 | } | |
2463 | ||
50fa610a DH |
2464 | /** |
2465 | * wake_up_process - Wake up a specific process | |
2466 | * @p: The process to be woken up. | |
2467 | * | |
2468 | * Attempt to wake up the nominated process and move it to the set of runnable | |
2469 | * processes. Returns 1 if the process was woken up, 0 if it was already | |
2470 | * running. | |
2471 | * | |
2472 | * It may be assumed that this function implies a write memory barrier before | |
2473 | * changing the task state if and only if any tasks are woken up. | |
2474 | */ | |
7ad5b3a5 | 2475 | int wake_up_process(struct task_struct *p) |
1da177e4 | 2476 | { |
d9514f6c | 2477 | return try_to_wake_up(p, TASK_ALL, 0); |
1da177e4 | 2478 | } |
1da177e4 LT |
2479 | EXPORT_SYMBOL(wake_up_process); |
2480 | ||
7ad5b3a5 | 2481 | int wake_up_state(struct task_struct *p, unsigned int state) |
1da177e4 LT |
2482 | { |
2483 | return try_to_wake_up(p, state, 0); | |
2484 | } | |
2485 | ||
1da177e4 LT |
2486 | /* |
2487 | * Perform scheduler related setup for a newly forked process p. | |
2488 | * p is forked by current. | |
dd41f596 IM |
2489 | * |
2490 | * __sched_fork() is basic setup used by init_idle() too: | |
2491 | */ | |
2492 | static void __sched_fork(struct task_struct *p) | |
2493 | { | |
dd41f596 IM |
2494 | p->se.exec_start = 0; |
2495 | p->se.sum_exec_runtime = 0; | |
f6cf891c | 2496 | p->se.prev_sum_exec_runtime = 0; |
6c594c21 | 2497 | p->se.nr_migrations = 0; |
6cfb0d5d IM |
2498 | |
2499 | #ifdef CONFIG_SCHEDSTATS | |
41acab88 | 2500 | memset(&p->se.statistics, 0, sizeof(p->se.statistics)); |
6cfb0d5d | 2501 | #endif |
476d139c | 2502 | |
fa717060 | 2503 | INIT_LIST_HEAD(&p->rt.run_list); |
dd41f596 | 2504 | p->se.on_rq = 0; |
4a55bd5e | 2505 | INIT_LIST_HEAD(&p->se.group_node); |
476d139c | 2506 | |
e107be36 AK |
2507 | #ifdef CONFIG_PREEMPT_NOTIFIERS |
2508 | INIT_HLIST_HEAD(&p->preempt_notifiers); | |
2509 | #endif | |
dd41f596 IM |
2510 | } |
2511 | ||
2512 | /* | |
2513 | * fork()/clone()-time setup: | |
2514 | */ | |
2515 | void sched_fork(struct task_struct *p, int clone_flags) | |
2516 | { | |
2517 | int cpu = get_cpu(); | |
2518 | ||
2519 | __sched_fork(p); | |
06b83b5f | 2520 | /* |
0017d735 | 2521 | * We mark the process as running here. This guarantees that |
06b83b5f PZ |
2522 | * nobody will actually run it, and a signal or other external |
2523 | * event cannot wake it up and insert it on the runqueue either. | |
2524 | */ | |
0017d735 | 2525 | p->state = TASK_RUNNING; |
dd41f596 | 2526 | |
b9dc29e7 MG |
2527 | /* |
2528 | * Revert to default priority/policy on fork if requested. | |
2529 | */ | |
2530 | if (unlikely(p->sched_reset_on_fork)) { | |
f83f9ac2 | 2531 | if (p->policy == SCHED_FIFO || p->policy == SCHED_RR) { |
b9dc29e7 | 2532 | p->policy = SCHED_NORMAL; |
f83f9ac2 PW |
2533 | p->normal_prio = p->static_prio; |
2534 | } | |
b9dc29e7 | 2535 | |
6c697bdf MG |
2536 | if (PRIO_TO_NICE(p->static_prio) < 0) { |
2537 | p->static_prio = NICE_TO_PRIO(0); | |
f83f9ac2 | 2538 | p->normal_prio = p->static_prio; |
6c697bdf MG |
2539 | set_load_weight(p); |
2540 | } | |
2541 | ||
b9dc29e7 MG |
2542 | /* |
2543 | * We don't need the reset flag anymore after the fork. It has | |
2544 | * fulfilled its duty: | |
2545 | */ | |
2546 | p->sched_reset_on_fork = 0; | |
2547 | } | |
ca94c442 | 2548 | |
f83f9ac2 PW |
2549 | /* |
2550 | * Make sure we do not leak PI boosting priority to the child. | |
2551 | */ | |
2552 | p->prio = current->normal_prio; | |
2553 | ||
2ddbf952 HS |
2554 | if (!rt_prio(p->prio)) |
2555 | p->sched_class = &fair_sched_class; | |
b29739f9 | 2556 | |
cd29fe6f PZ |
2557 | if (p->sched_class->task_fork) |
2558 | p->sched_class->task_fork(p); | |
2559 | ||
86951599 PZ |
2560 | /* |
2561 | * The child is not yet in the pid-hash so no cgroup attach races, | |
2562 | * and the cgroup is pinned to this child due to cgroup_fork() | |
2563 | * is ran before sched_fork(). | |
2564 | * | |
2565 | * Silence PROVE_RCU. | |
2566 | */ | |
2567 | rcu_read_lock(); | |
5f3edc1b | 2568 | set_task_cpu(p, cpu); |
86951599 | 2569 | rcu_read_unlock(); |
5f3edc1b | 2570 | |
52f17b6c | 2571 | #if defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT) |
dd41f596 | 2572 | if (likely(sched_info_on())) |
52f17b6c | 2573 | memset(&p->sched_info, 0, sizeof(p->sched_info)); |
1da177e4 | 2574 | #endif |
d6077cb8 | 2575 | #if defined(CONFIG_SMP) && defined(__ARCH_WANT_UNLOCKED_CTXSW) |
4866cde0 NP |
2576 | p->oncpu = 0; |
2577 | #endif | |
1da177e4 | 2578 | #ifdef CONFIG_PREEMPT |
4866cde0 | 2579 | /* Want to start with kernel preemption disabled. */ |
a1261f54 | 2580 | task_thread_info(p)->preempt_count = 1; |
1da177e4 | 2581 | #endif |
917b627d GH |
2582 | plist_node_init(&p->pushable_tasks, MAX_PRIO); |
2583 | ||
476d139c | 2584 | put_cpu(); |
1da177e4 LT |
2585 | } |
2586 | ||
2587 | /* | |
2588 | * wake_up_new_task - wake up a newly created task for the first time. | |
2589 | * | |
2590 | * This function will do some initial scheduler statistics housekeeping | |
2591 | * that must be done for every newly created context, then puts the task | |
2592 | * on the runqueue and wakes it. | |
2593 | */ | |
7ad5b3a5 | 2594 | void wake_up_new_task(struct task_struct *p, unsigned long clone_flags) |
1da177e4 LT |
2595 | { |
2596 | unsigned long flags; | |
dd41f596 | 2597 | struct rq *rq; |
c890692b | 2598 | int cpu __maybe_unused = get_cpu(); |
fabf318e PZ |
2599 | |
2600 | #ifdef CONFIG_SMP | |
0017d735 PZ |
2601 | rq = task_rq_lock(p, &flags); |
2602 | p->state = TASK_WAKING; | |
2603 | ||
fabf318e PZ |
2604 | /* |
2605 | * Fork balancing, do it here and not earlier because: | |
2606 | * - cpus_allowed can change in the fork path | |
2607 | * - any previously selected cpu might disappear through hotplug | |
2608 | * | |
0017d735 PZ |
2609 | * We set TASK_WAKING so that select_task_rq() can drop rq->lock |
2610 | * without people poking at ->cpus_allowed. | |
fabf318e | 2611 | */ |
0017d735 | 2612 | cpu = select_task_rq(rq, p, SD_BALANCE_FORK, 0); |
fabf318e | 2613 | set_task_cpu(p, cpu); |
1da177e4 | 2614 | |
06b83b5f | 2615 | p->state = TASK_RUNNING; |
0017d735 PZ |
2616 | task_rq_unlock(rq, &flags); |
2617 | #endif | |
2618 | ||
2619 | rq = task_rq_lock(p, &flags); | |
cd29fe6f | 2620 | activate_task(rq, p, 0); |
27a9da65 | 2621 | trace_sched_wakeup_new(p, 1); |
a7558e01 | 2622 | check_preempt_curr(rq, p, WF_FORK); |
9a897c5a | 2623 | #ifdef CONFIG_SMP |
efbbd05a PZ |
2624 | if (p->sched_class->task_woken) |
2625 | p->sched_class->task_woken(rq, p); | |
9a897c5a | 2626 | #endif |
dd41f596 | 2627 | task_rq_unlock(rq, &flags); |
fabf318e | 2628 | put_cpu(); |
1da177e4 LT |
2629 | } |
2630 | ||
e107be36 AK |
2631 | #ifdef CONFIG_PREEMPT_NOTIFIERS |
2632 | ||
2633 | /** | |
80dd99b3 | 2634 | * preempt_notifier_register - tell me when current is being preempted & rescheduled |
421cee29 | 2635 | * @notifier: notifier struct to register |
e107be36 AK |
2636 | */ |
2637 | void preempt_notifier_register(struct preempt_notifier *notifier) | |
2638 | { | |
2639 | hlist_add_head(¬ifier->link, ¤t->preempt_notifiers); | |
2640 | } | |
2641 | EXPORT_SYMBOL_GPL(preempt_notifier_register); | |
2642 | ||
2643 | /** | |
2644 | * preempt_notifier_unregister - no longer interested in preemption notifications | |
421cee29 | 2645 | * @notifier: notifier struct to unregister |
e107be36 AK |
2646 | * |
2647 | * This is safe to call from within a preemption notifier. | |
2648 | */ | |
2649 | void preempt_notifier_unregister(struct preempt_notifier *notifier) | |
2650 | { | |
2651 | hlist_del(¬ifier->link); | |
2652 | } | |
2653 | EXPORT_SYMBOL_GPL(preempt_notifier_unregister); | |
2654 | ||
2655 | static void fire_sched_in_preempt_notifiers(struct task_struct *curr) | |
2656 | { | |
2657 | struct preempt_notifier *notifier; | |
2658 | struct hlist_node *node; | |
2659 | ||
2660 | hlist_for_each_entry(notifier, node, &curr->preempt_notifiers, link) | |
2661 | notifier->ops->sched_in(notifier, raw_smp_processor_id()); | |
2662 | } | |
2663 | ||
2664 | static void | |
2665 | fire_sched_out_preempt_notifiers(struct task_struct *curr, | |
2666 | struct task_struct *next) | |
2667 | { | |
2668 | struct preempt_notifier *notifier; | |
2669 | struct hlist_node *node; | |
2670 | ||
2671 | hlist_for_each_entry(notifier, node, &curr->preempt_notifiers, link) | |
2672 | notifier->ops->sched_out(notifier, next); | |
2673 | } | |
2674 | ||
6d6bc0ad | 2675 | #else /* !CONFIG_PREEMPT_NOTIFIERS */ |
e107be36 AK |
2676 | |
2677 | static void fire_sched_in_preempt_notifiers(struct task_struct *curr) | |
2678 | { | |
2679 | } | |
2680 | ||
2681 | static void | |
2682 | fire_sched_out_preempt_notifiers(struct task_struct *curr, | |
2683 | struct task_struct *next) | |
2684 | { | |
2685 | } | |
2686 | ||
6d6bc0ad | 2687 | #endif /* CONFIG_PREEMPT_NOTIFIERS */ |
e107be36 | 2688 | |
4866cde0 NP |
2689 | /** |
2690 | * prepare_task_switch - prepare to switch tasks | |
2691 | * @rq: the runqueue preparing to switch | |
421cee29 | 2692 | * @prev: the current task that is being switched out |
4866cde0 NP |
2693 | * @next: the task we are going to switch to. |
2694 | * | |
2695 | * This is called with the rq lock held and interrupts off. It must | |
2696 | * be paired with a subsequent finish_task_switch after the context | |
2697 | * switch. | |
2698 | * | |
2699 | * prepare_task_switch sets up locking and calls architecture specific | |
2700 | * hooks. | |
2701 | */ | |
e107be36 AK |
2702 | static inline void |
2703 | prepare_task_switch(struct rq *rq, struct task_struct *prev, | |
2704 | struct task_struct *next) | |
4866cde0 | 2705 | { |
e107be36 | 2706 | fire_sched_out_preempt_notifiers(prev, next); |
4866cde0 NP |
2707 | prepare_lock_switch(rq, next); |
2708 | prepare_arch_switch(next); | |
2709 | } | |
2710 | ||
1da177e4 LT |
2711 | /** |
2712 | * finish_task_switch - clean up after a task-switch | |
344babaa | 2713 | * @rq: runqueue associated with task-switch |
1da177e4 LT |
2714 | * @prev: the thread we just switched away from. |
2715 | * | |
4866cde0 NP |
2716 | * finish_task_switch must be called after the context switch, paired |
2717 | * with a prepare_task_switch call before the context switch. | |
2718 | * finish_task_switch will reconcile locking set up by prepare_task_switch, | |
2719 | * and do any other architecture-specific cleanup actions. | |
1da177e4 LT |
2720 | * |
2721 | * Note that we may have delayed dropping an mm in context_switch(). If | |
41a2d6cf | 2722 | * so, we finish that here outside of the runqueue lock. (Doing it |
1da177e4 LT |
2723 | * with the lock held can cause deadlocks; see schedule() for |
2724 | * details.) | |
2725 | */ | |
a9957449 | 2726 | static void finish_task_switch(struct rq *rq, struct task_struct *prev) |
1da177e4 LT |
2727 | __releases(rq->lock) |
2728 | { | |
1da177e4 | 2729 | struct mm_struct *mm = rq->prev_mm; |
55a101f8 | 2730 | long prev_state; |
1da177e4 LT |
2731 | |
2732 | rq->prev_mm = NULL; | |
2733 | ||
2734 | /* | |
2735 | * A task struct has one reference for the use as "current". | |
c394cc9f | 2736 | * If a task dies, then it sets TASK_DEAD in tsk->state and calls |
55a101f8 ON |
2737 | * schedule one last time. The schedule call will never return, and |
2738 | * the scheduled task must drop that reference. | |
c394cc9f | 2739 | * The test for TASK_DEAD must occur while the runqueue locks are |
1da177e4 LT |
2740 | * still held, otherwise prev could be scheduled on another cpu, die |
2741 | * there before we look at prev->state, and then the reference would | |
2742 | * be dropped twice. | |
2743 | * Manfred Spraul <manfred@colorfullife.com> | |
2744 | */ | |
55a101f8 | 2745 | prev_state = prev->state; |
4866cde0 | 2746 | finish_arch_switch(prev); |
8381f65d JI |
2747 | #ifdef __ARCH_WANT_INTERRUPTS_ON_CTXSW |
2748 | local_irq_disable(); | |
2749 | #endif /* __ARCH_WANT_INTERRUPTS_ON_CTXSW */ | |
49f47433 | 2750 | perf_event_task_sched_in(current); |
8381f65d JI |
2751 | #ifdef __ARCH_WANT_INTERRUPTS_ON_CTXSW |
2752 | local_irq_enable(); | |
2753 | #endif /* __ARCH_WANT_INTERRUPTS_ON_CTXSW */ | |
4866cde0 | 2754 | finish_lock_switch(rq, prev); |
e8fa1362 | 2755 | |
e107be36 | 2756 | fire_sched_in_preempt_notifiers(current); |
1da177e4 LT |
2757 | if (mm) |
2758 | mmdrop(mm); | |
c394cc9f | 2759 | if (unlikely(prev_state == TASK_DEAD)) { |
c6fd91f0 | 2760 | /* |
2761 | * Remove function-return probe instances associated with this | |
2762 | * task and put them back on the free list. | |
9761eea8 | 2763 | */ |
c6fd91f0 | 2764 | kprobe_flush_task(prev); |
1da177e4 | 2765 | put_task_struct(prev); |
c6fd91f0 | 2766 | } |
1da177e4 LT |
2767 | } |
2768 | ||
3f029d3c GH |
2769 | #ifdef CONFIG_SMP |
2770 | ||
2771 | /* assumes rq->lock is held */ | |
2772 | static inline void pre_schedule(struct rq *rq, struct task_struct *prev) | |
2773 | { | |
2774 | if (prev->sched_class->pre_schedule) | |
2775 | prev->sched_class->pre_schedule(rq, prev); | |
2776 | } | |
2777 | ||
2778 | /* rq->lock is NOT held, but preemption is disabled */ | |
2779 | static inline void post_schedule(struct rq *rq) | |
2780 | { | |
2781 | if (rq->post_schedule) { | |
2782 | unsigned long flags; | |
2783 | ||
05fa785c | 2784 | raw_spin_lock_irqsave(&rq->lock, flags); |
3f029d3c GH |
2785 | if (rq->curr->sched_class->post_schedule) |
2786 | rq->curr->sched_class->post_schedule(rq); | |
05fa785c | 2787 | raw_spin_unlock_irqrestore(&rq->lock, flags); |
3f029d3c GH |
2788 | |
2789 | rq->post_schedule = 0; | |
2790 | } | |
2791 | } | |
2792 | ||
2793 | #else | |
da19ab51 | 2794 | |
3f029d3c GH |
2795 | static inline void pre_schedule(struct rq *rq, struct task_struct *p) |
2796 | { | |
2797 | } | |
2798 | ||
2799 | static inline void post_schedule(struct rq *rq) | |
2800 | { | |
1da177e4 LT |
2801 | } |
2802 | ||
3f029d3c GH |
2803 | #endif |
2804 | ||
1da177e4 LT |
2805 | /** |
2806 | * schedule_tail - first thing a freshly forked thread must call. | |
2807 | * @prev: the thread we just switched away from. | |
2808 | */ | |
36c8b586 | 2809 | asmlinkage void schedule_tail(struct task_struct *prev) |
1da177e4 LT |
2810 | __releases(rq->lock) |
2811 | { | |
70b97a7f IM |
2812 | struct rq *rq = this_rq(); |
2813 | ||
4866cde0 | 2814 | finish_task_switch(rq, prev); |
da19ab51 | 2815 | |
3f029d3c GH |
2816 | /* |
2817 | * FIXME: do we need to worry about rq being invalidated by the | |
2818 | * task_switch? | |
2819 | */ | |
2820 | post_schedule(rq); | |
70b97a7f | 2821 | |
4866cde0 NP |
2822 | #ifdef __ARCH_WANT_UNLOCKED_CTXSW |
2823 | /* In this case, finish_task_switch does not reenable preemption */ | |
2824 | preempt_enable(); | |
2825 | #endif | |
1da177e4 | 2826 | if (current->set_child_tid) |
b488893a | 2827 | put_user(task_pid_vnr(current), current->set_child_tid); |
1da177e4 LT |
2828 | } |
2829 | ||
2830 | /* | |
2831 | * context_switch - switch to the new MM and the new | |
2832 | * thread's register state. | |
2833 | */ | |
dd41f596 | 2834 | static inline void |
70b97a7f | 2835 | context_switch(struct rq *rq, struct task_struct *prev, |
36c8b586 | 2836 | struct task_struct *next) |
1da177e4 | 2837 | { |
dd41f596 | 2838 | struct mm_struct *mm, *oldmm; |
1da177e4 | 2839 | |
e107be36 | 2840 | prepare_task_switch(rq, prev, next); |
27a9da65 | 2841 | trace_sched_switch(prev, next); |
dd41f596 IM |
2842 | mm = next->mm; |
2843 | oldmm = prev->active_mm; | |
9226d125 ZA |
2844 | /* |
2845 | * For paravirt, this is coupled with an exit in switch_to to | |
2846 | * combine the page table reload and the switch backend into | |
2847 | * one hypercall. | |
2848 | */ | |
224101ed | 2849 | arch_start_context_switch(prev); |
9226d125 | 2850 | |
710390d9 | 2851 | if (likely(!mm)) { |
1da177e4 LT |
2852 | next->active_mm = oldmm; |
2853 | atomic_inc(&oldmm->mm_count); | |
2854 | enter_lazy_tlb(oldmm, next); | |
2855 | } else | |
2856 | switch_mm(oldmm, mm, next); | |
2857 | ||
710390d9 | 2858 | if (likely(!prev->mm)) { |
1da177e4 | 2859 | prev->active_mm = NULL; |
1da177e4 LT |
2860 | rq->prev_mm = oldmm; |
2861 | } | |
3a5f5e48 IM |
2862 | /* |
2863 | * Since the runqueue lock will be released by the next | |
2864 | * task (which is an invalid locking op but in the case | |
2865 | * of the scheduler it's an obvious special-case), so we | |
2866 | * do an early lockdep release here: | |
2867 | */ | |
2868 | #ifndef __ARCH_WANT_UNLOCKED_CTXSW | |
8a25d5de | 2869 | spin_release(&rq->lock.dep_map, 1, _THIS_IP_); |
3a5f5e48 | 2870 | #endif |
1da177e4 LT |
2871 | |
2872 | /* Here we just switch the register state and the stack. */ | |
2873 | switch_to(prev, next, prev); | |
2874 | ||
dd41f596 IM |
2875 | barrier(); |
2876 | /* | |
2877 | * this_rq must be evaluated again because prev may have moved | |
2878 | * CPUs since it called schedule(), thus the 'rq' on its stack | |
2879 | * frame will be invalid. | |
2880 | */ | |
2881 | finish_task_switch(this_rq(), prev); | |
1da177e4 LT |
2882 | } |
2883 | ||
2884 | /* | |
2885 | * nr_running, nr_uninterruptible and nr_context_switches: | |
2886 | * | |
2887 | * externally visible scheduler statistics: current number of runnable | |
2888 | * threads, current number of uninterruptible-sleeping threads, total | |
2889 | * number of context switches performed since bootup. | |
2890 | */ | |
2891 | unsigned long nr_running(void) | |
2892 | { | |
2893 | unsigned long i, sum = 0; | |
2894 | ||
2895 | for_each_online_cpu(i) | |
2896 | sum += cpu_rq(i)->nr_running; | |
2897 | ||
2898 | return sum; | |
f711f609 | 2899 | } |
1da177e4 LT |
2900 | |
2901 | unsigned long nr_uninterruptible(void) | |
f711f609 | 2902 | { |
1da177e4 | 2903 | unsigned long i, sum = 0; |
f711f609 | 2904 | |
0a945022 | 2905 | for_each_possible_cpu(i) |
1da177e4 | 2906 | sum += cpu_rq(i)->nr_uninterruptible; |
f711f609 GS |
2907 | |
2908 | /* | |
1da177e4 LT |
2909 | * Since we read the counters lockless, it might be slightly |
2910 | * inaccurate. Do not allow it to go below zero though: | |
f711f609 | 2911 | */ |
1da177e4 LT |
2912 | if (unlikely((long)sum < 0)) |
2913 | sum = 0; | |
f711f609 | 2914 | |
1da177e4 | 2915 | return sum; |
f711f609 | 2916 | } |
f711f609 | 2917 | |
1da177e4 | 2918 | unsigned long long nr_context_switches(void) |
46cb4b7c | 2919 | { |
cc94abfc SR |
2920 | int i; |
2921 | unsigned long long sum = 0; | |
46cb4b7c | 2922 | |
0a945022 | 2923 | for_each_possible_cpu(i) |
1da177e4 | 2924 | sum += cpu_rq(i)->nr_switches; |
46cb4b7c | 2925 | |
1da177e4 LT |
2926 | return sum; |
2927 | } | |
483b4ee6 | 2928 | |
1da177e4 LT |
2929 | unsigned long nr_iowait(void) |
2930 | { | |
2931 | unsigned long i, sum = 0; | |
483b4ee6 | 2932 | |
0a945022 | 2933 | for_each_possible_cpu(i) |
1da177e4 | 2934 | sum += atomic_read(&cpu_rq(i)->nr_iowait); |
46cb4b7c | 2935 | |
1da177e4 LT |
2936 | return sum; |
2937 | } | |
483b4ee6 | 2938 | |
8c215bd3 | 2939 | unsigned long nr_iowait_cpu(int cpu) |
69d25870 | 2940 | { |
8c215bd3 | 2941 | struct rq *this = cpu_rq(cpu); |
69d25870 AV |
2942 | return atomic_read(&this->nr_iowait); |
2943 | } | |
46cb4b7c | 2944 | |
69d25870 AV |
2945 | unsigned long this_cpu_load(void) |
2946 | { | |
2947 | struct rq *this = this_rq(); | |
2948 | return this->cpu_load[0]; | |
2949 | } | |
e790fb0b | 2950 | |
46cb4b7c | 2951 | |
dce48a84 TG |
2952 | /* Variables and functions for calc_load */ |
2953 | static atomic_long_t calc_load_tasks; | |
2954 | static unsigned long calc_load_update; | |
2955 | unsigned long avenrun[3]; | |
2956 | EXPORT_SYMBOL(avenrun); | |
46cb4b7c | 2957 | |
74f5187a PZ |
2958 | static long calc_load_fold_active(struct rq *this_rq) |
2959 | { | |
2960 | long nr_active, delta = 0; | |
2961 | ||
2962 | nr_active = this_rq->nr_running; | |
2963 | nr_active += (long) this_rq->nr_uninterruptible; | |
2964 | ||
2965 | if (nr_active != this_rq->calc_load_active) { | |
2966 | delta = nr_active - this_rq->calc_load_active; | |
2967 | this_rq->calc_load_active = nr_active; | |
2968 | } | |
2969 | ||
2970 | return delta; | |
2971 | } | |
2972 | ||
2973 | #ifdef CONFIG_NO_HZ | |
2974 | /* | |
2975 | * For NO_HZ we delay the active fold to the next LOAD_FREQ update. | |
2976 | * | |
2977 | * When making the ILB scale, we should try to pull this in as well. | |
2978 | */ | |
2979 | static atomic_long_t calc_load_tasks_idle; | |
2980 | ||
2981 | static void calc_load_account_idle(struct rq *this_rq) | |
2982 | { | |
2983 | long delta; | |
2984 | ||
2985 | delta = calc_load_fold_active(this_rq); | |
2986 | if (delta) | |
2987 | atomic_long_add(delta, &calc_load_tasks_idle); | |
2988 | } | |
2989 | ||
2990 | static long calc_load_fold_idle(void) | |
2991 | { | |
2992 | long delta = 0; | |
2993 | ||
2994 | /* | |
2995 | * Its got a race, we don't care... | |
2996 | */ | |
2997 | if (atomic_long_read(&calc_load_tasks_idle)) | |
2998 | delta = atomic_long_xchg(&calc_load_tasks_idle, 0); | |
2999 | ||
3000 | return delta; | |
3001 | } | |
3002 | #else | |
3003 | static void calc_load_account_idle(struct rq *this_rq) | |
3004 | { | |
3005 | } | |
3006 | ||
3007 | static inline long calc_load_fold_idle(void) | |
3008 | { | |
3009 | return 0; | |
3010 | } | |
3011 | #endif | |
3012 | ||
2d02494f TG |
3013 | /** |
3014 | * get_avenrun - get the load average array | |
3015 | * @loads: pointer to dest load array | |
3016 | * @offset: offset to add | |
3017 | * @shift: shift count to shift the result left | |
3018 | * | |
3019 | * These values are estimates at best, so no need for locking. | |
3020 | */ | |
3021 | void get_avenrun(unsigned long *loads, unsigned long offset, int shift) | |
3022 | { | |
3023 | loads[0] = (avenrun[0] + offset) << shift; | |
3024 | loads[1] = (avenrun[1] + offset) << shift; | |
3025 | loads[2] = (avenrun[2] + offset) << shift; | |
46cb4b7c | 3026 | } |
46cb4b7c | 3027 | |
dce48a84 TG |
3028 | static unsigned long |
3029 | calc_load(unsigned long load, unsigned long exp, unsigned long active) | |
db1b1fef | 3030 | { |
dce48a84 TG |
3031 | load *= exp; |
3032 | load += active * (FIXED_1 - exp); | |
3033 | return load >> FSHIFT; | |
3034 | } | |
46cb4b7c SS |
3035 | |
3036 | /* | |
dce48a84 TG |
3037 | * calc_load - update the avenrun load estimates 10 ticks after the |
3038 | * CPUs have updated calc_load_tasks. | |
7835b98b | 3039 | */ |
dce48a84 | 3040 | void calc_global_load(void) |
7835b98b | 3041 | { |
dce48a84 TG |
3042 | unsigned long upd = calc_load_update + 10; |
3043 | long active; | |
1da177e4 | 3044 | |
dce48a84 TG |
3045 | if (time_before(jiffies, upd)) |
3046 | return; | |
1da177e4 | 3047 | |
dce48a84 TG |
3048 | active = atomic_long_read(&calc_load_tasks); |
3049 | active = active > 0 ? active * FIXED_1 : 0; | |
1da177e4 | 3050 | |
dce48a84 TG |
3051 | avenrun[0] = calc_load(avenrun[0], EXP_1, active); |
3052 | avenrun[1] = calc_load(avenrun[1], EXP_5, active); | |
3053 | avenrun[2] = calc_load(avenrun[2], EXP_15, active); | |
dd41f596 | 3054 | |
dce48a84 TG |
3055 | calc_load_update += LOAD_FREQ; |
3056 | } | |
1da177e4 | 3057 | |
dce48a84 | 3058 | /* |
74f5187a PZ |
3059 | * Called from update_cpu_load() to periodically update this CPU's |
3060 | * active count. | |
dce48a84 TG |
3061 | */ |
3062 | static void calc_load_account_active(struct rq *this_rq) | |
3063 | { | |
74f5187a | 3064 | long delta; |
08c183f3 | 3065 | |
74f5187a PZ |
3066 | if (time_before(jiffies, this_rq->calc_load_update)) |
3067 | return; | |
783609c6 | 3068 | |
74f5187a PZ |
3069 | delta = calc_load_fold_active(this_rq); |
3070 | delta += calc_load_fold_idle(); | |
3071 | if (delta) | |
dce48a84 | 3072 | atomic_long_add(delta, &calc_load_tasks); |
74f5187a PZ |
3073 | |
3074 | this_rq->calc_load_update += LOAD_FREQ; | |
46cb4b7c SS |
3075 | } |
3076 | ||
fdf3e95d VP |
3077 | /* |
3078 | * The exact cpuload at various idx values, calculated at every tick would be | |
3079 | * load = (2^idx - 1) / 2^idx * load + 1 / 2^idx * cur_load | |
3080 | * | |
3081 | * If a cpu misses updates for n-1 ticks (as it was idle) and update gets called | |
3082 | * on nth tick when cpu may be busy, then we have: | |
3083 | * load = ((2^idx - 1) / 2^idx)^(n-1) * load | |
3084 | * load = (2^idx - 1) / 2^idx) * load + 1 / 2^idx * cur_load | |
3085 | * | |
3086 | * decay_load_missed() below does efficient calculation of | |
3087 | * load = ((2^idx - 1) / 2^idx)^(n-1) * load | |
3088 | * avoiding 0..n-1 loop doing load = ((2^idx - 1) / 2^idx) * load | |
3089 | * | |
3090 | * The calculation is approximated on a 128 point scale. | |
3091 | * degrade_zero_ticks is the number of ticks after which load at any | |
3092 | * particular idx is approximated to be zero. | |
3093 | * degrade_factor is a precomputed table, a row for each load idx. | |
3094 | * Each column corresponds to degradation factor for a power of two ticks, | |
3095 | * based on 128 point scale. | |
3096 | * Example: | |
3097 | * row 2, col 3 (=12) says that the degradation at load idx 2 after | |
3098 | * 8 ticks is 12/128 (which is an approximation of exact factor 3^8/4^8). | |
3099 | * | |
3100 | * With this power of 2 load factors, we can degrade the load n times | |
3101 | * by looking at 1 bits in n and doing as many mult/shift instead of | |
3102 | * n mult/shifts needed by the exact degradation. | |
3103 | */ | |
3104 | #define DEGRADE_SHIFT 7 | |
3105 | static const unsigned char | |
3106 | degrade_zero_ticks[CPU_LOAD_IDX_MAX] = {0, 8, 32, 64, 128}; | |
3107 | static const unsigned char | |
3108 | degrade_factor[CPU_LOAD_IDX_MAX][DEGRADE_SHIFT + 1] = { | |
3109 | {0, 0, 0, 0, 0, 0, 0, 0}, | |
3110 | {64, 32, 8, 0, 0, 0, 0, 0}, | |
3111 | {96, 72, 40, 12, 1, 0, 0}, | |
3112 | {112, 98, 75, 43, 15, 1, 0}, | |
3113 | {120, 112, 98, 76, 45, 16, 2} }; | |
3114 | ||
3115 | /* | |
3116 | * Update cpu_load for any missed ticks, due to tickless idle. The backlog | |
3117 | * would be when CPU is idle and so we just decay the old load without | |
3118 | * adding any new load. | |
3119 | */ | |
3120 | static unsigned long | |
3121 | decay_load_missed(unsigned long load, unsigned long missed_updates, int idx) | |
3122 | { | |
3123 | int j = 0; | |
3124 | ||
3125 | if (!missed_updates) | |
3126 | return load; | |
3127 | ||
3128 | if (missed_updates >= degrade_zero_ticks[idx]) | |
3129 | return 0; | |
3130 | ||
3131 | if (idx == 1) | |
3132 | return load >> missed_updates; | |
3133 | ||
3134 | while (missed_updates) { | |
3135 | if (missed_updates % 2) | |
3136 | load = (load * degrade_factor[idx][j]) >> DEGRADE_SHIFT; | |
3137 | ||
3138 | missed_updates >>= 1; | |
3139 | j++; | |
3140 | } | |
3141 | return load; | |
3142 | } | |
3143 | ||
46cb4b7c | 3144 | /* |
dd41f596 | 3145 | * Update rq->cpu_load[] statistics. This function is usually called every |
fdf3e95d VP |
3146 | * scheduler tick (TICK_NSEC). With tickless idle this will not be called |
3147 | * every tick. We fix it up based on jiffies. | |
46cb4b7c | 3148 | */ |
dd41f596 | 3149 | static void update_cpu_load(struct rq *this_rq) |
46cb4b7c | 3150 | { |
495eca49 | 3151 | unsigned long this_load = this_rq->load.weight; |
fdf3e95d VP |
3152 | unsigned long curr_jiffies = jiffies; |
3153 | unsigned long pending_updates; | |
dd41f596 | 3154 | int i, scale; |
46cb4b7c | 3155 | |
dd41f596 | 3156 | this_rq->nr_load_updates++; |
46cb4b7c | 3157 | |
fdf3e95d VP |
3158 | /* Avoid repeated calls on same jiffy, when moving in and out of idle */ |
3159 | if (curr_jiffies == this_rq->last_load_update_tick) | |
3160 | return; | |
3161 | ||
3162 | pending_updates = curr_jiffies - this_rq->last_load_update_tick; | |
3163 | this_rq->last_load_update_tick = curr_jiffies; | |
3164 | ||
dd41f596 | 3165 | /* Update our load: */ |
fdf3e95d VP |
3166 | this_rq->cpu_load[0] = this_load; /* Fasttrack for idx 0 */ |
3167 | for (i = 1, scale = 2; i < CPU_LOAD_IDX_MAX; i++, scale += scale) { | |
dd41f596 | 3168 | unsigned long old_load, new_load; |
7d1e6a9b | 3169 | |
dd41f596 | 3170 | /* scale is effectively 1 << i now, and >> i divides by scale */ |
46cb4b7c | 3171 | |
dd41f596 | 3172 | old_load = this_rq->cpu_load[i]; |
fdf3e95d | 3173 | old_load = decay_load_missed(old_load, pending_updates - 1, i); |
dd41f596 | 3174 | new_load = this_load; |
a25707f3 IM |
3175 | /* |
3176 | * Round up the averaging division if load is increasing. This | |
3177 | * prevents us from getting stuck on 9 if the load is 10, for | |
3178 | * example. | |
3179 | */ | |
3180 | if (new_load > old_load) | |
fdf3e95d VP |
3181 | new_load += scale - 1; |
3182 | ||
3183 | this_rq->cpu_load[i] = (old_load * (scale - 1) + new_load) >> i; | |
dd41f596 | 3184 | } |
fdf3e95d VP |
3185 | } |
3186 | ||
3187 | static void update_cpu_load_active(struct rq *this_rq) | |
3188 | { | |
3189 | update_cpu_load(this_rq); | |
46cb4b7c | 3190 | |
74f5187a | 3191 | calc_load_account_active(this_rq); |
46cb4b7c SS |
3192 | } |
3193 | ||
dd41f596 | 3194 | #ifdef CONFIG_SMP |
8a0be9ef | 3195 | |
46cb4b7c | 3196 | /* |
38022906 PZ |
3197 | * sched_exec - execve() is a valuable balancing opportunity, because at |
3198 | * this point the task has the smallest effective memory and cache footprint. | |
46cb4b7c | 3199 | */ |
38022906 | 3200 | void sched_exec(void) |
46cb4b7c | 3201 | { |
38022906 | 3202 | struct task_struct *p = current; |
1da177e4 | 3203 | unsigned long flags; |
70b97a7f | 3204 | struct rq *rq; |
0017d735 | 3205 | int dest_cpu; |
46cb4b7c | 3206 | |
1da177e4 | 3207 | rq = task_rq_lock(p, &flags); |
0017d735 PZ |
3208 | dest_cpu = p->sched_class->select_task_rq(rq, p, SD_BALANCE_EXEC, 0); |
3209 | if (dest_cpu == smp_processor_id()) | |
3210 | goto unlock; | |
38022906 | 3211 | |
46cb4b7c | 3212 | /* |
38022906 | 3213 | * select_task_rq() can race against ->cpus_allowed |
46cb4b7c | 3214 | */ |
30da688e | 3215 | if (cpumask_test_cpu(dest_cpu, &p->cpus_allowed) && |
969c7921 TH |
3216 | likely(cpu_active(dest_cpu)) && migrate_task(p, dest_cpu)) { |
3217 | struct migration_arg arg = { p, dest_cpu }; | |
46cb4b7c | 3218 | |
1da177e4 | 3219 | task_rq_unlock(rq, &flags); |
969c7921 | 3220 | stop_one_cpu(cpu_of(rq), migration_cpu_stop, &arg); |
1da177e4 LT |
3221 | return; |
3222 | } | |
0017d735 | 3223 | unlock: |
1da177e4 | 3224 | task_rq_unlock(rq, &flags); |
1da177e4 | 3225 | } |
dd41f596 | 3226 | |
1da177e4 LT |
3227 | #endif |
3228 | ||
1da177e4 LT |
3229 | DEFINE_PER_CPU(struct kernel_stat, kstat); |
3230 | ||
3231 | EXPORT_PER_CPU_SYMBOL(kstat); | |
3232 | ||
3233 | /* | |
c5f8d995 | 3234 | * Return any ns on the sched_clock that have not yet been accounted in |
f06febc9 | 3235 | * @p in case that task is currently running. |
c5f8d995 HS |
3236 | * |
3237 | * Called with task_rq_lock() held on @rq. | |
1da177e4 | 3238 | */ |
c5f8d995 HS |
3239 | static u64 do_task_delta_exec(struct task_struct *p, struct rq *rq) |
3240 | { | |
3241 | u64 ns = 0; | |
3242 | ||
3243 | if (task_current(rq, p)) { | |
3244 | update_rq_clock(rq); | |
3245 | ns = rq->clock - p->se.exec_start; | |
3246 | if ((s64)ns < 0) | |
3247 | ns = 0; | |
3248 | } | |
3249 | ||
3250 | return ns; | |
3251 | } | |
3252 | ||
bb34d92f | 3253 | unsigned long long task_delta_exec(struct task_struct *p) |
1da177e4 | 3254 | { |
1da177e4 | 3255 | unsigned long flags; |
41b86e9c | 3256 | struct rq *rq; |
bb34d92f | 3257 | u64 ns = 0; |
48f24c4d | 3258 | |
41b86e9c | 3259 | rq = task_rq_lock(p, &flags); |
c5f8d995 HS |
3260 | ns = do_task_delta_exec(p, rq); |
3261 | task_rq_unlock(rq, &flags); | |
1508487e | 3262 | |
c5f8d995 HS |
3263 | return ns; |
3264 | } | |
f06febc9 | 3265 | |
c5f8d995 HS |
3266 | /* |
3267 | * Return accounted runtime for the task. | |
3268 | * In case the task is currently running, return the runtime plus current's | |
3269 | * pending runtime that have not been accounted yet. | |
3270 | */ | |
3271 | unsigned long long task_sched_runtime(struct task_struct *p) | |
3272 | { | |
3273 | unsigned long flags; | |
3274 | struct rq *rq; | |
3275 | u64 ns = 0; | |
3276 | ||
3277 | rq = task_rq_lock(p, &flags); | |
3278 | ns = p->se.sum_exec_runtime + do_task_delta_exec(p, rq); | |
3279 | task_rq_unlock(rq, &flags); | |
3280 | ||
3281 | return ns; | |
3282 | } | |
48f24c4d | 3283 | |
c5f8d995 HS |
3284 | /* |
3285 | * Return sum_exec_runtime for the thread group. | |
3286 | * In case the task is currently running, return the sum plus current's | |
3287 | * pending runtime that have not been accounted yet. | |
3288 | * | |
3289 | * Note that the thread group might have other running tasks as well, | |
3290 | * so the return value not includes other pending runtime that other | |
3291 | * running tasks might have. | |
3292 | */ | |
3293 | unsigned long long thread_group_sched_runtime(struct task_struct *p) | |
3294 | { | |
3295 | struct task_cputime totals; | |
3296 | unsigned long flags; | |
3297 | struct rq *rq; | |
3298 | u64 ns; | |
3299 | ||
3300 | rq = task_rq_lock(p, &flags); | |
3301 | thread_group_cputime(p, &totals); | |
3302 | ns = totals.sum_exec_runtime + do_task_delta_exec(p, rq); | |
41b86e9c | 3303 | task_rq_unlock(rq, &flags); |
48f24c4d | 3304 | |
1da177e4 LT |
3305 | return ns; |
3306 | } | |
3307 | ||
1da177e4 LT |
3308 | /* |
3309 | * Account user cpu time to a process. | |
3310 | * @p: the process that the cpu time gets accounted to | |
1da177e4 | 3311 | * @cputime: the cpu time spent in user space since the last update |
457533a7 | 3312 | * @cputime_scaled: cputime scaled by cpu frequency |
1da177e4 | 3313 | */ |
457533a7 MS |
3314 | void account_user_time(struct task_struct *p, cputime_t cputime, |
3315 | cputime_t cputime_scaled) | |
1da177e4 LT |
3316 | { |
3317 | struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat; | |
3318 | cputime64_t tmp; | |
3319 | ||
457533a7 | 3320 | /* Add user time to process. */ |
1da177e4 | 3321 | p->utime = cputime_add(p->utime, cputime); |
457533a7 | 3322 | p->utimescaled = cputime_add(p->utimescaled, cputime_scaled); |
f06febc9 | 3323 | account_group_user_time(p, cputime); |
1da177e4 LT |
3324 | |
3325 | /* Add user time to cpustat. */ | |
3326 | tmp = cputime_to_cputime64(cputime); | |
3327 | if (TASK_NICE(p) > 0) | |
3328 | cpustat->nice = cputime64_add(cpustat->nice, tmp); | |
3329 | else | |
3330 | cpustat->user = cputime64_add(cpustat->user, tmp); | |
ef12fefa BR |
3331 | |
3332 | cpuacct_update_stats(p, CPUACCT_STAT_USER, cputime); | |
49b5cf34 JL |
3333 | /* Account for user time used */ |
3334 | acct_update_integrals(p); | |
1da177e4 LT |
3335 | } |
3336 | ||
94886b84 LV |
3337 | /* |
3338 | * Account guest cpu time to a process. | |
3339 | * @p: the process that the cpu time gets accounted to | |
3340 | * @cputime: the cpu time spent in virtual machine since the last update | |
457533a7 | 3341 | * @cputime_scaled: cputime scaled by cpu frequency |
94886b84 | 3342 | */ |
457533a7 MS |
3343 | static void account_guest_time(struct task_struct *p, cputime_t cputime, |
3344 | cputime_t cputime_scaled) | |
94886b84 LV |
3345 | { |
3346 | cputime64_t tmp; | |
3347 | struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat; | |
3348 | ||
3349 | tmp = cputime_to_cputime64(cputime); | |
3350 | ||
457533a7 | 3351 | /* Add guest time to process. */ |
94886b84 | 3352 | p->utime = cputime_add(p->utime, cputime); |
457533a7 | 3353 | p->utimescaled = cputime_add(p->utimescaled, cputime_scaled); |
f06febc9 | 3354 | account_group_user_time(p, cputime); |
94886b84 LV |
3355 | p->gtime = cputime_add(p->gtime, cputime); |
3356 | ||
457533a7 | 3357 | /* Add guest time to cpustat. */ |
ce0e7b28 RO |
3358 | if (TASK_NICE(p) > 0) { |
3359 | cpustat->nice = cputime64_add(cpustat->nice, tmp); | |
3360 | cpustat->guest_nice = cputime64_add(cpustat->guest_nice, tmp); | |
3361 | } else { | |
3362 | cpustat->user = cputime64_add(cpustat->user, tmp); | |
3363 | cpustat->guest = cputime64_add(cpustat->guest, tmp); | |
3364 | } | |
94886b84 LV |
3365 | } |
3366 | ||
1da177e4 LT |
3367 | /* |
3368 | * Account system cpu time to a process. | |
3369 | * @p: the process that the cpu time gets accounted to | |
3370 | * @hardirq_offset: the offset to subtract from hardirq_count() | |
3371 | * @cputime: the cpu time spent in kernel space since the last update | |
457533a7 | 3372 | * @cputime_scaled: cputime scaled by cpu frequency |
1da177e4 LT |
3373 | */ |
3374 | void account_system_time(struct task_struct *p, int hardirq_offset, | |
457533a7 | 3375 | cputime_t cputime, cputime_t cputime_scaled) |
1da177e4 LT |
3376 | { |
3377 | struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat; | |
1da177e4 LT |
3378 | cputime64_t tmp; |
3379 | ||
983ed7a6 | 3380 | if ((p->flags & PF_VCPU) && (irq_count() - hardirq_offset == 0)) { |
457533a7 | 3381 | account_guest_time(p, cputime, cputime_scaled); |
983ed7a6 HH |
3382 | return; |
3383 | } | |
94886b84 | 3384 | |
457533a7 | 3385 | /* Add system time to process. */ |
1da177e4 | 3386 | p->stime = cputime_add(p->stime, cputime); |
457533a7 | 3387 | p->stimescaled = cputime_add(p->stimescaled, cputime_scaled); |
f06febc9 | 3388 | account_group_system_time(p, cputime); |
1da177e4 LT |
3389 | |
3390 | /* Add system time to cpustat. */ | |
3391 | tmp = cputime_to_cputime64(cputime); | |
3392 | if (hardirq_count() - hardirq_offset) | |
3393 | cpustat->irq = cputime64_add(cpustat->irq, tmp); | |
3394 | else if (softirq_count()) | |
3395 | cpustat->softirq = cputime64_add(cpustat->softirq, tmp); | |
1da177e4 | 3396 | else |
79741dd3 MS |
3397 | cpustat->system = cputime64_add(cpustat->system, tmp); |
3398 | ||
ef12fefa BR |
3399 | cpuacct_update_stats(p, CPUACCT_STAT_SYSTEM, cputime); |
3400 | ||
1da177e4 LT |
3401 | /* Account for system time used */ |
3402 | acct_update_integrals(p); | |
1da177e4 LT |
3403 | } |
3404 | ||
c66f08be | 3405 | /* |
1da177e4 | 3406 | * Account for involuntary wait time. |
1da177e4 | 3407 | * @steal: the cpu time spent in involuntary wait |
c66f08be | 3408 | */ |
79741dd3 | 3409 | void account_steal_time(cputime_t cputime) |
c66f08be | 3410 | { |
79741dd3 MS |
3411 | struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat; |
3412 | cputime64_t cputime64 = cputime_to_cputime64(cputime); | |
3413 | ||
3414 | cpustat->steal = cputime64_add(cpustat->steal, cputime64); | |
c66f08be MN |
3415 | } |
3416 | ||
1da177e4 | 3417 | /* |
79741dd3 MS |
3418 | * Account for idle time. |
3419 | * @cputime: the cpu time spent in idle wait | |
1da177e4 | 3420 | */ |
79741dd3 | 3421 | void account_idle_time(cputime_t cputime) |
1da177e4 LT |
3422 | { |
3423 | struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat; | |
79741dd3 | 3424 | cputime64_t cputime64 = cputime_to_cputime64(cputime); |
70b97a7f | 3425 | struct rq *rq = this_rq(); |
1da177e4 | 3426 | |
79741dd3 MS |
3427 | if (atomic_read(&rq->nr_iowait) > 0) |
3428 | cpustat->iowait = cputime64_add(cpustat->iowait, cputime64); | |
3429 | else | |
3430 | cpustat->idle = cputime64_add(cpustat->idle, cputime64); | |
1da177e4 LT |
3431 | } |
3432 | ||
79741dd3 MS |
3433 | #ifndef CONFIG_VIRT_CPU_ACCOUNTING |
3434 | ||
3435 | /* | |
3436 | * Account a single tick of cpu time. | |
3437 | * @p: the process that the cpu time gets accounted to | |
3438 | * @user_tick: indicates if the tick is a user or a system tick | |
3439 | */ | |
3440 | void account_process_tick(struct task_struct *p, int user_tick) | |
3441 | { | |
a42548a1 | 3442 | cputime_t one_jiffy_scaled = cputime_to_scaled(cputime_one_jiffy); |
79741dd3 MS |
3443 | struct rq *rq = this_rq(); |
3444 | ||
3445 | if (user_tick) | |
a42548a1 | 3446 | account_user_time(p, cputime_one_jiffy, one_jiffy_scaled); |
f5f293a4 | 3447 | else if ((p != rq->idle) || (irq_count() != HARDIRQ_OFFSET)) |
a42548a1 | 3448 | account_system_time(p, HARDIRQ_OFFSET, cputime_one_jiffy, |
79741dd3 MS |
3449 | one_jiffy_scaled); |
3450 | else | |
a42548a1 | 3451 | account_idle_time(cputime_one_jiffy); |
79741dd3 MS |
3452 | } |
3453 | ||
3454 | /* | |
3455 | * Account multiple ticks of steal time. | |
3456 | * @p: the process from which the cpu time has been stolen | |
3457 | * @ticks: number of stolen ticks | |
3458 | */ | |
3459 | void account_steal_ticks(unsigned long ticks) | |
3460 | { | |
3461 | account_steal_time(jiffies_to_cputime(ticks)); | |
3462 | } | |
3463 | ||
3464 | /* | |
3465 | * Account multiple ticks of idle time. | |
3466 | * @ticks: number of stolen ticks | |
3467 | */ | |
3468 | void account_idle_ticks(unsigned long ticks) | |
3469 | { | |
3470 | account_idle_time(jiffies_to_cputime(ticks)); | |
1da177e4 LT |
3471 | } |
3472 | ||
79741dd3 MS |
3473 | #endif |
3474 | ||
49048622 BS |
3475 | /* |
3476 | * Use precise platform statistics if available: | |
3477 | */ | |
3478 | #ifdef CONFIG_VIRT_CPU_ACCOUNTING | |
d180c5bc | 3479 | void task_times(struct task_struct *p, cputime_t *ut, cputime_t *st) |
49048622 | 3480 | { |
d99ca3b9 HS |
3481 | *ut = p->utime; |
3482 | *st = p->stime; | |
49048622 BS |
3483 | } |
3484 | ||
0cf55e1e | 3485 | void thread_group_times(struct task_struct *p, cputime_t *ut, cputime_t *st) |
49048622 | 3486 | { |
0cf55e1e HS |
3487 | struct task_cputime cputime; |
3488 | ||
3489 | thread_group_cputime(p, &cputime); | |
3490 | ||
3491 | *ut = cputime.utime; | |
3492 | *st = cputime.stime; | |
49048622 BS |
3493 | } |
3494 | #else | |
761b1d26 HS |
3495 | |
3496 | #ifndef nsecs_to_cputime | |
b7b20df9 | 3497 | # define nsecs_to_cputime(__nsecs) nsecs_to_jiffies(__nsecs) |
761b1d26 HS |
3498 | #endif |
3499 | ||
d180c5bc | 3500 | void task_times(struct task_struct *p, cputime_t *ut, cputime_t *st) |
49048622 | 3501 | { |
d99ca3b9 | 3502 | cputime_t rtime, utime = p->utime, total = cputime_add(utime, p->stime); |
49048622 BS |
3503 | |
3504 | /* | |
3505 | * Use CFS's precise accounting: | |
3506 | */ | |
d180c5bc | 3507 | rtime = nsecs_to_cputime(p->se.sum_exec_runtime); |
49048622 BS |
3508 | |
3509 | if (total) { | |
d180c5bc HS |
3510 | u64 temp; |
3511 | ||
3512 | temp = (u64)(rtime * utime); | |
49048622 | 3513 | do_div(temp, total); |
d180c5bc HS |
3514 | utime = (cputime_t)temp; |
3515 | } else | |
3516 | utime = rtime; | |
49048622 | 3517 | |
d180c5bc HS |
3518 | /* |
3519 | * Compare with previous values, to keep monotonicity: | |
3520 | */ | |
761b1d26 | 3521 | p->prev_utime = max(p->prev_utime, utime); |
d99ca3b9 | 3522 | p->prev_stime = max(p->prev_stime, cputime_sub(rtime, p->prev_utime)); |
49048622 | 3523 | |
d99ca3b9 HS |
3524 | *ut = p->prev_utime; |
3525 | *st = p->prev_stime; | |
49048622 BS |
3526 | } |
3527 | ||
0cf55e1e HS |
3528 | /* |
3529 | * Must be called with siglock held. | |
3530 | */ | |
3531 | void thread_group_times(struct task_struct *p, cputime_t *ut, cputime_t *st) | |
49048622 | 3532 | { |
0cf55e1e HS |
3533 | struct signal_struct *sig = p->signal; |
3534 | struct task_cputime cputime; | |
3535 | cputime_t rtime, utime, total; | |
49048622 | 3536 | |
0cf55e1e | 3537 | thread_group_cputime(p, &cputime); |
49048622 | 3538 | |
0cf55e1e HS |
3539 | total = cputime_add(cputime.utime, cputime.stime); |
3540 | rtime = nsecs_to_cputime(cputime.sum_exec_runtime); | |
49048622 | 3541 | |
0cf55e1e HS |
3542 | if (total) { |
3543 | u64 temp; | |
49048622 | 3544 | |
0cf55e1e HS |
3545 | temp = (u64)(rtime * cputime.utime); |
3546 | do_div(temp, total); | |
3547 | utime = (cputime_t)temp; | |
3548 | } else | |
3549 | utime = rtime; | |
3550 | ||
3551 | sig->prev_utime = max(sig->prev_utime, utime); | |
3552 | sig->prev_stime = max(sig->prev_stime, | |
3553 | cputime_sub(rtime, sig->prev_utime)); | |
3554 | ||
3555 | *ut = sig->prev_utime; | |
3556 | *st = sig->prev_stime; | |
49048622 | 3557 | } |
49048622 | 3558 | #endif |
49048622 | 3559 | |
7835b98b CL |
3560 | /* |
3561 | * This function gets called by the timer code, with HZ frequency. | |
3562 | * We call it with interrupts disabled. | |
3563 | * | |
3564 | * It also gets called by the fork code, when changing the parent's | |
3565 | * timeslices. | |
3566 | */ | |
3567 | void scheduler_tick(void) | |
3568 | { | |
7835b98b CL |
3569 | int cpu = smp_processor_id(); |
3570 | struct rq *rq = cpu_rq(cpu); | |
dd41f596 | 3571 | struct task_struct *curr = rq->curr; |
3e51f33f PZ |
3572 | |
3573 | sched_clock_tick(); | |
dd41f596 | 3574 | |
05fa785c | 3575 | raw_spin_lock(&rq->lock); |
3e51f33f | 3576 | update_rq_clock(rq); |
fdf3e95d | 3577 | update_cpu_load_active(rq); |
fa85ae24 | 3578 | curr->sched_class->task_tick(rq, curr, 0); |
05fa785c | 3579 | raw_spin_unlock(&rq->lock); |
7835b98b | 3580 | |
49f47433 | 3581 | perf_event_task_tick(curr); |
e220d2dc | 3582 | |
e418e1c2 | 3583 | #ifdef CONFIG_SMP |
dd41f596 IM |
3584 | rq->idle_at_tick = idle_cpu(cpu); |
3585 | trigger_load_balance(rq, cpu); | |
e418e1c2 | 3586 | #endif |
1da177e4 LT |
3587 | } |
3588 | ||
132380a0 | 3589 | notrace unsigned long get_parent_ip(unsigned long addr) |
6cd8a4bb SR |
3590 | { |
3591 | if (in_lock_functions(addr)) { | |
3592 | addr = CALLER_ADDR2; | |
3593 | if (in_lock_functions(addr)) | |
3594 | addr = CALLER_ADDR3; | |
3595 | } | |
3596 | return addr; | |
3597 | } | |
1da177e4 | 3598 | |
7e49fcce SR |
3599 | #if defined(CONFIG_PREEMPT) && (defined(CONFIG_DEBUG_PREEMPT) || \ |
3600 | defined(CONFIG_PREEMPT_TRACER)) | |
3601 | ||
43627582 | 3602 | void __kprobes add_preempt_count(int val) |
1da177e4 | 3603 | { |
6cd8a4bb | 3604 | #ifdef CONFIG_DEBUG_PREEMPT |
1da177e4 LT |
3605 | /* |
3606 | * Underflow? | |
3607 | */ | |
9a11b49a IM |
3608 | if (DEBUG_LOCKS_WARN_ON((preempt_count() < 0))) |
3609 | return; | |
6cd8a4bb | 3610 | #endif |
1da177e4 | 3611 | preempt_count() += val; |
6cd8a4bb | 3612 | #ifdef CONFIG_DEBUG_PREEMPT |
1da177e4 LT |
3613 | /* |
3614 | * Spinlock count overflowing soon? | |
3615 | */ | |
33859f7f MOS |
3616 | DEBUG_LOCKS_WARN_ON((preempt_count() & PREEMPT_MASK) >= |
3617 | PREEMPT_MASK - 10); | |
6cd8a4bb SR |
3618 | #endif |
3619 | if (preempt_count() == val) | |
3620 | trace_preempt_off(CALLER_ADDR0, get_parent_ip(CALLER_ADDR1)); | |
1da177e4 LT |
3621 | } |
3622 | EXPORT_SYMBOL(add_preempt_count); | |
3623 | ||
43627582 | 3624 | void __kprobes sub_preempt_count(int val) |
1da177e4 | 3625 | { |
6cd8a4bb | 3626 | #ifdef CONFIG_DEBUG_PREEMPT |
1da177e4 LT |
3627 | /* |
3628 | * Underflow? | |
3629 | */ | |
01e3eb82 | 3630 | if (DEBUG_LOCKS_WARN_ON(val > preempt_count())) |
9a11b49a | 3631 | return; |
1da177e4 LT |
3632 | /* |
3633 | * Is the spinlock portion underflowing? | |
3634 | */ | |
9a11b49a IM |
3635 | if (DEBUG_LOCKS_WARN_ON((val < PREEMPT_MASK) && |
3636 | !(preempt_count() & PREEMPT_MASK))) | |
3637 | return; | |
6cd8a4bb | 3638 | #endif |
9a11b49a | 3639 | |
6cd8a4bb SR |
3640 | if (preempt_count() == val) |
3641 | trace_preempt_on(CALLER_ADDR0, get_parent_ip(CALLER_ADDR1)); | |
1da177e4 LT |
3642 | preempt_count() -= val; |
3643 | } | |
3644 | EXPORT_SYMBOL(sub_preempt_count); | |
3645 | ||
3646 | #endif | |
3647 | ||
3648 | /* | |
dd41f596 | 3649 | * Print scheduling while atomic bug: |
1da177e4 | 3650 | */ |
dd41f596 | 3651 | static noinline void __schedule_bug(struct task_struct *prev) |
1da177e4 | 3652 | { |
838225b4 SS |
3653 | struct pt_regs *regs = get_irq_regs(); |
3654 | ||
3df0fc5b PZ |
3655 | printk(KERN_ERR "BUG: scheduling while atomic: %s/%d/0x%08x\n", |
3656 | prev->comm, prev->pid, preempt_count()); | |
838225b4 | 3657 | |
dd41f596 | 3658 | debug_show_held_locks(prev); |
e21f5b15 | 3659 | print_modules(); |
dd41f596 IM |
3660 | if (irqs_disabled()) |
3661 | print_irqtrace_events(prev); | |
838225b4 SS |
3662 | |
3663 | if (regs) | |
3664 | show_regs(regs); | |
3665 | else | |
3666 | dump_stack(); | |
dd41f596 | 3667 | } |
1da177e4 | 3668 | |
dd41f596 IM |
3669 | /* |
3670 | * Various schedule()-time debugging checks and statistics: | |
3671 | */ | |
3672 | static inline void schedule_debug(struct task_struct *prev) | |
3673 | { | |
1da177e4 | 3674 | /* |
41a2d6cf | 3675 | * Test if we are atomic. Since do_exit() needs to call into |
1da177e4 LT |
3676 | * schedule() atomically, we ignore that path for now. |
3677 | * Otherwise, whine if we are scheduling when we should not be. | |
3678 | */ | |
3f33a7ce | 3679 | if (unlikely(in_atomic_preempt_off() && !prev->exit_state)) |
dd41f596 IM |
3680 | __schedule_bug(prev); |
3681 | ||
1da177e4 LT |
3682 | profile_hit(SCHED_PROFILING, __builtin_return_address(0)); |
3683 | ||
2d72376b | 3684 | schedstat_inc(this_rq(), sched_count); |
b8efb561 IM |
3685 | #ifdef CONFIG_SCHEDSTATS |
3686 | if (unlikely(prev->lock_depth >= 0)) { | |
2d72376b IM |
3687 | schedstat_inc(this_rq(), bkl_count); |
3688 | schedstat_inc(prev, sched_info.bkl_count); | |
b8efb561 IM |
3689 | } |
3690 | #endif | |
dd41f596 IM |
3691 | } |
3692 | ||
6cecd084 | 3693 | static void put_prev_task(struct rq *rq, struct task_struct *prev) |
df1c99d4 | 3694 | { |
a64692a3 MG |
3695 | if (prev->se.on_rq) |
3696 | update_rq_clock(rq); | |
3697 | rq->skip_clock_update = 0; | |
6cecd084 | 3698 | prev->sched_class->put_prev_task(rq, prev); |
df1c99d4 MG |
3699 | } |
3700 | ||
dd41f596 IM |
3701 | /* |
3702 | * Pick up the highest-prio task: | |
3703 | */ | |
3704 | static inline struct task_struct * | |
b67802ea | 3705 | pick_next_task(struct rq *rq) |
dd41f596 | 3706 | { |
5522d5d5 | 3707 | const struct sched_class *class; |
dd41f596 | 3708 | struct task_struct *p; |
1da177e4 LT |
3709 | |
3710 | /* | |
dd41f596 IM |
3711 | * Optimization: we know that if all tasks are in |
3712 | * the fair class we can call that function directly: | |
1da177e4 | 3713 | */ |
dd41f596 | 3714 | if (likely(rq->nr_running == rq->cfs.nr_running)) { |
fb8d4724 | 3715 | p = fair_sched_class.pick_next_task(rq); |
dd41f596 IM |
3716 | if (likely(p)) |
3717 | return p; | |
1da177e4 LT |
3718 | } |
3719 | ||
dd41f596 IM |
3720 | class = sched_class_highest; |
3721 | for ( ; ; ) { | |
fb8d4724 | 3722 | p = class->pick_next_task(rq); |
dd41f596 IM |
3723 | if (p) |
3724 | return p; | |
3725 | /* | |
3726 | * Will never be NULL as the idle class always | |
3727 | * returns a non-NULL p: | |
3728 | */ | |
3729 | class = class->next; | |
3730 | } | |
3731 | } | |
1da177e4 | 3732 | |
dd41f596 IM |
3733 | /* |
3734 | * schedule() is the main scheduler function. | |
3735 | */ | |
ff743345 | 3736 | asmlinkage void __sched schedule(void) |
dd41f596 IM |
3737 | { |
3738 | struct task_struct *prev, *next; | |
67ca7bde | 3739 | unsigned long *switch_count; |
dd41f596 | 3740 | struct rq *rq; |
31656519 | 3741 | int cpu; |
dd41f596 | 3742 | |
ff743345 PZ |
3743 | need_resched: |
3744 | preempt_disable(); | |
dd41f596 IM |
3745 | cpu = smp_processor_id(); |
3746 | rq = cpu_rq(cpu); | |
25502a6c | 3747 | rcu_note_context_switch(cpu); |
dd41f596 | 3748 | prev = rq->curr; |
dd41f596 IM |
3749 | |
3750 | release_kernel_lock(prev); | |
3751 | need_resched_nonpreemptible: | |
3752 | ||
3753 | schedule_debug(prev); | |
1da177e4 | 3754 | |
31656519 | 3755 | if (sched_feat(HRTICK)) |
f333fdc9 | 3756 | hrtick_clear(rq); |
8f4d37ec | 3757 | |
05fa785c | 3758 | raw_spin_lock_irq(&rq->lock); |
1e819950 | 3759 | clear_tsk_need_resched(prev); |
1da177e4 | 3760 | |
246d86b5 | 3761 | switch_count = &prev->nivcsw; |
1da177e4 | 3762 | if (prev->state && !(preempt_count() & PREEMPT_ACTIVE)) { |
21aa9af0 | 3763 | if (unlikely(signal_pending_state(prev->state, prev))) { |
1da177e4 | 3764 | prev->state = TASK_RUNNING; |
21aa9af0 TH |
3765 | } else { |
3766 | /* | |
3767 | * If a worker is going to sleep, notify and | |
3768 | * ask workqueue whether it wants to wake up a | |
3769 | * task to maintain concurrency. If so, wake | |
3770 | * up the task. | |
3771 | */ | |
3772 | if (prev->flags & PF_WQ_WORKER) { | |
3773 | struct task_struct *to_wakeup; | |
3774 | ||
3775 | to_wakeup = wq_worker_sleeping(prev, cpu); | |
3776 | if (to_wakeup) | |
3777 | try_to_wake_up_local(to_wakeup); | |
3778 | } | |
371fd7e7 | 3779 | deactivate_task(rq, prev, DEQUEUE_SLEEP); |
21aa9af0 | 3780 | } |
dd41f596 | 3781 | switch_count = &prev->nvcsw; |
1da177e4 LT |
3782 | } |
3783 | ||
3f029d3c | 3784 | pre_schedule(rq, prev); |
f65eda4f | 3785 | |
dd41f596 | 3786 | if (unlikely(!rq->nr_running)) |
1da177e4 | 3787 | idle_balance(cpu, rq); |
1da177e4 | 3788 | |
df1c99d4 | 3789 | put_prev_task(rq, prev); |
b67802ea | 3790 | next = pick_next_task(rq); |
1da177e4 | 3791 | |
1da177e4 | 3792 | if (likely(prev != next)) { |
673a90a1 | 3793 | sched_info_switch(prev, next); |
49f47433 | 3794 | perf_event_task_sched_out(prev, next); |
673a90a1 | 3795 | |
1da177e4 LT |
3796 | rq->nr_switches++; |
3797 | rq->curr = next; | |
3798 | ++*switch_count; | |
3799 | ||
dd41f596 | 3800 | context_switch(rq, prev, next); /* unlocks the rq */ |
8f4d37ec | 3801 | /* |
246d86b5 ON |
3802 | * The context switch have flipped the stack from under us |
3803 | * and restored the local variables which were saved when | |
3804 | * this task called schedule() in the past. prev == current | |
3805 | * is still correct, but it can be moved to another cpu/rq. | |
8f4d37ec PZ |
3806 | */ |
3807 | cpu = smp_processor_id(); | |
3808 | rq = cpu_rq(cpu); | |
1da177e4 | 3809 | } else |
05fa785c | 3810 | raw_spin_unlock_irq(&rq->lock); |
1da177e4 | 3811 | |
3f029d3c | 3812 | post_schedule(rq); |
1da177e4 | 3813 | |
246d86b5 | 3814 | if (unlikely(reacquire_kernel_lock(prev))) |
1da177e4 | 3815 | goto need_resched_nonpreemptible; |
8f4d37ec | 3816 | |
1da177e4 | 3817 | preempt_enable_no_resched(); |
ff743345 | 3818 | if (need_resched()) |
1da177e4 LT |
3819 | goto need_resched; |
3820 | } | |
1da177e4 LT |
3821 | EXPORT_SYMBOL(schedule); |
3822 | ||
c08f7829 | 3823 | #ifdef CONFIG_MUTEX_SPIN_ON_OWNER |
0d66bf6d PZ |
3824 | /* |
3825 | * Look out! "owner" is an entirely speculative pointer | |
3826 | * access and not reliable. | |
3827 | */ | |
3828 | int mutex_spin_on_owner(struct mutex *lock, struct thread_info *owner) | |
3829 | { | |
3830 | unsigned int cpu; | |
3831 | struct rq *rq; | |
3832 | ||
3833 | if (!sched_feat(OWNER_SPIN)) | |
3834 | return 0; | |
3835 | ||
3836 | #ifdef CONFIG_DEBUG_PAGEALLOC | |
3837 | /* | |
3838 | * Need to access the cpu field knowing that | |
3839 | * DEBUG_PAGEALLOC could have unmapped it if | |
3840 | * the mutex owner just released it and exited. | |
3841 | */ | |
3842 | if (probe_kernel_address(&owner->cpu, cpu)) | |
4b402210 | 3843 | return 0; |
0d66bf6d PZ |
3844 | #else |
3845 | cpu = owner->cpu; | |
3846 | #endif | |
3847 | ||
3848 | /* | |
3849 | * Even if the access succeeded (likely case), | |
3850 | * the cpu field may no longer be valid. | |
3851 | */ | |
3852 | if (cpu >= nr_cpumask_bits) | |
4b402210 | 3853 | return 0; |
0d66bf6d PZ |
3854 | |
3855 | /* | |
3856 | * We need to validate that we can do a | |
3857 | * get_cpu() and that we have the percpu area. | |
3858 | */ | |
3859 | if (!cpu_online(cpu)) | |
4b402210 | 3860 | return 0; |
0d66bf6d PZ |
3861 | |
3862 | rq = cpu_rq(cpu); | |
3863 | ||
3864 | for (;;) { | |
3865 | /* | |
3866 | * Owner changed, break to re-assess state. | |
3867 | */ | |
3868 | if (lock->owner != owner) | |
3869 | break; | |
3870 | ||
3871 | /* | |
3872 | * Is that owner really running on that cpu? | |
3873 | */ | |
3874 | if (task_thread_info(rq->curr) != owner || need_resched()) | |
3875 | return 0; | |
3876 | ||
3877 | cpu_relax(); | |
3878 | } | |
4b402210 | 3879 | |
0d66bf6d PZ |
3880 | return 1; |
3881 | } | |
3882 | #endif | |
3883 | ||
1da177e4 LT |
3884 | #ifdef CONFIG_PREEMPT |
3885 | /* | |
2ed6e34f | 3886 | * this is the entry point to schedule() from in-kernel preemption |
41a2d6cf | 3887 | * off of preempt_enable. Kernel preemptions off return from interrupt |
1da177e4 LT |
3888 | * occur there and call schedule directly. |
3889 | */ | |
d1f74e20 | 3890 | asmlinkage void __sched notrace preempt_schedule(void) |
1da177e4 LT |
3891 | { |
3892 | struct thread_info *ti = current_thread_info(); | |
6478d880 | 3893 | |
1da177e4 LT |
3894 | /* |
3895 | * If there is a non-zero preempt_count or interrupts are disabled, | |
41a2d6cf | 3896 | * we do not want to preempt the current task. Just return.. |
1da177e4 | 3897 | */ |
beed33a8 | 3898 | if (likely(ti->preempt_count || irqs_disabled())) |
1da177e4 LT |
3899 | return; |
3900 | ||
3a5c359a | 3901 | do { |
d1f74e20 | 3902 | add_preempt_count_notrace(PREEMPT_ACTIVE); |
3a5c359a | 3903 | schedule(); |
d1f74e20 | 3904 | sub_preempt_count_notrace(PREEMPT_ACTIVE); |
1da177e4 | 3905 | |
3a5c359a AK |
3906 | /* |
3907 | * Check again in case we missed a preemption opportunity | |
3908 | * between schedule and now. | |
3909 | */ | |
3910 | barrier(); | |
5ed0cec0 | 3911 | } while (need_resched()); |
1da177e4 | 3912 | } |
1da177e4 LT |
3913 | EXPORT_SYMBOL(preempt_schedule); |
3914 | ||
3915 | /* | |
2ed6e34f | 3916 | * this is the entry point to schedule() from kernel preemption |
1da177e4 LT |
3917 | * off of irq context. |
3918 | * Note, that this is called and return with irqs disabled. This will | |
3919 | * protect us against recursive calling from irq. | |
3920 | */ | |
3921 | asmlinkage void __sched preempt_schedule_irq(void) | |
3922 | { | |
3923 | struct thread_info *ti = current_thread_info(); | |
6478d880 | 3924 | |
2ed6e34f | 3925 | /* Catch callers which need to be fixed */ |
1da177e4 LT |
3926 | BUG_ON(ti->preempt_count || !irqs_disabled()); |
3927 | ||
3a5c359a AK |
3928 | do { |
3929 | add_preempt_count(PREEMPT_ACTIVE); | |
3a5c359a AK |
3930 | local_irq_enable(); |
3931 | schedule(); | |
3932 | local_irq_disable(); | |
3a5c359a | 3933 | sub_preempt_count(PREEMPT_ACTIVE); |
1da177e4 | 3934 | |
3a5c359a AK |
3935 | /* |
3936 | * Check again in case we missed a preemption opportunity | |
3937 | * between schedule and now. | |
3938 | */ | |
3939 | barrier(); | |
5ed0cec0 | 3940 | } while (need_resched()); |
1da177e4 LT |
3941 | } |
3942 | ||
3943 | #endif /* CONFIG_PREEMPT */ | |
3944 | ||
63859d4f | 3945 | int default_wake_function(wait_queue_t *curr, unsigned mode, int wake_flags, |
95cdf3b7 | 3946 | void *key) |
1da177e4 | 3947 | { |
63859d4f | 3948 | return try_to_wake_up(curr->private, mode, wake_flags); |
1da177e4 | 3949 | } |
1da177e4 LT |
3950 | EXPORT_SYMBOL(default_wake_function); |
3951 | ||
3952 | /* | |
41a2d6cf IM |
3953 | * The core wakeup function. Non-exclusive wakeups (nr_exclusive == 0) just |
3954 | * wake everything up. If it's an exclusive wakeup (nr_exclusive == small +ve | |
1da177e4 LT |
3955 | * number) then we wake all the non-exclusive tasks and one exclusive task. |
3956 | * | |
3957 | * There are circumstances in which we can try to wake a task which has already | |
41a2d6cf | 3958 | * started to run but is not in state TASK_RUNNING. try_to_wake_up() returns |
1da177e4 LT |
3959 | * zero in this (rare) case, and we handle it by continuing to scan the queue. |
3960 | */ | |
78ddb08f | 3961 | static void __wake_up_common(wait_queue_head_t *q, unsigned int mode, |
63859d4f | 3962 | int nr_exclusive, int wake_flags, void *key) |
1da177e4 | 3963 | { |
2e45874c | 3964 | wait_queue_t *curr, *next; |
1da177e4 | 3965 | |
2e45874c | 3966 | list_for_each_entry_safe(curr, next, &q->task_list, task_list) { |
48f24c4d IM |
3967 | unsigned flags = curr->flags; |
3968 | ||
63859d4f | 3969 | if (curr->func(curr, mode, wake_flags, key) && |
48f24c4d | 3970 | (flags & WQ_FLAG_EXCLUSIVE) && !--nr_exclusive) |
1da177e4 LT |
3971 | break; |
3972 | } | |
3973 | } | |
3974 | ||
3975 | /** | |
3976 | * __wake_up - wake up threads blocked on a waitqueue. | |
3977 | * @q: the waitqueue | |
3978 | * @mode: which threads | |
3979 | * @nr_exclusive: how many wake-one or wake-many threads to wake up | |
67be2dd1 | 3980 | * @key: is directly passed to the wakeup function |
50fa610a DH |
3981 | * |
3982 | * It may be assumed that this function implies a write memory barrier before | |
3983 | * changing the task state if and only if any tasks are woken up. | |
1da177e4 | 3984 | */ |
7ad5b3a5 | 3985 | void __wake_up(wait_queue_head_t *q, unsigned int mode, |
95cdf3b7 | 3986 | int nr_exclusive, void *key) |
1da177e4 LT |
3987 | { |
3988 | unsigned long flags; | |
3989 | ||
3990 | spin_lock_irqsave(&q->lock, flags); | |
3991 | __wake_up_common(q, mode, nr_exclusive, 0, key); | |
3992 | spin_unlock_irqrestore(&q->lock, flags); | |
3993 | } | |
1da177e4 LT |
3994 | EXPORT_SYMBOL(__wake_up); |
3995 | ||
3996 | /* | |
3997 | * Same as __wake_up but called with the spinlock in wait_queue_head_t held. | |
3998 | */ | |
7ad5b3a5 | 3999 | void __wake_up_locked(wait_queue_head_t *q, unsigned int mode) |
1da177e4 LT |
4000 | { |
4001 | __wake_up_common(q, mode, 1, 0, NULL); | |
4002 | } | |
22c43c81 | 4003 | EXPORT_SYMBOL_GPL(__wake_up_locked); |
1da177e4 | 4004 | |
4ede816a DL |
4005 | void __wake_up_locked_key(wait_queue_head_t *q, unsigned int mode, void *key) |
4006 | { | |
4007 | __wake_up_common(q, mode, 1, 0, key); | |
4008 | } | |
4009 | ||
1da177e4 | 4010 | /** |
4ede816a | 4011 | * __wake_up_sync_key - wake up threads blocked on a waitqueue. |
1da177e4 LT |
4012 | * @q: the waitqueue |
4013 | * @mode: which threads | |
4014 | * @nr_exclusive: how many wake-one or wake-many threads to wake up | |
4ede816a | 4015 | * @key: opaque value to be passed to wakeup targets |
1da177e4 LT |
4016 | * |
4017 | * The sync wakeup differs that the waker knows that it will schedule | |
4018 | * away soon, so while the target thread will be woken up, it will not | |
4019 | * be migrated to another CPU - ie. the two threads are 'synchronized' | |
4020 | * with each other. This can prevent needless bouncing between CPUs. | |
4021 | * | |
4022 | * On UP it can prevent extra preemption. | |
50fa610a DH |
4023 | * |
4024 | * It may be assumed that this function implies a write memory barrier before | |
4025 | * changing the task state if and only if any tasks are woken up. | |
1da177e4 | 4026 | */ |
4ede816a DL |
4027 | void __wake_up_sync_key(wait_queue_head_t *q, unsigned int mode, |
4028 | int nr_exclusive, void *key) | |
1da177e4 LT |
4029 | { |
4030 | unsigned long flags; | |
7d478721 | 4031 | int wake_flags = WF_SYNC; |
1da177e4 LT |
4032 | |
4033 | if (unlikely(!q)) | |
4034 | return; | |
4035 | ||
4036 | if (unlikely(!nr_exclusive)) | |
7d478721 | 4037 | wake_flags = 0; |
1da177e4 LT |
4038 | |
4039 | spin_lock_irqsave(&q->lock, flags); | |
7d478721 | 4040 | __wake_up_common(q, mode, nr_exclusive, wake_flags, key); |
1da177e4 LT |
4041 | spin_unlock_irqrestore(&q->lock, flags); |
4042 | } | |
4ede816a DL |
4043 | EXPORT_SYMBOL_GPL(__wake_up_sync_key); |
4044 | ||
4045 | /* | |
4046 | * __wake_up_sync - see __wake_up_sync_key() | |
4047 | */ | |
4048 | void __wake_up_sync(wait_queue_head_t *q, unsigned int mode, int nr_exclusive) | |
4049 | { | |
4050 | __wake_up_sync_key(q, mode, nr_exclusive, NULL); | |
4051 | } | |
1da177e4 LT |
4052 | EXPORT_SYMBOL_GPL(__wake_up_sync); /* For internal use only */ |
4053 | ||
65eb3dc6 KD |
4054 | /** |
4055 | * complete: - signals a single thread waiting on this completion | |
4056 | * @x: holds the state of this particular completion | |
4057 | * | |
4058 | * This will wake up a single thread waiting on this completion. Threads will be | |
4059 | * awakened in the same order in which they were queued. | |
4060 | * | |
4061 | * See also complete_all(), wait_for_completion() and related routines. | |
50fa610a DH |
4062 | * |
4063 | * It may be assumed that this function implies a write memory barrier before | |
4064 | * changing the task state if and only if any tasks are woken up. | |
65eb3dc6 | 4065 | */ |
b15136e9 | 4066 | void complete(struct completion *x) |
1da177e4 LT |
4067 | { |
4068 | unsigned long flags; | |
4069 | ||
4070 | spin_lock_irqsave(&x->wait.lock, flags); | |
4071 | x->done++; | |
d9514f6c | 4072 | __wake_up_common(&x->wait, TASK_NORMAL, 1, 0, NULL); |
1da177e4 LT |
4073 | spin_unlock_irqrestore(&x->wait.lock, flags); |
4074 | } | |
4075 | EXPORT_SYMBOL(complete); | |
4076 | ||
65eb3dc6 KD |
4077 | /** |
4078 | * complete_all: - signals all threads waiting on this completion | |
4079 | * @x: holds the state of this particular completion | |
4080 | * | |
4081 | * This will wake up all threads waiting on this particular completion event. | |
50fa610a DH |
4082 | * |
4083 | * It may be assumed that this function implies a write memory barrier before | |
4084 | * changing the task state if and only if any tasks are woken up. | |
65eb3dc6 | 4085 | */ |
b15136e9 | 4086 | void complete_all(struct completion *x) |
1da177e4 LT |
4087 | { |
4088 | unsigned long flags; | |
4089 | ||
4090 | spin_lock_irqsave(&x->wait.lock, flags); | |
4091 | x->done += UINT_MAX/2; | |
d9514f6c | 4092 | __wake_up_common(&x->wait, TASK_NORMAL, 0, 0, NULL); |
1da177e4 LT |
4093 | spin_unlock_irqrestore(&x->wait.lock, flags); |
4094 | } | |
4095 | EXPORT_SYMBOL(complete_all); | |
4096 | ||
8cbbe86d AK |
4097 | static inline long __sched |
4098 | do_wait_for_common(struct completion *x, long timeout, int state) | |
1da177e4 | 4099 | { |
1da177e4 LT |
4100 | if (!x->done) { |
4101 | DECLARE_WAITQUEUE(wait, current); | |
4102 | ||
a93d2f17 | 4103 | __add_wait_queue_tail_exclusive(&x->wait, &wait); |
1da177e4 | 4104 | do { |
94d3d824 | 4105 | if (signal_pending_state(state, current)) { |
ea71a546 ON |
4106 | timeout = -ERESTARTSYS; |
4107 | break; | |
8cbbe86d AK |
4108 | } |
4109 | __set_current_state(state); | |
1da177e4 LT |
4110 | spin_unlock_irq(&x->wait.lock); |
4111 | timeout = schedule_timeout(timeout); | |
4112 | spin_lock_irq(&x->wait.lock); | |
ea71a546 | 4113 | } while (!x->done && timeout); |
1da177e4 | 4114 | __remove_wait_queue(&x->wait, &wait); |
ea71a546 ON |
4115 | if (!x->done) |
4116 | return timeout; | |
1da177e4 LT |
4117 | } |
4118 | x->done--; | |
ea71a546 | 4119 | return timeout ?: 1; |
1da177e4 | 4120 | } |
1da177e4 | 4121 | |
8cbbe86d AK |
4122 | static long __sched |
4123 | wait_for_common(struct completion *x, long timeout, int state) | |
1da177e4 | 4124 | { |
1da177e4 LT |
4125 | might_sleep(); |
4126 | ||
4127 | spin_lock_irq(&x->wait.lock); | |
8cbbe86d | 4128 | timeout = do_wait_for_common(x, timeout, state); |
1da177e4 | 4129 | spin_unlock_irq(&x->wait.lock); |
8cbbe86d AK |
4130 | return timeout; |
4131 | } | |
1da177e4 | 4132 | |
65eb3dc6 KD |
4133 | /** |
4134 | * wait_for_completion: - waits for completion of a task | |
4135 | * @x: holds the state of this particular completion | |
4136 | * | |
4137 | * This waits to be signaled for completion of a specific task. It is NOT | |
4138 | * interruptible and there is no timeout. | |
4139 | * | |
4140 | * See also similar routines (i.e. wait_for_completion_timeout()) with timeout | |
4141 | * and interrupt capability. Also see complete(). | |
4142 | */ | |
b15136e9 | 4143 | void __sched wait_for_completion(struct completion *x) |
8cbbe86d AK |
4144 | { |
4145 | wait_for_common(x, MAX_SCHEDULE_TIMEOUT, TASK_UNINTERRUPTIBLE); | |
1da177e4 | 4146 | } |
8cbbe86d | 4147 | EXPORT_SYMBOL(wait_for_completion); |
1da177e4 | 4148 | |
65eb3dc6 KD |
4149 | /** |
4150 | * wait_for_completion_timeout: - waits for completion of a task (w/timeout) | |
4151 | * @x: holds the state of this particular completion | |
4152 | * @timeout: timeout value in jiffies | |
4153 | * | |
4154 | * This waits for either a completion of a specific task to be signaled or for a | |
4155 | * specified timeout to expire. The timeout is in jiffies. It is not | |
4156 | * interruptible. | |
4157 | */ | |
b15136e9 | 4158 | unsigned long __sched |
8cbbe86d | 4159 | wait_for_completion_timeout(struct completion *x, unsigned long timeout) |
1da177e4 | 4160 | { |
8cbbe86d | 4161 | return wait_for_common(x, timeout, TASK_UNINTERRUPTIBLE); |
1da177e4 | 4162 | } |
8cbbe86d | 4163 | EXPORT_SYMBOL(wait_for_completion_timeout); |
1da177e4 | 4164 | |
65eb3dc6 KD |
4165 | /** |
4166 | * wait_for_completion_interruptible: - waits for completion of a task (w/intr) | |
4167 | * @x: holds the state of this particular completion | |
4168 | * | |
4169 | * This waits for completion of a specific task to be signaled. It is | |
4170 | * interruptible. | |
4171 | */ | |
8cbbe86d | 4172 | int __sched wait_for_completion_interruptible(struct completion *x) |
0fec171c | 4173 | { |
51e97990 AK |
4174 | long t = wait_for_common(x, MAX_SCHEDULE_TIMEOUT, TASK_INTERRUPTIBLE); |
4175 | if (t == -ERESTARTSYS) | |
4176 | return t; | |
4177 | return 0; | |
0fec171c | 4178 | } |
8cbbe86d | 4179 | EXPORT_SYMBOL(wait_for_completion_interruptible); |
1da177e4 | 4180 | |
65eb3dc6 KD |
4181 | /** |
4182 | * wait_for_completion_interruptible_timeout: - waits for completion (w/(to,intr)) | |
4183 | * @x: holds the state of this particular completion | |
4184 | * @timeout: timeout value in jiffies | |
4185 | * | |
4186 | * This waits for either a completion of a specific task to be signaled or for a | |
4187 | * specified timeout to expire. It is interruptible. The timeout is in jiffies. | |
4188 | */ | |
b15136e9 | 4189 | unsigned long __sched |
8cbbe86d AK |
4190 | wait_for_completion_interruptible_timeout(struct completion *x, |
4191 | unsigned long timeout) | |
0fec171c | 4192 | { |
8cbbe86d | 4193 | return wait_for_common(x, timeout, TASK_INTERRUPTIBLE); |
0fec171c | 4194 | } |
8cbbe86d | 4195 | EXPORT_SYMBOL(wait_for_completion_interruptible_timeout); |
1da177e4 | 4196 | |
65eb3dc6 KD |
4197 | /** |
4198 | * wait_for_completion_killable: - waits for completion of a task (killable) | |
4199 | * @x: holds the state of this particular completion | |
4200 | * | |
4201 | * This waits to be signaled for completion of a specific task. It can be | |
4202 | * interrupted by a kill signal. | |
4203 | */ | |
009e577e MW |
4204 | int __sched wait_for_completion_killable(struct completion *x) |
4205 | { | |
4206 | long t = wait_for_common(x, MAX_SCHEDULE_TIMEOUT, TASK_KILLABLE); | |
4207 | if (t == -ERESTARTSYS) | |
4208 | return t; | |
4209 | return 0; | |
4210 | } | |
4211 | EXPORT_SYMBOL(wait_for_completion_killable); | |
4212 | ||
0aa12fb4 SW |
4213 | /** |
4214 | * wait_for_completion_killable_timeout: - waits for completion of a task (w/(to,killable)) | |
4215 | * @x: holds the state of this particular completion | |
4216 | * @timeout: timeout value in jiffies | |
4217 | * | |
4218 | * This waits for either a completion of a specific task to be | |
4219 | * signaled or for a specified timeout to expire. It can be | |
4220 | * interrupted by a kill signal. The timeout is in jiffies. | |
4221 | */ | |
4222 | unsigned long __sched | |
4223 | wait_for_completion_killable_timeout(struct completion *x, | |
4224 | unsigned long timeout) | |
4225 | { | |
4226 | return wait_for_common(x, timeout, TASK_KILLABLE); | |
4227 | } | |
4228 | EXPORT_SYMBOL(wait_for_completion_killable_timeout); | |
4229 | ||
be4de352 DC |
4230 | /** |
4231 | * try_wait_for_completion - try to decrement a completion without blocking | |
4232 | * @x: completion structure | |
4233 | * | |
4234 | * Returns: 0 if a decrement cannot be done without blocking | |
4235 | * 1 if a decrement succeeded. | |
4236 | * | |
4237 | * If a completion is being used as a counting completion, | |
4238 | * attempt to decrement the counter without blocking. This | |
4239 | * enables us to avoid waiting if the resource the completion | |
4240 | * is protecting is not available. | |
4241 | */ | |
4242 | bool try_wait_for_completion(struct completion *x) | |
4243 | { | |
7539a3b3 | 4244 | unsigned long flags; |
be4de352 DC |
4245 | int ret = 1; |
4246 | ||
7539a3b3 | 4247 | spin_lock_irqsave(&x->wait.lock, flags); |
be4de352 DC |
4248 | if (!x->done) |
4249 | ret = 0; | |
4250 | else | |
4251 | x->done--; | |
7539a3b3 | 4252 | spin_unlock_irqrestore(&x->wait.lock, flags); |
be4de352 DC |
4253 | return ret; |
4254 | } | |
4255 | EXPORT_SYMBOL(try_wait_for_completion); | |
4256 | ||
4257 | /** | |
4258 | * completion_done - Test to see if a completion has any waiters | |
4259 | * @x: completion structure | |
4260 | * | |
4261 | * Returns: 0 if there are waiters (wait_for_completion() in progress) | |
4262 | * 1 if there are no waiters. | |
4263 | * | |
4264 | */ | |
4265 | bool completion_done(struct completion *x) | |
4266 | { | |
7539a3b3 | 4267 | unsigned long flags; |
be4de352 DC |
4268 | int ret = 1; |
4269 | ||
7539a3b3 | 4270 | spin_lock_irqsave(&x->wait.lock, flags); |
be4de352 DC |
4271 | if (!x->done) |
4272 | ret = 0; | |
7539a3b3 | 4273 | spin_unlock_irqrestore(&x->wait.lock, flags); |
be4de352 DC |
4274 | return ret; |
4275 | } | |
4276 | EXPORT_SYMBOL(completion_done); | |
4277 | ||
8cbbe86d AK |
4278 | static long __sched |
4279 | sleep_on_common(wait_queue_head_t *q, int state, long timeout) | |
1da177e4 | 4280 | { |
0fec171c IM |
4281 | unsigned long flags; |
4282 | wait_queue_t wait; | |
4283 | ||
4284 | init_waitqueue_entry(&wait, current); | |
1da177e4 | 4285 | |
8cbbe86d | 4286 | __set_current_state(state); |
1da177e4 | 4287 | |
8cbbe86d AK |
4288 | spin_lock_irqsave(&q->lock, flags); |
4289 | __add_wait_queue(q, &wait); | |
4290 | spin_unlock(&q->lock); | |
4291 | timeout = schedule_timeout(timeout); | |
4292 | spin_lock_irq(&q->lock); | |
4293 | __remove_wait_queue(q, &wait); | |
4294 | spin_unlock_irqrestore(&q->lock, flags); | |
4295 | ||
4296 | return timeout; | |
4297 | } | |
4298 | ||
4299 | void __sched interruptible_sleep_on(wait_queue_head_t *q) | |
4300 | { | |
4301 | sleep_on_common(q, TASK_INTERRUPTIBLE, MAX_SCHEDULE_TIMEOUT); | |
1da177e4 | 4302 | } |
1da177e4 LT |
4303 | EXPORT_SYMBOL(interruptible_sleep_on); |
4304 | ||
0fec171c | 4305 | long __sched |
95cdf3b7 | 4306 | interruptible_sleep_on_timeout(wait_queue_head_t *q, long timeout) |
1da177e4 | 4307 | { |
8cbbe86d | 4308 | return sleep_on_common(q, TASK_INTERRUPTIBLE, timeout); |
1da177e4 | 4309 | } |
1da177e4 LT |
4310 | EXPORT_SYMBOL(interruptible_sleep_on_timeout); |
4311 | ||
0fec171c | 4312 | void __sched sleep_on(wait_queue_head_t *q) |
1da177e4 | 4313 | { |
8cbbe86d | 4314 | sleep_on_common(q, TASK_UNINTERRUPTIBLE, MAX_SCHEDULE_TIMEOUT); |
1da177e4 | 4315 | } |
1da177e4 LT |
4316 | EXPORT_SYMBOL(sleep_on); |
4317 | ||
0fec171c | 4318 | long __sched sleep_on_timeout(wait_queue_head_t *q, long timeout) |
1da177e4 | 4319 | { |
8cbbe86d | 4320 | return sleep_on_common(q, TASK_UNINTERRUPTIBLE, timeout); |
1da177e4 | 4321 | } |
1da177e4 LT |
4322 | EXPORT_SYMBOL(sleep_on_timeout); |
4323 | ||
b29739f9 IM |
4324 | #ifdef CONFIG_RT_MUTEXES |
4325 | ||
4326 | /* | |
4327 | * rt_mutex_setprio - set the current priority of a task | |
4328 | * @p: task | |
4329 | * @prio: prio value (kernel-internal form) | |
4330 | * | |
4331 | * This function changes the 'effective' priority of a task. It does | |
4332 | * not touch ->normal_prio like __setscheduler(). | |
4333 | * | |
4334 | * Used by the rt_mutex code to implement priority inheritance logic. | |
4335 | */ | |
36c8b586 | 4336 | void rt_mutex_setprio(struct task_struct *p, int prio) |
b29739f9 IM |
4337 | { |
4338 | unsigned long flags; | |
83b699ed | 4339 | int oldprio, on_rq, running; |
70b97a7f | 4340 | struct rq *rq; |
83ab0aa0 | 4341 | const struct sched_class *prev_class; |
b29739f9 IM |
4342 | |
4343 | BUG_ON(prio < 0 || prio > MAX_PRIO); | |
4344 | ||
4345 | rq = task_rq_lock(p, &flags); | |
4346 | ||
d5f9f942 | 4347 | oldprio = p->prio; |
83ab0aa0 | 4348 | prev_class = p->sched_class; |
dd41f596 | 4349 | on_rq = p->se.on_rq; |
051a1d1a | 4350 | running = task_current(rq, p); |
0e1f3483 | 4351 | if (on_rq) |
69be72c1 | 4352 | dequeue_task(rq, p, 0); |
0e1f3483 HS |
4353 | if (running) |
4354 | p->sched_class->put_prev_task(rq, p); | |
dd41f596 IM |
4355 | |
4356 | if (rt_prio(prio)) | |
4357 | p->sched_class = &rt_sched_class; | |
4358 | else | |
4359 | p->sched_class = &fair_sched_class; | |
4360 | ||
b29739f9 IM |
4361 | p->prio = prio; |
4362 | ||
0e1f3483 HS |
4363 | if (running) |
4364 | p->sched_class->set_curr_task(rq); | |
dd41f596 | 4365 | if (on_rq) { |
371fd7e7 | 4366 | enqueue_task(rq, p, oldprio < prio ? ENQUEUE_HEAD : 0); |
cb469845 SR |
4367 | |
4368 | check_class_changed(rq, p, prev_class, oldprio, running); | |
b29739f9 IM |
4369 | } |
4370 | task_rq_unlock(rq, &flags); | |
4371 | } | |
4372 | ||
4373 | #endif | |
4374 | ||
36c8b586 | 4375 | void set_user_nice(struct task_struct *p, long nice) |
1da177e4 | 4376 | { |
dd41f596 | 4377 | int old_prio, delta, on_rq; |
1da177e4 | 4378 | unsigned long flags; |
70b97a7f | 4379 | struct rq *rq; |
1da177e4 LT |
4380 | |
4381 | if (TASK_NICE(p) == nice || nice < -20 || nice > 19) | |
4382 | return; | |
4383 | /* | |
4384 | * We have to be careful, if called from sys_setpriority(), | |
4385 | * the task might be in the middle of scheduling on another CPU. | |
4386 | */ | |
4387 | rq = task_rq_lock(p, &flags); | |
4388 | /* | |
4389 | * The RT priorities are set via sched_setscheduler(), but we still | |
4390 | * allow the 'normal' nice value to be set - but as expected | |
4391 | * it wont have any effect on scheduling until the task is | |
dd41f596 | 4392 | * SCHED_FIFO/SCHED_RR: |
1da177e4 | 4393 | */ |
e05606d3 | 4394 | if (task_has_rt_policy(p)) { |
1da177e4 LT |
4395 | p->static_prio = NICE_TO_PRIO(nice); |
4396 | goto out_unlock; | |
4397 | } | |
dd41f596 | 4398 | on_rq = p->se.on_rq; |
c09595f6 | 4399 | if (on_rq) |
69be72c1 | 4400 | dequeue_task(rq, p, 0); |
1da177e4 | 4401 | |
1da177e4 | 4402 | p->static_prio = NICE_TO_PRIO(nice); |
2dd73a4f | 4403 | set_load_weight(p); |
b29739f9 IM |
4404 | old_prio = p->prio; |
4405 | p->prio = effective_prio(p); | |
4406 | delta = p->prio - old_prio; | |
1da177e4 | 4407 | |
dd41f596 | 4408 | if (on_rq) { |
371fd7e7 | 4409 | enqueue_task(rq, p, 0); |
1da177e4 | 4410 | /* |
d5f9f942 AM |
4411 | * If the task increased its priority or is running and |
4412 | * lowered its priority, then reschedule its CPU: | |
1da177e4 | 4413 | */ |
d5f9f942 | 4414 | if (delta < 0 || (delta > 0 && task_running(rq, p))) |
1da177e4 LT |
4415 | resched_task(rq->curr); |
4416 | } | |
4417 | out_unlock: | |
4418 | task_rq_unlock(rq, &flags); | |
4419 | } | |
1da177e4 LT |
4420 | EXPORT_SYMBOL(set_user_nice); |
4421 | ||
e43379f1 MM |
4422 | /* |
4423 | * can_nice - check if a task can reduce its nice value | |
4424 | * @p: task | |
4425 | * @nice: nice value | |
4426 | */ | |
36c8b586 | 4427 | int can_nice(const struct task_struct *p, const int nice) |
e43379f1 | 4428 | { |
024f4747 MM |
4429 | /* convert nice value [19,-20] to rlimit style value [1,40] */ |
4430 | int nice_rlim = 20 - nice; | |
48f24c4d | 4431 | |
78d7d407 | 4432 | return (nice_rlim <= task_rlimit(p, RLIMIT_NICE) || |
e43379f1 MM |
4433 | capable(CAP_SYS_NICE)); |
4434 | } | |
4435 | ||
1da177e4 LT |
4436 | #ifdef __ARCH_WANT_SYS_NICE |
4437 | ||
4438 | /* | |
4439 | * sys_nice - change the priority of the current process. | |
4440 | * @increment: priority increment | |
4441 | * | |
4442 | * sys_setpriority is a more generic, but much slower function that | |
4443 | * does similar things. | |
4444 | */ | |
5add95d4 | 4445 | SYSCALL_DEFINE1(nice, int, increment) |
1da177e4 | 4446 | { |
48f24c4d | 4447 | long nice, retval; |
1da177e4 LT |
4448 | |
4449 | /* | |
4450 | * Setpriority might change our priority at the same moment. | |
4451 | * We don't have to worry. Conceptually one call occurs first | |
4452 | * and we have a single winner. | |
4453 | */ | |
e43379f1 MM |
4454 | if (increment < -40) |
4455 | increment = -40; | |
1da177e4 LT |
4456 | if (increment > 40) |
4457 | increment = 40; | |
4458 | ||
2b8f836f | 4459 | nice = TASK_NICE(current) + increment; |
1da177e4 LT |
4460 | if (nice < -20) |
4461 | nice = -20; | |
4462 | if (nice > 19) | |
4463 | nice = 19; | |
4464 | ||
e43379f1 MM |
4465 | if (increment < 0 && !can_nice(current, nice)) |
4466 | return -EPERM; | |
4467 | ||
1da177e4 LT |
4468 | retval = security_task_setnice(current, nice); |
4469 | if (retval) | |
4470 | return retval; | |
4471 | ||
4472 | set_user_nice(current, nice); | |
4473 | return 0; | |
4474 | } | |
4475 | ||
4476 | #endif | |
4477 | ||
4478 | /** | |
4479 | * task_prio - return the priority value of a given task. | |
4480 | * @p: the task in question. | |
4481 | * | |
4482 | * This is the priority value as seen by users in /proc. | |
4483 | * RT tasks are offset by -200. Normal tasks are centered | |
4484 | * around 0, value goes from -16 to +15. | |
4485 | */ | |
36c8b586 | 4486 | int task_prio(const struct task_struct *p) |
1da177e4 LT |
4487 | { |
4488 | return p->prio - MAX_RT_PRIO; | |
4489 | } | |
4490 | ||
4491 | /** | |
4492 | * task_nice - return the nice value of a given task. | |
4493 | * @p: the task in question. | |
4494 | */ | |
36c8b586 | 4495 | int task_nice(const struct task_struct *p) |
1da177e4 LT |
4496 | { |
4497 | return TASK_NICE(p); | |
4498 | } | |
150d8bed | 4499 | EXPORT_SYMBOL(task_nice); |
1da177e4 LT |
4500 | |
4501 | /** | |
4502 | * idle_cpu - is a given cpu idle currently? | |
4503 | * @cpu: the processor in question. | |
4504 | */ | |
4505 | int idle_cpu(int cpu) | |
4506 | { | |
4507 | return cpu_curr(cpu) == cpu_rq(cpu)->idle; | |
4508 | } | |
4509 | ||
1da177e4 LT |
4510 | /** |
4511 | * idle_task - return the idle task for a given cpu. | |
4512 | * @cpu: the processor in question. | |
4513 | */ | |
36c8b586 | 4514 | struct task_struct *idle_task(int cpu) |
1da177e4 LT |
4515 | { |
4516 | return cpu_rq(cpu)->idle; | |
4517 | } | |
4518 | ||
4519 | /** | |
4520 | * find_process_by_pid - find a process with a matching PID value. | |
4521 | * @pid: the pid in question. | |
4522 | */ | |
a9957449 | 4523 | static struct task_struct *find_process_by_pid(pid_t pid) |
1da177e4 | 4524 | { |
228ebcbe | 4525 | return pid ? find_task_by_vpid(pid) : current; |
1da177e4 LT |
4526 | } |
4527 | ||
4528 | /* Actually do priority change: must hold rq lock. */ | |
dd41f596 IM |
4529 | static void |
4530 | __setscheduler(struct rq *rq, struct task_struct *p, int policy, int prio) | |
1da177e4 | 4531 | { |
dd41f596 | 4532 | BUG_ON(p->se.on_rq); |
48f24c4d | 4533 | |
1da177e4 LT |
4534 | p->policy = policy; |
4535 | p->rt_priority = prio; | |
b29739f9 IM |
4536 | p->normal_prio = normal_prio(p); |
4537 | /* we are holding p->pi_lock already */ | |
4538 | p->prio = rt_mutex_getprio(p); | |
ffd44db5 PZ |
4539 | if (rt_prio(p->prio)) |
4540 | p->sched_class = &rt_sched_class; | |
4541 | else | |
4542 | p->sched_class = &fair_sched_class; | |
2dd73a4f | 4543 | set_load_weight(p); |
1da177e4 LT |
4544 | } |
4545 | ||
c69e8d9c DH |
4546 | /* |
4547 | * check the target process has a UID that matches the current process's | |
4548 | */ | |
4549 | static bool check_same_owner(struct task_struct *p) | |
4550 | { | |
4551 | const struct cred *cred = current_cred(), *pcred; | |
4552 | bool match; | |
4553 | ||
4554 | rcu_read_lock(); | |
4555 | pcred = __task_cred(p); | |
4556 | match = (cred->euid == pcred->euid || | |
4557 | cred->euid == pcred->uid); | |
4558 | rcu_read_unlock(); | |
4559 | return match; | |
4560 | } | |
4561 | ||
961ccddd RR |
4562 | static int __sched_setscheduler(struct task_struct *p, int policy, |
4563 | struct sched_param *param, bool user) | |
1da177e4 | 4564 | { |
83b699ed | 4565 | int retval, oldprio, oldpolicy = -1, on_rq, running; |
1da177e4 | 4566 | unsigned long flags; |
83ab0aa0 | 4567 | const struct sched_class *prev_class; |
70b97a7f | 4568 | struct rq *rq; |
ca94c442 | 4569 | int reset_on_fork; |
1da177e4 | 4570 | |
66e5393a SR |
4571 | /* may grab non-irq protected spin_locks */ |
4572 | BUG_ON(in_interrupt()); | |
1da177e4 LT |
4573 | recheck: |
4574 | /* double check policy once rq lock held */ | |
ca94c442 LP |
4575 | if (policy < 0) { |
4576 | reset_on_fork = p->sched_reset_on_fork; | |
1da177e4 | 4577 | policy = oldpolicy = p->policy; |
ca94c442 LP |
4578 | } else { |
4579 | reset_on_fork = !!(policy & SCHED_RESET_ON_FORK); | |
4580 | policy &= ~SCHED_RESET_ON_FORK; | |
4581 | ||
4582 | if (policy != SCHED_FIFO && policy != SCHED_RR && | |
4583 | policy != SCHED_NORMAL && policy != SCHED_BATCH && | |
4584 | policy != SCHED_IDLE) | |
4585 | return -EINVAL; | |
4586 | } | |
4587 | ||
1da177e4 LT |
4588 | /* |
4589 | * Valid priorities for SCHED_FIFO and SCHED_RR are | |
dd41f596 IM |
4590 | * 1..MAX_USER_RT_PRIO-1, valid priority for SCHED_NORMAL, |
4591 | * SCHED_BATCH and SCHED_IDLE is 0. | |
1da177e4 LT |
4592 | */ |
4593 | if (param->sched_priority < 0 || | |
95cdf3b7 | 4594 | (p->mm && param->sched_priority > MAX_USER_RT_PRIO-1) || |
d46523ea | 4595 | (!p->mm && param->sched_priority > MAX_RT_PRIO-1)) |
1da177e4 | 4596 | return -EINVAL; |
e05606d3 | 4597 | if (rt_policy(policy) != (param->sched_priority != 0)) |
1da177e4 LT |
4598 | return -EINVAL; |
4599 | ||
37e4ab3f OC |
4600 | /* |
4601 | * Allow unprivileged RT tasks to decrease priority: | |
4602 | */ | |
961ccddd | 4603 | if (user && !capable(CAP_SYS_NICE)) { |
e05606d3 | 4604 | if (rt_policy(policy)) { |
a44702e8 ON |
4605 | unsigned long rlim_rtprio = |
4606 | task_rlimit(p, RLIMIT_RTPRIO); | |
8dc3e909 ON |
4607 | |
4608 | /* can't set/change the rt policy */ | |
4609 | if (policy != p->policy && !rlim_rtprio) | |
4610 | return -EPERM; | |
4611 | ||
4612 | /* can't increase priority */ | |
4613 | if (param->sched_priority > p->rt_priority && | |
4614 | param->sched_priority > rlim_rtprio) | |
4615 | return -EPERM; | |
4616 | } | |
dd41f596 IM |
4617 | /* |
4618 | * Like positive nice levels, dont allow tasks to | |
4619 | * move out of SCHED_IDLE either: | |
4620 | */ | |
4621 | if (p->policy == SCHED_IDLE && policy != SCHED_IDLE) | |
4622 | return -EPERM; | |
5fe1d75f | 4623 | |
37e4ab3f | 4624 | /* can't change other user's priorities */ |
c69e8d9c | 4625 | if (!check_same_owner(p)) |
37e4ab3f | 4626 | return -EPERM; |
ca94c442 LP |
4627 | |
4628 | /* Normal users shall not reset the sched_reset_on_fork flag */ | |
4629 | if (p->sched_reset_on_fork && !reset_on_fork) | |
4630 | return -EPERM; | |
37e4ab3f | 4631 | } |
1da177e4 | 4632 | |
725aad24 | 4633 | if (user) { |
725aad24 JF |
4634 | retval = security_task_setscheduler(p, policy, param); |
4635 | if (retval) | |
4636 | return retval; | |
4637 | } | |
4638 | ||
b29739f9 IM |
4639 | /* |
4640 | * make sure no PI-waiters arrive (or leave) while we are | |
4641 | * changing the priority of the task: | |
4642 | */ | |
1d615482 | 4643 | raw_spin_lock_irqsave(&p->pi_lock, flags); |
1da177e4 LT |
4644 | /* |
4645 | * To be able to change p->policy safely, the apropriate | |
4646 | * runqueue lock must be held. | |
4647 | */ | |
b29739f9 | 4648 | rq = __task_rq_lock(p); |
dc61b1d6 PZ |
4649 | |
4650 | #ifdef CONFIG_RT_GROUP_SCHED | |
4651 | if (user) { | |
4652 | /* | |
4653 | * Do not allow realtime tasks into groups that have no runtime | |
4654 | * assigned. | |
4655 | */ | |
4656 | if (rt_bandwidth_enabled() && rt_policy(policy) && | |
4657 | task_group(p)->rt_bandwidth.rt_runtime == 0) { | |
4658 | __task_rq_unlock(rq); | |
4659 | raw_spin_unlock_irqrestore(&p->pi_lock, flags); | |
4660 | return -EPERM; | |
4661 | } | |
4662 | } | |
4663 | #endif | |
4664 | ||
1da177e4 LT |
4665 | /* recheck policy now with rq lock held */ |
4666 | if (unlikely(oldpolicy != -1 && oldpolicy != p->policy)) { | |
4667 | policy = oldpolicy = -1; | |
b29739f9 | 4668 | __task_rq_unlock(rq); |
1d615482 | 4669 | raw_spin_unlock_irqrestore(&p->pi_lock, flags); |
1da177e4 LT |
4670 | goto recheck; |
4671 | } | |
dd41f596 | 4672 | on_rq = p->se.on_rq; |
051a1d1a | 4673 | running = task_current(rq, p); |
0e1f3483 | 4674 | if (on_rq) |
2e1cb74a | 4675 | deactivate_task(rq, p, 0); |
0e1f3483 HS |
4676 | if (running) |
4677 | p->sched_class->put_prev_task(rq, p); | |
f6b53205 | 4678 | |
ca94c442 LP |
4679 | p->sched_reset_on_fork = reset_on_fork; |
4680 | ||
1da177e4 | 4681 | oldprio = p->prio; |
83ab0aa0 | 4682 | prev_class = p->sched_class; |
dd41f596 | 4683 | __setscheduler(rq, p, policy, param->sched_priority); |
f6b53205 | 4684 | |
0e1f3483 HS |
4685 | if (running) |
4686 | p->sched_class->set_curr_task(rq); | |
dd41f596 IM |
4687 | if (on_rq) { |
4688 | activate_task(rq, p, 0); | |
cb469845 SR |
4689 | |
4690 | check_class_changed(rq, p, prev_class, oldprio, running); | |
1da177e4 | 4691 | } |
b29739f9 | 4692 | __task_rq_unlock(rq); |
1d615482 | 4693 | raw_spin_unlock_irqrestore(&p->pi_lock, flags); |
b29739f9 | 4694 | |
95e02ca9 TG |
4695 | rt_mutex_adjust_pi(p); |
4696 | ||
1da177e4 LT |
4697 | return 0; |
4698 | } | |
961ccddd RR |
4699 | |
4700 | /** | |
4701 | * sched_setscheduler - change the scheduling policy and/or RT priority of a thread. | |
4702 | * @p: the task in question. | |
4703 | * @policy: new policy. | |
4704 | * @param: structure containing the new RT priority. | |
4705 | * | |
4706 | * NOTE that the task may be already dead. | |
4707 | */ | |
4708 | int sched_setscheduler(struct task_struct *p, int policy, | |
4709 | struct sched_param *param) | |
4710 | { | |
4711 | return __sched_setscheduler(p, policy, param, true); | |
4712 | } | |
1da177e4 LT |
4713 | EXPORT_SYMBOL_GPL(sched_setscheduler); |
4714 | ||
961ccddd RR |
4715 | /** |
4716 | * sched_setscheduler_nocheck - change the scheduling policy and/or RT priority of a thread from kernelspace. | |
4717 | * @p: the task in question. | |
4718 | * @policy: new policy. | |
4719 | * @param: structure containing the new RT priority. | |
4720 | * | |
4721 | * Just like sched_setscheduler, only don't bother checking if the | |
4722 | * current context has permission. For example, this is needed in | |
4723 | * stop_machine(): we create temporary high priority worker threads, | |
4724 | * but our caller might not have that capability. | |
4725 | */ | |
4726 | int sched_setscheduler_nocheck(struct task_struct *p, int policy, | |
4727 | struct sched_param *param) | |
4728 | { | |
4729 | return __sched_setscheduler(p, policy, param, false); | |
4730 | } | |
4731 | ||
95cdf3b7 IM |
4732 | static int |
4733 | do_sched_setscheduler(pid_t pid, int policy, struct sched_param __user *param) | |
1da177e4 | 4734 | { |
1da177e4 LT |
4735 | struct sched_param lparam; |
4736 | struct task_struct *p; | |
36c8b586 | 4737 | int retval; |
1da177e4 LT |
4738 | |
4739 | if (!param || pid < 0) | |
4740 | return -EINVAL; | |
4741 | if (copy_from_user(&lparam, param, sizeof(struct sched_param))) | |
4742 | return -EFAULT; | |
5fe1d75f ON |
4743 | |
4744 | rcu_read_lock(); | |
4745 | retval = -ESRCH; | |
1da177e4 | 4746 | p = find_process_by_pid(pid); |
5fe1d75f ON |
4747 | if (p != NULL) |
4748 | retval = sched_setscheduler(p, policy, &lparam); | |
4749 | rcu_read_unlock(); | |
36c8b586 | 4750 | |
1da177e4 LT |
4751 | return retval; |
4752 | } | |
4753 | ||
4754 | /** | |
4755 | * sys_sched_setscheduler - set/change the scheduler policy and RT priority | |
4756 | * @pid: the pid in question. | |
4757 | * @policy: new policy. | |
4758 | * @param: structure containing the new RT priority. | |
4759 | */ | |
5add95d4 HC |
4760 | SYSCALL_DEFINE3(sched_setscheduler, pid_t, pid, int, policy, |
4761 | struct sched_param __user *, param) | |
1da177e4 | 4762 | { |
c21761f1 JB |
4763 | /* negative values for policy are not valid */ |
4764 | if (policy < 0) | |
4765 | return -EINVAL; | |
4766 | ||
1da177e4 LT |
4767 | return do_sched_setscheduler(pid, policy, param); |
4768 | } | |
4769 | ||
4770 | /** | |
4771 | * sys_sched_setparam - set/change the RT priority of a thread | |
4772 | * @pid: the pid in question. | |
4773 | * @param: structure containing the new RT priority. | |
4774 | */ | |
5add95d4 | 4775 | SYSCALL_DEFINE2(sched_setparam, pid_t, pid, struct sched_param __user *, param) |
1da177e4 LT |
4776 | { |
4777 | return do_sched_setscheduler(pid, -1, param); | |
4778 | } | |
4779 | ||
4780 | /** | |
4781 | * sys_sched_getscheduler - get the policy (scheduling class) of a thread | |
4782 | * @pid: the pid in question. | |
4783 | */ | |
5add95d4 | 4784 | SYSCALL_DEFINE1(sched_getscheduler, pid_t, pid) |
1da177e4 | 4785 | { |
36c8b586 | 4786 | struct task_struct *p; |
3a5c359a | 4787 | int retval; |
1da177e4 LT |
4788 | |
4789 | if (pid < 0) | |
3a5c359a | 4790 | return -EINVAL; |
1da177e4 LT |
4791 | |
4792 | retval = -ESRCH; | |
5fe85be0 | 4793 | rcu_read_lock(); |
1da177e4 LT |
4794 | p = find_process_by_pid(pid); |
4795 | if (p) { | |
4796 | retval = security_task_getscheduler(p); | |
4797 | if (!retval) | |
ca94c442 LP |
4798 | retval = p->policy |
4799 | | (p->sched_reset_on_fork ? SCHED_RESET_ON_FORK : 0); | |
1da177e4 | 4800 | } |
5fe85be0 | 4801 | rcu_read_unlock(); |
1da177e4 LT |
4802 | return retval; |
4803 | } | |
4804 | ||
4805 | /** | |
ca94c442 | 4806 | * sys_sched_getparam - get the RT priority of a thread |
1da177e4 LT |
4807 | * @pid: the pid in question. |
4808 | * @param: structure containing the RT priority. | |
4809 | */ | |
5add95d4 | 4810 | SYSCALL_DEFINE2(sched_getparam, pid_t, pid, struct sched_param __user *, param) |
1da177e4 LT |
4811 | { |
4812 | struct sched_param lp; | |
36c8b586 | 4813 | struct task_struct *p; |
3a5c359a | 4814 | int retval; |
1da177e4 LT |
4815 | |
4816 | if (!param || pid < 0) | |
3a5c359a | 4817 | return -EINVAL; |
1da177e4 | 4818 | |
5fe85be0 | 4819 | rcu_read_lock(); |
1da177e4 LT |
4820 | p = find_process_by_pid(pid); |
4821 | retval = -ESRCH; | |
4822 | if (!p) | |
4823 | goto out_unlock; | |
4824 | ||
4825 | retval = security_task_getscheduler(p); | |
4826 | if (retval) | |
4827 | goto out_unlock; | |
4828 | ||
4829 | lp.sched_priority = p->rt_priority; | |
5fe85be0 | 4830 | rcu_read_unlock(); |
1da177e4 LT |
4831 | |
4832 | /* | |
4833 | * This one might sleep, we cannot do it with a spinlock held ... | |
4834 | */ | |
4835 | retval = copy_to_user(param, &lp, sizeof(*param)) ? -EFAULT : 0; | |
4836 | ||
1da177e4 LT |
4837 | return retval; |
4838 | ||
4839 | out_unlock: | |
5fe85be0 | 4840 | rcu_read_unlock(); |
1da177e4 LT |
4841 | return retval; |
4842 | } | |
4843 | ||
96f874e2 | 4844 | long sched_setaffinity(pid_t pid, const struct cpumask *in_mask) |
1da177e4 | 4845 | { |
5a16f3d3 | 4846 | cpumask_var_t cpus_allowed, new_mask; |
36c8b586 IM |
4847 | struct task_struct *p; |
4848 | int retval; | |
1da177e4 | 4849 | |
95402b38 | 4850 | get_online_cpus(); |
23f5d142 | 4851 | rcu_read_lock(); |
1da177e4 LT |
4852 | |
4853 | p = find_process_by_pid(pid); | |
4854 | if (!p) { | |
23f5d142 | 4855 | rcu_read_unlock(); |
95402b38 | 4856 | put_online_cpus(); |
1da177e4 LT |
4857 | return -ESRCH; |
4858 | } | |
4859 | ||
23f5d142 | 4860 | /* Prevent p going away */ |
1da177e4 | 4861 | get_task_struct(p); |
23f5d142 | 4862 | rcu_read_unlock(); |
1da177e4 | 4863 | |
5a16f3d3 RR |
4864 | if (!alloc_cpumask_var(&cpus_allowed, GFP_KERNEL)) { |
4865 | retval = -ENOMEM; | |
4866 | goto out_put_task; | |
4867 | } | |
4868 | if (!alloc_cpumask_var(&new_mask, GFP_KERNEL)) { | |
4869 | retval = -ENOMEM; | |
4870 | goto out_free_cpus_allowed; | |
4871 | } | |
1da177e4 | 4872 | retval = -EPERM; |
c69e8d9c | 4873 | if (!check_same_owner(p) && !capable(CAP_SYS_NICE)) |
1da177e4 LT |
4874 | goto out_unlock; |
4875 | ||
e7834f8f DQ |
4876 | retval = security_task_setscheduler(p, 0, NULL); |
4877 | if (retval) | |
4878 | goto out_unlock; | |
4879 | ||
5a16f3d3 RR |
4880 | cpuset_cpus_allowed(p, cpus_allowed); |
4881 | cpumask_and(new_mask, in_mask, cpus_allowed); | |
8707d8b8 | 4882 | again: |
5a16f3d3 | 4883 | retval = set_cpus_allowed_ptr(p, new_mask); |
1da177e4 | 4884 | |
8707d8b8 | 4885 | if (!retval) { |
5a16f3d3 RR |
4886 | cpuset_cpus_allowed(p, cpus_allowed); |
4887 | if (!cpumask_subset(new_mask, cpus_allowed)) { | |
8707d8b8 PM |
4888 | /* |
4889 | * We must have raced with a concurrent cpuset | |
4890 | * update. Just reset the cpus_allowed to the | |
4891 | * cpuset's cpus_allowed | |
4892 | */ | |
5a16f3d3 | 4893 | cpumask_copy(new_mask, cpus_allowed); |
8707d8b8 PM |
4894 | goto again; |
4895 | } | |
4896 | } | |
1da177e4 | 4897 | out_unlock: |
5a16f3d3 RR |
4898 | free_cpumask_var(new_mask); |
4899 | out_free_cpus_allowed: | |
4900 | free_cpumask_var(cpus_allowed); | |
4901 | out_put_task: | |
1da177e4 | 4902 | put_task_struct(p); |
95402b38 | 4903 | put_online_cpus(); |
1da177e4 LT |
4904 | return retval; |
4905 | } | |
4906 | ||
4907 | static int get_user_cpu_mask(unsigned long __user *user_mask_ptr, unsigned len, | |
96f874e2 | 4908 | struct cpumask *new_mask) |
1da177e4 | 4909 | { |
96f874e2 RR |
4910 | if (len < cpumask_size()) |
4911 | cpumask_clear(new_mask); | |
4912 | else if (len > cpumask_size()) | |
4913 | len = cpumask_size(); | |
4914 | ||
1da177e4 LT |
4915 | return copy_from_user(new_mask, user_mask_ptr, len) ? -EFAULT : 0; |
4916 | } | |
4917 | ||
4918 | /** | |
4919 | * sys_sched_setaffinity - set the cpu affinity of a process | |
4920 | * @pid: pid of the process | |
4921 | * @len: length in bytes of the bitmask pointed to by user_mask_ptr | |
4922 | * @user_mask_ptr: user-space pointer to the new cpu mask | |
4923 | */ | |
5add95d4 HC |
4924 | SYSCALL_DEFINE3(sched_setaffinity, pid_t, pid, unsigned int, len, |
4925 | unsigned long __user *, user_mask_ptr) | |
1da177e4 | 4926 | { |
5a16f3d3 | 4927 | cpumask_var_t new_mask; |
1da177e4 LT |
4928 | int retval; |
4929 | ||
5a16f3d3 RR |
4930 | if (!alloc_cpumask_var(&new_mask, GFP_KERNEL)) |
4931 | return -ENOMEM; | |
1da177e4 | 4932 | |
5a16f3d3 RR |
4933 | retval = get_user_cpu_mask(user_mask_ptr, len, new_mask); |
4934 | if (retval == 0) | |
4935 | retval = sched_setaffinity(pid, new_mask); | |
4936 | free_cpumask_var(new_mask); | |
4937 | return retval; | |
1da177e4 LT |
4938 | } |
4939 | ||
96f874e2 | 4940 | long sched_getaffinity(pid_t pid, struct cpumask *mask) |
1da177e4 | 4941 | { |
36c8b586 | 4942 | struct task_struct *p; |
31605683 TG |
4943 | unsigned long flags; |
4944 | struct rq *rq; | |
1da177e4 | 4945 | int retval; |
1da177e4 | 4946 | |
95402b38 | 4947 | get_online_cpus(); |
23f5d142 | 4948 | rcu_read_lock(); |
1da177e4 LT |
4949 | |
4950 | retval = -ESRCH; | |
4951 | p = find_process_by_pid(pid); | |
4952 | if (!p) | |
4953 | goto out_unlock; | |
4954 | ||
e7834f8f DQ |
4955 | retval = security_task_getscheduler(p); |
4956 | if (retval) | |
4957 | goto out_unlock; | |
4958 | ||
31605683 | 4959 | rq = task_rq_lock(p, &flags); |
96f874e2 | 4960 | cpumask_and(mask, &p->cpus_allowed, cpu_online_mask); |
31605683 | 4961 | task_rq_unlock(rq, &flags); |
1da177e4 LT |
4962 | |
4963 | out_unlock: | |
23f5d142 | 4964 | rcu_read_unlock(); |
95402b38 | 4965 | put_online_cpus(); |
1da177e4 | 4966 | |
9531b62f | 4967 | return retval; |
1da177e4 LT |
4968 | } |
4969 | ||
4970 | /** | |
4971 | * sys_sched_getaffinity - get the cpu affinity of a process | |
4972 | * @pid: pid of the process | |
4973 | * @len: length in bytes of the bitmask pointed to by user_mask_ptr | |
4974 | * @user_mask_ptr: user-space pointer to hold the current cpu mask | |
4975 | */ | |
5add95d4 HC |
4976 | SYSCALL_DEFINE3(sched_getaffinity, pid_t, pid, unsigned int, len, |
4977 | unsigned long __user *, user_mask_ptr) | |
1da177e4 LT |
4978 | { |
4979 | int ret; | |
f17c8607 | 4980 | cpumask_var_t mask; |
1da177e4 | 4981 | |
84fba5ec | 4982 | if ((len * BITS_PER_BYTE) < nr_cpu_ids) |
cd3d8031 KM |
4983 | return -EINVAL; |
4984 | if (len & (sizeof(unsigned long)-1)) | |
1da177e4 LT |
4985 | return -EINVAL; |
4986 | ||
f17c8607 RR |
4987 | if (!alloc_cpumask_var(&mask, GFP_KERNEL)) |
4988 | return -ENOMEM; | |
1da177e4 | 4989 | |
f17c8607 RR |
4990 | ret = sched_getaffinity(pid, mask); |
4991 | if (ret == 0) { | |
8bc037fb | 4992 | size_t retlen = min_t(size_t, len, cpumask_size()); |
cd3d8031 KM |
4993 | |
4994 | if (copy_to_user(user_mask_ptr, mask, retlen)) | |
f17c8607 RR |
4995 | ret = -EFAULT; |
4996 | else | |
cd3d8031 | 4997 | ret = retlen; |
f17c8607 RR |
4998 | } |
4999 | free_cpumask_var(mask); | |
1da177e4 | 5000 | |
f17c8607 | 5001 | return ret; |
1da177e4 LT |
5002 | } |
5003 | ||
5004 | /** | |
5005 | * sys_sched_yield - yield the current processor to other threads. | |
5006 | * | |
dd41f596 IM |
5007 | * This function yields the current CPU to other tasks. If there are no |
5008 | * other threads running on this CPU then this function will return. | |
1da177e4 | 5009 | */ |
5add95d4 | 5010 | SYSCALL_DEFINE0(sched_yield) |
1da177e4 | 5011 | { |
70b97a7f | 5012 | struct rq *rq = this_rq_lock(); |
1da177e4 | 5013 | |
2d72376b | 5014 | schedstat_inc(rq, yld_count); |
4530d7ab | 5015 | current->sched_class->yield_task(rq); |
1da177e4 LT |
5016 | |
5017 | /* | |
5018 | * Since we are going to call schedule() anyway, there's | |
5019 | * no need to preempt or enable interrupts: | |
5020 | */ | |
5021 | __release(rq->lock); | |
8a25d5de | 5022 | spin_release(&rq->lock.dep_map, 1, _THIS_IP_); |
9828ea9d | 5023 | do_raw_spin_unlock(&rq->lock); |
1da177e4 LT |
5024 | preempt_enable_no_resched(); |
5025 | ||
5026 | schedule(); | |
5027 | ||
5028 | return 0; | |
5029 | } | |
5030 | ||
d86ee480 PZ |
5031 | static inline int should_resched(void) |
5032 | { | |
5033 | return need_resched() && !(preempt_count() & PREEMPT_ACTIVE); | |
5034 | } | |
5035 | ||
e7b38404 | 5036 | static void __cond_resched(void) |
1da177e4 | 5037 | { |
e7aaaa69 FW |
5038 | add_preempt_count(PREEMPT_ACTIVE); |
5039 | schedule(); | |
5040 | sub_preempt_count(PREEMPT_ACTIVE); | |
1da177e4 LT |
5041 | } |
5042 | ||
02b67cc3 | 5043 | int __sched _cond_resched(void) |
1da177e4 | 5044 | { |
d86ee480 | 5045 | if (should_resched()) { |
1da177e4 LT |
5046 | __cond_resched(); |
5047 | return 1; | |
5048 | } | |
5049 | return 0; | |
5050 | } | |
02b67cc3 | 5051 | EXPORT_SYMBOL(_cond_resched); |
1da177e4 LT |
5052 | |
5053 | /* | |
613afbf8 | 5054 | * __cond_resched_lock() - if a reschedule is pending, drop the given lock, |
1da177e4 LT |
5055 | * call schedule, and on return reacquire the lock. |
5056 | * | |
41a2d6cf | 5057 | * This works OK both with and without CONFIG_PREEMPT. We do strange low-level |
1da177e4 LT |
5058 | * operations here to prevent schedule() from being called twice (once via |
5059 | * spin_unlock(), once by hand). | |
5060 | */ | |
613afbf8 | 5061 | int __cond_resched_lock(spinlock_t *lock) |
1da177e4 | 5062 | { |
d86ee480 | 5063 | int resched = should_resched(); |
6df3cecb JK |
5064 | int ret = 0; |
5065 | ||
f607c668 PZ |
5066 | lockdep_assert_held(lock); |
5067 | ||
95c354fe | 5068 | if (spin_needbreak(lock) || resched) { |
1da177e4 | 5069 | spin_unlock(lock); |
d86ee480 | 5070 | if (resched) |
95c354fe NP |
5071 | __cond_resched(); |
5072 | else | |
5073 | cpu_relax(); | |
6df3cecb | 5074 | ret = 1; |
1da177e4 | 5075 | spin_lock(lock); |
1da177e4 | 5076 | } |
6df3cecb | 5077 | return ret; |
1da177e4 | 5078 | } |
613afbf8 | 5079 | EXPORT_SYMBOL(__cond_resched_lock); |
1da177e4 | 5080 | |
613afbf8 | 5081 | int __sched __cond_resched_softirq(void) |
1da177e4 LT |
5082 | { |
5083 | BUG_ON(!in_softirq()); | |
5084 | ||
d86ee480 | 5085 | if (should_resched()) { |
98d82567 | 5086 | local_bh_enable(); |
1da177e4 LT |
5087 | __cond_resched(); |
5088 | local_bh_disable(); | |
5089 | return 1; | |
5090 | } | |
5091 | return 0; | |
5092 | } | |
613afbf8 | 5093 | EXPORT_SYMBOL(__cond_resched_softirq); |
1da177e4 | 5094 | |
1da177e4 LT |
5095 | /** |
5096 | * yield - yield the current processor to other threads. | |
5097 | * | |
72fd4a35 | 5098 | * This is a shortcut for kernel-space yielding - it marks the |
1da177e4 LT |
5099 | * thread runnable and calls sys_sched_yield(). |
5100 | */ | |
5101 | void __sched yield(void) | |
5102 | { | |
5103 | set_current_state(TASK_RUNNING); | |
5104 | sys_sched_yield(); | |
5105 | } | |
1da177e4 LT |
5106 | EXPORT_SYMBOL(yield); |
5107 | ||
5108 | /* | |
41a2d6cf | 5109 | * This task is about to go to sleep on IO. Increment rq->nr_iowait so |
1da177e4 | 5110 | * that process accounting knows that this is a task in IO wait state. |
1da177e4 LT |
5111 | */ |
5112 | void __sched io_schedule(void) | |
5113 | { | |
54d35f29 | 5114 | struct rq *rq = raw_rq(); |
1da177e4 | 5115 | |
0ff92245 | 5116 | delayacct_blkio_start(); |
1da177e4 | 5117 | atomic_inc(&rq->nr_iowait); |
8f0dfc34 | 5118 | current->in_iowait = 1; |
1da177e4 | 5119 | schedule(); |
8f0dfc34 | 5120 | current->in_iowait = 0; |
1da177e4 | 5121 | atomic_dec(&rq->nr_iowait); |
0ff92245 | 5122 | delayacct_blkio_end(); |
1da177e4 | 5123 | } |
1da177e4 LT |
5124 | EXPORT_SYMBOL(io_schedule); |
5125 | ||
5126 | long __sched io_schedule_timeout(long timeout) | |
5127 | { | |
54d35f29 | 5128 | struct rq *rq = raw_rq(); |
1da177e4 LT |
5129 | long ret; |
5130 | ||
0ff92245 | 5131 | delayacct_blkio_start(); |
1da177e4 | 5132 | atomic_inc(&rq->nr_iowait); |
8f0dfc34 | 5133 | current->in_iowait = 1; |
1da177e4 | 5134 | ret = schedule_timeout(timeout); |
8f0dfc34 | 5135 | current->in_iowait = 0; |
1da177e4 | 5136 | atomic_dec(&rq->nr_iowait); |
0ff92245 | 5137 | delayacct_blkio_end(); |
1da177e4 LT |
5138 | return ret; |
5139 | } | |
5140 | ||
5141 | /** | |
5142 | * sys_sched_get_priority_max - return maximum RT priority. | |
5143 | * @policy: scheduling class. | |
5144 | * | |
5145 | * this syscall returns the maximum rt_priority that can be used | |
5146 | * by a given scheduling class. | |
5147 | */ | |
5add95d4 | 5148 | SYSCALL_DEFINE1(sched_get_priority_max, int, policy) |
1da177e4 LT |
5149 | { |
5150 | int ret = -EINVAL; | |
5151 | ||
5152 | switch (policy) { | |
5153 | case SCHED_FIFO: | |
5154 | case SCHED_RR: | |
5155 | ret = MAX_USER_RT_PRIO-1; | |
5156 | break; | |
5157 | case SCHED_NORMAL: | |
b0a9499c | 5158 | case SCHED_BATCH: |
dd41f596 | 5159 | case SCHED_IDLE: |
1da177e4 LT |
5160 | ret = 0; |
5161 | break; | |
5162 | } | |
5163 | return ret; | |
5164 | } | |
5165 | ||
5166 | /** | |
5167 | * sys_sched_get_priority_min - return minimum RT priority. | |
5168 | * @policy: scheduling class. | |
5169 | * | |
5170 | * this syscall returns the minimum rt_priority that can be used | |
5171 | * by a given scheduling class. | |
5172 | */ | |
5add95d4 | 5173 | SYSCALL_DEFINE1(sched_get_priority_min, int, policy) |
1da177e4 LT |
5174 | { |
5175 | int ret = -EINVAL; | |
5176 | ||
5177 | switch (policy) { | |
5178 | case SCHED_FIFO: | |
5179 | case SCHED_RR: | |
5180 | ret = 1; | |
5181 | break; | |
5182 | case SCHED_NORMAL: | |
b0a9499c | 5183 | case SCHED_BATCH: |
dd41f596 | 5184 | case SCHED_IDLE: |
1da177e4 LT |
5185 | ret = 0; |
5186 | } | |
5187 | return ret; | |
5188 | } | |
5189 | ||
5190 | /** | |
5191 | * sys_sched_rr_get_interval - return the default timeslice of a process. | |
5192 | * @pid: pid of the process. | |
5193 | * @interval: userspace pointer to the timeslice value. | |
5194 | * | |
5195 | * this syscall writes the default timeslice value of a given process | |
5196 | * into the user-space timespec buffer. A value of '0' means infinity. | |
5197 | */ | |
17da2bd9 | 5198 | SYSCALL_DEFINE2(sched_rr_get_interval, pid_t, pid, |
754fe8d2 | 5199 | struct timespec __user *, interval) |
1da177e4 | 5200 | { |
36c8b586 | 5201 | struct task_struct *p; |
a4ec24b4 | 5202 | unsigned int time_slice; |
dba091b9 TG |
5203 | unsigned long flags; |
5204 | struct rq *rq; | |
3a5c359a | 5205 | int retval; |
1da177e4 | 5206 | struct timespec t; |
1da177e4 LT |
5207 | |
5208 | if (pid < 0) | |
3a5c359a | 5209 | return -EINVAL; |
1da177e4 LT |
5210 | |
5211 | retval = -ESRCH; | |
1a551ae7 | 5212 | rcu_read_lock(); |
1da177e4 LT |
5213 | p = find_process_by_pid(pid); |
5214 | if (!p) | |
5215 | goto out_unlock; | |
5216 | ||
5217 | retval = security_task_getscheduler(p); | |
5218 | if (retval) | |
5219 | goto out_unlock; | |
5220 | ||
dba091b9 TG |
5221 | rq = task_rq_lock(p, &flags); |
5222 | time_slice = p->sched_class->get_rr_interval(rq, p); | |
5223 | task_rq_unlock(rq, &flags); | |
a4ec24b4 | 5224 | |
1a551ae7 | 5225 | rcu_read_unlock(); |
a4ec24b4 | 5226 | jiffies_to_timespec(time_slice, &t); |
1da177e4 | 5227 | retval = copy_to_user(interval, &t, sizeof(t)) ? -EFAULT : 0; |
1da177e4 | 5228 | return retval; |
3a5c359a | 5229 | |
1da177e4 | 5230 | out_unlock: |
1a551ae7 | 5231 | rcu_read_unlock(); |
1da177e4 LT |
5232 | return retval; |
5233 | } | |
5234 | ||
7c731e0a | 5235 | static const char stat_nam[] = TASK_STATE_TO_CHAR_STR; |
36c8b586 | 5236 | |
82a1fcb9 | 5237 | void sched_show_task(struct task_struct *p) |
1da177e4 | 5238 | { |
1da177e4 | 5239 | unsigned long free = 0; |
36c8b586 | 5240 | unsigned state; |
1da177e4 | 5241 | |
1da177e4 | 5242 | state = p->state ? __ffs(p->state) + 1 : 0; |
3df0fc5b | 5243 | printk(KERN_INFO "%-13.13s %c", p->comm, |
2ed6e34f | 5244 | state < sizeof(stat_nam) - 1 ? stat_nam[state] : '?'); |
4bd77321 | 5245 | #if BITS_PER_LONG == 32 |
1da177e4 | 5246 | if (state == TASK_RUNNING) |
3df0fc5b | 5247 | printk(KERN_CONT " running "); |
1da177e4 | 5248 | else |
3df0fc5b | 5249 | printk(KERN_CONT " %08lx ", thread_saved_pc(p)); |
1da177e4 LT |
5250 | #else |
5251 | if (state == TASK_RUNNING) | |
3df0fc5b | 5252 | printk(KERN_CONT " running task "); |
1da177e4 | 5253 | else |
3df0fc5b | 5254 | printk(KERN_CONT " %016lx ", thread_saved_pc(p)); |
1da177e4 LT |
5255 | #endif |
5256 | #ifdef CONFIG_DEBUG_STACK_USAGE | |
7c9f8861 | 5257 | free = stack_not_used(p); |
1da177e4 | 5258 | #endif |
3df0fc5b | 5259 | printk(KERN_CONT "%5lu %5d %6d 0x%08lx\n", free, |
aa47b7e0 DR |
5260 | task_pid_nr(p), task_pid_nr(p->real_parent), |
5261 | (unsigned long)task_thread_info(p)->flags); | |
1da177e4 | 5262 | |
5fb5e6de | 5263 | show_stack(p, NULL); |
1da177e4 LT |
5264 | } |
5265 | ||
e59e2ae2 | 5266 | void show_state_filter(unsigned long state_filter) |
1da177e4 | 5267 | { |
36c8b586 | 5268 | struct task_struct *g, *p; |
1da177e4 | 5269 | |
4bd77321 | 5270 | #if BITS_PER_LONG == 32 |
3df0fc5b PZ |
5271 | printk(KERN_INFO |
5272 | " task PC stack pid father\n"); | |
1da177e4 | 5273 | #else |
3df0fc5b PZ |
5274 | printk(KERN_INFO |
5275 | " task PC stack pid father\n"); | |
1da177e4 LT |
5276 | #endif |
5277 | read_lock(&tasklist_lock); | |
5278 | do_each_thread(g, p) { | |
5279 | /* | |
5280 | * reset the NMI-timeout, listing all files on a slow | |
5281 | * console might take alot of time: | |
5282 | */ | |
5283 | touch_nmi_watchdog(); | |
39bc89fd | 5284 | if (!state_filter || (p->state & state_filter)) |
82a1fcb9 | 5285 | sched_show_task(p); |
1da177e4 LT |
5286 | } while_each_thread(g, p); |
5287 | ||
04c9167f JF |
5288 | touch_all_softlockup_watchdogs(); |
5289 | ||
dd41f596 IM |
5290 | #ifdef CONFIG_SCHED_DEBUG |
5291 | sysrq_sched_debug_show(); | |
5292 | #endif | |
1da177e4 | 5293 | read_unlock(&tasklist_lock); |
e59e2ae2 IM |
5294 | /* |
5295 | * Only show locks if all tasks are dumped: | |
5296 | */ | |
93335a21 | 5297 | if (!state_filter) |
e59e2ae2 | 5298 | debug_show_all_locks(); |
1da177e4 LT |
5299 | } |
5300 | ||
1df21055 IM |
5301 | void __cpuinit init_idle_bootup_task(struct task_struct *idle) |
5302 | { | |
dd41f596 | 5303 | idle->sched_class = &idle_sched_class; |
1df21055 IM |
5304 | } |
5305 | ||
f340c0d1 IM |
5306 | /** |
5307 | * init_idle - set up an idle thread for a given CPU | |
5308 | * @idle: task in question | |
5309 | * @cpu: cpu the idle task belongs to | |
5310 | * | |
5311 | * NOTE: this function does not set the idle thread's NEED_RESCHED | |
5312 | * flag, to make booting more robust. | |
5313 | */ | |
5c1e1767 | 5314 | void __cpuinit init_idle(struct task_struct *idle, int cpu) |
1da177e4 | 5315 | { |
70b97a7f | 5316 | struct rq *rq = cpu_rq(cpu); |
1da177e4 LT |
5317 | unsigned long flags; |
5318 | ||
05fa785c | 5319 | raw_spin_lock_irqsave(&rq->lock, flags); |
5cbd54ef | 5320 | |
dd41f596 | 5321 | __sched_fork(idle); |
06b83b5f | 5322 | idle->state = TASK_RUNNING; |
dd41f596 IM |
5323 | idle->se.exec_start = sched_clock(); |
5324 | ||
96f874e2 | 5325 | cpumask_copy(&idle->cpus_allowed, cpumask_of(cpu)); |
dd41f596 | 5326 | __set_task_cpu(idle, cpu); |
1da177e4 | 5327 | |
1da177e4 | 5328 | rq->curr = rq->idle = idle; |
4866cde0 NP |
5329 | #if defined(CONFIG_SMP) && defined(__ARCH_WANT_UNLOCKED_CTXSW) |
5330 | idle->oncpu = 1; | |
5331 | #endif | |
05fa785c | 5332 | raw_spin_unlock_irqrestore(&rq->lock, flags); |
1da177e4 LT |
5333 | |
5334 | /* Set the preempt count _outside_ the spinlocks! */ | |
8e3e076c LT |
5335 | #if defined(CONFIG_PREEMPT) |
5336 | task_thread_info(idle)->preempt_count = (idle->lock_depth >= 0); | |
5337 | #else | |
a1261f54 | 5338 | task_thread_info(idle)->preempt_count = 0; |
8e3e076c | 5339 | #endif |
dd41f596 IM |
5340 | /* |
5341 | * The idle tasks have their own, simple scheduling class: | |
5342 | */ | |
5343 | idle->sched_class = &idle_sched_class; | |
fb52607a | 5344 | ftrace_graph_init_task(idle); |
1da177e4 LT |
5345 | } |
5346 | ||
5347 | /* | |
5348 | * In a system that switches off the HZ timer nohz_cpu_mask | |
5349 | * indicates which cpus entered this state. This is used | |
5350 | * in the rcu update to wait only for active cpus. For system | |
5351 | * which do not switch off the HZ timer nohz_cpu_mask should | |
6a7b3dc3 | 5352 | * always be CPU_BITS_NONE. |
1da177e4 | 5353 | */ |
6a7b3dc3 | 5354 | cpumask_var_t nohz_cpu_mask; |
1da177e4 | 5355 | |
19978ca6 IM |
5356 | /* |
5357 | * Increase the granularity value when there are more CPUs, | |
5358 | * because with more CPUs the 'effective latency' as visible | |
5359 | * to users decreases. But the relationship is not linear, | |
5360 | * so pick a second-best guess by going with the log2 of the | |
5361 | * number of CPUs. | |
5362 | * | |
5363 | * This idea comes from the SD scheduler of Con Kolivas: | |
5364 | */ | |
acb4a848 | 5365 | static int get_update_sysctl_factor(void) |
19978ca6 | 5366 | { |
4ca3ef71 | 5367 | unsigned int cpus = min_t(int, num_online_cpus(), 8); |
1983a922 CE |
5368 | unsigned int factor; |
5369 | ||
5370 | switch (sysctl_sched_tunable_scaling) { | |
5371 | case SCHED_TUNABLESCALING_NONE: | |
5372 | factor = 1; | |
5373 | break; | |
5374 | case SCHED_TUNABLESCALING_LINEAR: | |
5375 | factor = cpus; | |
5376 | break; | |
5377 | case SCHED_TUNABLESCALING_LOG: | |
5378 | default: | |
5379 | factor = 1 + ilog2(cpus); | |
5380 | break; | |
5381 | } | |
19978ca6 | 5382 | |
acb4a848 CE |
5383 | return factor; |
5384 | } | |
19978ca6 | 5385 | |
acb4a848 CE |
5386 | static void update_sysctl(void) |
5387 | { | |
5388 | unsigned int factor = get_update_sysctl_factor(); | |
19978ca6 | 5389 | |
0bcdcf28 CE |
5390 | #define SET_SYSCTL(name) \ |
5391 | (sysctl_##name = (factor) * normalized_sysctl_##name) | |
5392 | SET_SYSCTL(sched_min_granularity); | |
5393 | SET_SYSCTL(sched_latency); | |
5394 | SET_SYSCTL(sched_wakeup_granularity); | |
5395 | SET_SYSCTL(sched_shares_ratelimit); | |
5396 | #undef SET_SYSCTL | |
5397 | } | |
55cd5340 | 5398 | |
0bcdcf28 CE |
5399 | static inline void sched_init_granularity(void) |
5400 | { | |
5401 | update_sysctl(); | |
19978ca6 IM |
5402 | } |
5403 | ||
1da177e4 LT |
5404 | #ifdef CONFIG_SMP |
5405 | /* | |
5406 | * This is how migration works: | |
5407 | * | |
969c7921 TH |
5408 | * 1) we invoke migration_cpu_stop() on the target CPU using |
5409 | * stop_one_cpu(). | |
5410 | * 2) stopper starts to run (implicitly forcing the migrated thread | |
5411 | * off the CPU) | |
5412 | * 3) it checks whether the migrated task is still in the wrong runqueue. | |
5413 | * 4) if it's in the wrong runqueue then the migration thread removes | |
1da177e4 | 5414 | * it and puts it into the right queue. |
969c7921 TH |
5415 | * 5) stopper completes and stop_one_cpu() returns and the migration |
5416 | * is done. | |
1da177e4 LT |
5417 | */ |
5418 | ||
5419 | /* | |
5420 | * Change a given task's CPU affinity. Migrate the thread to a | |
5421 | * proper CPU and schedule it away if the CPU it's executing on | |
5422 | * is removed from the allowed bitmask. | |
5423 | * | |
5424 | * NOTE: the caller must have a valid reference to the task, the | |
41a2d6cf | 5425 | * task must not exit() & deallocate itself prematurely. The |
1da177e4 LT |
5426 | * call is not atomic; no spinlocks may be held. |
5427 | */ | |
96f874e2 | 5428 | int set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask) |
1da177e4 LT |
5429 | { |
5430 | unsigned long flags; | |
70b97a7f | 5431 | struct rq *rq; |
969c7921 | 5432 | unsigned int dest_cpu; |
48f24c4d | 5433 | int ret = 0; |
1da177e4 | 5434 | |
65cc8e48 PZ |
5435 | /* |
5436 | * Serialize against TASK_WAKING so that ttwu() and wunt() can | |
5437 | * drop the rq->lock and still rely on ->cpus_allowed. | |
5438 | */ | |
5439 | again: | |
5440 | while (task_is_waking(p)) | |
5441 | cpu_relax(); | |
1da177e4 | 5442 | rq = task_rq_lock(p, &flags); |
65cc8e48 PZ |
5443 | if (task_is_waking(p)) { |
5444 | task_rq_unlock(rq, &flags); | |
5445 | goto again; | |
5446 | } | |
e2912009 | 5447 | |
6ad4c188 | 5448 | if (!cpumask_intersects(new_mask, cpu_active_mask)) { |
1da177e4 LT |
5449 | ret = -EINVAL; |
5450 | goto out; | |
5451 | } | |
5452 | ||
9985b0ba | 5453 | if (unlikely((p->flags & PF_THREAD_BOUND) && p != current && |
96f874e2 | 5454 | !cpumask_equal(&p->cpus_allowed, new_mask))) { |
9985b0ba DR |
5455 | ret = -EINVAL; |
5456 | goto out; | |
5457 | } | |
5458 | ||
73fe6aae | 5459 | if (p->sched_class->set_cpus_allowed) |
cd8ba7cd | 5460 | p->sched_class->set_cpus_allowed(p, new_mask); |
73fe6aae | 5461 | else { |
96f874e2 RR |
5462 | cpumask_copy(&p->cpus_allowed, new_mask); |
5463 | p->rt.nr_cpus_allowed = cpumask_weight(new_mask); | |
73fe6aae GH |
5464 | } |
5465 | ||
1da177e4 | 5466 | /* Can the task run on the task's current CPU? If so, we're done */ |
96f874e2 | 5467 | if (cpumask_test_cpu(task_cpu(p), new_mask)) |
1da177e4 LT |
5468 | goto out; |
5469 | ||
969c7921 TH |
5470 | dest_cpu = cpumask_any_and(cpu_active_mask, new_mask); |
5471 | if (migrate_task(p, dest_cpu)) { | |
5472 | struct migration_arg arg = { p, dest_cpu }; | |
1da177e4 LT |
5473 | /* Need help from migration thread: drop lock and wait. */ |
5474 | task_rq_unlock(rq, &flags); | |
969c7921 | 5475 | stop_one_cpu(cpu_of(rq), migration_cpu_stop, &arg); |
1da177e4 LT |
5476 | tlb_migrate_finish(p->mm); |
5477 | return 0; | |
5478 | } | |
5479 | out: | |
5480 | task_rq_unlock(rq, &flags); | |
48f24c4d | 5481 | |
1da177e4 LT |
5482 | return ret; |
5483 | } | |
cd8ba7cd | 5484 | EXPORT_SYMBOL_GPL(set_cpus_allowed_ptr); |
1da177e4 LT |
5485 | |
5486 | /* | |
41a2d6cf | 5487 | * Move (not current) task off this cpu, onto dest cpu. We're doing |
1da177e4 LT |
5488 | * this because either it can't run here any more (set_cpus_allowed() |
5489 | * away from this CPU, or CPU going down), or because we're | |
5490 | * attempting to rebalance this task on exec (sched_exec). | |
5491 | * | |
5492 | * So we race with normal scheduler movements, but that's OK, as long | |
5493 | * as the task is no longer on this CPU. | |
efc30814 KK |
5494 | * |
5495 | * Returns non-zero if task was successfully migrated. | |
1da177e4 | 5496 | */ |
efc30814 | 5497 | static int __migrate_task(struct task_struct *p, int src_cpu, int dest_cpu) |
1da177e4 | 5498 | { |
70b97a7f | 5499 | struct rq *rq_dest, *rq_src; |
e2912009 | 5500 | int ret = 0; |
1da177e4 | 5501 | |
e761b772 | 5502 | if (unlikely(!cpu_active(dest_cpu))) |
efc30814 | 5503 | return ret; |
1da177e4 LT |
5504 | |
5505 | rq_src = cpu_rq(src_cpu); | |
5506 | rq_dest = cpu_rq(dest_cpu); | |
5507 | ||
5508 | double_rq_lock(rq_src, rq_dest); | |
5509 | /* Already moved. */ | |
5510 | if (task_cpu(p) != src_cpu) | |
b1e38734 | 5511 | goto done; |
1da177e4 | 5512 | /* Affinity changed (again). */ |
96f874e2 | 5513 | if (!cpumask_test_cpu(dest_cpu, &p->cpus_allowed)) |
b1e38734 | 5514 | goto fail; |
1da177e4 | 5515 | |
e2912009 PZ |
5516 | /* |
5517 | * If we're not on a rq, the next wake-up will ensure we're | |
5518 | * placed properly. | |
5519 | */ | |
5520 | if (p->se.on_rq) { | |
2e1cb74a | 5521 | deactivate_task(rq_src, p, 0); |
e2912009 | 5522 | set_task_cpu(p, dest_cpu); |
dd41f596 | 5523 | activate_task(rq_dest, p, 0); |
15afe09b | 5524 | check_preempt_curr(rq_dest, p, 0); |
1da177e4 | 5525 | } |
b1e38734 | 5526 | done: |
efc30814 | 5527 | ret = 1; |
b1e38734 | 5528 | fail: |
1da177e4 | 5529 | double_rq_unlock(rq_src, rq_dest); |
efc30814 | 5530 | return ret; |
1da177e4 LT |
5531 | } |
5532 | ||
5533 | /* | |
969c7921 TH |
5534 | * migration_cpu_stop - this will be executed by a highprio stopper thread |
5535 | * and performs thread migration by bumping thread off CPU then | |
5536 | * 'pushing' onto another runqueue. | |
1da177e4 | 5537 | */ |
969c7921 | 5538 | static int migration_cpu_stop(void *data) |
1da177e4 | 5539 | { |
969c7921 | 5540 | struct migration_arg *arg = data; |
f7b4cddc | 5541 | |
969c7921 TH |
5542 | /* |
5543 | * The original target cpu might have gone down and we might | |
5544 | * be on another cpu but it doesn't matter. | |
5545 | */ | |
f7b4cddc | 5546 | local_irq_disable(); |
969c7921 | 5547 | __migrate_task(arg->task, raw_smp_processor_id(), arg->dest_cpu); |
f7b4cddc | 5548 | local_irq_enable(); |
1da177e4 | 5549 | return 0; |
f7b4cddc ON |
5550 | } |
5551 | ||
1da177e4 | 5552 | #ifdef CONFIG_HOTPLUG_CPU |
054b9108 | 5553 | /* |
3a4fa0a2 | 5554 | * Figure out where task on dead CPU should go, use force if necessary. |
054b9108 | 5555 | */ |
6a1bdc1b | 5556 | void move_task_off_dead_cpu(int dead_cpu, struct task_struct *p) |
1da177e4 | 5557 | { |
1445c08d ON |
5558 | struct rq *rq = cpu_rq(dead_cpu); |
5559 | int needs_cpu, uninitialized_var(dest_cpu); | |
5560 | unsigned long flags; | |
e76bd8d9 | 5561 | |
1445c08d | 5562 | local_irq_save(flags); |
e76bd8d9 | 5563 | |
1445c08d ON |
5564 | raw_spin_lock(&rq->lock); |
5565 | needs_cpu = (task_cpu(p) == dead_cpu) && (p->state != TASK_WAKING); | |
5566 | if (needs_cpu) | |
5567 | dest_cpu = select_fallback_rq(dead_cpu, p); | |
5568 | raw_spin_unlock(&rq->lock); | |
c1804d54 ON |
5569 | /* |
5570 | * It can only fail if we race with set_cpus_allowed(), | |
5571 | * in the racer should migrate the task anyway. | |
5572 | */ | |
1445c08d | 5573 | if (needs_cpu) |
c1804d54 | 5574 | __migrate_task(p, dead_cpu, dest_cpu); |
1445c08d | 5575 | local_irq_restore(flags); |
1da177e4 LT |
5576 | } |
5577 | ||
5578 | /* | |
5579 | * While a dead CPU has no uninterruptible tasks queued at this point, | |
5580 | * it might still have a nonzero ->nr_uninterruptible counter, because | |
5581 | * for performance reasons the counter is not stricly tracking tasks to | |
5582 | * their home CPUs. So we just add the counter to another CPU's counter, | |
5583 | * to keep the global sum constant after CPU-down: | |
5584 | */ | |
70b97a7f | 5585 | static void migrate_nr_uninterruptible(struct rq *rq_src) |
1da177e4 | 5586 | { |
6ad4c188 | 5587 | struct rq *rq_dest = cpu_rq(cpumask_any(cpu_active_mask)); |
1da177e4 LT |
5588 | unsigned long flags; |
5589 | ||
5590 | local_irq_save(flags); | |
5591 | double_rq_lock(rq_src, rq_dest); | |
5592 | rq_dest->nr_uninterruptible += rq_src->nr_uninterruptible; | |
5593 | rq_src->nr_uninterruptible = 0; | |
5594 | double_rq_unlock(rq_src, rq_dest); | |
5595 | local_irq_restore(flags); | |
5596 | } | |
5597 | ||
5598 | /* Run through task list and migrate tasks from the dead cpu. */ | |
5599 | static void migrate_live_tasks(int src_cpu) | |
5600 | { | |
48f24c4d | 5601 | struct task_struct *p, *t; |
1da177e4 | 5602 | |
f7b4cddc | 5603 | read_lock(&tasklist_lock); |
1da177e4 | 5604 | |
48f24c4d IM |
5605 | do_each_thread(t, p) { |
5606 | if (p == current) | |
1da177e4 LT |
5607 | continue; |
5608 | ||
48f24c4d IM |
5609 | if (task_cpu(p) == src_cpu) |
5610 | move_task_off_dead_cpu(src_cpu, p); | |
5611 | } while_each_thread(t, p); | |
1da177e4 | 5612 | |
f7b4cddc | 5613 | read_unlock(&tasklist_lock); |
1da177e4 LT |
5614 | } |
5615 | ||
dd41f596 IM |
5616 | /* |
5617 | * Schedules idle task to be the next runnable task on current CPU. | |
94bc9a7b DA |
5618 | * It does so by boosting its priority to highest possible. |
5619 | * Used by CPU offline code. | |
1da177e4 LT |
5620 | */ |
5621 | void sched_idle_next(void) | |
5622 | { | |
48f24c4d | 5623 | int this_cpu = smp_processor_id(); |
70b97a7f | 5624 | struct rq *rq = cpu_rq(this_cpu); |
1da177e4 LT |
5625 | struct task_struct *p = rq->idle; |
5626 | unsigned long flags; | |
5627 | ||
5628 | /* cpu has to be offline */ | |
48f24c4d | 5629 | BUG_ON(cpu_online(this_cpu)); |
1da177e4 | 5630 | |
48f24c4d IM |
5631 | /* |
5632 | * Strictly not necessary since rest of the CPUs are stopped by now | |
5633 | * and interrupts disabled on the current cpu. | |
1da177e4 | 5634 | */ |
05fa785c | 5635 | raw_spin_lock_irqsave(&rq->lock, flags); |
1da177e4 | 5636 | |
dd41f596 | 5637 | __setscheduler(rq, p, SCHED_FIFO, MAX_RT_PRIO-1); |
48f24c4d | 5638 | |
94bc9a7b | 5639 | activate_task(rq, p, 0); |
1da177e4 | 5640 | |
05fa785c | 5641 | raw_spin_unlock_irqrestore(&rq->lock, flags); |
1da177e4 LT |
5642 | } |
5643 | ||
48f24c4d IM |
5644 | /* |
5645 | * Ensures that the idle task is using init_mm right before its cpu goes | |
1da177e4 LT |
5646 | * offline. |
5647 | */ | |
5648 | void idle_task_exit(void) | |
5649 | { | |
5650 | struct mm_struct *mm = current->active_mm; | |
5651 | ||
5652 | BUG_ON(cpu_online(smp_processor_id())); | |
5653 | ||
5654 | if (mm != &init_mm) | |
5655 | switch_mm(mm, &init_mm, current); | |
5656 | mmdrop(mm); | |
5657 | } | |
5658 | ||
054b9108 | 5659 | /* called under rq->lock with disabled interrupts */ |
36c8b586 | 5660 | static void migrate_dead(unsigned int dead_cpu, struct task_struct *p) |
1da177e4 | 5661 | { |
70b97a7f | 5662 | struct rq *rq = cpu_rq(dead_cpu); |
1da177e4 LT |
5663 | |
5664 | /* Must be exiting, otherwise would be on tasklist. */ | |
270f722d | 5665 | BUG_ON(!p->exit_state); |
1da177e4 LT |
5666 | |
5667 | /* Cannot have done final schedule yet: would have vanished. */ | |
c394cc9f | 5668 | BUG_ON(p->state == TASK_DEAD); |
1da177e4 | 5669 | |
48f24c4d | 5670 | get_task_struct(p); |
1da177e4 LT |
5671 | |
5672 | /* | |
5673 | * Drop lock around migration; if someone else moves it, | |
41a2d6cf | 5674 | * that's OK. No task can be added to this CPU, so iteration is |
1da177e4 LT |
5675 | * fine. |
5676 | */ | |
05fa785c | 5677 | raw_spin_unlock_irq(&rq->lock); |
48f24c4d | 5678 | move_task_off_dead_cpu(dead_cpu, p); |
05fa785c | 5679 | raw_spin_lock_irq(&rq->lock); |
1da177e4 | 5680 | |
48f24c4d | 5681 | put_task_struct(p); |
1da177e4 LT |
5682 | } |
5683 | ||
5684 | /* release_task() removes task from tasklist, so we won't find dead tasks. */ | |
5685 | static void migrate_dead_tasks(unsigned int dead_cpu) | |
5686 | { | |
70b97a7f | 5687 | struct rq *rq = cpu_rq(dead_cpu); |
dd41f596 | 5688 | struct task_struct *next; |
48f24c4d | 5689 | |
dd41f596 IM |
5690 | for ( ; ; ) { |
5691 | if (!rq->nr_running) | |
5692 | break; | |
b67802ea | 5693 | next = pick_next_task(rq); |
dd41f596 IM |
5694 | if (!next) |
5695 | break; | |
79c53799 | 5696 | next->sched_class->put_prev_task(rq, next); |
dd41f596 | 5697 | migrate_dead(dead_cpu, next); |
e692ab53 | 5698 | |
1da177e4 LT |
5699 | } |
5700 | } | |
dce48a84 TG |
5701 | |
5702 | /* | |
5703 | * remove the tasks which were accounted by rq from calc_load_tasks. | |
5704 | */ | |
5705 | static void calc_global_load_remove(struct rq *rq) | |
5706 | { | |
5707 | atomic_long_sub(rq->calc_load_active, &calc_load_tasks); | |
a468d389 | 5708 | rq->calc_load_active = 0; |
dce48a84 | 5709 | } |
1da177e4 LT |
5710 | #endif /* CONFIG_HOTPLUG_CPU */ |
5711 | ||
e692ab53 NP |
5712 | #if defined(CONFIG_SCHED_DEBUG) && defined(CONFIG_SYSCTL) |
5713 | ||
5714 | static struct ctl_table sd_ctl_dir[] = { | |
e0361851 AD |
5715 | { |
5716 | .procname = "sched_domain", | |
c57baf1e | 5717 | .mode = 0555, |
e0361851 | 5718 | }, |
56992309 | 5719 | {} |
e692ab53 NP |
5720 | }; |
5721 | ||
5722 | static struct ctl_table sd_ctl_root[] = { | |
e0361851 AD |
5723 | { |
5724 | .procname = "kernel", | |
c57baf1e | 5725 | .mode = 0555, |
e0361851 AD |
5726 | .child = sd_ctl_dir, |
5727 | }, | |
56992309 | 5728 | {} |
e692ab53 NP |
5729 | }; |
5730 | ||
5731 | static struct ctl_table *sd_alloc_ctl_entry(int n) | |
5732 | { | |
5733 | struct ctl_table *entry = | |
5cf9f062 | 5734 | kcalloc(n, sizeof(struct ctl_table), GFP_KERNEL); |
e692ab53 | 5735 | |
e692ab53 NP |
5736 | return entry; |
5737 | } | |
5738 | ||
6382bc90 MM |
5739 | static void sd_free_ctl_entry(struct ctl_table **tablep) |
5740 | { | |
cd790076 | 5741 | struct ctl_table *entry; |
6382bc90 | 5742 | |
cd790076 MM |
5743 | /* |
5744 | * In the intermediate directories, both the child directory and | |
5745 | * procname are dynamically allocated and could fail but the mode | |
41a2d6cf | 5746 | * will always be set. In the lowest directory the names are |
cd790076 MM |
5747 | * static strings and all have proc handlers. |
5748 | */ | |
5749 | for (entry = *tablep; entry->mode; entry++) { | |
6382bc90 MM |
5750 | if (entry->child) |
5751 | sd_free_ctl_entry(&entry->child); | |
cd790076 MM |
5752 | if (entry->proc_handler == NULL) |
5753 | kfree(entry->procname); | |
5754 | } | |
6382bc90 MM |
5755 | |
5756 | kfree(*tablep); | |
5757 | *tablep = NULL; | |
5758 | } | |
5759 | ||
e692ab53 | 5760 | static void |
e0361851 | 5761 | set_table_entry(struct ctl_table *entry, |
e692ab53 NP |
5762 | const char *procname, void *data, int maxlen, |
5763 | mode_t mode, proc_handler *proc_handler) | |
5764 | { | |
e692ab53 NP |
5765 | entry->procname = procname; |
5766 | entry->data = data; | |
5767 | entry->maxlen = maxlen; | |
5768 | entry->mode = mode; | |
5769 | entry->proc_handler = proc_handler; | |
5770 | } | |
5771 | ||
5772 | static struct ctl_table * | |
5773 | sd_alloc_ctl_domain_table(struct sched_domain *sd) | |
5774 | { | |
a5d8c348 | 5775 | struct ctl_table *table = sd_alloc_ctl_entry(13); |
e692ab53 | 5776 | |
ad1cdc1d MM |
5777 | if (table == NULL) |
5778 | return NULL; | |
5779 | ||
e0361851 | 5780 | set_table_entry(&table[0], "min_interval", &sd->min_interval, |
e692ab53 | 5781 | sizeof(long), 0644, proc_doulongvec_minmax); |
e0361851 | 5782 | set_table_entry(&table[1], "max_interval", &sd->max_interval, |
e692ab53 | 5783 | sizeof(long), 0644, proc_doulongvec_minmax); |
e0361851 | 5784 | set_table_entry(&table[2], "busy_idx", &sd->busy_idx, |
e692ab53 | 5785 | sizeof(int), 0644, proc_dointvec_minmax); |
e0361851 | 5786 | set_table_entry(&table[3], "idle_idx", &sd->idle_idx, |
e692ab53 | 5787 | sizeof(int), 0644, proc_dointvec_minmax); |
e0361851 | 5788 | set_table_entry(&table[4], "newidle_idx", &sd->newidle_idx, |
e692ab53 | 5789 | sizeof(int), 0644, proc_dointvec_minmax); |
e0361851 | 5790 | set_table_entry(&table[5], "wake_idx", &sd->wake_idx, |
e692ab53 | 5791 | sizeof(int), 0644, proc_dointvec_minmax); |
e0361851 | 5792 | set_table_entry(&table[6], "forkexec_idx", &sd->forkexec_idx, |
e692ab53 | 5793 | sizeof(int), 0644, proc_dointvec_minmax); |
e0361851 | 5794 | set_table_entry(&table[7], "busy_factor", &sd->busy_factor, |
e692ab53 | 5795 | sizeof(int), 0644, proc_dointvec_minmax); |
e0361851 | 5796 | set_table_entry(&table[8], "imbalance_pct", &sd->imbalance_pct, |
e692ab53 | 5797 | sizeof(int), 0644, proc_dointvec_minmax); |
ace8b3d6 | 5798 | set_table_entry(&table[9], "cache_nice_tries", |
e692ab53 NP |
5799 | &sd->cache_nice_tries, |
5800 | sizeof(int), 0644, proc_dointvec_minmax); | |
ace8b3d6 | 5801 | set_table_entry(&table[10], "flags", &sd->flags, |
e692ab53 | 5802 | sizeof(int), 0644, proc_dointvec_minmax); |
a5d8c348 IM |
5803 | set_table_entry(&table[11], "name", sd->name, |
5804 | CORENAME_MAX_SIZE, 0444, proc_dostring); | |
5805 | /* &table[12] is terminator */ | |
e692ab53 NP |
5806 | |
5807 | return table; | |
5808 | } | |
5809 | ||
9a4e7159 | 5810 | static ctl_table *sd_alloc_ctl_cpu_table(int cpu) |
e692ab53 NP |
5811 | { |
5812 | struct ctl_table *entry, *table; | |
5813 | struct sched_domain *sd; | |
5814 | int domain_num = 0, i; | |
5815 | char buf[32]; | |
5816 | ||
5817 | for_each_domain(cpu, sd) | |
5818 | domain_num++; | |
5819 | entry = table = sd_alloc_ctl_entry(domain_num + 1); | |
ad1cdc1d MM |
5820 | if (table == NULL) |
5821 | return NULL; | |
e692ab53 NP |
5822 | |
5823 | i = 0; | |
5824 | for_each_domain(cpu, sd) { | |
5825 | snprintf(buf, 32, "domain%d", i); | |
e692ab53 | 5826 | entry->procname = kstrdup(buf, GFP_KERNEL); |
c57baf1e | 5827 | entry->mode = 0555; |
e692ab53 NP |
5828 | entry->child = sd_alloc_ctl_domain_table(sd); |
5829 | entry++; | |
5830 | i++; | |
5831 | } | |
5832 | return table; | |
5833 | } | |
5834 | ||
5835 | static struct ctl_table_header *sd_sysctl_header; | |
6382bc90 | 5836 | static void register_sched_domain_sysctl(void) |
e692ab53 | 5837 | { |
6ad4c188 | 5838 | int i, cpu_num = num_possible_cpus(); |
e692ab53 NP |
5839 | struct ctl_table *entry = sd_alloc_ctl_entry(cpu_num + 1); |
5840 | char buf[32]; | |
5841 | ||
7378547f MM |
5842 | WARN_ON(sd_ctl_dir[0].child); |
5843 | sd_ctl_dir[0].child = entry; | |
5844 | ||
ad1cdc1d MM |
5845 | if (entry == NULL) |
5846 | return; | |
5847 | ||
6ad4c188 | 5848 | for_each_possible_cpu(i) { |
e692ab53 | 5849 | snprintf(buf, 32, "cpu%d", i); |
e692ab53 | 5850 | entry->procname = kstrdup(buf, GFP_KERNEL); |
c57baf1e | 5851 | entry->mode = 0555; |
e692ab53 | 5852 | entry->child = sd_alloc_ctl_cpu_table(i); |
97b6ea7b | 5853 | entry++; |
e692ab53 | 5854 | } |
7378547f MM |
5855 | |
5856 | WARN_ON(sd_sysctl_header); | |
e692ab53 NP |
5857 | sd_sysctl_header = register_sysctl_table(sd_ctl_root); |
5858 | } | |
6382bc90 | 5859 | |
7378547f | 5860 | /* may be called multiple times per register */ |
6382bc90 MM |
5861 | static void unregister_sched_domain_sysctl(void) |
5862 | { | |
7378547f MM |
5863 | if (sd_sysctl_header) |
5864 | unregister_sysctl_table(sd_sysctl_header); | |
6382bc90 | 5865 | sd_sysctl_header = NULL; |
7378547f MM |
5866 | if (sd_ctl_dir[0].child) |
5867 | sd_free_ctl_entry(&sd_ctl_dir[0].child); | |
6382bc90 | 5868 | } |
e692ab53 | 5869 | #else |
6382bc90 MM |
5870 | static void register_sched_domain_sysctl(void) |
5871 | { | |
5872 | } | |
5873 | static void unregister_sched_domain_sysctl(void) | |
e692ab53 NP |
5874 | { |
5875 | } | |
5876 | #endif | |
5877 | ||
1f11eb6a GH |
5878 | static void set_rq_online(struct rq *rq) |
5879 | { | |
5880 | if (!rq->online) { | |
5881 | const struct sched_class *class; | |
5882 | ||
c6c4927b | 5883 | cpumask_set_cpu(rq->cpu, rq->rd->online); |
1f11eb6a GH |
5884 | rq->online = 1; |
5885 | ||
5886 | for_each_class(class) { | |
5887 | if (class->rq_online) | |
5888 | class->rq_online(rq); | |
5889 | } | |
5890 | } | |
5891 | } | |
5892 | ||
5893 | static void set_rq_offline(struct rq *rq) | |
5894 | { | |
5895 | if (rq->online) { | |
5896 | const struct sched_class *class; | |
5897 | ||
5898 | for_each_class(class) { | |
5899 | if (class->rq_offline) | |
5900 | class->rq_offline(rq); | |
5901 | } | |
5902 | ||
c6c4927b | 5903 | cpumask_clear_cpu(rq->cpu, rq->rd->online); |
1f11eb6a GH |
5904 | rq->online = 0; |
5905 | } | |
5906 | } | |
5907 | ||
1da177e4 LT |
5908 | /* |
5909 | * migration_call - callback that gets triggered when a CPU is added. | |
5910 | * Here we can start up the necessary migration thread for the new CPU. | |
5911 | */ | |
48f24c4d IM |
5912 | static int __cpuinit |
5913 | migration_call(struct notifier_block *nfb, unsigned long action, void *hcpu) | |
1da177e4 | 5914 | { |
48f24c4d | 5915 | int cpu = (long)hcpu; |
1da177e4 | 5916 | unsigned long flags; |
969c7921 | 5917 | struct rq *rq = cpu_rq(cpu); |
1da177e4 LT |
5918 | |
5919 | switch (action) { | |
5be9361c | 5920 | |
1da177e4 | 5921 | case CPU_UP_PREPARE: |
8bb78442 | 5922 | case CPU_UP_PREPARE_FROZEN: |
a468d389 | 5923 | rq->calc_load_update = calc_load_update; |
1da177e4 | 5924 | break; |
48f24c4d | 5925 | |
1da177e4 | 5926 | case CPU_ONLINE: |
8bb78442 | 5927 | case CPU_ONLINE_FROZEN: |
1f94ef59 | 5928 | /* Update our root-domain */ |
05fa785c | 5929 | raw_spin_lock_irqsave(&rq->lock, flags); |
1f94ef59 | 5930 | if (rq->rd) { |
c6c4927b | 5931 | BUG_ON(!cpumask_test_cpu(cpu, rq->rd->span)); |
1f11eb6a GH |
5932 | |
5933 | set_rq_online(rq); | |
1f94ef59 | 5934 | } |
05fa785c | 5935 | raw_spin_unlock_irqrestore(&rq->lock, flags); |
1da177e4 | 5936 | break; |
48f24c4d | 5937 | |
1da177e4 | 5938 | #ifdef CONFIG_HOTPLUG_CPU |
1da177e4 | 5939 | case CPU_DEAD: |
8bb78442 | 5940 | case CPU_DEAD_FROZEN: |
1da177e4 | 5941 | migrate_live_tasks(cpu); |
1da177e4 | 5942 | /* Idle task back to normal (off runqueue, low prio) */ |
05fa785c | 5943 | raw_spin_lock_irq(&rq->lock); |
2e1cb74a | 5944 | deactivate_task(rq, rq->idle, 0); |
dd41f596 IM |
5945 | __setscheduler(rq, rq->idle, SCHED_NORMAL, 0); |
5946 | rq->idle->sched_class = &idle_sched_class; | |
1da177e4 | 5947 | migrate_dead_tasks(cpu); |
05fa785c | 5948 | raw_spin_unlock_irq(&rq->lock); |
1da177e4 LT |
5949 | migrate_nr_uninterruptible(rq); |
5950 | BUG_ON(rq->nr_running != 0); | |
dce48a84 | 5951 | calc_global_load_remove(rq); |
1da177e4 | 5952 | break; |
57d885fe | 5953 | |
08f503b0 GH |
5954 | case CPU_DYING: |
5955 | case CPU_DYING_FROZEN: | |
57d885fe | 5956 | /* Update our root-domain */ |
05fa785c | 5957 | raw_spin_lock_irqsave(&rq->lock, flags); |
57d885fe | 5958 | if (rq->rd) { |
c6c4927b | 5959 | BUG_ON(!cpumask_test_cpu(cpu, rq->rd->span)); |
1f11eb6a | 5960 | set_rq_offline(rq); |
57d885fe | 5961 | } |
05fa785c | 5962 | raw_spin_unlock_irqrestore(&rq->lock, flags); |
57d885fe | 5963 | break; |
1da177e4 LT |
5964 | #endif |
5965 | } | |
5966 | return NOTIFY_OK; | |
5967 | } | |
5968 | ||
f38b0820 PM |
5969 | /* |
5970 | * Register at high priority so that task migration (migrate_all_tasks) | |
5971 | * happens before everything else. This has to be lower priority than | |
cdd6c482 | 5972 | * the notifier in the perf_event subsystem, though. |
1da177e4 | 5973 | */ |
26c2143b | 5974 | static struct notifier_block __cpuinitdata migration_notifier = { |
1da177e4 | 5975 | .notifier_call = migration_call, |
50a323b7 | 5976 | .priority = CPU_PRI_MIGRATION, |
1da177e4 LT |
5977 | }; |
5978 | ||
3a101d05 TH |
5979 | static int __cpuinit sched_cpu_active(struct notifier_block *nfb, |
5980 | unsigned long action, void *hcpu) | |
5981 | { | |
5982 | switch (action & ~CPU_TASKS_FROZEN) { | |
5983 | case CPU_ONLINE: | |
5984 | case CPU_DOWN_FAILED: | |
5985 | set_cpu_active((long)hcpu, true); | |
5986 | return NOTIFY_OK; | |
5987 | default: | |
5988 | return NOTIFY_DONE; | |
5989 | } | |
5990 | } | |
5991 | ||
5992 | static int __cpuinit sched_cpu_inactive(struct notifier_block *nfb, | |
5993 | unsigned long action, void *hcpu) | |
5994 | { | |
5995 | switch (action & ~CPU_TASKS_FROZEN) { | |
5996 | case CPU_DOWN_PREPARE: | |
5997 | set_cpu_active((long)hcpu, false); | |
5998 | return NOTIFY_OK; | |
5999 | default: | |
6000 | return NOTIFY_DONE; | |
6001 | } | |
6002 | } | |
6003 | ||
7babe8db | 6004 | static int __init migration_init(void) |
1da177e4 LT |
6005 | { |
6006 | void *cpu = (void *)(long)smp_processor_id(); | |
07dccf33 | 6007 | int err; |
48f24c4d | 6008 | |
3a101d05 | 6009 | /* Initialize migration for the boot CPU */ |
07dccf33 AM |
6010 | err = migration_call(&migration_notifier, CPU_UP_PREPARE, cpu); |
6011 | BUG_ON(err == NOTIFY_BAD); | |
1da177e4 LT |
6012 | migration_call(&migration_notifier, CPU_ONLINE, cpu); |
6013 | register_cpu_notifier(&migration_notifier); | |
7babe8db | 6014 | |
3a101d05 TH |
6015 | /* Register cpu active notifiers */ |
6016 | cpu_notifier(sched_cpu_active, CPU_PRI_SCHED_ACTIVE); | |
6017 | cpu_notifier(sched_cpu_inactive, CPU_PRI_SCHED_INACTIVE); | |
6018 | ||
a004cd42 | 6019 | return 0; |
1da177e4 | 6020 | } |
7babe8db | 6021 | early_initcall(migration_init); |
1da177e4 LT |
6022 | #endif |
6023 | ||
6024 | #ifdef CONFIG_SMP | |
476f3534 | 6025 | |
3e9830dc | 6026 | #ifdef CONFIG_SCHED_DEBUG |
4dcf6aff | 6027 | |
f6630114 MT |
6028 | static __read_mostly int sched_domain_debug_enabled; |
6029 | ||
6030 | static int __init sched_domain_debug_setup(char *str) | |
6031 | { | |
6032 | sched_domain_debug_enabled = 1; | |
6033 | ||
6034 | return 0; | |
6035 | } | |
6036 | early_param("sched_debug", sched_domain_debug_setup); | |
6037 | ||
7c16ec58 | 6038 | static int sched_domain_debug_one(struct sched_domain *sd, int cpu, int level, |
96f874e2 | 6039 | struct cpumask *groupmask) |
1da177e4 | 6040 | { |
4dcf6aff | 6041 | struct sched_group *group = sd->groups; |
434d53b0 | 6042 | char str[256]; |
1da177e4 | 6043 | |
968ea6d8 | 6044 | cpulist_scnprintf(str, sizeof(str), sched_domain_span(sd)); |
96f874e2 | 6045 | cpumask_clear(groupmask); |
4dcf6aff IM |
6046 | |
6047 | printk(KERN_DEBUG "%*s domain %d: ", level, "", level); | |
6048 | ||
6049 | if (!(sd->flags & SD_LOAD_BALANCE)) { | |
3df0fc5b | 6050 | printk("does not load-balance\n"); |
4dcf6aff | 6051 | if (sd->parent) |
3df0fc5b PZ |
6052 | printk(KERN_ERR "ERROR: !SD_LOAD_BALANCE domain" |
6053 | " has parent"); | |
4dcf6aff | 6054 | return -1; |
41c7ce9a NP |
6055 | } |
6056 | ||
3df0fc5b | 6057 | printk(KERN_CONT "span %s level %s\n", str, sd->name); |
4dcf6aff | 6058 | |
758b2cdc | 6059 | if (!cpumask_test_cpu(cpu, sched_domain_span(sd))) { |
3df0fc5b PZ |
6060 | printk(KERN_ERR "ERROR: domain->span does not contain " |
6061 | "CPU%d\n", cpu); | |
4dcf6aff | 6062 | } |
758b2cdc | 6063 | if (!cpumask_test_cpu(cpu, sched_group_cpus(group))) { |
3df0fc5b PZ |
6064 | printk(KERN_ERR "ERROR: domain->groups does not contain" |
6065 | " CPU%d\n", cpu); | |
4dcf6aff | 6066 | } |
1da177e4 | 6067 | |
4dcf6aff | 6068 | printk(KERN_DEBUG "%*s groups:", level + 1, ""); |
1da177e4 | 6069 | do { |
4dcf6aff | 6070 | if (!group) { |
3df0fc5b PZ |
6071 | printk("\n"); |
6072 | printk(KERN_ERR "ERROR: group is NULL\n"); | |
1da177e4 LT |
6073 | break; |
6074 | } | |
6075 | ||
18a3885f | 6076 | if (!group->cpu_power) { |
3df0fc5b PZ |
6077 | printk(KERN_CONT "\n"); |
6078 | printk(KERN_ERR "ERROR: domain->cpu_power not " | |
6079 | "set\n"); | |
4dcf6aff IM |
6080 | break; |
6081 | } | |
1da177e4 | 6082 | |
758b2cdc | 6083 | if (!cpumask_weight(sched_group_cpus(group))) { |
3df0fc5b PZ |
6084 | printk(KERN_CONT "\n"); |
6085 | printk(KERN_ERR "ERROR: empty group\n"); | |
4dcf6aff IM |
6086 | break; |
6087 | } | |
1da177e4 | 6088 | |
758b2cdc | 6089 | if (cpumask_intersects(groupmask, sched_group_cpus(group))) { |
3df0fc5b PZ |
6090 | printk(KERN_CONT "\n"); |
6091 | printk(KERN_ERR "ERROR: repeated CPUs\n"); | |
4dcf6aff IM |
6092 | break; |
6093 | } | |
1da177e4 | 6094 | |
758b2cdc | 6095 | cpumask_or(groupmask, groupmask, sched_group_cpus(group)); |
1da177e4 | 6096 | |
968ea6d8 | 6097 | cpulist_scnprintf(str, sizeof(str), sched_group_cpus(group)); |
381512cf | 6098 | |
3df0fc5b | 6099 | printk(KERN_CONT " %s", str); |
18a3885f | 6100 | if (group->cpu_power != SCHED_LOAD_SCALE) { |
3df0fc5b PZ |
6101 | printk(KERN_CONT " (cpu_power = %d)", |
6102 | group->cpu_power); | |
381512cf | 6103 | } |
1da177e4 | 6104 | |
4dcf6aff IM |
6105 | group = group->next; |
6106 | } while (group != sd->groups); | |
3df0fc5b | 6107 | printk(KERN_CONT "\n"); |
1da177e4 | 6108 | |
758b2cdc | 6109 | if (!cpumask_equal(sched_domain_span(sd), groupmask)) |
3df0fc5b | 6110 | printk(KERN_ERR "ERROR: groups don't span domain->span\n"); |
1da177e4 | 6111 | |
758b2cdc RR |
6112 | if (sd->parent && |
6113 | !cpumask_subset(groupmask, sched_domain_span(sd->parent))) | |
3df0fc5b PZ |
6114 | printk(KERN_ERR "ERROR: parent span is not a superset " |
6115 | "of domain->span\n"); | |
4dcf6aff IM |
6116 | return 0; |
6117 | } | |
1da177e4 | 6118 | |
4dcf6aff IM |
6119 | static void sched_domain_debug(struct sched_domain *sd, int cpu) |
6120 | { | |
d5dd3db1 | 6121 | cpumask_var_t groupmask; |
4dcf6aff | 6122 | int level = 0; |
1da177e4 | 6123 | |
f6630114 MT |
6124 | if (!sched_domain_debug_enabled) |
6125 | return; | |
6126 | ||
4dcf6aff IM |
6127 | if (!sd) { |
6128 | printk(KERN_DEBUG "CPU%d attaching NULL sched-domain.\n", cpu); | |
6129 | return; | |
6130 | } | |
1da177e4 | 6131 | |
4dcf6aff IM |
6132 | printk(KERN_DEBUG "CPU%d attaching sched-domain:\n", cpu); |
6133 | ||
d5dd3db1 | 6134 | if (!alloc_cpumask_var(&groupmask, GFP_KERNEL)) { |
7c16ec58 MT |
6135 | printk(KERN_DEBUG "Cannot load-balance (out of memory)\n"); |
6136 | return; | |
6137 | } | |
6138 | ||
4dcf6aff | 6139 | for (;;) { |
7c16ec58 | 6140 | if (sched_domain_debug_one(sd, cpu, level, groupmask)) |
4dcf6aff | 6141 | break; |
1da177e4 LT |
6142 | level++; |
6143 | sd = sd->parent; | |
33859f7f | 6144 | if (!sd) |
4dcf6aff IM |
6145 | break; |
6146 | } | |
d5dd3db1 | 6147 | free_cpumask_var(groupmask); |
1da177e4 | 6148 | } |
6d6bc0ad | 6149 | #else /* !CONFIG_SCHED_DEBUG */ |
48f24c4d | 6150 | # define sched_domain_debug(sd, cpu) do { } while (0) |
6d6bc0ad | 6151 | #endif /* CONFIG_SCHED_DEBUG */ |
1da177e4 | 6152 | |
1a20ff27 | 6153 | static int sd_degenerate(struct sched_domain *sd) |
245af2c7 | 6154 | { |
758b2cdc | 6155 | if (cpumask_weight(sched_domain_span(sd)) == 1) |
245af2c7 SS |
6156 | return 1; |
6157 | ||
6158 | /* Following flags need at least 2 groups */ | |
6159 | if (sd->flags & (SD_LOAD_BALANCE | | |
6160 | SD_BALANCE_NEWIDLE | | |
6161 | SD_BALANCE_FORK | | |
89c4710e SS |
6162 | SD_BALANCE_EXEC | |
6163 | SD_SHARE_CPUPOWER | | |
6164 | SD_SHARE_PKG_RESOURCES)) { | |
245af2c7 SS |
6165 | if (sd->groups != sd->groups->next) |
6166 | return 0; | |
6167 | } | |
6168 | ||
6169 | /* Following flags don't use groups */ | |
c88d5910 | 6170 | if (sd->flags & (SD_WAKE_AFFINE)) |
245af2c7 SS |
6171 | return 0; |
6172 | ||
6173 | return 1; | |
6174 | } | |
6175 | ||
48f24c4d IM |
6176 | static int |
6177 | sd_parent_degenerate(struct sched_domain *sd, struct sched_domain *parent) | |
245af2c7 SS |
6178 | { |
6179 | unsigned long cflags = sd->flags, pflags = parent->flags; | |
6180 | ||
6181 | if (sd_degenerate(parent)) | |
6182 | return 1; | |
6183 | ||
758b2cdc | 6184 | if (!cpumask_equal(sched_domain_span(sd), sched_domain_span(parent))) |
245af2c7 SS |
6185 | return 0; |
6186 | ||
245af2c7 SS |
6187 | /* Flags needing groups don't count if only 1 group in parent */ |
6188 | if (parent->groups == parent->groups->next) { | |
6189 | pflags &= ~(SD_LOAD_BALANCE | | |
6190 | SD_BALANCE_NEWIDLE | | |
6191 | SD_BALANCE_FORK | | |
89c4710e SS |
6192 | SD_BALANCE_EXEC | |
6193 | SD_SHARE_CPUPOWER | | |
6194 | SD_SHARE_PKG_RESOURCES); | |
5436499e KC |
6195 | if (nr_node_ids == 1) |
6196 | pflags &= ~SD_SERIALIZE; | |
245af2c7 SS |
6197 | } |
6198 | if (~cflags & pflags) | |
6199 | return 0; | |
6200 | ||
6201 | return 1; | |
6202 | } | |
6203 | ||
c6c4927b RR |
6204 | static void free_rootdomain(struct root_domain *rd) |
6205 | { | |
047106ad PZ |
6206 | synchronize_sched(); |
6207 | ||
68e74568 RR |
6208 | cpupri_cleanup(&rd->cpupri); |
6209 | ||
c6c4927b RR |
6210 | free_cpumask_var(rd->rto_mask); |
6211 | free_cpumask_var(rd->online); | |
6212 | free_cpumask_var(rd->span); | |
6213 | kfree(rd); | |
6214 | } | |
6215 | ||
57d885fe GH |
6216 | static void rq_attach_root(struct rq *rq, struct root_domain *rd) |
6217 | { | |
a0490fa3 | 6218 | struct root_domain *old_rd = NULL; |
57d885fe | 6219 | unsigned long flags; |
57d885fe | 6220 | |
05fa785c | 6221 | raw_spin_lock_irqsave(&rq->lock, flags); |
57d885fe GH |
6222 | |
6223 | if (rq->rd) { | |
a0490fa3 | 6224 | old_rd = rq->rd; |
57d885fe | 6225 | |
c6c4927b | 6226 | if (cpumask_test_cpu(rq->cpu, old_rd->online)) |
1f11eb6a | 6227 | set_rq_offline(rq); |
57d885fe | 6228 | |
c6c4927b | 6229 | cpumask_clear_cpu(rq->cpu, old_rd->span); |
dc938520 | 6230 | |
a0490fa3 IM |
6231 | /* |
6232 | * If we dont want to free the old_rt yet then | |
6233 | * set old_rd to NULL to skip the freeing later | |
6234 | * in this function: | |
6235 | */ | |
6236 | if (!atomic_dec_and_test(&old_rd->refcount)) | |
6237 | old_rd = NULL; | |
57d885fe GH |
6238 | } |
6239 | ||
6240 | atomic_inc(&rd->refcount); | |
6241 | rq->rd = rd; | |
6242 | ||
c6c4927b | 6243 | cpumask_set_cpu(rq->cpu, rd->span); |
00aec93d | 6244 | if (cpumask_test_cpu(rq->cpu, cpu_active_mask)) |
1f11eb6a | 6245 | set_rq_online(rq); |
57d885fe | 6246 | |
05fa785c | 6247 | raw_spin_unlock_irqrestore(&rq->lock, flags); |
a0490fa3 IM |
6248 | |
6249 | if (old_rd) | |
6250 | free_rootdomain(old_rd); | |
57d885fe GH |
6251 | } |
6252 | ||
68c38fc3 | 6253 | static int init_rootdomain(struct root_domain *rd) |
57d885fe GH |
6254 | { |
6255 | memset(rd, 0, sizeof(*rd)); | |
6256 | ||
68c38fc3 | 6257 | if (!alloc_cpumask_var(&rd->span, GFP_KERNEL)) |
0c910d28 | 6258 | goto out; |
68c38fc3 | 6259 | if (!alloc_cpumask_var(&rd->online, GFP_KERNEL)) |
c6c4927b | 6260 | goto free_span; |
68c38fc3 | 6261 | if (!alloc_cpumask_var(&rd->rto_mask, GFP_KERNEL)) |
c6c4927b | 6262 | goto free_online; |
6e0534f2 | 6263 | |
68c38fc3 | 6264 | if (cpupri_init(&rd->cpupri) != 0) |
68e74568 | 6265 | goto free_rto_mask; |
c6c4927b | 6266 | return 0; |
6e0534f2 | 6267 | |
68e74568 RR |
6268 | free_rto_mask: |
6269 | free_cpumask_var(rd->rto_mask); | |
c6c4927b RR |
6270 | free_online: |
6271 | free_cpumask_var(rd->online); | |
6272 | free_span: | |
6273 | free_cpumask_var(rd->span); | |
0c910d28 | 6274 | out: |
c6c4927b | 6275 | return -ENOMEM; |
57d885fe GH |
6276 | } |
6277 | ||
6278 | static void init_defrootdomain(void) | |
6279 | { | |
68c38fc3 | 6280 | init_rootdomain(&def_root_domain); |
c6c4927b | 6281 | |
57d885fe GH |
6282 | atomic_set(&def_root_domain.refcount, 1); |
6283 | } | |
6284 | ||
dc938520 | 6285 | static struct root_domain *alloc_rootdomain(void) |
57d885fe GH |
6286 | { |
6287 | struct root_domain *rd; | |
6288 | ||
6289 | rd = kmalloc(sizeof(*rd), GFP_KERNEL); | |
6290 | if (!rd) | |
6291 | return NULL; | |
6292 | ||
68c38fc3 | 6293 | if (init_rootdomain(rd) != 0) { |
c6c4927b RR |
6294 | kfree(rd); |
6295 | return NULL; | |
6296 | } | |
57d885fe GH |
6297 | |
6298 | return rd; | |
6299 | } | |
6300 | ||
1da177e4 | 6301 | /* |
0eab9146 | 6302 | * Attach the domain 'sd' to 'cpu' as its base domain. Callers must |
1da177e4 LT |
6303 | * hold the hotplug lock. |
6304 | */ | |
0eab9146 IM |
6305 | static void |
6306 | cpu_attach_domain(struct sched_domain *sd, struct root_domain *rd, int cpu) | |
1da177e4 | 6307 | { |
70b97a7f | 6308 | struct rq *rq = cpu_rq(cpu); |
245af2c7 SS |
6309 | struct sched_domain *tmp; |
6310 | ||
669c55e9 PZ |
6311 | for (tmp = sd; tmp; tmp = tmp->parent) |
6312 | tmp->span_weight = cpumask_weight(sched_domain_span(tmp)); | |
6313 | ||
245af2c7 | 6314 | /* Remove the sched domains which do not contribute to scheduling. */ |
f29c9b1c | 6315 | for (tmp = sd; tmp; ) { |
245af2c7 SS |
6316 | struct sched_domain *parent = tmp->parent; |
6317 | if (!parent) | |
6318 | break; | |
f29c9b1c | 6319 | |
1a848870 | 6320 | if (sd_parent_degenerate(tmp, parent)) { |
245af2c7 | 6321 | tmp->parent = parent->parent; |
1a848870 SS |
6322 | if (parent->parent) |
6323 | parent->parent->child = tmp; | |
f29c9b1c LZ |
6324 | } else |
6325 | tmp = tmp->parent; | |
245af2c7 SS |
6326 | } |
6327 | ||
1a848870 | 6328 | if (sd && sd_degenerate(sd)) { |
245af2c7 | 6329 | sd = sd->parent; |
1a848870 SS |
6330 | if (sd) |
6331 | sd->child = NULL; | |
6332 | } | |
1da177e4 LT |
6333 | |
6334 | sched_domain_debug(sd, cpu); | |
6335 | ||
57d885fe | 6336 | rq_attach_root(rq, rd); |
674311d5 | 6337 | rcu_assign_pointer(rq->sd, sd); |
1da177e4 LT |
6338 | } |
6339 | ||
6340 | /* cpus with isolated domains */ | |
dcc30a35 | 6341 | static cpumask_var_t cpu_isolated_map; |
1da177e4 LT |
6342 | |
6343 | /* Setup the mask of cpus configured for isolated domains */ | |
6344 | static int __init isolated_cpu_setup(char *str) | |
6345 | { | |
bdddd296 | 6346 | alloc_bootmem_cpumask_var(&cpu_isolated_map); |
968ea6d8 | 6347 | cpulist_parse(str, cpu_isolated_map); |
1da177e4 LT |
6348 | return 1; |
6349 | } | |
6350 | ||
8927f494 | 6351 | __setup("isolcpus=", isolated_cpu_setup); |
1da177e4 LT |
6352 | |
6353 | /* | |
6711cab4 SS |
6354 | * init_sched_build_groups takes the cpumask we wish to span, and a pointer |
6355 | * to a function which identifies what group(along with sched group) a CPU | |
96f874e2 RR |
6356 | * belongs to. The return value of group_fn must be a >= 0 and < nr_cpu_ids |
6357 | * (due to the fact that we keep track of groups covered with a struct cpumask). | |
1da177e4 LT |
6358 | * |
6359 | * init_sched_build_groups will build a circular linked list of the groups | |
6360 | * covered by the given span, and will set each group's ->cpumask correctly, | |
6361 | * and ->cpu_power to 0. | |
6362 | */ | |
a616058b | 6363 | static void |
96f874e2 RR |
6364 | init_sched_build_groups(const struct cpumask *span, |
6365 | const struct cpumask *cpu_map, | |
6366 | int (*group_fn)(int cpu, const struct cpumask *cpu_map, | |
7c16ec58 | 6367 | struct sched_group **sg, |
96f874e2 RR |
6368 | struct cpumask *tmpmask), |
6369 | struct cpumask *covered, struct cpumask *tmpmask) | |
1da177e4 LT |
6370 | { |
6371 | struct sched_group *first = NULL, *last = NULL; | |
1da177e4 LT |
6372 | int i; |
6373 | ||
96f874e2 | 6374 | cpumask_clear(covered); |
7c16ec58 | 6375 | |
abcd083a | 6376 | for_each_cpu(i, span) { |
6711cab4 | 6377 | struct sched_group *sg; |
7c16ec58 | 6378 | int group = group_fn(i, cpu_map, &sg, tmpmask); |
1da177e4 LT |
6379 | int j; |
6380 | ||
758b2cdc | 6381 | if (cpumask_test_cpu(i, covered)) |
1da177e4 LT |
6382 | continue; |
6383 | ||
758b2cdc | 6384 | cpumask_clear(sched_group_cpus(sg)); |
18a3885f | 6385 | sg->cpu_power = 0; |
1da177e4 | 6386 | |
abcd083a | 6387 | for_each_cpu(j, span) { |
7c16ec58 | 6388 | if (group_fn(j, cpu_map, NULL, tmpmask) != group) |
1da177e4 LT |
6389 | continue; |
6390 | ||
96f874e2 | 6391 | cpumask_set_cpu(j, covered); |
758b2cdc | 6392 | cpumask_set_cpu(j, sched_group_cpus(sg)); |
1da177e4 LT |
6393 | } |
6394 | if (!first) | |
6395 | first = sg; | |
6396 | if (last) | |
6397 | last->next = sg; | |
6398 | last = sg; | |
6399 | } | |
6400 | last->next = first; | |
6401 | } | |
6402 | ||
9c1cfda2 | 6403 | #define SD_NODES_PER_DOMAIN 16 |
1da177e4 | 6404 | |
9c1cfda2 | 6405 | #ifdef CONFIG_NUMA |
198e2f18 | 6406 | |
9c1cfda2 JH |
6407 | /** |
6408 | * find_next_best_node - find the next node to include in a sched_domain | |
6409 | * @node: node whose sched_domain we're building | |
6410 | * @used_nodes: nodes already in the sched_domain | |
6411 | * | |
41a2d6cf | 6412 | * Find the next node to include in a given scheduling domain. Simply |
9c1cfda2 JH |
6413 | * finds the closest node not already in the @used_nodes map. |
6414 | * | |
6415 | * Should use nodemask_t. | |
6416 | */ | |
c5f59f08 | 6417 | static int find_next_best_node(int node, nodemask_t *used_nodes) |
9c1cfda2 JH |
6418 | { |
6419 | int i, n, val, min_val, best_node = 0; | |
6420 | ||
6421 | min_val = INT_MAX; | |
6422 | ||
076ac2af | 6423 | for (i = 0; i < nr_node_ids; i++) { |
9c1cfda2 | 6424 | /* Start at @node */ |
076ac2af | 6425 | n = (node + i) % nr_node_ids; |
9c1cfda2 JH |
6426 | |
6427 | if (!nr_cpus_node(n)) | |
6428 | continue; | |
6429 | ||
6430 | /* Skip already used nodes */ | |
c5f59f08 | 6431 | if (node_isset(n, *used_nodes)) |
9c1cfda2 JH |
6432 | continue; |
6433 | ||
6434 | /* Simple min distance search */ | |
6435 | val = node_distance(node, n); | |
6436 | ||
6437 | if (val < min_val) { | |
6438 | min_val = val; | |
6439 | best_node = n; | |
6440 | } | |
6441 | } | |
6442 | ||
c5f59f08 | 6443 | node_set(best_node, *used_nodes); |
9c1cfda2 JH |
6444 | return best_node; |
6445 | } | |
6446 | ||
6447 | /** | |
6448 | * sched_domain_node_span - get a cpumask for a node's sched_domain | |
6449 | * @node: node whose cpumask we're constructing | |
73486722 | 6450 | * @span: resulting cpumask |
9c1cfda2 | 6451 | * |
41a2d6cf | 6452 | * Given a node, construct a good cpumask for its sched_domain to span. It |
9c1cfda2 JH |
6453 | * should be one that prevents unnecessary balancing, but also spreads tasks |
6454 | * out optimally. | |
6455 | */ | |
96f874e2 | 6456 | static void sched_domain_node_span(int node, struct cpumask *span) |
9c1cfda2 | 6457 | { |
c5f59f08 | 6458 | nodemask_t used_nodes; |
48f24c4d | 6459 | int i; |
9c1cfda2 | 6460 | |
6ca09dfc | 6461 | cpumask_clear(span); |
c5f59f08 | 6462 | nodes_clear(used_nodes); |
9c1cfda2 | 6463 | |
6ca09dfc | 6464 | cpumask_or(span, span, cpumask_of_node(node)); |
c5f59f08 | 6465 | node_set(node, used_nodes); |
9c1cfda2 JH |
6466 | |
6467 | for (i = 1; i < SD_NODES_PER_DOMAIN; i++) { | |
c5f59f08 | 6468 | int next_node = find_next_best_node(node, &used_nodes); |
48f24c4d | 6469 | |
6ca09dfc | 6470 | cpumask_or(span, span, cpumask_of_node(next_node)); |
9c1cfda2 | 6471 | } |
9c1cfda2 | 6472 | } |
6d6bc0ad | 6473 | #endif /* CONFIG_NUMA */ |
9c1cfda2 | 6474 | |
5c45bf27 | 6475 | int sched_smt_power_savings = 0, sched_mc_power_savings = 0; |
48f24c4d | 6476 | |
6c99e9ad RR |
6477 | /* |
6478 | * The cpus mask in sched_group and sched_domain hangs off the end. | |
4200efd9 IM |
6479 | * |
6480 | * ( See the the comments in include/linux/sched.h:struct sched_group | |
6481 | * and struct sched_domain. ) | |
6c99e9ad RR |
6482 | */ |
6483 | struct static_sched_group { | |
6484 | struct sched_group sg; | |
6485 | DECLARE_BITMAP(cpus, CONFIG_NR_CPUS); | |
6486 | }; | |
6487 | ||
6488 | struct static_sched_domain { | |
6489 | struct sched_domain sd; | |
6490 | DECLARE_BITMAP(span, CONFIG_NR_CPUS); | |
6491 | }; | |
6492 | ||
49a02c51 AH |
6493 | struct s_data { |
6494 | #ifdef CONFIG_NUMA | |
6495 | int sd_allnodes; | |
6496 | cpumask_var_t domainspan; | |
6497 | cpumask_var_t covered; | |
6498 | cpumask_var_t notcovered; | |
6499 | #endif | |
6500 | cpumask_var_t nodemask; | |
6501 | cpumask_var_t this_sibling_map; | |
6502 | cpumask_var_t this_core_map; | |
6503 | cpumask_var_t send_covered; | |
6504 | cpumask_var_t tmpmask; | |
6505 | struct sched_group **sched_group_nodes; | |
6506 | struct root_domain *rd; | |
6507 | }; | |
6508 | ||
2109b99e AH |
6509 | enum s_alloc { |
6510 | sa_sched_groups = 0, | |
6511 | sa_rootdomain, | |
6512 | sa_tmpmask, | |
6513 | sa_send_covered, | |
6514 | sa_this_core_map, | |
6515 | sa_this_sibling_map, | |
6516 | sa_nodemask, | |
6517 | sa_sched_group_nodes, | |
6518 | #ifdef CONFIG_NUMA | |
6519 | sa_notcovered, | |
6520 | sa_covered, | |
6521 | sa_domainspan, | |
6522 | #endif | |
6523 | sa_none, | |
6524 | }; | |
6525 | ||
9c1cfda2 | 6526 | /* |
48f24c4d | 6527 | * SMT sched-domains: |
9c1cfda2 | 6528 | */ |
1da177e4 | 6529 | #ifdef CONFIG_SCHED_SMT |
6c99e9ad | 6530 | static DEFINE_PER_CPU(struct static_sched_domain, cpu_domains); |
1871e52c | 6531 | static DEFINE_PER_CPU(struct static_sched_group, sched_groups); |
48f24c4d | 6532 | |
41a2d6cf | 6533 | static int |
96f874e2 RR |
6534 | cpu_to_cpu_group(int cpu, const struct cpumask *cpu_map, |
6535 | struct sched_group **sg, struct cpumask *unused) | |
1da177e4 | 6536 | { |
6711cab4 | 6537 | if (sg) |
1871e52c | 6538 | *sg = &per_cpu(sched_groups, cpu).sg; |
1da177e4 LT |
6539 | return cpu; |
6540 | } | |
6d6bc0ad | 6541 | #endif /* CONFIG_SCHED_SMT */ |
1da177e4 | 6542 | |
48f24c4d IM |
6543 | /* |
6544 | * multi-core sched-domains: | |
6545 | */ | |
1e9f28fa | 6546 | #ifdef CONFIG_SCHED_MC |
6c99e9ad RR |
6547 | static DEFINE_PER_CPU(struct static_sched_domain, core_domains); |
6548 | static DEFINE_PER_CPU(struct static_sched_group, sched_group_core); | |
6d6bc0ad | 6549 | #endif /* CONFIG_SCHED_MC */ |
1e9f28fa SS |
6550 | |
6551 | #if defined(CONFIG_SCHED_MC) && defined(CONFIG_SCHED_SMT) | |
41a2d6cf | 6552 | static int |
96f874e2 RR |
6553 | cpu_to_core_group(int cpu, const struct cpumask *cpu_map, |
6554 | struct sched_group **sg, struct cpumask *mask) | |
1e9f28fa | 6555 | { |
6711cab4 | 6556 | int group; |
7c16ec58 | 6557 | |
c69fc56d | 6558 | cpumask_and(mask, topology_thread_cpumask(cpu), cpu_map); |
96f874e2 | 6559 | group = cpumask_first(mask); |
6711cab4 | 6560 | if (sg) |
6c99e9ad | 6561 | *sg = &per_cpu(sched_group_core, group).sg; |
6711cab4 | 6562 | return group; |
1e9f28fa SS |
6563 | } |
6564 | #elif defined(CONFIG_SCHED_MC) | |
41a2d6cf | 6565 | static int |
96f874e2 RR |
6566 | cpu_to_core_group(int cpu, const struct cpumask *cpu_map, |
6567 | struct sched_group **sg, struct cpumask *unused) | |
1e9f28fa | 6568 | { |
6711cab4 | 6569 | if (sg) |
6c99e9ad | 6570 | *sg = &per_cpu(sched_group_core, cpu).sg; |
1e9f28fa SS |
6571 | return cpu; |
6572 | } | |
6573 | #endif | |
6574 | ||
6c99e9ad RR |
6575 | static DEFINE_PER_CPU(struct static_sched_domain, phys_domains); |
6576 | static DEFINE_PER_CPU(struct static_sched_group, sched_group_phys); | |
48f24c4d | 6577 | |
41a2d6cf | 6578 | static int |
96f874e2 RR |
6579 | cpu_to_phys_group(int cpu, const struct cpumask *cpu_map, |
6580 | struct sched_group **sg, struct cpumask *mask) | |
1da177e4 | 6581 | { |
6711cab4 | 6582 | int group; |
48f24c4d | 6583 | #ifdef CONFIG_SCHED_MC |
6ca09dfc | 6584 | cpumask_and(mask, cpu_coregroup_mask(cpu), cpu_map); |
96f874e2 | 6585 | group = cpumask_first(mask); |
1e9f28fa | 6586 | #elif defined(CONFIG_SCHED_SMT) |
c69fc56d | 6587 | cpumask_and(mask, topology_thread_cpumask(cpu), cpu_map); |
96f874e2 | 6588 | group = cpumask_first(mask); |
1da177e4 | 6589 | #else |
6711cab4 | 6590 | group = cpu; |
1da177e4 | 6591 | #endif |
6711cab4 | 6592 | if (sg) |
6c99e9ad | 6593 | *sg = &per_cpu(sched_group_phys, group).sg; |
6711cab4 | 6594 | return group; |
1da177e4 LT |
6595 | } |
6596 | ||
6597 | #ifdef CONFIG_NUMA | |
1da177e4 | 6598 | /* |
9c1cfda2 JH |
6599 | * The init_sched_build_groups can't handle what we want to do with node |
6600 | * groups, so roll our own. Now each node has its own list of groups which | |
6601 | * gets dynamically allocated. | |
1da177e4 | 6602 | */ |
62ea9ceb | 6603 | static DEFINE_PER_CPU(struct static_sched_domain, node_domains); |
434d53b0 | 6604 | static struct sched_group ***sched_group_nodes_bycpu; |
1da177e4 | 6605 | |
62ea9ceb | 6606 | static DEFINE_PER_CPU(struct static_sched_domain, allnodes_domains); |
6c99e9ad | 6607 | static DEFINE_PER_CPU(struct static_sched_group, sched_group_allnodes); |
9c1cfda2 | 6608 | |
96f874e2 RR |
6609 | static int cpu_to_allnodes_group(int cpu, const struct cpumask *cpu_map, |
6610 | struct sched_group **sg, | |
6611 | struct cpumask *nodemask) | |
9c1cfda2 | 6612 | { |
6711cab4 SS |
6613 | int group; |
6614 | ||
6ca09dfc | 6615 | cpumask_and(nodemask, cpumask_of_node(cpu_to_node(cpu)), cpu_map); |
96f874e2 | 6616 | group = cpumask_first(nodemask); |
6711cab4 SS |
6617 | |
6618 | if (sg) | |
6c99e9ad | 6619 | *sg = &per_cpu(sched_group_allnodes, group).sg; |
6711cab4 | 6620 | return group; |
1da177e4 | 6621 | } |
6711cab4 | 6622 | |
08069033 SS |
6623 | static void init_numa_sched_groups_power(struct sched_group *group_head) |
6624 | { | |
6625 | struct sched_group *sg = group_head; | |
6626 | int j; | |
6627 | ||
6628 | if (!sg) | |
6629 | return; | |
3a5c359a | 6630 | do { |
758b2cdc | 6631 | for_each_cpu(j, sched_group_cpus(sg)) { |
3a5c359a | 6632 | struct sched_domain *sd; |
08069033 | 6633 | |
6c99e9ad | 6634 | sd = &per_cpu(phys_domains, j).sd; |
13318a71 | 6635 | if (j != group_first_cpu(sd->groups)) { |
3a5c359a AK |
6636 | /* |
6637 | * Only add "power" once for each | |
6638 | * physical package. | |
6639 | */ | |
6640 | continue; | |
6641 | } | |
08069033 | 6642 | |
18a3885f | 6643 | sg->cpu_power += sd->groups->cpu_power; |
3a5c359a AK |
6644 | } |
6645 | sg = sg->next; | |
6646 | } while (sg != group_head); | |
08069033 | 6647 | } |
0601a88d AH |
6648 | |
6649 | static int build_numa_sched_groups(struct s_data *d, | |
6650 | const struct cpumask *cpu_map, int num) | |
6651 | { | |
6652 | struct sched_domain *sd; | |
6653 | struct sched_group *sg, *prev; | |
6654 | int n, j; | |
6655 | ||
6656 | cpumask_clear(d->covered); | |
6657 | cpumask_and(d->nodemask, cpumask_of_node(num), cpu_map); | |
6658 | if (cpumask_empty(d->nodemask)) { | |
6659 | d->sched_group_nodes[num] = NULL; | |
6660 | goto out; | |
6661 | } | |
6662 | ||
6663 | sched_domain_node_span(num, d->domainspan); | |
6664 | cpumask_and(d->domainspan, d->domainspan, cpu_map); | |
6665 | ||
6666 | sg = kmalloc_node(sizeof(struct sched_group) + cpumask_size(), | |
6667 | GFP_KERNEL, num); | |
6668 | if (!sg) { | |
3df0fc5b PZ |
6669 | printk(KERN_WARNING "Can not alloc domain group for node %d\n", |
6670 | num); | |
0601a88d AH |
6671 | return -ENOMEM; |
6672 | } | |
6673 | d->sched_group_nodes[num] = sg; | |
6674 | ||
6675 | for_each_cpu(j, d->nodemask) { | |
6676 | sd = &per_cpu(node_domains, j).sd; | |
6677 | sd->groups = sg; | |
6678 | } | |
6679 | ||
18a3885f | 6680 | sg->cpu_power = 0; |
0601a88d AH |
6681 | cpumask_copy(sched_group_cpus(sg), d->nodemask); |
6682 | sg->next = sg; | |
6683 | cpumask_or(d->covered, d->covered, d->nodemask); | |
6684 | ||
6685 | prev = sg; | |
6686 | for (j = 0; j < nr_node_ids; j++) { | |
6687 | n = (num + j) % nr_node_ids; | |
6688 | cpumask_complement(d->notcovered, d->covered); | |
6689 | cpumask_and(d->tmpmask, d->notcovered, cpu_map); | |
6690 | cpumask_and(d->tmpmask, d->tmpmask, d->domainspan); | |
6691 | if (cpumask_empty(d->tmpmask)) | |
6692 | break; | |
6693 | cpumask_and(d->tmpmask, d->tmpmask, cpumask_of_node(n)); | |
6694 | if (cpumask_empty(d->tmpmask)) | |
6695 | continue; | |
6696 | sg = kmalloc_node(sizeof(struct sched_group) + cpumask_size(), | |
6697 | GFP_KERNEL, num); | |
6698 | if (!sg) { | |
3df0fc5b PZ |
6699 | printk(KERN_WARNING |
6700 | "Can not alloc domain group for node %d\n", j); | |
0601a88d AH |
6701 | return -ENOMEM; |
6702 | } | |
18a3885f | 6703 | sg->cpu_power = 0; |
0601a88d AH |
6704 | cpumask_copy(sched_group_cpus(sg), d->tmpmask); |
6705 | sg->next = prev->next; | |
6706 | cpumask_or(d->covered, d->covered, d->tmpmask); | |
6707 | prev->next = sg; | |
6708 | prev = sg; | |
6709 | } | |
6710 | out: | |
6711 | return 0; | |
6712 | } | |
6d6bc0ad | 6713 | #endif /* CONFIG_NUMA */ |
1da177e4 | 6714 | |
a616058b | 6715 | #ifdef CONFIG_NUMA |
51888ca2 | 6716 | /* Free memory allocated for various sched_group structures */ |
96f874e2 RR |
6717 | static void free_sched_groups(const struct cpumask *cpu_map, |
6718 | struct cpumask *nodemask) | |
51888ca2 | 6719 | { |
a616058b | 6720 | int cpu, i; |
51888ca2 | 6721 | |
abcd083a | 6722 | for_each_cpu(cpu, cpu_map) { |
51888ca2 SV |
6723 | struct sched_group **sched_group_nodes |
6724 | = sched_group_nodes_bycpu[cpu]; | |
6725 | ||
51888ca2 SV |
6726 | if (!sched_group_nodes) |
6727 | continue; | |
6728 | ||
076ac2af | 6729 | for (i = 0; i < nr_node_ids; i++) { |
51888ca2 SV |
6730 | struct sched_group *oldsg, *sg = sched_group_nodes[i]; |
6731 | ||
6ca09dfc | 6732 | cpumask_and(nodemask, cpumask_of_node(i), cpu_map); |
96f874e2 | 6733 | if (cpumask_empty(nodemask)) |
51888ca2 SV |
6734 | continue; |
6735 | ||
6736 | if (sg == NULL) | |
6737 | continue; | |
6738 | sg = sg->next; | |
6739 | next_sg: | |
6740 | oldsg = sg; | |
6741 | sg = sg->next; | |
6742 | kfree(oldsg); | |
6743 | if (oldsg != sched_group_nodes[i]) | |
6744 | goto next_sg; | |
6745 | } | |
6746 | kfree(sched_group_nodes); | |
6747 | sched_group_nodes_bycpu[cpu] = NULL; | |
6748 | } | |
51888ca2 | 6749 | } |
6d6bc0ad | 6750 | #else /* !CONFIG_NUMA */ |
96f874e2 RR |
6751 | static void free_sched_groups(const struct cpumask *cpu_map, |
6752 | struct cpumask *nodemask) | |
a616058b SS |
6753 | { |
6754 | } | |
6d6bc0ad | 6755 | #endif /* CONFIG_NUMA */ |
51888ca2 | 6756 | |
89c4710e SS |
6757 | /* |
6758 | * Initialize sched groups cpu_power. | |
6759 | * | |
6760 | * cpu_power indicates the capacity of sched group, which is used while | |
6761 | * distributing the load between different sched groups in a sched domain. | |
6762 | * Typically cpu_power for all the groups in a sched domain will be same unless | |
6763 | * there are asymmetries in the topology. If there are asymmetries, group | |
6764 | * having more cpu_power will pickup more load compared to the group having | |
6765 | * less cpu_power. | |
89c4710e SS |
6766 | */ |
6767 | static void init_sched_groups_power(int cpu, struct sched_domain *sd) | |
6768 | { | |
6769 | struct sched_domain *child; | |
6770 | struct sched_group *group; | |
f93e65c1 PZ |
6771 | long power; |
6772 | int weight; | |
89c4710e SS |
6773 | |
6774 | WARN_ON(!sd || !sd->groups); | |
6775 | ||
13318a71 | 6776 | if (cpu != group_first_cpu(sd->groups)) |
89c4710e SS |
6777 | return; |
6778 | ||
6779 | child = sd->child; | |
6780 | ||
18a3885f | 6781 | sd->groups->cpu_power = 0; |
5517d86b | 6782 | |
f93e65c1 PZ |
6783 | if (!child) { |
6784 | power = SCHED_LOAD_SCALE; | |
6785 | weight = cpumask_weight(sched_domain_span(sd)); | |
6786 | /* | |
6787 | * SMT siblings share the power of a single core. | |
a52bfd73 PZ |
6788 | * Usually multiple threads get a better yield out of |
6789 | * that one core than a single thread would have, | |
6790 | * reflect that in sd->smt_gain. | |
f93e65c1 | 6791 | */ |
a52bfd73 PZ |
6792 | if ((sd->flags & SD_SHARE_CPUPOWER) && weight > 1) { |
6793 | power *= sd->smt_gain; | |
f93e65c1 | 6794 | power /= weight; |
a52bfd73 PZ |
6795 | power >>= SCHED_LOAD_SHIFT; |
6796 | } | |
18a3885f | 6797 | sd->groups->cpu_power += power; |
89c4710e SS |
6798 | return; |
6799 | } | |
6800 | ||
89c4710e | 6801 | /* |
f93e65c1 | 6802 | * Add cpu_power of each child group to this groups cpu_power. |
89c4710e SS |
6803 | */ |
6804 | group = child->groups; | |
6805 | do { | |
18a3885f | 6806 | sd->groups->cpu_power += group->cpu_power; |
89c4710e SS |
6807 | group = group->next; |
6808 | } while (group != child->groups); | |
6809 | } | |
6810 | ||
7c16ec58 MT |
6811 | /* |
6812 | * Initializers for schedule domains | |
6813 | * Non-inlined to reduce accumulated stack pressure in build_sched_domains() | |
6814 | */ | |
6815 | ||
a5d8c348 IM |
6816 | #ifdef CONFIG_SCHED_DEBUG |
6817 | # define SD_INIT_NAME(sd, type) sd->name = #type | |
6818 | #else | |
6819 | # define SD_INIT_NAME(sd, type) do { } while (0) | |
6820 | #endif | |
6821 | ||
7c16ec58 | 6822 | #define SD_INIT(sd, type) sd_init_##type(sd) |
a5d8c348 | 6823 | |
7c16ec58 MT |
6824 | #define SD_INIT_FUNC(type) \ |
6825 | static noinline void sd_init_##type(struct sched_domain *sd) \ | |
6826 | { \ | |
6827 | memset(sd, 0, sizeof(*sd)); \ | |
6828 | *sd = SD_##type##_INIT; \ | |
1d3504fc | 6829 | sd->level = SD_LV_##type; \ |
a5d8c348 | 6830 | SD_INIT_NAME(sd, type); \ |
7c16ec58 MT |
6831 | } |
6832 | ||
6833 | SD_INIT_FUNC(CPU) | |
6834 | #ifdef CONFIG_NUMA | |
6835 | SD_INIT_FUNC(ALLNODES) | |
6836 | SD_INIT_FUNC(NODE) | |
6837 | #endif | |
6838 | #ifdef CONFIG_SCHED_SMT | |
6839 | SD_INIT_FUNC(SIBLING) | |
6840 | #endif | |
6841 | #ifdef CONFIG_SCHED_MC | |
6842 | SD_INIT_FUNC(MC) | |
6843 | #endif | |
6844 | ||
1d3504fc HS |
6845 | static int default_relax_domain_level = -1; |
6846 | ||
6847 | static int __init setup_relax_domain_level(char *str) | |
6848 | { | |
30e0e178 LZ |
6849 | unsigned long val; |
6850 | ||
6851 | val = simple_strtoul(str, NULL, 0); | |
6852 | if (val < SD_LV_MAX) | |
6853 | default_relax_domain_level = val; | |
6854 | ||
1d3504fc HS |
6855 | return 1; |
6856 | } | |
6857 | __setup("relax_domain_level=", setup_relax_domain_level); | |
6858 | ||
6859 | static void set_domain_attribute(struct sched_domain *sd, | |
6860 | struct sched_domain_attr *attr) | |
6861 | { | |
6862 | int request; | |
6863 | ||
6864 | if (!attr || attr->relax_domain_level < 0) { | |
6865 | if (default_relax_domain_level < 0) | |
6866 | return; | |
6867 | else | |
6868 | request = default_relax_domain_level; | |
6869 | } else | |
6870 | request = attr->relax_domain_level; | |
6871 | if (request < sd->level) { | |
6872 | /* turn off idle balance on this domain */ | |
c88d5910 | 6873 | sd->flags &= ~(SD_BALANCE_WAKE|SD_BALANCE_NEWIDLE); |
1d3504fc HS |
6874 | } else { |
6875 | /* turn on idle balance on this domain */ | |
c88d5910 | 6876 | sd->flags |= (SD_BALANCE_WAKE|SD_BALANCE_NEWIDLE); |
1d3504fc HS |
6877 | } |
6878 | } | |
6879 | ||
2109b99e AH |
6880 | static void __free_domain_allocs(struct s_data *d, enum s_alloc what, |
6881 | const struct cpumask *cpu_map) | |
6882 | { | |
6883 | switch (what) { | |
6884 | case sa_sched_groups: | |
6885 | free_sched_groups(cpu_map, d->tmpmask); /* fall through */ | |
6886 | d->sched_group_nodes = NULL; | |
6887 | case sa_rootdomain: | |
6888 | free_rootdomain(d->rd); /* fall through */ | |
6889 | case sa_tmpmask: | |
6890 | free_cpumask_var(d->tmpmask); /* fall through */ | |
6891 | case sa_send_covered: | |
6892 | free_cpumask_var(d->send_covered); /* fall through */ | |
6893 | case sa_this_core_map: | |
6894 | free_cpumask_var(d->this_core_map); /* fall through */ | |
6895 | case sa_this_sibling_map: | |
6896 | free_cpumask_var(d->this_sibling_map); /* fall through */ | |
6897 | case sa_nodemask: | |
6898 | free_cpumask_var(d->nodemask); /* fall through */ | |
6899 | case sa_sched_group_nodes: | |
d1b55138 | 6900 | #ifdef CONFIG_NUMA |
2109b99e AH |
6901 | kfree(d->sched_group_nodes); /* fall through */ |
6902 | case sa_notcovered: | |
6903 | free_cpumask_var(d->notcovered); /* fall through */ | |
6904 | case sa_covered: | |
6905 | free_cpumask_var(d->covered); /* fall through */ | |
6906 | case sa_domainspan: | |
6907 | free_cpumask_var(d->domainspan); /* fall through */ | |
3404c8d9 | 6908 | #endif |
2109b99e AH |
6909 | case sa_none: |
6910 | break; | |
6911 | } | |
6912 | } | |
3404c8d9 | 6913 | |
2109b99e AH |
6914 | static enum s_alloc __visit_domain_allocation_hell(struct s_data *d, |
6915 | const struct cpumask *cpu_map) | |
6916 | { | |
3404c8d9 | 6917 | #ifdef CONFIG_NUMA |
2109b99e AH |
6918 | if (!alloc_cpumask_var(&d->domainspan, GFP_KERNEL)) |
6919 | return sa_none; | |
6920 | if (!alloc_cpumask_var(&d->covered, GFP_KERNEL)) | |
6921 | return sa_domainspan; | |
6922 | if (!alloc_cpumask_var(&d->notcovered, GFP_KERNEL)) | |
6923 | return sa_covered; | |
6924 | /* Allocate the per-node list of sched groups */ | |
6925 | d->sched_group_nodes = kcalloc(nr_node_ids, | |
6926 | sizeof(struct sched_group *), GFP_KERNEL); | |
6927 | if (!d->sched_group_nodes) { | |
3df0fc5b | 6928 | printk(KERN_WARNING "Can not alloc sched group node list\n"); |
2109b99e | 6929 | return sa_notcovered; |
d1b55138 | 6930 | } |
2109b99e | 6931 | sched_group_nodes_bycpu[cpumask_first(cpu_map)] = d->sched_group_nodes; |
d1b55138 | 6932 | #endif |
2109b99e AH |
6933 | if (!alloc_cpumask_var(&d->nodemask, GFP_KERNEL)) |
6934 | return sa_sched_group_nodes; | |
6935 | if (!alloc_cpumask_var(&d->this_sibling_map, GFP_KERNEL)) | |
6936 | return sa_nodemask; | |
6937 | if (!alloc_cpumask_var(&d->this_core_map, GFP_KERNEL)) | |
6938 | return sa_this_sibling_map; | |
6939 | if (!alloc_cpumask_var(&d->send_covered, GFP_KERNEL)) | |
6940 | return sa_this_core_map; | |
6941 | if (!alloc_cpumask_var(&d->tmpmask, GFP_KERNEL)) | |
6942 | return sa_send_covered; | |
6943 | d->rd = alloc_rootdomain(); | |
6944 | if (!d->rd) { | |
3df0fc5b | 6945 | printk(KERN_WARNING "Cannot alloc root domain\n"); |
2109b99e | 6946 | return sa_tmpmask; |
57d885fe | 6947 | } |
2109b99e AH |
6948 | return sa_rootdomain; |
6949 | } | |
57d885fe | 6950 | |
7f4588f3 AH |
6951 | static struct sched_domain *__build_numa_sched_domains(struct s_data *d, |
6952 | const struct cpumask *cpu_map, struct sched_domain_attr *attr, int i) | |
6953 | { | |
6954 | struct sched_domain *sd = NULL; | |
7c16ec58 | 6955 | #ifdef CONFIG_NUMA |
7f4588f3 | 6956 | struct sched_domain *parent; |
1da177e4 | 6957 | |
7f4588f3 AH |
6958 | d->sd_allnodes = 0; |
6959 | if (cpumask_weight(cpu_map) > | |
6960 | SD_NODES_PER_DOMAIN * cpumask_weight(d->nodemask)) { | |
6961 | sd = &per_cpu(allnodes_domains, i).sd; | |
6962 | SD_INIT(sd, ALLNODES); | |
1d3504fc | 6963 | set_domain_attribute(sd, attr); |
7f4588f3 AH |
6964 | cpumask_copy(sched_domain_span(sd), cpu_map); |
6965 | cpu_to_allnodes_group(i, cpu_map, &sd->groups, d->tmpmask); | |
6966 | d->sd_allnodes = 1; | |
6967 | } | |
6968 | parent = sd; | |
6969 | ||
6970 | sd = &per_cpu(node_domains, i).sd; | |
6971 | SD_INIT(sd, NODE); | |
6972 | set_domain_attribute(sd, attr); | |
6973 | sched_domain_node_span(cpu_to_node(i), sched_domain_span(sd)); | |
6974 | sd->parent = parent; | |
6975 | if (parent) | |
6976 | parent->child = sd; | |
6977 | cpumask_and(sched_domain_span(sd), sched_domain_span(sd), cpu_map); | |
1da177e4 | 6978 | #endif |
7f4588f3 AH |
6979 | return sd; |
6980 | } | |
1da177e4 | 6981 | |
87cce662 AH |
6982 | static struct sched_domain *__build_cpu_sched_domain(struct s_data *d, |
6983 | const struct cpumask *cpu_map, struct sched_domain_attr *attr, | |
6984 | struct sched_domain *parent, int i) | |
6985 | { | |
6986 | struct sched_domain *sd; | |
6987 | sd = &per_cpu(phys_domains, i).sd; | |
6988 | SD_INIT(sd, CPU); | |
6989 | set_domain_attribute(sd, attr); | |
6990 | cpumask_copy(sched_domain_span(sd), d->nodemask); | |
6991 | sd->parent = parent; | |
6992 | if (parent) | |
6993 | parent->child = sd; | |
6994 | cpu_to_phys_group(i, cpu_map, &sd->groups, d->tmpmask); | |
6995 | return sd; | |
6996 | } | |
1da177e4 | 6997 | |
410c4081 AH |
6998 | static struct sched_domain *__build_mc_sched_domain(struct s_data *d, |
6999 | const struct cpumask *cpu_map, struct sched_domain_attr *attr, | |
7000 | struct sched_domain *parent, int i) | |
7001 | { | |
7002 | struct sched_domain *sd = parent; | |
1e9f28fa | 7003 | #ifdef CONFIG_SCHED_MC |
410c4081 AH |
7004 | sd = &per_cpu(core_domains, i).sd; |
7005 | SD_INIT(sd, MC); | |
7006 | set_domain_attribute(sd, attr); | |
7007 | cpumask_and(sched_domain_span(sd), cpu_map, cpu_coregroup_mask(i)); | |
7008 | sd->parent = parent; | |
7009 | parent->child = sd; | |
7010 | cpu_to_core_group(i, cpu_map, &sd->groups, d->tmpmask); | |
1e9f28fa | 7011 | #endif |
410c4081 AH |
7012 | return sd; |
7013 | } | |
1e9f28fa | 7014 | |
d8173535 AH |
7015 | static struct sched_domain *__build_smt_sched_domain(struct s_data *d, |
7016 | const struct cpumask *cpu_map, struct sched_domain_attr *attr, | |
7017 | struct sched_domain *parent, int i) | |
7018 | { | |
7019 | struct sched_domain *sd = parent; | |
1da177e4 | 7020 | #ifdef CONFIG_SCHED_SMT |
d8173535 AH |
7021 | sd = &per_cpu(cpu_domains, i).sd; |
7022 | SD_INIT(sd, SIBLING); | |
7023 | set_domain_attribute(sd, attr); | |
7024 | cpumask_and(sched_domain_span(sd), cpu_map, topology_thread_cpumask(i)); | |
7025 | sd->parent = parent; | |
7026 | parent->child = sd; | |
7027 | cpu_to_cpu_group(i, cpu_map, &sd->groups, d->tmpmask); | |
1da177e4 | 7028 | #endif |
d8173535 AH |
7029 | return sd; |
7030 | } | |
1da177e4 | 7031 | |
0e8e85c9 AH |
7032 | static void build_sched_groups(struct s_data *d, enum sched_domain_level l, |
7033 | const struct cpumask *cpu_map, int cpu) | |
7034 | { | |
7035 | switch (l) { | |
1da177e4 | 7036 | #ifdef CONFIG_SCHED_SMT |
0e8e85c9 AH |
7037 | case SD_LV_SIBLING: /* set up CPU (sibling) groups */ |
7038 | cpumask_and(d->this_sibling_map, cpu_map, | |
7039 | topology_thread_cpumask(cpu)); | |
7040 | if (cpu == cpumask_first(d->this_sibling_map)) | |
7041 | init_sched_build_groups(d->this_sibling_map, cpu_map, | |
7042 | &cpu_to_cpu_group, | |
7043 | d->send_covered, d->tmpmask); | |
7044 | break; | |
1da177e4 | 7045 | #endif |
1e9f28fa | 7046 | #ifdef CONFIG_SCHED_MC |
a2af04cd AH |
7047 | case SD_LV_MC: /* set up multi-core groups */ |
7048 | cpumask_and(d->this_core_map, cpu_map, cpu_coregroup_mask(cpu)); | |
7049 | if (cpu == cpumask_first(d->this_core_map)) | |
7050 | init_sched_build_groups(d->this_core_map, cpu_map, | |
7051 | &cpu_to_core_group, | |
7052 | d->send_covered, d->tmpmask); | |
7053 | break; | |
1e9f28fa | 7054 | #endif |
86548096 AH |
7055 | case SD_LV_CPU: /* set up physical groups */ |
7056 | cpumask_and(d->nodemask, cpumask_of_node(cpu), cpu_map); | |
7057 | if (!cpumask_empty(d->nodemask)) | |
7058 | init_sched_build_groups(d->nodemask, cpu_map, | |
7059 | &cpu_to_phys_group, | |
7060 | d->send_covered, d->tmpmask); | |
7061 | break; | |
1da177e4 | 7062 | #ifdef CONFIG_NUMA |
de616e36 AH |
7063 | case SD_LV_ALLNODES: |
7064 | init_sched_build_groups(cpu_map, cpu_map, &cpu_to_allnodes_group, | |
7065 | d->send_covered, d->tmpmask); | |
7066 | break; | |
7067 | #endif | |
0e8e85c9 AH |
7068 | default: |
7069 | break; | |
7c16ec58 | 7070 | } |
0e8e85c9 | 7071 | } |
9c1cfda2 | 7072 | |
2109b99e AH |
7073 | /* |
7074 | * Build sched domains for a given set of cpus and attach the sched domains | |
7075 | * to the individual cpus | |
7076 | */ | |
7077 | static int __build_sched_domains(const struct cpumask *cpu_map, | |
7078 | struct sched_domain_attr *attr) | |
7079 | { | |
7080 | enum s_alloc alloc_state = sa_none; | |
7081 | struct s_data d; | |
294b0c96 | 7082 | struct sched_domain *sd; |
2109b99e | 7083 | int i; |
7c16ec58 | 7084 | #ifdef CONFIG_NUMA |
2109b99e | 7085 | d.sd_allnodes = 0; |
7c16ec58 | 7086 | #endif |
9c1cfda2 | 7087 | |
2109b99e AH |
7088 | alloc_state = __visit_domain_allocation_hell(&d, cpu_map); |
7089 | if (alloc_state != sa_rootdomain) | |
7090 | goto error; | |
7091 | alloc_state = sa_sched_groups; | |
9c1cfda2 | 7092 | |
1da177e4 | 7093 | /* |
1a20ff27 | 7094 | * Set up domains for cpus specified by the cpu_map. |
1da177e4 | 7095 | */ |
abcd083a | 7096 | for_each_cpu(i, cpu_map) { |
49a02c51 AH |
7097 | cpumask_and(d.nodemask, cpumask_of_node(cpu_to_node(i)), |
7098 | cpu_map); | |
9761eea8 | 7099 | |
7f4588f3 | 7100 | sd = __build_numa_sched_domains(&d, cpu_map, attr, i); |
87cce662 | 7101 | sd = __build_cpu_sched_domain(&d, cpu_map, attr, sd, i); |
410c4081 | 7102 | sd = __build_mc_sched_domain(&d, cpu_map, attr, sd, i); |
d8173535 | 7103 | sd = __build_smt_sched_domain(&d, cpu_map, attr, sd, i); |
1da177e4 | 7104 | } |
9c1cfda2 | 7105 | |
abcd083a | 7106 | for_each_cpu(i, cpu_map) { |
0e8e85c9 | 7107 | build_sched_groups(&d, SD_LV_SIBLING, cpu_map, i); |
a2af04cd | 7108 | build_sched_groups(&d, SD_LV_MC, cpu_map, i); |
1da177e4 | 7109 | } |
9c1cfda2 | 7110 | |
1da177e4 | 7111 | /* Set up physical groups */ |
86548096 AH |
7112 | for (i = 0; i < nr_node_ids; i++) |
7113 | build_sched_groups(&d, SD_LV_CPU, cpu_map, i); | |
9c1cfda2 | 7114 | |
1da177e4 LT |
7115 | #ifdef CONFIG_NUMA |
7116 | /* Set up node groups */ | |
de616e36 AH |
7117 | if (d.sd_allnodes) |
7118 | build_sched_groups(&d, SD_LV_ALLNODES, cpu_map, 0); | |
9c1cfda2 | 7119 | |
0601a88d AH |
7120 | for (i = 0; i < nr_node_ids; i++) |
7121 | if (build_numa_sched_groups(&d, cpu_map, i)) | |
51888ca2 | 7122 | goto error; |
1da177e4 LT |
7123 | #endif |
7124 | ||
7125 | /* Calculate CPU power for physical packages and nodes */ | |
5c45bf27 | 7126 | #ifdef CONFIG_SCHED_SMT |
abcd083a | 7127 | for_each_cpu(i, cpu_map) { |
294b0c96 | 7128 | sd = &per_cpu(cpu_domains, i).sd; |
89c4710e | 7129 | init_sched_groups_power(i, sd); |
5c45bf27 | 7130 | } |
1da177e4 | 7131 | #endif |
1e9f28fa | 7132 | #ifdef CONFIG_SCHED_MC |
abcd083a | 7133 | for_each_cpu(i, cpu_map) { |
294b0c96 | 7134 | sd = &per_cpu(core_domains, i).sd; |
89c4710e | 7135 | init_sched_groups_power(i, sd); |
5c45bf27 SS |
7136 | } |
7137 | #endif | |
1e9f28fa | 7138 | |
abcd083a | 7139 | for_each_cpu(i, cpu_map) { |
294b0c96 | 7140 | sd = &per_cpu(phys_domains, i).sd; |
89c4710e | 7141 | init_sched_groups_power(i, sd); |
1da177e4 LT |
7142 | } |
7143 | ||
9c1cfda2 | 7144 | #ifdef CONFIG_NUMA |
076ac2af | 7145 | for (i = 0; i < nr_node_ids; i++) |
49a02c51 | 7146 | init_numa_sched_groups_power(d.sched_group_nodes[i]); |
9c1cfda2 | 7147 | |
49a02c51 | 7148 | if (d.sd_allnodes) { |
6711cab4 | 7149 | struct sched_group *sg; |
f712c0c7 | 7150 | |
96f874e2 | 7151 | cpu_to_allnodes_group(cpumask_first(cpu_map), cpu_map, &sg, |
49a02c51 | 7152 | d.tmpmask); |
f712c0c7 SS |
7153 | init_numa_sched_groups_power(sg); |
7154 | } | |
9c1cfda2 JH |
7155 | #endif |
7156 | ||
1da177e4 | 7157 | /* Attach the domains */ |
abcd083a | 7158 | for_each_cpu(i, cpu_map) { |
1da177e4 | 7159 | #ifdef CONFIG_SCHED_SMT |
6c99e9ad | 7160 | sd = &per_cpu(cpu_domains, i).sd; |
1e9f28fa | 7161 | #elif defined(CONFIG_SCHED_MC) |
6c99e9ad | 7162 | sd = &per_cpu(core_domains, i).sd; |
1da177e4 | 7163 | #else |
6c99e9ad | 7164 | sd = &per_cpu(phys_domains, i).sd; |
1da177e4 | 7165 | #endif |
49a02c51 | 7166 | cpu_attach_domain(sd, d.rd, i); |
1da177e4 | 7167 | } |
51888ca2 | 7168 | |
2109b99e AH |
7169 | d.sched_group_nodes = NULL; /* don't free this we still need it */ |
7170 | __free_domain_allocs(&d, sa_tmpmask, cpu_map); | |
7171 | return 0; | |
51888ca2 | 7172 | |
51888ca2 | 7173 | error: |
2109b99e AH |
7174 | __free_domain_allocs(&d, alloc_state, cpu_map); |
7175 | return -ENOMEM; | |
1da177e4 | 7176 | } |
029190c5 | 7177 | |
96f874e2 | 7178 | static int build_sched_domains(const struct cpumask *cpu_map) |
1d3504fc HS |
7179 | { |
7180 | return __build_sched_domains(cpu_map, NULL); | |
7181 | } | |
7182 | ||
acc3f5d7 | 7183 | static cpumask_var_t *doms_cur; /* current sched domains */ |
029190c5 | 7184 | static int ndoms_cur; /* number of sched domains in 'doms_cur' */ |
4285f594 IM |
7185 | static struct sched_domain_attr *dattr_cur; |
7186 | /* attribues of custom domains in 'doms_cur' */ | |
029190c5 PJ |
7187 | |
7188 | /* | |
7189 | * Special case: If a kmalloc of a doms_cur partition (array of | |
4212823f RR |
7190 | * cpumask) fails, then fallback to a single sched domain, |
7191 | * as determined by the single cpumask fallback_doms. | |
029190c5 | 7192 | */ |
4212823f | 7193 | static cpumask_var_t fallback_doms; |
029190c5 | 7194 | |
ee79d1bd HC |
7195 | /* |
7196 | * arch_update_cpu_topology lets virtualized architectures update the | |
7197 | * cpu core maps. It is supposed to return 1 if the topology changed | |
7198 | * or 0 if it stayed the same. | |
7199 | */ | |
7200 | int __attribute__((weak)) arch_update_cpu_topology(void) | |
22e52b07 | 7201 | { |
ee79d1bd | 7202 | return 0; |
22e52b07 HC |
7203 | } |
7204 | ||
acc3f5d7 RR |
7205 | cpumask_var_t *alloc_sched_domains(unsigned int ndoms) |
7206 | { | |
7207 | int i; | |
7208 | cpumask_var_t *doms; | |
7209 | ||
7210 | doms = kmalloc(sizeof(*doms) * ndoms, GFP_KERNEL); | |
7211 | if (!doms) | |
7212 | return NULL; | |
7213 | for (i = 0; i < ndoms; i++) { | |
7214 | if (!alloc_cpumask_var(&doms[i], GFP_KERNEL)) { | |
7215 | free_sched_domains(doms, i); | |
7216 | return NULL; | |
7217 | } | |
7218 | } | |
7219 | return doms; | |
7220 | } | |
7221 | ||
7222 | void free_sched_domains(cpumask_var_t doms[], unsigned int ndoms) | |
7223 | { | |
7224 | unsigned int i; | |
7225 | for (i = 0; i < ndoms; i++) | |
7226 | free_cpumask_var(doms[i]); | |
7227 | kfree(doms); | |
7228 | } | |
7229 | ||
1a20ff27 | 7230 | /* |
41a2d6cf | 7231 | * Set up scheduler domains and groups. Callers must hold the hotplug lock. |
029190c5 PJ |
7232 | * For now this just excludes isolated cpus, but could be used to |
7233 | * exclude other special cases in the future. | |
1a20ff27 | 7234 | */ |
96f874e2 | 7235 | static int arch_init_sched_domains(const struct cpumask *cpu_map) |
1a20ff27 | 7236 | { |
7378547f MM |
7237 | int err; |
7238 | ||
22e52b07 | 7239 | arch_update_cpu_topology(); |
029190c5 | 7240 | ndoms_cur = 1; |
acc3f5d7 | 7241 | doms_cur = alloc_sched_domains(ndoms_cur); |
029190c5 | 7242 | if (!doms_cur) |
acc3f5d7 RR |
7243 | doms_cur = &fallback_doms; |
7244 | cpumask_andnot(doms_cur[0], cpu_map, cpu_isolated_map); | |
1d3504fc | 7245 | dattr_cur = NULL; |
acc3f5d7 | 7246 | err = build_sched_domains(doms_cur[0]); |
6382bc90 | 7247 | register_sched_domain_sysctl(); |
7378547f MM |
7248 | |
7249 | return err; | |
1a20ff27 DG |
7250 | } |
7251 | ||
96f874e2 RR |
7252 | static void arch_destroy_sched_domains(const struct cpumask *cpu_map, |
7253 | struct cpumask *tmpmask) | |
1da177e4 | 7254 | { |
7c16ec58 | 7255 | free_sched_groups(cpu_map, tmpmask); |
9c1cfda2 | 7256 | } |
1da177e4 | 7257 | |
1a20ff27 DG |
7258 | /* |
7259 | * Detach sched domains from a group of cpus specified in cpu_map | |
7260 | * These cpus will now be attached to the NULL domain | |
7261 | */ | |
96f874e2 | 7262 | static void detach_destroy_domains(const struct cpumask *cpu_map) |
1a20ff27 | 7263 | { |
96f874e2 RR |
7264 | /* Save because hotplug lock held. */ |
7265 | static DECLARE_BITMAP(tmpmask, CONFIG_NR_CPUS); | |
1a20ff27 DG |
7266 | int i; |
7267 | ||
abcd083a | 7268 | for_each_cpu(i, cpu_map) |
57d885fe | 7269 | cpu_attach_domain(NULL, &def_root_domain, i); |
1a20ff27 | 7270 | synchronize_sched(); |
96f874e2 | 7271 | arch_destroy_sched_domains(cpu_map, to_cpumask(tmpmask)); |
1a20ff27 DG |
7272 | } |
7273 | ||
1d3504fc HS |
7274 | /* handle null as "default" */ |
7275 | static int dattrs_equal(struct sched_domain_attr *cur, int idx_cur, | |
7276 | struct sched_domain_attr *new, int idx_new) | |
7277 | { | |
7278 | struct sched_domain_attr tmp; | |
7279 | ||
7280 | /* fast path */ | |
7281 | if (!new && !cur) | |
7282 | return 1; | |
7283 | ||
7284 | tmp = SD_ATTR_INIT; | |
7285 | return !memcmp(cur ? (cur + idx_cur) : &tmp, | |
7286 | new ? (new + idx_new) : &tmp, | |
7287 | sizeof(struct sched_domain_attr)); | |
7288 | } | |
7289 | ||
029190c5 PJ |
7290 | /* |
7291 | * Partition sched domains as specified by the 'ndoms_new' | |
41a2d6cf | 7292 | * cpumasks in the array doms_new[] of cpumasks. This compares |
029190c5 PJ |
7293 | * doms_new[] to the current sched domain partitioning, doms_cur[]. |
7294 | * It destroys each deleted domain and builds each new domain. | |
7295 | * | |
acc3f5d7 | 7296 | * 'doms_new' is an array of cpumask_var_t's of length 'ndoms_new'. |
41a2d6cf IM |
7297 | * The masks don't intersect (don't overlap.) We should setup one |
7298 | * sched domain for each mask. CPUs not in any of the cpumasks will | |
7299 | * not be load balanced. If the same cpumask appears both in the | |
029190c5 PJ |
7300 | * current 'doms_cur' domains and in the new 'doms_new', we can leave |
7301 | * it as it is. | |
7302 | * | |
acc3f5d7 RR |
7303 | * The passed in 'doms_new' should be allocated using |
7304 | * alloc_sched_domains. This routine takes ownership of it and will | |
7305 | * free_sched_domains it when done with it. If the caller failed the | |
7306 | * alloc call, then it can pass in doms_new == NULL && ndoms_new == 1, | |
7307 | * and partition_sched_domains() will fallback to the single partition | |
7308 | * 'fallback_doms', it also forces the domains to be rebuilt. | |
029190c5 | 7309 | * |
96f874e2 | 7310 | * If doms_new == NULL it will be replaced with cpu_online_mask. |
700018e0 LZ |
7311 | * ndoms_new == 0 is a special case for destroying existing domains, |
7312 | * and it will not create the default domain. | |
dfb512ec | 7313 | * |
029190c5 PJ |
7314 | * Call with hotplug lock held |
7315 | */ | |
acc3f5d7 | 7316 | void partition_sched_domains(int ndoms_new, cpumask_var_t doms_new[], |
1d3504fc | 7317 | struct sched_domain_attr *dattr_new) |
029190c5 | 7318 | { |
dfb512ec | 7319 | int i, j, n; |
d65bd5ec | 7320 | int new_topology; |
029190c5 | 7321 | |
712555ee | 7322 | mutex_lock(&sched_domains_mutex); |
a1835615 | 7323 | |
7378547f MM |
7324 | /* always unregister in case we don't destroy any domains */ |
7325 | unregister_sched_domain_sysctl(); | |
7326 | ||
d65bd5ec HC |
7327 | /* Let architecture update cpu core mappings. */ |
7328 | new_topology = arch_update_cpu_topology(); | |
7329 | ||
dfb512ec | 7330 | n = doms_new ? ndoms_new : 0; |
029190c5 PJ |
7331 | |
7332 | /* Destroy deleted domains */ | |
7333 | for (i = 0; i < ndoms_cur; i++) { | |
d65bd5ec | 7334 | for (j = 0; j < n && !new_topology; j++) { |
acc3f5d7 | 7335 | if (cpumask_equal(doms_cur[i], doms_new[j]) |
1d3504fc | 7336 | && dattrs_equal(dattr_cur, i, dattr_new, j)) |
029190c5 PJ |
7337 | goto match1; |
7338 | } | |
7339 | /* no match - a current sched domain not in new doms_new[] */ | |
acc3f5d7 | 7340 | detach_destroy_domains(doms_cur[i]); |
029190c5 PJ |
7341 | match1: |
7342 | ; | |
7343 | } | |
7344 | ||
e761b772 MK |
7345 | if (doms_new == NULL) { |
7346 | ndoms_cur = 0; | |
acc3f5d7 | 7347 | doms_new = &fallback_doms; |
6ad4c188 | 7348 | cpumask_andnot(doms_new[0], cpu_active_mask, cpu_isolated_map); |
faa2f98f | 7349 | WARN_ON_ONCE(dattr_new); |
e761b772 MK |
7350 | } |
7351 | ||
029190c5 PJ |
7352 | /* Build new domains */ |
7353 | for (i = 0; i < ndoms_new; i++) { | |
d65bd5ec | 7354 | for (j = 0; j < ndoms_cur && !new_topology; j++) { |
acc3f5d7 | 7355 | if (cpumask_equal(doms_new[i], doms_cur[j]) |
1d3504fc | 7356 | && dattrs_equal(dattr_new, i, dattr_cur, j)) |
029190c5 PJ |
7357 | goto match2; |
7358 | } | |
7359 | /* no match - add a new doms_new */ | |
acc3f5d7 | 7360 | __build_sched_domains(doms_new[i], |
1d3504fc | 7361 | dattr_new ? dattr_new + i : NULL); |
029190c5 PJ |
7362 | match2: |
7363 | ; | |
7364 | } | |
7365 | ||
7366 | /* Remember the new sched domains */ | |
acc3f5d7 RR |
7367 | if (doms_cur != &fallback_doms) |
7368 | free_sched_domains(doms_cur, ndoms_cur); | |
1d3504fc | 7369 | kfree(dattr_cur); /* kfree(NULL) is safe */ |
029190c5 | 7370 | doms_cur = doms_new; |
1d3504fc | 7371 | dattr_cur = dattr_new; |
029190c5 | 7372 | ndoms_cur = ndoms_new; |
7378547f MM |
7373 | |
7374 | register_sched_domain_sysctl(); | |
a1835615 | 7375 | |
712555ee | 7376 | mutex_unlock(&sched_domains_mutex); |
029190c5 PJ |
7377 | } |
7378 | ||
5c45bf27 | 7379 | #if defined(CONFIG_SCHED_MC) || defined(CONFIG_SCHED_SMT) |
c70f22d2 | 7380 | static void arch_reinit_sched_domains(void) |
5c45bf27 | 7381 | { |
95402b38 | 7382 | get_online_cpus(); |
dfb512ec MK |
7383 | |
7384 | /* Destroy domains first to force the rebuild */ | |
7385 | partition_sched_domains(0, NULL, NULL); | |
7386 | ||
e761b772 | 7387 | rebuild_sched_domains(); |
95402b38 | 7388 | put_online_cpus(); |
5c45bf27 SS |
7389 | } |
7390 | ||
7391 | static ssize_t sched_power_savings_store(const char *buf, size_t count, int smt) | |
7392 | { | |
afb8a9b7 | 7393 | unsigned int level = 0; |
5c45bf27 | 7394 | |
afb8a9b7 GS |
7395 | if (sscanf(buf, "%u", &level) != 1) |
7396 | return -EINVAL; | |
7397 | ||
7398 | /* | |
7399 | * level is always be positive so don't check for | |
7400 | * level < POWERSAVINGS_BALANCE_NONE which is 0 | |
7401 | * What happens on 0 or 1 byte write, | |
7402 | * need to check for count as well? | |
7403 | */ | |
7404 | ||
7405 | if (level >= MAX_POWERSAVINGS_BALANCE_LEVELS) | |
5c45bf27 SS |
7406 | return -EINVAL; |
7407 | ||
7408 | if (smt) | |
afb8a9b7 | 7409 | sched_smt_power_savings = level; |
5c45bf27 | 7410 | else |
afb8a9b7 | 7411 | sched_mc_power_savings = level; |
5c45bf27 | 7412 | |
c70f22d2 | 7413 | arch_reinit_sched_domains(); |
5c45bf27 | 7414 | |
c70f22d2 | 7415 | return count; |
5c45bf27 SS |
7416 | } |
7417 | ||
5c45bf27 | 7418 | #ifdef CONFIG_SCHED_MC |
f718cd4a | 7419 | static ssize_t sched_mc_power_savings_show(struct sysdev_class *class, |
c9be0a36 | 7420 | struct sysdev_class_attribute *attr, |
f718cd4a | 7421 | char *page) |
5c45bf27 SS |
7422 | { |
7423 | return sprintf(page, "%u\n", sched_mc_power_savings); | |
7424 | } | |
f718cd4a | 7425 | static ssize_t sched_mc_power_savings_store(struct sysdev_class *class, |
c9be0a36 | 7426 | struct sysdev_class_attribute *attr, |
48f24c4d | 7427 | const char *buf, size_t count) |
5c45bf27 SS |
7428 | { |
7429 | return sched_power_savings_store(buf, count, 0); | |
7430 | } | |
f718cd4a AK |
7431 | static SYSDEV_CLASS_ATTR(sched_mc_power_savings, 0644, |
7432 | sched_mc_power_savings_show, | |
7433 | sched_mc_power_savings_store); | |
5c45bf27 SS |
7434 | #endif |
7435 | ||
7436 | #ifdef CONFIG_SCHED_SMT | |
f718cd4a | 7437 | static ssize_t sched_smt_power_savings_show(struct sysdev_class *dev, |
c9be0a36 | 7438 | struct sysdev_class_attribute *attr, |
f718cd4a | 7439 | char *page) |
5c45bf27 SS |
7440 | { |
7441 | return sprintf(page, "%u\n", sched_smt_power_savings); | |
7442 | } | |
f718cd4a | 7443 | static ssize_t sched_smt_power_savings_store(struct sysdev_class *dev, |
c9be0a36 | 7444 | struct sysdev_class_attribute *attr, |
48f24c4d | 7445 | const char *buf, size_t count) |
5c45bf27 SS |
7446 | { |
7447 | return sched_power_savings_store(buf, count, 1); | |
7448 | } | |
f718cd4a AK |
7449 | static SYSDEV_CLASS_ATTR(sched_smt_power_savings, 0644, |
7450 | sched_smt_power_savings_show, | |
6707de00 AB |
7451 | sched_smt_power_savings_store); |
7452 | #endif | |
7453 | ||
39aac648 | 7454 | int __init sched_create_sysfs_power_savings_entries(struct sysdev_class *cls) |
6707de00 AB |
7455 | { |
7456 | int err = 0; | |
7457 | ||
7458 | #ifdef CONFIG_SCHED_SMT | |
7459 | if (smt_capable()) | |
7460 | err = sysfs_create_file(&cls->kset.kobj, | |
7461 | &attr_sched_smt_power_savings.attr); | |
7462 | #endif | |
7463 | #ifdef CONFIG_SCHED_MC | |
7464 | if (!err && mc_capable()) | |
7465 | err = sysfs_create_file(&cls->kset.kobj, | |
7466 | &attr_sched_mc_power_savings.attr); | |
7467 | #endif | |
7468 | return err; | |
7469 | } | |
6d6bc0ad | 7470 | #endif /* CONFIG_SCHED_MC || CONFIG_SCHED_SMT */ |
5c45bf27 | 7471 | |
1da177e4 | 7472 | /* |
3a101d05 TH |
7473 | * Update cpusets according to cpu_active mask. If cpusets are |
7474 | * disabled, cpuset_update_active_cpus() becomes a simple wrapper | |
7475 | * around partition_sched_domains(). | |
1da177e4 | 7476 | */ |
0b2e918a TH |
7477 | static int cpuset_cpu_active(struct notifier_block *nfb, unsigned long action, |
7478 | void *hcpu) | |
e761b772 | 7479 | { |
3a101d05 | 7480 | switch (action & ~CPU_TASKS_FROZEN) { |
e761b772 | 7481 | case CPU_ONLINE: |
6ad4c188 | 7482 | case CPU_DOWN_FAILED: |
3a101d05 | 7483 | cpuset_update_active_cpus(); |
e761b772 | 7484 | return NOTIFY_OK; |
3a101d05 TH |
7485 | default: |
7486 | return NOTIFY_DONE; | |
7487 | } | |
7488 | } | |
e761b772 | 7489 | |
0b2e918a TH |
7490 | static int cpuset_cpu_inactive(struct notifier_block *nfb, unsigned long action, |
7491 | void *hcpu) | |
3a101d05 TH |
7492 | { |
7493 | switch (action & ~CPU_TASKS_FROZEN) { | |
7494 | case CPU_DOWN_PREPARE: | |
7495 | cpuset_update_active_cpus(); | |
7496 | return NOTIFY_OK; | |
e761b772 MK |
7497 | default: |
7498 | return NOTIFY_DONE; | |
7499 | } | |
7500 | } | |
e761b772 MK |
7501 | |
7502 | static int update_runtime(struct notifier_block *nfb, | |
7503 | unsigned long action, void *hcpu) | |
1da177e4 | 7504 | { |
7def2be1 PZ |
7505 | int cpu = (int)(long)hcpu; |
7506 | ||
1da177e4 | 7507 | switch (action) { |
1da177e4 | 7508 | case CPU_DOWN_PREPARE: |
8bb78442 | 7509 | case CPU_DOWN_PREPARE_FROZEN: |
7def2be1 | 7510 | disable_runtime(cpu_rq(cpu)); |
1da177e4 LT |
7511 | return NOTIFY_OK; |
7512 | ||
1da177e4 | 7513 | case CPU_DOWN_FAILED: |
8bb78442 | 7514 | case CPU_DOWN_FAILED_FROZEN: |
1da177e4 | 7515 | case CPU_ONLINE: |
8bb78442 | 7516 | case CPU_ONLINE_FROZEN: |
7def2be1 | 7517 | enable_runtime(cpu_rq(cpu)); |
e761b772 MK |
7518 | return NOTIFY_OK; |
7519 | ||
1da177e4 LT |
7520 | default: |
7521 | return NOTIFY_DONE; | |
7522 | } | |
1da177e4 | 7523 | } |
1da177e4 LT |
7524 | |
7525 | void __init sched_init_smp(void) | |
7526 | { | |
dcc30a35 RR |
7527 | cpumask_var_t non_isolated_cpus; |
7528 | ||
7529 | alloc_cpumask_var(&non_isolated_cpus, GFP_KERNEL); | |
cb5fd13f | 7530 | alloc_cpumask_var(&fallback_doms, GFP_KERNEL); |
5c1e1767 | 7531 | |
434d53b0 MT |
7532 | #if defined(CONFIG_NUMA) |
7533 | sched_group_nodes_bycpu = kzalloc(nr_cpu_ids * sizeof(void **), | |
7534 | GFP_KERNEL); | |
7535 | BUG_ON(sched_group_nodes_bycpu == NULL); | |
7536 | #endif | |
95402b38 | 7537 | get_online_cpus(); |
712555ee | 7538 | mutex_lock(&sched_domains_mutex); |
6ad4c188 | 7539 | arch_init_sched_domains(cpu_active_mask); |
dcc30a35 RR |
7540 | cpumask_andnot(non_isolated_cpus, cpu_possible_mask, cpu_isolated_map); |
7541 | if (cpumask_empty(non_isolated_cpus)) | |
7542 | cpumask_set_cpu(smp_processor_id(), non_isolated_cpus); | |
712555ee | 7543 | mutex_unlock(&sched_domains_mutex); |
95402b38 | 7544 | put_online_cpus(); |
e761b772 | 7545 | |
3a101d05 TH |
7546 | hotcpu_notifier(cpuset_cpu_active, CPU_PRI_CPUSET_ACTIVE); |
7547 | hotcpu_notifier(cpuset_cpu_inactive, CPU_PRI_CPUSET_INACTIVE); | |
e761b772 MK |
7548 | |
7549 | /* RT runtime code needs to handle some hotplug events */ | |
7550 | hotcpu_notifier(update_runtime, 0); | |
7551 | ||
b328ca18 | 7552 | init_hrtick(); |
5c1e1767 NP |
7553 | |
7554 | /* Move init over to a non-isolated CPU */ | |
dcc30a35 | 7555 | if (set_cpus_allowed_ptr(current, non_isolated_cpus) < 0) |
5c1e1767 | 7556 | BUG(); |
19978ca6 | 7557 | sched_init_granularity(); |
dcc30a35 | 7558 | free_cpumask_var(non_isolated_cpus); |
4212823f | 7559 | |
0e3900e6 | 7560 | init_sched_rt_class(); |
1da177e4 LT |
7561 | } |
7562 | #else | |
7563 | void __init sched_init_smp(void) | |
7564 | { | |
19978ca6 | 7565 | sched_init_granularity(); |
1da177e4 LT |
7566 | } |
7567 | #endif /* CONFIG_SMP */ | |
7568 | ||
cd1bb94b AB |
7569 | const_debug unsigned int sysctl_timer_migration = 1; |
7570 | ||
1da177e4 LT |
7571 | int in_sched_functions(unsigned long addr) |
7572 | { | |
1da177e4 LT |
7573 | return in_lock_functions(addr) || |
7574 | (addr >= (unsigned long)__sched_text_start | |
7575 | && addr < (unsigned long)__sched_text_end); | |
7576 | } | |
7577 | ||
a9957449 | 7578 | static void init_cfs_rq(struct cfs_rq *cfs_rq, struct rq *rq) |
dd41f596 IM |
7579 | { |
7580 | cfs_rq->tasks_timeline = RB_ROOT; | |
4a55bd5e | 7581 | INIT_LIST_HEAD(&cfs_rq->tasks); |
dd41f596 IM |
7582 | #ifdef CONFIG_FAIR_GROUP_SCHED |
7583 | cfs_rq->rq = rq; | |
7584 | #endif | |
67e9fb2a | 7585 | cfs_rq->min_vruntime = (u64)(-(1LL << 20)); |
dd41f596 IM |
7586 | } |
7587 | ||
fa85ae24 PZ |
7588 | static void init_rt_rq(struct rt_rq *rt_rq, struct rq *rq) |
7589 | { | |
7590 | struct rt_prio_array *array; | |
7591 | int i; | |
7592 | ||
7593 | array = &rt_rq->active; | |
7594 | for (i = 0; i < MAX_RT_PRIO; i++) { | |
7595 | INIT_LIST_HEAD(array->queue + i); | |
7596 | __clear_bit(i, array->bitmap); | |
7597 | } | |
7598 | /* delimiter for bitsearch: */ | |
7599 | __set_bit(MAX_RT_PRIO, array->bitmap); | |
7600 | ||
052f1dc7 | 7601 | #if defined CONFIG_SMP || defined CONFIG_RT_GROUP_SCHED |
e864c499 | 7602 | rt_rq->highest_prio.curr = MAX_RT_PRIO; |
398a153b | 7603 | #ifdef CONFIG_SMP |
e864c499 | 7604 | rt_rq->highest_prio.next = MAX_RT_PRIO; |
48d5e258 | 7605 | #endif |
48d5e258 | 7606 | #endif |
fa85ae24 PZ |
7607 | #ifdef CONFIG_SMP |
7608 | rt_rq->rt_nr_migratory = 0; | |
fa85ae24 | 7609 | rt_rq->overloaded = 0; |
05fa785c | 7610 | plist_head_init_raw(&rt_rq->pushable_tasks, &rq->lock); |
fa85ae24 PZ |
7611 | #endif |
7612 | ||
7613 | rt_rq->rt_time = 0; | |
7614 | rt_rq->rt_throttled = 0; | |
ac086bc2 | 7615 | rt_rq->rt_runtime = 0; |
0986b11b | 7616 | raw_spin_lock_init(&rt_rq->rt_runtime_lock); |
6f505b16 | 7617 | |
052f1dc7 | 7618 | #ifdef CONFIG_RT_GROUP_SCHED |
23b0fdfc | 7619 | rt_rq->rt_nr_boosted = 0; |
6f505b16 PZ |
7620 | rt_rq->rq = rq; |
7621 | #endif | |
fa85ae24 PZ |
7622 | } |
7623 | ||
6f505b16 | 7624 | #ifdef CONFIG_FAIR_GROUP_SCHED |
ec7dc8ac DG |
7625 | static void init_tg_cfs_entry(struct task_group *tg, struct cfs_rq *cfs_rq, |
7626 | struct sched_entity *se, int cpu, int add, | |
7627 | struct sched_entity *parent) | |
6f505b16 | 7628 | { |
ec7dc8ac | 7629 | struct rq *rq = cpu_rq(cpu); |
6f505b16 PZ |
7630 | tg->cfs_rq[cpu] = cfs_rq; |
7631 | init_cfs_rq(cfs_rq, rq); | |
7632 | cfs_rq->tg = tg; | |
7633 | if (add) | |
7634 | list_add(&cfs_rq->leaf_cfs_rq_list, &rq->leaf_cfs_rq_list); | |
7635 | ||
7636 | tg->se[cpu] = se; | |
354d60c2 DG |
7637 | /* se could be NULL for init_task_group */ |
7638 | if (!se) | |
7639 | return; | |
7640 | ||
ec7dc8ac DG |
7641 | if (!parent) |
7642 | se->cfs_rq = &rq->cfs; | |
7643 | else | |
7644 | se->cfs_rq = parent->my_q; | |
7645 | ||
6f505b16 PZ |
7646 | se->my_q = cfs_rq; |
7647 | se->load.weight = tg->shares; | |
e05510d0 | 7648 | se->load.inv_weight = 0; |
ec7dc8ac | 7649 | se->parent = parent; |
6f505b16 | 7650 | } |
052f1dc7 | 7651 | #endif |
6f505b16 | 7652 | |
052f1dc7 | 7653 | #ifdef CONFIG_RT_GROUP_SCHED |
ec7dc8ac DG |
7654 | static void init_tg_rt_entry(struct task_group *tg, struct rt_rq *rt_rq, |
7655 | struct sched_rt_entity *rt_se, int cpu, int add, | |
7656 | struct sched_rt_entity *parent) | |
6f505b16 | 7657 | { |
ec7dc8ac DG |
7658 | struct rq *rq = cpu_rq(cpu); |
7659 | ||
6f505b16 PZ |
7660 | tg->rt_rq[cpu] = rt_rq; |
7661 | init_rt_rq(rt_rq, rq); | |
7662 | rt_rq->tg = tg; | |
ac086bc2 | 7663 | rt_rq->rt_runtime = tg->rt_bandwidth.rt_runtime; |
6f505b16 PZ |
7664 | if (add) |
7665 | list_add(&rt_rq->leaf_rt_rq_list, &rq->leaf_rt_rq_list); | |
7666 | ||
7667 | tg->rt_se[cpu] = rt_se; | |
354d60c2 DG |
7668 | if (!rt_se) |
7669 | return; | |
7670 | ||
ec7dc8ac DG |
7671 | if (!parent) |
7672 | rt_se->rt_rq = &rq->rt; | |
7673 | else | |
7674 | rt_se->rt_rq = parent->my_q; | |
7675 | ||
6f505b16 | 7676 | rt_se->my_q = rt_rq; |
ec7dc8ac | 7677 | rt_se->parent = parent; |
6f505b16 PZ |
7678 | INIT_LIST_HEAD(&rt_se->run_list); |
7679 | } | |
7680 | #endif | |
7681 | ||
1da177e4 LT |
7682 | void __init sched_init(void) |
7683 | { | |
dd41f596 | 7684 | int i, j; |
434d53b0 MT |
7685 | unsigned long alloc_size = 0, ptr; |
7686 | ||
7687 | #ifdef CONFIG_FAIR_GROUP_SCHED | |
7688 | alloc_size += 2 * nr_cpu_ids * sizeof(void **); | |
7689 | #endif | |
7690 | #ifdef CONFIG_RT_GROUP_SCHED | |
7691 | alloc_size += 2 * nr_cpu_ids * sizeof(void **); | |
eff766a6 | 7692 | #endif |
df7c8e84 | 7693 | #ifdef CONFIG_CPUMASK_OFFSTACK |
8c083f08 | 7694 | alloc_size += num_possible_cpus() * cpumask_size(); |
434d53b0 | 7695 | #endif |
434d53b0 | 7696 | if (alloc_size) { |
36b7b6d4 | 7697 | ptr = (unsigned long)kzalloc(alloc_size, GFP_NOWAIT); |
434d53b0 MT |
7698 | |
7699 | #ifdef CONFIG_FAIR_GROUP_SCHED | |
7700 | init_task_group.se = (struct sched_entity **)ptr; | |
7701 | ptr += nr_cpu_ids * sizeof(void **); | |
7702 | ||
7703 | init_task_group.cfs_rq = (struct cfs_rq **)ptr; | |
7704 | ptr += nr_cpu_ids * sizeof(void **); | |
eff766a6 | 7705 | |
6d6bc0ad | 7706 | #endif /* CONFIG_FAIR_GROUP_SCHED */ |
434d53b0 MT |
7707 | #ifdef CONFIG_RT_GROUP_SCHED |
7708 | init_task_group.rt_se = (struct sched_rt_entity **)ptr; | |
7709 | ptr += nr_cpu_ids * sizeof(void **); | |
7710 | ||
7711 | init_task_group.rt_rq = (struct rt_rq **)ptr; | |
eff766a6 PZ |
7712 | ptr += nr_cpu_ids * sizeof(void **); |
7713 | ||
6d6bc0ad | 7714 | #endif /* CONFIG_RT_GROUP_SCHED */ |
df7c8e84 RR |
7715 | #ifdef CONFIG_CPUMASK_OFFSTACK |
7716 | for_each_possible_cpu(i) { | |
7717 | per_cpu(load_balance_tmpmask, i) = (void *)ptr; | |
7718 | ptr += cpumask_size(); | |
7719 | } | |
7720 | #endif /* CONFIG_CPUMASK_OFFSTACK */ | |
434d53b0 | 7721 | } |
dd41f596 | 7722 | |
57d885fe GH |
7723 | #ifdef CONFIG_SMP |
7724 | init_defrootdomain(); | |
7725 | #endif | |
7726 | ||
d0b27fa7 PZ |
7727 | init_rt_bandwidth(&def_rt_bandwidth, |
7728 | global_rt_period(), global_rt_runtime()); | |
7729 | ||
7730 | #ifdef CONFIG_RT_GROUP_SCHED | |
7731 | init_rt_bandwidth(&init_task_group.rt_bandwidth, | |
7732 | global_rt_period(), global_rt_runtime()); | |
6d6bc0ad | 7733 | #endif /* CONFIG_RT_GROUP_SCHED */ |
d0b27fa7 | 7734 | |
7c941438 | 7735 | #ifdef CONFIG_CGROUP_SCHED |
6f505b16 | 7736 | list_add(&init_task_group.list, &task_groups); |
f473aa5e PZ |
7737 | INIT_LIST_HEAD(&init_task_group.children); |
7738 | ||
7c941438 | 7739 | #endif /* CONFIG_CGROUP_SCHED */ |
6f505b16 | 7740 | |
4a6cc4bd JK |
7741 | #if defined CONFIG_FAIR_GROUP_SCHED && defined CONFIG_SMP |
7742 | update_shares_data = __alloc_percpu(nr_cpu_ids * sizeof(unsigned long), | |
7743 | __alignof__(unsigned long)); | |
7744 | #endif | |
0a945022 | 7745 | for_each_possible_cpu(i) { |
70b97a7f | 7746 | struct rq *rq; |
1da177e4 LT |
7747 | |
7748 | rq = cpu_rq(i); | |
05fa785c | 7749 | raw_spin_lock_init(&rq->lock); |
7897986b | 7750 | rq->nr_running = 0; |
dce48a84 TG |
7751 | rq->calc_load_active = 0; |
7752 | rq->calc_load_update = jiffies + LOAD_FREQ; | |
dd41f596 | 7753 | init_cfs_rq(&rq->cfs, rq); |
6f505b16 | 7754 | init_rt_rq(&rq->rt, rq); |
dd41f596 | 7755 | #ifdef CONFIG_FAIR_GROUP_SCHED |
4cf86d77 | 7756 | init_task_group.shares = init_task_group_load; |
6f505b16 | 7757 | INIT_LIST_HEAD(&rq->leaf_cfs_rq_list); |
354d60c2 DG |
7758 | #ifdef CONFIG_CGROUP_SCHED |
7759 | /* | |
7760 | * How much cpu bandwidth does init_task_group get? | |
7761 | * | |
7762 | * In case of task-groups formed thr' the cgroup filesystem, it | |
7763 | * gets 100% of the cpu resources in the system. This overall | |
7764 | * system cpu resource is divided among the tasks of | |
7765 | * init_task_group and its child task-groups in a fair manner, | |
7766 | * based on each entity's (task or task-group's) weight | |
7767 | * (se->load.weight). | |
7768 | * | |
7769 | * In other words, if init_task_group has 10 tasks of weight | |
7770 | * 1024) and two child groups A0 and A1 (of weight 1024 each), | |
7771 | * then A0's share of the cpu resource is: | |
7772 | * | |
0d905bca | 7773 | * A0's bandwidth = 1024 / (10*1024 + 1024 + 1024) = 8.33% |
354d60c2 DG |
7774 | * |
7775 | * We achieve this by letting init_task_group's tasks sit | |
7776 | * directly in rq->cfs (i.e init_task_group->se[] = NULL). | |
7777 | */ | |
ec7dc8ac | 7778 | init_tg_cfs_entry(&init_task_group, &rq->cfs, NULL, i, 1, NULL); |
052f1dc7 | 7779 | #endif |
354d60c2 DG |
7780 | #endif /* CONFIG_FAIR_GROUP_SCHED */ |
7781 | ||
7782 | rq->rt.rt_runtime = def_rt_bandwidth.rt_runtime; | |
052f1dc7 | 7783 | #ifdef CONFIG_RT_GROUP_SCHED |
6f505b16 | 7784 | INIT_LIST_HEAD(&rq->leaf_rt_rq_list); |
354d60c2 | 7785 | #ifdef CONFIG_CGROUP_SCHED |
ec7dc8ac | 7786 | init_tg_rt_entry(&init_task_group, &rq->rt, NULL, i, 1, NULL); |
354d60c2 | 7787 | #endif |
dd41f596 | 7788 | #endif |
1da177e4 | 7789 | |
dd41f596 IM |
7790 | for (j = 0; j < CPU_LOAD_IDX_MAX; j++) |
7791 | rq->cpu_load[j] = 0; | |
fdf3e95d VP |
7792 | |
7793 | rq->last_load_update_tick = jiffies; | |
7794 | ||
1da177e4 | 7795 | #ifdef CONFIG_SMP |
41c7ce9a | 7796 | rq->sd = NULL; |
57d885fe | 7797 | rq->rd = NULL; |
e51fd5e2 | 7798 | rq->cpu_power = SCHED_LOAD_SCALE; |
3f029d3c | 7799 | rq->post_schedule = 0; |
1da177e4 | 7800 | rq->active_balance = 0; |
dd41f596 | 7801 | rq->next_balance = jiffies; |
1da177e4 | 7802 | rq->push_cpu = 0; |
0a2966b4 | 7803 | rq->cpu = i; |
1f11eb6a | 7804 | rq->online = 0; |
eae0c9df MG |
7805 | rq->idle_stamp = 0; |
7806 | rq->avg_idle = 2*sysctl_sched_migration_cost; | |
dc938520 | 7807 | rq_attach_root(rq, &def_root_domain); |
83cd4fe2 VP |
7808 | #ifdef CONFIG_NO_HZ |
7809 | rq->nohz_balance_kick = 0; | |
7810 | init_sched_softirq_csd(&per_cpu(remote_sched_softirq_cb, i)); | |
7811 | #endif | |
1da177e4 | 7812 | #endif |
8f4d37ec | 7813 | init_rq_hrtick(rq); |
1da177e4 | 7814 | atomic_set(&rq->nr_iowait, 0); |
1da177e4 LT |
7815 | } |
7816 | ||
2dd73a4f | 7817 | set_load_weight(&init_task); |
b50f60ce | 7818 | |
e107be36 AK |
7819 | #ifdef CONFIG_PREEMPT_NOTIFIERS |
7820 | INIT_HLIST_HEAD(&init_task.preempt_notifiers); | |
7821 | #endif | |
7822 | ||
c9819f45 | 7823 | #ifdef CONFIG_SMP |
962cf36c | 7824 | open_softirq(SCHED_SOFTIRQ, run_rebalance_domains); |
c9819f45 CL |
7825 | #endif |
7826 | ||
b50f60ce | 7827 | #ifdef CONFIG_RT_MUTEXES |
1d615482 | 7828 | plist_head_init_raw(&init_task.pi_waiters, &init_task.pi_lock); |
b50f60ce HC |
7829 | #endif |
7830 | ||
1da177e4 LT |
7831 | /* |
7832 | * The boot idle thread does lazy MMU switching as well: | |
7833 | */ | |
7834 | atomic_inc(&init_mm.mm_count); | |
7835 | enter_lazy_tlb(&init_mm, current); | |
7836 | ||
7837 | /* | |
7838 | * Make us the idle thread. Technically, schedule() should not be | |
7839 | * called from this thread, however somewhere below it might be, | |
7840 | * but because we are the idle thread, we just pick up running again | |
7841 | * when this runqueue becomes "idle". | |
7842 | */ | |
7843 | init_idle(current, smp_processor_id()); | |
dce48a84 TG |
7844 | |
7845 | calc_load_update = jiffies + LOAD_FREQ; | |
7846 | ||
dd41f596 IM |
7847 | /* |
7848 | * During early bootup we pretend to be a normal task: | |
7849 | */ | |
7850 | current->sched_class = &fair_sched_class; | |
6892b75e | 7851 | |
6a7b3dc3 | 7852 | /* Allocate the nohz_cpu_mask if CONFIG_CPUMASK_OFFSTACK */ |
49557e62 | 7853 | zalloc_cpumask_var(&nohz_cpu_mask, GFP_NOWAIT); |
bf4d83f6 | 7854 | #ifdef CONFIG_SMP |
7d1e6a9b | 7855 | #ifdef CONFIG_NO_HZ |
83cd4fe2 VP |
7856 | zalloc_cpumask_var(&nohz.idle_cpus_mask, GFP_NOWAIT); |
7857 | alloc_cpumask_var(&nohz.grp_idle_mask, GFP_NOWAIT); | |
7858 | atomic_set(&nohz.load_balancer, nr_cpu_ids); | |
7859 | atomic_set(&nohz.first_pick_cpu, nr_cpu_ids); | |
7860 | atomic_set(&nohz.second_pick_cpu, nr_cpu_ids); | |
7d1e6a9b | 7861 | #endif |
bdddd296 RR |
7862 | /* May be allocated at isolcpus cmdline parse time */ |
7863 | if (cpu_isolated_map == NULL) | |
7864 | zalloc_cpumask_var(&cpu_isolated_map, GFP_NOWAIT); | |
bf4d83f6 | 7865 | #endif /* SMP */ |
6a7b3dc3 | 7866 | |
cdd6c482 | 7867 | perf_event_init(); |
0d905bca | 7868 | |
6892b75e | 7869 | scheduler_running = 1; |
1da177e4 LT |
7870 | } |
7871 | ||
7872 | #ifdef CONFIG_DEBUG_SPINLOCK_SLEEP | |
e4aafea2 FW |
7873 | static inline int preempt_count_equals(int preempt_offset) |
7874 | { | |
234da7bc | 7875 | int nested = (preempt_count() & ~PREEMPT_ACTIVE) + rcu_preempt_depth(); |
e4aafea2 FW |
7876 | |
7877 | return (nested == PREEMPT_INATOMIC_BASE + preempt_offset); | |
7878 | } | |
7879 | ||
d894837f | 7880 | void __might_sleep(const char *file, int line, int preempt_offset) |
1da177e4 | 7881 | { |
48f24c4d | 7882 | #ifdef in_atomic |
1da177e4 LT |
7883 | static unsigned long prev_jiffy; /* ratelimiting */ |
7884 | ||
e4aafea2 FW |
7885 | if ((preempt_count_equals(preempt_offset) && !irqs_disabled()) || |
7886 | system_state != SYSTEM_RUNNING || oops_in_progress) | |
aef745fc IM |
7887 | return; |
7888 | if (time_before(jiffies, prev_jiffy + HZ) && prev_jiffy) | |
7889 | return; | |
7890 | prev_jiffy = jiffies; | |
7891 | ||
3df0fc5b PZ |
7892 | printk(KERN_ERR |
7893 | "BUG: sleeping function called from invalid context at %s:%d\n", | |
7894 | file, line); | |
7895 | printk(KERN_ERR | |
7896 | "in_atomic(): %d, irqs_disabled(): %d, pid: %d, name: %s\n", | |
7897 | in_atomic(), irqs_disabled(), | |
7898 | current->pid, current->comm); | |
aef745fc IM |
7899 | |
7900 | debug_show_held_locks(current); | |
7901 | if (irqs_disabled()) | |
7902 | print_irqtrace_events(current); | |
7903 | dump_stack(); | |
1da177e4 LT |
7904 | #endif |
7905 | } | |
7906 | EXPORT_SYMBOL(__might_sleep); | |
7907 | #endif | |
7908 | ||
7909 | #ifdef CONFIG_MAGIC_SYSRQ | |
3a5e4dc1 AK |
7910 | static void normalize_task(struct rq *rq, struct task_struct *p) |
7911 | { | |
7912 | int on_rq; | |
3e51f33f | 7913 | |
3a5e4dc1 AK |
7914 | on_rq = p->se.on_rq; |
7915 | if (on_rq) | |
7916 | deactivate_task(rq, p, 0); | |
7917 | __setscheduler(rq, p, SCHED_NORMAL, 0); | |
7918 | if (on_rq) { | |
7919 | activate_task(rq, p, 0); | |
7920 | resched_task(rq->curr); | |
7921 | } | |
7922 | } | |
7923 | ||
1da177e4 LT |
7924 | void normalize_rt_tasks(void) |
7925 | { | |
a0f98a1c | 7926 | struct task_struct *g, *p; |
1da177e4 | 7927 | unsigned long flags; |
70b97a7f | 7928 | struct rq *rq; |
1da177e4 | 7929 | |
4cf5d77a | 7930 | read_lock_irqsave(&tasklist_lock, flags); |
a0f98a1c | 7931 | do_each_thread(g, p) { |
178be793 IM |
7932 | /* |
7933 | * Only normalize user tasks: | |
7934 | */ | |
7935 | if (!p->mm) | |
7936 | continue; | |
7937 | ||
6cfb0d5d | 7938 | p->se.exec_start = 0; |
6cfb0d5d | 7939 | #ifdef CONFIG_SCHEDSTATS |
41acab88 LDM |
7940 | p->se.statistics.wait_start = 0; |
7941 | p->se.statistics.sleep_start = 0; | |
7942 | p->se.statistics.block_start = 0; | |
6cfb0d5d | 7943 | #endif |
dd41f596 IM |
7944 | |
7945 | if (!rt_task(p)) { | |
7946 | /* | |
7947 | * Renice negative nice level userspace | |
7948 | * tasks back to 0: | |
7949 | */ | |
7950 | if (TASK_NICE(p) < 0 && p->mm) | |
7951 | set_user_nice(p, 0); | |
1da177e4 | 7952 | continue; |
dd41f596 | 7953 | } |
1da177e4 | 7954 | |
1d615482 | 7955 | raw_spin_lock(&p->pi_lock); |
b29739f9 | 7956 | rq = __task_rq_lock(p); |
1da177e4 | 7957 | |
178be793 | 7958 | normalize_task(rq, p); |
3a5e4dc1 | 7959 | |
b29739f9 | 7960 | __task_rq_unlock(rq); |
1d615482 | 7961 | raw_spin_unlock(&p->pi_lock); |
a0f98a1c IM |
7962 | } while_each_thread(g, p); |
7963 | ||
4cf5d77a | 7964 | read_unlock_irqrestore(&tasklist_lock, flags); |
1da177e4 LT |
7965 | } |
7966 | ||
7967 | #endif /* CONFIG_MAGIC_SYSRQ */ | |
1df5c10a | 7968 | |
67fc4e0c | 7969 | #if defined(CONFIG_IA64) || defined(CONFIG_KGDB_KDB) |
1df5c10a | 7970 | /* |
67fc4e0c | 7971 | * These functions are only useful for the IA64 MCA handling, or kdb. |
1df5c10a LT |
7972 | * |
7973 | * They can only be called when the whole system has been | |
7974 | * stopped - every CPU needs to be quiescent, and no scheduling | |
7975 | * activity can take place. Using them for anything else would | |
7976 | * be a serious bug, and as a result, they aren't even visible | |
7977 | * under any other configuration. | |
7978 | */ | |
7979 | ||
7980 | /** | |
7981 | * curr_task - return the current task for a given cpu. | |
7982 | * @cpu: the processor in question. | |
7983 | * | |
7984 | * ONLY VALID WHEN THE WHOLE SYSTEM IS STOPPED! | |
7985 | */ | |
36c8b586 | 7986 | struct task_struct *curr_task(int cpu) |
1df5c10a LT |
7987 | { |
7988 | return cpu_curr(cpu); | |
7989 | } | |
7990 | ||
67fc4e0c JW |
7991 | #endif /* defined(CONFIG_IA64) || defined(CONFIG_KGDB_KDB) */ |
7992 | ||
7993 | #ifdef CONFIG_IA64 | |
1df5c10a LT |
7994 | /** |
7995 | * set_curr_task - set the current task for a given cpu. | |
7996 | * @cpu: the processor in question. | |
7997 | * @p: the task pointer to set. | |
7998 | * | |
7999 | * Description: This function must only be used when non-maskable interrupts | |
41a2d6cf IM |
8000 | * are serviced on a separate stack. It allows the architecture to switch the |
8001 | * notion of the current task on a cpu in a non-blocking manner. This function | |
1df5c10a LT |
8002 | * must be called with all CPU's synchronized, and interrupts disabled, the |
8003 | * and caller must save the original value of the current task (see | |
8004 | * curr_task() above) and restore that value before reenabling interrupts and | |
8005 | * re-starting the system. | |
8006 | * | |
8007 | * ONLY VALID WHEN THE WHOLE SYSTEM IS STOPPED! | |
8008 | */ | |
36c8b586 | 8009 | void set_curr_task(int cpu, struct task_struct *p) |
1df5c10a LT |
8010 | { |
8011 | cpu_curr(cpu) = p; | |
8012 | } | |
8013 | ||
8014 | #endif | |
29f59db3 | 8015 | |
bccbe08a PZ |
8016 | #ifdef CONFIG_FAIR_GROUP_SCHED |
8017 | static void free_fair_sched_group(struct task_group *tg) | |
6f505b16 PZ |
8018 | { |
8019 | int i; | |
8020 | ||
8021 | for_each_possible_cpu(i) { | |
8022 | if (tg->cfs_rq) | |
8023 | kfree(tg->cfs_rq[i]); | |
8024 | if (tg->se) | |
8025 | kfree(tg->se[i]); | |
6f505b16 PZ |
8026 | } |
8027 | ||
8028 | kfree(tg->cfs_rq); | |
8029 | kfree(tg->se); | |
6f505b16 PZ |
8030 | } |
8031 | ||
ec7dc8ac DG |
8032 | static |
8033 | int alloc_fair_sched_group(struct task_group *tg, struct task_group *parent) | |
29f59db3 | 8034 | { |
29f59db3 | 8035 | struct cfs_rq *cfs_rq; |
eab17229 | 8036 | struct sched_entity *se; |
9b5b7751 | 8037 | struct rq *rq; |
29f59db3 SV |
8038 | int i; |
8039 | ||
434d53b0 | 8040 | tg->cfs_rq = kzalloc(sizeof(cfs_rq) * nr_cpu_ids, GFP_KERNEL); |
29f59db3 SV |
8041 | if (!tg->cfs_rq) |
8042 | goto err; | |
434d53b0 | 8043 | tg->se = kzalloc(sizeof(se) * nr_cpu_ids, GFP_KERNEL); |
29f59db3 SV |
8044 | if (!tg->se) |
8045 | goto err; | |
052f1dc7 PZ |
8046 | |
8047 | tg->shares = NICE_0_LOAD; | |
29f59db3 SV |
8048 | |
8049 | for_each_possible_cpu(i) { | |
9b5b7751 | 8050 | rq = cpu_rq(i); |
29f59db3 | 8051 | |
eab17229 LZ |
8052 | cfs_rq = kzalloc_node(sizeof(struct cfs_rq), |
8053 | GFP_KERNEL, cpu_to_node(i)); | |
29f59db3 SV |
8054 | if (!cfs_rq) |
8055 | goto err; | |
8056 | ||
eab17229 LZ |
8057 | se = kzalloc_node(sizeof(struct sched_entity), |
8058 | GFP_KERNEL, cpu_to_node(i)); | |
29f59db3 | 8059 | if (!se) |
dfc12eb2 | 8060 | goto err_free_rq; |
29f59db3 | 8061 | |
eab17229 | 8062 | init_tg_cfs_entry(tg, cfs_rq, se, i, 0, parent->se[i]); |
bccbe08a PZ |
8063 | } |
8064 | ||
8065 | return 1; | |
8066 | ||
dfc12eb2 PC |
8067 | err_free_rq: |
8068 | kfree(cfs_rq); | |
bccbe08a PZ |
8069 | err: |
8070 | return 0; | |
8071 | } | |
8072 | ||
8073 | static inline void register_fair_sched_group(struct task_group *tg, int cpu) | |
8074 | { | |
8075 | list_add_rcu(&tg->cfs_rq[cpu]->leaf_cfs_rq_list, | |
8076 | &cpu_rq(cpu)->leaf_cfs_rq_list); | |
8077 | } | |
8078 | ||
8079 | static inline void unregister_fair_sched_group(struct task_group *tg, int cpu) | |
8080 | { | |
8081 | list_del_rcu(&tg->cfs_rq[cpu]->leaf_cfs_rq_list); | |
8082 | } | |
6d6bc0ad | 8083 | #else /* !CONFG_FAIR_GROUP_SCHED */ |
bccbe08a PZ |
8084 | static inline void free_fair_sched_group(struct task_group *tg) |
8085 | { | |
8086 | } | |
8087 | ||
ec7dc8ac DG |
8088 | static inline |
8089 | int alloc_fair_sched_group(struct task_group *tg, struct task_group *parent) | |
bccbe08a PZ |
8090 | { |
8091 | return 1; | |
8092 | } | |
8093 | ||
8094 | static inline void register_fair_sched_group(struct task_group *tg, int cpu) | |
8095 | { | |
8096 | } | |
8097 | ||
8098 | static inline void unregister_fair_sched_group(struct task_group *tg, int cpu) | |
8099 | { | |
8100 | } | |
6d6bc0ad | 8101 | #endif /* CONFIG_FAIR_GROUP_SCHED */ |
052f1dc7 PZ |
8102 | |
8103 | #ifdef CONFIG_RT_GROUP_SCHED | |
bccbe08a PZ |
8104 | static void free_rt_sched_group(struct task_group *tg) |
8105 | { | |
8106 | int i; | |
8107 | ||
d0b27fa7 PZ |
8108 | destroy_rt_bandwidth(&tg->rt_bandwidth); |
8109 | ||
bccbe08a PZ |
8110 | for_each_possible_cpu(i) { |
8111 | if (tg->rt_rq) | |
8112 | kfree(tg->rt_rq[i]); | |
8113 | if (tg->rt_se) | |
8114 | kfree(tg->rt_se[i]); | |
8115 | } | |
8116 | ||
8117 | kfree(tg->rt_rq); | |
8118 | kfree(tg->rt_se); | |
8119 | } | |
8120 | ||
ec7dc8ac DG |
8121 | static |
8122 | int alloc_rt_sched_group(struct task_group *tg, struct task_group *parent) | |
bccbe08a PZ |
8123 | { |
8124 | struct rt_rq *rt_rq; | |
eab17229 | 8125 | struct sched_rt_entity *rt_se; |
bccbe08a PZ |
8126 | struct rq *rq; |
8127 | int i; | |
8128 | ||
434d53b0 | 8129 | tg->rt_rq = kzalloc(sizeof(rt_rq) * nr_cpu_ids, GFP_KERNEL); |
bccbe08a PZ |
8130 | if (!tg->rt_rq) |
8131 | goto err; | |
434d53b0 | 8132 | tg->rt_se = kzalloc(sizeof(rt_se) * nr_cpu_ids, GFP_KERNEL); |
bccbe08a PZ |
8133 | if (!tg->rt_se) |
8134 | goto err; | |
8135 | ||
d0b27fa7 PZ |
8136 | init_rt_bandwidth(&tg->rt_bandwidth, |
8137 | ktime_to_ns(def_rt_bandwidth.rt_period), 0); | |
bccbe08a PZ |
8138 | |
8139 | for_each_possible_cpu(i) { | |
8140 | rq = cpu_rq(i); | |
8141 | ||
eab17229 LZ |
8142 | rt_rq = kzalloc_node(sizeof(struct rt_rq), |
8143 | GFP_KERNEL, cpu_to_node(i)); | |
6f505b16 PZ |
8144 | if (!rt_rq) |
8145 | goto err; | |
29f59db3 | 8146 | |
eab17229 LZ |
8147 | rt_se = kzalloc_node(sizeof(struct sched_rt_entity), |
8148 | GFP_KERNEL, cpu_to_node(i)); | |
6f505b16 | 8149 | if (!rt_se) |
dfc12eb2 | 8150 | goto err_free_rq; |
29f59db3 | 8151 | |
eab17229 | 8152 | init_tg_rt_entry(tg, rt_rq, rt_se, i, 0, parent->rt_se[i]); |
29f59db3 SV |
8153 | } |
8154 | ||
bccbe08a PZ |
8155 | return 1; |
8156 | ||
dfc12eb2 PC |
8157 | err_free_rq: |
8158 | kfree(rt_rq); | |
bccbe08a PZ |
8159 | err: |
8160 | return 0; | |
8161 | } | |
8162 | ||
8163 | static inline void register_rt_sched_group(struct task_group *tg, int cpu) | |
8164 | { | |
8165 | list_add_rcu(&tg->rt_rq[cpu]->leaf_rt_rq_list, | |
8166 | &cpu_rq(cpu)->leaf_rt_rq_list); | |
8167 | } | |
8168 | ||
8169 | static inline void unregister_rt_sched_group(struct task_group *tg, int cpu) | |
8170 | { | |
8171 | list_del_rcu(&tg->rt_rq[cpu]->leaf_rt_rq_list); | |
8172 | } | |
6d6bc0ad | 8173 | #else /* !CONFIG_RT_GROUP_SCHED */ |
bccbe08a PZ |
8174 | static inline void free_rt_sched_group(struct task_group *tg) |
8175 | { | |
8176 | } | |
8177 | ||
ec7dc8ac DG |
8178 | static inline |
8179 | int alloc_rt_sched_group(struct task_group *tg, struct task_group *parent) | |
bccbe08a PZ |
8180 | { |
8181 | return 1; | |
8182 | } | |
8183 | ||
8184 | static inline void register_rt_sched_group(struct task_group *tg, int cpu) | |
8185 | { | |
8186 | } | |
8187 | ||
8188 | static inline void unregister_rt_sched_group(struct task_group *tg, int cpu) | |
8189 | { | |
8190 | } | |
6d6bc0ad | 8191 | #endif /* CONFIG_RT_GROUP_SCHED */ |
bccbe08a | 8192 | |
7c941438 | 8193 | #ifdef CONFIG_CGROUP_SCHED |
bccbe08a PZ |
8194 | static void free_sched_group(struct task_group *tg) |
8195 | { | |
8196 | free_fair_sched_group(tg); | |
8197 | free_rt_sched_group(tg); | |
8198 | kfree(tg); | |
8199 | } | |
8200 | ||
8201 | /* allocate runqueue etc for a new task group */ | |
ec7dc8ac | 8202 | struct task_group *sched_create_group(struct task_group *parent) |
bccbe08a PZ |
8203 | { |
8204 | struct task_group *tg; | |
8205 | unsigned long flags; | |
8206 | int i; | |
8207 | ||
8208 | tg = kzalloc(sizeof(*tg), GFP_KERNEL); | |
8209 | if (!tg) | |
8210 | return ERR_PTR(-ENOMEM); | |
8211 | ||
ec7dc8ac | 8212 | if (!alloc_fair_sched_group(tg, parent)) |
bccbe08a PZ |
8213 | goto err; |
8214 | ||
ec7dc8ac | 8215 | if (!alloc_rt_sched_group(tg, parent)) |
bccbe08a PZ |
8216 | goto err; |
8217 | ||
8ed36996 | 8218 | spin_lock_irqsave(&task_group_lock, flags); |
9b5b7751 | 8219 | for_each_possible_cpu(i) { |
bccbe08a PZ |
8220 | register_fair_sched_group(tg, i); |
8221 | register_rt_sched_group(tg, i); | |
9b5b7751 | 8222 | } |
6f505b16 | 8223 | list_add_rcu(&tg->list, &task_groups); |
f473aa5e PZ |
8224 | |
8225 | WARN_ON(!parent); /* root should already exist */ | |
8226 | ||
8227 | tg->parent = parent; | |
f473aa5e | 8228 | INIT_LIST_HEAD(&tg->children); |
09f2724a | 8229 | list_add_rcu(&tg->siblings, &parent->children); |
8ed36996 | 8230 | spin_unlock_irqrestore(&task_group_lock, flags); |
29f59db3 | 8231 | |
9b5b7751 | 8232 | return tg; |
29f59db3 SV |
8233 | |
8234 | err: | |
6f505b16 | 8235 | free_sched_group(tg); |
29f59db3 SV |
8236 | return ERR_PTR(-ENOMEM); |
8237 | } | |
8238 | ||
9b5b7751 | 8239 | /* rcu callback to free various structures associated with a task group */ |
6f505b16 | 8240 | static void free_sched_group_rcu(struct rcu_head *rhp) |
29f59db3 | 8241 | { |
29f59db3 | 8242 | /* now it should be safe to free those cfs_rqs */ |
6f505b16 | 8243 | free_sched_group(container_of(rhp, struct task_group, rcu)); |
29f59db3 SV |
8244 | } |
8245 | ||
9b5b7751 | 8246 | /* Destroy runqueue etc associated with a task group */ |
4cf86d77 | 8247 | void sched_destroy_group(struct task_group *tg) |
29f59db3 | 8248 | { |
8ed36996 | 8249 | unsigned long flags; |
9b5b7751 | 8250 | int i; |
29f59db3 | 8251 | |
8ed36996 | 8252 | spin_lock_irqsave(&task_group_lock, flags); |
9b5b7751 | 8253 | for_each_possible_cpu(i) { |
bccbe08a PZ |
8254 | unregister_fair_sched_group(tg, i); |
8255 | unregister_rt_sched_group(tg, i); | |
9b5b7751 | 8256 | } |
6f505b16 | 8257 | list_del_rcu(&tg->list); |
f473aa5e | 8258 | list_del_rcu(&tg->siblings); |
8ed36996 | 8259 | spin_unlock_irqrestore(&task_group_lock, flags); |
9b5b7751 | 8260 | |
9b5b7751 | 8261 | /* wait for possible concurrent references to cfs_rqs complete */ |
6f505b16 | 8262 | call_rcu(&tg->rcu, free_sched_group_rcu); |
29f59db3 SV |
8263 | } |
8264 | ||
9b5b7751 | 8265 | /* change task's runqueue when it moves between groups. |
3a252015 IM |
8266 | * The caller of this function should have put the task in its new group |
8267 | * by now. This function just updates tsk->se.cfs_rq and tsk->se.parent to | |
8268 | * reflect its new group. | |
9b5b7751 SV |
8269 | */ |
8270 | void sched_move_task(struct task_struct *tsk) | |
29f59db3 SV |
8271 | { |
8272 | int on_rq, running; | |
8273 | unsigned long flags; | |
8274 | struct rq *rq; | |
8275 | ||
8276 | rq = task_rq_lock(tsk, &flags); | |
8277 | ||
051a1d1a | 8278 | running = task_current(rq, tsk); |
29f59db3 SV |
8279 | on_rq = tsk->se.on_rq; |
8280 | ||
0e1f3483 | 8281 | if (on_rq) |
29f59db3 | 8282 | dequeue_task(rq, tsk, 0); |
0e1f3483 HS |
8283 | if (unlikely(running)) |
8284 | tsk->sched_class->put_prev_task(rq, tsk); | |
29f59db3 | 8285 | |
6f505b16 | 8286 | set_task_rq(tsk, task_cpu(tsk)); |
29f59db3 | 8287 | |
810b3817 PZ |
8288 | #ifdef CONFIG_FAIR_GROUP_SCHED |
8289 | if (tsk->sched_class->moved_group) | |
88ec22d3 | 8290 | tsk->sched_class->moved_group(tsk, on_rq); |
810b3817 PZ |
8291 | #endif |
8292 | ||
0e1f3483 HS |
8293 | if (unlikely(running)) |
8294 | tsk->sched_class->set_curr_task(rq); | |
8295 | if (on_rq) | |
371fd7e7 | 8296 | enqueue_task(rq, tsk, 0); |
29f59db3 | 8297 | |
29f59db3 SV |
8298 | task_rq_unlock(rq, &flags); |
8299 | } | |
7c941438 | 8300 | #endif /* CONFIG_CGROUP_SCHED */ |
29f59db3 | 8301 | |
052f1dc7 | 8302 | #ifdef CONFIG_FAIR_GROUP_SCHED |
c09595f6 | 8303 | static void __set_se_shares(struct sched_entity *se, unsigned long shares) |
29f59db3 SV |
8304 | { |
8305 | struct cfs_rq *cfs_rq = se->cfs_rq; | |
29f59db3 SV |
8306 | int on_rq; |
8307 | ||
29f59db3 | 8308 | on_rq = se->on_rq; |
62fb1851 | 8309 | if (on_rq) |
29f59db3 SV |
8310 | dequeue_entity(cfs_rq, se, 0); |
8311 | ||
8312 | se->load.weight = shares; | |
e05510d0 | 8313 | se->load.inv_weight = 0; |
29f59db3 | 8314 | |
62fb1851 | 8315 | if (on_rq) |
29f59db3 | 8316 | enqueue_entity(cfs_rq, se, 0); |
c09595f6 | 8317 | } |
62fb1851 | 8318 | |
c09595f6 PZ |
8319 | static void set_se_shares(struct sched_entity *se, unsigned long shares) |
8320 | { | |
8321 | struct cfs_rq *cfs_rq = se->cfs_rq; | |
8322 | struct rq *rq = cfs_rq->rq; | |
8323 | unsigned long flags; | |
8324 | ||
05fa785c | 8325 | raw_spin_lock_irqsave(&rq->lock, flags); |
c09595f6 | 8326 | __set_se_shares(se, shares); |
05fa785c | 8327 | raw_spin_unlock_irqrestore(&rq->lock, flags); |
29f59db3 SV |
8328 | } |
8329 | ||
8ed36996 PZ |
8330 | static DEFINE_MUTEX(shares_mutex); |
8331 | ||
4cf86d77 | 8332 | int sched_group_set_shares(struct task_group *tg, unsigned long shares) |
29f59db3 SV |
8333 | { |
8334 | int i; | |
8ed36996 | 8335 | unsigned long flags; |
c61935fd | 8336 | |
ec7dc8ac DG |
8337 | /* |
8338 | * We can't change the weight of the root cgroup. | |
8339 | */ | |
8340 | if (!tg->se[0]) | |
8341 | return -EINVAL; | |
8342 | ||
18d95a28 PZ |
8343 | if (shares < MIN_SHARES) |
8344 | shares = MIN_SHARES; | |
cb4ad1ff MX |
8345 | else if (shares > MAX_SHARES) |
8346 | shares = MAX_SHARES; | |
62fb1851 | 8347 | |
8ed36996 | 8348 | mutex_lock(&shares_mutex); |
9b5b7751 | 8349 | if (tg->shares == shares) |
5cb350ba | 8350 | goto done; |
29f59db3 | 8351 | |
8ed36996 | 8352 | spin_lock_irqsave(&task_group_lock, flags); |
bccbe08a PZ |
8353 | for_each_possible_cpu(i) |
8354 | unregister_fair_sched_group(tg, i); | |
f473aa5e | 8355 | list_del_rcu(&tg->siblings); |
8ed36996 | 8356 | spin_unlock_irqrestore(&task_group_lock, flags); |
6b2d7700 SV |
8357 | |
8358 | /* wait for any ongoing reference to this group to finish */ | |
8359 | synchronize_sched(); | |
8360 | ||
8361 | /* | |
8362 | * Now we are free to modify the group's share on each cpu | |
8363 | * w/o tripping rebalance_share or load_balance_fair. | |
8364 | */ | |
9b5b7751 | 8365 | tg->shares = shares; |
c09595f6 PZ |
8366 | for_each_possible_cpu(i) { |
8367 | /* | |
8368 | * force a rebalance | |
8369 | */ | |
8370 | cfs_rq_set_shares(tg->cfs_rq[i], 0); | |
cb4ad1ff | 8371 | set_se_shares(tg->se[i], shares); |
c09595f6 | 8372 | } |
29f59db3 | 8373 | |
6b2d7700 SV |
8374 | /* |
8375 | * Enable load balance activity on this group, by inserting it back on | |
8376 | * each cpu's rq->leaf_cfs_rq_list. | |
8377 | */ | |
8ed36996 | 8378 | spin_lock_irqsave(&task_group_lock, flags); |
bccbe08a PZ |
8379 | for_each_possible_cpu(i) |
8380 | register_fair_sched_group(tg, i); | |
f473aa5e | 8381 | list_add_rcu(&tg->siblings, &tg->parent->children); |
8ed36996 | 8382 | spin_unlock_irqrestore(&task_group_lock, flags); |
5cb350ba | 8383 | done: |
8ed36996 | 8384 | mutex_unlock(&shares_mutex); |
9b5b7751 | 8385 | return 0; |
29f59db3 SV |
8386 | } |
8387 | ||
5cb350ba DG |
8388 | unsigned long sched_group_shares(struct task_group *tg) |
8389 | { | |
8390 | return tg->shares; | |
8391 | } | |
052f1dc7 | 8392 | #endif |
5cb350ba | 8393 | |
052f1dc7 | 8394 | #ifdef CONFIG_RT_GROUP_SCHED |
6f505b16 | 8395 | /* |
9f0c1e56 | 8396 | * Ensure that the real time constraints are schedulable. |
6f505b16 | 8397 | */ |
9f0c1e56 PZ |
8398 | static DEFINE_MUTEX(rt_constraints_mutex); |
8399 | ||
8400 | static unsigned long to_ratio(u64 period, u64 runtime) | |
8401 | { | |
8402 | if (runtime == RUNTIME_INF) | |
9a7e0b18 | 8403 | return 1ULL << 20; |
9f0c1e56 | 8404 | |
9a7e0b18 | 8405 | return div64_u64(runtime << 20, period); |
9f0c1e56 PZ |
8406 | } |
8407 | ||
9a7e0b18 PZ |
8408 | /* Must be called with tasklist_lock held */ |
8409 | static inline int tg_has_rt_tasks(struct task_group *tg) | |
b40b2e8e | 8410 | { |
9a7e0b18 | 8411 | struct task_struct *g, *p; |
b40b2e8e | 8412 | |
9a7e0b18 PZ |
8413 | do_each_thread(g, p) { |
8414 | if (rt_task(p) && rt_rq_of_se(&p->rt)->tg == tg) | |
8415 | return 1; | |
8416 | } while_each_thread(g, p); | |
b40b2e8e | 8417 | |
9a7e0b18 PZ |
8418 | return 0; |
8419 | } | |
b40b2e8e | 8420 | |
9a7e0b18 PZ |
8421 | struct rt_schedulable_data { |
8422 | struct task_group *tg; | |
8423 | u64 rt_period; | |
8424 | u64 rt_runtime; | |
8425 | }; | |
b40b2e8e | 8426 | |
9a7e0b18 PZ |
8427 | static int tg_schedulable(struct task_group *tg, void *data) |
8428 | { | |
8429 | struct rt_schedulable_data *d = data; | |
8430 | struct task_group *child; | |
8431 | unsigned long total, sum = 0; | |
8432 | u64 period, runtime; | |
b40b2e8e | 8433 | |
9a7e0b18 PZ |
8434 | period = ktime_to_ns(tg->rt_bandwidth.rt_period); |
8435 | runtime = tg->rt_bandwidth.rt_runtime; | |
b40b2e8e | 8436 | |
9a7e0b18 PZ |
8437 | if (tg == d->tg) { |
8438 | period = d->rt_period; | |
8439 | runtime = d->rt_runtime; | |
b40b2e8e | 8440 | } |
b40b2e8e | 8441 | |
4653f803 PZ |
8442 | /* |
8443 | * Cannot have more runtime than the period. | |
8444 | */ | |
8445 | if (runtime > period && runtime != RUNTIME_INF) | |
8446 | return -EINVAL; | |
6f505b16 | 8447 | |
4653f803 PZ |
8448 | /* |
8449 | * Ensure we don't starve existing RT tasks. | |
8450 | */ | |
9a7e0b18 PZ |
8451 | if (rt_bandwidth_enabled() && !runtime && tg_has_rt_tasks(tg)) |
8452 | return -EBUSY; | |
6f505b16 | 8453 | |
9a7e0b18 | 8454 | total = to_ratio(period, runtime); |
6f505b16 | 8455 | |
4653f803 PZ |
8456 | /* |
8457 | * Nobody can have more than the global setting allows. | |
8458 | */ | |
8459 | if (total > to_ratio(global_rt_period(), global_rt_runtime())) | |
8460 | return -EINVAL; | |
6f505b16 | 8461 | |
4653f803 PZ |
8462 | /* |
8463 | * The sum of our children's runtime should not exceed our own. | |
8464 | */ | |
9a7e0b18 PZ |
8465 | list_for_each_entry_rcu(child, &tg->children, siblings) { |
8466 | period = ktime_to_ns(child->rt_bandwidth.rt_period); | |
8467 | runtime = child->rt_bandwidth.rt_runtime; | |
6f505b16 | 8468 | |
9a7e0b18 PZ |
8469 | if (child == d->tg) { |
8470 | period = d->rt_period; | |
8471 | runtime = d->rt_runtime; | |
8472 | } | |
6f505b16 | 8473 | |
9a7e0b18 | 8474 | sum += to_ratio(period, runtime); |
9f0c1e56 | 8475 | } |
6f505b16 | 8476 | |
9a7e0b18 PZ |
8477 | if (sum > total) |
8478 | return -EINVAL; | |
8479 | ||
8480 | return 0; | |
6f505b16 PZ |
8481 | } |
8482 | ||
9a7e0b18 | 8483 | static int __rt_schedulable(struct task_group *tg, u64 period, u64 runtime) |
521f1a24 | 8484 | { |
9a7e0b18 PZ |
8485 | struct rt_schedulable_data data = { |
8486 | .tg = tg, | |
8487 | .rt_period = period, | |
8488 | .rt_runtime = runtime, | |
8489 | }; | |
8490 | ||
8491 | return walk_tg_tree(tg_schedulable, tg_nop, &data); | |
521f1a24 DG |
8492 | } |
8493 | ||
d0b27fa7 PZ |
8494 | static int tg_set_bandwidth(struct task_group *tg, |
8495 | u64 rt_period, u64 rt_runtime) | |
6f505b16 | 8496 | { |
ac086bc2 | 8497 | int i, err = 0; |
9f0c1e56 | 8498 | |
9f0c1e56 | 8499 | mutex_lock(&rt_constraints_mutex); |
521f1a24 | 8500 | read_lock(&tasklist_lock); |
9a7e0b18 PZ |
8501 | err = __rt_schedulable(tg, rt_period, rt_runtime); |
8502 | if (err) | |
9f0c1e56 | 8503 | goto unlock; |
ac086bc2 | 8504 | |
0986b11b | 8505 | raw_spin_lock_irq(&tg->rt_bandwidth.rt_runtime_lock); |
d0b27fa7 PZ |
8506 | tg->rt_bandwidth.rt_period = ns_to_ktime(rt_period); |
8507 | tg->rt_bandwidth.rt_runtime = rt_runtime; | |
ac086bc2 PZ |
8508 | |
8509 | for_each_possible_cpu(i) { | |
8510 | struct rt_rq *rt_rq = tg->rt_rq[i]; | |
8511 | ||
0986b11b | 8512 | raw_spin_lock(&rt_rq->rt_runtime_lock); |
ac086bc2 | 8513 | rt_rq->rt_runtime = rt_runtime; |
0986b11b | 8514 | raw_spin_unlock(&rt_rq->rt_runtime_lock); |
ac086bc2 | 8515 | } |
0986b11b | 8516 | raw_spin_unlock_irq(&tg->rt_bandwidth.rt_runtime_lock); |
9f0c1e56 | 8517 | unlock: |
521f1a24 | 8518 | read_unlock(&tasklist_lock); |
9f0c1e56 PZ |
8519 | mutex_unlock(&rt_constraints_mutex); |
8520 | ||
8521 | return err; | |
6f505b16 PZ |
8522 | } |
8523 | ||
d0b27fa7 PZ |
8524 | int sched_group_set_rt_runtime(struct task_group *tg, long rt_runtime_us) |
8525 | { | |
8526 | u64 rt_runtime, rt_period; | |
8527 | ||
8528 | rt_period = ktime_to_ns(tg->rt_bandwidth.rt_period); | |
8529 | rt_runtime = (u64)rt_runtime_us * NSEC_PER_USEC; | |
8530 | if (rt_runtime_us < 0) | |
8531 | rt_runtime = RUNTIME_INF; | |
8532 | ||
8533 | return tg_set_bandwidth(tg, rt_period, rt_runtime); | |
8534 | } | |
8535 | ||
9f0c1e56 PZ |
8536 | long sched_group_rt_runtime(struct task_group *tg) |
8537 | { | |
8538 | u64 rt_runtime_us; | |
8539 | ||
d0b27fa7 | 8540 | if (tg->rt_bandwidth.rt_runtime == RUNTIME_INF) |
9f0c1e56 PZ |
8541 | return -1; |
8542 | ||
d0b27fa7 | 8543 | rt_runtime_us = tg->rt_bandwidth.rt_runtime; |
9f0c1e56 PZ |
8544 | do_div(rt_runtime_us, NSEC_PER_USEC); |
8545 | return rt_runtime_us; | |
8546 | } | |
d0b27fa7 PZ |
8547 | |
8548 | int sched_group_set_rt_period(struct task_group *tg, long rt_period_us) | |
8549 | { | |
8550 | u64 rt_runtime, rt_period; | |
8551 | ||
8552 | rt_period = (u64)rt_period_us * NSEC_PER_USEC; | |
8553 | rt_runtime = tg->rt_bandwidth.rt_runtime; | |
8554 | ||
619b0488 R |
8555 | if (rt_period == 0) |
8556 | return -EINVAL; | |
8557 | ||
d0b27fa7 PZ |
8558 | return tg_set_bandwidth(tg, rt_period, rt_runtime); |
8559 | } | |
8560 | ||
8561 | long sched_group_rt_period(struct task_group *tg) | |
8562 | { | |
8563 | u64 rt_period_us; | |
8564 | ||
8565 | rt_period_us = ktime_to_ns(tg->rt_bandwidth.rt_period); | |
8566 | do_div(rt_period_us, NSEC_PER_USEC); | |
8567 | return rt_period_us; | |
8568 | } | |
8569 | ||
8570 | static int sched_rt_global_constraints(void) | |
8571 | { | |
4653f803 | 8572 | u64 runtime, period; |
d0b27fa7 PZ |
8573 | int ret = 0; |
8574 | ||
ec5d4989 HS |
8575 | if (sysctl_sched_rt_period <= 0) |
8576 | return -EINVAL; | |
8577 | ||
4653f803 PZ |
8578 | runtime = global_rt_runtime(); |
8579 | period = global_rt_period(); | |
8580 | ||
8581 | /* | |
8582 | * Sanity check on the sysctl variables. | |
8583 | */ | |
8584 | if (runtime > period && runtime != RUNTIME_INF) | |
8585 | return -EINVAL; | |
10b612f4 | 8586 | |
d0b27fa7 | 8587 | mutex_lock(&rt_constraints_mutex); |
9a7e0b18 | 8588 | read_lock(&tasklist_lock); |
4653f803 | 8589 | ret = __rt_schedulable(NULL, 0, 0); |
9a7e0b18 | 8590 | read_unlock(&tasklist_lock); |
d0b27fa7 PZ |
8591 | mutex_unlock(&rt_constraints_mutex); |
8592 | ||
8593 | return ret; | |
8594 | } | |
54e99124 DG |
8595 | |
8596 | int sched_rt_can_attach(struct task_group *tg, struct task_struct *tsk) | |
8597 | { | |
8598 | /* Don't accept realtime tasks when there is no way for them to run */ | |
8599 | if (rt_task(tsk) && tg->rt_bandwidth.rt_runtime == 0) | |
8600 | return 0; | |
8601 | ||
8602 | return 1; | |
8603 | } | |
8604 | ||
6d6bc0ad | 8605 | #else /* !CONFIG_RT_GROUP_SCHED */ |
d0b27fa7 PZ |
8606 | static int sched_rt_global_constraints(void) |
8607 | { | |
ac086bc2 PZ |
8608 | unsigned long flags; |
8609 | int i; | |
8610 | ||
ec5d4989 HS |
8611 | if (sysctl_sched_rt_period <= 0) |
8612 | return -EINVAL; | |
8613 | ||
60aa605d PZ |
8614 | /* |
8615 | * There's always some RT tasks in the root group | |
8616 | * -- migration, kstopmachine etc.. | |
8617 | */ | |
8618 | if (sysctl_sched_rt_runtime == 0) | |
8619 | return -EBUSY; | |
8620 | ||
0986b11b | 8621 | raw_spin_lock_irqsave(&def_rt_bandwidth.rt_runtime_lock, flags); |
ac086bc2 PZ |
8622 | for_each_possible_cpu(i) { |
8623 | struct rt_rq *rt_rq = &cpu_rq(i)->rt; | |
8624 | ||
0986b11b | 8625 | raw_spin_lock(&rt_rq->rt_runtime_lock); |
ac086bc2 | 8626 | rt_rq->rt_runtime = global_rt_runtime(); |
0986b11b | 8627 | raw_spin_unlock(&rt_rq->rt_runtime_lock); |
ac086bc2 | 8628 | } |
0986b11b | 8629 | raw_spin_unlock_irqrestore(&def_rt_bandwidth.rt_runtime_lock, flags); |
ac086bc2 | 8630 | |
d0b27fa7 PZ |
8631 | return 0; |
8632 | } | |
6d6bc0ad | 8633 | #endif /* CONFIG_RT_GROUP_SCHED */ |
d0b27fa7 PZ |
8634 | |
8635 | int sched_rt_handler(struct ctl_table *table, int write, | |
8d65af78 | 8636 | void __user *buffer, size_t *lenp, |
d0b27fa7 PZ |
8637 | loff_t *ppos) |
8638 | { | |
8639 | int ret; | |
8640 | int old_period, old_runtime; | |
8641 | static DEFINE_MUTEX(mutex); | |
8642 | ||
8643 | mutex_lock(&mutex); | |
8644 | old_period = sysctl_sched_rt_period; | |
8645 | old_runtime = sysctl_sched_rt_runtime; | |
8646 | ||
8d65af78 | 8647 | ret = proc_dointvec(table, write, buffer, lenp, ppos); |
d0b27fa7 PZ |
8648 | |
8649 | if (!ret && write) { | |
8650 | ret = sched_rt_global_constraints(); | |
8651 | if (ret) { | |
8652 | sysctl_sched_rt_period = old_period; | |
8653 | sysctl_sched_rt_runtime = old_runtime; | |
8654 | } else { | |
8655 | def_rt_bandwidth.rt_runtime = global_rt_runtime(); | |
8656 | def_rt_bandwidth.rt_period = | |
8657 | ns_to_ktime(global_rt_period()); | |
8658 | } | |
8659 | } | |
8660 | mutex_unlock(&mutex); | |
8661 | ||
8662 | return ret; | |
8663 | } | |
68318b8e | 8664 | |
052f1dc7 | 8665 | #ifdef CONFIG_CGROUP_SCHED |
68318b8e SV |
8666 | |
8667 | /* return corresponding task_group object of a cgroup */ | |
2b01dfe3 | 8668 | static inline struct task_group *cgroup_tg(struct cgroup *cgrp) |
68318b8e | 8669 | { |
2b01dfe3 PM |
8670 | return container_of(cgroup_subsys_state(cgrp, cpu_cgroup_subsys_id), |
8671 | struct task_group, css); | |
68318b8e SV |
8672 | } |
8673 | ||
8674 | static struct cgroup_subsys_state * | |
2b01dfe3 | 8675 | cpu_cgroup_create(struct cgroup_subsys *ss, struct cgroup *cgrp) |
68318b8e | 8676 | { |
ec7dc8ac | 8677 | struct task_group *tg, *parent; |
68318b8e | 8678 | |
2b01dfe3 | 8679 | if (!cgrp->parent) { |
68318b8e | 8680 | /* This is early initialization for the top cgroup */ |
68318b8e SV |
8681 | return &init_task_group.css; |
8682 | } | |
8683 | ||
ec7dc8ac DG |
8684 | parent = cgroup_tg(cgrp->parent); |
8685 | tg = sched_create_group(parent); | |
68318b8e SV |
8686 | if (IS_ERR(tg)) |
8687 | return ERR_PTR(-ENOMEM); | |
8688 | ||
68318b8e SV |
8689 | return &tg->css; |
8690 | } | |
8691 | ||
41a2d6cf IM |
8692 | static void |
8693 | cpu_cgroup_destroy(struct cgroup_subsys *ss, struct cgroup *cgrp) | |
68318b8e | 8694 | { |
2b01dfe3 | 8695 | struct task_group *tg = cgroup_tg(cgrp); |
68318b8e SV |
8696 | |
8697 | sched_destroy_group(tg); | |
8698 | } | |
8699 | ||
41a2d6cf | 8700 | static int |
be367d09 | 8701 | cpu_cgroup_can_attach_task(struct cgroup *cgrp, struct task_struct *tsk) |
68318b8e | 8702 | { |
b68aa230 | 8703 | #ifdef CONFIG_RT_GROUP_SCHED |
54e99124 | 8704 | if (!sched_rt_can_attach(cgroup_tg(cgrp), tsk)) |
b68aa230 PZ |
8705 | return -EINVAL; |
8706 | #else | |
68318b8e SV |
8707 | /* We don't support RT-tasks being in separate groups */ |
8708 | if (tsk->sched_class != &fair_sched_class) | |
8709 | return -EINVAL; | |
b68aa230 | 8710 | #endif |
be367d09 BB |
8711 | return 0; |
8712 | } | |
68318b8e | 8713 | |
be367d09 BB |
8714 | static int |
8715 | cpu_cgroup_can_attach(struct cgroup_subsys *ss, struct cgroup *cgrp, | |
8716 | struct task_struct *tsk, bool threadgroup) | |
8717 | { | |
8718 | int retval = cpu_cgroup_can_attach_task(cgrp, tsk); | |
8719 | if (retval) | |
8720 | return retval; | |
8721 | if (threadgroup) { | |
8722 | struct task_struct *c; | |
8723 | rcu_read_lock(); | |
8724 | list_for_each_entry_rcu(c, &tsk->thread_group, thread_group) { | |
8725 | retval = cpu_cgroup_can_attach_task(cgrp, c); | |
8726 | if (retval) { | |
8727 | rcu_read_unlock(); | |
8728 | return retval; | |
8729 | } | |
8730 | } | |
8731 | rcu_read_unlock(); | |
8732 | } | |
68318b8e SV |
8733 | return 0; |
8734 | } | |
8735 | ||
8736 | static void | |
2b01dfe3 | 8737 | cpu_cgroup_attach(struct cgroup_subsys *ss, struct cgroup *cgrp, |
be367d09 BB |
8738 | struct cgroup *old_cont, struct task_struct *tsk, |
8739 | bool threadgroup) | |
68318b8e SV |
8740 | { |
8741 | sched_move_task(tsk); | |
be367d09 BB |
8742 | if (threadgroup) { |
8743 | struct task_struct *c; | |
8744 | rcu_read_lock(); | |
8745 | list_for_each_entry_rcu(c, &tsk->thread_group, thread_group) { | |
8746 | sched_move_task(c); | |
8747 | } | |
8748 | rcu_read_unlock(); | |
8749 | } | |
68318b8e SV |
8750 | } |
8751 | ||
052f1dc7 | 8752 | #ifdef CONFIG_FAIR_GROUP_SCHED |
f4c753b7 | 8753 | static int cpu_shares_write_u64(struct cgroup *cgrp, struct cftype *cftype, |
2b01dfe3 | 8754 | u64 shareval) |
68318b8e | 8755 | { |
2b01dfe3 | 8756 | return sched_group_set_shares(cgroup_tg(cgrp), shareval); |
68318b8e SV |
8757 | } |
8758 | ||
f4c753b7 | 8759 | static u64 cpu_shares_read_u64(struct cgroup *cgrp, struct cftype *cft) |
68318b8e | 8760 | { |
2b01dfe3 | 8761 | struct task_group *tg = cgroup_tg(cgrp); |
68318b8e SV |
8762 | |
8763 | return (u64) tg->shares; | |
8764 | } | |
6d6bc0ad | 8765 | #endif /* CONFIG_FAIR_GROUP_SCHED */ |
68318b8e | 8766 | |
052f1dc7 | 8767 | #ifdef CONFIG_RT_GROUP_SCHED |
0c70814c | 8768 | static int cpu_rt_runtime_write(struct cgroup *cgrp, struct cftype *cft, |
06ecb27c | 8769 | s64 val) |
6f505b16 | 8770 | { |
06ecb27c | 8771 | return sched_group_set_rt_runtime(cgroup_tg(cgrp), val); |
6f505b16 PZ |
8772 | } |
8773 | ||
06ecb27c | 8774 | static s64 cpu_rt_runtime_read(struct cgroup *cgrp, struct cftype *cft) |
6f505b16 | 8775 | { |
06ecb27c | 8776 | return sched_group_rt_runtime(cgroup_tg(cgrp)); |
6f505b16 | 8777 | } |
d0b27fa7 PZ |
8778 | |
8779 | static int cpu_rt_period_write_uint(struct cgroup *cgrp, struct cftype *cftype, | |
8780 | u64 rt_period_us) | |
8781 | { | |
8782 | return sched_group_set_rt_period(cgroup_tg(cgrp), rt_period_us); | |
8783 | } | |
8784 | ||
8785 | static u64 cpu_rt_period_read_uint(struct cgroup *cgrp, struct cftype *cft) | |
8786 | { | |
8787 | return sched_group_rt_period(cgroup_tg(cgrp)); | |
8788 | } | |
6d6bc0ad | 8789 | #endif /* CONFIG_RT_GROUP_SCHED */ |
6f505b16 | 8790 | |
fe5c7cc2 | 8791 | static struct cftype cpu_files[] = { |
052f1dc7 | 8792 | #ifdef CONFIG_FAIR_GROUP_SCHED |
fe5c7cc2 PM |
8793 | { |
8794 | .name = "shares", | |
f4c753b7 PM |
8795 | .read_u64 = cpu_shares_read_u64, |
8796 | .write_u64 = cpu_shares_write_u64, | |
fe5c7cc2 | 8797 | }, |
052f1dc7 PZ |
8798 | #endif |
8799 | #ifdef CONFIG_RT_GROUP_SCHED | |
6f505b16 | 8800 | { |
9f0c1e56 | 8801 | .name = "rt_runtime_us", |
06ecb27c PM |
8802 | .read_s64 = cpu_rt_runtime_read, |
8803 | .write_s64 = cpu_rt_runtime_write, | |
6f505b16 | 8804 | }, |
d0b27fa7 PZ |
8805 | { |
8806 | .name = "rt_period_us", | |
f4c753b7 PM |
8807 | .read_u64 = cpu_rt_period_read_uint, |
8808 | .write_u64 = cpu_rt_period_write_uint, | |
d0b27fa7 | 8809 | }, |
052f1dc7 | 8810 | #endif |
68318b8e SV |
8811 | }; |
8812 | ||
8813 | static int cpu_cgroup_populate(struct cgroup_subsys *ss, struct cgroup *cont) | |
8814 | { | |
fe5c7cc2 | 8815 | return cgroup_add_files(cont, ss, cpu_files, ARRAY_SIZE(cpu_files)); |
68318b8e SV |
8816 | } |
8817 | ||
8818 | struct cgroup_subsys cpu_cgroup_subsys = { | |
38605cae IM |
8819 | .name = "cpu", |
8820 | .create = cpu_cgroup_create, | |
8821 | .destroy = cpu_cgroup_destroy, | |
8822 | .can_attach = cpu_cgroup_can_attach, | |
8823 | .attach = cpu_cgroup_attach, | |
8824 | .populate = cpu_cgroup_populate, | |
8825 | .subsys_id = cpu_cgroup_subsys_id, | |
68318b8e SV |
8826 | .early_init = 1, |
8827 | }; | |
8828 | ||
052f1dc7 | 8829 | #endif /* CONFIG_CGROUP_SCHED */ |
d842de87 SV |
8830 | |
8831 | #ifdef CONFIG_CGROUP_CPUACCT | |
8832 | ||
8833 | /* | |
8834 | * CPU accounting code for task groups. | |
8835 | * | |
8836 | * Based on the work by Paul Menage (menage@google.com) and Balbir Singh | |
8837 | * (balbir@in.ibm.com). | |
8838 | */ | |
8839 | ||
934352f2 | 8840 | /* track cpu usage of a group of tasks and its child groups */ |
d842de87 SV |
8841 | struct cpuacct { |
8842 | struct cgroup_subsys_state css; | |
8843 | /* cpuusage holds pointer to a u64-type object on every cpu */ | |
43cf38eb | 8844 | u64 __percpu *cpuusage; |
ef12fefa | 8845 | struct percpu_counter cpustat[CPUACCT_STAT_NSTATS]; |
934352f2 | 8846 | struct cpuacct *parent; |
d842de87 SV |
8847 | }; |
8848 | ||
8849 | struct cgroup_subsys cpuacct_subsys; | |
8850 | ||
8851 | /* return cpu accounting group corresponding to this container */ | |
32cd756a | 8852 | static inline struct cpuacct *cgroup_ca(struct cgroup *cgrp) |
d842de87 | 8853 | { |
32cd756a | 8854 | return container_of(cgroup_subsys_state(cgrp, cpuacct_subsys_id), |
d842de87 SV |
8855 | struct cpuacct, css); |
8856 | } | |
8857 | ||
8858 | /* return cpu accounting group to which this task belongs */ | |
8859 | static inline struct cpuacct *task_ca(struct task_struct *tsk) | |
8860 | { | |
8861 | return container_of(task_subsys_state(tsk, cpuacct_subsys_id), | |
8862 | struct cpuacct, css); | |
8863 | } | |
8864 | ||
8865 | /* create a new cpu accounting group */ | |
8866 | static struct cgroup_subsys_state *cpuacct_create( | |
32cd756a | 8867 | struct cgroup_subsys *ss, struct cgroup *cgrp) |
d842de87 SV |
8868 | { |
8869 | struct cpuacct *ca = kzalloc(sizeof(*ca), GFP_KERNEL); | |
ef12fefa | 8870 | int i; |
d842de87 SV |
8871 | |
8872 | if (!ca) | |
ef12fefa | 8873 | goto out; |
d842de87 SV |
8874 | |
8875 | ca->cpuusage = alloc_percpu(u64); | |
ef12fefa BR |
8876 | if (!ca->cpuusage) |
8877 | goto out_free_ca; | |
8878 | ||
8879 | for (i = 0; i < CPUACCT_STAT_NSTATS; i++) | |
8880 | if (percpu_counter_init(&ca->cpustat[i], 0)) | |
8881 | goto out_free_counters; | |
d842de87 | 8882 | |
934352f2 BR |
8883 | if (cgrp->parent) |
8884 | ca->parent = cgroup_ca(cgrp->parent); | |
8885 | ||
d842de87 | 8886 | return &ca->css; |
ef12fefa BR |
8887 | |
8888 | out_free_counters: | |
8889 | while (--i >= 0) | |
8890 | percpu_counter_destroy(&ca->cpustat[i]); | |
8891 | free_percpu(ca->cpuusage); | |
8892 | out_free_ca: | |
8893 | kfree(ca); | |
8894 | out: | |
8895 | return ERR_PTR(-ENOMEM); | |
d842de87 SV |
8896 | } |
8897 | ||
8898 | /* destroy an existing cpu accounting group */ | |
41a2d6cf | 8899 | static void |
32cd756a | 8900 | cpuacct_destroy(struct cgroup_subsys *ss, struct cgroup *cgrp) |
d842de87 | 8901 | { |
32cd756a | 8902 | struct cpuacct *ca = cgroup_ca(cgrp); |
ef12fefa | 8903 | int i; |
d842de87 | 8904 | |
ef12fefa BR |
8905 | for (i = 0; i < CPUACCT_STAT_NSTATS; i++) |
8906 | percpu_counter_destroy(&ca->cpustat[i]); | |
d842de87 SV |
8907 | free_percpu(ca->cpuusage); |
8908 | kfree(ca); | |
8909 | } | |
8910 | ||
720f5498 KC |
8911 | static u64 cpuacct_cpuusage_read(struct cpuacct *ca, int cpu) |
8912 | { | |
b36128c8 | 8913 | u64 *cpuusage = per_cpu_ptr(ca->cpuusage, cpu); |
720f5498 KC |
8914 | u64 data; |
8915 | ||
8916 | #ifndef CONFIG_64BIT | |
8917 | /* | |
8918 | * Take rq->lock to make 64-bit read safe on 32-bit platforms. | |
8919 | */ | |
05fa785c | 8920 | raw_spin_lock_irq(&cpu_rq(cpu)->lock); |
720f5498 | 8921 | data = *cpuusage; |
05fa785c | 8922 | raw_spin_unlock_irq(&cpu_rq(cpu)->lock); |
720f5498 KC |
8923 | #else |
8924 | data = *cpuusage; | |
8925 | #endif | |
8926 | ||
8927 | return data; | |
8928 | } | |
8929 | ||
8930 | static void cpuacct_cpuusage_write(struct cpuacct *ca, int cpu, u64 val) | |
8931 | { | |
b36128c8 | 8932 | u64 *cpuusage = per_cpu_ptr(ca->cpuusage, cpu); |
720f5498 KC |
8933 | |
8934 | #ifndef CONFIG_64BIT | |
8935 | /* | |
8936 | * Take rq->lock to make 64-bit write safe on 32-bit platforms. | |
8937 | */ | |
05fa785c | 8938 | raw_spin_lock_irq(&cpu_rq(cpu)->lock); |
720f5498 | 8939 | *cpuusage = val; |
05fa785c | 8940 | raw_spin_unlock_irq(&cpu_rq(cpu)->lock); |
720f5498 KC |
8941 | #else |
8942 | *cpuusage = val; | |
8943 | #endif | |
8944 | } | |
8945 | ||
d842de87 | 8946 | /* return total cpu usage (in nanoseconds) of a group */ |
32cd756a | 8947 | static u64 cpuusage_read(struct cgroup *cgrp, struct cftype *cft) |
d842de87 | 8948 | { |
32cd756a | 8949 | struct cpuacct *ca = cgroup_ca(cgrp); |
d842de87 SV |
8950 | u64 totalcpuusage = 0; |
8951 | int i; | |
8952 | ||
720f5498 KC |
8953 | for_each_present_cpu(i) |
8954 | totalcpuusage += cpuacct_cpuusage_read(ca, i); | |
d842de87 SV |
8955 | |
8956 | return totalcpuusage; | |
8957 | } | |
8958 | ||
0297b803 DG |
8959 | static int cpuusage_write(struct cgroup *cgrp, struct cftype *cftype, |
8960 | u64 reset) | |
8961 | { | |
8962 | struct cpuacct *ca = cgroup_ca(cgrp); | |
8963 | int err = 0; | |
8964 | int i; | |
8965 | ||
8966 | if (reset) { | |
8967 | err = -EINVAL; | |
8968 | goto out; | |
8969 | } | |
8970 | ||
720f5498 KC |
8971 | for_each_present_cpu(i) |
8972 | cpuacct_cpuusage_write(ca, i, 0); | |
0297b803 | 8973 | |
0297b803 DG |
8974 | out: |
8975 | return err; | |
8976 | } | |
8977 | ||
e9515c3c KC |
8978 | static int cpuacct_percpu_seq_read(struct cgroup *cgroup, struct cftype *cft, |
8979 | struct seq_file *m) | |
8980 | { | |
8981 | struct cpuacct *ca = cgroup_ca(cgroup); | |
8982 | u64 percpu; | |
8983 | int i; | |
8984 | ||
8985 | for_each_present_cpu(i) { | |
8986 | percpu = cpuacct_cpuusage_read(ca, i); | |
8987 | seq_printf(m, "%llu ", (unsigned long long) percpu); | |
8988 | } | |
8989 | seq_printf(m, "\n"); | |
8990 | return 0; | |
8991 | } | |
8992 | ||
ef12fefa BR |
8993 | static const char *cpuacct_stat_desc[] = { |
8994 | [CPUACCT_STAT_USER] = "user", | |
8995 | [CPUACCT_STAT_SYSTEM] = "system", | |
8996 | }; | |
8997 | ||
8998 | static int cpuacct_stats_show(struct cgroup *cgrp, struct cftype *cft, | |
8999 | struct cgroup_map_cb *cb) | |
9000 | { | |
9001 | struct cpuacct *ca = cgroup_ca(cgrp); | |
9002 | int i; | |
9003 | ||
9004 | for (i = 0; i < CPUACCT_STAT_NSTATS; i++) { | |
9005 | s64 val = percpu_counter_read(&ca->cpustat[i]); | |
9006 | val = cputime64_to_clock_t(val); | |
9007 | cb->fill(cb, cpuacct_stat_desc[i], val); | |
9008 | } | |
9009 | return 0; | |
9010 | } | |
9011 | ||
d842de87 SV |
9012 | static struct cftype files[] = { |
9013 | { | |
9014 | .name = "usage", | |
f4c753b7 PM |
9015 | .read_u64 = cpuusage_read, |
9016 | .write_u64 = cpuusage_write, | |
d842de87 | 9017 | }, |
e9515c3c KC |
9018 | { |
9019 | .name = "usage_percpu", | |
9020 | .read_seq_string = cpuacct_percpu_seq_read, | |
9021 | }, | |
ef12fefa BR |
9022 | { |
9023 | .name = "stat", | |
9024 | .read_map = cpuacct_stats_show, | |
9025 | }, | |
d842de87 SV |
9026 | }; |
9027 | ||
32cd756a | 9028 | static int cpuacct_populate(struct cgroup_subsys *ss, struct cgroup *cgrp) |
d842de87 | 9029 | { |
32cd756a | 9030 | return cgroup_add_files(cgrp, ss, files, ARRAY_SIZE(files)); |
d842de87 SV |
9031 | } |
9032 | ||
9033 | /* | |
9034 | * charge this task's execution time to its accounting group. | |
9035 | * | |
9036 | * called with rq->lock held. | |
9037 | */ | |
9038 | static void cpuacct_charge(struct task_struct *tsk, u64 cputime) | |
9039 | { | |
9040 | struct cpuacct *ca; | |
934352f2 | 9041 | int cpu; |
d842de87 | 9042 | |
c40c6f85 | 9043 | if (unlikely(!cpuacct_subsys.active)) |
d842de87 SV |
9044 | return; |
9045 | ||
934352f2 | 9046 | cpu = task_cpu(tsk); |
a18b83b7 BR |
9047 | |
9048 | rcu_read_lock(); | |
9049 | ||
d842de87 | 9050 | ca = task_ca(tsk); |
d842de87 | 9051 | |
934352f2 | 9052 | for (; ca; ca = ca->parent) { |
b36128c8 | 9053 | u64 *cpuusage = per_cpu_ptr(ca->cpuusage, cpu); |
d842de87 SV |
9054 | *cpuusage += cputime; |
9055 | } | |
a18b83b7 BR |
9056 | |
9057 | rcu_read_unlock(); | |
d842de87 SV |
9058 | } |
9059 | ||
fa535a77 AB |
9060 | /* |
9061 | * When CONFIG_VIRT_CPU_ACCOUNTING is enabled one jiffy can be very large | |
9062 | * in cputime_t units. As a result, cpuacct_update_stats calls | |
9063 | * percpu_counter_add with values large enough to always overflow the | |
9064 | * per cpu batch limit causing bad SMP scalability. | |
9065 | * | |
9066 | * To fix this we scale percpu_counter_batch by cputime_one_jiffy so we | |
9067 | * batch the same amount of time with CONFIG_VIRT_CPU_ACCOUNTING disabled | |
9068 | * and enabled. We cap it at INT_MAX which is the largest allowed batch value. | |
9069 | */ | |
9070 | #ifdef CONFIG_SMP | |
9071 | #define CPUACCT_BATCH \ | |
9072 | min_t(long, percpu_counter_batch * cputime_one_jiffy, INT_MAX) | |
9073 | #else | |
9074 | #define CPUACCT_BATCH 0 | |
9075 | #endif | |
9076 | ||
ef12fefa BR |
9077 | /* |
9078 | * Charge the system/user time to the task's accounting group. | |
9079 | */ | |
9080 | static void cpuacct_update_stats(struct task_struct *tsk, | |
9081 | enum cpuacct_stat_index idx, cputime_t val) | |
9082 | { | |
9083 | struct cpuacct *ca; | |
fa535a77 | 9084 | int batch = CPUACCT_BATCH; |
ef12fefa BR |
9085 | |
9086 | if (unlikely(!cpuacct_subsys.active)) | |
9087 | return; | |
9088 | ||
9089 | rcu_read_lock(); | |
9090 | ca = task_ca(tsk); | |
9091 | ||
9092 | do { | |
fa535a77 | 9093 | __percpu_counter_add(&ca->cpustat[idx], val, batch); |
ef12fefa BR |
9094 | ca = ca->parent; |
9095 | } while (ca); | |
9096 | rcu_read_unlock(); | |
9097 | } | |
9098 | ||
d842de87 SV |
9099 | struct cgroup_subsys cpuacct_subsys = { |
9100 | .name = "cpuacct", | |
9101 | .create = cpuacct_create, | |
9102 | .destroy = cpuacct_destroy, | |
9103 | .populate = cpuacct_populate, | |
9104 | .subsys_id = cpuacct_subsys_id, | |
9105 | }; | |
9106 | #endif /* CONFIG_CGROUP_CPUACCT */ | |
03b042bf PM |
9107 | |
9108 | #ifndef CONFIG_SMP | |
9109 | ||
03b042bf PM |
9110 | void synchronize_sched_expedited(void) |
9111 | { | |
fc390cde | 9112 | barrier(); |
03b042bf PM |
9113 | } |
9114 | EXPORT_SYMBOL_GPL(synchronize_sched_expedited); | |
9115 | ||
9116 | #else /* #ifndef CONFIG_SMP */ | |
9117 | ||
cc631fb7 | 9118 | static atomic_t synchronize_sched_expedited_count = ATOMIC_INIT(0); |
03b042bf | 9119 | |
cc631fb7 | 9120 | static int synchronize_sched_expedited_cpu_stop(void *data) |
03b042bf | 9121 | { |
969c7921 TH |
9122 | /* |
9123 | * There must be a full memory barrier on each affected CPU | |
9124 | * between the time that try_stop_cpus() is called and the | |
9125 | * time that it returns. | |
9126 | * | |
9127 | * In the current initial implementation of cpu_stop, the | |
9128 | * above condition is already met when the control reaches | |
9129 | * this point and the following smp_mb() is not strictly | |
9130 | * necessary. Do smp_mb() anyway for documentation and | |
9131 | * robustness against future implementation changes. | |
9132 | */ | |
cc631fb7 | 9133 | smp_mb(); /* See above comment block. */ |
969c7921 | 9134 | return 0; |
03b042bf | 9135 | } |
03b042bf PM |
9136 | |
9137 | /* | |
9138 | * Wait for an rcu-sched grace period to elapse, but use "big hammer" | |
9139 | * approach to force grace period to end quickly. This consumes | |
9140 | * significant time on all CPUs, and is thus not recommended for | |
9141 | * any sort of common-case code. | |
9142 | * | |
9143 | * Note that it is illegal to call this function while holding any | |
9144 | * lock that is acquired by a CPU-hotplug notifier. Failing to | |
9145 | * observe this restriction will result in deadlock. | |
9146 | */ | |
9147 | void synchronize_sched_expedited(void) | |
9148 | { | |
969c7921 | 9149 | int snap, trycount = 0; |
03b042bf PM |
9150 | |
9151 | smp_mb(); /* ensure prior mod happens before capturing snap. */ | |
969c7921 | 9152 | snap = atomic_read(&synchronize_sched_expedited_count) + 1; |
03b042bf | 9153 | get_online_cpus(); |
969c7921 TH |
9154 | while (try_stop_cpus(cpu_online_mask, |
9155 | synchronize_sched_expedited_cpu_stop, | |
94458d5e | 9156 | NULL) == -EAGAIN) { |
03b042bf PM |
9157 | put_online_cpus(); |
9158 | if (trycount++ < 10) | |
9159 | udelay(trycount * num_online_cpus()); | |
9160 | else { | |
9161 | synchronize_sched(); | |
9162 | return; | |
9163 | } | |
969c7921 | 9164 | if (atomic_read(&synchronize_sched_expedited_count) - snap > 0) { |
03b042bf PM |
9165 | smp_mb(); /* ensure test happens before caller kfree */ |
9166 | return; | |
9167 | } | |
9168 | get_online_cpus(); | |
9169 | } | |
969c7921 | 9170 | atomic_inc(&synchronize_sched_expedited_count); |
cc631fb7 | 9171 | smp_mb__after_atomic_inc(); /* ensure post-GP actions seen after GP. */ |
03b042bf | 9172 | put_online_cpus(); |
03b042bf PM |
9173 | } |
9174 | EXPORT_SYMBOL_GPL(synchronize_sched_expedited); | |
9175 | ||
9176 | #endif /* #else #ifndef CONFIG_SMP */ |