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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> |
1da177e4 LT |
42 | #include <linux/security.h> |
43 | #include <linux/notifier.h> | |
44 | #include <linux/profile.h> | |
7dfb7103 | 45 | #include <linux/freezer.h> |
198e2f18 | 46 | #include <linux/vmalloc.h> |
1da177e4 LT |
47 | #include <linux/blkdev.h> |
48 | #include <linux/delay.h> | |
b488893a | 49 | #include <linux/pid_namespace.h> |
1da177e4 LT |
50 | #include <linux/smp.h> |
51 | #include <linux/threads.h> | |
52 | #include <linux/timer.h> | |
53 | #include <linux/rcupdate.h> | |
54 | #include <linux/cpu.h> | |
55 | #include <linux/cpuset.h> | |
56 | #include <linux/percpu.h> | |
57 | #include <linux/kthread.h> | |
b5aadf7f | 58 | #include <linux/proc_fs.h> |
1da177e4 | 59 | #include <linux/seq_file.h> |
e692ab53 | 60 | #include <linux/sysctl.h> |
1da177e4 LT |
61 | #include <linux/syscalls.h> |
62 | #include <linux/times.h> | |
8f0ab514 | 63 | #include <linux/tsacct_kern.h> |
c6fd91f0 | 64 | #include <linux/kprobes.h> |
0ff92245 | 65 | #include <linux/delayacct.h> |
5517d86b | 66 | #include <linux/reciprocal_div.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> |
434d53b0 | 71 | #include <linux/bootmem.h> |
f00b45c1 PZ |
72 | #include <linux/debugfs.h> |
73 | #include <linux/ctype.h> | |
6cd8a4bb | 74 | #include <linux/ftrace.h> |
0a16b607 | 75 | #include <trace/sched.h> |
1da177e4 | 76 | |
5517d86b | 77 | #include <asm/tlb.h> |
838225b4 | 78 | #include <asm/irq_regs.h> |
1da177e4 | 79 | |
6e0534f2 GH |
80 | #include "sched_cpupri.h" |
81 | ||
1da177e4 LT |
82 | /* |
83 | * Convert user-nice values [ -20 ... 0 ... 19 ] | |
84 | * to static priority [ MAX_RT_PRIO..MAX_PRIO-1 ], | |
85 | * and back. | |
86 | */ | |
87 | #define NICE_TO_PRIO(nice) (MAX_RT_PRIO + (nice) + 20) | |
88 | #define PRIO_TO_NICE(prio) ((prio) - MAX_RT_PRIO - 20) | |
89 | #define TASK_NICE(p) PRIO_TO_NICE((p)->static_prio) | |
90 | ||
91 | /* | |
92 | * 'User priority' is the nice value converted to something we | |
93 | * can work with better when scaling various scheduler parameters, | |
94 | * it's a [ 0 ... 39 ] range. | |
95 | */ | |
96 | #define USER_PRIO(p) ((p)-MAX_RT_PRIO) | |
97 | #define TASK_USER_PRIO(p) USER_PRIO((p)->static_prio) | |
98 | #define MAX_USER_PRIO (USER_PRIO(MAX_PRIO)) | |
99 | ||
100 | /* | |
d7876a08 | 101 | * Helpers for converting nanosecond timing to jiffy resolution |
1da177e4 | 102 | */ |
d6322faf | 103 | #define NS_TO_JIFFIES(TIME) ((unsigned long)(TIME) / (NSEC_PER_SEC / HZ)) |
1da177e4 | 104 | |
6aa645ea IM |
105 | #define NICE_0_LOAD SCHED_LOAD_SCALE |
106 | #define NICE_0_SHIFT SCHED_LOAD_SHIFT | |
107 | ||
1da177e4 LT |
108 | /* |
109 | * These are the 'tuning knobs' of the scheduler: | |
110 | * | |
a4ec24b4 | 111 | * default timeslice is 100 msecs (used only for SCHED_RR tasks). |
1da177e4 LT |
112 | * Timeslices get refilled after they expire. |
113 | */ | |
1da177e4 | 114 | #define DEF_TIMESLICE (100 * HZ / 1000) |
2dd73a4f | 115 | |
d0b27fa7 PZ |
116 | /* |
117 | * single value that denotes runtime == period, ie unlimited time. | |
118 | */ | |
119 | #define RUNTIME_INF ((u64)~0ULL) | |
120 | ||
7e066fb8 MD |
121 | DEFINE_TRACE(sched_wait_task); |
122 | DEFINE_TRACE(sched_wakeup); | |
123 | DEFINE_TRACE(sched_wakeup_new); | |
124 | DEFINE_TRACE(sched_switch); | |
125 | DEFINE_TRACE(sched_migrate_task); | |
126 | ||
5517d86b | 127 | #ifdef CONFIG_SMP |
fd2ab30b SN |
128 | |
129 | static void double_rq_lock(struct rq *rq1, struct rq *rq2); | |
130 | ||
5517d86b ED |
131 | /* |
132 | * Divide a load by a sched group cpu_power : (load / sg->__cpu_power) | |
133 | * Since cpu_power is a 'constant', we can use a reciprocal divide. | |
134 | */ | |
135 | static inline u32 sg_div_cpu_power(const struct sched_group *sg, u32 load) | |
136 | { | |
137 | return reciprocal_divide(load, sg->reciprocal_cpu_power); | |
138 | } | |
139 | ||
140 | /* | |
141 | * Each time a sched group cpu_power is changed, | |
142 | * we must compute its reciprocal value | |
143 | */ | |
144 | static inline void sg_inc_cpu_power(struct sched_group *sg, u32 val) | |
145 | { | |
146 | sg->__cpu_power += val; | |
147 | sg->reciprocal_cpu_power = reciprocal_value(sg->__cpu_power); | |
148 | } | |
149 | #endif | |
150 | ||
e05606d3 IM |
151 | static inline int rt_policy(int policy) |
152 | { | |
3f33a7ce | 153 | if (unlikely(policy == SCHED_FIFO || policy == SCHED_RR)) |
e05606d3 IM |
154 | return 1; |
155 | return 0; | |
156 | } | |
157 | ||
158 | static inline int task_has_rt_policy(struct task_struct *p) | |
159 | { | |
160 | return rt_policy(p->policy); | |
161 | } | |
162 | ||
1da177e4 | 163 | /* |
6aa645ea | 164 | * This is the priority-queue data structure of the RT scheduling class: |
1da177e4 | 165 | */ |
6aa645ea IM |
166 | struct rt_prio_array { |
167 | DECLARE_BITMAP(bitmap, MAX_RT_PRIO+1); /* include 1 bit for delimiter */ | |
168 | struct list_head queue[MAX_RT_PRIO]; | |
169 | }; | |
170 | ||
d0b27fa7 | 171 | struct rt_bandwidth { |
ea736ed5 IM |
172 | /* nests inside the rq lock: */ |
173 | spinlock_t rt_runtime_lock; | |
174 | ktime_t rt_period; | |
175 | u64 rt_runtime; | |
176 | struct hrtimer rt_period_timer; | |
d0b27fa7 PZ |
177 | }; |
178 | ||
179 | static struct rt_bandwidth def_rt_bandwidth; | |
180 | ||
181 | static int do_sched_rt_period_timer(struct rt_bandwidth *rt_b, int overrun); | |
182 | ||
183 | static enum hrtimer_restart sched_rt_period_timer(struct hrtimer *timer) | |
184 | { | |
185 | struct rt_bandwidth *rt_b = | |
186 | container_of(timer, struct rt_bandwidth, rt_period_timer); | |
187 | ktime_t now; | |
188 | int overrun; | |
189 | int idle = 0; | |
190 | ||
191 | for (;;) { | |
192 | now = hrtimer_cb_get_time(timer); | |
193 | overrun = hrtimer_forward(timer, now, rt_b->rt_period); | |
194 | ||
195 | if (!overrun) | |
196 | break; | |
197 | ||
198 | idle = do_sched_rt_period_timer(rt_b, overrun); | |
199 | } | |
200 | ||
201 | return idle ? HRTIMER_NORESTART : HRTIMER_RESTART; | |
202 | } | |
203 | ||
204 | static | |
205 | void init_rt_bandwidth(struct rt_bandwidth *rt_b, u64 period, u64 runtime) | |
206 | { | |
207 | rt_b->rt_period = ns_to_ktime(period); | |
208 | rt_b->rt_runtime = runtime; | |
209 | ||
ac086bc2 PZ |
210 | spin_lock_init(&rt_b->rt_runtime_lock); |
211 | ||
d0b27fa7 PZ |
212 | hrtimer_init(&rt_b->rt_period_timer, |
213 | CLOCK_MONOTONIC, HRTIMER_MODE_REL); | |
214 | rt_b->rt_period_timer.function = sched_rt_period_timer; | |
d0b27fa7 PZ |
215 | } |
216 | ||
c8bfff6d KH |
217 | static inline int rt_bandwidth_enabled(void) |
218 | { | |
219 | return sysctl_sched_rt_runtime >= 0; | |
d0b27fa7 PZ |
220 | } |
221 | ||
222 | static void start_rt_bandwidth(struct rt_bandwidth *rt_b) | |
223 | { | |
224 | ktime_t now; | |
225 | ||
0b148fa0 | 226 | if (rt_bandwidth_enabled() && rt_b->rt_runtime == RUNTIME_INF) |
d0b27fa7 PZ |
227 | return; |
228 | ||
229 | if (hrtimer_active(&rt_b->rt_period_timer)) | |
230 | return; | |
231 | ||
232 | spin_lock(&rt_b->rt_runtime_lock); | |
233 | for (;;) { | |
234 | if (hrtimer_active(&rt_b->rt_period_timer)) | |
235 | break; | |
236 | ||
237 | now = hrtimer_cb_get_time(&rt_b->rt_period_timer); | |
238 | hrtimer_forward(&rt_b->rt_period_timer, now, rt_b->rt_period); | |
cc584b21 AV |
239 | hrtimer_start_expires(&rt_b->rt_period_timer, |
240 | HRTIMER_MODE_ABS); | |
d0b27fa7 PZ |
241 | } |
242 | spin_unlock(&rt_b->rt_runtime_lock); | |
243 | } | |
244 | ||
245 | #ifdef CONFIG_RT_GROUP_SCHED | |
246 | static void destroy_rt_bandwidth(struct rt_bandwidth *rt_b) | |
247 | { | |
248 | hrtimer_cancel(&rt_b->rt_period_timer); | |
249 | } | |
250 | #endif | |
251 | ||
712555ee HC |
252 | /* |
253 | * sched_domains_mutex serializes calls to arch_init_sched_domains, | |
254 | * detach_destroy_domains and partition_sched_domains. | |
255 | */ | |
256 | static DEFINE_MUTEX(sched_domains_mutex); | |
257 | ||
052f1dc7 | 258 | #ifdef CONFIG_GROUP_SCHED |
29f59db3 | 259 | |
68318b8e SV |
260 | #include <linux/cgroup.h> |
261 | ||
29f59db3 SV |
262 | struct cfs_rq; |
263 | ||
6f505b16 PZ |
264 | static LIST_HEAD(task_groups); |
265 | ||
29f59db3 | 266 | /* task group related information */ |
4cf86d77 | 267 | struct task_group { |
052f1dc7 | 268 | #ifdef CONFIG_CGROUP_SCHED |
68318b8e SV |
269 | struct cgroup_subsys_state css; |
270 | #endif | |
052f1dc7 | 271 | |
6c415b92 AB |
272 | #ifdef CONFIG_USER_SCHED |
273 | uid_t uid; | |
274 | #endif | |
275 | ||
052f1dc7 | 276 | #ifdef CONFIG_FAIR_GROUP_SCHED |
29f59db3 SV |
277 | /* schedulable entities of this group on each cpu */ |
278 | struct sched_entity **se; | |
279 | /* runqueue "owned" by this group on each cpu */ | |
280 | struct cfs_rq **cfs_rq; | |
281 | unsigned long shares; | |
052f1dc7 PZ |
282 | #endif |
283 | ||
284 | #ifdef CONFIG_RT_GROUP_SCHED | |
285 | struct sched_rt_entity **rt_se; | |
286 | struct rt_rq **rt_rq; | |
287 | ||
d0b27fa7 | 288 | struct rt_bandwidth rt_bandwidth; |
052f1dc7 | 289 | #endif |
6b2d7700 | 290 | |
ae8393e5 | 291 | struct rcu_head rcu; |
6f505b16 | 292 | struct list_head list; |
f473aa5e PZ |
293 | |
294 | struct task_group *parent; | |
295 | struct list_head siblings; | |
296 | struct list_head children; | |
29f59db3 SV |
297 | }; |
298 | ||
354d60c2 | 299 | #ifdef CONFIG_USER_SCHED |
eff766a6 | 300 | |
6c415b92 AB |
301 | /* Helper function to pass uid information to create_sched_user() */ |
302 | void set_tg_uid(struct user_struct *user) | |
303 | { | |
304 | user->tg->uid = user->uid; | |
305 | } | |
306 | ||
eff766a6 PZ |
307 | /* |
308 | * Root task group. | |
309 | * Every UID task group (including init_task_group aka UID-0) will | |
310 | * be a child to this group. | |
311 | */ | |
312 | struct task_group root_task_group; | |
313 | ||
052f1dc7 | 314 | #ifdef CONFIG_FAIR_GROUP_SCHED |
29f59db3 SV |
315 | /* Default task group's sched entity on each cpu */ |
316 | static DEFINE_PER_CPU(struct sched_entity, init_sched_entity); | |
317 | /* Default task group's cfs_rq on each cpu */ | |
318 | static DEFINE_PER_CPU(struct cfs_rq, init_cfs_rq) ____cacheline_aligned_in_smp; | |
6d6bc0ad | 319 | #endif /* CONFIG_FAIR_GROUP_SCHED */ |
052f1dc7 PZ |
320 | |
321 | #ifdef CONFIG_RT_GROUP_SCHED | |
322 | static DEFINE_PER_CPU(struct sched_rt_entity, init_sched_rt_entity); | |
323 | static DEFINE_PER_CPU(struct rt_rq, init_rt_rq) ____cacheline_aligned_in_smp; | |
6d6bc0ad | 324 | #endif /* CONFIG_RT_GROUP_SCHED */ |
9a7e0b18 | 325 | #else /* !CONFIG_USER_SCHED */ |
eff766a6 | 326 | #define root_task_group init_task_group |
9a7e0b18 | 327 | #endif /* CONFIG_USER_SCHED */ |
6f505b16 | 328 | |
8ed36996 | 329 | /* task_group_lock serializes add/remove of task groups and also changes to |
ec2c507f SV |
330 | * a task group's cpu shares. |
331 | */ | |
8ed36996 | 332 | static DEFINE_SPINLOCK(task_group_lock); |
ec2c507f | 333 | |
052f1dc7 | 334 | #ifdef CONFIG_FAIR_GROUP_SCHED |
052f1dc7 PZ |
335 | #ifdef CONFIG_USER_SCHED |
336 | # define INIT_TASK_GROUP_LOAD (2*NICE_0_LOAD) | |
6d6bc0ad | 337 | #else /* !CONFIG_USER_SCHED */ |
052f1dc7 | 338 | # define INIT_TASK_GROUP_LOAD NICE_0_LOAD |
6d6bc0ad | 339 | #endif /* CONFIG_USER_SCHED */ |
052f1dc7 | 340 | |
cb4ad1ff | 341 | /* |
2e084786 LJ |
342 | * A weight of 0 or 1 can cause arithmetics problems. |
343 | * A weight of a cfs_rq is the sum of weights of which entities | |
344 | * are queued on this cfs_rq, so a weight of a entity should not be | |
345 | * too large, so as the shares value of a task group. | |
cb4ad1ff MX |
346 | * (The default weight is 1024 - so there's no practical |
347 | * limitation from this.) | |
348 | */ | |
18d95a28 | 349 | #define MIN_SHARES 2 |
2e084786 | 350 | #define MAX_SHARES (1UL << 18) |
18d95a28 | 351 | |
052f1dc7 PZ |
352 | static int init_task_group_load = INIT_TASK_GROUP_LOAD; |
353 | #endif | |
354 | ||
29f59db3 | 355 | /* Default task group. |
3a252015 | 356 | * Every task in system belong to this group at bootup. |
29f59db3 | 357 | */ |
434d53b0 | 358 | struct task_group init_task_group; |
29f59db3 SV |
359 | |
360 | /* return group to which a task belongs */ | |
4cf86d77 | 361 | static inline struct task_group *task_group(struct task_struct *p) |
29f59db3 | 362 | { |
4cf86d77 | 363 | struct task_group *tg; |
9b5b7751 | 364 | |
052f1dc7 | 365 | #ifdef CONFIG_USER_SCHED |
c69e8d9c DH |
366 | rcu_read_lock(); |
367 | tg = __task_cred(p)->user->tg; | |
368 | rcu_read_unlock(); | |
052f1dc7 | 369 | #elif defined(CONFIG_CGROUP_SCHED) |
68318b8e SV |
370 | tg = container_of(task_subsys_state(p, cpu_cgroup_subsys_id), |
371 | struct task_group, css); | |
24e377a8 | 372 | #else |
41a2d6cf | 373 | tg = &init_task_group; |
24e377a8 | 374 | #endif |
9b5b7751 | 375 | return tg; |
29f59db3 SV |
376 | } |
377 | ||
378 | /* Change a task's cfs_rq and parent entity if it moves across CPUs/groups */ | |
6f505b16 | 379 | static inline void set_task_rq(struct task_struct *p, unsigned int cpu) |
29f59db3 | 380 | { |
052f1dc7 | 381 | #ifdef CONFIG_FAIR_GROUP_SCHED |
ce96b5ac DA |
382 | p->se.cfs_rq = task_group(p)->cfs_rq[cpu]; |
383 | p->se.parent = task_group(p)->se[cpu]; | |
052f1dc7 | 384 | #endif |
6f505b16 | 385 | |
052f1dc7 | 386 | #ifdef CONFIG_RT_GROUP_SCHED |
6f505b16 PZ |
387 | p->rt.rt_rq = task_group(p)->rt_rq[cpu]; |
388 | p->rt.parent = task_group(p)->rt_se[cpu]; | |
052f1dc7 | 389 | #endif |
29f59db3 SV |
390 | } |
391 | ||
392 | #else | |
393 | ||
6f505b16 | 394 | static inline void set_task_rq(struct task_struct *p, unsigned int cpu) { } |
83378269 PZ |
395 | static inline struct task_group *task_group(struct task_struct *p) |
396 | { | |
397 | return NULL; | |
398 | } | |
29f59db3 | 399 | |
052f1dc7 | 400 | #endif /* CONFIG_GROUP_SCHED */ |
29f59db3 | 401 | |
6aa645ea IM |
402 | /* CFS-related fields in a runqueue */ |
403 | struct cfs_rq { | |
404 | struct load_weight load; | |
405 | unsigned long nr_running; | |
406 | ||
6aa645ea | 407 | u64 exec_clock; |
e9acbff6 | 408 | u64 min_vruntime; |
6aa645ea IM |
409 | |
410 | struct rb_root tasks_timeline; | |
411 | struct rb_node *rb_leftmost; | |
4a55bd5e PZ |
412 | |
413 | struct list_head tasks; | |
414 | struct list_head *balance_iterator; | |
415 | ||
416 | /* | |
417 | * 'curr' points to currently running entity on this cfs_rq. | |
6aa645ea IM |
418 | * It is set to NULL otherwise (i.e when none are currently running). |
419 | */ | |
4793241b | 420 | struct sched_entity *curr, *next, *last; |
ddc97297 | 421 | |
5ac5c4d6 | 422 | unsigned int nr_spread_over; |
ddc97297 | 423 | |
62160e3f | 424 | #ifdef CONFIG_FAIR_GROUP_SCHED |
6aa645ea IM |
425 | struct rq *rq; /* cpu runqueue to which this cfs_rq is attached */ |
426 | ||
41a2d6cf IM |
427 | /* |
428 | * leaf cfs_rqs are those that hold tasks (lowest schedulable entity in | |
6aa645ea IM |
429 | * a hierarchy). Non-leaf lrqs hold other higher schedulable entities |
430 | * (like users, containers etc.) | |
431 | * | |
432 | * leaf_cfs_rq_list ties together list of leaf cfs_rq's in a cpu. This | |
433 | * list is used during load balance. | |
434 | */ | |
41a2d6cf IM |
435 | struct list_head leaf_cfs_rq_list; |
436 | struct task_group *tg; /* group that "owns" this runqueue */ | |
c09595f6 PZ |
437 | |
438 | #ifdef CONFIG_SMP | |
c09595f6 | 439 | /* |
c8cba857 | 440 | * the part of load.weight contributed by tasks |
c09595f6 | 441 | */ |
c8cba857 | 442 | unsigned long task_weight; |
c09595f6 | 443 | |
c8cba857 PZ |
444 | /* |
445 | * h_load = weight * f(tg) | |
446 | * | |
447 | * Where f(tg) is the recursive weight fraction assigned to | |
448 | * this group. | |
449 | */ | |
450 | unsigned long h_load; | |
c09595f6 | 451 | |
c8cba857 PZ |
452 | /* |
453 | * this cpu's part of tg->shares | |
454 | */ | |
455 | unsigned long shares; | |
f1d239f7 PZ |
456 | |
457 | /* | |
458 | * load.weight at the time we set shares | |
459 | */ | |
460 | unsigned long rq_weight; | |
c09595f6 | 461 | #endif |
6aa645ea IM |
462 | #endif |
463 | }; | |
1da177e4 | 464 | |
6aa645ea IM |
465 | /* Real-Time classes' related field in a runqueue: */ |
466 | struct rt_rq { | |
467 | struct rt_prio_array active; | |
63489e45 | 468 | unsigned long rt_nr_running; |
052f1dc7 | 469 | #if defined CONFIG_SMP || defined CONFIG_RT_GROUP_SCHED |
6f505b16 PZ |
470 | int highest_prio; /* highest queued rt task prio */ |
471 | #endif | |
fa85ae24 | 472 | #ifdef CONFIG_SMP |
73fe6aae | 473 | unsigned long rt_nr_migratory; |
a22d7fc1 | 474 | int overloaded; |
fa85ae24 | 475 | #endif |
6f505b16 | 476 | int rt_throttled; |
fa85ae24 | 477 | u64 rt_time; |
ac086bc2 | 478 | u64 rt_runtime; |
ea736ed5 | 479 | /* Nests inside the rq lock: */ |
ac086bc2 | 480 | spinlock_t rt_runtime_lock; |
6f505b16 | 481 | |
052f1dc7 | 482 | #ifdef CONFIG_RT_GROUP_SCHED |
23b0fdfc PZ |
483 | unsigned long rt_nr_boosted; |
484 | ||
6f505b16 PZ |
485 | struct rq *rq; |
486 | struct list_head leaf_rt_rq_list; | |
487 | struct task_group *tg; | |
488 | struct sched_rt_entity *rt_se; | |
489 | #endif | |
6aa645ea IM |
490 | }; |
491 | ||
57d885fe GH |
492 | #ifdef CONFIG_SMP |
493 | ||
494 | /* | |
495 | * We add the notion of a root-domain which will be used to define per-domain | |
0eab9146 IM |
496 | * variables. Each exclusive cpuset essentially defines an island domain by |
497 | * fully partitioning the member cpus from any other cpuset. Whenever a new | |
57d885fe GH |
498 | * exclusive cpuset is created, we also create and attach a new root-domain |
499 | * object. | |
500 | * | |
57d885fe GH |
501 | */ |
502 | struct root_domain { | |
503 | atomic_t refcount; | |
c6c4927b RR |
504 | cpumask_var_t span; |
505 | cpumask_var_t online; | |
637f5085 | 506 | |
0eab9146 | 507 | /* |
637f5085 GH |
508 | * The "RT overload" flag: it gets set if a CPU has more than |
509 | * one runnable RT task. | |
510 | */ | |
c6c4927b | 511 | cpumask_var_t rto_mask; |
0eab9146 | 512 | atomic_t rto_count; |
6e0534f2 GH |
513 | #ifdef CONFIG_SMP |
514 | struct cpupri cpupri; | |
515 | #endif | |
7a09b1a2 VS |
516 | #if defined(CONFIG_SCHED_MC) || defined(CONFIG_SCHED_SMT) |
517 | /* | |
518 | * Preferred wake up cpu nominated by sched_mc balance that will be | |
519 | * used when most cpus are idle in the system indicating overall very | |
520 | * low system utilisation. Triggered at POWERSAVINGS_BALANCE_WAKEUP(2) | |
521 | */ | |
522 | unsigned int sched_mc_preferred_wakeup_cpu; | |
523 | #endif | |
57d885fe GH |
524 | }; |
525 | ||
dc938520 GH |
526 | /* |
527 | * By default the system creates a single root-domain with all cpus as | |
528 | * members (mimicking the global state we have today). | |
529 | */ | |
57d885fe GH |
530 | static struct root_domain def_root_domain; |
531 | ||
532 | #endif | |
533 | ||
1da177e4 LT |
534 | /* |
535 | * This is the main, per-CPU runqueue data structure. | |
536 | * | |
537 | * Locking rule: those places that want to lock multiple runqueues | |
538 | * (such as the load balancing or the thread migration code), lock | |
539 | * acquire operations must be ordered by ascending &runqueue. | |
540 | */ | |
70b97a7f | 541 | struct rq { |
d8016491 IM |
542 | /* runqueue lock: */ |
543 | spinlock_t lock; | |
1da177e4 LT |
544 | |
545 | /* | |
546 | * nr_running and cpu_load should be in the same cacheline because | |
547 | * remote CPUs use both these fields when doing load calculation. | |
548 | */ | |
549 | unsigned long nr_running; | |
6aa645ea IM |
550 | #define CPU_LOAD_IDX_MAX 5 |
551 | unsigned long cpu_load[CPU_LOAD_IDX_MAX]; | |
bdecea3a | 552 | unsigned char idle_at_tick; |
46cb4b7c | 553 | #ifdef CONFIG_NO_HZ |
15934a37 | 554 | unsigned long last_tick_seen; |
46cb4b7c SS |
555 | unsigned char in_nohz_recently; |
556 | #endif | |
d8016491 IM |
557 | /* capture load from *all* tasks on this cpu: */ |
558 | struct load_weight load; | |
6aa645ea IM |
559 | unsigned long nr_load_updates; |
560 | u64 nr_switches; | |
561 | ||
562 | struct cfs_rq cfs; | |
6f505b16 | 563 | struct rt_rq rt; |
6f505b16 | 564 | |
6aa645ea | 565 | #ifdef CONFIG_FAIR_GROUP_SCHED |
d8016491 IM |
566 | /* list of leaf cfs_rq on this cpu: */ |
567 | struct list_head leaf_cfs_rq_list; | |
052f1dc7 PZ |
568 | #endif |
569 | #ifdef CONFIG_RT_GROUP_SCHED | |
6f505b16 | 570 | struct list_head leaf_rt_rq_list; |
1da177e4 | 571 | #endif |
1da177e4 LT |
572 | |
573 | /* | |
574 | * This is part of a global counter where only the total sum | |
575 | * over all CPUs matters. A task can increase this counter on | |
576 | * one CPU and if it got migrated afterwards it may decrease | |
577 | * it on another CPU. Always updated under the runqueue lock: | |
578 | */ | |
579 | unsigned long nr_uninterruptible; | |
580 | ||
36c8b586 | 581 | struct task_struct *curr, *idle; |
c9819f45 | 582 | unsigned long next_balance; |
1da177e4 | 583 | struct mm_struct *prev_mm; |
6aa645ea | 584 | |
3e51f33f | 585 | u64 clock; |
6aa645ea | 586 | |
1da177e4 LT |
587 | atomic_t nr_iowait; |
588 | ||
589 | #ifdef CONFIG_SMP | |
0eab9146 | 590 | struct root_domain *rd; |
1da177e4 LT |
591 | struct sched_domain *sd; |
592 | ||
593 | /* For active balancing */ | |
594 | int active_balance; | |
595 | int push_cpu; | |
d8016491 IM |
596 | /* cpu of this runqueue: */ |
597 | int cpu; | |
1f11eb6a | 598 | int online; |
1da177e4 | 599 | |
a8a51d5e | 600 | unsigned long avg_load_per_task; |
1da177e4 | 601 | |
36c8b586 | 602 | struct task_struct *migration_thread; |
1da177e4 LT |
603 | struct list_head migration_queue; |
604 | #endif | |
605 | ||
8f4d37ec | 606 | #ifdef CONFIG_SCHED_HRTICK |
31656519 PZ |
607 | #ifdef CONFIG_SMP |
608 | int hrtick_csd_pending; | |
609 | struct call_single_data hrtick_csd; | |
610 | #endif | |
8f4d37ec PZ |
611 | struct hrtimer hrtick_timer; |
612 | #endif | |
613 | ||
1da177e4 LT |
614 | #ifdef CONFIG_SCHEDSTATS |
615 | /* latency stats */ | |
616 | struct sched_info rq_sched_info; | |
9c2c4802 KC |
617 | unsigned long long rq_cpu_time; |
618 | /* could above be rq->cfs_rq.exec_clock + rq->rt_rq.rt_runtime ? */ | |
1da177e4 LT |
619 | |
620 | /* sys_sched_yield() stats */ | |
480b9434 KC |
621 | unsigned int yld_exp_empty; |
622 | unsigned int yld_act_empty; | |
623 | unsigned int yld_both_empty; | |
624 | unsigned int yld_count; | |
1da177e4 LT |
625 | |
626 | /* schedule() stats */ | |
480b9434 KC |
627 | unsigned int sched_switch; |
628 | unsigned int sched_count; | |
629 | unsigned int sched_goidle; | |
1da177e4 LT |
630 | |
631 | /* try_to_wake_up() stats */ | |
480b9434 KC |
632 | unsigned int ttwu_count; |
633 | unsigned int ttwu_local; | |
b8efb561 IM |
634 | |
635 | /* BKL stats */ | |
480b9434 | 636 | unsigned int bkl_count; |
1da177e4 LT |
637 | #endif |
638 | }; | |
639 | ||
f34e3b61 | 640 | static DEFINE_PER_CPU_SHARED_ALIGNED(struct rq, runqueues); |
1da177e4 | 641 | |
15afe09b | 642 | static inline void check_preempt_curr(struct rq *rq, struct task_struct *p, int sync) |
dd41f596 | 643 | { |
15afe09b | 644 | rq->curr->sched_class->check_preempt_curr(rq, p, sync); |
dd41f596 IM |
645 | } |
646 | ||
0a2966b4 CL |
647 | static inline int cpu_of(struct rq *rq) |
648 | { | |
649 | #ifdef CONFIG_SMP | |
650 | return rq->cpu; | |
651 | #else | |
652 | return 0; | |
653 | #endif | |
654 | } | |
655 | ||
674311d5 NP |
656 | /* |
657 | * The domain tree (rq->sd) is protected by RCU's quiescent state transition. | |
1a20ff27 | 658 | * See detach_destroy_domains: synchronize_sched for details. |
674311d5 NP |
659 | * |
660 | * The domain tree of any CPU may only be accessed from within | |
661 | * preempt-disabled sections. | |
662 | */ | |
48f24c4d IM |
663 | #define for_each_domain(cpu, __sd) \ |
664 | for (__sd = rcu_dereference(cpu_rq(cpu)->sd); __sd; __sd = __sd->parent) | |
1da177e4 LT |
665 | |
666 | #define cpu_rq(cpu) (&per_cpu(runqueues, (cpu))) | |
667 | #define this_rq() (&__get_cpu_var(runqueues)) | |
668 | #define task_rq(p) cpu_rq(task_cpu(p)) | |
669 | #define cpu_curr(cpu) (cpu_rq(cpu)->curr) | |
670 | ||
aa9c4c0f | 671 | inline void update_rq_clock(struct rq *rq) |
3e51f33f PZ |
672 | { |
673 | rq->clock = sched_clock_cpu(cpu_of(rq)); | |
674 | } | |
675 | ||
bf5c91ba IM |
676 | /* |
677 | * Tunables that become constants when CONFIG_SCHED_DEBUG is off: | |
678 | */ | |
679 | #ifdef CONFIG_SCHED_DEBUG | |
680 | # define const_debug __read_mostly | |
681 | #else | |
682 | # define const_debug static const | |
683 | #endif | |
684 | ||
017730c1 IM |
685 | /** |
686 | * runqueue_is_locked | |
687 | * | |
688 | * Returns true if the current cpu runqueue is locked. | |
689 | * This interface allows printk to be called with the runqueue lock | |
690 | * held and know whether or not it is OK to wake up the klogd. | |
691 | */ | |
692 | int runqueue_is_locked(void) | |
693 | { | |
694 | int cpu = get_cpu(); | |
695 | struct rq *rq = cpu_rq(cpu); | |
696 | int ret; | |
697 | ||
698 | ret = spin_is_locked(&rq->lock); | |
699 | put_cpu(); | |
700 | return ret; | |
701 | } | |
702 | ||
bf5c91ba IM |
703 | /* |
704 | * Debugging: various feature bits | |
705 | */ | |
f00b45c1 PZ |
706 | |
707 | #define SCHED_FEAT(name, enabled) \ | |
708 | __SCHED_FEAT_##name , | |
709 | ||
bf5c91ba | 710 | enum { |
f00b45c1 | 711 | #include "sched_features.h" |
bf5c91ba IM |
712 | }; |
713 | ||
f00b45c1 PZ |
714 | #undef SCHED_FEAT |
715 | ||
716 | #define SCHED_FEAT(name, enabled) \ | |
717 | (1UL << __SCHED_FEAT_##name) * enabled | | |
718 | ||
bf5c91ba | 719 | const_debug unsigned int sysctl_sched_features = |
f00b45c1 PZ |
720 | #include "sched_features.h" |
721 | 0; | |
722 | ||
723 | #undef SCHED_FEAT | |
724 | ||
725 | #ifdef CONFIG_SCHED_DEBUG | |
726 | #define SCHED_FEAT(name, enabled) \ | |
727 | #name , | |
728 | ||
983ed7a6 | 729 | static __read_mostly char *sched_feat_names[] = { |
f00b45c1 PZ |
730 | #include "sched_features.h" |
731 | NULL | |
732 | }; | |
733 | ||
734 | #undef SCHED_FEAT | |
735 | ||
34f3a814 | 736 | static int sched_feat_show(struct seq_file *m, void *v) |
f00b45c1 | 737 | { |
f00b45c1 PZ |
738 | int i; |
739 | ||
740 | for (i = 0; sched_feat_names[i]; i++) { | |
34f3a814 LZ |
741 | if (!(sysctl_sched_features & (1UL << i))) |
742 | seq_puts(m, "NO_"); | |
743 | seq_printf(m, "%s ", sched_feat_names[i]); | |
f00b45c1 | 744 | } |
34f3a814 | 745 | seq_puts(m, "\n"); |
f00b45c1 | 746 | |
34f3a814 | 747 | return 0; |
f00b45c1 PZ |
748 | } |
749 | ||
750 | static ssize_t | |
751 | sched_feat_write(struct file *filp, const char __user *ubuf, | |
752 | size_t cnt, loff_t *ppos) | |
753 | { | |
754 | char buf[64]; | |
755 | char *cmp = buf; | |
756 | int neg = 0; | |
757 | int i; | |
758 | ||
759 | if (cnt > 63) | |
760 | cnt = 63; | |
761 | ||
762 | if (copy_from_user(&buf, ubuf, cnt)) | |
763 | return -EFAULT; | |
764 | ||
765 | buf[cnt] = 0; | |
766 | ||
c24b7c52 | 767 | if (strncmp(buf, "NO_", 3) == 0) { |
f00b45c1 PZ |
768 | neg = 1; |
769 | cmp += 3; | |
770 | } | |
771 | ||
772 | for (i = 0; sched_feat_names[i]; i++) { | |
773 | int len = strlen(sched_feat_names[i]); | |
774 | ||
775 | if (strncmp(cmp, sched_feat_names[i], len) == 0) { | |
776 | if (neg) | |
777 | sysctl_sched_features &= ~(1UL << i); | |
778 | else | |
779 | sysctl_sched_features |= (1UL << i); | |
780 | break; | |
781 | } | |
782 | } | |
783 | ||
784 | if (!sched_feat_names[i]) | |
785 | return -EINVAL; | |
786 | ||
787 | filp->f_pos += cnt; | |
788 | ||
789 | return cnt; | |
790 | } | |
791 | ||
34f3a814 LZ |
792 | static int sched_feat_open(struct inode *inode, struct file *filp) |
793 | { | |
794 | return single_open(filp, sched_feat_show, NULL); | |
795 | } | |
796 | ||
f00b45c1 | 797 | static struct file_operations sched_feat_fops = { |
34f3a814 LZ |
798 | .open = sched_feat_open, |
799 | .write = sched_feat_write, | |
800 | .read = seq_read, | |
801 | .llseek = seq_lseek, | |
802 | .release = single_release, | |
f00b45c1 PZ |
803 | }; |
804 | ||
805 | static __init int sched_init_debug(void) | |
806 | { | |
f00b45c1 PZ |
807 | debugfs_create_file("sched_features", 0644, NULL, NULL, |
808 | &sched_feat_fops); | |
809 | ||
810 | return 0; | |
811 | } | |
812 | late_initcall(sched_init_debug); | |
813 | ||
814 | #endif | |
815 | ||
816 | #define sched_feat(x) (sysctl_sched_features & (1UL << __SCHED_FEAT_##x)) | |
bf5c91ba | 817 | |
b82d9fdd PZ |
818 | /* |
819 | * Number of tasks to iterate in a single balance run. | |
820 | * Limited because this is done with IRQs disabled. | |
821 | */ | |
822 | const_debug unsigned int sysctl_sched_nr_migrate = 32; | |
823 | ||
2398f2c6 PZ |
824 | /* |
825 | * ratelimit for updating the group shares. | |
55cd5340 | 826 | * default: 0.25ms |
2398f2c6 | 827 | */ |
55cd5340 | 828 | unsigned int sysctl_sched_shares_ratelimit = 250000; |
2398f2c6 | 829 | |
ffda12a1 PZ |
830 | /* |
831 | * Inject some fuzzyness into changing the per-cpu group shares | |
832 | * this avoids remote rq-locks at the expense of fairness. | |
833 | * default: 4 | |
834 | */ | |
835 | unsigned int sysctl_sched_shares_thresh = 4; | |
836 | ||
fa85ae24 | 837 | /* |
9f0c1e56 | 838 | * period over which we measure -rt task cpu usage in us. |
fa85ae24 PZ |
839 | * default: 1s |
840 | */ | |
9f0c1e56 | 841 | unsigned int sysctl_sched_rt_period = 1000000; |
fa85ae24 | 842 | |
6892b75e IM |
843 | static __read_mostly int scheduler_running; |
844 | ||
9f0c1e56 PZ |
845 | /* |
846 | * part of the period that we allow rt tasks to run in us. | |
847 | * default: 0.95s | |
848 | */ | |
849 | int sysctl_sched_rt_runtime = 950000; | |
fa85ae24 | 850 | |
d0b27fa7 PZ |
851 | static inline u64 global_rt_period(void) |
852 | { | |
853 | return (u64)sysctl_sched_rt_period * NSEC_PER_USEC; | |
854 | } | |
855 | ||
856 | static inline u64 global_rt_runtime(void) | |
857 | { | |
e26873bb | 858 | if (sysctl_sched_rt_runtime < 0) |
d0b27fa7 PZ |
859 | return RUNTIME_INF; |
860 | ||
861 | return (u64)sysctl_sched_rt_runtime * NSEC_PER_USEC; | |
862 | } | |
fa85ae24 | 863 | |
1da177e4 | 864 | #ifndef prepare_arch_switch |
4866cde0 NP |
865 | # define prepare_arch_switch(next) do { } while (0) |
866 | #endif | |
867 | #ifndef finish_arch_switch | |
868 | # define finish_arch_switch(prev) do { } while (0) | |
869 | #endif | |
870 | ||
051a1d1a DA |
871 | static inline int task_current(struct rq *rq, struct task_struct *p) |
872 | { | |
873 | return rq->curr == p; | |
874 | } | |
875 | ||
4866cde0 | 876 | #ifndef __ARCH_WANT_UNLOCKED_CTXSW |
70b97a7f | 877 | static inline int task_running(struct rq *rq, struct task_struct *p) |
4866cde0 | 878 | { |
051a1d1a | 879 | return task_current(rq, p); |
4866cde0 NP |
880 | } |
881 | ||
70b97a7f | 882 | static inline void prepare_lock_switch(struct rq *rq, struct task_struct *next) |
4866cde0 NP |
883 | { |
884 | } | |
885 | ||
70b97a7f | 886 | static inline void finish_lock_switch(struct rq *rq, struct task_struct *prev) |
4866cde0 | 887 | { |
da04c035 IM |
888 | #ifdef CONFIG_DEBUG_SPINLOCK |
889 | /* this is a valid case when another task releases the spinlock */ | |
890 | rq->lock.owner = current; | |
891 | #endif | |
8a25d5de IM |
892 | /* |
893 | * If we are tracking spinlock dependencies then we have to | |
894 | * fix up the runqueue lock - which gets 'carried over' from | |
895 | * prev into current: | |
896 | */ | |
897 | spin_acquire(&rq->lock.dep_map, 0, 0, _THIS_IP_); | |
898 | ||
4866cde0 NP |
899 | spin_unlock_irq(&rq->lock); |
900 | } | |
901 | ||
902 | #else /* __ARCH_WANT_UNLOCKED_CTXSW */ | |
70b97a7f | 903 | static inline int task_running(struct rq *rq, struct task_struct *p) |
4866cde0 NP |
904 | { |
905 | #ifdef CONFIG_SMP | |
906 | return p->oncpu; | |
907 | #else | |
051a1d1a | 908 | return task_current(rq, p); |
4866cde0 NP |
909 | #endif |
910 | } | |
911 | ||
70b97a7f | 912 | static inline void prepare_lock_switch(struct rq *rq, struct task_struct *next) |
4866cde0 NP |
913 | { |
914 | #ifdef CONFIG_SMP | |
915 | /* | |
916 | * We can optimise this out completely for !SMP, because the | |
917 | * SMP rebalancing from interrupt is the only thing that cares | |
918 | * here. | |
919 | */ | |
920 | next->oncpu = 1; | |
921 | #endif | |
922 | #ifdef __ARCH_WANT_INTERRUPTS_ON_CTXSW | |
923 | spin_unlock_irq(&rq->lock); | |
924 | #else | |
925 | spin_unlock(&rq->lock); | |
926 | #endif | |
927 | } | |
928 | ||
70b97a7f | 929 | static inline void finish_lock_switch(struct rq *rq, struct task_struct *prev) |
4866cde0 NP |
930 | { |
931 | #ifdef CONFIG_SMP | |
932 | /* | |
933 | * After ->oncpu is cleared, the task can be moved to a different CPU. | |
934 | * We must ensure this doesn't happen until the switch is completely | |
935 | * finished. | |
936 | */ | |
937 | smp_wmb(); | |
938 | prev->oncpu = 0; | |
939 | #endif | |
940 | #ifndef __ARCH_WANT_INTERRUPTS_ON_CTXSW | |
941 | local_irq_enable(); | |
1da177e4 | 942 | #endif |
4866cde0 NP |
943 | } |
944 | #endif /* __ARCH_WANT_UNLOCKED_CTXSW */ | |
1da177e4 | 945 | |
b29739f9 IM |
946 | /* |
947 | * __task_rq_lock - lock the runqueue a given task resides on. | |
948 | * Must be called interrupts disabled. | |
949 | */ | |
70b97a7f | 950 | static inline struct rq *__task_rq_lock(struct task_struct *p) |
b29739f9 IM |
951 | __acquires(rq->lock) |
952 | { | |
3a5c359a AK |
953 | for (;;) { |
954 | struct rq *rq = task_rq(p); | |
955 | spin_lock(&rq->lock); | |
956 | if (likely(rq == task_rq(p))) | |
957 | return rq; | |
b29739f9 | 958 | spin_unlock(&rq->lock); |
b29739f9 | 959 | } |
b29739f9 IM |
960 | } |
961 | ||
1da177e4 LT |
962 | /* |
963 | * task_rq_lock - lock the runqueue a given task resides on and disable | |
41a2d6cf | 964 | * interrupts. Note the ordering: we can safely lookup the task_rq without |
1da177e4 LT |
965 | * explicitly disabling preemption. |
966 | */ | |
70b97a7f | 967 | static struct rq *task_rq_lock(struct task_struct *p, unsigned long *flags) |
1da177e4 LT |
968 | __acquires(rq->lock) |
969 | { | |
70b97a7f | 970 | struct rq *rq; |
1da177e4 | 971 | |
3a5c359a AK |
972 | for (;;) { |
973 | local_irq_save(*flags); | |
974 | rq = task_rq(p); | |
975 | spin_lock(&rq->lock); | |
976 | if (likely(rq == task_rq(p))) | |
977 | return rq; | |
1da177e4 | 978 | spin_unlock_irqrestore(&rq->lock, *flags); |
1da177e4 | 979 | } |
1da177e4 LT |
980 | } |
981 | ||
aa9c4c0f IM |
982 | void curr_rq_lock_irq_save(unsigned long *flags) |
983 | __acquires(rq->lock) | |
984 | { | |
985 | struct rq *rq; | |
986 | ||
987 | local_irq_save(*flags); | |
988 | rq = cpu_rq(smp_processor_id()); | |
989 | spin_lock(&rq->lock); | |
990 | } | |
991 | ||
992 | void curr_rq_unlock_irq_restore(unsigned long *flags) | |
993 | __releases(rq->lock) | |
994 | { | |
995 | struct rq *rq; | |
996 | ||
997 | rq = cpu_rq(smp_processor_id()); | |
998 | spin_unlock(&rq->lock); | |
999 | local_irq_restore(*flags); | |
1000 | } | |
1001 | ||
ad474cac ON |
1002 | void task_rq_unlock_wait(struct task_struct *p) |
1003 | { | |
1004 | struct rq *rq = task_rq(p); | |
1005 | ||
1006 | smp_mb(); /* spin-unlock-wait is not a full memory barrier */ | |
1007 | spin_unlock_wait(&rq->lock); | |
1008 | } | |
1009 | ||
a9957449 | 1010 | static void __task_rq_unlock(struct rq *rq) |
b29739f9 IM |
1011 | __releases(rq->lock) |
1012 | { | |
1013 | spin_unlock(&rq->lock); | |
1014 | } | |
1015 | ||
70b97a7f | 1016 | static inline void task_rq_unlock(struct rq *rq, unsigned long *flags) |
1da177e4 LT |
1017 | __releases(rq->lock) |
1018 | { | |
1019 | spin_unlock_irqrestore(&rq->lock, *flags); | |
1020 | } | |
1021 | ||
1da177e4 | 1022 | /* |
cc2a73b5 | 1023 | * this_rq_lock - lock this runqueue and disable interrupts. |
1da177e4 | 1024 | */ |
a9957449 | 1025 | static struct rq *this_rq_lock(void) |
1da177e4 LT |
1026 | __acquires(rq->lock) |
1027 | { | |
70b97a7f | 1028 | struct rq *rq; |
1da177e4 LT |
1029 | |
1030 | local_irq_disable(); | |
1031 | rq = this_rq(); | |
1032 | spin_lock(&rq->lock); | |
1033 | ||
1034 | return rq; | |
1035 | } | |
1036 | ||
8f4d37ec PZ |
1037 | #ifdef CONFIG_SCHED_HRTICK |
1038 | /* | |
1039 | * Use HR-timers to deliver accurate preemption points. | |
1040 | * | |
1041 | * Its all a bit involved since we cannot program an hrt while holding the | |
1042 | * rq->lock. So what we do is store a state in in rq->hrtick_* and ask for a | |
1043 | * reschedule event. | |
1044 | * | |
1045 | * When we get rescheduled we reprogram the hrtick_timer outside of the | |
1046 | * rq->lock. | |
1047 | */ | |
8f4d37ec PZ |
1048 | |
1049 | /* | |
1050 | * Use hrtick when: | |
1051 | * - enabled by features | |
1052 | * - hrtimer is actually high res | |
1053 | */ | |
1054 | static inline int hrtick_enabled(struct rq *rq) | |
1055 | { | |
1056 | if (!sched_feat(HRTICK)) | |
1057 | return 0; | |
ba42059f | 1058 | if (!cpu_active(cpu_of(rq))) |
b328ca18 | 1059 | return 0; |
8f4d37ec PZ |
1060 | return hrtimer_is_hres_active(&rq->hrtick_timer); |
1061 | } | |
1062 | ||
8f4d37ec PZ |
1063 | static void hrtick_clear(struct rq *rq) |
1064 | { | |
1065 | if (hrtimer_active(&rq->hrtick_timer)) | |
1066 | hrtimer_cancel(&rq->hrtick_timer); | |
1067 | } | |
1068 | ||
8f4d37ec PZ |
1069 | /* |
1070 | * High-resolution timer tick. | |
1071 | * Runs from hardirq context with interrupts disabled. | |
1072 | */ | |
1073 | static enum hrtimer_restart hrtick(struct hrtimer *timer) | |
1074 | { | |
1075 | struct rq *rq = container_of(timer, struct rq, hrtick_timer); | |
1076 | ||
1077 | WARN_ON_ONCE(cpu_of(rq) != smp_processor_id()); | |
1078 | ||
1079 | spin_lock(&rq->lock); | |
3e51f33f | 1080 | update_rq_clock(rq); |
8f4d37ec PZ |
1081 | rq->curr->sched_class->task_tick(rq, rq->curr, 1); |
1082 | spin_unlock(&rq->lock); | |
1083 | ||
1084 | return HRTIMER_NORESTART; | |
1085 | } | |
1086 | ||
95e904c7 | 1087 | #ifdef CONFIG_SMP |
31656519 PZ |
1088 | /* |
1089 | * called from hardirq (IPI) context | |
1090 | */ | |
1091 | static void __hrtick_start(void *arg) | |
b328ca18 | 1092 | { |
31656519 | 1093 | struct rq *rq = arg; |
b328ca18 | 1094 | |
31656519 PZ |
1095 | spin_lock(&rq->lock); |
1096 | hrtimer_restart(&rq->hrtick_timer); | |
1097 | rq->hrtick_csd_pending = 0; | |
1098 | spin_unlock(&rq->lock); | |
b328ca18 PZ |
1099 | } |
1100 | ||
31656519 PZ |
1101 | /* |
1102 | * Called to set the hrtick timer state. | |
1103 | * | |
1104 | * called with rq->lock held and irqs disabled | |
1105 | */ | |
1106 | static void hrtick_start(struct rq *rq, u64 delay) | |
b328ca18 | 1107 | { |
31656519 PZ |
1108 | struct hrtimer *timer = &rq->hrtick_timer; |
1109 | ktime_t time = ktime_add_ns(timer->base->get_time(), delay); | |
b328ca18 | 1110 | |
cc584b21 | 1111 | hrtimer_set_expires(timer, time); |
31656519 PZ |
1112 | |
1113 | if (rq == this_rq()) { | |
1114 | hrtimer_restart(timer); | |
1115 | } else if (!rq->hrtick_csd_pending) { | |
1116 | __smp_call_function_single(cpu_of(rq), &rq->hrtick_csd); | |
1117 | rq->hrtick_csd_pending = 1; | |
1118 | } | |
b328ca18 PZ |
1119 | } |
1120 | ||
1121 | static int | |
1122 | hotplug_hrtick(struct notifier_block *nfb, unsigned long action, void *hcpu) | |
1123 | { | |
1124 | int cpu = (int)(long)hcpu; | |
1125 | ||
1126 | switch (action) { | |
1127 | case CPU_UP_CANCELED: | |
1128 | case CPU_UP_CANCELED_FROZEN: | |
1129 | case CPU_DOWN_PREPARE: | |
1130 | case CPU_DOWN_PREPARE_FROZEN: | |
1131 | case CPU_DEAD: | |
1132 | case CPU_DEAD_FROZEN: | |
31656519 | 1133 | hrtick_clear(cpu_rq(cpu)); |
b328ca18 PZ |
1134 | return NOTIFY_OK; |
1135 | } | |
1136 | ||
1137 | return NOTIFY_DONE; | |
1138 | } | |
1139 | ||
fa748203 | 1140 | static __init void init_hrtick(void) |
b328ca18 PZ |
1141 | { |
1142 | hotcpu_notifier(hotplug_hrtick, 0); | |
1143 | } | |
31656519 PZ |
1144 | #else |
1145 | /* | |
1146 | * Called to set the hrtick timer state. | |
1147 | * | |
1148 | * called with rq->lock held and irqs disabled | |
1149 | */ | |
1150 | static void hrtick_start(struct rq *rq, u64 delay) | |
1151 | { | |
1152 | hrtimer_start(&rq->hrtick_timer, ns_to_ktime(delay), HRTIMER_MODE_REL); | |
1153 | } | |
b328ca18 | 1154 | |
006c75f1 | 1155 | static inline void init_hrtick(void) |
8f4d37ec | 1156 | { |
8f4d37ec | 1157 | } |
31656519 | 1158 | #endif /* CONFIG_SMP */ |
8f4d37ec | 1159 | |
31656519 | 1160 | static void init_rq_hrtick(struct rq *rq) |
8f4d37ec | 1161 | { |
31656519 PZ |
1162 | #ifdef CONFIG_SMP |
1163 | rq->hrtick_csd_pending = 0; | |
8f4d37ec | 1164 | |
31656519 PZ |
1165 | rq->hrtick_csd.flags = 0; |
1166 | rq->hrtick_csd.func = __hrtick_start; | |
1167 | rq->hrtick_csd.info = rq; | |
1168 | #endif | |
8f4d37ec | 1169 | |
31656519 PZ |
1170 | hrtimer_init(&rq->hrtick_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); |
1171 | rq->hrtick_timer.function = hrtick; | |
8f4d37ec | 1172 | } |
006c75f1 | 1173 | #else /* CONFIG_SCHED_HRTICK */ |
8f4d37ec PZ |
1174 | static inline void hrtick_clear(struct rq *rq) |
1175 | { | |
1176 | } | |
1177 | ||
8f4d37ec PZ |
1178 | static inline void init_rq_hrtick(struct rq *rq) |
1179 | { | |
1180 | } | |
1181 | ||
b328ca18 PZ |
1182 | static inline void init_hrtick(void) |
1183 | { | |
1184 | } | |
006c75f1 | 1185 | #endif /* CONFIG_SCHED_HRTICK */ |
8f4d37ec | 1186 | |
c24d20db IM |
1187 | /* |
1188 | * resched_task - mark a task 'to be rescheduled now'. | |
1189 | * | |
1190 | * On UP this means the setting of the need_resched flag, on SMP it | |
1191 | * might also involve a cross-CPU call to trigger the scheduler on | |
1192 | * the target CPU. | |
1193 | */ | |
1194 | #ifdef CONFIG_SMP | |
1195 | ||
1196 | #ifndef tsk_is_polling | |
1197 | #define tsk_is_polling(t) test_tsk_thread_flag(t, TIF_POLLING_NRFLAG) | |
1198 | #endif | |
1199 | ||
31656519 | 1200 | static void resched_task(struct task_struct *p) |
c24d20db IM |
1201 | { |
1202 | int cpu; | |
1203 | ||
1204 | assert_spin_locked(&task_rq(p)->lock); | |
1205 | ||
31656519 | 1206 | if (unlikely(test_tsk_thread_flag(p, TIF_NEED_RESCHED))) |
c24d20db IM |
1207 | return; |
1208 | ||
31656519 | 1209 | set_tsk_thread_flag(p, TIF_NEED_RESCHED); |
c24d20db IM |
1210 | |
1211 | cpu = task_cpu(p); | |
1212 | if (cpu == smp_processor_id()) | |
1213 | return; | |
1214 | ||
1215 | /* NEED_RESCHED must be visible before we test polling */ | |
1216 | smp_mb(); | |
1217 | if (!tsk_is_polling(p)) | |
1218 | smp_send_reschedule(cpu); | |
1219 | } | |
1220 | ||
1221 | static void resched_cpu(int cpu) | |
1222 | { | |
1223 | struct rq *rq = cpu_rq(cpu); | |
1224 | unsigned long flags; | |
1225 | ||
1226 | if (!spin_trylock_irqsave(&rq->lock, flags)) | |
1227 | return; | |
1228 | resched_task(cpu_curr(cpu)); | |
1229 | spin_unlock_irqrestore(&rq->lock, flags); | |
1230 | } | |
06d8308c TG |
1231 | |
1232 | #ifdef CONFIG_NO_HZ | |
1233 | /* | |
1234 | * When add_timer_on() enqueues a timer into the timer wheel of an | |
1235 | * idle CPU then this timer might expire before the next timer event | |
1236 | * which is scheduled to wake up that CPU. In case of a completely | |
1237 | * idle system the next event might even be infinite time into the | |
1238 | * future. wake_up_idle_cpu() ensures that the CPU is woken up and | |
1239 | * leaves the inner idle loop so the newly added timer is taken into | |
1240 | * account when the CPU goes back to idle and evaluates the timer | |
1241 | * wheel for the next timer event. | |
1242 | */ | |
1243 | void wake_up_idle_cpu(int cpu) | |
1244 | { | |
1245 | struct rq *rq = cpu_rq(cpu); | |
1246 | ||
1247 | if (cpu == smp_processor_id()) | |
1248 | return; | |
1249 | ||
1250 | /* | |
1251 | * This is safe, as this function is called with the timer | |
1252 | * wheel base lock of (cpu) held. When the CPU is on the way | |
1253 | * to idle and has not yet set rq->curr to idle then it will | |
1254 | * be serialized on the timer wheel base lock and take the new | |
1255 | * timer into account automatically. | |
1256 | */ | |
1257 | if (rq->curr != rq->idle) | |
1258 | return; | |
1259 | ||
1260 | /* | |
1261 | * We can set TIF_RESCHED on the idle task of the other CPU | |
1262 | * lockless. The worst case is that the other CPU runs the | |
1263 | * idle task through an additional NOOP schedule() | |
1264 | */ | |
1265 | set_tsk_thread_flag(rq->idle, TIF_NEED_RESCHED); | |
1266 | ||
1267 | /* NEED_RESCHED must be visible before we test polling */ | |
1268 | smp_mb(); | |
1269 | if (!tsk_is_polling(rq->idle)) | |
1270 | smp_send_reschedule(cpu); | |
1271 | } | |
6d6bc0ad | 1272 | #endif /* CONFIG_NO_HZ */ |
06d8308c | 1273 | |
6d6bc0ad | 1274 | #else /* !CONFIG_SMP */ |
31656519 | 1275 | static void resched_task(struct task_struct *p) |
c24d20db IM |
1276 | { |
1277 | assert_spin_locked(&task_rq(p)->lock); | |
31656519 | 1278 | set_tsk_need_resched(p); |
c24d20db | 1279 | } |
6d6bc0ad | 1280 | #endif /* CONFIG_SMP */ |
c24d20db | 1281 | |
45bf76df IM |
1282 | #if BITS_PER_LONG == 32 |
1283 | # define WMULT_CONST (~0UL) | |
1284 | #else | |
1285 | # define WMULT_CONST (1UL << 32) | |
1286 | #endif | |
1287 | ||
1288 | #define WMULT_SHIFT 32 | |
1289 | ||
194081eb IM |
1290 | /* |
1291 | * Shift right and round: | |
1292 | */ | |
cf2ab469 | 1293 | #define SRR(x, y) (((x) + (1UL << ((y) - 1))) >> (y)) |
194081eb | 1294 | |
a7be37ac PZ |
1295 | /* |
1296 | * delta *= weight / lw | |
1297 | */ | |
cb1c4fc9 | 1298 | static unsigned long |
45bf76df IM |
1299 | calc_delta_mine(unsigned long delta_exec, unsigned long weight, |
1300 | struct load_weight *lw) | |
1301 | { | |
1302 | u64 tmp; | |
1303 | ||
7a232e03 LJ |
1304 | if (!lw->inv_weight) { |
1305 | if (BITS_PER_LONG > 32 && unlikely(lw->weight >= WMULT_CONST)) | |
1306 | lw->inv_weight = 1; | |
1307 | else | |
1308 | lw->inv_weight = 1 + (WMULT_CONST-lw->weight/2) | |
1309 | / (lw->weight+1); | |
1310 | } | |
45bf76df IM |
1311 | |
1312 | tmp = (u64)delta_exec * weight; | |
1313 | /* | |
1314 | * Check whether we'd overflow the 64-bit multiplication: | |
1315 | */ | |
194081eb | 1316 | if (unlikely(tmp > WMULT_CONST)) |
cf2ab469 | 1317 | tmp = SRR(SRR(tmp, WMULT_SHIFT/2) * lw->inv_weight, |
194081eb IM |
1318 | WMULT_SHIFT/2); |
1319 | else | |
cf2ab469 | 1320 | tmp = SRR(tmp * lw->inv_weight, WMULT_SHIFT); |
45bf76df | 1321 | |
ecf691da | 1322 | return (unsigned long)min(tmp, (u64)(unsigned long)LONG_MAX); |
45bf76df IM |
1323 | } |
1324 | ||
1091985b | 1325 | static inline void update_load_add(struct load_weight *lw, unsigned long inc) |
45bf76df IM |
1326 | { |
1327 | lw->weight += inc; | |
e89996ae | 1328 | lw->inv_weight = 0; |
45bf76df IM |
1329 | } |
1330 | ||
1091985b | 1331 | static inline void update_load_sub(struct load_weight *lw, unsigned long dec) |
45bf76df IM |
1332 | { |
1333 | lw->weight -= dec; | |
e89996ae | 1334 | lw->inv_weight = 0; |
45bf76df IM |
1335 | } |
1336 | ||
2dd73a4f PW |
1337 | /* |
1338 | * To aid in avoiding the subversion of "niceness" due to uneven distribution | |
1339 | * of tasks with abnormal "nice" values across CPUs the contribution that | |
1340 | * each task makes to its run queue's load is weighted according to its | |
41a2d6cf | 1341 | * scheduling class and "nice" value. For SCHED_NORMAL tasks this is just a |
2dd73a4f PW |
1342 | * scaled version of the new time slice allocation that they receive on time |
1343 | * slice expiry etc. | |
1344 | */ | |
1345 | ||
cce7ade8 PZ |
1346 | #define WEIGHT_IDLEPRIO 3 |
1347 | #define WMULT_IDLEPRIO 1431655765 | |
dd41f596 IM |
1348 | |
1349 | /* | |
1350 | * Nice levels are multiplicative, with a gentle 10% change for every | |
1351 | * nice level changed. I.e. when a CPU-bound task goes from nice 0 to | |
1352 | * nice 1, it will get ~10% less CPU time than another CPU-bound task | |
1353 | * that remained on nice 0. | |
1354 | * | |
1355 | * The "10% effect" is relative and cumulative: from _any_ nice level, | |
1356 | * if you go up 1 level, it's -10% CPU usage, if you go down 1 level | |
f9153ee6 IM |
1357 | * it's +10% CPU usage. (to achieve that we use a multiplier of 1.25. |
1358 | * If a task goes up by ~10% and another task goes down by ~10% then | |
1359 | * the relative distance between them is ~25%.) | |
dd41f596 IM |
1360 | */ |
1361 | static const int prio_to_weight[40] = { | |
254753dc IM |
1362 | /* -20 */ 88761, 71755, 56483, 46273, 36291, |
1363 | /* -15 */ 29154, 23254, 18705, 14949, 11916, | |
1364 | /* -10 */ 9548, 7620, 6100, 4904, 3906, | |
1365 | /* -5 */ 3121, 2501, 1991, 1586, 1277, | |
1366 | /* 0 */ 1024, 820, 655, 526, 423, | |
1367 | /* 5 */ 335, 272, 215, 172, 137, | |
1368 | /* 10 */ 110, 87, 70, 56, 45, | |
1369 | /* 15 */ 36, 29, 23, 18, 15, | |
dd41f596 IM |
1370 | }; |
1371 | ||
5714d2de IM |
1372 | /* |
1373 | * Inverse (2^32/x) values of the prio_to_weight[] array, precalculated. | |
1374 | * | |
1375 | * In cases where the weight does not change often, we can use the | |
1376 | * precalculated inverse to speed up arithmetics by turning divisions | |
1377 | * into multiplications: | |
1378 | */ | |
dd41f596 | 1379 | static const u32 prio_to_wmult[40] = { |
254753dc IM |
1380 | /* -20 */ 48388, 59856, 76040, 92818, 118348, |
1381 | /* -15 */ 147320, 184698, 229616, 287308, 360437, | |
1382 | /* -10 */ 449829, 563644, 704093, 875809, 1099582, | |
1383 | /* -5 */ 1376151, 1717300, 2157191, 2708050, 3363326, | |
1384 | /* 0 */ 4194304, 5237765, 6557202, 8165337, 10153587, | |
1385 | /* 5 */ 12820798, 15790321, 19976592, 24970740, 31350126, | |
1386 | /* 10 */ 39045157, 49367440, 61356676, 76695844, 95443717, | |
1387 | /* 15 */ 119304647, 148102320, 186737708, 238609294, 286331153, | |
dd41f596 | 1388 | }; |
2dd73a4f | 1389 | |
dd41f596 IM |
1390 | static void activate_task(struct rq *rq, struct task_struct *p, int wakeup); |
1391 | ||
1392 | /* | |
1393 | * runqueue iterator, to support SMP load-balancing between different | |
1394 | * scheduling classes, without having to expose their internal data | |
1395 | * structures to the load-balancing proper: | |
1396 | */ | |
1397 | struct rq_iterator { | |
1398 | void *arg; | |
1399 | struct task_struct *(*start)(void *); | |
1400 | struct task_struct *(*next)(void *); | |
1401 | }; | |
1402 | ||
e1d1484f PW |
1403 | #ifdef CONFIG_SMP |
1404 | static unsigned long | |
1405 | balance_tasks(struct rq *this_rq, int this_cpu, struct rq *busiest, | |
1406 | unsigned long max_load_move, struct sched_domain *sd, | |
1407 | enum cpu_idle_type idle, int *all_pinned, | |
1408 | int *this_best_prio, struct rq_iterator *iterator); | |
1409 | ||
1410 | static int | |
1411 | iter_move_one_task(struct rq *this_rq, int this_cpu, struct rq *busiest, | |
1412 | struct sched_domain *sd, enum cpu_idle_type idle, | |
1413 | struct rq_iterator *iterator); | |
e1d1484f | 1414 | #endif |
dd41f596 | 1415 | |
d842de87 SV |
1416 | #ifdef CONFIG_CGROUP_CPUACCT |
1417 | static void cpuacct_charge(struct task_struct *tsk, u64 cputime); | |
1418 | #else | |
1419 | static inline void cpuacct_charge(struct task_struct *tsk, u64 cputime) {} | |
1420 | #endif | |
1421 | ||
18d95a28 PZ |
1422 | static inline void inc_cpu_load(struct rq *rq, unsigned long load) |
1423 | { | |
1424 | update_load_add(&rq->load, load); | |
1425 | } | |
1426 | ||
1427 | static inline void dec_cpu_load(struct rq *rq, unsigned long load) | |
1428 | { | |
1429 | update_load_sub(&rq->load, load); | |
1430 | } | |
1431 | ||
7940ca36 | 1432 | #if (defined(CONFIG_SMP) && defined(CONFIG_FAIR_GROUP_SCHED)) || defined(CONFIG_RT_GROUP_SCHED) |
eb755805 | 1433 | typedef int (*tg_visitor)(struct task_group *, void *); |
c09595f6 PZ |
1434 | |
1435 | /* | |
1436 | * Iterate the full tree, calling @down when first entering a node and @up when | |
1437 | * leaving it for the final time. | |
1438 | */ | |
eb755805 | 1439 | static int walk_tg_tree(tg_visitor down, tg_visitor up, void *data) |
c09595f6 PZ |
1440 | { |
1441 | struct task_group *parent, *child; | |
eb755805 | 1442 | int ret; |
c09595f6 PZ |
1443 | |
1444 | rcu_read_lock(); | |
1445 | parent = &root_task_group; | |
1446 | down: | |
eb755805 PZ |
1447 | ret = (*down)(parent, data); |
1448 | if (ret) | |
1449 | goto out_unlock; | |
c09595f6 PZ |
1450 | list_for_each_entry_rcu(child, &parent->children, siblings) { |
1451 | parent = child; | |
1452 | goto down; | |
1453 | ||
1454 | up: | |
1455 | continue; | |
1456 | } | |
eb755805 PZ |
1457 | ret = (*up)(parent, data); |
1458 | if (ret) | |
1459 | goto out_unlock; | |
c09595f6 PZ |
1460 | |
1461 | child = parent; | |
1462 | parent = parent->parent; | |
1463 | if (parent) | |
1464 | goto up; | |
eb755805 | 1465 | out_unlock: |
c09595f6 | 1466 | rcu_read_unlock(); |
eb755805 PZ |
1467 | |
1468 | return ret; | |
c09595f6 PZ |
1469 | } |
1470 | ||
eb755805 PZ |
1471 | static int tg_nop(struct task_group *tg, void *data) |
1472 | { | |
1473 | return 0; | |
c09595f6 | 1474 | } |
eb755805 PZ |
1475 | #endif |
1476 | ||
1477 | #ifdef CONFIG_SMP | |
1478 | static unsigned long source_load(int cpu, int type); | |
1479 | static unsigned long target_load(int cpu, int type); | |
1480 | static int task_hot(struct task_struct *p, u64 now, struct sched_domain *sd); | |
1481 | ||
1482 | static unsigned long cpu_avg_load_per_task(int cpu) | |
1483 | { | |
1484 | struct rq *rq = cpu_rq(cpu); | |
af6d596f | 1485 | unsigned long nr_running = ACCESS_ONCE(rq->nr_running); |
eb755805 | 1486 | |
4cd42620 SR |
1487 | if (nr_running) |
1488 | rq->avg_load_per_task = rq->load.weight / nr_running; | |
a2d47777 BS |
1489 | else |
1490 | rq->avg_load_per_task = 0; | |
eb755805 PZ |
1491 | |
1492 | return rq->avg_load_per_task; | |
1493 | } | |
1494 | ||
1495 | #ifdef CONFIG_FAIR_GROUP_SCHED | |
c09595f6 | 1496 | |
c09595f6 PZ |
1497 | static void __set_se_shares(struct sched_entity *se, unsigned long shares); |
1498 | ||
1499 | /* | |
1500 | * Calculate and set the cpu's group shares. | |
1501 | */ | |
1502 | static void | |
ffda12a1 PZ |
1503 | update_group_shares_cpu(struct task_group *tg, int cpu, |
1504 | unsigned long sd_shares, unsigned long sd_rq_weight) | |
18d95a28 | 1505 | { |
c09595f6 PZ |
1506 | unsigned long shares; |
1507 | unsigned long rq_weight; | |
1508 | ||
c8cba857 | 1509 | if (!tg->se[cpu]) |
c09595f6 PZ |
1510 | return; |
1511 | ||
ec4e0e2f | 1512 | rq_weight = tg->cfs_rq[cpu]->rq_weight; |
c8cba857 | 1513 | |
c09595f6 PZ |
1514 | /* |
1515 | * \Sum shares * rq_weight | |
1516 | * shares = ----------------------- | |
1517 | * \Sum rq_weight | |
1518 | * | |
1519 | */ | |
ec4e0e2f | 1520 | shares = (sd_shares * rq_weight) / sd_rq_weight; |
ffda12a1 | 1521 | shares = clamp_t(unsigned long, shares, MIN_SHARES, MAX_SHARES); |
c09595f6 | 1522 | |
ffda12a1 PZ |
1523 | if (abs(shares - tg->se[cpu]->load.weight) > |
1524 | sysctl_sched_shares_thresh) { | |
1525 | struct rq *rq = cpu_rq(cpu); | |
1526 | unsigned long flags; | |
c09595f6 | 1527 | |
ffda12a1 | 1528 | spin_lock_irqsave(&rq->lock, flags); |
ec4e0e2f | 1529 | tg->cfs_rq[cpu]->shares = shares; |
c09595f6 | 1530 | |
ffda12a1 PZ |
1531 | __set_se_shares(tg->se[cpu], shares); |
1532 | spin_unlock_irqrestore(&rq->lock, flags); | |
1533 | } | |
18d95a28 | 1534 | } |
c09595f6 PZ |
1535 | |
1536 | /* | |
c8cba857 PZ |
1537 | * Re-compute the task group their per cpu shares over the given domain. |
1538 | * This needs to be done in a bottom-up fashion because the rq weight of a | |
1539 | * parent group depends on the shares of its child groups. | |
c09595f6 | 1540 | */ |
eb755805 | 1541 | static int tg_shares_up(struct task_group *tg, void *data) |
c09595f6 | 1542 | { |
ec4e0e2f | 1543 | unsigned long weight, rq_weight = 0; |
c8cba857 | 1544 | unsigned long shares = 0; |
eb755805 | 1545 | struct sched_domain *sd = data; |
c8cba857 | 1546 | int i; |
c09595f6 | 1547 | |
758b2cdc | 1548 | for_each_cpu(i, sched_domain_span(sd)) { |
ec4e0e2f KC |
1549 | /* |
1550 | * If there are currently no tasks on the cpu pretend there | |
1551 | * is one of average load so that when a new task gets to | |
1552 | * run here it will not get delayed by group starvation. | |
1553 | */ | |
1554 | weight = tg->cfs_rq[i]->load.weight; | |
1555 | if (!weight) | |
1556 | weight = NICE_0_LOAD; | |
1557 | ||
1558 | tg->cfs_rq[i]->rq_weight = weight; | |
1559 | rq_weight += weight; | |
c8cba857 | 1560 | shares += tg->cfs_rq[i]->shares; |
c09595f6 | 1561 | } |
c09595f6 | 1562 | |
c8cba857 PZ |
1563 | if ((!shares && rq_weight) || shares > tg->shares) |
1564 | shares = tg->shares; | |
1565 | ||
1566 | if (!sd->parent || !(sd->parent->flags & SD_LOAD_BALANCE)) | |
1567 | shares = tg->shares; | |
c09595f6 | 1568 | |
758b2cdc | 1569 | for_each_cpu(i, sched_domain_span(sd)) |
ffda12a1 | 1570 | update_group_shares_cpu(tg, i, shares, rq_weight); |
eb755805 PZ |
1571 | |
1572 | return 0; | |
c09595f6 PZ |
1573 | } |
1574 | ||
1575 | /* | |
c8cba857 PZ |
1576 | * Compute the cpu's hierarchical load factor for each task group. |
1577 | * This needs to be done in a top-down fashion because the load of a child | |
1578 | * group is a fraction of its parents load. | |
c09595f6 | 1579 | */ |
eb755805 | 1580 | static int tg_load_down(struct task_group *tg, void *data) |
c09595f6 | 1581 | { |
c8cba857 | 1582 | unsigned long load; |
eb755805 | 1583 | long cpu = (long)data; |
c09595f6 | 1584 | |
c8cba857 PZ |
1585 | if (!tg->parent) { |
1586 | load = cpu_rq(cpu)->load.weight; | |
1587 | } else { | |
1588 | load = tg->parent->cfs_rq[cpu]->h_load; | |
1589 | load *= tg->cfs_rq[cpu]->shares; | |
1590 | load /= tg->parent->cfs_rq[cpu]->load.weight + 1; | |
1591 | } | |
c09595f6 | 1592 | |
c8cba857 | 1593 | tg->cfs_rq[cpu]->h_load = load; |
c09595f6 | 1594 | |
eb755805 | 1595 | return 0; |
c09595f6 PZ |
1596 | } |
1597 | ||
c8cba857 | 1598 | static void update_shares(struct sched_domain *sd) |
4d8d595d | 1599 | { |
2398f2c6 PZ |
1600 | u64 now = cpu_clock(raw_smp_processor_id()); |
1601 | s64 elapsed = now - sd->last_update; | |
1602 | ||
1603 | if (elapsed >= (s64)(u64)sysctl_sched_shares_ratelimit) { | |
1604 | sd->last_update = now; | |
eb755805 | 1605 | walk_tg_tree(tg_nop, tg_shares_up, sd); |
2398f2c6 | 1606 | } |
4d8d595d PZ |
1607 | } |
1608 | ||
3e5459b4 PZ |
1609 | static void update_shares_locked(struct rq *rq, struct sched_domain *sd) |
1610 | { | |
1611 | spin_unlock(&rq->lock); | |
1612 | update_shares(sd); | |
1613 | spin_lock(&rq->lock); | |
1614 | } | |
1615 | ||
eb755805 | 1616 | static void update_h_load(long cpu) |
c09595f6 | 1617 | { |
eb755805 | 1618 | walk_tg_tree(tg_load_down, tg_nop, (void *)cpu); |
c09595f6 PZ |
1619 | } |
1620 | ||
c09595f6 PZ |
1621 | #else |
1622 | ||
c8cba857 | 1623 | static inline void update_shares(struct sched_domain *sd) |
4d8d595d PZ |
1624 | { |
1625 | } | |
1626 | ||
3e5459b4 PZ |
1627 | static inline void update_shares_locked(struct rq *rq, struct sched_domain *sd) |
1628 | { | |
1629 | } | |
1630 | ||
18d95a28 PZ |
1631 | #endif |
1632 | ||
70574a99 AD |
1633 | /* |
1634 | * double_lock_balance - lock the busiest runqueue, this_rq is locked already. | |
1635 | */ | |
1636 | static int double_lock_balance(struct rq *this_rq, struct rq *busiest) | |
1637 | __releases(this_rq->lock) | |
1638 | __acquires(busiest->lock) | |
1639 | __acquires(this_rq->lock) | |
1640 | { | |
1641 | int ret = 0; | |
1642 | ||
1643 | if (unlikely(!irqs_disabled())) { | |
1644 | /* printk() doesn't work good under rq->lock */ | |
1645 | spin_unlock(&this_rq->lock); | |
1646 | BUG_ON(1); | |
1647 | } | |
1648 | if (unlikely(!spin_trylock(&busiest->lock))) { | |
1649 | if (busiest < this_rq) { | |
1650 | spin_unlock(&this_rq->lock); | |
1651 | spin_lock(&busiest->lock); | |
1652 | spin_lock_nested(&this_rq->lock, SINGLE_DEPTH_NESTING); | |
1653 | ret = 1; | |
1654 | } else | |
1655 | spin_lock_nested(&busiest->lock, SINGLE_DEPTH_NESTING); | |
1656 | } | |
1657 | return ret; | |
1658 | } | |
1659 | ||
1660 | static inline void double_unlock_balance(struct rq *this_rq, struct rq *busiest) | |
1661 | __releases(busiest->lock) | |
1662 | { | |
1663 | spin_unlock(&busiest->lock); | |
1664 | lock_set_subclass(&this_rq->lock.dep_map, 0, _RET_IP_); | |
1665 | } | |
18d95a28 PZ |
1666 | #endif |
1667 | ||
30432094 | 1668 | #ifdef CONFIG_FAIR_GROUP_SCHED |
34e83e85 IM |
1669 | static void cfs_rq_set_shares(struct cfs_rq *cfs_rq, unsigned long shares) |
1670 | { | |
30432094 | 1671 | #ifdef CONFIG_SMP |
34e83e85 IM |
1672 | cfs_rq->shares = shares; |
1673 | #endif | |
1674 | } | |
30432094 | 1675 | #endif |
e7693a36 | 1676 | |
dd41f596 | 1677 | #include "sched_stats.h" |
dd41f596 | 1678 | #include "sched_idletask.c" |
5522d5d5 IM |
1679 | #include "sched_fair.c" |
1680 | #include "sched_rt.c" | |
dd41f596 IM |
1681 | #ifdef CONFIG_SCHED_DEBUG |
1682 | # include "sched_debug.c" | |
1683 | #endif | |
1684 | ||
1685 | #define sched_class_highest (&rt_sched_class) | |
1f11eb6a GH |
1686 | #define for_each_class(class) \ |
1687 | for (class = sched_class_highest; class; class = class->next) | |
dd41f596 | 1688 | |
c09595f6 | 1689 | static void inc_nr_running(struct rq *rq) |
9c217245 IM |
1690 | { |
1691 | rq->nr_running++; | |
9c217245 IM |
1692 | } |
1693 | ||
c09595f6 | 1694 | static void dec_nr_running(struct rq *rq) |
9c217245 IM |
1695 | { |
1696 | rq->nr_running--; | |
9c217245 IM |
1697 | } |
1698 | ||
45bf76df IM |
1699 | static void set_load_weight(struct task_struct *p) |
1700 | { | |
1701 | if (task_has_rt_policy(p)) { | |
dd41f596 IM |
1702 | p->se.load.weight = prio_to_weight[0] * 2; |
1703 | p->se.load.inv_weight = prio_to_wmult[0] >> 1; | |
1704 | return; | |
1705 | } | |
45bf76df | 1706 | |
dd41f596 IM |
1707 | /* |
1708 | * SCHED_IDLE tasks get minimal weight: | |
1709 | */ | |
1710 | if (p->policy == SCHED_IDLE) { | |
1711 | p->se.load.weight = WEIGHT_IDLEPRIO; | |
1712 | p->se.load.inv_weight = WMULT_IDLEPRIO; | |
1713 | return; | |
1714 | } | |
71f8bd46 | 1715 | |
dd41f596 IM |
1716 | p->se.load.weight = prio_to_weight[p->static_prio - MAX_RT_PRIO]; |
1717 | p->se.load.inv_weight = prio_to_wmult[p->static_prio - MAX_RT_PRIO]; | |
71f8bd46 IM |
1718 | } |
1719 | ||
2087a1ad GH |
1720 | static void update_avg(u64 *avg, u64 sample) |
1721 | { | |
1722 | s64 diff = sample - *avg; | |
1723 | *avg += diff >> 3; | |
1724 | } | |
1725 | ||
8159f87e | 1726 | static void enqueue_task(struct rq *rq, struct task_struct *p, int wakeup) |
71f8bd46 | 1727 | { |
dd41f596 | 1728 | sched_info_queued(p); |
fd390f6a | 1729 | p->sched_class->enqueue_task(rq, p, wakeup); |
dd41f596 | 1730 | p->se.on_rq = 1; |
71f8bd46 IM |
1731 | } |
1732 | ||
69be72c1 | 1733 | static void dequeue_task(struct rq *rq, struct task_struct *p, int sleep) |
71f8bd46 | 1734 | { |
2087a1ad GH |
1735 | if (sleep && p->se.last_wakeup) { |
1736 | update_avg(&p->se.avg_overlap, | |
1737 | p->se.sum_exec_runtime - p->se.last_wakeup); | |
1738 | p->se.last_wakeup = 0; | |
1739 | } | |
1740 | ||
46ac22ba | 1741 | sched_info_dequeued(p); |
f02231e5 | 1742 | p->sched_class->dequeue_task(rq, p, sleep); |
dd41f596 | 1743 | p->se.on_rq = 0; |
71f8bd46 IM |
1744 | } |
1745 | ||
14531189 | 1746 | /* |
dd41f596 | 1747 | * __normal_prio - return the priority that is based on the static prio |
14531189 | 1748 | */ |
14531189 IM |
1749 | static inline int __normal_prio(struct task_struct *p) |
1750 | { | |
dd41f596 | 1751 | return p->static_prio; |
14531189 IM |
1752 | } |
1753 | ||
b29739f9 IM |
1754 | /* |
1755 | * Calculate the expected normal priority: i.e. priority | |
1756 | * without taking RT-inheritance into account. Might be | |
1757 | * boosted by interactivity modifiers. Changes upon fork, | |
1758 | * setprio syscalls, and whenever the interactivity | |
1759 | * estimator recalculates. | |
1760 | */ | |
36c8b586 | 1761 | static inline int normal_prio(struct task_struct *p) |
b29739f9 IM |
1762 | { |
1763 | int prio; | |
1764 | ||
e05606d3 | 1765 | if (task_has_rt_policy(p)) |
b29739f9 IM |
1766 | prio = MAX_RT_PRIO-1 - p->rt_priority; |
1767 | else | |
1768 | prio = __normal_prio(p); | |
1769 | return prio; | |
1770 | } | |
1771 | ||
1772 | /* | |
1773 | * Calculate the current priority, i.e. the priority | |
1774 | * taken into account by the scheduler. This value might | |
1775 | * be boosted by RT tasks, or might be boosted by | |
1776 | * interactivity modifiers. Will be RT if the task got | |
1777 | * RT-boosted. If not then it returns p->normal_prio. | |
1778 | */ | |
36c8b586 | 1779 | static int effective_prio(struct task_struct *p) |
b29739f9 IM |
1780 | { |
1781 | p->normal_prio = normal_prio(p); | |
1782 | /* | |
1783 | * If we are RT tasks or we were boosted to RT priority, | |
1784 | * keep the priority unchanged. Otherwise, update priority | |
1785 | * to the normal priority: | |
1786 | */ | |
1787 | if (!rt_prio(p->prio)) | |
1788 | return p->normal_prio; | |
1789 | return p->prio; | |
1790 | } | |
1791 | ||
1da177e4 | 1792 | /* |
dd41f596 | 1793 | * activate_task - move a task to the runqueue. |
1da177e4 | 1794 | */ |
dd41f596 | 1795 | static void activate_task(struct rq *rq, struct task_struct *p, int wakeup) |
1da177e4 | 1796 | { |
d9514f6c | 1797 | if (task_contributes_to_load(p)) |
dd41f596 | 1798 | rq->nr_uninterruptible--; |
1da177e4 | 1799 | |
8159f87e | 1800 | enqueue_task(rq, p, wakeup); |
c09595f6 | 1801 | inc_nr_running(rq); |
1da177e4 LT |
1802 | } |
1803 | ||
1da177e4 LT |
1804 | /* |
1805 | * deactivate_task - remove a task from the runqueue. | |
1806 | */ | |
2e1cb74a | 1807 | static void deactivate_task(struct rq *rq, struct task_struct *p, int sleep) |
1da177e4 | 1808 | { |
d9514f6c | 1809 | if (task_contributes_to_load(p)) |
dd41f596 IM |
1810 | rq->nr_uninterruptible++; |
1811 | ||
69be72c1 | 1812 | dequeue_task(rq, p, sleep); |
c09595f6 | 1813 | dec_nr_running(rq); |
1da177e4 LT |
1814 | } |
1815 | ||
1da177e4 LT |
1816 | /** |
1817 | * task_curr - is this task currently executing on a CPU? | |
1818 | * @p: the task in question. | |
1819 | */ | |
36c8b586 | 1820 | inline int task_curr(const struct task_struct *p) |
1da177e4 LT |
1821 | { |
1822 | return cpu_curr(task_cpu(p)) == p; | |
1823 | } | |
1824 | ||
dd41f596 IM |
1825 | static inline void __set_task_cpu(struct task_struct *p, unsigned int cpu) |
1826 | { | |
6f505b16 | 1827 | set_task_rq(p, cpu); |
dd41f596 | 1828 | #ifdef CONFIG_SMP |
ce96b5ac DA |
1829 | /* |
1830 | * After ->cpu is set up to a new value, task_rq_lock(p, ...) can be | |
1831 | * successfuly executed on another CPU. We must ensure that updates of | |
1832 | * per-task data have been completed by this moment. | |
1833 | */ | |
1834 | smp_wmb(); | |
dd41f596 | 1835 | task_thread_info(p)->cpu = cpu; |
dd41f596 | 1836 | #endif |
2dd73a4f PW |
1837 | } |
1838 | ||
cb469845 SR |
1839 | static inline void check_class_changed(struct rq *rq, struct task_struct *p, |
1840 | const struct sched_class *prev_class, | |
1841 | int oldprio, int running) | |
1842 | { | |
1843 | if (prev_class != p->sched_class) { | |
1844 | if (prev_class->switched_from) | |
1845 | prev_class->switched_from(rq, p, running); | |
1846 | p->sched_class->switched_to(rq, p, running); | |
1847 | } else | |
1848 | p->sched_class->prio_changed(rq, p, oldprio, running); | |
1849 | } | |
1850 | ||
1da177e4 | 1851 | #ifdef CONFIG_SMP |
c65cc870 | 1852 | |
e958b360 TG |
1853 | /* Used instead of source_load when we know the type == 0 */ |
1854 | static unsigned long weighted_cpuload(const int cpu) | |
1855 | { | |
1856 | return cpu_rq(cpu)->load.weight; | |
1857 | } | |
1858 | ||
cc367732 IM |
1859 | /* |
1860 | * Is this task likely cache-hot: | |
1861 | */ | |
e7693a36 | 1862 | static int |
cc367732 IM |
1863 | task_hot(struct task_struct *p, u64 now, struct sched_domain *sd) |
1864 | { | |
1865 | s64 delta; | |
1866 | ||
f540a608 IM |
1867 | /* |
1868 | * Buddy candidates are cache hot: | |
1869 | */ | |
4793241b PZ |
1870 | if (sched_feat(CACHE_HOT_BUDDY) && |
1871 | (&p->se == cfs_rq_of(&p->se)->next || | |
1872 | &p->se == cfs_rq_of(&p->se)->last)) | |
f540a608 IM |
1873 | return 1; |
1874 | ||
cc367732 IM |
1875 | if (p->sched_class != &fair_sched_class) |
1876 | return 0; | |
1877 | ||
6bc1665b IM |
1878 | if (sysctl_sched_migration_cost == -1) |
1879 | return 1; | |
1880 | if (sysctl_sched_migration_cost == 0) | |
1881 | return 0; | |
1882 | ||
cc367732 IM |
1883 | delta = now - p->se.exec_start; |
1884 | ||
1885 | return delta < (s64)sysctl_sched_migration_cost; | |
1886 | } | |
1887 | ||
1888 | ||
dd41f596 | 1889 | void set_task_cpu(struct task_struct *p, unsigned int new_cpu) |
c65cc870 | 1890 | { |
dd41f596 IM |
1891 | int old_cpu = task_cpu(p); |
1892 | struct rq *old_rq = cpu_rq(old_cpu), *new_rq = cpu_rq(new_cpu); | |
2830cf8c SV |
1893 | struct cfs_rq *old_cfsrq = task_cfs_rq(p), |
1894 | *new_cfsrq = cpu_cfs_rq(old_cfsrq, new_cpu); | |
bbdba7c0 | 1895 | u64 clock_offset; |
dd41f596 IM |
1896 | |
1897 | clock_offset = old_rq->clock - new_rq->clock; | |
6cfb0d5d | 1898 | |
cbc34ed1 PZ |
1899 | trace_sched_migrate_task(p, task_cpu(p), new_cpu); |
1900 | ||
6cfb0d5d IM |
1901 | #ifdef CONFIG_SCHEDSTATS |
1902 | if (p->se.wait_start) | |
1903 | p->se.wait_start -= clock_offset; | |
dd41f596 IM |
1904 | if (p->se.sleep_start) |
1905 | p->se.sleep_start -= clock_offset; | |
1906 | if (p->se.block_start) | |
1907 | p->se.block_start -= clock_offset; | |
6c594c21 | 1908 | #endif |
cc367732 | 1909 | if (old_cpu != new_cpu) { |
6c594c21 IM |
1910 | p->se.nr_migrations++; |
1911 | #ifdef CONFIG_SCHEDSTATS | |
cc367732 IM |
1912 | if (task_hot(p, old_rq->clock, NULL)) |
1913 | schedstat_inc(p, se.nr_forced2_migrations); | |
6cfb0d5d | 1914 | #endif |
6c594c21 | 1915 | } |
2830cf8c SV |
1916 | p->se.vruntime -= old_cfsrq->min_vruntime - |
1917 | new_cfsrq->min_vruntime; | |
dd41f596 IM |
1918 | |
1919 | __set_task_cpu(p, new_cpu); | |
c65cc870 IM |
1920 | } |
1921 | ||
70b97a7f | 1922 | struct migration_req { |
1da177e4 | 1923 | struct list_head list; |
1da177e4 | 1924 | |
36c8b586 | 1925 | struct task_struct *task; |
1da177e4 LT |
1926 | int dest_cpu; |
1927 | ||
1da177e4 | 1928 | struct completion done; |
70b97a7f | 1929 | }; |
1da177e4 LT |
1930 | |
1931 | /* | |
1932 | * The task's runqueue lock must be held. | |
1933 | * Returns true if you have to wait for migration thread. | |
1934 | */ | |
36c8b586 | 1935 | static int |
70b97a7f | 1936 | migrate_task(struct task_struct *p, int dest_cpu, struct migration_req *req) |
1da177e4 | 1937 | { |
70b97a7f | 1938 | struct rq *rq = task_rq(p); |
1da177e4 LT |
1939 | |
1940 | /* | |
1941 | * If the task is not on a runqueue (and not running), then | |
1942 | * it is sufficient to simply update the task's cpu field. | |
1943 | */ | |
dd41f596 | 1944 | if (!p->se.on_rq && !task_running(rq, p)) { |
1da177e4 LT |
1945 | set_task_cpu(p, dest_cpu); |
1946 | return 0; | |
1947 | } | |
1948 | ||
1949 | init_completion(&req->done); | |
1da177e4 LT |
1950 | req->task = p; |
1951 | req->dest_cpu = dest_cpu; | |
1952 | list_add(&req->list, &rq->migration_queue); | |
48f24c4d | 1953 | |
1da177e4 LT |
1954 | return 1; |
1955 | } | |
1956 | ||
1957 | /* | |
1958 | * wait_task_inactive - wait for a thread to unschedule. | |
1959 | * | |
85ba2d86 RM |
1960 | * If @match_state is nonzero, it's the @p->state value just checked and |
1961 | * not expected to change. If it changes, i.e. @p might have woken up, | |
1962 | * then return zero. When we succeed in waiting for @p to be off its CPU, | |
1963 | * we return a positive number (its total switch count). If a second call | |
1964 | * a short while later returns the same number, the caller can be sure that | |
1965 | * @p has remained unscheduled the whole time. | |
1966 | * | |
1da177e4 LT |
1967 | * The caller must ensure that the task *will* unschedule sometime soon, |
1968 | * else this function might spin for a *long* time. This function can't | |
1969 | * be called with interrupts off, or it may introduce deadlock with | |
1970 | * smp_call_function() if an IPI is sent by the same process we are | |
1971 | * waiting to become inactive. | |
1972 | */ | |
85ba2d86 | 1973 | unsigned long wait_task_inactive(struct task_struct *p, long match_state) |
1da177e4 LT |
1974 | { |
1975 | unsigned long flags; | |
dd41f596 | 1976 | int running, on_rq; |
85ba2d86 | 1977 | unsigned long ncsw; |
70b97a7f | 1978 | struct rq *rq; |
1da177e4 | 1979 | |
3a5c359a AK |
1980 | for (;;) { |
1981 | /* | |
1982 | * We do the initial early heuristics without holding | |
1983 | * any task-queue locks at all. We'll only try to get | |
1984 | * the runqueue lock when things look like they will | |
1985 | * work out! | |
1986 | */ | |
1987 | rq = task_rq(p); | |
fa490cfd | 1988 | |
3a5c359a AK |
1989 | /* |
1990 | * If the task is actively running on another CPU | |
1991 | * still, just relax and busy-wait without holding | |
1992 | * any locks. | |
1993 | * | |
1994 | * NOTE! Since we don't hold any locks, it's not | |
1995 | * even sure that "rq" stays as the right runqueue! | |
1996 | * But we don't care, since "task_running()" will | |
1997 | * return false if the runqueue has changed and p | |
1998 | * is actually now running somewhere else! | |
1999 | */ | |
85ba2d86 RM |
2000 | while (task_running(rq, p)) { |
2001 | if (match_state && unlikely(p->state != match_state)) | |
2002 | return 0; | |
3a5c359a | 2003 | cpu_relax(); |
85ba2d86 | 2004 | } |
fa490cfd | 2005 | |
3a5c359a AK |
2006 | /* |
2007 | * Ok, time to look more closely! We need the rq | |
2008 | * lock now, to be *sure*. If we're wrong, we'll | |
2009 | * just go back and repeat. | |
2010 | */ | |
2011 | rq = task_rq_lock(p, &flags); | |
0a16b607 | 2012 | trace_sched_wait_task(rq, p); |
3a5c359a AK |
2013 | running = task_running(rq, p); |
2014 | on_rq = p->se.on_rq; | |
85ba2d86 | 2015 | ncsw = 0; |
f31e11d8 | 2016 | if (!match_state || p->state == match_state) |
93dcf55f | 2017 | ncsw = p->nvcsw | LONG_MIN; /* sets MSB */ |
3a5c359a | 2018 | task_rq_unlock(rq, &flags); |
fa490cfd | 2019 | |
85ba2d86 RM |
2020 | /* |
2021 | * If it changed from the expected state, bail out now. | |
2022 | */ | |
2023 | if (unlikely(!ncsw)) | |
2024 | break; | |
2025 | ||
3a5c359a AK |
2026 | /* |
2027 | * Was it really running after all now that we | |
2028 | * checked with the proper locks actually held? | |
2029 | * | |
2030 | * Oops. Go back and try again.. | |
2031 | */ | |
2032 | if (unlikely(running)) { | |
2033 | cpu_relax(); | |
2034 | continue; | |
2035 | } | |
fa490cfd | 2036 | |
3a5c359a AK |
2037 | /* |
2038 | * It's not enough that it's not actively running, | |
2039 | * it must be off the runqueue _entirely_, and not | |
2040 | * preempted! | |
2041 | * | |
2042 | * So if it wa still runnable (but just not actively | |
2043 | * running right now), it's preempted, and we should | |
2044 | * yield - it could be a while. | |
2045 | */ | |
2046 | if (unlikely(on_rq)) { | |
2047 | schedule_timeout_uninterruptible(1); | |
2048 | continue; | |
2049 | } | |
fa490cfd | 2050 | |
3a5c359a AK |
2051 | /* |
2052 | * Ahh, all good. It wasn't running, and it wasn't | |
2053 | * runnable, which means that it will never become | |
2054 | * running in the future either. We're all done! | |
2055 | */ | |
2056 | break; | |
2057 | } | |
85ba2d86 RM |
2058 | |
2059 | return ncsw; | |
1da177e4 LT |
2060 | } |
2061 | ||
2062 | /*** | |
2063 | * kick_process - kick a running thread to enter/exit the kernel | |
2064 | * @p: the to-be-kicked thread | |
2065 | * | |
2066 | * Cause a process which is running on another CPU to enter | |
2067 | * kernel-mode, without any delay. (to get signals handled.) | |
2068 | * | |
2069 | * NOTE: this function doesnt have to take the runqueue lock, | |
2070 | * because all it wants to ensure is that the remote task enters | |
2071 | * the kernel. If the IPI races and the task has been migrated | |
2072 | * to another CPU then no harm is done and the purpose has been | |
2073 | * achieved as well. | |
2074 | */ | |
36c8b586 | 2075 | void kick_process(struct task_struct *p) |
1da177e4 LT |
2076 | { |
2077 | int cpu; | |
2078 | ||
2079 | preempt_disable(); | |
2080 | cpu = task_cpu(p); | |
2081 | if ((cpu != smp_processor_id()) && task_curr(p)) | |
2082 | smp_send_reschedule(cpu); | |
2083 | preempt_enable(); | |
2084 | } | |
2085 | ||
2086 | /* | |
2dd73a4f PW |
2087 | * Return a low guess at the load of a migration-source cpu weighted |
2088 | * according to the scheduling class and "nice" value. | |
1da177e4 LT |
2089 | * |
2090 | * We want to under-estimate the load of migration sources, to | |
2091 | * balance conservatively. | |
2092 | */ | |
a9957449 | 2093 | static unsigned long source_load(int cpu, int type) |
1da177e4 | 2094 | { |
70b97a7f | 2095 | struct rq *rq = cpu_rq(cpu); |
dd41f596 | 2096 | unsigned long total = weighted_cpuload(cpu); |
2dd73a4f | 2097 | |
93b75217 | 2098 | if (type == 0 || !sched_feat(LB_BIAS)) |
dd41f596 | 2099 | return total; |
b910472d | 2100 | |
dd41f596 | 2101 | return min(rq->cpu_load[type-1], total); |
1da177e4 LT |
2102 | } |
2103 | ||
2104 | /* | |
2dd73a4f PW |
2105 | * Return a high guess at the load of a migration-target cpu weighted |
2106 | * according to the scheduling class and "nice" value. | |
1da177e4 | 2107 | */ |
a9957449 | 2108 | static unsigned long target_load(int cpu, int type) |
1da177e4 | 2109 | { |
70b97a7f | 2110 | struct rq *rq = cpu_rq(cpu); |
dd41f596 | 2111 | unsigned long total = weighted_cpuload(cpu); |
2dd73a4f | 2112 | |
93b75217 | 2113 | if (type == 0 || !sched_feat(LB_BIAS)) |
dd41f596 | 2114 | return total; |
3b0bd9bc | 2115 | |
dd41f596 | 2116 | return max(rq->cpu_load[type-1], total); |
2dd73a4f PW |
2117 | } |
2118 | ||
147cbb4b NP |
2119 | /* |
2120 | * find_idlest_group finds and returns the least busy CPU group within the | |
2121 | * domain. | |
2122 | */ | |
2123 | static struct sched_group * | |
2124 | find_idlest_group(struct sched_domain *sd, struct task_struct *p, int this_cpu) | |
2125 | { | |
2126 | struct sched_group *idlest = NULL, *this = NULL, *group = sd->groups; | |
2127 | unsigned long min_load = ULONG_MAX, this_load = 0; | |
2128 | int load_idx = sd->forkexec_idx; | |
2129 | int imbalance = 100 + (sd->imbalance_pct-100)/2; | |
2130 | ||
2131 | do { | |
2132 | unsigned long load, avg_load; | |
2133 | int local_group; | |
2134 | int i; | |
2135 | ||
da5a5522 | 2136 | /* Skip over this group if it has no CPUs allowed */ |
758b2cdc RR |
2137 | if (!cpumask_intersects(sched_group_cpus(group), |
2138 | &p->cpus_allowed)) | |
3a5c359a | 2139 | continue; |
da5a5522 | 2140 | |
758b2cdc RR |
2141 | local_group = cpumask_test_cpu(this_cpu, |
2142 | sched_group_cpus(group)); | |
147cbb4b NP |
2143 | |
2144 | /* Tally up the load of all CPUs in the group */ | |
2145 | avg_load = 0; | |
2146 | ||
758b2cdc | 2147 | for_each_cpu(i, sched_group_cpus(group)) { |
147cbb4b NP |
2148 | /* Bias balancing toward cpus of our domain */ |
2149 | if (local_group) | |
2150 | load = source_load(i, load_idx); | |
2151 | else | |
2152 | load = target_load(i, load_idx); | |
2153 | ||
2154 | avg_load += load; | |
2155 | } | |
2156 | ||
2157 | /* Adjust by relative CPU power of the group */ | |
5517d86b ED |
2158 | avg_load = sg_div_cpu_power(group, |
2159 | avg_load * SCHED_LOAD_SCALE); | |
147cbb4b NP |
2160 | |
2161 | if (local_group) { | |
2162 | this_load = avg_load; | |
2163 | this = group; | |
2164 | } else if (avg_load < min_load) { | |
2165 | min_load = avg_load; | |
2166 | idlest = group; | |
2167 | } | |
3a5c359a | 2168 | } while (group = group->next, group != sd->groups); |
147cbb4b NP |
2169 | |
2170 | if (!idlest || 100*this_load < imbalance*min_load) | |
2171 | return NULL; | |
2172 | return idlest; | |
2173 | } | |
2174 | ||
2175 | /* | |
0feaece9 | 2176 | * find_idlest_cpu - find the idlest cpu among the cpus in group. |
147cbb4b | 2177 | */ |
95cdf3b7 | 2178 | static int |
758b2cdc | 2179 | find_idlest_cpu(struct sched_group *group, struct task_struct *p, int this_cpu) |
147cbb4b NP |
2180 | { |
2181 | unsigned long load, min_load = ULONG_MAX; | |
2182 | int idlest = -1; | |
2183 | int i; | |
2184 | ||
da5a5522 | 2185 | /* Traverse only the allowed CPUs */ |
758b2cdc | 2186 | for_each_cpu_and(i, sched_group_cpus(group), &p->cpus_allowed) { |
2dd73a4f | 2187 | load = weighted_cpuload(i); |
147cbb4b NP |
2188 | |
2189 | if (load < min_load || (load == min_load && i == this_cpu)) { | |
2190 | min_load = load; | |
2191 | idlest = i; | |
2192 | } | |
2193 | } | |
2194 | ||
2195 | return idlest; | |
2196 | } | |
2197 | ||
476d139c NP |
2198 | /* |
2199 | * sched_balance_self: balance the current task (running on cpu) in domains | |
2200 | * that have the 'flag' flag set. In practice, this is SD_BALANCE_FORK and | |
2201 | * SD_BALANCE_EXEC. | |
2202 | * | |
2203 | * Balance, ie. select the least loaded group. | |
2204 | * | |
2205 | * Returns the target CPU number, or the same CPU if no balancing is needed. | |
2206 | * | |
2207 | * preempt must be disabled. | |
2208 | */ | |
2209 | static int sched_balance_self(int cpu, int flag) | |
2210 | { | |
2211 | struct task_struct *t = current; | |
2212 | struct sched_domain *tmp, *sd = NULL; | |
147cbb4b | 2213 | |
c96d145e | 2214 | for_each_domain(cpu, tmp) { |
9761eea8 IM |
2215 | /* |
2216 | * If power savings logic is enabled for a domain, stop there. | |
2217 | */ | |
5c45bf27 SS |
2218 | if (tmp->flags & SD_POWERSAVINGS_BALANCE) |
2219 | break; | |
476d139c NP |
2220 | if (tmp->flags & flag) |
2221 | sd = tmp; | |
c96d145e | 2222 | } |
476d139c | 2223 | |
039a1c41 PZ |
2224 | if (sd) |
2225 | update_shares(sd); | |
2226 | ||
476d139c | 2227 | while (sd) { |
476d139c | 2228 | struct sched_group *group; |
1a848870 SS |
2229 | int new_cpu, weight; |
2230 | ||
2231 | if (!(sd->flags & flag)) { | |
2232 | sd = sd->child; | |
2233 | continue; | |
2234 | } | |
476d139c | 2235 | |
476d139c | 2236 | group = find_idlest_group(sd, t, cpu); |
1a848870 SS |
2237 | if (!group) { |
2238 | sd = sd->child; | |
2239 | continue; | |
2240 | } | |
476d139c | 2241 | |
758b2cdc | 2242 | new_cpu = find_idlest_cpu(group, t, cpu); |
1a848870 SS |
2243 | if (new_cpu == -1 || new_cpu == cpu) { |
2244 | /* Now try balancing at a lower domain level of cpu */ | |
2245 | sd = sd->child; | |
2246 | continue; | |
2247 | } | |
476d139c | 2248 | |
1a848870 | 2249 | /* Now try balancing at a lower domain level of new_cpu */ |
476d139c | 2250 | cpu = new_cpu; |
758b2cdc | 2251 | weight = cpumask_weight(sched_domain_span(sd)); |
476d139c | 2252 | sd = NULL; |
476d139c | 2253 | for_each_domain(cpu, tmp) { |
758b2cdc | 2254 | if (weight <= cpumask_weight(sched_domain_span(tmp))) |
476d139c NP |
2255 | break; |
2256 | if (tmp->flags & flag) | |
2257 | sd = tmp; | |
2258 | } | |
2259 | /* while loop will break here if sd == NULL */ | |
2260 | } | |
2261 | ||
2262 | return cpu; | |
2263 | } | |
2264 | ||
2265 | #endif /* CONFIG_SMP */ | |
1da177e4 | 2266 | |
0793a61d TG |
2267 | /** |
2268 | * task_oncpu_function_call - call a function on the cpu on which a task runs | |
2269 | * @p: the task to evaluate | |
2270 | * @func: the function to be called | |
2271 | * @info: the function call argument | |
2272 | * | |
2273 | * Calls the function @func when the task is currently running. This might | |
2274 | * be on the current CPU, which just calls the function directly | |
2275 | */ | |
2276 | void task_oncpu_function_call(struct task_struct *p, | |
2277 | void (*func) (void *info), void *info) | |
2278 | { | |
2279 | int cpu; | |
2280 | ||
2281 | preempt_disable(); | |
2282 | cpu = task_cpu(p); | |
2283 | if (task_curr(p)) | |
2284 | smp_call_function_single(cpu, func, info, 1); | |
2285 | preempt_enable(); | |
2286 | } | |
2287 | ||
1da177e4 LT |
2288 | /*** |
2289 | * try_to_wake_up - wake up a thread | |
2290 | * @p: the to-be-woken-up thread | |
2291 | * @state: the mask of task states that can be woken | |
2292 | * @sync: do a synchronous wakeup? | |
2293 | * | |
2294 | * Put it on the run-queue if it's not already there. The "current" | |
2295 | * thread is always on the run-queue (except when the actual | |
2296 | * re-schedule is in progress), and as such you're allowed to do | |
2297 | * the simpler "current->state = TASK_RUNNING" to mark yourself | |
2298 | * runnable without the overhead of this. | |
2299 | * | |
2300 | * returns failure only if the task is already active. | |
2301 | */ | |
36c8b586 | 2302 | static int try_to_wake_up(struct task_struct *p, unsigned int state, int sync) |
1da177e4 | 2303 | { |
cc367732 | 2304 | int cpu, orig_cpu, this_cpu, success = 0; |
1da177e4 LT |
2305 | unsigned long flags; |
2306 | long old_state; | |
70b97a7f | 2307 | struct rq *rq; |
1da177e4 | 2308 | |
b85d0667 IM |
2309 | if (!sched_feat(SYNC_WAKEUPS)) |
2310 | sync = 0; | |
2311 | ||
2398f2c6 PZ |
2312 | #ifdef CONFIG_SMP |
2313 | if (sched_feat(LB_WAKEUP_UPDATE)) { | |
2314 | struct sched_domain *sd; | |
2315 | ||
2316 | this_cpu = raw_smp_processor_id(); | |
2317 | cpu = task_cpu(p); | |
2318 | ||
2319 | for_each_domain(this_cpu, sd) { | |
758b2cdc | 2320 | if (cpumask_test_cpu(cpu, sched_domain_span(sd))) { |
2398f2c6 PZ |
2321 | update_shares(sd); |
2322 | break; | |
2323 | } | |
2324 | } | |
2325 | } | |
2326 | #endif | |
2327 | ||
04e2f174 | 2328 | smp_wmb(); |
1da177e4 | 2329 | rq = task_rq_lock(p, &flags); |
03e89e45 | 2330 | update_rq_clock(rq); |
1da177e4 LT |
2331 | old_state = p->state; |
2332 | if (!(old_state & state)) | |
2333 | goto out; | |
2334 | ||
dd41f596 | 2335 | if (p->se.on_rq) |
1da177e4 LT |
2336 | goto out_running; |
2337 | ||
2338 | cpu = task_cpu(p); | |
cc367732 | 2339 | orig_cpu = cpu; |
1da177e4 LT |
2340 | this_cpu = smp_processor_id(); |
2341 | ||
2342 | #ifdef CONFIG_SMP | |
2343 | if (unlikely(task_running(rq, p))) | |
2344 | goto out_activate; | |
2345 | ||
5d2f5a61 DA |
2346 | cpu = p->sched_class->select_task_rq(p, sync); |
2347 | if (cpu != orig_cpu) { | |
2348 | set_task_cpu(p, cpu); | |
1da177e4 LT |
2349 | task_rq_unlock(rq, &flags); |
2350 | /* might preempt at this point */ | |
2351 | rq = task_rq_lock(p, &flags); | |
2352 | old_state = p->state; | |
2353 | if (!(old_state & state)) | |
2354 | goto out; | |
dd41f596 | 2355 | if (p->se.on_rq) |
1da177e4 LT |
2356 | goto out_running; |
2357 | ||
2358 | this_cpu = smp_processor_id(); | |
2359 | cpu = task_cpu(p); | |
2360 | } | |
2361 | ||
e7693a36 GH |
2362 | #ifdef CONFIG_SCHEDSTATS |
2363 | schedstat_inc(rq, ttwu_count); | |
2364 | if (cpu == this_cpu) | |
2365 | schedstat_inc(rq, ttwu_local); | |
2366 | else { | |
2367 | struct sched_domain *sd; | |
2368 | for_each_domain(this_cpu, sd) { | |
758b2cdc | 2369 | if (cpumask_test_cpu(cpu, sched_domain_span(sd))) { |
e7693a36 GH |
2370 | schedstat_inc(sd, ttwu_wake_remote); |
2371 | break; | |
2372 | } | |
2373 | } | |
2374 | } | |
6d6bc0ad | 2375 | #endif /* CONFIG_SCHEDSTATS */ |
e7693a36 | 2376 | |
1da177e4 LT |
2377 | out_activate: |
2378 | #endif /* CONFIG_SMP */ | |
cc367732 IM |
2379 | schedstat_inc(p, se.nr_wakeups); |
2380 | if (sync) | |
2381 | schedstat_inc(p, se.nr_wakeups_sync); | |
2382 | if (orig_cpu != cpu) | |
2383 | schedstat_inc(p, se.nr_wakeups_migrate); | |
2384 | if (cpu == this_cpu) | |
2385 | schedstat_inc(p, se.nr_wakeups_local); | |
2386 | else | |
2387 | schedstat_inc(p, se.nr_wakeups_remote); | |
dd41f596 | 2388 | activate_task(rq, p, 1); |
1da177e4 LT |
2389 | success = 1; |
2390 | ||
2391 | out_running: | |
468a15bb | 2392 | trace_sched_wakeup(rq, p, success); |
15afe09b | 2393 | check_preempt_curr(rq, p, sync); |
4ae7d5ce | 2394 | |
1da177e4 | 2395 | p->state = TASK_RUNNING; |
9a897c5a SR |
2396 | #ifdef CONFIG_SMP |
2397 | if (p->sched_class->task_wake_up) | |
2398 | p->sched_class->task_wake_up(rq, p); | |
2399 | #endif | |
1da177e4 | 2400 | out: |
2087a1ad GH |
2401 | current->se.last_wakeup = current->se.sum_exec_runtime; |
2402 | ||
1da177e4 LT |
2403 | task_rq_unlock(rq, &flags); |
2404 | ||
2405 | return success; | |
2406 | } | |
2407 | ||
7ad5b3a5 | 2408 | int wake_up_process(struct task_struct *p) |
1da177e4 | 2409 | { |
d9514f6c | 2410 | return try_to_wake_up(p, TASK_ALL, 0); |
1da177e4 | 2411 | } |
1da177e4 LT |
2412 | EXPORT_SYMBOL(wake_up_process); |
2413 | ||
7ad5b3a5 | 2414 | int wake_up_state(struct task_struct *p, unsigned int state) |
1da177e4 LT |
2415 | { |
2416 | return try_to_wake_up(p, state, 0); | |
2417 | } | |
2418 | ||
1da177e4 LT |
2419 | /* |
2420 | * Perform scheduler related setup for a newly forked process p. | |
2421 | * p is forked by current. | |
dd41f596 IM |
2422 | * |
2423 | * __sched_fork() is basic setup used by init_idle() too: | |
2424 | */ | |
2425 | static void __sched_fork(struct task_struct *p) | |
2426 | { | |
dd41f596 IM |
2427 | p->se.exec_start = 0; |
2428 | p->se.sum_exec_runtime = 0; | |
f6cf891c | 2429 | p->se.prev_sum_exec_runtime = 0; |
6c594c21 | 2430 | p->se.nr_migrations = 0; |
4ae7d5ce IM |
2431 | p->se.last_wakeup = 0; |
2432 | p->se.avg_overlap = 0; | |
6cfb0d5d IM |
2433 | |
2434 | #ifdef CONFIG_SCHEDSTATS | |
2435 | p->se.wait_start = 0; | |
dd41f596 IM |
2436 | p->se.sum_sleep_runtime = 0; |
2437 | p->se.sleep_start = 0; | |
dd41f596 IM |
2438 | p->se.block_start = 0; |
2439 | p->se.sleep_max = 0; | |
2440 | p->se.block_max = 0; | |
2441 | p->se.exec_max = 0; | |
eba1ed4b | 2442 | p->se.slice_max = 0; |
dd41f596 | 2443 | p->se.wait_max = 0; |
6cfb0d5d | 2444 | #endif |
476d139c | 2445 | |
fa717060 | 2446 | INIT_LIST_HEAD(&p->rt.run_list); |
dd41f596 | 2447 | p->se.on_rq = 0; |
4a55bd5e | 2448 | INIT_LIST_HEAD(&p->se.group_node); |
476d139c | 2449 | |
e107be36 AK |
2450 | #ifdef CONFIG_PREEMPT_NOTIFIERS |
2451 | INIT_HLIST_HEAD(&p->preempt_notifiers); | |
2452 | #endif | |
2453 | ||
1da177e4 LT |
2454 | /* |
2455 | * We mark the process as running here, but have not actually | |
2456 | * inserted it onto the runqueue yet. This guarantees that | |
2457 | * nobody will actually run it, and a signal or other external | |
2458 | * event cannot wake it up and insert it on the runqueue either. | |
2459 | */ | |
2460 | p->state = TASK_RUNNING; | |
dd41f596 IM |
2461 | } |
2462 | ||
2463 | /* | |
2464 | * fork()/clone()-time setup: | |
2465 | */ | |
2466 | void sched_fork(struct task_struct *p, int clone_flags) | |
2467 | { | |
2468 | int cpu = get_cpu(); | |
2469 | ||
2470 | __sched_fork(p); | |
2471 | ||
2472 | #ifdef CONFIG_SMP | |
2473 | cpu = sched_balance_self(cpu, SD_BALANCE_FORK); | |
2474 | #endif | |
02e4bac2 | 2475 | set_task_cpu(p, cpu); |
b29739f9 IM |
2476 | |
2477 | /* | |
2478 | * Make sure we do not leak PI boosting priority to the child: | |
2479 | */ | |
2480 | p->prio = current->normal_prio; | |
2ddbf952 HS |
2481 | if (!rt_prio(p->prio)) |
2482 | p->sched_class = &fair_sched_class; | |
b29739f9 | 2483 | |
52f17b6c | 2484 | #if defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT) |
dd41f596 | 2485 | if (likely(sched_info_on())) |
52f17b6c | 2486 | memset(&p->sched_info, 0, sizeof(p->sched_info)); |
1da177e4 | 2487 | #endif |
d6077cb8 | 2488 | #if defined(CONFIG_SMP) && defined(__ARCH_WANT_UNLOCKED_CTXSW) |
4866cde0 NP |
2489 | p->oncpu = 0; |
2490 | #endif | |
1da177e4 | 2491 | #ifdef CONFIG_PREEMPT |
4866cde0 | 2492 | /* Want to start with kernel preemption disabled. */ |
a1261f54 | 2493 | task_thread_info(p)->preempt_count = 1; |
1da177e4 | 2494 | #endif |
476d139c | 2495 | put_cpu(); |
1da177e4 LT |
2496 | } |
2497 | ||
2498 | /* | |
2499 | * wake_up_new_task - wake up a newly created task for the first time. | |
2500 | * | |
2501 | * This function will do some initial scheduler statistics housekeeping | |
2502 | * that must be done for every newly created context, then puts the task | |
2503 | * on the runqueue and wakes it. | |
2504 | */ | |
7ad5b3a5 | 2505 | void wake_up_new_task(struct task_struct *p, unsigned long clone_flags) |
1da177e4 LT |
2506 | { |
2507 | unsigned long flags; | |
dd41f596 | 2508 | struct rq *rq; |
1da177e4 LT |
2509 | |
2510 | rq = task_rq_lock(p, &flags); | |
147cbb4b | 2511 | BUG_ON(p->state != TASK_RUNNING); |
a8e504d2 | 2512 | update_rq_clock(rq); |
1da177e4 LT |
2513 | |
2514 | p->prio = effective_prio(p); | |
2515 | ||
b9dca1e0 | 2516 | if (!p->sched_class->task_new || !current->se.on_rq) { |
dd41f596 | 2517 | activate_task(rq, p, 0); |
1da177e4 | 2518 | } else { |
1da177e4 | 2519 | /* |
dd41f596 IM |
2520 | * Let the scheduling class do new task startup |
2521 | * management (if any): | |
1da177e4 | 2522 | */ |
ee0827d8 | 2523 | p->sched_class->task_new(rq, p); |
c09595f6 | 2524 | inc_nr_running(rq); |
1da177e4 | 2525 | } |
c71dd42d | 2526 | trace_sched_wakeup_new(rq, p, 1); |
15afe09b | 2527 | check_preempt_curr(rq, p, 0); |
9a897c5a SR |
2528 | #ifdef CONFIG_SMP |
2529 | if (p->sched_class->task_wake_up) | |
2530 | p->sched_class->task_wake_up(rq, p); | |
2531 | #endif | |
dd41f596 | 2532 | task_rq_unlock(rq, &flags); |
1da177e4 LT |
2533 | } |
2534 | ||
e107be36 AK |
2535 | #ifdef CONFIG_PREEMPT_NOTIFIERS |
2536 | ||
2537 | /** | |
421cee29 RD |
2538 | * preempt_notifier_register - tell me when current is being being preempted & rescheduled |
2539 | * @notifier: notifier struct to register | |
e107be36 AK |
2540 | */ |
2541 | void preempt_notifier_register(struct preempt_notifier *notifier) | |
2542 | { | |
2543 | hlist_add_head(¬ifier->link, ¤t->preempt_notifiers); | |
2544 | } | |
2545 | EXPORT_SYMBOL_GPL(preempt_notifier_register); | |
2546 | ||
2547 | /** | |
2548 | * preempt_notifier_unregister - no longer interested in preemption notifications | |
421cee29 | 2549 | * @notifier: notifier struct to unregister |
e107be36 AK |
2550 | * |
2551 | * This is safe to call from within a preemption notifier. | |
2552 | */ | |
2553 | void preempt_notifier_unregister(struct preempt_notifier *notifier) | |
2554 | { | |
2555 | hlist_del(¬ifier->link); | |
2556 | } | |
2557 | EXPORT_SYMBOL_GPL(preempt_notifier_unregister); | |
2558 | ||
2559 | static void fire_sched_in_preempt_notifiers(struct task_struct *curr) | |
2560 | { | |
2561 | struct preempt_notifier *notifier; | |
2562 | struct hlist_node *node; | |
2563 | ||
2564 | hlist_for_each_entry(notifier, node, &curr->preempt_notifiers, link) | |
2565 | notifier->ops->sched_in(notifier, raw_smp_processor_id()); | |
2566 | } | |
2567 | ||
2568 | static void | |
2569 | fire_sched_out_preempt_notifiers(struct task_struct *curr, | |
2570 | struct task_struct *next) | |
2571 | { | |
2572 | struct preempt_notifier *notifier; | |
2573 | struct hlist_node *node; | |
2574 | ||
2575 | hlist_for_each_entry(notifier, node, &curr->preempt_notifiers, link) | |
2576 | notifier->ops->sched_out(notifier, next); | |
2577 | } | |
2578 | ||
6d6bc0ad | 2579 | #else /* !CONFIG_PREEMPT_NOTIFIERS */ |
e107be36 AK |
2580 | |
2581 | static void fire_sched_in_preempt_notifiers(struct task_struct *curr) | |
2582 | { | |
2583 | } | |
2584 | ||
2585 | static void | |
2586 | fire_sched_out_preempt_notifiers(struct task_struct *curr, | |
2587 | struct task_struct *next) | |
2588 | { | |
2589 | } | |
2590 | ||
6d6bc0ad | 2591 | #endif /* CONFIG_PREEMPT_NOTIFIERS */ |
e107be36 | 2592 | |
4866cde0 NP |
2593 | /** |
2594 | * prepare_task_switch - prepare to switch tasks | |
2595 | * @rq: the runqueue preparing to switch | |
421cee29 | 2596 | * @prev: the current task that is being switched out |
4866cde0 NP |
2597 | * @next: the task we are going to switch to. |
2598 | * | |
2599 | * This is called with the rq lock held and interrupts off. It must | |
2600 | * be paired with a subsequent finish_task_switch after the context | |
2601 | * switch. | |
2602 | * | |
2603 | * prepare_task_switch sets up locking and calls architecture specific | |
2604 | * hooks. | |
2605 | */ | |
e107be36 AK |
2606 | static inline void |
2607 | prepare_task_switch(struct rq *rq, struct task_struct *prev, | |
2608 | struct task_struct *next) | |
4866cde0 | 2609 | { |
e107be36 | 2610 | fire_sched_out_preempt_notifiers(prev, next); |
4866cde0 NP |
2611 | prepare_lock_switch(rq, next); |
2612 | prepare_arch_switch(next); | |
2613 | } | |
2614 | ||
1da177e4 LT |
2615 | /** |
2616 | * finish_task_switch - clean up after a task-switch | |
344babaa | 2617 | * @rq: runqueue associated with task-switch |
1da177e4 LT |
2618 | * @prev: the thread we just switched away from. |
2619 | * | |
4866cde0 NP |
2620 | * finish_task_switch must be called after the context switch, paired |
2621 | * with a prepare_task_switch call before the context switch. | |
2622 | * finish_task_switch will reconcile locking set up by prepare_task_switch, | |
2623 | * and do any other architecture-specific cleanup actions. | |
1da177e4 LT |
2624 | * |
2625 | * Note that we may have delayed dropping an mm in context_switch(). If | |
41a2d6cf | 2626 | * so, we finish that here outside of the runqueue lock. (Doing it |
1da177e4 LT |
2627 | * with the lock held can cause deadlocks; see schedule() for |
2628 | * details.) | |
2629 | */ | |
a9957449 | 2630 | static void finish_task_switch(struct rq *rq, struct task_struct *prev) |
1da177e4 LT |
2631 | __releases(rq->lock) |
2632 | { | |
1da177e4 | 2633 | struct mm_struct *mm = rq->prev_mm; |
55a101f8 | 2634 | long prev_state; |
1da177e4 LT |
2635 | |
2636 | rq->prev_mm = NULL; | |
2637 | ||
2638 | /* | |
2639 | * A task struct has one reference for the use as "current". | |
c394cc9f | 2640 | * If a task dies, then it sets TASK_DEAD in tsk->state and calls |
55a101f8 ON |
2641 | * schedule one last time. The schedule call will never return, and |
2642 | * the scheduled task must drop that reference. | |
c394cc9f | 2643 | * The test for TASK_DEAD must occur while the runqueue locks are |
1da177e4 LT |
2644 | * still held, otherwise prev could be scheduled on another cpu, die |
2645 | * there before we look at prev->state, and then the reference would | |
2646 | * be dropped twice. | |
2647 | * Manfred Spraul <manfred@colorfullife.com> | |
2648 | */ | |
55a101f8 | 2649 | prev_state = prev->state; |
4866cde0 | 2650 | finish_arch_switch(prev); |
0793a61d | 2651 | perf_counter_task_sched_in(current, cpu_of(rq)); |
4866cde0 | 2652 | finish_lock_switch(rq, prev); |
9a897c5a SR |
2653 | #ifdef CONFIG_SMP |
2654 | if (current->sched_class->post_schedule) | |
2655 | current->sched_class->post_schedule(rq); | |
2656 | #endif | |
e8fa1362 | 2657 | |
e107be36 | 2658 | fire_sched_in_preempt_notifiers(current); |
1da177e4 LT |
2659 | if (mm) |
2660 | mmdrop(mm); | |
c394cc9f | 2661 | if (unlikely(prev_state == TASK_DEAD)) { |
c6fd91f0 | 2662 | /* |
2663 | * Remove function-return probe instances associated with this | |
2664 | * task and put them back on the free list. | |
9761eea8 | 2665 | */ |
c6fd91f0 | 2666 | kprobe_flush_task(prev); |
1da177e4 | 2667 | put_task_struct(prev); |
c6fd91f0 | 2668 | } |
1da177e4 LT |
2669 | } |
2670 | ||
2671 | /** | |
2672 | * schedule_tail - first thing a freshly forked thread must call. | |
2673 | * @prev: the thread we just switched away from. | |
2674 | */ | |
36c8b586 | 2675 | asmlinkage void schedule_tail(struct task_struct *prev) |
1da177e4 LT |
2676 | __releases(rq->lock) |
2677 | { | |
70b97a7f IM |
2678 | struct rq *rq = this_rq(); |
2679 | ||
4866cde0 NP |
2680 | finish_task_switch(rq, prev); |
2681 | #ifdef __ARCH_WANT_UNLOCKED_CTXSW | |
2682 | /* In this case, finish_task_switch does not reenable preemption */ | |
2683 | preempt_enable(); | |
2684 | #endif | |
1da177e4 | 2685 | if (current->set_child_tid) |
b488893a | 2686 | put_user(task_pid_vnr(current), current->set_child_tid); |
1da177e4 LT |
2687 | } |
2688 | ||
2689 | /* | |
2690 | * context_switch - switch to the new MM and the new | |
2691 | * thread's register state. | |
2692 | */ | |
dd41f596 | 2693 | static inline void |
70b97a7f | 2694 | context_switch(struct rq *rq, struct task_struct *prev, |
36c8b586 | 2695 | struct task_struct *next) |
1da177e4 | 2696 | { |
dd41f596 | 2697 | struct mm_struct *mm, *oldmm; |
1da177e4 | 2698 | |
e107be36 | 2699 | prepare_task_switch(rq, prev, next); |
0a16b607 | 2700 | trace_sched_switch(rq, prev, next); |
dd41f596 IM |
2701 | mm = next->mm; |
2702 | oldmm = prev->active_mm; | |
9226d125 ZA |
2703 | /* |
2704 | * For paravirt, this is coupled with an exit in switch_to to | |
2705 | * combine the page table reload and the switch backend into | |
2706 | * one hypercall. | |
2707 | */ | |
2708 | arch_enter_lazy_cpu_mode(); | |
2709 | ||
dd41f596 | 2710 | if (unlikely(!mm)) { |
1da177e4 LT |
2711 | next->active_mm = oldmm; |
2712 | atomic_inc(&oldmm->mm_count); | |
2713 | enter_lazy_tlb(oldmm, next); | |
2714 | } else | |
2715 | switch_mm(oldmm, mm, next); | |
2716 | ||
dd41f596 | 2717 | if (unlikely(!prev->mm)) { |
1da177e4 | 2718 | prev->active_mm = NULL; |
1da177e4 LT |
2719 | rq->prev_mm = oldmm; |
2720 | } | |
3a5f5e48 IM |
2721 | /* |
2722 | * Since the runqueue lock will be released by the next | |
2723 | * task (which is an invalid locking op but in the case | |
2724 | * of the scheduler it's an obvious special-case), so we | |
2725 | * do an early lockdep release here: | |
2726 | */ | |
2727 | #ifndef __ARCH_WANT_UNLOCKED_CTXSW | |
8a25d5de | 2728 | spin_release(&rq->lock.dep_map, 1, _THIS_IP_); |
3a5f5e48 | 2729 | #endif |
1da177e4 LT |
2730 | |
2731 | /* Here we just switch the register state and the stack. */ | |
2732 | switch_to(prev, next, prev); | |
2733 | ||
dd41f596 IM |
2734 | barrier(); |
2735 | /* | |
2736 | * this_rq must be evaluated again because prev may have moved | |
2737 | * CPUs since it called schedule(), thus the 'rq' on its stack | |
2738 | * frame will be invalid. | |
2739 | */ | |
2740 | finish_task_switch(this_rq(), prev); | |
1da177e4 LT |
2741 | } |
2742 | ||
2743 | /* | |
2744 | * nr_running, nr_uninterruptible and nr_context_switches: | |
2745 | * | |
2746 | * externally visible scheduler statistics: current number of runnable | |
2747 | * threads, current number of uninterruptible-sleeping threads, total | |
2748 | * number of context switches performed since bootup. | |
2749 | */ | |
2750 | unsigned long nr_running(void) | |
2751 | { | |
2752 | unsigned long i, sum = 0; | |
2753 | ||
2754 | for_each_online_cpu(i) | |
2755 | sum += cpu_rq(i)->nr_running; | |
2756 | ||
2757 | return sum; | |
2758 | } | |
2759 | ||
2760 | unsigned long nr_uninterruptible(void) | |
2761 | { | |
2762 | unsigned long i, sum = 0; | |
2763 | ||
0a945022 | 2764 | for_each_possible_cpu(i) |
1da177e4 LT |
2765 | sum += cpu_rq(i)->nr_uninterruptible; |
2766 | ||
2767 | /* | |
2768 | * Since we read the counters lockless, it might be slightly | |
2769 | * inaccurate. Do not allow it to go below zero though: | |
2770 | */ | |
2771 | if (unlikely((long)sum < 0)) | |
2772 | sum = 0; | |
2773 | ||
2774 | return sum; | |
2775 | } | |
2776 | ||
2777 | unsigned long long nr_context_switches(void) | |
2778 | { | |
cc94abfc SR |
2779 | int i; |
2780 | unsigned long long sum = 0; | |
1da177e4 | 2781 | |
0a945022 | 2782 | for_each_possible_cpu(i) |
1da177e4 LT |
2783 | sum += cpu_rq(i)->nr_switches; |
2784 | ||
2785 | return sum; | |
2786 | } | |
2787 | ||
2788 | unsigned long nr_iowait(void) | |
2789 | { | |
2790 | unsigned long i, sum = 0; | |
2791 | ||
0a945022 | 2792 | for_each_possible_cpu(i) |
1da177e4 LT |
2793 | sum += atomic_read(&cpu_rq(i)->nr_iowait); |
2794 | ||
2795 | return sum; | |
2796 | } | |
2797 | ||
db1b1fef JS |
2798 | unsigned long nr_active(void) |
2799 | { | |
2800 | unsigned long i, running = 0, uninterruptible = 0; | |
2801 | ||
2802 | for_each_online_cpu(i) { | |
2803 | running += cpu_rq(i)->nr_running; | |
2804 | uninterruptible += cpu_rq(i)->nr_uninterruptible; | |
2805 | } | |
2806 | ||
2807 | if (unlikely((long)uninterruptible < 0)) | |
2808 | uninterruptible = 0; | |
2809 | ||
2810 | return running + uninterruptible; | |
2811 | } | |
2812 | ||
48f24c4d | 2813 | /* |
dd41f596 IM |
2814 | * Update rq->cpu_load[] statistics. This function is usually called every |
2815 | * scheduler tick (TICK_NSEC). | |
48f24c4d | 2816 | */ |
dd41f596 | 2817 | static void update_cpu_load(struct rq *this_rq) |
48f24c4d | 2818 | { |
495eca49 | 2819 | unsigned long this_load = this_rq->load.weight; |
dd41f596 IM |
2820 | int i, scale; |
2821 | ||
2822 | this_rq->nr_load_updates++; | |
dd41f596 IM |
2823 | |
2824 | /* Update our load: */ | |
2825 | for (i = 0, scale = 1; i < CPU_LOAD_IDX_MAX; i++, scale += scale) { | |
2826 | unsigned long old_load, new_load; | |
2827 | ||
2828 | /* scale is effectively 1 << i now, and >> i divides by scale */ | |
2829 | ||
2830 | old_load = this_rq->cpu_load[i]; | |
2831 | new_load = this_load; | |
a25707f3 IM |
2832 | /* |
2833 | * Round up the averaging division if load is increasing. This | |
2834 | * prevents us from getting stuck on 9 if the load is 10, for | |
2835 | * example. | |
2836 | */ | |
2837 | if (new_load > old_load) | |
2838 | new_load += scale-1; | |
dd41f596 IM |
2839 | this_rq->cpu_load[i] = (old_load*(scale-1) + new_load) >> i; |
2840 | } | |
48f24c4d IM |
2841 | } |
2842 | ||
dd41f596 IM |
2843 | #ifdef CONFIG_SMP |
2844 | ||
1da177e4 LT |
2845 | /* |
2846 | * double_rq_lock - safely lock two runqueues | |
2847 | * | |
2848 | * Note this does not disable interrupts like task_rq_lock, | |
2849 | * you need to do so manually before calling. | |
2850 | */ | |
70b97a7f | 2851 | static void double_rq_lock(struct rq *rq1, struct rq *rq2) |
1da177e4 LT |
2852 | __acquires(rq1->lock) |
2853 | __acquires(rq2->lock) | |
2854 | { | |
054b9108 | 2855 | BUG_ON(!irqs_disabled()); |
1da177e4 LT |
2856 | if (rq1 == rq2) { |
2857 | spin_lock(&rq1->lock); | |
2858 | __acquire(rq2->lock); /* Fake it out ;) */ | |
2859 | } else { | |
c96d145e | 2860 | if (rq1 < rq2) { |
1da177e4 | 2861 | spin_lock(&rq1->lock); |
5e710e37 | 2862 | spin_lock_nested(&rq2->lock, SINGLE_DEPTH_NESTING); |
1da177e4 LT |
2863 | } else { |
2864 | spin_lock(&rq2->lock); | |
5e710e37 | 2865 | spin_lock_nested(&rq1->lock, SINGLE_DEPTH_NESTING); |
1da177e4 LT |
2866 | } |
2867 | } | |
6e82a3be IM |
2868 | update_rq_clock(rq1); |
2869 | update_rq_clock(rq2); | |
1da177e4 LT |
2870 | } |
2871 | ||
2872 | /* | |
2873 | * double_rq_unlock - safely unlock two runqueues | |
2874 | * | |
2875 | * Note this does not restore interrupts like task_rq_unlock, | |
2876 | * you need to do so manually after calling. | |
2877 | */ | |
70b97a7f | 2878 | static void double_rq_unlock(struct rq *rq1, struct rq *rq2) |
1da177e4 LT |
2879 | __releases(rq1->lock) |
2880 | __releases(rq2->lock) | |
2881 | { | |
2882 | spin_unlock(&rq1->lock); | |
2883 | if (rq1 != rq2) | |
2884 | spin_unlock(&rq2->lock); | |
2885 | else | |
2886 | __release(rq2->lock); | |
2887 | } | |
2888 | ||
1da177e4 LT |
2889 | /* |
2890 | * If dest_cpu is allowed for this process, migrate the task to it. | |
2891 | * This is accomplished by forcing the cpu_allowed mask to only | |
41a2d6cf | 2892 | * allow dest_cpu, which will force the cpu onto dest_cpu. Then |
1da177e4 LT |
2893 | * the cpu_allowed mask is restored. |
2894 | */ | |
36c8b586 | 2895 | static void sched_migrate_task(struct task_struct *p, int dest_cpu) |
1da177e4 | 2896 | { |
70b97a7f | 2897 | struct migration_req req; |
1da177e4 | 2898 | unsigned long flags; |
70b97a7f | 2899 | struct rq *rq; |
1da177e4 LT |
2900 | |
2901 | rq = task_rq_lock(p, &flags); | |
96f874e2 | 2902 | if (!cpumask_test_cpu(dest_cpu, &p->cpus_allowed) |
e761b772 | 2903 | || unlikely(!cpu_active(dest_cpu))) |
1da177e4 LT |
2904 | goto out; |
2905 | ||
2906 | /* force the process onto the specified CPU */ | |
2907 | if (migrate_task(p, dest_cpu, &req)) { | |
2908 | /* Need to wait for migration thread (might exit: take ref). */ | |
2909 | struct task_struct *mt = rq->migration_thread; | |
36c8b586 | 2910 | |
1da177e4 LT |
2911 | get_task_struct(mt); |
2912 | task_rq_unlock(rq, &flags); | |
2913 | wake_up_process(mt); | |
2914 | put_task_struct(mt); | |
2915 | wait_for_completion(&req.done); | |
36c8b586 | 2916 | |
1da177e4 LT |
2917 | return; |
2918 | } | |
2919 | out: | |
2920 | task_rq_unlock(rq, &flags); | |
2921 | } | |
2922 | ||
2923 | /* | |
476d139c NP |
2924 | * sched_exec - execve() is a valuable balancing opportunity, because at |
2925 | * this point the task has the smallest effective memory and cache footprint. | |
1da177e4 LT |
2926 | */ |
2927 | void sched_exec(void) | |
2928 | { | |
1da177e4 | 2929 | int new_cpu, this_cpu = get_cpu(); |
476d139c | 2930 | new_cpu = sched_balance_self(this_cpu, SD_BALANCE_EXEC); |
1da177e4 | 2931 | put_cpu(); |
476d139c NP |
2932 | if (new_cpu != this_cpu) |
2933 | sched_migrate_task(current, new_cpu); | |
1da177e4 LT |
2934 | } |
2935 | ||
2936 | /* | |
2937 | * pull_task - move a task from a remote runqueue to the local runqueue. | |
2938 | * Both runqueues must be locked. | |
2939 | */ | |
dd41f596 IM |
2940 | static void pull_task(struct rq *src_rq, struct task_struct *p, |
2941 | struct rq *this_rq, int this_cpu) | |
1da177e4 | 2942 | { |
2e1cb74a | 2943 | deactivate_task(src_rq, p, 0); |
1da177e4 | 2944 | set_task_cpu(p, this_cpu); |
dd41f596 | 2945 | activate_task(this_rq, p, 0); |
1da177e4 LT |
2946 | /* |
2947 | * Note that idle threads have a prio of MAX_PRIO, for this test | |
2948 | * to be always true for them. | |
2949 | */ | |
15afe09b | 2950 | check_preempt_curr(this_rq, p, 0); |
1da177e4 LT |
2951 | } |
2952 | ||
2953 | /* | |
2954 | * can_migrate_task - may task p from runqueue rq be migrated to this_cpu? | |
2955 | */ | |
858119e1 | 2956 | static |
70b97a7f | 2957 | int can_migrate_task(struct task_struct *p, struct rq *rq, int this_cpu, |
d15bcfdb | 2958 | struct sched_domain *sd, enum cpu_idle_type idle, |
95cdf3b7 | 2959 | int *all_pinned) |
1da177e4 LT |
2960 | { |
2961 | /* | |
2962 | * We do not migrate tasks that are: | |
2963 | * 1) running (obviously), or | |
2964 | * 2) cannot be migrated to this CPU due to cpus_allowed, or | |
2965 | * 3) are cache-hot on their current CPU. | |
2966 | */ | |
96f874e2 | 2967 | if (!cpumask_test_cpu(this_cpu, &p->cpus_allowed)) { |
cc367732 | 2968 | schedstat_inc(p, se.nr_failed_migrations_affine); |
1da177e4 | 2969 | return 0; |
cc367732 | 2970 | } |
81026794 NP |
2971 | *all_pinned = 0; |
2972 | ||
cc367732 IM |
2973 | if (task_running(rq, p)) { |
2974 | schedstat_inc(p, se.nr_failed_migrations_running); | |
81026794 | 2975 | return 0; |
cc367732 | 2976 | } |
1da177e4 | 2977 | |
da84d961 IM |
2978 | /* |
2979 | * Aggressive migration if: | |
2980 | * 1) task is cache cold, or | |
2981 | * 2) too many balance attempts have failed. | |
2982 | */ | |
2983 | ||
6bc1665b IM |
2984 | if (!task_hot(p, rq->clock, sd) || |
2985 | sd->nr_balance_failed > sd->cache_nice_tries) { | |
da84d961 | 2986 | #ifdef CONFIG_SCHEDSTATS |
cc367732 | 2987 | if (task_hot(p, rq->clock, sd)) { |
da84d961 | 2988 | schedstat_inc(sd, lb_hot_gained[idle]); |
cc367732 IM |
2989 | schedstat_inc(p, se.nr_forced_migrations); |
2990 | } | |
da84d961 IM |
2991 | #endif |
2992 | return 1; | |
2993 | } | |
2994 | ||
cc367732 IM |
2995 | if (task_hot(p, rq->clock, sd)) { |
2996 | schedstat_inc(p, se.nr_failed_migrations_hot); | |
da84d961 | 2997 | return 0; |
cc367732 | 2998 | } |
1da177e4 LT |
2999 | return 1; |
3000 | } | |
3001 | ||
e1d1484f PW |
3002 | static unsigned long |
3003 | balance_tasks(struct rq *this_rq, int this_cpu, struct rq *busiest, | |
3004 | unsigned long max_load_move, struct sched_domain *sd, | |
3005 | enum cpu_idle_type idle, int *all_pinned, | |
3006 | int *this_best_prio, struct rq_iterator *iterator) | |
1da177e4 | 3007 | { |
051c6764 | 3008 | int loops = 0, pulled = 0, pinned = 0; |
dd41f596 IM |
3009 | struct task_struct *p; |
3010 | long rem_load_move = max_load_move; | |
1da177e4 | 3011 | |
e1d1484f | 3012 | if (max_load_move == 0) |
1da177e4 LT |
3013 | goto out; |
3014 | ||
81026794 NP |
3015 | pinned = 1; |
3016 | ||
1da177e4 | 3017 | /* |
dd41f596 | 3018 | * Start the load-balancing iterator: |
1da177e4 | 3019 | */ |
dd41f596 IM |
3020 | p = iterator->start(iterator->arg); |
3021 | next: | |
b82d9fdd | 3022 | if (!p || loops++ > sysctl_sched_nr_migrate) |
1da177e4 | 3023 | goto out; |
051c6764 PZ |
3024 | |
3025 | if ((p->se.load.weight >> 1) > rem_load_move || | |
dd41f596 | 3026 | !can_migrate_task(p, busiest, this_cpu, sd, idle, &pinned)) { |
dd41f596 IM |
3027 | p = iterator->next(iterator->arg); |
3028 | goto next; | |
1da177e4 LT |
3029 | } |
3030 | ||
dd41f596 | 3031 | pull_task(busiest, p, this_rq, this_cpu); |
1da177e4 | 3032 | pulled++; |
dd41f596 | 3033 | rem_load_move -= p->se.load.weight; |
1da177e4 | 3034 | |
2dd73a4f | 3035 | /* |
b82d9fdd | 3036 | * We only want to steal up to the prescribed amount of weighted load. |
2dd73a4f | 3037 | */ |
e1d1484f | 3038 | if (rem_load_move > 0) { |
a4ac01c3 PW |
3039 | if (p->prio < *this_best_prio) |
3040 | *this_best_prio = p->prio; | |
dd41f596 IM |
3041 | p = iterator->next(iterator->arg); |
3042 | goto next; | |
1da177e4 LT |
3043 | } |
3044 | out: | |
3045 | /* | |
e1d1484f | 3046 | * Right now, this is one of only two places pull_task() is called, |
1da177e4 LT |
3047 | * so we can safely collect pull_task() stats here rather than |
3048 | * inside pull_task(). | |
3049 | */ | |
3050 | schedstat_add(sd, lb_gained[idle], pulled); | |
81026794 NP |
3051 | |
3052 | if (all_pinned) | |
3053 | *all_pinned = pinned; | |
e1d1484f PW |
3054 | |
3055 | return max_load_move - rem_load_move; | |
1da177e4 LT |
3056 | } |
3057 | ||
dd41f596 | 3058 | /* |
43010659 PW |
3059 | * move_tasks tries to move up to max_load_move weighted load from busiest to |
3060 | * this_rq, as part of a balancing operation within domain "sd". | |
3061 | * Returns 1 if successful and 0 otherwise. | |
dd41f596 IM |
3062 | * |
3063 | * Called with both runqueues locked. | |
3064 | */ | |
3065 | static int move_tasks(struct rq *this_rq, int this_cpu, struct rq *busiest, | |
43010659 | 3066 | unsigned long max_load_move, |
dd41f596 IM |
3067 | struct sched_domain *sd, enum cpu_idle_type idle, |
3068 | int *all_pinned) | |
3069 | { | |
5522d5d5 | 3070 | const struct sched_class *class = sched_class_highest; |
43010659 | 3071 | unsigned long total_load_moved = 0; |
a4ac01c3 | 3072 | int this_best_prio = this_rq->curr->prio; |
dd41f596 IM |
3073 | |
3074 | do { | |
43010659 PW |
3075 | total_load_moved += |
3076 | class->load_balance(this_rq, this_cpu, busiest, | |
e1d1484f | 3077 | max_load_move - total_load_moved, |
a4ac01c3 | 3078 | sd, idle, all_pinned, &this_best_prio); |
dd41f596 | 3079 | class = class->next; |
c4acb2c0 GH |
3080 | |
3081 | if (idle == CPU_NEWLY_IDLE && this_rq->nr_running) | |
3082 | break; | |
3083 | ||
43010659 | 3084 | } while (class && max_load_move > total_load_moved); |
dd41f596 | 3085 | |
43010659 PW |
3086 | return total_load_moved > 0; |
3087 | } | |
3088 | ||
e1d1484f PW |
3089 | static int |
3090 | iter_move_one_task(struct rq *this_rq, int this_cpu, struct rq *busiest, | |
3091 | struct sched_domain *sd, enum cpu_idle_type idle, | |
3092 | struct rq_iterator *iterator) | |
3093 | { | |
3094 | struct task_struct *p = iterator->start(iterator->arg); | |
3095 | int pinned = 0; | |
3096 | ||
3097 | while (p) { | |
3098 | if (can_migrate_task(p, busiest, this_cpu, sd, idle, &pinned)) { | |
3099 | pull_task(busiest, p, this_rq, this_cpu); | |
3100 | /* | |
3101 | * Right now, this is only the second place pull_task() | |
3102 | * is called, so we can safely collect pull_task() | |
3103 | * stats here rather than inside pull_task(). | |
3104 | */ | |
3105 | schedstat_inc(sd, lb_gained[idle]); | |
3106 | ||
3107 | return 1; | |
3108 | } | |
3109 | p = iterator->next(iterator->arg); | |
3110 | } | |
3111 | ||
3112 | return 0; | |
3113 | } | |
3114 | ||
43010659 PW |
3115 | /* |
3116 | * move_one_task tries to move exactly one task from busiest to this_rq, as | |
3117 | * part of active balancing operations within "domain". | |
3118 | * Returns 1 if successful and 0 otherwise. | |
3119 | * | |
3120 | * Called with both runqueues locked. | |
3121 | */ | |
3122 | static int move_one_task(struct rq *this_rq, int this_cpu, struct rq *busiest, | |
3123 | struct sched_domain *sd, enum cpu_idle_type idle) | |
3124 | { | |
5522d5d5 | 3125 | const struct sched_class *class; |
43010659 PW |
3126 | |
3127 | for (class = sched_class_highest; class; class = class->next) | |
e1d1484f | 3128 | if (class->move_one_task(this_rq, this_cpu, busiest, sd, idle)) |
43010659 PW |
3129 | return 1; |
3130 | ||
3131 | return 0; | |
dd41f596 IM |
3132 | } |
3133 | ||
1da177e4 LT |
3134 | /* |
3135 | * find_busiest_group finds and returns the busiest CPU group within the | |
48f24c4d IM |
3136 | * domain. It calculates and returns the amount of weighted load which |
3137 | * should be moved to restore balance via the imbalance parameter. | |
1da177e4 LT |
3138 | */ |
3139 | static struct sched_group * | |
3140 | find_busiest_group(struct sched_domain *sd, int this_cpu, | |
dd41f596 | 3141 | unsigned long *imbalance, enum cpu_idle_type idle, |
96f874e2 | 3142 | int *sd_idle, const struct cpumask *cpus, int *balance) |
1da177e4 LT |
3143 | { |
3144 | struct sched_group *busiest = NULL, *this = NULL, *group = sd->groups; | |
3145 | unsigned long max_load, avg_load, total_load, this_load, total_pwr; | |
0c117f1b | 3146 | unsigned long max_pull; |
2dd73a4f PW |
3147 | unsigned long busiest_load_per_task, busiest_nr_running; |
3148 | unsigned long this_load_per_task, this_nr_running; | |
908a7c1b | 3149 | int load_idx, group_imb = 0; |
5c45bf27 SS |
3150 | #if defined(CONFIG_SCHED_MC) || defined(CONFIG_SCHED_SMT) |
3151 | int power_savings_balance = 1; | |
3152 | unsigned long leader_nr_running = 0, min_load_per_task = 0; | |
3153 | unsigned long min_nr_running = ULONG_MAX; | |
3154 | struct sched_group *group_min = NULL, *group_leader = NULL; | |
3155 | #endif | |
1da177e4 LT |
3156 | |
3157 | max_load = this_load = total_load = total_pwr = 0; | |
2dd73a4f PW |
3158 | busiest_load_per_task = busiest_nr_running = 0; |
3159 | this_load_per_task = this_nr_running = 0; | |
408ed066 | 3160 | |
d15bcfdb | 3161 | if (idle == CPU_NOT_IDLE) |
7897986b | 3162 | load_idx = sd->busy_idx; |
d15bcfdb | 3163 | else if (idle == CPU_NEWLY_IDLE) |
7897986b NP |
3164 | load_idx = sd->newidle_idx; |
3165 | else | |
3166 | load_idx = sd->idle_idx; | |
1da177e4 LT |
3167 | |
3168 | do { | |
908a7c1b | 3169 | unsigned long load, group_capacity, max_cpu_load, min_cpu_load; |
1da177e4 LT |
3170 | int local_group; |
3171 | int i; | |
908a7c1b | 3172 | int __group_imb = 0; |
783609c6 | 3173 | unsigned int balance_cpu = -1, first_idle_cpu = 0; |
2dd73a4f | 3174 | unsigned long sum_nr_running, sum_weighted_load; |
408ed066 PZ |
3175 | unsigned long sum_avg_load_per_task; |
3176 | unsigned long avg_load_per_task; | |
1da177e4 | 3177 | |
758b2cdc RR |
3178 | local_group = cpumask_test_cpu(this_cpu, |
3179 | sched_group_cpus(group)); | |
1da177e4 | 3180 | |
783609c6 | 3181 | if (local_group) |
758b2cdc | 3182 | balance_cpu = cpumask_first(sched_group_cpus(group)); |
783609c6 | 3183 | |
1da177e4 | 3184 | /* Tally up the load of all CPUs in the group */ |
2dd73a4f | 3185 | sum_weighted_load = sum_nr_running = avg_load = 0; |
408ed066 PZ |
3186 | sum_avg_load_per_task = avg_load_per_task = 0; |
3187 | ||
908a7c1b KC |
3188 | max_cpu_load = 0; |
3189 | min_cpu_load = ~0UL; | |
1da177e4 | 3190 | |
758b2cdc RR |
3191 | for_each_cpu_and(i, sched_group_cpus(group), cpus) { |
3192 | struct rq *rq = cpu_rq(i); | |
2dd73a4f | 3193 | |
9439aab8 | 3194 | if (*sd_idle && rq->nr_running) |
5969fe06 NP |
3195 | *sd_idle = 0; |
3196 | ||
1da177e4 | 3197 | /* Bias balancing toward cpus of our domain */ |
783609c6 SS |
3198 | if (local_group) { |
3199 | if (idle_cpu(i) && !first_idle_cpu) { | |
3200 | first_idle_cpu = 1; | |
3201 | balance_cpu = i; | |
3202 | } | |
3203 | ||
a2000572 | 3204 | load = target_load(i, load_idx); |
908a7c1b | 3205 | } else { |
a2000572 | 3206 | load = source_load(i, load_idx); |
908a7c1b KC |
3207 | if (load > max_cpu_load) |
3208 | max_cpu_load = load; | |
3209 | if (min_cpu_load > load) | |
3210 | min_cpu_load = load; | |
3211 | } | |
1da177e4 LT |
3212 | |
3213 | avg_load += load; | |
2dd73a4f | 3214 | sum_nr_running += rq->nr_running; |
dd41f596 | 3215 | sum_weighted_load += weighted_cpuload(i); |
408ed066 PZ |
3216 | |
3217 | sum_avg_load_per_task += cpu_avg_load_per_task(i); | |
1da177e4 LT |
3218 | } |
3219 | ||
783609c6 SS |
3220 | /* |
3221 | * First idle cpu or the first cpu(busiest) in this sched group | |
3222 | * is eligible for doing load balancing at this and above | |
9439aab8 SS |
3223 | * domains. In the newly idle case, we will allow all the cpu's |
3224 | * to do the newly idle load balance. | |
783609c6 | 3225 | */ |
9439aab8 SS |
3226 | if (idle != CPU_NEWLY_IDLE && local_group && |
3227 | balance_cpu != this_cpu && balance) { | |
783609c6 SS |
3228 | *balance = 0; |
3229 | goto ret; | |
3230 | } | |
3231 | ||
1da177e4 | 3232 | total_load += avg_load; |
5517d86b | 3233 | total_pwr += group->__cpu_power; |
1da177e4 LT |
3234 | |
3235 | /* Adjust by relative CPU power of the group */ | |
5517d86b ED |
3236 | avg_load = sg_div_cpu_power(group, |
3237 | avg_load * SCHED_LOAD_SCALE); | |
1da177e4 | 3238 | |
408ed066 PZ |
3239 | |
3240 | /* | |
3241 | * Consider the group unbalanced when the imbalance is larger | |
3242 | * than the average weight of two tasks. | |
3243 | * | |
3244 | * APZ: with cgroup the avg task weight can vary wildly and | |
3245 | * might not be a suitable number - should we keep a | |
3246 | * normalized nr_running number somewhere that negates | |
3247 | * the hierarchy? | |
3248 | */ | |
3249 | avg_load_per_task = sg_div_cpu_power(group, | |
3250 | sum_avg_load_per_task * SCHED_LOAD_SCALE); | |
3251 | ||
3252 | if ((max_cpu_load - min_cpu_load) > 2*avg_load_per_task) | |
908a7c1b KC |
3253 | __group_imb = 1; |
3254 | ||
5517d86b | 3255 | group_capacity = group->__cpu_power / SCHED_LOAD_SCALE; |
5c45bf27 | 3256 | |
1da177e4 LT |
3257 | if (local_group) { |
3258 | this_load = avg_load; | |
3259 | this = group; | |
2dd73a4f PW |
3260 | this_nr_running = sum_nr_running; |
3261 | this_load_per_task = sum_weighted_load; | |
3262 | } else if (avg_load > max_load && | |
908a7c1b | 3263 | (sum_nr_running > group_capacity || __group_imb)) { |
1da177e4 LT |
3264 | max_load = avg_load; |
3265 | busiest = group; | |
2dd73a4f PW |
3266 | busiest_nr_running = sum_nr_running; |
3267 | busiest_load_per_task = sum_weighted_load; | |
908a7c1b | 3268 | group_imb = __group_imb; |
1da177e4 | 3269 | } |
5c45bf27 SS |
3270 | |
3271 | #if defined(CONFIG_SCHED_MC) || defined(CONFIG_SCHED_SMT) | |
3272 | /* | |
3273 | * Busy processors will not participate in power savings | |
3274 | * balance. | |
3275 | */ | |
dd41f596 IM |
3276 | if (idle == CPU_NOT_IDLE || |
3277 | !(sd->flags & SD_POWERSAVINGS_BALANCE)) | |
3278 | goto group_next; | |
5c45bf27 SS |
3279 | |
3280 | /* | |
3281 | * If the local group is idle or completely loaded | |
3282 | * no need to do power savings balance at this domain | |
3283 | */ | |
3284 | if (local_group && (this_nr_running >= group_capacity || | |
3285 | !this_nr_running)) | |
3286 | power_savings_balance = 0; | |
3287 | ||
dd41f596 | 3288 | /* |
5c45bf27 SS |
3289 | * If a group is already running at full capacity or idle, |
3290 | * don't include that group in power savings calculations | |
dd41f596 IM |
3291 | */ |
3292 | if (!power_savings_balance || sum_nr_running >= group_capacity | |
5c45bf27 | 3293 | || !sum_nr_running) |
dd41f596 | 3294 | goto group_next; |
5c45bf27 | 3295 | |
dd41f596 | 3296 | /* |
5c45bf27 | 3297 | * Calculate the group which has the least non-idle load. |
dd41f596 IM |
3298 | * This is the group from where we need to pick up the load |
3299 | * for saving power | |
3300 | */ | |
3301 | if ((sum_nr_running < min_nr_running) || | |
3302 | (sum_nr_running == min_nr_running && | |
d5679bd1 | 3303 | cpumask_first(sched_group_cpus(group)) > |
758b2cdc | 3304 | cpumask_first(sched_group_cpus(group_min)))) { |
dd41f596 IM |
3305 | group_min = group; |
3306 | min_nr_running = sum_nr_running; | |
5c45bf27 SS |
3307 | min_load_per_task = sum_weighted_load / |
3308 | sum_nr_running; | |
dd41f596 | 3309 | } |
5c45bf27 | 3310 | |
dd41f596 | 3311 | /* |
5c45bf27 | 3312 | * Calculate the group which is almost near its |
dd41f596 IM |
3313 | * capacity but still has some space to pick up some load |
3314 | * from other group and save more power | |
3315 | */ | |
3316 | if (sum_nr_running <= group_capacity - 1) { | |
3317 | if (sum_nr_running > leader_nr_running || | |
3318 | (sum_nr_running == leader_nr_running && | |
d5679bd1 | 3319 | cpumask_first(sched_group_cpus(group)) < |
758b2cdc | 3320 | cpumask_first(sched_group_cpus(group_leader)))) { |
dd41f596 IM |
3321 | group_leader = group; |
3322 | leader_nr_running = sum_nr_running; | |
3323 | } | |
48f24c4d | 3324 | } |
5c45bf27 SS |
3325 | group_next: |
3326 | #endif | |
1da177e4 LT |
3327 | group = group->next; |
3328 | } while (group != sd->groups); | |
3329 | ||
2dd73a4f | 3330 | if (!busiest || this_load >= max_load || busiest_nr_running == 0) |
1da177e4 LT |
3331 | goto out_balanced; |
3332 | ||
3333 | avg_load = (SCHED_LOAD_SCALE * total_load) / total_pwr; | |
3334 | ||
3335 | if (this_load >= avg_load || | |
3336 | 100*max_load <= sd->imbalance_pct*this_load) | |
3337 | goto out_balanced; | |
3338 | ||
2dd73a4f | 3339 | busiest_load_per_task /= busiest_nr_running; |
908a7c1b KC |
3340 | if (group_imb) |
3341 | busiest_load_per_task = min(busiest_load_per_task, avg_load); | |
3342 | ||
1da177e4 LT |
3343 | /* |
3344 | * We're trying to get all the cpus to the average_load, so we don't | |
3345 | * want to push ourselves above the average load, nor do we wish to | |
3346 | * reduce the max loaded cpu below the average load, as either of these | |
3347 | * actions would just result in more rebalancing later, and ping-pong | |
3348 | * tasks around. Thus we look for the minimum possible imbalance. | |
3349 | * Negative imbalances (*we* are more loaded than anyone else) will | |
3350 | * be counted as no imbalance for these purposes -- we can't fix that | |
41a2d6cf | 3351 | * by pulling tasks to us. Be careful of negative numbers as they'll |
1da177e4 LT |
3352 | * appear as very large values with unsigned longs. |
3353 | */ | |
2dd73a4f PW |
3354 | if (max_load <= busiest_load_per_task) |
3355 | goto out_balanced; | |
3356 | ||
3357 | /* | |
3358 | * In the presence of smp nice balancing, certain scenarios can have | |
3359 | * max load less than avg load(as we skip the groups at or below | |
3360 | * its cpu_power, while calculating max_load..) | |
3361 | */ | |
3362 | if (max_load < avg_load) { | |
3363 | *imbalance = 0; | |
3364 | goto small_imbalance; | |
3365 | } | |
0c117f1b SS |
3366 | |
3367 | /* Don't want to pull so many tasks that a group would go idle */ | |
2dd73a4f | 3368 | max_pull = min(max_load - avg_load, max_load - busiest_load_per_task); |
0c117f1b | 3369 | |
1da177e4 | 3370 | /* How much load to actually move to equalise the imbalance */ |
5517d86b ED |
3371 | *imbalance = min(max_pull * busiest->__cpu_power, |
3372 | (avg_load - this_load) * this->__cpu_power) | |
1da177e4 LT |
3373 | / SCHED_LOAD_SCALE; |
3374 | ||
2dd73a4f PW |
3375 | /* |
3376 | * if *imbalance is less than the average load per runnable task | |
3377 | * there is no gaurantee that any tasks will be moved so we'll have | |
3378 | * a think about bumping its value to force at least one task to be | |
3379 | * moved | |
3380 | */ | |
7fd0d2dd | 3381 | if (*imbalance < busiest_load_per_task) { |
48f24c4d | 3382 | unsigned long tmp, pwr_now, pwr_move; |
2dd73a4f PW |
3383 | unsigned int imbn; |
3384 | ||
3385 | small_imbalance: | |
3386 | pwr_move = pwr_now = 0; | |
3387 | imbn = 2; | |
3388 | if (this_nr_running) { | |
3389 | this_load_per_task /= this_nr_running; | |
3390 | if (busiest_load_per_task > this_load_per_task) | |
3391 | imbn = 1; | |
3392 | } else | |
408ed066 | 3393 | this_load_per_task = cpu_avg_load_per_task(this_cpu); |
1da177e4 | 3394 | |
01c8c57d | 3395 | if (max_load - this_load + busiest_load_per_task >= |
dd41f596 | 3396 | busiest_load_per_task * imbn) { |
2dd73a4f | 3397 | *imbalance = busiest_load_per_task; |
1da177e4 LT |
3398 | return busiest; |
3399 | } | |
3400 | ||
3401 | /* | |
3402 | * OK, we don't have enough imbalance to justify moving tasks, | |
3403 | * however we may be able to increase total CPU power used by | |
3404 | * moving them. | |
3405 | */ | |
3406 | ||
5517d86b ED |
3407 | pwr_now += busiest->__cpu_power * |
3408 | min(busiest_load_per_task, max_load); | |
3409 | pwr_now += this->__cpu_power * | |
3410 | min(this_load_per_task, this_load); | |
1da177e4 LT |
3411 | pwr_now /= SCHED_LOAD_SCALE; |
3412 | ||
3413 | /* Amount of load we'd subtract */ | |
5517d86b ED |
3414 | tmp = sg_div_cpu_power(busiest, |
3415 | busiest_load_per_task * SCHED_LOAD_SCALE); | |
1da177e4 | 3416 | if (max_load > tmp) |
5517d86b | 3417 | pwr_move += busiest->__cpu_power * |
2dd73a4f | 3418 | min(busiest_load_per_task, max_load - tmp); |
1da177e4 LT |
3419 | |
3420 | /* Amount of load we'd add */ | |
5517d86b | 3421 | if (max_load * busiest->__cpu_power < |
33859f7f | 3422 | busiest_load_per_task * SCHED_LOAD_SCALE) |
5517d86b ED |
3423 | tmp = sg_div_cpu_power(this, |
3424 | max_load * busiest->__cpu_power); | |
1da177e4 | 3425 | else |
5517d86b ED |
3426 | tmp = sg_div_cpu_power(this, |
3427 | busiest_load_per_task * SCHED_LOAD_SCALE); | |
3428 | pwr_move += this->__cpu_power * | |
3429 | min(this_load_per_task, this_load + tmp); | |
1da177e4 LT |
3430 | pwr_move /= SCHED_LOAD_SCALE; |
3431 | ||
3432 | /* Move if we gain throughput */ | |
7fd0d2dd SS |
3433 | if (pwr_move > pwr_now) |
3434 | *imbalance = busiest_load_per_task; | |
1da177e4 LT |
3435 | } |
3436 | ||
1da177e4 LT |
3437 | return busiest; |
3438 | ||
3439 | out_balanced: | |
5c45bf27 | 3440 | #if defined(CONFIG_SCHED_MC) || defined(CONFIG_SCHED_SMT) |
d15bcfdb | 3441 | if (idle == CPU_NOT_IDLE || !(sd->flags & SD_POWERSAVINGS_BALANCE)) |
5c45bf27 | 3442 | goto ret; |
1da177e4 | 3443 | |
5c45bf27 SS |
3444 | if (this == group_leader && group_leader != group_min) { |
3445 | *imbalance = min_load_per_task; | |
7a09b1a2 VS |
3446 | if (sched_mc_power_savings >= POWERSAVINGS_BALANCE_WAKEUP) { |
3447 | cpu_rq(this_cpu)->rd->sched_mc_preferred_wakeup_cpu = | |
9924da43 | 3448 | cpumask_first(sched_group_cpus(group_leader)); |
7a09b1a2 | 3449 | } |
5c45bf27 SS |
3450 | return group_min; |
3451 | } | |
5c45bf27 | 3452 | #endif |
783609c6 | 3453 | ret: |
1da177e4 LT |
3454 | *imbalance = 0; |
3455 | return NULL; | |
3456 | } | |
3457 | ||
3458 | /* | |
3459 | * find_busiest_queue - find the busiest runqueue among the cpus in group. | |
3460 | */ | |
70b97a7f | 3461 | static struct rq * |
d15bcfdb | 3462 | find_busiest_queue(struct sched_group *group, enum cpu_idle_type idle, |
96f874e2 | 3463 | unsigned long imbalance, const struct cpumask *cpus) |
1da177e4 | 3464 | { |
70b97a7f | 3465 | struct rq *busiest = NULL, *rq; |
2dd73a4f | 3466 | unsigned long max_load = 0; |
1da177e4 LT |
3467 | int i; |
3468 | ||
758b2cdc | 3469 | for_each_cpu(i, sched_group_cpus(group)) { |
dd41f596 | 3470 | unsigned long wl; |
0a2966b4 | 3471 | |
96f874e2 | 3472 | if (!cpumask_test_cpu(i, cpus)) |
0a2966b4 CL |
3473 | continue; |
3474 | ||
48f24c4d | 3475 | rq = cpu_rq(i); |
dd41f596 | 3476 | wl = weighted_cpuload(i); |
2dd73a4f | 3477 | |
dd41f596 | 3478 | if (rq->nr_running == 1 && wl > imbalance) |
2dd73a4f | 3479 | continue; |
1da177e4 | 3480 | |
dd41f596 IM |
3481 | if (wl > max_load) { |
3482 | max_load = wl; | |
48f24c4d | 3483 | busiest = rq; |
1da177e4 LT |
3484 | } |
3485 | } | |
3486 | ||
3487 | return busiest; | |
3488 | } | |
3489 | ||
77391d71 NP |
3490 | /* |
3491 | * Max backoff if we encounter pinned tasks. Pretty arbitrary value, but | |
3492 | * so long as it is large enough. | |
3493 | */ | |
3494 | #define MAX_PINNED_INTERVAL 512 | |
3495 | ||
1da177e4 LT |
3496 | /* |
3497 | * Check this_cpu to ensure it is balanced within domain. Attempt to move | |
3498 | * tasks if there is an imbalance. | |
1da177e4 | 3499 | */ |
70b97a7f | 3500 | static int load_balance(int this_cpu, struct rq *this_rq, |
d15bcfdb | 3501 | struct sched_domain *sd, enum cpu_idle_type idle, |
96f874e2 | 3502 | int *balance, struct cpumask *cpus) |
1da177e4 | 3503 | { |
43010659 | 3504 | int ld_moved, all_pinned = 0, active_balance = 0, sd_idle = 0; |
1da177e4 | 3505 | struct sched_group *group; |
1da177e4 | 3506 | unsigned long imbalance; |
70b97a7f | 3507 | struct rq *busiest; |
fe2eea3f | 3508 | unsigned long flags; |
5969fe06 | 3509 | |
96f874e2 | 3510 | cpumask_setall(cpus); |
7c16ec58 | 3511 | |
89c4710e SS |
3512 | /* |
3513 | * When power savings policy is enabled for the parent domain, idle | |
3514 | * sibling can pick up load irrespective of busy siblings. In this case, | |
dd41f596 | 3515 | * let the state of idle sibling percolate up as CPU_IDLE, instead of |
d15bcfdb | 3516 | * portraying it as CPU_NOT_IDLE. |
89c4710e | 3517 | */ |
d15bcfdb | 3518 | if (idle != CPU_NOT_IDLE && sd->flags & SD_SHARE_CPUPOWER && |
89c4710e | 3519 | !test_sd_parent(sd, SD_POWERSAVINGS_BALANCE)) |
5969fe06 | 3520 | sd_idle = 1; |
1da177e4 | 3521 | |
2d72376b | 3522 | schedstat_inc(sd, lb_count[idle]); |
1da177e4 | 3523 | |
0a2966b4 | 3524 | redo: |
c8cba857 | 3525 | update_shares(sd); |
0a2966b4 | 3526 | group = find_busiest_group(sd, this_cpu, &imbalance, idle, &sd_idle, |
7c16ec58 | 3527 | cpus, balance); |
783609c6 | 3528 | |
06066714 | 3529 | if (*balance == 0) |
783609c6 | 3530 | goto out_balanced; |
783609c6 | 3531 | |
1da177e4 LT |
3532 | if (!group) { |
3533 | schedstat_inc(sd, lb_nobusyg[idle]); | |
3534 | goto out_balanced; | |
3535 | } | |
3536 | ||
7c16ec58 | 3537 | busiest = find_busiest_queue(group, idle, imbalance, cpus); |
1da177e4 LT |
3538 | if (!busiest) { |
3539 | schedstat_inc(sd, lb_nobusyq[idle]); | |
3540 | goto out_balanced; | |
3541 | } | |
3542 | ||
db935dbd | 3543 | BUG_ON(busiest == this_rq); |
1da177e4 LT |
3544 | |
3545 | schedstat_add(sd, lb_imbalance[idle], imbalance); | |
3546 | ||
43010659 | 3547 | ld_moved = 0; |
1da177e4 LT |
3548 | if (busiest->nr_running > 1) { |
3549 | /* | |
3550 | * Attempt to move tasks. If find_busiest_group has found | |
3551 | * an imbalance but busiest->nr_running <= 1, the group is | |
43010659 | 3552 | * still unbalanced. ld_moved simply stays zero, so it is |
1da177e4 LT |
3553 | * correctly treated as an imbalance. |
3554 | */ | |
fe2eea3f | 3555 | local_irq_save(flags); |
e17224bf | 3556 | double_rq_lock(this_rq, busiest); |
43010659 | 3557 | ld_moved = move_tasks(this_rq, this_cpu, busiest, |
48f24c4d | 3558 | imbalance, sd, idle, &all_pinned); |
e17224bf | 3559 | double_rq_unlock(this_rq, busiest); |
fe2eea3f | 3560 | local_irq_restore(flags); |
81026794 | 3561 | |
46cb4b7c SS |
3562 | /* |
3563 | * some other cpu did the load balance for us. | |
3564 | */ | |
43010659 | 3565 | if (ld_moved && this_cpu != smp_processor_id()) |
46cb4b7c SS |
3566 | resched_cpu(this_cpu); |
3567 | ||
81026794 | 3568 | /* All tasks on this runqueue were pinned by CPU affinity */ |
0a2966b4 | 3569 | if (unlikely(all_pinned)) { |
96f874e2 RR |
3570 | cpumask_clear_cpu(cpu_of(busiest), cpus); |
3571 | if (!cpumask_empty(cpus)) | |
0a2966b4 | 3572 | goto redo; |
81026794 | 3573 | goto out_balanced; |
0a2966b4 | 3574 | } |
1da177e4 | 3575 | } |
81026794 | 3576 | |
43010659 | 3577 | if (!ld_moved) { |
1da177e4 LT |
3578 | schedstat_inc(sd, lb_failed[idle]); |
3579 | sd->nr_balance_failed++; | |
3580 | ||
3581 | if (unlikely(sd->nr_balance_failed > sd->cache_nice_tries+2)) { | |
1da177e4 | 3582 | |
fe2eea3f | 3583 | spin_lock_irqsave(&busiest->lock, flags); |
fa3b6ddc SS |
3584 | |
3585 | /* don't kick the migration_thread, if the curr | |
3586 | * task on busiest cpu can't be moved to this_cpu | |
3587 | */ | |
96f874e2 RR |
3588 | if (!cpumask_test_cpu(this_cpu, |
3589 | &busiest->curr->cpus_allowed)) { | |
fe2eea3f | 3590 | spin_unlock_irqrestore(&busiest->lock, flags); |
fa3b6ddc SS |
3591 | all_pinned = 1; |
3592 | goto out_one_pinned; | |
3593 | } | |
3594 | ||
1da177e4 LT |
3595 | if (!busiest->active_balance) { |
3596 | busiest->active_balance = 1; | |
3597 | busiest->push_cpu = this_cpu; | |
81026794 | 3598 | active_balance = 1; |
1da177e4 | 3599 | } |
fe2eea3f | 3600 | spin_unlock_irqrestore(&busiest->lock, flags); |
81026794 | 3601 | if (active_balance) |
1da177e4 LT |
3602 | wake_up_process(busiest->migration_thread); |
3603 | ||
3604 | /* | |
3605 | * We've kicked active balancing, reset the failure | |
3606 | * counter. | |
3607 | */ | |
39507451 | 3608 | sd->nr_balance_failed = sd->cache_nice_tries+1; |
1da177e4 | 3609 | } |
81026794 | 3610 | } else |
1da177e4 LT |
3611 | sd->nr_balance_failed = 0; |
3612 | ||
81026794 | 3613 | if (likely(!active_balance)) { |
1da177e4 LT |
3614 | /* We were unbalanced, so reset the balancing interval */ |
3615 | sd->balance_interval = sd->min_interval; | |
81026794 NP |
3616 | } else { |
3617 | /* | |
3618 | * If we've begun active balancing, start to back off. This | |
3619 | * case may not be covered by the all_pinned logic if there | |
3620 | * is only 1 task on the busy runqueue (because we don't call | |
3621 | * move_tasks). | |
3622 | */ | |
3623 | if (sd->balance_interval < sd->max_interval) | |
3624 | sd->balance_interval *= 2; | |
1da177e4 LT |
3625 | } |
3626 | ||
43010659 | 3627 | if (!ld_moved && !sd_idle && sd->flags & SD_SHARE_CPUPOWER && |
89c4710e | 3628 | !test_sd_parent(sd, SD_POWERSAVINGS_BALANCE)) |
c09595f6 PZ |
3629 | ld_moved = -1; |
3630 | ||
3631 | goto out; | |
1da177e4 LT |
3632 | |
3633 | out_balanced: | |
1da177e4 LT |
3634 | schedstat_inc(sd, lb_balanced[idle]); |
3635 | ||
16cfb1c0 | 3636 | sd->nr_balance_failed = 0; |
fa3b6ddc SS |
3637 | |
3638 | out_one_pinned: | |
1da177e4 | 3639 | /* tune up the balancing interval */ |
77391d71 NP |
3640 | if ((all_pinned && sd->balance_interval < MAX_PINNED_INTERVAL) || |
3641 | (sd->balance_interval < sd->max_interval)) | |
1da177e4 LT |
3642 | sd->balance_interval *= 2; |
3643 | ||
48f24c4d | 3644 | if (!sd_idle && sd->flags & SD_SHARE_CPUPOWER && |
89c4710e | 3645 | !test_sd_parent(sd, SD_POWERSAVINGS_BALANCE)) |
c09595f6 PZ |
3646 | ld_moved = -1; |
3647 | else | |
3648 | ld_moved = 0; | |
3649 | out: | |
c8cba857 PZ |
3650 | if (ld_moved) |
3651 | update_shares(sd); | |
c09595f6 | 3652 | return ld_moved; |
1da177e4 LT |
3653 | } |
3654 | ||
3655 | /* | |
3656 | * Check this_cpu to ensure it is balanced within domain. Attempt to move | |
3657 | * tasks if there is an imbalance. | |
3658 | * | |
d15bcfdb | 3659 | * Called from schedule when this_rq is about to become idle (CPU_NEWLY_IDLE). |
1da177e4 LT |
3660 | * this_rq is locked. |
3661 | */ | |
48f24c4d | 3662 | static int |
7c16ec58 | 3663 | load_balance_newidle(int this_cpu, struct rq *this_rq, struct sched_domain *sd, |
96f874e2 | 3664 | struct cpumask *cpus) |
1da177e4 LT |
3665 | { |
3666 | struct sched_group *group; | |
70b97a7f | 3667 | struct rq *busiest = NULL; |
1da177e4 | 3668 | unsigned long imbalance; |
43010659 | 3669 | int ld_moved = 0; |
5969fe06 | 3670 | int sd_idle = 0; |
969bb4e4 | 3671 | int all_pinned = 0; |
7c16ec58 | 3672 | |
96f874e2 | 3673 | cpumask_setall(cpus); |
5969fe06 | 3674 | |
89c4710e SS |
3675 | /* |
3676 | * When power savings policy is enabled for the parent domain, idle | |
3677 | * sibling can pick up load irrespective of busy siblings. In this case, | |
3678 | * let the state of idle sibling percolate up as IDLE, instead of | |
d15bcfdb | 3679 | * portraying it as CPU_NOT_IDLE. |
89c4710e SS |
3680 | */ |
3681 | if (sd->flags & SD_SHARE_CPUPOWER && | |
3682 | !test_sd_parent(sd, SD_POWERSAVINGS_BALANCE)) | |
5969fe06 | 3683 | sd_idle = 1; |
1da177e4 | 3684 | |
2d72376b | 3685 | schedstat_inc(sd, lb_count[CPU_NEWLY_IDLE]); |
0a2966b4 | 3686 | redo: |
3e5459b4 | 3687 | update_shares_locked(this_rq, sd); |
d15bcfdb | 3688 | group = find_busiest_group(sd, this_cpu, &imbalance, CPU_NEWLY_IDLE, |
7c16ec58 | 3689 | &sd_idle, cpus, NULL); |
1da177e4 | 3690 | if (!group) { |
d15bcfdb | 3691 | schedstat_inc(sd, lb_nobusyg[CPU_NEWLY_IDLE]); |
16cfb1c0 | 3692 | goto out_balanced; |
1da177e4 LT |
3693 | } |
3694 | ||
7c16ec58 | 3695 | busiest = find_busiest_queue(group, CPU_NEWLY_IDLE, imbalance, cpus); |
db935dbd | 3696 | if (!busiest) { |
d15bcfdb | 3697 | schedstat_inc(sd, lb_nobusyq[CPU_NEWLY_IDLE]); |
16cfb1c0 | 3698 | goto out_balanced; |
1da177e4 LT |
3699 | } |
3700 | ||
db935dbd NP |
3701 | BUG_ON(busiest == this_rq); |
3702 | ||
d15bcfdb | 3703 | schedstat_add(sd, lb_imbalance[CPU_NEWLY_IDLE], imbalance); |
d6d5cfaf | 3704 | |
43010659 | 3705 | ld_moved = 0; |
d6d5cfaf NP |
3706 | if (busiest->nr_running > 1) { |
3707 | /* Attempt to move tasks */ | |
3708 | double_lock_balance(this_rq, busiest); | |
6e82a3be IM |
3709 | /* this_rq->clock is already updated */ |
3710 | update_rq_clock(busiest); | |
43010659 | 3711 | ld_moved = move_tasks(this_rq, this_cpu, busiest, |
969bb4e4 SS |
3712 | imbalance, sd, CPU_NEWLY_IDLE, |
3713 | &all_pinned); | |
1b12bbc7 | 3714 | double_unlock_balance(this_rq, busiest); |
0a2966b4 | 3715 | |
969bb4e4 | 3716 | if (unlikely(all_pinned)) { |
96f874e2 RR |
3717 | cpumask_clear_cpu(cpu_of(busiest), cpus); |
3718 | if (!cpumask_empty(cpus)) | |
0a2966b4 CL |
3719 | goto redo; |
3720 | } | |
d6d5cfaf NP |
3721 | } |
3722 | ||
43010659 | 3723 | if (!ld_moved) { |
36dffab6 | 3724 | int active_balance = 0; |
ad273b32 | 3725 | |
d15bcfdb | 3726 | schedstat_inc(sd, lb_failed[CPU_NEWLY_IDLE]); |
89c4710e SS |
3727 | if (!sd_idle && sd->flags & SD_SHARE_CPUPOWER && |
3728 | !test_sd_parent(sd, SD_POWERSAVINGS_BALANCE)) | |
5969fe06 | 3729 | return -1; |
ad273b32 VS |
3730 | |
3731 | if (sched_mc_power_savings < POWERSAVINGS_BALANCE_WAKEUP) | |
3732 | return -1; | |
3733 | ||
3734 | if (sd->nr_balance_failed++ < 2) | |
3735 | return -1; | |
3736 | ||
3737 | /* | |
3738 | * The only task running in a non-idle cpu can be moved to this | |
3739 | * cpu in an attempt to completely freeup the other CPU | |
3740 | * package. The same method used to move task in load_balance() | |
3741 | * have been extended for load_balance_newidle() to speedup | |
3742 | * consolidation at sched_mc=POWERSAVINGS_BALANCE_WAKEUP (2) | |
3743 | * | |
3744 | * The package power saving logic comes from | |
3745 | * find_busiest_group(). If there are no imbalance, then | |
3746 | * f_b_g() will return NULL. However when sched_mc={1,2} then | |
3747 | * f_b_g() will select a group from which a running task may be | |
3748 | * pulled to this cpu in order to make the other package idle. | |
3749 | * If there is no opportunity to make a package idle and if | |
3750 | * there are no imbalance, then f_b_g() will return NULL and no | |
3751 | * action will be taken in load_balance_newidle(). | |
3752 | * | |
3753 | * Under normal task pull operation due to imbalance, there | |
3754 | * will be more than one task in the source run queue and | |
3755 | * move_tasks() will succeed. ld_moved will be true and this | |
3756 | * active balance code will not be triggered. | |
3757 | */ | |
3758 | ||
3759 | /* Lock busiest in correct order while this_rq is held */ | |
3760 | double_lock_balance(this_rq, busiest); | |
3761 | ||
3762 | /* | |
3763 | * don't kick the migration_thread, if the curr | |
3764 | * task on busiest cpu can't be moved to this_cpu | |
3765 | */ | |
6ca09dfc | 3766 | if (!cpumask_test_cpu(this_cpu, &busiest->curr->cpus_allowed)) { |
ad273b32 VS |
3767 | double_unlock_balance(this_rq, busiest); |
3768 | all_pinned = 1; | |
3769 | return ld_moved; | |
3770 | } | |
3771 | ||
3772 | if (!busiest->active_balance) { | |
3773 | busiest->active_balance = 1; | |
3774 | busiest->push_cpu = this_cpu; | |
3775 | active_balance = 1; | |
3776 | } | |
3777 | ||
3778 | double_unlock_balance(this_rq, busiest); | |
da8d5089 PZ |
3779 | /* |
3780 | * Should not call ttwu while holding a rq->lock | |
3781 | */ | |
3782 | spin_unlock(&this_rq->lock); | |
ad273b32 VS |
3783 | if (active_balance) |
3784 | wake_up_process(busiest->migration_thread); | |
da8d5089 | 3785 | spin_lock(&this_rq->lock); |
ad273b32 | 3786 | |
5969fe06 | 3787 | } else |
16cfb1c0 | 3788 | sd->nr_balance_failed = 0; |
1da177e4 | 3789 | |
3e5459b4 | 3790 | update_shares_locked(this_rq, sd); |
43010659 | 3791 | return ld_moved; |
16cfb1c0 NP |
3792 | |
3793 | out_balanced: | |
d15bcfdb | 3794 | schedstat_inc(sd, lb_balanced[CPU_NEWLY_IDLE]); |
48f24c4d | 3795 | if (!sd_idle && sd->flags & SD_SHARE_CPUPOWER && |
89c4710e | 3796 | !test_sd_parent(sd, SD_POWERSAVINGS_BALANCE)) |
5969fe06 | 3797 | return -1; |
16cfb1c0 | 3798 | sd->nr_balance_failed = 0; |
48f24c4d | 3799 | |
16cfb1c0 | 3800 | return 0; |
1da177e4 LT |
3801 | } |
3802 | ||
3803 | /* | |
3804 | * idle_balance is called by schedule() if this_cpu is about to become | |
3805 | * idle. Attempts to pull tasks from other CPUs. | |
3806 | */ | |
70b97a7f | 3807 | static void idle_balance(int this_cpu, struct rq *this_rq) |
1da177e4 LT |
3808 | { |
3809 | struct sched_domain *sd; | |
efbe027e | 3810 | int pulled_task = 0; |
dd41f596 | 3811 | unsigned long next_balance = jiffies + HZ; |
4d2732c6 RR |
3812 | cpumask_var_t tmpmask; |
3813 | ||
3814 | if (!alloc_cpumask_var(&tmpmask, GFP_ATOMIC)) | |
3815 | return; | |
1da177e4 LT |
3816 | |
3817 | for_each_domain(this_cpu, sd) { | |
92c4ca5c CL |
3818 | unsigned long interval; |
3819 | ||
3820 | if (!(sd->flags & SD_LOAD_BALANCE)) | |
3821 | continue; | |
3822 | ||
3823 | if (sd->flags & SD_BALANCE_NEWIDLE) | |
48f24c4d | 3824 | /* If we've pulled tasks over stop searching: */ |
7c16ec58 | 3825 | pulled_task = load_balance_newidle(this_cpu, this_rq, |
4d2732c6 | 3826 | sd, tmpmask); |
92c4ca5c CL |
3827 | |
3828 | interval = msecs_to_jiffies(sd->balance_interval); | |
3829 | if (time_after(next_balance, sd->last_balance + interval)) | |
3830 | next_balance = sd->last_balance + interval; | |
3831 | if (pulled_task) | |
3832 | break; | |
1da177e4 | 3833 | } |
dd41f596 | 3834 | if (pulled_task || time_after(jiffies, this_rq->next_balance)) { |
1bd77f2d CL |
3835 | /* |
3836 | * We are going idle. next_balance may be set based on | |
3837 | * a busy processor. So reset next_balance. | |
3838 | */ | |
3839 | this_rq->next_balance = next_balance; | |
dd41f596 | 3840 | } |
4d2732c6 | 3841 | free_cpumask_var(tmpmask); |
1da177e4 LT |
3842 | } |
3843 | ||
3844 | /* | |
3845 | * active_load_balance is run by migration threads. It pushes running tasks | |
3846 | * off the busiest CPU onto idle CPUs. It requires at least 1 task to be | |
3847 | * running on each physical CPU where possible, and avoids physical / | |
3848 | * logical imbalances. | |
3849 | * | |
3850 | * Called with busiest_rq locked. | |
3851 | */ | |
70b97a7f | 3852 | static void active_load_balance(struct rq *busiest_rq, int busiest_cpu) |
1da177e4 | 3853 | { |
39507451 | 3854 | int target_cpu = busiest_rq->push_cpu; |
70b97a7f IM |
3855 | struct sched_domain *sd; |
3856 | struct rq *target_rq; | |
39507451 | 3857 | |
48f24c4d | 3858 | /* Is there any task to move? */ |
39507451 | 3859 | if (busiest_rq->nr_running <= 1) |
39507451 NP |
3860 | return; |
3861 | ||
3862 | target_rq = cpu_rq(target_cpu); | |
1da177e4 LT |
3863 | |
3864 | /* | |
39507451 | 3865 | * This condition is "impossible", if it occurs |
41a2d6cf | 3866 | * we need to fix it. Originally reported by |
39507451 | 3867 | * Bjorn Helgaas on a 128-cpu setup. |
1da177e4 | 3868 | */ |
39507451 | 3869 | BUG_ON(busiest_rq == target_rq); |
1da177e4 | 3870 | |
39507451 NP |
3871 | /* move a task from busiest_rq to target_rq */ |
3872 | double_lock_balance(busiest_rq, target_rq); | |
6e82a3be IM |
3873 | update_rq_clock(busiest_rq); |
3874 | update_rq_clock(target_rq); | |
39507451 NP |
3875 | |
3876 | /* Search for an sd spanning us and the target CPU. */ | |
c96d145e | 3877 | for_each_domain(target_cpu, sd) { |
39507451 | 3878 | if ((sd->flags & SD_LOAD_BALANCE) && |
758b2cdc | 3879 | cpumask_test_cpu(busiest_cpu, sched_domain_span(sd))) |
39507451 | 3880 | break; |
c96d145e | 3881 | } |
39507451 | 3882 | |
48f24c4d | 3883 | if (likely(sd)) { |
2d72376b | 3884 | schedstat_inc(sd, alb_count); |
39507451 | 3885 | |
43010659 PW |
3886 | if (move_one_task(target_rq, target_cpu, busiest_rq, |
3887 | sd, CPU_IDLE)) | |
48f24c4d IM |
3888 | schedstat_inc(sd, alb_pushed); |
3889 | else | |
3890 | schedstat_inc(sd, alb_failed); | |
3891 | } | |
1b12bbc7 | 3892 | double_unlock_balance(busiest_rq, target_rq); |
1da177e4 LT |
3893 | } |
3894 | ||
46cb4b7c SS |
3895 | #ifdef CONFIG_NO_HZ |
3896 | static struct { | |
3897 | atomic_t load_balancer; | |
7d1e6a9b | 3898 | cpumask_var_t cpu_mask; |
46cb4b7c SS |
3899 | } nohz ____cacheline_aligned = { |
3900 | .load_balancer = ATOMIC_INIT(-1), | |
46cb4b7c SS |
3901 | }; |
3902 | ||
7835b98b | 3903 | /* |
46cb4b7c SS |
3904 | * This routine will try to nominate the ilb (idle load balancing) |
3905 | * owner among the cpus whose ticks are stopped. ilb owner will do the idle | |
3906 | * load balancing on behalf of all those cpus. If all the cpus in the system | |
3907 | * go into this tickless mode, then there will be no ilb owner (as there is | |
3908 | * no need for one) and all the cpus will sleep till the next wakeup event | |
3909 | * arrives... | |
3910 | * | |
3911 | * For the ilb owner, tick is not stopped. And this tick will be used | |
3912 | * for idle load balancing. ilb owner will still be part of | |
3913 | * nohz.cpu_mask.. | |
7835b98b | 3914 | * |
46cb4b7c SS |
3915 | * While stopping the tick, this cpu will become the ilb owner if there |
3916 | * is no other owner. And will be the owner till that cpu becomes busy | |
3917 | * or if all cpus in the system stop their ticks at which point | |
3918 | * there is no need for ilb owner. | |
3919 | * | |
3920 | * When the ilb owner becomes busy, it nominates another owner, during the | |
3921 | * next busy scheduler_tick() | |
3922 | */ | |
3923 | int select_nohz_load_balancer(int stop_tick) | |
3924 | { | |
3925 | int cpu = smp_processor_id(); | |
3926 | ||
3927 | if (stop_tick) { | |
7d1e6a9b | 3928 | cpumask_set_cpu(cpu, nohz.cpu_mask); |
46cb4b7c SS |
3929 | cpu_rq(cpu)->in_nohz_recently = 1; |
3930 | ||
3931 | /* | |
3932 | * If we are going offline and still the leader, give up! | |
3933 | */ | |
e761b772 | 3934 | if (!cpu_active(cpu) && |
46cb4b7c SS |
3935 | atomic_read(&nohz.load_balancer) == cpu) { |
3936 | if (atomic_cmpxchg(&nohz.load_balancer, cpu, -1) != cpu) | |
3937 | BUG(); | |
3938 | return 0; | |
3939 | } | |
3940 | ||
3941 | /* time for ilb owner also to sleep */ | |
7d1e6a9b | 3942 | if (cpumask_weight(nohz.cpu_mask) == num_online_cpus()) { |
46cb4b7c SS |
3943 | if (atomic_read(&nohz.load_balancer) == cpu) |
3944 | atomic_set(&nohz.load_balancer, -1); | |
3945 | return 0; | |
3946 | } | |
3947 | ||
3948 | if (atomic_read(&nohz.load_balancer) == -1) { | |
3949 | /* make me the ilb owner */ | |
3950 | if (atomic_cmpxchg(&nohz.load_balancer, -1, cpu) == -1) | |
3951 | return 1; | |
3952 | } else if (atomic_read(&nohz.load_balancer) == cpu) | |
3953 | return 1; | |
3954 | } else { | |
7d1e6a9b | 3955 | if (!cpumask_test_cpu(cpu, nohz.cpu_mask)) |
46cb4b7c SS |
3956 | return 0; |
3957 | ||
7d1e6a9b | 3958 | cpumask_clear_cpu(cpu, nohz.cpu_mask); |
46cb4b7c SS |
3959 | |
3960 | if (atomic_read(&nohz.load_balancer) == cpu) | |
3961 | if (atomic_cmpxchg(&nohz.load_balancer, cpu, -1) != cpu) | |
3962 | BUG(); | |
3963 | } | |
3964 | return 0; | |
3965 | } | |
3966 | #endif | |
3967 | ||
3968 | static DEFINE_SPINLOCK(balancing); | |
3969 | ||
3970 | /* | |
7835b98b CL |
3971 | * It checks each scheduling domain to see if it is due to be balanced, |
3972 | * and initiates a balancing operation if so. | |
3973 | * | |
3974 | * Balancing parameters are set up in arch_init_sched_domains. | |
3975 | */ | |
a9957449 | 3976 | static void rebalance_domains(int cpu, enum cpu_idle_type idle) |
7835b98b | 3977 | { |
46cb4b7c SS |
3978 | int balance = 1; |
3979 | struct rq *rq = cpu_rq(cpu); | |
7835b98b CL |
3980 | unsigned long interval; |
3981 | struct sched_domain *sd; | |
46cb4b7c | 3982 | /* Earliest time when we have to do rebalance again */ |
c9819f45 | 3983 | unsigned long next_balance = jiffies + 60*HZ; |
f549da84 | 3984 | int update_next_balance = 0; |
d07355f5 | 3985 | int need_serialize; |
a0e90245 RR |
3986 | cpumask_var_t tmp; |
3987 | ||
3988 | /* Fails alloc? Rebalancing probably not a priority right now. */ | |
3989 | if (!alloc_cpumask_var(&tmp, GFP_ATOMIC)) | |
3990 | return; | |
1da177e4 | 3991 | |
46cb4b7c | 3992 | for_each_domain(cpu, sd) { |
1da177e4 LT |
3993 | if (!(sd->flags & SD_LOAD_BALANCE)) |
3994 | continue; | |
3995 | ||
3996 | interval = sd->balance_interval; | |
d15bcfdb | 3997 | if (idle != CPU_IDLE) |
1da177e4 LT |
3998 | interval *= sd->busy_factor; |
3999 | ||
4000 | /* scale ms to jiffies */ | |
4001 | interval = msecs_to_jiffies(interval); | |
4002 | if (unlikely(!interval)) | |
4003 | interval = 1; | |
dd41f596 IM |
4004 | if (interval > HZ*NR_CPUS/10) |
4005 | interval = HZ*NR_CPUS/10; | |
4006 | ||
d07355f5 | 4007 | need_serialize = sd->flags & SD_SERIALIZE; |
1da177e4 | 4008 | |
d07355f5 | 4009 | if (need_serialize) { |
08c183f3 CL |
4010 | if (!spin_trylock(&balancing)) |
4011 | goto out; | |
4012 | } | |
4013 | ||
c9819f45 | 4014 | if (time_after_eq(jiffies, sd->last_balance + interval)) { |
a0e90245 | 4015 | if (load_balance(cpu, rq, sd, idle, &balance, tmp)) { |
fa3b6ddc SS |
4016 | /* |
4017 | * We've pulled tasks over so either we're no | |
5969fe06 NP |
4018 | * longer idle, or one of our SMT siblings is |
4019 | * not idle. | |
4020 | */ | |
d15bcfdb | 4021 | idle = CPU_NOT_IDLE; |
1da177e4 | 4022 | } |
1bd77f2d | 4023 | sd->last_balance = jiffies; |
1da177e4 | 4024 | } |
d07355f5 | 4025 | if (need_serialize) |
08c183f3 CL |
4026 | spin_unlock(&balancing); |
4027 | out: | |
f549da84 | 4028 | if (time_after(next_balance, sd->last_balance + interval)) { |
c9819f45 | 4029 | next_balance = sd->last_balance + interval; |
f549da84 SS |
4030 | update_next_balance = 1; |
4031 | } | |
783609c6 SS |
4032 | |
4033 | /* | |
4034 | * Stop the load balance at this level. There is another | |
4035 | * CPU in our sched group which is doing load balancing more | |
4036 | * actively. | |
4037 | */ | |
4038 | if (!balance) | |
4039 | break; | |
1da177e4 | 4040 | } |
f549da84 SS |
4041 | |
4042 | /* | |
4043 | * next_balance will be updated only when there is a need. | |
4044 | * When the cpu is attached to null domain for ex, it will not be | |
4045 | * updated. | |
4046 | */ | |
4047 | if (likely(update_next_balance)) | |
4048 | rq->next_balance = next_balance; | |
a0e90245 RR |
4049 | |
4050 | free_cpumask_var(tmp); | |
46cb4b7c SS |
4051 | } |
4052 | ||
4053 | /* | |
4054 | * run_rebalance_domains is triggered when needed from the scheduler tick. | |
4055 | * In CONFIG_NO_HZ case, the idle load balance owner will do the | |
4056 | * rebalancing for all the cpus for whom scheduler ticks are stopped. | |
4057 | */ | |
4058 | static void run_rebalance_domains(struct softirq_action *h) | |
4059 | { | |
dd41f596 IM |
4060 | int this_cpu = smp_processor_id(); |
4061 | struct rq *this_rq = cpu_rq(this_cpu); | |
4062 | enum cpu_idle_type idle = this_rq->idle_at_tick ? | |
4063 | CPU_IDLE : CPU_NOT_IDLE; | |
46cb4b7c | 4064 | |
dd41f596 | 4065 | rebalance_domains(this_cpu, idle); |
46cb4b7c SS |
4066 | |
4067 | #ifdef CONFIG_NO_HZ | |
4068 | /* | |
4069 | * If this cpu is the owner for idle load balancing, then do the | |
4070 | * balancing on behalf of the other idle cpus whose ticks are | |
4071 | * stopped. | |
4072 | */ | |
dd41f596 IM |
4073 | if (this_rq->idle_at_tick && |
4074 | atomic_read(&nohz.load_balancer) == this_cpu) { | |
46cb4b7c SS |
4075 | struct rq *rq; |
4076 | int balance_cpu; | |
4077 | ||
7d1e6a9b RR |
4078 | for_each_cpu(balance_cpu, nohz.cpu_mask) { |
4079 | if (balance_cpu == this_cpu) | |
4080 | continue; | |
4081 | ||
46cb4b7c SS |
4082 | /* |
4083 | * If this cpu gets work to do, stop the load balancing | |
4084 | * work being done for other cpus. Next load | |
4085 | * balancing owner will pick it up. | |
4086 | */ | |
4087 | if (need_resched()) | |
4088 | break; | |
4089 | ||
de0cf899 | 4090 | rebalance_domains(balance_cpu, CPU_IDLE); |
46cb4b7c SS |
4091 | |
4092 | rq = cpu_rq(balance_cpu); | |
dd41f596 IM |
4093 | if (time_after(this_rq->next_balance, rq->next_balance)) |
4094 | this_rq->next_balance = rq->next_balance; | |
46cb4b7c SS |
4095 | } |
4096 | } | |
4097 | #endif | |
4098 | } | |
4099 | ||
4100 | /* | |
4101 | * Trigger the SCHED_SOFTIRQ if it is time to do periodic load balancing. | |
4102 | * | |
4103 | * In case of CONFIG_NO_HZ, this is the place where we nominate a new | |
4104 | * idle load balancing owner or decide to stop the periodic load balancing, | |
4105 | * if the whole system is idle. | |
4106 | */ | |
dd41f596 | 4107 | static inline void trigger_load_balance(struct rq *rq, int cpu) |
46cb4b7c | 4108 | { |
46cb4b7c SS |
4109 | #ifdef CONFIG_NO_HZ |
4110 | /* | |
4111 | * If we were in the nohz mode recently and busy at the current | |
4112 | * scheduler tick, then check if we need to nominate new idle | |
4113 | * load balancer. | |
4114 | */ | |
4115 | if (rq->in_nohz_recently && !rq->idle_at_tick) { | |
4116 | rq->in_nohz_recently = 0; | |
4117 | ||
4118 | if (atomic_read(&nohz.load_balancer) == cpu) { | |
7d1e6a9b | 4119 | cpumask_clear_cpu(cpu, nohz.cpu_mask); |
46cb4b7c SS |
4120 | atomic_set(&nohz.load_balancer, -1); |
4121 | } | |
4122 | ||
4123 | if (atomic_read(&nohz.load_balancer) == -1) { | |
4124 | /* | |
4125 | * simple selection for now: Nominate the | |
4126 | * first cpu in the nohz list to be the next | |
4127 | * ilb owner. | |
4128 | * | |
4129 | * TBD: Traverse the sched domains and nominate | |
4130 | * the nearest cpu in the nohz.cpu_mask. | |
4131 | */ | |
7d1e6a9b | 4132 | int ilb = cpumask_first(nohz.cpu_mask); |
46cb4b7c | 4133 | |
434d53b0 | 4134 | if (ilb < nr_cpu_ids) |
46cb4b7c SS |
4135 | resched_cpu(ilb); |
4136 | } | |
4137 | } | |
4138 | ||
4139 | /* | |
4140 | * If this cpu is idle and doing idle load balancing for all the | |
4141 | * cpus with ticks stopped, is it time for that to stop? | |
4142 | */ | |
4143 | if (rq->idle_at_tick && atomic_read(&nohz.load_balancer) == cpu && | |
7d1e6a9b | 4144 | cpumask_weight(nohz.cpu_mask) == num_online_cpus()) { |
46cb4b7c SS |
4145 | resched_cpu(cpu); |
4146 | return; | |
4147 | } | |
4148 | ||
4149 | /* | |
4150 | * If this cpu is idle and the idle load balancing is done by | |
4151 | * someone else, then no need raise the SCHED_SOFTIRQ | |
4152 | */ | |
4153 | if (rq->idle_at_tick && atomic_read(&nohz.load_balancer) != cpu && | |
7d1e6a9b | 4154 | cpumask_test_cpu(cpu, nohz.cpu_mask)) |
46cb4b7c SS |
4155 | return; |
4156 | #endif | |
4157 | if (time_after_eq(jiffies, rq->next_balance)) | |
4158 | raise_softirq(SCHED_SOFTIRQ); | |
1da177e4 | 4159 | } |
dd41f596 IM |
4160 | |
4161 | #else /* CONFIG_SMP */ | |
4162 | ||
1da177e4 LT |
4163 | /* |
4164 | * on UP we do not need to balance between CPUs: | |
4165 | */ | |
70b97a7f | 4166 | static inline void idle_balance(int cpu, struct rq *rq) |
1da177e4 LT |
4167 | { |
4168 | } | |
dd41f596 | 4169 | |
1da177e4 LT |
4170 | #endif |
4171 | ||
1da177e4 LT |
4172 | DEFINE_PER_CPU(struct kernel_stat, kstat); |
4173 | ||
4174 | EXPORT_PER_CPU_SYMBOL(kstat); | |
4175 | ||
aa9c4c0f IM |
4176 | /* |
4177 | * Return any ns on the sched_clock that have not yet been banked in | |
4178 | * @p in case that task is currently running. | |
4179 | */ | |
4180 | unsigned long long __task_delta_exec(struct task_struct *p, int update) | |
4181 | { | |
4182 | s64 delta_exec; | |
4183 | struct rq *rq; | |
4184 | ||
4185 | rq = task_rq(p); | |
4186 | WARN_ON_ONCE(!runqueue_is_locked()); | |
4187 | WARN_ON_ONCE(!task_current(rq, p)); | |
4188 | ||
4189 | if (update) | |
4190 | update_rq_clock(rq); | |
4191 | ||
4192 | delta_exec = rq->clock - p->se.exec_start; | |
4193 | ||
4194 | WARN_ON_ONCE(delta_exec < 0); | |
4195 | ||
4196 | return delta_exec; | |
4197 | } | |
4198 | ||
1da177e4 | 4199 | /* |
f06febc9 FM |
4200 | * Return any ns on the sched_clock that have not yet been banked in |
4201 | * @p in case that task is currently running. | |
1da177e4 | 4202 | */ |
bb34d92f | 4203 | unsigned long long task_delta_exec(struct task_struct *p) |
1da177e4 | 4204 | { |
1da177e4 | 4205 | unsigned long flags; |
41b86e9c | 4206 | struct rq *rq; |
bb34d92f | 4207 | u64 ns = 0; |
48f24c4d | 4208 | |
41b86e9c | 4209 | rq = task_rq_lock(p, &flags); |
1508487e | 4210 | |
051a1d1a | 4211 | if (task_current(rq, p)) { |
f06febc9 FM |
4212 | u64 delta_exec; |
4213 | ||
a8e504d2 IM |
4214 | update_rq_clock(rq); |
4215 | delta_exec = rq->clock - p->se.exec_start; | |
41b86e9c | 4216 | if ((s64)delta_exec > 0) |
bb34d92f | 4217 | ns = delta_exec; |
41b86e9c | 4218 | } |
48f24c4d | 4219 | |
41b86e9c | 4220 | task_rq_unlock(rq, &flags); |
48f24c4d | 4221 | |
1da177e4 LT |
4222 | return ns; |
4223 | } | |
4224 | ||
1da177e4 LT |
4225 | /* |
4226 | * Account user cpu time to a process. | |
4227 | * @p: the process that the cpu time gets accounted to | |
1da177e4 | 4228 | * @cputime: the cpu time spent in user space since the last update |
457533a7 | 4229 | * @cputime_scaled: cputime scaled by cpu frequency |
1da177e4 | 4230 | */ |
457533a7 MS |
4231 | void account_user_time(struct task_struct *p, cputime_t cputime, |
4232 | cputime_t cputime_scaled) | |
1da177e4 LT |
4233 | { |
4234 | struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat; | |
4235 | cputime64_t tmp; | |
4236 | ||
457533a7 | 4237 | /* Add user time to process. */ |
1da177e4 | 4238 | p->utime = cputime_add(p->utime, cputime); |
457533a7 | 4239 | p->utimescaled = cputime_add(p->utimescaled, cputime_scaled); |
f06febc9 | 4240 | account_group_user_time(p, cputime); |
1da177e4 LT |
4241 | |
4242 | /* Add user time to cpustat. */ | |
4243 | tmp = cputime_to_cputime64(cputime); | |
4244 | if (TASK_NICE(p) > 0) | |
4245 | cpustat->nice = cputime64_add(cpustat->nice, tmp); | |
4246 | else | |
4247 | cpustat->user = cputime64_add(cpustat->user, tmp); | |
49b5cf34 JL |
4248 | /* Account for user time used */ |
4249 | acct_update_integrals(p); | |
1da177e4 LT |
4250 | } |
4251 | ||
94886b84 LV |
4252 | /* |
4253 | * Account guest cpu time to a process. | |
4254 | * @p: the process that the cpu time gets accounted to | |
4255 | * @cputime: the cpu time spent in virtual machine since the last update | |
457533a7 | 4256 | * @cputime_scaled: cputime scaled by cpu frequency |
94886b84 | 4257 | */ |
457533a7 MS |
4258 | static void account_guest_time(struct task_struct *p, cputime_t cputime, |
4259 | cputime_t cputime_scaled) | |
94886b84 LV |
4260 | { |
4261 | cputime64_t tmp; | |
4262 | struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat; | |
4263 | ||
4264 | tmp = cputime_to_cputime64(cputime); | |
4265 | ||
457533a7 | 4266 | /* Add guest time to process. */ |
94886b84 | 4267 | p->utime = cputime_add(p->utime, cputime); |
457533a7 | 4268 | p->utimescaled = cputime_add(p->utimescaled, cputime_scaled); |
f06febc9 | 4269 | account_group_user_time(p, cputime); |
94886b84 LV |
4270 | p->gtime = cputime_add(p->gtime, cputime); |
4271 | ||
457533a7 | 4272 | /* Add guest time to cpustat. */ |
94886b84 LV |
4273 | cpustat->user = cputime64_add(cpustat->user, tmp); |
4274 | cpustat->guest = cputime64_add(cpustat->guest, tmp); | |
4275 | } | |
4276 | ||
1da177e4 LT |
4277 | /* |
4278 | * Account system cpu time to a process. | |
4279 | * @p: the process that the cpu time gets accounted to | |
4280 | * @hardirq_offset: the offset to subtract from hardirq_count() | |
4281 | * @cputime: the cpu time spent in kernel space since the last update | |
457533a7 | 4282 | * @cputime_scaled: cputime scaled by cpu frequency |
1da177e4 LT |
4283 | */ |
4284 | void account_system_time(struct task_struct *p, int hardirq_offset, | |
457533a7 | 4285 | cputime_t cputime, cputime_t cputime_scaled) |
1da177e4 LT |
4286 | { |
4287 | struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat; | |
1da177e4 LT |
4288 | cputime64_t tmp; |
4289 | ||
983ed7a6 | 4290 | if ((p->flags & PF_VCPU) && (irq_count() - hardirq_offset == 0)) { |
457533a7 | 4291 | account_guest_time(p, cputime, cputime_scaled); |
983ed7a6 HH |
4292 | return; |
4293 | } | |
94886b84 | 4294 | |
457533a7 | 4295 | /* Add system time to process. */ |
1da177e4 | 4296 | p->stime = cputime_add(p->stime, cputime); |
457533a7 | 4297 | p->stimescaled = cputime_add(p->stimescaled, cputime_scaled); |
f06febc9 | 4298 | account_group_system_time(p, cputime); |
1da177e4 LT |
4299 | |
4300 | /* Add system time to cpustat. */ | |
4301 | tmp = cputime_to_cputime64(cputime); | |
4302 | if (hardirq_count() - hardirq_offset) | |
4303 | cpustat->irq = cputime64_add(cpustat->irq, tmp); | |
4304 | else if (softirq_count()) | |
4305 | cpustat->softirq = cputime64_add(cpustat->softirq, tmp); | |
1da177e4 | 4306 | else |
79741dd3 MS |
4307 | cpustat->system = cputime64_add(cpustat->system, tmp); |
4308 | ||
1da177e4 LT |
4309 | /* Account for system time used */ |
4310 | acct_update_integrals(p); | |
1da177e4 LT |
4311 | } |
4312 | ||
c66f08be | 4313 | /* |
1da177e4 | 4314 | * Account for involuntary wait time. |
1da177e4 | 4315 | * @steal: the cpu time spent in involuntary wait |
c66f08be | 4316 | */ |
79741dd3 | 4317 | void account_steal_time(cputime_t cputime) |
c66f08be | 4318 | { |
79741dd3 MS |
4319 | struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat; |
4320 | cputime64_t cputime64 = cputime_to_cputime64(cputime); | |
4321 | ||
4322 | cpustat->steal = cputime64_add(cpustat->steal, cputime64); | |
c66f08be MN |
4323 | } |
4324 | ||
1da177e4 | 4325 | /* |
79741dd3 MS |
4326 | * Account for idle time. |
4327 | * @cputime: the cpu time spent in idle wait | |
1da177e4 | 4328 | */ |
79741dd3 | 4329 | void account_idle_time(cputime_t cputime) |
1da177e4 LT |
4330 | { |
4331 | struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat; | |
79741dd3 | 4332 | cputime64_t cputime64 = cputime_to_cputime64(cputime); |
70b97a7f | 4333 | struct rq *rq = this_rq(); |
1da177e4 | 4334 | |
79741dd3 MS |
4335 | if (atomic_read(&rq->nr_iowait) > 0) |
4336 | cpustat->iowait = cputime64_add(cpustat->iowait, cputime64); | |
4337 | else | |
4338 | cpustat->idle = cputime64_add(cpustat->idle, cputime64); | |
1da177e4 LT |
4339 | } |
4340 | ||
79741dd3 MS |
4341 | #ifndef CONFIG_VIRT_CPU_ACCOUNTING |
4342 | ||
4343 | /* | |
4344 | * Account a single tick of cpu time. | |
4345 | * @p: the process that the cpu time gets accounted to | |
4346 | * @user_tick: indicates if the tick is a user or a system tick | |
4347 | */ | |
4348 | void account_process_tick(struct task_struct *p, int user_tick) | |
4349 | { | |
4350 | cputime_t one_jiffy = jiffies_to_cputime(1); | |
4351 | cputime_t one_jiffy_scaled = cputime_to_scaled(one_jiffy); | |
4352 | struct rq *rq = this_rq(); | |
4353 | ||
4354 | if (user_tick) | |
4355 | account_user_time(p, one_jiffy, one_jiffy_scaled); | |
4356 | else if (p != rq->idle) | |
4357 | account_system_time(p, HARDIRQ_OFFSET, one_jiffy, | |
4358 | one_jiffy_scaled); | |
4359 | else | |
4360 | account_idle_time(one_jiffy); | |
4361 | } | |
4362 | ||
4363 | /* | |
4364 | * Account multiple ticks of steal time. | |
4365 | * @p: the process from which the cpu time has been stolen | |
4366 | * @ticks: number of stolen ticks | |
4367 | */ | |
4368 | void account_steal_ticks(unsigned long ticks) | |
4369 | { | |
4370 | account_steal_time(jiffies_to_cputime(ticks)); | |
4371 | } | |
4372 | ||
4373 | /* | |
4374 | * Account multiple ticks of idle time. | |
4375 | * @ticks: number of stolen ticks | |
4376 | */ | |
4377 | void account_idle_ticks(unsigned long ticks) | |
4378 | { | |
4379 | account_idle_time(jiffies_to_cputime(ticks)); | |
1da177e4 LT |
4380 | } |
4381 | ||
79741dd3 MS |
4382 | #endif |
4383 | ||
49048622 BS |
4384 | /* |
4385 | * Use precise platform statistics if available: | |
4386 | */ | |
4387 | #ifdef CONFIG_VIRT_CPU_ACCOUNTING | |
4388 | cputime_t task_utime(struct task_struct *p) | |
4389 | { | |
4390 | return p->utime; | |
4391 | } | |
4392 | ||
4393 | cputime_t task_stime(struct task_struct *p) | |
4394 | { | |
4395 | return p->stime; | |
4396 | } | |
4397 | #else | |
4398 | cputime_t task_utime(struct task_struct *p) | |
4399 | { | |
4400 | clock_t utime = cputime_to_clock_t(p->utime), | |
4401 | total = utime + cputime_to_clock_t(p->stime); | |
4402 | u64 temp; | |
4403 | ||
4404 | /* | |
4405 | * Use CFS's precise accounting: | |
4406 | */ | |
4407 | temp = (u64)nsec_to_clock_t(p->se.sum_exec_runtime); | |
4408 | ||
4409 | if (total) { | |
4410 | temp *= utime; | |
4411 | do_div(temp, total); | |
4412 | } | |
4413 | utime = (clock_t)temp; | |
4414 | ||
4415 | p->prev_utime = max(p->prev_utime, clock_t_to_cputime(utime)); | |
4416 | return p->prev_utime; | |
4417 | } | |
4418 | ||
4419 | cputime_t task_stime(struct task_struct *p) | |
4420 | { | |
4421 | clock_t stime; | |
4422 | ||
4423 | /* | |
4424 | * Use CFS's precise accounting. (we subtract utime from | |
4425 | * the total, to make sure the total observed by userspace | |
4426 | * grows monotonically - apps rely on that): | |
4427 | */ | |
4428 | stime = nsec_to_clock_t(p->se.sum_exec_runtime) - | |
4429 | cputime_to_clock_t(task_utime(p)); | |
4430 | ||
4431 | if (stime >= 0) | |
4432 | p->prev_stime = max(p->prev_stime, clock_t_to_cputime(stime)); | |
4433 | ||
4434 | return p->prev_stime; | |
4435 | } | |
4436 | #endif | |
4437 | ||
4438 | inline cputime_t task_gtime(struct task_struct *p) | |
4439 | { | |
4440 | return p->gtime; | |
4441 | } | |
4442 | ||
7835b98b CL |
4443 | /* |
4444 | * This function gets called by the timer code, with HZ frequency. | |
4445 | * We call it with interrupts disabled. | |
4446 | * | |
4447 | * It also gets called by the fork code, when changing the parent's | |
4448 | * timeslices. | |
4449 | */ | |
4450 | void scheduler_tick(void) | |
4451 | { | |
7835b98b CL |
4452 | int cpu = smp_processor_id(); |
4453 | struct rq *rq = cpu_rq(cpu); | |
dd41f596 | 4454 | struct task_struct *curr = rq->curr; |
3e51f33f PZ |
4455 | |
4456 | sched_clock_tick(); | |
dd41f596 IM |
4457 | |
4458 | spin_lock(&rq->lock); | |
3e51f33f | 4459 | update_rq_clock(rq); |
f1a438d8 | 4460 | update_cpu_load(rq); |
fa85ae24 | 4461 | curr->sched_class->task_tick(rq, curr, 0); |
aa9c4c0f | 4462 | perf_counter_task_tick(curr, cpu); |
dd41f596 | 4463 | spin_unlock(&rq->lock); |
7835b98b | 4464 | |
e418e1c2 | 4465 | #ifdef CONFIG_SMP |
dd41f596 IM |
4466 | rq->idle_at_tick = idle_cpu(cpu); |
4467 | trigger_load_balance(rq, cpu); | |
e418e1c2 | 4468 | #endif |
1da177e4 LT |
4469 | } |
4470 | ||
6cd8a4bb SR |
4471 | #if defined(CONFIG_PREEMPT) && (defined(CONFIG_DEBUG_PREEMPT) || \ |
4472 | defined(CONFIG_PREEMPT_TRACER)) | |
4473 | ||
4474 | static inline unsigned long get_parent_ip(unsigned long addr) | |
4475 | { | |
4476 | if (in_lock_functions(addr)) { | |
4477 | addr = CALLER_ADDR2; | |
4478 | if (in_lock_functions(addr)) | |
4479 | addr = CALLER_ADDR3; | |
4480 | } | |
4481 | return addr; | |
4482 | } | |
1da177e4 | 4483 | |
43627582 | 4484 | void __kprobes add_preempt_count(int val) |
1da177e4 | 4485 | { |
6cd8a4bb | 4486 | #ifdef CONFIG_DEBUG_PREEMPT |
1da177e4 LT |
4487 | /* |
4488 | * Underflow? | |
4489 | */ | |
9a11b49a IM |
4490 | if (DEBUG_LOCKS_WARN_ON((preempt_count() < 0))) |
4491 | return; | |
6cd8a4bb | 4492 | #endif |
1da177e4 | 4493 | preempt_count() += val; |
6cd8a4bb | 4494 | #ifdef CONFIG_DEBUG_PREEMPT |
1da177e4 LT |
4495 | /* |
4496 | * Spinlock count overflowing soon? | |
4497 | */ | |
33859f7f MOS |
4498 | DEBUG_LOCKS_WARN_ON((preempt_count() & PREEMPT_MASK) >= |
4499 | PREEMPT_MASK - 10); | |
6cd8a4bb SR |
4500 | #endif |
4501 | if (preempt_count() == val) | |
4502 | trace_preempt_off(CALLER_ADDR0, get_parent_ip(CALLER_ADDR1)); | |
1da177e4 LT |
4503 | } |
4504 | EXPORT_SYMBOL(add_preempt_count); | |
4505 | ||
43627582 | 4506 | void __kprobes sub_preempt_count(int val) |
1da177e4 | 4507 | { |
6cd8a4bb | 4508 | #ifdef CONFIG_DEBUG_PREEMPT |
1da177e4 LT |
4509 | /* |
4510 | * Underflow? | |
4511 | */ | |
01e3eb82 | 4512 | if (DEBUG_LOCKS_WARN_ON(val > preempt_count())) |
9a11b49a | 4513 | return; |
1da177e4 LT |
4514 | /* |
4515 | * Is the spinlock portion underflowing? | |
4516 | */ | |
9a11b49a IM |
4517 | if (DEBUG_LOCKS_WARN_ON((val < PREEMPT_MASK) && |
4518 | !(preempt_count() & PREEMPT_MASK))) | |
4519 | return; | |
6cd8a4bb | 4520 | #endif |
9a11b49a | 4521 | |
6cd8a4bb SR |
4522 | if (preempt_count() == val) |
4523 | trace_preempt_on(CALLER_ADDR0, get_parent_ip(CALLER_ADDR1)); | |
1da177e4 LT |
4524 | preempt_count() -= val; |
4525 | } | |
4526 | EXPORT_SYMBOL(sub_preempt_count); | |
4527 | ||
4528 | #endif | |
4529 | ||
4530 | /* | |
dd41f596 | 4531 | * Print scheduling while atomic bug: |
1da177e4 | 4532 | */ |
dd41f596 | 4533 | static noinline void __schedule_bug(struct task_struct *prev) |
1da177e4 | 4534 | { |
838225b4 SS |
4535 | struct pt_regs *regs = get_irq_regs(); |
4536 | ||
4537 | printk(KERN_ERR "BUG: scheduling while atomic: %s/%d/0x%08x\n", | |
4538 | prev->comm, prev->pid, preempt_count()); | |
4539 | ||
dd41f596 | 4540 | debug_show_held_locks(prev); |
e21f5b15 | 4541 | print_modules(); |
dd41f596 IM |
4542 | if (irqs_disabled()) |
4543 | print_irqtrace_events(prev); | |
838225b4 SS |
4544 | |
4545 | if (regs) | |
4546 | show_regs(regs); | |
4547 | else | |
4548 | dump_stack(); | |
dd41f596 | 4549 | } |
1da177e4 | 4550 | |
dd41f596 IM |
4551 | /* |
4552 | * Various schedule()-time debugging checks and statistics: | |
4553 | */ | |
4554 | static inline void schedule_debug(struct task_struct *prev) | |
4555 | { | |
1da177e4 | 4556 | /* |
41a2d6cf | 4557 | * Test if we are atomic. Since do_exit() needs to call into |
1da177e4 LT |
4558 | * schedule() atomically, we ignore that path for now. |
4559 | * Otherwise, whine if we are scheduling when we should not be. | |
4560 | */ | |
3f33a7ce | 4561 | if (unlikely(in_atomic_preempt_off() && !prev->exit_state)) |
dd41f596 IM |
4562 | __schedule_bug(prev); |
4563 | ||
1da177e4 LT |
4564 | profile_hit(SCHED_PROFILING, __builtin_return_address(0)); |
4565 | ||
2d72376b | 4566 | schedstat_inc(this_rq(), sched_count); |
b8efb561 IM |
4567 | #ifdef CONFIG_SCHEDSTATS |
4568 | if (unlikely(prev->lock_depth >= 0)) { | |
2d72376b IM |
4569 | schedstat_inc(this_rq(), bkl_count); |
4570 | schedstat_inc(prev, sched_info.bkl_count); | |
b8efb561 IM |
4571 | } |
4572 | #endif | |
dd41f596 IM |
4573 | } |
4574 | ||
4575 | /* | |
4576 | * Pick up the highest-prio task: | |
4577 | */ | |
4578 | static inline struct task_struct * | |
ff95f3df | 4579 | pick_next_task(struct rq *rq, struct task_struct *prev) |
dd41f596 | 4580 | { |
5522d5d5 | 4581 | const struct sched_class *class; |
dd41f596 | 4582 | struct task_struct *p; |
1da177e4 LT |
4583 | |
4584 | /* | |
dd41f596 IM |
4585 | * Optimization: we know that if all tasks are in |
4586 | * the fair class we can call that function directly: | |
1da177e4 | 4587 | */ |
dd41f596 | 4588 | if (likely(rq->nr_running == rq->cfs.nr_running)) { |
fb8d4724 | 4589 | p = fair_sched_class.pick_next_task(rq); |
dd41f596 IM |
4590 | if (likely(p)) |
4591 | return p; | |
1da177e4 LT |
4592 | } |
4593 | ||
dd41f596 IM |
4594 | class = sched_class_highest; |
4595 | for ( ; ; ) { | |
fb8d4724 | 4596 | p = class->pick_next_task(rq); |
dd41f596 IM |
4597 | if (p) |
4598 | return p; | |
4599 | /* | |
4600 | * Will never be NULL as the idle class always | |
4601 | * returns a non-NULL p: | |
4602 | */ | |
4603 | class = class->next; | |
4604 | } | |
4605 | } | |
1da177e4 | 4606 | |
dd41f596 IM |
4607 | /* |
4608 | * schedule() is the main scheduler function. | |
4609 | */ | |
4610 | asmlinkage void __sched schedule(void) | |
4611 | { | |
4612 | struct task_struct *prev, *next; | |
67ca7bde | 4613 | unsigned long *switch_count; |
dd41f596 | 4614 | struct rq *rq; |
31656519 | 4615 | int cpu; |
dd41f596 IM |
4616 | |
4617 | need_resched: | |
4618 | preempt_disable(); | |
4619 | cpu = smp_processor_id(); | |
4620 | rq = cpu_rq(cpu); | |
4621 | rcu_qsctr_inc(cpu); | |
4622 | prev = rq->curr; | |
4623 | switch_count = &prev->nivcsw; | |
4624 | ||
4625 | release_kernel_lock(prev); | |
4626 | need_resched_nonpreemptible: | |
4627 | ||
4628 | schedule_debug(prev); | |
1da177e4 | 4629 | |
31656519 | 4630 | if (sched_feat(HRTICK)) |
f333fdc9 | 4631 | hrtick_clear(rq); |
8f4d37ec | 4632 | |
8cd162ce | 4633 | spin_lock_irq(&rq->lock); |
3e51f33f | 4634 | update_rq_clock(rq); |
1e819950 | 4635 | clear_tsk_need_resched(prev); |
1da177e4 | 4636 | |
1da177e4 | 4637 | if (prev->state && !(preempt_count() & PREEMPT_ACTIVE)) { |
16882c1e | 4638 | if (unlikely(signal_pending_state(prev->state, prev))) |
1da177e4 | 4639 | prev->state = TASK_RUNNING; |
16882c1e | 4640 | else |
2e1cb74a | 4641 | deactivate_task(rq, prev, 1); |
dd41f596 | 4642 | switch_count = &prev->nvcsw; |
1da177e4 LT |
4643 | } |
4644 | ||
9a897c5a SR |
4645 | #ifdef CONFIG_SMP |
4646 | if (prev->sched_class->pre_schedule) | |
4647 | prev->sched_class->pre_schedule(rq, prev); | |
4648 | #endif | |
f65eda4f | 4649 | |
dd41f596 | 4650 | if (unlikely(!rq->nr_running)) |
1da177e4 | 4651 | idle_balance(cpu, rq); |
1da177e4 | 4652 | |
31ee529c | 4653 | prev->sched_class->put_prev_task(rq, prev); |
ff95f3df | 4654 | next = pick_next_task(rq, prev); |
1da177e4 | 4655 | |
1da177e4 | 4656 | if (likely(prev != next)) { |
673a90a1 | 4657 | sched_info_switch(prev, next); |
aa9c4c0f | 4658 | perf_counter_task_sched_out(prev, cpu); |
673a90a1 | 4659 | |
1da177e4 LT |
4660 | rq->nr_switches++; |
4661 | rq->curr = next; | |
4662 | ++*switch_count; | |
4663 | ||
dd41f596 | 4664 | context_switch(rq, prev, next); /* unlocks the rq */ |
8f4d37ec PZ |
4665 | /* |
4666 | * the context switch might have flipped the stack from under | |
4667 | * us, hence refresh the local variables. | |
4668 | */ | |
4669 | cpu = smp_processor_id(); | |
4670 | rq = cpu_rq(cpu); | |
1da177e4 LT |
4671 | } else |
4672 | spin_unlock_irq(&rq->lock); | |
4673 | ||
8f4d37ec | 4674 | if (unlikely(reacquire_kernel_lock(current) < 0)) |
1da177e4 | 4675 | goto need_resched_nonpreemptible; |
8f4d37ec | 4676 | |
1da177e4 LT |
4677 | preempt_enable_no_resched(); |
4678 | if (unlikely(test_thread_flag(TIF_NEED_RESCHED))) | |
4679 | goto need_resched; | |
4680 | } | |
1da177e4 LT |
4681 | EXPORT_SYMBOL(schedule); |
4682 | ||
4683 | #ifdef CONFIG_PREEMPT | |
4684 | /* | |
2ed6e34f | 4685 | * this is the entry point to schedule() from in-kernel preemption |
41a2d6cf | 4686 | * off of preempt_enable. Kernel preemptions off return from interrupt |
1da177e4 LT |
4687 | * occur there and call schedule directly. |
4688 | */ | |
4689 | asmlinkage void __sched preempt_schedule(void) | |
4690 | { | |
4691 | struct thread_info *ti = current_thread_info(); | |
6478d880 | 4692 | |
1da177e4 LT |
4693 | /* |
4694 | * If there is a non-zero preempt_count or interrupts are disabled, | |
41a2d6cf | 4695 | * we do not want to preempt the current task. Just return.. |
1da177e4 | 4696 | */ |
beed33a8 | 4697 | if (likely(ti->preempt_count || irqs_disabled())) |
1da177e4 LT |
4698 | return; |
4699 | ||
3a5c359a AK |
4700 | do { |
4701 | add_preempt_count(PREEMPT_ACTIVE); | |
3a5c359a | 4702 | schedule(); |
3a5c359a | 4703 | sub_preempt_count(PREEMPT_ACTIVE); |
1da177e4 | 4704 | |
3a5c359a AK |
4705 | /* |
4706 | * Check again in case we missed a preemption opportunity | |
4707 | * between schedule and now. | |
4708 | */ | |
4709 | barrier(); | |
4710 | } while (unlikely(test_thread_flag(TIF_NEED_RESCHED))); | |
1da177e4 | 4711 | } |
1da177e4 LT |
4712 | EXPORT_SYMBOL(preempt_schedule); |
4713 | ||
4714 | /* | |
2ed6e34f | 4715 | * this is the entry point to schedule() from kernel preemption |
1da177e4 LT |
4716 | * off of irq context. |
4717 | * Note, that this is called and return with irqs disabled. This will | |
4718 | * protect us against recursive calling from irq. | |
4719 | */ | |
4720 | asmlinkage void __sched preempt_schedule_irq(void) | |
4721 | { | |
4722 | struct thread_info *ti = current_thread_info(); | |
6478d880 | 4723 | |
2ed6e34f | 4724 | /* Catch callers which need to be fixed */ |
1da177e4 LT |
4725 | BUG_ON(ti->preempt_count || !irqs_disabled()); |
4726 | ||
3a5c359a AK |
4727 | do { |
4728 | add_preempt_count(PREEMPT_ACTIVE); | |
3a5c359a AK |
4729 | local_irq_enable(); |
4730 | schedule(); | |
4731 | local_irq_disable(); | |
3a5c359a | 4732 | sub_preempt_count(PREEMPT_ACTIVE); |
1da177e4 | 4733 | |
3a5c359a AK |
4734 | /* |
4735 | * Check again in case we missed a preemption opportunity | |
4736 | * between schedule and now. | |
4737 | */ | |
4738 | barrier(); | |
4739 | } while (unlikely(test_thread_flag(TIF_NEED_RESCHED))); | |
1da177e4 LT |
4740 | } |
4741 | ||
4742 | #endif /* CONFIG_PREEMPT */ | |
4743 | ||
95cdf3b7 IM |
4744 | int default_wake_function(wait_queue_t *curr, unsigned mode, int sync, |
4745 | void *key) | |
1da177e4 | 4746 | { |
48f24c4d | 4747 | return try_to_wake_up(curr->private, mode, sync); |
1da177e4 | 4748 | } |
1da177e4 LT |
4749 | EXPORT_SYMBOL(default_wake_function); |
4750 | ||
4751 | /* | |
41a2d6cf IM |
4752 | * The core wakeup function. Non-exclusive wakeups (nr_exclusive == 0) just |
4753 | * wake everything up. If it's an exclusive wakeup (nr_exclusive == small +ve | |
1da177e4 LT |
4754 | * number) then we wake all the non-exclusive tasks and one exclusive task. |
4755 | * | |
4756 | * There are circumstances in which we can try to wake a task which has already | |
41a2d6cf | 4757 | * started to run but is not in state TASK_RUNNING. try_to_wake_up() returns |
1da177e4 LT |
4758 | * zero in this (rare) case, and we handle it by continuing to scan the queue. |
4759 | */ | |
4760 | static void __wake_up_common(wait_queue_head_t *q, unsigned int mode, | |
4761 | int nr_exclusive, int sync, void *key) | |
4762 | { | |
2e45874c | 4763 | wait_queue_t *curr, *next; |
1da177e4 | 4764 | |
2e45874c | 4765 | list_for_each_entry_safe(curr, next, &q->task_list, task_list) { |
48f24c4d IM |
4766 | unsigned flags = curr->flags; |
4767 | ||
1da177e4 | 4768 | if (curr->func(curr, mode, sync, key) && |
48f24c4d | 4769 | (flags & WQ_FLAG_EXCLUSIVE) && !--nr_exclusive) |
1da177e4 LT |
4770 | break; |
4771 | } | |
4772 | } | |
4773 | ||
4774 | /** | |
4775 | * __wake_up - wake up threads blocked on a waitqueue. | |
4776 | * @q: the waitqueue | |
4777 | * @mode: which threads | |
4778 | * @nr_exclusive: how many wake-one or wake-many threads to wake up | |
67be2dd1 | 4779 | * @key: is directly passed to the wakeup function |
1da177e4 | 4780 | */ |
7ad5b3a5 | 4781 | void __wake_up(wait_queue_head_t *q, unsigned int mode, |
95cdf3b7 | 4782 | int nr_exclusive, void *key) |
1da177e4 LT |
4783 | { |
4784 | unsigned long flags; | |
4785 | ||
4786 | spin_lock_irqsave(&q->lock, flags); | |
4787 | __wake_up_common(q, mode, nr_exclusive, 0, key); | |
4788 | spin_unlock_irqrestore(&q->lock, flags); | |
4789 | } | |
1da177e4 LT |
4790 | EXPORT_SYMBOL(__wake_up); |
4791 | ||
4792 | /* | |
4793 | * Same as __wake_up but called with the spinlock in wait_queue_head_t held. | |
4794 | */ | |
7ad5b3a5 | 4795 | void __wake_up_locked(wait_queue_head_t *q, unsigned int mode) |
1da177e4 LT |
4796 | { |
4797 | __wake_up_common(q, mode, 1, 0, NULL); | |
4798 | } | |
4799 | ||
4800 | /** | |
67be2dd1 | 4801 | * __wake_up_sync - wake up threads blocked on a waitqueue. |
1da177e4 LT |
4802 | * @q: the waitqueue |
4803 | * @mode: which threads | |
4804 | * @nr_exclusive: how many wake-one or wake-many threads to wake up | |
4805 | * | |
4806 | * The sync wakeup differs that the waker knows that it will schedule | |
4807 | * away soon, so while the target thread will be woken up, it will not | |
4808 | * be migrated to another CPU - ie. the two threads are 'synchronized' | |
4809 | * with each other. This can prevent needless bouncing between CPUs. | |
4810 | * | |
4811 | * On UP it can prevent extra preemption. | |
4812 | */ | |
7ad5b3a5 | 4813 | void |
95cdf3b7 | 4814 | __wake_up_sync(wait_queue_head_t *q, unsigned int mode, int nr_exclusive) |
1da177e4 LT |
4815 | { |
4816 | unsigned long flags; | |
4817 | int sync = 1; | |
4818 | ||
4819 | if (unlikely(!q)) | |
4820 | return; | |
4821 | ||
4822 | if (unlikely(!nr_exclusive)) | |
4823 | sync = 0; | |
4824 | ||
4825 | spin_lock_irqsave(&q->lock, flags); | |
4826 | __wake_up_common(q, mode, nr_exclusive, sync, NULL); | |
4827 | spin_unlock_irqrestore(&q->lock, flags); | |
4828 | } | |
4829 | EXPORT_SYMBOL_GPL(__wake_up_sync); /* For internal use only */ | |
4830 | ||
65eb3dc6 KD |
4831 | /** |
4832 | * complete: - signals a single thread waiting on this completion | |
4833 | * @x: holds the state of this particular completion | |
4834 | * | |
4835 | * This will wake up a single thread waiting on this completion. Threads will be | |
4836 | * awakened in the same order in which they were queued. | |
4837 | * | |
4838 | * See also complete_all(), wait_for_completion() and related routines. | |
4839 | */ | |
b15136e9 | 4840 | void complete(struct completion *x) |
1da177e4 LT |
4841 | { |
4842 | unsigned long flags; | |
4843 | ||
4844 | spin_lock_irqsave(&x->wait.lock, flags); | |
4845 | x->done++; | |
d9514f6c | 4846 | __wake_up_common(&x->wait, TASK_NORMAL, 1, 0, NULL); |
1da177e4 LT |
4847 | spin_unlock_irqrestore(&x->wait.lock, flags); |
4848 | } | |
4849 | EXPORT_SYMBOL(complete); | |
4850 | ||
65eb3dc6 KD |
4851 | /** |
4852 | * complete_all: - signals all threads waiting on this completion | |
4853 | * @x: holds the state of this particular completion | |
4854 | * | |
4855 | * This will wake up all threads waiting on this particular completion event. | |
4856 | */ | |
b15136e9 | 4857 | void complete_all(struct completion *x) |
1da177e4 LT |
4858 | { |
4859 | unsigned long flags; | |
4860 | ||
4861 | spin_lock_irqsave(&x->wait.lock, flags); | |
4862 | x->done += UINT_MAX/2; | |
d9514f6c | 4863 | __wake_up_common(&x->wait, TASK_NORMAL, 0, 0, NULL); |
1da177e4 LT |
4864 | spin_unlock_irqrestore(&x->wait.lock, flags); |
4865 | } | |
4866 | EXPORT_SYMBOL(complete_all); | |
4867 | ||
8cbbe86d AK |
4868 | static inline long __sched |
4869 | do_wait_for_common(struct completion *x, long timeout, int state) | |
1da177e4 | 4870 | { |
1da177e4 LT |
4871 | if (!x->done) { |
4872 | DECLARE_WAITQUEUE(wait, current); | |
4873 | ||
4874 | wait.flags |= WQ_FLAG_EXCLUSIVE; | |
4875 | __add_wait_queue_tail(&x->wait, &wait); | |
4876 | do { | |
94d3d824 | 4877 | if (signal_pending_state(state, current)) { |
ea71a546 ON |
4878 | timeout = -ERESTARTSYS; |
4879 | break; | |
8cbbe86d AK |
4880 | } |
4881 | __set_current_state(state); | |
1da177e4 LT |
4882 | spin_unlock_irq(&x->wait.lock); |
4883 | timeout = schedule_timeout(timeout); | |
4884 | spin_lock_irq(&x->wait.lock); | |
ea71a546 | 4885 | } while (!x->done && timeout); |
1da177e4 | 4886 | __remove_wait_queue(&x->wait, &wait); |
ea71a546 ON |
4887 | if (!x->done) |
4888 | return timeout; | |
1da177e4 LT |
4889 | } |
4890 | x->done--; | |
ea71a546 | 4891 | return timeout ?: 1; |
1da177e4 | 4892 | } |
1da177e4 | 4893 | |
8cbbe86d AK |
4894 | static long __sched |
4895 | wait_for_common(struct completion *x, long timeout, int state) | |
1da177e4 | 4896 | { |
1da177e4 LT |
4897 | might_sleep(); |
4898 | ||
4899 | spin_lock_irq(&x->wait.lock); | |
8cbbe86d | 4900 | timeout = do_wait_for_common(x, timeout, state); |
1da177e4 | 4901 | spin_unlock_irq(&x->wait.lock); |
8cbbe86d AK |
4902 | return timeout; |
4903 | } | |
1da177e4 | 4904 | |
65eb3dc6 KD |
4905 | /** |
4906 | * wait_for_completion: - waits for completion of a task | |
4907 | * @x: holds the state of this particular completion | |
4908 | * | |
4909 | * This waits to be signaled for completion of a specific task. It is NOT | |
4910 | * interruptible and there is no timeout. | |
4911 | * | |
4912 | * See also similar routines (i.e. wait_for_completion_timeout()) with timeout | |
4913 | * and interrupt capability. Also see complete(). | |
4914 | */ | |
b15136e9 | 4915 | void __sched wait_for_completion(struct completion *x) |
8cbbe86d AK |
4916 | { |
4917 | wait_for_common(x, MAX_SCHEDULE_TIMEOUT, TASK_UNINTERRUPTIBLE); | |
1da177e4 | 4918 | } |
8cbbe86d | 4919 | EXPORT_SYMBOL(wait_for_completion); |
1da177e4 | 4920 | |
65eb3dc6 KD |
4921 | /** |
4922 | * wait_for_completion_timeout: - waits for completion of a task (w/timeout) | |
4923 | * @x: holds the state of this particular completion | |
4924 | * @timeout: timeout value in jiffies | |
4925 | * | |
4926 | * This waits for either a completion of a specific task to be signaled or for a | |
4927 | * specified timeout to expire. The timeout is in jiffies. It is not | |
4928 | * interruptible. | |
4929 | */ | |
b15136e9 | 4930 | unsigned long __sched |
8cbbe86d | 4931 | wait_for_completion_timeout(struct completion *x, unsigned long timeout) |
1da177e4 | 4932 | { |
8cbbe86d | 4933 | return wait_for_common(x, timeout, TASK_UNINTERRUPTIBLE); |
1da177e4 | 4934 | } |
8cbbe86d | 4935 | EXPORT_SYMBOL(wait_for_completion_timeout); |
1da177e4 | 4936 | |
65eb3dc6 KD |
4937 | /** |
4938 | * wait_for_completion_interruptible: - waits for completion of a task (w/intr) | |
4939 | * @x: holds the state of this particular completion | |
4940 | * | |
4941 | * This waits for completion of a specific task to be signaled. It is | |
4942 | * interruptible. | |
4943 | */ | |
8cbbe86d | 4944 | int __sched wait_for_completion_interruptible(struct completion *x) |
0fec171c | 4945 | { |
51e97990 AK |
4946 | long t = wait_for_common(x, MAX_SCHEDULE_TIMEOUT, TASK_INTERRUPTIBLE); |
4947 | if (t == -ERESTARTSYS) | |
4948 | return t; | |
4949 | return 0; | |
0fec171c | 4950 | } |
8cbbe86d | 4951 | EXPORT_SYMBOL(wait_for_completion_interruptible); |
1da177e4 | 4952 | |
65eb3dc6 KD |
4953 | /** |
4954 | * wait_for_completion_interruptible_timeout: - waits for completion (w/(to,intr)) | |
4955 | * @x: holds the state of this particular completion | |
4956 | * @timeout: timeout value in jiffies | |
4957 | * | |
4958 | * This waits for either a completion of a specific task to be signaled or for a | |
4959 | * specified timeout to expire. It is interruptible. The timeout is in jiffies. | |
4960 | */ | |
b15136e9 | 4961 | unsigned long __sched |
8cbbe86d AK |
4962 | wait_for_completion_interruptible_timeout(struct completion *x, |
4963 | unsigned long timeout) | |
0fec171c | 4964 | { |
8cbbe86d | 4965 | return wait_for_common(x, timeout, TASK_INTERRUPTIBLE); |
0fec171c | 4966 | } |
8cbbe86d | 4967 | EXPORT_SYMBOL(wait_for_completion_interruptible_timeout); |
1da177e4 | 4968 | |
65eb3dc6 KD |
4969 | /** |
4970 | * wait_for_completion_killable: - waits for completion of a task (killable) | |
4971 | * @x: holds the state of this particular completion | |
4972 | * | |
4973 | * This waits to be signaled for completion of a specific task. It can be | |
4974 | * interrupted by a kill signal. | |
4975 | */ | |
009e577e MW |
4976 | int __sched wait_for_completion_killable(struct completion *x) |
4977 | { | |
4978 | long t = wait_for_common(x, MAX_SCHEDULE_TIMEOUT, TASK_KILLABLE); | |
4979 | if (t == -ERESTARTSYS) | |
4980 | return t; | |
4981 | return 0; | |
4982 | } | |
4983 | EXPORT_SYMBOL(wait_for_completion_killable); | |
4984 | ||
be4de352 DC |
4985 | /** |
4986 | * try_wait_for_completion - try to decrement a completion without blocking | |
4987 | * @x: completion structure | |
4988 | * | |
4989 | * Returns: 0 if a decrement cannot be done without blocking | |
4990 | * 1 if a decrement succeeded. | |
4991 | * | |
4992 | * If a completion is being used as a counting completion, | |
4993 | * attempt to decrement the counter without blocking. This | |
4994 | * enables us to avoid waiting if the resource the completion | |
4995 | * is protecting is not available. | |
4996 | */ | |
4997 | bool try_wait_for_completion(struct completion *x) | |
4998 | { | |
4999 | int ret = 1; | |
5000 | ||
5001 | spin_lock_irq(&x->wait.lock); | |
5002 | if (!x->done) | |
5003 | ret = 0; | |
5004 | else | |
5005 | x->done--; | |
5006 | spin_unlock_irq(&x->wait.lock); | |
5007 | return ret; | |
5008 | } | |
5009 | EXPORT_SYMBOL(try_wait_for_completion); | |
5010 | ||
5011 | /** | |
5012 | * completion_done - Test to see if a completion has any waiters | |
5013 | * @x: completion structure | |
5014 | * | |
5015 | * Returns: 0 if there are waiters (wait_for_completion() in progress) | |
5016 | * 1 if there are no waiters. | |
5017 | * | |
5018 | */ | |
5019 | bool completion_done(struct completion *x) | |
5020 | { | |
5021 | int ret = 1; | |
5022 | ||
5023 | spin_lock_irq(&x->wait.lock); | |
5024 | if (!x->done) | |
5025 | ret = 0; | |
5026 | spin_unlock_irq(&x->wait.lock); | |
5027 | return ret; | |
5028 | } | |
5029 | EXPORT_SYMBOL(completion_done); | |
5030 | ||
8cbbe86d AK |
5031 | static long __sched |
5032 | sleep_on_common(wait_queue_head_t *q, int state, long timeout) | |
1da177e4 | 5033 | { |
0fec171c IM |
5034 | unsigned long flags; |
5035 | wait_queue_t wait; | |
5036 | ||
5037 | init_waitqueue_entry(&wait, current); | |
1da177e4 | 5038 | |
8cbbe86d | 5039 | __set_current_state(state); |
1da177e4 | 5040 | |
8cbbe86d AK |
5041 | spin_lock_irqsave(&q->lock, flags); |
5042 | __add_wait_queue(q, &wait); | |
5043 | spin_unlock(&q->lock); | |
5044 | timeout = schedule_timeout(timeout); | |
5045 | spin_lock_irq(&q->lock); | |
5046 | __remove_wait_queue(q, &wait); | |
5047 | spin_unlock_irqrestore(&q->lock, flags); | |
5048 | ||
5049 | return timeout; | |
5050 | } | |
5051 | ||
5052 | void __sched interruptible_sleep_on(wait_queue_head_t *q) | |
5053 | { | |
5054 | sleep_on_common(q, TASK_INTERRUPTIBLE, MAX_SCHEDULE_TIMEOUT); | |
1da177e4 | 5055 | } |
1da177e4 LT |
5056 | EXPORT_SYMBOL(interruptible_sleep_on); |
5057 | ||
0fec171c | 5058 | long __sched |
95cdf3b7 | 5059 | interruptible_sleep_on_timeout(wait_queue_head_t *q, long timeout) |
1da177e4 | 5060 | { |
8cbbe86d | 5061 | return sleep_on_common(q, TASK_INTERRUPTIBLE, timeout); |
1da177e4 | 5062 | } |
1da177e4 LT |
5063 | EXPORT_SYMBOL(interruptible_sleep_on_timeout); |
5064 | ||
0fec171c | 5065 | void __sched sleep_on(wait_queue_head_t *q) |
1da177e4 | 5066 | { |
8cbbe86d | 5067 | sleep_on_common(q, TASK_UNINTERRUPTIBLE, MAX_SCHEDULE_TIMEOUT); |
1da177e4 | 5068 | } |
1da177e4 LT |
5069 | EXPORT_SYMBOL(sleep_on); |
5070 | ||
0fec171c | 5071 | long __sched sleep_on_timeout(wait_queue_head_t *q, long timeout) |
1da177e4 | 5072 | { |
8cbbe86d | 5073 | return sleep_on_common(q, TASK_UNINTERRUPTIBLE, timeout); |
1da177e4 | 5074 | } |
1da177e4 LT |
5075 | EXPORT_SYMBOL(sleep_on_timeout); |
5076 | ||
b29739f9 IM |
5077 | #ifdef CONFIG_RT_MUTEXES |
5078 | ||
5079 | /* | |
5080 | * rt_mutex_setprio - set the current priority of a task | |
5081 | * @p: task | |
5082 | * @prio: prio value (kernel-internal form) | |
5083 | * | |
5084 | * This function changes the 'effective' priority of a task. It does | |
5085 | * not touch ->normal_prio like __setscheduler(). | |
5086 | * | |
5087 | * Used by the rt_mutex code to implement priority inheritance logic. | |
5088 | */ | |
36c8b586 | 5089 | void rt_mutex_setprio(struct task_struct *p, int prio) |
b29739f9 IM |
5090 | { |
5091 | unsigned long flags; | |
83b699ed | 5092 | int oldprio, on_rq, running; |
70b97a7f | 5093 | struct rq *rq; |
cb469845 | 5094 | const struct sched_class *prev_class = p->sched_class; |
b29739f9 IM |
5095 | |
5096 | BUG_ON(prio < 0 || prio > MAX_PRIO); | |
5097 | ||
5098 | rq = task_rq_lock(p, &flags); | |
a8e504d2 | 5099 | update_rq_clock(rq); |
b29739f9 | 5100 | |
d5f9f942 | 5101 | oldprio = p->prio; |
dd41f596 | 5102 | on_rq = p->se.on_rq; |
051a1d1a | 5103 | running = task_current(rq, p); |
0e1f3483 | 5104 | if (on_rq) |
69be72c1 | 5105 | dequeue_task(rq, p, 0); |
0e1f3483 HS |
5106 | if (running) |
5107 | p->sched_class->put_prev_task(rq, p); | |
dd41f596 IM |
5108 | |
5109 | if (rt_prio(prio)) | |
5110 | p->sched_class = &rt_sched_class; | |
5111 | else | |
5112 | p->sched_class = &fair_sched_class; | |
5113 | ||
b29739f9 IM |
5114 | p->prio = prio; |
5115 | ||
0e1f3483 HS |
5116 | if (running) |
5117 | p->sched_class->set_curr_task(rq); | |
dd41f596 | 5118 | if (on_rq) { |
8159f87e | 5119 | enqueue_task(rq, p, 0); |
cb469845 SR |
5120 | |
5121 | check_class_changed(rq, p, prev_class, oldprio, running); | |
b29739f9 IM |
5122 | } |
5123 | task_rq_unlock(rq, &flags); | |
5124 | } | |
5125 | ||
5126 | #endif | |
5127 | ||
36c8b586 | 5128 | void set_user_nice(struct task_struct *p, long nice) |
1da177e4 | 5129 | { |
dd41f596 | 5130 | int old_prio, delta, on_rq; |
1da177e4 | 5131 | unsigned long flags; |
70b97a7f | 5132 | struct rq *rq; |
1da177e4 LT |
5133 | |
5134 | if (TASK_NICE(p) == nice || nice < -20 || nice > 19) | |
5135 | return; | |
5136 | /* | |
5137 | * We have to be careful, if called from sys_setpriority(), | |
5138 | * the task might be in the middle of scheduling on another CPU. | |
5139 | */ | |
5140 | rq = task_rq_lock(p, &flags); | |
a8e504d2 | 5141 | update_rq_clock(rq); |
1da177e4 LT |
5142 | /* |
5143 | * The RT priorities are set via sched_setscheduler(), but we still | |
5144 | * allow the 'normal' nice value to be set - but as expected | |
5145 | * it wont have any effect on scheduling until the task is | |
dd41f596 | 5146 | * SCHED_FIFO/SCHED_RR: |
1da177e4 | 5147 | */ |
e05606d3 | 5148 | if (task_has_rt_policy(p)) { |
1da177e4 LT |
5149 | p->static_prio = NICE_TO_PRIO(nice); |
5150 | goto out_unlock; | |
5151 | } | |
dd41f596 | 5152 | on_rq = p->se.on_rq; |
c09595f6 | 5153 | if (on_rq) |
69be72c1 | 5154 | dequeue_task(rq, p, 0); |
1da177e4 | 5155 | |
1da177e4 | 5156 | p->static_prio = NICE_TO_PRIO(nice); |
2dd73a4f | 5157 | set_load_weight(p); |
b29739f9 IM |
5158 | old_prio = p->prio; |
5159 | p->prio = effective_prio(p); | |
5160 | delta = p->prio - old_prio; | |
1da177e4 | 5161 | |
dd41f596 | 5162 | if (on_rq) { |
8159f87e | 5163 | enqueue_task(rq, p, 0); |
1da177e4 | 5164 | /* |
d5f9f942 AM |
5165 | * If the task increased its priority or is running and |
5166 | * lowered its priority, then reschedule its CPU: | |
1da177e4 | 5167 | */ |
d5f9f942 | 5168 | if (delta < 0 || (delta > 0 && task_running(rq, p))) |
1da177e4 LT |
5169 | resched_task(rq->curr); |
5170 | } | |
5171 | out_unlock: | |
5172 | task_rq_unlock(rq, &flags); | |
5173 | } | |
1da177e4 LT |
5174 | EXPORT_SYMBOL(set_user_nice); |
5175 | ||
e43379f1 MM |
5176 | /* |
5177 | * can_nice - check if a task can reduce its nice value | |
5178 | * @p: task | |
5179 | * @nice: nice value | |
5180 | */ | |
36c8b586 | 5181 | int can_nice(const struct task_struct *p, const int nice) |
e43379f1 | 5182 | { |
024f4747 MM |
5183 | /* convert nice value [19,-20] to rlimit style value [1,40] */ |
5184 | int nice_rlim = 20 - nice; | |
48f24c4d | 5185 | |
e43379f1 MM |
5186 | return (nice_rlim <= p->signal->rlim[RLIMIT_NICE].rlim_cur || |
5187 | capable(CAP_SYS_NICE)); | |
5188 | } | |
5189 | ||
1da177e4 LT |
5190 | #ifdef __ARCH_WANT_SYS_NICE |
5191 | ||
5192 | /* | |
5193 | * sys_nice - change the priority of the current process. | |
5194 | * @increment: priority increment | |
5195 | * | |
5196 | * sys_setpriority is a more generic, but much slower function that | |
5197 | * does similar things. | |
5198 | */ | |
5add95d4 | 5199 | SYSCALL_DEFINE1(nice, int, increment) |
1da177e4 | 5200 | { |
48f24c4d | 5201 | long nice, retval; |
1da177e4 LT |
5202 | |
5203 | /* | |
5204 | * Setpriority might change our priority at the same moment. | |
5205 | * We don't have to worry. Conceptually one call occurs first | |
5206 | * and we have a single winner. | |
5207 | */ | |
e43379f1 MM |
5208 | if (increment < -40) |
5209 | increment = -40; | |
1da177e4 LT |
5210 | if (increment > 40) |
5211 | increment = 40; | |
5212 | ||
5213 | nice = PRIO_TO_NICE(current->static_prio) + increment; | |
5214 | if (nice < -20) | |
5215 | nice = -20; | |
5216 | if (nice > 19) | |
5217 | nice = 19; | |
5218 | ||
e43379f1 MM |
5219 | if (increment < 0 && !can_nice(current, nice)) |
5220 | return -EPERM; | |
5221 | ||
1da177e4 LT |
5222 | retval = security_task_setnice(current, nice); |
5223 | if (retval) | |
5224 | return retval; | |
5225 | ||
5226 | set_user_nice(current, nice); | |
5227 | return 0; | |
5228 | } | |
5229 | ||
5230 | #endif | |
5231 | ||
5232 | /** | |
5233 | * task_prio - return the priority value of a given task. | |
5234 | * @p: the task in question. | |
5235 | * | |
5236 | * This is the priority value as seen by users in /proc. | |
5237 | * RT tasks are offset by -200. Normal tasks are centered | |
5238 | * around 0, value goes from -16 to +15. | |
5239 | */ | |
36c8b586 | 5240 | int task_prio(const struct task_struct *p) |
1da177e4 LT |
5241 | { |
5242 | return p->prio - MAX_RT_PRIO; | |
5243 | } | |
5244 | ||
5245 | /** | |
5246 | * task_nice - return the nice value of a given task. | |
5247 | * @p: the task in question. | |
5248 | */ | |
36c8b586 | 5249 | int task_nice(const struct task_struct *p) |
1da177e4 LT |
5250 | { |
5251 | return TASK_NICE(p); | |
5252 | } | |
150d8bed | 5253 | EXPORT_SYMBOL(task_nice); |
1da177e4 LT |
5254 | |
5255 | /** | |
5256 | * idle_cpu - is a given cpu idle currently? | |
5257 | * @cpu: the processor in question. | |
5258 | */ | |
5259 | int idle_cpu(int cpu) | |
5260 | { | |
5261 | return cpu_curr(cpu) == cpu_rq(cpu)->idle; | |
5262 | } | |
5263 | ||
1da177e4 LT |
5264 | /** |
5265 | * idle_task - return the idle task for a given cpu. | |
5266 | * @cpu: the processor in question. | |
5267 | */ | |
36c8b586 | 5268 | struct task_struct *idle_task(int cpu) |
1da177e4 LT |
5269 | { |
5270 | return cpu_rq(cpu)->idle; | |
5271 | } | |
5272 | ||
5273 | /** | |
5274 | * find_process_by_pid - find a process with a matching PID value. | |
5275 | * @pid: the pid in question. | |
5276 | */ | |
a9957449 | 5277 | static struct task_struct *find_process_by_pid(pid_t pid) |
1da177e4 | 5278 | { |
228ebcbe | 5279 | return pid ? find_task_by_vpid(pid) : current; |
1da177e4 LT |
5280 | } |
5281 | ||
5282 | /* Actually do priority change: must hold rq lock. */ | |
dd41f596 IM |
5283 | static void |
5284 | __setscheduler(struct rq *rq, struct task_struct *p, int policy, int prio) | |
1da177e4 | 5285 | { |
dd41f596 | 5286 | BUG_ON(p->se.on_rq); |
48f24c4d | 5287 | |
1da177e4 | 5288 | p->policy = policy; |
dd41f596 IM |
5289 | switch (p->policy) { |
5290 | case SCHED_NORMAL: | |
5291 | case SCHED_BATCH: | |
5292 | case SCHED_IDLE: | |
5293 | p->sched_class = &fair_sched_class; | |
5294 | break; | |
5295 | case SCHED_FIFO: | |
5296 | case SCHED_RR: | |
5297 | p->sched_class = &rt_sched_class; | |
5298 | break; | |
5299 | } | |
5300 | ||
1da177e4 | 5301 | p->rt_priority = prio; |
b29739f9 IM |
5302 | p->normal_prio = normal_prio(p); |
5303 | /* we are holding p->pi_lock already */ | |
5304 | p->prio = rt_mutex_getprio(p); | |
2dd73a4f | 5305 | set_load_weight(p); |
1da177e4 LT |
5306 | } |
5307 | ||
c69e8d9c DH |
5308 | /* |
5309 | * check the target process has a UID that matches the current process's | |
5310 | */ | |
5311 | static bool check_same_owner(struct task_struct *p) | |
5312 | { | |
5313 | const struct cred *cred = current_cred(), *pcred; | |
5314 | bool match; | |
5315 | ||
5316 | rcu_read_lock(); | |
5317 | pcred = __task_cred(p); | |
5318 | match = (cred->euid == pcred->euid || | |
5319 | cred->euid == pcred->uid); | |
5320 | rcu_read_unlock(); | |
5321 | return match; | |
5322 | } | |
5323 | ||
961ccddd RR |
5324 | static int __sched_setscheduler(struct task_struct *p, int policy, |
5325 | struct sched_param *param, bool user) | |
1da177e4 | 5326 | { |
83b699ed | 5327 | int retval, oldprio, oldpolicy = -1, on_rq, running; |
1da177e4 | 5328 | unsigned long flags; |
cb469845 | 5329 | const struct sched_class *prev_class = p->sched_class; |
70b97a7f | 5330 | struct rq *rq; |
1da177e4 | 5331 | |
66e5393a SR |
5332 | /* may grab non-irq protected spin_locks */ |
5333 | BUG_ON(in_interrupt()); | |
1da177e4 LT |
5334 | recheck: |
5335 | /* double check policy once rq lock held */ | |
5336 | if (policy < 0) | |
5337 | policy = oldpolicy = p->policy; | |
5338 | else if (policy != SCHED_FIFO && policy != SCHED_RR && | |
dd41f596 IM |
5339 | policy != SCHED_NORMAL && policy != SCHED_BATCH && |
5340 | policy != SCHED_IDLE) | |
b0a9499c | 5341 | return -EINVAL; |
1da177e4 LT |
5342 | /* |
5343 | * Valid priorities for SCHED_FIFO and SCHED_RR are | |
dd41f596 IM |
5344 | * 1..MAX_USER_RT_PRIO-1, valid priority for SCHED_NORMAL, |
5345 | * SCHED_BATCH and SCHED_IDLE is 0. | |
1da177e4 LT |
5346 | */ |
5347 | if (param->sched_priority < 0 || | |
95cdf3b7 | 5348 | (p->mm && param->sched_priority > MAX_USER_RT_PRIO-1) || |
d46523ea | 5349 | (!p->mm && param->sched_priority > MAX_RT_PRIO-1)) |
1da177e4 | 5350 | return -EINVAL; |
e05606d3 | 5351 | if (rt_policy(policy) != (param->sched_priority != 0)) |
1da177e4 LT |
5352 | return -EINVAL; |
5353 | ||
37e4ab3f OC |
5354 | /* |
5355 | * Allow unprivileged RT tasks to decrease priority: | |
5356 | */ | |
961ccddd | 5357 | if (user && !capable(CAP_SYS_NICE)) { |
e05606d3 | 5358 | if (rt_policy(policy)) { |
8dc3e909 | 5359 | unsigned long rlim_rtprio; |
8dc3e909 ON |
5360 | |
5361 | if (!lock_task_sighand(p, &flags)) | |
5362 | return -ESRCH; | |
5363 | rlim_rtprio = p->signal->rlim[RLIMIT_RTPRIO].rlim_cur; | |
5364 | unlock_task_sighand(p, &flags); | |
5365 | ||
5366 | /* can't set/change the rt policy */ | |
5367 | if (policy != p->policy && !rlim_rtprio) | |
5368 | return -EPERM; | |
5369 | ||
5370 | /* can't increase priority */ | |
5371 | if (param->sched_priority > p->rt_priority && | |
5372 | param->sched_priority > rlim_rtprio) | |
5373 | return -EPERM; | |
5374 | } | |
dd41f596 IM |
5375 | /* |
5376 | * Like positive nice levels, dont allow tasks to | |
5377 | * move out of SCHED_IDLE either: | |
5378 | */ | |
5379 | if (p->policy == SCHED_IDLE && policy != SCHED_IDLE) | |
5380 | return -EPERM; | |
5fe1d75f | 5381 | |
37e4ab3f | 5382 | /* can't change other user's priorities */ |
c69e8d9c | 5383 | if (!check_same_owner(p)) |
37e4ab3f OC |
5384 | return -EPERM; |
5385 | } | |
1da177e4 | 5386 | |
725aad24 | 5387 | if (user) { |
b68aa230 | 5388 | #ifdef CONFIG_RT_GROUP_SCHED |
725aad24 JF |
5389 | /* |
5390 | * Do not allow realtime tasks into groups that have no runtime | |
5391 | * assigned. | |
5392 | */ | |
9a7e0b18 PZ |
5393 | if (rt_bandwidth_enabled() && rt_policy(policy) && |
5394 | task_group(p)->rt_bandwidth.rt_runtime == 0) | |
725aad24 | 5395 | return -EPERM; |
b68aa230 PZ |
5396 | #endif |
5397 | ||
725aad24 JF |
5398 | retval = security_task_setscheduler(p, policy, param); |
5399 | if (retval) | |
5400 | return retval; | |
5401 | } | |
5402 | ||
b29739f9 IM |
5403 | /* |
5404 | * make sure no PI-waiters arrive (or leave) while we are | |
5405 | * changing the priority of the task: | |
5406 | */ | |
5407 | spin_lock_irqsave(&p->pi_lock, flags); | |
1da177e4 LT |
5408 | /* |
5409 | * To be able to change p->policy safely, the apropriate | |
5410 | * runqueue lock must be held. | |
5411 | */ | |
b29739f9 | 5412 | rq = __task_rq_lock(p); |
1da177e4 LT |
5413 | /* recheck policy now with rq lock held */ |
5414 | if (unlikely(oldpolicy != -1 && oldpolicy != p->policy)) { | |
5415 | policy = oldpolicy = -1; | |
b29739f9 IM |
5416 | __task_rq_unlock(rq); |
5417 | spin_unlock_irqrestore(&p->pi_lock, flags); | |
1da177e4 LT |
5418 | goto recheck; |
5419 | } | |
2daa3577 | 5420 | update_rq_clock(rq); |
dd41f596 | 5421 | on_rq = p->se.on_rq; |
051a1d1a | 5422 | running = task_current(rq, p); |
0e1f3483 | 5423 | if (on_rq) |
2e1cb74a | 5424 | deactivate_task(rq, p, 0); |
0e1f3483 HS |
5425 | if (running) |
5426 | p->sched_class->put_prev_task(rq, p); | |
f6b53205 | 5427 | |
1da177e4 | 5428 | oldprio = p->prio; |
dd41f596 | 5429 | __setscheduler(rq, p, policy, param->sched_priority); |
f6b53205 | 5430 | |
0e1f3483 HS |
5431 | if (running) |
5432 | p->sched_class->set_curr_task(rq); | |
dd41f596 IM |
5433 | if (on_rq) { |
5434 | activate_task(rq, p, 0); | |
cb469845 SR |
5435 | |
5436 | check_class_changed(rq, p, prev_class, oldprio, running); | |
1da177e4 | 5437 | } |
b29739f9 IM |
5438 | __task_rq_unlock(rq); |
5439 | spin_unlock_irqrestore(&p->pi_lock, flags); | |
5440 | ||
95e02ca9 TG |
5441 | rt_mutex_adjust_pi(p); |
5442 | ||
1da177e4 LT |
5443 | return 0; |
5444 | } | |
961ccddd RR |
5445 | |
5446 | /** | |
5447 | * sched_setscheduler - change the scheduling policy and/or RT priority of a thread. | |
5448 | * @p: the task in question. | |
5449 | * @policy: new policy. | |
5450 | * @param: structure containing the new RT priority. | |
5451 | * | |
5452 | * NOTE that the task may be already dead. | |
5453 | */ | |
5454 | int sched_setscheduler(struct task_struct *p, int policy, | |
5455 | struct sched_param *param) | |
5456 | { | |
5457 | return __sched_setscheduler(p, policy, param, true); | |
5458 | } | |
1da177e4 LT |
5459 | EXPORT_SYMBOL_GPL(sched_setscheduler); |
5460 | ||
961ccddd RR |
5461 | /** |
5462 | * sched_setscheduler_nocheck - change the scheduling policy and/or RT priority of a thread from kernelspace. | |
5463 | * @p: the task in question. | |
5464 | * @policy: new policy. | |
5465 | * @param: structure containing the new RT priority. | |
5466 | * | |
5467 | * Just like sched_setscheduler, only don't bother checking if the | |
5468 | * current context has permission. For example, this is needed in | |
5469 | * stop_machine(): we create temporary high priority worker threads, | |
5470 | * but our caller might not have that capability. | |
5471 | */ | |
5472 | int sched_setscheduler_nocheck(struct task_struct *p, int policy, | |
5473 | struct sched_param *param) | |
5474 | { | |
5475 | return __sched_setscheduler(p, policy, param, false); | |
5476 | } | |
5477 | ||
95cdf3b7 IM |
5478 | static int |
5479 | do_sched_setscheduler(pid_t pid, int policy, struct sched_param __user *param) | |
1da177e4 | 5480 | { |
1da177e4 LT |
5481 | struct sched_param lparam; |
5482 | struct task_struct *p; | |
36c8b586 | 5483 | int retval; |
1da177e4 LT |
5484 | |
5485 | if (!param || pid < 0) | |
5486 | return -EINVAL; | |
5487 | if (copy_from_user(&lparam, param, sizeof(struct sched_param))) | |
5488 | return -EFAULT; | |
5fe1d75f ON |
5489 | |
5490 | rcu_read_lock(); | |
5491 | retval = -ESRCH; | |
1da177e4 | 5492 | p = find_process_by_pid(pid); |
5fe1d75f ON |
5493 | if (p != NULL) |
5494 | retval = sched_setscheduler(p, policy, &lparam); | |
5495 | rcu_read_unlock(); | |
36c8b586 | 5496 | |
1da177e4 LT |
5497 | return retval; |
5498 | } | |
5499 | ||
5500 | /** | |
5501 | * sys_sched_setscheduler - set/change the scheduler policy and RT priority | |
5502 | * @pid: the pid in question. | |
5503 | * @policy: new policy. | |
5504 | * @param: structure containing the new RT priority. | |
5505 | */ | |
5add95d4 HC |
5506 | SYSCALL_DEFINE3(sched_setscheduler, pid_t, pid, int, policy, |
5507 | struct sched_param __user *, param) | |
1da177e4 | 5508 | { |
c21761f1 JB |
5509 | /* negative values for policy are not valid */ |
5510 | if (policy < 0) | |
5511 | return -EINVAL; | |
5512 | ||
1da177e4 LT |
5513 | return do_sched_setscheduler(pid, policy, param); |
5514 | } | |
5515 | ||
5516 | /** | |
5517 | * sys_sched_setparam - set/change the RT priority of a thread | |
5518 | * @pid: the pid in question. | |
5519 | * @param: structure containing the new RT priority. | |
5520 | */ | |
5add95d4 | 5521 | SYSCALL_DEFINE2(sched_setparam, pid_t, pid, struct sched_param __user *, param) |
1da177e4 LT |
5522 | { |
5523 | return do_sched_setscheduler(pid, -1, param); | |
5524 | } | |
5525 | ||
5526 | /** | |
5527 | * sys_sched_getscheduler - get the policy (scheduling class) of a thread | |
5528 | * @pid: the pid in question. | |
5529 | */ | |
5add95d4 | 5530 | SYSCALL_DEFINE1(sched_getscheduler, pid_t, pid) |
1da177e4 | 5531 | { |
36c8b586 | 5532 | struct task_struct *p; |
3a5c359a | 5533 | int retval; |
1da177e4 LT |
5534 | |
5535 | if (pid < 0) | |
3a5c359a | 5536 | return -EINVAL; |
1da177e4 LT |
5537 | |
5538 | retval = -ESRCH; | |
5539 | read_lock(&tasklist_lock); | |
5540 | p = find_process_by_pid(pid); | |
5541 | if (p) { | |
5542 | retval = security_task_getscheduler(p); | |
5543 | if (!retval) | |
5544 | retval = p->policy; | |
5545 | } | |
5546 | read_unlock(&tasklist_lock); | |
1da177e4 LT |
5547 | return retval; |
5548 | } | |
5549 | ||
5550 | /** | |
5551 | * sys_sched_getscheduler - get the RT priority of a thread | |
5552 | * @pid: the pid in question. | |
5553 | * @param: structure containing the RT priority. | |
5554 | */ | |
5add95d4 | 5555 | SYSCALL_DEFINE2(sched_getparam, pid_t, pid, struct sched_param __user *, param) |
1da177e4 LT |
5556 | { |
5557 | struct sched_param lp; | |
36c8b586 | 5558 | struct task_struct *p; |
3a5c359a | 5559 | int retval; |
1da177e4 LT |
5560 | |
5561 | if (!param || pid < 0) | |
3a5c359a | 5562 | return -EINVAL; |
1da177e4 LT |
5563 | |
5564 | read_lock(&tasklist_lock); | |
5565 | p = find_process_by_pid(pid); | |
5566 | retval = -ESRCH; | |
5567 | if (!p) | |
5568 | goto out_unlock; | |
5569 | ||
5570 | retval = security_task_getscheduler(p); | |
5571 | if (retval) | |
5572 | goto out_unlock; | |
5573 | ||
5574 | lp.sched_priority = p->rt_priority; | |
5575 | read_unlock(&tasklist_lock); | |
5576 | ||
5577 | /* | |
5578 | * This one might sleep, we cannot do it with a spinlock held ... | |
5579 | */ | |
5580 | retval = copy_to_user(param, &lp, sizeof(*param)) ? -EFAULT : 0; | |
5581 | ||
1da177e4 LT |
5582 | return retval; |
5583 | ||
5584 | out_unlock: | |
5585 | read_unlock(&tasklist_lock); | |
5586 | return retval; | |
5587 | } | |
5588 | ||
96f874e2 | 5589 | long sched_setaffinity(pid_t pid, const struct cpumask *in_mask) |
1da177e4 | 5590 | { |
5a16f3d3 | 5591 | cpumask_var_t cpus_allowed, new_mask; |
36c8b586 IM |
5592 | struct task_struct *p; |
5593 | int retval; | |
1da177e4 | 5594 | |
95402b38 | 5595 | get_online_cpus(); |
1da177e4 LT |
5596 | read_lock(&tasklist_lock); |
5597 | ||
5598 | p = find_process_by_pid(pid); | |
5599 | if (!p) { | |
5600 | read_unlock(&tasklist_lock); | |
95402b38 | 5601 | put_online_cpus(); |
1da177e4 LT |
5602 | return -ESRCH; |
5603 | } | |
5604 | ||
5605 | /* | |
5606 | * It is not safe to call set_cpus_allowed with the | |
41a2d6cf | 5607 | * tasklist_lock held. We will bump the task_struct's |
1da177e4 LT |
5608 | * usage count and then drop tasklist_lock. |
5609 | */ | |
5610 | get_task_struct(p); | |
5611 | read_unlock(&tasklist_lock); | |
5612 | ||
5a16f3d3 RR |
5613 | if (!alloc_cpumask_var(&cpus_allowed, GFP_KERNEL)) { |
5614 | retval = -ENOMEM; | |
5615 | goto out_put_task; | |
5616 | } | |
5617 | if (!alloc_cpumask_var(&new_mask, GFP_KERNEL)) { | |
5618 | retval = -ENOMEM; | |
5619 | goto out_free_cpus_allowed; | |
5620 | } | |
1da177e4 | 5621 | retval = -EPERM; |
c69e8d9c | 5622 | if (!check_same_owner(p) && !capable(CAP_SYS_NICE)) |
1da177e4 LT |
5623 | goto out_unlock; |
5624 | ||
e7834f8f DQ |
5625 | retval = security_task_setscheduler(p, 0, NULL); |
5626 | if (retval) | |
5627 | goto out_unlock; | |
5628 | ||
5a16f3d3 RR |
5629 | cpuset_cpus_allowed(p, cpus_allowed); |
5630 | cpumask_and(new_mask, in_mask, cpus_allowed); | |
8707d8b8 | 5631 | again: |
5a16f3d3 | 5632 | retval = set_cpus_allowed_ptr(p, new_mask); |
1da177e4 | 5633 | |
8707d8b8 | 5634 | if (!retval) { |
5a16f3d3 RR |
5635 | cpuset_cpus_allowed(p, cpus_allowed); |
5636 | if (!cpumask_subset(new_mask, cpus_allowed)) { | |
8707d8b8 PM |
5637 | /* |
5638 | * We must have raced with a concurrent cpuset | |
5639 | * update. Just reset the cpus_allowed to the | |
5640 | * cpuset's cpus_allowed | |
5641 | */ | |
5a16f3d3 | 5642 | cpumask_copy(new_mask, cpus_allowed); |
8707d8b8 PM |
5643 | goto again; |
5644 | } | |
5645 | } | |
1da177e4 | 5646 | out_unlock: |
5a16f3d3 RR |
5647 | free_cpumask_var(new_mask); |
5648 | out_free_cpus_allowed: | |
5649 | free_cpumask_var(cpus_allowed); | |
5650 | out_put_task: | |
1da177e4 | 5651 | put_task_struct(p); |
95402b38 | 5652 | put_online_cpus(); |
1da177e4 LT |
5653 | return retval; |
5654 | } | |
5655 | ||
5656 | static int get_user_cpu_mask(unsigned long __user *user_mask_ptr, unsigned len, | |
96f874e2 | 5657 | struct cpumask *new_mask) |
1da177e4 | 5658 | { |
96f874e2 RR |
5659 | if (len < cpumask_size()) |
5660 | cpumask_clear(new_mask); | |
5661 | else if (len > cpumask_size()) | |
5662 | len = cpumask_size(); | |
5663 | ||
1da177e4 LT |
5664 | return copy_from_user(new_mask, user_mask_ptr, len) ? -EFAULT : 0; |
5665 | } | |
5666 | ||
5667 | /** | |
5668 | * sys_sched_setaffinity - set the cpu affinity of a process | |
5669 | * @pid: pid of the process | |
5670 | * @len: length in bytes of the bitmask pointed to by user_mask_ptr | |
5671 | * @user_mask_ptr: user-space pointer to the new cpu mask | |
5672 | */ | |
5add95d4 HC |
5673 | SYSCALL_DEFINE3(sched_setaffinity, pid_t, pid, unsigned int, len, |
5674 | unsigned long __user *, user_mask_ptr) | |
1da177e4 | 5675 | { |
5a16f3d3 | 5676 | cpumask_var_t new_mask; |
1da177e4 LT |
5677 | int retval; |
5678 | ||
5a16f3d3 RR |
5679 | if (!alloc_cpumask_var(&new_mask, GFP_KERNEL)) |
5680 | return -ENOMEM; | |
1da177e4 | 5681 | |
5a16f3d3 RR |
5682 | retval = get_user_cpu_mask(user_mask_ptr, len, new_mask); |
5683 | if (retval == 0) | |
5684 | retval = sched_setaffinity(pid, new_mask); | |
5685 | free_cpumask_var(new_mask); | |
5686 | return retval; | |
1da177e4 LT |
5687 | } |
5688 | ||
96f874e2 | 5689 | long sched_getaffinity(pid_t pid, struct cpumask *mask) |
1da177e4 | 5690 | { |
36c8b586 | 5691 | struct task_struct *p; |
1da177e4 | 5692 | int retval; |
1da177e4 | 5693 | |
95402b38 | 5694 | get_online_cpus(); |
1da177e4 LT |
5695 | read_lock(&tasklist_lock); |
5696 | ||
5697 | retval = -ESRCH; | |
5698 | p = find_process_by_pid(pid); | |
5699 | if (!p) | |
5700 | goto out_unlock; | |
5701 | ||
e7834f8f DQ |
5702 | retval = security_task_getscheduler(p); |
5703 | if (retval) | |
5704 | goto out_unlock; | |
5705 | ||
96f874e2 | 5706 | cpumask_and(mask, &p->cpus_allowed, cpu_online_mask); |
1da177e4 LT |
5707 | |
5708 | out_unlock: | |
5709 | read_unlock(&tasklist_lock); | |
95402b38 | 5710 | put_online_cpus(); |
1da177e4 | 5711 | |
9531b62f | 5712 | return retval; |
1da177e4 LT |
5713 | } |
5714 | ||
5715 | /** | |
5716 | * sys_sched_getaffinity - get the cpu affinity of a process | |
5717 | * @pid: pid of the process | |
5718 | * @len: length in bytes of the bitmask pointed to by user_mask_ptr | |
5719 | * @user_mask_ptr: user-space pointer to hold the current cpu mask | |
5720 | */ | |
5add95d4 HC |
5721 | SYSCALL_DEFINE3(sched_getaffinity, pid_t, pid, unsigned int, len, |
5722 | unsigned long __user *, user_mask_ptr) | |
1da177e4 LT |
5723 | { |
5724 | int ret; | |
f17c8607 | 5725 | cpumask_var_t mask; |
1da177e4 | 5726 | |
f17c8607 | 5727 | if (len < cpumask_size()) |
1da177e4 LT |
5728 | return -EINVAL; |
5729 | ||
f17c8607 RR |
5730 | if (!alloc_cpumask_var(&mask, GFP_KERNEL)) |
5731 | return -ENOMEM; | |
1da177e4 | 5732 | |
f17c8607 RR |
5733 | ret = sched_getaffinity(pid, mask); |
5734 | if (ret == 0) { | |
5735 | if (copy_to_user(user_mask_ptr, mask, cpumask_size())) | |
5736 | ret = -EFAULT; | |
5737 | else | |
5738 | ret = cpumask_size(); | |
5739 | } | |
5740 | free_cpumask_var(mask); | |
1da177e4 | 5741 | |
f17c8607 | 5742 | return ret; |
1da177e4 LT |
5743 | } |
5744 | ||
5745 | /** | |
5746 | * sys_sched_yield - yield the current processor to other threads. | |
5747 | * | |
dd41f596 IM |
5748 | * This function yields the current CPU to other tasks. If there are no |
5749 | * other threads running on this CPU then this function will return. | |
1da177e4 | 5750 | */ |
5add95d4 | 5751 | SYSCALL_DEFINE0(sched_yield) |
1da177e4 | 5752 | { |
70b97a7f | 5753 | struct rq *rq = this_rq_lock(); |
1da177e4 | 5754 | |
2d72376b | 5755 | schedstat_inc(rq, yld_count); |
4530d7ab | 5756 | current->sched_class->yield_task(rq); |
1da177e4 LT |
5757 | |
5758 | /* | |
5759 | * Since we are going to call schedule() anyway, there's | |
5760 | * no need to preempt or enable interrupts: | |
5761 | */ | |
5762 | __release(rq->lock); | |
8a25d5de | 5763 | spin_release(&rq->lock.dep_map, 1, _THIS_IP_); |
1da177e4 LT |
5764 | _raw_spin_unlock(&rq->lock); |
5765 | preempt_enable_no_resched(); | |
5766 | ||
5767 | schedule(); | |
5768 | ||
5769 | return 0; | |
5770 | } | |
5771 | ||
e7b38404 | 5772 | static void __cond_resched(void) |
1da177e4 | 5773 | { |
8e0a43d8 IM |
5774 | #ifdef CONFIG_DEBUG_SPINLOCK_SLEEP |
5775 | __might_sleep(__FILE__, __LINE__); | |
5776 | #endif | |
5bbcfd90 IM |
5777 | /* |
5778 | * The BKS might be reacquired before we have dropped | |
5779 | * PREEMPT_ACTIVE, which could trigger a second | |
5780 | * cond_resched() call. | |
5781 | */ | |
1da177e4 LT |
5782 | do { |
5783 | add_preempt_count(PREEMPT_ACTIVE); | |
5784 | schedule(); | |
5785 | sub_preempt_count(PREEMPT_ACTIVE); | |
5786 | } while (need_resched()); | |
5787 | } | |
5788 | ||
02b67cc3 | 5789 | int __sched _cond_resched(void) |
1da177e4 | 5790 | { |
9414232f IM |
5791 | if (need_resched() && !(preempt_count() & PREEMPT_ACTIVE) && |
5792 | system_state == SYSTEM_RUNNING) { | |
1da177e4 LT |
5793 | __cond_resched(); |
5794 | return 1; | |
5795 | } | |
5796 | return 0; | |
5797 | } | |
02b67cc3 | 5798 | EXPORT_SYMBOL(_cond_resched); |
1da177e4 LT |
5799 | |
5800 | /* | |
5801 | * cond_resched_lock() - if a reschedule is pending, drop the given lock, | |
5802 | * call schedule, and on return reacquire the lock. | |
5803 | * | |
41a2d6cf | 5804 | * This works OK both with and without CONFIG_PREEMPT. We do strange low-level |
1da177e4 LT |
5805 | * operations here to prevent schedule() from being called twice (once via |
5806 | * spin_unlock(), once by hand). | |
5807 | */ | |
95cdf3b7 | 5808 | int cond_resched_lock(spinlock_t *lock) |
1da177e4 | 5809 | { |
95c354fe | 5810 | int resched = need_resched() && system_state == SYSTEM_RUNNING; |
6df3cecb JK |
5811 | int ret = 0; |
5812 | ||
95c354fe | 5813 | if (spin_needbreak(lock) || resched) { |
1da177e4 | 5814 | spin_unlock(lock); |
95c354fe NP |
5815 | if (resched && need_resched()) |
5816 | __cond_resched(); | |
5817 | else | |
5818 | cpu_relax(); | |
6df3cecb | 5819 | ret = 1; |
1da177e4 | 5820 | spin_lock(lock); |
1da177e4 | 5821 | } |
6df3cecb | 5822 | return ret; |
1da177e4 | 5823 | } |
1da177e4 LT |
5824 | EXPORT_SYMBOL(cond_resched_lock); |
5825 | ||
5826 | int __sched cond_resched_softirq(void) | |
5827 | { | |
5828 | BUG_ON(!in_softirq()); | |
5829 | ||
9414232f | 5830 | if (need_resched() && system_state == SYSTEM_RUNNING) { |
98d82567 | 5831 | local_bh_enable(); |
1da177e4 LT |
5832 | __cond_resched(); |
5833 | local_bh_disable(); | |
5834 | return 1; | |
5835 | } | |
5836 | return 0; | |
5837 | } | |
1da177e4 LT |
5838 | EXPORT_SYMBOL(cond_resched_softirq); |
5839 | ||
1da177e4 LT |
5840 | /** |
5841 | * yield - yield the current processor to other threads. | |
5842 | * | |
72fd4a35 | 5843 | * This is a shortcut for kernel-space yielding - it marks the |
1da177e4 LT |
5844 | * thread runnable and calls sys_sched_yield(). |
5845 | */ | |
5846 | void __sched yield(void) | |
5847 | { | |
5848 | set_current_state(TASK_RUNNING); | |
5849 | sys_sched_yield(); | |
5850 | } | |
1da177e4 LT |
5851 | EXPORT_SYMBOL(yield); |
5852 | ||
5853 | /* | |
41a2d6cf | 5854 | * This task is about to go to sleep on IO. Increment rq->nr_iowait so |
1da177e4 LT |
5855 | * that process accounting knows that this is a task in IO wait state. |
5856 | * | |
5857 | * But don't do that if it is a deliberate, throttling IO wait (this task | |
5858 | * has set its backing_dev_info: the queue against which it should throttle) | |
5859 | */ | |
5860 | void __sched io_schedule(void) | |
5861 | { | |
70b97a7f | 5862 | struct rq *rq = &__raw_get_cpu_var(runqueues); |
1da177e4 | 5863 | |
0ff92245 | 5864 | delayacct_blkio_start(); |
1da177e4 LT |
5865 | atomic_inc(&rq->nr_iowait); |
5866 | schedule(); | |
5867 | atomic_dec(&rq->nr_iowait); | |
0ff92245 | 5868 | delayacct_blkio_end(); |
1da177e4 | 5869 | } |
1da177e4 LT |
5870 | EXPORT_SYMBOL(io_schedule); |
5871 | ||
5872 | long __sched io_schedule_timeout(long timeout) | |
5873 | { | |
70b97a7f | 5874 | struct rq *rq = &__raw_get_cpu_var(runqueues); |
1da177e4 LT |
5875 | long ret; |
5876 | ||
0ff92245 | 5877 | delayacct_blkio_start(); |
1da177e4 LT |
5878 | atomic_inc(&rq->nr_iowait); |
5879 | ret = schedule_timeout(timeout); | |
5880 | atomic_dec(&rq->nr_iowait); | |
0ff92245 | 5881 | delayacct_blkio_end(); |
1da177e4 LT |
5882 | return ret; |
5883 | } | |
5884 | ||
5885 | /** | |
5886 | * sys_sched_get_priority_max - return maximum RT priority. | |
5887 | * @policy: scheduling class. | |
5888 | * | |
5889 | * this syscall returns the maximum rt_priority that can be used | |
5890 | * by a given scheduling class. | |
5891 | */ | |
5add95d4 | 5892 | SYSCALL_DEFINE1(sched_get_priority_max, int, policy) |
1da177e4 LT |
5893 | { |
5894 | int ret = -EINVAL; | |
5895 | ||
5896 | switch (policy) { | |
5897 | case SCHED_FIFO: | |
5898 | case SCHED_RR: | |
5899 | ret = MAX_USER_RT_PRIO-1; | |
5900 | break; | |
5901 | case SCHED_NORMAL: | |
b0a9499c | 5902 | case SCHED_BATCH: |
dd41f596 | 5903 | case SCHED_IDLE: |
1da177e4 LT |
5904 | ret = 0; |
5905 | break; | |
5906 | } | |
5907 | return ret; | |
5908 | } | |
5909 | ||
5910 | /** | |
5911 | * sys_sched_get_priority_min - return minimum RT priority. | |
5912 | * @policy: scheduling class. | |
5913 | * | |
5914 | * this syscall returns the minimum rt_priority that can be used | |
5915 | * by a given scheduling class. | |
5916 | */ | |
5add95d4 | 5917 | SYSCALL_DEFINE1(sched_get_priority_min, int, policy) |
1da177e4 LT |
5918 | { |
5919 | int ret = -EINVAL; | |
5920 | ||
5921 | switch (policy) { | |
5922 | case SCHED_FIFO: | |
5923 | case SCHED_RR: | |
5924 | ret = 1; | |
5925 | break; | |
5926 | case SCHED_NORMAL: | |
b0a9499c | 5927 | case SCHED_BATCH: |
dd41f596 | 5928 | case SCHED_IDLE: |
1da177e4 LT |
5929 | ret = 0; |
5930 | } | |
5931 | return ret; | |
5932 | } | |
5933 | ||
5934 | /** | |
5935 | * sys_sched_rr_get_interval - return the default timeslice of a process. | |
5936 | * @pid: pid of the process. | |
5937 | * @interval: userspace pointer to the timeslice value. | |
5938 | * | |
5939 | * this syscall writes the default timeslice value of a given process | |
5940 | * into the user-space timespec buffer. A value of '0' means infinity. | |
5941 | */ | |
17da2bd9 | 5942 | SYSCALL_DEFINE2(sched_rr_get_interval, pid_t, pid, |
754fe8d2 | 5943 | struct timespec __user *, interval) |
1da177e4 | 5944 | { |
36c8b586 | 5945 | struct task_struct *p; |
a4ec24b4 | 5946 | unsigned int time_slice; |
3a5c359a | 5947 | int retval; |
1da177e4 | 5948 | struct timespec t; |
1da177e4 LT |
5949 | |
5950 | if (pid < 0) | |
3a5c359a | 5951 | return -EINVAL; |
1da177e4 LT |
5952 | |
5953 | retval = -ESRCH; | |
5954 | read_lock(&tasklist_lock); | |
5955 | p = find_process_by_pid(pid); | |
5956 | if (!p) | |
5957 | goto out_unlock; | |
5958 | ||
5959 | retval = security_task_getscheduler(p); | |
5960 | if (retval) | |
5961 | goto out_unlock; | |
5962 | ||
77034937 IM |
5963 | /* |
5964 | * Time slice is 0 for SCHED_FIFO tasks and for SCHED_OTHER | |
5965 | * tasks that are on an otherwise idle runqueue: | |
5966 | */ | |
5967 | time_slice = 0; | |
5968 | if (p->policy == SCHED_RR) { | |
a4ec24b4 | 5969 | time_slice = DEF_TIMESLICE; |
1868f958 | 5970 | } else if (p->policy != SCHED_FIFO) { |
a4ec24b4 DA |
5971 | struct sched_entity *se = &p->se; |
5972 | unsigned long flags; | |
5973 | struct rq *rq; | |
5974 | ||
5975 | rq = task_rq_lock(p, &flags); | |
77034937 IM |
5976 | if (rq->cfs.load.weight) |
5977 | time_slice = NS_TO_JIFFIES(sched_slice(&rq->cfs, se)); | |
a4ec24b4 DA |
5978 | task_rq_unlock(rq, &flags); |
5979 | } | |
1da177e4 | 5980 | read_unlock(&tasklist_lock); |
a4ec24b4 | 5981 | jiffies_to_timespec(time_slice, &t); |
1da177e4 | 5982 | retval = copy_to_user(interval, &t, sizeof(t)) ? -EFAULT : 0; |
1da177e4 | 5983 | return retval; |
3a5c359a | 5984 | |
1da177e4 LT |
5985 | out_unlock: |
5986 | read_unlock(&tasklist_lock); | |
5987 | return retval; | |
5988 | } | |
5989 | ||
7c731e0a | 5990 | static const char stat_nam[] = TASK_STATE_TO_CHAR_STR; |
36c8b586 | 5991 | |
82a1fcb9 | 5992 | void sched_show_task(struct task_struct *p) |
1da177e4 | 5993 | { |
1da177e4 | 5994 | unsigned long free = 0; |
36c8b586 | 5995 | unsigned state; |
1da177e4 | 5996 | |
1da177e4 | 5997 | state = p->state ? __ffs(p->state) + 1 : 0; |
cc4ea795 | 5998 | printk(KERN_INFO "%-13.13s %c", p->comm, |
2ed6e34f | 5999 | state < sizeof(stat_nam) - 1 ? stat_nam[state] : '?'); |
4bd77321 | 6000 | #if BITS_PER_LONG == 32 |
1da177e4 | 6001 | if (state == TASK_RUNNING) |
cc4ea795 | 6002 | printk(KERN_CONT " running "); |
1da177e4 | 6003 | else |
cc4ea795 | 6004 | printk(KERN_CONT " %08lx ", thread_saved_pc(p)); |
1da177e4 LT |
6005 | #else |
6006 | if (state == TASK_RUNNING) | |
cc4ea795 | 6007 | printk(KERN_CONT " running task "); |
1da177e4 | 6008 | else |
cc4ea795 | 6009 | printk(KERN_CONT " %016lx ", thread_saved_pc(p)); |
1da177e4 LT |
6010 | #endif |
6011 | #ifdef CONFIG_DEBUG_STACK_USAGE | |
7c9f8861 | 6012 | free = stack_not_used(p); |
1da177e4 | 6013 | #endif |
ba25f9dc | 6014 | printk(KERN_CONT "%5lu %5d %6d\n", free, |
fcfd50af | 6015 | task_pid_nr(p), task_pid_nr(p->real_parent)); |
1da177e4 | 6016 | |
5fb5e6de | 6017 | show_stack(p, NULL); |
1da177e4 LT |
6018 | } |
6019 | ||
e59e2ae2 | 6020 | void show_state_filter(unsigned long state_filter) |
1da177e4 | 6021 | { |
36c8b586 | 6022 | struct task_struct *g, *p; |
1da177e4 | 6023 | |
4bd77321 IM |
6024 | #if BITS_PER_LONG == 32 |
6025 | printk(KERN_INFO | |
6026 | " task PC stack pid father\n"); | |
1da177e4 | 6027 | #else |
4bd77321 IM |
6028 | printk(KERN_INFO |
6029 | " task PC stack pid father\n"); | |
1da177e4 LT |
6030 | #endif |
6031 | read_lock(&tasklist_lock); | |
6032 | do_each_thread(g, p) { | |
6033 | /* | |
6034 | * reset the NMI-timeout, listing all files on a slow | |
6035 | * console might take alot of time: | |
6036 | */ | |
6037 | touch_nmi_watchdog(); | |
39bc89fd | 6038 | if (!state_filter || (p->state & state_filter)) |
82a1fcb9 | 6039 | sched_show_task(p); |
1da177e4 LT |
6040 | } while_each_thread(g, p); |
6041 | ||
04c9167f JF |
6042 | touch_all_softlockup_watchdogs(); |
6043 | ||
dd41f596 IM |
6044 | #ifdef CONFIG_SCHED_DEBUG |
6045 | sysrq_sched_debug_show(); | |
6046 | #endif | |
1da177e4 | 6047 | read_unlock(&tasklist_lock); |
e59e2ae2 IM |
6048 | /* |
6049 | * Only show locks if all tasks are dumped: | |
6050 | */ | |
6051 | if (state_filter == -1) | |
6052 | debug_show_all_locks(); | |
1da177e4 LT |
6053 | } |
6054 | ||
1df21055 IM |
6055 | void __cpuinit init_idle_bootup_task(struct task_struct *idle) |
6056 | { | |
dd41f596 | 6057 | idle->sched_class = &idle_sched_class; |
1df21055 IM |
6058 | } |
6059 | ||
f340c0d1 IM |
6060 | /** |
6061 | * init_idle - set up an idle thread for a given CPU | |
6062 | * @idle: task in question | |
6063 | * @cpu: cpu the idle task belongs to | |
6064 | * | |
6065 | * NOTE: this function does not set the idle thread's NEED_RESCHED | |
6066 | * flag, to make booting more robust. | |
6067 | */ | |
5c1e1767 | 6068 | void __cpuinit init_idle(struct task_struct *idle, int cpu) |
1da177e4 | 6069 | { |
70b97a7f | 6070 | struct rq *rq = cpu_rq(cpu); |
1da177e4 LT |
6071 | unsigned long flags; |
6072 | ||
5cbd54ef IM |
6073 | spin_lock_irqsave(&rq->lock, flags); |
6074 | ||
dd41f596 IM |
6075 | __sched_fork(idle); |
6076 | idle->se.exec_start = sched_clock(); | |
6077 | ||
b29739f9 | 6078 | idle->prio = idle->normal_prio = MAX_PRIO; |
96f874e2 | 6079 | cpumask_copy(&idle->cpus_allowed, cpumask_of(cpu)); |
dd41f596 | 6080 | __set_task_cpu(idle, cpu); |
1da177e4 | 6081 | |
1da177e4 | 6082 | rq->curr = rq->idle = idle; |
4866cde0 NP |
6083 | #if defined(CONFIG_SMP) && defined(__ARCH_WANT_UNLOCKED_CTXSW) |
6084 | idle->oncpu = 1; | |
6085 | #endif | |
1da177e4 LT |
6086 | spin_unlock_irqrestore(&rq->lock, flags); |
6087 | ||
6088 | /* Set the preempt count _outside_ the spinlocks! */ | |
8e3e076c LT |
6089 | #if defined(CONFIG_PREEMPT) |
6090 | task_thread_info(idle)->preempt_count = (idle->lock_depth >= 0); | |
6091 | #else | |
a1261f54 | 6092 | task_thread_info(idle)->preempt_count = 0; |
8e3e076c | 6093 | #endif |
dd41f596 IM |
6094 | /* |
6095 | * The idle tasks have their own, simple scheduling class: | |
6096 | */ | |
6097 | idle->sched_class = &idle_sched_class; | |
fb52607a | 6098 | ftrace_graph_init_task(idle); |
1da177e4 LT |
6099 | } |
6100 | ||
6101 | /* | |
6102 | * In a system that switches off the HZ timer nohz_cpu_mask | |
6103 | * indicates which cpus entered this state. This is used | |
6104 | * in the rcu update to wait only for active cpus. For system | |
6105 | * which do not switch off the HZ timer nohz_cpu_mask should | |
6a7b3dc3 | 6106 | * always be CPU_BITS_NONE. |
1da177e4 | 6107 | */ |
6a7b3dc3 | 6108 | cpumask_var_t nohz_cpu_mask; |
1da177e4 | 6109 | |
19978ca6 IM |
6110 | /* |
6111 | * Increase the granularity value when there are more CPUs, | |
6112 | * because with more CPUs the 'effective latency' as visible | |
6113 | * to users decreases. But the relationship is not linear, | |
6114 | * so pick a second-best guess by going with the log2 of the | |
6115 | * number of CPUs. | |
6116 | * | |
6117 | * This idea comes from the SD scheduler of Con Kolivas: | |
6118 | */ | |
6119 | static inline void sched_init_granularity(void) | |
6120 | { | |
6121 | unsigned int factor = 1 + ilog2(num_online_cpus()); | |
6122 | const unsigned long limit = 200000000; | |
6123 | ||
6124 | sysctl_sched_min_granularity *= factor; | |
6125 | if (sysctl_sched_min_granularity > limit) | |
6126 | sysctl_sched_min_granularity = limit; | |
6127 | ||
6128 | sysctl_sched_latency *= factor; | |
6129 | if (sysctl_sched_latency > limit) | |
6130 | sysctl_sched_latency = limit; | |
6131 | ||
6132 | sysctl_sched_wakeup_granularity *= factor; | |
55cd5340 PZ |
6133 | |
6134 | sysctl_sched_shares_ratelimit *= factor; | |
19978ca6 IM |
6135 | } |
6136 | ||
1da177e4 LT |
6137 | #ifdef CONFIG_SMP |
6138 | /* | |
6139 | * This is how migration works: | |
6140 | * | |
70b97a7f | 6141 | * 1) we queue a struct migration_req structure in the source CPU's |
1da177e4 LT |
6142 | * runqueue and wake up that CPU's migration thread. |
6143 | * 2) we down() the locked semaphore => thread blocks. | |
6144 | * 3) migration thread wakes up (implicitly it forces the migrated | |
6145 | * thread off the CPU) | |
6146 | * 4) it gets the migration request and checks whether the migrated | |
6147 | * task is still in the wrong runqueue. | |
6148 | * 5) if it's in the wrong runqueue then the migration thread removes | |
6149 | * it and puts it into the right queue. | |
6150 | * 6) migration thread up()s the semaphore. | |
6151 | * 7) we wake up and the migration is done. | |
6152 | */ | |
6153 | ||
6154 | /* | |
6155 | * Change a given task's CPU affinity. Migrate the thread to a | |
6156 | * proper CPU and schedule it away if the CPU it's executing on | |
6157 | * is removed from the allowed bitmask. | |
6158 | * | |
6159 | * NOTE: the caller must have a valid reference to the task, the | |
41a2d6cf | 6160 | * task must not exit() & deallocate itself prematurely. The |
1da177e4 LT |
6161 | * call is not atomic; no spinlocks may be held. |
6162 | */ | |
96f874e2 | 6163 | int set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask) |
1da177e4 | 6164 | { |
70b97a7f | 6165 | struct migration_req req; |
1da177e4 | 6166 | unsigned long flags; |
70b97a7f | 6167 | struct rq *rq; |
48f24c4d | 6168 | int ret = 0; |
1da177e4 LT |
6169 | |
6170 | rq = task_rq_lock(p, &flags); | |
96f874e2 | 6171 | if (!cpumask_intersects(new_mask, cpu_online_mask)) { |
1da177e4 LT |
6172 | ret = -EINVAL; |
6173 | goto out; | |
6174 | } | |
6175 | ||
9985b0ba | 6176 | if (unlikely((p->flags & PF_THREAD_BOUND) && p != current && |
96f874e2 | 6177 | !cpumask_equal(&p->cpus_allowed, new_mask))) { |
9985b0ba DR |
6178 | ret = -EINVAL; |
6179 | goto out; | |
6180 | } | |
6181 | ||
73fe6aae | 6182 | if (p->sched_class->set_cpus_allowed) |
cd8ba7cd | 6183 | p->sched_class->set_cpus_allowed(p, new_mask); |
73fe6aae | 6184 | else { |
96f874e2 RR |
6185 | cpumask_copy(&p->cpus_allowed, new_mask); |
6186 | p->rt.nr_cpus_allowed = cpumask_weight(new_mask); | |
73fe6aae GH |
6187 | } |
6188 | ||
1da177e4 | 6189 | /* Can the task run on the task's current CPU? If so, we're done */ |
96f874e2 | 6190 | if (cpumask_test_cpu(task_cpu(p), new_mask)) |
1da177e4 LT |
6191 | goto out; |
6192 | ||
1e5ce4f4 | 6193 | if (migrate_task(p, cpumask_any_and(cpu_online_mask, new_mask), &req)) { |
1da177e4 LT |
6194 | /* Need help from migration thread: drop lock and wait. */ |
6195 | task_rq_unlock(rq, &flags); | |
6196 | wake_up_process(rq->migration_thread); | |
6197 | wait_for_completion(&req.done); | |
6198 | tlb_migrate_finish(p->mm); | |
6199 | return 0; | |
6200 | } | |
6201 | out: | |
6202 | task_rq_unlock(rq, &flags); | |
48f24c4d | 6203 | |
1da177e4 LT |
6204 | return ret; |
6205 | } | |
cd8ba7cd | 6206 | EXPORT_SYMBOL_GPL(set_cpus_allowed_ptr); |
1da177e4 LT |
6207 | |
6208 | /* | |
41a2d6cf | 6209 | * Move (not current) task off this cpu, onto dest cpu. We're doing |
1da177e4 LT |
6210 | * this because either it can't run here any more (set_cpus_allowed() |
6211 | * away from this CPU, or CPU going down), or because we're | |
6212 | * attempting to rebalance this task on exec (sched_exec). | |
6213 | * | |
6214 | * So we race with normal scheduler movements, but that's OK, as long | |
6215 | * as the task is no longer on this CPU. | |
efc30814 KK |
6216 | * |
6217 | * Returns non-zero if task was successfully migrated. | |
1da177e4 | 6218 | */ |
efc30814 | 6219 | static int __migrate_task(struct task_struct *p, int src_cpu, int dest_cpu) |
1da177e4 | 6220 | { |
70b97a7f | 6221 | struct rq *rq_dest, *rq_src; |
dd41f596 | 6222 | int ret = 0, on_rq; |
1da177e4 | 6223 | |
e761b772 | 6224 | if (unlikely(!cpu_active(dest_cpu))) |
efc30814 | 6225 | return ret; |
1da177e4 LT |
6226 | |
6227 | rq_src = cpu_rq(src_cpu); | |
6228 | rq_dest = cpu_rq(dest_cpu); | |
6229 | ||
6230 | double_rq_lock(rq_src, rq_dest); | |
6231 | /* Already moved. */ | |
6232 | if (task_cpu(p) != src_cpu) | |
b1e38734 | 6233 | goto done; |
1da177e4 | 6234 | /* Affinity changed (again). */ |
96f874e2 | 6235 | if (!cpumask_test_cpu(dest_cpu, &p->cpus_allowed)) |
b1e38734 | 6236 | goto fail; |
1da177e4 | 6237 | |
dd41f596 | 6238 | on_rq = p->se.on_rq; |
6e82a3be | 6239 | if (on_rq) |
2e1cb74a | 6240 | deactivate_task(rq_src, p, 0); |
6e82a3be | 6241 | |
1da177e4 | 6242 | set_task_cpu(p, dest_cpu); |
dd41f596 IM |
6243 | if (on_rq) { |
6244 | activate_task(rq_dest, p, 0); | |
15afe09b | 6245 | check_preempt_curr(rq_dest, p, 0); |
1da177e4 | 6246 | } |
b1e38734 | 6247 | done: |
efc30814 | 6248 | ret = 1; |
b1e38734 | 6249 | fail: |
1da177e4 | 6250 | double_rq_unlock(rq_src, rq_dest); |
efc30814 | 6251 | return ret; |
1da177e4 LT |
6252 | } |
6253 | ||
6254 | /* | |
6255 | * migration_thread - this is a highprio system thread that performs | |
6256 | * thread migration by bumping thread off CPU then 'pushing' onto | |
6257 | * another runqueue. | |
6258 | */ | |
95cdf3b7 | 6259 | static int migration_thread(void *data) |
1da177e4 | 6260 | { |
1da177e4 | 6261 | int cpu = (long)data; |
70b97a7f | 6262 | struct rq *rq; |
1da177e4 LT |
6263 | |
6264 | rq = cpu_rq(cpu); | |
6265 | BUG_ON(rq->migration_thread != current); | |
6266 | ||
6267 | set_current_state(TASK_INTERRUPTIBLE); | |
6268 | while (!kthread_should_stop()) { | |
70b97a7f | 6269 | struct migration_req *req; |
1da177e4 | 6270 | struct list_head *head; |
1da177e4 | 6271 | |
1da177e4 LT |
6272 | spin_lock_irq(&rq->lock); |
6273 | ||
6274 | if (cpu_is_offline(cpu)) { | |
6275 | spin_unlock_irq(&rq->lock); | |
6276 | goto wait_to_die; | |
6277 | } | |
6278 | ||
6279 | if (rq->active_balance) { | |
6280 | active_load_balance(rq, cpu); | |
6281 | rq->active_balance = 0; | |
6282 | } | |
6283 | ||
6284 | head = &rq->migration_queue; | |
6285 | ||
6286 | if (list_empty(head)) { | |
6287 | spin_unlock_irq(&rq->lock); | |
6288 | schedule(); | |
6289 | set_current_state(TASK_INTERRUPTIBLE); | |
6290 | continue; | |
6291 | } | |
70b97a7f | 6292 | req = list_entry(head->next, struct migration_req, list); |
1da177e4 LT |
6293 | list_del_init(head->next); |
6294 | ||
674311d5 NP |
6295 | spin_unlock(&rq->lock); |
6296 | __migrate_task(req->task, cpu, req->dest_cpu); | |
6297 | local_irq_enable(); | |
1da177e4 LT |
6298 | |
6299 | complete(&req->done); | |
6300 | } | |
6301 | __set_current_state(TASK_RUNNING); | |
6302 | return 0; | |
6303 | ||
6304 | wait_to_die: | |
6305 | /* Wait for kthread_stop */ | |
6306 | set_current_state(TASK_INTERRUPTIBLE); | |
6307 | while (!kthread_should_stop()) { | |
6308 | schedule(); | |
6309 | set_current_state(TASK_INTERRUPTIBLE); | |
6310 | } | |
6311 | __set_current_state(TASK_RUNNING); | |
6312 | return 0; | |
6313 | } | |
6314 | ||
6315 | #ifdef CONFIG_HOTPLUG_CPU | |
f7b4cddc ON |
6316 | |
6317 | static int __migrate_task_irq(struct task_struct *p, int src_cpu, int dest_cpu) | |
6318 | { | |
6319 | int ret; | |
6320 | ||
6321 | local_irq_disable(); | |
6322 | ret = __migrate_task(p, src_cpu, dest_cpu); | |
6323 | local_irq_enable(); | |
6324 | return ret; | |
6325 | } | |
6326 | ||
054b9108 | 6327 | /* |
3a4fa0a2 | 6328 | * Figure out where task on dead CPU should go, use force if necessary. |
054b9108 | 6329 | */ |
48f24c4d | 6330 | static void move_task_off_dead_cpu(int dead_cpu, struct task_struct *p) |
1da177e4 | 6331 | { |
70b97a7f | 6332 | int dest_cpu; |
6ca09dfc | 6333 | const struct cpumask *nodemask = cpumask_of_node(cpu_to_node(dead_cpu)); |
1da177e4 | 6334 | |
e76bd8d9 RR |
6335 | again: |
6336 | /* Look for allowed, online CPU in same node. */ | |
6337 | for_each_cpu_and(dest_cpu, nodemask, cpu_online_mask) | |
6338 | if (cpumask_test_cpu(dest_cpu, &p->cpus_allowed)) | |
6339 | goto move; | |
3a5c359a | 6340 | |
e76bd8d9 RR |
6341 | /* Any allowed, online CPU? */ |
6342 | dest_cpu = cpumask_any_and(&p->cpus_allowed, cpu_online_mask); | |
6343 | if (dest_cpu < nr_cpu_ids) | |
6344 | goto move; | |
3a5c359a | 6345 | |
e76bd8d9 RR |
6346 | /* No more Mr. Nice Guy. */ |
6347 | if (dest_cpu >= nr_cpu_ids) { | |
e76bd8d9 RR |
6348 | cpuset_cpus_allowed_locked(p, &p->cpus_allowed); |
6349 | dest_cpu = cpumask_any_and(cpu_online_mask, &p->cpus_allowed); | |
1da177e4 | 6350 | |
e76bd8d9 RR |
6351 | /* |
6352 | * Don't tell them about moving exiting tasks or | |
6353 | * kernel threads (both mm NULL), since they never | |
6354 | * leave kernel. | |
6355 | */ | |
6356 | if (p->mm && printk_ratelimit()) { | |
6357 | printk(KERN_INFO "process %d (%s) no " | |
6358 | "longer affine to cpu%d\n", | |
6359 | task_pid_nr(p), p->comm, dead_cpu); | |
3a5c359a | 6360 | } |
e76bd8d9 RR |
6361 | } |
6362 | ||
6363 | move: | |
6364 | /* It can have affinity changed while we were choosing. */ | |
6365 | if (unlikely(!__migrate_task_irq(p, dead_cpu, dest_cpu))) | |
6366 | goto again; | |
1da177e4 LT |
6367 | } |
6368 | ||
6369 | /* | |
6370 | * While a dead CPU has no uninterruptible tasks queued at this point, | |
6371 | * it might still have a nonzero ->nr_uninterruptible counter, because | |
6372 | * for performance reasons the counter is not stricly tracking tasks to | |
6373 | * their home CPUs. So we just add the counter to another CPU's counter, | |
6374 | * to keep the global sum constant after CPU-down: | |
6375 | */ | |
70b97a7f | 6376 | static void migrate_nr_uninterruptible(struct rq *rq_src) |
1da177e4 | 6377 | { |
1e5ce4f4 | 6378 | struct rq *rq_dest = cpu_rq(cpumask_any(cpu_online_mask)); |
1da177e4 LT |
6379 | unsigned long flags; |
6380 | ||
6381 | local_irq_save(flags); | |
6382 | double_rq_lock(rq_src, rq_dest); | |
6383 | rq_dest->nr_uninterruptible += rq_src->nr_uninterruptible; | |
6384 | rq_src->nr_uninterruptible = 0; | |
6385 | double_rq_unlock(rq_src, rq_dest); | |
6386 | local_irq_restore(flags); | |
6387 | } | |
6388 | ||
6389 | /* Run through task list and migrate tasks from the dead cpu. */ | |
6390 | static void migrate_live_tasks(int src_cpu) | |
6391 | { | |
48f24c4d | 6392 | struct task_struct *p, *t; |
1da177e4 | 6393 | |
f7b4cddc | 6394 | read_lock(&tasklist_lock); |
1da177e4 | 6395 | |
48f24c4d IM |
6396 | do_each_thread(t, p) { |
6397 | if (p == current) | |
1da177e4 LT |
6398 | continue; |
6399 | ||
48f24c4d IM |
6400 | if (task_cpu(p) == src_cpu) |
6401 | move_task_off_dead_cpu(src_cpu, p); | |
6402 | } while_each_thread(t, p); | |
1da177e4 | 6403 | |
f7b4cddc | 6404 | read_unlock(&tasklist_lock); |
1da177e4 LT |
6405 | } |
6406 | ||
dd41f596 IM |
6407 | /* |
6408 | * Schedules idle task to be the next runnable task on current CPU. | |
94bc9a7b DA |
6409 | * It does so by boosting its priority to highest possible. |
6410 | * Used by CPU offline code. | |
1da177e4 LT |
6411 | */ |
6412 | void sched_idle_next(void) | |
6413 | { | |
48f24c4d | 6414 | int this_cpu = smp_processor_id(); |
70b97a7f | 6415 | struct rq *rq = cpu_rq(this_cpu); |
1da177e4 LT |
6416 | struct task_struct *p = rq->idle; |
6417 | unsigned long flags; | |
6418 | ||
6419 | /* cpu has to be offline */ | |
48f24c4d | 6420 | BUG_ON(cpu_online(this_cpu)); |
1da177e4 | 6421 | |
48f24c4d IM |
6422 | /* |
6423 | * Strictly not necessary since rest of the CPUs are stopped by now | |
6424 | * and interrupts disabled on the current cpu. | |
1da177e4 LT |
6425 | */ |
6426 | spin_lock_irqsave(&rq->lock, flags); | |
6427 | ||
dd41f596 | 6428 | __setscheduler(rq, p, SCHED_FIFO, MAX_RT_PRIO-1); |
48f24c4d | 6429 | |
94bc9a7b DA |
6430 | update_rq_clock(rq); |
6431 | activate_task(rq, p, 0); | |
1da177e4 LT |
6432 | |
6433 | spin_unlock_irqrestore(&rq->lock, flags); | |
6434 | } | |
6435 | ||
48f24c4d IM |
6436 | /* |
6437 | * Ensures that the idle task is using init_mm right before its cpu goes | |
1da177e4 LT |
6438 | * offline. |
6439 | */ | |
6440 | void idle_task_exit(void) | |
6441 | { | |
6442 | struct mm_struct *mm = current->active_mm; | |
6443 | ||
6444 | BUG_ON(cpu_online(smp_processor_id())); | |
6445 | ||
6446 | if (mm != &init_mm) | |
6447 | switch_mm(mm, &init_mm, current); | |
6448 | mmdrop(mm); | |
6449 | } | |
6450 | ||
054b9108 | 6451 | /* called under rq->lock with disabled interrupts */ |
36c8b586 | 6452 | static void migrate_dead(unsigned int dead_cpu, struct task_struct *p) |
1da177e4 | 6453 | { |
70b97a7f | 6454 | struct rq *rq = cpu_rq(dead_cpu); |
1da177e4 LT |
6455 | |
6456 | /* Must be exiting, otherwise would be on tasklist. */ | |
270f722d | 6457 | BUG_ON(!p->exit_state); |
1da177e4 LT |
6458 | |
6459 | /* Cannot have done final schedule yet: would have vanished. */ | |
c394cc9f | 6460 | BUG_ON(p->state == TASK_DEAD); |
1da177e4 | 6461 | |
48f24c4d | 6462 | get_task_struct(p); |
1da177e4 LT |
6463 | |
6464 | /* | |
6465 | * Drop lock around migration; if someone else moves it, | |
41a2d6cf | 6466 | * that's OK. No task can be added to this CPU, so iteration is |
1da177e4 LT |
6467 | * fine. |
6468 | */ | |
f7b4cddc | 6469 | spin_unlock_irq(&rq->lock); |
48f24c4d | 6470 | move_task_off_dead_cpu(dead_cpu, p); |
f7b4cddc | 6471 | spin_lock_irq(&rq->lock); |
1da177e4 | 6472 | |
48f24c4d | 6473 | put_task_struct(p); |
1da177e4 LT |
6474 | } |
6475 | ||
6476 | /* release_task() removes task from tasklist, so we won't find dead tasks. */ | |
6477 | static void migrate_dead_tasks(unsigned int dead_cpu) | |
6478 | { | |
70b97a7f | 6479 | struct rq *rq = cpu_rq(dead_cpu); |
dd41f596 | 6480 | struct task_struct *next; |
48f24c4d | 6481 | |
dd41f596 IM |
6482 | for ( ; ; ) { |
6483 | if (!rq->nr_running) | |
6484 | break; | |
a8e504d2 | 6485 | update_rq_clock(rq); |
ff95f3df | 6486 | next = pick_next_task(rq, rq->curr); |
dd41f596 IM |
6487 | if (!next) |
6488 | break; | |
79c53799 | 6489 | next->sched_class->put_prev_task(rq, next); |
dd41f596 | 6490 | migrate_dead(dead_cpu, next); |
e692ab53 | 6491 | |
1da177e4 LT |
6492 | } |
6493 | } | |
6494 | #endif /* CONFIG_HOTPLUG_CPU */ | |
6495 | ||
e692ab53 NP |
6496 | #if defined(CONFIG_SCHED_DEBUG) && defined(CONFIG_SYSCTL) |
6497 | ||
6498 | static struct ctl_table sd_ctl_dir[] = { | |
e0361851 AD |
6499 | { |
6500 | .procname = "sched_domain", | |
c57baf1e | 6501 | .mode = 0555, |
e0361851 | 6502 | }, |
38605cae | 6503 | {0, }, |
e692ab53 NP |
6504 | }; |
6505 | ||
6506 | static struct ctl_table sd_ctl_root[] = { | |
e0361851 | 6507 | { |
c57baf1e | 6508 | .ctl_name = CTL_KERN, |
e0361851 | 6509 | .procname = "kernel", |
c57baf1e | 6510 | .mode = 0555, |
e0361851 AD |
6511 | .child = sd_ctl_dir, |
6512 | }, | |
38605cae | 6513 | {0, }, |
e692ab53 NP |
6514 | }; |
6515 | ||
6516 | static struct ctl_table *sd_alloc_ctl_entry(int n) | |
6517 | { | |
6518 | struct ctl_table *entry = | |
5cf9f062 | 6519 | kcalloc(n, sizeof(struct ctl_table), GFP_KERNEL); |
e692ab53 | 6520 | |
e692ab53 NP |
6521 | return entry; |
6522 | } | |
6523 | ||
6382bc90 MM |
6524 | static void sd_free_ctl_entry(struct ctl_table **tablep) |
6525 | { | |
cd790076 | 6526 | struct ctl_table *entry; |
6382bc90 | 6527 | |
cd790076 MM |
6528 | /* |
6529 | * In the intermediate directories, both the child directory and | |
6530 | * procname are dynamically allocated and could fail but the mode | |
41a2d6cf | 6531 | * will always be set. In the lowest directory the names are |
cd790076 MM |
6532 | * static strings and all have proc handlers. |
6533 | */ | |
6534 | for (entry = *tablep; entry->mode; entry++) { | |
6382bc90 MM |
6535 | if (entry->child) |
6536 | sd_free_ctl_entry(&entry->child); | |
cd790076 MM |
6537 | if (entry->proc_handler == NULL) |
6538 | kfree(entry->procname); | |
6539 | } | |
6382bc90 MM |
6540 | |
6541 | kfree(*tablep); | |
6542 | *tablep = NULL; | |
6543 | } | |
6544 | ||
e692ab53 | 6545 | static void |
e0361851 | 6546 | set_table_entry(struct ctl_table *entry, |
e692ab53 NP |
6547 | const char *procname, void *data, int maxlen, |
6548 | mode_t mode, proc_handler *proc_handler) | |
6549 | { | |
e692ab53 NP |
6550 | entry->procname = procname; |
6551 | entry->data = data; | |
6552 | entry->maxlen = maxlen; | |
6553 | entry->mode = mode; | |
6554 | entry->proc_handler = proc_handler; | |
6555 | } | |
6556 | ||
6557 | static struct ctl_table * | |
6558 | sd_alloc_ctl_domain_table(struct sched_domain *sd) | |
6559 | { | |
a5d8c348 | 6560 | struct ctl_table *table = sd_alloc_ctl_entry(13); |
e692ab53 | 6561 | |
ad1cdc1d MM |
6562 | if (table == NULL) |
6563 | return NULL; | |
6564 | ||
e0361851 | 6565 | set_table_entry(&table[0], "min_interval", &sd->min_interval, |
e692ab53 | 6566 | sizeof(long), 0644, proc_doulongvec_minmax); |
e0361851 | 6567 | set_table_entry(&table[1], "max_interval", &sd->max_interval, |
e692ab53 | 6568 | sizeof(long), 0644, proc_doulongvec_minmax); |
e0361851 | 6569 | set_table_entry(&table[2], "busy_idx", &sd->busy_idx, |
e692ab53 | 6570 | sizeof(int), 0644, proc_dointvec_minmax); |
e0361851 | 6571 | set_table_entry(&table[3], "idle_idx", &sd->idle_idx, |
e692ab53 | 6572 | sizeof(int), 0644, proc_dointvec_minmax); |
e0361851 | 6573 | set_table_entry(&table[4], "newidle_idx", &sd->newidle_idx, |
e692ab53 | 6574 | sizeof(int), 0644, proc_dointvec_minmax); |
e0361851 | 6575 | set_table_entry(&table[5], "wake_idx", &sd->wake_idx, |
e692ab53 | 6576 | sizeof(int), 0644, proc_dointvec_minmax); |
e0361851 | 6577 | set_table_entry(&table[6], "forkexec_idx", &sd->forkexec_idx, |
e692ab53 | 6578 | sizeof(int), 0644, proc_dointvec_minmax); |
e0361851 | 6579 | set_table_entry(&table[7], "busy_factor", &sd->busy_factor, |
e692ab53 | 6580 | sizeof(int), 0644, proc_dointvec_minmax); |
e0361851 | 6581 | set_table_entry(&table[8], "imbalance_pct", &sd->imbalance_pct, |
e692ab53 | 6582 | sizeof(int), 0644, proc_dointvec_minmax); |
ace8b3d6 | 6583 | set_table_entry(&table[9], "cache_nice_tries", |
e692ab53 NP |
6584 | &sd->cache_nice_tries, |
6585 | sizeof(int), 0644, proc_dointvec_minmax); | |
ace8b3d6 | 6586 | set_table_entry(&table[10], "flags", &sd->flags, |
e692ab53 | 6587 | sizeof(int), 0644, proc_dointvec_minmax); |
a5d8c348 IM |
6588 | set_table_entry(&table[11], "name", sd->name, |
6589 | CORENAME_MAX_SIZE, 0444, proc_dostring); | |
6590 | /* &table[12] is terminator */ | |
e692ab53 NP |
6591 | |
6592 | return table; | |
6593 | } | |
6594 | ||
9a4e7159 | 6595 | static ctl_table *sd_alloc_ctl_cpu_table(int cpu) |
e692ab53 NP |
6596 | { |
6597 | struct ctl_table *entry, *table; | |
6598 | struct sched_domain *sd; | |
6599 | int domain_num = 0, i; | |
6600 | char buf[32]; | |
6601 | ||
6602 | for_each_domain(cpu, sd) | |
6603 | domain_num++; | |
6604 | entry = table = sd_alloc_ctl_entry(domain_num + 1); | |
ad1cdc1d MM |
6605 | if (table == NULL) |
6606 | return NULL; | |
e692ab53 NP |
6607 | |
6608 | i = 0; | |
6609 | for_each_domain(cpu, sd) { | |
6610 | snprintf(buf, 32, "domain%d", i); | |
e692ab53 | 6611 | entry->procname = kstrdup(buf, GFP_KERNEL); |
c57baf1e | 6612 | entry->mode = 0555; |
e692ab53 NP |
6613 | entry->child = sd_alloc_ctl_domain_table(sd); |
6614 | entry++; | |
6615 | i++; | |
6616 | } | |
6617 | return table; | |
6618 | } | |
6619 | ||
6620 | static struct ctl_table_header *sd_sysctl_header; | |
6382bc90 | 6621 | static void register_sched_domain_sysctl(void) |
e692ab53 NP |
6622 | { |
6623 | int i, cpu_num = num_online_cpus(); | |
6624 | struct ctl_table *entry = sd_alloc_ctl_entry(cpu_num + 1); | |
6625 | char buf[32]; | |
6626 | ||
7378547f MM |
6627 | WARN_ON(sd_ctl_dir[0].child); |
6628 | sd_ctl_dir[0].child = entry; | |
6629 | ||
ad1cdc1d MM |
6630 | if (entry == NULL) |
6631 | return; | |
6632 | ||
97b6ea7b | 6633 | for_each_online_cpu(i) { |
e692ab53 | 6634 | snprintf(buf, 32, "cpu%d", i); |
e692ab53 | 6635 | entry->procname = kstrdup(buf, GFP_KERNEL); |
c57baf1e | 6636 | entry->mode = 0555; |
e692ab53 | 6637 | entry->child = sd_alloc_ctl_cpu_table(i); |
97b6ea7b | 6638 | entry++; |
e692ab53 | 6639 | } |
7378547f MM |
6640 | |
6641 | WARN_ON(sd_sysctl_header); | |
e692ab53 NP |
6642 | sd_sysctl_header = register_sysctl_table(sd_ctl_root); |
6643 | } | |
6382bc90 | 6644 | |
7378547f | 6645 | /* may be called multiple times per register */ |
6382bc90 MM |
6646 | static void unregister_sched_domain_sysctl(void) |
6647 | { | |
7378547f MM |
6648 | if (sd_sysctl_header) |
6649 | unregister_sysctl_table(sd_sysctl_header); | |
6382bc90 | 6650 | sd_sysctl_header = NULL; |
7378547f MM |
6651 | if (sd_ctl_dir[0].child) |
6652 | sd_free_ctl_entry(&sd_ctl_dir[0].child); | |
6382bc90 | 6653 | } |
e692ab53 | 6654 | #else |
6382bc90 MM |
6655 | static void register_sched_domain_sysctl(void) |
6656 | { | |
6657 | } | |
6658 | static void unregister_sched_domain_sysctl(void) | |
e692ab53 NP |
6659 | { |
6660 | } | |
6661 | #endif | |
6662 | ||
1f11eb6a GH |
6663 | static void set_rq_online(struct rq *rq) |
6664 | { | |
6665 | if (!rq->online) { | |
6666 | const struct sched_class *class; | |
6667 | ||
c6c4927b | 6668 | cpumask_set_cpu(rq->cpu, rq->rd->online); |
1f11eb6a GH |
6669 | rq->online = 1; |
6670 | ||
6671 | for_each_class(class) { | |
6672 | if (class->rq_online) | |
6673 | class->rq_online(rq); | |
6674 | } | |
6675 | } | |
6676 | } | |
6677 | ||
6678 | static void set_rq_offline(struct rq *rq) | |
6679 | { | |
6680 | if (rq->online) { | |
6681 | const struct sched_class *class; | |
6682 | ||
6683 | for_each_class(class) { | |
6684 | if (class->rq_offline) | |
6685 | class->rq_offline(rq); | |
6686 | } | |
6687 | ||
c6c4927b | 6688 | cpumask_clear_cpu(rq->cpu, rq->rd->online); |
1f11eb6a GH |
6689 | rq->online = 0; |
6690 | } | |
6691 | } | |
6692 | ||
1da177e4 LT |
6693 | /* |
6694 | * migration_call - callback that gets triggered when a CPU is added. | |
6695 | * Here we can start up the necessary migration thread for the new CPU. | |
6696 | */ | |
48f24c4d IM |
6697 | static int __cpuinit |
6698 | migration_call(struct notifier_block *nfb, unsigned long action, void *hcpu) | |
1da177e4 | 6699 | { |
1da177e4 | 6700 | struct task_struct *p; |
48f24c4d | 6701 | int cpu = (long)hcpu; |
1da177e4 | 6702 | unsigned long flags; |
70b97a7f | 6703 | struct rq *rq; |
1da177e4 LT |
6704 | |
6705 | switch (action) { | |
5be9361c | 6706 | |
1da177e4 | 6707 | case CPU_UP_PREPARE: |
8bb78442 | 6708 | case CPU_UP_PREPARE_FROZEN: |
dd41f596 | 6709 | p = kthread_create(migration_thread, hcpu, "migration/%d", cpu); |
1da177e4 LT |
6710 | if (IS_ERR(p)) |
6711 | return NOTIFY_BAD; | |
1da177e4 LT |
6712 | kthread_bind(p, cpu); |
6713 | /* Must be high prio: stop_machine expects to yield to it. */ | |
6714 | rq = task_rq_lock(p, &flags); | |
dd41f596 | 6715 | __setscheduler(rq, p, SCHED_FIFO, MAX_RT_PRIO-1); |
1da177e4 LT |
6716 | task_rq_unlock(rq, &flags); |
6717 | cpu_rq(cpu)->migration_thread = p; | |
6718 | break; | |
48f24c4d | 6719 | |
1da177e4 | 6720 | case CPU_ONLINE: |
8bb78442 | 6721 | case CPU_ONLINE_FROZEN: |
3a4fa0a2 | 6722 | /* Strictly unnecessary, as first user will wake it. */ |
1da177e4 | 6723 | wake_up_process(cpu_rq(cpu)->migration_thread); |
1f94ef59 GH |
6724 | |
6725 | /* Update our root-domain */ | |
6726 | rq = cpu_rq(cpu); | |
6727 | spin_lock_irqsave(&rq->lock, flags); | |
6728 | if (rq->rd) { | |
c6c4927b | 6729 | BUG_ON(!cpumask_test_cpu(cpu, rq->rd->span)); |
1f11eb6a GH |
6730 | |
6731 | set_rq_online(rq); | |
1f94ef59 GH |
6732 | } |
6733 | spin_unlock_irqrestore(&rq->lock, flags); | |
1da177e4 | 6734 | break; |
48f24c4d | 6735 | |
1da177e4 LT |
6736 | #ifdef CONFIG_HOTPLUG_CPU |
6737 | case CPU_UP_CANCELED: | |
8bb78442 | 6738 | case CPU_UP_CANCELED_FROZEN: |
fc75cdfa HC |
6739 | if (!cpu_rq(cpu)->migration_thread) |
6740 | break; | |
41a2d6cf | 6741 | /* Unbind it from offline cpu so it can run. Fall thru. */ |
a4c4af7c | 6742 | kthread_bind(cpu_rq(cpu)->migration_thread, |
1e5ce4f4 | 6743 | cpumask_any(cpu_online_mask)); |
1da177e4 LT |
6744 | kthread_stop(cpu_rq(cpu)->migration_thread); |
6745 | cpu_rq(cpu)->migration_thread = NULL; | |
6746 | break; | |
48f24c4d | 6747 | |
1da177e4 | 6748 | case CPU_DEAD: |
8bb78442 | 6749 | case CPU_DEAD_FROZEN: |
470fd646 | 6750 | cpuset_lock(); /* around calls to cpuset_cpus_allowed_lock() */ |
1da177e4 LT |
6751 | migrate_live_tasks(cpu); |
6752 | rq = cpu_rq(cpu); | |
6753 | kthread_stop(rq->migration_thread); | |
6754 | rq->migration_thread = NULL; | |
6755 | /* Idle task back to normal (off runqueue, low prio) */ | |
d2da272a | 6756 | spin_lock_irq(&rq->lock); |
a8e504d2 | 6757 | update_rq_clock(rq); |
2e1cb74a | 6758 | deactivate_task(rq, rq->idle, 0); |
1da177e4 | 6759 | rq->idle->static_prio = MAX_PRIO; |
dd41f596 IM |
6760 | __setscheduler(rq, rq->idle, SCHED_NORMAL, 0); |
6761 | rq->idle->sched_class = &idle_sched_class; | |
1da177e4 | 6762 | migrate_dead_tasks(cpu); |
d2da272a | 6763 | spin_unlock_irq(&rq->lock); |
470fd646 | 6764 | cpuset_unlock(); |
1da177e4 LT |
6765 | migrate_nr_uninterruptible(rq); |
6766 | BUG_ON(rq->nr_running != 0); | |
6767 | ||
41a2d6cf IM |
6768 | /* |
6769 | * No need to migrate the tasks: it was best-effort if | |
6770 | * they didn't take sched_hotcpu_mutex. Just wake up | |
6771 | * the requestors. | |
6772 | */ | |
1da177e4 LT |
6773 | spin_lock_irq(&rq->lock); |
6774 | while (!list_empty(&rq->migration_queue)) { | |
70b97a7f IM |
6775 | struct migration_req *req; |
6776 | ||
1da177e4 | 6777 | req = list_entry(rq->migration_queue.next, |
70b97a7f | 6778 | struct migration_req, list); |
1da177e4 | 6779 | list_del_init(&req->list); |
9a2bd244 | 6780 | spin_unlock_irq(&rq->lock); |
1da177e4 | 6781 | complete(&req->done); |
9a2bd244 | 6782 | spin_lock_irq(&rq->lock); |
1da177e4 LT |
6783 | } |
6784 | spin_unlock_irq(&rq->lock); | |
6785 | break; | |
57d885fe | 6786 | |
08f503b0 GH |
6787 | case CPU_DYING: |
6788 | case CPU_DYING_FROZEN: | |
57d885fe GH |
6789 | /* Update our root-domain */ |
6790 | rq = cpu_rq(cpu); | |
6791 | spin_lock_irqsave(&rq->lock, flags); | |
6792 | if (rq->rd) { | |
c6c4927b | 6793 | BUG_ON(!cpumask_test_cpu(cpu, rq->rd->span)); |
1f11eb6a | 6794 | set_rq_offline(rq); |
57d885fe GH |
6795 | } |
6796 | spin_unlock_irqrestore(&rq->lock, flags); | |
6797 | break; | |
1da177e4 LT |
6798 | #endif |
6799 | } | |
6800 | return NOTIFY_OK; | |
6801 | } | |
6802 | ||
6803 | /* Register at highest priority so that task migration (migrate_all_tasks) | |
6804 | * happens before everything else. | |
6805 | */ | |
26c2143b | 6806 | static struct notifier_block __cpuinitdata migration_notifier = { |
1da177e4 LT |
6807 | .notifier_call = migration_call, |
6808 | .priority = 10 | |
6809 | }; | |
6810 | ||
7babe8db | 6811 | static int __init migration_init(void) |
1da177e4 LT |
6812 | { |
6813 | void *cpu = (void *)(long)smp_processor_id(); | |
07dccf33 | 6814 | int err; |
48f24c4d IM |
6815 | |
6816 | /* Start one for the boot CPU: */ | |
07dccf33 AM |
6817 | err = migration_call(&migration_notifier, CPU_UP_PREPARE, cpu); |
6818 | BUG_ON(err == NOTIFY_BAD); | |
1da177e4 LT |
6819 | migration_call(&migration_notifier, CPU_ONLINE, cpu); |
6820 | register_cpu_notifier(&migration_notifier); | |
7babe8db EGM |
6821 | |
6822 | return err; | |
1da177e4 | 6823 | } |
7babe8db | 6824 | early_initcall(migration_init); |
1da177e4 LT |
6825 | #endif |
6826 | ||
6827 | #ifdef CONFIG_SMP | |
476f3534 | 6828 | |
3e9830dc | 6829 | #ifdef CONFIG_SCHED_DEBUG |
4dcf6aff | 6830 | |
7c16ec58 | 6831 | static int sched_domain_debug_one(struct sched_domain *sd, int cpu, int level, |
96f874e2 | 6832 | struct cpumask *groupmask) |
1da177e4 | 6833 | { |
4dcf6aff | 6834 | struct sched_group *group = sd->groups; |
434d53b0 | 6835 | char str[256]; |
1da177e4 | 6836 | |
968ea6d8 | 6837 | cpulist_scnprintf(str, sizeof(str), sched_domain_span(sd)); |
96f874e2 | 6838 | cpumask_clear(groupmask); |
4dcf6aff IM |
6839 | |
6840 | printk(KERN_DEBUG "%*s domain %d: ", level, "", level); | |
6841 | ||
6842 | if (!(sd->flags & SD_LOAD_BALANCE)) { | |
6843 | printk("does not load-balance\n"); | |
6844 | if (sd->parent) | |
6845 | printk(KERN_ERR "ERROR: !SD_LOAD_BALANCE domain" | |
6846 | " has parent"); | |
6847 | return -1; | |
41c7ce9a NP |
6848 | } |
6849 | ||
eefd796a | 6850 | printk(KERN_CONT "span %s level %s\n", str, sd->name); |
4dcf6aff | 6851 | |
758b2cdc | 6852 | if (!cpumask_test_cpu(cpu, sched_domain_span(sd))) { |
4dcf6aff IM |
6853 | printk(KERN_ERR "ERROR: domain->span does not contain " |
6854 | "CPU%d\n", cpu); | |
6855 | } | |
758b2cdc | 6856 | if (!cpumask_test_cpu(cpu, sched_group_cpus(group))) { |
4dcf6aff IM |
6857 | printk(KERN_ERR "ERROR: domain->groups does not contain" |
6858 | " CPU%d\n", cpu); | |
6859 | } | |
1da177e4 | 6860 | |
4dcf6aff | 6861 | printk(KERN_DEBUG "%*s groups:", level + 1, ""); |
1da177e4 | 6862 | do { |
4dcf6aff IM |
6863 | if (!group) { |
6864 | printk("\n"); | |
6865 | printk(KERN_ERR "ERROR: group is NULL\n"); | |
1da177e4 LT |
6866 | break; |
6867 | } | |
6868 | ||
4dcf6aff IM |
6869 | if (!group->__cpu_power) { |
6870 | printk(KERN_CONT "\n"); | |
6871 | printk(KERN_ERR "ERROR: domain->cpu_power not " | |
6872 | "set\n"); | |
6873 | break; | |
6874 | } | |
1da177e4 | 6875 | |
758b2cdc | 6876 | if (!cpumask_weight(sched_group_cpus(group))) { |
4dcf6aff IM |
6877 | printk(KERN_CONT "\n"); |
6878 | printk(KERN_ERR "ERROR: empty group\n"); | |
6879 | break; | |
6880 | } | |
1da177e4 | 6881 | |
758b2cdc | 6882 | if (cpumask_intersects(groupmask, sched_group_cpus(group))) { |
4dcf6aff IM |
6883 | printk(KERN_CONT "\n"); |
6884 | printk(KERN_ERR "ERROR: repeated CPUs\n"); | |
6885 | break; | |
6886 | } | |
1da177e4 | 6887 | |
758b2cdc | 6888 | cpumask_or(groupmask, groupmask, sched_group_cpus(group)); |
1da177e4 | 6889 | |
968ea6d8 | 6890 | cpulist_scnprintf(str, sizeof(str), sched_group_cpus(group)); |
4dcf6aff | 6891 | printk(KERN_CONT " %s", str); |
1da177e4 | 6892 | |
4dcf6aff IM |
6893 | group = group->next; |
6894 | } while (group != sd->groups); | |
6895 | printk(KERN_CONT "\n"); | |
1da177e4 | 6896 | |
758b2cdc | 6897 | if (!cpumask_equal(sched_domain_span(sd), groupmask)) |
4dcf6aff | 6898 | printk(KERN_ERR "ERROR: groups don't span domain->span\n"); |
1da177e4 | 6899 | |
758b2cdc RR |
6900 | if (sd->parent && |
6901 | !cpumask_subset(groupmask, sched_domain_span(sd->parent))) | |
4dcf6aff IM |
6902 | printk(KERN_ERR "ERROR: parent span is not a superset " |
6903 | "of domain->span\n"); | |
6904 | return 0; | |
6905 | } | |
1da177e4 | 6906 | |
4dcf6aff IM |
6907 | static void sched_domain_debug(struct sched_domain *sd, int cpu) |
6908 | { | |
d5dd3db1 | 6909 | cpumask_var_t groupmask; |
4dcf6aff | 6910 | int level = 0; |
1da177e4 | 6911 | |
4dcf6aff IM |
6912 | if (!sd) { |
6913 | printk(KERN_DEBUG "CPU%d attaching NULL sched-domain.\n", cpu); | |
6914 | return; | |
6915 | } | |
1da177e4 | 6916 | |
4dcf6aff IM |
6917 | printk(KERN_DEBUG "CPU%d attaching sched-domain:\n", cpu); |
6918 | ||
d5dd3db1 | 6919 | if (!alloc_cpumask_var(&groupmask, GFP_KERNEL)) { |
7c16ec58 MT |
6920 | printk(KERN_DEBUG "Cannot load-balance (out of memory)\n"); |
6921 | return; | |
6922 | } | |
6923 | ||
4dcf6aff | 6924 | for (;;) { |
7c16ec58 | 6925 | if (sched_domain_debug_one(sd, cpu, level, groupmask)) |
4dcf6aff | 6926 | break; |
1da177e4 LT |
6927 | level++; |
6928 | sd = sd->parent; | |
33859f7f | 6929 | if (!sd) |
4dcf6aff IM |
6930 | break; |
6931 | } | |
d5dd3db1 | 6932 | free_cpumask_var(groupmask); |
1da177e4 | 6933 | } |
6d6bc0ad | 6934 | #else /* !CONFIG_SCHED_DEBUG */ |
48f24c4d | 6935 | # define sched_domain_debug(sd, cpu) do { } while (0) |
6d6bc0ad | 6936 | #endif /* CONFIG_SCHED_DEBUG */ |
1da177e4 | 6937 | |
1a20ff27 | 6938 | static int sd_degenerate(struct sched_domain *sd) |
245af2c7 | 6939 | { |
758b2cdc | 6940 | if (cpumask_weight(sched_domain_span(sd)) == 1) |
245af2c7 SS |
6941 | return 1; |
6942 | ||
6943 | /* Following flags need at least 2 groups */ | |
6944 | if (sd->flags & (SD_LOAD_BALANCE | | |
6945 | SD_BALANCE_NEWIDLE | | |
6946 | SD_BALANCE_FORK | | |
89c4710e SS |
6947 | SD_BALANCE_EXEC | |
6948 | SD_SHARE_CPUPOWER | | |
6949 | SD_SHARE_PKG_RESOURCES)) { | |
245af2c7 SS |
6950 | if (sd->groups != sd->groups->next) |
6951 | return 0; | |
6952 | } | |
6953 | ||
6954 | /* Following flags don't use groups */ | |
6955 | if (sd->flags & (SD_WAKE_IDLE | | |
6956 | SD_WAKE_AFFINE | | |
6957 | SD_WAKE_BALANCE)) | |
6958 | return 0; | |
6959 | ||
6960 | return 1; | |
6961 | } | |
6962 | ||
48f24c4d IM |
6963 | static int |
6964 | sd_parent_degenerate(struct sched_domain *sd, struct sched_domain *parent) | |
245af2c7 SS |
6965 | { |
6966 | unsigned long cflags = sd->flags, pflags = parent->flags; | |
6967 | ||
6968 | if (sd_degenerate(parent)) | |
6969 | return 1; | |
6970 | ||
758b2cdc | 6971 | if (!cpumask_equal(sched_domain_span(sd), sched_domain_span(parent))) |
245af2c7 SS |
6972 | return 0; |
6973 | ||
6974 | /* Does parent contain flags not in child? */ | |
6975 | /* WAKE_BALANCE is a subset of WAKE_AFFINE */ | |
6976 | if (cflags & SD_WAKE_AFFINE) | |
6977 | pflags &= ~SD_WAKE_BALANCE; | |
6978 | /* Flags needing groups don't count if only 1 group in parent */ | |
6979 | if (parent->groups == parent->groups->next) { | |
6980 | pflags &= ~(SD_LOAD_BALANCE | | |
6981 | SD_BALANCE_NEWIDLE | | |
6982 | SD_BALANCE_FORK | | |
89c4710e SS |
6983 | SD_BALANCE_EXEC | |
6984 | SD_SHARE_CPUPOWER | | |
6985 | SD_SHARE_PKG_RESOURCES); | |
5436499e KC |
6986 | if (nr_node_ids == 1) |
6987 | pflags &= ~SD_SERIALIZE; | |
245af2c7 SS |
6988 | } |
6989 | if (~cflags & pflags) | |
6990 | return 0; | |
6991 | ||
6992 | return 1; | |
6993 | } | |
6994 | ||
c6c4927b RR |
6995 | static void free_rootdomain(struct root_domain *rd) |
6996 | { | |
68e74568 RR |
6997 | cpupri_cleanup(&rd->cpupri); |
6998 | ||
c6c4927b RR |
6999 | free_cpumask_var(rd->rto_mask); |
7000 | free_cpumask_var(rd->online); | |
7001 | free_cpumask_var(rd->span); | |
7002 | kfree(rd); | |
7003 | } | |
7004 | ||
57d885fe GH |
7005 | static void rq_attach_root(struct rq *rq, struct root_domain *rd) |
7006 | { | |
7007 | unsigned long flags; | |
57d885fe GH |
7008 | |
7009 | spin_lock_irqsave(&rq->lock, flags); | |
7010 | ||
7011 | if (rq->rd) { | |
7012 | struct root_domain *old_rd = rq->rd; | |
7013 | ||
c6c4927b | 7014 | if (cpumask_test_cpu(rq->cpu, old_rd->online)) |
1f11eb6a | 7015 | set_rq_offline(rq); |
57d885fe | 7016 | |
c6c4927b | 7017 | cpumask_clear_cpu(rq->cpu, old_rd->span); |
dc938520 | 7018 | |
57d885fe | 7019 | if (atomic_dec_and_test(&old_rd->refcount)) |
c6c4927b | 7020 | free_rootdomain(old_rd); |
57d885fe GH |
7021 | } |
7022 | ||
7023 | atomic_inc(&rd->refcount); | |
7024 | rq->rd = rd; | |
7025 | ||
c6c4927b RR |
7026 | cpumask_set_cpu(rq->cpu, rd->span); |
7027 | if (cpumask_test_cpu(rq->cpu, cpu_online_mask)) | |
1f11eb6a | 7028 | set_rq_online(rq); |
57d885fe GH |
7029 | |
7030 | spin_unlock_irqrestore(&rq->lock, flags); | |
7031 | } | |
7032 | ||
db2f59c8 | 7033 | static int __init_refok init_rootdomain(struct root_domain *rd, bool bootmem) |
57d885fe GH |
7034 | { |
7035 | memset(rd, 0, sizeof(*rd)); | |
7036 | ||
c6c4927b RR |
7037 | if (bootmem) { |
7038 | alloc_bootmem_cpumask_var(&def_root_domain.span); | |
7039 | alloc_bootmem_cpumask_var(&def_root_domain.online); | |
7040 | alloc_bootmem_cpumask_var(&def_root_domain.rto_mask); | |
68e74568 | 7041 | cpupri_init(&rd->cpupri, true); |
c6c4927b RR |
7042 | return 0; |
7043 | } | |
7044 | ||
7045 | if (!alloc_cpumask_var(&rd->span, GFP_KERNEL)) | |
0c910d28 | 7046 | goto out; |
c6c4927b RR |
7047 | if (!alloc_cpumask_var(&rd->online, GFP_KERNEL)) |
7048 | goto free_span; | |
7049 | if (!alloc_cpumask_var(&rd->rto_mask, GFP_KERNEL)) | |
7050 | goto free_online; | |
6e0534f2 | 7051 | |
68e74568 RR |
7052 | if (cpupri_init(&rd->cpupri, false) != 0) |
7053 | goto free_rto_mask; | |
c6c4927b | 7054 | return 0; |
6e0534f2 | 7055 | |
68e74568 RR |
7056 | free_rto_mask: |
7057 | free_cpumask_var(rd->rto_mask); | |
c6c4927b RR |
7058 | free_online: |
7059 | free_cpumask_var(rd->online); | |
7060 | free_span: | |
7061 | free_cpumask_var(rd->span); | |
0c910d28 | 7062 | out: |
c6c4927b | 7063 | return -ENOMEM; |
57d885fe GH |
7064 | } |
7065 | ||
7066 | static void init_defrootdomain(void) | |
7067 | { | |
c6c4927b RR |
7068 | init_rootdomain(&def_root_domain, true); |
7069 | ||
57d885fe GH |
7070 | atomic_set(&def_root_domain.refcount, 1); |
7071 | } | |
7072 | ||
dc938520 | 7073 | static struct root_domain *alloc_rootdomain(void) |
57d885fe GH |
7074 | { |
7075 | struct root_domain *rd; | |
7076 | ||
7077 | rd = kmalloc(sizeof(*rd), GFP_KERNEL); | |
7078 | if (!rd) | |
7079 | return NULL; | |
7080 | ||
c6c4927b RR |
7081 | if (init_rootdomain(rd, false) != 0) { |
7082 | kfree(rd); | |
7083 | return NULL; | |
7084 | } | |
57d885fe GH |
7085 | |
7086 | return rd; | |
7087 | } | |
7088 | ||
1da177e4 | 7089 | /* |
0eab9146 | 7090 | * Attach the domain 'sd' to 'cpu' as its base domain. Callers must |
1da177e4 LT |
7091 | * hold the hotplug lock. |
7092 | */ | |
0eab9146 IM |
7093 | static void |
7094 | cpu_attach_domain(struct sched_domain *sd, struct root_domain *rd, int cpu) | |
1da177e4 | 7095 | { |
70b97a7f | 7096 | struct rq *rq = cpu_rq(cpu); |
245af2c7 SS |
7097 | struct sched_domain *tmp; |
7098 | ||
7099 | /* Remove the sched domains which do not contribute to scheduling. */ | |
f29c9b1c | 7100 | for (tmp = sd; tmp; ) { |
245af2c7 SS |
7101 | struct sched_domain *parent = tmp->parent; |
7102 | if (!parent) | |
7103 | break; | |
f29c9b1c | 7104 | |
1a848870 | 7105 | if (sd_parent_degenerate(tmp, parent)) { |
245af2c7 | 7106 | tmp->parent = parent->parent; |
1a848870 SS |
7107 | if (parent->parent) |
7108 | parent->parent->child = tmp; | |
f29c9b1c LZ |
7109 | } else |
7110 | tmp = tmp->parent; | |
245af2c7 SS |
7111 | } |
7112 | ||
1a848870 | 7113 | if (sd && sd_degenerate(sd)) { |
245af2c7 | 7114 | sd = sd->parent; |
1a848870 SS |
7115 | if (sd) |
7116 | sd->child = NULL; | |
7117 | } | |
1da177e4 LT |
7118 | |
7119 | sched_domain_debug(sd, cpu); | |
7120 | ||
57d885fe | 7121 | rq_attach_root(rq, rd); |
674311d5 | 7122 | rcu_assign_pointer(rq->sd, sd); |
1da177e4 LT |
7123 | } |
7124 | ||
7125 | /* cpus with isolated domains */ | |
dcc30a35 | 7126 | static cpumask_var_t cpu_isolated_map; |
1da177e4 LT |
7127 | |
7128 | /* Setup the mask of cpus configured for isolated domains */ | |
7129 | static int __init isolated_cpu_setup(char *str) | |
7130 | { | |
968ea6d8 | 7131 | cpulist_parse(str, cpu_isolated_map); |
1da177e4 LT |
7132 | return 1; |
7133 | } | |
7134 | ||
8927f494 | 7135 | __setup("isolcpus=", isolated_cpu_setup); |
1da177e4 LT |
7136 | |
7137 | /* | |
6711cab4 SS |
7138 | * init_sched_build_groups takes the cpumask we wish to span, and a pointer |
7139 | * to a function which identifies what group(along with sched group) a CPU | |
96f874e2 RR |
7140 | * belongs to. The return value of group_fn must be a >= 0 and < nr_cpu_ids |
7141 | * (due to the fact that we keep track of groups covered with a struct cpumask). | |
1da177e4 LT |
7142 | * |
7143 | * init_sched_build_groups will build a circular linked list of the groups | |
7144 | * covered by the given span, and will set each group's ->cpumask correctly, | |
7145 | * and ->cpu_power to 0. | |
7146 | */ | |
a616058b | 7147 | static void |
96f874e2 RR |
7148 | init_sched_build_groups(const struct cpumask *span, |
7149 | const struct cpumask *cpu_map, | |
7150 | int (*group_fn)(int cpu, const struct cpumask *cpu_map, | |
7c16ec58 | 7151 | struct sched_group **sg, |
96f874e2 RR |
7152 | struct cpumask *tmpmask), |
7153 | struct cpumask *covered, struct cpumask *tmpmask) | |
1da177e4 LT |
7154 | { |
7155 | struct sched_group *first = NULL, *last = NULL; | |
1da177e4 LT |
7156 | int i; |
7157 | ||
96f874e2 | 7158 | cpumask_clear(covered); |
7c16ec58 | 7159 | |
abcd083a | 7160 | for_each_cpu(i, span) { |
6711cab4 | 7161 | struct sched_group *sg; |
7c16ec58 | 7162 | int group = group_fn(i, cpu_map, &sg, tmpmask); |
1da177e4 LT |
7163 | int j; |
7164 | ||
758b2cdc | 7165 | if (cpumask_test_cpu(i, covered)) |
1da177e4 LT |
7166 | continue; |
7167 | ||
758b2cdc | 7168 | cpumask_clear(sched_group_cpus(sg)); |
5517d86b | 7169 | sg->__cpu_power = 0; |
1da177e4 | 7170 | |
abcd083a | 7171 | for_each_cpu(j, span) { |
7c16ec58 | 7172 | if (group_fn(j, cpu_map, NULL, tmpmask) != group) |
1da177e4 LT |
7173 | continue; |
7174 | ||
96f874e2 | 7175 | cpumask_set_cpu(j, covered); |
758b2cdc | 7176 | cpumask_set_cpu(j, sched_group_cpus(sg)); |
1da177e4 LT |
7177 | } |
7178 | if (!first) | |
7179 | first = sg; | |
7180 | if (last) | |
7181 | last->next = sg; | |
7182 | last = sg; | |
7183 | } | |
7184 | last->next = first; | |
7185 | } | |
7186 | ||
9c1cfda2 | 7187 | #define SD_NODES_PER_DOMAIN 16 |
1da177e4 | 7188 | |
9c1cfda2 | 7189 | #ifdef CONFIG_NUMA |
198e2f18 | 7190 | |
9c1cfda2 JH |
7191 | /** |
7192 | * find_next_best_node - find the next node to include in a sched_domain | |
7193 | * @node: node whose sched_domain we're building | |
7194 | * @used_nodes: nodes already in the sched_domain | |
7195 | * | |
41a2d6cf | 7196 | * Find the next node to include in a given scheduling domain. Simply |
9c1cfda2 JH |
7197 | * finds the closest node not already in the @used_nodes map. |
7198 | * | |
7199 | * Should use nodemask_t. | |
7200 | */ | |
c5f59f08 | 7201 | static int find_next_best_node(int node, nodemask_t *used_nodes) |
9c1cfda2 JH |
7202 | { |
7203 | int i, n, val, min_val, best_node = 0; | |
7204 | ||
7205 | min_val = INT_MAX; | |
7206 | ||
076ac2af | 7207 | for (i = 0; i < nr_node_ids; i++) { |
9c1cfda2 | 7208 | /* Start at @node */ |
076ac2af | 7209 | n = (node + i) % nr_node_ids; |
9c1cfda2 JH |
7210 | |
7211 | if (!nr_cpus_node(n)) | |
7212 | continue; | |
7213 | ||
7214 | /* Skip already used nodes */ | |
c5f59f08 | 7215 | if (node_isset(n, *used_nodes)) |
9c1cfda2 JH |
7216 | continue; |
7217 | ||
7218 | /* Simple min distance search */ | |
7219 | val = node_distance(node, n); | |
7220 | ||
7221 | if (val < min_val) { | |
7222 | min_val = val; | |
7223 | best_node = n; | |
7224 | } | |
7225 | } | |
7226 | ||
c5f59f08 | 7227 | node_set(best_node, *used_nodes); |
9c1cfda2 JH |
7228 | return best_node; |
7229 | } | |
7230 | ||
7231 | /** | |
7232 | * sched_domain_node_span - get a cpumask for a node's sched_domain | |
7233 | * @node: node whose cpumask we're constructing | |
73486722 | 7234 | * @span: resulting cpumask |
9c1cfda2 | 7235 | * |
41a2d6cf | 7236 | * Given a node, construct a good cpumask for its sched_domain to span. It |
9c1cfda2 JH |
7237 | * should be one that prevents unnecessary balancing, but also spreads tasks |
7238 | * out optimally. | |
7239 | */ | |
96f874e2 | 7240 | static void sched_domain_node_span(int node, struct cpumask *span) |
9c1cfda2 | 7241 | { |
c5f59f08 | 7242 | nodemask_t used_nodes; |
48f24c4d | 7243 | int i; |
9c1cfda2 | 7244 | |
6ca09dfc | 7245 | cpumask_clear(span); |
c5f59f08 | 7246 | nodes_clear(used_nodes); |
9c1cfda2 | 7247 | |
6ca09dfc | 7248 | cpumask_or(span, span, cpumask_of_node(node)); |
c5f59f08 | 7249 | node_set(node, used_nodes); |
9c1cfda2 JH |
7250 | |
7251 | for (i = 1; i < SD_NODES_PER_DOMAIN; i++) { | |
c5f59f08 | 7252 | int next_node = find_next_best_node(node, &used_nodes); |
48f24c4d | 7253 | |
6ca09dfc | 7254 | cpumask_or(span, span, cpumask_of_node(next_node)); |
9c1cfda2 | 7255 | } |
9c1cfda2 | 7256 | } |
6d6bc0ad | 7257 | #endif /* CONFIG_NUMA */ |
9c1cfda2 | 7258 | |
5c45bf27 | 7259 | int sched_smt_power_savings = 0, sched_mc_power_savings = 0; |
48f24c4d | 7260 | |
6c99e9ad RR |
7261 | /* |
7262 | * The cpus mask in sched_group and sched_domain hangs off the end. | |
7263 | * FIXME: use cpumask_var_t or dynamic percpu alloc to avoid wasting space | |
7264 | * for nr_cpu_ids < CONFIG_NR_CPUS. | |
7265 | */ | |
7266 | struct static_sched_group { | |
7267 | struct sched_group sg; | |
7268 | DECLARE_BITMAP(cpus, CONFIG_NR_CPUS); | |
7269 | }; | |
7270 | ||
7271 | struct static_sched_domain { | |
7272 | struct sched_domain sd; | |
7273 | DECLARE_BITMAP(span, CONFIG_NR_CPUS); | |
7274 | }; | |
7275 | ||
9c1cfda2 | 7276 | /* |
48f24c4d | 7277 | * SMT sched-domains: |
9c1cfda2 | 7278 | */ |
1da177e4 | 7279 | #ifdef CONFIG_SCHED_SMT |
6c99e9ad RR |
7280 | static DEFINE_PER_CPU(struct static_sched_domain, cpu_domains); |
7281 | static DEFINE_PER_CPU(struct static_sched_group, sched_group_cpus); | |
48f24c4d | 7282 | |
41a2d6cf | 7283 | static int |
96f874e2 RR |
7284 | cpu_to_cpu_group(int cpu, const struct cpumask *cpu_map, |
7285 | struct sched_group **sg, struct cpumask *unused) | |
1da177e4 | 7286 | { |
6711cab4 | 7287 | if (sg) |
6c99e9ad | 7288 | *sg = &per_cpu(sched_group_cpus, cpu).sg; |
1da177e4 LT |
7289 | return cpu; |
7290 | } | |
6d6bc0ad | 7291 | #endif /* CONFIG_SCHED_SMT */ |
1da177e4 | 7292 | |
48f24c4d IM |
7293 | /* |
7294 | * multi-core sched-domains: | |
7295 | */ | |
1e9f28fa | 7296 | #ifdef CONFIG_SCHED_MC |
6c99e9ad RR |
7297 | static DEFINE_PER_CPU(struct static_sched_domain, core_domains); |
7298 | static DEFINE_PER_CPU(struct static_sched_group, sched_group_core); | |
6d6bc0ad | 7299 | #endif /* CONFIG_SCHED_MC */ |
1e9f28fa SS |
7300 | |
7301 | #if defined(CONFIG_SCHED_MC) && defined(CONFIG_SCHED_SMT) | |
41a2d6cf | 7302 | static int |
96f874e2 RR |
7303 | cpu_to_core_group(int cpu, const struct cpumask *cpu_map, |
7304 | struct sched_group **sg, struct cpumask *mask) | |
1e9f28fa | 7305 | { |
6711cab4 | 7306 | int group; |
7c16ec58 | 7307 | |
96f874e2 RR |
7308 | cpumask_and(mask, &per_cpu(cpu_sibling_map, cpu), cpu_map); |
7309 | group = cpumask_first(mask); | |
6711cab4 | 7310 | if (sg) |
6c99e9ad | 7311 | *sg = &per_cpu(sched_group_core, group).sg; |
6711cab4 | 7312 | return group; |
1e9f28fa SS |
7313 | } |
7314 | #elif defined(CONFIG_SCHED_MC) | |
41a2d6cf | 7315 | static int |
96f874e2 RR |
7316 | cpu_to_core_group(int cpu, const struct cpumask *cpu_map, |
7317 | struct sched_group **sg, struct cpumask *unused) | |
1e9f28fa | 7318 | { |
6711cab4 | 7319 | if (sg) |
6c99e9ad | 7320 | *sg = &per_cpu(sched_group_core, cpu).sg; |
1e9f28fa SS |
7321 | return cpu; |
7322 | } | |
7323 | #endif | |
7324 | ||
6c99e9ad RR |
7325 | static DEFINE_PER_CPU(struct static_sched_domain, phys_domains); |
7326 | static DEFINE_PER_CPU(struct static_sched_group, sched_group_phys); | |
48f24c4d | 7327 | |
41a2d6cf | 7328 | static int |
96f874e2 RR |
7329 | cpu_to_phys_group(int cpu, const struct cpumask *cpu_map, |
7330 | struct sched_group **sg, struct cpumask *mask) | |
1da177e4 | 7331 | { |
6711cab4 | 7332 | int group; |
48f24c4d | 7333 | #ifdef CONFIG_SCHED_MC |
6ca09dfc | 7334 | cpumask_and(mask, cpu_coregroup_mask(cpu), cpu_map); |
96f874e2 | 7335 | group = cpumask_first(mask); |
1e9f28fa | 7336 | #elif defined(CONFIG_SCHED_SMT) |
96f874e2 RR |
7337 | cpumask_and(mask, &per_cpu(cpu_sibling_map, cpu), cpu_map); |
7338 | group = cpumask_first(mask); | |
1da177e4 | 7339 | #else |
6711cab4 | 7340 | group = cpu; |
1da177e4 | 7341 | #endif |
6711cab4 | 7342 | if (sg) |
6c99e9ad | 7343 | *sg = &per_cpu(sched_group_phys, group).sg; |
6711cab4 | 7344 | return group; |
1da177e4 LT |
7345 | } |
7346 | ||
7347 | #ifdef CONFIG_NUMA | |
1da177e4 | 7348 | /* |
9c1cfda2 JH |
7349 | * The init_sched_build_groups can't handle what we want to do with node |
7350 | * groups, so roll our own. Now each node has its own list of groups which | |
7351 | * gets dynamically allocated. | |
1da177e4 | 7352 | */ |
62ea9ceb | 7353 | static DEFINE_PER_CPU(struct static_sched_domain, node_domains); |
434d53b0 | 7354 | static struct sched_group ***sched_group_nodes_bycpu; |
1da177e4 | 7355 | |
62ea9ceb | 7356 | static DEFINE_PER_CPU(struct static_sched_domain, allnodes_domains); |
6c99e9ad | 7357 | static DEFINE_PER_CPU(struct static_sched_group, sched_group_allnodes); |
9c1cfda2 | 7358 | |
96f874e2 RR |
7359 | static int cpu_to_allnodes_group(int cpu, const struct cpumask *cpu_map, |
7360 | struct sched_group **sg, | |
7361 | struct cpumask *nodemask) | |
9c1cfda2 | 7362 | { |
6711cab4 SS |
7363 | int group; |
7364 | ||
6ca09dfc | 7365 | cpumask_and(nodemask, cpumask_of_node(cpu_to_node(cpu)), cpu_map); |
96f874e2 | 7366 | group = cpumask_first(nodemask); |
6711cab4 SS |
7367 | |
7368 | if (sg) | |
6c99e9ad | 7369 | *sg = &per_cpu(sched_group_allnodes, group).sg; |
6711cab4 | 7370 | return group; |
1da177e4 | 7371 | } |
6711cab4 | 7372 | |
08069033 SS |
7373 | static void init_numa_sched_groups_power(struct sched_group *group_head) |
7374 | { | |
7375 | struct sched_group *sg = group_head; | |
7376 | int j; | |
7377 | ||
7378 | if (!sg) | |
7379 | return; | |
3a5c359a | 7380 | do { |
758b2cdc | 7381 | for_each_cpu(j, sched_group_cpus(sg)) { |
3a5c359a | 7382 | struct sched_domain *sd; |
08069033 | 7383 | |
6c99e9ad | 7384 | sd = &per_cpu(phys_domains, j).sd; |
758b2cdc | 7385 | if (j != cpumask_first(sched_group_cpus(sd->groups))) { |
3a5c359a AK |
7386 | /* |
7387 | * Only add "power" once for each | |
7388 | * physical package. | |
7389 | */ | |
7390 | continue; | |
7391 | } | |
08069033 | 7392 | |
3a5c359a AK |
7393 | sg_inc_cpu_power(sg, sd->groups->__cpu_power); |
7394 | } | |
7395 | sg = sg->next; | |
7396 | } while (sg != group_head); | |
08069033 | 7397 | } |
6d6bc0ad | 7398 | #endif /* CONFIG_NUMA */ |
1da177e4 | 7399 | |
a616058b | 7400 | #ifdef CONFIG_NUMA |
51888ca2 | 7401 | /* Free memory allocated for various sched_group structures */ |
96f874e2 RR |
7402 | static void free_sched_groups(const struct cpumask *cpu_map, |
7403 | struct cpumask *nodemask) | |
51888ca2 | 7404 | { |
a616058b | 7405 | int cpu, i; |
51888ca2 | 7406 | |
abcd083a | 7407 | for_each_cpu(cpu, cpu_map) { |
51888ca2 SV |
7408 | struct sched_group **sched_group_nodes |
7409 | = sched_group_nodes_bycpu[cpu]; | |
7410 | ||
51888ca2 SV |
7411 | if (!sched_group_nodes) |
7412 | continue; | |
7413 | ||
076ac2af | 7414 | for (i = 0; i < nr_node_ids; i++) { |
51888ca2 SV |
7415 | struct sched_group *oldsg, *sg = sched_group_nodes[i]; |
7416 | ||
6ca09dfc | 7417 | cpumask_and(nodemask, cpumask_of_node(i), cpu_map); |
96f874e2 | 7418 | if (cpumask_empty(nodemask)) |
51888ca2 SV |
7419 | continue; |
7420 | ||
7421 | if (sg == NULL) | |
7422 | continue; | |
7423 | sg = sg->next; | |
7424 | next_sg: | |
7425 | oldsg = sg; | |
7426 | sg = sg->next; | |
7427 | kfree(oldsg); | |
7428 | if (oldsg != sched_group_nodes[i]) | |
7429 | goto next_sg; | |
7430 | } | |
7431 | kfree(sched_group_nodes); | |
7432 | sched_group_nodes_bycpu[cpu] = NULL; | |
7433 | } | |
51888ca2 | 7434 | } |
6d6bc0ad | 7435 | #else /* !CONFIG_NUMA */ |
96f874e2 RR |
7436 | static void free_sched_groups(const struct cpumask *cpu_map, |
7437 | struct cpumask *nodemask) | |
a616058b SS |
7438 | { |
7439 | } | |
6d6bc0ad | 7440 | #endif /* CONFIG_NUMA */ |
51888ca2 | 7441 | |
89c4710e SS |
7442 | /* |
7443 | * Initialize sched groups cpu_power. | |
7444 | * | |
7445 | * cpu_power indicates the capacity of sched group, which is used while | |
7446 | * distributing the load between different sched groups in a sched domain. | |
7447 | * Typically cpu_power for all the groups in a sched domain will be same unless | |
7448 | * there are asymmetries in the topology. If there are asymmetries, group | |
7449 | * having more cpu_power will pickup more load compared to the group having | |
7450 | * less cpu_power. | |
7451 | * | |
7452 | * cpu_power will be a multiple of SCHED_LOAD_SCALE. This multiple represents | |
7453 | * the maximum number of tasks a group can handle in the presence of other idle | |
7454 | * or lightly loaded groups in the same sched domain. | |
7455 | */ | |
7456 | static void init_sched_groups_power(int cpu, struct sched_domain *sd) | |
7457 | { | |
7458 | struct sched_domain *child; | |
7459 | struct sched_group *group; | |
7460 | ||
7461 | WARN_ON(!sd || !sd->groups); | |
7462 | ||
758b2cdc | 7463 | if (cpu != cpumask_first(sched_group_cpus(sd->groups))) |
89c4710e SS |
7464 | return; |
7465 | ||
7466 | child = sd->child; | |
7467 | ||
5517d86b ED |
7468 | sd->groups->__cpu_power = 0; |
7469 | ||
89c4710e SS |
7470 | /* |
7471 | * For perf policy, if the groups in child domain share resources | |
7472 | * (for example cores sharing some portions of the cache hierarchy | |
7473 | * or SMT), then set this domain groups cpu_power such that each group | |
7474 | * can handle only one task, when there are other idle groups in the | |
7475 | * same sched domain. | |
7476 | */ | |
7477 | if (!child || (!(sd->flags & SD_POWERSAVINGS_BALANCE) && | |
7478 | (child->flags & | |
7479 | (SD_SHARE_CPUPOWER | SD_SHARE_PKG_RESOURCES)))) { | |
5517d86b | 7480 | sg_inc_cpu_power(sd->groups, SCHED_LOAD_SCALE); |
89c4710e SS |
7481 | return; |
7482 | } | |
7483 | ||
89c4710e SS |
7484 | /* |
7485 | * add cpu_power of each child group to this groups cpu_power | |
7486 | */ | |
7487 | group = child->groups; | |
7488 | do { | |
5517d86b | 7489 | sg_inc_cpu_power(sd->groups, group->__cpu_power); |
89c4710e SS |
7490 | group = group->next; |
7491 | } while (group != child->groups); | |
7492 | } | |
7493 | ||
7c16ec58 MT |
7494 | /* |
7495 | * Initializers for schedule domains | |
7496 | * Non-inlined to reduce accumulated stack pressure in build_sched_domains() | |
7497 | */ | |
7498 | ||
a5d8c348 IM |
7499 | #ifdef CONFIG_SCHED_DEBUG |
7500 | # define SD_INIT_NAME(sd, type) sd->name = #type | |
7501 | #else | |
7502 | # define SD_INIT_NAME(sd, type) do { } while (0) | |
7503 | #endif | |
7504 | ||
7c16ec58 | 7505 | #define SD_INIT(sd, type) sd_init_##type(sd) |
a5d8c348 | 7506 | |
7c16ec58 MT |
7507 | #define SD_INIT_FUNC(type) \ |
7508 | static noinline void sd_init_##type(struct sched_domain *sd) \ | |
7509 | { \ | |
7510 | memset(sd, 0, sizeof(*sd)); \ | |
7511 | *sd = SD_##type##_INIT; \ | |
1d3504fc | 7512 | sd->level = SD_LV_##type; \ |
a5d8c348 | 7513 | SD_INIT_NAME(sd, type); \ |
7c16ec58 MT |
7514 | } |
7515 | ||
7516 | SD_INIT_FUNC(CPU) | |
7517 | #ifdef CONFIG_NUMA | |
7518 | SD_INIT_FUNC(ALLNODES) | |
7519 | SD_INIT_FUNC(NODE) | |
7520 | #endif | |
7521 | #ifdef CONFIG_SCHED_SMT | |
7522 | SD_INIT_FUNC(SIBLING) | |
7523 | #endif | |
7524 | #ifdef CONFIG_SCHED_MC | |
7525 | SD_INIT_FUNC(MC) | |
7526 | #endif | |
7527 | ||
1d3504fc HS |
7528 | static int default_relax_domain_level = -1; |
7529 | ||
7530 | static int __init setup_relax_domain_level(char *str) | |
7531 | { | |
30e0e178 LZ |
7532 | unsigned long val; |
7533 | ||
7534 | val = simple_strtoul(str, NULL, 0); | |
7535 | if (val < SD_LV_MAX) | |
7536 | default_relax_domain_level = val; | |
7537 | ||
1d3504fc HS |
7538 | return 1; |
7539 | } | |
7540 | __setup("relax_domain_level=", setup_relax_domain_level); | |
7541 | ||
7542 | static void set_domain_attribute(struct sched_domain *sd, | |
7543 | struct sched_domain_attr *attr) | |
7544 | { | |
7545 | int request; | |
7546 | ||
7547 | if (!attr || attr->relax_domain_level < 0) { | |
7548 | if (default_relax_domain_level < 0) | |
7549 | return; | |
7550 | else | |
7551 | request = default_relax_domain_level; | |
7552 | } else | |
7553 | request = attr->relax_domain_level; | |
7554 | if (request < sd->level) { | |
7555 | /* turn off idle balance on this domain */ | |
7556 | sd->flags &= ~(SD_WAKE_IDLE|SD_BALANCE_NEWIDLE); | |
7557 | } else { | |
7558 | /* turn on idle balance on this domain */ | |
7559 | sd->flags |= (SD_WAKE_IDLE_FAR|SD_BALANCE_NEWIDLE); | |
7560 | } | |
7561 | } | |
7562 | ||
1da177e4 | 7563 | /* |
1a20ff27 DG |
7564 | * Build sched domains for a given set of cpus and attach the sched domains |
7565 | * to the individual cpus | |
1da177e4 | 7566 | */ |
96f874e2 | 7567 | static int __build_sched_domains(const struct cpumask *cpu_map, |
1d3504fc | 7568 | struct sched_domain_attr *attr) |
1da177e4 | 7569 | { |
3404c8d9 | 7570 | int i, err = -ENOMEM; |
57d885fe | 7571 | struct root_domain *rd; |
3404c8d9 RR |
7572 | cpumask_var_t nodemask, this_sibling_map, this_core_map, send_covered, |
7573 | tmpmask; | |
d1b55138 | 7574 | #ifdef CONFIG_NUMA |
3404c8d9 | 7575 | cpumask_var_t domainspan, covered, notcovered; |
d1b55138 | 7576 | struct sched_group **sched_group_nodes = NULL; |
6711cab4 | 7577 | int sd_allnodes = 0; |
d1b55138 | 7578 | |
3404c8d9 RR |
7579 | if (!alloc_cpumask_var(&domainspan, GFP_KERNEL)) |
7580 | goto out; | |
7581 | if (!alloc_cpumask_var(&covered, GFP_KERNEL)) | |
7582 | goto free_domainspan; | |
7583 | if (!alloc_cpumask_var(¬covered, GFP_KERNEL)) | |
7584 | goto free_covered; | |
7585 | #endif | |
7586 | ||
7587 | if (!alloc_cpumask_var(&nodemask, GFP_KERNEL)) | |
7588 | goto free_notcovered; | |
7589 | if (!alloc_cpumask_var(&this_sibling_map, GFP_KERNEL)) | |
7590 | goto free_nodemask; | |
7591 | if (!alloc_cpumask_var(&this_core_map, GFP_KERNEL)) | |
7592 | goto free_this_sibling_map; | |
7593 | if (!alloc_cpumask_var(&send_covered, GFP_KERNEL)) | |
7594 | goto free_this_core_map; | |
7595 | if (!alloc_cpumask_var(&tmpmask, GFP_KERNEL)) | |
7596 | goto free_send_covered; | |
7597 | ||
7598 | #ifdef CONFIG_NUMA | |
d1b55138 JH |
7599 | /* |
7600 | * Allocate the per-node list of sched groups | |
7601 | */ | |
076ac2af | 7602 | sched_group_nodes = kcalloc(nr_node_ids, sizeof(struct sched_group *), |
41a2d6cf | 7603 | GFP_KERNEL); |
d1b55138 JH |
7604 | if (!sched_group_nodes) { |
7605 | printk(KERN_WARNING "Can not alloc sched group node list\n"); | |
3404c8d9 | 7606 | goto free_tmpmask; |
d1b55138 | 7607 | } |
d1b55138 | 7608 | #endif |
1da177e4 | 7609 | |
dc938520 | 7610 | rd = alloc_rootdomain(); |
57d885fe GH |
7611 | if (!rd) { |
7612 | printk(KERN_WARNING "Cannot alloc root domain\n"); | |
3404c8d9 | 7613 | goto free_sched_groups; |
7c16ec58 | 7614 | } |
6d21cd62 | 7615 | |
7c16ec58 | 7616 | #ifdef CONFIG_NUMA |
96f874e2 | 7617 | sched_group_nodes_bycpu[cpumask_first(cpu_map)] = sched_group_nodes; |
7c16ec58 MT |
7618 | #endif |
7619 | ||
1da177e4 | 7620 | /* |
1a20ff27 | 7621 | * Set up domains for cpus specified by the cpu_map. |
1da177e4 | 7622 | */ |
abcd083a | 7623 | for_each_cpu(i, cpu_map) { |
1da177e4 | 7624 | struct sched_domain *sd = NULL, *p; |
1da177e4 | 7625 | |
6ca09dfc | 7626 | cpumask_and(nodemask, cpumask_of_node(cpu_to_node(i)), cpu_map); |
1da177e4 LT |
7627 | |
7628 | #ifdef CONFIG_NUMA | |
96f874e2 RR |
7629 | if (cpumask_weight(cpu_map) > |
7630 | SD_NODES_PER_DOMAIN*cpumask_weight(nodemask)) { | |
62ea9ceb | 7631 | sd = &per_cpu(allnodes_domains, i).sd; |
7c16ec58 | 7632 | SD_INIT(sd, ALLNODES); |
1d3504fc | 7633 | set_domain_attribute(sd, attr); |
758b2cdc | 7634 | cpumask_copy(sched_domain_span(sd), cpu_map); |
7c16ec58 | 7635 | cpu_to_allnodes_group(i, cpu_map, &sd->groups, tmpmask); |
9c1cfda2 | 7636 | p = sd; |
6711cab4 | 7637 | sd_allnodes = 1; |
9c1cfda2 JH |
7638 | } else |
7639 | p = NULL; | |
7640 | ||
62ea9ceb | 7641 | sd = &per_cpu(node_domains, i).sd; |
7c16ec58 | 7642 | SD_INIT(sd, NODE); |
1d3504fc | 7643 | set_domain_attribute(sd, attr); |
758b2cdc | 7644 | sched_domain_node_span(cpu_to_node(i), sched_domain_span(sd)); |
9c1cfda2 | 7645 | sd->parent = p; |
1a848870 SS |
7646 | if (p) |
7647 | p->child = sd; | |
758b2cdc RR |
7648 | cpumask_and(sched_domain_span(sd), |
7649 | sched_domain_span(sd), cpu_map); | |
1da177e4 LT |
7650 | #endif |
7651 | ||
7652 | p = sd; | |
6c99e9ad | 7653 | sd = &per_cpu(phys_domains, i).sd; |
7c16ec58 | 7654 | SD_INIT(sd, CPU); |
1d3504fc | 7655 | set_domain_attribute(sd, attr); |
758b2cdc | 7656 | cpumask_copy(sched_domain_span(sd), nodemask); |
1da177e4 | 7657 | sd->parent = p; |
1a848870 SS |
7658 | if (p) |
7659 | p->child = sd; | |
7c16ec58 | 7660 | cpu_to_phys_group(i, cpu_map, &sd->groups, tmpmask); |
1da177e4 | 7661 | |
1e9f28fa SS |
7662 | #ifdef CONFIG_SCHED_MC |
7663 | p = sd; | |
6c99e9ad | 7664 | sd = &per_cpu(core_domains, i).sd; |
7c16ec58 | 7665 | SD_INIT(sd, MC); |
1d3504fc | 7666 | set_domain_attribute(sd, attr); |
6ca09dfc MT |
7667 | cpumask_and(sched_domain_span(sd), cpu_map, |
7668 | cpu_coregroup_mask(i)); | |
1e9f28fa | 7669 | sd->parent = p; |
1a848870 | 7670 | p->child = sd; |
7c16ec58 | 7671 | cpu_to_core_group(i, cpu_map, &sd->groups, tmpmask); |
1e9f28fa SS |
7672 | #endif |
7673 | ||
1da177e4 LT |
7674 | #ifdef CONFIG_SCHED_SMT |
7675 | p = sd; | |
6c99e9ad | 7676 | sd = &per_cpu(cpu_domains, i).sd; |
7c16ec58 | 7677 | SD_INIT(sd, SIBLING); |
1d3504fc | 7678 | set_domain_attribute(sd, attr); |
758b2cdc RR |
7679 | cpumask_and(sched_domain_span(sd), |
7680 | &per_cpu(cpu_sibling_map, i), cpu_map); | |
1da177e4 | 7681 | sd->parent = p; |
1a848870 | 7682 | p->child = sd; |
7c16ec58 | 7683 | cpu_to_cpu_group(i, cpu_map, &sd->groups, tmpmask); |
1da177e4 LT |
7684 | #endif |
7685 | } | |
7686 | ||
7687 | #ifdef CONFIG_SCHED_SMT | |
7688 | /* Set up CPU (sibling) groups */ | |
abcd083a | 7689 | for_each_cpu(i, cpu_map) { |
96f874e2 RR |
7690 | cpumask_and(this_sibling_map, |
7691 | &per_cpu(cpu_sibling_map, i), cpu_map); | |
7692 | if (i != cpumask_first(this_sibling_map)) | |
1da177e4 LT |
7693 | continue; |
7694 | ||
dd41f596 | 7695 | init_sched_build_groups(this_sibling_map, cpu_map, |
7c16ec58 MT |
7696 | &cpu_to_cpu_group, |
7697 | send_covered, tmpmask); | |
1da177e4 LT |
7698 | } |
7699 | #endif | |
7700 | ||
1e9f28fa SS |
7701 | #ifdef CONFIG_SCHED_MC |
7702 | /* Set up multi-core groups */ | |
abcd083a | 7703 | for_each_cpu(i, cpu_map) { |
6ca09dfc | 7704 | cpumask_and(this_core_map, cpu_coregroup_mask(i), cpu_map); |
96f874e2 | 7705 | if (i != cpumask_first(this_core_map)) |
1e9f28fa | 7706 | continue; |
7c16ec58 | 7707 | |
dd41f596 | 7708 | init_sched_build_groups(this_core_map, cpu_map, |
7c16ec58 MT |
7709 | &cpu_to_core_group, |
7710 | send_covered, tmpmask); | |
1e9f28fa SS |
7711 | } |
7712 | #endif | |
7713 | ||
1da177e4 | 7714 | /* Set up physical groups */ |
076ac2af | 7715 | for (i = 0; i < nr_node_ids; i++) { |
6ca09dfc | 7716 | cpumask_and(nodemask, cpumask_of_node(i), cpu_map); |
96f874e2 | 7717 | if (cpumask_empty(nodemask)) |
1da177e4 LT |
7718 | continue; |
7719 | ||
7c16ec58 MT |
7720 | init_sched_build_groups(nodemask, cpu_map, |
7721 | &cpu_to_phys_group, | |
7722 | send_covered, tmpmask); | |
1da177e4 LT |
7723 | } |
7724 | ||
7725 | #ifdef CONFIG_NUMA | |
7726 | /* Set up node groups */ | |
7c16ec58 | 7727 | if (sd_allnodes) { |
7c16ec58 MT |
7728 | init_sched_build_groups(cpu_map, cpu_map, |
7729 | &cpu_to_allnodes_group, | |
7730 | send_covered, tmpmask); | |
7731 | } | |
9c1cfda2 | 7732 | |
076ac2af | 7733 | for (i = 0; i < nr_node_ids; i++) { |
9c1cfda2 JH |
7734 | /* Set up node groups */ |
7735 | struct sched_group *sg, *prev; | |
9c1cfda2 JH |
7736 | int j; |
7737 | ||
96f874e2 | 7738 | cpumask_clear(covered); |
6ca09dfc | 7739 | cpumask_and(nodemask, cpumask_of_node(i), cpu_map); |
96f874e2 | 7740 | if (cpumask_empty(nodemask)) { |
d1b55138 | 7741 | sched_group_nodes[i] = NULL; |
9c1cfda2 | 7742 | continue; |
d1b55138 | 7743 | } |
9c1cfda2 | 7744 | |
4bdbaad3 | 7745 | sched_domain_node_span(i, domainspan); |
96f874e2 | 7746 | cpumask_and(domainspan, domainspan, cpu_map); |
9c1cfda2 | 7747 | |
6c99e9ad RR |
7748 | sg = kmalloc_node(sizeof(struct sched_group) + cpumask_size(), |
7749 | GFP_KERNEL, i); | |
51888ca2 SV |
7750 | if (!sg) { |
7751 | printk(KERN_WARNING "Can not alloc domain group for " | |
7752 | "node %d\n", i); | |
7753 | goto error; | |
7754 | } | |
9c1cfda2 | 7755 | sched_group_nodes[i] = sg; |
abcd083a | 7756 | for_each_cpu(j, nodemask) { |
9c1cfda2 | 7757 | struct sched_domain *sd; |
9761eea8 | 7758 | |
62ea9ceb | 7759 | sd = &per_cpu(node_domains, j).sd; |
9c1cfda2 | 7760 | sd->groups = sg; |
9c1cfda2 | 7761 | } |
5517d86b | 7762 | sg->__cpu_power = 0; |
758b2cdc | 7763 | cpumask_copy(sched_group_cpus(sg), nodemask); |
51888ca2 | 7764 | sg->next = sg; |
96f874e2 | 7765 | cpumask_or(covered, covered, nodemask); |
9c1cfda2 JH |
7766 | prev = sg; |
7767 | ||
076ac2af | 7768 | for (j = 0; j < nr_node_ids; j++) { |
076ac2af | 7769 | int n = (i + j) % nr_node_ids; |
9c1cfda2 | 7770 | |
96f874e2 RR |
7771 | cpumask_complement(notcovered, covered); |
7772 | cpumask_and(tmpmask, notcovered, cpu_map); | |
7773 | cpumask_and(tmpmask, tmpmask, domainspan); | |
7774 | if (cpumask_empty(tmpmask)) | |
9c1cfda2 JH |
7775 | break; |
7776 | ||
6ca09dfc | 7777 | cpumask_and(tmpmask, tmpmask, cpumask_of_node(n)); |
96f874e2 | 7778 | if (cpumask_empty(tmpmask)) |
9c1cfda2 JH |
7779 | continue; |
7780 | ||
6c99e9ad RR |
7781 | sg = kmalloc_node(sizeof(struct sched_group) + |
7782 | cpumask_size(), | |
15f0b676 | 7783 | GFP_KERNEL, i); |
9c1cfda2 JH |
7784 | if (!sg) { |
7785 | printk(KERN_WARNING | |
7786 | "Can not alloc domain group for node %d\n", j); | |
51888ca2 | 7787 | goto error; |
9c1cfda2 | 7788 | } |
5517d86b | 7789 | sg->__cpu_power = 0; |
758b2cdc | 7790 | cpumask_copy(sched_group_cpus(sg), tmpmask); |
51888ca2 | 7791 | sg->next = prev->next; |
96f874e2 | 7792 | cpumask_or(covered, covered, tmpmask); |
9c1cfda2 JH |
7793 | prev->next = sg; |
7794 | prev = sg; | |
7795 | } | |
9c1cfda2 | 7796 | } |
1da177e4 LT |
7797 | #endif |
7798 | ||
7799 | /* Calculate CPU power for physical packages and nodes */ | |
5c45bf27 | 7800 | #ifdef CONFIG_SCHED_SMT |
abcd083a | 7801 | for_each_cpu(i, cpu_map) { |
6c99e9ad | 7802 | struct sched_domain *sd = &per_cpu(cpu_domains, i).sd; |
dd41f596 | 7803 | |
89c4710e | 7804 | init_sched_groups_power(i, sd); |
5c45bf27 | 7805 | } |
1da177e4 | 7806 | #endif |
1e9f28fa | 7807 | #ifdef CONFIG_SCHED_MC |
abcd083a | 7808 | for_each_cpu(i, cpu_map) { |
6c99e9ad | 7809 | struct sched_domain *sd = &per_cpu(core_domains, i).sd; |
dd41f596 | 7810 | |
89c4710e | 7811 | init_sched_groups_power(i, sd); |
5c45bf27 SS |
7812 | } |
7813 | #endif | |
1e9f28fa | 7814 | |
abcd083a | 7815 | for_each_cpu(i, cpu_map) { |
6c99e9ad | 7816 | struct sched_domain *sd = &per_cpu(phys_domains, i).sd; |
dd41f596 | 7817 | |
89c4710e | 7818 | init_sched_groups_power(i, sd); |
1da177e4 LT |
7819 | } |
7820 | ||
9c1cfda2 | 7821 | #ifdef CONFIG_NUMA |
076ac2af | 7822 | for (i = 0; i < nr_node_ids; i++) |
08069033 | 7823 | init_numa_sched_groups_power(sched_group_nodes[i]); |
9c1cfda2 | 7824 | |
6711cab4 SS |
7825 | if (sd_allnodes) { |
7826 | struct sched_group *sg; | |
f712c0c7 | 7827 | |
96f874e2 | 7828 | cpu_to_allnodes_group(cpumask_first(cpu_map), cpu_map, &sg, |
7c16ec58 | 7829 | tmpmask); |
f712c0c7 SS |
7830 | init_numa_sched_groups_power(sg); |
7831 | } | |
9c1cfda2 JH |
7832 | #endif |
7833 | ||
1da177e4 | 7834 | /* Attach the domains */ |
abcd083a | 7835 | for_each_cpu(i, cpu_map) { |
1da177e4 LT |
7836 | struct sched_domain *sd; |
7837 | #ifdef CONFIG_SCHED_SMT | |
6c99e9ad | 7838 | sd = &per_cpu(cpu_domains, i).sd; |
1e9f28fa | 7839 | #elif defined(CONFIG_SCHED_MC) |
6c99e9ad | 7840 | sd = &per_cpu(core_domains, i).sd; |
1da177e4 | 7841 | #else |
6c99e9ad | 7842 | sd = &per_cpu(phys_domains, i).sd; |
1da177e4 | 7843 | #endif |
57d885fe | 7844 | cpu_attach_domain(sd, rd, i); |
1da177e4 | 7845 | } |
51888ca2 | 7846 | |
3404c8d9 RR |
7847 | err = 0; |
7848 | ||
7849 | free_tmpmask: | |
7850 | free_cpumask_var(tmpmask); | |
7851 | free_send_covered: | |
7852 | free_cpumask_var(send_covered); | |
7853 | free_this_core_map: | |
7854 | free_cpumask_var(this_core_map); | |
7855 | free_this_sibling_map: | |
7856 | free_cpumask_var(this_sibling_map); | |
7857 | free_nodemask: | |
7858 | free_cpumask_var(nodemask); | |
7859 | free_notcovered: | |
7860 | #ifdef CONFIG_NUMA | |
7861 | free_cpumask_var(notcovered); | |
7862 | free_covered: | |
7863 | free_cpumask_var(covered); | |
7864 | free_domainspan: | |
7865 | free_cpumask_var(domainspan); | |
7866 | out: | |
7867 | #endif | |
7868 | return err; | |
7869 | ||
7870 | free_sched_groups: | |
7871 | #ifdef CONFIG_NUMA | |
7872 | kfree(sched_group_nodes); | |
7873 | #endif | |
7874 | goto free_tmpmask; | |
51888ca2 | 7875 | |
a616058b | 7876 | #ifdef CONFIG_NUMA |
51888ca2 | 7877 | error: |
7c16ec58 | 7878 | free_sched_groups(cpu_map, tmpmask); |
c6c4927b | 7879 | free_rootdomain(rd); |
3404c8d9 | 7880 | goto free_tmpmask; |
a616058b | 7881 | #endif |
1da177e4 | 7882 | } |
029190c5 | 7883 | |
96f874e2 | 7884 | static int build_sched_domains(const struct cpumask *cpu_map) |
1d3504fc HS |
7885 | { |
7886 | return __build_sched_domains(cpu_map, NULL); | |
7887 | } | |
7888 | ||
96f874e2 | 7889 | static struct cpumask *doms_cur; /* current sched domains */ |
029190c5 | 7890 | static int ndoms_cur; /* number of sched domains in 'doms_cur' */ |
4285f594 IM |
7891 | static struct sched_domain_attr *dattr_cur; |
7892 | /* attribues of custom domains in 'doms_cur' */ | |
029190c5 PJ |
7893 | |
7894 | /* | |
7895 | * Special case: If a kmalloc of a doms_cur partition (array of | |
4212823f RR |
7896 | * cpumask) fails, then fallback to a single sched domain, |
7897 | * as determined by the single cpumask fallback_doms. | |
029190c5 | 7898 | */ |
4212823f | 7899 | static cpumask_var_t fallback_doms; |
029190c5 | 7900 | |
ee79d1bd HC |
7901 | /* |
7902 | * arch_update_cpu_topology lets virtualized architectures update the | |
7903 | * cpu core maps. It is supposed to return 1 if the topology changed | |
7904 | * or 0 if it stayed the same. | |
7905 | */ | |
7906 | int __attribute__((weak)) arch_update_cpu_topology(void) | |
22e52b07 | 7907 | { |
ee79d1bd | 7908 | return 0; |
22e52b07 HC |
7909 | } |
7910 | ||
1a20ff27 | 7911 | /* |
41a2d6cf | 7912 | * Set up scheduler domains and groups. Callers must hold the hotplug lock. |
029190c5 PJ |
7913 | * For now this just excludes isolated cpus, but could be used to |
7914 | * exclude other special cases in the future. | |
1a20ff27 | 7915 | */ |
96f874e2 | 7916 | static int arch_init_sched_domains(const struct cpumask *cpu_map) |
1a20ff27 | 7917 | { |
7378547f MM |
7918 | int err; |
7919 | ||
22e52b07 | 7920 | arch_update_cpu_topology(); |
029190c5 | 7921 | ndoms_cur = 1; |
96f874e2 | 7922 | doms_cur = kmalloc(cpumask_size(), GFP_KERNEL); |
029190c5 | 7923 | if (!doms_cur) |
4212823f | 7924 | doms_cur = fallback_doms; |
dcc30a35 | 7925 | cpumask_andnot(doms_cur, cpu_map, cpu_isolated_map); |
1d3504fc | 7926 | dattr_cur = NULL; |
7378547f | 7927 | err = build_sched_domains(doms_cur); |
6382bc90 | 7928 | register_sched_domain_sysctl(); |
7378547f MM |
7929 | |
7930 | return err; | |
1a20ff27 DG |
7931 | } |
7932 | ||
96f874e2 RR |
7933 | static void arch_destroy_sched_domains(const struct cpumask *cpu_map, |
7934 | struct cpumask *tmpmask) | |
1da177e4 | 7935 | { |
7c16ec58 | 7936 | free_sched_groups(cpu_map, tmpmask); |
9c1cfda2 | 7937 | } |
1da177e4 | 7938 | |
1a20ff27 DG |
7939 | /* |
7940 | * Detach sched domains from a group of cpus specified in cpu_map | |
7941 | * These cpus will now be attached to the NULL domain | |
7942 | */ | |
96f874e2 | 7943 | static void detach_destroy_domains(const struct cpumask *cpu_map) |
1a20ff27 | 7944 | { |
96f874e2 RR |
7945 | /* Save because hotplug lock held. */ |
7946 | static DECLARE_BITMAP(tmpmask, CONFIG_NR_CPUS); | |
1a20ff27 DG |
7947 | int i; |
7948 | ||
abcd083a | 7949 | for_each_cpu(i, cpu_map) |
57d885fe | 7950 | cpu_attach_domain(NULL, &def_root_domain, i); |
1a20ff27 | 7951 | synchronize_sched(); |
96f874e2 | 7952 | arch_destroy_sched_domains(cpu_map, to_cpumask(tmpmask)); |
1a20ff27 DG |
7953 | } |
7954 | ||
1d3504fc HS |
7955 | /* handle null as "default" */ |
7956 | static int dattrs_equal(struct sched_domain_attr *cur, int idx_cur, | |
7957 | struct sched_domain_attr *new, int idx_new) | |
7958 | { | |
7959 | struct sched_domain_attr tmp; | |
7960 | ||
7961 | /* fast path */ | |
7962 | if (!new && !cur) | |
7963 | return 1; | |
7964 | ||
7965 | tmp = SD_ATTR_INIT; | |
7966 | return !memcmp(cur ? (cur + idx_cur) : &tmp, | |
7967 | new ? (new + idx_new) : &tmp, | |
7968 | sizeof(struct sched_domain_attr)); | |
7969 | } | |
7970 | ||
029190c5 PJ |
7971 | /* |
7972 | * Partition sched domains as specified by the 'ndoms_new' | |
41a2d6cf | 7973 | * cpumasks in the array doms_new[] of cpumasks. This compares |
029190c5 PJ |
7974 | * doms_new[] to the current sched domain partitioning, doms_cur[]. |
7975 | * It destroys each deleted domain and builds each new domain. | |
7976 | * | |
96f874e2 | 7977 | * 'doms_new' is an array of cpumask's of length 'ndoms_new'. |
41a2d6cf IM |
7978 | * The masks don't intersect (don't overlap.) We should setup one |
7979 | * sched domain for each mask. CPUs not in any of the cpumasks will | |
7980 | * not be load balanced. If the same cpumask appears both in the | |
029190c5 PJ |
7981 | * current 'doms_cur' domains and in the new 'doms_new', we can leave |
7982 | * it as it is. | |
7983 | * | |
41a2d6cf IM |
7984 | * The passed in 'doms_new' should be kmalloc'd. This routine takes |
7985 | * ownership of it and will kfree it when done with it. If the caller | |
700018e0 LZ |
7986 | * failed the kmalloc call, then it can pass in doms_new == NULL && |
7987 | * ndoms_new == 1, and partition_sched_domains() will fallback to | |
7988 | * the single partition 'fallback_doms', it also forces the domains | |
7989 | * to be rebuilt. | |
029190c5 | 7990 | * |
96f874e2 | 7991 | * If doms_new == NULL it will be replaced with cpu_online_mask. |
700018e0 LZ |
7992 | * ndoms_new == 0 is a special case for destroying existing domains, |
7993 | * and it will not create the default domain. | |
dfb512ec | 7994 | * |
029190c5 PJ |
7995 | * Call with hotplug lock held |
7996 | */ | |
96f874e2 RR |
7997 | /* FIXME: Change to struct cpumask *doms_new[] */ |
7998 | void partition_sched_domains(int ndoms_new, struct cpumask *doms_new, | |
1d3504fc | 7999 | struct sched_domain_attr *dattr_new) |
029190c5 | 8000 | { |
dfb512ec | 8001 | int i, j, n; |
d65bd5ec | 8002 | int new_topology; |
029190c5 | 8003 | |
712555ee | 8004 | mutex_lock(&sched_domains_mutex); |
a1835615 | 8005 | |
7378547f MM |
8006 | /* always unregister in case we don't destroy any domains */ |
8007 | unregister_sched_domain_sysctl(); | |
8008 | ||
d65bd5ec HC |
8009 | /* Let architecture update cpu core mappings. */ |
8010 | new_topology = arch_update_cpu_topology(); | |
8011 | ||
dfb512ec | 8012 | n = doms_new ? ndoms_new : 0; |
029190c5 PJ |
8013 | |
8014 | /* Destroy deleted domains */ | |
8015 | for (i = 0; i < ndoms_cur; i++) { | |
d65bd5ec | 8016 | for (j = 0; j < n && !new_topology; j++) { |
96f874e2 | 8017 | if (cpumask_equal(&doms_cur[i], &doms_new[j]) |
1d3504fc | 8018 | && dattrs_equal(dattr_cur, i, dattr_new, j)) |
029190c5 PJ |
8019 | goto match1; |
8020 | } | |
8021 | /* no match - a current sched domain not in new doms_new[] */ | |
8022 | detach_destroy_domains(doms_cur + i); | |
8023 | match1: | |
8024 | ; | |
8025 | } | |
8026 | ||
e761b772 MK |
8027 | if (doms_new == NULL) { |
8028 | ndoms_cur = 0; | |
4212823f | 8029 | doms_new = fallback_doms; |
dcc30a35 | 8030 | cpumask_andnot(&doms_new[0], cpu_online_mask, cpu_isolated_map); |
faa2f98f | 8031 | WARN_ON_ONCE(dattr_new); |
e761b772 MK |
8032 | } |
8033 | ||
029190c5 PJ |
8034 | /* Build new domains */ |
8035 | for (i = 0; i < ndoms_new; i++) { | |
d65bd5ec | 8036 | for (j = 0; j < ndoms_cur && !new_topology; j++) { |
96f874e2 | 8037 | if (cpumask_equal(&doms_new[i], &doms_cur[j]) |
1d3504fc | 8038 | && dattrs_equal(dattr_new, i, dattr_cur, j)) |
029190c5 PJ |
8039 | goto match2; |
8040 | } | |
8041 | /* no match - add a new doms_new */ | |
1d3504fc HS |
8042 | __build_sched_domains(doms_new + i, |
8043 | dattr_new ? dattr_new + i : NULL); | |
029190c5 PJ |
8044 | match2: |
8045 | ; | |
8046 | } | |
8047 | ||
8048 | /* Remember the new sched domains */ | |
4212823f | 8049 | if (doms_cur != fallback_doms) |
029190c5 | 8050 | kfree(doms_cur); |
1d3504fc | 8051 | kfree(dattr_cur); /* kfree(NULL) is safe */ |
029190c5 | 8052 | doms_cur = doms_new; |
1d3504fc | 8053 | dattr_cur = dattr_new; |
029190c5 | 8054 | ndoms_cur = ndoms_new; |
7378547f MM |
8055 | |
8056 | register_sched_domain_sysctl(); | |
a1835615 | 8057 | |
712555ee | 8058 | mutex_unlock(&sched_domains_mutex); |
029190c5 PJ |
8059 | } |
8060 | ||
5c45bf27 | 8061 | #if defined(CONFIG_SCHED_MC) || defined(CONFIG_SCHED_SMT) |
c70f22d2 | 8062 | static void arch_reinit_sched_domains(void) |
5c45bf27 | 8063 | { |
95402b38 | 8064 | get_online_cpus(); |
dfb512ec MK |
8065 | |
8066 | /* Destroy domains first to force the rebuild */ | |
8067 | partition_sched_domains(0, NULL, NULL); | |
8068 | ||
e761b772 | 8069 | rebuild_sched_domains(); |
95402b38 | 8070 | put_online_cpus(); |
5c45bf27 SS |
8071 | } |
8072 | ||
8073 | static ssize_t sched_power_savings_store(const char *buf, size_t count, int smt) | |
8074 | { | |
afb8a9b7 | 8075 | unsigned int level = 0; |
5c45bf27 | 8076 | |
afb8a9b7 GS |
8077 | if (sscanf(buf, "%u", &level) != 1) |
8078 | return -EINVAL; | |
8079 | ||
8080 | /* | |
8081 | * level is always be positive so don't check for | |
8082 | * level < POWERSAVINGS_BALANCE_NONE which is 0 | |
8083 | * What happens on 0 or 1 byte write, | |
8084 | * need to check for count as well? | |
8085 | */ | |
5c45bf27 | 8086 | |
afb8a9b7 | 8087 | if (level >= MAX_POWERSAVINGS_BALANCE_LEVELS) |
5c45bf27 SS |
8088 | return -EINVAL; |
8089 | ||
8090 | if (smt) | |
afb8a9b7 | 8091 | sched_smt_power_savings = level; |
5c45bf27 | 8092 | else |
afb8a9b7 | 8093 | sched_mc_power_savings = level; |
5c45bf27 | 8094 | |
c70f22d2 | 8095 | arch_reinit_sched_domains(); |
5c45bf27 | 8096 | |
c70f22d2 | 8097 | return count; |
5c45bf27 SS |
8098 | } |
8099 | ||
5c45bf27 | 8100 | #ifdef CONFIG_SCHED_MC |
f718cd4a AK |
8101 | static ssize_t sched_mc_power_savings_show(struct sysdev_class *class, |
8102 | char *page) | |
5c45bf27 SS |
8103 | { |
8104 | return sprintf(page, "%u\n", sched_mc_power_savings); | |
8105 | } | |
f718cd4a | 8106 | static ssize_t sched_mc_power_savings_store(struct sysdev_class *class, |
48f24c4d | 8107 | const char *buf, size_t count) |
5c45bf27 SS |
8108 | { |
8109 | return sched_power_savings_store(buf, count, 0); | |
8110 | } | |
f718cd4a AK |
8111 | static SYSDEV_CLASS_ATTR(sched_mc_power_savings, 0644, |
8112 | sched_mc_power_savings_show, | |
8113 | sched_mc_power_savings_store); | |
5c45bf27 SS |
8114 | #endif |
8115 | ||
8116 | #ifdef CONFIG_SCHED_SMT | |
f718cd4a AK |
8117 | static ssize_t sched_smt_power_savings_show(struct sysdev_class *dev, |
8118 | char *page) | |
5c45bf27 SS |
8119 | { |
8120 | return sprintf(page, "%u\n", sched_smt_power_savings); | |
8121 | } | |
f718cd4a | 8122 | static ssize_t sched_smt_power_savings_store(struct sysdev_class *dev, |
48f24c4d | 8123 | const char *buf, size_t count) |
5c45bf27 SS |
8124 | { |
8125 | return sched_power_savings_store(buf, count, 1); | |
8126 | } | |
f718cd4a AK |
8127 | static SYSDEV_CLASS_ATTR(sched_smt_power_savings, 0644, |
8128 | sched_smt_power_savings_show, | |
6707de00 AB |
8129 | sched_smt_power_savings_store); |
8130 | #endif | |
8131 | ||
39aac648 | 8132 | int __init sched_create_sysfs_power_savings_entries(struct sysdev_class *cls) |
6707de00 AB |
8133 | { |
8134 | int err = 0; | |
8135 | ||
8136 | #ifdef CONFIG_SCHED_SMT | |
8137 | if (smt_capable()) | |
8138 | err = sysfs_create_file(&cls->kset.kobj, | |
8139 | &attr_sched_smt_power_savings.attr); | |
8140 | #endif | |
8141 | #ifdef CONFIG_SCHED_MC | |
8142 | if (!err && mc_capable()) | |
8143 | err = sysfs_create_file(&cls->kset.kobj, | |
8144 | &attr_sched_mc_power_savings.attr); | |
8145 | #endif | |
8146 | return err; | |
8147 | } | |
6d6bc0ad | 8148 | #endif /* CONFIG_SCHED_MC || CONFIG_SCHED_SMT */ |
5c45bf27 | 8149 | |
e761b772 | 8150 | #ifndef CONFIG_CPUSETS |
1da177e4 | 8151 | /* |
e761b772 MK |
8152 | * Add online and remove offline CPUs from the scheduler domains. |
8153 | * When cpusets are enabled they take over this function. | |
1da177e4 LT |
8154 | */ |
8155 | static int update_sched_domains(struct notifier_block *nfb, | |
8156 | unsigned long action, void *hcpu) | |
e761b772 MK |
8157 | { |
8158 | switch (action) { | |
8159 | case CPU_ONLINE: | |
8160 | case CPU_ONLINE_FROZEN: | |
8161 | case CPU_DEAD: | |
8162 | case CPU_DEAD_FROZEN: | |
dfb512ec | 8163 | partition_sched_domains(1, NULL, NULL); |
e761b772 MK |
8164 | return NOTIFY_OK; |
8165 | ||
8166 | default: | |
8167 | return NOTIFY_DONE; | |
8168 | } | |
8169 | } | |
8170 | #endif | |
8171 | ||
8172 | static int update_runtime(struct notifier_block *nfb, | |
8173 | unsigned long action, void *hcpu) | |
1da177e4 | 8174 | { |
7def2be1 PZ |
8175 | int cpu = (int)(long)hcpu; |
8176 | ||
1da177e4 | 8177 | switch (action) { |
1da177e4 | 8178 | case CPU_DOWN_PREPARE: |
8bb78442 | 8179 | case CPU_DOWN_PREPARE_FROZEN: |
7def2be1 | 8180 | disable_runtime(cpu_rq(cpu)); |
1da177e4 LT |
8181 | return NOTIFY_OK; |
8182 | ||
1da177e4 | 8183 | case CPU_DOWN_FAILED: |
8bb78442 | 8184 | case CPU_DOWN_FAILED_FROZEN: |
1da177e4 | 8185 | case CPU_ONLINE: |
8bb78442 | 8186 | case CPU_ONLINE_FROZEN: |
7def2be1 | 8187 | enable_runtime(cpu_rq(cpu)); |
e761b772 MK |
8188 | return NOTIFY_OK; |
8189 | ||
1da177e4 LT |
8190 | default: |
8191 | return NOTIFY_DONE; | |
8192 | } | |
1da177e4 | 8193 | } |
1da177e4 LT |
8194 | |
8195 | void __init sched_init_smp(void) | |
8196 | { | |
dcc30a35 RR |
8197 | cpumask_var_t non_isolated_cpus; |
8198 | ||
8199 | alloc_cpumask_var(&non_isolated_cpus, GFP_KERNEL); | |
5c1e1767 | 8200 | |
434d53b0 MT |
8201 | #if defined(CONFIG_NUMA) |
8202 | sched_group_nodes_bycpu = kzalloc(nr_cpu_ids * sizeof(void **), | |
8203 | GFP_KERNEL); | |
8204 | BUG_ON(sched_group_nodes_bycpu == NULL); | |
8205 | #endif | |
95402b38 | 8206 | get_online_cpus(); |
712555ee | 8207 | mutex_lock(&sched_domains_mutex); |
dcc30a35 RR |
8208 | arch_init_sched_domains(cpu_online_mask); |
8209 | cpumask_andnot(non_isolated_cpus, cpu_possible_mask, cpu_isolated_map); | |
8210 | if (cpumask_empty(non_isolated_cpus)) | |
8211 | cpumask_set_cpu(smp_processor_id(), non_isolated_cpus); | |
712555ee | 8212 | mutex_unlock(&sched_domains_mutex); |
95402b38 | 8213 | put_online_cpus(); |
e761b772 MK |
8214 | |
8215 | #ifndef CONFIG_CPUSETS | |
1da177e4 LT |
8216 | /* XXX: Theoretical race here - CPU may be hotplugged now */ |
8217 | hotcpu_notifier(update_sched_domains, 0); | |
e761b772 MK |
8218 | #endif |
8219 | ||
8220 | /* RT runtime code needs to handle some hotplug events */ | |
8221 | hotcpu_notifier(update_runtime, 0); | |
8222 | ||
b328ca18 | 8223 | init_hrtick(); |
5c1e1767 NP |
8224 | |
8225 | /* Move init over to a non-isolated CPU */ | |
dcc30a35 | 8226 | if (set_cpus_allowed_ptr(current, non_isolated_cpus) < 0) |
5c1e1767 | 8227 | BUG(); |
19978ca6 | 8228 | sched_init_granularity(); |
dcc30a35 | 8229 | free_cpumask_var(non_isolated_cpus); |
4212823f RR |
8230 | |
8231 | alloc_cpumask_var(&fallback_doms, GFP_KERNEL); | |
0e3900e6 | 8232 | init_sched_rt_class(); |
1da177e4 LT |
8233 | } |
8234 | #else | |
8235 | void __init sched_init_smp(void) | |
8236 | { | |
19978ca6 | 8237 | sched_init_granularity(); |
1da177e4 LT |
8238 | } |
8239 | #endif /* CONFIG_SMP */ | |
8240 | ||
8241 | int in_sched_functions(unsigned long addr) | |
8242 | { | |
1da177e4 LT |
8243 | return in_lock_functions(addr) || |
8244 | (addr >= (unsigned long)__sched_text_start | |
8245 | && addr < (unsigned long)__sched_text_end); | |
8246 | } | |
8247 | ||
a9957449 | 8248 | static void init_cfs_rq(struct cfs_rq *cfs_rq, struct rq *rq) |
dd41f596 IM |
8249 | { |
8250 | cfs_rq->tasks_timeline = RB_ROOT; | |
4a55bd5e | 8251 | INIT_LIST_HEAD(&cfs_rq->tasks); |
dd41f596 IM |
8252 | #ifdef CONFIG_FAIR_GROUP_SCHED |
8253 | cfs_rq->rq = rq; | |
8254 | #endif | |
67e9fb2a | 8255 | cfs_rq->min_vruntime = (u64)(-(1LL << 20)); |
dd41f596 IM |
8256 | } |
8257 | ||
fa85ae24 PZ |
8258 | static void init_rt_rq(struct rt_rq *rt_rq, struct rq *rq) |
8259 | { | |
8260 | struct rt_prio_array *array; | |
8261 | int i; | |
8262 | ||
8263 | array = &rt_rq->active; | |
8264 | for (i = 0; i < MAX_RT_PRIO; i++) { | |
8265 | INIT_LIST_HEAD(array->queue + i); | |
8266 | __clear_bit(i, array->bitmap); | |
8267 | } | |
8268 | /* delimiter for bitsearch: */ | |
8269 | __set_bit(MAX_RT_PRIO, array->bitmap); | |
8270 | ||
052f1dc7 | 8271 | #if defined CONFIG_SMP || defined CONFIG_RT_GROUP_SCHED |
48d5e258 PZ |
8272 | rt_rq->highest_prio = MAX_RT_PRIO; |
8273 | #endif | |
fa85ae24 PZ |
8274 | #ifdef CONFIG_SMP |
8275 | rt_rq->rt_nr_migratory = 0; | |
fa85ae24 PZ |
8276 | rt_rq->overloaded = 0; |
8277 | #endif | |
8278 | ||
8279 | rt_rq->rt_time = 0; | |
8280 | rt_rq->rt_throttled = 0; | |
ac086bc2 PZ |
8281 | rt_rq->rt_runtime = 0; |
8282 | spin_lock_init(&rt_rq->rt_runtime_lock); | |
6f505b16 | 8283 | |
052f1dc7 | 8284 | #ifdef CONFIG_RT_GROUP_SCHED |
23b0fdfc | 8285 | rt_rq->rt_nr_boosted = 0; |
6f505b16 PZ |
8286 | rt_rq->rq = rq; |
8287 | #endif | |
fa85ae24 PZ |
8288 | } |
8289 | ||
6f505b16 | 8290 | #ifdef CONFIG_FAIR_GROUP_SCHED |
ec7dc8ac DG |
8291 | static void init_tg_cfs_entry(struct task_group *tg, struct cfs_rq *cfs_rq, |
8292 | struct sched_entity *se, int cpu, int add, | |
8293 | struct sched_entity *parent) | |
6f505b16 | 8294 | { |
ec7dc8ac | 8295 | struct rq *rq = cpu_rq(cpu); |
6f505b16 PZ |
8296 | tg->cfs_rq[cpu] = cfs_rq; |
8297 | init_cfs_rq(cfs_rq, rq); | |
8298 | cfs_rq->tg = tg; | |
8299 | if (add) | |
8300 | list_add(&cfs_rq->leaf_cfs_rq_list, &rq->leaf_cfs_rq_list); | |
8301 | ||
8302 | tg->se[cpu] = se; | |
354d60c2 DG |
8303 | /* se could be NULL for init_task_group */ |
8304 | if (!se) | |
8305 | return; | |
8306 | ||
ec7dc8ac DG |
8307 | if (!parent) |
8308 | se->cfs_rq = &rq->cfs; | |
8309 | else | |
8310 | se->cfs_rq = parent->my_q; | |
8311 | ||
6f505b16 PZ |
8312 | se->my_q = cfs_rq; |
8313 | se->load.weight = tg->shares; | |
e05510d0 | 8314 | se->load.inv_weight = 0; |
ec7dc8ac | 8315 | se->parent = parent; |
6f505b16 | 8316 | } |
052f1dc7 | 8317 | #endif |
6f505b16 | 8318 | |
052f1dc7 | 8319 | #ifdef CONFIG_RT_GROUP_SCHED |
ec7dc8ac DG |
8320 | static void init_tg_rt_entry(struct task_group *tg, struct rt_rq *rt_rq, |
8321 | struct sched_rt_entity *rt_se, int cpu, int add, | |
8322 | struct sched_rt_entity *parent) | |
6f505b16 | 8323 | { |
ec7dc8ac DG |
8324 | struct rq *rq = cpu_rq(cpu); |
8325 | ||
6f505b16 PZ |
8326 | tg->rt_rq[cpu] = rt_rq; |
8327 | init_rt_rq(rt_rq, rq); | |
8328 | rt_rq->tg = tg; | |
8329 | rt_rq->rt_se = rt_se; | |
ac086bc2 | 8330 | rt_rq->rt_runtime = tg->rt_bandwidth.rt_runtime; |
6f505b16 PZ |
8331 | if (add) |
8332 | list_add(&rt_rq->leaf_rt_rq_list, &rq->leaf_rt_rq_list); | |
8333 | ||
8334 | tg->rt_se[cpu] = rt_se; | |
354d60c2 DG |
8335 | if (!rt_se) |
8336 | return; | |
8337 | ||
ec7dc8ac DG |
8338 | if (!parent) |
8339 | rt_se->rt_rq = &rq->rt; | |
8340 | else | |
8341 | rt_se->rt_rq = parent->my_q; | |
8342 | ||
6f505b16 | 8343 | rt_se->my_q = rt_rq; |
ec7dc8ac | 8344 | rt_se->parent = parent; |
6f505b16 PZ |
8345 | INIT_LIST_HEAD(&rt_se->run_list); |
8346 | } | |
8347 | #endif | |
8348 | ||
1da177e4 LT |
8349 | void __init sched_init(void) |
8350 | { | |
dd41f596 | 8351 | int i, j; |
434d53b0 MT |
8352 | unsigned long alloc_size = 0, ptr; |
8353 | ||
8354 | #ifdef CONFIG_FAIR_GROUP_SCHED | |
8355 | alloc_size += 2 * nr_cpu_ids * sizeof(void **); | |
8356 | #endif | |
8357 | #ifdef CONFIG_RT_GROUP_SCHED | |
8358 | alloc_size += 2 * nr_cpu_ids * sizeof(void **); | |
eff766a6 PZ |
8359 | #endif |
8360 | #ifdef CONFIG_USER_SCHED | |
8361 | alloc_size *= 2; | |
434d53b0 MT |
8362 | #endif |
8363 | /* | |
8364 | * As sched_init() is called before page_alloc is setup, | |
8365 | * we use alloc_bootmem(). | |
8366 | */ | |
8367 | if (alloc_size) { | |
5a9d3225 | 8368 | ptr = (unsigned long)alloc_bootmem(alloc_size); |
434d53b0 MT |
8369 | |
8370 | #ifdef CONFIG_FAIR_GROUP_SCHED | |
8371 | init_task_group.se = (struct sched_entity **)ptr; | |
8372 | ptr += nr_cpu_ids * sizeof(void **); | |
8373 | ||
8374 | init_task_group.cfs_rq = (struct cfs_rq **)ptr; | |
8375 | ptr += nr_cpu_ids * sizeof(void **); | |
eff766a6 PZ |
8376 | |
8377 | #ifdef CONFIG_USER_SCHED | |
8378 | root_task_group.se = (struct sched_entity **)ptr; | |
8379 | ptr += nr_cpu_ids * sizeof(void **); | |
8380 | ||
8381 | root_task_group.cfs_rq = (struct cfs_rq **)ptr; | |
8382 | ptr += nr_cpu_ids * sizeof(void **); | |
6d6bc0ad DG |
8383 | #endif /* CONFIG_USER_SCHED */ |
8384 | #endif /* CONFIG_FAIR_GROUP_SCHED */ | |
434d53b0 MT |
8385 | #ifdef CONFIG_RT_GROUP_SCHED |
8386 | init_task_group.rt_se = (struct sched_rt_entity **)ptr; | |
8387 | ptr += nr_cpu_ids * sizeof(void **); | |
8388 | ||
8389 | init_task_group.rt_rq = (struct rt_rq **)ptr; | |
eff766a6 PZ |
8390 | ptr += nr_cpu_ids * sizeof(void **); |
8391 | ||
8392 | #ifdef CONFIG_USER_SCHED | |
8393 | root_task_group.rt_se = (struct sched_rt_entity **)ptr; | |
8394 | ptr += nr_cpu_ids * sizeof(void **); | |
8395 | ||
8396 | root_task_group.rt_rq = (struct rt_rq **)ptr; | |
8397 | ptr += nr_cpu_ids * sizeof(void **); | |
6d6bc0ad DG |
8398 | #endif /* CONFIG_USER_SCHED */ |
8399 | #endif /* CONFIG_RT_GROUP_SCHED */ | |
434d53b0 | 8400 | } |
dd41f596 | 8401 | |
57d885fe GH |
8402 | #ifdef CONFIG_SMP |
8403 | init_defrootdomain(); | |
8404 | #endif | |
8405 | ||
d0b27fa7 PZ |
8406 | init_rt_bandwidth(&def_rt_bandwidth, |
8407 | global_rt_period(), global_rt_runtime()); | |
8408 | ||
8409 | #ifdef CONFIG_RT_GROUP_SCHED | |
8410 | init_rt_bandwidth(&init_task_group.rt_bandwidth, | |
8411 | global_rt_period(), global_rt_runtime()); | |
eff766a6 PZ |
8412 | #ifdef CONFIG_USER_SCHED |
8413 | init_rt_bandwidth(&root_task_group.rt_bandwidth, | |
8414 | global_rt_period(), RUNTIME_INF); | |
6d6bc0ad DG |
8415 | #endif /* CONFIG_USER_SCHED */ |
8416 | #endif /* CONFIG_RT_GROUP_SCHED */ | |
d0b27fa7 | 8417 | |
052f1dc7 | 8418 | #ifdef CONFIG_GROUP_SCHED |
6f505b16 | 8419 | list_add(&init_task_group.list, &task_groups); |
f473aa5e PZ |
8420 | INIT_LIST_HEAD(&init_task_group.children); |
8421 | ||
8422 | #ifdef CONFIG_USER_SCHED | |
8423 | INIT_LIST_HEAD(&root_task_group.children); | |
8424 | init_task_group.parent = &root_task_group; | |
8425 | list_add(&init_task_group.siblings, &root_task_group.children); | |
6d6bc0ad DG |
8426 | #endif /* CONFIG_USER_SCHED */ |
8427 | #endif /* CONFIG_GROUP_SCHED */ | |
6f505b16 | 8428 | |
0a945022 | 8429 | for_each_possible_cpu(i) { |
70b97a7f | 8430 | struct rq *rq; |
1da177e4 LT |
8431 | |
8432 | rq = cpu_rq(i); | |
8433 | spin_lock_init(&rq->lock); | |
7897986b | 8434 | rq->nr_running = 0; |
dd41f596 | 8435 | init_cfs_rq(&rq->cfs, rq); |
6f505b16 | 8436 | init_rt_rq(&rq->rt, rq); |
dd41f596 | 8437 | #ifdef CONFIG_FAIR_GROUP_SCHED |
4cf86d77 | 8438 | init_task_group.shares = init_task_group_load; |
6f505b16 | 8439 | INIT_LIST_HEAD(&rq->leaf_cfs_rq_list); |
354d60c2 DG |
8440 | #ifdef CONFIG_CGROUP_SCHED |
8441 | /* | |
8442 | * How much cpu bandwidth does init_task_group get? | |
8443 | * | |
8444 | * In case of task-groups formed thr' the cgroup filesystem, it | |
8445 | * gets 100% of the cpu resources in the system. This overall | |
8446 | * system cpu resource is divided among the tasks of | |
8447 | * init_task_group and its child task-groups in a fair manner, | |
8448 | * based on each entity's (task or task-group's) weight | |
8449 | * (se->load.weight). | |
8450 | * | |
8451 | * In other words, if init_task_group has 10 tasks of weight | |
8452 | * 1024) and two child groups A0 and A1 (of weight 1024 each), | |
8453 | * then A0's share of the cpu resource is: | |
8454 | * | |
8455 | * A0's bandwidth = 1024 / (10*1024 + 1024 + 1024) = 8.33% | |
8456 | * | |
8457 | * We achieve this by letting init_task_group's tasks sit | |
8458 | * directly in rq->cfs (i.e init_task_group->se[] = NULL). | |
8459 | */ | |
ec7dc8ac | 8460 | init_tg_cfs_entry(&init_task_group, &rq->cfs, NULL, i, 1, NULL); |
354d60c2 | 8461 | #elif defined CONFIG_USER_SCHED |
eff766a6 PZ |
8462 | root_task_group.shares = NICE_0_LOAD; |
8463 | init_tg_cfs_entry(&root_task_group, &rq->cfs, NULL, i, 0, NULL); | |
354d60c2 DG |
8464 | /* |
8465 | * In case of task-groups formed thr' the user id of tasks, | |
8466 | * init_task_group represents tasks belonging to root user. | |
8467 | * Hence it forms a sibling of all subsequent groups formed. | |
8468 | * In this case, init_task_group gets only a fraction of overall | |
8469 | * system cpu resource, based on the weight assigned to root | |
8470 | * user's cpu share (INIT_TASK_GROUP_LOAD). This is accomplished | |
8471 | * by letting tasks of init_task_group sit in a separate cfs_rq | |
8472 | * (init_cfs_rq) and having one entity represent this group of | |
8473 | * tasks in rq->cfs (i.e init_task_group->se[] != NULL). | |
8474 | */ | |
ec7dc8ac | 8475 | init_tg_cfs_entry(&init_task_group, |
6f505b16 | 8476 | &per_cpu(init_cfs_rq, i), |
eff766a6 PZ |
8477 | &per_cpu(init_sched_entity, i), i, 1, |
8478 | root_task_group.se[i]); | |
6f505b16 | 8479 | |
052f1dc7 | 8480 | #endif |
354d60c2 DG |
8481 | #endif /* CONFIG_FAIR_GROUP_SCHED */ |
8482 | ||
8483 | rq->rt.rt_runtime = def_rt_bandwidth.rt_runtime; | |
052f1dc7 | 8484 | #ifdef CONFIG_RT_GROUP_SCHED |
6f505b16 | 8485 | INIT_LIST_HEAD(&rq->leaf_rt_rq_list); |
354d60c2 | 8486 | #ifdef CONFIG_CGROUP_SCHED |
ec7dc8ac | 8487 | init_tg_rt_entry(&init_task_group, &rq->rt, NULL, i, 1, NULL); |
354d60c2 | 8488 | #elif defined CONFIG_USER_SCHED |
eff766a6 | 8489 | init_tg_rt_entry(&root_task_group, &rq->rt, NULL, i, 0, NULL); |
ec7dc8ac | 8490 | init_tg_rt_entry(&init_task_group, |
6f505b16 | 8491 | &per_cpu(init_rt_rq, i), |
eff766a6 PZ |
8492 | &per_cpu(init_sched_rt_entity, i), i, 1, |
8493 | root_task_group.rt_se[i]); | |
354d60c2 | 8494 | #endif |
dd41f596 | 8495 | #endif |
1da177e4 | 8496 | |
dd41f596 IM |
8497 | for (j = 0; j < CPU_LOAD_IDX_MAX; j++) |
8498 | rq->cpu_load[j] = 0; | |
1da177e4 | 8499 | #ifdef CONFIG_SMP |
41c7ce9a | 8500 | rq->sd = NULL; |
57d885fe | 8501 | rq->rd = NULL; |
1da177e4 | 8502 | rq->active_balance = 0; |
dd41f596 | 8503 | rq->next_balance = jiffies; |
1da177e4 | 8504 | rq->push_cpu = 0; |
0a2966b4 | 8505 | rq->cpu = i; |
1f11eb6a | 8506 | rq->online = 0; |
1da177e4 LT |
8507 | rq->migration_thread = NULL; |
8508 | INIT_LIST_HEAD(&rq->migration_queue); | |
dc938520 | 8509 | rq_attach_root(rq, &def_root_domain); |
1da177e4 | 8510 | #endif |
8f4d37ec | 8511 | init_rq_hrtick(rq); |
1da177e4 | 8512 | atomic_set(&rq->nr_iowait, 0); |
1da177e4 LT |
8513 | } |
8514 | ||
2dd73a4f | 8515 | set_load_weight(&init_task); |
b50f60ce | 8516 | |
e107be36 AK |
8517 | #ifdef CONFIG_PREEMPT_NOTIFIERS |
8518 | INIT_HLIST_HEAD(&init_task.preempt_notifiers); | |
8519 | #endif | |
8520 | ||
c9819f45 | 8521 | #ifdef CONFIG_SMP |
962cf36c | 8522 | open_softirq(SCHED_SOFTIRQ, run_rebalance_domains); |
c9819f45 CL |
8523 | #endif |
8524 | ||
b50f60ce HC |
8525 | #ifdef CONFIG_RT_MUTEXES |
8526 | plist_head_init(&init_task.pi_waiters, &init_task.pi_lock); | |
8527 | #endif | |
8528 | ||
1da177e4 LT |
8529 | /* |
8530 | * The boot idle thread does lazy MMU switching as well: | |
8531 | */ | |
8532 | atomic_inc(&init_mm.mm_count); | |
8533 | enter_lazy_tlb(&init_mm, current); | |
8534 | ||
8535 | /* | |
8536 | * Make us the idle thread. Technically, schedule() should not be | |
8537 | * called from this thread, however somewhere below it might be, | |
8538 | * but because we are the idle thread, we just pick up running again | |
8539 | * when this runqueue becomes "idle". | |
8540 | */ | |
8541 | init_idle(current, smp_processor_id()); | |
dd41f596 IM |
8542 | /* |
8543 | * During early bootup we pretend to be a normal task: | |
8544 | */ | |
8545 | current->sched_class = &fair_sched_class; | |
6892b75e | 8546 | |
6a7b3dc3 RR |
8547 | /* Allocate the nohz_cpu_mask if CONFIG_CPUMASK_OFFSTACK */ |
8548 | alloc_bootmem_cpumask_var(&nohz_cpu_mask); | |
bf4d83f6 | 8549 | #ifdef CONFIG_SMP |
7d1e6a9b RR |
8550 | #ifdef CONFIG_NO_HZ |
8551 | alloc_bootmem_cpumask_var(&nohz.cpu_mask); | |
8552 | #endif | |
dcc30a35 | 8553 | alloc_bootmem_cpumask_var(&cpu_isolated_map); |
bf4d83f6 | 8554 | #endif /* SMP */ |
6a7b3dc3 | 8555 | |
6892b75e | 8556 | scheduler_running = 1; |
1da177e4 LT |
8557 | } |
8558 | ||
8559 | #ifdef CONFIG_DEBUG_SPINLOCK_SLEEP | |
8560 | void __might_sleep(char *file, int line) | |
8561 | { | |
48f24c4d | 8562 | #ifdef in_atomic |
1da177e4 LT |
8563 | static unsigned long prev_jiffy; /* ratelimiting */ |
8564 | ||
aef745fc IM |
8565 | if ((!in_atomic() && !irqs_disabled()) || |
8566 | system_state != SYSTEM_RUNNING || oops_in_progress) | |
8567 | return; | |
8568 | if (time_before(jiffies, prev_jiffy + HZ) && prev_jiffy) | |
8569 | return; | |
8570 | prev_jiffy = jiffies; | |
8571 | ||
8572 | printk(KERN_ERR | |
8573 | "BUG: sleeping function called from invalid context at %s:%d\n", | |
8574 | file, line); | |
8575 | printk(KERN_ERR | |
8576 | "in_atomic(): %d, irqs_disabled(): %d, pid: %d, name: %s\n", | |
8577 | in_atomic(), irqs_disabled(), | |
8578 | current->pid, current->comm); | |
8579 | ||
8580 | debug_show_held_locks(current); | |
8581 | if (irqs_disabled()) | |
8582 | print_irqtrace_events(current); | |
8583 | dump_stack(); | |
1da177e4 LT |
8584 | #endif |
8585 | } | |
8586 | EXPORT_SYMBOL(__might_sleep); | |
8587 | #endif | |
8588 | ||
8589 | #ifdef CONFIG_MAGIC_SYSRQ | |
3a5e4dc1 AK |
8590 | static void normalize_task(struct rq *rq, struct task_struct *p) |
8591 | { | |
8592 | int on_rq; | |
3e51f33f | 8593 | |
3a5e4dc1 AK |
8594 | update_rq_clock(rq); |
8595 | on_rq = p->se.on_rq; | |
8596 | if (on_rq) | |
8597 | deactivate_task(rq, p, 0); | |
8598 | __setscheduler(rq, p, SCHED_NORMAL, 0); | |
8599 | if (on_rq) { | |
8600 | activate_task(rq, p, 0); | |
8601 | resched_task(rq->curr); | |
8602 | } | |
8603 | } | |
8604 | ||
1da177e4 LT |
8605 | void normalize_rt_tasks(void) |
8606 | { | |
a0f98a1c | 8607 | struct task_struct *g, *p; |
1da177e4 | 8608 | unsigned long flags; |
70b97a7f | 8609 | struct rq *rq; |
1da177e4 | 8610 | |
4cf5d77a | 8611 | read_lock_irqsave(&tasklist_lock, flags); |
a0f98a1c | 8612 | do_each_thread(g, p) { |
178be793 IM |
8613 | /* |
8614 | * Only normalize user tasks: | |
8615 | */ | |
8616 | if (!p->mm) | |
8617 | continue; | |
8618 | ||
6cfb0d5d | 8619 | p->se.exec_start = 0; |
6cfb0d5d | 8620 | #ifdef CONFIG_SCHEDSTATS |
dd41f596 | 8621 | p->se.wait_start = 0; |
dd41f596 | 8622 | p->se.sleep_start = 0; |
dd41f596 | 8623 | p->se.block_start = 0; |
6cfb0d5d | 8624 | #endif |
dd41f596 IM |
8625 | |
8626 | if (!rt_task(p)) { | |
8627 | /* | |
8628 | * Renice negative nice level userspace | |
8629 | * tasks back to 0: | |
8630 | */ | |
8631 | if (TASK_NICE(p) < 0 && p->mm) | |
8632 | set_user_nice(p, 0); | |
1da177e4 | 8633 | continue; |
dd41f596 | 8634 | } |
1da177e4 | 8635 | |
4cf5d77a | 8636 | spin_lock(&p->pi_lock); |
b29739f9 | 8637 | rq = __task_rq_lock(p); |
1da177e4 | 8638 | |
178be793 | 8639 | normalize_task(rq, p); |
3a5e4dc1 | 8640 | |
b29739f9 | 8641 | __task_rq_unlock(rq); |
4cf5d77a | 8642 | spin_unlock(&p->pi_lock); |
a0f98a1c IM |
8643 | } while_each_thread(g, p); |
8644 | ||
4cf5d77a | 8645 | read_unlock_irqrestore(&tasklist_lock, flags); |
1da177e4 LT |
8646 | } |
8647 | ||
8648 | #endif /* CONFIG_MAGIC_SYSRQ */ | |
1df5c10a LT |
8649 | |
8650 | #ifdef CONFIG_IA64 | |
8651 | /* | |
8652 | * These functions are only useful for the IA64 MCA handling. | |
8653 | * | |
8654 | * They can only be called when the whole system has been | |
8655 | * stopped - every CPU needs to be quiescent, and no scheduling | |
8656 | * activity can take place. Using them for anything else would | |
8657 | * be a serious bug, and as a result, they aren't even visible | |
8658 | * under any other configuration. | |
8659 | */ | |
8660 | ||
8661 | /** | |
8662 | * curr_task - return the current task for a given cpu. | |
8663 | * @cpu: the processor in question. | |
8664 | * | |
8665 | * ONLY VALID WHEN THE WHOLE SYSTEM IS STOPPED! | |
8666 | */ | |
36c8b586 | 8667 | struct task_struct *curr_task(int cpu) |
1df5c10a LT |
8668 | { |
8669 | return cpu_curr(cpu); | |
8670 | } | |
8671 | ||
8672 | /** | |
8673 | * set_curr_task - set the current task for a given cpu. | |
8674 | * @cpu: the processor in question. | |
8675 | * @p: the task pointer to set. | |
8676 | * | |
8677 | * Description: This function must only be used when non-maskable interrupts | |
41a2d6cf IM |
8678 | * are serviced on a separate stack. It allows the architecture to switch the |
8679 | * notion of the current task on a cpu in a non-blocking manner. This function | |
1df5c10a LT |
8680 | * must be called with all CPU's synchronized, and interrupts disabled, the |
8681 | * and caller must save the original value of the current task (see | |
8682 | * curr_task() above) and restore that value before reenabling interrupts and | |
8683 | * re-starting the system. | |
8684 | * | |
8685 | * ONLY VALID WHEN THE WHOLE SYSTEM IS STOPPED! | |
8686 | */ | |
36c8b586 | 8687 | void set_curr_task(int cpu, struct task_struct *p) |
1df5c10a LT |
8688 | { |
8689 | cpu_curr(cpu) = p; | |
8690 | } | |
8691 | ||
8692 | #endif | |
29f59db3 | 8693 | |
bccbe08a PZ |
8694 | #ifdef CONFIG_FAIR_GROUP_SCHED |
8695 | static void free_fair_sched_group(struct task_group *tg) | |
6f505b16 PZ |
8696 | { |
8697 | int i; | |
8698 | ||
8699 | for_each_possible_cpu(i) { | |
8700 | if (tg->cfs_rq) | |
8701 | kfree(tg->cfs_rq[i]); | |
8702 | if (tg->se) | |
8703 | kfree(tg->se[i]); | |
6f505b16 PZ |
8704 | } |
8705 | ||
8706 | kfree(tg->cfs_rq); | |
8707 | kfree(tg->se); | |
6f505b16 PZ |
8708 | } |
8709 | ||
ec7dc8ac DG |
8710 | static |
8711 | int alloc_fair_sched_group(struct task_group *tg, struct task_group *parent) | |
29f59db3 | 8712 | { |
29f59db3 | 8713 | struct cfs_rq *cfs_rq; |
eab17229 | 8714 | struct sched_entity *se; |
9b5b7751 | 8715 | struct rq *rq; |
29f59db3 SV |
8716 | int i; |
8717 | ||
434d53b0 | 8718 | tg->cfs_rq = kzalloc(sizeof(cfs_rq) * nr_cpu_ids, GFP_KERNEL); |
29f59db3 SV |
8719 | if (!tg->cfs_rq) |
8720 | goto err; | |
434d53b0 | 8721 | tg->se = kzalloc(sizeof(se) * nr_cpu_ids, GFP_KERNEL); |
29f59db3 SV |
8722 | if (!tg->se) |
8723 | goto err; | |
052f1dc7 PZ |
8724 | |
8725 | tg->shares = NICE_0_LOAD; | |
29f59db3 SV |
8726 | |
8727 | for_each_possible_cpu(i) { | |
9b5b7751 | 8728 | rq = cpu_rq(i); |
29f59db3 | 8729 | |
eab17229 LZ |
8730 | cfs_rq = kzalloc_node(sizeof(struct cfs_rq), |
8731 | GFP_KERNEL, cpu_to_node(i)); | |
29f59db3 SV |
8732 | if (!cfs_rq) |
8733 | goto err; | |
8734 | ||
eab17229 LZ |
8735 | se = kzalloc_node(sizeof(struct sched_entity), |
8736 | GFP_KERNEL, cpu_to_node(i)); | |
29f59db3 SV |
8737 | if (!se) |
8738 | goto err; | |
8739 | ||
eab17229 | 8740 | init_tg_cfs_entry(tg, cfs_rq, se, i, 0, parent->se[i]); |
bccbe08a PZ |
8741 | } |
8742 | ||
8743 | return 1; | |
8744 | ||
8745 | err: | |
8746 | return 0; | |
8747 | } | |
8748 | ||
8749 | static inline void register_fair_sched_group(struct task_group *tg, int cpu) | |
8750 | { | |
8751 | list_add_rcu(&tg->cfs_rq[cpu]->leaf_cfs_rq_list, | |
8752 | &cpu_rq(cpu)->leaf_cfs_rq_list); | |
8753 | } | |
8754 | ||
8755 | static inline void unregister_fair_sched_group(struct task_group *tg, int cpu) | |
8756 | { | |
8757 | list_del_rcu(&tg->cfs_rq[cpu]->leaf_cfs_rq_list); | |
8758 | } | |
6d6bc0ad | 8759 | #else /* !CONFG_FAIR_GROUP_SCHED */ |
bccbe08a PZ |
8760 | static inline void free_fair_sched_group(struct task_group *tg) |
8761 | { | |
8762 | } | |
8763 | ||
ec7dc8ac DG |
8764 | static inline |
8765 | int alloc_fair_sched_group(struct task_group *tg, struct task_group *parent) | |
bccbe08a PZ |
8766 | { |
8767 | return 1; | |
8768 | } | |
8769 | ||
8770 | static inline void register_fair_sched_group(struct task_group *tg, int cpu) | |
8771 | { | |
8772 | } | |
8773 | ||
8774 | static inline void unregister_fair_sched_group(struct task_group *tg, int cpu) | |
8775 | { | |
8776 | } | |
6d6bc0ad | 8777 | #endif /* CONFIG_FAIR_GROUP_SCHED */ |
052f1dc7 PZ |
8778 | |
8779 | #ifdef CONFIG_RT_GROUP_SCHED | |
bccbe08a PZ |
8780 | static void free_rt_sched_group(struct task_group *tg) |
8781 | { | |
8782 | int i; | |
8783 | ||
d0b27fa7 PZ |
8784 | destroy_rt_bandwidth(&tg->rt_bandwidth); |
8785 | ||
bccbe08a PZ |
8786 | for_each_possible_cpu(i) { |
8787 | if (tg->rt_rq) | |
8788 | kfree(tg->rt_rq[i]); | |
8789 | if (tg->rt_se) | |
8790 | kfree(tg->rt_se[i]); | |
8791 | } | |
8792 | ||
8793 | kfree(tg->rt_rq); | |
8794 | kfree(tg->rt_se); | |
8795 | } | |
8796 | ||
ec7dc8ac DG |
8797 | static |
8798 | int alloc_rt_sched_group(struct task_group *tg, struct task_group *parent) | |
bccbe08a PZ |
8799 | { |
8800 | struct rt_rq *rt_rq; | |
eab17229 | 8801 | struct sched_rt_entity *rt_se; |
bccbe08a PZ |
8802 | struct rq *rq; |
8803 | int i; | |
8804 | ||
434d53b0 | 8805 | tg->rt_rq = kzalloc(sizeof(rt_rq) * nr_cpu_ids, GFP_KERNEL); |
bccbe08a PZ |
8806 | if (!tg->rt_rq) |
8807 | goto err; | |
434d53b0 | 8808 | tg->rt_se = kzalloc(sizeof(rt_se) * nr_cpu_ids, GFP_KERNEL); |
bccbe08a PZ |
8809 | if (!tg->rt_se) |
8810 | goto err; | |
8811 | ||
d0b27fa7 PZ |
8812 | init_rt_bandwidth(&tg->rt_bandwidth, |
8813 | ktime_to_ns(def_rt_bandwidth.rt_period), 0); | |
bccbe08a PZ |
8814 | |
8815 | for_each_possible_cpu(i) { | |
8816 | rq = cpu_rq(i); | |
8817 | ||
eab17229 LZ |
8818 | rt_rq = kzalloc_node(sizeof(struct rt_rq), |
8819 | GFP_KERNEL, cpu_to_node(i)); | |
6f505b16 PZ |
8820 | if (!rt_rq) |
8821 | goto err; | |
29f59db3 | 8822 | |
eab17229 LZ |
8823 | rt_se = kzalloc_node(sizeof(struct sched_rt_entity), |
8824 | GFP_KERNEL, cpu_to_node(i)); | |
6f505b16 PZ |
8825 | if (!rt_se) |
8826 | goto err; | |
29f59db3 | 8827 | |
eab17229 | 8828 | init_tg_rt_entry(tg, rt_rq, rt_se, i, 0, parent->rt_se[i]); |
29f59db3 SV |
8829 | } |
8830 | ||
bccbe08a PZ |
8831 | return 1; |
8832 | ||
8833 | err: | |
8834 | return 0; | |
8835 | } | |
8836 | ||
8837 | static inline void register_rt_sched_group(struct task_group *tg, int cpu) | |
8838 | { | |
8839 | list_add_rcu(&tg->rt_rq[cpu]->leaf_rt_rq_list, | |
8840 | &cpu_rq(cpu)->leaf_rt_rq_list); | |
8841 | } | |
8842 | ||
8843 | static inline void unregister_rt_sched_group(struct task_group *tg, int cpu) | |
8844 | { | |
8845 | list_del_rcu(&tg->rt_rq[cpu]->leaf_rt_rq_list); | |
8846 | } | |
6d6bc0ad | 8847 | #else /* !CONFIG_RT_GROUP_SCHED */ |
bccbe08a PZ |
8848 | static inline void free_rt_sched_group(struct task_group *tg) |
8849 | { | |
8850 | } | |
8851 | ||
ec7dc8ac DG |
8852 | static inline |
8853 | int alloc_rt_sched_group(struct task_group *tg, struct task_group *parent) | |
bccbe08a PZ |
8854 | { |
8855 | return 1; | |
8856 | } | |
8857 | ||
8858 | static inline void register_rt_sched_group(struct task_group *tg, int cpu) | |
8859 | { | |
8860 | } | |
8861 | ||
8862 | static inline void unregister_rt_sched_group(struct task_group *tg, int cpu) | |
8863 | { | |
8864 | } | |
6d6bc0ad | 8865 | #endif /* CONFIG_RT_GROUP_SCHED */ |
bccbe08a | 8866 | |
d0b27fa7 | 8867 | #ifdef CONFIG_GROUP_SCHED |
bccbe08a PZ |
8868 | static void free_sched_group(struct task_group *tg) |
8869 | { | |
8870 | free_fair_sched_group(tg); | |
8871 | free_rt_sched_group(tg); | |
8872 | kfree(tg); | |
8873 | } | |
8874 | ||
8875 | /* allocate runqueue etc for a new task group */ | |
ec7dc8ac | 8876 | struct task_group *sched_create_group(struct task_group *parent) |
bccbe08a PZ |
8877 | { |
8878 | struct task_group *tg; | |
8879 | unsigned long flags; | |
8880 | int i; | |
8881 | ||
8882 | tg = kzalloc(sizeof(*tg), GFP_KERNEL); | |
8883 | if (!tg) | |
8884 | return ERR_PTR(-ENOMEM); | |
8885 | ||
ec7dc8ac | 8886 | if (!alloc_fair_sched_group(tg, parent)) |
bccbe08a PZ |
8887 | goto err; |
8888 | ||
ec7dc8ac | 8889 | if (!alloc_rt_sched_group(tg, parent)) |
bccbe08a PZ |
8890 | goto err; |
8891 | ||
8ed36996 | 8892 | spin_lock_irqsave(&task_group_lock, flags); |
9b5b7751 | 8893 | for_each_possible_cpu(i) { |
bccbe08a PZ |
8894 | register_fair_sched_group(tg, i); |
8895 | register_rt_sched_group(tg, i); | |
9b5b7751 | 8896 | } |
6f505b16 | 8897 | list_add_rcu(&tg->list, &task_groups); |
f473aa5e PZ |
8898 | |
8899 | WARN_ON(!parent); /* root should already exist */ | |
8900 | ||
8901 | tg->parent = parent; | |
f473aa5e | 8902 | INIT_LIST_HEAD(&tg->children); |
09f2724a | 8903 | list_add_rcu(&tg->siblings, &parent->children); |
8ed36996 | 8904 | spin_unlock_irqrestore(&task_group_lock, flags); |
29f59db3 | 8905 | |
9b5b7751 | 8906 | return tg; |
29f59db3 SV |
8907 | |
8908 | err: | |
6f505b16 | 8909 | free_sched_group(tg); |
29f59db3 SV |
8910 | return ERR_PTR(-ENOMEM); |
8911 | } | |
8912 | ||
9b5b7751 | 8913 | /* rcu callback to free various structures associated with a task group */ |
6f505b16 | 8914 | static void free_sched_group_rcu(struct rcu_head *rhp) |
29f59db3 | 8915 | { |
29f59db3 | 8916 | /* now it should be safe to free those cfs_rqs */ |
6f505b16 | 8917 | free_sched_group(container_of(rhp, struct task_group, rcu)); |
29f59db3 SV |
8918 | } |
8919 | ||
9b5b7751 | 8920 | /* Destroy runqueue etc associated with a task group */ |
4cf86d77 | 8921 | void sched_destroy_group(struct task_group *tg) |
29f59db3 | 8922 | { |
8ed36996 | 8923 | unsigned long flags; |
9b5b7751 | 8924 | int i; |
29f59db3 | 8925 | |
8ed36996 | 8926 | spin_lock_irqsave(&task_group_lock, flags); |
9b5b7751 | 8927 | for_each_possible_cpu(i) { |
bccbe08a PZ |
8928 | unregister_fair_sched_group(tg, i); |
8929 | unregister_rt_sched_group(tg, i); | |
9b5b7751 | 8930 | } |
6f505b16 | 8931 | list_del_rcu(&tg->list); |
f473aa5e | 8932 | list_del_rcu(&tg->siblings); |
8ed36996 | 8933 | spin_unlock_irqrestore(&task_group_lock, flags); |
9b5b7751 | 8934 | |
9b5b7751 | 8935 | /* wait for possible concurrent references to cfs_rqs complete */ |
6f505b16 | 8936 | call_rcu(&tg->rcu, free_sched_group_rcu); |
29f59db3 SV |
8937 | } |
8938 | ||
9b5b7751 | 8939 | /* change task's runqueue when it moves between groups. |
3a252015 IM |
8940 | * The caller of this function should have put the task in its new group |
8941 | * by now. This function just updates tsk->se.cfs_rq and tsk->se.parent to | |
8942 | * reflect its new group. | |
9b5b7751 SV |
8943 | */ |
8944 | void sched_move_task(struct task_struct *tsk) | |
29f59db3 SV |
8945 | { |
8946 | int on_rq, running; | |
8947 | unsigned long flags; | |
8948 | struct rq *rq; | |
8949 | ||
8950 | rq = task_rq_lock(tsk, &flags); | |
8951 | ||
29f59db3 SV |
8952 | update_rq_clock(rq); |
8953 | ||
051a1d1a | 8954 | running = task_current(rq, tsk); |
29f59db3 SV |
8955 | on_rq = tsk->se.on_rq; |
8956 | ||
0e1f3483 | 8957 | if (on_rq) |
29f59db3 | 8958 | dequeue_task(rq, tsk, 0); |
0e1f3483 HS |
8959 | if (unlikely(running)) |
8960 | tsk->sched_class->put_prev_task(rq, tsk); | |
29f59db3 | 8961 | |
6f505b16 | 8962 | set_task_rq(tsk, task_cpu(tsk)); |
29f59db3 | 8963 | |
810b3817 PZ |
8964 | #ifdef CONFIG_FAIR_GROUP_SCHED |
8965 | if (tsk->sched_class->moved_group) | |
8966 | tsk->sched_class->moved_group(tsk); | |
8967 | #endif | |
8968 | ||
0e1f3483 HS |
8969 | if (unlikely(running)) |
8970 | tsk->sched_class->set_curr_task(rq); | |
8971 | if (on_rq) | |
7074badb | 8972 | enqueue_task(rq, tsk, 0); |
29f59db3 | 8973 | |
29f59db3 SV |
8974 | task_rq_unlock(rq, &flags); |
8975 | } | |
6d6bc0ad | 8976 | #endif /* CONFIG_GROUP_SCHED */ |
29f59db3 | 8977 | |
052f1dc7 | 8978 | #ifdef CONFIG_FAIR_GROUP_SCHED |
c09595f6 | 8979 | static void __set_se_shares(struct sched_entity *se, unsigned long shares) |
29f59db3 SV |
8980 | { |
8981 | struct cfs_rq *cfs_rq = se->cfs_rq; | |
29f59db3 SV |
8982 | int on_rq; |
8983 | ||
29f59db3 | 8984 | on_rq = se->on_rq; |
62fb1851 | 8985 | if (on_rq) |
29f59db3 SV |
8986 | dequeue_entity(cfs_rq, se, 0); |
8987 | ||
8988 | se->load.weight = shares; | |
e05510d0 | 8989 | se->load.inv_weight = 0; |
29f59db3 | 8990 | |
62fb1851 | 8991 | if (on_rq) |
29f59db3 | 8992 | enqueue_entity(cfs_rq, se, 0); |
c09595f6 | 8993 | } |
62fb1851 | 8994 | |
c09595f6 PZ |
8995 | static void set_se_shares(struct sched_entity *se, unsigned long shares) |
8996 | { | |
8997 | struct cfs_rq *cfs_rq = se->cfs_rq; | |
8998 | struct rq *rq = cfs_rq->rq; | |
8999 | unsigned long flags; | |
9000 | ||
9001 | spin_lock_irqsave(&rq->lock, flags); | |
9002 | __set_se_shares(se, shares); | |
9003 | spin_unlock_irqrestore(&rq->lock, flags); | |
29f59db3 SV |
9004 | } |
9005 | ||
8ed36996 PZ |
9006 | static DEFINE_MUTEX(shares_mutex); |
9007 | ||
4cf86d77 | 9008 | int sched_group_set_shares(struct task_group *tg, unsigned long shares) |
29f59db3 SV |
9009 | { |
9010 | int i; | |
8ed36996 | 9011 | unsigned long flags; |
c61935fd | 9012 | |
ec7dc8ac DG |
9013 | /* |
9014 | * We can't change the weight of the root cgroup. | |
9015 | */ | |
9016 | if (!tg->se[0]) | |
9017 | return -EINVAL; | |
9018 | ||
18d95a28 PZ |
9019 | if (shares < MIN_SHARES) |
9020 | shares = MIN_SHARES; | |
cb4ad1ff MX |
9021 | else if (shares > MAX_SHARES) |
9022 | shares = MAX_SHARES; | |
62fb1851 | 9023 | |
8ed36996 | 9024 | mutex_lock(&shares_mutex); |
9b5b7751 | 9025 | if (tg->shares == shares) |
5cb350ba | 9026 | goto done; |
29f59db3 | 9027 | |
8ed36996 | 9028 | spin_lock_irqsave(&task_group_lock, flags); |
bccbe08a PZ |
9029 | for_each_possible_cpu(i) |
9030 | unregister_fair_sched_group(tg, i); | |
f473aa5e | 9031 | list_del_rcu(&tg->siblings); |
8ed36996 | 9032 | spin_unlock_irqrestore(&task_group_lock, flags); |
6b2d7700 SV |
9033 | |
9034 | /* wait for any ongoing reference to this group to finish */ | |
9035 | synchronize_sched(); | |
9036 | ||
9037 | /* | |
9038 | * Now we are free to modify the group's share on each cpu | |
9039 | * w/o tripping rebalance_share or load_balance_fair. | |
9040 | */ | |
9b5b7751 | 9041 | tg->shares = shares; |
c09595f6 PZ |
9042 | for_each_possible_cpu(i) { |
9043 | /* | |
9044 | * force a rebalance | |
9045 | */ | |
9046 | cfs_rq_set_shares(tg->cfs_rq[i], 0); | |
cb4ad1ff | 9047 | set_se_shares(tg->se[i], shares); |
c09595f6 | 9048 | } |
29f59db3 | 9049 | |
6b2d7700 SV |
9050 | /* |
9051 | * Enable load balance activity on this group, by inserting it back on | |
9052 | * each cpu's rq->leaf_cfs_rq_list. | |
9053 | */ | |
8ed36996 | 9054 | spin_lock_irqsave(&task_group_lock, flags); |
bccbe08a PZ |
9055 | for_each_possible_cpu(i) |
9056 | register_fair_sched_group(tg, i); | |
f473aa5e | 9057 | list_add_rcu(&tg->siblings, &tg->parent->children); |
8ed36996 | 9058 | spin_unlock_irqrestore(&task_group_lock, flags); |
5cb350ba | 9059 | done: |
8ed36996 | 9060 | mutex_unlock(&shares_mutex); |
9b5b7751 | 9061 | return 0; |
29f59db3 SV |
9062 | } |
9063 | ||
5cb350ba DG |
9064 | unsigned long sched_group_shares(struct task_group *tg) |
9065 | { | |
9066 | return tg->shares; | |
9067 | } | |
052f1dc7 | 9068 | #endif |
5cb350ba | 9069 | |
052f1dc7 | 9070 | #ifdef CONFIG_RT_GROUP_SCHED |
6f505b16 | 9071 | /* |
9f0c1e56 | 9072 | * Ensure that the real time constraints are schedulable. |
6f505b16 | 9073 | */ |
9f0c1e56 PZ |
9074 | static DEFINE_MUTEX(rt_constraints_mutex); |
9075 | ||
9076 | static unsigned long to_ratio(u64 period, u64 runtime) | |
9077 | { | |
9078 | if (runtime == RUNTIME_INF) | |
9a7e0b18 | 9079 | return 1ULL << 20; |
9f0c1e56 | 9080 | |
9a7e0b18 | 9081 | return div64_u64(runtime << 20, period); |
9f0c1e56 PZ |
9082 | } |
9083 | ||
9a7e0b18 PZ |
9084 | /* Must be called with tasklist_lock held */ |
9085 | static inline int tg_has_rt_tasks(struct task_group *tg) | |
b40b2e8e | 9086 | { |
9a7e0b18 | 9087 | struct task_struct *g, *p; |
b40b2e8e | 9088 | |
9a7e0b18 PZ |
9089 | do_each_thread(g, p) { |
9090 | if (rt_task(p) && rt_rq_of_se(&p->rt)->tg == tg) | |
9091 | return 1; | |
9092 | } while_each_thread(g, p); | |
b40b2e8e | 9093 | |
9a7e0b18 PZ |
9094 | return 0; |
9095 | } | |
b40b2e8e | 9096 | |
9a7e0b18 PZ |
9097 | struct rt_schedulable_data { |
9098 | struct task_group *tg; | |
9099 | u64 rt_period; | |
9100 | u64 rt_runtime; | |
9101 | }; | |
b40b2e8e | 9102 | |
9a7e0b18 PZ |
9103 | static int tg_schedulable(struct task_group *tg, void *data) |
9104 | { | |
9105 | struct rt_schedulable_data *d = data; | |
9106 | struct task_group *child; | |
9107 | unsigned long total, sum = 0; | |
9108 | u64 period, runtime; | |
b40b2e8e | 9109 | |
9a7e0b18 PZ |
9110 | period = ktime_to_ns(tg->rt_bandwidth.rt_period); |
9111 | runtime = tg->rt_bandwidth.rt_runtime; | |
b40b2e8e | 9112 | |
9a7e0b18 PZ |
9113 | if (tg == d->tg) { |
9114 | period = d->rt_period; | |
9115 | runtime = d->rt_runtime; | |
b40b2e8e | 9116 | } |
b40b2e8e | 9117 | |
98a4826b PZ |
9118 | #ifdef CONFIG_USER_SCHED |
9119 | if (tg == &root_task_group) { | |
9120 | period = global_rt_period(); | |
9121 | runtime = global_rt_runtime(); | |
9122 | } | |
9123 | #endif | |
9124 | ||
4653f803 PZ |
9125 | /* |
9126 | * Cannot have more runtime than the period. | |
9127 | */ | |
9128 | if (runtime > period && runtime != RUNTIME_INF) | |
9129 | return -EINVAL; | |
6f505b16 | 9130 | |
4653f803 PZ |
9131 | /* |
9132 | * Ensure we don't starve existing RT tasks. | |
9133 | */ | |
9a7e0b18 PZ |
9134 | if (rt_bandwidth_enabled() && !runtime && tg_has_rt_tasks(tg)) |
9135 | return -EBUSY; | |
6f505b16 | 9136 | |
9a7e0b18 | 9137 | total = to_ratio(period, runtime); |
6f505b16 | 9138 | |
4653f803 PZ |
9139 | /* |
9140 | * Nobody can have more than the global setting allows. | |
9141 | */ | |
9142 | if (total > to_ratio(global_rt_period(), global_rt_runtime())) | |
9143 | return -EINVAL; | |
6f505b16 | 9144 | |
4653f803 PZ |
9145 | /* |
9146 | * The sum of our children's runtime should not exceed our own. | |
9147 | */ | |
9a7e0b18 PZ |
9148 | list_for_each_entry_rcu(child, &tg->children, siblings) { |
9149 | period = ktime_to_ns(child->rt_bandwidth.rt_period); | |
9150 | runtime = child->rt_bandwidth.rt_runtime; | |
6f505b16 | 9151 | |
9a7e0b18 PZ |
9152 | if (child == d->tg) { |
9153 | period = d->rt_period; | |
9154 | runtime = d->rt_runtime; | |
9155 | } | |
6f505b16 | 9156 | |
9a7e0b18 | 9157 | sum += to_ratio(period, runtime); |
9f0c1e56 | 9158 | } |
6f505b16 | 9159 | |
9a7e0b18 PZ |
9160 | if (sum > total) |
9161 | return -EINVAL; | |
9162 | ||
9163 | return 0; | |
6f505b16 PZ |
9164 | } |
9165 | ||
9a7e0b18 | 9166 | static int __rt_schedulable(struct task_group *tg, u64 period, u64 runtime) |
521f1a24 | 9167 | { |
9a7e0b18 PZ |
9168 | struct rt_schedulable_data data = { |
9169 | .tg = tg, | |
9170 | .rt_period = period, | |
9171 | .rt_runtime = runtime, | |
9172 | }; | |
9173 | ||
9174 | return walk_tg_tree(tg_schedulable, tg_nop, &data); | |
521f1a24 DG |
9175 | } |
9176 | ||
d0b27fa7 PZ |
9177 | static int tg_set_bandwidth(struct task_group *tg, |
9178 | u64 rt_period, u64 rt_runtime) | |
6f505b16 | 9179 | { |
ac086bc2 | 9180 | int i, err = 0; |
9f0c1e56 | 9181 | |
9f0c1e56 | 9182 | mutex_lock(&rt_constraints_mutex); |
521f1a24 | 9183 | read_lock(&tasklist_lock); |
9a7e0b18 PZ |
9184 | err = __rt_schedulable(tg, rt_period, rt_runtime); |
9185 | if (err) | |
9f0c1e56 | 9186 | goto unlock; |
ac086bc2 PZ |
9187 | |
9188 | spin_lock_irq(&tg->rt_bandwidth.rt_runtime_lock); | |
d0b27fa7 PZ |
9189 | tg->rt_bandwidth.rt_period = ns_to_ktime(rt_period); |
9190 | tg->rt_bandwidth.rt_runtime = rt_runtime; | |
ac086bc2 PZ |
9191 | |
9192 | for_each_possible_cpu(i) { | |
9193 | struct rt_rq *rt_rq = tg->rt_rq[i]; | |
9194 | ||
9195 | spin_lock(&rt_rq->rt_runtime_lock); | |
9196 | rt_rq->rt_runtime = rt_runtime; | |
9197 | spin_unlock(&rt_rq->rt_runtime_lock); | |
9198 | } | |
9199 | spin_unlock_irq(&tg->rt_bandwidth.rt_runtime_lock); | |
9f0c1e56 | 9200 | unlock: |
521f1a24 | 9201 | read_unlock(&tasklist_lock); |
9f0c1e56 PZ |
9202 | mutex_unlock(&rt_constraints_mutex); |
9203 | ||
9204 | return err; | |
6f505b16 PZ |
9205 | } |
9206 | ||
d0b27fa7 PZ |
9207 | int sched_group_set_rt_runtime(struct task_group *tg, long rt_runtime_us) |
9208 | { | |
9209 | u64 rt_runtime, rt_period; | |
9210 | ||
9211 | rt_period = ktime_to_ns(tg->rt_bandwidth.rt_period); | |
9212 | rt_runtime = (u64)rt_runtime_us * NSEC_PER_USEC; | |
9213 | if (rt_runtime_us < 0) | |
9214 | rt_runtime = RUNTIME_INF; | |
9215 | ||
9216 | return tg_set_bandwidth(tg, rt_period, rt_runtime); | |
9217 | } | |
9218 | ||
9f0c1e56 PZ |
9219 | long sched_group_rt_runtime(struct task_group *tg) |
9220 | { | |
9221 | u64 rt_runtime_us; | |
9222 | ||
d0b27fa7 | 9223 | if (tg->rt_bandwidth.rt_runtime == RUNTIME_INF) |
9f0c1e56 PZ |
9224 | return -1; |
9225 | ||
d0b27fa7 | 9226 | rt_runtime_us = tg->rt_bandwidth.rt_runtime; |
9f0c1e56 PZ |
9227 | do_div(rt_runtime_us, NSEC_PER_USEC); |
9228 | return rt_runtime_us; | |
9229 | } | |
d0b27fa7 PZ |
9230 | |
9231 | int sched_group_set_rt_period(struct task_group *tg, long rt_period_us) | |
9232 | { | |
9233 | u64 rt_runtime, rt_period; | |
9234 | ||
9235 | rt_period = (u64)rt_period_us * NSEC_PER_USEC; | |
9236 | rt_runtime = tg->rt_bandwidth.rt_runtime; | |
9237 | ||
619b0488 R |
9238 | if (rt_period == 0) |
9239 | return -EINVAL; | |
9240 | ||
d0b27fa7 PZ |
9241 | return tg_set_bandwidth(tg, rt_period, rt_runtime); |
9242 | } | |
9243 | ||
9244 | long sched_group_rt_period(struct task_group *tg) | |
9245 | { | |
9246 | u64 rt_period_us; | |
9247 | ||
9248 | rt_period_us = ktime_to_ns(tg->rt_bandwidth.rt_period); | |
9249 | do_div(rt_period_us, NSEC_PER_USEC); | |
9250 | return rt_period_us; | |
9251 | } | |
9252 | ||
9253 | static int sched_rt_global_constraints(void) | |
9254 | { | |
4653f803 | 9255 | u64 runtime, period; |
d0b27fa7 PZ |
9256 | int ret = 0; |
9257 | ||
ec5d4989 HS |
9258 | if (sysctl_sched_rt_period <= 0) |
9259 | return -EINVAL; | |
9260 | ||
4653f803 PZ |
9261 | runtime = global_rt_runtime(); |
9262 | period = global_rt_period(); | |
9263 | ||
9264 | /* | |
9265 | * Sanity check on the sysctl variables. | |
9266 | */ | |
9267 | if (runtime > period && runtime != RUNTIME_INF) | |
9268 | return -EINVAL; | |
10b612f4 | 9269 | |
d0b27fa7 | 9270 | mutex_lock(&rt_constraints_mutex); |
9a7e0b18 | 9271 | read_lock(&tasklist_lock); |
4653f803 | 9272 | ret = __rt_schedulable(NULL, 0, 0); |
9a7e0b18 | 9273 | read_unlock(&tasklist_lock); |
d0b27fa7 PZ |
9274 | mutex_unlock(&rt_constraints_mutex); |
9275 | ||
9276 | return ret; | |
9277 | } | |
6d6bc0ad | 9278 | #else /* !CONFIG_RT_GROUP_SCHED */ |
d0b27fa7 PZ |
9279 | static int sched_rt_global_constraints(void) |
9280 | { | |
ac086bc2 PZ |
9281 | unsigned long flags; |
9282 | int i; | |
9283 | ||
ec5d4989 HS |
9284 | if (sysctl_sched_rt_period <= 0) |
9285 | return -EINVAL; | |
9286 | ||
ac086bc2 PZ |
9287 | spin_lock_irqsave(&def_rt_bandwidth.rt_runtime_lock, flags); |
9288 | for_each_possible_cpu(i) { | |
9289 | struct rt_rq *rt_rq = &cpu_rq(i)->rt; | |
9290 | ||
9291 | spin_lock(&rt_rq->rt_runtime_lock); | |
9292 | rt_rq->rt_runtime = global_rt_runtime(); | |
9293 | spin_unlock(&rt_rq->rt_runtime_lock); | |
9294 | } | |
9295 | spin_unlock_irqrestore(&def_rt_bandwidth.rt_runtime_lock, flags); | |
9296 | ||
d0b27fa7 PZ |
9297 | return 0; |
9298 | } | |
6d6bc0ad | 9299 | #endif /* CONFIG_RT_GROUP_SCHED */ |
d0b27fa7 PZ |
9300 | |
9301 | int sched_rt_handler(struct ctl_table *table, int write, | |
9302 | struct file *filp, void __user *buffer, size_t *lenp, | |
9303 | loff_t *ppos) | |
9304 | { | |
9305 | int ret; | |
9306 | int old_period, old_runtime; | |
9307 | static DEFINE_MUTEX(mutex); | |
9308 | ||
9309 | mutex_lock(&mutex); | |
9310 | old_period = sysctl_sched_rt_period; | |
9311 | old_runtime = sysctl_sched_rt_runtime; | |
9312 | ||
9313 | ret = proc_dointvec(table, write, filp, buffer, lenp, ppos); | |
9314 | ||
9315 | if (!ret && write) { | |
9316 | ret = sched_rt_global_constraints(); | |
9317 | if (ret) { | |
9318 | sysctl_sched_rt_period = old_period; | |
9319 | sysctl_sched_rt_runtime = old_runtime; | |
9320 | } else { | |
9321 | def_rt_bandwidth.rt_runtime = global_rt_runtime(); | |
9322 | def_rt_bandwidth.rt_period = | |
9323 | ns_to_ktime(global_rt_period()); | |
9324 | } | |
9325 | } | |
9326 | mutex_unlock(&mutex); | |
9327 | ||
9328 | return ret; | |
9329 | } | |
68318b8e | 9330 | |
052f1dc7 | 9331 | #ifdef CONFIG_CGROUP_SCHED |
68318b8e SV |
9332 | |
9333 | /* return corresponding task_group object of a cgroup */ | |
2b01dfe3 | 9334 | static inline struct task_group *cgroup_tg(struct cgroup *cgrp) |
68318b8e | 9335 | { |
2b01dfe3 PM |
9336 | return container_of(cgroup_subsys_state(cgrp, cpu_cgroup_subsys_id), |
9337 | struct task_group, css); | |
68318b8e SV |
9338 | } |
9339 | ||
9340 | static struct cgroup_subsys_state * | |
2b01dfe3 | 9341 | cpu_cgroup_create(struct cgroup_subsys *ss, struct cgroup *cgrp) |
68318b8e | 9342 | { |
ec7dc8ac | 9343 | struct task_group *tg, *parent; |
68318b8e | 9344 | |
2b01dfe3 | 9345 | if (!cgrp->parent) { |
68318b8e | 9346 | /* This is early initialization for the top cgroup */ |
68318b8e SV |
9347 | return &init_task_group.css; |
9348 | } | |
9349 | ||
ec7dc8ac DG |
9350 | parent = cgroup_tg(cgrp->parent); |
9351 | tg = sched_create_group(parent); | |
68318b8e SV |
9352 | if (IS_ERR(tg)) |
9353 | return ERR_PTR(-ENOMEM); | |
9354 | ||
68318b8e SV |
9355 | return &tg->css; |
9356 | } | |
9357 | ||
41a2d6cf IM |
9358 | static void |
9359 | cpu_cgroup_destroy(struct cgroup_subsys *ss, struct cgroup *cgrp) | |
68318b8e | 9360 | { |
2b01dfe3 | 9361 | struct task_group *tg = cgroup_tg(cgrp); |
68318b8e SV |
9362 | |
9363 | sched_destroy_group(tg); | |
9364 | } | |
9365 | ||
41a2d6cf IM |
9366 | static int |
9367 | cpu_cgroup_can_attach(struct cgroup_subsys *ss, struct cgroup *cgrp, | |
9368 | struct task_struct *tsk) | |
68318b8e | 9369 | { |
b68aa230 PZ |
9370 | #ifdef CONFIG_RT_GROUP_SCHED |
9371 | /* Don't accept realtime tasks when there is no way for them to run */ | |
d0b27fa7 | 9372 | if (rt_task(tsk) && cgroup_tg(cgrp)->rt_bandwidth.rt_runtime == 0) |
b68aa230 PZ |
9373 | return -EINVAL; |
9374 | #else | |
68318b8e SV |
9375 | /* We don't support RT-tasks being in separate groups */ |
9376 | if (tsk->sched_class != &fair_sched_class) | |
9377 | return -EINVAL; | |
b68aa230 | 9378 | #endif |
68318b8e SV |
9379 | |
9380 | return 0; | |
9381 | } | |
9382 | ||
9383 | static void | |
2b01dfe3 | 9384 | cpu_cgroup_attach(struct cgroup_subsys *ss, struct cgroup *cgrp, |
68318b8e SV |
9385 | struct cgroup *old_cont, struct task_struct *tsk) |
9386 | { | |
9387 | sched_move_task(tsk); | |
9388 | } | |
9389 | ||
052f1dc7 | 9390 | #ifdef CONFIG_FAIR_GROUP_SCHED |
f4c753b7 | 9391 | static int cpu_shares_write_u64(struct cgroup *cgrp, struct cftype *cftype, |
2b01dfe3 | 9392 | u64 shareval) |
68318b8e | 9393 | { |
2b01dfe3 | 9394 | return sched_group_set_shares(cgroup_tg(cgrp), shareval); |
68318b8e SV |
9395 | } |
9396 | ||
f4c753b7 | 9397 | static u64 cpu_shares_read_u64(struct cgroup *cgrp, struct cftype *cft) |
68318b8e | 9398 | { |
2b01dfe3 | 9399 | struct task_group *tg = cgroup_tg(cgrp); |
68318b8e SV |
9400 | |
9401 | return (u64) tg->shares; | |
9402 | } | |
6d6bc0ad | 9403 | #endif /* CONFIG_FAIR_GROUP_SCHED */ |
68318b8e | 9404 | |
052f1dc7 | 9405 | #ifdef CONFIG_RT_GROUP_SCHED |
0c70814c | 9406 | static int cpu_rt_runtime_write(struct cgroup *cgrp, struct cftype *cft, |
06ecb27c | 9407 | s64 val) |
6f505b16 | 9408 | { |
06ecb27c | 9409 | return sched_group_set_rt_runtime(cgroup_tg(cgrp), val); |
6f505b16 PZ |
9410 | } |
9411 | ||
06ecb27c | 9412 | static s64 cpu_rt_runtime_read(struct cgroup *cgrp, struct cftype *cft) |
6f505b16 | 9413 | { |
06ecb27c | 9414 | return sched_group_rt_runtime(cgroup_tg(cgrp)); |
6f505b16 | 9415 | } |
d0b27fa7 PZ |
9416 | |
9417 | static int cpu_rt_period_write_uint(struct cgroup *cgrp, struct cftype *cftype, | |
9418 | u64 rt_period_us) | |
9419 | { | |
9420 | return sched_group_set_rt_period(cgroup_tg(cgrp), rt_period_us); | |
9421 | } | |
9422 | ||
9423 | static u64 cpu_rt_period_read_uint(struct cgroup *cgrp, struct cftype *cft) | |
9424 | { | |
9425 | return sched_group_rt_period(cgroup_tg(cgrp)); | |
9426 | } | |
6d6bc0ad | 9427 | #endif /* CONFIG_RT_GROUP_SCHED */ |
6f505b16 | 9428 | |
fe5c7cc2 | 9429 | static struct cftype cpu_files[] = { |
052f1dc7 | 9430 | #ifdef CONFIG_FAIR_GROUP_SCHED |
fe5c7cc2 PM |
9431 | { |
9432 | .name = "shares", | |
f4c753b7 PM |
9433 | .read_u64 = cpu_shares_read_u64, |
9434 | .write_u64 = cpu_shares_write_u64, | |
fe5c7cc2 | 9435 | }, |
052f1dc7 PZ |
9436 | #endif |
9437 | #ifdef CONFIG_RT_GROUP_SCHED | |
6f505b16 | 9438 | { |
9f0c1e56 | 9439 | .name = "rt_runtime_us", |
06ecb27c PM |
9440 | .read_s64 = cpu_rt_runtime_read, |
9441 | .write_s64 = cpu_rt_runtime_write, | |
6f505b16 | 9442 | }, |
d0b27fa7 PZ |
9443 | { |
9444 | .name = "rt_period_us", | |
f4c753b7 PM |
9445 | .read_u64 = cpu_rt_period_read_uint, |
9446 | .write_u64 = cpu_rt_period_write_uint, | |
d0b27fa7 | 9447 | }, |
052f1dc7 | 9448 | #endif |
68318b8e SV |
9449 | }; |
9450 | ||
9451 | static int cpu_cgroup_populate(struct cgroup_subsys *ss, struct cgroup *cont) | |
9452 | { | |
fe5c7cc2 | 9453 | return cgroup_add_files(cont, ss, cpu_files, ARRAY_SIZE(cpu_files)); |
68318b8e SV |
9454 | } |
9455 | ||
9456 | struct cgroup_subsys cpu_cgroup_subsys = { | |
38605cae IM |
9457 | .name = "cpu", |
9458 | .create = cpu_cgroup_create, | |
9459 | .destroy = cpu_cgroup_destroy, | |
9460 | .can_attach = cpu_cgroup_can_attach, | |
9461 | .attach = cpu_cgroup_attach, | |
9462 | .populate = cpu_cgroup_populate, | |
9463 | .subsys_id = cpu_cgroup_subsys_id, | |
68318b8e SV |
9464 | .early_init = 1, |
9465 | }; | |
9466 | ||
052f1dc7 | 9467 | #endif /* CONFIG_CGROUP_SCHED */ |
d842de87 SV |
9468 | |
9469 | #ifdef CONFIG_CGROUP_CPUACCT | |
9470 | ||
9471 | /* | |
9472 | * CPU accounting code for task groups. | |
9473 | * | |
9474 | * Based on the work by Paul Menage (menage@google.com) and Balbir Singh | |
9475 | * (balbir@in.ibm.com). | |
9476 | */ | |
9477 | ||
934352f2 | 9478 | /* track cpu usage of a group of tasks and its child groups */ |
d842de87 SV |
9479 | struct cpuacct { |
9480 | struct cgroup_subsys_state css; | |
9481 | /* cpuusage holds pointer to a u64-type object on every cpu */ | |
9482 | u64 *cpuusage; | |
934352f2 | 9483 | struct cpuacct *parent; |
d842de87 SV |
9484 | }; |
9485 | ||
9486 | struct cgroup_subsys cpuacct_subsys; | |
9487 | ||
9488 | /* return cpu accounting group corresponding to this container */ | |
32cd756a | 9489 | static inline struct cpuacct *cgroup_ca(struct cgroup *cgrp) |
d842de87 | 9490 | { |
32cd756a | 9491 | return container_of(cgroup_subsys_state(cgrp, cpuacct_subsys_id), |
d842de87 SV |
9492 | struct cpuacct, css); |
9493 | } | |
9494 | ||
9495 | /* return cpu accounting group to which this task belongs */ | |
9496 | static inline struct cpuacct *task_ca(struct task_struct *tsk) | |
9497 | { | |
9498 | return container_of(task_subsys_state(tsk, cpuacct_subsys_id), | |
9499 | struct cpuacct, css); | |
9500 | } | |
9501 | ||
9502 | /* create a new cpu accounting group */ | |
9503 | static struct cgroup_subsys_state *cpuacct_create( | |
32cd756a | 9504 | struct cgroup_subsys *ss, struct cgroup *cgrp) |
d842de87 SV |
9505 | { |
9506 | struct cpuacct *ca = kzalloc(sizeof(*ca), GFP_KERNEL); | |
9507 | ||
9508 | if (!ca) | |
9509 | return ERR_PTR(-ENOMEM); | |
9510 | ||
9511 | ca->cpuusage = alloc_percpu(u64); | |
9512 | if (!ca->cpuusage) { | |
9513 | kfree(ca); | |
9514 | return ERR_PTR(-ENOMEM); | |
9515 | } | |
9516 | ||
934352f2 BR |
9517 | if (cgrp->parent) |
9518 | ca->parent = cgroup_ca(cgrp->parent); | |
9519 | ||
d842de87 SV |
9520 | return &ca->css; |
9521 | } | |
9522 | ||
9523 | /* destroy an existing cpu accounting group */ | |
41a2d6cf | 9524 | static void |
32cd756a | 9525 | cpuacct_destroy(struct cgroup_subsys *ss, struct cgroup *cgrp) |
d842de87 | 9526 | { |
32cd756a | 9527 | struct cpuacct *ca = cgroup_ca(cgrp); |
d842de87 SV |
9528 | |
9529 | free_percpu(ca->cpuusage); | |
9530 | kfree(ca); | |
9531 | } | |
9532 | ||
720f5498 KC |
9533 | static u64 cpuacct_cpuusage_read(struct cpuacct *ca, int cpu) |
9534 | { | |
9535 | u64 *cpuusage = percpu_ptr(ca->cpuusage, cpu); | |
9536 | u64 data; | |
9537 | ||
9538 | #ifndef CONFIG_64BIT | |
9539 | /* | |
9540 | * Take rq->lock to make 64-bit read safe on 32-bit platforms. | |
9541 | */ | |
9542 | spin_lock_irq(&cpu_rq(cpu)->lock); | |
9543 | data = *cpuusage; | |
9544 | spin_unlock_irq(&cpu_rq(cpu)->lock); | |
9545 | #else | |
9546 | data = *cpuusage; | |
9547 | #endif | |
9548 | ||
9549 | return data; | |
9550 | } | |
9551 | ||
9552 | static void cpuacct_cpuusage_write(struct cpuacct *ca, int cpu, u64 val) | |
9553 | { | |
9554 | u64 *cpuusage = percpu_ptr(ca->cpuusage, cpu); | |
9555 | ||
9556 | #ifndef CONFIG_64BIT | |
9557 | /* | |
9558 | * Take rq->lock to make 64-bit write safe on 32-bit platforms. | |
9559 | */ | |
9560 | spin_lock_irq(&cpu_rq(cpu)->lock); | |
9561 | *cpuusage = val; | |
9562 | spin_unlock_irq(&cpu_rq(cpu)->lock); | |
9563 | #else | |
9564 | *cpuusage = val; | |
9565 | #endif | |
9566 | } | |
9567 | ||
d842de87 | 9568 | /* return total cpu usage (in nanoseconds) of a group */ |
32cd756a | 9569 | static u64 cpuusage_read(struct cgroup *cgrp, struct cftype *cft) |
d842de87 | 9570 | { |
32cd756a | 9571 | struct cpuacct *ca = cgroup_ca(cgrp); |
d842de87 SV |
9572 | u64 totalcpuusage = 0; |
9573 | int i; | |
9574 | ||
720f5498 KC |
9575 | for_each_present_cpu(i) |
9576 | totalcpuusage += cpuacct_cpuusage_read(ca, i); | |
d842de87 SV |
9577 | |
9578 | return totalcpuusage; | |
9579 | } | |
9580 | ||
0297b803 DG |
9581 | static int cpuusage_write(struct cgroup *cgrp, struct cftype *cftype, |
9582 | u64 reset) | |
9583 | { | |
9584 | struct cpuacct *ca = cgroup_ca(cgrp); | |
9585 | int err = 0; | |
9586 | int i; | |
9587 | ||
9588 | if (reset) { | |
9589 | err = -EINVAL; | |
9590 | goto out; | |
9591 | } | |
9592 | ||
720f5498 KC |
9593 | for_each_present_cpu(i) |
9594 | cpuacct_cpuusage_write(ca, i, 0); | |
0297b803 | 9595 | |
0297b803 DG |
9596 | out: |
9597 | return err; | |
9598 | } | |
9599 | ||
e9515c3c KC |
9600 | static int cpuacct_percpu_seq_read(struct cgroup *cgroup, struct cftype *cft, |
9601 | struct seq_file *m) | |
9602 | { | |
9603 | struct cpuacct *ca = cgroup_ca(cgroup); | |
9604 | u64 percpu; | |
9605 | int i; | |
9606 | ||
9607 | for_each_present_cpu(i) { | |
9608 | percpu = cpuacct_cpuusage_read(ca, i); | |
9609 | seq_printf(m, "%llu ", (unsigned long long) percpu); | |
9610 | } | |
9611 | seq_printf(m, "\n"); | |
9612 | return 0; | |
9613 | } | |
9614 | ||
d842de87 SV |
9615 | static struct cftype files[] = { |
9616 | { | |
9617 | .name = "usage", | |
f4c753b7 PM |
9618 | .read_u64 = cpuusage_read, |
9619 | .write_u64 = cpuusage_write, | |
d842de87 | 9620 | }, |
e9515c3c KC |
9621 | { |
9622 | .name = "usage_percpu", | |
9623 | .read_seq_string = cpuacct_percpu_seq_read, | |
9624 | }, | |
9625 | ||
d842de87 SV |
9626 | }; |
9627 | ||
32cd756a | 9628 | static int cpuacct_populate(struct cgroup_subsys *ss, struct cgroup *cgrp) |
d842de87 | 9629 | { |
32cd756a | 9630 | return cgroup_add_files(cgrp, ss, files, ARRAY_SIZE(files)); |
d842de87 SV |
9631 | } |
9632 | ||
9633 | /* | |
9634 | * charge this task's execution time to its accounting group. | |
9635 | * | |
9636 | * called with rq->lock held. | |
9637 | */ | |
9638 | static void cpuacct_charge(struct task_struct *tsk, u64 cputime) | |
9639 | { | |
9640 | struct cpuacct *ca; | |
934352f2 | 9641 | int cpu; |
d842de87 SV |
9642 | |
9643 | if (!cpuacct_subsys.active) | |
9644 | return; | |
9645 | ||
934352f2 | 9646 | cpu = task_cpu(tsk); |
d842de87 | 9647 | ca = task_ca(tsk); |
d842de87 | 9648 | |
934352f2 BR |
9649 | for (; ca; ca = ca->parent) { |
9650 | u64 *cpuusage = percpu_ptr(ca->cpuusage, cpu); | |
d842de87 SV |
9651 | *cpuusage += cputime; |
9652 | } | |
9653 | } | |
9654 | ||
9655 | struct cgroup_subsys cpuacct_subsys = { | |
9656 | .name = "cpuacct", | |
9657 | .create = cpuacct_create, | |
9658 | .destroy = cpuacct_destroy, | |
9659 | .populate = cpuacct_populate, | |
9660 | .subsys_id = cpuacct_subsys_id, | |
9661 | }; | |
9662 | #endif /* CONFIG_CGROUP_CPUACCT */ |