Commit | Line | Data |
---|---|---|
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 ED |
127 | #ifdef CONFIG_SMP |
128 | /* | |
129 | * Divide a load by a sched group cpu_power : (load / sg->__cpu_power) | |
130 | * Since cpu_power is a 'constant', we can use a reciprocal divide. | |
131 | */ | |
132 | static inline u32 sg_div_cpu_power(const struct sched_group *sg, u32 load) | |
133 | { | |
134 | return reciprocal_divide(load, sg->reciprocal_cpu_power); | |
135 | } | |
136 | ||
137 | /* | |
138 | * Each time a sched group cpu_power is changed, | |
139 | * we must compute its reciprocal value | |
140 | */ | |
141 | static inline void sg_inc_cpu_power(struct sched_group *sg, u32 val) | |
142 | { | |
143 | sg->__cpu_power += val; | |
144 | sg->reciprocal_cpu_power = reciprocal_value(sg->__cpu_power); | |
145 | } | |
146 | #endif | |
147 | ||
e05606d3 IM |
148 | static inline int rt_policy(int policy) |
149 | { | |
3f33a7ce | 150 | if (unlikely(policy == SCHED_FIFO || policy == SCHED_RR)) |
e05606d3 IM |
151 | return 1; |
152 | return 0; | |
153 | } | |
154 | ||
155 | static inline int task_has_rt_policy(struct task_struct *p) | |
156 | { | |
157 | return rt_policy(p->policy); | |
158 | } | |
159 | ||
1da177e4 | 160 | /* |
6aa645ea | 161 | * This is the priority-queue data structure of the RT scheduling class: |
1da177e4 | 162 | */ |
6aa645ea IM |
163 | struct rt_prio_array { |
164 | DECLARE_BITMAP(bitmap, MAX_RT_PRIO+1); /* include 1 bit for delimiter */ | |
165 | struct list_head queue[MAX_RT_PRIO]; | |
166 | }; | |
167 | ||
d0b27fa7 | 168 | struct rt_bandwidth { |
ea736ed5 IM |
169 | /* nests inside the rq lock: */ |
170 | spinlock_t rt_runtime_lock; | |
171 | ktime_t rt_period; | |
172 | u64 rt_runtime; | |
173 | struct hrtimer rt_period_timer; | |
d0b27fa7 PZ |
174 | }; |
175 | ||
176 | static struct rt_bandwidth def_rt_bandwidth; | |
177 | ||
178 | static int do_sched_rt_period_timer(struct rt_bandwidth *rt_b, int overrun); | |
179 | ||
180 | static enum hrtimer_restart sched_rt_period_timer(struct hrtimer *timer) | |
181 | { | |
182 | struct rt_bandwidth *rt_b = | |
183 | container_of(timer, struct rt_bandwidth, rt_period_timer); | |
184 | ktime_t now; | |
185 | int overrun; | |
186 | int idle = 0; | |
187 | ||
188 | for (;;) { | |
189 | now = hrtimer_cb_get_time(timer); | |
190 | overrun = hrtimer_forward(timer, now, rt_b->rt_period); | |
191 | ||
192 | if (!overrun) | |
193 | break; | |
194 | ||
195 | idle = do_sched_rt_period_timer(rt_b, overrun); | |
196 | } | |
197 | ||
198 | return idle ? HRTIMER_NORESTART : HRTIMER_RESTART; | |
199 | } | |
200 | ||
201 | static | |
202 | void init_rt_bandwidth(struct rt_bandwidth *rt_b, u64 period, u64 runtime) | |
203 | { | |
204 | rt_b->rt_period = ns_to_ktime(period); | |
205 | rt_b->rt_runtime = runtime; | |
206 | ||
ac086bc2 PZ |
207 | spin_lock_init(&rt_b->rt_runtime_lock); |
208 | ||
d0b27fa7 PZ |
209 | hrtimer_init(&rt_b->rt_period_timer, |
210 | CLOCK_MONOTONIC, HRTIMER_MODE_REL); | |
211 | rt_b->rt_period_timer.function = sched_rt_period_timer; | |
ccc7dadf | 212 | rt_b->rt_period_timer.cb_mode = HRTIMER_CB_IRQSAFE_UNLOCKED; |
d0b27fa7 PZ |
213 | } |
214 | ||
c8bfff6d KH |
215 | static inline int rt_bandwidth_enabled(void) |
216 | { | |
217 | return sysctl_sched_rt_runtime >= 0; | |
d0b27fa7 PZ |
218 | } |
219 | ||
220 | static void start_rt_bandwidth(struct rt_bandwidth *rt_b) | |
221 | { | |
222 | ktime_t now; | |
223 | ||
0b148fa0 | 224 | if (rt_bandwidth_enabled() && rt_b->rt_runtime == RUNTIME_INF) |
d0b27fa7 PZ |
225 | return; |
226 | ||
227 | if (hrtimer_active(&rt_b->rt_period_timer)) | |
228 | return; | |
229 | ||
230 | spin_lock(&rt_b->rt_runtime_lock); | |
231 | for (;;) { | |
232 | if (hrtimer_active(&rt_b->rt_period_timer)) | |
233 | break; | |
234 | ||
235 | now = hrtimer_cb_get_time(&rt_b->rt_period_timer); | |
236 | hrtimer_forward(&rt_b->rt_period_timer, now, rt_b->rt_period); | |
cc584b21 AV |
237 | hrtimer_start_expires(&rt_b->rt_period_timer, |
238 | HRTIMER_MODE_ABS); | |
d0b27fa7 PZ |
239 | } |
240 | spin_unlock(&rt_b->rt_runtime_lock); | |
241 | } | |
242 | ||
243 | #ifdef CONFIG_RT_GROUP_SCHED | |
244 | static void destroy_rt_bandwidth(struct rt_bandwidth *rt_b) | |
245 | { | |
246 | hrtimer_cancel(&rt_b->rt_period_timer); | |
247 | } | |
248 | #endif | |
249 | ||
712555ee HC |
250 | /* |
251 | * sched_domains_mutex serializes calls to arch_init_sched_domains, | |
252 | * detach_destroy_domains and partition_sched_domains. | |
253 | */ | |
254 | static DEFINE_MUTEX(sched_domains_mutex); | |
255 | ||
052f1dc7 | 256 | #ifdef CONFIG_GROUP_SCHED |
29f59db3 | 257 | |
68318b8e SV |
258 | #include <linux/cgroup.h> |
259 | ||
29f59db3 SV |
260 | struct cfs_rq; |
261 | ||
6f505b16 PZ |
262 | static LIST_HEAD(task_groups); |
263 | ||
29f59db3 | 264 | /* task group related information */ |
4cf86d77 | 265 | struct task_group { |
052f1dc7 | 266 | #ifdef CONFIG_CGROUP_SCHED |
68318b8e SV |
267 | struct cgroup_subsys_state css; |
268 | #endif | |
052f1dc7 PZ |
269 | |
270 | #ifdef CONFIG_FAIR_GROUP_SCHED | |
29f59db3 SV |
271 | /* schedulable entities of this group on each cpu */ |
272 | struct sched_entity **se; | |
273 | /* runqueue "owned" by this group on each cpu */ | |
274 | struct cfs_rq **cfs_rq; | |
275 | unsigned long shares; | |
052f1dc7 PZ |
276 | #endif |
277 | ||
278 | #ifdef CONFIG_RT_GROUP_SCHED | |
279 | struct sched_rt_entity **rt_se; | |
280 | struct rt_rq **rt_rq; | |
281 | ||
d0b27fa7 | 282 | struct rt_bandwidth rt_bandwidth; |
052f1dc7 | 283 | #endif |
6b2d7700 | 284 | |
ae8393e5 | 285 | struct rcu_head rcu; |
6f505b16 | 286 | struct list_head list; |
f473aa5e PZ |
287 | |
288 | struct task_group *parent; | |
289 | struct list_head siblings; | |
290 | struct list_head children; | |
29f59db3 SV |
291 | }; |
292 | ||
354d60c2 | 293 | #ifdef CONFIG_USER_SCHED |
eff766a6 PZ |
294 | |
295 | /* | |
296 | * Root task group. | |
297 | * Every UID task group (including init_task_group aka UID-0) will | |
298 | * be a child to this group. | |
299 | */ | |
300 | struct task_group root_task_group; | |
301 | ||
052f1dc7 | 302 | #ifdef CONFIG_FAIR_GROUP_SCHED |
29f59db3 SV |
303 | /* Default task group's sched entity on each cpu */ |
304 | static DEFINE_PER_CPU(struct sched_entity, init_sched_entity); | |
305 | /* Default task group's cfs_rq on each cpu */ | |
306 | static DEFINE_PER_CPU(struct cfs_rq, init_cfs_rq) ____cacheline_aligned_in_smp; | |
6d6bc0ad | 307 | #endif /* CONFIG_FAIR_GROUP_SCHED */ |
052f1dc7 PZ |
308 | |
309 | #ifdef CONFIG_RT_GROUP_SCHED | |
310 | static DEFINE_PER_CPU(struct sched_rt_entity, init_sched_rt_entity); | |
311 | static DEFINE_PER_CPU(struct rt_rq, init_rt_rq) ____cacheline_aligned_in_smp; | |
6d6bc0ad | 312 | #endif /* CONFIG_RT_GROUP_SCHED */ |
9a7e0b18 | 313 | #else /* !CONFIG_USER_SCHED */ |
eff766a6 | 314 | #define root_task_group init_task_group |
9a7e0b18 | 315 | #endif /* CONFIG_USER_SCHED */ |
6f505b16 | 316 | |
8ed36996 | 317 | /* task_group_lock serializes add/remove of task groups and also changes to |
ec2c507f SV |
318 | * a task group's cpu shares. |
319 | */ | |
8ed36996 | 320 | static DEFINE_SPINLOCK(task_group_lock); |
ec2c507f | 321 | |
052f1dc7 | 322 | #ifdef CONFIG_FAIR_GROUP_SCHED |
052f1dc7 PZ |
323 | #ifdef CONFIG_USER_SCHED |
324 | # define INIT_TASK_GROUP_LOAD (2*NICE_0_LOAD) | |
6d6bc0ad | 325 | #else /* !CONFIG_USER_SCHED */ |
052f1dc7 | 326 | # define INIT_TASK_GROUP_LOAD NICE_0_LOAD |
6d6bc0ad | 327 | #endif /* CONFIG_USER_SCHED */ |
052f1dc7 | 328 | |
cb4ad1ff | 329 | /* |
2e084786 LJ |
330 | * A weight of 0 or 1 can cause arithmetics problems. |
331 | * A weight of a cfs_rq is the sum of weights of which entities | |
332 | * are queued on this cfs_rq, so a weight of a entity should not be | |
333 | * too large, so as the shares value of a task group. | |
cb4ad1ff MX |
334 | * (The default weight is 1024 - so there's no practical |
335 | * limitation from this.) | |
336 | */ | |
18d95a28 | 337 | #define MIN_SHARES 2 |
2e084786 | 338 | #define MAX_SHARES (1UL << 18) |
18d95a28 | 339 | |
052f1dc7 PZ |
340 | static int init_task_group_load = INIT_TASK_GROUP_LOAD; |
341 | #endif | |
342 | ||
29f59db3 | 343 | /* Default task group. |
3a252015 | 344 | * Every task in system belong to this group at bootup. |
29f59db3 | 345 | */ |
434d53b0 | 346 | struct task_group init_task_group; |
29f59db3 SV |
347 | |
348 | /* return group to which a task belongs */ | |
4cf86d77 | 349 | static inline struct task_group *task_group(struct task_struct *p) |
29f59db3 | 350 | { |
4cf86d77 | 351 | struct task_group *tg; |
9b5b7751 | 352 | |
052f1dc7 | 353 | #ifdef CONFIG_USER_SCHED |
24e377a8 | 354 | tg = p->user->tg; |
052f1dc7 | 355 | #elif defined(CONFIG_CGROUP_SCHED) |
68318b8e SV |
356 | tg = container_of(task_subsys_state(p, cpu_cgroup_subsys_id), |
357 | struct task_group, css); | |
24e377a8 | 358 | #else |
41a2d6cf | 359 | tg = &init_task_group; |
24e377a8 | 360 | #endif |
9b5b7751 | 361 | return tg; |
29f59db3 SV |
362 | } |
363 | ||
364 | /* Change a task's cfs_rq and parent entity if it moves across CPUs/groups */ | |
6f505b16 | 365 | static inline void set_task_rq(struct task_struct *p, unsigned int cpu) |
29f59db3 | 366 | { |
052f1dc7 | 367 | #ifdef CONFIG_FAIR_GROUP_SCHED |
ce96b5ac DA |
368 | p->se.cfs_rq = task_group(p)->cfs_rq[cpu]; |
369 | p->se.parent = task_group(p)->se[cpu]; | |
052f1dc7 | 370 | #endif |
6f505b16 | 371 | |
052f1dc7 | 372 | #ifdef CONFIG_RT_GROUP_SCHED |
6f505b16 PZ |
373 | p->rt.rt_rq = task_group(p)->rt_rq[cpu]; |
374 | p->rt.parent = task_group(p)->rt_se[cpu]; | |
052f1dc7 | 375 | #endif |
29f59db3 SV |
376 | } |
377 | ||
378 | #else | |
379 | ||
6f505b16 | 380 | static inline void set_task_rq(struct task_struct *p, unsigned int cpu) { } |
83378269 PZ |
381 | static inline struct task_group *task_group(struct task_struct *p) |
382 | { | |
383 | return NULL; | |
384 | } | |
29f59db3 | 385 | |
052f1dc7 | 386 | #endif /* CONFIG_GROUP_SCHED */ |
29f59db3 | 387 | |
6aa645ea IM |
388 | /* CFS-related fields in a runqueue */ |
389 | struct cfs_rq { | |
390 | struct load_weight load; | |
391 | unsigned long nr_running; | |
392 | ||
6aa645ea | 393 | u64 exec_clock; |
e9acbff6 | 394 | u64 min_vruntime; |
6aa645ea IM |
395 | |
396 | struct rb_root tasks_timeline; | |
397 | struct rb_node *rb_leftmost; | |
4a55bd5e PZ |
398 | |
399 | struct list_head tasks; | |
400 | struct list_head *balance_iterator; | |
401 | ||
402 | /* | |
403 | * 'curr' points to currently running entity on this cfs_rq. | |
6aa645ea IM |
404 | * It is set to NULL otherwise (i.e when none are currently running). |
405 | */ | |
4793241b | 406 | struct sched_entity *curr, *next, *last; |
ddc97297 | 407 | |
5ac5c4d6 | 408 | unsigned int nr_spread_over; |
ddc97297 | 409 | |
62160e3f | 410 | #ifdef CONFIG_FAIR_GROUP_SCHED |
6aa645ea IM |
411 | struct rq *rq; /* cpu runqueue to which this cfs_rq is attached */ |
412 | ||
41a2d6cf IM |
413 | /* |
414 | * leaf cfs_rqs are those that hold tasks (lowest schedulable entity in | |
6aa645ea IM |
415 | * a hierarchy). Non-leaf lrqs hold other higher schedulable entities |
416 | * (like users, containers etc.) | |
417 | * | |
418 | * leaf_cfs_rq_list ties together list of leaf cfs_rq's in a cpu. This | |
419 | * list is used during load balance. | |
420 | */ | |
41a2d6cf IM |
421 | struct list_head leaf_cfs_rq_list; |
422 | struct task_group *tg; /* group that "owns" this runqueue */ | |
c09595f6 PZ |
423 | |
424 | #ifdef CONFIG_SMP | |
c09595f6 | 425 | /* |
c8cba857 | 426 | * the part of load.weight contributed by tasks |
c09595f6 | 427 | */ |
c8cba857 | 428 | unsigned long task_weight; |
c09595f6 | 429 | |
c8cba857 PZ |
430 | /* |
431 | * h_load = weight * f(tg) | |
432 | * | |
433 | * Where f(tg) is the recursive weight fraction assigned to | |
434 | * this group. | |
435 | */ | |
436 | unsigned long h_load; | |
c09595f6 | 437 | |
c8cba857 PZ |
438 | /* |
439 | * this cpu's part of tg->shares | |
440 | */ | |
441 | unsigned long shares; | |
f1d239f7 PZ |
442 | |
443 | /* | |
444 | * load.weight at the time we set shares | |
445 | */ | |
446 | unsigned long rq_weight; | |
c09595f6 | 447 | #endif |
6aa645ea IM |
448 | #endif |
449 | }; | |
1da177e4 | 450 | |
6aa645ea IM |
451 | /* Real-Time classes' related field in a runqueue: */ |
452 | struct rt_rq { | |
453 | struct rt_prio_array active; | |
63489e45 | 454 | unsigned long rt_nr_running; |
052f1dc7 | 455 | #if defined CONFIG_SMP || defined CONFIG_RT_GROUP_SCHED |
6f505b16 PZ |
456 | int highest_prio; /* highest queued rt task prio */ |
457 | #endif | |
fa85ae24 | 458 | #ifdef CONFIG_SMP |
73fe6aae | 459 | unsigned long rt_nr_migratory; |
a22d7fc1 | 460 | int overloaded; |
fa85ae24 | 461 | #endif |
6f505b16 | 462 | int rt_throttled; |
fa85ae24 | 463 | u64 rt_time; |
ac086bc2 | 464 | u64 rt_runtime; |
ea736ed5 | 465 | /* Nests inside the rq lock: */ |
ac086bc2 | 466 | spinlock_t rt_runtime_lock; |
6f505b16 | 467 | |
052f1dc7 | 468 | #ifdef CONFIG_RT_GROUP_SCHED |
23b0fdfc PZ |
469 | unsigned long rt_nr_boosted; |
470 | ||
6f505b16 PZ |
471 | struct rq *rq; |
472 | struct list_head leaf_rt_rq_list; | |
473 | struct task_group *tg; | |
474 | struct sched_rt_entity *rt_se; | |
475 | #endif | |
6aa645ea IM |
476 | }; |
477 | ||
57d885fe GH |
478 | #ifdef CONFIG_SMP |
479 | ||
480 | /* | |
481 | * We add the notion of a root-domain which will be used to define per-domain | |
0eab9146 IM |
482 | * variables. Each exclusive cpuset essentially defines an island domain by |
483 | * fully partitioning the member cpus from any other cpuset. Whenever a new | |
57d885fe GH |
484 | * exclusive cpuset is created, we also create and attach a new root-domain |
485 | * object. | |
486 | * | |
57d885fe GH |
487 | */ |
488 | struct root_domain { | |
489 | atomic_t refcount; | |
490 | cpumask_t span; | |
491 | cpumask_t online; | |
637f5085 | 492 | |
0eab9146 | 493 | /* |
637f5085 GH |
494 | * The "RT overload" flag: it gets set if a CPU has more than |
495 | * one runnable RT task. | |
496 | */ | |
497 | cpumask_t rto_mask; | |
0eab9146 | 498 | atomic_t rto_count; |
6e0534f2 GH |
499 | #ifdef CONFIG_SMP |
500 | struct cpupri cpupri; | |
501 | #endif | |
57d885fe GH |
502 | }; |
503 | ||
dc938520 GH |
504 | /* |
505 | * By default the system creates a single root-domain with all cpus as | |
506 | * members (mimicking the global state we have today). | |
507 | */ | |
57d885fe GH |
508 | static struct root_domain def_root_domain; |
509 | ||
510 | #endif | |
511 | ||
1da177e4 LT |
512 | /* |
513 | * This is the main, per-CPU runqueue data structure. | |
514 | * | |
515 | * Locking rule: those places that want to lock multiple runqueues | |
516 | * (such as the load balancing or the thread migration code), lock | |
517 | * acquire operations must be ordered by ascending &runqueue. | |
518 | */ | |
70b97a7f | 519 | struct rq { |
d8016491 IM |
520 | /* runqueue lock: */ |
521 | spinlock_t lock; | |
1da177e4 LT |
522 | |
523 | /* | |
524 | * nr_running and cpu_load should be in the same cacheline because | |
525 | * remote CPUs use both these fields when doing load calculation. | |
526 | */ | |
527 | unsigned long nr_running; | |
6aa645ea IM |
528 | #define CPU_LOAD_IDX_MAX 5 |
529 | unsigned long cpu_load[CPU_LOAD_IDX_MAX]; | |
bdecea3a | 530 | unsigned char idle_at_tick; |
46cb4b7c | 531 | #ifdef CONFIG_NO_HZ |
15934a37 | 532 | unsigned long last_tick_seen; |
46cb4b7c SS |
533 | unsigned char in_nohz_recently; |
534 | #endif | |
d8016491 IM |
535 | /* capture load from *all* tasks on this cpu: */ |
536 | struct load_weight load; | |
6aa645ea IM |
537 | unsigned long nr_load_updates; |
538 | u64 nr_switches; | |
539 | ||
540 | struct cfs_rq cfs; | |
6f505b16 | 541 | struct rt_rq rt; |
6f505b16 | 542 | |
6aa645ea | 543 | #ifdef CONFIG_FAIR_GROUP_SCHED |
d8016491 IM |
544 | /* list of leaf cfs_rq on this cpu: */ |
545 | struct list_head leaf_cfs_rq_list; | |
052f1dc7 PZ |
546 | #endif |
547 | #ifdef CONFIG_RT_GROUP_SCHED | |
6f505b16 | 548 | struct list_head leaf_rt_rq_list; |
1da177e4 | 549 | #endif |
1da177e4 LT |
550 | |
551 | /* | |
552 | * This is part of a global counter where only the total sum | |
553 | * over all CPUs matters. A task can increase this counter on | |
554 | * one CPU and if it got migrated afterwards it may decrease | |
555 | * it on another CPU. Always updated under the runqueue lock: | |
556 | */ | |
557 | unsigned long nr_uninterruptible; | |
558 | ||
36c8b586 | 559 | struct task_struct *curr, *idle; |
c9819f45 | 560 | unsigned long next_balance; |
1da177e4 | 561 | struct mm_struct *prev_mm; |
6aa645ea | 562 | |
3e51f33f | 563 | u64 clock; |
6aa645ea | 564 | |
1da177e4 LT |
565 | atomic_t nr_iowait; |
566 | ||
567 | #ifdef CONFIG_SMP | |
0eab9146 | 568 | struct root_domain *rd; |
1da177e4 LT |
569 | struct sched_domain *sd; |
570 | ||
571 | /* For active balancing */ | |
572 | int active_balance; | |
573 | int push_cpu; | |
d8016491 IM |
574 | /* cpu of this runqueue: */ |
575 | int cpu; | |
1f11eb6a | 576 | int online; |
1da177e4 | 577 | |
a8a51d5e | 578 | unsigned long avg_load_per_task; |
1da177e4 | 579 | |
36c8b586 | 580 | struct task_struct *migration_thread; |
1da177e4 LT |
581 | struct list_head migration_queue; |
582 | #endif | |
583 | ||
8f4d37ec | 584 | #ifdef CONFIG_SCHED_HRTICK |
31656519 PZ |
585 | #ifdef CONFIG_SMP |
586 | int hrtick_csd_pending; | |
587 | struct call_single_data hrtick_csd; | |
588 | #endif | |
8f4d37ec PZ |
589 | struct hrtimer hrtick_timer; |
590 | #endif | |
591 | ||
1da177e4 LT |
592 | #ifdef CONFIG_SCHEDSTATS |
593 | /* latency stats */ | |
594 | struct sched_info rq_sched_info; | |
595 | ||
596 | /* sys_sched_yield() stats */ | |
480b9434 KC |
597 | unsigned int yld_exp_empty; |
598 | unsigned int yld_act_empty; | |
599 | unsigned int yld_both_empty; | |
600 | unsigned int yld_count; | |
1da177e4 LT |
601 | |
602 | /* schedule() stats */ | |
480b9434 KC |
603 | unsigned int sched_switch; |
604 | unsigned int sched_count; | |
605 | unsigned int sched_goidle; | |
1da177e4 LT |
606 | |
607 | /* try_to_wake_up() stats */ | |
480b9434 KC |
608 | unsigned int ttwu_count; |
609 | unsigned int ttwu_local; | |
b8efb561 IM |
610 | |
611 | /* BKL stats */ | |
480b9434 | 612 | unsigned int bkl_count; |
1da177e4 LT |
613 | #endif |
614 | }; | |
615 | ||
f34e3b61 | 616 | static DEFINE_PER_CPU_SHARED_ALIGNED(struct rq, runqueues); |
1da177e4 | 617 | |
15afe09b | 618 | static inline void check_preempt_curr(struct rq *rq, struct task_struct *p, int sync) |
dd41f596 | 619 | { |
15afe09b | 620 | rq->curr->sched_class->check_preempt_curr(rq, p, sync); |
dd41f596 IM |
621 | } |
622 | ||
0a2966b4 CL |
623 | static inline int cpu_of(struct rq *rq) |
624 | { | |
625 | #ifdef CONFIG_SMP | |
626 | return rq->cpu; | |
627 | #else | |
628 | return 0; | |
629 | #endif | |
630 | } | |
631 | ||
674311d5 NP |
632 | /* |
633 | * The domain tree (rq->sd) is protected by RCU's quiescent state transition. | |
1a20ff27 | 634 | * See detach_destroy_domains: synchronize_sched for details. |
674311d5 NP |
635 | * |
636 | * The domain tree of any CPU may only be accessed from within | |
637 | * preempt-disabled sections. | |
638 | */ | |
48f24c4d IM |
639 | #define for_each_domain(cpu, __sd) \ |
640 | for (__sd = rcu_dereference(cpu_rq(cpu)->sd); __sd; __sd = __sd->parent) | |
1da177e4 LT |
641 | |
642 | #define cpu_rq(cpu) (&per_cpu(runqueues, (cpu))) | |
643 | #define this_rq() (&__get_cpu_var(runqueues)) | |
644 | #define task_rq(p) cpu_rq(task_cpu(p)) | |
645 | #define cpu_curr(cpu) (cpu_rq(cpu)->curr) | |
646 | ||
3e51f33f PZ |
647 | static inline void update_rq_clock(struct rq *rq) |
648 | { | |
649 | rq->clock = sched_clock_cpu(cpu_of(rq)); | |
650 | } | |
651 | ||
bf5c91ba IM |
652 | /* |
653 | * Tunables that become constants when CONFIG_SCHED_DEBUG is off: | |
654 | */ | |
655 | #ifdef CONFIG_SCHED_DEBUG | |
656 | # define const_debug __read_mostly | |
657 | #else | |
658 | # define const_debug static const | |
659 | #endif | |
660 | ||
017730c1 IM |
661 | /** |
662 | * runqueue_is_locked | |
663 | * | |
664 | * Returns true if the current cpu runqueue is locked. | |
665 | * This interface allows printk to be called with the runqueue lock | |
666 | * held and know whether or not it is OK to wake up the klogd. | |
667 | */ | |
668 | int runqueue_is_locked(void) | |
669 | { | |
670 | int cpu = get_cpu(); | |
671 | struct rq *rq = cpu_rq(cpu); | |
672 | int ret; | |
673 | ||
674 | ret = spin_is_locked(&rq->lock); | |
675 | put_cpu(); | |
676 | return ret; | |
677 | } | |
678 | ||
bf5c91ba IM |
679 | /* |
680 | * Debugging: various feature bits | |
681 | */ | |
f00b45c1 PZ |
682 | |
683 | #define SCHED_FEAT(name, enabled) \ | |
684 | __SCHED_FEAT_##name , | |
685 | ||
bf5c91ba | 686 | enum { |
f00b45c1 | 687 | #include "sched_features.h" |
bf5c91ba IM |
688 | }; |
689 | ||
f00b45c1 PZ |
690 | #undef SCHED_FEAT |
691 | ||
692 | #define SCHED_FEAT(name, enabled) \ | |
693 | (1UL << __SCHED_FEAT_##name) * enabled | | |
694 | ||
bf5c91ba | 695 | const_debug unsigned int sysctl_sched_features = |
f00b45c1 PZ |
696 | #include "sched_features.h" |
697 | 0; | |
698 | ||
699 | #undef SCHED_FEAT | |
700 | ||
701 | #ifdef CONFIG_SCHED_DEBUG | |
702 | #define SCHED_FEAT(name, enabled) \ | |
703 | #name , | |
704 | ||
983ed7a6 | 705 | static __read_mostly char *sched_feat_names[] = { |
f00b45c1 PZ |
706 | #include "sched_features.h" |
707 | NULL | |
708 | }; | |
709 | ||
710 | #undef SCHED_FEAT | |
711 | ||
34f3a814 | 712 | static int sched_feat_show(struct seq_file *m, void *v) |
f00b45c1 | 713 | { |
f00b45c1 PZ |
714 | int i; |
715 | ||
716 | for (i = 0; sched_feat_names[i]; i++) { | |
34f3a814 LZ |
717 | if (!(sysctl_sched_features & (1UL << i))) |
718 | seq_puts(m, "NO_"); | |
719 | seq_printf(m, "%s ", sched_feat_names[i]); | |
f00b45c1 | 720 | } |
34f3a814 | 721 | seq_puts(m, "\n"); |
f00b45c1 | 722 | |
34f3a814 | 723 | return 0; |
f00b45c1 PZ |
724 | } |
725 | ||
726 | static ssize_t | |
727 | sched_feat_write(struct file *filp, const char __user *ubuf, | |
728 | size_t cnt, loff_t *ppos) | |
729 | { | |
730 | char buf[64]; | |
731 | char *cmp = buf; | |
732 | int neg = 0; | |
733 | int i; | |
734 | ||
735 | if (cnt > 63) | |
736 | cnt = 63; | |
737 | ||
738 | if (copy_from_user(&buf, ubuf, cnt)) | |
739 | return -EFAULT; | |
740 | ||
741 | buf[cnt] = 0; | |
742 | ||
c24b7c52 | 743 | if (strncmp(buf, "NO_", 3) == 0) { |
f00b45c1 PZ |
744 | neg = 1; |
745 | cmp += 3; | |
746 | } | |
747 | ||
748 | for (i = 0; sched_feat_names[i]; i++) { | |
749 | int len = strlen(sched_feat_names[i]); | |
750 | ||
751 | if (strncmp(cmp, sched_feat_names[i], len) == 0) { | |
752 | if (neg) | |
753 | sysctl_sched_features &= ~(1UL << i); | |
754 | else | |
755 | sysctl_sched_features |= (1UL << i); | |
756 | break; | |
757 | } | |
758 | } | |
759 | ||
760 | if (!sched_feat_names[i]) | |
761 | return -EINVAL; | |
762 | ||
763 | filp->f_pos += cnt; | |
764 | ||
765 | return cnt; | |
766 | } | |
767 | ||
34f3a814 LZ |
768 | static int sched_feat_open(struct inode *inode, struct file *filp) |
769 | { | |
770 | return single_open(filp, sched_feat_show, NULL); | |
771 | } | |
772 | ||
f00b45c1 | 773 | static struct file_operations sched_feat_fops = { |
34f3a814 LZ |
774 | .open = sched_feat_open, |
775 | .write = sched_feat_write, | |
776 | .read = seq_read, | |
777 | .llseek = seq_lseek, | |
778 | .release = single_release, | |
f00b45c1 PZ |
779 | }; |
780 | ||
781 | static __init int sched_init_debug(void) | |
782 | { | |
f00b45c1 PZ |
783 | debugfs_create_file("sched_features", 0644, NULL, NULL, |
784 | &sched_feat_fops); | |
785 | ||
786 | return 0; | |
787 | } | |
788 | late_initcall(sched_init_debug); | |
789 | ||
790 | #endif | |
791 | ||
792 | #define sched_feat(x) (sysctl_sched_features & (1UL << __SCHED_FEAT_##x)) | |
bf5c91ba | 793 | |
b82d9fdd PZ |
794 | /* |
795 | * Number of tasks to iterate in a single balance run. | |
796 | * Limited because this is done with IRQs disabled. | |
797 | */ | |
798 | const_debug unsigned int sysctl_sched_nr_migrate = 32; | |
799 | ||
2398f2c6 PZ |
800 | /* |
801 | * ratelimit for updating the group shares. | |
55cd5340 | 802 | * default: 0.25ms |
2398f2c6 | 803 | */ |
55cd5340 | 804 | unsigned int sysctl_sched_shares_ratelimit = 250000; |
2398f2c6 | 805 | |
ffda12a1 PZ |
806 | /* |
807 | * Inject some fuzzyness into changing the per-cpu group shares | |
808 | * this avoids remote rq-locks at the expense of fairness. | |
809 | * default: 4 | |
810 | */ | |
811 | unsigned int sysctl_sched_shares_thresh = 4; | |
812 | ||
fa85ae24 | 813 | /* |
9f0c1e56 | 814 | * period over which we measure -rt task cpu usage in us. |
fa85ae24 PZ |
815 | * default: 1s |
816 | */ | |
9f0c1e56 | 817 | unsigned int sysctl_sched_rt_period = 1000000; |
fa85ae24 | 818 | |
6892b75e IM |
819 | static __read_mostly int scheduler_running; |
820 | ||
9f0c1e56 PZ |
821 | /* |
822 | * part of the period that we allow rt tasks to run in us. | |
823 | * default: 0.95s | |
824 | */ | |
825 | int sysctl_sched_rt_runtime = 950000; | |
fa85ae24 | 826 | |
d0b27fa7 PZ |
827 | static inline u64 global_rt_period(void) |
828 | { | |
829 | return (u64)sysctl_sched_rt_period * NSEC_PER_USEC; | |
830 | } | |
831 | ||
832 | static inline u64 global_rt_runtime(void) | |
833 | { | |
e26873bb | 834 | if (sysctl_sched_rt_runtime < 0) |
d0b27fa7 PZ |
835 | return RUNTIME_INF; |
836 | ||
837 | return (u64)sysctl_sched_rt_runtime * NSEC_PER_USEC; | |
838 | } | |
fa85ae24 | 839 | |
1da177e4 | 840 | #ifndef prepare_arch_switch |
4866cde0 NP |
841 | # define prepare_arch_switch(next) do { } while (0) |
842 | #endif | |
843 | #ifndef finish_arch_switch | |
844 | # define finish_arch_switch(prev) do { } while (0) | |
845 | #endif | |
846 | ||
051a1d1a DA |
847 | static inline int task_current(struct rq *rq, struct task_struct *p) |
848 | { | |
849 | return rq->curr == p; | |
850 | } | |
851 | ||
4866cde0 | 852 | #ifndef __ARCH_WANT_UNLOCKED_CTXSW |
70b97a7f | 853 | static inline int task_running(struct rq *rq, struct task_struct *p) |
4866cde0 | 854 | { |
051a1d1a | 855 | return task_current(rq, p); |
4866cde0 NP |
856 | } |
857 | ||
70b97a7f | 858 | static inline void prepare_lock_switch(struct rq *rq, struct task_struct *next) |
4866cde0 NP |
859 | { |
860 | } | |
861 | ||
70b97a7f | 862 | static inline void finish_lock_switch(struct rq *rq, struct task_struct *prev) |
4866cde0 | 863 | { |
da04c035 IM |
864 | #ifdef CONFIG_DEBUG_SPINLOCK |
865 | /* this is a valid case when another task releases the spinlock */ | |
866 | rq->lock.owner = current; | |
867 | #endif | |
8a25d5de IM |
868 | /* |
869 | * If we are tracking spinlock dependencies then we have to | |
870 | * fix up the runqueue lock - which gets 'carried over' from | |
871 | * prev into current: | |
872 | */ | |
873 | spin_acquire(&rq->lock.dep_map, 0, 0, _THIS_IP_); | |
874 | ||
4866cde0 NP |
875 | spin_unlock_irq(&rq->lock); |
876 | } | |
877 | ||
878 | #else /* __ARCH_WANT_UNLOCKED_CTXSW */ | |
70b97a7f | 879 | static inline int task_running(struct rq *rq, struct task_struct *p) |
4866cde0 NP |
880 | { |
881 | #ifdef CONFIG_SMP | |
882 | return p->oncpu; | |
883 | #else | |
051a1d1a | 884 | return task_current(rq, p); |
4866cde0 NP |
885 | #endif |
886 | } | |
887 | ||
70b97a7f | 888 | static inline void prepare_lock_switch(struct rq *rq, struct task_struct *next) |
4866cde0 NP |
889 | { |
890 | #ifdef CONFIG_SMP | |
891 | /* | |
892 | * We can optimise this out completely for !SMP, because the | |
893 | * SMP rebalancing from interrupt is the only thing that cares | |
894 | * here. | |
895 | */ | |
896 | next->oncpu = 1; | |
897 | #endif | |
898 | #ifdef __ARCH_WANT_INTERRUPTS_ON_CTXSW | |
899 | spin_unlock_irq(&rq->lock); | |
900 | #else | |
901 | spin_unlock(&rq->lock); | |
902 | #endif | |
903 | } | |
904 | ||
70b97a7f | 905 | static inline void finish_lock_switch(struct rq *rq, struct task_struct *prev) |
4866cde0 NP |
906 | { |
907 | #ifdef CONFIG_SMP | |
908 | /* | |
909 | * After ->oncpu is cleared, the task can be moved to a different CPU. | |
910 | * We must ensure this doesn't happen until the switch is completely | |
911 | * finished. | |
912 | */ | |
913 | smp_wmb(); | |
914 | prev->oncpu = 0; | |
915 | #endif | |
916 | #ifndef __ARCH_WANT_INTERRUPTS_ON_CTXSW | |
917 | local_irq_enable(); | |
1da177e4 | 918 | #endif |
4866cde0 NP |
919 | } |
920 | #endif /* __ARCH_WANT_UNLOCKED_CTXSW */ | |
1da177e4 | 921 | |
b29739f9 IM |
922 | /* |
923 | * __task_rq_lock - lock the runqueue a given task resides on. | |
924 | * Must be called interrupts disabled. | |
925 | */ | |
70b97a7f | 926 | static inline struct rq *__task_rq_lock(struct task_struct *p) |
b29739f9 IM |
927 | __acquires(rq->lock) |
928 | { | |
3a5c359a AK |
929 | for (;;) { |
930 | struct rq *rq = task_rq(p); | |
931 | spin_lock(&rq->lock); | |
932 | if (likely(rq == task_rq(p))) | |
933 | return rq; | |
b29739f9 | 934 | spin_unlock(&rq->lock); |
b29739f9 | 935 | } |
b29739f9 IM |
936 | } |
937 | ||
1da177e4 LT |
938 | /* |
939 | * task_rq_lock - lock the runqueue a given task resides on and disable | |
41a2d6cf | 940 | * interrupts. Note the ordering: we can safely lookup the task_rq without |
1da177e4 LT |
941 | * explicitly disabling preemption. |
942 | */ | |
70b97a7f | 943 | static struct rq *task_rq_lock(struct task_struct *p, unsigned long *flags) |
1da177e4 LT |
944 | __acquires(rq->lock) |
945 | { | |
70b97a7f | 946 | struct rq *rq; |
1da177e4 | 947 | |
3a5c359a AK |
948 | for (;;) { |
949 | local_irq_save(*flags); | |
950 | rq = task_rq(p); | |
951 | spin_lock(&rq->lock); | |
952 | if (likely(rq == task_rq(p))) | |
953 | return rq; | |
1da177e4 | 954 | spin_unlock_irqrestore(&rq->lock, *flags); |
1da177e4 | 955 | } |
1da177e4 LT |
956 | } |
957 | ||
ad474cac ON |
958 | void task_rq_unlock_wait(struct task_struct *p) |
959 | { | |
960 | struct rq *rq = task_rq(p); | |
961 | ||
962 | smp_mb(); /* spin-unlock-wait is not a full memory barrier */ | |
963 | spin_unlock_wait(&rq->lock); | |
964 | } | |
965 | ||
a9957449 | 966 | static void __task_rq_unlock(struct rq *rq) |
b29739f9 IM |
967 | __releases(rq->lock) |
968 | { | |
969 | spin_unlock(&rq->lock); | |
970 | } | |
971 | ||
70b97a7f | 972 | static inline void task_rq_unlock(struct rq *rq, unsigned long *flags) |
1da177e4 LT |
973 | __releases(rq->lock) |
974 | { | |
975 | spin_unlock_irqrestore(&rq->lock, *flags); | |
976 | } | |
977 | ||
1da177e4 | 978 | /* |
cc2a73b5 | 979 | * this_rq_lock - lock this runqueue and disable interrupts. |
1da177e4 | 980 | */ |
a9957449 | 981 | static struct rq *this_rq_lock(void) |
1da177e4 LT |
982 | __acquires(rq->lock) |
983 | { | |
70b97a7f | 984 | struct rq *rq; |
1da177e4 LT |
985 | |
986 | local_irq_disable(); | |
987 | rq = this_rq(); | |
988 | spin_lock(&rq->lock); | |
989 | ||
990 | return rq; | |
991 | } | |
992 | ||
8f4d37ec PZ |
993 | #ifdef CONFIG_SCHED_HRTICK |
994 | /* | |
995 | * Use HR-timers to deliver accurate preemption points. | |
996 | * | |
997 | * Its all a bit involved since we cannot program an hrt while holding the | |
998 | * rq->lock. So what we do is store a state in in rq->hrtick_* and ask for a | |
999 | * reschedule event. | |
1000 | * | |
1001 | * When we get rescheduled we reprogram the hrtick_timer outside of the | |
1002 | * rq->lock. | |
1003 | */ | |
8f4d37ec PZ |
1004 | |
1005 | /* | |
1006 | * Use hrtick when: | |
1007 | * - enabled by features | |
1008 | * - hrtimer is actually high res | |
1009 | */ | |
1010 | static inline int hrtick_enabled(struct rq *rq) | |
1011 | { | |
1012 | if (!sched_feat(HRTICK)) | |
1013 | return 0; | |
ba42059f | 1014 | if (!cpu_active(cpu_of(rq))) |
b328ca18 | 1015 | return 0; |
8f4d37ec PZ |
1016 | return hrtimer_is_hres_active(&rq->hrtick_timer); |
1017 | } | |
1018 | ||
8f4d37ec PZ |
1019 | static void hrtick_clear(struct rq *rq) |
1020 | { | |
1021 | if (hrtimer_active(&rq->hrtick_timer)) | |
1022 | hrtimer_cancel(&rq->hrtick_timer); | |
1023 | } | |
1024 | ||
8f4d37ec PZ |
1025 | /* |
1026 | * High-resolution timer tick. | |
1027 | * Runs from hardirq context with interrupts disabled. | |
1028 | */ | |
1029 | static enum hrtimer_restart hrtick(struct hrtimer *timer) | |
1030 | { | |
1031 | struct rq *rq = container_of(timer, struct rq, hrtick_timer); | |
1032 | ||
1033 | WARN_ON_ONCE(cpu_of(rq) != smp_processor_id()); | |
1034 | ||
1035 | spin_lock(&rq->lock); | |
3e51f33f | 1036 | update_rq_clock(rq); |
8f4d37ec PZ |
1037 | rq->curr->sched_class->task_tick(rq, rq->curr, 1); |
1038 | spin_unlock(&rq->lock); | |
1039 | ||
1040 | return HRTIMER_NORESTART; | |
1041 | } | |
1042 | ||
95e904c7 | 1043 | #ifdef CONFIG_SMP |
31656519 PZ |
1044 | /* |
1045 | * called from hardirq (IPI) context | |
1046 | */ | |
1047 | static void __hrtick_start(void *arg) | |
b328ca18 | 1048 | { |
31656519 | 1049 | struct rq *rq = arg; |
b328ca18 | 1050 | |
31656519 PZ |
1051 | spin_lock(&rq->lock); |
1052 | hrtimer_restart(&rq->hrtick_timer); | |
1053 | rq->hrtick_csd_pending = 0; | |
1054 | spin_unlock(&rq->lock); | |
b328ca18 PZ |
1055 | } |
1056 | ||
31656519 PZ |
1057 | /* |
1058 | * Called to set the hrtick timer state. | |
1059 | * | |
1060 | * called with rq->lock held and irqs disabled | |
1061 | */ | |
1062 | static void hrtick_start(struct rq *rq, u64 delay) | |
b328ca18 | 1063 | { |
31656519 PZ |
1064 | struct hrtimer *timer = &rq->hrtick_timer; |
1065 | ktime_t time = ktime_add_ns(timer->base->get_time(), delay); | |
b328ca18 | 1066 | |
cc584b21 | 1067 | hrtimer_set_expires(timer, time); |
31656519 PZ |
1068 | |
1069 | if (rq == this_rq()) { | |
1070 | hrtimer_restart(timer); | |
1071 | } else if (!rq->hrtick_csd_pending) { | |
1072 | __smp_call_function_single(cpu_of(rq), &rq->hrtick_csd); | |
1073 | rq->hrtick_csd_pending = 1; | |
1074 | } | |
b328ca18 PZ |
1075 | } |
1076 | ||
1077 | static int | |
1078 | hotplug_hrtick(struct notifier_block *nfb, unsigned long action, void *hcpu) | |
1079 | { | |
1080 | int cpu = (int)(long)hcpu; | |
1081 | ||
1082 | switch (action) { | |
1083 | case CPU_UP_CANCELED: | |
1084 | case CPU_UP_CANCELED_FROZEN: | |
1085 | case CPU_DOWN_PREPARE: | |
1086 | case CPU_DOWN_PREPARE_FROZEN: | |
1087 | case CPU_DEAD: | |
1088 | case CPU_DEAD_FROZEN: | |
31656519 | 1089 | hrtick_clear(cpu_rq(cpu)); |
b328ca18 PZ |
1090 | return NOTIFY_OK; |
1091 | } | |
1092 | ||
1093 | return NOTIFY_DONE; | |
1094 | } | |
1095 | ||
fa748203 | 1096 | static __init void init_hrtick(void) |
b328ca18 PZ |
1097 | { |
1098 | hotcpu_notifier(hotplug_hrtick, 0); | |
1099 | } | |
31656519 PZ |
1100 | #else |
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) | |
1107 | { | |
1108 | hrtimer_start(&rq->hrtick_timer, ns_to_ktime(delay), HRTIMER_MODE_REL); | |
1109 | } | |
b328ca18 | 1110 | |
006c75f1 | 1111 | static inline void init_hrtick(void) |
8f4d37ec | 1112 | { |
8f4d37ec | 1113 | } |
31656519 | 1114 | #endif /* CONFIG_SMP */ |
8f4d37ec | 1115 | |
31656519 | 1116 | static void init_rq_hrtick(struct rq *rq) |
8f4d37ec | 1117 | { |
31656519 PZ |
1118 | #ifdef CONFIG_SMP |
1119 | rq->hrtick_csd_pending = 0; | |
8f4d37ec | 1120 | |
31656519 PZ |
1121 | rq->hrtick_csd.flags = 0; |
1122 | rq->hrtick_csd.func = __hrtick_start; | |
1123 | rq->hrtick_csd.info = rq; | |
1124 | #endif | |
8f4d37ec | 1125 | |
31656519 PZ |
1126 | hrtimer_init(&rq->hrtick_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); |
1127 | rq->hrtick_timer.function = hrtick; | |
ccc7dadf | 1128 | rq->hrtick_timer.cb_mode = HRTIMER_CB_IRQSAFE_PERCPU; |
8f4d37ec | 1129 | } |
006c75f1 | 1130 | #else /* CONFIG_SCHED_HRTICK */ |
8f4d37ec PZ |
1131 | static inline void hrtick_clear(struct rq *rq) |
1132 | { | |
1133 | } | |
1134 | ||
8f4d37ec PZ |
1135 | static inline void init_rq_hrtick(struct rq *rq) |
1136 | { | |
1137 | } | |
1138 | ||
b328ca18 PZ |
1139 | static inline void init_hrtick(void) |
1140 | { | |
1141 | } | |
006c75f1 | 1142 | #endif /* CONFIG_SCHED_HRTICK */ |
8f4d37ec | 1143 | |
c24d20db IM |
1144 | /* |
1145 | * resched_task - mark a task 'to be rescheduled now'. | |
1146 | * | |
1147 | * On UP this means the setting of the need_resched flag, on SMP it | |
1148 | * might also involve a cross-CPU call to trigger the scheduler on | |
1149 | * the target CPU. | |
1150 | */ | |
1151 | #ifdef CONFIG_SMP | |
1152 | ||
1153 | #ifndef tsk_is_polling | |
1154 | #define tsk_is_polling(t) test_tsk_thread_flag(t, TIF_POLLING_NRFLAG) | |
1155 | #endif | |
1156 | ||
31656519 | 1157 | static void resched_task(struct task_struct *p) |
c24d20db IM |
1158 | { |
1159 | int cpu; | |
1160 | ||
1161 | assert_spin_locked(&task_rq(p)->lock); | |
1162 | ||
31656519 | 1163 | if (unlikely(test_tsk_thread_flag(p, TIF_NEED_RESCHED))) |
c24d20db IM |
1164 | return; |
1165 | ||
31656519 | 1166 | set_tsk_thread_flag(p, TIF_NEED_RESCHED); |
c24d20db IM |
1167 | |
1168 | cpu = task_cpu(p); | |
1169 | if (cpu == smp_processor_id()) | |
1170 | return; | |
1171 | ||
1172 | /* NEED_RESCHED must be visible before we test polling */ | |
1173 | smp_mb(); | |
1174 | if (!tsk_is_polling(p)) | |
1175 | smp_send_reschedule(cpu); | |
1176 | } | |
1177 | ||
1178 | static void resched_cpu(int cpu) | |
1179 | { | |
1180 | struct rq *rq = cpu_rq(cpu); | |
1181 | unsigned long flags; | |
1182 | ||
1183 | if (!spin_trylock_irqsave(&rq->lock, flags)) | |
1184 | return; | |
1185 | resched_task(cpu_curr(cpu)); | |
1186 | spin_unlock_irqrestore(&rq->lock, flags); | |
1187 | } | |
06d8308c TG |
1188 | |
1189 | #ifdef CONFIG_NO_HZ | |
1190 | /* | |
1191 | * When add_timer_on() enqueues a timer into the timer wheel of an | |
1192 | * idle CPU then this timer might expire before the next timer event | |
1193 | * which is scheduled to wake up that CPU. In case of a completely | |
1194 | * idle system the next event might even be infinite time into the | |
1195 | * future. wake_up_idle_cpu() ensures that the CPU is woken up and | |
1196 | * leaves the inner idle loop so the newly added timer is taken into | |
1197 | * account when the CPU goes back to idle and evaluates the timer | |
1198 | * wheel for the next timer event. | |
1199 | */ | |
1200 | void wake_up_idle_cpu(int cpu) | |
1201 | { | |
1202 | struct rq *rq = cpu_rq(cpu); | |
1203 | ||
1204 | if (cpu == smp_processor_id()) | |
1205 | return; | |
1206 | ||
1207 | /* | |
1208 | * This is safe, as this function is called with the timer | |
1209 | * wheel base lock of (cpu) held. When the CPU is on the way | |
1210 | * to idle and has not yet set rq->curr to idle then it will | |
1211 | * be serialized on the timer wheel base lock and take the new | |
1212 | * timer into account automatically. | |
1213 | */ | |
1214 | if (rq->curr != rq->idle) | |
1215 | return; | |
1216 | ||
1217 | /* | |
1218 | * We can set TIF_RESCHED on the idle task of the other CPU | |
1219 | * lockless. The worst case is that the other CPU runs the | |
1220 | * idle task through an additional NOOP schedule() | |
1221 | */ | |
1222 | set_tsk_thread_flag(rq->idle, TIF_NEED_RESCHED); | |
1223 | ||
1224 | /* NEED_RESCHED must be visible before we test polling */ | |
1225 | smp_mb(); | |
1226 | if (!tsk_is_polling(rq->idle)) | |
1227 | smp_send_reschedule(cpu); | |
1228 | } | |
6d6bc0ad | 1229 | #endif /* CONFIG_NO_HZ */ |
06d8308c | 1230 | |
6d6bc0ad | 1231 | #else /* !CONFIG_SMP */ |
31656519 | 1232 | static void resched_task(struct task_struct *p) |
c24d20db IM |
1233 | { |
1234 | assert_spin_locked(&task_rq(p)->lock); | |
31656519 | 1235 | set_tsk_need_resched(p); |
c24d20db | 1236 | } |
6d6bc0ad | 1237 | #endif /* CONFIG_SMP */ |
c24d20db | 1238 | |
45bf76df IM |
1239 | #if BITS_PER_LONG == 32 |
1240 | # define WMULT_CONST (~0UL) | |
1241 | #else | |
1242 | # define WMULT_CONST (1UL << 32) | |
1243 | #endif | |
1244 | ||
1245 | #define WMULT_SHIFT 32 | |
1246 | ||
194081eb IM |
1247 | /* |
1248 | * Shift right and round: | |
1249 | */ | |
cf2ab469 | 1250 | #define SRR(x, y) (((x) + (1UL << ((y) - 1))) >> (y)) |
194081eb | 1251 | |
a7be37ac PZ |
1252 | /* |
1253 | * delta *= weight / lw | |
1254 | */ | |
cb1c4fc9 | 1255 | static unsigned long |
45bf76df IM |
1256 | calc_delta_mine(unsigned long delta_exec, unsigned long weight, |
1257 | struct load_weight *lw) | |
1258 | { | |
1259 | u64 tmp; | |
1260 | ||
7a232e03 LJ |
1261 | if (!lw->inv_weight) { |
1262 | if (BITS_PER_LONG > 32 && unlikely(lw->weight >= WMULT_CONST)) | |
1263 | lw->inv_weight = 1; | |
1264 | else | |
1265 | lw->inv_weight = 1 + (WMULT_CONST-lw->weight/2) | |
1266 | / (lw->weight+1); | |
1267 | } | |
45bf76df IM |
1268 | |
1269 | tmp = (u64)delta_exec * weight; | |
1270 | /* | |
1271 | * Check whether we'd overflow the 64-bit multiplication: | |
1272 | */ | |
194081eb | 1273 | if (unlikely(tmp > WMULT_CONST)) |
cf2ab469 | 1274 | tmp = SRR(SRR(tmp, WMULT_SHIFT/2) * lw->inv_weight, |
194081eb IM |
1275 | WMULT_SHIFT/2); |
1276 | else | |
cf2ab469 | 1277 | tmp = SRR(tmp * lw->inv_weight, WMULT_SHIFT); |
45bf76df | 1278 | |
ecf691da | 1279 | return (unsigned long)min(tmp, (u64)(unsigned long)LONG_MAX); |
45bf76df IM |
1280 | } |
1281 | ||
1091985b | 1282 | static inline void update_load_add(struct load_weight *lw, unsigned long inc) |
45bf76df IM |
1283 | { |
1284 | lw->weight += inc; | |
e89996ae | 1285 | lw->inv_weight = 0; |
45bf76df IM |
1286 | } |
1287 | ||
1091985b | 1288 | static inline void update_load_sub(struct load_weight *lw, unsigned long dec) |
45bf76df IM |
1289 | { |
1290 | lw->weight -= dec; | |
e89996ae | 1291 | lw->inv_weight = 0; |
45bf76df IM |
1292 | } |
1293 | ||
2dd73a4f PW |
1294 | /* |
1295 | * To aid in avoiding the subversion of "niceness" due to uneven distribution | |
1296 | * of tasks with abnormal "nice" values across CPUs the contribution that | |
1297 | * each task makes to its run queue's load is weighted according to its | |
41a2d6cf | 1298 | * scheduling class and "nice" value. For SCHED_NORMAL tasks this is just a |
2dd73a4f PW |
1299 | * scaled version of the new time slice allocation that they receive on time |
1300 | * slice expiry etc. | |
1301 | */ | |
1302 | ||
dd41f596 IM |
1303 | #define WEIGHT_IDLEPRIO 2 |
1304 | #define WMULT_IDLEPRIO (1 << 31) | |
1305 | ||
1306 | /* | |
1307 | * Nice levels are multiplicative, with a gentle 10% change for every | |
1308 | * nice level changed. I.e. when a CPU-bound task goes from nice 0 to | |
1309 | * nice 1, it will get ~10% less CPU time than another CPU-bound task | |
1310 | * that remained on nice 0. | |
1311 | * | |
1312 | * The "10% effect" is relative and cumulative: from _any_ nice level, | |
1313 | * if you go up 1 level, it's -10% CPU usage, if you go down 1 level | |
f9153ee6 IM |
1314 | * it's +10% CPU usage. (to achieve that we use a multiplier of 1.25. |
1315 | * If a task goes up by ~10% and another task goes down by ~10% then | |
1316 | * the relative distance between them is ~25%.) | |
dd41f596 IM |
1317 | */ |
1318 | static const int prio_to_weight[40] = { | |
254753dc IM |
1319 | /* -20 */ 88761, 71755, 56483, 46273, 36291, |
1320 | /* -15 */ 29154, 23254, 18705, 14949, 11916, | |
1321 | /* -10 */ 9548, 7620, 6100, 4904, 3906, | |
1322 | /* -5 */ 3121, 2501, 1991, 1586, 1277, | |
1323 | /* 0 */ 1024, 820, 655, 526, 423, | |
1324 | /* 5 */ 335, 272, 215, 172, 137, | |
1325 | /* 10 */ 110, 87, 70, 56, 45, | |
1326 | /* 15 */ 36, 29, 23, 18, 15, | |
dd41f596 IM |
1327 | }; |
1328 | ||
5714d2de IM |
1329 | /* |
1330 | * Inverse (2^32/x) values of the prio_to_weight[] array, precalculated. | |
1331 | * | |
1332 | * In cases where the weight does not change often, we can use the | |
1333 | * precalculated inverse to speed up arithmetics by turning divisions | |
1334 | * into multiplications: | |
1335 | */ | |
dd41f596 | 1336 | static const u32 prio_to_wmult[40] = { |
254753dc IM |
1337 | /* -20 */ 48388, 59856, 76040, 92818, 118348, |
1338 | /* -15 */ 147320, 184698, 229616, 287308, 360437, | |
1339 | /* -10 */ 449829, 563644, 704093, 875809, 1099582, | |
1340 | /* -5 */ 1376151, 1717300, 2157191, 2708050, 3363326, | |
1341 | /* 0 */ 4194304, 5237765, 6557202, 8165337, 10153587, | |
1342 | /* 5 */ 12820798, 15790321, 19976592, 24970740, 31350126, | |
1343 | /* 10 */ 39045157, 49367440, 61356676, 76695844, 95443717, | |
1344 | /* 15 */ 119304647, 148102320, 186737708, 238609294, 286331153, | |
dd41f596 | 1345 | }; |
2dd73a4f | 1346 | |
dd41f596 IM |
1347 | static void activate_task(struct rq *rq, struct task_struct *p, int wakeup); |
1348 | ||
1349 | /* | |
1350 | * runqueue iterator, to support SMP load-balancing between different | |
1351 | * scheduling classes, without having to expose their internal data | |
1352 | * structures to the load-balancing proper: | |
1353 | */ | |
1354 | struct rq_iterator { | |
1355 | void *arg; | |
1356 | struct task_struct *(*start)(void *); | |
1357 | struct task_struct *(*next)(void *); | |
1358 | }; | |
1359 | ||
e1d1484f PW |
1360 | #ifdef CONFIG_SMP |
1361 | static unsigned long | |
1362 | balance_tasks(struct rq *this_rq, int this_cpu, struct rq *busiest, | |
1363 | unsigned long max_load_move, struct sched_domain *sd, | |
1364 | enum cpu_idle_type idle, int *all_pinned, | |
1365 | int *this_best_prio, struct rq_iterator *iterator); | |
1366 | ||
1367 | static int | |
1368 | iter_move_one_task(struct rq *this_rq, int this_cpu, struct rq *busiest, | |
1369 | struct sched_domain *sd, enum cpu_idle_type idle, | |
1370 | struct rq_iterator *iterator); | |
e1d1484f | 1371 | #endif |
dd41f596 | 1372 | |
d842de87 SV |
1373 | #ifdef CONFIG_CGROUP_CPUACCT |
1374 | static void cpuacct_charge(struct task_struct *tsk, u64 cputime); | |
1375 | #else | |
1376 | static inline void cpuacct_charge(struct task_struct *tsk, u64 cputime) {} | |
1377 | #endif | |
1378 | ||
18d95a28 PZ |
1379 | static inline void inc_cpu_load(struct rq *rq, unsigned long load) |
1380 | { | |
1381 | update_load_add(&rq->load, load); | |
1382 | } | |
1383 | ||
1384 | static inline void dec_cpu_load(struct rq *rq, unsigned long load) | |
1385 | { | |
1386 | update_load_sub(&rq->load, load); | |
1387 | } | |
1388 | ||
7940ca36 | 1389 | #if (defined(CONFIG_SMP) && defined(CONFIG_FAIR_GROUP_SCHED)) || defined(CONFIG_RT_GROUP_SCHED) |
eb755805 | 1390 | typedef int (*tg_visitor)(struct task_group *, void *); |
c09595f6 PZ |
1391 | |
1392 | /* | |
1393 | * Iterate the full tree, calling @down when first entering a node and @up when | |
1394 | * leaving it for the final time. | |
1395 | */ | |
eb755805 | 1396 | static int walk_tg_tree(tg_visitor down, tg_visitor up, void *data) |
c09595f6 PZ |
1397 | { |
1398 | struct task_group *parent, *child; | |
eb755805 | 1399 | int ret; |
c09595f6 PZ |
1400 | |
1401 | rcu_read_lock(); | |
1402 | parent = &root_task_group; | |
1403 | down: | |
eb755805 PZ |
1404 | ret = (*down)(parent, data); |
1405 | if (ret) | |
1406 | goto out_unlock; | |
c09595f6 PZ |
1407 | list_for_each_entry_rcu(child, &parent->children, siblings) { |
1408 | parent = child; | |
1409 | goto down; | |
1410 | ||
1411 | up: | |
1412 | continue; | |
1413 | } | |
eb755805 PZ |
1414 | ret = (*up)(parent, data); |
1415 | if (ret) | |
1416 | goto out_unlock; | |
c09595f6 PZ |
1417 | |
1418 | child = parent; | |
1419 | parent = parent->parent; | |
1420 | if (parent) | |
1421 | goto up; | |
eb755805 | 1422 | out_unlock: |
c09595f6 | 1423 | rcu_read_unlock(); |
eb755805 PZ |
1424 | |
1425 | return ret; | |
c09595f6 PZ |
1426 | } |
1427 | ||
eb755805 PZ |
1428 | static int tg_nop(struct task_group *tg, void *data) |
1429 | { | |
1430 | return 0; | |
c09595f6 | 1431 | } |
eb755805 PZ |
1432 | #endif |
1433 | ||
1434 | #ifdef CONFIG_SMP | |
1435 | static unsigned long source_load(int cpu, int type); | |
1436 | static unsigned long target_load(int cpu, int type); | |
1437 | static int task_hot(struct task_struct *p, u64 now, struct sched_domain *sd); | |
1438 | ||
1439 | static unsigned long cpu_avg_load_per_task(int cpu) | |
1440 | { | |
1441 | struct rq *rq = cpu_rq(cpu); | |
1442 | ||
1443 | if (rq->nr_running) | |
1444 | rq->avg_load_per_task = rq->load.weight / rq->nr_running; | |
a2d47777 BS |
1445 | else |
1446 | rq->avg_load_per_task = 0; | |
eb755805 PZ |
1447 | |
1448 | return rq->avg_load_per_task; | |
1449 | } | |
1450 | ||
1451 | #ifdef CONFIG_FAIR_GROUP_SCHED | |
c09595f6 | 1452 | |
c09595f6 PZ |
1453 | static void __set_se_shares(struct sched_entity *se, unsigned long shares); |
1454 | ||
1455 | /* | |
1456 | * Calculate and set the cpu's group shares. | |
1457 | */ | |
1458 | static void | |
ffda12a1 PZ |
1459 | update_group_shares_cpu(struct task_group *tg, int cpu, |
1460 | unsigned long sd_shares, unsigned long sd_rq_weight) | |
18d95a28 | 1461 | { |
c09595f6 PZ |
1462 | unsigned long shares; |
1463 | unsigned long rq_weight; | |
1464 | ||
c8cba857 | 1465 | if (!tg->se[cpu]) |
c09595f6 PZ |
1466 | return; |
1467 | ||
ec4e0e2f | 1468 | rq_weight = tg->cfs_rq[cpu]->rq_weight; |
c8cba857 | 1469 | |
c09595f6 PZ |
1470 | /* |
1471 | * \Sum shares * rq_weight | |
1472 | * shares = ----------------------- | |
1473 | * \Sum rq_weight | |
1474 | * | |
1475 | */ | |
ec4e0e2f | 1476 | shares = (sd_shares * rq_weight) / sd_rq_weight; |
ffda12a1 | 1477 | shares = clamp_t(unsigned long, shares, MIN_SHARES, MAX_SHARES); |
c09595f6 | 1478 | |
ffda12a1 PZ |
1479 | if (abs(shares - tg->se[cpu]->load.weight) > |
1480 | sysctl_sched_shares_thresh) { | |
1481 | struct rq *rq = cpu_rq(cpu); | |
1482 | unsigned long flags; | |
c09595f6 | 1483 | |
ffda12a1 | 1484 | spin_lock_irqsave(&rq->lock, flags); |
ec4e0e2f | 1485 | tg->cfs_rq[cpu]->shares = shares; |
c09595f6 | 1486 | |
ffda12a1 PZ |
1487 | __set_se_shares(tg->se[cpu], shares); |
1488 | spin_unlock_irqrestore(&rq->lock, flags); | |
1489 | } | |
18d95a28 | 1490 | } |
c09595f6 PZ |
1491 | |
1492 | /* | |
c8cba857 PZ |
1493 | * Re-compute the task group their per cpu shares over the given domain. |
1494 | * This needs to be done in a bottom-up fashion because the rq weight of a | |
1495 | * parent group depends on the shares of its child groups. | |
c09595f6 | 1496 | */ |
eb755805 | 1497 | static int tg_shares_up(struct task_group *tg, void *data) |
c09595f6 | 1498 | { |
ec4e0e2f | 1499 | unsigned long weight, rq_weight = 0; |
c8cba857 | 1500 | unsigned long shares = 0; |
eb755805 | 1501 | struct sched_domain *sd = data; |
c8cba857 | 1502 | int i; |
c09595f6 | 1503 | |
c8cba857 | 1504 | for_each_cpu_mask(i, sd->span) { |
ec4e0e2f KC |
1505 | /* |
1506 | * If there are currently no tasks on the cpu pretend there | |
1507 | * is one of average load so that when a new task gets to | |
1508 | * run here it will not get delayed by group starvation. | |
1509 | */ | |
1510 | weight = tg->cfs_rq[i]->load.weight; | |
1511 | if (!weight) | |
1512 | weight = NICE_0_LOAD; | |
1513 | ||
1514 | tg->cfs_rq[i]->rq_weight = weight; | |
1515 | rq_weight += weight; | |
c8cba857 | 1516 | shares += tg->cfs_rq[i]->shares; |
c09595f6 | 1517 | } |
c09595f6 | 1518 | |
c8cba857 PZ |
1519 | if ((!shares && rq_weight) || shares > tg->shares) |
1520 | shares = tg->shares; | |
1521 | ||
1522 | if (!sd->parent || !(sd->parent->flags & SD_LOAD_BALANCE)) | |
1523 | shares = tg->shares; | |
c09595f6 | 1524 | |
ffda12a1 PZ |
1525 | for_each_cpu_mask(i, sd->span) |
1526 | update_group_shares_cpu(tg, i, shares, rq_weight); | |
eb755805 PZ |
1527 | |
1528 | return 0; | |
c09595f6 PZ |
1529 | } |
1530 | ||
1531 | /* | |
c8cba857 PZ |
1532 | * Compute the cpu's hierarchical load factor for each task group. |
1533 | * This needs to be done in a top-down fashion because the load of a child | |
1534 | * group is a fraction of its parents load. | |
c09595f6 | 1535 | */ |
eb755805 | 1536 | static int tg_load_down(struct task_group *tg, void *data) |
c09595f6 | 1537 | { |
c8cba857 | 1538 | unsigned long load; |
eb755805 | 1539 | long cpu = (long)data; |
c09595f6 | 1540 | |
c8cba857 PZ |
1541 | if (!tg->parent) { |
1542 | load = cpu_rq(cpu)->load.weight; | |
1543 | } else { | |
1544 | load = tg->parent->cfs_rq[cpu]->h_load; | |
1545 | load *= tg->cfs_rq[cpu]->shares; | |
1546 | load /= tg->parent->cfs_rq[cpu]->load.weight + 1; | |
1547 | } | |
c09595f6 | 1548 | |
c8cba857 | 1549 | tg->cfs_rq[cpu]->h_load = load; |
c09595f6 | 1550 | |
eb755805 | 1551 | return 0; |
c09595f6 PZ |
1552 | } |
1553 | ||
c8cba857 | 1554 | static void update_shares(struct sched_domain *sd) |
4d8d595d | 1555 | { |
2398f2c6 PZ |
1556 | u64 now = cpu_clock(raw_smp_processor_id()); |
1557 | s64 elapsed = now - sd->last_update; | |
1558 | ||
1559 | if (elapsed >= (s64)(u64)sysctl_sched_shares_ratelimit) { | |
1560 | sd->last_update = now; | |
eb755805 | 1561 | walk_tg_tree(tg_nop, tg_shares_up, sd); |
2398f2c6 | 1562 | } |
4d8d595d PZ |
1563 | } |
1564 | ||
3e5459b4 PZ |
1565 | static void update_shares_locked(struct rq *rq, struct sched_domain *sd) |
1566 | { | |
1567 | spin_unlock(&rq->lock); | |
1568 | update_shares(sd); | |
1569 | spin_lock(&rq->lock); | |
1570 | } | |
1571 | ||
eb755805 | 1572 | static void update_h_load(long cpu) |
c09595f6 | 1573 | { |
eb755805 | 1574 | walk_tg_tree(tg_load_down, tg_nop, (void *)cpu); |
c09595f6 PZ |
1575 | } |
1576 | ||
c09595f6 PZ |
1577 | #else |
1578 | ||
c8cba857 | 1579 | static inline void update_shares(struct sched_domain *sd) |
4d8d595d PZ |
1580 | { |
1581 | } | |
1582 | ||
3e5459b4 PZ |
1583 | static inline void update_shares_locked(struct rq *rq, struct sched_domain *sd) |
1584 | { | |
1585 | } | |
1586 | ||
18d95a28 PZ |
1587 | #endif |
1588 | ||
18d95a28 PZ |
1589 | #endif |
1590 | ||
30432094 | 1591 | #ifdef CONFIG_FAIR_GROUP_SCHED |
34e83e85 IM |
1592 | static void cfs_rq_set_shares(struct cfs_rq *cfs_rq, unsigned long shares) |
1593 | { | |
30432094 | 1594 | #ifdef CONFIG_SMP |
34e83e85 IM |
1595 | cfs_rq->shares = shares; |
1596 | #endif | |
1597 | } | |
30432094 | 1598 | #endif |
e7693a36 | 1599 | |
dd41f596 | 1600 | #include "sched_stats.h" |
dd41f596 | 1601 | #include "sched_idletask.c" |
5522d5d5 IM |
1602 | #include "sched_fair.c" |
1603 | #include "sched_rt.c" | |
dd41f596 IM |
1604 | #ifdef CONFIG_SCHED_DEBUG |
1605 | # include "sched_debug.c" | |
1606 | #endif | |
1607 | ||
1608 | #define sched_class_highest (&rt_sched_class) | |
1f11eb6a GH |
1609 | #define for_each_class(class) \ |
1610 | for (class = sched_class_highest; class; class = class->next) | |
dd41f596 | 1611 | |
c09595f6 | 1612 | static void inc_nr_running(struct rq *rq) |
9c217245 IM |
1613 | { |
1614 | rq->nr_running++; | |
9c217245 IM |
1615 | } |
1616 | ||
c09595f6 | 1617 | static void dec_nr_running(struct rq *rq) |
9c217245 IM |
1618 | { |
1619 | rq->nr_running--; | |
9c217245 IM |
1620 | } |
1621 | ||
45bf76df IM |
1622 | static void set_load_weight(struct task_struct *p) |
1623 | { | |
1624 | if (task_has_rt_policy(p)) { | |
dd41f596 IM |
1625 | p->se.load.weight = prio_to_weight[0] * 2; |
1626 | p->se.load.inv_weight = prio_to_wmult[0] >> 1; | |
1627 | return; | |
1628 | } | |
45bf76df | 1629 | |
dd41f596 IM |
1630 | /* |
1631 | * SCHED_IDLE tasks get minimal weight: | |
1632 | */ | |
1633 | if (p->policy == SCHED_IDLE) { | |
1634 | p->se.load.weight = WEIGHT_IDLEPRIO; | |
1635 | p->se.load.inv_weight = WMULT_IDLEPRIO; | |
1636 | return; | |
1637 | } | |
71f8bd46 | 1638 | |
dd41f596 IM |
1639 | p->se.load.weight = prio_to_weight[p->static_prio - MAX_RT_PRIO]; |
1640 | p->se.load.inv_weight = prio_to_wmult[p->static_prio - MAX_RT_PRIO]; | |
71f8bd46 IM |
1641 | } |
1642 | ||
2087a1ad GH |
1643 | static void update_avg(u64 *avg, u64 sample) |
1644 | { | |
1645 | s64 diff = sample - *avg; | |
1646 | *avg += diff >> 3; | |
1647 | } | |
1648 | ||
8159f87e | 1649 | static void enqueue_task(struct rq *rq, struct task_struct *p, int wakeup) |
71f8bd46 | 1650 | { |
dd41f596 | 1651 | sched_info_queued(p); |
fd390f6a | 1652 | p->sched_class->enqueue_task(rq, p, wakeup); |
dd41f596 | 1653 | p->se.on_rq = 1; |
71f8bd46 IM |
1654 | } |
1655 | ||
69be72c1 | 1656 | static void dequeue_task(struct rq *rq, struct task_struct *p, int sleep) |
71f8bd46 | 1657 | { |
2087a1ad GH |
1658 | if (sleep && p->se.last_wakeup) { |
1659 | update_avg(&p->se.avg_overlap, | |
1660 | p->se.sum_exec_runtime - p->se.last_wakeup); | |
1661 | p->se.last_wakeup = 0; | |
1662 | } | |
1663 | ||
46ac22ba | 1664 | sched_info_dequeued(p); |
f02231e5 | 1665 | p->sched_class->dequeue_task(rq, p, sleep); |
dd41f596 | 1666 | p->se.on_rq = 0; |
71f8bd46 IM |
1667 | } |
1668 | ||
14531189 | 1669 | /* |
dd41f596 | 1670 | * __normal_prio - return the priority that is based on the static prio |
14531189 | 1671 | */ |
14531189 IM |
1672 | static inline int __normal_prio(struct task_struct *p) |
1673 | { | |
dd41f596 | 1674 | return p->static_prio; |
14531189 IM |
1675 | } |
1676 | ||
b29739f9 IM |
1677 | /* |
1678 | * Calculate the expected normal priority: i.e. priority | |
1679 | * without taking RT-inheritance into account. Might be | |
1680 | * boosted by interactivity modifiers. Changes upon fork, | |
1681 | * setprio syscalls, and whenever the interactivity | |
1682 | * estimator recalculates. | |
1683 | */ | |
36c8b586 | 1684 | static inline int normal_prio(struct task_struct *p) |
b29739f9 IM |
1685 | { |
1686 | int prio; | |
1687 | ||
e05606d3 | 1688 | if (task_has_rt_policy(p)) |
b29739f9 IM |
1689 | prio = MAX_RT_PRIO-1 - p->rt_priority; |
1690 | else | |
1691 | prio = __normal_prio(p); | |
1692 | return prio; | |
1693 | } | |
1694 | ||
1695 | /* | |
1696 | * Calculate the current priority, i.e. the priority | |
1697 | * taken into account by the scheduler. This value might | |
1698 | * be boosted by RT tasks, or might be boosted by | |
1699 | * interactivity modifiers. Will be RT if the task got | |
1700 | * RT-boosted. If not then it returns p->normal_prio. | |
1701 | */ | |
36c8b586 | 1702 | static int effective_prio(struct task_struct *p) |
b29739f9 IM |
1703 | { |
1704 | p->normal_prio = normal_prio(p); | |
1705 | /* | |
1706 | * If we are RT tasks or we were boosted to RT priority, | |
1707 | * keep the priority unchanged. Otherwise, update priority | |
1708 | * to the normal priority: | |
1709 | */ | |
1710 | if (!rt_prio(p->prio)) | |
1711 | return p->normal_prio; | |
1712 | return p->prio; | |
1713 | } | |
1714 | ||
1da177e4 | 1715 | /* |
dd41f596 | 1716 | * activate_task - move a task to the runqueue. |
1da177e4 | 1717 | */ |
dd41f596 | 1718 | static void activate_task(struct rq *rq, struct task_struct *p, int wakeup) |
1da177e4 | 1719 | { |
d9514f6c | 1720 | if (task_contributes_to_load(p)) |
dd41f596 | 1721 | rq->nr_uninterruptible--; |
1da177e4 | 1722 | |
8159f87e | 1723 | enqueue_task(rq, p, wakeup); |
c09595f6 | 1724 | inc_nr_running(rq); |
1da177e4 LT |
1725 | } |
1726 | ||
1da177e4 LT |
1727 | /* |
1728 | * deactivate_task - remove a task from the runqueue. | |
1729 | */ | |
2e1cb74a | 1730 | static void deactivate_task(struct rq *rq, struct task_struct *p, int sleep) |
1da177e4 | 1731 | { |
d9514f6c | 1732 | if (task_contributes_to_load(p)) |
dd41f596 IM |
1733 | rq->nr_uninterruptible++; |
1734 | ||
69be72c1 | 1735 | dequeue_task(rq, p, sleep); |
c09595f6 | 1736 | dec_nr_running(rq); |
1da177e4 LT |
1737 | } |
1738 | ||
1da177e4 LT |
1739 | /** |
1740 | * task_curr - is this task currently executing on a CPU? | |
1741 | * @p: the task in question. | |
1742 | */ | |
36c8b586 | 1743 | inline int task_curr(const struct task_struct *p) |
1da177e4 LT |
1744 | { |
1745 | return cpu_curr(task_cpu(p)) == p; | |
1746 | } | |
1747 | ||
dd41f596 IM |
1748 | static inline void __set_task_cpu(struct task_struct *p, unsigned int cpu) |
1749 | { | |
6f505b16 | 1750 | set_task_rq(p, cpu); |
dd41f596 | 1751 | #ifdef CONFIG_SMP |
ce96b5ac DA |
1752 | /* |
1753 | * After ->cpu is set up to a new value, task_rq_lock(p, ...) can be | |
1754 | * successfuly executed on another CPU. We must ensure that updates of | |
1755 | * per-task data have been completed by this moment. | |
1756 | */ | |
1757 | smp_wmb(); | |
dd41f596 | 1758 | task_thread_info(p)->cpu = cpu; |
dd41f596 | 1759 | #endif |
2dd73a4f PW |
1760 | } |
1761 | ||
cb469845 SR |
1762 | static inline void check_class_changed(struct rq *rq, struct task_struct *p, |
1763 | const struct sched_class *prev_class, | |
1764 | int oldprio, int running) | |
1765 | { | |
1766 | if (prev_class != p->sched_class) { | |
1767 | if (prev_class->switched_from) | |
1768 | prev_class->switched_from(rq, p, running); | |
1769 | p->sched_class->switched_to(rq, p, running); | |
1770 | } else | |
1771 | p->sched_class->prio_changed(rq, p, oldprio, running); | |
1772 | } | |
1773 | ||
1da177e4 | 1774 | #ifdef CONFIG_SMP |
c65cc870 | 1775 | |
e958b360 TG |
1776 | /* Used instead of source_load when we know the type == 0 */ |
1777 | static unsigned long weighted_cpuload(const int cpu) | |
1778 | { | |
1779 | return cpu_rq(cpu)->load.weight; | |
1780 | } | |
1781 | ||
cc367732 IM |
1782 | /* |
1783 | * Is this task likely cache-hot: | |
1784 | */ | |
e7693a36 | 1785 | static int |
cc367732 IM |
1786 | task_hot(struct task_struct *p, u64 now, struct sched_domain *sd) |
1787 | { | |
1788 | s64 delta; | |
1789 | ||
f540a608 IM |
1790 | /* |
1791 | * Buddy candidates are cache hot: | |
1792 | */ | |
4793241b PZ |
1793 | if (sched_feat(CACHE_HOT_BUDDY) && |
1794 | (&p->se == cfs_rq_of(&p->se)->next || | |
1795 | &p->se == cfs_rq_of(&p->se)->last)) | |
f540a608 IM |
1796 | return 1; |
1797 | ||
cc367732 IM |
1798 | if (p->sched_class != &fair_sched_class) |
1799 | return 0; | |
1800 | ||
6bc1665b IM |
1801 | if (sysctl_sched_migration_cost == -1) |
1802 | return 1; | |
1803 | if (sysctl_sched_migration_cost == 0) | |
1804 | return 0; | |
1805 | ||
cc367732 IM |
1806 | delta = now - p->se.exec_start; |
1807 | ||
1808 | return delta < (s64)sysctl_sched_migration_cost; | |
1809 | } | |
1810 | ||
1811 | ||
dd41f596 | 1812 | void set_task_cpu(struct task_struct *p, unsigned int new_cpu) |
c65cc870 | 1813 | { |
dd41f596 IM |
1814 | int old_cpu = task_cpu(p); |
1815 | struct rq *old_rq = cpu_rq(old_cpu), *new_rq = cpu_rq(new_cpu); | |
2830cf8c SV |
1816 | struct cfs_rq *old_cfsrq = task_cfs_rq(p), |
1817 | *new_cfsrq = cpu_cfs_rq(old_cfsrq, new_cpu); | |
bbdba7c0 | 1818 | u64 clock_offset; |
dd41f596 IM |
1819 | |
1820 | clock_offset = old_rq->clock - new_rq->clock; | |
6cfb0d5d IM |
1821 | |
1822 | #ifdef CONFIG_SCHEDSTATS | |
1823 | if (p->se.wait_start) | |
1824 | p->se.wait_start -= clock_offset; | |
dd41f596 IM |
1825 | if (p->se.sleep_start) |
1826 | p->se.sleep_start -= clock_offset; | |
1827 | if (p->se.block_start) | |
1828 | p->se.block_start -= clock_offset; | |
cc367732 IM |
1829 | if (old_cpu != new_cpu) { |
1830 | schedstat_inc(p, se.nr_migrations); | |
1831 | if (task_hot(p, old_rq->clock, NULL)) | |
1832 | schedstat_inc(p, se.nr_forced2_migrations); | |
1833 | } | |
6cfb0d5d | 1834 | #endif |
2830cf8c SV |
1835 | p->se.vruntime -= old_cfsrq->min_vruntime - |
1836 | new_cfsrq->min_vruntime; | |
dd41f596 IM |
1837 | |
1838 | __set_task_cpu(p, new_cpu); | |
c65cc870 IM |
1839 | } |
1840 | ||
70b97a7f | 1841 | struct migration_req { |
1da177e4 | 1842 | struct list_head list; |
1da177e4 | 1843 | |
36c8b586 | 1844 | struct task_struct *task; |
1da177e4 LT |
1845 | int dest_cpu; |
1846 | ||
1da177e4 | 1847 | struct completion done; |
70b97a7f | 1848 | }; |
1da177e4 LT |
1849 | |
1850 | /* | |
1851 | * The task's runqueue lock must be held. | |
1852 | * Returns true if you have to wait for migration thread. | |
1853 | */ | |
36c8b586 | 1854 | static int |
70b97a7f | 1855 | migrate_task(struct task_struct *p, int dest_cpu, struct migration_req *req) |
1da177e4 | 1856 | { |
70b97a7f | 1857 | struct rq *rq = task_rq(p); |
1da177e4 LT |
1858 | |
1859 | /* | |
1860 | * If the task is not on a runqueue (and not running), then | |
1861 | * it is sufficient to simply update the task's cpu field. | |
1862 | */ | |
dd41f596 | 1863 | if (!p->se.on_rq && !task_running(rq, p)) { |
1da177e4 LT |
1864 | set_task_cpu(p, dest_cpu); |
1865 | return 0; | |
1866 | } | |
1867 | ||
1868 | init_completion(&req->done); | |
1da177e4 LT |
1869 | req->task = p; |
1870 | req->dest_cpu = dest_cpu; | |
1871 | list_add(&req->list, &rq->migration_queue); | |
48f24c4d | 1872 | |
1da177e4 LT |
1873 | return 1; |
1874 | } | |
1875 | ||
1876 | /* | |
1877 | * wait_task_inactive - wait for a thread to unschedule. | |
1878 | * | |
85ba2d86 RM |
1879 | * If @match_state is nonzero, it's the @p->state value just checked and |
1880 | * not expected to change. If it changes, i.e. @p might have woken up, | |
1881 | * then return zero. When we succeed in waiting for @p to be off its CPU, | |
1882 | * we return a positive number (its total switch count). If a second call | |
1883 | * a short while later returns the same number, the caller can be sure that | |
1884 | * @p has remained unscheduled the whole time. | |
1885 | * | |
1da177e4 LT |
1886 | * The caller must ensure that the task *will* unschedule sometime soon, |
1887 | * else this function might spin for a *long* time. This function can't | |
1888 | * be called with interrupts off, or it may introduce deadlock with | |
1889 | * smp_call_function() if an IPI is sent by the same process we are | |
1890 | * waiting to become inactive. | |
1891 | */ | |
85ba2d86 | 1892 | unsigned long wait_task_inactive(struct task_struct *p, long match_state) |
1da177e4 LT |
1893 | { |
1894 | unsigned long flags; | |
dd41f596 | 1895 | int running, on_rq; |
85ba2d86 | 1896 | unsigned long ncsw; |
70b97a7f | 1897 | struct rq *rq; |
1da177e4 | 1898 | |
3a5c359a AK |
1899 | for (;;) { |
1900 | /* | |
1901 | * We do the initial early heuristics without holding | |
1902 | * any task-queue locks at all. We'll only try to get | |
1903 | * the runqueue lock when things look like they will | |
1904 | * work out! | |
1905 | */ | |
1906 | rq = task_rq(p); | |
fa490cfd | 1907 | |
3a5c359a AK |
1908 | /* |
1909 | * If the task is actively running on another CPU | |
1910 | * still, just relax and busy-wait without holding | |
1911 | * any locks. | |
1912 | * | |
1913 | * NOTE! Since we don't hold any locks, it's not | |
1914 | * even sure that "rq" stays as the right runqueue! | |
1915 | * But we don't care, since "task_running()" will | |
1916 | * return false if the runqueue has changed and p | |
1917 | * is actually now running somewhere else! | |
1918 | */ | |
85ba2d86 RM |
1919 | while (task_running(rq, p)) { |
1920 | if (match_state && unlikely(p->state != match_state)) | |
1921 | return 0; | |
3a5c359a | 1922 | cpu_relax(); |
85ba2d86 | 1923 | } |
fa490cfd | 1924 | |
3a5c359a AK |
1925 | /* |
1926 | * Ok, time to look more closely! We need the rq | |
1927 | * lock now, to be *sure*. If we're wrong, we'll | |
1928 | * just go back and repeat. | |
1929 | */ | |
1930 | rq = task_rq_lock(p, &flags); | |
0a16b607 | 1931 | trace_sched_wait_task(rq, p); |
3a5c359a AK |
1932 | running = task_running(rq, p); |
1933 | on_rq = p->se.on_rq; | |
85ba2d86 | 1934 | ncsw = 0; |
f31e11d8 | 1935 | if (!match_state || p->state == match_state) |
93dcf55f | 1936 | ncsw = p->nvcsw | LONG_MIN; /* sets MSB */ |
3a5c359a | 1937 | task_rq_unlock(rq, &flags); |
fa490cfd | 1938 | |
85ba2d86 RM |
1939 | /* |
1940 | * If it changed from the expected state, bail out now. | |
1941 | */ | |
1942 | if (unlikely(!ncsw)) | |
1943 | break; | |
1944 | ||
3a5c359a AK |
1945 | /* |
1946 | * Was it really running after all now that we | |
1947 | * checked with the proper locks actually held? | |
1948 | * | |
1949 | * Oops. Go back and try again.. | |
1950 | */ | |
1951 | if (unlikely(running)) { | |
1952 | cpu_relax(); | |
1953 | continue; | |
1954 | } | |
fa490cfd | 1955 | |
3a5c359a AK |
1956 | /* |
1957 | * It's not enough that it's not actively running, | |
1958 | * it must be off the runqueue _entirely_, and not | |
1959 | * preempted! | |
1960 | * | |
1961 | * So if it wa still runnable (but just not actively | |
1962 | * running right now), it's preempted, and we should | |
1963 | * yield - it could be a while. | |
1964 | */ | |
1965 | if (unlikely(on_rq)) { | |
1966 | schedule_timeout_uninterruptible(1); | |
1967 | continue; | |
1968 | } | |
fa490cfd | 1969 | |
3a5c359a AK |
1970 | /* |
1971 | * Ahh, all good. It wasn't running, and it wasn't | |
1972 | * runnable, which means that it will never become | |
1973 | * running in the future either. We're all done! | |
1974 | */ | |
1975 | break; | |
1976 | } | |
85ba2d86 RM |
1977 | |
1978 | return ncsw; | |
1da177e4 LT |
1979 | } |
1980 | ||
1981 | /*** | |
1982 | * kick_process - kick a running thread to enter/exit the kernel | |
1983 | * @p: the to-be-kicked thread | |
1984 | * | |
1985 | * Cause a process which is running on another CPU to enter | |
1986 | * kernel-mode, without any delay. (to get signals handled.) | |
1987 | * | |
1988 | * NOTE: this function doesnt have to take the runqueue lock, | |
1989 | * because all it wants to ensure is that the remote task enters | |
1990 | * the kernel. If the IPI races and the task has been migrated | |
1991 | * to another CPU then no harm is done and the purpose has been | |
1992 | * achieved as well. | |
1993 | */ | |
36c8b586 | 1994 | void kick_process(struct task_struct *p) |
1da177e4 LT |
1995 | { |
1996 | int cpu; | |
1997 | ||
1998 | preempt_disable(); | |
1999 | cpu = task_cpu(p); | |
2000 | if ((cpu != smp_processor_id()) && task_curr(p)) | |
2001 | smp_send_reschedule(cpu); | |
2002 | preempt_enable(); | |
2003 | } | |
2004 | ||
2005 | /* | |
2dd73a4f PW |
2006 | * Return a low guess at the load of a migration-source cpu weighted |
2007 | * according to the scheduling class and "nice" value. | |
1da177e4 LT |
2008 | * |
2009 | * We want to under-estimate the load of migration sources, to | |
2010 | * balance conservatively. | |
2011 | */ | |
a9957449 | 2012 | static unsigned long source_load(int cpu, int type) |
1da177e4 | 2013 | { |
70b97a7f | 2014 | struct rq *rq = cpu_rq(cpu); |
dd41f596 | 2015 | unsigned long total = weighted_cpuload(cpu); |
2dd73a4f | 2016 | |
93b75217 | 2017 | if (type == 0 || !sched_feat(LB_BIAS)) |
dd41f596 | 2018 | return total; |
b910472d | 2019 | |
dd41f596 | 2020 | return min(rq->cpu_load[type-1], total); |
1da177e4 LT |
2021 | } |
2022 | ||
2023 | /* | |
2dd73a4f PW |
2024 | * Return a high guess at the load of a migration-target cpu weighted |
2025 | * according to the scheduling class and "nice" value. | |
1da177e4 | 2026 | */ |
a9957449 | 2027 | static unsigned long target_load(int cpu, int type) |
1da177e4 | 2028 | { |
70b97a7f | 2029 | struct rq *rq = cpu_rq(cpu); |
dd41f596 | 2030 | unsigned long total = weighted_cpuload(cpu); |
2dd73a4f | 2031 | |
93b75217 | 2032 | if (type == 0 || !sched_feat(LB_BIAS)) |
dd41f596 | 2033 | return total; |
3b0bd9bc | 2034 | |
dd41f596 | 2035 | return max(rq->cpu_load[type-1], total); |
2dd73a4f PW |
2036 | } |
2037 | ||
147cbb4b NP |
2038 | /* |
2039 | * find_idlest_group finds and returns the least busy CPU group within the | |
2040 | * domain. | |
2041 | */ | |
2042 | static struct sched_group * | |
2043 | find_idlest_group(struct sched_domain *sd, struct task_struct *p, int this_cpu) | |
2044 | { | |
2045 | struct sched_group *idlest = NULL, *this = NULL, *group = sd->groups; | |
2046 | unsigned long min_load = ULONG_MAX, this_load = 0; | |
2047 | int load_idx = sd->forkexec_idx; | |
2048 | int imbalance = 100 + (sd->imbalance_pct-100)/2; | |
2049 | ||
2050 | do { | |
2051 | unsigned long load, avg_load; | |
2052 | int local_group; | |
2053 | int i; | |
2054 | ||
da5a5522 BD |
2055 | /* Skip over this group if it has no CPUs allowed */ |
2056 | if (!cpus_intersects(group->cpumask, p->cpus_allowed)) | |
3a5c359a | 2057 | continue; |
da5a5522 | 2058 | |
147cbb4b | 2059 | local_group = cpu_isset(this_cpu, group->cpumask); |
147cbb4b NP |
2060 | |
2061 | /* Tally up the load of all CPUs in the group */ | |
2062 | avg_load = 0; | |
2063 | ||
abcd083a | 2064 | for_each_cpu(i, &group->cpumask) { |
147cbb4b NP |
2065 | /* Bias balancing toward cpus of our domain */ |
2066 | if (local_group) | |
2067 | load = source_load(i, load_idx); | |
2068 | else | |
2069 | load = target_load(i, load_idx); | |
2070 | ||
2071 | avg_load += load; | |
2072 | } | |
2073 | ||
2074 | /* Adjust by relative CPU power of the group */ | |
5517d86b ED |
2075 | avg_load = sg_div_cpu_power(group, |
2076 | avg_load * SCHED_LOAD_SCALE); | |
147cbb4b NP |
2077 | |
2078 | if (local_group) { | |
2079 | this_load = avg_load; | |
2080 | this = group; | |
2081 | } else if (avg_load < min_load) { | |
2082 | min_load = avg_load; | |
2083 | idlest = group; | |
2084 | } | |
3a5c359a | 2085 | } while (group = group->next, group != sd->groups); |
147cbb4b NP |
2086 | |
2087 | if (!idlest || 100*this_load < imbalance*min_load) | |
2088 | return NULL; | |
2089 | return idlest; | |
2090 | } | |
2091 | ||
2092 | /* | |
0feaece9 | 2093 | * find_idlest_cpu - find the idlest cpu among the cpus in group. |
147cbb4b | 2094 | */ |
95cdf3b7 | 2095 | static int |
7c16ec58 MT |
2096 | find_idlest_cpu(struct sched_group *group, struct task_struct *p, int this_cpu, |
2097 | cpumask_t *tmp) | |
147cbb4b NP |
2098 | { |
2099 | unsigned long load, min_load = ULONG_MAX; | |
2100 | int idlest = -1; | |
2101 | int i; | |
2102 | ||
da5a5522 | 2103 | /* Traverse only the allowed CPUs */ |
7c16ec58 | 2104 | cpus_and(*tmp, group->cpumask, p->cpus_allowed); |
da5a5522 | 2105 | |
abcd083a | 2106 | for_each_cpu(i, tmp) { |
2dd73a4f | 2107 | load = weighted_cpuload(i); |
147cbb4b NP |
2108 | |
2109 | if (load < min_load || (load == min_load && i == this_cpu)) { | |
2110 | min_load = load; | |
2111 | idlest = i; | |
2112 | } | |
2113 | } | |
2114 | ||
2115 | return idlest; | |
2116 | } | |
2117 | ||
476d139c NP |
2118 | /* |
2119 | * sched_balance_self: balance the current task (running on cpu) in domains | |
2120 | * that have the 'flag' flag set. In practice, this is SD_BALANCE_FORK and | |
2121 | * SD_BALANCE_EXEC. | |
2122 | * | |
2123 | * Balance, ie. select the least loaded group. | |
2124 | * | |
2125 | * Returns the target CPU number, or the same CPU if no balancing is needed. | |
2126 | * | |
2127 | * preempt must be disabled. | |
2128 | */ | |
2129 | static int sched_balance_self(int cpu, int flag) | |
2130 | { | |
2131 | struct task_struct *t = current; | |
2132 | struct sched_domain *tmp, *sd = NULL; | |
147cbb4b | 2133 | |
c96d145e | 2134 | for_each_domain(cpu, tmp) { |
9761eea8 IM |
2135 | /* |
2136 | * If power savings logic is enabled for a domain, stop there. | |
2137 | */ | |
5c45bf27 SS |
2138 | if (tmp->flags & SD_POWERSAVINGS_BALANCE) |
2139 | break; | |
476d139c NP |
2140 | if (tmp->flags & flag) |
2141 | sd = tmp; | |
c96d145e | 2142 | } |
476d139c | 2143 | |
039a1c41 PZ |
2144 | if (sd) |
2145 | update_shares(sd); | |
2146 | ||
476d139c | 2147 | while (sd) { |
7c16ec58 | 2148 | cpumask_t span, tmpmask; |
476d139c | 2149 | struct sched_group *group; |
1a848870 SS |
2150 | int new_cpu, weight; |
2151 | ||
2152 | if (!(sd->flags & flag)) { | |
2153 | sd = sd->child; | |
2154 | continue; | |
2155 | } | |
476d139c NP |
2156 | |
2157 | span = sd->span; | |
2158 | group = find_idlest_group(sd, t, cpu); | |
1a848870 SS |
2159 | if (!group) { |
2160 | sd = sd->child; | |
2161 | continue; | |
2162 | } | |
476d139c | 2163 | |
7c16ec58 | 2164 | new_cpu = find_idlest_cpu(group, t, cpu, &tmpmask); |
1a848870 SS |
2165 | if (new_cpu == -1 || new_cpu == cpu) { |
2166 | /* Now try balancing at a lower domain level of cpu */ | |
2167 | sd = sd->child; | |
2168 | continue; | |
2169 | } | |
476d139c | 2170 | |
1a848870 | 2171 | /* Now try balancing at a lower domain level of new_cpu */ |
476d139c | 2172 | cpu = new_cpu; |
476d139c NP |
2173 | sd = NULL; |
2174 | weight = cpus_weight(span); | |
2175 | for_each_domain(cpu, tmp) { | |
2176 | if (weight <= cpus_weight(tmp->span)) | |
2177 | break; | |
2178 | if (tmp->flags & flag) | |
2179 | sd = tmp; | |
2180 | } | |
2181 | /* while loop will break here if sd == NULL */ | |
2182 | } | |
2183 | ||
2184 | return cpu; | |
2185 | } | |
2186 | ||
2187 | #endif /* CONFIG_SMP */ | |
1da177e4 | 2188 | |
1da177e4 LT |
2189 | /*** |
2190 | * try_to_wake_up - wake up a thread | |
2191 | * @p: the to-be-woken-up thread | |
2192 | * @state: the mask of task states that can be woken | |
2193 | * @sync: do a synchronous wakeup? | |
2194 | * | |
2195 | * Put it on the run-queue if it's not already there. The "current" | |
2196 | * thread is always on the run-queue (except when the actual | |
2197 | * re-schedule is in progress), and as such you're allowed to do | |
2198 | * the simpler "current->state = TASK_RUNNING" to mark yourself | |
2199 | * runnable without the overhead of this. | |
2200 | * | |
2201 | * returns failure only if the task is already active. | |
2202 | */ | |
36c8b586 | 2203 | static int try_to_wake_up(struct task_struct *p, unsigned int state, int sync) |
1da177e4 | 2204 | { |
cc367732 | 2205 | int cpu, orig_cpu, this_cpu, success = 0; |
1da177e4 LT |
2206 | unsigned long flags; |
2207 | long old_state; | |
70b97a7f | 2208 | struct rq *rq; |
1da177e4 | 2209 | |
b85d0667 IM |
2210 | if (!sched_feat(SYNC_WAKEUPS)) |
2211 | sync = 0; | |
2212 | ||
2398f2c6 PZ |
2213 | #ifdef CONFIG_SMP |
2214 | if (sched_feat(LB_WAKEUP_UPDATE)) { | |
2215 | struct sched_domain *sd; | |
2216 | ||
2217 | this_cpu = raw_smp_processor_id(); | |
2218 | cpu = task_cpu(p); | |
2219 | ||
2220 | for_each_domain(this_cpu, sd) { | |
2221 | if (cpu_isset(cpu, sd->span)) { | |
2222 | update_shares(sd); | |
2223 | break; | |
2224 | } | |
2225 | } | |
2226 | } | |
2227 | #endif | |
2228 | ||
04e2f174 | 2229 | smp_wmb(); |
1da177e4 LT |
2230 | rq = task_rq_lock(p, &flags); |
2231 | old_state = p->state; | |
2232 | if (!(old_state & state)) | |
2233 | goto out; | |
2234 | ||
dd41f596 | 2235 | if (p->se.on_rq) |
1da177e4 LT |
2236 | goto out_running; |
2237 | ||
2238 | cpu = task_cpu(p); | |
cc367732 | 2239 | orig_cpu = cpu; |
1da177e4 LT |
2240 | this_cpu = smp_processor_id(); |
2241 | ||
2242 | #ifdef CONFIG_SMP | |
2243 | if (unlikely(task_running(rq, p))) | |
2244 | goto out_activate; | |
2245 | ||
5d2f5a61 DA |
2246 | cpu = p->sched_class->select_task_rq(p, sync); |
2247 | if (cpu != orig_cpu) { | |
2248 | set_task_cpu(p, cpu); | |
1da177e4 LT |
2249 | task_rq_unlock(rq, &flags); |
2250 | /* might preempt at this point */ | |
2251 | rq = task_rq_lock(p, &flags); | |
2252 | old_state = p->state; | |
2253 | if (!(old_state & state)) | |
2254 | goto out; | |
dd41f596 | 2255 | if (p->se.on_rq) |
1da177e4 LT |
2256 | goto out_running; |
2257 | ||
2258 | this_cpu = smp_processor_id(); | |
2259 | cpu = task_cpu(p); | |
2260 | } | |
2261 | ||
e7693a36 GH |
2262 | #ifdef CONFIG_SCHEDSTATS |
2263 | schedstat_inc(rq, ttwu_count); | |
2264 | if (cpu == this_cpu) | |
2265 | schedstat_inc(rq, ttwu_local); | |
2266 | else { | |
2267 | struct sched_domain *sd; | |
2268 | for_each_domain(this_cpu, sd) { | |
2269 | if (cpu_isset(cpu, sd->span)) { | |
2270 | schedstat_inc(sd, ttwu_wake_remote); | |
2271 | break; | |
2272 | } | |
2273 | } | |
2274 | } | |
6d6bc0ad | 2275 | #endif /* CONFIG_SCHEDSTATS */ |
e7693a36 | 2276 | |
1da177e4 LT |
2277 | out_activate: |
2278 | #endif /* CONFIG_SMP */ | |
cc367732 IM |
2279 | schedstat_inc(p, se.nr_wakeups); |
2280 | if (sync) | |
2281 | schedstat_inc(p, se.nr_wakeups_sync); | |
2282 | if (orig_cpu != cpu) | |
2283 | schedstat_inc(p, se.nr_wakeups_migrate); | |
2284 | if (cpu == this_cpu) | |
2285 | schedstat_inc(p, se.nr_wakeups_local); | |
2286 | else | |
2287 | schedstat_inc(p, se.nr_wakeups_remote); | |
2daa3577 | 2288 | update_rq_clock(rq); |
dd41f596 | 2289 | activate_task(rq, p, 1); |
1da177e4 LT |
2290 | success = 1; |
2291 | ||
2292 | out_running: | |
0a16b607 | 2293 | trace_sched_wakeup(rq, p); |
15afe09b | 2294 | check_preempt_curr(rq, p, sync); |
4ae7d5ce | 2295 | |
1da177e4 | 2296 | p->state = TASK_RUNNING; |
9a897c5a SR |
2297 | #ifdef CONFIG_SMP |
2298 | if (p->sched_class->task_wake_up) | |
2299 | p->sched_class->task_wake_up(rq, p); | |
2300 | #endif | |
1da177e4 | 2301 | out: |
2087a1ad GH |
2302 | current->se.last_wakeup = current->se.sum_exec_runtime; |
2303 | ||
1da177e4 LT |
2304 | task_rq_unlock(rq, &flags); |
2305 | ||
2306 | return success; | |
2307 | } | |
2308 | ||
7ad5b3a5 | 2309 | int wake_up_process(struct task_struct *p) |
1da177e4 | 2310 | { |
d9514f6c | 2311 | return try_to_wake_up(p, TASK_ALL, 0); |
1da177e4 | 2312 | } |
1da177e4 LT |
2313 | EXPORT_SYMBOL(wake_up_process); |
2314 | ||
7ad5b3a5 | 2315 | int wake_up_state(struct task_struct *p, unsigned int state) |
1da177e4 LT |
2316 | { |
2317 | return try_to_wake_up(p, state, 0); | |
2318 | } | |
2319 | ||
1da177e4 LT |
2320 | /* |
2321 | * Perform scheduler related setup for a newly forked process p. | |
2322 | * p is forked by current. | |
dd41f596 IM |
2323 | * |
2324 | * __sched_fork() is basic setup used by init_idle() too: | |
2325 | */ | |
2326 | static void __sched_fork(struct task_struct *p) | |
2327 | { | |
dd41f596 IM |
2328 | p->se.exec_start = 0; |
2329 | p->se.sum_exec_runtime = 0; | |
f6cf891c | 2330 | p->se.prev_sum_exec_runtime = 0; |
4ae7d5ce IM |
2331 | p->se.last_wakeup = 0; |
2332 | p->se.avg_overlap = 0; | |
6cfb0d5d IM |
2333 | |
2334 | #ifdef CONFIG_SCHEDSTATS | |
2335 | p->se.wait_start = 0; | |
dd41f596 IM |
2336 | p->se.sum_sleep_runtime = 0; |
2337 | p->se.sleep_start = 0; | |
dd41f596 IM |
2338 | p->se.block_start = 0; |
2339 | p->se.sleep_max = 0; | |
2340 | p->se.block_max = 0; | |
2341 | p->se.exec_max = 0; | |
eba1ed4b | 2342 | p->se.slice_max = 0; |
dd41f596 | 2343 | p->se.wait_max = 0; |
6cfb0d5d | 2344 | #endif |
476d139c | 2345 | |
fa717060 | 2346 | INIT_LIST_HEAD(&p->rt.run_list); |
dd41f596 | 2347 | p->se.on_rq = 0; |
4a55bd5e | 2348 | INIT_LIST_HEAD(&p->se.group_node); |
476d139c | 2349 | |
e107be36 AK |
2350 | #ifdef CONFIG_PREEMPT_NOTIFIERS |
2351 | INIT_HLIST_HEAD(&p->preempt_notifiers); | |
2352 | #endif | |
2353 | ||
1da177e4 LT |
2354 | /* |
2355 | * We mark the process as running here, but have not actually | |
2356 | * inserted it onto the runqueue yet. This guarantees that | |
2357 | * nobody will actually run it, and a signal or other external | |
2358 | * event cannot wake it up and insert it on the runqueue either. | |
2359 | */ | |
2360 | p->state = TASK_RUNNING; | |
dd41f596 IM |
2361 | } |
2362 | ||
2363 | /* | |
2364 | * fork()/clone()-time setup: | |
2365 | */ | |
2366 | void sched_fork(struct task_struct *p, int clone_flags) | |
2367 | { | |
2368 | int cpu = get_cpu(); | |
2369 | ||
2370 | __sched_fork(p); | |
2371 | ||
2372 | #ifdef CONFIG_SMP | |
2373 | cpu = sched_balance_self(cpu, SD_BALANCE_FORK); | |
2374 | #endif | |
02e4bac2 | 2375 | set_task_cpu(p, cpu); |
b29739f9 IM |
2376 | |
2377 | /* | |
2378 | * Make sure we do not leak PI boosting priority to the child: | |
2379 | */ | |
2380 | p->prio = current->normal_prio; | |
2ddbf952 HS |
2381 | if (!rt_prio(p->prio)) |
2382 | p->sched_class = &fair_sched_class; | |
b29739f9 | 2383 | |
52f17b6c | 2384 | #if defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT) |
dd41f596 | 2385 | if (likely(sched_info_on())) |
52f17b6c | 2386 | memset(&p->sched_info, 0, sizeof(p->sched_info)); |
1da177e4 | 2387 | #endif |
d6077cb8 | 2388 | #if defined(CONFIG_SMP) && defined(__ARCH_WANT_UNLOCKED_CTXSW) |
4866cde0 NP |
2389 | p->oncpu = 0; |
2390 | #endif | |
1da177e4 | 2391 | #ifdef CONFIG_PREEMPT |
4866cde0 | 2392 | /* Want to start with kernel preemption disabled. */ |
a1261f54 | 2393 | task_thread_info(p)->preempt_count = 1; |
1da177e4 | 2394 | #endif |
476d139c | 2395 | put_cpu(); |
1da177e4 LT |
2396 | } |
2397 | ||
2398 | /* | |
2399 | * wake_up_new_task - wake up a newly created task for the first time. | |
2400 | * | |
2401 | * This function will do some initial scheduler statistics housekeeping | |
2402 | * that must be done for every newly created context, then puts the task | |
2403 | * on the runqueue and wakes it. | |
2404 | */ | |
7ad5b3a5 | 2405 | void wake_up_new_task(struct task_struct *p, unsigned long clone_flags) |
1da177e4 LT |
2406 | { |
2407 | unsigned long flags; | |
dd41f596 | 2408 | struct rq *rq; |
1da177e4 LT |
2409 | |
2410 | rq = task_rq_lock(p, &flags); | |
147cbb4b | 2411 | BUG_ON(p->state != TASK_RUNNING); |
a8e504d2 | 2412 | update_rq_clock(rq); |
1da177e4 LT |
2413 | |
2414 | p->prio = effective_prio(p); | |
2415 | ||
b9dca1e0 | 2416 | if (!p->sched_class->task_new || !current->se.on_rq) { |
dd41f596 | 2417 | activate_task(rq, p, 0); |
1da177e4 | 2418 | } else { |
1da177e4 | 2419 | /* |
dd41f596 IM |
2420 | * Let the scheduling class do new task startup |
2421 | * management (if any): | |
1da177e4 | 2422 | */ |
ee0827d8 | 2423 | p->sched_class->task_new(rq, p); |
c09595f6 | 2424 | inc_nr_running(rq); |
1da177e4 | 2425 | } |
0a16b607 | 2426 | trace_sched_wakeup_new(rq, p); |
15afe09b | 2427 | check_preempt_curr(rq, p, 0); |
9a897c5a SR |
2428 | #ifdef CONFIG_SMP |
2429 | if (p->sched_class->task_wake_up) | |
2430 | p->sched_class->task_wake_up(rq, p); | |
2431 | #endif | |
dd41f596 | 2432 | task_rq_unlock(rq, &flags); |
1da177e4 LT |
2433 | } |
2434 | ||
e107be36 AK |
2435 | #ifdef CONFIG_PREEMPT_NOTIFIERS |
2436 | ||
2437 | /** | |
421cee29 RD |
2438 | * preempt_notifier_register - tell me when current is being being preempted & rescheduled |
2439 | * @notifier: notifier struct to register | |
e107be36 AK |
2440 | */ |
2441 | void preempt_notifier_register(struct preempt_notifier *notifier) | |
2442 | { | |
2443 | hlist_add_head(¬ifier->link, ¤t->preempt_notifiers); | |
2444 | } | |
2445 | EXPORT_SYMBOL_GPL(preempt_notifier_register); | |
2446 | ||
2447 | /** | |
2448 | * preempt_notifier_unregister - no longer interested in preemption notifications | |
421cee29 | 2449 | * @notifier: notifier struct to unregister |
e107be36 AK |
2450 | * |
2451 | * This is safe to call from within a preemption notifier. | |
2452 | */ | |
2453 | void preempt_notifier_unregister(struct preempt_notifier *notifier) | |
2454 | { | |
2455 | hlist_del(¬ifier->link); | |
2456 | } | |
2457 | EXPORT_SYMBOL_GPL(preempt_notifier_unregister); | |
2458 | ||
2459 | static void fire_sched_in_preempt_notifiers(struct task_struct *curr) | |
2460 | { | |
2461 | struct preempt_notifier *notifier; | |
2462 | struct hlist_node *node; | |
2463 | ||
2464 | hlist_for_each_entry(notifier, node, &curr->preempt_notifiers, link) | |
2465 | notifier->ops->sched_in(notifier, raw_smp_processor_id()); | |
2466 | } | |
2467 | ||
2468 | static void | |
2469 | fire_sched_out_preempt_notifiers(struct task_struct *curr, | |
2470 | struct task_struct *next) | |
2471 | { | |
2472 | struct preempt_notifier *notifier; | |
2473 | struct hlist_node *node; | |
2474 | ||
2475 | hlist_for_each_entry(notifier, node, &curr->preempt_notifiers, link) | |
2476 | notifier->ops->sched_out(notifier, next); | |
2477 | } | |
2478 | ||
6d6bc0ad | 2479 | #else /* !CONFIG_PREEMPT_NOTIFIERS */ |
e107be36 AK |
2480 | |
2481 | static void fire_sched_in_preempt_notifiers(struct task_struct *curr) | |
2482 | { | |
2483 | } | |
2484 | ||
2485 | static void | |
2486 | fire_sched_out_preempt_notifiers(struct task_struct *curr, | |
2487 | struct task_struct *next) | |
2488 | { | |
2489 | } | |
2490 | ||
6d6bc0ad | 2491 | #endif /* CONFIG_PREEMPT_NOTIFIERS */ |
e107be36 | 2492 | |
4866cde0 NP |
2493 | /** |
2494 | * prepare_task_switch - prepare to switch tasks | |
2495 | * @rq: the runqueue preparing to switch | |
421cee29 | 2496 | * @prev: the current task that is being switched out |
4866cde0 NP |
2497 | * @next: the task we are going to switch to. |
2498 | * | |
2499 | * This is called with the rq lock held and interrupts off. It must | |
2500 | * be paired with a subsequent finish_task_switch after the context | |
2501 | * switch. | |
2502 | * | |
2503 | * prepare_task_switch sets up locking and calls architecture specific | |
2504 | * hooks. | |
2505 | */ | |
e107be36 AK |
2506 | static inline void |
2507 | prepare_task_switch(struct rq *rq, struct task_struct *prev, | |
2508 | struct task_struct *next) | |
4866cde0 | 2509 | { |
e107be36 | 2510 | fire_sched_out_preempt_notifiers(prev, next); |
4866cde0 NP |
2511 | prepare_lock_switch(rq, next); |
2512 | prepare_arch_switch(next); | |
2513 | } | |
2514 | ||
1da177e4 LT |
2515 | /** |
2516 | * finish_task_switch - clean up after a task-switch | |
344babaa | 2517 | * @rq: runqueue associated with task-switch |
1da177e4 LT |
2518 | * @prev: the thread we just switched away from. |
2519 | * | |
4866cde0 NP |
2520 | * finish_task_switch must be called after the context switch, paired |
2521 | * with a prepare_task_switch call before the context switch. | |
2522 | * finish_task_switch will reconcile locking set up by prepare_task_switch, | |
2523 | * and do any other architecture-specific cleanup actions. | |
1da177e4 LT |
2524 | * |
2525 | * Note that we may have delayed dropping an mm in context_switch(). If | |
41a2d6cf | 2526 | * so, we finish that here outside of the runqueue lock. (Doing it |
1da177e4 LT |
2527 | * with the lock held can cause deadlocks; see schedule() for |
2528 | * details.) | |
2529 | */ | |
a9957449 | 2530 | static void finish_task_switch(struct rq *rq, struct task_struct *prev) |
1da177e4 LT |
2531 | __releases(rq->lock) |
2532 | { | |
1da177e4 | 2533 | struct mm_struct *mm = rq->prev_mm; |
55a101f8 | 2534 | long prev_state; |
1da177e4 LT |
2535 | |
2536 | rq->prev_mm = NULL; | |
2537 | ||
2538 | /* | |
2539 | * A task struct has one reference for the use as "current". | |
c394cc9f | 2540 | * If a task dies, then it sets TASK_DEAD in tsk->state and calls |
55a101f8 ON |
2541 | * schedule one last time. The schedule call will never return, and |
2542 | * the scheduled task must drop that reference. | |
c394cc9f | 2543 | * The test for TASK_DEAD must occur while the runqueue locks are |
1da177e4 LT |
2544 | * still held, otherwise prev could be scheduled on another cpu, die |
2545 | * there before we look at prev->state, and then the reference would | |
2546 | * be dropped twice. | |
2547 | * Manfred Spraul <manfred@colorfullife.com> | |
2548 | */ | |
55a101f8 | 2549 | prev_state = prev->state; |
4866cde0 NP |
2550 | finish_arch_switch(prev); |
2551 | finish_lock_switch(rq, prev); | |
9a897c5a SR |
2552 | #ifdef CONFIG_SMP |
2553 | if (current->sched_class->post_schedule) | |
2554 | current->sched_class->post_schedule(rq); | |
2555 | #endif | |
e8fa1362 | 2556 | |
e107be36 | 2557 | fire_sched_in_preempt_notifiers(current); |
1da177e4 LT |
2558 | if (mm) |
2559 | mmdrop(mm); | |
c394cc9f | 2560 | if (unlikely(prev_state == TASK_DEAD)) { |
c6fd91f0 | 2561 | /* |
2562 | * Remove function-return probe instances associated with this | |
2563 | * task and put them back on the free list. | |
9761eea8 | 2564 | */ |
c6fd91f0 | 2565 | kprobe_flush_task(prev); |
1da177e4 | 2566 | put_task_struct(prev); |
c6fd91f0 | 2567 | } |
1da177e4 LT |
2568 | } |
2569 | ||
2570 | /** | |
2571 | * schedule_tail - first thing a freshly forked thread must call. | |
2572 | * @prev: the thread we just switched away from. | |
2573 | */ | |
36c8b586 | 2574 | asmlinkage void schedule_tail(struct task_struct *prev) |
1da177e4 LT |
2575 | __releases(rq->lock) |
2576 | { | |
70b97a7f IM |
2577 | struct rq *rq = this_rq(); |
2578 | ||
4866cde0 NP |
2579 | finish_task_switch(rq, prev); |
2580 | #ifdef __ARCH_WANT_UNLOCKED_CTXSW | |
2581 | /* In this case, finish_task_switch does not reenable preemption */ | |
2582 | preempt_enable(); | |
2583 | #endif | |
1da177e4 | 2584 | if (current->set_child_tid) |
b488893a | 2585 | put_user(task_pid_vnr(current), current->set_child_tid); |
1da177e4 LT |
2586 | } |
2587 | ||
2588 | /* | |
2589 | * context_switch - switch to the new MM and the new | |
2590 | * thread's register state. | |
2591 | */ | |
dd41f596 | 2592 | static inline void |
70b97a7f | 2593 | context_switch(struct rq *rq, struct task_struct *prev, |
36c8b586 | 2594 | struct task_struct *next) |
1da177e4 | 2595 | { |
dd41f596 | 2596 | struct mm_struct *mm, *oldmm; |
1da177e4 | 2597 | |
e107be36 | 2598 | prepare_task_switch(rq, prev, next); |
0a16b607 | 2599 | trace_sched_switch(rq, prev, next); |
dd41f596 IM |
2600 | mm = next->mm; |
2601 | oldmm = prev->active_mm; | |
9226d125 ZA |
2602 | /* |
2603 | * For paravirt, this is coupled with an exit in switch_to to | |
2604 | * combine the page table reload and the switch backend into | |
2605 | * one hypercall. | |
2606 | */ | |
2607 | arch_enter_lazy_cpu_mode(); | |
2608 | ||
dd41f596 | 2609 | if (unlikely(!mm)) { |
1da177e4 LT |
2610 | next->active_mm = oldmm; |
2611 | atomic_inc(&oldmm->mm_count); | |
2612 | enter_lazy_tlb(oldmm, next); | |
2613 | } else | |
2614 | switch_mm(oldmm, mm, next); | |
2615 | ||
dd41f596 | 2616 | if (unlikely(!prev->mm)) { |
1da177e4 | 2617 | prev->active_mm = NULL; |
1da177e4 LT |
2618 | rq->prev_mm = oldmm; |
2619 | } | |
3a5f5e48 IM |
2620 | /* |
2621 | * Since the runqueue lock will be released by the next | |
2622 | * task (which is an invalid locking op but in the case | |
2623 | * of the scheduler it's an obvious special-case), so we | |
2624 | * do an early lockdep release here: | |
2625 | */ | |
2626 | #ifndef __ARCH_WANT_UNLOCKED_CTXSW | |
8a25d5de | 2627 | spin_release(&rq->lock.dep_map, 1, _THIS_IP_); |
3a5f5e48 | 2628 | #endif |
1da177e4 LT |
2629 | |
2630 | /* Here we just switch the register state and the stack. */ | |
2631 | switch_to(prev, next, prev); | |
2632 | ||
dd41f596 IM |
2633 | barrier(); |
2634 | /* | |
2635 | * this_rq must be evaluated again because prev may have moved | |
2636 | * CPUs since it called schedule(), thus the 'rq' on its stack | |
2637 | * frame will be invalid. | |
2638 | */ | |
2639 | finish_task_switch(this_rq(), prev); | |
1da177e4 LT |
2640 | } |
2641 | ||
2642 | /* | |
2643 | * nr_running, nr_uninterruptible and nr_context_switches: | |
2644 | * | |
2645 | * externally visible scheduler statistics: current number of runnable | |
2646 | * threads, current number of uninterruptible-sleeping threads, total | |
2647 | * number of context switches performed since bootup. | |
2648 | */ | |
2649 | unsigned long nr_running(void) | |
2650 | { | |
2651 | unsigned long i, sum = 0; | |
2652 | ||
2653 | for_each_online_cpu(i) | |
2654 | sum += cpu_rq(i)->nr_running; | |
2655 | ||
2656 | return sum; | |
2657 | } | |
2658 | ||
2659 | unsigned long nr_uninterruptible(void) | |
2660 | { | |
2661 | unsigned long i, sum = 0; | |
2662 | ||
0a945022 | 2663 | for_each_possible_cpu(i) |
1da177e4 LT |
2664 | sum += cpu_rq(i)->nr_uninterruptible; |
2665 | ||
2666 | /* | |
2667 | * Since we read the counters lockless, it might be slightly | |
2668 | * inaccurate. Do not allow it to go below zero though: | |
2669 | */ | |
2670 | if (unlikely((long)sum < 0)) | |
2671 | sum = 0; | |
2672 | ||
2673 | return sum; | |
2674 | } | |
2675 | ||
2676 | unsigned long long nr_context_switches(void) | |
2677 | { | |
cc94abfc SR |
2678 | int i; |
2679 | unsigned long long sum = 0; | |
1da177e4 | 2680 | |
0a945022 | 2681 | for_each_possible_cpu(i) |
1da177e4 LT |
2682 | sum += cpu_rq(i)->nr_switches; |
2683 | ||
2684 | return sum; | |
2685 | } | |
2686 | ||
2687 | unsigned long nr_iowait(void) | |
2688 | { | |
2689 | unsigned long i, sum = 0; | |
2690 | ||
0a945022 | 2691 | for_each_possible_cpu(i) |
1da177e4 LT |
2692 | sum += atomic_read(&cpu_rq(i)->nr_iowait); |
2693 | ||
2694 | return sum; | |
2695 | } | |
2696 | ||
db1b1fef JS |
2697 | unsigned long nr_active(void) |
2698 | { | |
2699 | unsigned long i, running = 0, uninterruptible = 0; | |
2700 | ||
2701 | for_each_online_cpu(i) { | |
2702 | running += cpu_rq(i)->nr_running; | |
2703 | uninterruptible += cpu_rq(i)->nr_uninterruptible; | |
2704 | } | |
2705 | ||
2706 | if (unlikely((long)uninterruptible < 0)) | |
2707 | uninterruptible = 0; | |
2708 | ||
2709 | return running + uninterruptible; | |
2710 | } | |
2711 | ||
48f24c4d | 2712 | /* |
dd41f596 IM |
2713 | * Update rq->cpu_load[] statistics. This function is usually called every |
2714 | * scheduler tick (TICK_NSEC). | |
48f24c4d | 2715 | */ |
dd41f596 | 2716 | static void update_cpu_load(struct rq *this_rq) |
48f24c4d | 2717 | { |
495eca49 | 2718 | unsigned long this_load = this_rq->load.weight; |
dd41f596 IM |
2719 | int i, scale; |
2720 | ||
2721 | this_rq->nr_load_updates++; | |
dd41f596 IM |
2722 | |
2723 | /* Update our load: */ | |
2724 | for (i = 0, scale = 1; i < CPU_LOAD_IDX_MAX; i++, scale += scale) { | |
2725 | unsigned long old_load, new_load; | |
2726 | ||
2727 | /* scale is effectively 1 << i now, and >> i divides by scale */ | |
2728 | ||
2729 | old_load = this_rq->cpu_load[i]; | |
2730 | new_load = this_load; | |
a25707f3 IM |
2731 | /* |
2732 | * Round up the averaging division if load is increasing. This | |
2733 | * prevents us from getting stuck on 9 if the load is 10, for | |
2734 | * example. | |
2735 | */ | |
2736 | if (new_load > old_load) | |
2737 | new_load += scale-1; | |
dd41f596 IM |
2738 | this_rq->cpu_load[i] = (old_load*(scale-1) + new_load) >> i; |
2739 | } | |
48f24c4d IM |
2740 | } |
2741 | ||
dd41f596 IM |
2742 | #ifdef CONFIG_SMP |
2743 | ||
1da177e4 LT |
2744 | /* |
2745 | * double_rq_lock - safely lock two runqueues | |
2746 | * | |
2747 | * Note this does not disable interrupts like task_rq_lock, | |
2748 | * you need to do so manually before calling. | |
2749 | */ | |
70b97a7f | 2750 | static void double_rq_lock(struct rq *rq1, struct rq *rq2) |
1da177e4 LT |
2751 | __acquires(rq1->lock) |
2752 | __acquires(rq2->lock) | |
2753 | { | |
054b9108 | 2754 | BUG_ON(!irqs_disabled()); |
1da177e4 LT |
2755 | if (rq1 == rq2) { |
2756 | spin_lock(&rq1->lock); | |
2757 | __acquire(rq2->lock); /* Fake it out ;) */ | |
2758 | } else { | |
c96d145e | 2759 | if (rq1 < rq2) { |
1da177e4 | 2760 | spin_lock(&rq1->lock); |
5e710e37 | 2761 | spin_lock_nested(&rq2->lock, SINGLE_DEPTH_NESTING); |
1da177e4 LT |
2762 | } else { |
2763 | spin_lock(&rq2->lock); | |
5e710e37 | 2764 | spin_lock_nested(&rq1->lock, SINGLE_DEPTH_NESTING); |
1da177e4 LT |
2765 | } |
2766 | } | |
6e82a3be IM |
2767 | update_rq_clock(rq1); |
2768 | update_rq_clock(rq2); | |
1da177e4 LT |
2769 | } |
2770 | ||
2771 | /* | |
2772 | * double_rq_unlock - safely unlock two runqueues | |
2773 | * | |
2774 | * Note this does not restore interrupts like task_rq_unlock, | |
2775 | * you need to do so manually after calling. | |
2776 | */ | |
70b97a7f | 2777 | static void double_rq_unlock(struct rq *rq1, struct rq *rq2) |
1da177e4 LT |
2778 | __releases(rq1->lock) |
2779 | __releases(rq2->lock) | |
2780 | { | |
2781 | spin_unlock(&rq1->lock); | |
2782 | if (rq1 != rq2) | |
2783 | spin_unlock(&rq2->lock); | |
2784 | else | |
2785 | __release(rq2->lock); | |
2786 | } | |
2787 | ||
2788 | /* | |
2789 | * double_lock_balance - lock the busiest runqueue, this_rq is locked already. | |
2790 | */ | |
e8fa1362 | 2791 | static int double_lock_balance(struct rq *this_rq, struct rq *busiest) |
1da177e4 LT |
2792 | __releases(this_rq->lock) |
2793 | __acquires(busiest->lock) | |
2794 | __acquires(this_rq->lock) | |
2795 | { | |
e8fa1362 SR |
2796 | int ret = 0; |
2797 | ||
054b9108 KK |
2798 | if (unlikely(!irqs_disabled())) { |
2799 | /* printk() doesn't work good under rq->lock */ | |
2800 | spin_unlock(&this_rq->lock); | |
2801 | BUG_ON(1); | |
2802 | } | |
1da177e4 | 2803 | if (unlikely(!spin_trylock(&busiest->lock))) { |
c96d145e | 2804 | if (busiest < this_rq) { |
1da177e4 LT |
2805 | spin_unlock(&this_rq->lock); |
2806 | spin_lock(&busiest->lock); | |
5e710e37 | 2807 | spin_lock_nested(&this_rq->lock, SINGLE_DEPTH_NESTING); |
e8fa1362 | 2808 | ret = 1; |
1da177e4 | 2809 | } else |
5e710e37 | 2810 | spin_lock_nested(&busiest->lock, SINGLE_DEPTH_NESTING); |
1da177e4 | 2811 | } |
e8fa1362 | 2812 | return ret; |
1da177e4 LT |
2813 | } |
2814 | ||
cf7f8690 | 2815 | static inline void double_unlock_balance(struct rq *this_rq, struct rq *busiest) |
1b12bbc7 PZ |
2816 | __releases(busiest->lock) |
2817 | { | |
2818 | spin_unlock(&busiest->lock); | |
2819 | lock_set_subclass(&this_rq->lock.dep_map, 0, _RET_IP_); | |
2820 | } | |
2821 | ||
1da177e4 LT |
2822 | /* |
2823 | * If dest_cpu is allowed for this process, migrate the task to it. | |
2824 | * This is accomplished by forcing the cpu_allowed mask to only | |
41a2d6cf | 2825 | * allow dest_cpu, which will force the cpu onto dest_cpu. Then |
1da177e4 LT |
2826 | * the cpu_allowed mask is restored. |
2827 | */ | |
36c8b586 | 2828 | static void sched_migrate_task(struct task_struct *p, int dest_cpu) |
1da177e4 | 2829 | { |
70b97a7f | 2830 | struct migration_req req; |
1da177e4 | 2831 | unsigned long flags; |
70b97a7f | 2832 | struct rq *rq; |
1da177e4 LT |
2833 | |
2834 | rq = task_rq_lock(p, &flags); | |
2835 | if (!cpu_isset(dest_cpu, p->cpus_allowed) | |
e761b772 | 2836 | || unlikely(!cpu_active(dest_cpu))) |
1da177e4 LT |
2837 | goto out; |
2838 | ||
0a16b607 | 2839 | trace_sched_migrate_task(rq, p, dest_cpu); |
1da177e4 LT |
2840 | /* force the process onto the specified CPU */ |
2841 | if (migrate_task(p, dest_cpu, &req)) { | |
2842 | /* Need to wait for migration thread (might exit: take ref). */ | |
2843 | struct task_struct *mt = rq->migration_thread; | |
36c8b586 | 2844 | |
1da177e4 LT |
2845 | get_task_struct(mt); |
2846 | task_rq_unlock(rq, &flags); | |
2847 | wake_up_process(mt); | |
2848 | put_task_struct(mt); | |
2849 | wait_for_completion(&req.done); | |
36c8b586 | 2850 | |
1da177e4 LT |
2851 | return; |
2852 | } | |
2853 | out: | |
2854 | task_rq_unlock(rq, &flags); | |
2855 | } | |
2856 | ||
2857 | /* | |
476d139c NP |
2858 | * sched_exec - execve() is a valuable balancing opportunity, because at |
2859 | * this point the task has the smallest effective memory and cache footprint. | |
1da177e4 LT |
2860 | */ |
2861 | void sched_exec(void) | |
2862 | { | |
1da177e4 | 2863 | int new_cpu, this_cpu = get_cpu(); |
476d139c | 2864 | new_cpu = sched_balance_self(this_cpu, SD_BALANCE_EXEC); |
1da177e4 | 2865 | put_cpu(); |
476d139c NP |
2866 | if (new_cpu != this_cpu) |
2867 | sched_migrate_task(current, new_cpu); | |
1da177e4 LT |
2868 | } |
2869 | ||
2870 | /* | |
2871 | * pull_task - move a task from a remote runqueue to the local runqueue. | |
2872 | * Both runqueues must be locked. | |
2873 | */ | |
dd41f596 IM |
2874 | static void pull_task(struct rq *src_rq, struct task_struct *p, |
2875 | struct rq *this_rq, int this_cpu) | |
1da177e4 | 2876 | { |
2e1cb74a | 2877 | deactivate_task(src_rq, p, 0); |
1da177e4 | 2878 | set_task_cpu(p, this_cpu); |
dd41f596 | 2879 | activate_task(this_rq, p, 0); |
1da177e4 LT |
2880 | /* |
2881 | * Note that idle threads have a prio of MAX_PRIO, for this test | |
2882 | * to be always true for them. | |
2883 | */ | |
15afe09b | 2884 | check_preempt_curr(this_rq, p, 0); |
1da177e4 LT |
2885 | } |
2886 | ||
2887 | /* | |
2888 | * can_migrate_task - may task p from runqueue rq be migrated to this_cpu? | |
2889 | */ | |
858119e1 | 2890 | static |
70b97a7f | 2891 | int can_migrate_task(struct task_struct *p, struct rq *rq, int this_cpu, |
d15bcfdb | 2892 | struct sched_domain *sd, enum cpu_idle_type idle, |
95cdf3b7 | 2893 | int *all_pinned) |
1da177e4 LT |
2894 | { |
2895 | /* | |
2896 | * We do not migrate tasks that are: | |
2897 | * 1) running (obviously), or | |
2898 | * 2) cannot be migrated to this CPU due to cpus_allowed, or | |
2899 | * 3) are cache-hot on their current CPU. | |
2900 | */ | |
cc367732 IM |
2901 | if (!cpu_isset(this_cpu, p->cpus_allowed)) { |
2902 | schedstat_inc(p, se.nr_failed_migrations_affine); | |
1da177e4 | 2903 | return 0; |
cc367732 | 2904 | } |
81026794 NP |
2905 | *all_pinned = 0; |
2906 | ||
cc367732 IM |
2907 | if (task_running(rq, p)) { |
2908 | schedstat_inc(p, se.nr_failed_migrations_running); | |
81026794 | 2909 | return 0; |
cc367732 | 2910 | } |
1da177e4 | 2911 | |
da84d961 IM |
2912 | /* |
2913 | * Aggressive migration if: | |
2914 | * 1) task is cache cold, or | |
2915 | * 2) too many balance attempts have failed. | |
2916 | */ | |
2917 | ||
6bc1665b IM |
2918 | if (!task_hot(p, rq->clock, sd) || |
2919 | sd->nr_balance_failed > sd->cache_nice_tries) { | |
da84d961 | 2920 | #ifdef CONFIG_SCHEDSTATS |
cc367732 | 2921 | if (task_hot(p, rq->clock, sd)) { |
da84d961 | 2922 | schedstat_inc(sd, lb_hot_gained[idle]); |
cc367732 IM |
2923 | schedstat_inc(p, se.nr_forced_migrations); |
2924 | } | |
da84d961 IM |
2925 | #endif |
2926 | return 1; | |
2927 | } | |
2928 | ||
cc367732 IM |
2929 | if (task_hot(p, rq->clock, sd)) { |
2930 | schedstat_inc(p, se.nr_failed_migrations_hot); | |
da84d961 | 2931 | return 0; |
cc367732 | 2932 | } |
1da177e4 LT |
2933 | return 1; |
2934 | } | |
2935 | ||
e1d1484f PW |
2936 | static unsigned long |
2937 | balance_tasks(struct rq *this_rq, int this_cpu, struct rq *busiest, | |
2938 | unsigned long max_load_move, struct sched_domain *sd, | |
2939 | enum cpu_idle_type idle, int *all_pinned, | |
2940 | int *this_best_prio, struct rq_iterator *iterator) | |
1da177e4 | 2941 | { |
051c6764 | 2942 | int loops = 0, pulled = 0, pinned = 0; |
dd41f596 IM |
2943 | struct task_struct *p; |
2944 | long rem_load_move = max_load_move; | |
1da177e4 | 2945 | |
e1d1484f | 2946 | if (max_load_move == 0) |
1da177e4 LT |
2947 | goto out; |
2948 | ||
81026794 NP |
2949 | pinned = 1; |
2950 | ||
1da177e4 | 2951 | /* |
dd41f596 | 2952 | * Start the load-balancing iterator: |
1da177e4 | 2953 | */ |
dd41f596 IM |
2954 | p = iterator->start(iterator->arg); |
2955 | next: | |
b82d9fdd | 2956 | if (!p || loops++ > sysctl_sched_nr_migrate) |
1da177e4 | 2957 | goto out; |
051c6764 PZ |
2958 | |
2959 | if ((p->se.load.weight >> 1) > rem_load_move || | |
dd41f596 | 2960 | !can_migrate_task(p, busiest, this_cpu, sd, idle, &pinned)) { |
dd41f596 IM |
2961 | p = iterator->next(iterator->arg); |
2962 | goto next; | |
1da177e4 LT |
2963 | } |
2964 | ||
dd41f596 | 2965 | pull_task(busiest, p, this_rq, this_cpu); |
1da177e4 | 2966 | pulled++; |
dd41f596 | 2967 | rem_load_move -= p->se.load.weight; |
1da177e4 | 2968 | |
2dd73a4f | 2969 | /* |
b82d9fdd | 2970 | * We only want to steal up to the prescribed amount of weighted load. |
2dd73a4f | 2971 | */ |
e1d1484f | 2972 | if (rem_load_move > 0) { |
a4ac01c3 PW |
2973 | if (p->prio < *this_best_prio) |
2974 | *this_best_prio = p->prio; | |
dd41f596 IM |
2975 | p = iterator->next(iterator->arg); |
2976 | goto next; | |
1da177e4 LT |
2977 | } |
2978 | out: | |
2979 | /* | |
e1d1484f | 2980 | * Right now, this is one of only two places pull_task() is called, |
1da177e4 LT |
2981 | * so we can safely collect pull_task() stats here rather than |
2982 | * inside pull_task(). | |
2983 | */ | |
2984 | schedstat_add(sd, lb_gained[idle], pulled); | |
81026794 NP |
2985 | |
2986 | if (all_pinned) | |
2987 | *all_pinned = pinned; | |
e1d1484f PW |
2988 | |
2989 | return max_load_move - rem_load_move; | |
1da177e4 LT |
2990 | } |
2991 | ||
dd41f596 | 2992 | /* |
43010659 PW |
2993 | * move_tasks tries to move up to max_load_move weighted load from busiest to |
2994 | * this_rq, as part of a balancing operation within domain "sd". | |
2995 | * Returns 1 if successful and 0 otherwise. | |
dd41f596 IM |
2996 | * |
2997 | * Called with both runqueues locked. | |
2998 | */ | |
2999 | static int move_tasks(struct rq *this_rq, int this_cpu, struct rq *busiest, | |
43010659 | 3000 | unsigned long max_load_move, |
dd41f596 IM |
3001 | struct sched_domain *sd, enum cpu_idle_type idle, |
3002 | int *all_pinned) | |
3003 | { | |
5522d5d5 | 3004 | const struct sched_class *class = sched_class_highest; |
43010659 | 3005 | unsigned long total_load_moved = 0; |
a4ac01c3 | 3006 | int this_best_prio = this_rq->curr->prio; |
dd41f596 IM |
3007 | |
3008 | do { | |
43010659 PW |
3009 | total_load_moved += |
3010 | class->load_balance(this_rq, this_cpu, busiest, | |
e1d1484f | 3011 | max_load_move - total_load_moved, |
a4ac01c3 | 3012 | sd, idle, all_pinned, &this_best_prio); |
dd41f596 | 3013 | class = class->next; |
c4acb2c0 GH |
3014 | |
3015 | if (idle == CPU_NEWLY_IDLE && this_rq->nr_running) | |
3016 | break; | |
3017 | ||
43010659 | 3018 | } while (class && max_load_move > total_load_moved); |
dd41f596 | 3019 | |
43010659 PW |
3020 | return total_load_moved > 0; |
3021 | } | |
3022 | ||
e1d1484f PW |
3023 | static int |
3024 | iter_move_one_task(struct rq *this_rq, int this_cpu, struct rq *busiest, | |
3025 | struct sched_domain *sd, enum cpu_idle_type idle, | |
3026 | struct rq_iterator *iterator) | |
3027 | { | |
3028 | struct task_struct *p = iterator->start(iterator->arg); | |
3029 | int pinned = 0; | |
3030 | ||
3031 | while (p) { | |
3032 | if (can_migrate_task(p, busiest, this_cpu, sd, idle, &pinned)) { | |
3033 | pull_task(busiest, p, this_rq, this_cpu); | |
3034 | /* | |
3035 | * Right now, this is only the second place pull_task() | |
3036 | * is called, so we can safely collect pull_task() | |
3037 | * stats here rather than inside pull_task(). | |
3038 | */ | |
3039 | schedstat_inc(sd, lb_gained[idle]); | |
3040 | ||
3041 | return 1; | |
3042 | } | |
3043 | p = iterator->next(iterator->arg); | |
3044 | } | |
3045 | ||
3046 | return 0; | |
3047 | } | |
3048 | ||
43010659 PW |
3049 | /* |
3050 | * move_one_task tries to move exactly one task from busiest to this_rq, as | |
3051 | * part of active balancing operations within "domain". | |
3052 | * Returns 1 if successful and 0 otherwise. | |
3053 | * | |
3054 | * Called with both runqueues locked. | |
3055 | */ | |
3056 | static int move_one_task(struct rq *this_rq, int this_cpu, struct rq *busiest, | |
3057 | struct sched_domain *sd, enum cpu_idle_type idle) | |
3058 | { | |
5522d5d5 | 3059 | const struct sched_class *class; |
43010659 PW |
3060 | |
3061 | for (class = sched_class_highest; class; class = class->next) | |
e1d1484f | 3062 | if (class->move_one_task(this_rq, this_cpu, busiest, sd, idle)) |
43010659 PW |
3063 | return 1; |
3064 | ||
3065 | return 0; | |
dd41f596 IM |
3066 | } |
3067 | ||
1da177e4 LT |
3068 | /* |
3069 | * find_busiest_group finds and returns the busiest CPU group within the | |
48f24c4d IM |
3070 | * domain. It calculates and returns the amount of weighted load which |
3071 | * should be moved to restore balance via the imbalance parameter. | |
1da177e4 LT |
3072 | */ |
3073 | static struct sched_group * | |
3074 | find_busiest_group(struct sched_domain *sd, int this_cpu, | |
dd41f596 | 3075 | unsigned long *imbalance, enum cpu_idle_type idle, |
7c16ec58 | 3076 | int *sd_idle, const cpumask_t *cpus, int *balance) |
1da177e4 LT |
3077 | { |
3078 | struct sched_group *busiest = NULL, *this = NULL, *group = sd->groups; | |
3079 | unsigned long max_load, avg_load, total_load, this_load, total_pwr; | |
0c117f1b | 3080 | unsigned long max_pull; |
2dd73a4f PW |
3081 | unsigned long busiest_load_per_task, busiest_nr_running; |
3082 | unsigned long this_load_per_task, this_nr_running; | |
908a7c1b | 3083 | int load_idx, group_imb = 0; |
5c45bf27 SS |
3084 | #if defined(CONFIG_SCHED_MC) || defined(CONFIG_SCHED_SMT) |
3085 | int power_savings_balance = 1; | |
3086 | unsigned long leader_nr_running = 0, min_load_per_task = 0; | |
3087 | unsigned long min_nr_running = ULONG_MAX; | |
3088 | struct sched_group *group_min = NULL, *group_leader = NULL; | |
3089 | #endif | |
1da177e4 LT |
3090 | |
3091 | max_load = this_load = total_load = total_pwr = 0; | |
2dd73a4f PW |
3092 | busiest_load_per_task = busiest_nr_running = 0; |
3093 | this_load_per_task = this_nr_running = 0; | |
408ed066 | 3094 | |
d15bcfdb | 3095 | if (idle == CPU_NOT_IDLE) |
7897986b | 3096 | load_idx = sd->busy_idx; |
d15bcfdb | 3097 | else if (idle == CPU_NEWLY_IDLE) |
7897986b NP |
3098 | load_idx = sd->newidle_idx; |
3099 | else | |
3100 | load_idx = sd->idle_idx; | |
1da177e4 LT |
3101 | |
3102 | do { | |
908a7c1b | 3103 | unsigned long load, group_capacity, max_cpu_load, min_cpu_load; |
1da177e4 LT |
3104 | int local_group; |
3105 | int i; | |
908a7c1b | 3106 | int __group_imb = 0; |
783609c6 | 3107 | unsigned int balance_cpu = -1, first_idle_cpu = 0; |
2dd73a4f | 3108 | unsigned long sum_nr_running, sum_weighted_load; |
408ed066 PZ |
3109 | unsigned long sum_avg_load_per_task; |
3110 | unsigned long avg_load_per_task; | |
1da177e4 LT |
3111 | |
3112 | local_group = cpu_isset(this_cpu, group->cpumask); | |
3113 | ||
783609c6 SS |
3114 | if (local_group) |
3115 | balance_cpu = first_cpu(group->cpumask); | |
3116 | ||
1da177e4 | 3117 | /* Tally up the load of all CPUs in the group */ |
2dd73a4f | 3118 | sum_weighted_load = sum_nr_running = avg_load = 0; |
408ed066 PZ |
3119 | sum_avg_load_per_task = avg_load_per_task = 0; |
3120 | ||
908a7c1b KC |
3121 | max_cpu_load = 0; |
3122 | min_cpu_load = ~0UL; | |
1da177e4 | 3123 | |
abcd083a | 3124 | for_each_cpu(i, &group->cpumask) { |
0a2966b4 CL |
3125 | struct rq *rq; |
3126 | ||
3127 | if (!cpu_isset(i, *cpus)) | |
3128 | continue; | |
3129 | ||
3130 | rq = cpu_rq(i); | |
2dd73a4f | 3131 | |
9439aab8 | 3132 | if (*sd_idle && rq->nr_running) |
5969fe06 NP |
3133 | *sd_idle = 0; |
3134 | ||
1da177e4 | 3135 | /* Bias balancing toward cpus of our domain */ |
783609c6 SS |
3136 | if (local_group) { |
3137 | if (idle_cpu(i) && !first_idle_cpu) { | |
3138 | first_idle_cpu = 1; | |
3139 | balance_cpu = i; | |
3140 | } | |
3141 | ||
a2000572 | 3142 | load = target_load(i, load_idx); |
908a7c1b | 3143 | } else { |
a2000572 | 3144 | load = source_load(i, load_idx); |
908a7c1b KC |
3145 | if (load > max_cpu_load) |
3146 | max_cpu_load = load; | |
3147 | if (min_cpu_load > load) | |
3148 | min_cpu_load = load; | |
3149 | } | |
1da177e4 LT |
3150 | |
3151 | avg_load += load; | |
2dd73a4f | 3152 | sum_nr_running += rq->nr_running; |
dd41f596 | 3153 | sum_weighted_load += weighted_cpuload(i); |
408ed066 PZ |
3154 | |
3155 | sum_avg_load_per_task += cpu_avg_load_per_task(i); | |
1da177e4 LT |
3156 | } |
3157 | ||
783609c6 SS |
3158 | /* |
3159 | * First idle cpu or the first cpu(busiest) in this sched group | |
3160 | * is eligible for doing load balancing at this and above | |
9439aab8 SS |
3161 | * domains. In the newly idle case, we will allow all the cpu's |
3162 | * to do the newly idle load balance. | |
783609c6 | 3163 | */ |
9439aab8 SS |
3164 | if (idle != CPU_NEWLY_IDLE && local_group && |
3165 | balance_cpu != this_cpu && balance) { | |
783609c6 SS |
3166 | *balance = 0; |
3167 | goto ret; | |
3168 | } | |
3169 | ||
1da177e4 | 3170 | total_load += avg_load; |
5517d86b | 3171 | total_pwr += group->__cpu_power; |
1da177e4 LT |
3172 | |
3173 | /* Adjust by relative CPU power of the group */ | |
5517d86b ED |
3174 | avg_load = sg_div_cpu_power(group, |
3175 | avg_load * SCHED_LOAD_SCALE); | |
1da177e4 | 3176 | |
408ed066 PZ |
3177 | |
3178 | /* | |
3179 | * Consider the group unbalanced when the imbalance is larger | |
3180 | * than the average weight of two tasks. | |
3181 | * | |
3182 | * APZ: with cgroup the avg task weight can vary wildly and | |
3183 | * might not be a suitable number - should we keep a | |
3184 | * normalized nr_running number somewhere that negates | |
3185 | * the hierarchy? | |
3186 | */ | |
3187 | avg_load_per_task = sg_div_cpu_power(group, | |
3188 | sum_avg_load_per_task * SCHED_LOAD_SCALE); | |
3189 | ||
3190 | if ((max_cpu_load - min_cpu_load) > 2*avg_load_per_task) | |
908a7c1b KC |
3191 | __group_imb = 1; |
3192 | ||
5517d86b | 3193 | group_capacity = group->__cpu_power / SCHED_LOAD_SCALE; |
5c45bf27 | 3194 | |
1da177e4 LT |
3195 | if (local_group) { |
3196 | this_load = avg_load; | |
3197 | this = group; | |
2dd73a4f PW |
3198 | this_nr_running = sum_nr_running; |
3199 | this_load_per_task = sum_weighted_load; | |
3200 | } else if (avg_load > max_load && | |
908a7c1b | 3201 | (sum_nr_running > group_capacity || __group_imb)) { |
1da177e4 LT |
3202 | max_load = avg_load; |
3203 | busiest = group; | |
2dd73a4f PW |
3204 | busiest_nr_running = sum_nr_running; |
3205 | busiest_load_per_task = sum_weighted_load; | |
908a7c1b | 3206 | group_imb = __group_imb; |
1da177e4 | 3207 | } |
5c45bf27 SS |
3208 | |
3209 | #if defined(CONFIG_SCHED_MC) || defined(CONFIG_SCHED_SMT) | |
3210 | /* | |
3211 | * Busy processors will not participate in power savings | |
3212 | * balance. | |
3213 | */ | |
dd41f596 IM |
3214 | if (idle == CPU_NOT_IDLE || |
3215 | !(sd->flags & SD_POWERSAVINGS_BALANCE)) | |
3216 | goto group_next; | |
5c45bf27 SS |
3217 | |
3218 | /* | |
3219 | * If the local group is idle or completely loaded | |
3220 | * no need to do power savings balance at this domain | |
3221 | */ | |
3222 | if (local_group && (this_nr_running >= group_capacity || | |
3223 | !this_nr_running)) | |
3224 | power_savings_balance = 0; | |
3225 | ||
dd41f596 | 3226 | /* |
5c45bf27 SS |
3227 | * If a group is already running at full capacity or idle, |
3228 | * don't include that group in power savings calculations | |
dd41f596 IM |
3229 | */ |
3230 | if (!power_savings_balance || sum_nr_running >= group_capacity | |
5c45bf27 | 3231 | || !sum_nr_running) |
dd41f596 | 3232 | goto group_next; |
5c45bf27 | 3233 | |
dd41f596 | 3234 | /* |
5c45bf27 | 3235 | * Calculate the group which has the least non-idle load. |
dd41f596 IM |
3236 | * This is the group from where we need to pick up the load |
3237 | * for saving power | |
3238 | */ | |
3239 | if ((sum_nr_running < min_nr_running) || | |
3240 | (sum_nr_running == min_nr_running && | |
5c45bf27 SS |
3241 | first_cpu(group->cpumask) < |
3242 | first_cpu(group_min->cpumask))) { | |
dd41f596 IM |
3243 | group_min = group; |
3244 | min_nr_running = sum_nr_running; | |
5c45bf27 SS |
3245 | min_load_per_task = sum_weighted_load / |
3246 | sum_nr_running; | |
dd41f596 | 3247 | } |
5c45bf27 | 3248 | |
dd41f596 | 3249 | /* |
5c45bf27 | 3250 | * Calculate the group which is almost near its |
dd41f596 IM |
3251 | * capacity but still has some space to pick up some load |
3252 | * from other group and save more power | |
3253 | */ | |
3254 | if (sum_nr_running <= group_capacity - 1) { | |
3255 | if (sum_nr_running > leader_nr_running || | |
3256 | (sum_nr_running == leader_nr_running && | |
3257 | first_cpu(group->cpumask) > | |
3258 | first_cpu(group_leader->cpumask))) { | |
3259 | group_leader = group; | |
3260 | leader_nr_running = sum_nr_running; | |
3261 | } | |
48f24c4d | 3262 | } |
5c45bf27 SS |
3263 | group_next: |
3264 | #endif | |
1da177e4 LT |
3265 | group = group->next; |
3266 | } while (group != sd->groups); | |
3267 | ||
2dd73a4f | 3268 | if (!busiest || this_load >= max_load || busiest_nr_running == 0) |
1da177e4 LT |
3269 | goto out_balanced; |
3270 | ||
3271 | avg_load = (SCHED_LOAD_SCALE * total_load) / total_pwr; | |
3272 | ||
3273 | if (this_load >= avg_load || | |
3274 | 100*max_load <= sd->imbalance_pct*this_load) | |
3275 | goto out_balanced; | |
3276 | ||
2dd73a4f | 3277 | busiest_load_per_task /= busiest_nr_running; |
908a7c1b KC |
3278 | if (group_imb) |
3279 | busiest_load_per_task = min(busiest_load_per_task, avg_load); | |
3280 | ||
1da177e4 LT |
3281 | /* |
3282 | * We're trying to get all the cpus to the average_load, so we don't | |
3283 | * want to push ourselves above the average load, nor do we wish to | |
3284 | * reduce the max loaded cpu below the average load, as either of these | |
3285 | * actions would just result in more rebalancing later, and ping-pong | |
3286 | * tasks around. Thus we look for the minimum possible imbalance. | |
3287 | * Negative imbalances (*we* are more loaded than anyone else) will | |
3288 | * be counted as no imbalance for these purposes -- we can't fix that | |
41a2d6cf | 3289 | * by pulling tasks to us. Be careful of negative numbers as they'll |
1da177e4 LT |
3290 | * appear as very large values with unsigned longs. |
3291 | */ | |
2dd73a4f PW |
3292 | if (max_load <= busiest_load_per_task) |
3293 | goto out_balanced; | |
3294 | ||
3295 | /* | |
3296 | * In the presence of smp nice balancing, certain scenarios can have | |
3297 | * max load less than avg load(as we skip the groups at or below | |
3298 | * its cpu_power, while calculating max_load..) | |
3299 | */ | |
3300 | if (max_load < avg_load) { | |
3301 | *imbalance = 0; | |
3302 | goto small_imbalance; | |
3303 | } | |
0c117f1b SS |
3304 | |
3305 | /* Don't want to pull so many tasks that a group would go idle */ | |
2dd73a4f | 3306 | max_pull = min(max_load - avg_load, max_load - busiest_load_per_task); |
0c117f1b | 3307 | |
1da177e4 | 3308 | /* How much load to actually move to equalise the imbalance */ |
5517d86b ED |
3309 | *imbalance = min(max_pull * busiest->__cpu_power, |
3310 | (avg_load - this_load) * this->__cpu_power) | |
1da177e4 LT |
3311 | / SCHED_LOAD_SCALE; |
3312 | ||
2dd73a4f PW |
3313 | /* |
3314 | * if *imbalance is less than the average load per runnable task | |
3315 | * there is no gaurantee that any tasks will be moved so we'll have | |
3316 | * a think about bumping its value to force at least one task to be | |
3317 | * moved | |
3318 | */ | |
7fd0d2dd | 3319 | if (*imbalance < busiest_load_per_task) { |
48f24c4d | 3320 | unsigned long tmp, pwr_now, pwr_move; |
2dd73a4f PW |
3321 | unsigned int imbn; |
3322 | ||
3323 | small_imbalance: | |
3324 | pwr_move = pwr_now = 0; | |
3325 | imbn = 2; | |
3326 | if (this_nr_running) { | |
3327 | this_load_per_task /= this_nr_running; | |
3328 | if (busiest_load_per_task > this_load_per_task) | |
3329 | imbn = 1; | |
3330 | } else | |
408ed066 | 3331 | this_load_per_task = cpu_avg_load_per_task(this_cpu); |
1da177e4 | 3332 | |
01c8c57d | 3333 | if (max_load - this_load + busiest_load_per_task >= |
dd41f596 | 3334 | busiest_load_per_task * imbn) { |
2dd73a4f | 3335 | *imbalance = busiest_load_per_task; |
1da177e4 LT |
3336 | return busiest; |
3337 | } | |
3338 | ||
3339 | /* | |
3340 | * OK, we don't have enough imbalance to justify moving tasks, | |
3341 | * however we may be able to increase total CPU power used by | |
3342 | * moving them. | |
3343 | */ | |
3344 | ||
5517d86b ED |
3345 | pwr_now += busiest->__cpu_power * |
3346 | min(busiest_load_per_task, max_load); | |
3347 | pwr_now += this->__cpu_power * | |
3348 | min(this_load_per_task, this_load); | |
1da177e4 LT |
3349 | pwr_now /= SCHED_LOAD_SCALE; |
3350 | ||
3351 | /* Amount of load we'd subtract */ | |
5517d86b ED |
3352 | tmp = sg_div_cpu_power(busiest, |
3353 | busiest_load_per_task * SCHED_LOAD_SCALE); | |
1da177e4 | 3354 | if (max_load > tmp) |
5517d86b | 3355 | pwr_move += busiest->__cpu_power * |
2dd73a4f | 3356 | min(busiest_load_per_task, max_load - tmp); |
1da177e4 LT |
3357 | |
3358 | /* Amount of load we'd add */ | |
5517d86b | 3359 | if (max_load * busiest->__cpu_power < |
33859f7f | 3360 | busiest_load_per_task * SCHED_LOAD_SCALE) |
5517d86b ED |
3361 | tmp = sg_div_cpu_power(this, |
3362 | max_load * busiest->__cpu_power); | |
1da177e4 | 3363 | else |
5517d86b ED |
3364 | tmp = sg_div_cpu_power(this, |
3365 | busiest_load_per_task * SCHED_LOAD_SCALE); | |
3366 | pwr_move += this->__cpu_power * | |
3367 | min(this_load_per_task, this_load + tmp); | |
1da177e4 LT |
3368 | pwr_move /= SCHED_LOAD_SCALE; |
3369 | ||
3370 | /* Move if we gain throughput */ | |
7fd0d2dd SS |
3371 | if (pwr_move > pwr_now) |
3372 | *imbalance = busiest_load_per_task; | |
1da177e4 LT |
3373 | } |
3374 | ||
1da177e4 LT |
3375 | return busiest; |
3376 | ||
3377 | out_balanced: | |
5c45bf27 | 3378 | #if defined(CONFIG_SCHED_MC) || defined(CONFIG_SCHED_SMT) |
d15bcfdb | 3379 | if (idle == CPU_NOT_IDLE || !(sd->flags & SD_POWERSAVINGS_BALANCE)) |
5c45bf27 | 3380 | goto ret; |
1da177e4 | 3381 | |
5c45bf27 SS |
3382 | if (this == group_leader && group_leader != group_min) { |
3383 | *imbalance = min_load_per_task; | |
3384 | return group_min; | |
3385 | } | |
5c45bf27 | 3386 | #endif |
783609c6 | 3387 | ret: |
1da177e4 LT |
3388 | *imbalance = 0; |
3389 | return NULL; | |
3390 | } | |
3391 | ||
3392 | /* | |
3393 | * find_busiest_queue - find the busiest runqueue among the cpus in group. | |
3394 | */ | |
70b97a7f | 3395 | static struct rq * |
d15bcfdb | 3396 | find_busiest_queue(struct sched_group *group, enum cpu_idle_type idle, |
7c16ec58 | 3397 | unsigned long imbalance, const cpumask_t *cpus) |
1da177e4 | 3398 | { |
70b97a7f | 3399 | struct rq *busiest = NULL, *rq; |
2dd73a4f | 3400 | unsigned long max_load = 0; |
1da177e4 LT |
3401 | int i; |
3402 | ||
abcd083a | 3403 | for_each_cpu(i, &group->cpumask) { |
dd41f596 | 3404 | unsigned long wl; |
0a2966b4 CL |
3405 | |
3406 | if (!cpu_isset(i, *cpus)) | |
3407 | continue; | |
3408 | ||
48f24c4d | 3409 | rq = cpu_rq(i); |
dd41f596 | 3410 | wl = weighted_cpuload(i); |
2dd73a4f | 3411 | |
dd41f596 | 3412 | if (rq->nr_running == 1 && wl > imbalance) |
2dd73a4f | 3413 | continue; |
1da177e4 | 3414 | |
dd41f596 IM |
3415 | if (wl > max_load) { |
3416 | max_load = wl; | |
48f24c4d | 3417 | busiest = rq; |
1da177e4 LT |
3418 | } |
3419 | } | |
3420 | ||
3421 | return busiest; | |
3422 | } | |
3423 | ||
77391d71 NP |
3424 | /* |
3425 | * Max backoff if we encounter pinned tasks. Pretty arbitrary value, but | |
3426 | * so long as it is large enough. | |
3427 | */ | |
3428 | #define MAX_PINNED_INTERVAL 512 | |
3429 | ||
1da177e4 LT |
3430 | /* |
3431 | * Check this_cpu to ensure it is balanced within domain. Attempt to move | |
3432 | * tasks if there is an imbalance. | |
1da177e4 | 3433 | */ |
70b97a7f | 3434 | static int load_balance(int this_cpu, struct rq *this_rq, |
d15bcfdb | 3435 | struct sched_domain *sd, enum cpu_idle_type idle, |
7c16ec58 | 3436 | int *balance, cpumask_t *cpus) |
1da177e4 | 3437 | { |
43010659 | 3438 | int ld_moved, all_pinned = 0, active_balance = 0, sd_idle = 0; |
1da177e4 | 3439 | struct sched_group *group; |
1da177e4 | 3440 | unsigned long imbalance; |
70b97a7f | 3441 | struct rq *busiest; |
fe2eea3f | 3442 | unsigned long flags; |
5969fe06 | 3443 | |
7c16ec58 MT |
3444 | cpus_setall(*cpus); |
3445 | ||
89c4710e SS |
3446 | /* |
3447 | * When power savings policy is enabled for the parent domain, idle | |
3448 | * sibling can pick up load irrespective of busy siblings. In this case, | |
dd41f596 | 3449 | * let the state of idle sibling percolate up as CPU_IDLE, instead of |
d15bcfdb | 3450 | * portraying it as CPU_NOT_IDLE. |
89c4710e | 3451 | */ |
d15bcfdb | 3452 | if (idle != CPU_NOT_IDLE && sd->flags & SD_SHARE_CPUPOWER && |
89c4710e | 3453 | !test_sd_parent(sd, SD_POWERSAVINGS_BALANCE)) |
5969fe06 | 3454 | sd_idle = 1; |
1da177e4 | 3455 | |
2d72376b | 3456 | schedstat_inc(sd, lb_count[idle]); |
1da177e4 | 3457 | |
0a2966b4 | 3458 | redo: |
c8cba857 | 3459 | update_shares(sd); |
0a2966b4 | 3460 | group = find_busiest_group(sd, this_cpu, &imbalance, idle, &sd_idle, |
7c16ec58 | 3461 | cpus, balance); |
783609c6 | 3462 | |
06066714 | 3463 | if (*balance == 0) |
783609c6 | 3464 | goto out_balanced; |
783609c6 | 3465 | |
1da177e4 LT |
3466 | if (!group) { |
3467 | schedstat_inc(sd, lb_nobusyg[idle]); | |
3468 | goto out_balanced; | |
3469 | } | |
3470 | ||
7c16ec58 | 3471 | busiest = find_busiest_queue(group, idle, imbalance, cpus); |
1da177e4 LT |
3472 | if (!busiest) { |
3473 | schedstat_inc(sd, lb_nobusyq[idle]); | |
3474 | goto out_balanced; | |
3475 | } | |
3476 | ||
db935dbd | 3477 | BUG_ON(busiest == this_rq); |
1da177e4 LT |
3478 | |
3479 | schedstat_add(sd, lb_imbalance[idle], imbalance); | |
3480 | ||
43010659 | 3481 | ld_moved = 0; |
1da177e4 LT |
3482 | if (busiest->nr_running > 1) { |
3483 | /* | |
3484 | * Attempt to move tasks. If find_busiest_group has found | |
3485 | * an imbalance but busiest->nr_running <= 1, the group is | |
43010659 | 3486 | * still unbalanced. ld_moved simply stays zero, so it is |
1da177e4 LT |
3487 | * correctly treated as an imbalance. |
3488 | */ | |
fe2eea3f | 3489 | local_irq_save(flags); |
e17224bf | 3490 | double_rq_lock(this_rq, busiest); |
43010659 | 3491 | ld_moved = move_tasks(this_rq, this_cpu, busiest, |
48f24c4d | 3492 | imbalance, sd, idle, &all_pinned); |
e17224bf | 3493 | double_rq_unlock(this_rq, busiest); |
fe2eea3f | 3494 | local_irq_restore(flags); |
81026794 | 3495 | |
46cb4b7c SS |
3496 | /* |
3497 | * some other cpu did the load balance for us. | |
3498 | */ | |
43010659 | 3499 | if (ld_moved && this_cpu != smp_processor_id()) |
46cb4b7c SS |
3500 | resched_cpu(this_cpu); |
3501 | ||
81026794 | 3502 | /* All tasks on this runqueue were pinned by CPU affinity */ |
0a2966b4 | 3503 | if (unlikely(all_pinned)) { |
7c16ec58 MT |
3504 | cpu_clear(cpu_of(busiest), *cpus); |
3505 | if (!cpus_empty(*cpus)) | |
0a2966b4 | 3506 | goto redo; |
81026794 | 3507 | goto out_balanced; |
0a2966b4 | 3508 | } |
1da177e4 | 3509 | } |
81026794 | 3510 | |
43010659 | 3511 | if (!ld_moved) { |
1da177e4 LT |
3512 | schedstat_inc(sd, lb_failed[idle]); |
3513 | sd->nr_balance_failed++; | |
3514 | ||
3515 | if (unlikely(sd->nr_balance_failed > sd->cache_nice_tries+2)) { | |
1da177e4 | 3516 | |
fe2eea3f | 3517 | spin_lock_irqsave(&busiest->lock, flags); |
fa3b6ddc SS |
3518 | |
3519 | /* don't kick the migration_thread, if the curr | |
3520 | * task on busiest cpu can't be moved to this_cpu | |
3521 | */ | |
3522 | if (!cpu_isset(this_cpu, busiest->curr->cpus_allowed)) { | |
fe2eea3f | 3523 | spin_unlock_irqrestore(&busiest->lock, flags); |
fa3b6ddc SS |
3524 | all_pinned = 1; |
3525 | goto out_one_pinned; | |
3526 | } | |
3527 | ||
1da177e4 LT |
3528 | if (!busiest->active_balance) { |
3529 | busiest->active_balance = 1; | |
3530 | busiest->push_cpu = this_cpu; | |
81026794 | 3531 | active_balance = 1; |
1da177e4 | 3532 | } |
fe2eea3f | 3533 | spin_unlock_irqrestore(&busiest->lock, flags); |
81026794 | 3534 | if (active_balance) |
1da177e4 LT |
3535 | wake_up_process(busiest->migration_thread); |
3536 | ||
3537 | /* | |
3538 | * We've kicked active balancing, reset the failure | |
3539 | * counter. | |
3540 | */ | |
39507451 | 3541 | sd->nr_balance_failed = sd->cache_nice_tries+1; |
1da177e4 | 3542 | } |
81026794 | 3543 | } else |
1da177e4 LT |
3544 | sd->nr_balance_failed = 0; |
3545 | ||
81026794 | 3546 | if (likely(!active_balance)) { |
1da177e4 LT |
3547 | /* We were unbalanced, so reset the balancing interval */ |
3548 | sd->balance_interval = sd->min_interval; | |
81026794 NP |
3549 | } else { |
3550 | /* | |
3551 | * If we've begun active balancing, start to back off. This | |
3552 | * case may not be covered by the all_pinned logic if there | |
3553 | * is only 1 task on the busy runqueue (because we don't call | |
3554 | * move_tasks). | |
3555 | */ | |
3556 | if (sd->balance_interval < sd->max_interval) | |
3557 | sd->balance_interval *= 2; | |
1da177e4 LT |
3558 | } |
3559 | ||
43010659 | 3560 | if (!ld_moved && !sd_idle && sd->flags & SD_SHARE_CPUPOWER && |
89c4710e | 3561 | !test_sd_parent(sd, SD_POWERSAVINGS_BALANCE)) |
c09595f6 PZ |
3562 | ld_moved = -1; |
3563 | ||
3564 | goto out; | |
1da177e4 LT |
3565 | |
3566 | out_balanced: | |
1da177e4 LT |
3567 | schedstat_inc(sd, lb_balanced[idle]); |
3568 | ||
16cfb1c0 | 3569 | sd->nr_balance_failed = 0; |
fa3b6ddc SS |
3570 | |
3571 | out_one_pinned: | |
1da177e4 | 3572 | /* tune up the balancing interval */ |
77391d71 NP |
3573 | if ((all_pinned && sd->balance_interval < MAX_PINNED_INTERVAL) || |
3574 | (sd->balance_interval < sd->max_interval)) | |
1da177e4 LT |
3575 | sd->balance_interval *= 2; |
3576 | ||
48f24c4d | 3577 | if (!sd_idle && sd->flags & SD_SHARE_CPUPOWER && |
89c4710e | 3578 | !test_sd_parent(sd, SD_POWERSAVINGS_BALANCE)) |
c09595f6 PZ |
3579 | ld_moved = -1; |
3580 | else | |
3581 | ld_moved = 0; | |
3582 | out: | |
c8cba857 PZ |
3583 | if (ld_moved) |
3584 | update_shares(sd); | |
c09595f6 | 3585 | return ld_moved; |
1da177e4 LT |
3586 | } |
3587 | ||
3588 | /* | |
3589 | * Check this_cpu to ensure it is balanced within domain. Attempt to move | |
3590 | * tasks if there is an imbalance. | |
3591 | * | |
d15bcfdb | 3592 | * Called from schedule when this_rq is about to become idle (CPU_NEWLY_IDLE). |
1da177e4 LT |
3593 | * this_rq is locked. |
3594 | */ | |
48f24c4d | 3595 | static int |
7c16ec58 MT |
3596 | load_balance_newidle(int this_cpu, struct rq *this_rq, struct sched_domain *sd, |
3597 | cpumask_t *cpus) | |
1da177e4 LT |
3598 | { |
3599 | struct sched_group *group; | |
70b97a7f | 3600 | struct rq *busiest = NULL; |
1da177e4 | 3601 | unsigned long imbalance; |
43010659 | 3602 | int ld_moved = 0; |
5969fe06 | 3603 | int sd_idle = 0; |
969bb4e4 | 3604 | int all_pinned = 0; |
7c16ec58 MT |
3605 | |
3606 | cpus_setall(*cpus); | |
5969fe06 | 3607 | |
89c4710e SS |
3608 | /* |
3609 | * When power savings policy is enabled for the parent domain, idle | |
3610 | * sibling can pick up load irrespective of busy siblings. In this case, | |
3611 | * let the state of idle sibling percolate up as IDLE, instead of | |
d15bcfdb | 3612 | * portraying it as CPU_NOT_IDLE. |
89c4710e SS |
3613 | */ |
3614 | if (sd->flags & SD_SHARE_CPUPOWER && | |
3615 | !test_sd_parent(sd, SD_POWERSAVINGS_BALANCE)) | |
5969fe06 | 3616 | sd_idle = 1; |
1da177e4 | 3617 | |
2d72376b | 3618 | schedstat_inc(sd, lb_count[CPU_NEWLY_IDLE]); |
0a2966b4 | 3619 | redo: |
3e5459b4 | 3620 | update_shares_locked(this_rq, sd); |
d15bcfdb | 3621 | group = find_busiest_group(sd, this_cpu, &imbalance, CPU_NEWLY_IDLE, |
7c16ec58 | 3622 | &sd_idle, cpus, NULL); |
1da177e4 | 3623 | if (!group) { |
d15bcfdb | 3624 | schedstat_inc(sd, lb_nobusyg[CPU_NEWLY_IDLE]); |
16cfb1c0 | 3625 | goto out_balanced; |
1da177e4 LT |
3626 | } |
3627 | ||
7c16ec58 | 3628 | busiest = find_busiest_queue(group, CPU_NEWLY_IDLE, imbalance, cpus); |
db935dbd | 3629 | if (!busiest) { |
d15bcfdb | 3630 | schedstat_inc(sd, lb_nobusyq[CPU_NEWLY_IDLE]); |
16cfb1c0 | 3631 | goto out_balanced; |
1da177e4 LT |
3632 | } |
3633 | ||
db935dbd NP |
3634 | BUG_ON(busiest == this_rq); |
3635 | ||
d15bcfdb | 3636 | schedstat_add(sd, lb_imbalance[CPU_NEWLY_IDLE], imbalance); |
d6d5cfaf | 3637 | |
43010659 | 3638 | ld_moved = 0; |
d6d5cfaf NP |
3639 | if (busiest->nr_running > 1) { |
3640 | /* Attempt to move tasks */ | |
3641 | double_lock_balance(this_rq, busiest); | |
6e82a3be IM |
3642 | /* this_rq->clock is already updated */ |
3643 | update_rq_clock(busiest); | |
43010659 | 3644 | ld_moved = move_tasks(this_rq, this_cpu, busiest, |
969bb4e4 SS |
3645 | imbalance, sd, CPU_NEWLY_IDLE, |
3646 | &all_pinned); | |
1b12bbc7 | 3647 | double_unlock_balance(this_rq, busiest); |
0a2966b4 | 3648 | |
969bb4e4 | 3649 | if (unlikely(all_pinned)) { |
7c16ec58 MT |
3650 | cpu_clear(cpu_of(busiest), *cpus); |
3651 | if (!cpus_empty(*cpus)) | |
0a2966b4 CL |
3652 | goto redo; |
3653 | } | |
d6d5cfaf NP |
3654 | } |
3655 | ||
43010659 | 3656 | if (!ld_moved) { |
d15bcfdb | 3657 | schedstat_inc(sd, lb_failed[CPU_NEWLY_IDLE]); |
89c4710e SS |
3658 | if (!sd_idle && sd->flags & SD_SHARE_CPUPOWER && |
3659 | !test_sd_parent(sd, SD_POWERSAVINGS_BALANCE)) | |
5969fe06 NP |
3660 | return -1; |
3661 | } else | |
16cfb1c0 | 3662 | sd->nr_balance_failed = 0; |
1da177e4 | 3663 | |
3e5459b4 | 3664 | update_shares_locked(this_rq, sd); |
43010659 | 3665 | return ld_moved; |
16cfb1c0 NP |
3666 | |
3667 | out_balanced: | |
d15bcfdb | 3668 | schedstat_inc(sd, lb_balanced[CPU_NEWLY_IDLE]); |
48f24c4d | 3669 | if (!sd_idle && sd->flags & SD_SHARE_CPUPOWER && |
89c4710e | 3670 | !test_sd_parent(sd, SD_POWERSAVINGS_BALANCE)) |
5969fe06 | 3671 | return -1; |
16cfb1c0 | 3672 | sd->nr_balance_failed = 0; |
48f24c4d | 3673 | |
16cfb1c0 | 3674 | return 0; |
1da177e4 LT |
3675 | } |
3676 | ||
3677 | /* | |
3678 | * idle_balance is called by schedule() if this_cpu is about to become | |
3679 | * idle. Attempts to pull tasks from other CPUs. | |
3680 | */ | |
70b97a7f | 3681 | static void idle_balance(int this_cpu, struct rq *this_rq) |
1da177e4 LT |
3682 | { |
3683 | struct sched_domain *sd; | |
dd41f596 IM |
3684 | int pulled_task = -1; |
3685 | unsigned long next_balance = jiffies + HZ; | |
7c16ec58 | 3686 | cpumask_t tmpmask; |
1da177e4 LT |
3687 | |
3688 | for_each_domain(this_cpu, sd) { | |
92c4ca5c CL |
3689 | unsigned long interval; |
3690 | ||
3691 | if (!(sd->flags & SD_LOAD_BALANCE)) | |
3692 | continue; | |
3693 | ||
3694 | if (sd->flags & SD_BALANCE_NEWIDLE) | |
48f24c4d | 3695 | /* If we've pulled tasks over stop searching: */ |
7c16ec58 MT |
3696 | pulled_task = load_balance_newidle(this_cpu, this_rq, |
3697 | sd, &tmpmask); | |
92c4ca5c CL |
3698 | |
3699 | interval = msecs_to_jiffies(sd->balance_interval); | |
3700 | if (time_after(next_balance, sd->last_balance + interval)) | |
3701 | next_balance = sd->last_balance + interval; | |
3702 | if (pulled_task) | |
3703 | break; | |
1da177e4 | 3704 | } |
dd41f596 | 3705 | if (pulled_task || time_after(jiffies, this_rq->next_balance)) { |
1bd77f2d CL |
3706 | /* |
3707 | * We are going idle. next_balance may be set based on | |
3708 | * a busy processor. So reset next_balance. | |
3709 | */ | |
3710 | this_rq->next_balance = next_balance; | |
dd41f596 | 3711 | } |
1da177e4 LT |
3712 | } |
3713 | ||
3714 | /* | |
3715 | * active_load_balance is run by migration threads. It pushes running tasks | |
3716 | * off the busiest CPU onto idle CPUs. It requires at least 1 task to be | |
3717 | * running on each physical CPU where possible, and avoids physical / | |
3718 | * logical imbalances. | |
3719 | * | |
3720 | * Called with busiest_rq locked. | |
3721 | */ | |
70b97a7f | 3722 | static void active_load_balance(struct rq *busiest_rq, int busiest_cpu) |
1da177e4 | 3723 | { |
39507451 | 3724 | int target_cpu = busiest_rq->push_cpu; |
70b97a7f IM |
3725 | struct sched_domain *sd; |
3726 | struct rq *target_rq; | |
39507451 | 3727 | |
48f24c4d | 3728 | /* Is there any task to move? */ |
39507451 | 3729 | if (busiest_rq->nr_running <= 1) |
39507451 NP |
3730 | return; |
3731 | ||
3732 | target_rq = cpu_rq(target_cpu); | |
1da177e4 LT |
3733 | |
3734 | /* | |
39507451 | 3735 | * This condition is "impossible", if it occurs |
41a2d6cf | 3736 | * we need to fix it. Originally reported by |
39507451 | 3737 | * Bjorn Helgaas on a 128-cpu setup. |
1da177e4 | 3738 | */ |
39507451 | 3739 | BUG_ON(busiest_rq == target_rq); |
1da177e4 | 3740 | |
39507451 NP |
3741 | /* move a task from busiest_rq to target_rq */ |
3742 | double_lock_balance(busiest_rq, target_rq); | |
6e82a3be IM |
3743 | update_rq_clock(busiest_rq); |
3744 | update_rq_clock(target_rq); | |
39507451 NP |
3745 | |
3746 | /* Search for an sd spanning us and the target CPU. */ | |
c96d145e | 3747 | for_each_domain(target_cpu, sd) { |
39507451 | 3748 | if ((sd->flags & SD_LOAD_BALANCE) && |
48f24c4d | 3749 | cpu_isset(busiest_cpu, sd->span)) |
39507451 | 3750 | break; |
c96d145e | 3751 | } |
39507451 | 3752 | |
48f24c4d | 3753 | if (likely(sd)) { |
2d72376b | 3754 | schedstat_inc(sd, alb_count); |
39507451 | 3755 | |
43010659 PW |
3756 | if (move_one_task(target_rq, target_cpu, busiest_rq, |
3757 | sd, CPU_IDLE)) | |
48f24c4d IM |
3758 | schedstat_inc(sd, alb_pushed); |
3759 | else | |
3760 | schedstat_inc(sd, alb_failed); | |
3761 | } | |
1b12bbc7 | 3762 | double_unlock_balance(busiest_rq, target_rq); |
1da177e4 LT |
3763 | } |
3764 | ||
46cb4b7c SS |
3765 | #ifdef CONFIG_NO_HZ |
3766 | static struct { | |
3767 | atomic_t load_balancer; | |
41a2d6cf | 3768 | cpumask_t cpu_mask; |
46cb4b7c SS |
3769 | } nohz ____cacheline_aligned = { |
3770 | .load_balancer = ATOMIC_INIT(-1), | |
3771 | .cpu_mask = CPU_MASK_NONE, | |
3772 | }; | |
3773 | ||
7835b98b | 3774 | /* |
46cb4b7c SS |
3775 | * This routine will try to nominate the ilb (idle load balancing) |
3776 | * owner among the cpus whose ticks are stopped. ilb owner will do the idle | |
3777 | * load balancing on behalf of all those cpus. If all the cpus in the system | |
3778 | * go into this tickless mode, then there will be no ilb owner (as there is | |
3779 | * no need for one) and all the cpus will sleep till the next wakeup event | |
3780 | * arrives... | |
3781 | * | |
3782 | * For the ilb owner, tick is not stopped. And this tick will be used | |
3783 | * for idle load balancing. ilb owner will still be part of | |
3784 | * nohz.cpu_mask.. | |
7835b98b | 3785 | * |
46cb4b7c SS |
3786 | * While stopping the tick, this cpu will become the ilb owner if there |
3787 | * is no other owner. And will be the owner till that cpu becomes busy | |
3788 | * or if all cpus in the system stop their ticks at which point | |
3789 | * there is no need for ilb owner. | |
3790 | * | |
3791 | * When the ilb owner becomes busy, it nominates another owner, during the | |
3792 | * next busy scheduler_tick() | |
3793 | */ | |
3794 | int select_nohz_load_balancer(int stop_tick) | |
3795 | { | |
3796 | int cpu = smp_processor_id(); | |
3797 | ||
3798 | if (stop_tick) { | |
3799 | cpu_set(cpu, nohz.cpu_mask); | |
3800 | cpu_rq(cpu)->in_nohz_recently = 1; | |
3801 | ||
3802 | /* | |
3803 | * If we are going offline and still the leader, give up! | |
3804 | */ | |
e761b772 | 3805 | if (!cpu_active(cpu) && |
46cb4b7c SS |
3806 | atomic_read(&nohz.load_balancer) == cpu) { |
3807 | if (atomic_cmpxchg(&nohz.load_balancer, cpu, -1) != cpu) | |
3808 | BUG(); | |
3809 | return 0; | |
3810 | } | |
3811 | ||
3812 | /* time for ilb owner also to sleep */ | |
3813 | if (cpus_weight(nohz.cpu_mask) == num_online_cpus()) { | |
3814 | if (atomic_read(&nohz.load_balancer) == cpu) | |
3815 | atomic_set(&nohz.load_balancer, -1); | |
3816 | return 0; | |
3817 | } | |
3818 | ||
3819 | if (atomic_read(&nohz.load_balancer) == -1) { | |
3820 | /* make me the ilb owner */ | |
3821 | if (atomic_cmpxchg(&nohz.load_balancer, -1, cpu) == -1) | |
3822 | return 1; | |
3823 | } else if (atomic_read(&nohz.load_balancer) == cpu) | |
3824 | return 1; | |
3825 | } else { | |
3826 | if (!cpu_isset(cpu, nohz.cpu_mask)) | |
3827 | return 0; | |
3828 | ||
3829 | cpu_clear(cpu, nohz.cpu_mask); | |
3830 | ||
3831 | if (atomic_read(&nohz.load_balancer) == cpu) | |
3832 | if (atomic_cmpxchg(&nohz.load_balancer, cpu, -1) != cpu) | |
3833 | BUG(); | |
3834 | } | |
3835 | return 0; | |
3836 | } | |
3837 | #endif | |
3838 | ||
3839 | static DEFINE_SPINLOCK(balancing); | |
3840 | ||
3841 | /* | |
7835b98b CL |
3842 | * It checks each scheduling domain to see if it is due to be balanced, |
3843 | * and initiates a balancing operation if so. | |
3844 | * | |
3845 | * Balancing parameters are set up in arch_init_sched_domains. | |
3846 | */ | |
a9957449 | 3847 | static void rebalance_domains(int cpu, enum cpu_idle_type idle) |
7835b98b | 3848 | { |
46cb4b7c SS |
3849 | int balance = 1; |
3850 | struct rq *rq = cpu_rq(cpu); | |
7835b98b CL |
3851 | unsigned long interval; |
3852 | struct sched_domain *sd; | |
46cb4b7c | 3853 | /* Earliest time when we have to do rebalance again */ |
c9819f45 | 3854 | unsigned long next_balance = jiffies + 60*HZ; |
f549da84 | 3855 | int update_next_balance = 0; |
d07355f5 | 3856 | int need_serialize; |
7c16ec58 | 3857 | cpumask_t tmp; |
1da177e4 | 3858 | |
46cb4b7c | 3859 | for_each_domain(cpu, sd) { |
1da177e4 LT |
3860 | if (!(sd->flags & SD_LOAD_BALANCE)) |
3861 | continue; | |
3862 | ||
3863 | interval = sd->balance_interval; | |
d15bcfdb | 3864 | if (idle != CPU_IDLE) |
1da177e4 LT |
3865 | interval *= sd->busy_factor; |
3866 | ||
3867 | /* scale ms to jiffies */ | |
3868 | interval = msecs_to_jiffies(interval); | |
3869 | if (unlikely(!interval)) | |
3870 | interval = 1; | |
dd41f596 IM |
3871 | if (interval > HZ*NR_CPUS/10) |
3872 | interval = HZ*NR_CPUS/10; | |
3873 | ||
d07355f5 | 3874 | need_serialize = sd->flags & SD_SERIALIZE; |
1da177e4 | 3875 | |
d07355f5 | 3876 | if (need_serialize) { |
08c183f3 CL |
3877 | if (!spin_trylock(&balancing)) |
3878 | goto out; | |
3879 | } | |
3880 | ||
c9819f45 | 3881 | if (time_after_eq(jiffies, sd->last_balance + interval)) { |
7c16ec58 | 3882 | if (load_balance(cpu, rq, sd, idle, &balance, &tmp)) { |
fa3b6ddc SS |
3883 | /* |
3884 | * We've pulled tasks over so either we're no | |
5969fe06 NP |
3885 | * longer idle, or one of our SMT siblings is |
3886 | * not idle. | |
3887 | */ | |
d15bcfdb | 3888 | idle = CPU_NOT_IDLE; |
1da177e4 | 3889 | } |
1bd77f2d | 3890 | sd->last_balance = jiffies; |
1da177e4 | 3891 | } |
d07355f5 | 3892 | if (need_serialize) |
08c183f3 CL |
3893 | spin_unlock(&balancing); |
3894 | out: | |
f549da84 | 3895 | if (time_after(next_balance, sd->last_balance + interval)) { |
c9819f45 | 3896 | next_balance = sd->last_balance + interval; |
f549da84 SS |
3897 | update_next_balance = 1; |
3898 | } | |
783609c6 SS |
3899 | |
3900 | /* | |
3901 | * Stop the load balance at this level. There is another | |
3902 | * CPU in our sched group which is doing load balancing more | |
3903 | * actively. | |
3904 | */ | |
3905 | if (!balance) | |
3906 | break; | |
1da177e4 | 3907 | } |
f549da84 SS |
3908 | |
3909 | /* | |
3910 | * next_balance will be updated only when there is a need. | |
3911 | * When the cpu is attached to null domain for ex, it will not be | |
3912 | * updated. | |
3913 | */ | |
3914 | if (likely(update_next_balance)) | |
3915 | rq->next_balance = next_balance; | |
46cb4b7c SS |
3916 | } |
3917 | ||
3918 | /* | |
3919 | * run_rebalance_domains is triggered when needed from the scheduler tick. | |
3920 | * In CONFIG_NO_HZ case, the idle load balance owner will do the | |
3921 | * rebalancing for all the cpus for whom scheduler ticks are stopped. | |
3922 | */ | |
3923 | static void run_rebalance_domains(struct softirq_action *h) | |
3924 | { | |
dd41f596 IM |
3925 | int this_cpu = smp_processor_id(); |
3926 | struct rq *this_rq = cpu_rq(this_cpu); | |
3927 | enum cpu_idle_type idle = this_rq->idle_at_tick ? | |
3928 | CPU_IDLE : CPU_NOT_IDLE; | |
46cb4b7c | 3929 | |
dd41f596 | 3930 | rebalance_domains(this_cpu, idle); |
46cb4b7c SS |
3931 | |
3932 | #ifdef CONFIG_NO_HZ | |
3933 | /* | |
3934 | * If this cpu is the owner for idle load balancing, then do the | |
3935 | * balancing on behalf of the other idle cpus whose ticks are | |
3936 | * stopped. | |
3937 | */ | |
dd41f596 IM |
3938 | if (this_rq->idle_at_tick && |
3939 | atomic_read(&nohz.load_balancer) == this_cpu) { | |
46cb4b7c SS |
3940 | cpumask_t cpus = nohz.cpu_mask; |
3941 | struct rq *rq; | |
3942 | int balance_cpu; | |
3943 | ||
dd41f596 | 3944 | cpu_clear(this_cpu, cpus); |
abcd083a | 3945 | for_each_cpu(balance_cpu, &cpus) { |
46cb4b7c SS |
3946 | /* |
3947 | * If this cpu gets work to do, stop the load balancing | |
3948 | * work being done for other cpus. Next load | |
3949 | * balancing owner will pick it up. | |
3950 | */ | |
3951 | if (need_resched()) | |
3952 | break; | |
3953 | ||
de0cf899 | 3954 | rebalance_domains(balance_cpu, CPU_IDLE); |
46cb4b7c SS |
3955 | |
3956 | rq = cpu_rq(balance_cpu); | |
dd41f596 IM |
3957 | if (time_after(this_rq->next_balance, rq->next_balance)) |
3958 | this_rq->next_balance = rq->next_balance; | |
46cb4b7c SS |
3959 | } |
3960 | } | |
3961 | #endif | |
3962 | } | |
3963 | ||
3964 | /* | |
3965 | * Trigger the SCHED_SOFTIRQ if it is time to do periodic load balancing. | |
3966 | * | |
3967 | * In case of CONFIG_NO_HZ, this is the place where we nominate a new | |
3968 | * idle load balancing owner or decide to stop the periodic load balancing, | |
3969 | * if the whole system is idle. | |
3970 | */ | |
dd41f596 | 3971 | static inline void trigger_load_balance(struct rq *rq, int cpu) |
46cb4b7c | 3972 | { |
46cb4b7c SS |
3973 | #ifdef CONFIG_NO_HZ |
3974 | /* | |
3975 | * If we were in the nohz mode recently and busy at the current | |
3976 | * scheduler tick, then check if we need to nominate new idle | |
3977 | * load balancer. | |
3978 | */ | |
3979 | if (rq->in_nohz_recently && !rq->idle_at_tick) { | |
3980 | rq->in_nohz_recently = 0; | |
3981 | ||
3982 | if (atomic_read(&nohz.load_balancer) == cpu) { | |
3983 | cpu_clear(cpu, nohz.cpu_mask); | |
3984 | atomic_set(&nohz.load_balancer, -1); | |
3985 | } | |
3986 | ||
3987 | if (atomic_read(&nohz.load_balancer) == -1) { | |
3988 | /* | |
3989 | * simple selection for now: Nominate the | |
3990 | * first cpu in the nohz list to be the next | |
3991 | * ilb owner. | |
3992 | * | |
3993 | * TBD: Traverse the sched domains and nominate | |
3994 | * the nearest cpu in the nohz.cpu_mask. | |
3995 | */ | |
3996 | int ilb = first_cpu(nohz.cpu_mask); | |
3997 | ||
434d53b0 | 3998 | if (ilb < nr_cpu_ids) |
46cb4b7c SS |
3999 | resched_cpu(ilb); |
4000 | } | |
4001 | } | |
4002 | ||
4003 | /* | |
4004 | * If this cpu is idle and doing idle load balancing for all the | |
4005 | * cpus with ticks stopped, is it time for that to stop? | |
4006 | */ | |
4007 | if (rq->idle_at_tick && atomic_read(&nohz.load_balancer) == cpu && | |
4008 | cpus_weight(nohz.cpu_mask) == num_online_cpus()) { | |
4009 | resched_cpu(cpu); | |
4010 | return; | |
4011 | } | |
4012 | ||
4013 | /* | |
4014 | * If this cpu is idle and the idle load balancing is done by | |
4015 | * someone else, then no need raise the SCHED_SOFTIRQ | |
4016 | */ | |
4017 | if (rq->idle_at_tick && atomic_read(&nohz.load_balancer) != cpu && | |
4018 | cpu_isset(cpu, nohz.cpu_mask)) | |
4019 | return; | |
4020 | #endif | |
4021 | if (time_after_eq(jiffies, rq->next_balance)) | |
4022 | raise_softirq(SCHED_SOFTIRQ); | |
1da177e4 | 4023 | } |
dd41f596 IM |
4024 | |
4025 | #else /* CONFIG_SMP */ | |
4026 | ||
1da177e4 LT |
4027 | /* |
4028 | * on UP we do not need to balance between CPUs: | |
4029 | */ | |
70b97a7f | 4030 | static inline void idle_balance(int cpu, struct rq *rq) |
1da177e4 LT |
4031 | { |
4032 | } | |
dd41f596 | 4033 | |
1da177e4 LT |
4034 | #endif |
4035 | ||
1da177e4 LT |
4036 | DEFINE_PER_CPU(struct kernel_stat, kstat); |
4037 | ||
4038 | EXPORT_PER_CPU_SYMBOL(kstat); | |
4039 | ||
4040 | /* | |
f06febc9 FM |
4041 | * Return any ns on the sched_clock that have not yet been banked in |
4042 | * @p in case that task is currently running. | |
1da177e4 | 4043 | */ |
bb34d92f | 4044 | unsigned long long task_delta_exec(struct task_struct *p) |
1da177e4 | 4045 | { |
1da177e4 | 4046 | unsigned long flags; |
41b86e9c | 4047 | struct rq *rq; |
bb34d92f | 4048 | u64 ns = 0; |
48f24c4d | 4049 | |
41b86e9c | 4050 | rq = task_rq_lock(p, &flags); |
1508487e | 4051 | |
051a1d1a | 4052 | if (task_current(rq, p)) { |
f06febc9 FM |
4053 | u64 delta_exec; |
4054 | ||
a8e504d2 IM |
4055 | update_rq_clock(rq); |
4056 | delta_exec = rq->clock - p->se.exec_start; | |
41b86e9c | 4057 | if ((s64)delta_exec > 0) |
bb34d92f | 4058 | ns = delta_exec; |
41b86e9c | 4059 | } |
48f24c4d | 4060 | |
41b86e9c | 4061 | task_rq_unlock(rq, &flags); |
48f24c4d | 4062 | |
1da177e4 LT |
4063 | return ns; |
4064 | } | |
4065 | ||
1da177e4 LT |
4066 | /* |
4067 | * Account user cpu time to a process. | |
4068 | * @p: the process that the cpu time gets accounted to | |
1da177e4 LT |
4069 | * @cputime: the cpu time spent in user space since the last update |
4070 | */ | |
4071 | void account_user_time(struct task_struct *p, cputime_t cputime) | |
4072 | { | |
4073 | struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat; | |
4074 | cputime64_t tmp; | |
4075 | ||
4076 | p->utime = cputime_add(p->utime, cputime); | |
f06febc9 | 4077 | account_group_user_time(p, cputime); |
1da177e4 LT |
4078 | |
4079 | /* Add user time to cpustat. */ | |
4080 | tmp = cputime_to_cputime64(cputime); | |
4081 | if (TASK_NICE(p) > 0) | |
4082 | cpustat->nice = cputime64_add(cpustat->nice, tmp); | |
4083 | else | |
4084 | cpustat->user = cputime64_add(cpustat->user, tmp); | |
49b5cf34 JL |
4085 | /* Account for user time used */ |
4086 | acct_update_integrals(p); | |
1da177e4 LT |
4087 | } |
4088 | ||
94886b84 LV |
4089 | /* |
4090 | * Account guest cpu time to a process. | |
4091 | * @p: the process that the cpu time gets accounted to | |
4092 | * @cputime: the cpu time spent in virtual machine since the last update | |
4093 | */ | |
f7402e03 | 4094 | static void account_guest_time(struct task_struct *p, cputime_t cputime) |
94886b84 LV |
4095 | { |
4096 | cputime64_t tmp; | |
4097 | struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat; | |
4098 | ||
4099 | tmp = cputime_to_cputime64(cputime); | |
4100 | ||
4101 | p->utime = cputime_add(p->utime, cputime); | |
f06febc9 | 4102 | account_group_user_time(p, cputime); |
94886b84 LV |
4103 | p->gtime = cputime_add(p->gtime, cputime); |
4104 | ||
4105 | cpustat->user = cputime64_add(cpustat->user, tmp); | |
4106 | cpustat->guest = cputime64_add(cpustat->guest, tmp); | |
4107 | } | |
4108 | ||
c66f08be MN |
4109 | /* |
4110 | * Account scaled user cpu time to a process. | |
4111 | * @p: the process that the cpu time gets accounted to | |
4112 | * @cputime: the cpu time spent in user space since the last update | |
4113 | */ | |
4114 | void account_user_time_scaled(struct task_struct *p, cputime_t cputime) | |
4115 | { | |
4116 | p->utimescaled = cputime_add(p->utimescaled, cputime); | |
4117 | } | |
4118 | ||
1da177e4 LT |
4119 | /* |
4120 | * Account system cpu time to a process. | |
4121 | * @p: the process that the cpu time gets accounted to | |
4122 | * @hardirq_offset: the offset to subtract from hardirq_count() | |
4123 | * @cputime: the cpu time spent in kernel space since the last update | |
4124 | */ | |
4125 | void account_system_time(struct task_struct *p, int hardirq_offset, | |
4126 | cputime_t cputime) | |
4127 | { | |
4128 | struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat; | |
70b97a7f | 4129 | struct rq *rq = this_rq(); |
1da177e4 LT |
4130 | cputime64_t tmp; |
4131 | ||
983ed7a6 HH |
4132 | if ((p->flags & PF_VCPU) && (irq_count() - hardirq_offset == 0)) { |
4133 | account_guest_time(p, cputime); | |
4134 | return; | |
4135 | } | |
94886b84 | 4136 | |
1da177e4 | 4137 | p->stime = cputime_add(p->stime, cputime); |
f06febc9 | 4138 | account_group_system_time(p, cputime); |
1da177e4 LT |
4139 | |
4140 | /* Add system time to cpustat. */ | |
4141 | tmp = cputime_to_cputime64(cputime); | |
4142 | if (hardirq_count() - hardirq_offset) | |
4143 | cpustat->irq = cputime64_add(cpustat->irq, tmp); | |
4144 | else if (softirq_count()) | |
4145 | cpustat->softirq = cputime64_add(cpustat->softirq, tmp); | |
cfb52856 | 4146 | else if (p != rq->idle) |
1da177e4 | 4147 | cpustat->system = cputime64_add(cpustat->system, tmp); |
cfb52856 | 4148 | else if (atomic_read(&rq->nr_iowait) > 0) |
1da177e4 LT |
4149 | cpustat->iowait = cputime64_add(cpustat->iowait, tmp); |
4150 | else | |
4151 | cpustat->idle = cputime64_add(cpustat->idle, tmp); | |
4152 | /* Account for system time used */ | |
4153 | acct_update_integrals(p); | |
1da177e4 LT |
4154 | } |
4155 | ||
c66f08be MN |
4156 | /* |
4157 | * Account scaled system cpu time to a process. | |
4158 | * @p: the process that the cpu time gets accounted to | |
4159 | * @hardirq_offset: the offset to subtract from hardirq_count() | |
4160 | * @cputime: the cpu time spent in kernel space since the last update | |
4161 | */ | |
4162 | void account_system_time_scaled(struct task_struct *p, cputime_t cputime) | |
4163 | { | |
4164 | p->stimescaled = cputime_add(p->stimescaled, cputime); | |
4165 | } | |
4166 | ||
1da177e4 LT |
4167 | /* |
4168 | * Account for involuntary wait time. | |
4169 | * @p: the process from which the cpu time has been stolen | |
4170 | * @steal: the cpu time spent in involuntary wait | |
4171 | */ | |
4172 | void account_steal_time(struct task_struct *p, cputime_t steal) | |
4173 | { | |
4174 | struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat; | |
4175 | cputime64_t tmp = cputime_to_cputime64(steal); | |
70b97a7f | 4176 | struct rq *rq = this_rq(); |
1da177e4 LT |
4177 | |
4178 | if (p == rq->idle) { | |
4179 | p->stime = cputime_add(p->stime, steal); | |
4180 | if (atomic_read(&rq->nr_iowait) > 0) | |
4181 | cpustat->iowait = cputime64_add(cpustat->iowait, tmp); | |
4182 | else | |
4183 | cpustat->idle = cputime64_add(cpustat->idle, tmp); | |
cfb52856 | 4184 | } else |
1da177e4 LT |
4185 | cpustat->steal = cputime64_add(cpustat->steal, tmp); |
4186 | } | |
4187 | ||
49048622 BS |
4188 | /* |
4189 | * Use precise platform statistics if available: | |
4190 | */ | |
4191 | #ifdef CONFIG_VIRT_CPU_ACCOUNTING | |
4192 | cputime_t task_utime(struct task_struct *p) | |
4193 | { | |
4194 | return p->utime; | |
4195 | } | |
4196 | ||
4197 | cputime_t task_stime(struct task_struct *p) | |
4198 | { | |
4199 | return p->stime; | |
4200 | } | |
4201 | #else | |
4202 | cputime_t task_utime(struct task_struct *p) | |
4203 | { | |
4204 | clock_t utime = cputime_to_clock_t(p->utime), | |
4205 | total = utime + cputime_to_clock_t(p->stime); | |
4206 | u64 temp; | |
4207 | ||
4208 | /* | |
4209 | * Use CFS's precise accounting: | |
4210 | */ | |
4211 | temp = (u64)nsec_to_clock_t(p->se.sum_exec_runtime); | |
4212 | ||
4213 | if (total) { | |
4214 | temp *= utime; | |
4215 | do_div(temp, total); | |
4216 | } | |
4217 | utime = (clock_t)temp; | |
4218 | ||
4219 | p->prev_utime = max(p->prev_utime, clock_t_to_cputime(utime)); | |
4220 | return p->prev_utime; | |
4221 | } | |
4222 | ||
4223 | cputime_t task_stime(struct task_struct *p) | |
4224 | { | |
4225 | clock_t stime; | |
4226 | ||
4227 | /* | |
4228 | * Use CFS's precise accounting. (we subtract utime from | |
4229 | * the total, to make sure the total observed by userspace | |
4230 | * grows monotonically - apps rely on that): | |
4231 | */ | |
4232 | stime = nsec_to_clock_t(p->se.sum_exec_runtime) - | |
4233 | cputime_to_clock_t(task_utime(p)); | |
4234 | ||
4235 | if (stime >= 0) | |
4236 | p->prev_stime = max(p->prev_stime, clock_t_to_cputime(stime)); | |
4237 | ||
4238 | return p->prev_stime; | |
4239 | } | |
4240 | #endif | |
4241 | ||
4242 | inline cputime_t task_gtime(struct task_struct *p) | |
4243 | { | |
4244 | return p->gtime; | |
4245 | } | |
4246 | ||
7835b98b CL |
4247 | /* |
4248 | * This function gets called by the timer code, with HZ frequency. | |
4249 | * We call it with interrupts disabled. | |
4250 | * | |
4251 | * It also gets called by the fork code, when changing the parent's | |
4252 | * timeslices. | |
4253 | */ | |
4254 | void scheduler_tick(void) | |
4255 | { | |
7835b98b CL |
4256 | int cpu = smp_processor_id(); |
4257 | struct rq *rq = cpu_rq(cpu); | |
dd41f596 | 4258 | struct task_struct *curr = rq->curr; |
3e51f33f PZ |
4259 | |
4260 | sched_clock_tick(); | |
dd41f596 IM |
4261 | |
4262 | spin_lock(&rq->lock); | |
3e51f33f | 4263 | update_rq_clock(rq); |
f1a438d8 | 4264 | update_cpu_load(rq); |
fa85ae24 | 4265 | curr->sched_class->task_tick(rq, curr, 0); |
dd41f596 | 4266 | spin_unlock(&rq->lock); |
7835b98b | 4267 | |
e418e1c2 | 4268 | #ifdef CONFIG_SMP |
dd41f596 IM |
4269 | rq->idle_at_tick = idle_cpu(cpu); |
4270 | trigger_load_balance(rq, cpu); | |
e418e1c2 | 4271 | #endif |
1da177e4 LT |
4272 | } |
4273 | ||
6cd8a4bb SR |
4274 | #if defined(CONFIG_PREEMPT) && (defined(CONFIG_DEBUG_PREEMPT) || \ |
4275 | defined(CONFIG_PREEMPT_TRACER)) | |
4276 | ||
4277 | static inline unsigned long get_parent_ip(unsigned long addr) | |
4278 | { | |
4279 | if (in_lock_functions(addr)) { | |
4280 | addr = CALLER_ADDR2; | |
4281 | if (in_lock_functions(addr)) | |
4282 | addr = CALLER_ADDR3; | |
4283 | } | |
4284 | return addr; | |
4285 | } | |
1da177e4 | 4286 | |
43627582 | 4287 | void __kprobes add_preempt_count(int val) |
1da177e4 | 4288 | { |
6cd8a4bb | 4289 | #ifdef CONFIG_DEBUG_PREEMPT |
1da177e4 LT |
4290 | /* |
4291 | * Underflow? | |
4292 | */ | |
9a11b49a IM |
4293 | if (DEBUG_LOCKS_WARN_ON((preempt_count() < 0))) |
4294 | return; | |
6cd8a4bb | 4295 | #endif |
1da177e4 | 4296 | preempt_count() += val; |
6cd8a4bb | 4297 | #ifdef CONFIG_DEBUG_PREEMPT |
1da177e4 LT |
4298 | /* |
4299 | * Spinlock count overflowing soon? | |
4300 | */ | |
33859f7f MOS |
4301 | DEBUG_LOCKS_WARN_ON((preempt_count() & PREEMPT_MASK) >= |
4302 | PREEMPT_MASK - 10); | |
6cd8a4bb SR |
4303 | #endif |
4304 | if (preempt_count() == val) | |
4305 | trace_preempt_off(CALLER_ADDR0, get_parent_ip(CALLER_ADDR1)); | |
1da177e4 LT |
4306 | } |
4307 | EXPORT_SYMBOL(add_preempt_count); | |
4308 | ||
43627582 | 4309 | void __kprobes sub_preempt_count(int val) |
1da177e4 | 4310 | { |
6cd8a4bb | 4311 | #ifdef CONFIG_DEBUG_PREEMPT |
1da177e4 LT |
4312 | /* |
4313 | * Underflow? | |
4314 | */ | |
7317d7b8 | 4315 | if (DEBUG_LOCKS_WARN_ON(val > preempt_count() - (!!kernel_locked()))) |
9a11b49a | 4316 | return; |
1da177e4 LT |
4317 | /* |
4318 | * Is the spinlock portion underflowing? | |
4319 | */ | |
9a11b49a IM |
4320 | if (DEBUG_LOCKS_WARN_ON((val < PREEMPT_MASK) && |
4321 | !(preempt_count() & PREEMPT_MASK))) | |
4322 | return; | |
6cd8a4bb | 4323 | #endif |
9a11b49a | 4324 | |
6cd8a4bb SR |
4325 | if (preempt_count() == val) |
4326 | trace_preempt_on(CALLER_ADDR0, get_parent_ip(CALLER_ADDR1)); | |
1da177e4 LT |
4327 | preempt_count() -= val; |
4328 | } | |
4329 | EXPORT_SYMBOL(sub_preempt_count); | |
4330 | ||
4331 | #endif | |
4332 | ||
4333 | /* | |
dd41f596 | 4334 | * Print scheduling while atomic bug: |
1da177e4 | 4335 | */ |
dd41f596 | 4336 | static noinline void __schedule_bug(struct task_struct *prev) |
1da177e4 | 4337 | { |
838225b4 SS |
4338 | struct pt_regs *regs = get_irq_regs(); |
4339 | ||
4340 | printk(KERN_ERR "BUG: scheduling while atomic: %s/%d/0x%08x\n", | |
4341 | prev->comm, prev->pid, preempt_count()); | |
4342 | ||
dd41f596 | 4343 | debug_show_held_locks(prev); |
e21f5b15 | 4344 | print_modules(); |
dd41f596 IM |
4345 | if (irqs_disabled()) |
4346 | print_irqtrace_events(prev); | |
838225b4 SS |
4347 | |
4348 | if (regs) | |
4349 | show_regs(regs); | |
4350 | else | |
4351 | dump_stack(); | |
dd41f596 | 4352 | } |
1da177e4 | 4353 | |
dd41f596 IM |
4354 | /* |
4355 | * Various schedule()-time debugging checks and statistics: | |
4356 | */ | |
4357 | static inline void schedule_debug(struct task_struct *prev) | |
4358 | { | |
1da177e4 | 4359 | /* |
41a2d6cf | 4360 | * Test if we are atomic. Since do_exit() needs to call into |
1da177e4 LT |
4361 | * schedule() atomically, we ignore that path for now. |
4362 | * Otherwise, whine if we are scheduling when we should not be. | |
4363 | */ | |
3f33a7ce | 4364 | if (unlikely(in_atomic_preempt_off() && !prev->exit_state)) |
dd41f596 IM |
4365 | __schedule_bug(prev); |
4366 | ||
1da177e4 LT |
4367 | profile_hit(SCHED_PROFILING, __builtin_return_address(0)); |
4368 | ||
2d72376b | 4369 | schedstat_inc(this_rq(), sched_count); |
b8efb561 IM |
4370 | #ifdef CONFIG_SCHEDSTATS |
4371 | if (unlikely(prev->lock_depth >= 0)) { | |
2d72376b IM |
4372 | schedstat_inc(this_rq(), bkl_count); |
4373 | schedstat_inc(prev, sched_info.bkl_count); | |
b8efb561 IM |
4374 | } |
4375 | #endif | |
dd41f596 IM |
4376 | } |
4377 | ||
4378 | /* | |
4379 | * Pick up the highest-prio task: | |
4380 | */ | |
4381 | static inline struct task_struct * | |
ff95f3df | 4382 | pick_next_task(struct rq *rq, struct task_struct *prev) |
dd41f596 | 4383 | { |
5522d5d5 | 4384 | const struct sched_class *class; |
dd41f596 | 4385 | struct task_struct *p; |
1da177e4 LT |
4386 | |
4387 | /* | |
dd41f596 IM |
4388 | * Optimization: we know that if all tasks are in |
4389 | * the fair class we can call that function directly: | |
1da177e4 | 4390 | */ |
dd41f596 | 4391 | if (likely(rq->nr_running == rq->cfs.nr_running)) { |
fb8d4724 | 4392 | p = fair_sched_class.pick_next_task(rq); |
dd41f596 IM |
4393 | if (likely(p)) |
4394 | return p; | |
1da177e4 LT |
4395 | } |
4396 | ||
dd41f596 IM |
4397 | class = sched_class_highest; |
4398 | for ( ; ; ) { | |
fb8d4724 | 4399 | p = class->pick_next_task(rq); |
dd41f596 IM |
4400 | if (p) |
4401 | return p; | |
4402 | /* | |
4403 | * Will never be NULL as the idle class always | |
4404 | * returns a non-NULL p: | |
4405 | */ | |
4406 | class = class->next; | |
4407 | } | |
4408 | } | |
1da177e4 | 4409 | |
dd41f596 IM |
4410 | /* |
4411 | * schedule() is the main scheduler function. | |
4412 | */ | |
4413 | asmlinkage void __sched schedule(void) | |
4414 | { | |
4415 | struct task_struct *prev, *next; | |
67ca7bde | 4416 | unsigned long *switch_count; |
dd41f596 | 4417 | struct rq *rq; |
31656519 | 4418 | int cpu; |
dd41f596 IM |
4419 | |
4420 | need_resched: | |
4421 | preempt_disable(); | |
4422 | cpu = smp_processor_id(); | |
4423 | rq = cpu_rq(cpu); | |
4424 | rcu_qsctr_inc(cpu); | |
4425 | prev = rq->curr; | |
4426 | switch_count = &prev->nivcsw; | |
4427 | ||
4428 | release_kernel_lock(prev); | |
4429 | need_resched_nonpreemptible: | |
4430 | ||
4431 | schedule_debug(prev); | |
1da177e4 | 4432 | |
31656519 | 4433 | if (sched_feat(HRTICK)) |
f333fdc9 | 4434 | hrtick_clear(rq); |
8f4d37ec | 4435 | |
8cd162ce | 4436 | spin_lock_irq(&rq->lock); |
3e51f33f | 4437 | update_rq_clock(rq); |
1e819950 | 4438 | clear_tsk_need_resched(prev); |
1da177e4 | 4439 | |
1da177e4 | 4440 | if (prev->state && !(preempt_count() & PREEMPT_ACTIVE)) { |
16882c1e | 4441 | if (unlikely(signal_pending_state(prev->state, prev))) |
1da177e4 | 4442 | prev->state = TASK_RUNNING; |
16882c1e | 4443 | else |
2e1cb74a | 4444 | deactivate_task(rq, prev, 1); |
dd41f596 | 4445 | switch_count = &prev->nvcsw; |
1da177e4 LT |
4446 | } |
4447 | ||
9a897c5a SR |
4448 | #ifdef CONFIG_SMP |
4449 | if (prev->sched_class->pre_schedule) | |
4450 | prev->sched_class->pre_schedule(rq, prev); | |
4451 | #endif | |
f65eda4f | 4452 | |
dd41f596 | 4453 | if (unlikely(!rq->nr_running)) |
1da177e4 | 4454 | idle_balance(cpu, rq); |
1da177e4 | 4455 | |
31ee529c | 4456 | prev->sched_class->put_prev_task(rq, prev); |
ff95f3df | 4457 | next = pick_next_task(rq, prev); |
1da177e4 | 4458 | |
1da177e4 | 4459 | if (likely(prev != next)) { |
673a90a1 DS |
4460 | sched_info_switch(prev, next); |
4461 | ||
1da177e4 LT |
4462 | rq->nr_switches++; |
4463 | rq->curr = next; | |
4464 | ++*switch_count; | |
4465 | ||
dd41f596 | 4466 | context_switch(rq, prev, next); /* unlocks the rq */ |
8f4d37ec PZ |
4467 | /* |
4468 | * the context switch might have flipped the stack from under | |
4469 | * us, hence refresh the local variables. | |
4470 | */ | |
4471 | cpu = smp_processor_id(); | |
4472 | rq = cpu_rq(cpu); | |
1da177e4 LT |
4473 | } else |
4474 | spin_unlock_irq(&rq->lock); | |
4475 | ||
8f4d37ec | 4476 | if (unlikely(reacquire_kernel_lock(current) < 0)) |
1da177e4 | 4477 | goto need_resched_nonpreemptible; |
8f4d37ec | 4478 | |
1da177e4 LT |
4479 | preempt_enable_no_resched(); |
4480 | if (unlikely(test_thread_flag(TIF_NEED_RESCHED))) | |
4481 | goto need_resched; | |
4482 | } | |
1da177e4 LT |
4483 | EXPORT_SYMBOL(schedule); |
4484 | ||
4485 | #ifdef CONFIG_PREEMPT | |
4486 | /* | |
2ed6e34f | 4487 | * this is the entry point to schedule() from in-kernel preemption |
41a2d6cf | 4488 | * off of preempt_enable. Kernel preemptions off return from interrupt |
1da177e4 LT |
4489 | * occur there and call schedule directly. |
4490 | */ | |
4491 | asmlinkage void __sched preempt_schedule(void) | |
4492 | { | |
4493 | struct thread_info *ti = current_thread_info(); | |
6478d880 | 4494 | |
1da177e4 LT |
4495 | /* |
4496 | * If there is a non-zero preempt_count or interrupts are disabled, | |
41a2d6cf | 4497 | * we do not want to preempt the current task. Just return.. |
1da177e4 | 4498 | */ |
beed33a8 | 4499 | if (likely(ti->preempt_count || irqs_disabled())) |
1da177e4 LT |
4500 | return; |
4501 | ||
3a5c359a AK |
4502 | do { |
4503 | add_preempt_count(PREEMPT_ACTIVE); | |
3a5c359a | 4504 | schedule(); |
3a5c359a | 4505 | sub_preempt_count(PREEMPT_ACTIVE); |
1da177e4 | 4506 | |
3a5c359a AK |
4507 | /* |
4508 | * Check again in case we missed a preemption opportunity | |
4509 | * between schedule and now. | |
4510 | */ | |
4511 | barrier(); | |
4512 | } while (unlikely(test_thread_flag(TIF_NEED_RESCHED))); | |
1da177e4 | 4513 | } |
1da177e4 LT |
4514 | EXPORT_SYMBOL(preempt_schedule); |
4515 | ||
4516 | /* | |
2ed6e34f | 4517 | * this is the entry point to schedule() from kernel preemption |
1da177e4 LT |
4518 | * off of irq context. |
4519 | * Note, that this is called and return with irqs disabled. This will | |
4520 | * protect us against recursive calling from irq. | |
4521 | */ | |
4522 | asmlinkage void __sched preempt_schedule_irq(void) | |
4523 | { | |
4524 | struct thread_info *ti = current_thread_info(); | |
6478d880 | 4525 | |
2ed6e34f | 4526 | /* Catch callers which need to be fixed */ |
1da177e4 LT |
4527 | BUG_ON(ti->preempt_count || !irqs_disabled()); |
4528 | ||
3a5c359a AK |
4529 | do { |
4530 | add_preempt_count(PREEMPT_ACTIVE); | |
3a5c359a AK |
4531 | local_irq_enable(); |
4532 | schedule(); | |
4533 | local_irq_disable(); | |
3a5c359a | 4534 | sub_preempt_count(PREEMPT_ACTIVE); |
1da177e4 | 4535 | |
3a5c359a AK |
4536 | /* |
4537 | * Check again in case we missed a preemption opportunity | |
4538 | * between schedule and now. | |
4539 | */ | |
4540 | barrier(); | |
4541 | } while (unlikely(test_thread_flag(TIF_NEED_RESCHED))); | |
1da177e4 LT |
4542 | } |
4543 | ||
4544 | #endif /* CONFIG_PREEMPT */ | |
4545 | ||
95cdf3b7 IM |
4546 | int default_wake_function(wait_queue_t *curr, unsigned mode, int sync, |
4547 | void *key) | |
1da177e4 | 4548 | { |
48f24c4d | 4549 | return try_to_wake_up(curr->private, mode, sync); |
1da177e4 | 4550 | } |
1da177e4 LT |
4551 | EXPORT_SYMBOL(default_wake_function); |
4552 | ||
4553 | /* | |
41a2d6cf IM |
4554 | * The core wakeup function. Non-exclusive wakeups (nr_exclusive == 0) just |
4555 | * wake everything up. If it's an exclusive wakeup (nr_exclusive == small +ve | |
1da177e4 LT |
4556 | * number) then we wake all the non-exclusive tasks and one exclusive task. |
4557 | * | |
4558 | * There are circumstances in which we can try to wake a task which has already | |
41a2d6cf | 4559 | * started to run but is not in state TASK_RUNNING. try_to_wake_up() returns |
1da177e4 LT |
4560 | * zero in this (rare) case, and we handle it by continuing to scan the queue. |
4561 | */ | |
4562 | static void __wake_up_common(wait_queue_head_t *q, unsigned int mode, | |
4563 | int nr_exclusive, int sync, void *key) | |
4564 | { | |
2e45874c | 4565 | wait_queue_t *curr, *next; |
1da177e4 | 4566 | |
2e45874c | 4567 | list_for_each_entry_safe(curr, next, &q->task_list, task_list) { |
48f24c4d IM |
4568 | unsigned flags = curr->flags; |
4569 | ||
1da177e4 | 4570 | if (curr->func(curr, mode, sync, key) && |
48f24c4d | 4571 | (flags & WQ_FLAG_EXCLUSIVE) && !--nr_exclusive) |
1da177e4 LT |
4572 | break; |
4573 | } | |
4574 | } | |
4575 | ||
4576 | /** | |
4577 | * __wake_up - wake up threads blocked on a waitqueue. | |
4578 | * @q: the waitqueue | |
4579 | * @mode: which threads | |
4580 | * @nr_exclusive: how many wake-one or wake-many threads to wake up | |
67be2dd1 | 4581 | * @key: is directly passed to the wakeup function |
1da177e4 | 4582 | */ |
7ad5b3a5 | 4583 | void __wake_up(wait_queue_head_t *q, unsigned int mode, |
95cdf3b7 | 4584 | int nr_exclusive, void *key) |
1da177e4 LT |
4585 | { |
4586 | unsigned long flags; | |
4587 | ||
4588 | spin_lock_irqsave(&q->lock, flags); | |
4589 | __wake_up_common(q, mode, nr_exclusive, 0, key); | |
4590 | spin_unlock_irqrestore(&q->lock, flags); | |
4591 | } | |
1da177e4 LT |
4592 | EXPORT_SYMBOL(__wake_up); |
4593 | ||
4594 | /* | |
4595 | * Same as __wake_up but called with the spinlock in wait_queue_head_t held. | |
4596 | */ | |
7ad5b3a5 | 4597 | void __wake_up_locked(wait_queue_head_t *q, unsigned int mode) |
1da177e4 LT |
4598 | { |
4599 | __wake_up_common(q, mode, 1, 0, NULL); | |
4600 | } | |
4601 | ||
4602 | /** | |
67be2dd1 | 4603 | * __wake_up_sync - wake up threads blocked on a waitqueue. |
1da177e4 LT |
4604 | * @q: the waitqueue |
4605 | * @mode: which threads | |
4606 | * @nr_exclusive: how many wake-one or wake-many threads to wake up | |
4607 | * | |
4608 | * The sync wakeup differs that the waker knows that it will schedule | |
4609 | * away soon, so while the target thread will be woken up, it will not | |
4610 | * be migrated to another CPU - ie. the two threads are 'synchronized' | |
4611 | * with each other. This can prevent needless bouncing between CPUs. | |
4612 | * | |
4613 | * On UP it can prevent extra preemption. | |
4614 | */ | |
7ad5b3a5 | 4615 | void |
95cdf3b7 | 4616 | __wake_up_sync(wait_queue_head_t *q, unsigned int mode, int nr_exclusive) |
1da177e4 LT |
4617 | { |
4618 | unsigned long flags; | |
4619 | int sync = 1; | |
4620 | ||
4621 | if (unlikely(!q)) | |
4622 | return; | |
4623 | ||
4624 | if (unlikely(!nr_exclusive)) | |
4625 | sync = 0; | |
4626 | ||
4627 | spin_lock_irqsave(&q->lock, flags); | |
4628 | __wake_up_common(q, mode, nr_exclusive, sync, NULL); | |
4629 | spin_unlock_irqrestore(&q->lock, flags); | |
4630 | } | |
4631 | EXPORT_SYMBOL_GPL(__wake_up_sync); /* For internal use only */ | |
4632 | ||
65eb3dc6 KD |
4633 | /** |
4634 | * complete: - signals a single thread waiting on this completion | |
4635 | * @x: holds the state of this particular completion | |
4636 | * | |
4637 | * This will wake up a single thread waiting on this completion. Threads will be | |
4638 | * awakened in the same order in which they were queued. | |
4639 | * | |
4640 | * See also complete_all(), wait_for_completion() and related routines. | |
4641 | */ | |
b15136e9 | 4642 | void complete(struct completion *x) |
1da177e4 LT |
4643 | { |
4644 | unsigned long flags; | |
4645 | ||
4646 | spin_lock_irqsave(&x->wait.lock, flags); | |
4647 | x->done++; | |
d9514f6c | 4648 | __wake_up_common(&x->wait, TASK_NORMAL, 1, 0, NULL); |
1da177e4 LT |
4649 | spin_unlock_irqrestore(&x->wait.lock, flags); |
4650 | } | |
4651 | EXPORT_SYMBOL(complete); | |
4652 | ||
65eb3dc6 KD |
4653 | /** |
4654 | * complete_all: - signals all threads waiting on this completion | |
4655 | * @x: holds the state of this particular completion | |
4656 | * | |
4657 | * This will wake up all threads waiting on this particular completion event. | |
4658 | */ | |
b15136e9 | 4659 | void complete_all(struct completion *x) |
1da177e4 LT |
4660 | { |
4661 | unsigned long flags; | |
4662 | ||
4663 | spin_lock_irqsave(&x->wait.lock, flags); | |
4664 | x->done += UINT_MAX/2; | |
d9514f6c | 4665 | __wake_up_common(&x->wait, TASK_NORMAL, 0, 0, NULL); |
1da177e4 LT |
4666 | spin_unlock_irqrestore(&x->wait.lock, flags); |
4667 | } | |
4668 | EXPORT_SYMBOL(complete_all); | |
4669 | ||
8cbbe86d AK |
4670 | static inline long __sched |
4671 | do_wait_for_common(struct completion *x, long timeout, int state) | |
1da177e4 | 4672 | { |
1da177e4 LT |
4673 | if (!x->done) { |
4674 | DECLARE_WAITQUEUE(wait, current); | |
4675 | ||
4676 | wait.flags |= WQ_FLAG_EXCLUSIVE; | |
4677 | __add_wait_queue_tail(&x->wait, &wait); | |
4678 | do { | |
94d3d824 | 4679 | if (signal_pending_state(state, current)) { |
ea71a546 ON |
4680 | timeout = -ERESTARTSYS; |
4681 | break; | |
8cbbe86d AK |
4682 | } |
4683 | __set_current_state(state); | |
1da177e4 LT |
4684 | spin_unlock_irq(&x->wait.lock); |
4685 | timeout = schedule_timeout(timeout); | |
4686 | spin_lock_irq(&x->wait.lock); | |
ea71a546 | 4687 | } while (!x->done && timeout); |
1da177e4 | 4688 | __remove_wait_queue(&x->wait, &wait); |
ea71a546 ON |
4689 | if (!x->done) |
4690 | return timeout; | |
1da177e4 LT |
4691 | } |
4692 | x->done--; | |
ea71a546 | 4693 | return timeout ?: 1; |
1da177e4 | 4694 | } |
1da177e4 | 4695 | |
8cbbe86d AK |
4696 | static long __sched |
4697 | wait_for_common(struct completion *x, long timeout, int state) | |
1da177e4 | 4698 | { |
1da177e4 LT |
4699 | might_sleep(); |
4700 | ||
4701 | spin_lock_irq(&x->wait.lock); | |
8cbbe86d | 4702 | timeout = do_wait_for_common(x, timeout, state); |
1da177e4 | 4703 | spin_unlock_irq(&x->wait.lock); |
8cbbe86d AK |
4704 | return timeout; |
4705 | } | |
1da177e4 | 4706 | |
65eb3dc6 KD |
4707 | /** |
4708 | * wait_for_completion: - waits for completion of a task | |
4709 | * @x: holds the state of this particular completion | |
4710 | * | |
4711 | * This waits to be signaled for completion of a specific task. It is NOT | |
4712 | * interruptible and there is no timeout. | |
4713 | * | |
4714 | * See also similar routines (i.e. wait_for_completion_timeout()) with timeout | |
4715 | * and interrupt capability. Also see complete(). | |
4716 | */ | |
b15136e9 | 4717 | void __sched wait_for_completion(struct completion *x) |
8cbbe86d AK |
4718 | { |
4719 | wait_for_common(x, MAX_SCHEDULE_TIMEOUT, TASK_UNINTERRUPTIBLE); | |
1da177e4 | 4720 | } |
8cbbe86d | 4721 | EXPORT_SYMBOL(wait_for_completion); |
1da177e4 | 4722 | |
65eb3dc6 KD |
4723 | /** |
4724 | * wait_for_completion_timeout: - waits for completion of a task (w/timeout) | |
4725 | * @x: holds the state of this particular completion | |
4726 | * @timeout: timeout value in jiffies | |
4727 | * | |
4728 | * This waits for either a completion of a specific task to be signaled or for a | |
4729 | * specified timeout to expire. The timeout is in jiffies. It is not | |
4730 | * interruptible. | |
4731 | */ | |
b15136e9 | 4732 | unsigned long __sched |
8cbbe86d | 4733 | wait_for_completion_timeout(struct completion *x, unsigned long timeout) |
1da177e4 | 4734 | { |
8cbbe86d | 4735 | return wait_for_common(x, timeout, TASK_UNINTERRUPTIBLE); |
1da177e4 | 4736 | } |
8cbbe86d | 4737 | EXPORT_SYMBOL(wait_for_completion_timeout); |
1da177e4 | 4738 | |
65eb3dc6 KD |
4739 | /** |
4740 | * wait_for_completion_interruptible: - waits for completion of a task (w/intr) | |
4741 | * @x: holds the state of this particular completion | |
4742 | * | |
4743 | * This waits for completion of a specific task to be signaled. It is | |
4744 | * interruptible. | |
4745 | */ | |
8cbbe86d | 4746 | int __sched wait_for_completion_interruptible(struct completion *x) |
0fec171c | 4747 | { |
51e97990 AK |
4748 | long t = wait_for_common(x, MAX_SCHEDULE_TIMEOUT, TASK_INTERRUPTIBLE); |
4749 | if (t == -ERESTARTSYS) | |
4750 | return t; | |
4751 | return 0; | |
0fec171c | 4752 | } |
8cbbe86d | 4753 | EXPORT_SYMBOL(wait_for_completion_interruptible); |
1da177e4 | 4754 | |
65eb3dc6 KD |
4755 | /** |
4756 | * wait_for_completion_interruptible_timeout: - waits for completion (w/(to,intr)) | |
4757 | * @x: holds the state of this particular completion | |
4758 | * @timeout: timeout value in jiffies | |
4759 | * | |
4760 | * This waits for either a completion of a specific task to be signaled or for a | |
4761 | * specified timeout to expire. It is interruptible. The timeout is in jiffies. | |
4762 | */ | |
b15136e9 | 4763 | unsigned long __sched |
8cbbe86d AK |
4764 | wait_for_completion_interruptible_timeout(struct completion *x, |
4765 | unsigned long timeout) | |
0fec171c | 4766 | { |
8cbbe86d | 4767 | return wait_for_common(x, timeout, TASK_INTERRUPTIBLE); |
0fec171c | 4768 | } |
8cbbe86d | 4769 | EXPORT_SYMBOL(wait_for_completion_interruptible_timeout); |
1da177e4 | 4770 | |
65eb3dc6 KD |
4771 | /** |
4772 | * wait_for_completion_killable: - waits for completion of a task (killable) | |
4773 | * @x: holds the state of this particular completion | |
4774 | * | |
4775 | * This waits to be signaled for completion of a specific task. It can be | |
4776 | * interrupted by a kill signal. | |
4777 | */ | |
009e577e MW |
4778 | int __sched wait_for_completion_killable(struct completion *x) |
4779 | { | |
4780 | long t = wait_for_common(x, MAX_SCHEDULE_TIMEOUT, TASK_KILLABLE); | |
4781 | if (t == -ERESTARTSYS) | |
4782 | return t; | |
4783 | return 0; | |
4784 | } | |
4785 | EXPORT_SYMBOL(wait_for_completion_killable); | |
4786 | ||
be4de352 DC |
4787 | /** |
4788 | * try_wait_for_completion - try to decrement a completion without blocking | |
4789 | * @x: completion structure | |
4790 | * | |
4791 | * Returns: 0 if a decrement cannot be done without blocking | |
4792 | * 1 if a decrement succeeded. | |
4793 | * | |
4794 | * If a completion is being used as a counting completion, | |
4795 | * attempt to decrement the counter without blocking. This | |
4796 | * enables us to avoid waiting if the resource the completion | |
4797 | * is protecting is not available. | |
4798 | */ | |
4799 | bool try_wait_for_completion(struct completion *x) | |
4800 | { | |
4801 | int ret = 1; | |
4802 | ||
4803 | spin_lock_irq(&x->wait.lock); | |
4804 | if (!x->done) | |
4805 | ret = 0; | |
4806 | else | |
4807 | x->done--; | |
4808 | spin_unlock_irq(&x->wait.lock); | |
4809 | return ret; | |
4810 | } | |
4811 | EXPORT_SYMBOL(try_wait_for_completion); | |
4812 | ||
4813 | /** | |
4814 | * completion_done - Test to see if a completion has any waiters | |
4815 | * @x: completion structure | |
4816 | * | |
4817 | * Returns: 0 if there are waiters (wait_for_completion() in progress) | |
4818 | * 1 if there are no waiters. | |
4819 | * | |
4820 | */ | |
4821 | bool completion_done(struct completion *x) | |
4822 | { | |
4823 | int ret = 1; | |
4824 | ||
4825 | spin_lock_irq(&x->wait.lock); | |
4826 | if (!x->done) | |
4827 | ret = 0; | |
4828 | spin_unlock_irq(&x->wait.lock); | |
4829 | return ret; | |
4830 | } | |
4831 | EXPORT_SYMBOL(completion_done); | |
4832 | ||
8cbbe86d AK |
4833 | static long __sched |
4834 | sleep_on_common(wait_queue_head_t *q, int state, long timeout) | |
1da177e4 | 4835 | { |
0fec171c IM |
4836 | unsigned long flags; |
4837 | wait_queue_t wait; | |
4838 | ||
4839 | init_waitqueue_entry(&wait, current); | |
1da177e4 | 4840 | |
8cbbe86d | 4841 | __set_current_state(state); |
1da177e4 | 4842 | |
8cbbe86d AK |
4843 | spin_lock_irqsave(&q->lock, flags); |
4844 | __add_wait_queue(q, &wait); | |
4845 | spin_unlock(&q->lock); | |
4846 | timeout = schedule_timeout(timeout); | |
4847 | spin_lock_irq(&q->lock); | |
4848 | __remove_wait_queue(q, &wait); | |
4849 | spin_unlock_irqrestore(&q->lock, flags); | |
4850 | ||
4851 | return timeout; | |
4852 | } | |
4853 | ||
4854 | void __sched interruptible_sleep_on(wait_queue_head_t *q) | |
4855 | { | |
4856 | sleep_on_common(q, TASK_INTERRUPTIBLE, MAX_SCHEDULE_TIMEOUT); | |
1da177e4 | 4857 | } |
1da177e4 LT |
4858 | EXPORT_SYMBOL(interruptible_sleep_on); |
4859 | ||
0fec171c | 4860 | long __sched |
95cdf3b7 | 4861 | interruptible_sleep_on_timeout(wait_queue_head_t *q, long timeout) |
1da177e4 | 4862 | { |
8cbbe86d | 4863 | return sleep_on_common(q, TASK_INTERRUPTIBLE, timeout); |
1da177e4 | 4864 | } |
1da177e4 LT |
4865 | EXPORT_SYMBOL(interruptible_sleep_on_timeout); |
4866 | ||
0fec171c | 4867 | void __sched sleep_on(wait_queue_head_t *q) |
1da177e4 | 4868 | { |
8cbbe86d | 4869 | sleep_on_common(q, TASK_UNINTERRUPTIBLE, MAX_SCHEDULE_TIMEOUT); |
1da177e4 | 4870 | } |
1da177e4 LT |
4871 | EXPORT_SYMBOL(sleep_on); |
4872 | ||
0fec171c | 4873 | long __sched sleep_on_timeout(wait_queue_head_t *q, long timeout) |
1da177e4 | 4874 | { |
8cbbe86d | 4875 | return sleep_on_common(q, TASK_UNINTERRUPTIBLE, timeout); |
1da177e4 | 4876 | } |
1da177e4 LT |
4877 | EXPORT_SYMBOL(sleep_on_timeout); |
4878 | ||
b29739f9 IM |
4879 | #ifdef CONFIG_RT_MUTEXES |
4880 | ||
4881 | /* | |
4882 | * rt_mutex_setprio - set the current priority of a task | |
4883 | * @p: task | |
4884 | * @prio: prio value (kernel-internal form) | |
4885 | * | |
4886 | * This function changes the 'effective' priority of a task. It does | |
4887 | * not touch ->normal_prio like __setscheduler(). | |
4888 | * | |
4889 | * Used by the rt_mutex code to implement priority inheritance logic. | |
4890 | */ | |
36c8b586 | 4891 | void rt_mutex_setprio(struct task_struct *p, int prio) |
b29739f9 IM |
4892 | { |
4893 | unsigned long flags; | |
83b699ed | 4894 | int oldprio, on_rq, running; |
70b97a7f | 4895 | struct rq *rq; |
cb469845 | 4896 | const struct sched_class *prev_class = p->sched_class; |
b29739f9 IM |
4897 | |
4898 | BUG_ON(prio < 0 || prio > MAX_PRIO); | |
4899 | ||
4900 | rq = task_rq_lock(p, &flags); | |
a8e504d2 | 4901 | update_rq_clock(rq); |
b29739f9 | 4902 | |
d5f9f942 | 4903 | oldprio = p->prio; |
dd41f596 | 4904 | on_rq = p->se.on_rq; |
051a1d1a | 4905 | running = task_current(rq, p); |
0e1f3483 | 4906 | if (on_rq) |
69be72c1 | 4907 | dequeue_task(rq, p, 0); |
0e1f3483 HS |
4908 | if (running) |
4909 | p->sched_class->put_prev_task(rq, p); | |
dd41f596 IM |
4910 | |
4911 | if (rt_prio(prio)) | |
4912 | p->sched_class = &rt_sched_class; | |
4913 | else | |
4914 | p->sched_class = &fair_sched_class; | |
4915 | ||
b29739f9 IM |
4916 | p->prio = prio; |
4917 | ||
0e1f3483 HS |
4918 | if (running) |
4919 | p->sched_class->set_curr_task(rq); | |
dd41f596 | 4920 | if (on_rq) { |
8159f87e | 4921 | enqueue_task(rq, p, 0); |
cb469845 SR |
4922 | |
4923 | check_class_changed(rq, p, prev_class, oldprio, running); | |
b29739f9 IM |
4924 | } |
4925 | task_rq_unlock(rq, &flags); | |
4926 | } | |
4927 | ||
4928 | #endif | |
4929 | ||
36c8b586 | 4930 | void set_user_nice(struct task_struct *p, long nice) |
1da177e4 | 4931 | { |
dd41f596 | 4932 | int old_prio, delta, on_rq; |
1da177e4 | 4933 | unsigned long flags; |
70b97a7f | 4934 | struct rq *rq; |
1da177e4 LT |
4935 | |
4936 | if (TASK_NICE(p) == nice || nice < -20 || nice > 19) | |
4937 | return; | |
4938 | /* | |
4939 | * We have to be careful, if called from sys_setpriority(), | |
4940 | * the task might be in the middle of scheduling on another CPU. | |
4941 | */ | |
4942 | rq = task_rq_lock(p, &flags); | |
a8e504d2 | 4943 | update_rq_clock(rq); |
1da177e4 LT |
4944 | /* |
4945 | * The RT priorities are set via sched_setscheduler(), but we still | |
4946 | * allow the 'normal' nice value to be set - but as expected | |
4947 | * it wont have any effect on scheduling until the task is | |
dd41f596 | 4948 | * SCHED_FIFO/SCHED_RR: |
1da177e4 | 4949 | */ |
e05606d3 | 4950 | if (task_has_rt_policy(p)) { |
1da177e4 LT |
4951 | p->static_prio = NICE_TO_PRIO(nice); |
4952 | goto out_unlock; | |
4953 | } | |
dd41f596 | 4954 | on_rq = p->se.on_rq; |
c09595f6 | 4955 | if (on_rq) |
69be72c1 | 4956 | dequeue_task(rq, p, 0); |
1da177e4 | 4957 | |
1da177e4 | 4958 | p->static_prio = NICE_TO_PRIO(nice); |
2dd73a4f | 4959 | set_load_weight(p); |
b29739f9 IM |
4960 | old_prio = p->prio; |
4961 | p->prio = effective_prio(p); | |
4962 | delta = p->prio - old_prio; | |
1da177e4 | 4963 | |
dd41f596 | 4964 | if (on_rq) { |
8159f87e | 4965 | enqueue_task(rq, p, 0); |
1da177e4 | 4966 | /* |
d5f9f942 AM |
4967 | * If the task increased its priority or is running and |
4968 | * lowered its priority, then reschedule its CPU: | |
1da177e4 | 4969 | */ |
d5f9f942 | 4970 | if (delta < 0 || (delta > 0 && task_running(rq, p))) |
1da177e4 LT |
4971 | resched_task(rq->curr); |
4972 | } | |
4973 | out_unlock: | |
4974 | task_rq_unlock(rq, &flags); | |
4975 | } | |
1da177e4 LT |
4976 | EXPORT_SYMBOL(set_user_nice); |
4977 | ||
e43379f1 MM |
4978 | /* |
4979 | * can_nice - check if a task can reduce its nice value | |
4980 | * @p: task | |
4981 | * @nice: nice value | |
4982 | */ | |
36c8b586 | 4983 | int can_nice(const struct task_struct *p, const int nice) |
e43379f1 | 4984 | { |
024f4747 MM |
4985 | /* convert nice value [19,-20] to rlimit style value [1,40] */ |
4986 | int nice_rlim = 20 - nice; | |
48f24c4d | 4987 | |
e43379f1 MM |
4988 | return (nice_rlim <= p->signal->rlim[RLIMIT_NICE].rlim_cur || |
4989 | capable(CAP_SYS_NICE)); | |
4990 | } | |
4991 | ||
1da177e4 LT |
4992 | #ifdef __ARCH_WANT_SYS_NICE |
4993 | ||
4994 | /* | |
4995 | * sys_nice - change the priority of the current process. | |
4996 | * @increment: priority increment | |
4997 | * | |
4998 | * sys_setpriority is a more generic, but much slower function that | |
4999 | * does similar things. | |
5000 | */ | |
5001 | asmlinkage long sys_nice(int increment) | |
5002 | { | |
48f24c4d | 5003 | long nice, retval; |
1da177e4 LT |
5004 | |
5005 | /* | |
5006 | * Setpriority might change our priority at the same moment. | |
5007 | * We don't have to worry. Conceptually one call occurs first | |
5008 | * and we have a single winner. | |
5009 | */ | |
e43379f1 MM |
5010 | if (increment < -40) |
5011 | increment = -40; | |
1da177e4 LT |
5012 | if (increment > 40) |
5013 | increment = 40; | |
5014 | ||
5015 | nice = PRIO_TO_NICE(current->static_prio) + increment; | |
5016 | if (nice < -20) | |
5017 | nice = -20; | |
5018 | if (nice > 19) | |
5019 | nice = 19; | |
5020 | ||
e43379f1 MM |
5021 | if (increment < 0 && !can_nice(current, nice)) |
5022 | return -EPERM; | |
5023 | ||
1da177e4 LT |
5024 | retval = security_task_setnice(current, nice); |
5025 | if (retval) | |
5026 | return retval; | |
5027 | ||
5028 | set_user_nice(current, nice); | |
5029 | return 0; | |
5030 | } | |
5031 | ||
5032 | #endif | |
5033 | ||
5034 | /** | |
5035 | * task_prio - return the priority value of a given task. | |
5036 | * @p: the task in question. | |
5037 | * | |
5038 | * This is the priority value as seen by users in /proc. | |
5039 | * RT tasks are offset by -200. Normal tasks are centered | |
5040 | * around 0, value goes from -16 to +15. | |
5041 | */ | |
36c8b586 | 5042 | int task_prio(const struct task_struct *p) |
1da177e4 LT |
5043 | { |
5044 | return p->prio - MAX_RT_PRIO; | |
5045 | } | |
5046 | ||
5047 | /** | |
5048 | * task_nice - return the nice value of a given task. | |
5049 | * @p: the task in question. | |
5050 | */ | |
36c8b586 | 5051 | int task_nice(const struct task_struct *p) |
1da177e4 LT |
5052 | { |
5053 | return TASK_NICE(p); | |
5054 | } | |
150d8bed | 5055 | EXPORT_SYMBOL(task_nice); |
1da177e4 LT |
5056 | |
5057 | /** | |
5058 | * idle_cpu - is a given cpu idle currently? | |
5059 | * @cpu: the processor in question. | |
5060 | */ | |
5061 | int idle_cpu(int cpu) | |
5062 | { | |
5063 | return cpu_curr(cpu) == cpu_rq(cpu)->idle; | |
5064 | } | |
5065 | ||
1da177e4 LT |
5066 | /** |
5067 | * idle_task - return the idle task for a given cpu. | |
5068 | * @cpu: the processor in question. | |
5069 | */ | |
36c8b586 | 5070 | struct task_struct *idle_task(int cpu) |
1da177e4 LT |
5071 | { |
5072 | return cpu_rq(cpu)->idle; | |
5073 | } | |
5074 | ||
5075 | /** | |
5076 | * find_process_by_pid - find a process with a matching PID value. | |
5077 | * @pid: the pid in question. | |
5078 | */ | |
a9957449 | 5079 | static struct task_struct *find_process_by_pid(pid_t pid) |
1da177e4 | 5080 | { |
228ebcbe | 5081 | return pid ? find_task_by_vpid(pid) : current; |
1da177e4 LT |
5082 | } |
5083 | ||
5084 | /* Actually do priority change: must hold rq lock. */ | |
dd41f596 IM |
5085 | static void |
5086 | __setscheduler(struct rq *rq, struct task_struct *p, int policy, int prio) | |
1da177e4 | 5087 | { |
dd41f596 | 5088 | BUG_ON(p->se.on_rq); |
48f24c4d | 5089 | |
1da177e4 | 5090 | p->policy = policy; |
dd41f596 IM |
5091 | switch (p->policy) { |
5092 | case SCHED_NORMAL: | |
5093 | case SCHED_BATCH: | |
5094 | case SCHED_IDLE: | |
5095 | p->sched_class = &fair_sched_class; | |
5096 | break; | |
5097 | case SCHED_FIFO: | |
5098 | case SCHED_RR: | |
5099 | p->sched_class = &rt_sched_class; | |
5100 | break; | |
5101 | } | |
5102 | ||
1da177e4 | 5103 | p->rt_priority = prio; |
b29739f9 IM |
5104 | p->normal_prio = normal_prio(p); |
5105 | /* we are holding p->pi_lock already */ | |
5106 | p->prio = rt_mutex_getprio(p); | |
2dd73a4f | 5107 | set_load_weight(p); |
1da177e4 LT |
5108 | } |
5109 | ||
961ccddd RR |
5110 | static int __sched_setscheduler(struct task_struct *p, int policy, |
5111 | struct sched_param *param, bool user) | |
1da177e4 | 5112 | { |
83b699ed | 5113 | int retval, oldprio, oldpolicy = -1, on_rq, running; |
1da177e4 | 5114 | unsigned long flags; |
cb469845 | 5115 | const struct sched_class *prev_class = p->sched_class; |
70b97a7f | 5116 | struct rq *rq; |
1da177e4 | 5117 | |
66e5393a SR |
5118 | /* may grab non-irq protected spin_locks */ |
5119 | BUG_ON(in_interrupt()); | |
1da177e4 LT |
5120 | recheck: |
5121 | /* double check policy once rq lock held */ | |
5122 | if (policy < 0) | |
5123 | policy = oldpolicy = p->policy; | |
5124 | else if (policy != SCHED_FIFO && policy != SCHED_RR && | |
dd41f596 IM |
5125 | policy != SCHED_NORMAL && policy != SCHED_BATCH && |
5126 | policy != SCHED_IDLE) | |
b0a9499c | 5127 | return -EINVAL; |
1da177e4 LT |
5128 | /* |
5129 | * Valid priorities for SCHED_FIFO and SCHED_RR are | |
dd41f596 IM |
5130 | * 1..MAX_USER_RT_PRIO-1, valid priority for SCHED_NORMAL, |
5131 | * SCHED_BATCH and SCHED_IDLE is 0. | |
1da177e4 LT |
5132 | */ |
5133 | if (param->sched_priority < 0 || | |
95cdf3b7 | 5134 | (p->mm && param->sched_priority > MAX_USER_RT_PRIO-1) || |
d46523ea | 5135 | (!p->mm && param->sched_priority > MAX_RT_PRIO-1)) |
1da177e4 | 5136 | return -EINVAL; |
e05606d3 | 5137 | if (rt_policy(policy) != (param->sched_priority != 0)) |
1da177e4 LT |
5138 | return -EINVAL; |
5139 | ||
37e4ab3f OC |
5140 | /* |
5141 | * Allow unprivileged RT tasks to decrease priority: | |
5142 | */ | |
961ccddd | 5143 | if (user && !capable(CAP_SYS_NICE)) { |
e05606d3 | 5144 | if (rt_policy(policy)) { |
8dc3e909 | 5145 | unsigned long rlim_rtprio; |
8dc3e909 ON |
5146 | |
5147 | if (!lock_task_sighand(p, &flags)) | |
5148 | return -ESRCH; | |
5149 | rlim_rtprio = p->signal->rlim[RLIMIT_RTPRIO].rlim_cur; | |
5150 | unlock_task_sighand(p, &flags); | |
5151 | ||
5152 | /* can't set/change the rt policy */ | |
5153 | if (policy != p->policy && !rlim_rtprio) | |
5154 | return -EPERM; | |
5155 | ||
5156 | /* can't increase priority */ | |
5157 | if (param->sched_priority > p->rt_priority && | |
5158 | param->sched_priority > rlim_rtprio) | |
5159 | return -EPERM; | |
5160 | } | |
dd41f596 IM |
5161 | /* |
5162 | * Like positive nice levels, dont allow tasks to | |
5163 | * move out of SCHED_IDLE either: | |
5164 | */ | |
5165 | if (p->policy == SCHED_IDLE && policy != SCHED_IDLE) | |
5166 | return -EPERM; | |
5fe1d75f | 5167 | |
37e4ab3f OC |
5168 | /* can't change other user's priorities */ |
5169 | if ((current->euid != p->euid) && | |
5170 | (current->euid != p->uid)) | |
5171 | return -EPERM; | |
5172 | } | |
1da177e4 | 5173 | |
725aad24 | 5174 | if (user) { |
b68aa230 | 5175 | #ifdef CONFIG_RT_GROUP_SCHED |
725aad24 JF |
5176 | /* |
5177 | * Do not allow realtime tasks into groups that have no runtime | |
5178 | * assigned. | |
5179 | */ | |
9a7e0b18 PZ |
5180 | if (rt_bandwidth_enabled() && rt_policy(policy) && |
5181 | task_group(p)->rt_bandwidth.rt_runtime == 0) | |
725aad24 | 5182 | return -EPERM; |
b68aa230 PZ |
5183 | #endif |
5184 | ||
725aad24 JF |
5185 | retval = security_task_setscheduler(p, policy, param); |
5186 | if (retval) | |
5187 | return retval; | |
5188 | } | |
5189 | ||
b29739f9 IM |
5190 | /* |
5191 | * make sure no PI-waiters arrive (or leave) while we are | |
5192 | * changing the priority of the task: | |
5193 | */ | |
5194 | spin_lock_irqsave(&p->pi_lock, flags); | |
1da177e4 LT |
5195 | /* |
5196 | * To be able to change p->policy safely, the apropriate | |
5197 | * runqueue lock must be held. | |
5198 | */ | |
b29739f9 | 5199 | rq = __task_rq_lock(p); |
1da177e4 LT |
5200 | /* recheck policy now with rq lock held */ |
5201 | if (unlikely(oldpolicy != -1 && oldpolicy != p->policy)) { | |
5202 | policy = oldpolicy = -1; | |
b29739f9 IM |
5203 | __task_rq_unlock(rq); |
5204 | spin_unlock_irqrestore(&p->pi_lock, flags); | |
1da177e4 LT |
5205 | goto recheck; |
5206 | } | |
2daa3577 | 5207 | update_rq_clock(rq); |
dd41f596 | 5208 | on_rq = p->se.on_rq; |
051a1d1a | 5209 | running = task_current(rq, p); |
0e1f3483 | 5210 | if (on_rq) |
2e1cb74a | 5211 | deactivate_task(rq, p, 0); |
0e1f3483 HS |
5212 | if (running) |
5213 | p->sched_class->put_prev_task(rq, p); | |
f6b53205 | 5214 | |
1da177e4 | 5215 | oldprio = p->prio; |
dd41f596 | 5216 | __setscheduler(rq, p, policy, param->sched_priority); |
f6b53205 | 5217 | |
0e1f3483 HS |
5218 | if (running) |
5219 | p->sched_class->set_curr_task(rq); | |
dd41f596 IM |
5220 | if (on_rq) { |
5221 | activate_task(rq, p, 0); | |
cb469845 SR |
5222 | |
5223 | check_class_changed(rq, p, prev_class, oldprio, running); | |
1da177e4 | 5224 | } |
b29739f9 IM |
5225 | __task_rq_unlock(rq); |
5226 | spin_unlock_irqrestore(&p->pi_lock, flags); | |
5227 | ||
95e02ca9 TG |
5228 | rt_mutex_adjust_pi(p); |
5229 | ||
1da177e4 LT |
5230 | return 0; |
5231 | } | |
961ccddd RR |
5232 | |
5233 | /** | |
5234 | * sched_setscheduler - change the scheduling policy and/or RT priority of a thread. | |
5235 | * @p: the task in question. | |
5236 | * @policy: new policy. | |
5237 | * @param: structure containing the new RT priority. | |
5238 | * | |
5239 | * NOTE that the task may be already dead. | |
5240 | */ | |
5241 | int sched_setscheduler(struct task_struct *p, int policy, | |
5242 | struct sched_param *param) | |
5243 | { | |
5244 | return __sched_setscheduler(p, policy, param, true); | |
5245 | } | |
1da177e4 LT |
5246 | EXPORT_SYMBOL_GPL(sched_setscheduler); |
5247 | ||
961ccddd RR |
5248 | /** |
5249 | * sched_setscheduler_nocheck - change the scheduling policy and/or RT priority of a thread from kernelspace. | |
5250 | * @p: the task in question. | |
5251 | * @policy: new policy. | |
5252 | * @param: structure containing the new RT priority. | |
5253 | * | |
5254 | * Just like sched_setscheduler, only don't bother checking if the | |
5255 | * current context has permission. For example, this is needed in | |
5256 | * stop_machine(): we create temporary high priority worker threads, | |
5257 | * but our caller might not have that capability. | |
5258 | */ | |
5259 | int sched_setscheduler_nocheck(struct task_struct *p, int policy, | |
5260 | struct sched_param *param) | |
5261 | { | |
5262 | return __sched_setscheduler(p, policy, param, false); | |
5263 | } | |
5264 | ||
95cdf3b7 IM |
5265 | static int |
5266 | do_sched_setscheduler(pid_t pid, int policy, struct sched_param __user *param) | |
1da177e4 | 5267 | { |
1da177e4 LT |
5268 | struct sched_param lparam; |
5269 | struct task_struct *p; | |
36c8b586 | 5270 | int retval; |
1da177e4 LT |
5271 | |
5272 | if (!param || pid < 0) | |
5273 | return -EINVAL; | |
5274 | if (copy_from_user(&lparam, param, sizeof(struct sched_param))) | |
5275 | return -EFAULT; | |
5fe1d75f ON |
5276 | |
5277 | rcu_read_lock(); | |
5278 | retval = -ESRCH; | |
1da177e4 | 5279 | p = find_process_by_pid(pid); |
5fe1d75f ON |
5280 | if (p != NULL) |
5281 | retval = sched_setscheduler(p, policy, &lparam); | |
5282 | rcu_read_unlock(); | |
36c8b586 | 5283 | |
1da177e4 LT |
5284 | return retval; |
5285 | } | |
5286 | ||
5287 | /** | |
5288 | * sys_sched_setscheduler - set/change the scheduler policy and RT priority | |
5289 | * @pid: the pid in question. | |
5290 | * @policy: new policy. | |
5291 | * @param: structure containing the new RT priority. | |
5292 | */ | |
41a2d6cf IM |
5293 | asmlinkage long |
5294 | sys_sched_setscheduler(pid_t pid, int policy, struct sched_param __user *param) | |
1da177e4 | 5295 | { |
c21761f1 JB |
5296 | /* negative values for policy are not valid */ |
5297 | if (policy < 0) | |
5298 | return -EINVAL; | |
5299 | ||
1da177e4 LT |
5300 | return do_sched_setscheduler(pid, policy, param); |
5301 | } | |
5302 | ||
5303 | /** | |
5304 | * sys_sched_setparam - set/change the RT priority of a thread | |
5305 | * @pid: the pid in question. | |
5306 | * @param: structure containing the new RT priority. | |
5307 | */ | |
5308 | asmlinkage long sys_sched_setparam(pid_t pid, struct sched_param __user *param) | |
5309 | { | |
5310 | return do_sched_setscheduler(pid, -1, param); | |
5311 | } | |
5312 | ||
5313 | /** | |
5314 | * sys_sched_getscheduler - get the policy (scheduling class) of a thread | |
5315 | * @pid: the pid in question. | |
5316 | */ | |
5317 | asmlinkage long sys_sched_getscheduler(pid_t pid) | |
5318 | { | |
36c8b586 | 5319 | struct task_struct *p; |
3a5c359a | 5320 | int retval; |
1da177e4 LT |
5321 | |
5322 | if (pid < 0) | |
3a5c359a | 5323 | return -EINVAL; |
1da177e4 LT |
5324 | |
5325 | retval = -ESRCH; | |
5326 | read_lock(&tasklist_lock); | |
5327 | p = find_process_by_pid(pid); | |
5328 | if (p) { | |
5329 | retval = security_task_getscheduler(p); | |
5330 | if (!retval) | |
5331 | retval = p->policy; | |
5332 | } | |
5333 | read_unlock(&tasklist_lock); | |
1da177e4 LT |
5334 | return retval; |
5335 | } | |
5336 | ||
5337 | /** | |
5338 | * sys_sched_getscheduler - get the RT priority of a thread | |
5339 | * @pid: the pid in question. | |
5340 | * @param: structure containing the RT priority. | |
5341 | */ | |
5342 | asmlinkage long sys_sched_getparam(pid_t pid, struct sched_param __user *param) | |
5343 | { | |
5344 | struct sched_param lp; | |
36c8b586 | 5345 | struct task_struct *p; |
3a5c359a | 5346 | int retval; |
1da177e4 LT |
5347 | |
5348 | if (!param || pid < 0) | |
3a5c359a | 5349 | return -EINVAL; |
1da177e4 LT |
5350 | |
5351 | read_lock(&tasklist_lock); | |
5352 | p = find_process_by_pid(pid); | |
5353 | retval = -ESRCH; | |
5354 | if (!p) | |
5355 | goto out_unlock; | |
5356 | ||
5357 | retval = security_task_getscheduler(p); | |
5358 | if (retval) | |
5359 | goto out_unlock; | |
5360 | ||
5361 | lp.sched_priority = p->rt_priority; | |
5362 | read_unlock(&tasklist_lock); | |
5363 | ||
5364 | /* | |
5365 | * This one might sleep, we cannot do it with a spinlock held ... | |
5366 | */ | |
5367 | retval = copy_to_user(param, &lp, sizeof(*param)) ? -EFAULT : 0; | |
5368 | ||
1da177e4 LT |
5369 | return retval; |
5370 | ||
5371 | out_unlock: | |
5372 | read_unlock(&tasklist_lock); | |
5373 | return retval; | |
5374 | } | |
5375 | ||
b53e921b | 5376 | long sched_setaffinity(pid_t pid, const cpumask_t *in_mask) |
1da177e4 | 5377 | { |
1da177e4 | 5378 | cpumask_t cpus_allowed; |
b53e921b | 5379 | cpumask_t new_mask = *in_mask; |
36c8b586 IM |
5380 | struct task_struct *p; |
5381 | int retval; | |
1da177e4 | 5382 | |
95402b38 | 5383 | get_online_cpus(); |
1da177e4 LT |
5384 | read_lock(&tasklist_lock); |
5385 | ||
5386 | p = find_process_by_pid(pid); | |
5387 | if (!p) { | |
5388 | read_unlock(&tasklist_lock); | |
95402b38 | 5389 | put_online_cpus(); |
1da177e4 LT |
5390 | return -ESRCH; |
5391 | } | |
5392 | ||
5393 | /* | |
5394 | * It is not safe to call set_cpus_allowed with the | |
41a2d6cf | 5395 | * tasklist_lock held. We will bump the task_struct's |
1da177e4 LT |
5396 | * usage count and then drop tasklist_lock. |
5397 | */ | |
5398 | get_task_struct(p); | |
5399 | read_unlock(&tasklist_lock); | |
5400 | ||
5401 | retval = -EPERM; | |
5402 | if ((current->euid != p->euid) && (current->euid != p->uid) && | |
5403 | !capable(CAP_SYS_NICE)) | |
5404 | goto out_unlock; | |
5405 | ||
e7834f8f DQ |
5406 | retval = security_task_setscheduler(p, 0, NULL); |
5407 | if (retval) | |
5408 | goto out_unlock; | |
5409 | ||
f9a86fcb | 5410 | cpuset_cpus_allowed(p, &cpus_allowed); |
1da177e4 | 5411 | cpus_and(new_mask, new_mask, cpus_allowed); |
8707d8b8 | 5412 | again: |
7c16ec58 | 5413 | retval = set_cpus_allowed_ptr(p, &new_mask); |
1da177e4 | 5414 | |
8707d8b8 | 5415 | if (!retval) { |
f9a86fcb | 5416 | cpuset_cpus_allowed(p, &cpus_allowed); |
8707d8b8 PM |
5417 | if (!cpus_subset(new_mask, cpus_allowed)) { |
5418 | /* | |
5419 | * We must have raced with a concurrent cpuset | |
5420 | * update. Just reset the cpus_allowed to the | |
5421 | * cpuset's cpus_allowed | |
5422 | */ | |
5423 | new_mask = cpus_allowed; | |
5424 | goto again; | |
5425 | } | |
5426 | } | |
1da177e4 LT |
5427 | out_unlock: |
5428 | put_task_struct(p); | |
95402b38 | 5429 | put_online_cpus(); |
1da177e4 LT |
5430 | return retval; |
5431 | } | |
5432 | ||
5433 | static int get_user_cpu_mask(unsigned long __user *user_mask_ptr, unsigned len, | |
5434 | cpumask_t *new_mask) | |
5435 | { | |
5436 | if (len < sizeof(cpumask_t)) { | |
5437 | memset(new_mask, 0, sizeof(cpumask_t)); | |
5438 | } else if (len > sizeof(cpumask_t)) { | |
5439 | len = sizeof(cpumask_t); | |
5440 | } | |
5441 | return copy_from_user(new_mask, user_mask_ptr, len) ? -EFAULT : 0; | |
5442 | } | |
5443 | ||
5444 | /** | |
5445 | * sys_sched_setaffinity - set the cpu affinity of a process | |
5446 | * @pid: pid of the process | |
5447 | * @len: length in bytes of the bitmask pointed to by user_mask_ptr | |
5448 | * @user_mask_ptr: user-space pointer to the new cpu mask | |
5449 | */ | |
5450 | asmlinkage long sys_sched_setaffinity(pid_t pid, unsigned int len, | |
5451 | unsigned long __user *user_mask_ptr) | |
5452 | { | |
5453 | cpumask_t new_mask; | |
5454 | int retval; | |
5455 | ||
5456 | retval = get_user_cpu_mask(user_mask_ptr, len, &new_mask); | |
5457 | if (retval) | |
5458 | return retval; | |
5459 | ||
b53e921b | 5460 | return sched_setaffinity(pid, &new_mask); |
1da177e4 LT |
5461 | } |
5462 | ||
1da177e4 LT |
5463 | long sched_getaffinity(pid_t pid, cpumask_t *mask) |
5464 | { | |
36c8b586 | 5465 | struct task_struct *p; |
1da177e4 | 5466 | int retval; |
1da177e4 | 5467 | |
95402b38 | 5468 | get_online_cpus(); |
1da177e4 LT |
5469 | read_lock(&tasklist_lock); |
5470 | ||
5471 | retval = -ESRCH; | |
5472 | p = find_process_by_pid(pid); | |
5473 | if (!p) | |
5474 | goto out_unlock; | |
5475 | ||
e7834f8f DQ |
5476 | retval = security_task_getscheduler(p); |
5477 | if (retval) | |
5478 | goto out_unlock; | |
5479 | ||
2f7016d9 | 5480 | cpus_and(*mask, p->cpus_allowed, cpu_online_map); |
1da177e4 LT |
5481 | |
5482 | out_unlock: | |
5483 | read_unlock(&tasklist_lock); | |
95402b38 | 5484 | put_online_cpus(); |
1da177e4 | 5485 | |
9531b62f | 5486 | return retval; |
1da177e4 LT |
5487 | } |
5488 | ||
5489 | /** | |
5490 | * sys_sched_getaffinity - get the cpu affinity of a process | |
5491 | * @pid: pid of the process | |
5492 | * @len: length in bytes of the bitmask pointed to by user_mask_ptr | |
5493 | * @user_mask_ptr: user-space pointer to hold the current cpu mask | |
5494 | */ | |
5495 | asmlinkage long sys_sched_getaffinity(pid_t pid, unsigned int len, | |
5496 | unsigned long __user *user_mask_ptr) | |
5497 | { | |
5498 | int ret; | |
5499 | cpumask_t mask; | |
5500 | ||
5501 | if (len < sizeof(cpumask_t)) | |
5502 | return -EINVAL; | |
5503 | ||
5504 | ret = sched_getaffinity(pid, &mask); | |
5505 | if (ret < 0) | |
5506 | return ret; | |
5507 | ||
5508 | if (copy_to_user(user_mask_ptr, &mask, sizeof(cpumask_t))) | |
5509 | return -EFAULT; | |
5510 | ||
5511 | return sizeof(cpumask_t); | |
5512 | } | |
5513 | ||
5514 | /** | |
5515 | * sys_sched_yield - yield the current processor to other threads. | |
5516 | * | |
dd41f596 IM |
5517 | * This function yields the current CPU to other tasks. If there are no |
5518 | * other threads running on this CPU then this function will return. | |
1da177e4 LT |
5519 | */ |
5520 | asmlinkage long sys_sched_yield(void) | |
5521 | { | |
70b97a7f | 5522 | struct rq *rq = this_rq_lock(); |
1da177e4 | 5523 | |
2d72376b | 5524 | schedstat_inc(rq, yld_count); |
4530d7ab | 5525 | current->sched_class->yield_task(rq); |
1da177e4 LT |
5526 | |
5527 | /* | |
5528 | * Since we are going to call schedule() anyway, there's | |
5529 | * no need to preempt or enable interrupts: | |
5530 | */ | |
5531 | __release(rq->lock); | |
8a25d5de | 5532 | spin_release(&rq->lock.dep_map, 1, _THIS_IP_); |
1da177e4 LT |
5533 | _raw_spin_unlock(&rq->lock); |
5534 | preempt_enable_no_resched(); | |
5535 | ||
5536 | schedule(); | |
5537 | ||
5538 | return 0; | |
5539 | } | |
5540 | ||
e7b38404 | 5541 | static void __cond_resched(void) |
1da177e4 | 5542 | { |
8e0a43d8 IM |
5543 | #ifdef CONFIG_DEBUG_SPINLOCK_SLEEP |
5544 | __might_sleep(__FILE__, __LINE__); | |
5545 | #endif | |
5bbcfd90 IM |
5546 | /* |
5547 | * The BKS might be reacquired before we have dropped | |
5548 | * PREEMPT_ACTIVE, which could trigger a second | |
5549 | * cond_resched() call. | |
5550 | */ | |
1da177e4 LT |
5551 | do { |
5552 | add_preempt_count(PREEMPT_ACTIVE); | |
5553 | schedule(); | |
5554 | sub_preempt_count(PREEMPT_ACTIVE); | |
5555 | } while (need_resched()); | |
5556 | } | |
5557 | ||
02b67cc3 | 5558 | int __sched _cond_resched(void) |
1da177e4 | 5559 | { |
9414232f IM |
5560 | if (need_resched() && !(preempt_count() & PREEMPT_ACTIVE) && |
5561 | system_state == SYSTEM_RUNNING) { | |
1da177e4 LT |
5562 | __cond_resched(); |
5563 | return 1; | |
5564 | } | |
5565 | return 0; | |
5566 | } | |
02b67cc3 | 5567 | EXPORT_SYMBOL(_cond_resched); |
1da177e4 LT |
5568 | |
5569 | /* | |
5570 | * cond_resched_lock() - if a reschedule is pending, drop the given lock, | |
5571 | * call schedule, and on return reacquire the lock. | |
5572 | * | |
41a2d6cf | 5573 | * This works OK both with and without CONFIG_PREEMPT. We do strange low-level |
1da177e4 LT |
5574 | * operations here to prevent schedule() from being called twice (once via |
5575 | * spin_unlock(), once by hand). | |
5576 | */ | |
95cdf3b7 | 5577 | int cond_resched_lock(spinlock_t *lock) |
1da177e4 | 5578 | { |
95c354fe | 5579 | int resched = need_resched() && system_state == SYSTEM_RUNNING; |
6df3cecb JK |
5580 | int ret = 0; |
5581 | ||
95c354fe | 5582 | if (spin_needbreak(lock) || resched) { |
1da177e4 | 5583 | spin_unlock(lock); |
95c354fe NP |
5584 | if (resched && need_resched()) |
5585 | __cond_resched(); | |
5586 | else | |
5587 | cpu_relax(); | |
6df3cecb | 5588 | ret = 1; |
1da177e4 | 5589 | spin_lock(lock); |
1da177e4 | 5590 | } |
6df3cecb | 5591 | return ret; |
1da177e4 | 5592 | } |
1da177e4 LT |
5593 | EXPORT_SYMBOL(cond_resched_lock); |
5594 | ||
5595 | int __sched cond_resched_softirq(void) | |
5596 | { | |
5597 | BUG_ON(!in_softirq()); | |
5598 | ||
9414232f | 5599 | if (need_resched() && system_state == SYSTEM_RUNNING) { |
98d82567 | 5600 | local_bh_enable(); |
1da177e4 LT |
5601 | __cond_resched(); |
5602 | local_bh_disable(); | |
5603 | return 1; | |
5604 | } | |
5605 | return 0; | |
5606 | } | |
1da177e4 LT |
5607 | EXPORT_SYMBOL(cond_resched_softirq); |
5608 | ||
1da177e4 LT |
5609 | /** |
5610 | * yield - yield the current processor to other threads. | |
5611 | * | |
72fd4a35 | 5612 | * This is a shortcut for kernel-space yielding - it marks the |
1da177e4 LT |
5613 | * thread runnable and calls sys_sched_yield(). |
5614 | */ | |
5615 | void __sched yield(void) | |
5616 | { | |
5617 | set_current_state(TASK_RUNNING); | |
5618 | sys_sched_yield(); | |
5619 | } | |
1da177e4 LT |
5620 | EXPORT_SYMBOL(yield); |
5621 | ||
5622 | /* | |
41a2d6cf | 5623 | * This task is about to go to sleep on IO. Increment rq->nr_iowait so |
1da177e4 LT |
5624 | * that process accounting knows that this is a task in IO wait state. |
5625 | * | |
5626 | * But don't do that if it is a deliberate, throttling IO wait (this task | |
5627 | * has set its backing_dev_info: the queue against which it should throttle) | |
5628 | */ | |
5629 | void __sched io_schedule(void) | |
5630 | { | |
70b97a7f | 5631 | struct rq *rq = &__raw_get_cpu_var(runqueues); |
1da177e4 | 5632 | |
0ff92245 | 5633 | delayacct_blkio_start(); |
1da177e4 LT |
5634 | atomic_inc(&rq->nr_iowait); |
5635 | schedule(); | |
5636 | atomic_dec(&rq->nr_iowait); | |
0ff92245 | 5637 | delayacct_blkio_end(); |
1da177e4 | 5638 | } |
1da177e4 LT |
5639 | EXPORT_SYMBOL(io_schedule); |
5640 | ||
5641 | long __sched io_schedule_timeout(long timeout) | |
5642 | { | |
70b97a7f | 5643 | struct rq *rq = &__raw_get_cpu_var(runqueues); |
1da177e4 LT |
5644 | long ret; |
5645 | ||
0ff92245 | 5646 | delayacct_blkio_start(); |
1da177e4 LT |
5647 | atomic_inc(&rq->nr_iowait); |
5648 | ret = schedule_timeout(timeout); | |
5649 | atomic_dec(&rq->nr_iowait); | |
0ff92245 | 5650 | delayacct_blkio_end(); |
1da177e4 LT |
5651 | return ret; |
5652 | } | |
5653 | ||
5654 | /** | |
5655 | * sys_sched_get_priority_max - return maximum RT priority. | |
5656 | * @policy: scheduling class. | |
5657 | * | |
5658 | * this syscall returns the maximum rt_priority that can be used | |
5659 | * by a given scheduling class. | |
5660 | */ | |
5661 | asmlinkage long sys_sched_get_priority_max(int policy) | |
5662 | { | |
5663 | int ret = -EINVAL; | |
5664 | ||
5665 | switch (policy) { | |
5666 | case SCHED_FIFO: | |
5667 | case SCHED_RR: | |
5668 | ret = MAX_USER_RT_PRIO-1; | |
5669 | break; | |
5670 | case SCHED_NORMAL: | |
b0a9499c | 5671 | case SCHED_BATCH: |
dd41f596 | 5672 | case SCHED_IDLE: |
1da177e4 LT |
5673 | ret = 0; |
5674 | break; | |
5675 | } | |
5676 | return ret; | |
5677 | } | |
5678 | ||
5679 | /** | |
5680 | * sys_sched_get_priority_min - return minimum RT priority. | |
5681 | * @policy: scheduling class. | |
5682 | * | |
5683 | * this syscall returns the minimum rt_priority that can be used | |
5684 | * by a given scheduling class. | |
5685 | */ | |
5686 | asmlinkage long sys_sched_get_priority_min(int policy) | |
5687 | { | |
5688 | int ret = -EINVAL; | |
5689 | ||
5690 | switch (policy) { | |
5691 | case SCHED_FIFO: | |
5692 | case SCHED_RR: | |
5693 | ret = 1; | |
5694 | break; | |
5695 | case SCHED_NORMAL: | |
b0a9499c | 5696 | case SCHED_BATCH: |
dd41f596 | 5697 | case SCHED_IDLE: |
1da177e4 LT |
5698 | ret = 0; |
5699 | } | |
5700 | return ret; | |
5701 | } | |
5702 | ||
5703 | /** | |
5704 | * sys_sched_rr_get_interval - return the default timeslice of a process. | |
5705 | * @pid: pid of the process. | |
5706 | * @interval: userspace pointer to the timeslice value. | |
5707 | * | |
5708 | * this syscall writes the default timeslice value of a given process | |
5709 | * into the user-space timespec buffer. A value of '0' means infinity. | |
5710 | */ | |
5711 | asmlinkage | |
5712 | long sys_sched_rr_get_interval(pid_t pid, struct timespec __user *interval) | |
5713 | { | |
36c8b586 | 5714 | struct task_struct *p; |
a4ec24b4 | 5715 | unsigned int time_slice; |
3a5c359a | 5716 | int retval; |
1da177e4 | 5717 | struct timespec t; |
1da177e4 LT |
5718 | |
5719 | if (pid < 0) | |
3a5c359a | 5720 | return -EINVAL; |
1da177e4 LT |
5721 | |
5722 | retval = -ESRCH; | |
5723 | read_lock(&tasklist_lock); | |
5724 | p = find_process_by_pid(pid); | |
5725 | if (!p) | |
5726 | goto out_unlock; | |
5727 | ||
5728 | retval = security_task_getscheduler(p); | |
5729 | if (retval) | |
5730 | goto out_unlock; | |
5731 | ||
77034937 IM |
5732 | /* |
5733 | * Time slice is 0 for SCHED_FIFO tasks and for SCHED_OTHER | |
5734 | * tasks that are on an otherwise idle runqueue: | |
5735 | */ | |
5736 | time_slice = 0; | |
5737 | if (p->policy == SCHED_RR) { | |
a4ec24b4 | 5738 | time_slice = DEF_TIMESLICE; |
1868f958 | 5739 | } else if (p->policy != SCHED_FIFO) { |
a4ec24b4 DA |
5740 | struct sched_entity *se = &p->se; |
5741 | unsigned long flags; | |
5742 | struct rq *rq; | |
5743 | ||
5744 | rq = task_rq_lock(p, &flags); | |
77034937 IM |
5745 | if (rq->cfs.load.weight) |
5746 | time_slice = NS_TO_JIFFIES(sched_slice(&rq->cfs, se)); | |
a4ec24b4 DA |
5747 | task_rq_unlock(rq, &flags); |
5748 | } | |
1da177e4 | 5749 | read_unlock(&tasklist_lock); |
a4ec24b4 | 5750 | jiffies_to_timespec(time_slice, &t); |
1da177e4 | 5751 | retval = copy_to_user(interval, &t, sizeof(t)) ? -EFAULT : 0; |
1da177e4 | 5752 | return retval; |
3a5c359a | 5753 | |
1da177e4 LT |
5754 | out_unlock: |
5755 | read_unlock(&tasklist_lock); | |
5756 | return retval; | |
5757 | } | |
5758 | ||
7c731e0a | 5759 | static const char stat_nam[] = TASK_STATE_TO_CHAR_STR; |
36c8b586 | 5760 | |
82a1fcb9 | 5761 | void sched_show_task(struct task_struct *p) |
1da177e4 | 5762 | { |
1da177e4 | 5763 | unsigned long free = 0; |
36c8b586 | 5764 | unsigned state; |
1da177e4 | 5765 | |
1da177e4 | 5766 | state = p->state ? __ffs(p->state) + 1 : 0; |
cc4ea795 | 5767 | printk(KERN_INFO "%-13.13s %c", p->comm, |
2ed6e34f | 5768 | state < sizeof(stat_nam) - 1 ? stat_nam[state] : '?'); |
4bd77321 | 5769 | #if BITS_PER_LONG == 32 |
1da177e4 | 5770 | if (state == TASK_RUNNING) |
cc4ea795 | 5771 | printk(KERN_CONT " running "); |
1da177e4 | 5772 | else |
cc4ea795 | 5773 | printk(KERN_CONT " %08lx ", thread_saved_pc(p)); |
1da177e4 LT |
5774 | #else |
5775 | if (state == TASK_RUNNING) | |
cc4ea795 | 5776 | printk(KERN_CONT " running task "); |
1da177e4 | 5777 | else |
cc4ea795 | 5778 | printk(KERN_CONT " %016lx ", thread_saved_pc(p)); |
1da177e4 LT |
5779 | #endif |
5780 | #ifdef CONFIG_DEBUG_STACK_USAGE | |
5781 | { | |
10ebffde | 5782 | unsigned long *n = end_of_stack(p); |
1da177e4 LT |
5783 | while (!*n) |
5784 | n++; | |
10ebffde | 5785 | free = (unsigned long)n - (unsigned long)end_of_stack(p); |
1da177e4 LT |
5786 | } |
5787 | #endif | |
ba25f9dc | 5788 | printk(KERN_CONT "%5lu %5d %6d\n", free, |
fcfd50af | 5789 | task_pid_nr(p), task_pid_nr(p->real_parent)); |
1da177e4 | 5790 | |
5fb5e6de | 5791 | show_stack(p, NULL); |
1da177e4 LT |
5792 | } |
5793 | ||
e59e2ae2 | 5794 | void show_state_filter(unsigned long state_filter) |
1da177e4 | 5795 | { |
36c8b586 | 5796 | struct task_struct *g, *p; |
1da177e4 | 5797 | |
4bd77321 IM |
5798 | #if BITS_PER_LONG == 32 |
5799 | printk(KERN_INFO | |
5800 | " task PC stack pid father\n"); | |
1da177e4 | 5801 | #else |
4bd77321 IM |
5802 | printk(KERN_INFO |
5803 | " task PC stack pid father\n"); | |
1da177e4 LT |
5804 | #endif |
5805 | read_lock(&tasklist_lock); | |
5806 | do_each_thread(g, p) { | |
5807 | /* | |
5808 | * reset the NMI-timeout, listing all files on a slow | |
5809 | * console might take alot of time: | |
5810 | */ | |
5811 | touch_nmi_watchdog(); | |
39bc89fd | 5812 | if (!state_filter || (p->state & state_filter)) |
82a1fcb9 | 5813 | sched_show_task(p); |
1da177e4 LT |
5814 | } while_each_thread(g, p); |
5815 | ||
04c9167f JF |
5816 | touch_all_softlockup_watchdogs(); |
5817 | ||
dd41f596 IM |
5818 | #ifdef CONFIG_SCHED_DEBUG |
5819 | sysrq_sched_debug_show(); | |
5820 | #endif | |
1da177e4 | 5821 | read_unlock(&tasklist_lock); |
e59e2ae2 IM |
5822 | /* |
5823 | * Only show locks if all tasks are dumped: | |
5824 | */ | |
5825 | if (state_filter == -1) | |
5826 | debug_show_all_locks(); | |
1da177e4 LT |
5827 | } |
5828 | ||
1df21055 IM |
5829 | void __cpuinit init_idle_bootup_task(struct task_struct *idle) |
5830 | { | |
dd41f596 | 5831 | idle->sched_class = &idle_sched_class; |
1df21055 IM |
5832 | } |
5833 | ||
f340c0d1 IM |
5834 | /** |
5835 | * init_idle - set up an idle thread for a given CPU | |
5836 | * @idle: task in question | |
5837 | * @cpu: cpu the idle task belongs to | |
5838 | * | |
5839 | * NOTE: this function does not set the idle thread's NEED_RESCHED | |
5840 | * flag, to make booting more robust. | |
5841 | */ | |
5c1e1767 | 5842 | void __cpuinit init_idle(struct task_struct *idle, int cpu) |
1da177e4 | 5843 | { |
70b97a7f | 5844 | struct rq *rq = cpu_rq(cpu); |
1da177e4 LT |
5845 | unsigned long flags; |
5846 | ||
5cbd54ef IM |
5847 | spin_lock_irqsave(&rq->lock, flags); |
5848 | ||
dd41f596 IM |
5849 | __sched_fork(idle); |
5850 | idle->se.exec_start = sched_clock(); | |
5851 | ||
b29739f9 | 5852 | idle->prio = idle->normal_prio = MAX_PRIO; |
1da177e4 | 5853 | idle->cpus_allowed = cpumask_of_cpu(cpu); |
dd41f596 | 5854 | __set_task_cpu(idle, cpu); |
1da177e4 | 5855 | |
1da177e4 | 5856 | rq->curr = rq->idle = idle; |
4866cde0 NP |
5857 | #if defined(CONFIG_SMP) && defined(__ARCH_WANT_UNLOCKED_CTXSW) |
5858 | idle->oncpu = 1; | |
5859 | #endif | |
1da177e4 LT |
5860 | spin_unlock_irqrestore(&rq->lock, flags); |
5861 | ||
5862 | /* Set the preempt count _outside_ the spinlocks! */ | |
8e3e076c LT |
5863 | #if defined(CONFIG_PREEMPT) |
5864 | task_thread_info(idle)->preempt_count = (idle->lock_depth >= 0); | |
5865 | #else | |
a1261f54 | 5866 | task_thread_info(idle)->preempt_count = 0; |
8e3e076c | 5867 | #endif |
dd41f596 IM |
5868 | /* |
5869 | * The idle tasks have their own, simple scheduling class: | |
5870 | */ | |
5871 | idle->sched_class = &idle_sched_class; | |
f201ae23 | 5872 | ftrace_retfunc_init_task(idle); |
1da177e4 LT |
5873 | } |
5874 | ||
5875 | /* | |
5876 | * In a system that switches off the HZ timer nohz_cpu_mask | |
5877 | * indicates which cpus entered this state. This is used | |
5878 | * in the rcu update to wait only for active cpus. For system | |
5879 | * which do not switch off the HZ timer nohz_cpu_mask should | |
5880 | * always be CPU_MASK_NONE. | |
5881 | */ | |
5882 | cpumask_t nohz_cpu_mask = CPU_MASK_NONE; | |
5883 | ||
19978ca6 IM |
5884 | /* |
5885 | * Increase the granularity value when there are more CPUs, | |
5886 | * because with more CPUs the 'effective latency' as visible | |
5887 | * to users decreases. But the relationship is not linear, | |
5888 | * so pick a second-best guess by going with the log2 of the | |
5889 | * number of CPUs. | |
5890 | * | |
5891 | * This idea comes from the SD scheduler of Con Kolivas: | |
5892 | */ | |
5893 | static inline void sched_init_granularity(void) | |
5894 | { | |
5895 | unsigned int factor = 1 + ilog2(num_online_cpus()); | |
5896 | const unsigned long limit = 200000000; | |
5897 | ||
5898 | sysctl_sched_min_granularity *= factor; | |
5899 | if (sysctl_sched_min_granularity > limit) | |
5900 | sysctl_sched_min_granularity = limit; | |
5901 | ||
5902 | sysctl_sched_latency *= factor; | |
5903 | if (sysctl_sched_latency > limit) | |
5904 | sysctl_sched_latency = limit; | |
5905 | ||
5906 | sysctl_sched_wakeup_granularity *= factor; | |
55cd5340 PZ |
5907 | |
5908 | sysctl_sched_shares_ratelimit *= factor; | |
19978ca6 IM |
5909 | } |
5910 | ||
1da177e4 LT |
5911 | #ifdef CONFIG_SMP |
5912 | /* | |
5913 | * This is how migration works: | |
5914 | * | |
70b97a7f | 5915 | * 1) we queue a struct migration_req structure in the source CPU's |
1da177e4 LT |
5916 | * runqueue and wake up that CPU's migration thread. |
5917 | * 2) we down() the locked semaphore => thread blocks. | |
5918 | * 3) migration thread wakes up (implicitly it forces the migrated | |
5919 | * thread off the CPU) | |
5920 | * 4) it gets the migration request and checks whether the migrated | |
5921 | * task is still in the wrong runqueue. | |
5922 | * 5) if it's in the wrong runqueue then the migration thread removes | |
5923 | * it and puts it into the right queue. | |
5924 | * 6) migration thread up()s the semaphore. | |
5925 | * 7) we wake up and the migration is done. | |
5926 | */ | |
5927 | ||
5928 | /* | |
5929 | * Change a given task's CPU affinity. Migrate the thread to a | |
5930 | * proper CPU and schedule it away if the CPU it's executing on | |
5931 | * is removed from the allowed bitmask. | |
5932 | * | |
5933 | * NOTE: the caller must have a valid reference to the task, the | |
41a2d6cf | 5934 | * task must not exit() & deallocate itself prematurely. The |
1da177e4 LT |
5935 | * call is not atomic; no spinlocks may be held. |
5936 | */ | |
cd8ba7cd | 5937 | int set_cpus_allowed_ptr(struct task_struct *p, const cpumask_t *new_mask) |
1da177e4 | 5938 | { |
70b97a7f | 5939 | struct migration_req req; |
1da177e4 | 5940 | unsigned long flags; |
70b97a7f | 5941 | struct rq *rq; |
48f24c4d | 5942 | int ret = 0; |
1da177e4 LT |
5943 | |
5944 | rq = task_rq_lock(p, &flags); | |
cd8ba7cd | 5945 | if (!cpus_intersects(*new_mask, cpu_online_map)) { |
1da177e4 LT |
5946 | ret = -EINVAL; |
5947 | goto out; | |
5948 | } | |
5949 | ||
9985b0ba DR |
5950 | if (unlikely((p->flags & PF_THREAD_BOUND) && p != current && |
5951 | !cpus_equal(p->cpus_allowed, *new_mask))) { | |
5952 | ret = -EINVAL; | |
5953 | goto out; | |
5954 | } | |
5955 | ||
73fe6aae | 5956 | if (p->sched_class->set_cpus_allowed) |
cd8ba7cd | 5957 | p->sched_class->set_cpus_allowed(p, new_mask); |
73fe6aae | 5958 | else { |
cd8ba7cd MT |
5959 | p->cpus_allowed = *new_mask; |
5960 | p->rt.nr_cpus_allowed = cpus_weight(*new_mask); | |
73fe6aae GH |
5961 | } |
5962 | ||
1da177e4 | 5963 | /* Can the task run on the task's current CPU? If so, we're done */ |
cd8ba7cd | 5964 | if (cpu_isset(task_cpu(p), *new_mask)) |
1da177e4 LT |
5965 | goto out; |
5966 | ||
cd8ba7cd | 5967 | if (migrate_task(p, any_online_cpu(*new_mask), &req)) { |
1da177e4 LT |
5968 | /* Need help from migration thread: drop lock and wait. */ |
5969 | task_rq_unlock(rq, &flags); | |
5970 | wake_up_process(rq->migration_thread); | |
5971 | wait_for_completion(&req.done); | |
5972 | tlb_migrate_finish(p->mm); | |
5973 | return 0; | |
5974 | } | |
5975 | out: | |
5976 | task_rq_unlock(rq, &flags); | |
48f24c4d | 5977 | |
1da177e4 LT |
5978 | return ret; |
5979 | } | |
cd8ba7cd | 5980 | EXPORT_SYMBOL_GPL(set_cpus_allowed_ptr); |
1da177e4 LT |
5981 | |
5982 | /* | |
41a2d6cf | 5983 | * Move (not current) task off this cpu, onto dest cpu. We're doing |
1da177e4 LT |
5984 | * this because either it can't run here any more (set_cpus_allowed() |
5985 | * away from this CPU, or CPU going down), or because we're | |
5986 | * attempting to rebalance this task on exec (sched_exec). | |
5987 | * | |
5988 | * So we race with normal scheduler movements, but that's OK, as long | |
5989 | * as the task is no longer on this CPU. | |
efc30814 KK |
5990 | * |
5991 | * Returns non-zero if task was successfully migrated. | |
1da177e4 | 5992 | */ |
efc30814 | 5993 | static int __migrate_task(struct task_struct *p, int src_cpu, int dest_cpu) |
1da177e4 | 5994 | { |
70b97a7f | 5995 | struct rq *rq_dest, *rq_src; |
dd41f596 | 5996 | int ret = 0, on_rq; |
1da177e4 | 5997 | |
e761b772 | 5998 | if (unlikely(!cpu_active(dest_cpu))) |
efc30814 | 5999 | return ret; |
1da177e4 LT |
6000 | |
6001 | rq_src = cpu_rq(src_cpu); | |
6002 | rq_dest = cpu_rq(dest_cpu); | |
6003 | ||
6004 | double_rq_lock(rq_src, rq_dest); | |
6005 | /* Already moved. */ | |
6006 | if (task_cpu(p) != src_cpu) | |
b1e38734 | 6007 | goto done; |
1da177e4 LT |
6008 | /* Affinity changed (again). */ |
6009 | if (!cpu_isset(dest_cpu, p->cpus_allowed)) | |
b1e38734 | 6010 | goto fail; |
1da177e4 | 6011 | |
dd41f596 | 6012 | on_rq = p->se.on_rq; |
6e82a3be | 6013 | if (on_rq) |
2e1cb74a | 6014 | deactivate_task(rq_src, p, 0); |
6e82a3be | 6015 | |
1da177e4 | 6016 | set_task_cpu(p, dest_cpu); |
dd41f596 IM |
6017 | if (on_rq) { |
6018 | activate_task(rq_dest, p, 0); | |
15afe09b | 6019 | check_preempt_curr(rq_dest, p, 0); |
1da177e4 | 6020 | } |
b1e38734 | 6021 | done: |
efc30814 | 6022 | ret = 1; |
b1e38734 | 6023 | fail: |
1da177e4 | 6024 | double_rq_unlock(rq_src, rq_dest); |
efc30814 | 6025 | return ret; |
1da177e4 LT |
6026 | } |
6027 | ||
6028 | /* | |
6029 | * migration_thread - this is a highprio system thread that performs | |
6030 | * thread migration by bumping thread off CPU then 'pushing' onto | |
6031 | * another runqueue. | |
6032 | */ | |
95cdf3b7 | 6033 | static int migration_thread(void *data) |
1da177e4 | 6034 | { |
1da177e4 | 6035 | int cpu = (long)data; |
70b97a7f | 6036 | struct rq *rq; |
1da177e4 LT |
6037 | |
6038 | rq = cpu_rq(cpu); | |
6039 | BUG_ON(rq->migration_thread != current); | |
6040 | ||
6041 | set_current_state(TASK_INTERRUPTIBLE); | |
6042 | while (!kthread_should_stop()) { | |
70b97a7f | 6043 | struct migration_req *req; |
1da177e4 | 6044 | struct list_head *head; |
1da177e4 | 6045 | |
1da177e4 LT |
6046 | spin_lock_irq(&rq->lock); |
6047 | ||
6048 | if (cpu_is_offline(cpu)) { | |
6049 | spin_unlock_irq(&rq->lock); | |
6050 | goto wait_to_die; | |
6051 | } | |
6052 | ||
6053 | if (rq->active_balance) { | |
6054 | active_load_balance(rq, cpu); | |
6055 | rq->active_balance = 0; | |
6056 | } | |
6057 | ||
6058 | head = &rq->migration_queue; | |
6059 | ||
6060 | if (list_empty(head)) { | |
6061 | spin_unlock_irq(&rq->lock); | |
6062 | schedule(); | |
6063 | set_current_state(TASK_INTERRUPTIBLE); | |
6064 | continue; | |
6065 | } | |
70b97a7f | 6066 | req = list_entry(head->next, struct migration_req, list); |
1da177e4 LT |
6067 | list_del_init(head->next); |
6068 | ||
674311d5 NP |
6069 | spin_unlock(&rq->lock); |
6070 | __migrate_task(req->task, cpu, req->dest_cpu); | |
6071 | local_irq_enable(); | |
1da177e4 LT |
6072 | |
6073 | complete(&req->done); | |
6074 | } | |
6075 | __set_current_state(TASK_RUNNING); | |
6076 | return 0; | |
6077 | ||
6078 | wait_to_die: | |
6079 | /* Wait for kthread_stop */ | |
6080 | set_current_state(TASK_INTERRUPTIBLE); | |
6081 | while (!kthread_should_stop()) { | |
6082 | schedule(); | |
6083 | set_current_state(TASK_INTERRUPTIBLE); | |
6084 | } | |
6085 | __set_current_state(TASK_RUNNING); | |
6086 | return 0; | |
6087 | } | |
6088 | ||
6089 | #ifdef CONFIG_HOTPLUG_CPU | |
f7b4cddc ON |
6090 | |
6091 | static int __migrate_task_irq(struct task_struct *p, int src_cpu, int dest_cpu) | |
6092 | { | |
6093 | int ret; | |
6094 | ||
6095 | local_irq_disable(); | |
6096 | ret = __migrate_task(p, src_cpu, dest_cpu); | |
6097 | local_irq_enable(); | |
6098 | return ret; | |
6099 | } | |
6100 | ||
054b9108 | 6101 | /* |
3a4fa0a2 | 6102 | * Figure out where task on dead CPU should go, use force if necessary. |
054b9108 | 6103 | */ |
48f24c4d | 6104 | static void move_task_off_dead_cpu(int dead_cpu, struct task_struct *p) |
1da177e4 | 6105 | { |
efc30814 | 6106 | unsigned long flags; |
1da177e4 | 6107 | cpumask_t mask; |
70b97a7f IM |
6108 | struct rq *rq; |
6109 | int dest_cpu; | |
1da177e4 | 6110 | |
3a5c359a AK |
6111 | do { |
6112 | /* On same node? */ | |
ea6f18ed MT |
6113 | node_to_cpumask_ptr(pnodemask, cpu_to_node(dead_cpu)); |
6114 | ||
6115 | cpus_and(mask, *pnodemask, p->cpus_allowed); | |
3a5c359a AK |
6116 | dest_cpu = any_online_cpu(mask); |
6117 | ||
6118 | /* On any allowed CPU? */ | |
434d53b0 | 6119 | if (dest_cpu >= nr_cpu_ids) |
3a5c359a AK |
6120 | dest_cpu = any_online_cpu(p->cpus_allowed); |
6121 | ||
6122 | /* No more Mr. Nice Guy. */ | |
434d53b0 | 6123 | if (dest_cpu >= nr_cpu_ids) { |
f9a86fcb MT |
6124 | cpumask_t cpus_allowed; |
6125 | ||
6126 | cpuset_cpus_allowed_locked(p, &cpus_allowed); | |
470fd646 CW |
6127 | /* |
6128 | * Try to stay on the same cpuset, where the | |
6129 | * current cpuset may be a subset of all cpus. | |
6130 | * The cpuset_cpus_allowed_locked() variant of | |
41a2d6cf | 6131 | * cpuset_cpus_allowed() will not block. It must be |
470fd646 CW |
6132 | * called within calls to cpuset_lock/cpuset_unlock. |
6133 | */ | |
3a5c359a | 6134 | rq = task_rq_lock(p, &flags); |
470fd646 | 6135 | p->cpus_allowed = cpus_allowed; |
3a5c359a AK |
6136 | dest_cpu = any_online_cpu(p->cpus_allowed); |
6137 | task_rq_unlock(rq, &flags); | |
1da177e4 | 6138 | |
3a5c359a AK |
6139 | /* |
6140 | * Don't tell them about moving exiting tasks or | |
6141 | * kernel threads (both mm NULL), since they never | |
6142 | * leave kernel. | |
6143 | */ | |
41a2d6cf | 6144 | if (p->mm && printk_ratelimit()) { |
3a5c359a AK |
6145 | printk(KERN_INFO "process %d (%s) no " |
6146 | "longer affine to cpu%d\n", | |
41a2d6cf IM |
6147 | task_pid_nr(p), p->comm, dead_cpu); |
6148 | } | |
3a5c359a | 6149 | } |
f7b4cddc | 6150 | } while (!__migrate_task_irq(p, dead_cpu, dest_cpu)); |
1da177e4 LT |
6151 | } |
6152 | ||
6153 | /* | |
6154 | * While a dead CPU has no uninterruptible tasks queued at this point, | |
6155 | * it might still have a nonzero ->nr_uninterruptible counter, because | |
6156 | * for performance reasons the counter is not stricly tracking tasks to | |
6157 | * their home CPUs. So we just add the counter to another CPU's counter, | |
6158 | * to keep the global sum constant after CPU-down: | |
6159 | */ | |
70b97a7f | 6160 | static void migrate_nr_uninterruptible(struct rq *rq_src) |
1da177e4 | 6161 | { |
7c16ec58 | 6162 | struct rq *rq_dest = cpu_rq(any_online_cpu(*CPU_MASK_ALL_PTR)); |
1da177e4 LT |
6163 | unsigned long flags; |
6164 | ||
6165 | local_irq_save(flags); | |
6166 | double_rq_lock(rq_src, rq_dest); | |
6167 | rq_dest->nr_uninterruptible += rq_src->nr_uninterruptible; | |
6168 | rq_src->nr_uninterruptible = 0; | |
6169 | double_rq_unlock(rq_src, rq_dest); | |
6170 | local_irq_restore(flags); | |
6171 | } | |
6172 | ||
6173 | /* Run through task list and migrate tasks from the dead cpu. */ | |
6174 | static void migrate_live_tasks(int src_cpu) | |
6175 | { | |
48f24c4d | 6176 | struct task_struct *p, *t; |
1da177e4 | 6177 | |
f7b4cddc | 6178 | read_lock(&tasklist_lock); |
1da177e4 | 6179 | |
48f24c4d IM |
6180 | do_each_thread(t, p) { |
6181 | if (p == current) | |
1da177e4 LT |
6182 | continue; |
6183 | ||
48f24c4d IM |
6184 | if (task_cpu(p) == src_cpu) |
6185 | move_task_off_dead_cpu(src_cpu, p); | |
6186 | } while_each_thread(t, p); | |
1da177e4 | 6187 | |
f7b4cddc | 6188 | read_unlock(&tasklist_lock); |
1da177e4 LT |
6189 | } |
6190 | ||
dd41f596 IM |
6191 | /* |
6192 | * Schedules idle task to be the next runnable task on current CPU. | |
94bc9a7b DA |
6193 | * It does so by boosting its priority to highest possible. |
6194 | * Used by CPU offline code. | |
1da177e4 LT |
6195 | */ |
6196 | void sched_idle_next(void) | |
6197 | { | |
48f24c4d | 6198 | int this_cpu = smp_processor_id(); |
70b97a7f | 6199 | struct rq *rq = cpu_rq(this_cpu); |
1da177e4 LT |
6200 | struct task_struct *p = rq->idle; |
6201 | unsigned long flags; | |
6202 | ||
6203 | /* cpu has to be offline */ | |
48f24c4d | 6204 | BUG_ON(cpu_online(this_cpu)); |
1da177e4 | 6205 | |
48f24c4d IM |
6206 | /* |
6207 | * Strictly not necessary since rest of the CPUs are stopped by now | |
6208 | * and interrupts disabled on the current cpu. | |
1da177e4 LT |
6209 | */ |
6210 | spin_lock_irqsave(&rq->lock, flags); | |
6211 | ||
dd41f596 | 6212 | __setscheduler(rq, p, SCHED_FIFO, MAX_RT_PRIO-1); |
48f24c4d | 6213 | |
94bc9a7b DA |
6214 | update_rq_clock(rq); |
6215 | activate_task(rq, p, 0); | |
1da177e4 LT |
6216 | |
6217 | spin_unlock_irqrestore(&rq->lock, flags); | |
6218 | } | |
6219 | ||
48f24c4d IM |
6220 | /* |
6221 | * Ensures that the idle task is using init_mm right before its cpu goes | |
1da177e4 LT |
6222 | * offline. |
6223 | */ | |
6224 | void idle_task_exit(void) | |
6225 | { | |
6226 | struct mm_struct *mm = current->active_mm; | |
6227 | ||
6228 | BUG_ON(cpu_online(smp_processor_id())); | |
6229 | ||
6230 | if (mm != &init_mm) | |
6231 | switch_mm(mm, &init_mm, current); | |
6232 | mmdrop(mm); | |
6233 | } | |
6234 | ||
054b9108 | 6235 | /* called under rq->lock with disabled interrupts */ |
36c8b586 | 6236 | static void migrate_dead(unsigned int dead_cpu, struct task_struct *p) |
1da177e4 | 6237 | { |
70b97a7f | 6238 | struct rq *rq = cpu_rq(dead_cpu); |
1da177e4 LT |
6239 | |
6240 | /* Must be exiting, otherwise would be on tasklist. */ | |
270f722d | 6241 | BUG_ON(!p->exit_state); |
1da177e4 LT |
6242 | |
6243 | /* Cannot have done final schedule yet: would have vanished. */ | |
c394cc9f | 6244 | BUG_ON(p->state == TASK_DEAD); |
1da177e4 | 6245 | |
48f24c4d | 6246 | get_task_struct(p); |
1da177e4 LT |
6247 | |
6248 | /* | |
6249 | * Drop lock around migration; if someone else moves it, | |
41a2d6cf | 6250 | * that's OK. No task can be added to this CPU, so iteration is |
1da177e4 LT |
6251 | * fine. |
6252 | */ | |
f7b4cddc | 6253 | spin_unlock_irq(&rq->lock); |
48f24c4d | 6254 | move_task_off_dead_cpu(dead_cpu, p); |
f7b4cddc | 6255 | spin_lock_irq(&rq->lock); |
1da177e4 | 6256 | |
48f24c4d | 6257 | put_task_struct(p); |
1da177e4 LT |
6258 | } |
6259 | ||
6260 | /* release_task() removes task from tasklist, so we won't find dead tasks. */ | |
6261 | static void migrate_dead_tasks(unsigned int dead_cpu) | |
6262 | { | |
70b97a7f | 6263 | struct rq *rq = cpu_rq(dead_cpu); |
dd41f596 | 6264 | struct task_struct *next; |
48f24c4d | 6265 | |
dd41f596 IM |
6266 | for ( ; ; ) { |
6267 | if (!rq->nr_running) | |
6268 | break; | |
a8e504d2 | 6269 | update_rq_clock(rq); |
ff95f3df | 6270 | next = pick_next_task(rq, rq->curr); |
dd41f596 IM |
6271 | if (!next) |
6272 | break; | |
79c53799 | 6273 | next->sched_class->put_prev_task(rq, next); |
dd41f596 | 6274 | migrate_dead(dead_cpu, next); |
e692ab53 | 6275 | |
1da177e4 LT |
6276 | } |
6277 | } | |
6278 | #endif /* CONFIG_HOTPLUG_CPU */ | |
6279 | ||
e692ab53 NP |
6280 | #if defined(CONFIG_SCHED_DEBUG) && defined(CONFIG_SYSCTL) |
6281 | ||
6282 | static struct ctl_table sd_ctl_dir[] = { | |
e0361851 AD |
6283 | { |
6284 | .procname = "sched_domain", | |
c57baf1e | 6285 | .mode = 0555, |
e0361851 | 6286 | }, |
38605cae | 6287 | {0, }, |
e692ab53 NP |
6288 | }; |
6289 | ||
6290 | static struct ctl_table sd_ctl_root[] = { | |
e0361851 | 6291 | { |
c57baf1e | 6292 | .ctl_name = CTL_KERN, |
e0361851 | 6293 | .procname = "kernel", |
c57baf1e | 6294 | .mode = 0555, |
e0361851 AD |
6295 | .child = sd_ctl_dir, |
6296 | }, | |
38605cae | 6297 | {0, }, |
e692ab53 NP |
6298 | }; |
6299 | ||
6300 | static struct ctl_table *sd_alloc_ctl_entry(int n) | |
6301 | { | |
6302 | struct ctl_table *entry = | |
5cf9f062 | 6303 | kcalloc(n, sizeof(struct ctl_table), GFP_KERNEL); |
e692ab53 | 6304 | |
e692ab53 NP |
6305 | return entry; |
6306 | } | |
6307 | ||
6382bc90 MM |
6308 | static void sd_free_ctl_entry(struct ctl_table **tablep) |
6309 | { | |
cd790076 | 6310 | struct ctl_table *entry; |
6382bc90 | 6311 | |
cd790076 MM |
6312 | /* |
6313 | * In the intermediate directories, both the child directory and | |
6314 | * procname are dynamically allocated and could fail but the mode | |
41a2d6cf | 6315 | * will always be set. In the lowest directory the names are |
cd790076 MM |
6316 | * static strings and all have proc handlers. |
6317 | */ | |
6318 | for (entry = *tablep; entry->mode; entry++) { | |
6382bc90 MM |
6319 | if (entry->child) |
6320 | sd_free_ctl_entry(&entry->child); | |
cd790076 MM |
6321 | if (entry->proc_handler == NULL) |
6322 | kfree(entry->procname); | |
6323 | } | |
6382bc90 MM |
6324 | |
6325 | kfree(*tablep); | |
6326 | *tablep = NULL; | |
6327 | } | |
6328 | ||
e692ab53 | 6329 | static void |
e0361851 | 6330 | set_table_entry(struct ctl_table *entry, |
e692ab53 NP |
6331 | const char *procname, void *data, int maxlen, |
6332 | mode_t mode, proc_handler *proc_handler) | |
6333 | { | |
e692ab53 NP |
6334 | entry->procname = procname; |
6335 | entry->data = data; | |
6336 | entry->maxlen = maxlen; | |
6337 | entry->mode = mode; | |
6338 | entry->proc_handler = proc_handler; | |
6339 | } | |
6340 | ||
6341 | static struct ctl_table * | |
6342 | sd_alloc_ctl_domain_table(struct sched_domain *sd) | |
6343 | { | |
a5d8c348 | 6344 | struct ctl_table *table = sd_alloc_ctl_entry(13); |
e692ab53 | 6345 | |
ad1cdc1d MM |
6346 | if (table == NULL) |
6347 | return NULL; | |
6348 | ||
e0361851 | 6349 | set_table_entry(&table[0], "min_interval", &sd->min_interval, |
e692ab53 | 6350 | sizeof(long), 0644, proc_doulongvec_minmax); |
e0361851 | 6351 | set_table_entry(&table[1], "max_interval", &sd->max_interval, |
e692ab53 | 6352 | sizeof(long), 0644, proc_doulongvec_minmax); |
e0361851 | 6353 | set_table_entry(&table[2], "busy_idx", &sd->busy_idx, |
e692ab53 | 6354 | sizeof(int), 0644, proc_dointvec_minmax); |
e0361851 | 6355 | set_table_entry(&table[3], "idle_idx", &sd->idle_idx, |
e692ab53 | 6356 | sizeof(int), 0644, proc_dointvec_minmax); |
e0361851 | 6357 | set_table_entry(&table[4], "newidle_idx", &sd->newidle_idx, |
e692ab53 | 6358 | sizeof(int), 0644, proc_dointvec_minmax); |
e0361851 | 6359 | set_table_entry(&table[5], "wake_idx", &sd->wake_idx, |
e692ab53 | 6360 | sizeof(int), 0644, proc_dointvec_minmax); |
e0361851 | 6361 | set_table_entry(&table[6], "forkexec_idx", &sd->forkexec_idx, |
e692ab53 | 6362 | sizeof(int), 0644, proc_dointvec_minmax); |
e0361851 | 6363 | set_table_entry(&table[7], "busy_factor", &sd->busy_factor, |
e692ab53 | 6364 | sizeof(int), 0644, proc_dointvec_minmax); |
e0361851 | 6365 | set_table_entry(&table[8], "imbalance_pct", &sd->imbalance_pct, |
e692ab53 | 6366 | sizeof(int), 0644, proc_dointvec_minmax); |
ace8b3d6 | 6367 | set_table_entry(&table[9], "cache_nice_tries", |
e692ab53 NP |
6368 | &sd->cache_nice_tries, |
6369 | sizeof(int), 0644, proc_dointvec_minmax); | |
ace8b3d6 | 6370 | set_table_entry(&table[10], "flags", &sd->flags, |
e692ab53 | 6371 | sizeof(int), 0644, proc_dointvec_minmax); |
a5d8c348 IM |
6372 | set_table_entry(&table[11], "name", sd->name, |
6373 | CORENAME_MAX_SIZE, 0444, proc_dostring); | |
6374 | /* &table[12] is terminator */ | |
e692ab53 NP |
6375 | |
6376 | return table; | |
6377 | } | |
6378 | ||
9a4e7159 | 6379 | static ctl_table *sd_alloc_ctl_cpu_table(int cpu) |
e692ab53 NP |
6380 | { |
6381 | struct ctl_table *entry, *table; | |
6382 | struct sched_domain *sd; | |
6383 | int domain_num = 0, i; | |
6384 | char buf[32]; | |
6385 | ||
6386 | for_each_domain(cpu, sd) | |
6387 | domain_num++; | |
6388 | entry = table = sd_alloc_ctl_entry(domain_num + 1); | |
ad1cdc1d MM |
6389 | if (table == NULL) |
6390 | return NULL; | |
e692ab53 NP |
6391 | |
6392 | i = 0; | |
6393 | for_each_domain(cpu, sd) { | |
6394 | snprintf(buf, 32, "domain%d", i); | |
e692ab53 | 6395 | entry->procname = kstrdup(buf, GFP_KERNEL); |
c57baf1e | 6396 | entry->mode = 0555; |
e692ab53 NP |
6397 | entry->child = sd_alloc_ctl_domain_table(sd); |
6398 | entry++; | |
6399 | i++; | |
6400 | } | |
6401 | return table; | |
6402 | } | |
6403 | ||
6404 | static struct ctl_table_header *sd_sysctl_header; | |
6382bc90 | 6405 | static void register_sched_domain_sysctl(void) |
e692ab53 NP |
6406 | { |
6407 | int i, cpu_num = num_online_cpus(); | |
6408 | struct ctl_table *entry = sd_alloc_ctl_entry(cpu_num + 1); | |
6409 | char buf[32]; | |
6410 | ||
7378547f MM |
6411 | WARN_ON(sd_ctl_dir[0].child); |
6412 | sd_ctl_dir[0].child = entry; | |
6413 | ||
ad1cdc1d MM |
6414 | if (entry == NULL) |
6415 | return; | |
6416 | ||
97b6ea7b | 6417 | for_each_online_cpu(i) { |
e692ab53 | 6418 | snprintf(buf, 32, "cpu%d", i); |
e692ab53 | 6419 | entry->procname = kstrdup(buf, GFP_KERNEL); |
c57baf1e | 6420 | entry->mode = 0555; |
e692ab53 | 6421 | entry->child = sd_alloc_ctl_cpu_table(i); |
97b6ea7b | 6422 | entry++; |
e692ab53 | 6423 | } |
7378547f MM |
6424 | |
6425 | WARN_ON(sd_sysctl_header); | |
e692ab53 NP |
6426 | sd_sysctl_header = register_sysctl_table(sd_ctl_root); |
6427 | } | |
6382bc90 | 6428 | |
7378547f | 6429 | /* may be called multiple times per register */ |
6382bc90 MM |
6430 | static void unregister_sched_domain_sysctl(void) |
6431 | { | |
7378547f MM |
6432 | if (sd_sysctl_header) |
6433 | unregister_sysctl_table(sd_sysctl_header); | |
6382bc90 | 6434 | sd_sysctl_header = NULL; |
7378547f MM |
6435 | if (sd_ctl_dir[0].child) |
6436 | sd_free_ctl_entry(&sd_ctl_dir[0].child); | |
6382bc90 | 6437 | } |
e692ab53 | 6438 | #else |
6382bc90 MM |
6439 | static void register_sched_domain_sysctl(void) |
6440 | { | |
6441 | } | |
6442 | static void unregister_sched_domain_sysctl(void) | |
e692ab53 NP |
6443 | { |
6444 | } | |
6445 | #endif | |
6446 | ||
1f11eb6a GH |
6447 | static void set_rq_online(struct rq *rq) |
6448 | { | |
6449 | if (!rq->online) { | |
6450 | const struct sched_class *class; | |
6451 | ||
6452 | cpu_set(rq->cpu, rq->rd->online); | |
6453 | rq->online = 1; | |
6454 | ||
6455 | for_each_class(class) { | |
6456 | if (class->rq_online) | |
6457 | class->rq_online(rq); | |
6458 | } | |
6459 | } | |
6460 | } | |
6461 | ||
6462 | static void set_rq_offline(struct rq *rq) | |
6463 | { | |
6464 | if (rq->online) { | |
6465 | const struct sched_class *class; | |
6466 | ||
6467 | for_each_class(class) { | |
6468 | if (class->rq_offline) | |
6469 | class->rq_offline(rq); | |
6470 | } | |
6471 | ||
6472 | cpu_clear(rq->cpu, rq->rd->online); | |
6473 | rq->online = 0; | |
6474 | } | |
6475 | } | |
6476 | ||
1da177e4 LT |
6477 | /* |
6478 | * migration_call - callback that gets triggered when a CPU is added. | |
6479 | * Here we can start up the necessary migration thread for the new CPU. | |
6480 | */ | |
48f24c4d IM |
6481 | static int __cpuinit |
6482 | migration_call(struct notifier_block *nfb, unsigned long action, void *hcpu) | |
1da177e4 | 6483 | { |
1da177e4 | 6484 | struct task_struct *p; |
48f24c4d | 6485 | int cpu = (long)hcpu; |
1da177e4 | 6486 | unsigned long flags; |
70b97a7f | 6487 | struct rq *rq; |
1da177e4 LT |
6488 | |
6489 | switch (action) { | |
5be9361c | 6490 | |
1da177e4 | 6491 | case CPU_UP_PREPARE: |
8bb78442 | 6492 | case CPU_UP_PREPARE_FROZEN: |
dd41f596 | 6493 | p = kthread_create(migration_thread, hcpu, "migration/%d", cpu); |
1da177e4 LT |
6494 | if (IS_ERR(p)) |
6495 | return NOTIFY_BAD; | |
1da177e4 LT |
6496 | kthread_bind(p, cpu); |
6497 | /* Must be high prio: stop_machine expects to yield to it. */ | |
6498 | rq = task_rq_lock(p, &flags); | |
dd41f596 | 6499 | __setscheduler(rq, p, SCHED_FIFO, MAX_RT_PRIO-1); |
1da177e4 LT |
6500 | task_rq_unlock(rq, &flags); |
6501 | cpu_rq(cpu)->migration_thread = p; | |
6502 | break; | |
48f24c4d | 6503 | |
1da177e4 | 6504 | case CPU_ONLINE: |
8bb78442 | 6505 | case CPU_ONLINE_FROZEN: |
3a4fa0a2 | 6506 | /* Strictly unnecessary, as first user will wake it. */ |
1da177e4 | 6507 | wake_up_process(cpu_rq(cpu)->migration_thread); |
1f94ef59 GH |
6508 | |
6509 | /* Update our root-domain */ | |
6510 | rq = cpu_rq(cpu); | |
6511 | spin_lock_irqsave(&rq->lock, flags); | |
6512 | if (rq->rd) { | |
6513 | BUG_ON(!cpu_isset(cpu, rq->rd->span)); | |
1f11eb6a GH |
6514 | |
6515 | set_rq_online(rq); | |
1f94ef59 GH |
6516 | } |
6517 | spin_unlock_irqrestore(&rq->lock, flags); | |
1da177e4 | 6518 | break; |
48f24c4d | 6519 | |
1da177e4 LT |
6520 | #ifdef CONFIG_HOTPLUG_CPU |
6521 | case CPU_UP_CANCELED: | |
8bb78442 | 6522 | case CPU_UP_CANCELED_FROZEN: |
fc75cdfa HC |
6523 | if (!cpu_rq(cpu)->migration_thread) |
6524 | break; | |
41a2d6cf | 6525 | /* Unbind it from offline cpu so it can run. Fall thru. */ |
a4c4af7c HC |
6526 | kthread_bind(cpu_rq(cpu)->migration_thread, |
6527 | any_online_cpu(cpu_online_map)); | |
1da177e4 LT |
6528 | kthread_stop(cpu_rq(cpu)->migration_thread); |
6529 | cpu_rq(cpu)->migration_thread = NULL; | |
6530 | break; | |
48f24c4d | 6531 | |
1da177e4 | 6532 | case CPU_DEAD: |
8bb78442 | 6533 | case CPU_DEAD_FROZEN: |
470fd646 | 6534 | cpuset_lock(); /* around calls to cpuset_cpus_allowed_lock() */ |
1da177e4 LT |
6535 | migrate_live_tasks(cpu); |
6536 | rq = cpu_rq(cpu); | |
6537 | kthread_stop(rq->migration_thread); | |
6538 | rq->migration_thread = NULL; | |
6539 | /* Idle task back to normal (off runqueue, low prio) */ | |
d2da272a | 6540 | spin_lock_irq(&rq->lock); |
a8e504d2 | 6541 | update_rq_clock(rq); |
2e1cb74a | 6542 | deactivate_task(rq, rq->idle, 0); |
1da177e4 | 6543 | rq->idle->static_prio = MAX_PRIO; |
dd41f596 IM |
6544 | __setscheduler(rq, rq->idle, SCHED_NORMAL, 0); |
6545 | rq->idle->sched_class = &idle_sched_class; | |
1da177e4 | 6546 | migrate_dead_tasks(cpu); |
d2da272a | 6547 | spin_unlock_irq(&rq->lock); |
470fd646 | 6548 | cpuset_unlock(); |
1da177e4 LT |
6549 | migrate_nr_uninterruptible(rq); |
6550 | BUG_ON(rq->nr_running != 0); | |
6551 | ||
41a2d6cf IM |
6552 | /* |
6553 | * No need to migrate the tasks: it was best-effort if | |
6554 | * they didn't take sched_hotcpu_mutex. Just wake up | |
6555 | * the requestors. | |
6556 | */ | |
1da177e4 LT |
6557 | spin_lock_irq(&rq->lock); |
6558 | while (!list_empty(&rq->migration_queue)) { | |
70b97a7f IM |
6559 | struct migration_req *req; |
6560 | ||
1da177e4 | 6561 | req = list_entry(rq->migration_queue.next, |
70b97a7f | 6562 | struct migration_req, list); |
1da177e4 LT |
6563 | list_del_init(&req->list); |
6564 | complete(&req->done); | |
6565 | } | |
6566 | spin_unlock_irq(&rq->lock); | |
6567 | break; | |
57d885fe | 6568 | |
08f503b0 GH |
6569 | case CPU_DYING: |
6570 | case CPU_DYING_FROZEN: | |
57d885fe GH |
6571 | /* Update our root-domain */ |
6572 | rq = cpu_rq(cpu); | |
6573 | spin_lock_irqsave(&rq->lock, flags); | |
6574 | if (rq->rd) { | |
6575 | BUG_ON(!cpu_isset(cpu, rq->rd->span)); | |
1f11eb6a | 6576 | set_rq_offline(rq); |
57d885fe GH |
6577 | } |
6578 | spin_unlock_irqrestore(&rq->lock, flags); | |
6579 | break; | |
1da177e4 LT |
6580 | #endif |
6581 | } | |
6582 | return NOTIFY_OK; | |
6583 | } | |
6584 | ||
6585 | /* Register at highest priority so that task migration (migrate_all_tasks) | |
6586 | * happens before everything else. | |
6587 | */ | |
26c2143b | 6588 | static struct notifier_block __cpuinitdata migration_notifier = { |
1da177e4 LT |
6589 | .notifier_call = migration_call, |
6590 | .priority = 10 | |
6591 | }; | |
6592 | ||
7babe8db | 6593 | static int __init migration_init(void) |
1da177e4 LT |
6594 | { |
6595 | void *cpu = (void *)(long)smp_processor_id(); | |
07dccf33 | 6596 | int err; |
48f24c4d IM |
6597 | |
6598 | /* Start one for the boot CPU: */ | |
07dccf33 AM |
6599 | err = migration_call(&migration_notifier, CPU_UP_PREPARE, cpu); |
6600 | BUG_ON(err == NOTIFY_BAD); | |
1da177e4 LT |
6601 | migration_call(&migration_notifier, CPU_ONLINE, cpu); |
6602 | register_cpu_notifier(&migration_notifier); | |
7babe8db EGM |
6603 | |
6604 | return err; | |
1da177e4 | 6605 | } |
7babe8db | 6606 | early_initcall(migration_init); |
1da177e4 LT |
6607 | #endif |
6608 | ||
6609 | #ifdef CONFIG_SMP | |
476f3534 | 6610 | |
3e9830dc | 6611 | #ifdef CONFIG_SCHED_DEBUG |
4dcf6aff | 6612 | |
7c16ec58 MT |
6613 | static int sched_domain_debug_one(struct sched_domain *sd, int cpu, int level, |
6614 | cpumask_t *groupmask) | |
1da177e4 | 6615 | { |
4dcf6aff | 6616 | struct sched_group *group = sd->groups; |
434d53b0 | 6617 | char str[256]; |
1da177e4 | 6618 | |
434d53b0 | 6619 | cpulist_scnprintf(str, sizeof(str), sd->span); |
7c16ec58 | 6620 | cpus_clear(*groupmask); |
4dcf6aff IM |
6621 | |
6622 | printk(KERN_DEBUG "%*s domain %d: ", level, "", level); | |
6623 | ||
6624 | if (!(sd->flags & SD_LOAD_BALANCE)) { | |
6625 | printk("does not load-balance\n"); | |
6626 | if (sd->parent) | |
6627 | printk(KERN_ERR "ERROR: !SD_LOAD_BALANCE domain" | |
6628 | " has parent"); | |
6629 | return -1; | |
41c7ce9a NP |
6630 | } |
6631 | ||
eefd796a | 6632 | printk(KERN_CONT "span %s level %s\n", str, sd->name); |
4dcf6aff IM |
6633 | |
6634 | if (!cpu_isset(cpu, sd->span)) { | |
6635 | printk(KERN_ERR "ERROR: domain->span does not contain " | |
6636 | "CPU%d\n", cpu); | |
6637 | } | |
6638 | if (!cpu_isset(cpu, group->cpumask)) { | |
6639 | printk(KERN_ERR "ERROR: domain->groups does not contain" | |
6640 | " CPU%d\n", cpu); | |
6641 | } | |
1da177e4 | 6642 | |
4dcf6aff | 6643 | printk(KERN_DEBUG "%*s groups:", level + 1, ""); |
1da177e4 | 6644 | do { |
4dcf6aff IM |
6645 | if (!group) { |
6646 | printk("\n"); | |
6647 | printk(KERN_ERR "ERROR: group is NULL\n"); | |
1da177e4 LT |
6648 | break; |
6649 | } | |
6650 | ||
4dcf6aff IM |
6651 | if (!group->__cpu_power) { |
6652 | printk(KERN_CONT "\n"); | |
6653 | printk(KERN_ERR "ERROR: domain->cpu_power not " | |
6654 | "set\n"); | |
6655 | break; | |
6656 | } | |
1da177e4 | 6657 | |
4dcf6aff IM |
6658 | if (!cpus_weight(group->cpumask)) { |
6659 | printk(KERN_CONT "\n"); | |
6660 | printk(KERN_ERR "ERROR: empty group\n"); | |
6661 | break; | |
6662 | } | |
1da177e4 | 6663 | |
7c16ec58 | 6664 | if (cpus_intersects(*groupmask, group->cpumask)) { |
4dcf6aff IM |
6665 | printk(KERN_CONT "\n"); |
6666 | printk(KERN_ERR "ERROR: repeated CPUs\n"); | |
6667 | break; | |
6668 | } | |
1da177e4 | 6669 | |
7c16ec58 | 6670 | cpus_or(*groupmask, *groupmask, group->cpumask); |
1da177e4 | 6671 | |
434d53b0 | 6672 | cpulist_scnprintf(str, sizeof(str), group->cpumask); |
4dcf6aff | 6673 | printk(KERN_CONT " %s", str); |
1da177e4 | 6674 | |
4dcf6aff IM |
6675 | group = group->next; |
6676 | } while (group != sd->groups); | |
6677 | printk(KERN_CONT "\n"); | |
1da177e4 | 6678 | |
7c16ec58 | 6679 | if (!cpus_equal(sd->span, *groupmask)) |
4dcf6aff | 6680 | printk(KERN_ERR "ERROR: groups don't span domain->span\n"); |
1da177e4 | 6681 | |
7c16ec58 | 6682 | if (sd->parent && !cpus_subset(*groupmask, sd->parent->span)) |
4dcf6aff IM |
6683 | printk(KERN_ERR "ERROR: parent span is not a superset " |
6684 | "of domain->span\n"); | |
6685 | return 0; | |
6686 | } | |
1da177e4 | 6687 | |
4dcf6aff IM |
6688 | static void sched_domain_debug(struct sched_domain *sd, int cpu) |
6689 | { | |
7c16ec58 | 6690 | cpumask_t *groupmask; |
4dcf6aff | 6691 | int level = 0; |
1da177e4 | 6692 | |
4dcf6aff IM |
6693 | if (!sd) { |
6694 | printk(KERN_DEBUG "CPU%d attaching NULL sched-domain.\n", cpu); | |
6695 | return; | |
6696 | } | |
1da177e4 | 6697 | |
4dcf6aff IM |
6698 | printk(KERN_DEBUG "CPU%d attaching sched-domain:\n", cpu); |
6699 | ||
7c16ec58 MT |
6700 | groupmask = kmalloc(sizeof(cpumask_t), GFP_KERNEL); |
6701 | if (!groupmask) { | |
6702 | printk(KERN_DEBUG "Cannot load-balance (out of memory)\n"); | |
6703 | return; | |
6704 | } | |
6705 | ||
4dcf6aff | 6706 | for (;;) { |
7c16ec58 | 6707 | if (sched_domain_debug_one(sd, cpu, level, groupmask)) |
4dcf6aff | 6708 | break; |
1da177e4 LT |
6709 | level++; |
6710 | sd = sd->parent; | |
33859f7f | 6711 | if (!sd) |
4dcf6aff IM |
6712 | break; |
6713 | } | |
7c16ec58 | 6714 | kfree(groupmask); |
1da177e4 | 6715 | } |
6d6bc0ad | 6716 | #else /* !CONFIG_SCHED_DEBUG */ |
48f24c4d | 6717 | # define sched_domain_debug(sd, cpu) do { } while (0) |
6d6bc0ad | 6718 | #endif /* CONFIG_SCHED_DEBUG */ |
1da177e4 | 6719 | |
1a20ff27 | 6720 | static int sd_degenerate(struct sched_domain *sd) |
245af2c7 SS |
6721 | { |
6722 | if (cpus_weight(sd->span) == 1) | |
6723 | return 1; | |
6724 | ||
6725 | /* Following flags need at least 2 groups */ | |
6726 | if (sd->flags & (SD_LOAD_BALANCE | | |
6727 | SD_BALANCE_NEWIDLE | | |
6728 | SD_BALANCE_FORK | | |
89c4710e SS |
6729 | SD_BALANCE_EXEC | |
6730 | SD_SHARE_CPUPOWER | | |
6731 | SD_SHARE_PKG_RESOURCES)) { | |
245af2c7 SS |
6732 | if (sd->groups != sd->groups->next) |
6733 | return 0; | |
6734 | } | |
6735 | ||
6736 | /* Following flags don't use groups */ | |
6737 | if (sd->flags & (SD_WAKE_IDLE | | |
6738 | SD_WAKE_AFFINE | | |
6739 | SD_WAKE_BALANCE)) | |
6740 | return 0; | |
6741 | ||
6742 | return 1; | |
6743 | } | |
6744 | ||
48f24c4d IM |
6745 | static int |
6746 | sd_parent_degenerate(struct sched_domain *sd, struct sched_domain *parent) | |
245af2c7 SS |
6747 | { |
6748 | unsigned long cflags = sd->flags, pflags = parent->flags; | |
6749 | ||
6750 | if (sd_degenerate(parent)) | |
6751 | return 1; | |
6752 | ||
6753 | if (!cpus_equal(sd->span, parent->span)) | |
6754 | return 0; | |
6755 | ||
6756 | /* Does parent contain flags not in child? */ | |
6757 | /* WAKE_BALANCE is a subset of WAKE_AFFINE */ | |
6758 | if (cflags & SD_WAKE_AFFINE) | |
6759 | pflags &= ~SD_WAKE_BALANCE; | |
6760 | /* Flags needing groups don't count if only 1 group in parent */ | |
6761 | if (parent->groups == parent->groups->next) { | |
6762 | pflags &= ~(SD_LOAD_BALANCE | | |
6763 | SD_BALANCE_NEWIDLE | | |
6764 | SD_BALANCE_FORK | | |
89c4710e SS |
6765 | SD_BALANCE_EXEC | |
6766 | SD_SHARE_CPUPOWER | | |
6767 | SD_SHARE_PKG_RESOURCES); | |
245af2c7 SS |
6768 | } |
6769 | if (~cflags & pflags) | |
6770 | return 0; | |
6771 | ||
6772 | return 1; | |
6773 | } | |
6774 | ||
57d885fe GH |
6775 | static void rq_attach_root(struct rq *rq, struct root_domain *rd) |
6776 | { | |
6777 | unsigned long flags; | |
57d885fe GH |
6778 | |
6779 | spin_lock_irqsave(&rq->lock, flags); | |
6780 | ||
6781 | if (rq->rd) { | |
6782 | struct root_domain *old_rd = rq->rd; | |
6783 | ||
1f11eb6a GH |
6784 | if (cpu_isset(rq->cpu, old_rd->online)) |
6785 | set_rq_offline(rq); | |
57d885fe | 6786 | |
dc938520 | 6787 | cpu_clear(rq->cpu, old_rd->span); |
dc938520 | 6788 | |
57d885fe GH |
6789 | if (atomic_dec_and_test(&old_rd->refcount)) |
6790 | kfree(old_rd); | |
6791 | } | |
6792 | ||
6793 | atomic_inc(&rd->refcount); | |
6794 | rq->rd = rd; | |
6795 | ||
dc938520 | 6796 | cpu_set(rq->cpu, rd->span); |
1f94ef59 | 6797 | if (cpu_isset(rq->cpu, cpu_online_map)) |
1f11eb6a | 6798 | set_rq_online(rq); |
57d885fe GH |
6799 | |
6800 | spin_unlock_irqrestore(&rq->lock, flags); | |
6801 | } | |
6802 | ||
dc938520 | 6803 | static void init_rootdomain(struct root_domain *rd) |
57d885fe GH |
6804 | { |
6805 | memset(rd, 0, sizeof(*rd)); | |
6806 | ||
dc938520 GH |
6807 | cpus_clear(rd->span); |
6808 | cpus_clear(rd->online); | |
6e0534f2 GH |
6809 | |
6810 | cpupri_init(&rd->cpupri); | |
57d885fe GH |
6811 | } |
6812 | ||
6813 | static void init_defrootdomain(void) | |
6814 | { | |
dc938520 | 6815 | init_rootdomain(&def_root_domain); |
57d885fe GH |
6816 | atomic_set(&def_root_domain.refcount, 1); |
6817 | } | |
6818 | ||
dc938520 | 6819 | static struct root_domain *alloc_rootdomain(void) |
57d885fe GH |
6820 | { |
6821 | struct root_domain *rd; | |
6822 | ||
6823 | rd = kmalloc(sizeof(*rd), GFP_KERNEL); | |
6824 | if (!rd) | |
6825 | return NULL; | |
6826 | ||
dc938520 | 6827 | init_rootdomain(rd); |
57d885fe GH |
6828 | |
6829 | return rd; | |
6830 | } | |
6831 | ||
1da177e4 | 6832 | /* |
0eab9146 | 6833 | * Attach the domain 'sd' to 'cpu' as its base domain. Callers must |
1da177e4 LT |
6834 | * hold the hotplug lock. |
6835 | */ | |
0eab9146 IM |
6836 | static void |
6837 | cpu_attach_domain(struct sched_domain *sd, struct root_domain *rd, int cpu) | |
1da177e4 | 6838 | { |
70b97a7f | 6839 | struct rq *rq = cpu_rq(cpu); |
245af2c7 SS |
6840 | struct sched_domain *tmp; |
6841 | ||
6842 | /* Remove the sched domains which do not contribute to scheduling. */ | |
f29c9b1c | 6843 | for (tmp = sd; tmp; ) { |
245af2c7 SS |
6844 | struct sched_domain *parent = tmp->parent; |
6845 | if (!parent) | |
6846 | break; | |
f29c9b1c | 6847 | |
1a848870 | 6848 | if (sd_parent_degenerate(tmp, parent)) { |
245af2c7 | 6849 | tmp->parent = parent->parent; |
1a848870 SS |
6850 | if (parent->parent) |
6851 | parent->parent->child = tmp; | |
f29c9b1c LZ |
6852 | } else |
6853 | tmp = tmp->parent; | |
245af2c7 SS |
6854 | } |
6855 | ||
1a848870 | 6856 | if (sd && sd_degenerate(sd)) { |
245af2c7 | 6857 | sd = sd->parent; |
1a848870 SS |
6858 | if (sd) |
6859 | sd->child = NULL; | |
6860 | } | |
1da177e4 LT |
6861 | |
6862 | sched_domain_debug(sd, cpu); | |
6863 | ||
57d885fe | 6864 | rq_attach_root(rq, rd); |
674311d5 | 6865 | rcu_assign_pointer(rq->sd, sd); |
1da177e4 LT |
6866 | } |
6867 | ||
6868 | /* cpus with isolated domains */ | |
67af63a6 | 6869 | static cpumask_t cpu_isolated_map = CPU_MASK_NONE; |
1da177e4 LT |
6870 | |
6871 | /* Setup the mask of cpus configured for isolated domains */ | |
6872 | static int __init isolated_cpu_setup(char *str) | |
6873 | { | |
13b40c1e MT |
6874 | static int __initdata ints[NR_CPUS]; |
6875 | int i; | |
1da177e4 LT |
6876 | |
6877 | str = get_options(str, ARRAY_SIZE(ints), ints); | |
6878 | cpus_clear(cpu_isolated_map); | |
6879 | for (i = 1; i <= ints[0]; i++) | |
6880 | if (ints[i] < NR_CPUS) | |
6881 | cpu_set(ints[i], cpu_isolated_map); | |
6882 | return 1; | |
6883 | } | |
6884 | ||
8927f494 | 6885 | __setup("isolcpus=", isolated_cpu_setup); |
1da177e4 LT |
6886 | |
6887 | /* | |
6711cab4 SS |
6888 | * init_sched_build_groups takes the cpumask we wish to span, and a pointer |
6889 | * to a function which identifies what group(along with sched group) a CPU | |
6890 | * belongs to. The return value of group_fn must be a >= 0 and < NR_CPUS | |
6891 | * (due to the fact that we keep track of groups covered with a cpumask_t). | |
1da177e4 LT |
6892 | * |
6893 | * init_sched_build_groups will build a circular linked list of the groups | |
6894 | * covered by the given span, and will set each group's ->cpumask correctly, | |
6895 | * and ->cpu_power to 0. | |
6896 | */ | |
a616058b | 6897 | static void |
7c16ec58 | 6898 | init_sched_build_groups(const cpumask_t *span, const cpumask_t *cpu_map, |
6711cab4 | 6899 | int (*group_fn)(int cpu, const cpumask_t *cpu_map, |
7c16ec58 MT |
6900 | struct sched_group **sg, |
6901 | cpumask_t *tmpmask), | |
6902 | cpumask_t *covered, cpumask_t *tmpmask) | |
1da177e4 LT |
6903 | { |
6904 | struct sched_group *first = NULL, *last = NULL; | |
1da177e4 LT |
6905 | int i; |
6906 | ||
7c16ec58 MT |
6907 | cpus_clear(*covered); |
6908 | ||
abcd083a | 6909 | for_each_cpu(i, span) { |
6711cab4 | 6910 | struct sched_group *sg; |
7c16ec58 | 6911 | int group = group_fn(i, cpu_map, &sg, tmpmask); |
1da177e4 LT |
6912 | int j; |
6913 | ||
7c16ec58 | 6914 | if (cpu_isset(i, *covered)) |
1da177e4 LT |
6915 | continue; |
6916 | ||
7c16ec58 | 6917 | cpus_clear(sg->cpumask); |
5517d86b | 6918 | sg->__cpu_power = 0; |
1da177e4 | 6919 | |
abcd083a | 6920 | for_each_cpu(j, span) { |
7c16ec58 | 6921 | if (group_fn(j, cpu_map, NULL, tmpmask) != group) |
1da177e4 LT |
6922 | continue; |
6923 | ||
7c16ec58 | 6924 | cpu_set(j, *covered); |
1da177e4 LT |
6925 | cpu_set(j, sg->cpumask); |
6926 | } | |
6927 | if (!first) | |
6928 | first = sg; | |
6929 | if (last) | |
6930 | last->next = sg; | |
6931 | last = sg; | |
6932 | } | |
6933 | last->next = first; | |
6934 | } | |
6935 | ||
9c1cfda2 | 6936 | #define SD_NODES_PER_DOMAIN 16 |
1da177e4 | 6937 | |
9c1cfda2 | 6938 | #ifdef CONFIG_NUMA |
198e2f18 | 6939 | |
9c1cfda2 JH |
6940 | /** |
6941 | * find_next_best_node - find the next node to include in a sched_domain | |
6942 | * @node: node whose sched_domain we're building | |
6943 | * @used_nodes: nodes already in the sched_domain | |
6944 | * | |
41a2d6cf | 6945 | * Find the next node to include in a given scheduling domain. Simply |
9c1cfda2 JH |
6946 | * finds the closest node not already in the @used_nodes map. |
6947 | * | |
6948 | * Should use nodemask_t. | |
6949 | */ | |
c5f59f08 | 6950 | static int find_next_best_node(int node, nodemask_t *used_nodes) |
9c1cfda2 JH |
6951 | { |
6952 | int i, n, val, min_val, best_node = 0; | |
6953 | ||
6954 | min_val = INT_MAX; | |
6955 | ||
076ac2af | 6956 | for (i = 0; i < nr_node_ids; i++) { |
9c1cfda2 | 6957 | /* Start at @node */ |
076ac2af | 6958 | n = (node + i) % nr_node_ids; |
9c1cfda2 JH |
6959 | |
6960 | if (!nr_cpus_node(n)) | |
6961 | continue; | |
6962 | ||
6963 | /* Skip already used nodes */ | |
c5f59f08 | 6964 | if (node_isset(n, *used_nodes)) |
9c1cfda2 JH |
6965 | continue; |
6966 | ||
6967 | /* Simple min distance search */ | |
6968 | val = node_distance(node, n); | |
6969 | ||
6970 | if (val < min_val) { | |
6971 | min_val = val; | |
6972 | best_node = n; | |
6973 | } | |
6974 | } | |
6975 | ||
c5f59f08 | 6976 | node_set(best_node, *used_nodes); |
9c1cfda2 JH |
6977 | return best_node; |
6978 | } | |
6979 | ||
6980 | /** | |
6981 | * sched_domain_node_span - get a cpumask for a node's sched_domain | |
6982 | * @node: node whose cpumask we're constructing | |
73486722 | 6983 | * @span: resulting cpumask |
9c1cfda2 | 6984 | * |
41a2d6cf | 6985 | * Given a node, construct a good cpumask for its sched_domain to span. It |
9c1cfda2 JH |
6986 | * should be one that prevents unnecessary balancing, but also spreads tasks |
6987 | * out optimally. | |
6988 | */ | |
4bdbaad3 | 6989 | static void sched_domain_node_span(int node, cpumask_t *span) |
9c1cfda2 | 6990 | { |
c5f59f08 | 6991 | nodemask_t used_nodes; |
c5f59f08 | 6992 | node_to_cpumask_ptr(nodemask, node); |
48f24c4d | 6993 | int i; |
9c1cfda2 | 6994 | |
4bdbaad3 | 6995 | cpus_clear(*span); |
c5f59f08 | 6996 | nodes_clear(used_nodes); |
9c1cfda2 | 6997 | |
4bdbaad3 | 6998 | cpus_or(*span, *span, *nodemask); |
c5f59f08 | 6999 | node_set(node, used_nodes); |
9c1cfda2 JH |
7000 | |
7001 | for (i = 1; i < SD_NODES_PER_DOMAIN; i++) { | |
c5f59f08 | 7002 | int next_node = find_next_best_node(node, &used_nodes); |
48f24c4d | 7003 | |
c5f59f08 | 7004 | node_to_cpumask_ptr_next(nodemask, next_node); |
4bdbaad3 | 7005 | cpus_or(*span, *span, *nodemask); |
9c1cfda2 | 7006 | } |
9c1cfda2 | 7007 | } |
6d6bc0ad | 7008 | #endif /* CONFIG_NUMA */ |
9c1cfda2 | 7009 | |
5c45bf27 | 7010 | int sched_smt_power_savings = 0, sched_mc_power_savings = 0; |
48f24c4d | 7011 | |
9c1cfda2 | 7012 | /* |
48f24c4d | 7013 | * SMT sched-domains: |
9c1cfda2 | 7014 | */ |
1da177e4 LT |
7015 | #ifdef CONFIG_SCHED_SMT |
7016 | static DEFINE_PER_CPU(struct sched_domain, cpu_domains); | |
6711cab4 | 7017 | static DEFINE_PER_CPU(struct sched_group, sched_group_cpus); |
48f24c4d | 7018 | |
41a2d6cf | 7019 | static int |
7c16ec58 MT |
7020 | cpu_to_cpu_group(int cpu, const cpumask_t *cpu_map, struct sched_group **sg, |
7021 | cpumask_t *unused) | |
1da177e4 | 7022 | { |
6711cab4 SS |
7023 | if (sg) |
7024 | *sg = &per_cpu(sched_group_cpus, cpu); | |
1da177e4 LT |
7025 | return cpu; |
7026 | } | |
6d6bc0ad | 7027 | #endif /* CONFIG_SCHED_SMT */ |
1da177e4 | 7028 | |
48f24c4d IM |
7029 | /* |
7030 | * multi-core sched-domains: | |
7031 | */ | |
1e9f28fa SS |
7032 | #ifdef CONFIG_SCHED_MC |
7033 | static DEFINE_PER_CPU(struct sched_domain, core_domains); | |
6711cab4 | 7034 | static DEFINE_PER_CPU(struct sched_group, sched_group_core); |
6d6bc0ad | 7035 | #endif /* CONFIG_SCHED_MC */ |
1e9f28fa SS |
7036 | |
7037 | #if defined(CONFIG_SCHED_MC) && defined(CONFIG_SCHED_SMT) | |
41a2d6cf | 7038 | static int |
7c16ec58 MT |
7039 | cpu_to_core_group(int cpu, const cpumask_t *cpu_map, struct sched_group **sg, |
7040 | cpumask_t *mask) | |
1e9f28fa | 7041 | { |
6711cab4 | 7042 | int group; |
7c16ec58 MT |
7043 | |
7044 | *mask = per_cpu(cpu_sibling_map, cpu); | |
7045 | cpus_and(*mask, *mask, *cpu_map); | |
7046 | group = first_cpu(*mask); | |
6711cab4 SS |
7047 | if (sg) |
7048 | *sg = &per_cpu(sched_group_core, group); | |
7049 | return group; | |
1e9f28fa SS |
7050 | } |
7051 | #elif defined(CONFIG_SCHED_MC) | |
41a2d6cf | 7052 | static int |
7c16ec58 MT |
7053 | cpu_to_core_group(int cpu, const cpumask_t *cpu_map, struct sched_group **sg, |
7054 | cpumask_t *unused) | |
1e9f28fa | 7055 | { |
6711cab4 SS |
7056 | if (sg) |
7057 | *sg = &per_cpu(sched_group_core, cpu); | |
1e9f28fa SS |
7058 | return cpu; |
7059 | } | |
7060 | #endif | |
7061 | ||
1da177e4 | 7062 | static DEFINE_PER_CPU(struct sched_domain, phys_domains); |
6711cab4 | 7063 | static DEFINE_PER_CPU(struct sched_group, sched_group_phys); |
48f24c4d | 7064 | |
41a2d6cf | 7065 | static int |
7c16ec58 MT |
7066 | cpu_to_phys_group(int cpu, const cpumask_t *cpu_map, struct sched_group **sg, |
7067 | cpumask_t *mask) | |
1da177e4 | 7068 | { |
6711cab4 | 7069 | int group; |
48f24c4d | 7070 | #ifdef CONFIG_SCHED_MC |
7c16ec58 MT |
7071 | *mask = cpu_coregroup_map(cpu); |
7072 | cpus_and(*mask, *mask, *cpu_map); | |
7073 | group = first_cpu(*mask); | |
1e9f28fa | 7074 | #elif defined(CONFIG_SCHED_SMT) |
7c16ec58 MT |
7075 | *mask = per_cpu(cpu_sibling_map, cpu); |
7076 | cpus_and(*mask, *mask, *cpu_map); | |
7077 | group = first_cpu(*mask); | |
1da177e4 | 7078 | #else |
6711cab4 | 7079 | group = cpu; |
1da177e4 | 7080 | #endif |
6711cab4 SS |
7081 | if (sg) |
7082 | *sg = &per_cpu(sched_group_phys, group); | |
7083 | return group; | |
1da177e4 LT |
7084 | } |
7085 | ||
7086 | #ifdef CONFIG_NUMA | |
1da177e4 | 7087 | /* |
9c1cfda2 JH |
7088 | * The init_sched_build_groups can't handle what we want to do with node |
7089 | * groups, so roll our own. Now each node has its own list of groups which | |
7090 | * gets dynamically allocated. | |
1da177e4 | 7091 | */ |
9c1cfda2 | 7092 | static DEFINE_PER_CPU(struct sched_domain, node_domains); |
434d53b0 | 7093 | static struct sched_group ***sched_group_nodes_bycpu; |
1da177e4 | 7094 | |
9c1cfda2 | 7095 | static DEFINE_PER_CPU(struct sched_domain, allnodes_domains); |
6711cab4 | 7096 | static DEFINE_PER_CPU(struct sched_group, sched_group_allnodes); |
9c1cfda2 | 7097 | |
6711cab4 | 7098 | static int cpu_to_allnodes_group(int cpu, const cpumask_t *cpu_map, |
7c16ec58 | 7099 | struct sched_group **sg, cpumask_t *nodemask) |
9c1cfda2 | 7100 | { |
6711cab4 | 7101 | int group; |
ea6f18ed | 7102 | node_to_cpumask_ptr(pnodemask, cpu_to_node(cpu)); |
6711cab4 | 7103 | |
ea6f18ed | 7104 | cpus_and(*nodemask, *pnodemask, *cpu_map); |
7c16ec58 | 7105 | group = first_cpu(*nodemask); |
6711cab4 SS |
7106 | |
7107 | if (sg) | |
7108 | *sg = &per_cpu(sched_group_allnodes, group); | |
7109 | return group; | |
1da177e4 | 7110 | } |
6711cab4 | 7111 | |
08069033 SS |
7112 | static void init_numa_sched_groups_power(struct sched_group *group_head) |
7113 | { | |
7114 | struct sched_group *sg = group_head; | |
7115 | int j; | |
7116 | ||
7117 | if (!sg) | |
7118 | return; | |
3a5c359a | 7119 | do { |
abcd083a | 7120 | for_each_cpu(j, &sg->cpumask) { |
3a5c359a | 7121 | struct sched_domain *sd; |
08069033 | 7122 | |
3a5c359a AK |
7123 | sd = &per_cpu(phys_domains, j); |
7124 | if (j != first_cpu(sd->groups->cpumask)) { | |
7125 | /* | |
7126 | * Only add "power" once for each | |
7127 | * physical package. | |
7128 | */ | |
7129 | continue; | |
7130 | } | |
08069033 | 7131 | |
3a5c359a AK |
7132 | sg_inc_cpu_power(sg, sd->groups->__cpu_power); |
7133 | } | |
7134 | sg = sg->next; | |
7135 | } while (sg != group_head); | |
08069033 | 7136 | } |
6d6bc0ad | 7137 | #endif /* CONFIG_NUMA */ |
1da177e4 | 7138 | |
a616058b | 7139 | #ifdef CONFIG_NUMA |
51888ca2 | 7140 | /* Free memory allocated for various sched_group structures */ |
7c16ec58 | 7141 | static void free_sched_groups(const cpumask_t *cpu_map, cpumask_t *nodemask) |
51888ca2 | 7142 | { |
a616058b | 7143 | int cpu, i; |
51888ca2 | 7144 | |
abcd083a | 7145 | for_each_cpu(cpu, cpu_map) { |
51888ca2 SV |
7146 | struct sched_group **sched_group_nodes |
7147 | = sched_group_nodes_bycpu[cpu]; | |
7148 | ||
51888ca2 SV |
7149 | if (!sched_group_nodes) |
7150 | continue; | |
7151 | ||
076ac2af | 7152 | for (i = 0; i < nr_node_ids; i++) { |
51888ca2 | 7153 | struct sched_group *oldsg, *sg = sched_group_nodes[i]; |
ea6f18ed | 7154 | node_to_cpumask_ptr(pnodemask, i); |
51888ca2 | 7155 | |
ea6f18ed | 7156 | cpus_and(*nodemask, *pnodemask, *cpu_map); |
7c16ec58 | 7157 | if (cpus_empty(*nodemask)) |
51888ca2 SV |
7158 | continue; |
7159 | ||
7160 | if (sg == NULL) | |
7161 | continue; | |
7162 | sg = sg->next; | |
7163 | next_sg: | |
7164 | oldsg = sg; | |
7165 | sg = sg->next; | |
7166 | kfree(oldsg); | |
7167 | if (oldsg != sched_group_nodes[i]) | |
7168 | goto next_sg; | |
7169 | } | |
7170 | kfree(sched_group_nodes); | |
7171 | sched_group_nodes_bycpu[cpu] = NULL; | |
7172 | } | |
51888ca2 | 7173 | } |
6d6bc0ad | 7174 | #else /* !CONFIG_NUMA */ |
7c16ec58 | 7175 | static void free_sched_groups(const cpumask_t *cpu_map, cpumask_t *nodemask) |
a616058b SS |
7176 | { |
7177 | } | |
6d6bc0ad | 7178 | #endif /* CONFIG_NUMA */ |
51888ca2 | 7179 | |
89c4710e SS |
7180 | /* |
7181 | * Initialize sched groups cpu_power. | |
7182 | * | |
7183 | * cpu_power indicates the capacity of sched group, which is used while | |
7184 | * distributing the load between different sched groups in a sched domain. | |
7185 | * Typically cpu_power for all the groups in a sched domain will be same unless | |
7186 | * there are asymmetries in the topology. If there are asymmetries, group | |
7187 | * having more cpu_power will pickup more load compared to the group having | |
7188 | * less cpu_power. | |
7189 | * | |
7190 | * cpu_power will be a multiple of SCHED_LOAD_SCALE. This multiple represents | |
7191 | * the maximum number of tasks a group can handle in the presence of other idle | |
7192 | * or lightly loaded groups in the same sched domain. | |
7193 | */ | |
7194 | static void init_sched_groups_power(int cpu, struct sched_domain *sd) | |
7195 | { | |
7196 | struct sched_domain *child; | |
7197 | struct sched_group *group; | |
7198 | ||
7199 | WARN_ON(!sd || !sd->groups); | |
7200 | ||
7201 | if (cpu != first_cpu(sd->groups->cpumask)) | |
7202 | return; | |
7203 | ||
7204 | child = sd->child; | |
7205 | ||
5517d86b ED |
7206 | sd->groups->__cpu_power = 0; |
7207 | ||
89c4710e SS |
7208 | /* |
7209 | * For perf policy, if the groups in child domain share resources | |
7210 | * (for example cores sharing some portions of the cache hierarchy | |
7211 | * or SMT), then set this domain groups cpu_power such that each group | |
7212 | * can handle only one task, when there are other idle groups in the | |
7213 | * same sched domain. | |
7214 | */ | |
7215 | if (!child || (!(sd->flags & SD_POWERSAVINGS_BALANCE) && | |
7216 | (child->flags & | |
7217 | (SD_SHARE_CPUPOWER | SD_SHARE_PKG_RESOURCES)))) { | |
5517d86b | 7218 | sg_inc_cpu_power(sd->groups, SCHED_LOAD_SCALE); |
89c4710e SS |
7219 | return; |
7220 | } | |
7221 | ||
89c4710e SS |
7222 | /* |
7223 | * add cpu_power of each child group to this groups cpu_power | |
7224 | */ | |
7225 | group = child->groups; | |
7226 | do { | |
5517d86b | 7227 | sg_inc_cpu_power(sd->groups, group->__cpu_power); |
89c4710e SS |
7228 | group = group->next; |
7229 | } while (group != child->groups); | |
7230 | } | |
7231 | ||
7c16ec58 MT |
7232 | /* |
7233 | * Initializers for schedule domains | |
7234 | * Non-inlined to reduce accumulated stack pressure in build_sched_domains() | |
7235 | */ | |
7236 | ||
a5d8c348 IM |
7237 | #ifdef CONFIG_SCHED_DEBUG |
7238 | # define SD_INIT_NAME(sd, type) sd->name = #type | |
7239 | #else | |
7240 | # define SD_INIT_NAME(sd, type) do { } while (0) | |
7241 | #endif | |
7242 | ||
7c16ec58 | 7243 | #define SD_INIT(sd, type) sd_init_##type(sd) |
a5d8c348 | 7244 | |
7c16ec58 MT |
7245 | #define SD_INIT_FUNC(type) \ |
7246 | static noinline void sd_init_##type(struct sched_domain *sd) \ | |
7247 | { \ | |
7248 | memset(sd, 0, sizeof(*sd)); \ | |
7249 | *sd = SD_##type##_INIT; \ | |
1d3504fc | 7250 | sd->level = SD_LV_##type; \ |
a5d8c348 | 7251 | SD_INIT_NAME(sd, type); \ |
7c16ec58 MT |
7252 | } |
7253 | ||
7254 | SD_INIT_FUNC(CPU) | |
7255 | #ifdef CONFIG_NUMA | |
7256 | SD_INIT_FUNC(ALLNODES) | |
7257 | SD_INIT_FUNC(NODE) | |
7258 | #endif | |
7259 | #ifdef CONFIG_SCHED_SMT | |
7260 | SD_INIT_FUNC(SIBLING) | |
7261 | #endif | |
7262 | #ifdef CONFIG_SCHED_MC | |
7263 | SD_INIT_FUNC(MC) | |
7264 | #endif | |
7265 | ||
7266 | /* | |
7267 | * To minimize stack usage kmalloc room for cpumasks and share the | |
7268 | * space as the usage in build_sched_domains() dictates. Used only | |
7269 | * if the amount of space is significant. | |
7270 | */ | |
7271 | struct allmasks { | |
7272 | cpumask_t tmpmask; /* make this one first */ | |
7273 | union { | |
7274 | cpumask_t nodemask; | |
7275 | cpumask_t this_sibling_map; | |
7276 | cpumask_t this_core_map; | |
7277 | }; | |
7278 | cpumask_t send_covered; | |
7279 | ||
7280 | #ifdef CONFIG_NUMA | |
7281 | cpumask_t domainspan; | |
7282 | cpumask_t covered; | |
7283 | cpumask_t notcovered; | |
7284 | #endif | |
7285 | }; | |
7286 | ||
7287 | #if NR_CPUS > 128 | |
6d21cd62 LZ |
7288 | #define SCHED_CPUMASK_DECLARE(v) struct allmasks *v |
7289 | static inline void sched_cpumask_alloc(struct allmasks **masks) | |
7290 | { | |
7291 | *masks = kmalloc(sizeof(**masks), GFP_KERNEL); | |
7292 | } | |
7293 | static inline void sched_cpumask_free(struct allmasks *masks) | |
7294 | { | |
7295 | kfree(masks); | |
7296 | } | |
7c16ec58 | 7297 | #else |
6d21cd62 LZ |
7298 | #define SCHED_CPUMASK_DECLARE(v) struct allmasks _v, *v = &_v |
7299 | static inline void sched_cpumask_alloc(struct allmasks **masks) | |
7300 | { } | |
7301 | static inline void sched_cpumask_free(struct allmasks *masks) | |
7302 | { } | |
7c16ec58 MT |
7303 | #endif |
7304 | ||
7305 | #define SCHED_CPUMASK_VAR(v, a) cpumask_t *v = (cpumask_t *) \ | |
7306 | ((unsigned long)(a) + offsetof(struct allmasks, v)) | |
7307 | ||
1d3504fc HS |
7308 | static int default_relax_domain_level = -1; |
7309 | ||
7310 | static int __init setup_relax_domain_level(char *str) | |
7311 | { | |
30e0e178 LZ |
7312 | unsigned long val; |
7313 | ||
7314 | val = simple_strtoul(str, NULL, 0); | |
7315 | if (val < SD_LV_MAX) | |
7316 | default_relax_domain_level = val; | |
7317 | ||
1d3504fc HS |
7318 | return 1; |
7319 | } | |
7320 | __setup("relax_domain_level=", setup_relax_domain_level); | |
7321 | ||
7322 | static void set_domain_attribute(struct sched_domain *sd, | |
7323 | struct sched_domain_attr *attr) | |
7324 | { | |
7325 | int request; | |
7326 | ||
7327 | if (!attr || attr->relax_domain_level < 0) { | |
7328 | if (default_relax_domain_level < 0) | |
7329 | return; | |
7330 | else | |
7331 | request = default_relax_domain_level; | |
7332 | } else | |
7333 | request = attr->relax_domain_level; | |
7334 | if (request < sd->level) { | |
7335 | /* turn off idle balance on this domain */ | |
7336 | sd->flags &= ~(SD_WAKE_IDLE|SD_BALANCE_NEWIDLE); | |
7337 | } else { | |
7338 | /* turn on idle balance on this domain */ | |
7339 | sd->flags |= (SD_WAKE_IDLE_FAR|SD_BALANCE_NEWIDLE); | |
7340 | } | |
7341 | } | |
7342 | ||
1da177e4 | 7343 | /* |
1a20ff27 DG |
7344 | * Build sched domains for a given set of cpus and attach the sched domains |
7345 | * to the individual cpus | |
1da177e4 | 7346 | */ |
1d3504fc HS |
7347 | static int __build_sched_domains(const cpumask_t *cpu_map, |
7348 | struct sched_domain_attr *attr) | |
1da177e4 LT |
7349 | { |
7350 | int i; | |
57d885fe | 7351 | struct root_domain *rd; |
7c16ec58 MT |
7352 | SCHED_CPUMASK_DECLARE(allmasks); |
7353 | cpumask_t *tmpmask; | |
d1b55138 JH |
7354 | #ifdef CONFIG_NUMA |
7355 | struct sched_group **sched_group_nodes = NULL; | |
6711cab4 | 7356 | int sd_allnodes = 0; |
d1b55138 JH |
7357 | |
7358 | /* | |
7359 | * Allocate the per-node list of sched groups | |
7360 | */ | |
076ac2af | 7361 | sched_group_nodes = kcalloc(nr_node_ids, sizeof(struct sched_group *), |
41a2d6cf | 7362 | GFP_KERNEL); |
d1b55138 JH |
7363 | if (!sched_group_nodes) { |
7364 | printk(KERN_WARNING "Can not alloc sched group node list\n"); | |
51888ca2 | 7365 | return -ENOMEM; |
d1b55138 | 7366 | } |
d1b55138 | 7367 | #endif |
1da177e4 | 7368 | |
dc938520 | 7369 | rd = alloc_rootdomain(); |
57d885fe GH |
7370 | if (!rd) { |
7371 | printk(KERN_WARNING "Cannot alloc root domain\n"); | |
7c16ec58 MT |
7372 | #ifdef CONFIG_NUMA |
7373 | kfree(sched_group_nodes); | |
7374 | #endif | |
57d885fe GH |
7375 | return -ENOMEM; |
7376 | } | |
7377 | ||
7c16ec58 | 7378 | /* get space for all scratch cpumask variables */ |
6d21cd62 | 7379 | sched_cpumask_alloc(&allmasks); |
7c16ec58 MT |
7380 | if (!allmasks) { |
7381 | printk(KERN_WARNING "Cannot alloc cpumask array\n"); | |
7382 | kfree(rd); | |
7383 | #ifdef CONFIG_NUMA | |
7384 | kfree(sched_group_nodes); | |
7385 | #endif | |
7386 | return -ENOMEM; | |
7387 | } | |
6d21cd62 | 7388 | |
7c16ec58 MT |
7389 | tmpmask = (cpumask_t *)allmasks; |
7390 | ||
7391 | ||
7392 | #ifdef CONFIG_NUMA | |
7393 | sched_group_nodes_bycpu[first_cpu(*cpu_map)] = sched_group_nodes; | |
7394 | #endif | |
7395 | ||
1da177e4 | 7396 | /* |
1a20ff27 | 7397 | * Set up domains for cpus specified by the cpu_map. |
1da177e4 | 7398 | */ |
abcd083a | 7399 | for_each_cpu(i, cpu_map) { |
1da177e4 | 7400 | struct sched_domain *sd = NULL, *p; |
7c16ec58 | 7401 | SCHED_CPUMASK_VAR(nodemask, allmasks); |
1da177e4 | 7402 | |
7c16ec58 MT |
7403 | *nodemask = node_to_cpumask(cpu_to_node(i)); |
7404 | cpus_and(*nodemask, *nodemask, *cpu_map); | |
1da177e4 LT |
7405 | |
7406 | #ifdef CONFIG_NUMA | |
dd41f596 | 7407 | if (cpus_weight(*cpu_map) > |
7c16ec58 | 7408 | SD_NODES_PER_DOMAIN*cpus_weight(*nodemask)) { |
9c1cfda2 | 7409 | sd = &per_cpu(allnodes_domains, i); |
7c16ec58 | 7410 | SD_INIT(sd, ALLNODES); |
1d3504fc | 7411 | set_domain_attribute(sd, attr); |
9c1cfda2 | 7412 | sd->span = *cpu_map; |
7c16ec58 | 7413 | cpu_to_allnodes_group(i, cpu_map, &sd->groups, tmpmask); |
9c1cfda2 | 7414 | p = sd; |
6711cab4 | 7415 | sd_allnodes = 1; |
9c1cfda2 JH |
7416 | } else |
7417 | p = NULL; | |
7418 | ||
1da177e4 | 7419 | sd = &per_cpu(node_domains, i); |
7c16ec58 | 7420 | SD_INIT(sd, NODE); |
1d3504fc | 7421 | set_domain_attribute(sd, attr); |
4bdbaad3 | 7422 | sched_domain_node_span(cpu_to_node(i), &sd->span); |
9c1cfda2 | 7423 | sd->parent = p; |
1a848870 SS |
7424 | if (p) |
7425 | p->child = sd; | |
9c1cfda2 | 7426 | cpus_and(sd->span, sd->span, *cpu_map); |
1da177e4 LT |
7427 | #endif |
7428 | ||
7429 | p = sd; | |
7430 | sd = &per_cpu(phys_domains, i); | |
7c16ec58 | 7431 | SD_INIT(sd, CPU); |
1d3504fc | 7432 | set_domain_attribute(sd, attr); |
7c16ec58 | 7433 | sd->span = *nodemask; |
1da177e4 | 7434 | sd->parent = p; |
1a848870 SS |
7435 | if (p) |
7436 | p->child = sd; | |
7c16ec58 | 7437 | cpu_to_phys_group(i, cpu_map, &sd->groups, tmpmask); |
1da177e4 | 7438 | |
1e9f28fa SS |
7439 | #ifdef CONFIG_SCHED_MC |
7440 | p = sd; | |
7441 | sd = &per_cpu(core_domains, i); | |
7c16ec58 | 7442 | SD_INIT(sd, MC); |
1d3504fc | 7443 | set_domain_attribute(sd, attr); |
1e9f28fa SS |
7444 | sd->span = cpu_coregroup_map(i); |
7445 | cpus_and(sd->span, sd->span, *cpu_map); | |
7446 | sd->parent = p; | |
1a848870 | 7447 | p->child = sd; |
7c16ec58 | 7448 | cpu_to_core_group(i, cpu_map, &sd->groups, tmpmask); |
1e9f28fa SS |
7449 | #endif |
7450 | ||
1da177e4 LT |
7451 | #ifdef CONFIG_SCHED_SMT |
7452 | p = sd; | |
7453 | sd = &per_cpu(cpu_domains, i); | |
7c16ec58 | 7454 | SD_INIT(sd, SIBLING); |
1d3504fc | 7455 | set_domain_attribute(sd, attr); |
d5a7430d | 7456 | sd->span = per_cpu(cpu_sibling_map, i); |
1a20ff27 | 7457 | cpus_and(sd->span, sd->span, *cpu_map); |
1da177e4 | 7458 | sd->parent = p; |
1a848870 | 7459 | p->child = sd; |
7c16ec58 | 7460 | cpu_to_cpu_group(i, cpu_map, &sd->groups, tmpmask); |
1da177e4 LT |
7461 | #endif |
7462 | } | |
7463 | ||
7464 | #ifdef CONFIG_SCHED_SMT | |
7465 | /* Set up CPU (sibling) groups */ | |
abcd083a | 7466 | for_each_cpu(i, cpu_map) { |
7c16ec58 MT |
7467 | SCHED_CPUMASK_VAR(this_sibling_map, allmasks); |
7468 | SCHED_CPUMASK_VAR(send_covered, allmasks); | |
7469 | ||
7470 | *this_sibling_map = per_cpu(cpu_sibling_map, i); | |
7471 | cpus_and(*this_sibling_map, *this_sibling_map, *cpu_map); | |
7472 | if (i != first_cpu(*this_sibling_map)) | |
1da177e4 LT |
7473 | continue; |
7474 | ||
dd41f596 | 7475 | init_sched_build_groups(this_sibling_map, cpu_map, |
7c16ec58 MT |
7476 | &cpu_to_cpu_group, |
7477 | send_covered, tmpmask); | |
1da177e4 LT |
7478 | } |
7479 | #endif | |
7480 | ||
1e9f28fa SS |
7481 | #ifdef CONFIG_SCHED_MC |
7482 | /* Set up multi-core groups */ | |
abcd083a | 7483 | for_each_cpu(i, cpu_map) { |
7c16ec58 MT |
7484 | SCHED_CPUMASK_VAR(this_core_map, allmasks); |
7485 | SCHED_CPUMASK_VAR(send_covered, allmasks); | |
7486 | ||
7487 | *this_core_map = cpu_coregroup_map(i); | |
7488 | cpus_and(*this_core_map, *this_core_map, *cpu_map); | |
7489 | if (i != first_cpu(*this_core_map)) | |
1e9f28fa | 7490 | continue; |
7c16ec58 | 7491 | |
dd41f596 | 7492 | init_sched_build_groups(this_core_map, cpu_map, |
7c16ec58 MT |
7493 | &cpu_to_core_group, |
7494 | send_covered, tmpmask); | |
1e9f28fa SS |
7495 | } |
7496 | #endif | |
7497 | ||
1da177e4 | 7498 | /* Set up physical groups */ |
076ac2af | 7499 | for (i = 0; i < nr_node_ids; i++) { |
7c16ec58 MT |
7500 | SCHED_CPUMASK_VAR(nodemask, allmasks); |
7501 | SCHED_CPUMASK_VAR(send_covered, allmasks); | |
1da177e4 | 7502 | |
7c16ec58 MT |
7503 | *nodemask = node_to_cpumask(i); |
7504 | cpus_and(*nodemask, *nodemask, *cpu_map); | |
7505 | if (cpus_empty(*nodemask)) | |
1da177e4 LT |
7506 | continue; |
7507 | ||
7c16ec58 MT |
7508 | init_sched_build_groups(nodemask, cpu_map, |
7509 | &cpu_to_phys_group, | |
7510 | send_covered, tmpmask); | |
1da177e4 LT |
7511 | } |
7512 | ||
7513 | #ifdef CONFIG_NUMA | |
7514 | /* Set up node groups */ | |
7c16ec58 MT |
7515 | if (sd_allnodes) { |
7516 | SCHED_CPUMASK_VAR(send_covered, allmasks); | |
7517 | ||
7518 | init_sched_build_groups(cpu_map, cpu_map, | |
7519 | &cpu_to_allnodes_group, | |
7520 | send_covered, tmpmask); | |
7521 | } | |
9c1cfda2 | 7522 | |
076ac2af | 7523 | for (i = 0; i < nr_node_ids; i++) { |
9c1cfda2 JH |
7524 | /* Set up node groups */ |
7525 | struct sched_group *sg, *prev; | |
7c16ec58 MT |
7526 | SCHED_CPUMASK_VAR(nodemask, allmasks); |
7527 | SCHED_CPUMASK_VAR(domainspan, allmasks); | |
7528 | SCHED_CPUMASK_VAR(covered, allmasks); | |
9c1cfda2 JH |
7529 | int j; |
7530 | ||
7c16ec58 MT |
7531 | *nodemask = node_to_cpumask(i); |
7532 | cpus_clear(*covered); | |
7533 | ||
7534 | cpus_and(*nodemask, *nodemask, *cpu_map); | |
7535 | if (cpus_empty(*nodemask)) { | |
d1b55138 | 7536 | sched_group_nodes[i] = NULL; |
9c1cfda2 | 7537 | continue; |
d1b55138 | 7538 | } |
9c1cfda2 | 7539 | |
4bdbaad3 | 7540 | sched_domain_node_span(i, domainspan); |
7c16ec58 | 7541 | cpus_and(*domainspan, *domainspan, *cpu_map); |
9c1cfda2 | 7542 | |
15f0b676 | 7543 | sg = kmalloc_node(sizeof(struct sched_group), GFP_KERNEL, i); |
51888ca2 SV |
7544 | if (!sg) { |
7545 | printk(KERN_WARNING "Can not alloc domain group for " | |
7546 | "node %d\n", i); | |
7547 | goto error; | |
7548 | } | |
9c1cfda2 | 7549 | sched_group_nodes[i] = sg; |
abcd083a | 7550 | for_each_cpu(j, nodemask) { |
9c1cfda2 | 7551 | struct sched_domain *sd; |
9761eea8 | 7552 | |
9c1cfda2 JH |
7553 | sd = &per_cpu(node_domains, j); |
7554 | sd->groups = sg; | |
9c1cfda2 | 7555 | } |
5517d86b | 7556 | sg->__cpu_power = 0; |
7c16ec58 | 7557 | sg->cpumask = *nodemask; |
51888ca2 | 7558 | sg->next = sg; |
7c16ec58 | 7559 | cpus_or(*covered, *covered, *nodemask); |
9c1cfda2 JH |
7560 | prev = sg; |
7561 | ||
076ac2af | 7562 | for (j = 0; j < nr_node_ids; j++) { |
7c16ec58 | 7563 | SCHED_CPUMASK_VAR(notcovered, allmasks); |
076ac2af | 7564 | int n = (i + j) % nr_node_ids; |
c5f59f08 | 7565 | node_to_cpumask_ptr(pnodemask, n); |
9c1cfda2 | 7566 | |
7c16ec58 MT |
7567 | cpus_complement(*notcovered, *covered); |
7568 | cpus_and(*tmpmask, *notcovered, *cpu_map); | |
7569 | cpus_and(*tmpmask, *tmpmask, *domainspan); | |
7570 | if (cpus_empty(*tmpmask)) | |
9c1cfda2 JH |
7571 | break; |
7572 | ||
7c16ec58 MT |
7573 | cpus_and(*tmpmask, *tmpmask, *pnodemask); |
7574 | if (cpus_empty(*tmpmask)) | |
9c1cfda2 JH |
7575 | continue; |
7576 | ||
15f0b676 SV |
7577 | sg = kmalloc_node(sizeof(struct sched_group), |
7578 | GFP_KERNEL, i); | |
9c1cfda2 JH |
7579 | if (!sg) { |
7580 | printk(KERN_WARNING | |
7581 | "Can not alloc domain group for node %d\n", j); | |
51888ca2 | 7582 | goto error; |
9c1cfda2 | 7583 | } |
5517d86b | 7584 | sg->__cpu_power = 0; |
7c16ec58 | 7585 | sg->cpumask = *tmpmask; |
51888ca2 | 7586 | sg->next = prev->next; |
7c16ec58 | 7587 | cpus_or(*covered, *covered, *tmpmask); |
9c1cfda2 JH |
7588 | prev->next = sg; |
7589 | prev = sg; | |
7590 | } | |
9c1cfda2 | 7591 | } |
1da177e4 LT |
7592 | #endif |
7593 | ||
7594 | /* Calculate CPU power for physical packages and nodes */ | |
5c45bf27 | 7595 | #ifdef CONFIG_SCHED_SMT |
abcd083a | 7596 | for_each_cpu(i, cpu_map) { |
dd41f596 IM |
7597 | struct sched_domain *sd = &per_cpu(cpu_domains, i); |
7598 | ||
89c4710e | 7599 | init_sched_groups_power(i, sd); |
5c45bf27 | 7600 | } |
1da177e4 | 7601 | #endif |
1e9f28fa | 7602 | #ifdef CONFIG_SCHED_MC |
abcd083a | 7603 | for_each_cpu(i, cpu_map) { |
dd41f596 IM |
7604 | struct sched_domain *sd = &per_cpu(core_domains, i); |
7605 | ||
89c4710e | 7606 | init_sched_groups_power(i, sd); |
5c45bf27 SS |
7607 | } |
7608 | #endif | |
1e9f28fa | 7609 | |
abcd083a | 7610 | for_each_cpu(i, cpu_map) { |
dd41f596 IM |
7611 | struct sched_domain *sd = &per_cpu(phys_domains, i); |
7612 | ||
89c4710e | 7613 | init_sched_groups_power(i, sd); |
1da177e4 LT |
7614 | } |
7615 | ||
9c1cfda2 | 7616 | #ifdef CONFIG_NUMA |
076ac2af | 7617 | for (i = 0; i < nr_node_ids; i++) |
08069033 | 7618 | init_numa_sched_groups_power(sched_group_nodes[i]); |
9c1cfda2 | 7619 | |
6711cab4 SS |
7620 | if (sd_allnodes) { |
7621 | struct sched_group *sg; | |
f712c0c7 | 7622 | |
7c16ec58 MT |
7623 | cpu_to_allnodes_group(first_cpu(*cpu_map), cpu_map, &sg, |
7624 | tmpmask); | |
f712c0c7 SS |
7625 | init_numa_sched_groups_power(sg); |
7626 | } | |
9c1cfda2 JH |
7627 | #endif |
7628 | ||
1da177e4 | 7629 | /* Attach the domains */ |
abcd083a | 7630 | for_each_cpu(i, cpu_map) { |
1da177e4 LT |
7631 | struct sched_domain *sd; |
7632 | #ifdef CONFIG_SCHED_SMT | |
7633 | sd = &per_cpu(cpu_domains, i); | |
1e9f28fa SS |
7634 | #elif defined(CONFIG_SCHED_MC) |
7635 | sd = &per_cpu(core_domains, i); | |
1da177e4 LT |
7636 | #else |
7637 | sd = &per_cpu(phys_domains, i); | |
7638 | #endif | |
57d885fe | 7639 | cpu_attach_domain(sd, rd, i); |
1da177e4 | 7640 | } |
51888ca2 | 7641 | |
6d21cd62 | 7642 | sched_cpumask_free(allmasks); |
51888ca2 SV |
7643 | return 0; |
7644 | ||
a616058b | 7645 | #ifdef CONFIG_NUMA |
51888ca2 | 7646 | error: |
7c16ec58 | 7647 | free_sched_groups(cpu_map, tmpmask); |
6d21cd62 | 7648 | sched_cpumask_free(allmasks); |
ca3273f9 | 7649 | kfree(rd); |
51888ca2 | 7650 | return -ENOMEM; |
a616058b | 7651 | #endif |
1da177e4 | 7652 | } |
029190c5 | 7653 | |
1d3504fc HS |
7654 | static int build_sched_domains(const cpumask_t *cpu_map) |
7655 | { | |
7656 | return __build_sched_domains(cpu_map, NULL); | |
7657 | } | |
7658 | ||
029190c5 PJ |
7659 | static cpumask_t *doms_cur; /* current sched domains */ |
7660 | static int ndoms_cur; /* number of sched domains in 'doms_cur' */ | |
4285f594 IM |
7661 | static struct sched_domain_attr *dattr_cur; |
7662 | /* attribues of custom domains in 'doms_cur' */ | |
029190c5 PJ |
7663 | |
7664 | /* | |
7665 | * Special case: If a kmalloc of a doms_cur partition (array of | |
7666 | * cpumask_t) fails, then fallback to a single sched domain, | |
7667 | * as determined by the single cpumask_t fallback_doms. | |
7668 | */ | |
7669 | static cpumask_t fallback_doms; | |
7670 | ||
22e52b07 HC |
7671 | void __attribute__((weak)) arch_update_cpu_topology(void) |
7672 | { | |
7673 | } | |
7674 | ||
1a20ff27 | 7675 | /* |
41a2d6cf | 7676 | * Set up scheduler domains and groups. Callers must hold the hotplug lock. |
029190c5 PJ |
7677 | * For now this just excludes isolated cpus, but could be used to |
7678 | * exclude other special cases in the future. | |
1a20ff27 | 7679 | */ |
51888ca2 | 7680 | static int arch_init_sched_domains(const cpumask_t *cpu_map) |
1a20ff27 | 7681 | { |
7378547f MM |
7682 | int err; |
7683 | ||
22e52b07 | 7684 | arch_update_cpu_topology(); |
029190c5 PJ |
7685 | ndoms_cur = 1; |
7686 | doms_cur = kmalloc(sizeof(cpumask_t), GFP_KERNEL); | |
7687 | if (!doms_cur) | |
7688 | doms_cur = &fallback_doms; | |
7689 | cpus_andnot(*doms_cur, *cpu_map, cpu_isolated_map); | |
1d3504fc | 7690 | dattr_cur = NULL; |
7378547f | 7691 | err = build_sched_domains(doms_cur); |
6382bc90 | 7692 | register_sched_domain_sysctl(); |
7378547f MM |
7693 | |
7694 | return err; | |
1a20ff27 DG |
7695 | } |
7696 | ||
7c16ec58 MT |
7697 | static void arch_destroy_sched_domains(const cpumask_t *cpu_map, |
7698 | cpumask_t *tmpmask) | |
1da177e4 | 7699 | { |
7c16ec58 | 7700 | free_sched_groups(cpu_map, tmpmask); |
9c1cfda2 | 7701 | } |
1da177e4 | 7702 | |
1a20ff27 DG |
7703 | /* |
7704 | * Detach sched domains from a group of cpus specified in cpu_map | |
7705 | * These cpus will now be attached to the NULL domain | |
7706 | */ | |
858119e1 | 7707 | static void detach_destroy_domains(const cpumask_t *cpu_map) |
1a20ff27 | 7708 | { |
7c16ec58 | 7709 | cpumask_t tmpmask; |
1a20ff27 DG |
7710 | int i; |
7711 | ||
abcd083a | 7712 | for_each_cpu(i, cpu_map) |
57d885fe | 7713 | cpu_attach_domain(NULL, &def_root_domain, i); |
1a20ff27 | 7714 | synchronize_sched(); |
7c16ec58 | 7715 | arch_destroy_sched_domains(cpu_map, &tmpmask); |
1a20ff27 DG |
7716 | } |
7717 | ||
1d3504fc HS |
7718 | /* handle null as "default" */ |
7719 | static int dattrs_equal(struct sched_domain_attr *cur, int idx_cur, | |
7720 | struct sched_domain_attr *new, int idx_new) | |
7721 | { | |
7722 | struct sched_domain_attr tmp; | |
7723 | ||
7724 | /* fast path */ | |
7725 | if (!new && !cur) | |
7726 | return 1; | |
7727 | ||
7728 | tmp = SD_ATTR_INIT; | |
7729 | return !memcmp(cur ? (cur + idx_cur) : &tmp, | |
7730 | new ? (new + idx_new) : &tmp, | |
7731 | sizeof(struct sched_domain_attr)); | |
7732 | } | |
7733 | ||
029190c5 PJ |
7734 | /* |
7735 | * Partition sched domains as specified by the 'ndoms_new' | |
41a2d6cf | 7736 | * cpumasks in the array doms_new[] of cpumasks. This compares |
029190c5 PJ |
7737 | * doms_new[] to the current sched domain partitioning, doms_cur[]. |
7738 | * It destroys each deleted domain and builds each new domain. | |
7739 | * | |
7740 | * 'doms_new' is an array of cpumask_t's of length 'ndoms_new'. | |
41a2d6cf IM |
7741 | * The masks don't intersect (don't overlap.) We should setup one |
7742 | * sched domain for each mask. CPUs not in any of the cpumasks will | |
7743 | * not be load balanced. If the same cpumask appears both in the | |
029190c5 PJ |
7744 | * current 'doms_cur' domains and in the new 'doms_new', we can leave |
7745 | * it as it is. | |
7746 | * | |
41a2d6cf IM |
7747 | * The passed in 'doms_new' should be kmalloc'd. This routine takes |
7748 | * ownership of it and will kfree it when done with it. If the caller | |
700018e0 LZ |
7749 | * failed the kmalloc call, then it can pass in doms_new == NULL && |
7750 | * ndoms_new == 1, and partition_sched_domains() will fallback to | |
7751 | * the single partition 'fallback_doms', it also forces the domains | |
7752 | * to be rebuilt. | |
029190c5 | 7753 | * |
700018e0 LZ |
7754 | * If doms_new == NULL it will be replaced with cpu_online_map. |
7755 | * ndoms_new == 0 is a special case for destroying existing domains, | |
7756 | * and it will not create the default domain. | |
dfb512ec | 7757 | * |
029190c5 PJ |
7758 | * Call with hotplug lock held |
7759 | */ | |
1d3504fc HS |
7760 | void partition_sched_domains(int ndoms_new, cpumask_t *doms_new, |
7761 | struct sched_domain_attr *dattr_new) | |
029190c5 | 7762 | { |
dfb512ec | 7763 | int i, j, n; |
029190c5 | 7764 | |
712555ee | 7765 | mutex_lock(&sched_domains_mutex); |
a1835615 | 7766 | |
7378547f MM |
7767 | /* always unregister in case we don't destroy any domains */ |
7768 | unregister_sched_domain_sysctl(); | |
7769 | ||
dfb512ec | 7770 | n = doms_new ? ndoms_new : 0; |
029190c5 PJ |
7771 | |
7772 | /* Destroy deleted domains */ | |
7773 | for (i = 0; i < ndoms_cur; i++) { | |
dfb512ec | 7774 | for (j = 0; j < n; j++) { |
1d3504fc HS |
7775 | if (cpus_equal(doms_cur[i], doms_new[j]) |
7776 | && dattrs_equal(dattr_cur, i, dattr_new, j)) | |
029190c5 PJ |
7777 | goto match1; |
7778 | } | |
7779 | /* no match - a current sched domain not in new doms_new[] */ | |
7780 | detach_destroy_domains(doms_cur + i); | |
7781 | match1: | |
7782 | ; | |
7783 | } | |
7784 | ||
e761b772 MK |
7785 | if (doms_new == NULL) { |
7786 | ndoms_cur = 0; | |
e761b772 MK |
7787 | doms_new = &fallback_doms; |
7788 | cpus_andnot(doms_new[0], cpu_online_map, cpu_isolated_map); | |
faa2f98f | 7789 | WARN_ON_ONCE(dattr_new); |
e761b772 MK |
7790 | } |
7791 | ||
029190c5 PJ |
7792 | /* Build new domains */ |
7793 | for (i = 0; i < ndoms_new; i++) { | |
7794 | for (j = 0; j < ndoms_cur; j++) { | |
1d3504fc HS |
7795 | if (cpus_equal(doms_new[i], doms_cur[j]) |
7796 | && dattrs_equal(dattr_new, i, dattr_cur, j)) | |
029190c5 PJ |
7797 | goto match2; |
7798 | } | |
7799 | /* no match - add a new doms_new */ | |
1d3504fc HS |
7800 | __build_sched_domains(doms_new + i, |
7801 | dattr_new ? dattr_new + i : NULL); | |
029190c5 PJ |
7802 | match2: |
7803 | ; | |
7804 | } | |
7805 | ||
7806 | /* Remember the new sched domains */ | |
7807 | if (doms_cur != &fallback_doms) | |
7808 | kfree(doms_cur); | |
1d3504fc | 7809 | kfree(dattr_cur); /* kfree(NULL) is safe */ |
029190c5 | 7810 | doms_cur = doms_new; |
1d3504fc | 7811 | dattr_cur = dattr_new; |
029190c5 | 7812 | ndoms_cur = ndoms_new; |
7378547f MM |
7813 | |
7814 | register_sched_domain_sysctl(); | |
a1835615 | 7815 | |
712555ee | 7816 | mutex_unlock(&sched_domains_mutex); |
029190c5 PJ |
7817 | } |
7818 | ||
5c45bf27 | 7819 | #if defined(CONFIG_SCHED_MC) || defined(CONFIG_SCHED_SMT) |
9aefd0ab | 7820 | int arch_reinit_sched_domains(void) |
5c45bf27 | 7821 | { |
95402b38 | 7822 | get_online_cpus(); |
dfb512ec MK |
7823 | |
7824 | /* Destroy domains first to force the rebuild */ | |
7825 | partition_sched_domains(0, NULL, NULL); | |
7826 | ||
e761b772 | 7827 | rebuild_sched_domains(); |
95402b38 | 7828 | put_online_cpus(); |
dfb512ec | 7829 | |
e761b772 | 7830 | return 0; |
5c45bf27 SS |
7831 | } |
7832 | ||
7833 | static ssize_t sched_power_savings_store(const char *buf, size_t count, int smt) | |
7834 | { | |
7835 | int ret; | |
7836 | ||
7837 | if (buf[0] != '0' && buf[0] != '1') | |
7838 | return -EINVAL; | |
7839 | ||
7840 | if (smt) | |
7841 | sched_smt_power_savings = (buf[0] == '1'); | |
7842 | else | |
7843 | sched_mc_power_savings = (buf[0] == '1'); | |
7844 | ||
7845 | ret = arch_reinit_sched_domains(); | |
7846 | ||
7847 | return ret ? ret : count; | |
7848 | } | |
7849 | ||
5c45bf27 | 7850 | #ifdef CONFIG_SCHED_MC |
f718cd4a AK |
7851 | static ssize_t sched_mc_power_savings_show(struct sysdev_class *class, |
7852 | char *page) | |
5c45bf27 SS |
7853 | { |
7854 | return sprintf(page, "%u\n", sched_mc_power_savings); | |
7855 | } | |
f718cd4a | 7856 | static ssize_t sched_mc_power_savings_store(struct sysdev_class *class, |
48f24c4d | 7857 | const char *buf, size_t count) |
5c45bf27 SS |
7858 | { |
7859 | return sched_power_savings_store(buf, count, 0); | |
7860 | } | |
f718cd4a AK |
7861 | static SYSDEV_CLASS_ATTR(sched_mc_power_savings, 0644, |
7862 | sched_mc_power_savings_show, | |
7863 | sched_mc_power_savings_store); | |
5c45bf27 SS |
7864 | #endif |
7865 | ||
7866 | #ifdef CONFIG_SCHED_SMT | |
f718cd4a AK |
7867 | static ssize_t sched_smt_power_savings_show(struct sysdev_class *dev, |
7868 | char *page) | |
5c45bf27 SS |
7869 | { |
7870 | return sprintf(page, "%u\n", sched_smt_power_savings); | |
7871 | } | |
f718cd4a | 7872 | static ssize_t sched_smt_power_savings_store(struct sysdev_class *dev, |
48f24c4d | 7873 | const char *buf, size_t count) |
5c45bf27 SS |
7874 | { |
7875 | return sched_power_savings_store(buf, count, 1); | |
7876 | } | |
f718cd4a AK |
7877 | static SYSDEV_CLASS_ATTR(sched_smt_power_savings, 0644, |
7878 | sched_smt_power_savings_show, | |
6707de00 AB |
7879 | sched_smt_power_savings_store); |
7880 | #endif | |
7881 | ||
7882 | int sched_create_sysfs_power_savings_entries(struct sysdev_class *cls) | |
7883 | { | |
7884 | int err = 0; | |
7885 | ||
7886 | #ifdef CONFIG_SCHED_SMT | |
7887 | if (smt_capable()) | |
7888 | err = sysfs_create_file(&cls->kset.kobj, | |
7889 | &attr_sched_smt_power_savings.attr); | |
7890 | #endif | |
7891 | #ifdef CONFIG_SCHED_MC | |
7892 | if (!err && mc_capable()) | |
7893 | err = sysfs_create_file(&cls->kset.kobj, | |
7894 | &attr_sched_mc_power_savings.attr); | |
7895 | #endif | |
7896 | return err; | |
7897 | } | |
6d6bc0ad | 7898 | #endif /* CONFIG_SCHED_MC || CONFIG_SCHED_SMT */ |
5c45bf27 | 7899 | |
e761b772 | 7900 | #ifndef CONFIG_CPUSETS |
1da177e4 | 7901 | /* |
e761b772 MK |
7902 | * Add online and remove offline CPUs from the scheduler domains. |
7903 | * When cpusets are enabled they take over this function. | |
1da177e4 LT |
7904 | */ |
7905 | static int update_sched_domains(struct notifier_block *nfb, | |
7906 | unsigned long action, void *hcpu) | |
e761b772 MK |
7907 | { |
7908 | switch (action) { | |
7909 | case CPU_ONLINE: | |
7910 | case CPU_ONLINE_FROZEN: | |
7911 | case CPU_DEAD: | |
7912 | case CPU_DEAD_FROZEN: | |
dfb512ec | 7913 | partition_sched_domains(1, NULL, NULL); |
e761b772 MK |
7914 | return NOTIFY_OK; |
7915 | ||
7916 | default: | |
7917 | return NOTIFY_DONE; | |
7918 | } | |
7919 | } | |
7920 | #endif | |
7921 | ||
7922 | static int update_runtime(struct notifier_block *nfb, | |
7923 | unsigned long action, void *hcpu) | |
1da177e4 | 7924 | { |
7def2be1 PZ |
7925 | int cpu = (int)(long)hcpu; |
7926 | ||
1da177e4 | 7927 | switch (action) { |
1da177e4 | 7928 | case CPU_DOWN_PREPARE: |
8bb78442 | 7929 | case CPU_DOWN_PREPARE_FROZEN: |
7def2be1 | 7930 | disable_runtime(cpu_rq(cpu)); |
1da177e4 LT |
7931 | return NOTIFY_OK; |
7932 | ||
1da177e4 | 7933 | case CPU_DOWN_FAILED: |
8bb78442 | 7934 | case CPU_DOWN_FAILED_FROZEN: |
1da177e4 | 7935 | case CPU_ONLINE: |
8bb78442 | 7936 | case CPU_ONLINE_FROZEN: |
7def2be1 | 7937 | enable_runtime(cpu_rq(cpu)); |
e761b772 MK |
7938 | return NOTIFY_OK; |
7939 | ||
1da177e4 LT |
7940 | default: |
7941 | return NOTIFY_DONE; | |
7942 | } | |
1da177e4 | 7943 | } |
1da177e4 LT |
7944 | |
7945 | void __init sched_init_smp(void) | |
7946 | { | |
5c1e1767 NP |
7947 | cpumask_t non_isolated_cpus; |
7948 | ||
434d53b0 MT |
7949 | #if defined(CONFIG_NUMA) |
7950 | sched_group_nodes_bycpu = kzalloc(nr_cpu_ids * sizeof(void **), | |
7951 | GFP_KERNEL); | |
7952 | BUG_ON(sched_group_nodes_bycpu == NULL); | |
7953 | #endif | |
95402b38 | 7954 | get_online_cpus(); |
712555ee | 7955 | mutex_lock(&sched_domains_mutex); |
1a20ff27 | 7956 | arch_init_sched_domains(&cpu_online_map); |
e5e5673f | 7957 | cpus_andnot(non_isolated_cpus, cpu_possible_map, cpu_isolated_map); |
5c1e1767 NP |
7958 | if (cpus_empty(non_isolated_cpus)) |
7959 | cpu_set(smp_processor_id(), non_isolated_cpus); | |
712555ee | 7960 | mutex_unlock(&sched_domains_mutex); |
95402b38 | 7961 | put_online_cpus(); |
e761b772 MK |
7962 | |
7963 | #ifndef CONFIG_CPUSETS | |
1da177e4 LT |
7964 | /* XXX: Theoretical race here - CPU may be hotplugged now */ |
7965 | hotcpu_notifier(update_sched_domains, 0); | |
e761b772 MK |
7966 | #endif |
7967 | ||
7968 | /* RT runtime code needs to handle some hotplug events */ | |
7969 | hotcpu_notifier(update_runtime, 0); | |
7970 | ||
b328ca18 | 7971 | init_hrtick(); |
5c1e1767 NP |
7972 | |
7973 | /* Move init over to a non-isolated CPU */ | |
7c16ec58 | 7974 | if (set_cpus_allowed_ptr(current, &non_isolated_cpus) < 0) |
5c1e1767 | 7975 | BUG(); |
19978ca6 | 7976 | sched_init_granularity(); |
1da177e4 LT |
7977 | } |
7978 | #else | |
7979 | void __init sched_init_smp(void) | |
7980 | { | |
19978ca6 | 7981 | sched_init_granularity(); |
1da177e4 LT |
7982 | } |
7983 | #endif /* CONFIG_SMP */ | |
7984 | ||
7985 | int in_sched_functions(unsigned long addr) | |
7986 | { | |
1da177e4 LT |
7987 | return in_lock_functions(addr) || |
7988 | (addr >= (unsigned long)__sched_text_start | |
7989 | && addr < (unsigned long)__sched_text_end); | |
7990 | } | |
7991 | ||
a9957449 | 7992 | static void init_cfs_rq(struct cfs_rq *cfs_rq, struct rq *rq) |
dd41f596 IM |
7993 | { |
7994 | cfs_rq->tasks_timeline = RB_ROOT; | |
4a55bd5e | 7995 | INIT_LIST_HEAD(&cfs_rq->tasks); |
dd41f596 IM |
7996 | #ifdef CONFIG_FAIR_GROUP_SCHED |
7997 | cfs_rq->rq = rq; | |
7998 | #endif | |
67e9fb2a | 7999 | cfs_rq->min_vruntime = (u64)(-(1LL << 20)); |
dd41f596 IM |
8000 | } |
8001 | ||
fa85ae24 PZ |
8002 | static void init_rt_rq(struct rt_rq *rt_rq, struct rq *rq) |
8003 | { | |
8004 | struct rt_prio_array *array; | |
8005 | int i; | |
8006 | ||
8007 | array = &rt_rq->active; | |
8008 | for (i = 0; i < MAX_RT_PRIO; i++) { | |
8009 | INIT_LIST_HEAD(array->queue + i); | |
8010 | __clear_bit(i, array->bitmap); | |
8011 | } | |
8012 | /* delimiter for bitsearch: */ | |
8013 | __set_bit(MAX_RT_PRIO, array->bitmap); | |
8014 | ||
052f1dc7 | 8015 | #if defined CONFIG_SMP || defined CONFIG_RT_GROUP_SCHED |
48d5e258 PZ |
8016 | rt_rq->highest_prio = MAX_RT_PRIO; |
8017 | #endif | |
fa85ae24 PZ |
8018 | #ifdef CONFIG_SMP |
8019 | rt_rq->rt_nr_migratory = 0; | |
fa85ae24 PZ |
8020 | rt_rq->overloaded = 0; |
8021 | #endif | |
8022 | ||
8023 | rt_rq->rt_time = 0; | |
8024 | rt_rq->rt_throttled = 0; | |
ac086bc2 PZ |
8025 | rt_rq->rt_runtime = 0; |
8026 | spin_lock_init(&rt_rq->rt_runtime_lock); | |
6f505b16 | 8027 | |
052f1dc7 | 8028 | #ifdef CONFIG_RT_GROUP_SCHED |
23b0fdfc | 8029 | rt_rq->rt_nr_boosted = 0; |
6f505b16 PZ |
8030 | rt_rq->rq = rq; |
8031 | #endif | |
fa85ae24 PZ |
8032 | } |
8033 | ||
6f505b16 | 8034 | #ifdef CONFIG_FAIR_GROUP_SCHED |
ec7dc8ac DG |
8035 | static void init_tg_cfs_entry(struct task_group *tg, struct cfs_rq *cfs_rq, |
8036 | struct sched_entity *se, int cpu, int add, | |
8037 | struct sched_entity *parent) | |
6f505b16 | 8038 | { |
ec7dc8ac | 8039 | struct rq *rq = cpu_rq(cpu); |
6f505b16 PZ |
8040 | tg->cfs_rq[cpu] = cfs_rq; |
8041 | init_cfs_rq(cfs_rq, rq); | |
8042 | cfs_rq->tg = tg; | |
8043 | if (add) | |
8044 | list_add(&cfs_rq->leaf_cfs_rq_list, &rq->leaf_cfs_rq_list); | |
8045 | ||
8046 | tg->se[cpu] = se; | |
354d60c2 DG |
8047 | /* se could be NULL for init_task_group */ |
8048 | if (!se) | |
8049 | return; | |
8050 | ||
ec7dc8ac DG |
8051 | if (!parent) |
8052 | se->cfs_rq = &rq->cfs; | |
8053 | else | |
8054 | se->cfs_rq = parent->my_q; | |
8055 | ||
6f505b16 PZ |
8056 | se->my_q = cfs_rq; |
8057 | se->load.weight = tg->shares; | |
e05510d0 | 8058 | se->load.inv_weight = 0; |
ec7dc8ac | 8059 | se->parent = parent; |
6f505b16 | 8060 | } |
052f1dc7 | 8061 | #endif |
6f505b16 | 8062 | |
052f1dc7 | 8063 | #ifdef CONFIG_RT_GROUP_SCHED |
ec7dc8ac DG |
8064 | static void init_tg_rt_entry(struct task_group *tg, struct rt_rq *rt_rq, |
8065 | struct sched_rt_entity *rt_se, int cpu, int add, | |
8066 | struct sched_rt_entity *parent) | |
6f505b16 | 8067 | { |
ec7dc8ac DG |
8068 | struct rq *rq = cpu_rq(cpu); |
8069 | ||
6f505b16 PZ |
8070 | tg->rt_rq[cpu] = rt_rq; |
8071 | init_rt_rq(rt_rq, rq); | |
8072 | rt_rq->tg = tg; | |
8073 | rt_rq->rt_se = rt_se; | |
ac086bc2 | 8074 | rt_rq->rt_runtime = tg->rt_bandwidth.rt_runtime; |
6f505b16 PZ |
8075 | if (add) |
8076 | list_add(&rt_rq->leaf_rt_rq_list, &rq->leaf_rt_rq_list); | |
8077 | ||
8078 | tg->rt_se[cpu] = rt_se; | |
354d60c2 DG |
8079 | if (!rt_se) |
8080 | return; | |
8081 | ||
ec7dc8ac DG |
8082 | if (!parent) |
8083 | rt_se->rt_rq = &rq->rt; | |
8084 | else | |
8085 | rt_se->rt_rq = parent->my_q; | |
8086 | ||
6f505b16 | 8087 | rt_se->my_q = rt_rq; |
ec7dc8ac | 8088 | rt_se->parent = parent; |
6f505b16 PZ |
8089 | INIT_LIST_HEAD(&rt_se->run_list); |
8090 | } | |
8091 | #endif | |
8092 | ||
1da177e4 LT |
8093 | void __init sched_init(void) |
8094 | { | |
dd41f596 | 8095 | int i, j; |
434d53b0 MT |
8096 | unsigned long alloc_size = 0, ptr; |
8097 | ||
8098 | #ifdef CONFIG_FAIR_GROUP_SCHED | |
8099 | alloc_size += 2 * nr_cpu_ids * sizeof(void **); | |
8100 | #endif | |
8101 | #ifdef CONFIG_RT_GROUP_SCHED | |
8102 | alloc_size += 2 * nr_cpu_ids * sizeof(void **); | |
eff766a6 PZ |
8103 | #endif |
8104 | #ifdef CONFIG_USER_SCHED | |
8105 | alloc_size *= 2; | |
434d53b0 MT |
8106 | #endif |
8107 | /* | |
8108 | * As sched_init() is called before page_alloc is setup, | |
8109 | * we use alloc_bootmem(). | |
8110 | */ | |
8111 | if (alloc_size) { | |
5a9d3225 | 8112 | ptr = (unsigned long)alloc_bootmem(alloc_size); |
434d53b0 MT |
8113 | |
8114 | #ifdef CONFIG_FAIR_GROUP_SCHED | |
8115 | init_task_group.se = (struct sched_entity **)ptr; | |
8116 | ptr += nr_cpu_ids * sizeof(void **); | |
8117 | ||
8118 | init_task_group.cfs_rq = (struct cfs_rq **)ptr; | |
8119 | ptr += nr_cpu_ids * sizeof(void **); | |
eff766a6 PZ |
8120 | |
8121 | #ifdef CONFIG_USER_SCHED | |
8122 | root_task_group.se = (struct sched_entity **)ptr; | |
8123 | ptr += nr_cpu_ids * sizeof(void **); | |
8124 | ||
8125 | root_task_group.cfs_rq = (struct cfs_rq **)ptr; | |
8126 | ptr += nr_cpu_ids * sizeof(void **); | |
6d6bc0ad DG |
8127 | #endif /* CONFIG_USER_SCHED */ |
8128 | #endif /* CONFIG_FAIR_GROUP_SCHED */ | |
434d53b0 MT |
8129 | #ifdef CONFIG_RT_GROUP_SCHED |
8130 | init_task_group.rt_se = (struct sched_rt_entity **)ptr; | |
8131 | ptr += nr_cpu_ids * sizeof(void **); | |
8132 | ||
8133 | init_task_group.rt_rq = (struct rt_rq **)ptr; | |
eff766a6 PZ |
8134 | ptr += nr_cpu_ids * sizeof(void **); |
8135 | ||
8136 | #ifdef CONFIG_USER_SCHED | |
8137 | root_task_group.rt_se = (struct sched_rt_entity **)ptr; | |
8138 | ptr += nr_cpu_ids * sizeof(void **); | |
8139 | ||
8140 | root_task_group.rt_rq = (struct rt_rq **)ptr; | |
8141 | ptr += nr_cpu_ids * sizeof(void **); | |
6d6bc0ad DG |
8142 | #endif /* CONFIG_USER_SCHED */ |
8143 | #endif /* CONFIG_RT_GROUP_SCHED */ | |
434d53b0 | 8144 | } |
dd41f596 | 8145 | |
57d885fe GH |
8146 | #ifdef CONFIG_SMP |
8147 | init_defrootdomain(); | |
8148 | #endif | |
8149 | ||
d0b27fa7 PZ |
8150 | init_rt_bandwidth(&def_rt_bandwidth, |
8151 | global_rt_period(), global_rt_runtime()); | |
8152 | ||
8153 | #ifdef CONFIG_RT_GROUP_SCHED | |
8154 | init_rt_bandwidth(&init_task_group.rt_bandwidth, | |
8155 | global_rt_period(), global_rt_runtime()); | |
eff766a6 PZ |
8156 | #ifdef CONFIG_USER_SCHED |
8157 | init_rt_bandwidth(&root_task_group.rt_bandwidth, | |
8158 | global_rt_period(), RUNTIME_INF); | |
6d6bc0ad DG |
8159 | #endif /* CONFIG_USER_SCHED */ |
8160 | #endif /* CONFIG_RT_GROUP_SCHED */ | |
d0b27fa7 | 8161 | |
052f1dc7 | 8162 | #ifdef CONFIG_GROUP_SCHED |
6f505b16 | 8163 | list_add(&init_task_group.list, &task_groups); |
f473aa5e PZ |
8164 | INIT_LIST_HEAD(&init_task_group.children); |
8165 | ||
8166 | #ifdef CONFIG_USER_SCHED | |
8167 | INIT_LIST_HEAD(&root_task_group.children); | |
8168 | init_task_group.parent = &root_task_group; | |
8169 | list_add(&init_task_group.siblings, &root_task_group.children); | |
6d6bc0ad DG |
8170 | #endif /* CONFIG_USER_SCHED */ |
8171 | #endif /* CONFIG_GROUP_SCHED */ | |
6f505b16 | 8172 | |
0a945022 | 8173 | for_each_possible_cpu(i) { |
70b97a7f | 8174 | struct rq *rq; |
1da177e4 LT |
8175 | |
8176 | rq = cpu_rq(i); | |
8177 | spin_lock_init(&rq->lock); | |
7897986b | 8178 | rq->nr_running = 0; |
dd41f596 | 8179 | init_cfs_rq(&rq->cfs, rq); |
6f505b16 | 8180 | init_rt_rq(&rq->rt, rq); |
dd41f596 | 8181 | #ifdef CONFIG_FAIR_GROUP_SCHED |
4cf86d77 | 8182 | init_task_group.shares = init_task_group_load; |
6f505b16 | 8183 | INIT_LIST_HEAD(&rq->leaf_cfs_rq_list); |
354d60c2 DG |
8184 | #ifdef CONFIG_CGROUP_SCHED |
8185 | /* | |
8186 | * How much cpu bandwidth does init_task_group get? | |
8187 | * | |
8188 | * In case of task-groups formed thr' the cgroup filesystem, it | |
8189 | * gets 100% of the cpu resources in the system. This overall | |
8190 | * system cpu resource is divided among the tasks of | |
8191 | * init_task_group and its child task-groups in a fair manner, | |
8192 | * based on each entity's (task or task-group's) weight | |
8193 | * (se->load.weight). | |
8194 | * | |
8195 | * In other words, if init_task_group has 10 tasks of weight | |
8196 | * 1024) and two child groups A0 and A1 (of weight 1024 each), | |
8197 | * then A0's share of the cpu resource is: | |
8198 | * | |
8199 | * A0's bandwidth = 1024 / (10*1024 + 1024 + 1024) = 8.33% | |
8200 | * | |
8201 | * We achieve this by letting init_task_group's tasks sit | |
8202 | * directly in rq->cfs (i.e init_task_group->se[] = NULL). | |
8203 | */ | |
ec7dc8ac | 8204 | init_tg_cfs_entry(&init_task_group, &rq->cfs, NULL, i, 1, NULL); |
354d60c2 | 8205 | #elif defined CONFIG_USER_SCHED |
eff766a6 PZ |
8206 | root_task_group.shares = NICE_0_LOAD; |
8207 | init_tg_cfs_entry(&root_task_group, &rq->cfs, NULL, i, 0, NULL); | |
354d60c2 DG |
8208 | /* |
8209 | * In case of task-groups formed thr' the user id of tasks, | |
8210 | * init_task_group represents tasks belonging to root user. | |
8211 | * Hence it forms a sibling of all subsequent groups formed. | |
8212 | * In this case, init_task_group gets only a fraction of overall | |
8213 | * system cpu resource, based on the weight assigned to root | |
8214 | * user's cpu share (INIT_TASK_GROUP_LOAD). This is accomplished | |
8215 | * by letting tasks of init_task_group sit in a separate cfs_rq | |
8216 | * (init_cfs_rq) and having one entity represent this group of | |
8217 | * tasks in rq->cfs (i.e init_task_group->se[] != NULL). | |
8218 | */ | |
ec7dc8ac | 8219 | init_tg_cfs_entry(&init_task_group, |
6f505b16 | 8220 | &per_cpu(init_cfs_rq, i), |
eff766a6 PZ |
8221 | &per_cpu(init_sched_entity, i), i, 1, |
8222 | root_task_group.se[i]); | |
6f505b16 | 8223 | |
052f1dc7 | 8224 | #endif |
354d60c2 DG |
8225 | #endif /* CONFIG_FAIR_GROUP_SCHED */ |
8226 | ||
8227 | rq->rt.rt_runtime = def_rt_bandwidth.rt_runtime; | |
052f1dc7 | 8228 | #ifdef CONFIG_RT_GROUP_SCHED |
6f505b16 | 8229 | INIT_LIST_HEAD(&rq->leaf_rt_rq_list); |
354d60c2 | 8230 | #ifdef CONFIG_CGROUP_SCHED |
ec7dc8ac | 8231 | init_tg_rt_entry(&init_task_group, &rq->rt, NULL, i, 1, NULL); |
354d60c2 | 8232 | #elif defined CONFIG_USER_SCHED |
eff766a6 | 8233 | init_tg_rt_entry(&root_task_group, &rq->rt, NULL, i, 0, NULL); |
ec7dc8ac | 8234 | init_tg_rt_entry(&init_task_group, |
6f505b16 | 8235 | &per_cpu(init_rt_rq, i), |
eff766a6 PZ |
8236 | &per_cpu(init_sched_rt_entity, i), i, 1, |
8237 | root_task_group.rt_se[i]); | |
354d60c2 | 8238 | #endif |
dd41f596 | 8239 | #endif |
1da177e4 | 8240 | |
dd41f596 IM |
8241 | for (j = 0; j < CPU_LOAD_IDX_MAX; j++) |
8242 | rq->cpu_load[j] = 0; | |
1da177e4 | 8243 | #ifdef CONFIG_SMP |
41c7ce9a | 8244 | rq->sd = NULL; |
57d885fe | 8245 | rq->rd = NULL; |
1da177e4 | 8246 | rq->active_balance = 0; |
dd41f596 | 8247 | rq->next_balance = jiffies; |
1da177e4 | 8248 | rq->push_cpu = 0; |
0a2966b4 | 8249 | rq->cpu = i; |
1f11eb6a | 8250 | rq->online = 0; |
1da177e4 LT |
8251 | rq->migration_thread = NULL; |
8252 | INIT_LIST_HEAD(&rq->migration_queue); | |
dc938520 | 8253 | rq_attach_root(rq, &def_root_domain); |
1da177e4 | 8254 | #endif |
8f4d37ec | 8255 | init_rq_hrtick(rq); |
1da177e4 | 8256 | atomic_set(&rq->nr_iowait, 0); |
1da177e4 LT |
8257 | } |
8258 | ||
2dd73a4f | 8259 | set_load_weight(&init_task); |
b50f60ce | 8260 | |
e107be36 AK |
8261 | #ifdef CONFIG_PREEMPT_NOTIFIERS |
8262 | INIT_HLIST_HEAD(&init_task.preempt_notifiers); | |
8263 | #endif | |
8264 | ||
c9819f45 | 8265 | #ifdef CONFIG_SMP |
962cf36c | 8266 | open_softirq(SCHED_SOFTIRQ, run_rebalance_domains); |
c9819f45 CL |
8267 | #endif |
8268 | ||
b50f60ce HC |
8269 | #ifdef CONFIG_RT_MUTEXES |
8270 | plist_head_init(&init_task.pi_waiters, &init_task.pi_lock); | |
8271 | #endif | |
8272 | ||
1da177e4 LT |
8273 | /* |
8274 | * The boot idle thread does lazy MMU switching as well: | |
8275 | */ | |
8276 | atomic_inc(&init_mm.mm_count); | |
8277 | enter_lazy_tlb(&init_mm, current); | |
8278 | ||
8279 | /* | |
8280 | * Make us the idle thread. Technically, schedule() should not be | |
8281 | * called from this thread, however somewhere below it might be, | |
8282 | * but because we are the idle thread, we just pick up running again | |
8283 | * when this runqueue becomes "idle". | |
8284 | */ | |
8285 | init_idle(current, smp_processor_id()); | |
dd41f596 IM |
8286 | /* |
8287 | * During early bootup we pretend to be a normal task: | |
8288 | */ | |
8289 | current->sched_class = &fair_sched_class; | |
6892b75e IM |
8290 | |
8291 | scheduler_running = 1; | |
1da177e4 LT |
8292 | } |
8293 | ||
8294 | #ifdef CONFIG_DEBUG_SPINLOCK_SLEEP | |
8295 | void __might_sleep(char *file, int line) | |
8296 | { | |
48f24c4d | 8297 | #ifdef in_atomic |
1da177e4 LT |
8298 | static unsigned long prev_jiffy; /* ratelimiting */ |
8299 | ||
aef745fc IM |
8300 | if ((!in_atomic() && !irqs_disabled()) || |
8301 | system_state != SYSTEM_RUNNING || oops_in_progress) | |
8302 | return; | |
8303 | if (time_before(jiffies, prev_jiffy + HZ) && prev_jiffy) | |
8304 | return; | |
8305 | prev_jiffy = jiffies; | |
8306 | ||
8307 | printk(KERN_ERR | |
8308 | "BUG: sleeping function called from invalid context at %s:%d\n", | |
8309 | file, line); | |
8310 | printk(KERN_ERR | |
8311 | "in_atomic(): %d, irqs_disabled(): %d, pid: %d, name: %s\n", | |
8312 | in_atomic(), irqs_disabled(), | |
8313 | current->pid, current->comm); | |
8314 | ||
8315 | debug_show_held_locks(current); | |
8316 | if (irqs_disabled()) | |
8317 | print_irqtrace_events(current); | |
8318 | dump_stack(); | |
1da177e4 LT |
8319 | #endif |
8320 | } | |
8321 | EXPORT_SYMBOL(__might_sleep); | |
8322 | #endif | |
8323 | ||
8324 | #ifdef CONFIG_MAGIC_SYSRQ | |
3a5e4dc1 AK |
8325 | static void normalize_task(struct rq *rq, struct task_struct *p) |
8326 | { | |
8327 | int on_rq; | |
3e51f33f | 8328 | |
3a5e4dc1 AK |
8329 | update_rq_clock(rq); |
8330 | on_rq = p->se.on_rq; | |
8331 | if (on_rq) | |
8332 | deactivate_task(rq, p, 0); | |
8333 | __setscheduler(rq, p, SCHED_NORMAL, 0); | |
8334 | if (on_rq) { | |
8335 | activate_task(rq, p, 0); | |
8336 | resched_task(rq->curr); | |
8337 | } | |
8338 | } | |
8339 | ||
1da177e4 LT |
8340 | void normalize_rt_tasks(void) |
8341 | { | |
a0f98a1c | 8342 | struct task_struct *g, *p; |
1da177e4 | 8343 | unsigned long flags; |
70b97a7f | 8344 | struct rq *rq; |
1da177e4 | 8345 | |
4cf5d77a | 8346 | read_lock_irqsave(&tasklist_lock, flags); |
a0f98a1c | 8347 | do_each_thread(g, p) { |
178be793 IM |
8348 | /* |
8349 | * Only normalize user tasks: | |
8350 | */ | |
8351 | if (!p->mm) | |
8352 | continue; | |
8353 | ||
6cfb0d5d | 8354 | p->se.exec_start = 0; |
6cfb0d5d | 8355 | #ifdef CONFIG_SCHEDSTATS |
dd41f596 | 8356 | p->se.wait_start = 0; |
dd41f596 | 8357 | p->se.sleep_start = 0; |
dd41f596 | 8358 | p->se.block_start = 0; |
6cfb0d5d | 8359 | #endif |
dd41f596 IM |
8360 | |
8361 | if (!rt_task(p)) { | |
8362 | /* | |
8363 | * Renice negative nice level userspace | |
8364 | * tasks back to 0: | |
8365 | */ | |
8366 | if (TASK_NICE(p) < 0 && p->mm) | |
8367 | set_user_nice(p, 0); | |
1da177e4 | 8368 | continue; |
dd41f596 | 8369 | } |
1da177e4 | 8370 | |
4cf5d77a | 8371 | spin_lock(&p->pi_lock); |
b29739f9 | 8372 | rq = __task_rq_lock(p); |
1da177e4 | 8373 | |
178be793 | 8374 | normalize_task(rq, p); |
3a5e4dc1 | 8375 | |
b29739f9 | 8376 | __task_rq_unlock(rq); |
4cf5d77a | 8377 | spin_unlock(&p->pi_lock); |
a0f98a1c IM |
8378 | } while_each_thread(g, p); |
8379 | ||
4cf5d77a | 8380 | read_unlock_irqrestore(&tasklist_lock, flags); |
1da177e4 LT |
8381 | } |
8382 | ||
8383 | #endif /* CONFIG_MAGIC_SYSRQ */ | |
1df5c10a LT |
8384 | |
8385 | #ifdef CONFIG_IA64 | |
8386 | /* | |
8387 | * These functions are only useful for the IA64 MCA handling. | |
8388 | * | |
8389 | * They can only be called when the whole system has been | |
8390 | * stopped - every CPU needs to be quiescent, and no scheduling | |
8391 | * activity can take place. Using them for anything else would | |
8392 | * be a serious bug, and as a result, they aren't even visible | |
8393 | * under any other configuration. | |
8394 | */ | |
8395 | ||
8396 | /** | |
8397 | * curr_task - return the current task for a given cpu. | |
8398 | * @cpu: the processor in question. | |
8399 | * | |
8400 | * ONLY VALID WHEN THE WHOLE SYSTEM IS STOPPED! | |
8401 | */ | |
36c8b586 | 8402 | struct task_struct *curr_task(int cpu) |
1df5c10a LT |
8403 | { |
8404 | return cpu_curr(cpu); | |
8405 | } | |
8406 | ||
8407 | /** | |
8408 | * set_curr_task - set the current task for a given cpu. | |
8409 | * @cpu: the processor in question. | |
8410 | * @p: the task pointer to set. | |
8411 | * | |
8412 | * Description: This function must only be used when non-maskable interrupts | |
41a2d6cf IM |
8413 | * are serviced on a separate stack. It allows the architecture to switch the |
8414 | * notion of the current task on a cpu in a non-blocking manner. This function | |
1df5c10a LT |
8415 | * must be called with all CPU's synchronized, and interrupts disabled, the |
8416 | * and caller must save the original value of the current task (see | |
8417 | * curr_task() above) and restore that value before reenabling interrupts and | |
8418 | * re-starting the system. | |
8419 | * | |
8420 | * ONLY VALID WHEN THE WHOLE SYSTEM IS STOPPED! | |
8421 | */ | |
36c8b586 | 8422 | void set_curr_task(int cpu, struct task_struct *p) |
1df5c10a LT |
8423 | { |
8424 | cpu_curr(cpu) = p; | |
8425 | } | |
8426 | ||
8427 | #endif | |
29f59db3 | 8428 | |
bccbe08a PZ |
8429 | #ifdef CONFIG_FAIR_GROUP_SCHED |
8430 | static void free_fair_sched_group(struct task_group *tg) | |
6f505b16 PZ |
8431 | { |
8432 | int i; | |
8433 | ||
8434 | for_each_possible_cpu(i) { | |
8435 | if (tg->cfs_rq) | |
8436 | kfree(tg->cfs_rq[i]); | |
8437 | if (tg->se) | |
8438 | kfree(tg->se[i]); | |
6f505b16 PZ |
8439 | } |
8440 | ||
8441 | kfree(tg->cfs_rq); | |
8442 | kfree(tg->se); | |
6f505b16 PZ |
8443 | } |
8444 | ||
ec7dc8ac DG |
8445 | static |
8446 | int alloc_fair_sched_group(struct task_group *tg, struct task_group *parent) | |
29f59db3 | 8447 | { |
29f59db3 | 8448 | struct cfs_rq *cfs_rq; |
eab17229 | 8449 | struct sched_entity *se; |
9b5b7751 | 8450 | struct rq *rq; |
29f59db3 SV |
8451 | int i; |
8452 | ||
434d53b0 | 8453 | tg->cfs_rq = kzalloc(sizeof(cfs_rq) * nr_cpu_ids, GFP_KERNEL); |
29f59db3 SV |
8454 | if (!tg->cfs_rq) |
8455 | goto err; | |
434d53b0 | 8456 | tg->se = kzalloc(sizeof(se) * nr_cpu_ids, GFP_KERNEL); |
29f59db3 SV |
8457 | if (!tg->se) |
8458 | goto err; | |
052f1dc7 PZ |
8459 | |
8460 | tg->shares = NICE_0_LOAD; | |
29f59db3 SV |
8461 | |
8462 | for_each_possible_cpu(i) { | |
9b5b7751 | 8463 | rq = cpu_rq(i); |
29f59db3 | 8464 | |
eab17229 LZ |
8465 | cfs_rq = kzalloc_node(sizeof(struct cfs_rq), |
8466 | GFP_KERNEL, cpu_to_node(i)); | |
29f59db3 SV |
8467 | if (!cfs_rq) |
8468 | goto err; | |
8469 | ||
eab17229 LZ |
8470 | se = kzalloc_node(sizeof(struct sched_entity), |
8471 | GFP_KERNEL, cpu_to_node(i)); | |
29f59db3 SV |
8472 | if (!se) |
8473 | goto err; | |
8474 | ||
eab17229 | 8475 | init_tg_cfs_entry(tg, cfs_rq, se, i, 0, parent->se[i]); |
bccbe08a PZ |
8476 | } |
8477 | ||
8478 | return 1; | |
8479 | ||
8480 | err: | |
8481 | return 0; | |
8482 | } | |
8483 | ||
8484 | static inline void register_fair_sched_group(struct task_group *tg, int cpu) | |
8485 | { | |
8486 | list_add_rcu(&tg->cfs_rq[cpu]->leaf_cfs_rq_list, | |
8487 | &cpu_rq(cpu)->leaf_cfs_rq_list); | |
8488 | } | |
8489 | ||
8490 | static inline void unregister_fair_sched_group(struct task_group *tg, int cpu) | |
8491 | { | |
8492 | list_del_rcu(&tg->cfs_rq[cpu]->leaf_cfs_rq_list); | |
8493 | } | |
6d6bc0ad | 8494 | #else /* !CONFG_FAIR_GROUP_SCHED */ |
bccbe08a PZ |
8495 | static inline void free_fair_sched_group(struct task_group *tg) |
8496 | { | |
8497 | } | |
8498 | ||
ec7dc8ac DG |
8499 | static inline |
8500 | int alloc_fair_sched_group(struct task_group *tg, struct task_group *parent) | |
bccbe08a PZ |
8501 | { |
8502 | return 1; | |
8503 | } | |
8504 | ||
8505 | static inline void register_fair_sched_group(struct task_group *tg, int cpu) | |
8506 | { | |
8507 | } | |
8508 | ||
8509 | static inline void unregister_fair_sched_group(struct task_group *tg, int cpu) | |
8510 | { | |
8511 | } | |
6d6bc0ad | 8512 | #endif /* CONFIG_FAIR_GROUP_SCHED */ |
052f1dc7 PZ |
8513 | |
8514 | #ifdef CONFIG_RT_GROUP_SCHED | |
bccbe08a PZ |
8515 | static void free_rt_sched_group(struct task_group *tg) |
8516 | { | |
8517 | int i; | |
8518 | ||
d0b27fa7 PZ |
8519 | destroy_rt_bandwidth(&tg->rt_bandwidth); |
8520 | ||
bccbe08a PZ |
8521 | for_each_possible_cpu(i) { |
8522 | if (tg->rt_rq) | |
8523 | kfree(tg->rt_rq[i]); | |
8524 | if (tg->rt_se) | |
8525 | kfree(tg->rt_se[i]); | |
8526 | } | |
8527 | ||
8528 | kfree(tg->rt_rq); | |
8529 | kfree(tg->rt_se); | |
8530 | } | |
8531 | ||
ec7dc8ac DG |
8532 | static |
8533 | int alloc_rt_sched_group(struct task_group *tg, struct task_group *parent) | |
bccbe08a PZ |
8534 | { |
8535 | struct rt_rq *rt_rq; | |
eab17229 | 8536 | struct sched_rt_entity *rt_se; |
bccbe08a PZ |
8537 | struct rq *rq; |
8538 | int i; | |
8539 | ||
434d53b0 | 8540 | tg->rt_rq = kzalloc(sizeof(rt_rq) * nr_cpu_ids, GFP_KERNEL); |
bccbe08a PZ |
8541 | if (!tg->rt_rq) |
8542 | goto err; | |
434d53b0 | 8543 | tg->rt_se = kzalloc(sizeof(rt_se) * nr_cpu_ids, GFP_KERNEL); |
bccbe08a PZ |
8544 | if (!tg->rt_se) |
8545 | goto err; | |
8546 | ||
d0b27fa7 PZ |
8547 | init_rt_bandwidth(&tg->rt_bandwidth, |
8548 | ktime_to_ns(def_rt_bandwidth.rt_period), 0); | |
bccbe08a PZ |
8549 | |
8550 | for_each_possible_cpu(i) { | |
8551 | rq = cpu_rq(i); | |
8552 | ||
eab17229 LZ |
8553 | rt_rq = kzalloc_node(sizeof(struct rt_rq), |
8554 | GFP_KERNEL, cpu_to_node(i)); | |
6f505b16 PZ |
8555 | if (!rt_rq) |
8556 | goto err; | |
29f59db3 | 8557 | |
eab17229 LZ |
8558 | rt_se = kzalloc_node(sizeof(struct sched_rt_entity), |
8559 | GFP_KERNEL, cpu_to_node(i)); | |
6f505b16 PZ |
8560 | if (!rt_se) |
8561 | goto err; | |
29f59db3 | 8562 | |
eab17229 | 8563 | init_tg_rt_entry(tg, rt_rq, rt_se, i, 0, parent->rt_se[i]); |
29f59db3 SV |
8564 | } |
8565 | ||
bccbe08a PZ |
8566 | return 1; |
8567 | ||
8568 | err: | |
8569 | return 0; | |
8570 | } | |
8571 | ||
8572 | static inline void register_rt_sched_group(struct task_group *tg, int cpu) | |
8573 | { | |
8574 | list_add_rcu(&tg->rt_rq[cpu]->leaf_rt_rq_list, | |
8575 | &cpu_rq(cpu)->leaf_rt_rq_list); | |
8576 | } | |
8577 | ||
8578 | static inline void unregister_rt_sched_group(struct task_group *tg, int cpu) | |
8579 | { | |
8580 | list_del_rcu(&tg->rt_rq[cpu]->leaf_rt_rq_list); | |
8581 | } | |
6d6bc0ad | 8582 | #else /* !CONFIG_RT_GROUP_SCHED */ |
bccbe08a PZ |
8583 | static inline void free_rt_sched_group(struct task_group *tg) |
8584 | { | |
8585 | } | |
8586 | ||
ec7dc8ac DG |
8587 | static inline |
8588 | int alloc_rt_sched_group(struct task_group *tg, struct task_group *parent) | |
bccbe08a PZ |
8589 | { |
8590 | return 1; | |
8591 | } | |
8592 | ||
8593 | static inline void register_rt_sched_group(struct task_group *tg, int cpu) | |
8594 | { | |
8595 | } | |
8596 | ||
8597 | static inline void unregister_rt_sched_group(struct task_group *tg, int cpu) | |
8598 | { | |
8599 | } | |
6d6bc0ad | 8600 | #endif /* CONFIG_RT_GROUP_SCHED */ |
bccbe08a | 8601 | |
d0b27fa7 | 8602 | #ifdef CONFIG_GROUP_SCHED |
bccbe08a PZ |
8603 | static void free_sched_group(struct task_group *tg) |
8604 | { | |
8605 | free_fair_sched_group(tg); | |
8606 | free_rt_sched_group(tg); | |
8607 | kfree(tg); | |
8608 | } | |
8609 | ||
8610 | /* allocate runqueue etc for a new task group */ | |
ec7dc8ac | 8611 | struct task_group *sched_create_group(struct task_group *parent) |
bccbe08a PZ |
8612 | { |
8613 | struct task_group *tg; | |
8614 | unsigned long flags; | |
8615 | int i; | |
8616 | ||
8617 | tg = kzalloc(sizeof(*tg), GFP_KERNEL); | |
8618 | if (!tg) | |
8619 | return ERR_PTR(-ENOMEM); | |
8620 | ||
ec7dc8ac | 8621 | if (!alloc_fair_sched_group(tg, parent)) |
bccbe08a PZ |
8622 | goto err; |
8623 | ||
ec7dc8ac | 8624 | if (!alloc_rt_sched_group(tg, parent)) |
bccbe08a PZ |
8625 | goto err; |
8626 | ||
8ed36996 | 8627 | spin_lock_irqsave(&task_group_lock, flags); |
9b5b7751 | 8628 | for_each_possible_cpu(i) { |
bccbe08a PZ |
8629 | register_fair_sched_group(tg, i); |
8630 | register_rt_sched_group(tg, i); | |
9b5b7751 | 8631 | } |
6f505b16 | 8632 | list_add_rcu(&tg->list, &task_groups); |
f473aa5e PZ |
8633 | |
8634 | WARN_ON(!parent); /* root should already exist */ | |
8635 | ||
8636 | tg->parent = parent; | |
f473aa5e | 8637 | INIT_LIST_HEAD(&tg->children); |
09f2724a | 8638 | list_add_rcu(&tg->siblings, &parent->children); |
8ed36996 | 8639 | spin_unlock_irqrestore(&task_group_lock, flags); |
29f59db3 | 8640 | |
9b5b7751 | 8641 | return tg; |
29f59db3 SV |
8642 | |
8643 | err: | |
6f505b16 | 8644 | free_sched_group(tg); |
29f59db3 SV |
8645 | return ERR_PTR(-ENOMEM); |
8646 | } | |
8647 | ||
9b5b7751 | 8648 | /* rcu callback to free various structures associated with a task group */ |
6f505b16 | 8649 | static void free_sched_group_rcu(struct rcu_head *rhp) |
29f59db3 | 8650 | { |
29f59db3 | 8651 | /* now it should be safe to free those cfs_rqs */ |
6f505b16 | 8652 | free_sched_group(container_of(rhp, struct task_group, rcu)); |
29f59db3 SV |
8653 | } |
8654 | ||
9b5b7751 | 8655 | /* Destroy runqueue etc associated with a task group */ |
4cf86d77 | 8656 | void sched_destroy_group(struct task_group *tg) |
29f59db3 | 8657 | { |
8ed36996 | 8658 | unsigned long flags; |
9b5b7751 | 8659 | int i; |
29f59db3 | 8660 | |
8ed36996 | 8661 | spin_lock_irqsave(&task_group_lock, flags); |
9b5b7751 | 8662 | for_each_possible_cpu(i) { |
bccbe08a PZ |
8663 | unregister_fair_sched_group(tg, i); |
8664 | unregister_rt_sched_group(tg, i); | |
9b5b7751 | 8665 | } |
6f505b16 | 8666 | list_del_rcu(&tg->list); |
f473aa5e | 8667 | list_del_rcu(&tg->siblings); |
8ed36996 | 8668 | spin_unlock_irqrestore(&task_group_lock, flags); |
9b5b7751 | 8669 | |
9b5b7751 | 8670 | /* wait for possible concurrent references to cfs_rqs complete */ |
6f505b16 | 8671 | call_rcu(&tg->rcu, free_sched_group_rcu); |
29f59db3 SV |
8672 | } |
8673 | ||
9b5b7751 | 8674 | /* change task's runqueue when it moves between groups. |
3a252015 IM |
8675 | * The caller of this function should have put the task in its new group |
8676 | * by now. This function just updates tsk->se.cfs_rq and tsk->se.parent to | |
8677 | * reflect its new group. | |
9b5b7751 SV |
8678 | */ |
8679 | void sched_move_task(struct task_struct *tsk) | |
29f59db3 SV |
8680 | { |
8681 | int on_rq, running; | |
8682 | unsigned long flags; | |
8683 | struct rq *rq; | |
8684 | ||
8685 | rq = task_rq_lock(tsk, &flags); | |
8686 | ||
29f59db3 SV |
8687 | update_rq_clock(rq); |
8688 | ||
051a1d1a | 8689 | running = task_current(rq, tsk); |
29f59db3 SV |
8690 | on_rq = tsk->se.on_rq; |
8691 | ||
0e1f3483 | 8692 | if (on_rq) |
29f59db3 | 8693 | dequeue_task(rq, tsk, 0); |
0e1f3483 HS |
8694 | if (unlikely(running)) |
8695 | tsk->sched_class->put_prev_task(rq, tsk); | |
29f59db3 | 8696 | |
6f505b16 | 8697 | set_task_rq(tsk, task_cpu(tsk)); |
29f59db3 | 8698 | |
810b3817 PZ |
8699 | #ifdef CONFIG_FAIR_GROUP_SCHED |
8700 | if (tsk->sched_class->moved_group) | |
8701 | tsk->sched_class->moved_group(tsk); | |
8702 | #endif | |
8703 | ||
0e1f3483 HS |
8704 | if (unlikely(running)) |
8705 | tsk->sched_class->set_curr_task(rq); | |
8706 | if (on_rq) | |
7074badb | 8707 | enqueue_task(rq, tsk, 0); |
29f59db3 | 8708 | |
29f59db3 SV |
8709 | task_rq_unlock(rq, &flags); |
8710 | } | |
6d6bc0ad | 8711 | #endif /* CONFIG_GROUP_SCHED */ |
29f59db3 | 8712 | |
052f1dc7 | 8713 | #ifdef CONFIG_FAIR_GROUP_SCHED |
c09595f6 | 8714 | static void __set_se_shares(struct sched_entity *se, unsigned long shares) |
29f59db3 SV |
8715 | { |
8716 | struct cfs_rq *cfs_rq = se->cfs_rq; | |
29f59db3 SV |
8717 | int on_rq; |
8718 | ||
29f59db3 | 8719 | on_rq = se->on_rq; |
62fb1851 | 8720 | if (on_rq) |
29f59db3 SV |
8721 | dequeue_entity(cfs_rq, se, 0); |
8722 | ||
8723 | se->load.weight = shares; | |
e05510d0 | 8724 | se->load.inv_weight = 0; |
29f59db3 | 8725 | |
62fb1851 | 8726 | if (on_rq) |
29f59db3 | 8727 | enqueue_entity(cfs_rq, se, 0); |
c09595f6 | 8728 | } |
62fb1851 | 8729 | |
c09595f6 PZ |
8730 | static void set_se_shares(struct sched_entity *se, unsigned long shares) |
8731 | { | |
8732 | struct cfs_rq *cfs_rq = se->cfs_rq; | |
8733 | struct rq *rq = cfs_rq->rq; | |
8734 | unsigned long flags; | |
8735 | ||
8736 | spin_lock_irqsave(&rq->lock, flags); | |
8737 | __set_se_shares(se, shares); | |
8738 | spin_unlock_irqrestore(&rq->lock, flags); | |
29f59db3 SV |
8739 | } |
8740 | ||
8ed36996 PZ |
8741 | static DEFINE_MUTEX(shares_mutex); |
8742 | ||
4cf86d77 | 8743 | int sched_group_set_shares(struct task_group *tg, unsigned long shares) |
29f59db3 SV |
8744 | { |
8745 | int i; | |
8ed36996 | 8746 | unsigned long flags; |
c61935fd | 8747 | |
ec7dc8ac DG |
8748 | /* |
8749 | * We can't change the weight of the root cgroup. | |
8750 | */ | |
8751 | if (!tg->se[0]) | |
8752 | return -EINVAL; | |
8753 | ||
18d95a28 PZ |
8754 | if (shares < MIN_SHARES) |
8755 | shares = MIN_SHARES; | |
cb4ad1ff MX |
8756 | else if (shares > MAX_SHARES) |
8757 | shares = MAX_SHARES; | |
62fb1851 | 8758 | |
8ed36996 | 8759 | mutex_lock(&shares_mutex); |
9b5b7751 | 8760 | if (tg->shares == shares) |
5cb350ba | 8761 | goto done; |
29f59db3 | 8762 | |
8ed36996 | 8763 | spin_lock_irqsave(&task_group_lock, flags); |
bccbe08a PZ |
8764 | for_each_possible_cpu(i) |
8765 | unregister_fair_sched_group(tg, i); | |
f473aa5e | 8766 | list_del_rcu(&tg->siblings); |
8ed36996 | 8767 | spin_unlock_irqrestore(&task_group_lock, flags); |
6b2d7700 SV |
8768 | |
8769 | /* wait for any ongoing reference to this group to finish */ | |
8770 | synchronize_sched(); | |
8771 | ||
8772 | /* | |
8773 | * Now we are free to modify the group's share on each cpu | |
8774 | * w/o tripping rebalance_share or load_balance_fair. | |
8775 | */ | |
9b5b7751 | 8776 | tg->shares = shares; |
c09595f6 PZ |
8777 | for_each_possible_cpu(i) { |
8778 | /* | |
8779 | * force a rebalance | |
8780 | */ | |
8781 | cfs_rq_set_shares(tg->cfs_rq[i], 0); | |
cb4ad1ff | 8782 | set_se_shares(tg->se[i], shares); |
c09595f6 | 8783 | } |
29f59db3 | 8784 | |
6b2d7700 SV |
8785 | /* |
8786 | * Enable load balance activity on this group, by inserting it back on | |
8787 | * each cpu's rq->leaf_cfs_rq_list. | |
8788 | */ | |
8ed36996 | 8789 | spin_lock_irqsave(&task_group_lock, flags); |
bccbe08a PZ |
8790 | for_each_possible_cpu(i) |
8791 | register_fair_sched_group(tg, i); | |
f473aa5e | 8792 | list_add_rcu(&tg->siblings, &tg->parent->children); |
8ed36996 | 8793 | spin_unlock_irqrestore(&task_group_lock, flags); |
5cb350ba | 8794 | done: |
8ed36996 | 8795 | mutex_unlock(&shares_mutex); |
9b5b7751 | 8796 | return 0; |
29f59db3 SV |
8797 | } |
8798 | ||
5cb350ba DG |
8799 | unsigned long sched_group_shares(struct task_group *tg) |
8800 | { | |
8801 | return tg->shares; | |
8802 | } | |
052f1dc7 | 8803 | #endif |
5cb350ba | 8804 | |
052f1dc7 | 8805 | #ifdef CONFIG_RT_GROUP_SCHED |
6f505b16 | 8806 | /* |
9f0c1e56 | 8807 | * Ensure that the real time constraints are schedulable. |
6f505b16 | 8808 | */ |
9f0c1e56 PZ |
8809 | static DEFINE_MUTEX(rt_constraints_mutex); |
8810 | ||
8811 | static unsigned long to_ratio(u64 period, u64 runtime) | |
8812 | { | |
8813 | if (runtime == RUNTIME_INF) | |
9a7e0b18 | 8814 | return 1ULL << 20; |
9f0c1e56 | 8815 | |
9a7e0b18 | 8816 | return div64_u64(runtime << 20, period); |
9f0c1e56 PZ |
8817 | } |
8818 | ||
9a7e0b18 PZ |
8819 | /* Must be called with tasklist_lock held */ |
8820 | static inline int tg_has_rt_tasks(struct task_group *tg) | |
b40b2e8e | 8821 | { |
9a7e0b18 | 8822 | struct task_struct *g, *p; |
b40b2e8e | 8823 | |
9a7e0b18 PZ |
8824 | do_each_thread(g, p) { |
8825 | if (rt_task(p) && rt_rq_of_se(&p->rt)->tg == tg) | |
8826 | return 1; | |
8827 | } while_each_thread(g, p); | |
b40b2e8e | 8828 | |
9a7e0b18 PZ |
8829 | return 0; |
8830 | } | |
b40b2e8e | 8831 | |
9a7e0b18 PZ |
8832 | struct rt_schedulable_data { |
8833 | struct task_group *tg; | |
8834 | u64 rt_period; | |
8835 | u64 rt_runtime; | |
8836 | }; | |
b40b2e8e | 8837 | |
9a7e0b18 PZ |
8838 | static int tg_schedulable(struct task_group *tg, void *data) |
8839 | { | |
8840 | struct rt_schedulable_data *d = data; | |
8841 | struct task_group *child; | |
8842 | unsigned long total, sum = 0; | |
8843 | u64 period, runtime; | |
b40b2e8e | 8844 | |
9a7e0b18 PZ |
8845 | period = ktime_to_ns(tg->rt_bandwidth.rt_period); |
8846 | runtime = tg->rt_bandwidth.rt_runtime; | |
b40b2e8e | 8847 | |
9a7e0b18 PZ |
8848 | if (tg == d->tg) { |
8849 | period = d->rt_period; | |
8850 | runtime = d->rt_runtime; | |
b40b2e8e | 8851 | } |
b40b2e8e | 8852 | |
4653f803 PZ |
8853 | /* |
8854 | * Cannot have more runtime than the period. | |
8855 | */ | |
8856 | if (runtime > period && runtime != RUNTIME_INF) | |
8857 | return -EINVAL; | |
6f505b16 | 8858 | |
4653f803 PZ |
8859 | /* |
8860 | * Ensure we don't starve existing RT tasks. | |
8861 | */ | |
9a7e0b18 PZ |
8862 | if (rt_bandwidth_enabled() && !runtime && tg_has_rt_tasks(tg)) |
8863 | return -EBUSY; | |
6f505b16 | 8864 | |
9a7e0b18 | 8865 | total = to_ratio(period, runtime); |
6f505b16 | 8866 | |
4653f803 PZ |
8867 | /* |
8868 | * Nobody can have more than the global setting allows. | |
8869 | */ | |
8870 | if (total > to_ratio(global_rt_period(), global_rt_runtime())) | |
8871 | return -EINVAL; | |
6f505b16 | 8872 | |
4653f803 PZ |
8873 | /* |
8874 | * The sum of our children's runtime should not exceed our own. | |
8875 | */ | |
9a7e0b18 PZ |
8876 | list_for_each_entry_rcu(child, &tg->children, siblings) { |
8877 | period = ktime_to_ns(child->rt_bandwidth.rt_period); | |
8878 | runtime = child->rt_bandwidth.rt_runtime; | |
6f505b16 | 8879 | |
9a7e0b18 PZ |
8880 | if (child == d->tg) { |
8881 | period = d->rt_period; | |
8882 | runtime = d->rt_runtime; | |
8883 | } | |
6f505b16 | 8884 | |
9a7e0b18 | 8885 | sum += to_ratio(period, runtime); |
9f0c1e56 | 8886 | } |
6f505b16 | 8887 | |
9a7e0b18 PZ |
8888 | if (sum > total) |
8889 | return -EINVAL; | |
8890 | ||
8891 | return 0; | |
6f505b16 PZ |
8892 | } |
8893 | ||
9a7e0b18 | 8894 | static int __rt_schedulable(struct task_group *tg, u64 period, u64 runtime) |
521f1a24 | 8895 | { |
9a7e0b18 PZ |
8896 | struct rt_schedulable_data data = { |
8897 | .tg = tg, | |
8898 | .rt_period = period, | |
8899 | .rt_runtime = runtime, | |
8900 | }; | |
8901 | ||
8902 | return walk_tg_tree(tg_schedulable, tg_nop, &data); | |
521f1a24 DG |
8903 | } |
8904 | ||
d0b27fa7 PZ |
8905 | static int tg_set_bandwidth(struct task_group *tg, |
8906 | u64 rt_period, u64 rt_runtime) | |
6f505b16 | 8907 | { |
ac086bc2 | 8908 | int i, err = 0; |
9f0c1e56 | 8909 | |
9f0c1e56 | 8910 | mutex_lock(&rt_constraints_mutex); |
521f1a24 | 8911 | read_lock(&tasklist_lock); |
9a7e0b18 PZ |
8912 | err = __rt_schedulable(tg, rt_period, rt_runtime); |
8913 | if (err) | |
9f0c1e56 | 8914 | goto unlock; |
ac086bc2 PZ |
8915 | |
8916 | spin_lock_irq(&tg->rt_bandwidth.rt_runtime_lock); | |
d0b27fa7 PZ |
8917 | tg->rt_bandwidth.rt_period = ns_to_ktime(rt_period); |
8918 | tg->rt_bandwidth.rt_runtime = rt_runtime; | |
ac086bc2 PZ |
8919 | |
8920 | for_each_possible_cpu(i) { | |
8921 | struct rt_rq *rt_rq = tg->rt_rq[i]; | |
8922 | ||
8923 | spin_lock(&rt_rq->rt_runtime_lock); | |
8924 | rt_rq->rt_runtime = rt_runtime; | |
8925 | spin_unlock(&rt_rq->rt_runtime_lock); | |
8926 | } | |
8927 | spin_unlock_irq(&tg->rt_bandwidth.rt_runtime_lock); | |
9f0c1e56 | 8928 | unlock: |
521f1a24 | 8929 | read_unlock(&tasklist_lock); |
9f0c1e56 PZ |
8930 | mutex_unlock(&rt_constraints_mutex); |
8931 | ||
8932 | return err; | |
6f505b16 PZ |
8933 | } |
8934 | ||
d0b27fa7 PZ |
8935 | int sched_group_set_rt_runtime(struct task_group *tg, long rt_runtime_us) |
8936 | { | |
8937 | u64 rt_runtime, rt_period; | |
8938 | ||
8939 | rt_period = ktime_to_ns(tg->rt_bandwidth.rt_period); | |
8940 | rt_runtime = (u64)rt_runtime_us * NSEC_PER_USEC; | |
8941 | if (rt_runtime_us < 0) | |
8942 | rt_runtime = RUNTIME_INF; | |
8943 | ||
8944 | return tg_set_bandwidth(tg, rt_period, rt_runtime); | |
8945 | } | |
8946 | ||
9f0c1e56 PZ |
8947 | long sched_group_rt_runtime(struct task_group *tg) |
8948 | { | |
8949 | u64 rt_runtime_us; | |
8950 | ||
d0b27fa7 | 8951 | if (tg->rt_bandwidth.rt_runtime == RUNTIME_INF) |
9f0c1e56 PZ |
8952 | return -1; |
8953 | ||
d0b27fa7 | 8954 | rt_runtime_us = tg->rt_bandwidth.rt_runtime; |
9f0c1e56 PZ |
8955 | do_div(rt_runtime_us, NSEC_PER_USEC); |
8956 | return rt_runtime_us; | |
8957 | } | |
d0b27fa7 PZ |
8958 | |
8959 | int sched_group_set_rt_period(struct task_group *tg, long rt_period_us) | |
8960 | { | |
8961 | u64 rt_runtime, rt_period; | |
8962 | ||
8963 | rt_period = (u64)rt_period_us * NSEC_PER_USEC; | |
8964 | rt_runtime = tg->rt_bandwidth.rt_runtime; | |
8965 | ||
619b0488 R |
8966 | if (rt_period == 0) |
8967 | return -EINVAL; | |
8968 | ||
d0b27fa7 PZ |
8969 | return tg_set_bandwidth(tg, rt_period, rt_runtime); |
8970 | } | |
8971 | ||
8972 | long sched_group_rt_period(struct task_group *tg) | |
8973 | { | |
8974 | u64 rt_period_us; | |
8975 | ||
8976 | rt_period_us = ktime_to_ns(tg->rt_bandwidth.rt_period); | |
8977 | do_div(rt_period_us, NSEC_PER_USEC); | |
8978 | return rt_period_us; | |
8979 | } | |
8980 | ||
8981 | static int sched_rt_global_constraints(void) | |
8982 | { | |
4653f803 | 8983 | u64 runtime, period; |
d0b27fa7 PZ |
8984 | int ret = 0; |
8985 | ||
ec5d4989 HS |
8986 | if (sysctl_sched_rt_period <= 0) |
8987 | return -EINVAL; | |
8988 | ||
4653f803 PZ |
8989 | runtime = global_rt_runtime(); |
8990 | period = global_rt_period(); | |
8991 | ||
8992 | /* | |
8993 | * Sanity check on the sysctl variables. | |
8994 | */ | |
8995 | if (runtime > period && runtime != RUNTIME_INF) | |
8996 | return -EINVAL; | |
10b612f4 | 8997 | |
d0b27fa7 | 8998 | mutex_lock(&rt_constraints_mutex); |
9a7e0b18 | 8999 | read_lock(&tasklist_lock); |
4653f803 | 9000 | ret = __rt_schedulable(NULL, 0, 0); |
9a7e0b18 | 9001 | read_unlock(&tasklist_lock); |
d0b27fa7 PZ |
9002 | mutex_unlock(&rt_constraints_mutex); |
9003 | ||
9004 | return ret; | |
9005 | } | |
6d6bc0ad | 9006 | #else /* !CONFIG_RT_GROUP_SCHED */ |
d0b27fa7 PZ |
9007 | static int sched_rt_global_constraints(void) |
9008 | { | |
ac086bc2 PZ |
9009 | unsigned long flags; |
9010 | int i; | |
9011 | ||
ec5d4989 HS |
9012 | if (sysctl_sched_rt_period <= 0) |
9013 | return -EINVAL; | |
9014 | ||
ac086bc2 PZ |
9015 | spin_lock_irqsave(&def_rt_bandwidth.rt_runtime_lock, flags); |
9016 | for_each_possible_cpu(i) { | |
9017 | struct rt_rq *rt_rq = &cpu_rq(i)->rt; | |
9018 | ||
9019 | spin_lock(&rt_rq->rt_runtime_lock); | |
9020 | rt_rq->rt_runtime = global_rt_runtime(); | |
9021 | spin_unlock(&rt_rq->rt_runtime_lock); | |
9022 | } | |
9023 | spin_unlock_irqrestore(&def_rt_bandwidth.rt_runtime_lock, flags); | |
9024 | ||
d0b27fa7 PZ |
9025 | return 0; |
9026 | } | |
6d6bc0ad | 9027 | #endif /* CONFIG_RT_GROUP_SCHED */ |
d0b27fa7 PZ |
9028 | |
9029 | int sched_rt_handler(struct ctl_table *table, int write, | |
9030 | struct file *filp, void __user *buffer, size_t *lenp, | |
9031 | loff_t *ppos) | |
9032 | { | |
9033 | int ret; | |
9034 | int old_period, old_runtime; | |
9035 | static DEFINE_MUTEX(mutex); | |
9036 | ||
9037 | mutex_lock(&mutex); | |
9038 | old_period = sysctl_sched_rt_period; | |
9039 | old_runtime = sysctl_sched_rt_runtime; | |
9040 | ||
9041 | ret = proc_dointvec(table, write, filp, buffer, lenp, ppos); | |
9042 | ||
9043 | if (!ret && write) { | |
9044 | ret = sched_rt_global_constraints(); | |
9045 | if (ret) { | |
9046 | sysctl_sched_rt_period = old_period; | |
9047 | sysctl_sched_rt_runtime = old_runtime; | |
9048 | } else { | |
9049 | def_rt_bandwidth.rt_runtime = global_rt_runtime(); | |
9050 | def_rt_bandwidth.rt_period = | |
9051 | ns_to_ktime(global_rt_period()); | |
9052 | } | |
9053 | } | |
9054 | mutex_unlock(&mutex); | |
9055 | ||
9056 | return ret; | |
9057 | } | |
68318b8e | 9058 | |
052f1dc7 | 9059 | #ifdef CONFIG_CGROUP_SCHED |
68318b8e SV |
9060 | |
9061 | /* return corresponding task_group object of a cgroup */ | |
2b01dfe3 | 9062 | static inline struct task_group *cgroup_tg(struct cgroup *cgrp) |
68318b8e | 9063 | { |
2b01dfe3 PM |
9064 | return container_of(cgroup_subsys_state(cgrp, cpu_cgroup_subsys_id), |
9065 | struct task_group, css); | |
68318b8e SV |
9066 | } |
9067 | ||
9068 | static struct cgroup_subsys_state * | |
2b01dfe3 | 9069 | cpu_cgroup_create(struct cgroup_subsys *ss, struct cgroup *cgrp) |
68318b8e | 9070 | { |
ec7dc8ac | 9071 | struct task_group *tg, *parent; |
68318b8e | 9072 | |
2b01dfe3 | 9073 | if (!cgrp->parent) { |
68318b8e | 9074 | /* This is early initialization for the top cgroup */ |
68318b8e SV |
9075 | return &init_task_group.css; |
9076 | } | |
9077 | ||
ec7dc8ac DG |
9078 | parent = cgroup_tg(cgrp->parent); |
9079 | tg = sched_create_group(parent); | |
68318b8e SV |
9080 | if (IS_ERR(tg)) |
9081 | return ERR_PTR(-ENOMEM); | |
9082 | ||
68318b8e SV |
9083 | return &tg->css; |
9084 | } | |
9085 | ||
41a2d6cf IM |
9086 | static void |
9087 | cpu_cgroup_destroy(struct cgroup_subsys *ss, struct cgroup *cgrp) | |
68318b8e | 9088 | { |
2b01dfe3 | 9089 | struct task_group *tg = cgroup_tg(cgrp); |
68318b8e SV |
9090 | |
9091 | sched_destroy_group(tg); | |
9092 | } | |
9093 | ||
41a2d6cf IM |
9094 | static int |
9095 | cpu_cgroup_can_attach(struct cgroup_subsys *ss, struct cgroup *cgrp, | |
9096 | struct task_struct *tsk) | |
68318b8e | 9097 | { |
b68aa230 PZ |
9098 | #ifdef CONFIG_RT_GROUP_SCHED |
9099 | /* Don't accept realtime tasks when there is no way for them to run */ | |
d0b27fa7 | 9100 | if (rt_task(tsk) && cgroup_tg(cgrp)->rt_bandwidth.rt_runtime == 0) |
b68aa230 PZ |
9101 | return -EINVAL; |
9102 | #else | |
68318b8e SV |
9103 | /* We don't support RT-tasks being in separate groups */ |
9104 | if (tsk->sched_class != &fair_sched_class) | |
9105 | return -EINVAL; | |
b68aa230 | 9106 | #endif |
68318b8e SV |
9107 | |
9108 | return 0; | |
9109 | } | |
9110 | ||
9111 | static void | |
2b01dfe3 | 9112 | cpu_cgroup_attach(struct cgroup_subsys *ss, struct cgroup *cgrp, |
68318b8e SV |
9113 | struct cgroup *old_cont, struct task_struct *tsk) |
9114 | { | |
9115 | sched_move_task(tsk); | |
9116 | } | |
9117 | ||
052f1dc7 | 9118 | #ifdef CONFIG_FAIR_GROUP_SCHED |
f4c753b7 | 9119 | static int cpu_shares_write_u64(struct cgroup *cgrp, struct cftype *cftype, |
2b01dfe3 | 9120 | u64 shareval) |
68318b8e | 9121 | { |
2b01dfe3 | 9122 | return sched_group_set_shares(cgroup_tg(cgrp), shareval); |
68318b8e SV |
9123 | } |
9124 | ||
f4c753b7 | 9125 | static u64 cpu_shares_read_u64(struct cgroup *cgrp, struct cftype *cft) |
68318b8e | 9126 | { |
2b01dfe3 | 9127 | struct task_group *tg = cgroup_tg(cgrp); |
68318b8e SV |
9128 | |
9129 | return (u64) tg->shares; | |
9130 | } | |
6d6bc0ad | 9131 | #endif /* CONFIG_FAIR_GROUP_SCHED */ |
68318b8e | 9132 | |
052f1dc7 | 9133 | #ifdef CONFIG_RT_GROUP_SCHED |
0c70814c | 9134 | static int cpu_rt_runtime_write(struct cgroup *cgrp, struct cftype *cft, |
06ecb27c | 9135 | s64 val) |
6f505b16 | 9136 | { |
06ecb27c | 9137 | return sched_group_set_rt_runtime(cgroup_tg(cgrp), val); |
6f505b16 PZ |
9138 | } |
9139 | ||
06ecb27c | 9140 | static s64 cpu_rt_runtime_read(struct cgroup *cgrp, struct cftype *cft) |
6f505b16 | 9141 | { |
06ecb27c | 9142 | return sched_group_rt_runtime(cgroup_tg(cgrp)); |
6f505b16 | 9143 | } |
d0b27fa7 PZ |
9144 | |
9145 | static int cpu_rt_period_write_uint(struct cgroup *cgrp, struct cftype *cftype, | |
9146 | u64 rt_period_us) | |
9147 | { | |
9148 | return sched_group_set_rt_period(cgroup_tg(cgrp), rt_period_us); | |
9149 | } | |
9150 | ||
9151 | static u64 cpu_rt_period_read_uint(struct cgroup *cgrp, struct cftype *cft) | |
9152 | { | |
9153 | return sched_group_rt_period(cgroup_tg(cgrp)); | |
9154 | } | |
6d6bc0ad | 9155 | #endif /* CONFIG_RT_GROUP_SCHED */ |
6f505b16 | 9156 | |
fe5c7cc2 | 9157 | static struct cftype cpu_files[] = { |
052f1dc7 | 9158 | #ifdef CONFIG_FAIR_GROUP_SCHED |
fe5c7cc2 PM |
9159 | { |
9160 | .name = "shares", | |
f4c753b7 PM |
9161 | .read_u64 = cpu_shares_read_u64, |
9162 | .write_u64 = cpu_shares_write_u64, | |
fe5c7cc2 | 9163 | }, |
052f1dc7 PZ |
9164 | #endif |
9165 | #ifdef CONFIG_RT_GROUP_SCHED | |
6f505b16 | 9166 | { |
9f0c1e56 | 9167 | .name = "rt_runtime_us", |
06ecb27c PM |
9168 | .read_s64 = cpu_rt_runtime_read, |
9169 | .write_s64 = cpu_rt_runtime_write, | |
6f505b16 | 9170 | }, |
d0b27fa7 PZ |
9171 | { |
9172 | .name = "rt_period_us", | |
f4c753b7 PM |
9173 | .read_u64 = cpu_rt_period_read_uint, |
9174 | .write_u64 = cpu_rt_period_write_uint, | |
d0b27fa7 | 9175 | }, |
052f1dc7 | 9176 | #endif |
68318b8e SV |
9177 | }; |
9178 | ||
9179 | static int cpu_cgroup_populate(struct cgroup_subsys *ss, struct cgroup *cont) | |
9180 | { | |
fe5c7cc2 | 9181 | return cgroup_add_files(cont, ss, cpu_files, ARRAY_SIZE(cpu_files)); |
68318b8e SV |
9182 | } |
9183 | ||
9184 | struct cgroup_subsys cpu_cgroup_subsys = { | |
38605cae IM |
9185 | .name = "cpu", |
9186 | .create = cpu_cgroup_create, | |
9187 | .destroy = cpu_cgroup_destroy, | |
9188 | .can_attach = cpu_cgroup_can_attach, | |
9189 | .attach = cpu_cgroup_attach, | |
9190 | .populate = cpu_cgroup_populate, | |
9191 | .subsys_id = cpu_cgroup_subsys_id, | |
68318b8e SV |
9192 | .early_init = 1, |
9193 | }; | |
9194 | ||
052f1dc7 | 9195 | #endif /* CONFIG_CGROUP_SCHED */ |
d842de87 SV |
9196 | |
9197 | #ifdef CONFIG_CGROUP_CPUACCT | |
9198 | ||
9199 | /* | |
9200 | * CPU accounting code for task groups. | |
9201 | * | |
9202 | * Based on the work by Paul Menage (menage@google.com) and Balbir Singh | |
9203 | * (balbir@in.ibm.com). | |
9204 | */ | |
9205 | ||
934352f2 | 9206 | /* track cpu usage of a group of tasks and its child groups */ |
d842de87 SV |
9207 | struct cpuacct { |
9208 | struct cgroup_subsys_state css; | |
9209 | /* cpuusage holds pointer to a u64-type object on every cpu */ | |
9210 | u64 *cpuusage; | |
934352f2 | 9211 | struct cpuacct *parent; |
d842de87 SV |
9212 | }; |
9213 | ||
9214 | struct cgroup_subsys cpuacct_subsys; | |
9215 | ||
9216 | /* return cpu accounting group corresponding to this container */ | |
32cd756a | 9217 | static inline struct cpuacct *cgroup_ca(struct cgroup *cgrp) |
d842de87 | 9218 | { |
32cd756a | 9219 | return container_of(cgroup_subsys_state(cgrp, cpuacct_subsys_id), |
d842de87 SV |
9220 | struct cpuacct, css); |
9221 | } | |
9222 | ||
9223 | /* return cpu accounting group to which this task belongs */ | |
9224 | static inline struct cpuacct *task_ca(struct task_struct *tsk) | |
9225 | { | |
9226 | return container_of(task_subsys_state(tsk, cpuacct_subsys_id), | |
9227 | struct cpuacct, css); | |
9228 | } | |
9229 | ||
9230 | /* create a new cpu accounting group */ | |
9231 | static struct cgroup_subsys_state *cpuacct_create( | |
32cd756a | 9232 | struct cgroup_subsys *ss, struct cgroup *cgrp) |
d842de87 SV |
9233 | { |
9234 | struct cpuacct *ca = kzalloc(sizeof(*ca), GFP_KERNEL); | |
9235 | ||
9236 | if (!ca) | |
9237 | return ERR_PTR(-ENOMEM); | |
9238 | ||
9239 | ca->cpuusage = alloc_percpu(u64); | |
9240 | if (!ca->cpuusage) { | |
9241 | kfree(ca); | |
9242 | return ERR_PTR(-ENOMEM); | |
9243 | } | |
9244 | ||
934352f2 BR |
9245 | if (cgrp->parent) |
9246 | ca->parent = cgroup_ca(cgrp->parent); | |
9247 | ||
d842de87 SV |
9248 | return &ca->css; |
9249 | } | |
9250 | ||
9251 | /* destroy an existing cpu accounting group */ | |
41a2d6cf | 9252 | static void |
32cd756a | 9253 | cpuacct_destroy(struct cgroup_subsys *ss, struct cgroup *cgrp) |
d842de87 | 9254 | { |
32cd756a | 9255 | struct cpuacct *ca = cgroup_ca(cgrp); |
d842de87 SV |
9256 | |
9257 | free_percpu(ca->cpuusage); | |
9258 | kfree(ca); | |
9259 | } | |
9260 | ||
9261 | /* return total cpu usage (in nanoseconds) of a group */ | |
32cd756a | 9262 | static u64 cpuusage_read(struct cgroup *cgrp, struct cftype *cft) |
d842de87 | 9263 | { |
32cd756a | 9264 | struct cpuacct *ca = cgroup_ca(cgrp); |
d842de87 SV |
9265 | u64 totalcpuusage = 0; |
9266 | int i; | |
9267 | ||
9268 | for_each_possible_cpu(i) { | |
9269 | u64 *cpuusage = percpu_ptr(ca->cpuusage, i); | |
9270 | ||
9271 | /* | |
9272 | * Take rq->lock to make 64-bit addition safe on 32-bit | |
9273 | * platforms. | |
9274 | */ | |
9275 | spin_lock_irq(&cpu_rq(i)->lock); | |
9276 | totalcpuusage += *cpuusage; | |
9277 | spin_unlock_irq(&cpu_rq(i)->lock); | |
9278 | } | |
9279 | ||
9280 | return totalcpuusage; | |
9281 | } | |
9282 | ||
0297b803 DG |
9283 | static int cpuusage_write(struct cgroup *cgrp, struct cftype *cftype, |
9284 | u64 reset) | |
9285 | { | |
9286 | struct cpuacct *ca = cgroup_ca(cgrp); | |
9287 | int err = 0; | |
9288 | int i; | |
9289 | ||
9290 | if (reset) { | |
9291 | err = -EINVAL; | |
9292 | goto out; | |
9293 | } | |
9294 | ||
9295 | for_each_possible_cpu(i) { | |
9296 | u64 *cpuusage = percpu_ptr(ca->cpuusage, i); | |
9297 | ||
9298 | spin_lock_irq(&cpu_rq(i)->lock); | |
9299 | *cpuusage = 0; | |
9300 | spin_unlock_irq(&cpu_rq(i)->lock); | |
9301 | } | |
9302 | out: | |
9303 | return err; | |
9304 | } | |
9305 | ||
d842de87 SV |
9306 | static struct cftype files[] = { |
9307 | { | |
9308 | .name = "usage", | |
f4c753b7 PM |
9309 | .read_u64 = cpuusage_read, |
9310 | .write_u64 = cpuusage_write, | |
d842de87 SV |
9311 | }, |
9312 | }; | |
9313 | ||
32cd756a | 9314 | static int cpuacct_populate(struct cgroup_subsys *ss, struct cgroup *cgrp) |
d842de87 | 9315 | { |
32cd756a | 9316 | return cgroup_add_files(cgrp, ss, files, ARRAY_SIZE(files)); |
d842de87 SV |
9317 | } |
9318 | ||
9319 | /* | |
9320 | * charge this task's execution time to its accounting group. | |
9321 | * | |
9322 | * called with rq->lock held. | |
9323 | */ | |
9324 | static void cpuacct_charge(struct task_struct *tsk, u64 cputime) | |
9325 | { | |
9326 | struct cpuacct *ca; | |
934352f2 | 9327 | int cpu; |
d842de87 SV |
9328 | |
9329 | if (!cpuacct_subsys.active) | |
9330 | return; | |
9331 | ||
934352f2 | 9332 | cpu = task_cpu(tsk); |
d842de87 | 9333 | ca = task_ca(tsk); |
d842de87 | 9334 | |
934352f2 BR |
9335 | for (; ca; ca = ca->parent) { |
9336 | u64 *cpuusage = percpu_ptr(ca->cpuusage, cpu); | |
d842de87 SV |
9337 | *cpuusage += cputime; |
9338 | } | |
9339 | } | |
9340 | ||
9341 | struct cgroup_subsys cpuacct_subsys = { | |
9342 | .name = "cpuacct", | |
9343 | .create = cpuacct_create, | |
9344 | .destroy = cpuacct_destroy, | |
9345 | .populate = cpuacct_populate, | |
9346 | .subsys_id = cpuacct_subsys_id, | |
9347 | }; | |
9348 | #endif /* CONFIG_CGROUP_CPUACCT */ |