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1da177e4 LT |
1 | /* |
2 | * kernel/sched.c | |
3 | * | |
4 | * Kernel scheduler and related syscalls | |
5 | * | |
6 | * Copyright (C) 1991-2002 Linus Torvalds | |
7 | * | |
8 | * 1996-12-23 Modified by Dave Grothe to fix bugs in semaphores and | |
9 | * make semaphores SMP safe | |
10 | * 1998-11-19 Implemented schedule_timeout() and related stuff | |
11 | * by Andrea Arcangeli | |
12 | * 2002-01-04 New ultra-scalable O(1) scheduler by Ingo Molnar: | |
13 | * hybrid priority-list and round-robin design with | |
14 | * an array-switch method of distributing timeslices | |
15 | * and per-CPU runqueues. Cleanups and useful suggestions | |
16 | * by Davide Libenzi, preemptible kernel bits by Robert Love. | |
17 | * 2003-09-03 Interactivity tuning by Con Kolivas. | |
18 | * 2004-04-02 Scheduler domains code by Nick Piggin | |
c31f2e8a IM |
19 | * 2007-04-15 Work begun on replacing all interactivity tuning with a |
20 | * fair scheduling design by Con Kolivas. | |
21 | * 2007-05-05 Load balancing (smp-nice) and other improvements | |
22 | * by Peter Williams | |
23 | * 2007-05-06 Interactivity improvements to CFS by Mike Galbraith | |
24 | * 2007-07-01 Group scheduling enhancements by Srivatsa Vaddagiri | |
b9131769 IM |
25 | * 2007-11-29 RT balancing improvements by Steven Rostedt, Gregory Haskins, |
26 | * Thomas Gleixner, Mike Kravetz | |
1da177e4 LT |
27 | */ |
28 | ||
29 | #include <linux/mm.h> | |
30 | #include <linux/module.h> | |
31 | #include <linux/nmi.h> | |
32 | #include <linux/init.h> | |
dff06c15 | 33 | #include <linux/uaccess.h> |
1da177e4 | 34 | #include <linux/highmem.h> |
1da177e4 LT |
35 | #include <asm/mmu_context.h> |
36 | #include <linux/interrupt.h> | |
c59ede7b | 37 | #include <linux/capability.h> |
1da177e4 LT |
38 | #include <linux/completion.h> |
39 | #include <linux/kernel_stat.h> | |
9a11b49a | 40 | #include <linux/debug_locks.h> |
cdd6c482 | 41 | #include <linux/perf_event.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> | |
b5aadf7f | 57 | #include <linux/proc_fs.h> |
1da177e4 | 58 | #include <linux/seq_file.h> |
969c7921 | 59 | #include <linux/stop_machine.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> |
dff06c15 | 66 | #include <linux/unistd.h> |
f5ff8422 | 67 | #include <linux/pagemap.h> |
8f4d37ec | 68 | #include <linux/hrtimer.h> |
30914a58 | 69 | #include <linux/tick.h> |
f00b45c1 PZ |
70 | #include <linux/debugfs.h> |
71 | #include <linux/ctype.h> | |
6cd8a4bb | 72 | #include <linux/ftrace.h> |
5a0e3ad6 | 73 | #include <linux/slab.h> |
1da177e4 | 74 | |
5517d86b | 75 | #include <asm/tlb.h> |
838225b4 | 76 | #include <asm/irq_regs.h> |
335d7afb | 77 | #include <asm/mutex.h> |
e6e6685a GC |
78 | #ifdef CONFIG_PARAVIRT |
79 | #include <asm/paravirt.h> | |
80 | #endif | |
1da177e4 | 81 | |
6e0534f2 | 82 | #include "sched_cpupri.h" |
21aa9af0 | 83 | #include "workqueue_sched.h" |
5091faa4 | 84 | #include "sched_autogroup.h" |
6e0534f2 | 85 | |
a8d154b0 | 86 | #define CREATE_TRACE_POINTS |
ad8d75ff | 87 | #include <trace/events/sched.h> |
a8d154b0 | 88 | |
1da177e4 LT |
89 | /* |
90 | * Convert user-nice values [ -20 ... 0 ... 19 ] | |
91 | * to static priority [ MAX_RT_PRIO..MAX_PRIO-1 ], | |
92 | * and back. | |
93 | */ | |
94 | #define NICE_TO_PRIO(nice) (MAX_RT_PRIO + (nice) + 20) | |
95 | #define PRIO_TO_NICE(prio) ((prio) - MAX_RT_PRIO - 20) | |
96 | #define TASK_NICE(p) PRIO_TO_NICE((p)->static_prio) | |
97 | ||
98 | /* | |
99 | * 'User priority' is the nice value converted to something we | |
100 | * can work with better when scaling various scheduler parameters, | |
101 | * it's a [ 0 ... 39 ] range. | |
102 | */ | |
103 | #define USER_PRIO(p) ((p)-MAX_RT_PRIO) | |
104 | #define TASK_USER_PRIO(p) USER_PRIO((p)->static_prio) | |
105 | #define MAX_USER_PRIO (USER_PRIO(MAX_PRIO)) | |
106 | ||
107 | /* | |
d7876a08 | 108 | * Helpers for converting nanosecond timing to jiffy resolution |
1da177e4 | 109 | */ |
d6322faf | 110 | #define NS_TO_JIFFIES(TIME) ((unsigned long)(TIME) / (NSEC_PER_SEC / HZ)) |
1da177e4 | 111 | |
6aa645ea IM |
112 | #define NICE_0_LOAD SCHED_LOAD_SCALE |
113 | #define NICE_0_SHIFT SCHED_LOAD_SHIFT | |
114 | ||
1da177e4 LT |
115 | /* |
116 | * These are the 'tuning knobs' of the scheduler: | |
117 | * | |
a4ec24b4 | 118 | * default timeslice is 100 msecs (used only for SCHED_RR tasks). |
1da177e4 LT |
119 | * Timeslices get refilled after they expire. |
120 | */ | |
1da177e4 | 121 | #define DEF_TIMESLICE (100 * HZ / 1000) |
2dd73a4f | 122 | |
d0b27fa7 PZ |
123 | /* |
124 | * single value that denotes runtime == period, ie unlimited time. | |
125 | */ | |
126 | #define RUNTIME_INF ((u64)~0ULL) | |
127 | ||
e05606d3 IM |
128 | static inline int rt_policy(int policy) |
129 | { | |
63f01241 | 130 | if (policy == SCHED_FIFO || policy == SCHED_RR) |
e05606d3 IM |
131 | return 1; |
132 | return 0; | |
133 | } | |
134 | ||
135 | static inline int task_has_rt_policy(struct task_struct *p) | |
136 | { | |
137 | return rt_policy(p->policy); | |
138 | } | |
139 | ||
1da177e4 | 140 | /* |
6aa645ea | 141 | * This is the priority-queue data structure of the RT scheduling class: |
1da177e4 | 142 | */ |
6aa645ea IM |
143 | struct rt_prio_array { |
144 | DECLARE_BITMAP(bitmap, MAX_RT_PRIO+1); /* include 1 bit for delimiter */ | |
145 | struct list_head queue[MAX_RT_PRIO]; | |
146 | }; | |
147 | ||
d0b27fa7 | 148 | struct rt_bandwidth { |
ea736ed5 | 149 | /* nests inside the rq lock: */ |
0986b11b | 150 | raw_spinlock_t rt_runtime_lock; |
ea736ed5 IM |
151 | ktime_t rt_period; |
152 | u64 rt_runtime; | |
153 | struct hrtimer rt_period_timer; | |
d0b27fa7 PZ |
154 | }; |
155 | ||
156 | static struct rt_bandwidth def_rt_bandwidth; | |
157 | ||
158 | static int do_sched_rt_period_timer(struct rt_bandwidth *rt_b, int overrun); | |
159 | ||
160 | static enum hrtimer_restart sched_rt_period_timer(struct hrtimer *timer) | |
161 | { | |
162 | struct rt_bandwidth *rt_b = | |
163 | container_of(timer, struct rt_bandwidth, rt_period_timer); | |
164 | ktime_t now; | |
165 | int overrun; | |
166 | int idle = 0; | |
167 | ||
168 | for (;;) { | |
169 | now = hrtimer_cb_get_time(timer); | |
170 | overrun = hrtimer_forward(timer, now, rt_b->rt_period); | |
171 | ||
172 | if (!overrun) | |
173 | break; | |
174 | ||
175 | idle = do_sched_rt_period_timer(rt_b, overrun); | |
176 | } | |
177 | ||
178 | return idle ? HRTIMER_NORESTART : HRTIMER_RESTART; | |
179 | } | |
180 | ||
181 | static | |
182 | void init_rt_bandwidth(struct rt_bandwidth *rt_b, u64 period, u64 runtime) | |
183 | { | |
184 | rt_b->rt_period = ns_to_ktime(period); | |
185 | rt_b->rt_runtime = runtime; | |
186 | ||
0986b11b | 187 | raw_spin_lock_init(&rt_b->rt_runtime_lock); |
ac086bc2 | 188 | |
d0b27fa7 PZ |
189 | hrtimer_init(&rt_b->rt_period_timer, |
190 | CLOCK_MONOTONIC, HRTIMER_MODE_REL); | |
191 | rt_b->rt_period_timer.function = sched_rt_period_timer; | |
d0b27fa7 PZ |
192 | } |
193 | ||
c8bfff6d KH |
194 | static inline int rt_bandwidth_enabled(void) |
195 | { | |
196 | return sysctl_sched_rt_runtime >= 0; | |
d0b27fa7 PZ |
197 | } |
198 | ||
199 | static void start_rt_bandwidth(struct rt_bandwidth *rt_b) | |
200 | { | |
201 | ktime_t now; | |
202 | ||
cac64d00 | 203 | if (!rt_bandwidth_enabled() || rt_b->rt_runtime == RUNTIME_INF) |
d0b27fa7 PZ |
204 | return; |
205 | ||
206 | if (hrtimer_active(&rt_b->rt_period_timer)) | |
207 | return; | |
208 | ||
0986b11b | 209 | raw_spin_lock(&rt_b->rt_runtime_lock); |
d0b27fa7 | 210 | for (;;) { |
7f1e2ca9 PZ |
211 | unsigned long delta; |
212 | ktime_t soft, hard; | |
213 | ||
d0b27fa7 PZ |
214 | if (hrtimer_active(&rt_b->rt_period_timer)) |
215 | break; | |
216 | ||
217 | now = hrtimer_cb_get_time(&rt_b->rt_period_timer); | |
218 | hrtimer_forward(&rt_b->rt_period_timer, now, rt_b->rt_period); | |
7f1e2ca9 PZ |
219 | |
220 | soft = hrtimer_get_softexpires(&rt_b->rt_period_timer); | |
221 | hard = hrtimer_get_expires(&rt_b->rt_period_timer); | |
222 | delta = ktime_to_ns(ktime_sub(hard, soft)); | |
223 | __hrtimer_start_range_ns(&rt_b->rt_period_timer, soft, delta, | |
5c333864 | 224 | HRTIMER_MODE_ABS_PINNED, 0); |
d0b27fa7 | 225 | } |
0986b11b | 226 | raw_spin_unlock(&rt_b->rt_runtime_lock); |
d0b27fa7 PZ |
227 | } |
228 | ||
229 | #ifdef CONFIG_RT_GROUP_SCHED | |
230 | static void destroy_rt_bandwidth(struct rt_bandwidth *rt_b) | |
231 | { | |
232 | hrtimer_cancel(&rt_b->rt_period_timer); | |
233 | } | |
234 | #endif | |
235 | ||
712555ee | 236 | /* |
c4a8849a | 237 | * sched_domains_mutex serializes calls to init_sched_domains, |
712555ee HC |
238 | * detach_destroy_domains and partition_sched_domains. |
239 | */ | |
240 | static DEFINE_MUTEX(sched_domains_mutex); | |
241 | ||
7c941438 | 242 | #ifdef CONFIG_CGROUP_SCHED |
29f59db3 | 243 | |
68318b8e SV |
244 | #include <linux/cgroup.h> |
245 | ||
29f59db3 SV |
246 | struct cfs_rq; |
247 | ||
6f505b16 PZ |
248 | static LIST_HEAD(task_groups); |
249 | ||
29f59db3 | 250 | /* task group related information */ |
4cf86d77 | 251 | struct task_group { |
68318b8e | 252 | struct cgroup_subsys_state css; |
6c415b92 | 253 | |
052f1dc7 | 254 | #ifdef CONFIG_FAIR_GROUP_SCHED |
29f59db3 SV |
255 | /* schedulable entities of this group on each cpu */ |
256 | struct sched_entity **se; | |
257 | /* runqueue "owned" by this group on each cpu */ | |
258 | struct cfs_rq **cfs_rq; | |
259 | unsigned long shares; | |
2069dd75 PZ |
260 | |
261 | atomic_t load_weight; | |
052f1dc7 PZ |
262 | #endif |
263 | ||
264 | #ifdef CONFIG_RT_GROUP_SCHED | |
265 | struct sched_rt_entity **rt_se; | |
266 | struct rt_rq **rt_rq; | |
267 | ||
d0b27fa7 | 268 | struct rt_bandwidth rt_bandwidth; |
052f1dc7 | 269 | #endif |
6b2d7700 | 270 | |
ae8393e5 | 271 | struct rcu_head rcu; |
6f505b16 | 272 | struct list_head list; |
f473aa5e PZ |
273 | |
274 | struct task_group *parent; | |
275 | struct list_head siblings; | |
276 | struct list_head children; | |
5091faa4 MG |
277 | |
278 | #ifdef CONFIG_SCHED_AUTOGROUP | |
279 | struct autogroup *autogroup; | |
280 | #endif | |
29f59db3 SV |
281 | }; |
282 | ||
3d4b47b4 | 283 | /* task_group_lock serializes the addition/removal of task groups */ |
8ed36996 | 284 | static DEFINE_SPINLOCK(task_group_lock); |
ec2c507f | 285 | |
e9036b36 CG |
286 | #ifdef CONFIG_FAIR_GROUP_SCHED |
287 | ||
07e06b01 | 288 | # define ROOT_TASK_GROUP_LOAD NICE_0_LOAD |
052f1dc7 | 289 | |
cb4ad1ff | 290 | /* |
2e084786 LJ |
291 | * A weight of 0 or 1 can cause arithmetics problems. |
292 | * A weight of a cfs_rq is the sum of weights of which entities | |
293 | * are queued on this cfs_rq, so a weight of a entity should not be | |
294 | * too large, so as the shares value of a task group. | |
cb4ad1ff MX |
295 | * (The default weight is 1024 - so there's no practical |
296 | * limitation from this.) | |
297 | */ | |
cd62287e MG |
298 | #define MIN_SHARES (1UL << 1) |
299 | #define MAX_SHARES (1UL << 18) | |
18d95a28 | 300 | |
07e06b01 | 301 | static int root_task_group_load = ROOT_TASK_GROUP_LOAD; |
052f1dc7 PZ |
302 | #endif |
303 | ||
29f59db3 | 304 | /* Default task group. |
3a252015 | 305 | * Every task in system belong to this group at bootup. |
29f59db3 | 306 | */ |
07e06b01 | 307 | struct task_group root_task_group; |
29f59db3 | 308 | |
7c941438 | 309 | #endif /* CONFIG_CGROUP_SCHED */ |
29f59db3 | 310 | |
6aa645ea IM |
311 | /* CFS-related fields in a runqueue */ |
312 | struct cfs_rq { | |
313 | struct load_weight load; | |
314 | unsigned long nr_running; | |
315 | ||
6aa645ea | 316 | u64 exec_clock; |
e9acbff6 | 317 | u64 min_vruntime; |
3fe1698b PZ |
318 | #ifndef CONFIG_64BIT |
319 | u64 min_vruntime_copy; | |
320 | #endif | |
6aa645ea IM |
321 | |
322 | struct rb_root tasks_timeline; | |
323 | struct rb_node *rb_leftmost; | |
4a55bd5e PZ |
324 | |
325 | struct list_head tasks; | |
326 | struct list_head *balance_iterator; | |
327 | ||
328 | /* | |
329 | * 'curr' points to currently running entity on this cfs_rq. | |
6aa645ea IM |
330 | * It is set to NULL otherwise (i.e when none are currently running). |
331 | */ | |
ac53db59 | 332 | struct sched_entity *curr, *next, *last, *skip; |
ddc97297 | 333 | |
4934a4d3 | 334 | #ifdef CONFIG_SCHED_DEBUG |
5ac5c4d6 | 335 | unsigned int nr_spread_over; |
4934a4d3 | 336 | #endif |
ddc97297 | 337 | |
62160e3f | 338 | #ifdef CONFIG_FAIR_GROUP_SCHED |
6aa645ea IM |
339 | struct rq *rq; /* cpu runqueue to which this cfs_rq is attached */ |
340 | ||
41a2d6cf IM |
341 | /* |
342 | * leaf cfs_rqs are those that hold tasks (lowest schedulable entity in | |
6aa645ea IM |
343 | * a hierarchy). Non-leaf lrqs hold other higher schedulable entities |
344 | * (like users, containers etc.) | |
345 | * | |
346 | * leaf_cfs_rq_list ties together list of leaf cfs_rq's in a cpu. This | |
347 | * list is used during load balance. | |
348 | */ | |
3d4b47b4 | 349 | int on_list; |
41a2d6cf IM |
350 | struct list_head leaf_cfs_rq_list; |
351 | struct task_group *tg; /* group that "owns" this runqueue */ | |
c09595f6 PZ |
352 | |
353 | #ifdef CONFIG_SMP | |
c09595f6 | 354 | /* |
c8cba857 | 355 | * the part of load.weight contributed by tasks |
c09595f6 | 356 | */ |
c8cba857 | 357 | unsigned long task_weight; |
c09595f6 | 358 | |
c8cba857 PZ |
359 | /* |
360 | * h_load = weight * f(tg) | |
361 | * | |
362 | * Where f(tg) is the recursive weight fraction assigned to | |
363 | * this group. | |
364 | */ | |
365 | unsigned long h_load; | |
c09595f6 | 366 | |
c8cba857 | 367 | /* |
3b3d190e PT |
368 | * Maintaining per-cpu shares distribution for group scheduling |
369 | * | |
370 | * load_stamp is the last time we updated the load average | |
371 | * load_last is the last time we updated the load average and saw load | |
372 | * load_unacc_exec_time is currently unaccounted execution time | |
c8cba857 | 373 | */ |
2069dd75 PZ |
374 | u64 load_avg; |
375 | u64 load_period; | |
3b3d190e | 376 | u64 load_stamp, load_last, load_unacc_exec_time; |
f1d239f7 | 377 | |
2069dd75 | 378 | unsigned long load_contribution; |
c09595f6 | 379 | #endif |
6aa645ea IM |
380 | #endif |
381 | }; | |
1da177e4 | 382 | |
6aa645ea IM |
383 | /* Real-Time classes' related field in a runqueue: */ |
384 | struct rt_rq { | |
385 | struct rt_prio_array active; | |
63489e45 | 386 | unsigned long rt_nr_running; |
052f1dc7 | 387 | #if defined CONFIG_SMP || defined CONFIG_RT_GROUP_SCHED |
e864c499 GH |
388 | struct { |
389 | int curr; /* highest queued rt task prio */ | |
398a153b | 390 | #ifdef CONFIG_SMP |
e864c499 | 391 | int next; /* next highest */ |
398a153b | 392 | #endif |
e864c499 | 393 | } highest_prio; |
6f505b16 | 394 | #endif |
fa85ae24 | 395 | #ifdef CONFIG_SMP |
73fe6aae | 396 | unsigned long rt_nr_migratory; |
a1ba4d8b | 397 | unsigned long rt_nr_total; |
a22d7fc1 | 398 | int overloaded; |
917b627d | 399 | struct plist_head pushable_tasks; |
fa85ae24 | 400 | #endif |
6f505b16 | 401 | int rt_throttled; |
fa85ae24 | 402 | u64 rt_time; |
ac086bc2 | 403 | u64 rt_runtime; |
ea736ed5 | 404 | /* Nests inside the rq lock: */ |
0986b11b | 405 | raw_spinlock_t rt_runtime_lock; |
6f505b16 | 406 | |
052f1dc7 | 407 | #ifdef CONFIG_RT_GROUP_SCHED |
23b0fdfc PZ |
408 | unsigned long rt_nr_boosted; |
409 | ||
6f505b16 PZ |
410 | struct rq *rq; |
411 | struct list_head leaf_rt_rq_list; | |
412 | struct task_group *tg; | |
6f505b16 | 413 | #endif |
6aa645ea IM |
414 | }; |
415 | ||
57d885fe GH |
416 | #ifdef CONFIG_SMP |
417 | ||
418 | /* | |
419 | * We add the notion of a root-domain which will be used to define per-domain | |
0eab9146 IM |
420 | * variables. Each exclusive cpuset essentially defines an island domain by |
421 | * fully partitioning the member cpus from any other cpuset. Whenever a new | |
57d885fe GH |
422 | * exclusive cpuset is created, we also create and attach a new root-domain |
423 | * object. | |
424 | * | |
57d885fe GH |
425 | */ |
426 | struct root_domain { | |
427 | atomic_t refcount; | |
26a148eb | 428 | atomic_t rto_count; |
dce840a0 | 429 | struct rcu_head rcu; |
c6c4927b RR |
430 | cpumask_var_t span; |
431 | cpumask_var_t online; | |
637f5085 | 432 | |
0eab9146 | 433 | /* |
637f5085 GH |
434 | * The "RT overload" flag: it gets set if a CPU has more than |
435 | * one runnable RT task. | |
436 | */ | |
c6c4927b | 437 | cpumask_var_t rto_mask; |
6e0534f2 | 438 | struct cpupri cpupri; |
57d885fe GH |
439 | }; |
440 | ||
dc938520 GH |
441 | /* |
442 | * By default the system creates a single root-domain with all cpus as | |
443 | * members (mimicking the global state we have today). | |
444 | */ | |
57d885fe GH |
445 | static struct root_domain def_root_domain; |
446 | ||
ed2d372c | 447 | #endif /* CONFIG_SMP */ |
57d885fe | 448 | |
1da177e4 LT |
449 | /* |
450 | * This is the main, per-CPU runqueue data structure. | |
451 | * | |
452 | * Locking rule: those places that want to lock multiple runqueues | |
453 | * (such as the load balancing or the thread migration code), lock | |
454 | * acquire operations must be ordered by ascending &runqueue. | |
455 | */ | |
70b97a7f | 456 | struct rq { |
d8016491 | 457 | /* runqueue lock: */ |
05fa785c | 458 | raw_spinlock_t lock; |
1da177e4 LT |
459 | |
460 | /* | |
461 | * nr_running and cpu_load should be in the same cacheline because | |
462 | * remote CPUs use both these fields when doing load calculation. | |
463 | */ | |
464 | unsigned long nr_running; | |
6aa645ea IM |
465 | #define CPU_LOAD_IDX_MAX 5 |
466 | unsigned long cpu_load[CPU_LOAD_IDX_MAX]; | |
fdf3e95d | 467 | unsigned long last_load_update_tick; |
46cb4b7c | 468 | #ifdef CONFIG_NO_HZ |
39c0cbe2 | 469 | u64 nohz_stamp; |
83cd4fe2 | 470 | unsigned char nohz_balance_kick; |
46cb4b7c | 471 | #endif |
61eadef6 | 472 | int skip_clock_update; |
a64692a3 | 473 | |
d8016491 IM |
474 | /* capture load from *all* tasks on this cpu: */ |
475 | struct load_weight load; | |
6aa645ea IM |
476 | unsigned long nr_load_updates; |
477 | u64 nr_switches; | |
478 | ||
479 | struct cfs_rq cfs; | |
6f505b16 | 480 | struct rt_rq rt; |
6f505b16 | 481 | |
6aa645ea | 482 | #ifdef CONFIG_FAIR_GROUP_SCHED |
d8016491 IM |
483 | /* list of leaf cfs_rq on this cpu: */ |
484 | struct list_head leaf_cfs_rq_list; | |
052f1dc7 PZ |
485 | #endif |
486 | #ifdef CONFIG_RT_GROUP_SCHED | |
6f505b16 | 487 | struct list_head leaf_rt_rq_list; |
1da177e4 | 488 | #endif |
1da177e4 LT |
489 | |
490 | /* | |
491 | * This is part of a global counter where only the total sum | |
492 | * over all CPUs matters. A task can increase this counter on | |
493 | * one CPU and if it got migrated afterwards it may decrease | |
494 | * it on another CPU. Always updated under the runqueue lock: | |
495 | */ | |
496 | unsigned long nr_uninterruptible; | |
497 | ||
34f971f6 | 498 | struct task_struct *curr, *idle, *stop; |
c9819f45 | 499 | unsigned long next_balance; |
1da177e4 | 500 | struct mm_struct *prev_mm; |
6aa645ea | 501 | |
3e51f33f | 502 | u64 clock; |
305e6835 | 503 | u64 clock_task; |
6aa645ea | 504 | |
1da177e4 LT |
505 | atomic_t nr_iowait; |
506 | ||
507 | #ifdef CONFIG_SMP | |
0eab9146 | 508 | struct root_domain *rd; |
1da177e4 LT |
509 | struct sched_domain *sd; |
510 | ||
e51fd5e2 PZ |
511 | unsigned long cpu_power; |
512 | ||
a0a522ce | 513 | unsigned char idle_at_tick; |
1da177e4 | 514 | /* For active balancing */ |
3f029d3c | 515 | int post_schedule; |
1da177e4 LT |
516 | int active_balance; |
517 | int push_cpu; | |
969c7921 | 518 | struct cpu_stop_work active_balance_work; |
d8016491 IM |
519 | /* cpu of this runqueue: */ |
520 | int cpu; | |
1f11eb6a | 521 | int online; |
1da177e4 | 522 | |
a8a51d5e | 523 | unsigned long avg_load_per_task; |
1da177e4 | 524 | |
e9e9250b PZ |
525 | u64 rt_avg; |
526 | u64 age_stamp; | |
1b9508f6 MG |
527 | u64 idle_stamp; |
528 | u64 avg_idle; | |
1da177e4 LT |
529 | #endif |
530 | ||
aa483808 VP |
531 | #ifdef CONFIG_IRQ_TIME_ACCOUNTING |
532 | u64 prev_irq_time; | |
533 | #endif | |
e6e6685a GC |
534 | #ifdef CONFIG_PARAVIRT |
535 | u64 prev_steal_time; | |
536 | #endif | |
095c0aa8 GC |
537 | #ifdef CONFIG_PARAVIRT_TIME_ACCOUNTING |
538 | u64 prev_steal_time_rq; | |
539 | #endif | |
aa483808 | 540 | |
dce48a84 TG |
541 | /* calc_load related fields */ |
542 | unsigned long calc_load_update; | |
543 | long calc_load_active; | |
544 | ||
8f4d37ec | 545 | #ifdef CONFIG_SCHED_HRTICK |
31656519 PZ |
546 | #ifdef CONFIG_SMP |
547 | int hrtick_csd_pending; | |
548 | struct call_single_data hrtick_csd; | |
549 | #endif | |
8f4d37ec PZ |
550 | struct hrtimer hrtick_timer; |
551 | #endif | |
552 | ||
1da177e4 LT |
553 | #ifdef CONFIG_SCHEDSTATS |
554 | /* latency stats */ | |
555 | struct sched_info rq_sched_info; | |
9c2c4802 KC |
556 | unsigned long long rq_cpu_time; |
557 | /* could above be rq->cfs_rq.exec_clock + rq->rt_rq.rt_runtime ? */ | |
1da177e4 LT |
558 | |
559 | /* sys_sched_yield() stats */ | |
480b9434 | 560 | unsigned int yld_count; |
1da177e4 LT |
561 | |
562 | /* schedule() stats */ | |
480b9434 KC |
563 | unsigned int sched_switch; |
564 | unsigned int sched_count; | |
565 | unsigned int sched_goidle; | |
1da177e4 LT |
566 | |
567 | /* try_to_wake_up() stats */ | |
480b9434 KC |
568 | unsigned int ttwu_count; |
569 | unsigned int ttwu_local; | |
1da177e4 | 570 | #endif |
317f3941 PZ |
571 | |
572 | #ifdef CONFIG_SMP | |
573 | struct task_struct *wake_list; | |
574 | #endif | |
1da177e4 LT |
575 | }; |
576 | ||
f34e3b61 | 577 | static DEFINE_PER_CPU_SHARED_ALIGNED(struct rq, runqueues); |
1da177e4 | 578 | |
a64692a3 | 579 | |
1e5a7405 | 580 | static void check_preempt_curr(struct rq *rq, struct task_struct *p, int flags); |
dd41f596 | 581 | |
0a2966b4 CL |
582 | static inline int cpu_of(struct rq *rq) |
583 | { | |
584 | #ifdef CONFIG_SMP | |
585 | return rq->cpu; | |
586 | #else | |
587 | return 0; | |
588 | #endif | |
589 | } | |
590 | ||
497f0ab3 | 591 | #define rcu_dereference_check_sched_domain(p) \ |
d11c563d | 592 | rcu_dereference_check((p), \ |
d11c563d PM |
593 | lockdep_is_held(&sched_domains_mutex)) |
594 | ||
674311d5 NP |
595 | /* |
596 | * The domain tree (rq->sd) is protected by RCU's quiescent state transition. | |
1a20ff27 | 597 | * See detach_destroy_domains: synchronize_sched for details. |
674311d5 NP |
598 | * |
599 | * The domain tree of any CPU may only be accessed from within | |
600 | * preempt-disabled sections. | |
601 | */ | |
48f24c4d | 602 | #define for_each_domain(cpu, __sd) \ |
497f0ab3 | 603 | for (__sd = rcu_dereference_check_sched_domain(cpu_rq(cpu)->sd); __sd; __sd = __sd->parent) |
1da177e4 LT |
604 | |
605 | #define cpu_rq(cpu) (&per_cpu(runqueues, (cpu))) | |
606 | #define this_rq() (&__get_cpu_var(runqueues)) | |
607 | #define task_rq(p) cpu_rq(task_cpu(p)) | |
608 | #define cpu_curr(cpu) (cpu_rq(cpu)->curr) | |
54d35f29 | 609 | #define raw_rq() (&__raw_get_cpu_var(runqueues)) |
1da177e4 | 610 | |
dc61b1d6 PZ |
611 | #ifdef CONFIG_CGROUP_SCHED |
612 | ||
613 | /* | |
614 | * Return the group to which this tasks belongs. | |
615 | * | |
6c6c54e1 PZ |
616 | * We use task_subsys_state_check() and extend the RCU verification with |
617 | * pi->lock and rq->lock because cpu_cgroup_attach() holds those locks for each | |
618 | * task it moves into the cgroup. Therefore by holding either of those locks, | |
619 | * we pin the task to the current cgroup. | |
dc61b1d6 PZ |
620 | */ |
621 | static inline struct task_group *task_group(struct task_struct *p) | |
622 | { | |
5091faa4 | 623 | struct task_group *tg; |
dc61b1d6 PZ |
624 | struct cgroup_subsys_state *css; |
625 | ||
626 | css = task_subsys_state_check(p, cpu_cgroup_subsys_id, | |
6c6c54e1 PZ |
627 | lockdep_is_held(&p->pi_lock) || |
628 | lockdep_is_held(&task_rq(p)->lock)); | |
5091faa4 MG |
629 | tg = container_of(css, struct task_group, css); |
630 | ||
631 | return autogroup_task_group(p, tg); | |
dc61b1d6 PZ |
632 | } |
633 | ||
634 | /* Change a task's cfs_rq and parent entity if it moves across CPUs/groups */ | |
635 | static inline void set_task_rq(struct task_struct *p, unsigned int cpu) | |
636 | { | |
637 | #ifdef CONFIG_FAIR_GROUP_SCHED | |
638 | p->se.cfs_rq = task_group(p)->cfs_rq[cpu]; | |
639 | p->se.parent = task_group(p)->se[cpu]; | |
640 | #endif | |
641 | ||
642 | #ifdef CONFIG_RT_GROUP_SCHED | |
643 | p->rt.rt_rq = task_group(p)->rt_rq[cpu]; | |
644 | p->rt.parent = task_group(p)->rt_se[cpu]; | |
645 | #endif | |
646 | } | |
647 | ||
648 | #else /* CONFIG_CGROUP_SCHED */ | |
649 | ||
650 | static inline void set_task_rq(struct task_struct *p, unsigned int cpu) { } | |
651 | static inline struct task_group *task_group(struct task_struct *p) | |
652 | { | |
653 | return NULL; | |
654 | } | |
655 | ||
656 | #endif /* CONFIG_CGROUP_SCHED */ | |
657 | ||
fe44d621 | 658 | static void update_rq_clock_task(struct rq *rq, s64 delta); |
305e6835 | 659 | |
fe44d621 | 660 | static void update_rq_clock(struct rq *rq) |
3e51f33f | 661 | { |
fe44d621 | 662 | s64 delta; |
305e6835 | 663 | |
61eadef6 | 664 | if (rq->skip_clock_update > 0) |
f26f9aff | 665 | return; |
aa483808 | 666 | |
fe44d621 PZ |
667 | delta = sched_clock_cpu(cpu_of(rq)) - rq->clock; |
668 | rq->clock += delta; | |
669 | update_rq_clock_task(rq, delta); | |
3e51f33f PZ |
670 | } |
671 | ||
bf5c91ba IM |
672 | /* |
673 | * Tunables that become constants when CONFIG_SCHED_DEBUG is off: | |
674 | */ | |
675 | #ifdef CONFIG_SCHED_DEBUG | |
676 | # define const_debug __read_mostly | |
677 | #else | |
678 | # define const_debug static const | |
679 | #endif | |
680 | ||
017730c1 | 681 | /** |
1fd06bb1 | 682 | * runqueue_is_locked - Returns true if the current cpu runqueue is locked |
e17b38bf | 683 | * @cpu: the processor in question. |
017730c1 | 684 | * |
017730c1 IM |
685 | * This interface allows printk to be called with the runqueue lock |
686 | * held and know whether or not it is OK to wake up the klogd. | |
687 | */ | |
89f19f04 | 688 | int runqueue_is_locked(int cpu) |
017730c1 | 689 | { |
05fa785c | 690 | return raw_spin_is_locked(&cpu_rq(cpu)->lock); |
017730c1 IM |
691 | } |
692 | ||
bf5c91ba IM |
693 | /* |
694 | * Debugging: various feature bits | |
695 | */ | |
f00b45c1 PZ |
696 | |
697 | #define SCHED_FEAT(name, enabled) \ | |
698 | __SCHED_FEAT_##name , | |
699 | ||
bf5c91ba | 700 | enum { |
f00b45c1 | 701 | #include "sched_features.h" |
bf5c91ba IM |
702 | }; |
703 | ||
f00b45c1 PZ |
704 | #undef SCHED_FEAT |
705 | ||
706 | #define SCHED_FEAT(name, enabled) \ | |
707 | (1UL << __SCHED_FEAT_##name) * enabled | | |
708 | ||
bf5c91ba | 709 | const_debug unsigned int sysctl_sched_features = |
f00b45c1 PZ |
710 | #include "sched_features.h" |
711 | 0; | |
712 | ||
713 | #undef SCHED_FEAT | |
714 | ||
715 | #ifdef CONFIG_SCHED_DEBUG | |
716 | #define SCHED_FEAT(name, enabled) \ | |
717 | #name , | |
718 | ||
983ed7a6 | 719 | static __read_mostly char *sched_feat_names[] = { |
f00b45c1 PZ |
720 | #include "sched_features.h" |
721 | NULL | |
722 | }; | |
723 | ||
724 | #undef SCHED_FEAT | |
725 | ||
34f3a814 | 726 | static int sched_feat_show(struct seq_file *m, void *v) |
f00b45c1 | 727 | { |
f00b45c1 PZ |
728 | int i; |
729 | ||
730 | for (i = 0; sched_feat_names[i]; i++) { | |
34f3a814 LZ |
731 | if (!(sysctl_sched_features & (1UL << i))) |
732 | seq_puts(m, "NO_"); | |
733 | seq_printf(m, "%s ", sched_feat_names[i]); | |
f00b45c1 | 734 | } |
34f3a814 | 735 | seq_puts(m, "\n"); |
f00b45c1 | 736 | |
34f3a814 | 737 | return 0; |
f00b45c1 PZ |
738 | } |
739 | ||
740 | static ssize_t | |
741 | sched_feat_write(struct file *filp, const char __user *ubuf, | |
742 | size_t cnt, loff_t *ppos) | |
743 | { | |
744 | char buf[64]; | |
7740191c | 745 | char *cmp; |
f00b45c1 PZ |
746 | int neg = 0; |
747 | int i; | |
748 | ||
749 | if (cnt > 63) | |
750 | cnt = 63; | |
751 | ||
752 | if (copy_from_user(&buf, ubuf, cnt)) | |
753 | return -EFAULT; | |
754 | ||
755 | buf[cnt] = 0; | |
7740191c | 756 | cmp = strstrip(buf); |
f00b45c1 | 757 | |
524429c3 | 758 | if (strncmp(cmp, "NO_", 3) == 0) { |
f00b45c1 PZ |
759 | neg = 1; |
760 | cmp += 3; | |
761 | } | |
762 | ||
763 | for (i = 0; sched_feat_names[i]; i++) { | |
7740191c | 764 | if (strcmp(cmp, sched_feat_names[i]) == 0) { |
f00b45c1 PZ |
765 | if (neg) |
766 | sysctl_sched_features &= ~(1UL << i); | |
767 | else | |
768 | sysctl_sched_features |= (1UL << i); | |
769 | break; | |
770 | } | |
771 | } | |
772 | ||
773 | if (!sched_feat_names[i]) | |
774 | return -EINVAL; | |
775 | ||
42994724 | 776 | *ppos += cnt; |
f00b45c1 PZ |
777 | |
778 | return cnt; | |
779 | } | |
780 | ||
34f3a814 LZ |
781 | static int sched_feat_open(struct inode *inode, struct file *filp) |
782 | { | |
783 | return single_open(filp, sched_feat_show, NULL); | |
784 | } | |
785 | ||
828c0950 | 786 | static const struct file_operations sched_feat_fops = { |
34f3a814 LZ |
787 | .open = sched_feat_open, |
788 | .write = sched_feat_write, | |
789 | .read = seq_read, | |
790 | .llseek = seq_lseek, | |
791 | .release = single_release, | |
f00b45c1 PZ |
792 | }; |
793 | ||
794 | static __init int sched_init_debug(void) | |
795 | { | |
f00b45c1 PZ |
796 | debugfs_create_file("sched_features", 0644, NULL, NULL, |
797 | &sched_feat_fops); | |
798 | ||
799 | return 0; | |
800 | } | |
801 | late_initcall(sched_init_debug); | |
802 | ||
803 | #endif | |
804 | ||
805 | #define sched_feat(x) (sysctl_sched_features & (1UL << __SCHED_FEAT_##x)) | |
bf5c91ba | 806 | |
b82d9fdd PZ |
807 | /* |
808 | * Number of tasks to iterate in a single balance run. | |
809 | * Limited because this is done with IRQs disabled. | |
810 | */ | |
811 | const_debug unsigned int sysctl_sched_nr_migrate = 32; | |
812 | ||
e9e9250b PZ |
813 | /* |
814 | * period over which we average the RT time consumption, measured | |
815 | * in ms. | |
816 | * | |
817 | * default: 1s | |
818 | */ | |
819 | const_debug unsigned int sysctl_sched_time_avg = MSEC_PER_SEC; | |
820 | ||
fa85ae24 | 821 | /* |
9f0c1e56 | 822 | * period over which we measure -rt task cpu usage in us. |
fa85ae24 PZ |
823 | * default: 1s |
824 | */ | |
9f0c1e56 | 825 | unsigned int sysctl_sched_rt_period = 1000000; |
fa85ae24 | 826 | |
6892b75e IM |
827 | static __read_mostly int scheduler_running; |
828 | ||
9f0c1e56 PZ |
829 | /* |
830 | * part of the period that we allow rt tasks to run in us. | |
831 | * default: 0.95s | |
832 | */ | |
833 | int sysctl_sched_rt_runtime = 950000; | |
fa85ae24 | 834 | |
d0b27fa7 PZ |
835 | static inline u64 global_rt_period(void) |
836 | { | |
837 | return (u64)sysctl_sched_rt_period * NSEC_PER_USEC; | |
838 | } | |
839 | ||
840 | static inline u64 global_rt_runtime(void) | |
841 | { | |
e26873bb | 842 | if (sysctl_sched_rt_runtime < 0) |
d0b27fa7 PZ |
843 | return RUNTIME_INF; |
844 | ||
845 | return (u64)sysctl_sched_rt_runtime * NSEC_PER_USEC; | |
846 | } | |
fa85ae24 | 847 | |
1da177e4 | 848 | #ifndef prepare_arch_switch |
4866cde0 NP |
849 | # define prepare_arch_switch(next) do { } while (0) |
850 | #endif | |
851 | #ifndef finish_arch_switch | |
852 | # define finish_arch_switch(prev) do { } while (0) | |
853 | #endif | |
854 | ||
051a1d1a DA |
855 | static inline int task_current(struct rq *rq, struct task_struct *p) |
856 | { | |
857 | return rq->curr == p; | |
858 | } | |
859 | ||
70b97a7f | 860 | static inline int task_running(struct rq *rq, struct task_struct *p) |
4866cde0 | 861 | { |
3ca7a440 PZ |
862 | #ifdef CONFIG_SMP |
863 | return p->on_cpu; | |
864 | #else | |
051a1d1a | 865 | return task_current(rq, p); |
3ca7a440 | 866 | #endif |
4866cde0 NP |
867 | } |
868 | ||
3ca7a440 | 869 | #ifndef __ARCH_WANT_UNLOCKED_CTXSW |
70b97a7f | 870 | static inline void prepare_lock_switch(struct rq *rq, struct task_struct *next) |
4866cde0 | 871 | { |
3ca7a440 PZ |
872 | #ifdef CONFIG_SMP |
873 | /* | |
874 | * We can optimise this out completely for !SMP, because the | |
875 | * SMP rebalancing from interrupt is the only thing that cares | |
876 | * here. | |
877 | */ | |
878 | next->on_cpu = 1; | |
879 | #endif | |
4866cde0 NP |
880 | } |
881 | ||
70b97a7f | 882 | static inline void finish_lock_switch(struct rq *rq, struct task_struct *prev) |
4866cde0 | 883 | { |
3ca7a440 PZ |
884 | #ifdef CONFIG_SMP |
885 | /* | |
886 | * After ->on_cpu is cleared, the task can be moved to a different CPU. | |
887 | * We must ensure this doesn't happen until the switch is completely | |
888 | * finished. | |
889 | */ | |
890 | smp_wmb(); | |
891 | prev->on_cpu = 0; | |
892 | #endif | |
da04c035 IM |
893 | #ifdef CONFIG_DEBUG_SPINLOCK |
894 | /* this is a valid case when another task releases the spinlock */ | |
895 | rq->lock.owner = current; | |
896 | #endif | |
8a25d5de IM |
897 | /* |
898 | * If we are tracking spinlock dependencies then we have to | |
899 | * fix up the runqueue lock - which gets 'carried over' from | |
900 | * prev into current: | |
901 | */ | |
902 | spin_acquire(&rq->lock.dep_map, 0, 0, _THIS_IP_); | |
903 | ||
05fa785c | 904 | raw_spin_unlock_irq(&rq->lock); |
4866cde0 NP |
905 | } |
906 | ||
907 | #else /* __ARCH_WANT_UNLOCKED_CTXSW */ | |
70b97a7f | 908 | static inline void prepare_lock_switch(struct rq *rq, struct task_struct *next) |
4866cde0 NP |
909 | { |
910 | #ifdef CONFIG_SMP | |
911 | /* | |
912 | * We can optimise this out completely for !SMP, because the | |
913 | * SMP rebalancing from interrupt is the only thing that cares | |
914 | * here. | |
915 | */ | |
3ca7a440 | 916 | next->on_cpu = 1; |
4866cde0 NP |
917 | #endif |
918 | #ifdef __ARCH_WANT_INTERRUPTS_ON_CTXSW | |
05fa785c | 919 | raw_spin_unlock_irq(&rq->lock); |
4866cde0 | 920 | #else |
05fa785c | 921 | raw_spin_unlock(&rq->lock); |
4866cde0 NP |
922 | #endif |
923 | } | |
924 | ||
70b97a7f | 925 | static inline void finish_lock_switch(struct rq *rq, struct task_struct *prev) |
4866cde0 NP |
926 | { |
927 | #ifdef CONFIG_SMP | |
928 | /* | |
3ca7a440 | 929 | * After ->on_cpu is cleared, the task can be moved to a different CPU. |
4866cde0 NP |
930 | * We must ensure this doesn't happen until the switch is completely |
931 | * finished. | |
932 | */ | |
933 | smp_wmb(); | |
3ca7a440 | 934 | prev->on_cpu = 0; |
4866cde0 NP |
935 | #endif |
936 | #ifndef __ARCH_WANT_INTERRUPTS_ON_CTXSW | |
937 | local_irq_enable(); | |
1da177e4 | 938 | #endif |
4866cde0 NP |
939 | } |
940 | #endif /* __ARCH_WANT_UNLOCKED_CTXSW */ | |
1da177e4 | 941 | |
0970d299 | 942 | /* |
0122ec5b | 943 | * __task_rq_lock - lock the rq @p resides on. |
b29739f9 | 944 | */ |
70b97a7f | 945 | static inline struct rq *__task_rq_lock(struct task_struct *p) |
b29739f9 IM |
946 | __acquires(rq->lock) |
947 | { | |
0970d299 PZ |
948 | struct rq *rq; |
949 | ||
0122ec5b PZ |
950 | lockdep_assert_held(&p->pi_lock); |
951 | ||
3a5c359a | 952 | for (;;) { |
0970d299 | 953 | rq = task_rq(p); |
05fa785c | 954 | raw_spin_lock(&rq->lock); |
65cc8e48 | 955 | if (likely(rq == task_rq(p))) |
3a5c359a | 956 | return rq; |
05fa785c | 957 | raw_spin_unlock(&rq->lock); |
b29739f9 | 958 | } |
b29739f9 IM |
959 | } |
960 | ||
1da177e4 | 961 | /* |
0122ec5b | 962 | * task_rq_lock - lock p->pi_lock and lock the rq @p resides on. |
1da177e4 | 963 | */ |
70b97a7f | 964 | static struct rq *task_rq_lock(struct task_struct *p, unsigned long *flags) |
0122ec5b | 965 | __acquires(p->pi_lock) |
1da177e4 LT |
966 | __acquires(rq->lock) |
967 | { | |
70b97a7f | 968 | struct rq *rq; |
1da177e4 | 969 | |
3a5c359a | 970 | for (;;) { |
0122ec5b | 971 | raw_spin_lock_irqsave(&p->pi_lock, *flags); |
3a5c359a | 972 | rq = task_rq(p); |
05fa785c | 973 | raw_spin_lock(&rq->lock); |
65cc8e48 | 974 | if (likely(rq == task_rq(p))) |
3a5c359a | 975 | return rq; |
0122ec5b PZ |
976 | raw_spin_unlock(&rq->lock); |
977 | raw_spin_unlock_irqrestore(&p->pi_lock, *flags); | |
1da177e4 | 978 | } |
1da177e4 LT |
979 | } |
980 | ||
a9957449 | 981 | static void __task_rq_unlock(struct rq *rq) |
b29739f9 IM |
982 | __releases(rq->lock) |
983 | { | |
05fa785c | 984 | raw_spin_unlock(&rq->lock); |
b29739f9 IM |
985 | } |
986 | ||
0122ec5b PZ |
987 | static inline void |
988 | task_rq_unlock(struct rq *rq, struct task_struct *p, unsigned long *flags) | |
1da177e4 | 989 | __releases(rq->lock) |
0122ec5b | 990 | __releases(p->pi_lock) |
1da177e4 | 991 | { |
0122ec5b PZ |
992 | raw_spin_unlock(&rq->lock); |
993 | raw_spin_unlock_irqrestore(&p->pi_lock, *flags); | |
1da177e4 LT |
994 | } |
995 | ||
1da177e4 | 996 | /* |
cc2a73b5 | 997 | * this_rq_lock - lock this runqueue and disable interrupts. |
1da177e4 | 998 | */ |
a9957449 | 999 | static struct rq *this_rq_lock(void) |
1da177e4 LT |
1000 | __acquires(rq->lock) |
1001 | { | |
70b97a7f | 1002 | struct rq *rq; |
1da177e4 LT |
1003 | |
1004 | local_irq_disable(); | |
1005 | rq = this_rq(); | |
05fa785c | 1006 | raw_spin_lock(&rq->lock); |
1da177e4 LT |
1007 | |
1008 | return rq; | |
1009 | } | |
1010 | ||
8f4d37ec PZ |
1011 | #ifdef CONFIG_SCHED_HRTICK |
1012 | /* | |
1013 | * Use HR-timers to deliver accurate preemption points. | |
1014 | * | |
1015 | * Its all a bit involved since we cannot program an hrt while holding the | |
1016 | * rq->lock. So what we do is store a state in in rq->hrtick_* and ask for a | |
1017 | * reschedule event. | |
1018 | * | |
1019 | * When we get rescheduled we reprogram the hrtick_timer outside of the | |
1020 | * rq->lock. | |
1021 | */ | |
8f4d37ec PZ |
1022 | |
1023 | /* | |
1024 | * Use hrtick when: | |
1025 | * - enabled by features | |
1026 | * - hrtimer is actually high res | |
1027 | */ | |
1028 | static inline int hrtick_enabled(struct rq *rq) | |
1029 | { | |
1030 | if (!sched_feat(HRTICK)) | |
1031 | return 0; | |
ba42059f | 1032 | if (!cpu_active(cpu_of(rq))) |
b328ca18 | 1033 | return 0; |
8f4d37ec PZ |
1034 | return hrtimer_is_hres_active(&rq->hrtick_timer); |
1035 | } | |
1036 | ||
8f4d37ec PZ |
1037 | static void hrtick_clear(struct rq *rq) |
1038 | { | |
1039 | if (hrtimer_active(&rq->hrtick_timer)) | |
1040 | hrtimer_cancel(&rq->hrtick_timer); | |
1041 | } | |
1042 | ||
8f4d37ec PZ |
1043 | /* |
1044 | * High-resolution timer tick. | |
1045 | * Runs from hardirq context with interrupts disabled. | |
1046 | */ | |
1047 | static enum hrtimer_restart hrtick(struct hrtimer *timer) | |
1048 | { | |
1049 | struct rq *rq = container_of(timer, struct rq, hrtick_timer); | |
1050 | ||
1051 | WARN_ON_ONCE(cpu_of(rq) != smp_processor_id()); | |
1052 | ||
05fa785c | 1053 | raw_spin_lock(&rq->lock); |
3e51f33f | 1054 | update_rq_clock(rq); |
8f4d37ec | 1055 | rq->curr->sched_class->task_tick(rq, rq->curr, 1); |
05fa785c | 1056 | raw_spin_unlock(&rq->lock); |
8f4d37ec PZ |
1057 | |
1058 | return HRTIMER_NORESTART; | |
1059 | } | |
1060 | ||
95e904c7 | 1061 | #ifdef CONFIG_SMP |
31656519 PZ |
1062 | /* |
1063 | * called from hardirq (IPI) context | |
1064 | */ | |
1065 | static void __hrtick_start(void *arg) | |
b328ca18 | 1066 | { |
31656519 | 1067 | struct rq *rq = arg; |
b328ca18 | 1068 | |
05fa785c | 1069 | raw_spin_lock(&rq->lock); |
31656519 PZ |
1070 | hrtimer_restart(&rq->hrtick_timer); |
1071 | rq->hrtick_csd_pending = 0; | |
05fa785c | 1072 | raw_spin_unlock(&rq->lock); |
b328ca18 PZ |
1073 | } |
1074 | ||
31656519 PZ |
1075 | /* |
1076 | * Called to set the hrtick timer state. | |
1077 | * | |
1078 | * called with rq->lock held and irqs disabled | |
1079 | */ | |
1080 | static void hrtick_start(struct rq *rq, u64 delay) | |
b328ca18 | 1081 | { |
31656519 PZ |
1082 | struct hrtimer *timer = &rq->hrtick_timer; |
1083 | ktime_t time = ktime_add_ns(timer->base->get_time(), delay); | |
b328ca18 | 1084 | |
cc584b21 | 1085 | hrtimer_set_expires(timer, time); |
31656519 PZ |
1086 | |
1087 | if (rq == this_rq()) { | |
1088 | hrtimer_restart(timer); | |
1089 | } else if (!rq->hrtick_csd_pending) { | |
6e275637 | 1090 | __smp_call_function_single(cpu_of(rq), &rq->hrtick_csd, 0); |
31656519 PZ |
1091 | rq->hrtick_csd_pending = 1; |
1092 | } | |
b328ca18 PZ |
1093 | } |
1094 | ||
1095 | static int | |
1096 | hotplug_hrtick(struct notifier_block *nfb, unsigned long action, void *hcpu) | |
1097 | { | |
1098 | int cpu = (int)(long)hcpu; | |
1099 | ||
1100 | switch (action) { | |
1101 | case CPU_UP_CANCELED: | |
1102 | case CPU_UP_CANCELED_FROZEN: | |
1103 | case CPU_DOWN_PREPARE: | |
1104 | case CPU_DOWN_PREPARE_FROZEN: | |
1105 | case CPU_DEAD: | |
1106 | case CPU_DEAD_FROZEN: | |
31656519 | 1107 | hrtick_clear(cpu_rq(cpu)); |
b328ca18 PZ |
1108 | return NOTIFY_OK; |
1109 | } | |
1110 | ||
1111 | return NOTIFY_DONE; | |
1112 | } | |
1113 | ||
fa748203 | 1114 | static __init void init_hrtick(void) |
b328ca18 PZ |
1115 | { |
1116 | hotcpu_notifier(hotplug_hrtick, 0); | |
1117 | } | |
31656519 PZ |
1118 | #else |
1119 | /* | |
1120 | * Called to set the hrtick timer state. | |
1121 | * | |
1122 | * called with rq->lock held and irqs disabled | |
1123 | */ | |
1124 | static void hrtick_start(struct rq *rq, u64 delay) | |
1125 | { | |
7f1e2ca9 | 1126 | __hrtimer_start_range_ns(&rq->hrtick_timer, ns_to_ktime(delay), 0, |
5c333864 | 1127 | HRTIMER_MODE_REL_PINNED, 0); |
31656519 | 1128 | } |
b328ca18 | 1129 | |
006c75f1 | 1130 | static inline void init_hrtick(void) |
8f4d37ec | 1131 | { |
8f4d37ec | 1132 | } |
31656519 | 1133 | #endif /* CONFIG_SMP */ |
8f4d37ec | 1134 | |
31656519 | 1135 | static void init_rq_hrtick(struct rq *rq) |
8f4d37ec | 1136 | { |
31656519 PZ |
1137 | #ifdef CONFIG_SMP |
1138 | rq->hrtick_csd_pending = 0; | |
8f4d37ec | 1139 | |
31656519 PZ |
1140 | rq->hrtick_csd.flags = 0; |
1141 | rq->hrtick_csd.func = __hrtick_start; | |
1142 | rq->hrtick_csd.info = rq; | |
1143 | #endif | |
8f4d37ec | 1144 | |
31656519 PZ |
1145 | hrtimer_init(&rq->hrtick_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); |
1146 | rq->hrtick_timer.function = hrtick; | |
8f4d37ec | 1147 | } |
006c75f1 | 1148 | #else /* CONFIG_SCHED_HRTICK */ |
8f4d37ec PZ |
1149 | static inline void hrtick_clear(struct rq *rq) |
1150 | { | |
1151 | } | |
1152 | ||
8f4d37ec PZ |
1153 | static inline void init_rq_hrtick(struct rq *rq) |
1154 | { | |
1155 | } | |
1156 | ||
b328ca18 PZ |
1157 | static inline void init_hrtick(void) |
1158 | { | |
1159 | } | |
006c75f1 | 1160 | #endif /* CONFIG_SCHED_HRTICK */ |
8f4d37ec | 1161 | |
c24d20db IM |
1162 | /* |
1163 | * resched_task - mark a task 'to be rescheduled now'. | |
1164 | * | |
1165 | * On UP this means the setting of the need_resched flag, on SMP it | |
1166 | * might also involve a cross-CPU call to trigger the scheduler on | |
1167 | * the target CPU. | |
1168 | */ | |
1169 | #ifdef CONFIG_SMP | |
1170 | ||
1171 | #ifndef tsk_is_polling | |
1172 | #define tsk_is_polling(t) test_tsk_thread_flag(t, TIF_POLLING_NRFLAG) | |
1173 | #endif | |
1174 | ||
31656519 | 1175 | static void resched_task(struct task_struct *p) |
c24d20db IM |
1176 | { |
1177 | int cpu; | |
1178 | ||
05fa785c | 1179 | assert_raw_spin_locked(&task_rq(p)->lock); |
c24d20db | 1180 | |
5ed0cec0 | 1181 | if (test_tsk_need_resched(p)) |
c24d20db IM |
1182 | return; |
1183 | ||
5ed0cec0 | 1184 | set_tsk_need_resched(p); |
c24d20db IM |
1185 | |
1186 | cpu = task_cpu(p); | |
1187 | if (cpu == smp_processor_id()) | |
1188 | return; | |
1189 | ||
1190 | /* NEED_RESCHED must be visible before we test polling */ | |
1191 | smp_mb(); | |
1192 | if (!tsk_is_polling(p)) | |
1193 | smp_send_reschedule(cpu); | |
1194 | } | |
1195 | ||
1196 | static void resched_cpu(int cpu) | |
1197 | { | |
1198 | struct rq *rq = cpu_rq(cpu); | |
1199 | unsigned long flags; | |
1200 | ||
05fa785c | 1201 | if (!raw_spin_trylock_irqsave(&rq->lock, flags)) |
c24d20db IM |
1202 | return; |
1203 | resched_task(cpu_curr(cpu)); | |
05fa785c | 1204 | raw_spin_unlock_irqrestore(&rq->lock, flags); |
c24d20db | 1205 | } |
06d8308c TG |
1206 | |
1207 | #ifdef CONFIG_NO_HZ | |
83cd4fe2 VP |
1208 | /* |
1209 | * In the semi idle case, use the nearest busy cpu for migrating timers | |
1210 | * from an idle cpu. This is good for power-savings. | |
1211 | * | |
1212 | * We don't do similar optimization for completely idle system, as | |
1213 | * selecting an idle cpu will add more delays to the timers than intended | |
1214 | * (as that cpu's timer base may not be uptodate wrt jiffies etc). | |
1215 | */ | |
1216 | int get_nohz_timer_target(void) | |
1217 | { | |
1218 | int cpu = smp_processor_id(); | |
1219 | int i; | |
1220 | struct sched_domain *sd; | |
1221 | ||
057f3fad | 1222 | rcu_read_lock(); |
83cd4fe2 | 1223 | for_each_domain(cpu, sd) { |
057f3fad PZ |
1224 | for_each_cpu(i, sched_domain_span(sd)) { |
1225 | if (!idle_cpu(i)) { | |
1226 | cpu = i; | |
1227 | goto unlock; | |
1228 | } | |
1229 | } | |
83cd4fe2 | 1230 | } |
057f3fad PZ |
1231 | unlock: |
1232 | rcu_read_unlock(); | |
83cd4fe2 VP |
1233 | return cpu; |
1234 | } | |
06d8308c TG |
1235 | /* |
1236 | * When add_timer_on() enqueues a timer into the timer wheel of an | |
1237 | * idle CPU then this timer might expire before the next timer event | |
1238 | * which is scheduled to wake up that CPU. In case of a completely | |
1239 | * idle system the next event might even be infinite time into the | |
1240 | * future. wake_up_idle_cpu() ensures that the CPU is woken up and | |
1241 | * leaves the inner idle loop so the newly added timer is taken into | |
1242 | * account when the CPU goes back to idle and evaluates the timer | |
1243 | * wheel for the next timer event. | |
1244 | */ | |
1245 | void wake_up_idle_cpu(int cpu) | |
1246 | { | |
1247 | struct rq *rq = cpu_rq(cpu); | |
1248 | ||
1249 | if (cpu == smp_processor_id()) | |
1250 | return; | |
1251 | ||
1252 | /* | |
1253 | * This is safe, as this function is called with the timer | |
1254 | * wheel base lock of (cpu) held. When the CPU is on the way | |
1255 | * to idle and has not yet set rq->curr to idle then it will | |
1256 | * be serialized on the timer wheel base lock and take the new | |
1257 | * timer into account automatically. | |
1258 | */ | |
1259 | if (rq->curr != rq->idle) | |
1260 | return; | |
1261 | ||
1262 | /* | |
1263 | * We can set TIF_RESCHED on the idle task of the other CPU | |
1264 | * lockless. The worst case is that the other CPU runs the | |
1265 | * idle task through an additional NOOP schedule() | |
1266 | */ | |
5ed0cec0 | 1267 | set_tsk_need_resched(rq->idle); |
06d8308c TG |
1268 | |
1269 | /* NEED_RESCHED must be visible before we test polling */ | |
1270 | smp_mb(); | |
1271 | if (!tsk_is_polling(rq->idle)) | |
1272 | smp_send_reschedule(cpu); | |
1273 | } | |
39c0cbe2 | 1274 | |
6d6bc0ad | 1275 | #endif /* CONFIG_NO_HZ */ |
06d8308c | 1276 | |
e9e9250b PZ |
1277 | static u64 sched_avg_period(void) |
1278 | { | |
1279 | return (u64)sysctl_sched_time_avg * NSEC_PER_MSEC / 2; | |
1280 | } | |
1281 | ||
1282 | static void sched_avg_update(struct rq *rq) | |
1283 | { | |
1284 | s64 period = sched_avg_period(); | |
1285 | ||
1286 | while ((s64)(rq->clock - rq->age_stamp) > period) { | |
0d98bb26 WD |
1287 | /* |
1288 | * Inline assembly required to prevent the compiler | |
1289 | * optimising this loop into a divmod call. | |
1290 | * See __iter_div_u64_rem() for another example of this. | |
1291 | */ | |
1292 | asm("" : "+rm" (rq->age_stamp)); | |
e9e9250b PZ |
1293 | rq->age_stamp += period; |
1294 | rq->rt_avg /= 2; | |
1295 | } | |
1296 | } | |
1297 | ||
1298 | static void sched_rt_avg_update(struct rq *rq, u64 rt_delta) | |
1299 | { | |
1300 | rq->rt_avg += rt_delta; | |
1301 | sched_avg_update(rq); | |
1302 | } | |
1303 | ||
6d6bc0ad | 1304 | #else /* !CONFIG_SMP */ |
31656519 | 1305 | static void resched_task(struct task_struct *p) |
c24d20db | 1306 | { |
05fa785c | 1307 | assert_raw_spin_locked(&task_rq(p)->lock); |
31656519 | 1308 | set_tsk_need_resched(p); |
c24d20db | 1309 | } |
e9e9250b PZ |
1310 | |
1311 | static void sched_rt_avg_update(struct rq *rq, u64 rt_delta) | |
1312 | { | |
1313 | } | |
da2b71ed SS |
1314 | |
1315 | static void sched_avg_update(struct rq *rq) | |
1316 | { | |
1317 | } | |
6d6bc0ad | 1318 | #endif /* CONFIG_SMP */ |
c24d20db | 1319 | |
45bf76df IM |
1320 | #if BITS_PER_LONG == 32 |
1321 | # define WMULT_CONST (~0UL) | |
1322 | #else | |
1323 | # define WMULT_CONST (1UL << 32) | |
1324 | #endif | |
1325 | ||
1326 | #define WMULT_SHIFT 32 | |
1327 | ||
194081eb IM |
1328 | /* |
1329 | * Shift right and round: | |
1330 | */ | |
cf2ab469 | 1331 | #define SRR(x, y) (((x) + (1UL << ((y) - 1))) >> (y)) |
194081eb | 1332 | |
a7be37ac PZ |
1333 | /* |
1334 | * delta *= weight / lw | |
1335 | */ | |
cb1c4fc9 | 1336 | static unsigned long |
45bf76df IM |
1337 | calc_delta_mine(unsigned long delta_exec, unsigned long weight, |
1338 | struct load_weight *lw) | |
1339 | { | |
1340 | u64 tmp; | |
1341 | ||
c8b28116 NR |
1342 | /* |
1343 | * weight can be less than 2^SCHED_LOAD_RESOLUTION for task group sched | |
1344 | * entities since MIN_SHARES = 2. Treat weight as 1 if less than | |
1345 | * 2^SCHED_LOAD_RESOLUTION. | |
1346 | */ | |
1347 | if (likely(weight > (1UL << SCHED_LOAD_RESOLUTION))) | |
1348 | tmp = (u64)delta_exec * scale_load_down(weight); | |
1349 | else | |
1350 | tmp = (u64)delta_exec; | |
db670dac | 1351 | |
7a232e03 | 1352 | if (!lw->inv_weight) { |
c8b28116 NR |
1353 | unsigned long w = scale_load_down(lw->weight); |
1354 | ||
1355 | if (BITS_PER_LONG > 32 && unlikely(w >= WMULT_CONST)) | |
7a232e03 | 1356 | lw->inv_weight = 1; |
c8b28116 NR |
1357 | else if (unlikely(!w)) |
1358 | lw->inv_weight = WMULT_CONST; | |
7a232e03 | 1359 | else |
c8b28116 | 1360 | lw->inv_weight = WMULT_CONST / w; |
7a232e03 | 1361 | } |
45bf76df | 1362 | |
45bf76df IM |
1363 | /* |
1364 | * Check whether we'd overflow the 64-bit multiplication: | |
1365 | */ | |
194081eb | 1366 | if (unlikely(tmp > WMULT_CONST)) |
cf2ab469 | 1367 | tmp = SRR(SRR(tmp, WMULT_SHIFT/2) * lw->inv_weight, |
194081eb IM |
1368 | WMULT_SHIFT/2); |
1369 | else | |
cf2ab469 | 1370 | tmp = SRR(tmp * lw->inv_weight, WMULT_SHIFT); |
45bf76df | 1371 | |
ecf691da | 1372 | return (unsigned long)min(tmp, (u64)(unsigned long)LONG_MAX); |
45bf76df IM |
1373 | } |
1374 | ||
1091985b | 1375 | static inline void update_load_add(struct load_weight *lw, unsigned long inc) |
45bf76df IM |
1376 | { |
1377 | lw->weight += inc; | |
e89996ae | 1378 | lw->inv_weight = 0; |
45bf76df IM |
1379 | } |
1380 | ||
1091985b | 1381 | static inline void update_load_sub(struct load_weight *lw, unsigned long dec) |
45bf76df IM |
1382 | { |
1383 | lw->weight -= dec; | |
e89996ae | 1384 | lw->inv_weight = 0; |
45bf76df IM |
1385 | } |
1386 | ||
2069dd75 PZ |
1387 | static inline void update_load_set(struct load_weight *lw, unsigned long w) |
1388 | { | |
1389 | lw->weight = w; | |
1390 | lw->inv_weight = 0; | |
1391 | } | |
1392 | ||
2dd73a4f PW |
1393 | /* |
1394 | * To aid in avoiding the subversion of "niceness" due to uneven distribution | |
1395 | * of tasks with abnormal "nice" values across CPUs the contribution that | |
1396 | * each task makes to its run queue's load is weighted according to its | |
41a2d6cf | 1397 | * scheduling class and "nice" value. For SCHED_NORMAL tasks this is just a |
2dd73a4f PW |
1398 | * scaled version of the new time slice allocation that they receive on time |
1399 | * slice expiry etc. | |
1400 | */ | |
1401 | ||
cce7ade8 PZ |
1402 | #define WEIGHT_IDLEPRIO 3 |
1403 | #define WMULT_IDLEPRIO 1431655765 | |
dd41f596 IM |
1404 | |
1405 | /* | |
1406 | * Nice levels are multiplicative, with a gentle 10% change for every | |
1407 | * nice level changed. I.e. when a CPU-bound task goes from nice 0 to | |
1408 | * nice 1, it will get ~10% less CPU time than another CPU-bound task | |
1409 | * that remained on nice 0. | |
1410 | * | |
1411 | * The "10% effect" is relative and cumulative: from _any_ nice level, | |
1412 | * if you go up 1 level, it's -10% CPU usage, if you go down 1 level | |
f9153ee6 IM |
1413 | * it's +10% CPU usage. (to achieve that we use a multiplier of 1.25. |
1414 | * If a task goes up by ~10% and another task goes down by ~10% then | |
1415 | * the relative distance between them is ~25%.) | |
dd41f596 IM |
1416 | */ |
1417 | static const int prio_to_weight[40] = { | |
254753dc IM |
1418 | /* -20 */ 88761, 71755, 56483, 46273, 36291, |
1419 | /* -15 */ 29154, 23254, 18705, 14949, 11916, | |
1420 | /* -10 */ 9548, 7620, 6100, 4904, 3906, | |
1421 | /* -5 */ 3121, 2501, 1991, 1586, 1277, | |
1422 | /* 0 */ 1024, 820, 655, 526, 423, | |
1423 | /* 5 */ 335, 272, 215, 172, 137, | |
1424 | /* 10 */ 110, 87, 70, 56, 45, | |
1425 | /* 15 */ 36, 29, 23, 18, 15, | |
dd41f596 IM |
1426 | }; |
1427 | ||
5714d2de IM |
1428 | /* |
1429 | * Inverse (2^32/x) values of the prio_to_weight[] array, precalculated. | |
1430 | * | |
1431 | * In cases where the weight does not change often, we can use the | |
1432 | * precalculated inverse to speed up arithmetics by turning divisions | |
1433 | * into multiplications: | |
1434 | */ | |
dd41f596 | 1435 | static const u32 prio_to_wmult[40] = { |
254753dc IM |
1436 | /* -20 */ 48388, 59856, 76040, 92818, 118348, |
1437 | /* -15 */ 147320, 184698, 229616, 287308, 360437, | |
1438 | /* -10 */ 449829, 563644, 704093, 875809, 1099582, | |
1439 | /* -5 */ 1376151, 1717300, 2157191, 2708050, 3363326, | |
1440 | /* 0 */ 4194304, 5237765, 6557202, 8165337, 10153587, | |
1441 | /* 5 */ 12820798, 15790321, 19976592, 24970740, 31350126, | |
1442 | /* 10 */ 39045157, 49367440, 61356676, 76695844, 95443717, | |
1443 | /* 15 */ 119304647, 148102320, 186737708, 238609294, 286331153, | |
dd41f596 | 1444 | }; |
2dd73a4f | 1445 | |
ef12fefa BR |
1446 | /* Time spent by the tasks of the cpu accounting group executing in ... */ |
1447 | enum cpuacct_stat_index { | |
1448 | CPUACCT_STAT_USER, /* ... user mode */ | |
1449 | CPUACCT_STAT_SYSTEM, /* ... kernel mode */ | |
1450 | ||
1451 | CPUACCT_STAT_NSTATS, | |
1452 | }; | |
1453 | ||
d842de87 SV |
1454 | #ifdef CONFIG_CGROUP_CPUACCT |
1455 | static void cpuacct_charge(struct task_struct *tsk, u64 cputime); | |
ef12fefa BR |
1456 | static void cpuacct_update_stats(struct task_struct *tsk, |
1457 | enum cpuacct_stat_index idx, cputime_t val); | |
d842de87 SV |
1458 | #else |
1459 | static inline void cpuacct_charge(struct task_struct *tsk, u64 cputime) {} | |
ef12fefa BR |
1460 | static inline void cpuacct_update_stats(struct task_struct *tsk, |
1461 | enum cpuacct_stat_index idx, cputime_t val) {} | |
d842de87 SV |
1462 | #endif |
1463 | ||
18d95a28 PZ |
1464 | static inline void inc_cpu_load(struct rq *rq, unsigned long load) |
1465 | { | |
1466 | update_load_add(&rq->load, load); | |
1467 | } | |
1468 | ||
1469 | static inline void dec_cpu_load(struct rq *rq, unsigned long load) | |
1470 | { | |
1471 | update_load_sub(&rq->load, load); | |
1472 | } | |
1473 | ||
7940ca36 | 1474 | #if (defined(CONFIG_SMP) && defined(CONFIG_FAIR_GROUP_SCHED)) || defined(CONFIG_RT_GROUP_SCHED) |
eb755805 | 1475 | typedef int (*tg_visitor)(struct task_group *, void *); |
c09595f6 PZ |
1476 | |
1477 | /* | |
1478 | * Iterate the full tree, calling @down when first entering a node and @up when | |
1479 | * leaving it for the final time. | |
1480 | */ | |
eb755805 | 1481 | static int walk_tg_tree(tg_visitor down, tg_visitor up, void *data) |
c09595f6 PZ |
1482 | { |
1483 | struct task_group *parent, *child; | |
eb755805 | 1484 | int ret; |
c09595f6 PZ |
1485 | |
1486 | rcu_read_lock(); | |
1487 | parent = &root_task_group; | |
1488 | down: | |
eb755805 PZ |
1489 | ret = (*down)(parent, data); |
1490 | if (ret) | |
1491 | goto out_unlock; | |
c09595f6 PZ |
1492 | list_for_each_entry_rcu(child, &parent->children, siblings) { |
1493 | parent = child; | |
1494 | goto down; | |
1495 | ||
1496 | up: | |
1497 | continue; | |
1498 | } | |
eb755805 PZ |
1499 | ret = (*up)(parent, data); |
1500 | if (ret) | |
1501 | goto out_unlock; | |
c09595f6 PZ |
1502 | |
1503 | child = parent; | |
1504 | parent = parent->parent; | |
1505 | if (parent) | |
1506 | goto up; | |
eb755805 | 1507 | out_unlock: |
c09595f6 | 1508 | rcu_read_unlock(); |
eb755805 PZ |
1509 | |
1510 | return ret; | |
c09595f6 PZ |
1511 | } |
1512 | ||
eb755805 PZ |
1513 | static int tg_nop(struct task_group *tg, void *data) |
1514 | { | |
1515 | return 0; | |
c09595f6 | 1516 | } |
eb755805 PZ |
1517 | #endif |
1518 | ||
1519 | #ifdef CONFIG_SMP | |
f5f08f39 PZ |
1520 | /* Used instead of source_load when we know the type == 0 */ |
1521 | static unsigned long weighted_cpuload(const int cpu) | |
1522 | { | |
1523 | return cpu_rq(cpu)->load.weight; | |
1524 | } | |
1525 | ||
1526 | /* | |
1527 | * Return a low guess at the load of a migration-source cpu weighted | |
1528 | * according to the scheduling class and "nice" value. | |
1529 | * | |
1530 | * We want to under-estimate the load of migration sources, to | |
1531 | * balance conservatively. | |
1532 | */ | |
1533 | static unsigned long source_load(int cpu, int type) | |
1534 | { | |
1535 | struct rq *rq = cpu_rq(cpu); | |
1536 | unsigned long total = weighted_cpuload(cpu); | |
1537 | ||
1538 | if (type == 0 || !sched_feat(LB_BIAS)) | |
1539 | return total; | |
1540 | ||
1541 | return min(rq->cpu_load[type-1], total); | |
1542 | } | |
1543 | ||
1544 | /* | |
1545 | * Return a high guess at the load of a migration-target cpu weighted | |
1546 | * according to the scheduling class and "nice" value. | |
1547 | */ | |
1548 | static unsigned long target_load(int cpu, int type) | |
1549 | { | |
1550 | struct rq *rq = cpu_rq(cpu); | |
1551 | unsigned long total = weighted_cpuload(cpu); | |
1552 | ||
1553 | if (type == 0 || !sched_feat(LB_BIAS)) | |
1554 | return total; | |
1555 | ||
1556 | return max(rq->cpu_load[type-1], total); | |
1557 | } | |
1558 | ||
ae154be1 PZ |
1559 | static unsigned long power_of(int cpu) |
1560 | { | |
e51fd5e2 | 1561 | return cpu_rq(cpu)->cpu_power; |
ae154be1 PZ |
1562 | } |
1563 | ||
eb755805 PZ |
1564 | static int task_hot(struct task_struct *p, u64 now, struct sched_domain *sd); |
1565 | ||
1566 | static unsigned long cpu_avg_load_per_task(int cpu) | |
1567 | { | |
1568 | struct rq *rq = cpu_rq(cpu); | |
af6d596f | 1569 | unsigned long nr_running = ACCESS_ONCE(rq->nr_running); |
eb755805 | 1570 | |
4cd42620 SR |
1571 | if (nr_running) |
1572 | rq->avg_load_per_task = rq->load.weight / nr_running; | |
a2d47777 BS |
1573 | else |
1574 | rq->avg_load_per_task = 0; | |
eb755805 PZ |
1575 | |
1576 | return rq->avg_load_per_task; | |
1577 | } | |
1578 | ||
8f45e2b5 GH |
1579 | #ifdef CONFIG_PREEMPT |
1580 | ||
b78bb868 PZ |
1581 | static void double_rq_lock(struct rq *rq1, struct rq *rq2); |
1582 | ||
70574a99 | 1583 | /* |
8f45e2b5 GH |
1584 | * fair double_lock_balance: Safely acquires both rq->locks in a fair |
1585 | * way at the expense of forcing extra atomic operations in all | |
1586 | * invocations. This assures that the double_lock is acquired using the | |
1587 | * same underlying policy as the spinlock_t on this architecture, which | |
1588 | * reduces latency compared to the unfair variant below. However, it | |
1589 | * also adds more overhead and therefore may reduce throughput. | |
70574a99 | 1590 | */ |
8f45e2b5 GH |
1591 | static inline int _double_lock_balance(struct rq *this_rq, struct rq *busiest) |
1592 | __releases(this_rq->lock) | |
1593 | __acquires(busiest->lock) | |
1594 | __acquires(this_rq->lock) | |
1595 | { | |
05fa785c | 1596 | raw_spin_unlock(&this_rq->lock); |
8f45e2b5 GH |
1597 | double_rq_lock(this_rq, busiest); |
1598 | ||
1599 | return 1; | |
1600 | } | |
1601 | ||
1602 | #else | |
1603 | /* | |
1604 | * Unfair double_lock_balance: Optimizes throughput at the expense of | |
1605 | * latency by eliminating extra atomic operations when the locks are | |
1606 | * already in proper order on entry. This favors lower cpu-ids and will | |
1607 | * grant the double lock to lower cpus over higher ids under contention, | |
1608 | * regardless of entry order into the function. | |
1609 | */ | |
1610 | static int _double_lock_balance(struct rq *this_rq, struct rq *busiest) | |
70574a99 AD |
1611 | __releases(this_rq->lock) |
1612 | __acquires(busiest->lock) | |
1613 | __acquires(this_rq->lock) | |
1614 | { | |
1615 | int ret = 0; | |
1616 | ||
05fa785c | 1617 | if (unlikely(!raw_spin_trylock(&busiest->lock))) { |
70574a99 | 1618 | if (busiest < this_rq) { |
05fa785c TG |
1619 | raw_spin_unlock(&this_rq->lock); |
1620 | raw_spin_lock(&busiest->lock); | |
1621 | raw_spin_lock_nested(&this_rq->lock, | |
1622 | SINGLE_DEPTH_NESTING); | |
70574a99 AD |
1623 | ret = 1; |
1624 | } else | |
05fa785c TG |
1625 | raw_spin_lock_nested(&busiest->lock, |
1626 | SINGLE_DEPTH_NESTING); | |
70574a99 AD |
1627 | } |
1628 | return ret; | |
1629 | } | |
1630 | ||
8f45e2b5 GH |
1631 | #endif /* CONFIG_PREEMPT */ |
1632 | ||
1633 | /* | |
1634 | * double_lock_balance - lock the busiest runqueue, this_rq is locked already. | |
1635 | */ | |
1636 | static int double_lock_balance(struct rq *this_rq, struct rq *busiest) | |
1637 | { | |
1638 | if (unlikely(!irqs_disabled())) { | |
1639 | /* printk() doesn't work good under rq->lock */ | |
05fa785c | 1640 | raw_spin_unlock(&this_rq->lock); |
8f45e2b5 GH |
1641 | BUG_ON(1); |
1642 | } | |
1643 | ||
1644 | return _double_lock_balance(this_rq, busiest); | |
1645 | } | |
1646 | ||
70574a99 AD |
1647 | static inline void double_unlock_balance(struct rq *this_rq, struct rq *busiest) |
1648 | __releases(busiest->lock) | |
1649 | { | |
05fa785c | 1650 | raw_spin_unlock(&busiest->lock); |
70574a99 AD |
1651 | lock_set_subclass(&this_rq->lock.dep_map, 0, _RET_IP_); |
1652 | } | |
1e3c88bd PZ |
1653 | |
1654 | /* | |
1655 | * double_rq_lock - safely lock two runqueues | |
1656 | * | |
1657 | * Note this does not disable interrupts like task_rq_lock, | |
1658 | * you need to do so manually before calling. | |
1659 | */ | |
1660 | static void double_rq_lock(struct rq *rq1, struct rq *rq2) | |
1661 | __acquires(rq1->lock) | |
1662 | __acquires(rq2->lock) | |
1663 | { | |
1664 | BUG_ON(!irqs_disabled()); | |
1665 | if (rq1 == rq2) { | |
1666 | raw_spin_lock(&rq1->lock); | |
1667 | __acquire(rq2->lock); /* Fake it out ;) */ | |
1668 | } else { | |
1669 | if (rq1 < rq2) { | |
1670 | raw_spin_lock(&rq1->lock); | |
1671 | raw_spin_lock_nested(&rq2->lock, SINGLE_DEPTH_NESTING); | |
1672 | } else { | |
1673 | raw_spin_lock(&rq2->lock); | |
1674 | raw_spin_lock_nested(&rq1->lock, SINGLE_DEPTH_NESTING); | |
1675 | } | |
1676 | } | |
1e3c88bd PZ |
1677 | } |
1678 | ||
1679 | /* | |
1680 | * double_rq_unlock - safely unlock two runqueues | |
1681 | * | |
1682 | * Note this does not restore interrupts like task_rq_unlock, | |
1683 | * you need to do so manually after calling. | |
1684 | */ | |
1685 | static void double_rq_unlock(struct rq *rq1, struct rq *rq2) | |
1686 | __releases(rq1->lock) | |
1687 | __releases(rq2->lock) | |
1688 | { | |
1689 | raw_spin_unlock(&rq1->lock); | |
1690 | if (rq1 != rq2) | |
1691 | raw_spin_unlock(&rq2->lock); | |
1692 | else | |
1693 | __release(rq2->lock); | |
1694 | } | |
1695 | ||
d95f4122 MG |
1696 | #else /* CONFIG_SMP */ |
1697 | ||
1698 | /* | |
1699 | * double_rq_lock - safely lock two runqueues | |
1700 | * | |
1701 | * Note this does not disable interrupts like task_rq_lock, | |
1702 | * you need to do so manually before calling. | |
1703 | */ | |
1704 | static void double_rq_lock(struct rq *rq1, struct rq *rq2) | |
1705 | __acquires(rq1->lock) | |
1706 | __acquires(rq2->lock) | |
1707 | { | |
1708 | BUG_ON(!irqs_disabled()); | |
1709 | BUG_ON(rq1 != rq2); | |
1710 | raw_spin_lock(&rq1->lock); | |
1711 | __acquire(rq2->lock); /* Fake it out ;) */ | |
1712 | } | |
1713 | ||
1714 | /* | |
1715 | * double_rq_unlock - safely unlock two runqueues | |
1716 | * | |
1717 | * Note this does not restore interrupts like task_rq_unlock, | |
1718 | * you need to do so manually after calling. | |
1719 | */ | |
1720 | static void double_rq_unlock(struct rq *rq1, struct rq *rq2) | |
1721 | __releases(rq1->lock) | |
1722 | __releases(rq2->lock) | |
1723 | { | |
1724 | BUG_ON(rq1 != rq2); | |
1725 | raw_spin_unlock(&rq1->lock); | |
1726 | __release(rq2->lock); | |
1727 | } | |
1728 | ||
18d95a28 PZ |
1729 | #endif |
1730 | ||
74f5187a | 1731 | static void calc_load_account_idle(struct rq *this_rq); |
0bcdcf28 | 1732 | static void update_sysctl(void); |
acb4a848 | 1733 | static int get_update_sysctl_factor(void); |
fdf3e95d | 1734 | static void update_cpu_load(struct rq *this_rq); |
dce48a84 | 1735 | |
cd29fe6f PZ |
1736 | static inline void __set_task_cpu(struct task_struct *p, unsigned int cpu) |
1737 | { | |
1738 | set_task_rq(p, cpu); | |
1739 | #ifdef CONFIG_SMP | |
1740 | /* | |
1741 | * After ->cpu is set up to a new value, task_rq_lock(p, ...) can be | |
1742 | * successfuly executed on another CPU. We must ensure that updates of | |
1743 | * per-task data have been completed by this moment. | |
1744 | */ | |
1745 | smp_wmb(); | |
1746 | task_thread_info(p)->cpu = cpu; | |
1747 | #endif | |
1748 | } | |
dce48a84 | 1749 | |
1e3c88bd | 1750 | static const struct sched_class rt_sched_class; |
dd41f596 | 1751 | |
34f971f6 | 1752 | #define sched_class_highest (&stop_sched_class) |
1f11eb6a GH |
1753 | #define for_each_class(class) \ |
1754 | for (class = sched_class_highest; class; class = class->next) | |
dd41f596 | 1755 | |
1e3c88bd PZ |
1756 | #include "sched_stats.h" |
1757 | ||
c09595f6 | 1758 | static void inc_nr_running(struct rq *rq) |
9c217245 IM |
1759 | { |
1760 | rq->nr_running++; | |
9c217245 IM |
1761 | } |
1762 | ||
c09595f6 | 1763 | static void dec_nr_running(struct rq *rq) |
9c217245 IM |
1764 | { |
1765 | rq->nr_running--; | |
9c217245 IM |
1766 | } |
1767 | ||
45bf76df IM |
1768 | static void set_load_weight(struct task_struct *p) |
1769 | { | |
f05998d4 NR |
1770 | int prio = p->static_prio - MAX_RT_PRIO; |
1771 | struct load_weight *load = &p->se.load; | |
1772 | ||
dd41f596 IM |
1773 | /* |
1774 | * SCHED_IDLE tasks get minimal weight: | |
1775 | */ | |
1776 | if (p->policy == SCHED_IDLE) { | |
c8b28116 | 1777 | load->weight = scale_load(WEIGHT_IDLEPRIO); |
f05998d4 | 1778 | load->inv_weight = WMULT_IDLEPRIO; |
dd41f596 IM |
1779 | return; |
1780 | } | |
71f8bd46 | 1781 | |
c8b28116 | 1782 | load->weight = scale_load(prio_to_weight[prio]); |
f05998d4 | 1783 | load->inv_weight = prio_to_wmult[prio]; |
71f8bd46 IM |
1784 | } |
1785 | ||
371fd7e7 | 1786 | static void enqueue_task(struct rq *rq, struct task_struct *p, int flags) |
2087a1ad | 1787 | { |
a64692a3 | 1788 | update_rq_clock(rq); |
dd41f596 | 1789 | sched_info_queued(p); |
371fd7e7 | 1790 | p->sched_class->enqueue_task(rq, p, flags); |
71f8bd46 IM |
1791 | } |
1792 | ||
371fd7e7 | 1793 | static void dequeue_task(struct rq *rq, struct task_struct *p, int flags) |
71f8bd46 | 1794 | { |
a64692a3 | 1795 | update_rq_clock(rq); |
46ac22ba | 1796 | sched_info_dequeued(p); |
371fd7e7 | 1797 | p->sched_class->dequeue_task(rq, p, flags); |
71f8bd46 IM |
1798 | } |
1799 | ||
1e3c88bd PZ |
1800 | /* |
1801 | * activate_task - move a task to the runqueue. | |
1802 | */ | |
371fd7e7 | 1803 | static void activate_task(struct rq *rq, struct task_struct *p, int flags) |
1e3c88bd PZ |
1804 | { |
1805 | if (task_contributes_to_load(p)) | |
1806 | rq->nr_uninterruptible--; | |
1807 | ||
371fd7e7 | 1808 | enqueue_task(rq, p, flags); |
1e3c88bd PZ |
1809 | inc_nr_running(rq); |
1810 | } | |
1811 | ||
1812 | /* | |
1813 | * deactivate_task - remove a task from the runqueue. | |
1814 | */ | |
371fd7e7 | 1815 | static void deactivate_task(struct rq *rq, struct task_struct *p, int flags) |
1e3c88bd PZ |
1816 | { |
1817 | if (task_contributes_to_load(p)) | |
1818 | rq->nr_uninterruptible++; | |
1819 | ||
371fd7e7 | 1820 | dequeue_task(rq, p, flags); |
1e3c88bd PZ |
1821 | dec_nr_running(rq); |
1822 | } | |
1823 | ||
b52bfee4 VP |
1824 | #ifdef CONFIG_IRQ_TIME_ACCOUNTING |
1825 | ||
305e6835 VP |
1826 | /* |
1827 | * There are no locks covering percpu hardirq/softirq time. | |
1828 | * They are only modified in account_system_vtime, on corresponding CPU | |
1829 | * with interrupts disabled. So, writes are safe. | |
1830 | * They are read and saved off onto struct rq in update_rq_clock(). | |
1831 | * This may result in other CPU reading this CPU's irq time and can | |
1832 | * race with irq/account_system_vtime on this CPU. We would either get old | |
8e92c201 PZ |
1833 | * or new value with a side effect of accounting a slice of irq time to wrong |
1834 | * task when irq is in progress while we read rq->clock. That is a worthy | |
1835 | * compromise in place of having locks on each irq in account_system_time. | |
305e6835 | 1836 | */ |
b52bfee4 VP |
1837 | static DEFINE_PER_CPU(u64, cpu_hardirq_time); |
1838 | static DEFINE_PER_CPU(u64, cpu_softirq_time); | |
1839 | ||
1840 | static DEFINE_PER_CPU(u64, irq_start_time); | |
1841 | static int sched_clock_irqtime; | |
1842 | ||
1843 | void enable_sched_clock_irqtime(void) | |
1844 | { | |
1845 | sched_clock_irqtime = 1; | |
1846 | } | |
1847 | ||
1848 | void disable_sched_clock_irqtime(void) | |
1849 | { | |
1850 | sched_clock_irqtime = 0; | |
1851 | } | |
1852 | ||
8e92c201 PZ |
1853 | #ifndef CONFIG_64BIT |
1854 | static DEFINE_PER_CPU(seqcount_t, irq_time_seq); | |
1855 | ||
1856 | static inline void irq_time_write_begin(void) | |
1857 | { | |
1858 | __this_cpu_inc(irq_time_seq.sequence); | |
1859 | smp_wmb(); | |
1860 | } | |
1861 | ||
1862 | static inline void irq_time_write_end(void) | |
1863 | { | |
1864 | smp_wmb(); | |
1865 | __this_cpu_inc(irq_time_seq.sequence); | |
1866 | } | |
1867 | ||
1868 | static inline u64 irq_time_read(int cpu) | |
1869 | { | |
1870 | u64 irq_time; | |
1871 | unsigned seq; | |
1872 | ||
1873 | do { | |
1874 | seq = read_seqcount_begin(&per_cpu(irq_time_seq, cpu)); | |
1875 | irq_time = per_cpu(cpu_softirq_time, cpu) + | |
1876 | per_cpu(cpu_hardirq_time, cpu); | |
1877 | } while (read_seqcount_retry(&per_cpu(irq_time_seq, cpu), seq)); | |
1878 | ||
1879 | return irq_time; | |
1880 | } | |
1881 | #else /* CONFIG_64BIT */ | |
1882 | static inline void irq_time_write_begin(void) | |
1883 | { | |
1884 | } | |
1885 | ||
1886 | static inline void irq_time_write_end(void) | |
1887 | { | |
1888 | } | |
1889 | ||
1890 | static inline u64 irq_time_read(int cpu) | |
305e6835 | 1891 | { |
305e6835 VP |
1892 | return per_cpu(cpu_softirq_time, cpu) + per_cpu(cpu_hardirq_time, cpu); |
1893 | } | |
8e92c201 | 1894 | #endif /* CONFIG_64BIT */ |
305e6835 | 1895 | |
fe44d621 PZ |
1896 | /* |
1897 | * Called before incrementing preempt_count on {soft,}irq_enter | |
1898 | * and before decrementing preempt_count on {soft,}irq_exit. | |
1899 | */ | |
b52bfee4 VP |
1900 | void account_system_vtime(struct task_struct *curr) |
1901 | { | |
1902 | unsigned long flags; | |
fe44d621 | 1903 | s64 delta; |
b52bfee4 | 1904 | int cpu; |
b52bfee4 VP |
1905 | |
1906 | if (!sched_clock_irqtime) | |
1907 | return; | |
1908 | ||
1909 | local_irq_save(flags); | |
1910 | ||
b52bfee4 | 1911 | cpu = smp_processor_id(); |
fe44d621 PZ |
1912 | delta = sched_clock_cpu(cpu) - __this_cpu_read(irq_start_time); |
1913 | __this_cpu_add(irq_start_time, delta); | |
1914 | ||
8e92c201 | 1915 | irq_time_write_begin(); |
b52bfee4 VP |
1916 | /* |
1917 | * We do not account for softirq time from ksoftirqd here. | |
1918 | * We want to continue accounting softirq time to ksoftirqd thread | |
1919 | * in that case, so as not to confuse scheduler with a special task | |
1920 | * that do not consume any time, but still wants to run. | |
1921 | */ | |
1922 | if (hardirq_count()) | |
fe44d621 | 1923 | __this_cpu_add(cpu_hardirq_time, delta); |
4dd53d89 | 1924 | else if (in_serving_softirq() && curr != this_cpu_ksoftirqd()) |
fe44d621 | 1925 | __this_cpu_add(cpu_softirq_time, delta); |
b52bfee4 | 1926 | |
8e92c201 | 1927 | irq_time_write_end(); |
b52bfee4 VP |
1928 | local_irq_restore(flags); |
1929 | } | |
b7dadc38 | 1930 | EXPORT_SYMBOL_GPL(account_system_vtime); |
b52bfee4 | 1931 | |
e6e6685a GC |
1932 | #endif /* CONFIG_IRQ_TIME_ACCOUNTING */ |
1933 | ||
1934 | #ifdef CONFIG_PARAVIRT | |
1935 | static inline u64 steal_ticks(u64 steal) | |
aa483808 | 1936 | { |
e6e6685a GC |
1937 | if (unlikely(steal > NSEC_PER_SEC)) |
1938 | return div_u64(steal, TICK_NSEC); | |
fe44d621 | 1939 | |
e6e6685a GC |
1940 | return __iter_div_u64_rem(steal, TICK_NSEC, &steal); |
1941 | } | |
1942 | #endif | |
1943 | ||
fe44d621 | 1944 | static void update_rq_clock_task(struct rq *rq, s64 delta) |
aa483808 | 1945 | { |
095c0aa8 GC |
1946 | /* |
1947 | * In theory, the compile should just see 0 here, and optimize out the call | |
1948 | * to sched_rt_avg_update. But I don't trust it... | |
1949 | */ | |
1950 | #if defined(CONFIG_IRQ_TIME_ACCOUNTING) || defined(CONFIG_PARAVIRT_TIME_ACCOUNTING) | |
1951 | s64 steal = 0, irq_delta = 0; | |
1952 | #endif | |
1953 | #ifdef CONFIG_IRQ_TIME_ACCOUNTING | |
8e92c201 | 1954 | irq_delta = irq_time_read(cpu_of(rq)) - rq->prev_irq_time; |
fe44d621 PZ |
1955 | |
1956 | /* | |
1957 | * Since irq_time is only updated on {soft,}irq_exit, we might run into | |
1958 | * this case when a previous update_rq_clock() happened inside a | |
1959 | * {soft,}irq region. | |
1960 | * | |
1961 | * When this happens, we stop ->clock_task and only update the | |
1962 | * prev_irq_time stamp to account for the part that fit, so that a next | |
1963 | * update will consume the rest. This ensures ->clock_task is | |
1964 | * monotonic. | |
1965 | * | |
1966 | * It does however cause some slight miss-attribution of {soft,}irq | |
1967 | * time, a more accurate solution would be to update the irq_time using | |
1968 | * the current rq->clock timestamp, except that would require using | |
1969 | * atomic ops. | |
1970 | */ | |
1971 | if (irq_delta > delta) | |
1972 | irq_delta = delta; | |
1973 | ||
1974 | rq->prev_irq_time += irq_delta; | |
1975 | delta -= irq_delta; | |
095c0aa8 GC |
1976 | #endif |
1977 | #ifdef CONFIG_PARAVIRT_TIME_ACCOUNTING | |
1978 | if (static_branch((¶virt_steal_rq_enabled))) { | |
1979 | u64 st; | |
1980 | ||
1981 | steal = paravirt_steal_clock(cpu_of(rq)); | |
1982 | steal -= rq->prev_steal_time_rq; | |
1983 | ||
1984 | if (unlikely(steal > delta)) | |
1985 | steal = delta; | |
1986 | ||
1987 | st = steal_ticks(steal); | |
1988 | steal = st * TICK_NSEC; | |
1989 | ||
1990 | rq->prev_steal_time_rq += steal; | |
1991 | ||
1992 | delta -= steal; | |
1993 | } | |
1994 | #endif | |
1995 | ||
fe44d621 PZ |
1996 | rq->clock_task += delta; |
1997 | ||
095c0aa8 GC |
1998 | #if defined(CONFIG_IRQ_TIME_ACCOUNTING) || defined(CONFIG_PARAVIRT_TIME_ACCOUNTING) |
1999 | if ((irq_delta + steal) && sched_feat(NONTASK_POWER)) | |
2000 | sched_rt_avg_update(rq, irq_delta + steal); | |
2001 | #endif | |
aa483808 VP |
2002 | } |
2003 | ||
095c0aa8 | 2004 | #ifdef CONFIG_IRQ_TIME_ACCOUNTING |
abb74cef VP |
2005 | static int irqtime_account_hi_update(void) |
2006 | { | |
2007 | struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat; | |
2008 | unsigned long flags; | |
2009 | u64 latest_ns; | |
2010 | int ret = 0; | |
2011 | ||
2012 | local_irq_save(flags); | |
2013 | latest_ns = this_cpu_read(cpu_hardirq_time); | |
2014 | if (cputime64_gt(nsecs_to_cputime64(latest_ns), cpustat->irq)) | |
2015 | ret = 1; | |
2016 | local_irq_restore(flags); | |
2017 | return ret; | |
2018 | } | |
2019 | ||
2020 | static int irqtime_account_si_update(void) | |
2021 | { | |
2022 | struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat; | |
2023 | unsigned long flags; | |
2024 | u64 latest_ns; | |
2025 | int ret = 0; | |
2026 | ||
2027 | local_irq_save(flags); | |
2028 | latest_ns = this_cpu_read(cpu_softirq_time); | |
2029 | if (cputime64_gt(nsecs_to_cputime64(latest_ns), cpustat->softirq)) | |
2030 | ret = 1; | |
2031 | local_irq_restore(flags); | |
2032 | return ret; | |
2033 | } | |
2034 | ||
fe44d621 | 2035 | #else /* CONFIG_IRQ_TIME_ACCOUNTING */ |
305e6835 | 2036 | |
abb74cef VP |
2037 | #define sched_clock_irqtime (0) |
2038 | ||
095c0aa8 | 2039 | #endif |
b52bfee4 | 2040 | |
1e3c88bd PZ |
2041 | #include "sched_idletask.c" |
2042 | #include "sched_fair.c" | |
2043 | #include "sched_rt.c" | |
5091faa4 | 2044 | #include "sched_autogroup.c" |
34f971f6 | 2045 | #include "sched_stoptask.c" |
1e3c88bd PZ |
2046 | #ifdef CONFIG_SCHED_DEBUG |
2047 | # include "sched_debug.c" | |
2048 | #endif | |
2049 | ||
34f971f6 PZ |
2050 | void sched_set_stop_task(int cpu, struct task_struct *stop) |
2051 | { | |
2052 | struct sched_param param = { .sched_priority = MAX_RT_PRIO - 1 }; | |
2053 | struct task_struct *old_stop = cpu_rq(cpu)->stop; | |
2054 | ||
2055 | if (stop) { | |
2056 | /* | |
2057 | * Make it appear like a SCHED_FIFO task, its something | |
2058 | * userspace knows about and won't get confused about. | |
2059 | * | |
2060 | * Also, it will make PI more or less work without too | |
2061 | * much confusion -- but then, stop work should not | |
2062 | * rely on PI working anyway. | |
2063 | */ | |
2064 | sched_setscheduler_nocheck(stop, SCHED_FIFO, ¶m); | |
2065 | ||
2066 | stop->sched_class = &stop_sched_class; | |
2067 | } | |
2068 | ||
2069 | cpu_rq(cpu)->stop = stop; | |
2070 | ||
2071 | if (old_stop) { | |
2072 | /* | |
2073 | * Reset it back to a normal scheduling class so that | |
2074 | * it can die in pieces. | |
2075 | */ | |
2076 | old_stop->sched_class = &rt_sched_class; | |
2077 | } | |
2078 | } | |
2079 | ||
14531189 | 2080 | /* |
dd41f596 | 2081 | * __normal_prio - return the priority that is based on the static prio |
14531189 | 2082 | */ |
14531189 IM |
2083 | static inline int __normal_prio(struct task_struct *p) |
2084 | { | |
dd41f596 | 2085 | return p->static_prio; |
14531189 IM |
2086 | } |
2087 | ||
b29739f9 IM |
2088 | /* |
2089 | * Calculate the expected normal priority: i.e. priority | |
2090 | * without taking RT-inheritance into account. Might be | |
2091 | * boosted by interactivity modifiers. Changes upon fork, | |
2092 | * setprio syscalls, and whenever the interactivity | |
2093 | * estimator recalculates. | |
2094 | */ | |
36c8b586 | 2095 | static inline int normal_prio(struct task_struct *p) |
b29739f9 IM |
2096 | { |
2097 | int prio; | |
2098 | ||
e05606d3 | 2099 | if (task_has_rt_policy(p)) |
b29739f9 IM |
2100 | prio = MAX_RT_PRIO-1 - p->rt_priority; |
2101 | else | |
2102 | prio = __normal_prio(p); | |
2103 | return prio; | |
2104 | } | |
2105 | ||
2106 | /* | |
2107 | * Calculate the current priority, i.e. the priority | |
2108 | * taken into account by the scheduler. This value might | |
2109 | * be boosted by RT tasks, or might be boosted by | |
2110 | * interactivity modifiers. Will be RT if the task got | |
2111 | * RT-boosted. If not then it returns p->normal_prio. | |
2112 | */ | |
36c8b586 | 2113 | static int effective_prio(struct task_struct *p) |
b29739f9 IM |
2114 | { |
2115 | p->normal_prio = normal_prio(p); | |
2116 | /* | |
2117 | * If we are RT tasks or we were boosted to RT priority, | |
2118 | * keep the priority unchanged. Otherwise, update priority | |
2119 | * to the normal priority: | |
2120 | */ | |
2121 | if (!rt_prio(p->prio)) | |
2122 | return p->normal_prio; | |
2123 | return p->prio; | |
2124 | } | |
2125 | ||
1da177e4 LT |
2126 | /** |
2127 | * task_curr - is this task currently executing on a CPU? | |
2128 | * @p: the task in question. | |
2129 | */ | |
36c8b586 | 2130 | inline int task_curr(const struct task_struct *p) |
1da177e4 LT |
2131 | { |
2132 | return cpu_curr(task_cpu(p)) == p; | |
2133 | } | |
2134 | ||
cb469845 SR |
2135 | static inline void check_class_changed(struct rq *rq, struct task_struct *p, |
2136 | const struct sched_class *prev_class, | |
da7a735e | 2137 | int oldprio) |
cb469845 SR |
2138 | { |
2139 | if (prev_class != p->sched_class) { | |
2140 | if (prev_class->switched_from) | |
da7a735e PZ |
2141 | prev_class->switched_from(rq, p); |
2142 | p->sched_class->switched_to(rq, p); | |
2143 | } else if (oldprio != p->prio) | |
2144 | p->sched_class->prio_changed(rq, p, oldprio); | |
cb469845 SR |
2145 | } |
2146 | ||
1e5a7405 PZ |
2147 | static void check_preempt_curr(struct rq *rq, struct task_struct *p, int flags) |
2148 | { | |
2149 | const struct sched_class *class; | |
2150 | ||
2151 | if (p->sched_class == rq->curr->sched_class) { | |
2152 | rq->curr->sched_class->check_preempt_curr(rq, p, flags); | |
2153 | } else { | |
2154 | for_each_class(class) { | |
2155 | if (class == rq->curr->sched_class) | |
2156 | break; | |
2157 | if (class == p->sched_class) { | |
2158 | resched_task(rq->curr); | |
2159 | break; | |
2160 | } | |
2161 | } | |
2162 | } | |
2163 | ||
2164 | /* | |
2165 | * A queue event has occurred, and we're going to schedule. In | |
2166 | * this case, we can save a useless back to back clock update. | |
2167 | */ | |
fd2f4419 | 2168 | if (rq->curr->on_rq && test_tsk_need_resched(rq->curr)) |
1e5a7405 PZ |
2169 | rq->skip_clock_update = 1; |
2170 | } | |
2171 | ||
1da177e4 | 2172 | #ifdef CONFIG_SMP |
cc367732 IM |
2173 | /* |
2174 | * Is this task likely cache-hot: | |
2175 | */ | |
e7693a36 | 2176 | static int |
cc367732 IM |
2177 | task_hot(struct task_struct *p, u64 now, struct sched_domain *sd) |
2178 | { | |
2179 | s64 delta; | |
2180 | ||
e6c8fba7 PZ |
2181 | if (p->sched_class != &fair_sched_class) |
2182 | return 0; | |
2183 | ||
ef8002f6 NR |
2184 | if (unlikely(p->policy == SCHED_IDLE)) |
2185 | return 0; | |
2186 | ||
f540a608 IM |
2187 | /* |
2188 | * Buddy candidates are cache hot: | |
2189 | */ | |
f685ceac | 2190 | if (sched_feat(CACHE_HOT_BUDDY) && this_rq()->nr_running && |
4793241b PZ |
2191 | (&p->se == cfs_rq_of(&p->se)->next || |
2192 | &p->se == cfs_rq_of(&p->se)->last)) | |
f540a608 IM |
2193 | return 1; |
2194 | ||
6bc1665b IM |
2195 | if (sysctl_sched_migration_cost == -1) |
2196 | return 1; | |
2197 | if (sysctl_sched_migration_cost == 0) | |
2198 | return 0; | |
2199 | ||
cc367732 IM |
2200 | delta = now - p->se.exec_start; |
2201 | ||
2202 | return delta < (s64)sysctl_sched_migration_cost; | |
2203 | } | |
2204 | ||
dd41f596 | 2205 | void set_task_cpu(struct task_struct *p, unsigned int new_cpu) |
c65cc870 | 2206 | { |
e2912009 PZ |
2207 | #ifdef CONFIG_SCHED_DEBUG |
2208 | /* | |
2209 | * We should never call set_task_cpu() on a blocked task, | |
2210 | * ttwu() will sort out the placement. | |
2211 | */ | |
077614ee PZ |
2212 | WARN_ON_ONCE(p->state != TASK_RUNNING && p->state != TASK_WAKING && |
2213 | !(task_thread_info(p)->preempt_count & PREEMPT_ACTIVE)); | |
0122ec5b PZ |
2214 | |
2215 | #ifdef CONFIG_LOCKDEP | |
6c6c54e1 PZ |
2216 | /* |
2217 | * The caller should hold either p->pi_lock or rq->lock, when changing | |
2218 | * a task's CPU. ->pi_lock for waking tasks, rq->lock for runnable tasks. | |
2219 | * | |
2220 | * sched_move_task() holds both and thus holding either pins the cgroup, | |
2221 | * see set_task_rq(). | |
2222 | * | |
2223 | * Furthermore, all task_rq users should acquire both locks, see | |
2224 | * task_rq_lock(). | |
2225 | */ | |
0122ec5b PZ |
2226 | WARN_ON_ONCE(debug_locks && !(lockdep_is_held(&p->pi_lock) || |
2227 | lockdep_is_held(&task_rq(p)->lock))); | |
2228 | #endif | |
e2912009 PZ |
2229 | #endif |
2230 | ||
de1d7286 | 2231 | trace_sched_migrate_task(p, new_cpu); |
cbc34ed1 | 2232 | |
0c69774e PZ |
2233 | if (task_cpu(p) != new_cpu) { |
2234 | p->se.nr_migrations++; | |
a8b0ca17 | 2235 | perf_sw_event(PERF_COUNT_SW_CPU_MIGRATIONS, 1, NULL, 0); |
0c69774e | 2236 | } |
dd41f596 IM |
2237 | |
2238 | __set_task_cpu(p, new_cpu); | |
c65cc870 IM |
2239 | } |
2240 | ||
969c7921 | 2241 | struct migration_arg { |
36c8b586 | 2242 | struct task_struct *task; |
1da177e4 | 2243 | int dest_cpu; |
70b97a7f | 2244 | }; |
1da177e4 | 2245 | |
969c7921 TH |
2246 | static int migration_cpu_stop(void *data); |
2247 | ||
1da177e4 LT |
2248 | /* |
2249 | * wait_task_inactive - wait for a thread to unschedule. | |
2250 | * | |
85ba2d86 RM |
2251 | * If @match_state is nonzero, it's the @p->state value just checked and |
2252 | * not expected to change. If it changes, i.e. @p might have woken up, | |
2253 | * then return zero. When we succeed in waiting for @p to be off its CPU, | |
2254 | * we return a positive number (its total switch count). If a second call | |
2255 | * a short while later returns the same number, the caller can be sure that | |
2256 | * @p has remained unscheduled the whole time. | |
2257 | * | |
1da177e4 LT |
2258 | * The caller must ensure that the task *will* unschedule sometime soon, |
2259 | * else this function might spin for a *long* time. This function can't | |
2260 | * be called with interrupts off, or it may introduce deadlock with | |
2261 | * smp_call_function() if an IPI is sent by the same process we are | |
2262 | * waiting to become inactive. | |
2263 | */ | |
85ba2d86 | 2264 | unsigned long wait_task_inactive(struct task_struct *p, long match_state) |
1da177e4 LT |
2265 | { |
2266 | unsigned long flags; | |
dd41f596 | 2267 | int running, on_rq; |
85ba2d86 | 2268 | unsigned long ncsw; |
70b97a7f | 2269 | struct rq *rq; |
1da177e4 | 2270 | |
3a5c359a AK |
2271 | for (;;) { |
2272 | /* | |
2273 | * We do the initial early heuristics without holding | |
2274 | * any task-queue locks at all. We'll only try to get | |
2275 | * the runqueue lock when things look like they will | |
2276 | * work out! | |
2277 | */ | |
2278 | rq = task_rq(p); | |
fa490cfd | 2279 | |
3a5c359a AK |
2280 | /* |
2281 | * If the task is actively running on another CPU | |
2282 | * still, just relax and busy-wait without holding | |
2283 | * any locks. | |
2284 | * | |
2285 | * NOTE! Since we don't hold any locks, it's not | |
2286 | * even sure that "rq" stays as the right runqueue! | |
2287 | * But we don't care, since "task_running()" will | |
2288 | * return false if the runqueue has changed and p | |
2289 | * is actually now running somewhere else! | |
2290 | */ | |
85ba2d86 RM |
2291 | while (task_running(rq, p)) { |
2292 | if (match_state && unlikely(p->state != match_state)) | |
2293 | return 0; | |
3a5c359a | 2294 | cpu_relax(); |
85ba2d86 | 2295 | } |
fa490cfd | 2296 | |
3a5c359a AK |
2297 | /* |
2298 | * Ok, time to look more closely! We need the rq | |
2299 | * lock now, to be *sure*. If we're wrong, we'll | |
2300 | * just go back and repeat. | |
2301 | */ | |
2302 | rq = task_rq_lock(p, &flags); | |
27a9da65 | 2303 | trace_sched_wait_task(p); |
3a5c359a | 2304 | running = task_running(rq, p); |
fd2f4419 | 2305 | on_rq = p->on_rq; |
85ba2d86 | 2306 | ncsw = 0; |
f31e11d8 | 2307 | if (!match_state || p->state == match_state) |
93dcf55f | 2308 | ncsw = p->nvcsw | LONG_MIN; /* sets MSB */ |
0122ec5b | 2309 | task_rq_unlock(rq, p, &flags); |
fa490cfd | 2310 | |
85ba2d86 RM |
2311 | /* |
2312 | * If it changed from the expected state, bail out now. | |
2313 | */ | |
2314 | if (unlikely(!ncsw)) | |
2315 | break; | |
2316 | ||
3a5c359a AK |
2317 | /* |
2318 | * Was it really running after all now that we | |
2319 | * checked with the proper locks actually held? | |
2320 | * | |
2321 | * Oops. Go back and try again.. | |
2322 | */ | |
2323 | if (unlikely(running)) { | |
2324 | cpu_relax(); | |
2325 | continue; | |
2326 | } | |
fa490cfd | 2327 | |
3a5c359a AK |
2328 | /* |
2329 | * It's not enough that it's not actively running, | |
2330 | * it must be off the runqueue _entirely_, and not | |
2331 | * preempted! | |
2332 | * | |
80dd99b3 | 2333 | * So if it was still runnable (but just not actively |
3a5c359a AK |
2334 | * running right now), it's preempted, and we should |
2335 | * yield - it could be a while. | |
2336 | */ | |
2337 | if (unlikely(on_rq)) { | |
8eb90c30 TG |
2338 | ktime_t to = ktime_set(0, NSEC_PER_SEC/HZ); |
2339 | ||
2340 | set_current_state(TASK_UNINTERRUPTIBLE); | |
2341 | schedule_hrtimeout(&to, HRTIMER_MODE_REL); | |
3a5c359a AK |
2342 | continue; |
2343 | } | |
fa490cfd | 2344 | |
3a5c359a AK |
2345 | /* |
2346 | * Ahh, all good. It wasn't running, and it wasn't | |
2347 | * runnable, which means that it will never become | |
2348 | * running in the future either. We're all done! | |
2349 | */ | |
2350 | break; | |
2351 | } | |
85ba2d86 RM |
2352 | |
2353 | return ncsw; | |
1da177e4 LT |
2354 | } |
2355 | ||
2356 | /*** | |
2357 | * kick_process - kick a running thread to enter/exit the kernel | |
2358 | * @p: the to-be-kicked thread | |
2359 | * | |
2360 | * Cause a process which is running on another CPU to enter | |
2361 | * kernel-mode, without any delay. (to get signals handled.) | |
2362 | * | |
25985edc | 2363 | * NOTE: this function doesn't have to take the runqueue lock, |
1da177e4 LT |
2364 | * because all it wants to ensure is that the remote task enters |
2365 | * the kernel. If the IPI races and the task has been migrated | |
2366 | * to another CPU then no harm is done and the purpose has been | |
2367 | * achieved as well. | |
2368 | */ | |
36c8b586 | 2369 | void kick_process(struct task_struct *p) |
1da177e4 LT |
2370 | { |
2371 | int cpu; | |
2372 | ||
2373 | preempt_disable(); | |
2374 | cpu = task_cpu(p); | |
2375 | if ((cpu != smp_processor_id()) && task_curr(p)) | |
2376 | smp_send_reschedule(cpu); | |
2377 | preempt_enable(); | |
2378 | } | |
b43e3521 | 2379 | EXPORT_SYMBOL_GPL(kick_process); |
476d139c | 2380 | #endif /* CONFIG_SMP */ |
1da177e4 | 2381 | |
970b13ba | 2382 | #ifdef CONFIG_SMP |
30da688e | 2383 | /* |
013fdb80 | 2384 | * ->cpus_allowed is protected by both rq->lock and p->pi_lock |
30da688e | 2385 | */ |
5da9a0fb PZ |
2386 | static int select_fallback_rq(int cpu, struct task_struct *p) |
2387 | { | |
2388 | int dest_cpu; | |
2389 | const struct cpumask *nodemask = cpumask_of_node(cpu_to_node(cpu)); | |
2390 | ||
2391 | /* Look for allowed, online CPU in same node. */ | |
2392 | for_each_cpu_and(dest_cpu, nodemask, cpu_active_mask) | |
2393 | if (cpumask_test_cpu(dest_cpu, &p->cpus_allowed)) | |
2394 | return dest_cpu; | |
2395 | ||
2396 | /* Any allowed, online CPU? */ | |
2397 | dest_cpu = cpumask_any_and(&p->cpus_allowed, cpu_active_mask); | |
2398 | if (dest_cpu < nr_cpu_ids) | |
2399 | return dest_cpu; | |
2400 | ||
2401 | /* No more Mr. Nice Guy. */ | |
48c5ccae PZ |
2402 | dest_cpu = cpuset_cpus_allowed_fallback(p); |
2403 | /* | |
2404 | * Don't tell them about moving exiting tasks or | |
2405 | * kernel threads (both mm NULL), since they never | |
2406 | * leave kernel. | |
2407 | */ | |
2408 | if (p->mm && printk_ratelimit()) { | |
2409 | printk(KERN_INFO "process %d (%s) no longer affine to cpu%d\n", | |
2410 | task_pid_nr(p), p->comm, cpu); | |
5da9a0fb PZ |
2411 | } |
2412 | ||
2413 | return dest_cpu; | |
2414 | } | |
2415 | ||
e2912009 | 2416 | /* |
013fdb80 | 2417 | * The caller (fork, wakeup) owns p->pi_lock, ->cpus_allowed is stable. |
e2912009 | 2418 | */ |
970b13ba | 2419 | static inline |
7608dec2 | 2420 | int select_task_rq(struct task_struct *p, int sd_flags, int wake_flags) |
970b13ba | 2421 | { |
7608dec2 | 2422 | int cpu = p->sched_class->select_task_rq(p, sd_flags, wake_flags); |
e2912009 PZ |
2423 | |
2424 | /* | |
2425 | * In order not to call set_task_cpu() on a blocking task we need | |
2426 | * to rely on ttwu() to place the task on a valid ->cpus_allowed | |
2427 | * cpu. | |
2428 | * | |
2429 | * Since this is common to all placement strategies, this lives here. | |
2430 | * | |
2431 | * [ this allows ->select_task() to simply return task_cpu(p) and | |
2432 | * not worry about this generic constraint ] | |
2433 | */ | |
2434 | if (unlikely(!cpumask_test_cpu(cpu, &p->cpus_allowed) || | |
70f11205 | 2435 | !cpu_online(cpu))) |
5da9a0fb | 2436 | cpu = select_fallback_rq(task_cpu(p), p); |
e2912009 PZ |
2437 | |
2438 | return cpu; | |
970b13ba | 2439 | } |
09a40af5 MG |
2440 | |
2441 | static void update_avg(u64 *avg, u64 sample) | |
2442 | { | |
2443 | s64 diff = sample - *avg; | |
2444 | *avg += diff >> 3; | |
2445 | } | |
970b13ba PZ |
2446 | #endif |
2447 | ||
d7c01d27 | 2448 | static void |
b84cb5df | 2449 | ttwu_stat(struct task_struct *p, int cpu, int wake_flags) |
9ed3811a | 2450 | { |
d7c01d27 | 2451 | #ifdef CONFIG_SCHEDSTATS |
b84cb5df PZ |
2452 | struct rq *rq = this_rq(); |
2453 | ||
d7c01d27 PZ |
2454 | #ifdef CONFIG_SMP |
2455 | int this_cpu = smp_processor_id(); | |
2456 | ||
2457 | if (cpu == this_cpu) { | |
2458 | schedstat_inc(rq, ttwu_local); | |
2459 | schedstat_inc(p, se.statistics.nr_wakeups_local); | |
2460 | } else { | |
2461 | struct sched_domain *sd; | |
2462 | ||
2463 | schedstat_inc(p, se.statistics.nr_wakeups_remote); | |
057f3fad | 2464 | rcu_read_lock(); |
d7c01d27 PZ |
2465 | for_each_domain(this_cpu, sd) { |
2466 | if (cpumask_test_cpu(cpu, sched_domain_span(sd))) { | |
2467 | schedstat_inc(sd, ttwu_wake_remote); | |
2468 | break; | |
2469 | } | |
2470 | } | |
057f3fad | 2471 | rcu_read_unlock(); |
d7c01d27 | 2472 | } |
f339b9dc PZ |
2473 | |
2474 | if (wake_flags & WF_MIGRATED) | |
2475 | schedstat_inc(p, se.statistics.nr_wakeups_migrate); | |
2476 | ||
d7c01d27 PZ |
2477 | #endif /* CONFIG_SMP */ |
2478 | ||
2479 | schedstat_inc(rq, ttwu_count); | |
9ed3811a | 2480 | schedstat_inc(p, se.statistics.nr_wakeups); |
d7c01d27 PZ |
2481 | |
2482 | if (wake_flags & WF_SYNC) | |
9ed3811a | 2483 | schedstat_inc(p, se.statistics.nr_wakeups_sync); |
d7c01d27 | 2484 | |
d7c01d27 PZ |
2485 | #endif /* CONFIG_SCHEDSTATS */ |
2486 | } | |
2487 | ||
2488 | static void ttwu_activate(struct rq *rq, struct task_struct *p, int en_flags) | |
2489 | { | |
9ed3811a | 2490 | activate_task(rq, p, en_flags); |
fd2f4419 | 2491 | p->on_rq = 1; |
c2f7115e PZ |
2492 | |
2493 | /* if a worker is waking up, notify workqueue */ | |
2494 | if (p->flags & PF_WQ_WORKER) | |
2495 | wq_worker_waking_up(p, cpu_of(rq)); | |
9ed3811a TH |
2496 | } |
2497 | ||
23f41eeb PZ |
2498 | /* |
2499 | * Mark the task runnable and perform wakeup-preemption. | |
2500 | */ | |
89363381 | 2501 | static void |
23f41eeb | 2502 | ttwu_do_wakeup(struct rq *rq, struct task_struct *p, int wake_flags) |
9ed3811a | 2503 | { |
89363381 | 2504 | trace_sched_wakeup(p, true); |
9ed3811a TH |
2505 | check_preempt_curr(rq, p, wake_flags); |
2506 | ||
2507 | p->state = TASK_RUNNING; | |
2508 | #ifdef CONFIG_SMP | |
2509 | if (p->sched_class->task_woken) | |
2510 | p->sched_class->task_woken(rq, p); | |
2511 | ||
e69c6341 | 2512 | if (rq->idle_stamp) { |
9ed3811a TH |
2513 | u64 delta = rq->clock - rq->idle_stamp; |
2514 | u64 max = 2*sysctl_sched_migration_cost; | |
2515 | ||
2516 | if (delta > max) | |
2517 | rq->avg_idle = max; | |
2518 | else | |
2519 | update_avg(&rq->avg_idle, delta); | |
2520 | rq->idle_stamp = 0; | |
2521 | } | |
2522 | #endif | |
2523 | } | |
2524 | ||
c05fbafb PZ |
2525 | static void |
2526 | ttwu_do_activate(struct rq *rq, struct task_struct *p, int wake_flags) | |
2527 | { | |
2528 | #ifdef CONFIG_SMP | |
2529 | if (p->sched_contributes_to_load) | |
2530 | rq->nr_uninterruptible--; | |
2531 | #endif | |
2532 | ||
2533 | ttwu_activate(rq, p, ENQUEUE_WAKEUP | ENQUEUE_WAKING); | |
2534 | ttwu_do_wakeup(rq, p, wake_flags); | |
2535 | } | |
2536 | ||
2537 | /* | |
2538 | * Called in case the task @p isn't fully descheduled from its runqueue, | |
2539 | * in this case we must do a remote wakeup. Its a 'light' wakeup though, | |
2540 | * since all we need to do is flip p->state to TASK_RUNNING, since | |
2541 | * the task is still ->on_rq. | |
2542 | */ | |
2543 | static int ttwu_remote(struct task_struct *p, int wake_flags) | |
2544 | { | |
2545 | struct rq *rq; | |
2546 | int ret = 0; | |
2547 | ||
2548 | rq = __task_rq_lock(p); | |
2549 | if (p->on_rq) { | |
2550 | ttwu_do_wakeup(rq, p, wake_flags); | |
2551 | ret = 1; | |
2552 | } | |
2553 | __task_rq_unlock(rq); | |
2554 | ||
2555 | return ret; | |
2556 | } | |
2557 | ||
317f3941 | 2558 | #ifdef CONFIG_SMP |
c5d753a5 | 2559 | static void sched_ttwu_do_pending(struct task_struct *list) |
317f3941 PZ |
2560 | { |
2561 | struct rq *rq = this_rq(); | |
317f3941 PZ |
2562 | |
2563 | raw_spin_lock(&rq->lock); | |
2564 | ||
2565 | while (list) { | |
2566 | struct task_struct *p = list; | |
2567 | list = list->wake_entry; | |
2568 | ttwu_do_activate(rq, p, 0); | |
2569 | } | |
2570 | ||
2571 | raw_spin_unlock(&rq->lock); | |
2572 | } | |
2573 | ||
c5d753a5 PZ |
2574 | #ifdef CONFIG_HOTPLUG_CPU |
2575 | ||
2576 | static void sched_ttwu_pending(void) | |
2577 | { | |
2578 | struct rq *rq = this_rq(); | |
2579 | struct task_struct *list = xchg(&rq->wake_list, NULL); | |
2580 | ||
2581 | if (!list) | |
2582 | return; | |
2583 | ||
2584 | sched_ttwu_do_pending(list); | |
2585 | } | |
2586 | ||
2587 | #endif /* CONFIG_HOTPLUG_CPU */ | |
2588 | ||
317f3941 PZ |
2589 | void scheduler_ipi(void) |
2590 | { | |
c5d753a5 PZ |
2591 | struct rq *rq = this_rq(); |
2592 | struct task_struct *list = xchg(&rq->wake_list, NULL); | |
2593 | ||
2594 | if (!list) | |
2595 | return; | |
2596 | ||
2597 | /* | |
2598 | * Not all reschedule IPI handlers call irq_enter/irq_exit, since | |
2599 | * traditionally all their work was done from the interrupt return | |
2600 | * path. Now that we actually do some work, we need to make sure | |
2601 | * we do call them. | |
2602 | * | |
2603 | * Some archs already do call them, luckily irq_enter/exit nest | |
2604 | * properly. | |
2605 | * | |
2606 | * Arguably we should visit all archs and update all handlers, | |
2607 | * however a fair share of IPIs are still resched only so this would | |
2608 | * somewhat pessimize the simple resched case. | |
2609 | */ | |
2610 | irq_enter(); | |
2611 | sched_ttwu_do_pending(list); | |
2612 | irq_exit(); | |
317f3941 PZ |
2613 | } |
2614 | ||
2615 | static void ttwu_queue_remote(struct task_struct *p, int cpu) | |
2616 | { | |
2617 | struct rq *rq = cpu_rq(cpu); | |
2618 | struct task_struct *next = rq->wake_list; | |
2619 | ||
2620 | for (;;) { | |
2621 | struct task_struct *old = next; | |
2622 | ||
2623 | p->wake_entry = next; | |
2624 | next = cmpxchg(&rq->wake_list, old, p); | |
2625 | if (next == old) | |
2626 | break; | |
2627 | } | |
2628 | ||
2629 | if (!next) | |
2630 | smp_send_reschedule(cpu); | |
2631 | } | |
d6aa8f85 PZ |
2632 | |
2633 | #ifdef __ARCH_WANT_INTERRUPTS_ON_CTXSW | |
2634 | static int ttwu_activate_remote(struct task_struct *p, int wake_flags) | |
2635 | { | |
2636 | struct rq *rq; | |
2637 | int ret = 0; | |
2638 | ||
2639 | rq = __task_rq_lock(p); | |
2640 | if (p->on_cpu) { | |
2641 | ttwu_activate(rq, p, ENQUEUE_WAKEUP); | |
2642 | ttwu_do_wakeup(rq, p, wake_flags); | |
2643 | ret = 1; | |
2644 | } | |
2645 | __task_rq_unlock(rq); | |
2646 | ||
2647 | return ret; | |
2648 | ||
2649 | } | |
2650 | #endif /* __ARCH_WANT_INTERRUPTS_ON_CTXSW */ | |
2651 | #endif /* CONFIG_SMP */ | |
317f3941 | 2652 | |
c05fbafb PZ |
2653 | static void ttwu_queue(struct task_struct *p, int cpu) |
2654 | { | |
2655 | struct rq *rq = cpu_rq(cpu); | |
2656 | ||
17d9f311 | 2657 | #if defined(CONFIG_SMP) |
317f3941 | 2658 | if (sched_feat(TTWU_QUEUE) && cpu != smp_processor_id()) { |
f01114cb | 2659 | sched_clock_cpu(cpu); /* sync clocks x-cpu */ |
317f3941 PZ |
2660 | ttwu_queue_remote(p, cpu); |
2661 | return; | |
2662 | } | |
2663 | #endif | |
2664 | ||
c05fbafb PZ |
2665 | raw_spin_lock(&rq->lock); |
2666 | ttwu_do_activate(rq, p, 0); | |
2667 | raw_spin_unlock(&rq->lock); | |
9ed3811a TH |
2668 | } |
2669 | ||
2670 | /** | |
1da177e4 | 2671 | * try_to_wake_up - wake up a thread |
9ed3811a | 2672 | * @p: the thread to be awakened |
1da177e4 | 2673 | * @state: the mask of task states that can be woken |
9ed3811a | 2674 | * @wake_flags: wake modifier flags (WF_*) |
1da177e4 LT |
2675 | * |
2676 | * Put it on the run-queue if it's not already there. The "current" | |
2677 | * thread is always on the run-queue (except when the actual | |
2678 | * re-schedule is in progress), and as such you're allowed to do | |
2679 | * the simpler "current->state = TASK_RUNNING" to mark yourself | |
2680 | * runnable without the overhead of this. | |
2681 | * | |
9ed3811a TH |
2682 | * Returns %true if @p was woken up, %false if it was already running |
2683 | * or @state didn't match @p's state. | |
1da177e4 | 2684 | */ |
e4a52bcb PZ |
2685 | static int |
2686 | try_to_wake_up(struct task_struct *p, unsigned int state, int wake_flags) | |
1da177e4 | 2687 | { |
1da177e4 | 2688 | unsigned long flags; |
c05fbafb | 2689 | int cpu, success = 0; |
2398f2c6 | 2690 | |
04e2f174 | 2691 | smp_wmb(); |
013fdb80 | 2692 | raw_spin_lock_irqsave(&p->pi_lock, flags); |
e9c84311 | 2693 | if (!(p->state & state)) |
1da177e4 LT |
2694 | goto out; |
2695 | ||
c05fbafb | 2696 | success = 1; /* we're going to change ->state */ |
1da177e4 | 2697 | cpu = task_cpu(p); |
1da177e4 | 2698 | |
c05fbafb PZ |
2699 | if (p->on_rq && ttwu_remote(p, wake_flags)) |
2700 | goto stat; | |
1da177e4 | 2701 | |
1da177e4 | 2702 | #ifdef CONFIG_SMP |
e9c84311 | 2703 | /* |
c05fbafb PZ |
2704 | * If the owning (remote) cpu is still in the middle of schedule() with |
2705 | * this task as prev, wait until its done referencing the task. | |
e9c84311 | 2706 | */ |
e4a52bcb PZ |
2707 | while (p->on_cpu) { |
2708 | #ifdef __ARCH_WANT_INTERRUPTS_ON_CTXSW | |
2709 | /* | |
d6aa8f85 PZ |
2710 | * In case the architecture enables interrupts in |
2711 | * context_switch(), we cannot busy wait, since that | |
2712 | * would lead to deadlocks when an interrupt hits and | |
2713 | * tries to wake up @prev. So bail and do a complete | |
2714 | * remote wakeup. | |
e4a52bcb | 2715 | */ |
d6aa8f85 | 2716 | if (ttwu_activate_remote(p, wake_flags)) |
c05fbafb | 2717 | goto stat; |
d6aa8f85 | 2718 | #else |
e4a52bcb | 2719 | cpu_relax(); |
d6aa8f85 | 2720 | #endif |
371fd7e7 | 2721 | } |
0970d299 | 2722 | /* |
e4a52bcb | 2723 | * Pairs with the smp_wmb() in finish_lock_switch(). |
0970d299 | 2724 | */ |
e4a52bcb | 2725 | smp_rmb(); |
1da177e4 | 2726 | |
a8e4f2ea | 2727 | p->sched_contributes_to_load = !!task_contributes_to_load(p); |
e9c84311 | 2728 | p->state = TASK_WAKING; |
e7693a36 | 2729 | |
e4a52bcb | 2730 | if (p->sched_class->task_waking) |
74f8e4b2 | 2731 | p->sched_class->task_waking(p); |
efbbd05a | 2732 | |
7608dec2 | 2733 | cpu = select_task_rq(p, SD_BALANCE_WAKE, wake_flags); |
f339b9dc PZ |
2734 | if (task_cpu(p) != cpu) { |
2735 | wake_flags |= WF_MIGRATED; | |
e4a52bcb | 2736 | set_task_cpu(p, cpu); |
f339b9dc | 2737 | } |
1da177e4 | 2738 | #endif /* CONFIG_SMP */ |
1da177e4 | 2739 | |
c05fbafb PZ |
2740 | ttwu_queue(p, cpu); |
2741 | stat: | |
b84cb5df | 2742 | ttwu_stat(p, cpu, wake_flags); |
1da177e4 | 2743 | out: |
013fdb80 | 2744 | raw_spin_unlock_irqrestore(&p->pi_lock, flags); |
1da177e4 LT |
2745 | |
2746 | return success; | |
2747 | } | |
2748 | ||
21aa9af0 TH |
2749 | /** |
2750 | * try_to_wake_up_local - try to wake up a local task with rq lock held | |
2751 | * @p: the thread to be awakened | |
2752 | * | |
2acca55e | 2753 | * Put @p on the run-queue if it's not already there. The caller must |
21aa9af0 | 2754 | * ensure that this_rq() is locked, @p is bound to this_rq() and not |
2acca55e | 2755 | * the current task. |
21aa9af0 TH |
2756 | */ |
2757 | static void try_to_wake_up_local(struct task_struct *p) | |
2758 | { | |
2759 | struct rq *rq = task_rq(p); | |
21aa9af0 TH |
2760 | |
2761 | BUG_ON(rq != this_rq()); | |
2762 | BUG_ON(p == current); | |
2763 | lockdep_assert_held(&rq->lock); | |
2764 | ||
2acca55e PZ |
2765 | if (!raw_spin_trylock(&p->pi_lock)) { |
2766 | raw_spin_unlock(&rq->lock); | |
2767 | raw_spin_lock(&p->pi_lock); | |
2768 | raw_spin_lock(&rq->lock); | |
2769 | } | |
2770 | ||
21aa9af0 | 2771 | if (!(p->state & TASK_NORMAL)) |
2acca55e | 2772 | goto out; |
21aa9af0 | 2773 | |
fd2f4419 | 2774 | if (!p->on_rq) |
d7c01d27 PZ |
2775 | ttwu_activate(rq, p, ENQUEUE_WAKEUP); |
2776 | ||
23f41eeb | 2777 | ttwu_do_wakeup(rq, p, 0); |
b84cb5df | 2778 | ttwu_stat(p, smp_processor_id(), 0); |
2acca55e PZ |
2779 | out: |
2780 | raw_spin_unlock(&p->pi_lock); | |
21aa9af0 TH |
2781 | } |
2782 | ||
50fa610a DH |
2783 | /** |
2784 | * wake_up_process - Wake up a specific process | |
2785 | * @p: The process to be woken up. | |
2786 | * | |
2787 | * Attempt to wake up the nominated process and move it to the set of runnable | |
2788 | * processes. Returns 1 if the process was woken up, 0 if it was already | |
2789 | * running. | |
2790 | * | |
2791 | * It may be assumed that this function implies a write memory barrier before | |
2792 | * changing the task state if and only if any tasks are woken up. | |
2793 | */ | |
7ad5b3a5 | 2794 | int wake_up_process(struct task_struct *p) |
1da177e4 | 2795 | { |
d9514f6c | 2796 | return try_to_wake_up(p, TASK_ALL, 0); |
1da177e4 | 2797 | } |
1da177e4 LT |
2798 | EXPORT_SYMBOL(wake_up_process); |
2799 | ||
7ad5b3a5 | 2800 | int wake_up_state(struct task_struct *p, unsigned int state) |
1da177e4 LT |
2801 | { |
2802 | return try_to_wake_up(p, state, 0); | |
2803 | } | |
2804 | ||
1da177e4 LT |
2805 | /* |
2806 | * Perform scheduler related setup for a newly forked process p. | |
2807 | * p is forked by current. | |
dd41f596 IM |
2808 | * |
2809 | * __sched_fork() is basic setup used by init_idle() too: | |
2810 | */ | |
2811 | static void __sched_fork(struct task_struct *p) | |
2812 | { | |
fd2f4419 PZ |
2813 | p->on_rq = 0; |
2814 | ||
2815 | p->se.on_rq = 0; | |
dd41f596 IM |
2816 | p->se.exec_start = 0; |
2817 | p->se.sum_exec_runtime = 0; | |
f6cf891c | 2818 | p->se.prev_sum_exec_runtime = 0; |
6c594c21 | 2819 | p->se.nr_migrations = 0; |
da7a735e | 2820 | p->se.vruntime = 0; |
fd2f4419 | 2821 | INIT_LIST_HEAD(&p->se.group_node); |
6cfb0d5d IM |
2822 | |
2823 | #ifdef CONFIG_SCHEDSTATS | |
41acab88 | 2824 | memset(&p->se.statistics, 0, sizeof(p->se.statistics)); |
6cfb0d5d | 2825 | #endif |
476d139c | 2826 | |
fa717060 | 2827 | INIT_LIST_HEAD(&p->rt.run_list); |
476d139c | 2828 | |
e107be36 AK |
2829 | #ifdef CONFIG_PREEMPT_NOTIFIERS |
2830 | INIT_HLIST_HEAD(&p->preempt_notifiers); | |
2831 | #endif | |
dd41f596 IM |
2832 | } |
2833 | ||
2834 | /* | |
2835 | * fork()/clone()-time setup: | |
2836 | */ | |
3e51e3ed | 2837 | void sched_fork(struct task_struct *p) |
dd41f596 | 2838 | { |
0122ec5b | 2839 | unsigned long flags; |
dd41f596 IM |
2840 | int cpu = get_cpu(); |
2841 | ||
2842 | __sched_fork(p); | |
06b83b5f | 2843 | /* |
0017d735 | 2844 | * We mark the process as running here. This guarantees that |
06b83b5f PZ |
2845 | * nobody will actually run it, and a signal or other external |
2846 | * event cannot wake it up and insert it on the runqueue either. | |
2847 | */ | |
0017d735 | 2848 | p->state = TASK_RUNNING; |
dd41f596 | 2849 | |
b9dc29e7 MG |
2850 | /* |
2851 | * Revert to default priority/policy on fork if requested. | |
2852 | */ | |
2853 | if (unlikely(p->sched_reset_on_fork)) { | |
f83f9ac2 | 2854 | if (p->policy == SCHED_FIFO || p->policy == SCHED_RR) { |
b9dc29e7 | 2855 | p->policy = SCHED_NORMAL; |
f83f9ac2 PW |
2856 | p->normal_prio = p->static_prio; |
2857 | } | |
b9dc29e7 | 2858 | |
6c697bdf MG |
2859 | if (PRIO_TO_NICE(p->static_prio) < 0) { |
2860 | p->static_prio = NICE_TO_PRIO(0); | |
f83f9ac2 | 2861 | p->normal_prio = p->static_prio; |
6c697bdf MG |
2862 | set_load_weight(p); |
2863 | } | |
2864 | ||
b9dc29e7 MG |
2865 | /* |
2866 | * We don't need the reset flag anymore after the fork. It has | |
2867 | * fulfilled its duty: | |
2868 | */ | |
2869 | p->sched_reset_on_fork = 0; | |
2870 | } | |
ca94c442 | 2871 | |
f83f9ac2 PW |
2872 | /* |
2873 | * Make sure we do not leak PI boosting priority to the child. | |
2874 | */ | |
2875 | p->prio = current->normal_prio; | |
2876 | ||
2ddbf952 HS |
2877 | if (!rt_prio(p->prio)) |
2878 | p->sched_class = &fair_sched_class; | |
b29739f9 | 2879 | |
cd29fe6f PZ |
2880 | if (p->sched_class->task_fork) |
2881 | p->sched_class->task_fork(p); | |
2882 | ||
86951599 PZ |
2883 | /* |
2884 | * The child is not yet in the pid-hash so no cgroup attach races, | |
2885 | * and the cgroup is pinned to this child due to cgroup_fork() | |
2886 | * is ran before sched_fork(). | |
2887 | * | |
2888 | * Silence PROVE_RCU. | |
2889 | */ | |
0122ec5b | 2890 | raw_spin_lock_irqsave(&p->pi_lock, flags); |
5f3edc1b | 2891 | set_task_cpu(p, cpu); |
0122ec5b | 2892 | raw_spin_unlock_irqrestore(&p->pi_lock, flags); |
5f3edc1b | 2893 | |
52f17b6c | 2894 | #if defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT) |
dd41f596 | 2895 | if (likely(sched_info_on())) |
52f17b6c | 2896 | memset(&p->sched_info, 0, sizeof(p->sched_info)); |
1da177e4 | 2897 | #endif |
3ca7a440 PZ |
2898 | #if defined(CONFIG_SMP) |
2899 | p->on_cpu = 0; | |
4866cde0 | 2900 | #endif |
bdd4e85d | 2901 | #ifdef CONFIG_PREEMPT_COUNT |
4866cde0 | 2902 | /* Want to start with kernel preemption disabled. */ |
a1261f54 | 2903 | task_thread_info(p)->preempt_count = 1; |
1da177e4 | 2904 | #endif |
806c09a7 | 2905 | #ifdef CONFIG_SMP |
917b627d | 2906 | plist_node_init(&p->pushable_tasks, MAX_PRIO); |
806c09a7 | 2907 | #endif |
917b627d | 2908 | |
476d139c | 2909 | put_cpu(); |
1da177e4 LT |
2910 | } |
2911 | ||
2912 | /* | |
2913 | * wake_up_new_task - wake up a newly created task for the first time. | |
2914 | * | |
2915 | * This function will do some initial scheduler statistics housekeeping | |
2916 | * that must be done for every newly created context, then puts the task | |
2917 | * on the runqueue and wakes it. | |
2918 | */ | |
3e51e3ed | 2919 | void wake_up_new_task(struct task_struct *p) |
1da177e4 LT |
2920 | { |
2921 | unsigned long flags; | |
dd41f596 | 2922 | struct rq *rq; |
fabf318e | 2923 | |
ab2515c4 | 2924 | raw_spin_lock_irqsave(&p->pi_lock, flags); |
fabf318e PZ |
2925 | #ifdef CONFIG_SMP |
2926 | /* | |
2927 | * Fork balancing, do it here and not earlier because: | |
2928 | * - cpus_allowed can change in the fork path | |
2929 | * - any previously selected cpu might disappear through hotplug | |
fabf318e | 2930 | */ |
ab2515c4 | 2931 | set_task_cpu(p, select_task_rq(p, SD_BALANCE_FORK, 0)); |
0017d735 PZ |
2932 | #endif |
2933 | ||
ab2515c4 | 2934 | rq = __task_rq_lock(p); |
cd29fe6f | 2935 | activate_task(rq, p, 0); |
fd2f4419 | 2936 | p->on_rq = 1; |
89363381 | 2937 | trace_sched_wakeup_new(p, true); |
a7558e01 | 2938 | check_preempt_curr(rq, p, WF_FORK); |
9a897c5a | 2939 | #ifdef CONFIG_SMP |
efbbd05a PZ |
2940 | if (p->sched_class->task_woken) |
2941 | p->sched_class->task_woken(rq, p); | |
9a897c5a | 2942 | #endif |
0122ec5b | 2943 | task_rq_unlock(rq, p, &flags); |
1da177e4 LT |
2944 | } |
2945 | ||
e107be36 AK |
2946 | #ifdef CONFIG_PREEMPT_NOTIFIERS |
2947 | ||
2948 | /** | |
80dd99b3 | 2949 | * preempt_notifier_register - tell me when current is being preempted & rescheduled |
421cee29 | 2950 | * @notifier: notifier struct to register |
e107be36 AK |
2951 | */ |
2952 | void preempt_notifier_register(struct preempt_notifier *notifier) | |
2953 | { | |
2954 | hlist_add_head(¬ifier->link, ¤t->preempt_notifiers); | |
2955 | } | |
2956 | EXPORT_SYMBOL_GPL(preempt_notifier_register); | |
2957 | ||
2958 | /** | |
2959 | * preempt_notifier_unregister - no longer interested in preemption notifications | |
421cee29 | 2960 | * @notifier: notifier struct to unregister |
e107be36 AK |
2961 | * |
2962 | * This is safe to call from within a preemption notifier. | |
2963 | */ | |
2964 | void preempt_notifier_unregister(struct preempt_notifier *notifier) | |
2965 | { | |
2966 | hlist_del(¬ifier->link); | |
2967 | } | |
2968 | EXPORT_SYMBOL_GPL(preempt_notifier_unregister); | |
2969 | ||
2970 | static void fire_sched_in_preempt_notifiers(struct task_struct *curr) | |
2971 | { | |
2972 | struct preempt_notifier *notifier; | |
2973 | struct hlist_node *node; | |
2974 | ||
2975 | hlist_for_each_entry(notifier, node, &curr->preempt_notifiers, link) | |
2976 | notifier->ops->sched_in(notifier, raw_smp_processor_id()); | |
2977 | } | |
2978 | ||
2979 | static void | |
2980 | fire_sched_out_preempt_notifiers(struct task_struct *curr, | |
2981 | struct task_struct *next) | |
2982 | { | |
2983 | struct preempt_notifier *notifier; | |
2984 | struct hlist_node *node; | |
2985 | ||
2986 | hlist_for_each_entry(notifier, node, &curr->preempt_notifiers, link) | |
2987 | notifier->ops->sched_out(notifier, next); | |
2988 | } | |
2989 | ||
6d6bc0ad | 2990 | #else /* !CONFIG_PREEMPT_NOTIFIERS */ |
e107be36 AK |
2991 | |
2992 | static void fire_sched_in_preempt_notifiers(struct task_struct *curr) | |
2993 | { | |
2994 | } | |
2995 | ||
2996 | static void | |
2997 | fire_sched_out_preempt_notifiers(struct task_struct *curr, | |
2998 | struct task_struct *next) | |
2999 | { | |
3000 | } | |
3001 | ||
6d6bc0ad | 3002 | #endif /* CONFIG_PREEMPT_NOTIFIERS */ |
e107be36 | 3003 | |
4866cde0 NP |
3004 | /** |
3005 | * prepare_task_switch - prepare to switch tasks | |
3006 | * @rq: the runqueue preparing to switch | |
421cee29 | 3007 | * @prev: the current task that is being switched out |
4866cde0 NP |
3008 | * @next: the task we are going to switch to. |
3009 | * | |
3010 | * This is called with the rq lock held and interrupts off. It must | |
3011 | * be paired with a subsequent finish_task_switch after the context | |
3012 | * switch. | |
3013 | * | |
3014 | * prepare_task_switch sets up locking and calls architecture specific | |
3015 | * hooks. | |
3016 | */ | |
e107be36 AK |
3017 | static inline void |
3018 | prepare_task_switch(struct rq *rq, struct task_struct *prev, | |
3019 | struct task_struct *next) | |
4866cde0 | 3020 | { |
fe4b04fa PZ |
3021 | sched_info_switch(prev, next); |
3022 | perf_event_task_sched_out(prev, next); | |
e107be36 | 3023 | fire_sched_out_preempt_notifiers(prev, next); |
4866cde0 NP |
3024 | prepare_lock_switch(rq, next); |
3025 | prepare_arch_switch(next); | |
fe4b04fa | 3026 | trace_sched_switch(prev, next); |
4866cde0 NP |
3027 | } |
3028 | ||
1da177e4 LT |
3029 | /** |
3030 | * finish_task_switch - clean up after a task-switch | |
344babaa | 3031 | * @rq: runqueue associated with task-switch |
1da177e4 LT |
3032 | * @prev: the thread we just switched away from. |
3033 | * | |
4866cde0 NP |
3034 | * finish_task_switch must be called after the context switch, paired |
3035 | * with a prepare_task_switch call before the context switch. | |
3036 | * finish_task_switch will reconcile locking set up by prepare_task_switch, | |
3037 | * and do any other architecture-specific cleanup actions. | |
1da177e4 LT |
3038 | * |
3039 | * Note that we may have delayed dropping an mm in context_switch(). If | |
41a2d6cf | 3040 | * so, we finish that here outside of the runqueue lock. (Doing it |
1da177e4 LT |
3041 | * with the lock held can cause deadlocks; see schedule() for |
3042 | * details.) | |
3043 | */ | |
a9957449 | 3044 | static void finish_task_switch(struct rq *rq, struct task_struct *prev) |
1da177e4 LT |
3045 | __releases(rq->lock) |
3046 | { | |
1da177e4 | 3047 | struct mm_struct *mm = rq->prev_mm; |
55a101f8 | 3048 | long prev_state; |
1da177e4 LT |
3049 | |
3050 | rq->prev_mm = NULL; | |
3051 | ||
3052 | /* | |
3053 | * A task struct has one reference for the use as "current". | |
c394cc9f | 3054 | * If a task dies, then it sets TASK_DEAD in tsk->state and calls |
55a101f8 ON |
3055 | * schedule one last time. The schedule call will never return, and |
3056 | * the scheduled task must drop that reference. | |
c394cc9f | 3057 | * The test for TASK_DEAD must occur while the runqueue locks are |
1da177e4 LT |
3058 | * still held, otherwise prev could be scheduled on another cpu, die |
3059 | * there before we look at prev->state, and then the reference would | |
3060 | * be dropped twice. | |
3061 | * Manfred Spraul <manfred@colorfullife.com> | |
3062 | */ | |
55a101f8 | 3063 | prev_state = prev->state; |
4866cde0 | 3064 | finish_arch_switch(prev); |
8381f65d JI |
3065 | #ifdef __ARCH_WANT_INTERRUPTS_ON_CTXSW |
3066 | local_irq_disable(); | |
3067 | #endif /* __ARCH_WANT_INTERRUPTS_ON_CTXSW */ | |
49f47433 | 3068 | perf_event_task_sched_in(current); |
8381f65d JI |
3069 | #ifdef __ARCH_WANT_INTERRUPTS_ON_CTXSW |
3070 | local_irq_enable(); | |
3071 | #endif /* __ARCH_WANT_INTERRUPTS_ON_CTXSW */ | |
4866cde0 | 3072 | finish_lock_switch(rq, prev); |
e8fa1362 | 3073 | |
e107be36 | 3074 | fire_sched_in_preempt_notifiers(current); |
1da177e4 LT |
3075 | if (mm) |
3076 | mmdrop(mm); | |
c394cc9f | 3077 | if (unlikely(prev_state == TASK_DEAD)) { |
c6fd91f0 | 3078 | /* |
3079 | * Remove function-return probe instances associated with this | |
3080 | * task and put them back on the free list. | |
9761eea8 | 3081 | */ |
c6fd91f0 | 3082 | kprobe_flush_task(prev); |
1da177e4 | 3083 | put_task_struct(prev); |
c6fd91f0 | 3084 | } |
1da177e4 LT |
3085 | } |
3086 | ||
3f029d3c GH |
3087 | #ifdef CONFIG_SMP |
3088 | ||
3089 | /* assumes rq->lock is held */ | |
3090 | static inline void pre_schedule(struct rq *rq, struct task_struct *prev) | |
3091 | { | |
3092 | if (prev->sched_class->pre_schedule) | |
3093 | prev->sched_class->pre_schedule(rq, prev); | |
3094 | } | |
3095 | ||
3096 | /* rq->lock is NOT held, but preemption is disabled */ | |
3097 | static inline void post_schedule(struct rq *rq) | |
3098 | { | |
3099 | if (rq->post_schedule) { | |
3100 | unsigned long flags; | |
3101 | ||
05fa785c | 3102 | raw_spin_lock_irqsave(&rq->lock, flags); |
3f029d3c GH |
3103 | if (rq->curr->sched_class->post_schedule) |
3104 | rq->curr->sched_class->post_schedule(rq); | |
05fa785c | 3105 | raw_spin_unlock_irqrestore(&rq->lock, flags); |
3f029d3c GH |
3106 | |
3107 | rq->post_schedule = 0; | |
3108 | } | |
3109 | } | |
3110 | ||
3111 | #else | |
da19ab51 | 3112 | |
3f029d3c GH |
3113 | static inline void pre_schedule(struct rq *rq, struct task_struct *p) |
3114 | { | |
3115 | } | |
3116 | ||
3117 | static inline void post_schedule(struct rq *rq) | |
3118 | { | |
1da177e4 LT |
3119 | } |
3120 | ||
3f029d3c GH |
3121 | #endif |
3122 | ||
1da177e4 LT |
3123 | /** |
3124 | * schedule_tail - first thing a freshly forked thread must call. | |
3125 | * @prev: the thread we just switched away from. | |
3126 | */ | |
36c8b586 | 3127 | asmlinkage void schedule_tail(struct task_struct *prev) |
1da177e4 LT |
3128 | __releases(rq->lock) |
3129 | { | |
70b97a7f IM |
3130 | struct rq *rq = this_rq(); |
3131 | ||
4866cde0 | 3132 | finish_task_switch(rq, prev); |
da19ab51 | 3133 | |
3f029d3c GH |
3134 | /* |
3135 | * FIXME: do we need to worry about rq being invalidated by the | |
3136 | * task_switch? | |
3137 | */ | |
3138 | post_schedule(rq); | |
70b97a7f | 3139 | |
4866cde0 NP |
3140 | #ifdef __ARCH_WANT_UNLOCKED_CTXSW |
3141 | /* In this case, finish_task_switch does not reenable preemption */ | |
3142 | preempt_enable(); | |
3143 | #endif | |
1da177e4 | 3144 | if (current->set_child_tid) |
b488893a | 3145 | put_user(task_pid_vnr(current), current->set_child_tid); |
1da177e4 LT |
3146 | } |
3147 | ||
3148 | /* | |
3149 | * context_switch - switch to the new MM and the new | |
3150 | * thread's register state. | |
3151 | */ | |
dd41f596 | 3152 | static inline void |
70b97a7f | 3153 | context_switch(struct rq *rq, struct task_struct *prev, |
36c8b586 | 3154 | struct task_struct *next) |
1da177e4 | 3155 | { |
dd41f596 | 3156 | struct mm_struct *mm, *oldmm; |
1da177e4 | 3157 | |
e107be36 | 3158 | prepare_task_switch(rq, prev, next); |
fe4b04fa | 3159 | |
dd41f596 IM |
3160 | mm = next->mm; |
3161 | oldmm = prev->active_mm; | |
9226d125 ZA |
3162 | /* |
3163 | * For paravirt, this is coupled with an exit in switch_to to | |
3164 | * combine the page table reload and the switch backend into | |
3165 | * one hypercall. | |
3166 | */ | |
224101ed | 3167 | arch_start_context_switch(prev); |
9226d125 | 3168 | |
31915ab4 | 3169 | if (!mm) { |
1da177e4 LT |
3170 | next->active_mm = oldmm; |
3171 | atomic_inc(&oldmm->mm_count); | |
3172 | enter_lazy_tlb(oldmm, next); | |
3173 | } else | |
3174 | switch_mm(oldmm, mm, next); | |
3175 | ||
31915ab4 | 3176 | if (!prev->mm) { |
1da177e4 | 3177 | prev->active_mm = NULL; |
1da177e4 LT |
3178 | rq->prev_mm = oldmm; |
3179 | } | |
3a5f5e48 IM |
3180 | /* |
3181 | * Since the runqueue lock will be released by the next | |
3182 | * task (which is an invalid locking op but in the case | |
3183 | * of the scheduler it's an obvious special-case), so we | |
3184 | * do an early lockdep release here: | |
3185 | */ | |
3186 | #ifndef __ARCH_WANT_UNLOCKED_CTXSW | |
8a25d5de | 3187 | spin_release(&rq->lock.dep_map, 1, _THIS_IP_); |
3a5f5e48 | 3188 | #endif |
1da177e4 LT |
3189 | |
3190 | /* Here we just switch the register state and the stack. */ | |
3191 | switch_to(prev, next, prev); | |
3192 | ||
dd41f596 IM |
3193 | barrier(); |
3194 | /* | |
3195 | * this_rq must be evaluated again because prev may have moved | |
3196 | * CPUs since it called schedule(), thus the 'rq' on its stack | |
3197 | * frame will be invalid. | |
3198 | */ | |
3199 | finish_task_switch(this_rq(), prev); | |
1da177e4 LT |
3200 | } |
3201 | ||
3202 | /* | |
3203 | * nr_running, nr_uninterruptible and nr_context_switches: | |
3204 | * | |
3205 | * externally visible scheduler statistics: current number of runnable | |
3206 | * threads, current number of uninterruptible-sleeping threads, total | |
3207 | * number of context switches performed since bootup. | |
3208 | */ | |
3209 | unsigned long nr_running(void) | |
3210 | { | |
3211 | unsigned long i, sum = 0; | |
3212 | ||
3213 | for_each_online_cpu(i) | |
3214 | sum += cpu_rq(i)->nr_running; | |
3215 | ||
3216 | return sum; | |
f711f609 | 3217 | } |
1da177e4 LT |
3218 | |
3219 | unsigned long nr_uninterruptible(void) | |
f711f609 | 3220 | { |
1da177e4 | 3221 | unsigned long i, sum = 0; |
f711f609 | 3222 | |
0a945022 | 3223 | for_each_possible_cpu(i) |
1da177e4 | 3224 | sum += cpu_rq(i)->nr_uninterruptible; |
f711f609 GS |
3225 | |
3226 | /* | |
1da177e4 LT |
3227 | * Since we read the counters lockless, it might be slightly |
3228 | * inaccurate. Do not allow it to go below zero though: | |
f711f609 | 3229 | */ |
1da177e4 LT |
3230 | if (unlikely((long)sum < 0)) |
3231 | sum = 0; | |
f711f609 | 3232 | |
1da177e4 | 3233 | return sum; |
f711f609 | 3234 | } |
f711f609 | 3235 | |
1da177e4 | 3236 | unsigned long long nr_context_switches(void) |
46cb4b7c | 3237 | { |
cc94abfc SR |
3238 | int i; |
3239 | unsigned long long sum = 0; | |
46cb4b7c | 3240 | |
0a945022 | 3241 | for_each_possible_cpu(i) |
1da177e4 | 3242 | sum += cpu_rq(i)->nr_switches; |
46cb4b7c | 3243 | |
1da177e4 LT |
3244 | return sum; |
3245 | } | |
483b4ee6 | 3246 | |
1da177e4 LT |
3247 | unsigned long nr_iowait(void) |
3248 | { | |
3249 | unsigned long i, sum = 0; | |
483b4ee6 | 3250 | |
0a945022 | 3251 | for_each_possible_cpu(i) |
1da177e4 | 3252 | sum += atomic_read(&cpu_rq(i)->nr_iowait); |
46cb4b7c | 3253 | |
1da177e4 LT |
3254 | return sum; |
3255 | } | |
483b4ee6 | 3256 | |
8c215bd3 | 3257 | unsigned long nr_iowait_cpu(int cpu) |
69d25870 | 3258 | { |
8c215bd3 | 3259 | struct rq *this = cpu_rq(cpu); |
69d25870 AV |
3260 | return atomic_read(&this->nr_iowait); |
3261 | } | |
46cb4b7c | 3262 | |
69d25870 AV |
3263 | unsigned long this_cpu_load(void) |
3264 | { | |
3265 | struct rq *this = this_rq(); | |
3266 | return this->cpu_load[0]; | |
3267 | } | |
e790fb0b | 3268 | |
46cb4b7c | 3269 | |
dce48a84 TG |
3270 | /* Variables and functions for calc_load */ |
3271 | static atomic_long_t calc_load_tasks; | |
3272 | static unsigned long calc_load_update; | |
3273 | unsigned long avenrun[3]; | |
3274 | EXPORT_SYMBOL(avenrun); | |
46cb4b7c | 3275 | |
74f5187a PZ |
3276 | static long calc_load_fold_active(struct rq *this_rq) |
3277 | { | |
3278 | long nr_active, delta = 0; | |
3279 | ||
3280 | nr_active = this_rq->nr_running; | |
3281 | nr_active += (long) this_rq->nr_uninterruptible; | |
3282 | ||
3283 | if (nr_active != this_rq->calc_load_active) { | |
3284 | delta = nr_active - this_rq->calc_load_active; | |
3285 | this_rq->calc_load_active = nr_active; | |
3286 | } | |
3287 | ||
3288 | return delta; | |
3289 | } | |
3290 | ||
0f004f5a PZ |
3291 | static unsigned long |
3292 | calc_load(unsigned long load, unsigned long exp, unsigned long active) | |
3293 | { | |
3294 | load *= exp; | |
3295 | load += active * (FIXED_1 - exp); | |
3296 | load += 1UL << (FSHIFT - 1); | |
3297 | return load >> FSHIFT; | |
3298 | } | |
3299 | ||
74f5187a PZ |
3300 | #ifdef CONFIG_NO_HZ |
3301 | /* | |
3302 | * For NO_HZ we delay the active fold to the next LOAD_FREQ update. | |
3303 | * | |
3304 | * When making the ILB scale, we should try to pull this in as well. | |
3305 | */ | |
3306 | static atomic_long_t calc_load_tasks_idle; | |
3307 | ||
3308 | static void calc_load_account_idle(struct rq *this_rq) | |
3309 | { | |
3310 | long delta; | |
3311 | ||
3312 | delta = calc_load_fold_active(this_rq); | |
3313 | if (delta) | |
3314 | atomic_long_add(delta, &calc_load_tasks_idle); | |
3315 | } | |
3316 | ||
3317 | static long calc_load_fold_idle(void) | |
3318 | { | |
3319 | long delta = 0; | |
3320 | ||
3321 | /* | |
3322 | * Its got a race, we don't care... | |
3323 | */ | |
3324 | if (atomic_long_read(&calc_load_tasks_idle)) | |
3325 | delta = atomic_long_xchg(&calc_load_tasks_idle, 0); | |
3326 | ||
3327 | return delta; | |
3328 | } | |
0f004f5a PZ |
3329 | |
3330 | /** | |
3331 | * fixed_power_int - compute: x^n, in O(log n) time | |
3332 | * | |
3333 | * @x: base of the power | |
3334 | * @frac_bits: fractional bits of @x | |
3335 | * @n: power to raise @x to. | |
3336 | * | |
3337 | * By exploiting the relation between the definition of the natural power | |
3338 | * function: x^n := x*x*...*x (x multiplied by itself for n times), and | |
3339 | * the binary encoding of numbers used by computers: n := \Sum n_i * 2^i, | |
3340 | * (where: n_i \elem {0, 1}, the binary vector representing n), | |
3341 | * we find: x^n := x^(\Sum n_i * 2^i) := \Prod x^(n_i * 2^i), which is | |
3342 | * of course trivially computable in O(log_2 n), the length of our binary | |
3343 | * vector. | |
3344 | */ | |
3345 | static unsigned long | |
3346 | fixed_power_int(unsigned long x, unsigned int frac_bits, unsigned int n) | |
3347 | { | |
3348 | unsigned long result = 1UL << frac_bits; | |
3349 | ||
3350 | if (n) for (;;) { | |
3351 | if (n & 1) { | |
3352 | result *= x; | |
3353 | result += 1UL << (frac_bits - 1); | |
3354 | result >>= frac_bits; | |
3355 | } | |
3356 | n >>= 1; | |
3357 | if (!n) | |
3358 | break; | |
3359 | x *= x; | |
3360 | x += 1UL << (frac_bits - 1); | |
3361 | x >>= frac_bits; | |
3362 | } | |
3363 | ||
3364 | return result; | |
3365 | } | |
3366 | ||
3367 | /* | |
3368 | * a1 = a0 * e + a * (1 - e) | |
3369 | * | |
3370 | * a2 = a1 * e + a * (1 - e) | |
3371 | * = (a0 * e + a * (1 - e)) * e + a * (1 - e) | |
3372 | * = a0 * e^2 + a * (1 - e) * (1 + e) | |
3373 | * | |
3374 | * a3 = a2 * e + a * (1 - e) | |
3375 | * = (a0 * e^2 + a * (1 - e) * (1 + e)) * e + a * (1 - e) | |
3376 | * = a0 * e^3 + a * (1 - e) * (1 + e + e^2) | |
3377 | * | |
3378 | * ... | |
3379 | * | |
3380 | * an = a0 * e^n + a * (1 - e) * (1 + e + ... + e^n-1) [1] | |
3381 | * = a0 * e^n + a * (1 - e) * (1 - e^n)/(1 - e) | |
3382 | * = a0 * e^n + a * (1 - e^n) | |
3383 | * | |
3384 | * [1] application of the geometric series: | |
3385 | * | |
3386 | * n 1 - x^(n+1) | |
3387 | * S_n := \Sum x^i = ------------- | |
3388 | * i=0 1 - x | |
3389 | */ | |
3390 | static unsigned long | |
3391 | calc_load_n(unsigned long load, unsigned long exp, | |
3392 | unsigned long active, unsigned int n) | |
3393 | { | |
3394 | ||
3395 | return calc_load(load, fixed_power_int(exp, FSHIFT, n), active); | |
3396 | } | |
3397 | ||
3398 | /* | |
3399 | * NO_HZ can leave us missing all per-cpu ticks calling | |
3400 | * calc_load_account_active(), but since an idle CPU folds its delta into | |
3401 | * calc_load_tasks_idle per calc_load_account_idle(), all we need to do is fold | |
3402 | * in the pending idle delta if our idle period crossed a load cycle boundary. | |
3403 | * | |
3404 | * Once we've updated the global active value, we need to apply the exponential | |
3405 | * weights adjusted to the number of cycles missed. | |
3406 | */ | |
3407 | static void calc_global_nohz(unsigned long ticks) | |
3408 | { | |
3409 | long delta, active, n; | |
3410 | ||
3411 | if (time_before(jiffies, calc_load_update)) | |
3412 | return; | |
3413 | ||
3414 | /* | |
3415 | * If we crossed a calc_load_update boundary, make sure to fold | |
3416 | * any pending idle changes, the respective CPUs might have | |
3417 | * missed the tick driven calc_load_account_active() update | |
3418 | * due to NO_HZ. | |
3419 | */ | |
3420 | delta = calc_load_fold_idle(); | |
3421 | if (delta) | |
3422 | atomic_long_add(delta, &calc_load_tasks); | |
3423 | ||
3424 | /* | |
3425 | * If we were idle for multiple load cycles, apply them. | |
3426 | */ | |
3427 | if (ticks >= LOAD_FREQ) { | |
3428 | n = ticks / LOAD_FREQ; | |
3429 | ||
3430 | active = atomic_long_read(&calc_load_tasks); | |
3431 | active = active > 0 ? active * FIXED_1 : 0; | |
3432 | ||
3433 | avenrun[0] = calc_load_n(avenrun[0], EXP_1, active, n); | |
3434 | avenrun[1] = calc_load_n(avenrun[1], EXP_5, active, n); | |
3435 | avenrun[2] = calc_load_n(avenrun[2], EXP_15, active, n); | |
3436 | ||
3437 | calc_load_update += n * LOAD_FREQ; | |
3438 | } | |
3439 | ||
3440 | /* | |
3441 | * Its possible the remainder of the above division also crosses | |
3442 | * a LOAD_FREQ period, the regular check in calc_global_load() | |
3443 | * which comes after this will take care of that. | |
3444 | * | |
3445 | * Consider us being 11 ticks before a cycle completion, and us | |
3446 | * sleeping for 4*LOAD_FREQ + 22 ticks, then the above code will | |
3447 | * age us 4 cycles, and the test in calc_global_load() will | |
3448 | * pick up the final one. | |
3449 | */ | |
3450 | } | |
74f5187a PZ |
3451 | #else |
3452 | static void calc_load_account_idle(struct rq *this_rq) | |
3453 | { | |
3454 | } | |
3455 | ||
3456 | static inline long calc_load_fold_idle(void) | |
3457 | { | |
3458 | return 0; | |
3459 | } | |
0f004f5a PZ |
3460 | |
3461 | static void calc_global_nohz(unsigned long ticks) | |
3462 | { | |
3463 | } | |
74f5187a PZ |
3464 | #endif |
3465 | ||
2d02494f TG |
3466 | /** |
3467 | * get_avenrun - get the load average array | |
3468 | * @loads: pointer to dest load array | |
3469 | * @offset: offset to add | |
3470 | * @shift: shift count to shift the result left | |
3471 | * | |
3472 | * These values are estimates at best, so no need for locking. | |
3473 | */ | |
3474 | void get_avenrun(unsigned long *loads, unsigned long offset, int shift) | |
3475 | { | |
3476 | loads[0] = (avenrun[0] + offset) << shift; | |
3477 | loads[1] = (avenrun[1] + offset) << shift; | |
3478 | loads[2] = (avenrun[2] + offset) << shift; | |
46cb4b7c | 3479 | } |
46cb4b7c | 3480 | |
46cb4b7c | 3481 | /* |
dce48a84 TG |
3482 | * calc_load - update the avenrun load estimates 10 ticks after the |
3483 | * CPUs have updated calc_load_tasks. | |
7835b98b | 3484 | */ |
0f004f5a | 3485 | void calc_global_load(unsigned long ticks) |
7835b98b | 3486 | { |
dce48a84 | 3487 | long active; |
1da177e4 | 3488 | |
0f004f5a PZ |
3489 | calc_global_nohz(ticks); |
3490 | ||
3491 | if (time_before(jiffies, calc_load_update + 10)) | |
dce48a84 | 3492 | return; |
1da177e4 | 3493 | |
dce48a84 TG |
3494 | active = atomic_long_read(&calc_load_tasks); |
3495 | active = active > 0 ? active * FIXED_1 : 0; | |
1da177e4 | 3496 | |
dce48a84 TG |
3497 | avenrun[0] = calc_load(avenrun[0], EXP_1, active); |
3498 | avenrun[1] = calc_load(avenrun[1], EXP_5, active); | |
3499 | avenrun[2] = calc_load(avenrun[2], EXP_15, active); | |
dd41f596 | 3500 | |
dce48a84 TG |
3501 | calc_load_update += LOAD_FREQ; |
3502 | } | |
1da177e4 | 3503 | |
dce48a84 | 3504 | /* |
74f5187a PZ |
3505 | * Called from update_cpu_load() to periodically update this CPU's |
3506 | * active count. | |
dce48a84 TG |
3507 | */ |
3508 | static void calc_load_account_active(struct rq *this_rq) | |
3509 | { | |
74f5187a | 3510 | long delta; |
08c183f3 | 3511 | |
74f5187a PZ |
3512 | if (time_before(jiffies, this_rq->calc_load_update)) |
3513 | return; | |
783609c6 | 3514 | |
74f5187a PZ |
3515 | delta = calc_load_fold_active(this_rq); |
3516 | delta += calc_load_fold_idle(); | |
3517 | if (delta) | |
dce48a84 | 3518 | atomic_long_add(delta, &calc_load_tasks); |
74f5187a PZ |
3519 | |
3520 | this_rq->calc_load_update += LOAD_FREQ; | |
46cb4b7c SS |
3521 | } |
3522 | ||
fdf3e95d VP |
3523 | /* |
3524 | * The exact cpuload at various idx values, calculated at every tick would be | |
3525 | * load = (2^idx - 1) / 2^idx * load + 1 / 2^idx * cur_load | |
3526 | * | |
3527 | * If a cpu misses updates for n-1 ticks (as it was idle) and update gets called | |
3528 | * on nth tick when cpu may be busy, then we have: | |
3529 | * load = ((2^idx - 1) / 2^idx)^(n-1) * load | |
3530 | * load = (2^idx - 1) / 2^idx) * load + 1 / 2^idx * cur_load | |
3531 | * | |
3532 | * decay_load_missed() below does efficient calculation of | |
3533 | * load = ((2^idx - 1) / 2^idx)^(n-1) * load | |
3534 | * avoiding 0..n-1 loop doing load = ((2^idx - 1) / 2^idx) * load | |
3535 | * | |
3536 | * The calculation is approximated on a 128 point scale. | |
3537 | * degrade_zero_ticks is the number of ticks after which load at any | |
3538 | * particular idx is approximated to be zero. | |
3539 | * degrade_factor is a precomputed table, a row for each load idx. | |
3540 | * Each column corresponds to degradation factor for a power of two ticks, | |
3541 | * based on 128 point scale. | |
3542 | * Example: | |
3543 | * row 2, col 3 (=12) says that the degradation at load idx 2 after | |
3544 | * 8 ticks is 12/128 (which is an approximation of exact factor 3^8/4^8). | |
3545 | * | |
3546 | * With this power of 2 load factors, we can degrade the load n times | |
3547 | * by looking at 1 bits in n and doing as many mult/shift instead of | |
3548 | * n mult/shifts needed by the exact degradation. | |
3549 | */ | |
3550 | #define DEGRADE_SHIFT 7 | |
3551 | static const unsigned char | |
3552 | degrade_zero_ticks[CPU_LOAD_IDX_MAX] = {0, 8, 32, 64, 128}; | |
3553 | static const unsigned char | |
3554 | degrade_factor[CPU_LOAD_IDX_MAX][DEGRADE_SHIFT + 1] = { | |
3555 | {0, 0, 0, 0, 0, 0, 0, 0}, | |
3556 | {64, 32, 8, 0, 0, 0, 0, 0}, | |
3557 | {96, 72, 40, 12, 1, 0, 0}, | |
3558 | {112, 98, 75, 43, 15, 1, 0}, | |
3559 | {120, 112, 98, 76, 45, 16, 2} }; | |
3560 | ||
3561 | /* | |
3562 | * Update cpu_load for any missed ticks, due to tickless idle. The backlog | |
3563 | * would be when CPU is idle and so we just decay the old load without | |
3564 | * adding any new load. | |
3565 | */ | |
3566 | static unsigned long | |
3567 | decay_load_missed(unsigned long load, unsigned long missed_updates, int idx) | |
3568 | { | |
3569 | int j = 0; | |
3570 | ||
3571 | if (!missed_updates) | |
3572 | return load; | |
3573 | ||
3574 | if (missed_updates >= degrade_zero_ticks[idx]) | |
3575 | return 0; | |
3576 | ||
3577 | if (idx == 1) | |
3578 | return load >> missed_updates; | |
3579 | ||
3580 | while (missed_updates) { | |
3581 | if (missed_updates % 2) | |
3582 | load = (load * degrade_factor[idx][j]) >> DEGRADE_SHIFT; | |
3583 | ||
3584 | missed_updates >>= 1; | |
3585 | j++; | |
3586 | } | |
3587 | return load; | |
3588 | } | |
3589 | ||
46cb4b7c | 3590 | /* |
dd41f596 | 3591 | * Update rq->cpu_load[] statistics. This function is usually called every |
fdf3e95d VP |
3592 | * scheduler tick (TICK_NSEC). With tickless idle this will not be called |
3593 | * every tick. We fix it up based on jiffies. | |
46cb4b7c | 3594 | */ |
dd41f596 | 3595 | static void update_cpu_load(struct rq *this_rq) |
46cb4b7c | 3596 | { |
495eca49 | 3597 | unsigned long this_load = this_rq->load.weight; |
fdf3e95d VP |
3598 | unsigned long curr_jiffies = jiffies; |
3599 | unsigned long pending_updates; | |
dd41f596 | 3600 | int i, scale; |
46cb4b7c | 3601 | |
dd41f596 | 3602 | this_rq->nr_load_updates++; |
46cb4b7c | 3603 | |
fdf3e95d VP |
3604 | /* Avoid repeated calls on same jiffy, when moving in and out of idle */ |
3605 | if (curr_jiffies == this_rq->last_load_update_tick) | |
3606 | return; | |
3607 | ||
3608 | pending_updates = curr_jiffies - this_rq->last_load_update_tick; | |
3609 | this_rq->last_load_update_tick = curr_jiffies; | |
3610 | ||
dd41f596 | 3611 | /* Update our load: */ |
fdf3e95d VP |
3612 | this_rq->cpu_load[0] = this_load; /* Fasttrack for idx 0 */ |
3613 | for (i = 1, scale = 2; i < CPU_LOAD_IDX_MAX; i++, scale += scale) { | |
dd41f596 | 3614 | unsigned long old_load, new_load; |
7d1e6a9b | 3615 | |
dd41f596 | 3616 | /* scale is effectively 1 << i now, and >> i divides by scale */ |
46cb4b7c | 3617 | |
dd41f596 | 3618 | old_load = this_rq->cpu_load[i]; |
fdf3e95d | 3619 | old_load = decay_load_missed(old_load, pending_updates - 1, i); |
dd41f596 | 3620 | new_load = this_load; |
a25707f3 IM |
3621 | /* |
3622 | * Round up the averaging division if load is increasing. This | |
3623 | * prevents us from getting stuck on 9 if the load is 10, for | |
3624 | * example. | |
3625 | */ | |
3626 | if (new_load > old_load) | |
fdf3e95d VP |
3627 | new_load += scale - 1; |
3628 | ||
3629 | this_rq->cpu_load[i] = (old_load * (scale - 1) + new_load) >> i; | |
dd41f596 | 3630 | } |
da2b71ed SS |
3631 | |
3632 | sched_avg_update(this_rq); | |
fdf3e95d VP |
3633 | } |
3634 | ||
3635 | static void update_cpu_load_active(struct rq *this_rq) | |
3636 | { | |
3637 | update_cpu_load(this_rq); | |
46cb4b7c | 3638 | |
74f5187a | 3639 | calc_load_account_active(this_rq); |
46cb4b7c SS |
3640 | } |
3641 | ||
dd41f596 | 3642 | #ifdef CONFIG_SMP |
8a0be9ef | 3643 | |
46cb4b7c | 3644 | /* |
38022906 PZ |
3645 | * sched_exec - execve() is a valuable balancing opportunity, because at |
3646 | * this point the task has the smallest effective memory and cache footprint. | |
46cb4b7c | 3647 | */ |
38022906 | 3648 | void sched_exec(void) |
46cb4b7c | 3649 | { |
38022906 | 3650 | struct task_struct *p = current; |
1da177e4 | 3651 | unsigned long flags; |
0017d735 | 3652 | int dest_cpu; |
46cb4b7c | 3653 | |
8f42ced9 | 3654 | raw_spin_lock_irqsave(&p->pi_lock, flags); |
7608dec2 | 3655 | dest_cpu = p->sched_class->select_task_rq(p, SD_BALANCE_EXEC, 0); |
0017d735 PZ |
3656 | if (dest_cpu == smp_processor_id()) |
3657 | goto unlock; | |
38022906 | 3658 | |
8f42ced9 | 3659 | if (likely(cpu_active(dest_cpu))) { |
969c7921 | 3660 | struct migration_arg arg = { p, dest_cpu }; |
46cb4b7c | 3661 | |
8f42ced9 PZ |
3662 | raw_spin_unlock_irqrestore(&p->pi_lock, flags); |
3663 | stop_one_cpu(task_cpu(p), migration_cpu_stop, &arg); | |
1da177e4 LT |
3664 | return; |
3665 | } | |
0017d735 | 3666 | unlock: |
8f42ced9 | 3667 | raw_spin_unlock_irqrestore(&p->pi_lock, flags); |
1da177e4 | 3668 | } |
dd41f596 | 3669 | |
1da177e4 LT |
3670 | #endif |
3671 | ||
1da177e4 LT |
3672 | DEFINE_PER_CPU(struct kernel_stat, kstat); |
3673 | ||
3674 | EXPORT_PER_CPU_SYMBOL(kstat); | |
3675 | ||
3676 | /* | |
c5f8d995 | 3677 | * Return any ns on the sched_clock that have not yet been accounted in |
f06febc9 | 3678 | * @p in case that task is currently running. |
c5f8d995 HS |
3679 | * |
3680 | * Called with task_rq_lock() held on @rq. | |
1da177e4 | 3681 | */ |
c5f8d995 HS |
3682 | static u64 do_task_delta_exec(struct task_struct *p, struct rq *rq) |
3683 | { | |
3684 | u64 ns = 0; | |
3685 | ||
3686 | if (task_current(rq, p)) { | |
3687 | update_rq_clock(rq); | |
305e6835 | 3688 | ns = rq->clock_task - p->se.exec_start; |
c5f8d995 HS |
3689 | if ((s64)ns < 0) |
3690 | ns = 0; | |
3691 | } | |
3692 | ||
3693 | return ns; | |
3694 | } | |
3695 | ||
bb34d92f | 3696 | unsigned long long task_delta_exec(struct task_struct *p) |
1da177e4 | 3697 | { |
1da177e4 | 3698 | unsigned long flags; |
41b86e9c | 3699 | struct rq *rq; |
bb34d92f | 3700 | u64 ns = 0; |
48f24c4d | 3701 | |
41b86e9c | 3702 | rq = task_rq_lock(p, &flags); |
c5f8d995 | 3703 | ns = do_task_delta_exec(p, rq); |
0122ec5b | 3704 | task_rq_unlock(rq, p, &flags); |
1508487e | 3705 | |
c5f8d995 HS |
3706 | return ns; |
3707 | } | |
f06febc9 | 3708 | |
c5f8d995 HS |
3709 | /* |
3710 | * Return accounted runtime for the task. | |
3711 | * In case the task is currently running, return the runtime plus current's | |
3712 | * pending runtime that have not been accounted yet. | |
3713 | */ | |
3714 | unsigned long long task_sched_runtime(struct task_struct *p) | |
3715 | { | |
3716 | unsigned long flags; | |
3717 | struct rq *rq; | |
3718 | u64 ns = 0; | |
3719 | ||
3720 | rq = task_rq_lock(p, &flags); | |
3721 | ns = p->se.sum_exec_runtime + do_task_delta_exec(p, rq); | |
0122ec5b | 3722 | task_rq_unlock(rq, p, &flags); |
c5f8d995 HS |
3723 | |
3724 | return ns; | |
3725 | } | |
48f24c4d | 3726 | |
c5f8d995 HS |
3727 | /* |
3728 | * Return sum_exec_runtime for the thread group. | |
3729 | * In case the task is currently running, return the sum plus current's | |
3730 | * pending runtime that have not been accounted yet. | |
3731 | * | |
3732 | * Note that the thread group might have other running tasks as well, | |
3733 | * so the return value not includes other pending runtime that other | |
3734 | * running tasks might have. | |
3735 | */ | |
3736 | unsigned long long thread_group_sched_runtime(struct task_struct *p) | |
3737 | { | |
3738 | struct task_cputime totals; | |
3739 | unsigned long flags; | |
3740 | struct rq *rq; | |
3741 | u64 ns; | |
3742 | ||
3743 | rq = task_rq_lock(p, &flags); | |
3744 | thread_group_cputime(p, &totals); | |
3745 | ns = totals.sum_exec_runtime + do_task_delta_exec(p, rq); | |
0122ec5b | 3746 | task_rq_unlock(rq, p, &flags); |
48f24c4d | 3747 | |
1da177e4 LT |
3748 | return ns; |
3749 | } | |
3750 | ||
1da177e4 LT |
3751 | /* |
3752 | * Account user cpu time to a process. | |
3753 | * @p: the process that the cpu time gets accounted to | |
1da177e4 | 3754 | * @cputime: the cpu time spent in user space since the last update |
457533a7 | 3755 | * @cputime_scaled: cputime scaled by cpu frequency |
1da177e4 | 3756 | */ |
457533a7 MS |
3757 | void account_user_time(struct task_struct *p, cputime_t cputime, |
3758 | cputime_t cputime_scaled) | |
1da177e4 LT |
3759 | { |
3760 | struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat; | |
3761 | cputime64_t tmp; | |
3762 | ||
457533a7 | 3763 | /* Add user time to process. */ |
1da177e4 | 3764 | p->utime = cputime_add(p->utime, cputime); |
457533a7 | 3765 | p->utimescaled = cputime_add(p->utimescaled, cputime_scaled); |
f06febc9 | 3766 | account_group_user_time(p, cputime); |
1da177e4 LT |
3767 | |
3768 | /* Add user time to cpustat. */ | |
3769 | tmp = cputime_to_cputime64(cputime); | |
3770 | if (TASK_NICE(p) > 0) | |
3771 | cpustat->nice = cputime64_add(cpustat->nice, tmp); | |
3772 | else | |
3773 | cpustat->user = cputime64_add(cpustat->user, tmp); | |
ef12fefa BR |
3774 | |
3775 | cpuacct_update_stats(p, CPUACCT_STAT_USER, cputime); | |
49b5cf34 JL |
3776 | /* Account for user time used */ |
3777 | acct_update_integrals(p); | |
1da177e4 LT |
3778 | } |
3779 | ||
94886b84 LV |
3780 | /* |
3781 | * Account guest cpu time to a process. | |
3782 | * @p: the process that the cpu time gets accounted to | |
3783 | * @cputime: the cpu time spent in virtual machine since the last update | |
457533a7 | 3784 | * @cputime_scaled: cputime scaled by cpu frequency |
94886b84 | 3785 | */ |
457533a7 MS |
3786 | static void account_guest_time(struct task_struct *p, cputime_t cputime, |
3787 | cputime_t cputime_scaled) | |
94886b84 LV |
3788 | { |
3789 | cputime64_t tmp; | |
3790 | struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat; | |
3791 | ||
3792 | tmp = cputime_to_cputime64(cputime); | |
3793 | ||
457533a7 | 3794 | /* Add guest time to process. */ |
94886b84 | 3795 | p->utime = cputime_add(p->utime, cputime); |
457533a7 | 3796 | p->utimescaled = cputime_add(p->utimescaled, cputime_scaled); |
f06febc9 | 3797 | account_group_user_time(p, cputime); |
94886b84 LV |
3798 | p->gtime = cputime_add(p->gtime, cputime); |
3799 | ||
457533a7 | 3800 | /* Add guest time to cpustat. */ |
ce0e7b28 RO |
3801 | if (TASK_NICE(p) > 0) { |
3802 | cpustat->nice = cputime64_add(cpustat->nice, tmp); | |
3803 | cpustat->guest_nice = cputime64_add(cpustat->guest_nice, tmp); | |
3804 | } else { | |
3805 | cpustat->user = cputime64_add(cpustat->user, tmp); | |
3806 | cpustat->guest = cputime64_add(cpustat->guest, tmp); | |
3807 | } | |
94886b84 LV |
3808 | } |
3809 | ||
70a89a66 VP |
3810 | /* |
3811 | * Account system cpu time to a process and desired cpustat field | |
3812 | * @p: the process that the cpu time gets accounted to | |
3813 | * @cputime: the cpu time spent in kernel space since the last update | |
3814 | * @cputime_scaled: cputime scaled by cpu frequency | |
3815 | * @target_cputime64: pointer to cpustat field that has to be updated | |
3816 | */ | |
3817 | static inline | |
3818 | void __account_system_time(struct task_struct *p, cputime_t cputime, | |
3819 | cputime_t cputime_scaled, cputime64_t *target_cputime64) | |
3820 | { | |
3821 | cputime64_t tmp = cputime_to_cputime64(cputime); | |
3822 | ||
3823 | /* Add system time to process. */ | |
3824 | p->stime = cputime_add(p->stime, cputime); | |
3825 | p->stimescaled = cputime_add(p->stimescaled, cputime_scaled); | |
3826 | account_group_system_time(p, cputime); | |
3827 | ||
3828 | /* Add system time to cpustat. */ | |
3829 | *target_cputime64 = cputime64_add(*target_cputime64, tmp); | |
3830 | cpuacct_update_stats(p, CPUACCT_STAT_SYSTEM, cputime); | |
3831 | ||
3832 | /* Account for system time used */ | |
3833 | acct_update_integrals(p); | |
3834 | } | |
3835 | ||
1da177e4 LT |
3836 | /* |
3837 | * Account system cpu time to a process. | |
3838 | * @p: the process that the cpu time gets accounted to | |
3839 | * @hardirq_offset: the offset to subtract from hardirq_count() | |
3840 | * @cputime: the cpu time spent in kernel space since the last update | |
457533a7 | 3841 | * @cputime_scaled: cputime scaled by cpu frequency |
1da177e4 LT |
3842 | */ |
3843 | void account_system_time(struct task_struct *p, int hardirq_offset, | |
457533a7 | 3844 | cputime_t cputime, cputime_t cputime_scaled) |
1da177e4 LT |
3845 | { |
3846 | struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat; | |
70a89a66 | 3847 | cputime64_t *target_cputime64; |
1da177e4 | 3848 | |
983ed7a6 | 3849 | if ((p->flags & PF_VCPU) && (irq_count() - hardirq_offset == 0)) { |
457533a7 | 3850 | account_guest_time(p, cputime, cputime_scaled); |
983ed7a6 HH |
3851 | return; |
3852 | } | |
94886b84 | 3853 | |
1da177e4 | 3854 | if (hardirq_count() - hardirq_offset) |
70a89a66 | 3855 | target_cputime64 = &cpustat->irq; |
75e1056f | 3856 | else if (in_serving_softirq()) |
70a89a66 | 3857 | target_cputime64 = &cpustat->softirq; |
1da177e4 | 3858 | else |
70a89a66 | 3859 | target_cputime64 = &cpustat->system; |
ef12fefa | 3860 | |
70a89a66 | 3861 | __account_system_time(p, cputime, cputime_scaled, target_cputime64); |
1da177e4 LT |
3862 | } |
3863 | ||
c66f08be | 3864 | /* |
1da177e4 | 3865 | * Account for involuntary wait time. |
544b4a1f | 3866 | * @cputime: the cpu time spent in involuntary wait |
c66f08be | 3867 | */ |
79741dd3 | 3868 | void account_steal_time(cputime_t cputime) |
c66f08be | 3869 | { |
79741dd3 MS |
3870 | struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat; |
3871 | cputime64_t cputime64 = cputime_to_cputime64(cputime); | |
3872 | ||
3873 | cpustat->steal = cputime64_add(cpustat->steal, cputime64); | |
c66f08be MN |
3874 | } |
3875 | ||
1da177e4 | 3876 | /* |
79741dd3 MS |
3877 | * Account for idle time. |
3878 | * @cputime: the cpu time spent in idle wait | |
1da177e4 | 3879 | */ |
79741dd3 | 3880 | void account_idle_time(cputime_t cputime) |
1da177e4 LT |
3881 | { |
3882 | struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat; | |
79741dd3 | 3883 | cputime64_t cputime64 = cputime_to_cputime64(cputime); |
70b97a7f | 3884 | struct rq *rq = this_rq(); |
1da177e4 | 3885 | |
79741dd3 MS |
3886 | if (atomic_read(&rq->nr_iowait) > 0) |
3887 | cpustat->iowait = cputime64_add(cpustat->iowait, cputime64); | |
3888 | else | |
3889 | cpustat->idle = cputime64_add(cpustat->idle, cputime64); | |
1da177e4 LT |
3890 | } |
3891 | ||
e6e6685a GC |
3892 | static __always_inline bool steal_account_process_tick(void) |
3893 | { | |
3894 | #ifdef CONFIG_PARAVIRT | |
3895 | if (static_branch(¶virt_steal_enabled)) { | |
3896 | u64 steal, st = 0; | |
3897 | ||
3898 | steal = paravirt_steal_clock(smp_processor_id()); | |
3899 | steal -= this_rq()->prev_steal_time; | |
3900 | ||
3901 | st = steal_ticks(steal); | |
3902 | this_rq()->prev_steal_time += st * TICK_NSEC; | |
3903 | ||
3904 | account_steal_time(st); | |
3905 | return st; | |
3906 | } | |
3907 | #endif | |
3908 | return false; | |
3909 | } | |
3910 | ||
79741dd3 MS |
3911 | #ifndef CONFIG_VIRT_CPU_ACCOUNTING |
3912 | ||
abb74cef VP |
3913 | #ifdef CONFIG_IRQ_TIME_ACCOUNTING |
3914 | /* | |
3915 | * Account a tick to a process and cpustat | |
3916 | * @p: the process that the cpu time gets accounted to | |
3917 | * @user_tick: is the tick from userspace | |
3918 | * @rq: the pointer to rq | |
3919 | * | |
3920 | * Tick demultiplexing follows the order | |
3921 | * - pending hardirq update | |
3922 | * - pending softirq update | |
3923 | * - user_time | |
3924 | * - idle_time | |
3925 | * - system time | |
3926 | * - check for guest_time | |
3927 | * - else account as system_time | |
3928 | * | |
3929 | * Check for hardirq is done both for system and user time as there is | |
3930 | * no timer going off while we are on hardirq and hence we may never get an | |
3931 | * opportunity to update it solely in system time. | |
3932 | * p->stime and friends are only updated on system time and not on irq | |
3933 | * softirq as those do not count in task exec_runtime any more. | |
3934 | */ | |
3935 | static void irqtime_account_process_tick(struct task_struct *p, int user_tick, | |
3936 | struct rq *rq) | |
3937 | { | |
3938 | cputime_t one_jiffy_scaled = cputime_to_scaled(cputime_one_jiffy); | |
3939 | cputime64_t tmp = cputime_to_cputime64(cputime_one_jiffy); | |
3940 | struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat; | |
3941 | ||
e6e6685a GC |
3942 | if (steal_account_process_tick()) |
3943 | return; | |
3944 | ||
abb74cef VP |
3945 | if (irqtime_account_hi_update()) { |
3946 | cpustat->irq = cputime64_add(cpustat->irq, tmp); | |
3947 | } else if (irqtime_account_si_update()) { | |
3948 | cpustat->softirq = cputime64_add(cpustat->softirq, tmp); | |
414bee9b VP |
3949 | } else if (this_cpu_ksoftirqd() == p) { |
3950 | /* | |
3951 | * ksoftirqd time do not get accounted in cpu_softirq_time. | |
3952 | * So, we have to handle it separately here. | |
3953 | * Also, p->stime needs to be updated for ksoftirqd. | |
3954 | */ | |
3955 | __account_system_time(p, cputime_one_jiffy, one_jiffy_scaled, | |
3956 | &cpustat->softirq); | |
abb74cef VP |
3957 | } else if (user_tick) { |
3958 | account_user_time(p, cputime_one_jiffy, one_jiffy_scaled); | |
3959 | } else if (p == rq->idle) { | |
3960 | account_idle_time(cputime_one_jiffy); | |
3961 | } else if (p->flags & PF_VCPU) { /* System time or guest time */ | |
3962 | account_guest_time(p, cputime_one_jiffy, one_jiffy_scaled); | |
3963 | } else { | |
3964 | __account_system_time(p, cputime_one_jiffy, one_jiffy_scaled, | |
3965 | &cpustat->system); | |
3966 | } | |
3967 | } | |
3968 | ||
3969 | static void irqtime_account_idle_ticks(int ticks) | |
3970 | { | |
3971 | int i; | |
3972 | struct rq *rq = this_rq(); | |
3973 | ||
3974 | for (i = 0; i < ticks; i++) | |
3975 | irqtime_account_process_tick(current, 0, rq); | |
3976 | } | |
544b4a1f | 3977 | #else /* CONFIG_IRQ_TIME_ACCOUNTING */ |
abb74cef VP |
3978 | static void irqtime_account_idle_ticks(int ticks) {} |
3979 | static void irqtime_account_process_tick(struct task_struct *p, int user_tick, | |
3980 | struct rq *rq) {} | |
544b4a1f | 3981 | #endif /* CONFIG_IRQ_TIME_ACCOUNTING */ |
79741dd3 MS |
3982 | |
3983 | /* | |
3984 | * Account a single tick of cpu time. | |
3985 | * @p: the process that the cpu time gets accounted to | |
3986 | * @user_tick: indicates if the tick is a user or a system tick | |
3987 | */ | |
3988 | void account_process_tick(struct task_struct *p, int user_tick) | |
3989 | { | |
a42548a1 | 3990 | cputime_t one_jiffy_scaled = cputime_to_scaled(cputime_one_jiffy); |
79741dd3 MS |
3991 | struct rq *rq = this_rq(); |
3992 | ||
abb74cef VP |
3993 | if (sched_clock_irqtime) { |
3994 | irqtime_account_process_tick(p, user_tick, rq); | |
3995 | return; | |
3996 | } | |
3997 | ||
e6e6685a GC |
3998 | if (steal_account_process_tick()) |
3999 | return; | |
4000 | ||
79741dd3 | 4001 | if (user_tick) |
a42548a1 | 4002 | account_user_time(p, cputime_one_jiffy, one_jiffy_scaled); |
f5f293a4 | 4003 | else if ((p != rq->idle) || (irq_count() != HARDIRQ_OFFSET)) |
a42548a1 | 4004 | account_system_time(p, HARDIRQ_OFFSET, cputime_one_jiffy, |
79741dd3 MS |
4005 | one_jiffy_scaled); |
4006 | else | |
a42548a1 | 4007 | account_idle_time(cputime_one_jiffy); |
79741dd3 MS |
4008 | } |
4009 | ||
4010 | /* | |
4011 | * Account multiple ticks of steal time. | |
4012 | * @p: the process from which the cpu time has been stolen | |
4013 | * @ticks: number of stolen ticks | |
4014 | */ | |
4015 | void account_steal_ticks(unsigned long ticks) | |
4016 | { | |
4017 | account_steal_time(jiffies_to_cputime(ticks)); | |
4018 | } | |
4019 | ||
4020 | /* | |
4021 | * Account multiple ticks of idle time. | |
4022 | * @ticks: number of stolen ticks | |
4023 | */ | |
4024 | void account_idle_ticks(unsigned long ticks) | |
4025 | { | |
abb74cef VP |
4026 | |
4027 | if (sched_clock_irqtime) { | |
4028 | irqtime_account_idle_ticks(ticks); | |
4029 | return; | |
4030 | } | |
4031 | ||
79741dd3 | 4032 | account_idle_time(jiffies_to_cputime(ticks)); |
1da177e4 LT |
4033 | } |
4034 | ||
79741dd3 MS |
4035 | #endif |
4036 | ||
49048622 BS |
4037 | /* |
4038 | * Use precise platform statistics if available: | |
4039 | */ | |
4040 | #ifdef CONFIG_VIRT_CPU_ACCOUNTING | |
d180c5bc | 4041 | void task_times(struct task_struct *p, cputime_t *ut, cputime_t *st) |
49048622 | 4042 | { |
d99ca3b9 HS |
4043 | *ut = p->utime; |
4044 | *st = p->stime; | |
49048622 BS |
4045 | } |
4046 | ||
0cf55e1e | 4047 | void thread_group_times(struct task_struct *p, cputime_t *ut, cputime_t *st) |
49048622 | 4048 | { |
0cf55e1e HS |
4049 | struct task_cputime cputime; |
4050 | ||
4051 | thread_group_cputime(p, &cputime); | |
4052 | ||
4053 | *ut = cputime.utime; | |
4054 | *st = cputime.stime; | |
49048622 BS |
4055 | } |
4056 | #else | |
761b1d26 HS |
4057 | |
4058 | #ifndef nsecs_to_cputime | |
b7b20df9 | 4059 | # define nsecs_to_cputime(__nsecs) nsecs_to_jiffies(__nsecs) |
761b1d26 HS |
4060 | #endif |
4061 | ||
d180c5bc | 4062 | void task_times(struct task_struct *p, cputime_t *ut, cputime_t *st) |
49048622 | 4063 | { |
d99ca3b9 | 4064 | cputime_t rtime, utime = p->utime, total = cputime_add(utime, p->stime); |
49048622 BS |
4065 | |
4066 | /* | |
4067 | * Use CFS's precise accounting: | |
4068 | */ | |
d180c5bc | 4069 | rtime = nsecs_to_cputime(p->se.sum_exec_runtime); |
49048622 BS |
4070 | |
4071 | if (total) { | |
e75e863d | 4072 | u64 temp = rtime; |
d180c5bc | 4073 | |
e75e863d | 4074 | temp *= utime; |
49048622 | 4075 | do_div(temp, total); |
d180c5bc HS |
4076 | utime = (cputime_t)temp; |
4077 | } else | |
4078 | utime = rtime; | |
49048622 | 4079 | |
d180c5bc HS |
4080 | /* |
4081 | * Compare with previous values, to keep monotonicity: | |
4082 | */ | |
761b1d26 | 4083 | p->prev_utime = max(p->prev_utime, utime); |
d99ca3b9 | 4084 | p->prev_stime = max(p->prev_stime, cputime_sub(rtime, p->prev_utime)); |
49048622 | 4085 | |
d99ca3b9 HS |
4086 | *ut = p->prev_utime; |
4087 | *st = p->prev_stime; | |
49048622 BS |
4088 | } |
4089 | ||
0cf55e1e HS |
4090 | /* |
4091 | * Must be called with siglock held. | |
4092 | */ | |
4093 | void thread_group_times(struct task_struct *p, cputime_t *ut, cputime_t *st) | |
49048622 | 4094 | { |
0cf55e1e HS |
4095 | struct signal_struct *sig = p->signal; |
4096 | struct task_cputime cputime; | |
4097 | cputime_t rtime, utime, total; | |
49048622 | 4098 | |
0cf55e1e | 4099 | thread_group_cputime(p, &cputime); |
49048622 | 4100 | |
0cf55e1e HS |
4101 | total = cputime_add(cputime.utime, cputime.stime); |
4102 | rtime = nsecs_to_cputime(cputime.sum_exec_runtime); | |
49048622 | 4103 | |
0cf55e1e | 4104 | if (total) { |
e75e863d | 4105 | u64 temp = rtime; |
49048622 | 4106 | |
e75e863d | 4107 | temp *= cputime.utime; |
0cf55e1e HS |
4108 | do_div(temp, total); |
4109 | utime = (cputime_t)temp; | |
4110 | } else | |
4111 | utime = rtime; | |
4112 | ||
4113 | sig->prev_utime = max(sig->prev_utime, utime); | |
4114 | sig->prev_stime = max(sig->prev_stime, | |
4115 | cputime_sub(rtime, sig->prev_utime)); | |
4116 | ||
4117 | *ut = sig->prev_utime; | |
4118 | *st = sig->prev_stime; | |
49048622 | 4119 | } |
49048622 | 4120 | #endif |
49048622 | 4121 | |
7835b98b CL |
4122 | /* |
4123 | * This function gets called by the timer code, with HZ frequency. | |
4124 | * We call it with interrupts disabled. | |
7835b98b CL |
4125 | */ |
4126 | void scheduler_tick(void) | |
4127 | { | |
7835b98b CL |
4128 | int cpu = smp_processor_id(); |
4129 | struct rq *rq = cpu_rq(cpu); | |
dd41f596 | 4130 | struct task_struct *curr = rq->curr; |
3e51f33f PZ |
4131 | |
4132 | sched_clock_tick(); | |
dd41f596 | 4133 | |
05fa785c | 4134 | raw_spin_lock(&rq->lock); |
3e51f33f | 4135 | update_rq_clock(rq); |
fdf3e95d | 4136 | update_cpu_load_active(rq); |
fa85ae24 | 4137 | curr->sched_class->task_tick(rq, curr, 0); |
05fa785c | 4138 | raw_spin_unlock(&rq->lock); |
7835b98b | 4139 | |
e9d2b064 | 4140 | perf_event_task_tick(); |
e220d2dc | 4141 | |
e418e1c2 | 4142 | #ifdef CONFIG_SMP |
dd41f596 IM |
4143 | rq->idle_at_tick = idle_cpu(cpu); |
4144 | trigger_load_balance(rq, cpu); | |
e418e1c2 | 4145 | #endif |
1da177e4 LT |
4146 | } |
4147 | ||
132380a0 | 4148 | notrace unsigned long get_parent_ip(unsigned long addr) |
6cd8a4bb SR |
4149 | { |
4150 | if (in_lock_functions(addr)) { | |
4151 | addr = CALLER_ADDR2; | |
4152 | if (in_lock_functions(addr)) | |
4153 | addr = CALLER_ADDR3; | |
4154 | } | |
4155 | return addr; | |
4156 | } | |
1da177e4 | 4157 | |
7e49fcce SR |
4158 | #if defined(CONFIG_PREEMPT) && (defined(CONFIG_DEBUG_PREEMPT) || \ |
4159 | defined(CONFIG_PREEMPT_TRACER)) | |
4160 | ||
43627582 | 4161 | void __kprobes add_preempt_count(int val) |
1da177e4 | 4162 | { |
6cd8a4bb | 4163 | #ifdef CONFIG_DEBUG_PREEMPT |
1da177e4 LT |
4164 | /* |
4165 | * Underflow? | |
4166 | */ | |
9a11b49a IM |
4167 | if (DEBUG_LOCKS_WARN_ON((preempt_count() < 0))) |
4168 | return; | |
6cd8a4bb | 4169 | #endif |
1da177e4 | 4170 | preempt_count() += val; |
6cd8a4bb | 4171 | #ifdef CONFIG_DEBUG_PREEMPT |
1da177e4 LT |
4172 | /* |
4173 | * Spinlock count overflowing soon? | |
4174 | */ | |
33859f7f MOS |
4175 | DEBUG_LOCKS_WARN_ON((preempt_count() & PREEMPT_MASK) >= |
4176 | PREEMPT_MASK - 10); | |
6cd8a4bb SR |
4177 | #endif |
4178 | if (preempt_count() == val) | |
4179 | trace_preempt_off(CALLER_ADDR0, get_parent_ip(CALLER_ADDR1)); | |
1da177e4 LT |
4180 | } |
4181 | EXPORT_SYMBOL(add_preempt_count); | |
4182 | ||
43627582 | 4183 | void __kprobes sub_preempt_count(int val) |
1da177e4 | 4184 | { |
6cd8a4bb | 4185 | #ifdef CONFIG_DEBUG_PREEMPT |
1da177e4 LT |
4186 | /* |
4187 | * Underflow? | |
4188 | */ | |
01e3eb82 | 4189 | if (DEBUG_LOCKS_WARN_ON(val > preempt_count())) |
9a11b49a | 4190 | return; |
1da177e4 LT |
4191 | /* |
4192 | * Is the spinlock portion underflowing? | |
4193 | */ | |
9a11b49a IM |
4194 | if (DEBUG_LOCKS_WARN_ON((val < PREEMPT_MASK) && |
4195 | !(preempt_count() & PREEMPT_MASK))) | |
4196 | return; | |
6cd8a4bb | 4197 | #endif |
9a11b49a | 4198 | |
6cd8a4bb SR |
4199 | if (preempt_count() == val) |
4200 | trace_preempt_on(CALLER_ADDR0, get_parent_ip(CALLER_ADDR1)); | |
1da177e4 LT |
4201 | preempt_count() -= val; |
4202 | } | |
4203 | EXPORT_SYMBOL(sub_preempt_count); | |
4204 | ||
4205 | #endif | |
4206 | ||
4207 | /* | |
dd41f596 | 4208 | * Print scheduling while atomic bug: |
1da177e4 | 4209 | */ |
dd41f596 | 4210 | static noinline void __schedule_bug(struct task_struct *prev) |
1da177e4 | 4211 | { |
838225b4 SS |
4212 | struct pt_regs *regs = get_irq_regs(); |
4213 | ||
3df0fc5b PZ |
4214 | printk(KERN_ERR "BUG: scheduling while atomic: %s/%d/0x%08x\n", |
4215 | prev->comm, prev->pid, preempt_count()); | |
838225b4 | 4216 | |
dd41f596 | 4217 | debug_show_held_locks(prev); |
e21f5b15 | 4218 | print_modules(); |
dd41f596 IM |
4219 | if (irqs_disabled()) |
4220 | print_irqtrace_events(prev); | |
838225b4 SS |
4221 | |
4222 | if (regs) | |
4223 | show_regs(regs); | |
4224 | else | |
4225 | dump_stack(); | |
dd41f596 | 4226 | } |
1da177e4 | 4227 | |
dd41f596 IM |
4228 | /* |
4229 | * Various schedule()-time debugging checks and statistics: | |
4230 | */ | |
4231 | static inline void schedule_debug(struct task_struct *prev) | |
4232 | { | |
1da177e4 | 4233 | /* |
41a2d6cf | 4234 | * Test if we are atomic. Since do_exit() needs to call into |
1da177e4 LT |
4235 | * schedule() atomically, we ignore that path for now. |
4236 | * Otherwise, whine if we are scheduling when we should not be. | |
4237 | */ | |
3f33a7ce | 4238 | if (unlikely(in_atomic_preempt_off() && !prev->exit_state)) |
dd41f596 IM |
4239 | __schedule_bug(prev); |
4240 | ||
1da177e4 LT |
4241 | profile_hit(SCHED_PROFILING, __builtin_return_address(0)); |
4242 | ||
2d72376b | 4243 | schedstat_inc(this_rq(), sched_count); |
dd41f596 IM |
4244 | } |
4245 | ||
6cecd084 | 4246 | static void put_prev_task(struct rq *rq, struct task_struct *prev) |
df1c99d4 | 4247 | { |
61eadef6 | 4248 | if (prev->on_rq || rq->skip_clock_update < 0) |
a64692a3 | 4249 | update_rq_clock(rq); |
6cecd084 | 4250 | prev->sched_class->put_prev_task(rq, prev); |
df1c99d4 MG |
4251 | } |
4252 | ||
dd41f596 IM |
4253 | /* |
4254 | * Pick up the highest-prio task: | |
4255 | */ | |
4256 | static inline struct task_struct * | |
b67802ea | 4257 | pick_next_task(struct rq *rq) |
dd41f596 | 4258 | { |
5522d5d5 | 4259 | const struct sched_class *class; |
dd41f596 | 4260 | struct task_struct *p; |
1da177e4 LT |
4261 | |
4262 | /* | |
dd41f596 IM |
4263 | * Optimization: we know that if all tasks are in |
4264 | * the fair class we can call that function directly: | |
1da177e4 | 4265 | */ |
dd41f596 | 4266 | if (likely(rq->nr_running == rq->cfs.nr_running)) { |
fb8d4724 | 4267 | p = fair_sched_class.pick_next_task(rq); |
dd41f596 IM |
4268 | if (likely(p)) |
4269 | return p; | |
1da177e4 LT |
4270 | } |
4271 | ||
34f971f6 | 4272 | for_each_class(class) { |
fb8d4724 | 4273 | p = class->pick_next_task(rq); |
dd41f596 IM |
4274 | if (p) |
4275 | return p; | |
dd41f596 | 4276 | } |
34f971f6 PZ |
4277 | |
4278 | BUG(); /* the idle class will always have a runnable task */ | |
dd41f596 | 4279 | } |
1da177e4 | 4280 | |
dd41f596 IM |
4281 | /* |
4282 | * schedule() is the main scheduler function. | |
4283 | */ | |
ff743345 | 4284 | asmlinkage void __sched schedule(void) |
dd41f596 IM |
4285 | { |
4286 | struct task_struct *prev, *next; | |
67ca7bde | 4287 | unsigned long *switch_count; |
dd41f596 | 4288 | struct rq *rq; |
31656519 | 4289 | int cpu; |
dd41f596 | 4290 | |
ff743345 PZ |
4291 | need_resched: |
4292 | preempt_disable(); | |
dd41f596 IM |
4293 | cpu = smp_processor_id(); |
4294 | rq = cpu_rq(cpu); | |
25502a6c | 4295 | rcu_note_context_switch(cpu); |
dd41f596 | 4296 | prev = rq->curr; |
dd41f596 | 4297 | |
dd41f596 | 4298 | schedule_debug(prev); |
1da177e4 | 4299 | |
31656519 | 4300 | if (sched_feat(HRTICK)) |
f333fdc9 | 4301 | hrtick_clear(rq); |
8f4d37ec | 4302 | |
05fa785c | 4303 | raw_spin_lock_irq(&rq->lock); |
1da177e4 | 4304 | |
246d86b5 | 4305 | switch_count = &prev->nivcsw; |
1da177e4 | 4306 | if (prev->state && !(preempt_count() & PREEMPT_ACTIVE)) { |
21aa9af0 | 4307 | if (unlikely(signal_pending_state(prev->state, prev))) { |
1da177e4 | 4308 | prev->state = TASK_RUNNING; |
21aa9af0 | 4309 | } else { |
2acca55e PZ |
4310 | deactivate_task(rq, prev, DEQUEUE_SLEEP); |
4311 | prev->on_rq = 0; | |
4312 | ||
21aa9af0 | 4313 | /* |
2acca55e PZ |
4314 | * If a worker went to sleep, notify and ask workqueue |
4315 | * whether it wants to wake up a task to maintain | |
4316 | * concurrency. | |
21aa9af0 TH |
4317 | */ |
4318 | if (prev->flags & PF_WQ_WORKER) { | |
4319 | struct task_struct *to_wakeup; | |
4320 | ||
4321 | to_wakeup = wq_worker_sleeping(prev, cpu); | |
4322 | if (to_wakeup) | |
4323 | try_to_wake_up_local(to_wakeup); | |
4324 | } | |
fd2f4419 | 4325 | |
6631e635 | 4326 | /* |
2acca55e PZ |
4327 | * If we are going to sleep and we have plugged IO |
4328 | * queued, make sure to submit it to avoid deadlocks. | |
6631e635 LT |
4329 | */ |
4330 | if (blk_needs_flush_plug(prev)) { | |
4331 | raw_spin_unlock(&rq->lock); | |
a237c1c5 | 4332 | blk_schedule_flush_plug(prev); |
6631e635 LT |
4333 | raw_spin_lock(&rq->lock); |
4334 | } | |
21aa9af0 | 4335 | } |
dd41f596 | 4336 | switch_count = &prev->nvcsw; |
1da177e4 LT |
4337 | } |
4338 | ||
3f029d3c | 4339 | pre_schedule(rq, prev); |
f65eda4f | 4340 | |
dd41f596 | 4341 | if (unlikely(!rq->nr_running)) |
1da177e4 | 4342 | idle_balance(cpu, rq); |
1da177e4 | 4343 | |
df1c99d4 | 4344 | put_prev_task(rq, prev); |
b67802ea | 4345 | next = pick_next_task(rq); |
f26f9aff MG |
4346 | clear_tsk_need_resched(prev); |
4347 | rq->skip_clock_update = 0; | |
1da177e4 | 4348 | |
1da177e4 | 4349 | if (likely(prev != next)) { |
1da177e4 LT |
4350 | rq->nr_switches++; |
4351 | rq->curr = next; | |
4352 | ++*switch_count; | |
4353 | ||
dd41f596 | 4354 | context_switch(rq, prev, next); /* unlocks the rq */ |
8f4d37ec | 4355 | /* |
246d86b5 ON |
4356 | * The context switch have flipped the stack from under us |
4357 | * and restored the local variables which were saved when | |
4358 | * this task called schedule() in the past. prev == current | |
4359 | * is still correct, but it can be moved to another cpu/rq. | |
8f4d37ec PZ |
4360 | */ |
4361 | cpu = smp_processor_id(); | |
4362 | rq = cpu_rq(cpu); | |
1da177e4 | 4363 | } else |
05fa785c | 4364 | raw_spin_unlock_irq(&rq->lock); |
1da177e4 | 4365 | |
3f029d3c | 4366 | post_schedule(rq); |
1da177e4 | 4367 | |
1da177e4 | 4368 | preempt_enable_no_resched(); |
ff743345 | 4369 | if (need_resched()) |
1da177e4 LT |
4370 | goto need_resched; |
4371 | } | |
1da177e4 LT |
4372 | EXPORT_SYMBOL(schedule); |
4373 | ||
c08f7829 | 4374 | #ifdef CONFIG_MUTEX_SPIN_ON_OWNER |
0d66bf6d | 4375 | |
c6eb3dda PZ |
4376 | static inline bool owner_running(struct mutex *lock, struct task_struct *owner) |
4377 | { | |
c6eb3dda | 4378 | if (lock->owner != owner) |
307bf980 | 4379 | return false; |
0d66bf6d PZ |
4380 | |
4381 | /* | |
c6eb3dda PZ |
4382 | * Ensure we emit the owner->on_cpu, dereference _after_ checking |
4383 | * lock->owner still matches owner, if that fails, owner might | |
4384 | * point to free()d memory, if it still matches, the rcu_read_lock() | |
4385 | * ensures the memory stays valid. | |
0d66bf6d | 4386 | */ |
c6eb3dda | 4387 | barrier(); |
0d66bf6d | 4388 | |
307bf980 | 4389 | return owner->on_cpu; |
c6eb3dda | 4390 | } |
0d66bf6d | 4391 | |
c6eb3dda PZ |
4392 | /* |
4393 | * Look out! "owner" is an entirely speculative pointer | |
4394 | * access and not reliable. | |
4395 | */ | |
4396 | int mutex_spin_on_owner(struct mutex *lock, struct task_struct *owner) | |
4397 | { | |
4398 | if (!sched_feat(OWNER_SPIN)) | |
4399 | return 0; | |
0d66bf6d | 4400 | |
307bf980 | 4401 | rcu_read_lock(); |
c6eb3dda PZ |
4402 | while (owner_running(lock, owner)) { |
4403 | if (need_resched()) | |
307bf980 | 4404 | break; |
0d66bf6d | 4405 | |
335d7afb | 4406 | arch_mutex_cpu_relax(); |
0d66bf6d | 4407 | } |
307bf980 | 4408 | rcu_read_unlock(); |
4b402210 | 4409 | |
c6eb3dda | 4410 | /* |
307bf980 TG |
4411 | * We break out the loop above on need_resched() and when the |
4412 | * owner changed, which is a sign for heavy contention. Return | |
4413 | * success only when lock->owner is NULL. | |
c6eb3dda | 4414 | */ |
307bf980 | 4415 | return lock->owner == NULL; |
0d66bf6d PZ |
4416 | } |
4417 | #endif | |
4418 | ||
1da177e4 LT |
4419 | #ifdef CONFIG_PREEMPT |
4420 | /* | |
2ed6e34f | 4421 | * this is the entry point to schedule() from in-kernel preemption |
41a2d6cf | 4422 | * off of preempt_enable. Kernel preemptions off return from interrupt |
1da177e4 LT |
4423 | * occur there and call schedule directly. |
4424 | */ | |
d1f74e20 | 4425 | asmlinkage void __sched notrace preempt_schedule(void) |
1da177e4 LT |
4426 | { |
4427 | struct thread_info *ti = current_thread_info(); | |
6478d880 | 4428 | |
1da177e4 LT |
4429 | /* |
4430 | * If there is a non-zero preempt_count or interrupts are disabled, | |
41a2d6cf | 4431 | * we do not want to preempt the current task. Just return.. |
1da177e4 | 4432 | */ |
beed33a8 | 4433 | if (likely(ti->preempt_count || irqs_disabled())) |
1da177e4 LT |
4434 | return; |
4435 | ||
3a5c359a | 4436 | do { |
d1f74e20 | 4437 | add_preempt_count_notrace(PREEMPT_ACTIVE); |
3a5c359a | 4438 | schedule(); |
d1f74e20 | 4439 | sub_preempt_count_notrace(PREEMPT_ACTIVE); |
1da177e4 | 4440 | |
3a5c359a AK |
4441 | /* |
4442 | * Check again in case we missed a preemption opportunity | |
4443 | * between schedule and now. | |
4444 | */ | |
4445 | barrier(); | |
5ed0cec0 | 4446 | } while (need_resched()); |
1da177e4 | 4447 | } |
1da177e4 LT |
4448 | EXPORT_SYMBOL(preempt_schedule); |
4449 | ||
4450 | /* | |
2ed6e34f | 4451 | * this is the entry point to schedule() from kernel preemption |
1da177e4 LT |
4452 | * off of irq context. |
4453 | * Note, that this is called and return with irqs disabled. This will | |
4454 | * protect us against recursive calling from irq. | |
4455 | */ | |
4456 | asmlinkage void __sched preempt_schedule_irq(void) | |
4457 | { | |
4458 | struct thread_info *ti = current_thread_info(); | |
6478d880 | 4459 | |
2ed6e34f | 4460 | /* Catch callers which need to be fixed */ |
1da177e4 LT |
4461 | BUG_ON(ti->preempt_count || !irqs_disabled()); |
4462 | ||
3a5c359a AK |
4463 | do { |
4464 | add_preempt_count(PREEMPT_ACTIVE); | |
3a5c359a AK |
4465 | local_irq_enable(); |
4466 | schedule(); | |
4467 | local_irq_disable(); | |
3a5c359a | 4468 | sub_preempt_count(PREEMPT_ACTIVE); |
1da177e4 | 4469 | |
3a5c359a AK |
4470 | /* |
4471 | * Check again in case we missed a preemption opportunity | |
4472 | * between schedule and now. | |
4473 | */ | |
4474 | barrier(); | |
5ed0cec0 | 4475 | } while (need_resched()); |
1da177e4 LT |
4476 | } |
4477 | ||
4478 | #endif /* CONFIG_PREEMPT */ | |
4479 | ||
63859d4f | 4480 | int default_wake_function(wait_queue_t *curr, unsigned mode, int wake_flags, |
95cdf3b7 | 4481 | void *key) |
1da177e4 | 4482 | { |
63859d4f | 4483 | return try_to_wake_up(curr->private, mode, wake_flags); |
1da177e4 | 4484 | } |
1da177e4 LT |
4485 | EXPORT_SYMBOL(default_wake_function); |
4486 | ||
4487 | /* | |
41a2d6cf IM |
4488 | * The core wakeup function. Non-exclusive wakeups (nr_exclusive == 0) just |
4489 | * wake everything up. If it's an exclusive wakeup (nr_exclusive == small +ve | |
1da177e4 LT |
4490 | * number) then we wake all the non-exclusive tasks and one exclusive task. |
4491 | * | |
4492 | * There are circumstances in which we can try to wake a task which has already | |
41a2d6cf | 4493 | * started to run but is not in state TASK_RUNNING. try_to_wake_up() returns |
1da177e4 LT |
4494 | * zero in this (rare) case, and we handle it by continuing to scan the queue. |
4495 | */ | |
78ddb08f | 4496 | static void __wake_up_common(wait_queue_head_t *q, unsigned int mode, |
63859d4f | 4497 | int nr_exclusive, int wake_flags, void *key) |
1da177e4 | 4498 | { |
2e45874c | 4499 | wait_queue_t *curr, *next; |
1da177e4 | 4500 | |
2e45874c | 4501 | list_for_each_entry_safe(curr, next, &q->task_list, task_list) { |
48f24c4d IM |
4502 | unsigned flags = curr->flags; |
4503 | ||
63859d4f | 4504 | if (curr->func(curr, mode, wake_flags, key) && |
48f24c4d | 4505 | (flags & WQ_FLAG_EXCLUSIVE) && !--nr_exclusive) |
1da177e4 LT |
4506 | break; |
4507 | } | |
4508 | } | |
4509 | ||
4510 | /** | |
4511 | * __wake_up - wake up threads blocked on a waitqueue. | |
4512 | * @q: the waitqueue | |
4513 | * @mode: which threads | |
4514 | * @nr_exclusive: how many wake-one or wake-many threads to wake up | |
67be2dd1 | 4515 | * @key: is directly passed to the wakeup function |
50fa610a DH |
4516 | * |
4517 | * It may be assumed that this function implies a write memory barrier before | |
4518 | * changing the task state if and only if any tasks are woken up. | |
1da177e4 | 4519 | */ |
7ad5b3a5 | 4520 | void __wake_up(wait_queue_head_t *q, unsigned int mode, |
95cdf3b7 | 4521 | int nr_exclusive, void *key) |
1da177e4 LT |
4522 | { |
4523 | unsigned long flags; | |
4524 | ||
4525 | spin_lock_irqsave(&q->lock, flags); | |
4526 | __wake_up_common(q, mode, nr_exclusive, 0, key); | |
4527 | spin_unlock_irqrestore(&q->lock, flags); | |
4528 | } | |
1da177e4 LT |
4529 | EXPORT_SYMBOL(__wake_up); |
4530 | ||
4531 | /* | |
4532 | * Same as __wake_up but called with the spinlock in wait_queue_head_t held. | |
4533 | */ | |
7ad5b3a5 | 4534 | void __wake_up_locked(wait_queue_head_t *q, unsigned int mode) |
1da177e4 LT |
4535 | { |
4536 | __wake_up_common(q, mode, 1, 0, NULL); | |
4537 | } | |
22c43c81 | 4538 | EXPORT_SYMBOL_GPL(__wake_up_locked); |
1da177e4 | 4539 | |
4ede816a DL |
4540 | void __wake_up_locked_key(wait_queue_head_t *q, unsigned int mode, void *key) |
4541 | { | |
4542 | __wake_up_common(q, mode, 1, 0, key); | |
4543 | } | |
bf294b41 | 4544 | EXPORT_SYMBOL_GPL(__wake_up_locked_key); |
4ede816a | 4545 | |
1da177e4 | 4546 | /** |
4ede816a | 4547 | * __wake_up_sync_key - wake up threads blocked on a waitqueue. |
1da177e4 LT |
4548 | * @q: the waitqueue |
4549 | * @mode: which threads | |
4550 | * @nr_exclusive: how many wake-one or wake-many threads to wake up | |
4ede816a | 4551 | * @key: opaque value to be passed to wakeup targets |
1da177e4 LT |
4552 | * |
4553 | * The sync wakeup differs that the waker knows that it will schedule | |
4554 | * away soon, so while the target thread will be woken up, it will not | |
4555 | * be migrated to another CPU - ie. the two threads are 'synchronized' | |
4556 | * with each other. This can prevent needless bouncing between CPUs. | |
4557 | * | |
4558 | * On UP it can prevent extra preemption. | |
50fa610a DH |
4559 | * |
4560 | * It may be assumed that this function implies a write memory barrier before | |
4561 | * changing the task state if and only if any tasks are woken up. | |
1da177e4 | 4562 | */ |
4ede816a DL |
4563 | void __wake_up_sync_key(wait_queue_head_t *q, unsigned int mode, |
4564 | int nr_exclusive, void *key) | |
1da177e4 LT |
4565 | { |
4566 | unsigned long flags; | |
7d478721 | 4567 | int wake_flags = WF_SYNC; |
1da177e4 LT |
4568 | |
4569 | if (unlikely(!q)) | |
4570 | return; | |
4571 | ||
4572 | if (unlikely(!nr_exclusive)) | |
7d478721 | 4573 | wake_flags = 0; |
1da177e4 LT |
4574 | |
4575 | spin_lock_irqsave(&q->lock, flags); | |
7d478721 | 4576 | __wake_up_common(q, mode, nr_exclusive, wake_flags, key); |
1da177e4 LT |
4577 | spin_unlock_irqrestore(&q->lock, flags); |
4578 | } | |
4ede816a DL |
4579 | EXPORT_SYMBOL_GPL(__wake_up_sync_key); |
4580 | ||
4581 | /* | |
4582 | * __wake_up_sync - see __wake_up_sync_key() | |
4583 | */ | |
4584 | void __wake_up_sync(wait_queue_head_t *q, unsigned int mode, int nr_exclusive) | |
4585 | { | |
4586 | __wake_up_sync_key(q, mode, nr_exclusive, NULL); | |
4587 | } | |
1da177e4 LT |
4588 | EXPORT_SYMBOL_GPL(__wake_up_sync); /* For internal use only */ |
4589 | ||
65eb3dc6 KD |
4590 | /** |
4591 | * complete: - signals a single thread waiting on this completion | |
4592 | * @x: holds the state of this particular completion | |
4593 | * | |
4594 | * This will wake up a single thread waiting on this completion. Threads will be | |
4595 | * awakened in the same order in which they were queued. | |
4596 | * | |
4597 | * See also complete_all(), wait_for_completion() and related routines. | |
50fa610a DH |
4598 | * |
4599 | * It may be assumed that this function implies a write memory barrier before | |
4600 | * changing the task state if and only if any tasks are woken up. | |
65eb3dc6 | 4601 | */ |
b15136e9 | 4602 | void complete(struct completion *x) |
1da177e4 LT |
4603 | { |
4604 | unsigned long flags; | |
4605 | ||
4606 | spin_lock_irqsave(&x->wait.lock, flags); | |
4607 | x->done++; | |
d9514f6c | 4608 | __wake_up_common(&x->wait, TASK_NORMAL, 1, 0, NULL); |
1da177e4 LT |
4609 | spin_unlock_irqrestore(&x->wait.lock, flags); |
4610 | } | |
4611 | EXPORT_SYMBOL(complete); | |
4612 | ||
65eb3dc6 KD |
4613 | /** |
4614 | * complete_all: - signals all threads waiting on this completion | |
4615 | * @x: holds the state of this particular completion | |
4616 | * | |
4617 | * This will wake up all threads waiting on this particular completion event. | |
50fa610a DH |
4618 | * |
4619 | * It may be assumed that this function implies a write memory barrier before | |
4620 | * changing the task state if and only if any tasks are woken up. | |
65eb3dc6 | 4621 | */ |
b15136e9 | 4622 | void complete_all(struct completion *x) |
1da177e4 LT |
4623 | { |
4624 | unsigned long flags; | |
4625 | ||
4626 | spin_lock_irqsave(&x->wait.lock, flags); | |
4627 | x->done += UINT_MAX/2; | |
d9514f6c | 4628 | __wake_up_common(&x->wait, TASK_NORMAL, 0, 0, NULL); |
1da177e4 LT |
4629 | spin_unlock_irqrestore(&x->wait.lock, flags); |
4630 | } | |
4631 | EXPORT_SYMBOL(complete_all); | |
4632 | ||
8cbbe86d AK |
4633 | static inline long __sched |
4634 | do_wait_for_common(struct completion *x, long timeout, int state) | |
1da177e4 | 4635 | { |
1da177e4 LT |
4636 | if (!x->done) { |
4637 | DECLARE_WAITQUEUE(wait, current); | |
4638 | ||
a93d2f17 | 4639 | __add_wait_queue_tail_exclusive(&x->wait, &wait); |
1da177e4 | 4640 | do { |
94d3d824 | 4641 | if (signal_pending_state(state, current)) { |
ea71a546 ON |
4642 | timeout = -ERESTARTSYS; |
4643 | break; | |
8cbbe86d AK |
4644 | } |
4645 | __set_current_state(state); | |
1da177e4 LT |
4646 | spin_unlock_irq(&x->wait.lock); |
4647 | timeout = schedule_timeout(timeout); | |
4648 | spin_lock_irq(&x->wait.lock); | |
ea71a546 | 4649 | } while (!x->done && timeout); |
1da177e4 | 4650 | __remove_wait_queue(&x->wait, &wait); |
ea71a546 ON |
4651 | if (!x->done) |
4652 | return timeout; | |
1da177e4 LT |
4653 | } |
4654 | x->done--; | |
ea71a546 | 4655 | return timeout ?: 1; |
1da177e4 | 4656 | } |
1da177e4 | 4657 | |
8cbbe86d AK |
4658 | static long __sched |
4659 | wait_for_common(struct completion *x, long timeout, int state) | |
1da177e4 | 4660 | { |
1da177e4 LT |
4661 | might_sleep(); |
4662 | ||
4663 | spin_lock_irq(&x->wait.lock); | |
8cbbe86d | 4664 | timeout = do_wait_for_common(x, timeout, state); |
1da177e4 | 4665 | spin_unlock_irq(&x->wait.lock); |
8cbbe86d AK |
4666 | return timeout; |
4667 | } | |
1da177e4 | 4668 | |
65eb3dc6 KD |
4669 | /** |
4670 | * wait_for_completion: - waits for completion of a task | |
4671 | * @x: holds the state of this particular completion | |
4672 | * | |
4673 | * This waits to be signaled for completion of a specific task. It is NOT | |
4674 | * interruptible and there is no timeout. | |
4675 | * | |
4676 | * See also similar routines (i.e. wait_for_completion_timeout()) with timeout | |
4677 | * and interrupt capability. Also see complete(). | |
4678 | */ | |
b15136e9 | 4679 | void __sched wait_for_completion(struct completion *x) |
8cbbe86d AK |
4680 | { |
4681 | wait_for_common(x, MAX_SCHEDULE_TIMEOUT, TASK_UNINTERRUPTIBLE); | |
1da177e4 | 4682 | } |
8cbbe86d | 4683 | EXPORT_SYMBOL(wait_for_completion); |
1da177e4 | 4684 | |
65eb3dc6 KD |
4685 | /** |
4686 | * wait_for_completion_timeout: - waits for completion of a task (w/timeout) | |
4687 | * @x: holds the state of this particular completion | |
4688 | * @timeout: timeout value in jiffies | |
4689 | * | |
4690 | * This waits for either a completion of a specific task to be signaled or for a | |
4691 | * specified timeout to expire. The timeout is in jiffies. It is not | |
4692 | * interruptible. | |
4693 | */ | |
b15136e9 | 4694 | unsigned long __sched |
8cbbe86d | 4695 | wait_for_completion_timeout(struct completion *x, unsigned long timeout) |
1da177e4 | 4696 | { |
8cbbe86d | 4697 | return wait_for_common(x, timeout, TASK_UNINTERRUPTIBLE); |
1da177e4 | 4698 | } |
8cbbe86d | 4699 | EXPORT_SYMBOL(wait_for_completion_timeout); |
1da177e4 | 4700 | |
65eb3dc6 KD |
4701 | /** |
4702 | * wait_for_completion_interruptible: - waits for completion of a task (w/intr) | |
4703 | * @x: holds the state of this particular completion | |
4704 | * | |
4705 | * This waits for completion of a specific task to be signaled. It is | |
4706 | * interruptible. | |
4707 | */ | |
8cbbe86d | 4708 | int __sched wait_for_completion_interruptible(struct completion *x) |
0fec171c | 4709 | { |
51e97990 AK |
4710 | long t = wait_for_common(x, MAX_SCHEDULE_TIMEOUT, TASK_INTERRUPTIBLE); |
4711 | if (t == -ERESTARTSYS) | |
4712 | return t; | |
4713 | return 0; | |
0fec171c | 4714 | } |
8cbbe86d | 4715 | EXPORT_SYMBOL(wait_for_completion_interruptible); |
1da177e4 | 4716 | |
65eb3dc6 KD |
4717 | /** |
4718 | * wait_for_completion_interruptible_timeout: - waits for completion (w/(to,intr)) | |
4719 | * @x: holds the state of this particular completion | |
4720 | * @timeout: timeout value in jiffies | |
4721 | * | |
4722 | * This waits for either a completion of a specific task to be signaled or for a | |
4723 | * specified timeout to expire. It is interruptible. The timeout is in jiffies. | |
4724 | */ | |
6bf41237 | 4725 | long __sched |
8cbbe86d AK |
4726 | wait_for_completion_interruptible_timeout(struct completion *x, |
4727 | unsigned long timeout) | |
0fec171c | 4728 | { |
8cbbe86d | 4729 | return wait_for_common(x, timeout, TASK_INTERRUPTIBLE); |
0fec171c | 4730 | } |
8cbbe86d | 4731 | EXPORT_SYMBOL(wait_for_completion_interruptible_timeout); |
1da177e4 | 4732 | |
65eb3dc6 KD |
4733 | /** |
4734 | * wait_for_completion_killable: - waits for completion of a task (killable) | |
4735 | * @x: holds the state of this particular completion | |
4736 | * | |
4737 | * This waits to be signaled for completion of a specific task. It can be | |
4738 | * interrupted by a kill signal. | |
4739 | */ | |
009e577e MW |
4740 | int __sched wait_for_completion_killable(struct completion *x) |
4741 | { | |
4742 | long t = wait_for_common(x, MAX_SCHEDULE_TIMEOUT, TASK_KILLABLE); | |
4743 | if (t == -ERESTARTSYS) | |
4744 | return t; | |
4745 | return 0; | |
4746 | } | |
4747 | EXPORT_SYMBOL(wait_for_completion_killable); | |
4748 | ||
0aa12fb4 SW |
4749 | /** |
4750 | * wait_for_completion_killable_timeout: - waits for completion of a task (w/(to,killable)) | |
4751 | * @x: holds the state of this particular completion | |
4752 | * @timeout: timeout value in jiffies | |
4753 | * | |
4754 | * This waits for either a completion of a specific task to be | |
4755 | * signaled or for a specified timeout to expire. It can be | |
4756 | * interrupted by a kill signal. The timeout is in jiffies. | |
4757 | */ | |
6bf41237 | 4758 | long __sched |
0aa12fb4 SW |
4759 | wait_for_completion_killable_timeout(struct completion *x, |
4760 | unsigned long timeout) | |
4761 | { | |
4762 | return wait_for_common(x, timeout, TASK_KILLABLE); | |
4763 | } | |
4764 | EXPORT_SYMBOL(wait_for_completion_killable_timeout); | |
4765 | ||
be4de352 DC |
4766 | /** |
4767 | * try_wait_for_completion - try to decrement a completion without blocking | |
4768 | * @x: completion structure | |
4769 | * | |
4770 | * Returns: 0 if a decrement cannot be done without blocking | |
4771 | * 1 if a decrement succeeded. | |
4772 | * | |
4773 | * If a completion is being used as a counting completion, | |
4774 | * attempt to decrement the counter without blocking. This | |
4775 | * enables us to avoid waiting if the resource the completion | |
4776 | * is protecting is not available. | |
4777 | */ | |
4778 | bool try_wait_for_completion(struct completion *x) | |
4779 | { | |
7539a3b3 | 4780 | unsigned long flags; |
be4de352 DC |
4781 | int ret = 1; |
4782 | ||
7539a3b3 | 4783 | spin_lock_irqsave(&x->wait.lock, flags); |
be4de352 DC |
4784 | if (!x->done) |
4785 | ret = 0; | |
4786 | else | |
4787 | x->done--; | |
7539a3b3 | 4788 | spin_unlock_irqrestore(&x->wait.lock, flags); |
be4de352 DC |
4789 | return ret; |
4790 | } | |
4791 | EXPORT_SYMBOL(try_wait_for_completion); | |
4792 | ||
4793 | /** | |
4794 | * completion_done - Test to see if a completion has any waiters | |
4795 | * @x: completion structure | |
4796 | * | |
4797 | * Returns: 0 if there are waiters (wait_for_completion() in progress) | |
4798 | * 1 if there are no waiters. | |
4799 | * | |
4800 | */ | |
4801 | bool completion_done(struct completion *x) | |
4802 | { | |
7539a3b3 | 4803 | unsigned long flags; |
be4de352 DC |
4804 | int ret = 1; |
4805 | ||
7539a3b3 | 4806 | spin_lock_irqsave(&x->wait.lock, flags); |
be4de352 DC |
4807 | if (!x->done) |
4808 | ret = 0; | |
7539a3b3 | 4809 | spin_unlock_irqrestore(&x->wait.lock, flags); |
be4de352 DC |
4810 | return ret; |
4811 | } | |
4812 | EXPORT_SYMBOL(completion_done); | |
4813 | ||
8cbbe86d AK |
4814 | static long __sched |
4815 | sleep_on_common(wait_queue_head_t *q, int state, long timeout) | |
1da177e4 | 4816 | { |
0fec171c IM |
4817 | unsigned long flags; |
4818 | wait_queue_t wait; | |
4819 | ||
4820 | init_waitqueue_entry(&wait, current); | |
1da177e4 | 4821 | |
8cbbe86d | 4822 | __set_current_state(state); |
1da177e4 | 4823 | |
8cbbe86d AK |
4824 | spin_lock_irqsave(&q->lock, flags); |
4825 | __add_wait_queue(q, &wait); | |
4826 | spin_unlock(&q->lock); | |
4827 | timeout = schedule_timeout(timeout); | |
4828 | spin_lock_irq(&q->lock); | |
4829 | __remove_wait_queue(q, &wait); | |
4830 | spin_unlock_irqrestore(&q->lock, flags); | |
4831 | ||
4832 | return timeout; | |
4833 | } | |
4834 | ||
4835 | void __sched interruptible_sleep_on(wait_queue_head_t *q) | |
4836 | { | |
4837 | sleep_on_common(q, TASK_INTERRUPTIBLE, MAX_SCHEDULE_TIMEOUT); | |
1da177e4 | 4838 | } |
1da177e4 LT |
4839 | EXPORT_SYMBOL(interruptible_sleep_on); |
4840 | ||
0fec171c | 4841 | long __sched |
95cdf3b7 | 4842 | interruptible_sleep_on_timeout(wait_queue_head_t *q, long timeout) |
1da177e4 | 4843 | { |
8cbbe86d | 4844 | return sleep_on_common(q, TASK_INTERRUPTIBLE, timeout); |
1da177e4 | 4845 | } |
1da177e4 LT |
4846 | EXPORT_SYMBOL(interruptible_sleep_on_timeout); |
4847 | ||
0fec171c | 4848 | void __sched sleep_on(wait_queue_head_t *q) |
1da177e4 | 4849 | { |
8cbbe86d | 4850 | sleep_on_common(q, TASK_UNINTERRUPTIBLE, MAX_SCHEDULE_TIMEOUT); |
1da177e4 | 4851 | } |
1da177e4 LT |
4852 | EXPORT_SYMBOL(sleep_on); |
4853 | ||
0fec171c | 4854 | long __sched sleep_on_timeout(wait_queue_head_t *q, long timeout) |
1da177e4 | 4855 | { |
8cbbe86d | 4856 | return sleep_on_common(q, TASK_UNINTERRUPTIBLE, timeout); |
1da177e4 | 4857 | } |
1da177e4 LT |
4858 | EXPORT_SYMBOL(sleep_on_timeout); |
4859 | ||
b29739f9 IM |
4860 | #ifdef CONFIG_RT_MUTEXES |
4861 | ||
4862 | /* | |
4863 | * rt_mutex_setprio - set the current priority of a task | |
4864 | * @p: task | |
4865 | * @prio: prio value (kernel-internal form) | |
4866 | * | |
4867 | * This function changes the 'effective' priority of a task. It does | |
4868 | * not touch ->normal_prio like __setscheduler(). | |
4869 | * | |
4870 | * Used by the rt_mutex code to implement priority inheritance logic. | |
4871 | */ | |
36c8b586 | 4872 | void rt_mutex_setprio(struct task_struct *p, int prio) |
b29739f9 | 4873 | { |
83b699ed | 4874 | int oldprio, on_rq, running; |
70b97a7f | 4875 | struct rq *rq; |
83ab0aa0 | 4876 | const struct sched_class *prev_class; |
b29739f9 IM |
4877 | |
4878 | BUG_ON(prio < 0 || prio > MAX_PRIO); | |
4879 | ||
0122ec5b | 4880 | rq = __task_rq_lock(p); |
b29739f9 | 4881 | |
a8027073 | 4882 | trace_sched_pi_setprio(p, prio); |
d5f9f942 | 4883 | oldprio = p->prio; |
83ab0aa0 | 4884 | prev_class = p->sched_class; |
fd2f4419 | 4885 | on_rq = p->on_rq; |
051a1d1a | 4886 | running = task_current(rq, p); |
0e1f3483 | 4887 | if (on_rq) |
69be72c1 | 4888 | dequeue_task(rq, p, 0); |
0e1f3483 HS |
4889 | if (running) |
4890 | p->sched_class->put_prev_task(rq, p); | |
dd41f596 IM |
4891 | |
4892 | if (rt_prio(prio)) | |
4893 | p->sched_class = &rt_sched_class; | |
4894 | else | |
4895 | p->sched_class = &fair_sched_class; | |
4896 | ||
b29739f9 IM |
4897 | p->prio = prio; |
4898 | ||
0e1f3483 HS |
4899 | if (running) |
4900 | p->sched_class->set_curr_task(rq); | |
da7a735e | 4901 | if (on_rq) |
371fd7e7 | 4902 | enqueue_task(rq, p, oldprio < prio ? ENQUEUE_HEAD : 0); |
cb469845 | 4903 | |
da7a735e | 4904 | check_class_changed(rq, p, prev_class, oldprio); |
0122ec5b | 4905 | __task_rq_unlock(rq); |
b29739f9 IM |
4906 | } |
4907 | ||
4908 | #endif | |
4909 | ||
36c8b586 | 4910 | void set_user_nice(struct task_struct *p, long nice) |
1da177e4 | 4911 | { |
dd41f596 | 4912 | int old_prio, delta, on_rq; |
1da177e4 | 4913 | unsigned long flags; |
70b97a7f | 4914 | struct rq *rq; |
1da177e4 LT |
4915 | |
4916 | if (TASK_NICE(p) == nice || nice < -20 || nice > 19) | |
4917 | return; | |
4918 | /* | |
4919 | * We have to be careful, if called from sys_setpriority(), | |
4920 | * the task might be in the middle of scheduling on another CPU. | |
4921 | */ | |
4922 | rq = task_rq_lock(p, &flags); | |
4923 | /* | |
4924 | * The RT priorities are set via sched_setscheduler(), but we still | |
4925 | * allow the 'normal' nice value to be set - but as expected | |
4926 | * it wont have any effect on scheduling until the task is | |
dd41f596 | 4927 | * SCHED_FIFO/SCHED_RR: |
1da177e4 | 4928 | */ |
e05606d3 | 4929 | if (task_has_rt_policy(p)) { |
1da177e4 LT |
4930 | p->static_prio = NICE_TO_PRIO(nice); |
4931 | goto out_unlock; | |
4932 | } | |
fd2f4419 | 4933 | on_rq = p->on_rq; |
c09595f6 | 4934 | if (on_rq) |
69be72c1 | 4935 | dequeue_task(rq, p, 0); |
1da177e4 | 4936 | |
1da177e4 | 4937 | p->static_prio = NICE_TO_PRIO(nice); |
2dd73a4f | 4938 | set_load_weight(p); |
b29739f9 IM |
4939 | old_prio = p->prio; |
4940 | p->prio = effective_prio(p); | |
4941 | delta = p->prio - old_prio; | |
1da177e4 | 4942 | |
dd41f596 | 4943 | if (on_rq) { |
371fd7e7 | 4944 | enqueue_task(rq, p, 0); |
1da177e4 | 4945 | /* |
d5f9f942 AM |
4946 | * If the task increased its priority or is running and |
4947 | * lowered its priority, then reschedule its CPU: | |
1da177e4 | 4948 | */ |
d5f9f942 | 4949 | if (delta < 0 || (delta > 0 && task_running(rq, p))) |
1da177e4 LT |
4950 | resched_task(rq->curr); |
4951 | } | |
4952 | out_unlock: | |
0122ec5b | 4953 | task_rq_unlock(rq, p, &flags); |
1da177e4 | 4954 | } |
1da177e4 LT |
4955 | EXPORT_SYMBOL(set_user_nice); |
4956 | ||
e43379f1 MM |
4957 | /* |
4958 | * can_nice - check if a task can reduce its nice value | |
4959 | * @p: task | |
4960 | * @nice: nice value | |
4961 | */ | |
36c8b586 | 4962 | int can_nice(const struct task_struct *p, const int nice) |
e43379f1 | 4963 | { |
024f4747 MM |
4964 | /* convert nice value [19,-20] to rlimit style value [1,40] */ |
4965 | int nice_rlim = 20 - nice; | |
48f24c4d | 4966 | |
78d7d407 | 4967 | return (nice_rlim <= task_rlimit(p, RLIMIT_NICE) || |
e43379f1 MM |
4968 | capable(CAP_SYS_NICE)); |
4969 | } | |
4970 | ||
1da177e4 LT |
4971 | #ifdef __ARCH_WANT_SYS_NICE |
4972 | ||
4973 | /* | |
4974 | * sys_nice - change the priority of the current process. | |
4975 | * @increment: priority increment | |
4976 | * | |
4977 | * sys_setpriority is a more generic, but much slower function that | |
4978 | * does similar things. | |
4979 | */ | |
5add95d4 | 4980 | SYSCALL_DEFINE1(nice, int, increment) |
1da177e4 | 4981 | { |
48f24c4d | 4982 | long nice, retval; |
1da177e4 LT |
4983 | |
4984 | /* | |
4985 | * Setpriority might change our priority at the same moment. | |
4986 | * We don't have to worry. Conceptually one call occurs first | |
4987 | * and we have a single winner. | |
4988 | */ | |
e43379f1 MM |
4989 | if (increment < -40) |
4990 | increment = -40; | |
1da177e4 LT |
4991 | if (increment > 40) |
4992 | increment = 40; | |
4993 | ||
2b8f836f | 4994 | nice = TASK_NICE(current) + increment; |
1da177e4 LT |
4995 | if (nice < -20) |
4996 | nice = -20; | |
4997 | if (nice > 19) | |
4998 | nice = 19; | |
4999 | ||
e43379f1 MM |
5000 | if (increment < 0 && !can_nice(current, nice)) |
5001 | return -EPERM; | |
5002 | ||
1da177e4 LT |
5003 | retval = security_task_setnice(current, nice); |
5004 | if (retval) | |
5005 | return retval; | |
5006 | ||
5007 | set_user_nice(current, nice); | |
5008 | return 0; | |
5009 | } | |
5010 | ||
5011 | #endif | |
5012 | ||
5013 | /** | |
5014 | * task_prio - return the priority value of a given task. | |
5015 | * @p: the task in question. | |
5016 | * | |
5017 | * This is the priority value as seen by users in /proc. | |
5018 | * RT tasks are offset by -200. Normal tasks are centered | |
5019 | * around 0, value goes from -16 to +15. | |
5020 | */ | |
36c8b586 | 5021 | int task_prio(const struct task_struct *p) |
1da177e4 LT |
5022 | { |
5023 | return p->prio - MAX_RT_PRIO; | |
5024 | } | |
5025 | ||
5026 | /** | |
5027 | * task_nice - return the nice value of a given task. | |
5028 | * @p: the task in question. | |
5029 | */ | |
36c8b586 | 5030 | int task_nice(const struct task_struct *p) |
1da177e4 LT |
5031 | { |
5032 | return TASK_NICE(p); | |
5033 | } | |
150d8bed | 5034 | EXPORT_SYMBOL(task_nice); |
1da177e4 LT |
5035 | |
5036 | /** | |
5037 | * idle_cpu - is a given cpu idle currently? | |
5038 | * @cpu: the processor in question. | |
5039 | */ | |
5040 | int idle_cpu(int cpu) | |
5041 | { | |
5042 | return cpu_curr(cpu) == cpu_rq(cpu)->idle; | |
5043 | } | |
5044 | ||
1da177e4 LT |
5045 | /** |
5046 | * idle_task - return the idle task for a given cpu. | |
5047 | * @cpu: the processor in question. | |
5048 | */ | |
36c8b586 | 5049 | struct task_struct *idle_task(int cpu) |
1da177e4 LT |
5050 | { |
5051 | return cpu_rq(cpu)->idle; | |
5052 | } | |
5053 | ||
5054 | /** | |
5055 | * find_process_by_pid - find a process with a matching PID value. | |
5056 | * @pid: the pid in question. | |
5057 | */ | |
a9957449 | 5058 | static struct task_struct *find_process_by_pid(pid_t pid) |
1da177e4 | 5059 | { |
228ebcbe | 5060 | return pid ? find_task_by_vpid(pid) : current; |
1da177e4 LT |
5061 | } |
5062 | ||
5063 | /* Actually do priority change: must hold rq lock. */ | |
dd41f596 IM |
5064 | static void |
5065 | __setscheduler(struct rq *rq, struct task_struct *p, int policy, int prio) | |
1da177e4 | 5066 | { |
1da177e4 LT |
5067 | p->policy = policy; |
5068 | p->rt_priority = prio; | |
b29739f9 IM |
5069 | p->normal_prio = normal_prio(p); |
5070 | /* we are holding p->pi_lock already */ | |
5071 | p->prio = rt_mutex_getprio(p); | |
ffd44db5 PZ |
5072 | if (rt_prio(p->prio)) |
5073 | p->sched_class = &rt_sched_class; | |
5074 | else | |
5075 | p->sched_class = &fair_sched_class; | |
2dd73a4f | 5076 | set_load_weight(p); |
1da177e4 LT |
5077 | } |
5078 | ||
c69e8d9c DH |
5079 | /* |
5080 | * check the target process has a UID that matches the current process's | |
5081 | */ | |
5082 | static bool check_same_owner(struct task_struct *p) | |
5083 | { | |
5084 | const struct cred *cred = current_cred(), *pcred; | |
5085 | bool match; | |
5086 | ||
5087 | rcu_read_lock(); | |
5088 | pcred = __task_cred(p); | |
b0e77598 SH |
5089 | if (cred->user->user_ns == pcred->user->user_ns) |
5090 | match = (cred->euid == pcred->euid || | |
5091 | cred->euid == pcred->uid); | |
5092 | else | |
5093 | match = false; | |
c69e8d9c DH |
5094 | rcu_read_unlock(); |
5095 | return match; | |
5096 | } | |
5097 | ||
961ccddd | 5098 | static int __sched_setscheduler(struct task_struct *p, int policy, |
fe7de49f | 5099 | const struct sched_param *param, bool user) |
1da177e4 | 5100 | { |
83b699ed | 5101 | int retval, oldprio, oldpolicy = -1, on_rq, running; |
1da177e4 | 5102 | unsigned long flags; |
83ab0aa0 | 5103 | const struct sched_class *prev_class; |
70b97a7f | 5104 | struct rq *rq; |
ca94c442 | 5105 | int reset_on_fork; |
1da177e4 | 5106 | |
66e5393a SR |
5107 | /* may grab non-irq protected spin_locks */ |
5108 | BUG_ON(in_interrupt()); | |
1da177e4 LT |
5109 | recheck: |
5110 | /* double check policy once rq lock held */ | |
ca94c442 LP |
5111 | if (policy < 0) { |
5112 | reset_on_fork = p->sched_reset_on_fork; | |
1da177e4 | 5113 | policy = oldpolicy = p->policy; |
ca94c442 LP |
5114 | } else { |
5115 | reset_on_fork = !!(policy & SCHED_RESET_ON_FORK); | |
5116 | policy &= ~SCHED_RESET_ON_FORK; | |
5117 | ||
5118 | if (policy != SCHED_FIFO && policy != SCHED_RR && | |
5119 | policy != SCHED_NORMAL && policy != SCHED_BATCH && | |
5120 | policy != SCHED_IDLE) | |
5121 | return -EINVAL; | |
5122 | } | |
5123 | ||
1da177e4 LT |
5124 | /* |
5125 | * Valid priorities for SCHED_FIFO and SCHED_RR are | |
dd41f596 IM |
5126 | * 1..MAX_USER_RT_PRIO-1, valid priority for SCHED_NORMAL, |
5127 | * SCHED_BATCH and SCHED_IDLE is 0. | |
1da177e4 LT |
5128 | */ |
5129 | if (param->sched_priority < 0 || | |
95cdf3b7 | 5130 | (p->mm && param->sched_priority > MAX_USER_RT_PRIO-1) || |
d46523ea | 5131 | (!p->mm && param->sched_priority > MAX_RT_PRIO-1)) |
1da177e4 | 5132 | return -EINVAL; |
e05606d3 | 5133 | if (rt_policy(policy) != (param->sched_priority != 0)) |
1da177e4 LT |
5134 | return -EINVAL; |
5135 | ||
37e4ab3f OC |
5136 | /* |
5137 | * Allow unprivileged RT tasks to decrease priority: | |
5138 | */ | |
961ccddd | 5139 | if (user && !capable(CAP_SYS_NICE)) { |
e05606d3 | 5140 | if (rt_policy(policy)) { |
a44702e8 ON |
5141 | unsigned long rlim_rtprio = |
5142 | task_rlimit(p, RLIMIT_RTPRIO); | |
8dc3e909 ON |
5143 | |
5144 | /* can't set/change the rt policy */ | |
5145 | if (policy != p->policy && !rlim_rtprio) | |
5146 | return -EPERM; | |
5147 | ||
5148 | /* can't increase priority */ | |
5149 | if (param->sched_priority > p->rt_priority && | |
5150 | param->sched_priority > rlim_rtprio) | |
5151 | return -EPERM; | |
5152 | } | |
c02aa73b | 5153 | |
dd41f596 | 5154 | /* |
c02aa73b DH |
5155 | * Treat SCHED_IDLE as nice 20. Only allow a switch to |
5156 | * SCHED_NORMAL if the RLIMIT_NICE would normally permit it. | |
dd41f596 | 5157 | */ |
c02aa73b DH |
5158 | if (p->policy == SCHED_IDLE && policy != SCHED_IDLE) { |
5159 | if (!can_nice(p, TASK_NICE(p))) | |
5160 | return -EPERM; | |
5161 | } | |
5fe1d75f | 5162 | |
37e4ab3f | 5163 | /* can't change other user's priorities */ |
c69e8d9c | 5164 | if (!check_same_owner(p)) |
37e4ab3f | 5165 | return -EPERM; |
ca94c442 LP |
5166 | |
5167 | /* Normal users shall not reset the sched_reset_on_fork flag */ | |
5168 | if (p->sched_reset_on_fork && !reset_on_fork) | |
5169 | return -EPERM; | |
37e4ab3f | 5170 | } |
1da177e4 | 5171 | |
725aad24 | 5172 | if (user) { |
b0ae1981 | 5173 | retval = security_task_setscheduler(p); |
725aad24 JF |
5174 | if (retval) |
5175 | return retval; | |
5176 | } | |
5177 | ||
b29739f9 IM |
5178 | /* |
5179 | * make sure no PI-waiters arrive (or leave) while we are | |
5180 | * changing the priority of the task: | |
0122ec5b | 5181 | * |
25985edc | 5182 | * To be able to change p->policy safely, the appropriate |
1da177e4 LT |
5183 | * runqueue lock must be held. |
5184 | */ | |
0122ec5b | 5185 | rq = task_rq_lock(p, &flags); |
dc61b1d6 | 5186 | |
34f971f6 PZ |
5187 | /* |
5188 | * Changing the policy of the stop threads its a very bad idea | |
5189 | */ | |
5190 | if (p == rq->stop) { | |
0122ec5b | 5191 | task_rq_unlock(rq, p, &flags); |
34f971f6 PZ |
5192 | return -EINVAL; |
5193 | } | |
5194 | ||
a51e9198 DF |
5195 | /* |
5196 | * If not changing anything there's no need to proceed further: | |
5197 | */ | |
5198 | if (unlikely(policy == p->policy && (!rt_policy(policy) || | |
5199 | param->sched_priority == p->rt_priority))) { | |
5200 | ||
5201 | __task_rq_unlock(rq); | |
5202 | raw_spin_unlock_irqrestore(&p->pi_lock, flags); | |
5203 | return 0; | |
5204 | } | |
5205 | ||
dc61b1d6 PZ |
5206 | #ifdef CONFIG_RT_GROUP_SCHED |
5207 | if (user) { | |
5208 | /* | |
5209 | * Do not allow realtime tasks into groups that have no runtime | |
5210 | * assigned. | |
5211 | */ | |
5212 | if (rt_bandwidth_enabled() && rt_policy(policy) && | |
f4493771 MG |
5213 | task_group(p)->rt_bandwidth.rt_runtime == 0 && |
5214 | !task_group_is_autogroup(task_group(p))) { | |
0122ec5b | 5215 | task_rq_unlock(rq, p, &flags); |
dc61b1d6 PZ |
5216 | return -EPERM; |
5217 | } | |
5218 | } | |
5219 | #endif | |
5220 | ||
1da177e4 LT |
5221 | /* recheck policy now with rq lock held */ |
5222 | if (unlikely(oldpolicy != -1 && oldpolicy != p->policy)) { | |
5223 | policy = oldpolicy = -1; | |
0122ec5b | 5224 | task_rq_unlock(rq, p, &flags); |
1da177e4 LT |
5225 | goto recheck; |
5226 | } | |
fd2f4419 | 5227 | on_rq = p->on_rq; |
051a1d1a | 5228 | running = task_current(rq, p); |
0e1f3483 | 5229 | if (on_rq) |
2e1cb74a | 5230 | deactivate_task(rq, p, 0); |
0e1f3483 HS |
5231 | if (running) |
5232 | p->sched_class->put_prev_task(rq, p); | |
f6b53205 | 5233 | |
ca94c442 LP |
5234 | p->sched_reset_on_fork = reset_on_fork; |
5235 | ||
1da177e4 | 5236 | oldprio = p->prio; |
83ab0aa0 | 5237 | prev_class = p->sched_class; |
dd41f596 | 5238 | __setscheduler(rq, p, policy, param->sched_priority); |
f6b53205 | 5239 | |
0e1f3483 HS |
5240 | if (running) |
5241 | p->sched_class->set_curr_task(rq); | |
da7a735e | 5242 | if (on_rq) |
dd41f596 | 5243 | activate_task(rq, p, 0); |
cb469845 | 5244 | |
da7a735e | 5245 | check_class_changed(rq, p, prev_class, oldprio); |
0122ec5b | 5246 | task_rq_unlock(rq, p, &flags); |
b29739f9 | 5247 | |
95e02ca9 TG |
5248 | rt_mutex_adjust_pi(p); |
5249 | ||
1da177e4 LT |
5250 | return 0; |
5251 | } | |
961ccddd RR |
5252 | |
5253 | /** | |
5254 | * sched_setscheduler - change the scheduling policy and/or RT priority of a thread. | |
5255 | * @p: the task in question. | |
5256 | * @policy: new policy. | |
5257 | * @param: structure containing the new RT priority. | |
5258 | * | |
5259 | * NOTE that the task may be already dead. | |
5260 | */ | |
5261 | int sched_setscheduler(struct task_struct *p, int policy, | |
fe7de49f | 5262 | const struct sched_param *param) |
961ccddd RR |
5263 | { |
5264 | return __sched_setscheduler(p, policy, param, true); | |
5265 | } | |
1da177e4 LT |
5266 | EXPORT_SYMBOL_GPL(sched_setscheduler); |
5267 | ||
961ccddd RR |
5268 | /** |
5269 | * sched_setscheduler_nocheck - change the scheduling policy and/or RT priority of a thread from kernelspace. | |
5270 | * @p: the task in question. | |
5271 | * @policy: new policy. | |
5272 | * @param: structure containing the new RT priority. | |
5273 | * | |
5274 | * Just like sched_setscheduler, only don't bother checking if the | |
5275 | * current context has permission. For example, this is needed in | |
5276 | * stop_machine(): we create temporary high priority worker threads, | |
5277 | * but our caller might not have that capability. | |
5278 | */ | |
5279 | int sched_setscheduler_nocheck(struct task_struct *p, int policy, | |
fe7de49f | 5280 | const struct sched_param *param) |
961ccddd RR |
5281 | { |
5282 | return __sched_setscheduler(p, policy, param, false); | |
5283 | } | |
5284 | ||
95cdf3b7 IM |
5285 | static int |
5286 | do_sched_setscheduler(pid_t pid, int policy, struct sched_param __user *param) | |
1da177e4 | 5287 | { |
1da177e4 LT |
5288 | struct sched_param lparam; |
5289 | struct task_struct *p; | |
36c8b586 | 5290 | int retval; |
1da177e4 LT |
5291 | |
5292 | if (!param || pid < 0) | |
5293 | return -EINVAL; | |
5294 | if (copy_from_user(&lparam, param, sizeof(struct sched_param))) | |
5295 | return -EFAULT; | |
5fe1d75f ON |
5296 | |
5297 | rcu_read_lock(); | |
5298 | retval = -ESRCH; | |
1da177e4 | 5299 | p = find_process_by_pid(pid); |
5fe1d75f ON |
5300 | if (p != NULL) |
5301 | retval = sched_setscheduler(p, policy, &lparam); | |
5302 | rcu_read_unlock(); | |
36c8b586 | 5303 | |
1da177e4 LT |
5304 | return retval; |
5305 | } | |
5306 | ||
5307 | /** | |
5308 | * sys_sched_setscheduler - set/change the scheduler policy and RT priority | |
5309 | * @pid: the pid in question. | |
5310 | * @policy: new policy. | |
5311 | * @param: structure containing the new RT priority. | |
5312 | */ | |
5add95d4 HC |
5313 | SYSCALL_DEFINE3(sched_setscheduler, pid_t, pid, int, policy, |
5314 | struct sched_param __user *, param) | |
1da177e4 | 5315 | { |
c21761f1 JB |
5316 | /* negative values for policy are not valid */ |
5317 | if (policy < 0) | |
5318 | return -EINVAL; | |
5319 | ||
1da177e4 LT |
5320 | return do_sched_setscheduler(pid, policy, param); |
5321 | } | |
5322 | ||
5323 | /** | |
5324 | * sys_sched_setparam - set/change the RT priority of a thread | |
5325 | * @pid: the pid in question. | |
5326 | * @param: structure containing the new RT priority. | |
5327 | */ | |
5add95d4 | 5328 | SYSCALL_DEFINE2(sched_setparam, pid_t, pid, struct sched_param __user *, param) |
1da177e4 LT |
5329 | { |
5330 | return do_sched_setscheduler(pid, -1, param); | |
5331 | } | |
5332 | ||
5333 | /** | |
5334 | * sys_sched_getscheduler - get the policy (scheduling class) of a thread | |
5335 | * @pid: the pid in question. | |
5336 | */ | |
5add95d4 | 5337 | SYSCALL_DEFINE1(sched_getscheduler, pid_t, pid) |
1da177e4 | 5338 | { |
36c8b586 | 5339 | struct task_struct *p; |
3a5c359a | 5340 | int retval; |
1da177e4 LT |
5341 | |
5342 | if (pid < 0) | |
3a5c359a | 5343 | return -EINVAL; |
1da177e4 LT |
5344 | |
5345 | retval = -ESRCH; | |
5fe85be0 | 5346 | rcu_read_lock(); |
1da177e4 LT |
5347 | p = find_process_by_pid(pid); |
5348 | if (p) { | |
5349 | retval = security_task_getscheduler(p); | |
5350 | if (!retval) | |
ca94c442 LP |
5351 | retval = p->policy |
5352 | | (p->sched_reset_on_fork ? SCHED_RESET_ON_FORK : 0); | |
1da177e4 | 5353 | } |
5fe85be0 | 5354 | rcu_read_unlock(); |
1da177e4 LT |
5355 | return retval; |
5356 | } | |
5357 | ||
5358 | /** | |
ca94c442 | 5359 | * sys_sched_getparam - get the RT priority of a thread |
1da177e4 LT |
5360 | * @pid: the pid in question. |
5361 | * @param: structure containing the RT priority. | |
5362 | */ | |
5add95d4 | 5363 | SYSCALL_DEFINE2(sched_getparam, pid_t, pid, struct sched_param __user *, param) |
1da177e4 LT |
5364 | { |
5365 | struct sched_param lp; | |
36c8b586 | 5366 | struct task_struct *p; |
3a5c359a | 5367 | int retval; |
1da177e4 LT |
5368 | |
5369 | if (!param || pid < 0) | |
3a5c359a | 5370 | return -EINVAL; |
1da177e4 | 5371 | |
5fe85be0 | 5372 | rcu_read_lock(); |
1da177e4 LT |
5373 | p = find_process_by_pid(pid); |
5374 | retval = -ESRCH; | |
5375 | if (!p) | |
5376 | goto out_unlock; | |
5377 | ||
5378 | retval = security_task_getscheduler(p); | |
5379 | if (retval) | |
5380 | goto out_unlock; | |
5381 | ||
5382 | lp.sched_priority = p->rt_priority; | |
5fe85be0 | 5383 | rcu_read_unlock(); |
1da177e4 LT |
5384 | |
5385 | /* | |
5386 | * This one might sleep, we cannot do it with a spinlock held ... | |
5387 | */ | |
5388 | retval = copy_to_user(param, &lp, sizeof(*param)) ? -EFAULT : 0; | |
5389 | ||
1da177e4 LT |
5390 | return retval; |
5391 | ||
5392 | out_unlock: | |
5fe85be0 | 5393 | rcu_read_unlock(); |
1da177e4 LT |
5394 | return retval; |
5395 | } | |
5396 | ||
96f874e2 | 5397 | long sched_setaffinity(pid_t pid, const struct cpumask *in_mask) |
1da177e4 | 5398 | { |
5a16f3d3 | 5399 | cpumask_var_t cpus_allowed, new_mask; |
36c8b586 IM |
5400 | struct task_struct *p; |
5401 | int retval; | |
1da177e4 | 5402 | |
95402b38 | 5403 | get_online_cpus(); |
23f5d142 | 5404 | rcu_read_lock(); |
1da177e4 LT |
5405 | |
5406 | p = find_process_by_pid(pid); | |
5407 | if (!p) { | |
23f5d142 | 5408 | rcu_read_unlock(); |
95402b38 | 5409 | put_online_cpus(); |
1da177e4 LT |
5410 | return -ESRCH; |
5411 | } | |
5412 | ||
23f5d142 | 5413 | /* Prevent p going away */ |
1da177e4 | 5414 | get_task_struct(p); |
23f5d142 | 5415 | rcu_read_unlock(); |
1da177e4 | 5416 | |
5a16f3d3 RR |
5417 | if (!alloc_cpumask_var(&cpus_allowed, GFP_KERNEL)) { |
5418 | retval = -ENOMEM; | |
5419 | goto out_put_task; | |
5420 | } | |
5421 | if (!alloc_cpumask_var(&new_mask, GFP_KERNEL)) { | |
5422 | retval = -ENOMEM; | |
5423 | goto out_free_cpus_allowed; | |
5424 | } | |
1da177e4 | 5425 | retval = -EPERM; |
b0e77598 | 5426 | if (!check_same_owner(p) && !task_ns_capable(p, CAP_SYS_NICE)) |
1da177e4 LT |
5427 | goto out_unlock; |
5428 | ||
b0ae1981 | 5429 | retval = security_task_setscheduler(p); |
e7834f8f DQ |
5430 | if (retval) |
5431 | goto out_unlock; | |
5432 | ||
5a16f3d3 RR |
5433 | cpuset_cpus_allowed(p, cpus_allowed); |
5434 | cpumask_and(new_mask, in_mask, cpus_allowed); | |
49246274 | 5435 | again: |
5a16f3d3 | 5436 | retval = set_cpus_allowed_ptr(p, new_mask); |
1da177e4 | 5437 | |
8707d8b8 | 5438 | if (!retval) { |
5a16f3d3 RR |
5439 | cpuset_cpus_allowed(p, cpus_allowed); |
5440 | if (!cpumask_subset(new_mask, cpus_allowed)) { | |
8707d8b8 PM |
5441 | /* |
5442 | * We must have raced with a concurrent cpuset | |
5443 | * update. Just reset the cpus_allowed to the | |
5444 | * cpuset's cpus_allowed | |
5445 | */ | |
5a16f3d3 | 5446 | cpumask_copy(new_mask, cpus_allowed); |
8707d8b8 PM |
5447 | goto again; |
5448 | } | |
5449 | } | |
1da177e4 | 5450 | out_unlock: |
5a16f3d3 RR |
5451 | free_cpumask_var(new_mask); |
5452 | out_free_cpus_allowed: | |
5453 | free_cpumask_var(cpus_allowed); | |
5454 | out_put_task: | |
1da177e4 | 5455 | put_task_struct(p); |
95402b38 | 5456 | put_online_cpus(); |
1da177e4 LT |
5457 | return retval; |
5458 | } | |
5459 | ||
5460 | static int get_user_cpu_mask(unsigned long __user *user_mask_ptr, unsigned len, | |
96f874e2 | 5461 | struct cpumask *new_mask) |
1da177e4 | 5462 | { |
96f874e2 RR |
5463 | if (len < cpumask_size()) |
5464 | cpumask_clear(new_mask); | |
5465 | else if (len > cpumask_size()) | |
5466 | len = cpumask_size(); | |
5467 | ||
1da177e4 LT |
5468 | return copy_from_user(new_mask, user_mask_ptr, len) ? -EFAULT : 0; |
5469 | } | |
5470 | ||
5471 | /** | |
5472 | * sys_sched_setaffinity - set the cpu affinity of a process | |
5473 | * @pid: pid of the process | |
5474 | * @len: length in bytes of the bitmask pointed to by user_mask_ptr | |
5475 | * @user_mask_ptr: user-space pointer to the new cpu mask | |
5476 | */ | |
5add95d4 HC |
5477 | SYSCALL_DEFINE3(sched_setaffinity, pid_t, pid, unsigned int, len, |
5478 | unsigned long __user *, user_mask_ptr) | |
1da177e4 | 5479 | { |
5a16f3d3 | 5480 | cpumask_var_t new_mask; |
1da177e4 LT |
5481 | int retval; |
5482 | ||
5a16f3d3 RR |
5483 | if (!alloc_cpumask_var(&new_mask, GFP_KERNEL)) |
5484 | return -ENOMEM; | |
1da177e4 | 5485 | |
5a16f3d3 RR |
5486 | retval = get_user_cpu_mask(user_mask_ptr, len, new_mask); |
5487 | if (retval == 0) | |
5488 | retval = sched_setaffinity(pid, new_mask); | |
5489 | free_cpumask_var(new_mask); | |
5490 | return retval; | |
1da177e4 LT |
5491 | } |
5492 | ||
96f874e2 | 5493 | long sched_getaffinity(pid_t pid, struct cpumask *mask) |
1da177e4 | 5494 | { |
36c8b586 | 5495 | struct task_struct *p; |
31605683 | 5496 | unsigned long flags; |
1da177e4 | 5497 | int retval; |
1da177e4 | 5498 | |
95402b38 | 5499 | get_online_cpus(); |
23f5d142 | 5500 | rcu_read_lock(); |
1da177e4 LT |
5501 | |
5502 | retval = -ESRCH; | |
5503 | p = find_process_by_pid(pid); | |
5504 | if (!p) | |
5505 | goto out_unlock; | |
5506 | ||
e7834f8f DQ |
5507 | retval = security_task_getscheduler(p); |
5508 | if (retval) | |
5509 | goto out_unlock; | |
5510 | ||
013fdb80 | 5511 | raw_spin_lock_irqsave(&p->pi_lock, flags); |
96f874e2 | 5512 | cpumask_and(mask, &p->cpus_allowed, cpu_online_mask); |
013fdb80 | 5513 | raw_spin_unlock_irqrestore(&p->pi_lock, flags); |
1da177e4 LT |
5514 | |
5515 | out_unlock: | |
23f5d142 | 5516 | rcu_read_unlock(); |
95402b38 | 5517 | put_online_cpus(); |
1da177e4 | 5518 | |
9531b62f | 5519 | return retval; |
1da177e4 LT |
5520 | } |
5521 | ||
5522 | /** | |
5523 | * sys_sched_getaffinity - get the cpu affinity of a process | |
5524 | * @pid: pid of the process | |
5525 | * @len: length in bytes of the bitmask pointed to by user_mask_ptr | |
5526 | * @user_mask_ptr: user-space pointer to hold the current cpu mask | |
5527 | */ | |
5add95d4 HC |
5528 | SYSCALL_DEFINE3(sched_getaffinity, pid_t, pid, unsigned int, len, |
5529 | unsigned long __user *, user_mask_ptr) | |
1da177e4 LT |
5530 | { |
5531 | int ret; | |
f17c8607 | 5532 | cpumask_var_t mask; |
1da177e4 | 5533 | |
84fba5ec | 5534 | if ((len * BITS_PER_BYTE) < nr_cpu_ids) |
cd3d8031 KM |
5535 | return -EINVAL; |
5536 | if (len & (sizeof(unsigned long)-1)) | |
1da177e4 LT |
5537 | return -EINVAL; |
5538 | ||
f17c8607 RR |
5539 | if (!alloc_cpumask_var(&mask, GFP_KERNEL)) |
5540 | return -ENOMEM; | |
1da177e4 | 5541 | |
f17c8607 RR |
5542 | ret = sched_getaffinity(pid, mask); |
5543 | if (ret == 0) { | |
8bc037fb | 5544 | size_t retlen = min_t(size_t, len, cpumask_size()); |
cd3d8031 KM |
5545 | |
5546 | if (copy_to_user(user_mask_ptr, mask, retlen)) | |
f17c8607 RR |
5547 | ret = -EFAULT; |
5548 | else | |
cd3d8031 | 5549 | ret = retlen; |
f17c8607 RR |
5550 | } |
5551 | free_cpumask_var(mask); | |
1da177e4 | 5552 | |
f17c8607 | 5553 | return ret; |
1da177e4 LT |
5554 | } |
5555 | ||
5556 | /** | |
5557 | * sys_sched_yield - yield the current processor to other threads. | |
5558 | * | |
dd41f596 IM |
5559 | * This function yields the current CPU to other tasks. If there are no |
5560 | * other threads running on this CPU then this function will return. | |
1da177e4 | 5561 | */ |
5add95d4 | 5562 | SYSCALL_DEFINE0(sched_yield) |
1da177e4 | 5563 | { |
70b97a7f | 5564 | struct rq *rq = this_rq_lock(); |
1da177e4 | 5565 | |
2d72376b | 5566 | schedstat_inc(rq, yld_count); |
4530d7ab | 5567 | current->sched_class->yield_task(rq); |
1da177e4 LT |
5568 | |
5569 | /* | |
5570 | * Since we are going to call schedule() anyway, there's | |
5571 | * no need to preempt or enable interrupts: | |
5572 | */ | |
5573 | __release(rq->lock); | |
8a25d5de | 5574 | spin_release(&rq->lock.dep_map, 1, _THIS_IP_); |
9828ea9d | 5575 | do_raw_spin_unlock(&rq->lock); |
1da177e4 LT |
5576 | preempt_enable_no_resched(); |
5577 | ||
5578 | schedule(); | |
5579 | ||
5580 | return 0; | |
5581 | } | |
5582 | ||
d86ee480 PZ |
5583 | static inline int should_resched(void) |
5584 | { | |
5585 | return need_resched() && !(preempt_count() & PREEMPT_ACTIVE); | |
5586 | } | |
5587 | ||
e7b38404 | 5588 | static void __cond_resched(void) |
1da177e4 | 5589 | { |
e7aaaa69 FW |
5590 | add_preempt_count(PREEMPT_ACTIVE); |
5591 | schedule(); | |
5592 | sub_preempt_count(PREEMPT_ACTIVE); | |
1da177e4 LT |
5593 | } |
5594 | ||
02b67cc3 | 5595 | int __sched _cond_resched(void) |
1da177e4 | 5596 | { |
d86ee480 | 5597 | if (should_resched()) { |
1da177e4 LT |
5598 | __cond_resched(); |
5599 | return 1; | |
5600 | } | |
5601 | return 0; | |
5602 | } | |
02b67cc3 | 5603 | EXPORT_SYMBOL(_cond_resched); |
1da177e4 LT |
5604 | |
5605 | /* | |
613afbf8 | 5606 | * __cond_resched_lock() - if a reschedule is pending, drop the given lock, |
1da177e4 LT |
5607 | * call schedule, and on return reacquire the lock. |
5608 | * | |
41a2d6cf | 5609 | * This works OK both with and without CONFIG_PREEMPT. We do strange low-level |
1da177e4 LT |
5610 | * operations here to prevent schedule() from being called twice (once via |
5611 | * spin_unlock(), once by hand). | |
5612 | */ | |
613afbf8 | 5613 | int __cond_resched_lock(spinlock_t *lock) |
1da177e4 | 5614 | { |
d86ee480 | 5615 | int resched = should_resched(); |
6df3cecb JK |
5616 | int ret = 0; |
5617 | ||
f607c668 PZ |
5618 | lockdep_assert_held(lock); |
5619 | ||
95c354fe | 5620 | if (spin_needbreak(lock) || resched) { |
1da177e4 | 5621 | spin_unlock(lock); |
d86ee480 | 5622 | if (resched) |
95c354fe NP |
5623 | __cond_resched(); |
5624 | else | |
5625 | cpu_relax(); | |
6df3cecb | 5626 | ret = 1; |
1da177e4 | 5627 | spin_lock(lock); |
1da177e4 | 5628 | } |
6df3cecb | 5629 | return ret; |
1da177e4 | 5630 | } |
613afbf8 | 5631 | EXPORT_SYMBOL(__cond_resched_lock); |
1da177e4 | 5632 | |
613afbf8 | 5633 | int __sched __cond_resched_softirq(void) |
1da177e4 LT |
5634 | { |
5635 | BUG_ON(!in_softirq()); | |
5636 | ||
d86ee480 | 5637 | if (should_resched()) { |
98d82567 | 5638 | local_bh_enable(); |
1da177e4 LT |
5639 | __cond_resched(); |
5640 | local_bh_disable(); | |
5641 | return 1; | |
5642 | } | |
5643 | return 0; | |
5644 | } | |
613afbf8 | 5645 | EXPORT_SYMBOL(__cond_resched_softirq); |
1da177e4 | 5646 | |
1da177e4 LT |
5647 | /** |
5648 | * yield - yield the current processor to other threads. | |
5649 | * | |
72fd4a35 | 5650 | * This is a shortcut for kernel-space yielding - it marks the |
1da177e4 LT |
5651 | * thread runnable and calls sys_sched_yield(). |
5652 | */ | |
5653 | void __sched yield(void) | |
5654 | { | |
5655 | set_current_state(TASK_RUNNING); | |
5656 | sys_sched_yield(); | |
5657 | } | |
1da177e4 LT |
5658 | EXPORT_SYMBOL(yield); |
5659 | ||
d95f4122 MG |
5660 | /** |
5661 | * yield_to - yield the current processor to another thread in | |
5662 | * your thread group, or accelerate that thread toward the | |
5663 | * processor it's on. | |
16addf95 RD |
5664 | * @p: target task |
5665 | * @preempt: whether task preemption is allowed or not | |
d95f4122 MG |
5666 | * |
5667 | * It's the caller's job to ensure that the target task struct | |
5668 | * can't go away on us before we can do any checks. | |
5669 | * | |
5670 | * Returns true if we indeed boosted the target task. | |
5671 | */ | |
5672 | bool __sched yield_to(struct task_struct *p, bool preempt) | |
5673 | { | |
5674 | struct task_struct *curr = current; | |
5675 | struct rq *rq, *p_rq; | |
5676 | unsigned long flags; | |
5677 | bool yielded = 0; | |
5678 | ||
5679 | local_irq_save(flags); | |
5680 | rq = this_rq(); | |
5681 | ||
5682 | again: | |
5683 | p_rq = task_rq(p); | |
5684 | double_rq_lock(rq, p_rq); | |
5685 | while (task_rq(p) != p_rq) { | |
5686 | double_rq_unlock(rq, p_rq); | |
5687 | goto again; | |
5688 | } | |
5689 | ||
5690 | if (!curr->sched_class->yield_to_task) | |
5691 | goto out; | |
5692 | ||
5693 | if (curr->sched_class != p->sched_class) | |
5694 | goto out; | |
5695 | ||
5696 | if (task_running(p_rq, p) || p->state) | |
5697 | goto out; | |
5698 | ||
5699 | yielded = curr->sched_class->yield_to_task(rq, p, preempt); | |
6d1cafd8 | 5700 | if (yielded) { |
d95f4122 | 5701 | schedstat_inc(rq, yld_count); |
6d1cafd8 VP |
5702 | /* |
5703 | * Make p's CPU reschedule; pick_next_entity takes care of | |
5704 | * fairness. | |
5705 | */ | |
5706 | if (preempt && rq != p_rq) | |
5707 | resched_task(p_rq->curr); | |
5708 | } | |
d95f4122 MG |
5709 | |
5710 | out: | |
5711 | double_rq_unlock(rq, p_rq); | |
5712 | local_irq_restore(flags); | |
5713 | ||
5714 | if (yielded) | |
5715 | schedule(); | |
5716 | ||
5717 | return yielded; | |
5718 | } | |
5719 | EXPORT_SYMBOL_GPL(yield_to); | |
5720 | ||
1da177e4 | 5721 | /* |
41a2d6cf | 5722 | * This task is about to go to sleep on IO. Increment rq->nr_iowait so |
1da177e4 | 5723 | * that process accounting knows that this is a task in IO wait state. |
1da177e4 LT |
5724 | */ |
5725 | void __sched io_schedule(void) | |
5726 | { | |
54d35f29 | 5727 | struct rq *rq = raw_rq(); |
1da177e4 | 5728 | |
0ff92245 | 5729 | delayacct_blkio_start(); |
1da177e4 | 5730 | atomic_inc(&rq->nr_iowait); |
73c10101 | 5731 | blk_flush_plug(current); |
8f0dfc34 | 5732 | current->in_iowait = 1; |
1da177e4 | 5733 | schedule(); |
8f0dfc34 | 5734 | current->in_iowait = 0; |
1da177e4 | 5735 | atomic_dec(&rq->nr_iowait); |
0ff92245 | 5736 | delayacct_blkio_end(); |
1da177e4 | 5737 | } |
1da177e4 LT |
5738 | EXPORT_SYMBOL(io_schedule); |
5739 | ||
5740 | long __sched io_schedule_timeout(long timeout) | |
5741 | { | |
54d35f29 | 5742 | struct rq *rq = raw_rq(); |
1da177e4 LT |
5743 | long ret; |
5744 | ||
0ff92245 | 5745 | delayacct_blkio_start(); |
1da177e4 | 5746 | atomic_inc(&rq->nr_iowait); |
73c10101 | 5747 | blk_flush_plug(current); |
8f0dfc34 | 5748 | current->in_iowait = 1; |
1da177e4 | 5749 | ret = schedule_timeout(timeout); |
8f0dfc34 | 5750 | current->in_iowait = 0; |
1da177e4 | 5751 | atomic_dec(&rq->nr_iowait); |
0ff92245 | 5752 | delayacct_blkio_end(); |
1da177e4 LT |
5753 | return ret; |
5754 | } | |
5755 | ||
5756 | /** | |
5757 | * sys_sched_get_priority_max - return maximum RT priority. | |
5758 | * @policy: scheduling class. | |
5759 | * | |
5760 | * this syscall returns the maximum rt_priority that can be used | |
5761 | * by a given scheduling class. | |
5762 | */ | |
5add95d4 | 5763 | SYSCALL_DEFINE1(sched_get_priority_max, int, policy) |
1da177e4 LT |
5764 | { |
5765 | int ret = -EINVAL; | |
5766 | ||
5767 | switch (policy) { | |
5768 | case SCHED_FIFO: | |
5769 | case SCHED_RR: | |
5770 | ret = MAX_USER_RT_PRIO-1; | |
5771 | break; | |
5772 | case SCHED_NORMAL: | |
b0a9499c | 5773 | case SCHED_BATCH: |
dd41f596 | 5774 | case SCHED_IDLE: |
1da177e4 LT |
5775 | ret = 0; |
5776 | break; | |
5777 | } | |
5778 | return ret; | |
5779 | } | |
5780 | ||
5781 | /** | |
5782 | * sys_sched_get_priority_min - return minimum RT priority. | |
5783 | * @policy: scheduling class. | |
5784 | * | |
5785 | * this syscall returns the minimum rt_priority that can be used | |
5786 | * by a given scheduling class. | |
5787 | */ | |
5add95d4 | 5788 | SYSCALL_DEFINE1(sched_get_priority_min, int, policy) |
1da177e4 LT |
5789 | { |
5790 | int ret = -EINVAL; | |
5791 | ||
5792 | switch (policy) { | |
5793 | case SCHED_FIFO: | |
5794 | case SCHED_RR: | |
5795 | ret = 1; | |
5796 | break; | |
5797 | case SCHED_NORMAL: | |
b0a9499c | 5798 | case SCHED_BATCH: |
dd41f596 | 5799 | case SCHED_IDLE: |
1da177e4 LT |
5800 | ret = 0; |
5801 | } | |
5802 | return ret; | |
5803 | } | |
5804 | ||
5805 | /** | |
5806 | * sys_sched_rr_get_interval - return the default timeslice of a process. | |
5807 | * @pid: pid of the process. | |
5808 | * @interval: userspace pointer to the timeslice value. | |
5809 | * | |
5810 | * this syscall writes the default timeslice value of a given process | |
5811 | * into the user-space timespec buffer. A value of '0' means infinity. | |
5812 | */ | |
17da2bd9 | 5813 | SYSCALL_DEFINE2(sched_rr_get_interval, pid_t, pid, |
754fe8d2 | 5814 | struct timespec __user *, interval) |
1da177e4 | 5815 | { |
36c8b586 | 5816 | struct task_struct *p; |
a4ec24b4 | 5817 | unsigned int time_slice; |
dba091b9 TG |
5818 | unsigned long flags; |
5819 | struct rq *rq; | |
3a5c359a | 5820 | int retval; |
1da177e4 | 5821 | struct timespec t; |
1da177e4 LT |
5822 | |
5823 | if (pid < 0) | |
3a5c359a | 5824 | return -EINVAL; |
1da177e4 LT |
5825 | |
5826 | retval = -ESRCH; | |
1a551ae7 | 5827 | rcu_read_lock(); |
1da177e4 LT |
5828 | p = find_process_by_pid(pid); |
5829 | if (!p) | |
5830 | goto out_unlock; | |
5831 | ||
5832 | retval = security_task_getscheduler(p); | |
5833 | if (retval) | |
5834 | goto out_unlock; | |
5835 | ||
dba091b9 TG |
5836 | rq = task_rq_lock(p, &flags); |
5837 | time_slice = p->sched_class->get_rr_interval(rq, p); | |
0122ec5b | 5838 | task_rq_unlock(rq, p, &flags); |
a4ec24b4 | 5839 | |
1a551ae7 | 5840 | rcu_read_unlock(); |
a4ec24b4 | 5841 | jiffies_to_timespec(time_slice, &t); |
1da177e4 | 5842 | retval = copy_to_user(interval, &t, sizeof(t)) ? -EFAULT : 0; |
1da177e4 | 5843 | return retval; |
3a5c359a | 5844 | |
1da177e4 | 5845 | out_unlock: |
1a551ae7 | 5846 | rcu_read_unlock(); |
1da177e4 LT |
5847 | return retval; |
5848 | } | |
5849 | ||
7c731e0a | 5850 | static const char stat_nam[] = TASK_STATE_TO_CHAR_STR; |
36c8b586 | 5851 | |
82a1fcb9 | 5852 | void sched_show_task(struct task_struct *p) |
1da177e4 | 5853 | { |
1da177e4 | 5854 | unsigned long free = 0; |
36c8b586 | 5855 | unsigned state; |
1da177e4 | 5856 | |
1da177e4 | 5857 | state = p->state ? __ffs(p->state) + 1 : 0; |
28d0686c | 5858 | printk(KERN_INFO "%-15.15s %c", p->comm, |
2ed6e34f | 5859 | state < sizeof(stat_nam) - 1 ? stat_nam[state] : '?'); |
4bd77321 | 5860 | #if BITS_PER_LONG == 32 |
1da177e4 | 5861 | if (state == TASK_RUNNING) |
3df0fc5b | 5862 | printk(KERN_CONT " running "); |
1da177e4 | 5863 | else |
3df0fc5b | 5864 | printk(KERN_CONT " %08lx ", thread_saved_pc(p)); |
1da177e4 LT |
5865 | #else |
5866 | if (state == TASK_RUNNING) | |
3df0fc5b | 5867 | printk(KERN_CONT " running task "); |
1da177e4 | 5868 | else |
3df0fc5b | 5869 | printk(KERN_CONT " %016lx ", thread_saved_pc(p)); |
1da177e4 LT |
5870 | #endif |
5871 | #ifdef CONFIG_DEBUG_STACK_USAGE | |
7c9f8861 | 5872 | free = stack_not_used(p); |
1da177e4 | 5873 | #endif |
3df0fc5b | 5874 | printk(KERN_CONT "%5lu %5d %6d 0x%08lx\n", free, |
aa47b7e0 DR |
5875 | task_pid_nr(p), task_pid_nr(p->real_parent), |
5876 | (unsigned long)task_thread_info(p)->flags); | |
1da177e4 | 5877 | |
5fb5e6de | 5878 | show_stack(p, NULL); |
1da177e4 LT |
5879 | } |
5880 | ||
e59e2ae2 | 5881 | void show_state_filter(unsigned long state_filter) |
1da177e4 | 5882 | { |
36c8b586 | 5883 | struct task_struct *g, *p; |
1da177e4 | 5884 | |
4bd77321 | 5885 | #if BITS_PER_LONG == 32 |
3df0fc5b PZ |
5886 | printk(KERN_INFO |
5887 | " task PC stack pid father\n"); | |
1da177e4 | 5888 | #else |
3df0fc5b PZ |
5889 | printk(KERN_INFO |
5890 | " task PC stack pid father\n"); | |
1da177e4 LT |
5891 | #endif |
5892 | read_lock(&tasklist_lock); | |
5893 | do_each_thread(g, p) { | |
5894 | /* | |
5895 | * reset the NMI-timeout, listing all files on a slow | |
25985edc | 5896 | * console might take a lot of time: |
1da177e4 LT |
5897 | */ |
5898 | touch_nmi_watchdog(); | |
39bc89fd | 5899 | if (!state_filter || (p->state & state_filter)) |
82a1fcb9 | 5900 | sched_show_task(p); |
1da177e4 LT |
5901 | } while_each_thread(g, p); |
5902 | ||
04c9167f JF |
5903 | touch_all_softlockup_watchdogs(); |
5904 | ||
dd41f596 IM |
5905 | #ifdef CONFIG_SCHED_DEBUG |
5906 | sysrq_sched_debug_show(); | |
5907 | #endif | |
1da177e4 | 5908 | read_unlock(&tasklist_lock); |
e59e2ae2 IM |
5909 | /* |
5910 | * Only show locks if all tasks are dumped: | |
5911 | */ | |
93335a21 | 5912 | if (!state_filter) |
e59e2ae2 | 5913 | debug_show_all_locks(); |
1da177e4 LT |
5914 | } |
5915 | ||
1df21055 IM |
5916 | void __cpuinit init_idle_bootup_task(struct task_struct *idle) |
5917 | { | |
dd41f596 | 5918 | idle->sched_class = &idle_sched_class; |
1df21055 IM |
5919 | } |
5920 | ||
f340c0d1 IM |
5921 | /** |
5922 | * init_idle - set up an idle thread for a given CPU | |
5923 | * @idle: task in question | |
5924 | * @cpu: cpu the idle task belongs to | |
5925 | * | |
5926 | * NOTE: this function does not set the idle thread's NEED_RESCHED | |
5927 | * flag, to make booting more robust. | |
5928 | */ | |
5c1e1767 | 5929 | void __cpuinit init_idle(struct task_struct *idle, int cpu) |
1da177e4 | 5930 | { |
70b97a7f | 5931 | struct rq *rq = cpu_rq(cpu); |
1da177e4 LT |
5932 | unsigned long flags; |
5933 | ||
05fa785c | 5934 | raw_spin_lock_irqsave(&rq->lock, flags); |
5cbd54ef | 5935 | |
dd41f596 | 5936 | __sched_fork(idle); |
06b83b5f | 5937 | idle->state = TASK_RUNNING; |
dd41f596 IM |
5938 | idle->se.exec_start = sched_clock(); |
5939 | ||
1e1b6c51 | 5940 | do_set_cpus_allowed(idle, cpumask_of(cpu)); |
6506cf6c PZ |
5941 | /* |
5942 | * We're having a chicken and egg problem, even though we are | |
5943 | * holding rq->lock, the cpu isn't yet set to this cpu so the | |
5944 | * lockdep check in task_group() will fail. | |
5945 | * | |
5946 | * Similar case to sched_fork(). / Alternatively we could | |
5947 | * use task_rq_lock() here and obtain the other rq->lock. | |
5948 | * | |
5949 | * Silence PROVE_RCU | |
5950 | */ | |
5951 | rcu_read_lock(); | |
dd41f596 | 5952 | __set_task_cpu(idle, cpu); |
6506cf6c | 5953 | rcu_read_unlock(); |
1da177e4 | 5954 | |
1da177e4 | 5955 | rq->curr = rq->idle = idle; |
3ca7a440 PZ |
5956 | #if defined(CONFIG_SMP) |
5957 | idle->on_cpu = 1; | |
4866cde0 | 5958 | #endif |
05fa785c | 5959 | raw_spin_unlock_irqrestore(&rq->lock, flags); |
1da177e4 LT |
5960 | |
5961 | /* Set the preempt count _outside_ the spinlocks! */ | |
a1261f54 | 5962 | task_thread_info(idle)->preempt_count = 0; |
625f2a37 | 5963 | |
dd41f596 IM |
5964 | /* |
5965 | * The idle tasks have their own, simple scheduling class: | |
5966 | */ | |
5967 | idle->sched_class = &idle_sched_class; | |
868baf07 | 5968 | ftrace_graph_init_idle_task(idle, cpu); |
1da177e4 LT |
5969 | } |
5970 | ||
5971 | /* | |
5972 | * In a system that switches off the HZ timer nohz_cpu_mask | |
5973 | * indicates which cpus entered this state. This is used | |
5974 | * in the rcu update to wait only for active cpus. For system | |
5975 | * which do not switch off the HZ timer nohz_cpu_mask should | |
6a7b3dc3 | 5976 | * always be CPU_BITS_NONE. |
1da177e4 | 5977 | */ |
6a7b3dc3 | 5978 | cpumask_var_t nohz_cpu_mask; |
1da177e4 | 5979 | |
19978ca6 IM |
5980 | /* |
5981 | * Increase the granularity value when there are more CPUs, | |
5982 | * because with more CPUs the 'effective latency' as visible | |
5983 | * to users decreases. But the relationship is not linear, | |
5984 | * so pick a second-best guess by going with the log2 of the | |
5985 | * number of CPUs. | |
5986 | * | |
5987 | * This idea comes from the SD scheduler of Con Kolivas: | |
5988 | */ | |
acb4a848 | 5989 | static int get_update_sysctl_factor(void) |
19978ca6 | 5990 | { |
4ca3ef71 | 5991 | unsigned int cpus = min_t(int, num_online_cpus(), 8); |
1983a922 CE |
5992 | unsigned int factor; |
5993 | ||
5994 | switch (sysctl_sched_tunable_scaling) { | |
5995 | case SCHED_TUNABLESCALING_NONE: | |
5996 | factor = 1; | |
5997 | break; | |
5998 | case SCHED_TUNABLESCALING_LINEAR: | |
5999 | factor = cpus; | |
6000 | break; | |
6001 | case SCHED_TUNABLESCALING_LOG: | |
6002 | default: | |
6003 | factor = 1 + ilog2(cpus); | |
6004 | break; | |
6005 | } | |
19978ca6 | 6006 | |
acb4a848 CE |
6007 | return factor; |
6008 | } | |
19978ca6 | 6009 | |
acb4a848 CE |
6010 | static void update_sysctl(void) |
6011 | { | |
6012 | unsigned int factor = get_update_sysctl_factor(); | |
19978ca6 | 6013 | |
0bcdcf28 CE |
6014 | #define SET_SYSCTL(name) \ |
6015 | (sysctl_##name = (factor) * normalized_sysctl_##name) | |
6016 | SET_SYSCTL(sched_min_granularity); | |
6017 | SET_SYSCTL(sched_latency); | |
6018 | SET_SYSCTL(sched_wakeup_granularity); | |
0bcdcf28 CE |
6019 | #undef SET_SYSCTL |
6020 | } | |
55cd5340 | 6021 | |
0bcdcf28 CE |
6022 | static inline void sched_init_granularity(void) |
6023 | { | |
6024 | update_sysctl(); | |
19978ca6 IM |
6025 | } |
6026 | ||
1da177e4 | 6027 | #ifdef CONFIG_SMP |
1e1b6c51 KM |
6028 | void do_set_cpus_allowed(struct task_struct *p, const struct cpumask *new_mask) |
6029 | { | |
6030 | if (p->sched_class && p->sched_class->set_cpus_allowed) | |
6031 | p->sched_class->set_cpus_allowed(p, new_mask); | |
6032 | else { | |
6033 | cpumask_copy(&p->cpus_allowed, new_mask); | |
6034 | p->rt.nr_cpus_allowed = cpumask_weight(new_mask); | |
6035 | } | |
6036 | } | |
6037 | ||
1da177e4 LT |
6038 | /* |
6039 | * This is how migration works: | |
6040 | * | |
969c7921 TH |
6041 | * 1) we invoke migration_cpu_stop() on the target CPU using |
6042 | * stop_one_cpu(). | |
6043 | * 2) stopper starts to run (implicitly forcing the migrated thread | |
6044 | * off the CPU) | |
6045 | * 3) it checks whether the migrated task is still in the wrong runqueue. | |
6046 | * 4) if it's in the wrong runqueue then the migration thread removes | |
1da177e4 | 6047 | * it and puts it into the right queue. |
969c7921 TH |
6048 | * 5) stopper completes and stop_one_cpu() returns and the migration |
6049 | * is done. | |
1da177e4 LT |
6050 | */ |
6051 | ||
6052 | /* | |
6053 | * Change a given task's CPU affinity. Migrate the thread to a | |
6054 | * proper CPU and schedule it away if the CPU it's executing on | |
6055 | * is removed from the allowed bitmask. | |
6056 | * | |
6057 | * NOTE: the caller must have a valid reference to the task, the | |
41a2d6cf | 6058 | * task must not exit() & deallocate itself prematurely. The |
1da177e4 LT |
6059 | * call is not atomic; no spinlocks may be held. |
6060 | */ | |
96f874e2 | 6061 | int set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask) |
1da177e4 LT |
6062 | { |
6063 | unsigned long flags; | |
70b97a7f | 6064 | struct rq *rq; |
969c7921 | 6065 | unsigned int dest_cpu; |
48f24c4d | 6066 | int ret = 0; |
1da177e4 LT |
6067 | |
6068 | rq = task_rq_lock(p, &flags); | |
e2912009 | 6069 | |
db44fc01 YZ |
6070 | if (cpumask_equal(&p->cpus_allowed, new_mask)) |
6071 | goto out; | |
6072 | ||
6ad4c188 | 6073 | if (!cpumask_intersects(new_mask, cpu_active_mask)) { |
1da177e4 LT |
6074 | ret = -EINVAL; |
6075 | goto out; | |
6076 | } | |
6077 | ||
db44fc01 | 6078 | if (unlikely((p->flags & PF_THREAD_BOUND) && p != current)) { |
9985b0ba DR |
6079 | ret = -EINVAL; |
6080 | goto out; | |
6081 | } | |
6082 | ||
1e1b6c51 | 6083 | do_set_cpus_allowed(p, new_mask); |
73fe6aae | 6084 | |
1da177e4 | 6085 | /* Can the task run on the task's current CPU? If so, we're done */ |
96f874e2 | 6086 | if (cpumask_test_cpu(task_cpu(p), new_mask)) |
1da177e4 LT |
6087 | goto out; |
6088 | ||
969c7921 | 6089 | dest_cpu = cpumask_any_and(cpu_active_mask, new_mask); |
bd8e7dde | 6090 | if (p->on_rq) { |
969c7921 | 6091 | struct migration_arg arg = { p, dest_cpu }; |
1da177e4 | 6092 | /* Need help from migration thread: drop lock and wait. */ |
0122ec5b | 6093 | task_rq_unlock(rq, p, &flags); |
969c7921 | 6094 | stop_one_cpu(cpu_of(rq), migration_cpu_stop, &arg); |
1da177e4 LT |
6095 | tlb_migrate_finish(p->mm); |
6096 | return 0; | |
6097 | } | |
6098 | out: | |
0122ec5b | 6099 | task_rq_unlock(rq, p, &flags); |
48f24c4d | 6100 | |
1da177e4 LT |
6101 | return ret; |
6102 | } | |
cd8ba7cd | 6103 | EXPORT_SYMBOL_GPL(set_cpus_allowed_ptr); |
1da177e4 LT |
6104 | |
6105 | /* | |
41a2d6cf | 6106 | * Move (not current) task off this cpu, onto dest cpu. We're doing |
1da177e4 LT |
6107 | * this because either it can't run here any more (set_cpus_allowed() |
6108 | * away from this CPU, or CPU going down), or because we're | |
6109 | * attempting to rebalance this task on exec (sched_exec). | |
6110 | * | |
6111 | * So we race with normal scheduler movements, but that's OK, as long | |
6112 | * as the task is no longer on this CPU. | |
efc30814 KK |
6113 | * |
6114 | * Returns non-zero if task was successfully migrated. | |
1da177e4 | 6115 | */ |
efc30814 | 6116 | static int __migrate_task(struct task_struct *p, int src_cpu, int dest_cpu) |
1da177e4 | 6117 | { |
70b97a7f | 6118 | struct rq *rq_dest, *rq_src; |
e2912009 | 6119 | int ret = 0; |
1da177e4 | 6120 | |
e761b772 | 6121 | if (unlikely(!cpu_active(dest_cpu))) |
efc30814 | 6122 | return ret; |
1da177e4 LT |
6123 | |
6124 | rq_src = cpu_rq(src_cpu); | |
6125 | rq_dest = cpu_rq(dest_cpu); | |
6126 | ||
0122ec5b | 6127 | raw_spin_lock(&p->pi_lock); |
1da177e4 LT |
6128 | double_rq_lock(rq_src, rq_dest); |
6129 | /* Already moved. */ | |
6130 | if (task_cpu(p) != src_cpu) | |
b1e38734 | 6131 | goto done; |
1da177e4 | 6132 | /* Affinity changed (again). */ |
96f874e2 | 6133 | if (!cpumask_test_cpu(dest_cpu, &p->cpus_allowed)) |
b1e38734 | 6134 | goto fail; |
1da177e4 | 6135 | |
e2912009 PZ |
6136 | /* |
6137 | * If we're not on a rq, the next wake-up will ensure we're | |
6138 | * placed properly. | |
6139 | */ | |
fd2f4419 | 6140 | if (p->on_rq) { |
2e1cb74a | 6141 | deactivate_task(rq_src, p, 0); |
e2912009 | 6142 | set_task_cpu(p, dest_cpu); |
dd41f596 | 6143 | activate_task(rq_dest, p, 0); |
15afe09b | 6144 | check_preempt_curr(rq_dest, p, 0); |
1da177e4 | 6145 | } |
b1e38734 | 6146 | done: |
efc30814 | 6147 | ret = 1; |
b1e38734 | 6148 | fail: |
1da177e4 | 6149 | double_rq_unlock(rq_src, rq_dest); |
0122ec5b | 6150 | raw_spin_unlock(&p->pi_lock); |
efc30814 | 6151 | return ret; |
1da177e4 LT |
6152 | } |
6153 | ||
6154 | /* | |
969c7921 TH |
6155 | * migration_cpu_stop - this will be executed by a highprio stopper thread |
6156 | * and performs thread migration by bumping thread off CPU then | |
6157 | * 'pushing' onto another runqueue. | |
1da177e4 | 6158 | */ |
969c7921 | 6159 | static int migration_cpu_stop(void *data) |
1da177e4 | 6160 | { |
969c7921 | 6161 | struct migration_arg *arg = data; |
f7b4cddc | 6162 | |
969c7921 TH |
6163 | /* |
6164 | * The original target cpu might have gone down and we might | |
6165 | * be on another cpu but it doesn't matter. | |
6166 | */ | |
f7b4cddc | 6167 | local_irq_disable(); |
969c7921 | 6168 | __migrate_task(arg->task, raw_smp_processor_id(), arg->dest_cpu); |
f7b4cddc | 6169 | local_irq_enable(); |
1da177e4 | 6170 | return 0; |
f7b4cddc ON |
6171 | } |
6172 | ||
1da177e4 | 6173 | #ifdef CONFIG_HOTPLUG_CPU |
48c5ccae | 6174 | |
054b9108 | 6175 | /* |
48c5ccae PZ |
6176 | * Ensures that the idle task is using init_mm right before its cpu goes |
6177 | * offline. | |
054b9108 | 6178 | */ |
48c5ccae | 6179 | void idle_task_exit(void) |
1da177e4 | 6180 | { |
48c5ccae | 6181 | struct mm_struct *mm = current->active_mm; |
e76bd8d9 | 6182 | |
48c5ccae | 6183 | BUG_ON(cpu_online(smp_processor_id())); |
e76bd8d9 | 6184 | |
48c5ccae PZ |
6185 | if (mm != &init_mm) |
6186 | switch_mm(mm, &init_mm, current); | |
6187 | mmdrop(mm); | |
1da177e4 LT |
6188 | } |
6189 | ||
6190 | /* | |
6191 | * While a dead CPU has no uninterruptible tasks queued at this point, | |
6192 | * it might still have a nonzero ->nr_uninterruptible counter, because | |
6193 | * for performance reasons the counter is not stricly tracking tasks to | |
6194 | * their home CPUs. So we just add the counter to another CPU's counter, | |
6195 | * to keep the global sum constant after CPU-down: | |
6196 | */ | |
70b97a7f | 6197 | static void migrate_nr_uninterruptible(struct rq *rq_src) |
1da177e4 | 6198 | { |
6ad4c188 | 6199 | struct rq *rq_dest = cpu_rq(cpumask_any(cpu_active_mask)); |
1da177e4 | 6200 | |
1da177e4 LT |
6201 | rq_dest->nr_uninterruptible += rq_src->nr_uninterruptible; |
6202 | rq_src->nr_uninterruptible = 0; | |
1da177e4 LT |
6203 | } |
6204 | ||
dd41f596 | 6205 | /* |
48c5ccae | 6206 | * remove the tasks which were accounted by rq from calc_load_tasks. |
1da177e4 | 6207 | */ |
48c5ccae | 6208 | static void calc_global_load_remove(struct rq *rq) |
1da177e4 | 6209 | { |
48c5ccae PZ |
6210 | atomic_long_sub(rq->calc_load_active, &calc_load_tasks); |
6211 | rq->calc_load_active = 0; | |
1da177e4 LT |
6212 | } |
6213 | ||
48f24c4d | 6214 | /* |
48c5ccae PZ |
6215 | * Migrate all tasks from the rq, sleeping tasks will be migrated by |
6216 | * try_to_wake_up()->select_task_rq(). | |
6217 | * | |
6218 | * Called with rq->lock held even though we'er in stop_machine() and | |
6219 | * there's no concurrency possible, we hold the required locks anyway | |
6220 | * because of lock validation efforts. | |
1da177e4 | 6221 | */ |
48c5ccae | 6222 | static void migrate_tasks(unsigned int dead_cpu) |
1da177e4 | 6223 | { |
70b97a7f | 6224 | struct rq *rq = cpu_rq(dead_cpu); |
48c5ccae PZ |
6225 | struct task_struct *next, *stop = rq->stop; |
6226 | int dest_cpu; | |
1da177e4 LT |
6227 | |
6228 | /* | |
48c5ccae PZ |
6229 | * Fudge the rq selection such that the below task selection loop |
6230 | * doesn't get stuck on the currently eligible stop task. | |
6231 | * | |
6232 | * We're currently inside stop_machine() and the rq is either stuck | |
6233 | * in the stop_machine_cpu_stop() loop, or we're executing this code, | |
6234 | * either way we should never end up calling schedule() until we're | |
6235 | * done here. | |
1da177e4 | 6236 | */ |
48c5ccae | 6237 | rq->stop = NULL; |
48f24c4d | 6238 | |
dd41f596 | 6239 | for ( ; ; ) { |
48c5ccae PZ |
6240 | /* |
6241 | * There's this thread running, bail when that's the only | |
6242 | * remaining thread. | |
6243 | */ | |
6244 | if (rq->nr_running == 1) | |
dd41f596 | 6245 | break; |
48c5ccae | 6246 | |
b67802ea | 6247 | next = pick_next_task(rq); |
48c5ccae | 6248 | BUG_ON(!next); |
79c53799 | 6249 | next->sched_class->put_prev_task(rq, next); |
e692ab53 | 6250 | |
48c5ccae PZ |
6251 | /* Find suitable destination for @next, with force if needed. */ |
6252 | dest_cpu = select_fallback_rq(dead_cpu, next); | |
6253 | raw_spin_unlock(&rq->lock); | |
6254 | ||
6255 | __migrate_task(next, dead_cpu, dest_cpu); | |
6256 | ||
6257 | raw_spin_lock(&rq->lock); | |
1da177e4 | 6258 | } |
dce48a84 | 6259 | |
48c5ccae | 6260 | rq->stop = stop; |
dce48a84 | 6261 | } |
48c5ccae | 6262 | |
1da177e4 LT |
6263 | #endif /* CONFIG_HOTPLUG_CPU */ |
6264 | ||
e692ab53 NP |
6265 | #if defined(CONFIG_SCHED_DEBUG) && defined(CONFIG_SYSCTL) |
6266 | ||
6267 | static struct ctl_table sd_ctl_dir[] = { | |
e0361851 AD |
6268 | { |
6269 | .procname = "sched_domain", | |
c57baf1e | 6270 | .mode = 0555, |
e0361851 | 6271 | }, |
56992309 | 6272 | {} |
e692ab53 NP |
6273 | }; |
6274 | ||
6275 | static struct ctl_table sd_ctl_root[] = { | |
e0361851 AD |
6276 | { |
6277 | .procname = "kernel", | |
c57baf1e | 6278 | .mode = 0555, |
e0361851 AD |
6279 | .child = sd_ctl_dir, |
6280 | }, | |
56992309 | 6281 | {} |
e692ab53 NP |
6282 | }; |
6283 | ||
6284 | static struct ctl_table *sd_alloc_ctl_entry(int n) | |
6285 | { | |
6286 | struct ctl_table *entry = | |
5cf9f062 | 6287 | kcalloc(n, sizeof(struct ctl_table), GFP_KERNEL); |
e692ab53 | 6288 | |
e692ab53 NP |
6289 | return entry; |
6290 | } | |
6291 | ||
6382bc90 MM |
6292 | static void sd_free_ctl_entry(struct ctl_table **tablep) |
6293 | { | |
cd790076 | 6294 | struct ctl_table *entry; |
6382bc90 | 6295 | |
cd790076 MM |
6296 | /* |
6297 | * In the intermediate directories, both the child directory and | |
6298 | * procname are dynamically allocated and could fail but the mode | |
41a2d6cf | 6299 | * will always be set. In the lowest directory the names are |
cd790076 MM |
6300 | * static strings and all have proc handlers. |
6301 | */ | |
6302 | for (entry = *tablep; entry->mode; entry++) { | |
6382bc90 MM |
6303 | if (entry->child) |
6304 | sd_free_ctl_entry(&entry->child); | |
cd790076 MM |
6305 | if (entry->proc_handler == NULL) |
6306 | kfree(entry->procname); | |
6307 | } | |
6382bc90 MM |
6308 | |
6309 | kfree(*tablep); | |
6310 | *tablep = NULL; | |
6311 | } | |
6312 | ||
e692ab53 | 6313 | static void |
e0361851 | 6314 | set_table_entry(struct ctl_table *entry, |
e692ab53 NP |
6315 | const char *procname, void *data, int maxlen, |
6316 | mode_t mode, proc_handler *proc_handler) | |
6317 | { | |
e692ab53 NP |
6318 | entry->procname = procname; |
6319 | entry->data = data; | |
6320 | entry->maxlen = maxlen; | |
6321 | entry->mode = mode; | |
6322 | entry->proc_handler = proc_handler; | |
6323 | } | |
6324 | ||
6325 | static struct ctl_table * | |
6326 | sd_alloc_ctl_domain_table(struct sched_domain *sd) | |
6327 | { | |
a5d8c348 | 6328 | struct ctl_table *table = sd_alloc_ctl_entry(13); |
e692ab53 | 6329 | |
ad1cdc1d MM |
6330 | if (table == NULL) |
6331 | return NULL; | |
6332 | ||
e0361851 | 6333 | set_table_entry(&table[0], "min_interval", &sd->min_interval, |
e692ab53 | 6334 | sizeof(long), 0644, proc_doulongvec_minmax); |
e0361851 | 6335 | set_table_entry(&table[1], "max_interval", &sd->max_interval, |
e692ab53 | 6336 | sizeof(long), 0644, proc_doulongvec_minmax); |
e0361851 | 6337 | set_table_entry(&table[2], "busy_idx", &sd->busy_idx, |
e692ab53 | 6338 | sizeof(int), 0644, proc_dointvec_minmax); |
e0361851 | 6339 | set_table_entry(&table[3], "idle_idx", &sd->idle_idx, |
e692ab53 | 6340 | sizeof(int), 0644, proc_dointvec_minmax); |
e0361851 | 6341 | set_table_entry(&table[4], "newidle_idx", &sd->newidle_idx, |
e692ab53 | 6342 | sizeof(int), 0644, proc_dointvec_minmax); |
e0361851 | 6343 | set_table_entry(&table[5], "wake_idx", &sd->wake_idx, |
e692ab53 | 6344 | sizeof(int), 0644, proc_dointvec_minmax); |
e0361851 | 6345 | set_table_entry(&table[6], "forkexec_idx", &sd->forkexec_idx, |
e692ab53 | 6346 | sizeof(int), 0644, proc_dointvec_minmax); |
e0361851 | 6347 | set_table_entry(&table[7], "busy_factor", &sd->busy_factor, |
e692ab53 | 6348 | sizeof(int), 0644, proc_dointvec_minmax); |
e0361851 | 6349 | set_table_entry(&table[8], "imbalance_pct", &sd->imbalance_pct, |
e692ab53 | 6350 | sizeof(int), 0644, proc_dointvec_minmax); |
ace8b3d6 | 6351 | set_table_entry(&table[9], "cache_nice_tries", |
e692ab53 NP |
6352 | &sd->cache_nice_tries, |
6353 | sizeof(int), 0644, proc_dointvec_minmax); | |
ace8b3d6 | 6354 | set_table_entry(&table[10], "flags", &sd->flags, |
e692ab53 | 6355 | sizeof(int), 0644, proc_dointvec_minmax); |
a5d8c348 IM |
6356 | set_table_entry(&table[11], "name", sd->name, |
6357 | CORENAME_MAX_SIZE, 0444, proc_dostring); | |
6358 | /* &table[12] is terminator */ | |
e692ab53 NP |
6359 | |
6360 | return table; | |
6361 | } | |
6362 | ||
9a4e7159 | 6363 | static ctl_table *sd_alloc_ctl_cpu_table(int cpu) |
e692ab53 NP |
6364 | { |
6365 | struct ctl_table *entry, *table; | |
6366 | struct sched_domain *sd; | |
6367 | int domain_num = 0, i; | |
6368 | char buf[32]; | |
6369 | ||
6370 | for_each_domain(cpu, sd) | |
6371 | domain_num++; | |
6372 | entry = table = sd_alloc_ctl_entry(domain_num + 1); | |
ad1cdc1d MM |
6373 | if (table == NULL) |
6374 | return NULL; | |
e692ab53 NP |
6375 | |
6376 | i = 0; | |
6377 | for_each_domain(cpu, sd) { | |
6378 | snprintf(buf, 32, "domain%d", i); | |
e692ab53 | 6379 | entry->procname = kstrdup(buf, GFP_KERNEL); |
c57baf1e | 6380 | entry->mode = 0555; |
e692ab53 NP |
6381 | entry->child = sd_alloc_ctl_domain_table(sd); |
6382 | entry++; | |
6383 | i++; | |
6384 | } | |
6385 | return table; | |
6386 | } | |
6387 | ||
6388 | static struct ctl_table_header *sd_sysctl_header; | |
6382bc90 | 6389 | static void register_sched_domain_sysctl(void) |
e692ab53 | 6390 | { |
6ad4c188 | 6391 | int i, cpu_num = num_possible_cpus(); |
e692ab53 NP |
6392 | struct ctl_table *entry = sd_alloc_ctl_entry(cpu_num + 1); |
6393 | char buf[32]; | |
6394 | ||
7378547f MM |
6395 | WARN_ON(sd_ctl_dir[0].child); |
6396 | sd_ctl_dir[0].child = entry; | |
6397 | ||
ad1cdc1d MM |
6398 | if (entry == NULL) |
6399 | return; | |
6400 | ||
6ad4c188 | 6401 | for_each_possible_cpu(i) { |
e692ab53 | 6402 | snprintf(buf, 32, "cpu%d", i); |
e692ab53 | 6403 | entry->procname = kstrdup(buf, GFP_KERNEL); |
c57baf1e | 6404 | entry->mode = 0555; |
e692ab53 | 6405 | entry->child = sd_alloc_ctl_cpu_table(i); |
97b6ea7b | 6406 | entry++; |
e692ab53 | 6407 | } |
7378547f MM |
6408 | |
6409 | WARN_ON(sd_sysctl_header); | |
e692ab53 NP |
6410 | sd_sysctl_header = register_sysctl_table(sd_ctl_root); |
6411 | } | |
6382bc90 | 6412 | |
7378547f | 6413 | /* may be called multiple times per register */ |
6382bc90 MM |
6414 | static void unregister_sched_domain_sysctl(void) |
6415 | { | |
7378547f MM |
6416 | if (sd_sysctl_header) |
6417 | unregister_sysctl_table(sd_sysctl_header); | |
6382bc90 | 6418 | sd_sysctl_header = NULL; |
7378547f MM |
6419 | if (sd_ctl_dir[0].child) |
6420 | sd_free_ctl_entry(&sd_ctl_dir[0].child); | |
6382bc90 | 6421 | } |
e692ab53 | 6422 | #else |
6382bc90 MM |
6423 | static void register_sched_domain_sysctl(void) |
6424 | { | |
6425 | } | |
6426 | static void unregister_sched_domain_sysctl(void) | |
e692ab53 NP |
6427 | { |
6428 | } | |
6429 | #endif | |
6430 | ||
1f11eb6a GH |
6431 | static void set_rq_online(struct rq *rq) |
6432 | { | |
6433 | if (!rq->online) { | |
6434 | const struct sched_class *class; | |
6435 | ||
c6c4927b | 6436 | cpumask_set_cpu(rq->cpu, rq->rd->online); |
1f11eb6a GH |
6437 | rq->online = 1; |
6438 | ||
6439 | for_each_class(class) { | |
6440 | if (class->rq_online) | |
6441 | class->rq_online(rq); | |
6442 | } | |
6443 | } | |
6444 | } | |
6445 | ||
6446 | static void set_rq_offline(struct rq *rq) | |
6447 | { | |
6448 | if (rq->online) { | |
6449 | const struct sched_class *class; | |
6450 | ||
6451 | for_each_class(class) { | |
6452 | if (class->rq_offline) | |
6453 | class->rq_offline(rq); | |
6454 | } | |
6455 | ||
c6c4927b | 6456 | cpumask_clear_cpu(rq->cpu, rq->rd->online); |
1f11eb6a GH |
6457 | rq->online = 0; |
6458 | } | |
6459 | } | |
6460 | ||
1da177e4 LT |
6461 | /* |
6462 | * migration_call - callback that gets triggered when a CPU is added. | |
6463 | * Here we can start up the necessary migration thread for the new CPU. | |
6464 | */ | |
48f24c4d IM |
6465 | static int __cpuinit |
6466 | migration_call(struct notifier_block *nfb, unsigned long action, void *hcpu) | |
1da177e4 | 6467 | { |
48f24c4d | 6468 | int cpu = (long)hcpu; |
1da177e4 | 6469 | unsigned long flags; |
969c7921 | 6470 | struct rq *rq = cpu_rq(cpu); |
1da177e4 | 6471 | |
48c5ccae | 6472 | switch (action & ~CPU_TASKS_FROZEN) { |
5be9361c | 6473 | |
1da177e4 | 6474 | case CPU_UP_PREPARE: |
a468d389 | 6475 | rq->calc_load_update = calc_load_update; |
1da177e4 | 6476 | break; |
48f24c4d | 6477 | |
1da177e4 | 6478 | case CPU_ONLINE: |
1f94ef59 | 6479 | /* Update our root-domain */ |
05fa785c | 6480 | raw_spin_lock_irqsave(&rq->lock, flags); |
1f94ef59 | 6481 | if (rq->rd) { |
c6c4927b | 6482 | BUG_ON(!cpumask_test_cpu(cpu, rq->rd->span)); |
1f11eb6a GH |
6483 | |
6484 | set_rq_online(rq); | |
1f94ef59 | 6485 | } |
05fa785c | 6486 | raw_spin_unlock_irqrestore(&rq->lock, flags); |
1da177e4 | 6487 | break; |
48f24c4d | 6488 | |
1da177e4 | 6489 | #ifdef CONFIG_HOTPLUG_CPU |
08f503b0 | 6490 | case CPU_DYING: |
317f3941 | 6491 | sched_ttwu_pending(); |
57d885fe | 6492 | /* Update our root-domain */ |
05fa785c | 6493 | raw_spin_lock_irqsave(&rq->lock, flags); |
57d885fe | 6494 | if (rq->rd) { |
c6c4927b | 6495 | BUG_ON(!cpumask_test_cpu(cpu, rq->rd->span)); |
1f11eb6a | 6496 | set_rq_offline(rq); |
57d885fe | 6497 | } |
48c5ccae PZ |
6498 | migrate_tasks(cpu); |
6499 | BUG_ON(rq->nr_running != 1); /* the migration thread */ | |
05fa785c | 6500 | raw_spin_unlock_irqrestore(&rq->lock, flags); |
48c5ccae PZ |
6501 | |
6502 | migrate_nr_uninterruptible(rq); | |
6503 | calc_global_load_remove(rq); | |
57d885fe | 6504 | break; |
1da177e4 LT |
6505 | #endif |
6506 | } | |
49c022e6 PZ |
6507 | |
6508 | update_max_interval(); | |
6509 | ||
1da177e4 LT |
6510 | return NOTIFY_OK; |
6511 | } | |
6512 | ||
f38b0820 PM |
6513 | /* |
6514 | * Register at high priority so that task migration (migrate_all_tasks) | |
6515 | * happens before everything else. This has to be lower priority than | |
cdd6c482 | 6516 | * the notifier in the perf_event subsystem, though. |
1da177e4 | 6517 | */ |
26c2143b | 6518 | static struct notifier_block __cpuinitdata migration_notifier = { |
1da177e4 | 6519 | .notifier_call = migration_call, |
50a323b7 | 6520 | .priority = CPU_PRI_MIGRATION, |
1da177e4 LT |
6521 | }; |
6522 | ||
3a101d05 TH |
6523 | static int __cpuinit sched_cpu_active(struct notifier_block *nfb, |
6524 | unsigned long action, void *hcpu) | |
6525 | { | |
6526 | switch (action & ~CPU_TASKS_FROZEN) { | |
6527 | case CPU_ONLINE: | |
6528 | case CPU_DOWN_FAILED: | |
6529 | set_cpu_active((long)hcpu, true); | |
6530 | return NOTIFY_OK; | |
6531 | default: | |
6532 | return NOTIFY_DONE; | |
6533 | } | |
6534 | } | |
6535 | ||
6536 | static int __cpuinit sched_cpu_inactive(struct notifier_block *nfb, | |
6537 | unsigned long action, void *hcpu) | |
6538 | { | |
6539 | switch (action & ~CPU_TASKS_FROZEN) { | |
6540 | case CPU_DOWN_PREPARE: | |
6541 | set_cpu_active((long)hcpu, false); | |
6542 | return NOTIFY_OK; | |
6543 | default: | |
6544 | return NOTIFY_DONE; | |
6545 | } | |
6546 | } | |
6547 | ||
7babe8db | 6548 | static int __init migration_init(void) |
1da177e4 LT |
6549 | { |
6550 | void *cpu = (void *)(long)smp_processor_id(); | |
07dccf33 | 6551 | int err; |
48f24c4d | 6552 | |
3a101d05 | 6553 | /* Initialize migration for the boot CPU */ |
07dccf33 AM |
6554 | err = migration_call(&migration_notifier, CPU_UP_PREPARE, cpu); |
6555 | BUG_ON(err == NOTIFY_BAD); | |
1da177e4 LT |
6556 | migration_call(&migration_notifier, CPU_ONLINE, cpu); |
6557 | register_cpu_notifier(&migration_notifier); | |
7babe8db | 6558 | |
3a101d05 TH |
6559 | /* Register cpu active notifiers */ |
6560 | cpu_notifier(sched_cpu_active, CPU_PRI_SCHED_ACTIVE); | |
6561 | cpu_notifier(sched_cpu_inactive, CPU_PRI_SCHED_INACTIVE); | |
6562 | ||
a004cd42 | 6563 | return 0; |
1da177e4 | 6564 | } |
7babe8db | 6565 | early_initcall(migration_init); |
1da177e4 LT |
6566 | #endif |
6567 | ||
6568 | #ifdef CONFIG_SMP | |
476f3534 | 6569 | |
4cb98839 PZ |
6570 | static cpumask_var_t sched_domains_tmpmask; /* sched_domains_mutex */ |
6571 | ||
3e9830dc | 6572 | #ifdef CONFIG_SCHED_DEBUG |
4dcf6aff | 6573 | |
f6630114 MT |
6574 | static __read_mostly int sched_domain_debug_enabled; |
6575 | ||
6576 | static int __init sched_domain_debug_setup(char *str) | |
6577 | { | |
6578 | sched_domain_debug_enabled = 1; | |
6579 | ||
6580 | return 0; | |
6581 | } | |
6582 | early_param("sched_debug", sched_domain_debug_setup); | |
6583 | ||
7c16ec58 | 6584 | static int sched_domain_debug_one(struct sched_domain *sd, int cpu, int level, |
96f874e2 | 6585 | struct cpumask *groupmask) |
1da177e4 | 6586 | { |
4dcf6aff | 6587 | struct sched_group *group = sd->groups; |
434d53b0 | 6588 | char str[256]; |
1da177e4 | 6589 | |
968ea6d8 | 6590 | cpulist_scnprintf(str, sizeof(str), sched_domain_span(sd)); |
96f874e2 | 6591 | cpumask_clear(groupmask); |
4dcf6aff IM |
6592 | |
6593 | printk(KERN_DEBUG "%*s domain %d: ", level, "", level); | |
6594 | ||
6595 | if (!(sd->flags & SD_LOAD_BALANCE)) { | |
3df0fc5b | 6596 | printk("does not load-balance\n"); |
4dcf6aff | 6597 | if (sd->parent) |
3df0fc5b PZ |
6598 | printk(KERN_ERR "ERROR: !SD_LOAD_BALANCE domain" |
6599 | " has parent"); | |
4dcf6aff | 6600 | return -1; |
41c7ce9a NP |
6601 | } |
6602 | ||
3df0fc5b | 6603 | printk(KERN_CONT "span %s level %s\n", str, sd->name); |
4dcf6aff | 6604 | |
758b2cdc | 6605 | if (!cpumask_test_cpu(cpu, sched_domain_span(sd))) { |
3df0fc5b PZ |
6606 | printk(KERN_ERR "ERROR: domain->span does not contain " |
6607 | "CPU%d\n", cpu); | |
4dcf6aff | 6608 | } |
758b2cdc | 6609 | if (!cpumask_test_cpu(cpu, sched_group_cpus(group))) { |
3df0fc5b PZ |
6610 | printk(KERN_ERR "ERROR: domain->groups does not contain" |
6611 | " CPU%d\n", cpu); | |
4dcf6aff | 6612 | } |
1da177e4 | 6613 | |
4dcf6aff | 6614 | printk(KERN_DEBUG "%*s groups:", level + 1, ""); |
1da177e4 | 6615 | do { |
4dcf6aff | 6616 | if (!group) { |
3df0fc5b PZ |
6617 | printk("\n"); |
6618 | printk(KERN_ERR "ERROR: group is NULL\n"); | |
1da177e4 LT |
6619 | break; |
6620 | } | |
6621 | ||
9c3f75cb | 6622 | if (!group->sgp->power) { |
3df0fc5b PZ |
6623 | printk(KERN_CONT "\n"); |
6624 | printk(KERN_ERR "ERROR: domain->cpu_power not " | |
6625 | "set\n"); | |
4dcf6aff IM |
6626 | break; |
6627 | } | |
1da177e4 | 6628 | |
758b2cdc | 6629 | if (!cpumask_weight(sched_group_cpus(group))) { |
3df0fc5b PZ |
6630 | printk(KERN_CONT "\n"); |
6631 | printk(KERN_ERR "ERROR: empty group\n"); | |
4dcf6aff IM |
6632 | break; |
6633 | } | |
1da177e4 | 6634 | |
758b2cdc | 6635 | if (cpumask_intersects(groupmask, sched_group_cpus(group))) { |
3df0fc5b PZ |
6636 | printk(KERN_CONT "\n"); |
6637 | printk(KERN_ERR "ERROR: repeated CPUs\n"); | |
4dcf6aff IM |
6638 | break; |
6639 | } | |
1da177e4 | 6640 | |
758b2cdc | 6641 | cpumask_or(groupmask, groupmask, sched_group_cpus(group)); |
1da177e4 | 6642 | |
968ea6d8 | 6643 | cpulist_scnprintf(str, sizeof(str), sched_group_cpus(group)); |
381512cf | 6644 | |
3df0fc5b | 6645 | printk(KERN_CONT " %s", str); |
9c3f75cb | 6646 | if (group->sgp->power != SCHED_POWER_SCALE) { |
3df0fc5b | 6647 | printk(KERN_CONT " (cpu_power = %d)", |
9c3f75cb | 6648 | group->sgp->power); |
381512cf | 6649 | } |
1da177e4 | 6650 | |
4dcf6aff IM |
6651 | group = group->next; |
6652 | } while (group != sd->groups); | |
3df0fc5b | 6653 | printk(KERN_CONT "\n"); |
1da177e4 | 6654 | |
758b2cdc | 6655 | if (!cpumask_equal(sched_domain_span(sd), groupmask)) |
3df0fc5b | 6656 | printk(KERN_ERR "ERROR: groups don't span domain->span\n"); |
1da177e4 | 6657 | |
758b2cdc RR |
6658 | if (sd->parent && |
6659 | !cpumask_subset(groupmask, sched_domain_span(sd->parent))) | |
3df0fc5b PZ |
6660 | printk(KERN_ERR "ERROR: parent span is not a superset " |
6661 | "of domain->span\n"); | |
4dcf6aff IM |
6662 | return 0; |
6663 | } | |
1da177e4 | 6664 | |
4dcf6aff IM |
6665 | static void sched_domain_debug(struct sched_domain *sd, int cpu) |
6666 | { | |
6667 | int level = 0; | |
1da177e4 | 6668 | |
f6630114 MT |
6669 | if (!sched_domain_debug_enabled) |
6670 | return; | |
6671 | ||
4dcf6aff IM |
6672 | if (!sd) { |
6673 | printk(KERN_DEBUG "CPU%d attaching NULL sched-domain.\n", cpu); | |
6674 | return; | |
6675 | } | |
1da177e4 | 6676 | |
4dcf6aff IM |
6677 | printk(KERN_DEBUG "CPU%d attaching sched-domain:\n", cpu); |
6678 | ||
6679 | for (;;) { | |
4cb98839 | 6680 | if (sched_domain_debug_one(sd, cpu, level, sched_domains_tmpmask)) |
4dcf6aff | 6681 | break; |
1da177e4 LT |
6682 | level++; |
6683 | sd = sd->parent; | |
33859f7f | 6684 | if (!sd) |
4dcf6aff IM |
6685 | break; |
6686 | } | |
1da177e4 | 6687 | } |
6d6bc0ad | 6688 | #else /* !CONFIG_SCHED_DEBUG */ |
48f24c4d | 6689 | # define sched_domain_debug(sd, cpu) do { } while (0) |
6d6bc0ad | 6690 | #endif /* CONFIG_SCHED_DEBUG */ |
1da177e4 | 6691 | |
1a20ff27 | 6692 | static int sd_degenerate(struct sched_domain *sd) |
245af2c7 | 6693 | { |
758b2cdc | 6694 | if (cpumask_weight(sched_domain_span(sd)) == 1) |
245af2c7 SS |
6695 | return 1; |
6696 | ||
6697 | /* Following flags need at least 2 groups */ | |
6698 | if (sd->flags & (SD_LOAD_BALANCE | | |
6699 | SD_BALANCE_NEWIDLE | | |
6700 | SD_BALANCE_FORK | | |
89c4710e SS |
6701 | SD_BALANCE_EXEC | |
6702 | SD_SHARE_CPUPOWER | | |
6703 | SD_SHARE_PKG_RESOURCES)) { | |
245af2c7 SS |
6704 | if (sd->groups != sd->groups->next) |
6705 | return 0; | |
6706 | } | |
6707 | ||
6708 | /* Following flags don't use groups */ | |
c88d5910 | 6709 | if (sd->flags & (SD_WAKE_AFFINE)) |
245af2c7 SS |
6710 | return 0; |
6711 | ||
6712 | return 1; | |
6713 | } | |
6714 | ||
48f24c4d IM |
6715 | static int |
6716 | sd_parent_degenerate(struct sched_domain *sd, struct sched_domain *parent) | |
245af2c7 SS |
6717 | { |
6718 | unsigned long cflags = sd->flags, pflags = parent->flags; | |
6719 | ||
6720 | if (sd_degenerate(parent)) | |
6721 | return 1; | |
6722 | ||
758b2cdc | 6723 | if (!cpumask_equal(sched_domain_span(sd), sched_domain_span(parent))) |
245af2c7 SS |
6724 | return 0; |
6725 | ||
245af2c7 SS |
6726 | /* Flags needing groups don't count if only 1 group in parent */ |
6727 | if (parent->groups == parent->groups->next) { | |
6728 | pflags &= ~(SD_LOAD_BALANCE | | |
6729 | SD_BALANCE_NEWIDLE | | |
6730 | SD_BALANCE_FORK | | |
89c4710e SS |
6731 | SD_BALANCE_EXEC | |
6732 | SD_SHARE_CPUPOWER | | |
6733 | SD_SHARE_PKG_RESOURCES); | |
5436499e KC |
6734 | if (nr_node_ids == 1) |
6735 | pflags &= ~SD_SERIALIZE; | |
245af2c7 SS |
6736 | } |
6737 | if (~cflags & pflags) | |
6738 | return 0; | |
6739 | ||
6740 | return 1; | |
6741 | } | |
6742 | ||
dce840a0 | 6743 | static void free_rootdomain(struct rcu_head *rcu) |
c6c4927b | 6744 | { |
dce840a0 | 6745 | struct root_domain *rd = container_of(rcu, struct root_domain, rcu); |
047106ad | 6746 | |
68e74568 | 6747 | cpupri_cleanup(&rd->cpupri); |
c6c4927b RR |
6748 | free_cpumask_var(rd->rto_mask); |
6749 | free_cpumask_var(rd->online); | |
6750 | free_cpumask_var(rd->span); | |
6751 | kfree(rd); | |
6752 | } | |
6753 | ||
57d885fe GH |
6754 | static void rq_attach_root(struct rq *rq, struct root_domain *rd) |
6755 | { | |
a0490fa3 | 6756 | struct root_domain *old_rd = NULL; |
57d885fe | 6757 | unsigned long flags; |
57d885fe | 6758 | |
05fa785c | 6759 | raw_spin_lock_irqsave(&rq->lock, flags); |
57d885fe GH |
6760 | |
6761 | if (rq->rd) { | |
a0490fa3 | 6762 | old_rd = rq->rd; |
57d885fe | 6763 | |
c6c4927b | 6764 | if (cpumask_test_cpu(rq->cpu, old_rd->online)) |
1f11eb6a | 6765 | set_rq_offline(rq); |
57d885fe | 6766 | |
c6c4927b | 6767 | cpumask_clear_cpu(rq->cpu, old_rd->span); |
dc938520 | 6768 | |
a0490fa3 IM |
6769 | /* |
6770 | * If we dont want to free the old_rt yet then | |
6771 | * set old_rd to NULL to skip the freeing later | |
6772 | * in this function: | |
6773 | */ | |
6774 | if (!atomic_dec_and_test(&old_rd->refcount)) | |
6775 | old_rd = NULL; | |
57d885fe GH |
6776 | } |
6777 | ||
6778 | atomic_inc(&rd->refcount); | |
6779 | rq->rd = rd; | |
6780 | ||
c6c4927b | 6781 | cpumask_set_cpu(rq->cpu, rd->span); |
00aec93d | 6782 | if (cpumask_test_cpu(rq->cpu, cpu_active_mask)) |
1f11eb6a | 6783 | set_rq_online(rq); |
57d885fe | 6784 | |
05fa785c | 6785 | raw_spin_unlock_irqrestore(&rq->lock, flags); |
a0490fa3 IM |
6786 | |
6787 | if (old_rd) | |
dce840a0 | 6788 | call_rcu_sched(&old_rd->rcu, free_rootdomain); |
57d885fe GH |
6789 | } |
6790 | ||
68c38fc3 | 6791 | static int init_rootdomain(struct root_domain *rd) |
57d885fe GH |
6792 | { |
6793 | memset(rd, 0, sizeof(*rd)); | |
6794 | ||
68c38fc3 | 6795 | if (!alloc_cpumask_var(&rd->span, GFP_KERNEL)) |
0c910d28 | 6796 | goto out; |
68c38fc3 | 6797 | if (!alloc_cpumask_var(&rd->online, GFP_KERNEL)) |
c6c4927b | 6798 | goto free_span; |
68c38fc3 | 6799 | if (!alloc_cpumask_var(&rd->rto_mask, GFP_KERNEL)) |
c6c4927b | 6800 | goto free_online; |
6e0534f2 | 6801 | |
68c38fc3 | 6802 | if (cpupri_init(&rd->cpupri) != 0) |
68e74568 | 6803 | goto free_rto_mask; |
c6c4927b | 6804 | return 0; |
6e0534f2 | 6805 | |
68e74568 RR |
6806 | free_rto_mask: |
6807 | free_cpumask_var(rd->rto_mask); | |
c6c4927b RR |
6808 | free_online: |
6809 | free_cpumask_var(rd->online); | |
6810 | free_span: | |
6811 | free_cpumask_var(rd->span); | |
0c910d28 | 6812 | out: |
c6c4927b | 6813 | return -ENOMEM; |
57d885fe GH |
6814 | } |
6815 | ||
6816 | static void init_defrootdomain(void) | |
6817 | { | |
68c38fc3 | 6818 | init_rootdomain(&def_root_domain); |
c6c4927b | 6819 | |
57d885fe GH |
6820 | atomic_set(&def_root_domain.refcount, 1); |
6821 | } | |
6822 | ||
dc938520 | 6823 | static struct root_domain *alloc_rootdomain(void) |
57d885fe GH |
6824 | { |
6825 | struct root_domain *rd; | |
6826 | ||
6827 | rd = kmalloc(sizeof(*rd), GFP_KERNEL); | |
6828 | if (!rd) | |
6829 | return NULL; | |
6830 | ||
68c38fc3 | 6831 | if (init_rootdomain(rd) != 0) { |
c6c4927b RR |
6832 | kfree(rd); |
6833 | return NULL; | |
6834 | } | |
57d885fe GH |
6835 | |
6836 | return rd; | |
6837 | } | |
6838 | ||
e3589f6c PZ |
6839 | static void free_sched_groups(struct sched_group *sg, int free_sgp) |
6840 | { | |
6841 | struct sched_group *tmp, *first; | |
6842 | ||
6843 | if (!sg) | |
6844 | return; | |
6845 | ||
6846 | first = sg; | |
6847 | do { | |
6848 | tmp = sg->next; | |
6849 | ||
6850 | if (free_sgp && atomic_dec_and_test(&sg->sgp->ref)) | |
6851 | kfree(sg->sgp); | |
6852 | ||
6853 | kfree(sg); | |
6854 | sg = tmp; | |
6855 | } while (sg != first); | |
6856 | } | |
6857 | ||
dce840a0 PZ |
6858 | static void free_sched_domain(struct rcu_head *rcu) |
6859 | { | |
6860 | struct sched_domain *sd = container_of(rcu, struct sched_domain, rcu); | |
e3589f6c PZ |
6861 | |
6862 | /* | |
6863 | * If its an overlapping domain it has private groups, iterate and | |
6864 | * nuke them all. | |
6865 | */ | |
6866 | if (sd->flags & SD_OVERLAP) { | |
6867 | free_sched_groups(sd->groups, 1); | |
6868 | } else if (atomic_dec_and_test(&sd->groups->ref)) { | |
9c3f75cb | 6869 | kfree(sd->groups->sgp); |
dce840a0 | 6870 | kfree(sd->groups); |
9c3f75cb | 6871 | } |
dce840a0 PZ |
6872 | kfree(sd); |
6873 | } | |
6874 | ||
6875 | static void destroy_sched_domain(struct sched_domain *sd, int cpu) | |
6876 | { | |
6877 | call_rcu(&sd->rcu, free_sched_domain); | |
6878 | } | |
6879 | ||
6880 | static void destroy_sched_domains(struct sched_domain *sd, int cpu) | |
6881 | { | |
6882 | for (; sd; sd = sd->parent) | |
6883 | destroy_sched_domain(sd, cpu); | |
6884 | } | |
6885 | ||
1da177e4 | 6886 | /* |
0eab9146 | 6887 | * Attach the domain 'sd' to 'cpu' as its base domain. Callers must |
1da177e4 LT |
6888 | * hold the hotplug lock. |
6889 | */ | |
0eab9146 IM |
6890 | static void |
6891 | cpu_attach_domain(struct sched_domain *sd, struct root_domain *rd, int cpu) | |
1da177e4 | 6892 | { |
70b97a7f | 6893 | struct rq *rq = cpu_rq(cpu); |
245af2c7 SS |
6894 | struct sched_domain *tmp; |
6895 | ||
6896 | /* Remove the sched domains which do not contribute to scheduling. */ | |
f29c9b1c | 6897 | for (tmp = sd; tmp; ) { |
245af2c7 SS |
6898 | struct sched_domain *parent = tmp->parent; |
6899 | if (!parent) | |
6900 | break; | |
f29c9b1c | 6901 | |
1a848870 | 6902 | if (sd_parent_degenerate(tmp, parent)) { |
245af2c7 | 6903 | tmp->parent = parent->parent; |
1a848870 SS |
6904 | if (parent->parent) |
6905 | parent->parent->child = tmp; | |
dce840a0 | 6906 | destroy_sched_domain(parent, cpu); |
f29c9b1c LZ |
6907 | } else |
6908 | tmp = tmp->parent; | |
245af2c7 SS |
6909 | } |
6910 | ||
1a848870 | 6911 | if (sd && sd_degenerate(sd)) { |
dce840a0 | 6912 | tmp = sd; |
245af2c7 | 6913 | sd = sd->parent; |
dce840a0 | 6914 | destroy_sched_domain(tmp, cpu); |
1a848870 SS |
6915 | if (sd) |
6916 | sd->child = NULL; | |
6917 | } | |
1da177e4 | 6918 | |
4cb98839 | 6919 | sched_domain_debug(sd, cpu); |
1da177e4 | 6920 | |
57d885fe | 6921 | rq_attach_root(rq, rd); |
dce840a0 | 6922 | tmp = rq->sd; |
674311d5 | 6923 | rcu_assign_pointer(rq->sd, sd); |
dce840a0 | 6924 | destroy_sched_domains(tmp, cpu); |
1da177e4 LT |
6925 | } |
6926 | ||
6927 | /* cpus with isolated domains */ | |
dcc30a35 | 6928 | static cpumask_var_t cpu_isolated_map; |
1da177e4 LT |
6929 | |
6930 | /* Setup the mask of cpus configured for isolated domains */ | |
6931 | static int __init isolated_cpu_setup(char *str) | |
6932 | { | |
bdddd296 | 6933 | alloc_bootmem_cpumask_var(&cpu_isolated_map); |
968ea6d8 | 6934 | cpulist_parse(str, cpu_isolated_map); |
1da177e4 LT |
6935 | return 1; |
6936 | } | |
6937 | ||
8927f494 | 6938 | __setup("isolcpus=", isolated_cpu_setup); |
1da177e4 | 6939 | |
9c1cfda2 | 6940 | #define SD_NODES_PER_DOMAIN 16 |
1da177e4 | 6941 | |
9c1cfda2 | 6942 | #ifdef CONFIG_NUMA |
198e2f18 | 6943 | |
9c1cfda2 JH |
6944 | /** |
6945 | * find_next_best_node - find the next node to include in a sched_domain | |
6946 | * @node: node whose sched_domain we're building | |
6947 | * @used_nodes: nodes already in the sched_domain | |
6948 | * | |
41a2d6cf | 6949 | * Find the next node to include in a given scheduling domain. Simply |
9c1cfda2 JH |
6950 | * finds the closest node not already in the @used_nodes map. |
6951 | * | |
6952 | * Should use nodemask_t. | |
6953 | */ | |
c5f59f08 | 6954 | static int find_next_best_node(int node, nodemask_t *used_nodes) |
9c1cfda2 | 6955 | { |
7142d17e | 6956 | int i, n, val, min_val, best_node = -1; |
9c1cfda2 JH |
6957 | |
6958 | min_val = INT_MAX; | |
6959 | ||
076ac2af | 6960 | for (i = 0; i < nr_node_ids; i++) { |
9c1cfda2 | 6961 | /* Start at @node */ |
076ac2af | 6962 | n = (node + i) % nr_node_ids; |
9c1cfda2 JH |
6963 | |
6964 | if (!nr_cpus_node(n)) | |
6965 | continue; | |
6966 | ||
6967 | /* Skip already used nodes */ | |
c5f59f08 | 6968 | if (node_isset(n, *used_nodes)) |
9c1cfda2 JH |
6969 | continue; |
6970 | ||
6971 | /* Simple min distance search */ | |
6972 | val = node_distance(node, n); | |
6973 | ||
6974 | if (val < min_val) { | |
6975 | min_val = val; | |
6976 | best_node = n; | |
6977 | } | |
6978 | } | |
6979 | ||
7142d17e HD |
6980 | if (best_node != -1) |
6981 | node_set(best_node, *used_nodes); | |
9c1cfda2 JH |
6982 | return best_node; |
6983 | } | |
6984 | ||
6985 | /** | |
6986 | * sched_domain_node_span - get a cpumask for a node's sched_domain | |
6987 | * @node: node whose cpumask we're constructing | |
73486722 | 6988 | * @span: resulting cpumask |
9c1cfda2 | 6989 | * |
41a2d6cf | 6990 | * Given a node, construct a good cpumask for its sched_domain to span. It |
9c1cfda2 JH |
6991 | * should be one that prevents unnecessary balancing, but also spreads tasks |
6992 | * out optimally. | |
6993 | */ | |
96f874e2 | 6994 | static void sched_domain_node_span(int node, struct cpumask *span) |
9c1cfda2 | 6995 | { |
c5f59f08 | 6996 | nodemask_t used_nodes; |
48f24c4d | 6997 | int i; |
9c1cfda2 | 6998 | |
6ca09dfc | 6999 | cpumask_clear(span); |
c5f59f08 | 7000 | nodes_clear(used_nodes); |
9c1cfda2 | 7001 | |
6ca09dfc | 7002 | cpumask_or(span, span, cpumask_of_node(node)); |
c5f59f08 | 7003 | node_set(node, used_nodes); |
9c1cfda2 JH |
7004 | |
7005 | for (i = 1; i < SD_NODES_PER_DOMAIN; i++) { | |
c5f59f08 | 7006 | int next_node = find_next_best_node(node, &used_nodes); |
7142d17e HD |
7007 | if (next_node < 0) |
7008 | break; | |
6ca09dfc | 7009 | cpumask_or(span, span, cpumask_of_node(next_node)); |
9c1cfda2 | 7010 | } |
9c1cfda2 | 7011 | } |
d3081f52 PZ |
7012 | |
7013 | static const struct cpumask *cpu_node_mask(int cpu) | |
7014 | { | |
7015 | lockdep_assert_held(&sched_domains_mutex); | |
7016 | ||
7017 | sched_domain_node_span(cpu_to_node(cpu), sched_domains_tmpmask); | |
7018 | ||
7019 | return sched_domains_tmpmask; | |
7020 | } | |
2c402dc3 PZ |
7021 | |
7022 | static const struct cpumask *cpu_allnodes_mask(int cpu) | |
7023 | { | |
7024 | return cpu_possible_mask; | |
7025 | } | |
6d6bc0ad | 7026 | #endif /* CONFIG_NUMA */ |
9c1cfda2 | 7027 | |
d3081f52 PZ |
7028 | static const struct cpumask *cpu_cpu_mask(int cpu) |
7029 | { | |
7030 | return cpumask_of_node(cpu_to_node(cpu)); | |
7031 | } | |
7032 | ||
5c45bf27 | 7033 | int sched_smt_power_savings = 0, sched_mc_power_savings = 0; |
48f24c4d | 7034 | |
dce840a0 PZ |
7035 | struct sd_data { |
7036 | struct sched_domain **__percpu sd; | |
7037 | struct sched_group **__percpu sg; | |
9c3f75cb | 7038 | struct sched_group_power **__percpu sgp; |
dce840a0 PZ |
7039 | }; |
7040 | ||
49a02c51 | 7041 | struct s_data { |
21d42ccf | 7042 | struct sched_domain ** __percpu sd; |
49a02c51 AH |
7043 | struct root_domain *rd; |
7044 | }; | |
7045 | ||
2109b99e | 7046 | enum s_alloc { |
2109b99e | 7047 | sa_rootdomain, |
21d42ccf | 7048 | sa_sd, |
dce840a0 | 7049 | sa_sd_storage, |
2109b99e AH |
7050 | sa_none, |
7051 | }; | |
7052 | ||
54ab4ff4 PZ |
7053 | struct sched_domain_topology_level; |
7054 | ||
7055 | typedef struct sched_domain *(*sched_domain_init_f)(struct sched_domain_topology_level *tl, int cpu); | |
eb7a74e6 PZ |
7056 | typedef const struct cpumask *(*sched_domain_mask_f)(int cpu); |
7057 | ||
e3589f6c PZ |
7058 | #define SDTL_OVERLAP 0x01 |
7059 | ||
eb7a74e6 | 7060 | struct sched_domain_topology_level { |
2c402dc3 PZ |
7061 | sched_domain_init_f init; |
7062 | sched_domain_mask_f mask; | |
e3589f6c | 7063 | int flags; |
54ab4ff4 | 7064 | struct sd_data data; |
eb7a74e6 PZ |
7065 | }; |
7066 | ||
e3589f6c PZ |
7067 | static int |
7068 | build_overlap_sched_groups(struct sched_domain *sd, int cpu) | |
7069 | { | |
7070 | struct sched_group *first = NULL, *last = NULL, *groups = NULL, *sg; | |
7071 | const struct cpumask *span = sched_domain_span(sd); | |
7072 | struct cpumask *covered = sched_domains_tmpmask; | |
7073 | struct sd_data *sdd = sd->private; | |
7074 | struct sched_domain *child; | |
7075 | int i; | |
7076 | ||
7077 | cpumask_clear(covered); | |
7078 | ||
7079 | for_each_cpu(i, span) { | |
7080 | struct cpumask *sg_span; | |
7081 | ||
7082 | if (cpumask_test_cpu(i, covered)) | |
7083 | continue; | |
7084 | ||
7085 | sg = kzalloc_node(sizeof(struct sched_group) + cpumask_size(), | |
7086 | GFP_KERNEL, cpu_to_node(i)); | |
7087 | ||
7088 | if (!sg) | |
7089 | goto fail; | |
7090 | ||
7091 | sg_span = sched_group_cpus(sg); | |
7092 | ||
7093 | child = *per_cpu_ptr(sdd->sd, i); | |
7094 | if (child->child) { | |
7095 | child = child->child; | |
7096 | cpumask_copy(sg_span, sched_domain_span(child)); | |
7097 | } else | |
7098 | cpumask_set_cpu(i, sg_span); | |
7099 | ||
7100 | cpumask_or(covered, covered, sg_span); | |
7101 | ||
7102 | sg->sgp = *per_cpu_ptr(sdd->sgp, cpumask_first(sg_span)); | |
7103 | atomic_inc(&sg->sgp->ref); | |
7104 | ||
7105 | if (cpumask_test_cpu(cpu, sg_span)) | |
7106 | groups = sg; | |
7107 | ||
7108 | if (!first) | |
7109 | first = sg; | |
7110 | if (last) | |
7111 | last->next = sg; | |
7112 | last = sg; | |
7113 | last->next = first; | |
7114 | } | |
7115 | sd->groups = groups; | |
7116 | ||
7117 | return 0; | |
7118 | ||
7119 | fail: | |
7120 | free_sched_groups(first, 0); | |
7121 | ||
7122 | return -ENOMEM; | |
7123 | } | |
7124 | ||
dce840a0 | 7125 | static int get_group(int cpu, struct sd_data *sdd, struct sched_group **sg) |
1da177e4 | 7126 | { |
dce840a0 PZ |
7127 | struct sched_domain *sd = *per_cpu_ptr(sdd->sd, cpu); |
7128 | struct sched_domain *child = sd->child; | |
1da177e4 | 7129 | |
dce840a0 PZ |
7130 | if (child) |
7131 | cpu = cpumask_first(sched_domain_span(child)); | |
1e9f28fa | 7132 | |
9c3f75cb | 7133 | if (sg) { |
dce840a0 | 7134 | *sg = *per_cpu_ptr(sdd->sg, cpu); |
9c3f75cb | 7135 | (*sg)->sgp = *per_cpu_ptr(sdd->sgp, cpu); |
e3589f6c | 7136 | atomic_set(&(*sg)->sgp->ref, 1); /* for claim_allocations */ |
9c3f75cb | 7137 | } |
dce840a0 PZ |
7138 | |
7139 | return cpu; | |
1e9f28fa | 7140 | } |
1e9f28fa | 7141 | |
01a08546 | 7142 | /* |
dce840a0 PZ |
7143 | * build_sched_groups will build a circular linked list of the groups |
7144 | * covered by the given span, and will set each group's ->cpumask correctly, | |
7145 | * and ->cpu_power to 0. | |
e3589f6c PZ |
7146 | * |
7147 | * Assumes the sched_domain tree is fully constructed | |
01a08546 | 7148 | */ |
e3589f6c PZ |
7149 | static int |
7150 | build_sched_groups(struct sched_domain *sd, int cpu) | |
1da177e4 | 7151 | { |
dce840a0 PZ |
7152 | struct sched_group *first = NULL, *last = NULL; |
7153 | struct sd_data *sdd = sd->private; | |
7154 | const struct cpumask *span = sched_domain_span(sd); | |
f96225fd | 7155 | struct cpumask *covered; |
dce840a0 | 7156 | int i; |
9c1cfda2 | 7157 | |
e3589f6c PZ |
7158 | get_group(cpu, sdd, &sd->groups); |
7159 | atomic_inc(&sd->groups->ref); | |
7160 | ||
7161 | if (cpu != cpumask_first(sched_domain_span(sd))) | |
7162 | return 0; | |
7163 | ||
f96225fd PZ |
7164 | lockdep_assert_held(&sched_domains_mutex); |
7165 | covered = sched_domains_tmpmask; | |
7166 | ||
dce840a0 | 7167 | cpumask_clear(covered); |
6711cab4 | 7168 | |
dce840a0 PZ |
7169 | for_each_cpu(i, span) { |
7170 | struct sched_group *sg; | |
7171 | int group = get_group(i, sdd, &sg); | |
7172 | int j; | |
6711cab4 | 7173 | |
dce840a0 PZ |
7174 | if (cpumask_test_cpu(i, covered)) |
7175 | continue; | |
6711cab4 | 7176 | |
dce840a0 | 7177 | cpumask_clear(sched_group_cpus(sg)); |
9c3f75cb | 7178 | sg->sgp->power = 0; |
0601a88d | 7179 | |
dce840a0 PZ |
7180 | for_each_cpu(j, span) { |
7181 | if (get_group(j, sdd, NULL) != group) | |
7182 | continue; | |
0601a88d | 7183 | |
dce840a0 PZ |
7184 | cpumask_set_cpu(j, covered); |
7185 | cpumask_set_cpu(j, sched_group_cpus(sg)); | |
7186 | } | |
0601a88d | 7187 | |
dce840a0 PZ |
7188 | if (!first) |
7189 | first = sg; | |
7190 | if (last) | |
7191 | last->next = sg; | |
7192 | last = sg; | |
7193 | } | |
7194 | last->next = first; | |
e3589f6c PZ |
7195 | |
7196 | return 0; | |
0601a88d | 7197 | } |
51888ca2 | 7198 | |
89c4710e SS |
7199 | /* |
7200 | * Initialize sched groups cpu_power. | |
7201 | * | |
7202 | * cpu_power indicates the capacity of sched group, which is used while | |
7203 | * distributing the load between different sched groups in a sched domain. | |
7204 | * Typically cpu_power for all the groups in a sched domain will be same unless | |
7205 | * there are asymmetries in the topology. If there are asymmetries, group | |
7206 | * having more cpu_power will pickup more load compared to the group having | |
7207 | * less cpu_power. | |
89c4710e SS |
7208 | */ |
7209 | static void init_sched_groups_power(int cpu, struct sched_domain *sd) | |
7210 | { | |
e3589f6c | 7211 | struct sched_group *sg = sd->groups; |
89c4710e | 7212 | |
e3589f6c PZ |
7213 | WARN_ON(!sd || !sg); |
7214 | ||
7215 | do { | |
7216 | sg->group_weight = cpumask_weight(sched_group_cpus(sg)); | |
7217 | sg = sg->next; | |
7218 | } while (sg != sd->groups); | |
89c4710e | 7219 | |
e3589f6c PZ |
7220 | if (cpu != group_first_cpu(sg)) |
7221 | return; | |
aae6d3dd | 7222 | |
d274cb30 | 7223 | update_group_power(sd, cpu); |
89c4710e SS |
7224 | } |
7225 | ||
7c16ec58 MT |
7226 | /* |
7227 | * Initializers for schedule domains | |
7228 | * Non-inlined to reduce accumulated stack pressure in build_sched_domains() | |
7229 | */ | |
7230 | ||
a5d8c348 IM |
7231 | #ifdef CONFIG_SCHED_DEBUG |
7232 | # define SD_INIT_NAME(sd, type) sd->name = #type | |
7233 | #else | |
7234 | # define SD_INIT_NAME(sd, type) do { } while (0) | |
7235 | #endif | |
7236 | ||
54ab4ff4 PZ |
7237 | #define SD_INIT_FUNC(type) \ |
7238 | static noinline struct sched_domain * \ | |
7239 | sd_init_##type(struct sched_domain_topology_level *tl, int cpu) \ | |
7240 | { \ | |
7241 | struct sched_domain *sd = *per_cpu_ptr(tl->data.sd, cpu); \ | |
7242 | *sd = SD_##type##_INIT; \ | |
54ab4ff4 PZ |
7243 | SD_INIT_NAME(sd, type); \ |
7244 | sd->private = &tl->data; \ | |
7245 | return sd; \ | |
7c16ec58 MT |
7246 | } |
7247 | ||
7248 | SD_INIT_FUNC(CPU) | |
7249 | #ifdef CONFIG_NUMA | |
7250 | SD_INIT_FUNC(ALLNODES) | |
7251 | SD_INIT_FUNC(NODE) | |
7252 | #endif | |
7253 | #ifdef CONFIG_SCHED_SMT | |
7254 | SD_INIT_FUNC(SIBLING) | |
7255 | #endif | |
7256 | #ifdef CONFIG_SCHED_MC | |
7257 | SD_INIT_FUNC(MC) | |
7258 | #endif | |
01a08546 HC |
7259 | #ifdef CONFIG_SCHED_BOOK |
7260 | SD_INIT_FUNC(BOOK) | |
7261 | #endif | |
7c16ec58 | 7262 | |
1d3504fc | 7263 | static int default_relax_domain_level = -1; |
60495e77 | 7264 | int sched_domain_level_max; |
1d3504fc HS |
7265 | |
7266 | static int __init setup_relax_domain_level(char *str) | |
7267 | { | |
30e0e178 LZ |
7268 | unsigned long val; |
7269 | ||
7270 | val = simple_strtoul(str, NULL, 0); | |
60495e77 | 7271 | if (val < sched_domain_level_max) |
30e0e178 LZ |
7272 | default_relax_domain_level = val; |
7273 | ||
1d3504fc HS |
7274 | return 1; |
7275 | } | |
7276 | __setup("relax_domain_level=", setup_relax_domain_level); | |
7277 | ||
7278 | static void set_domain_attribute(struct sched_domain *sd, | |
7279 | struct sched_domain_attr *attr) | |
7280 | { | |
7281 | int request; | |
7282 | ||
7283 | if (!attr || attr->relax_domain_level < 0) { | |
7284 | if (default_relax_domain_level < 0) | |
7285 | return; | |
7286 | else | |
7287 | request = default_relax_domain_level; | |
7288 | } else | |
7289 | request = attr->relax_domain_level; | |
7290 | if (request < sd->level) { | |
7291 | /* turn off idle balance on this domain */ | |
c88d5910 | 7292 | sd->flags &= ~(SD_BALANCE_WAKE|SD_BALANCE_NEWIDLE); |
1d3504fc HS |
7293 | } else { |
7294 | /* turn on idle balance on this domain */ | |
c88d5910 | 7295 | sd->flags |= (SD_BALANCE_WAKE|SD_BALANCE_NEWIDLE); |
1d3504fc HS |
7296 | } |
7297 | } | |
7298 | ||
54ab4ff4 PZ |
7299 | static void __sdt_free(const struct cpumask *cpu_map); |
7300 | static int __sdt_alloc(const struct cpumask *cpu_map); | |
7301 | ||
2109b99e AH |
7302 | static void __free_domain_allocs(struct s_data *d, enum s_alloc what, |
7303 | const struct cpumask *cpu_map) | |
7304 | { | |
7305 | switch (what) { | |
2109b99e | 7306 | case sa_rootdomain: |
822ff793 PZ |
7307 | if (!atomic_read(&d->rd->refcount)) |
7308 | free_rootdomain(&d->rd->rcu); /* fall through */ | |
21d42ccf PZ |
7309 | case sa_sd: |
7310 | free_percpu(d->sd); /* fall through */ | |
dce840a0 | 7311 | case sa_sd_storage: |
54ab4ff4 | 7312 | __sdt_free(cpu_map); /* fall through */ |
2109b99e AH |
7313 | case sa_none: |
7314 | break; | |
7315 | } | |
7316 | } | |
3404c8d9 | 7317 | |
2109b99e AH |
7318 | static enum s_alloc __visit_domain_allocation_hell(struct s_data *d, |
7319 | const struct cpumask *cpu_map) | |
7320 | { | |
dce840a0 PZ |
7321 | memset(d, 0, sizeof(*d)); |
7322 | ||
54ab4ff4 PZ |
7323 | if (__sdt_alloc(cpu_map)) |
7324 | return sa_sd_storage; | |
dce840a0 PZ |
7325 | d->sd = alloc_percpu(struct sched_domain *); |
7326 | if (!d->sd) | |
7327 | return sa_sd_storage; | |
2109b99e | 7328 | d->rd = alloc_rootdomain(); |
dce840a0 | 7329 | if (!d->rd) |
21d42ccf | 7330 | return sa_sd; |
2109b99e AH |
7331 | return sa_rootdomain; |
7332 | } | |
57d885fe | 7333 | |
dce840a0 PZ |
7334 | /* |
7335 | * NULL the sd_data elements we've used to build the sched_domain and | |
7336 | * sched_group structure so that the subsequent __free_domain_allocs() | |
7337 | * will not free the data we're using. | |
7338 | */ | |
7339 | static void claim_allocations(int cpu, struct sched_domain *sd) | |
7340 | { | |
7341 | struct sd_data *sdd = sd->private; | |
dce840a0 PZ |
7342 | |
7343 | WARN_ON_ONCE(*per_cpu_ptr(sdd->sd, cpu) != sd); | |
7344 | *per_cpu_ptr(sdd->sd, cpu) = NULL; | |
7345 | ||
e3589f6c | 7346 | if (atomic_read(&(*per_cpu_ptr(sdd->sg, cpu))->ref)) |
dce840a0 | 7347 | *per_cpu_ptr(sdd->sg, cpu) = NULL; |
e3589f6c PZ |
7348 | |
7349 | if (atomic_read(&(*per_cpu_ptr(sdd->sgp, cpu))->ref)) | |
9c3f75cb | 7350 | *per_cpu_ptr(sdd->sgp, cpu) = NULL; |
dce840a0 PZ |
7351 | } |
7352 | ||
2c402dc3 PZ |
7353 | #ifdef CONFIG_SCHED_SMT |
7354 | static const struct cpumask *cpu_smt_mask(int cpu) | |
7f4588f3 | 7355 | { |
2c402dc3 | 7356 | return topology_thread_cpumask(cpu); |
3bd65a80 | 7357 | } |
2c402dc3 | 7358 | #endif |
7f4588f3 | 7359 | |
d069b916 PZ |
7360 | /* |
7361 | * Topology list, bottom-up. | |
7362 | */ | |
2c402dc3 | 7363 | static struct sched_domain_topology_level default_topology[] = { |
d069b916 PZ |
7364 | #ifdef CONFIG_SCHED_SMT |
7365 | { sd_init_SIBLING, cpu_smt_mask, }, | |
01a08546 | 7366 | #endif |
1e9f28fa | 7367 | #ifdef CONFIG_SCHED_MC |
2c402dc3 | 7368 | { sd_init_MC, cpu_coregroup_mask, }, |
1e9f28fa | 7369 | #endif |
d069b916 PZ |
7370 | #ifdef CONFIG_SCHED_BOOK |
7371 | { sd_init_BOOK, cpu_book_mask, }, | |
7372 | #endif | |
7373 | { sd_init_CPU, cpu_cpu_mask, }, | |
7374 | #ifdef CONFIG_NUMA | |
e3589f6c | 7375 | { sd_init_NODE, cpu_node_mask, SDTL_OVERLAP, }, |
d069b916 | 7376 | { sd_init_ALLNODES, cpu_allnodes_mask, }, |
1da177e4 | 7377 | #endif |
eb7a74e6 PZ |
7378 | { NULL, }, |
7379 | }; | |
7380 | ||
7381 | static struct sched_domain_topology_level *sched_domain_topology = default_topology; | |
7382 | ||
54ab4ff4 PZ |
7383 | static int __sdt_alloc(const struct cpumask *cpu_map) |
7384 | { | |
7385 | struct sched_domain_topology_level *tl; | |
7386 | int j; | |
7387 | ||
7388 | for (tl = sched_domain_topology; tl->init; tl++) { | |
7389 | struct sd_data *sdd = &tl->data; | |
7390 | ||
7391 | sdd->sd = alloc_percpu(struct sched_domain *); | |
7392 | if (!sdd->sd) | |
7393 | return -ENOMEM; | |
7394 | ||
7395 | sdd->sg = alloc_percpu(struct sched_group *); | |
7396 | if (!sdd->sg) | |
7397 | return -ENOMEM; | |
7398 | ||
9c3f75cb PZ |
7399 | sdd->sgp = alloc_percpu(struct sched_group_power *); |
7400 | if (!sdd->sgp) | |
7401 | return -ENOMEM; | |
7402 | ||
54ab4ff4 PZ |
7403 | for_each_cpu(j, cpu_map) { |
7404 | struct sched_domain *sd; | |
7405 | struct sched_group *sg; | |
9c3f75cb | 7406 | struct sched_group_power *sgp; |
54ab4ff4 PZ |
7407 | |
7408 | sd = kzalloc_node(sizeof(struct sched_domain) + cpumask_size(), | |
7409 | GFP_KERNEL, cpu_to_node(j)); | |
7410 | if (!sd) | |
7411 | return -ENOMEM; | |
7412 | ||
7413 | *per_cpu_ptr(sdd->sd, j) = sd; | |
7414 | ||
7415 | sg = kzalloc_node(sizeof(struct sched_group) + cpumask_size(), | |
7416 | GFP_KERNEL, cpu_to_node(j)); | |
7417 | if (!sg) | |
7418 | return -ENOMEM; | |
7419 | ||
7420 | *per_cpu_ptr(sdd->sg, j) = sg; | |
9c3f75cb PZ |
7421 | |
7422 | sgp = kzalloc_node(sizeof(struct sched_group_power), | |
7423 | GFP_KERNEL, cpu_to_node(j)); | |
7424 | if (!sgp) | |
7425 | return -ENOMEM; | |
7426 | ||
7427 | *per_cpu_ptr(sdd->sgp, j) = sgp; | |
54ab4ff4 PZ |
7428 | } |
7429 | } | |
7430 | ||
7431 | return 0; | |
7432 | } | |
7433 | ||
7434 | static void __sdt_free(const struct cpumask *cpu_map) | |
7435 | { | |
7436 | struct sched_domain_topology_level *tl; | |
7437 | int j; | |
7438 | ||
7439 | for (tl = sched_domain_topology; tl->init; tl++) { | |
7440 | struct sd_data *sdd = &tl->data; | |
7441 | ||
7442 | for_each_cpu(j, cpu_map) { | |
e3589f6c PZ |
7443 | struct sched_domain *sd = *per_cpu_ptr(sdd->sd, j); |
7444 | if (sd && (sd->flags & SD_OVERLAP)) | |
7445 | free_sched_groups(sd->groups, 0); | |
54ab4ff4 | 7446 | kfree(*per_cpu_ptr(sdd->sg, j)); |
9c3f75cb | 7447 | kfree(*per_cpu_ptr(sdd->sgp, j)); |
54ab4ff4 PZ |
7448 | } |
7449 | free_percpu(sdd->sd); | |
7450 | free_percpu(sdd->sg); | |
9c3f75cb | 7451 | free_percpu(sdd->sgp); |
54ab4ff4 PZ |
7452 | } |
7453 | } | |
7454 | ||
2c402dc3 PZ |
7455 | struct sched_domain *build_sched_domain(struct sched_domain_topology_level *tl, |
7456 | struct s_data *d, const struct cpumask *cpu_map, | |
d069b916 | 7457 | struct sched_domain_attr *attr, struct sched_domain *child, |
2c402dc3 PZ |
7458 | int cpu) |
7459 | { | |
54ab4ff4 | 7460 | struct sched_domain *sd = tl->init(tl, cpu); |
2c402dc3 | 7461 | if (!sd) |
d069b916 | 7462 | return child; |
2c402dc3 PZ |
7463 | |
7464 | set_domain_attribute(sd, attr); | |
7465 | cpumask_and(sched_domain_span(sd), cpu_map, tl->mask(cpu)); | |
60495e77 PZ |
7466 | if (child) { |
7467 | sd->level = child->level + 1; | |
7468 | sched_domain_level_max = max(sched_domain_level_max, sd->level); | |
d069b916 | 7469 | child->parent = sd; |
60495e77 | 7470 | } |
d069b916 | 7471 | sd->child = child; |
2c402dc3 PZ |
7472 | |
7473 | return sd; | |
7474 | } | |
7475 | ||
2109b99e AH |
7476 | /* |
7477 | * Build sched domains for a given set of cpus and attach the sched domains | |
7478 | * to the individual cpus | |
7479 | */ | |
dce840a0 PZ |
7480 | static int build_sched_domains(const struct cpumask *cpu_map, |
7481 | struct sched_domain_attr *attr) | |
2109b99e AH |
7482 | { |
7483 | enum s_alloc alloc_state = sa_none; | |
dce840a0 | 7484 | struct sched_domain *sd; |
2109b99e | 7485 | struct s_data d; |
822ff793 | 7486 | int i, ret = -ENOMEM; |
9c1cfda2 | 7487 | |
2109b99e AH |
7488 | alloc_state = __visit_domain_allocation_hell(&d, cpu_map); |
7489 | if (alloc_state != sa_rootdomain) | |
7490 | goto error; | |
9c1cfda2 | 7491 | |
dce840a0 | 7492 | /* Set up domains for cpus specified by the cpu_map. */ |
abcd083a | 7493 | for_each_cpu(i, cpu_map) { |
eb7a74e6 PZ |
7494 | struct sched_domain_topology_level *tl; |
7495 | ||
3bd65a80 | 7496 | sd = NULL; |
e3589f6c | 7497 | for (tl = sched_domain_topology; tl->init; tl++) { |
2c402dc3 | 7498 | sd = build_sched_domain(tl, &d, cpu_map, attr, sd, i); |
e3589f6c PZ |
7499 | if (tl->flags & SDTL_OVERLAP || sched_feat(FORCE_SD_OVERLAP)) |
7500 | sd->flags |= SD_OVERLAP; | |
d110235d PZ |
7501 | if (cpumask_equal(cpu_map, sched_domain_span(sd))) |
7502 | break; | |
e3589f6c | 7503 | } |
d274cb30 | 7504 | |
d069b916 PZ |
7505 | while (sd->child) |
7506 | sd = sd->child; | |
7507 | ||
21d42ccf | 7508 | *per_cpu_ptr(d.sd, i) = sd; |
dce840a0 PZ |
7509 | } |
7510 | ||
7511 | /* Build the groups for the domains */ | |
7512 | for_each_cpu(i, cpu_map) { | |
7513 | for (sd = *per_cpu_ptr(d.sd, i); sd; sd = sd->parent) { | |
7514 | sd->span_weight = cpumask_weight(sched_domain_span(sd)); | |
e3589f6c PZ |
7515 | if (sd->flags & SD_OVERLAP) { |
7516 | if (build_overlap_sched_groups(sd, i)) | |
7517 | goto error; | |
7518 | } else { | |
7519 | if (build_sched_groups(sd, i)) | |
7520 | goto error; | |
7521 | } | |
1cf51902 | 7522 | } |
a06dadbe | 7523 | } |
9c1cfda2 | 7524 | |
1da177e4 | 7525 | /* Calculate CPU power for physical packages and nodes */ |
a9c9a9b6 PZ |
7526 | for (i = nr_cpumask_bits-1; i >= 0; i--) { |
7527 | if (!cpumask_test_cpu(i, cpu_map)) | |
7528 | continue; | |
9c1cfda2 | 7529 | |
dce840a0 PZ |
7530 | for (sd = *per_cpu_ptr(d.sd, i); sd; sd = sd->parent) { |
7531 | claim_allocations(i, sd); | |
cd4ea6ae | 7532 | init_sched_groups_power(i, sd); |
dce840a0 | 7533 | } |
f712c0c7 | 7534 | } |
9c1cfda2 | 7535 | |
1da177e4 | 7536 | /* Attach the domains */ |
dce840a0 | 7537 | rcu_read_lock(); |
abcd083a | 7538 | for_each_cpu(i, cpu_map) { |
21d42ccf | 7539 | sd = *per_cpu_ptr(d.sd, i); |
49a02c51 | 7540 | cpu_attach_domain(sd, d.rd, i); |
1da177e4 | 7541 | } |
dce840a0 | 7542 | rcu_read_unlock(); |
51888ca2 | 7543 | |
822ff793 | 7544 | ret = 0; |
51888ca2 | 7545 | error: |
2109b99e | 7546 | __free_domain_allocs(&d, alloc_state, cpu_map); |
822ff793 | 7547 | return ret; |
1da177e4 | 7548 | } |
029190c5 | 7549 | |
acc3f5d7 | 7550 | static cpumask_var_t *doms_cur; /* current sched domains */ |
029190c5 | 7551 | static int ndoms_cur; /* number of sched domains in 'doms_cur' */ |
4285f594 IM |
7552 | static struct sched_domain_attr *dattr_cur; |
7553 | /* attribues of custom domains in 'doms_cur' */ | |
029190c5 PJ |
7554 | |
7555 | /* | |
7556 | * Special case: If a kmalloc of a doms_cur partition (array of | |
4212823f RR |
7557 | * cpumask) fails, then fallback to a single sched domain, |
7558 | * as determined by the single cpumask fallback_doms. | |
029190c5 | 7559 | */ |
4212823f | 7560 | static cpumask_var_t fallback_doms; |
029190c5 | 7561 | |
ee79d1bd HC |
7562 | /* |
7563 | * arch_update_cpu_topology lets virtualized architectures update the | |
7564 | * cpu core maps. It is supposed to return 1 if the topology changed | |
7565 | * or 0 if it stayed the same. | |
7566 | */ | |
7567 | int __attribute__((weak)) arch_update_cpu_topology(void) | |
22e52b07 | 7568 | { |
ee79d1bd | 7569 | return 0; |
22e52b07 HC |
7570 | } |
7571 | ||
acc3f5d7 RR |
7572 | cpumask_var_t *alloc_sched_domains(unsigned int ndoms) |
7573 | { | |
7574 | int i; | |
7575 | cpumask_var_t *doms; | |
7576 | ||
7577 | doms = kmalloc(sizeof(*doms) * ndoms, GFP_KERNEL); | |
7578 | if (!doms) | |
7579 | return NULL; | |
7580 | for (i = 0; i < ndoms; i++) { | |
7581 | if (!alloc_cpumask_var(&doms[i], GFP_KERNEL)) { | |
7582 | free_sched_domains(doms, i); | |
7583 | return NULL; | |
7584 | } | |
7585 | } | |
7586 | return doms; | |
7587 | } | |
7588 | ||
7589 | void free_sched_domains(cpumask_var_t doms[], unsigned int ndoms) | |
7590 | { | |
7591 | unsigned int i; | |
7592 | for (i = 0; i < ndoms; i++) | |
7593 | free_cpumask_var(doms[i]); | |
7594 | kfree(doms); | |
7595 | } | |
7596 | ||
1a20ff27 | 7597 | /* |
41a2d6cf | 7598 | * Set up scheduler domains and groups. Callers must hold the hotplug lock. |
029190c5 PJ |
7599 | * For now this just excludes isolated cpus, but could be used to |
7600 | * exclude other special cases in the future. | |
1a20ff27 | 7601 | */ |
c4a8849a | 7602 | static int init_sched_domains(const struct cpumask *cpu_map) |
1a20ff27 | 7603 | { |
7378547f MM |
7604 | int err; |
7605 | ||
22e52b07 | 7606 | arch_update_cpu_topology(); |
029190c5 | 7607 | ndoms_cur = 1; |
acc3f5d7 | 7608 | doms_cur = alloc_sched_domains(ndoms_cur); |
029190c5 | 7609 | if (!doms_cur) |
acc3f5d7 RR |
7610 | doms_cur = &fallback_doms; |
7611 | cpumask_andnot(doms_cur[0], cpu_map, cpu_isolated_map); | |
1d3504fc | 7612 | dattr_cur = NULL; |
dce840a0 | 7613 | err = build_sched_domains(doms_cur[0], NULL); |
6382bc90 | 7614 | register_sched_domain_sysctl(); |
7378547f MM |
7615 | |
7616 | return err; | |
1a20ff27 DG |
7617 | } |
7618 | ||
1a20ff27 DG |
7619 | /* |
7620 | * Detach sched domains from a group of cpus specified in cpu_map | |
7621 | * These cpus will now be attached to the NULL domain | |
7622 | */ | |
96f874e2 | 7623 | static void detach_destroy_domains(const struct cpumask *cpu_map) |
1a20ff27 DG |
7624 | { |
7625 | int i; | |
7626 | ||
dce840a0 | 7627 | rcu_read_lock(); |
abcd083a | 7628 | for_each_cpu(i, cpu_map) |
57d885fe | 7629 | cpu_attach_domain(NULL, &def_root_domain, i); |
dce840a0 | 7630 | rcu_read_unlock(); |
1a20ff27 DG |
7631 | } |
7632 | ||
1d3504fc HS |
7633 | /* handle null as "default" */ |
7634 | static int dattrs_equal(struct sched_domain_attr *cur, int idx_cur, | |
7635 | struct sched_domain_attr *new, int idx_new) | |
7636 | { | |
7637 | struct sched_domain_attr tmp; | |
7638 | ||
7639 | /* fast path */ | |
7640 | if (!new && !cur) | |
7641 | return 1; | |
7642 | ||
7643 | tmp = SD_ATTR_INIT; | |
7644 | return !memcmp(cur ? (cur + idx_cur) : &tmp, | |
7645 | new ? (new + idx_new) : &tmp, | |
7646 | sizeof(struct sched_domain_attr)); | |
7647 | } | |
7648 | ||
029190c5 PJ |
7649 | /* |
7650 | * Partition sched domains as specified by the 'ndoms_new' | |
41a2d6cf | 7651 | * cpumasks in the array doms_new[] of cpumasks. This compares |
029190c5 PJ |
7652 | * doms_new[] to the current sched domain partitioning, doms_cur[]. |
7653 | * It destroys each deleted domain and builds each new domain. | |
7654 | * | |
acc3f5d7 | 7655 | * 'doms_new' is an array of cpumask_var_t's of length 'ndoms_new'. |
41a2d6cf IM |
7656 | * The masks don't intersect (don't overlap.) We should setup one |
7657 | * sched domain for each mask. CPUs not in any of the cpumasks will | |
7658 | * not be load balanced. If the same cpumask appears both in the | |
029190c5 PJ |
7659 | * current 'doms_cur' domains and in the new 'doms_new', we can leave |
7660 | * it as it is. | |
7661 | * | |
acc3f5d7 RR |
7662 | * The passed in 'doms_new' should be allocated using |
7663 | * alloc_sched_domains. This routine takes ownership of it and will | |
7664 | * free_sched_domains it when done with it. If the caller failed the | |
7665 | * alloc call, then it can pass in doms_new == NULL && ndoms_new == 1, | |
7666 | * and partition_sched_domains() will fallback to the single partition | |
7667 | * 'fallback_doms', it also forces the domains to be rebuilt. | |
029190c5 | 7668 | * |
96f874e2 | 7669 | * If doms_new == NULL it will be replaced with cpu_online_mask. |
700018e0 LZ |
7670 | * ndoms_new == 0 is a special case for destroying existing domains, |
7671 | * and it will not create the default domain. | |
dfb512ec | 7672 | * |
029190c5 PJ |
7673 | * Call with hotplug lock held |
7674 | */ | |
acc3f5d7 | 7675 | void partition_sched_domains(int ndoms_new, cpumask_var_t doms_new[], |
1d3504fc | 7676 | struct sched_domain_attr *dattr_new) |
029190c5 | 7677 | { |
dfb512ec | 7678 | int i, j, n; |
d65bd5ec | 7679 | int new_topology; |
029190c5 | 7680 | |
712555ee | 7681 | mutex_lock(&sched_domains_mutex); |
a1835615 | 7682 | |
7378547f MM |
7683 | /* always unregister in case we don't destroy any domains */ |
7684 | unregister_sched_domain_sysctl(); | |
7685 | ||
d65bd5ec HC |
7686 | /* Let architecture update cpu core mappings. */ |
7687 | new_topology = arch_update_cpu_topology(); | |
7688 | ||
dfb512ec | 7689 | n = doms_new ? ndoms_new : 0; |
029190c5 PJ |
7690 | |
7691 | /* Destroy deleted domains */ | |
7692 | for (i = 0; i < ndoms_cur; i++) { | |
d65bd5ec | 7693 | for (j = 0; j < n && !new_topology; j++) { |
acc3f5d7 | 7694 | if (cpumask_equal(doms_cur[i], doms_new[j]) |
1d3504fc | 7695 | && dattrs_equal(dattr_cur, i, dattr_new, j)) |
029190c5 PJ |
7696 | goto match1; |
7697 | } | |
7698 | /* no match - a current sched domain not in new doms_new[] */ | |
acc3f5d7 | 7699 | detach_destroy_domains(doms_cur[i]); |
029190c5 PJ |
7700 | match1: |
7701 | ; | |
7702 | } | |
7703 | ||
e761b772 MK |
7704 | if (doms_new == NULL) { |
7705 | ndoms_cur = 0; | |
acc3f5d7 | 7706 | doms_new = &fallback_doms; |
6ad4c188 | 7707 | cpumask_andnot(doms_new[0], cpu_active_mask, cpu_isolated_map); |
faa2f98f | 7708 | WARN_ON_ONCE(dattr_new); |
e761b772 MK |
7709 | } |
7710 | ||
029190c5 PJ |
7711 | /* Build new domains */ |
7712 | for (i = 0; i < ndoms_new; i++) { | |
d65bd5ec | 7713 | for (j = 0; j < ndoms_cur && !new_topology; j++) { |
acc3f5d7 | 7714 | if (cpumask_equal(doms_new[i], doms_cur[j]) |
1d3504fc | 7715 | && dattrs_equal(dattr_new, i, dattr_cur, j)) |
029190c5 PJ |
7716 | goto match2; |
7717 | } | |
7718 | /* no match - add a new doms_new */ | |
dce840a0 | 7719 | build_sched_domains(doms_new[i], dattr_new ? dattr_new + i : NULL); |
029190c5 PJ |
7720 | match2: |
7721 | ; | |
7722 | } | |
7723 | ||
7724 | /* Remember the new sched domains */ | |
acc3f5d7 RR |
7725 | if (doms_cur != &fallback_doms) |
7726 | free_sched_domains(doms_cur, ndoms_cur); | |
1d3504fc | 7727 | kfree(dattr_cur); /* kfree(NULL) is safe */ |
029190c5 | 7728 | doms_cur = doms_new; |
1d3504fc | 7729 | dattr_cur = dattr_new; |
029190c5 | 7730 | ndoms_cur = ndoms_new; |
7378547f MM |
7731 | |
7732 | register_sched_domain_sysctl(); | |
a1835615 | 7733 | |
712555ee | 7734 | mutex_unlock(&sched_domains_mutex); |
029190c5 PJ |
7735 | } |
7736 | ||
5c45bf27 | 7737 | #if defined(CONFIG_SCHED_MC) || defined(CONFIG_SCHED_SMT) |
c4a8849a | 7738 | static void reinit_sched_domains(void) |
5c45bf27 | 7739 | { |
95402b38 | 7740 | get_online_cpus(); |
dfb512ec MK |
7741 | |
7742 | /* Destroy domains first to force the rebuild */ | |
7743 | partition_sched_domains(0, NULL, NULL); | |
7744 | ||
e761b772 | 7745 | rebuild_sched_domains(); |
95402b38 | 7746 | put_online_cpus(); |
5c45bf27 SS |
7747 | } |
7748 | ||
7749 | static ssize_t sched_power_savings_store(const char *buf, size_t count, int smt) | |
7750 | { | |
afb8a9b7 | 7751 | unsigned int level = 0; |
5c45bf27 | 7752 | |
afb8a9b7 GS |
7753 | if (sscanf(buf, "%u", &level) != 1) |
7754 | return -EINVAL; | |
7755 | ||
7756 | /* | |
7757 | * level is always be positive so don't check for | |
7758 | * level < POWERSAVINGS_BALANCE_NONE which is 0 | |
7759 | * What happens on 0 or 1 byte write, | |
7760 | * need to check for count as well? | |
7761 | */ | |
7762 | ||
7763 | if (level >= MAX_POWERSAVINGS_BALANCE_LEVELS) | |
5c45bf27 SS |
7764 | return -EINVAL; |
7765 | ||
7766 | if (smt) | |
afb8a9b7 | 7767 | sched_smt_power_savings = level; |
5c45bf27 | 7768 | else |
afb8a9b7 | 7769 | sched_mc_power_savings = level; |
5c45bf27 | 7770 | |
c4a8849a | 7771 | reinit_sched_domains(); |
5c45bf27 | 7772 | |
c70f22d2 | 7773 | return count; |
5c45bf27 SS |
7774 | } |
7775 | ||
5c45bf27 | 7776 | #ifdef CONFIG_SCHED_MC |
f718cd4a | 7777 | static ssize_t sched_mc_power_savings_show(struct sysdev_class *class, |
c9be0a36 | 7778 | struct sysdev_class_attribute *attr, |
f718cd4a | 7779 | char *page) |
5c45bf27 SS |
7780 | { |
7781 | return sprintf(page, "%u\n", sched_mc_power_savings); | |
7782 | } | |
f718cd4a | 7783 | static ssize_t sched_mc_power_savings_store(struct sysdev_class *class, |
c9be0a36 | 7784 | struct sysdev_class_attribute *attr, |
48f24c4d | 7785 | const char *buf, size_t count) |
5c45bf27 SS |
7786 | { |
7787 | return sched_power_savings_store(buf, count, 0); | |
7788 | } | |
f718cd4a AK |
7789 | static SYSDEV_CLASS_ATTR(sched_mc_power_savings, 0644, |
7790 | sched_mc_power_savings_show, | |
7791 | sched_mc_power_savings_store); | |
5c45bf27 SS |
7792 | #endif |
7793 | ||
7794 | #ifdef CONFIG_SCHED_SMT | |
f718cd4a | 7795 | static ssize_t sched_smt_power_savings_show(struct sysdev_class *dev, |
c9be0a36 | 7796 | struct sysdev_class_attribute *attr, |
f718cd4a | 7797 | char *page) |
5c45bf27 SS |
7798 | { |
7799 | return sprintf(page, "%u\n", sched_smt_power_savings); | |
7800 | } | |
f718cd4a | 7801 | static ssize_t sched_smt_power_savings_store(struct sysdev_class *dev, |
c9be0a36 | 7802 | struct sysdev_class_attribute *attr, |
48f24c4d | 7803 | const char *buf, size_t count) |
5c45bf27 SS |
7804 | { |
7805 | return sched_power_savings_store(buf, count, 1); | |
7806 | } | |
f718cd4a AK |
7807 | static SYSDEV_CLASS_ATTR(sched_smt_power_savings, 0644, |
7808 | sched_smt_power_savings_show, | |
6707de00 AB |
7809 | sched_smt_power_savings_store); |
7810 | #endif | |
7811 | ||
39aac648 | 7812 | int __init sched_create_sysfs_power_savings_entries(struct sysdev_class *cls) |
6707de00 AB |
7813 | { |
7814 | int err = 0; | |
7815 | ||
7816 | #ifdef CONFIG_SCHED_SMT | |
7817 | if (smt_capable()) | |
7818 | err = sysfs_create_file(&cls->kset.kobj, | |
7819 | &attr_sched_smt_power_savings.attr); | |
7820 | #endif | |
7821 | #ifdef CONFIG_SCHED_MC | |
7822 | if (!err && mc_capable()) | |
7823 | err = sysfs_create_file(&cls->kset.kobj, | |
7824 | &attr_sched_mc_power_savings.attr); | |
7825 | #endif | |
7826 | return err; | |
7827 | } | |
6d6bc0ad | 7828 | #endif /* CONFIG_SCHED_MC || CONFIG_SCHED_SMT */ |
5c45bf27 | 7829 | |
1da177e4 | 7830 | /* |
3a101d05 TH |
7831 | * Update cpusets according to cpu_active mask. If cpusets are |
7832 | * disabled, cpuset_update_active_cpus() becomes a simple wrapper | |
7833 | * around partition_sched_domains(). | |
1da177e4 | 7834 | */ |
0b2e918a TH |
7835 | static int cpuset_cpu_active(struct notifier_block *nfb, unsigned long action, |
7836 | void *hcpu) | |
e761b772 | 7837 | { |
3a101d05 | 7838 | switch (action & ~CPU_TASKS_FROZEN) { |
e761b772 | 7839 | case CPU_ONLINE: |
6ad4c188 | 7840 | case CPU_DOWN_FAILED: |
3a101d05 | 7841 | cpuset_update_active_cpus(); |
e761b772 | 7842 | return NOTIFY_OK; |
3a101d05 TH |
7843 | default: |
7844 | return NOTIFY_DONE; | |
7845 | } | |
7846 | } | |
e761b772 | 7847 | |
0b2e918a TH |
7848 | static int cpuset_cpu_inactive(struct notifier_block *nfb, unsigned long action, |
7849 | void *hcpu) | |
3a101d05 TH |
7850 | { |
7851 | switch (action & ~CPU_TASKS_FROZEN) { | |
7852 | case CPU_DOWN_PREPARE: | |
7853 | cpuset_update_active_cpus(); | |
7854 | return NOTIFY_OK; | |
e761b772 MK |
7855 | default: |
7856 | return NOTIFY_DONE; | |
7857 | } | |
7858 | } | |
e761b772 MK |
7859 | |
7860 | static int update_runtime(struct notifier_block *nfb, | |
7861 | unsigned long action, void *hcpu) | |
1da177e4 | 7862 | { |
7def2be1 PZ |
7863 | int cpu = (int)(long)hcpu; |
7864 | ||
1da177e4 | 7865 | switch (action) { |
1da177e4 | 7866 | case CPU_DOWN_PREPARE: |
8bb78442 | 7867 | case CPU_DOWN_PREPARE_FROZEN: |
7def2be1 | 7868 | disable_runtime(cpu_rq(cpu)); |
1da177e4 LT |
7869 | return NOTIFY_OK; |
7870 | ||
1da177e4 | 7871 | case CPU_DOWN_FAILED: |
8bb78442 | 7872 | case CPU_DOWN_FAILED_FROZEN: |
1da177e4 | 7873 | case CPU_ONLINE: |
8bb78442 | 7874 | case CPU_ONLINE_FROZEN: |
7def2be1 | 7875 | enable_runtime(cpu_rq(cpu)); |
e761b772 MK |
7876 | return NOTIFY_OK; |
7877 | ||
1da177e4 LT |
7878 | default: |
7879 | return NOTIFY_DONE; | |
7880 | } | |
1da177e4 | 7881 | } |
1da177e4 LT |
7882 | |
7883 | void __init sched_init_smp(void) | |
7884 | { | |
dcc30a35 RR |
7885 | cpumask_var_t non_isolated_cpus; |
7886 | ||
7887 | alloc_cpumask_var(&non_isolated_cpus, GFP_KERNEL); | |
cb5fd13f | 7888 | alloc_cpumask_var(&fallback_doms, GFP_KERNEL); |
5c1e1767 | 7889 | |
95402b38 | 7890 | get_online_cpus(); |
712555ee | 7891 | mutex_lock(&sched_domains_mutex); |
c4a8849a | 7892 | init_sched_domains(cpu_active_mask); |
dcc30a35 RR |
7893 | cpumask_andnot(non_isolated_cpus, cpu_possible_mask, cpu_isolated_map); |
7894 | if (cpumask_empty(non_isolated_cpus)) | |
7895 | cpumask_set_cpu(smp_processor_id(), non_isolated_cpus); | |
712555ee | 7896 | mutex_unlock(&sched_domains_mutex); |
95402b38 | 7897 | put_online_cpus(); |
e761b772 | 7898 | |
3a101d05 TH |
7899 | hotcpu_notifier(cpuset_cpu_active, CPU_PRI_CPUSET_ACTIVE); |
7900 | hotcpu_notifier(cpuset_cpu_inactive, CPU_PRI_CPUSET_INACTIVE); | |
e761b772 MK |
7901 | |
7902 | /* RT runtime code needs to handle some hotplug events */ | |
7903 | hotcpu_notifier(update_runtime, 0); | |
7904 | ||
b328ca18 | 7905 | init_hrtick(); |
5c1e1767 NP |
7906 | |
7907 | /* Move init over to a non-isolated CPU */ | |
dcc30a35 | 7908 | if (set_cpus_allowed_ptr(current, non_isolated_cpus) < 0) |
5c1e1767 | 7909 | BUG(); |
19978ca6 | 7910 | sched_init_granularity(); |
dcc30a35 | 7911 | free_cpumask_var(non_isolated_cpus); |
4212823f | 7912 | |
0e3900e6 | 7913 | init_sched_rt_class(); |
1da177e4 LT |
7914 | } |
7915 | #else | |
7916 | void __init sched_init_smp(void) | |
7917 | { | |
19978ca6 | 7918 | sched_init_granularity(); |
1da177e4 LT |
7919 | } |
7920 | #endif /* CONFIG_SMP */ | |
7921 | ||
cd1bb94b AB |
7922 | const_debug unsigned int sysctl_timer_migration = 1; |
7923 | ||
1da177e4 LT |
7924 | int in_sched_functions(unsigned long addr) |
7925 | { | |
1da177e4 LT |
7926 | return in_lock_functions(addr) || |
7927 | (addr >= (unsigned long)__sched_text_start | |
7928 | && addr < (unsigned long)__sched_text_end); | |
7929 | } | |
7930 | ||
acb5a9ba | 7931 | static void init_cfs_rq(struct cfs_rq *cfs_rq) |
dd41f596 IM |
7932 | { |
7933 | cfs_rq->tasks_timeline = RB_ROOT; | |
4a55bd5e | 7934 | INIT_LIST_HEAD(&cfs_rq->tasks); |
67e9fb2a | 7935 | cfs_rq->min_vruntime = (u64)(-(1LL << 20)); |
c64be78f PZ |
7936 | #ifndef CONFIG_64BIT |
7937 | cfs_rq->min_vruntime_copy = cfs_rq->min_vruntime; | |
7938 | #endif | |
dd41f596 IM |
7939 | } |
7940 | ||
fa85ae24 PZ |
7941 | static void init_rt_rq(struct rt_rq *rt_rq, struct rq *rq) |
7942 | { | |
7943 | struct rt_prio_array *array; | |
7944 | int i; | |
7945 | ||
7946 | array = &rt_rq->active; | |
7947 | for (i = 0; i < MAX_RT_PRIO; i++) { | |
7948 | INIT_LIST_HEAD(array->queue + i); | |
7949 | __clear_bit(i, array->bitmap); | |
7950 | } | |
7951 | /* delimiter for bitsearch: */ | |
7952 | __set_bit(MAX_RT_PRIO, array->bitmap); | |
7953 | ||
acb5a9ba | 7954 | #if defined CONFIG_SMP |
e864c499 GH |
7955 | rt_rq->highest_prio.curr = MAX_RT_PRIO; |
7956 | rt_rq->highest_prio.next = MAX_RT_PRIO; | |
fa85ae24 | 7957 | rt_rq->rt_nr_migratory = 0; |
fa85ae24 | 7958 | rt_rq->overloaded = 0; |
732375c6 | 7959 | plist_head_init(&rt_rq->pushable_tasks); |
fa85ae24 PZ |
7960 | #endif |
7961 | ||
7962 | rt_rq->rt_time = 0; | |
7963 | rt_rq->rt_throttled = 0; | |
ac086bc2 | 7964 | rt_rq->rt_runtime = 0; |
0986b11b | 7965 | raw_spin_lock_init(&rt_rq->rt_runtime_lock); |
fa85ae24 PZ |
7966 | } |
7967 | ||
6f505b16 | 7968 | #ifdef CONFIG_FAIR_GROUP_SCHED |
ec7dc8ac | 7969 | static void init_tg_cfs_entry(struct task_group *tg, struct cfs_rq *cfs_rq, |
3d4b47b4 | 7970 | struct sched_entity *se, int cpu, |
ec7dc8ac | 7971 | struct sched_entity *parent) |
6f505b16 | 7972 | { |
ec7dc8ac | 7973 | struct rq *rq = cpu_rq(cpu); |
acb5a9ba | 7974 | |
6f505b16 | 7975 | cfs_rq->tg = tg; |
acb5a9ba JS |
7976 | cfs_rq->rq = rq; |
7977 | #ifdef CONFIG_SMP | |
7978 | /* allow initial update_cfs_load() to truncate */ | |
7979 | cfs_rq->load_stamp = 1; | |
7980 | #endif | |
6f505b16 | 7981 | |
acb5a9ba | 7982 | tg->cfs_rq[cpu] = cfs_rq; |
6f505b16 | 7983 | tg->se[cpu] = se; |
acb5a9ba | 7984 | |
07e06b01 | 7985 | /* se could be NULL for root_task_group */ |
354d60c2 DG |
7986 | if (!se) |
7987 | return; | |
7988 | ||
ec7dc8ac DG |
7989 | if (!parent) |
7990 | se->cfs_rq = &rq->cfs; | |
7991 | else | |
7992 | se->cfs_rq = parent->my_q; | |
7993 | ||
6f505b16 | 7994 | se->my_q = cfs_rq; |
9437178f | 7995 | update_load_set(&se->load, 0); |
ec7dc8ac | 7996 | se->parent = parent; |
6f505b16 | 7997 | } |
052f1dc7 | 7998 | #endif |
6f505b16 | 7999 | |
052f1dc7 | 8000 | #ifdef CONFIG_RT_GROUP_SCHED |
ec7dc8ac | 8001 | static void init_tg_rt_entry(struct task_group *tg, struct rt_rq *rt_rq, |
3d4b47b4 | 8002 | struct sched_rt_entity *rt_se, int cpu, |
ec7dc8ac | 8003 | struct sched_rt_entity *parent) |
6f505b16 | 8004 | { |
ec7dc8ac DG |
8005 | struct rq *rq = cpu_rq(cpu); |
8006 | ||
acb5a9ba JS |
8007 | rt_rq->highest_prio.curr = MAX_RT_PRIO; |
8008 | rt_rq->rt_nr_boosted = 0; | |
8009 | rt_rq->rq = rq; | |
6f505b16 | 8010 | rt_rq->tg = tg; |
6f505b16 | 8011 | |
acb5a9ba | 8012 | tg->rt_rq[cpu] = rt_rq; |
6f505b16 | 8013 | tg->rt_se[cpu] = rt_se; |
acb5a9ba | 8014 | |
354d60c2 DG |
8015 | if (!rt_se) |
8016 | return; | |
8017 | ||
ec7dc8ac DG |
8018 | if (!parent) |
8019 | rt_se->rt_rq = &rq->rt; | |
8020 | else | |
8021 | rt_se->rt_rq = parent->my_q; | |
8022 | ||
6f505b16 | 8023 | rt_se->my_q = rt_rq; |
ec7dc8ac | 8024 | rt_se->parent = parent; |
6f505b16 PZ |
8025 | INIT_LIST_HEAD(&rt_se->run_list); |
8026 | } | |
8027 | #endif | |
8028 | ||
1da177e4 LT |
8029 | void __init sched_init(void) |
8030 | { | |
dd41f596 | 8031 | int i, j; |
434d53b0 MT |
8032 | unsigned long alloc_size = 0, ptr; |
8033 | ||
8034 | #ifdef CONFIG_FAIR_GROUP_SCHED | |
8035 | alloc_size += 2 * nr_cpu_ids * sizeof(void **); | |
8036 | #endif | |
8037 | #ifdef CONFIG_RT_GROUP_SCHED | |
8038 | alloc_size += 2 * nr_cpu_ids * sizeof(void **); | |
eff766a6 | 8039 | #endif |
df7c8e84 | 8040 | #ifdef CONFIG_CPUMASK_OFFSTACK |
8c083f08 | 8041 | alloc_size += num_possible_cpus() * cpumask_size(); |
434d53b0 | 8042 | #endif |
434d53b0 | 8043 | if (alloc_size) { |
36b7b6d4 | 8044 | ptr = (unsigned long)kzalloc(alloc_size, GFP_NOWAIT); |
434d53b0 MT |
8045 | |
8046 | #ifdef CONFIG_FAIR_GROUP_SCHED | |
07e06b01 | 8047 | root_task_group.se = (struct sched_entity **)ptr; |
434d53b0 MT |
8048 | ptr += nr_cpu_ids * sizeof(void **); |
8049 | ||
07e06b01 | 8050 | root_task_group.cfs_rq = (struct cfs_rq **)ptr; |
434d53b0 | 8051 | ptr += nr_cpu_ids * sizeof(void **); |
eff766a6 | 8052 | |
6d6bc0ad | 8053 | #endif /* CONFIG_FAIR_GROUP_SCHED */ |
434d53b0 | 8054 | #ifdef CONFIG_RT_GROUP_SCHED |
07e06b01 | 8055 | root_task_group.rt_se = (struct sched_rt_entity **)ptr; |
434d53b0 MT |
8056 | ptr += nr_cpu_ids * sizeof(void **); |
8057 | ||
07e06b01 | 8058 | root_task_group.rt_rq = (struct rt_rq **)ptr; |
eff766a6 PZ |
8059 | ptr += nr_cpu_ids * sizeof(void **); |
8060 | ||
6d6bc0ad | 8061 | #endif /* CONFIG_RT_GROUP_SCHED */ |
df7c8e84 RR |
8062 | #ifdef CONFIG_CPUMASK_OFFSTACK |
8063 | for_each_possible_cpu(i) { | |
8064 | per_cpu(load_balance_tmpmask, i) = (void *)ptr; | |
8065 | ptr += cpumask_size(); | |
8066 | } | |
8067 | #endif /* CONFIG_CPUMASK_OFFSTACK */ | |
434d53b0 | 8068 | } |
dd41f596 | 8069 | |
57d885fe GH |
8070 | #ifdef CONFIG_SMP |
8071 | init_defrootdomain(); | |
8072 | #endif | |
8073 | ||
d0b27fa7 PZ |
8074 | init_rt_bandwidth(&def_rt_bandwidth, |
8075 | global_rt_period(), global_rt_runtime()); | |
8076 | ||
8077 | #ifdef CONFIG_RT_GROUP_SCHED | |
07e06b01 | 8078 | init_rt_bandwidth(&root_task_group.rt_bandwidth, |
d0b27fa7 | 8079 | global_rt_period(), global_rt_runtime()); |
6d6bc0ad | 8080 | #endif /* CONFIG_RT_GROUP_SCHED */ |
d0b27fa7 | 8081 | |
7c941438 | 8082 | #ifdef CONFIG_CGROUP_SCHED |
07e06b01 YZ |
8083 | list_add(&root_task_group.list, &task_groups); |
8084 | INIT_LIST_HEAD(&root_task_group.children); | |
5091faa4 | 8085 | autogroup_init(&init_task); |
7c941438 | 8086 | #endif /* CONFIG_CGROUP_SCHED */ |
6f505b16 | 8087 | |
0a945022 | 8088 | for_each_possible_cpu(i) { |
70b97a7f | 8089 | struct rq *rq; |
1da177e4 LT |
8090 | |
8091 | rq = cpu_rq(i); | |
05fa785c | 8092 | raw_spin_lock_init(&rq->lock); |
7897986b | 8093 | rq->nr_running = 0; |
dce48a84 TG |
8094 | rq->calc_load_active = 0; |
8095 | rq->calc_load_update = jiffies + LOAD_FREQ; | |
acb5a9ba | 8096 | init_cfs_rq(&rq->cfs); |
6f505b16 | 8097 | init_rt_rq(&rq->rt, rq); |
dd41f596 | 8098 | #ifdef CONFIG_FAIR_GROUP_SCHED |
07e06b01 | 8099 | root_task_group.shares = root_task_group_load; |
6f505b16 | 8100 | INIT_LIST_HEAD(&rq->leaf_cfs_rq_list); |
354d60c2 | 8101 | /* |
07e06b01 | 8102 | * How much cpu bandwidth does root_task_group get? |
354d60c2 DG |
8103 | * |
8104 | * In case of task-groups formed thr' the cgroup filesystem, it | |
8105 | * gets 100% of the cpu resources in the system. This overall | |
8106 | * system cpu resource is divided among the tasks of | |
07e06b01 | 8107 | * root_task_group and its child task-groups in a fair manner, |
354d60c2 DG |
8108 | * based on each entity's (task or task-group's) weight |
8109 | * (se->load.weight). | |
8110 | * | |
07e06b01 | 8111 | * In other words, if root_task_group has 10 tasks of weight |
354d60c2 DG |
8112 | * 1024) and two child groups A0 and A1 (of weight 1024 each), |
8113 | * then A0's share of the cpu resource is: | |
8114 | * | |
0d905bca | 8115 | * A0's bandwidth = 1024 / (10*1024 + 1024 + 1024) = 8.33% |
354d60c2 | 8116 | * |
07e06b01 YZ |
8117 | * We achieve this by letting root_task_group's tasks sit |
8118 | * directly in rq->cfs (i.e root_task_group->se[] = NULL). | |
354d60c2 | 8119 | */ |
07e06b01 | 8120 | init_tg_cfs_entry(&root_task_group, &rq->cfs, NULL, i, NULL); |
354d60c2 DG |
8121 | #endif /* CONFIG_FAIR_GROUP_SCHED */ |
8122 | ||
8123 | rq->rt.rt_runtime = def_rt_bandwidth.rt_runtime; | |
052f1dc7 | 8124 | #ifdef CONFIG_RT_GROUP_SCHED |
6f505b16 | 8125 | INIT_LIST_HEAD(&rq->leaf_rt_rq_list); |
07e06b01 | 8126 | init_tg_rt_entry(&root_task_group, &rq->rt, NULL, i, NULL); |
dd41f596 | 8127 | #endif |
1da177e4 | 8128 | |
dd41f596 IM |
8129 | for (j = 0; j < CPU_LOAD_IDX_MAX; j++) |
8130 | rq->cpu_load[j] = 0; | |
fdf3e95d VP |
8131 | |
8132 | rq->last_load_update_tick = jiffies; | |
8133 | ||
1da177e4 | 8134 | #ifdef CONFIG_SMP |
41c7ce9a | 8135 | rq->sd = NULL; |
57d885fe | 8136 | rq->rd = NULL; |
1399fa78 | 8137 | rq->cpu_power = SCHED_POWER_SCALE; |
3f029d3c | 8138 | rq->post_schedule = 0; |
1da177e4 | 8139 | rq->active_balance = 0; |
dd41f596 | 8140 | rq->next_balance = jiffies; |
1da177e4 | 8141 | rq->push_cpu = 0; |
0a2966b4 | 8142 | rq->cpu = i; |
1f11eb6a | 8143 | rq->online = 0; |
eae0c9df MG |
8144 | rq->idle_stamp = 0; |
8145 | rq->avg_idle = 2*sysctl_sched_migration_cost; | |
dc938520 | 8146 | rq_attach_root(rq, &def_root_domain); |
83cd4fe2 VP |
8147 | #ifdef CONFIG_NO_HZ |
8148 | rq->nohz_balance_kick = 0; | |
8149 | init_sched_softirq_csd(&per_cpu(remote_sched_softirq_cb, i)); | |
8150 | #endif | |
1da177e4 | 8151 | #endif |
8f4d37ec | 8152 | init_rq_hrtick(rq); |
1da177e4 | 8153 | atomic_set(&rq->nr_iowait, 0); |
1da177e4 LT |
8154 | } |
8155 | ||
2dd73a4f | 8156 | set_load_weight(&init_task); |
b50f60ce | 8157 | |
e107be36 AK |
8158 | #ifdef CONFIG_PREEMPT_NOTIFIERS |
8159 | INIT_HLIST_HEAD(&init_task.preempt_notifiers); | |
8160 | #endif | |
8161 | ||
c9819f45 | 8162 | #ifdef CONFIG_SMP |
962cf36c | 8163 | open_softirq(SCHED_SOFTIRQ, run_rebalance_domains); |
c9819f45 CL |
8164 | #endif |
8165 | ||
b50f60ce | 8166 | #ifdef CONFIG_RT_MUTEXES |
732375c6 | 8167 | plist_head_init(&init_task.pi_waiters); |
b50f60ce HC |
8168 | #endif |
8169 | ||
1da177e4 LT |
8170 | /* |
8171 | * The boot idle thread does lazy MMU switching as well: | |
8172 | */ | |
8173 | atomic_inc(&init_mm.mm_count); | |
8174 | enter_lazy_tlb(&init_mm, current); | |
8175 | ||
8176 | /* | |
8177 | * Make us the idle thread. Technically, schedule() should not be | |
8178 | * called from this thread, however somewhere below it might be, | |
8179 | * but because we are the idle thread, we just pick up running again | |
8180 | * when this runqueue becomes "idle". | |
8181 | */ | |
8182 | init_idle(current, smp_processor_id()); | |
dce48a84 TG |
8183 | |
8184 | calc_load_update = jiffies + LOAD_FREQ; | |
8185 | ||
dd41f596 IM |
8186 | /* |
8187 | * During early bootup we pretend to be a normal task: | |
8188 | */ | |
8189 | current->sched_class = &fair_sched_class; | |
6892b75e | 8190 | |
6a7b3dc3 | 8191 | /* Allocate the nohz_cpu_mask if CONFIG_CPUMASK_OFFSTACK */ |
49557e62 | 8192 | zalloc_cpumask_var(&nohz_cpu_mask, GFP_NOWAIT); |
bf4d83f6 | 8193 | #ifdef CONFIG_SMP |
4cb98839 | 8194 | zalloc_cpumask_var(&sched_domains_tmpmask, GFP_NOWAIT); |
7d1e6a9b | 8195 | #ifdef CONFIG_NO_HZ |
83cd4fe2 VP |
8196 | zalloc_cpumask_var(&nohz.idle_cpus_mask, GFP_NOWAIT); |
8197 | alloc_cpumask_var(&nohz.grp_idle_mask, GFP_NOWAIT); | |
8198 | atomic_set(&nohz.load_balancer, nr_cpu_ids); | |
8199 | atomic_set(&nohz.first_pick_cpu, nr_cpu_ids); | |
8200 | atomic_set(&nohz.second_pick_cpu, nr_cpu_ids); | |
7d1e6a9b | 8201 | #endif |
bdddd296 RR |
8202 | /* May be allocated at isolcpus cmdline parse time */ |
8203 | if (cpu_isolated_map == NULL) | |
8204 | zalloc_cpumask_var(&cpu_isolated_map, GFP_NOWAIT); | |
bf4d83f6 | 8205 | #endif /* SMP */ |
6a7b3dc3 | 8206 | |
6892b75e | 8207 | scheduler_running = 1; |
1da177e4 LT |
8208 | } |
8209 | ||
d902db1e | 8210 | #ifdef CONFIG_DEBUG_ATOMIC_SLEEP |
e4aafea2 FW |
8211 | static inline int preempt_count_equals(int preempt_offset) |
8212 | { | |
234da7bc | 8213 | int nested = (preempt_count() & ~PREEMPT_ACTIVE) + rcu_preempt_depth(); |
e4aafea2 | 8214 | |
4ba8216c | 8215 | return (nested == preempt_offset); |
e4aafea2 FW |
8216 | } |
8217 | ||
d894837f | 8218 | void __might_sleep(const char *file, int line, int preempt_offset) |
1da177e4 | 8219 | { |
1da177e4 LT |
8220 | static unsigned long prev_jiffy; /* ratelimiting */ |
8221 | ||
e4aafea2 FW |
8222 | if ((preempt_count_equals(preempt_offset) && !irqs_disabled()) || |
8223 | system_state != SYSTEM_RUNNING || oops_in_progress) | |
aef745fc IM |
8224 | return; |
8225 | if (time_before(jiffies, prev_jiffy + HZ) && prev_jiffy) | |
8226 | return; | |
8227 | prev_jiffy = jiffies; | |
8228 | ||
3df0fc5b PZ |
8229 | printk(KERN_ERR |
8230 | "BUG: sleeping function called from invalid context at %s:%d\n", | |
8231 | file, line); | |
8232 | printk(KERN_ERR | |
8233 | "in_atomic(): %d, irqs_disabled(): %d, pid: %d, name: %s\n", | |
8234 | in_atomic(), irqs_disabled(), | |
8235 | current->pid, current->comm); | |
aef745fc IM |
8236 | |
8237 | debug_show_held_locks(current); | |
8238 | if (irqs_disabled()) | |
8239 | print_irqtrace_events(current); | |
8240 | dump_stack(); | |
1da177e4 LT |
8241 | } |
8242 | EXPORT_SYMBOL(__might_sleep); | |
8243 | #endif | |
8244 | ||
8245 | #ifdef CONFIG_MAGIC_SYSRQ | |
3a5e4dc1 AK |
8246 | static void normalize_task(struct rq *rq, struct task_struct *p) |
8247 | { | |
da7a735e PZ |
8248 | const struct sched_class *prev_class = p->sched_class; |
8249 | int old_prio = p->prio; | |
3a5e4dc1 | 8250 | int on_rq; |
3e51f33f | 8251 | |
fd2f4419 | 8252 | on_rq = p->on_rq; |
3a5e4dc1 AK |
8253 | if (on_rq) |
8254 | deactivate_task(rq, p, 0); | |
8255 | __setscheduler(rq, p, SCHED_NORMAL, 0); | |
8256 | if (on_rq) { | |
8257 | activate_task(rq, p, 0); | |
8258 | resched_task(rq->curr); | |
8259 | } | |
da7a735e PZ |
8260 | |
8261 | check_class_changed(rq, p, prev_class, old_prio); | |
3a5e4dc1 AK |
8262 | } |
8263 | ||
1da177e4 LT |
8264 | void normalize_rt_tasks(void) |
8265 | { | |
a0f98a1c | 8266 | struct task_struct *g, *p; |
1da177e4 | 8267 | unsigned long flags; |
70b97a7f | 8268 | struct rq *rq; |
1da177e4 | 8269 | |
4cf5d77a | 8270 | read_lock_irqsave(&tasklist_lock, flags); |
a0f98a1c | 8271 | do_each_thread(g, p) { |
178be793 IM |
8272 | /* |
8273 | * Only normalize user tasks: | |
8274 | */ | |
8275 | if (!p->mm) | |
8276 | continue; | |
8277 | ||
6cfb0d5d | 8278 | p->se.exec_start = 0; |
6cfb0d5d | 8279 | #ifdef CONFIG_SCHEDSTATS |
41acab88 LDM |
8280 | p->se.statistics.wait_start = 0; |
8281 | p->se.statistics.sleep_start = 0; | |
8282 | p->se.statistics.block_start = 0; | |
6cfb0d5d | 8283 | #endif |
dd41f596 IM |
8284 | |
8285 | if (!rt_task(p)) { | |
8286 | /* | |
8287 | * Renice negative nice level userspace | |
8288 | * tasks back to 0: | |
8289 | */ | |
8290 | if (TASK_NICE(p) < 0 && p->mm) | |
8291 | set_user_nice(p, 0); | |
1da177e4 | 8292 | continue; |
dd41f596 | 8293 | } |
1da177e4 | 8294 | |
1d615482 | 8295 | raw_spin_lock(&p->pi_lock); |
b29739f9 | 8296 | rq = __task_rq_lock(p); |
1da177e4 | 8297 | |
178be793 | 8298 | normalize_task(rq, p); |
3a5e4dc1 | 8299 | |
b29739f9 | 8300 | __task_rq_unlock(rq); |
1d615482 | 8301 | raw_spin_unlock(&p->pi_lock); |
a0f98a1c IM |
8302 | } while_each_thread(g, p); |
8303 | ||
4cf5d77a | 8304 | read_unlock_irqrestore(&tasklist_lock, flags); |
1da177e4 LT |
8305 | } |
8306 | ||
8307 | #endif /* CONFIG_MAGIC_SYSRQ */ | |
1df5c10a | 8308 | |
67fc4e0c | 8309 | #if defined(CONFIG_IA64) || defined(CONFIG_KGDB_KDB) |
1df5c10a | 8310 | /* |
67fc4e0c | 8311 | * These functions are only useful for the IA64 MCA handling, or kdb. |
1df5c10a LT |
8312 | * |
8313 | * They can only be called when the whole system has been | |
8314 | * stopped - every CPU needs to be quiescent, and no scheduling | |
8315 | * activity can take place. Using them for anything else would | |
8316 | * be a serious bug, and as a result, they aren't even visible | |
8317 | * under any other configuration. | |
8318 | */ | |
8319 | ||
8320 | /** | |
8321 | * curr_task - return the current task for a given cpu. | |
8322 | * @cpu: the processor in question. | |
8323 | * | |
8324 | * ONLY VALID WHEN THE WHOLE SYSTEM IS STOPPED! | |
8325 | */ | |
36c8b586 | 8326 | struct task_struct *curr_task(int cpu) |
1df5c10a LT |
8327 | { |
8328 | return cpu_curr(cpu); | |
8329 | } | |
8330 | ||
67fc4e0c JW |
8331 | #endif /* defined(CONFIG_IA64) || defined(CONFIG_KGDB_KDB) */ |
8332 | ||
8333 | #ifdef CONFIG_IA64 | |
1df5c10a LT |
8334 | /** |
8335 | * set_curr_task - set the current task for a given cpu. | |
8336 | * @cpu: the processor in question. | |
8337 | * @p: the task pointer to set. | |
8338 | * | |
8339 | * Description: This function must only be used when non-maskable interrupts | |
41a2d6cf IM |
8340 | * are serviced on a separate stack. It allows the architecture to switch the |
8341 | * notion of the current task on a cpu in a non-blocking manner. This function | |
1df5c10a LT |
8342 | * must be called with all CPU's synchronized, and interrupts disabled, the |
8343 | * and caller must save the original value of the current task (see | |
8344 | * curr_task() above) and restore that value before reenabling interrupts and | |
8345 | * re-starting the system. | |
8346 | * | |
8347 | * ONLY VALID WHEN THE WHOLE SYSTEM IS STOPPED! | |
8348 | */ | |
36c8b586 | 8349 | void set_curr_task(int cpu, struct task_struct *p) |
1df5c10a LT |
8350 | { |
8351 | cpu_curr(cpu) = p; | |
8352 | } | |
8353 | ||
8354 | #endif | |
29f59db3 | 8355 | |
bccbe08a PZ |
8356 | #ifdef CONFIG_FAIR_GROUP_SCHED |
8357 | static void free_fair_sched_group(struct task_group *tg) | |
6f505b16 PZ |
8358 | { |
8359 | int i; | |
8360 | ||
8361 | for_each_possible_cpu(i) { | |
8362 | if (tg->cfs_rq) | |
8363 | kfree(tg->cfs_rq[i]); | |
8364 | if (tg->se) | |
8365 | kfree(tg->se[i]); | |
6f505b16 PZ |
8366 | } |
8367 | ||
8368 | kfree(tg->cfs_rq); | |
8369 | kfree(tg->se); | |
6f505b16 PZ |
8370 | } |
8371 | ||
ec7dc8ac DG |
8372 | static |
8373 | int alloc_fair_sched_group(struct task_group *tg, struct task_group *parent) | |
29f59db3 | 8374 | { |
29f59db3 | 8375 | struct cfs_rq *cfs_rq; |
eab17229 | 8376 | struct sched_entity *se; |
29f59db3 SV |
8377 | int i; |
8378 | ||
434d53b0 | 8379 | tg->cfs_rq = kzalloc(sizeof(cfs_rq) * nr_cpu_ids, GFP_KERNEL); |
29f59db3 SV |
8380 | if (!tg->cfs_rq) |
8381 | goto err; | |
434d53b0 | 8382 | tg->se = kzalloc(sizeof(se) * nr_cpu_ids, GFP_KERNEL); |
29f59db3 SV |
8383 | if (!tg->se) |
8384 | goto err; | |
052f1dc7 PZ |
8385 | |
8386 | tg->shares = NICE_0_LOAD; | |
29f59db3 SV |
8387 | |
8388 | for_each_possible_cpu(i) { | |
eab17229 LZ |
8389 | cfs_rq = kzalloc_node(sizeof(struct cfs_rq), |
8390 | GFP_KERNEL, cpu_to_node(i)); | |
29f59db3 SV |
8391 | if (!cfs_rq) |
8392 | goto err; | |
8393 | ||
eab17229 LZ |
8394 | se = kzalloc_node(sizeof(struct sched_entity), |
8395 | GFP_KERNEL, cpu_to_node(i)); | |
29f59db3 | 8396 | if (!se) |
dfc12eb2 | 8397 | goto err_free_rq; |
29f59db3 | 8398 | |
acb5a9ba | 8399 | init_cfs_rq(cfs_rq); |
3d4b47b4 | 8400 | init_tg_cfs_entry(tg, cfs_rq, se, i, parent->se[i]); |
bccbe08a PZ |
8401 | } |
8402 | ||
8403 | return 1; | |
8404 | ||
49246274 | 8405 | err_free_rq: |
dfc12eb2 | 8406 | kfree(cfs_rq); |
49246274 | 8407 | err: |
bccbe08a PZ |
8408 | return 0; |
8409 | } | |
8410 | ||
bccbe08a PZ |
8411 | static inline void unregister_fair_sched_group(struct task_group *tg, int cpu) |
8412 | { | |
3d4b47b4 PZ |
8413 | struct rq *rq = cpu_rq(cpu); |
8414 | unsigned long flags; | |
3d4b47b4 PZ |
8415 | |
8416 | /* | |
8417 | * Only empty task groups can be destroyed; so we can speculatively | |
8418 | * check on_list without danger of it being re-added. | |
8419 | */ | |
8420 | if (!tg->cfs_rq[cpu]->on_list) | |
8421 | return; | |
8422 | ||
8423 | raw_spin_lock_irqsave(&rq->lock, flags); | |
822bc180 | 8424 | list_del_leaf_cfs_rq(tg->cfs_rq[cpu]); |
3d4b47b4 | 8425 | raw_spin_unlock_irqrestore(&rq->lock, flags); |
bccbe08a | 8426 | } |
5f817d67 | 8427 | #else /* !CONFIG_FAIR_GROUP_SCHED */ |
bccbe08a PZ |
8428 | static inline void free_fair_sched_group(struct task_group *tg) |
8429 | { | |
8430 | } | |
8431 | ||
ec7dc8ac DG |
8432 | static inline |
8433 | int alloc_fair_sched_group(struct task_group *tg, struct task_group *parent) | |
bccbe08a PZ |
8434 | { |
8435 | return 1; | |
8436 | } | |
8437 | ||
bccbe08a PZ |
8438 | static inline void unregister_fair_sched_group(struct task_group *tg, int cpu) |
8439 | { | |
8440 | } | |
6d6bc0ad | 8441 | #endif /* CONFIG_FAIR_GROUP_SCHED */ |
052f1dc7 PZ |
8442 | |
8443 | #ifdef CONFIG_RT_GROUP_SCHED | |
bccbe08a PZ |
8444 | static void free_rt_sched_group(struct task_group *tg) |
8445 | { | |
8446 | int i; | |
8447 | ||
99bc5242 BL |
8448 | if (tg->rt_se) |
8449 | destroy_rt_bandwidth(&tg->rt_bandwidth); | |
d0b27fa7 | 8450 | |
bccbe08a PZ |
8451 | for_each_possible_cpu(i) { |
8452 | if (tg->rt_rq) | |
8453 | kfree(tg->rt_rq[i]); | |
8454 | if (tg->rt_se) | |
8455 | kfree(tg->rt_se[i]); | |
8456 | } | |
8457 | ||
8458 | kfree(tg->rt_rq); | |
8459 | kfree(tg->rt_se); | |
8460 | } | |
8461 | ||
ec7dc8ac DG |
8462 | static |
8463 | int alloc_rt_sched_group(struct task_group *tg, struct task_group *parent) | |
bccbe08a PZ |
8464 | { |
8465 | struct rt_rq *rt_rq; | |
eab17229 | 8466 | struct sched_rt_entity *rt_se; |
bccbe08a PZ |
8467 | int i; |
8468 | ||
434d53b0 | 8469 | tg->rt_rq = kzalloc(sizeof(rt_rq) * nr_cpu_ids, GFP_KERNEL); |
bccbe08a PZ |
8470 | if (!tg->rt_rq) |
8471 | goto err; | |
434d53b0 | 8472 | tg->rt_se = kzalloc(sizeof(rt_se) * nr_cpu_ids, GFP_KERNEL); |
bccbe08a PZ |
8473 | if (!tg->rt_se) |
8474 | goto err; | |
8475 | ||
d0b27fa7 PZ |
8476 | init_rt_bandwidth(&tg->rt_bandwidth, |
8477 | ktime_to_ns(def_rt_bandwidth.rt_period), 0); | |
bccbe08a PZ |
8478 | |
8479 | for_each_possible_cpu(i) { | |
eab17229 LZ |
8480 | rt_rq = kzalloc_node(sizeof(struct rt_rq), |
8481 | GFP_KERNEL, cpu_to_node(i)); | |
6f505b16 PZ |
8482 | if (!rt_rq) |
8483 | goto err; | |
29f59db3 | 8484 | |
eab17229 LZ |
8485 | rt_se = kzalloc_node(sizeof(struct sched_rt_entity), |
8486 | GFP_KERNEL, cpu_to_node(i)); | |
6f505b16 | 8487 | if (!rt_se) |
dfc12eb2 | 8488 | goto err_free_rq; |
29f59db3 | 8489 | |
acb5a9ba JS |
8490 | init_rt_rq(rt_rq, cpu_rq(i)); |
8491 | rt_rq->rt_runtime = tg->rt_bandwidth.rt_runtime; | |
3d4b47b4 | 8492 | init_tg_rt_entry(tg, rt_rq, rt_se, i, parent->rt_se[i]); |
29f59db3 SV |
8493 | } |
8494 | ||
bccbe08a PZ |
8495 | return 1; |
8496 | ||
49246274 | 8497 | err_free_rq: |
dfc12eb2 | 8498 | kfree(rt_rq); |
49246274 | 8499 | err: |
bccbe08a PZ |
8500 | return 0; |
8501 | } | |
6d6bc0ad | 8502 | #else /* !CONFIG_RT_GROUP_SCHED */ |
bccbe08a PZ |
8503 | static inline void free_rt_sched_group(struct task_group *tg) |
8504 | { | |
8505 | } | |
8506 | ||
ec7dc8ac DG |
8507 | static inline |
8508 | int alloc_rt_sched_group(struct task_group *tg, struct task_group *parent) | |
bccbe08a PZ |
8509 | { |
8510 | return 1; | |
8511 | } | |
6d6bc0ad | 8512 | #endif /* CONFIG_RT_GROUP_SCHED */ |
bccbe08a | 8513 | |
7c941438 | 8514 | #ifdef CONFIG_CGROUP_SCHED |
bccbe08a PZ |
8515 | static void free_sched_group(struct task_group *tg) |
8516 | { | |
8517 | free_fair_sched_group(tg); | |
8518 | free_rt_sched_group(tg); | |
e9aa1dd1 | 8519 | autogroup_free(tg); |
bccbe08a PZ |
8520 | kfree(tg); |
8521 | } | |
8522 | ||
8523 | /* allocate runqueue etc for a new task group */ | |
ec7dc8ac | 8524 | struct task_group *sched_create_group(struct task_group *parent) |
bccbe08a PZ |
8525 | { |
8526 | struct task_group *tg; | |
8527 | unsigned long flags; | |
bccbe08a PZ |
8528 | |
8529 | tg = kzalloc(sizeof(*tg), GFP_KERNEL); | |
8530 | if (!tg) | |
8531 | return ERR_PTR(-ENOMEM); | |
8532 | ||
ec7dc8ac | 8533 | if (!alloc_fair_sched_group(tg, parent)) |
bccbe08a PZ |
8534 | goto err; |
8535 | ||
ec7dc8ac | 8536 | if (!alloc_rt_sched_group(tg, parent)) |
bccbe08a PZ |
8537 | goto err; |
8538 | ||
8ed36996 | 8539 | spin_lock_irqsave(&task_group_lock, flags); |
6f505b16 | 8540 | list_add_rcu(&tg->list, &task_groups); |
f473aa5e PZ |
8541 | |
8542 | WARN_ON(!parent); /* root should already exist */ | |
8543 | ||
8544 | tg->parent = parent; | |
f473aa5e | 8545 | INIT_LIST_HEAD(&tg->children); |
09f2724a | 8546 | list_add_rcu(&tg->siblings, &parent->children); |
8ed36996 | 8547 | spin_unlock_irqrestore(&task_group_lock, flags); |
29f59db3 | 8548 | |
9b5b7751 | 8549 | return tg; |
29f59db3 SV |
8550 | |
8551 | err: | |
6f505b16 | 8552 | free_sched_group(tg); |
29f59db3 SV |
8553 | return ERR_PTR(-ENOMEM); |
8554 | } | |
8555 | ||
9b5b7751 | 8556 | /* rcu callback to free various structures associated with a task group */ |
6f505b16 | 8557 | static void free_sched_group_rcu(struct rcu_head *rhp) |
29f59db3 | 8558 | { |
29f59db3 | 8559 | /* now it should be safe to free those cfs_rqs */ |
6f505b16 | 8560 | free_sched_group(container_of(rhp, struct task_group, rcu)); |
29f59db3 SV |
8561 | } |
8562 | ||
9b5b7751 | 8563 | /* Destroy runqueue etc associated with a task group */ |
4cf86d77 | 8564 | void sched_destroy_group(struct task_group *tg) |
29f59db3 | 8565 | { |
8ed36996 | 8566 | unsigned long flags; |
9b5b7751 | 8567 | int i; |
29f59db3 | 8568 | |
3d4b47b4 PZ |
8569 | /* end participation in shares distribution */ |
8570 | for_each_possible_cpu(i) | |
bccbe08a | 8571 | unregister_fair_sched_group(tg, i); |
3d4b47b4 PZ |
8572 | |
8573 | spin_lock_irqsave(&task_group_lock, flags); | |
6f505b16 | 8574 | list_del_rcu(&tg->list); |
f473aa5e | 8575 | list_del_rcu(&tg->siblings); |
8ed36996 | 8576 | spin_unlock_irqrestore(&task_group_lock, flags); |
9b5b7751 | 8577 | |
9b5b7751 | 8578 | /* wait for possible concurrent references to cfs_rqs complete */ |
6f505b16 | 8579 | call_rcu(&tg->rcu, free_sched_group_rcu); |
29f59db3 SV |
8580 | } |
8581 | ||
9b5b7751 | 8582 | /* change task's runqueue when it moves between groups. |
3a252015 IM |
8583 | * The caller of this function should have put the task in its new group |
8584 | * by now. This function just updates tsk->se.cfs_rq and tsk->se.parent to | |
8585 | * reflect its new group. | |
9b5b7751 SV |
8586 | */ |
8587 | void sched_move_task(struct task_struct *tsk) | |
29f59db3 SV |
8588 | { |
8589 | int on_rq, running; | |
8590 | unsigned long flags; | |
8591 | struct rq *rq; | |
8592 | ||
8593 | rq = task_rq_lock(tsk, &flags); | |
8594 | ||
051a1d1a | 8595 | running = task_current(rq, tsk); |
fd2f4419 | 8596 | on_rq = tsk->on_rq; |
29f59db3 | 8597 | |
0e1f3483 | 8598 | if (on_rq) |
29f59db3 | 8599 | dequeue_task(rq, tsk, 0); |
0e1f3483 HS |
8600 | if (unlikely(running)) |
8601 | tsk->sched_class->put_prev_task(rq, tsk); | |
29f59db3 | 8602 | |
810b3817 | 8603 | #ifdef CONFIG_FAIR_GROUP_SCHED |
b2b5ce02 PZ |
8604 | if (tsk->sched_class->task_move_group) |
8605 | tsk->sched_class->task_move_group(tsk, on_rq); | |
8606 | else | |
810b3817 | 8607 | #endif |
b2b5ce02 | 8608 | set_task_rq(tsk, task_cpu(tsk)); |
810b3817 | 8609 | |
0e1f3483 HS |
8610 | if (unlikely(running)) |
8611 | tsk->sched_class->set_curr_task(rq); | |
8612 | if (on_rq) | |
371fd7e7 | 8613 | enqueue_task(rq, tsk, 0); |
29f59db3 | 8614 | |
0122ec5b | 8615 | task_rq_unlock(rq, tsk, &flags); |
29f59db3 | 8616 | } |
7c941438 | 8617 | #endif /* CONFIG_CGROUP_SCHED */ |
29f59db3 | 8618 | |
052f1dc7 | 8619 | #ifdef CONFIG_FAIR_GROUP_SCHED |
8ed36996 PZ |
8620 | static DEFINE_MUTEX(shares_mutex); |
8621 | ||
4cf86d77 | 8622 | int sched_group_set_shares(struct task_group *tg, unsigned long shares) |
29f59db3 SV |
8623 | { |
8624 | int i; | |
8ed36996 | 8625 | unsigned long flags; |
c61935fd | 8626 | |
ec7dc8ac DG |
8627 | /* |
8628 | * We can't change the weight of the root cgroup. | |
8629 | */ | |
8630 | if (!tg->se[0]) | |
8631 | return -EINVAL; | |
8632 | ||
cd62287e | 8633 | shares = clamp(shares, scale_load(MIN_SHARES), scale_load(MAX_SHARES)); |
62fb1851 | 8634 | |
8ed36996 | 8635 | mutex_lock(&shares_mutex); |
9b5b7751 | 8636 | if (tg->shares == shares) |
5cb350ba | 8637 | goto done; |
29f59db3 | 8638 | |
9b5b7751 | 8639 | tg->shares = shares; |
c09595f6 | 8640 | for_each_possible_cpu(i) { |
9437178f PT |
8641 | struct rq *rq = cpu_rq(i); |
8642 | struct sched_entity *se; | |
8643 | ||
8644 | se = tg->se[i]; | |
8645 | /* Propagate contribution to hierarchy */ | |
8646 | raw_spin_lock_irqsave(&rq->lock, flags); | |
8647 | for_each_sched_entity(se) | |
6d5ab293 | 8648 | update_cfs_shares(group_cfs_rq(se)); |
9437178f | 8649 | raw_spin_unlock_irqrestore(&rq->lock, flags); |
c09595f6 | 8650 | } |
29f59db3 | 8651 | |
5cb350ba | 8652 | done: |
8ed36996 | 8653 | mutex_unlock(&shares_mutex); |
9b5b7751 | 8654 | return 0; |
29f59db3 SV |
8655 | } |
8656 | ||
5cb350ba DG |
8657 | unsigned long sched_group_shares(struct task_group *tg) |
8658 | { | |
8659 | return tg->shares; | |
8660 | } | |
052f1dc7 | 8661 | #endif |
5cb350ba | 8662 | |
052f1dc7 | 8663 | #ifdef CONFIG_RT_GROUP_SCHED |
6f505b16 | 8664 | /* |
9f0c1e56 | 8665 | * Ensure that the real time constraints are schedulable. |
6f505b16 | 8666 | */ |
9f0c1e56 PZ |
8667 | static DEFINE_MUTEX(rt_constraints_mutex); |
8668 | ||
8669 | static unsigned long to_ratio(u64 period, u64 runtime) | |
8670 | { | |
8671 | if (runtime == RUNTIME_INF) | |
9a7e0b18 | 8672 | return 1ULL << 20; |
9f0c1e56 | 8673 | |
9a7e0b18 | 8674 | return div64_u64(runtime << 20, period); |
9f0c1e56 PZ |
8675 | } |
8676 | ||
9a7e0b18 PZ |
8677 | /* Must be called with tasklist_lock held */ |
8678 | static inline int tg_has_rt_tasks(struct task_group *tg) | |
b40b2e8e | 8679 | { |
9a7e0b18 | 8680 | struct task_struct *g, *p; |
b40b2e8e | 8681 | |
9a7e0b18 PZ |
8682 | do_each_thread(g, p) { |
8683 | if (rt_task(p) && rt_rq_of_se(&p->rt)->tg == tg) | |
8684 | return 1; | |
8685 | } while_each_thread(g, p); | |
b40b2e8e | 8686 | |
9a7e0b18 PZ |
8687 | return 0; |
8688 | } | |
b40b2e8e | 8689 | |
9a7e0b18 PZ |
8690 | struct rt_schedulable_data { |
8691 | struct task_group *tg; | |
8692 | u64 rt_period; | |
8693 | u64 rt_runtime; | |
8694 | }; | |
b40b2e8e | 8695 | |
9a7e0b18 PZ |
8696 | static int tg_schedulable(struct task_group *tg, void *data) |
8697 | { | |
8698 | struct rt_schedulable_data *d = data; | |
8699 | struct task_group *child; | |
8700 | unsigned long total, sum = 0; | |
8701 | u64 period, runtime; | |
b40b2e8e | 8702 | |
9a7e0b18 PZ |
8703 | period = ktime_to_ns(tg->rt_bandwidth.rt_period); |
8704 | runtime = tg->rt_bandwidth.rt_runtime; | |
b40b2e8e | 8705 | |
9a7e0b18 PZ |
8706 | if (tg == d->tg) { |
8707 | period = d->rt_period; | |
8708 | runtime = d->rt_runtime; | |
b40b2e8e | 8709 | } |
b40b2e8e | 8710 | |
4653f803 PZ |
8711 | /* |
8712 | * Cannot have more runtime than the period. | |
8713 | */ | |
8714 | if (runtime > period && runtime != RUNTIME_INF) | |
8715 | return -EINVAL; | |
6f505b16 | 8716 | |
4653f803 PZ |
8717 | /* |
8718 | * Ensure we don't starve existing RT tasks. | |
8719 | */ | |
9a7e0b18 PZ |
8720 | if (rt_bandwidth_enabled() && !runtime && tg_has_rt_tasks(tg)) |
8721 | return -EBUSY; | |
6f505b16 | 8722 | |
9a7e0b18 | 8723 | total = to_ratio(period, runtime); |
6f505b16 | 8724 | |
4653f803 PZ |
8725 | /* |
8726 | * Nobody can have more than the global setting allows. | |
8727 | */ | |
8728 | if (total > to_ratio(global_rt_period(), global_rt_runtime())) | |
8729 | return -EINVAL; | |
6f505b16 | 8730 | |
4653f803 PZ |
8731 | /* |
8732 | * The sum of our children's runtime should not exceed our own. | |
8733 | */ | |
9a7e0b18 PZ |
8734 | list_for_each_entry_rcu(child, &tg->children, siblings) { |
8735 | period = ktime_to_ns(child->rt_bandwidth.rt_period); | |
8736 | runtime = child->rt_bandwidth.rt_runtime; | |
6f505b16 | 8737 | |
9a7e0b18 PZ |
8738 | if (child == d->tg) { |
8739 | period = d->rt_period; | |
8740 | runtime = d->rt_runtime; | |
8741 | } | |
6f505b16 | 8742 | |
9a7e0b18 | 8743 | sum += to_ratio(period, runtime); |
9f0c1e56 | 8744 | } |
6f505b16 | 8745 | |
9a7e0b18 PZ |
8746 | if (sum > total) |
8747 | return -EINVAL; | |
8748 | ||
8749 | return 0; | |
6f505b16 PZ |
8750 | } |
8751 | ||
9a7e0b18 | 8752 | static int __rt_schedulable(struct task_group *tg, u64 period, u64 runtime) |
521f1a24 | 8753 | { |
9a7e0b18 PZ |
8754 | struct rt_schedulable_data data = { |
8755 | .tg = tg, | |
8756 | .rt_period = period, | |
8757 | .rt_runtime = runtime, | |
8758 | }; | |
8759 | ||
8760 | return walk_tg_tree(tg_schedulable, tg_nop, &data); | |
521f1a24 DG |
8761 | } |
8762 | ||
d0b27fa7 PZ |
8763 | static int tg_set_bandwidth(struct task_group *tg, |
8764 | u64 rt_period, u64 rt_runtime) | |
6f505b16 | 8765 | { |
ac086bc2 | 8766 | int i, err = 0; |
9f0c1e56 | 8767 | |
9f0c1e56 | 8768 | mutex_lock(&rt_constraints_mutex); |
521f1a24 | 8769 | read_lock(&tasklist_lock); |
9a7e0b18 PZ |
8770 | err = __rt_schedulable(tg, rt_period, rt_runtime); |
8771 | if (err) | |
9f0c1e56 | 8772 | goto unlock; |
ac086bc2 | 8773 | |
0986b11b | 8774 | raw_spin_lock_irq(&tg->rt_bandwidth.rt_runtime_lock); |
d0b27fa7 PZ |
8775 | tg->rt_bandwidth.rt_period = ns_to_ktime(rt_period); |
8776 | tg->rt_bandwidth.rt_runtime = rt_runtime; | |
ac086bc2 PZ |
8777 | |
8778 | for_each_possible_cpu(i) { | |
8779 | struct rt_rq *rt_rq = tg->rt_rq[i]; | |
8780 | ||
0986b11b | 8781 | raw_spin_lock(&rt_rq->rt_runtime_lock); |
ac086bc2 | 8782 | rt_rq->rt_runtime = rt_runtime; |
0986b11b | 8783 | raw_spin_unlock(&rt_rq->rt_runtime_lock); |
ac086bc2 | 8784 | } |
0986b11b | 8785 | raw_spin_unlock_irq(&tg->rt_bandwidth.rt_runtime_lock); |
49246274 | 8786 | unlock: |
521f1a24 | 8787 | read_unlock(&tasklist_lock); |
9f0c1e56 PZ |
8788 | mutex_unlock(&rt_constraints_mutex); |
8789 | ||
8790 | return err; | |
6f505b16 PZ |
8791 | } |
8792 | ||
d0b27fa7 PZ |
8793 | int sched_group_set_rt_runtime(struct task_group *tg, long rt_runtime_us) |
8794 | { | |
8795 | u64 rt_runtime, rt_period; | |
8796 | ||
8797 | rt_period = ktime_to_ns(tg->rt_bandwidth.rt_period); | |
8798 | rt_runtime = (u64)rt_runtime_us * NSEC_PER_USEC; | |
8799 | if (rt_runtime_us < 0) | |
8800 | rt_runtime = RUNTIME_INF; | |
8801 | ||
8802 | return tg_set_bandwidth(tg, rt_period, rt_runtime); | |
8803 | } | |
8804 | ||
9f0c1e56 PZ |
8805 | long sched_group_rt_runtime(struct task_group *tg) |
8806 | { | |
8807 | u64 rt_runtime_us; | |
8808 | ||
d0b27fa7 | 8809 | if (tg->rt_bandwidth.rt_runtime == RUNTIME_INF) |
9f0c1e56 PZ |
8810 | return -1; |
8811 | ||
d0b27fa7 | 8812 | rt_runtime_us = tg->rt_bandwidth.rt_runtime; |
9f0c1e56 PZ |
8813 | do_div(rt_runtime_us, NSEC_PER_USEC); |
8814 | return rt_runtime_us; | |
8815 | } | |
d0b27fa7 PZ |
8816 | |
8817 | int sched_group_set_rt_period(struct task_group *tg, long rt_period_us) | |
8818 | { | |
8819 | u64 rt_runtime, rt_period; | |
8820 | ||
8821 | rt_period = (u64)rt_period_us * NSEC_PER_USEC; | |
8822 | rt_runtime = tg->rt_bandwidth.rt_runtime; | |
8823 | ||
619b0488 R |
8824 | if (rt_period == 0) |
8825 | return -EINVAL; | |
8826 | ||
d0b27fa7 PZ |
8827 | return tg_set_bandwidth(tg, rt_period, rt_runtime); |
8828 | } | |
8829 | ||
8830 | long sched_group_rt_period(struct task_group *tg) | |
8831 | { | |
8832 | u64 rt_period_us; | |
8833 | ||
8834 | rt_period_us = ktime_to_ns(tg->rt_bandwidth.rt_period); | |
8835 | do_div(rt_period_us, NSEC_PER_USEC); | |
8836 | return rt_period_us; | |
8837 | } | |
8838 | ||
8839 | static int sched_rt_global_constraints(void) | |
8840 | { | |
4653f803 | 8841 | u64 runtime, period; |
d0b27fa7 PZ |
8842 | int ret = 0; |
8843 | ||
ec5d4989 HS |
8844 | if (sysctl_sched_rt_period <= 0) |
8845 | return -EINVAL; | |
8846 | ||
4653f803 PZ |
8847 | runtime = global_rt_runtime(); |
8848 | period = global_rt_period(); | |
8849 | ||
8850 | /* | |
8851 | * Sanity check on the sysctl variables. | |
8852 | */ | |
8853 | if (runtime > period && runtime != RUNTIME_INF) | |
8854 | return -EINVAL; | |
10b612f4 | 8855 | |
d0b27fa7 | 8856 | mutex_lock(&rt_constraints_mutex); |
9a7e0b18 | 8857 | read_lock(&tasklist_lock); |
4653f803 | 8858 | ret = __rt_schedulable(NULL, 0, 0); |
9a7e0b18 | 8859 | read_unlock(&tasklist_lock); |
d0b27fa7 PZ |
8860 | mutex_unlock(&rt_constraints_mutex); |
8861 | ||
8862 | return ret; | |
8863 | } | |
54e99124 DG |
8864 | |
8865 | int sched_rt_can_attach(struct task_group *tg, struct task_struct *tsk) | |
8866 | { | |
8867 | /* Don't accept realtime tasks when there is no way for them to run */ | |
8868 | if (rt_task(tsk) && tg->rt_bandwidth.rt_runtime == 0) | |
8869 | return 0; | |
8870 | ||
8871 | return 1; | |
8872 | } | |
8873 | ||
6d6bc0ad | 8874 | #else /* !CONFIG_RT_GROUP_SCHED */ |
d0b27fa7 PZ |
8875 | static int sched_rt_global_constraints(void) |
8876 | { | |
ac086bc2 PZ |
8877 | unsigned long flags; |
8878 | int i; | |
8879 | ||
ec5d4989 HS |
8880 | if (sysctl_sched_rt_period <= 0) |
8881 | return -EINVAL; | |
8882 | ||
60aa605d PZ |
8883 | /* |
8884 | * There's always some RT tasks in the root group | |
8885 | * -- migration, kstopmachine etc.. | |
8886 | */ | |
8887 | if (sysctl_sched_rt_runtime == 0) | |
8888 | return -EBUSY; | |
8889 | ||
0986b11b | 8890 | raw_spin_lock_irqsave(&def_rt_bandwidth.rt_runtime_lock, flags); |
ac086bc2 PZ |
8891 | for_each_possible_cpu(i) { |
8892 | struct rt_rq *rt_rq = &cpu_rq(i)->rt; | |
8893 | ||
0986b11b | 8894 | raw_spin_lock(&rt_rq->rt_runtime_lock); |
ac086bc2 | 8895 | rt_rq->rt_runtime = global_rt_runtime(); |
0986b11b | 8896 | raw_spin_unlock(&rt_rq->rt_runtime_lock); |
ac086bc2 | 8897 | } |
0986b11b | 8898 | raw_spin_unlock_irqrestore(&def_rt_bandwidth.rt_runtime_lock, flags); |
ac086bc2 | 8899 | |
d0b27fa7 PZ |
8900 | return 0; |
8901 | } | |
6d6bc0ad | 8902 | #endif /* CONFIG_RT_GROUP_SCHED */ |
d0b27fa7 PZ |
8903 | |
8904 | int sched_rt_handler(struct ctl_table *table, int write, | |
8d65af78 | 8905 | void __user *buffer, size_t *lenp, |
d0b27fa7 PZ |
8906 | loff_t *ppos) |
8907 | { | |
8908 | int ret; | |
8909 | int old_period, old_runtime; | |
8910 | static DEFINE_MUTEX(mutex); | |
8911 | ||
8912 | mutex_lock(&mutex); | |
8913 | old_period = sysctl_sched_rt_period; | |
8914 | old_runtime = sysctl_sched_rt_runtime; | |
8915 | ||
8d65af78 | 8916 | ret = proc_dointvec(table, write, buffer, lenp, ppos); |
d0b27fa7 PZ |
8917 | |
8918 | if (!ret && write) { | |
8919 | ret = sched_rt_global_constraints(); | |
8920 | if (ret) { | |
8921 | sysctl_sched_rt_period = old_period; | |
8922 | sysctl_sched_rt_runtime = old_runtime; | |
8923 | } else { | |
8924 | def_rt_bandwidth.rt_runtime = global_rt_runtime(); | |
8925 | def_rt_bandwidth.rt_period = | |
8926 | ns_to_ktime(global_rt_period()); | |
8927 | } | |
8928 | } | |
8929 | mutex_unlock(&mutex); | |
8930 | ||
8931 | return ret; | |
8932 | } | |
68318b8e | 8933 | |
052f1dc7 | 8934 | #ifdef CONFIG_CGROUP_SCHED |
68318b8e SV |
8935 | |
8936 | /* return corresponding task_group object of a cgroup */ | |
2b01dfe3 | 8937 | static inline struct task_group *cgroup_tg(struct cgroup *cgrp) |
68318b8e | 8938 | { |
2b01dfe3 PM |
8939 | return container_of(cgroup_subsys_state(cgrp, cpu_cgroup_subsys_id), |
8940 | struct task_group, css); | |
68318b8e SV |
8941 | } |
8942 | ||
8943 | static struct cgroup_subsys_state * | |
2b01dfe3 | 8944 | cpu_cgroup_create(struct cgroup_subsys *ss, struct cgroup *cgrp) |
68318b8e | 8945 | { |
ec7dc8ac | 8946 | struct task_group *tg, *parent; |
68318b8e | 8947 | |
2b01dfe3 | 8948 | if (!cgrp->parent) { |
68318b8e | 8949 | /* This is early initialization for the top cgroup */ |
07e06b01 | 8950 | return &root_task_group.css; |
68318b8e SV |
8951 | } |
8952 | ||
ec7dc8ac DG |
8953 | parent = cgroup_tg(cgrp->parent); |
8954 | tg = sched_create_group(parent); | |
68318b8e SV |
8955 | if (IS_ERR(tg)) |
8956 | return ERR_PTR(-ENOMEM); | |
8957 | ||
68318b8e SV |
8958 | return &tg->css; |
8959 | } | |
8960 | ||
41a2d6cf IM |
8961 | static void |
8962 | cpu_cgroup_destroy(struct cgroup_subsys *ss, struct cgroup *cgrp) | |
68318b8e | 8963 | { |
2b01dfe3 | 8964 | struct task_group *tg = cgroup_tg(cgrp); |
68318b8e SV |
8965 | |
8966 | sched_destroy_group(tg); | |
8967 | } | |
8968 | ||
41a2d6cf | 8969 | static int |
be367d09 | 8970 | cpu_cgroup_can_attach_task(struct cgroup *cgrp, struct task_struct *tsk) |
68318b8e | 8971 | { |
b68aa230 | 8972 | #ifdef CONFIG_RT_GROUP_SCHED |
54e99124 | 8973 | if (!sched_rt_can_attach(cgroup_tg(cgrp), tsk)) |
b68aa230 PZ |
8974 | return -EINVAL; |
8975 | #else | |
68318b8e SV |
8976 | /* We don't support RT-tasks being in separate groups */ |
8977 | if (tsk->sched_class != &fair_sched_class) | |
8978 | return -EINVAL; | |
b68aa230 | 8979 | #endif |
be367d09 BB |
8980 | return 0; |
8981 | } | |
68318b8e | 8982 | |
68318b8e | 8983 | static void |
f780bdb7 | 8984 | cpu_cgroup_attach_task(struct cgroup *cgrp, struct task_struct *tsk) |
68318b8e SV |
8985 | { |
8986 | sched_move_task(tsk); | |
8987 | } | |
8988 | ||
068c5cc5 | 8989 | static void |
d41d5a01 PZ |
8990 | cpu_cgroup_exit(struct cgroup_subsys *ss, struct cgroup *cgrp, |
8991 | struct cgroup *old_cgrp, struct task_struct *task) | |
068c5cc5 PZ |
8992 | { |
8993 | /* | |
8994 | * cgroup_exit() is called in the copy_process() failure path. | |
8995 | * Ignore this case since the task hasn't ran yet, this avoids | |
8996 | * trying to poke a half freed task state from generic code. | |
8997 | */ | |
8998 | if (!(task->flags & PF_EXITING)) | |
8999 | return; | |
9000 | ||
9001 | sched_move_task(task); | |
9002 | } | |
9003 | ||
052f1dc7 | 9004 | #ifdef CONFIG_FAIR_GROUP_SCHED |
f4c753b7 | 9005 | static int cpu_shares_write_u64(struct cgroup *cgrp, struct cftype *cftype, |
2b01dfe3 | 9006 | u64 shareval) |
68318b8e | 9007 | { |
c8b28116 | 9008 | return sched_group_set_shares(cgroup_tg(cgrp), scale_load(shareval)); |
68318b8e SV |
9009 | } |
9010 | ||
f4c753b7 | 9011 | static u64 cpu_shares_read_u64(struct cgroup *cgrp, struct cftype *cft) |
68318b8e | 9012 | { |
2b01dfe3 | 9013 | struct task_group *tg = cgroup_tg(cgrp); |
68318b8e | 9014 | |
c8b28116 | 9015 | return (u64) scale_load_down(tg->shares); |
68318b8e | 9016 | } |
6d6bc0ad | 9017 | #endif /* CONFIG_FAIR_GROUP_SCHED */ |
68318b8e | 9018 | |
052f1dc7 | 9019 | #ifdef CONFIG_RT_GROUP_SCHED |
0c70814c | 9020 | static int cpu_rt_runtime_write(struct cgroup *cgrp, struct cftype *cft, |
06ecb27c | 9021 | s64 val) |
6f505b16 | 9022 | { |
06ecb27c | 9023 | return sched_group_set_rt_runtime(cgroup_tg(cgrp), val); |
6f505b16 PZ |
9024 | } |
9025 | ||
06ecb27c | 9026 | static s64 cpu_rt_runtime_read(struct cgroup *cgrp, struct cftype *cft) |
6f505b16 | 9027 | { |
06ecb27c | 9028 | return sched_group_rt_runtime(cgroup_tg(cgrp)); |
6f505b16 | 9029 | } |
d0b27fa7 PZ |
9030 | |
9031 | static int cpu_rt_period_write_uint(struct cgroup *cgrp, struct cftype *cftype, | |
9032 | u64 rt_period_us) | |
9033 | { | |
9034 | return sched_group_set_rt_period(cgroup_tg(cgrp), rt_period_us); | |
9035 | } | |
9036 | ||
9037 | static u64 cpu_rt_period_read_uint(struct cgroup *cgrp, struct cftype *cft) | |
9038 | { | |
9039 | return sched_group_rt_period(cgroup_tg(cgrp)); | |
9040 | } | |
6d6bc0ad | 9041 | #endif /* CONFIG_RT_GROUP_SCHED */ |
6f505b16 | 9042 | |
fe5c7cc2 | 9043 | static struct cftype cpu_files[] = { |
052f1dc7 | 9044 | #ifdef CONFIG_FAIR_GROUP_SCHED |
fe5c7cc2 PM |
9045 | { |
9046 | .name = "shares", | |
f4c753b7 PM |
9047 | .read_u64 = cpu_shares_read_u64, |
9048 | .write_u64 = cpu_shares_write_u64, | |
fe5c7cc2 | 9049 | }, |
052f1dc7 PZ |
9050 | #endif |
9051 | #ifdef CONFIG_RT_GROUP_SCHED | |
6f505b16 | 9052 | { |
9f0c1e56 | 9053 | .name = "rt_runtime_us", |
06ecb27c PM |
9054 | .read_s64 = cpu_rt_runtime_read, |
9055 | .write_s64 = cpu_rt_runtime_write, | |
6f505b16 | 9056 | }, |
d0b27fa7 PZ |
9057 | { |
9058 | .name = "rt_period_us", | |
f4c753b7 PM |
9059 | .read_u64 = cpu_rt_period_read_uint, |
9060 | .write_u64 = cpu_rt_period_write_uint, | |
d0b27fa7 | 9061 | }, |
052f1dc7 | 9062 | #endif |
68318b8e SV |
9063 | }; |
9064 | ||
9065 | static int cpu_cgroup_populate(struct cgroup_subsys *ss, struct cgroup *cont) | |
9066 | { | |
fe5c7cc2 | 9067 | return cgroup_add_files(cont, ss, cpu_files, ARRAY_SIZE(cpu_files)); |
68318b8e SV |
9068 | } |
9069 | ||
9070 | struct cgroup_subsys cpu_cgroup_subsys = { | |
38605cae IM |
9071 | .name = "cpu", |
9072 | .create = cpu_cgroup_create, | |
9073 | .destroy = cpu_cgroup_destroy, | |
f780bdb7 BB |
9074 | .can_attach_task = cpu_cgroup_can_attach_task, |
9075 | .attach_task = cpu_cgroup_attach_task, | |
068c5cc5 | 9076 | .exit = cpu_cgroup_exit, |
38605cae IM |
9077 | .populate = cpu_cgroup_populate, |
9078 | .subsys_id = cpu_cgroup_subsys_id, | |
68318b8e SV |
9079 | .early_init = 1, |
9080 | }; | |
9081 | ||
052f1dc7 | 9082 | #endif /* CONFIG_CGROUP_SCHED */ |
d842de87 SV |
9083 | |
9084 | #ifdef CONFIG_CGROUP_CPUACCT | |
9085 | ||
9086 | /* | |
9087 | * CPU accounting code for task groups. | |
9088 | * | |
9089 | * Based on the work by Paul Menage (menage@google.com) and Balbir Singh | |
9090 | * (balbir@in.ibm.com). | |
9091 | */ | |
9092 | ||
934352f2 | 9093 | /* track cpu usage of a group of tasks and its child groups */ |
d842de87 SV |
9094 | struct cpuacct { |
9095 | struct cgroup_subsys_state css; | |
9096 | /* cpuusage holds pointer to a u64-type object on every cpu */ | |
43cf38eb | 9097 | u64 __percpu *cpuusage; |
ef12fefa | 9098 | struct percpu_counter cpustat[CPUACCT_STAT_NSTATS]; |
934352f2 | 9099 | struct cpuacct *parent; |
d842de87 SV |
9100 | }; |
9101 | ||
9102 | struct cgroup_subsys cpuacct_subsys; | |
9103 | ||
9104 | /* return cpu accounting group corresponding to this container */ | |
32cd756a | 9105 | static inline struct cpuacct *cgroup_ca(struct cgroup *cgrp) |
d842de87 | 9106 | { |
32cd756a | 9107 | return container_of(cgroup_subsys_state(cgrp, cpuacct_subsys_id), |
d842de87 SV |
9108 | struct cpuacct, css); |
9109 | } | |
9110 | ||
9111 | /* return cpu accounting group to which this task belongs */ | |
9112 | static inline struct cpuacct *task_ca(struct task_struct *tsk) | |
9113 | { | |
9114 | return container_of(task_subsys_state(tsk, cpuacct_subsys_id), | |
9115 | struct cpuacct, css); | |
9116 | } | |
9117 | ||
9118 | /* create a new cpu accounting group */ | |
9119 | static struct cgroup_subsys_state *cpuacct_create( | |
32cd756a | 9120 | struct cgroup_subsys *ss, struct cgroup *cgrp) |
d842de87 SV |
9121 | { |
9122 | struct cpuacct *ca = kzalloc(sizeof(*ca), GFP_KERNEL); | |
ef12fefa | 9123 | int i; |
d842de87 SV |
9124 | |
9125 | if (!ca) | |
ef12fefa | 9126 | goto out; |
d842de87 SV |
9127 | |
9128 | ca->cpuusage = alloc_percpu(u64); | |
ef12fefa BR |
9129 | if (!ca->cpuusage) |
9130 | goto out_free_ca; | |
9131 | ||
9132 | for (i = 0; i < CPUACCT_STAT_NSTATS; i++) | |
9133 | if (percpu_counter_init(&ca->cpustat[i], 0)) | |
9134 | goto out_free_counters; | |
d842de87 | 9135 | |
934352f2 BR |
9136 | if (cgrp->parent) |
9137 | ca->parent = cgroup_ca(cgrp->parent); | |
9138 | ||
d842de87 | 9139 | return &ca->css; |
ef12fefa BR |
9140 | |
9141 | out_free_counters: | |
9142 | while (--i >= 0) | |
9143 | percpu_counter_destroy(&ca->cpustat[i]); | |
9144 | free_percpu(ca->cpuusage); | |
9145 | out_free_ca: | |
9146 | kfree(ca); | |
9147 | out: | |
9148 | return ERR_PTR(-ENOMEM); | |
d842de87 SV |
9149 | } |
9150 | ||
9151 | /* destroy an existing cpu accounting group */ | |
41a2d6cf | 9152 | static void |
32cd756a | 9153 | cpuacct_destroy(struct cgroup_subsys *ss, struct cgroup *cgrp) |
d842de87 | 9154 | { |
32cd756a | 9155 | struct cpuacct *ca = cgroup_ca(cgrp); |
ef12fefa | 9156 | int i; |
d842de87 | 9157 | |
ef12fefa BR |
9158 | for (i = 0; i < CPUACCT_STAT_NSTATS; i++) |
9159 | percpu_counter_destroy(&ca->cpustat[i]); | |
d842de87 SV |
9160 | free_percpu(ca->cpuusage); |
9161 | kfree(ca); | |
9162 | } | |
9163 | ||
720f5498 KC |
9164 | static u64 cpuacct_cpuusage_read(struct cpuacct *ca, int cpu) |
9165 | { | |
b36128c8 | 9166 | u64 *cpuusage = per_cpu_ptr(ca->cpuusage, cpu); |
720f5498 KC |
9167 | u64 data; |
9168 | ||
9169 | #ifndef CONFIG_64BIT | |
9170 | /* | |
9171 | * Take rq->lock to make 64-bit read safe on 32-bit platforms. | |
9172 | */ | |
05fa785c | 9173 | raw_spin_lock_irq(&cpu_rq(cpu)->lock); |
720f5498 | 9174 | data = *cpuusage; |
05fa785c | 9175 | raw_spin_unlock_irq(&cpu_rq(cpu)->lock); |
720f5498 KC |
9176 | #else |
9177 | data = *cpuusage; | |
9178 | #endif | |
9179 | ||
9180 | return data; | |
9181 | } | |
9182 | ||
9183 | static void cpuacct_cpuusage_write(struct cpuacct *ca, int cpu, u64 val) | |
9184 | { | |
b36128c8 | 9185 | u64 *cpuusage = per_cpu_ptr(ca->cpuusage, cpu); |
720f5498 KC |
9186 | |
9187 | #ifndef CONFIG_64BIT | |
9188 | /* | |
9189 | * Take rq->lock to make 64-bit write safe on 32-bit platforms. | |
9190 | */ | |
05fa785c | 9191 | raw_spin_lock_irq(&cpu_rq(cpu)->lock); |
720f5498 | 9192 | *cpuusage = val; |
05fa785c | 9193 | raw_spin_unlock_irq(&cpu_rq(cpu)->lock); |
720f5498 KC |
9194 | #else |
9195 | *cpuusage = val; | |
9196 | #endif | |
9197 | } | |
9198 | ||
d842de87 | 9199 | /* return total cpu usage (in nanoseconds) of a group */ |
32cd756a | 9200 | static u64 cpuusage_read(struct cgroup *cgrp, struct cftype *cft) |
d842de87 | 9201 | { |
32cd756a | 9202 | struct cpuacct *ca = cgroup_ca(cgrp); |
d842de87 SV |
9203 | u64 totalcpuusage = 0; |
9204 | int i; | |
9205 | ||
720f5498 KC |
9206 | for_each_present_cpu(i) |
9207 | totalcpuusage += cpuacct_cpuusage_read(ca, i); | |
d842de87 SV |
9208 | |
9209 | return totalcpuusage; | |
9210 | } | |
9211 | ||
0297b803 DG |
9212 | static int cpuusage_write(struct cgroup *cgrp, struct cftype *cftype, |
9213 | u64 reset) | |
9214 | { | |
9215 | struct cpuacct *ca = cgroup_ca(cgrp); | |
9216 | int err = 0; | |
9217 | int i; | |
9218 | ||
9219 | if (reset) { | |
9220 | err = -EINVAL; | |
9221 | goto out; | |
9222 | } | |
9223 | ||
720f5498 KC |
9224 | for_each_present_cpu(i) |
9225 | cpuacct_cpuusage_write(ca, i, 0); | |
0297b803 | 9226 | |
0297b803 DG |
9227 | out: |
9228 | return err; | |
9229 | } | |
9230 | ||
e9515c3c KC |
9231 | static int cpuacct_percpu_seq_read(struct cgroup *cgroup, struct cftype *cft, |
9232 | struct seq_file *m) | |
9233 | { | |
9234 | struct cpuacct *ca = cgroup_ca(cgroup); | |
9235 | u64 percpu; | |
9236 | int i; | |
9237 | ||
9238 | for_each_present_cpu(i) { | |
9239 | percpu = cpuacct_cpuusage_read(ca, i); | |
9240 | seq_printf(m, "%llu ", (unsigned long long) percpu); | |
9241 | } | |
9242 | seq_printf(m, "\n"); | |
9243 | return 0; | |
9244 | } | |
9245 | ||
ef12fefa BR |
9246 | static const char *cpuacct_stat_desc[] = { |
9247 | [CPUACCT_STAT_USER] = "user", | |
9248 | [CPUACCT_STAT_SYSTEM] = "system", | |
9249 | }; | |
9250 | ||
9251 | static int cpuacct_stats_show(struct cgroup *cgrp, struct cftype *cft, | |
9252 | struct cgroup_map_cb *cb) | |
9253 | { | |
9254 | struct cpuacct *ca = cgroup_ca(cgrp); | |
9255 | int i; | |
9256 | ||
9257 | for (i = 0; i < CPUACCT_STAT_NSTATS; i++) { | |
9258 | s64 val = percpu_counter_read(&ca->cpustat[i]); | |
9259 | val = cputime64_to_clock_t(val); | |
9260 | cb->fill(cb, cpuacct_stat_desc[i], val); | |
9261 | } | |
9262 | return 0; | |
9263 | } | |
9264 | ||
d842de87 SV |
9265 | static struct cftype files[] = { |
9266 | { | |
9267 | .name = "usage", | |
f4c753b7 PM |
9268 | .read_u64 = cpuusage_read, |
9269 | .write_u64 = cpuusage_write, | |
d842de87 | 9270 | }, |
e9515c3c KC |
9271 | { |
9272 | .name = "usage_percpu", | |
9273 | .read_seq_string = cpuacct_percpu_seq_read, | |
9274 | }, | |
ef12fefa BR |
9275 | { |
9276 | .name = "stat", | |
9277 | .read_map = cpuacct_stats_show, | |
9278 | }, | |
d842de87 SV |
9279 | }; |
9280 | ||
32cd756a | 9281 | static int cpuacct_populate(struct cgroup_subsys *ss, struct cgroup *cgrp) |
d842de87 | 9282 | { |
32cd756a | 9283 | return cgroup_add_files(cgrp, ss, files, ARRAY_SIZE(files)); |
d842de87 SV |
9284 | } |
9285 | ||
9286 | /* | |
9287 | * charge this task's execution time to its accounting group. | |
9288 | * | |
9289 | * called with rq->lock held. | |
9290 | */ | |
9291 | static void cpuacct_charge(struct task_struct *tsk, u64 cputime) | |
9292 | { | |
9293 | struct cpuacct *ca; | |
934352f2 | 9294 | int cpu; |
d842de87 | 9295 | |
c40c6f85 | 9296 | if (unlikely(!cpuacct_subsys.active)) |
d842de87 SV |
9297 | return; |
9298 | ||
934352f2 | 9299 | cpu = task_cpu(tsk); |
a18b83b7 BR |
9300 | |
9301 | rcu_read_lock(); | |
9302 | ||
d842de87 | 9303 | ca = task_ca(tsk); |
d842de87 | 9304 | |
934352f2 | 9305 | for (; ca; ca = ca->parent) { |
b36128c8 | 9306 | u64 *cpuusage = per_cpu_ptr(ca->cpuusage, cpu); |
d842de87 SV |
9307 | *cpuusage += cputime; |
9308 | } | |
a18b83b7 BR |
9309 | |
9310 | rcu_read_unlock(); | |
d842de87 SV |
9311 | } |
9312 | ||
fa535a77 AB |
9313 | /* |
9314 | * When CONFIG_VIRT_CPU_ACCOUNTING is enabled one jiffy can be very large | |
9315 | * in cputime_t units. As a result, cpuacct_update_stats calls | |
9316 | * percpu_counter_add with values large enough to always overflow the | |
9317 | * per cpu batch limit causing bad SMP scalability. | |
9318 | * | |
9319 | * To fix this we scale percpu_counter_batch by cputime_one_jiffy so we | |
9320 | * batch the same amount of time with CONFIG_VIRT_CPU_ACCOUNTING disabled | |
9321 | * and enabled. We cap it at INT_MAX which is the largest allowed batch value. | |
9322 | */ | |
9323 | #ifdef CONFIG_SMP | |
9324 | #define CPUACCT_BATCH \ | |
9325 | min_t(long, percpu_counter_batch * cputime_one_jiffy, INT_MAX) | |
9326 | #else | |
9327 | #define CPUACCT_BATCH 0 | |
9328 | #endif | |
9329 | ||
ef12fefa BR |
9330 | /* |
9331 | * Charge the system/user time to the task's accounting group. | |
9332 | */ | |
9333 | static void cpuacct_update_stats(struct task_struct *tsk, | |
9334 | enum cpuacct_stat_index idx, cputime_t val) | |
9335 | { | |
9336 | struct cpuacct *ca; | |
fa535a77 | 9337 | int batch = CPUACCT_BATCH; |
ef12fefa BR |
9338 | |
9339 | if (unlikely(!cpuacct_subsys.active)) | |
9340 | return; | |
9341 | ||
9342 | rcu_read_lock(); | |
9343 | ca = task_ca(tsk); | |
9344 | ||
9345 | do { | |
fa535a77 | 9346 | __percpu_counter_add(&ca->cpustat[idx], val, batch); |
ef12fefa BR |
9347 | ca = ca->parent; |
9348 | } while (ca); | |
9349 | rcu_read_unlock(); | |
9350 | } | |
9351 | ||
d842de87 SV |
9352 | struct cgroup_subsys cpuacct_subsys = { |
9353 | .name = "cpuacct", | |
9354 | .create = cpuacct_create, | |
9355 | .destroy = cpuacct_destroy, | |
9356 | .populate = cpuacct_populate, | |
9357 | .subsys_id = cpuacct_subsys_id, | |
9358 | }; | |
9359 | #endif /* CONFIG_CGROUP_CPUACCT */ | |
03b042bf | 9360 |