Commit | Line | Data |
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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 | ||
58088ad0 | 199 | static void start_bandwidth_timer(struct hrtimer *period_timer, ktime_t period) |
d0b27fa7 | 200 | { |
58088ad0 PT |
201 | unsigned long delta; |
202 | ktime_t soft, hard, now; | |
d0b27fa7 | 203 | |
58088ad0 PT |
204 | for (;;) { |
205 | if (hrtimer_active(period_timer)) | |
206 | break; | |
207 | ||
208 | now = hrtimer_cb_get_time(period_timer); | |
209 | hrtimer_forward(period_timer, now, period); | |
210 | ||
211 | soft = hrtimer_get_softexpires(period_timer); | |
212 | hard = hrtimer_get_expires(period_timer); | |
213 | delta = ktime_to_ns(ktime_sub(hard, soft)); | |
214 | __hrtimer_start_range_ns(period_timer, soft, delta, | |
215 | HRTIMER_MODE_ABS_PINNED, 0); | |
216 | } | |
217 | } | |
218 | ||
219 | static void start_rt_bandwidth(struct rt_bandwidth *rt_b) | |
220 | { | |
cac64d00 | 221 | if (!rt_bandwidth_enabled() || rt_b->rt_runtime == RUNTIME_INF) |
d0b27fa7 PZ |
222 | return; |
223 | ||
224 | if (hrtimer_active(&rt_b->rt_period_timer)) | |
225 | return; | |
226 | ||
0986b11b | 227 | raw_spin_lock(&rt_b->rt_runtime_lock); |
58088ad0 | 228 | start_bandwidth_timer(&rt_b->rt_period_timer, rt_b->rt_period); |
0986b11b | 229 | raw_spin_unlock(&rt_b->rt_runtime_lock); |
d0b27fa7 PZ |
230 | } |
231 | ||
232 | #ifdef CONFIG_RT_GROUP_SCHED | |
233 | static void destroy_rt_bandwidth(struct rt_bandwidth *rt_b) | |
234 | { | |
235 | hrtimer_cancel(&rt_b->rt_period_timer); | |
236 | } | |
237 | #endif | |
238 | ||
712555ee | 239 | /* |
c4a8849a | 240 | * sched_domains_mutex serializes calls to init_sched_domains, |
712555ee HC |
241 | * detach_destroy_domains and partition_sched_domains. |
242 | */ | |
243 | static DEFINE_MUTEX(sched_domains_mutex); | |
244 | ||
7c941438 | 245 | #ifdef CONFIG_CGROUP_SCHED |
29f59db3 | 246 | |
68318b8e SV |
247 | #include <linux/cgroup.h> |
248 | ||
29f59db3 SV |
249 | struct cfs_rq; |
250 | ||
6f505b16 PZ |
251 | static LIST_HEAD(task_groups); |
252 | ||
ab84d31e PT |
253 | struct cfs_bandwidth { |
254 | #ifdef CONFIG_CFS_BANDWIDTH | |
255 | raw_spinlock_t lock; | |
256 | ktime_t period; | |
ec12cb7f | 257 | u64 quota, runtime; |
a790de99 | 258 | s64 hierarchal_quota; |
a9cf55b2 | 259 | u64 runtime_expires; |
58088ad0 PT |
260 | |
261 | int idle, timer_active; | |
d8b4986d | 262 | struct hrtimer period_timer, slack_timer; |
85dac906 PT |
263 | struct list_head throttled_cfs_rq; |
264 | ||
e8da1b18 NR |
265 | /* statistics */ |
266 | int nr_periods, nr_throttled; | |
267 | u64 throttled_time; | |
ab84d31e PT |
268 | #endif |
269 | }; | |
270 | ||
29f59db3 | 271 | /* task group related information */ |
4cf86d77 | 272 | struct task_group { |
68318b8e | 273 | struct cgroup_subsys_state css; |
6c415b92 | 274 | |
052f1dc7 | 275 | #ifdef CONFIG_FAIR_GROUP_SCHED |
29f59db3 SV |
276 | /* schedulable entities of this group on each cpu */ |
277 | struct sched_entity **se; | |
278 | /* runqueue "owned" by this group on each cpu */ | |
279 | struct cfs_rq **cfs_rq; | |
280 | unsigned long shares; | |
2069dd75 PZ |
281 | |
282 | atomic_t load_weight; | |
052f1dc7 PZ |
283 | #endif |
284 | ||
285 | #ifdef CONFIG_RT_GROUP_SCHED | |
286 | struct sched_rt_entity **rt_se; | |
287 | struct rt_rq **rt_rq; | |
288 | ||
d0b27fa7 | 289 | struct rt_bandwidth rt_bandwidth; |
052f1dc7 | 290 | #endif |
6b2d7700 | 291 | |
ae8393e5 | 292 | struct rcu_head rcu; |
6f505b16 | 293 | struct list_head list; |
f473aa5e PZ |
294 | |
295 | struct task_group *parent; | |
296 | struct list_head siblings; | |
297 | struct list_head children; | |
5091faa4 MG |
298 | |
299 | #ifdef CONFIG_SCHED_AUTOGROUP | |
300 | struct autogroup *autogroup; | |
301 | #endif | |
ab84d31e PT |
302 | |
303 | struct cfs_bandwidth cfs_bandwidth; | |
29f59db3 SV |
304 | }; |
305 | ||
3d4b47b4 | 306 | /* task_group_lock serializes the addition/removal of task groups */ |
8ed36996 | 307 | static DEFINE_SPINLOCK(task_group_lock); |
ec2c507f | 308 | |
e9036b36 CG |
309 | #ifdef CONFIG_FAIR_GROUP_SCHED |
310 | ||
07e06b01 | 311 | # define ROOT_TASK_GROUP_LOAD NICE_0_LOAD |
052f1dc7 | 312 | |
cb4ad1ff | 313 | /* |
2e084786 LJ |
314 | * A weight of 0 or 1 can cause arithmetics problems. |
315 | * A weight of a cfs_rq is the sum of weights of which entities | |
316 | * are queued on this cfs_rq, so a weight of a entity should not be | |
317 | * too large, so as the shares value of a task group. | |
cb4ad1ff MX |
318 | * (The default weight is 1024 - so there's no practical |
319 | * limitation from this.) | |
320 | */ | |
cd62287e MG |
321 | #define MIN_SHARES (1UL << 1) |
322 | #define MAX_SHARES (1UL << 18) | |
18d95a28 | 323 | |
07e06b01 | 324 | static int root_task_group_load = ROOT_TASK_GROUP_LOAD; |
052f1dc7 PZ |
325 | #endif |
326 | ||
29f59db3 | 327 | /* Default task group. |
3a252015 | 328 | * Every task in system belong to this group at bootup. |
29f59db3 | 329 | */ |
07e06b01 | 330 | struct task_group root_task_group; |
29f59db3 | 331 | |
7c941438 | 332 | #endif /* CONFIG_CGROUP_SCHED */ |
29f59db3 | 333 | |
6aa645ea IM |
334 | /* CFS-related fields in a runqueue */ |
335 | struct cfs_rq { | |
336 | struct load_weight load; | |
953bfcd1 | 337 | unsigned long nr_running, h_nr_running; |
6aa645ea | 338 | |
6aa645ea | 339 | u64 exec_clock; |
e9acbff6 | 340 | u64 min_vruntime; |
3fe1698b PZ |
341 | #ifndef CONFIG_64BIT |
342 | u64 min_vruntime_copy; | |
343 | #endif | |
6aa645ea IM |
344 | |
345 | struct rb_root tasks_timeline; | |
346 | struct rb_node *rb_leftmost; | |
4a55bd5e PZ |
347 | |
348 | struct list_head tasks; | |
349 | struct list_head *balance_iterator; | |
350 | ||
351 | /* | |
352 | * 'curr' points to currently running entity on this cfs_rq. | |
6aa645ea IM |
353 | * It is set to NULL otherwise (i.e when none are currently running). |
354 | */ | |
ac53db59 | 355 | struct sched_entity *curr, *next, *last, *skip; |
ddc97297 | 356 | |
4934a4d3 | 357 | #ifdef CONFIG_SCHED_DEBUG |
5ac5c4d6 | 358 | unsigned int nr_spread_over; |
4934a4d3 | 359 | #endif |
ddc97297 | 360 | |
62160e3f | 361 | #ifdef CONFIG_FAIR_GROUP_SCHED |
6aa645ea IM |
362 | struct rq *rq; /* cpu runqueue to which this cfs_rq is attached */ |
363 | ||
41a2d6cf IM |
364 | /* |
365 | * leaf cfs_rqs are those that hold tasks (lowest schedulable entity in | |
6aa645ea IM |
366 | * a hierarchy). Non-leaf lrqs hold other higher schedulable entities |
367 | * (like users, containers etc.) | |
368 | * | |
369 | * leaf_cfs_rq_list ties together list of leaf cfs_rq's in a cpu. This | |
370 | * list is used during load balance. | |
371 | */ | |
3d4b47b4 | 372 | int on_list; |
41a2d6cf IM |
373 | struct list_head leaf_cfs_rq_list; |
374 | struct task_group *tg; /* group that "owns" this runqueue */ | |
c09595f6 PZ |
375 | |
376 | #ifdef CONFIG_SMP | |
c09595f6 | 377 | /* |
c8cba857 | 378 | * the part of load.weight contributed by tasks |
c09595f6 | 379 | */ |
c8cba857 | 380 | unsigned long task_weight; |
c09595f6 | 381 | |
c8cba857 PZ |
382 | /* |
383 | * h_load = weight * f(tg) | |
384 | * | |
385 | * Where f(tg) is the recursive weight fraction assigned to | |
386 | * this group. | |
387 | */ | |
388 | unsigned long h_load; | |
c09595f6 | 389 | |
c8cba857 | 390 | /* |
3b3d190e PT |
391 | * Maintaining per-cpu shares distribution for group scheduling |
392 | * | |
393 | * load_stamp is the last time we updated the load average | |
394 | * load_last is the last time we updated the load average and saw load | |
395 | * load_unacc_exec_time is currently unaccounted execution time | |
c8cba857 | 396 | */ |
2069dd75 PZ |
397 | u64 load_avg; |
398 | u64 load_period; | |
3b3d190e | 399 | u64 load_stamp, load_last, load_unacc_exec_time; |
f1d239f7 | 400 | |
2069dd75 | 401 | unsigned long load_contribution; |
c09595f6 | 402 | #endif |
ab84d31e PT |
403 | #ifdef CONFIG_CFS_BANDWIDTH |
404 | int runtime_enabled; | |
a9cf55b2 | 405 | u64 runtime_expires; |
ab84d31e | 406 | s64 runtime_remaining; |
85dac906 | 407 | |
e8da1b18 | 408 | u64 throttled_timestamp; |
64660c86 | 409 | int throttled, throttle_count; |
85dac906 | 410 | struct list_head throttled_list; |
ab84d31e | 411 | #endif |
6aa645ea IM |
412 | #endif |
413 | }; | |
1da177e4 | 414 | |
ab84d31e PT |
415 | #ifdef CONFIG_FAIR_GROUP_SCHED |
416 | #ifdef CONFIG_CFS_BANDWIDTH | |
417 | static inline struct cfs_bandwidth *tg_cfs_bandwidth(struct task_group *tg) | |
418 | { | |
419 | return &tg->cfs_bandwidth; | |
420 | } | |
421 | ||
422 | static inline u64 default_cfs_period(void); | |
58088ad0 | 423 | static int do_sched_cfs_period_timer(struct cfs_bandwidth *cfs_b, int overrun); |
d8b4986d PT |
424 | static void do_sched_cfs_slack_timer(struct cfs_bandwidth *cfs_b); |
425 | ||
426 | static enum hrtimer_restart sched_cfs_slack_timer(struct hrtimer *timer) | |
427 | { | |
428 | struct cfs_bandwidth *cfs_b = | |
429 | container_of(timer, struct cfs_bandwidth, slack_timer); | |
430 | do_sched_cfs_slack_timer(cfs_b); | |
431 | ||
432 | return HRTIMER_NORESTART; | |
433 | } | |
58088ad0 PT |
434 | |
435 | static enum hrtimer_restart sched_cfs_period_timer(struct hrtimer *timer) | |
436 | { | |
437 | struct cfs_bandwidth *cfs_b = | |
438 | container_of(timer, struct cfs_bandwidth, period_timer); | |
439 | ktime_t now; | |
440 | int overrun; | |
441 | int idle = 0; | |
442 | ||
443 | for (;;) { | |
444 | now = hrtimer_cb_get_time(timer); | |
445 | overrun = hrtimer_forward(timer, now, cfs_b->period); | |
446 | ||
447 | if (!overrun) | |
448 | break; | |
449 | ||
450 | idle = do_sched_cfs_period_timer(cfs_b, overrun); | |
451 | } | |
452 | ||
453 | return idle ? HRTIMER_NORESTART : HRTIMER_RESTART; | |
454 | } | |
ab84d31e PT |
455 | |
456 | static void init_cfs_bandwidth(struct cfs_bandwidth *cfs_b) | |
457 | { | |
458 | raw_spin_lock_init(&cfs_b->lock); | |
ec12cb7f | 459 | cfs_b->runtime = 0; |
ab84d31e PT |
460 | cfs_b->quota = RUNTIME_INF; |
461 | cfs_b->period = ns_to_ktime(default_cfs_period()); | |
58088ad0 | 462 | |
85dac906 | 463 | INIT_LIST_HEAD(&cfs_b->throttled_cfs_rq); |
58088ad0 PT |
464 | hrtimer_init(&cfs_b->period_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); |
465 | cfs_b->period_timer.function = sched_cfs_period_timer; | |
d8b4986d PT |
466 | hrtimer_init(&cfs_b->slack_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); |
467 | cfs_b->slack_timer.function = sched_cfs_slack_timer; | |
ab84d31e PT |
468 | } |
469 | ||
470 | static void init_cfs_rq_runtime(struct cfs_rq *cfs_rq) | |
471 | { | |
472 | cfs_rq->runtime_enabled = 0; | |
85dac906 | 473 | INIT_LIST_HEAD(&cfs_rq->throttled_list); |
ab84d31e PT |
474 | } |
475 | ||
58088ad0 PT |
476 | /* requires cfs_b->lock, may release to reprogram timer */ |
477 | static void __start_cfs_bandwidth(struct cfs_bandwidth *cfs_b) | |
478 | { | |
479 | /* | |
480 | * The timer may be active because we're trying to set a new bandwidth | |
481 | * period or because we're racing with the tear-down path | |
482 | * (timer_active==0 becomes visible before the hrtimer call-back | |
483 | * terminates). In either case we ensure that it's re-programmed | |
484 | */ | |
485 | while (unlikely(hrtimer_active(&cfs_b->period_timer))) { | |
486 | raw_spin_unlock(&cfs_b->lock); | |
487 | /* ensure cfs_b->lock is available while we wait */ | |
488 | hrtimer_cancel(&cfs_b->period_timer); | |
489 | ||
490 | raw_spin_lock(&cfs_b->lock); | |
491 | /* if someone else restarted the timer then we're done */ | |
492 | if (cfs_b->timer_active) | |
493 | return; | |
494 | } | |
495 | ||
496 | cfs_b->timer_active = 1; | |
497 | start_bandwidth_timer(&cfs_b->period_timer, cfs_b->period); | |
498 | } | |
499 | ||
ab84d31e | 500 | static void destroy_cfs_bandwidth(struct cfs_bandwidth *cfs_b) |
58088ad0 PT |
501 | { |
502 | hrtimer_cancel(&cfs_b->period_timer); | |
d8b4986d | 503 | hrtimer_cancel(&cfs_b->slack_timer); |
58088ad0 | 504 | } |
ab84d31e PT |
505 | #else |
506 | static void init_cfs_rq_runtime(struct cfs_rq *cfs_rq) {} | |
507 | static void init_cfs_bandwidth(struct cfs_bandwidth *cfs_b) {} | |
508 | static void destroy_cfs_bandwidth(struct cfs_bandwidth *cfs_b) {} | |
509 | ||
510 | static inline struct cfs_bandwidth *tg_cfs_bandwidth(struct task_group *tg) | |
511 | { | |
512 | return NULL; | |
513 | } | |
514 | #endif /* CONFIG_CFS_BANDWIDTH */ | |
515 | #endif /* CONFIG_FAIR_GROUP_SCHED */ | |
516 | ||
6aa645ea IM |
517 | /* Real-Time classes' related field in a runqueue: */ |
518 | struct rt_rq { | |
519 | struct rt_prio_array active; | |
63489e45 | 520 | unsigned long rt_nr_running; |
052f1dc7 | 521 | #if defined CONFIG_SMP || defined CONFIG_RT_GROUP_SCHED |
e864c499 GH |
522 | struct { |
523 | int curr; /* highest queued rt task prio */ | |
398a153b | 524 | #ifdef CONFIG_SMP |
e864c499 | 525 | int next; /* next highest */ |
398a153b | 526 | #endif |
e864c499 | 527 | } highest_prio; |
6f505b16 | 528 | #endif |
fa85ae24 | 529 | #ifdef CONFIG_SMP |
73fe6aae | 530 | unsigned long rt_nr_migratory; |
a1ba4d8b | 531 | unsigned long rt_nr_total; |
a22d7fc1 | 532 | int overloaded; |
917b627d | 533 | struct plist_head pushable_tasks; |
fa85ae24 | 534 | #endif |
6f505b16 | 535 | int rt_throttled; |
fa85ae24 | 536 | u64 rt_time; |
ac086bc2 | 537 | u64 rt_runtime; |
ea736ed5 | 538 | /* Nests inside the rq lock: */ |
0986b11b | 539 | raw_spinlock_t rt_runtime_lock; |
6f505b16 | 540 | |
052f1dc7 | 541 | #ifdef CONFIG_RT_GROUP_SCHED |
23b0fdfc PZ |
542 | unsigned long rt_nr_boosted; |
543 | ||
6f505b16 PZ |
544 | struct rq *rq; |
545 | struct list_head leaf_rt_rq_list; | |
546 | struct task_group *tg; | |
6f505b16 | 547 | #endif |
6aa645ea IM |
548 | }; |
549 | ||
57d885fe GH |
550 | #ifdef CONFIG_SMP |
551 | ||
552 | /* | |
553 | * We add the notion of a root-domain which will be used to define per-domain | |
0eab9146 IM |
554 | * variables. Each exclusive cpuset essentially defines an island domain by |
555 | * fully partitioning the member cpus from any other cpuset. Whenever a new | |
57d885fe GH |
556 | * exclusive cpuset is created, we also create and attach a new root-domain |
557 | * object. | |
558 | * | |
57d885fe GH |
559 | */ |
560 | struct root_domain { | |
561 | atomic_t refcount; | |
26a148eb | 562 | atomic_t rto_count; |
dce840a0 | 563 | struct rcu_head rcu; |
c6c4927b RR |
564 | cpumask_var_t span; |
565 | cpumask_var_t online; | |
637f5085 | 566 | |
0eab9146 | 567 | /* |
637f5085 GH |
568 | * The "RT overload" flag: it gets set if a CPU has more than |
569 | * one runnable RT task. | |
570 | */ | |
c6c4927b | 571 | cpumask_var_t rto_mask; |
6e0534f2 | 572 | struct cpupri cpupri; |
57d885fe GH |
573 | }; |
574 | ||
dc938520 GH |
575 | /* |
576 | * By default the system creates a single root-domain with all cpus as | |
577 | * members (mimicking the global state we have today). | |
578 | */ | |
57d885fe GH |
579 | static struct root_domain def_root_domain; |
580 | ||
ed2d372c | 581 | #endif /* CONFIG_SMP */ |
57d885fe | 582 | |
1da177e4 LT |
583 | /* |
584 | * This is the main, per-CPU runqueue data structure. | |
585 | * | |
586 | * Locking rule: those places that want to lock multiple runqueues | |
587 | * (such as the load balancing or the thread migration code), lock | |
588 | * acquire operations must be ordered by ascending &runqueue. | |
589 | */ | |
70b97a7f | 590 | struct rq { |
d8016491 | 591 | /* runqueue lock: */ |
05fa785c | 592 | raw_spinlock_t lock; |
1da177e4 LT |
593 | |
594 | /* | |
595 | * nr_running and cpu_load should be in the same cacheline because | |
596 | * remote CPUs use both these fields when doing load calculation. | |
597 | */ | |
598 | unsigned long nr_running; | |
6aa645ea IM |
599 | #define CPU_LOAD_IDX_MAX 5 |
600 | unsigned long cpu_load[CPU_LOAD_IDX_MAX]; | |
fdf3e95d | 601 | unsigned long last_load_update_tick; |
46cb4b7c | 602 | #ifdef CONFIG_NO_HZ |
39c0cbe2 | 603 | u64 nohz_stamp; |
83cd4fe2 | 604 | unsigned char nohz_balance_kick; |
46cb4b7c | 605 | #endif |
61eadef6 | 606 | int skip_clock_update; |
a64692a3 | 607 | |
d8016491 IM |
608 | /* capture load from *all* tasks on this cpu: */ |
609 | struct load_weight load; | |
6aa645ea IM |
610 | unsigned long nr_load_updates; |
611 | u64 nr_switches; | |
612 | ||
613 | struct cfs_rq cfs; | |
6f505b16 | 614 | struct rt_rq rt; |
6f505b16 | 615 | |
6aa645ea | 616 | #ifdef CONFIG_FAIR_GROUP_SCHED |
d8016491 IM |
617 | /* list of leaf cfs_rq on this cpu: */ |
618 | struct list_head leaf_cfs_rq_list; | |
052f1dc7 PZ |
619 | #endif |
620 | #ifdef CONFIG_RT_GROUP_SCHED | |
6f505b16 | 621 | struct list_head leaf_rt_rq_list; |
1da177e4 | 622 | #endif |
1da177e4 LT |
623 | |
624 | /* | |
625 | * This is part of a global counter where only the total sum | |
626 | * over all CPUs matters. A task can increase this counter on | |
627 | * one CPU and if it got migrated afterwards it may decrease | |
628 | * it on another CPU. Always updated under the runqueue lock: | |
629 | */ | |
630 | unsigned long nr_uninterruptible; | |
631 | ||
34f971f6 | 632 | struct task_struct *curr, *idle, *stop; |
c9819f45 | 633 | unsigned long next_balance; |
1da177e4 | 634 | struct mm_struct *prev_mm; |
6aa645ea | 635 | |
3e51f33f | 636 | u64 clock; |
305e6835 | 637 | u64 clock_task; |
6aa645ea | 638 | |
1da177e4 LT |
639 | atomic_t nr_iowait; |
640 | ||
641 | #ifdef CONFIG_SMP | |
0eab9146 | 642 | struct root_domain *rd; |
1da177e4 LT |
643 | struct sched_domain *sd; |
644 | ||
e51fd5e2 PZ |
645 | unsigned long cpu_power; |
646 | ||
a0a522ce | 647 | unsigned char idle_at_tick; |
1da177e4 | 648 | /* For active balancing */ |
3f029d3c | 649 | int post_schedule; |
1da177e4 LT |
650 | int active_balance; |
651 | int push_cpu; | |
969c7921 | 652 | struct cpu_stop_work active_balance_work; |
d8016491 IM |
653 | /* cpu of this runqueue: */ |
654 | int cpu; | |
1f11eb6a | 655 | int online; |
1da177e4 | 656 | |
e9e9250b PZ |
657 | u64 rt_avg; |
658 | u64 age_stamp; | |
1b9508f6 MG |
659 | u64 idle_stamp; |
660 | u64 avg_idle; | |
1da177e4 LT |
661 | #endif |
662 | ||
aa483808 VP |
663 | #ifdef CONFIG_IRQ_TIME_ACCOUNTING |
664 | u64 prev_irq_time; | |
665 | #endif | |
e6e6685a GC |
666 | #ifdef CONFIG_PARAVIRT |
667 | u64 prev_steal_time; | |
668 | #endif | |
095c0aa8 GC |
669 | #ifdef CONFIG_PARAVIRT_TIME_ACCOUNTING |
670 | u64 prev_steal_time_rq; | |
671 | #endif | |
aa483808 | 672 | |
dce48a84 TG |
673 | /* calc_load related fields */ |
674 | unsigned long calc_load_update; | |
675 | long calc_load_active; | |
676 | ||
8f4d37ec | 677 | #ifdef CONFIG_SCHED_HRTICK |
31656519 PZ |
678 | #ifdef CONFIG_SMP |
679 | int hrtick_csd_pending; | |
680 | struct call_single_data hrtick_csd; | |
681 | #endif | |
8f4d37ec PZ |
682 | struct hrtimer hrtick_timer; |
683 | #endif | |
684 | ||
1da177e4 LT |
685 | #ifdef CONFIG_SCHEDSTATS |
686 | /* latency stats */ | |
687 | struct sched_info rq_sched_info; | |
9c2c4802 KC |
688 | unsigned long long rq_cpu_time; |
689 | /* could above be rq->cfs_rq.exec_clock + rq->rt_rq.rt_runtime ? */ | |
1da177e4 LT |
690 | |
691 | /* sys_sched_yield() stats */ | |
480b9434 | 692 | unsigned int yld_count; |
1da177e4 LT |
693 | |
694 | /* schedule() stats */ | |
480b9434 KC |
695 | unsigned int sched_switch; |
696 | unsigned int sched_count; | |
697 | unsigned int sched_goidle; | |
1da177e4 LT |
698 | |
699 | /* try_to_wake_up() stats */ | |
480b9434 KC |
700 | unsigned int ttwu_count; |
701 | unsigned int ttwu_local; | |
1da177e4 | 702 | #endif |
317f3941 PZ |
703 | |
704 | #ifdef CONFIG_SMP | |
fa14ff4a | 705 | struct llist_head wake_list; |
317f3941 | 706 | #endif |
1da177e4 LT |
707 | }; |
708 | ||
f34e3b61 | 709 | static DEFINE_PER_CPU_SHARED_ALIGNED(struct rq, runqueues); |
1da177e4 | 710 | |
a64692a3 | 711 | |
1e5a7405 | 712 | static void check_preempt_curr(struct rq *rq, struct task_struct *p, int flags); |
dd41f596 | 713 | |
0a2966b4 CL |
714 | static inline int cpu_of(struct rq *rq) |
715 | { | |
716 | #ifdef CONFIG_SMP | |
717 | return rq->cpu; | |
718 | #else | |
719 | return 0; | |
720 | #endif | |
721 | } | |
722 | ||
497f0ab3 | 723 | #define rcu_dereference_check_sched_domain(p) \ |
d11c563d | 724 | rcu_dereference_check((p), \ |
d11c563d PM |
725 | lockdep_is_held(&sched_domains_mutex)) |
726 | ||
674311d5 NP |
727 | /* |
728 | * The domain tree (rq->sd) is protected by RCU's quiescent state transition. | |
1a20ff27 | 729 | * See detach_destroy_domains: synchronize_sched for details. |
674311d5 NP |
730 | * |
731 | * The domain tree of any CPU may only be accessed from within | |
732 | * preempt-disabled sections. | |
733 | */ | |
48f24c4d | 734 | #define for_each_domain(cpu, __sd) \ |
497f0ab3 | 735 | for (__sd = rcu_dereference_check_sched_domain(cpu_rq(cpu)->sd); __sd; __sd = __sd->parent) |
1da177e4 LT |
736 | |
737 | #define cpu_rq(cpu) (&per_cpu(runqueues, (cpu))) | |
738 | #define this_rq() (&__get_cpu_var(runqueues)) | |
739 | #define task_rq(p) cpu_rq(task_cpu(p)) | |
740 | #define cpu_curr(cpu) (cpu_rq(cpu)->curr) | |
54d35f29 | 741 | #define raw_rq() (&__raw_get_cpu_var(runqueues)) |
1da177e4 | 742 | |
dc61b1d6 PZ |
743 | #ifdef CONFIG_CGROUP_SCHED |
744 | ||
745 | /* | |
746 | * Return the group to which this tasks belongs. | |
747 | * | |
6c6c54e1 PZ |
748 | * We use task_subsys_state_check() and extend the RCU verification with |
749 | * pi->lock and rq->lock because cpu_cgroup_attach() holds those locks for each | |
750 | * task it moves into the cgroup. Therefore by holding either of those locks, | |
751 | * we pin the task to the current cgroup. | |
dc61b1d6 PZ |
752 | */ |
753 | static inline struct task_group *task_group(struct task_struct *p) | |
754 | { | |
5091faa4 | 755 | struct task_group *tg; |
dc61b1d6 PZ |
756 | struct cgroup_subsys_state *css; |
757 | ||
758 | css = task_subsys_state_check(p, cpu_cgroup_subsys_id, | |
6c6c54e1 PZ |
759 | lockdep_is_held(&p->pi_lock) || |
760 | lockdep_is_held(&task_rq(p)->lock)); | |
5091faa4 MG |
761 | tg = container_of(css, struct task_group, css); |
762 | ||
763 | return autogroup_task_group(p, tg); | |
dc61b1d6 PZ |
764 | } |
765 | ||
766 | /* Change a task's cfs_rq and parent entity if it moves across CPUs/groups */ | |
767 | static inline void set_task_rq(struct task_struct *p, unsigned int cpu) | |
768 | { | |
769 | #ifdef CONFIG_FAIR_GROUP_SCHED | |
770 | p->se.cfs_rq = task_group(p)->cfs_rq[cpu]; | |
771 | p->se.parent = task_group(p)->se[cpu]; | |
772 | #endif | |
773 | ||
774 | #ifdef CONFIG_RT_GROUP_SCHED | |
775 | p->rt.rt_rq = task_group(p)->rt_rq[cpu]; | |
776 | p->rt.parent = task_group(p)->rt_se[cpu]; | |
777 | #endif | |
778 | } | |
779 | ||
780 | #else /* CONFIG_CGROUP_SCHED */ | |
781 | ||
782 | static inline void set_task_rq(struct task_struct *p, unsigned int cpu) { } | |
783 | static inline struct task_group *task_group(struct task_struct *p) | |
784 | { | |
785 | return NULL; | |
786 | } | |
787 | ||
788 | #endif /* CONFIG_CGROUP_SCHED */ | |
789 | ||
fe44d621 | 790 | static void update_rq_clock_task(struct rq *rq, s64 delta); |
305e6835 | 791 | |
fe44d621 | 792 | static void update_rq_clock(struct rq *rq) |
3e51f33f | 793 | { |
fe44d621 | 794 | s64 delta; |
305e6835 | 795 | |
61eadef6 | 796 | if (rq->skip_clock_update > 0) |
f26f9aff | 797 | return; |
aa483808 | 798 | |
fe44d621 PZ |
799 | delta = sched_clock_cpu(cpu_of(rq)) - rq->clock; |
800 | rq->clock += delta; | |
801 | update_rq_clock_task(rq, delta); | |
3e51f33f PZ |
802 | } |
803 | ||
bf5c91ba IM |
804 | /* |
805 | * Tunables that become constants when CONFIG_SCHED_DEBUG is off: | |
806 | */ | |
807 | #ifdef CONFIG_SCHED_DEBUG | |
808 | # define const_debug __read_mostly | |
809 | #else | |
810 | # define const_debug static const | |
811 | #endif | |
812 | ||
017730c1 | 813 | /** |
1fd06bb1 | 814 | * runqueue_is_locked - Returns true if the current cpu runqueue is locked |
e17b38bf | 815 | * @cpu: the processor in question. |
017730c1 | 816 | * |
017730c1 IM |
817 | * This interface allows printk to be called with the runqueue lock |
818 | * held and know whether or not it is OK to wake up the klogd. | |
819 | */ | |
89f19f04 | 820 | int runqueue_is_locked(int cpu) |
017730c1 | 821 | { |
05fa785c | 822 | return raw_spin_is_locked(&cpu_rq(cpu)->lock); |
017730c1 IM |
823 | } |
824 | ||
bf5c91ba IM |
825 | /* |
826 | * Debugging: various feature bits | |
827 | */ | |
f00b45c1 PZ |
828 | |
829 | #define SCHED_FEAT(name, enabled) \ | |
830 | __SCHED_FEAT_##name , | |
831 | ||
bf5c91ba | 832 | enum { |
f00b45c1 | 833 | #include "sched_features.h" |
bf5c91ba IM |
834 | }; |
835 | ||
f00b45c1 PZ |
836 | #undef SCHED_FEAT |
837 | ||
838 | #define SCHED_FEAT(name, enabled) \ | |
839 | (1UL << __SCHED_FEAT_##name) * enabled | | |
840 | ||
bf5c91ba | 841 | const_debug unsigned int sysctl_sched_features = |
f00b45c1 PZ |
842 | #include "sched_features.h" |
843 | 0; | |
844 | ||
845 | #undef SCHED_FEAT | |
846 | ||
847 | #ifdef CONFIG_SCHED_DEBUG | |
848 | #define SCHED_FEAT(name, enabled) \ | |
849 | #name , | |
850 | ||
983ed7a6 | 851 | static __read_mostly char *sched_feat_names[] = { |
f00b45c1 PZ |
852 | #include "sched_features.h" |
853 | NULL | |
854 | }; | |
855 | ||
856 | #undef SCHED_FEAT | |
857 | ||
34f3a814 | 858 | static int sched_feat_show(struct seq_file *m, void *v) |
f00b45c1 | 859 | { |
f00b45c1 PZ |
860 | int i; |
861 | ||
862 | for (i = 0; sched_feat_names[i]; i++) { | |
34f3a814 LZ |
863 | if (!(sysctl_sched_features & (1UL << i))) |
864 | seq_puts(m, "NO_"); | |
865 | seq_printf(m, "%s ", sched_feat_names[i]); | |
f00b45c1 | 866 | } |
34f3a814 | 867 | seq_puts(m, "\n"); |
f00b45c1 | 868 | |
34f3a814 | 869 | return 0; |
f00b45c1 PZ |
870 | } |
871 | ||
872 | static ssize_t | |
873 | sched_feat_write(struct file *filp, const char __user *ubuf, | |
874 | size_t cnt, loff_t *ppos) | |
875 | { | |
876 | char buf[64]; | |
7740191c | 877 | char *cmp; |
f00b45c1 PZ |
878 | int neg = 0; |
879 | int i; | |
880 | ||
881 | if (cnt > 63) | |
882 | cnt = 63; | |
883 | ||
884 | if (copy_from_user(&buf, ubuf, cnt)) | |
885 | return -EFAULT; | |
886 | ||
887 | buf[cnt] = 0; | |
7740191c | 888 | cmp = strstrip(buf); |
f00b45c1 | 889 | |
524429c3 | 890 | if (strncmp(cmp, "NO_", 3) == 0) { |
f00b45c1 PZ |
891 | neg = 1; |
892 | cmp += 3; | |
893 | } | |
894 | ||
895 | for (i = 0; sched_feat_names[i]; i++) { | |
7740191c | 896 | if (strcmp(cmp, sched_feat_names[i]) == 0) { |
f00b45c1 PZ |
897 | if (neg) |
898 | sysctl_sched_features &= ~(1UL << i); | |
899 | else | |
900 | sysctl_sched_features |= (1UL << i); | |
901 | break; | |
902 | } | |
903 | } | |
904 | ||
905 | if (!sched_feat_names[i]) | |
906 | return -EINVAL; | |
907 | ||
42994724 | 908 | *ppos += cnt; |
f00b45c1 PZ |
909 | |
910 | return cnt; | |
911 | } | |
912 | ||
34f3a814 LZ |
913 | static int sched_feat_open(struct inode *inode, struct file *filp) |
914 | { | |
915 | return single_open(filp, sched_feat_show, NULL); | |
916 | } | |
917 | ||
828c0950 | 918 | static const struct file_operations sched_feat_fops = { |
34f3a814 LZ |
919 | .open = sched_feat_open, |
920 | .write = sched_feat_write, | |
921 | .read = seq_read, | |
922 | .llseek = seq_lseek, | |
923 | .release = single_release, | |
f00b45c1 PZ |
924 | }; |
925 | ||
926 | static __init int sched_init_debug(void) | |
927 | { | |
f00b45c1 PZ |
928 | debugfs_create_file("sched_features", 0644, NULL, NULL, |
929 | &sched_feat_fops); | |
930 | ||
931 | return 0; | |
932 | } | |
933 | late_initcall(sched_init_debug); | |
934 | ||
935 | #endif | |
936 | ||
937 | #define sched_feat(x) (sysctl_sched_features & (1UL << __SCHED_FEAT_##x)) | |
bf5c91ba | 938 | |
b82d9fdd PZ |
939 | /* |
940 | * Number of tasks to iterate in a single balance run. | |
941 | * Limited because this is done with IRQs disabled. | |
942 | */ | |
943 | const_debug unsigned int sysctl_sched_nr_migrate = 32; | |
944 | ||
e9e9250b PZ |
945 | /* |
946 | * period over which we average the RT time consumption, measured | |
947 | * in ms. | |
948 | * | |
949 | * default: 1s | |
950 | */ | |
951 | const_debug unsigned int sysctl_sched_time_avg = MSEC_PER_SEC; | |
952 | ||
fa85ae24 | 953 | /* |
9f0c1e56 | 954 | * period over which we measure -rt task cpu usage in us. |
fa85ae24 PZ |
955 | * default: 1s |
956 | */ | |
9f0c1e56 | 957 | unsigned int sysctl_sched_rt_period = 1000000; |
fa85ae24 | 958 | |
6892b75e IM |
959 | static __read_mostly int scheduler_running; |
960 | ||
9f0c1e56 PZ |
961 | /* |
962 | * part of the period that we allow rt tasks to run in us. | |
963 | * default: 0.95s | |
964 | */ | |
965 | int sysctl_sched_rt_runtime = 950000; | |
fa85ae24 | 966 | |
d0b27fa7 PZ |
967 | static inline u64 global_rt_period(void) |
968 | { | |
969 | return (u64)sysctl_sched_rt_period * NSEC_PER_USEC; | |
970 | } | |
971 | ||
972 | static inline u64 global_rt_runtime(void) | |
973 | { | |
e26873bb | 974 | if (sysctl_sched_rt_runtime < 0) |
d0b27fa7 PZ |
975 | return RUNTIME_INF; |
976 | ||
977 | return (u64)sysctl_sched_rt_runtime * NSEC_PER_USEC; | |
978 | } | |
fa85ae24 | 979 | |
1da177e4 | 980 | #ifndef prepare_arch_switch |
4866cde0 NP |
981 | # define prepare_arch_switch(next) do { } while (0) |
982 | #endif | |
983 | #ifndef finish_arch_switch | |
984 | # define finish_arch_switch(prev) do { } while (0) | |
985 | #endif | |
986 | ||
051a1d1a DA |
987 | static inline int task_current(struct rq *rq, struct task_struct *p) |
988 | { | |
989 | return rq->curr == p; | |
990 | } | |
991 | ||
70b97a7f | 992 | static inline int task_running(struct rq *rq, struct task_struct *p) |
4866cde0 | 993 | { |
3ca7a440 PZ |
994 | #ifdef CONFIG_SMP |
995 | return p->on_cpu; | |
996 | #else | |
051a1d1a | 997 | return task_current(rq, p); |
3ca7a440 | 998 | #endif |
4866cde0 NP |
999 | } |
1000 | ||
3ca7a440 | 1001 | #ifndef __ARCH_WANT_UNLOCKED_CTXSW |
70b97a7f | 1002 | static inline void prepare_lock_switch(struct rq *rq, struct task_struct *next) |
4866cde0 | 1003 | { |
3ca7a440 PZ |
1004 | #ifdef CONFIG_SMP |
1005 | /* | |
1006 | * We can optimise this out completely for !SMP, because the | |
1007 | * SMP rebalancing from interrupt is the only thing that cares | |
1008 | * here. | |
1009 | */ | |
1010 | next->on_cpu = 1; | |
1011 | #endif | |
4866cde0 NP |
1012 | } |
1013 | ||
70b97a7f | 1014 | static inline void finish_lock_switch(struct rq *rq, struct task_struct *prev) |
4866cde0 | 1015 | { |
3ca7a440 PZ |
1016 | #ifdef CONFIG_SMP |
1017 | /* | |
1018 | * After ->on_cpu is cleared, the task can be moved to a different CPU. | |
1019 | * We must ensure this doesn't happen until the switch is completely | |
1020 | * finished. | |
1021 | */ | |
1022 | smp_wmb(); | |
1023 | prev->on_cpu = 0; | |
1024 | #endif | |
da04c035 IM |
1025 | #ifdef CONFIG_DEBUG_SPINLOCK |
1026 | /* this is a valid case when another task releases the spinlock */ | |
1027 | rq->lock.owner = current; | |
1028 | #endif | |
8a25d5de IM |
1029 | /* |
1030 | * If we are tracking spinlock dependencies then we have to | |
1031 | * fix up the runqueue lock - which gets 'carried over' from | |
1032 | * prev into current: | |
1033 | */ | |
1034 | spin_acquire(&rq->lock.dep_map, 0, 0, _THIS_IP_); | |
1035 | ||
05fa785c | 1036 | raw_spin_unlock_irq(&rq->lock); |
4866cde0 NP |
1037 | } |
1038 | ||
1039 | #else /* __ARCH_WANT_UNLOCKED_CTXSW */ | |
70b97a7f | 1040 | static inline void prepare_lock_switch(struct rq *rq, struct task_struct *next) |
4866cde0 NP |
1041 | { |
1042 | #ifdef CONFIG_SMP | |
1043 | /* | |
1044 | * We can optimise this out completely for !SMP, because the | |
1045 | * SMP rebalancing from interrupt is the only thing that cares | |
1046 | * here. | |
1047 | */ | |
3ca7a440 | 1048 | next->on_cpu = 1; |
4866cde0 NP |
1049 | #endif |
1050 | #ifdef __ARCH_WANT_INTERRUPTS_ON_CTXSW | |
05fa785c | 1051 | raw_spin_unlock_irq(&rq->lock); |
4866cde0 | 1052 | #else |
05fa785c | 1053 | raw_spin_unlock(&rq->lock); |
4866cde0 NP |
1054 | #endif |
1055 | } | |
1056 | ||
70b97a7f | 1057 | static inline void finish_lock_switch(struct rq *rq, struct task_struct *prev) |
4866cde0 NP |
1058 | { |
1059 | #ifdef CONFIG_SMP | |
1060 | /* | |
3ca7a440 | 1061 | * After ->on_cpu is cleared, the task can be moved to a different CPU. |
4866cde0 NP |
1062 | * We must ensure this doesn't happen until the switch is completely |
1063 | * finished. | |
1064 | */ | |
1065 | smp_wmb(); | |
3ca7a440 | 1066 | prev->on_cpu = 0; |
4866cde0 NP |
1067 | #endif |
1068 | #ifndef __ARCH_WANT_INTERRUPTS_ON_CTXSW | |
1069 | local_irq_enable(); | |
1da177e4 | 1070 | #endif |
4866cde0 NP |
1071 | } |
1072 | #endif /* __ARCH_WANT_UNLOCKED_CTXSW */ | |
1da177e4 | 1073 | |
0970d299 | 1074 | /* |
0122ec5b | 1075 | * __task_rq_lock - lock the rq @p resides on. |
b29739f9 | 1076 | */ |
70b97a7f | 1077 | static inline struct rq *__task_rq_lock(struct task_struct *p) |
b29739f9 IM |
1078 | __acquires(rq->lock) |
1079 | { | |
0970d299 PZ |
1080 | struct rq *rq; |
1081 | ||
0122ec5b PZ |
1082 | lockdep_assert_held(&p->pi_lock); |
1083 | ||
3a5c359a | 1084 | for (;;) { |
0970d299 | 1085 | rq = task_rq(p); |
05fa785c | 1086 | raw_spin_lock(&rq->lock); |
65cc8e48 | 1087 | if (likely(rq == task_rq(p))) |
3a5c359a | 1088 | return rq; |
05fa785c | 1089 | raw_spin_unlock(&rq->lock); |
b29739f9 | 1090 | } |
b29739f9 IM |
1091 | } |
1092 | ||
1da177e4 | 1093 | /* |
0122ec5b | 1094 | * task_rq_lock - lock p->pi_lock and lock the rq @p resides on. |
1da177e4 | 1095 | */ |
70b97a7f | 1096 | static struct rq *task_rq_lock(struct task_struct *p, unsigned long *flags) |
0122ec5b | 1097 | __acquires(p->pi_lock) |
1da177e4 LT |
1098 | __acquires(rq->lock) |
1099 | { | |
70b97a7f | 1100 | struct rq *rq; |
1da177e4 | 1101 | |
3a5c359a | 1102 | for (;;) { |
0122ec5b | 1103 | raw_spin_lock_irqsave(&p->pi_lock, *flags); |
3a5c359a | 1104 | rq = task_rq(p); |
05fa785c | 1105 | raw_spin_lock(&rq->lock); |
65cc8e48 | 1106 | if (likely(rq == task_rq(p))) |
3a5c359a | 1107 | return rq; |
0122ec5b PZ |
1108 | raw_spin_unlock(&rq->lock); |
1109 | raw_spin_unlock_irqrestore(&p->pi_lock, *flags); | |
1da177e4 | 1110 | } |
1da177e4 LT |
1111 | } |
1112 | ||
a9957449 | 1113 | static void __task_rq_unlock(struct rq *rq) |
b29739f9 IM |
1114 | __releases(rq->lock) |
1115 | { | |
05fa785c | 1116 | raw_spin_unlock(&rq->lock); |
b29739f9 IM |
1117 | } |
1118 | ||
0122ec5b PZ |
1119 | static inline void |
1120 | task_rq_unlock(struct rq *rq, struct task_struct *p, unsigned long *flags) | |
1da177e4 | 1121 | __releases(rq->lock) |
0122ec5b | 1122 | __releases(p->pi_lock) |
1da177e4 | 1123 | { |
0122ec5b PZ |
1124 | raw_spin_unlock(&rq->lock); |
1125 | raw_spin_unlock_irqrestore(&p->pi_lock, *flags); | |
1da177e4 LT |
1126 | } |
1127 | ||
1da177e4 | 1128 | /* |
cc2a73b5 | 1129 | * this_rq_lock - lock this runqueue and disable interrupts. |
1da177e4 | 1130 | */ |
a9957449 | 1131 | static struct rq *this_rq_lock(void) |
1da177e4 LT |
1132 | __acquires(rq->lock) |
1133 | { | |
70b97a7f | 1134 | struct rq *rq; |
1da177e4 LT |
1135 | |
1136 | local_irq_disable(); | |
1137 | rq = this_rq(); | |
05fa785c | 1138 | raw_spin_lock(&rq->lock); |
1da177e4 LT |
1139 | |
1140 | return rq; | |
1141 | } | |
1142 | ||
8f4d37ec PZ |
1143 | #ifdef CONFIG_SCHED_HRTICK |
1144 | /* | |
1145 | * Use HR-timers to deliver accurate preemption points. | |
1146 | * | |
1147 | * Its all a bit involved since we cannot program an hrt while holding the | |
1148 | * rq->lock. So what we do is store a state in in rq->hrtick_* and ask for a | |
1149 | * reschedule event. | |
1150 | * | |
1151 | * When we get rescheduled we reprogram the hrtick_timer outside of the | |
1152 | * rq->lock. | |
1153 | */ | |
8f4d37ec PZ |
1154 | |
1155 | /* | |
1156 | * Use hrtick when: | |
1157 | * - enabled by features | |
1158 | * - hrtimer is actually high res | |
1159 | */ | |
1160 | static inline int hrtick_enabled(struct rq *rq) | |
1161 | { | |
1162 | if (!sched_feat(HRTICK)) | |
1163 | return 0; | |
ba42059f | 1164 | if (!cpu_active(cpu_of(rq))) |
b328ca18 | 1165 | return 0; |
8f4d37ec PZ |
1166 | return hrtimer_is_hres_active(&rq->hrtick_timer); |
1167 | } | |
1168 | ||
8f4d37ec PZ |
1169 | static void hrtick_clear(struct rq *rq) |
1170 | { | |
1171 | if (hrtimer_active(&rq->hrtick_timer)) | |
1172 | hrtimer_cancel(&rq->hrtick_timer); | |
1173 | } | |
1174 | ||
8f4d37ec PZ |
1175 | /* |
1176 | * High-resolution timer tick. | |
1177 | * Runs from hardirq context with interrupts disabled. | |
1178 | */ | |
1179 | static enum hrtimer_restart hrtick(struct hrtimer *timer) | |
1180 | { | |
1181 | struct rq *rq = container_of(timer, struct rq, hrtick_timer); | |
1182 | ||
1183 | WARN_ON_ONCE(cpu_of(rq) != smp_processor_id()); | |
1184 | ||
05fa785c | 1185 | raw_spin_lock(&rq->lock); |
3e51f33f | 1186 | update_rq_clock(rq); |
8f4d37ec | 1187 | rq->curr->sched_class->task_tick(rq, rq->curr, 1); |
05fa785c | 1188 | raw_spin_unlock(&rq->lock); |
8f4d37ec PZ |
1189 | |
1190 | return HRTIMER_NORESTART; | |
1191 | } | |
1192 | ||
95e904c7 | 1193 | #ifdef CONFIG_SMP |
31656519 PZ |
1194 | /* |
1195 | * called from hardirq (IPI) context | |
1196 | */ | |
1197 | static void __hrtick_start(void *arg) | |
b328ca18 | 1198 | { |
31656519 | 1199 | struct rq *rq = arg; |
b328ca18 | 1200 | |
05fa785c | 1201 | raw_spin_lock(&rq->lock); |
31656519 PZ |
1202 | hrtimer_restart(&rq->hrtick_timer); |
1203 | rq->hrtick_csd_pending = 0; | |
05fa785c | 1204 | raw_spin_unlock(&rq->lock); |
b328ca18 PZ |
1205 | } |
1206 | ||
31656519 PZ |
1207 | /* |
1208 | * Called to set the hrtick timer state. | |
1209 | * | |
1210 | * called with rq->lock held and irqs disabled | |
1211 | */ | |
1212 | static void hrtick_start(struct rq *rq, u64 delay) | |
b328ca18 | 1213 | { |
31656519 PZ |
1214 | struct hrtimer *timer = &rq->hrtick_timer; |
1215 | ktime_t time = ktime_add_ns(timer->base->get_time(), delay); | |
b328ca18 | 1216 | |
cc584b21 | 1217 | hrtimer_set_expires(timer, time); |
31656519 PZ |
1218 | |
1219 | if (rq == this_rq()) { | |
1220 | hrtimer_restart(timer); | |
1221 | } else if (!rq->hrtick_csd_pending) { | |
6e275637 | 1222 | __smp_call_function_single(cpu_of(rq), &rq->hrtick_csd, 0); |
31656519 PZ |
1223 | rq->hrtick_csd_pending = 1; |
1224 | } | |
b328ca18 PZ |
1225 | } |
1226 | ||
1227 | static int | |
1228 | hotplug_hrtick(struct notifier_block *nfb, unsigned long action, void *hcpu) | |
1229 | { | |
1230 | int cpu = (int)(long)hcpu; | |
1231 | ||
1232 | switch (action) { | |
1233 | case CPU_UP_CANCELED: | |
1234 | case CPU_UP_CANCELED_FROZEN: | |
1235 | case CPU_DOWN_PREPARE: | |
1236 | case CPU_DOWN_PREPARE_FROZEN: | |
1237 | case CPU_DEAD: | |
1238 | case CPU_DEAD_FROZEN: | |
31656519 | 1239 | hrtick_clear(cpu_rq(cpu)); |
b328ca18 PZ |
1240 | return NOTIFY_OK; |
1241 | } | |
1242 | ||
1243 | return NOTIFY_DONE; | |
1244 | } | |
1245 | ||
fa748203 | 1246 | static __init void init_hrtick(void) |
b328ca18 PZ |
1247 | { |
1248 | hotcpu_notifier(hotplug_hrtick, 0); | |
1249 | } | |
31656519 PZ |
1250 | #else |
1251 | /* | |
1252 | * Called to set the hrtick timer state. | |
1253 | * | |
1254 | * called with rq->lock held and irqs disabled | |
1255 | */ | |
1256 | static void hrtick_start(struct rq *rq, u64 delay) | |
1257 | { | |
7f1e2ca9 | 1258 | __hrtimer_start_range_ns(&rq->hrtick_timer, ns_to_ktime(delay), 0, |
5c333864 | 1259 | HRTIMER_MODE_REL_PINNED, 0); |
31656519 | 1260 | } |
b328ca18 | 1261 | |
006c75f1 | 1262 | static inline void init_hrtick(void) |
8f4d37ec | 1263 | { |
8f4d37ec | 1264 | } |
31656519 | 1265 | #endif /* CONFIG_SMP */ |
8f4d37ec | 1266 | |
31656519 | 1267 | static void init_rq_hrtick(struct rq *rq) |
8f4d37ec | 1268 | { |
31656519 PZ |
1269 | #ifdef CONFIG_SMP |
1270 | rq->hrtick_csd_pending = 0; | |
8f4d37ec | 1271 | |
31656519 PZ |
1272 | rq->hrtick_csd.flags = 0; |
1273 | rq->hrtick_csd.func = __hrtick_start; | |
1274 | rq->hrtick_csd.info = rq; | |
1275 | #endif | |
8f4d37ec | 1276 | |
31656519 PZ |
1277 | hrtimer_init(&rq->hrtick_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); |
1278 | rq->hrtick_timer.function = hrtick; | |
8f4d37ec | 1279 | } |
006c75f1 | 1280 | #else /* CONFIG_SCHED_HRTICK */ |
8f4d37ec PZ |
1281 | static inline void hrtick_clear(struct rq *rq) |
1282 | { | |
1283 | } | |
1284 | ||
8f4d37ec PZ |
1285 | static inline void init_rq_hrtick(struct rq *rq) |
1286 | { | |
1287 | } | |
1288 | ||
b328ca18 PZ |
1289 | static inline void init_hrtick(void) |
1290 | { | |
1291 | } | |
006c75f1 | 1292 | #endif /* CONFIG_SCHED_HRTICK */ |
8f4d37ec | 1293 | |
c24d20db IM |
1294 | /* |
1295 | * resched_task - mark a task 'to be rescheduled now'. | |
1296 | * | |
1297 | * On UP this means the setting of the need_resched flag, on SMP it | |
1298 | * might also involve a cross-CPU call to trigger the scheduler on | |
1299 | * the target CPU. | |
1300 | */ | |
1301 | #ifdef CONFIG_SMP | |
1302 | ||
1303 | #ifndef tsk_is_polling | |
1304 | #define tsk_is_polling(t) test_tsk_thread_flag(t, TIF_POLLING_NRFLAG) | |
1305 | #endif | |
1306 | ||
31656519 | 1307 | static void resched_task(struct task_struct *p) |
c24d20db IM |
1308 | { |
1309 | int cpu; | |
1310 | ||
05fa785c | 1311 | assert_raw_spin_locked(&task_rq(p)->lock); |
c24d20db | 1312 | |
5ed0cec0 | 1313 | if (test_tsk_need_resched(p)) |
c24d20db IM |
1314 | return; |
1315 | ||
5ed0cec0 | 1316 | set_tsk_need_resched(p); |
c24d20db IM |
1317 | |
1318 | cpu = task_cpu(p); | |
1319 | if (cpu == smp_processor_id()) | |
1320 | return; | |
1321 | ||
1322 | /* NEED_RESCHED must be visible before we test polling */ | |
1323 | smp_mb(); | |
1324 | if (!tsk_is_polling(p)) | |
1325 | smp_send_reschedule(cpu); | |
1326 | } | |
1327 | ||
1328 | static void resched_cpu(int cpu) | |
1329 | { | |
1330 | struct rq *rq = cpu_rq(cpu); | |
1331 | unsigned long flags; | |
1332 | ||
05fa785c | 1333 | if (!raw_spin_trylock_irqsave(&rq->lock, flags)) |
c24d20db IM |
1334 | return; |
1335 | resched_task(cpu_curr(cpu)); | |
05fa785c | 1336 | raw_spin_unlock_irqrestore(&rq->lock, flags); |
c24d20db | 1337 | } |
06d8308c TG |
1338 | |
1339 | #ifdef CONFIG_NO_HZ | |
83cd4fe2 VP |
1340 | /* |
1341 | * In the semi idle case, use the nearest busy cpu for migrating timers | |
1342 | * from an idle cpu. This is good for power-savings. | |
1343 | * | |
1344 | * We don't do similar optimization for completely idle system, as | |
1345 | * selecting an idle cpu will add more delays to the timers than intended | |
1346 | * (as that cpu's timer base may not be uptodate wrt jiffies etc). | |
1347 | */ | |
1348 | int get_nohz_timer_target(void) | |
1349 | { | |
1350 | int cpu = smp_processor_id(); | |
1351 | int i; | |
1352 | struct sched_domain *sd; | |
1353 | ||
057f3fad | 1354 | rcu_read_lock(); |
83cd4fe2 | 1355 | for_each_domain(cpu, sd) { |
057f3fad PZ |
1356 | for_each_cpu(i, sched_domain_span(sd)) { |
1357 | if (!idle_cpu(i)) { | |
1358 | cpu = i; | |
1359 | goto unlock; | |
1360 | } | |
1361 | } | |
83cd4fe2 | 1362 | } |
057f3fad PZ |
1363 | unlock: |
1364 | rcu_read_unlock(); | |
83cd4fe2 VP |
1365 | return cpu; |
1366 | } | |
06d8308c TG |
1367 | /* |
1368 | * When add_timer_on() enqueues a timer into the timer wheel of an | |
1369 | * idle CPU then this timer might expire before the next timer event | |
1370 | * which is scheduled to wake up that CPU. In case of a completely | |
1371 | * idle system the next event might even be infinite time into the | |
1372 | * future. wake_up_idle_cpu() ensures that the CPU is woken up and | |
1373 | * leaves the inner idle loop so the newly added timer is taken into | |
1374 | * account when the CPU goes back to idle and evaluates the timer | |
1375 | * wheel for the next timer event. | |
1376 | */ | |
1377 | void wake_up_idle_cpu(int cpu) | |
1378 | { | |
1379 | struct rq *rq = cpu_rq(cpu); | |
1380 | ||
1381 | if (cpu == smp_processor_id()) | |
1382 | return; | |
1383 | ||
1384 | /* | |
1385 | * This is safe, as this function is called with the timer | |
1386 | * wheel base lock of (cpu) held. When the CPU is on the way | |
1387 | * to idle and has not yet set rq->curr to idle then it will | |
1388 | * be serialized on the timer wheel base lock and take the new | |
1389 | * timer into account automatically. | |
1390 | */ | |
1391 | if (rq->curr != rq->idle) | |
1392 | return; | |
1393 | ||
1394 | /* | |
1395 | * We can set TIF_RESCHED on the idle task of the other CPU | |
1396 | * lockless. The worst case is that the other CPU runs the | |
1397 | * idle task through an additional NOOP schedule() | |
1398 | */ | |
5ed0cec0 | 1399 | set_tsk_need_resched(rq->idle); |
06d8308c TG |
1400 | |
1401 | /* NEED_RESCHED must be visible before we test polling */ | |
1402 | smp_mb(); | |
1403 | if (!tsk_is_polling(rq->idle)) | |
1404 | smp_send_reschedule(cpu); | |
1405 | } | |
39c0cbe2 | 1406 | |
ca38062e SS |
1407 | static inline bool got_nohz_idle_kick(void) |
1408 | { | |
1409 | return idle_cpu(smp_processor_id()) && this_rq()->nohz_balance_kick; | |
1410 | } | |
1411 | ||
1412 | #else /* CONFIG_NO_HZ */ | |
1413 | ||
1414 | static inline bool got_nohz_idle_kick(void) | |
1415 | { | |
1416 | return false; | |
1417 | } | |
1418 | ||
6d6bc0ad | 1419 | #endif /* CONFIG_NO_HZ */ |
06d8308c | 1420 | |
e9e9250b PZ |
1421 | static u64 sched_avg_period(void) |
1422 | { | |
1423 | return (u64)sysctl_sched_time_avg * NSEC_PER_MSEC / 2; | |
1424 | } | |
1425 | ||
1426 | static void sched_avg_update(struct rq *rq) | |
1427 | { | |
1428 | s64 period = sched_avg_period(); | |
1429 | ||
1430 | while ((s64)(rq->clock - rq->age_stamp) > period) { | |
0d98bb26 WD |
1431 | /* |
1432 | * Inline assembly required to prevent the compiler | |
1433 | * optimising this loop into a divmod call. | |
1434 | * See __iter_div_u64_rem() for another example of this. | |
1435 | */ | |
1436 | asm("" : "+rm" (rq->age_stamp)); | |
e9e9250b PZ |
1437 | rq->age_stamp += period; |
1438 | rq->rt_avg /= 2; | |
1439 | } | |
1440 | } | |
1441 | ||
1442 | static void sched_rt_avg_update(struct rq *rq, u64 rt_delta) | |
1443 | { | |
1444 | rq->rt_avg += rt_delta; | |
1445 | sched_avg_update(rq); | |
1446 | } | |
1447 | ||
6d6bc0ad | 1448 | #else /* !CONFIG_SMP */ |
31656519 | 1449 | static void resched_task(struct task_struct *p) |
c24d20db | 1450 | { |
05fa785c | 1451 | assert_raw_spin_locked(&task_rq(p)->lock); |
31656519 | 1452 | set_tsk_need_resched(p); |
c24d20db | 1453 | } |
e9e9250b PZ |
1454 | |
1455 | static void sched_rt_avg_update(struct rq *rq, u64 rt_delta) | |
1456 | { | |
1457 | } | |
da2b71ed SS |
1458 | |
1459 | static void sched_avg_update(struct rq *rq) | |
1460 | { | |
1461 | } | |
6d6bc0ad | 1462 | #endif /* CONFIG_SMP */ |
c24d20db | 1463 | |
45bf76df IM |
1464 | #if BITS_PER_LONG == 32 |
1465 | # define WMULT_CONST (~0UL) | |
1466 | #else | |
1467 | # define WMULT_CONST (1UL << 32) | |
1468 | #endif | |
1469 | ||
1470 | #define WMULT_SHIFT 32 | |
1471 | ||
194081eb IM |
1472 | /* |
1473 | * Shift right and round: | |
1474 | */ | |
cf2ab469 | 1475 | #define SRR(x, y) (((x) + (1UL << ((y) - 1))) >> (y)) |
194081eb | 1476 | |
a7be37ac PZ |
1477 | /* |
1478 | * delta *= weight / lw | |
1479 | */ | |
cb1c4fc9 | 1480 | static unsigned long |
45bf76df IM |
1481 | calc_delta_mine(unsigned long delta_exec, unsigned long weight, |
1482 | struct load_weight *lw) | |
1483 | { | |
1484 | u64 tmp; | |
1485 | ||
c8b28116 NR |
1486 | /* |
1487 | * weight can be less than 2^SCHED_LOAD_RESOLUTION for task group sched | |
1488 | * entities since MIN_SHARES = 2. Treat weight as 1 if less than | |
1489 | * 2^SCHED_LOAD_RESOLUTION. | |
1490 | */ | |
1491 | if (likely(weight > (1UL << SCHED_LOAD_RESOLUTION))) | |
1492 | tmp = (u64)delta_exec * scale_load_down(weight); | |
1493 | else | |
1494 | tmp = (u64)delta_exec; | |
db670dac | 1495 | |
7a232e03 | 1496 | if (!lw->inv_weight) { |
c8b28116 NR |
1497 | unsigned long w = scale_load_down(lw->weight); |
1498 | ||
1499 | if (BITS_PER_LONG > 32 && unlikely(w >= WMULT_CONST)) | |
7a232e03 | 1500 | lw->inv_weight = 1; |
c8b28116 NR |
1501 | else if (unlikely(!w)) |
1502 | lw->inv_weight = WMULT_CONST; | |
7a232e03 | 1503 | else |
c8b28116 | 1504 | lw->inv_weight = WMULT_CONST / w; |
7a232e03 | 1505 | } |
45bf76df | 1506 | |
45bf76df IM |
1507 | /* |
1508 | * Check whether we'd overflow the 64-bit multiplication: | |
1509 | */ | |
194081eb | 1510 | if (unlikely(tmp > WMULT_CONST)) |
cf2ab469 | 1511 | tmp = SRR(SRR(tmp, WMULT_SHIFT/2) * lw->inv_weight, |
194081eb IM |
1512 | WMULT_SHIFT/2); |
1513 | else | |
cf2ab469 | 1514 | tmp = SRR(tmp * lw->inv_weight, WMULT_SHIFT); |
45bf76df | 1515 | |
ecf691da | 1516 | return (unsigned long)min(tmp, (u64)(unsigned long)LONG_MAX); |
45bf76df IM |
1517 | } |
1518 | ||
1091985b | 1519 | static inline void update_load_add(struct load_weight *lw, unsigned long inc) |
45bf76df IM |
1520 | { |
1521 | lw->weight += inc; | |
e89996ae | 1522 | lw->inv_weight = 0; |
45bf76df IM |
1523 | } |
1524 | ||
1091985b | 1525 | static inline void update_load_sub(struct load_weight *lw, unsigned long dec) |
45bf76df IM |
1526 | { |
1527 | lw->weight -= dec; | |
e89996ae | 1528 | lw->inv_weight = 0; |
45bf76df IM |
1529 | } |
1530 | ||
2069dd75 PZ |
1531 | static inline void update_load_set(struct load_weight *lw, unsigned long w) |
1532 | { | |
1533 | lw->weight = w; | |
1534 | lw->inv_weight = 0; | |
1535 | } | |
1536 | ||
2dd73a4f PW |
1537 | /* |
1538 | * To aid in avoiding the subversion of "niceness" due to uneven distribution | |
1539 | * of tasks with abnormal "nice" values across CPUs the contribution that | |
1540 | * each task makes to its run queue's load is weighted according to its | |
41a2d6cf | 1541 | * scheduling class and "nice" value. For SCHED_NORMAL tasks this is just a |
2dd73a4f PW |
1542 | * scaled version of the new time slice allocation that they receive on time |
1543 | * slice expiry etc. | |
1544 | */ | |
1545 | ||
cce7ade8 PZ |
1546 | #define WEIGHT_IDLEPRIO 3 |
1547 | #define WMULT_IDLEPRIO 1431655765 | |
dd41f596 IM |
1548 | |
1549 | /* | |
1550 | * Nice levels are multiplicative, with a gentle 10% change for every | |
1551 | * nice level changed. I.e. when a CPU-bound task goes from nice 0 to | |
1552 | * nice 1, it will get ~10% less CPU time than another CPU-bound task | |
1553 | * that remained on nice 0. | |
1554 | * | |
1555 | * The "10% effect" is relative and cumulative: from _any_ nice level, | |
1556 | * if you go up 1 level, it's -10% CPU usage, if you go down 1 level | |
f9153ee6 IM |
1557 | * it's +10% CPU usage. (to achieve that we use a multiplier of 1.25. |
1558 | * If a task goes up by ~10% and another task goes down by ~10% then | |
1559 | * the relative distance between them is ~25%.) | |
dd41f596 IM |
1560 | */ |
1561 | static const int prio_to_weight[40] = { | |
254753dc IM |
1562 | /* -20 */ 88761, 71755, 56483, 46273, 36291, |
1563 | /* -15 */ 29154, 23254, 18705, 14949, 11916, | |
1564 | /* -10 */ 9548, 7620, 6100, 4904, 3906, | |
1565 | /* -5 */ 3121, 2501, 1991, 1586, 1277, | |
1566 | /* 0 */ 1024, 820, 655, 526, 423, | |
1567 | /* 5 */ 335, 272, 215, 172, 137, | |
1568 | /* 10 */ 110, 87, 70, 56, 45, | |
1569 | /* 15 */ 36, 29, 23, 18, 15, | |
dd41f596 IM |
1570 | }; |
1571 | ||
5714d2de IM |
1572 | /* |
1573 | * Inverse (2^32/x) values of the prio_to_weight[] array, precalculated. | |
1574 | * | |
1575 | * In cases where the weight does not change often, we can use the | |
1576 | * precalculated inverse to speed up arithmetics by turning divisions | |
1577 | * into multiplications: | |
1578 | */ | |
dd41f596 | 1579 | static const u32 prio_to_wmult[40] = { |
254753dc IM |
1580 | /* -20 */ 48388, 59856, 76040, 92818, 118348, |
1581 | /* -15 */ 147320, 184698, 229616, 287308, 360437, | |
1582 | /* -10 */ 449829, 563644, 704093, 875809, 1099582, | |
1583 | /* -5 */ 1376151, 1717300, 2157191, 2708050, 3363326, | |
1584 | /* 0 */ 4194304, 5237765, 6557202, 8165337, 10153587, | |
1585 | /* 5 */ 12820798, 15790321, 19976592, 24970740, 31350126, | |
1586 | /* 10 */ 39045157, 49367440, 61356676, 76695844, 95443717, | |
1587 | /* 15 */ 119304647, 148102320, 186737708, 238609294, 286331153, | |
dd41f596 | 1588 | }; |
2dd73a4f | 1589 | |
ef12fefa BR |
1590 | /* Time spent by the tasks of the cpu accounting group executing in ... */ |
1591 | enum cpuacct_stat_index { | |
1592 | CPUACCT_STAT_USER, /* ... user mode */ | |
1593 | CPUACCT_STAT_SYSTEM, /* ... kernel mode */ | |
1594 | ||
1595 | CPUACCT_STAT_NSTATS, | |
1596 | }; | |
1597 | ||
d842de87 SV |
1598 | #ifdef CONFIG_CGROUP_CPUACCT |
1599 | static void cpuacct_charge(struct task_struct *tsk, u64 cputime); | |
ef12fefa BR |
1600 | static void cpuacct_update_stats(struct task_struct *tsk, |
1601 | enum cpuacct_stat_index idx, cputime_t val); | |
d842de87 SV |
1602 | #else |
1603 | static inline void cpuacct_charge(struct task_struct *tsk, u64 cputime) {} | |
ef12fefa BR |
1604 | static inline void cpuacct_update_stats(struct task_struct *tsk, |
1605 | enum cpuacct_stat_index idx, cputime_t val) {} | |
d842de87 SV |
1606 | #endif |
1607 | ||
18d95a28 PZ |
1608 | static inline void inc_cpu_load(struct rq *rq, unsigned long load) |
1609 | { | |
1610 | update_load_add(&rq->load, load); | |
1611 | } | |
1612 | ||
1613 | static inline void dec_cpu_load(struct rq *rq, unsigned long load) | |
1614 | { | |
1615 | update_load_sub(&rq->load, load); | |
1616 | } | |
1617 | ||
a790de99 PT |
1618 | #if defined(CONFIG_RT_GROUP_SCHED) || (defined(CONFIG_FAIR_GROUP_SCHED) && \ |
1619 | (defined(CONFIG_SMP) || defined(CONFIG_CFS_BANDWIDTH))) | |
eb755805 | 1620 | typedef int (*tg_visitor)(struct task_group *, void *); |
c09595f6 PZ |
1621 | |
1622 | /* | |
8277434e PT |
1623 | * Iterate task_group tree rooted at *from, calling @down when first entering a |
1624 | * node and @up when leaving it for the final time. | |
1625 | * | |
1626 | * Caller must hold rcu_lock or sufficient equivalent. | |
c09595f6 | 1627 | */ |
8277434e PT |
1628 | static int walk_tg_tree_from(struct task_group *from, |
1629 | tg_visitor down, tg_visitor up, void *data) | |
c09595f6 PZ |
1630 | { |
1631 | struct task_group *parent, *child; | |
eb755805 | 1632 | int ret; |
c09595f6 | 1633 | |
8277434e PT |
1634 | parent = from; |
1635 | ||
c09595f6 | 1636 | down: |
eb755805 PZ |
1637 | ret = (*down)(parent, data); |
1638 | if (ret) | |
8277434e | 1639 | goto out; |
c09595f6 PZ |
1640 | list_for_each_entry_rcu(child, &parent->children, siblings) { |
1641 | parent = child; | |
1642 | goto down; | |
1643 | ||
1644 | up: | |
1645 | continue; | |
1646 | } | |
eb755805 | 1647 | ret = (*up)(parent, data); |
8277434e PT |
1648 | if (ret || parent == from) |
1649 | goto out; | |
c09595f6 PZ |
1650 | |
1651 | child = parent; | |
1652 | parent = parent->parent; | |
1653 | if (parent) | |
1654 | goto up; | |
8277434e | 1655 | out: |
eb755805 | 1656 | return ret; |
c09595f6 PZ |
1657 | } |
1658 | ||
8277434e PT |
1659 | /* |
1660 | * Iterate the full tree, calling @down when first entering a node and @up when | |
1661 | * leaving it for the final time. | |
1662 | * | |
1663 | * Caller must hold rcu_lock or sufficient equivalent. | |
1664 | */ | |
1665 | ||
1666 | static inline int walk_tg_tree(tg_visitor down, tg_visitor up, void *data) | |
1667 | { | |
1668 | return walk_tg_tree_from(&root_task_group, down, up, data); | |
1669 | } | |
1670 | ||
eb755805 PZ |
1671 | static int tg_nop(struct task_group *tg, void *data) |
1672 | { | |
1673 | return 0; | |
c09595f6 | 1674 | } |
eb755805 PZ |
1675 | #endif |
1676 | ||
1677 | #ifdef CONFIG_SMP | |
f5f08f39 PZ |
1678 | /* Used instead of source_load when we know the type == 0 */ |
1679 | static unsigned long weighted_cpuload(const int cpu) | |
1680 | { | |
1681 | return cpu_rq(cpu)->load.weight; | |
1682 | } | |
1683 | ||
1684 | /* | |
1685 | * Return a low guess at the load of a migration-source cpu weighted | |
1686 | * according to the scheduling class and "nice" value. | |
1687 | * | |
1688 | * We want to under-estimate the load of migration sources, to | |
1689 | * balance conservatively. | |
1690 | */ | |
1691 | static unsigned long source_load(int cpu, int type) | |
1692 | { | |
1693 | struct rq *rq = cpu_rq(cpu); | |
1694 | unsigned long total = weighted_cpuload(cpu); | |
1695 | ||
1696 | if (type == 0 || !sched_feat(LB_BIAS)) | |
1697 | return total; | |
1698 | ||
1699 | return min(rq->cpu_load[type-1], total); | |
1700 | } | |
1701 | ||
1702 | /* | |
1703 | * Return a high guess at the load of a migration-target cpu weighted | |
1704 | * according to the scheduling class and "nice" value. | |
1705 | */ | |
1706 | static unsigned long target_load(int cpu, int type) | |
1707 | { | |
1708 | struct rq *rq = cpu_rq(cpu); | |
1709 | unsigned long total = weighted_cpuload(cpu); | |
1710 | ||
1711 | if (type == 0 || !sched_feat(LB_BIAS)) | |
1712 | return total; | |
1713 | ||
1714 | return max(rq->cpu_load[type-1], total); | |
1715 | } | |
1716 | ||
ae154be1 PZ |
1717 | static unsigned long power_of(int cpu) |
1718 | { | |
e51fd5e2 | 1719 | return cpu_rq(cpu)->cpu_power; |
ae154be1 PZ |
1720 | } |
1721 | ||
eb755805 PZ |
1722 | static int task_hot(struct task_struct *p, u64 now, struct sched_domain *sd); |
1723 | ||
1724 | static unsigned long cpu_avg_load_per_task(int cpu) | |
1725 | { | |
1726 | struct rq *rq = cpu_rq(cpu); | |
af6d596f | 1727 | unsigned long nr_running = ACCESS_ONCE(rq->nr_running); |
eb755805 | 1728 | |
4cd42620 | 1729 | if (nr_running) |
e2b245f8 | 1730 | return rq->load.weight / nr_running; |
eb755805 | 1731 | |
e2b245f8 | 1732 | return 0; |
eb755805 PZ |
1733 | } |
1734 | ||
8f45e2b5 GH |
1735 | #ifdef CONFIG_PREEMPT |
1736 | ||
b78bb868 PZ |
1737 | static void double_rq_lock(struct rq *rq1, struct rq *rq2); |
1738 | ||
70574a99 | 1739 | /* |
8f45e2b5 GH |
1740 | * fair double_lock_balance: Safely acquires both rq->locks in a fair |
1741 | * way at the expense of forcing extra atomic operations in all | |
1742 | * invocations. This assures that the double_lock is acquired using the | |
1743 | * same underlying policy as the spinlock_t on this architecture, which | |
1744 | * reduces latency compared to the unfair variant below. However, it | |
1745 | * also adds more overhead and therefore may reduce throughput. | |
70574a99 | 1746 | */ |
8f45e2b5 GH |
1747 | static inline int _double_lock_balance(struct rq *this_rq, struct rq *busiest) |
1748 | __releases(this_rq->lock) | |
1749 | __acquires(busiest->lock) | |
1750 | __acquires(this_rq->lock) | |
1751 | { | |
05fa785c | 1752 | raw_spin_unlock(&this_rq->lock); |
8f45e2b5 GH |
1753 | double_rq_lock(this_rq, busiest); |
1754 | ||
1755 | return 1; | |
1756 | } | |
1757 | ||
1758 | #else | |
1759 | /* | |
1760 | * Unfair double_lock_balance: Optimizes throughput at the expense of | |
1761 | * latency by eliminating extra atomic operations when the locks are | |
1762 | * already in proper order on entry. This favors lower cpu-ids and will | |
1763 | * grant the double lock to lower cpus over higher ids under contention, | |
1764 | * regardless of entry order into the function. | |
1765 | */ | |
1766 | static int _double_lock_balance(struct rq *this_rq, struct rq *busiest) | |
70574a99 AD |
1767 | __releases(this_rq->lock) |
1768 | __acquires(busiest->lock) | |
1769 | __acquires(this_rq->lock) | |
1770 | { | |
1771 | int ret = 0; | |
1772 | ||
05fa785c | 1773 | if (unlikely(!raw_spin_trylock(&busiest->lock))) { |
70574a99 | 1774 | if (busiest < this_rq) { |
05fa785c TG |
1775 | raw_spin_unlock(&this_rq->lock); |
1776 | raw_spin_lock(&busiest->lock); | |
1777 | raw_spin_lock_nested(&this_rq->lock, | |
1778 | SINGLE_DEPTH_NESTING); | |
70574a99 AD |
1779 | ret = 1; |
1780 | } else | |
05fa785c TG |
1781 | raw_spin_lock_nested(&busiest->lock, |
1782 | SINGLE_DEPTH_NESTING); | |
70574a99 AD |
1783 | } |
1784 | return ret; | |
1785 | } | |
1786 | ||
8f45e2b5 GH |
1787 | #endif /* CONFIG_PREEMPT */ |
1788 | ||
1789 | /* | |
1790 | * double_lock_balance - lock the busiest runqueue, this_rq is locked already. | |
1791 | */ | |
1792 | static int double_lock_balance(struct rq *this_rq, struct rq *busiest) | |
1793 | { | |
1794 | if (unlikely(!irqs_disabled())) { | |
1795 | /* printk() doesn't work good under rq->lock */ | |
05fa785c | 1796 | raw_spin_unlock(&this_rq->lock); |
8f45e2b5 GH |
1797 | BUG_ON(1); |
1798 | } | |
1799 | ||
1800 | return _double_lock_balance(this_rq, busiest); | |
1801 | } | |
1802 | ||
70574a99 AD |
1803 | static inline void double_unlock_balance(struct rq *this_rq, struct rq *busiest) |
1804 | __releases(busiest->lock) | |
1805 | { | |
05fa785c | 1806 | raw_spin_unlock(&busiest->lock); |
70574a99 AD |
1807 | lock_set_subclass(&this_rq->lock.dep_map, 0, _RET_IP_); |
1808 | } | |
1e3c88bd PZ |
1809 | |
1810 | /* | |
1811 | * double_rq_lock - safely lock two runqueues | |
1812 | * | |
1813 | * Note this does not disable interrupts like task_rq_lock, | |
1814 | * you need to do so manually before calling. | |
1815 | */ | |
1816 | static void double_rq_lock(struct rq *rq1, struct rq *rq2) | |
1817 | __acquires(rq1->lock) | |
1818 | __acquires(rq2->lock) | |
1819 | { | |
1820 | BUG_ON(!irqs_disabled()); | |
1821 | if (rq1 == rq2) { | |
1822 | raw_spin_lock(&rq1->lock); | |
1823 | __acquire(rq2->lock); /* Fake it out ;) */ | |
1824 | } else { | |
1825 | if (rq1 < rq2) { | |
1826 | raw_spin_lock(&rq1->lock); | |
1827 | raw_spin_lock_nested(&rq2->lock, SINGLE_DEPTH_NESTING); | |
1828 | } else { | |
1829 | raw_spin_lock(&rq2->lock); | |
1830 | raw_spin_lock_nested(&rq1->lock, SINGLE_DEPTH_NESTING); | |
1831 | } | |
1832 | } | |
1e3c88bd PZ |
1833 | } |
1834 | ||
1835 | /* | |
1836 | * double_rq_unlock - safely unlock two runqueues | |
1837 | * | |
1838 | * Note this does not restore interrupts like task_rq_unlock, | |
1839 | * you need to do so manually after calling. | |
1840 | */ | |
1841 | static void double_rq_unlock(struct rq *rq1, struct rq *rq2) | |
1842 | __releases(rq1->lock) | |
1843 | __releases(rq2->lock) | |
1844 | { | |
1845 | raw_spin_unlock(&rq1->lock); | |
1846 | if (rq1 != rq2) | |
1847 | raw_spin_unlock(&rq2->lock); | |
1848 | else | |
1849 | __release(rq2->lock); | |
1850 | } | |
1851 | ||
d95f4122 MG |
1852 | #else /* CONFIG_SMP */ |
1853 | ||
1854 | /* | |
1855 | * double_rq_lock - safely lock two runqueues | |
1856 | * | |
1857 | * Note this does not disable interrupts like task_rq_lock, | |
1858 | * you need to do so manually before calling. | |
1859 | */ | |
1860 | static void double_rq_lock(struct rq *rq1, struct rq *rq2) | |
1861 | __acquires(rq1->lock) | |
1862 | __acquires(rq2->lock) | |
1863 | { | |
1864 | BUG_ON(!irqs_disabled()); | |
1865 | BUG_ON(rq1 != rq2); | |
1866 | raw_spin_lock(&rq1->lock); | |
1867 | __acquire(rq2->lock); /* Fake it out ;) */ | |
1868 | } | |
1869 | ||
1870 | /* | |
1871 | * double_rq_unlock - safely unlock two runqueues | |
1872 | * | |
1873 | * Note this does not restore interrupts like task_rq_unlock, | |
1874 | * you need to do so manually after calling. | |
1875 | */ | |
1876 | static void double_rq_unlock(struct rq *rq1, struct rq *rq2) | |
1877 | __releases(rq1->lock) | |
1878 | __releases(rq2->lock) | |
1879 | { | |
1880 | BUG_ON(rq1 != rq2); | |
1881 | raw_spin_unlock(&rq1->lock); | |
1882 | __release(rq2->lock); | |
1883 | } | |
1884 | ||
18d95a28 PZ |
1885 | #endif |
1886 | ||
74f5187a | 1887 | static void calc_load_account_idle(struct rq *this_rq); |
0bcdcf28 | 1888 | static void update_sysctl(void); |
acb4a848 | 1889 | static int get_update_sysctl_factor(void); |
fdf3e95d | 1890 | static void update_cpu_load(struct rq *this_rq); |
dce48a84 | 1891 | |
cd29fe6f PZ |
1892 | static inline void __set_task_cpu(struct task_struct *p, unsigned int cpu) |
1893 | { | |
1894 | set_task_rq(p, cpu); | |
1895 | #ifdef CONFIG_SMP | |
1896 | /* | |
1897 | * After ->cpu is set up to a new value, task_rq_lock(p, ...) can be | |
1898 | * successfuly executed on another CPU. We must ensure that updates of | |
1899 | * per-task data have been completed by this moment. | |
1900 | */ | |
1901 | smp_wmb(); | |
1902 | task_thread_info(p)->cpu = cpu; | |
1903 | #endif | |
1904 | } | |
dce48a84 | 1905 | |
1e3c88bd | 1906 | static const struct sched_class rt_sched_class; |
dd41f596 | 1907 | |
34f971f6 | 1908 | #define sched_class_highest (&stop_sched_class) |
1f11eb6a GH |
1909 | #define for_each_class(class) \ |
1910 | for (class = sched_class_highest; class; class = class->next) | |
dd41f596 | 1911 | |
1e3c88bd PZ |
1912 | #include "sched_stats.h" |
1913 | ||
c09595f6 | 1914 | static void inc_nr_running(struct rq *rq) |
9c217245 IM |
1915 | { |
1916 | rq->nr_running++; | |
9c217245 IM |
1917 | } |
1918 | ||
c09595f6 | 1919 | static void dec_nr_running(struct rq *rq) |
9c217245 IM |
1920 | { |
1921 | rq->nr_running--; | |
9c217245 IM |
1922 | } |
1923 | ||
45bf76df IM |
1924 | static void set_load_weight(struct task_struct *p) |
1925 | { | |
f05998d4 NR |
1926 | int prio = p->static_prio - MAX_RT_PRIO; |
1927 | struct load_weight *load = &p->se.load; | |
1928 | ||
dd41f596 IM |
1929 | /* |
1930 | * SCHED_IDLE tasks get minimal weight: | |
1931 | */ | |
1932 | if (p->policy == SCHED_IDLE) { | |
c8b28116 | 1933 | load->weight = scale_load(WEIGHT_IDLEPRIO); |
f05998d4 | 1934 | load->inv_weight = WMULT_IDLEPRIO; |
dd41f596 IM |
1935 | return; |
1936 | } | |
71f8bd46 | 1937 | |
c8b28116 | 1938 | load->weight = scale_load(prio_to_weight[prio]); |
f05998d4 | 1939 | load->inv_weight = prio_to_wmult[prio]; |
71f8bd46 IM |
1940 | } |
1941 | ||
371fd7e7 | 1942 | static void enqueue_task(struct rq *rq, struct task_struct *p, int flags) |
2087a1ad | 1943 | { |
a64692a3 | 1944 | update_rq_clock(rq); |
dd41f596 | 1945 | sched_info_queued(p); |
371fd7e7 | 1946 | p->sched_class->enqueue_task(rq, p, flags); |
71f8bd46 IM |
1947 | } |
1948 | ||
371fd7e7 | 1949 | static void dequeue_task(struct rq *rq, struct task_struct *p, int flags) |
71f8bd46 | 1950 | { |
a64692a3 | 1951 | update_rq_clock(rq); |
46ac22ba | 1952 | sched_info_dequeued(p); |
371fd7e7 | 1953 | p->sched_class->dequeue_task(rq, p, flags); |
71f8bd46 IM |
1954 | } |
1955 | ||
1e3c88bd PZ |
1956 | /* |
1957 | * activate_task - move a task to the runqueue. | |
1958 | */ | |
371fd7e7 | 1959 | static void activate_task(struct rq *rq, struct task_struct *p, int flags) |
1e3c88bd PZ |
1960 | { |
1961 | if (task_contributes_to_load(p)) | |
1962 | rq->nr_uninterruptible--; | |
1963 | ||
371fd7e7 | 1964 | enqueue_task(rq, p, flags); |
1e3c88bd PZ |
1965 | } |
1966 | ||
1967 | /* | |
1968 | * deactivate_task - remove a task from the runqueue. | |
1969 | */ | |
371fd7e7 | 1970 | static void deactivate_task(struct rq *rq, struct task_struct *p, int flags) |
1e3c88bd PZ |
1971 | { |
1972 | if (task_contributes_to_load(p)) | |
1973 | rq->nr_uninterruptible++; | |
1974 | ||
371fd7e7 | 1975 | dequeue_task(rq, p, flags); |
1e3c88bd PZ |
1976 | } |
1977 | ||
b52bfee4 VP |
1978 | #ifdef CONFIG_IRQ_TIME_ACCOUNTING |
1979 | ||
305e6835 VP |
1980 | /* |
1981 | * There are no locks covering percpu hardirq/softirq time. | |
1982 | * They are only modified in account_system_vtime, on corresponding CPU | |
1983 | * with interrupts disabled. So, writes are safe. | |
1984 | * They are read and saved off onto struct rq in update_rq_clock(). | |
1985 | * This may result in other CPU reading this CPU's irq time and can | |
1986 | * race with irq/account_system_vtime on this CPU. We would either get old | |
8e92c201 PZ |
1987 | * or new value with a side effect of accounting a slice of irq time to wrong |
1988 | * task when irq is in progress while we read rq->clock. That is a worthy | |
1989 | * compromise in place of having locks on each irq in account_system_time. | |
305e6835 | 1990 | */ |
b52bfee4 VP |
1991 | static DEFINE_PER_CPU(u64, cpu_hardirq_time); |
1992 | static DEFINE_PER_CPU(u64, cpu_softirq_time); | |
1993 | ||
1994 | static DEFINE_PER_CPU(u64, irq_start_time); | |
1995 | static int sched_clock_irqtime; | |
1996 | ||
1997 | void enable_sched_clock_irqtime(void) | |
1998 | { | |
1999 | sched_clock_irqtime = 1; | |
2000 | } | |
2001 | ||
2002 | void disable_sched_clock_irqtime(void) | |
2003 | { | |
2004 | sched_clock_irqtime = 0; | |
2005 | } | |
2006 | ||
8e92c201 PZ |
2007 | #ifndef CONFIG_64BIT |
2008 | static DEFINE_PER_CPU(seqcount_t, irq_time_seq); | |
2009 | ||
2010 | static inline void irq_time_write_begin(void) | |
2011 | { | |
2012 | __this_cpu_inc(irq_time_seq.sequence); | |
2013 | smp_wmb(); | |
2014 | } | |
2015 | ||
2016 | static inline void irq_time_write_end(void) | |
2017 | { | |
2018 | smp_wmb(); | |
2019 | __this_cpu_inc(irq_time_seq.sequence); | |
2020 | } | |
2021 | ||
2022 | static inline u64 irq_time_read(int cpu) | |
2023 | { | |
2024 | u64 irq_time; | |
2025 | unsigned seq; | |
2026 | ||
2027 | do { | |
2028 | seq = read_seqcount_begin(&per_cpu(irq_time_seq, cpu)); | |
2029 | irq_time = per_cpu(cpu_softirq_time, cpu) + | |
2030 | per_cpu(cpu_hardirq_time, cpu); | |
2031 | } while (read_seqcount_retry(&per_cpu(irq_time_seq, cpu), seq)); | |
2032 | ||
2033 | return irq_time; | |
2034 | } | |
2035 | #else /* CONFIG_64BIT */ | |
2036 | static inline void irq_time_write_begin(void) | |
2037 | { | |
2038 | } | |
2039 | ||
2040 | static inline void irq_time_write_end(void) | |
2041 | { | |
2042 | } | |
2043 | ||
2044 | static inline u64 irq_time_read(int cpu) | |
305e6835 | 2045 | { |
305e6835 VP |
2046 | return per_cpu(cpu_softirq_time, cpu) + per_cpu(cpu_hardirq_time, cpu); |
2047 | } | |
8e92c201 | 2048 | #endif /* CONFIG_64BIT */ |
305e6835 | 2049 | |
fe44d621 PZ |
2050 | /* |
2051 | * Called before incrementing preempt_count on {soft,}irq_enter | |
2052 | * and before decrementing preempt_count on {soft,}irq_exit. | |
2053 | */ | |
b52bfee4 VP |
2054 | void account_system_vtime(struct task_struct *curr) |
2055 | { | |
2056 | unsigned long flags; | |
fe44d621 | 2057 | s64 delta; |
b52bfee4 | 2058 | int cpu; |
b52bfee4 VP |
2059 | |
2060 | if (!sched_clock_irqtime) | |
2061 | return; | |
2062 | ||
2063 | local_irq_save(flags); | |
2064 | ||
b52bfee4 | 2065 | cpu = smp_processor_id(); |
fe44d621 PZ |
2066 | delta = sched_clock_cpu(cpu) - __this_cpu_read(irq_start_time); |
2067 | __this_cpu_add(irq_start_time, delta); | |
2068 | ||
8e92c201 | 2069 | irq_time_write_begin(); |
b52bfee4 VP |
2070 | /* |
2071 | * We do not account for softirq time from ksoftirqd here. | |
2072 | * We want to continue accounting softirq time to ksoftirqd thread | |
2073 | * in that case, so as not to confuse scheduler with a special task | |
2074 | * that do not consume any time, but still wants to run. | |
2075 | */ | |
2076 | if (hardirq_count()) | |
fe44d621 | 2077 | __this_cpu_add(cpu_hardirq_time, delta); |
4dd53d89 | 2078 | else if (in_serving_softirq() && curr != this_cpu_ksoftirqd()) |
fe44d621 | 2079 | __this_cpu_add(cpu_softirq_time, delta); |
b52bfee4 | 2080 | |
8e92c201 | 2081 | irq_time_write_end(); |
b52bfee4 VP |
2082 | local_irq_restore(flags); |
2083 | } | |
b7dadc38 | 2084 | EXPORT_SYMBOL_GPL(account_system_vtime); |
b52bfee4 | 2085 | |
e6e6685a GC |
2086 | #endif /* CONFIG_IRQ_TIME_ACCOUNTING */ |
2087 | ||
2088 | #ifdef CONFIG_PARAVIRT | |
2089 | static inline u64 steal_ticks(u64 steal) | |
aa483808 | 2090 | { |
e6e6685a GC |
2091 | if (unlikely(steal > NSEC_PER_SEC)) |
2092 | return div_u64(steal, TICK_NSEC); | |
fe44d621 | 2093 | |
e6e6685a GC |
2094 | return __iter_div_u64_rem(steal, TICK_NSEC, &steal); |
2095 | } | |
2096 | #endif | |
2097 | ||
fe44d621 | 2098 | static void update_rq_clock_task(struct rq *rq, s64 delta) |
aa483808 | 2099 | { |
095c0aa8 GC |
2100 | /* |
2101 | * In theory, the compile should just see 0 here, and optimize out the call | |
2102 | * to sched_rt_avg_update. But I don't trust it... | |
2103 | */ | |
2104 | #if defined(CONFIG_IRQ_TIME_ACCOUNTING) || defined(CONFIG_PARAVIRT_TIME_ACCOUNTING) | |
2105 | s64 steal = 0, irq_delta = 0; | |
2106 | #endif | |
2107 | #ifdef CONFIG_IRQ_TIME_ACCOUNTING | |
8e92c201 | 2108 | irq_delta = irq_time_read(cpu_of(rq)) - rq->prev_irq_time; |
fe44d621 PZ |
2109 | |
2110 | /* | |
2111 | * Since irq_time is only updated on {soft,}irq_exit, we might run into | |
2112 | * this case when a previous update_rq_clock() happened inside a | |
2113 | * {soft,}irq region. | |
2114 | * | |
2115 | * When this happens, we stop ->clock_task and only update the | |
2116 | * prev_irq_time stamp to account for the part that fit, so that a next | |
2117 | * update will consume the rest. This ensures ->clock_task is | |
2118 | * monotonic. | |
2119 | * | |
2120 | * It does however cause some slight miss-attribution of {soft,}irq | |
2121 | * time, a more accurate solution would be to update the irq_time using | |
2122 | * the current rq->clock timestamp, except that would require using | |
2123 | * atomic ops. | |
2124 | */ | |
2125 | if (irq_delta > delta) | |
2126 | irq_delta = delta; | |
2127 | ||
2128 | rq->prev_irq_time += irq_delta; | |
2129 | delta -= irq_delta; | |
095c0aa8 GC |
2130 | #endif |
2131 | #ifdef CONFIG_PARAVIRT_TIME_ACCOUNTING | |
2132 | if (static_branch((¶virt_steal_rq_enabled))) { | |
2133 | u64 st; | |
2134 | ||
2135 | steal = paravirt_steal_clock(cpu_of(rq)); | |
2136 | steal -= rq->prev_steal_time_rq; | |
2137 | ||
2138 | if (unlikely(steal > delta)) | |
2139 | steal = delta; | |
2140 | ||
2141 | st = steal_ticks(steal); | |
2142 | steal = st * TICK_NSEC; | |
2143 | ||
2144 | rq->prev_steal_time_rq += steal; | |
2145 | ||
2146 | delta -= steal; | |
2147 | } | |
2148 | #endif | |
2149 | ||
fe44d621 PZ |
2150 | rq->clock_task += delta; |
2151 | ||
095c0aa8 GC |
2152 | #if defined(CONFIG_IRQ_TIME_ACCOUNTING) || defined(CONFIG_PARAVIRT_TIME_ACCOUNTING) |
2153 | if ((irq_delta + steal) && sched_feat(NONTASK_POWER)) | |
2154 | sched_rt_avg_update(rq, irq_delta + steal); | |
2155 | #endif | |
aa483808 VP |
2156 | } |
2157 | ||
095c0aa8 | 2158 | #ifdef CONFIG_IRQ_TIME_ACCOUNTING |
abb74cef VP |
2159 | static int irqtime_account_hi_update(void) |
2160 | { | |
2161 | struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat; | |
2162 | unsigned long flags; | |
2163 | u64 latest_ns; | |
2164 | int ret = 0; | |
2165 | ||
2166 | local_irq_save(flags); | |
2167 | latest_ns = this_cpu_read(cpu_hardirq_time); | |
2168 | if (cputime64_gt(nsecs_to_cputime64(latest_ns), cpustat->irq)) | |
2169 | ret = 1; | |
2170 | local_irq_restore(flags); | |
2171 | return ret; | |
2172 | } | |
2173 | ||
2174 | static int irqtime_account_si_update(void) | |
2175 | { | |
2176 | struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat; | |
2177 | unsigned long flags; | |
2178 | u64 latest_ns; | |
2179 | int ret = 0; | |
2180 | ||
2181 | local_irq_save(flags); | |
2182 | latest_ns = this_cpu_read(cpu_softirq_time); | |
2183 | if (cputime64_gt(nsecs_to_cputime64(latest_ns), cpustat->softirq)) | |
2184 | ret = 1; | |
2185 | local_irq_restore(flags); | |
2186 | return ret; | |
2187 | } | |
2188 | ||
fe44d621 | 2189 | #else /* CONFIG_IRQ_TIME_ACCOUNTING */ |
305e6835 | 2190 | |
abb74cef VP |
2191 | #define sched_clock_irqtime (0) |
2192 | ||
095c0aa8 | 2193 | #endif |
b52bfee4 | 2194 | |
1e3c88bd PZ |
2195 | #include "sched_idletask.c" |
2196 | #include "sched_fair.c" | |
2197 | #include "sched_rt.c" | |
5091faa4 | 2198 | #include "sched_autogroup.c" |
34f971f6 | 2199 | #include "sched_stoptask.c" |
1e3c88bd PZ |
2200 | #ifdef CONFIG_SCHED_DEBUG |
2201 | # include "sched_debug.c" | |
2202 | #endif | |
2203 | ||
34f971f6 PZ |
2204 | void sched_set_stop_task(int cpu, struct task_struct *stop) |
2205 | { | |
2206 | struct sched_param param = { .sched_priority = MAX_RT_PRIO - 1 }; | |
2207 | struct task_struct *old_stop = cpu_rq(cpu)->stop; | |
2208 | ||
2209 | if (stop) { | |
2210 | /* | |
2211 | * Make it appear like a SCHED_FIFO task, its something | |
2212 | * userspace knows about and won't get confused about. | |
2213 | * | |
2214 | * Also, it will make PI more or less work without too | |
2215 | * much confusion -- but then, stop work should not | |
2216 | * rely on PI working anyway. | |
2217 | */ | |
2218 | sched_setscheduler_nocheck(stop, SCHED_FIFO, ¶m); | |
2219 | ||
2220 | stop->sched_class = &stop_sched_class; | |
2221 | } | |
2222 | ||
2223 | cpu_rq(cpu)->stop = stop; | |
2224 | ||
2225 | if (old_stop) { | |
2226 | /* | |
2227 | * Reset it back to a normal scheduling class so that | |
2228 | * it can die in pieces. | |
2229 | */ | |
2230 | old_stop->sched_class = &rt_sched_class; | |
2231 | } | |
2232 | } | |
2233 | ||
14531189 | 2234 | /* |
dd41f596 | 2235 | * __normal_prio - return the priority that is based on the static prio |
14531189 | 2236 | */ |
14531189 IM |
2237 | static inline int __normal_prio(struct task_struct *p) |
2238 | { | |
dd41f596 | 2239 | return p->static_prio; |
14531189 IM |
2240 | } |
2241 | ||
b29739f9 IM |
2242 | /* |
2243 | * Calculate the expected normal priority: i.e. priority | |
2244 | * without taking RT-inheritance into account. Might be | |
2245 | * boosted by interactivity modifiers. Changes upon fork, | |
2246 | * setprio syscalls, and whenever the interactivity | |
2247 | * estimator recalculates. | |
2248 | */ | |
36c8b586 | 2249 | static inline int normal_prio(struct task_struct *p) |
b29739f9 IM |
2250 | { |
2251 | int prio; | |
2252 | ||
e05606d3 | 2253 | if (task_has_rt_policy(p)) |
b29739f9 IM |
2254 | prio = MAX_RT_PRIO-1 - p->rt_priority; |
2255 | else | |
2256 | prio = __normal_prio(p); | |
2257 | return prio; | |
2258 | } | |
2259 | ||
2260 | /* | |
2261 | * Calculate the current priority, i.e. the priority | |
2262 | * taken into account by the scheduler. This value might | |
2263 | * be boosted by RT tasks, or might be boosted by | |
2264 | * interactivity modifiers. Will be RT if the task got | |
2265 | * RT-boosted. If not then it returns p->normal_prio. | |
2266 | */ | |
36c8b586 | 2267 | static int effective_prio(struct task_struct *p) |
b29739f9 IM |
2268 | { |
2269 | p->normal_prio = normal_prio(p); | |
2270 | /* | |
2271 | * If we are RT tasks or we were boosted to RT priority, | |
2272 | * keep the priority unchanged. Otherwise, update priority | |
2273 | * to the normal priority: | |
2274 | */ | |
2275 | if (!rt_prio(p->prio)) | |
2276 | return p->normal_prio; | |
2277 | return p->prio; | |
2278 | } | |
2279 | ||
1da177e4 LT |
2280 | /** |
2281 | * task_curr - is this task currently executing on a CPU? | |
2282 | * @p: the task in question. | |
2283 | */ | |
36c8b586 | 2284 | inline int task_curr(const struct task_struct *p) |
1da177e4 LT |
2285 | { |
2286 | return cpu_curr(task_cpu(p)) == p; | |
2287 | } | |
2288 | ||
cb469845 SR |
2289 | static inline void check_class_changed(struct rq *rq, struct task_struct *p, |
2290 | const struct sched_class *prev_class, | |
da7a735e | 2291 | int oldprio) |
cb469845 SR |
2292 | { |
2293 | if (prev_class != p->sched_class) { | |
2294 | if (prev_class->switched_from) | |
da7a735e PZ |
2295 | prev_class->switched_from(rq, p); |
2296 | p->sched_class->switched_to(rq, p); | |
2297 | } else if (oldprio != p->prio) | |
2298 | p->sched_class->prio_changed(rq, p, oldprio); | |
cb469845 SR |
2299 | } |
2300 | ||
1e5a7405 PZ |
2301 | static void check_preempt_curr(struct rq *rq, struct task_struct *p, int flags) |
2302 | { | |
2303 | const struct sched_class *class; | |
2304 | ||
2305 | if (p->sched_class == rq->curr->sched_class) { | |
2306 | rq->curr->sched_class->check_preempt_curr(rq, p, flags); | |
2307 | } else { | |
2308 | for_each_class(class) { | |
2309 | if (class == rq->curr->sched_class) | |
2310 | break; | |
2311 | if (class == p->sched_class) { | |
2312 | resched_task(rq->curr); | |
2313 | break; | |
2314 | } | |
2315 | } | |
2316 | } | |
2317 | ||
2318 | /* | |
2319 | * A queue event has occurred, and we're going to schedule. In | |
2320 | * this case, we can save a useless back to back clock update. | |
2321 | */ | |
fd2f4419 | 2322 | if (rq->curr->on_rq && test_tsk_need_resched(rq->curr)) |
1e5a7405 PZ |
2323 | rq->skip_clock_update = 1; |
2324 | } | |
2325 | ||
1da177e4 | 2326 | #ifdef CONFIG_SMP |
cc367732 IM |
2327 | /* |
2328 | * Is this task likely cache-hot: | |
2329 | */ | |
e7693a36 | 2330 | static int |
cc367732 IM |
2331 | task_hot(struct task_struct *p, u64 now, struct sched_domain *sd) |
2332 | { | |
2333 | s64 delta; | |
2334 | ||
e6c8fba7 PZ |
2335 | if (p->sched_class != &fair_sched_class) |
2336 | return 0; | |
2337 | ||
ef8002f6 NR |
2338 | if (unlikely(p->policy == SCHED_IDLE)) |
2339 | return 0; | |
2340 | ||
f540a608 IM |
2341 | /* |
2342 | * Buddy candidates are cache hot: | |
2343 | */ | |
f685ceac | 2344 | if (sched_feat(CACHE_HOT_BUDDY) && this_rq()->nr_running && |
4793241b PZ |
2345 | (&p->se == cfs_rq_of(&p->se)->next || |
2346 | &p->se == cfs_rq_of(&p->se)->last)) | |
f540a608 IM |
2347 | return 1; |
2348 | ||
6bc1665b IM |
2349 | if (sysctl_sched_migration_cost == -1) |
2350 | return 1; | |
2351 | if (sysctl_sched_migration_cost == 0) | |
2352 | return 0; | |
2353 | ||
cc367732 IM |
2354 | delta = now - p->se.exec_start; |
2355 | ||
2356 | return delta < (s64)sysctl_sched_migration_cost; | |
2357 | } | |
2358 | ||
dd41f596 | 2359 | void set_task_cpu(struct task_struct *p, unsigned int new_cpu) |
c65cc870 | 2360 | { |
e2912009 PZ |
2361 | #ifdef CONFIG_SCHED_DEBUG |
2362 | /* | |
2363 | * We should never call set_task_cpu() on a blocked task, | |
2364 | * ttwu() will sort out the placement. | |
2365 | */ | |
077614ee PZ |
2366 | WARN_ON_ONCE(p->state != TASK_RUNNING && p->state != TASK_WAKING && |
2367 | !(task_thread_info(p)->preempt_count & PREEMPT_ACTIVE)); | |
0122ec5b PZ |
2368 | |
2369 | #ifdef CONFIG_LOCKDEP | |
6c6c54e1 PZ |
2370 | /* |
2371 | * The caller should hold either p->pi_lock or rq->lock, when changing | |
2372 | * a task's CPU. ->pi_lock for waking tasks, rq->lock for runnable tasks. | |
2373 | * | |
2374 | * sched_move_task() holds both and thus holding either pins the cgroup, | |
2375 | * see set_task_rq(). | |
2376 | * | |
2377 | * Furthermore, all task_rq users should acquire both locks, see | |
2378 | * task_rq_lock(). | |
2379 | */ | |
0122ec5b PZ |
2380 | WARN_ON_ONCE(debug_locks && !(lockdep_is_held(&p->pi_lock) || |
2381 | lockdep_is_held(&task_rq(p)->lock))); | |
2382 | #endif | |
e2912009 PZ |
2383 | #endif |
2384 | ||
de1d7286 | 2385 | trace_sched_migrate_task(p, new_cpu); |
cbc34ed1 | 2386 | |
0c69774e PZ |
2387 | if (task_cpu(p) != new_cpu) { |
2388 | p->se.nr_migrations++; | |
a8b0ca17 | 2389 | perf_sw_event(PERF_COUNT_SW_CPU_MIGRATIONS, 1, NULL, 0); |
0c69774e | 2390 | } |
dd41f596 IM |
2391 | |
2392 | __set_task_cpu(p, new_cpu); | |
c65cc870 IM |
2393 | } |
2394 | ||
969c7921 | 2395 | struct migration_arg { |
36c8b586 | 2396 | struct task_struct *task; |
1da177e4 | 2397 | int dest_cpu; |
70b97a7f | 2398 | }; |
1da177e4 | 2399 | |
969c7921 TH |
2400 | static int migration_cpu_stop(void *data); |
2401 | ||
1da177e4 LT |
2402 | /* |
2403 | * wait_task_inactive - wait for a thread to unschedule. | |
2404 | * | |
85ba2d86 RM |
2405 | * If @match_state is nonzero, it's the @p->state value just checked and |
2406 | * not expected to change. If it changes, i.e. @p might have woken up, | |
2407 | * then return zero. When we succeed in waiting for @p to be off its CPU, | |
2408 | * we return a positive number (its total switch count). If a second call | |
2409 | * a short while later returns the same number, the caller can be sure that | |
2410 | * @p has remained unscheduled the whole time. | |
2411 | * | |
1da177e4 LT |
2412 | * The caller must ensure that the task *will* unschedule sometime soon, |
2413 | * else this function might spin for a *long* time. This function can't | |
2414 | * be called with interrupts off, or it may introduce deadlock with | |
2415 | * smp_call_function() if an IPI is sent by the same process we are | |
2416 | * waiting to become inactive. | |
2417 | */ | |
85ba2d86 | 2418 | unsigned long wait_task_inactive(struct task_struct *p, long match_state) |
1da177e4 LT |
2419 | { |
2420 | unsigned long flags; | |
dd41f596 | 2421 | int running, on_rq; |
85ba2d86 | 2422 | unsigned long ncsw; |
70b97a7f | 2423 | struct rq *rq; |
1da177e4 | 2424 | |
3a5c359a AK |
2425 | for (;;) { |
2426 | /* | |
2427 | * We do the initial early heuristics without holding | |
2428 | * any task-queue locks at all. We'll only try to get | |
2429 | * the runqueue lock when things look like they will | |
2430 | * work out! | |
2431 | */ | |
2432 | rq = task_rq(p); | |
fa490cfd | 2433 | |
3a5c359a AK |
2434 | /* |
2435 | * If the task is actively running on another CPU | |
2436 | * still, just relax and busy-wait without holding | |
2437 | * any locks. | |
2438 | * | |
2439 | * NOTE! Since we don't hold any locks, it's not | |
2440 | * even sure that "rq" stays as the right runqueue! | |
2441 | * But we don't care, since "task_running()" will | |
2442 | * return false if the runqueue has changed and p | |
2443 | * is actually now running somewhere else! | |
2444 | */ | |
85ba2d86 RM |
2445 | while (task_running(rq, p)) { |
2446 | if (match_state && unlikely(p->state != match_state)) | |
2447 | return 0; | |
3a5c359a | 2448 | cpu_relax(); |
85ba2d86 | 2449 | } |
fa490cfd | 2450 | |
3a5c359a AK |
2451 | /* |
2452 | * Ok, time to look more closely! We need the rq | |
2453 | * lock now, to be *sure*. If we're wrong, we'll | |
2454 | * just go back and repeat. | |
2455 | */ | |
2456 | rq = task_rq_lock(p, &flags); | |
27a9da65 | 2457 | trace_sched_wait_task(p); |
3a5c359a | 2458 | running = task_running(rq, p); |
fd2f4419 | 2459 | on_rq = p->on_rq; |
85ba2d86 | 2460 | ncsw = 0; |
f31e11d8 | 2461 | if (!match_state || p->state == match_state) |
93dcf55f | 2462 | ncsw = p->nvcsw | LONG_MIN; /* sets MSB */ |
0122ec5b | 2463 | task_rq_unlock(rq, p, &flags); |
fa490cfd | 2464 | |
85ba2d86 RM |
2465 | /* |
2466 | * If it changed from the expected state, bail out now. | |
2467 | */ | |
2468 | if (unlikely(!ncsw)) | |
2469 | break; | |
2470 | ||
3a5c359a AK |
2471 | /* |
2472 | * Was it really running after all now that we | |
2473 | * checked with the proper locks actually held? | |
2474 | * | |
2475 | * Oops. Go back and try again.. | |
2476 | */ | |
2477 | if (unlikely(running)) { | |
2478 | cpu_relax(); | |
2479 | continue; | |
2480 | } | |
fa490cfd | 2481 | |
3a5c359a AK |
2482 | /* |
2483 | * It's not enough that it's not actively running, | |
2484 | * it must be off the runqueue _entirely_, and not | |
2485 | * preempted! | |
2486 | * | |
80dd99b3 | 2487 | * So if it was still runnable (but just not actively |
3a5c359a AK |
2488 | * running right now), it's preempted, and we should |
2489 | * yield - it could be a while. | |
2490 | */ | |
2491 | if (unlikely(on_rq)) { | |
8eb90c30 TG |
2492 | ktime_t to = ktime_set(0, NSEC_PER_SEC/HZ); |
2493 | ||
2494 | set_current_state(TASK_UNINTERRUPTIBLE); | |
2495 | schedule_hrtimeout(&to, HRTIMER_MODE_REL); | |
3a5c359a AK |
2496 | continue; |
2497 | } | |
fa490cfd | 2498 | |
3a5c359a AK |
2499 | /* |
2500 | * Ahh, all good. It wasn't running, and it wasn't | |
2501 | * runnable, which means that it will never become | |
2502 | * running in the future either. We're all done! | |
2503 | */ | |
2504 | break; | |
2505 | } | |
85ba2d86 RM |
2506 | |
2507 | return ncsw; | |
1da177e4 LT |
2508 | } |
2509 | ||
2510 | /*** | |
2511 | * kick_process - kick a running thread to enter/exit the kernel | |
2512 | * @p: the to-be-kicked thread | |
2513 | * | |
2514 | * Cause a process which is running on another CPU to enter | |
2515 | * kernel-mode, without any delay. (to get signals handled.) | |
2516 | * | |
25985edc | 2517 | * NOTE: this function doesn't have to take the runqueue lock, |
1da177e4 LT |
2518 | * because all it wants to ensure is that the remote task enters |
2519 | * the kernel. If the IPI races and the task has been migrated | |
2520 | * to another CPU then no harm is done and the purpose has been | |
2521 | * achieved as well. | |
2522 | */ | |
36c8b586 | 2523 | void kick_process(struct task_struct *p) |
1da177e4 LT |
2524 | { |
2525 | int cpu; | |
2526 | ||
2527 | preempt_disable(); | |
2528 | cpu = task_cpu(p); | |
2529 | if ((cpu != smp_processor_id()) && task_curr(p)) | |
2530 | smp_send_reschedule(cpu); | |
2531 | preempt_enable(); | |
2532 | } | |
b43e3521 | 2533 | EXPORT_SYMBOL_GPL(kick_process); |
476d139c | 2534 | #endif /* CONFIG_SMP */ |
1da177e4 | 2535 | |
970b13ba | 2536 | #ifdef CONFIG_SMP |
30da688e | 2537 | /* |
013fdb80 | 2538 | * ->cpus_allowed is protected by both rq->lock and p->pi_lock |
30da688e | 2539 | */ |
5da9a0fb PZ |
2540 | static int select_fallback_rq(int cpu, struct task_struct *p) |
2541 | { | |
2542 | int dest_cpu; | |
2543 | const struct cpumask *nodemask = cpumask_of_node(cpu_to_node(cpu)); | |
2544 | ||
2545 | /* Look for allowed, online CPU in same node. */ | |
2546 | for_each_cpu_and(dest_cpu, nodemask, cpu_active_mask) | |
2547 | if (cpumask_test_cpu(dest_cpu, &p->cpus_allowed)) | |
2548 | return dest_cpu; | |
2549 | ||
2550 | /* Any allowed, online CPU? */ | |
2551 | dest_cpu = cpumask_any_and(&p->cpus_allowed, cpu_active_mask); | |
2552 | if (dest_cpu < nr_cpu_ids) | |
2553 | return dest_cpu; | |
2554 | ||
2555 | /* No more Mr. Nice Guy. */ | |
48c5ccae PZ |
2556 | dest_cpu = cpuset_cpus_allowed_fallback(p); |
2557 | /* | |
2558 | * Don't tell them about moving exiting tasks or | |
2559 | * kernel threads (both mm NULL), since they never | |
2560 | * leave kernel. | |
2561 | */ | |
2562 | if (p->mm && printk_ratelimit()) { | |
2563 | printk(KERN_INFO "process %d (%s) no longer affine to cpu%d\n", | |
2564 | task_pid_nr(p), p->comm, cpu); | |
5da9a0fb PZ |
2565 | } |
2566 | ||
2567 | return dest_cpu; | |
2568 | } | |
2569 | ||
e2912009 | 2570 | /* |
013fdb80 | 2571 | * The caller (fork, wakeup) owns p->pi_lock, ->cpus_allowed is stable. |
e2912009 | 2572 | */ |
970b13ba | 2573 | static inline |
7608dec2 | 2574 | int select_task_rq(struct task_struct *p, int sd_flags, int wake_flags) |
970b13ba | 2575 | { |
7608dec2 | 2576 | int cpu = p->sched_class->select_task_rq(p, sd_flags, wake_flags); |
e2912009 PZ |
2577 | |
2578 | /* | |
2579 | * In order not to call set_task_cpu() on a blocking task we need | |
2580 | * to rely on ttwu() to place the task on a valid ->cpus_allowed | |
2581 | * cpu. | |
2582 | * | |
2583 | * Since this is common to all placement strategies, this lives here. | |
2584 | * | |
2585 | * [ this allows ->select_task() to simply return task_cpu(p) and | |
2586 | * not worry about this generic constraint ] | |
2587 | */ | |
2588 | if (unlikely(!cpumask_test_cpu(cpu, &p->cpus_allowed) || | |
70f11205 | 2589 | !cpu_online(cpu))) |
5da9a0fb | 2590 | cpu = select_fallback_rq(task_cpu(p), p); |
e2912009 PZ |
2591 | |
2592 | return cpu; | |
970b13ba | 2593 | } |
09a40af5 MG |
2594 | |
2595 | static void update_avg(u64 *avg, u64 sample) | |
2596 | { | |
2597 | s64 diff = sample - *avg; | |
2598 | *avg += diff >> 3; | |
2599 | } | |
970b13ba PZ |
2600 | #endif |
2601 | ||
d7c01d27 | 2602 | static void |
b84cb5df | 2603 | ttwu_stat(struct task_struct *p, int cpu, int wake_flags) |
9ed3811a | 2604 | { |
d7c01d27 | 2605 | #ifdef CONFIG_SCHEDSTATS |
b84cb5df PZ |
2606 | struct rq *rq = this_rq(); |
2607 | ||
d7c01d27 PZ |
2608 | #ifdef CONFIG_SMP |
2609 | int this_cpu = smp_processor_id(); | |
2610 | ||
2611 | if (cpu == this_cpu) { | |
2612 | schedstat_inc(rq, ttwu_local); | |
2613 | schedstat_inc(p, se.statistics.nr_wakeups_local); | |
2614 | } else { | |
2615 | struct sched_domain *sd; | |
2616 | ||
2617 | schedstat_inc(p, se.statistics.nr_wakeups_remote); | |
057f3fad | 2618 | rcu_read_lock(); |
d7c01d27 PZ |
2619 | for_each_domain(this_cpu, sd) { |
2620 | if (cpumask_test_cpu(cpu, sched_domain_span(sd))) { | |
2621 | schedstat_inc(sd, ttwu_wake_remote); | |
2622 | break; | |
2623 | } | |
2624 | } | |
057f3fad | 2625 | rcu_read_unlock(); |
d7c01d27 | 2626 | } |
f339b9dc PZ |
2627 | |
2628 | if (wake_flags & WF_MIGRATED) | |
2629 | schedstat_inc(p, se.statistics.nr_wakeups_migrate); | |
2630 | ||
d7c01d27 PZ |
2631 | #endif /* CONFIG_SMP */ |
2632 | ||
2633 | schedstat_inc(rq, ttwu_count); | |
9ed3811a | 2634 | schedstat_inc(p, se.statistics.nr_wakeups); |
d7c01d27 PZ |
2635 | |
2636 | if (wake_flags & WF_SYNC) | |
9ed3811a | 2637 | schedstat_inc(p, se.statistics.nr_wakeups_sync); |
d7c01d27 | 2638 | |
d7c01d27 PZ |
2639 | #endif /* CONFIG_SCHEDSTATS */ |
2640 | } | |
2641 | ||
2642 | static void ttwu_activate(struct rq *rq, struct task_struct *p, int en_flags) | |
2643 | { | |
9ed3811a | 2644 | activate_task(rq, p, en_flags); |
fd2f4419 | 2645 | p->on_rq = 1; |
c2f7115e PZ |
2646 | |
2647 | /* if a worker is waking up, notify workqueue */ | |
2648 | if (p->flags & PF_WQ_WORKER) | |
2649 | wq_worker_waking_up(p, cpu_of(rq)); | |
9ed3811a TH |
2650 | } |
2651 | ||
23f41eeb PZ |
2652 | /* |
2653 | * Mark the task runnable and perform wakeup-preemption. | |
2654 | */ | |
89363381 | 2655 | static void |
23f41eeb | 2656 | ttwu_do_wakeup(struct rq *rq, struct task_struct *p, int wake_flags) |
9ed3811a | 2657 | { |
89363381 | 2658 | trace_sched_wakeup(p, true); |
9ed3811a TH |
2659 | check_preempt_curr(rq, p, wake_flags); |
2660 | ||
2661 | p->state = TASK_RUNNING; | |
2662 | #ifdef CONFIG_SMP | |
2663 | if (p->sched_class->task_woken) | |
2664 | p->sched_class->task_woken(rq, p); | |
2665 | ||
e69c6341 | 2666 | if (rq->idle_stamp) { |
9ed3811a TH |
2667 | u64 delta = rq->clock - rq->idle_stamp; |
2668 | u64 max = 2*sysctl_sched_migration_cost; | |
2669 | ||
2670 | if (delta > max) | |
2671 | rq->avg_idle = max; | |
2672 | else | |
2673 | update_avg(&rq->avg_idle, delta); | |
2674 | rq->idle_stamp = 0; | |
2675 | } | |
2676 | #endif | |
2677 | } | |
2678 | ||
c05fbafb PZ |
2679 | static void |
2680 | ttwu_do_activate(struct rq *rq, struct task_struct *p, int wake_flags) | |
2681 | { | |
2682 | #ifdef CONFIG_SMP | |
2683 | if (p->sched_contributes_to_load) | |
2684 | rq->nr_uninterruptible--; | |
2685 | #endif | |
2686 | ||
2687 | ttwu_activate(rq, p, ENQUEUE_WAKEUP | ENQUEUE_WAKING); | |
2688 | ttwu_do_wakeup(rq, p, wake_flags); | |
2689 | } | |
2690 | ||
2691 | /* | |
2692 | * Called in case the task @p isn't fully descheduled from its runqueue, | |
2693 | * in this case we must do a remote wakeup. Its a 'light' wakeup though, | |
2694 | * since all we need to do is flip p->state to TASK_RUNNING, since | |
2695 | * the task is still ->on_rq. | |
2696 | */ | |
2697 | static int ttwu_remote(struct task_struct *p, int wake_flags) | |
2698 | { | |
2699 | struct rq *rq; | |
2700 | int ret = 0; | |
2701 | ||
2702 | rq = __task_rq_lock(p); | |
2703 | if (p->on_rq) { | |
2704 | ttwu_do_wakeup(rq, p, wake_flags); | |
2705 | ret = 1; | |
2706 | } | |
2707 | __task_rq_unlock(rq); | |
2708 | ||
2709 | return ret; | |
2710 | } | |
2711 | ||
317f3941 | 2712 | #ifdef CONFIG_SMP |
fa14ff4a | 2713 | static void sched_ttwu_pending(void) |
317f3941 PZ |
2714 | { |
2715 | struct rq *rq = this_rq(); | |
fa14ff4a PZ |
2716 | struct llist_node *llist = llist_del_all(&rq->wake_list); |
2717 | struct task_struct *p; | |
317f3941 PZ |
2718 | |
2719 | raw_spin_lock(&rq->lock); | |
2720 | ||
fa14ff4a PZ |
2721 | while (llist) { |
2722 | p = llist_entry(llist, struct task_struct, wake_entry); | |
2723 | llist = llist_next(llist); | |
317f3941 PZ |
2724 | ttwu_do_activate(rq, p, 0); |
2725 | } | |
2726 | ||
2727 | raw_spin_unlock(&rq->lock); | |
2728 | } | |
2729 | ||
2730 | void scheduler_ipi(void) | |
2731 | { | |
ca38062e | 2732 | if (llist_empty(&this_rq()->wake_list) && !got_nohz_idle_kick()) |
c5d753a5 PZ |
2733 | return; |
2734 | ||
2735 | /* | |
2736 | * Not all reschedule IPI handlers call irq_enter/irq_exit, since | |
2737 | * traditionally all their work was done from the interrupt return | |
2738 | * path. Now that we actually do some work, we need to make sure | |
2739 | * we do call them. | |
2740 | * | |
2741 | * Some archs already do call them, luckily irq_enter/exit nest | |
2742 | * properly. | |
2743 | * | |
2744 | * Arguably we should visit all archs and update all handlers, | |
2745 | * however a fair share of IPIs are still resched only so this would | |
2746 | * somewhat pessimize the simple resched case. | |
2747 | */ | |
2748 | irq_enter(); | |
fa14ff4a | 2749 | sched_ttwu_pending(); |
ca38062e SS |
2750 | |
2751 | /* | |
2752 | * Check if someone kicked us for doing the nohz idle load balance. | |
2753 | */ | |
2754 | if (unlikely(got_nohz_idle_kick() && !need_resched())) | |
2755 | raise_softirq_irqoff(SCHED_SOFTIRQ); | |
c5d753a5 | 2756 | irq_exit(); |
317f3941 PZ |
2757 | } |
2758 | ||
2759 | static void ttwu_queue_remote(struct task_struct *p, int cpu) | |
2760 | { | |
fa14ff4a | 2761 | if (llist_add(&p->wake_entry, &cpu_rq(cpu)->wake_list)) |
317f3941 PZ |
2762 | smp_send_reschedule(cpu); |
2763 | } | |
d6aa8f85 PZ |
2764 | |
2765 | #ifdef __ARCH_WANT_INTERRUPTS_ON_CTXSW | |
2766 | static int ttwu_activate_remote(struct task_struct *p, int wake_flags) | |
2767 | { | |
2768 | struct rq *rq; | |
2769 | int ret = 0; | |
2770 | ||
2771 | rq = __task_rq_lock(p); | |
2772 | if (p->on_cpu) { | |
2773 | ttwu_activate(rq, p, ENQUEUE_WAKEUP); | |
2774 | ttwu_do_wakeup(rq, p, wake_flags); | |
2775 | ret = 1; | |
2776 | } | |
2777 | __task_rq_unlock(rq); | |
2778 | ||
2779 | return ret; | |
2780 | ||
2781 | } | |
2782 | #endif /* __ARCH_WANT_INTERRUPTS_ON_CTXSW */ | |
2783 | #endif /* CONFIG_SMP */ | |
317f3941 | 2784 | |
c05fbafb PZ |
2785 | static void ttwu_queue(struct task_struct *p, int cpu) |
2786 | { | |
2787 | struct rq *rq = cpu_rq(cpu); | |
2788 | ||
17d9f311 | 2789 | #if defined(CONFIG_SMP) |
317f3941 | 2790 | if (sched_feat(TTWU_QUEUE) && cpu != smp_processor_id()) { |
f01114cb | 2791 | sched_clock_cpu(cpu); /* sync clocks x-cpu */ |
317f3941 PZ |
2792 | ttwu_queue_remote(p, cpu); |
2793 | return; | |
2794 | } | |
2795 | #endif | |
2796 | ||
c05fbafb PZ |
2797 | raw_spin_lock(&rq->lock); |
2798 | ttwu_do_activate(rq, p, 0); | |
2799 | raw_spin_unlock(&rq->lock); | |
9ed3811a TH |
2800 | } |
2801 | ||
2802 | /** | |
1da177e4 | 2803 | * try_to_wake_up - wake up a thread |
9ed3811a | 2804 | * @p: the thread to be awakened |
1da177e4 | 2805 | * @state: the mask of task states that can be woken |
9ed3811a | 2806 | * @wake_flags: wake modifier flags (WF_*) |
1da177e4 LT |
2807 | * |
2808 | * Put it on the run-queue if it's not already there. The "current" | |
2809 | * thread is always on the run-queue (except when the actual | |
2810 | * re-schedule is in progress), and as such you're allowed to do | |
2811 | * the simpler "current->state = TASK_RUNNING" to mark yourself | |
2812 | * runnable without the overhead of this. | |
2813 | * | |
9ed3811a TH |
2814 | * Returns %true if @p was woken up, %false if it was already running |
2815 | * or @state didn't match @p's state. | |
1da177e4 | 2816 | */ |
e4a52bcb PZ |
2817 | static int |
2818 | try_to_wake_up(struct task_struct *p, unsigned int state, int wake_flags) | |
1da177e4 | 2819 | { |
1da177e4 | 2820 | unsigned long flags; |
c05fbafb | 2821 | int cpu, success = 0; |
2398f2c6 | 2822 | |
04e2f174 | 2823 | smp_wmb(); |
013fdb80 | 2824 | raw_spin_lock_irqsave(&p->pi_lock, flags); |
e9c84311 | 2825 | if (!(p->state & state)) |
1da177e4 LT |
2826 | goto out; |
2827 | ||
c05fbafb | 2828 | success = 1; /* we're going to change ->state */ |
1da177e4 | 2829 | cpu = task_cpu(p); |
1da177e4 | 2830 | |
c05fbafb PZ |
2831 | if (p->on_rq && ttwu_remote(p, wake_flags)) |
2832 | goto stat; | |
1da177e4 | 2833 | |
1da177e4 | 2834 | #ifdef CONFIG_SMP |
e9c84311 | 2835 | /* |
c05fbafb PZ |
2836 | * If the owning (remote) cpu is still in the middle of schedule() with |
2837 | * this task as prev, wait until its done referencing the task. | |
e9c84311 | 2838 | */ |
e4a52bcb PZ |
2839 | while (p->on_cpu) { |
2840 | #ifdef __ARCH_WANT_INTERRUPTS_ON_CTXSW | |
2841 | /* | |
d6aa8f85 PZ |
2842 | * In case the architecture enables interrupts in |
2843 | * context_switch(), we cannot busy wait, since that | |
2844 | * would lead to deadlocks when an interrupt hits and | |
2845 | * tries to wake up @prev. So bail and do a complete | |
2846 | * remote wakeup. | |
e4a52bcb | 2847 | */ |
d6aa8f85 | 2848 | if (ttwu_activate_remote(p, wake_flags)) |
c05fbafb | 2849 | goto stat; |
d6aa8f85 | 2850 | #else |
e4a52bcb | 2851 | cpu_relax(); |
d6aa8f85 | 2852 | #endif |
371fd7e7 | 2853 | } |
0970d299 | 2854 | /* |
e4a52bcb | 2855 | * Pairs with the smp_wmb() in finish_lock_switch(). |
0970d299 | 2856 | */ |
e4a52bcb | 2857 | smp_rmb(); |
1da177e4 | 2858 | |
a8e4f2ea | 2859 | p->sched_contributes_to_load = !!task_contributes_to_load(p); |
e9c84311 | 2860 | p->state = TASK_WAKING; |
e7693a36 | 2861 | |
e4a52bcb | 2862 | if (p->sched_class->task_waking) |
74f8e4b2 | 2863 | p->sched_class->task_waking(p); |
efbbd05a | 2864 | |
7608dec2 | 2865 | cpu = select_task_rq(p, SD_BALANCE_WAKE, wake_flags); |
f339b9dc PZ |
2866 | if (task_cpu(p) != cpu) { |
2867 | wake_flags |= WF_MIGRATED; | |
e4a52bcb | 2868 | set_task_cpu(p, cpu); |
f339b9dc | 2869 | } |
1da177e4 | 2870 | #endif /* CONFIG_SMP */ |
1da177e4 | 2871 | |
c05fbafb PZ |
2872 | ttwu_queue(p, cpu); |
2873 | stat: | |
b84cb5df | 2874 | ttwu_stat(p, cpu, wake_flags); |
1da177e4 | 2875 | out: |
013fdb80 | 2876 | raw_spin_unlock_irqrestore(&p->pi_lock, flags); |
1da177e4 LT |
2877 | |
2878 | return success; | |
2879 | } | |
2880 | ||
21aa9af0 TH |
2881 | /** |
2882 | * try_to_wake_up_local - try to wake up a local task with rq lock held | |
2883 | * @p: the thread to be awakened | |
2884 | * | |
2acca55e | 2885 | * Put @p on the run-queue if it's not already there. The caller must |
21aa9af0 | 2886 | * ensure that this_rq() is locked, @p is bound to this_rq() and not |
2acca55e | 2887 | * the current task. |
21aa9af0 TH |
2888 | */ |
2889 | static void try_to_wake_up_local(struct task_struct *p) | |
2890 | { | |
2891 | struct rq *rq = task_rq(p); | |
21aa9af0 TH |
2892 | |
2893 | BUG_ON(rq != this_rq()); | |
2894 | BUG_ON(p == current); | |
2895 | lockdep_assert_held(&rq->lock); | |
2896 | ||
2acca55e PZ |
2897 | if (!raw_spin_trylock(&p->pi_lock)) { |
2898 | raw_spin_unlock(&rq->lock); | |
2899 | raw_spin_lock(&p->pi_lock); | |
2900 | raw_spin_lock(&rq->lock); | |
2901 | } | |
2902 | ||
21aa9af0 | 2903 | if (!(p->state & TASK_NORMAL)) |
2acca55e | 2904 | goto out; |
21aa9af0 | 2905 | |
fd2f4419 | 2906 | if (!p->on_rq) |
d7c01d27 PZ |
2907 | ttwu_activate(rq, p, ENQUEUE_WAKEUP); |
2908 | ||
23f41eeb | 2909 | ttwu_do_wakeup(rq, p, 0); |
b84cb5df | 2910 | ttwu_stat(p, smp_processor_id(), 0); |
2acca55e PZ |
2911 | out: |
2912 | raw_spin_unlock(&p->pi_lock); | |
21aa9af0 TH |
2913 | } |
2914 | ||
50fa610a DH |
2915 | /** |
2916 | * wake_up_process - Wake up a specific process | |
2917 | * @p: The process to be woken up. | |
2918 | * | |
2919 | * Attempt to wake up the nominated process and move it to the set of runnable | |
2920 | * processes. Returns 1 if the process was woken up, 0 if it was already | |
2921 | * running. | |
2922 | * | |
2923 | * It may be assumed that this function implies a write memory barrier before | |
2924 | * changing the task state if and only if any tasks are woken up. | |
2925 | */ | |
7ad5b3a5 | 2926 | int wake_up_process(struct task_struct *p) |
1da177e4 | 2927 | { |
d9514f6c | 2928 | return try_to_wake_up(p, TASK_ALL, 0); |
1da177e4 | 2929 | } |
1da177e4 LT |
2930 | EXPORT_SYMBOL(wake_up_process); |
2931 | ||
7ad5b3a5 | 2932 | int wake_up_state(struct task_struct *p, unsigned int state) |
1da177e4 LT |
2933 | { |
2934 | return try_to_wake_up(p, state, 0); | |
2935 | } | |
2936 | ||
1da177e4 LT |
2937 | /* |
2938 | * Perform scheduler related setup for a newly forked process p. | |
2939 | * p is forked by current. | |
dd41f596 IM |
2940 | * |
2941 | * __sched_fork() is basic setup used by init_idle() too: | |
2942 | */ | |
2943 | static void __sched_fork(struct task_struct *p) | |
2944 | { | |
fd2f4419 PZ |
2945 | p->on_rq = 0; |
2946 | ||
2947 | p->se.on_rq = 0; | |
dd41f596 IM |
2948 | p->se.exec_start = 0; |
2949 | p->se.sum_exec_runtime = 0; | |
f6cf891c | 2950 | p->se.prev_sum_exec_runtime = 0; |
6c594c21 | 2951 | p->se.nr_migrations = 0; |
da7a735e | 2952 | p->se.vruntime = 0; |
fd2f4419 | 2953 | INIT_LIST_HEAD(&p->se.group_node); |
6cfb0d5d IM |
2954 | |
2955 | #ifdef CONFIG_SCHEDSTATS | |
41acab88 | 2956 | memset(&p->se.statistics, 0, sizeof(p->se.statistics)); |
6cfb0d5d | 2957 | #endif |
476d139c | 2958 | |
fa717060 | 2959 | INIT_LIST_HEAD(&p->rt.run_list); |
476d139c | 2960 | |
e107be36 AK |
2961 | #ifdef CONFIG_PREEMPT_NOTIFIERS |
2962 | INIT_HLIST_HEAD(&p->preempt_notifiers); | |
2963 | #endif | |
dd41f596 IM |
2964 | } |
2965 | ||
2966 | /* | |
2967 | * fork()/clone()-time setup: | |
2968 | */ | |
3e51e3ed | 2969 | void sched_fork(struct task_struct *p) |
dd41f596 | 2970 | { |
0122ec5b | 2971 | unsigned long flags; |
dd41f596 IM |
2972 | int cpu = get_cpu(); |
2973 | ||
2974 | __sched_fork(p); | |
06b83b5f | 2975 | /* |
0017d735 | 2976 | * We mark the process as running here. This guarantees that |
06b83b5f PZ |
2977 | * nobody will actually run it, and a signal or other external |
2978 | * event cannot wake it up and insert it on the runqueue either. | |
2979 | */ | |
0017d735 | 2980 | p->state = TASK_RUNNING; |
dd41f596 | 2981 | |
c350a04e MG |
2982 | /* |
2983 | * Make sure we do not leak PI boosting priority to the child. | |
2984 | */ | |
2985 | p->prio = current->normal_prio; | |
2986 | ||
b9dc29e7 MG |
2987 | /* |
2988 | * Revert to default priority/policy on fork if requested. | |
2989 | */ | |
2990 | if (unlikely(p->sched_reset_on_fork)) { | |
c350a04e | 2991 | if (task_has_rt_policy(p)) { |
b9dc29e7 | 2992 | p->policy = SCHED_NORMAL; |
6c697bdf | 2993 | p->static_prio = NICE_TO_PRIO(0); |
c350a04e MG |
2994 | p->rt_priority = 0; |
2995 | } else if (PRIO_TO_NICE(p->static_prio) < 0) | |
2996 | p->static_prio = NICE_TO_PRIO(0); | |
2997 | ||
2998 | p->prio = p->normal_prio = __normal_prio(p); | |
2999 | set_load_weight(p); | |
6c697bdf | 3000 | |
b9dc29e7 MG |
3001 | /* |
3002 | * We don't need the reset flag anymore after the fork. It has | |
3003 | * fulfilled its duty: | |
3004 | */ | |
3005 | p->sched_reset_on_fork = 0; | |
3006 | } | |
ca94c442 | 3007 | |
2ddbf952 HS |
3008 | if (!rt_prio(p->prio)) |
3009 | p->sched_class = &fair_sched_class; | |
b29739f9 | 3010 | |
cd29fe6f PZ |
3011 | if (p->sched_class->task_fork) |
3012 | p->sched_class->task_fork(p); | |
3013 | ||
86951599 PZ |
3014 | /* |
3015 | * The child is not yet in the pid-hash so no cgroup attach races, | |
3016 | * and the cgroup is pinned to this child due to cgroup_fork() | |
3017 | * is ran before sched_fork(). | |
3018 | * | |
3019 | * Silence PROVE_RCU. | |
3020 | */ | |
0122ec5b | 3021 | raw_spin_lock_irqsave(&p->pi_lock, flags); |
5f3edc1b | 3022 | set_task_cpu(p, cpu); |
0122ec5b | 3023 | raw_spin_unlock_irqrestore(&p->pi_lock, flags); |
5f3edc1b | 3024 | |
52f17b6c | 3025 | #if defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT) |
dd41f596 | 3026 | if (likely(sched_info_on())) |
52f17b6c | 3027 | memset(&p->sched_info, 0, sizeof(p->sched_info)); |
1da177e4 | 3028 | #endif |
3ca7a440 PZ |
3029 | #if defined(CONFIG_SMP) |
3030 | p->on_cpu = 0; | |
4866cde0 | 3031 | #endif |
bdd4e85d | 3032 | #ifdef CONFIG_PREEMPT_COUNT |
4866cde0 | 3033 | /* Want to start with kernel preemption disabled. */ |
a1261f54 | 3034 | task_thread_info(p)->preempt_count = 1; |
1da177e4 | 3035 | #endif |
806c09a7 | 3036 | #ifdef CONFIG_SMP |
917b627d | 3037 | plist_node_init(&p->pushable_tasks, MAX_PRIO); |
806c09a7 | 3038 | #endif |
917b627d | 3039 | |
476d139c | 3040 | put_cpu(); |
1da177e4 LT |
3041 | } |
3042 | ||
3043 | /* | |
3044 | * wake_up_new_task - wake up a newly created task for the first time. | |
3045 | * | |
3046 | * This function will do some initial scheduler statistics housekeeping | |
3047 | * that must be done for every newly created context, then puts the task | |
3048 | * on the runqueue and wakes it. | |
3049 | */ | |
3e51e3ed | 3050 | void wake_up_new_task(struct task_struct *p) |
1da177e4 LT |
3051 | { |
3052 | unsigned long flags; | |
dd41f596 | 3053 | struct rq *rq; |
fabf318e | 3054 | |
ab2515c4 | 3055 | raw_spin_lock_irqsave(&p->pi_lock, flags); |
fabf318e PZ |
3056 | #ifdef CONFIG_SMP |
3057 | /* | |
3058 | * Fork balancing, do it here and not earlier because: | |
3059 | * - cpus_allowed can change in the fork path | |
3060 | * - any previously selected cpu might disappear through hotplug | |
fabf318e | 3061 | */ |
ab2515c4 | 3062 | set_task_cpu(p, select_task_rq(p, SD_BALANCE_FORK, 0)); |
0017d735 PZ |
3063 | #endif |
3064 | ||
ab2515c4 | 3065 | rq = __task_rq_lock(p); |
cd29fe6f | 3066 | activate_task(rq, p, 0); |
fd2f4419 | 3067 | p->on_rq = 1; |
89363381 | 3068 | trace_sched_wakeup_new(p, true); |
a7558e01 | 3069 | check_preempt_curr(rq, p, WF_FORK); |
9a897c5a | 3070 | #ifdef CONFIG_SMP |
efbbd05a PZ |
3071 | if (p->sched_class->task_woken) |
3072 | p->sched_class->task_woken(rq, p); | |
9a897c5a | 3073 | #endif |
0122ec5b | 3074 | task_rq_unlock(rq, p, &flags); |
1da177e4 LT |
3075 | } |
3076 | ||
e107be36 AK |
3077 | #ifdef CONFIG_PREEMPT_NOTIFIERS |
3078 | ||
3079 | /** | |
80dd99b3 | 3080 | * preempt_notifier_register - tell me when current is being preempted & rescheduled |
421cee29 | 3081 | * @notifier: notifier struct to register |
e107be36 AK |
3082 | */ |
3083 | void preempt_notifier_register(struct preempt_notifier *notifier) | |
3084 | { | |
3085 | hlist_add_head(¬ifier->link, ¤t->preempt_notifiers); | |
3086 | } | |
3087 | EXPORT_SYMBOL_GPL(preempt_notifier_register); | |
3088 | ||
3089 | /** | |
3090 | * preempt_notifier_unregister - no longer interested in preemption notifications | |
421cee29 | 3091 | * @notifier: notifier struct to unregister |
e107be36 AK |
3092 | * |
3093 | * This is safe to call from within a preemption notifier. | |
3094 | */ | |
3095 | void preempt_notifier_unregister(struct preempt_notifier *notifier) | |
3096 | { | |
3097 | hlist_del(¬ifier->link); | |
3098 | } | |
3099 | EXPORT_SYMBOL_GPL(preempt_notifier_unregister); | |
3100 | ||
3101 | static void fire_sched_in_preempt_notifiers(struct task_struct *curr) | |
3102 | { | |
3103 | struct preempt_notifier *notifier; | |
3104 | struct hlist_node *node; | |
3105 | ||
3106 | hlist_for_each_entry(notifier, node, &curr->preempt_notifiers, link) | |
3107 | notifier->ops->sched_in(notifier, raw_smp_processor_id()); | |
3108 | } | |
3109 | ||
3110 | static void | |
3111 | fire_sched_out_preempt_notifiers(struct task_struct *curr, | |
3112 | struct task_struct *next) | |
3113 | { | |
3114 | struct preempt_notifier *notifier; | |
3115 | struct hlist_node *node; | |
3116 | ||
3117 | hlist_for_each_entry(notifier, node, &curr->preempt_notifiers, link) | |
3118 | notifier->ops->sched_out(notifier, next); | |
3119 | } | |
3120 | ||
6d6bc0ad | 3121 | #else /* !CONFIG_PREEMPT_NOTIFIERS */ |
e107be36 AK |
3122 | |
3123 | static void fire_sched_in_preempt_notifiers(struct task_struct *curr) | |
3124 | { | |
3125 | } | |
3126 | ||
3127 | static void | |
3128 | fire_sched_out_preempt_notifiers(struct task_struct *curr, | |
3129 | struct task_struct *next) | |
3130 | { | |
3131 | } | |
3132 | ||
6d6bc0ad | 3133 | #endif /* CONFIG_PREEMPT_NOTIFIERS */ |
e107be36 | 3134 | |
4866cde0 NP |
3135 | /** |
3136 | * prepare_task_switch - prepare to switch tasks | |
3137 | * @rq: the runqueue preparing to switch | |
421cee29 | 3138 | * @prev: the current task that is being switched out |
4866cde0 NP |
3139 | * @next: the task we are going to switch to. |
3140 | * | |
3141 | * This is called with the rq lock held and interrupts off. It must | |
3142 | * be paired with a subsequent finish_task_switch after the context | |
3143 | * switch. | |
3144 | * | |
3145 | * prepare_task_switch sets up locking and calls architecture specific | |
3146 | * hooks. | |
3147 | */ | |
e107be36 AK |
3148 | static inline void |
3149 | prepare_task_switch(struct rq *rq, struct task_struct *prev, | |
3150 | struct task_struct *next) | |
4866cde0 | 3151 | { |
fe4b04fa PZ |
3152 | sched_info_switch(prev, next); |
3153 | perf_event_task_sched_out(prev, next); | |
e107be36 | 3154 | fire_sched_out_preempt_notifiers(prev, next); |
4866cde0 NP |
3155 | prepare_lock_switch(rq, next); |
3156 | prepare_arch_switch(next); | |
fe4b04fa | 3157 | trace_sched_switch(prev, next); |
4866cde0 NP |
3158 | } |
3159 | ||
1da177e4 LT |
3160 | /** |
3161 | * finish_task_switch - clean up after a task-switch | |
344babaa | 3162 | * @rq: runqueue associated with task-switch |
1da177e4 LT |
3163 | * @prev: the thread we just switched away from. |
3164 | * | |
4866cde0 NP |
3165 | * finish_task_switch must be called after the context switch, paired |
3166 | * with a prepare_task_switch call before the context switch. | |
3167 | * finish_task_switch will reconcile locking set up by prepare_task_switch, | |
3168 | * and do any other architecture-specific cleanup actions. | |
1da177e4 LT |
3169 | * |
3170 | * Note that we may have delayed dropping an mm in context_switch(). If | |
41a2d6cf | 3171 | * so, we finish that here outside of the runqueue lock. (Doing it |
1da177e4 LT |
3172 | * with the lock held can cause deadlocks; see schedule() for |
3173 | * details.) | |
3174 | */ | |
a9957449 | 3175 | static void finish_task_switch(struct rq *rq, struct task_struct *prev) |
1da177e4 LT |
3176 | __releases(rq->lock) |
3177 | { | |
1da177e4 | 3178 | struct mm_struct *mm = rq->prev_mm; |
55a101f8 | 3179 | long prev_state; |
1da177e4 LT |
3180 | |
3181 | rq->prev_mm = NULL; | |
3182 | ||
3183 | /* | |
3184 | * A task struct has one reference for the use as "current". | |
c394cc9f | 3185 | * If a task dies, then it sets TASK_DEAD in tsk->state and calls |
55a101f8 ON |
3186 | * schedule one last time. The schedule call will never return, and |
3187 | * the scheduled task must drop that reference. | |
c394cc9f | 3188 | * The test for TASK_DEAD must occur while the runqueue locks are |
1da177e4 LT |
3189 | * still held, otherwise prev could be scheduled on another cpu, die |
3190 | * there before we look at prev->state, and then the reference would | |
3191 | * be dropped twice. | |
3192 | * Manfred Spraul <manfred@colorfullife.com> | |
3193 | */ | |
55a101f8 | 3194 | prev_state = prev->state; |
4866cde0 | 3195 | finish_arch_switch(prev); |
8381f65d JI |
3196 | #ifdef __ARCH_WANT_INTERRUPTS_ON_CTXSW |
3197 | local_irq_disable(); | |
3198 | #endif /* __ARCH_WANT_INTERRUPTS_ON_CTXSW */ | |
a8d757ef | 3199 | perf_event_task_sched_in(prev, current); |
8381f65d JI |
3200 | #ifdef __ARCH_WANT_INTERRUPTS_ON_CTXSW |
3201 | local_irq_enable(); | |
3202 | #endif /* __ARCH_WANT_INTERRUPTS_ON_CTXSW */ | |
4866cde0 | 3203 | finish_lock_switch(rq, prev); |
e8fa1362 | 3204 | |
e107be36 | 3205 | fire_sched_in_preempt_notifiers(current); |
1da177e4 LT |
3206 | if (mm) |
3207 | mmdrop(mm); | |
c394cc9f | 3208 | if (unlikely(prev_state == TASK_DEAD)) { |
c6fd91f0 | 3209 | /* |
3210 | * Remove function-return probe instances associated with this | |
3211 | * task and put them back on the free list. | |
9761eea8 | 3212 | */ |
c6fd91f0 | 3213 | kprobe_flush_task(prev); |
1da177e4 | 3214 | put_task_struct(prev); |
c6fd91f0 | 3215 | } |
1da177e4 LT |
3216 | } |
3217 | ||
3f029d3c GH |
3218 | #ifdef CONFIG_SMP |
3219 | ||
3220 | /* assumes rq->lock is held */ | |
3221 | static inline void pre_schedule(struct rq *rq, struct task_struct *prev) | |
3222 | { | |
3223 | if (prev->sched_class->pre_schedule) | |
3224 | prev->sched_class->pre_schedule(rq, prev); | |
3225 | } | |
3226 | ||
3227 | /* rq->lock is NOT held, but preemption is disabled */ | |
3228 | static inline void post_schedule(struct rq *rq) | |
3229 | { | |
3230 | if (rq->post_schedule) { | |
3231 | unsigned long flags; | |
3232 | ||
05fa785c | 3233 | raw_spin_lock_irqsave(&rq->lock, flags); |
3f029d3c GH |
3234 | if (rq->curr->sched_class->post_schedule) |
3235 | rq->curr->sched_class->post_schedule(rq); | |
05fa785c | 3236 | raw_spin_unlock_irqrestore(&rq->lock, flags); |
3f029d3c GH |
3237 | |
3238 | rq->post_schedule = 0; | |
3239 | } | |
3240 | } | |
3241 | ||
3242 | #else | |
da19ab51 | 3243 | |
3f029d3c GH |
3244 | static inline void pre_schedule(struct rq *rq, struct task_struct *p) |
3245 | { | |
3246 | } | |
3247 | ||
3248 | static inline void post_schedule(struct rq *rq) | |
3249 | { | |
1da177e4 LT |
3250 | } |
3251 | ||
3f029d3c GH |
3252 | #endif |
3253 | ||
1da177e4 LT |
3254 | /** |
3255 | * schedule_tail - first thing a freshly forked thread must call. | |
3256 | * @prev: the thread we just switched away from. | |
3257 | */ | |
36c8b586 | 3258 | asmlinkage void schedule_tail(struct task_struct *prev) |
1da177e4 LT |
3259 | __releases(rq->lock) |
3260 | { | |
70b97a7f IM |
3261 | struct rq *rq = this_rq(); |
3262 | ||
4866cde0 | 3263 | finish_task_switch(rq, prev); |
da19ab51 | 3264 | |
3f029d3c GH |
3265 | /* |
3266 | * FIXME: do we need to worry about rq being invalidated by the | |
3267 | * task_switch? | |
3268 | */ | |
3269 | post_schedule(rq); | |
70b97a7f | 3270 | |
4866cde0 NP |
3271 | #ifdef __ARCH_WANT_UNLOCKED_CTXSW |
3272 | /* In this case, finish_task_switch does not reenable preemption */ | |
3273 | preempt_enable(); | |
3274 | #endif | |
1da177e4 | 3275 | if (current->set_child_tid) |
b488893a | 3276 | put_user(task_pid_vnr(current), current->set_child_tid); |
1da177e4 LT |
3277 | } |
3278 | ||
3279 | /* | |
3280 | * context_switch - switch to the new MM and the new | |
3281 | * thread's register state. | |
3282 | */ | |
dd41f596 | 3283 | static inline void |
70b97a7f | 3284 | context_switch(struct rq *rq, struct task_struct *prev, |
36c8b586 | 3285 | struct task_struct *next) |
1da177e4 | 3286 | { |
dd41f596 | 3287 | struct mm_struct *mm, *oldmm; |
1da177e4 | 3288 | |
e107be36 | 3289 | prepare_task_switch(rq, prev, next); |
fe4b04fa | 3290 | |
dd41f596 IM |
3291 | mm = next->mm; |
3292 | oldmm = prev->active_mm; | |
9226d125 ZA |
3293 | /* |
3294 | * For paravirt, this is coupled with an exit in switch_to to | |
3295 | * combine the page table reload and the switch backend into | |
3296 | * one hypercall. | |
3297 | */ | |
224101ed | 3298 | arch_start_context_switch(prev); |
9226d125 | 3299 | |
31915ab4 | 3300 | if (!mm) { |
1da177e4 LT |
3301 | next->active_mm = oldmm; |
3302 | atomic_inc(&oldmm->mm_count); | |
3303 | enter_lazy_tlb(oldmm, next); | |
3304 | } else | |
3305 | switch_mm(oldmm, mm, next); | |
3306 | ||
31915ab4 | 3307 | if (!prev->mm) { |
1da177e4 | 3308 | prev->active_mm = NULL; |
1da177e4 LT |
3309 | rq->prev_mm = oldmm; |
3310 | } | |
3a5f5e48 IM |
3311 | /* |
3312 | * Since the runqueue lock will be released by the next | |
3313 | * task (which is an invalid locking op but in the case | |
3314 | * of the scheduler it's an obvious special-case), so we | |
3315 | * do an early lockdep release here: | |
3316 | */ | |
3317 | #ifndef __ARCH_WANT_UNLOCKED_CTXSW | |
8a25d5de | 3318 | spin_release(&rq->lock.dep_map, 1, _THIS_IP_); |
3a5f5e48 | 3319 | #endif |
1da177e4 LT |
3320 | |
3321 | /* Here we just switch the register state and the stack. */ | |
3322 | switch_to(prev, next, prev); | |
3323 | ||
dd41f596 IM |
3324 | barrier(); |
3325 | /* | |
3326 | * this_rq must be evaluated again because prev may have moved | |
3327 | * CPUs since it called schedule(), thus the 'rq' on its stack | |
3328 | * frame will be invalid. | |
3329 | */ | |
3330 | finish_task_switch(this_rq(), prev); | |
1da177e4 LT |
3331 | } |
3332 | ||
3333 | /* | |
3334 | * nr_running, nr_uninterruptible and nr_context_switches: | |
3335 | * | |
3336 | * externally visible scheduler statistics: current number of runnable | |
3337 | * threads, current number of uninterruptible-sleeping threads, total | |
3338 | * number of context switches performed since bootup. | |
3339 | */ | |
3340 | unsigned long nr_running(void) | |
3341 | { | |
3342 | unsigned long i, sum = 0; | |
3343 | ||
3344 | for_each_online_cpu(i) | |
3345 | sum += cpu_rq(i)->nr_running; | |
3346 | ||
3347 | return sum; | |
f711f609 | 3348 | } |
1da177e4 LT |
3349 | |
3350 | unsigned long nr_uninterruptible(void) | |
f711f609 | 3351 | { |
1da177e4 | 3352 | unsigned long i, sum = 0; |
f711f609 | 3353 | |
0a945022 | 3354 | for_each_possible_cpu(i) |
1da177e4 | 3355 | sum += cpu_rq(i)->nr_uninterruptible; |
f711f609 GS |
3356 | |
3357 | /* | |
1da177e4 LT |
3358 | * Since we read the counters lockless, it might be slightly |
3359 | * inaccurate. Do not allow it to go below zero though: | |
f711f609 | 3360 | */ |
1da177e4 LT |
3361 | if (unlikely((long)sum < 0)) |
3362 | sum = 0; | |
f711f609 | 3363 | |
1da177e4 | 3364 | return sum; |
f711f609 | 3365 | } |
f711f609 | 3366 | |
1da177e4 | 3367 | unsigned long long nr_context_switches(void) |
46cb4b7c | 3368 | { |
cc94abfc SR |
3369 | int i; |
3370 | unsigned long long sum = 0; | |
46cb4b7c | 3371 | |
0a945022 | 3372 | for_each_possible_cpu(i) |
1da177e4 | 3373 | sum += cpu_rq(i)->nr_switches; |
46cb4b7c | 3374 | |
1da177e4 LT |
3375 | return sum; |
3376 | } | |
483b4ee6 | 3377 | |
1da177e4 LT |
3378 | unsigned long nr_iowait(void) |
3379 | { | |
3380 | unsigned long i, sum = 0; | |
483b4ee6 | 3381 | |
0a945022 | 3382 | for_each_possible_cpu(i) |
1da177e4 | 3383 | sum += atomic_read(&cpu_rq(i)->nr_iowait); |
46cb4b7c | 3384 | |
1da177e4 LT |
3385 | return sum; |
3386 | } | |
483b4ee6 | 3387 | |
8c215bd3 | 3388 | unsigned long nr_iowait_cpu(int cpu) |
69d25870 | 3389 | { |
8c215bd3 | 3390 | struct rq *this = cpu_rq(cpu); |
69d25870 AV |
3391 | return atomic_read(&this->nr_iowait); |
3392 | } | |
46cb4b7c | 3393 | |
69d25870 AV |
3394 | unsigned long this_cpu_load(void) |
3395 | { | |
3396 | struct rq *this = this_rq(); | |
3397 | return this->cpu_load[0]; | |
3398 | } | |
e790fb0b | 3399 | |
46cb4b7c | 3400 | |
dce48a84 TG |
3401 | /* Variables and functions for calc_load */ |
3402 | static atomic_long_t calc_load_tasks; | |
3403 | static unsigned long calc_load_update; | |
3404 | unsigned long avenrun[3]; | |
3405 | EXPORT_SYMBOL(avenrun); | |
46cb4b7c | 3406 | |
74f5187a PZ |
3407 | static long calc_load_fold_active(struct rq *this_rq) |
3408 | { | |
3409 | long nr_active, delta = 0; | |
3410 | ||
3411 | nr_active = this_rq->nr_running; | |
3412 | nr_active += (long) this_rq->nr_uninterruptible; | |
3413 | ||
3414 | if (nr_active != this_rq->calc_load_active) { | |
3415 | delta = nr_active - this_rq->calc_load_active; | |
3416 | this_rq->calc_load_active = nr_active; | |
3417 | } | |
3418 | ||
3419 | return delta; | |
3420 | } | |
3421 | ||
0f004f5a PZ |
3422 | static unsigned long |
3423 | calc_load(unsigned long load, unsigned long exp, unsigned long active) | |
3424 | { | |
3425 | load *= exp; | |
3426 | load += active * (FIXED_1 - exp); | |
3427 | load += 1UL << (FSHIFT - 1); | |
3428 | return load >> FSHIFT; | |
3429 | } | |
3430 | ||
74f5187a PZ |
3431 | #ifdef CONFIG_NO_HZ |
3432 | /* | |
3433 | * For NO_HZ we delay the active fold to the next LOAD_FREQ update. | |
3434 | * | |
3435 | * When making the ILB scale, we should try to pull this in as well. | |
3436 | */ | |
3437 | static atomic_long_t calc_load_tasks_idle; | |
3438 | ||
3439 | static void calc_load_account_idle(struct rq *this_rq) | |
3440 | { | |
3441 | long delta; | |
3442 | ||
3443 | delta = calc_load_fold_active(this_rq); | |
3444 | if (delta) | |
3445 | atomic_long_add(delta, &calc_load_tasks_idle); | |
3446 | } | |
3447 | ||
3448 | static long calc_load_fold_idle(void) | |
3449 | { | |
3450 | long delta = 0; | |
3451 | ||
3452 | /* | |
3453 | * Its got a race, we don't care... | |
3454 | */ | |
3455 | if (atomic_long_read(&calc_load_tasks_idle)) | |
3456 | delta = atomic_long_xchg(&calc_load_tasks_idle, 0); | |
3457 | ||
3458 | return delta; | |
3459 | } | |
0f004f5a PZ |
3460 | |
3461 | /** | |
3462 | * fixed_power_int - compute: x^n, in O(log n) time | |
3463 | * | |
3464 | * @x: base of the power | |
3465 | * @frac_bits: fractional bits of @x | |
3466 | * @n: power to raise @x to. | |
3467 | * | |
3468 | * By exploiting the relation between the definition of the natural power | |
3469 | * function: x^n := x*x*...*x (x multiplied by itself for n times), and | |
3470 | * the binary encoding of numbers used by computers: n := \Sum n_i * 2^i, | |
3471 | * (where: n_i \elem {0, 1}, the binary vector representing n), | |
3472 | * we find: x^n := x^(\Sum n_i * 2^i) := \Prod x^(n_i * 2^i), which is | |
3473 | * of course trivially computable in O(log_2 n), the length of our binary | |
3474 | * vector. | |
3475 | */ | |
3476 | static unsigned long | |
3477 | fixed_power_int(unsigned long x, unsigned int frac_bits, unsigned int n) | |
3478 | { | |
3479 | unsigned long result = 1UL << frac_bits; | |
3480 | ||
3481 | if (n) for (;;) { | |
3482 | if (n & 1) { | |
3483 | result *= x; | |
3484 | result += 1UL << (frac_bits - 1); | |
3485 | result >>= frac_bits; | |
3486 | } | |
3487 | n >>= 1; | |
3488 | if (!n) | |
3489 | break; | |
3490 | x *= x; | |
3491 | x += 1UL << (frac_bits - 1); | |
3492 | x >>= frac_bits; | |
3493 | } | |
3494 | ||
3495 | return result; | |
3496 | } | |
3497 | ||
3498 | /* | |
3499 | * a1 = a0 * e + a * (1 - e) | |
3500 | * | |
3501 | * a2 = a1 * e + a * (1 - e) | |
3502 | * = (a0 * e + a * (1 - e)) * e + a * (1 - e) | |
3503 | * = a0 * e^2 + a * (1 - e) * (1 + e) | |
3504 | * | |
3505 | * a3 = a2 * e + a * (1 - e) | |
3506 | * = (a0 * e^2 + a * (1 - e) * (1 + e)) * e + a * (1 - e) | |
3507 | * = a0 * e^3 + a * (1 - e) * (1 + e + e^2) | |
3508 | * | |
3509 | * ... | |
3510 | * | |
3511 | * an = a0 * e^n + a * (1 - e) * (1 + e + ... + e^n-1) [1] | |
3512 | * = a0 * e^n + a * (1 - e) * (1 - e^n)/(1 - e) | |
3513 | * = a0 * e^n + a * (1 - e^n) | |
3514 | * | |
3515 | * [1] application of the geometric series: | |
3516 | * | |
3517 | * n 1 - x^(n+1) | |
3518 | * S_n := \Sum x^i = ------------- | |
3519 | * i=0 1 - x | |
3520 | */ | |
3521 | static unsigned long | |
3522 | calc_load_n(unsigned long load, unsigned long exp, | |
3523 | unsigned long active, unsigned int n) | |
3524 | { | |
3525 | ||
3526 | return calc_load(load, fixed_power_int(exp, FSHIFT, n), active); | |
3527 | } | |
3528 | ||
3529 | /* | |
3530 | * NO_HZ can leave us missing all per-cpu ticks calling | |
3531 | * calc_load_account_active(), but since an idle CPU folds its delta into | |
3532 | * calc_load_tasks_idle per calc_load_account_idle(), all we need to do is fold | |
3533 | * in the pending idle delta if our idle period crossed a load cycle boundary. | |
3534 | * | |
3535 | * Once we've updated the global active value, we need to apply the exponential | |
3536 | * weights adjusted to the number of cycles missed. | |
3537 | */ | |
3538 | static void calc_global_nohz(unsigned long ticks) | |
3539 | { | |
3540 | long delta, active, n; | |
3541 | ||
3542 | if (time_before(jiffies, calc_load_update)) | |
3543 | return; | |
3544 | ||
3545 | /* | |
3546 | * If we crossed a calc_load_update boundary, make sure to fold | |
3547 | * any pending idle changes, the respective CPUs might have | |
3548 | * missed the tick driven calc_load_account_active() update | |
3549 | * due to NO_HZ. | |
3550 | */ | |
3551 | delta = calc_load_fold_idle(); | |
3552 | if (delta) | |
3553 | atomic_long_add(delta, &calc_load_tasks); | |
3554 | ||
3555 | /* | |
3556 | * If we were idle for multiple load cycles, apply them. | |
3557 | */ | |
3558 | if (ticks >= LOAD_FREQ) { | |
3559 | n = ticks / LOAD_FREQ; | |
3560 | ||
3561 | active = atomic_long_read(&calc_load_tasks); | |
3562 | active = active > 0 ? active * FIXED_1 : 0; | |
3563 | ||
3564 | avenrun[0] = calc_load_n(avenrun[0], EXP_1, active, n); | |
3565 | avenrun[1] = calc_load_n(avenrun[1], EXP_5, active, n); | |
3566 | avenrun[2] = calc_load_n(avenrun[2], EXP_15, active, n); | |
3567 | ||
3568 | calc_load_update += n * LOAD_FREQ; | |
3569 | } | |
3570 | ||
3571 | /* | |
3572 | * Its possible the remainder of the above division also crosses | |
3573 | * a LOAD_FREQ period, the regular check in calc_global_load() | |
3574 | * which comes after this will take care of that. | |
3575 | * | |
3576 | * Consider us being 11 ticks before a cycle completion, and us | |
3577 | * sleeping for 4*LOAD_FREQ + 22 ticks, then the above code will | |
3578 | * age us 4 cycles, and the test in calc_global_load() will | |
3579 | * pick up the final one. | |
3580 | */ | |
3581 | } | |
74f5187a PZ |
3582 | #else |
3583 | static void calc_load_account_idle(struct rq *this_rq) | |
3584 | { | |
3585 | } | |
3586 | ||
3587 | static inline long calc_load_fold_idle(void) | |
3588 | { | |
3589 | return 0; | |
3590 | } | |
0f004f5a PZ |
3591 | |
3592 | static void calc_global_nohz(unsigned long ticks) | |
3593 | { | |
3594 | } | |
74f5187a PZ |
3595 | #endif |
3596 | ||
2d02494f TG |
3597 | /** |
3598 | * get_avenrun - get the load average array | |
3599 | * @loads: pointer to dest load array | |
3600 | * @offset: offset to add | |
3601 | * @shift: shift count to shift the result left | |
3602 | * | |
3603 | * These values are estimates at best, so no need for locking. | |
3604 | */ | |
3605 | void get_avenrun(unsigned long *loads, unsigned long offset, int shift) | |
3606 | { | |
3607 | loads[0] = (avenrun[0] + offset) << shift; | |
3608 | loads[1] = (avenrun[1] + offset) << shift; | |
3609 | loads[2] = (avenrun[2] + offset) << shift; | |
46cb4b7c | 3610 | } |
46cb4b7c | 3611 | |
46cb4b7c | 3612 | /* |
dce48a84 TG |
3613 | * calc_load - update the avenrun load estimates 10 ticks after the |
3614 | * CPUs have updated calc_load_tasks. | |
7835b98b | 3615 | */ |
0f004f5a | 3616 | void calc_global_load(unsigned long ticks) |
7835b98b | 3617 | { |
dce48a84 | 3618 | long active; |
1da177e4 | 3619 | |
0f004f5a PZ |
3620 | calc_global_nohz(ticks); |
3621 | ||
3622 | if (time_before(jiffies, calc_load_update + 10)) | |
dce48a84 | 3623 | return; |
1da177e4 | 3624 | |
dce48a84 TG |
3625 | active = atomic_long_read(&calc_load_tasks); |
3626 | active = active > 0 ? active * FIXED_1 : 0; | |
1da177e4 | 3627 | |
dce48a84 TG |
3628 | avenrun[0] = calc_load(avenrun[0], EXP_1, active); |
3629 | avenrun[1] = calc_load(avenrun[1], EXP_5, active); | |
3630 | avenrun[2] = calc_load(avenrun[2], EXP_15, active); | |
dd41f596 | 3631 | |
dce48a84 TG |
3632 | calc_load_update += LOAD_FREQ; |
3633 | } | |
1da177e4 | 3634 | |
dce48a84 | 3635 | /* |
74f5187a PZ |
3636 | * Called from update_cpu_load() to periodically update this CPU's |
3637 | * active count. | |
dce48a84 TG |
3638 | */ |
3639 | static void calc_load_account_active(struct rq *this_rq) | |
3640 | { | |
74f5187a | 3641 | long delta; |
08c183f3 | 3642 | |
74f5187a PZ |
3643 | if (time_before(jiffies, this_rq->calc_load_update)) |
3644 | return; | |
783609c6 | 3645 | |
74f5187a PZ |
3646 | delta = calc_load_fold_active(this_rq); |
3647 | delta += calc_load_fold_idle(); | |
3648 | if (delta) | |
dce48a84 | 3649 | atomic_long_add(delta, &calc_load_tasks); |
74f5187a PZ |
3650 | |
3651 | this_rq->calc_load_update += LOAD_FREQ; | |
46cb4b7c SS |
3652 | } |
3653 | ||
fdf3e95d VP |
3654 | /* |
3655 | * The exact cpuload at various idx values, calculated at every tick would be | |
3656 | * load = (2^idx - 1) / 2^idx * load + 1 / 2^idx * cur_load | |
3657 | * | |
3658 | * If a cpu misses updates for n-1 ticks (as it was idle) and update gets called | |
3659 | * on nth tick when cpu may be busy, then we have: | |
3660 | * load = ((2^idx - 1) / 2^idx)^(n-1) * load | |
3661 | * load = (2^idx - 1) / 2^idx) * load + 1 / 2^idx * cur_load | |
3662 | * | |
3663 | * decay_load_missed() below does efficient calculation of | |
3664 | * load = ((2^idx - 1) / 2^idx)^(n-1) * load | |
3665 | * avoiding 0..n-1 loop doing load = ((2^idx - 1) / 2^idx) * load | |
3666 | * | |
3667 | * The calculation is approximated on a 128 point scale. | |
3668 | * degrade_zero_ticks is the number of ticks after which load at any | |
3669 | * particular idx is approximated to be zero. | |
3670 | * degrade_factor is a precomputed table, a row for each load idx. | |
3671 | * Each column corresponds to degradation factor for a power of two ticks, | |
3672 | * based on 128 point scale. | |
3673 | * Example: | |
3674 | * row 2, col 3 (=12) says that the degradation at load idx 2 after | |
3675 | * 8 ticks is 12/128 (which is an approximation of exact factor 3^8/4^8). | |
3676 | * | |
3677 | * With this power of 2 load factors, we can degrade the load n times | |
3678 | * by looking at 1 bits in n and doing as many mult/shift instead of | |
3679 | * n mult/shifts needed by the exact degradation. | |
3680 | */ | |
3681 | #define DEGRADE_SHIFT 7 | |
3682 | static const unsigned char | |
3683 | degrade_zero_ticks[CPU_LOAD_IDX_MAX] = {0, 8, 32, 64, 128}; | |
3684 | static const unsigned char | |
3685 | degrade_factor[CPU_LOAD_IDX_MAX][DEGRADE_SHIFT + 1] = { | |
3686 | {0, 0, 0, 0, 0, 0, 0, 0}, | |
3687 | {64, 32, 8, 0, 0, 0, 0, 0}, | |
3688 | {96, 72, 40, 12, 1, 0, 0}, | |
3689 | {112, 98, 75, 43, 15, 1, 0}, | |
3690 | {120, 112, 98, 76, 45, 16, 2} }; | |
3691 | ||
3692 | /* | |
3693 | * Update cpu_load for any missed ticks, due to tickless idle. The backlog | |
3694 | * would be when CPU is idle and so we just decay the old load without | |
3695 | * adding any new load. | |
3696 | */ | |
3697 | static unsigned long | |
3698 | decay_load_missed(unsigned long load, unsigned long missed_updates, int idx) | |
3699 | { | |
3700 | int j = 0; | |
3701 | ||
3702 | if (!missed_updates) | |
3703 | return load; | |
3704 | ||
3705 | if (missed_updates >= degrade_zero_ticks[idx]) | |
3706 | return 0; | |
3707 | ||
3708 | if (idx == 1) | |
3709 | return load >> missed_updates; | |
3710 | ||
3711 | while (missed_updates) { | |
3712 | if (missed_updates % 2) | |
3713 | load = (load * degrade_factor[idx][j]) >> DEGRADE_SHIFT; | |
3714 | ||
3715 | missed_updates >>= 1; | |
3716 | j++; | |
3717 | } | |
3718 | return load; | |
3719 | } | |
3720 | ||
46cb4b7c | 3721 | /* |
dd41f596 | 3722 | * Update rq->cpu_load[] statistics. This function is usually called every |
fdf3e95d VP |
3723 | * scheduler tick (TICK_NSEC). With tickless idle this will not be called |
3724 | * every tick. We fix it up based on jiffies. | |
46cb4b7c | 3725 | */ |
dd41f596 | 3726 | static void update_cpu_load(struct rq *this_rq) |
46cb4b7c | 3727 | { |
495eca49 | 3728 | unsigned long this_load = this_rq->load.weight; |
fdf3e95d VP |
3729 | unsigned long curr_jiffies = jiffies; |
3730 | unsigned long pending_updates; | |
dd41f596 | 3731 | int i, scale; |
46cb4b7c | 3732 | |
dd41f596 | 3733 | this_rq->nr_load_updates++; |
46cb4b7c | 3734 | |
fdf3e95d VP |
3735 | /* Avoid repeated calls on same jiffy, when moving in and out of idle */ |
3736 | if (curr_jiffies == this_rq->last_load_update_tick) | |
3737 | return; | |
3738 | ||
3739 | pending_updates = curr_jiffies - this_rq->last_load_update_tick; | |
3740 | this_rq->last_load_update_tick = curr_jiffies; | |
3741 | ||
dd41f596 | 3742 | /* Update our load: */ |
fdf3e95d VP |
3743 | this_rq->cpu_load[0] = this_load; /* Fasttrack for idx 0 */ |
3744 | for (i = 1, scale = 2; i < CPU_LOAD_IDX_MAX; i++, scale += scale) { | |
dd41f596 | 3745 | unsigned long old_load, new_load; |
7d1e6a9b | 3746 | |
dd41f596 | 3747 | /* scale is effectively 1 << i now, and >> i divides by scale */ |
46cb4b7c | 3748 | |
dd41f596 | 3749 | old_load = this_rq->cpu_load[i]; |
fdf3e95d | 3750 | old_load = decay_load_missed(old_load, pending_updates - 1, i); |
dd41f596 | 3751 | new_load = this_load; |
a25707f3 IM |
3752 | /* |
3753 | * Round up the averaging division if load is increasing. This | |
3754 | * prevents us from getting stuck on 9 if the load is 10, for | |
3755 | * example. | |
3756 | */ | |
3757 | if (new_load > old_load) | |
fdf3e95d VP |
3758 | new_load += scale - 1; |
3759 | ||
3760 | this_rq->cpu_load[i] = (old_load * (scale - 1) + new_load) >> i; | |
dd41f596 | 3761 | } |
da2b71ed SS |
3762 | |
3763 | sched_avg_update(this_rq); | |
fdf3e95d VP |
3764 | } |
3765 | ||
3766 | static void update_cpu_load_active(struct rq *this_rq) | |
3767 | { | |
3768 | update_cpu_load(this_rq); | |
46cb4b7c | 3769 | |
74f5187a | 3770 | calc_load_account_active(this_rq); |
46cb4b7c SS |
3771 | } |
3772 | ||
dd41f596 | 3773 | #ifdef CONFIG_SMP |
8a0be9ef | 3774 | |
46cb4b7c | 3775 | /* |
38022906 PZ |
3776 | * sched_exec - execve() is a valuable balancing opportunity, because at |
3777 | * this point the task has the smallest effective memory and cache footprint. | |
46cb4b7c | 3778 | */ |
38022906 | 3779 | void sched_exec(void) |
46cb4b7c | 3780 | { |
38022906 | 3781 | struct task_struct *p = current; |
1da177e4 | 3782 | unsigned long flags; |
0017d735 | 3783 | int dest_cpu; |
46cb4b7c | 3784 | |
8f42ced9 | 3785 | raw_spin_lock_irqsave(&p->pi_lock, flags); |
7608dec2 | 3786 | dest_cpu = p->sched_class->select_task_rq(p, SD_BALANCE_EXEC, 0); |
0017d735 PZ |
3787 | if (dest_cpu == smp_processor_id()) |
3788 | goto unlock; | |
38022906 | 3789 | |
8f42ced9 | 3790 | if (likely(cpu_active(dest_cpu))) { |
969c7921 | 3791 | struct migration_arg arg = { p, dest_cpu }; |
46cb4b7c | 3792 | |
8f42ced9 PZ |
3793 | raw_spin_unlock_irqrestore(&p->pi_lock, flags); |
3794 | stop_one_cpu(task_cpu(p), migration_cpu_stop, &arg); | |
1da177e4 LT |
3795 | return; |
3796 | } | |
0017d735 | 3797 | unlock: |
8f42ced9 | 3798 | raw_spin_unlock_irqrestore(&p->pi_lock, flags); |
1da177e4 | 3799 | } |
dd41f596 | 3800 | |
1da177e4 LT |
3801 | #endif |
3802 | ||
1da177e4 LT |
3803 | DEFINE_PER_CPU(struct kernel_stat, kstat); |
3804 | ||
3805 | EXPORT_PER_CPU_SYMBOL(kstat); | |
3806 | ||
3807 | /* | |
c5f8d995 | 3808 | * Return any ns on the sched_clock that have not yet been accounted in |
f06febc9 | 3809 | * @p in case that task is currently running. |
c5f8d995 HS |
3810 | * |
3811 | * Called with task_rq_lock() held on @rq. | |
1da177e4 | 3812 | */ |
c5f8d995 HS |
3813 | static u64 do_task_delta_exec(struct task_struct *p, struct rq *rq) |
3814 | { | |
3815 | u64 ns = 0; | |
3816 | ||
3817 | if (task_current(rq, p)) { | |
3818 | update_rq_clock(rq); | |
305e6835 | 3819 | ns = rq->clock_task - p->se.exec_start; |
c5f8d995 HS |
3820 | if ((s64)ns < 0) |
3821 | ns = 0; | |
3822 | } | |
3823 | ||
3824 | return ns; | |
3825 | } | |
3826 | ||
bb34d92f | 3827 | unsigned long long task_delta_exec(struct task_struct *p) |
1da177e4 | 3828 | { |
1da177e4 | 3829 | unsigned long flags; |
41b86e9c | 3830 | struct rq *rq; |
bb34d92f | 3831 | u64 ns = 0; |
48f24c4d | 3832 | |
41b86e9c | 3833 | rq = task_rq_lock(p, &flags); |
c5f8d995 | 3834 | ns = do_task_delta_exec(p, rq); |
0122ec5b | 3835 | task_rq_unlock(rq, p, &flags); |
1508487e | 3836 | |
c5f8d995 HS |
3837 | return ns; |
3838 | } | |
f06febc9 | 3839 | |
c5f8d995 HS |
3840 | /* |
3841 | * Return accounted runtime for the task. | |
3842 | * In case the task is currently running, return the runtime plus current's | |
3843 | * pending runtime that have not been accounted yet. | |
3844 | */ | |
3845 | unsigned long long task_sched_runtime(struct task_struct *p) | |
3846 | { | |
3847 | unsigned long flags; | |
3848 | struct rq *rq; | |
3849 | u64 ns = 0; | |
3850 | ||
3851 | rq = task_rq_lock(p, &flags); | |
3852 | ns = p->se.sum_exec_runtime + do_task_delta_exec(p, rq); | |
0122ec5b | 3853 | task_rq_unlock(rq, p, &flags); |
c5f8d995 HS |
3854 | |
3855 | return ns; | |
3856 | } | |
48f24c4d | 3857 | |
1da177e4 LT |
3858 | /* |
3859 | * Account user cpu time to a process. | |
3860 | * @p: the process that the cpu time gets accounted to | |
1da177e4 | 3861 | * @cputime: the cpu time spent in user space since the last update |
457533a7 | 3862 | * @cputime_scaled: cputime scaled by cpu frequency |
1da177e4 | 3863 | */ |
457533a7 MS |
3864 | void account_user_time(struct task_struct *p, cputime_t cputime, |
3865 | cputime_t cputime_scaled) | |
1da177e4 LT |
3866 | { |
3867 | struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat; | |
3868 | cputime64_t tmp; | |
3869 | ||
457533a7 | 3870 | /* Add user time to process. */ |
1da177e4 | 3871 | p->utime = cputime_add(p->utime, cputime); |
457533a7 | 3872 | p->utimescaled = cputime_add(p->utimescaled, cputime_scaled); |
f06febc9 | 3873 | account_group_user_time(p, cputime); |
1da177e4 LT |
3874 | |
3875 | /* Add user time to cpustat. */ | |
3876 | tmp = cputime_to_cputime64(cputime); | |
3877 | if (TASK_NICE(p) > 0) | |
3878 | cpustat->nice = cputime64_add(cpustat->nice, tmp); | |
3879 | else | |
3880 | cpustat->user = cputime64_add(cpustat->user, tmp); | |
ef12fefa BR |
3881 | |
3882 | cpuacct_update_stats(p, CPUACCT_STAT_USER, cputime); | |
49b5cf34 JL |
3883 | /* Account for user time used */ |
3884 | acct_update_integrals(p); | |
1da177e4 LT |
3885 | } |
3886 | ||
94886b84 LV |
3887 | /* |
3888 | * Account guest cpu time to a process. | |
3889 | * @p: the process that the cpu time gets accounted to | |
3890 | * @cputime: the cpu time spent in virtual machine since the last update | |
457533a7 | 3891 | * @cputime_scaled: cputime scaled by cpu frequency |
94886b84 | 3892 | */ |
457533a7 MS |
3893 | static void account_guest_time(struct task_struct *p, cputime_t cputime, |
3894 | cputime_t cputime_scaled) | |
94886b84 LV |
3895 | { |
3896 | cputime64_t tmp; | |
3897 | struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat; | |
3898 | ||
3899 | tmp = cputime_to_cputime64(cputime); | |
3900 | ||
457533a7 | 3901 | /* Add guest time to process. */ |
94886b84 | 3902 | p->utime = cputime_add(p->utime, cputime); |
457533a7 | 3903 | p->utimescaled = cputime_add(p->utimescaled, cputime_scaled); |
f06febc9 | 3904 | account_group_user_time(p, cputime); |
94886b84 LV |
3905 | p->gtime = cputime_add(p->gtime, cputime); |
3906 | ||
457533a7 | 3907 | /* Add guest time to cpustat. */ |
ce0e7b28 RO |
3908 | if (TASK_NICE(p) > 0) { |
3909 | cpustat->nice = cputime64_add(cpustat->nice, tmp); | |
3910 | cpustat->guest_nice = cputime64_add(cpustat->guest_nice, tmp); | |
3911 | } else { | |
3912 | cpustat->user = cputime64_add(cpustat->user, tmp); | |
3913 | cpustat->guest = cputime64_add(cpustat->guest, tmp); | |
3914 | } | |
94886b84 LV |
3915 | } |
3916 | ||
70a89a66 VP |
3917 | /* |
3918 | * Account system cpu time to a process and desired cpustat field | |
3919 | * @p: the process that the cpu time gets accounted to | |
3920 | * @cputime: the cpu time spent in kernel space since the last update | |
3921 | * @cputime_scaled: cputime scaled by cpu frequency | |
3922 | * @target_cputime64: pointer to cpustat field that has to be updated | |
3923 | */ | |
3924 | static inline | |
3925 | void __account_system_time(struct task_struct *p, cputime_t cputime, | |
3926 | cputime_t cputime_scaled, cputime64_t *target_cputime64) | |
3927 | { | |
3928 | cputime64_t tmp = cputime_to_cputime64(cputime); | |
3929 | ||
3930 | /* Add system time to process. */ | |
3931 | p->stime = cputime_add(p->stime, cputime); | |
3932 | p->stimescaled = cputime_add(p->stimescaled, cputime_scaled); | |
3933 | account_group_system_time(p, cputime); | |
3934 | ||
3935 | /* Add system time to cpustat. */ | |
3936 | *target_cputime64 = cputime64_add(*target_cputime64, tmp); | |
3937 | cpuacct_update_stats(p, CPUACCT_STAT_SYSTEM, cputime); | |
3938 | ||
3939 | /* Account for system time used */ | |
3940 | acct_update_integrals(p); | |
3941 | } | |
3942 | ||
1da177e4 LT |
3943 | /* |
3944 | * Account system cpu time to a process. | |
3945 | * @p: the process that the cpu time gets accounted to | |
3946 | * @hardirq_offset: the offset to subtract from hardirq_count() | |
3947 | * @cputime: the cpu time spent in kernel space since the last update | |
457533a7 | 3948 | * @cputime_scaled: cputime scaled by cpu frequency |
1da177e4 LT |
3949 | */ |
3950 | void account_system_time(struct task_struct *p, int hardirq_offset, | |
457533a7 | 3951 | cputime_t cputime, cputime_t cputime_scaled) |
1da177e4 LT |
3952 | { |
3953 | struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat; | |
70a89a66 | 3954 | cputime64_t *target_cputime64; |
1da177e4 | 3955 | |
983ed7a6 | 3956 | if ((p->flags & PF_VCPU) && (irq_count() - hardirq_offset == 0)) { |
457533a7 | 3957 | account_guest_time(p, cputime, cputime_scaled); |
983ed7a6 HH |
3958 | return; |
3959 | } | |
94886b84 | 3960 | |
1da177e4 | 3961 | if (hardirq_count() - hardirq_offset) |
70a89a66 | 3962 | target_cputime64 = &cpustat->irq; |
75e1056f | 3963 | else if (in_serving_softirq()) |
70a89a66 | 3964 | target_cputime64 = &cpustat->softirq; |
1da177e4 | 3965 | else |
70a89a66 | 3966 | target_cputime64 = &cpustat->system; |
ef12fefa | 3967 | |
70a89a66 | 3968 | __account_system_time(p, cputime, cputime_scaled, target_cputime64); |
1da177e4 LT |
3969 | } |
3970 | ||
c66f08be | 3971 | /* |
1da177e4 | 3972 | * Account for involuntary wait time. |
544b4a1f | 3973 | * @cputime: the cpu time spent in involuntary wait |
c66f08be | 3974 | */ |
79741dd3 | 3975 | void account_steal_time(cputime_t cputime) |
c66f08be | 3976 | { |
79741dd3 MS |
3977 | struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat; |
3978 | cputime64_t cputime64 = cputime_to_cputime64(cputime); | |
3979 | ||
3980 | cpustat->steal = cputime64_add(cpustat->steal, cputime64); | |
c66f08be MN |
3981 | } |
3982 | ||
1da177e4 | 3983 | /* |
79741dd3 MS |
3984 | * Account for idle time. |
3985 | * @cputime: the cpu time spent in idle wait | |
1da177e4 | 3986 | */ |
79741dd3 | 3987 | void account_idle_time(cputime_t cputime) |
1da177e4 LT |
3988 | { |
3989 | struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat; | |
79741dd3 | 3990 | cputime64_t cputime64 = cputime_to_cputime64(cputime); |
70b97a7f | 3991 | struct rq *rq = this_rq(); |
1da177e4 | 3992 | |
79741dd3 MS |
3993 | if (atomic_read(&rq->nr_iowait) > 0) |
3994 | cpustat->iowait = cputime64_add(cpustat->iowait, cputime64); | |
3995 | else | |
3996 | cpustat->idle = cputime64_add(cpustat->idle, cputime64); | |
1da177e4 LT |
3997 | } |
3998 | ||
e6e6685a GC |
3999 | static __always_inline bool steal_account_process_tick(void) |
4000 | { | |
4001 | #ifdef CONFIG_PARAVIRT | |
4002 | if (static_branch(¶virt_steal_enabled)) { | |
4003 | u64 steal, st = 0; | |
4004 | ||
4005 | steal = paravirt_steal_clock(smp_processor_id()); | |
4006 | steal -= this_rq()->prev_steal_time; | |
4007 | ||
4008 | st = steal_ticks(steal); | |
4009 | this_rq()->prev_steal_time += st * TICK_NSEC; | |
4010 | ||
4011 | account_steal_time(st); | |
4012 | return st; | |
4013 | } | |
4014 | #endif | |
4015 | return false; | |
4016 | } | |
4017 | ||
79741dd3 MS |
4018 | #ifndef CONFIG_VIRT_CPU_ACCOUNTING |
4019 | ||
abb74cef VP |
4020 | #ifdef CONFIG_IRQ_TIME_ACCOUNTING |
4021 | /* | |
4022 | * Account a tick to a process and cpustat | |
4023 | * @p: the process that the cpu time gets accounted to | |
4024 | * @user_tick: is the tick from userspace | |
4025 | * @rq: the pointer to rq | |
4026 | * | |
4027 | * Tick demultiplexing follows the order | |
4028 | * - pending hardirq update | |
4029 | * - pending softirq update | |
4030 | * - user_time | |
4031 | * - idle_time | |
4032 | * - system time | |
4033 | * - check for guest_time | |
4034 | * - else account as system_time | |
4035 | * | |
4036 | * Check for hardirq is done both for system and user time as there is | |
4037 | * no timer going off while we are on hardirq and hence we may never get an | |
4038 | * opportunity to update it solely in system time. | |
4039 | * p->stime and friends are only updated on system time and not on irq | |
4040 | * softirq as those do not count in task exec_runtime any more. | |
4041 | */ | |
4042 | static void irqtime_account_process_tick(struct task_struct *p, int user_tick, | |
4043 | struct rq *rq) | |
4044 | { | |
4045 | cputime_t one_jiffy_scaled = cputime_to_scaled(cputime_one_jiffy); | |
4046 | cputime64_t tmp = cputime_to_cputime64(cputime_one_jiffy); | |
4047 | struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat; | |
4048 | ||
e6e6685a GC |
4049 | if (steal_account_process_tick()) |
4050 | return; | |
4051 | ||
abb74cef VP |
4052 | if (irqtime_account_hi_update()) { |
4053 | cpustat->irq = cputime64_add(cpustat->irq, tmp); | |
4054 | } else if (irqtime_account_si_update()) { | |
4055 | cpustat->softirq = cputime64_add(cpustat->softirq, tmp); | |
414bee9b VP |
4056 | } else if (this_cpu_ksoftirqd() == p) { |
4057 | /* | |
4058 | * ksoftirqd time do not get accounted in cpu_softirq_time. | |
4059 | * So, we have to handle it separately here. | |
4060 | * Also, p->stime needs to be updated for ksoftirqd. | |
4061 | */ | |
4062 | __account_system_time(p, cputime_one_jiffy, one_jiffy_scaled, | |
4063 | &cpustat->softirq); | |
abb74cef VP |
4064 | } else if (user_tick) { |
4065 | account_user_time(p, cputime_one_jiffy, one_jiffy_scaled); | |
4066 | } else if (p == rq->idle) { | |
4067 | account_idle_time(cputime_one_jiffy); | |
4068 | } else if (p->flags & PF_VCPU) { /* System time or guest time */ | |
4069 | account_guest_time(p, cputime_one_jiffy, one_jiffy_scaled); | |
4070 | } else { | |
4071 | __account_system_time(p, cputime_one_jiffy, one_jiffy_scaled, | |
4072 | &cpustat->system); | |
4073 | } | |
4074 | } | |
4075 | ||
4076 | static void irqtime_account_idle_ticks(int ticks) | |
4077 | { | |
4078 | int i; | |
4079 | struct rq *rq = this_rq(); | |
4080 | ||
4081 | for (i = 0; i < ticks; i++) | |
4082 | irqtime_account_process_tick(current, 0, rq); | |
4083 | } | |
544b4a1f | 4084 | #else /* CONFIG_IRQ_TIME_ACCOUNTING */ |
abb74cef VP |
4085 | static void irqtime_account_idle_ticks(int ticks) {} |
4086 | static void irqtime_account_process_tick(struct task_struct *p, int user_tick, | |
4087 | struct rq *rq) {} | |
544b4a1f | 4088 | #endif /* CONFIG_IRQ_TIME_ACCOUNTING */ |
79741dd3 MS |
4089 | |
4090 | /* | |
4091 | * Account a single tick of cpu time. | |
4092 | * @p: the process that the cpu time gets accounted to | |
4093 | * @user_tick: indicates if the tick is a user or a system tick | |
4094 | */ | |
4095 | void account_process_tick(struct task_struct *p, int user_tick) | |
4096 | { | |
a42548a1 | 4097 | cputime_t one_jiffy_scaled = cputime_to_scaled(cputime_one_jiffy); |
79741dd3 MS |
4098 | struct rq *rq = this_rq(); |
4099 | ||
abb74cef VP |
4100 | if (sched_clock_irqtime) { |
4101 | irqtime_account_process_tick(p, user_tick, rq); | |
4102 | return; | |
4103 | } | |
4104 | ||
e6e6685a GC |
4105 | if (steal_account_process_tick()) |
4106 | return; | |
4107 | ||
79741dd3 | 4108 | if (user_tick) |
a42548a1 | 4109 | account_user_time(p, cputime_one_jiffy, one_jiffy_scaled); |
f5f293a4 | 4110 | else if ((p != rq->idle) || (irq_count() != HARDIRQ_OFFSET)) |
a42548a1 | 4111 | account_system_time(p, HARDIRQ_OFFSET, cputime_one_jiffy, |
79741dd3 MS |
4112 | one_jiffy_scaled); |
4113 | else | |
a42548a1 | 4114 | account_idle_time(cputime_one_jiffy); |
79741dd3 MS |
4115 | } |
4116 | ||
4117 | /* | |
4118 | * Account multiple ticks of steal time. | |
4119 | * @p: the process from which the cpu time has been stolen | |
4120 | * @ticks: number of stolen ticks | |
4121 | */ | |
4122 | void account_steal_ticks(unsigned long ticks) | |
4123 | { | |
4124 | account_steal_time(jiffies_to_cputime(ticks)); | |
4125 | } | |
4126 | ||
4127 | /* | |
4128 | * Account multiple ticks of idle time. | |
4129 | * @ticks: number of stolen ticks | |
4130 | */ | |
4131 | void account_idle_ticks(unsigned long ticks) | |
4132 | { | |
abb74cef VP |
4133 | |
4134 | if (sched_clock_irqtime) { | |
4135 | irqtime_account_idle_ticks(ticks); | |
4136 | return; | |
4137 | } | |
4138 | ||
79741dd3 | 4139 | account_idle_time(jiffies_to_cputime(ticks)); |
1da177e4 LT |
4140 | } |
4141 | ||
79741dd3 MS |
4142 | #endif |
4143 | ||
49048622 BS |
4144 | /* |
4145 | * Use precise platform statistics if available: | |
4146 | */ | |
4147 | #ifdef CONFIG_VIRT_CPU_ACCOUNTING | |
d180c5bc | 4148 | void task_times(struct task_struct *p, cputime_t *ut, cputime_t *st) |
49048622 | 4149 | { |
d99ca3b9 HS |
4150 | *ut = p->utime; |
4151 | *st = p->stime; | |
49048622 BS |
4152 | } |
4153 | ||
0cf55e1e | 4154 | void thread_group_times(struct task_struct *p, cputime_t *ut, cputime_t *st) |
49048622 | 4155 | { |
0cf55e1e HS |
4156 | struct task_cputime cputime; |
4157 | ||
4158 | thread_group_cputime(p, &cputime); | |
4159 | ||
4160 | *ut = cputime.utime; | |
4161 | *st = cputime.stime; | |
49048622 BS |
4162 | } |
4163 | #else | |
761b1d26 HS |
4164 | |
4165 | #ifndef nsecs_to_cputime | |
b7b20df9 | 4166 | # define nsecs_to_cputime(__nsecs) nsecs_to_jiffies(__nsecs) |
761b1d26 HS |
4167 | #endif |
4168 | ||
d180c5bc | 4169 | void task_times(struct task_struct *p, cputime_t *ut, cputime_t *st) |
49048622 | 4170 | { |
d99ca3b9 | 4171 | cputime_t rtime, utime = p->utime, total = cputime_add(utime, p->stime); |
49048622 BS |
4172 | |
4173 | /* | |
4174 | * Use CFS's precise accounting: | |
4175 | */ | |
d180c5bc | 4176 | rtime = nsecs_to_cputime(p->se.sum_exec_runtime); |
49048622 BS |
4177 | |
4178 | if (total) { | |
e75e863d | 4179 | u64 temp = rtime; |
d180c5bc | 4180 | |
e75e863d | 4181 | temp *= utime; |
49048622 | 4182 | do_div(temp, total); |
d180c5bc HS |
4183 | utime = (cputime_t)temp; |
4184 | } else | |
4185 | utime = rtime; | |
49048622 | 4186 | |
d180c5bc HS |
4187 | /* |
4188 | * Compare with previous values, to keep monotonicity: | |
4189 | */ | |
761b1d26 | 4190 | p->prev_utime = max(p->prev_utime, utime); |
d99ca3b9 | 4191 | p->prev_stime = max(p->prev_stime, cputime_sub(rtime, p->prev_utime)); |
49048622 | 4192 | |
d99ca3b9 HS |
4193 | *ut = p->prev_utime; |
4194 | *st = p->prev_stime; | |
49048622 BS |
4195 | } |
4196 | ||
0cf55e1e HS |
4197 | /* |
4198 | * Must be called with siglock held. | |
4199 | */ | |
4200 | void thread_group_times(struct task_struct *p, cputime_t *ut, cputime_t *st) | |
49048622 | 4201 | { |
0cf55e1e HS |
4202 | struct signal_struct *sig = p->signal; |
4203 | struct task_cputime cputime; | |
4204 | cputime_t rtime, utime, total; | |
49048622 | 4205 | |
0cf55e1e | 4206 | thread_group_cputime(p, &cputime); |
49048622 | 4207 | |
0cf55e1e HS |
4208 | total = cputime_add(cputime.utime, cputime.stime); |
4209 | rtime = nsecs_to_cputime(cputime.sum_exec_runtime); | |
49048622 | 4210 | |
0cf55e1e | 4211 | if (total) { |
e75e863d | 4212 | u64 temp = rtime; |
49048622 | 4213 | |
e75e863d | 4214 | temp *= cputime.utime; |
0cf55e1e HS |
4215 | do_div(temp, total); |
4216 | utime = (cputime_t)temp; | |
4217 | } else | |
4218 | utime = rtime; | |
4219 | ||
4220 | sig->prev_utime = max(sig->prev_utime, utime); | |
4221 | sig->prev_stime = max(sig->prev_stime, | |
4222 | cputime_sub(rtime, sig->prev_utime)); | |
4223 | ||
4224 | *ut = sig->prev_utime; | |
4225 | *st = sig->prev_stime; | |
49048622 | 4226 | } |
49048622 | 4227 | #endif |
49048622 | 4228 | |
7835b98b CL |
4229 | /* |
4230 | * This function gets called by the timer code, with HZ frequency. | |
4231 | * We call it with interrupts disabled. | |
7835b98b CL |
4232 | */ |
4233 | void scheduler_tick(void) | |
4234 | { | |
7835b98b CL |
4235 | int cpu = smp_processor_id(); |
4236 | struct rq *rq = cpu_rq(cpu); | |
dd41f596 | 4237 | struct task_struct *curr = rq->curr; |
3e51f33f PZ |
4238 | |
4239 | sched_clock_tick(); | |
dd41f596 | 4240 | |
05fa785c | 4241 | raw_spin_lock(&rq->lock); |
3e51f33f | 4242 | update_rq_clock(rq); |
fdf3e95d | 4243 | update_cpu_load_active(rq); |
fa85ae24 | 4244 | curr->sched_class->task_tick(rq, curr, 0); |
05fa785c | 4245 | raw_spin_unlock(&rq->lock); |
7835b98b | 4246 | |
e9d2b064 | 4247 | perf_event_task_tick(); |
e220d2dc | 4248 | |
e418e1c2 | 4249 | #ifdef CONFIG_SMP |
dd41f596 IM |
4250 | rq->idle_at_tick = idle_cpu(cpu); |
4251 | trigger_load_balance(rq, cpu); | |
e418e1c2 | 4252 | #endif |
1da177e4 LT |
4253 | } |
4254 | ||
132380a0 | 4255 | notrace unsigned long get_parent_ip(unsigned long addr) |
6cd8a4bb SR |
4256 | { |
4257 | if (in_lock_functions(addr)) { | |
4258 | addr = CALLER_ADDR2; | |
4259 | if (in_lock_functions(addr)) | |
4260 | addr = CALLER_ADDR3; | |
4261 | } | |
4262 | return addr; | |
4263 | } | |
1da177e4 | 4264 | |
7e49fcce SR |
4265 | #if defined(CONFIG_PREEMPT) && (defined(CONFIG_DEBUG_PREEMPT) || \ |
4266 | defined(CONFIG_PREEMPT_TRACER)) | |
4267 | ||
43627582 | 4268 | void __kprobes add_preempt_count(int val) |
1da177e4 | 4269 | { |
6cd8a4bb | 4270 | #ifdef CONFIG_DEBUG_PREEMPT |
1da177e4 LT |
4271 | /* |
4272 | * Underflow? | |
4273 | */ | |
9a11b49a IM |
4274 | if (DEBUG_LOCKS_WARN_ON((preempt_count() < 0))) |
4275 | return; | |
6cd8a4bb | 4276 | #endif |
1da177e4 | 4277 | preempt_count() += val; |
6cd8a4bb | 4278 | #ifdef CONFIG_DEBUG_PREEMPT |
1da177e4 LT |
4279 | /* |
4280 | * Spinlock count overflowing soon? | |
4281 | */ | |
33859f7f MOS |
4282 | DEBUG_LOCKS_WARN_ON((preempt_count() & PREEMPT_MASK) >= |
4283 | PREEMPT_MASK - 10); | |
6cd8a4bb SR |
4284 | #endif |
4285 | if (preempt_count() == val) | |
4286 | trace_preempt_off(CALLER_ADDR0, get_parent_ip(CALLER_ADDR1)); | |
1da177e4 LT |
4287 | } |
4288 | EXPORT_SYMBOL(add_preempt_count); | |
4289 | ||
43627582 | 4290 | void __kprobes sub_preempt_count(int val) |
1da177e4 | 4291 | { |
6cd8a4bb | 4292 | #ifdef CONFIG_DEBUG_PREEMPT |
1da177e4 LT |
4293 | /* |
4294 | * Underflow? | |
4295 | */ | |
01e3eb82 | 4296 | if (DEBUG_LOCKS_WARN_ON(val > preempt_count())) |
9a11b49a | 4297 | return; |
1da177e4 LT |
4298 | /* |
4299 | * Is the spinlock portion underflowing? | |
4300 | */ | |
9a11b49a IM |
4301 | if (DEBUG_LOCKS_WARN_ON((val < PREEMPT_MASK) && |
4302 | !(preempt_count() & PREEMPT_MASK))) | |
4303 | return; | |
6cd8a4bb | 4304 | #endif |
9a11b49a | 4305 | |
6cd8a4bb SR |
4306 | if (preempt_count() == val) |
4307 | trace_preempt_on(CALLER_ADDR0, get_parent_ip(CALLER_ADDR1)); | |
1da177e4 LT |
4308 | preempt_count() -= val; |
4309 | } | |
4310 | EXPORT_SYMBOL(sub_preempt_count); | |
4311 | ||
4312 | #endif | |
4313 | ||
4314 | /* | |
dd41f596 | 4315 | * Print scheduling while atomic bug: |
1da177e4 | 4316 | */ |
dd41f596 | 4317 | static noinline void __schedule_bug(struct task_struct *prev) |
1da177e4 | 4318 | { |
838225b4 SS |
4319 | struct pt_regs *regs = get_irq_regs(); |
4320 | ||
3df0fc5b PZ |
4321 | printk(KERN_ERR "BUG: scheduling while atomic: %s/%d/0x%08x\n", |
4322 | prev->comm, prev->pid, preempt_count()); | |
838225b4 | 4323 | |
dd41f596 | 4324 | debug_show_held_locks(prev); |
e21f5b15 | 4325 | print_modules(); |
dd41f596 IM |
4326 | if (irqs_disabled()) |
4327 | print_irqtrace_events(prev); | |
838225b4 SS |
4328 | |
4329 | if (regs) | |
4330 | show_regs(regs); | |
4331 | else | |
4332 | dump_stack(); | |
dd41f596 | 4333 | } |
1da177e4 | 4334 | |
dd41f596 IM |
4335 | /* |
4336 | * Various schedule()-time debugging checks and statistics: | |
4337 | */ | |
4338 | static inline void schedule_debug(struct task_struct *prev) | |
4339 | { | |
1da177e4 | 4340 | /* |
41a2d6cf | 4341 | * Test if we are atomic. Since do_exit() needs to call into |
1da177e4 LT |
4342 | * schedule() atomically, we ignore that path for now. |
4343 | * Otherwise, whine if we are scheduling when we should not be. | |
4344 | */ | |
3f33a7ce | 4345 | if (unlikely(in_atomic_preempt_off() && !prev->exit_state)) |
dd41f596 IM |
4346 | __schedule_bug(prev); |
4347 | ||
1da177e4 LT |
4348 | profile_hit(SCHED_PROFILING, __builtin_return_address(0)); |
4349 | ||
2d72376b | 4350 | schedstat_inc(this_rq(), sched_count); |
dd41f596 IM |
4351 | } |
4352 | ||
6cecd084 | 4353 | static void put_prev_task(struct rq *rq, struct task_struct *prev) |
df1c99d4 | 4354 | { |
61eadef6 | 4355 | if (prev->on_rq || rq->skip_clock_update < 0) |
a64692a3 | 4356 | update_rq_clock(rq); |
6cecd084 | 4357 | prev->sched_class->put_prev_task(rq, prev); |
df1c99d4 MG |
4358 | } |
4359 | ||
dd41f596 IM |
4360 | /* |
4361 | * Pick up the highest-prio task: | |
4362 | */ | |
4363 | static inline struct task_struct * | |
b67802ea | 4364 | pick_next_task(struct rq *rq) |
dd41f596 | 4365 | { |
5522d5d5 | 4366 | const struct sched_class *class; |
dd41f596 | 4367 | struct task_struct *p; |
1da177e4 LT |
4368 | |
4369 | /* | |
dd41f596 IM |
4370 | * Optimization: we know that if all tasks are in |
4371 | * the fair class we can call that function directly: | |
1da177e4 | 4372 | */ |
953bfcd1 | 4373 | if (likely(rq->nr_running == rq->cfs.h_nr_running)) { |
fb8d4724 | 4374 | p = fair_sched_class.pick_next_task(rq); |
dd41f596 IM |
4375 | if (likely(p)) |
4376 | return p; | |
1da177e4 LT |
4377 | } |
4378 | ||
34f971f6 | 4379 | for_each_class(class) { |
fb8d4724 | 4380 | p = class->pick_next_task(rq); |
dd41f596 IM |
4381 | if (p) |
4382 | return p; | |
dd41f596 | 4383 | } |
34f971f6 PZ |
4384 | |
4385 | BUG(); /* the idle class will always have a runnable task */ | |
dd41f596 | 4386 | } |
1da177e4 | 4387 | |
dd41f596 | 4388 | /* |
c259e01a | 4389 | * __schedule() is the main scheduler function. |
dd41f596 | 4390 | */ |
c259e01a | 4391 | static void __sched __schedule(void) |
dd41f596 IM |
4392 | { |
4393 | struct task_struct *prev, *next; | |
67ca7bde | 4394 | unsigned long *switch_count; |
dd41f596 | 4395 | struct rq *rq; |
31656519 | 4396 | int cpu; |
dd41f596 | 4397 | |
ff743345 PZ |
4398 | need_resched: |
4399 | preempt_disable(); | |
dd41f596 IM |
4400 | cpu = smp_processor_id(); |
4401 | rq = cpu_rq(cpu); | |
25502a6c | 4402 | rcu_note_context_switch(cpu); |
dd41f596 | 4403 | prev = rq->curr; |
dd41f596 | 4404 | |
dd41f596 | 4405 | schedule_debug(prev); |
1da177e4 | 4406 | |
31656519 | 4407 | if (sched_feat(HRTICK)) |
f333fdc9 | 4408 | hrtick_clear(rq); |
8f4d37ec | 4409 | |
05fa785c | 4410 | raw_spin_lock_irq(&rq->lock); |
1da177e4 | 4411 | |
246d86b5 | 4412 | switch_count = &prev->nivcsw; |
1da177e4 | 4413 | if (prev->state && !(preempt_count() & PREEMPT_ACTIVE)) { |
21aa9af0 | 4414 | if (unlikely(signal_pending_state(prev->state, prev))) { |
1da177e4 | 4415 | prev->state = TASK_RUNNING; |
21aa9af0 | 4416 | } else { |
2acca55e PZ |
4417 | deactivate_task(rq, prev, DEQUEUE_SLEEP); |
4418 | prev->on_rq = 0; | |
4419 | ||
21aa9af0 | 4420 | /* |
2acca55e PZ |
4421 | * If a worker went to sleep, notify and ask workqueue |
4422 | * whether it wants to wake up a task to maintain | |
4423 | * concurrency. | |
21aa9af0 TH |
4424 | */ |
4425 | if (prev->flags & PF_WQ_WORKER) { | |
4426 | struct task_struct *to_wakeup; | |
4427 | ||
4428 | to_wakeup = wq_worker_sleeping(prev, cpu); | |
4429 | if (to_wakeup) | |
4430 | try_to_wake_up_local(to_wakeup); | |
4431 | } | |
21aa9af0 | 4432 | } |
dd41f596 | 4433 | switch_count = &prev->nvcsw; |
1da177e4 LT |
4434 | } |
4435 | ||
3f029d3c | 4436 | pre_schedule(rq, prev); |
f65eda4f | 4437 | |
dd41f596 | 4438 | if (unlikely(!rq->nr_running)) |
1da177e4 | 4439 | idle_balance(cpu, rq); |
1da177e4 | 4440 | |
df1c99d4 | 4441 | put_prev_task(rq, prev); |
b67802ea | 4442 | next = pick_next_task(rq); |
f26f9aff MG |
4443 | clear_tsk_need_resched(prev); |
4444 | rq->skip_clock_update = 0; | |
1da177e4 | 4445 | |
1da177e4 | 4446 | if (likely(prev != next)) { |
1da177e4 LT |
4447 | rq->nr_switches++; |
4448 | rq->curr = next; | |
4449 | ++*switch_count; | |
4450 | ||
dd41f596 | 4451 | context_switch(rq, prev, next); /* unlocks the rq */ |
8f4d37ec | 4452 | /* |
246d86b5 ON |
4453 | * The context switch have flipped the stack from under us |
4454 | * and restored the local variables which were saved when | |
4455 | * this task called schedule() in the past. prev == current | |
4456 | * is still correct, but it can be moved to another cpu/rq. | |
8f4d37ec PZ |
4457 | */ |
4458 | cpu = smp_processor_id(); | |
4459 | rq = cpu_rq(cpu); | |
1da177e4 | 4460 | } else |
05fa785c | 4461 | raw_spin_unlock_irq(&rq->lock); |
1da177e4 | 4462 | |
3f029d3c | 4463 | post_schedule(rq); |
1da177e4 | 4464 | |
1da177e4 | 4465 | preempt_enable_no_resched(); |
ff743345 | 4466 | if (need_resched()) |
1da177e4 LT |
4467 | goto need_resched; |
4468 | } | |
c259e01a | 4469 | |
9c40cef2 TG |
4470 | static inline void sched_submit_work(struct task_struct *tsk) |
4471 | { | |
4472 | if (!tsk->state) | |
4473 | return; | |
4474 | /* | |
4475 | * If we are going to sleep and we have plugged IO queued, | |
4476 | * make sure to submit it to avoid deadlocks. | |
4477 | */ | |
4478 | if (blk_needs_flush_plug(tsk)) | |
4479 | blk_schedule_flush_plug(tsk); | |
4480 | } | |
4481 | ||
6ebbe7a0 | 4482 | asmlinkage void __sched schedule(void) |
c259e01a | 4483 | { |
9c40cef2 TG |
4484 | struct task_struct *tsk = current; |
4485 | ||
4486 | sched_submit_work(tsk); | |
c259e01a TG |
4487 | __schedule(); |
4488 | } | |
1da177e4 LT |
4489 | EXPORT_SYMBOL(schedule); |
4490 | ||
c08f7829 | 4491 | #ifdef CONFIG_MUTEX_SPIN_ON_OWNER |
0d66bf6d | 4492 | |
c6eb3dda PZ |
4493 | static inline bool owner_running(struct mutex *lock, struct task_struct *owner) |
4494 | { | |
c6eb3dda | 4495 | if (lock->owner != owner) |
307bf980 | 4496 | return false; |
0d66bf6d PZ |
4497 | |
4498 | /* | |
c6eb3dda PZ |
4499 | * Ensure we emit the owner->on_cpu, dereference _after_ checking |
4500 | * lock->owner still matches owner, if that fails, owner might | |
4501 | * point to free()d memory, if it still matches, the rcu_read_lock() | |
4502 | * ensures the memory stays valid. | |
0d66bf6d | 4503 | */ |
c6eb3dda | 4504 | barrier(); |
0d66bf6d | 4505 | |
307bf980 | 4506 | return owner->on_cpu; |
c6eb3dda | 4507 | } |
0d66bf6d | 4508 | |
c6eb3dda PZ |
4509 | /* |
4510 | * Look out! "owner" is an entirely speculative pointer | |
4511 | * access and not reliable. | |
4512 | */ | |
4513 | int mutex_spin_on_owner(struct mutex *lock, struct task_struct *owner) | |
4514 | { | |
4515 | if (!sched_feat(OWNER_SPIN)) | |
4516 | return 0; | |
0d66bf6d | 4517 | |
307bf980 | 4518 | rcu_read_lock(); |
c6eb3dda PZ |
4519 | while (owner_running(lock, owner)) { |
4520 | if (need_resched()) | |
307bf980 | 4521 | break; |
0d66bf6d | 4522 | |
335d7afb | 4523 | arch_mutex_cpu_relax(); |
0d66bf6d | 4524 | } |
307bf980 | 4525 | rcu_read_unlock(); |
4b402210 | 4526 | |
c6eb3dda | 4527 | /* |
307bf980 TG |
4528 | * We break out the loop above on need_resched() and when the |
4529 | * owner changed, which is a sign for heavy contention. Return | |
4530 | * success only when lock->owner is NULL. | |
c6eb3dda | 4531 | */ |
307bf980 | 4532 | return lock->owner == NULL; |
0d66bf6d PZ |
4533 | } |
4534 | #endif | |
4535 | ||
1da177e4 LT |
4536 | #ifdef CONFIG_PREEMPT |
4537 | /* | |
2ed6e34f | 4538 | * this is the entry point to schedule() from in-kernel preemption |
41a2d6cf | 4539 | * off of preempt_enable. Kernel preemptions off return from interrupt |
1da177e4 LT |
4540 | * occur there and call schedule directly. |
4541 | */ | |
d1f74e20 | 4542 | asmlinkage void __sched notrace preempt_schedule(void) |
1da177e4 LT |
4543 | { |
4544 | struct thread_info *ti = current_thread_info(); | |
6478d880 | 4545 | |
1da177e4 LT |
4546 | /* |
4547 | * If there is a non-zero preempt_count or interrupts are disabled, | |
41a2d6cf | 4548 | * we do not want to preempt the current task. Just return.. |
1da177e4 | 4549 | */ |
beed33a8 | 4550 | if (likely(ti->preempt_count || irqs_disabled())) |
1da177e4 LT |
4551 | return; |
4552 | ||
3a5c359a | 4553 | do { |
d1f74e20 | 4554 | add_preempt_count_notrace(PREEMPT_ACTIVE); |
c259e01a | 4555 | __schedule(); |
d1f74e20 | 4556 | sub_preempt_count_notrace(PREEMPT_ACTIVE); |
1da177e4 | 4557 | |
3a5c359a AK |
4558 | /* |
4559 | * Check again in case we missed a preemption opportunity | |
4560 | * between schedule and now. | |
4561 | */ | |
4562 | barrier(); | |
5ed0cec0 | 4563 | } while (need_resched()); |
1da177e4 | 4564 | } |
1da177e4 LT |
4565 | EXPORT_SYMBOL(preempt_schedule); |
4566 | ||
4567 | /* | |
2ed6e34f | 4568 | * this is the entry point to schedule() from kernel preemption |
1da177e4 LT |
4569 | * off of irq context. |
4570 | * Note, that this is called and return with irqs disabled. This will | |
4571 | * protect us against recursive calling from irq. | |
4572 | */ | |
4573 | asmlinkage void __sched preempt_schedule_irq(void) | |
4574 | { | |
4575 | struct thread_info *ti = current_thread_info(); | |
6478d880 | 4576 | |
2ed6e34f | 4577 | /* Catch callers which need to be fixed */ |
1da177e4 LT |
4578 | BUG_ON(ti->preempt_count || !irqs_disabled()); |
4579 | ||
3a5c359a AK |
4580 | do { |
4581 | add_preempt_count(PREEMPT_ACTIVE); | |
3a5c359a | 4582 | local_irq_enable(); |
c259e01a | 4583 | __schedule(); |
3a5c359a | 4584 | local_irq_disable(); |
3a5c359a | 4585 | sub_preempt_count(PREEMPT_ACTIVE); |
1da177e4 | 4586 | |
3a5c359a AK |
4587 | /* |
4588 | * Check again in case we missed a preemption opportunity | |
4589 | * between schedule and now. | |
4590 | */ | |
4591 | barrier(); | |
5ed0cec0 | 4592 | } while (need_resched()); |
1da177e4 LT |
4593 | } |
4594 | ||
4595 | #endif /* CONFIG_PREEMPT */ | |
4596 | ||
63859d4f | 4597 | int default_wake_function(wait_queue_t *curr, unsigned mode, int wake_flags, |
95cdf3b7 | 4598 | void *key) |
1da177e4 | 4599 | { |
63859d4f | 4600 | return try_to_wake_up(curr->private, mode, wake_flags); |
1da177e4 | 4601 | } |
1da177e4 LT |
4602 | EXPORT_SYMBOL(default_wake_function); |
4603 | ||
4604 | /* | |
41a2d6cf IM |
4605 | * The core wakeup function. Non-exclusive wakeups (nr_exclusive == 0) just |
4606 | * wake everything up. If it's an exclusive wakeup (nr_exclusive == small +ve | |
1da177e4 LT |
4607 | * number) then we wake all the non-exclusive tasks and one exclusive task. |
4608 | * | |
4609 | * There are circumstances in which we can try to wake a task which has already | |
41a2d6cf | 4610 | * started to run but is not in state TASK_RUNNING. try_to_wake_up() returns |
1da177e4 LT |
4611 | * zero in this (rare) case, and we handle it by continuing to scan the queue. |
4612 | */ | |
78ddb08f | 4613 | static void __wake_up_common(wait_queue_head_t *q, unsigned int mode, |
63859d4f | 4614 | int nr_exclusive, int wake_flags, void *key) |
1da177e4 | 4615 | { |
2e45874c | 4616 | wait_queue_t *curr, *next; |
1da177e4 | 4617 | |
2e45874c | 4618 | list_for_each_entry_safe(curr, next, &q->task_list, task_list) { |
48f24c4d IM |
4619 | unsigned flags = curr->flags; |
4620 | ||
63859d4f | 4621 | if (curr->func(curr, mode, wake_flags, key) && |
48f24c4d | 4622 | (flags & WQ_FLAG_EXCLUSIVE) && !--nr_exclusive) |
1da177e4 LT |
4623 | break; |
4624 | } | |
4625 | } | |
4626 | ||
4627 | /** | |
4628 | * __wake_up - wake up threads blocked on a waitqueue. | |
4629 | * @q: the waitqueue | |
4630 | * @mode: which threads | |
4631 | * @nr_exclusive: how many wake-one or wake-many threads to wake up | |
67be2dd1 | 4632 | * @key: is directly passed to the wakeup function |
50fa610a DH |
4633 | * |
4634 | * It may be assumed that this function implies a write memory barrier before | |
4635 | * changing the task state if and only if any tasks are woken up. | |
1da177e4 | 4636 | */ |
7ad5b3a5 | 4637 | void __wake_up(wait_queue_head_t *q, unsigned int mode, |
95cdf3b7 | 4638 | int nr_exclusive, void *key) |
1da177e4 LT |
4639 | { |
4640 | unsigned long flags; | |
4641 | ||
4642 | spin_lock_irqsave(&q->lock, flags); | |
4643 | __wake_up_common(q, mode, nr_exclusive, 0, key); | |
4644 | spin_unlock_irqrestore(&q->lock, flags); | |
4645 | } | |
1da177e4 LT |
4646 | EXPORT_SYMBOL(__wake_up); |
4647 | ||
4648 | /* | |
4649 | * Same as __wake_up but called with the spinlock in wait_queue_head_t held. | |
4650 | */ | |
7ad5b3a5 | 4651 | void __wake_up_locked(wait_queue_head_t *q, unsigned int mode) |
1da177e4 LT |
4652 | { |
4653 | __wake_up_common(q, mode, 1, 0, NULL); | |
4654 | } | |
22c43c81 | 4655 | EXPORT_SYMBOL_GPL(__wake_up_locked); |
1da177e4 | 4656 | |
4ede816a DL |
4657 | void __wake_up_locked_key(wait_queue_head_t *q, unsigned int mode, void *key) |
4658 | { | |
4659 | __wake_up_common(q, mode, 1, 0, key); | |
4660 | } | |
bf294b41 | 4661 | EXPORT_SYMBOL_GPL(__wake_up_locked_key); |
4ede816a | 4662 | |
1da177e4 | 4663 | /** |
4ede816a | 4664 | * __wake_up_sync_key - wake up threads blocked on a waitqueue. |
1da177e4 LT |
4665 | * @q: the waitqueue |
4666 | * @mode: which threads | |
4667 | * @nr_exclusive: how many wake-one or wake-many threads to wake up | |
4ede816a | 4668 | * @key: opaque value to be passed to wakeup targets |
1da177e4 LT |
4669 | * |
4670 | * The sync wakeup differs that the waker knows that it will schedule | |
4671 | * away soon, so while the target thread will be woken up, it will not | |
4672 | * be migrated to another CPU - ie. the two threads are 'synchronized' | |
4673 | * with each other. This can prevent needless bouncing between CPUs. | |
4674 | * | |
4675 | * On UP it can prevent extra preemption. | |
50fa610a DH |
4676 | * |
4677 | * It may be assumed that this function implies a write memory barrier before | |
4678 | * changing the task state if and only if any tasks are woken up. | |
1da177e4 | 4679 | */ |
4ede816a DL |
4680 | void __wake_up_sync_key(wait_queue_head_t *q, unsigned int mode, |
4681 | int nr_exclusive, void *key) | |
1da177e4 LT |
4682 | { |
4683 | unsigned long flags; | |
7d478721 | 4684 | int wake_flags = WF_SYNC; |
1da177e4 LT |
4685 | |
4686 | if (unlikely(!q)) | |
4687 | return; | |
4688 | ||
4689 | if (unlikely(!nr_exclusive)) | |
7d478721 | 4690 | wake_flags = 0; |
1da177e4 LT |
4691 | |
4692 | spin_lock_irqsave(&q->lock, flags); | |
7d478721 | 4693 | __wake_up_common(q, mode, nr_exclusive, wake_flags, key); |
1da177e4 LT |
4694 | spin_unlock_irqrestore(&q->lock, flags); |
4695 | } | |
4ede816a DL |
4696 | EXPORT_SYMBOL_GPL(__wake_up_sync_key); |
4697 | ||
4698 | /* | |
4699 | * __wake_up_sync - see __wake_up_sync_key() | |
4700 | */ | |
4701 | void __wake_up_sync(wait_queue_head_t *q, unsigned int mode, int nr_exclusive) | |
4702 | { | |
4703 | __wake_up_sync_key(q, mode, nr_exclusive, NULL); | |
4704 | } | |
1da177e4 LT |
4705 | EXPORT_SYMBOL_GPL(__wake_up_sync); /* For internal use only */ |
4706 | ||
65eb3dc6 KD |
4707 | /** |
4708 | * complete: - signals a single thread waiting on this completion | |
4709 | * @x: holds the state of this particular completion | |
4710 | * | |
4711 | * This will wake up a single thread waiting on this completion. Threads will be | |
4712 | * awakened in the same order in which they were queued. | |
4713 | * | |
4714 | * See also complete_all(), wait_for_completion() and related routines. | |
50fa610a DH |
4715 | * |
4716 | * It may be assumed that this function implies a write memory barrier before | |
4717 | * changing the task state if and only if any tasks are woken up. | |
65eb3dc6 | 4718 | */ |
b15136e9 | 4719 | void complete(struct completion *x) |
1da177e4 LT |
4720 | { |
4721 | unsigned long flags; | |
4722 | ||
4723 | spin_lock_irqsave(&x->wait.lock, flags); | |
4724 | x->done++; | |
d9514f6c | 4725 | __wake_up_common(&x->wait, TASK_NORMAL, 1, 0, NULL); |
1da177e4 LT |
4726 | spin_unlock_irqrestore(&x->wait.lock, flags); |
4727 | } | |
4728 | EXPORT_SYMBOL(complete); | |
4729 | ||
65eb3dc6 KD |
4730 | /** |
4731 | * complete_all: - signals all threads waiting on this completion | |
4732 | * @x: holds the state of this particular completion | |
4733 | * | |
4734 | * This will wake up all threads waiting on this particular completion event. | |
50fa610a DH |
4735 | * |
4736 | * It may be assumed that this function implies a write memory barrier before | |
4737 | * changing the task state if and only if any tasks are woken up. | |
65eb3dc6 | 4738 | */ |
b15136e9 | 4739 | void complete_all(struct completion *x) |
1da177e4 LT |
4740 | { |
4741 | unsigned long flags; | |
4742 | ||
4743 | spin_lock_irqsave(&x->wait.lock, flags); | |
4744 | x->done += UINT_MAX/2; | |
d9514f6c | 4745 | __wake_up_common(&x->wait, TASK_NORMAL, 0, 0, NULL); |
1da177e4 LT |
4746 | spin_unlock_irqrestore(&x->wait.lock, flags); |
4747 | } | |
4748 | EXPORT_SYMBOL(complete_all); | |
4749 | ||
8cbbe86d AK |
4750 | static inline long __sched |
4751 | do_wait_for_common(struct completion *x, long timeout, int state) | |
1da177e4 | 4752 | { |
1da177e4 LT |
4753 | if (!x->done) { |
4754 | DECLARE_WAITQUEUE(wait, current); | |
4755 | ||
a93d2f17 | 4756 | __add_wait_queue_tail_exclusive(&x->wait, &wait); |
1da177e4 | 4757 | do { |
94d3d824 | 4758 | if (signal_pending_state(state, current)) { |
ea71a546 ON |
4759 | timeout = -ERESTARTSYS; |
4760 | break; | |
8cbbe86d AK |
4761 | } |
4762 | __set_current_state(state); | |
1da177e4 LT |
4763 | spin_unlock_irq(&x->wait.lock); |
4764 | timeout = schedule_timeout(timeout); | |
4765 | spin_lock_irq(&x->wait.lock); | |
ea71a546 | 4766 | } while (!x->done && timeout); |
1da177e4 | 4767 | __remove_wait_queue(&x->wait, &wait); |
ea71a546 ON |
4768 | if (!x->done) |
4769 | return timeout; | |
1da177e4 LT |
4770 | } |
4771 | x->done--; | |
ea71a546 | 4772 | return timeout ?: 1; |
1da177e4 | 4773 | } |
1da177e4 | 4774 | |
8cbbe86d AK |
4775 | static long __sched |
4776 | wait_for_common(struct completion *x, long timeout, int state) | |
1da177e4 | 4777 | { |
1da177e4 LT |
4778 | might_sleep(); |
4779 | ||
4780 | spin_lock_irq(&x->wait.lock); | |
8cbbe86d | 4781 | timeout = do_wait_for_common(x, timeout, state); |
1da177e4 | 4782 | spin_unlock_irq(&x->wait.lock); |
8cbbe86d AK |
4783 | return timeout; |
4784 | } | |
1da177e4 | 4785 | |
65eb3dc6 KD |
4786 | /** |
4787 | * wait_for_completion: - waits for completion of a task | |
4788 | * @x: holds the state of this particular completion | |
4789 | * | |
4790 | * This waits to be signaled for completion of a specific task. It is NOT | |
4791 | * interruptible and there is no timeout. | |
4792 | * | |
4793 | * See also similar routines (i.e. wait_for_completion_timeout()) with timeout | |
4794 | * and interrupt capability. Also see complete(). | |
4795 | */ | |
b15136e9 | 4796 | void __sched wait_for_completion(struct completion *x) |
8cbbe86d AK |
4797 | { |
4798 | wait_for_common(x, MAX_SCHEDULE_TIMEOUT, TASK_UNINTERRUPTIBLE); | |
1da177e4 | 4799 | } |
8cbbe86d | 4800 | EXPORT_SYMBOL(wait_for_completion); |
1da177e4 | 4801 | |
65eb3dc6 KD |
4802 | /** |
4803 | * wait_for_completion_timeout: - waits for completion of a task (w/timeout) | |
4804 | * @x: holds the state of this particular completion | |
4805 | * @timeout: timeout value in jiffies | |
4806 | * | |
4807 | * This waits for either a completion of a specific task to be signaled or for a | |
4808 | * specified timeout to expire. The timeout is in jiffies. It is not | |
4809 | * interruptible. | |
4810 | */ | |
b15136e9 | 4811 | unsigned long __sched |
8cbbe86d | 4812 | wait_for_completion_timeout(struct completion *x, unsigned long timeout) |
1da177e4 | 4813 | { |
8cbbe86d | 4814 | return wait_for_common(x, timeout, TASK_UNINTERRUPTIBLE); |
1da177e4 | 4815 | } |
8cbbe86d | 4816 | EXPORT_SYMBOL(wait_for_completion_timeout); |
1da177e4 | 4817 | |
65eb3dc6 KD |
4818 | /** |
4819 | * wait_for_completion_interruptible: - waits for completion of a task (w/intr) | |
4820 | * @x: holds the state of this particular completion | |
4821 | * | |
4822 | * This waits for completion of a specific task to be signaled. It is | |
4823 | * interruptible. | |
4824 | */ | |
8cbbe86d | 4825 | int __sched wait_for_completion_interruptible(struct completion *x) |
0fec171c | 4826 | { |
51e97990 AK |
4827 | long t = wait_for_common(x, MAX_SCHEDULE_TIMEOUT, TASK_INTERRUPTIBLE); |
4828 | if (t == -ERESTARTSYS) | |
4829 | return t; | |
4830 | return 0; | |
0fec171c | 4831 | } |
8cbbe86d | 4832 | EXPORT_SYMBOL(wait_for_completion_interruptible); |
1da177e4 | 4833 | |
65eb3dc6 KD |
4834 | /** |
4835 | * wait_for_completion_interruptible_timeout: - waits for completion (w/(to,intr)) | |
4836 | * @x: holds the state of this particular completion | |
4837 | * @timeout: timeout value in jiffies | |
4838 | * | |
4839 | * This waits for either a completion of a specific task to be signaled or for a | |
4840 | * specified timeout to expire. It is interruptible. The timeout is in jiffies. | |
4841 | */ | |
6bf41237 | 4842 | long __sched |
8cbbe86d AK |
4843 | wait_for_completion_interruptible_timeout(struct completion *x, |
4844 | unsigned long timeout) | |
0fec171c | 4845 | { |
8cbbe86d | 4846 | return wait_for_common(x, timeout, TASK_INTERRUPTIBLE); |
0fec171c | 4847 | } |
8cbbe86d | 4848 | EXPORT_SYMBOL(wait_for_completion_interruptible_timeout); |
1da177e4 | 4849 | |
65eb3dc6 KD |
4850 | /** |
4851 | * wait_for_completion_killable: - waits for completion of a task (killable) | |
4852 | * @x: holds the state of this particular completion | |
4853 | * | |
4854 | * This waits to be signaled for completion of a specific task. It can be | |
4855 | * interrupted by a kill signal. | |
4856 | */ | |
009e577e MW |
4857 | int __sched wait_for_completion_killable(struct completion *x) |
4858 | { | |
4859 | long t = wait_for_common(x, MAX_SCHEDULE_TIMEOUT, TASK_KILLABLE); | |
4860 | if (t == -ERESTARTSYS) | |
4861 | return t; | |
4862 | return 0; | |
4863 | } | |
4864 | EXPORT_SYMBOL(wait_for_completion_killable); | |
4865 | ||
0aa12fb4 SW |
4866 | /** |
4867 | * wait_for_completion_killable_timeout: - waits for completion of a task (w/(to,killable)) | |
4868 | * @x: holds the state of this particular completion | |
4869 | * @timeout: timeout value in jiffies | |
4870 | * | |
4871 | * This waits for either a completion of a specific task to be | |
4872 | * signaled or for a specified timeout to expire. It can be | |
4873 | * interrupted by a kill signal. The timeout is in jiffies. | |
4874 | */ | |
6bf41237 | 4875 | long __sched |
0aa12fb4 SW |
4876 | wait_for_completion_killable_timeout(struct completion *x, |
4877 | unsigned long timeout) | |
4878 | { | |
4879 | return wait_for_common(x, timeout, TASK_KILLABLE); | |
4880 | } | |
4881 | EXPORT_SYMBOL(wait_for_completion_killable_timeout); | |
4882 | ||
be4de352 DC |
4883 | /** |
4884 | * try_wait_for_completion - try to decrement a completion without blocking | |
4885 | * @x: completion structure | |
4886 | * | |
4887 | * Returns: 0 if a decrement cannot be done without blocking | |
4888 | * 1 if a decrement succeeded. | |
4889 | * | |
4890 | * If a completion is being used as a counting completion, | |
4891 | * attempt to decrement the counter without blocking. This | |
4892 | * enables us to avoid waiting if the resource the completion | |
4893 | * is protecting is not available. | |
4894 | */ | |
4895 | bool try_wait_for_completion(struct completion *x) | |
4896 | { | |
7539a3b3 | 4897 | unsigned long flags; |
be4de352 DC |
4898 | int ret = 1; |
4899 | ||
7539a3b3 | 4900 | spin_lock_irqsave(&x->wait.lock, flags); |
be4de352 DC |
4901 | if (!x->done) |
4902 | ret = 0; | |
4903 | else | |
4904 | x->done--; | |
7539a3b3 | 4905 | spin_unlock_irqrestore(&x->wait.lock, flags); |
be4de352 DC |
4906 | return ret; |
4907 | } | |
4908 | EXPORT_SYMBOL(try_wait_for_completion); | |
4909 | ||
4910 | /** | |
4911 | * completion_done - Test to see if a completion has any waiters | |
4912 | * @x: completion structure | |
4913 | * | |
4914 | * Returns: 0 if there are waiters (wait_for_completion() in progress) | |
4915 | * 1 if there are no waiters. | |
4916 | * | |
4917 | */ | |
4918 | bool completion_done(struct completion *x) | |
4919 | { | |
7539a3b3 | 4920 | unsigned long flags; |
be4de352 DC |
4921 | int ret = 1; |
4922 | ||
7539a3b3 | 4923 | spin_lock_irqsave(&x->wait.lock, flags); |
be4de352 DC |
4924 | if (!x->done) |
4925 | ret = 0; | |
7539a3b3 | 4926 | spin_unlock_irqrestore(&x->wait.lock, flags); |
be4de352 DC |
4927 | return ret; |
4928 | } | |
4929 | EXPORT_SYMBOL(completion_done); | |
4930 | ||
8cbbe86d AK |
4931 | static long __sched |
4932 | sleep_on_common(wait_queue_head_t *q, int state, long timeout) | |
1da177e4 | 4933 | { |
0fec171c IM |
4934 | unsigned long flags; |
4935 | wait_queue_t wait; | |
4936 | ||
4937 | init_waitqueue_entry(&wait, current); | |
1da177e4 | 4938 | |
8cbbe86d | 4939 | __set_current_state(state); |
1da177e4 | 4940 | |
8cbbe86d AK |
4941 | spin_lock_irqsave(&q->lock, flags); |
4942 | __add_wait_queue(q, &wait); | |
4943 | spin_unlock(&q->lock); | |
4944 | timeout = schedule_timeout(timeout); | |
4945 | spin_lock_irq(&q->lock); | |
4946 | __remove_wait_queue(q, &wait); | |
4947 | spin_unlock_irqrestore(&q->lock, flags); | |
4948 | ||
4949 | return timeout; | |
4950 | } | |
4951 | ||
4952 | void __sched interruptible_sleep_on(wait_queue_head_t *q) | |
4953 | { | |
4954 | sleep_on_common(q, TASK_INTERRUPTIBLE, MAX_SCHEDULE_TIMEOUT); | |
1da177e4 | 4955 | } |
1da177e4 LT |
4956 | EXPORT_SYMBOL(interruptible_sleep_on); |
4957 | ||
0fec171c | 4958 | long __sched |
95cdf3b7 | 4959 | interruptible_sleep_on_timeout(wait_queue_head_t *q, long timeout) |
1da177e4 | 4960 | { |
8cbbe86d | 4961 | return sleep_on_common(q, TASK_INTERRUPTIBLE, timeout); |
1da177e4 | 4962 | } |
1da177e4 LT |
4963 | EXPORT_SYMBOL(interruptible_sleep_on_timeout); |
4964 | ||
0fec171c | 4965 | void __sched sleep_on(wait_queue_head_t *q) |
1da177e4 | 4966 | { |
8cbbe86d | 4967 | sleep_on_common(q, TASK_UNINTERRUPTIBLE, MAX_SCHEDULE_TIMEOUT); |
1da177e4 | 4968 | } |
1da177e4 LT |
4969 | EXPORT_SYMBOL(sleep_on); |
4970 | ||
0fec171c | 4971 | long __sched sleep_on_timeout(wait_queue_head_t *q, long timeout) |
1da177e4 | 4972 | { |
8cbbe86d | 4973 | return sleep_on_common(q, TASK_UNINTERRUPTIBLE, timeout); |
1da177e4 | 4974 | } |
1da177e4 LT |
4975 | EXPORT_SYMBOL(sleep_on_timeout); |
4976 | ||
b29739f9 IM |
4977 | #ifdef CONFIG_RT_MUTEXES |
4978 | ||
4979 | /* | |
4980 | * rt_mutex_setprio - set the current priority of a task | |
4981 | * @p: task | |
4982 | * @prio: prio value (kernel-internal form) | |
4983 | * | |
4984 | * This function changes the 'effective' priority of a task. It does | |
4985 | * not touch ->normal_prio like __setscheduler(). | |
4986 | * | |
4987 | * Used by the rt_mutex code to implement priority inheritance logic. | |
4988 | */ | |
36c8b586 | 4989 | void rt_mutex_setprio(struct task_struct *p, int prio) |
b29739f9 | 4990 | { |
83b699ed | 4991 | int oldprio, on_rq, running; |
70b97a7f | 4992 | struct rq *rq; |
83ab0aa0 | 4993 | const struct sched_class *prev_class; |
b29739f9 IM |
4994 | |
4995 | BUG_ON(prio < 0 || prio > MAX_PRIO); | |
4996 | ||
0122ec5b | 4997 | rq = __task_rq_lock(p); |
b29739f9 | 4998 | |
a8027073 | 4999 | trace_sched_pi_setprio(p, prio); |
d5f9f942 | 5000 | oldprio = p->prio; |
83ab0aa0 | 5001 | prev_class = p->sched_class; |
fd2f4419 | 5002 | on_rq = p->on_rq; |
051a1d1a | 5003 | running = task_current(rq, p); |
0e1f3483 | 5004 | if (on_rq) |
69be72c1 | 5005 | dequeue_task(rq, p, 0); |
0e1f3483 HS |
5006 | if (running) |
5007 | p->sched_class->put_prev_task(rq, p); | |
dd41f596 IM |
5008 | |
5009 | if (rt_prio(prio)) | |
5010 | p->sched_class = &rt_sched_class; | |
5011 | else | |
5012 | p->sched_class = &fair_sched_class; | |
5013 | ||
b29739f9 IM |
5014 | p->prio = prio; |
5015 | ||
0e1f3483 HS |
5016 | if (running) |
5017 | p->sched_class->set_curr_task(rq); | |
da7a735e | 5018 | if (on_rq) |
371fd7e7 | 5019 | enqueue_task(rq, p, oldprio < prio ? ENQUEUE_HEAD : 0); |
cb469845 | 5020 | |
da7a735e | 5021 | check_class_changed(rq, p, prev_class, oldprio); |
0122ec5b | 5022 | __task_rq_unlock(rq); |
b29739f9 IM |
5023 | } |
5024 | ||
5025 | #endif | |
5026 | ||
36c8b586 | 5027 | void set_user_nice(struct task_struct *p, long nice) |
1da177e4 | 5028 | { |
dd41f596 | 5029 | int old_prio, delta, on_rq; |
1da177e4 | 5030 | unsigned long flags; |
70b97a7f | 5031 | struct rq *rq; |
1da177e4 LT |
5032 | |
5033 | if (TASK_NICE(p) == nice || nice < -20 || nice > 19) | |
5034 | return; | |
5035 | /* | |
5036 | * We have to be careful, if called from sys_setpriority(), | |
5037 | * the task might be in the middle of scheduling on another CPU. | |
5038 | */ | |
5039 | rq = task_rq_lock(p, &flags); | |
5040 | /* | |
5041 | * The RT priorities are set via sched_setscheduler(), but we still | |
5042 | * allow the 'normal' nice value to be set - but as expected | |
5043 | * it wont have any effect on scheduling until the task is | |
dd41f596 | 5044 | * SCHED_FIFO/SCHED_RR: |
1da177e4 | 5045 | */ |
e05606d3 | 5046 | if (task_has_rt_policy(p)) { |
1da177e4 LT |
5047 | p->static_prio = NICE_TO_PRIO(nice); |
5048 | goto out_unlock; | |
5049 | } | |
fd2f4419 | 5050 | on_rq = p->on_rq; |
c09595f6 | 5051 | if (on_rq) |
69be72c1 | 5052 | dequeue_task(rq, p, 0); |
1da177e4 | 5053 | |
1da177e4 | 5054 | p->static_prio = NICE_TO_PRIO(nice); |
2dd73a4f | 5055 | set_load_weight(p); |
b29739f9 IM |
5056 | old_prio = p->prio; |
5057 | p->prio = effective_prio(p); | |
5058 | delta = p->prio - old_prio; | |
1da177e4 | 5059 | |
dd41f596 | 5060 | if (on_rq) { |
371fd7e7 | 5061 | enqueue_task(rq, p, 0); |
1da177e4 | 5062 | /* |
d5f9f942 AM |
5063 | * If the task increased its priority or is running and |
5064 | * lowered its priority, then reschedule its CPU: | |
1da177e4 | 5065 | */ |
d5f9f942 | 5066 | if (delta < 0 || (delta > 0 && task_running(rq, p))) |
1da177e4 LT |
5067 | resched_task(rq->curr); |
5068 | } | |
5069 | out_unlock: | |
0122ec5b | 5070 | task_rq_unlock(rq, p, &flags); |
1da177e4 | 5071 | } |
1da177e4 LT |
5072 | EXPORT_SYMBOL(set_user_nice); |
5073 | ||
e43379f1 MM |
5074 | /* |
5075 | * can_nice - check if a task can reduce its nice value | |
5076 | * @p: task | |
5077 | * @nice: nice value | |
5078 | */ | |
36c8b586 | 5079 | int can_nice(const struct task_struct *p, const int nice) |
e43379f1 | 5080 | { |
024f4747 MM |
5081 | /* convert nice value [19,-20] to rlimit style value [1,40] */ |
5082 | int nice_rlim = 20 - nice; | |
48f24c4d | 5083 | |
78d7d407 | 5084 | return (nice_rlim <= task_rlimit(p, RLIMIT_NICE) || |
e43379f1 MM |
5085 | capable(CAP_SYS_NICE)); |
5086 | } | |
5087 | ||
1da177e4 LT |
5088 | #ifdef __ARCH_WANT_SYS_NICE |
5089 | ||
5090 | /* | |
5091 | * sys_nice - change the priority of the current process. | |
5092 | * @increment: priority increment | |
5093 | * | |
5094 | * sys_setpriority is a more generic, but much slower function that | |
5095 | * does similar things. | |
5096 | */ | |
5add95d4 | 5097 | SYSCALL_DEFINE1(nice, int, increment) |
1da177e4 | 5098 | { |
48f24c4d | 5099 | long nice, retval; |
1da177e4 LT |
5100 | |
5101 | /* | |
5102 | * Setpriority might change our priority at the same moment. | |
5103 | * We don't have to worry. Conceptually one call occurs first | |
5104 | * and we have a single winner. | |
5105 | */ | |
e43379f1 MM |
5106 | if (increment < -40) |
5107 | increment = -40; | |
1da177e4 LT |
5108 | if (increment > 40) |
5109 | increment = 40; | |
5110 | ||
2b8f836f | 5111 | nice = TASK_NICE(current) + increment; |
1da177e4 LT |
5112 | if (nice < -20) |
5113 | nice = -20; | |
5114 | if (nice > 19) | |
5115 | nice = 19; | |
5116 | ||
e43379f1 MM |
5117 | if (increment < 0 && !can_nice(current, nice)) |
5118 | return -EPERM; | |
5119 | ||
1da177e4 LT |
5120 | retval = security_task_setnice(current, nice); |
5121 | if (retval) | |
5122 | return retval; | |
5123 | ||
5124 | set_user_nice(current, nice); | |
5125 | return 0; | |
5126 | } | |
5127 | ||
5128 | #endif | |
5129 | ||
5130 | /** | |
5131 | * task_prio - return the priority value of a given task. | |
5132 | * @p: the task in question. | |
5133 | * | |
5134 | * This is the priority value as seen by users in /proc. | |
5135 | * RT tasks are offset by -200. Normal tasks are centered | |
5136 | * around 0, value goes from -16 to +15. | |
5137 | */ | |
36c8b586 | 5138 | int task_prio(const struct task_struct *p) |
1da177e4 LT |
5139 | { |
5140 | return p->prio - MAX_RT_PRIO; | |
5141 | } | |
5142 | ||
5143 | /** | |
5144 | * task_nice - return the nice value of a given task. | |
5145 | * @p: the task in question. | |
5146 | */ | |
36c8b586 | 5147 | int task_nice(const struct task_struct *p) |
1da177e4 LT |
5148 | { |
5149 | return TASK_NICE(p); | |
5150 | } | |
150d8bed | 5151 | EXPORT_SYMBOL(task_nice); |
1da177e4 LT |
5152 | |
5153 | /** | |
5154 | * idle_cpu - is a given cpu idle currently? | |
5155 | * @cpu: the processor in question. | |
5156 | */ | |
5157 | int idle_cpu(int cpu) | |
5158 | { | |
908a3283 TG |
5159 | struct rq *rq = cpu_rq(cpu); |
5160 | ||
5161 | if (rq->curr != rq->idle) | |
5162 | return 0; | |
5163 | ||
5164 | if (rq->nr_running) | |
5165 | return 0; | |
5166 | ||
5167 | #ifdef CONFIG_SMP | |
5168 | if (!llist_empty(&rq->wake_list)) | |
5169 | return 0; | |
5170 | #endif | |
5171 | ||
5172 | return 1; | |
1da177e4 LT |
5173 | } |
5174 | ||
1da177e4 LT |
5175 | /** |
5176 | * idle_task - return the idle task for a given cpu. | |
5177 | * @cpu: the processor in question. | |
5178 | */ | |
36c8b586 | 5179 | struct task_struct *idle_task(int cpu) |
1da177e4 LT |
5180 | { |
5181 | return cpu_rq(cpu)->idle; | |
5182 | } | |
5183 | ||
5184 | /** | |
5185 | * find_process_by_pid - find a process with a matching PID value. | |
5186 | * @pid: the pid in question. | |
5187 | */ | |
a9957449 | 5188 | static struct task_struct *find_process_by_pid(pid_t pid) |
1da177e4 | 5189 | { |
228ebcbe | 5190 | return pid ? find_task_by_vpid(pid) : current; |
1da177e4 LT |
5191 | } |
5192 | ||
5193 | /* Actually do priority change: must hold rq lock. */ | |
dd41f596 IM |
5194 | static void |
5195 | __setscheduler(struct rq *rq, struct task_struct *p, int policy, int prio) | |
1da177e4 | 5196 | { |
1da177e4 LT |
5197 | p->policy = policy; |
5198 | p->rt_priority = prio; | |
b29739f9 IM |
5199 | p->normal_prio = normal_prio(p); |
5200 | /* we are holding p->pi_lock already */ | |
5201 | p->prio = rt_mutex_getprio(p); | |
ffd44db5 PZ |
5202 | if (rt_prio(p->prio)) |
5203 | p->sched_class = &rt_sched_class; | |
5204 | else | |
5205 | p->sched_class = &fair_sched_class; | |
2dd73a4f | 5206 | set_load_weight(p); |
1da177e4 LT |
5207 | } |
5208 | ||
c69e8d9c DH |
5209 | /* |
5210 | * check the target process has a UID that matches the current process's | |
5211 | */ | |
5212 | static bool check_same_owner(struct task_struct *p) | |
5213 | { | |
5214 | const struct cred *cred = current_cred(), *pcred; | |
5215 | bool match; | |
5216 | ||
5217 | rcu_read_lock(); | |
5218 | pcred = __task_cred(p); | |
b0e77598 SH |
5219 | if (cred->user->user_ns == pcred->user->user_ns) |
5220 | match = (cred->euid == pcred->euid || | |
5221 | cred->euid == pcred->uid); | |
5222 | else | |
5223 | match = false; | |
c69e8d9c DH |
5224 | rcu_read_unlock(); |
5225 | return match; | |
5226 | } | |
5227 | ||
961ccddd | 5228 | static int __sched_setscheduler(struct task_struct *p, int policy, |
fe7de49f | 5229 | const struct sched_param *param, bool user) |
1da177e4 | 5230 | { |
83b699ed | 5231 | int retval, oldprio, oldpolicy = -1, on_rq, running; |
1da177e4 | 5232 | unsigned long flags; |
83ab0aa0 | 5233 | const struct sched_class *prev_class; |
70b97a7f | 5234 | struct rq *rq; |
ca94c442 | 5235 | int reset_on_fork; |
1da177e4 | 5236 | |
66e5393a SR |
5237 | /* may grab non-irq protected spin_locks */ |
5238 | BUG_ON(in_interrupt()); | |
1da177e4 LT |
5239 | recheck: |
5240 | /* double check policy once rq lock held */ | |
ca94c442 LP |
5241 | if (policy < 0) { |
5242 | reset_on_fork = p->sched_reset_on_fork; | |
1da177e4 | 5243 | policy = oldpolicy = p->policy; |
ca94c442 LP |
5244 | } else { |
5245 | reset_on_fork = !!(policy & SCHED_RESET_ON_FORK); | |
5246 | policy &= ~SCHED_RESET_ON_FORK; | |
5247 | ||
5248 | if (policy != SCHED_FIFO && policy != SCHED_RR && | |
5249 | policy != SCHED_NORMAL && policy != SCHED_BATCH && | |
5250 | policy != SCHED_IDLE) | |
5251 | return -EINVAL; | |
5252 | } | |
5253 | ||
1da177e4 LT |
5254 | /* |
5255 | * Valid priorities for SCHED_FIFO and SCHED_RR are | |
dd41f596 IM |
5256 | * 1..MAX_USER_RT_PRIO-1, valid priority for SCHED_NORMAL, |
5257 | * SCHED_BATCH and SCHED_IDLE is 0. | |
1da177e4 LT |
5258 | */ |
5259 | if (param->sched_priority < 0 || | |
95cdf3b7 | 5260 | (p->mm && param->sched_priority > MAX_USER_RT_PRIO-1) || |
d46523ea | 5261 | (!p->mm && param->sched_priority > MAX_RT_PRIO-1)) |
1da177e4 | 5262 | return -EINVAL; |
e05606d3 | 5263 | if (rt_policy(policy) != (param->sched_priority != 0)) |
1da177e4 LT |
5264 | return -EINVAL; |
5265 | ||
37e4ab3f OC |
5266 | /* |
5267 | * Allow unprivileged RT tasks to decrease priority: | |
5268 | */ | |
961ccddd | 5269 | if (user && !capable(CAP_SYS_NICE)) { |
e05606d3 | 5270 | if (rt_policy(policy)) { |
a44702e8 ON |
5271 | unsigned long rlim_rtprio = |
5272 | task_rlimit(p, RLIMIT_RTPRIO); | |
8dc3e909 ON |
5273 | |
5274 | /* can't set/change the rt policy */ | |
5275 | if (policy != p->policy && !rlim_rtprio) | |
5276 | return -EPERM; | |
5277 | ||
5278 | /* can't increase priority */ | |
5279 | if (param->sched_priority > p->rt_priority && | |
5280 | param->sched_priority > rlim_rtprio) | |
5281 | return -EPERM; | |
5282 | } | |
c02aa73b | 5283 | |
dd41f596 | 5284 | /* |
c02aa73b DH |
5285 | * Treat SCHED_IDLE as nice 20. Only allow a switch to |
5286 | * SCHED_NORMAL if the RLIMIT_NICE would normally permit it. | |
dd41f596 | 5287 | */ |
c02aa73b DH |
5288 | if (p->policy == SCHED_IDLE && policy != SCHED_IDLE) { |
5289 | if (!can_nice(p, TASK_NICE(p))) | |
5290 | return -EPERM; | |
5291 | } | |
5fe1d75f | 5292 | |
37e4ab3f | 5293 | /* can't change other user's priorities */ |
c69e8d9c | 5294 | if (!check_same_owner(p)) |
37e4ab3f | 5295 | return -EPERM; |
ca94c442 LP |
5296 | |
5297 | /* Normal users shall not reset the sched_reset_on_fork flag */ | |
5298 | if (p->sched_reset_on_fork && !reset_on_fork) | |
5299 | return -EPERM; | |
37e4ab3f | 5300 | } |
1da177e4 | 5301 | |
725aad24 | 5302 | if (user) { |
b0ae1981 | 5303 | retval = security_task_setscheduler(p); |
725aad24 JF |
5304 | if (retval) |
5305 | return retval; | |
5306 | } | |
5307 | ||
b29739f9 IM |
5308 | /* |
5309 | * make sure no PI-waiters arrive (or leave) while we are | |
5310 | * changing the priority of the task: | |
0122ec5b | 5311 | * |
25985edc | 5312 | * To be able to change p->policy safely, the appropriate |
1da177e4 LT |
5313 | * runqueue lock must be held. |
5314 | */ | |
0122ec5b | 5315 | rq = task_rq_lock(p, &flags); |
dc61b1d6 | 5316 | |
34f971f6 PZ |
5317 | /* |
5318 | * Changing the policy of the stop threads its a very bad idea | |
5319 | */ | |
5320 | if (p == rq->stop) { | |
0122ec5b | 5321 | task_rq_unlock(rq, p, &flags); |
34f971f6 PZ |
5322 | return -EINVAL; |
5323 | } | |
5324 | ||
a51e9198 DF |
5325 | /* |
5326 | * If not changing anything there's no need to proceed further: | |
5327 | */ | |
5328 | if (unlikely(policy == p->policy && (!rt_policy(policy) || | |
5329 | param->sched_priority == p->rt_priority))) { | |
5330 | ||
5331 | __task_rq_unlock(rq); | |
5332 | raw_spin_unlock_irqrestore(&p->pi_lock, flags); | |
5333 | return 0; | |
5334 | } | |
5335 | ||
dc61b1d6 PZ |
5336 | #ifdef CONFIG_RT_GROUP_SCHED |
5337 | if (user) { | |
5338 | /* | |
5339 | * Do not allow realtime tasks into groups that have no runtime | |
5340 | * assigned. | |
5341 | */ | |
5342 | if (rt_bandwidth_enabled() && rt_policy(policy) && | |
f4493771 MG |
5343 | task_group(p)->rt_bandwidth.rt_runtime == 0 && |
5344 | !task_group_is_autogroup(task_group(p))) { | |
0122ec5b | 5345 | task_rq_unlock(rq, p, &flags); |
dc61b1d6 PZ |
5346 | return -EPERM; |
5347 | } | |
5348 | } | |
5349 | #endif | |
5350 | ||
1da177e4 LT |
5351 | /* recheck policy now with rq lock held */ |
5352 | if (unlikely(oldpolicy != -1 && oldpolicy != p->policy)) { | |
5353 | policy = oldpolicy = -1; | |
0122ec5b | 5354 | task_rq_unlock(rq, p, &flags); |
1da177e4 LT |
5355 | goto recheck; |
5356 | } | |
fd2f4419 | 5357 | on_rq = p->on_rq; |
051a1d1a | 5358 | running = task_current(rq, p); |
0e1f3483 | 5359 | if (on_rq) |
2e1cb74a | 5360 | deactivate_task(rq, p, 0); |
0e1f3483 HS |
5361 | if (running) |
5362 | p->sched_class->put_prev_task(rq, p); | |
f6b53205 | 5363 | |
ca94c442 LP |
5364 | p->sched_reset_on_fork = reset_on_fork; |
5365 | ||
1da177e4 | 5366 | oldprio = p->prio; |
83ab0aa0 | 5367 | prev_class = p->sched_class; |
dd41f596 | 5368 | __setscheduler(rq, p, policy, param->sched_priority); |
f6b53205 | 5369 | |
0e1f3483 HS |
5370 | if (running) |
5371 | p->sched_class->set_curr_task(rq); | |
da7a735e | 5372 | if (on_rq) |
dd41f596 | 5373 | activate_task(rq, p, 0); |
cb469845 | 5374 | |
da7a735e | 5375 | check_class_changed(rq, p, prev_class, oldprio); |
0122ec5b | 5376 | task_rq_unlock(rq, p, &flags); |
b29739f9 | 5377 | |
95e02ca9 TG |
5378 | rt_mutex_adjust_pi(p); |
5379 | ||
1da177e4 LT |
5380 | return 0; |
5381 | } | |
961ccddd RR |
5382 | |
5383 | /** | |
5384 | * sched_setscheduler - change the scheduling policy and/or RT priority of a thread. | |
5385 | * @p: the task in question. | |
5386 | * @policy: new policy. | |
5387 | * @param: structure containing the new RT priority. | |
5388 | * | |
5389 | * NOTE that the task may be already dead. | |
5390 | */ | |
5391 | int sched_setscheduler(struct task_struct *p, int policy, | |
fe7de49f | 5392 | const struct sched_param *param) |
961ccddd RR |
5393 | { |
5394 | return __sched_setscheduler(p, policy, param, true); | |
5395 | } | |
1da177e4 LT |
5396 | EXPORT_SYMBOL_GPL(sched_setscheduler); |
5397 | ||
961ccddd RR |
5398 | /** |
5399 | * sched_setscheduler_nocheck - change the scheduling policy and/or RT priority of a thread from kernelspace. | |
5400 | * @p: the task in question. | |
5401 | * @policy: new policy. | |
5402 | * @param: structure containing the new RT priority. | |
5403 | * | |
5404 | * Just like sched_setscheduler, only don't bother checking if the | |
5405 | * current context has permission. For example, this is needed in | |
5406 | * stop_machine(): we create temporary high priority worker threads, | |
5407 | * but our caller might not have that capability. | |
5408 | */ | |
5409 | int sched_setscheduler_nocheck(struct task_struct *p, int policy, | |
fe7de49f | 5410 | const struct sched_param *param) |
961ccddd RR |
5411 | { |
5412 | return __sched_setscheduler(p, policy, param, false); | |
5413 | } | |
5414 | ||
95cdf3b7 IM |
5415 | static int |
5416 | do_sched_setscheduler(pid_t pid, int policy, struct sched_param __user *param) | |
1da177e4 | 5417 | { |
1da177e4 LT |
5418 | struct sched_param lparam; |
5419 | struct task_struct *p; | |
36c8b586 | 5420 | int retval; |
1da177e4 LT |
5421 | |
5422 | if (!param || pid < 0) | |
5423 | return -EINVAL; | |
5424 | if (copy_from_user(&lparam, param, sizeof(struct sched_param))) | |
5425 | return -EFAULT; | |
5fe1d75f ON |
5426 | |
5427 | rcu_read_lock(); | |
5428 | retval = -ESRCH; | |
1da177e4 | 5429 | p = find_process_by_pid(pid); |
5fe1d75f ON |
5430 | if (p != NULL) |
5431 | retval = sched_setscheduler(p, policy, &lparam); | |
5432 | rcu_read_unlock(); | |
36c8b586 | 5433 | |
1da177e4 LT |
5434 | return retval; |
5435 | } | |
5436 | ||
5437 | /** | |
5438 | * sys_sched_setscheduler - set/change the scheduler policy and RT priority | |
5439 | * @pid: the pid in question. | |
5440 | * @policy: new policy. | |
5441 | * @param: structure containing the new RT priority. | |
5442 | */ | |
5add95d4 HC |
5443 | SYSCALL_DEFINE3(sched_setscheduler, pid_t, pid, int, policy, |
5444 | struct sched_param __user *, param) | |
1da177e4 | 5445 | { |
c21761f1 JB |
5446 | /* negative values for policy are not valid */ |
5447 | if (policy < 0) | |
5448 | return -EINVAL; | |
5449 | ||
1da177e4 LT |
5450 | return do_sched_setscheduler(pid, policy, param); |
5451 | } | |
5452 | ||
5453 | /** | |
5454 | * sys_sched_setparam - set/change the RT priority of a thread | |
5455 | * @pid: the pid in question. | |
5456 | * @param: structure containing the new RT priority. | |
5457 | */ | |
5add95d4 | 5458 | SYSCALL_DEFINE2(sched_setparam, pid_t, pid, struct sched_param __user *, param) |
1da177e4 LT |
5459 | { |
5460 | return do_sched_setscheduler(pid, -1, param); | |
5461 | } | |
5462 | ||
5463 | /** | |
5464 | * sys_sched_getscheduler - get the policy (scheduling class) of a thread | |
5465 | * @pid: the pid in question. | |
5466 | */ | |
5add95d4 | 5467 | SYSCALL_DEFINE1(sched_getscheduler, pid_t, pid) |
1da177e4 | 5468 | { |
36c8b586 | 5469 | struct task_struct *p; |
3a5c359a | 5470 | int retval; |
1da177e4 LT |
5471 | |
5472 | if (pid < 0) | |
3a5c359a | 5473 | return -EINVAL; |
1da177e4 LT |
5474 | |
5475 | retval = -ESRCH; | |
5fe85be0 | 5476 | rcu_read_lock(); |
1da177e4 LT |
5477 | p = find_process_by_pid(pid); |
5478 | if (p) { | |
5479 | retval = security_task_getscheduler(p); | |
5480 | if (!retval) | |
ca94c442 LP |
5481 | retval = p->policy |
5482 | | (p->sched_reset_on_fork ? SCHED_RESET_ON_FORK : 0); | |
1da177e4 | 5483 | } |
5fe85be0 | 5484 | rcu_read_unlock(); |
1da177e4 LT |
5485 | return retval; |
5486 | } | |
5487 | ||
5488 | /** | |
ca94c442 | 5489 | * sys_sched_getparam - get the RT priority of a thread |
1da177e4 LT |
5490 | * @pid: the pid in question. |
5491 | * @param: structure containing the RT priority. | |
5492 | */ | |
5add95d4 | 5493 | SYSCALL_DEFINE2(sched_getparam, pid_t, pid, struct sched_param __user *, param) |
1da177e4 LT |
5494 | { |
5495 | struct sched_param lp; | |
36c8b586 | 5496 | struct task_struct *p; |
3a5c359a | 5497 | int retval; |
1da177e4 LT |
5498 | |
5499 | if (!param || pid < 0) | |
3a5c359a | 5500 | return -EINVAL; |
1da177e4 | 5501 | |
5fe85be0 | 5502 | rcu_read_lock(); |
1da177e4 LT |
5503 | p = find_process_by_pid(pid); |
5504 | retval = -ESRCH; | |
5505 | if (!p) | |
5506 | goto out_unlock; | |
5507 | ||
5508 | retval = security_task_getscheduler(p); | |
5509 | if (retval) | |
5510 | goto out_unlock; | |
5511 | ||
5512 | lp.sched_priority = p->rt_priority; | |
5fe85be0 | 5513 | rcu_read_unlock(); |
1da177e4 LT |
5514 | |
5515 | /* | |
5516 | * This one might sleep, we cannot do it with a spinlock held ... | |
5517 | */ | |
5518 | retval = copy_to_user(param, &lp, sizeof(*param)) ? -EFAULT : 0; | |
5519 | ||
1da177e4 LT |
5520 | return retval; |
5521 | ||
5522 | out_unlock: | |
5fe85be0 | 5523 | rcu_read_unlock(); |
1da177e4 LT |
5524 | return retval; |
5525 | } | |
5526 | ||
96f874e2 | 5527 | long sched_setaffinity(pid_t pid, const struct cpumask *in_mask) |
1da177e4 | 5528 | { |
5a16f3d3 | 5529 | cpumask_var_t cpus_allowed, new_mask; |
36c8b586 IM |
5530 | struct task_struct *p; |
5531 | int retval; | |
1da177e4 | 5532 | |
95402b38 | 5533 | get_online_cpus(); |
23f5d142 | 5534 | rcu_read_lock(); |
1da177e4 LT |
5535 | |
5536 | p = find_process_by_pid(pid); | |
5537 | if (!p) { | |
23f5d142 | 5538 | rcu_read_unlock(); |
95402b38 | 5539 | put_online_cpus(); |
1da177e4 LT |
5540 | return -ESRCH; |
5541 | } | |
5542 | ||
23f5d142 | 5543 | /* Prevent p going away */ |
1da177e4 | 5544 | get_task_struct(p); |
23f5d142 | 5545 | rcu_read_unlock(); |
1da177e4 | 5546 | |
5a16f3d3 RR |
5547 | if (!alloc_cpumask_var(&cpus_allowed, GFP_KERNEL)) { |
5548 | retval = -ENOMEM; | |
5549 | goto out_put_task; | |
5550 | } | |
5551 | if (!alloc_cpumask_var(&new_mask, GFP_KERNEL)) { | |
5552 | retval = -ENOMEM; | |
5553 | goto out_free_cpus_allowed; | |
5554 | } | |
1da177e4 | 5555 | retval = -EPERM; |
b0e77598 | 5556 | if (!check_same_owner(p) && !task_ns_capable(p, CAP_SYS_NICE)) |
1da177e4 LT |
5557 | goto out_unlock; |
5558 | ||
b0ae1981 | 5559 | retval = security_task_setscheduler(p); |
e7834f8f DQ |
5560 | if (retval) |
5561 | goto out_unlock; | |
5562 | ||
5a16f3d3 RR |
5563 | cpuset_cpus_allowed(p, cpus_allowed); |
5564 | cpumask_and(new_mask, in_mask, cpus_allowed); | |
49246274 | 5565 | again: |
5a16f3d3 | 5566 | retval = set_cpus_allowed_ptr(p, new_mask); |
1da177e4 | 5567 | |
8707d8b8 | 5568 | if (!retval) { |
5a16f3d3 RR |
5569 | cpuset_cpus_allowed(p, cpus_allowed); |
5570 | if (!cpumask_subset(new_mask, cpus_allowed)) { | |
8707d8b8 PM |
5571 | /* |
5572 | * We must have raced with a concurrent cpuset | |
5573 | * update. Just reset the cpus_allowed to the | |
5574 | * cpuset's cpus_allowed | |
5575 | */ | |
5a16f3d3 | 5576 | cpumask_copy(new_mask, cpus_allowed); |
8707d8b8 PM |
5577 | goto again; |
5578 | } | |
5579 | } | |
1da177e4 | 5580 | out_unlock: |
5a16f3d3 RR |
5581 | free_cpumask_var(new_mask); |
5582 | out_free_cpus_allowed: | |
5583 | free_cpumask_var(cpus_allowed); | |
5584 | out_put_task: | |
1da177e4 | 5585 | put_task_struct(p); |
95402b38 | 5586 | put_online_cpus(); |
1da177e4 LT |
5587 | return retval; |
5588 | } | |
5589 | ||
5590 | static int get_user_cpu_mask(unsigned long __user *user_mask_ptr, unsigned len, | |
96f874e2 | 5591 | struct cpumask *new_mask) |
1da177e4 | 5592 | { |
96f874e2 RR |
5593 | if (len < cpumask_size()) |
5594 | cpumask_clear(new_mask); | |
5595 | else if (len > cpumask_size()) | |
5596 | len = cpumask_size(); | |
5597 | ||
1da177e4 LT |
5598 | return copy_from_user(new_mask, user_mask_ptr, len) ? -EFAULT : 0; |
5599 | } | |
5600 | ||
5601 | /** | |
5602 | * sys_sched_setaffinity - set the cpu affinity of a process | |
5603 | * @pid: pid of the process | |
5604 | * @len: length in bytes of the bitmask pointed to by user_mask_ptr | |
5605 | * @user_mask_ptr: user-space pointer to the new cpu mask | |
5606 | */ | |
5add95d4 HC |
5607 | SYSCALL_DEFINE3(sched_setaffinity, pid_t, pid, unsigned int, len, |
5608 | unsigned long __user *, user_mask_ptr) | |
1da177e4 | 5609 | { |
5a16f3d3 | 5610 | cpumask_var_t new_mask; |
1da177e4 LT |
5611 | int retval; |
5612 | ||
5a16f3d3 RR |
5613 | if (!alloc_cpumask_var(&new_mask, GFP_KERNEL)) |
5614 | return -ENOMEM; | |
1da177e4 | 5615 | |
5a16f3d3 RR |
5616 | retval = get_user_cpu_mask(user_mask_ptr, len, new_mask); |
5617 | if (retval == 0) | |
5618 | retval = sched_setaffinity(pid, new_mask); | |
5619 | free_cpumask_var(new_mask); | |
5620 | return retval; | |
1da177e4 LT |
5621 | } |
5622 | ||
96f874e2 | 5623 | long sched_getaffinity(pid_t pid, struct cpumask *mask) |
1da177e4 | 5624 | { |
36c8b586 | 5625 | struct task_struct *p; |
31605683 | 5626 | unsigned long flags; |
1da177e4 | 5627 | int retval; |
1da177e4 | 5628 | |
95402b38 | 5629 | get_online_cpus(); |
23f5d142 | 5630 | rcu_read_lock(); |
1da177e4 LT |
5631 | |
5632 | retval = -ESRCH; | |
5633 | p = find_process_by_pid(pid); | |
5634 | if (!p) | |
5635 | goto out_unlock; | |
5636 | ||
e7834f8f DQ |
5637 | retval = security_task_getscheduler(p); |
5638 | if (retval) | |
5639 | goto out_unlock; | |
5640 | ||
013fdb80 | 5641 | raw_spin_lock_irqsave(&p->pi_lock, flags); |
96f874e2 | 5642 | cpumask_and(mask, &p->cpus_allowed, cpu_online_mask); |
013fdb80 | 5643 | raw_spin_unlock_irqrestore(&p->pi_lock, flags); |
1da177e4 LT |
5644 | |
5645 | out_unlock: | |
23f5d142 | 5646 | rcu_read_unlock(); |
95402b38 | 5647 | put_online_cpus(); |
1da177e4 | 5648 | |
9531b62f | 5649 | return retval; |
1da177e4 LT |
5650 | } |
5651 | ||
5652 | /** | |
5653 | * sys_sched_getaffinity - get the cpu affinity of a process | |
5654 | * @pid: pid of the process | |
5655 | * @len: length in bytes of the bitmask pointed to by user_mask_ptr | |
5656 | * @user_mask_ptr: user-space pointer to hold the current cpu mask | |
5657 | */ | |
5add95d4 HC |
5658 | SYSCALL_DEFINE3(sched_getaffinity, pid_t, pid, unsigned int, len, |
5659 | unsigned long __user *, user_mask_ptr) | |
1da177e4 LT |
5660 | { |
5661 | int ret; | |
f17c8607 | 5662 | cpumask_var_t mask; |
1da177e4 | 5663 | |
84fba5ec | 5664 | if ((len * BITS_PER_BYTE) < nr_cpu_ids) |
cd3d8031 KM |
5665 | return -EINVAL; |
5666 | if (len & (sizeof(unsigned long)-1)) | |
1da177e4 LT |
5667 | return -EINVAL; |
5668 | ||
f17c8607 RR |
5669 | if (!alloc_cpumask_var(&mask, GFP_KERNEL)) |
5670 | return -ENOMEM; | |
1da177e4 | 5671 | |
f17c8607 RR |
5672 | ret = sched_getaffinity(pid, mask); |
5673 | if (ret == 0) { | |
8bc037fb | 5674 | size_t retlen = min_t(size_t, len, cpumask_size()); |
cd3d8031 KM |
5675 | |
5676 | if (copy_to_user(user_mask_ptr, mask, retlen)) | |
f17c8607 RR |
5677 | ret = -EFAULT; |
5678 | else | |
cd3d8031 | 5679 | ret = retlen; |
f17c8607 RR |
5680 | } |
5681 | free_cpumask_var(mask); | |
1da177e4 | 5682 | |
f17c8607 | 5683 | return ret; |
1da177e4 LT |
5684 | } |
5685 | ||
5686 | /** | |
5687 | * sys_sched_yield - yield the current processor to other threads. | |
5688 | * | |
dd41f596 IM |
5689 | * This function yields the current CPU to other tasks. If there are no |
5690 | * other threads running on this CPU then this function will return. | |
1da177e4 | 5691 | */ |
5add95d4 | 5692 | SYSCALL_DEFINE0(sched_yield) |
1da177e4 | 5693 | { |
70b97a7f | 5694 | struct rq *rq = this_rq_lock(); |
1da177e4 | 5695 | |
2d72376b | 5696 | schedstat_inc(rq, yld_count); |
4530d7ab | 5697 | current->sched_class->yield_task(rq); |
1da177e4 LT |
5698 | |
5699 | /* | |
5700 | * Since we are going to call schedule() anyway, there's | |
5701 | * no need to preempt or enable interrupts: | |
5702 | */ | |
5703 | __release(rq->lock); | |
8a25d5de | 5704 | spin_release(&rq->lock.dep_map, 1, _THIS_IP_); |
9828ea9d | 5705 | do_raw_spin_unlock(&rq->lock); |
1da177e4 LT |
5706 | preempt_enable_no_resched(); |
5707 | ||
5708 | schedule(); | |
5709 | ||
5710 | return 0; | |
5711 | } | |
5712 | ||
d86ee480 PZ |
5713 | static inline int should_resched(void) |
5714 | { | |
5715 | return need_resched() && !(preempt_count() & PREEMPT_ACTIVE); | |
5716 | } | |
5717 | ||
e7b38404 | 5718 | static void __cond_resched(void) |
1da177e4 | 5719 | { |
e7aaaa69 | 5720 | add_preempt_count(PREEMPT_ACTIVE); |
c259e01a | 5721 | __schedule(); |
e7aaaa69 | 5722 | sub_preempt_count(PREEMPT_ACTIVE); |
1da177e4 LT |
5723 | } |
5724 | ||
02b67cc3 | 5725 | int __sched _cond_resched(void) |
1da177e4 | 5726 | { |
d86ee480 | 5727 | if (should_resched()) { |
1da177e4 LT |
5728 | __cond_resched(); |
5729 | return 1; | |
5730 | } | |
5731 | return 0; | |
5732 | } | |
02b67cc3 | 5733 | EXPORT_SYMBOL(_cond_resched); |
1da177e4 LT |
5734 | |
5735 | /* | |
613afbf8 | 5736 | * __cond_resched_lock() - if a reschedule is pending, drop the given lock, |
1da177e4 LT |
5737 | * call schedule, and on return reacquire the lock. |
5738 | * | |
41a2d6cf | 5739 | * This works OK both with and without CONFIG_PREEMPT. We do strange low-level |
1da177e4 LT |
5740 | * operations here to prevent schedule() from being called twice (once via |
5741 | * spin_unlock(), once by hand). | |
5742 | */ | |
613afbf8 | 5743 | int __cond_resched_lock(spinlock_t *lock) |
1da177e4 | 5744 | { |
d86ee480 | 5745 | int resched = should_resched(); |
6df3cecb JK |
5746 | int ret = 0; |
5747 | ||
f607c668 PZ |
5748 | lockdep_assert_held(lock); |
5749 | ||
95c354fe | 5750 | if (spin_needbreak(lock) || resched) { |
1da177e4 | 5751 | spin_unlock(lock); |
d86ee480 | 5752 | if (resched) |
95c354fe NP |
5753 | __cond_resched(); |
5754 | else | |
5755 | cpu_relax(); | |
6df3cecb | 5756 | ret = 1; |
1da177e4 | 5757 | spin_lock(lock); |
1da177e4 | 5758 | } |
6df3cecb | 5759 | return ret; |
1da177e4 | 5760 | } |
613afbf8 | 5761 | EXPORT_SYMBOL(__cond_resched_lock); |
1da177e4 | 5762 | |
613afbf8 | 5763 | int __sched __cond_resched_softirq(void) |
1da177e4 LT |
5764 | { |
5765 | BUG_ON(!in_softirq()); | |
5766 | ||
d86ee480 | 5767 | if (should_resched()) { |
98d82567 | 5768 | local_bh_enable(); |
1da177e4 LT |
5769 | __cond_resched(); |
5770 | local_bh_disable(); | |
5771 | return 1; | |
5772 | } | |
5773 | return 0; | |
5774 | } | |
613afbf8 | 5775 | EXPORT_SYMBOL(__cond_resched_softirq); |
1da177e4 | 5776 | |
1da177e4 LT |
5777 | /** |
5778 | * yield - yield the current processor to other threads. | |
5779 | * | |
72fd4a35 | 5780 | * This is a shortcut for kernel-space yielding - it marks the |
1da177e4 LT |
5781 | * thread runnable and calls sys_sched_yield(). |
5782 | */ | |
5783 | void __sched yield(void) | |
5784 | { | |
5785 | set_current_state(TASK_RUNNING); | |
5786 | sys_sched_yield(); | |
5787 | } | |
1da177e4 LT |
5788 | EXPORT_SYMBOL(yield); |
5789 | ||
d95f4122 MG |
5790 | /** |
5791 | * yield_to - yield the current processor to another thread in | |
5792 | * your thread group, or accelerate that thread toward the | |
5793 | * processor it's on. | |
16addf95 RD |
5794 | * @p: target task |
5795 | * @preempt: whether task preemption is allowed or not | |
d95f4122 MG |
5796 | * |
5797 | * It's the caller's job to ensure that the target task struct | |
5798 | * can't go away on us before we can do any checks. | |
5799 | * | |
5800 | * Returns true if we indeed boosted the target task. | |
5801 | */ | |
5802 | bool __sched yield_to(struct task_struct *p, bool preempt) | |
5803 | { | |
5804 | struct task_struct *curr = current; | |
5805 | struct rq *rq, *p_rq; | |
5806 | unsigned long flags; | |
5807 | bool yielded = 0; | |
5808 | ||
5809 | local_irq_save(flags); | |
5810 | rq = this_rq(); | |
5811 | ||
5812 | again: | |
5813 | p_rq = task_rq(p); | |
5814 | double_rq_lock(rq, p_rq); | |
5815 | while (task_rq(p) != p_rq) { | |
5816 | double_rq_unlock(rq, p_rq); | |
5817 | goto again; | |
5818 | } | |
5819 | ||
5820 | if (!curr->sched_class->yield_to_task) | |
5821 | goto out; | |
5822 | ||
5823 | if (curr->sched_class != p->sched_class) | |
5824 | goto out; | |
5825 | ||
5826 | if (task_running(p_rq, p) || p->state) | |
5827 | goto out; | |
5828 | ||
5829 | yielded = curr->sched_class->yield_to_task(rq, p, preempt); | |
6d1cafd8 | 5830 | if (yielded) { |
d95f4122 | 5831 | schedstat_inc(rq, yld_count); |
6d1cafd8 VP |
5832 | /* |
5833 | * Make p's CPU reschedule; pick_next_entity takes care of | |
5834 | * fairness. | |
5835 | */ | |
5836 | if (preempt && rq != p_rq) | |
5837 | resched_task(p_rq->curr); | |
5838 | } | |
d95f4122 MG |
5839 | |
5840 | out: | |
5841 | double_rq_unlock(rq, p_rq); | |
5842 | local_irq_restore(flags); | |
5843 | ||
5844 | if (yielded) | |
5845 | schedule(); | |
5846 | ||
5847 | return yielded; | |
5848 | } | |
5849 | EXPORT_SYMBOL_GPL(yield_to); | |
5850 | ||
1da177e4 | 5851 | /* |
41a2d6cf | 5852 | * This task is about to go to sleep on IO. Increment rq->nr_iowait so |
1da177e4 | 5853 | * that process accounting knows that this is a task in IO wait state. |
1da177e4 LT |
5854 | */ |
5855 | void __sched io_schedule(void) | |
5856 | { | |
54d35f29 | 5857 | struct rq *rq = raw_rq(); |
1da177e4 | 5858 | |
0ff92245 | 5859 | delayacct_blkio_start(); |
1da177e4 | 5860 | atomic_inc(&rq->nr_iowait); |
73c10101 | 5861 | blk_flush_plug(current); |
8f0dfc34 | 5862 | current->in_iowait = 1; |
1da177e4 | 5863 | schedule(); |
8f0dfc34 | 5864 | current->in_iowait = 0; |
1da177e4 | 5865 | atomic_dec(&rq->nr_iowait); |
0ff92245 | 5866 | delayacct_blkio_end(); |
1da177e4 | 5867 | } |
1da177e4 LT |
5868 | EXPORT_SYMBOL(io_schedule); |
5869 | ||
5870 | long __sched io_schedule_timeout(long timeout) | |
5871 | { | |
54d35f29 | 5872 | struct rq *rq = raw_rq(); |
1da177e4 LT |
5873 | long ret; |
5874 | ||
0ff92245 | 5875 | delayacct_blkio_start(); |
1da177e4 | 5876 | atomic_inc(&rq->nr_iowait); |
73c10101 | 5877 | blk_flush_plug(current); |
8f0dfc34 | 5878 | current->in_iowait = 1; |
1da177e4 | 5879 | ret = schedule_timeout(timeout); |
8f0dfc34 | 5880 | current->in_iowait = 0; |
1da177e4 | 5881 | atomic_dec(&rq->nr_iowait); |
0ff92245 | 5882 | delayacct_blkio_end(); |
1da177e4 LT |
5883 | return ret; |
5884 | } | |
5885 | ||
5886 | /** | |
5887 | * sys_sched_get_priority_max - return maximum RT priority. | |
5888 | * @policy: scheduling class. | |
5889 | * | |
5890 | * this syscall returns the maximum rt_priority that can be used | |
5891 | * by a given scheduling class. | |
5892 | */ | |
5add95d4 | 5893 | SYSCALL_DEFINE1(sched_get_priority_max, int, policy) |
1da177e4 LT |
5894 | { |
5895 | int ret = -EINVAL; | |
5896 | ||
5897 | switch (policy) { | |
5898 | case SCHED_FIFO: | |
5899 | case SCHED_RR: | |
5900 | ret = MAX_USER_RT_PRIO-1; | |
5901 | break; | |
5902 | case SCHED_NORMAL: | |
b0a9499c | 5903 | case SCHED_BATCH: |
dd41f596 | 5904 | case SCHED_IDLE: |
1da177e4 LT |
5905 | ret = 0; |
5906 | break; | |
5907 | } | |
5908 | return ret; | |
5909 | } | |
5910 | ||
5911 | /** | |
5912 | * sys_sched_get_priority_min - return minimum RT priority. | |
5913 | * @policy: scheduling class. | |
5914 | * | |
5915 | * this syscall returns the minimum rt_priority that can be used | |
5916 | * by a given scheduling class. | |
5917 | */ | |
5add95d4 | 5918 | SYSCALL_DEFINE1(sched_get_priority_min, int, policy) |
1da177e4 LT |
5919 | { |
5920 | int ret = -EINVAL; | |
5921 | ||
5922 | switch (policy) { | |
5923 | case SCHED_FIFO: | |
5924 | case SCHED_RR: | |
5925 | ret = 1; | |
5926 | break; | |
5927 | case SCHED_NORMAL: | |
b0a9499c | 5928 | case SCHED_BATCH: |
dd41f596 | 5929 | case SCHED_IDLE: |
1da177e4 LT |
5930 | ret = 0; |
5931 | } | |
5932 | return ret; | |
5933 | } | |
5934 | ||
5935 | /** | |
5936 | * sys_sched_rr_get_interval - return the default timeslice of a process. | |
5937 | * @pid: pid of the process. | |
5938 | * @interval: userspace pointer to the timeslice value. | |
5939 | * | |
5940 | * this syscall writes the default timeslice value of a given process | |
5941 | * into the user-space timespec buffer. A value of '0' means infinity. | |
5942 | */ | |
17da2bd9 | 5943 | SYSCALL_DEFINE2(sched_rr_get_interval, pid_t, pid, |
754fe8d2 | 5944 | struct timespec __user *, interval) |
1da177e4 | 5945 | { |
36c8b586 | 5946 | struct task_struct *p; |
a4ec24b4 | 5947 | unsigned int time_slice; |
dba091b9 TG |
5948 | unsigned long flags; |
5949 | struct rq *rq; | |
3a5c359a | 5950 | int retval; |
1da177e4 | 5951 | struct timespec t; |
1da177e4 LT |
5952 | |
5953 | if (pid < 0) | |
3a5c359a | 5954 | return -EINVAL; |
1da177e4 LT |
5955 | |
5956 | retval = -ESRCH; | |
1a551ae7 | 5957 | rcu_read_lock(); |
1da177e4 LT |
5958 | p = find_process_by_pid(pid); |
5959 | if (!p) | |
5960 | goto out_unlock; | |
5961 | ||
5962 | retval = security_task_getscheduler(p); | |
5963 | if (retval) | |
5964 | goto out_unlock; | |
5965 | ||
dba091b9 TG |
5966 | rq = task_rq_lock(p, &flags); |
5967 | time_slice = p->sched_class->get_rr_interval(rq, p); | |
0122ec5b | 5968 | task_rq_unlock(rq, p, &flags); |
a4ec24b4 | 5969 | |
1a551ae7 | 5970 | rcu_read_unlock(); |
a4ec24b4 | 5971 | jiffies_to_timespec(time_slice, &t); |
1da177e4 | 5972 | retval = copy_to_user(interval, &t, sizeof(t)) ? -EFAULT : 0; |
1da177e4 | 5973 | return retval; |
3a5c359a | 5974 | |
1da177e4 | 5975 | out_unlock: |
1a551ae7 | 5976 | rcu_read_unlock(); |
1da177e4 LT |
5977 | return retval; |
5978 | } | |
5979 | ||
7c731e0a | 5980 | static const char stat_nam[] = TASK_STATE_TO_CHAR_STR; |
36c8b586 | 5981 | |
82a1fcb9 | 5982 | void sched_show_task(struct task_struct *p) |
1da177e4 | 5983 | { |
1da177e4 | 5984 | unsigned long free = 0; |
36c8b586 | 5985 | unsigned state; |
1da177e4 | 5986 | |
1da177e4 | 5987 | state = p->state ? __ffs(p->state) + 1 : 0; |
28d0686c | 5988 | printk(KERN_INFO "%-15.15s %c", p->comm, |
2ed6e34f | 5989 | state < sizeof(stat_nam) - 1 ? stat_nam[state] : '?'); |
4bd77321 | 5990 | #if BITS_PER_LONG == 32 |
1da177e4 | 5991 | if (state == TASK_RUNNING) |
3df0fc5b | 5992 | printk(KERN_CONT " running "); |
1da177e4 | 5993 | else |
3df0fc5b | 5994 | printk(KERN_CONT " %08lx ", thread_saved_pc(p)); |
1da177e4 LT |
5995 | #else |
5996 | if (state == TASK_RUNNING) | |
3df0fc5b | 5997 | printk(KERN_CONT " running task "); |
1da177e4 | 5998 | else |
3df0fc5b | 5999 | printk(KERN_CONT " %016lx ", thread_saved_pc(p)); |
1da177e4 LT |
6000 | #endif |
6001 | #ifdef CONFIG_DEBUG_STACK_USAGE | |
7c9f8861 | 6002 | free = stack_not_used(p); |
1da177e4 | 6003 | #endif |
3df0fc5b | 6004 | printk(KERN_CONT "%5lu %5d %6d 0x%08lx\n", free, |
aa47b7e0 DR |
6005 | task_pid_nr(p), task_pid_nr(p->real_parent), |
6006 | (unsigned long)task_thread_info(p)->flags); | |
1da177e4 | 6007 | |
5fb5e6de | 6008 | show_stack(p, NULL); |
1da177e4 LT |
6009 | } |
6010 | ||
e59e2ae2 | 6011 | void show_state_filter(unsigned long state_filter) |
1da177e4 | 6012 | { |
36c8b586 | 6013 | struct task_struct *g, *p; |
1da177e4 | 6014 | |
4bd77321 | 6015 | #if BITS_PER_LONG == 32 |
3df0fc5b PZ |
6016 | printk(KERN_INFO |
6017 | " task PC stack pid father\n"); | |
1da177e4 | 6018 | #else |
3df0fc5b PZ |
6019 | printk(KERN_INFO |
6020 | " task PC stack pid father\n"); | |
1da177e4 LT |
6021 | #endif |
6022 | read_lock(&tasklist_lock); | |
6023 | do_each_thread(g, p) { | |
6024 | /* | |
6025 | * reset the NMI-timeout, listing all files on a slow | |
25985edc | 6026 | * console might take a lot of time: |
1da177e4 LT |
6027 | */ |
6028 | touch_nmi_watchdog(); | |
39bc89fd | 6029 | if (!state_filter || (p->state & state_filter)) |
82a1fcb9 | 6030 | sched_show_task(p); |
1da177e4 LT |
6031 | } while_each_thread(g, p); |
6032 | ||
04c9167f JF |
6033 | touch_all_softlockup_watchdogs(); |
6034 | ||
dd41f596 IM |
6035 | #ifdef CONFIG_SCHED_DEBUG |
6036 | sysrq_sched_debug_show(); | |
6037 | #endif | |
1da177e4 | 6038 | read_unlock(&tasklist_lock); |
e59e2ae2 IM |
6039 | /* |
6040 | * Only show locks if all tasks are dumped: | |
6041 | */ | |
93335a21 | 6042 | if (!state_filter) |
e59e2ae2 | 6043 | debug_show_all_locks(); |
1da177e4 LT |
6044 | } |
6045 | ||
1df21055 IM |
6046 | void __cpuinit init_idle_bootup_task(struct task_struct *idle) |
6047 | { | |
dd41f596 | 6048 | idle->sched_class = &idle_sched_class; |
1df21055 IM |
6049 | } |
6050 | ||
f340c0d1 IM |
6051 | /** |
6052 | * init_idle - set up an idle thread for a given CPU | |
6053 | * @idle: task in question | |
6054 | * @cpu: cpu the idle task belongs to | |
6055 | * | |
6056 | * NOTE: this function does not set the idle thread's NEED_RESCHED | |
6057 | * flag, to make booting more robust. | |
6058 | */ | |
5c1e1767 | 6059 | void __cpuinit init_idle(struct task_struct *idle, int cpu) |
1da177e4 | 6060 | { |
70b97a7f | 6061 | struct rq *rq = cpu_rq(cpu); |
1da177e4 LT |
6062 | unsigned long flags; |
6063 | ||
05fa785c | 6064 | raw_spin_lock_irqsave(&rq->lock, flags); |
5cbd54ef | 6065 | |
dd41f596 | 6066 | __sched_fork(idle); |
06b83b5f | 6067 | idle->state = TASK_RUNNING; |
dd41f596 IM |
6068 | idle->se.exec_start = sched_clock(); |
6069 | ||
1e1b6c51 | 6070 | do_set_cpus_allowed(idle, cpumask_of(cpu)); |
6506cf6c PZ |
6071 | /* |
6072 | * We're having a chicken and egg problem, even though we are | |
6073 | * holding rq->lock, the cpu isn't yet set to this cpu so the | |
6074 | * lockdep check in task_group() will fail. | |
6075 | * | |
6076 | * Similar case to sched_fork(). / Alternatively we could | |
6077 | * use task_rq_lock() here and obtain the other rq->lock. | |
6078 | * | |
6079 | * Silence PROVE_RCU | |
6080 | */ | |
6081 | rcu_read_lock(); | |
dd41f596 | 6082 | __set_task_cpu(idle, cpu); |
6506cf6c | 6083 | rcu_read_unlock(); |
1da177e4 | 6084 | |
1da177e4 | 6085 | rq->curr = rq->idle = idle; |
3ca7a440 PZ |
6086 | #if defined(CONFIG_SMP) |
6087 | idle->on_cpu = 1; | |
4866cde0 | 6088 | #endif |
05fa785c | 6089 | raw_spin_unlock_irqrestore(&rq->lock, flags); |
1da177e4 LT |
6090 | |
6091 | /* Set the preempt count _outside_ the spinlocks! */ | |
a1261f54 | 6092 | task_thread_info(idle)->preempt_count = 0; |
625f2a37 | 6093 | |
dd41f596 IM |
6094 | /* |
6095 | * The idle tasks have their own, simple scheduling class: | |
6096 | */ | |
6097 | idle->sched_class = &idle_sched_class; | |
868baf07 | 6098 | ftrace_graph_init_idle_task(idle, cpu); |
1da177e4 LT |
6099 | } |
6100 | ||
6101 | /* | |
6102 | * In a system that switches off the HZ timer nohz_cpu_mask | |
6103 | * indicates which cpus entered this state. This is used | |
6104 | * in the rcu update to wait only for active cpus. For system | |
6105 | * which do not switch off the HZ timer nohz_cpu_mask should | |
6a7b3dc3 | 6106 | * always be CPU_BITS_NONE. |
1da177e4 | 6107 | */ |
6a7b3dc3 | 6108 | cpumask_var_t nohz_cpu_mask; |
1da177e4 | 6109 | |
19978ca6 IM |
6110 | /* |
6111 | * Increase the granularity value when there are more CPUs, | |
6112 | * because with more CPUs the 'effective latency' as visible | |
6113 | * to users decreases. But the relationship is not linear, | |
6114 | * so pick a second-best guess by going with the log2 of the | |
6115 | * number of CPUs. | |
6116 | * | |
6117 | * This idea comes from the SD scheduler of Con Kolivas: | |
6118 | */ | |
acb4a848 | 6119 | static int get_update_sysctl_factor(void) |
19978ca6 | 6120 | { |
4ca3ef71 | 6121 | unsigned int cpus = min_t(int, num_online_cpus(), 8); |
1983a922 CE |
6122 | unsigned int factor; |
6123 | ||
6124 | switch (sysctl_sched_tunable_scaling) { | |
6125 | case SCHED_TUNABLESCALING_NONE: | |
6126 | factor = 1; | |
6127 | break; | |
6128 | case SCHED_TUNABLESCALING_LINEAR: | |
6129 | factor = cpus; | |
6130 | break; | |
6131 | case SCHED_TUNABLESCALING_LOG: | |
6132 | default: | |
6133 | factor = 1 + ilog2(cpus); | |
6134 | break; | |
6135 | } | |
19978ca6 | 6136 | |
acb4a848 CE |
6137 | return factor; |
6138 | } | |
19978ca6 | 6139 | |
acb4a848 CE |
6140 | static void update_sysctl(void) |
6141 | { | |
6142 | unsigned int factor = get_update_sysctl_factor(); | |
19978ca6 | 6143 | |
0bcdcf28 CE |
6144 | #define SET_SYSCTL(name) \ |
6145 | (sysctl_##name = (factor) * normalized_sysctl_##name) | |
6146 | SET_SYSCTL(sched_min_granularity); | |
6147 | SET_SYSCTL(sched_latency); | |
6148 | SET_SYSCTL(sched_wakeup_granularity); | |
0bcdcf28 CE |
6149 | #undef SET_SYSCTL |
6150 | } | |
55cd5340 | 6151 | |
0bcdcf28 CE |
6152 | static inline void sched_init_granularity(void) |
6153 | { | |
6154 | update_sysctl(); | |
19978ca6 IM |
6155 | } |
6156 | ||
1da177e4 | 6157 | #ifdef CONFIG_SMP |
1e1b6c51 KM |
6158 | void do_set_cpus_allowed(struct task_struct *p, const struct cpumask *new_mask) |
6159 | { | |
6160 | if (p->sched_class && p->sched_class->set_cpus_allowed) | |
6161 | p->sched_class->set_cpus_allowed(p, new_mask); | |
6162 | else { | |
6163 | cpumask_copy(&p->cpus_allowed, new_mask); | |
6164 | p->rt.nr_cpus_allowed = cpumask_weight(new_mask); | |
6165 | } | |
6166 | } | |
6167 | ||
1da177e4 LT |
6168 | /* |
6169 | * This is how migration works: | |
6170 | * | |
969c7921 TH |
6171 | * 1) we invoke migration_cpu_stop() on the target CPU using |
6172 | * stop_one_cpu(). | |
6173 | * 2) stopper starts to run (implicitly forcing the migrated thread | |
6174 | * off the CPU) | |
6175 | * 3) it checks whether the migrated task is still in the wrong runqueue. | |
6176 | * 4) if it's in the wrong runqueue then the migration thread removes | |
1da177e4 | 6177 | * it and puts it into the right queue. |
969c7921 TH |
6178 | * 5) stopper completes and stop_one_cpu() returns and the migration |
6179 | * is done. | |
1da177e4 LT |
6180 | */ |
6181 | ||
6182 | /* | |
6183 | * Change a given task's CPU affinity. Migrate the thread to a | |
6184 | * proper CPU and schedule it away if the CPU it's executing on | |
6185 | * is removed from the allowed bitmask. | |
6186 | * | |
6187 | * NOTE: the caller must have a valid reference to the task, the | |
41a2d6cf | 6188 | * task must not exit() & deallocate itself prematurely. The |
1da177e4 LT |
6189 | * call is not atomic; no spinlocks may be held. |
6190 | */ | |
96f874e2 | 6191 | int set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask) |
1da177e4 LT |
6192 | { |
6193 | unsigned long flags; | |
70b97a7f | 6194 | struct rq *rq; |
969c7921 | 6195 | unsigned int dest_cpu; |
48f24c4d | 6196 | int ret = 0; |
1da177e4 LT |
6197 | |
6198 | rq = task_rq_lock(p, &flags); | |
e2912009 | 6199 | |
db44fc01 YZ |
6200 | if (cpumask_equal(&p->cpus_allowed, new_mask)) |
6201 | goto out; | |
6202 | ||
6ad4c188 | 6203 | if (!cpumask_intersects(new_mask, cpu_active_mask)) { |
1da177e4 LT |
6204 | ret = -EINVAL; |
6205 | goto out; | |
6206 | } | |
6207 | ||
db44fc01 | 6208 | if (unlikely((p->flags & PF_THREAD_BOUND) && p != current)) { |
9985b0ba DR |
6209 | ret = -EINVAL; |
6210 | goto out; | |
6211 | } | |
6212 | ||
1e1b6c51 | 6213 | do_set_cpus_allowed(p, new_mask); |
73fe6aae | 6214 | |
1da177e4 | 6215 | /* Can the task run on the task's current CPU? If so, we're done */ |
96f874e2 | 6216 | if (cpumask_test_cpu(task_cpu(p), new_mask)) |
1da177e4 LT |
6217 | goto out; |
6218 | ||
969c7921 | 6219 | dest_cpu = cpumask_any_and(cpu_active_mask, new_mask); |
bd8e7dde | 6220 | if (p->on_rq) { |
969c7921 | 6221 | struct migration_arg arg = { p, dest_cpu }; |
1da177e4 | 6222 | /* Need help from migration thread: drop lock and wait. */ |
0122ec5b | 6223 | task_rq_unlock(rq, p, &flags); |
969c7921 | 6224 | stop_one_cpu(cpu_of(rq), migration_cpu_stop, &arg); |
1da177e4 LT |
6225 | tlb_migrate_finish(p->mm); |
6226 | return 0; | |
6227 | } | |
6228 | out: | |
0122ec5b | 6229 | task_rq_unlock(rq, p, &flags); |
48f24c4d | 6230 | |
1da177e4 LT |
6231 | return ret; |
6232 | } | |
cd8ba7cd | 6233 | EXPORT_SYMBOL_GPL(set_cpus_allowed_ptr); |
1da177e4 LT |
6234 | |
6235 | /* | |
41a2d6cf | 6236 | * Move (not current) task off this cpu, onto dest cpu. We're doing |
1da177e4 LT |
6237 | * this because either it can't run here any more (set_cpus_allowed() |
6238 | * away from this CPU, or CPU going down), or because we're | |
6239 | * attempting to rebalance this task on exec (sched_exec). | |
6240 | * | |
6241 | * So we race with normal scheduler movements, but that's OK, as long | |
6242 | * as the task is no longer on this CPU. | |
efc30814 KK |
6243 | * |
6244 | * Returns non-zero if task was successfully migrated. | |
1da177e4 | 6245 | */ |
efc30814 | 6246 | static int __migrate_task(struct task_struct *p, int src_cpu, int dest_cpu) |
1da177e4 | 6247 | { |
70b97a7f | 6248 | struct rq *rq_dest, *rq_src; |
e2912009 | 6249 | int ret = 0; |
1da177e4 | 6250 | |
e761b772 | 6251 | if (unlikely(!cpu_active(dest_cpu))) |
efc30814 | 6252 | return ret; |
1da177e4 LT |
6253 | |
6254 | rq_src = cpu_rq(src_cpu); | |
6255 | rq_dest = cpu_rq(dest_cpu); | |
6256 | ||
0122ec5b | 6257 | raw_spin_lock(&p->pi_lock); |
1da177e4 LT |
6258 | double_rq_lock(rq_src, rq_dest); |
6259 | /* Already moved. */ | |
6260 | if (task_cpu(p) != src_cpu) | |
b1e38734 | 6261 | goto done; |
1da177e4 | 6262 | /* Affinity changed (again). */ |
96f874e2 | 6263 | if (!cpumask_test_cpu(dest_cpu, &p->cpus_allowed)) |
b1e38734 | 6264 | goto fail; |
1da177e4 | 6265 | |
e2912009 PZ |
6266 | /* |
6267 | * If we're not on a rq, the next wake-up will ensure we're | |
6268 | * placed properly. | |
6269 | */ | |
fd2f4419 | 6270 | if (p->on_rq) { |
2e1cb74a | 6271 | deactivate_task(rq_src, p, 0); |
e2912009 | 6272 | set_task_cpu(p, dest_cpu); |
dd41f596 | 6273 | activate_task(rq_dest, p, 0); |
15afe09b | 6274 | check_preempt_curr(rq_dest, p, 0); |
1da177e4 | 6275 | } |
b1e38734 | 6276 | done: |
efc30814 | 6277 | ret = 1; |
b1e38734 | 6278 | fail: |
1da177e4 | 6279 | double_rq_unlock(rq_src, rq_dest); |
0122ec5b | 6280 | raw_spin_unlock(&p->pi_lock); |
efc30814 | 6281 | return ret; |
1da177e4 LT |
6282 | } |
6283 | ||
6284 | /* | |
969c7921 TH |
6285 | * migration_cpu_stop - this will be executed by a highprio stopper thread |
6286 | * and performs thread migration by bumping thread off CPU then | |
6287 | * 'pushing' onto another runqueue. | |
1da177e4 | 6288 | */ |
969c7921 | 6289 | static int migration_cpu_stop(void *data) |
1da177e4 | 6290 | { |
969c7921 | 6291 | struct migration_arg *arg = data; |
f7b4cddc | 6292 | |
969c7921 TH |
6293 | /* |
6294 | * The original target cpu might have gone down and we might | |
6295 | * be on another cpu but it doesn't matter. | |
6296 | */ | |
f7b4cddc | 6297 | local_irq_disable(); |
969c7921 | 6298 | __migrate_task(arg->task, raw_smp_processor_id(), arg->dest_cpu); |
f7b4cddc | 6299 | local_irq_enable(); |
1da177e4 | 6300 | return 0; |
f7b4cddc ON |
6301 | } |
6302 | ||
1da177e4 | 6303 | #ifdef CONFIG_HOTPLUG_CPU |
48c5ccae | 6304 | |
054b9108 | 6305 | /* |
48c5ccae PZ |
6306 | * Ensures that the idle task is using init_mm right before its cpu goes |
6307 | * offline. | |
054b9108 | 6308 | */ |
48c5ccae | 6309 | void idle_task_exit(void) |
1da177e4 | 6310 | { |
48c5ccae | 6311 | struct mm_struct *mm = current->active_mm; |
e76bd8d9 | 6312 | |
48c5ccae | 6313 | BUG_ON(cpu_online(smp_processor_id())); |
e76bd8d9 | 6314 | |
48c5ccae PZ |
6315 | if (mm != &init_mm) |
6316 | switch_mm(mm, &init_mm, current); | |
6317 | mmdrop(mm); | |
1da177e4 LT |
6318 | } |
6319 | ||
6320 | /* | |
6321 | * While a dead CPU has no uninterruptible tasks queued at this point, | |
6322 | * it might still have a nonzero ->nr_uninterruptible counter, because | |
6323 | * for performance reasons the counter is not stricly tracking tasks to | |
6324 | * their home CPUs. So we just add the counter to another CPU's counter, | |
6325 | * to keep the global sum constant after CPU-down: | |
6326 | */ | |
70b97a7f | 6327 | static void migrate_nr_uninterruptible(struct rq *rq_src) |
1da177e4 | 6328 | { |
6ad4c188 | 6329 | struct rq *rq_dest = cpu_rq(cpumask_any(cpu_active_mask)); |
1da177e4 | 6330 | |
1da177e4 LT |
6331 | rq_dest->nr_uninterruptible += rq_src->nr_uninterruptible; |
6332 | rq_src->nr_uninterruptible = 0; | |
1da177e4 LT |
6333 | } |
6334 | ||
dd41f596 | 6335 | /* |
48c5ccae | 6336 | * remove the tasks which were accounted by rq from calc_load_tasks. |
1da177e4 | 6337 | */ |
48c5ccae | 6338 | static void calc_global_load_remove(struct rq *rq) |
1da177e4 | 6339 | { |
48c5ccae PZ |
6340 | atomic_long_sub(rq->calc_load_active, &calc_load_tasks); |
6341 | rq->calc_load_active = 0; | |
1da177e4 LT |
6342 | } |
6343 | ||
8cb120d3 PT |
6344 | #ifdef CONFIG_CFS_BANDWIDTH |
6345 | static void unthrottle_offline_cfs_rqs(struct rq *rq) | |
6346 | { | |
6347 | struct cfs_rq *cfs_rq; | |
6348 | ||
6349 | for_each_leaf_cfs_rq(rq, cfs_rq) { | |
6350 | struct cfs_bandwidth *cfs_b = tg_cfs_bandwidth(cfs_rq->tg); | |
6351 | ||
6352 | if (!cfs_rq->runtime_enabled) | |
6353 | continue; | |
6354 | ||
6355 | /* | |
6356 | * clock_task is not advancing so we just need to make sure | |
6357 | * there's some valid quota amount | |
6358 | */ | |
6359 | cfs_rq->runtime_remaining = cfs_b->quota; | |
6360 | if (cfs_rq_throttled(cfs_rq)) | |
6361 | unthrottle_cfs_rq(cfs_rq); | |
6362 | } | |
6363 | } | |
6364 | #else | |
6365 | static void unthrottle_offline_cfs_rqs(struct rq *rq) {} | |
6366 | #endif | |
6367 | ||
48f24c4d | 6368 | /* |
48c5ccae PZ |
6369 | * Migrate all tasks from the rq, sleeping tasks will be migrated by |
6370 | * try_to_wake_up()->select_task_rq(). | |
6371 | * | |
6372 | * Called with rq->lock held even though we'er in stop_machine() and | |
6373 | * there's no concurrency possible, we hold the required locks anyway | |
6374 | * because of lock validation efforts. | |
1da177e4 | 6375 | */ |
48c5ccae | 6376 | static void migrate_tasks(unsigned int dead_cpu) |
1da177e4 | 6377 | { |
70b97a7f | 6378 | struct rq *rq = cpu_rq(dead_cpu); |
48c5ccae PZ |
6379 | struct task_struct *next, *stop = rq->stop; |
6380 | int dest_cpu; | |
1da177e4 LT |
6381 | |
6382 | /* | |
48c5ccae PZ |
6383 | * Fudge the rq selection such that the below task selection loop |
6384 | * doesn't get stuck on the currently eligible stop task. | |
6385 | * | |
6386 | * We're currently inside stop_machine() and the rq is either stuck | |
6387 | * in the stop_machine_cpu_stop() loop, or we're executing this code, | |
6388 | * either way we should never end up calling schedule() until we're | |
6389 | * done here. | |
1da177e4 | 6390 | */ |
48c5ccae | 6391 | rq->stop = NULL; |
48f24c4d | 6392 | |
8cb120d3 PT |
6393 | /* Ensure any throttled groups are reachable by pick_next_task */ |
6394 | unthrottle_offline_cfs_rqs(rq); | |
6395 | ||
dd41f596 | 6396 | for ( ; ; ) { |
48c5ccae PZ |
6397 | /* |
6398 | * There's this thread running, bail when that's the only | |
6399 | * remaining thread. | |
6400 | */ | |
6401 | if (rq->nr_running == 1) | |
dd41f596 | 6402 | break; |
48c5ccae | 6403 | |
b67802ea | 6404 | next = pick_next_task(rq); |
48c5ccae | 6405 | BUG_ON(!next); |
79c53799 | 6406 | next->sched_class->put_prev_task(rq, next); |
e692ab53 | 6407 | |
48c5ccae PZ |
6408 | /* Find suitable destination for @next, with force if needed. */ |
6409 | dest_cpu = select_fallback_rq(dead_cpu, next); | |
6410 | raw_spin_unlock(&rq->lock); | |
6411 | ||
6412 | __migrate_task(next, dead_cpu, dest_cpu); | |
6413 | ||
6414 | raw_spin_lock(&rq->lock); | |
1da177e4 | 6415 | } |
dce48a84 | 6416 | |
48c5ccae | 6417 | rq->stop = stop; |
dce48a84 | 6418 | } |
48c5ccae | 6419 | |
1da177e4 LT |
6420 | #endif /* CONFIG_HOTPLUG_CPU */ |
6421 | ||
e692ab53 NP |
6422 | #if defined(CONFIG_SCHED_DEBUG) && defined(CONFIG_SYSCTL) |
6423 | ||
6424 | static struct ctl_table sd_ctl_dir[] = { | |
e0361851 AD |
6425 | { |
6426 | .procname = "sched_domain", | |
c57baf1e | 6427 | .mode = 0555, |
e0361851 | 6428 | }, |
56992309 | 6429 | {} |
e692ab53 NP |
6430 | }; |
6431 | ||
6432 | static struct ctl_table sd_ctl_root[] = { | |
e0361851 AD |
6433 | { |
6434 | .procname = "kernel", | |
c57baf1e | 6435 | .mode = 0555, |
e0361851 AD |
6436 | .child = sd_ctl_dir, |
6437 | }, | |
56992309 | 6438 | {} |
e692ab53 NP |
6439 | }; |
6440 | ||
6441 | static struct ctl_table *sd_alloc_ctl_entry(int n) | |
6442 | { | |
6443 | struct ctl_table *entry = | |
5cf9f062 | 6444 | kcalloc(n, sizeof(struct ctl_table), GFP_KERNEL); |
e692ab53 | 6445 | |
e692ab53 NP |
6446 | return entry; |
6447 | } | |
6448 | ||
6382bc90 MM |
6449 | static void sd_free_ctl_entry(struct ctl_table **tablep) |
6450 | { | |
cd790076 | 6451 | struct ctl_table *entry; |
6382bc90 | 6452 | |
cd790076 MM |
6453 | /* |
6454 | * In the intermediate directories, both the child directory and | |
6455 | * procname are dynamically allocated and could fail but the mode | |
41a2d6cf | 6456 | * will always be set. In the lowest directory the names are |
cd790076 MM |
6457 | * static strings and all have proc handlers. |
6458 | */ | |
6459 | for (entry = *tablep; entry->mode; entry++) { | |
6382bc90 MM |
6460 | if (entry->child) |
6461 | sd_free_ctl_entry(&entry->child); | |
cd790076 MM |
6462 | if (entry->proc_handler == NULL) |
6463 | kfree(entry->procname); | |
6464 | } | |
6382bc90 MM |
6465 | |
6466 | kfree(*tablep); | |
6467 | *tablep = NULL; | |
6468 | } | |
6469 | ||
e692ab53 | 6470 | static void |
e0361851 | 6471 | set_table_entry(struct ctl_table *entry, |
e692ab53 NP |
6472 | const char *procname, void *data, int maxlen, |
6473 | mode_t mode, proc_handler *proc_handler) | |
6474 | { | |
e692ab53 NP |
6475 | entry->procname = procname; |
6476 | entry->data = data; | |
6477 | entry->maxlen = maxlen; | |
6478 | entry->mode = mode; | |
6479 | entry->proc_handler = proc_handler; | |
6480 | } | |
6481 | ||
6482 | static struct ctl_table * | |
6483 | sd_alloc_ctl_domain_table(struct sched_domain *sd) | |
6484 | { | |
a5d8c348 | 6485 | struct ctl_table *table = sd_alloc_ctl_entry(13); |
e692ab53 | 6486 | |
ad1cdc1d MM |
6487 | if (table == NULL) |
6488 | return NULL; | |
6489 | ||
e0361851 | 6490 | set_table_entry(&table[0], "min_interval", &sd->min_interval, |
e692ab53 | 6491 | sizeof(long), 0644, proc_doulongvec_minmax); |
e0361851 | 6492 | set_table_entry(&table[1], "max_interval", &sd->max_interval, |
e692ab53 | 6493 | sizeof(long), 0644, proc_doulongvec_minmax); |
e0361851 | 6494 | set_table_entry(&table[2], "busy_idx", &sd->busy_idx, |
e692ab53 | 6495 | sizeof(int), 0644, proc_dointvec_minmax); |
e0361851 | 6496 | set_table_entry(&table[3], "idle_idx", &sd->idle_idx, |
e692ab53 | 6497 | sizeof(int), 0644, proc_dointvec_minmax); |
e0361851 | 6498 | set_table_entry(&table[4], "newidle_idx", &sd->newidle_idx, |
e692ab53 | 6499 | sizeof(int), 0644, proc_dointvec_minmax); |
e0361851 | 6500 | set_table_entry(&table[5], "wake_idx", &sd->wake_idx, |
e692ab53 | 6501 | sizeof(int), 0644, proc_dointvec_minmax); |
e0361851 | 6502 | set_table_entry(&table[6], "forkexec_idx", &sd->forkexec_idx, |
e692ab53 | 6503 | sizeof(int), 0644, proc_dointvec_minmax); |
e0361851 | 6504 | set_table_entry(&table[7], "busy_factor", &sd->busy_factor, |
e692ab53 | 6505 | sizeof(int), 0644, proc_dointvec_minmax); |
e0361851 | 6506 | set_table_entry(&table[8], "imbalance_pct", &sd->imbalance_pct, |
e692ab53 | 6507 | sizeof(int), 0644, proc_dointvec_minmax); |
ace8b3d6 | 6508 | set_table_entry(&table[9], "cache_nice_tries", |
e692ab53 NP |
6509 | &sd->cache_nice_tries, |
6510 | sizeof(int), 0644, proc_dointvec_minmax); | |
ace8b3d6 | 6511 | set_table_entry(&table[10], "flags", &sd->flags, |
e692ab53 | 6512 | sizeof(int), 0644, proc_dointvec_minmax); |
a5d8c348 IM |
6513 | set_table_entry(&table[11], "name", sd->name, |
6514 | CORENAME_MAX_SIZE, 0444, proc_dostring); | |
6515 | /* &table[12] is terminator */ | |
e692ab53 NP |
6516 | |
6517 | return table; | |
6518 | } | |
6519 | ||
9a4e7159 | 6520 | static ctl_table *sd_alloc_ctl_cpu_table(int cpu) |
e692ab53 NP |
6521 | { |
6522 | struct ctl_table *entry, *table; | |
6523 | struct sched_domain *sd; | |
6524 | int domain_num = 0, i; | |
6525 | char buf[32]; | |
6526 | ||
6527 | for_each_domain(cpu, sd) | |
6528 | domain_num++; | |
6529 | entry = table = sd_alloc_ctl_entry(domain_num + 1); | |
ad1cdc1d MM |
6530 | if (table == NULL) |
6531 | return NULL; | |
e692ab53 NP |
6532 | |
6533 | i = 0; | |
6534 | for_each_domain(cpu, sd) { | |
6535 | snprintf(buf, 32, "domain%d", i); | |
e692ab53 | 6536 | entry->procname = kstrdup(buf, GFP_KERNEL); |
c57baf1e | 6537 | entry->mode = 0555; |
e692ab53 NP |
6538 | entry->child = sd_alloc_ctl_domain_table(sd); |
6539 | entry++; | |
6540 | i++; | |
6541 | } | |
6542 | return table; | |
6543 | } | |
6544 | ||
6545 | static struct ctl_table_header *sd_sysctl_header; | |
6382bc90 | 6546 | static void register_sched_domain_sysctl(void) |
e692ab53 | 6547 | { |
6ad4c188 | 6548 | int i, cpu_num = num_possible_cpus(); |
e692ab53 NP |
6549 | struct ctl_table *entry = sd_alloc_ctl_entry(cpu_num + 1); |
6550 | char buf[32]; | |
6551 | ||
7378547f MM |
6552 | WARN_ON(sd_ctl_dir[0].child); |
6553 | sd_ctl_dir[0].child = entry; | |
6554 | ||
ad1cdc1d MM |
6555 | if (entry == NULL) |
6556 | return; | |
6557 | ||
6ad4c188 | 6558 | for_each_possible_cpu(i) { |
e692ab53 | 6559 | snprintf(buf, 32, "cpu%d", i); |
e692ab53 | 6560 | entry->procname = kstrdup(buf, GFP_KERNEL); |
c57baf1e | 6561 | entry->mode = 0555; |
e692ab53 | 6562 | entry->child = sd_alloc_ctl_cpu_table(i); |
97b6ea7b | 6563 | entry++; |
e692ab53 | 6564 | } |
7378547f MM |
6565 | |
6566 | WARN_ON(sd_sysctl_header); | |
e692ab53 NP |
6567 | sd_sysctl_header = register_sysctl_table(sd_ctl_root); |
6568 | } | |
6382bc90 | 6569 | |
7378547f | 6570 | /* may be called multiple times per register */ |
6382bc90 MM |
6571 | static void unregister_sched_domain_sysctl(void) |
6572 | { | |
7378547f MM |
6573 | if (sd_sysctl_header) |
6574 | unregister_sysctl_table(sd_sysctl_header); | |
6382bc90 | 6575 | sd_sysctl_header = NULL; |
7378547f MM |
6576 | if (sd_ctl_dir[0].child) |
6577 | sd_free_ctl_entry(&sd_ctl_dir[0].child); | |
6382bc90 | 6578 | } |
e692ab53 | 6579 | #else |
6382bc90 MM |
6580 | static void register_sched_domain_sysctl(void) |
6581 | { | |
6582 | } | |
6583 | static void unregister_sched_domain_sysctl(void) | |
e692ab53 NP |
6584 | { |
6585 | } | |
6586 | #endif | |
6587 | ||
1f11eb6a GH |
6588 | static void set_rq_online(struct rq *rq) |
6589 | { | |
6590 | if (!rq->online) { | |
6591 | const struct sched_class *class; | |
6592 | ||
c6c4927b | 6593 | cpumask_set_cpu(rq->cpu, rq->rd->online); |
1f11eb6a GH |
6594 | rq->online = 1; |
6595 | ||
6596 | for_each_class(class) { | |
6597 | if (class->rq_online) | |
6598 | class->rq_online(rq); | |
6599 | } | |
6600 | } | |
6601 | } | |
6602 | ||
6603 | static void set_rq_offline(struct rq *rq) | |
6604 | { | |
6605 | if (rq->online) { | |
6606 | const struct sched_class *class; | |
6607 | ||
6608 | for_each_class(class) { | |
6609 | if (class->rq_offline) | |
6610 | class->rq_offline(rq); | |
6611 | } | |
6612 | ||
c6c4927b | 6613 | cpumask_clear_cpu(rq->cpu, rq->rd->online); |
1f11eb6a GH |
6614 | rq->online = 0; |
6615 | } | |
6616 | } | |
6617 | ||
1da177e4 LT |
6618 | /* |
6619 | * migration_call - callback that gets triggered when a CPU is added. | |
6620 | * Here we can start up the necessary migration thread for the new CPU. | |
6621 | */ | |
48f24c4d IM |
6622 | static int __cpuinit |
6623 | migration_call(struct notifier_block *nfb, unsigned long action, void *hcpu) | |
1da177e4 | 6624 | { |
48f24c4d | 6625 | int cpu = (long)hcpu; |
1da177e4 | 6626 | unsigned long flags; |
969c7921 | 6627 | struct rq *rq = cpu_rq(cpu); |
1da177e4 | 6628 | |
48c5ccae | 6629 | switch (action & ~CPU_TASKS_FROZEN) { |
5be9361c | 6630 | |
1da177e4 | 6631 | case CPU_UP_PREPARE: |
a468d389 | 6632 | rq->calc_load_update = calc_load_update; |
1da177e4 | 6633 | break; |
48f24c4d | 6634 | |
1da177e4 | 6635 | case CPU_ONLINE: |
1f94ef59 | 6636 | /* Update our root-domain */ |
05fa785c | 6637 | raw_spin_lock_irqsave(&rq->lock, flags); |
1f94ef59 | 6638 | if (rq->rd) { |
c6c4927b | 6639 | BUG_ON(!cpumask_test_cpu(cpu, rq->rd->span)); |
1f11eb6a GH |
6640 | |
6641 | set_rq_online(rq); | |
1f94ef59 | 6642 | } |
05fa785c | 6643 | raw_spin_unlock_irqrestore(&rq->lock, flags); |
1da177e4 | 6644 | break; |
48f24c4d | 6645 | |
1da177e4 | 6646 | #ifdef CONFIG_HOTPLUG_CPU |
08f503b0 | 6647 | case CPU_DYING: |
317f3941 | 6648 | sched_ttwu_pending(); |
57d885fe | 6649 | /* Update our root-domain */ |
05fa785c | 6650 | raw_spin_lock_irqsave(&rq->lock, flags); |
57d885fe | 6651 | if (rq->rd) { |
c6c4927b | 6652 | BUG_ON(!cpumask_test_cpu(cpu, rq->rd->span)); |
1f11eb6a | 6653 | set_rq_offline(rq); |
57d885fe | 6654 | } |
48c5ccae PZ |
6655 | migrate_tasks(cpu); |
6656 | BUG_ON(rq->nr_running != 1); /* the migration thread */ | |
05fa785c | 6657 | raw_spin_unlock_irqrestore(&rq->lock, flags); |
48c5ccae PZ |
6658 | |
6659 | migrate_nr_uninterruptible(rq); | |
6660 | calc_global_load_remove(rq); | |
57d885fe | 6661 | break; |
1da177e4 LT |
6662 | #endif |
6663 | } | |
49c022e6 PZ |
6664 | |
6665 | update_max_interval(); | |
6666 | ||
1da177e4 LT |
6667 | return NOTIFY_OK; |
6668 | } | |
6669 | ||
f38b0820 PM |
6670 | /* |
6671 | * Register at high priority so that task migration (migrate_all_tasks) | |
6672 | * happens before everything else. This has to be lower priority than | |
cdd6c482 | 6673 | * the notifier in the perf_event subsystem, though. |
1da177e4 | 6674 | */ |
26c2143b | 6675 | static struct notifier_block __cpuinitdata migration_notifier = { |
1da177e4 | 6676 | .notifier_call = migration_call, |
50a323b7 | 6677 | .priority = CPU_PRI_MIGRATION, |
1da177e4 LT |
6678 | }; |
6679 | ||
3a101d05 TH |
6680 | static int __cpuinit sched_cpu_active(struct notifier_block *nfb, |
6681 | unsigned long action, void *hcpu) | |
6682 | { | |
6683 | switch (action & ~CPU_TASKS_FROZEN) { | |
6684 | case CPU_ONLINE: | |
6685 | case CPU_DOWN_FAILED: | |
6686 | set_cpu_active((long)hcpu, true); | |
6687 | return NOTIFY_OK; | |
6688 | default: | |
6689 | return NOTIFY_DONE; | |
6690 | } | |
6691 | } | |
6692 | ||
6693 | static int __cpuinit sched_cpu_inactive(struct notifier_block *nfb, | |
6694 | unsigned long action, void *hcpu) | |
6695 | { | |
6696 | switch (action & ~CPU_TASKS_FROZEN) { | |
6697 | case CPU_DOWN_PREPARE: | |
6698 | set_cpu_active((long)hcpu, false); | |
6699 | return NOTIFY_OK; | |
6700 | default: | |
6701 | return NOTIFY_DONE; | |
6702 | } | |
6703 | } | |
6704 | ||
7babe8db | 6705 | static int __init migration_init(void) |
1da177e4 LT |
6706 | { |
6707 | void *cpu = (void *)(long)smp_processor_id(); | |
07dccf33 | 6708 | int err; |
48f24c4d | 6709 | |
3a101d05 | 6710 | /* Initialize migration for the boot CPU */ |
07dccf33 AM |
6711 | err = migration_call(&migration_notifier, CPU_UP_PREPARE, cpu); |
6712 | BUG_ON(err == NOTIFY_BAD); | |
1da177e4 LT |
6713 | migration_call(&migration_notifier, CPU_ONLINE, cpu); |
6714 | register_cpu_notifier(&migration_notifier); | |
7babe8db | 6715 | |
3a101d05 TH |
6716 | /* Register cpu active notifiers */ |
6717 | cpu_notifier(sched_cpu_active, CPU_PRI_SCHED_ACTIVE); | |
6718 | cpu_notifier(sched_cpu_inactive, CPU_PRI_SCHED_INACTIVE); | |
6719 | ||
a004cd42 | 6720 | return 0; |
1da177e4 | 6721 | } |
7babe8db | 6722 | early_initcall(migration_init); |
1da177e4 LT |
6723 | #endif |
6724 | ||
6725 | #ifdef CONFIG_SMP | |
476f3534 | 6726 | |
4cb98839 PZ |
6727 | static cpumask_var_t sched_domains_tmpmask; /* sched_domains_mutex */ |
6728 | ||
3e9830dc | 6729 | #ifdef CONFIG_SCHED_DEBUG |
4dcf6aff | 6730 | |
f6630114 MT |
6731 | static __read_mostly int sched_domain_debug_enabled; |
6732 | ||
6733 | static int __init sched_domain_debug_setup(char *str) | |
6734 | { | |
6735 | sched_domain_debug_enabled = 1; | |
6736 | ||
6737 | return 0; | |
6738 | } | |
6739 | early_param("sched_debug", sched_domain_debug_setup); | |
6740 | ||
7c16ec58 | 6741 | static int sched_domain_debug_one(struct sched_domain *sd, int cpu, int level, |
96f874e2 | 6742 | struct cpumask *groupmask) |
1da177e4 | 6743 | { |
4dcf6aff | 6744 | struct sched_group *group = sd->groups; |
434d53b0 | 6745 | char str[256]; |
1da177e4 | 6746 | |
968ea6d8 | 6747 | cpulist_scnprintf(str, sizeof(str), sched_domain_span(sd)); |
96f874e2 | 6748 | cpumask_clear(groupmask); |
4dcf6aff IM |
6749 | |
6750 | printk(KERN_DEBUG "%*s domain %d: ", level, "", level); | |
6751 | ||
6752 | if (!(sd->flags & SD_LOAD_BALANCE)) { | |
3df0fc5b | 6753 | printk("does not load-balance\n"); |
4dcf6aff | 6754 | if (sd->parent) |
3df0fc5b PZ |
6755 | printk(KERN_ERR "ERROR: !SD_LOAD_BALANCE domain" |
6756 | " has parent"); | |
4dcf6aff | 6757 | return -1; |
41c7ce9a NP |
6758 | } |
6759 | ||
3df0fc5b | 6760 | printk(KERN_CONT "span %s level %s\n", str, sd->name); |
4dcf6aff | 6761 | |
758b2cdc | 6762 | if (!cpumask_test_cpu(cpu, sched_domain_span(sd))) { |
3df0fc5b PZ |
6763 | printk(KERN_ERR "ERROR: domain->span does not contain " |
6764 | "CPU%d\n", cpu); | |
4dcf6aff | 6765 | } |
758b2cdc | 6766 | if (!cpumask_test_cpu(cpu, sched_group_cpus(group))) { |
3df0fc5b PZ |
6767 | printk(KERN_ERR "ERROR: domain->groups does not contain" |
6768 | " CPU%d\n", cpu); | |
4dcf6aff | 6769 | } |
1da177e4 | 6770 | |
4dcf6aff | 6771 | printk(KERN_DEBUG "%*s groups:", level + 1, ""); |
1da177e4 | 6772 | do { |
4dcf6aff | 6773 | if (!group) { |
3df0fc5b PZ |
6774 | printk("\n"); |
6775 | printk(KERN_ERR "ERROR: group is NULL\n"); | |
1da177e4 LT |
6776 | break; |
6777 | } | |
6778 | ||
9c3f75cb | 6779 | if (!group->sgp->power) { |
3df0fc5b PZ |
6780 | printk(KERN_CONT "\n"); |
6781 | printk(KERN_ERR "ERROR: domain->cpu_power not " | |
6782 | "set\n"); | |
4dcf6aff IM |
6783 | break; |
6784 | } | |
1da177e4 | 6785 | |
758b2cdc | 6786 | if (!cpumask_weight(sched_group_cpus(group))) { |
3df0fc5b PZ |
6787 | printk(KERN_CONT "\n"); |
6788 | printk(KERN_ERR "ERROR: empty group\n"); | |
4dcf6aff IM |
6789 | break; |
6790 | } | |
1da177e4 | 6791 | |
758b2cdc | 6792 | if (cpumask_intersects(groupmask, sched_group_cpus(group))) { |
3df0fc5b PZ |
6793 | printk(KERN_CONT "\n"); |
6794 | printk(KERN_ERR "ERROR: repeated CPUs\n"); | |
4dcf6aff IM |
6795 | break; |
6796 | } | |
1da177e4 | 6797 | |
758b2cdc | 6798 | cpumask_or(groupmask, groupmask, sched_group_cpus(group)); |
1da177e4 | 6799 | |
968ea6d8 | 6800 | cpulist_scnprintf(str, sizeof(str), sched_group_cpus(group)); |
381512cf | 6801 | |
3df0fc5b | 6802 | printk(KERN_CONT " %s", str); |
9c3f75cb | 6803 | if (group->sgp->power != SCHED_POWER_SCALE) { |
3df0fc5b | 6804 | printk(KERN_CONT " (cpu_power = %d)", |
9c3f75cb | 6805 | group->sgp->power); |
381512cf | 6806 | } |
1da177e4 | 6807 | |
4dcf6aff IM |
6808 | group = group->next; |
6809 | } while (group != sd->groups); | |
3df0fc5b | 6810 | printk(KERN_CONT "\n"); |
1da177e4 | 6811 | |
758b2cdc | 6812 | if (!cpumask_equal(sched_domain_span(sd), groupmask)) |
3df0fc5b | 6813 | printk(KERN_ERR "ERROR: groups don't span domain->span\n"); |
1da177e4 | 6814 | |
758b2cdc RR |
6815 | if (sd->parent && |
6816 | !cpumask_subset(groupmask, sched_domain_span(sd->parent))) | |
3df0fc5b PZ |
6817 | printk(KERN_ERR "ERROR: parent span is not a superset " |
6818 | "of domain->span\n"); | |
4dcf6aff IM |
6819 | return 0; |
6820 | } | |
1da177e4 | 6821 | |
4dcf6aff IM |
6822 | static void sched_domain_debug(struct sched_domain *sd, int cpu) |
6823 | { | |
6824 | int level = 0; | |
1da177e4 | 6825 | |
f6630114 MT |
6826 | if (!sched_domain_debug_enabled) |
6827 | return; | |
6828 | ||
4dcf6aff IM |
6829 | if (!sd) { |
6830 | printk(KERN_DEBUG "CPU%d attaching NULL sched-domain.\n", cpu); | |
6831 | return; | |
6832 | } | |
1da177e4 | 6833 | |
4dcf6aff IM |
6834 | printk(KERN_DEBUG "CPU%d attaching sched-domain:\n", cpu); |
6835 | ||
6836 | for (;;) { | |
4cb98839 | 6837 | if (sched_domain_debug_one(sd, cpu, level, sched_domains_tmpmask)) |
4dcf6aff | 6838 | break; |
1da177e4 LT |
6839 | level++; |
6840 | sd = sd->parent; | |
33859f7f | 6841 | if (!sd) |
4dcf6aff IM |
6842 | break; |
6843 | } | |
1da177e4 | 6844 | } |
6d6bc0ad | 6845 | #else /* !CONFIG_SCHED_DEBUG */ |
48f24c4d | 6846 | # define sched_domain_debug(sd, cpu) do { } while (0) |
6d6bc0ad | 6847 | #endif /* CONFIG_SCHED_DEBUG */ |
1da177e4 | 6848 | |
1a20ff27 | 6849 | static int sd_degenerate(struct sched_domain *sd) |
245af2c7 | 6850 | { |
758b2cdc | 6851 | if (cpumask_weight(sched_domain_span(sd)) == 1) |
245af2c7 SS |
6852 | return 1; |
6853 | ||
6854 | /* Following flags need at least 2 groups */ | |
6855 | if (sd->flags & (SD_LOAD_BALANCE | | |
6856 | SD_BALANCE_NEWIDLE | | |
6857 | SD_BALANCE_FORK | | |
89c4710e SS |
6858 | SD_BALANCE_EXEC | |
6859 | SD_SHARE_CPUPOWER | | |
6860 | SD_SHARE_PKG_RESOURCES)) { | |
245af2c7 SS |
6861 | if (sd->groups != sd->groups->next) |
6862 | return 0; | |
6863 | } | |
6864 | ||
6865 | /* Following flags don't use groups */ | |
c88d5910 | 6866 | if (sd->flags & (SD_WAKE_AFFINE)) |
245af2c7 SS |
6867 | return 0; |
6868 | ||
6869 | return 1; | |
6870 | } | |
6871 | ||
48f24c4d IM |
6872 | static int |
6873 | sd_parent_degenerate(struct sched_domain *sd, struct sched_domain *parent) | |
245af2c7 SS |
6874 | { |
6875 | unsigned long cflags = sd->flags, pflags = parent->flags; | |
6876 | ||
6877 | if (sd_degenerate(parent)) | |
6878 | return 1; | |
6879 | ||
758b2cdc | 6880 | if (!cpumask_equal(sched_domain_span(sd), sched_domain_span(parent))) |
245af2c7 SS |
6881 | return 0; |
6882 | ||
245af2c7 SS |
6883 | /* Flags needing groups don't count if only 1 group in parent */ |
6884 | if (parent->groups == parent->groups->next) { | |
6885 | pflags &= ~(SD_LOAD_BALANCE | | |
6886 | SD_BALANCE_NEWIDLE | | |
6887 | SD_BALANCE_FORK | | |
89c4710e SS |
6888 | SD_BALANCE_EXEC | |
6889 | SD_SHARE_CPUPOWER | | |
6890 | SD_SHARE_PKG_RESOURCES); | |
5436499e KC |
6891 | if (nr_node_ids == 1) |
6892 | pflags &= ~SD_SERIALIZE; | |
245af2c7 SS |
6893 | } |
6894 | if (~cflags & pflags) | |
6895 | return 0; | |
6896 | ||
6897 | return 1; | |
6898 | } | |
6899 | ||
dce840a0 | 6900 | static void free_rootdomain(struct rcu_head *rcu) |
c6c4927b | 6901 | { |
dce840a0 | 6902 | struct root_domain *rd = container_of(rcu, struct root_domain, rcu); |
047106ad | 6903 | |
68e74568 | 6904 | cpupri_cleanup(&rd->cpupri); |
c6c4927b RR |
6905 | free_cpumask_var(rd->rto_mask); |
6906 | free_cpumask_var(rd->online); | |
6907 | free_cpumask_var(rd->span); | |
6908 | kfree(rd); | |
6909 | } | |
6910 | ||
57d885fe GH |
6911 | static void rq_attach_root(struct rq *rq, struct root_domain *rd) |
6912 | { | |
a0490fa3 | 6913 | struct root_domain *old_rd = NULL; |
57d885fe | 6914 | unsigned long flags; |
57d885fe | 6915 | |
05fa785c | 6916 | raw_spin_lock_irqsave(&rq->lock, flags); |
57d885fe GH |
6917 | |
6918 | if (rq->rd) { | |
a0490fa3 | 6919 | old_rd = rq->rd; |
57d885fe | 6920 | |
c6c4927b | 6921 | if (cpumask_test_cpu(rq->cpu, old_rd->online)) |
1f11eb6a | 6922 | set_rq_offline(rq); |
57d885fe | 6923 | |
c6c4927b | 6924 | cpumask_clear_cpu(rq->cpu, old_rd->span); |
dc938520 | 6925 | |
a0490fa3 IM |
6926 | /* |
6927 | * If we dont want to free the old_rt yet then | |
6928 | * set old_rd to NULL to skip the freeing later | |
6929 | * in this function: | |
6930 | */ | |
6931 | if (!atomic_dec_and_test(&old_rd->refcount)) | |
6932 | old_rd = NULL; | |
57d885fe GH |
6933 | } |
6934 | ||
6935 | atomic_inc(&rd->refcount); | |
6936 | rq->rd = rd; | |
6937 | ||
c6c4927b | 6938 | cpumask_set_cpu(rq->cpu, rd->span); |
00aec93d | 6939 | if (cpumask_test_cpu(rq->cpu, cpu_active_mask)) |
1f11eb6a | 6940 | set_rq_online(rq); |
57d885fe | 6941 | |
05fa785c | 6942 | raw_spin_unlock_irqrestore(&rq->lock, flags); |
a0490fa3 IM |
6943 | |
6944 | if (old_rd) | |
dce840a0 | 6945 | call_rcu_sched(&old_rd->rcu, free_rootdomain); |
57d885fe GH |
6946 | } |
6947 | ||
68c38fc3 | 6948 | static int init_rootdomain(struct root_domain *rd) |
57d885fe GH |
6949 | { |
6950 | memset(rd, 0, sizeof(*rd)); | |
6951 | ||
68c38fc3 | 6952 | if (!alloc_cpumask_var(&rd->span, GFP_KERNEL)) |
0c910d28 | 6953 | goto out; |
68c38fc3 | 6954 | if (!alloc_cpumask_var(&rd->online, GFP_KERNEL)) |
c6c4927b | 6955 | goto free_span; |
68c38fc3 | 6956 | if (!alloc_cpumask_var(&rd->rto_mask, GFP_KERNEL)) |
c6c4927b | 6957 | goto free_online; |
6e0534f2 | 6958 | |
68c38fc3 | 6959 | if (cpupri_init(&rd->cpupri) != 0) |
68e74568 | 6960 | goto free_rto_mask; |
c6c4927b | 6961 | return 0; |
6e0534f2 | 6962 | |
68e74568 RR |
6963 | free_rto_mask: |
6964 | free_cpumask_var(rd->rto_mask); | |
c6c4927b RR |
6965 | free_online: |
6966 | free_cpumask_var(rd->online); | |
6967 | free_span: | |
6968 | free_cpumask_var(rd->span); | |
0c910d28 | 6969 | out: |
c6c4927b | 6970 | return -ENOMEM; |
57d885fe GH |
6971 | } |
6972 | ||
6973 | static void init_defrootdomain(void) | |
6974 | { | |
68c38fc3 | 6975 | init_rootdomain(&def_root_domain); |
c6c4927b | 6976 | |
57d885fe GH |
6977 | atomic_set(&def_root_domain.refcount, 1); |
6978 | } | |
6979 | ||
dc938520 | 6980 | static struct root_domain *alloc_rootdomain(void) |
57d885fe GH |
6981 | { |
6982 | struct root_domain *rd; | |
6983 | ||
6984 | rd = kmalloc(sizeof(*rd), GFP_KERNEL); | |
6985 | if (!rd) | |
6986 | return NULL; | |
6987 | ||
68c38fc3 | 6988 | if (init_rootdomain(rd) != 0) { |
c6c4927b RR |
6989 | kfree(rd); |
6990 | return NULL; | |
6991 | } | |
57d885fe GH |
6992 | |
6993 | return rd; | |
6994 | } | |
6995 | ||
e3589f6c PZ |
6996 | static void free_sched_groups(struct sched_group *sg, int free_sgp) |
6997 | { | |
6998 | struct sched_group *tmp, *first; | |
6999 | ||
7000 | if (!sg) | |
7001 | return; | |
7002 | ||
7003 | first = sg; | |
7004 | do { | |
7005 | tmp = sg->next; | |
7006 | ||
7007 | if (free_sgp && atomic_dec_and_test(&sg->sgp->ref)) | |
7008 | kfree(sg->sgp); | |
7009 | ||
7010 | kfree(sg); | |
7011 | sg = tmp; | |
7012 | } while (sg != first); | |
7013 | } | |
7014 | ||
dce840a0 PZ |
7015 | static void free_sched_domain(struct rcu_head *rcu) |
7016 | { | |
7017 | struct sched_domain *sd = container_of(rcu, struct sched_domain, rcu); | |
e3589f6c PZ |
7018 | |
7019 | /* | |
7020 | * If its an overlapping domain it has private groups, iterate and | |
7021 | * nuke them all. | |
7022 | */ | |
7023 | if (sd->flags & SD_OVERLAP) { | |
7024 | free_sched_groups(sd->groups, 1); | |
7025 | } else if (atomic_dec_and_test(&sd->groups->ref)) { | |
9c3f75cb | 7026 | kfree(sd->groups->sgp); |
dce840a0 | 7027 | kfree(sd->groups); |
9c3f75cb | 7028 | } |
dce840a0 PZ |
7029 | kfree(sd); |
7030 | } | |
7031 | ||
7032 | static void destroy_sched_domain(struct sched_domain *sd, int cpu) | |
7033 | { | |
7034 | call_rcu(&sd->rcu, free_sched_domain); | |
7035 | } | |
7036 | ||
7037 | static void destroy_sched_domains(struct sched_domain *sd, int cpu) | |
7038 | { | |
7039 | for (; sd; sd = sd->parent) | |
7040 | destroy_sched_domain(sd, cpu); | |
7041 | } | |
7042 | ||
1da177e4 | 7043 | /* |
0eab9146 | 7044 | * Attach the domain 'sd' to 'cpu' as its base domain. Callers must |
1da177e4 LT |
7045 | * hold the hotplug lock. |
7046 | */ | |
0eab9146 IM |
7047 | static void |
7048 | cpu_attach_domain(struct sched_domain *sd, struct root_domain *rd, int cpu) | |
1da177e4 | 7049 | { |
70b97a7f | 7050 | struct rq *rq = cpu_rq(cpu); |
245af2c7 SS |
7051 | struct sched_domain *tmp; |
7052 | ||
7053 | /* Remove the sched domains which do not contribute to scheduling. */ | |
f29c9b1c | 7054 | for (tmp = sd; tmp; ) { |
245af2c7 SS |
7055 | struct sched_domain *parent = tmp->parent; |
7056 | if (!parent) | |
7057 | break; | |
f29c9b1c | 7058 | |
1a848870 | 7059 | if (sd_parent_degenerate(tmp, parent)) { |
245af2c7 | 7060 | tmp->parent = parent->parent; |
1a848870 SS |
7061 | if (parent->parent) |
7062 | parent->parent->child = tmp; | |
dce840a0 | 7063 | destroy_sched_domain(parent, cpu); |
f29c9b1c LZ |
7064 | } else |
7065 | tmp = tmp->parent; | |
245af2c7 SS |
7066 | } |
7067 | ||
1a848870 | 7068 | if (sd && sd_degenerate(sd)) { |
dce840a0 | 7069 | tmp = sd; |
245af2c7 | 7070 | sd = sd->parent; |
dce840a0 | 7071 | destroy_sched_domain(tmp, cpu); |
1a848870 SS |
7072 | if (sd) |
7073 | sd->child = NULL; | |
7074 | } | |
1da177e4 | 7075 | |
4cb98839 | 7076 | sched_domain_debug(sd, cpu); |
1da177e4 | 7077 | |
57d885fe | 7078 | rq_attach_root(rq, rd); |
dce840a0 | 7079 | tmp = rq->sd; |
674311d5 | 7080 | rcu_assign_pointer(rq->sd, sd); |
dce840a0 | 7081 | destroy_sched_domains(tmp, cpu); |
1da177e4 LT |
7082 | } |
7083 | ||
7084 | /* cpus with isolated domains */ | |
dcc30a35 | 7085 | static cpumask_var_t cpu_isolated_map; |
1da177e4 LT |
7086 | |
7087 | /* Setup the mask of cpus configured for isolated domains */ | |
7088 | static int __init isolated_cpu_setup(char *str) | |
7089 | { | |
bdddd296 | 7090 | alloc_bootmem_cpumask_var(&cpu_isolated_map); |
968ea6d8 | 7091 | cpulist_parse(str, cpu_isolated_map); |
1da177e4 LT |
7092 | return 1; |
7093 | } | |
7094 | ||
8927f494 | 7095 | __setup("isolcpus=", isolated_cpu_setup); |
1da177e4 | 7096 | |
9c1cfda2 | 7097 | #define SD_NODES_PER_DOMAIN 16 |
1da177e4 | 7098 | |
9c1cfda2 | 7099 | #ifdef CONFIG_NUMA |
198e2f18 | 7100 | |
9c1cfda2 JH |
7101 | /** |
7102 | * find_next_best_node - find the next node to include in a sched_domain | |
7103 | * @node: node whose sched_domain we're building | |
7104 | * @used_nodes: nodes already in the sched_domain | |
7105 | * | |
41a2d6cf | 7106 | * Find the next node to include in a given scheduling domain. Simply |
9c1cfda2 JH |
7107 | * finds the closest node not already in the @used_nodes map. |
7108 | * | |
7109 | * Should use nodemask_t. | |
7110 | */ | |
c5f59f08 | 7111 | static int find_next_best_node(int node, nodemask_t *used_nodes) |
9c1cfda2 | 7112 | { |
7142d17e | 7113 | int i, n, val, min_val, best_node = -1; |
9c1cfda2 JH |
7114 | |
7115 | min_val = INT_MAX; | |
7116 | ||
076ac2af | 7117 | for (i = 0; i < nr_node_ids; i++) { |
9c1cfda2 | 7118 | /* Start at @node */ |
076ac2af | 7119 | n = (node + i) % nr_node_ids; |
9c1cfda2 JH |
7120 | |
7121 | if (!nr_cpus_node(n)) | |
7122 | continue; | |
7123 | ||
7124 | /* Skip already used nodes */ | |
c5f59f08 | 7125 | if (node_isset(n, *used_nodes)) |
9c1cfda2 JH |
7126 | continue; |
7127 | ||
7128 | /* Simple min distance search */ | |
7129 | val = node_distance(node, n); | |
7130 | ||
7131 | if (val < min_val) { | |
7132 | min_val = val; | |
7133 | best_node = n; | |
7134 | } | |
7135 | } | |
7136 | ||
7142d17e HD |
7137 | if (best_node != -1) |
7138 | node_set(best_node, *used_nodes); | |
9c1cfda2 JH |
7139 | return best_node; |
7140 | } | |
7141 | ||
7142 | /** | |
7143 | * sched_domain_node_span - get a cpumask for a node's sched_domain | |
7144 | * @node: node whose cpumask we're constructing | |
73486722 | 7145 | * @span: resulting cpumask |
9c1cfda2 | 7146 | * |
41a2d6cf | 7147 | * Given a node, construct a good cpumask for its sched_domain to span. It |
9c1cfda2 JH |
7148 | * should be one that prevents unnecessary balancing, but also spreads tasks |
7149 | * out optimally. | |
7150 | */ | |
96f874e2 | 7151 | static void sched_domain_node_span(int node, struct cpumask *span) |
9c1cfda2 | 7152 | { |
c5f59f08 | 7153 | nodemask_t used_nodes; |
48f24c4d | 7154 | int i; |
9c1cfda2 | 7155 | |
6ca09dfc | 7156 | cpumask_clear(span); |
c5f59f08 | 7157 | nodes_clear(used_nodes); |
9c1cfda2 | 7158 | |
6ca09dfc | 7159 | cpumask_or(span, span, cpumask_of_node(node)); |
c5f59f08 | 7160 | node_set(node, used_nodes); |
9c1cfda2 JH |
7161 | |
7162 | for (i = 1; i < SD_NODES_PER_DOMAIN; i++) { | |
c5f59f08 | 7163 | int next_node = find_next_best_node(node, &used_nodes); |
7142d17e HD |
7164 | if (next_node < 0) |
7165 | break; | |
6ca09dfc | 7166 | cpumask_or(span, span, cpumask_of_node(next_node)); |
9c1cfda2 | 7167 | } |
9c1cfda2 | 7168 | } |
d3081f52 PZ |
7169 | |
7170 | static const struct cpumask *cpu_node_mask(int cpu) | |
7171 | { | |
7172 | lockdep_assert_held(&sched_domains_mutex); | |
7173 | ||
7174 | sched_domain_node_span(cpu_to_node(cpu), sched_domains_tmpmask); | |
7175 | ||
7176 | return sched_domains_tmpmask; | |
7177 | } | |
2c402dc3 PZ |
7178 | |
7179 | static const struct cpumask *cpu_allnodes_mask(int cpu) | |
7180 | { | |
7181 | return cpu_possible_mask; | |
7182 | } | |
6d6bc0ad | 7183 | #endif /* CONFIG_NUMA */ |
9c1cfda2 | 7184 | |
d3081f52 PZ |
7185 | static const struct cpumask *cpu_cpu_mask(int cpu) |
7186 | { | |
7187 | return cpumask_of_node(cpu_to_node(cpu)); | |
7188 | } | |
7189 | ||
5c45bf27 | 7190 | int sched_smt_power_savings = 0, sched_mc_power_savings = 0; |
48f24c4d | 7191 | |
dce840a0 PZ |
7192 | struct sd_data { |
7193 | struct sched_domain **__percpu sd; | |
7194 | struct sched_group **__percpu sg; | |
9c3f75cb | 7195 | struct sched_group_power **__percpu sgp; |
dce840a0 PZ |
7196 | }; |
7197 | ||
49a02c51 | 7198 | struct s_data { |
21d42ccf | 7199 | struct sched_domain ** __percpu sd; |
49a02c51 AH |
7200 | struct root_domain *rd; |
7201 | }; | |
7202 | ||
2109b99e | 7203 | enum s_alloc { |
2109b99e | 7204 | sa_rootdomain, |
21d42ccf | 7205 | sa_sd, |
dce840a0 | 7206 | sa_sd_storage, |
2109b99e AH |
7207 | sa_none, |
7208 | }; | |
7209 | ||
54ab4ff4 PZ |
7210 | struct sched_domain_topology_level; |
7211 | ||
7212 | typedef struct sched_domain *(*sched_domain_init_f)(struct sched_domain_topology_level *tl, int cpu); | |
eb7a74e6 PZ |
7213 | typedef const struct cpumask *(*sched_domain_mask_f)(int cpu); |
7214 | ||
e3589f6c PZ |
7215 | #define SDTL_OVERLAP 0x01 |
7216 | ||
eb7a74e6 | 7217 | struct sched_domain_topology_level { |
2c402dc3 PZ |
7218 | sched_domain_init_f init; |
7219 | sched_domain_mask_f mask; | |
e3589f6c | 7220 | int flags; |
54ab4ff4 | 7221 | struct sd_data data; |
eb7a74e6 PZ |
7222 | }; |
7223 | ||
e3589f6c PZ |
7224 | static int |
7225 | build_overlap_sched_groups(struct sched_domain *sd, int cpu) | |
7226 | { | |
7227 | struct sched_group *first = NULL, *last = NULL, *groups = NULL, *sg; | |
7228 | const struct cpumask *span = sched_domain_span(sd); | |
7229 | struct cpumask *covered = sched_domains_tmpmask; | |
7230 | struct sd_data *sdd = sd->private; | |
7231 | struct sched_domain *child; | |
7232 | int i; | |
7233 | ||
7234 | cpumask_clear(covered); | |
7235 | ||
7236 | for_each_cpu(i, span) { | |
7237 | struct cpumask *sg_span; | |
7238 | ||
7239 | if (cpumask_test_cpu(i, covered)) | |
7240 | continue; | |
7241 | ||
7242 | sg = kzalloc_node(sizeof(struct sched_group) + cpumask_size(), | |
7243 | GFP_KERNEL, cpu_to_node(i)); | |
7244 | ||
7245 | if (!sg) | |
7246 | goto fail; | |
7247 | ||
7248 | sg_span = sched_group_cpus(sg); | |
7249 | ||
7250 | child = *per_cpu_ptr(sdd->sd, i); | |
7251 | if (child->child) { | |
7252 | child = child->child; | |
7253 | cpumask_copy(sg_span, sched_domain_span(child)); | |
7254 | } else | |
7255 | cpumask_set_cpu(i, sg_span); | |
7256 | ||
7257 | cpumask_or(covered, covered, sg_span); | |
7258 | ||
7259 | sg->sgp = *per_cpu_ptr(sdd->sgp, cpumask_first(sg_span)); | |
7260 | atomic_inc(&sg->sgp->ref); | |
7261 | ||
7262 | if (cpumask_test_cpu(cpu, sg_span)) | |
7263 | groups = sg; | |
7264 | ||
7265 | if (!first) | |
7266 | first = sg; | |
7267 | if (last) | |
7268 | last->next = sg; | |
7269 | last = sg; | |
7270 | last->next = first; | |
7271 | } | |
7272 | sd->groups = groups; | |
7273 | ||
7274 | return 0; | |
7275 | ||
7276 | fail: | |
7277 | free_sched_groups(first, 0); | |
7278 | ||
7279 | return -ENOMEM; | |
7280 | } | |
7281 | ||
dce840a0 | 7282 | static int get_group(int cpu, struct sd_data *sdd, struct sched_group **sg) |
1da177e4 | 7283 | { |
dce840a0 PZ |
7284 | struct sched_domain *sd = *per_cpu_ptr(sdd->sd, cpu); |
7285 | struct sched_domain *child = sd->child; | |
1da177e4 | 7286 | |
dce840a0 PZ |
7287 | if (child) |
7288 | cpu = cpumask_first(sched_domain_span(child)); | |
1e9f28fa | 7289 | |
9c3f75cb | 7290 | if (sg) { |
dce840a0 | 7291 | *sg = *per_cpu_ptr(sdd->sg, cpu); |
9c3f75cb | 7292 | (*sg)->sgp = *per_cpu_ptr(sdd->sgp, cpu); |
e3589f6c | 7293 | atomic_set(&(*sg)->sgp->ref, 1); /* for claim_allocations */ |
9c3f75cb | 7294 | } |
dce840a0 PZ |
7295 | |
7296 | return cpu; | |
1e9f28fa | 7297 | } |
1e9f28fa | 7298 | |
01a08546 | 7299 | /* |
dce840a0 PZ |
7300 | * build_sched_groups will build a circular linked list of the groups |
7301 | * covered by the given span, and will set each group's ->cpumask correctly, | |
7302 | * and ->cpu_power to 0. | |
e3589f6c PZ |
7303 | * |
7304 | * Assumes the sched_domain tree is fully constructed | |
01a08546 | 7305 | */ |
e3589f6c PZ |
7306 | static int |
7307 | build_sched_groups(struct sched_domain *sd, int cpu) | |
1da177e4 | 7308 | { |
dce840a0 PZ |
7309 | struct sched_group *first = NULL, *last = NULL; |
7310 | struct sd_data *sdd = sd->private; | |
7311 | const struct cpumask *span = sched_domain_span(sd); | |
f96225fd | 7312 | struct cpumask *covered; |
dce840a0 | 7313 | int i; |
9c1cfda2 | 7314 | |
e3589f6c PZ |
7315 | get_group(cpu, sdd, &sd->groups); |
7316 | atomic_inc(&sd->groups->ref); | |
7317 | ||
7318 | if (cpu != cpumask_first(sched_domain_span(sd))) | |
7319 | return 0; | |
7320 | ||
f96225fd PZ |
7321 | lockdep_assert_held(&sched_domains_mutex); |
7322 | covered = sched_domains_tmpmask; | |
7323 | ||
dce840a0 | 7324 | cpumask_clear(covered); |
6711cab4 | 7325 | |
dce840a0 PZ |
7326 | for_each_cpu(i, span) { |
7327 | struct sched_group *sg; | |
7328 | int group = get_group(i, sdd, &sg); | |
7329 | int j; | |
6711cab4 | 7330 | |
dce840a0 PZ |
7331 | if (cpumask_test_cpu(i, covered)) |
7332 | continue; | |
6711cab4 | 7333 | |
dce840a0 | 7334 | cpumask_clear(sched_group_cpus(sg)); |
9c3f75cb | 7335 | sg->sgp->power = 0; |
0601a88d | 7336 | |
dce840a0 PZ |
7337 | for_each_cpu(j, span) { |
7338 | if (get_group(j, sdd, NULL) != group) | |
7339 | continue; | |
0601a88d | 7340 | |
dce840a0 PZ |
7341 | cpumask_set_cpu(j, covered); |
7342 | cpumask_set_cpu(j, sched_group_cpus(sg)); | |
7343 | } | |
0601a88d | 7344 | |
dce840a0 PZ |
7345 | if (!first) |
7346 | first = sg; | |
7347 | if (last) | |
7348 | last->next = sg; | |
7349 | last = sg; | |
7350 | } | |
7351 | last->next = first; | |
e3589f6c PZ |
7352 | |
7353 | return 0; | |
0601a88d | 7354 | } |
51888ca2 | 7355 | |
89c4710e SS |
7356 | /* |
7357 | * Initialize sched groups cpu_power. | |
7358 | * | |
7359 | * cpu_power indicates the capacity of sched group, which is used while | |
7360 | * distributing the load between different sched groups in a sched domain. | |
7361 | * Typically cpu_power for all the groups in a sched domain will be same unless | |
7362 | * there are asymmetries in the topology. If there are asymmetries, group | |
7363 | * having more cpu_power will pickup more load compared to the group having | |
7364 | * less cpu_power. | |
89c4710e SS |
7365 | */ |
7366 | static void init_sched_groups_power(int cpu, struct sched_domain *sd) | |
7367 | { | |
e3589f6c | 7368 | struct sched_group *sg = sd->groups; |
89c4710e | 7369 | |
e3589f6c PZ |
7370 | WARN_ON(!sd || !sg); |
7371 | ||
7372 | do { | |
7373 | sg->group_weight = cpumask_weight(sched_group_cpus(sg)); | |
7374 | sg = sg->next; | |
7375 | } while (sg != sd->groups); | |
89c4710e | 7376 | |
e3589f6c PZ |
7377 | if (cpu != group_first_cpu(sg)) |
7378 | return; | |
aae6d3dd | 7379 | |
d274cb30 | 7380 | update_group_power(sd, cpu); |
89c4710e SS |
7381 | } |
7382 | ||
7c16ec58 MT |
7383 | /* |
7384 | * Initializers for schedule domains | |
7385 | * Non-inlined to reduce accumulated stack pressure in build_sched_domains() | |
7386 | */ | |
7387 | ||
a5d8c348 IM |
7388 | #ifdef CONFIG_SCHED_DEBUG |
7389 | # define SD_INIT_NAME(sd, type) sd->name = #type | |
7390 | #else | |
7391 | # define SD_INIT_NAME(sd, type) do { } while (0) | |
7392 | #endif | |
7393 | ||
54ab4ff4 PZ |
7394 | #define SD_INIT_FUNC(type) \ |
7395 | static noinline struct sched_domain * \ | |
7396 | sd_init_##type(struct sched_domain_topology_level *tl, int cpu) \ | |
7397 | { \ | |
7398 | struct sched_domain *sd = *per_cpu_ptr(tl->data.sd, cpu); \ | |
7399 | *sd = SD_##type##_INIT; \ | |
54ab4ff4 PZ |
7400 | SD_INIT_NAME(sd, type); \ |
7401 | sd->private = &tl->data; \ | |
7402 | return sd; \ | |
7c16ec58 MT |
7403 | } |
7404 | ||
7405 | SD_INIT_FUNC(CPU) | |
7406 | #ifdef CONFIG_NUMA | |
7407 | SD_INIT_FUNC(ALLNODES) | |
7408 | SD_INIT_FUNC(NODE) | |
7409 | #endif | |
7410 | #ifdef CONFIG_SCHED_SMT | |
7411 | SD_INIT_FUNC(SIBLING) | |
7412 | #endif | |
7413 | #ifdef CONFIG_SCHED_MC | |
7414 | SD_INIT_FUNC(MC) | |
7415 | #endif | |
01a08546 HC |
7416 | #ifdef CONFIG_SCHED_BOOK |
7417 | SD_INIT_FUNC(BOOK) | |
7418 | #endif | |
7c16ec58 | 7419 | |
1d3504fc | 7420 | static int default_relax_domain_level = -1; |
60495e77 | 7421 | int sched_domain_level_max; |
1d3504fc HS |
7422 | |
7423 | static int __init setup_relax_domain_level(char *str) | |
7424 | { | |
30e0e178 LZ |
7425 | unsigned long val; |
7426 | ||
7427 | val = simple_strtoul(str, NULL, 0); | |
60495e77 | 7428 | if (val < sched_domain_level_max) |
30e0e178 LZ |
7429 | default_relax_domain_level = val; |
7430 | ||
1d3504fc HS |
7431 | return 1; |
7432 | } | |
7433 | __setup("relax_domain_level=", setup_relax_domain_level); | |
7434 | ||
7435 | static void set_domain_attribute(struct sched_domain *sd, | |
7436 | struct sched_domain_attr *attr) | |
7437 | { | |
7438 | int request; | |
7439 | ||
7440 | if (!attr || attr->relax_domain_level < 0) { | |
7441 | if (default_relax_domain_level < 0) | |
7442 | return; | |
7443 | else | |
7444 | request = default_relax_domain_level; | |
7445 | } else | |
7446 | request = attr->relax_domain_level; | |
7447 | if (request < sd->level) { | |
7448 | /* turn off idle balance on this domain */ | |
c88d5910 | 7449 | sd->flags &= ~(SD_BALANCE_WAKE|SD_BALANCE_NEWIDLE); |
1d3504fc HS |
7450 | } else { |
7451 | /* turn on idle balance on this domain */ | |
c88d5910 | 7452 | sd->flags |= (SD_BALANCE_WAKE|SD_BALANCE_NEWIDLE); |
1d3504fc HS |
7453 | } |
7454 | } | |
7455 | ||
54ab4ff4 PZ |
7456 | static void __sdt_free(const struct cpumask *cpu_map); |
7457 | static int __sdt_alloc(const struct cpumask *cpu_map); | |
7458 | ||
2109b99e AH |
7459 | static void __free_domain_allocs(struct s_data *d, enum s_alloc what, |
7460 | const struct cpumask *cpu_map) | |
7461 | { | |
7462 | switch (what) { | |
2109b99e | 7463 | case sa_rootdomain: |
822ff793 PZ |
7464 | if (!atomic_read(&d->rd->refcount)) |
7465 | free_rootdomain(&d->rd->rcu); /* fall through */ | |
21d42ccf PZ |
7466 | case sa_sd: |
7467 | free_percpu(d->sd); /* fall through */ | |
dce840a0 | 7468 | case sa_sd_storage: |
54ab4ff4 | 7469 | __sdt_free(cpu_map); /* fall through */ |
2109b99e AH |
7470 | case sa_none: |
7471 | break; | |
7472 | } | |
7473 | } | |
3404c8d9 | 7474 | |
2109b99e AH |
7475 | static enum s_alloc __visit_domain_allocation_hell(struct s_data *d, |
7476 | const struct cpumask *cpu_map) | |
7477 | { | |
dce840a0 PZ |
7478 | memset(d, 0, sizeof(*d)); |
7479 | ||
54ab4ff4 PZ |
7480 | if (__sdt_alloc(cpu_map)) |
7481 | return sa_sd_storage; | |
dce840a0 PZ |
7482 | d->sd = alloc_percpu(struct sched_domain *); |
7483 | if (!d->sd) | |
7484 | return sa_sd_storage; | |
2109b99e | 7485 | d->rd = alloc_rootdomain(); |
dce840a0 | 7486 | if (!d->rd) |
21d42ccf | 7487 | return sa_sd; |
2109b99e AH |
7488 | return sa_rootdomain; |
7489 | } | |
57d885fe | 7490 | |
dce840a0 PZ |
7491 | /* |
7492 | * NULL the sd_data elements we've used to build the sched_domain and | |
7493 | * sched_group structure so that the subsequent __free_domain_allocs() | |
7494 | * will not free the data we're using. | |
7495 | */ | |
7496 | static void claim_allocations(int cpu, struct sched_domain *sd) | |
7497 | { | |
7498 | struct sd_data *sdd = sd->private; | |
dce840a0 PZ |
7499 | |
7500 | WARN_ON_ONCE(*per_cpu_ptr(sdd->sd, cpu) != sd); | |
7501 | *per_cpu_ptr(sdd->sd, cpu) = NULL; | |
7502 | ||
e3589f6c | 7503 | if (atomic_read(&(*per_cpu_ptr(sdd->sg, cpu))->ref)) |
dce840a0 | 7504 | *per_cpu_ptr(sdd->sg, cpu) = NULL; |
e3589f6c PZ |
7505 | |
7506 | if (atomic_read(&(*per_cpu_ptr(sdd->sgp, cpu))->ref)) | |
9c3f75cb | 7507 | *per_cpu_ptr(sdd->sgp, cpu) = NULL; |
dce840a0 PZ |
7508 | } |
7509 | ||
2c402dc3 PZ |
7510 | #ifdef CONFIG_SCHED_SMT |
7511 | static const struct cpumask *cpu_smt_mask(int cpu) | |
7f4588f3 | 7512 | { |
2c402dc3 | 7513 | return topology_thread_cpumask(cpu); |
3bd65a80 | 7514 | } |
2c402dc3 | 7515 | #endif |
7f4588f3 | 7516 | |
d069b916 PZ |
7517 | /* |
7518 | * Topology list, bottom-up. | |
7519 | */ | |
2c402dc3 | 7520 | static struct sched_domain_topology_level default_topology[] = { |
d069b916 PZ |
7521 | #ifdef CONFIG_SCHED_SMT |
7522 | { sd_init_SIBLING, cpu_smt_mask, }, | |
01a08546 | 7523 | #endif |
1e9f28fa | 7524 | #ifdef CONFIG_SCHED_MC |
2c402dc3 | 7525 | { sd_init_MC, cpu_coregroup_mask, }, |
1e9f28fa | 7526 | #endif |
d069b916 PZ |
7527 | #ifdef CONFIG_SCHED_BOOK |
7528 | { sd_init_BOOK, cpu_book_mask, }, | |
7529 | #endif | |
7530 | { sd_init_CPU, cpu_cpu_mask, }, | |
7531 | #ifdef CONFIG_NUMA | |
e3589f6c | 7532 | { sd_init_NODE, cpu_node_mask, SDTL_OVERLAP, }, |
d069b916 | 7533 | { sd_init_ALLNODES, cpu_allnodes_mask, }, |
1da177e4 | 7534 | #endif |
eb7a74e6 PZ |
7535 | { NULL, }, |
7536 | }; | |
7537 | ||
7538 | static struct sched_domain_topology_level *sched_domain_topology = default_topology; | |
7539 | ||
54ab4ff4 PZ |
7540 | static int __sdt_alloc(const struct cpumask *cpu_map) |
7541 | { | |
7542 | struct sched_domain_topology_level *tl; | |
7543 | int j; | |
7544 | ||
7545 | for (tl = sched_domain_topology; tl->init; tl++) { | |
7546 | struct sd_data *sdd = &tl->data; | |
7547 | ||
7548 | sdd->sd = alloc_percpu(struct sched_domain *); | |
7549 | if (!sdd->sd) | |
7550 | return -ENOMEM; | |
7551 | ||
7552 | sdd->sg = alloc_percpu(struct sched_group *); | |
7553 | if (!sdd->sg) | |
7554 | return -ENOMEM; | |
7555 | ||
9c3f75cb PZ |
7556 | sdd->sgp = alloc_percpu(struct sched_group_power *); |
7557 | if (!sdd->sgp) | |
7558 | return -ENOMEM; | |
7559 | ||
54ab4ff4 PZ |
7560 | for_each_cpu(j, cpu_map) { |
7561 | struct sched_domain *sd; | |
7562 | struct sched_group *sg; | |
9c3f75cb | 7563 | struct sched_group_power *sgp; |
54ab4ff4 PZ |
7564 | |
7565 | sd = kzalloc_node(sizeof(struct sched_domain) + cpumask_size(), | |
7566 | GFP_KERNEL, cpu_to_node(j)); | |
7567 | if (!sd) | |
7568 | return -ENOMEM; | |
7569 | ||
7570 | *per_cpu_ptr(sdd->sd, j) = sd; | |
7571 | ||
7572 | sg = kzalloc_node(sizeof(struct sched_group) + cpumask_size(), | |
7573 | GFP_KERNEL, cpu_to_node(j)); | |
7574 | if (!sg) | |
7575 | return -ENOMEM; | |
7576 | ||
7577 | *per_cpu_ptr(sdd->sg, j) = sg; | |
9c3f75cb PZ |
7578 | |
7579 | sgp = kzalloc_node(sizeof(struct sched_group_power), | |
7580 | GFP_KERNEL, cpu_to_node(j)); | |
7581 | if (!sgp) | |
7582 | return -ENOMEM; | |
7583 | ||
7584 | *per_cpu_ptr(sdd->sgp, j) = sgp; | |
54ab4ff4 PZ |
7585 | } |
7586 | } | |
7587 | ||
7588 | return 0; | |
7589 | } | |
7590 | ||
7591 | static void __sdt_free(const struct cpumask *cpu_map) | |
7592 | { | |
7593 | struct sched_domain_topology_level *tl; | |
7594 | int j; | |
7595 | ||
7596 | for (tl = sched_domain_topology; tl->init; tl++) { | |
7597 | struct sd_data *sdd = &tl->data; | |
7598 | ||
7599 | for_each_cpu(j, cpu_map) { | |
e3589f6c PZ |
7600 | struct sched_domain *sd = *per_cpu_ptr(sdd->sd, j); |
7601 | if (sd && (sd->flags & SD_OVERLAP)) | |
7602 | free_sched_groups(sd->groups, 0); | |
feff8fa0 | 7603 | kfree(*per_cpu_ptr(sdd->sd, j)); |
54ab4ff4 | 7604 | kfree(*per_cpu_ptr(sdd->sg, j)); |
9c3f75cb | 7605 | kfree(*per_cpu_ptr(sdd->sgp, j)); |
54ab4ff4 PZ |
7606 | } |
7607 | free_percpu(sdd->sd); | |
7608 | free_percpu(sdd->sg); | |
9c3f75cb | 7609 | free_percpu(sdd->sgp); |
54ab4ff4 PZ |
7610 | } |
7611 | } | |
7612 | ||
2c402dc3 PZ |
7613 | struct sched_domain *build_sched_domain(struct sched_domain_topology_level *tl, |
7614 | struct s_data *d, const struct cpumask *cpu_map, | |
d069b916 | 7615 | struct sched_domain_attr *attr, struct sched_domain *child, |
2c402dc3 PZ |
7616 | int cpu) |
7617 | { | |
54ab4ff4 | 7618 | struct sched_domain *sd = tl->init(tl, cpu); |
2c402dc3 | 7619 | if (!sd) |
d069b916 | 7620 | return child; |
2c402dc3 PZ |
7621 | |
7622 | set_domain_attribute(sd, attr); | |
7623 | cpumask_and(sched_domain_span(sd), cpu_map, tl->mask(cpu)); | |
60495e77 PZ |
7624 | if (child) { |
7625 | sd->level = child->level + 1; | |
7626 | sched_domain_level_max = max(sched_domain_level_max, sd->level); | |
d069b916 | 7627 | child->parent = sd; |
60495e77 | 7628 | } |
d069b916 | 7629 | sd->child = child; |
2c402dc3 PZ |
7630 | |
7631 | return sd; | |
7632 | } | |
7633 | ||
2109b99e AH |
7634 | /* |
7635 | * Build sched domains for a given set of cpus and attach the sched domains | |
7636 | * to the individual cpus | |
7637 | */ | |
dce840a0 PZ |
7638 | static int build_sched_domains(const struct cpumask *cpu_map, |
7639 | struct sched_domain_attr *attr) | |
2109b99e AH |
7640 | { |
7641 | enum s_alloc alloc_state = sa_none; | |
dce840a0 | 7642 | struct sched_domain *sd; |
2109b99e | 7643 | struct s_data d; |
822ff793 | 7644 | int i, ret = -ENOMEM; |
9c1cfda2 | 7645 | |
2109b99e AH |
7646 | alloc_state = __visit_domain_allocation_hell(&d, cpu_map); |
7647 | if (alloc_state != sa_rootdomain) | |
7648 | goto error; | |
9c1cfda2 | 7649 | |
dce840a0 | 7650 | /* Set up domains for cpus specified by the cpu_map. */ |
abcd083a | 7651 | for_each_cpu(i, cpu_map) { |
eb7a74e6 PZ |
7652 | struct sched_domain_topology_level *tl; |
7653 | ||
3bd65a80 | 7654 | sd = NULL; |
e3589f6c | 7655 | for (tl = sched_domain_topology; tl->init; tl++) { |
2c402dc3 | 7656 | sd = build_sched_domain(tl, &d, cpu_map, attr, sd, i); |
e3589f6c PZ |
7657 | if (tl->flags & SDTL_OVERLAP || sched_feat(FORCE_SD_OVERLAP)) |
7658 | sd->flags |= SD_OVERLAP; | |
d110235d PZ |
7659 | if (cpumask_equal(cpu_map, sched_domain_span(sd))) |
7660 | break; | |
e3589f6c | 7661 | } |
d274cb30 | 7662 | |
d069b916 PZ |
7663 | while (sd->child) |
7664 | sd = sd->child; | |
7665 | ||
21d42ccf | 7666 | *per_cpu_ptr(d.sd, i) = sd; |
dce840a0 PZ |
7667 | } |
7668 | ||
7669 | /* Build the groups for the domains */ | |
7670 | for_each_cpu(i, cpu_map) { | |
7671 | for (sd = *per_cpu_ptr(d.sd, i); sd; sd = sd->parent) { | |
7672 | sd->span_weight = cpumask_weight(sched_domain_span(sd)); | |
e3589f6c PZ |
7673 | if (sd->flags & SD_OVERLAP) { |
7674 | if (build_overlap_sched_groups(sd, i)) | |
7675 | goto error; | |
7676 | } else { | |
7677 | if (build_sched_groups(sd, i)) | |
7678 | goto error; | |
7679 | } | |
1cf51902 | 7680 | } |
a06dadbe | 7681 | } |
9c1cfda2 | 7682 | |
1da177e4 | 7683 | /* Calculate CPU power for physical packages and nodes */ |
a9c9a9b6 PZ |
7684 | for (i = nr_cpumask_bits-1; i >= 0; i--) { |
7685 | if (!cpumask_test_cpu(i, cpu_map)) | |
7686 | continue; | |
9c1cfda2 | 7687 | |
dce840a0 PZ |
7688 | for (sd = *per_cpu_ptr(d.sd, i); sd; sd = sd->parent) { |
7689 | claim_allocations(i, sd); | |
cd4ea6ae | 7690 | init_sched_groups_power(i, sd); |
dce840a0 | 7691 | } |
f712c0c7 | 7692 | } |
9c1cfda2 | 7693 | |
1da177e4 | 7694 | /* Attach the domains */ |
dce840a0 | 7695 | rcu_read_lock(); |
abcd083a | 7696 | for_each_cpu(i, cpu_map) { |
21d42ccf | 7697 | sd = *per_cpu_ptr(d.sd, i); |
49a02c51 | 7698 | cpu_attach_domain(sd, d.rd, i); |
1da177e4 | 7699 | } |
dce840a0 | 7700 | rcu_read_unlock(); |
51888ca2 | 7701 | |
822ff793 | 7702 | ret = 0; |
51888ca2 | 7703 | error: |
2109b99e | 7704 | __free_domain_allocs(&d, alloc_state, cpu_map); |
822ff793 | 7705 | return ret; |
1da177e4 | 7706 | } |
029190c5 | 7707 | |
acc3f5d7 | 7708 | static cpumask_var_t *doms_cur; /* current sched domains */ |
029190c5 | 7709 | static int ndoms_cur; /* number of sched domains in 'doms_cur' */ |
4285f594 IM |
7710 | static struct sched_domain_attr *dattr_cur; |
7711 | /* attribues of custom domains in 'doms_cur' */ | |
029190c5 PJ |
7712 | |
7713 | /* | |
7714 | * Special case: If a kmalloc of a doms_cur partition (array of | |
4212823f RR |
7715 | * cpumask) fails, then fallback to a single sched domain, |
7716 | * as determined by the single cpumask fallback_doms. | |
029190c5 | 7717 | */ |
4212823f | 7718 | static cpumask_var_t fallback_doms; |
029190c5 | 7719 | |
ee79d1bd HC |
7720 | /* |
7721 | * arch_update_cpu_topology lets virtualized architectures update the | |
7722 | * cpu core maps. It is supposed to return 1 if the topology changed | |
7723 | * or 0 if it stayed the same. | |
7724 | */ | |
7725 | int __attribute__((weak)) arch_update_cpu_topology(void) | |
22e52b07 | 7726 | { |
ee79d1bd | 7727 | return 0; |
22e52b07 HC |
7728 | } |
7729 | ||
acc3f5d7 RR |
7730 | cpumask_var_t *alloc_sched_domains(unsigned int ndoms) |
7731 | { | |
7732 | int i; | |
7733 | cpumask_var_t *doms; | |
7734 | ||
7735 | doms = kmalloc(sizeof(*doms) * ndoms, GFP_KERNEL); | |
7736 | if (!doms) | |
7737 | return NULL; | |
7738 | for (i = 0; i < ndoms; i++) { | |
7739 | if (!alloc_cpumask_var(&doms[i], GFP_KERNEL)) { | |
7740 | free_sched_domains(doms, i); | |
7741 | return NULL; | |
7742 | } | |
7743 | } | |
7744 | return doms; | |
7745 | } | |
7746 | ||
7747 | void free_sched_domains(cpumask_var_t doms[], unsigned int ndoms) | |
7748 | { | |
7749 | unsigned int i; | |
7750 | for (i = 0; i < ndoms; i++) | |
7751 | free_cpumask_var(doms[i]); | |
7752 | kfree(doms); | |
7753 | } | |
7754 | ||
1a20ff27 | 7755 | /* |
41a2d6cf | 7756 | * Set up scheduler domains and groups. Callers must hold the hotplug lock. |
029190c5 PJ |
7757 | * For now this just excludes isolated cpus, but could be used to |
7758 | * exclude other special cases in the future. | |
1a20ff27 | 7759 | */ |
c4a8849a | 7760 | static int init_sched_domains(const struct cpumask *cpu_map) |
1a20ff27 | 7761 | { |
7378547f MM |
7762 | int err; |
7763 | ||
22e52b07 | 7764 | arch_update_cpu_topology(); |
029190c5 | 7765 | ndoms_cur = 1; |
acc3f5d7 | 7766 | doms_cur = alloc_sched_domains(ndoms_cur); |
029190c5 | 7767 | if (!doms_cur) |
acc3f5d7 RR |
7768 | doms_cur = &fallback_doms; |
7769 | cpumask_andnot(doms_cur[0], cpu_map, cpu_isolated_map); | |
1d3504fc | 7770 | dattr_cur = NULL; |
dce840a0 | 7771 | err = build_sched_domains(doms_cur[0], NULL); |
6382bc90 | 7772 | register_sched_domain_sysctl(); |
7378547f MM |
7773 | |
7774 | return err; | |
1a20ff27 DG |
7775 | } |
7776 | ||
1a20ff27 DG |
7777 | /* |
7778 | * Detach sched domains from a group of cpus specified in cpu_map | |
7779 | * These cpus will now be attached to the NULL domain | |
7780 | */ | |
96f874e2 | 7781 | static void detach_destroy_domains(const struct cpumask *cpu_map) |
1a20ff27 DG |
7782 | { |
7783 | int i; | |
7784 | ||
dce840a0 | 7785 | rcu_read_lock(); |
abcd083a | 7786 | for_each_cpu(i, cpu_map) |
57d885fe | 7787 | cpu_attach_domain(NULL, &def_root_domain, i); |
dce840a0 | 7788 | rcu_read_unlock(); |
1a20ff27 DG |
7789 | } |
7790 | ||
1d3504fc HS |
7791 | /* handle null as "default" */ |
7792 | static int dattrs_equal(struct sched_domain_attr *cur, int idx_cur, | |
7793 | struct sched_domain_attr *new, int idx_new) | |
7794 | { | |
7795 | struct sched_domain_attr tmp; | |
7796 | ||
7797 | /* fast path */ | |
7798 | if (!new && !cur) | |
7799 | return 1; | |
7800 | ||
7801 | tmp = SD_ATTR_INIT; | |
7802 | return !memcmp(cur ? (cur + idx_cur) : &tmp, | |
7803 | new ? (new + idx_new) : &tmp, | |
7804 | sizeof(struct sched_domain_attr)); | |
7805 | } | |
7806 | ||
029190c5 PJ |
7807 | /* |
7808 | * Partition sched domains as specified by the 'ndoms_new' | |
41a2d6cf | 7809 | * cpumasks in the array doms_new[] of cpumasks. This compares |
029190c5 PJ |
7810 | * doms_new[] to the current sched domain partitioning, doms_cur[]. |
7811 | * It destroys each deleted domain and builds each new domain. | |
7812 | * | |
acc3f5d7 | 7813 | * 'doms_new' is an array of cpumask_var_t's of length 'ndoms_new'. |
41a2d6cf IM |
7814 | * The masks don't intersect (don't overlap.) We should setup one |
7815 | * sched domain for each mask. CPUs not in any of the cpumasks will | |
7816 | * not be load balanced. If the same cpumask appears both in the | |
029190c5 PJ |
7817 | * current 'doms_cur' domains and in the new 'doms_new', we can leave |
7818 | * it as it is. | |
7819 | * | |
acc3f5d7 RR |
7820 | * The passed in 'doms_new' should be allocated using |
7821 | * alloc_sched_domains. This routine takes ownership of it and will | |
7822 | * free_sched_domains it when done with it. If the caller failed the | |
7823 | * alloc call, then it can pass in doms_new == NULL && ndoms_new == 1, | |
7824 | * and partition_sched_domains() will fallback to the single partition | |
7825 | * 'fallback_doms', it also forces the domains to be rebuilt. | |
029190c5 | 7826 | * |
96f874e2 | 7827 | * If doms_new == NULL it will be replaced with cpu_online_mask. |
700018e0 LZ |
7828 | * ndoms_new == 0 is a special case for destroying existing domains, |
7829 | * and it will not create the default domain. | |
dfb512ec | 7830 | * |
029190c5 PJ |
7831 | * Call with hotplug lock held |
7832 | */ | |
acc3f5d7 | 7833 | void partition_sched_domains(int ndoms_new, cpumask_var_t doms_new[], |
1d3504fc | 7834 | struct sched_domain_attr *dattr_new) |
029190c5 | 7835 | { |
dfb512ec | 7836 | int i, j, n; |
d65bd5ec | 7837 | int new_topology; |
029190c5 | 7838 | |
712555ee | 7839 | mutex_lock(&sched_domains_mutex); |
a1835615 | 7840 | |
7378547f MM |
7841 | /* always unregister in case we don't destroy any domains */ |
7842 | unregister_sched_domain_sysctl(); | |
7843 | ||
d65bd5ec HC |
7844 | /* Let architecture update cpu core mappings. */ |
7845 | new_topology = arch_update_cpu_topology(); | |
7846 | ||
dfb512ec | 7847 | n = doms_new ? ndoms_new : 0; |
029190c5 PJ |
7848 | |
7849 | /* Destroy deleted domains */ | |
7850 | for (i = 0; i < ndoms_cur; i++) { | |
d65bd5ec | 7851 | for (j = 0; j < n && !new_topology; j++) { |
acc3f5d7 | 7852 | if (cpumask_equal(doms_cur[i], doms_new[j]) |
1d3504fc | 7853 | && dattrs_equal(dattr_cur, i, dattr_new, j)) |
029190c5 PJ |
7854 | goto match1; |
7855 | } | |
7856 | /* no match - a current sched domain not in new doms_new[] */ | |
acc3f5d7 | 7857 | detach_destroy_domains(doms_cur[i]); |
029190c5 PJ |
7858 | match1: |
7859 | ; | |
7860 | } | |
7861 | ||
e761b772 MK |
7862 | if (doms_new == NULL) { |
7863 | ndoms_cur = 0; | |
acc3f5d7 | 7864 | doms_new = &fallback_doms; |
6ad4c188 | 7865 | cpumask_andnot(doms_new[0], cpu_active_mask, cpu_isolated_map); |
faa2f98f | 7866 | WARN_ON_ONCE(dattr_new); |
e761b772 MK |
7867 | } |
7868 | ||
029190c5 PJ |
7869 | /* Build new domains */ |
7870 | for (i = 0; i < ndoms_new; i++) { | |
d65bd5ec | 7871 | for (j = 0; j < ndoms_cur && !new_topology; j++) { |
acc3f5d7 | 7872 | if (cpumask_equal(doms_new[i], doms_cur[j]) |
1d3504fc | 7873 | && dattrs_equal(dattr_new, i, dattr_cur, j)) |
029190c5 PJ |
7874 | goto match2; |
7875 | } | |
7876 | /* no match - add a new doms_new */ | |
dce840a0 | 7877 | build_sched_domains(doms_new[i], dattr_new ? dattr_new + i : NULL); |
029190c5 PJ |
7878 | match2: |
7879 | ; | |
7880 | } | |
7881 | ||
7882 | /* Remember the new sched domains */ | |
acc3f5d7 RR |
7883 | if (doms_cur != &fallback_doms) |
7884 | free_sched_domains(doms_cur, ndoms_cur); | |
1d3504fc | 7885 | kfree(dattr_cur); /* kfree(NULL) is safe */ |
029190c5 | 7886 | doms_cur = doms_new; |
1d3504fc | 7887 | dattr_cur = dattr_new; |
029190c5 | 7888 | ndoms_cur = ndoms_new; |
7378547f MM |
7889 | |
7890 | register_sched_domain_sysctl(); | |
a1835615 | 7891 | |
712555ee | 7892 | mutex_unlock(&sched_domains_mutex); |
029190c5 PJ |
7893 | } |
7894 | ||
5c45bf27 | 7895 | #if defined(CONFIG_SCHED_MC) || defined(CONFIG_SCHED_SMT) |
c4a8849a | 7896 | static void reinit_sched_domains(void) |
5c45bf27 | 7897 | { |
95402b38 | 7898 | get_online_cpus(); |
dfb512ec MK |
7899 | |
7900 | /* Destroy domains first to force the rebuild */ | |
7901 | partition_sched_domains(0, NULL, NULL); | |
7902 | ||
e761b772 | 7903 | rebuild_sched_domains(); |
95402b38 | 7904 | put_online_cpus(); |
5c45bf27 SS |
7905 | } |
7906 | ||
7907 | static ssize_t sched_power_savings_store(const char *buf, size_t count, int smt) | |
7908 | { | |
afb8a9b7 | 7909 | unsigned int level = 0; |
5c45bf27 | 7910 | |
afb8a9b7 GS |
7911 | if (sscanf(buf, "%u", &level) != 1) |
7912 | return -EINVAL; | |
7913 | ||
7914 | /* | |
7915 | * level is always be positive so don't check for | |
7916 | * level < POWERSAVINGS_BALANCE_NONE which is 0 | |
7917 | * What happens on 0 or 1 byte write, | |
7918 | * need to check for count as well? | |
7919 | */ | |
7920 | ||
7921 | if (level >= MAX_POWERSAVINGS_BALANCE_LEVELS) | |
5c45bf27 SS |
7922 | return -EINVAL; |
7923 | ||
7924 | if (smt) | |
afb8a9b7 | 7925 | sched_smt_power_savings = level; |
5c45bf27 | 7926 | else |
afb8a9b7 | 7927 | sched_mc_power_savings = level; |
5c45bf27 | 7928 | |
c4a8849a | 7929 | reinit_sched_domains(); |
5c45bf27 | 7930 | |
c70f22d2 | 7931 | return count; |
5c45bf27 SS |
7932 | } |
7933 | ||
5c45bf27 | 7934 | #ifdef CONFIG_SCHED_MC |
f718cd4a | 7935 | static ssize_t sched_mc_power_savings_show(struct sysdev_class *class, |
c9be0a36 | 7936 | struct sysdev_class_attribute *attr, |
f718cd4a | 7937 | char *page) |
5c45bf27 SS |
7938 | { |
7939 | return sprintf(page, "%u\n", sched_mc_power_savings); | |
7940 | } | |
f718cd4a | 7941 | static ssize_t sched_mc_power_savings_store(struct sysdev_class *class, |
c9be0a36 | 7942 | struct sysdev_class_attribute *attr, |
48f24c4d | 7943 | const char *buf, size_t count) |
5c45bf27 SS |
7944 | { |
7945 | return sched_power_savings_store(buf, count, 0); | |
7946 | } | |
f718cd4a AK |
7947 | static SYSDEV_CLASS_ATTR(sched_mc_power_savings, 0644, |
7948 | sched_mc_power_savings_show, | |
7949 | sched_mc_power_savings_store); | |
5c45bf27 SS |
7950 | #endif |
7951 | ||
7952 | #ifdef CONFIG_SCHED_SMT | |
f718cd4a | 7953 | static ssize_t sched_smt_power_savings_show(struct sysdev_class *dev, |
c9be0a36 | 7954 | struct sysdev_class_attribute *attr, |
f718cd4a | 7955 | char *page) |
5c45bf27 SS |
7956 | { |
7957 | return sprintf(page, "%u\n", sched_smt_power_savings); | |
7958 | } | |
f718cd4a | 7959 | static ssize_t sched_smt_power_savings_store(struct sysdev_class *dev, |
c9be0a36 | 7960 | struct sysdev_class_attribute *attr, |
48f24c4d | 7961 | const char *buf, size_t count) |
5c45bf27 SS |
7962 | { |
7963 | return sched_power_savings_store(buf, count, 1); | |
7964 | } | |
f718cd4a AK |
7965 | static SYSDEV_CLASS_ATTR(sched_smt_power_savings, 0644, |
7966 | sched_smt_power_savings_show, | |
6707de00 AB |
7967 | sched_smt_power_savings_store); |
7968 | #endif | |
7969 | ||
39aac648 | 7970 | int __init sched_create_sysfs_power_savings_entries(struct sysdev_class *cls) |
6707de00 AB |
7971 | { |
7972 | int err = 0; | |
7973 | ||
7974 | #ifdef CONFIG_SCHED_SMT | |
7975 | if (smt_capable()) | |
7976 | err = sysfs_create_file(&cls->kset.kobj, | |
7977 | &attr_sched_smt_power_savings.attr); | |
7978 | #endif | |
7979 | #ifdef CONFIG_SCHED_MC | |
7980 | if (!err && mc_capable()) | |
7981 | err = sysfs_create_file(&cls->kset.kobj, | |
7982 | &attr_sched_mc_power_savings.attr); | |
7983 | #endif | |
7984 | return err; | |
7985 | } | |
6d6bc0ad | 7986 | #endif /* CONFIG_SCHED_MC || CONFIG_SCHED_SMT */ |
5c45bf27 | 7987 | |
1da177e4 | 7988 | /* |
3a101d05 TH |
7989 | * Update cpusets according to cpu_active mask. If cpusets are |
7990 | * disabled, cpuset_update_active_cpus() becomes a simple wrapper | |
7991 | * around partition_sched_domains(). | |
1da177e4 | 7992 | */ |
0b2e918a TH |
7993 | static int cpuset_cpu_active(struct notifier_block *nfb, unsigned long action, |
7994 | void *hcpu) | |
e761b772 | 7995 | { |
3a101d05 | 7996 | switch (action & ~CPU_TASKS_FROZEN) { |
e761b772 | 7997 | case CPU_ONLINE: |
6ad4c188 | 7998 | case CPU_DOWN_FAILED: |
3a101d05 | 7999 | cpuset_update_active_cpus(); |
e761b772 | 8000 | return NOTIFY_OK; |
3a101d05 TH |
8001 | default: |
8002 | return NOTIFY_DONE; | |
8003 | } | |
8004 | } | |
e761b772 | 8005 | |
0b2e918a TH |
8006 | static int cpuset_cpu_inactive(struct notifier_block *nfb, unsigned long action, |
8007 | void *hcpu) | |
3a101d05 TH |
8008 | { |
8009 | switch (action & ~CPU_TASKS_FROZEN) { | |
8010 | case CPU_DOWN_PREPARE: | |
8011 | cpuset_update_active_cpus(); | |
8012 | return NOTIFY_OK; | |
e761b772 MK |
8013 | default: |
8014 | return NOTIFY_DONE; | |
8015 | } | |
8016 | } | |
e761b772 MK |
8017 | |
8018 | static int update_runtime(struct notifier_block *nfb, | |
8019 | unsigned long action, void *hcpu) | |
1da177e4 | 8020 | { |
7def2be1 PZ |
8021 | int cpu = (int)(long)hcpu; |
8022 | ||
1da177e4 | 8023 | switch (action) { |
1da177e4 | 8024 | case CPU_DOWN_PREPARE: |
8bb78442 | 8025 | case CPU_DOWN_PREPARE_FROZEN: |
7def2be1 | 8026 | disable_runtime(cpu_rq(cpu)); |
1da177e4 LT |
8027 | return NOTIFY_OK; |
8028 | ||
1da177e4 | 8029 | case CPU_DOWN_FAILED: |
8bb78442 | 8030 | case CPU_DOWN_FAILED_FROZEN: |
1da177e4 | 8031 | case CPU_ONLINE: |
8bb78442 | 8032 | case CPU_ONLINE_FROZEN: |
7def2be1 | 8033 | enable_runtime(cpu_rq(cpu)); |
e761b772 MK |
8034 | return NOTIFY_OK; |
8035 | ||
1da177e4 LT |
8036 | default: |
8037 | return NOTIFY_DONE; | |
8038 | } | |
1da177e4 | 8039 | } |
1da177e4 LT |
8040 | |
8041 | void __init sched_init_smp(void) | |
8042 | { | |
dcc30a35 RR |
8043 | cpumask_var_t non_isolated_cpus; |
8044 | ||
8045 | alloc_cpumask_var(&non_isolated_cpus, GFP_KERNEL); | |
cb5fd13f | 8046 | alloc_cpumask_var(&fallback_doms, GFP_KERNEL); |
5c1e1767 | 8047 | |
95402b38 | 8048 | get_online_cpus(); |
712555ee | 8049 | mutex_lock(&sched_domains_mutex); |
c4a8849a | 8050 | init_sched_domains(cpu_active_mask); |
dcc30a35 RR |
8051 | cpumask_andnot(non_isolated_cpus, cpu_possible_mask, cpu_isolated_map); |
8052 | if (cpumask_empty(non_isolated_cpus)) | |
8053 | cpumask_set_cpu(smp_processor_id(), non_isolated_cpus); | |
712555ee | 8054 | mutex_unlock(&sched_domains_mutex); |
95402b38 | 8055 | put_online_cpus(); |
e761b772 | 8056 | |
3a101d05 TH |
8057 | hotcpu_notifier(cpuset_cpu_active, CPU_PRI_CPUSET_ACTIVE); |
8058 | hotcpu_notifier(cpuset_cpu_inactive, CPU_PRI_CPUSET_INACTIVE); | |
e761b772 MK |
8059 | |
8060 | /* RT runtime code needs to handle some hotplug events */ | |
8061 | hotcpu_notifier(update_runtime, 0); | |
8062 | ||
b328ca18 | 8063 | init_hrtick(); |
5c1e1767 NP |
8064 | |
8065 | /* Move init over to a non-isolated CPU */ | |
dcc30a35 | 8066 | if (set_cpus_allowed_ptr(current, non_isolated_cpus) < 0) |
5c1e1767 | 8067 | BUG(); |
19978ca6 | 8068 | sched_init_granularity(); |
dcc30a35 | 8069 | free_cpumask_var(non_isolated_cpus); |
4212823f | 8070 | |
0e3900e6 | 8071 | init_sched_rt_class(); |
1da177e4 LT |
8072 | } |
8073 | #else | |
8074 | void __init sched_init_smp(void) | |
8075 | { | |
19978ca6 | 8076 | sched_init_granularity(); |
1da177e4 LT |
8077 | } |
8078 | #endif /* CONFIG_SMP */ | |
8079 | ||
cd1bb94b AB |
8080 | const_debug unsigned int sysctl_timer_migration = 1; |
8081 | ||
1da177e4 LT |
8082 | int in_sched_functions(unsigned long addr) |
8083 | { | |
1da177e4 LT |
8084 | return in_lock_functions(addr) || |
8085 | (addr >= (unsigned long)__sched_text_start | |
8086 | && addr < (unsigned long)__sched_text_end); | |
8087 | } | |
8088 | ||
acb5a9ba | 8089 | static void init_cfs_rq(struct cfs_rq *cfs_rq) |
dd41f596 IM |
8090 | { |
8091 | cfs_rq->tasks_timeline = RB_ROOT; | |
4a55bd5e | 8092 | INIT_LIST_HEAD(&cfs_rq->tasks); |
67e9fb2a | 8093 | cfs_rq->min_vruntime = (u64)(-(1LL << 20)); |
c64be78f PZ |
8094 | #ifndef CONFIG_64BIT |
8095 | cfs_rq->min_vruntime_copy = cfs_rq->min_vruntime; | |
8096 | #endif | |
dd41f596 IM |
8097 | } |
8098 | ||
fa85ae24 PZ |
8099 | static void init_rt_rq(struct rt_rq *rt_rq, struct rq *rq) |
8100 | { | |
8101 | struct rt_prio_array *array; | |
8102 | int i; | |
8103 | ||
8104 | array = &rt_rq->active; | |
8105 | for (i = 0; i < MAX_RT_PRIO; i++) { | |
8106 | INIT_LIST_HEAD(array->queue + i); | |
8107 | __clear_bit(i, array->bitmap); | |
8108 | } | |
8109 | /* delimiter for bitsearch: */ | |
8110 | __set_bit(MAX_RT_PRIO, array->bitmap); | |
8111 | ||
acb5a9ba | 8112 | #if defined CONFIG_SMP |
e864c499 GH |
8113 | rt_rq->highest_prio.curr = MAX_RT_PRIO; |
8114 | rt_rq->highest_prio.next = MAX_RT_PRIO; | |
fa85ae24 | 8115 | rt_rq->rt_nr_migratory = 0; |
fa85ae24 | 8116 | rt_rq->overloaded = 0; |
732375c6 | 8117 | plist_head_init(&rt_rq->pushable_tasks); |
fa85ae24 PZ |
8118 | #endif |
8119 | ||
8120 | rt_rq->rt_time = 0; | |
8121 | rt_rq->rt_throttled = 0; | |
ac086bc2 | 8122 | rt_rq->rt_runtime = 0; |
0986b11b | 8123 | raw_spin_lock_init(&rt_rq->rt_runtime_lock); |
fa85ae24 PZ |
8124 | } |
8125 | ||
6f505b16 | 8126 | #ifdef CONFIG_FAIR_GROUP_SCHED |
ec7dc8ac | 8127 | static void init_tg_cfs_entry(struct task_group *tg, struct cfs_rq *cfs_rq, |
3d4b47b4 | 8128 | struct sched_entity *se, int cpu, |
ec7dc8ac | 8129 | struct sched_entity *parent) |
6f505b16 | 8130 | { |
ec7dc8ac | 8131 | struct rq *rq = cpu_rq(cpu); |
acb5a9ba | 8132 | |
6f505b16 | 8133 | cfs_rq->tg = tg; |
acb5a9ba JS |
8134 | cfs_rq->rq = rq; |
8135 | #ifdef CONFIG_SMP | |
8136 | /* allow initial update_cfs_load() to truncate */ | |
8137 | cfs_rq->load_stamp = 1; | |
8138 | #endif | |
ab84d31e | 8139 | init_cfs_rq_runtime(cfs_rq); |
6f505b16 | 8140 | |
acb5a9ba | 8141 | tg->cfs_rq[cpu] = cfs_rq; |
6f505b16 | 8142 | tg->se[cpu] = se; |
acb5a9ba | 8143 | |
07e06b01 | 8144 | /* se could be NULL for root_task_group */ |
354d60c2 DG |
8145 | if (!se) |
8146 | return; | |
8147 | ||
ec7dc8ac DG |
8148 | if (!parent) |
8149 | se->cfs_rq = &rq->cfs; | |
8150 | else | |
8151 | se->cfs_rq = parent->my_q; | |
8152 | ||
6f505b16 | 8153 | se->my_q = cfs_rq; |
9437178f | 8154 | update_load_set(&se->load, 0); |
ec7dc8ac | 8155 | se->parent = parent; |
6f505b16 | 8156 | } |
052f1dc7 | 8157 | #endif |
6f505b16 | 8158 | |
052f1dc7 | 8159 | #ifdef CONFIG_RT_GROUP_SCHED |
ec7dc8ac | 8160 | static void init_tg_rt_entry(struct task_group *tg, struct rt_rq *rt_rq, |
3d4b47b4 | 8161 | struct sched_rt_entity *rt_se, int cpu, |
ec7dc8ac | 8162 | struct sched_rt_entity *parent) |
6f505b16 | 8163 | { |
ec7dc8ac DG |
8164 | struct rq *rq = cpu_rq(cpu); |
8165 | ||
acb5a9ba JS |
8166 | rt_rq->highest_prio.curr = MAX_RT_PRIO; |
8167 | rt_rq->rt_nr_boosted = 0; | |
8168 | rt_rq->rq = rq; | |
6f505b16 | 8169 | rt_rq->tg = tg; |
6f505b16 | 8170 | |
acb5a9ba | 8171 | tg->rt_rq[cpu] = rt_rq; |
6f505b16 | 8172 | tg->rt_se[cpu] = rt_se; |
acb5a9ba | 8173 | |
354d60c2 DG |
8174 | if (!rt_se) |
8175 | return; | |
8176 | ||
ec7dc8ac DG |
8177 | if (!parent) |
8178 | rt_se->rt_rq = &rq->rt; | |
8179 | else | |
8180 | rt_se->rt_rq = parent->my_q; | |
8181 | ||
6f505b16 | 8182 | rt_se->my_q = rt_rq; |
ec7dc8ac | 8183 | rt_se->parent = parent; |
6f505b16 PZ |
8184 | INIT_LIST_HEAD(&rt_se->run_list); |
8185 | } | |
8186 | #endif | |
8187 | ||
1da177e4 LT |
8188 | void __init sched_init(void) |
8189 | { | |
dd41f596 | 8190 | int i, j; |
434d53b0 MT |
8191 | unsigned long alloc_size = 0, ptr; |
8192 | ||
8193 | #ifdef CONFIG_FAIR_GROUP_SCHED | |
8194 | alloc_size += 2 * nr_cpu_ids * sizeof(void **); | |
8195 | #endif | |
8196 | #ifdef CONFIG_RT_GROUP_SCHED | |
8197 | alloc_size += 2 * nr_cpu_ids * sizeof(void **); | |
eff766a6 | 8198 | #endif |
df7c8e84 | 8199 | #ifdef CONFIG_CPUMASK_OFFSTACK |
8c083f08 | 8200 | alloc_size += num_possible_cpus() * cpumask_size(); |
434d53b0 | 8201 | #endif |
434d53b0 | 8202 | if (alloc_size) { |
36b7b6d4 | 8203 | ptr = (unsigned long)kzalloc(alloc_size, GFP_NOWAIT); |
434d53b0 MT |
8204 | |
8205 | #ifdef CONFIG_FAIR_GROUP_SCHED | |
07e06b01 | 8206 | root_task_group.se = (struct sched_entity **)ptr; |
434d53b0 MT |
8207 | ptr += nr_cpu_ids * sizeof(void **); |
8208 | ||
07e06b01 | 8209 | root_task_group.cfs_rq = (struct cfs_rq **)ptr; |
434d53b0 | 8210 | ptr += nr_cpu_ids * sizeof(void **); |
eff766a6 | 8211 | |
6d6bc0ad | 8212 | #endif /* CONFIG_FAIR_GROUP_SCHED */ |
434d53b0 | 8213 | #ifdef CONFIG_RT_GROUP_SCHED |
07e06b01 | 8214 | root_task_group.rt_se = (struct sched_rt_entity **)ptr; |
434d53b0 MT |
8215 | ptr += nr_cpu_ids * sizeof(void **); |
8216 | ||
07e06b01 | 8217 | root_task_group.rt_rq = (struct rt_rq **)ptr; |
eff766a6 PZ |
8218 | ptr += nr_cpu_ids * sizeof(void **); |
8219 | ||
6d6bc0ad | 8220 | #endif /* CONFIG_RT_GROUP_SCHED */ |
df7c8e84 RR |
8221 | #ifdef CONFIG_CPUMASK_OFFSTACK |
8222 | for_each_possible_cpu(i) { | |
8223 | per_cpu(load_balance_tmpmask, i) = (void *)ptr; | |
8224 | ptr += cpumask_size(); | |
8225 | } | |
8226 | #endif /* CONFIG_CPUMASK_OFFSTACK */ | |
434d53b0 | 8227 | } |
dd41f596 | 8228 | |
57d885fe GH |
8229 | #ifdef CONFIG_SMP |
8230 | init_defrootdomain(); | |
8231 | #endif | |
8232 | ||
d0b27fa7 PZ |
8233 | init_rt_bandwidth(&def_rt_bandwidth, |
8234 | global_rt_period(), global_rt_runtime()); | |
8235 | ||
8236 | #ifdef CONFIG_RT_GROUP_SCHED | |
07e06b01 | 8237 | init_rt_bandwidth(&root_task_group.rt_bandwidth, |
d0b27fa7 | 8238 | global_rt_period(), global_rt_runtime()); |
6d6bc0ad | 8239 | #endif /* CONFIG_RT_GROUP_SCHED */ |
d0b27fa7 | 8240 | |
7c941438 | 8241 | #ifdef CONFIG_CGROUP_SCHED |
07e06b01 YZ |
8242 | list_add(&root_task_group.list, &task_groups); |
8243 | INIT_LIST_HEAD(&root_task_group.children); | |
5091faa4 | 8244 | autogroup_init(&init_task); |
7c941438 | 8245 | #endif /* CONFIG_CGROUP_SCHED */ |
6f505b16 | 8246 | |
0a945022 | 8247 | for_each_possible_cpu(i) { |
70b97a7f | 8248 | struct rq *rq; |
1da177e4 LT |
8249 | |
8250 | rq = cpu_rq(i); | |
05fa785c | 8251 | raw_spin_lock_init(&rq->lock); |
7897986b | 8252 | rq->nr_running = 0; |
dce48a84 TG |
8253 | rq->calc_load_active = 0; |
8254 | rq->calc_load_update = jiffies + LOAD_FREQ; | |
acb5a9ba | 8255 | init_cfs_rq(&rq->cfs); |
6f505b16 | 8256 | init_rt_rq(&rq->rt, rq); |
dd41f596 | 8257 | #ifdef CONFIG_FAIR_GROUP_SCHED |
07e06b01 | 8258 | root_task_group.shares = root_task_group_load; |
6f505b16 | 8259 | INIT_LIST_HEAD(&rq->leaf_cfs_rq_list); |
354d60c2 | 8260 | /* |
07e06b01 | 8261 | * How much cpu bandwidth does root_task_group get? |
354d60c2 DG |
8262 | * |
8263 | * In case of task-groups formed thr' the cgroup filesystem, it | |
8264 | * gets 100% of the cpu resources in the system. This overall | |
8265 | * system cpu resource is divided among the tasks of | |
07e06b01 | 8266 | * root_task_group and its child task-groups in a fair manner, |
354d60c2 DG |
8267 | * based on each entity's (task or task-group's) weight |
8268 | * (se->load.weight). | |
8269 | * | |
07e06b01 | 8270 | * In other words, if root_task_group has 10 tasks of weight |
354d60c2 DG |
8271 | * 1024) and two child groups A0 and A1 (of weight 1024 each), |
8272 | * then A0's share of the cpu resource is: | |
8273 | * | |
0d905bca | 8274 | * A0's bandwidth = 1024 / (10*1024 + 1024 + 1024) = 8.33% |
354d60c2 | 8275 | * |
07e06b01 YZ |
8276 | * We achieve this by letting root_task_group's tasks sit |
8277 | * directly in rq->cfs (i.e root_task_group->se[] = NULL). | |
354d60c2 | 8278 | */ |
ab84d31e | 8279 | init_cfs_bandwidth(&root_task_group.cfs_bandwidth); |
07e06b01 | 8280 | init_tg_cfs_entry(&root_task_group, &rq->cfs, NULL, i, NULL); |
354d60c2 DG |
8281 | #endif /* CONFIG_FAIR_GROUP_SCHED */ |
8282 | ||
8283 | rq->rt.rt_runtime = def_rt_bandwidth.rt_runtime; | |
052f1dc7 | 8284 | #ifdef CONFIG_RT_GROUP_SCHED |
6f505b16 | 8285 | INIT_LIST_HEAD(&rq->leaf_rt_rq_list); |
07e06b01 | 8286 | init_tg_rt_entry(&root_task_group, &rq->rt, NULL, i, NULL); |
dd41f596 | 8287 | #endif |
1da177e4 | 8288 | |
dd41f596 IM |
8289 | for (j = 0; j < CPU_LOAD_IDX_MAX; j++) |
8290 | rq->cpu_load[j] = 0; | |
fdf3e95d VP |
8291 | |
8292 | rq->last_load_update_tick = jiffies; | |
8293 | ||
1da177e4 | 8294 | #ifdef CONFIG_SMP |
41c7ce9a | 8295 | rq->sd = NULL; |
57d885fe | 8296 | rq->rd = NULL; |
1399fa78 | 8297 | rq->cpu_power = SCHED_POWER_SCALE; |
3f029d3c | 8298 | rq->post_schedule = 0; |
1da177e4 | 8299 | rq->active_balance = 0; |
dd41f596 | 8300 | rq->next_balance = jiffies; |
1da177e4 | 8301 | rq->push_cpu = 0; |
0a2966b4 | 8302 | rq->cpu = i; |
1f11eb6a | 8303 | rq->online = 0; |
eae0c9df MG |
8304 | rq->idle_stamp = 0; |
8305 | rq->avg_idle = 2*sysctl_sched_migration_cost; | |
dc938520 | 8306 | rq_attach_root(rq, &def_root_domain); |
83cd4fe2 VP |
8307 | #ifdef CONFIG_NO_HZ |
8308 | rq->nohz_balance_kick = 0; | |
83cd4fe2 | 8309 | #endif |
1da177e4 | 8310 | #endif |
8f4d37ec | 8311 | init_rq_hrtick(rq); |
1da177e4 | 8312 | atomic_set(&rq->nr_iowait, 0); |
1da177e4 LT |
8313 | } |
8314 | ||
2dd73a4f | 8315 | set_load_weight(&init_task); |
b50f60ce | 8316 | |
e107be36 AK |
8317 | #ifdef CONFIG_PREEMPT_NOTIFIERS |
8318 | INIT_HLIST_HEAD(&init_task.preempt_notifiers); | |
8319 | #endif | |
8320 | ||
c9819f45 | 8321 | #ifdef CONFIG_SMP |
962cf36c | 8322 | open_softirq(SCHED_SOFTIRQ, run_rebalance_domains); |
c9819f45 CL |
8323 | #endif |
8324 | ||
b50f60ce | 8325 | #ifdef CONFIG_RT_MUTEXES |
732375c6 | 8326 | plist_head_init(&init_task.pi_waiters); |
b50f60ce HC |
8327 | #endif |
8328 | ||
1da177e4 LT |
8329 | /* |
8330 | * The boot idle thread does lazy MMU switching as well: | |
8331 | */ | |
8332 | atomic_inc(&init_mm.mm_count); | |
8333 | enter_lazy_tlb(&init_mm, current); | |
8334 | ||
8335 | /* | |
8336 | * Make us the idle thread. Technically, schedule() should not be | |
8337 | * called from this thread, however somewhere below it might be, | |
8338 | * but because we are the idle thread, we just pick up running again | |
8339 | * when this runqueue becomes "idle". | |
8340 | */ | |
8341 | init_idle(current, smp_processor_id()); | |
dce48a84 TG |
8342 | |
8343 | calc_load_update = jiffies + LOAD_FREQ; | |
8344 | ||
dd41f596 IM |
8345 | /* |
8346 | * During early bootup we pretend to be a normal task: | |
8347 | */ | |
8348 | current->sched_class = &fair_sched_class; | |
6892b75e | 8349 | |
6a7b3dc3 | 8350 | /* Allocate the nohz_cpu_mask if CONFIG_CPUMASK_OFFSTACK */ |
49557e62 | 8351 | zalloc_cpumask_var(&nohz_cpu_mask, GFP_NOWAIT); |
bf4d83f6 | 8352 | #ifdef CONFIG_SMP |
4cb98839 | 8353 | zalloc_cpumask_var(&sched_domains_tmpmask, GFP_NOWAIT); |
7d1e6a9b | 8354 | #ifdef CONFIG_NO_HZ |
83cd4fe2 VP |
8355 | zalloc_cpumask_var(&nohz.idle_cpus_mask, GFP_NOWAIT); |
8356 | alloc_cpumask_var(&nohz.grp_idle_mask, GFP_NOWAIT); | |
8357 | atomic_set(&nohz.load_balancer, nr_cpu_ids); | |
8358 | atomic_set(&nohz.first_pick_cpu, nr_cpu_ids); | |
8359 | atomic_set(&nohz.second_pick_cpu, nr_cpu_ids); | |
7d1e6a9b | 8360 | #endif |
bdddd296 RR |
8361 | /* May be allocated at isolcpus cmdline parse time */ |
8362 | if (cpu_isolated_map == NULL) | |
8363 | zalloc_cpumask_var(&cpu_isolated_map, GFP_NOWAIT); | |
bf4d83f6 | 8364 | #endif /* SMP */ |
6a7b3dc3 | 8365 | |
6892b75e | 8366 | scheduler_running = 1; |
1da177e4 LT |
8367 | } |
8368 | ||
d902db1e | 8369 | #ifdef CONFIG_DEBUG_ATOMIC_SLEEP |
e4aafea2 FW |
8370 | static inline int preempt_count_equals(int preempt_offset) |
8371 | { | |
234da7bc | 8372 | int nested = (preempt_count() & ~PREEMPT_ACTIVE) + rcu_preempt_depth(); |
e4aafea2 | 8373 | |
4ba8216c | 8374 | return (nested == preempt_offset); |
e4aafea2 FW |
8375 | } |
8376 | ||
d894837f | 8377 | void __might_sleep(const char *file, int line, int preempt_offset) |
1da177e4 | 8378 | { |
1da177e4 LT |
8379 | static unsigned long prev_jiffy; /* ratelimiting */ |
8380 | ||
e4aafea2 FW |
8381 | if ((preempt_count_equals(preempt_offset) && !irqs_disabled()) || |
8382 | system_state != SYSTEM_RUNNING || oops_in_progress) | |
aef745fc IM |
8383 | return; |
8384 | if (time_before(jiffies, prev_jiffy + HZ) && prev_jiffy) | |
8385 | return; | |
8386 | prev_jiffy = jiffies; | |
8387 | ||
3df0fc5b PZ |
8388 | printk(KERN_ERR |
8389 | "BUG: sleeping function called from invalid context at %s:%d\n", | |
8390 | file, line); | |
8391 | printk(KERN_ERR | |
8392 | "in_atomic(): %d, irqs_disabled(): %d, pid: %d, name: %s\n", | |
8393 | in_atomic(), irqs_disabled(), | |
8394 | current->pid, current->comm); | |
aef745fc IM |
8395 | |
8396 | debug_show_held_locks(current); | |
8397 | if (irqs_disabled()) | |
8398 | print_irqtrace_events(current); | |
8399 | dump_stack(); | |
1da177e4 LT |
8400 | } |
8401 | EXPORT_SYMBOL(__might_sleep); | |
8402 | #endif | |
8403 | ||
8404 | #ifdef CONFIG_MAGIC_SYSRQ | |
3a5e4dc1 AK |
8405 | static void normalize_task(struct rq *rq, struct task_struct *p) |
8406 | { | |
da7a735e PZ |
8407 | const struct sched_class *prev_class = p->sched_class; |
8408 | int old_prio = p->prio; | |
3a5e4dc1 | 8409 | int on_rq; |
3e51f33f | 8410 | |
fd2f4419 | 8411 | on_rq = p->on_rq; |
3a5e4dc1 AK |
8412 | if (on_rq) |
8413 | deactivate_task(rq, p, 0); | |
8414 | __setscheduler(rq, p, SCHED_NORMAL, 0); | |
8415 | if (on_rq) { | |
8416 | activate_task(rq, p, 0); | |
8417 | resched_task(rq->curr); | |
8418 | } | |
da7a735e PZ |
8419 | |
8420 | check_class_changed(rq, p, prev_class, old_prio); | |
3a5e4dc1 AK |
8421 | } |
8422 | ||
1da177e4 LT |
8423 | void normalize_rt_tasks(void) |
8424 | { | |
a0f98a1c | 8425 | struct task_struct *g, *p; |
1da177e4 | 8426 | unsigned long flags; |
70b97a7f | 8427 | struct rq *rq; |
1da177e4 | 8428 | |
4cf5d77a | 8429 | read_lock_irqsave(&tasklist_lock, flags); |
a0f98a1c | 8430 | do_each_thread(g, p) { |
178be793 IM |
8431 | /* |
8432 | * Only normalize user tasks: | |
8433 | */ | |
8434 | if (!p->mm) | |
8435 | continue; | |
8436 | ||
6cfb0d5d | 8437 | p->se.exec_start = 0; |
6cfb0d5d | 8438 | #ifdef CONFIG_SCHEDSTATS |
41acab88 LDM |
8439 | p->se.statistics.wait_start = 0; |
8440 | p->se.statistics.sleep_start = 0; | |
8441 | p->se.statistics.block_start = 0; | |
6cfb0d5d | 8442 | #endif |
dd41f596 IM |
8443 | |
8444 | if (!rt_task(p)) { | |
8445 | /* | |
8446 | * Renice negative nice level userspace | |
8447 | * tasks back to 0: | |
8448 | */ | |
8449 | if (TASK_NICE(p) < 0 && p->mm) | |
8450 | set_user_nice(p, 0); | |
1da177e4 | 8451 | continue; |
dd41f596 | 8452 | } |
1da177e4 | 8453 | |
1d615482 | 8454 | raw_spin_lock(&p->pi_lock); |
b29739f9 | 8455 | rq = __task_rq_lock(p); |
1da177e4 | 8456 | |
178be793 | 8457 | normalize_task(rq, p); |
3a5e4dc1 | 8458 | |
b29739f9 | 8459 | __task_rq_unlock(rq); |
1d615482 | 8460 | raw_spin_unlock(&p->pi_lock); |
a0f98a1c IM |
8461 | } while_each_thread(g, p); |
8462 | ||
4cf5d77a | 8463 | read_unlock_irqrestore(&tasklist_lock, flags); |
1da177e4 LT |
8464 | } |
8465 | ||
8466 | #endif /* CONFIG_MAGIC_SYSRQ */ | |
1df5c10a | 8467 | |
67fc4e0c | 8468 | #if defined(CONFIG_IA64) || defined(CONFIG_KGDB_KDB) |
1df5c10a | 8469 | /* |
67fc4e0c | 8470 | * These functions are only useful for the IA64 MCA handling, or kdb. |
1df5c10a LT |
8471 | * |
8472 | * They can only be called when the whole system has been | |
8473 | * stopped - every CPU needs to be quiescent, and no scheduling | |
8474 | * activity can take place. Using them for anything else would | |
8475 | * be a serious bug, and as a result, they aren't even visible | |
8476 | * under any other configuration. | |
8477 | */ | |
8478 | ||
8479 | /** | |
8480 | * curr_task - return the current task for a given cpu. | |
8481 | * @cpu: the processor in question. | |
8482 | * | |
8483 | * ONLY VALID WHEN THE WHOLE SYSTEM IS STOPPED! | |
8484 | */ | |
36c8b586 | 8485 | struct task_struct *curr_task(int cpu) |
1df5c10a LT |
8486 | { |
8487 | return cpu_curr(cpu); | |
8488 | } | |
8489 | ||
67fc4e0c JW |
8490 | #endif /* defined(CONFIG_IA64) || defined(CONFIG_KGDB_KDB) */ |
8491 | ||
8492 | #ifdef CONFIG_IA64 | |
1df5c10a LT |
8493 | /** |
8494 | * set_curr_task - set the current task for a given cpu. | |
8495 | * @cpu: the processor in question. | |
8496 | * @p: the task pointer to set. | |
8497 | * | |
8498 | * Description: This function must only be used when non-maskable interrupts | |
41a2d6cf IM |
8499 | * are serviced on a separate stack. It allows the architecture to switch the |
8500 | * notion of the current task on a cpu in a non-blocking manner. This function | |
1df5c10a LT |
8501 | * must be called with all CPU's synchronized, and interrupts disabled, the |
8502 | * and caller must save the original value of the current task (see | |
8503 | * curr_task() above) and restore that value before reenabling interrupts and | |
8504 | * re-starting the system. | |
8505 | * | |
8506 | * ONLY VALID WHEN THE WHOLE SYSTEM IS STOPPED! | |
8507 | */ | |
36c8b586 | 8508 | void set_curr_task(int cpu, struct task_struct *p) |
1df5c10a LT |
8509 | { |
8510 | cpu_curr(cpu) = p; | |
8511 | } | |
8512 | ||
8513 | #endif | |
29f59db3 | 8514 | |
bccbe08a PZ |
8515 | #ifdef CONFIG_FAIR_GROUP_SCHED |
8516 | static void free_fair_sched_group(struct task_group *tg) | |
6f505b16 PZ |
8517 | { |
8518 | int i; | |
8519 | ||
ab84d31e PT |
8520 | destroy_cfs_bandwidth(tg_cfs_bandwidth(tg)); |
8521 | ||
6f505b16 PZ |
8522 | for_each_possible_cpu(i) { |
8523 | if (tg->cfs_rq) | |
8524 | kfree(tg->cfs_rq[i]); | |
8525 | if (tg->se) | |
8526 | kfree(tg->se[i]); | |
6f505b16 PZ |
8527 | } |
8528 | ||
8529 | kfree(tg->cfs_rq); | |
8530 | kfree(tg->se); | |
6f505b16 PZ |
8531 | } |
8532 | ||
ec7dc8ac DG |
8533 | static |
8534 | int alloc_fair_sched_group(struct task_group *tg, struct task_group *parent) | |
29f59db3 | 8535 | { |
29f59db3 | 8536 | struct cfs_rq *cfs_rq; |
eab17229 | 8537 | struct sched_entity *se; |
29f59db3 SV |
8538 | int i; |
8539 | ||
434d53b0 | 8540 | tg->cfs_rq = kzalloc(sizeof(cfs_rq) * nr_cpu_ids, GFP_KERNEL); |
29f59db3 SV |
8541 | if (!tg->cfs_rq) |
8542 | goto err; | |
434d53b0 | 8543 | tg->se = kzalloc(sizeof(se) * nr_cpu_ids, GFP_KERNEL); |
29f59db3 SV |
8544 | if (!tg->se) |
8545 | goto err; | |
052f1dc7 PZ |
8546 | |
8547 | tg->shares = NICE_0_LOAD; | |
29f59db3 | 8548 | |
ab84d31e PT |
8549 | init_cfs_bandwidth(tg_cfs_bandwidth(tg)); |
8550 | ||
29f59db3 | 8551 | for_each_possible_cpu(i) { |
eab17229 LZ |
8552 | cfs_rq = kzalloc_node(sizeof(struct cfs_rq), |
8553 | GFP_KERNEL, cpu_to_node(i)); | |
29f59db3 SV |
8554 | if (!cfs_rq) |
8555 | goto err; | |
8556 | ||
eab17229 LZ |
8557 | se = kzalloc_node(sizeof(struct sched_entity), |
8558 | GFP_KERNEL, cpu_to_node(i)); | |
29f59db3 | 8559 | if (!se) |
dfc12eb2 | 8560 | goto err_free_rq; |
29f59db3 | 8561 | |
acb5a9ba | 8562 | init_cfs_rq(cfs_rq); |
3d4b47b4 | 8563 | init_tg_cfs_entry(tg, cfs_rq, se, i, parent->se[i]); |
bccbe08a PZ |
8564 | } |
8565 | ||
8566 | return 1; | |
8567 | ||
49246274 | 8568 | err_free_rq: |
dfc12eb2 | 8569 | kfree(cfs_rq); |
49246274 | 8570 | err: |
bccbe08a PZ |
8571 | return 0; |
8572 | } | |
8573 | ||
bccbe08a PZ |
8574 | static inline void unregister_fair_sched_group(struct task_group *tg, int cpu) |
8575 | { | |
3d4b47b4 PZ |
8576 | struct rq *rq = cpu_rq(cpu); |
8577 | unsigned long flags; | |
3d4b47b4 PZ |
8578 | |
8579 | /* | |
8580 | * Only empty task groups can be destroyed; so we can speculatively | |
8581 | * check on_list without danger of it being re-added. | |
8582 | */ | |
8583 | if (!tg->cfs_rq[cpu]->on_list) | |
8584 | return; | |
8585 | ||
8586 | raw_spin_lock_irqsave(&rq->lock, flags); | |
822bc180 | 8587 | list_del_leaf_cfs_rq(tg->cfs_rq[cpu]); |
3d4b47b4 | 8588 | raw_spin_unlock_irqrestore(&rq->lock, flags); |
bccbe08a | 8589 | } |
5f817d67 | 8590 | #else /* !CONFIG_FAIR_GROUP_SCHED */ |
bccbe08a PZ |
8591 | static inline void free_fair_sched_group(struct task_group *tg) |
8592 | { | |
8593 | } | |
8594 | ||
ec7dc8ac DG |
8595 | static inline |
8596 | int alloc_fair_sched_group(struct task_group *tg, struct task_group *parent) | |
bccbe08a PZ |
8597 | { |
8598 | return 1; | |
8599 | } | |
8600 | ||
bccbe08a PZ |
8601 | static inline void unregister_fair_sched_group(struct task_group *tg, int cpu) |
8602 | { | |
8603 | } | |
6d6bc0ad | 8604 | #endif /* CONFIG_FAIR_GROUP_SCHED */ |
052f1dc7 PZ |
8605 | |
8606 | #ifdef CONFIG_RT_GROUP_SCHED | |
bccbe08a PZ |
8607 | static void free_rt_sched_group(struct task_group *tg) |
8608 | { | |
8609 | int i; | |
8610 | ||
99bc5242 BL |
8611 | if (tg->rt_se) |
8612 | destroy_rt_bandwidth(&tg->rt_bandwidth); | |
d0b27fa7 | 8613 | |
bccbe08a PZ |
8614 | for_each_possible_cpu(i) { |
8615 | if (tg->rt_rq) | |
8616 | kfree(tg->rt_rq[i]); | |
8617 | if (tg->rt_se) | |
8618 | kfree(tg->rt_se[i]); | |
8619 | } | |
8620 | ||
8621 | kfree(tg->rt_rq); | |
8622 | kfree(tg->rt_se); | |
8623 | } | |
8624 | ||
ec7dc8ac DG |
8625 | static |
8626 | int alloc_rt_sched_group(struct task_group *tg, struct task_group *parent) | |
bccbe08a PZ |
8627 | { |
8628 | struct rt_rq *rt_rq; | |
eab17229 | 8629 | struct sched_rt_entity *rt_se; |
bccbe08a PZ |
8630 | int i; |
8631 | ||
434d53b0 | 8632 | tg->rt_rq = kzalloc(sizeof(rt_rq) * nr_cpu_ids, GFP_KERNEL); |
bccbe08a PZ |
8633 | if (!tg->rt_rq) |
8634 | goto err; | |
434d53b0 | 8635 | tg->rt_se = kzalloc(sizeof(rt_se) * nr_cpu_ids, GFP_KERNEL); |
bccbe08a PZ |
8636 | if (!tg->rt_se) |
8637 | goto err; | |
8638 | ||
d0b27fa7 PZ |
8639 | init_rt_bandwidth(&tg->rt_bandwidth, |
8640 | ktime_to_ns(def_rt_bandwidth.rt_period), 0); | |
bccbe08a PZ |
8641 | |
8642 | for_each_possible_cpu(i) { | |
eab17229 LZ |
8643 | rt_rq = kzalloc_node(sizeof(struct rt_rq), |
8644 | GFP_KERNEL, cpu_to_node(i)); | |
6f505b16 PZ |
8645 | if (!rt_rq) |
8646 | goto err; | |
29f59db3 | 8647 | |
eab17229 LZ |
8648 | rt_se = kzalloc_node(sizeof(struct sched_rt_entity), |
8649 | GFP_KERNEL, cpu_to_node(i)); | |
6f505b16 | 8650 | if (!rt_se) |
dfc12eb2 | 8651 | goto err_free_rq; |
29f59db3 | 8652 | |
acb5a9ba JS |
8653 | init_rt_rq(rt_rq, cpu_rq(i)); |
8654 | rt_rq->rt_runtime = tg->rt_bandwidth.rt_runtime; | |
3d4b47b4 | 8655 | init_tg_rt_entry(tg, rt_rq, rt_se, i, parent->rt_se[i]); |
29f59db3 SV |
8656 | } |
8657 | ||
bccbe08a PZ |
8658 | return 1; |
8659 | ||
49246274 | 8660 | err_free_rq: |
dfc12eb2 | 8661 | kfree(rt_rq); |
49246274 | 8662 | err: |
bccbe08a PZ |
8663 | return 0; |
8664 | } | |
6d6bc0ad | 8665 | #else /* !CONFIG_RT_GROUP_SCHED */ |
bccbe08a PZ |
8666 | static inline void free_rt_sched_group(struct task_group *tg) |
8667 | { | |
8668 | } | |
8669 | ||
ec7dc8ac DG |
8670 | static inline |
8671 | int alloc_rt_sched_group(struct task_group *tg, struct task_group *parent) | |
bccbe08a PZ |
8672 | { |
8673 | return 1; | |
8674 | } | |
6d6bc0ad | 8675 | #endif /* CONFIG_RT_GROUP_SCHED */ |
bccbe08a | 8676 | |
7c941438 | 8677 | #ifdef CONFIG_CGROUP_SCHED |
bccbe08a PZ |
8678 | static void free_sched_group(struct task_group *tg) |
8679 | { | |
8680 | free_fair_sched_group(tg); | |
8681 | free_rt_sched_group(tg); | |
e9aa1dd1 | 8682 | autogroup_free(tg); |
bccbe08a PZ |
8683 | kfree(tg); |
8684 | } | |
8685 | ||
8686 | /* allocate runqueue etc for a new task group */ | |
ec7dc8ac | 8687 | struct task_group *sched_create_group(struct task_group *parent) |
bccbe08a PZ |
8688 | { |
8689 | struct task_group *tg; | |
8690 | unsigned long flags; | |
bccbe08a PZ |
8691 | |
8692 | tg = kzalloc(sizeof(*tg), GFP_KERNEL); | |
8693 | if (!tg) | |
8694 | return ERR_PTR(-ENOMEM); | |
8695 | ||
ec7dc8ac | 8696 | if (!alloc_fair_sched_group(tg, parent)) |
bccbe08a PZ |
8697 | goto err; |
8698 | ||
ec7dc8ac | 8699 | if (!alloc_rt_sched_group(tg, parent)) |
bccbe08a PZ |
8700 | goto err; |
8701 | ||
8ed36996 | 8702 | spin_lock_irqsave(&task_group_lock, flags); |
6f505b16 | 8703 | list_add_rcu(&tg->list, &task_groups); |
f473aa5e PZ |
8704 | |
8705 | WARN_ON(!parent); /* root should already exist */ | |
8706 | ||
8707 | tg->parent = parent; | |
f473aa5e | 8708 | INIT_LIST_HEAD(&tg->children); |
09f2724a | 8709 | list_add_rcu(&tg->siblings, &parent->children); |
8ed36996 | 8710 | spin_unlock_irqrestore(&task_group_lock, flags); |
29f59db3 | 8711 | |
9b5b7751 | 8712 | return tg; |
29f59db3 SV |
8713 | |
8714 | err: | |
6f505b16 | 8715 | free_sched_group(tg); |
29f59db3 SV |
8716 | return ERR_PTR(-ENOMEM); |
8717 | } | |
8718 | ||
9b5b7751 | 8719 | /* rcu callback to free various structures associated with a task group */ |
6f505b16 | 8720 | static void free_sched_group_rcu(struct rcu_head *rhp) |
29f59db3 | 8721 | { |
29f59db3 | 8722 | /* now it should be safe to free those cfs_rqs */ |
6f505b16 | 8723 | free_sched_group(container_of(rhp, struct task_group, rcu)); |
29f59db3 SV |
8724 | } |
8725 | ||
9b5b7751 | 8726 | /* Destroy runqueue etc associated with a task group */ |
4cf86d77 | 8727 | void sched_destroy_group(struct task_group *tg) |
29f59db3 | 8728 | { |
8ed36996 | 8729 | unsigned long flags; |
9b5b7751 | 8730 | int i; |
29f59db3 | 8731 | |
3d4b47b4 PZ |
8732 | /* end participation in shares distribution */ |
8733 | for_each_possible_cpu(i) | |
bccbe08a | 8734 | unregister_fair_sched_group(tg, i); |
3d4b47b4 PZ |
8735 | |
8736 | spin_lock_irqsave(&task_group_lock, flags); | |
6f505b16 | 8737 | list_del_rcu(&tg->list); |
f473aa5e | 8738 | list_del_rcu(&tg->siblings); |
8ed36996 | 8739 | spin_unlock_irqrestore(&task_group_lock, flags); |
9b5b7751 | 8740 | |
9b5b7751 | 8741 | /* wait for possible concurrent references to cfs_rqs complete */ |
6f505b16 | 8742 | call_rcu(&tg->rcu, free_sched_group_rcu); |
29f59db3 SV |
8743 | } |
8744 | ||
9b5b7751 | 8745 | /* change task's runqueue when it moves between groups. |
3a252015 IM |
8746 | * The caller of this function should have put the task in its new group |
8747 | * by now. This function just updates tsk->se.cfs_rq and tsk->se.parent to | |
8748 | * reflect its new group. | |
9b5b7751 SV |
8749 | */ |
8750 | void sched_move_task(struct task_struct *tsk) | |
29f59db3 SV |
8751 | { |
8752 | int on_rq, running; | |
8753 | unsigned long flags; | |
8754 | struct rq *rq; | |
8755 | ||
8756 | rq = task_rq_lock(tsk, &flags); | |
8757 | ||
051a1d1a | 8758 | running = task_current(rq, tsk); |
fd2f4419 | 8759 | on_rq = tsk->on_rq; |
29f59db3 | 8760 | |
0e1f3483 | 8761 | if (on_rq) |
29f59db3 | 8762 | dequeue_task(rq, tsk, 0); |
0e1f3483 HS |
8763 | if (unlikely(running)) |
8764 | tsk->sched_class->put_prev_task(rq, tsk); | |
29f59db3 | 8765 | |
810b3817 | 8766 | #ifdef CONFIG_FAIR_GROUP_SCHED |
b2b5ce02 PZ |
8767 | if (tsk->sched_class->task_move_group) |
8768 | tsk->sched_class->task_move_group(tsk, on_rq); | |
8769 | else | |
810b3817 | 8770 | #endif |
b2b5ce02 | 8771 | set_task_rq(tsk, task_cpu(tsk)); |
810b3817 | 8772 | |
0e1f3483 HS |
8773 | if (unlikely(running)) |
8774 | tsk->sched_class->set_curr_task(rq); | |
8775 | if (on_rq) | |
371fd7e7 | 8776 | enqueue_task(rq, tsk, 0); |
29f59db3 | 8777 | |
0122ec5b | 8778 | task_rq_unlock(rq, tsk, &flags); |
29f59db3 | 8779 | } |
7c941438 | 8780 | #endif /* CONFIG_CGROUP_SCHED */ |
29f59db3 | 8781 | |
052f1dc7 | 8782 | #ifdef CONFIG_FAIR_GROUP_SCHED |
8ed36996 PZ |
8783 | static DEFINE_MUTEX(shares_mutex); |
8784 | ||
4cf86d77 | 8785 | int sched_group_set_shares(struct task_group *tg, unsigned long shares) |
29f59db3 SV |
8786 | { |
8787 | int i; | |
8ed36996 | 8788 | unsigned long flags; |
c61935fd | 8789 | |
ec7dc8ac DG |
8790 | /* |
8791 | * We can't change the weight of the root cgroup. | |
8792 | */ | |
8793 | if (!tg->se[0]) | |
8794 | return -EINVAL; | |
8795 | ||
cd62287e | 8796 | shares = clamp(shares, scale_load(MIN_SHARES), scale_load(MAX_SHARES)); |
62fb1851 | 8797 | |
8ed36996 | 8798 | mutex_lock(&shares_mutex); |
9b5b7751 | 8799 | if (tg->shares == shares) |
5cb350ba | 8800 | goto done; |
29f59db3 | 8801 | |
9b5b7751 | 8802 | tg->shares = shares; |
c09595f6 | 8803 | for_each_possible_cpu(i) { |
9437178f PT |
8804 | struct rq *rq = cpu_rq(i); |
8805 | struct sched_entity *se; | |
8806 | ||
8807 | se = tg->se[i]; | |
8808 | /* Propagate contribution to hierarchy */ | |
8809 | raw_spin_lock_irqsave(&rq->lock, flags); | |
8810 | for_each_sched_entity(se) | |
6d5ab293 | 8811 | update_cfs_shares(group_cfs_rq(se)); |
9437178f | 8812 | raw_spin_unlock_irqrestore(&rq->lock, flags); |
c09595f6 | 8813 | } |
29f59db3 | 8814 | |
5cb350ba | 8815 | done: |
8ed36996 | 8816 | mutex_unlock(&shares_mutex); |
9b5b7751 | 8817 | return 0; |
29f59db3 SV |
8818 | } |
8819 | ||
5cb350ba DG |
8820 | unsigned long sched_group_shares(struct task_group *tg) |
8821 | { | |
8822 | return tg->shares; | |
8823 | } | |
052f1dc7 | 8824 | #endif |
5cb350ba | 8825 | |
a790de99 | 8826 | #if defined(CONFIG_RT_GROUP_SCHED) || defined(CONFIG_CFS_BANDWIDTH) |
9f0c1e56 PZ |
8827 | static unsigned long to_ratio(u64 period, u64 runtime) |
8828 | { | |
8829 | if (runtime == RUNTIME_INF) | |
9a7e0b18 | 8830 | return 1ULL << 20; |
9f0c1e56 | 8831 | |
9a7e0b18 | 8832 | return div64_u64(runtime << 20, period); |
9f0c1e56 | 8833 | } |
a790de99 PT |
8834 | #endif |
8835 | ||
8836 | #ifdef CONFIG_RT_GROUP_SCHED | |
8837 | /* | |
8838 | * Ensure that the real time constraints are schedulable. | |
8839 | */ | |
8840 | static DEFINE_MUTEX(rt_constraints_mutex); | |
9f0c1e56 | 8841 | |
9a7e0b18 PZ |
8842 | /* Must be called with tasklist_lock held */ |
8843 | static inline int tg_has_rt_tasks(struct task_group *tg) | |
b40b2e8e | 8844 | { |
9a7e0b18 | 8845 | struct task_struct *g, *p; |
b40b2e8e | 8846 | |
9a7e0b18 PZ |
8847 | do_each_thread(g, p) { |
8848 | if (rt_task(p) && rt_rq_of_se(&p->rt)->tg == tg) | |
8849 | return 1; | |
8850 | } while_each_thread(g, p); | |
b40b2e8e | 8851 | |
9a7e0b18 PZ |
8852 | return 0; |
8853 | } | |
b40b2e8e | 8854 | |
9a7e0b18 PZ |
8855 | struct rt_schedulable_data { |
8856 | struct task_group *tg; | |
8857 | u64 rt_period; | |
8858 | u64 rt_runtime; | |
8859 | }; | |
b40b2e8e | 8860 | |
a790de99 | 8861 | static int tg_rt_schedulable(struct task_group *tg, void *data) |
9a7e0b18 PZ |
8862 | { |
8863 | struct rt_schedulable_data *d = data; | |
8864 | struct task_group *child; | |
8865 | unsigned long total, sum = 0; | |
8866 | u64 period, runtime; | |
b40b2e8e | 8867 | |
9a7e0b18 PZ |
8868 | period = ktime_to_ns(tg->rt_bandwidth.rt_period); |
8869 | runtime = tg->rt_bandwidth.rt_runtime; | |
b40b2e8e | 8870 | |
9a7e0b18 PZ |
8871 | if (tg == d->tg) { |
8872 | period = d->rt_period; | |
8873 | runtime = d->rt_runtime; | |
b40b2e8e | 8874 | } |
b40b2e8e | 8875 | |
4653f803 PZ |
8876 | /* |
8877 | * Cannot have more runtime than the period. | |
8878 | */ | |
8879 | if (runtime > period && runtime != RUNTIME_INF) | |
8880 | return -EINVAL; | |
6f505b16 | 8881 | |
4653f803 PZ |
8882 | /* |
8883 | * Ensure we don't starve existing RT tasks. | |
8884 | */ | |
9a7e0b18 PZ |
8885 | if (rt_bandwidth_enabled() && !runtime && tg_has_rt_tasks(tg)) |
8886 | return -EBUSY; | |
6f505b16 | 8887 | |
9a7e0b18 | 8888 | total = to_ratio(period, runtime); |
6f505b16 | 8889 | |
4653f803 PZ |
8890 | /* |
8891 | * Nobody can have more than the global setting allows. | |
8892 | */ | |
8893 | if (total > to_ratio(global_rt_period(), global_rt_runtime())) | |
8894 | return -EINVAL; | |
6f505b16 | 8895 | |
4653f803 PZ |
8896 | /* |
8897 | * The sum of our children's runtime should not exceed our own. | |
8898 | */ | |
9a7e0b18 PZ |
8899 | list_for_each_entry_rcu(child, &tg->children, siblings) { |
8900 | period = ktime_to_ns(child->rt_bandwidth.rt_period); | |
8901 | runtime = child->rt_bandwidth.rt_runtime; | |
6f505b16 | 8902 | |
9a7e0b18 PZ |
8903 | if (child == d->tg) { |
8904 | period = d->rt_period; | |
8905 | runtime = d->rt_runtime; | |
8906 | } | |
6f505b16 | 8907 | |
9a7e0b18 | 8908 | sum += to_ratio(period, runtime); |
9f0c1e56 | 8909 | } |
6f505b16 | 8910 | |
9a7e0b18 PZ |
8911 | if (sum > total) |
8912 | return -EINVAL; | |
8913 | ||
8914 | return 0; | |
6f505b16 PZ |
8915 | } |
8916 | ||
9a7e0b18 | 8917 | static int __rt_schedulable(struct task_group *tg, u64 period, u64 runtime) |
521f1a24 | 8918 | { |
8277434e PT |
8919 | int ret; |
8920 | ||
9a7e0b18 PZ |
8921 | struct rt_schedulable_data data = { |
8922 | .tg = tg, | |
8923 | .rt_period = period, | |
8924 | .rt_runtime = runtime, | |
8925 | }; | |
8926 | ||
8277434e PT |
8927 | rcu_read_lock(); |
8928 | ret = walk_tg_tree(tg_rt_schedulable, tg_nop, &data); | |
8929 | rcu_read_unlock(); | |
8930 | ||
8931 | return ret; | |
521f1a24 DG |
8932 | } |
8933 | ||
ab84d31e | 8934 | static int tg_set_rt_bandwidth(struct task_group *tg, |
d0b27fa7 | 8935 | u64 rt_period, u64 rt_runtime) |
6f505b16 | 8936 | { |
ac086bc2 | 8937 | int i, err = 0; |
9f0c1e56 | 8938 | |
9f0c1e56 | 8939 | mutex_lock(&rt_constraints_mutex); |
521f1a24 | 8940 | read_lock(&tasklist_lock); |
9a7e0b18 PZ |
8941 | err = __rt_schedulable(tg, rt_period, rt_runtime); |
8942 | if (err) | |
9f0c1e56 | 8943 | goto unlock; |
ac086bc2 | 8944 | |
0986b11b | 8945 | raw_spin_lock_irq(&tg->rt_bandwidth.rt_runtime_lock); |
d0b27fa7 PZ |
8946 | tg->rt_bandwidth.rt_period = ns_to_ktime(rt_period); |
8947 | tg->rt_bandwidth.rt_runtime = rt_runtime; | |
ac086bc2 PZ |
8948 | |
8949 | for_each_possible_cpu(i) { | |
8950 | struct rt_rq *rt_rq = tg->rt_rq[i]; | |
8951 | ||
0986b11b | 8952 | raw_spin_lock(&rt_rq->rt_runtime_lock); |
ac086bc2 | 8953 | rt_rq->rt_runtime = rt_runtime; |
0986b11b | 8954 | raw_spin_unlock(&rt_rq->rt_runtime_lock); |
ac086bc2 | 8955 | } |
0986b11b | 8956 | raw_spin_unlock_irq(&tg->rt_bandwidth.rt_runtime_lock); |
49246274 | 8957 | unlock: |
521f1a24 | 8958 | read_unlock(&tasklist_lock); |
9f0c1e56 PZ |
8959 | mutex_unlock(&rt_constraints_mutex); |
8960 | ||
8961 | return err; | |
6f505b16 PZ |
8962 | } |
8963 | ||
d0b27fa7 PZ |
8964 | int sched_group_set_rt_runtime(struct task_group *tg, long rt_runtime_us) |
8965 | { | |
8966 | u64 rt_runtime, rt_period; | |
8967 | ||
8968 | rt_period = ktime_to_ns(tg->rt_bandwidth.rt_period); | |
8969 | rt_runtime = (u64)rt_runtime_us * NSEC_PER_USEC; | |
8970 | if (rt_runtime_us < 0) | |
8971 | rt_runtime = RUNTIME_INF; | |
8972 | ||
ab84d31e | 8973 | return tg_set_rt_bandwidth(tg, rt_period, rt_runtime); |
d0b27fa7 PZ |
8974 | } |
8975 | ||
9f0c1e56 PZ |
8976 | long sched_group_rt_runtime(struct task_group *tg) |
8977 | { | |
8978 | u64 rt_runtime_us; | |
8979 | ||
d0b27fa7 | 8980 | if (tg->rt_bandwidth.rt_runtime == RUNTIME_INF) |
9f0c1e56 PZ |
8981 | return -1; |
8982 | ||
d0b27fa7 | 8983 | rt_runtime_us = tg->rt_bandwidth.rt_runtime; |
9f0c1e56 PZ |
8984 | do_div(rt_runtime_us, NSEC_PER_USEC); |
8985 | return rt_runtime_us; | |
8986 | } | |
d0b27fa7 PZ |
8987 | |
8988 | int sched_group_set_rt_period(struct task_group *tg, long rt_period_us) | |
8989 | { | |
8990 | u64 rt_runtime, rt_period; | |
8991 | ||
8992 | rt_period = (u64)rt_period_us * NSEC_PER_USEC; | |
8993 | rt_runtime = tg->rt_bandwidth.rt_runtime; | |
8994 | ||
619b0488 R |
8995 | if (rt_period == 0) |
8996 | return -EINVAL; | |
8997 | ||
ab84d31e | 8998 | return tg_set_rt_bandwidth(tg, rt_period, rt_runtime); |
d0b27fa7 PZ |
8999 | } |
9000 | ||
9001 | long sched_group_rt_period(struct task_group *tg) | |
9002 | { | |
9003 | u64 rt_period_us; | |
9004 | ||
9005 | rt_period_us = ktime_to_ns(tg->rt_bandwidth.rt_period); | |
9006 | do_div(rt_period_us, NSEC_PER_USEC); | |
9007 | return rt_period_us; | |
9008 | } | |
9009 | ||
9010 | static int sched_rt_global_constraints(void) | |
9011 | { | |
4653f803 | 9012 | u64 runtime, period; |
d0b27fa7 PZ |
9013 | int ret = 0; |
9014 | ||
ec5d4989 HS |
9015 | if (sysctl_sched_rt_period <= 0) |
9016 | return -EINVAL; | |
9017 | ||
4653f803 PZ |
9018 | runtime = global_rt_runtime(); |
9019 | period = global_rt_period(); | |
9020 | ||
9021 | /* | |
9022 | * Sanity check on the sysctl variables. | |
9023 | */ | |
9024 | if (runtime > period && runtime != RUNTIME_INF) | |
9025 | return -EINVAL; | |
10b612f4 | 9026 | |
d0b27fa7 | 9027 | mutex_lock(&rt_constraints_mutex); |
9a7e0b18 | 9028 | read_lock(&tasklist_lock); |
4653f803 | 9029 | ret = __rt_schedulable(NULL, 0, 0); |
9a7e0b18 | 9030 | read_unlock(&tasklist_lock); |
d0b27fa7 PZ |
9031 | mutex_unlock(&rt_constraints_mutex); |
9032 | ||
9033 | return ret; | |
9034 | } | |
54e99124 DG |
9035 | |
9036 | int sched_rt_can_attach(struct task_group *tg, struct task_struct *tsk) | |
9037 | { | |
9038 | /* Don't accept realtime tasks when there is no way for them to run */ | |
9039 | if (rt_task(tsk) && tg->rt_bandwidth.rt_runtime == 0) | |
9040 | return 0; | |
9041 | ||
9042 | return 1; | |
9043 | } | |
9044 | ||
6d6bc0ad | 9045 | #else /* !CONFIG_RT_GROUP_SCHED */ |
d0b27fa7 PZ |
9046 | static int sched_rt_global_constraints(void) |
9047 | { | |
ac086bc2 PZ |
9048 | unsigned long flags; |
9049 | int i; | |
9050 | ||
ec5d4989 HS |
9051 | if (sysctl_sched_rt_period <= 0) |
9052 | return -EINVAL; | |
9053 | ||
60aa605d PZ |
9054 | /* |
9055 | * There's always some RT tasks in the root group | |
9056 | * -- migration, kstopmachine etc.. | |
9057 | */ | |
9058 | if (sysctl_sched_rt_runtime == 0) | |
9059 | return -EBUSY; | |
9060 | ||
0986b11b | 9061 | raw_spin_lock_irqsave(&def_rt_bandwidth.rt_runtime_lock, flags); |
ac086bc2 PZ |
9062 | for_each_possible_cpu(i) { |
9063 | struct rt_rq *rt_rq = &cpu_rq(i)->rt; | |
9064 | ||
0986b11b | 9065 | raw_spin_lock(&rt_rq->rt_runtime_lock); |
ac086bc2 | 9066 | rt_rq->rt_runtime = global_rt_runtime(); |
0986b11b | 9067 | raw_spin_unlock(&rt_rq->rt_runtime_lock); |
ac086bc2 | 9068 | } |
0986b11b | 9069 | raw_spin_unlock_irqrestore(&def_rt_bandwidth.rt_runtime_lock, flags); |
ac086bc2 | 9070 | |
d0b27fa7 PZ |
9071 | return 0; |
9072 | } | |
6d6bc0ad | 9073 | #endif /* CONFIG_RT_GROUP_SCHED */ |
d0b27fa7 PZ |
9074 | |
9075 | int sched_rt_handler(struct ctl_table *table, int write, | |
8d65af78 | 9076 | void __user *buffer, size_t *lenp, |
d0b27fa7 PZ |
9077 | loff_t *ppos) |
9078 | { | |
9079 | int ret; | |
9080 | int old_period, old_runtime; | |
9081 | static DEFINE_MUTEX(mutex); | |
9082 | ||
9083 | mutex_lock(&mutex); | |
9084 | old_period = sysctl_sched_rt_period; | |
9085 | old_runtime = sysctl_sched_rt_runtime; | |
9086 | ||
8d65af78 | 9087 | ret = proc_dointvec(table, write, buffer, lenp, ppos); |
d0b27fa7 PZ |
9088 | |
9089 | if (!ret && write) { | |
9090 | ret = sched_rt_global_constraints(); | |
9091 | if (ret) { | |
9092 | sysctl_sched_rt_period = old_period; | |
9093 | sysctl_sched_rt_runtime = old_runtime; | |
9094 | } else { | |
9095 | def_rt_bandwidth.rt_runtime = global_rt_runtime(); | |
9096 | def_rt_bandwidth.rt_period = | |
9097 | ns_to_ktime(global_rt_period()); | |
9098 | } | |
9099 | } | |
9100 | mutex_unlock(&mutex); | |
9101 | ||
9102 | return ret; | |
9103 | } | |
68318b8e | 9104 | |
052f1dc7 | 9105 | #ifdef CONFIG_CGROUP_SCHED |
68318b8e SV |
9106 | |
9107 | /* return corresponding task_group object of a cgroup */ | |
2b01dfe3 | 9108 | static inline struct task_group *cgroup_tg(struct cgroup *cgrp) |
68318b8e | 9109 | { |
2b01dfe3 PM |
9110 | return container_of(cgroup_subsys_state(cgrp, cpu_cgroup_subsys_id), |
9111 | struct task_group, css); | |
68318b8e SV |
9112 | } |
9113 | ||
9114 | static struct cgroup_subsys_state * | |
2b01dfe3 | 9115 | cpu_cgroup_create(struct cgroup_subsys *ss, struct cgroup *cgrp) |
68318b8e | 9116 | { |
ec7dc8ac | 9117 | struct task_group *tg, *parent; |
68318b8e | 9118 | |
2b01dfe3 | 9119 | if (!cgrp->parent) { |
68318b8e | 9120 | /* This is early initialization for the top cgroup */ |
07e06b01 | 9121 | return &root_task_group.css; |
68318b8e SV |
9122 | } |
9123 | ||
ec7dc8ac DG |
9124 | parent = cgroup_tg(cgrp->parent); |
9125 | tg = sched_create_group(parent); | |
68318b8e SV |
9126 | if (IS_ERR(tg)) |
9127 | return ERR_PTR(-ENOMEM); | |
9128 | ||
68318b8e SV |
9129 | return &tg->css; |
9130 | } | |
9131 | ||
41a2d6cf IM |
9132 | static void |
9133 | cpu_cgroup_destroy(struct cgroup_subsys *ss, struct cgroup *cgrp) | |
68318b8e | 9134 | { |
2b01dfe3 | 9135 | struct task_group *tg = cgroup_tg(cgrp); |
68318b8e SV |
9136 | |
9137 | sched_destroy_group(tg); | |
9138 | } | |
9139 | ||
41a2d6cf | 9140 | static int |
be367d09 | 9141 | cpu_cgroup_can_attach_task(struct cgroup *cgrp, struct task_struct *tsk) |
68318b8e | 9142 | { |
b68aa230 | 9143 | #ifdef CONFIG_RT_GROUP_SCHED |
54e99124 | 9144 | if (!sched_rt_can_attach(cgroup_tg(cgrp), tsk)) |
b68aa230 PZ |
9145 | return -EINVAL; |
9146 | #else | |
68318b8e SV |
9147 | /* We don't support RT-tasks being in separate groups */ |
9148 | if (tsk->sched_class != &fair_sched_class) | |
9149 | return -EINVAL; | |
b68aa230 | 9150 | #endif |
be367d09 BB |
9151 | return 0; |
9152 | } | |
68318b8e | 9153 | |
68318b8e | 9154 | static void |
f780bdb7 | 9155 | cpu_cgroup_attach_task(struct cgroup *cgrp, struct task_struct *tsk) |
68318b8e SV |
9156 | { |
9157 | sched_move_task(tsk); | |
9158 | } | |
9159 | ||
068c5cc5 | 9160 | static void |
d41d5a01 PZ |
9161 | cpu_cgroup_exit(struct cgroup_subsys *ss, struct cgroup *cgrp, |
9162 | struct cgroup *old_cgrp, struct task_struct *task) | |
068c5cc5 PZ |
9163 | { |
9164 | /* | |
9165 | * cgroup_exit() is called in the copy_process() failure path. | |
9166 | * Ignore this case since the task hasn't ran yet, this avoids | |
9167 | * trying to poke a half freed task state from generic code. | |
9168 | */ | |
9169 | if (!(task->flags & PF_EXITING)) | |
9170 | return; | |
9171 | ||
9172 | sched_move_task(task); | |
9173 | } | |
9174 | ||
052f1dc7 | 9175 | #ifdef CONFIG_FAIR_GROUP_SCHED |
f4c753b7 | 9176 | static int cpu_shares_write_u64(struct cgroup *cgrp, struct cftype *cftype, |
2b01dfe3 | 9177 | u64 shareval) |
68318b8e | 9178 | { |
c8b28116 | 9179 | return sched_group_set_shares(cgroup_tg(cgrp), scale_load(shareval)); |
68318b8e SV |
9180 | } |
9181 | ||
f4c753b7 | 9182 | static u64 cpu_shares_read_u64(struct cgroup *cgrp, struct cftype *cft) |
68318b8e | 9183 | { |
2b01dfe3 | 9184 | struct task_group *tg = cgroup_tg(cgrp); |
68318b8e | 9185 | |
c8b28116 | 9186 | return (u64) scale_load_down(tg->shares); |
68318b8e | 9187 | } |
ab84d31e PT |
9188 | |
9189 | #ifdef CONFIG_CFS_BANDWIDTH | |
a790de99 PT |
9190 | static DEFINE_MUTEX(cfs_constraints_mutex); |
9191 | ||
ab84d31e PT |
9192 | const u64 max_cfs_quota_period = 1 * NSEC_PER_SEC; /* 1s */ |
9193 | const u64 min_cfs_quota_period = 1 * NSEC_PER_MSEC; /* 1ms */ | |
9194 | ||
a790de99 PT |
9195 | static int __cfs_schedulable(struct task_group *tg, u64 period, u64 runtime); |
9196 | ||
ab84d31e PT |
9197 | static int tg_set_cfs_bandwidth(struct task_group *tg, u64 period, u64 quota) |
9198 | { | |
58088ad0 | 9199 | int i, ret = 0, runtime_enabled; |
ab84d31e | 9200 | struct cfs_bandwidth *cfs_b = tg_cfs_bandwidth(tg); |
ab84d31e PT |
9201 | |
9202 | if (tg == &root_task_group) | |
9203 | return -EINVAL; | |
9204 | ||
9205 | /* | |
9206 | * Ensure we have at some amount of bandwidth every period. This is | |
9207 | * to prevent reaching a state of large arrears when throttled via | |
9208 | * entity_tick() resulting in prolonged exit starvation. | |
9209 | */ | |
9210 | if (quota < min_cfs_quota_period || period < min_cfs_quota_period) | |
9211 | return -EINVAL; | |
9212 | ||
9213 | /* | |
9214 | * Likewise, bound things on the otherside by preventing insane quota | |
9215 | * periods. This also allows us to normalize in computing quota | |
9216 | * feasibility. | |
9217 | */ | |
9218 | if (period > max_cfs_quota_period) | |
9219 | return -EINVAL; | |
9220 | ||
a790de99 PT |
9221 | mutex_lock(&cfs_constraints_mutex); |
9222 | ret = __cfs_schedulable(tg, period, quota); | |
9223 | if (ret) | |
9224 | goto out_unlock; | |
9225 | ||
58088ad0 | 9226 | runtime_enabled = quota != RUNTIME_INF; |
ab84d31e PT |
9227 | raw_spin_lock_irq(&cfs_b->lock); |
9228 | cfs_b->period = ns_to_ktime(period); | |
9229 | cfs_b->quota = quota; | |
58088ad0 | 9230 | |
a9cf55b2 | 9231 | __refill_cfs_bandwidth_runtime(cfs_b); |
58088ad0 PT |
9232 | /* restart the period timer (if active) to handle new period expiry */ |
9233 | if (runtime_enabled && cfs_b->timer_active) { | |
9234 | /* force a reprogram */ | |
9235 | cfs_b->timer_active = 0; | |
9236 | __start_cfs_bandwidth(cfs_b); | |
9237 | } | |
ab84d31e PT |
9238 | raw_spin_unlock_irq(&cfs_b->lock); |
9239 | ||
9240 | for_each_possible_cpu(i) { | |
9241 | struct cfs_rq *cfs_rq = tg->cfs_rq[i]; | |
9242 | struct rq *rq = rq_of(cfs_rq); | |
9243 | ||
9244 | raw_spin_lock_irq(&rq->lock); | |
58088ad0 | 9245 | cfs_rq->runtime_enabled = runtime_enabled; |
ab84d31e | 9246 | cfs_rq->runtime_remaining = 0; |
671fd9da PT |
9247 | |
9248 | if (cfs_rq_throttled(cfs_rq)) | |
9249 | unthrottle_cfs_rq(cfs_rq); | |
ab84d31e PT |
9250 | raw_spin_unlock_irq(&rq->lock); |
9251 | } | |
a790de99 PT |
9252 | out_unlock: |
9253 | mutex_unlock(&cfs_constraints_mutex); | |
ab84d31e | 9254 | |
a790de99 | 9255 | return ret; |
ab84d31e PT |
9256 | } |
9257 | ||
9258 | int tg_set_cfs_quota(struct task_group *tg, long cfs_quota_us) | |
9259 | { | |
9260 | u64 quota, period; | |
9261 | ||
9262 | period = ktime_to_ns(tg_cfs_bandwidth(tg)->period); | |
9263 | if (cfs_quota_us < 0) | |
9264 | quota = RUNTIME_INF; | |
9265 | else | |
9266 | quota = (u64)cfs_quota_us * NSEC_PER_USEC; | |
9267 | ||
9268 | return tg_set_cfs_bandwidth(tg, period, quota); | |
9269 | } | |
9270 | ||
9271 | long tg_get_cfs_quota(struct task_group *tg) | |
9272 | { | |
9273 | u64 quota_us; | |
9274 | ||
9275 | if (tg_cfs_bandwidth(tg)->quota == RUNTIME_INF) | |
9276 | return -1; | |
9277 | ||
9278 | quota_us = tg_cfs_bandwidth(tg)->quota; | |
9279 | do_div(quota_us, NSEC_PER_USEC); | |
9280 | ||
9281 | return quota_us; | |
9282 | } | |
9283 | ||
9284 | int tg_set_cfs_period(struct task_group *tg, long cfs_period_us) | |
9285 | { | |
9286 | u64 quota, period; | |
9287 | ||
9288 | period = (u64)cfs_period_us * NSEC_PER_USEC; | |
9289 | quota = tg_cfs_bandwidth(tg)->quota; | |
9290 | ||
9291 | if (period <= 0) | |
9292 | return -EINVAL; | |
9293 | ||
9294 | return tg_set_cfs_bandwidth(tg, period, quota); | |
9295 | } | |
9296 | ||
9297 | long tg_get_cfs_period(struct task_group *tg) | |
9298 | { | |
9299 | u64 cfs_period_us; | |
9300 | ||
9301 | cfs_period_us = ktime_to_ns(tg_cfs_bandwidth(tg)->period); | |
9302 | do_div(cfs_period_us, NSEC_PER_USEC); | |
9303 | ||
9304 | return cfs_period_us; | |
9305 | } | |
9306 | ||
9307 | static s64 cpu_cfs_quota_read_s64(struct cgroup *cgrp, struct cftype *cft) | |
9308 | { | |
9309 | return tg_get_cfs_quota(cgroup_tg(cgrp)); | |
9310 | } | |
9311 | ||
9312 | static int cpu_cfs_quota_write_s64(struct cgroup *cgrp, struct cftype *cftype, | |
9313 | s64 cfs_quota_us) | |
9314 | { | |
9315 | return tg_set_cfs_quota(cgroup_tg(cgrp), cfs_quota_us); | |
9316 | } | |
9317 | ||
9318 | static u64 cpu_cfs_period_read_u64(struct cgroup *cgrp, struct cftype *cft) | |
9319 | { | |
9320 | return tg_get_cfs_period(cgroup_tg(cgrp)); | |
9321 | } | |
9322 | ||
9323 | static int cpu_cfs_period_write_u64(struct cgroup *cgrp, struct cftype *cftype, | |
9324 | u64 cfs_period_us) | |
9325 | { | |
9326 | return tg_set_cfs_period(cgroup_tg(cgrp), cfs_period_us); | |
9327 | } | |
9328 | ||
a790de99 PT |
9329 | struct cfs_schedulable_data { |
9330 | struct task_group *tg; | |
9331 | u64 period, quota; | |
9332 | }; | |
9333 | ||
9334 | /* | |
9335 | * normalize group quota/period to be quota/max_period | |
9336 | * note: units are usecs | |
9337 | */ | |
9338 | static u64 normalize_cfs_quota(struct task_group *tg, | |
9339 | struct cfs_schedulable_data *d) | |
9340 | { | |
9341 | u64 quota, period; | |
9342 | ||
9343 | if (tg == d->tg) { | |
9344 | period = d->period; | |
9345 | quota = d->quota; | |
9346 | } else { | |
9347 | period = tg_get_cfs_period(tg); | |
9348 | quota = tg_get_cfs_quota(tg); | |
9349 | } | |
9350 | ||
9351 | /* note: these should typically be equivalent */ | |
9352 | if (quota == RUNTIME_INF || quota == -1) | |
9353 | return RUNTIME_INF; | |
9354 | ||
9355 | return to_ratio(period, quota); | |
9356 | } | |
9357 | ||
9358 | static int tg_cfs_schedulable_down(struct task_group *tg, void *data) | |
9359 | { | |
9360 | struct cfs_schedulable_data *d = data; | |
9361 | struct cfs_bandwidth *cfs_b = tg_cfs_bandwidth(tg); | |
9362 | s64 quota = 0, parent_quota = -1; | |
9363 | ||
9364 | if (!tg->parent) { | |
9365 | quota = RUNTIME_INF; | |
9366 | } else { | |
9367 | struct cfs_bandwidth *parent_b = tg_cfs_bandwidth(tg->parent); | |
9368 | ||
9369 | quota = normalize_cfs_quota(tg, d); | |
9370 | parent_quota = parent_b->hierarchal_quota; | |
9371 | ||
9372 | /* | |
9373 | * ensure max(child_quota) <= parent_quota, inherit when no | |
9374 | * limit is set | |
9375 | */ | |
9376 | if (quota == RUNTIME_INF) | |
9377 | quota = parent_quota; | |
9378 | else if (parent_quota != RUNTIME_INF && quota > parent_quota) | |
9379 | return -EINVAL; | |
9380 | } | |
9381 | cfs_b->hierarchal_quota = quota; | |
9382 | ||
9383 | return 0; | |
9384 | } | |
9385 | ||
9386 | static int __cfs_schedulable(struct task_group *tg, u64 period, u64 quota) | |
9387 | { | |
8277434e | 9388 | int ret; |
a790de99 PT |
9389 | struct cfs_schedulable_data data = { |
9390 | .tg = tg, | |
9391 | .period = period, | |
9392 | .quota = quota, | |
9393 | }; | |
9394 | ||
9395 | if (quota != RUNTIME_INF) { | |
9396 | do_div(data.period, NSEC_PER_USEC); | |
9397 | do_div(data.quota, NSEC_PER_USEC); | |
9398 | } | |
9399 | ||
8277434e PT |
9400 | rcu_read_lock(); |
9401 | ret = walk_tg_tree(tg_cfs_schedulable_down, tg_nop, &data); | |
9402 | rcu_read_unlock(); | |
9403 | ||
9404 | return ret; | |
a790de99 | 9405 | } |
e8da1b18 NR |
9406 | |
9407 | static int cpu_stats_show(struct cgroup *cgrp, struct cftype *cft, | |
9408 | struct cgroup_map_cb *cb) | |
9409 | { | |
9410 | struct task_group *tg = cgroup_tg(cgrp); | |
9411 | struct cfs_bandwidth *cfs_b = tg_cfs_bandwidth(tg); | |
9412 | ||
9413 | cb->fill(cb, "nr_periods", cfs_b->nr_periods); | |
9414 | cb->fill(cb, "nr_throttled", cfs_b->nr_throttled); | |
9415 | cb->fill(cb, "throttled_time", cfs_b->throttled_time); | |
9416 | ||
9417 | return 0; | |
9418 | } | |
ab84d31e | 9419 | #endif /* CONFIG_CFS_BANDWIDTH */ |
6d6bc0ad | 9420 | #endif /* CONFIG_FAIR_GROUP_SCHED */ |
68318b8e | 9421 | |
052f1dc7 | 9422 | #ifdef CONFIG_RT_GROUP_SCHED |
0c70814c | 9423 | static int cpu_rt_runtime_write(struct cgroup *cgrp, struct cftype *cft, |
06ecb27c | 9424 | s64 val) |
6f505b16 | 9425 | { |
06ecb27c | 9426 | return sched_group_set_rt_runtime(cgroup_tg(cgrp), val); |
6f505b16 PZ |
9427 | } |
9428 | ||
06ecb27c | 9429 | static s64 cpu_rt_runtime_read(struct cgroup *cgrp, struct cftype *cft) |
6f505b16 | 9430 | { |
06ecb27c | 9431 | return sched_group_rt_runtime(cgroup_tg(cgrp)); |
6f505b16 | 9432 | } |
d0b27fa7 PZ |
9433 | |
9434 | static int cpu_rt_period_write_uint(struct cgroup *cgrp, struct cftype *cftype, | |
9435 | u64 rt_period_us) | |
9436 | { | |
9437 | return sched_group_set_rt_period(cgroup_tg(cgrp), rt_period_us); | |
9438 | } | |
9439 | ||
9440 | static u64 cpu_rt_period_read_uint(struct cgroup *cgrp, struct cftype *cft) | |
9441 | { | |
9442 | return sched_group_rt_period(cgroup_tg(cgrp)); | |
9443 | } | |
6d6bc0ad | 9444 | #endif /* CONFIG_RT_GROUP_SCHED */ |
6f505b16 | 9445 | |
fe5c7cc2 | 9446 | static struct cftype cpu_files[] = { |
052f1dc7 | 9447 | #ifdef CONFIG_FAIR_GROUP_SCHED |
fe5c7cc2 PM |
9448 | { |
9449 | .name = "shares", | |
f4c753b7 PM |
9450 | .read_u64 = cpu_shares_read_u64, |
9451 | .write_u64 = cpu_shares_write_u64, | |
fe5c7cc2 | 9452 | }, |
052f1dc7 | 9453 | #endif |
ab84d31e PT |
9454 | #ifdef CONFIG_CFS_BANDWIDTH |
9455 | { | |
9456 | .name = "cfs_quota_us", | |
9457 | .read_s64 = cpu_cfs_quota_read_s64, | |
9458 | .write_s64 = cpu_cfs_quota_write_s64, | |
9459 | }, | |
9460 | { | |
9461 | .name = "cfs_period_us", | |
9462 | .read_u64 = cpu_cfs_period_read_u64, | |
9463 | .write_u64 = cpu_cfs_period_write_u64, | |
9464 | }, | |
e8da1b18 NR |
9465 | { |
9466 | .name = "stat", | |
9467 | .read_map = cpu_stats_show, | |
9468 | }, | |
ab84d31e | 9469 | #endif |
052f1dc7 | 9470 | #ifdef CONFIG_RT_GROUP_SCHED |
6f505b16 | 9471 | { |
9f0c1e56 | 9472 | .name = "rt_runtime_us", |
06ecb27c PM |
9473 | .read_s64 = cpu_rt_runtime_read, |
9474 | .write_s64 = cpu_rt_runtime_write, | |
6f505b16 | 9475 | }, |
d0b27fa7 PZ |
9476 | { |
9477 | .name = "rt_period_us", | |
f4c753b7 PM |
9478 | .read_u64 = cpu_rt_period_read_uint, |
9479 | .write_u64 = cpu_rt_period_write_uint, | |
d0b27fa7 | 9480 | }, |
052f1dc7 | 9481 | #endif |
68318b8e SV |
9482 | }; |
9483 | ||
9484 | static int cpu_cgroup_populate(struct cgroup_subsys *ss, struct cgroup *cont) | |
9485 | { | |
fe5c7cc2 | 9486 | return cgroup_add_files(cont, ss, cpu_files, ARRAY_SIZE(cpu_files)); |
68318b8e SV |
9487 | } |
9488 | ||
9489 | struct cgroup_subsys cpu_cgroup_subsys = { | |
38605cae IM |
9490 | .name = "cpu", |
9491 | .create = cpu_cgroup_create, | |
9492 | .destroy = cpu_cgroup_destroy, | |
f780bdb7 BB |
9493 | .can_attach_task = cpu_cgroup_can_attach_task, |
9494 | .attach_task = cpu_cgroup_attach_task, | |
068c5cc5 | 9495 | .exit = cpu_cgroup_exit, |
38605cae IM |
9496 | .populate = cpu_cgroup_populate, |
9497 | .subsys_id = cpu_cgroup_subsys_id, | |
68318b8e SV |
9498 | .early_init = 1, |
9499 | }; | |
9500 | ||
052f1dc7 | 9501 | #endif /* CONFIG_CGROUP_SCHED */ |
d842de87 SV |
9502 | |
9503 | #ifdef CONFIG_CGROUP_CPUACCT | |
9504 | ||
9505 | /* | |
9506 | * CPU accounting code for task groups. | |
9507 | * | |
9508 | * Based on the work by Paul Menage (menage@google.com) and Balbir Singh | |
9509 | * (balbir@in.ibm.com). | |
9510 | */ | |
9511 | ||
934352f2 | 9512 | /* track cpu usage of a group of tasks and its child groups */ |
d842de87 SV |
9513 | struct cpuacct { |
9514 | struct cgroup_subsys_state css; | |
9515 | /* cpuusage holds pointer to a u64-type object on every cpu */ | |
43cf38eb | 9516 | u64 __percpu *cpuusage; |
ef12fefa | 9517 | struct percpu_counter cpustat[CPUACCT_STAT_NSTATS]; |
934352f2 | 9518 | struct cpuacct *parent; |
d842de87 SV |
9519 | }; |
9520 | ||
9521 | struct cgroup_subsys cpuacct_subsys; | |
9522 | ||
9523 | /* return cpu accounting group corresponding to this container */ | |
32cd756a | 9524 | static inline struct cpuacct *cgroup_ca(struct cgroup *cgrp) |
d842de87 | 9525 | { |
32cd756a | 9526 | return container_of(cgroup_subsys_state(cgrp, cpuacct_subsys_id), |
d842de87 SV |
9527 | struct cpuacct, css); |
9528 | } | |
9529 | ||
9530 | /* return cpu accounting group to which this task belongs */ | |
9531 | static inline struct cpuacct *task_ca(struct task_struct *tsk) | |
9532 | { | |
9533 | return container_of(task_subsys_state(tsk, cpuacct_subsys_id), | |
9534 | struct cpuacct, css); | |
9535 | } | |
9536 | ||
9537 | /* create a new cpu accounting group */ | |
9538 | static struct cgroup_subsys_state *cpuacct_create( | |
32cd756a | 9539 | struct cgroup_subsys *ss, struct cgroup *cgrp) |
d842de87 SV |
9540 | { |
9541 | struct cpuacct *ca = kzalloc(sizeof(*ca), GFP_KERNEL); | |
ef12fefa | 9542 | int i; |
d842de87 SV |
9543 | |
9544 | if (!ca) | |
ef12fefa | 9545 | goto out; |
d842de87 SV |
9546 | |
9547 | ca->cpuusage = alloc_percpu(u64); | |
ef12fefa BR |
9548 | if (!ca->cpuusage) |
9549 | goto out_free_ca; | |
9550 | ||
9551 | for (i = 0; i < CPUACCT_STAT_NSTATS; i++) | |
9552 | if (percpu_counter_init(&ca->cpustat[i], 0)) | |
9553 | goto out_free_counters; | |
d842de87 | 9554 | |
934352f2 BR |
9555 | if (cgrp->parent) |
9556 | ca->parent = cgroup_ca(cgrp->parent); | |
9557 | ||
d842de87 | 9558 | return &ca->css; |
ef12fefa BR |
9559 | |
9560 | out_free_counters: | |
9561 | while (--i >= 0) | |
9562 | percpu_counter_destroy(&ca->cpustat[i]); | |
9563 | free_percpu(ca->cpuusage); | |
9564 | out_free_ca: | |
9565 | kfree(ca); | |
9566 | out: | |
9567 | return ERR_PTR(-ENOMEM); | |
d842de87 SV |
9568 | } |
9569 | ||
9570 | /* destroy an existing cpu accounting group */ | |
41a2d6cf | 9571 | static void |
32cd756a | 9572 | cpuacct_destroy(struct cgroup_subsys *ss, struct cgroup *cgrp) |
d842de87 | 9573 | { |
32cd756a | 9574 | struct cpuacct *ca = cgroup_ca(cgrp); |
ef12fefa | 9575 | int i; |
d842de87 | 9576 | |
ef12fefa BR |
9577 | for (i = 0; i < CPUACCT_STAT_NSTATS; i++) |
9578 | percpu_counter_destroy(&ca->cpustat[i]); | |
d842de87 SV |
9579 | free_percpu(ca->cpuusage); |
9580 | kfree(ca); | |
9581 | } | |
9582 | ||
720f5498 KC |
9583 | static u64 cpuacct_cpuusage_read(struct cpuacct *ca, int cpu) |
9584 | { | |
b36128c8 | 9585 | u64 *cpuusage = per_cpu_ptr(ca->cpuusage, cpu); |
720f5498 KC |
9586 | u64 data; |
9587 | ||
9588 | #ifndef CONFIG_64BIT | |
9589 | /* | |
9590 | * Take rq->lock to make 64-bit read safe on 32-bit platforms. | |
9591 | */ | |
05fa785c | 9592 | raw_spin_lock_irq(&cpu_rq(cpu)->lock); |
720f5498 | 9593 | data = *cpuusage; |
05fa785c | 9594 | raw_spin_unlock_irq(&cpu_rq(cpu)->lock); |
720f5498 KC |
9595 | #else |
9596 | data = *cpuusage; | |
9597 | #endif | |
9598 | ||
9599 | return data; | |
9600 | } | |
9601 | ||
9602 | static void cpuacct_cpuusage_write(struct cpuacct *ca, int cpu, u64 val) | |
9603 | { | |
b36128c8 | 9604 | u64 *cpuusage = per_cpu_ptr(ca->cpuusage, cpu); |
720f5498 KC |
9605 | |
9606 | #ifndef CONFIG_64BIT | |
9607 | /* | |
9608 | * Take rq->lock to make 64-bit write safe on 32-bit platforms. | |
9609 | */ | |
05fa785c | 9610 | raw_spin_lock_irq(&cpu_rq(cpu)->lock); |
720f5498 | 9611 | *cpuusage = val; |
05fa785c | 9612 | raw_spin_unlock_irq(&cpu_rq(cpu)->lock); |
720f5498 KC |
9613 | #else |
9614 | *cpuusage = val; | |
9615 | #endif | |
9616 | } | |
9617 | ||
d842de87 | 9618 | /* return total cpu usage (in nanoseconds) of a group */ |
32cd756a | 9619 | static u64 cpuusage_read(struct cgroup *cgrp, struct cftype *cft) |
d842de87 | 9620 | { |
32cd756a | 9621 | struct cpuacct *ca = cgroup_ca(cgrp); |
d842de87 SV |
9622 | u64 totalcpuusage = 0; |
9623 | int i; | |
9624 | ||
720f5498 KC |
9625 | for_each_present_cpu(i) |
9626 | totalcpuusage += cpuacct_cpuusage_read(ca, i); | |
d842de87 SV |
9627 | |
9628 | return totalcpuusage; | |
9629 | } | |
9630 | ||
0297b803 DG |
9631 | static int cpuusage_write(struct cgroup *cgrp, struct cftype *cftype, |
9632 | u64 reset) | |
9633 | { | |
9634 | struct cpuacct *ca = cgroup_ca(cgrp); | |
9635 | int err = 0; | |
9636 | int i; | |
9637 | ||
9638 | if (reset) { | |
9639 | err = -EINVAL; | |
9640 | goto out; | |
9641 | } | |
9642 | ||
720f5498 KC |
9643 | for_each_present_cpu(i) |
9644 | cpuacct_cpuusage_write(ca, i, 0); | |
0297b803 | 9645 | |
0297b803 DG |
9646 | out: |
9647 | return err; | |
9648 | } | |
9649 | ||
e9515c3c KC |
9650 | static int cpuacct_percpu_seq_read(struct cgroup *cgroup, struct cftype *cft, |
9651 | struct seq_file *m) | |
9652 | { | |
9653 | struct cpuacct *ca = cgroup_ca(cgroup); | |
9654 | u64 percpu; | |
9655 | int i; | |
9656 | ||
9657 | for_each_present_cpu(i) { | |
9658 | percpu = cpuacct_cpuusage_read(ca, i); | |
9659 | seq_printf(m, "%llu ", (unsigned long long) percpu); | |
9660 | } | |
9661 | seq_printf(m, "\n"); | |
9662 | return 0; | |
9663 | } | |
9664 | ||
ef12fefa BR |
9665 | static const char *cpuacct_stat_desc[] = { |
9666 | [CPUACCT_STAT_USER] = "user", | |
9667 | [CPUACCT_STAT_SYSTEM] = "system", | |
9668 | }; | |
9669 | ||
9670 | static int cpuacct_stats_show(struct cgroup *cgrp, struct cftype *cft, | |
9671 | struct cgroup_map_cb *cb) | |
9672 | { | |
9673 | struct cpuacct *ca = cgroup_ca(cgrp); | |
9674 | int i; | |
9675 | ||
9676 | for (i = 0; i < CPUACCT_STAT_NSTATS; i++) { | |
9677 | s64 val = percpu_counter_read(&ca->cpustat[i]); | |
9678 | val = cputime64_to_clock_t(val); | |
9679 | cb->fill(cb, cpuacct_stat_desc[i], val); | |
9680 | } | |
9681 | return 0; | |
9682 | } | |
9683 | ||
d842de87 SV |
9684 | static struct cftype files[] = { |
9685 | { | |
9686 | .name = "usage", | |
f4c753b7 PM |
9687 | .read_u64 = cpuusage_read, |
9688 | .write_u64 = cpuusage_write, | |
d842de87 | 9689 | }, |
e9515c3c KC |
9690 | { |
9691 | .name = "usage_percpu", | |
9692 | .read_seq_string = cpuacct_percpu_seq_read, | |
9693 | }, | |
ef12fefa BR |
9694 | { |
9695 | .name = "stat", | |
9696 | .read_map = cpuacct_stats_show, | |
9697 | }, | |
d842de87 SV |
9698 | }; |
9699 | ||
32cd756a | 9700 | static int cpuacct_populate(struct cgroup_subsys *ss, struct cgroup *cgrp) |
d842de87 | 9701 | { |
32cd756a | 9702 | return cgroup_add_files(cgrp, ss, files, ARRAY_SIZE(files)); |
d842de87 SV |
9703 | } |
9704 | ||
9705 | /* | |
9706 | * charge this task's execution time to its accounting group. | |
9707 | * | |
9708 | * called with rq->lock held. | |
9709 | */ | |
9710 | static void cpuacct_charge(struct task_struct *tsk, u64 cputime) | |
9711 | { | |
9712 | struct cpuacct *ca; | |
934352f2 | 9713 | int cpu; |
d842de87 | 9714 | |
c40c6f85 | 9715 | if (unlikely(!cpuacct_subsys.active)) |
d842de87 SV |
9716 | return; |
9717 | ||
934352f2 | 9718 | cpu = task_cpu(tsk); |
a18b83b7 BR |
9719 | |
9720 | rcu_read_lock(); | |
9721 | ||
d842de87 | 9722 | ca = task_ca(tsk); |
d842de87 | 9723 | |
934352f2 | 9724 | for (; ca; ca = ca->parent) { |
b36128c8 | 9725 | u64 *cpuusage = per_cpu_ptr(ca->cpuusage, cpu); |
d842de87 SV |
9726 | *cpuusage += cputime; |
9727 | } | |
a18b83b7 BR |
9728 | |
9729 | rcu_read_unlock(); | |
d842de87 SV |
9730 | } |
9731 | ||
fa535a77 AB |
9732 | /* |
9733 | * When CONFIG_VIRT_CPU_ACCOUNTING is enabled one jiffy can be very large | |
9734 | * in cputime_t units. As a result, cpuacct_update_stats calls | |
9735 | * percpu_counter_add with values large enough to always overflow the | |
9736 | * per cpu batch limit causing bad SMP scalability. | |
9737 | * | |
9738 | * To fix this we scale percpu_counter_batch by cputime_one_jiffy so we | |
9739 | * batch the same amount of time with CONFIG_VIRT_CPU_ACCOUNTING disabled | |
9740 | * and enabled. We cap it at INT_MAX which is the largest allowed batch value. | |
9741 | */ | |
9742 | #ifdef CONFIG_SMP | |
9743 | #define CPUACCT_BATCH \ | |
9744 | min_t(long, percpu_counter_batch * cputime_one_jiffy, INT_MAX) | |
9745 | #else | |
9746 | #define CPUACCT_BATCH 0 | |
9747 | #endif | |
9748 | ||
ef12fefa BR |
9749 | /* |
9750 | * Charge the system/user time to the task's accounting group. | |
9751 | */ | |
9752 | static void cpuacct_update_stats(struct task_struct *tsk, | |
9753 | enum cpuacct_stat_index idx, cputime_t val) | |
9754 | { | |
9755 | struct cpuacct *ca; | |
fa535a77 | 9756 | int batch = CPUACCT_BATCH; |
ef12fefa BR |
9757 | |
9758 | if (unlikely(!cpuacct_subsys.active)) | |
9759 | return; | |
9760 | ||
9761 | rcu_read_lock(); | |
9762 | ca = task_ca(tsk); | |
9763 | ||
9764 | do { | |
fa535a77 | 9765 | __percpu_counter_add(&ca->cpustat[idx], val, batch); |
ef12fefa BR |
9766 | ca = ca->parent; |
9767 | } while (ca); | |
9768 | rcu_read_unlock(); | |
9769 | } | |
9770 | ||
d842de87 SV |
9771 | struct cgroup_subsys cpuacct_subsys = { |
9772 | .name = "cpuacct", | |
9773 | .create = cpuacct_create, | |
9774 | .destroy = cpuacct_destroy, | |
9775 | .populate = cpuacct_populate, | |
9776 | .subsys_id = cpuacct_subsys_id, | |
9777 | }; | |
9778 | #endif /* CONFIG_CGROUP_CPUACCT */ |