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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> |
f1c6f1a7 | 74 | #include <linux/init_task.h> |
1da177e4 | 75 | |
5517d86b | 76 | #include <asm/tlb.h> |
838225b4 | 77 | #include <asm/irq_regs.h> |
335d7afb | 78 | #include <asm/mutex.h> |
e6e6685a GC |
79 | #ifdef CONFIG_PARAVIRT |
80 | #include <asm/paravirt.h> | |
81 | #endif | |
1da177e4 | 82 | |
6e0534f2 | 83 | #include "sched_cpupri.h" |
21aa9af0 | 84 | #include "workqueue_sched.h" |
5091faa4 | 85 | #include "sched_autogroup.h" |
6e0534f2 | 86 | |
a8d154b0 | 87 | #define CREATE_TRACE_POINTS |
ad8d75ff | 88 | #include <trace/events/sched.h> |
a8d154b0 | 89 | |
1da177e4 LT |
90 | /* |
91 | * Convert user-nice values [ -20 ... 0 ... 19 ] | |
92 | * to static priority [ MAX_RT_PRIO..MAX_PRIO-1 ], | |
93 | * and back. | |
94 | */ | |
95 | #define NICE_TO_PRIO(nice) (MAX_RT_PRIO + (nice) + 20) | |
96 | #define PRIO_TO_NICE(prio) ((prio) - MAX_RT_PRIO - 20) | |
97 | #define TASK_NICE(p) PRIO_TO_NICE((p)->static_prio) | |
98 | ||
99 | /* | |
100 | * 'User priority' is the nice value converted to something we | |
101 | * can work with better when scaling various scheduler parameters, | |
102 | * it's a [ 0 ... 39 ] range. | |
103 | */ | |
104 | #define USER_PRIO(p) ((p)-MAX_RT_PRIO) | |
105 | #define TASK_USER_PRIO(p) USER_PRIO((p)->static_prio) | |
106 | #define MAX_USER_PRIO (USER_PRIO(MAX_PRIO)) | |
107 | ||
108 | /* | |
d7876a08 | 109 | * Helpers for converting nanosecond timing to jiffy resolution |
1da177e4 | 110 | */ |
d6322faf | 111 | #define NS_TO_JIFFIES(TIME) ((unsigned long)(TIME) / (NSEC_PER_SEC / HZ)) |
1da177e4 | 112 | |
6aa645ea IM |
113 | #define NICE_0_LOAD SCHED_LOAD_SCALE |
114 | #define NICE_0_SHIFT SCHED_LOAD_SHIFT | |
115 | ||
1da177e4 LT |
116 | /* |
117 | * These are the 'tuning knobs' of the scheduler: | |
118 | * | |
a4ec24b4 | 119 | * default timeslice is 100 msecs (used only for SCHED_RR tasks). |
1da177e4 LT |
120 | * Timeslices get refilled after they expire. |
121 | */ | |
1da177e4 | 122 | #define DEF_TIMESLICE (100 * HZ / 1000) |
2dd73a4f | 123 | |
d0b27fa7 PZ |
124 | /* |
125 | * single value that denotes runtime == period, ie unlimited time. | |
126 | */ | |
127 | #define RUNTIME_INF ((u64)~0ULL) | |
128 | ||
e05606d3 IM |
129 | static inline int rt_policy(int policy) |
130 | { | |
63f01241 | 131 | if (policy == SCHED_FIFO || policy == SCHED_RR) |
e05606d3 IM |
132 | return 1; |
133 | return 0; | |
134 | } | |
135 | ||
136 | static inline int task_has_rt_policy(struct task_struct *p) | |
137 | { | |
138 | return rt_policy(p->policy); | |
139 | } | |
140 | ||
1da177e4 | 141 | /* |
6aa645ea | 142 | * This is the priority-queue data structure of the RT scheduling class: |
1da177e4 | 143 | */ |
6aa645ea IM |
144 | struct rt_prio_array { |
145 | DECLARE_BITMAP(bitmap, MAX_RT_PRIO+1); /* include 1 bit for delimiter */ | |
146 | struct list_head queue[MAX_RT_PRIO]; | |
147 | }; | |
148 | ||
d0b27fa7 | 149 | struct rt_bandwidth { |
ea736ed5 | 150 | /* nests inside the rq lock: */ |
0986b11b | 151 | raw_spinlock_t rt_runtime_lock; |
ea736ed5 IM |
152 | ktime_t rt_period; |
153 | u64 rt_runtime; | |
154 | struct hrtimer rt_period_timer; | |
d0b27fa7 PZ |
155 | }; |
156 | ||
157 | static struct rt_bandwidth def_rt_bandwidth; | |
158 | ||
159 | static int do_sched_rt_period_timer(struct rt_bandwidth *rt_b, int overrun); | |
160 | ||
161 | static enum hrtimer_restart sched_rt_period_timer(struct hrtimer *timer) | |
162 | { | |
163 | struct rt_bandwidth *rt_b = | |
164 | container_of(timer, struct rt_bandwidth, rt_period_timer); | |
165 | ktime_t now; | |
166 | int overrun; | |
167 | int idle = 0; | |
168 | ||
169 | for (;;) { | |
170 | now = hrtimer_cb_get_time(timer); | |
171 | overrun = hrtimer_forward(timer, now, rt_b->rt_period); | |
172 | ||
173 | if (!overrun) | |
174 | break; | |
175 | ||
176 | idle = do_sched_rt_period_timer(rt_b, overrun); | |
177 | } | |
178 | ||
179 | return idle ? HRTIMER_NORESTART : HRTIMER_RESTART; | |
180 | } | |
181 | ||
182 | static | |
183 | void init_rt_bandwidth(struct rt_bandwidth *rt_b, u64 period, u64 runtime) | |
184 | { | |
185 | rt_b->rt_period = ns_to_ktime(period); | |
186 | rt_b->rt_runtime = runtime; | |
187 | ||
0986b11b | 188 | raw_spin_lock_init(&rt_b->rt_runtime_lock); |
ac086bc2 | 189 | |
d0b27fa7 PZ |
190 | hrtimer_init(&rt_b->rt_period_timer, |
191 | CLOCK_MONOTONIC, HRTIMER_MODE_REL); | |
192 | rt_b->rt_period_timer.function = sched_rt_period_timer; | |
d0b27fa7 PZ |
193 | } |
194 | ||
c8bfff6d KH |
195 | static inline int rt_bandwidth_enabled(void) |
196 | { | |
197 | return sysctl_sched_rt_runtime >= 0; | |
d0b27fa7 PZ |
198 | } |
199 | ||
58088ad0 | 200 | static void start_bandwidth_timer(struct hrtimer *period_timer, ktime_t period) |
d0b27fa7 | 201 | { |
58088ad0 PT |
202 | unsigned long delta; |
203 | ktime_t soft, hard, now; | |
d0b27fa7 | 204 | |
58088ad0 PT |
205 | for (;;) { |
206 | if (hrtimer_active(period_timer)) | |
207 | break; | |
208 | ||
209 | now = hrtimer_cb_get_time(period_timer); | |
210 | hrtimer_forward(period_timer, now, period); | |
d0b27fa7 | 211 | |
58088ad0 PT |
212 | soft = hrtimer_get_softexpires(period_timer); |
213 | hard = hrtimer_get_expires(period_timer); | |
214 | delta = ktime_to_ns(ktime_sub(hard, soft)); | |
215 | __hrtimer_start_range_ns(period_timer, soft, delta, | |
216 | HRTIMER_MODE_ABS_PINNED, 0); | |
217 | } | |
218 | } | |
219 | ||
220 | static void start_rt_bandwidth(struct rt_bandwidth *rt_b) | |
221 | { | |
cac64d00 | 222 | if (!rt_bandwidth_enabled() || rt_b->rt_runtime == RUNTIME_INF) |
d0b27fa7 PZ |
223 | return; |
224 | ||
225 | if (hrtimer_active(&rt_b->rt_period_timer)) | |
226 | return; | |
227 | ||
0986b11b | 228 | raw_spin_lock(&rt_b->rt_runtime_lock); |
58088ad0 | 229 | start_bandwidth_timer(&rt_b->rt_period_timer, rt_b->rt_period); |
0986b11b | 230 | raw_spin_unlock(&rt_b->rt_runtime_lock); |
d0b27fa7 PZ |
231 | } |
232 | ||
233 | #ifdef CONFIG_RT_GROUP_SCHED | |
234 | static void destroy_rt_bandwidth(struct rt_bandwidth *rt_b) | |
235 | { | |
236 | hrtimer_cancel(&rt_b->rt_period_timer); | |
237 | } | |
238 | #endif | |
239 | ||
712555ee | 240 | /* |
c4a8849a | 241 | * sched_domains_mutex serializes calls to init_sched_domains, |
712555ee HC |
242 | * detach_destroy_domains and partition_sched_domains. |
243 | */ | |
244 | static DEFINE_MUTEX(sched_domains_mutex); | |
245 | ||
7c941438 | 246 | #ifdef CONFIG_CGROUP_SCHED |
29f59db3 | 247 | |
68318b8e SV |
248 | #include <linux/cgroup.h> |
249 | ||
29f59db3 SV |
250 | struct cfs_rq; |
251 | ||
6f505b16 PZ |
252 | static LIST_HEAD(task_groups); |
253 | ||
ab84d31e PT |
254 | struct cfs_bandwidth { |
255 | #ifdef CONFIG_CFS_BANDWIDTH | |
256 | raw_spinlock_t lock; | |
257 | ktime_t period; | |
ec12cb7f | 258 | u64 quota, runtime; |
a790de99 | 259 | s64 hierarchal_quota; |
a9cf55b2 | 260 | u64 runtime_expires; |
58088ad0 PT |
261 | |
262 | int idle, timer_active; | |
d8b4986d | 263 | struct hrtimer period_timer, slack_timer; |
85dac906 PT |
264 | struct list_head throttled_cfs_rq; |
265 | ||
e8da1b18 NR |
266 | /* statistics */ |
267 | int nr_periods, nr_throttled; | |
268 | u64 throttled_time; | |
ab84d31e PT |
269 | #endif |
270 | }; | |
271 | ||
29f59db3 | 272 | /* task group related information */ |
4cf86d77 | 273 | struct task_group { |
68318b8e | 274 | struct cgroup_subsys_state css; |
6c415b92 | 275 | |
052f1dc7 | 276 | #ifdef CONFIG_FAIR_GROUP_SCHED |
29f59db3 SV |
277 | /* schedulable entities of this group on each cpu */ |
278 | struct sched_entity **se; | |
279 | /* runqueue "owned" by this group on each cpu */ | |
280 | struct cfs_rq **cfs_rq; | |
281 | unsigned long shares; | |
2069dd75 PZ |
282 | |
283 | atomic_t load_weight; | |
052f1dc7 PZ |
284 | #endif |
285 | ||
286 | #ifdef CONFIG_RT_GROUP_SCHED | |
287 | struct sched_rt_entity **rt_se; | |
288 | struct rt_rq **rt_rq; | |
289 | ||
d0b27fa7 | 290 | struct rt_bandwidth rt_bandwidth; |
052f1dc7 | 291 | #endif |
6b2d7700 | 292 | |
ae8393e5 | 293 | struct rcu_head rcu; |
6f505b16 | 294 | struct list_head list; |
f473aa5e PZ |
295 | |
296 | struct task_group *parent; | |
297 | struct list_head siblings; | |
298 | struct list_head children; | |
5091faa4 MG |
299 | |
300 | #ifdef CONFIG_SCHED_AUTOGROUP | |
301 | struct autogroup *autogroup; | |
302 | #endif | |
ab84d31e PT |
303 | |
304 | struct cfs_bandwidth cfs_bandwidth; | |
29f59db3 SV |
305 | }; |
306 | ||
3d4b47b4 | 307 | /* task_group_lock serializes the addition/removal of task groups */ |
8ed36996 | 308 | static DEFINE_SPINLOCK(task_group_lock); |
ec2c507f | 309 | |
e9036b36 CG |
310 | #ifdef CONFIG_FAIR_GROUP_SCHED |
311 | ||
07e06b01 | 312 | # define ROOT_TASK_GROUP_LOAD NICE_0_LOAD |
052f1dc7 | 313 | |
cb4ad1ff | 314 | /* |
2e084786 LJ |
315 | * A weight of 0 or 1 can cause arithmetics problems. |
316 | * A weight of a cfs_rq is the sum of weights of which entities | |
317 | * are queued on this cfs_rq, so a weight of a entity should not be | |
318 | * too large, so as the shares value of a task group. | |
cb4ad1ff MX |
319 | * (The default weight is 1024 - so there's no practical |
320 | * limitation from this.) | |
321 | */ | |
cd62287e MG |
322 | #define MIN_SHARES (1UL << 1) |
323 | #define MAX_SHARES (1UL << 18) | |
18d95a28 | 324 | |
07e06b01 | 325 | static int root_task_group_load = ROOT_TASK_GROUP_LOAD; |
052f1dc7 PZ |
326 | #endif |
327 | ||
29f59db3 | 328 | /* Default task group. |
3a252015 | 329 | * Every task in system belong to this group at bootup. |
29f59db3 | 330 | */ |
07e06b01 | 331 | struct task_group root_task_group; |
29f59db3 | 332 | |
7c941438 | 333 | #endif /* CONFIG_CGROUP_SCHED */ |
29f59db3 | 334 | |
6aa645ea IM |
335 | /* CFS-related fields in a runqueue */ |
336 | struct cfs_rq { | |
337 | struct load_weight load; | |
953bfcd1 | 338 | unsigned long nr_running, h_nr_running; |
6aa645ea | 339 | |
6aa645ea | 340 | u64 exec_clock; |
e9acbff6 | 341 | u64 min_vruntime; |
3fe1698b PZ |
342 | #ifndef CONFIG_64BIT |
343 | u64 min_vruntime_copy; | |
344 | #endif | |
6aa645ea IM |
345 | |
346 | struct rb_root tasks_timeline; | |
347 | struct rb_node *rb_leftmost; | |
4a55bd5e PZ |
348 | |
349 | struct list_head tasks; | |
350 | struct list_head *balance_iterator; | |
351 | ||
352 | /* | |
353 | * 'curr' points to currently running entity on this cfs_rq. | |
6aa645ea IM |
354 | * It is set to NULL otherwise (i.e when none are currently running). |
355 | */ | |
ac53db59 | 356 | struct sched_entity *curr, *next, *last, *skip; |
ddc97297 | 357 | |
4934a4d3 | 358 | #ifdef CONFIG_SCHED_DEBUG |
5ac5c4d6 | 359 | unsigned int nr_spread_over; |
4934a4d3 | 360 | #endif |
ddc97297 | 361 | |
62160e3f | 362 | #ifdef CONFIG_FAIR_GROUP_SCHED |
6aa645ea IM |
363 | struct rq *rq; /* cpu runqueue to which this cfs_rq is attached */ |
364 | ||
41a2d6cf IM |
365 | /* |
366 | * leaf cfs_rqs are those that hold tasks (lowest schedulable entity in | |
6aa645ea IM |
367 | * a hierarchy). Non-leaf lrqs hold other higher schedulable entities |
368 | * (like users, containers etc.) | |
369 | * | |
370 | * leaf_cfs_rq_list ties together list of leaf cfs_rq's in a cpu. This | |
371 | * list is used during load balance. | |
372 | */ | |
3d4b47b4 | 373 | int on_list; |
41a2d6cf IM |
374 | struct list_head leaf_cfs_rq_list; |
375 | struct task_group *tg; /* group that "owns" this runqueue */ | |
c09595f6 PZ |
376 | |
377 | #ifdef CONFIG_SMP | |
c09595f6 | 378 | /* |
c8cba857 | 379 | * the part of load.weight contributed by tasks |
c09595f6 | 380 | */ |
c8cba857 | 381 | unsigned long task_weight; |
c09595f6 | 382 | |
c8cba857 PZ |
383 | /* |
384 | * h_load = weight * f(tg) | |
385 | * | |
386 | * Where f(tg) is the recursive weight fraction assigned to | |
387 | * this group. | |
388 | */ | |
389 | unsigned long h_load; | |
c09595f6 | 390 | |
c8cba857 | 391 | /* |
3b3d190e PT |
392 | * Maintaining per-cpu shares distribution for group scheduling |
393 | * | |
394 | * load_stamp is the last time we updated the load average | |
395 | * load_last is the last time we updated the load average and saw load | |
396 | * load_unacc_exec_time is currently unaccounted execution time | |
c8cba857 | 397 | */ |
2069dd75 PZ |
398 | u64 load_avg; |
399 | u64 load_period; | |
3b3d190e | 400 | u64 load_stamp, load_last, load_unacc_exec_time; |
f1d239f7 | 401 | |
2069dd75 | 402 | unsigned long load_contribution; |
c09595f6 | 403 | #endif |
ab84d31e PT |
404 | #ifdef CONFIG_CFS_BANDWIDTH |
405 | int runtime_enabled; | |
a9cf55b2 | 406 | u64 runtime_expires; |
ab84d31e | 407 | s64 runtime_remaining; |
85dac906 | 408 | |
e8da1b18 | 409 | u64 throttled_timestamp; |
64660c86 | 410 | int throttled, throttle_count; |
85dac906 | 411 | struct list_head throttled_list; |
ab84d31e | 412 | #endif |
6aa645ea IM |
413 | #endif |
414 | }; | |
1da177e4 | 415 | |
ab84d31e PT |
416 | #ifdef CONFIG_FAIR_GROUP_SCHED |
417 | #ifdef CONFIG_CFS_BANDWIDTH | |
418 | static inline struct cfs_bandwidth *tg_cfs_bandwidth(struct task_group *tg) | |
419 | { | |
420 | return &tg->cfs_bandwidth; | |
421 | } | |
422 | ||
423 | static inline u64 default_cfs_period(void); | |
58088ad0 | 424 | static int do_sched_cfs_period_timer(struct cfs_bandwidth *cfs_b, int overrun); |
d8b4986d PT |
425 | static void do_sched_cfs_slack_timer(struct cfs_bandwidth *cfs_b); |
426 | ||
427 | static enum hrtimer_restart sched_cfs_slack_timer(struct hrtimer *timer) | |
428 | { | |
429 | struct cfs_bandwidth *cfs_b = | |
430 | container_of(timer, struct cfs_bandwidth, slack_timer); | |
431 | do_sched_cfs_slack_timer(cfs_b); | |
432 | ||
433 | return HRTIMER_NORESTART; | |
434 | } | |
58088ad0 PT |
435 | |
436 | static enum hrtimer_restart sched_cfs_period_timer(struct hrtimer *timer) | |
437 | { | |
438 | struct cfs_bandwidth *cfs_b = | |
439 | container_of(timer, struct cfs_bandwidth, period_timer); | |
440 | ktime_t now; | |
441 | int overrun; | |
442 | int idle = 0; | |
443 | ||
444 | for (;;) { | |
445 | now = hrtimer_cb_get_time(timer); | |
446 | overrun = hrtimer_forward(timer, now, cfs_b->period); | |
447 | ||
448 | if (!overrun) | |
449 | break; | |
450 | ||
451 | idle = do_sched_cfs_period_timer(cfs_b, overrun); | |
452 | } | |
453 | ||
454 | return idle ? HRTIMER_NORESTART : HRTIMER_RESTART; | |
455 | } | |
ab84d31e PT |
456 | |
457 | static void init_cfs_bandwidth(struct cfs_bandwidth *cfs_b) | |
458 | { | |
459 | raw_spin_lock_init(&cfs_b->lock); | |
ec12cb7f | 460 | cfs_b->runtime = 0; |
ab84d31e PT |
461 | cfs_b->quota = RUNTIME_INF; |
462 | cfs_b->period = ns_to_ktime(default_cfs_period()); | |
58088ad0 | 463 | |
85dac906 | 464 | INIT_LIST_HEAD(&cfs_b->throttled_cfs_rq); |
58088ad0 PT |
465 | hrtimer_init(&cfs_b->period_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); |
466 | cfs_b->period_timer.function = sched_cfs_period_timer; | |
d8b4986d PT |
467 | hrtimer_init(&cfs_b->slack_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); |
468 | cfs_b->slack_timer.function = sched_cfs_slack_timer; | |
ab84d31e PT |
469 | } |
470 | ||
471 | static void init_cfs_rq_runtime(struct cfs_rq *cfs_rq) | |
472 | { | |
473 | cfs_rq->runtime_enabled = 0; | |
85dac906 | 474 | INIT_LIST_HEAD(&cfs_rq->throttled_list); |
ab84d31e PT |
475 | } |
476 | ||
58088ad0 PT |
477 | /* requires cfs_b->lock, may release to reprogram timer */ |
478 | static void __start_cfs_bandwidth(struct cfs_bandwidth *cfs_b) | |
479 | { | |
480 | /* | |
481 | * The timer may be active because we're trying to set a new bandwidth | |
482 | * period or because we're racing with the tear-down path | |
483 | * (timer_active==0 becomes visible before the hrtimer call-back | |
484 | * terminates). In either case we ensure that it's re-programmed | |
485 | */ | |
486 | while (unlikely(hrtimer_active(&cfs_b->period_timer))) { | |
487 | raw_spin_unlock(&cfs_b->lock); | |
488 | /* ensure cfs_b->lock is available while we wait */ | |
489 | hrtimer_cancel(&cfs_b->period_timer); | |
490 | ||
491 | raw_spin_lock(&cfs_b->lock); | |
492 | /* if someone else restarted the timer then we're done */ | |
493 | if (cfs_b->timer_active) | |
494 | return; | |
495 | } | |
496 | ||
497 | cfs_b->timer_active = 1; | |
498 | start_bandwidth_timer(&cfs_b->period_timer, cfs_b->period); | |
499 | } | |
500 | ||
ab84d31e | 501 | static void destroy_cfs_bandwidth(struct cfs_bandwidth *cfs_b) |
58088ad0 PT |
502 | { |
503 | hrtimer_cancel(&cfs_b->period_timer); | |
d8b4986d | 504 | hrtimer_cancel(&cfs_b->slack_timer); |
58088ad0 | 505 | } |
ab84d31e PT |
506 | #else |
507 | static void init_cfs_rq_runtime(struct cfs_rq *cfs_rq) {} | |
508 | static void init_cfs_bandwidth(struct cfs_bandwidth *cfs_b) {} | |
509 | static void destroy_cfs_bandwidth(struct cfs_bandwidth *cfs_b) {} | |
510 | ||
511 | static inline struct cfs_bandwidth *tg_cfs_bandwidth(struct task_group *tg) | |
512 | { | |
513 | return NULL; | |
514 | } | |
515 | #endif /* CONFIG_CFS_BANDWIDTH */ | |
516 | #endif /* CONFIG_FAIR_GROUP_SCHED */ | |
517 | ||
6aa645ea IM |
518 | /* Real-Time classes' related field in a runqueue: */ |
519 | struct rt_rq { | |
520 | struct rt_prio_array active; | |
63489e45 | 521 | unsigned long rt_nr_running; |
052f1dc7 | 522 | #if defined CONFIG_SMP || defined CONFIG_RT_GROUP_SCHED |
e864c499 GH |
523 | struct { |
524 | int curr; /* highest queued rt task prio */ | |
398a153b | 525 | #ifdef CONFIG_SMP |
e864c499 | 526 | int next; /* next highest */ |
398a153b | 527 | #endif |
e864c499 | 528 | } highest_prio; |
6f505b16 | 529 | #endif |
fa85ae24 | 530 | #ifdef CONFIG_SMP |
73fe6aae | 531 | unsigned long rt_nr_migratory; |
a1ba4d8b | 532 | unsigned long rt_nr_total; |
a22d7fc1 | 533 | int overloaded; |
917b627d | 534 | struct plist_head pushable_tasks; |
fa85ae24 | 535 | #endif |
6f505b16 | 536 | int rt_throttled; |
fa85ae24 | 537 | u64 rt_time; |
ac086bc2 | 538 | u64 rt_runtime; |
ea736ed5 | 539 | /* Nests inside the rq lock: */ |
0986b11b | 540 | raw_spinlock_t rt_runtime_lock; |
6f505b16 | 541 | |
052f1dc7 | 542 | #ifdef CONFIG_RT_GROUP_SCHED |
23b0fdfc PZ |
543 | unsigned long rt_nr_boosted; |
544 | ||
6f505b16 PZ |
545 | struct rq *rq; |
546 | struct list_head leaf_rt_rq_list; | |
547 | struct task_group *tg; | |
6f505b16 | 548 | #endif |
6aa645ea IM |
549 | }; |
550 | ||
57d885fe GH |
551 | #ifdef CONFIG_SMP |
552 | ||
553 | /* | |
554 | * We add the notion of a root-domain which will be used to define per-domain | |
0eab9146 IM |
555 | * variables. Each exclusive cpuset essentially defines an island domain by |
556 | * fully partitioning the member cpus from any other cpuset. Whenever a new | |
57d885fe GH |
557 | * exclusive cpuset is created, we also create and attach a new root-domain |
558 | * object. | |
559 | * | |
57d885fe GH |
560 | */ |
561 | struct root_domain { | |
562 | atomic_t refcount; | |
26a148eb | 563 | atomic_t rto_count; |
dce840a0 | 564 | struct rcu_head rcu; |
c6c4927b RR |
565 | cpumask_var_t span; |
566 | cpumask_var_t online; | |
637f5085 | 567 | |
0eab9146 | 568 | /* |
637f5085 GH |
569 | * The "RT overload" flag: it gets set if a CPU has more than |
570 | * one runnable RT task. | |
571 | */ | |
c6c4927b | 572 | cpumask_var_t rto_mask; |
6e0534f2 | 573 | struct cpupri cpupri; |
57d885fe GH |
574 | }; |
575 | ||
dc938520 GH |
576 | /* |
577 | * By default the system creates a single root-domain with all cpus as | |
578 | * members (mimicking the global state we have today). | |
579 | */ | |
57d885fe GH |
580 | static struct root_domain def_root_domain; |
581 | ||
ed2d372c | 582 | #endif /* CONFIG_SMP */ |
57d885fe | 583 | |
1da177e4 LT |
584 | /* |
585 | * This is the main, per-CPU runqueue data structure. | |
586 | * | |
587 | * Locking rule: those places that want to lock multiple runqueues | |
588 | * (such as the load balancing or the thread migration code), lock | |
589 | * acquire operations must be ordered by ascending &runqueue. | |
590 | */ | |
70b97a7f | 591 | struct rq { |
d8016491 | 592 | /* runqueue lock: */ |
05fa785c | 593 | raw_spinlock_t lock; |
1da177e4 LT |
594 | |
595 | /* | |
596 | * nr_running and cpu_load should be in the same cacheline because | |
597 | * remote CPUs use both these fields when doing load calculation. | |
598 | */ | |
599 | unsigned long nr_running; | |
6aa645ea IM |
600 | #define CPU_LOAD_IDX_MAX 5 |
601 | unsigned long cpu_load[CPU_LOAD_IDX_MAX]; | |
fdf3e95d | 602 | unsigned long last_load_update_tick; |
46cb4b7c | 603 | #ifdef CONFIG_NO_HZ |
39c0cbe2 | 604 | u64 nohz_stamp; |
83cd4fe2 | 605 | unsigned char nohz_balance_kick; |
46cb4b7c | 606 | #endif |
61eadef6 | 607 | int skip_clock_update; |
a64692a3 | 608 | |
d8016491 IM |
609 | /* capture load from *all* tasks on this cpu: */ |
610 | struct load_weight load; | |
6aa645ea IM |
611 | unsigned long nr_load_updates; |
612 | u64 nr_switches; | |
613 | ||
614 | struct cfs_rq cfs; | |
6f505b16 | 615 | struct rt_rq rt; |
6f505b16 | 616 | |
6aa645ea | 617 | #ifdef CONFIG_FAIR_GROUP_SCHED |
d8016491 IM |
618 | /* list of leaf cfs_rq on this cpu: */ |
619 | struct list_head leaf_cfs_rq_list; | |
052f1dc7 PZ |
620 | #endif |
621 | #ifdef CONFIG_RT_GROUP_SCHED | |
6f505b16 | 622 | struct list_head leaf_rt_rq_list; |
1da177e4 | 623 | #endif |
1da177e4 LT |
624 | |
625 | /* | |
626 | * This is part of a global counter where only the total sum | |
627 | * over all CPUs matters. A task can increase this counter on | |
628 | * one CPU and if it got migrated afterwards it may decrease | |
629 | * it on another CPU. Always updated under the runqueue lock: | |
630 | */ | |
631 | unsigned long nr_uninterruptible; | |
632 | ||
34f971f6 | 633 | struct task_struct *curr, *idle, *stop; |
c9819f45 | 634 | unsigned long next_balance; |
1da177e4 | 635 | struct mm_struct *prev_mm; |
6aa645ea | 636 | |
3e51f33f | 637 | u64 clock; |
305e6835 | 638 | u64 clock_task; |
6aa645ea | 639 | |
1da177e4 LT |
640 | atomic_t nr_iowait; |
641 | ||
642 | #ifdef CONFIG_SMP | |
0eab9146 | 643 | struct root_domain *rd; |
1da177e4 LT |
644 | struct sched_domain *sd; |
645 | ||
e51fd5e2 PZ |
646 | unsigned long cpu_power; |
647 | ||
6eb57e0d | 648 | unsigned char idle_balance; |
1da177e4 | 649 | /* For active balancing */ |
3f029d3c | 650 | int post_schedule; |
1da177e4 LT |
651 | int active_balance; |
652 | int push_cpu; | |
969c7921 | 653 | struct cpu_stop_work active_balance_work; |
d8016491 IM |
654 | /* cpu of this runqueue: */ |
655 | int cpu; | |
1f11eb6a | 656 | int online; |
1da177e4 | 657 | |
e9e9250b PZ |
658 | u64 rt_avg; |
659 | u64 age_stamp; | |
1b9508f6 MG |
660 | u64 idle_stamp; |
661 | u64 avg_idle; | |
1da177e4 LT |
662 | #endif |
663 | ||
aa483808 VP |
664 | #ifdef CONFIG_IRQ_TIME_ACCOUNTING |
665 | u64 prev_irq_time; | |
666 | #endif | |
e6e6685a GC |
667 | #ifdef CONFIG_PARAVIRT |
668 | u64 prev_steal_time; | |
669 | #endif | |
095c0aa8 GC |
670 | #ifdef CONFIG_PARAVIRT_TIME_ACCOUNTING |
671 | u64 prev_steal_time_rq; | |
672 | #endif | |
aa483808 | 673 | |
dce48a84 TG |
674 | /* calc_load related fields */ |
675 | unsigned long calc_load_update; | |
676 | long calc_load_active; | |
677 | ||
8f4d37ec | 678 | #ifdef CONFIG_SCHED_HRTICK |
31656519 PZ |
679 | #ifdef CONFIG_SMP |
680 | int hrtick_csd_pending; | |
681 | struct call_single_data hrtick_csd; | |
682 | #endif | |
8f4d37ec PZ |
683 | struct hrtimer hrtick_timer; |
684 | #endif | |
685 | ||
1da177e4 LT |
686 | #ifdef CONFIG_SCHEDSTATS |
687 | /* latency stats */ | |
688 | struct sched_info rq_sched_info; | |
9c2c4802 KC |
689 | unsigned long long rq_cpu_time; |
690 | /* could above be rq->cfs_rq.exec_clock + rq->rt_rq.rt_runtime ? */ | |
1da177e4 LT |
691 | |
692 | /* sys_sched_yield() stats */ | |
480b9434 | 693 | unsigned int yld_count; |
1da177e4 LT |
694 | |
695 | /* schedule() stats */ | |
480b9434 KC |
696 | unsigned int sched_switch; |
697 | unsigned int sched_count; | |
698 | unsigned int sched_goidle; | |
1da177e4 LT |
699 | |
700 | /* try_to_wake_up() stats */ | |
480b9434 KC |
701 | unsigned int ttwu_count; |
702 | unsigned int ttwu_local; | |
1da177e4 | 703 | #endif |
317f3941 PZ |
704 | |
705 | #ifdef CONFIG_SMP | |
fa14ff4a | 706 | struct llist_head wake_list; |
317f3941 | 707 | #endif |
1da177e4 LT |
708 | }; |
709 | ||
f34e3b61 | 710 | static DEFINE_PER_CPU_SHARED_ALIGNED(struct rq, runqueues); |
1da177e4 | 711 | |
a64692a3 | 712 | |
1e5a7405 | 713 | static void check_preempt_curr(struct rq *rq, struct task_struct *p, int flags); |
dd41f596 | 714 | |
0a2966b4 CL |
715 | static inline int cpu_of(struct rq *rq) |
716 | { | |
717 | #ifdef CONFIG_SMP | |
718 | return rq->cpu; | |
719 | #else | |
720 | return 0; | |
721 | #endif | |
722 | } | |
723 | ||
497f0ab3 | 724 | #define rcu_dereference_check_sched_domain(p) \ |
d11c563d | 725 | rcu_dereference_check((p), \ |
d11c563d PM |
726 | lockdep_is_held(&sched_domains_mutex)) |
727 | ||
674311d5 NP |
728 | /* |
729 | * The domain tree (rq->sd) is protected by RCU's quiescent state transition. | |
1a20ff27 | 730 | * See detach_destroy_domains: synchronize_sched for details. |
674311d5 NP |
731 | * |
732 | * The domain tree of any CPU may only be accessed from within | |
733 | * preempt-disabled sections. | |
734 | */ | |
48f24c4d | 735 | #define for_each_domain(cpu, __sd) \ |
497f0ab3 | 736 | for (__sd = rcu_dereference_check_sched_domain(cpu_rq(cpu)->sd); __sd; __sd = __sd->parent) |
1da177e4 LT |
737 | |
738 | #define cpu_rq(cpu) (&per_cpu(runqueues, (cpu))) | |
739 | #define this_rq() (&__get_cpu_var(runqueues)) | |
740 | #define task_rq(p) cpu_rq(task_cpu(p)) | |
741 | #define cpu_curr(cpu) (cpu_rq(cpu)->curr) | |
54d35f29 | 742 | #define raw_rq() (&__raw_get_cpu_var(runqueues)) |
1da177e4 | 743 | |
dc61b1d6 PZ |
744 | #ifdef CONFIG_CGROUP_SCHED |
745 | ||
746 | /* | |
747 | * Return the group to which this tasks belongs. | |
748 | * | |
6c6c54e1 PZ |
749 | * We use task_subsys_state_check() and extend the RCU verification with |
750 | * pi->lock and rq->lock because cpu_cgroup_attach() holds those locks for each | |
751 | * task it moves into the cgroup. Therefore by holding either of those locks, | |
752 | * we pin the task to the current cgroup. | |
dc61b1d6 PZ |
753 | */ |
754 | static inline struct task_group *task_group(struct task_struct *p) | |
755 | { | |
5091faa4 | 756 | struct task_group *tg; |
dc61b1d6 PZ |
757 | struct cgroup_subsys_state *css; |
758 | ||
759 | css = task_subsys_state_check(p, cpu_cgroup_subsys_id, | |
6c6c54e1 PZ |
760 | lockdep_is_held(&p->pi_lock) || |
761 | lockdep_is_held(&task_rq(p)->lock)); | |
5091faa4 MG |
762 | tg = container_of(css, struct task_group, css); |
763 | ||
764 | return autogroup_task_group(p, tg); | |
dc61b1d6 PZ |
765 | } |
766 | ||
767 | /* Change a task's cfs_rq and parent entity if it moves across CPUs/groups */ | |
768 | static inline void set_task_rq(struct task_struct *p, unsigned int cpu) | |
769 | { | |
770 | #ifdef CONFIG_FAIR_GROUP_SCHED | |
771 | p->se.cfs_rq = task_group(p)->cfs_rq[cpu]; | |
772 | p->se.parent = task_group(p)->se[cpu]; | |
773 | #endif | |
774 | ||
775 | #ifdef CONFIG_RT_GROUP_SCHED | |
776 | p->rt.rt_rq = task_group(p)->rt_rq[cpu]; | |
777 | p->rt.parent = task_group(p)->rt_se[cpu]; | |
778 | #endif | |
779 | } | |
780 | ||
781 | #else /* CONFIG_CGROUP_SCHED */ | |
782 | ||
783 | static inline void set_task_rq(struct task_struct *p, unsigned int cpu) { } | |
784 | static inline struct task_group *task_group(struct task_struct *p) | |
785 | { | |
786 | return NULL; | |
787 | } | |
788 | ||
789 | #endif /* CONFIG_CGROUP_SCHED */ | |
790 | ||
fe44d621 | 791 | static void update_rq_clock_task(struct rq *rq, s64 delta); |
305e6835 | 792 | |
fe44d621 | 793 | static void update_rq_clock(struct rq *rq) |
3e51f33f | 794 | { |
fe44d621 | 795 | s64 delta; |
305e6835 | 796 | |
61eadef6 | 797 | if (rq->skip_clock_update > 0) |
f26f9aff | 798 | return; |
aa483808 | 799 | |
fe44d621 PZ |
800 | delta = sched_clock_cpu(cpu_of(rq)) - rq->clock; |
801 | rq->clock += delta; | |
802 | update_rq_clock_task(rq, delta); | |
3e51f33f PZ |
803 | } |
804 | ||
bf5c91ba IM |
805 | /* |
806 | * Tunables that become constants when CONFIG_SCHED_DEBUG is off: | |
807 | */ | |
808 | #ifdef CONFIG_SCHED_DEBUG | |
809 | # define const_debug __read_mostly | |
810 | #else | |
811 | # define const_debug static const | |
812 | #endif | |
813 | ||
017730c1 | 814 | /** |
1fd06bb1 | 815 | * runqueue_is_locked - Returns true if the current cpu runqueue is locked |
e17b38bf | 816 | * @cpu: the processor in question. |
017730c1 | 817 | * |
017730c1 IM |
818 | * This interface allows printk to be called with the runqueue lock |
819 | * held and know whether or not it is OK to wake up the klogd. | |
820 | */ | |
89f19f04 | 821 | int runqueue_is_locked(int cpu) |
017730c1 | 822 | { |
05fa785c | 823 | return raw_spin_is_locked(&cpu_rq(cpu)->lock); |
017730c1 IM |
824 | } |
825 | ||
bf5c91ba IM |
826 | /* |
827 | * Debugging: various feature bits | |
828 | */ | |
f00b45c1 PZ |
829 | |
830 | #define SCHED_FEAT(name, enabled) \ | |
831 | __SCHED_FEAT_##name , | |
832 | ||
bf5c91ba | 833 | enum { |
f00b45c1 | 834 | #include "sched_features.h" |
bf5c91ba IM |
835 | }; |
836 | ||
f00b45c1 PZ |
837 | #undef SCHED_FEAT |
838 | ||
839 | #define SCHED_FEAT(name, enabled) \ | |
840 | (1UL << __SCHED_FEAT_##name) * enabled | | |
841 | ||
bf5c91ba | 842 | const_debug unsigned int sysctl_sched_features = |
f00b45c1 PZ |
843 | #include "sched_features.h" |
844 | 0; | |
845 | ||
846 | #undef SCHED_FEAT | |
847 | ||
848 | #ifdef CONFIG_SCHED_DEBUG | |
849 | #define SCHED_FEAT(name, enabled) \ | |
850 | #name , | |
851 | ||
983ed7a6 | 852 | static __read_mostly char *sched_feat_names[] = { |
f00b45c1 PZ |
853 | #include "sched_features.h" |
854 | NULL | |
855 | }; | |
856 | ||
857 | #undef SCHED_FEAT | |
858 | ||
34f3a814 | 859 | static int sched_feat_show(struct seq_file *m, void *v) |
f00b45c1 | 860 | { |
f00b45c1 PZ |
861 | int i; |
862 | ||
863 | for (i = 0; sched_feat_names[i]; i++) { | |
34f3a814 LZ |
864 | if (!(sysctl_sched_features & (1UL << i))) |
865 | seq_puts(m, "NO_"); | |
866 | seq_printf(m, "%s ", sched_feat_names[i]); | |
f00b45c1 | 867 | } |
34f3a814 | 868 | seq_puts(m, "\n"); |
f00b45c1 | 869 | |
34f3a814 | 870 | return 0; |
f00b45c1 PZ |
871 | } |
872 | ||
873 | static ssize_t | |
874 | sched_feat_write(struct file *filp, const char __user *ubuf, | |
875 | size_t cnt, loff_t *ppos) | |
876 | { | |
877 | char buf[64]; | |
7740191c | 878 | char *cmp; |
f00b45c1 PZ |
879 | int neg = 0; |
880 | int i; | |
881 | ||
882 | if (cnt > 63) | |
883 | cnt = 63; | |
884 | ||
885 | if (copy_from_user(&buf, ubuf, cnt)) | |
886 | return -EFAULT; | |
887 | ||
888 | buf[cnt] = 0; | |
7740191c | 889 | cmp = strstrip(buf); |
f00b45c1 | 890 | |
524429c3 | 891 | if (strncmp(cmp, "NO_", 3) == 0) { |
f00b45c1 PZ |
892 | neg = 1; |
893 | cmp += 3; | |
894 | } | |
895 | ||
896 | for (i = 0; sched_feat_names[i]; i++) { | |
7740191c | 897 | if (strcmp(cmp, sched_feat_names[i]) == 0) { |
f00b45c1 PZ |
898 | if (neg) |
899 | sysctl_sched_features &= ~(1UL << i); | |
900 | else | |
901 | sysctl_sched_features |= (1UL << i); | |
902 | break; | |
903 | } | |
904 | } | |
905 | ||
906 | if (!sched_feat_names[i]) | |
907 | return -EINVAL; | |
908 | ||
42994724 | 909 | *ppos += cnt; |
f00b45c1 PZ |
910 | |
911 | return cnt; | |
912 | } | |
913 | ||
34f3a814 LZ |
914 | static int sched_feat_open(struct inode *inode, struct file *filp) |
915 | { | |
916 | return single_open(filp, sched_feat_show, NULL); | |
917 | } | |
918 | ||
828c0950 | 919 | static const struct file_operations sched_feat_fops = { |
34f3a814 LZ |
920 | .open = sched_feat_open, |
921 | .write = sched_feat_write, | |
922 | .read = seq_read, | |
923 | .llseek = seq_lseek, | |
924 | .release = single_release, | |
f00b45c1 PZ |
925 | }; |
926 | ||
927 | static __init int sched_init_debug(void) | |
928 | { | |
f00b45c1 PZ |
929 | debugfs_create_file("sched_features", 0644, NULL, NULL, |
930 | &sched_feat_fops); | |
931 | ||
932 | return 0; | |
933 | } | |
934 | late_initcall(sched_init_debug); | |
935 | ||
936 | #endif | |
937 | ||
938 | #define sched_feat(x) (sysctl_sched_features & (1UL << __SCHED_FEAT_##x)) | |
bf5c91ba | 939 | |
b82d9fdd PZ |
940 | /* |
941 | * Number of tasks to iterate in a single balance run. | |
942 | * Limited because this is done with IRQs disabled. | |
943 | */ | |
944 | const_debug unsigned int sysctl_sched_nr_migrate = 32; | |
945 | ||
e9e9250b PZ |
946 | /* |
947 | * period over which we average the RT time consumption, measured | |
948 | * in ms. | |
949 | * | |
950 | * default: 1s | |
951 | */ | |
952 | const_debug unsigned int sysctl_sched_time_avg = MSEC_PER_SEC; | |
953 | ||
fa85ae24 | 954 | /* |
9f0c1e56 | 955 | * period over which we measure -rt task cpu usage in us. |
fa85ae24 PZ |
956 | * default: 1s |
957 | */ | |
9f0c1e56 | 958 | unsigned int sysctl_sched_rt_period = 1000000; |
fa85ae24 | 959 | |
6892b75e IM |
960 | static __read_mostly int scheduler_running; |
961 | ||
9f0c1e56 PZ |
962 | /* |
963 | * part of the period that we allow rt tasks to run in us. | |
964 | * default: 0.95s | |
965 | */ | |
966 | int sysctl_sched_rt_runtime = 950000; | |
fa85ae24 | 967 | |
d0b27fa7 PZ |
968 | static inline u64 global_rt_period(void) |
969 | { | |
970 | return (u64)sysctl_sched_rt_period * NSEC_PER_USEC; | |
971 | } | |
972 | ||
973 | static inline u64 global_rt_runtime(void) | |
974 | { | |
e26873bb | 975 | if (sysctl_sched_rt_runtime < 0) |
d0b27fa7 PZ |
976 | return RUNTIME_INF; |
977 | ||
978 | return (u64)sysctl_sched_rt_runtime * NSEC_PER_USEC; | |
979 | } | |
fa85ae24 | 980 | |
1da177e4 | 981 | #ifndef prepare_arch_switch |
4866cde0 NP |
982 | # define prepare_arch_switch(next) do { } while (0) |
983 | #endif | |
984 | #ifndef finish_arch_switch | |
985 | # define finish_arch_switch(prev) do { } while (0) | |
986 | #endif | |
987 | ||
051a1d1a DA |
988 | static inline int task_current(struct rq *rq, struct task_struct *p) |
989 | { | |
990 | return rq->curr == p; | |
991 | } | |
992 | ||
70b97a7f | 993 | static inline int task_running(struct rq *rq, struct task_struct *p) |
4866cde0 | 994 | { |
3ca7a440 PZ |
995 | #ifdef CONFIG_SMP |
996 | return p->on_cpu; | |
997 | #else | |
051a1d1a | 998 | return task_current(rq, p); |
3ca7a440 | 999 | #endif |
4866cde0 NP |
1000 | } |
1001 | ||
3ca7a440 | 1002 | #ifndef __ARCH_WANT_UNLOCKED_CTXSW |
70b97a7f | 1003 | static inline void prepare_lock_switch(struct rq *rq, struct task_struct *next) |
4866cde0 | 1004 | { |
3ca7a440 PZ |
1005 | #ifdef CONFIG_SMP |
1006 | /* | |
1007 | * We can optimise this out completely for !SMP, because the | |
1008 | * SMP rebalancing from interrupt is the only thing that cares | |
1009 | * here. | |
1010 | */ | |
1011 | next->on_cpu = 1; | |
1012 | #endif | |
4866cde0 NP |
1013 | } |
1014 | ||
70b97a7f | 1015 | static inline void finish_lock_switch(struct rq *rq, struct task_struct *prev) |
4866cde0 | 1016 | { |
3ca7a440 PZ |
1017 | #ifdef CONFIG_SMP |
1018 | /* | |
1019 | * After ->on_cpu is cleared, the task can be moved to a different CPU. | |
1020 | * We must ensure this doesn't happen until the switch is completely | |
1021 | * finished. | |
1022 | */ | |
1023 | smp_wmb(); | |
1024 | prev->on_cpu = 0; | |
1025 | #endif | |
da04c035 IM |
1026 | #ifdef CONFIG_DEBUG_SPINLOCK |
1027 | /* this is a valid case when another task releases the spinlock */ | |
1028 | rq->lock.owner = current; | |
1029 | #endif | |
8a25d5de IM |
1030 | /* |
1031 | * If we are tracking spinlock dependencies then we have to | |
1032 | * fix up the runqueue lock - which gets 'carried over' from | |
1033 | * prev into current: | |
1034 | */ | |
1035 | spin_acquire(&rq->lock.dep_map, 0, 0, _THIS_IP_); | |
1036 | ||
05fa785c | 1037 | raw_spin_unlock_irq(&rq->lock); |
4866cde0 NP |
1038 | } |
1039 | ||
1040 | #else /* __ARCH_WANT_UNLOCKED_CTXSW */ | |
70b97a7f | 1041 | static inline void prepare_lock_switch(struct rq *rq, struct task_struct *next) |
4866cde0 NP |
1042 | { |
1043 | #ifdef CONFIG_SMP | |
1044 | /* | |
1045 | * We can optimise this out completely for !SMP, because the | |
1046 | * SMP rebalancing from interrupt is the only thing that cares | |
1047 | * here. | |
1048 | */ | |
3ca7a440 | 1049 | next->on_cpu = 1; |
4866cde0 NP |
1050 | #endif |
1051 | #ifdef __ARCH_WANT_INTERRUPTS_ON_CTXSW | |
05fa785c | 1052 | raw_spin_unlock_irq(&rq->lock); |
4866cde0 | 1053 | #else |
05fa785c | 1054 | raw_spin_unlock(&rq->lock); |
4866cde0 NP |
1055 | #endif |
1056 | } | |
1057 | ||
70b97a7f | 1058 | static inline void finish_lock_switch(struct rq *rq, struct task_struct *prev) |
4866cde0 NP |
1059 | { |
1060 | #ifdef CONFIG_SMP | |
1061 | /* | |
3ca7a440 | 1062 | * After ->on_cpu is cleared, the task can be moved to a different CPU. |
4866cde0 NP |
1063 | * We must ensure this doesn't happen until the switch is completely |
1064 | * finished. | |
1065 | */ | |
1066 | smp_wmb(); | |
3ca7a440 | 1067 | prev->on_cpu = 0; |
4866cde0 NP |
1068 | #endif |
1069 | #ifndef __ARCH_WANT_INTERRUPTS_ON_CTXSW | |
1070 | local_irq_enable(); | |
1da177e4 | 1071 | #endif |
4866cde0 NP |
1072 | } |
1073 | #endif /* __ARCH_WANT_UNLOCKED_CTXSW */ | |
1da177e4 | 1074 | |
0970d299 | 1075 | /* |
0122ec5b | 1076 | * __task_rq_lock - lock the rq @p resides on. |
b29739f9 | 1077 | */ |
70b97a7f | 1078 | static inline struct rq *__task_rq_lock(struct task_struct *p) |
b29739f9 IM |
1079 | __acquires(rq->lock) |
1080 | { | |
0970d299 PZ |
1081 | struct rq *rq; |
1082 | ||
0122ec5b PZ |
1083 | lockdep_assert_held(&p->pi_lock); |
1084 | ||
3a5c359a | 1085 | for (;;) { |
0970d299 | 1086 | rq = task_rq(p); |
05fa785c | 1087 | raw_spin_lock(&rq->lock); |
65cc8e48 | 1088 | if (likely(rq == task_rq(p))) |
3a5c359a | 1089 | return rq; |
05fa785c | 1090 | raw_spin_unlock(&rq->lock); |
b29739f9 | 1091 | } |
b29739f9 IM |
1092 | } |
1093 | ||
1da177e4 | 1094 | /* |
0122ec5b | 1095 | * task_rq_lock - lock p->pi_lock and lock the rq @p resides on. |
1da177e4 | 1096 | */ |
70b97a7f | 1097 | static struct rq *task_rq_lock(struct task_struct *p, unsigned long *flags) |
0122ec5b | 1098 | __acquires(p->pi_lock) |
1da177e4 LT |
1099 | __acquires(rq->lock) |
1100 | { | |
70b97a7f | 1101 | struct rq *rq; |
1da177e4 | 1102 | |
3a5c359a | 1103 | for (;;) { |
0122ec5b | 1104 | raw_spin_lock_irqsave(&p->pi_lock, *flags); |
3a5c359a | 1105 | rq = task_rq(p); |
05fa785c | 1106 | raw_spin_lock(&rq->lock); |
65cc8e48 | 1107 | if (likely(rq == task_rq(p))) |
3a5c359a | 1108 | return rq; |
0122ec5b PZ |
1109 | raw_spin_unlock(&rq->lock); |
1110 | raw_spin_unlock_irqrestore(&p->pi_lock, *flags); | |
1da177e4 | 1111 | } |
1da177e4 LT |
1112 | } |
1113 | ||
a9957449 | 1114 | static void __task_rq_unlock(struct rq *rq) |
b29739f9 IM |
1115 | __releases(rq->lock) |
1116 | { | |
05fa785c | 1117 | raw_spin_unlock(&rq->lock); |
b29739f9 IM |
1118 | } |
1119 | ||
0122ec5b PZ |
1120 | static inline void |
1121 | task_rq_unlock(struct rq *rq, struct task_struct *p, unsigned long *flags) | |
1da177e4 | 1122 | __releases(rq->lock) |
0122ec5b | 1123 | __releases(p->pi_lock) |
1da177e4 | 1124 | { |
0122ec5b PZ |
1125 | raw_spin_unlock(&rq->lock); |
1126 | raw_spin_unlock_irqrestore(&p->pi_lock, *flags); | |
1da177e4 LT |
1127 | } |
1128 | ||
1da177e4 | 1129 | /* |
cc2a73b5 | 1130 | * this_rq_lock - lock this runqueue and disable interrupts. |
1da177e4 | 1131 | */ |
a9957449 | 1132 | static struct rq *this_rq_lock(void) |
1da177e4 LT |
1133 | __acquires(rq->lock) |
1134 | { | |
70b97a7f | 1135 | struct rq *rq; |
1da177e4 LT |
1136 | |
1137 | local_irq_disable(); | |
1138 | rq = this_rq(); | |
05fa785c | 1139 | raw_spin_lock(&rq->lock); |
1da177e4 LT |
1140 | |
1141 | return rq; | |
1142 | } | |
1143 | ||
8f4d37ec PZ |
1144 | #ifdef CONFIG_SCHED_HRTICK |
1145 | /* | |
1146 | * Use HR-timers to deliver accurate preemption points. | |
1147 | * | |
1148 | * Its all a bit involved since we cannot program an hrt while holding the | |
1149 | * rq->lock. So what we do is store a state in in rq->hrtick_* and ask for a | |
1150 | * reschedule event. | |
1151 | * | |
1152 | * When we get rescheduled we reprogram the hrtick_timer outside of the | |
1153 | * rq->lock. | |
1154 | */ | |
8f4d37ec PZ |
1155 | |
1156 | /* | |
1157 | * Use hrtick when: | |
1158 | * - enabled by features | |
1159 | * - hrtimer is actually high res | |
1160 | */ | |
1161 | static inline int hrtick_enabled(struct rq *rq) | |
1162 | { | |
1163 | if (!sched_feat(HRTICK)) | |
1164 | return 0; | |
ba42059f | 1165 | if (!cpu_active(cpu_of(rq))) |
b328ca18 | 1166 | return 0; |
8f4d37ec PZ |
1167 | return hrtimer_is_hres_active(&rq->hrtick_timer); |
1168 | } | |
1169 | ||
8f4d37ec PZ |
1170 | static void hrtick_clear(struct rq *rq) |
1171 | { | |
1172 | if (hrtimer_active(&rq->hrtick_timer)) | |
1173 | hrtimer_cancel(&rq->hrtick_timer); | |
1174 | } | |
1175 | ||
8f4d37ec PZ |
1176 | /* |
1177 | * High-resolution timer tick. | |
1178 | * Runs from hardirq context with interrupts disabled. | |
1179 | */ | |
1180 | static enum hrtimer_restart hrtick(struct hrtimer *timer) | |
1181 | { | |
1182 | struct rq *rq = container_of(timer, struct rq, hrtick_timer); | |
1183 | ||
1184 | WARN_ON_ONCE(cpu_of(rq) != smp_processor_id()); | |
1185 | ||
05fa785c | 1186 | raw_spin_lock(&rq->lock); |
3e51f33f | 1187 | update_rq_clock(rq); |
8f4d37ec | 1188 | rq->curr->sched_class->task_tick(rq, rq->curr, 1); |
05fa785c | 1189 | raw_spin_unlock(&rq->lock); |
8f4d37ec PZ |
1190 | |
1191 | return HRTIMER_NORESTART; | |
1192 | } | |
1193 | ||
95e904c7 | 1194 | #ifdef CONFIG_SMP |
31656519 PZ |
1195 | /* |
1196 | * called from hardirq (IPI) context | |
1197 | */ | |
1198 | static void __hrtick_start(void *arg) | |
b328ca18 | 1199 | { |
31656519 | 1200 | struct rq *rq = arg; |
b328ca18 | 1201 | |
05fa785c | 1202 | raw_spin_lock(&rq->lock); |
31656519 PZ |
1203 | hrtimer_restart(&rq->hrtick_timer); |
1204 | rq->hrtick_csd_pending = 0; | |
05fa785c | 1205 | raw_spin_unlock(&rq->lock); |
b328ca18 PZ |
1206 | } |
1207 | ||
31656519 PZ |
1208 | /* |
1209 | * Called to set the hrtick timer state. | |
1210 | * | |
1211 | * called with rq->lock held and irqs disabled | |
1212 | */ | |
1213 | static void hrtick_start(struct rq *rq, u64 delay) | |
b328ca18 | 1214 | { |
31656519 PZ |
1215 | struct hrtimer *timer = &rq->hrtick_timer; |
1216 | ktime_t time = ktime_add_ns(timer->base->get_time(), delay); | |
b328ca18 | 1217 | |
cc584b21 | 1218 | hrtimer_set_expires(timer, time); |
31656519 PZ |
1219 | |
1220 | if (rq == this_rq()) { | |
1221 | hrtimer_restart(timer); | |
1222 | } else if (!rq->hrtick_csd_pending) { | |
6e275637 | 1223 | __smp_call_function_single(cpu_of(rq), &rq->hrtick_csd, 0); |
31656519 PZ |
1224 | rq->hrtick_csd_pending = 1; |
1225 | } | |
b328ca18 PZ |
1226 | } |
1227 | ||
1228 | static int | |
1229 | hotplug_hrtick(struct notifier_block *nfb, unsigned long action, void *hcpu) | |
1230 | { | |
1231 | int cpu = (int)(long)hcpu; | |
1232 | ||
1233 | switch (action) { | |
1234 | case CPU_UP_CANCELED: | |
1235 | case CPU_UP_CANCELED_FROZEN: | |
1236 | case CPU_DOWN_PREPARE: | |
1237 | case CPU_DOWN_PREPARE_FROZEN: | |
1238 | case CPU_DEAD: | |
1239 | case CPU_DEAD_FROZEN: | |
31656519 | 1240 | hrtick_clear(cpu_rq(cpu)); |
b328ca18 PZ |
1241 | return NOTIFY_OK; |
1242 | } | |
1243 | ||
1244 | return NOTIFY_DONE; | |
1245 | } | |
1246 | ||
fa748203 | 1247 | static __init void init_hrtick(void) |
b328ca18 PZ |
1248 | { |
1249 | hotcpu_notifier(hotplug_hrtick, 0); | |
1250 | } | |
31656519 PZ |
1251 | #else |
1252 | /* | |
1253 | * Called to set the hrtick timer state. | |
1254 | * | |
1255 | * called with rq->lock held and irqs disabled | |
1256 | */ | |
1257 | static void hrtick_start(struct rq *rq, u64 delay) | |
1258 | { | |
7f1e2ca9 | 1259 | __hrtimer_start_range_ns(&rq->hrtick_timer, ns_to_ktime(delay), 0, |
5c333864 | 1260 | HRTIMER_MODE_REL_PINNED, 0); |
31656519 | 1261 | } |
b328ca18 | 1262 | |
006c75f1 | 1263 | static inline void init_hrtick(void) |
8f4d37ec | 1264 | { |
8f4d37ec | 1265 | } |
31656519 | 1266 | #endif /* CONFIG_SMP */ |
8f4d37ec | 1267 | |
31656519 | 1268 | static void init_rq_hrtick(struct rq *rq) |
8f4d37ec | 1269 | { |
31656519 PZ |
1270 | #ifdef CONFIG_SMP |
1271 | rq->hrtick_csd_pending = 0; | |
8f4d37ec | 1272 | |
31656519 PZ |
1273 | rq->hrtick_csd.flags = 0; |
1274 | rq->hrtick_csd.func = __hrtick_start; | |
1275 | rq->hrtick_csd.info = rq; | |
1276 | #endif | |
8f4d37ec | 1277 | |
31656519 PZ |
1278 | hrtimer_init(&rq->hrtick_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); |
1279 | rq->hrtick_timer.function = hrtick; | |
8f4d37ec | 1280 | } |
006c75f1 | 1281 | #else /* CONFIG_SCHED_HRTICK */ |
8f4d37ec PZ |
1282 | static inline void hrtick_clear(struct rq *rq) |
1283 | { | |
1284 | } | |
1285 | ||
8f4d37ec PZ |
1286 | static inline void init_rq_hrtick(struct rq *rq) |
1287 | { | |
1288 | } | |
1289 | ||
b328ca18 PZ |
1290 | static inline void init_hrtick(void) |
1291 | { | |
1292 | } | |
006c75f1 | 1293 | #endif /* CONFIG_SCHED_HRTICK */ |
8f4d37ec | 1294 | |
c24d20db IM |
1295 | /* |
1296 | * resched_task - mark a task 'to be rescheduled now'. | |
1297 | * | |
1298 | * On UP this means the setting of the need_resched flag, on SMP it | |
1299 | * might also involve a cross-CPU call to trigger the scheduler on | |
1300 | * the target CPU. | |
1301 | */ | |
1302 | #ifdef CONFIG_SMP | |
1303 | ||
1304 | #ifndef tsk_is_polling | |
1305 | #define tsk_is_polling(t) test_tsk_thread_flag(t, TIF_POLLING_NRFLAG) | |
1306 | #endif | |
1307 | ||
31656519 | 1308 | static void resched_task(struct task_struct *p) |
c24d20db IM |
1309 | { |
1310 | int cpu; | |
1311 | ||
05fa785c | 1312 | assert_raw_spin_locked(&task_rq(p)->lock); |
c24d20db | 1313 | |
5ed0cec0 | 1314 | if (test_tsk_need_resched(p)) |
c24d20db IM |
1315 | return; |
1316 | ||
5ed0cec0 | 1317 | set_tsk_need_resched(p); |
c24d20db IM |
1318 | |
1319 | cpu = task_cpu(p); | |
1320 | if (cpu == smp_processor_id()) | |
1321 | return; | |
1322 | ||
1323 | /* NEED_RESCHED must be visible before we test polling */ | |
1324 | smp_mb(); | |
1325 | if (!tsk_is_polling(p)) | |
1326 | smp_send_reschedule(cpu); | |
1327 | } | |
1328 | ||
1329 | static void resched_cpu(int cpu) | |
1330 | { | |
1331 | struct rq *rq = cpu_rq(cpu); | |
1332 | unsigned long flags; | |
1333 | ||
05fa785c | 1334 | if (!raw_spin_trylock_irqsave(&rq->lock, flags)) |
c24d20db IM |
1335 | return; |
1336 | resched_task(cpu_curr(cpu)); | |
05fa785c | 1337 | raw_spin_unlock_irqrestore(&rq->lock, flags); |
c24d20db | 1338 | } |
06d8308c TG |
1339 | |
1340 | #ifdef CONFIG_NO_HZ | |
83cd4fe2 VP |
1341 | /* |
1342 | * In the semi idle case, use the nearest busy cpu for migrating timers | |
1343 | * from an idle cpu. This is good for power-savings. | |
1344 | * | |
1345 | * We don't do similar optimization for completely idle system, as | |
1346 | * selecting an idle cpu will add more delays to the timers than intended | |
1347 | * (as that cpu's timer base may not be uptodate wrt jiffies etc). | |
1348 | */ | |
1349 | int get_nohz_timer_target(void) | |
1350 | { | |
1351 | int cpu = smp_processor_id(); | |
1352 | int i; | |
1353 | struct sched_domain *sd; | |
1354 | ||
057f3fad | 1355 | rcu_read_lock(); |
83cd4fe2 | 1356 | for_each_domain(cpu, sd) { |
057f3fad PZ |
1357 | for_each_cpu(i, sched_domain_span(sd)) { |
1358 | if (!idle_cpu(i)) { | |
1359 | cpu = i; | |
1360 | goto unlock; | |
1361 | } | |
1362 | } | |
83cd4fe2 | 1363 | } |
057f3fad PZ |
1364 | unlock: |
1365 | rcu_read_unlock(); | |
83cd4fe2 VP |
1366 | return cpu; |
1367 | } | |
06d8308c TG |
1368 | /* |
1369 | * When add_timer_on() enqueues a timer into the timer wheel of an | |
1370 | * idle CPU then this timer might expire before the next timer event | |
1371 | * which is scheduled to wake up that CPU. In case of a completely | |
1372 | * idle system the next event might even be infinite time into the | |
1373 | * future. wake_up_idle_cpu() ensures that the CPU is woken up and | |
1374 | * leaves the inner idle loop so the newly added timer is taken into | |
1375 | * account when the CPU goes back to idle and evaluates the timer | |
1376 | * wheel for the next timer event. | |
1377 | */ | |
1378 | void wake_up_idle_cpu(int cpu) | |
1379 | { | |
1380 | struct rq *rq = cpu_rq(cpu); | |
1381 | ||
1382 | if (cpu == smp_processor_id()) | |
1383 | return; | |
1384 | ||
1385 | /* | |
1386 | * This is safe, as this function is called with the timer | |
1387 | * wheel base lock of (cpu) held. When the CPU is on the way | |
1388 | * to idle and has not yet set rq->curr to idle then it will | |
1389 | * be serialized on the timer wheel base lock and take the new | |
1390 | * timer into account automatically. | |
1391 | */ | |
1392 | if (rq->curr != rq->idle) | |
1393 | return; | |
1394 | ||
1395 | /* | |
1396 | * We can set TIF_RESCHED on the idle task of the other CPU | |
1397 | * lockless. The worst case is that the other CPU runs the | |
1398 | * idle task through an additional NOOP schedule() | |
1399 | */ | |
5ed0cec0 | 1400 | set_tsk_need_resched(rq->idle); |
06d8308c TG |
1401 | |
1402 | /* NEED_RESCHED must be visible before we test polling */ | |
1403 | smp_mb(); | |
1404 | if (!tsk_is_polling(rq->idle)) | |
1405 | smp_send_reschedule(cpu); | |
1406 | } | |
39c0cbe2 | 1407 | |
ca38062e SS |
1408 | static inline bool got_nohz_idle_kick(void) |
1409 | { | |
1410 | return idle_cpu(smp_processor_id()) && this_rq()->nohz_balance_kick; | |
1411 | } | |
1412 | ||
1413 | #else /* CONFIG_NO_HZ */ | |
1414 | ||
1415 | static inline bool got_nohz_idle_kick(void) | |
1416 | { | |
1417 | return false; | |
1418 | } | |
1419 | ||
6d6bc0ad | 1420 | #endif /* CONFIG_NO_HZ */ |
06d8308c | 1421 | |
e9e9250b PZ |
1422 | static u64 sched_avg_period(void) |
1423 | { | |
1424 | return (u64)sysctl_sched_time_avg * NSEC_PER_MSEC / 2; | |
1425 | } | |
1426 | ||
1427 | static void sched_avg_update(struct rq *rq) | |
1428 | { | |
1429 | s64 period = sched_avg_period(); | |
1430 | ||
1431 | while ((s64)(rq->clock - rq->age_stamp) > period) { | |
0d98bb26 WD |
1432 | /* |
1433 | * Inline assembly required to prevent the compiler | |
1434 | * optimising this loop into a divmod call. | |
1435 | * See __iter_div_u64_rem() for another example of this. | |
1436 | */ | |
1437 | asm("" : "+rm" (rq->age_stamp)); | |
e9e9250b PZ |
1438 | rq->age_stamp += period; |
1439 | rq->rt_avg /= 2; | |
1440 | } | |
1441 | } | |
1442 | ||
1443 | static void sched_rt_avg_update(struct rq *rq, u64 rt_delta) | |
1444 | { | |
1445 | rq->rt_avg += rt_delta; | |
1446 | sched_avg_update(rq); | |
1447 | } | |
1448 | ||
6d6bc0ad | 1449 | #else /* !CONFIG_SMP */ |
31656519 | 1450 | static void resched_task(struct task_struct *p) |
c24d20db | 1451 | { |
05fa785c | 1452 | assert_raw_spin_locked(&task_rq(p)->lock); |
31656519 | 1453 | set_tsk_need_resched(p); |
c24d20db | 1454 | } |
e9e9250b PZ |
1455 | |
1456 | static void sched_rt_avg_update(struct rq *rq, u64 rt_delta) | |
1457 | { | |
1458 | } | |
da2b71ed SS |
1459 | |
1460 | static void sched_avg_update(struct rq *rq) | |
1461 | { | |
1462 | } | |
6d6bc0ad | 1463 | #endif /* CONFIG_SMP */ |
c24d20db | 1464 | |
45bf76df IM |
1465 | #if BITS_PER_LONG == 32 |
1466 | # define WMULT_CONST (~0UL) | |
1467 | #else | |
1468 | # define WMULT_CONST (1UL << 32) | |
1469 | #endif | |
1470 | ||
1471 | #define WMULT_SHIFT 32 | |
1472 | ||
194081eb IM |
1473 | /* |
1474 | * Shift right and round: | |
1475 | */ | |
cf2ab469 | 1476 | #define SRR(x, y) (((x) + (1UL << ((y) - 1))) >> (y)) |
194081eb | 1477 | |
a7be37ac PZ |
1478 | /* |
1479 | * delta *= weight / lw | |
1480 | */ | |
cb1c4fc9 | 1481 | static unsigned long |
45bf76df IM |
1482 | calc_delta_mine(unsigned long delta_exec, unsigned long weight, |
1483 | struct load_weight *lw) | |
1484 | { | |
1485 | u64 tmp; | |
1486 | ||
c8b28116 NR |
1487 | /* |
1488 | * weight can be less than 2^SCHED_LOAD_RESOLUTION for task group sched | |
1489 | * entities since MIN_SHARES = 2. Treat weight as 1 if less than | |
1490 | * 2^SCHED_LOAD_RESOLUTION. | |
1491 | */ | |
1492 | if (likely(weight > (1UL << SCHED_LOAD_RESOLUTION))) | |
1493 | tmp = (u64)delta_exec * scale_load_down(weight); | |
1494 | else | |
1495 | tmp = (u64)delta_exec; | |
db670dac | 1496 | |
7a232e03 | 1497 | if (!lw->inv_weight) { |
c8b28116 NR |
1498 | unsigned long w = scale_load_down(lw->weight); |
1499 | ||
1500 | if (BITS_PER_LONG > 32 && unlikely(w >= WMULT_CONST)) | |
7a232e03 | 1501 | lw->inv_weight = 1; |
c8b28116 NR |
1502 | else if (unlikely(!w)) |
1503 | lw->inv_weight = WMULT_CONST; | |
7a232e03 | 1504 | else |
c8b28116 | 1505 | lw->inv_weight = WMULT_CONST / w; |
7a232e03 | 1506 | } |
45bf76df | 1507 | |
45bf76df IM |
1508 | /* |
1509 | * Check whether we'd overflow the 64-bit multiplication: | |
1510 | */ | |
194081eb | 1511 | if (unlikely(tmp > WMULT_CONST)) |
cf2ab469 | 1512 | tmp = SRR(SRR(tmp, WMULT_SHIFT/2) * lw->inv_weight, |
194081eb IM |
1513 | WMULT_SHIFT/2); |
1514 | else | |
cf2ab469 | 1515 | tmp = SRR(tmp * lw->inv_weight, WMULT_SHIFT); |
45bf76df | 1516 | |
ecf691da | 1517 | return (unsigned long)min(tmp, (u64)(unsigned long)LONG_MAX); |
45bf76df IM |
1518 | } |
1519 | ||
1091985b | 1520 | static inline void update_load_add(struct load_weight *lw, unsigned long inc) |
45bf76df IM |
1521 | { |
1522 | lw->weight += inc; | |
e89996ae | 1523 | lw->inv_weight = 0; |
45bf76df IM |
1524 | } |
1525 | ||
1091985b | 1526 | static inline void update_load_sub(struct load_weight *lw, unsigned long dec) |
45bf76df IM |
1527 | { |
1528 | lw->weight -= dec; | |
e89996ae | 1529 | lw->inv_weight = 0; |
45bf76df IM |
1530 | } |
1531 | ||
2069dd75 PZ |
1532 | static inline void update_load_set(struct load_weight *lw, unsigned long w) |
1533 | { | |
1534 | lw->weight = w; | |
1535 | lw->inv_weight = 0; | |
1536 | } | |
1537 | ||
2dd73a4f PW |
1538 | /* |
1539 | * To aid in avoiding the subversion of "niceness" due to uneven distribution | |
1540 | * of tasks with abnormal "nice" values across CPUs the contribution that | |
1541 | * each task makes to its run queue's load is weighted according to its | |
41a2d6cf | 1542 | * scheduling class and "nice" value. For SCHED_NORMAL tasks this is just a |
2dd73a4f PW |
1543 | * scaled version of the new time slice allocation that they receive on time |
1544 | * slice expiry etc. | |
1545 | */ | |
1546 | ||
cce7ade8 PZ |
1547 | #define WEIGHT_IDLEPRIO 3 |
1548 | #define WMULT_IDLEPRIO 1431655765 | |
dd41f596 IM |
1549 | |
1550 | /* | |
1551 | * Nice levels are multiplicative, with a gentle 10% change for every | |
1552 | * nice level changed. I.e. when a CPU-bound task goes from nice 0 to | |
1553 | * nice 1, it will get ~10% less CPU time than another CPU-bound task | |
1554 | * that remained on nice 0. | |
1555 | * | |
1556 | * The "10% effect" is relative and cumulative: from _any_ nice level, | |
1557 | * if you go up 1 level, it's -10% CPU usage, if you go down 1 level | |
f9153ee6 IM |
1558 | * it's +10% CPU usage. (to achieve that we use a multiplier of 1.25. |
1559 | * If a task goes up by ~10% and another task goes down by ~10% then | |
1560 | * the relative distance between them is ~25%.) | |
dd41f596 IM |
1561 | */ |
1562 | static const int prio_to_weight[40] = { | |
254753dc IM |
1563 | /* -20 */ 88761, 71755, 56483, 46273, 36291, |
1564 | /* -15 */ 29154, 23254, 18705, 14949, 11916, | |
1565 | /* -10 */ 9548, 7620, 6100, 4904, 3906, | |
1566 | /* -5 */ 3121, 2501, 1991, 1586, 1277, | |
1567 | /* 0 */ 1024, 820, 655, 526, 423, | |
1568 | /* 5 */ 335, 272, 215, 172, 137, | |
1569 | /* 10 */ 110, 87, 70, 56, 45, | |
1570 | /* 15 */ 36, 29, 23, 18, 15, | |
dd41f596 IM |
1571 | }; |
1572 | ||
5714d2de IM |
1573 | /* |
1574 | * Inverse (2^32/x) values of the prio_to_weight[] array, precalculated. | |
1575 | * | |
1576 | * In cases where the weight does not change often, we can use the | |
1577 | * precalculated inverse to speed up arithmetics by turning divisions | |
1578 | * into multiplications: | |
1579 | */ | |
dd41f596 | 1580 | static const u32 prio_to_wmult[40] = { |
254753dc IM |
1581 | /* -20 */ 48388, 59856, 76040, 92818, 118348, |
1582 | /* -15 */ 147320, 184698, 229616, 287308, 360437, | |
1583 | /* -10 */ 449829, 563644, 704093, 875809, 1099582, | |
1584 | /* -5 */ 1376151, 1717300, 2157191, 2708050, 3363326, | |
1585 | /* 0 */ 4194304, 5237765, 6557202, 8165337, 10153587, | |
1586 | /* 5 */ 12820798, 15790321, 19976592, 24970740, 31350126, | |
1587 | /* 10 */ 39045157, 49367440, 61356676, 76695844, 95443717, | |
1588 | /* 15 */ 119304647, 148102320, 186737708, 238609294, 286331153, | |
dd41f596 | 1589 | }; |
2dd73a4f | 1590 | |
ef12fefa BR |
1591 | /* Time spent by the tasks of the cpu accounting group executing in ... */ |
1592 | enum cpuacct_stat_index { | |
1593 | CPUACCT_STAT_USER, /* ... user mode */ | |
1594 | CPUACCT_STAT_SYSTEM, /* ... kernel mode */ | |
1595 | ||
1596 | CPUACCT_STAT_NSTATS, | |
1597 | }; | |
1598 | ||
d842de87 SV |
1599 | #ifdef CONFIG_CGROUP_CPUACCT |
1600 | static void cpuacct_charge(struct task_struct *tsk, u64 cputime); | |
ef12fefa BR |
1601 | static void cpuacct_update_stats(struct task_struct *tsk, |
1602 | enum cpuacct_stat_index idx, cputime_t val); | |
d842de87 SV |
1603 | #else |
1604 | static inline void cpuacct_charge(struct task_struct *tsk, u64 cputime) {} | |
ef12fefa BR |
1605 | static inline void cpuacct_update_stats(struct task_struct *tsk, |
1606 | enum cpuacct_stat_index idx, cputime_t val) {} | |
d842de87 SV |
1607 | #endif |
1608 | ||
18d95a28 PZ |
1609 | static inline void inc_cpu_load(struct rq *rq, unsigned long load) |
1610 | { | |
1611 | update_load_add(&rq->load, load); | |
1612 | } | |
1613 | ||
1614 | static inline void dec_cpu_load(struct rq *rq, unsigned long load) | |
1615 | { | |
1616 | update_load_sub(&rq->load, load); | |
1617 | } | |
1618 | ||
a790de99 PT |
1619 | #if defined(CONFIG_RT_GROUP_SCHED) || (defined(CONFIG_FAIR_GROUP_SCHED) && \ |
1620 | (defined(CONFIG_SMP) || defined(CONFIG_CFS_BANDWIDTH))) | |
eb755805 | 1621 | typedef int (*tg_visitor)(struct task_group *, void *); |
c09595f6 PZ |
1622 | |
1623 | /* | |
8277434e PT |
1624 | * Iterate task_group tree rooted at *from, calling @down when first entering a |
1625 | * node and @up when leaving it for the final time. | |
1626 | * | |
1627 | * Caller must hold rcu_lock or sufficient equivalent. | |
c09595f6 | 1628 | */ |
8277434e PT |
1629 | static int walk_tg_tree_from(struct task_group *from, |
1630 | tg_visitor down, tg_visitor up, void *data) | |
c09595f6 PZ |
1631 | { |
1632 | struct task_group *parent, *child; | |
eb755805 | 1633 | int ret; |
c09595f6 | 1634 | |
8277434e PT |
1635 | parent = from; |
1636 | ||
c09595f6 | 1637 | down: |
eb755805 PZ |
1638 | ret = (*down)(parent, data); |
1639 | if (ret) | |
8277434e | 1640 | goto out; |
c09595f6 PZ |
1641 | list_for_each_entry_rcu(child, &parent->children, siblings) { |
1642 | parent = child; | |
1643 | goto down; | |
1644 | ||
1645 | up: | |
1646 | continue; | |
1647 | } | |
eb755805 | 1648 | ret = (*up)(parent, data); |
8277434e PT |
1649 | if (ret || parent == from) |
1650 | goto out; | |
c09595f6 PZ |
1651 | |
1652 | child = parent; | |
1653 | parent = parent->parent; | |
1654 | if (parent) | |
1655 | goto up; | |
8277434e | 1656 | out: |
eb755805 | 1657 | return ret; |
c09595f6 PZ |
1658 | } |
1659 | ||
8277434e PT |
1660 | /* |
1661 | * Iterate the full tree, calling @down when first entering a node and @up when | |
1662 | * leaving it for the final time. | |
1663 | * | |
1664 | * Caller must hold rcu_lock or sufficient equivalent. | |
1665 | */ | |
1666 | ||
1667 | static inline int walk_tg_tree(tg_visitor down, tg_visitor up, void *data) | |
1668 | { | |
1669 | return walk_tg_tree_from(&root_task_group, down, up, data); | |
1670 | } | |
1671 | ||
eb755805 PZ |
1672 | static int tg_nop(struct task_group *tg, void *data) |
1673 | { | |
1674 | return 0; | |
c09595f6 | 1675 | } |
eb755805 PZ |
1676 | #endif |
1677 | ||
1678 | #ifdef CONFIG_SMP | |
f5f08f39 PZ |
1679 | /* Used instead of source_load when we know the type == 0 */ |
1680 | static unsigned long weighted_cpuload(const int cpu) | |
1681 | { | |
1682 | return cpu_rq(cpu)->load.weight; | |
1683 | } | |
1684 | ||
1685 | /* | |
1686 | * Return a low guess at the load of a migration-source cpu weighted | |
1687 | * according to the scheduling class and "nice" value. | |
1688 | * | |
1689 | * We want to under-estimate the load of migration sources, to | |
1690 | * balance conservatively. | |
1691 | */ | |
1692 | static unsigned long source_load(int cpu, int type) | |
1693 | { | |
1694 | struct rq *rq = cpu_rq(cpu); | |
1695 | unsigned long total = weighted_cpuload(cpu); | |
1696 | ||
1697 | if (type == 0 || !sched_feat(LB_BIAS)) | |
1698 | return total; | |
1699 | ||
1700 | return min(rq->cpu_load[type-1], total); | |
1701 | } | |
1702 | ||
1703 | /* | |
1704 | * Return a high guess at the load of a migration-target cpu weighted | |
1705 | * according to the scheduling class and "nice" value. | |
1706 | */ | |
1707 | static unsigned long target_load(int cpu, int type) | |
1708 | { | |
1709 | struct rq *rq = cpu_rq(cpu); | |
1710 | unsigned long total = weighted_cpuload(cpu); | |
1711 | ||
1712 | if (type == 0 || !sched_feat(LB_BIAS)) | |
1713 | return total; | |
1714 | ||
1715 | return max(rq->cpu_load[type-1], total); | |
1716 | } | |
1717 | ||
ae154be1 PZ |
1718 | static unsigned long power_of(int cpu) |
1719 | { | |
e51fd5e2 | 1720 | return cpu_rq(cpu)->cpu_power; |
ae154be1 PZ |
1721 | } |
1722 | ||
eb755805 PZ |
1723 | static int task_hot(struct task_struct *p, u64 now, struct sched_domain *sd); |
1724 | ||
1725 | static unsigned long cpu_avg_load_per_task(int cpu) | |
1726 | { | |
1727 | struct rq *rq = cpu_rq(cpu); | |
af6d596f | 1728 | unsigned long nr_running = ACCESS_ONCE(rq->nr_running); |
eb755805 | 1729 | |
4cd42620 | 1730 | if (nr_running) |
e2b245f8 | 1731 | return rq->load.weight / nr_running; |
eb755805 | 1732 | |
e2b245f8 | 1733 | return 0; |
eb755805 PZ |
1734 | } |
1735 | ||
8f45e2b5 GH |
1736 | #ifdef CONFIG_PREEMPT |
1737 | ||
b78bb868 PZ |
1738 | static void double_rq_lock(struct rq *rq1, struct rq *rq2); |
1739 | ||
70574a99 | 1740 | /* |
8f45e2b5 GH |
1741 | * fair double_lock_balance: Safely acquires both rq->locks in a fair |
1742 | * way at the expense of forcing extra atomic operations in all | |
1743 | * invocations. This assures that the double_lock is acquired using the | |
1744 | * same underlying policy as the spinlock_t on this architecture, which | |
1745 | * reduces latency compared to the unfair variant below. However, it | |
1746 | * also adds more overhead and therefore may reduce throughput. | |
70574a99 | 1747 | */ |
8f45e2b5 GH |
1748 | static inline int _double_lock_balance(struct rq *this_rq, struct rq *busiest) |
1749 | __releases(this_rq->lock) | |
1750 | __acquires(busiest->lock) | |
1751 | __acquires(this_rq->lock) | |
1752 | { | |
05fa785c | 1753 | raw_spin_unlock(&this_rq->lock); |
8f45e2b5 GH |
1754 | double_rq_lock(this_rq, busiest); |
1755 | ||
1756 | return 1; | |
1757 | } | |
1758 | ||
1759 | #else | |
1760 | /* | |
1761 | * Unfair double_lock_balance: Optimizes throughput at the expense of | |
1762 | * latency by eliminating extra atomic operations when the locks are | |
1763 | * already in proper order on entry. This favors lower cpu-ids and will | |
1764 | * grant the double lock to lower cpus over higher ids under contention, | |
1765 | * regardless of entry order into the function. | |
1766 | */ | |
1767 | static int _double_lock_balance(struct rq *this_rq, struct rq *busiest) | |
70574a99 AD |
1768 | __releases(this_rq->lock) |
1769 | __acquires(busiest->lock) | |
1770 | __acquires(this_rq->lock) | |
1771 | { | |
1772 | int ret = 0; | |
1773 | ||
05fa785c | 1774 | if (unlikely(!raw_spin_trylock(&busiest->lock))) { |
70574a99 | 1775 | if (busiest < this_rq) { |
05fa785c TG |
1776 | raw_spin_unlock(&this_rq->lock); |
1777 | raw_spin_lock(&busiest->lock); | |
1778 | raw_spin_lock_nested(&this_rq->lock, | |
1779 | SINGLE_DEPTH_NESTING); | |
70574a99 AD |
1780 | ret = 1; |
1781 | } else | |
05fa785c TG |
1782 | raw_spin_lock_nested(&busiest->lock, |
1783 | SINGLE_DEPTH_NESTING); | |
70574a99 AD |
1784 | } |
1785 | return ret; | |
1786 | } | |
1787 | ||
8f45e2b5 GH |
1788 | #endif /* CONFIG_PREEMPT */ |
1789 | ||
1790 | /* | |
1791 | * double_lock_balance - lock the busiest runqueue, this_rq is locked already. | |
1792 | */ | |
1793 | static int double_lock_balance(struct rq *this_rq, struct rq *busiest) | |
1794 | { | |
1795 | if (unlikely(!irqs_disabled())) { | |
1796 | /* printk() doesn't work good under rq->lock */ | |
05fa785c | 1797 | raw_spin_unlock(&this_rq->lock); |
8f45e2b5 GH |
1798 | BUG_ON(1); |
1799 | } | |
1800 | ||
1801 | return _double_lock_balance(this_rq, busiest); | |
1802 | } | |
1803 | ||
70574a99 AD |
1804 | static inline void double_unlock_balance(struct rq *this_rq, struct rq *busiest) |
1805 | __releases(busiest->lock) | |
1806 | { | |
05fa785c | 1807 | raw_spin_unlock(&busiest->lock); |
70574a99 AD |
1808 | lock_set_subclass(&this_rq->lock.dep_map, 0, _RET_IP_); |
1809 | } | |
1e3c88bd PZ |
1810 | |
1811 | /* | |
1812 | * double_rq_lock - safely lock two runqueues | |
1813 | * | |
1814 | * Note this does not disable interrupts like task_rq_lock, | |
1815 | * you need to do so manually before calling. | |
1816 | */ | |
1817 | static void double_rq_lock(struct rq *rq1, struct rq *rq2) | |
1818 | __acquires(rq1->lock) | |
1819 | __acquires(rq2->lock) | |
1820 | { | |
1821 | BUG_ON(!irqs_disabled()); | |
1822 | if (rq1 == rq2) { | |
1823 | raw_spin_lock(&rq1->lock); | |
1824 | __acquire(rq2->lock); /* Fake it out ;) */ | |
1825 | } else { | |
1826 | if (rq1 < rq2) { | |
1827 | raw_spin_lock(&rq1->lock); | |
1828 | raw_spin_lock_nested(&rq2->lock, SINGLE_DEPTH_NESTING); | |
1829 | } else { | |
1830 | raw_spin_lock(&rq2->lock); | |
1831 | raw_spin_lock_nested(&rq1->lock, SINGLE_DEPTH_NESTING); | |
1832 | } | |
1833 | } | |
1e3c88bd PZ |
1834 | } |
1835 | ||
1836 | /* | |
1837 | * double_rq_unlock - safely unlock two runqueues | |
1838 | * | |
1839 | * Note this does not restore interrupts like task_rq_unlock, | |
1840 | * you need to do so manually after calling. | |
1841 | */ | |
1842 | static void double_rq_unlock(struct rq *rq1, struct rq *rq2) | |
1843 | __releases(rq1->lock) | |
1844 | __releases(rq2->lock) | |
1845 | { | |
1846 | raw_spin_unlock(&rq1->lock); | |
1847 | if (rq1 != rq2) | |
1848 | raw_spin_unlock(&rq2->lock); | |
1849 | else | |
1850 | __release(rq2->lock); | |
1851 | } | |
1852 | ||
d95f4122 MG |
1853 | #else /* CONFIG_SMP */ |
1854 | ||
1855 | /* | |
1856 | * double_rq_lock - safely lock two runqueues | |
1857 | * | |
1858 | * Note this does not disable interrupts like task_rq_lock, | |
1859 | * you need to do so manually before calling. | |
1860 | */ | |
1861 | static void double_rq_lock(struct rq *rq1, struct rq *rq2) | |
1862 | __acquires(rq1->lock) | |
1863 | __acquires(rq2->lock) | |
1864 | { | |
1865 | BUG_ON(!irqs_disabled()); | |
1866 | BUG_ON(rq1 != rq2); | |
1867 | raw_spin_lock(&rq1->lock); | |
1868 | __acquire(rq2->lock); /* Fake it out ;) */ | |
1869 | } | |
1870 | ||
1871 | /* | |
1872 | * double_rq_unlock - safely unlock two runqueues | |
1873 | * | |
1874 | * Note this does not restore interrupts like task_rq_unlock, | |
1875 | * you need to do so manually after calling. | |
1876 | */ | |
1877 | static void double_rq_unlock(struct rq *rq1, struct rq *rq2) | |
1878 | __releases(rq1->lock) | |
1879 | __releases(rq2->lock) | |
1880 | { | |
1881 | BUG_ON(rq1 != rq2); | |
1882 | raw_spin_unlock(&rq1->lock); | |
1883 | __release(rq2->lock); | |
1884 | } | |
1885 | ||
18d95a28 PZ |
1886 | #endif |
1887 | ||
74f5187a | 1888 | static void calc_load_account_idle(struct rq *this_rq); |
0bcdcf28 | 1889 | static void update_sysctl(void); |
acb4a848 | 1890 | static int get_update_sysctl_factor(void); |
fdf3e95d | 1891 | static void update_cpu_load(struct rq *this_rq); |
dce48a84 | 1892 | |
cd29fe6f PZ |
1893 | static inline void __set_task_cpu(struct task_struct *p, unsigned int cpu) |
1894 | { | |
1895 | set_task_rq(p, cpu); | |
1896 | #ifdef CONFIG_SMP | |
1897 | /* | |
1898 | * After ->cpu is set up to a new value, task_rq_lock(p, ...) can be | |
bfb9035c | 1899 | * successfully executed on another CPU. We must ensure that updates of |
cd29fe6f PZ |
1900 | * per-task data have been completed by this moment. |
1901 | */ | |
1902 | smp_wmb(); | |
1903 | task_thread_info(p)->cpu = cpu; | |
1904 | #endif | |
1905 | } | |
dce48a84 | 1906 | |
1e3c88bd | 1907 | static const struct sched_class rt_sched_class; |
dd41f596 | 1908 | |
34f971f6 | 1909 | #define sched_class_highest (&stop_sched_class) |
1f11eb6a GH |
1910 | #define for_each_class(class) \ |
1911 | for (class = sched_class_highest; class; class = class->next) | |
dd41f596 | 1912 | |
1e3c88bd PZ |
1913 | #include "sched_stats.h" |
1914 | ||
c09595f6 | 1915 | static void inc_nr_running(struct rq *rq) |
9c217245 IM |
1916 | { |
1917 | rq->nr_running++; | |
9c217245 IM |
1918 | } |
1919 | ||
c09595f6 | 1920 | static void dec_nr_running(struct rq *rq) |
9c217245 IM |
1921 | { |
1922 | rq->nr_running--; | |
9c217245 IM |
1923 | } |
1924 | ||
45bf76df IM |
1925 | static void set_load_weight(struct task_struct *p) |
1926 | { | |
f05998d4 NR |
1927 | int prio = p->static_prio - MAX_RT_PRIO; |
1928 | struct load_weight *load = &p->se.load; | |
1929 | ||
dd41f596 IM |
1930 | /* |
1931 | * SCHED_IDLE tasks get minimal weight: | |
1932 | */ | |
1933 | if (p->policy == SCHED_IDLE) { | |
c8b28116 | 1934 | load->weight = scale_load(WEIGHT_IDLEPRIO); |
f05998d4 | 1935 | load->inv_weight = WMULT_IDLEPRIO; |
dd41f596 IM |
1936 | return; |
1937 | } | |
71f8bd46 | 1938 | |
c8b28116 | 1939 | load->weight = scale_load(prio_to_weight[prio]); |
f05998d4 | 1940 | load->inv_weight = prio_to_wmult[prio]; |
71f8bd46 IM |
1941 | } |
1942 | ||
371fd7e7 | 1943 | static void enqueue_task(struct rq *rq, struct task_struct *p, int flags) |
2087a1ad | 1944 | { |
a64692a3 | 1945 | update_rq_clock(rq); |
dd41f596 | 1946 | sched_info_queued(p); |
371fd7e7 | 1947 | p->sched_class->enqueue_task(rq, p, flags); |
71f8bd46 IM |
1948 | } |
1949 | ||
371fd7e7 | 1950 | static void dequeue_task(struct rq *rq, struct task_struct *p, int flags) |
71f8bd46 | 1951 | { |
a64692a3 | 1952 | update_rq_clock(rq); |
46ac22ba | 1953 | sched_info_dequeued(p); |
371fd7e7 | 1954 | p->sched_class->dequeue_task(rq, p, flags); |
71f8bd46 IM |
1955 | } |
1956 | ||
1e3c88bd PZ |
1957 | /* |
1958 | * activate_task - move a task to the runqueue. | |
1959 | */ | |
371fd7e7 | 1960 | static void activate_task(struct rq *rq, struct task_struct *p, int flags) |
1e3c88bd PZ |
1961 | { |
1962 | if (task_contributes_to_load(p)) | |
1963 | rq->nr_uninterruptible--; | |
1964 | ||
371fd7e7 | 1965 | enqueue_task(rq, p, flags); |
1e3c88bd PZ |
1966 | } |
1967 | ||
1968 | /* | |
1969 | * deactivate_task - remove a task from the runqueue. | |
1970 | */ | |
371fd7e7 | 1971 | static void deactivate_task(struct rq *rq, struct task_struct *p, int flags) |
1e3c88bd PZ |
1972 | { |
1973 | if (task_contributes_to_load(p)) | |
1974 | rq->nr_uninterruptible++; | |
1975 | ||
371fd7e7 | 1976 | dequeue_task(rq, p, flags); |
1e3c88bd PZ |
1977 | } |
1978 | ||
b52bfee4 VP |
1979 | #ifdef CONFIG_IRQ_TIME_ACCOUNTING |
1980 | ||
305e6835 VP |
1981 | /* |
1982 | * There are no locks covering percpu hardirq/softirq time. | |
1983 | * They are only modified in account_system_vtime, on corresponding CPU | |
1984 | * with interrupts disabled. So, writes are safe. | |
1985 | * They are read and saved off onto struct rq in update_rq_clock(). | |
1986 | * This may result in other CPU reading this CPU's irq time and can | |
1987 | * race with irq/account_system_vtime on this CPU. We would either get old | |
8e92c201 PZ |
1988 | * or new value with a side effect of accounting a slice of irq time to wrong |
1989 | * task when irq is in progress while we read rq->clock. That is a worthy | |
1990 | * compromise in place of having locks on each irq in account_system_time. | |
305e6835 | 1991 | */ |
b52bfee4 VP |
1992 | static DEFINE_PER_CPU(u64, cpu_hardirq_time); |
1993 | static DEFINE_PER_CPU(u64, cpu_softirq_time); | |
1994 | ||
1995 | static DEFINE_PER_CPU(u64, irq_start_time); | |
1996 | static int sched_clock_irqtime; | |
1997 | ||
1998 | void enable_sched_clock_irqtime(void) | |
1999 | { | |
2000 | sched_clock_irqtime = 1; | |
2001 | } | |
2002 | ||
2003 | void disable_sched_clock_irqtime(void) | |
2004 | { | |
2005 | sched_clock_irqtime = 0; | |
2006 | } | |
2007 | ||
8e92c201 PZ |
2008 | #ifndef CONFIG_64BIT |
2009 | static DEFINE_PER_CPU(seqcount_t, irq_time_seq); | |
2010 | ||
2011 | static inline void irq_time_write_begin(void) | |
2012 | { | |
2013 | __this_cpu_inc(irq_time_seq.sequence); | |
2014 | smp_wmb(); | |
2015 | } | |
2016 | ||
2017 | static inline void irq_time_write_end(void) | |
2018 | { | |
2019 | smp_wmb(); | |
2020 | __this_cpu_inc(irq_time_seq.sequence); | |
2021 | } | |
2022 | ||
2023 | static inline u64 irq_time_read(int cpu) | |
2024 | { | |
2025 | u64 irq_time; | |
2026 | unsigned seq; | |
2027 | ||
2028 | do { | |
2029 | seq = read_seqcount_begin(&per_cpu(irq_time_seq, cpu)); | |
2030 | irq_time = per_cpu(cpu_softirq_time, cpu) + | |
2031 | per_cpu(cpu_hardirq_time, cpu); | |
2032 | } while (read_seqcount_retry(&per_cpu(irq_time_seq, cpu), seq)); | |
2033 | ||
2034 | return irq_time; | |
2035 | } | |
2036 | #else /* CONFIG_64BIT */ | |
2037 | static inline void irq_time_write_begin(void) | |
2038 | { | |
2039 | } | |
2040 | ||
2041 | static inline void irq_time_write_end(void) | |
2042 | { | |
2043 | } | |
2044 | ||
2045 | static inline u64 irq_time_read(int cpu) | |
305e6835 | 2046 | { |
305e6835 VP |
2047 | return per_cpu(cpu_softirq_time, cpu) + per_cpu(cpu_hardirq_time, cpu); |
2048 | } | |
8e92c201 | 2049 | #endif /* CONFIG_64BIT */ |
305e6835 | 2050 | |
fe44d621 PZ |
2051 | /* |
2052 | * Called before incrementing preempt_count on {soft,}irq_enter | |
2053 | * and before decrementing preempt_count on {soft,}irq_exit. | |
2054 | */ | |
b52bfee4 VP |
2055 | void account_system_vtime(struct task_struct *curr) |
2056 | { | |
2057 | unsigned long flags; | |
fe44d621 | 2058 | s64 delta; |
b52bfee4 | 2059 | int cpu; |
b52bfee4 VP |
2060 | |
2061 | if (!sched_clock_irqtime) | |
2062 | return; | |
2063 | ||
2064 | local_irq_save(flags); | |
2065 | ||
b52bfee4 | 2066 | cpu = smp_processor_id(); |
fe44d621 PZ |
2067 | delta = sched_clock_cpu(cpu) - __this_cpu_read(irq_start_time); |
2068 | __this_cpu_add(irq_start_time, delta); | |
2069 | ||
8e92c201 | 2070 | irq_time_write_begin(); |
b52bfee4 VP |
2071 | /* |
2072 | * We do not account for softirq time from ksoftirqd here. | |
2073 | * We want to continue accounting softirq time to ksoftirqd thread | |
2074 | * in that case, so as not to confuse scheduler with a special task | |
2075 | * that do not consume any time, but still wants to run. | |
2076 | */ | |
2077 | if (hardirq_count()) | |
fe44d621 | 2078 | __this_cpu_add(cpu_hardirq_time, delta); |
4dd53d89 | 2079 | else if (in_serving_softirq() && curr != this_cpu_ksoftirqd()) |
fe44d621 | 2080 | __this_cpu_add(cpu_softirq_time, delta); |
b52bfee4 | 2081 | |
8e92c201 | 2082 | irq_time_write_end(); |
b52bfee4 VP |
2083 | local_irq_restore(flags); |
2084 | } | |
b7dadc38 | 2085 | EXPORT_SYMBOL_GPL(account_system_vtime); |
b52bfee4 | 2086 | |
e6e6685a GC |
2087 | #endif /* CONFIG_IRQ_TIME_ACCOUNTING */ |
2088 | ||
2089 | #ifdef CONFIG_PARAVIRT | |
2090 | static inline u64 steal_ticks(u64 steal) | |
aa483808 | 2091 | { |
e6e6685a GC |
2092 | if (unlikely(steal > NSEC_PER_SEC)) |
2093 | return div_u64(steal, TICK_NSEC); | |
fe44d621 | 2094 | |
e6e6685a GC |
2095 | return __iter_div_u64_rem(steal, TICK_NSEC, &steal); |
2096 | } | |
2097 | #endif | |
2098 | ||
fe44d621 | 2099 | static void update_rq_clock_task(struct rq *rq, s64 delta) |
aa483808 | 2100 | { |
095c0aa8 GC |
2101 | /* |
2102 | * In theory, the compile should just see 0 here, and optimize out the call | |
2103 | * to sched_rt_avg_update. But I don't trust it... | |
2104 | */ | |
2105 | #if defined(CONFIG_IRQ_TIME_ACCOUNTING) || defined(CONFIG_PARAVIRT_TIME_ACCOUNTING) | |
2106 | s64 steal = 0, irq_delta = 0; | |
2107 | #endif | |
2108 | #ifdef CONFIG_IRQ_TIME_ACCOUNTING | |
8e92c201 | 2109 | irq_delta = irq_time_read(cpu_of(rq)) - rq->prev_irq_time; |
fe44d621 PZ |
2110 | |
2111 | /* | |
2112 | * Since irq_time is only updated on {soft,}irq_exit, we might run into | |
2113 | * this case when a previous update_rq_clock() happened inside a | |
2114 | * {soft,}irq region. | |
2115 | * | |
2116 | * When this happens, we stop ->clock_task and only update the | |
2117 | * prev_irq_time stamp to account for the part that fit, so that a next | |
2118 | * update will consume the rest. This ensures ->clock_task is | |
2119 | * monotonic. | |
2120 | * | |
2121 | * It does however cause some slight miss-attribution of {soft,}irq | |
2122 | * time, a more accurate solution would be to update the irq_time using | |
2123 | * the current rq->clock timestamp, except that would require using | |
2124 | * atomic ops. | |
2125 | */ | |
2126 | if (irq_delta > delta) | |
2127 | irq_delta = delta; | |
2128 | ||
2129 | rq->prev_irq_time += irq_delta; | |
2130 | delta -= irq_delta; | |
095c0aa8 GC |
2131 | #endif |
2132 | #ifdef CONFIG_PARAVIRT_TIME_ACCOUNTING | |
2133 | if (static_branch((¶virt_steal_rq_enabled))) { | |
2134 | u64 st; | |
2135 | ||
2136 | steal = paravirt_steal_clock(cpu_of(rq)); | |
2137 | steal -= rq->prev_steal_time_rq; | |
2138 | ||
2139 | if (unlikely(steal > delta)) | |
2140 | steal = delta; | |
2141 | ||
2142 | st = steal_ticks(steal); | |
2143 | steal = st * TICK_NSEC; | |
2144 | ||
2145 | rq->prev_steal_time_rq += steal; | |
2146 | ||
2147 | delta -= steal; | |
2148 | } | |
2149 | #endif | |
2150 | ||
fe44d621 PZ |
2151 | rq->clock_task += delta; |
2152 | ||
095c0aa8 GC |
2153 | #if defined(CONFIG_IRQ_TIME_ACCOUNTING) || defined(CONFIG_PARAVIRT_TIME_ACCOUNTING) |
2154 | if ((irq_delta + steal) && sched_feat(NONTASK_POWER)) | |
2155 | sched_rt_avg_update(rq, irq_delta + steal); | |
2156 | #endif | |
aa483808 VP |
2157 | } |
2158 | ||
095c0aa8 | 2159 | #ifdef CONFIG_IRQ_TIME_ACCOUNTING |
abb74cef VP |
2160 | static int irqtime_account_hi_update(void) |
2161 | { | |
2162 | struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat; | |
2163 | unsigned long flags; | |
2164 | u64 latest_ns; | |
2165 | int ret = 0; | |
2166 | ||
2167 | local_irq_save(flags); | |
2168 | latest_ns = this_cpu_read(cpu_hardirq_time); | |
64861634 | 2169 | if (nsecs_to_cputime64(latest_ns) > cpustat->irq) |
abb74cef VP |
2170 | ret = 1; |
2171 | local_irq_restore(flags); | |
2172 | return ret; | |
2173 | } | |
2174 | ||
2175 | static int irqtime_account_si_update(void) | |
2176 | { | |
2177 | struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat; | |
2178 | unsigned long flags; | |
2179 | u64 latest_ns; | |
2180 | int ret = 0; | |
2181 | ||
2182 | local_irq_save(flags); | |
2183 | latest_ns = this_cpu_read(cpu_softirq_time); | |
64861634 | 2184 | if (nsecs_to_cputime64(latest_ns) > cpustat->softirq) |
abb74cef VP |
2185 | ret = 1; |
2186 | local_irq_restore(flags); | |
2187 | return ret; | |
2188 | } | |
2189 | ||
fe44d621 | 2190 | #else /* CONFIG_IRQ_TIME_ACCOUNTING */ |
305e6835 | 2191 | |
abb74cef VP |
2192 | #define sched_clock_irqtime (0) |
2193 | ||
095c0aa8 | 2194 | #endif |
b52bfee4 | 2195 | |
1e3c88bd PZ |
2196 | #include "sched_idletask.c" |
2197 | #include "sched_fair.c" | |
2198 | #include "sched_rt.c" | |
5091faa4 | 2199 | #include "sched_autogroup.c" |
34f971f6 | 2200 | #include "sched_stoptask.c" |
1e3c88bd PZ |
2201 | #ifdef CONFIG_SCHED_DEBUG |
2202 | # include "sched_debug.c" | |
2203 | #endif | |
2204 | ||
34f971f6 PZ |
2205 | void sched_set_stop_task(int cpu, struct task_struct *stop) |
2206 | { | |
2207 | struct sched_param param = { .sched_priority = MAX_RT_PRIO - 1 }; | |
2208 | struct task_struct *old_stop = cpu_rq(cpu)->stop; | |
2209 | ||
2210 | if (stop) { | |
2211 | /* | |
2212 | * Make it appear like a SCHED_FIFO task, its something | |
2213 | * userspace knows about and won't get confused about. | |
2214 | * | |
2215 | * Also, it will make PI more or less work without too | |
2216 | * much confusion -- but then, stop work should not | |
2217 | * rely on PI working anyway. | |
2218 | */ | |
2219 | sched_setscheduler_nocheck(stop, SCHED_FIFO, ¶m); | |
2220 | ||
2221 | stop->sched_class = &stop_sched_class; | |
2222 | } | |
2223 | ||
2224 | cpu_rq(cpu)->stop = stop; | |
2225 | ||
2226 | if (old_stop) { | |
2227 | /* | |
2228 | * Reset it back to a normal scheduling class so that | |
2229 | * it can die in pieces. | |
2230 | */ | |
2231 | old_stop->sched_class = &rt_sched_class; | |
2232 | } | |
2233 | } | |
2234 | ||
14531189 | 2235 | /* |
dd41f596 | 2236 | * __normal_prio - return the priority that is based on the static prio |
14531189 | 2237 | */ |
14531189 IM |
2238 | static inline int __normal_prio(struct task_struct *p) |
2239 | { | |
dd41f596 | 2240 | return p->static_prio; |
14531189 IM |
2241 | } |
2242 | ||
b29739f9 IM |
2243 | /* |
2244 | * Calculate the expected normal priority: i.e. priority | |
2245 | * without taking RT-inheritance into account. Might be | |
2246 | * boosted by interactivity modifiers. Changes upon fork, | |
2247 | * setprio syscalls, and whenever the interactivity | |
2248 | * estimator recalculates. | |
2249 | */ | |
36c8b586 | 2250 | static inline int normal_prio(struct task_struct *p) |
b29739f9 IM |
2251 | { |
2252 | int prio; | |
2253 | ||
e05606d3 | 2254 | if (task_has_rt_policy(p)) |
b29739f9 IM |
2255 | prio = MAX_RT_PRIO-1 - p->rt_priority; |
2256 | else | |
2257 | prio = __normal_prio(p); | |
2258 | return prio; | |
2259 | } | |
2260 | ||
2261 | /* | |
2262 | * Calculate the current priority, i.e. the priority | |
2263 | * taken into account by the scheduler. This value might | |
2264 | * be boosted by RT tasks, or might be boosted by | |
2265 | * interactivity modifiers. Will be RT if the task got | |
2266 | * RT-boosted. If not then it returns p->normal_prio. | |
2267 | */ | |
36c8b586 | 2268 | static int effective_prio(struct task_struct *p) |
b29739f9 IM |
2269 | { |
2270 | p->normal_prio = normal_prio(p); | |
2271 | /* | |
2272 | * If we are RT tasks or we were boosted to RT priority, | |
2273 | * keep the priority unchanged. Otherwise, update priority | |
2274 | * to the normal priority: | |
2275 | */ | |
2276 | if (!rt_prio(p->prio)) | |
2277 | return p->normal_prio; | |
2278 | return p->prio; | |
2279 | } | |
2280 | ||
1da177e4 LT |
2281 | /** |
2282 | * task_curr - is this task currently executing on a CPU? | |
2283 | * @p: the task in question. | |
2284 | */ | |
36c8b586 | 2285 | inline int task_curr(const struct task_struct *p) |
1da177e4 LT |
2286 | { |
2287 | return cpu_curr(task_cpu(p)) == p; | |
2288 | } | |
2289 | ||
cb469845 SR |
2290 | static inline void check_class_changed(struct rq *rq, struct task_struct *p, |
2291 | const struct sched_class *prev_class, | |
da7a735e | 2292 | int oldprio) |
cb469845 SR |
2293 | { |
2294 | if (prev_class != p->sched_class) { | |
2295 | if (prev_class->switched_from) | |
da7a735e PZ |
2296 | prev_class->switched_from(rq, p); |
2297 | p->sched_class->switched_to(rq, p); | |
2298 | } else if (oldprio != p->prio) | |
2299 | p->sched_class->prio_changed(rq, p, oldprio); | |
cb469845 SR |
2300 | } |
2301 | ||
1e5a7405 PZ |
2302 | static void check_preempt_curr(struct rq *rq, struct task_struct *p, int flags) |
2303 | { | |
2304 | const struct sched_class *class; | |
2305 | ||
2306 | if (p->sched_class == rq->curr->sched_class) { | |
2307 | rq->curr->sched_class->check_preempt_curr(rq, p, flags); | |
2308 | } else { | |
2309 | for_each_class(class) { | |
2310 | if (class == rq->curr->sched_class) | |
2311 | break; | |
2312 | if (class == p->sched_class) { | |
2313 | resched_task(rq->curr); | |
2314 | break; | |
2315 | } | |
2316 | } | |
2317 | } | |
2318 | ||
2319 | /* | |
2320 | * A queue event has occurred, and we're going to schedule. In | |
2321 | * this case, we can save a useless back to back clock update. | |
2322 | */ | |
fd2f4419 | 2323 | if (rq->curr->on_rq && test_tsk_need_resched(rq->curr)) |
1e5a7405 PZ |
2324 | rq->skip_clock_update = 1; |
2325 | } | |
2326 | ||
1da177e4 | 2327 | #ifdef CONFIG_SMP |
cc367732 IM |
2328 | /* |
2329 | * Is this task likely cache-hot: | |
2330 | */ | |
e7693a36 | 2331 | static int |
cc367732 IM |
2332 | task_hot(struct task_struct *p, u64 now, struct sched_domain *sd) |
2333 | { | |
2334 | s64 delta; | |
2335 | ||
e6c8fba7 PZ |
2336 | if (p->sched_class != &fair_sched_class) |
2337 | return 0; | |
2338 | ||
ef8002f6 NR |
2339 | if (unlikely(p->policy == SCHED_IDLE)) |
2340 | return 0; | |
2341 | ||
f540a608 IM |
2342 | /* |
2343 | * Buddy candidates are cache hot: | |
2344 | */ | |
f685ceac | 2345 | if (sched_feat(CACHE_HOT_BUDDY) && this_rq()->nr_running && |
4793241b PZ |
2346 | (&p->se == cfs_rq_of(&p->se)->next || |
2347 | &p->se == cfs_rq_of(&p->se)->last)) | |
f540a608 IM |
2348 | return 1; |
2349 | ||
6bc1665b IM |
2350 | if (sysctl_sched_migration_cost == -1) |
2351 | return 1; | |
2352 | if (sysctl_sched_migration_cost == 0) | |
2353 | return 0; | |
2354 | ||
cc367732 IM |
2355 | delta = now - p->se.exec_start; |
2356 | ||
2357 | return delta < (s64)sysctl_sched_migration_cost; | |
2358 | } | |
2359 | ||
dd41f596 | 2360 | void set_task_cpu(struct task_struct *p, unsigned int new_cpu) |
c65cc870 | 2361 | { |
e2912009 PZ |
2362 | #ifdef CONFIG_SCHED_DEBUG |
2363 | /* | |
2364 | * We should never call set_task_cpu() on a blocked task, | |
2365 | * ttwu() will sort out the placement. | |
2366 | */ | |
077614ee PZ |
2367 | WARN_ON_ONCE(p->state != TASK_RUNNING && p->state != TASK_WAKING && |
2368 | !(task_thread_info(p)->preempt_count & PREEMPT_ACTIVE)); | |
0122ec5b PZ |
2369 | |
2370 | #ifdef CONFIG_LOCKDEP | |
6c6c54e1 PZ |
2371 | /* |
2372 | * The caller should hold either p->pi_lock or rq->lock, when changing | |
2373 | * a task's CPU. ->pi_lock for waking tasks, rq->lock for runnable tasks. | |
2374 | * | |
2375 | * sched_move_task() holds both and thus holding either pins the cgroup, | |
2376 | * see set_task_rq(). | |
2377 | * | |
2378 | * Furthermore, all task_rq users should acquire both locks, see | |
2379 | * task_rq_lock(). | |
2380 | */ | |
0122ec5b PZ |
2381 | WARN_ON_ONCE(debug_locks && !(lockdep_is_held(&p->pi_lock) || |
2382 | lockdep_is_held(&task_rq(p)->lock))); | |
2383 | #endif | |
e2912009 PZ |
2384 | #endif |
2385 | ||
de1d7286 | 2386 | trace_sched_migrate_task(p, new_cpu); |
cbc34ed1 | 2387 | |
0c69774e PZ |
2388 | if (task_cpu(p) != new_cpu) { |
2389 | p->se.nr_migrations++; | |
a8b0ca17 | 2390 | perf_sw_event(PERF_COUNT_SW_CPU_MIGRATIONS, 1, NULL, 0); |
0c69774e | 2391 | } |
dd41f596 IM |
2392 | |
2393 | __set_task_cpu(p, new_cpu); | |
c65cc870 IM |
2394 | } |
2395 | ||
969c7921 | 2396 | struct migration_arg { |
36c8b586 | 2397 | struct task_struct *task; |
1da177e4 | 2398 | int dest_cpu; |
70b97a7f | 2399 | }; |
1da177e4 | 2400 | |
969c7921 TH |
2401 | static int migration_cpu_stop(void *data); |
2402 | ||
1da177e4 LT |
2403 | /* |
2404 | * wait_task_inactive - wait for a thread to unschedule. | |
2405 | * | |
85ba2d86 RM |
2406 | * If @match_state is nonzero, it's the @p->state value just checked and |
2407 | * not expected to change. If it changes, i.e. @p might have woken up, | |
2408 | * then return zero. When we succeed in waiting for @p to be off its CPU, | |
2409 | * we return a positive number (its total switch count). If a second call | |
2410 | * a short while later returns the same number, the caller can be sure that | |
2411 | * @p has remained unscheduled the whole time. | |
2412 | * | |
1da177e4 LT |
2413 | * The caller must ensure that the task *will* unschedule sometime soon, |
2414 | * else this function might spin for a *long* time. This function can't | |
2415 | * be called with interrupts off, or it may introduce deadlock with | |
2416 | * smp_call_function() if an IPI is sent by the same process we are | |
2417 | * waiting to become inactive. | |
2418 | */ | |
85ba2d86 | 2419 | unsigned long wait_task_inactive(struct task_struct *p, long match_state) |
1da177e4 LT |
2420 | { |
2421 | unsigned long flags; | |
dd41f596 | 2422 | int running, on_rq; |
85ba2d86 | 2423 | unsigned long ncsw; |
70b97a7f | 2424 | struct rq *rq; |
1da177e4 | 2425 | |
3a5c359a AK |
2426 | for (;;) { |
2427 | /* | |
2428 | * We do the initial early heuristics without holding | |
2429 | * any task-queue locks at all. We'll only try to get | |
2430 | * the runqueue lock when things look like they will | |
2431 | * work out! | |
2432 | */ | |
2433 | rq = task_rq(p); | |
fa490cfd | 2434 | |
3a5c359a AK |
2435 | /* |
2436 | * If the task is actively running on another CPU | |
2437 | * still, just relax and busy-wait without holding | |
2438 | * any locks. | |
2439 | * | |
2440 | * NOTE! Since we don't hold any locks, it's not | |
2441 | * even sure that "rq" stays as the right runqueue! | |
2442 | * But we don't care, since "task_running()" will | |
2443 | * return false if the runqueue has changed and p | |
2444 | * is actually now running somewhere else! | |
2445 | */ | |
85ba2d86 RM |
2446 | while (task_running(rq, p)) { |
2447 | if (match_state && unlikely(p->state != match_state)) | |
2448 | return 0; | |
3a5c359a | 2449 | cpu_relax(); |
85ba2d86 | 2450 | } |
fa490cfd | 2451 | |
3a5c359a AK |
2452 | /* |
2453 | * Ok, time to look more closely! We need the rq | |
2454 | * lock now, to be *sure*. If we're wrong, we'll | |
2455 | * just go back and repeat. | |
2456 | */ | |
2457 | rq = task_rq_lock(p, &flags); | |
27a9da65 | 2458 | trace_sched_wait_task(p); |
3a5c359a | 2459 | running = task_running(rq, p); |
fd2f4419 | 2460 | on_rq = p->on_rq; |
85ba2d86 | 2461 | ncsw = 0; |
f31e11d8 | 2462 | if (!match_state || p->state == match_state) |
93dcf55f | 2463 | ncsw = p->nvcsw | LONG_MIN; /* sets MSB */ |
0122ec5b | 2464 | task_rq_unlock(rq, p, &flags); |
fa490cfd | 2465 | |
85ba2d86 RM |
2466 | /* |
2467 | * If it changed from the expected state, bail out now. | |
2468 | */ | |
2469 | if (unlikely(!ncsw)) | |
2470 | break; | |
2471 | ||
3a5c359a AK |
2472 | /* |
2473 | * Was it really running after all now that we | |
2474 | * checked with the proper locks actually held? | |
2475 | * | |
2476 | * Oops. Go back and try again.. | |
2477 | */ | |
2478 | if (unlikely(running)) { | |
2479 | cpu_relax(); | |
2480 | continue; | |
2481 | } | |
fa490cfd | 2482 | |
3a5c359a AK |
2483 | /* |
2484 | * It's not enough that it's not actively running, | |
2485 | * it must be off the runqueue _entirely_, and not | |
2486 | * preempted! | |
2487 | * | |
80dd99b3 | 2488 | * So if it was still runnable (but just not actively |
3a5c359a AK |
2489 | * running right now), it's preempted, and we should |
2490 | * yield - it could be a while. | |
2491 | */ | |
2492 | if (unlikely(on_rq)) { | |
8eb90c30 TG |
2493 | ktime_t to = ktime_set(0, NSEC_PER_SEC/HZ); |
2494 | ||
2495 | set_current_state(TASK_UNINTERRUPTIBLE); | |
2496 | schedule_hrtimeout(&to, HRTIMER_MODE_REL); | |
3a5c359a AK |
2497 | continue; |
2498 | } | |
fa490cfd | 2499 | |
3a5c359a AK |
2500 | /* |
2501 | * Ahh, all good. It wasn't running, and it wasn't | |
2502 | * runnable, which means that it will never become | |
2503 | * running in the future either. We're all done! | |
2504 | */ | |
2505 | break; | |
2506 | } | |
85ba2d86 RM |
2507 | |
2508 | return ncsw; | |
1da177e4 LT |
2509 | } |
2510 | ||
2511 | /*** | |
2512 | * kick_process - kick a running thread to enter/exit the kernel | |
2513 | * @p: the to-be-kicked thread | |
2514 | * | |
2515 | * Cause a process which is running on another CPU to enter | |
2516 | * kernel-mode, without any delay. (to get signals handled.) | |
2517 | * | |
25985edc | 2518 | * NOTE: this function doesn't have to take the runqueue lock, |
1da177e4 LT |
2519 | * because all it wants to ensure is that the remote task enters |
2520 | * the kernel. If the IPI races and the task has been migrated | |
2521 | * to another CPU then no harm is done and the purpose has been | |
2522 | * achieved as well. | |
2523 | */ | |
36c8b586 | 2524 | void kick_process(struct task_struct *p) |
1da177e4 LT |
2525 | { |
2526 | int cpu; | |
2527 | ||
2528 | preempt_disable(); | |
2529 | cpu = task_cpu(p); | |
2530 | if ((cpu != smp_processor_id()) && task_curr(p)) | |
2531 | smp_send_reschedule(cpu); | |
2532 | preempt_enable(); | |
2533 | } | |
b43e3521 | 2534 | EXPORT_SYMBOL_GPL(kick_process); |
476d139c | 2535 | #endif /* CONFIG_SMP */ |
1da177e4 | 2536 | |
970b13ba | 2537 | #ifdef CONFIG_SMP |
30da688e | 2538 | /* |
013fdb80 | 2539 | * ->cpus_allowed is protected by both rq->lock and p->pi_lock |
30da688e | 2540 | */ |
5da9a0fb PZ |
2541 | static int select_fallback_rq(int cpu, struct task_struct *p) |
2542 | { | |
2543 | int dest_cpu; | |
2544 | const struct cpumask *nodemask = cpumask_of_node(cpu_to_node(cpu)); | |
2545 | ||
2546 | /* Look for allowed, online CPU in same node. */ | |
2547 | for_each_cpu_and(dest_cpu, nodemask, cpu_active_mask) | |
fa17b507 | 2548 | if (cpumask_test_cpu(dest_cpu, tsk_cpus_allowed(p))) |
5da9a0fb PZ |
2549 | return dest_cpu; |
2550 | ||
2551 | /* Any allowed, online CPU? */ | |
fa17b507 | 2552 | dest_cpu = cpumask_any_and(tsk_cpus_allowed(p), cpu_active_mask); |
5da9a0fb PZ |
2553 | if (dest_cpu < nr_cpu_ids) |
2554 | return dest_cpu; | |
2555 | ||
2556 | /* No more Mr. Nice Guy. */ | |
48c5ccae PZ |
2557 | dest_cpu = cpuset_cpus_allowed_fallback(p); |
2558 | /* | |
2559 | * Don't tell them about moving exiting tasks or | |
2560 | * kernel threads (both mm NULL), since they never | |
2561 | * leave kernel. | |
2562 | */ | |
2563 | if (p->mm && printk_ratelimit()) { | |
2564 | printk(KERN_INFO "process %d (%s) no longer affine to cpu%d\n", | |
2565 | task_pid_nr(p), p->comm, cpu); | |
5da9a0fb PZ |
2566 | } |
2567 | ||
2568 | return dest_cpu; | |
2569 | } | |
2570 | ||
e2912009 | 2571 | /* |
013fdb80 | 2572 | * The caller (fork, wakeup) owns p->pi_lock, ->cpus_allowed is stable. |
e2912009 | 2573 | */ |
970b13ba | 2574 | static inline |
7608dec2 | 2575 | int select_task_rq(struct task_struct *p, int sd_flags, int wake_flags) |
970b13ba | 2576 | { |
7608dec2 | 2577 | int cpu = p->sched_class->select_task_rq(p, sd_flags, wake_flags); |
e2912009 PZ |
2578 | |
2579 | /* | |
2580 | * In order not to call set_task_cpu() on a blocking task we need | |
2581 | * to rely on ttwu() to place the task on a valid ->cpus_allowed | |
2582 | * cpu. | |
2583 | * | |
2584 | * Since this is common to all placement strategies, this lives here. | |
2585 | * | |
2586 | * [ this allows ->select_task() to simply return task_cpu(p) and | |
2587 | * not worry about this generic constraint ] | |
2588 | */ | |
fa17b507 | 2589 | if (unlikely(!cpumask_test_cpu(cpu, tsk_cpus_allowed(p)) || |
70f11205 | 2590 | !cpu_online(cpu))) |
5da9a0fb | 2591 | cpu = select_fallback_rq(task_cpu(p), p); |
e2912009 PZ |
2592 | |
2593 | return cpu; | |
970b13ba | 2594 | } |
09a40af5 MG |
2595 | |
2596 | static void update_avg(u64 *avg, u64 sample) | |
2597 | { | |
2598 | s64 diff = sample - *avg; | |
2599 | *avg += diff >> 3; | |
2600 | } | |
970b13ba PZ |
2601 | #endif |
2602 | ||
d7c01d27 | 2603 | static void |
b84cb5df | 2604 | ttwu_stat(struct task_struct *p, int cpu, int wake_flags) |
9ed3811a | 2605 | { |
d7c01d27 | 2606 | #ifdef CONFIG_SCHEDSTATS |
b84cb5df PZ |
2607 | struct rq *rq = this_rq(); |
2608 | ||
d7c01d27 PZ |
2609 | #ifdef CONFIG_SMP |
2610 | int this_cpu = smp_processor_id(); | |
2611 | ||
2612 | if (cpu == this_cpu) { | |
2613 | schedstat_inc(rq, ttwu_local); | |
2614 | schedstat_inc(p, se.statistics.nr_wakeups_local); | |
2615 | } else { | |
2616 | struct sched_domain *sd; | |
2617 | ||
2618 | schedstat_inc(p, se.statistics.nr_wakeups_remote); | |
057f3fad | 2619 | rcu_read_lock(); |
d7c01d27 PZ |
2620 | for_each_domain(this_cpu, sd) { |
2621 | if (cpumask_test_cpu(cpu, sched_domain_span(sd))) { | |
2622 | schedstat_inc(sd, ttwu_wake_remote); | |
2623 | break; | |
2624 | } | |
2625 | } | |
057f3fad | 2626 | rcu_read_unlock(); |
d7c01d27 | 2627 | } |
f339b9dc PZ |
2628 | |
2629 | if (wake_flags & WF_MIGRATED) | |
2630 | schedstat_inc(p, se.statistics.nr_wakeups_migrate); | |
2631 | ||
d7c01d27 PZ |
2632 | #endif /* CONFIG_SMP */ |
2633 | ||
2634 | schedstat_inc(rq, ttwu_count); | |
9ed3811a | 2635 | schedstat_inc(p, se.statistics.nr_wakeups); |
d7c01d27 PZ |
2636 | |
2637 | if (wake_flags & WF_SYNC) | |
9ed3811a | 2638 | schedstat_inc(p, se.statistics.nr_wakeups_sync); |
d7c01d27 | 2639 | |
d7c01d27 PZ |
2640 | #endif /* CONFIG_SCHEDSTATS */ |
2641 | } | |
2642 | ||
2643 | static void ttwu_activate(struct rq *rq, struct task_struct *p, int en_flags) | |
2644 | { | |
9ed3811a | 2645 | activate_task(rq, p, en_flags); |
fd2f4419 | 2646 | p->on_rq = 1; |
c2f7115e PZ |
2647 | |
2648 | /* if a worker is waking up, notify workqueue */ | |
2649 | if (p->flags & PF_WQ_WORKER) | |
2650 | wq_worker_waking_up(p, cpu_of(rq)); | |
9ed3811a TH |
2651 | } |
2652 | ||
23f41eeb PZ |
2653 | /* |
2654 | * Mark the task runnable and perform wakeup-preemption. | |
2655 | */ | |
89363381 | 2656 | static void |
23f41eeb | 2657 | ttwu_do_wakeup(struct rq *rq, struct task_struct *p, int wake_flags) |
9ed3811a | 2658 | { |
89363381 | 2659 | trace_sched_wakeup(p, true); |
9ed3811a TH |
2660 | check_preempt_curr(rq, p, wake_flags); |
2661 | ||
2662 | p->state = TASK_RUNNING; | |
2663 | #ifdef CONFIG_SMP | |
2664 | if (p->sched_class->task_woken) | |
2665 | p->sched_class->task_woken(rq, p); | |
2666 | ||
e69c6341 | 2667 | if (rq->idle_stamp) { |
9ed3811a TH |
2668 | u64 delta = rq->clock - rq->idle_stamp; |
2669 | u64 max = 2*sysctl_sched_migration_cost; | |
2670 | ||
2671 | if (delta > max) | |
2672 | rq->avg_idle = max; | |
2673 | else | |
2674 | update_avg(&rq->avg_idle, delta); | |
2675 | rq->idle_stamp = 0; | |
2676 | } | |
2677 | #endif | |
2678 | } | |
2679 | ||
c05fbafb PZ |
2680 | static void |
2681 | ttwu_do_activate(struct rq *rq, struct task_struct *p, int wake_flags) | |
2682 | { | |
2683 | #ifdef CONFIG_SMP | |
2684 | if (p->sched_contributes_to_load) | |
2685 | rq->nr_uninterruptible--; | |
2686 | #endif | |
2687 | ||
2688 | ttwu_activate(rq, p, ENQUEUE_WAKEUP | ENQUEUE_WAKING); | |
2689 | ttwu_do_wakeup(rq, p, wake_flags); | |
2690 | } | |
2691 | ||
2692 | /* | |
2693 | * Called in case the task @p isn't fully descheduled from its runqueue, | |
2694 | * in this case we must do a remote wakeup. Its a 'light' wakeup though, | |
2695 | * since all we need to do is flip p->state to TASK_RUNNING, since | |
2696 | * the task is still ->on_rq. | |
2697 | */ | |
2698 | static int ttwu_remote(struct task_struct *p, int wake_flags) | |
2699 | { | |
2700 | struct rq *rq; | |
2701 | int ret = 0; | |
2702 | ||
2703 | rq = __task_rq_lock(p); | |
2704 | if (p->on_rq) { | |
2705 | ttwu_do_wakeup(rq, p, wake_flags); | |
2706 | ret = 1; | |
2707 | } | |
2708 | __task_rq_unlock(rq); | |
2709 | ||
2710 | return ret; | |
2711 | } | |
2712 | ||
317f3941 | 2713 | #ifdef CONFIG_SMP |
fa14ff4a | 2714 | static void sched_ttwu_pending(void) |
317f3941 PZ |
2715 | { |
2716 | struct rq *rq = this_rq(); | |
fa14ff4a PZ |
2717 | struct llist_node *llist = llist_del_all(&rq->wake_list); |
2718 | struct task_struct *p; | |
317f3941 PZ |
2719 | |
2720 | raw_spin_lock(&rq->lock); | |
2721 | ||
fa14ff4a PZ |
2722 | while (llist) { |
2723 | p = llist_entry(llist, struct task_struct, wake_entry); | |
2724 | llist = llist_next(llist); | |
317f3941 PZ |
2725 | ttwu_do_activate(rq, p, 0); |
2726 | } | |
2727 | ||
2728 | raw_spin_unlock(&rq->lock); | |
2729 | } | |
2730 | ||
2731 | void scheduler_ipi(void) | |
2732 | { | |
ca38062e | 2733 | if (llist_empty(&this_rq()->wake_list) && !got_nohz_idle_kick()) |
c5d753a5 PZ |
2734 | return; |
2735 | ||
2736 | /* | |
2737 | * Not all reschedule IPI handlers call irq_enter/irq_exit, since | |
2738 | * traditionally all their work was done from the interrupt return | |
2739 | * path. Now that we actually do some work, we need to make sure | |
2740 | * we do call them. | |
2741 | * | |
2742 | * Some archs already do call them, luckily irq_enter/exit nest | |
2743 | * properly. | |
2744 | * | |
2745 | * Arguably we should visit all archs and update all handlers, | |
2746 | * however a fair share of IPIs are still resched only so this would | |
2747 | * somewhat pessimize the simple resched case. | |
2748 | */ | |
2749 | irq_enter(); | |
fa14ff4a | 2750 | sched_ttwu_pending(); |
ca38062e SS |
2751 | |
2752 | /* | |
2753 | * Check if someone kicked us for doing the nohz idle load balance. | |
2754 | */ | |
6eb57e0d SS |
2755 | if (unlikely(got_nohz_idle_kick() && !need_resched())) { |
2756 | this_rq()->idle_balance = 1; | |
ca38062e | 2757 | raise_softirq_irqoff(SCHED_SOFTIRQ); |
6eb57e0d | 2758 | } |
c5d753a5 | 2759 | irq_exit(); |
317f3941 PZ |
2760 | } |
2761 | ||
2762 | static void ttwu_queue_remote(struct task_struct *p, int cpu) | |
2763 | { | |
fa14ff4a | 2764 | if (llist_add(&p->wake_entry, &cpu_rq(cpu)->wake_list)) |
317f3941 PZ |
2765 | smp_send_reschedule(cpu); |
2766 | } | |
d6aa8f85 PZ |
2767 | |
2768 | #ifdef __ARCH_WANT_INTERRUPTS_ON_CTXSW | |
2769 | static int ttwu_activate_remote(struct task_struct *p, int wake_flags) | |
2770 | { | |
2771 | struct rq *rq; | |
2772 | int ret = 0; | |
2773 | ||
2774 | rq = __task_rq_lock(p); | |
2775 | if (p->on_cpu) { | |
2776 | ttwu_activate(rq, p, ENQUEUE_WAKEUP); | |
2777 | ttwu_do_wakeup(rq, p, wake_flags); | |
2778 | ret = 1; | |
2779 | } | |
2780 | __task_rq_unlock(rq); | |
2781 | ||
2782 | return ret; | |
2783 | ||
2784 | } | |
2785 | #endif /* __ARCH_WANT_INTERRUPTS_ON_CTXSW */ | |
2786 | #endif /* CONFIG_SMP */ | |
317f3941 | 2787 | |
c05fbafb PZ |
2788 | static void ttwu_queue(struct task_struct *p, int cpu) |
2789 | { | |
2790 | struct rq *rq = cpu_rq(cpu); | |
2791 | ||
17d9f311 | 2792 | #if defined(CONFIG_SMP) |
317f3941 | 2793 | if (sched_feat(TTWU_QUEUE) && cpu != smp_processor_id()) { |
f01114cb | 2794 | sched_clock_cpu(cpu); /* sync clocks x-cpu */ |
317f3941 PZ |
2795 | ttwu_queue_remote(p, cpu); |
2796 | return; | |
2797 | } | |
2798 | #endif | |
2799 | ||
c05fbafb PZ |
2800 | raw_spin_lock(&rq->lock); |
2801 | ttwu_do_activate(rq, p, 0); | |
2802 | raw_spin_unlock(&rq->lock); | |
9ed3811a TH |
2803 | } |
2804 | ||
2805 | /** | |
1da177e4 | 2806 | * try_to_wake_up - wake up a thread |
9ed3811a | 2807 | * @p: the thread to be awakened |
1da177e4 | 2808 | * @state: the mask of task states that can be woken |
9ed3811a | 2809 | * @wake_flags: wake modifier flags (WF_*) |
1da177e4 LT |
2810 | * |
2811 | * Put it on the run-queue if it's not already there. The "current" | |
2812 | * thread is always on the run-queue (except when the actual | |
2813 | * re-schedule is in progress), and as such you're allowed to do | |
2814 | * the simpler "current->state = TASK_RUNNING" to mark yourself | |
2815 | * runnable without the overhead of this. | |
2816 | * | |
9ed3811a TH |
2817 | * Returns %true if @p was woken up, %false if it was already running |
2818 | * or @state didn't match @p's state. | |
1da177e4 | 2819 | */ |
e4a52bcb PZ |
2820 | static int |
2821 | try_to_wake_up(struct task_struct *p, unsigned int state, int wake_flags) | |
1da177e4 | 2822 | { |
1da177e4 | 2823 | unsigned long flags; |
c05fbafb | 2824 | int cpu, success = 0; |
2398f2c6 | 2825 | |
04e2f174 | 2826 | smp_wmb(); |
013fdb80 | 2827 | raw_spin_lock_irqsave(&p->pi_lock, flags); |
e9c84311 | 2828 | if (!(p->state & state)) |
1da177e4 LT |
2829 | goto out; |
2830 | ||
c05fbafb | 2831 | success = 1; /* we're going to change ->state */ |
1da177e4 | 2832 | cpu = task_cpu(p); |
1da177e4 | 2833 | |
c05fbafb PZ |
2834 | if (p->on_rq && ttwu_remote(p, wake_flags)) |
2835 | goto stat; | |
1da177e4 | 2836 | |
1da177e4 | 2837 | #ifdef CONFIG_SMP |
e9c84311 | 2838 | /* |
c05fbafb PZ |
2839 | * If the owning (remote) cpu is still in the middle of schedule() with |
2840 | * this task as prev, wait until its done referencing the task. | |
e9c84311 | 2841 | */ |
e4a52bcb PZ |
2842 | while (p->on_cpu) { |
2843 | #ifdef __ARCH_WANT_INTERRUPTS_ON_CTXSW | |
2844 | /* | |
d6aa8f85 PZ |
2845 | * In case the architecture enables interrupts in |
2846 | * context_switch(), we cannot busy wait, since that | |
2847 | * would lead to deadlocks when an interrupt hits and | |
2848 | * tries to wake up @prev. So bail and do a complete | |
2849 | * remote wakeup. | |
e4a52bcb | 2850 | */ |
d6aa8f85 | 2851 | if (ttwu_activate_remote(p, wake_flags)) |
c05fbafb | 2852 | goto stat; |
d6aa8f85 | 2853 | #else |
e4a52bcb | 2854 | cpu_relax(); |
d6aa8f85 | 2855 | #endif |
371fd7e7 | 2856 | } |
0970d299 | 2857 | /* |
e4a52bcb | 2858 | * Pairs with the smp_wmb() in finish_lock_switch(). |
0970d299 | 2859 | */ |
e4a52bcb | 2860 | smp_rmb(); |
1da177e4 | 2861 | |
a8e4f2ea | 2862 | p->sched_contributes_to_load = !!task_contributes_to_load(p); |
e9c84311 | 2863 | p->state = TASK_WAKING; |
e7693a36 | 2864 | |
e4a52bcb | 2865 | if (p->sched_class->task_waking) |
74f8e4b2 | 2866 | p->sched_class->task_waking(p); |
efbbd05a | 2867 | |
7608dec2 | 2868 | cpu = select_task_rq(p, SD_BALANCE_WAKE, wake_flags); |
f339b9dc PZ |
2869 | if (task_cpu(p) != cpu) { |
2870 | wake_flags |= WF_MIGRATED; | |
e4a52bcb | 2871 | set_task_cpu(p, cpu); |
f339b9dc | 2872 | } |
1da177e4 | 2873 | #endif /* CONFIG_SMP */ |
1da177e4 | 2874 | |
c05fbafb PZ |
2875 | ttwu_queue(p, cpu); |
2876 | stat: | |
b84cb5df | 2877 | ttwu_stat(p, cpu, wake_flags); |
1da177e4 | 2878 | out: |
013fdb80 | 2879 | raw_spin_unlock_irqrestore(&p->pi_lock, flags); |
1da177e4 LT |
2880 | |
2881 | return success; | |
2882 | } | |
2883 | ||
21aa9af0 TH |
2884 | /** |
2885 | * try_to_wake_up_local - try to wake up a local task with rq lock held | |
2886 | * @p: the thread to be awakened | |
2887 | * | |
2acca55e | 2888 | * Put @p on the run-queue if it's not already there. The caller must |
21aa9af0 | 2889 | * ensure that this_rq() is locked, @p is bound to this_rq() and not |
2acca55e | 2890 | * the current task. |
21aa9af0 TH |
2891 | */ |
2892 | static void try_to_wake_up_local(struct task_struct *p) | |
2893 | { | |
2894 | struct rq *rq = task_rq(p); | |
21aa9af0 TH |
2895 | |
2896 | BUG_ON(rq != this_rq()); | |
2897 | BUG_ON(p == current); | |
2898 | lockdep_assert_held(&rq->lock); | |
2899 | ||
2acca55e PZ |
2900 | if (!raw_spin_trylock(&p->pi_lock)) { |
2901 | raw_spin_unlock(&rq->lock); | |
2902 | raw_spin_lock(&p->pi_lock); | |
2903 | raw_spin_lock(&rq->lock); | |
2904 | } | |
2905 | ||
21aa9af0 | 2906 | if (!(p->state & TASK_NORMAL)) |
2acca55e | 2907 | goto out; |
21aa9af0 | 2908 | |
fd2f4419 | 2909 | if (!p->on_rq) |
d7c01d27 PZ |
2910 | ttwu_activate(rq, p, ENQUEUE_WAKEUP); |
2911 | ||
23f41eeb | 2912 | ttwu_do_wakeup(rq, p, 0); |
b84cb5df | 2913 | ttwu_stat(p, smp_processor_id(), 0); |
2acca55e PZ |
2914 | out: |
2915 | raw_spin_unlock(&p->pi_lock); | |
21aa9af0 TH |
2916 | } |
2917 | ||
50fa610a DH |
2918 | /** |
2919 | * wake_up_process - Wake up a specific process | |
2920 | * @p: The process to be woken up. | |
2921 | * | |
2922 | * Attempt to wake up the nominated process and move it to the set of runnable | |
2923 | * processes. Returns 1 if the process was woken up, 0 if it was already | |
2924 | * running. | |
2925 | * | |
2926 | * It may be assumed that this function implies a write memory barrier before | |
2927 | * changing the task state if and only if any tasks are woken up. | |
2928 | */ | |
7ad5b3a5 | 2929 | int wake_up_process(struct task_struct *p) |
1da177e4 | 2930 | { |
d9514f6c | 2931 | return try_to_wake_up(p, TASK_ALL, 0); |
1da177e4 | 2932 | } |
1da177e4 LT |
2933 | EXPORT_SYMBOL(wake_up_process); |
2934 | ||
7ad5b3a5 | 2935 | int wake_up_state(struct task_struct *p, unsigned int state) |
1da177e4 LT |
2936 | { |
2937 | return try_to_wake_up(p, state, 0); | |
2938 | } | |
2939 | ||
1da177e4 LT |
2940 | /* |
2941 | * Perform scheduler related setup for a newly forked process p. | |
2942 | * p is forked by current. | |
dd41f596 IM |
2943 | * |
2944 | * __sched_fork() is basic setup used by init_idle() too: | |
2945 | */ | |
2946 | static void __sched_fork(struct task_struct *p) | |
2947 | { | |
fd2f4419 PZ |
2948 | p->on_rq = 0; |
2949 | ||
2950 | p->se.on_rq = 0; | |
dd41f596 IM |
2951 | p->se.exec_start = 0; |
2952 | p->se.sum_exec_runtime = 0; | |
f6cf891c | 2953 | p->se.prev_sum_exec_runtime = 0; |
6c594c21 | 2954 | p->se.nr_migrations = 0; |
da7a735e | 2955 | p->se.vruntime = 0; |
fd2f4419 | 2956 | INIT_LIST_HEAD(&p->se.group_node); |
6cfb0d5d IM |
2957 | |
2958 | #ifdef CONFIG_SCHEDSTATS | |
41acab88 | 2959 | memset(&p->se.statistics, 0, sizeof(p->se.statistics)); |
6cfb0d5d | 2960 | #endif |
476d139c | 2961 | |
fa717060 | 2962 | INIT_LIST_HEAD(&p->rt.run_list); |
476d139c | 2963 | |
e107be36 AK |
2964 | #ifdef CONFIG_PREEMPT_NOTIFIERS |
2965 | INIT_HLIST_HEAD(&p->preempt_notifiers); | |
2966 | #endif | |
dd41f596 IM |
2967 | } |
2968 | ||
2969 | /* | |
2970 | * fork()/clone()-time setup: | |
2971 | */ | |
3e51e3ed | 2972 | void sched_fork(struct task_struct *p) |
dd41f596 | 2973 | { |
0122ec5b | 2974 | unsigned long flags; |
dd41f596 IM |
2975 | int cpu = get_cpu(); |
2976 | ||
2977 | __sched_fork(p); | |
06b83b5f | 2978 | /* |
0017d735 | 2979 | * We mark the process as running here. This guarantees that |
06b83b5f PZ |
2980 | * nobody will actually run it, and a signal or other external |
2981 | * event cannot wake it up and insert it on the runqueue either. | |
2982 | */ | |
0017d735 | 2983 | p->state = TASK_RUNNING; |
dd41f596 | 2984 | |
c350a04e MG |
2985 | /* |
2986 | * Make sure we do not leak PI boosting priority to the child. | |
2987 | */ | |
2988 | p->prio = current->normal_prio; | |
2989 | ||
b9dc29e7 MG |
2990 | /* |
2991 | * Revert to default priority/policy on fork if requested. | |
2992 | */ | |
2993 | if (unlikely(p->sched_reset_on_fork)) { | |
c350a04e | 2994 | if (task_has_rt_policy(p)) { |
b9dc29e7 | 2995 | p->policy = SCHED_NORMAL; |
6c697bdf | 2996 | p->static_prio = NICE_TO_PRIO(0); |
c350a04e MG |
2997 | p->rt_priority = 0; |
2998 | } else if (PRIO_TO_NICE(p->static_prio) < 0) | |
2999 | p->static_prio = NICE_TO_PRIO(0); | |
3000 | ||
3001 | p->prio = p->normal_prio = __normal_prio(p); | |
3002 | set_load_weight(p); | |
6c697bdf | 3003 | |
b9dc29e7 MG |
3004 | /* |
3005 | * We don't need the reset flag anymore after the fork. It has | |
3006 | * fulfilled its duty: | |
3007 | */ | |
3008 | p->sched_reset_on_fork = 0; | |
3009 | } | |
ca94c442 | 3010 | |
2ddbf952 HS |
3011 | if (!rt_prio(p->prio)) |
3012 | p->sched_class = &fair_sched_class; | |
b29739f9 | 3013 | |
cd29fe6f PZ |
3014 | if (p->sched_class->task_fork) |
3015 | p->sched_class->task_fork(p); | |
3016 | ||
86951599 PZ |
3017 | /* |
3018 | * The child is not yet in the pid-hash so no cgroup attach races, | |
3019 | * and the cgroup is pinned to this child due to cgroup_fork() | |
3020 | * is ran before sched_fork(). | |
3021 | * | |
3022 | * Silence PROVE_RCU. | |
3023 | */ | |
0122ec5b | 3024 | raw_spin_lock_irqsave(&p->pi_lock, flags); |
5f3edc1b | 3025 | set_task_cpu(p, cpu); |
0122ec5b | 3026 | raw_spin_unlock_irqrestore(&p->pi_lock, flags); |
5f3edc1b | 3027 | |
52f17b6c | 3028 | #if defined(CONFIG_SCHEDSTATS) || defined(CONFIG_TASK_DELAY_ACCT) |
dd41f596 | 3029 | if (likely(sched_info_on())) |
52f17b6c | 3030 | memset(&p->sched_info, 0, sizeof(p->sched_info)); |
1da177e4 | 3031 | #endif |
3ca7a440 PZ |
3032 | #if defined(CONFIG_SMP) |
3033 | p->on_cpu = 0; | |
4866cde0 | 3034 | #endif |
bdd4e85d | 3035 | #ifdef CONFIG_PREEMPT_COUNT |
4866cde0 | 3036 | /* Want to start with kernel preemption disabled. */ |
a1261f54 | 3037 | task_thread_info(p)->preempt_count = 1; |
1da177e4 | 3038 | #endif |
806c09a7 | 3039 | #ifdef CONFIG_SMP |
917b627d | 3040 | plist_node_init(&p->pushable_tasks, MAX_PRIO); |
806c09a7 | 3041 | #endif |
917b627d | 3042 | |
476d139c | 3043 | put_cpu(); |
1da177e4 LT |
3044 | } |
3045 | ||
3046 | /* | |
3047 | * wake_up_new_task - wake up a newly created task for the first time. | |
3048 | * | |
3049 | * This function will do some initial scheduler statistics housekeeping | |
3050 | * that must be done for every newly created context, then puts the task | |
3051 | * on the runqueue and wakes it. | |
3052 | */ | |
3e51e3ed | 3053 | void wake_up_new_task(struct task_struct *p) |
1da177e4 LT |
3054 | { |
3055 | unsigned long flags; | |
dd41f596 | 3056 | struct rq *rq; |
fabf318e | 3057 | |
ab2515c4 | 3058 | raw_spin_lock_irqsave(&p->pi_lock, flags); |
fabf318e PZ |
3059 | #ifdef CONFIG_SMP |
3060 | /* | |
3061 | * Fork balancing, do it here and not earlier because: | |
3062 | * - cpus_allowed can change in the fork path | |
3063 | * - any previously selected cpu might disappear through hotplug | |
fabf318e | 3064 | */ |
ab2515c4 | 3065 | set_task_cpu(p, select_task_rq(p, SD_BALANCE_FORK, 0)); |
0017d735 PZ |
3066 | #endif |
3067 | ||
ab2515c4 | 3068 | rq = __task_rq_lock(p); |
cd29fe6f | 3069 | activate_task(rq, p, 0); |
fd2f4419 | 3070 | p->on_rq = 1; |
89363381 | 3071 | trace_sched_wakeup_new(p, true); |
a7558e01 | 3072 | check_preempt_curr(rq, p, WF_FORK); |
9a897c5a | 3073 | #ifdef CONFIG_SMP |
efbbd05a PZ |
3074 | if (p->sched_class->task_woken) |
3075 | p->sched_class->task_woken(rq, p); | |
9a897c5a | 3076 | #endif |
0122ec5b | 3077 | task_rq_unlock(rq, p, &flags); |
1da177e4 LT |
3078 | } |
3079 | ||
e107be36 AK |
3080 | #ifdef CONFIG_PREEMPT_NOTIFIERS |
3081 | ||
3082 | /** | |
80dd99b3 | 3083 | * preempt_notifier_register - tell me when current is being preempted & rescheduled |
421cee29 | 3084 | * @notifier: notifier struct to register |
e107be36 AK |
3085 | */ |
3086 | void preempt_notifier_register(struct preempt_notifier *notifier) | |
3087 | { | |
3088 | hlist_add_head(¬ifier->link, ¤t->preempt_notifiers); | |
3089 | } | |
3090 | EXPORT_SYMBOL_GPL(preempt_notifier_register); | |
3091 | ||
3092 | /** | |
3093 | * preempt_notifier_unregister - no longer interested in preemption notifications | |
421cee29 | 3094 | * @notifier: notifier struct to unregister |
e107be36 AK |
3095 | * |
3096 | * This is safe to call from within a preemption notifier. | |
3097 | */ | |
3098 | void preempt_notifier_unregister(struct preempt_notifier *notifier) | |
3099 | { | |
3100 | hlist_del(¬ifier->link); | |
3101 | } | |
3102 | EXPORT_SYMBOL_GPL(preempt_notifier_unregister); | |
3103 | ||
3104 | static void fire_sched_in_preempt_notifiers(struct task_struct *curr) | |
3105 | { | |
3106 | struct preempt_notifier *notifier; | |
3107 | struct hlist_node *node; | |
3108 | ||
3109 | hlist_for_each_entry(notifier, node, &curr->preempt_notifiers, link) | |
3110 | notifier->ops->sched_in(notifier, raw_smp_processor_id()); | |
3111 | } | |
3112 | ||
3113 | static void | |
3114 | fire_sched_out_preempt_notifiers(struct task_struct *curr, | |
3115 | struct task_struct *next) | |
3116 | { | |
3117 | struct preempt_notifier *notifier; | |
3118 | struct hlist_node *node; | |
3119 | ||
3120 | hlist_for_each_entry(notifier, node, &curr->preempt_notifiers, link) | |
3121 | notifier->ops->sched_out(notifier, next); | |
3122 | } | |
3123 | ||
6d6bc0ad | 3124 | #else /* !CONFIG_PREEMPT_NOTIFIERS */ |
e107be36 AK |
3125 | |
3126 | static void fire_sched_in_preempt_notifiers(struct task_struct *curr) | |
3127 | { | |
3128 | } | |
3129 | ||
3130 | static void | |
3131 | fire_sched_out_preempt_notifiers(struct task_struct *curr, | |
3132 | struct task_struct *next) | |
3133 | { | |
3134 | } | |
3135 | ||
6d6bc0ad | 3136 | #endif /* CONFIG_PREEMPT_NOTIFIERS */ |
e107be36 | 3137 | |
4866cde0 NP |
3138 | /** |
3139 | * prepare_task_switch - prepare to switch tasks | |
3140 | * @rq: the runqueue preparing to switch | |
421cee29 | 3141 | * @prev: the current task that is being switched out |
4866cde0 NP |
3142 | * @next: the task we are going to switch to. |
3143 | * | |
3144 | * This is called with the rq lock held and interrupts off. It must | |
3145 | * be paired with a subsequent finish_task_switch after the context | |
3146 | * switch. | |
3147 | * | |
3148 | * prepare_task_switch sets up locking and calls architecture specific | |
3149 | * hooks. | |
3150 | */ | |
e107be36 AK |
3151 | static inline void |
3152 | prepare_task_switch(struct rq *rq, struct task_struct *prev, | |
3153 | struct task_struct *next) | |
4866cde0 | 3154 | { |
fe4b04fa PZ |
3155 | sched_info_switch(prev, next); |
3156 | perf_event_task_sched_out(prev, next); | |
e107be36 | 3157 | fire_sched_out_preempt_notifiers(prev, next); |
4866cde0 NP |
3158 | prepare_lock_switch(rq, next); |
3159 | prepare_arch_switch(next); | |
fe4b04fa | 3160 | trace_sched_switch(prev, next); |
4866cde0 NP |
3161 | } |
3162 | ||
1da177e4 LT |
3163 | /** |
3164 | * finish_task_switch - clean up after a task-switch | |
344babaa | 3165 | * @rq: runqueue associated with task-switch |
1da177e4 LT |
3166 | * @prev: the thread we just switched away from. |
3167 | * | |
4866cde0 NP |
3168 | * finish_task_switch must be called after the context switch, paired |
3169 | * with a prepare_task_switch call before the context switch. | |
3170 | * finish_task_switch will reconcile locking set up by prepare_task_switch, | |
3171 | * and do any other architecture-specific cleanup actions. | |
1da177e4 LT |
3172 | * |
3173 | * Note that we may have delayed dropping an mm in context_switch(). If | |
41a2d6cf | 3174 | * so, we finish that here outside of the runqueue lock. (Doing it |
1da177e4 LT |
3175 | * with the lock held can cause deadlocks; see schedule() for |
3176 | * details.) | |
3177 | */ | |
a9957449 | 3178 | static void finish_task_switch(struct rq *rq, struct task_struct *prev) |
1da177e4 LT |
3179 | __releases(rq->lock) |
3180 | { | |
1da177e4 | 3181 | struct mm_struct *mm = rq->prev_mm; |
55a101f8 | 3182 | long prev_state; |
1da177e4 LT |
3183 | |
3184 | rq->prev_mm = NULL; | |
3185 | ||
3186 | /* | |
3187 | * A task struct has one reference for the use as "current". | |
c394cc9f | 3188 | * If a task dies, then it sets TASK_DEAD in tsk->state and calls |
55a101f8 ON |
3189 | * schedule one last time. The schedule call will never return, and |
3190 | * the scheduled task must drop that reference. | |
c394cc9f | 3191 | * The test for TASK_DEAD must occur while the runqueue locks are |
1da177e4 LT |
3192 | * still held, otherwise prev could be scheduled on another cpu, die |
3193 | * there before we look at prev->state, and then the reference would | |
3194 | * be dropped twice. | |
3195 | * Manfred Spraul <manfred@colorfullife.com> | |
3196 | */ | |
55a101f8 | 3197 | prev_state = prev->state; |
4866cde0 | 3198 | finish_arch_switch(prev); |
8381f65d JI |
3199 | #ifdef __ARCH_WANT_INTERRUPTS_ON_CTXSW |
3200 | local_irq_disable(); | |
3201 | #endif /* __ARCH_WANT_INTERRUPTS_ON_CTXSW */ | |
a8d757ef | 3202 | perf_event_task_sched_in(prev, current); |
8381f65d JI |
3203 | #ifdef __ARCH_WANT_INTERRUPTS_ON_CTXSW |
3204 | local_irq_enable(); | |
3205 | #endif /* __ARCH_WANT_INTERRUPTS_ON_CTXSW */ | |
4866cde0 | 3206 | finish_lock_switch(rq, prev); |
e8fa1362 | 3207 | |
e107be36 | 3208 | fire_sched_in_preempt_notifiers(current); |
1da177e4 LT |
3209 | if (mm) |
3210 | mmdrop(mm); | |
c394cc9f | 3211 | if (unlikely(prev_state == TASK_DEAD)) { |
c6fd91f0 | 3212 | /* |
3213 | * Remove function-return probe instances associated with this | |
3214 | * task and put them back on the free list. | |
9761eea8 | 3215 | */ |
c6fd91f0 | 3216 | kprobe_flush_task(prev); |
1da177e4 | 3217 | put_task_struct(prev); |
c6fd91f0 | 3218 | } |
1da177e4 LT |
3219 | } |
3220 | ||
3f029d3c GH |
3221 | #ifdef CONFIG_SMP |
3222 | ||
3223 | /* assumes rq->lock is held */ | |
3224 | static inline void pre_schedule(struct rq *rq, struct task_struct *prev) | |
3225 | { | |
3226 | if (prev->sched_class->pre_schedule) | |
3227 | prev->sched_class->pre_schedule(rq, prev); | |
3228 | } | |
3229 | ||
3230 | /* rq->lock is NOT held, but preemption is disabled */ | |
3231 | static inline void post_schedule(struct rq *rq) | |
3232 | { | |
3233 | if (rq->post_schedule) { | |
3234 | unsigned long flags; | |
3235 | ||
05fa785c | 3236 | raw_spin_lock_irqsave(&rq->lock, flags); |
3f029d3c GH |
3237 | if (rq->curr->sched_class->post_schedule) |
3238 | rq->curr->sched_class->post_schedule(rq); | |
05fa785c | 3239 | raw_spin_unlock_irqrestore(&rq->lock, flags); |
3f029d3c GH |
3240 | |
3241 | rq->post_schedule = 0; | |
3242 | } | |
3243 | } | |
3244 | ||
3245 | #else | |
da19ab51 | 3246 | |
3f029d3c GH |
3247 | static inline void pre_schedule(struct rq *rq, struct task_struct *p) |
3248 | { | |
3249 | } | |
3250 | ||
3251 | static inline void post_schedule(struct rq *rq) | |
3252 | { | |
1da177e4 LT |
3253 | } |
3254 | ||
3f029d3c GH |
3255 | #endif |
3256 | ||
1da177e4 LT |
3257 | /** |
3258 | * schedule_tail - first thing a freshly forked thread must call. | |
3259 | * @prev: the thread we just switched away from. | |
3260 | */ | |
36c8b586 | 3261 | asmlinkage void schedule_tail(struct task_struct *prev) |
1da177e4 LT |
3262 | __releases(rq->lock) |
3263 | { | |
70b97a7f IM |
3264 | struct rq *rq = this_rq(); |
3265 | ||
4866cde0 | 3266 | finish_task_switch(rq, prev); |
da19ab51 | 3267 | |
3f029d3c GH |
3268 | /* |
3269 | * FIXME: do we need to worry about rq being invalidated by the | |
3270 | * task_switch? | |
3271 | */ | |
3272 | post_schedule(rq); | |
70b97a7f | 3273 | |
4866cde0 NP |
3274 | #ifdef __ARCH_WANT_UNLOCKED_CTXSW |
3275 | /* In this case, finish_task_switch does not reenable preemption */ | |
3276 | preempt_enable(); | |
3277 | #endif | |
1da177e4 | 3278 | if (current->set_child_tid) |
b488893a | 3279 | put_user(task_pid_vnr(current), current->set_child_tid); |
1da177e4 LT |
3280 | } |
3281 | ||
3282 | /* | |
3283 | * context_switch - switch to the new MM and the new | |
3284 | * thread's register state. | |
3285 | */ | |
dd41f596 | 3286 | static inline void |
70b97a7f | 3287 | context_switch(struct rq *rq, struct task_struct *prev, |
36c8b586 | 3288 | struct task_struct *next) |
1da177e4 | 3289 | { |
dd41f596 | 3290 | struct mm_struct *mm, *oldmm; |
1da177e4 | 3291 | |
e107be36 | 3292 | prepare_task_switch(rq, prev, next); |
fe4b04fa | 3293 | |
dd41f596 IM |
3294 | mm = next->mm; |
3295 | oldmm = prev->active_mm; | |
9226d125 ZA |
3296 | /* |
3297 | * For paravirt, this is coupled with an exit in switch_to to | |
3298 | * combine the page table reload and the switch backend into | |
3299 | * one hypercall. | |
3300 | */ | |
224101ed | 3301 | arch_start_context_switch(prev); |
9226d125 | 3302 | |
31915ab4 | 3303 | if (!mm) { |
1da177e4 LT |
3304 | next->active_mm = oldmm; |
3305 | atomic_inc(&oldmm->mm_count); | |
3306 | enter_lazy_tlb(oldmm, next); | |
3307 | } else | |
3308 | switch_mm(oldmm, mm, next); | |
3309 | ||
31915ab4 | 3310 | if (!prev->mm) { |
1da177e4 | 3311 | prev->active_mm = NULL; |
1da177e4 LT |
3312 | rq->prev_mm = oldmm; |
3313 | } | |
3a5f5e48 IM |
3314 | /* |
3315 | * Since the runqueue lock will be released by the next | |
3316 | * task (which is an invalid locking op but in the case | |
3317 | * of the scheduler it's an obvious special-case), so we | |
3318 | * do an early lockdep release here: | |
3319 | */ | |
3320 | #ifndef __ARCH_WANT_UNLOCKED_CTXSW | |
8a25d5de | 3321 | spin_release(&rq->lock.dep_map, 1, _THIS_IP_); |
3a5f5e48 | 3322 | #endif |
1da177e4 LT |
3323 | |
3324 | /* Here we just switch the register state and the stack. */ | |
3325 | switch_to(prev, next, prev); | |
3326 | ||
dd41f596 IM |
3327 | barrier(); |
3328 | /* | |
3329 | * this_rq must be evaluated again because prev may have moved | |
3330 | * CPUs since it called schedule(), thus the 'rq' on its stack | |
3331 | * frame will be invalid. | |
3332 | */ | |
3333 | finish_task_switch(this_rq(), prev); | |
1da177e4 LT |
3334 | } |
3335 | ||
3336 | /* | |
3337 | * nr_running, nr_uninterruptible and nr_context_switches: | |
3338 | * | |
3339 | * externally visible scheduler statistics: current number of runnable | |
3340 | * threads, current number of uninterruptible-sleeping threads, total | |
3341 | * number of context switches performed since bootup. | |
3342 | */ | |
3343 | unsigned long nr_running(void) | |
3344 | { | |
3345 | unsigned long i, sum = 0; | |
3346 | ||
3347 | for_each_online_cpu(i) | |
3348 | sum += cpu_rq(i)->nr_running; | |
3349 | ||
3350 | return sum; | |
f711f609 | 3351 | } |
1da177e4 LT |
3352 | |
3353 | unsigned long nr_uninterruptible(void) | |
f711f609 | 3354 | { |
1da177e4 | 3355 | unsigned long i, sum = 0; |
f711f609 | 3356 | |
0a945022 | 3357 | for_each_possible_cpu(i) |
1da177e4 | 3358 | sum += cpu_rq(i)->nr_uninterruptible; |
f711f609 GS |
3359 | |
3360 | /* | |
1da177e4 LT |
3361 | * Since we read the counters lockless, it might be slightly |
3362 | * inaccurate. Do not allow it to go below zero though: | |
f711f609 | 3363 | */ |
1da177e4 LT |
3364 | if (unlikely((long)sum < 0)) |
3365 | sum = 0; | |
f711f609 | 3366 | |
1da177e4 | 3367 | return sum; |
f711f609 | 3368 | } |
f711f609 | 3369 | |
1da177e4 | 3370 | unsigned long long nr_context_switches(void) |
46cb4b7c | 3371 | { |
cc94abfc SR |
3372 | int i; |
3373 | unsigned long long sum = 0; | |
46cb4b7c | 3374 | |
0a945022 | 3375 | for_each_possible_cpu(i) |
1da177e4 | 3376 | sum += cpu_rq(i)->nr_switches; |
46cb4b7c | 3377 | |
1da177e4 LT |
3378 | return sum; |
3379 | } | |
483b4ee6 | 3380 | |
1da177e4 LT |
3381 | unsigned long nr_iowait(void) |
3382 | { | |
3383 | unsigned long i, sum = 0; | |
483b4ee6 | 3384 | |
0a945022 | 3385 | for_each_possible_cpu(i) |
1da177e4 | 3386 | sum += atomic_read(&cpu_rq(i)->nr_iowait); |
46cb4b7c | 3387 | |
1da177e4 LT |
3388 | return sum; |
3389 | } | |
483b4ee6 | 3390 | |
8c215bd3 | 3391 | unsigned long nr_iowait_cpu(int cpu) |
69d25870 | 3392 | { |
8c215bd3 | 3393 | struct rq *this = cpu_rq(cpu); |
69d25870 AV |
3394 | return atomic_read(&this->nr_iowait); |
3395 | } | |
46cb4b7c | 3396 | |
69d25870 AV |
3397 | unsigned long this_cpu_load(void) |
3398 | { | |
3399 | struct rq *this = this_rq(); | |
3400 | return this->cpu_load[0]; | |
3401 | } | |
e790fb0b | 3402 | |
46cb4b7c | 3403 | |
dce48a84 TG |
3404 | /* Variables and functions for calc_load */ |
3405 | static atomic_long_t calc_load_tasks; | |
3406 | static unsigned long calc_load_update; | |
3407 | unsigned long avenrun[3]; | |
3408 | EXPORT_SYMBOL(avenrun); | |
46cb4b7c | 3409 | |
74f5187a PZ |
3410 | static long calc_load_fold_active(struct rq *this_rq) |
3411 | { | |
3412 | long nr_active, delta = 0; | |
3413 | ||
3414 | nr_active = this_rq->nr_running; | |
3415 | nr_active += (long) this_rq->nr_uninterruptible; | |
3416 | ||
3417 | if (nr_active != this_rq->calc_load_active) { | |
3418 | delta = nr_active - this_rq->calc_load_active; | |
3419 | this_rq->calc_load_active = nr_active; | |
3420 | } | |
3421 | ||
3422 | return delta; | |
3423 | } | |
3424 | ||
0f004f5a PZ |
3425 | static unsigned long |
3426 | calc_load(unsigned long load, unsigned long exp, unsigned long active) | |
3427 | { | |
3428 | load *= exp; | |
3429 | load += active * (FIXED_1 - exp); | |
3430 | load += 1UL << (FSHIFT - 1); | |
3431 | return load >> FSHIFT; | |
3432 | } | |
3433 | ||
74f5187a PZ |
3434 | #ifdef CONFIG_NO_HZ |
3435 | /* | |
3436 | * For NO_HZ we delay the active fold to the next LOAD_FREQ update. | |
3437 | * | |
3438 | * When making the ILB scale, we should try to pull this in as well. | |
3439 | */ | |
3440 | static atomic_long_t calc_load_tasks_idle; | |
3441 | ||
3442 | static void calc_load_account_idle(struct rq *this_rq) | |
3443 | { | |
3444 | long delta; | |
3445 | ||
3446 | delta = calc_load_fold_active(this_rq); | |
3447 | if (delta) | |
3448 | atomic_long_add(delta, &calc_load_tasks_idle); | |
3449 | } | |
3450 | ||
3451 | static long calc_load_fold_idle(void) | |
3452 | { | |
3453 | long delta = 0; | |
3454 | ||
3455 | /* | |
3456 | * Its got a race, we don't care... | |
3457 | */ | |
3458 | if (atomic_long_read(&calc_load_tasks_idle)) | |
3459 | delta = atomic_long_xchg(&calc_load_tasks_idle, 0); | |
3460 | ||
3461 | return delta; | |
3462 | } | |
0f004f5a PZ |
3463 | |
3464 | /** | |
3465 | * fixed_power_int - compute: x^n, in O(log n) time | |
3466 | * | |
3467 | * @x: base of the power | |
3468 | * @frac_bits: fractional bits of @x | |
3469 | * @n: power to raise @x to. | |
3470 | * | |
3471 | * By exploiting the relation between the definition of the natural power | |
3472 | * function: x^n := x*x*...*x (x multiplied by itself for n times), and | |
3473 | * the binary encoding of numbers used by computers: n := \Sum n_i * 2^i, | |
3474 | * (where: n_i \elem {0, 1}, the binary vector representing n), | |
3475 | * we find: x^n := x^(\Sum n_i * 2^i) := \Prod x^(n_i * 2^i), which is | |
3476 | * of course trivially computable in O(log_2 n), the length of our binary | |
3477 | * vector. | |
3478 | */ | |
3479 | static unsigned long | |
3480 | fixed_power_int(unsigned long x, unsigned int frac_bits, unsigned int n) | |
3481 | { | |
3482 | unsigned long result = 1UL << frac_bits; | |
3483 | ||
3484 | if (n) for (;;) { | |
3485 | if (n & 1) { | |
3486 | result *= x; | |
3487 | result += 1UL << (frac_bits - 1); | |
3488 | result >>= frac_bits; | |
3489 | } | |
3490 | n >>= 1; | |
3491 | if (!n) | |
3492 | break; | |
3493 | x *= x; | |
3494 | x += 1UL << (frac_bits - 1); | |
3495 | x >>= frac_bits; | |
3496 | } | |
3497 | ||
3498 | return result; | |
3499 | } | |
3500 | ||
3501 | /* | |
3502 | * a1 = a0 * e + a * (1 - e) | |
3503 | * | |
3504 | * a2 = a1 * e + a * (1 - e) | |
3505 | * = (a0 * e + a * (1 - e)) * e + a * (1 - e) | |
3506 | * = a0 * e^2 + a * (1 - e) * (1 + e) | |
3507 | * | |
3508 | * a3 = a2 * e + a * (1 - e) | |
3509 | * = (a0 * e^2 + a * (1 - e) * (1 + e)) * e + a * (1 - e) | |
3510 | * = a0 * e^3 + a * (1 - e) * (1 + e + e^2) | |
3511 | * | |
3512 | * ... | |
3513 | * | |
3514 | * an = a0 * e^n + a * (1 - e) * (1 + e + ... + e^n-1) [1] | |
3515 | * = a0 * e^n + a * (1 - e) * (1 - e^n)/(1 - e) | |
3516 | * = a0 * e^n + a * (1 - e^n) | |
3517 | * | |
3518 | * [1] application of the geometric series: | |
3519 | * | |
3520 | * n 1 - x^(n+1) | |
3521 | * S_n := \Sum x^i = ------------- | |
3522 | * i=0 1 - x | |
3523 | */ | |
3524 | static unsigned long | |
3525 | calc_load_n(unsigned long load, unsigned long exp, | |
3526 | unsigned long active, unsigned int n) | |
3527 | { | |
3528 | ||
3529 | return calc_load(load, fixed_power_int(exp, FSHIFT, n), active); | |
3530 | } | |
3531 | ||
3532 | /* | |
3533 | * NO_HZ can leave us missing all per-cpu ticks calling | |
3534 | * calc_load_account_active(), but since an idle CPU folds its delta into | |
3535 | * calc_load_tasks_idle per calc_load_account_idle(), all we need to do is fold | |
3536 | * in the pending idle delta if our idle period crossed a load cycle boundary. | |
3537 | * | |
3538 | * Once we've updated the global active value, we need to apply the exponential | |
3539 | * weights adjusted to the number of cycles missed. | |
3540 | */ | |
3541 | static void calc_global_nohz(unsigned long ticks) | |
3542 | { | |
3543 | long delta, active, n; | |
3544 | ||
3545 | if (time_before(jiffies, calc_load_update)) | |
3546 | return; | |
3547 | ||
3548 | /* | |
3549 | * If we crossed a calc_load_update boundary, make sure to fold | |
3550 | * any pending idle changes, the respective CPUs might have | |
3551 | * missed the tick driven calc_load_account_active() update | |
3552 | * due to NO_HZ. | |
3553 | */ | |
3554 | delta = calc_load_fold_idle(); | |
3555 | if (delta) | |
3556 | atomic_long_add(delta, &calc_load_tasks); | |
3557 | ||
3558 | /* | |
3559 | * If we were idle for multiple load cycles, apply them. | |
3560 | */ | |
3561 | if (ticks >= LOAD_FREQ) { | |
3562 | n = ticks / LOAD_FREQ; | |
3563 | ||
3564 | active = atomic_long_read(&calc_load_tasks); | |
3565 | active = active > 0 ? active * FIXED_1 : 0; | |
3566 | ||
3567 | avenrun[0] = calc_load_n(avenrun[0], EXP_1, active, n); | |
3568 | avenrun[1] = calc_load_n(avenrun[1], EXP_5, active, n); | |
3569 | avenrun[2] = calc_load_n(avenrun[2], EXP_15, active, n); | |
3570 | ||
3571 | calc_load_update += n * LOAD_FREQ; | |
3572 | } | |
3573 | ||
3574 | /* | |
3575 | * Its possible the remainder of the above division also crosses | |
3576 | * a LOAD_FREQ period, the regular check in calc_global_load() | |
3577 | * which comes after this will take care of that. | |
3578 | * | |
3579 | * Consider us being 11 ticks before a cycle completion, and us | |
3580 | * sleeping for 4*LOAD_FREQ + 22 ticks, then the above code will | |
3581 | * age us 4 cycles, and the test in calc_global_load() will | |
3582 | * pick up the final one. | |
3583 | */ | |
3584 | } | |
74f5187a PZ |
3585 | #else |
3586 | static void calc_load_account_idle(struct rq *this_rq) | |
3587 | { | |
3588 | } | |
3589 | ||
3590 | static inline long calc_load_fold_idle(void) | |
3591 | { | |
3592 | return 0; | |
3593 | } | |
0f004f5a PZ |
3594 | |
3595 | static void calc_global_nohz(unsigned long ticks) | |
3596 | { | |
3597 | } | |
74f5187a PZ |
3598 | #endif |
3599 | ||
2d02494f TG |
3600 | /** |
3601 | * get_avenrun - get the load average array | |
3602 | * @loads: pointer to dest load array | |
3603 | * @offset: offset to add | |
3604 | * @shift: shift count to shift the result left | |
3605 | * | |
3606 | * These values are estimates at best, so no need for locking. | |
3607 | */ | |
3608 | void get_avenrun(unsigned long *loads, unsigned long offset, int shift) | |
3609 | { | |
3610 | loads[0] = (avenrun[0] + offset) << shift; | |
3611 | loads[1] = (avenrun[1] + offset) << shift; | |
3612 | loads[2] = (avenrun[2] + offset) << shift; | |
46cb4b7c | 3613 | } |
46cb4b7c | 3614 | |
46cb4b7c | 3615 | /* |
dce48a84 TG |
3616 | * calc_load - update the avenrun load estimates 10 ticks after the |
3617 | * CPUs have updated calc_load_tasks. | |
7835b98b | 3618 | */ |
0f004f5a | 3619 | void calc_global_load(unsigned long ticks) |
7835b98b | 3620 | { |
dce48a84 | 3621 | long active; |
1da177e4 | 3622 | |
0f004f5a PZ |
3623 | calc_global_nohz(ticks); |
3624 | ||
3625 | if (time_before(jiffies, calc_load_update + 10)) | |
dce48a84 | 3626 | return; |
1da177e4 | 3627 | |
dce48a84 TG |
3628 | active = atomic_long_read(&calc_load_tasks); |
3629 | active = active > 0 ? active * FIXED_1 : 0; | |
1da177e4 | 3630 | |
dce48a84 TG |
3631 | avenrun[0] = calc_load(avenrun[0], EXP_1, active); |
3632 | avenrun[1] = calc_load(avenrun[1], EXP_5, active); | |
3633 | avenrun[2] = calc_load(avenrun[2], EXP_15, active); | |
dd41f596 | 3634 | |
dce48a84 TG |
3635 | calc_load_update += LOAD_FREQ; |
3636 | } | |
1da177e4 | 3637 | |
dce48a84 | 3638 | /* |
74f5187a PZ |
3639 | * Called from update_cpu_load() to periodically update this CPU's |
3640 | * active count. | |
dce48a84 TG |
3641 | */ |
3642 | static void calc_load_account_active(struct rq *this_rq) | |
3643 | { | |
74f5187a | 3644 | long delta; |
08c183f3 | 3645 | |
74f5187a PZ |
3646 | if (time_before(jiffies, this_rq->calc_load_update)) |
3647 | return; | |
783609c6 | 3648 | |
74f5187a PZ |
3649 | delta = calc_load_fold_active(this_rq); |
3650 | delta += calc_load_fold_idle(); | |
3651 | if (delta) | |
dce48a84 | 3652 | atomic_long_add(delta, &calc_load_tasks); |
74f5187a PZ |
3653 | |
3654 | this_rq->calc_load_update += LOAD_FREQ; | |
46cb4b7c SS |
3655 | } |
3656 | ||
fdf3e95d VP |
3657 | /* |
3658 | * The exact cpuload at various idx values, calculated at every tick would be | |
3659 | * load = (2^idx - 1) / 2^idx * load + 1 / 2^idx * cur_load | |
3660 | * | |
3661 | * If a cpu misses updates for n-1 ticks (as it was idle) and update gets called | |
3662 | * on nth tick when cpu may be busy, then we have: | |
3663 | * load = ((2^idx - 1) / 2^idx)^(n-1) * load | |
3664 | * load = (2^idx - 1) / 2^idx) * load + 1 / 2^idx * cur_load | |
3665 | * | |
3666 | * decay_load_missed() below does efficient calculation of | |
3667 | * load = ((2^idx - 1) / 2^idx)^(n-1) * load | |
3668 | * avoiding 0..n-1 loop doing load = ((2^idx - 1) / 2^idx) * load | |
3669 | * | |
3670 | * The calculation is approximated on a 128 point scale. | |
3671 | * degrade_zero_ticks is the number of ticks after which load at any | |
3672 | * particular idx is approximated to be zero. | |
3673 | * degrade_factor is a precomputed table, a row for each load idx. | |
3674 | * Each column corresponds to degradation factor for a power of two ticks, | |
3675 | * based on 128 point scale. | |
3676 | * Example: | |
3677 | * row 2, col 3 (=12) says that the degradation at load idx 2 after | |
3678 | * 8 ticks is 12/128 (which is an approximation of exact factor 3^8/4^8). | |
3679 | * | |
3680 | * With this power of 2 load factors, we can degrade the load n times | |
3681 | * by looking at 1 bits in n and doing as many mult/shift instead of | |
3682 | * n mult/shifts needed by the exact degradation. | |
3683 | */ | |
3684 | #define DEGRADE_SHIFT 7 | |
3685 | static const unsigned char | |
3686 | degrade_zero_ticks[CPU_LOAD_IDX_MAX] = {0, 8, 32, 64, 128}; | |
3687 | static const unsigned char | |
3688 | degrade_factor[CPU_LOAD_IDX_MAX][DEGRADE_SHIFT + 1] = { | |
3689 | {0, 0, 0, 0, 0, 0, 0, 0}, | |
3690 | {64, 32, 8, 0, 0, 0, 0, 0}, | |
3691 | {96, 72, 40, 12, 1, 0, 0}, | |
3692 | {112, 98, 75, 43, 15, 1, 0}, | |
3693 | {120, 112, 98, 76, 45, 16, 2} }; | |
3694 | ||
3695 | /* | |
3696 | * Update cpu_load for any missed ticks, due to tickless idle. The backlog | |
3697 | * would be when CPU is idle and so we just decay the old load without | |
3698 | * adding any new load. | |
3699 | */ | |
3700 | static unsigned long | |
3701 | decay_load_missed(unsigned long load, unsigned long missed_updates, int idx) | |
3702 | { | |
3703 | int j = 0; | |
3704 | ||
3705 | if (!missed_updates) | |
3706 | return load; | |
3707 | ||
3708 | if (missed_updates >= degrade_zero_ticks[idx]) | |
3709 | return 0; | |
3710 | ||
3711 | if (idx == 1) | |
3712 | return load >> missed_updates; | |
3713 | ||
3714 | while (missed_updates) { | |
3715 | if (missed_updates % 2) | |
3716 | load = (load * degrade_factor[idx][j]) >> DEGRADE_SHIFT; | |
3717 | ||
3718 | missed_updates >>= 1; | |
3719 | j++; | |
3720 | } | |
3721 | return load; | |
3722 | } | |
3723 | ||
46cb4b7c | 3724 | /* |
dd41f596 | 3725 | * Update rq->cpu_load[] statistics. This function is usually called every |
fdf3e95d VP |
3726 | * scheduler tick (TICK_NSEC). With tickless idle this will not be called |
3727 | * every tick. We fix it up based on jiffies. | |
46cb4b7c | 3728 | */ |
dd41f596 | 3729 | static void update_cpu_load(struct rq *this_rq) |
46cb4b7c | 3730 | { |
495eca49 | 3731 | unsigned long this_load = this_rq->load.weight; |
fdf3e95d VP |
3732 | unsigned long curr_jiffies = jiffies; |
3733 | unsigned long pending_updates; | |
dd41f596 | 3734 | int i, scale; |
46cb4b7c | 3735 | |
dd41f596 | 3736 | this_rq->nr_load_updates++; |
46cb4b7c | 3737 | |
fdf3e95d VP |
3738 | /* Avoid repeated calls on same jiffy, when moving in and out of idle */ |
3739 | if (curr_jiffies == this_rq->last_load_update_tick) | |
3740 | return; | |
3741 | ||
3742 | pending_updates = curr_jiffies - this_rq->last_load_update_tick; | |
3743 | this_rq->last_load_update_tick = curr_jiffies; | |
3744 | ||
dd41f596 | 3745 | /* Update our load: */ |
fdf3e95d VP |
3746 | this_rq->cpu_load[0] = this_load; /* Fasttrack for idx 0 */ |
3747 | for (i = 1, scale = 2; i < CPU_LOAD_IDX_MAX; i++, scale += scale) { | |
dd41f596 | 3748 | unsigned long old_load, new_load; |
7d1e6a9b | 3749 | |
dd41f596 | 3750 | /* scale is effectively 1 << i now, and >> i divides by scale */ |
46cb4b7c | 3751 | |
dd41f596 | 3752 | old_load = this_rq->cpu_load[i]; |
fdf3e95d | 3753 | old_load = decay_load_missed(old_load, pending_updates - 1, i); |
dd41f596 | 3754 | new_load = this_load; |
a25707f3 IM |
3755 | /* |
3756 | * Round up the averaging division if load is increasing. This | |
3757 | * prevents us from getting stuck on 9 if the load is 10, for | |
3758 | * example. | |
3759 | */ | |
3760 | if (new_load > old_load) | |
fdf3e95d VP |
3761 | new_load += scale - 1; |
3762 | ||
3763 | this_rq->cpu_load[i] = (old_load * (scale - 1) + new_load) >> i; | |
dd41f596 | 3764 | } |
da2b71ed SS |
3765 | |
3766 | sched_avg_update(this_rq); | |
fdf3e95d VP |
3767 | } |
3768 | ||
3769 | static void update_cpu_load_active(struct rq *this_rq) | |
3770 | { | |
3771 | update_cpu_load(this_rq); | |
46cb4b7c | 3772 | |
74f5187a | 3773 | calc_load_account_active(this_rq); |
46cb4b7c SS |
3774 | } |
3775 | ||
dd41f596 | 3776 | #ifdef CONFIG_SMP |
8a0be9ef | 3777 | |
46cb4b7c | 3778 | /* |
38022906 PZ |
3779 | * sched_exec - execve() is a valuable balancing opportunity, because at |
3780 | * this point the task has the smallest effective memory and cache footprint. | |
46cb4b7c | 3781 | */ |
38022906 | 3782 | void sched_exec(void) |
46cb4b7c | 3783 | { |
38022906 | 3784 | struct task_struct *p = current; |
1da177e4 | 3785 | unsigned long flags; |
0017d735 | 3786 | int dest_cpu; |
46cb4b7c | 3787 | |
8f42ced9 | 3788 | raw_spin_lock_irqsave(&p->pi_lock, flags); |
7608dec2 | 3789 | dest_cpu = p->sched_class->select_task_rq(p, SD_BALANCE_EXEC, 0); |
0017d735 PZ |
3790 | if (dest_cpu == smp_processor_id()) |
3791 | goto unlock; | |
38022906 | 3792 | |
8f42ced9 | 3793 | if (likely(cpu_active(dest_cpu))) { |
969c7921 | 3794 | struct migration_arg arg = { p, dest_cpu }; |
46cb4b7c | 3795 | |
8f42ced9 PZ |
3796 | raw_spin_unlock_irqrestore(&p->pi_lock, flags); |
3797 | stop_one_cpu(task_cpu(p), migration_cpu_stop, &arg); | |
1da177e4 LT |
3798 | return; |
3799 | } | |
0017d735 | 3800 | unlock: |
8f42ced9 | 3801 | raw_spin_unlock_irqrestore(&p->pi_lock, flags); |
1da177e4 | 3802 | } |
dd41f596 | 3803 | |
1da177e4 LT |
3804 | #endif |
3805 | ||
1da177e4 LT |
3806 | DEFINE_PER_CPU(struct kernel_stat, kstat); |
3807 | ||
3808 | EXPORT_PER_CPU_SYMBOL(kstat); | |
3809 | ||
3810 | /* | |
c5f8d995 | 3811 | * Return any ns on the sched_clock that have not yet been accounted in |
f06febc9 | 3812 | * @p in case that task is currently running. |
c5f8d995 HS |
3813 | * |
3814 | * Called with task_rq_lock() held on @rq. | |
1da177e4 | 3815 | */ |
c5f8d995 HS |
3816 | static u64 do_task_delta_exec(struct task_struct *p, struct rq *rq) |
3817 | { | |
3818 | u64 ns = 0; | |
3819 | ||
3820 | if (task_current(rq, p)) { | |
3821 | update_rq_clock(rq); | |
305e6835 | 3822 | ns = rq->clock_task - p->se.exec_start; |
c5f8d995 HS |
3823 | if ((s64)ns < 0) |
3824 | ns = 0; | |
3825 | } | |
3826 | ||
3827 | return ns; | |
3828 | } | |
3829 | ||
bb34d92f | 3830 | unsigned long long task_delta_exec(struct task_struct *p) |
1da177e4 | 3831 | { |
1da177e4 | 3832 | unsigned long flags; |
41b86e9c | 3833 | struct rq *rq; |
bb34d92f | 3834 | u64 ns = 0; |
48f24c4d | 3835 | |
41b86e9c | 3836 | rq = task_rq_lock(p, &flags); |
c5f8d995 | 3837 | ns = do_task_delta_exec(p, rq); |
0122ec5b | 3838 | task_rq_unlock(rq, p, &flags); |
1508487e | 3839 | |
c5f8d995 HS |
3840 | return ns; |
3841 | } | |
f06febc9 | 3842 | |
c5f8d995 HS |
3843 | /* |
3844 | * Return accounted runtime for the task. | |
3845 | * In case the task is currently running, return the runtime plus current's | |
3846 | * pending runtime that have not been accounted yet. | |
3847 | */ | |
3848 | unsigned long long task_sched_runtime(struct task_struct *p) | |
3849 | { | |
3850 | unsigned long flags; | |
3851 | struct rq *rq; | |
3852 | u64 ns = 0; | |
3853 | ||
3854 | rq = task_rq_lock(p, &flags); | |
3855 | ns = p->se.sum_exec_runtime + do_task_delta_exec(p, rq); | |
0122ec5b | 3856 | task_rq_unlock(rq, p, &flags); |
c5f8d995 HS |
3857 | |
3858 | return ns; | |
3859 | } | |
48f24c4d | 3860 | |
1da177e4 LT |
3861 | /* |
3862 | * Account user cpu time to a process. | |
3863 | * @p: the process that the cpu time gets accounted to | |
1da177e4 | 3864 | * @cputime: the cpu time spent in user space since the last update |
457533a7 | 3865 | * @cputime_scaled: cputime scaled by cpu frequency |
1da177e4 | 3866 | */ |
457533a7 MS |
3867 | void account_user_time(struct task_struct *p, cputime_t cputime, |
3868 | cputime_t cputime_scaled) | |
1da177e4 LT |
3869 | { |
3870 | struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat; | |
1da177e4 | 3871 | |
457533a7 | 3872 | /* Add user time to process. */ |
64861634 MS |
3873 | p->utime += cputime; |
3874 | p->utimescaled += cputime_scaled; | |
f06febc9 | 3875 | account_group_user_time(p, cputime); |
1da177e4 LT |
3876 | |
3877 | /* Add user time to cpustat. */ | |
1da177e4 | 3878 | if (TASK_NICE(p) > 0) |
64861634 | 3879 | cpustat->nice += (__force cputime64_t) cputime; |
1da177e4 | 3880 | else |
64861634 | 3881 | cpustat->user += (__force cputime64_t) cputime; |
ef12fefa BR |
3882 | |
3883 | cpuacct_update_stats(p, CPUACCT_STAT_USER, cputime); | |
49b5cf34 JL |
3884 | /* Account for user time used */ |
3885 | acct_update_integrals(p); | |
1da177e4 LT |
3886 | } |
3887 | ||
94886b84 LV |
3888 | /* |
3889 | * Account guest cpu time to a process. | |
3890 | * @p: the process that the cpu time gets accounted to | |
3891 | * @cputime: the cpu time spent in virtual machine since the last update | |
457533a7 | 3892 | * @cputime_scaled: cputime scaled by cpu frequency |
94886b84 | 3893 | */ |
457533a7 MS |
3894 | static void account_guest_time(struct task_struct *p, cputime_t cputime, |
3895 | cputime_t cputime_scaled) | |
94886b84 | 3896 | { |
94886b84 LV |
3897 | struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat; |
3898 | ||
457533a7 | 3899 | /* Add guest time to process. */ |
64861634 MS |
3900 | p->utime += cputime; |
3901 | p->utimescaled += cputime_scaled; | |
f06febc9 | 3902 | account_group_user_time(p, cputime); |
64861634 | 3903 | p->gtime += cputime; |
94886b84 | 3904 | |
457533a7 | 3905 | /* Add guest time to cpustat. */ |
ce0e7b28 | 3906 | if (TASK_NICE(p) > 0) { |
64861634 MS |
3907 | cpustat->nice += (__force cputime64_t) cputime; |
3908 | cpustat->guest_nice += (__force cputime64_t) cputime; | |
ce0e7b28 | 3909 | } else { |
64861634 MS |
3910 | cpustat->user += (__force cputime64_t) cputime; |
3911 | cpustat->guest += (__force cputime64_t) cputime; | |
ce0e7b28 | 3912 | } |
94886b84 LV |
3913 | } |
3914 | ||
70a89a66 VP |
3915 | /* |
3916 | * Account system cpu time to a process and desired cpustat field | |
3917 | * @p: the process that the cpu time gets accounted to | |
3918 | * @cputime: the cpu time spent in kernel space since the last update | |
3919 | * @cputime_scaled: cputime scaled by cpu frequency | |
3920 | * @target_cputime64: pointer to cpustat field that has to be updated | |
3921 | */ | |
3922 | static inline | |
3923 | void __account_system_time(struct task_struct *p, cputime_t cputime, | |
3924 | cputime_t cputime_scaled, cputime64_t *target_cputime64) | |
3925 | { | |
70a89a66 | 3926 | /* Add system time to process. */ |
64861634 MS |
3927 | p->stime += cputime; |
3928 | p->stimescaled += cputime_scaled; | |
70a89a66 VP |
3929 | account_group_system_time(p, cputime); |
3930 | ||
3931 | /* Add system time to cpustat. */ | |
64861634 | 3932 | *target_cputime64 += (__force cputime64_t) cputime; |
70a89a66 VP |
3933 | cpuacct_update_stats(p, CPUACCT_STAT_SYSTEM, cputime); |
3934 | ||
3935 | /* Account for system time used */ | |
3936 | acct_update_integrals(p); | |
3937 | } | |
3938 | ||
1da177e4 LT |
3939 | /* |
3940 | * Account system cpu time to a process. | |
3941 | * @p: the process that the cpu time gets accounted to | |
3942 | * @hardirq_offset: the offset to subtract from hardirq_count() | |
3943 | * @cputime: the cpu time spent in kernel space since the last update | |
457533a7 | 3944 | * @cputime_scaled: cputime scaled by cpu frequency |
1da177e4 LT |
3945 | */ |
3946 | void account_system_time(struct task_struct *p, int hardirq_offset, | |
457533a7 | 3947 | cputime_t cputime, cputime_t cputime_scaled) |
1da177e4 LT |
3948 | { |
3949 | struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat; | |
70a89a66 | 3950 | cputime64_t *target_cputime64; |
1da177e4 | 3951 | |
983ed7a6 | 3952 | if ((p->flags & PF_VCPU) && (irq_count() - hardirq_offset == 0)) { |
457533a7 | 3953 | account_guest_time(p, cputime, cputime_scaled); |
983ed7a6 HH |
3954 | return; |
3955 | } | |
94886b84 | 3956 | |
1da177e4 | 3957 | if (hardirq_count() - hardirq_offset) |
70a89a66 | 3958 | target_cputime64 = &cpustat->irq; |
75e1056f | 3959 | else if (in_serving_softirq()) |
70a89a66 | 3960 | target_cputime64 = &cpustat->softirq; |
1da177e4 | 3961 | else |
70a89a66 | 3962 | target_cputime64 = &cpustat->system; |
ef12fefa | 3963 | |
70a89a66 | 3964 | __account_system_time(p, cputime, cputime_scaled, target_cputime64); |
1da177e4 LT |
3965 | } |
3966 | ||
c66f08be | 3967 | /* |
1da177e4 | 3968 | * Account for involuntary wait time. |
544b4a1f | 3969 | * @cputime: the cpu time spent in involuntary wait |
c66f08be | 3970 | */ |
79741dd3 | 3971 | void account_steal_time(cputime_t cputime) |
c66f08be | 3972 | { |
79741dd3 | 3973 | struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat; |
79741dd3 | 3974 | |
64861634 | 3975 | cpustat->steal += (__force cputime64_t) cputime; |
c66f08be MN |
3976 | } |
3977 | ||
1da177e4 | 3978 | /* |
79741dd3 MS |
3979 | * Account for idle time. |
3980 | * @cputime: the cpu time spent in idle wait | |
1da177e4 | 3981 | */ |
79741dd3 | 3982 | void account_idle_time(cputime_t cputime) |
1da177e4 LT |
3983 | { |
3984 | struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat; | |
70b97a7f | 3985 | struct rq *rq = this_rq(); |
1da177e4 | 3986 | |
79741dd3 | 3987 | if (atomic_read(&rq->nr_iowait) > 0) |
64861634 | 3988 | cpustat->iowait += (__force cputime64_t) cputime; |
79741dd3 | 3989 | else |
64861634 | 3990 | cpustat->idle += (__force cputime64_t) cputime; |
1da177e4 LT |
3991 | } |
3992 | ||
e6e6685a GC |
3993 | static __always_inline bool steal_account_process_tick(void) |
3994 | { | |
3995 | #ifdef CONFIG_PARAVIRT | |
3996 | if (static_branch(¶virt_steal_enabled)) { | |
3997 | u64 steal, st = 0; | |
3998 | ||
3999 | steal = paravirt_steal_clock(smp_processor_id()); | |
4000 | steal -= this_rq()->prev_steal_time; | |
4001 | ||
4002 | st = steal_ticks(steal); | |
4003 | this_rq()->prev_steal_time += st * TICK_NSEC; | |
4004 | ||
4005 | account_steal_time(st); | |
4006 | return st; | |
4007 | } | |
4008 | #endif | |
4009 | return false; | |
4010 | } | |
4011 | ||
79741dd3 MS |
4012 | #ifndef CONFIG_VIRT_CPU_ACCOUNTING |
4013 | ||
abb74cef VP |
4014 | #ifdef CONFIG_IRQ_TIME_ACCOUNTING |
4015 | /* | |
4016 | * Account a tick to a process and cpustat | |
4017 | * @p: the process that the cpu time gets accounted to | |
4018 | * @user_tick: is the tick from userspace | |
4019 | * @rq: the pointer to rq | |
4020 | * | |
4021 | * Tick demultiplexing follows the order | |
4022 | * - pending hardirq update | |
4023 | * - pending softirq update | |
4024 | * - user_time | |
4025 | * - idle_time | |
4026 | * - system time | |
4027 | * - check for guest_time | |
4028 | * - else account as system_time | |
4029 | * | |
4030 | * Check for hardirq is done both for system and user time as there is | |
4031 | * no timer going off while we are on hardirq and hence we may never get an | |
4032 | * opportunity to update it solely in system time. | |
4033 | * p->stime and friends are only updated on system time and not on irq | |
4034 | * softirq as those do not count in task exec_runtime any more. | |
4035 | */ | |
4036 | static void irqtime_account_process_tick(struct task_struct *p, int user_tick, | |
4037 | struct rq *rq) | |
4038 | { | |
4039 | cputime_t one_jiffy_scaled = cputime_to_scaled(cputime_one_jiffy); | |
abb74cef VP |
4040 | struct cpu_usage_stat *cpustat = &kstat_this_cpu.cpustat; |
4041 | ||
e6e6685a GC |
4042 | if (steal_account_process_tick()) |
4043 | return; | |
4044 | ||
abb74cef | 4045 | if (irqtime_account_hi_update()) { |
64861634 | 4046 | cpustat->irq += (__force cputime64_t) cputime_one_jiffy; |
abb74cef | 4047 | } else if (irqtime_account_si_update()) { |
64861634 | 4048 | cpustat->softirq += (__force cputime64_t) cputime_one_jiffy; |
414bee9b VP |
4049 | } else if (this_cpu_ksoftirqd() == p) { |
4050 | /* | |
4051 | * ksoftirqd time do not get accounted in cpu_softirq_time. | |
4052 | * So, we have to handle it separately here. | |
4053 | * Also, p->stime needs to be updated for ksoftirqd. | |
4054 | */ | |
4055 | __account_system_time(p, cputime_one_jiffy, one_jiffy_scaled, | |
4056 | &cpustat->softirq); | |
abb74cef VP |
4057 | } else if (user_tick) { |
4058 | account_user_time(p, cputime_one_jiffy, one_jiffy_scaled); | |
4059 | } else if (p == rq->idle) { | |
4060 | account_idle_time(cputime_one_jiffy); | |
4061 | } else if (p->flags & PF_VCPU) { /* System time or guest time */ | |
4062 | account_guest_time(p, cputime_one_jiffy, one_jiffy_scaled); | |
4063 | } else { | |
4064 | __account_system_time(p, cputime_one_jiffy, one_jiffy_scaled, | |
4065 | &cpustat->system); | |
4066 | } | |
4067 | } | |
4068 | ||
4069 | static void irqtime_account_idle_ticks(int ticks) | |
4070 | { | |
4071 | int i; | |
4072 | struct rq *rq = this_rq(); | |
4073 | ||
4074 | for (i = 0; i < ticks; i++) | |
4075 | irqtime_account_process_tick(current, 0, rq); | |
4076 | } | |
544b4a1f | 4077 | #else /* CONFIG_IRQ_TIME_ACCOUNTING */ |
abb74cef VP |
4078 | static void irqtime_account_idle_ticks(int ticks) {} |
4079 | static void irqtime_account_process_tick(struct task_struct *p, int user_tick, | |
4080 | struct rq *rq) {} | |
544b4a1f | 4081 | #endif /* CONFIG_IRQ_TIME_ACCOUNTING */ |
79741dd3 MS |
4082 | |
4083 | /* | |
4084 | * Account a single tick of cpu time. | |
4085 | * @p: the process that the cpu time gets accounted to | |
4086 | * @user_tick: indicates if the tick is a user or a system tick | |
4087 | */ | |
4088 | void account_process_tick(struct task_struct *p, int user_tick) | |
4089 | { | |
a42548a1 | 4090 | cputime_t one_jiffy_scaled = cputime_to_scaled(cputime_one_jiffy); |
79741dd3 MS |
4091 | struct rq *rq = this_rq(); |
4092 | ||
abb74cef VP |
4093 | if (sched_clock_irqtime) { |
4094 | irqtime_account_process_tick(p, user_tick, rq); | |
4095 | return; | |
4096 | } | |
4097 | ||
e6e6685a GC |
4098 | if (steal_account_process_tick()) |
4099 | return; | |
4100 | ||
79741dd3 | 4101 | if (user_tick) |
a42548a1 | 4102 | account_user_time(p, cputime_one_jiffy, one_jiffy_scaled); |
f5f293a4 | 4103 | else if ((p != rq->idle) || (irq_count() != HARDIRQ_OFFSET)) |
a42548a1 | 4104 | account_system_time(p, HARDIRQ_OFFSET, cputime_one_jiffy, |
79741dd3 MS |
4105 | one_jiffy_scaled); |
4106 | else | |
a42548a1 | 4107 | account_idle_time(cputime_one_jiffy); |
79741dd3 MS |
4108 | } |
4109 | ||
4110 | /* | |
4111 | * Account multiple ticks of steal time. | |
4112 | * @p: the process from which the cpu time has been stolen | |
4113 | * @ticks: number of stolen ticks | |
4114 | */ | |
4115 | void account_steal_ticks(unsigned long ticks) | |
4116 | { | |
4117 | account_steal_time(jiffies_to_cputime(ticks)); | |
4118 | } | |
4119 | ||
4120 | /* | |
4121 | * Account multiple ticks of idle time. | |
4122 | * @ticks: number of stolen ticks | |
4123 | */ | |
4124 | void account_idle_ticks(unsigned long ticks) | |
4125 | { | |
abb74cef VP |
4126 | |
4127 | if (sched_clock_irqtime) { | |
4128 | irqtime_account_idle_ticks(ticks); | |
4129 | return; | |
4130 | } | |
4131 | ||
79741dd3 | 4132 | account_idle_time(jiffies_to_cputime(ticks)); |
1da177e4 LT |
4133 | } |
4134 | ||
79741dd3 MS |
4135 | #endif |
4136 | ||
49048622 BS |
4137 | /* |
4138 | * Use precise platform statistics if available: | |
4139 | */ | |
4140 | #ifdef CONFIG_VIRT_CPU_ACCOUNTING | |
d180c5bc | 4141 | void task_times(struct task_struct *p, cputime_t *ut, cputime_t *st) |
49048622 | 4142 | { |
d99ca3b9 HS |
4143 | *ut = p->utime; |
4144 | *st = p->stime; | |
49048622 BS |
4145 | } |
4146 | ||
0cf55e1e | 4147 | void thread_group_times(struct task_struct *p, cputime_t *ut, cputime_t *st) |
49048622 | 4148 | { |
0cf55e1e HS |
4149 | struct task_cputime cputime; |
4150 | ||
4151 | thread_group_cputime(p, &cputime); | |
4152 | ||
4153 | *ut = cputime.utime; | |
4154 | *st = cputime.stime; | |
49048622 BS |
4155 | } |
4156 | #else | |
761b1d26 HS |
4157 | |
4158 | #ifndef nsecs_to_cputime | |
b7b20df9 | 4159 | # define nsecs_to_cputime(__nsecs) nsecs_to_jiffies(__nsecs) |
761b1d26 HS |
4160 | #endif |
4161 | ||
d180c5bc | 4162 | void task_times(struct task_struct *p, cputime_t *ut, cputime_t *st) |
49048622 | 4163 | { |
64861634 | 4164 | cputime_t rtime, utime = p->utime, total = utime + p->stime; |
49048622 BS |
4165 | |
4166 | /* | |
4167 | * Use CFS's precise accounting: | |
4168 | */ | |
d180c5bc | 4169 | rtime = nsecs_to_cputime(p->se.sum_exec_runtime); |
49048622 BS |
4170 | |
4171 | if (total) { | |
64861634 | 4172 | u64 temp = (__force u64) rtime; |
d180c5bc | 4173 | |
64861634 MS |
4174 | temp *= (__force u64) utime; |
4175 | do_div(temp, (__force u32) total); | |
4176 | utime = (__force cputime_t) temp; | |
d180c5bc HS |
4177 | } else |
4178 | utime = rtime; | |
49048622 | 4179 | |
d180c5bc HS |
4180 | /* |
4181 | * Compare with previous values, to keep monotonicity: | |
4182 | */ | |
761b1d26 | 4183 | p->prev_utime = max(p->prev_utime, utime); |
64861634 | 4184 | p->prev_stime = max(p->prev_stime, rtime - p->prev_utime); |
49048622 | 4185 | |
d99ca3b9 HS |
4186 | *ut = p->prev_utime; |
4187 | *st = p->prev_stime; | |
49048622 BS |
4188 | } |
4189 | ||
0cf55e1e HS |
4190 | /* |
4191 | * Must be called with siglock held. | |
4192 | */ | |
4193 | void thread_group_times(struct task_struct *p, cputime_t *ut, cputime_t *st) | |
49048622 | 4194 | { |
0cf55e1e HS |
4195 | struct signal_struct *sig = p->signal; |
4196 | struct task_cputime cputime; | |
4197 | cputime_t rtime, utime, total; | |
49048622 | 4198 | |
0cf55e1e | 4199 | thread_group_cputime(p, &cputime); |
49048622 | 4200 | |
64861634 | 4201 | total = cputime.utime + cputime.stime; |
0cf55e1e | 4202 | rtime = nsecs_to_cputime(cputime.sum_exec_runtime); |
49048622 | 4203 | |
0cf55e1e | 4204 | if (total) { |
64861634 | 4205 | u64 temp = (__force u64) rtime; |
49048622 | 4206 | |
64861634 MS |
4207 | temp *= (__force u64) cputime.utime; |
4208 | do_div(temp, (__force u32) total); | |
4209 | utime = (__force cputime_t) temp; | |
0cf55e1e HS |
4210 | } else |
4211 | utime = rtime; | |
4212 | ||
4213 | sig->prev_utime = max(sig->prev_utime, utime); | |
64861634 | 4214 | sig->prev_stime = max(sig->prev_stime, rtime - sig->prev_utime); |
0cf55e1e HS |
4215 | |
4216 | *ut = sig->prev_utime; | |
4217 | *st = sig->prev_stime; | |
49048622 | 4218 | } |
49048622 | 4219 | #endif |
49048622 | 4220 | |
7835b98b CL |
4221 | /* |
4222 | * This function gets called by the timer code, with HZ frequency. | |
4223 | * We call it with interrupts disabled. | |
7835b98b CL |
4224 | */ |
4225 | void scheduler_tick(void) | |
4226 | { | |
7835b98b CL |
4227 | int cpu = smp_processor_id(); |
4228 | struct rq *rq = cpu_rq(cpu); | |
dd41f596 | 4229 | struct task_struct *curr = rq->curr; |
3e51f33f PZ |
4230 | |
4231 | sched_clock_tick(); | |
dd41f596 | 4232 | |
05fa785c | 4233 | raw_spin_lock(&rq->lock); |
3e51f33f | 4234 | update_rq_clock(rq); |
fdf3e95d | 4235 | update_cpu_load_active(rq); |
fa85ae24 | 4236 | curr->sched_class->task_tick(rq, curr, 0); |
05fa785c | 4237 | raw_spin_unlock(&rq->lock); |
7835b98b | 4238 | |
e9d2b064 | 4239 | perf_event_task_tick(); |
e220d2dc | 4240 | |
e418e1c2 | 4241 | #ifdef CONFIG_SMP |
6eb57e0d | 4242 | rq->idle_balance = idle_cpu(cpu); |
dd41f596 | 4243 | trigger_load_balance(rq, cpu); |
e418e1c2 | 4244 | #endif |
1da177e4 LT |
4245 | } |
4246 | ||
132380a0 | 4247 | notrace unsigned long get_parent_ip(unsigned long addr) |
6cd8a4bb SR |
4248 | { |
4249 | if (in_lock_functions(addr)) { | |
4250 | addr = CALLER_ADDR2; | |
4251 | if (in_lock_functions(addr)) | |
4252 | addr = CALLER_ADDR3; | |
4253 | } | |
4254 | return addr; | |
4255 | } | |
1da177e4 | 4256 | |
7e49fcce SR |
4257 | #if defined(CONFIG_PREEMPT) && (defined(CONFIG_DEBUG_PREEMPT) || \ |
4258 | defined(CONFIG_PREEMPT_TRACER)) | |
4259 | ||
43627582 | 4260 | void __kprobes add_preempt_count(int val) |
1da177e4 | 4261 | { |
6cd8a4bb | 4262 | #ifdef CONFIG_DEBUG_PREEMPT |
1da177e4 LT |
4263 | /* |
4264 | * Underflow? | |
4265 | */ | |
9a11b49a IM |
4266 | if (DEBUG_LOCKS_WARN_ON((preempt_count() < 0))) |
4267 | return; | |
6cd8a4bb | 4268 | #endif |
1da177e4 | 4269 | preempt_count() += val; |
6cd8a4bb | 4270 | #ifdef CONFIG_DEBUG_PREEMPT |
1da177e4 LT |
4271 | /* |
4272 | * Spinlock count overflowing soon? | |
4273 | */ | |
33859f7f MOS |
4274 | DEBUG_LOCKS_WARN_ON((preempt_count() & PREEMPT_MASK) >= |
4275 | PREEMPT_MASK - 10); | |
6cd8a4bb SR |
4276 | #endif |
4277 | if (preempt_count() == val) | |
4278 | trace_preempt_off(CALLER_ADDR0, get_parent_ip(CALLER_ADDR1)); | |
1da177e4 LT |
4279 | } |
4280 | EXPORT_SYMBOL(add_preempt_count); | |
4281 | ||
43627582 | 4282 | void __kprobes sub_preempt_count(int val) |
1da177e4 | 4283 | { |
6cd8a4bb | 4284 | #ifdef CONFIG_DEBUG_PREEMPT |
1da177e4 LT |
4285 | /* |
4286 | * Underflow? | |
4287 | */ | |
01e3eb82 | 4288 | if (DEBUG_LOCKS_WARN_ON(val > preempt_count())) |
9a11b49a | 4289 | return; |
1da177e4 LT |
4290 | /* |
4291 | * Is the spinlock portion underflowing? | |
4292 | */ | |
9a11b49a IM |
4293 | if (DEBUG_LOCKS_WARN_ON((val < PREEMPT_MASK) && |
4294 | !(preempt_count() & PREEMPT_MASK))) | |
4295 | return; | |
6cd8a4bb | 4296 | #endif |
9a11b49a | 4297 | |
6cd8a4bb SR |
4298 | if (preempt_count() == val) |
4299 | trace_preempt_on(CALLER_ADDR0, get_parent_ip(CALLER_ADDR1)); | |
1da177e4 LT |
4300 | preempt_count() -= val; |
4301 | } | |
4302 | EXPORT_SYMBOL(sub_preempt_count); | |
4303 | ||
4304 | #endif | |
4305 | ||
4306 | /* | |
dd41f596 | 4307 | * Print scheduling while atomic bug: |
1da177e4 | 4308 | */ |
dd41f596 | 4309 | static noinline void __schedule_bug(struct task_struct *prev) |
1da177e4 | 4310 | { |
838225b4 SS |
4311 | struct pt_regs *regs = get_irq_regs(); |
4312 | ||
3df0fc5b PZ |
4313 | printk(KERN_ERR "BUG: scheduling while atomic: %s/%d/0x%08x\n", |
4314 | prev->comm, prev->pid, preempt_count()); | |
838225b4 | 4315 | |
dd41f596 | 4316 | debug_show_held_locks(prev); |
e21f5b15 | 4317 | print_modules(); |
dd41f596 IM |
4318 | if (irqs_disabled()) |
4319 | print_irqtrace_events(prev); | |
838225b4 SS |
4320 | |
4321 | if (regs) | |
4322 | show_regs(regs); | |
4323 | else | |
4324 | dump_stack(); | |
dd41f596 | 4325 | } |
1da177e4 | 4326 | |
dd41f596 IM |
4327 | /* |
4328 | * Various schedule()-time debugging checks and statistics: | |
4329 | */ | |
4330 | static inline void schedule_debug(struct task_struct *prev) | |
4331 | { | |
1da177e4 | 4332 | /* |
41a2d6cf | 4333 | * Test if we are atomic. Since do_exit() needs to call into |
1da177e4 LT |
4334 | * schedule() atomically, we ignore that path for now. |
4335 | * Otherwise, whine if we are scheduling when we should not be. | |
4336 | */ | |
3f33a7ce | 4337 | if (unlikely(in_atomic_preempt_off() && !prev->exit_state)) |
dd41f596 | 4338 | __schedule_bug(prev); |
b3fbab05 | 4339 | rcu_sleep_check(); |
dd41f596 | 4340 | |
1da177e4 LT |
4341 | profile_hit(SCHED_PROFILING, __builtin_return_address(0)); |
4342 | ||
2d72376b | 4343 | schedstat_inc(this_rq(), sched_count); |
dd41f596 IM |
4344 | } |
4345 | ||
6cecd084 | 4346 | static void put_prev_task(struct rq *rq, struct task_struct *prev) |
df1c99d4 | 4347 | { |
61eadef6 | 4348 | if (prev->on_rq || rq->skip_clock_update < 0) |
a64692a3 | 4349 | update_rq_clock(rq); |
6cecd084 | 4350 | prev->sched_class->put_prev_task(rq, prev); |
df1c99d4 MG |
4351 | } |
4352 | ||
dd41f596 IM |
4353 | /* |
4354 | * Pick up the highest-prio task: | |
4355 | */ | |
4356 | static inline struct task_struct * | |
b67802ea | 4357 | pick_next_task(struct rq *rq) |
dd41f596 | 4358 | { |
5522d5d5 | 4359 | const struct sched_class *class; |
dd41f596 | 4360 | struct task_struct *p; |
1da177e4 LT |
4361 | |
4362 | /* | |
dd41f596 IM |
4363 | * Optimization: we know that if all tasks are in |
4364 | * the fair class we can call that function directly: | |
1da177e4 | 4365 | */ |
953bfcd1 | 4366 | if (likely(rq->nr_running == rq->cfs.h_nr_running)) { |
fb8d4724 | 4367 | p = fair_sched_class.pick_next_task(rq); |
dd41f596 IM |
4368 | if (likely(p)) |
4369 | return p; | |
1da177e4 LT |
4370 | } |
4371 | ||
34f971f6 | 4372 | for_each_class(class) { |
fb8d4724 | 4373 | p = class->pick_next_task(rq); |
dd41f596 IM |
4374 | if (p) |
4375 | return p; | |
dd41f596 | 4376 | } |
34f971f6 PZ |
4377 | |
4378 | BUG(); /* the idle class will always have a runnable task */ | |
dd41f596 | 4379 | } |
1da177e4 | 4380 | |
dd41f596 | 4381 | /* |
c259e01a | 4382 | * __schedule() is the main scheduler function. |
dd41f596 | 4383 | */ |
c259e01a | 4384 | static void __sched __schedule(void) |
dd41f596 IM |
4385 | { |
4386 | struct task_struct *prev, *next; | |
67ca7bde | 4387 | unsigned long *switch_count; |
dd41f596 | 4388 | struct rq *rq; |
31656519 | 4389 | int cpu; |
dd41f596 | 4390 | |
ff743345 PZ |
4391 | need_resched: |
4392 | preempt_disable(); | |
dd41f596 IM |
4393 | cpu = smp_processor_id(); |
4394 | rq = cpu_rq(cpu); | |
25502a6c | 4395 | rcu_note_context_switch(cpu); |
dd41f596 | 4396 | prev = rq->curr; |
dd41f596 | 4397 | |
dd41f596 | 4398 | schedule_debug(prev); |
1da177e4 | 4399 | |
31656519 | 4400 | if (sched_feat(HRTICK)) |
f333fdc9 | 4401 | hrtick_clear(rq); |
8f4d37ec | 4402 | |
05fa785c | 4403 | raw_spin_lock_irq(&rq->lock); |
1da177e4 | 4404 | |
246d86b5 | 4405 | switch_count = &prev->nivcsw; |
1da177e4 | 4406 | if (prev->state && !(preempt_count() & PREEMPT_ACTIVE)) { |
21aa9af0 | 4407 | if (unlikely(signal_pending_state(prev->state, prev))) { |
1da177e4 | 4408 | prev->state = TASK_RUNNING; |
21aa9af0 | 4409 | } else { |
2acca55e PZ |
4410 | deactivate_task(rq, prev, DEQUEUE_SLEEP); |
4411 | prev->on_rq = 0; | |
4412 | ||
21aa9af0 | 4413 | /* |
2acca55e PZ |
4414 | * If a worker went to sleep, notify and ask workqueue |
4415 | * whether it wants to wake up a task to maintain | |
4416 | * concurrency. | |
21aa9af0 TH |
4417 | */ |
4418 | if (prev->flags & PF_WQ_WORKER) { | |
4419 | struct task_struct *to_wakeup; | |
4420 | ||
4421 | to_wakeup = wq_worker_sleeping(prev, cpu); | |
4422 | if (to_wakeup) | |
4423 | try_to_wake_up_local(to_wakeup); | |
4424 | } | |
21aa9af0 | 4425 | } |
dd41f596 | 4426 | switch_count = &prev->nvcsw; |
1da177e4 LT |
4427 | } |
4428 | ||
3f029d3c | 4429 | pre_schedule(rq, prev); |
f65eda4f | 4430 | |
dd41f596 | 4431 | if (unlikely(!rq->nr_running)) |
1da177e4 | 4432 | idle_balance(cpu, rq); |
1da177e4 | 4433 | |
df1c99d4 | 4434 | put_prev_task(rq, prev); |
b67802ea | 4435 | next = pick_next_task(rq); |
f26f9aff MG |
4436 | clear_tsk_need_resched(prev); |
4437 | rq->skip_clock_update = 0; | |
1da177e4 | 4438 | |
1da177e4 | 4439 | if (likely(prev != next)) { |
1da177e4 LT |
4440 | rq->nr_switches++; |
4441 | rq->curr = next; | |
4442 | ++*switch_count; | |
4443 | ||
dd41f596 | 4444 | context_switch(rq, prev, next); /* unlocks the rq */ |
8f4d37ec | 4445 | /* |
246d86b5 ON |
4446 | * The context switch have flipped the stack from under us |
4447 | * and restored the local variables which were saved when | |
4448 | * this task called schedule() in the past. prev == current | |
4449 | * is still correct, but it can be moved to another cpu/rq. | |
8f4d37ec PZ |
4450 | */ |
4451 | cpu = smp_processor_id(); | |
4452 | rq = cpu_rq(cpu); | |
1da177e4 | 4453 | } else |
05fa785c | 4454 | raw_spin_unlock_irq(&rq->lock); |
1da177e4 | 4455 | |
3f029d3c | 4456 | post_schedule(rq); |
1da177e4 | 4457 | |
1da177e4 | 4458 | preempt_enable_no_resched(); |
ff743345 | 4459 | if (need_resched()) |
1da177e4 LT |
4460 | goto need_resched; |
4461 | } | |
c259e01a | 4462 | |
9c40cef2 TG |
4463 | static inline void sched_submit_work(struct task_struct *tsk) |
4464 | { | |
4465 | if (!tsk->state) | |
4466 | return; | |
4467 | /* | |
4468 | * If we are going to sleep and we have plugged IO queued, | |
4469 | * make sure to submit it to avoid deadlocks. | |
4470 | */ | |
4471 | if (blk_needs_flush_plug(tsk)) | |
4472 | blk_schedule_flush_plug(tsk); | |
4473 | } | |
4474 | ||
6ebbe7a0 | 4475 | asmlinkage void __sched schedule(void) |
c259e01a | 4476 | { |
9c40cef2 TG |
4477 | struct task_struct *tsk = current; |
4478 | ||
4479 | sched_submit_work(tsk); | |
c259e01a TG |
4480 | __schedule(); |
4481 | } | |
1da177e4 LT |
4482 | EXPORT_SYMBOL(schedule); |
4483 | ||
c08f7829 | 4484 | #ifdef CONFIG_MUTEX_SPIN_ON_OWNER |
0d66bf6d | 4485 | |
c6eb3dda PZ |
4486 | static inline bool owner_running(struct mutex *lock, struct task_struct *owner) |
4487 | { | |
c6eb3dda | 4488 | if (lock->owner != owner) |
307bf980 | 4489 | return false; |
0d66bf6d PZ |
4490 | |
4491 | /* | |
c6eb3dda PZ |
4492 | * Ensure we emit the owner->on_cpu, dereference _after_ checking |
4493 | * lock->owner still matches owner, if that fails, owner might | |
4494 | * point to free()d memory, if it still matches, the rcu_read_lock() | |
4495 | * ensures the memory stays valid. | |
0d66bf6d | 4496 | */ |
c6eb3dda | 4497 | barrier(); |
0d66bf6d | 4498 | |
307bf980 | 4499 | return owner->on_cpu; |
c6eb3dda | 4500 | } |
0d66bf6d | 4501 | |
c6eb3dda PZ |
4502 | /* |
4503 | * Look out! "owner" is an entirely speculative pointer | |
4504 | * access and not reliable. | |
4505 | */ | |
4506 | int mutex_spin_on_owner(struct mutex *lock, struct task_struct *owner) | |
4507 | { | |
4508 | if (!sched_feat(OWNER_SPIN)) | |
4509 | return 0; | |
0d66bf6d | 4510 | |
307bf980 | 4511 | rcu_read_lock(); |
c6eb3dda PZ |
4512 | while (owner_running(lock, owner)) { |
4513 | if (need_resched()) | |
307bf980 | 4514 | break; |
0d66bf6d | 4515 | |
335d7afb | 4516 | arch_mutex_cpu_relax(); |
0d66bf6d | 4517 | } |
307bf980 | 4518 | rcu_read_unlock(); |
4b402210 | 4519 | |
c6eb3dda | 4520 | /* |
307bf980 TG |
4521 | * We break out the loop above on need_resched() and when the |
4522 | * owner changed, which is a sign for heavy contention. Return | |
4523 | * success only when lock->owner is NULL. | |
c6eb3dda | 4524 | */ |
307bf980 | 4525 | return lock->owner == NULL; |
0d66bf6d PZ |
4526 | } |
4527 | #endif | |
4528 | ||
1da177e4 LT |
4529 | #ifdef CONFIG_PREEMPT |
4530 | /* | |
2ed6e34f | 4531 | * this is the entry point to schedule() from in-kernel preemption |
41a2d6cf | 4532 | * off of preempt_enable. Kernel preemptions off return from interrupt |
1da177e4 LT |
4533 | * occur there and call schedule directly. |
4534 | */ | |
d1f74e20 | 4535 | asmlinkage void __sched notrace preempt_schedule(void) |
1da177e4 LT |
4536 | { |
4537 | struct thread_info *ti = current_thread_info(); | |
6478d880 | 4538 | |
1da177e4 LT |
4539 | /* |
4540 | * If there is a non-zero preempt_count or interrupts are disabled, | |
41a2d6cf | 4541 | * we do not want to preempt the current task. Just return.. |
1da177e4 | 4542 | */ |
beed33a8 | 4543 | if (likely(ti->preempt_count || irqs_disabled())) |
1da177e4 LT |
4544 | return; |
4545 | ||
3a5c359a | 4546 | do { |
d1f74e20 | 4547 | add_preempt_count_notrace(PREEMPT_ACTIVE); |
c259e01a | 4548 | __schedule(); |
d1f74e20 | 4549 | sub_preempt_count_notrace(PREEMPT_ACTIVE); |
1da177e4 | 4550 | |
3a5c359a AK |
4551 | /* |
4552 | * Check again in case we missed a preemption opportunity | |
4553 | * between schedule and now. | |
4554 | */ | |
4555 | barrier(); | |
5ed0cec0 | 4556 | } while (need_resched()); |
1da177e4 | 4557 | } |
1da177e4 LT |
4558 | EXPORT_SYMBOL(preempt_schedule); |
4559 | ||
4560 | /* | |
2ed6e34f | 4561 | * this is the entry point to schedule() from kernel preemption |
1da177e4 LT |
4562 | * off of irq context. |
4563 | * Note, that this is called and return with irqs disabled. This will | |
4564 | * protect us against recursive calling from irq. | |
4565 | */ | |
4566 | asmlinkage void __sched preempt_schedule_irq(void) | |
4567 | { | |
4568 | struct thread_info *ti = current_thread_info(); | |
6478d880 | 4569 | |
2ed6e34f | 4570 | /* Catch callers which need to be fixed */ |
1da177e4 LT |
4571 | BUG_ON(ti->preempt_count || !irqs_disabled()); |
4572 | ||
3a5c359a AK |
4573 | do { |
4574 | add_preempt_count(PREEMPT_ACTIVE); | |
3a5c359a | 4575 | local_irq_enable(); |
c259e01a | 4576 | __schedule(); |
3a5c359a | 4577 | local_irq_disable(); |
3a5c359a | 4578 | sub_preempt_count(PREEMPT_ACTIVE); |
1da177e4 | 4579 | |
3a5c359a AK |
4580 | /* |
4581 | * Check again in case we missed a preemption opportunity | |
4582 | * between schedule and now. | |
4583 | */ | |
4584 | barrier(); | |
5ed0cec0 | 4585 | } while (need_resched()); |
1da177e4 LT |
4586 | } |
4587 | ||
4588 | #endif /* CONFIG_PREEMPT */ | |
4589 | ||
63859d4f | 4590 | int default_wake_function(wait_queue_t *curr, unsigned mode, int wake_flags, |
95cdf3b7 | 4591 | void *key) |
1da177e4 | 4592 | { |
63859d4f | 4593 | return try_to_wake_up(curr->private, mode, wake_flags); |
1da177e4 | 4594 | } |
1da177e4 LT |
4595 | EXPORT_SYMBOL(default_wake_function); |
4596 | ||
4597 | /* | |
41a2d6cf IM |
4598 | * The core wakeup function. Non-exclusive wakeups (nr_exclusive == 0) just |
4599 | * wake everything up. If it's an exclusive wakeup (nr_exclusive == small +ve | |
1da177e4 LT |
4600 | * number) then we wake all the non-exclusive tasks and one exclusive task. |
4601 | * | |
4602 | * There are circumstances in which we can try to wake a task which has already | |
41a2d6cf | 4603 | * started to run but is not in state TASK_RUNNING. try_to_wake_up() returns |
1da177e4 LT |
4604 | * zero in this (rare) case, and we handle it by continuing to scan the queue. |
4605 | */ | |
78ddb08f | 4606 | static void __wake_up_common(wait_queue_head_t *q, unsigned int mode, |
63859d4f | 4607 | int nr_exclusive, int wake_flags, void *key) |
1da177e4 | 4608 | { |
2e45874c | 4609 | wait_queue_t *curr, *next; |
1da177e4 | 4610 | |
2e45874c | 4611 | list_for_each_entry_safe(curr, next, &q->task_list, task_list) { |
48f24c4d IM |
4612 | unsigned flags = curr->flags; |
4613 | ||
63859d4f | 4614 | if (curr->func(curr, mode, wake_flags, key) && |
48f24c4d | 4615 | (flags & WQ_FLAG_EXCLUSIVE) && !--nr_exclusive) |
1da177e4 LT |
4616 | break; |
4617 | } | |
4618 | } | |
4619 | ||
4620 | /** | |
4621 | * __wake_up - wake up threads blocked on a waitqueue. | |
4622 | * @q: the waitqueue | |
4623 | * @mode: which threads | |
4624 | * @nr_exclusive: how many wake-one or wake-many threads to wake up | |
67be2dd1 | 4625 | * @key: is directly passed to the wakeup function |
50fa610a DH |
4626 | * |
4627 | * It may be assumed that this function implies a write memory barrier before | |
4628 | * changing the task state if and only if any tasks are woken up. | |
1da177e4 | 4629 | */ |
7ad5b3a5 | 4630 | void __wake_up(wait_queue_head_t *q, unsigned int mode, |
95cdf3b7 | 4631 | int nr_exclusive, void *key) |
1da177e4 LT |
4632 | { |
4633 | unsigned long flags; | |
4634 | ||
4635 | spin_lock_irqsave(&q->lock, flags); | |
4636 | __wake_up_common(q, mode, nr_exclusive, 0, key); | |
4637 | spin_unlock_irqrestore(&q->lock, flags); | |
4638 | } | |
1da177e4 LT |
4639 | EXPORT_SYMBOL(__wake_up); |
4640 | ||
4641 | /* | |
4642 | * Same as __wake_up but called with the spinlock in wait_queue_head_t held. | |
4643 | */ | |
7ad5b3a5 | 4644 | void __wake_up_locked(wait_queue_head_t *q, unsigned int mode) |
1da177e4 LT |
4645 | { |
4646 | __wake_up_common(q, mode, 1, 0, NULL); | |
4647 | } | |
22c43c81 | 4648 | EXPORT_SYMBOL_GPL(__wake_up_locked); |
1da177e4 | 4649 | |
4ede816a DL |
4650 | void __wake_up_locked_key(wait_queue_head_t *q, unsigned int mode, void *key) |
4651 | { | |
4652 | __wake_up_common(q, mode, 1, 0, key); | |
4653 | } | |
bf294b41 | 4654 | EXPORT_SYMBOL_GPL(__wake_up_locked_key); |
4ede816a | 4655 | |
1da177e4 | 4656 | /** |
4ede816a | 4657 | * __wake_up_sync_key - wake up threads blocked on a waitqueue. |
1da177e4 LT |
4658 | * @q: the waitqueue |
4659 | * @mode: which threads | |
4660 | * @nr_exclusive: how many wake-one or wake-many threads to wake up | |
4ede816a | 4661 | * @key: opaque value to be passed to wakeup targets |
1da177e4 LT |
4662 | * |
4663 | * The sync wakeup differs that the waker knows that it will schedule | |
4664 | * away soon, so while the target thread will be woken up, it will not | |
4665 | * be migrated to another CPU - ie. the two threads are 'synchronized' | |
4666 | * with each other. This can prevent needless bouncing between CPUs. | |
4667 | * | |
4668 | * On UP it can prevent extra preemption. | |
50fa610a DH |
4669 | * |
4670 | * It may be assumed that this function implies a write memory barrier before | |
4671 | * changing the task state if and only if any tasks are woken up. | |
1da177e4 | 4672 | */ |
4ede816a DL |
4673 | void __wake_up_sync_key(wait_queue_head_t *q, unsigned int mode, |
4674 | int nr_exclusive, void *key) | |
1da177e4 LT |
4675 | { |
4676 | unsigned long flags; | |
7d478721 | 4677 | int wake_flags = WF_SYNC; |
1da177e4 LT |
4678 | |
4679 | if (unlikely(!q)) | |
4680 | return; | |
4681 | ||
4682 | if (unlikely(!nr_exclusive)) | |
7d478721 | 4683 | wake_flags = 0; |
1da177e4 LT |
4684 | |
4685 | spin_lock_irqsave(&q->lock, flags); | |
7d478721 | 4686 | __wake_up_common(q, mode, nr_exclusive, wake_flags, key); |
1da177e4 LT |
4687 | spin_unlock_irqrestore(&q->lock, flags); |
4688 | } | |
4ede816a DL |
4689 | EXPORT_SYMBOL_GPL(__wake_up_sync_key); |
4690 | ||
4691 | /* | |
4692 | * __wake_up_sync - see __wake_up_sync_key() | |
4693 | */ | |
4694 | void __wake_up_sync(wait_queue_head_t *q, unsigned int mode, int nr_exclusive) | |
4695 | { | |
4696 | __wake_up_sync_key(q, mode, nr_exclusive, NULL); | |
4697 | } | |
1da177e4 LT |
4698 | EXPORT_SYMBOL_GPL(__wake_up_sync); /* For internal use only */ |
4699 | ||
65eb3dc6 KD |
4700 | /** |
4701 | * complete: - signals a single thread waiting on this completion | |
4702 | * @x: holds the state of this particular completion | |
4703 | * | |
4704 | * This will wake up a single thread waiting on this completion. Threads will be | |
4705 | * awakened in the same order in which they were queued. | |
4706 | * | |
4707 | * See also complete_all(), wait_for_completion() and related routines. | |
50fa610a DH |
4708 | * |
4709 | * It may be assumed that this function implies a write memory barrier before | |
4710 | * changing the task state if and only if any tasks are woken up. | |
65eb3dc6 | 4711 | */ |
b15136e9 | 4712 | void complete(struct completion *x) |
1da177e4 LT |
4713 | { |
4714 | unsigned long flags; | |
4715 | ||
4716 | spin_lock_irqsave(&x->wait.lock, flags); | |
4717 | x->done++; | |
d9514f6c | 4718 | __wake_up_common(&x->wait, TASK_NORMAL, 1, 0, NULL); |
1da177e4 LT |
4719 | spin_unlock_irqrestore(&x->wait.lock, flags); |
4720 | } | |
4721 | EXPORT_SYMBOL(complete); | |
4722 | ||
65eb3dc6 KD |
4723 | /** |
4724 | * complete_all: - signals all threads waiting on this completion | |
4725 | * @x: holds the state of this particular completion | |
4726 | * | |
4727 | * This will wake up all threads waiting on this particular completion event. | |
50fa610a DH |
4728 | * |
4729 | * It may be assumed that this function implies a write memory barrier before | |
4730 | * changing the task state if and only if any tasks are woken up. | |
65eb3dc6 | 4731 | */ |
b15136e9 | 4732 | void complete_all(struct completion *x) |
1da177e4 LT |
4733 | { |
4734 | unsigned long flags; | |
4735 | ||
4736 | spin_lock_irqsave(&x->wait.lock, flags); | |
4737 | x->done += UINT_MAX/2; | |
d9514f6c | 4738 | __wake_up_common(&x->wait, TASK_NORMAL, 0, 0, NULL); |
1da177e4 LT |
4739 | spin_unlock_irqrestore(&x->wait.lock, flags); |
4740 | } | |
4741 | EXPORT_SYMBOL(complete_all); | |
4742 | ||
8cbbe86d AK |
4743 | static inline long __sched |
4744 | do_wait_for_common(struct completion *x, long timeout, int state) | |
1da177e4 | 4745 | { |
1da177e4 LT |
4746 | if (!x->done) { |
4747 | DECLARE_WAITQUEUE(wait, current); | |
4748 | ||
a93d2f17 | 4749 | __add_wait_queue_tail_exclusive(&x->wait, &wait); |
1da177e4 | 4750 | do { |
94d3d824 | 4751 | if (signal_pending_state(state, current)) { |
ea71a546 ON |
4752 | timeout = -ERESTARTSYS; |
4753 | break; | |
8cbbe86d AK |
4754 | } |
4755 | __set_current_state(state); | |
1da177e4 LT |
4756 | spin_unlock_irq(&x->wait.lock); |
4757 | timeout = schedule_timeout(timeout); | |
4758 | spin_lock_irq(&x->wait.lock); | |
ea71a546 | 4759 | } while (!x->done && timeout); |
1da177e4 | 4760 | __remove_wait_queue(&x->wait, &wait); |
ea71a546 ON |
4761 | if (!x->done) |
4762 | return timeout; | |
1da177e4 LT |
4763 | } |
4764 | x->done--; | |
ea71a546 | 4765 | return timeout ?: 1; |
1da177e4 | 4766 | } |
1da177e4 | 4767 | |
8cbbe86d AK |
4768 | static long __sched |
4769 | wait_for_common(struct completion *x, long timeout, int state) | |
1da177e4 | 4770 | { |
1da177e4 LT |
4771 | might_sleep(); |
4772 | ||
4773 | spin_lock_irq(&x->wait.lock); | |
8cbbe86d | 4774 | timeout = do_wait_for_common(x, timeout, state); |
1da177e4 | 4775 | spin_unlock_irq(&x->wait.lock); |
8cbbe86d AK |
4776 | return timeout; |
4777 | } | |
1da177e4 | 4778 | |
65eb3dc6 KD |
4779 | /** |
4780 | * wait_for_completion: - waits for completion of a task | |
4781 | * @x: holds the state of this particular completion | |
4782 | * | |
4783 | * This waits to be signaled for completion of a specific task. It is NOT | |
4784 | * interruptible and there is no timeout. | |
4785 | * | |
4786 | * See also similar routines (i.e. wait_for_completion_timeout()) with timeout | |
4787 | * and interrupt capability. Also see complete(). | |
4788 | */ | |
b15136e9 | 4789 | void __sched wait_for_completion(struct completion *x) |
8cbbe86d AK |
4790 | { |
4791 | wait_for_common(x, MAX_SCHEDULE_TIMEOUT, TASK_UNINTERRUPTIBLE); | |
1da177e4 | 4792 | } |
8cbbe86d | 4793 | EXPORT_SYMBOL(wait_for_completion); |
1da177e4 | 4794 | |
65eb3dc6 KD |
4795 | /** |
4796 | * wait_for_completion_timeout: - waits for completion of a task (w/timeout) | |
4797 | * @x: holds the state of this particular completion | |
4798 | * @timeout: timeout value in jiffies | |
4799 | * | |
4800 | * This waits for either a completion of a specific task to be signaled or for a | |
4801 | * specified timeout to expire. The timeout is in jiffies. It is not | |
4802 | * interruptible. | |
c6dc7f05 BF |
4803 | * |
4804 | * The return value is 0 if timed out, and positive (at least 1, or number of | |
4805 | * jiffies left till timeout) if completed. | |
65eb3dc6 | 4806 | */ |
b15136e9 | 4807 | unsigned long __sched |
8cbbe86d | 4808 | wait_for_completion_timeout(struct completion *x, unsigned long timeout) |
1da177e4 | 4809 | { |
8cbbe86d | 4810 | return wait_for_common(x, timeout, TASK_UNINTERRUPTIBLE); |
1da177e4 | 4811 | } |
8cbbe86d | 4812 | EXPORT_SYMBOL(wait_for_completion_timeout); |
1da177e4 | 4813 | |
65eb3dc6 KD |
4814 | /** |
4815 | * wait_for_completion_interruptible: - waits for completion of a task (w/intr) | |
4816 | * @x: holds the state of this particular completion | |
4817 | * | |
4818 | * This waits for completion of a specific task to be signaled. It is | |
4819 | * interruptible. | |
c6dc7f05 BF |
4820 | * |
4821 | * The return value is -ERESTARTSYS if interrupted, 0 if completed. | |
65eb3dc6 | 4822 | */ |
8cbbe86d | 4823 | int __sched wait_for_completion_interruptible(struct completion *x) |
0fec171c | 4824 | { |
51e97990 AK |
4825 | long t = wait_for_common(x, MAX_SCHEDULE_TIMEOUT, TASK_INTERRUPTIBLE); |
4826 | if (t == -ERESTARTSYS) | |
4827 | return t; | |
4828 | return 0; | |
0fec171c | 4829 | } |
8cbbe86d | 4830 | EXPORT_SYMBOL(wait_for_completion_interruptible); |
1da177e4 | 4831 | |
65eb3dc6 KD |
4832 | /** |
4833 | * wait_for_completion_interruptible_timeout: - waits for completion (w/(to,intr)) | |
4834 | * @x: holds the state of this particular completion | |
4835 | * @timeout: timeout value in jiffies | |
4836 | * | |
4837 | * This waits for either a completion of a specific task to be signaled or for a | |
4838 | * specified timeout to expire. It is interruptible. The timeout is in jiffies. | |
c6dc7f05 BF |
4839 | * |
4840 | * The return value is -ERESTARTSYS if interrupted, 0 if timed out, | |
4841 | * positive (at least 1, or number of jiffies left till timeout) if completed. | |
65eb3dc6 | 4842 | */ |
6bf41237 | 4843 | long __sched |
8cbbe86d AK |
4844 | wait_for_completion_interruptible_timeout(struct completion *x, |
4845 | unsigned long timeout) | |
0fec171c | 4846 | { |
8cbbe86d | 4847 | return wait_for_common(x, timeout, TASK_INTERRUPTIBLE); |
0fec171c | 4848 | } |
8cbbe86d | 4849 | EXPORT_SYMBOL(wait_for_completion_interruptible_timeout); |
1da177e4 | 4850 | |
65eb3dc6 KD |
4851 | /** |
4852 | * wait_for_completion_killable: - waits for completion of a task (killable) | |
4853 | * @x: holds the state of this particular completion | |
4854 | * | |
4855 | * This waits to be signaled for completion of a specific task. It can be | |
4856 | * interrupted by a kill signal. | |
c6dc7f05 BF |
4857 | * |
4858 | * The return value is -ERESTARTSYS if interrupted, 0 if completed. | |
65eb3dc6 | 4859 | */ |
009e577e MW |
4860 | int __sched wait_for_completion_killable(struct completion *x) |
4861 | { | |
4862 | long t = wait_for_common(x, MAX_SCHEDULE_TIMEOUT, TASK_KILLABLE); | |
4863 | if (t == -ERESTARTSYS) | |
4864 | return t; | |
4865 | return 0; | |
4866 | } | |
4867 | EXPORT_SYMBOL(wait_for_completion_killable); | |
4868 | ||
0aa12fb4 SW |
4869 | /** |
4870 | * wait_for_completion_killable_timeout: - waits for completion of a task (w/(to,killable)) | |
4871 | * @x: holds the state of this particular completion | |
4872 | * @timeout: timeout value in jiffies | |
4873 | * | |
4874 | * This waits for either a completion of a specific task to be | |
4875 | * signaled or for a specified timeout to expire. It can be | |
4876 | * interrupted by a kill signal. The timeout is in jiffies. | |
c6dc7f05 BF |
4877 | * |
4878 | * The return value is -ERESTARTSYS if interrupted, 0 if timed out, | |
4879 | * positive (at least 1, or number of jiffies left till timeout) if completed. | |
0aa12fb4 | 4880 | */ |
6bf41237 | 4881 | long __sched |
0aa12fb4 SW |
4882 | wait_for_completion_killable_timeout(struct completion *x, |
4883 | unsigned long timeout) | |
4884 | { | |
4885 | return wait_for_common(x, timeout, TASK_KILLABLE); | |
4886 | } | |
4887 | EXPORT_SYMBOL(wait_for_completion_killable_timeout); | |
4888 | ||
be4de352 DC |
4889 | /** |
4890 | * try_wait_for_completion - try to decrement a completion without blocking | |
4891 | * @x: completion structure | |
4892 | * | |
4893 | * Returns: 0 if a decrement cannot be done without blocking | |
4894 | * 1 if a decrement succeeded. | |
4895 | * | |
4896 | * If a completion is being used as a counting completion, | |
4897 | * attempt to decrement the counter without blocking. This | |
4898 | * enables us to avoid waiting if the resource the completion | |
4899 | * is protecting is not available. | |
4900 | */ | |
4901 | bool try_wait_for_completion(struct completion *x) | |
4902 | { | |
7539a3b3 | 4903 | unsigned long flags; |
be4de352 DC |
4904 | int ret = 1; |
4905 | ||
7539a3b3 | 4906 | spin_lock_irqsave(&x->wait.lock, flags); |
be4de352 DC |
4907 | if (!x->done) |
4908 | ret = 0; | |
4909 | else | |
4910 | x->done--; | |
7539a3b3 | 4911 | spin_unlock_irqrestore(&x->wait.lock, flags); |
be4de352 DC |
4912 | return ret; |
4913 | } | |
4914 | EXPORT_SYMBOL(try_wait_for_completion); | |
4915 | ||
4916 | /** | |
4917 | * completion_done - Test to see if a completion has any waiters | |
4918 | * @x: completion structure | |
4919 | * | |
4920 | * Returns: 0 if there are waiters (wait_for_completion() in progress) | |
4921 | * 1 if there are no waiters. | |
4922 | * | |
4923 | */ | |
4924 | bool completion_done(struct completion *x) | |
4925 | { | |
7539a3b3 | 4926 | unsigned long flags; |
be4de352 DC |
4927 | int ret = 1; |
4928 | ||
7539a3b3 | 4929 | spin_lock_irqsave(&x->wait.lock, flags); |
be4de352 DC |
4930 | if (!x->done) |
4931 | ret = 0; | |
7539a3b3 | 4932 | spin_unlock_irqrestore(&x->wait.lock, flags); |
be4de352 DC |
4933 | return ret; |
4934 | } | |
4935 | EXPORT_SYMBOL(completion_done); | |
4936 | ||
8cbbe86d AK |
4937 | static long __sched |
4938 | sleep_on_common(wait_queue_head_t *q, int state, long timeout) | |
1da177e4 | 4939 | { |
0fec171c IM |
4940 | unsigned long flags; |
4941 | wait_queue_t wait; | |
4942 | ||
4943 | init_waitqueue_entry(&wait, current); | |
1da177e4 | 4944 | |
8cbbe86d | 4945 | __set_current_state(state); |
1da177e4 | 4946 | |
8cbbe86d AK |
4947 | spin_lock_irqsave(&q->lock, flags); |
4948 | __add_wait_queue(q, &wait); | |
4949 | spin_unlock(&q->lock); | |
4950 | timeout = schedule_timeout(timeout); | |
4951 | spin_lock_irq(&q->lock); | |
4952 | __remove_wait_queue(q, &wait); | |
4953 | spin_unlock_irqrestore(&q->lock, flags); | |
4954 | ||
4955 | return timeout; | |
4956 | } | |
4957 | ||
4958 | void __sched interruptible_sleep_on(wait_queue_head_t *q) | |
4959 | { | |
4960 | sleep_on_common(q, TASK_INTERRUPTIBLE, MAX_SCHEDULE_TIMEOUT); | |
1da177e4 | 4961 | } |
1da177e4 LT |
4962 | EXPORT_SYMBOL(interruptible_sleep_on); |
4963 | ||
0fec171c | 4964 | long __sched |
95cdf3b7 | 4965 | interruptible_sleep_on_timeout(wait_queue_head_t *q, long timeout) |
1da177e4 | 4966 | { |
8cbbe86d | 4967 | return sleep_on_common(q, TASK_INTERRUPTIBLE, timeout); |
1da177e4 | 4968 | } |
1da177e4 LT |
4969 | EXPORT_SYMBOL(interruptible_sleep_on_timeout); |
4970 | ||
0fec171c | 4971 | void __sched sleep_on(wait_queue_head_t *q) |
1da177e4 | 4972 | { |
8cbbe86d | 4973 | sleep_on_common(q, TASK_UNINTERRUPTIBLE, MAX_SCHEDULE_TIMEOUT); |
1da177e4 | 4974 | } |
1da177e4 LT |
4975 | EXPORT_SYMBOL(sleep_on); |
4976 | ||
0fec171c | 4977 | long __sched sleep_on_timeout(wait_queue_head_t *q, long timeout) |
1da177e4 | 4978 | { |
8cbbe86d | 4979 | return sleep_on_common(q, TASK_UNINTERRUPTIBLE, timeout); |
1da177e4 | 4980 | } |
1da177e4 LT |
4981 | EXPORT_SYMBOL(sleep_on_timeout); |
4982 | ||
b29739f9 IM |
4983 | #ifdef CONFIG_RT_MUTEXES |
4984 | ||
4985 | /* | |
4986 | * rt_mutex_setprio - set the current priority of a task | |
4987 | * @p: task | |
4988 | * @prio: prio value (kernel-internal form) | |
4989 | * | |
4990 | * This function changes the 'effective' priority of a task. It does | |
4991 | * not touch ->normal_prio like __setscheduler(). | |
4992 | * | |
4993 | * Used by the rt_mutex code to implement priority inheritance logic. | |
4994 | */ | |
36c8b586 | 4995 | void rt_mutex_setprio(struct task_struct *p, int prio) |
b29739f9 | 4996 | { |
83b699ed | 4997 | int oldprio, on_rq, running; |
70b97a7f | 4998 | struct rq *rq; |
83ab0aa0 | 4999 | const struct sched_class *prev_class; |
b29739f9 IM |
5000 | |
5001 | BUG_ON(prio < 0 || prio > MAX_PRIO); | |
5002 | ||
0122ec5b | 5003 | rq = __task_rq_lock(p); |
b29739f9 | 5004 | |
a8027073 | 5005 | trace_sched_pi_setprio(p, prio); |
d5f9f942 | 5006 | oldprio = p->prio; |
83ab0aa0 | 5007 | prev_class = p->sched_class; |
fd2f4419 | 5008 | on_rq = p->on_rq; |
051a1d1a | 5009 | running = task_current(rq, p); |
0e1f3483 | 5010 | if (on_rq) |
69be72c1 | 5011 | dequeue_task(rq, p, 0); |
0e1f3483 HS |
5012 | if (running) |
5013 | p->sched_class->put_prev_task(rq, p); | |
dd41f596 IM |
5014 | |
5015 | if (rt_prio(prio)) | |
5016 | p->sched_class = &rt_sched_class; | |
5017 | else | |
5018 | p->sched_class = &fair_sched_class; | |
5019 | ||
b29739f9 IM |
5020 | p->prio = prio; |
5021 | ||
0e1f3483 HS |
5022 | if (running) |
5023 | p->sched_class->set_curr_task(rq); | |
da7a735e | 5024 | if (on_rq) |
371fd7e7 | 5025 | enqueue_task(rq, p, oldprio < prio ? ENQUEUE_HEAD : 0); |
cb469845 | 5026 | |
da7a735e | 5027 | check_class_changed(rq, p, prev_class, oldprio); |
0122ec5b | 5028 | __task_rq_unlock(rq); |
b29739f9 IM |
5029 | } |
5030 | ||
5031 | #endif | |
5032 | ||
36c8b586 | 5033 | void set_user_nice(struct task_struct *p, long nice) |
1da177e4 | 5034 | { |
dd41f596 | 5035 | int old_prio, delta, on_rq; |
1da177e4 | 5036 | unsigned long flags; |
70b97a7f | 5037 | struct rq *rq; |
1da177e4 LT |
5038 | |
5039 | if (TASK_NICE(p) == nice || nice < -20 || nice > 19) | |
5040 | return; | |
5041 | /* | |
5042 | * We have to be careful, if called from sys_setpriority(), | |
5043 | * the task might be in the middle of scheduling on another CPU. | |
5044 | */ | |
5045 | rq = task_rq_lock(p, &flags); | |
5046 | /* | |
5047 | * The RT priorities are set via sched_setscheduler(), but we still | |
5048 | * allow the 'normal' nice value to be set - but as expected | |
5049 | * it wont have any effect on scheduling until the task is | |
dd41f596 | 5050 | * SCHED_FIFO/SCHED_RR: |
1da177e4 | 5051 | */ |
e05606d3 | 5052 | if (task_has_rt_policy(p)) { |
1da177e4 LT |
5053 | p->static_prio = NICE_TO_PRIO(nice); |
5054 | goto out_unlock; | |
5055 | } | |
fd2f4419 | 5056 | on_rq = p->on_rq; |
c09595f6 | 5057 | if (on_rq) |
69be72c1 | 5058 | dequeue_task(rq, p, 0); |
1da177e4 | 5059 | |
1da177e4 | 5060 | p->static_prio = NICE_TO_PRIO(nice); |
2dd73a4f | 5061 | set_load_weight(p); |
b29739f9 IM |
5062 | old_prio = p->prio; |
5063 | p->prio = effective_prio(p); | |
5064 | delta = p->prio - old_prio; | |
1da177e4 | 5065 | |
dd41f596 | 5066 | if (on_rq) { |
371fd7e7 | 5067 | enqueue_task(rq, p, 0); |
1da177e4 | 5068 | /* |
d5f9f942 AM |
5069 | * If the task increased its priority or is running and |
5070 | * lowered its priority, then reschedule its CPU: | |
1da177e4 | 5071 | */ |
d5f9f942 | 5072 | if (delta < 0 || (delta > 0 && task_running(rq, p))) |
1da177e4 LT |
5073 | resched_task(rq->curr); |
5074 | } | |
5075 | out_unlock: | |
0122ec5b | 5076 | task_rq_unlock(rq, p, &flags); |
1da177e4 | 5077 | } |
1da177e4 LT |
5078 | EXPORT_SYMBOL(set_user_nice); |
5079 | ||
e43379f1 MM |
5080 | /* |
5081 | * can_nice - check if a task can reduce its nice value | |
5082 | * @p: task | |
5083 | * @nice: nice value | |
5084 | */ | |
36c8b586 | 5085 | int can_nice(const struct task_struct *p, const int nice) |
e43379f1 | 5086 | { |
024f4747 MM |
5087 | /* convert nice value [19,-20] to rlimit style value [1,40] */ |
5088 | int nice_rlim = 20 - nice; | |
48f24c4d | 5089 | |
78d7d407 | 5090 | return (nice_rlim <= task_rlimit(p, RLIMIT_NICE) || |
e43379f1 MM |
5091 | capable(CAP_SYS_NICE)); |
5092 | } | |
5093 | ||
1da177e4 LT |
5094 | #ifdef __ARCH_WANT_SYS_NICE |
5095 | ||
5096 | /* | |
5097 | * sys_nice - change the priority of the current process. | |
5098 | * @increment: priority increment | |
5099 | * | |
5100 | * sys_setpriority is a more generic, but much slower function that | |
5101 | * does similar things. | |
5102 | */ | |
5add95d4 | 5103 | SYSCALL_DEFINE1(nice, int, increment) |
1da177e4 | 5104 | { |
48f24c4d | 5105 | long nice, retval; |
1da177e4 LT |
5106 | |
5107 | /* | |
5108 | * Setpriority might change our priority at the same moment. | |
5109 | * We don't have to worry. Conceptually one call occurs first | |
5110 | * and we have a single winner. | |
5111 | */ | |
e43379f1 MM |
5112 | if (increment < -40) |
5113 | increment = -40; | |
1da177e4 LT |
5114 | if (increment > 40) |
5115 | increment = 40; | |
5116 | ||
2b8f836f | 5117 | nice = TASK_NICE(current) + increment; |
1da177e4 LT |
5118 | if (nice < -20) |
5119 | nice = -20; | |
5120 | if (nice > 19) | |
5121 | nice = 19; | |
5122 | ||
e43379f1 MM |
5123 | if (increment < 0 && !can_nice(current, nice)) |
5124 | return -EPERM; | |
5125 | ||
1da177e4 LT |
5126 | retval = security_task_setnice(current, nice); |
5127 | if (retval) | |
5128 | return retval; | |
5129 | ||
5130 | set_user_nice(current, nice); | |
5131 | return 0; | |
5132 | } | |
5133 | ||
5134 | #endif | |
5135 | ||
5136 | /** | |
5137 | * task_prio - return the priority value of a given task. | |
5138 | * @p: the task in question. | |
5139 | * | |
5140 | * This is the priority value as seen by users in /proc. | |
5141 | * RT tasks are offset by -200. Normal tasks are centered | |
5142 | * around 0, value goes from -16 to +15. | |
5143 | */ | |
36c8b586 | 5144 | int task_prio(const struct task_struct *p) |
1da177e4 LT |
5145 | { |
5146 | return p->prio - MAX_RT_PRIO; | |
5147 | } | |
5148 | ||
5149 | /** | |
5150 | * task_nice - return the nice value of a given task. | |
5151 | * @p: the task in question. | |
5152 | */ | |
36c8b586 | 5153 | int task_nice(const struct task_struct *p) |
1da177e4 LT |
5154 | { |
5155 | return TASK_NICE(p); | |
5156 | } | |
150d8bed | 5157 | EXPORT_SYMBOL(task_nice); |
1da177e4 LT |
5158 | |
5159 | /** | |
5160 | * idle_cpu - is a given cpu idle currently? | |
5161 | * @cpu: the processor in question. | |
5162 | */ | |
5163 | int idle_cpu(int cpu) | |
5164 | { | |
908a3283 TG |
5165 | struct rq *rq = cpu_rq(cpu); |
5166 | ||
5167 | if (rq->curr != rq->idle) | |
5168 | return 0; | |
5169 | ||
5170 | if (rq->nr_running) | |
5171 | return 0; | |
5172 | ||
5173 | #ifdef CONFIG_SMP | |
5174 | if (!llist_empty(&rq->wake_list)) | |
5175 | return 0; | |
5176 | #endif | |
5177 | ||
5178 | return 1; | |
1da177e4 LT |
5179 | } |
5180 | ||
1da177e4 LT |
5181 | /** |
5182 | * idle_task - return the idle task for a given cpu. | |
5183 | * @cpu: the processor in question. | |
5184 | */ | |
36c8b586 | 5185 | struct task_struct *idle_task(int cpu) |
1da177e4 LT |
5186 | { |
5187 | return cpu_rq(cpu)->idle; | |
5188 | } | |
5189 | ||
5190 | /** | |
5191 | * find_process_by_pid - find a process with a matching PID value. | |
5192 | * @pid: the pid in question. | |
5193 | */ | |
a9957449 | 5194 | static struct task_struct *find_process_by_pid(pid_t pid) |
1da177e4 | 5195 | { |
228ebcbe | 5196 | return pid ? find_task_by_vpid(pid) : current; |
1da177e4 LT |
5197 | } |
5198 | ||
5199 | /* Actually do priority change: must hold rq lock. */ | |
dd41f596 IM |
5200 | static void |
5201 | __setscheduler(struct rq *rq, struct task_struct *p, int policy, int prio) | |
1da177e4 | 5202 | { |
1da177e4 LT |
5203 | p->policy = policy; |
5204 | p->rt_priority = prio; | |
b29739f9 IM |
5205 | p->normal_prio = normal_prio(p); |
5206 | /* we are holding p->pi_lock already */ | |
5207 | p->prio = rt_mutex_getprio(p); | |
ffd44db5 PZ |
5208 | if (rt_prio(p->prio)) |
5209 | p->sched_class = &rt_sched_class; | |
5210 | else | |
5211 | p->sched_class = &fair_sched_class; | |
2dd73a4f | 5212 | set_load_weight(p); |
1da177e4 LT |
5213 | } |
5214 | ||
c69e8d9c DH |
5215 | /* |
5216 | * check the target process has a UID that matches the current process's | |
5217 | */ | |
5218 | static bool check_same_owner(struct task_struct *p) | |
5219 | { | |
5220 | const struct cred *cred = current_cred(), *pcred; | |
5221 | bool match; | |
5222 | ||
5223 | rcu_read_lock(); | |
5224 | pcred = __task_cred(p); | |
b0e77598 SH |
5225 | if (cred->user->user_ns == pcred->user->user_ns) |
5226 | match = (cred->euid == pcred->euid || | |
5227 | cred->euid == pcred->uid); | |
5228 | else | |
5229 | match = false; | |
c69e8d9c DH |
5230 | rcu_read_unlock(); |
5231 | return match; | |
5232 | } | |
5233 | ||
961ccddd | 5234 | static int __sched_setscheduler(struct task_struct *p, int policy, |
fe7de49f | 5235 | const struct sched_param *param, bool user) |
1da177e4 | 5236 | { |
83b699ed | 5237 | int retval, oldprio, oldpolicy = -1, on_rq, running; |
1da177e4 | 5238 | unsigned long flags; |
83ab0aa0 | 5239 | const struct sched_class *prev_class; |
70b97a7f | 5240 | struct rq *rq; |
ca94c442 | 5241 | int reset_on_fork; |
1da177e4 | 5242 | |
66e5393a SR |
5243 | /* may grab non-irq protected spin_locks */ |
5244 | BUG_ON(in_interrupt()); | |
1da177e4 LT |
5245 | recheck: |
5246 | /* double check policy once rq lock held */ | |
ca94c442 LP |
5247 | if (policy < 0) { |
5248 | reset_on_fork = p->sched_reset_on_fork; | |
1da177e4 | 5249 | policy = oldpolicy = p->policy; |
ca94c442 LP |
5250 | } else { |
5251 | reset_on_fork = !!(policy & SCHED_RESET_ON_FORK); | |
5252 | policy &= ~SCHED_RESET_ON_FORK; | |
5253 | ||
5254 | if (policy != SCHED_FIFO && policy != SCHED_RR && | |
5255 | policy != SCHED_NORMAL && policy != SCHED_BATCH && | |
5256 | policy != SCHED_IDLE) | |
5257 | return -EINVAL; | |
5258 | } | |
5259 | ||
1da177e4 LT |
5260 | /* |
5261 | * Valid priorities for SCHED_FIFO and SCHED_RR are | |
dd41f596 IM |
5262 | * 1..MAX_USER_RT_PRIO-1, valid priority for SCHED_NORMAL, |
5263 | * SCHED_BATCH and SCHED_IDLE is 0. | |
1da177e4 LT |
5264 | */ |
5265 | if (param->sched_priority < 0 || | |
95cdf3b7 | 5266 | (p->mm && param->sched_priority > MAX_USER_RT_PRIO-1) || |
d46523ea | 5267 | (!p->mm && param->sched_priority > MAX_RT_PRIO-1)) |
1da177e4 | 5268 | return -EINVAL; |
e05606d3 | 5269 | if (rt_policy(policy) != (param->sched_priority != 0)) |
1da177e4 LT |
5270 | return -EINVAL; |
5271 | ||
37e4ab3f OC |
5272 | /* |
5273 | * Allow unprivileged RT tasks to decrease priority: | |
5274 | */ | |
961ccddd | 5275 | if (user && !capable(CAP_SYS_NICE)) { |
e05606d3 | 5276 | if (rt_policy(policy)) { |
a44702e8 ON |
5277 | unsigned long rlim_rtprio = |
5278 | task_rlimit(p, RLIMIT_RTPRIO); | |
8dc3e909 ON |
5279 | |
5280 | /* can't set/change the rt policy */ | |
5281 | if (policy != p->policy && !rlim_rtprio) | |
5282 | return -EPERM; | |
5283 | ||
5284 | /* can't increase priority */ | |
5285 | if (param->sched_priority > p->rt_priority && | |
5286 | param->sched_priority > rlim_rtprio) | |
5287 | return -EPERM; | |
5288 | } | |
c02aa73b | 5289 | |
dd41f596 | 5290 | /* |
c02aa73b DH |
5291 | * Treat SCHED_IDLE as nice 20. Only allow a switch to |
5292 | * SCHED_NORMAL if the RLIMIT_NICE would normally permit it. | |
dd41f596 | 5293 | */ |
c02aa73b DH |
5294 | if (p->policy == SCHED_IDLE && policy != SCHED_IDLE) { |
5295 | if (!can_nice(p, TASK_NICE(p))) | |
5296 | return -EPERM; | |
5297 | } | |
5fe1d75f | 5298 | |
37e4ab3f | 5299 | /* can't change other user's priorities */ |
c69e8d9c | 5300 | if (!check_same_owner(p)) |
37e4ab3f | 5301 | return -EPERM; |
ca94c442 LP |
5302 | |
5303 | /* Normal users shall not reset the sched_reset_on_fork flag */ | |
5304 | if (p->sched_reset_on_fork && !reset_on_fork) | |
5305 | return -EPERM; | |
37e4ab3f | 5306 | } |
1da177e4 | 5307 | |
725aad24 | 5308 | if (user) { |
b0ae1981 | 5309 | retval = security_task_setscheduler(p); |
725aad24 JF |
5310 | if (retval) |
5311 | return retval; | |
5312 | } | |
5313 | ||
b29739f9 IM |
5314 | /* |
5315 | * make sure no PI-waiters arrive (or leave) while we are | |
5316 | * changing the priority of the task: | |
0122ec5b | 5317 | * |
25985edc | 5318 | * To be able to change p->policy safely, the appropriate |
1da177e4 LT |
5319 | * runqueue lock must be held. |
5320 | */ | |
0122ec5b | 5321 | rq = task_rq_lock(p, &flags); |
dc61b1d6 | 5322 | |
34f971f6 PZ |
5323 | /* |
5324 | * Changing the policy of the stop threads its a very bad idea | |
5325 | */ | |
5326 | if (p == rq->stop) { | |
0122ec5b | 5327 | task_rq_unlock(rq, p, &flags); |
34f971f6 PZ |
5328 | return -EINVAL; |
5329 | } | |
5330 | ||
a51e9198 DF |
5331 | /* |
5332 | * If not changing anything there's no need to proceed further: | |
5333 | */ | |
5334 | if (unlikely(policy == p->policy && (!rt_policy(policy) || | |
5335 | param->sched_priority == p->rt_priority))) { | |
5336 | ||
5337 | __task_rq_unlock(rq); | |
5338 | raw_spin_unlock_irqrestore(&p->pi_lock, flags); | |
5339 | return 0; | |
5340 | } | |
5341 | ||
dc61b1d6 PZ |
5342 | #ifdef CONFIG_RT_GROUP_SCHED |
5343 | if (user) { | |
5344 | /* | |
5345 | * Do not allow realtime tasks into groups that have no runtime | |
5346 | * assigned. | |
5347 | */ | |
5348 | if (rt_bandwidth_enabled() && rt_policy(policy) && | |
f4493771 MG |
5349 | task_group(p)->rt_bandwidth.rt_runtime == 0 && |
5350 | !task_group_is_autogroup(task_group(p))) { | |
0122ec5b | 5351 | task_rq_unlock(rq, p, &flags); |
dc61b1d6 PZ |
5352 | return -EPERM; |
5353 | } | |
5354 | } | |
5355 | #endif | |
5356 | ||
1da177e4 LT |
5357 | /* recheck policy now with rq lock held */ |
5358 | if (unlikely(oldpolicy != -1 && oldpolicy != p->policy)) { | |
5359 | policy = oldpolicy = -1; | |
0122ec5b | 5360 | task_rq_unlock(rq, p, &flags); |
1da177e4 LT |
5361 | goto recheck; |
5362 | } | |
fd2f4419 | 5363 | on_rq = p->on_rq; |
051a1d1a | 5364 | running = task_current(rq, p); |
0e1f3483 | 5365 | if (on_rq) |
2e1cb74a | 5366 | deactivate_task(rq, p, 0); |
0e1f3483 HS |
5367 | if (running) |
5368 | p->sched_class->put_prev_task(rq, p); | |
f6b53205 | 5369 | |
ca94c442 LP |
5370 | p->sched_reset_on_fork = reset_on_fork; |
5371 | ||
1da177e4 | 5372 | oldprio = p->prio; |
83ab0aa0 | 5373 | prev_class = p->sched_class; |
dd41f596 | 5374 | __setscheduler(rq, p, policy, param->sched_priority); |
f6b53205 | 5375 | |
0e1f3483 HS |
5376 | if (running) |
5377 | p->sched_class->set_curr_task(rq); | |
da7a735e | 5378 | if (on_rq) |
dd41f596 | 5379 | activate_task(rq, p, 0); |
cb469845 | 5380 | |
da7a735e | 5381 | check_class_changed(rq, p, prev_class, oldprio); |
0122ec5b | 5382 | task_rq_unlock(rq, p, &flags); |
b29739f9 | 5383 | |
95e02ca9 TG |
5384 | rt_mutex_adjust_pi(p); |
5385 | ||
1da177e4 LT |
5386 | return 0; |
5387 | } | |
961ccddd RR |
5388 | |
5389 | /** | |
5390 | * sched_setscheduler - change the scheduling policy and/or RT priority of a thread. | |
5391 | * @p: the task in question. | |
5392 | * @policy: new policy. | |
5393 | * @param: structure containing the new RT priority. | |
5394 | * | |
5395 | * NOTE that the task may be already dead. | |
5396 | */ | |
5397 | int sched_setscheduler(struct task_struct *p, int policy, | |
fe7de49f | 5398 | const struct sched_param *param) |
961ccddd RR |
5399 | { |
5400 | return __sched_setscheduler(p, policy, param, true); | |
5401 | } | |
1da177e4 LT |
5402 | EXPORT_SYMBOL_GPL(sched_setscheduler); |
5403 | ||
961ccddd RR |
5404 | /** |
5405 | * sched_setscheduler_nocheck - change the scheduling policy and/or RT priority of a thread from kernelspace. | |
5406 | * @p: the task in question. | |
5407 | * @policy: new policy. | |
5408 | * @param: structure containing the new RT priority. | |
5409 | * | |
5410 | * Just like sched_setscheduler, only don't bother checking if the | |
5411 | * current context has permission. For example, this is needed in | |
5412 | * stop_machine(): we create temporary high priority worker threads, | |
5413 | * but our caller might not have that capability. | |
5414 | */ | |
5415 | int sched_setscheduler_nocheck(struct task_struct *p, int policy, | |
fe7de49f | 5416 | const struct sched_param *param) |
961ccddd RR |
5417 | { |
5418 | return __sched_setscheduler(p, policy, param, false); | |
5419 | } | |
5420 | ||
95cdf3b7 IM |
5421 | static int |
5422 | do_sched_setscheduler(pid_t pid, int policy, struct sched_param __user *param) | |
1da177e4 | 5423 | { |
1da177e4 LT |
5424 | struct sched_param lparam; |
5425 | struct task_struct *p; | |
36c8b586 | 5426 | int retval; |
1da177e4 LT |
5427 | |
5428 | if (!param || pid < 0) | |
5429 | return -EINVAL; | |
5430 | if (copy_from_user(&lparam, param, sizeof(struct sched_param))) | |
5431 | return -EFAULT; | |
5fe1d75f ON |
5432 | |
5433 | rcu_read_lock(); | |
5434 | retval = -ESRCH; | |
1da177e4 | 5435 | p = find_process_by_pid(pid); |
5fe1d75f ON |
5436 | if (p != NULL) |
5437 | retval = sched_setscheduler(p, policy, &lparam); | |
5438 | rcu_read_unlock(); | |
36c8b586 | 5439 | |
1da177e4 LT |
5440 | return retval; |
5441 | } | |
5442 | ||
5443 | /** | |
5444 | * sys_sched_setscheduler - set/change the scheduler policy and RT priority | |
5445 | * @pid: the pid in question. | |
5446 | * @policy: new policy. | |
5447 | * @param: structure containing the new RT priority. | |
5448 | */ | |
5add95d4 HC |
5449 | SYSCALL_DEFINE3(sched_setscheduler, pid_t, pid, int, policy, |
5450 | struct sched_param __user *, param) | |
1da177e4 | 5451 | { |
c21761f1 JB |
5452 | /* negative values for policy are not valid */ |
5453 | if (policy < 0) | |
5454 | return -EINVAL; | |
5455 | ||
1da177e4 LT |
5456 | return do_sched_setscheduler(pid, policy, param); |
5457 | } | |
5458 | ||
5459 | /** | |
5460 | * sys_sched_setparam - set/change the RT priority of a thread | |
5461 | * @pid: the pid in question. | |
5462 | * @param: structure containing the new RT priority. | |
5463 | */ | |
5add95d4 | 5464 | SYSCALL_DEFINE2(sched_setparam, pid_t, pid, struct sched_param __user *, param) |
1da177e4 LT |
5465 | { |
5466 | return do_sched_setscheduler(pid, -1, param); | |
5467 | } | |
5468 | ||
5469 | /** | |
5470 | * sys_sched_getscheduler - get the policy (scheduling class) of a thread | |
5471 | * @pid: the pid in question. | |
5472 | */ | |
5add95d4 | 5473 | SYSCALL_DEFINE1(sched_getscheduler, pid_t, pid) |
1da177e4 | 5474 | { |
36c8b586 | 5475 | struct task_struct *p; |
3a5c359a | 5476 | int retval; |
1da177e4 LT |
5477 | |
5478 | if (pid < 0) | |
3a5c359a | 5479 | return -EINVAL; |
1da177e4 LT |
5480 | |
5481 | retval = -ESRCH; | |
5fe85be0 | 5482 | rcu_read_lock(); |
1da177e4 LT |
5483 | p = find_process_by_pid(pid); |
5484 | if (p) { | |
5485 | retval = security_task_getscheduler(p); | |
5486 | if (!retval) | |
ca94c442 LP |
5487 | retval = p->policy |
5488 | | (p->sched_reset_on_fork ? SCHED_RESET_ON_FORK : 0); | |
1da177e4 | 5489 | } |
5fe85be0 | 5490 | rcu_read_unlock(); |
1da177e4 LT |
5491 | return retval; |
5492 | } | |
5493 | ||
5494 | /** | |
ca94c442 | 5495 | * sys_sched_getparam - get the RT priority of a thread |
1da177e4 LT |
5496 | * @pid: the pid in question. |
5497 | * @param: structure containing the RT priority. | |
5498 | */ | |
5add95d4 | 5499 | SYSCALL_DEFINE2(sched_getparam, pid_t, pid, struct sched_param __user *, param) |
1da177e4 LT |
5500 | { |
5501 | struct sched_param lp; | |
36c8b586 | 5502 | struct task_struct *p; |
3a5c359a | 5503 | int retval; |
1da177e4 LT |
5504 | |
5505 | if (!param || pid < 0) | |
3a5c359a | 5506 | return -EINVAL; |
1da177e4 | 5507 | |
5fe85be0 | 5508 | rcu_read_lock(); |
1da177e4 LT |
5509 | p = find_process_by_pid(pid); |
5510 | retval = -ESRCH; | |
5511 | if (!p) | |
5512 | goto out_unlock; | |
5513 | ||
5514 | retval = security_task_getscheduler(p); | |
5515 | if (retval) | |
5516 | goto out_unlock; | |
5517 | ||
5518 | lp.sched_priority = p->rt_priority; | |
5fe85be0 | 5519 | rcu_read_unlock(); |
1da177e4 LT |
5520 | |
5521 | /* | |
5522 | * This one might sleep, we cannot do it with a spinlock held ... | |
5523 | */ | |
5524 | retval = copy_to_user(param, &lp, sizeof(*param)) ? -EFAULT : 0; | |
5525 | ||
1da177e4 LT |
5526 | return retval; |
5527 | ||
5528 | out_unlock: | |
5fe85be0 | 5529 | rcu_read_unlock(); |
1da177e4 LT |
5530 | return retval; |
5531 | } | |
5532 | ||
96f874e2 | 5533 | long sched_setaffinity(pid_t pid, const struct cpumask *in_mask) |
1da177e4 | 5534 | { |
5a16f3d3 | 5535 | cpumask_var_t cpus_allowed, new_mask; |
36c8b586 IM |
5536 | struct task_struct *p; |
5537 | int retval; | |
1da177e4 | 5538 | |
95402b38 | 5539 | get_online_cpus(); |
23f5d142 | 5540 | rcu_read_lock(); |
1da177e4 LT |
5541 | |
5542 | p = find_process_by_pid(pid); | |
5543 | if (!p) { | |
23f5d142 | 5544 | rcu_read_unlock(); |
95402b38 | 5545 | put_online_cpus(); |
1da177e4 LT |
5546 | return -ESRCH; |
5547 | } | |
5548 | ||
23f5d142 | 5549 | /* Prevent p going away */ |
1da177e4 | 5550 | get_task_struct(p); |
23f5d142 | 5551 | rcu_read_unlock(); |
1da177e4 | 5552 | |
5a16f3d3 RR |
5553 | if (!alloc_cpumask_var(&cpus_allowed, GFP_KERNEL)) { |
5554 | retval = -ENOMEM; | |
5555 | goto out_put_task; | |
5556 | } | |
5557 | if (!alloc_cpumask_var(&new_mask, GFP_KERNEL)) { | |
5558 | retval = -ENOMEM; | |
5559 | goto out_free_cpus_allowed; | |
5560 | } | |
1da177e4 | 5561 | retval = -EPERM; |
b0e77598 | 5562 | if (!check_same_owner(p) && !task_ns_capable(p, CAP_SYS_NICE)) |
1da177e4 LT |
5563 | goto out_unlock; |
5564 | ||
b0ae1981 | 5565 | retval = security_task_setscheduler(p); |
e7834f8f DQ |
5566 | if (retval) |
5567 | goto out_unlock; | |
5568 | ||
5a16f3d3 RR |
5569 | cpuset_cpus_allowed(p, cpus_allowed); |
5570 | cpumask_and(new_mask, in_mask, cpus_allowed); | |
49246274 | 5571 | again: |
5a16f3d3 | 5572 | retval = set_cpus_allowed_ptr(p, new_mask); |
1da177e4 | 5573 | |
8707d8b8 | 5574 | if (!retval) { |
5a16f3d3 RR |
5575 | cpuset_cpus_allowed(p, cpus_allowed); |
5576 | if (!cpumask_subset(new_mask, cpus_allowed)) { | |
8707d8b8 PM |
5577 | /* |
5578 | * We must have raced with a concurrent cpuset | |
5579 | * update. Just reset the cpus_allowed to the | |
5580 | * cpuset's cpus_allowed | |
5581 | */ | |
5a16f3d3 | 5582 | cpumask_copy(new_mask, cpus_allowed); |
8707d8b8 PM |
5583 | goto again; |
5584 | } | |
5585 | } | |
1da177e4 | 5586 | out_unlock: |
5a16f3d3 RR |
5587 | free_cpumask_var(new_mask); |
5588 | out_free_cpus_allowed: | |
5589 | free_cpumask_var(cpus_allowed); | |
5590 | out_put_task: | |
1da177e4 | 5591 | put_task_struct(p); |
95402b38 | 5592 | put_online_cpus(); |
1da177e4 LT |
5593 | return retval; |
5594 | } | |
5595 | ||
5596 | static int get_user_cpu_mask(unsigned long __user *user_mask_ptr, unsigned len, | |
96f874e2 | 5597 | struct cpumask *new_mask) |
1da177e4 | 5598 | { |
96f874e2 RR |
5599 | if (len < cpumask_size()) |
5600 | cpumask_clear(new_mask); | |
5601 | else if (len > cpumask_size()) | |
5602 | len = cpumask_size(); | |
5603 | ||
1da177e4 LT |
5604 | return copy_from_user(new_mask, user_mask_ptr, len) ? -EFAULT : 0; |
5605 | } | |
5606 | ||
5607 | /** | |
5608 | * sys_sched_setaffinity - set the cpu affinity of a process | |
5609 | * @pid: pid of the process | |
5610 | * @len: length in bytes of the bitmask pointed to by user_mask_ptr | |
5611 | * @user_mask_ptr: user-space pointer to the new cpu mask | |
5612 | */ | |
5add95d4 HC |
5613 | SYSCALL_DEFINE3(sched_setaffinity, pid_t, pid, unsigned int, len, |
5614 | unsigned long __user *, user_mask_ptr) | |
1da177e4 | 5615 | { |
5a16f3d3 | 5616 | cpumask_var_t new_mask; |
1da177e4 LT |
5617 | int retval; |
5618 | ||
5a16f3d3 RR |
5619 | if (!alloc_cpumask_var(&new_mask, GFP_KERNEL)) |
5620 | return -ENOMEM; | |
1da177e4 | 5621 | |
5a16f3d3 RR |
5622 | retval = get_user_cpu_mask(user_mask_ptr, len, new_mask); |
5623 | if (retval == 0) | |
5624 | retval = sched_setaffinity(pid, new_mask); | |
5625 | free_cpumask_var(new_mask); | |
5626 | return retval; | |
1da177e4 LT |
5627 | } |
5628 | ||
96f874e2 | 5629 | long sched_getaffinity(pid_t pid, struct cpumask *mask) |
1da177e4 | 5630 | { |
36c8b586 | 5631 | struct task_struct *p; |
31605683 | 5632 | unsigned long flags; |
1da177e4 | 5633 | int retval; |
1da177e4 | 5634 | |
95402b38 | 5635 | get_online_cpus(); |
23f5d142 | 5636 | rcu_read_lock(); |
1da177e4 LT |
5637 | |
5638 | retval = -ESRCH; | |
5639 | p = find_process_by_pid(pid); | |
5640 | if (!p) | |
5641 | goto out_unlock; | |
5642 | ||
e7834f8f DQ |
5643 | retval = security_task_getscheduler(p); |
5644 | if (retval) | |
5645 | goto out_unlock; | |
5646 | ||
013fdb80 | 5647 | raw_spin_lock_irqsave(&p->pi_lock, flags); |
96f874e2 | 5648 | cpumask_and(mask, &p->cpus_allowed, cpu_online_mask); |
013fdb80 | 5649 | raw_spin_unlock_irqrestore(&p->pi_lock, flags); |
1da177e4 LT |
5650 | |
5651 | out_unlock: | |
23f5d142 | 5652 | rcu_read_unlock(); |
95402b38 | 5653 | put_online_cpus(); |
1da177e4 | 5654 | |
9531b62f | 5655 | return retval; |
1da177e4 LT |
5656 | } |
5657 | ||
5658 | /** | |
5659 | * sys_sched_getaffinity - get the cpu affinity of a process | |
5660 | * @pid: pid of the process | |
5661 | * @len: length in bytes of the bitmask pointed to by user_mask_ptr | |
5662 | * @user_mask_ptr: user-space pointer to hold the current cpu mask | |
5663 | */ | |
5add95d4 HC |
5664 | SYSCALL_DEFINE3(sched_getaffinity, pid_t, pid, unsigned int, len, |
5665 | unsigned long __user *, user_mask_ptr) | |
1da177e4 LT |
5666 | { |
5667 | int ret; | |
f17c8607 | 5668 | cpumask_var_t mask; |
1da177e4 | 5669 | |
84fba5ec | 5670 | if ((len * BITS_PER_BYTE) < nr_cpu_ids) |
cd3d8031 KM |
5671 | return -EINVAL; |
5672 | if (len & (sizeof(unsigned long)-1)) | |
1da177e4 LT |
5673 | return -EINVAL; |
5674 | ||
f17c8607 RR |
5675 | if (!alloc_cpumask_var(&mask, GFP_KERNEL)) |
5676 | return -ENOMEM; | |
1da177e4 | 5677 | |
f17c8607 RR |
5678 | ret = sched_getaffinity(pid, mask); |
5679 | if (ret == 0) { | |
8bc037fb | 5680 | size_t retlen = min_t(size_t, len, cpumask_size()); |
cd3d8031 KM |
5681 | |
5682 | if (copy_to_user(user_mask_ptr, mask, retlen)) | |
f17c8607 RR |
5683 | ret = -EFAULT; |
5684 | else | |
cd3d8031 | 5685 | ret = retlen; |
f17c8607 RR |
5686 | } |
5687 | free_cpumask_var(mask); | |
1da177e4 | 5688 | |
f17c8607 | 5689 | return ret; |
1da177e4 LT |
5690 | } |
5691 | ||
5692 | /** | |
5693 | * sys_sched_yield - yield the current processor to other threads. | |
5694 | * | |
dd41f596 IM |
5695 | * This function yields the current CPU to other tasks. If there are no |
5696 | * other threads running on this CPU then this function will return. | |
1da177e4 | 5697 | */ |
5add95d4 | 5698 | SYSCALL_DEFINE0(sched_yield) |
1da177e4 | 5699 | { |
70b97a7f | 5700 | struct rq *rq = this_rq_lock(); |
1da177e4 | 5701 | |
2d72376b | 5702 | schedstat_inc(rq, yld_count); |
4530d7ab | 5703 | current->sched_class->yield_task(rq); |
1da177e4 LT |
5704 | |
5705 | /* | |
5706 | * Since we are going to call schedule() anyway, there's | |
5707 | * no need to preempt or enable interrupts: | |
5708 | */ | |
5709 | __release(rq->lock); | |
8a25d5de | 5710 | spin_release(&rq->lock.dep_map, 1, _THIS_IP_); |
9828ea9d | 5711 | do_raw_spin_unlock(&rq->lock); |
1da177e4 LT |
5712 | preempt_enable_no_resched(); |
5713 | ||
5714 | schedule(); | |
5715 | ||
5716 | return 0; | |
5717 | } | |
5718 | ||
d86ee480 PZ |
5719 | static inline int should_resched(void) |
5720 | { | |
5721 | return need_resched() && !(preempt_count() & PREEMPT_ACTIVE); | |
5722 | } | |
5723 | ||
e7b38404 | 5724 | static void __cond_resched(void) |
1da177e4 | 5725 | { |
e7aaaa69 | 5726 | add_preempt_count(PREEMPT_ACTIVE); |
c259e01a | 5727 | __schedule(); |
e7aaaa69 | 5728 | sub_preempt_count(PREEMPT_ACTIVE); |
1da177e4 LT |
5729 | } |
5730 | ||
02b67cc3 | 5731 | int __sched _cond_resched(void) |
1da177e4 | 5732 | { |
d86ee480 | 5733 | if (should_resched()) { |
1da177e4 LT |
5734 | __cond_resched(); |
5735 | return 1; | |
5736 | } | |
5737 | return 0; | |
5738 | } | |
02b67cc3 | 5739 | EXPORT_SYMBOL(_cond_resched); |
1da177e4 LT |
5740 | |
5741 | /* | |
613afbf8 | 5742 | * __cond_resched_lock() - if a reschedule is pending, drop the given lock, |
1da177e4 LT |
5743 | * call schedule, and on return reacquire the lock. |
5744 | * | |
41a2d6cf | 5745 | * This works OK both with and without CONFIG_PREEMPT. We do strange low-level |
1da177e4 LT |
5746 | * operations here to prevent schedule() from being called twice (once via |
5747 | * spin_unlock(), once by hand). | |
5748 | */ | |
613afbf8 | 5749 | int __cond_resched_lock(spinlock_t *lock) |
1da177e4 | 5750 | { |
d86ee480 | 5751 | int resched = should_resched(); |
6df3cecb JK |
5752 | int ret = 0; |
5753 | ||
f607c668 PZ |
5754 | lockdep_assert_held(lock); |
5755 | ||
95c354fe | 5756 | if (spin_needbreak(lock) || resched) { |
1da177e4 | 5757 | spin_unlock(lock); |
d86ee480 | 5758 | if (resched) |
95c354fe NP |
5759 | __cond_resched(); |
5760 | else | |
5761 | cpu_relax(); | |
6df3cecb | 5762 | ret = 1; |
1da177e4 | 5763 | spin_lock(lock); |
1da177e4 | 5764 | } |
6df3cecb | 5765 | return ret; |
1da177e4 | 5766 | } |
613afbf8 | 5767 | EXPORT_SYMBOL(__cond_resched_lock); |
1da177e4 | 5768 | |
613afbf8 | 5769 | int __sched __cond_resched_softirq(void) |
1da177e4 LT |
5770 | { |
5771 | BUG_ON(!in_softirq()); | |
5772 | ||
d86ee480 | 5773 | if (should_resched()) { |
98d82567 | 5774 | local_bh_enable(); |
1da177e4 LT |
5775 | __cond_resched(); |
5776 | local_bh_disable(); | |
5777 | return 1; | |
5778 | } | |
5779 | return 0; | |
5780 | } | |
613afbf8 | 5781 | EXPORT_SYMBOL(__cond_resched_softirq); |
1da177e4 | 5782 | |
1da177e4 LT |
5783 | /** |
5784 | * yield - yield the current processor to other threads. | |
5785 | * | |
72fd4a35 | 5786 | * This is a shortcut for kernel-space yielding - it marks the |
1da177e4 LT |
5787 | * thread runnable and calls sys_sched_yield(). |
5788 | */ | |
5789 | void __sched yield(void) | |
5790 | { | |
5791 | set_current_state(TASK_RUNNING); | |
5792 | sys_sched_yield(); | |
5793 | } | |
1da177e4 LT |
5794 | EXPORT_SYMBOL(yield); |
5795 | ||
d95f4122 MG |
5796 | /** |
5797 | * yield_to - yield the current processor to another thread in | |
5798 | * your thread group, or accelerate that thread toward the | |
5799 | * processor it's on. | |
16addf95 RD |
5800 | * @p: target task |
5801 | * @preempt: whether task preemption is allowed or not | |
d95f4122 MG |
5802 | * |
5803 | * It's the caller's job to ensure that the target task struct | |
5804 | * can't go away on us before we can do any checks. | |
5805 | * | |
5806 | * Returns true if we indeed boosted the target task. | |
5807 | */ | |
5808 | bool __sched yield_to(struct task_struct *p, bool preempt) | |
5809 | { | |
5810 | struct task_struct *curr = current; | |
5811 | struct rq *rq, *p_rq; | |
5812 | unsigned long flags; | |
5813 | bool yielded = 0; | |
5814 | ||
5815 | local_irq_save(flags); | |
5816 | rq = this_rq(); | |
5817 | ||
5818 | again: | |
5819 | p_rq = task_rq(p); | |
5820 | double_rq_lock(rq, p_rq); | |
5821 | while (task_rq(p) != p_rq) { | |
5822 | double_rq_unlock(rq, p_rq); | |
5823 | goto again; | |
5824 | } | |
5825 | ||
5826 | if (!curr->sched_class->yield_to_task) | |
5827 | goto out; | |
5828 | ||
5829 | if (curr->sched_class != p->sched_class) | |
5830 | goto out; | |
5831 | ||
5832 | if (task_running(p_rq, p) || p->state) | |
5833 | goto out; | |
5834 | ||
5835 | yielded = curr->sched_class->yield_to_task(rq, p, preempt); | |
6d1cafd8 | 5836 | if (yielded) { |
d95f4122 | 5837 | schedstat_inc(rq, yld_count); |
6d1cafd8 VP |
5838 | /* |
5839 | * Make p's CPU reschedule; pick_next_entity takes care of | |
5840 | * fairness. | |
5841 | */ | |
5842 | if (preempt && rq != p_rq) | |
5843 | resched_task(p_rq->curr); | |
5844 | } | |
d95f4122 MG |
5845 | |
5846 | out: | |
5847 | double_rq_unlock(rq, p_rq); | |
5848 | local_irq_restore(flags); | |
5849 | ||
5850 | if (yielded) | |
5851 | schedule(); | |
5852 | ||
5853 | return yielded; | |
5854 | } | |
5855 | EXPORT_SYMBOL_GPL(yield_to); | |
5856 | ||
1da177e4 | 5857 | /* |
41a2d6cf | 5858 | * This task is about to go to sleep on IO. Increment rq->nr_iowait so |
1da177e4 | 5859 | * that process accounting knows that this is a task in IO wait state. |
1da177e4 LT |
5860 | */ |
5861 | void __sched io_schedule(void) | |
5862 | { | |
54d35f29 | 5863 | struct rq *rq = raw_rq(); |
1da177e4 | 5864 | |
0ff92245 | 5865 | delayacct_blkio_start(); |
1da177e4 | 5866 | atomic_inc(&rq->nr_iowait); |
73c10101 | 5867 | blk_flush_plug(current); |
8f0dfc34 | 5868 | current->in_iowait = 1; |
1da177e4 | 5869 | schedule(); |
8f0dfc34 | 5870 | current->in_iowait = 0; |
1da177e4 | 5871 | atomic_dec(&rq->nr_iowait); |
0ff92245 | 5872 | delayacct_blkio_end(); |
1da177e4 | 5873 | } |
1da177e4 LT |
5874 | EXPORT_SYMBOL(io_schedule); |
5875 | ||
5876 | long __sched io_schedule_timeout(long timeout) | |
5877 | { | |
54d35f29 | 5878 | struct rq *rq = raw_rq(); |
1da177e4 LT |
5879 | long ret; |
5880 | ||
0ff92245 | 5881 | delayacct_blkio_start(); |
1da177e4 | 5882 | atomic_inc(&rq->nr_iowait); |
73c10101 | 5883 | blk_flush_plug(current); |
8f0dfc34 | 5884 | current->in_iowait = 1; |
1da177e4 | 5885 | ret = schedule_timeout(timeout); |
8f0dfc34 | 5886 | current->in_iowait = 0; |
1da177e4 | 5887 | atomic_dec(&rq->nr_iowait); |
0ff92245 | 5888 | delayacct_blkio_end(); |
1da177e4 LT |
5889 | return ret; |
5890 | } | |
5891 | ||
5892 | /** | |
5893 | * sys_sched_get_priority_max - return maximum RT priority. | |
5894 | * @policy: scheduling class. | |
5895 | * | |
5896 | * this syscall returns the maximum rt_priority that can be used | |
5897 | * by a given scheduling class. | |
5898 | */ | |
5add95d4 | 5899 | SYSCALL_DEFINE1(sched_get_priority_max, int, policy) |
1da177e4 LT |
5900 | { |
5901 | int ret = -EINVAL; | |
5902 | ||
5903 | switch (policy) { | |
5904 | case SCHED_FIFO: | |
5905 | case SCHED_RR: | |
5906 | ret = MAX_USER_RT_PRIO-1; | |
5907 | break; | |
5908 | case SCHED_NORMAL: | |
b0a9499c | 5909 | case SCHED_BATCH: |
dd41f596 | 5910 | case SCHED_IDLE: |
1da177e4 LT |
5911 | ret = 0; |
5912 | break; | |
5913 | } | |
5914 | return ret; | |
5915 | } | |
5916 | ||
5917 | /** | |
5918 | * sys_sched_get_priority_min - return minimum RT priority. | |
5919 | * @policy: scheduling class. | |
5920 | * | |
5921 | * this syscall returns the minimum rt_priority that can be used | |
5922 | * by a given scheduling class. | |
5923 | */ | |
5add95d4 | 5924 | SYSCALL_DEFINE1(sched_get_priority_min, int, policy) |
1da177e4 LT |
5925 | { |
5926 | int ret = -EINVAL; | |
5927 | ||
5928 | switch (policy) { | |
5929 | case SCHED_FIFO: | |
5930 | case SCHED_RR: | |
5931 | ret = 1; | |
5932 | break; | |
5933 | case SCHED_NORMAL: | |
b0a9499c | 5934 | case SCHED_BATCH: |
dd41f596 | 5935 | case SCHED_IDLE: |
1da177e4 LT |
5936 | ret = 0; |
5937 | } | |
5938 | return ret; | |
5939 | } | |
5940 | ||
5941 | /** | |
5942 | * sys_sched_rr_get_interval - return the default timeslice of a process. | |
5943 | * @pid: pid of the process. | |
5944 | * @interval: userspace pointer to the timeslice value. | |
5945 | * | |
5946 | * this syscall writes the default timeslice value of a given process | |
5947 | * into the user-space timespec buffer. A value of '0' means infinity. | |
5948 | */ | |
17da2bd9 | 5949 | SYSCALL_DEFINE2(sched_rr_get_interval, pid_t, pid, |
754fe8d2 | 5950 | struct timespec __user *, interval) |
1da177e4 | 5951 | { |
36c8b586 | 5952 | struct task_struct *p; |
a4ec24b4 | 5953 | unsigned int time_slice; |
dba091b9 TG |
5954 | unsigned long flags; |
5955 | struct rq *rq; | |
3a5c359a | 5956 | int retval; |
1da177e4 | 5957 | struct timespec t; |
1da177e4 LT |
5958 | |
5959 | if (pid < 0) | |
3a5c359a | 5960 | return -EINVAL; |
1da177e4 LT |
5961 | |
5962 | retval = -ESRCH; | |
1a551ae7 | 5963 | rcu_read_lock(); |
1da177e4 LT |
5964 | p = find_process_by_pid(pid); |
5965 | if (!p) | |
5966 | goto out_unlock; | |
5967 | ||
5968 | retval = security_task_getscheduler(p); | |
5969 | if (retval) | |
5970 | goto out_unlock; | |
5971 | ||
dba091b9 TG |
5972 | rq = task_rq_lock(p, &flags); |
5973 | time_slice = p->sched_class->get_rr_interval(rq, p); | |
0122ec5b | 5974 | task_rq_unlock(rq, p, &flags); |
a4ec24b4 | 5975 | |
1a551ae7 | 5976 | rcu_read_unlock(); |
a4ec24b4 | 5977 | jiffies_to_timespec(time_slice, &t); |
1da177e4 | 5978 | retval = copy_to_user(interval, &t, sizeof(t)) ? -EFAULT : 0; |
1da177e4 | 5979 | return retval; |
3a5c359a | 5980 | |
1da177e4 | 5981 | out_unlock: |
1a551ae7 | 5982 | rcu_read_unlock(); |
1da177e4 LT |
5983 | return retval; |
5984 | } | |
5985 | ||
7c731e0a | 5986 | static const char stat_nam[] = TASK_STATE_TO_CHAR_STR; |
36c8b586 | 5987 | |
82a1fcb9 | 5988 | void sched_show_task(struct task_struct *p) |
1da177e4 | 5989 | { |
1da177e4 | 5990 | unsigned long free = 0; |
36c8b586 | 5991 | unsigned state; |
1da177e4 | 5992 | |
1da177e4 | 5993 | state = p->state ? __ffs(p->state) + 1 : 0; |
28d0686c | 5994 | printk(KERN_INFO "%-15.15s %c", p->comm, |
2ed6e34f | 5995 | state < sizeof(stat_nam) - 1 ? stat_nam[state] : '?'); |
4bd77321 | 5996 | #if BITS_PER_LONG == 32 |
1da177e4 | 5997 | if (state == TASK_RUNNING) |
3df0fc5b | 5998 | printk(KERN_CONT " running "); |
1da177e4 | 5999 | else |
3df0fc5b | 6000 | printk(KERN_CONT " %08lx ", thread_saved_pc(p)); |
1da177e4 LT |
6001 | #else |
6002 | if (state == TASK_RUNNING) | |
3df0fc5b | 6003 | printk(KERN_CONT " running task "); |
1da177e4 | 6004 | else |
3df0fc5b | 6005 | printk(KERN_CONT " %016lx ", thread_saved_pc(p)); |
1da177e4 LT |
6006 | #endif |
6007 | #ifdef CONFIG_DEBUG_STACK_USAGE | |
7c9f8861 | 6008 | free = stack_not_used(p); |
1da177e4 | 6009 | #endif |
3df0fc5b | 6010 | printk(KERN_CONT "%5lu %5d %6d 0x%08lx\n", free, |
aa47b7e0 DR |
6011 | task_pid_nr(p), task_pid_nr(p->real_parent), |
6012 | (unsigned long)task_thread_info(p)->flags); | |
1da177e4 | 6013 | |
5fb5e6de | 6014 | show_stack(p, NULL); |
1da177e4 LT |
6015 | } |
6016 | ||
e59e2ae2 | 6017 | void show_state_filter(unsigned long state_filter) |
1da177e4 | 6018 | { |
36c8b586 | 6019 | struct task_struct *g, *p; |
1da177e4 | 6020 | |
4bd77321 | 6021 | #if BITS_PER_LONG == 32 |
3df0fc5b PZ |
6022 | printk(KERN_INFO |
6023 | " task PC stack pid father\n"); | |
1da177e4 | 6024 | #else |
3df0fc5b PZ |
6025 | printk(KERN_INFO |
6026 | " task PC stack pid father\n"); | |
1da177e4 | 6027 | #endif |
510f5acc | 6028 | rcu_read_lock(); |
1da177e4 LT |
6029 | do_each_thread(g, p) { |
6030 | /* | |
6031 | * reset the NMI-timeout, listing all files on a slow | |
25985edc | 6032 | * console might take a lot of time: |
1da177e4 LT |
6033 | */ |
6034 | touch_nmi_watchdog(); | |
39bc89fd | 6035 | if (!state_filter || (p->state & state_filter)) |
82a1fcb9 | 6036 | sched_show_task(p); |
1da177e4 LT |
6037 | } while_each_thread(g, p); |
6038 | ||
04c9167f JF |
6039 | touch_all_softlockup_watchdogs(); |
6040 | ||
dd41f596 IM |
6041 | #ifdef CONFIG_SCHED_DEBUG |
6042 | sysrq_sched_debug_show(); | |
6043 | #endif | |
510f5acc | 6044 | rcu_read_unlock(); |
e59e2ae2 IM |
6045 | /* |
6046 | * Only show locks if all tasks are dumped: | |
6047 | */ | |
93335a21 | 6048 | if (!state_filter) |
e59e2ae2 | 6049 | debug_show_all_locks(); |
1da177e4 LT |
6050 | } |
6051 | ||
1df21055 IM |
6052 | void __cpuinit init_idle_bootup_task(struct task_struct *idle) |
6053 | { | |
dd41f596 | 6054 | idle->sched_class = &idle_sched_class; |
1df21055 IM |
6055 | } |
6056 | ||
f340c0d1 IM |
6057 | /** |
6058 | * init_idle - set up an idle thread for a given CPU | |
6059 | * @idle: task in question | |
6060 | * @cpu: cpu the idle task belongs to | |
6061 | * | |
6062 | * NOTE: this function does not set the idle thread's NEED_RESCHED | |
6063 | * flag, to make booting more robust. | |
6064 | */ | |
5c1e1767 | 6065 | void __cpuinit init_idle(struct task_struct *idle, int cpu) |
1da177e4 | 6066 | { |
70b97a7f | 6067 | struct rq *rq = cpu_rq(cpu); |
1da177e4 LT |
6068 | unsigned long flags; |
6069 | ||
05fa785c | 6070 | raw_spin_lock_irqsave(&rq->lock, flags); |
5cbd54ef | 6071 | |
dd41f596 | 6072 | __sched_fork(idle); |
06b83b5f | 6073 | idle->state = TASK_RUNNING; |
dd41f596 IM |
6074 | idle->se.exec_start = sched_clock(); |
6075 | ||
1e1b6c51 | 6076 | do_set_cpus_allowed(idle, cpumask_of(cpu)); |
6506cf6c PZ |
6077 | /* |
6078 | * We're having a chicken and egg problem, even though we are | |
6079 | * holding rq->lock, the cpu isn't yet set to this cpu so the | |
6080 | * lockdep check in task_group() will fail. | |
6081 | * | |
6082 | * Similar case to sched_fork(). / Alternatively we could | |
6083 | * use task_rq_lock() here and obtain the other rq->lock. | |
6084 | * | |
6085 | * Silence PROVE_RCU | |
6086 | */ | |
6087 | rcu_read_lock(); | |
dd41f596 | 6088 | __set_task_cpu(idle, cpu); |
6506cf6c | 6089 | rcu_read_unlock(); |
1da177e4 | 6090 | |
1da177e4 | 6091 | rq->curr = rq->idle = idle; |
3ca7a440 PZ |
6092 | #if defined(CONFIG_SMP) |
6093 | idle->on_cpu = 1; | |
4866cde0 | 6094 | #endif |
05fa785c | 6095 | raw_spin_unlock_irqrestore(&rq->lock, flags); |
1da177e4 LT |
6096 | |
6097 | /* Set the preempt count _outside_ the spinlocks! */ | |
a1261f54 | 6098 | task_thread_info(idle)->preempt_count = 0; |
625f2a37 | 6099 | |
dd41f596 IM |
6100 | /* |
6101 | * The idle tasks have their own, simple scheduling class: | |
6102 | */ | |
6103 | idle->sched_class = &idle_sched_class; | |
868baf07 | 6104 | ftrace_graph_init_idle_task(idle, cpu); |
f1c6f1a7 CE |
6105 | #if defined(CONFIG_SMP) |
6106 | sprintf(idle->comm, "%s/%d", INIT_TASK_COMM, cpu); | |
6107 | #endif | |
1da177e4 LT |
6108 | } |
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); | |
4939602a PZ |
6162 | |
6163 | cpumask_copy(&p->cpus_allowed, new_mask); | |
6164 | p->rt.nr_cpus_allowed = cpumask_weight(new_mask); | |
1e1b6c51 KM |
6165 | } |
6166 | ||
1da177e4 LT |
6167 | /* |
6168 | * This is how migration works: | |
6169 | * | |
969c7921 TH |
6170 | * 1) we invoke migration_cpu_stop() on the target CPU using |
6171 | * stop_one_cpu(). | |
6172 | * 2) stopper starts to run (implicitly forcing the migrated thread | |
6173 | * off the CPU) | |
6174 | * 3) it checks whether the migrated task is still in the wrong runqueue. | |
6175 | * 4) if it's in the wrong runqueue then the migration thread removes | |
1da177e4 | 6176 | * it and puts it into the right queue. |
969c7921 TH |
6177 | * 5) stopper completes and stop_one_cpu() returns and the migration |
6178 | * is done. | |
1da177e4 LT |
6179 | */ |
6180 | ||
6181 | /* | |
6182 | * Change a given task's CPU affinity. Migrate the thread to a | |
6183 | * proper CPU and schedule it away if the CPU it's executing on | |
6184 | * is removed from the allowed bitmask. | |
6185 | * | |
6186 | * NOTE: the caller must have a valid reference to the task, the | |
41a2d6cf | 6187 | * task must not exit() & deallocate itself prematurely. The |
1da177e4 LT |
6188 | * call is not atomic; no spinlocks may be held. |
6189 | */ | |
96f874e2 | 6190 | int set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask) |
1da177e4 LT |
6191 | { |
6192 | unsigned long flags; | |
70b97a7f | 6193 | struct rq *rq; |
969c7921 | 6194 | unsigned int dest_cpu; |
48f24c4d | 6195 | int ret = 0; |
1da177e4 LT |
6196 | |
6197 | rq = task_rq_lock(p, &flags); | |
e2912009 | 6198 | |
db44fc01 YZ |
6199 | if (cpumask_equal(&p->cpus_allowed, new_mask)) |
6200 | goto out; | |
6201 | ||
6ad4c188 | 6202 | if (!cpumask_intersects(new_mask, cpu_active_mask)) { |
1da177e4 LT |
6203 | ret = -EINVAL; |
6204 | goto out; | |
6205 | } | |
6206 | ||
db44fc01 | 6207 | if (unlikely((p->flags & PF_THREAD_BOUND) && p != current)) { |
9985b0ba DR |
6208 | ret = -EINVAL; |
6209 | goto out; | |
6210 | } | |
6211 | ||
1e1b6c51 | 6212 | do_set_cpus_allowed(p, new_mask); |
73fe6aae | 6213 | |
1da177e4 | 6214 | /* Can the task run on the task's current CPU? If so, we're done */ |
96f874e2 | 6215 | if (cpumask_test_cpu(task_cpu(p), new_mask)) |
1da177e4 LT |
6216 | goto out; |
6217 | ||
969c7921 | 6218 | dest_cpu = cpumask_any_and(cpu_active_mask, new_mask); |
bd8e7dde | 6219 | if (p->on_rq) { |
969c7921 | 6220 | struct migration_arg arg = { p, dest_cpu }; |
1da177e4 | 6221 | /* Need help from migration thread: drop lock and wait. */ |
0122ec5b | 6222 | task_rq_unlock(rq, p, &flags); |
969c7921 | 6223 | stop_one_cpu(cpu_of(rq), migration_cpu_stop, &arg); |
1da177e4 LT |
6224 | tlb_migrate_finish(p->mm); |
6225 | return 0; | |
6226 | } | |
6227 | out: | |
0122ec5b | 6228 | task_rq_unlock(rq, p, &flags); |
48f24c4d | 6229 | |
1da177e4 LT |
6230 | return ret; |
6231 | } | |
cd8ba7cd | 6232 | EXPORT_SYMBOL_GPL(set_cpus_allowed_ptr); |
1da177e4 LT |
6233 | |
6234 | /* | |
41a2d6cf | 6235 | * Move (not current) task off this cpu, onto dest cpu. We're doing |
1da177e4 LT |
6236 | * this because either it can't run here any more (set_cpus_allowed() |
6237 | * away from this CPU, or CPU going down), or because we're | |
6238 | * attempting to rebalance this task on exec (sched_exec). | |
6239 | * | |
6240 | * So we race with normal scheduler movements, but that's OK, as long | |
6241 | * as the task is no longer on this CPU. | |
efc30814 KK |
6242 | * |
6243 | * Returns non-zero if task was successfully migrated. | |
1da177e4 | 6244 | */ |
efc30814 | 6245 | static int __migrate_task(struct task_struct *p, int src_cpu, int dest_cpu) |
1da177e4 | 6246 | { |
70b97a7f | 6247 | struct rq *rq_dest, *rq_src; |
e2912009 | 6248 | int ret = 0; |
1da177e4 | 6249 | |
e761b772 | 6250 | if (unlikely(!cpu_active(dest_cpu))) |
efc30814 | 6251 | return ret; |
1da177e4 LT |
6252 | |
6253 | rq_src = cpu_rq(src_cpu); | |
6254 | rq_dest = cpu_rq(dest_cpu); | |
6255 | ||
0122ec5b | 6256 | raw_spin_lock(&p->pi_lock); |
1da177e4 LT |
6257 | double_rq_lock(rq_src, rq_dest); |
6258 | /* Already moved. */ | |
6259 | if (task_cpu(p) != src_cpu) | |
b1e38734 | 6260 | goto done; |
1da177e4 | 6261 | /* Affinity changed (again). */ |
fa17b507 | 6262 | if (!cpumask_test_cpu(dest_cpu, tsk_cpus_allowed(p))) |
b1e38734 | 6263 | goto fail; |
1da177e4 | 6264 | |
e2912009 PZ |
6265 | /* |
6266 | * If we're not on a rq, the next wake-up will ensure we're | |
6267 | * placed properly. | |
6268 | */ | |
fd2f4419 | 6269 | if (p->on_rq) { |
2e1cb74a | 6270 | deactivate_task(rq_src, p, 0); |
e2912009 | 6271 | set_task_cpu(p, dest_cpu); |
dd41f596 | 6272 | activate_task(rq_dest, p, 0); |
15afe09b | 6273 | check_preempt_curr(rq_dest, p, 0); |
1da177e4 | 6274 | } |
b1e38734 | 6275 | done: |
efc30814 | 6276 | ret = 1; |
b1e38734 | 6277 | fail: |
1da177e4 | 6278 | double_rq_unlock(rq_src, rq_dest); |
0122ec5b | 6279 | raw_spin_unlock(&p->pi_lock); |
efc30814 | 6280 | return ret; |
1da177e4 LT |
6281 | } |
6282 | ||
6283 | /* | |
969c7921 TH |
6284 | * migration_cpu_stop - this will be executed by a highprio stopper thread |
6285 | * and performs thread migration by bumping thread off CPU then | |
6286 | * 'pushing' onto another runqueue. | |
1da177e4 | 6287 | */ |
969c7921 | 6288 | static int migration_cpu_stop(void *data) |
1da177e4 | 6289 | { |
969c7921 | 6290 | struct migration_arg *arg = data; |
f7b4cddc | 6291 | |
969c7921 TH |
6292 | /* |
6293 | * The original target cpu might have gone down and we might | |
6294 | * be on another cpu but it doesn't matter. | |
6295 | */ | |
f7b4cddc | 6296 | local_irq_disable(); |
969c7921 | 6297 | __migrate_task(arg->task, raw_smp_processor_id(), arg->dest_cpu); |
f7b4cddc | 6298 | local_irq_enable(); |
1da177e4 | 6299 | return 0; |
f7b4cddc ON |
6300 | } |
6301 | ||
1da177e4 | 6302 | #ifdef CONFIG_HOTPLUG_CPU |
48c5ccae | 6303 | |
054b9108 | 6304 | /* |
48c5ccae PZ |
6305 | * Ensures that the idle task is using init_mm right before its cpu goes |
6306 | * offline. | |
054b9108 | 6307 | */ |
48c5ccae | 6308 | void idle_task_exit(void) |
1da177e4 | 6309 | { |
48c5ccae | 6310 | struct mm_struct *mm = current->active_mm; |
e76bd8d9 | 6311 | |
48c5ccae | 6312 | BUG_ON(cpu_online(smp_processor_id())); |
e76bd8d9 | 6313 | |
48c5ccae PZ |
6314 | if (mm != &init_mm) |
6315 | switch_mm(mm, &init_mm, current); | |
6316 | mmdrop(mm); | |
1da177e4 LT |
6317 | } |
6318 | ||
6319 | /* | |
6320 | * While a dead CPU has no uninterruptible tasks queued at this point, | |
6321 | * it might still have a nonzero ->nr_uninterruptible counter, because | |
6322 | * for performance reasons the counter is not stricly tracking tasks to | |
6323 | * their home CPUs. So we just add the counter to another CPU's counter, | |
6324 | * to keep the global sum constant after CPU-down: | |
6325 | */ | |
70b97a7f | 6326 | static void migrate_nr_uninterruptible(struct rq *rq_src) |
1da177e4 | 6327 | { |
6ad4c188 | 6328 | struct rq *rq_dest = cpu_rq(cpumask_any(cpu_active_mask)); |
1da177e4 | 6329 | |
1da177e4 LT |
6330 | rq_dest->nr_uninterruptible += rq_src->nr_uninterruptible; |
6331 | rq_src->nr_uninterruptible = 0; | |
1da177e4 LT |
6332 | } |
6333 | ||
dd41f596 | 6334 | /* |
48c5ccae | 6335 | * remove the tasks which were accounted by rq from calc_load_tasks. |
1da177e4 | 6336 | */ |
48c5ccae | 6337 | static void calc_global_load_remove(struct rq *rq) |
1da177e4 | 6338 | { |
48c5ccae PZ |
6339 | atomic_long_sub(rq->calc_load_active, &calc_load_tasks); |
6340 | rq->calc_load_active = 0; | |
1da177e4 LT |
6341 | } |
6342 | ||
8cb120d3 PT |
6343 | #ifdef CONFIG_CFS_BANDWIDTH |
6344 | static void unthrottle_offline_cfs_rqs(struct rq *rq) | |
6345 | { | |
6346 | struct cfs_rq *cfs_rq; | |
6347 | ||
6348 | for_each_leaf_cfs_rq(rq, cfs_rq) { | |
6349 | struct cfs_bandwidth *cfs_b = tg_cfs_bandwidth(cfs_rq->tg); | |
6350 | ||
6351 | if (!cfs_rq->runtime_enabled) | |
6352 | continue; | |
6353 | ||
6354 | /* | |
6355 | * clock_task is not advancing so we just need to make sure | |
6356 | * there's some valid quota amount | |
6357 | */ | |
6358 | cfs_rq->runtime_remaining = cfs_b->quota; | |
6359 | if (cfs_rq_throttled(cfs_rq)) | |
6360 | unthrottle_cfs_rq(cfs_rq); | |
6361 | } | |
6362 | } | |
6363 | #else | |
6364 | static void unthrottle_offline_cfs_rqs(struct rq *rq) {} | |
6365 | #endif | |
6366 | ||
48f24c4d | 6367 | /* |
48c5ccae PZ |
6368 | * Migrate all tasks from the rq, sleeping tasks will be migrated by |
6369 | * try_to_wake_up()->select_task_rq(). | |
6370 | * | |
6371 | * Called with rq->lock held even though we'er in stop_machine() and | |
6372 | * there's no concurrency possible, we hold the required locks anyway | |
6373 | * because of lock validation efforts. | |
1da177e4 | 6374 | */ |
48c5ccae | 6375 | static void migrate_tasks(unsigned int dead_cpu) |
1da177e4 | 6376 | { |
70b97a7f | 6377 | struct rq *rq = cpu_rq(dead_cpu); |
48c5ccae PZ |
6378 | struct task_struct *next, *stop = rq->stop; |
6379 | int dest_cpu; | |
1da177e4 LT |
6380 | |
6381 | /* | |
48c5ccae PZ |
6382 | * Fudge the rq selection such that the below task selection loop |
6383 | * doesn't get stuck on the currently eligible stop task. | |
6384 | * | |
6385 | * We're currently inside stop_machine() and the rq is either stuck | |
6386 | * in the stop_machine_cpu_stop() loop, or we're executing this code, | |
6387 | * either way we should never end up calling schedule() until we're | |
6388 | * done here. | |
1da177e4 | 6389 | */ |
48c5ccae | 6390 | rq->stop = NULL; |
48f24c4d | 6391 | |
8cb120d3 PT |
6392 | /* Ensure any throttled groups are reachable by pick_next_task */ |
6393 | unthrottle_offline_cfs_rqs(rq); | |
6394 | ||
dd41f596 | 6395 | for ( ; ; ) { |
48c5ccae PZ |
6396 | /* |
6397 | * There's this thread running, bail when that's the only | |
6398 | * remaining thread. | |
6399 | */ | |
6400 | if (rq->nr_running == 1) | |
dd41f596 | 6401 | break; |
48c5ccae | 6402 | |
b67802ea | 6403 | next = pick_next_task(rq); |
48c5ccae | 6404 | BUG_ON(!next); |
79c53799 | 6405 | next->sched_class->put_prev_task(rq, next); |
e692ab53 | 6406 | |
48c5ccae PZ |
6407 | /* Find suitable destination for @next, with force if needed. */ |
6408 | dest_cpu = select_fallback_rq(dead_cpu, next); | |
6409 | raw_spin_unlock(&rq->lock); | |
6410 | ||
6411 | __migrate_task(next, dead_cpu, dest_cpu); | |
6412 | ||
6413 | raw_spin_lock(&rq->lock); | |
1da177e4 | 6414 | } |
dce48a84 | 6415 | |
48c5ccae | 6416 | rq->stop = stop; |
dce48a84 | 6417 | } |
48c5ccae | 6418 | |
1da177e4 LT |
6419 | #endif /* CONFIG_HOTPLUG_CPU */ |
6420 | ||
e692ab53 NP |
6421 | #if defined(CONFIG_SCHED_DEBUG) && defined(CONFIG_SYSCTL) |
6422 | ||
6423 | static struct ctl_table sd_ctl_dir[] = { | |
e0361851 AD |
6424 | { |
6425 | .procname = "sched_domain", | |
c57baf1e | 6426 | .mode = 0555, |
e0361851 | 6427 | }, |
56992309 | 6428 | {} |
e692ab53 NP |
6429 | }; |
6430 | ||
6431 | static struct ctl_table sd_ctl_root[] = { | |
e0361851 AD |
6432 | { |
6433 | .procname = "kernel", | |
c57baf1e | 6434 | .mode = 0555, |
e0361851 AD |
6435 | .child = sd_ctl_dir, |
6436 | }, | |
56992309 | 6437 | {} |
e692ab53 NP |
6438 | }; |
6439 | ||
6440 | static struct ctl_table *sd_alloc_ctl_entry(int n) | |
6441 | { | |
6442 | struct ctl_table *entry = | |
5cf9f062 | 6443 | kcalloc(n, sizeof(struct ctl_table), GFP_KERNEL); |
e692ab53 | 6444 | |
e692ab53 NP |
6445 | return entry; |
6446 | } | |
6447 | ||
6382bc90 MM |
6448 | static void sd_free_ctl_entry(struct ctl_table **tablep) |
6449 | { | |
cd790076 | 6450 | struct ctl_table *entry; |
6382bc90 | 6451 | |
cd790076 MM |
6452 | /* |
6453 | * In the intermediate directories, both the child directory and | |
6454 | * procname are dynamically allocated and could fail but the mode | |
41a2d6cf | 6455 | * will always be set. In the lowest directory the names are |
cd790076 MM |
6456 | * static strings and all have proc handlers. |
6457 | */ | |
6458 | for (entry = *tablep; entry->mode; entry++) { | |
6382bc90 MM |
6459 | if (entry->child) |
6460 | sd_free_ctl_entry(&entry->child); | |
cd790076 MM |
6461 | if (entry->proc_handler == NULL) |
6462 | kfree(entry->procname); | |
6463 | } | |
6382bc90 MM |
6464 | |
6465 | kfree(*tablep); | |
6466 | *tablep = NULL; | |
6467 | } | |
6468 | ||
e692ab53 | 6469 | static void |
e0361851 | 6470 | set_table_entry(struct ctl_table *entry, |
e692ab53 NP |
6471 | const char *procname, void *data, int maxlen, |
6472 | mode_t mode, proc_handler *proc_handler) | |
6473 | { | |
e692ab53 NP |
6474 | entry->procname = procname; |
6475 | entry->data = data; | |
6476 | entry->maxlen = maxlen; | |
6477 | entry->mode = mode; | |
6478 | entry->proc_handler = proc_handler; | |
6479 | } | |
6480 | ||
6481 | static struct ctl_table * | |
6482 | sd_alloc_ctl_domain_table(struct sched_domain *sd) | |
6483 | { | |
a5d8c348 | 6484 | struct ctl_table *table = sd_alloc_ctl_entry(13); |
e692ab53 | 6485 | |
ad1cdc1d MM |
6486 | if (table == NULL) |
6487 | return NULL; | |
6488 | ||
e0361851 | 6489 | set_table_entry(&table[0], "min_interval", &sd->min_interval, |
e692ab53 | 6490 | sizeof(long), 0644, proc_doulongvec_minmax); |
e0361851 | 6491 | set_table_entry(&table[1], "max_interval", &sd->max_interval, |
e692ab53 | 6492 | sizeof(long), 0644, proc_doulongvec_minmax); |
e0361851 | 6493 | set_table_entry(&table[2], "busy_idx", &sd->busy_idx, |
e692ab53 | 6494 | sizeof(int), 0644, proc_dointvec_minmax); |
e0361851 | 6495 | set_table_entry(&table[3], "idle_idx", &sd->idle_idx, |
e692ab53 | 6496 | sizeof(int), 0644, proc_dointvec_minmax); |
e0361851 | 6497 | set_table_entry(&table[4], "newidle_idx", &sd->newidle_idx, |
e692ab53 | 6498 | sizeof(int), 0644, proc_dointvec_minmax); |
e0361851 | 6499 | set_table_entry(&table[5], "wake_idx", &sd->wake_idx, |
e692ab53 | 6500 | sizeof(int), 0644, proc_dointvec_minmax); |
e0361851 | 6501 | set_table_entry(&table[6], "forkexec_idx", &sd->forkexec_idx, |
e692ab53 | 6502 | sizeof(int), 0644, proc_dointvec_minmax); |
e0361851 | 6503 | set_table_entry(&table[7], "busy_factor", &sd->busy_factor, |
e692ab53 | 6504 | sizeof(int), 0644, proc_dointvec_minmax); |
e0361851 | 6505 | set_table_entry(&table[8], "imbalance_pct", &sd->imbalance_pct, |
e692ab53 | 6506 | sizeof(int), 0644, proc_dointvec_minmax); |
ace8b3d6 | 6507 | set_table_entry(&table[9], "cache_nice_tries", |
e692ab53 NP |
6508 | &sd->cache_nice_tries, |
6509 | sizeof(int), 0644, proc_dointvec_minmax); | |
ace8b3d6 | 6510 | set_table_entry(&table[10], "flags", &sd->flags, |
e692ab53 | 6511 | sizeof(int), 0644, proc_dointvec_minmax); |
a5d8c348 IM |
6512 | set_table_entry(&table[11], "name", sd->name, |
6513 | CORENAME_MAX_SIZE, 0444, proc_dostring); | |
6514 | /* &table[12] is terminator */ | |
e692ab53 NP |
6515 | |
6516 | return table; | |
6517 | } | |
6518 | ||
9a4e7159 | 6519 | static ctl_table *sd_alloc_ctl_cpu_table(int cpu) |
e692ab53 NP |
6520 | { |
6521 | struct ctl_table *entry, *table; | |
6522 | struct sched_domain *sd; | |
6523 | int domain_num = 0, i; | |
6524 | char buf[32]; | |
6525 | ||
6526 | for_each_domain(cpu, sd) | |
6527 | domain_num++; | |
6528 | entry = table = sd_alloc_ctl_entry(domain_num + 1); | |
ad1cdc1d MM |
6529 | if (table == NULL) |
6530 | return NULL; | |
e692ab53 NP |
6531 | |
6532 | i = 0; | |
6533 | for_each_domain(cpu, sd) { | |
6534 | snprintf(buf, 32, "domain%d", i); | |
e692ab53 | 6535 | entry->procname = kstrdup(buf, GFP_KERNEL); |
c57baf1e | 6536 | entry->mode = 0555; |
e692ab53 NP |
6537 | entry->child = sd_alloc_ctl_domain_table(sd); |
6538 | entry++; | |
6539 | i++; | |
6540 | } | |
6541 | return table; | |
6542 | } | |
6543 | ||
6544 | static struct ctl_table_header *sd_sysctl_header; | |
6382bc90 | 6545 | static void register_sched_domain_sysctl(void) |
e692ab53 | 6546 | { |
6ad4c188 | 6547 | int i, cpu_num = num_possible_cpus(); |
e692ab53 NP |
6548 | struct ctl_table *entry = sd_alloc_ctl_entry(cpu_num + 1); |
6549 | char buf[32]; | |
6550 | ||
7378547f MM |
6551 | WARN_ON(sd_ctl_dir[0].child); |
6552 | sd_ctl_dir[0].child = entry; | |
6553 | ||
ad1cdc1d MM |
6554 | if (entry == NULL) |
6555 | return; | |
6556 | ||
6ad4c188 | 6557 | for_each_possible_cpu(i) { |
e692ab53 | 6558 | snprintf(buf, 32, "cpu%d", i); |
e692ab53 | 6559 | entry->procname = kstrdup(buf, GFP_KERNEL); |
c57baf1e | 6560 | entry->mode = 0555; |
e692ab53 | 6561 | entry->child = sd_alloc_ctl_cpu_table(i); |
97b6ea7b | 6562 | entry++; |
e692ab53 | 6563 | } |
7378547f MM |
6564 | |
6565 | WARN_ON(sd_sysctl_header); | |
e692ab53 NP |
6566 | sd_sysctl_header = register_sysctl_table(sd_ctl_root); |
6567 | } | |
6382bc90 | 6568 | |
7378547f | 6569 | /* may be called multiple times per register */ |
6382bc90 MM |
6570 | static void unregister_sched_domain_sysctl(void) |
6571 | { | |
7378547f MM |
6572 | if (sd_sysctl_header) |
6573 | unregister_sysctl_table(sd_sysctl_header); | |
6382bc90 | 6574 | sd_sysctl_header = NULL; |
7378547f MM |
6575 | if (sd_ctl_dir[0].child) |
6576 | sd_free_ctl_entry(&sd_ctl_dir[0].child); | |
6382bc90 | 6577 | } |
e692ab53 | 6578 | #else |
6382bc90 MM |
6579 | static void register_sched_domain_sysctl(void) |
6580 | { | |
6581 | } | |
6582 | static void unregister_sched_domain_sysctl(void) | |
e692ab53 NP |
6583 | { |
6584 | } | |
6585 | #endif | |
6586 | ||
1f11eb6a GH |
6587 | static void set_rq_online(struct rq *rq) |
6588 | { | |
6589 | if (!rq->online) { | |
6590 | const struct sched_class *class; | |
6591 | ||
c6c4927b | 6592 | cpumask_set_cpu(rq->cpu, rq->rd->online); |
1f11eb6a GH |
6593 | rq->online = 1; |
6594 | ||
6595 | for_each_class(class) { | |
6596 | if (class->rq_online) | |
6597 | class->rq_online(rq); | |
6598 | } | |
6599 | } | |
6600 | } | |
6601 | ||
6602 | static void set_rq_offline(struct rq *rq) | |
6603 | { | |
6604 | if (rq->online) { | |
6605 | const struct sched_class *class; | |
6606 | ||
6607 | for_each_class(class) { | |
6608 | if (class->rq_offline) | |
6609 | class->rq_offline(rq); | |
6610 | } | |
6611 | ||
c6c4927b | 6612 | cpumask_clear_cpu(rq->cpu, rq->rd->online); |
1f11eb6a GH |
6613 | rq->online = 0; |
6614 | } | |
6615 | } | |
6616 | ||
1da177e4 LT |
6617 | /* |
6618 | * migration_call - callback that gets triggered when a CPU is added. | |
6619 | * Here we can start up the necessary migration thread for the new CPU. | |
6620 | */ | |
48f24c4d IM |
6621 | static int __cpuinit |
6622 | migration_call(struct notifier_block *nfb, unsigned long action, void *hcpu) | |
1da177e4 | 6623 | { |
48f24c4d | 6624 | int cpu = (long)hcpu; |
1da177e4 | 6625 | unsigned long flags; |
969c7921 | 6626 | struct rq *rq = cpu_rq(cpu); |
1da177e4 | 6627 | |
48c5ccae | 6628 | switch (action & ~CPU_TASKS_FROZEN) { |
5be9361c | 6629 | |
1da177e4 | 6630 | case CPU_UP_PREPARE: |
a468d389 | 6631 | rq->calc_load_update = calc_load_update; |
1da177e4 | 6632 | break; |
48f24c4d | 6633 | |
1da177e4 | 6634 | case CPU_ONLINE: |
1f94ef59 | 6635 | /* Update our root-domain */ |
05fa785c | 6636 | raw_spin_lock_irqsave(&rq->lock, flags); |
1f94ef59 | 6637 | if (rq->rd) { |
c6c4927b | 6638 | BUG_ON(!cpumask_test_cpu(cpu, rq->rd->span)); |
1f11eb6a GH |
6639 | |
6640 | set_rq_online(rq); | |
1f94ef59 | 6641 | } |
05fa785c | 6642 | raw_spin_unlock_irqrestore(&rq->lock, flags); |
1da177e4 | 6643 | break; |
48f24c4d | 6644 | |
1da177e4 | 6645 | #ifdef CONFIG_HOTPLUG_CPU |
08f503b0 | 6646 | case CPU_DYING: |
317f3941 | 6647 | sched_ttwu_pending(); |
57d885fe | 6648 | /* Update our root-domain */ |
05fa785c | 6649 | raw_spin_lock_irqsave(&rq->lock, flags); |
57d885fe | 6650 | if (rq->rd) { |
c6c4927b | 6651 | BUG_ON(!cpumask_test_cpu(cpu, rq->rd->span)); |
1f11eb6a | 6652 | set_rq_offline(rq); |
57d885fe | 6653 | } |
48c5ccae PZ |
6654 | migrate_tasks(cpu); |
6655 | BUG_ON(rq->nr_running != 1); /* the migration thread */ | |
05fa785c | 6656 | raw_spin_unlock_irqrestore(&rq->lock, flags); |
48c5ccae PZ |
6657 | |
6658 | migrate_nr_uninterruptible(rq); | |
6659 | calc_global_load_remove(rq); | |
57d885fe | 6660 | break; |
1da177e4 LT |
6661 | #endif |
6662 | } | |
49c022e6 PZ |
6663 | |
6664 | update_max_interval(); | |
6665 | ||
1da177e4 LT |
6666 | return NOTIFY_OK; |
6667 | } | |
6668 | ||
f38b0820 PM |
6669 | /* |
6670 | * Register at high priority so that task migration (migrate_all_tasks) | |
6671 | * happens before everything else. This has to be lower priority than | |
cdd6c482 | 6672 | * the notifier in the perf_event subsystem, though. |
1da177e4 | 6673 | */ |
26c2143b | 6674 | static struct notifier_block __cpuinitdata migration_notifier = { |
1da177e4 | 6675 | .notifier_call = migration_call, |
50a323b7 | 6676 | .priority = CPU_PRI_MIGRATION, |
1da177e4 LT |
6677 | }; |
6678 | ||
3a101d05 TH |
6679 | static int __cpuinit sched_cpu_active(struct notifier_block *nfb, |
6680 | unsigned long action, void *hcpu) | |
6681 | { | |
6682 | switch (action & ~CPU_TASKS_FROZEN) { | |
6683 | case CPU_ONLINE: | |
6684 | case CPU_DOWN_FAILED: | |
6685 | set_cpu_active((long)hcpu, true); | |
6686 | return NOTIFY_OK; | |
6687 | default: | |
6688 | return NOTIFY_DONE; | |
6689 | } | |
6690 | } | |
6691 | ||
6692 | static int __cpuinit sched_cpu_inactive(struct notifier_block *nfb, | |
6693 | unsigned long action, void *hcpu) | |
6694 | { | |
6695 | switch (action & ~CPU_TASKS_FROZEN) { | |
6696 | case CPU_DOWN_PREPARE: | |
6697 | set_cpu_active((long)hcpu, false); | |
6698 | return NOTIFY_OK; | |
6699 | default: | |
6700 | return NOTIFY_DONE; | |
6701 | } | |
6702 | } | |
6703 | ||
7babe8db | 6704 | static int __init migration_init(void) |
1da177e4 LT |
6705 | { |
6706 | void *cpu = (void *)(long)smp_processor_id(); | |
07dccf33 | 6707 | int err; |
48f24c4d | 6708 | |
3a101d05 | 6709 | /* Initialize migration for the boot CPU */ |
07dccf33 AM |
6710 | err = migration_call(&migration_notifier, CPU_UP_PREPARE, cpu); |
6711 | BUG_ON(err == NOTIFY_BAD); | |
1da177e4 LT |
6712 | migration_call(&migration_notifier, CPU_ONLINE, cpu); |
6713 | register_cpu_notifier(&migration_notifier); | |
7babe8db | 6714 | |
3a101d05 TH |
6715 | /* Register cpu active notifiers */ |
6716 | cpu_notifier(sched_cpu_active, CPU_PRI_SCHED_ACTIVE); | |
6717 | cpu_notifier(sched_cpu_inactive, CPU_PRI_SCHED_INACTIVE); | |
6718 | ||
a004cd42 | 6719 | return 0; |
1da177e4 | 6720 | } |
7babe8db | 6721 | early_initcall(migration_init); |
1da177e4 LT |
6722 | #endif |
6723 | ||
6724 | #ifdef CONFIG_SMP | |
476f3534 | 6725 | |
4cb98839 PZ |
6726 | static cpumask_var_t sched_domains_tmpmask; /* sched_domains_mutex */ |
6727 | ||
3e9830dc | 6728 | #ifdef CONFIG_SCHED_DEBUG |
4dcf6aff | 6729 | |
f6630114 MT |
6730 | static __read_mostly int sched_domain_debug_enabled; |
6731 | ||
6732 | static int __init sched_domain_debug_setup(char *str) | |
6733 | { | |
6734 | sched_domain_debug_enabled = 1; | |
6735 | ||
6736 | return 0; | |
6737 | } | |
6738 | early_param("sched_debug", sched_domain_debug_setup); | |
6739 | ||
7c16ec58 | 6740 | static int sched_domain_debug_one(struct sched_domain *sd, int cpu, int level, |
96f874e2 | 6741 | struct cpumask *groupmask) |
1da177e4 | 6742 | { |
4dcf6aff | 6743 | struct sched_group *group = sd->groups; |
434d53b0 | 6744 | char str[256]; |
1da177e4 | 6745 | |
968ea6d8 | 6746 | cpulist_scnprintf(str, sizeof(str), sched_domain_span(sd)); |
96f874e2 | 6747 | cpumask_clear(groupmask); |
4dcf6aff IM |
6748 | |
6749 | printk(KERN_DEBUG "%*s domain %d: ", level, "", level); | |
6750 | ||
6751 | if (!(sd->flags & SD_LOAD_BALANCE)) { | |
3df0fc5b | 6752 | printk("does not load-balance\n"); |
4dcf6aff | 6753 | if (sd->parent) |
3df0fc5b PZ |
6754 | printk(KERN_ERR "ERROR: !SD_LOAD_BALANCE domain" |
6755 | " has parent"); | |
4dcf6aff | 6756 | return -1; |
41c7ce9a NP |
6757 | } |
6758 | ||
3df0fc5b | 6759 | printk(KERN_CONT "span %s level %s\n", str, sd->name); |
4dcf6aff | 6760 | |
758b2cdc | 6761 | if (!cpumask_test_cpu(cpu, sched_domain_span(sd))) { |
3df0fc5b PZ |
6762 | printk(KERN_ERR "ERROR: domain->span does not contain " |
6763 | "CPU%d\n", cpu); | |
4dcf6aff | 6764 | } |
758b2cdc | 6765 | if (!cpumask_test_cpu(cpu, sched_group_cpus(group))) { |
3df0fc5b PZ |
6766 | printk(KERN_ERR "ERROR: domain->groups does not contain" |
6767 | " CPU%d\n", cpu); | |
4dcf6aff | 6768 | } |
1da177e4 | 6769 | |
4dcf6aff | 6770 | printk(KERN_DEBUG "%*s groups:", level + 1, ""); |
1da177e4 | 6771 | do { |
4dcf6aff | 6772 | if (!group) { |
3df0fc5b PZ |
6773 | printk("\n"); |
6774 | printk(KERN_ERR "ERROR: group is NULL\n"); | |
1da177e4 LT |
6775 | break; |
6776 | } | |
6777 | ||
9c3f75cb | 6778 | if (!group->sgp->power) { |
3df0fc5b PZ |
6779 | printk(KERN_CONT "\n"); |
6780 | printk(KERN_ERR "ERROR: domain->cpu_power not " | |
6781 | "set\n"); | |
4dcf6aff IM |
6782 | break; |
6783 | } | |
1da177e4 | 6784 | |
758b2cdc | 6785 | if (!cpumask_weight(sched_group_cpus(group))) { |
3df0fc5b PZ |
6786 | printk(KERN_CONT "\n"); |
6787 | printk(KERN_ERR "ERROR: empty group\n"); | |
4dcf6aff IM |
6788 | break; |
6789 | } | |
1da177e4 | 6790 | |
758b2cdc | 6791 | if (cpumask_intersects(groupmask, sched_group_cpus(group))) { |
3df0fc5b PZ |
6792 | printk(KERN_CONT "\n"); |
6793 | printk(KERN_ERR "ERROR: repeated CPUs\n"); | |
4dcf6aff IM |
6794 | break; |
6795 | } | |
1da177e4 | 6796 | |
758b2cdc | 6797 | cpumask_or(groupmask, groupmask, sched_group_cpus(group)); |
1da177e4 | 6798 | |
968ea6d8 | 6799 | cpulist_scnprintf(str, sizeof(str), sched_group_cpus(group)); |
381512cf | 6800 | |
3df0fc5b | 6801 | printk(KERN_CONT " %s", str); |
9c3f75cb | 6802 | if (group->sgp->power != SCHED_POWER_SCALE) { |
3df0fc5b | 6803 | printk(KERN_CONT " (cpu_power = %d)", |
9c3f75cb | 6804 | group->sgp->power); |
381512cf | 6805 | } |
1da177e4 | 6806 | |
4dcf6aff IM |
6807 | group = group->next; |
6808 | } while (group != sd->groups); | |
3df0fc5b | 6809 | printk(KERN_CONT "\n"); |
1da177e4 | 6810 | |
758b2cdc | 6811 | if (!cpumask_equal(sched_domain_span(sd), groupmask)) |
3df0fc5b | 6812 | printk(KERN_ERR "ERROR: groups don't span domain->span\n"); |
1da177e4 | 6813 | |
758b2cdc RR |
6814 | if (sd->parent && |
6815 | !cpumask_subset(groupmask, sched_domain_span(sd->parent))) | |
3df0fc5b PZ |
6816 | printk(KERN_ERR "ERROR: parent span is not a superset " |
6817 | "of domain->span\n"); | |
4dcf6aff IM |
6818 | return 0; |
6819 | } | |
1da177e4 | 6820 | |
4dcf6aff IM |
6821 | static void sched_domain_debug(struct sched_domain *sd, int cpu) |
6822 | { | |
6823 | int level = 0; | |
1da177e4 | 6824 | |
f6630114 MT |
6825 | if (!sched_domain_debug_enabled) |
6826 | return; | |
6827 | ||
4dcf6aff IM |
6828 | if (!sd) { |
6829 | printk(KERN_DEBUG "CPU%d attaching NULL sched-domain.\n", cpu); | |
6830 | return; | |
6831 | } | |
1da177e4 | 6832 | |
4dcf6aff IM |
6833 | printk(KERN_DEBUG "CPU%d attaching sched-domain:\n", cpu); |
6834 | ||
6835 | for (;;) { | |
4cb98839 | 6836 | if (sched_domain_debug_one(sd, cpu, level, sched_domains_tmpmask)) |
4dcf6aff | 6837 | break; |
1da177e4 LT |
6838 | level++; |
6839 | sd = sd->parent; | |
33859f7f | 6840 | if (!sd) |
4dcf6aff IM |
6841 | break; |
6842 | } | |
1da177e4 | 6843 | } |
6d6bc0ad | 6844 | #else /* !CONFIG_SCHED_DEBUG */ |
48f24c4d | 6845 | # define sched_domain_debug(sd, cpu) do { } while (0) |
6d6bc0ad | 6846 | #endif /* CONFIG_SCHED_DEBUG */ |
1da177e4 | 6847 | |
1a20ff27 | 6848 | static int sd_degenerate(struct sched_domain *sd) |
245af2c7 | 6849 | { |
758b2cdc | 6850 | if (cpumask_weight(sched_domain_span(sd)) == 1) |
245af2c7 SS |
6851 | return 1; |
6852 | ||
6853 | /* Following flags need at least 2 groups */ | |
6854 | if (sd->flags & (SD_LOAD_BALANCE | | |
6855 | SD_BALANCE_NEWIDLE | | |
6856 | SD_BALANCE_FORK | | |
89c4710e SS |
6857 | SD_BALANCE_EXEC | |
6858 | SD_SHARE_CPUPOWER | | |
6859 | SD_SHARE_PKG_RESOURCES)) { | |
245af2c7 SS |
6860 | if (sd->groups != sd->groups->next) |
6861 | return 0; | |
6862 | } | |
6863 | ||
6864 | /* Following flags don't use groups */ | |
c88d5910 | 6865 | if (sd->flags & (SD_WAKE_AFFINE)) |
245af2c7 SS |
6866 | return 0; |
6867 | ||
6868 | return 1; | |
6869 | } | |
6870 | ||
48f24c4d IM |
6871 | static int |
6872 | sd_parent_degenerate(struct sched_domain *sd, struct sched_domain *parent) | |
245af2c7 SS |
6873 | { |
6874 | unsigned long cflags = sd->flags, pflags = parent->flags; | |
6875 | ||
6876 | if (sd_degenerate(parent)) | |
6877 | return 1; | |
6878 | ||
758b2cdc | 6879 | if (!cpumask_equal(sched_domain_span(sd), sched_domain_span(parent))) |
245af2c7 SS |
6880 | return 0; |
6881 | ||
245af2c7 SS |
6882 | /* Flags needing groups don't count if only 1 group in parent */ |
6883 | if (parent->groups == parent->groups->next) { | |
6884 | pflags &= ~(SD_LOAD_BALANCE | | |
6885 | SD_BALANCE_NEWIDLE | | |
6886 | SD_BALANCE_FORK | | |
89c4710e SS |
6887 | SD_BALANCE_EXEC | |
6888 | SD_SHARE_CPUPOWER | | |
6889 | SD_SHARE_PKG_RESOURCES); | |
5436499e KC |
6890 | if (nr_node_ids == 1) |
6891 | pflags &= ~SD_SERIALIZE; | |
245af2c7 SS |
6892 | } |
6893 | if (~cflags & pflags) | |
6894 | return 0; | |
6895 | ||
6896 | return 1; | |
6897 | } | |
6898 | ||
dce840a0 | 6899 | static void free_rootdomain(struct rcu_head *rcu) |
c6c4927b | 6900 | { |
dce840a0 | 6901 | struct root_domain *rd = container_of(rcu, struct root_domain, rcu); |
047106ad | 6902 | |
68e74568 | 6903 | cpupri_cleanup(&rd->cpupri); |
c6c4927b RR |
6904 | free_cpumask_var(rd->rto_mask); |
6905 | free_cpumask_var(rd->online); | |
6906 | free_cpumask_var(rd->span); | |
6907 | kfree(rd); | |
6908 | } | |
6909 | ||
57d885fe GH |
6910 | static void rq_attach_root(struct rq *rq, struct root_domain *rd) |
6911 | { | |
a0490fa3 | 6912 | struct root_domain *old_rd = NULL; |
57d885fe | 6913 | unsigned long flags; |
57d885fe | 6914 | |
05fa785c | 6915 | raw_spin_lock_irqsave(&rq->lock, flags); |
57d885fe GH |
6916 | |
6917 | if (rq->rd) { | |
a0490fa3 | 6918 | old_rd = rq->rd; |
57d885fe | 6919 | |
c6c4927b | 6920 | if (cpumask_test_cpu(rq->cpu, old_rd->online)) |
1f11eb6a | 6921 | set_rq_offline(rq); |
57d885fe | 6922 | |
c6c4927b | 6923 | cpumask_clear_cpu(rq->cpu, old_rd->span); |
dc938520 | 6924 | |
a0490fa3 IM |
6925 | /* |
6926 | * If we dont want to free the old_rt yet then | |
6927 | * set old_rd to NULL to skip the freeing later | |
6928 | * in this function: | |
6929 | */ | |
6930 | if (!atomic_dec_and_test(&old_rd->refcount)) | |
6931 | old_rd = NULL; | |
57d885fe GH |
6932 | } |
6933 | ||
6934 | atomic_inc(&rd->refcount); | |
6935 | rq->rd = rd; | |
6936 | ||
c6c4927b | 6937 | cpumask_set_cpu(rq->cpu, rd->span); |
00aec93d | 6938 | if (cpumask_test_cpu(rq->cpu, cpu_active_mask)) |
1f11eb6a | 6939 | set_rq_online(rq); |
57d885fe | 6940 | |
05fa785c | 6941 | raw_spin_unlock_irqrestore(&rq->lock, flags); |
a0490fa3 IM |
6942 | |
6943 | if (old_rd) | |
dce840a0 | 6944 | call_rcu_sched(&old_rd->rcu, free_rootdomain); |
57d885fe GH |
6945 | } |
6946 | ||
68c38fc3 | 6947 | static int init_rootdomain(struct root_domain *rd) |
57d885fe GH |
6948 | { |
6949 | memset(rd, 0, sizeof(*rd)); | |
6950 | ||
68c38fc3 | 6951 | if (!alloc_cpumask_var(&rd->span, GFP_KERNEL)) |
0c910d28 | 6952 | goto out; |
68c38fc3 | 6953 | if (!alloc_cpumask_var(&rd->online, GFP_KERNEL)) |
c6c4927b | 6954 | goto free_span; |
68c38fc3 | 6955 | if (!alloc_cpumask_var(&rd->rto_mask, GFP_KERNEL)) |
c6c4927b | 6956 | goto free_online; |
6e0534f2 | 6957 | |
68c38fc3 | 6958 | if (cpupri_init(&rd->cpupri) != 0) |
68e74568 | 6959 | goto free_rto_mask; |
c6c4927b | 6960 | return 0; |
6e0534f2 | 6961 | |
68e74568 RR |
6962 | free_rto_mask: |
6963 | free_cpumask_var(rd->rto_mask); | |
c6c4927b RR |
6964 | free_online: |
6965 | free_cpumask_var(rd->online); | |
6966 | free_span: | |
6967 | free_cpumask_var(rd->span); | |
0c910d28 | 6968 | out: |
c6c4927b | 6969 | return -ENOMEM; |
57d885fe GH |
6970 | } |
6971 | ||
6972 | static void init_defrootdomain(void) | |
6973 | { | |
68c38fc3 | 6974 | init_rootdomain(&def_root_domain); |
c6c4927b | 6975 | |
57d885fe GH |
6976 | atomic_set(&def_root_domain.refcount, 1); |
6977 | } | |
6978 | ||
dc938520 | 6979 | static struct root_domain *alloc_rootdomain(void) |
57d885fe GH |
6980 | { |
6981 | struct root_domain *rd; | |
6982 | ||
6983 | rd = kmalloc(sizeof(*rd), GFP_KERNEL); | |
6984 | if (!rd) | |
6985 | return NULL; | |
6986 | ||
68c38fc3 | 6987 | if (init_rootdomain(rd) != 0) { |
c6c4927b RR |
6988 | kfree(rd); |
6989 | return NULL; | |
6990 | } | |
57d885fe GH |
6991 | |
6992 | return rd; | |
6993 | } | |
6994 | ||
e3589f6c PZ |
6995 | static void free_sched_groups(struct sched_group *sg, int free_sgp) |
6996 | { | |
6997 | struct sched_group *tmp, *first; | |
6998 | ||
6999 | if (!sg) | |
7000 | return; | |
7001 | ||
7002 | first = sg; | |
7003 | do { | |
7004 | tmp = sg->next; | |
7005 | ||
7006 | if (free_sgp && atomic_dec_and_test(&sg->sgp->ref)) | |
7007 | kfree(sg->sgp); | |
7008 | ||
7009 | kfree(sg); | |
7010 | sg = tmp; | |
7011 | } while (sg != first); | |
7012 | } | |
7013 | ||
dce840a0 PZ |
7014 | static void free_sched_domain(struct rcu_head *rcu) |
7015 | { | |
7016 | struct sched_domain *sd = container_of(rcu, struct sched_domain, rcu); | |
e3589f6c PZ |
7017 | |
7018 | /* | |
7019 | * If its an overlapping domain it has private groups, iterate and | |
7020 | * nuke them all. | |
7021 | */ | |
7022 | if (sd->flags & SD_OVERLAP) { | |
7023 | free_sched_groups(sd->groups, 1); | |
7024 | } else if (atomic_dec_and_test(&sd->groups->ref)) { | |
9c3f75cb | 7025 | kfree(sd->groups->sgp); |
dce840a0 | 7026 | kfree(sd->groups); |
9c3f75cb | 7027 | } |
dce840a0 PZ |
7028 | kfree(sd); |
7029 | } | |
7030 | ||
7031 | static void destroy_sched_domain(struct sched_domain *sd, int cpu) | |
7032 | { | |
7033 | call_rcu(&sd->rcu, free_sched_domain); | |
7034 | } | |
7035 | ||
7036 | static void destroy_sched_domains(struct sched_domain *sd, int cpu) | |
7037 | { | |
7038 | for (; sd; sd = sd->parent) | |
7039 | destroy_sched_domain(sd, cpu); | |
7040 | } | |
7041 | ||
1da177e4 | 7042 | /* |
0eab9146 | 7043 | * Attach the domain 'sd' to 'cpu' as its base domain. Callers must |
1da177e4 LT |
7044 | * hold the hotplug lock. |
7045 | */ | |
0eab9146 IM |
7046 | static void |
7047 | cpu_attach_domain(struct sched_domain *sd, struct root_domain *rd, int cpu) | |
1da177e4 | 7048 | { |
70b97a7f | 7049 | struct rq *rq = cpu_rq(cpu); |
245af2c7 SS |
7050 | struct sched_domain *tmp; |
7051 | ||
7052 | /* Remove the sched domains which do not contribute to scheduling. */ | |
f29c9b1c | 7053 | for (tmp = sd; tmp; ) { |
245af2c7 SS |
7054 | struct sched_domain *parent = tmp->parent; |
7055 | if (!parent) | |
7056 | break; | |
f29c9b1c | 7057 | |
1a848870 | 7058 | if (sd_parent_degenerate(tmp, parent)) { |
245af2c7 | 7059 | tmp->parent = parent->parent; |
1a848870 SS |
7060 | if (parent->parent) |
7061 | parent->parent->child = tmp; | |
dce840a0 | 7062 | destroy_sched_domain(parent, cpu); |
f29c9b1c LZ |
7063 | } else |
7064 | tmp = tmp->parent; | |
245af2c7 SS |
7065 | } |
7066 | ||
1a848870 | 7067 | if (sd && sd_degenerate(sd)) { |
dce840a0 | 7068 | tmp = sd; |
245af2c7 | 7069 | sd = sd->parent; |
dce840a0 | 7070 | destroy_sched_domain(tmp, cpu); |
1a848870 SS |
7071 | if (sd) |
7072 | sd->child = NULL; | |
7073 | } | |
1da177e4 | 7074 | |
4cb98839 | 7075 | sched_domain_debug(sd, cpu); |
1da177e4 | 7076 | |
57d885fe | 7077 | rq_attach_root(rq, rd); |
dce840a0 | 7078 | tmp = rq->sd; |
674311d5 | 7079 | rcu_assign_pointer(rq->sd, sd); |
dce840a0 | 7080 | destroy_sched_domains(tmp, cpu); |
1da177e4 LT |
7081 | } |
7082 | ||
7083 | /* cpus with isolated domains */ | |
dcc30a35 | 7084 | static cpumask_var_t cpu_isolated_map; |
1da177e4 LT |
7085 | |
7086 | /* Setup the mask of cpus configured for isolated domains */ | |
7087 | static int __init isolated_cpu_setup(char *str) | |
7088 | { | |
bdddd296 | 7089 | alloc_bootmem_cpumask_var(&cpu_isolated_map); |
968ea6d8 | 7090 | cpulist_parse(str, cpu_isolated_map); |
1da177e4 LT |
7091 | return 1; |
7092 | } | |
7093 | ||
8927f494 | 7094 | __setup("isolcpus=", isolated_cpu_setup); |
1da177e4 | 7095 | |
9c1cfda2 | 7096 | #ifdef CONFIG_NUMA |
198e2f18 | 7097 | |
9c1cfda2 JH |
7098 | /** |
7099 | * find_next_best_node - find the next node to include in a sched_domain | |
7100 | * @node: node whose sched_domain we're building | |
7101 | * @used_nodes: nodes already in the sched_domain | |
7102 | * | |
41a2d6cf | 7103 | * Find the next node to include in a given scheduling domain. Simply |
9c1cfda2 JH |
7104 | * finds the closest node not already in the @used_nodes map. |
7105 | * | |
7106 | * Should use nodemask_t. | |
7107 | */ | |
c5f59f08 | 7108 | static int find_next_best_node(int node, nodemask_t *used_nodes) |
9c1cfda2 | 7109 | { |
7142d17e | 7110 | int i, n, val, min_val, best_node = -1; |
9c1cfda2 JH |
7111 | |
7112 | min_val = INT_MAX; | |
7113 | ||
076ac2af | 7114 | for (i = 0; i < nr_node_ids; i++) { |
9c1cfda2 | 7115 | /* Start at @node */ |
076ac2af | 7116 | n = (node + i) % nr_node_ids; |
9c1cfda2 JH |
7117 | |
7118 | if (!nr_cpus_node(n)) | |
7119 | continue; | |
7120 | ||
7121 | /* Skip already used nodes */ | |
c5f59f08 | 7122 | if (node_isset(n, *used_nodes)) |
9c1cfda2 JH |
7123 | continue; |
7124 | ||
7125 | /* Simple min distance search */ | |
7126 | val = node_distance(node, n); | |
7127 | ||
7128 | if (val < min_val) { | |
7129 | min_val = val; | |
7130 | best_node = n; | |
7131 | } | |
7132 | } | |
7133 | ||
7142d17e HD |
7134 | if (best_node != -1) |
7135 | node_set(best_node, *used_nodes); | |
9c1cfda2 JH |
7136 | return best_node; |
7137 | } | |
7138 | ||
7139 | /** | |
7140 | * sched_domain_node_span - get a cpumask for a node's sched_domain | |
7141 | * @node: node whose cpumask we're constructing | |
73486722 | 7142 | * @span: resulting cpumask |
9c1cfda2 | 7143 | * |
41a2d6cf | 7144 | * Given a node, construct a good cpumask for its sched_domain to span. It |
9c1cfda2 JH |
7145 | * should be one that prevents unnecessary balancing, but also spreads tasks |
7146 | * out optimally. | |
7147 | */ | |
96f874e2 | 7148 | static void sched_domain_node_span(int node, struct cpumask *span) |
9c1cfda2 | 7149 | { |
c5f59f08 | 7150 | nodemask_t used_nodes; |
48f24c4d | 7151 | int i; |
9c1cfda2 | 7152 | |
6ca09dfc | 7153 | cpumask_clear(span); |
c5f59f08 | 7154 | nodes_clear(used_nodes); |
9c1cfda2 | 7155 | |
6ca09dfc | 7156 | cpumask_or(span, span, cpumask_of_node(node)); |
c5f59f08 | 7157 | node_set(node, used_nodes); |
9c1cfda2 JH |
7158 | |
7159 | for (i = 1; i < SD_NODES_PER_DOMAIN; i++) { | |
c5f59f08 | 7160 | int next_node = find_next_best_node(node, &used_nodes); |
7142d17e HD |
7161 | if (next_node < 0) |
7162 | break; | |
6ca09dfc | 7163 | cpumask_or(span, span, cpumask_of_node(next_node)); |
9c1cfda2 | 7164 | } |
9c1cfda2 | 7165 | } |
d3081f52 PZ |
7166 | |
7167 | static const struct cpumask *cpu_node_mask(int cpu) | |
7168 | { | |
7169 | lockdep_assert_held(&sched_domains_mutex); | |
7170 | ||
7171 | sched_domain_node_span(cpu_to_node(cpu), sched_domains_tmpmask); | |
7172 | ||
7173 | return sched_domains_tmpmask; | |
7174 | } | |
2c402dc3 PZ |
7175 | |
7176 | static const struct cpumask *cpu_allnodes_mask(int cpu) | |
7177 | { | |
7178 | return cpu_possible_mask; | |
7179 | } | |
6d6bc0ad | 7180 | #endif /* CONFIG_NUMA */ |
9c1cfda2 | 7181 | |
d3081f52 PZ |
7182 | static const struct cpumask *cpu_cpu_mask(int cpu) |
7183 | { | |
7184 | return cpumask_of_node(cpu_to_node(cpu)); | |
7185 | } | |
7186 | ||
5c45bf27 | 7187 | int sched_smt_power_savings = 0, sched_mc_power_savings = 0; |
48f24c4d | 7188 | |
dce840a0 PZ |
7189 | struct sd_data { |
7190 | struct sched_domain **__percpu sd; | |
7191 | struct sched_group **__percpu sg; | |
9c3f75cb | 7192 | struct sched_group_power **__percpu sgp; |
dce840a0 PZ |
7193 | }; |
7194 | ||
49a02c51 | 7195 | struct s_data { |
21d42ccf | 7196 | struct sched_domain ** __percpu sd; |
49a02c51 AH |
7197 | struct root_domain *rd; |
7198 | }; | |
7199 | ||
2109b99e | 7200 | enum s_alloc { |
2109b99e | 7201 | sa_rootdomain, |
21d42ccf | 7202 | sa_sd, |
dce840a0 | 7203 | sa_sd_storage, |
2109b99e AH |
7204 | sa_none, |
7205 | }; | |
7206 | ||
54ab4ff4 PZ |
7207 | struct sched_domain_topology_level; |
7208 | ||
7209 | typedef struct sched_domain *(*sched_domain_init_f)(struct sched_domain_topology_level *tl, int cpu); | |
eb7a74e6 PZ |
7210 | typedef const struct cpumask *(*sched_domain_mask_f)(int cpu); |
7211 | ||
e3589f6c PZ |
7212 | #define SDTL_OVERLAP 0x01 |
7213 | ||
eb7a74e6 | 7214 | struct sched_domain_topology_level { |
2c402dc3 PZ |
7215 | sched_domain_init_f init; |
7216 | sched_domain_mask_f mask; | |
e3589f6c | 7217 | int flags; |
54ab4ff4 | 7218 | struct sd_data data; |
eb7a74e6 PZ |
7219 | }; |
7220 | ||
e3589f6c PZ |
7221 | static int |
7222 | build_overlap_sched_groups(struct sched_domain *sd, int cpu) | |
7223 | { | |
7224 | struct sched_group *first = NULL, *last = NULL, *groups = NULL, *sg; | |
7225 | const struct cpumask *span = sched_domain_span(sd); | |
7226 | struct cpumask *covered = sched_domains_tmpmask; | |
7227 | struct sd_data *sdd = sd->private; | |
7228 | struct sched_domain *child; | |
7229 | int i; | |
7230 | ||
7231 | cpumask_clear(covered); | |
7232 | ||
7233 | for_each_cpu(i, span) { | |
7234 | struct cpumask *sg_span; | |
7235 | ||
7236 | if (cpumask_test_cpu(i, covered)) | |
7237 | continue; | |
7238 | ||
7239 | sg = kzalloc_node(sizeof(struct sched_group) + cpumask_size(), | |
7240 | GFP_KERNEL, cpu_to_node(i)); | |
7241 | ||
7242 | if (!sg) | |
7243 | goto fail; | |
7244 | ||
7245 | sg_span = sched_group_cpus(sg); | |
7246 | ||
7247 | child = *per_cpu_ptr(sdd->sd, i); | |
7248 | if (child->child) { | |
7249 | child = child->child; | |
7250 | cpumask_copy(sg_span, sched_domain_span(child)); | |
7251 | } else | |
7252 | cpumask_set_cpu(i, sg_span); | |
7253 | ||
7254 | cpumask_or(covered, covered, sg_span); | |
7255 | ||
7256 | sg->sgp = *per_cpu_ptr(sdd->sgp, cpumask_first(sg_span)); | |
7257 | atomic_inc(&sg->sgp->ref); | |
7258 | ||
7259 | if (cpumask_test_cpu(cpu, sg_span)) | |
7260 | groups = sg; | |
7261 | ||
7262 | if (!first) | |
7263 | first = sg; | |
7264 | if (last) | |
7265 | last->next = sg; | |
7266 | last = sg; | |
7267 | last->next = first; | |
7268 | } | |
7269 | sd->groups = groups; | |
7270 | ||
7271 | return 0; | |
7272 | ||
7273 | fail: | |
7274 | free_sched_groups(first, 0); | |
7275 | ||
7276 | return -ENOMEM; | |
7277 | } | |
7278 | ||
dce840a0 | 7279 | static int get_group(int cpu, struct sd_data *sdd, struct sched_group **sg) |
1da177e4 | 7280 | { |
dce840a0 PZ |
7281 | struct sched_domain *sd = *per_cpu_ptr(sdd->sd, cpu); |
7282 | struct sched_domain *child = sd->child; | |
1da177e4 | 7283 | |
dce840a0 PZ |
7284 | if (child) |
7285 | cpu = cpumask_first(sched_domain_span(child)); | |
1e9f28fa | 7286 | |
9c3f75cb | 7287 | if (sg) { |
dce840a0 | 7288 | *sg = *per_cpu_ptr(sdd->sg, cpu); |
9c3f75cb | 7289 | (*sg)->sgp = *per_cpu_ptr(sdd->sgp, cpu); |
e3589f6c | 7290 | atomic_set(&(*sg)->sgp->ref, 1); /* for claim_allocations */ |
9c3f75cb | 7291 | } |
dce840a0 PZ |
7292 | |
7293 | return cpu; | |
1e9f28fa | 7294 | } |
1e9f28fa | 7295 | |
01a08546 | 7296 | /* |
dce840a0 PZ |
7297 | * build_sched_groups will build a circular linked list of the groups |
7298 | * covered by the given span, and will set each group's ->cpumask correctly, | |
7299 | * and ->cpu_power to 0. | |
e3589f6c PZ |
7300 | * |
7301 | * Assumes the sched_domain tree is fully constructed | |
01a08546 | 7302 | */ |
e3589f6c PZ |
7303 | static int |
7304 | build_sched_groups(struct sched_domain *sd, int cpu) | |
1da177e4 | 7305 | { |
dce840a0 PZ |
7306 | struct sched_group *first = NULL, *last = NULL; |
7307 | struct sd_data *sdd = sd->private; | |
7308 | const struct cpumask *span = sched_domain_span(sd); | |
f96225fd | 7309 | struct cpumask *covered; |
dce840a0 | 7310 | int i; |
9c1cfda2 | 7311 | |
e3589f6c PZ |
7312 | get_group(cpu, sdd, &sd->groups); |
7313 | atomic_inc(&sd->groups->ref); | |
7314 | ||
7315 | if (cpu != cpumask_first(sched_domain_span(sd))) | |
7316 | return 0; | |
7317 | ||
f96225fd PZ |
7318 | lockdep_assert_held(&sched_domains_mutex); |
7319 | covered = sched_domains_tmpmask; | |
7320 | ||
dce840a0 | 7321 | cpumask_clear(covered); |
6711cab4 | 7322 | |
dce840a0 PZ |
7323 | for_each_cpu(i, span) { |
7324 | struct sched_group *sg; | |
7325 | int group = get_group(i, sdd, &sg); | |
7326 | int j; | |
6711cab4 | 7327 | |
dce840a0 PZ |
7328 | if (cpumask_test_cpu(i, covered)) |
7329 | continue; | |
6711cab4 | 7330 | |
dce840a0 | 7331 | cpumask_clear(sched_group_cpus(sg)); |
9c3f75cb | 7332 | sg->sgp->power = 0; |
0601a88d | 7333 | |
dce840a0 PZ |
7334 | for_each_cpu(j, span) { |
7335 | if (get_group(j, sdd, NULL) != group) | |
7336 | continue; | |
0601a88d | 7337 | |
dce840a0 PZ |
7338 | cpumask_set_cpu(j, covered); |
7339 | cpumask_set_cpu(j, sched_group_cpus(sg)); | |
7340 | } | |
0601a88d | 7341 | |
dce840a0 PZ |
7342 | if (!first) |
7343 | first = sg; | |
7344 | if (last) | |
7345 | last->next = sg; | |
7346 | last = sg; | |
7347 | } | |
7348 | last->next = first; | |
e3589f6c PZ |
7349 | |
7350 | return 0; | |
0601a88d | 7351 | } |
51888ca2 | 7352 | |
89c4710e SS |
7353 | /* |
7354 | * Initialize sched groups cpu_power. | |
7355 | * | |
7356 | * cpu_power indicates the capacity of sched group, which is used while | |
7357 | * distributing the load between different sched groups in a sched domain. | |
7358 | * Typically cpu_power for all the groups in a sched domain will be same unless | |
7359 | * there are asymmetries in the topology. If there are asymmetries, group | |
7360 | * having more cpu_power will pickup more load compared to the group having | |
7361 | * less cpu_power. | |
89c4710e SS |
7362 | */ |
7363 | static void init_sched_groups_power(int cpu, struct sched_domain *sd) | |
7364 | { | |
e3589f6c | 7365 | struct sched_group *sg = sd->groups; |
89c4710e | 7366 | |
e3589f6c PZ |
7367 | WARN_ON(!sd || !sg); |
7368 | ||
7369 | do { | |
7370 | sg->group_weight = cpumask_weight(sched_group_cpus(sg)); | |
7371 | sg = sg->next; | |
7372 | } while (sg != sd->groups); | |
89c4710e | 7373 | |
e3589f6c PZ |
7374 | if (cpu != group_first_cpu(sg)) |
7375 | return; | |
aae6d3dd | 7376 | |
d274cb30 | 7377 | update_group_power(sd, cpu); |
89c4710e SS |
7378 | } |
7379 | ||
7c16ec58 MT |
7380 | /* |
7381 | * Initializers for schedule domains | |
7382 | * Non-inlined to reduce accumulated stack pressure in build_sched_domains() | |
7383 | */ | |
7384 | ||
a5d8c348 IM |
7385 | #ifdef CONFIG_SCHED_DEBUG |
7386 | # define SD_INIT_NAME(sd, type) sd->name = #type | |
7387 | #else | |
7388 | # define SD_INIT_NAME(sd, type) do { } while (0) | |
7389 | #endif | |
7390 | ||
54ab4ff4 PZ |
7391 | #define SD_INIT_FUNC(type) \ |
7392 | static noinline struct sched_domain * \ | |
7393 | sd_init_##type(struct sched_domain_topology_level *tl, int cpu) \ | |
7394 | { \ | |
7395 | struct sched_domain *sd = *per_cpu_ptr(tl->data.sd, cpu); \ | |
7396 | *sd = SD_##type##_INIT; \ | |
54ab4ff4 PZ |
7397 | SD_INIT_NAME(sd, type); \ |
7398 | sd->private = &tl->data; \ | |
7399 | return sd; \ | |
7c16ec58 MT |
7400 | } |
7401 | ||
7402 | SD_INIT_FUNC(CPU) | |
7403 | #ifdef CONFIG_NUMA | |
7404 | SD_INIT_FUNC(ALLNODES) | |
7405 | SD_INIT_FUNC(NODE) | |
7406 | #endif | |
7407 | #ifdef CONFIG_SCHED_SMT | |
7408 | SD_INIT_FUNC(SIBLING) | |
7409 | #endif | |
7410 | #ifdef CONFIG_SCHED_MC | |
7411 | SD_INIT_FUNC(MC) | |
7412 | #endif | |
01a08546 HC |
7413 | #ifdef CONFIG_SCHED_BOOK |
7414 | SD_INIT_FUNC(BOOK) | |
7415 | #endif | |
7c16ec58 | 7416 | |
1d3504fc | 7417 | static int default_relax_domain_level = -1; |
60495e77 | 7418 | int sched_domain_level_max; |
1d3504fc HS |
7419 | |
7420 | static int __init setup_relax_domain_level(char *str) | |
7421 | { | |
30e0e178 LZ |
7422 | unsigned long val; |
7423 | ||
7424 | val = simple_strtoul(str, NULL, 0); | |
60495e77 | 7425 | if (val < sched_domain_level_max) |
30e0e178 LZ |
7426 | default_relax_domain_level = val; |
7427 | ||
1d3504fc HS |
7428 | return 1; |
7429 | } | |
7430 | __setup("relax_domain_level=", setup_relax_domain_level); | |
7431 | ||
7432 | static void set_domain_attribute(struct sched_domain *sd, | |
7433 | struct sched_domain_attr *attr) | |
7434 | { | |
7435 | int request; | |
7436 | ||
7437 | if (!attr || attr->relax_domain_level < 0) { | |
7438 | if (default_relax_domain_level < 0) | |
7439 | return; | |
7440 | else | |
7441 | request = default_relax_domain_level; | |
7442 | } else | |
7443 | request = attr->relax_domain_level; | |
7444 | if (request < sd->level) { | |
7445 | /* turn off idle balance on this domain */ | |
c88d5910 | 7446 | sd->flags &= ~(SD_BALANCE_WAKE|SD_BALANCE_NEWIDLE); |
1d3504fc HS |
7447 | } else { |
7448 | /* turn on idle balance on this domain */ | |
c88d5910 | 7449 | sd->flags |= (SD_BALANCE_WAKE|SD_BALANCE_NEWIDLE); |
1d3504fc HS |
7450 | } |
7451 | } | |
7452 | ||
54ab4ff4 PZ |
7453 | static void __sdt_free(const struct cpumask *cpu_map); |
7454 | static int __sdt_alloc(const struct cpumask *cpu_map); | |
7455 | ||
2109b99e AH |
7456 | static void __free_domain_allocs(struct s_data *d, enum s_alloc what, |
7457 | const struct cpumask *cpu_map) | |
7458 | { | |
7459 | switch (what) { | |
2109b99e | 7460 | case sa_rootdomain: |
822ff793 PZ |
7461 | if (!atomic_read(&d->rd->refcount)) |
7462 | free_rootdomain(&d->rd->rcu); /* fall through */ | |
21d42ccf PZ |
7463 | case sa_sd: |
7464 | free_percpu(d->sd); /* fall through */ | |
dce840a0 | 7465 | case sa_sd_storage: |
54ab4ff4 | 7466 | __sdt_free(cpu_map); /* fall through */ |
2109b99e AH |
7467 | case sa_none: |
7468 | break; | |
7469 | } | |
7470 | } | |
3404c8d9 | 7471 | |
2109b99e AH |
7472 | static enum s_alloc __visit_domain_allocation_hell(struct s_data *d, |
7473 | const struct cpumask *cpu_map) | |
7474 | { | |
dce840a0 PZ |
7475 | memset(d, 0, sizeof(*d)); |
7476 | ||
54ab4ff4 PZ |
7477 | if (__sdt_alloc(cpu_map)) |
7478 | return sa_sd_storage; | |
dce840a0 PZ |
7479 | d->sd = alloc_percpu(struct sched_domain *); |
7480 | if (!d->sd) | |
7481 | return sa_sd_storage; | |
2109b99e | 7482 | d->rd = alloc_rootdomain(); |
dce840a0 | 7483 | if (!d->rd) |
21d42ccf | 7484 | return sa_sd; |
2109b99e AH |
7485 | return sa_rootdomain; |
7486 | } | |
57d885fe | 7487 | |
dce840a0 PZ |
7488 | /* |
7489 | * NULL the sd_data elements we've used to build the sched_domain and | |
7490 | * sched_group structure so that the subsequent __free_domain_allocs() | |
7491 | * will not free the data we're using. | |
7492 | */ | |
7493 | static void claim_allocations(int cpu, struct sched_domain *sd) | |
7494 | { | |
7495 | struct sd_data *sdd = sd->private; | |
dce840a0 PZ |
7496 | |
7497 | WARN_ON_ONCE(*per_cpu_ptr(sdd->sd, cpu) != sd); | |
7498 | *per_cpu_ptr(sdd->sd, cpu) = NULL; | |
7499 | ||
e3589f6c | 7500 | if (atomic_read(&(*per_cpu_ptr(sdd->sg, cpu))->ref)) |
dce840a0 | 7501 | *per_cpu_ptr(sdd->sg, cpu) = NULL; |
e3589f6c PZ |
7502 | |
7503 | if (atomic_read(&(*per_cpu_ptr(sdd->sgp, cpu))->ref)) | |
9c3f75cb | 7504 | *per_cpu_ptr(sdd->sgp, cpu) = NULL; |
dce840a0 PZ |
7505 | } |
7506 | ||
2c402dc3 PZ |
7507 | #ifdef CONFIG_SCHED_SMT |
7508 | static const struct cpumask *cpu_smt_mask(int cpu) | |
7f4588f3 | 7509 | { |
2c402dc3 | 7510 | return topology_thread_cpumask(cpu); |
3bd65a80 | 7511 | } |
2c402dc3 | 7512 | #endif |
7f4588f3 | 7513 | |
d069b916 PZ |
7514 | /* |
7515 | * Topology list, bottom-up. | |
7516 | */ | |
2c402dc3 | 7517 | static struct sched_domain_topology_level default_topology[] = { |
d069b916 PZ |
7518 | #ifdef CONFIG_SCHED_SMT |
7519 | { sd_init_SIBLING, cpu_smt_mask, }, | |
01a08546 | 7520 | #endif |
1e9f28fa | 7521 | #ifdef CONFIG_SCHED_MC |
2c402dc3 | 7522 | { sd_init_MC, cpu_coregroup_mask, }, |
1e9f28fa | 7523 | #endif |
d069b916 PZ |
7524 | #ifdef CONFIG_SCHED_BOOK |
7525 | { sd_init_BOOK, cpu_book_mask, }, | |
7526 | #endif | |
7527 | { sd_init_CPU, cpu_cpu_mask, }, | |
7528 | #ifdef CONFIG_NUMA | |
e3589f6c | 7529 | { sd_init_NODE, cpu_node_mask, SDTL_OVERLAP, }, |
d069b916 | 7530 | { sd_init_ALLNODES, cpu_allnodes_mask, }, |
1da177e4 | 7531 | #endif |
eb7a74e6 PZ |
7532 | { NULL, }, |
7533 | }; | |
7534 | ||
7535 | static struct sched_domain_topology_level *sched_domain_topology = default_topology; | |
7536 | ||
54ab4ff4 PZ |
7537 | static int __sdt_alloc(const struct cpumask *cpu_map) |
7538 | { | |
7539 | struct sched_domain_topology_level *tl; | |
7540 | int j; | |
7541 | ||
7542 | for (tl = sched_domain_topology; tl->init; tl++) { | |
7543 | struct sd_data *sdd = &tl->data; | |
7544 | ||
7545 | sdd->sd = alloc_percpu(struct sched_domain *); | |
7546 | if (!sdd->sd) | |
7547 | return -ENOMEM; | |
7548 | ||
7549 | sdd->sg = alloc_percpu(struct sched_group *); | |
7550 | if (!sdd->sg) | |
7551 | return -ENOMEM; | |
7552 | ||
9c3f75cb PZ |
7553 | sdd->sgp = alloc_percpu(struct sched_group_power *); |
7554 | if (!sdd->sgp) | |
7555 | return -ENOMEM; | |
7556 | ||
54ab4ff4 PZ |
7557 | for_each_cpu(j, cpu_map) { |
7558 | struct sched_domain *sd; | |
7559 | struct sched_group *sg; | |
9c3f75cb | 7560 | struct sched_group_power *sgp; |
54ab4ff4 PZ |
7561 | |
7562 | sd = kzalloc_node(sizeof(struct sched_domain) + cpumask_size(), | |
7563 | GFP_KERNEL, cpu_to_node(j)); | |
7564 | if (!sd) | |
7565 | return -ENOMEM; | |
7566 | ||
7567 | *per_cpu_ptr(sdd->sd, j) = sd; | |
7568 | ||
7569 | sg = kzalloc_node(sizeof(struct sched_group) + cpumask_size(), | |
7570 | GFP_KERNEL, cpu_to_node(j)); | |
7571 | if (!sg) | |
7572 | return -ENOMEM; | |
7573 | ||
7574 | *per_cpu_ptr(sdd->sg, j) = sg; | |
9c3f75cb PZ |
7575 | |
7576 | sgp = kzalloc_node(sizeof(struct sched_group_power), | |
7577 | GFP_KERNEL, cpu_to_node(j)); | |
7578 | if (!sgp) | |
7579 | return -ENOMEM; | |
7580 | ||
7581 | *per_cpu_ptr(sdd->sgp, j) = sgp; | |
54ab4ff4 PZ |
7582 | } |
7583 | } | |
7584 | ||
7585 | return 0; | |
7586 | } | |
7587 | ||
7588 | static void __sdt_free(const struct cpumask *cpu_map) | |
7589 | { | |
7590 | struct sched_domain_topology_level *tl; | |
7591 | int j; | |
7592 | ||
7593 | for (tl = sched_domain_topology; tl->init; tl++) { | |
7594 | struct sd_data *sdd = &tl->data; | |
7595 | ||
7596 | for_each_cpu(j, cpu_map) { | |
e3589f6c PZ |
7597 | struct sched_domain *sd = *per_cpu_ptr(sdd->sd, j); |
7598 | if (sd && (sd->flags & SD_OVERLAP)) | |
7599 | free_sched_groups(sd->groups, 0); | |
feff8fa0 | 7600 | kfree(*per_cpu_ptr(sdd->sd, j)); |
54ab4ff4 | 7601 | kfree(*per_cpu_ptr(sdd->sg, j)); |
9c3f75cb | 7602 | kfree(*per_cpu_ptr(sdd->sgp, j)); |
54ab4ff4 PZ |
7603 | } |
7604 | free_percpu(sdd->sd); | |
7605 | free_percpu(sdd->sg); | |
9c3f75cb | 7606 | free_percpu(sdd->sgp); |
54ab4ff4 PZ |
7607 | } |
7608 | } | |
7609 | ||
2c402dc3 PZ |
7610 | struct sched_domain *build_sched_domain(struct sched_domain_topology_level *tl, |
7611 | struct s_data *d, const struct cpumask *cpu_map, | |
d069b916 | 7612 | struct sched_domain_attr *attr, struct sched_domain *child, |
2c402dc3 PZ |
7613 | int cpu) |
7614 | { | |
54ab4ff4 | 7615 | struct sched_domain *sd = tl->init(tl, cpu); |
2c402dc3 | 7616 | if (!sd) |
d069b916 | 7617 | return child; |
2c402dc3 PZ |
7618 | |
7619 | set_domain_attribute(sd, attr); | |
7620 | cpumask_and(sched_domain_span(sd), cpu_map, tl->mask(cpu)); | |
60495e77 PZ |
7621 | if (child) { |
7622 | sd->level = child->level + 1; | |
7623 | sched_domain_level_max = max(sched_domain_level_max, sd->level); | |
d069b916 | 7624 | child->parent = sd; |
60495e77 | 7625 | } |
d069b916 | 7626 | sd->child = child; |
2c402dc3 PZ |
7627 | |
7628 | return sd; | |
7629 | } | |
7630 | ||
2109b99e AH |
7631 | /* |
7632 | * Build sched domains for a given set of cpus and attach the sched domains | |
7633 | * to the individual cpus | |
7634 | */ | |
dce840a0 PZ |
7635 | static int build_sched_domains(const struct cpumask *cpu_map, |
7636 | struct sched_domain_attr *attr) | |
2109b99e AH |
7637 | { |
7638 | enum s_alloc alloc_state = sa_none; | |
dce840a0 | 7639 | struct sched_domain *sd; |
2109b99e | 7640 | struct s_data d; |
822ff793 | 7641 | int i, ret = -ENOMEM; |
9c1cfda2 | 7642 | |
2109b99e AH |
7643 | alloc_state = __visit_domain_allocation_hell(&d, cpu_map); |
7644 | if (alloc_state != sa_rootdomain) | |
7645 | goto error; | |
9c1cfda2 | 7646 | |
dce840a0 | 7647 | /* Set up domains for cpus specified by the cpu_map. */ |
abcd083a | 7648 | for_each_cpu(i, cpu_map) { |
eb7a74e6 PZ |
7649 | struct sched_domain_topology_level *tl; |
7650 | ||
3bd65a80 | 7651 | sd = NULL; |
e3589f6c | 7652 | for (tl = sched_domain_topology; tl->init; tl++) { |
2c402dc3 | 7653 | sd = build_sched_domain(tl, &d, cpu_map, attr, sd, i); |
e3589f6c PZ |
7654 | if (tl->flags & SDTL_OVERLAP || sched_feat(FORCE_SD_OVERLAP)) |
7655 | sd->flags |= SD_OVERLAP; | |
d110235d PZ |
7656 | if (cpumask_equal(cpu_map, sched_domain_span(sd))) |
7657 | break; | |
e3589f6c | 7658 | } |
d274cb30 | 7659 | |
d069b916 PZ |
7660 | while (sd->child) |
7661 | sd = sd->child; | |
7662 | ||
21d42ccf | 7663 | *per_cpu_ptr(d.sd, i) = sd; |
dce840a0 PZ |
7664 | } |
7665 | ||
7666 | /* Build the groups for the domains */ | |
7667 | for_each_cpu(i, cpu_map) { | |
7668 | for (sd = *per_cpu_ptr(d.sd, i); sd; sd = sd->parent) { | |
7669 | sd->span_weight = cpumask_weight(sched_domain_span(sd)); | |
e3589f6c PZ |
7670 | if (sd->flags & SD_OVERLAP) { |
7671 | if (build_overlap_sched_groups(sd, i)) | |
7672 | goto error; | |
7673 | } else { | |
7674 | if (build_sched_groups(sd, i)) | |
7675 | goto error; | |
7676 | } | |
1cf51902 | 7677 | } |
a06dadbe | 7678 | } |
9c1cfda2 | 7679 | |
1da177e4 | 7680 | /* Calculate CPU power for physical packages and nodes */ |
a9c9a9b6 PZ |
7681 | for (i = nr_cpumask_bits-1; i >= 0; i--) { |
7682 | if (!cpumask_test_cpu(i, cpu_map)) | |
7683 | continue; | |
9c1cfda2 | 7684 | |
dce840a0 PZ |
7685 | for (sd = *per_cpu_ptr(d.sd, i); sd; sd = sd->parent) { |
7686 | claim_allocations(i, sd); | |
cd4ea6ae | 7687 | init_sched_groups_power(i, sd); |
dce840a0 | 7688 | } |
f712c0c7 | 7689 | } |
9c1cfda2 | 7690 | |
1da177e4 | 7691 | /* Attach the domains */ |
dce840a0 | 7692 | rcu_read_lock(); |
abcd083a | 7693 | for_each_cpu(i, cpu_map) { |
21d42ccf | 7694 | sd = *per_cpu_ptr(d.sd, i); |
49a02c51 | 7695 | cpu_attach_domain(sd, d.rd, i); |
1da177e4 | 7696 | } |
dce840a0 | 7697 | rcu_read_unlock(); |
51888ca2 | 7698 | |
822ff793 | 7699 | ret = 0; |
51888ca2 | 7700 | error: |
2109b99e | 7701 | __free_domain_allocs(&d, alloc_state, cpu_map); |
822ff793 | 7702 | return ret; |
1da177e4 | 7703 | } |
029190c5 | 7704 | |
acc3f5d7 | 7705 | static cpumask_var_t *doms_cur; /* current sched domains */ |
029190c5 | 7706 | static int ndoms_cur; /* number of sched domains in 'doms_cur' */ |
4285f594 IM |
7707 | static struct sched_domain_attr *dattr_cur; |
7708 | /* attribues of custom domains in 'doms_cur' */ | |
029190c5 PJ |
7709 | |
7710 | /* | |
7711 | * Special case: If a kmalloc of a doms_cur partition (array of | |
4212823f RR |
7712 | * cpumask) fails, then fallback to a single sched domain, |
7713 | * as determined by the single cpumask fallback_doms. | |
029190c5 | 7714 | */ |
4212823f | 7715 | static cpumask_var_t fallback_doms; |
029190c5 | 7716 | |
ee79d1bd HC |
7717 | /* |
7718 | * arch_update_cpu_topology lets virtualized architectures update the | |
7719 | * cpu core maps. It is supposed to return 1 if the topology changed | |
7720 | * or 0 if it stayed the same. | |
7721 | */ | |
7722 | int __attribute__((weak)) arch_update_cpu_topology(void) | |
22e52b07 | 7723 | { |
ee79d1bd | 7724 | return 0; |
22e52b07 HC |
7725 | } |
7726 | ||
acc3f5d7 RR |
7727 | cpumask_var_t *alloc_sched_domains(unsigned int ndoms) |
7728 | { | |
7729 | int i; | |
7730 | cpumask_var_t *doms; | |
7731 | ||
7732 | doms = kmalloc(sizeof(*doms) * ndoms, GFP_KERNEL); | |
7733 | if (!doms) | |
7734 | return NULL; | |
7735 | for (i = 0; i < ndoms; i++) { | |
7736 | if (!alloc_cpumask_var(&doms[i], GFP_KERNEL)) { | |
7737 | free_sched_domains(doms, i); | |
7738 | return NULL; | |
7739 | } | |
7740 | } | |
7741 | return doms; | |
7742 | } | |
7743 | ||
7744 | void free_sched_domains(cpumask_var_t doms[], unsigned int ndoms) | |
7745 | { | |
7746 | unsigned int i; | |
7747 | for (i = 0; i < ndoms; i++) | |
7748 | free_cpumask_var(doms[i]); | |
7749 | kfree(doms); | |
7750 | } | |
7751 | ||
1a20ff27 | 7752 | /* |
41a2d6cf | 7753 | * Set up scheduler domains and groups. Callers must hold the hotplug lock. |
029190c5 PJ |
7754 | * For now this just excludes isolated cpus, but could be used to |
7755 | * exclude other special cases in the future. | |
1a20ff27 | 7756 | */ |
c4a8849a | 7757 | static int init_sched_domains(const struct cpumask *cpu_map) |
1a20ff27 | 7758 | { |
7378547f MM |
7759 | int err; |
7760 | ||
22e52b07 | 7761 | arch_update_cpu_topology(); |
029190c5 | 7762 | ndoms_cur = 1; |
acc3f5d7 | 7763 | doms_cur = alloc_sched_domains(ndoms_cur); |
029190c5 | 7764 | if (!doms_cur) |
acc3f5d7 RR |
7765 | doms_cur = &fallback_doms; |
7766 | cpumask_andnot(doms_cur[0], cpu_map, cpu_isolated_map); | |
1d3504fc | 7767 | dattr_cur = NULL; |
dce840a0 | 7768 | err = build_sched_domains(doms_cur[0], NULL); |
6382bc90 | 7769 | register_sched_domain_sysctl(); |
7378547f MM |
7770 | |
7771 | return err; | |
1a20ff27 DG |
7772 | } |
7773 | ||
1a20ff27 DG |
7774 | /* |
7775 | * Detach sched domains from a group of cpus specified in cpu_map | |
7776 | * These cpus will now be attached to the NULL domain | |
7777 | */ | |
96f874e2 | 7778 | static void detach_destroy_domains(const struct cpumask *cpu_map) |
1a20ff27 DG |
7779 | { |
7780 | int i; | |
7781 | ||
dce840a0 | 7782 | rcu_read_lock(); |
abcd083a | 7783 | for_each_cpu(i, cpu_map) |
57d885fe | 7784 | cpu_attach_domain(NULL, &def_root_domain, i); |
dce840a0 | 7785 | rcu_read_unlock(); |
1a20ff27 DG |
7786 | } |
7787 | ||
1d3504fc HS |
7788 | /* handle null as "default" */ |
7789 | static int dattrs_equal(struct sched_domain_attr *cur, int idx_cur, | |
7790 | struct sched_domain_attr *new, int idx_new) | |
7791 | { | |
7792 | struct sched_domain_attr tmp; | |
7793 | ||
7794 | /* fast path */ | |
7795 | if (!new && !cur) | |
7796 | return 1; | |
7797 | ||
7798 | tmp = SD_ATTR_INIT; | |
7799 | return !memcmp(cur ? (cur + idx_cur) : &tmp, | |
7800 | new ? (new + idx_new) : &tmp, | |
7801 | sizeof(struct sched_domain_attr)); | |
7802 | } | |
7803 | ||
029190c5 PJ |
7804 | /* |
7805 | * Partition sched domains as specified by the 'ndoms_new' | |
41a2d6cf | 7806 | * cpumasks in the array doms_new[] of cpumasks. This compares |
029190c5 PJ |
7807 | * doms_new[] to the current sched domain partitioning, doms_cur[]. |
7808 | * It destroys each deleted domain and builds each new domain. | |
7809 | * | |
acc3f5d7 | 7810 | * 'doms_new' is an array of cpumask_var_t's of length 'ndoms_new'. |
41a2d6cf IM |
7811 | * The masks don't intersect (don't overlap.) We should setup one |
7812 | * sched domain for each mask. CPUs not in any of the cpumasks will | |
7813 | * not be load balanced. If the same cpumask appears both in the | |
029190c5 PJ |
7814 | * current 'doms_cur' domains and in the new 'doms_new', we can leave |
7815 | * it as it is. | |
7816 | * | |
acc3f5d7 RR |
7817 | * The passed in 'doms_new' should be allocated using |
7818 | * alloc_sched_domains. This routine takes ownership of it and will | |
7819 | * free_sched_domains it when done with it. If the caller failed the | |
7820 | * alloc call, then it can pass in doms_new == NULL && ndoms_new == 1, | |
7821 | * and partition_sched_domains() will fallback to the single partition | |
7822 | * 'fallback_doms', it also forces the domains to be rebuilt. | |
029190c5 | 7823 | * |
96f874e2 | 7824 | * If doms_new == NULL it will be replaced with cpu_online_mask. |
700018e0 LZ |
7825 | * ndoms_new == 0 is a special case for destroying existing domains, |
7826 | * and it will not create the default domain. | |
dfb512ec | 7827 | * |
029190c5 PJ |
7828 | * Call with hotplug lock held |
7829 | */ | |
acc3f5d7 | 7830 | void partition_sched_domains(int ndoms_new, cpumask_var_t doms_new[], |
1d3504fc | 7831 | struct sched_domain_attr *dattr_new) |
029190c5 | 7832 | { |
dfb512ec | 7833 | int i, j, n; |
d65bd5ec | 7834 | int new_topology; |
029190c5 | 7835 | |
712555ee | 7836 | mutex_lock(&sched_domains_mutex); |
a1835615 | 7837 | |
7378547f MM |
7838 | /* always unregister in case we don't destroy any domains */ |
7839 | unregister_sched_domain_sysctl(); | |
7840 | ||
d65bd5ec HC |
7841 | /* Let architecture update cpu core mappings. */ |
7842 | new_topology = arch_update_cpu_topology(); | |
7843 | ||
dfb512ec | 7844 | n = doms_new ? ndoms_new : 0; |
029190c5 PJ |
7845 | |
7846 | /* Destroy deleted domains */ | |
7847 | for (i = 0; i < ndoms_cur; i++) { | |
d65bd5ec | 7848 | for (j = 0; j < n && !new_topology; j++) { |
acc3f5d7 | 7849 | if (cpumask_equal(doms_cur[i], doms_new[j]) |
1d3504fc | 7850 | && dattrs_equal(dattr_cur, i, dattr_new, j)) |
029190c5 PJ |
7851 | goto match1; |
7852 | } | |
7853 | /* no match - a current sched domain not in new doms_new[] */ | |
acc3f5d7 | 7854 | detach_destroy_domains(doms_cur[i]); |
029190c5 PJ |
7855 | match1: |
7856 | ; | |
7857 | } | |
7858 | ||
e761b772 MK |
7859 | if (doms_new == NULL) { |
7860 | ndoms_cur = 0; | |
acc3f5d7 | 7861 | doms_new = &fallback_doms; |
6ad4c188 | 7862 | cpumask_andnot(doms_new[0], cpu_active_mask, cpu_isolated_map); |
faa2f98f | 7863 | WARN_ON_ONCE(dattr_new); |
e761b772 MK |
7864 | } |
7865 | ||
029190c5 PJ |
7866 | /* Build new domains */ |
7867 | for (i = 0; i < ndoms_new; i++) { | |
d65bd5ec | 7868 | for (j = 0; j < ndoms_cur && !new_topology; j++) { |
acc3f5d7 | 7869 | if (cpumask_equal(doms_new[i], doms_cur[j]) |
1d3504fc | 7870 | && dattrs_equal(dattr_new, i, dattr_cur, j)) |
029190c5 PJ |
7871 | goto match2; |
7872 | } | |
7873 | /* no match - add a new doms_new */ | |
dce840a0 | 7874 | build_sched_domains(doms_new[i], dattr_new ? dattr_new + i : NULL); |
029190c5 PJ |
7875 | match2: |
7876 | ; | |
7877 | } | |
7878 | ||
7879 | /* Remember the new sched domains */ | |
acc3f5d7 RR |
7880 | if (doms_cur != &fallback_doms) |
7881 | free_sched_domains(doms_cur, ndoms_cur); | |
1d3504fc | 7882 | kfree(dattr_cur); /* kfree(NULL) is safe */ |
029190c5 | 7883 | doms_cur = doms_new; |
1d3504fc | 7884 | dattr_cur = dattr_new; |
029190c5 | 7885 | ndoms_cur = ndoms_new; |
7378547f MM |
7886 | |
7887 | register_sched_domain_sysctl(); | |
a1835615 | 7888 | |
712555ee | 7889 | mutex_unlock(&sched_domains_mutex); |
029190c5 PJ |
7890 | } |
7891 | ||
5c45bf27 | 7892 | #if defined(CONFIG_SCHED_MC) || defined(CONFIG_SCHED_SMT) |
c4a8849a | 7893 | static void reinit_sched_domains(void) |
5c45bf27 | 7894 | { |
95402b38 | 7895 | get_online_cpus(); |
dfb512ec MK |
7896 | |
7897 | /* Destroy domains first to force the rebuild */ | |
7898 | partition_sched_domains(0, NULL, NULL); | |
7899 | ||
e761b772 | 7900 | rebuild_sched_domains(); |
95402b38 | 7901 | put_online_cpus(); |
5c45bf27 SS |
7902 | } |
7903 | ||
7904 | static ssize_t sched_power_savings_store(const char *buf, size_t count, int smt) | |
7905 | { | |
afb8a9b7 | 7906 | unsigned int level = 0; |
5c45bf27 | 7907 | |
afb8a9b7 GS |
7908 | if (sscanf(buf, "%u", &level) != 1) |
7909 | return -EINVAL; | |
7910 | ||
7911 | /* | |
7912 | * level is always be positive so don't check for | |
7913 | * level < POWERSAVINGS_BALANCE_NONE which is 0 | |
7914 | * What happens on 0 or 1 byte write, | |
7915 | * need to check for count as well? | |
7916 | */ | |
7917 | ||
7918 | if (level >= MAX_POWERSAVINGS_BALANCE_LEVELS) | |
5c45bf27 SS |
7919 | return -EINVAL; |
7920 | ||
7921 | if (smt) | |
afb8a9b7 | 7922 | sched_smt_power_savings = level; |
5c45bf27 | 7923 | else |
afb8a9b7 | 7924 | sched_mc_power_savings = level; |
5c45bf27 | 7925 | |
c4a8849a | 7926 | reinit_sched_domains(); |
5c45bf27 | 7927 | |
c70f22d2 | 7928 | return count; |
5c45bf27 SS |
7929 | } |
7930 | ||
5c45bf27 | 7931 | #ifdef CONFIG_SCHED_MC |
f718cd4a | 7932 | static ssize_t sched_mc_power_savings_show(struct sysdev_class *class, |
c9be0a36 | 7933 | struct sysdev_class_attribute *attr, |
f718cd4a | 7934 | char *page) |
5c45bf27 SS |
7935 | { |
7936 | return sprintf(page, "%u\n", sched_mc_power_savings); | |
7937 | } | |
f718cd4a | 7938 | static ssize_t sched_mc_power_savings_store(struct sysdev_class *class, |
c9be0a36 | 7939 | struct sysdev_class_attribute *attr, |
48f24c4d | 7940 | const char *buf, size_t count) |
5c45bf27 SS |
7941 | { |
7942 | return sched_power_savings_store(buf, count, 0); | |
7943 | } | |
f718cd4a AK |
7944 | static SYSDEV_CLASS_ATTR(sched_mc_power_savings, 0644, |
7945 | sched_mc_power_savings_show, | |
7946 | sched_mc_power_savings_store); | |
5c45bf27 SS |
7947 | #endif |
7948 | ||
7949 | #ifdef CONFIG_SCHED_SMT | |
f718cd4a | 7950 | static ssize_t sched_smt_power_savings_show(struct sysdev_class *dev, |
c9be0a36 | 7951 | struct sysdev_class_attribute *attr, |
f718cd4a | 7952 | char *page) |
5c45bf27 SS |
7953 | { |
7954 | return sprintf(page, "%u\n", sched_smt_power_savings); | |
7955 | } | |
f718cd4a | 7956 | static ssize_t sched_smt_power_savings_store(struct sysdev_class *dev, |
c9be0a36 | 7957 | struct sysdev_class_attribute *attr, |
48f24c4d | 7958 | const char *buf, size_t count) |
5c45bf27 SS |
7959 | { |
7960 | return sched_power_savings_store(buf, count, 1); | |
7961 | } | |
f718cd4a AK |
7962 | static SYSDEV_CLASS_ATTR(sched_smt_power_savings, 0644, |
7963 | sched_smt_power_savings_show, | |
6707de00 AB |
7964 | sched_smt_power_savings_store); |
7965 | #endif | |
7966 | ||
39aac648 | 7967 | int __init sched_create_sysfs_power_savings_entries(struct sysdev_class *cls) |
6707de00 AB |
7968 | { |
7969 | int err = 0; | |
7970 | ||
7971 | #ifdef CONFIG_SCHED_SMT | |
7972 | if (smt_capable()) | |
7973 | err = sysfs_create_file(&cls->kset.kobj, | |
7974 | &attr_sched_smt_power_savings.attr); | |
7975 | #endif | |
7976 | #ifdef CONFIG_SCHED_MC | |
7977 | if (!err && mc_capable()) | |
7978 | err = sysfs_create_file(&cls->kset.kobj, | |
7979 | &attr_sched_mc_power_savings.attr); | |
7980 | #endif | |
7981 | return err; | |
7982 | } | |
6d6bc0ad | 7983 | #endif /* CONFIG_SCHED_MC || CONFIG_SCHED_SMT */ |
5c45bf27 | 7984 | |
1da177e4 | 7985 | /* |
3a101d05 TH |
7986 | * Update cpusets according to cpu_active mask. If cpusets are |
7987 | * disabled, cpuset_update_active_cpus() becomes a simple wrapper | |
7988 | * around partition_sched_domains(). | |
1da177e4 | 7989 | */ |
0b2e918a TH |
7990 | static int cpuset_cpu_active(struct notifier_block *nfb, unsigned long action, |
7991 | void *hcpu) | |
e761b772 | 7992 | { |
3a101d05 | 7993 | switch (action & ~CPU_TASKS_FROZEN) { |
e761b772 | 7994 | case CPU_ONLINE: |
6ad4c188 | 7995 | case CPU_DOWN_FAILED: |
3a101d05 | 7996 | cpuset_update_active_cpus(); |
e761b772 | 7997 | return NOTIFY_OK; |
3a101d05 TH |
7998 | default: |
7999 | return NOTIFY_DONE; | |
8000 | } | |
8001 | } | |
e761b772 | 8002 | |
0b2e918a TH |
8003 | static int cpuset_cpu_inactive(struct notifier_block *nfb, unsigned long action, |
8004 | void *hcpu) | |
3a101d05 TH |
8005 | { |
8006 | switch (action & ~CPU_TASKS_FROZEN) { | |
8007 | case CPU_DOWN_PREPARE: | |
8008 | cpuset_update_active_cpus(); | |
8009 | return NOTIFY_OK; | |
e761b772 MK |
8010 | default: |
8011 | return NOTIFY_DONE; | |
8012 | } | |
8013 | } | |
e761b772 MK |
8014 | |
8015 | static int update_runtime(struct notifier_block *nfb, | |
8016 | unsigned long action, void *hcpu) | |
1da177e4 | 8017 | { |
7def2be1 PZ |
8018 | int cpu = (int)(long)hcpu; |
8019 | ||
1da177e4 | 8020 | switch (action) { |
1da177e4 | 8021 | case CPU_DOWN_PREPARE: |
8bb78442 | 8022 | case CPU_DOWN_PREPARE_FROZEN: |
7def2be1 | 8023 | disable_runtime(cpu_rq(cpu)); |
1da177e4 LT |
8024 | return NOTIFY_OK; |
8025 | ||
1da177e4 | 8026 | case CPU_DOWN_FAILED: |
8bb78442 | 8027 | case CPU_DOWN_FAILED_FROZEN: |
1da177e4 | 8028 | case CPU_ONLINE: |
8bb78442 | 8029 | case CPU_ONLINE_FROZEN: |
7def2be1 | 8030 | enable_runtime(cpu_rq(cpu)); |
e761b772 MK |
8031 | return NOTIFY_OK; |
8032 | ||
1da177e4 LT |
8033 | default: |
8034 | return NOTIFY_DONE; | |
8035 | } | |
1da177e4 | 8036 | } |
1da177e4 LT |
8037 | |
8038 | void __init sched_init_smp(void) | |
8039 | { | |
dcc30a35 RR |
8040 | cpumask_var_t non_isolated_cpus; |
8041 | ||
8042 | alloc_cpumask_var(&non_isolated_cpus, GFP_KERNEL); | |
cb5fd13f | 8043 | alloc_cpumask_var(&fallback_doms, GFP_KERNEL); |
5c1e1767 | 8044 | |
95402b38 | 8045 | get_online_cpus(); |
712555ee | 8046 | mutex_lock(&sched_domains_mutex); |
c4a8849a | 8047 | init_sched_domains(cpu_active_mask); |
dcc30a35 RR |
8048 | cpumask_andnot(non_isolated_cpus, cpu_possible_mask, cpu_isolated_map); |
8049 | if (cpumask_empty(non_isolated_cpus)) | |
8050 | cpumask_set_cpu(smp_processor_id(), non_isolated_cpus); | |
712555ee | 8051 | mutex_unlock(&sched_domains_mutex); |
95402b38 | 8052 | put_online_cpus(); |
e761b772 | 8053 | |
3a101d05 TH |
8054 | hotcpu_notifier(cpuset_cpu_active, CPU_PRI_CPUSET_ACTIVE); |
8055 | hotcpu_notifier(cpuset_cpu_inactive, CPU_PRI_CPUSET_INACTIVE); | |
e761b772 MK |
8056 | |
8057 | /* RT runtime code needs to handle some hotplug events */ | |
8058 | hotcpu_notifier(update_runtime, 0); | |
8059 | ||
b328ca18 | 8060 | init_hrtick(); |
5c1e1767 NP |
8061 | |
8062 | /* Move init over to a non-isolated CPU */ | |
dcc30a35 | 8063 | if (set_cpus_allowed_ptr(current, non_isolated_cpus) < 0) |
5c1e1767 | 8064 | BUG(); |
19978ca6 | 8065 | sched_init_granularity(); |
dcc30a35 | 8066 | free_cpumask_var(non_isolated_cpus); |
4212823f | 8067 | |
0e3900e6 | 8068 | init_sched_rt_class(); |
1da177e4 LT |
8069 | } |
8070 | #else | |
8071 | void __init sched_init_smp(void) | |
8072 | { | |
19978ca6 | 8073 | sched_init_granularity(); |
1da177e4 LT |
8074 | } |
8075 | #endif /* CONFIG_SMP */ | |
8076 | ||
cd1bb94b AB |
8077 | const_debug unsigned int sysctl_timer_migration = 1; |
8078 | ||
1da177e4 LT |
8079 | int in_sched_functions(unsigned long addr) |
8080 | { | |
1da177e4 LT |
8081 | return in_lock_functions(addr) || |
8082 | (addr >= (unsigned long)__sched_text_start | |
8083 | && addr < (unsigned long)__sched_text_end); | |
8084 | } | |
8085 | ||
acb5a9ba | 8086 | static void init_cfs_rq(struct cfs_rq *cfs_rq) |
dd41f596 IM |
8087 | { |
8088 | cfs_rq->tasks_timeline = RB_ROOT; | |
4a55bd5e | 8089 | INIT_LIST_HEAD(&cfs_rq->tasks); |
67e9fb2a | 8090 | cfs_rq->min_vruntime = (u64)(-(1LL << 20)); |
c64be78f PZ |
8091 | #ifndef CONFIG_64BIT |
8092 | cfs_rq->min_vruntime_copy = cfs_rq->min_vruntime; | |
8093 | #endif | |
dd41f596 IM |
8094 | } |
8095 | ||
fa85ae24 PZ |
8096 | static void init_rt_rq(struct rt_rq *rt_rq, struct rq *rq) |
8097 | { | |
8098 | struct rt_prio_array *array; | |
8099 | int i; | |
8100 | ||
8101 | array = &rt_rq->active; | |
8102 | for (i = 0; i < MAX_RT_PRIO; i++) { | |
8103 | INIT_LIST_HEAD(array->queue + i); | |
8104 | __clear_bit(i, array->bitmap); | |
8105 | } | |
8106 | /* delimiter for bitsearch: */ | |
8107 | __set_bit(MAX_RT_PRIO, array->bitmap); | |
8108 | ||
acb5a9ba | 8109 | #if defined CONFIG_SMP |
e864c499 GH |
8110 | rt_rq->highest_prio.curr = MAX_RT_PRIO; |
8111 | rt_rq->highest_prio.next = MAX_RT_PRIO; | |
fa85ae24 | 8112 | rt_rq->rt_nr_migratory = 0; |
fa85ae24 | 8113 | rt_rq->overloaded = 0; |
732375c6 | 8114 | plist_head_init(&rt_rq->pushable_tasks); |
fa85ae24 PZ |
8115 | #endif |
8116 | ||
8117 | rt_rq->rt_time = 0; | |
8118 | rt_rq->rt_throttled = 0; | |
ac086bc2 | 8119 | rt_rq->rt_runtime = 0; |
0986b11b | 8120 | raw_spin_lock_init(&rt_rq->rt_runtime_lock); |
fa85ae24 PZ |
8121 | } |
8122 | ||
6f505b16 | 8123 | #ifdef CONFIG_FAIR_GROUP_SCHED |
ec7dc8ac | 8124 | static void init_tg_cfs_entry(struct task_group *tg, struct cfs_rq *cfs_rq, |
3d4b47b4 | 8125 | struct sched_entity *se, int cpu, |
ec7dc8ac | 8126 | struct sched_entity *parent) |
6f505b16 | 8127 | { |
ec7dc8ac | 8128 | struct rq *rq = cpu_rq(cpu); |
acb5a9ba | 8129 | |
6f505b16 | 8130 | cfs_rq->tg = tg; |
acb5a9ba JS |
8131 | cfs_rq->rq = rq; |
8132 | #ifdef CONFIG_SMP | |
8133 | /* allow initial update_cfs_load() to truncate */ | |
8134 | cfs_rq->load_stamp = 1; | |
8135 | #endif | |
ab84d31e | 8136 | init_cfs_rq_runtime(cfs_rq); |
6f505b16 | 8137 | |
acb5a9ba | 8138 | tg->cfs_rq[cpu] = cfs_rq; |
6f505b16 | 8139 | tg->se[cpu] = se; |
acb5a9ba | 8140 | |
07e06b01 | 8141 | /* se could be NULL for root_task_group */ |
354d60c2 DG |
8142 | if (!se) |
8143 | return; | |
8144 | ||
ec7dc8ac DG |
8145 | if (!parent) |
8146 | se->cfs_rq = &rq->cfs; | |
8147 | else | |
8148 | se->cfs_rq = parent->my_q; | |
8149 | ||
6f505b16 | 8150 | se->my_q = cfs_rq; |
9437178f | 8151 | update_load_set(&se->load, 0); |
ec7dc8ac | 8152 | se->parent = parent; |
6f505b16 | 8153 | } |
052f1dc7 | 8154 | #endif |
6f505b16 | 8155 | |
052f1dc7 | 8156 | #ifdef CONFIG_RT_GROUP_SCHED |
ec7dc8ac | 8157 | static void init_tg_rt_entry(struct task_group *tg, struct rt_rq *rt_rq, |
3d4b47b4 | 8158 | struct sched_rt_entity *rt_se, int cpu, |
ec7dc8ac | 8159 | struct sched_rt_entity *parent) |
6f505b16 | 8160 | { |
ec7dc8ac DG |
8161 | struct rq *rq = cpu_rq(cpu); |
8162 | ||
acb5a9ba JS |
8163 | rt_rq->highest_prio.curr = MAX_RT_PRIO; |
8164 | rt_rq->rt_nr_boosted = 0; | |
8165 | rt_rq->rq = rq; | |
6f505b16 | 8166 | rt_rq->tg = tg; |
6f505b16 | 8167 | |
acb5a9ba | 8168 | tg->rt_rq[cpu] = rt_rq; |
6f505b16 | 8169 | tg->rt_se[cpu] = rt_se; |
acb5a9ba | 8170 | |
354d60c2 DG |
8171 | if (!rt_se) |
8172 | return; | |
8173 | ||
ec7dc8ac DG |
8174 | if (!parent) |
8175 | rt_se->rt_rq = &rq->rt; | |
8176 | else | |
8177 | rt_se->rt_rq = parent->my_q; | |
8178 | ||
6f505b16 | 8179 | rt_se->my_q = rt_rq; |
ec7dc8ac | 8180 | rt_se->parent = parent; |
6f505b16 PZ |
8181 | INIT_LIST_HEAD(&rt_se->run_list); |
8182 | } | |
8183 | #endif | |
8184 | ||
1da177e4 LT |
8185 | void __init sched_init(void) |
8186 | { | |
dd41f596 | 8187 | int i, j; |
434d53b0 MT |
8188 | unsigned long alloc_size = 0, ptr; |
8189 | ||
8190 | #ifdef CONFIG_FAIR_GROUP_SCHED | |
8191 | alloc_size += 2 * nr_cpu_ids * sizeof(void **); | |
8192 | #endif | |
8193 | #ifdef CONFIG_RT_GROUP_SCHED | |
8194 | alloc_size += 2 * nr_cpu_ids * sizeof(void **); | |
eff766a6 | 8195 | #endif |
df7c8e84 | 8196 | #ifdef CONFIG_CPUMASK_OFFSTACK |
8c083f08 | 8197 | alloc_size += num_possible_cpus() * cpumask_size(); |
434d53b0 | 8198 | #endif |
434d53b0 | 8199 | if (alloc_size) { |
36b7b6d4 | 8200 | ptr = (unsigned long)kzalloc(alloc_size, GFP_NOWAIT); |
434d53b0 MT |
8201 | |
8202 | #ifdef CONFIG_FAIR_GROUP_SCHED | |
07e06b01 | 8203 | root_task_group.se = (struct sched_entity **)ptr; |
434d53b0 MT |
8204 | ptr += nr_cpu_ids * sizeof(void **); |
8205 | ||
07e06b01 | 8206 | root_task_group.cfs_rq = (struct cfs_rq **)ptr; |
434d53b0 | 8207 | ptr += nr_cpu_ids * sizeof(void **); |
eff766a6 | 8208 | |
6d6bc0ad | 8209 | #endif /* CONFIG_FAIR_GROUP_SCHED */ |
434d53b0 | 8210 | #ifdef CONFIG_RT_GROUP_SCHED |
07e06b01 | 8211 | root_task_group.rt_se = (struct sched_rt_entity **)ptr; |
434d53b0 MT |
8212 | ptr += nr_cpu_ids * sizeof(void **); |
8213 | ||
07e06b01 | 8214 | root_task_group.rt_rq = (struct rt_rq **)ptr; |
eff766a6 PZ |
8215 | ptr += nr_cpu_ids * sizeof(void **); |
8216 | ||
6d6bc0ad | 8217 | #endif /* CONFIG_RT_GROUP_SCHED */ |
df7c8e84 RR |
8218 | #ifdef CONFIG_CPUMASK_OFFSTACK |
8219 | for_each_possible_cpu(i) { | |
8220 | per_cpu(load_balance_tmpmask, i) = (void *)ptr; | |
8221 | ptr += cpumask_size(); | |
8222 | } | |
8223 | #endif /* CONFIG_CPUMASK_OFFSTACK */ | |
434d53b0 | 8224 | } |
dd41f596 | 8225 | |
57d885fe GH |
8226 | #ifdef CONFIG_SMP |
8227 | init_defrootdomain(); | |
8228 | #endif | |
8229 | ||
d0b27fa7 PZ |
8230 | init_rt_bandwidth(&def_rt_bandwidth, |
8231 | global_rt_period(), global_rt_runtime()); | |
8232 | ||
8233 | #ifdef CONFIG_RT_GROUP_SCHED | |
07e06b01 | 8234 | init_rt_bandwidth(&root_task_group.rt_bandwidth, |
d0b27fa7 | 8235 | global_rt_period(), global_rt_runtime()); |
6d6bc0ad | 8236 | #endif /* CONFIG_RT_GROUP_SCHED */ |
d0b27fa7 | 8237 | |
7c941438 | 8238 | #ifdef CONFIG_CGROUP_SCHED |
07e06b01 YZ |
8239 | list_add(&root_task_group.list, &task_groups); |
8240 | INIT_LIST_HEAD(&root_task_group.children); | |
5091faa4 | 8241 | autogroup_init(&init_task); |
7c941438 | 8242 | #endif /* CONFIG_CGROUP_SCHED */ |
6f505b16 | 8243 | |
0a945022 | 8244 | for_each_possible_cpu(i) { |
70b97a7f | 8245 | struct rq *rq; |
1da177e4 LT |
8246 | |
8247 | rq = cpu_rq(i); | |
05fa785c | 8248 | raw_spin_lock_init(&rq->lock); |
7897986b | 8249 | rq->nr_running = 0; |
dce48a84 TG |
8250 | rq->calc_load_active = 0; |
8251 | rq->calc_load_update = jiffies + LOAD_FREQ; | |
acb5a9ba | 8252 | init_cfs_rq(&rq->cfs); |
6f505b16 | 8253 | init_rt_rq(&rq->rt, rq); |
dd41f596 | 8254 | #ifdef CONFIG_FAIR_GROUP_SCHED |
07e06b01 | 8255 | root_task_group.shares = root_task_group_load; |
6f505b16 | 8256 | INIT_LIST_HEAD(&rq->leaf_cfs_rq_list); |
354d60c2 | 8257 | /* |
07e06b01 | 8258 | * How much cpu bandwidth does root_task_group get? |
354d60c2 DG |
8259 | * |
8260 | * In case of task-groups formed thr' the cgroup filesystem, it | |
8261 | * gets 100% of the cpu resources in the system. This overall | |
8262 | * system cpu resource is divided among the tasks of | |
07e06b01 | 8263 | * root_task_group and its child task-groups in a fair manner, |
354d60c2 DG |
8264 | * based on each entity's (task or task-group's) weight |
8265 | * (se->load.weight). | |
8266 | * | |
07e06b01 | 8267 | * In other words, if root_task_group has 10 tasks of weight |
354d60c2 DG |
8268 | * 1024) and two child groups A0 and A1 (of weight 1024 each), |
8269 | * then A0's share of the cpu resource is: | |
8270 | * | |
0d905bca | 8271 | * A0's bandwidth = 1024 / (10*1024 + 1024 + 1024) = 8.33% |
354d60c2 | 8272 | * |
07e06b01 YZ |
8273 | * We achieve this by letting root_task_group's tasks sit |
8274 | * directly in rq->cfs (i.e root_task_group->se[] = NULL). | |
354d60c2 | 8275 | */ |
ab84d31e | 8276 | init_cfs_bandwidth(&root_task_group.cfs_bandwidth); |
07e06b01 | 8277 | init_tg_cfs_entry(&root_task_group, &rq->cfs, NULL, i, NULL); |
354d60c2 DG |
8278 | #endif /* CONFIG_FAIR_GROUP_SCHED */ |
8279 | ||
8280 | rq->rt.rt_runtime = def_rt_bandwidth.rt_runtime; | |
052f1dc7 | 8281 | #ifdef CONFIG_RT_GROUP_SCHED |
6f505b16 | 8282 | INIT_LIST_HEAD(&rq->leaf_rt_rq_list); |
07e06b01 | 8283 | init_tg_rt_entry(&root_task_group, &rq->rt, NULL, i, NULL); |
dd41f596 | 8284 | #endif |
1da177e4 | 8285 | |
dd41f596 IM |
8286 | for (j = 0; j < CPU_LOAD_IDX_MAX; j++) |
8287 | rq->cpu_load[j] = 0; | |
fdf3e95d VP |
8288 | |
8289 | rq->last_load_update_tick = jiffies; | |
8290 | ||
1da177e4 | 8291 | #ifdef CONFIG_SMP |
41c7ce9a | 8292 | rq->sd = NULL; |
57d885fe | 8293 | rq->rd = NULL; |
1399fa78 | 8294 | rq->cpu_power = SCHED_POWER_SCALE; |
3f029d3c | 8295 | rq->post_schedule = 0; |
1da177e4 | 8296 | rq->active_balance = 0; |
dd41f596 | 8297 | rq->next_balance = jiffies; |
1da177e4 | 8298 | rq->push_cpu = 0; |
0a2966b4 | 8299 | rq->cpu = i; |
1f11eb6a | 8300 | rq->online = 0; |
eae0c9df MG |
8301 | rq->idle_stamp = 0; |
8302 | rq->avg_idle = 2*sysctl_sched_migration_cost; | |
dc938520 | 8303 | rq_attach_root(rq, &def_root_domain); |
83cd4fe2 VP |
8304 | #ifdef CONFIG_NO_HZ |
8305 | rq->nohz_balance_kick = 0; | |
83cd4fe2 | 8306 | #endif |
1da177e4 | 8307 | #endif |
8f4d37ec | 8308 | init_rq_hrtick(rq); |
1da177e4 | 8309 | atomic_set(&rq->nr_iowait, 0); |
1da177e4 LT |
8310 | } |
8311 | ||
2dd73a4f | 8312 | set_load_weight(&init_task); |
b50f60ce | 8313 | |
e107be36 AK |
8314 | #ifdef CONFIG_PREEMPT_NOTIFIERS |
8315 | INIT_HLIST_HEAD(&init_task.preempt_notifiers); | |
8316 | #endif | |
8317 | ||
c9819f45 | 8318 | #ifdef CONFIG_SMP |
962cf36c | 8319 | open_softirq(SCHED_SOFTIRQ, run_rebalance_domains); |
c9819f45 CL |
8320 | #endif |
8321 | ||
b50f60ce | 8322 | #ifdef CONFIG_RT_MUTEXES |
732375c6 | 8323 | plist_head_init(&init_task.pi_waiters); |
b50f60ce HC |
8324 | #endif |
8325 | ||
1da177e4 LT |
8326 | /* |
8327 | * The boot idle thread does lazy MMU switching as well: | |
8328 | */ | |
8329 | atomic_inc(&init_mm.mm_count); | |
8330 | enter_lazy_tlb(&init_mm, current); | |
8331 | ||
8332 | /* | |
8333 | * Make us the idle thread. Technically, schedule() should not be | |
8334 | * called from this thread, however somewhere below it might be, | |
8335 | * but because we are the idle thread, we just pick up running again | |
8336 | * when this runqueue becomes "idle". | |
8337 | */ | |
8338 | init_idle(current, smp_processor_id()); | |
dce48a84 TG |
8339 | |
8340 | calc_load_update = jiffies + LOAD_FREQ; | |
8341 | ||
dd41f596 IM |
8342 | /* |
8343 | * During early bootup we pretend to be a normal task: | |
8344 | */ | |
8345 | current->sched_class = &fair_sched_class; | |
6892b75e | 8346 | |
bf4d83f6 | 8347 | #ifdef CONFIG_SMP |
4cb98839 | 8348 | zalloc_cpumask_var(&sched_domains_tmpmask, GFP_NOWAIT); |
7d1e6a9b | 8349 | #ifdef CONFIG_NO_HZ |
83cd4fe2 VP |
8350 | zalloc_cpumask_var(&nohz.idle_cpus_mask, GFP_NOWAIT); |
8351 | alloc_cpumask_var(&nohz.grp_idle_mask, GFP_NOWAIT); | |
8352 | atomic_set(&nohz.load_balancer, nr_cpu_ids); | |
8353 | atomic_set(&nohz.first_pick_cpu, nr_cpu_ids); | |
8354 | atomic_set(&nohz.second_pick_cpu, nr_cpu_ids); | |
7d1e6a9b | 8355 | #endif |
bdddd296 RR |
8356 | /* May be allocated at isolcpus cmdline parse time */ |
8357 | if (cpu_isolated_map == NULL) | |
8358 | zalloc_cpumask_var(&cpu_isolated_map, GFP_NOWAIT); | |
bf4d83f6 | 8359 | #endif /* SMP */ |
6a7b3dc3 | 8360 | |
6892b75e | 8361 | scheduler_running = 1; |
1da177e4 LT |
8362 | } |
8363 | ||
d902db1e | 8364 | #ifdef CONFIG_DEBUG_ATOMIC_SLEEP |
e4aafea2 FW |
8365 | static inline int preempt_count_equals(int preempt_offset) |
8366 | { | |
234da7bc | 8367 | int nested = (preempt_count() & ~PREEMPT_ACTIVE) + rcu_preempt_depth(); |
e4aafea2 | 8368 | |
4ba8216c | 8369 | return (nested == preempt_offset); |
e4aafea2 FW |
8370 | } |
8371 | ||
d894837f | 8372 | void __might_sleep(const char *file, int line, int preempt_offset) |
1da177e4 | 8373 | { |
1da177e4 LT |
8374 | static unsigned long prev_jiffy; /* ratelimiting */ |
8375 | ||
b3fbab05 | 8376 | rcu_sleep_check(); /* WARN_ON_ONCE() by default, no rate limit reqd. */ |
e4aafea2 FW |
8377 | if ((preempt_count_equals(preempt_offset) && !irqs_disabled()) || |
8378 | system_state != SYSTEM_RUNNING || oops_in_progress) | |
aef745fc IM |
8379 | return; |
8380 | if (time_before(jiffies, prev_jiffy + HZ) && prev_jiffy) | |
8381 | return; | |
8382 | prev_jiffy = jiffies; | |
8383 | ||
3df0fc5b PZ |
8384 | printk(KERN_ERR |
8385 | "BUG: sleeping function called from invalid context at %s:%d\n", | |
8386 | file, line); | |
8387 | printk(KERN_ERR | |
8388 | "in_atomic(): %d, irqs_disabled(): %d, pid: %d, name: %s\n", | |
8389 | in_atomic(), irqs_disabled(), | |
8390 | current->pid, current->comm); | |
aef745fc IM |
8391 | |
8392 | debug_show_held_locks(current); | |
8393 | if (irqs_disabled()) | |
8394 | print_irqtrace_events(current); | |
8395 | dump_stack(); | |
1da177e4 LT |
8396 | } |
8397 | EXPORT_SYMBOL(__might_sleep); | |
8398 | #endif | |
8399 | ||
8400 | #ifdef CONFIG_MAGIC_SYSRQ | |
3a5e4dc1 AK |
8401 | static void normalize_task(struct rq *rq, struct task_struct *p) |
8402 | { | |
da7a735e PZ |
8403 | const struct sched_class *prev_class = p->sched_class; |
8404 | int old_prio = p->prio; | |
3a5e4dc1 | 8405 | int on_rq; |
3e51f33f | 8406 | |
fd2f4419 | 8407 | on_rq = p->on_rq; |
3a5e4dc1 AK |
8408 | if (on_rq) |
8409 | deactivate_task(rq, p, 0); | |
8410 | __setscheduler(rq, p, SCHED_NORMAL, 0); | |
8411 | if (on_rq) { | |
8412 | activate_task(rq, p, 0); | |
8413 | resched_task(rq->curr); | |
8414 | } | |
da7a735e PZ |
8415 | |
8416 | check_class_changed(rq, p, prev_class, old_prio); | |
3a5e4dc1 AK |
8417 | } |
8418 | ||
1da177e4 LT |
8419 | void normalize_rt_tasks(void) |
8420 | { | |
a0f98a1c | 8421 | struct task_struct *g, *p; |
1da177e4 | 8422 | unsigned long flags; |
70b97a7f | 8423 | struct rq *rq; |
1da177e4 | 8424 | |
4cf5d77a | 8425 | read_lock_irqsave(&tasklist_lock, flags); |
a0f98a1c | 8426 | do_each_thread(g, p) { |
178be793 IM |
8427 | /* |
8428 | * Only normalize user tasks: | |
8429 | */ | |
8430 | if (!p->mm) | |
8431 | continue; | |
8432 | ||
6cfb0d5d | 8433 | p->se.exec_start = 0; |
6cfb0d5d | 8434 | #ifdef CONFIG_SCHEDSTATS |
41acab88 LDM |
8435 | p->se.statistics.wait_start = 0; |
8436 | p->se.statistics.sleep_start = 0; | |
8437 | p->se.statistics.block_start = 0; | |
6cfb0d5d | 8438 | #endif |
dd41f596 IM |
8439 | |
8440 | if (!rt_task(p)) { | |
8441 | /* | |
8442 | * Renice negative nice level userspace | |
8443 | * tasks back to 0: | |
8444 | */ | |
8445 | if (TASK_NICE(p) < 0 && p->mm) | |
8446 | set_user_nice(p, 0); | |
1da177e4 | 8447 | continue; |
dd41f596 | 8448 | } |
1da177e4 | 8449 | |
1d615482 | 8450 | raw_spin_lock(&p->pi_lock); |
b29739f9 | 8451 | rq = __task_rq_lock(p); |
1da177e4 | 8452 | |
178be793 | 8453 | normalize_task(rq, p); |
3a5e4dc1 | 8454 | |
b29739f9 | 8455 | __task_rq_unlock(rq); |
1d615482 | 8456 | raw_spin_unlock(&p->pi_lock); |
a0f98a1c IM |
8457 | } while_each_thread(g, p); |
8458 | ||
4cf5d77a | 8459 | read_unlock_irqrestore(&tasklist_lock, flags); |
1da177e4 LT |
8460 | } |
8461 | ||
8462 | #endif /* CONFIG_MAGIC_SYSRQ */ | |
1df5c10a | 8463 | |
67fc4e0c | 8464 | #if defined(CONFIG_IA64) || defined(CONFIG_KGDB_KDB) |
1df5c10a | 8465 | /* |
67fc4e0c | 8466 | * These functions are only useful for the IA64 MCA handling, or kdb. |
1df5c10a LT |
8467 | * |
8468 | * They can only be called when the whole system has been | |
8469 | * stopped - every CPU needs to be quiescent, and no scheduling | |
8470 | * activity can take place. Using them for anything else would | |
8471 | * be a serious bug, and as a result, they aren't even visible | |
8472 | * under any other configuration. | |
8473 | */ | |
8474 | ||
8475 | /** | |
8476 | * curr_task - return the current task for a given cpu. | |
8477 | * @cpu: the processor in question. | |
8478 | * | |
8479 | * ONLY VALID WHEN THE WHOLE SYSTEM IS STOPPED! | |
8480 | */ | |
36c8b586 | 8481 | struct task_struct *curr_task(int cpu) |
1df5c10a LT |
8482 | { |
8483 | return cpu_curr(cpu); | |
8484 | } | |
8485 | ||
67fc4e0c JW |
8486 | #endif /* defined(CONFIG_IA64) || defined(CONFIG_KGDB_KDB) */ |
8487 | ||
8488 | #ifdef CONFIG_IA64 | |
1df5c10a LT |
8489 | /** |
8490 | * set_curr_task - set the current task for a given cpu. | |
8491 | * @cpu: the processor in question. | |
8492 | * @p: the task pointer to set. | |
8493 | * | |
8494 | * Description: This function must only be used when non-maskable interrupts | |
41a2d6cf IM |
8495 | * are serviced on a separate stack. It allows the architecture to switch the |
8496 | * notion of the current task on a cpu in a non-blocking manner. This function | |
1df5c10a LT |
8497 | * must be called with all CPU's synchronized, and interrupts disabled, the |
8498 | * and caller must save the original value of the current task (see | |
8499 | * curr_task() above) and restore that value before reenabling interrupts and | |
8500 | * re-starting the system. | |
8501 | * | |
8502 | * ONLY VALID WHEN THE WHOLE SYSTEM IS STOPPED! | |
8503 | */ | |
36c8b586 | 8504 | void set_curr_task(int cpu, struct task_struct *p) |
1df5c10a LT |
8505 | { |
8506 | cpu_curr(cpu) = p; | |
8507 | } | |
8508 | ||
8509 | #endif | |
29f59db3 | 8510 | |
bccbe08a PZ |
8511 | #ifdef CONFIG_FAIR_GROUP_SCHED |
8512 | static void free_fair_sched_group(struct task_group *tg) | |
6f505b16 PZ |
8513 | { |
8514 | int i; | |
8515 | ||
ab84d31e PT |
8516 | destroy_cfs_bandwidth(tg_cfs_bandwidth(tg)); |
8517 | ||
6f505b16 PZ |
8518 | for_each_possible_cpu(i) { |
8519 | if (tg->cfs_rq) | |
8520 | kfree(tg->cfs_rq[i]); | |
8521 | if (tg->se) | |
8522 | kfree(tg->se[i]); | |
6f505b16 PZ |
8523 | } |
8524 | ||
8525 | kfree(tg->cfs_rq); | |
8526 | kfree(tg->se); | |
6f505b16 PZ |
8527 | } |
8528 | ||
ec7dc8ac DG |
8529 | static |
8530 | int alloc_fair_sched_group(struct task_group *tg, struct task_group *parent) | |
29f59db3 | 8531 | { |
29f59db3 | 8532 | struct cfs_rq *cfs_rq; |
eab17229 | 8533 | struct sched_entity *se; |
29f59db3 SV |
8534 | int i; |
8535 | ||
434d53b0 | 8536 | tg->cfs_rq = kzalloc(sizeof(cfs_rq) * nr_cpu_ids, GFP_KERNEL); |
29f59db3 SV |
8537 | if (!tg->cfs_rq) |
8538 | goto err; | |
434d53b0 | 8539 | tg->se = kzalloc(sizeof(se) * nr_cpu_ids, GFP_KERNEL); |
29f59db3 SV |
8540 | if (!tg->se) |
8541 | goto err; | |
052f1dc7 PZ |
8542 | |
8543 | tg->shares = NICE_0_LOAD; | |
29f59db3 | 8544 | |
ab84d31e PT |
8545 | init_cfs_bandwidth(tg_cfs_bandwidth(tg)); |
8546 | ||
29f59db3 | 8547 | for_each_possible_cpu(i) { |
eab17229 LZ |
8548 | cfs_rq = kzalloc_node(sizeof(struct cfs_rq), |
8549 | GFP_KERNEL, cpu_to_node(i)); | |
29f59db3 SV |
8550 | if (!cfs_rq) |
8551 | goto err; | |
8552 | ||
eab17229 LZ |
8553 | se = kzalloc_node(sizeof(struct sched_entity), |
8554 | GFP_KERNEL, cpu_to_node(i)); | |
29f59db3 | 8555 | if (!se) |
dfc12eb2 | 8556 | goto err_free_rq; |
29f59db3 | 8557 | |
acb5a9ba | 8558 | init_cfs_rq(cfs_rq); |
3d4b47b4 | 8559 | init_tg_cfs_entry(tg, cfs_rq, se, i, parent->se[i]); |
bccbe08a PZ |
8560 | } |
8561 | ||
8562 | return 1; | |
8563 | ||
49246274 | 8564 | err_free_rq: |
dfc12eb2 | 8565 | kfree(cfs_rq); |
49246274 | 8566 | err: |
bccbe08a PZ |
8567 | return 0; |
8568 | } | |
8569 | ||
bccbe08a PZ |
8570 | static inline void unregister_fair_sched_group(struct task_group *tg, int cpu) |
8571 | { | |
3d4b47b4 PZ |
8572 | struct rq *rq = cpu_rq(cpu); |
8573 | unsigned long flags; | |
3d4b47b4 PZ |
8574 | |
8575 | /* | |
8576 | * Only empty task groups can be destroyed; so we can speculatively | |
8577 | * check on_list without danger of it being re-added. | |
8578 | */ | |
8579 | if (!tg->cfs_rq[cpu]->on_list) | |
8580 | return; | |
8581 | ||
8582 | raw_spin_lock_irqsave(&rq->lock, flags); | |
822bc180 | 8583 | list_del_leaf_cfs_rq(tg->cfs_rq[cpu]); |
3d4b47b4 | 8584 | raw_spin_unlock_irqrestore(&rq->lock, flags); |
bccbe08a | 8585 | } |
5f817d67 | 8586 | #else /* !CONFIG_FAIR_GROUP_SCHED */ |
bccbe08a PZ |
8587 | static inline void free_fair_sched_group(struct task_group *tg) |
8588 | { | |
8589 | } | |
8590 | ||
ec7dc8ac DG |
8591 | static inline |
8592 | int alloc_fair_sched_group(struct task_group *tg, struct task_group *parent) | |
bccbe08a PZ |
8593 | { |
8594 | return 1; | |
8595 | } | |
8596 | ||
bccbe08a PZ |
8597 | static inline void unregister_fair_sched_group(struct task_group *tg, int cpu) |
8598 | { | |
8599 | } | |
6d6bc0ad | 8600 | #endif /* CONFIG_FAIR_GROUP_SCHED */ |
052f1dc7 PZ |
8601 | |
8602 | #ifdef CONFIG_RT_GROUP_SCHED | |
bccbe08a PZ |
8603 | static void free_rt_sched_group(struct task_group *tg) |
8604 | { | |
8605 | int i; | |
8606 | ||
99bc5242 BL |
8607 | if (tg->rt_se) |
8608 | destroy_rt_bandwidth(&tg->rt_bandwidth); | |
d0b27fa7 | 8609 | |
bccbe08a PZ |
8610 | for_each_possible_cpu(i) { |
8611 | if (tg->rt_rq) | |
8612 | kfree(tg->rt_rq[i]); | |
8613 | if (tg->rt_se) | |
8614 | kfree(tg->rt_se[i]); | |
8615 | } | |
8616 | ||
8617 | kfree(tg->rt_rq); | |
8618 | kfree(tg->rt_se); | |
8619 | } | |
8620 | ||
ec7dc8ac DG |
8621 | static |
8622 | int alloc_rt_sched_group(struct task_group *tg, struct task_group *parent) | |
bccbe08a PZ |
8623 | { |
8624 | struct rt_rq *rt_rq; | |
eab17229 | 8625 | struct sched_rt_entity *rt_se; |
bccbe08a PZ |
8626 | int i; |
8627 | ||
434d53b0 | 8628 | tg->rt_rq = kzalloc(sizeof(rt_rq) * nr_cpu_ids, GFP_KERNEL); |
bccbe08a PZ |
8629 | if (!tg->rt_rq) |
8630 | goto err; | |
434d53b0 | 8631 | tg->rt_se = kzalloc(sizeof(rt_se) * nr_cpu_ids, GFP_KERNEL); |
bccbe08a PZ |
8632 | if (!tg->rt_se) |
8633 | goto err; | |
8634 | ||
d0b27fa7 PZ |
8635 | init_rt_bandwidth(&tg->rt_bandwidth, |
8636 | ktime_to_ns(def_rt_bandwidth.rt_period), 0); | |
bccbe08a PZ |
8637 | |
8638 | for_each_possible_cpu(i) { | |
eab17229 LZ |
8639 | rt_rq = kzalloc_node(sizeof(struct rt_rq), |
8640 | GFP_KERNEL, cpu_to_node(i)); | |
6f505b16 PZ |
8641 | if (!rt_rq) |
8642 | goto err; | |
29f59db3 | 8643 | |
eab17229 LZ |
8644 | rt_se = kzalloc_node(sizeof(struct sched_rt_entity), |
8645 | GFP_KERNEL, cpu_to_node(i)); | |
6f505b16 | 8646 | if (!rt_se) |
dfc12eb2 | 8647 | goto err_free_rq; |
29f59db3 | 8648 | |
acb5a9ba JS |
8649 | init_rt_rq(rt_rq, cpu_rq(i)); |
8650 | rt_rq->rt_runtime = tg->rt_bandwidth.rt_runtime; | |
3d4b47b4 | 8651 | init_tg_rt_entry(tg, rt_rq, rt_se, i, parent->rt_se[i]); |
29f59db3 SV |
8652 | } |
8653 | ||
bccbe08a PZ |
8654 | return 1; |
8655 | ||
49246274 | 8656 | err_free_rq: |
dfc12eb2 | 8657 | kfree(rt_rq); |
49246274 | 8658 | err: |
bccbe08a PZ |
8659 | return 0; |
8660 | } | |
6d6bc0ad | 8661 | #else /* !CONFIG_RT_GROUP_SCHED */ |
bccbe08a PZ |
8662 | static inline void free_rt_sched_group(struct task_group *tg) |
8663 | { | |
8664 | } | |
8665 | ||
ec7dc8ac DG |
8666 | static inline |
8667 | int alloc_rt_sched_group(struct task_group *tg, struct task_group *parent) | |
bccbe08a PZ |
8668 | { |
8669 | return 1; | |
8670 | } | |
6d6bc0ad | 8671 | #endif /* CONFIG_RT_GROUP_SCHED */ |
bccbe08a | 8672 | |
7c941438 | 8673 | #ifdef CONFIG_CGROUP_SCHED |
bccbe08a PZ |
8674 | static void free_sched_group(struct task_group *tg) |
8675 | { | |
8676 | free_fair_sched_group(tg); | |
8677 | free_rt_sched_group(tg); | |
e9aa1dd1 | 8678 | autogroup_free(tg); |
bccbe08a PZ |
8679 | kfree(tg); |
8680 | } | |
8681 | ||
8682 | /* allocate runqueue etc for a new task group */ | |
ec7dc8ac | 8683 | struct task_group *sched_create_group(struct task_group *parent) |
bccbe08a PZ |
8684 | { |
8685 | struct task_group *tg; | |
8686 | unsigned long flags; | |
bccbe08a PZ |
8687 | |
8688 | tg = kzalloc(sizeof(*tg), GFP_KERNEL); | |
8689 | if (!tg) | |
8690 | return ERR_PTR(-ENOMEM); | |
8691 | ||
ec7dc8ac | 8692 | if (!alloc_fair_sched_group(tg, parent)) |
bccbe08a PZ |
8693 | goto err; |
8694 | ||
ec7dc8ac | 8695 | if (!alloc_rt_sched_group(tg, parent)) |
bccbe08a PZ |
8696 | goto err; |
8697 | ||
8ed36996 | 8698 | spin_lock_irqsave(&task_group_lock, flags); |
6f505b16 | 8699 | list_add_rcu(&tg->list, &task_groups); |
f473aa5e PZ |
8700 | |
8701 | WARN_ON(!parent); /* root should already exist */ | |
8702 | ||
8703 | tg->parent = parent; | |
f473aa5e | 8704 | INIT_LIST_HEAD(&tg->children); |
09f2724a | 8705 | list_add_rcu(&tg->siblings, &parent->children); |
8ed36996 | 8706 | spin_unlock_irqrestore(&task_group_lock, flags); |
29f59db3 | 8707 | |
9b5b7751 | 8708 | return tg; |
29f59db3 SV |
8709 | |
8710 | err: | |
6f505b16 | 8711 | free_sched_group(tg); |
29f59db3 SV |
8712 | return ERR_PTR(-ENOMEM); |
8713 | } | |
8714 | ||
9b5b7751 | 8715 | /* rcu callback to free various structures associated with a task group */ |
6f505b16 | 8716 | static void free_sched_group_rcu(struct rcu_head *rhp) |
29f59db3 | 8717 | { |
29f59db3 | 8718 | /* now it should be safe to free those cfs_rqs */ |
6f505b16 | 8719 | free_sched_group(container_of(rhp, struct task_group, rcu)); |
29f59db3 SV |
8720 | } |
8721 | ||
9b5b7751 | 8722 | /* Destroy runqueue etc associated with a task group */ |
4cf86d77 | 8723 | void sched_destroy_group(struct task_group *tg) |
29f59db3 | 8724 | { |
8ed36996 | 8725 | unsigned long flags; |
9b5b7751 | 8726 | int i; |
29f59db3 | 8727 | |
3d4b47b4 PZ |
8728 | /* end participation in shares distribution */ |
8729 | for_each_possible_cpu(i) | |
bccbe08a | 8730 | unregister_fair_sched_group(tg, i); |
3d4b47b4 PZ |
8731 | |
8732 | spin_lock_irqsave(&task_group_lock, flags); | |
6f505b16 | 8733 | list_del_rcu(&tg->list); |
f473aa5e | 8734 | list_del_rcu(&tg->siblings); |
8ed36996 | 8735 | spin_unlock_irqrestore(&task_group_lock, flags); |
9b5b7751 | 8736 | |
9b5b7751 | 8737 | /* wait for possible concurrent references to cfs_rqs complete */ |
6f505b16 | 8738 | call_rcu(&tg->rcu, free_sched_group_rcu); |
29f59db3 SV |
8739 | } |
8740 | ||
9b5b7751 | 8741 | /* change task's runqueue when it moves between groups. |
3a252015 IM |
8742 | * The caller of this function should have put the task in its new group |
8743 | * by now. This function just updates tsk->se.cfs_rq and tsk->se.parent to | |
8744 | * reflect its new group. | |
9b5b7751 SV |
8745 | */ |
8746 | void sched_move_task(struct task_struct *tsk) | |
29f59db3 SV |
8747 | { |
8748 | int on_rq, running; | |
8749 | unsigned long flags; | |
8750 | struct rq *rq; | |
8751 | ||
8752 | rq = task_rq_lock(tsk, &flags); | |
8753 | ||
051a1d1a | 8754 | running = task_current(rq, tsk); |
fd2f4419 | 8755 | on_rq = tsk->on_rq; |
29f59db3 | 8756 | |
0e1f3483 | 8757 | if (on_rq) |
29f59db3 | 8758 | dequeue_task(rq, tsk, 0); |
0e1f3483 HS |
8759 | if (unlikely(running)) |
8760 | tsk->sched_class->put_prev_task(rq, tsk); | |
29f59db3 | 8761 | |
810b3817 | 8762 | #ifdef CONFIG_FAIR_GROUP_SCHED |
b2b5ce02 PZ |
8763 | if (tsk->sched_class->task_move_group) |
8764 | tsk->sched_class->task_move_group(tsk, on_rq); | |
8765 | else | |
810b3817 | 8766 | #endif |
b2b5ce02 | 8767 | set_task_rq(tsk, task_cpu(tsk)); |
810b3817 | 8768 | |
0e1f3483 HS |
8769 | if (unlikely(running)) |
8770 | tsk->sched_class->set_curr_task(rq); | |
8771 | if (on_rq) | |
371fd7e7 | 8772 | enqueue_task(rq, tsk, 0); |
29f59db3 | 8773 | |
0122ec5b | 8774 | task_rq_unlock(rq, tsk, &flags); |
29f59db3 | 8775 | } |
7c941438 | 8776 | #endif /* CONFIG_CGROUP_SCHED */ |
29f59db3 | 8777 | |
052f1dc7 | 8778 | #ifdef CONFIG_FAIR_GROUP_SCHED |
8ed36996 PZ |
8779 | static DEFINE_MUTEX(shares_mutex); |
8780 | ||
4cf86d77 | 8781 | int sched_group_set_shares(struct task_group *tg, unsigned long shares) |
29f59db3 SV |
8782 | { |
8783 | int i; | |
8ed36996 | 8784 | unsigned long flags; |
c61935fd | 8785 | |
ec7dc8ac DG |
8786 | /* |
8787 | * We can't change the weight of the root cgroup. | |
8788 | */ | |
8789 | if (!tg->se[0]) | |
8790 | return -EINVAL; | |
8791 | ||
cd62287e | 8792 | shares = clamp(shares, scale_load(MIN_SHARES), scale_load(MAX_SHARES)); |
62fb1851 | 8793 | |
8ed36996 | 8794 | mutex_lock(&shares_mutex); |
9b5b7751 | 8795 | if (tg->shares == shares) |
5cb350ba | 8796 | goto done; |
29f59db3 | 8797 | |
9b5b7751 | 8798 | tg->shares = shares; |
c09595f6 | 8799 | for_each_possible_cpu(i) { |
9437178f PT |
8800 | struct rq *rq = cpu_rq(i); |
8801 | struct sched_entity *se; | |
8802 | ||
8803 | se = tg->se[i]; | |
8804 | /* Propagate contribution to hierarchy */ | |
8805 | raw_spin_lock_irqsave(&rq->lock, flags); | |
8806 | for_each_sched_entity(se) | |
6d5ab293 | 8807 | update_cfs_shares(group_cfs_rq(se)); |
9437178f | 8808 | raw_spin_unlock_irqrestore(&rq->lock, flags); |
c09595f6 | 8809 | } |
29f59db3 | 8810 | |
5cb350ba | 8811 | done: |
8ed36996 | 8812 | mutex_unlock(&shares_mutex); |
9b5b7751 | 8813 | return 0; |
29f59db3 SV |
8814 | } |
8815 | ||
5cb350ba DG |
8816 | unsigned long sched_group_shares(struct task_group *tg) |
8817 | { | |
8818 | return tg->shares; | |
8819 | } | |
052f1dc7 | 8820 | #endif |
5cb350ba | 8821 | |
a790de99 | 8822 | #if defined(CONFIG_RT_GROUP_SCHED) || defined(CONFIG_CFS_BANDWIDTH) |
9f0c1e56 PZ |
8823 | static unsigned long to_ratio(u64 period, u64 runtime) |
8824 | { | |
8825 | if (runtime == RUNTIME_INF) | |
9a7e0b18 | 8826 | return 1ULL << 20; |
9f0c1e56 | 8827 | |
9a7e0b18 | 8828 | return div64_u64(runtime << 20, period); |
9f0c1e56 | 8829 | } |
a790de99 PT |
8830 | #endif |
8831 | ||
8832 | #ifdef CONFIG_RT_GROUP_SCHED | |
8833 | /* | |
8834 | * Ensure that the real time constraints are schedulable. | |
8835 | */ | |
8836 | static DEFINE_MUTEX(rt_constraints_mutex); | |
9f0c1e56 | 8837 | |
9a7e0b18 PZ |
8838 | /* Must be called with tasklist_lock held */ |
8839 | static inline int tg_has_rt_tasks(struct task_group *tg) | |
b40b2e8e | 8840 | { |
9a7e0b18 | 8841 | struct task_struct *g, *p; |
b40b2e8e | 8842 | |
9a7e0b18 PZ |
8843 | do_each_thread(g, p) { |
8844 | if (rt_task(p) && rt_rq_of_se(&p->rt)->tg == tg) | |
8845 | return 1; | |
8846 | } while_each_thread(g, p); | |
b40b2e8e | 8847 | |
9a7e0b18 PZ |
8848 | return 0; |
8849 | } | |
b40b2e8e | 8850 | |
9a7e0b18 PZ |
8851 | struct rt_schedulable_data { |
8852 | struct task_group *tg; | |
8853 | u64 rt_period; | |
8854 | u64 rt_runtime; | |
8855 | }; | |
b40b2e8e | 8856 | |
a790de99 | 8857 | static int tg_rt_schedulable(struct task_group *tg, void *data) |
9a7e0b18 PZ |
8858 | { |
8859 | struct rt_schedulable_data *d = data; | |
8860 | struct task_group *child; | |
8861 | unsigned long total, sum = 0; | |
8862 | u64 period, runtime; | |
b40b2e8e | 8863 | |
9a7e0b18 PZ |
8864 | period = ktime_to_ns(tg->rt_bandwidth.rt_period); |
8865 | runtime = tg->rt_bandwidth.rt_runtime; | |
b40b2e8e | 8866 | |
9a7e0b18 PZ |
8867 | if (tg == d->tg) { |
8868 | period = d->rt_period; | |
8869 | runtime = d->rt_runtime; | |
b40b2e8e | 8870 | } |
b40b2e8e | 8871 | |
4653f803 PZ |
8872 | /* |
8873 | * Cannot have more runtime than the period. | |
8874 | */ | |
8875 | if (runtime > period && runtime != RUNTIME_INF) | |
8876 | return -EINVAL; | |
6f505b16 | 8877 | |
4653f803 PZ |
8878 | /* |
8879 | * Ensure we don't starve existing RT tasks. | |
8880 | */ | |
9a7e0b18 PZ |
8881 | if (rt_bandwidth_enabled() && !runtime && tg_has_rt_tasks(tg)) |
8882 | return -EBUSY; | |
6f505b16 | 8883 | |
9a7e0b18 | 8884 | total = to_ratio(period, runtime); |
6f505b16 | 8885 | |
4653f803 PZ |
8886 | /* |
8887 | * Nobody can have more than the global setting allows. | |
8888 | */ | |
8889 | if (total > to_ratio(global_rt_period(), global_rt_runtime())) | |
8890 | return -EINVAL; | |
6f505b16 | 8891 | |
4653f803 PZ |
8892 | /* |
8893 | * The sum of our children's runtime should not exceed our own. | |
8894 | */ | |
9a7e0b18 PZ |
8895 | list_for_each_entry_rcu(child, &tg->children, siblings) { |
8896 | period = ktime_to_ns(child->rt_bandwidth.rt_period); | |
8897 | runtime = child->rt_bandwidth.rt_runtime; | |
6f505b16 | 8898 | |
9a7e0b18 PZ |
8899 | if (child == d->tg) { |
8900 | period = d->rt_period; | |
8901 | runtime = d->rt_runtime; | |
8902 | } | |
6f505b16 | 8903 | |
9a7e0b18 | 8904 | sum += to_ratio(period, runtime); |
9f0c1e56 | 8905 | } |
6f505b16 | 8906 | |
9a7e0b18 PZ |
8907 | if (sum > total) |
8908 | return -EINVAL; | |
8909 | ||
8910 | return 0; | |
6f505b16 PZ |
8911 | } |
8912 | ||
9a7e0b18 | 8913 | static int __rt_schedulable(struct task_group *tg, u64 period, u64 runtime) |
521f1a24 | 8914 | { |
8277434e PT |
8915 | int ret; |
8916 | ||
9a7e0b18 PZ |
8917 | struct rt_schedulable_data data = { |
8918 | .tg = tg, | |
8919 | .rt_period = period, | |
8920 | .rt_runtime = runtime, | |
8921 | }; | |
8922 | ||
8277434e PT |
8923 | rcu_read_lock(); |
8924 | ret = walk_tg_tree(tg_rt_schedulable, tg_nop, &data); | |
8925 | rcu_read_unlock(); | |
8926 | ||
8927 | return ret; | |
521f1a24 DG |
8928 | } |
8929 | ||
ab84d31e | 8930 | static int tg_set_rt_bandwidth(struct task_group *tg, |
d0b27fa7 | 8931 | u64 rt_period, u64 rt_runtime) |
6f505b16 | 8932 | { |
ac086bc2 | 8933 | int i, err = 0; |
9f0c1e56 | 8934 | |
9f0c1e56 | 8935 | mutex_lock(&rt_constraints_mutex); |
521f1a24 | 8936 | read_lock(&tasklist_lock); |
9a7e0b18 PZ |
8937 | err = __rt_schedulable(tg, rt_period, rt_runtime); |
8938 | if (err) | |
9f0c1e56 | 8939 | goto unlock; |
ac086bc2 | 8940 | |
0986b11b | 8941 | raw_spin_lock_irq(&tg->rt_bandwidth.rt_runtime_lock); |
d0b27fa7 PZ |
8942 | tg->rt_bandwidth.rt_period = ns_to_ktime(rt_period); |
8943 | tg->rt_bandwidth.rt_runtime = rt_runtime; | |
ac086bc2 PZ |
8944 | |
8945 | for_each_possible_cpu(i) { | |
8946 | struct rt_rq *rt_rq = tg->rt_rq[i]; | |
8947 | ||
0986b11b | 8948 | raw_spin_lock(&rt_rq->rt_runtime_lock); |
ac086bc2 | 8949 | rt_rq->rt_runtime = rt_runtime; |
0986b11b | 8950 | raw_spin_unlock(&rt_rq->rt_runtime_lock); |
ac086bc2 | 8951 | } |
0986b11b | 8952 | raw_spin_unlock_irq(&tg->rt_bandwidth.rt_runtime_lock); |
49246274 | 8953 | unlock: |
521f1a24 | 8954 | read_unlock(&tasklist_lock); |
9f0c1e56 PZ |
8955 | mutex_unlock(&rt_constraints_mutex); |
8956 | ||
8957 | return err; | |
6f505b16 PZ |
8958 | } |
8959 | ||
d0b27fa7 PZ |
8960 | int sched_group_set_rt_runtime(struct task_group *tg, long rt_runtime_us) |
8961 | { | |
8962 | u64 rt_runtime, rt_period; | |
8963 | ||
8964 | rt_period = ktime_to_ns(tg->rt_bandwidth.rt_period); | |
8965 | rt_runtime = (u64)rt_runtime_us * NSEC_PER_USEC; | |
8966 | if (rt_runtime_us < 0) | |
8967 | rt_runtime = RUNTIME_INF; | |
8968 | ||
ab84d31e | 8969 | return tg_set_rt_bandwidth(tg, rt_period, rt_runtime); |
d0b27fa7 PZ |
8970 | } |
8971 | ||
9f0c1e56 PZ |
8972 | long sched_group_rt_runtime(struct task_group *tg) |
8973 | { | |
8974 | u64 rt_runtime_us; | |
8975 | ||
d0b27fa7 | 8976 | if (tg->rt_bandwidth.rt_runtime == RUNTIME_INF) |
9f0c1e56 PZ |
8977 | return -1; |
8978 | ||
d0b27fa7 | 8979 | rt_runtime_us = tg->rt_bandwidth.rt_runtime; |
9f0c1e56 PZ |
8980 | do_div(rt_runtime_us, NSEC_PER_USEC); |
8981 | return rt_runtime_us; | |
8982 | } | |
d0b27fa7 PZ |
8983 | |
8984 | int sched_group_set_rt_period(struct task_group *tg, long rt_period_us) | |
8985 | { | |
8986 | u64 rt_runtime, rt_period; | |
8987 | ||
8988 | rt_period = (u64)rt_period_us * NSEC_PER_USEC; | |
8989 | rt_runtime = tg->rt_bandwidth.rt_runtime; | |
8990 | ||
619b0488 R |
8991 | if (rt_period == 0) |
8992 | return -EINVAL; | |
8993 | ||
ab84d31e | 8994 | return tg_set_rt_bandwidth(tg, rt_period, rt_runtime); |
d0b27fa7 PZ |
8995 | } |
8996 | ||
8997 | long sched_group_rt_period(struct task_group *tg) | |
8998 | { | |
8999 | u64 rt_period_us; | |
9000 | ||
9001 | rt_period_us = ktime_to_ns(tg->rt_bandwidth.rt_period); | |
9002 | do_div(rt_period_us, NSEC_PER_USEC); | |
9003 | return rt_period_us; | |
9004 | } | |
9005 | ||
9006 | static int sched_rt_global_constraints(void) | |
9007 | { | |
4653f803 | 9008 | u64 runtime, period; |
d0b27fa7 PZ |
9009 | int ret = 0; |
9010 | ||
ec5d4989 HS |
9011 | if (sysctl_sched_rt_period <= 0) |
9012 | return -EINVAL; | |
9013 | ||
4653f803 PZ |
9014 | runtime = global_rt_runtime(); |
9015 | period = global_rt_period(); | |
9016 | ||
9017 | /* | |
9018 | * Sanity check on the sysctl variables. | |
9019 | */ | |
9020 | if (runtime > period && runtime != RUNTIME_INF) | |
9021 | return -EINVAL; | |
10b612f4 | 9022 | |
d0b27fa7 | 9023 | mutex_lock(&rt_constraints_mutex); |
9a7e0b18 | 9024 | read_lock(&tasklist_lock); |
4653f803 | 9025 | ret = __rt_schedulable(NULL, 0, 0); |
9a7e0b18 | 9026 | read_unlock(&tasklist_lock); |
d0b27fa7 PZ |
9027 | mutex_unlock(&rt_constraints_mutex); |
9028 | ||
9029 | return ret; | |
9030 | } | |
54e99124 DG |
9031 | |
9032 | int sched_rt_can_attach(struct task_group *tg, struct task_struct *tsk) | |
9033 | { | |
9034 | /* Don't accept realtime tasks when there is no way for them to run */ | |
9035 | if (rt_task(tsk) && tg->rt_bandwidth.rt_runtime == 0) | |
9036 | return 0; | |
9037 | ||
9038 | return 1; | |
9039 | } | |
9040 | ||
6d6bc0ad | 9041 | #else /* !CONFIG_RT_GROUP_SCHED */ |
d0b27fa7 PZ |
9042 | static int sched_rt_global_constraints(void) |
9043 | { | |
ac086bc2 PZ |
9044 | unsigned long flags; |
9045 | int i; | |
9046 | ||
ec5d4989 HS |
9047 | if (sysctl_sched_rt_period <= 0) |
9048 | return -EINVAL; | |
9049 | ||
60aa605d PZ |
9050 | /* |
9051 | * There's always some RT tasks in the root group | |
9052 | * -- migration, kstopmachine etc.. | |
9053 | */ | |
9054 | if (sysctl_sched_rt_runtime == 0) | |
9055 | return -EBUSY; | |
9056 | ||
0986b11b | 9057 | raw_spin_lock_irqsave(&def_rt_bandwidth.rt_runtime_lock, flags); |
ac086bc2 PZ |
9058 | for_each_possible_cpu(i) { |
9059 | struct rt_rq *rt_rq = &cpu_rq(i)->rt; | |
9060 | ||
0986b11b | 9061 | raw_spin_lock(&rt_rq->rt_runtime_lock); |
ac086bc2 | 9062 | rt_rq->rt_runtime = global_rt_runtime(); |
0986b11b | 9063 | raw_spin_unlock(&rt_rq->rt_runtime_lock); |
ac086bc2 | 9064 | } |
0986b11b | 9065 | raw_spin_unlock_irqrestore(&def_rt_bandwidth.rt_runtime_lock, flags); |
ac086bc2 | 9066 | |
d0b27fa7 PZ |
9067 | return 0; |
9068 | } | |
6d6bc0ad | 9069 | #endif /* CONFIG_RT_GROUP_SCHED */ |
d0b27fa7 PZ |
9070 | |
9071 | int sched_rt_handler(struct ctl_table *table, int write, | |
8d65af78 | 9072 | void __user *buffer, size_t *lenp, |
d0b27fa7 PZ |
9073 | loff_t *ppos) |
9074 | { | |
9075 | int ret; | |
9076 | int old_period, old_runtime; | |
9077 | static DEFINE_MUTEX(mutex); | |
9078 | ||
9079 | mutex_lock(&mutex); | |
9080 | old_period = sysctl_sched_rt_period; | |
9081 | old_runtime = sysctl_sched_rt_runtime; | |
9082 | ||
8d65af78 | 9083 | ret = proc_dointvec(table, write, buffer, lenp, ppos); |
d0b27fa7 PZ |
9084 | |
9085 | if (!ret && write) { | |
9086 | ret = sched_rt_global_constraints(); | |
9087 | if (ret) { | |
9088 | sysctl_sched_rt_period = old_period; | |
9089 | sysctl_sched_rt_runtime = old_runtime; | |
9090 | } else { | |
9091 | def_rt_bandwidth.rt_runtime = global_rt_runtime(); | |
9092 | def_rt_bandwidth.rt_period = | |
9093 | ns_to_ktime(global_rt_period()); | |
9094 | } | |
9095 | } | |
9096 | mutex_unlock(&mutex); | |
9097 | ||
9098 | return ret; | |
9099 | } | |
68318b8e | 9100 | |
052f1dc7 | 9101 | #ifdef CONFIG_CGROUP_SCHED |
68318b8e SV |
9102 | |
9103 | /* return corresponding task_group object of a cgroup */ | |
2b01dfe3 | 9104 | static inline struct task_group *cgroup_tg(struct cgroup *cgrp) |
68318b8e | 9105 | { |
2b01dfe3 PM |
9106 | return container_of(cgroup_subsys_state(cgrp, cpu_cgroup_subsys_id), |
9107 | struct task_group, css); | |
68318b8e SV |
9108 | } |
9109 | ||
9110 | static struct cgroup_subsys_state * | |
2b01dfe3 | 9111 | cpu_cgroup_create(struct cgroup_subsys *ss, struct cgroup *cgrp) |
68318b8e | 9112 | { |
ec7dc8ac | 9113 | struct task_group *tg, *parent; |
68318b8e | 9114 | |
2b01dfe3 | 9115 | if (!cgrp->parent) { |
68318b8e | 9116 | /* This is early initialization for the top cgroup */ |
07e06b01 | 9117 | return &root_task_group.css; |
68318b8e SV |
9118 | } |
9119 | ||
ec7dc8ac DG |
9120 | parent = cgroup_tg(cgrp->parent); |
9121 | tg = sched_create_group(parent); | |
68318b8e SV |
9122 | if (IS_ERR(tg)) |
9123 | return ERR_PTR(-ENOMEM); | |
9124 | ||
68318b8e SV |
9125 | return &tg->css; |
9126 | } | |
9127 | ||
41a2d6cf IM |
9128 | static void |
9129 | cpu_cgroup_destroy(struct cgroup_subsys *ss, struct cgroup *cgrp) | |
68318b8e | 9130 | { |
2b01dfe3 | 9131 | struct task_group *tg = cgroup_tg(cgrp); |
68318b8e SV |
9132 | |
9133 | sched_destroy_group(tg); | |
9134 | } | |
9135 | ||
41a2d6cf | 9136 | static int |
be367d09 | 9137 | cpu_cgroup_can_attach_task(struct cgroup *cgrp, struct task_struct *tsk) |
68318b8e | 9138 | { |
b68aa230 | 9139 | #ifdef CONFIG_RT_GROUP_SCHED |
54e99124 | 9140 | if (!sched_rt_can_attach(cgroup_tg(cgrp), tsk)) |
b68aa230 PZ |
9141 | return -EINVAL; |
9142 | #else | |
68318b8e SV |
9143 | /* We don't support RT-tasks being in separate groups */ |
9144 | if (tsk->sched_class != &fair_sched_class) | |
9145 | return -EINVAL; | |
b68aa230 | 9146 | #endif |
be367d09 BB |
9147 | return 0; |
9148 | } | |
68318b8e | 9149 | |
68318b8e | 9150 | static void |
f780bdb7 | 9151 | cpu_cgroup_attach_task(struct cgroup *cgrp, struct task_struct *tsk) |
68318b8e SV |
9152 | { |
9153 | sched_move_task(tsk); | |
9154 | } | |
9155 | ||
068c5cc5 | 9156 | static void |
d41d5a01 PZ |
9157 | cpu_cgroup_exit(struct cgroup_subsys *ss, struct cgroup *cgrp, |
9158 | struct cgroup *old_cgrp, struct task_struct *task) | |
068c5cc5 PZ |
9159 | { |
9160 | /* | |
9161 | * cgroup_exit() is called in the copy_process() failure path. | |
9162 | * Ignore this case since the task hasn't ran yet, this avoids | |
9163 | * trying to poke a half freed task state from generic code. | |
9164 | */ | |
9165 | if (!(task->flags & PF_EXITING)) | |
9166 | return; | |
9167 | ||
9168 | sched_move_task(task); | |
9169 | } | |
9170 | ||
052f1dc7 | 9171 | #ifdef CONFIG_FAIR_GROUP_SCHED |
f4c753b7 | 9172 | static int cpu_shares_write_u64(struct cgroup *cgrp, struct cftype *cftype, |
2b01dfe3 | 9173 | u64 shareval) |
68318b8e | 9174 | { |
c8b28116 | 9175 | return sched_group_set_shares(cgroup_tg(cgrp), scale_load(shareval)); |
68318b8e SV |
9176 | } |
9177 | ||
f4c753b7 | 9178 | static u64 cpu_shares_read_u64(struct cgroup *cgrp, struct cftype *cft) |
68318b8e | 9179 | { |
2b01dfe3 | 9180 | struct task_group *tg = cgroup_tg(cgrp); |
68318b8e | 9181 | |
c8b28116 | 9182 | return (u64) scale_load_down(tg->shares); |
68318b8e | 9183 | } |
ab84d31e PT |
9184 | |
9185 | #ifdef CONFIG_CFS_BANDWIDTH | |
a790de99 PT |
9186 | static DEFINE_MUTEX(cfs_constraints_mutex); |
9187 | ||
ab84d31e PT |
9188 | const u64 max_cfs_quota_period = 1 * NSEC_PER_SEC; /* 1s */ |
9189 | const u64 min_cfs_quota_period = 1 * NSEC_PER_MSEC; /* 1ms */ | |
9190 | ||
a790de99 PT |
9191 | static int __cfs_schedulable(struct task_group *tg, u64 period, u64 runtime); |
9192 | ||
ab84d31e PT |
9193 | static int tg_set_cfs_bandwidth(struct task_group *tg, u64 period, u64 quota) |
9194 | { | |
58088ad0 | 9195 | int i, ret = 0, runtime_enabled; |
ab84d31e | 9196 | struct cfs_bandwidth *cfs_b = tg_cfs_bandwidth(tg); |
ab84d31e PT |
9197 | |
9198 | if (tg == &root_task_group) | |
9199 | return -EINVAL; | |
9200 | ||
9201 | /* | |
9202 | * Ensure we have at some amount of bandwidth every period. This is | |
9203 | * to prevent reaching a state of large arrears when throttled via | |
9204 | * entity_tick() resulting in prolonged exit starvation. | |
9205 | */ | |
9206 | if (quota < min_cfs_quota_period || period < min_cfs_quota_period) | |
9207 | return -EINVAL; | |
9208 | ||
9209 | /* | |
9210 | * Likewise, bound things on the otherside by preventing insane quota | |
9211 | * periods. This also allows us to normalize in computing quota | |
9212 | * feasibility. | |
9213 | */ | |
9214 | if (period > max_cfs_quota_period) | |
9215 | return -EINVAL; | |
9216 | ||
a790de99 PT |
9217 | mutex_lock(&cfs_constraints_mutex); |
9218 | ret = __cfs_schedulable(tg, period, quota); | |
9219 | if (ret) | |
9220 | goto out_unlock; | |
9221 | ||
58088ad0 | 9222 | runtime_enabled = quota != RUNTIME_INF; |
ab84d31e PT |
9223 | raw_spin_lock_irq(&cfs_b->lock); |
9224 | cfs_b->period = ns_to_ktime(period); | |
9225 | cfs_b->quota = quota; | |
58088ad0 | 9226 | |
a9cf55b2 | 9227 | __refill_cfs_bandwidth_runtime(cfs_b); |
58088ad0 PT |
9228 | /* restart the period timer (if active) to handle new period expiry */ |
9229 | if (runtime_enabled && cfs_b->timer_active) { | |
9230 | /* force a reprogram */ | |
9231 | cfs_b->timer_active = 0; | |
9232 | __start_cfs_bandwidth(cfs_b); | |
9233 | } | |
ab84d31e PT |
9234 | raw_spin_unlock_irq(&cfs_b->lock); |
9235 | ||
9236 | for_each_possible_cpu(i) { | |
9237 | struct cfs_rq *cfs_rq = tg->cfs_rq[i]; | |
9238 | struct rq *rq = rq_of(cfs_rq); | |
9239 | ||
9240 | raw_spin_lock_irq(&rq->lock); | |
58088ad0 | 9241 | cfs_rq->runtime_enabled = runtime_enabled; |
ab84d31e | 9242 | cfs_rq->runtime_remaining = 0; |
671fd9da PT |
9243 | |
9244 | if (cfs_rq_throttled(cfs_rq)) | |
9245 | unthrottle_cfs_rq(cfs_rq); | |
ab84d31e PT |
9246 | raw_spin_unlock_irq(&rq->lock); |
9247 | } | |
a790de99 PT |
9248 | out_unlock: |
9249 | mutex_unlock(&cfs_constraints_mutex); | |
ab84d31e | 9250 | |
a790de99 | 9251 | return ret; |
ab84d31e PT |
9252 | } |
9253 | ||
9254 | int tg_set_cfs_quota(struct task_group *tg, long cfs_quota_us) | |
9255 | { | |
9256 | u64 quota, period; | |
9257 | ||
9258 | period = ktime_to_ns(tg_cfs_bandwidth(tg)->period); | |
9259 | if (cfs_quota_us < 0) | |
9260 | quota = RUNTIME_INF; | |
9261 | else | |
9262 | quota = (u64)cfs_quota_us * NSEC_PER_USEC; | |
9263 | ||
9264 | return tg_set_cfs_bandwidth(tg, period, quota); | |
9265 | } | |
9266 | ||
9267 | long tg_get_cfs_quota(struct task_group *tg) | |
9268 | { | |
9269 | u64 quota_us; | |
9270 | ||
9271 | if (tg_cfs_bandwidth(tg)->quota == RUNTIME_INF) | |
9272 | return -1; | |
9273 | ||
9274 | quota_us = tg_cfs_bandwidth(tg)->quota; | |
9275 | do_div(quota_us, NSEC_PER_USEC); | |
9276 | ||
9277 | return quota_us; | |
9278 | } | |
9279 | ||
9280 | int tg_set_cfs_period(struct task_group *tg, long cfs_period_us) | |
9281 | { | |
9282 | u64 quota, period; | |
9283 | ||
9284 | period = (u64)cfs_period_us * NSEC_PER_USEC; | |
9285 | quota = tg_cfs_bandwidth(tg)->quota; | |
9286 | ||
9287 | if (period <= 0) | |
9288 | return -EINVAL; | |
9289 | ||
9290 | return tg_set_cfs_bandwidth(tg, period, quota); | |
9291 | } | |
9292 | ||
9293 | long tg_get_cfs_period(struct task_group *tg) | |
9294 | { | |
9295 | u64 cfs_period_us; | |
9296 | ||
9297 | cfs_period_us = ktime_to_ns(tg_cfs_bandwidth(tg)->period); | |
9298 | do_div(cfs_period_us, NSEC_PER_USEC); | |
9299 | ||
9300 | return cfs_period_us; | |
9301 | } | |
9302 | ||
9303 | static s64 cpu_cfs_quota_read_s64(struct cgroup *cgrp, struct cftype *cft) | |
9304 | { | |
9305 | return tg_get_cfs_quota(cgroup_tg(cgrp)); | |
9306 | } | |
9307 | ||
9308 | static int cpu_cfs_quota_write_s64(struct cgroup *cgrp, struct cftype *cftype, | |
9309 | s64 cfs_quota_us) | |
9310 | { | |
9311 | return tg_set_cfs_quota(cgroup_tg(cgrp), cfs_quota_us); | |
9312 | } | |
9313 | ||
9314 | static u64 cpu_cfs_period_read_u64(struct cgroup *cgrp, struct cftype *cft) | |
9315 | { | |
9316 | return tg_get_cfs_period(cgroup_tg(cgrp)); | |
9317 | } | |
9318 | ||
9319 | static int cpu_cfs_period_write_u64(struct cgroup *cgrp, struct cftype *cftype, | |
9320 | u64 cfs_period_us) | |
9321 | { | |
9322 | return tg_set_cfs_period(cgroup_tg(cgrp), cfs_period_us); | |
9323 | } | |
9324 | ||
a790de99 PT |
9325 | struct cfs_schedulable_data { |
9326 | struct task_group *tg; | |
9327 | u64 period, quota; | |
9328 | }; | |
9329 | ||
9330 | /* | |
9331 | * normalize group quota/period to be quota/max_period | |
9332 | * note: units are usecs | |
9333 | */ | |
9334 | static u64 normalize_cfs_quota(struct task_group *tg, | |
9335 | struct cfs_schedulable_data *d) | |
9336 | { | |
9337 | u64 quota, period; | |
9338 | ||
9339 | if (tg == d->tg) { | |
9340 | period = d->period; | |
9341 | quota = d->quota; | |
9342 | } else { | |
9343 | period = tg_get_cfs_period(tg); | |
9344 | quota = tg_get_cfs_quota(tg); | |
9345 | } | |
9346 | ||
9347 | /* note: these should typically be equivalent */ | |
9348 | if (quota == RUNTIME_INF || quota == -1) | |
9349 | return RUNTIME_INF; | |
9350 | ||
9351 | return to_ratio(period, quota); | |
9352 | } | |
9353 | ||
9354 | static int tg_cfs_schedulable_down(struct task_group *tg, void *data) | |
9355 | { | |
9356 | struct cfs_schedulable_data *d = data; | |
9357 | struct cfs_bandwidth *cfs_b = tg_cfs_bandwidth(tg); | |
9358 | s64 quota = 0, parent_quota = -1; | |
9359 | ||
9360 | if (!tg->parent) { | |
9361 | quota = RUNTIME_INF; | |
9362 | } else { | |
9363 | struct cfs_bandwidth *parent_b = tg_cfs_bandwidth(tg->parent); | |
9364 | ||
9365 | quota = normalize_cfs_quota(tg, d); | |
9366 | parent_quota = parent_b->hierarchal_quota; | |
9367 | ||
9368 | /* | |
9369 | * ensure max(child_quota) <= parent_quota, inherit when no | |
9370 | * limit is set | |
9371 | */ | |
9372 | if (quota == RUNTIME_INF) | |
9373 | quota = parent_quota; | |
9374 | else if (parent_quota != RUNTIME_INF && quota > parent_quota) | |
9375 | return -EINVAL; | |
9376 | } | |
9377 | cfs_b->hierarchal_quota = quota; | |
9378 | ||
9379 | return 0; | |
9380 | } | |
9381 | ||
9382 | static int __cfs_schedulable(struct task_group *tg, u64 period, u64 quota) | |
9383 | { | |
8277434e | 9384 | int ret; |
a790de99 PT |
9385 | struct cfs_schedulable_data data = { |
9386 | .tg = tg, | |
9387 | .period = period, | |
9388 | .quota = quota, | |
9389 | }; | |
9390 | ||
9391 | if (quota != RUNTIME_INF) { | |
9392 | do_div(data.period, NSEC_PER_USEC); | |
9393 | do_div(data.quota, NSEC_PER_USEC); | |
9394 | } | |
9395 | ||
8277434e PT |
9396 | rcu_read_lock(); |
9397 | ret = walk_tg_tree(tg_cfs_schedulable_down, tg_nop, &data); | |
9398 | rcu_read_unlock(); | |
9399 | ||
9400 | return ret; | |
a790de99 | 9401 | } |
e8da1b18 NR |
9402 | |
9403 | static int cpu_stats_show(struct cgroup *cgrp, struct cftype *cft, | |
9404 | struct cgroup_map_cb *cb) | |
9405 | { | |
9406 | struct task_group *tg = cgroup_tg(cgrp); | |
9407 | struct cfs_bandwidth *cfs_b = tg_cfs_bandwidth(tg); | |
9408 | ||
9409 | cb->fill(cb, "nr_periods", cfs_b->nr_periods); | |
9410 | cb->fill(cb, "nr_throttled", cfs_b->nr_throttled); | |
9411 | cb->fill(cb, "throttled_time", cfs_b->throttled_time); | |
9412 | ||
9413 | return 0; | |
9414 | } | |
ab84d31e | 9415 | #endif /* CONFIG_CFS_BANDWIDTH */ |
6d6bc0ad | 9416 | #endif /* CONFIG_FAIR_GROUP_SCHED */ |
68318b8e | 9417 | |
052f1dc7 | 9418 | #ifdef CONFIG_RT_GROUP_SCHED |
0c70814c | 9419 | static int cpu_rt_runtime_write(struct cgroup *cgrp, struct cftype *cft, |
06ecb27c | 9420 | s64 val) |
6f505b16 | 9421 | { |
06ecb27c | 9422 | return sched_group_set_rt_runtime(cgroup_tg(cgrp), val); |
6f505b16 PZ |
9423 | } |
9424 | ||
06ecb27c | 9425 | static s64 cpu_rt_runtime_read(struct cgroup *cgrp, struct cftype *cft) |
6f505b16 | 9426 | { |
06ecb27c | 9427 | return sched_group_rt_runtime(cgroup_tg(cgrp)); |
6f505b16 | 9428 | } |
d0b27fa7 PZ |
9429 | |
9430 | static int cpu_rt_period_write_uint(struct cgroup *cgrp, struct cftype *cftype, | |
9431 | u64 rt_period_us) | |
9432 | { | |
9433 | return sched_group_set_rt_period(cgroup_tg(cgrp), rt_period_us); | |
9434 | } | |
9435 | ||
9436 | static u64 cpu_rt_period_read_uint(struct cgroup *cgrp, struct cftype *cft) | |
9437 | { | |
9438 | return sched_group_rt_period(cgroup_tg(cgrp)); | |
9439 | } | |
6d6bc0ad | 9440 | #endif /* CONFIG_RT_GROUP_SCHED */ |
6f505b16 | 9441 | |
fe5c7cc2 | 9442 | static struct cftype cpu_files[] = { |
052f1dc7 | 9443 | #ifdef CONFIG_FAIR_GROUP_SCHED |
fe5c7cc2 PM |
9444 | { |
9445 | .name = "shares", | |
f4c753b7 PM |
9446 | .read_u64 = cpu_shares_read_u64, |
9447 | .write_u64 = cpu_shares_write_u64, | |
fe5c7cc2 | 9448 | }, |
052f1dc7 | 9449 | #endif |
ab84d31e PT |
9450 | #ifdef CONFIG_CFS_BANDWIDTH |
9451 | { | |
9452 | .name = "cfs_quota_us", | |
9453 | .read_s64 = cpu_cfs_quota_read_s64, | |
9454 | .write_s64 = cpu_cfs_quota_write_s64, | |
9455 | }, | |
9456 | { | |
9457 | .name = "cfs_period_us", | |
9458 | .read_u64 = cpu_cfs_period_read_u64, | |
9459 | .write_u64 = cpu_cfs_period_write_u64, | |
9460 | }, | |
e8da1b18 NR |
9461 | { |
9462 | .name = "stat", | |
9463 | .read_map = cpu_stats_show, | |
9464 | }, | |
ab84d31e | 9465 | #endif |
052f1dc7 | 9466 | #ifdef CONFIG_RT_GROUP_SCHED |
6f505b16 | 9467 | { |
9f0c1e56 | 9468 | .name = "rt_runtime_us", |
06ecb27c PM |
9469 | .read_s64 = cpu_rt_runtime_read, |
9470 | .write_s64 = cpu_rt_runtime_write, | |
6f505b16 | 9471 | }, |
d0b27fa7 PZ |
9472 | { |
9473 | .name = "rt_period_us", | |
f4c753b7 PM |
9474 | .read_u64 = cpu_rt_period_read_uint, |
9475 | .write_u64 = cpu_rt_period_write_uint, | |
d0b27fa7 | 9476 | }, |
052f1dc7 | 9477 | #endif |
68318b8e SV |
9478 | }; |
9479 | ||
9480 | static int cpu_cgroup_populate(struct cgroup_subsys *ss, struct cgroup *cont) | |
9481 | { | |
fe5c7cc2 | 9482 | return cgroup_add_files(cont, ss, cpu_files, ARRAY_SIZE(cpu_files)); |
68318b8e SV |
9483 | } |
9484 | ||
9485 | struct cgroup_subsys cpu_cgroup_subsys = { | |
38605cae IM |
9486 | .name = "cpu", |
9487 | .create = cpu_cgroup_create, | |
9488 | .destroy = cpu_cgroup_destroy, | |
f780bdb7 BB |
9489 | .can_attach_task = cpu_cgroup_can_attach_task, |
9490 | .attach_task = cpu_cgroup_attach_task, | |
068c5cc5 | 9491 | .exit = cpu_cgroup_exit, |
38605cae IM |
9492 | .populate = cpu_cgroup_populate, |
9493 | .subsys_id = cpu_cgroup_subsys_id, | |
68318b8e SV |
9494 | .early_init = 1, |
9495 | }; | |
9496 | ||
052f1dc7 | 9497 | #endif /* CONFIG_CGROUP_SCHED */ |
d842de87 SV |
9498 | |
9499 | #ifdef CONFIG_CGROUP_CPUACCT | |
9500 | ||
9501 | /* | |
9502 | * CPU accounting code for task groups. | |
9503 | * | |
9504 | * Based on the work by Paul Menage (menage@google.com) and Balbir Singh | |
9505 | * (balbir@in.ibm.com). | |
9506 | */ | |
9507 | ||
934352f2 | 9508 | /* track cpu usage of a group of tasks and its child groups */ |
d842de87 SV |
9509 | struct cpuacct { |
9510 | struct cgroup_subsys_state css; | |
9511 | /* cpuusage holds pointer to a u64-type object on every cpu */ | |
43cf38eb | 9512 | u64 __percpu *cpuusage; |
ef12fefa | 9513 | struct percpu_counter cpustat[CPUACCT_STAT_NSTATS]; |
934352f2 | 9514 | struct cpuacct *parent; |
d842de87 SV |
9515 | }; |
9516 | ||
9517 | struct cgroup_subsys cpuacct_subsys; | |
9518 | ||
9519 | /* return cpu accounting group corresponding to this container */ | |
32cd756a | 9520 | static inline struct cpuacct *cgroup_ca(struct cgroup *cgrp) |
d842de87 | 9521 | { |
32cd756a | 9522 | return container_of(cgroup_subsys_state(cgrp, cpuacct_subsys_id), |
d842de87 SV |
9523 | struct cpuacct, css); |
9524 | } | |
9525 | ||
9526 | /* return cpu accounting group to which this task belongs */ | |
9527 | static inline struct cpuacct *task_ca(struct task_struct *tsk) | |
9528 | { | |
9529 | return container_of(task_subsys_state(tsk, cpuacct_subsys_id), | |
9530 | struct cpuacct, css); | |
9531 | } | |
9532 | ||
9533 | /* create a new cpu accounting group */ | |
9534 | static struct cgroup_subsys_state *cpuacct_create( | |
32cd756a | 9535 | struct cgroup_subsys *ss, struct cgroup *cgrp) |
d842de87 SV |
9536 | { |
9537 | struct cpuacct *ca = kzalloc(sizeof(*ca), GFP_KERNEL); | |
ef12fefa | 9538 | int i; |
d842de87 SV |
9539 | |
9540 | if (!ca) | |
ef12fefa | 9541 | goto out; |
d842de87 SV |
9542 | |
9543 | ca->cpuusage = alloc_percpu(u64); | |
ef12fefa BR |
9544 | if (!ca->cpuusage) |
9545 | goto out_free_ca; | |
9546 | ||
9547 | for (i = 0; i < CPUACCT_STAT_NSTATS; i++) | |
9548 | if (percpu_counter_init(&ca->cpustat[i], 0)) | |
9549 | goto out_free_counters; | |
d842de87 | 9550 | |
934352f2 BR |
9551 | if (cgrp->parent) |
9552 | ca->parent = cgroup_ca(cgrp->parent); | |
9553 | ||
d842de87 | 9554 | return &ca->css; |
ef12fefa BR |
9555 | |
9556 | out_free_counters: | |
9557 | while (--i >= 0) | |
9558 | percpu_counter_destroy(&ca->cpustat[i]); | |
9559 | free_percpu(ca->cpuusage); | |
9560 | out_free_ca: | |
9561 | kfree(ca); | |
9562 | out: | |
9563 | return ERR_PTR(-ENOMEM); | |
d842de87 SV |
9564 | } |
9565 | ||
9566 | /* destroy an existing cpu accounting group */ | |
41a2d6cf | 9567 | static void |
32cd756a | 9568 | cpuacct_destroy(struct cgroup_subsys *ss, struct cgroup *cgrp) |
d842de87 | 9569 | { |
32cd756a | 9570 | struct cpuacct *ca = cgroup_ca(cgrp); |
ef12fefa | 9571 | int i; |
d842de87 | 9572 | |
ef12fefa BR |
9573 | for (i = 0; i < CPUACCT_STAT_NSTATS; i++) |
9574 | percpu_counter_destroy(&ca->cpustat[i]); | |
d842de87 SV |
9575 | free_percpu(ca->cpuusage); |
9576 | kfree(ca); | |
9577 | } | |
9578 | ||
720f5498 KC |
9579 | static u64 cpuacct_cpuusage_read(struct cpuacct *ca, int cpu) |
9580 | { | |
b36128c8 | 9581 | u64 *cpuusage = per_cpu_ptr(ca->cpuusage, cpu); |
720f5498 KC |
9582 | u64 data; |
9583 | ||
9584 | #ifndef CONFIG_64BIT | |
9585 | /* | |
9586 | * Take rq->lock to make 64-bit read safe on 32-bit platforms. | |
9587 | */ | |
05fa785c | 9588 | raw_spin_lock_irq(&cpu_rq(cpu)->lock); |
720f5498 | 9589 | data = *cpuusage; |
05fa785c | 9590 | raw_spin_unlock_irq(&cpu_rq(cpu)->lock); |
720f5498 KC |
9591 | #else |
9592 | data = *cpuusage; | |
9593 | #endif | |
9594 | ||
9595 | return data; | |
9596 | } | |
9597 | ||
9598 | static void cpuacct_cpuusage_write(struct cpuacct *ca, int cpu, u64 val) | |
9599 | { | |
b36128c8 | 9600 | u64 *cpuusage = per_cpu_ptr(ca->cpuusage, cpu); |
720f5498 KC |
9601 | |
9602 | #ifndef CONFIG_64BIT | |
9603 | /* | |
9604 | * Take rq->lock to make 64-bit write safe on 32-bit platforms. | |
9605 | */ | |
05fa785c | 9606 | raw_spin_lock_irq(&cpu_rq(cpu)->lock); |
720f5498 | 9607 | *cpuusage = val; |
05fa785c | 9608 | raw_spin_unlock_irq(&cpu_rq(cpu)->lock); |
720f5498 KC |
9609 | #else |
9610 | *cpuusage = val; | |
9611 | #endif | |
9612 | } | |
9613 | ||
d842de87 | 9614 | /* return total cpu usage (in nanoseconds) of a group */ |
32cd756a | 9615 | static u64 cpuusage_read(struct cgroup *cgrp, struct cftype *cft) |
d842de87 | 9616 | { |
32cd756a | 9617 | struct cpuacct *ca = cgroup_ca(cgrp); |
d842de87 SV |
9618 | u64 totalcpuusage = 0; |
9619 | int i; | |
9620 | ||
720f5498 KC |
9621 | for_each_present_cpu(i) |
9622 | totalcpuusage += cpuacct_cpuusage_read(ca, i); | |
d842de87 SV |
9623 | |
9624 | return totalcpuusage; | |
9625 | } | |
9626 | ||
0297b803 DG |
9627 | static int cpuusage_write(struct cgroup *cgrp, struct cftype *cftype, |
9628 | u64 reset) | |
9629 | { | |
9630 | struct cpuacct *ca = cgroup_ca(cgrp); | |
9631 | int err = 0; | |
9632 | int i; | |
9633 | ||
9634 | if (reset) { | |
9635 | err = -EINVAL; | |
9636 | goto out; | |
9637 | } | |
9638 | ||
720f5498 KC |
9639 | for_each_present_cpu(i) |
9640 | cpuacct_cpuusage_write(ca, i, 0); | |
0297b803 | 9641 | |
0297b803 DG |
9642 | out: |
9643 | return err; | |
9644 | } | |
9645 | ||
e9515c3c KC |
9646 | static int cpuacct_percpu_seq_read(struct cgroup *cgroup, struct cftype *cft, |
9647 | struct seq_file *m) | |
9648 | { | |
9649 | struct cpuacct *ca = cgroup_ca(cgroup); | |
9650 | u64 percpu; | |
9651 | int i; | |
9652 | ||
9653 | for_each_present_cpu(i) { | |
9654 | percpu = cpuacct_cpuusage_read(ca, i); | |
9655 | seq_printf(m, "%llu ", (unsigned long long) percpu); | |
9656 | } | |
9657 | seq_printf(m, "\n"); | |
9658 | return 0; | |
9659 | } | |
9660 | ||
ef12fefa BR |
9661 | static const char *cpuacct_stat_desc[] = { |
9662 | [CPUACCT_STAT_USER] = "user", | |
9663 | [CPUACCT_STAT_SYSTEM] = "system", | |
9664 | }; | |
9665 | ||
9666 | static int cpuacct_stats_show(struct cgroup *cgrp, struct cftype *cft, | |
9667 | struct cgroup_map_cb *cb) | |
9668 | { | |
9669 | struct cpuacct *ca = cgroup_ca(cgrp); | |
9670 | int i; | |
9671 | ||
9672 | for (i = 0; i < CPUACCT_STAT_NSTATS; i++) { | |
9673 | s64 val = percpu_counter_read(&ca->cpustat[i]); | |
9674 | val = cputime64_to_clock_t(val); | |
9675 | cb->fill(cb, cpuacct_stat_desc[i], val); | |
9676 | } | |
9677 | return 0; | |
9678 | } | |
9679 | ||
d842de87 SV |
9680 | static struct cftype files[] = { |
9681 | { | |
9682 | .name = "usage", | |
f4c753b7 PM |
9683 | .read_u64 = cpuusage_read, |
9684 | .write_u64 = cpuusage_write, | |
d842de87 | 9685 | }, |
e9515c3c KC |
9686 | { |
9687 | .name = "usage_percpu", | |
9688 | .read_seq_string = cpuacct_percpu_seq_read, | |
9689 | }, | |
ef12fefa BR |
9690 | { |
9691 | .name = "stat", | |
9692 | .read_map = cpuacct_stats_show, | |
9693 | }, | |
d842de87 SV |
9694 | }; |
9695 | ||
32cd756a | 9696 | static int cpuacct_populate(struct cgroup_subsys *ss, struct cgroup *cgrp) |
d842de87 | 9697 | { |
32cd756a | 9698 | return cgroup_add_files(cgrp, ss, files, ARRAY_SIZE(files)); |
d842de87 SV |
9699 | } |
9700 | ||
9701 | /* | |
9702 | * charge this task's execution time to its accounting group. | |
9703 | * | |
9704 | * called with rq->lock held. | |
9705 | */ | |
9706 | static void cpuacct_charge(struct task_struct *tsk, u64 cputime) | |
9707 | { | |
9708 | struct cpuacct *ca; | |
934352f2 | 9709 | int cpu; |
d842de87 | 9710 | |
c40c6f85 | 9711 | if (unlikely(!cpuacct_subsys.active)) |
d842de87 SV |
9712 | return; |
9713 | ||
934352f2 | 9714 | cpu = task_cpu(tsk); |
a18b83b7 BR |
9715 | |
9716 | rcu_read_lock(); | |
9717 | ||
d842de87 | 9718 | ca = task_ca(tsk); |
d842de87 | 9719 | |
934352f2 | 9720 | for (; ca; ca = ca->parent) { |
b36128c8 | 9721 | u64 *cpuusage = per_cpu_ptr(ca->cpuusage, cpu); |
d842de87 SV |
9722 | *cpuusage += cputime; |
9723 | } | |
a18b83b7 BR |
9724 | |
9725 | rcu_read_unlock(); | |
d842de87 SV |
9726 | } |
9727 | ||
fa535a77 AB |
9728 | /* |
9729 | * When CONFIG_VIRT_CPU_ACCOUNTING is enabled one jiffy can be very large | |
9730 | * in cputime_t units. As a result, cpuacct_update_stats calls | |
9731 | * percpu_counter_add with values large enough to always overflow the | |
9732 | * per cpu batch limit causing bad SMP scalability. | |
9733 | * | |
9734 | * To fix this we scale percpu_counter_batch by cputime_one_jiffy so we | |
9735 | * batch the same amount of time with CONFIG_VIRT_CPU_ACCOUNTING disabled | |
9736 | * and enabled. We cap it at INT_MAX which is the largest allowed batch value. | |
9737 | */ | |
9738 | #ifdef CONFIG_SMP | |
9739 | #define CPUACCT_BATCH \ | |
9740 | min_t(long, percpu_counter_batch * cputime_one_jiffy, INT_MAX) | |
9741 | #else | |
9742 | #define CPUACCT_BATCH 0 | |
9743 | #endif | |
9744 | ||
ef12fefa BR |
9745 | /* |
9746 | * Charge the system/user time to the task's accounting group. | |
9747 | */ | |
9748 | static void cpuacct_update_stats(struct task_struct *tsk, | |
9749 | enum cpuacct_stat_index idx, cputime_t val) | |
9750 | { | |
9751 | struct cpuacct *ca; | |
fa535a77 | 9752 | int batch = CPUACCT_BATCH; |
ef12fefa BR |
9753 | |
9754 | if (unlikely(!cpuacct_subsys.active)) | |
9755 | return; | |
9756 | ||
9757 | rcu_read_lock(); | |
9758 | ca = task_ca(tsk); | |
9759 | ||
9760 | do { | |
64861634 MS |
9761 | __percpu_counter_add(&ca->cpustat[idx], |
9762 | (__force s64) val, batch); | |
ef12fefa BR |
9763 | ca = ca->parent; |
9764 | } while (ca); | |
9765 | rcu_read_unlock(); | |
9766 | } | |
9767 | ||
d842de87 SV |
9768 | struct cgroup_subsys cpuacct_subsys = { |
9769 | .name = "cpuacct", | |
9770 | .create = cpuacct_create, | |
9771 | .destroy = cpuacct_destroy, | |
9772 | .populate = cpuacct_populate, | |
9773 | .subsys_id = cpuacct_subsys_id, | |
9774 | }; | |
9775 | #endif /* CONFIG_CGROUP_CPUACCT */ |