Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * linux/kernel/workqueue.c | |
3 | * | |
4 | * Generic mechanism for defining kernel helper threads for running | |
5 | * arbitrary tasks in process context. | |
6 | * | |
7 | * Started by Ingo Molnar, Copyright (C) 2002 | |
8 | * | |
9 | * Derived from the taskqueue/keventd code by: | |
10 | * | |
11 | * David Woodhouse <dwmw2@infradead.org> | |
12 | * Andrew Morton <andrewm@uow.edu.au> | |
13 | * Kai Petzke <wpp@marie.physik.tu-berlin.de> | |
14 | * Theodore Ts'o <tytso@mit.edu> | |
89ada679 CL |
15 | * |
16 | * Made to use alloc_percpu by Christoph Lameter <clameter@sgi.com>. | |
1da177e4 LT |
17 | */ |
18 | ||
19 | #include <linux/module.h> | |
20 | #include <linux/kernel.h> | |
21 | #include <linux/sched.h> | |
22 | #include <linux/init.h> | |
23 | #include <linux/signal.h> | |
24 | #include <linux/completion.h> | |
25 | #include <linux/workqueue.h> | |
26 | #include <linux/slab.h> | |
27 | #include <linux/cpu.h> | |
28 | #include <linux/notifier.h> | |
29 | #include <linux/kthread.h> | |
1fa44eca | 30 | #include <linux/hardirq.h> |
46934023 | 31 | #include <linux/mempolicy.h> |
341a5958 | 32 | #include <linux/freezer.h> |
1da177e4 LT |
33 | |
34 | /* | |
f756d5e2 NL |
35 | * The per-CPU workqueue (if single thread, we always use the first |
36 | * possible cpu). | |
1da177e4 LT |
37 | * |
38 | * The sequence counters are for flush_scheduled_work(). It wants to wait | |
9f5d785e | 39 | * until all currently-scheduled works are completed, but it doesn't |
1da177e4 LT |
40 | * want to be livelocked by new, incoming ones. So it waits until |
41 | * remove_sequence is >= the insert_sequence which pertained when | |
42 | * flush_scheduled_work() was called. | |
43 | */ | |
44 | struct cpu_workqueue_struct { | |
45 | ||
46 | spinlock_t lock; | |
47 | ||
48 | long remove_sequence; /* Least-recently added (next to run) */ | |
49 | long insert_sequence; /* Next to add */ | |
50 | ||
51 | struct list_head worklist; | |
52 | wait_queue_head_t more_work; | |
53 | wait_queue_head_t work_done; | |
54 | ||
55 | struct workqueue_struct *wq; | |
36c8b586 | 56 | struct task_struct *thread; |
1da177e4 LT |
57 | |
58 | int run_depth; /* Detect run_workqueue() recursion depth */ | |
341a5958 RW |
59 | |
60 | int freezeable; /* Freeze the thread during suspend */ | |
1da177e4 LT |
61 | } ____cacheline_aligned; |
62 | ||
63 | /* | |
64 | * The externally visible workqueue abstraction is an array of | |
65 | * per-CPU workqueues: | |
66 | */ | |
67 | struct workqueue_struct { | |
89ada679 | 68 | struct cpu_workqueue_struct *cpu_wq; |
1da177e4 LT |
69 | const char *name; |
70 | struct list_head list; /* Empty if single thread */ | |
71 | }; | |
72 | ||
73 | /* All the per-cpu workqueues on the system, for hotplug cpu to add/remove | |
74 | threads to each one as cpus come/go. */ | |
9b41ea72 | 75 | static DEFINE_MUTEX(workqueue_mutex); |
1da177e4 LT |
76 | static LIST_HEAD(workqueues); |
77 | ||
f756d5e2 NL |
78 | static int singlethread_cpu; |
79 | ||
1da177e4 LT |
80 | /* If it's single threaded, it isn't in the list of workqueues. */ |
81 | static inline int is_single_threaded(struct workqueue_struct *wq) | |
82 | { | |
83 | return list_empty(&wq->list); | |
84 | } | |
85 | ||
365970a1 DH |
86 | static inline void set_wq_data(struct work_struct *work, void *wq) |
87 | { | |
88 | unsigned long new, old, res; | |
89 | ||
90 | /* assume the pending flag is already set and that the task has already | |
91 | * been queued on this workqueue */ | |
92 | new = (unsigned long) wq | (1UL << WORK_STRUCT_PENDING); | |
93 | res = work->management; | |
94 | if (res != new) { | |
95 | do { | |
96 | old = res; | |
97 | new = (unsigned long) wq; | |
98 | new |= (old & WORK_STRUCT_FLAG_MASK); | |
99 | res = cmpxchg(&work->management, old, new); | |
100 | } while (res != old); | |
101 | } | |
102 | } | |
103 | ||
104 | static inline void *get_wq_data(struct work_struct *work) | |
105 | { | |
106 | return (void *) (work->management & WORK_STRUCT_WQ_DATA_MASK); | |
107 | } | |
108 | ||
1da177e4 LT |
109 | /* Preempt must be disabled. */ |
110 | static void __queue_work(struct cpu_workqueue_struct *cwq, | |
111 | struct work_struct *work) | |
112 | { | |
113 | unsigned long flags; | |
114 | ||
115 | spin_lock_irqsave(&cwq->lock, flags); | |
365970a1 | 116 | set_wq_data(work, cwq); |
1da177e4 LT |
117 | list_add_tail(&work->entry, &cwq->worklist); |
118 | cwq->insert_sequence++; | |
119 | wake_up(&cwq->more_work); | |
120 | spin_unlock_irqrestore(&cwq->lock, flags); | |
121 | } | |
122 | ||
0fcb78c2 REB |
123 | /** |
124 | * queue_work - queue work on a workqueue | |
125 | * @wq: workqueue to use | |
126 | * @work: work to queue | |
127 | * | |
057647fc | 128 | * Returns 0 if @work was already on a queue, non-zero otherwise. |
1da177e4 LT |
129 | * |
130 | * We queue the work to the CPU it was submitted, but there is no | |
131 | * guarantee that it will be processed by that CPU. | |
132 | */ | |
133 | int fastcall queue_work(struct workqueue_struct *wq, struct work_struct *work) | |
134 | { | |
135 | int ret = 0, cpu = get_cpu(); | |
136 | ||
365970a1 | 137 | if (!test_and_set_bit(WORK_STRUCT_PENDING, &work->management)) { |
1da177e4 | 138 | if (unlikely(is_single_threaded(wq))) |
f756d5e2 | 139 | cpu = singlethread_cpu; |
1da177e4 | 140 | BUG_ON(!list_empty(&work->entry)); |
89ada679 | 141 | __queue_work(per_cpu_ptr(wq->cpu_wq, cpu), work); |
1da177e4 LT |
142 | ret = 1; |
143 | } | |
144 | put_cpu(); | |
145 | return ret; | |
146 | } | |
ae90dd5d | 147 | EXPORT_SYMBOL_GPL(queue_work); |
1da177e4 LT |
148 | |
149 | static void delayed_work_timer_fn(unsigned long __data) | |
150 | { | |
52bad64d | 151 | struct delayed_work *dwork = (struct delayed_work *)__data; |
365970a1 | 152 | struct workqueue_struct *wq = get_wq_data(&dwork->work); |
1da177e4 LT |
153 | int cpu = smp_processor_id(); |
154 | ||
155 | if (unlikely(is_single_threaded(wq))) | |
f756d5e2 | 156 | cpu = singlethread_cpu; |
1da177e4 | 157 | |
52bad64d | 158 | __queue_work(per_cpu_ptr(wq->cpu_wq, cpu), &dwork->work); |
1da177e4 LT |
159 | } |
160 | ||
0fcb78c2 REB |
161 | /** |
162 | * queue_delayed_work - queue work on a workqueue after delay | |
163 | * @wq: workqueue to use | |
52bad64d | 164 | * @work: delayable work to queue |
0fcb78c2 REB |
165 | * @delay: number of jiffies to wait before queueing |
166 | * | |
057647fc | 167 | * Returns 0 if @work was already on a queue, non-zero otherwise. |
0fcb78c2 | 168 | */ |
1da177e4 | 169 | int fastcall queue_delayed_work(struct workqueue_struct *wq, |
52bad64d | 170 | struct delayed_work *dwork, unsigned long delay) |
1da177e4 LT |
171 | { |
172 | int ret = 0; | |
52bad64d DH |
173 | struct timer_list *timer = &dwork->timer; |
174 | struct work_struct *work = &dwork->work; | |
175 | ||
176 | if (delay == 0) | |
177 | return queue_work(wq, work); | |
1da177e4 | 178 | |
365970a1 | 179 | if (!test_and_set_bit(WORK_STRUCT_PENDING, &work->management)) { |
1da177e4 LT |
180 | BUG_ON(timer_pending(timer)); |
181 | BUG_ON(!list_empty(&work->entry)); | |
182 | ||
183 | /* This stores wq for the moment, for the timer_fn */ | |
365970a1 | 184 | set_wq_data(work, wq); |
1da177e4 | 185 | timer->expires = jiffies + delay; |
52bad64d | 186 | timer->data = (unsigned long)dwork; |
1da177e4 LT |
187 | timer->function = delayed_work_timer_fn; |
188 | add_timer(timer); | |
189 | ret = 1; | |
190 | } | |
191 | return ret; | |
192 | } | |
ae90dd5d | 193 | EXPORT_SYMBOL_GPL(queue_delayed_work); |
1da177e4 | 194 | |
0fcb78c2 REB |
195 | /** |
196 | * queue_delayed_work_on - queue work on specific CPU after delay | |
197 | * @cpu: CPU number to execute work on | |
198 | * @wq: workqueue to use | |
199 | * @work: work to queue | |
200 | * @delay: number of jiffies to wait before queueing | |
201 | * | |
057647fc | 202 | * Returns 0 if @work was already on a queue, non-zero otherwise. |
0fcb78c2 | 203 | */ |
7a6bc1cd | 204 | int queue_delayed_work_on(int cpu, struct workqueue_struct *wq, |
52bad64d | 205 | struct delayed_work *dwork, unsigned long delay) |
7a6bc1cd VP |
206 | { |
207 | int ret = 0; | |
52bad64d DH |
208 | struct timer_list *timer = &dwork->timer; |
209 | struct work_struct *work = &dwork->work; | |
7a6bc1cd | 210 | |
365970a1 | 211 | if (!test_and_set_bit(WORK_STRUCT_PENDING, &work->management)) { |
7a6bc1cd VP |
212 | BUG_ON(timer_pending(timer)); |
213 | BUG_ON(!list_empty(&work->entry)); | |
214 | ||
215 | /* This stores wq for the moment, for the timer_fn */ | |
365970a1 | 216 | set_wq_data(work, wq); |
7a6bc1cd | 217 | timer->expires = jiffies + delay; |
52bad64d | 218 | timer->data = (unsigned long)dwork; |
7a6bc1cd VP |
219 | timer->function = delayed_work_timer_fn; |
220 | add_timer_on(timer, cpu); | |
221 | ret = 1; | |
222 | } | |
223 | return ret; | |
224 | } | |
ae90dd5d | 225 | EXPORT_SYMBOL_GPL(queue_delayed_work_on); |
1da177e4 | 226 | |
858119e1 | 227 | static void run_workqueue(struct cpu_workqueue_struct *cwq) |
1da177e4 LT |
228 | { |
229 | unsigned long flags; | |
230 | ||
231 | /* | |
232 | * Keep taking off work from the queue until | |
233 | * done. | |
234 | */ | |
235 | spin_lock_irqsave(&cwq->lock, flags); | |
236 | cwq->run_depth++; | |
237 | if (cwq->run_depth > 3) { | |
238 | /* morton gets to eat his hat */ | |
239 | printk("%s: recursion depth exceeded: %d\n", | |
240 | __FUNCTION__, cwq->run_depth); | |
241 | dump_stack(); | |
242 | } | |
243 | while (!list_empty(&cwq->worklist)) { | |
244 | struct work_struct *work = list_entry(cwq->worklist.next, | |
245 | struct work_struct, entry); | |
6bb49e59 | 246 | work_func_t f = work->func; |
1da177e4 LT |
247 | |
248 | list_del_init(cwq->worklist.next); | |
249 | spin_unlock_irqrestore(&cwq->lock, flags); | |
250 | ||
365970a1 | 251 | BUG_ON(get_wq_data(work) != cwq); |
65f27f38 DH |
252 | if (!test_bit(WORK_STRUCT_NOAUTOREL, &work->management)) |
253 | work_release(work); | |
254 | f(work); | |
1da177e4 LT |
255 | |
256 | spin_lock_irqsave(&cwq->lock, flags); | |
257 | cwq->remove_sequence++; | |
258 | wake_up(&cwq->work_done); | |
259 | } | |
260 | cwq->run_depth--; | |
261 | spin_unlock_irqrestore(&cwq->lock, flags); | |
262 | } | |
263 | ||
264 | static int worker_thread(void *__cwq) | |
265 | { | |
266 | struct cpu_workqueue_struct *cwq = __cwq; | |
267 | DECLARE_WAITQUEUE(wait, current); | |
268 | struct k_sigaction sa; | |
269 | sigset_t blocked; | |
270 | ||
341a5958 RW |
271 | if (!cwq->freezeable) |
272 | current->flags |= PF_NOFREEZE; | |
1da177e4 LT |
273 | |
274 | set_user_nice(current, -5); | |
275 | ||
276 | /* Block and flush all signals */ | |
277 | sigfillset(&blocked); | |
278 | sigprocmask(SIG_BLOCK, &blocked, NULL); | |
279 | flush_signals(current); | |
280 | ||
46934023 CL |
281 | /* |
282 | * We inherited MPOL_INTERLEAVE from the booting kernel. | |
283 | * Set MPOL_DEFAULT to insure node local allocations. | |
284 | */ | |
285 | numa_default_policy(); | |
286 | ||
1da177e4 LT |
287 | /* SIG_IGN makes children autoreap: see do_notify_parent(). */ |
288 | sa.sa.sa_handler = SIG_IGN; | |
289 | sa.sa.sa_flags = 0; | |
290 | siginitset(&sa.sa.sa_mask, sigmask(SIGCHLD)); | |
291 | do_sigaction(SIGCHLD, &sa, (struct k_sigaction *)0); | |
292 | ||
293 | set_current_state(TASK_INTERRUPTIBLE); | |
294 | while (!kthread_should_stop()) { | |
341a5958 RW |
295 | if (cwq->freezeable) |
296 | try_to_freeze(); | |
297 | ||
1da177e4 LT |
298 | add_wait_queue(&cwq->more_work, &wait); |
299 | if (list_empty(&cwq->worklist)) | |
300 | schedule(); | |
301 | else | |
302 | __set_current_state(TASK_RUNNING); | |
303 | remove_wait_queue(&cwq->more_work, &wait); | |
304 | ||
305 | if (!list_empty(&cwq->worklist)) | |
306 | run_workqueue(cwq); | |
307 | set_current_state(TASK_INTERRUPTIBLE); | |
308 | } | |
309 | __set_current_state(TASK_RUNNING); | |
310 | return 0; | |
311 | } | |
312 | ||
313 | static void flush_cpu_workqueue(struct cpu_workqueue_struct *cwq) | |
314 | { | |
315 | if (cwq->thread == current) { | |
316 | /* | |
317 | * Probably keventd trying to flush its own queue. So simply run | |
318 | * it by hand rather than deadlocking. | |
319 | */ | |
320 | run_workqueue(cwq); | |
321 | } else { | |
322 | DEFINE_WAIT(wait); | |
323 | long sequence_needed; | |
324 | ||
325 | spin_lock_irq(&cwq->lock); | |
326 | sequence_needed = cwq->insert_sequence; | |
327 | ||
328 | while (sequence_needed - cwq->remove_sequence > 0) { | |
329 | prepare_to_wait(&cwq->work_done, &wait, | |
330 | TASK_UNINTERRUPTIBLE); | |
331 | spin_unlock_irq(&cwq->lock); | |
332 | schedule(); | |
333 | spin_lock_irq(&cwq->lock); | |
334 | } | |
335 | finish_wait(&cwq->work_done, &wait); | |
336 | spin_unlock_irq(&cwq->lock); | |
337 | } | |
338 | } | |
339 | ||
0fcb78c2 | 340 | /** |
1da177e4 | 341 | * flush_workqueue - ensure that any scheduled work has run to completion. |
0fcb78c2 | 342 | * @wq: workqueue to flush |
1da177e4 LT |
343 | * |
344 | * Forces execution of the workqueue and blocks until its completion. | |
345 | * This is typically used in driver shutdown handlers. | |
346 | * | |
347 | * This function will sample each workqueue's current insert_sequence number and | |
348 | * will sleep until the head sequence is greater than or equal to that. This | |
349 | * means that we sleep until all works which were queued on entry have been | |
350 | * handled, but we are not livelocked by new incoming ones. | |
351 | * | |
352 | * This function used to run the workqueues itself. Now we just wait for the | |
353 | * helper threads to do it. | |
354 | */ | |
355 | void fastcall flush_workqueue(struct workqueue_struct *wq) | |
356 | { | |
357 | might_sleep(); | |
358 | ||
359 | if (is_single_threaded(wq)) { | |
bce61dd4 | 360 | /* Always use first cpu's area. */ |
f756d5e2 | 361 | flush_cpu_workqueue(per_cpu_ptr(wq->cpu_wq, singlethread_cpu)); |
1da177e4 LT |
362 | } else { |
363 | int cpu; | |
364 | ||
9b41ea72 | 365 | mutex_lock(&workqueue_mutex); |
1da177e4 | 366 | for_each_online_cpu(cpu) |
89ada679 | 367 | flush_cpu_workqueue(per_cpu_ptr(wq->cpu_wq, cpu)); |
9b41ea72 | 368 | mutex_unlock(&workqueue_mutex); |
1da177e4 LT |
369 | } |
370 | } | |
ae90dd5d | 371 | EXPORT_SYMBOL_GPL(flush_workqueue); |
1da177e4 LT |
372 | |
373 | static struct task_struct *create_workqueue_thread(struct workqueue_struct *wq, | |
341a5958 | 374 | int cpu, int freezeable) |
1da177e4 | 375 | { |
89ada679 | 376 | struct cpu_workqueue_struct *cwq = per_cpu_ptr(wq->cpu_wq, cpu); |
1da177e4 LT |
377 | struct task_struct *p; |
378 | ||
379 | spin_lock_init(&cwq->lock); | |
380 | cwq->wq = wq; | |
381 | cwq->thread = NULL; | |
382 | cwq->insert_sequence = 0; | |
383 | cwq->remove_sequence = 0; | |
341a5958 | 384 | cwq->freezeable = freezeable; |
1da177e4 LT |
385 | INIT_LIST_HEAD(&cwq->worklist); |
386 | init_waitqueue_head(&cwq->more_work); | |
387 | init_waitqueue_head(&cwq->work_done); | |
388 | ||
389 | if (is_single_threaded(wq)) | |
390 | p = kthread_create(worker_thread, cwq, "%s", wq->name); | |
391 | else | |
392 | p = kthread_create(worker_thread, cwq, "%s/%d", wq->name, cpu); | |
393 | if (IS_ERR(p)) | |
394 | return NULL; | |
395 | cwq->thread = p; | |
396 | return p; | |
397 | } | |
398 | ||
399 | struct workqueue_struct *__create_workqueue(const char *name, | |
341a5958 | 400 | int singlethread, int freezeable) |
1da177e4 LT |
401 | { |
402 | int cpu, destroy = 0; | |
403 | struct workqueue_struct *wq; | |
404 | struct task_struct *p; | |
405 | ||
dd392710 | 406 | wq = kzalloc(sizeof(*wq), GFP_KERNEL); |
1da177e4 LT |
407 | if (!wq) |
408 | return NULL; | |
1da177e4 | 409 | |
89ada679 | 410 | wq->cpu_wq = alloc_percpu(struct cpu_workqueue_struct); |
676121fc BC |
411 | if (!wq->cpu_wq) { |
412 | kfree(wq); | |
413 | return NULL; | |
414 | } | |
415 | ||
1da177e4 | 416 | wq->name = name; |
9b41ea72 | 417 | mutex_lock(&workqueue_mutex); |
1da177e4 LT |
418 | if (singlethread) { |
419 | INIT_LIST_HEAD(&wq->list); | |
341a5958 | 420 | p = create_workqueue_thread(wq, singlethread_cpu, freezeable); |
1da177e4 LT |
421 | if (!p) |
422 | destroy = 1; | |
423 | else | |
424 | wake_up_process(p); | |
425 | } else { | |
1da177e4 | 426 | list_add(&wq->list, &workqueues); |
1da177e4 | 427 | for_each_online_cpu(cpu) { |
341a5958 | 428 | p = create_workqueue_thread(wq, cpu, freezeable); |
1da177e4 LT |
429 | if (p) { |
430 | kthread_bind(p, cpu); | |
431 | wake_up_process(p); | |
432 | } else | |
433 | destroy = 1; | |
434 | } | |
435 | } | |
9b41ea72 | 436 | mutex_unlock(&workqueue_mutex); |
1da177e4 LT |
437 | |
438 | /* | |
439 | * Was there any error during startup? If yes then clean up: | |
440 | */ | |
441 | if (destroy) { | |
442 | destroy_workqueue(wq); | |
443 | wq = NULL; | |
444 | } | |
445 | return wq; | |
446 | } | |
ae90dd5d | 447 | EXPORT_SYMBOL_GPL(__create_workqueue); |
1da177e4 LT |
448 | |
449 | static void cleanup_workqueue_thread(struct workqueue_struct *wq, int cpu) | |
450 | { | |
451 | struct cpu_workqueue_struct *cwq; | |
452 | unsigned long flags; | |
453 | struct task_struct *p; | |
454 | ||
89ada679 | 455 | cwq = per_cpu_ptr(wq->cpu_wq, cpu); |
1da177e4 LT |
456 | spin_lock_irqsave(&cwq->lock, flags); |
457 | p = cwq->thread; | |
458 | cwq->thread = NULL; | |
459 | spin_unlock_irqrestore(&cwq->lock, flags); | |
460 | if (p) | |
461 | kthread_stop(p); | |
462 | } | |
463 | ||
0fcb78c2 REB |
464 | /** |
465 | * destroy_workqueue - safely terminate a workqueue | |
466 | * @wq: target workqueue | |
467 | * | |
468 | * Safely destroy a workqueue. All work currently pending will be done first. | |
469 | */ | |
1da177e4 LT |
470 | void destroy_workqueue(struct workqueue_struct *wq) |
471 | { | |
472 | int cpu; | |
473 | ||
474 | flush_workqueue(wq); | |
475 | ||
476 | /* We don't need the distraction of CPUs appearing and vanishing. */ | |
9b41ea72 | 477 | mutex_lock(&workqueue_mutex); |
1da177e4 | 478 | if (is_single_threaded(wq)) |
f756d5e2 | 479 | cleanup_workqueue_thread(wq, singlethread_cpu); |
1da177e4 LT |
480 | else { |
481 | for_each_online_cpu(cpu) | |
482 | cleanup_workqueue_thread(wq, cpu); | |
1da177e4 | 483 | list_del(&wq->list); |
1da177e4 | 484 | } |
9b41ea72 | 485 | mutex_unlock(&workqueue_mutex); |
89ada679 | 486 | free_percpu(wq->cpu_wq); |
1da177e4 LT |
487 | kfree(wq); |
488 | } | |
ae90dd5d | 489 | EXPORT_SYMBOL_GPL(destroy_workqueue); |
1da177e4 LT |
490 | |
491 | static struct workqueue_struct *keventd_wq; | |
492 | ||
0fcb78c2 REB |
493 | /** |
494 | * schedule_work - put work task in global workqueue | |
495 | * @work: job to be done | |
496 | * | |
497 | * This puts a job in the kernel-global workqueue. | |
498 | */ | |
1da177e4 LT |
499 | int fastcall schedule_work(struct work_struct *work) |
500 | { | |
501 | return queue_work(keventd_wq, work); | |
502 | } | |
ae90dd5d | 503 | EXPORT_SYMBOL(schedule_work); |
1da177e4 | 504 | |
0fcb78c2 REB |
505 | /** |
506 | * schedule_delayed_work - put work task in global workqueue after delay | |
52bad64d DH |
507 | * @dwork: job to be done |
508 | * @delay: number of jiffies to wait or 0 for immediate execution | |
0fcb78c2 REB |
509 | * |
510 | * After waiting for a given time this puts a job in the kernel-global | |
511 | * workqueue. | |
512 | */ | |
52bad64d | 513 | int fastcall schedule_delayed_work(struct delayed_work *dwork, unsigned long delay) |
1da177e4 | 514 | { |
52bad64d | 515 | return queue_delayed_work(keventd_wq, dwork, delay); |
1da177e4 | 516 | } |
ae90dd5d | 517 | EXPORT_SYMBOL(schedule_delayed_work); |
1da177e4 | 518 | |
0fcb78c2 REB |
519 | /** |
520 | * schedule_delayed_work_on - queue work in global workqueue on CPU after delay | |
521 | * @cpu: cpu to use | |
52bad64d | 522 | * @dwork: job to be done |
0fcb78c2 REB |
523 | * @delay: number of jiffies to wait |
524 | * | |
525 | * After waiting for a given time this puts a job in the kernel-global | |
526 | * workqueue on the specified CPU. | |
527 | */ | |
1da177e4 | 528 | int schedule_delayed_work_on(int cpu, |
52bad64d | 529 | struct delayed_work *dwork, unsigned long delay) |
1da177e4 | 530 | { |
52bad64d | 531 | return queue_delayed_work_on(cpu, keventd_wq, dwork, delay); |
1da177e4 | 532 | } |
ae90dd5d | 533 | EXPORT_SYMBOL(schedule_delayed_work_on); |
1da177e4 | 534 | |
b6136773 AM |
535 | /** |
536 | * schedule_on_each_cpu - call a function on each online CPU from keventd | |
537 | * @func: the function to call | |
b6136773 AM |
538 | * |
539 | * Returns zero on success. | |
540 | * Returns -ve errno on failure. | |
541 | * | |
542 | * Appears to be racy against CPU hotplug. | |
543 | * | |
544 | * schedule_on_each_cpu() is very slow. | |
545 | */ | |
65f27f38 | 546 | int schedule_on_each_cpu(work_func_t func) |
15316ba8 CL |
547 | { |
548 | int cpu; | |
b6136773 | 549 | struct work_struct *works; |
15316ba8 | 550 | |
b6136773 AM |
551 | works = alloc_percpu(struct work_struct); |
552 | if (!works) | |
15316ba8 | 553 | return -ENOMEM; |
b6136773 | 554 | |
9b41ea72 | 555 | mutex_lock(&workqueue_mutex); |
15316ba8 | 556 | for_each_online_cpu(cpu) { |
65f27f38 | 557 | INIT_WORK(per_cpu_ptr(works, cpu), func); |
15316ba8 | 558 | __queue_work(per_cpu_ptr(keventd_wq->cpu_wq, cpu), |
b6136773 | 559 | per_cpu_ptr(works, cpu)); |
15316ba8 | 560 | } |
9b41ea72 | 561 | mutex_unlock(&workqueue_mutex); |
15316ba8 | 562 | flush_workqueue(keventd_wq); |
b6136773 | 563 | free_percpu(works); |
15316ba8 CL |
564 | return 0; |
565 | } | |
566 | ||
1da177e4 LT |
567 | void flush_scheduled_work(void) |
568 | { | |
569 | flush_workqueue(keventd_wq); | |
570 | } | |
ae90dd5d | 571 | EXPORT_SYMBOL(flush_scheduled_work); |
1da177e4 LT |
572 | |
573 | /** | |
574 | * cancel_rearming_delayed_workqueue - reliably kill off a delayed | |
575 | * work whose handler rearms the delayed work. | |
576 | * @wq: the controlling workqueue structure | |
52bad64d | 577 | * @dwork: the delayed work struct |
1da177e4 | 578 | */ |
81ddef77 | 579 | void cancel_rearming_delayed_workqueue(struct workqueue_struct *wq, |
52bad64d | 580 | struct delayed_work *dwork) |
1da177e4 | 581 | { |
52bad64d | 582 | while (!cancel_delayed_work(dwork)) |
1da177e4 LT |
583 | flush_workqueue(wq); |
584 | } | |
81ddef77 | 585 | EXPORT_SYMBOL(cancel_rearming_delayed_workqueue); |
1da177e4 LT |
586 | |
587 | /** | |
588 | * cancel_rearming_delayed_work - reliably kill off a delayed keventd | |
589 | * work whose handler rearms the delayed work. | |
52bad64d | 590 | * @dwork: the delayed work struct |
1da177e4 | 591 | */ |
52bad64d | 592 | void cancel_rearming_delayed_work(struct delayed_work *dwork) |
1da177e4 | 593 | { |
52bad64d | 594 | cancel_rearming_delayed_workqueue(keventd_wq, dwork); |
1da177e4 LT |
595 | } |
596 | EXPORT_SYMBOL(cancel_rearming_delayed_work); | |
597 | ||
1fa44eca JB |
598 | /** |
599 | * execute_in_process_context - reliably execute the routine with user context | |
600 | * @fn: the function to execute | |
1fa44eca JB |
601 | * @ew: guaranteed storage for the execute work structure (must |
602 | * be available when the work executes) | |
603 | * | |
604 | * Executes the function immediately if process context is available, | |
605 | * otherwise schedules the function for delayed execution. | |
606 | * | |
607 | * Returns: 0 - function was executed | |
608 | * 1 - function was scheduled for execution | |
609 | */ | |
65f27f38 | 610 | int execute_in_process_context(work_func_t fn, struct execute_work *ew) |
1fa44eca JB |
611 | { |
612 | if (!in_interrupt()) { | |
65f27f38 | 613 | fn(&ew->work); |
1fa44eca JB |
614 | return 0; |
615 | } | |
616 | ||
65f27f38 | 617 | INIT_WORK(&ew->work, fn); |
1fa44eca JB |
618 | schedule_work(&ew->work); |
619 | ||
620 | return 1; | |
621 | } | |
622 | EXPORT_SYMBOL_GPL(execute_in_process_context); | |
623 | ||
1da177e4 LT |
624 | int keventd_up(void) |
625 | { | |
626 | return keventd_wq != NULL; | |
627 | } | |
628 | ||
629 | int current_is_keventd(void) | |
630 | { | |
631 | struct cpu_workqueue_struct *cwq; | |
632 | int cpu = smp_processor_id(); /* preempt-safe: keventd is per-cpu */ | |
633 | int ret = 0; | |
634 | ||
635 | BUG_ON(!keventd_wq); | |
636 | ||
89ada679 | 637 | cwq = per_cpu_ptr(keventd_wq->cpu_wq, cpu); |
1da177e4 LT |
638 | if (current == cwq->thread) |
639 | ret = 1; | |
640 | ||
641 | return ret; | |
642 | ||
643 | } | |
644 | ||
645 | #ifdef CONFIG_HOTPLUG_CPU | |
646 | /* Take the work from this (downed) CPU. */ | |
647 | static void take_over_work(struct workqueue_struct *wq, unsigned int cpu) | |
648 | { | |
89ada679 | 649 | struct cpu_workqueue_struct *cwq = per_cpu_ptr(wq->cpu_wq, cpu); |
626ab0e6 | 650 | struct list_head list; |
1da177e4 LT |
651 | struct work_struct *work; |
652 | ||
653 | spin_lock_irq(&cwq->lock); | |
626ab0e6 | 654 | list_replace_init(&cwq->worklist, &list); |
1da177e4 LT |
655 | |
656 | while (!list_empty(&list)) { | |
657 | printk("Taking work for %s\n", wq->name); | |
658 | work = list_entry(list.next,struct work_struct,entry); | |
659 | list_del(&work->entry); | |
89ada679 | 660 | __queue_work(per_cpu_ptr(wq->cpu_wq, smp_processor_id()), work); |
1da177e4 LT |
661 | } |
662 | spin_unlock_irq(&cwq->lock); | |
663 | } | |
664 | ||
665 | /* We're holding the cpucontrol mutex here */ | |
9c7b216d | 666 | static int __devinit workqueue_cpu_callback(struct notifier_block *nfb, |
1da177e4 LT |
667 | unsigned long action, |
668 | void *hcpu) | |
669 | { | |
670 | unsigned int hotcpu = (unsigned long)hcpu; | |
671 | struct workqueue_struct *wq; | |
672 | ||
673 | switch (action) { | |
674 | case CPU_UP_PREPARE: | |
9b41ea72 | 675 | mutex_lock(&workqueue_mutex); |
1da177e4 LT |
676 | /* Create a new workqueue thread for it. */ |
677 | list_for_each_entry(wq, &workqueues, list) { | |
341a5958 | 678 | if (!create_workqueue_thread(wq, hotcpu, 0)) { |
1da177e4 LT |
679 | printk("workqueue for %i failed\n", hotcpu); |
680 | return NOTIFY_BAD; | |
681 | } | |
682 | } | |
683 | break; | |
684 | ||
685 | case CPU_ONLINE: | |
686 | /* Kick off worker threads. */ | |
687 | list_for_each_entry(wq, &workqueues, list) { | |
89ada679 CL |
688 | struct cpu_workqueue_struct *cwq; |
689 | ||
690 | cwq = per_cpu_ptr(wq->cpu_wq, hotcpu); | |
691 | kthread_bind(cwq->thread, hotcpu); | |
692 | wake_up_process(cwq->thread); | |
1da177e4 | 693 | } |
9b41ea72 | 694 | mutex_unlock(&workqueue_mutex); |
1da177e4 LT |
695 | break; |
696 | ||
697 | case CPU_UP_CANCELED: | |
698 | list_for_each_entry(wq, &workqueues, list) { | |
fc75cdfa HC |
699 | if (!per_cpu_ptr(wq->cpu_wq, hotcpu)->thread) |
700 | continue; | |
1da177e4 | 701 | /* Unbind so it can run. */ |
89ada679 | 702 | kthread_bind(per_cpu_ptr(wq->cpu_wq, hotcpu)->thread, |
a4c4af7c | 703 | any_online_cpu(cpu_online_map)); |
1da177e4 LT |
704 | cleanup_workqueue_thread(wq, hotcpu); |
705 | } | |
9b41ea72 AM |
706 | mutex_unlock(&workqueue_mutex); |
707 | break; | |
708 | ||
709 | case CPU_DOWN_PREPARE: | |
710 | mutex_lock(&workqueue_mutex); | |
711 | break; | |
712 | ||
713 | case CPU_DOWN_FAILED: | |
714 | mutex_unlock(&workqueue_mutex); | |
1da177e4 LT |
715 | break; |
716 | ||
717 | case CPU_DEAD: | |
718 | list_for_each_entry(wq, &workqueues, list) | |
719 | cleanup_workqueue_thread(wq, hotcpu); | |
720 | list_for_each_entry(wq, &workqueues, list) | |
721 | take_over_work(wq, hotcpu); | |
9b41ea72 | 722 | mutex_unlock(&workqueue_mutex); |
1da177e4 LT |
723 | break; |
724 | } | |
725 | ||
726 | return NOTIFY_OK; | |
727 | } | |
728 | #endif | |
729 | ||
730 | void init_workqueues(void) | |
731 | { | |
f756d5e2 | 732 | singlethread_cpu = first_cpu(cpu_possible_map); |
1da177e4 LT |
733 | hotcpu_notifier(workqueue_cpu_callback, 0); |
734 | keventd_wq = create_workqueue("events"); | |
735 | BUG_ON(!keventd_wq); | |
736 | } | |
737 |