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> |
1da177e4 LT |
31 | |
32 | /* | |
f756d5e2 NL |
33 | * The per-CPU workqueue (if single thread, we always use the first |
34 | * possible cpu). | |
1da177e4 LT |
35 | * |
36 | * The sequence counters are for flush_scheduled_work(). It wants to wait | |
37 | * until until all currently-scheduled works are completed, but it doesn't | |
38 | * want to be livelocked by new, incoming ones. So it waits until | |
39 | * remove_sequence is >= the insert_sequence which pertained when | |
40 | * flush_scheduled_work() was called. | |
41 | */ | |
42 | struct cpu_workqueue_struct { | |
43 | ||
44 | spinlock_t lock; | |
45 | ||
46 | long remove_sequence; /* Least-recently added (next to run) */ | |
47 | long insert_sequence; /* Next to add */ | |
48 | ||
49 | struct list_head worklist; | |
50 | wait_queue_head_t more_work; | |
51 | wait_queue_head_t work_done; | |
52 | ||
53 | struct workqueue_struct *wq; | |
54 | task_t *thread; | |
55 | ||
56 | int run_depth; /* Detect run_workqueue() recursion depth */ | |
57 | } ____cacheline_aligned; | |
58 | ||
59 | /* | |
60 | * The externally visible workqueue abstraction is an array of | |
61 | * per-CPU workqueues: | |
62 | */ | |
63 | struct workqueue_struct { | |
89ada679 | 64 | struct cpu_workqueue_struct *cpu_wq; |
1da177e4 LT |
65 | const char *name; |
66 | struct list_head list; /* Empty if single thread */ | |
67 | }; | |
68 | ||
69 | /* All the per-cpu workqueues on the system, for hotplug cpu to add/remove | |
70 | threads to each one as cpus come/go. */ | |
71 | static DEFINE_SPINLOCK(workqueue_lock); | |
72 | static LIST_HEAD(workqueues); | |
73 | ||
f756d5e2 NL |
74 | static int singlethread_cpu; |
75 | ||
1da177e4 LT |
76 | /* If it's single threaded, it isn't in the list of workqueues. */ |
77 | static inline int is_single_threaded(struct workqueue_struct *wq) | |
78 | { | |
79 | return list_empty(&wq->list); | |
80 | } | |
81 | ||
82 | /* Preempt must be disabled. */ | |
83 | static void __queue_work(struct cpu_workqueue_struct *cwq, | |
84 | struct work_struct *work) | |
85 | { | |
86 | unsigned long flags; | |
87 | ||
88 | spin_lock_irqsave(&cwq->lock, flags); | |
89 | work->wq_data = cwq; | |
90 | list_add_tail(&work->entry, &cwq->worklist); | |
91 | cwq->insert_sequence++; | |
92 | wake_up(&cwq->more_work); | |
93 | spin_unlock_irqrestore(&cwq->lock, flags); | |
94 | } | |
95 | ||
96 | /* | |
97 | * Queue work on a workqueue. Return non-zero if it was successfully | |
98 | * added. | |
99 | * | |
100 | * We queue the work to the CPU it was submitted, but there is no | |
101 | * guarantee that it will be processed by that CPU. | |
102 | */ | |
103 | int fastcall queue_work(struct workqueue_struct *wq, struct work_struct *work) | |
104 | { | |
105 | int ret = 0, cpu = get_cpu(); | |
106 | ||
107 | if (!test_and_set_bit(0, &work->pending)) { | |
108 | if (unlikely(is_single_threaded(wq))) | |
f756d5e2 | 109 | cpu = singlethread_cpu; |
1da177e4 | 110 | BUG_ON(!list_empty(&work->entry)); |
89ada679 | 111 | __queue_work(per_cpu_ptr(wq->cpu_wq, cpu), work); |
1da177e4 LT |
112 | ret = 1; |
113 | } | |
114 | put_cpu(); | |
115 | return ret; | |
116 | } | |
117 | ||
118 | static void delayed_work_timer_fn(unsigned long __data) | |
119 | { | |
120 | struct work_struct *work = (struct work_struct *)__data; | |
121 | struct workqueue_struct *wq = work->wq_data; | |
122 | int cpu = smp_processor_id(); | |
123 | ||
124 | if (unlikely(is_single_threaded(wq))) | |
f756d5e2 | 125 | cpu = singlethread_cpu; |
1da177e4 | 126 | |
89ada679 | 127 | __queue_work(per_cpu_ptr(wq->cpu_wq, cpu), work); |
1da177e4 LT |
128 | } |
129 | ||
130 | int fastcall queue_delayed_work(struct workqueue_struct *wq, | |
131 | struct work_struct *work, unsigned long delay) | |
132 | { | |
133 | int ret = 0; | |
134 | struct timer_list *timer = &work->timer; | |
135 | ||
136 | if (!test_and_set_bit(0, &work->pending)) { | |
137 | BUG_ON(timer_pending(timer)); | |
138 | BUG_ON(!list_empty(&work->entry)); | |
139 | ||
140 | /* This stores wq for the moment, for the timer_fn */ | |
141 | work->wq_data = wq; | |
142 | timer->expires = jiffies + delay; | |
143 | timer->data = (unsigned long)work; | |
144 | timer->function = delayed_work_timer_fn; | |
145 | add_timer(timer); | |
146 | ret = 1; | |
147 | } | |
148 | return ret; | |
149 | } | |
150 | ||
858119e1 | 151 | static void run_workqueue(struct cpu_workqueue_struct *cwq) |
1da177e4 LT |
152 | { |
153 | unsigned long flags; | |
154 | ||
155 | /* | |
156 | * Keep taking off work from the queue until | |
157 | * done. | |
158 | */ | |
159 | spin_lock_irqsave(&cwq->lock, flags); | |
160 | cwq->run_depth++; | |
161 | if (cwq->run_depth > 3) { | |
162 | /* morton gets to eat his hat */ | |
163 | printk("%s: recursion depth exceeded: %d\n", | |
164 | __FUNCTION__, cwq->run_depth); | |
165 | dump_stack(); | |
166 | } | |
167 | while (!list_empty(&cwq->worklist)) { | |
168 | struct work_struct *work = list_entry(cwq->worklist.next, | |
169 | struct work_struct, entry); | |
170 | void (*f) (void *) = work->func; | |
171 | void *data = work->data; | |
172 | ||
173 | list_del_init(cwq->worklist.next); | |
174 | spin_unlock_irqrestore(&cwq->lock, flags); | |
175 | ||
176 | BUG_ON(work->wq_data != cwq); | |
177 | clear_bit(0, &work->pending); | |
178 | f(data); | |
179 | ||
180 | spin_lock_irqsave(&cwq->lock, flags); | |
181 | cwq->remove_sequence++; | |
182 | wake_up(&cwq->work_done); | |
183 | } | |
184 | cwq->run_depth--; | |
185 | spin_unlock_irqrestore(&cwq->lock, flags); | |
186 | } | |
187 | ||
188 | static int worker_thread(void *__cwq) | |
189 | { | |
190 | struct cpu_workqueue_struct *cwq = __cwq; | |
191 | DECLARE_WAITQUEUE(wait, current); | |
192 | struct k_sigaction sa; | |
193 | sigset_t blocked; | |
194 | ||
195 | current->flags |= PF_NOFREEZE; | |
196 | ||
197 | set_user_nice(current, -5); | |
198 | ||
199 | /* Block and flush all signals */ | |
200 | sigfillset(&blocked); | |
201 | sigprocmask(SIG_BLOCK, &blocked, NULL); | |
202 | flush_signals(current); | |
203 | ||
204 | /* SIG_IGN makes children autoreap: see do_notify_parent(). */ | |
205 | sa.sa.sa_handler = SIG_IGN; | |
206 | sa.sa.sa_flags = 0; | |
207 | siginitset(&sa.sa.sa_mask, sigmask(SIGCHLD)); | |
208 | do_sigaction(SIGCHLD, &sa, (struct k_sigaction *)0); | |
209 | ||
210 | set_current_state(TASK_INTERRUPTIBLE); | |
211 | while (!kthread_should_stop()) { | |
212 | add_wait_queue(&cwq->more_work, &wait); | |
213 | if (list_empty(&cwq->worklist)) | |
214 | schedule(); | |
215 | else | |
216 | __set_current_state(TASK_RUNNING); | |
217 | remove_wait_queue(&cwq->more_work, &wait); | |
218 | ||
219 | if (!list_empty(&cwq->worklist)) | |
220 | run_workqueue(cwq); | |
221 | set_current_state(TASK_INTERRUPTIBLE); | |
222 | } | |
223 | __set_current_state(TASK_RUNNING); | |
224 | return 0; | |
225 | } | |
226 | ||
227 | static void flush_cpu_workqueue(struct cpu_workqueue_struct *cwq) | |
228 | { | |
229 | if (cwq->thread == current) { | |
230 | /* | |
231 | * Probably keventd trying to flush its own queue. So simply run | |
232 | * it by hand rather than deadlocking. | |
233 | */ | |
234 | run_workqueue(cwq); | |
235 | } else { | |
236 | DEFINE_WAIT(wait); | |
237 | long sequence_needed; | |
238 | ||
239 | spin_lock_irq(&cwq->lock); | |
240 | sequence_needed = cwq->insert_sequence; | |
241 | ||
242 | while (sequence_needed - cwq->remove_sequence > 0) { | |
243 | prepare_to_wait(&cwq->work_done, &wait, | |
244 | TASK_UNINTERRUPTIBLE); | |
245 | spin_unlock_irq(&cwq->lock); | |
246 | schedule(); | |
247 | spin_lock_irq(&cwq->lock); | |
248 | } | |
249 | finish_wait(&cwq->work_done, &wait); | |
250 | spin_unlock_irq(&cwq->lock); | |
251 | } | |
252 | } | |
253 | ||
254 | /* | |
255 | * flush_workqueue - ensure that any scheduled work has run to completion. | |
256 | * | |
257 | * Forces execution of the workqueue and blocks until its completion. | |
258 | * This is typically used in driver shutdown handlers. | |
259 | * | |
260 | * This function will sample each workqueue's current insert_sequence number and | |
261 | * will sleep until the head sequence is greater than or equal to that. This | |
262 | * means that we sleep until all works which were queued on entry have been | |
263 | * handled, but we are not livelocked by new incoming ones. | |
264 | * | |
265 | * This function used to run the workqueues itself. Now we just wait for the | |
266 | * helper threads to do it. | |
267 | */ | |
268 | void fastcall flush_workqueue(struct workqueue_struct *wq) | |
269 | { | |
270 | might_sleep(); | |
271 | ||
272 | if (is_single_threaded(wq)) { | |
bce61dd4 | 273 | /* Always use first cpu's area. */ |
f756d5e2 | 274 | flush_cpu_workqueue(per_cpu_ptr(wq->cpu_wq, singlethread_cpu)); |
1da177e4 LT |
275 | } else { |
276 | int cpu; | |
277 | ||
278 | lock_cpu_hotplug(); | |
279 | for_each_online_cpu(cpu) | |
89ada679 | 280 | flush_cpu_workqueue(per_cpu_ptr(wq->cpu_wq, cpu)); |
1da177e4 LT |
281 | unlock_cpu_hotplug(); |
282 | } | |
283 | } | |
284 | ||
285 | static struct task_struct *create_workqueue_thread(struct workqueue_struct *wq, | |
286 | int cpu) | |
287 | { | |
89ada679 | 288 | struct cpu_workqueue_struct *cwq = per_cpu_ptr(wq->cpu_wq, cpu); |
1da177e4 LT |
289 | struct task_struct *p; |
290 | ||
291 | spin_lock_init(&cwq->lock); | |
292 | cwq->wq = wq; | |
293 | cwq->thread = NULL; | |
294 | cwq->insert_sequence = 0; | |
295 | cwq->remove_sequence = 0; | |
296 | INIT_LIST_HEAD(&cwq->worklist); | |
297 | init_waitqueue_head(&cwq->more_work); | |
298 | init_waitqueue_head(&cwq->work_done); | |
299 | ||
300 | if (is_single_threaded(wq)) | |
301 | p = kthread_create(worker_thread, cwq, "%s", wq->name); | |
302 | else | |
303 | p = kthread_create(worker_thread, cwq, "%s/%d", wq->name, cpu); | |
304 | if (IS_ERR(p)) | |
305 | return NULL; | |
306 | cwq->thread = p; | |
307 | return p; | |
308 | } | |
309 | ||
310 | struct workqueue_struct *__create_workqueue(const char *name, | |
311 | int singlethread) | |
312 | { | |
313 | int cpu, destroy = 0; | |
314 | struct workqueue_struct *wq; | |
315 | struct task_struct *p; | |
316 | ||
dd392710 | 317 | wq = kzalloc(sizeof(*wq), GFP_KERNEL); |
1da177e4 LT |
318 | if (!wq) |
319 | return NULL; | |
1da177e4 | 320 | |
89ada679 | 321 | wq->cpu_wq = alloc_percpu(struct cpu_workqueue_struct); |
676121fc BC |
322 | if (!wq->cpu_wq) { |
323 | kfree(wq); | |
324 | return NULL; | |
325 | } | |
326 | ||
1da177e4 LT |
327 | wq->name = name; |
328 | /* We don't need the distraction of CPUs appearing and vanishing. */ | |
329 | lock_cpu_hotplug(); | |
330 | if (singlethread) { | |
331 | INIT_LIST_HEAD(&wq->list); | |
f756d5e2 | 332 | p = create_workqueue_thread(wq, singlethread_cpu); |
1da177e4 LT |
333 | if (!p) |
334 | destroy = 1; | |
335 | else | |
336 | wake_up_process(p); | |
337 | } else { | |
338 | spin_lock(&workqueue_lock); | |
339 | list_add(&wq->list, &workqueues); | |
340 | spin_unlock(&workqueue_lock); | |
341 | for_each_online_cpu(cpu) { | |
342 | p = create_workqueue_thread(wq, cpu); | |
343 | if (p) { | |
344 | kthread_bind(p, cpu); | |
345 | wake_up_process(p); | |
346 | } else | |
347 | destroy = 1; | |
348 | } | |
349 | } | |
350 | unlock_cpu_hotplug(); | |
351 | ||
352 | /* | |
353 | * Was there any error during startup? If yes then clean up: | |
354 | */ | |
355 | if (destroy) { | |
356 | destroy_workqueue(wq); | |
357 | wq = NULL; | |
358 | } | |
359 | return wq; | |
360 | } | |
361 | ||
362 | static void cleanup_workqueue_thread(struct workqueue_struct *wq, int cpu) | |
363 | { | |
364 | struct cpu_workqueue_struct *cwq; | |
365 | unsigned long flags; | |
366 | struct task_struct *p; | |
367 | ||
89ada679 | 368 | cwq = per_cpu_ptr(wq->cpu_wq, cpu); |
1da177e4 LT |
369 | spin_lock_irqsave(&cwq->lock, flags); |
370 | p = cwq->thread; | |
371 | cwq->thread = NULL; | |
372 | spin_unlock_irqrestore(&cwq->lock, flags); | |
373 | if (p) | |
374 | kthread_stop(p); | |
375 | } | |
376 | ||
377 | void destroy_workqueue(struct workqueue_struct *wq) | |
378 | { | |
379 | int cpu; | |
380 | ||
381 | flush_workqueue(wq); | |
382 | ||
383 | /* We don't need the distraction of CPUs appearing and vanishing. */ | |
384 | lock_cpu_hotplug(); | |
385 | if (is_single_threaded(wq)) | |
f756d5e2 | 386 | cleanup_workqueue_thread(wq, singlethread_cpu); |
1da177e4 LT |
387 | else { |
388 | for_each_online_cpu(cpu) | |
389 | cleanup_workqueue_thread(wq, cpu); | |
390 | spin_lock(&workqueue_lock); | |
391 | list_del(&wq->list); | |
392 | spin_unlock(&workqueue_lock); | |
393 | } | |
394 | unlock_cpu_hotplug(); | |
89ada679 | 395 | free_percpu(wq->cpu_wq); |
1da177e4 LT |
396 | kfree(wq); |
397 | } | |
398 | ||
399 | static struct workqueue_struct *keventd_wq; | |
400 | ||
401 | int fastcall schedule_work(struct work_struct *work) | |
402 | { | |
403 | return queue_work(keventd_wq, work); | |
404 | } | |
405 | ||
406 | int fastcall schedule_delayed_work(struct work_struct *work, unsigned long delay) | |
407 | { | |
408 | return queue_delayed_work(keventd_wq, work, delay); | |
409 | } | |
410 | ||
411 | int schedule_delayed_work_on(int cpu, | |
412 | struct work_struct *work, unsigned long delay) | |
413 | { | |
414 | int ret = 0; | |
415 | struct timer_list *timer = &work->timer; | |
416 | ||
417 | if (!test_and_set_bit(0, &work->pending)) { | |
418 | BUG_ON(timer_pending(timer)); | |
419 | BUG_ON(!list_empty(&work->entry)); | |
420 | /* This stores keventd_wq for the moment, for the timer_fn */ | |
421 | work->wq_data = keventd_wq; | |
422 | timer->expires = jiffies + delay; | |
423 | timer->data = (unsigned long)work; | |
424 | timer->function = delayed_work_timer_fn; | |
425 | add_timer_on(timer, cpu); | |
426 | ret = 1; | |
427 | } | |
428 | return ret; | |
429 | } | |
430 | ||
b6136773 AM |
431 | /** |
432 | * schedule_on_each_cpu - call a function on each online CPU from keventd | |
433 | * @func: the function to call | |
434 | * @info: a pointer to pass to func() | |
435 | * | |
436 | * Returns zero on success. | |
437 | * Returns -ve errno on failure. | |
438 | * | |
439 | * Appears to be racy against CPU hotplug. | |
440 | * | |
441 | * schedule_on_each_cpu() is very slow. | |
442 | */ | |
443 | int schedule_on_each_cpu(void (*func)(void *info), void *info) | |
15316ba8 CL |
444 | { |
445 | int cpu; | |
b6136773 | 446 | struct work_struct *works; |
15316ba8 | 447 | |
b6136773 AM |
448 | works = alloc_percpu(struct work_struct); |
449 | if (!works) | |
15316ba8 | 450 | return -ENOMEM; |
b6136773 | 451 | |
15316ba8 | 452 | for_each_online_cpu(cpu) { |
b6136773 | 453 | INIT_WORK(per_cpu_ptr(works, cpu), func, info); |
15316ba8 | 454 | __queue_work(per_cpu_ptr(keventd_wq->cpu_wq, cpu), |
b6136773 | 455 | per_cpu_ptr(works, cpu)); |
15316ba8 CL |
456 | } |
457 | flush_workqueue(keventd_wq); | |
b6136773 | 458 | free_percpu(works); |
15316ba8 CL |
459 | return 0; |
460 | } | |
461 | ||
1da177e4 LT |
462 | void flush_scheduled_work(void) |
463 | { | |
464 | flush_workqueue(keventd_wq); | |
465 | } | |
466 | ||
467 | /** | |
468 | * cancel_rearming_delayed_workqueue - reliably kill off a delayed | |
469 | * work whose handler rearms the delayed work. | |
470 | * @wq: the controlling workqueue structure | |
471 | * @work: the delayed work struct | |
472 | */ | |
81ddef77 JB |
473 | void cancel_rearming_delayed_workqueue(struct workqueue_struct *wq, |
474 | struct work_struct *work) | |
1da177e4 LT |
475 | { |
476 | while (!cancel_delayed_work(work)) | |
477 | flush_workqueue(wq); | |
478 | } | |
81ddef77 | 479 | EXPORT_SYMBOL(cancel_rearming_delayed_workqueue); |
1da177e4 LT |
480 | |
481 | /** | |
482 | * cancel_rearming_delayed_work - reliably kill off a delayed keventd | |
483 | * work whose handler rearms the delayed work. | |
484 | * @work: the delayed work struct | |
485 | */ | |
486 | void cancel_rearming_delayed_work(struct work_struct *work) | |
487 | { | |
488 | cancel_rearming_delayed_workqueue(keventd_wq, work); | |
489 | } | |
490 | EXPORT_SYMBOL(cancel_rearming_delayed_work); | |
491 | ||
1fa44eca JB |
492 | /** |
493 | * execute_in_process_context - reliably execute the routine with user context | |
494 | * @fn: the function to execute | |
495 | * @data: data to pass to the function | |
496 | * @ew: guaranteed storage for the execute work structure (must | |
497 | * be available when the work executes) | |
498 | * | |
499 | * Executes the function immediately if process context is available, | |
500 | * otherwise schedules the function for delayed execution. | |
501 | * | |
502 | * Returns: 0 - function was executed | |
503 | * 1 - function was scheduled for execution | |
504 | */ | |
505 | int execute_in_process_context(void (*fn)(void *data), void *data, | |
506 | struct execute_work *ew) | |
507 | { | |
508 | if (!in_interrupt()) { | |
509 | fn(data); | |
510 | return 0; | |
511 | } | |
512 | ||
513 | INIT_WORK(&ew->work, fn, data); | |
514 | schedule_work(&ew->work); | |
515 | ||
516 | return 1; | |
517 | } | |
518 | EXPORT_SYMBOL_GPL(execute_in_process_context); | |
519 | ||
1da177e4 LT |
520 | int keventd_up(void) |
521 | { | |
522 | return keventd_wq != NULL; | |
523 | } | |
524 | ||
525 | int current_is_keventd(void) | |
526 | { | |
527 | struct cpu_workqueue_struct *cwq; | |
528 | int cpu = smp_processor_id(); /* preempt-safe: keventd is per-cpu */ | |
529 | int ret = 0; | |
530 | ||
531 | BUG_ON(!keventd_wq); | |
532 | ||
89ada679 | 533 | cwq = per_cpu_ptr(keventd_wq->cpu_wq, cpu); |
1da177e4 LT |
534 | if (current == cwq->thread) |
535 | ret = 1; | |
536 | ||
537 | return ret; | |
538 | ||
539 | } | |
540 | ||
541 | #ifdef CONFIG_HOTPLUG_CPU | |
542 | /* Take the work from this (downed) CPU. */ | |
543 | static void take_over_work(struct workqueue_struct *wq, unsigned int cpu) | |
544 | { | |
89ada679 | 545 | struct cpu_workqueue_struct *cwq = per_cpu_ptr(wq->cpu_wq, cpu); |
626ab0e6 | 546 | struct list_head list; |
1da177e4 LT |
547 | struct work_struct *work; |
548 | ||
549 | spin_lock_irq(&cwq->lock); | |
626ab0e6 | 550 | list_replace_init(&cwq->worklist, &list); |
1da177e4 LT |
551 | |
552 | while (!list_empty(&list)) { | |
553 | printk("Taking work for %s\n", wq->name); | |
554 | work = list_entry(list.next,struct work_struct,entry); | |
555 | list_del(&work->entry); | |
89ada679 | 556 | __queue_work(per_cpu_ptr(wq->cpu_wq, smp_processor_id()), work); |
1da177e4 LT |
557 | } |
558 | spin_unlock_irq(&cwq->lock); | |
559 | } | |
560 | ||
561 | /* We're holding the cpucontrol mutex here */ | |
83d722f7 | 562 | static int workqueue_cpu_callback(struct notifier_block *nfb, |
1da177e4 LT |
563 | unsigned long action, |
564 | void *hcpu) | |
565 | { | |
566 | unsigned int hotcpu = (unsigned long)hcpu; | |
567 | struct workqueue_struct *wq; | |
568 | ||
569 | switch (action) { | |
570 | case CPU_UP_PREPARE: | |
571 | /* Create a new workqueue thread for it. */ | |
572 | list_for_each_entry(wq, &workqueues, list) { | |
230649da | 573 | if (!create_workqueue_thread(wq, hotcpu)) { |
1da177e4 LT |
574 | printk("workqueue for %i failed\n", hotcpu); |
575 | return NOTIFY_BAD; | |
576 | } | |
577 | } | |
578 | break; | |
579 | ||
580 | case CPU_ONLINE: | |
581 | /* Kick off worker threads. */ | |
582 | list_for_each_entry(wq, &workqueues, list) { | |
89ada679 CL |
583 | struct cpu_workqueue_struct *cwq; |
584 | ||
585 | cwq = per_cpu_ptr(wq->cpu_wq, hotcpu); | |
586 | kthread_bind(cwq->thread, hotcpu); | |
587 | wake_up_process(cwq->thread); | |
1da177e4 LT |
588 | } |
589 | break; | |
590 | ||
591 | case CPU_UP_CANCELED: | |
592 | list_for_each_entry(wq, &workqueues, list) { | |
fc75cdfa HC |
593 | if (!per_cpu_ptr(wq->cpu_wq, hotcpu)->thread) |
594 | continue; | |
1da177e4 | 595 | /* Unbind so it can run. */ |
89ada679 | 596 | kthread_bind(per_cpu_ptr(wq->cpu_wq, hotcpu)->thread, |
a4c4af7c | 597 | any_online_cpu(cpu_online_map)); |
1da177e4 LT |
598 | cleanup_workqueue_thread(wq, hotcpu); |
599 | } | |
600 | break; | |
601 | ||
602 | case CPU_DEAD: | |
603 | list_for_each_entry(wq, &workqueues, list) | |
604 | cleanup_workqueue_thread(wq, hotcpu); | |
605 | list_for_each_entry(wq, &workqueues, list) | |
606 | take_over_work(wq, hotcpu); | |
607 | break; | |
608 | } | |
609 | ||
610 | return NOTIFY_OK; | |
611 | } | |
612 | #endif | |
613 | ||
614 | void init_workqueues(void) | |
615 | { | |
f756d5e2 | 616 | singlethread_cpu = first_cpu(cpu_possible_map); |
1da177e4 LT |
617 | hotcpu_notifier(workqueue_cpu_callback, 0); |
618 | keventd_wq = create_workqueue("events"); | |
619 | BUG_ON(!keventd_wq); | |
620 | } | |
621 | ||
622 | EXPORT_SYMBOL_GPL(__create_workqueue); | |
623 | EXPORT_SYMBOL_GPL(queue_work); | |
624 | EXPORT_SYMBOL_GPL(queue_delayed_work); | |
625 | EXPORT_SYMBOL_GPL(flush_workqueue); | |
626 | EXPORT_SYMBOL_GPL(destroy_workqueue); | |
627 | ||
628 | EXPORT_SYMBOL(schedule_work); | |
629 | EXPORT_SYMBOL(schedule_delayed_work); | |
630 | EXPORT_SYMBOL(schedule_delayed_work_on); | |
631 | EXPORT_SYMBOL(flush_scheduled_work); |