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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> |
1da177e4 LT |
32 | |
33 | /* | |
f756d5e2 NL |
34 | * The per-CPU workqueue (if single thread, we always use the first |
35 | * possible cpu). | |
1da177e4 LT |
36 | * |
37 | * The sequence counters are for flush_scheduled_work(). It wants to wait | |
9f5d785e | 38 | * until all currently-scheduled works are completed, but it doesn't |
1da177e4 LT |
39 | * want to be livelocked by new, incoming ones. So it waits until |
40 | * remove_sequence is >= the insert_sequence which pertained when | |
41 | * flush_scheduled_work() was called. | |
42 | */ | |
43 | struct cpu_workqueue_struct { | |
44 | ||
45 | spinlock_t lock; | |
46 | ||
47 | long remove_sequence; /* Least-recently added (next to run) */ | |
48 | long insert_sequence; /* Next to add */ | |
49 | ||
50 | struct list_head worklist; | |
51 | wait_queue_head_t more_work; | |
52 | wait_queue_head_t work_done; | |
53 | ||
54 | struct workqueue_struct *wq; | |
36c8b586 | 55 | struct task_struct *thread; |
1da177e4 LT |
56 | |
57 | int run_depth; /* Detect run_workqueue() recursion depth */ | |
58 | } ____cacheline_aligned; | |
59 | ||
60 | /* | |
61 | * The externally visible workqueue abstraction is an array of | |
62 | * per-CPU workqueues: | |
63 | */ | |
64 | struct workqueue_struct { | |
89ada679 | 65 | struct cpu_workqueue_struct *cpu_wq; |
1da177e4 LT |
66 | const char *name; |
67 | struct list_head list; /* Empty if single thread */ | |
68 | }; | |
69 | ||
70 | /* All the per-cpu workqueues on the system, for hotplug cpu to add/remove | |
71 | threads to each one as cpus come/go. */ | |
9b41ea72 | 72 | static DEFINE_MUTEX(workqueue_mutex); |
1da177e4 LT |
73 | static LIST_HEAD(workqueues); |
74 | ||
f756d5e2 NL |
75 | static int singlethread_cpu; |
76 | ||
1da177e4 LT |
77 | /* If it's single threaded, it isn't in the list of workqueues. */ |
78 | static inline int is_single_threaded(struct workqueue_struct *wq) | |
79 | { | |
80 | return list_empty(&wq->list); | |
81 | } | |
82 | ||
365970a1 DH |
83 | static inline void set_wq_data(struct work_struct *work, void *wq) |
84 | { | |
85 | unsigned long new, old, res; | |
86 | ||
87 | /* assume the pending flag is already set and that the task has already | |
88 | * been queued on this workqueue */ | |
89 | new = (unsigned long) wq | (1UL << WORK_STRUCT_PENDING); | |
90 | res = work->management; | |
91 | if (res != new) { | |
92 | do { | |
93 | old = res; | |
94 | new = (unsigned long) wq; | |
95 | new |= (old & WORK_STRUCT_FLAG_MASK); | |
96 | res = cmpxchg(&work->management, old, new); | |
97 | } while (res != old); | |
98 | } | |
99 | } | |
100 | ||
101 | static inline void *get_wq_data(struct work_struct *work) | |
102 | { | |
103 | return (void *) (work->management & WORK_STRUCT_WQ_DATA_MASK); | |
104 | } | |
105 | ||
1da177e4 LT |
106 | /* Preempt must be disabled. */ |
107 | static void __queue_work(struct cpu_workqueue_struct *cwq, | |
108 | struct work_struct *work) | |
109 | { | |
110 | unsigned long flags; | |
111 | ||
112 | spin_lock_irqsave(&cwq->lock, flags); | |
365970a1 | 113 | set_wq_data(work, cwq); |
1da177e4 LT |
114 | list_add_tail(&work->entry, &cwq->worklist); |
115 | cwq->insert_sequence++; | |
116 | wake_up(&cwq->more_work); | |
117 | spin_unlock_irqrestore(&cwq->lock, flags); | |
118 | } | |
119 | ||
0fcb78c2 REB |
120 | /** |
121 | * queue_work - queue work on a workqueue | |
122 | * @wq: workqueue to use | |
123 | * @work: work to queue | |
124 | * | |
057647fc | 125 | * Returns 0 if @work was already on a queue, non-zero otherwise. |
1da177e4 LT |
126 | * |
127 | * We queue the work to the CPU it was submitted, but there is no | |
128 | * guarantee that it will be processed by that CPU. | |
129 | */ | |
130 | int fastcall queue_work(struct workqueue_struct *wq, struct work_struct *work) | |
131 | { | |
132 | int ret = 0, cpu = get_cpu(); | |
133 | ||
365970a1 | 134 | if (!test_and_set_bit(WORK_STRUCT_PENDING, &work->management)) { |
1da177e4 | 135 | if (unlikely(is_single_threaded(wq))) |
f756d5e2 | 136 | cpu = singlethread_cpu; |
1da177e4 | 137 | BUG_ON(!list_empty(&work->entry)); |
89ada679 | 138 | __queue_work(per_cpu_ptr(wq->cpu_wq, cpu), work); |
1da177e4 LT |
139 | ret = 1; |
140 | } | |
141 | put_cpu(); | |
142 | return ret; | |
143 | } | |
ae90dd5d | 144 | EXPORT_SYMBOL_GPL(queue_work); |
1da177e4 LT |
145 | |
146 | static void delayed_work_timer_fn(unsigned long __data) | |
147 | { | |
52bad64d | 148 | struct delayed_work *dwork = (struct delayed_work *)__data; |
365970a1 | 149 | struct workqueue_struct *wq = get_wq_data(&dwork->work); |
1da177e4 LT |
150 | int cpu = smp_processor_id(); |
151 | ||
152 | if (unlikely(is_single_threaded(wq))) | |
f756d5e2 | 153 | cpu = singlethread_cpu; |
1da177e4 | 154 | |
52bad64d | 155 | __queue_work(per_cpu_ptr(wq->cpu_wq, cpu), &dwork->work); |
1da177e4 LT |
156 | } |
157 | ||
0fcb78c2 REB |
158 | /** |
159 | * queue_delayed_work - queue work on a workqueue after delay | |
160 | * @wq: workqueue to use | |
52bad64d | 161 | * @work: delayable work to queue |
0fcb78c2 REB |
162 | * @delay: number of jiffies to wait before queueing |
163 | * | |
057647fc | 164 | * Returns 0 if @work was already on a queue, non-zero otherwise. |
0fcb78c2 | 165 | */ |
1da177e4 | 166 | int fastcall queue_delayed_work(struct workqueue_struct *wq, |
52bad64d | 167 | struct delayed_work *dwork, unsigned long delay) |
1da177e4 LT |
168 | { |
169 | int ret = 0; | |
52bad64d DH |
170 | struct timer_list *timer = &dwork->timer; |
171 | struct work_struct *work = &dwork->work; | |
172 | ||
173 | if (delay == 0) | |
174 | return queue_work(wq, work); | |
1da177e4 | 175 | |
365970a1 | 176 | if (!test_and_set_bit(WORK_STRUCT_PENDING, &work->management)) { |
1da177e4 LT |
177 | BUG_ON(timer_pending(timer)); |
178 | BUG_ON(!list_empty(&work->entry)); | |
179 | ||
180 | /* This stores wq for the moment, for the timer_fn */ | |
365970a1 | 181 | set_wq_data(work, wq); |
1da177e4 | 182 | timer->expires = jiffies + delay; |
52bad64d | 183 | timer->data = (unsigned long)dwork; |
1da177e4 LT |
184 | timer->function = delayed_work_timer_fn; |
185 | add_timer(timer); | |
186 | ret = 1; | |
187 | } | |
188 | return ret; | |
189 | } | |
ae90dd5d | 190 | EXPORT_SYMBOL_GPL(queue_delayed_work); |
1da177e4 | 191 | |
0fcb78c2 REB |
192 | /** |
193 | * queue_delayed_work_on - queue work on specific CPU after delay | |
194 | * @cpu: CPU number to execute work on | |
195 | * @wq: workqueue to use | |
196 | * @work: work to queue | |
197 | * @delay: number of jiffies to wait before queueing | |
198 | * | |
057647fc | 199 | * Returns 0 if @work was already on a queue, non-zero otherwise. |
0fcb78c2 | 200 | */ |
7a6bc1cd | 201 | int queue_delayed_work_on(int cpu, struct workqueue_struct *wq, |
52bad64d | 202 | struct delayed_work *dwork, unsigned long delay) |
7a6bc1cd VP |
203 | { |
204 | int ret = 0; | |
52bad64d DH |
205 | struct timer_list *timer = &dwork->timer; |
206 | struct work_struct *work = &dwork->work; | |
7a6bc1cd | 207 | |
365970a1 | 208 | if (!test_and_set_bit(WORK_STRUCT_PENDING, &work->management)) { |
7a6bc1cd VP |
209 | BUG_ON(timer_pending(timer)); |
210 | BUG_ON(!list_empty(&work->entry)); | |
211 | ||
212 | /* This stores wq for the moment, for the timer_fn */ | |
365970a1 | 213 | set_wq_data(work, wq); |
7a6bc1cd | 214 | timer->expires = jiffies + delay; |
52bad64d | 215 | timer->data = (unsigned long)dwork; |
7a6bc1cd VP |
216 | timer->function = delayed_work_timer_fn; |
217 | add_timer_on(timer, cpu); | |
218 | ret = 1; | |
219 | } | |
220 | return ret; | |
221 | } | |
ae90dd5d | 222 | EXPORT_SYMBOL_GPL(queue_delayed_work_on); |
1da177e4 | 223 | |
858119e1 | 224 | static void run_workqueue(struct cpu_workqueue_struct *cwq) |
1da177e4 LT |
225 | { |
226 | unsigned long flags; | |
227 | ||
228 | /* | |
229 | * Keep taking off work from the queue until | |
230 | * done. | |
231 | */ | |
232 | spin_lock_irqsave(&cwq->lock, flags); | |
233 | cwq->run_depth++; | |
234 | if (cwq->run_depth > 3) { | |
235 | /* morton gets to eat his hat */ | |
236 | printk("%s: recursion depth exceeded: %d\n", | |
237 | __FUNCTION__, cwq->run_depth); | |
238 | dump_stack(); | |
239 | } | |
240 | while (!list_empty(&cwq->worklist)) { | |
241 | struct work_struct *work = list_entry(cwq->worklist.next, | |
242 | struct work_struct, entry); | |
6bb49e59 | 243 | work_func_t f = work->func; |
1da177e4 LT |
244 | |
245 | list_del_init(cwq->worklist.next); | |
246 | spin_unlock_irqrestore(&cwq->lock, flags); | |
247 | ||
365970a1 | 248 | BUG_ON(get_wq_data(work) != cwq); |
65f27f38 DH |
249 | if (!test_bit(WORK_STRUCT_NOAUTOREL, &work->management)) |
250 | work_release(work); | |
251 | f(work); | |
1da177e4 LT |
252 | |
253 | spin_lock_irqsave(&cwq->lock, flags); | |
254 | cwq->remove_sequence++; | |
255 | wake_up(&cwq->work_done); | |
256 | } | |
257 | cwq->run_depth--; | |
258 | spin_unlock_irqrestore(&cwq->lock, flags); | |
259 | } | |
260 | ||
261 | static int worker_thread(void *__cwq) | |
262 | { | |
263 | struct cpu_workqueue_struct *cwq = __cwq; | |
264 | DECLARE_WAITQUEUE(wait, current); | |
265 | struct k_sigaction sa; | |
266 | sigset_t blocked; | |
267 | ||
268 | current->flags |= PF_NOFREEZE; | |
269 | ||
270 | set_user_nice(current, -5); | |
271 | ||
272 | /* Block and flush all signals */ | |
273 | sigfillset(&blocked); | |
274 | sigprocmask(SIG_BLOCK, &blocked, NULL); | |
275 | flush_signals(current); | |
276 | ||
46934023 CL |
277 | /* |
278 | * We inherited MPOL_INTERLEAVE from the booting kernel. | |
279 | * Set MPOL_DEFAULT to insure node local allocations. | |
280 | */ | |
281 | numa_default_policy(); | |
282 | ||
1da177e4 LT |
283 | /* SIG_IGN makes children autoreap: see do_notify_parent(). */ |
284 | sa.sa.sa_handler = SIG_IGN; | |
285 | sa.sa.sa_flags = 0; | |
286 | siginitset(&sa.sa.sa_mask, sigmask(SIGCHLD)); | |
287 | do_sigaction(SIGCHLD, &sa, (struct k_sigaction *)0); | |
288 | ||
289 | set_current_state(TASK_INTERRUPTIBLE); | |
290 | while (!kthread_should_stop()) { | |
291 | add_wait_queue(&cwq->more_work, &wait); | |
292 | if (list_empty(&cwq->worklist)) | |
293 | schedule(); | |
294 | else | |
295 | __set_current_state(TASK_RUNNING); | |
296 | remove_wait_queue(&cwq->more_work, &wait); | |
297 | ||
298 | if (!list_empty(&cwq->worklist)) | |
299 | run_workqueue(cwq); | |
300 | set_current_state(TASK_INTERRUPTIBLE); | |
301 | } | |
302 | __set_current_state(TASK_RUNNING); | |
303 | return 0; | |
304 | } | |
305 | ||
306 | static void flush_cpu_workqueue(struct cpu_workqueue_struct *cwq) | |
307 | { | |
308 | if (cwq->thread == current) { | |
309 | /* | |
310 | * Probably keventd trying to flush its own queue. So simply run | |
311 | * it by hand rather than deadlocking. | |
312 | */ | |
313 | run_workqueue(cwq); | |
314 | } else { | |
315 | DEFINE_WAIT(wait); | |
316 | long sequence_needed; | |
317 | ||
318 | spin_lock_irq(&cwq->lock); | |
319 | sequence_needed = cwq->insert_sequence; | |
320 | ||
321 | while (sequence_needed - cwq->remove_sequence > 0) { | |
322 | prepare_to_wait(&cwq->work_done, &wait, | |
323 | TASK_UNINTERRUPTIBLE); | |
324 | spin_unlock_irq(&cwq->lock); | |
325 | schedule(); | |
326 | spin_lock_irq(&cwq->lock); | |
327 | } | |
328 | finish_wait(&cwq->work_done, &wait); | |
329 | spin_unlock_irq(&cwq->lock); | |
330 | } | |
331 | } | |
332 | ||
0fcb78c2 | 333 | /** |
1da177e4 | 334 | * flush_workqueue - ensure that any scheduled work has run to completion. |
0fcb78c2 | 335 | * @wq: workqueue to flush |
1da177e4 LT |
336 | * |
337 | * Forces execution of the workqueue and blocks until its completion. | |
338 | * This is typically used in driver shutdown handlers. | |
339 | * | |
340 | * This function will sample each workqueue's current insert_sequence number and | |
341 | * will sleep until the head sequence is greater than or equal to that. This | |
342 | * means that we sleep until all works which were queued on entry have been | |
343 | * handled, but we are not livelocked by new incoming ones. | |
344 | * | |
345 | * This function used to run the workqueues itself. Now we just wait for the | |
346 | * helper threads to do it. | |
347 | */ | |
348 | void fastcall flush_workqueue(struct workqueue_struct *wq) | |
349 | { | |
350 | might_sleep(); | |
351 | ||
352 | if (is_single_threaded(wq)) { | |
bce61dd4 | 353 | /* Always use first cpu's area. */ |
f756d5e2 | 354 | flush_cpu_workqueue(per_cpu_ptr(wq->cpu_wq, singlethread_cpu)); |
1da177e4 LT |
355 | } else { |
356 | int cpu; | |
357 | ||
9b41ea72 | 358 | mutex_lock(&workqueue_mutex); |
1da177e4 | 359 | for_each_online_cpu(cpu) |
89ada679 | 360 | flush_cpu_workqueue(per_cpu_ptr(wq->cpu_wq, cpu)); |
9b41ea72 | 361 | mutex_unlock(&workqueue_mutex); |
1da177e4 LT |
362 | } |
363 | } | |
ae90dd5d | 364 | EXPORT_SYMBOL_GPL(flush_workqueue); |
1da177e4 LT |
365 | |
366 | static struct task_struct *create_workqueue_thread(struct workqueue_struct *wq, | |
367 | int cpu) | |
368 | { | |
89ada679 | 369 | struct cpu_workqueue_struct *cwq = per_cpu_ptr(wq->cpu_wq, cpu); |
1da177e4 LT |
370 | struct task_struct *p; |
371 | ||
372 | spin_lock_init(&cwq->lock); | |
373 | cwq->wq = wq; | |
374 | cwq->thread = NULL; | |
375 | cwq->insert_sequence = 0; | |
376 | cwq->remove_sequence = 0; | |
377 | INIT_LIST_HEAD(&cwq->worklist); | |
378 | init_waitqueue_head(&cwq->more_work); | |
379 | init_waitqueue_head(&cwq->work_done); | |
380 | ||
381 | if (is_single_threaded(wq)) | |
382 | p = kthread_create(worker_thread, cwq, "%s", wq->name); | |
383 | else | |
384 | p = kthread_create(worker_thread, cwq, "%s/%d", wq->name, cpu); | |
385 | if (IS_ERR(p)) | |
386 | return NULL; | |
387 | cwq->thread = p; | |
388 | return p; | |
389 | } | |
390 | ||
391 | struct workqueue_struct *__create_workqueue(const char *name, | |
392 | int singlethread) | |
393 | { | |
394 | int cpu, destroy = 0; | |
395 | struct workqueue_struct *wq; | |
396 | struct task_struct *p; | |
397 | ||
dd392710 | 398 | wq = kzalloc(sizeof(*wq), GFP_KERNEL); |
1da177e4 LT |
399 | if (!wq) |
400 | return NULL; | |
1da177e4 | 401 | |
89ada679 | 402 | wq->cpu_wq = alloc_percpu(struct cpu_workqueue_struct); |
676121fc BC |
403 | if (!wq->cpu_wq) { |
404 | kfree(wq); | |
405 | return NULL; | |
406 | } | |
407 | ||
1da177e4 | 408 | wq->name = name; |
9b41ea72 | 409 | mutex_lock(&workqueue_mutex); |
1da177e4 LT |
410 | if (singlethread) { |
411 | INIT_LIST_HEAD(&wq->list); | |
f756d5e2 | 412 | p = create_workqueue_thread(wq, singlethread_cpu); |
1da177e4 LT |
413 | if (!p) |
414 | destroy = 1; | |
415 | else | |
416 | wake_up_process(p); | |
417 | } else { | |
1da177e4 | 418 | list_add(&wq->list, &workqueues); |
1da177e4 LT |
419 | for_each_online_cpu(cpu) { |
420 | p = create_workqueue_thread(wq, cpu); | |
421 | if (p) { | |
422 | kthread_bind(p, cpu); | |
423 | wake_up_process(p); | |
424 | } else | |
425 | destroy = 1; | |
426 | } | |
427 | } | |
9b41ea72 | 428 | mutex_unlock(&workqueue_mutex); |
1da177e4 LT |
429 | |
430 | /* | |
431 | * Was there any error during startup? If yes then clean up: | |
432 | */ | |
433 | if (destroy) { | |
434 | destroy_workqueue(wq); | |
435 | wq = NULL; | |
436 | } | |
437 | return wq; | |
438 | } | |
ae90dd5d | 439 | EXPORT_SYMBOL_GPL(__create_workqueue); |
1da177e4 LT |
440 | |
441 | static void cleanup_workqueue_thread(struct workqueue_struct *wq, int cpu) | |
442 | { | |
443 | struct cpu_workqueue_struct *cwq; | |
444 | unsigned long flags; | |
445 | struct task_struct *p; | |
446 | ||
89ada679 | 447 | cwq = per_cpu_ptr(wq->cpu_wq, cpu); |
1da177e4 LT |
448 | spin_lock_irqsave(&cwq->lock, flags); |
449 | p = cwq->thread; | |
450 | cwq->thread = NULL; | |
451 | spin_unlock_irqrestore(&cwq->lock, flags); | |
452 | if (p) | |
453 | kthread_stop(p); | |
454 | } | |
455 | ||
0fcb78c2 REB |
456 | /** |
457 | * destroy_workqueue - safely terminate a workqueue | |
458 | * @wq: target workqueue | |
459 | * | |
460 | * Safely destroy a workqueue. All work currently pending will be done first. | |
461 | */ | |
1da177e4 LT |
462 | void destroy_workqueue(struct workqueue_struct *wq) |
463 | { | |
464 | int cpu; | |
465 | ||
466 | flush_workqueue(wq); | |
467 | ||
468 | /* We don't need the distraction of CPUs appearing and vanishing. */ | |
9b41ea72 | 469 | mutex_lock(&workqueue_mutex); |
1da177e4 | 470 | if (is_single_threaded(wq)) |
f756d5e2 | 471 | cleanup_workqueue_thread(wq, singlethread_cpu); |
1da177e4 LT |
472 | else { |
473 | for_each_online_cpu(cpu) | |
474 | cleanup_workqueue_thread(wq, cpu); | |
1da177e4 | 475 | list_del(&wq->list); |
1da177e4 | 476 | } |
9b41ea72 | 477 | mutex_unlock(&workqueue_mutex); |
89ada679 | 478 | free_percpu(wq->cpu_wq); |
1da177e4 LT |
479 | kfree(wq); |
480 | } | |
ae90dd5d | 481 | EXPORT_SYMBOL_GPL(destroy_workqueue); |
1da177e4 LT |
482 | |
483 | static struct workqueue_struct *keventd_wq; | |
484 | ||
0fcb78c2 REB |
485 | /** |
486 | * schedule_work - put work task in global workqueue | |
487 | * @work: job to be done | |
488 | * | |
489 | * This puts a job in the kernel-global workqueue. | |
490 | */ | |
1da177e4 LT |
491 | int fastcall schedule_work(struct work_struct *work) |
492 | { | |
493 | return queue_work(keventd_wq, work); | |
494 | } | |
ae90dd5d | 495 | EXPORT_SYMBOL(schedule_work); |
1da177e4 | 496 | |
0fcb78c2 REB |
497 | /** |
498 | * schedule_delayed_work - put work task in global workqueue after delay | |
52bad64d DH |
499 | * @dwork: job to be done |
500 | * @delay: number of jiffies to wait or 0 for immediate execution | |
0fcb78c2 REB |
501 | * |
502 | * After waiting for a given time this puts a job in the kernel-global | |
503 | * workqueue. | |
504 | */ | |
52bad64d | 505 | int fastcall schedule_delayed_work(struct delayed_work *dwork, unsigned long delay) |
1da177e4 | 506 | { |
52bad64d | 507 | return queue_delayed_work(keventd_wq, dwork, delay); |
1da177e4 | 508 | } |
ae90dd5d | 509 | EXPORT_SYMBOL(schedule_delayed_work); |
1da177e4 | 510 | |
0fcb78c2 REB |
511 | /** |
512 | * schedule_delayed_work_on - queue work in global workqueue on CPU after delay | |
513 | * @cpu: cpu to use | |
52bad64d | 514 | * @dwork: job to be done |
0fcb78c2 REB |
515 | * @delay: number of jiffies to wait |
516 | * | |
517 | * After waiting for a given time this puts a job in the kernel-global | |
518 | * workqueue on the specified CPU. | |
519 | */ | |
1da177e4 | 520 | int schedule_delayed_work_on(int cpu, |
52bad64d | 521 | struct delayed_work *dwork, unsigned long delay) |
1da177e4 | 522 | { |
52bad64d | 523 | return queue_delayed_work_on(cpu, keventd_wq, dwork, delay); |
1da177e4 | 524 | } |
ae90dd5d | 525 | EXPORT_SYMBOL(schedule_delayed_work_on); |
1da177e4 | 526 | |
b6136773 AM |
527 | /** |
528 | * schedule_on_each_cpu - call a function on each online CPU from keventd | |
529 | * @func: the function to call | |
b6136773 AM |
530 | * |
531 | * Returns zero on success. | |
532 | * Returns -ve errno on failure. | |
533 | * | |
534 | * Appears to be racy against CPU hotplug. | |
535 | * | |
536 | * schedule_on_each_cpu() is very slow. | |
537 | */ | |
65f27f38 | 538 | int schedule_on_each_cpu(work_func_t func) |
15316ba8 CL |
539 | { |
540 | int cpu; | |
b6136773 | 541 | struct work_struct *works; |
15316ba8 | 542 | |
b6136773 AM |
543 | works = alloc_percpu(struct work_struct); |
544 | if (!works) | |
15316ba8 | 545 | return -ENOMEM; |
b6136773 | 546 | |
9b41ea72 | 547 | mutex_lock(&workqueue_mutex); |
15316ba8 | 548 | for_each_online_cpu(cpu) { |
65f27f38 | 549 | INIT_WORK(per_cpu_ptr(works, cpu), func); |
15316ba8 | 550 | __queue_work(per_cpu_ptr(keventd_wq->cpu_wq, cpu), |
b6136773 | 551 | per_cpu_ptr(works, cpu)); |
15316ba8 | 552 | } |
9b41ea72 | 553 | mutex_unlock(&workqueue_mutex); |
15316ba8 | 554 | flush_workqueue(keventd_wq); |
b6136773 | 555 | free_percpu(works); |
15316ba8 CL |
556 | return 0; |
557 | } | |
558 | ||
1da177e4 LT |
559 | void flush_scheduled_work(void) |
560 | { | |
561 | flush_workqueue(keventd_wq); | |
562 | } | |
ae90dd5d | 563 | EXPORT_SYMBOL(flush_scheduled_work); |
1da177e4 LT |
564 | |
565 | /** | |
566 | * cancel_rearming_delayed_workqueue - reliably kill off a delayed | |
567 | * work whose handler rearms the delayed work. | |
568 | * @wq: the controlling workqueue structure | |
52bad64d | 569 | * @dwork: the delayed work struct |
1da177e4 | 570 | */ |
81ddef77 | 571 | void cancel_rearming_delayed_workqueue(struct workqueue_struct *wq, |
52bad64d | 572 | struct delayed_work *dwork) |
1da177e4 | 573 | { |
52bad64d | 574 | while (!cancel_delayed_work(dwork)) |
1da177e4 LT |
575 | flush_workqueue(wq); |
576 | } | |
81ddef77 | 577 | EXPORT_SYMBOL(cancel_rearming_delayed_workqueue); |
1da177e4 LT |
578 | |
579 | /** | |
580 | * cancel_rearming_delayed_work - reliably kill off a delayed keventd | |
581 | * work whose handler rearms the delayed work. | |
52bad64d | 582 | * @dwork: the delayed work struct |
1da177e4 | 583 | */ |
52bad64d | 584 | void cancel_rearming_delayed_work(struct delayed_work *dwork) |
1da177e4 | 585 | { |
52bad64d | 586 | cancel_rearming_delayed_workqueue(keventd_wq, dwork); |
1da177e4 LT |
587 | } |
588 | EXPORT_SYMBOL(cancel_rearming_delayed_work); | |
589 | ||
1fa44eca JB |
590 | /** |
591 | * execute_in_process_context - reliably execute the routine with user context | |
592 | * @fn: the function to execute | |
1fa44eca JB |
593 | * @ew: guaranteed storage for the execute work structure (must |
594 | * be available when the work executes) | |
595 | * | |
596 | * Executes the function immediately if process context is available, | |
597 | * otherwise schedules the function for delayed execution. | |
598 | * | |
599 | * Returns: 0 - function was executed | |
600 | * 1 - function was scheduled for execution | |
601 | */ | |
65f27f38 | 602 | int execute_in_process_context(work_func_t fn, struct execute_work *ew) |
1fa44eca JB |
603 | { |
604 | if (!in_interrupt()) { | |
65f27f38 | 605 | fn(&ew->work); |
1fa44eca JB |
606 | return 0; |
607 | } | |
608 | ||
65f27f38 | 609 | INIT_WORK(&ew->work, fn); |
1fa44eca JB |
610 | schedule_work(&ew->work); |
611 | ||
612 | return 1; | |
613 | } | |
614 | EXPORT_SYMBOL_GPL(execute_in_process_context); | |
615 | ||
1da177e4 LT |
616 | int keventd_up(void) |
617 | { | |
618 | return keventd_wq != NULL; | |
619 | } | |
620 | ||
621 | int current_is_keventd(void) | |
622 | { | |
623 | struct cpu_workqueue_struct *cwq; | |
624 | int cpu = smp_processor_id(); /* preempt-safe: keventd is per-cpu */ | |
625 | int ret = 0; | |
626 | ||
627 | BUG_ON(!keventd_wq); | |
628 | ||
89ada679 | 629 | cwq = per_cpu_ptr(keventd_wq->cpu_wq, cpu); |
1da177e4 LT |
630 | if (current == cwq->thread) |
631 | ret = 1; | |
632 | ||
633 | return ret; | |
634 | ||
635 | } | |
636 | ||
637 | #ifdef CONFIG_HOTPLUG_CPU | |
638 | /* Take the work from this (downed) CPU. */ | |
639 | static void take_over_work(struct workqueue_struct *wq, unsigned int cpu) | |
640 | { | |
89ada679 | 641 | struct cpu_workqueue_struct *cwq = per_cpu_ptr(wq->cpu_wq, cpu); |
626ab0e6 | 642 | struct list_head list; |
1da177e4 LT |
643 | struct work_struct *work; |
644 | ||
645 | spin_lock_irq(&cwq->lock); | |
626ab0e6 | 646 | list_replace_init(&cwq->worklist, &list); |
1da177e4 LT |
647 | |
648 | while (!list_empty(&list)) { | |
649 | printk("Taking work for %s\n", wq->name); | |
650 | work = list_entry(list.next,struct work_struct,entry); | |
651 | list_del(&work->entry); | |
89ada679 | 652 | __queue_work(per_cpu_ptr(wq->cpu_wq, smp_processor_id()), work); |
1da177e4 LT |
653 | } |
654 | spin_unlock_irq(&cwq->lock); | |
655 | } | |
656 | ||
657 | /* We're holding the cpucontrol mutex here */ | |
9c7b216d | 658 | static int __devinit workqueue_cpu_callback(struct notifier_block *nfb, |
1da177e4 LT |
659 | unsigned long action, |
660 | void *hcpu) | |
661 | { | |
662 | unsigned int hotcpu = (unsigned long)hcpu; | |
663 | struct workqueue_struct *wq; | |
664 | ||
665 | switch (action) { | |
666 | case CPU_UP_PREPARE: | |
9b41ea72 | 667 | mutex_lock(&workqueue_mutex); |
1da177e4 LT |
668 | /* Create a new workqueue thread for it. */ |
669 | list_for_each_entry(wq, &workqueues, list) { | |
230649da | 670 | if (!create_workqueue_thread(wq, hotcpu)) { |
1da177e4 LT |
671 | printk("workqueue for %i failed\n", hotcpu); |
672 | return NOTIFY_BAD; | |
673 | } | |
674 | } | |
675 | break; | |
676 | ||
677 | case CPU_ONLINE: | |
678 | /* Kick off worker threads. */ | |
679 | list_for_each_entry(wq, &workqueues, list) { | |
89ada679 CL |
680 | struct cpu_workqueue_struct *cwq; |
681 | ||
682 | cwq = per_cpu_ptr(wq->cpu_wq, hotcpu); | |
683 | kthread_bind(cwq->thread, hotcpu); | |
684 | wake_up_process(cwq->thread); | |
1da177e4 | 685 | } |
9b41ea72 | 686 | mutex_unlock(&workqueue_mutex); |
1da177e4 LT |
687 | break; |
688 | ||
689 | case CPU_UP_CANCELED: | |
690 | list_for_each_entry(wq, &workqueues, list) { | |
fc75cdfa HC |
691 | if (!per_cpu_ptr(wq->cpu_wq, hotcpu)->thread) |
692 | continue; | |
1da177e4 | 693 | /* Unbind so it can run. */ |
89ada679 | 694 | kthread_bind(per_cpu_ptr(wq->cpu_wq, hotcpu)->thread, |
a4c4af7c | 695 | any_online_cpu(cpu_online_map)); |
1da177e4 LT |
696 | cleanup_workqueue_thread(wq, hotcpu); |
697 | } | |
9b41ea72 AM |
698 | mutex_unlock(&workqueue_mutex); |
699 | break; | |
700 | ||
701 | case CPU_DOWN_PREPARE: | |
702 | mutex_lock(&workqueue_mutex); | |
703 | break; | |
704 | ||
705 | case CPU_DOWN_FAILED: | |
706 | mutex_unlock(&workqueue_mutex); | |
1da177e4 LT |
707 | break; |
708 | ||
709 | case CPU_DEAD: | |
710 | list_for_each_entry(wq, &workqueues, list) | |
711 | cleanup_workqueue_thread(wq, hotcpu); | |
712 | list_for_each_entry(wq, &workqueues, list) | |
713 | take_over_work(wq, hotcpu); | |
9b41ea72 | 714 | mutex_unlock(&workqueue_mutex); |
1da177e4 LT |
715 | break; |
716 | } | |
717 | ||
718 | return NOTIFY_OK; | |
719 | } | |
720 | #endif | |
721 | ||
722 | void init_workqueues(void) | |
723 | { | |
f756d5e2 | 724 | singlethread_cpu = first_cpu(cpu_possible_map); |
1da177e4 LT |
725 | hotcpu_notifier(workqueue_cpu_callback, 0); |
726 | keventd_wq = create_workqueue("events"); | |
727 | BUG_ON(!keventd_wq); | |
728 | } | |
729 |