]>
Commit | Line | Data |
---|---|---|
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> |
d5abe669 PZ |
33 | #include <linux/kallsyms.h> |
34 | #include <linux/debug_locks.h> | |
1da177e4 LT |
35 | |
36 | /* | |
f756d5e2 NL |
37 | * The per-CPU workqueue (if single thread, we always use the first |
38 | * possible cpu). | |
1da177e4 LT |
39 | * |
40 | * The sequence counters are for flush_scheduled_work(). It wants to wait | |
9f5d785e | 41 | * until all currently-scheduled works are completed, but it doesn't |
1da177e4 LT |
42 | * want to be livelocked by new, incoming ones. So it waits until |
43 | * remove_sequence is >= the insert_sequence which pertained when | |
44 | * flush_scheduled_work() was called. | |
45 | */ | |
46 | struct cpu_workqueue_struct { | |
47 | ||
48 | spinlock_t lock; | |
49 | ||
50 | long remove_sequence; /* Least-recently added (next to run) */ | |
51 | long insert_sequence; /* Next to add */ | |
52 | ||
53 | struct list_head worklist; | |
54 | wait_queue_head_t more_work; | |
55 | wait_queue_head_t work_done; | |
56 | ||
57 | struct workqueue_struct *wq; | |
36c8b586 | 58 | struct task_struct *thread; |
1da177e4 LT |
59 | |
60 | int run_depth; /* Detect run_workqueue() recursion depth */ | |
341a5958 RW |
61 | |
62 | int freezeable; /* Freeze the thread during suspend */ | |
1da177e4 LT |
63 | } ____cacheline_aligned; |
64 | ||
65 | /* | |
66 | * The externally visible workqueue abstraction is an array of | |
67 | * per-CPU workqueues: | |
68 | */ | |
69 | struct workqueue_struct { | |
89ada679 | 70 | struct cpu_workqueue_struct *cpu_wq; |
1da177e4 LT |
71 | const char *name; |
72 | struct list_head list; /* Empty if single thread */ | |
73 | }; | |
74 | ||
75 | /* All the per-cpu workqueues on the system, for hotplug cpu to add/remove | |
76 | threads to each one as cpus come/go. */ | |
9b41ea72 | 77 | static DEFINE_MUTEX(workqueue_mutex); |
1da177e4 LT |
78 | static LIST_HEAD(workqueues); |
79 | ||
f756d5e2 NL |
80 | static int singlethread_cpu; |
81 | ||
1da177e4 LT |
82 | /* If it's single threaded, it isn't in the list of workqueues. */ |
83 | static inline int is_single_threaded(struct workqueue_struct *wq) | |
84 | { | |
85 | return list_empty(&wq->list); | |
86 | } | |
87 | ||
365970a1 DH |
88 | static inline void set_wq_data(struct work_struct *work, void *wq) |
89 | { | |
90 | unsigned long new, old, res; | |
91 | ||
92 | /* assume the pending flag is already set and that the task has already | |
93 | * been queued on this workqueue */ | |
94 | new = (unsigned long) wq | (1UL << WORK_STRUCT_PENDING); | |
95 | res = work->management; | |
96 | if (res != new) { | |
97 | do { | |
98 | old = res; | |
99 | new = (unsigned long) wq; | |
100 | new |= (old & WORK_STRUCT_FLAG_MASK); | |
101 | res = cmpxchg(&work->management, old, new); | |
102 | } while (res != old); | |
103 | } | |
104 | } | |
105 | ||
106 | static inline void *get_wq_data(struct work_struct *work) | |
107 | { | |
108 | return (void *) (work->management & WORK_STRUCT_WQ_DATA_MASK); | |
109 | } | |
110 | ||
1da177e4 LT |
111 | /* Preempt must be disabled. */ |
112 | static void __queue_work(struct cpu_workqueue_struct *cwq, | |
113 | struct work_struct *work) | |
114 | { | |
115 | unsigned long flags; | |
116 | ||
117 | spin_lock_irqsave(&cwq->lock, flags); | |
365970a1 | 118 | set_wq_data(work, cwq); |
1da177e4 LT |
119 | list_add_tail(&work->entry, &cwq->worklist); |
120 | cwq->insert_sequence++; | |
121 | wake_up(&cwq->more_work); | |
122 | spin_unlock_irqrestore(&cwq->lock, flags); | |
123 | } | |
124 | ||
0fcb78c2 REB |
125 | /** |
126 | * queue_work - queue work on a workqueue | |
127 | * @wq: workqueue to use | |
128 | * @work: work to queue | |
129 | * | |
057647fc | 130 | * Returns 0 if @work was already on a queue, non-zero otherwise. |
1da177e4 LT |
131 | * |
132 | * We queue the work to the CPU it was submitted, but there is no | |
133 | * guarantee that it will be processed by that CPU. | |
134 | */ | |
135 | int fastcall queue_work(struct workqueue_struct *wq, struct work_struct *work) | |
136 | { | |
137 | int ret = 0, cpu = get_cpu(); | |
138 | ||
365970a1 | 139 | if (!test_and_set_bit(WORK_STRUCT_PENDING, &work->management)) { |
1da177e4 | 140 | if (unlikely(is_single_threaded(wq))) |
f756d5e2 | 141 | cpu = singlethread_cpu; |
1da177e4 | 142 | BUG_ON(!list_empty(&work->entry)); |
89ada679 | 143 | __queue_work(per_cpu_ptr(wq->cpu_wq, cpu), work); |
1da177e4 LT |
144 | ret = 1; |
145 | } | |
146 | put_cpu(); | |
147 | return ret; | |
148 | } | |
ae90dd5d | 149 | EXPORT_SYMBOL_GPL(queue_work); |
1da177e4 LT |
150 | |
151 | static void delayed_work_timer_fn(unsigned long __data) | |
152 | { | |
52bad64d | 153 | struct delayed_work *dwork = (struct delayed_work *)__data; |
365970a1 | 154 | struct workqueue_struct *wq = get_wq_data(&dwork->work); |
1da177e4 LT |
155 | int cpu = smp_processor_id(); |
156 | ||
157 | if (unlikely(is_single_threaded(wq))) | |
f756d5e2 | 158 | cpu = singlethread_cpu; |
1da177e4 | 159 | |
52bad64d | 160 | __queue_work(per_cpu_ptr(wq->cpu_wq, cpu), &dwork->work); |
1da177e4 LT |
161 | } |
162 | ||
0fcb78c2 REB |
163 | /** |
164 | * queue_delayed_work - queue work on a workqueue after delay | |
165 | * @wq: workqueue to use | |
52bad64d | 166 | * @work: delayable work to queue |
0fcb78c2 REB |
167 | * @delay: number of jiffies to wait before queueing |
168 | * | |
057647fc | 169 | * Returns 0 if @work was already on a queue, non-zero otherwise. |
0fcb78c2 | 170 | */ |
1da177e4 | 171 | int fastcall queue_delayed_work(struct workqueue_struct *wq, |
52bad64d | 172 | struct delayed_work *dwork, unsigned long delay) |
1da177e4 LT |
173 | { |
174 | int ret = 0; | |
52bad64d DH |
175 | struct timer_list *timer = &dwork->timer; |
176 | struct work_struct *work = &dwork->work; | |
177 | ||
178 | if (delay == 0) | |
179 | return queue_work(wq, work); | |
1da177e4 | 180 | |
365970a1 | 181 | if (!test_and_set_bit(WORK_STRUCT_PENDING, &work->management)) { |
1da177e4 LT |
182 | BUG_ON(timer_pending(timer)); |
183 | BUG_ON(!list_empty(&work->entry)); | |
184 | ||
185 | /* This stores wq for the moment, for the timer_fn */ | |
365970a1 | 186 | set_wq_data(work, wq); |
1da177e4 | 187 | timer->expires = jiffies + delay; |
52bad64d | 188 | timer->data = (unsigned long)dwork; |
1da177e4 LT |
189 | timer->function = delayed_work_timer_fn; |
190 | add_timer(timer); | |
191 | ret = 1; | |
192 | } | |
193 | return ret; | |
194 | } | |
ae90dd5d | 195 | EXPORT_SYMBOL_GPL(queue_delayed_work); |
1da177e4 | 196 | |
0fcb78c2 REB |
197 | /** |
198 | * queue_delayed_work_on - queue work on specific CPU after delay | |
199 | * @cpu: CPU number to execute work on | |
200 | * @wq: workqueue to use | |
201 | * @work: work to queue | |
202 | * @delay: number of jiffies to wait before queueing | |
203 | * | |
057647fc | 204 | * Returns 0 if @work was already on a queue, non-zero otherwise. |
0fcb78c2 | 205 | */ |
7a6bc1cd | 206 | int queue_delayed_work_on(int cpu, struct workqueue_struct *wq, |
52bad64d | 207 | struct delayed_work *dwork, unsigned long delay) |
7a6bc1cd VP |
208 | { |
209 | int ret = 0; | |
52bad64d DH |
210 | struct timer_list *timer = &dwork->timer; |
211 | struct work_struct *work = &dwork->work; | |
7a6bc1cd | 212 | |
365970a1 | 213 | if (!test_and_set_bit(WORK_STRUCT_PENDING, &work->management)) { |
7a6bc1cd VP |
214 | BUG_ON(timer_pending(timer)); |
215 | BUG_ON(!list_empty(&work->entry)); | |
216 | ||
217 | /* This stores wq for the moment, for the timer_fn */ | |
365970a1 | 218 | set_wq_data(work, wq); |
7a6bc1cd | 219 | timer->expires = jiffies + delay; |
52bad64d | 220 | timer->data = (unsigned long)dwork; |
7a6bc1cd VP |
221 | timer->function = delayed_work_timer_fn; |
222 | add_timer_on(timer, cpu); | |
223 | ret = 1; | |
224 | } | |
225 | return ret; | |
226 | } | |
ae90dd5d | 227 | EXPORT_SYMBOL_GPL(queue_delayed_work_on); |
1da177e4 | 228 | |
858119e1 | 229 | static void run_workqueue(struct cpu_workqueue_struct *cwq) |
1da177e4 LT |
230 | { |
231 | unsigned long flags; | |
232 | ||
233 | /* | |
234 | * Keep taking off work from the queue until | |
235 | * done. | |
236 | */ | |
237 | spin_lock_irqsave(&cwq->lock, flags); | |
238 | cwq->run_depth++; | |
239 | if (cwq->run_depth > 3) { | |
240 | /* morton gets to eat his hat */ | |
241 | printk("%s: recursion depth exceeded: %d\n", | |
242 | __FUNCTION__, cwq->run_depth); | |
243 | dump_stack(); | |
244 | } | |
245 | while (!list_empty(&cwq->worklist)) { | |
246 | struct work_struct *work = list_entry(cwq->worklist.next, | |
247 | struct work_struct, entry); | |
6bb49e59 | 248 | work_func_t f = work->func; |
1da177e4 LT |
249 | |
250 | list_del_init(cwq->worklist.next); | |
251 | spin_unlock_irqrestore(&cwq->lock, flags); | |
252 | ||
365970a1 | 253 | BUG_ON(get_wq_data(work) != cwq); |
65f27f38 DH |
254 | if (!test_bit(WORK_STRUCT_NOAUTOREL, &work->management)) |
255 | work_release(work); | |
256 | f(work); | |
1da177e4 | 257 | |
d5abe669 PZ |
258 | if (unlikely(in_atomic() || lockdep_depth(current) > 0)) { |
259 | printk(KERN_ERR "BUG: workqueue leaked lock or atomic: " | |
260 | "%s/0x%08x/%d\n", | |
261 | current->comm, preempt_count(), | |
262 | current->pid); | |
263 | printk(KERN_ERR " last function: "); | |
264 | print_symbol("%s\n", (unsigned long)f); | |
265 | debug_show_held_locks(current); | |
266 | dump_stack(); | |
267 | } | |
268 | ||
1da177e4 LT |
269 | spin_lock_irqsave(&cwq->lock, flags); |
270 | cwq->remove_sequence++; | |
271 | wake_up(&cwq->work_done); | |
272 | } | |
273 | cwq->run_depth--; | |
274 | spin_unlock_irqrestore(&cwq->lock, flags); | |
275 | } | |
276 | ||
277 | static int worker_thread(void *__cwq) | |
278 | { | |
279 | struct cpu_workqueue_struct *cwq = __cwq; | |
280 | DECLARE_WAITQUEUE(wait, current); | |
281 | struct k_sigaction sa; | |
282 | sigset_t blocked; | |
283 | ||
341a5958 RW |
284 | if (!cwq->freezeable) |
285 | current->flags |= PF_NOFREEZE; | |
1da177e4 LT |
286 | |
287 | set_user_nice(current, -5); | |
288 | ||
289 | /* Block and flush all signals */ | |
290 | sigfillset(&blocked); | |
291 | sigprocmask(SIG_BLOCK, &blocked, NULL); | |
292 | flush_signals(current); | |
293 | ||
46934023 CL |
294 | /* |
295 | * We inherited MPOL_INTERLEAVE from the booting kernel. | |
296 | * Set MPOL_DEFAULT to insure node local allocations. | |
297 | */ | |
298 | numa_default_policy(); | |
299 | ||
1da177e4 LT |
300 | /* SIG_IGN makes children autoreap: see do_notify_parent(). */ |
301 | sa.sa.sa_handler = SIG_IGN; | |
302 | sa.sa.sa_flags = 0; | |
303 | siginitset(&sa.sa.sa_mask, sigmask(SIGCHLD)); | |
304 | do_sigaction(SIGCHLD, &sa, (struct k_sigaction *)0); | |
305 | ||
306 | set_current_state(TASK_INTERRUPTIBLE); | |
307 | while (!kthread_should_stop()) { | |
341a5958 RW |
308 | if (cwq->freezeable) |
309 | try_to_freeze(); | |
310 | ||
1da177e4 LT |
311 | add_wait_queue(&cwq->more_work, &wait); |
312 | if (list_empty(&cwq->worklist)) | |
313 | schedule(); | |
314 | else | |
315 | __set_current_state(TASK_RUNNING); | |
316 | remove_wait_queue(&cwq->more_work, &wait); | |
317 | ||
318 | if (!list_empty(&cwq->worklist)) | |
319 | run_workqueue(cwq); | |
320 | set_current_state(TASK_INTERRUPTIBLE); | |
321 | } | |
322 | __set_current_state(TASK_RUNNING); | |
323 | return 0; | |
324 | } | |
325 | ||
326 | static void flush_cpu_workqueue(struct cpu_workqueue_struct *cwq) | |
327 | { | |
328 | if (cwq->thread == current) { | |
329 | /* | |
330 | * Probably keventd trying to flush its own queue. So simply run | |
331 | * it by hand rather than deadlocking. | |
332 | */ | |
333 | run_workqueue(cwq); | |
334 | } else { | |
335 | DEFINE_WAIT(wait); | |
336 | long sequence_needed; | |
337 | ||
338 | spin_lock_irq(&cwq->lock); | |
339 | sequence_needed = cwq->insert_sequence; | |
340 | ||
341 | while (sequence_needed - cwq->remove_sequence > 0) { | |
342 | prepare_to_wait(&cwq->work_done, &wait, | |
343 | TASK_UNINTERRUPTIBLE); | |
344 | spin_unlock_irq(&cwq->lock); | |
345 | schedule(); | |
346 | spin_lock_irq(&cwq->lock); | |
347 | } | |
348 | finish_wait(&cwq->work_done, &wait); | |
349 | spin_unlock_irq(&cwq->lock); | |
350 | } | |
351 | } | |
352 | ||
0fcb78c2 | 353 | /** |
1da177e4 | 354 | * flush_workqueue - ensure that any scheduled work has run to completion. |
0fcb78c2 | 355 | * @wq: workqueue to flush |
1da177e4 LT |
356 | * |
357 | * Forces execution of the workqueue and blocks until its completion. | |
358 | * This is typically used in driver shutdown handlers. | |
359 | * | |
360 | * This function will sample each workqueue's current insert_sequence number and | |
361 | * will sleep until the head sequence is greater than or equal to that. This | |
362 | * means that we sleep until all works which were queued on entry have been | |
363 | * handled, but we are not livelocked by new incoming ones. | |
364 | * | |
365 | * This function used to run the workqueues itself. Now we just wait for the | |
366 | * helper threads to do it. | |
367 | */ | |
368 | void fastcall flush_workqueue(struct workqueue_struct *wq) | |
369 | { | |
370 | might_sleep(); | |
371 | ||
372 | if (is_single_threaded(wq)) { | |
bce61dd4 | 373 | /* Always use first cpu's area. */ |
f756d5e2 | 374 | flush_cpu_workqueue(per_cpu_ptr(wq->cpu_wq, singlethread_cpu)); |
1da177e4 LT |
375 | } else { |
376 | int cpu; | |
377 | ||
9b41ea72 | 378 | mutex_lock(&workqueue_mutex); |
1da177e4 | 379 | for_each_online_cpu(cpu) |
89ada679 | 380 | flush_cpu_workqueue(per_cpu_ptr(wq->cpu_wq, cpu)); |
9b41ea72 | 381 | mutex_unlock(&workqueue_mutex); |
1da177e4 LT |
382 | } |
383 | } | |
ae90dd5d | 384 | EXPORT_SYMBOL_GPL(flush_workqueue); |
1da177e4 LT |
385 | |
386 | static struct task_struct *create_workqueue_thread(struct workqueue_struct *wq, | |
341a5958 | 387 | int cpu, int freezeable) |
1da177e4 | 388 | { |
89ada679 | 389 | struct cpu_workqueue_struct *cwq = per_cpu_ptr(wq->cpu_wq, cpu); |
1da177e4 LT |
390 | struct task_struct *p; |
391 | ||
392 | spin_lock_init(&cwq->lock); | |
393 | cwq->wq = wq; | |
394 | cwq->thread = NULL; | |
395 | cwq->insert_sequence = 0; | |
396 | cwq->remove_sequence = 0; | |
341a5958 | 397 | cwq->freezeable = freezeable; |
1da177e4 LT |
398 | INIT_LIST_HEAD(&cwq->worklist); |
399 | init_waitqueue_head(&cwq->more_work); | |
400 | init_waitqueue_head(&cwq->work_done); | |
401 | ||
402 | if (is_single_threaded(wq)) | |
403 | p = kthread_create(worker_thread, cwq, "%s", wq->name); | |
404 | else | |
405 | p = kthread_create(worker_thread, cwq, "%s/%d", wq->name, cpu); | |
406 | if (IS_ERR(p)) | |
407 | return NULL; | |
408 | cwq->thread = p; | |
409 | return p; | |
410 | } | |
411 | ||
412 | struct workqueue_struct *__create_workqueue(const char *name, | |
341a5958 | 413 | int singlethread, int freezeable) |
1da177e4 LT |
414 | { |
415 | int cpu, destroy = 0; | |
416 | struct workqueue_struct *wq; | |
417 | struct task_struct *p; | |
418 | ||
dd392710 | 419 | wq = kzalloc(sizeof(*wq), GFP_KERNEL); |
1da177e4 LT |
420 | if (!wq) |
421 | return NULL; | |
1da177e4 | 422 | |
89ada679 | 423 | wq->cpu_wq = alloc_percpu(struct cpu_workqueue_struct); |
676121fc BC |
424 | if (!wq->cpu_wq) { |
425 | kfree(wq); | |
426 | return NULL; | |
427 | } | |
428 | ||
1da177e4 | 429 | wq->name = name; |
9b41ea72 | 430 | mutex_lock(&workqueue_mutex); |
1da177e4 LT |
431 | if (singlethread) { |
432 | INIT_LIST_HEAD(&wq->list); | |
341a5958 | 433 | p = create_workqueue_thread(wq, singlethread_cpu, freezeable); |
1da177e4 LT |
434 | if (!p) |
435 | destroy = 1; | |
436 | else | |
437 | wake_up_process(p); | |
438 | } else { | |
1da177e4 | 439 | list_add(&wq->list, &workqueues); |
1da177e4 | 440 | for_each_online_cpu(cpu) { |
341a5958 | 441 | p = create_workqueue_thread(wq, cpu, freezeable); |
1da177e4 LT |
442 | if (p) { |
443 | kthread_bind(p, cpu); | |
444 | wake_up_process(p); | |
445 | } else | |
446 | destroy = 1; | |
447 | } | |
448 | } | |
9b41ea72 | 449 | mutex_unlock(&workqueue_mutex); |
1da177e4 LT |
450 | |
451 | /* | |
452 | * Was there any error during startup? If yes then clean up: | |
453 | */ | |
454 | if (destroy) { | |
455 | destroy_workqueue(wq); | |
456 | wq = NULL; | |
457 | } | |
458 | return wq; | |
459 | } | |
ae90dd5d | 460 | EXPORT_SYMBOL_GPL(__create_workqueue); |
1da177e4 LT |
461 | |
462 | static void cleanup_workqueue_thread(struct workqueue_struct *wq, int cpu) | |
463 | { | |
464 | struct cpu_workqueue_struct *cwq; | |
465 | unsigned long flags; | |
466 | struct task_struct *p; | |
467 | ||
89ada679 | 468 | cwq = per_cpu_ptr(wq->cpu_wq, cpu); |
1da177e4 LT |
469 | spin_lock_irqsave(&cwq->lock, flags); |
470 | p = cwq->thread; | |
471 | cwq->thread = NULL; | |
472 | spin_unlock_irqrestore(&cwq->lock, flags); | |
473 | if (p) | |
474 | kthread_stop(p); | |
475 | } | |
476 | ||
0fcb78c2 REB |
477 | /** |
478 | * destroy_workqueue - safely terminate a workqueue | |
479 | * @wq: target workqueue | |
480 | * | |
481 | * Safely destroy a workqueue. All work currently pending will be done first. | |
482 | */ | |
1da177e4 LT |
483 | void destroy_workqueue(struct workqueue_struct *wq) |
484 | { | |
485 | int cpu; | |
486 | ||
487 | flush_workqueue(wq); | |
488 | ||
489 | /* We don't need the distraction of CPUs appearing and vanishing. */ | |
9b41ea72 | 490 | mutex_lock(&workqueue_mutex); |
1da177e4 | 491 | if (is_single_threaded(wq)) |
f756d5e2 | 492 | cleanup_workqueue_thread(wq, singlethread_cpu); |
1da177e4 LT |
493 | else { |
494 | for_each_online_cpu(cpu) | |
495 | cleanup_workqueue_thread(wq, cpu); | |
1da177e4 | 496 | list_del(&wq->list); |
1da177e4 | 497 | } |
9b41ea72 | 498 | mutex_unlock(&workqueue_mutex); |
89ada679 | 499 | free_percpu(wq->cpu_wq); |
1da177e4 LT |
500 | kfree(wq); |
501 | } | |
ae90dd5d | 502 | EXPORT_SYMBOL_GPL(destroy_workqueue); |
1da177e4 LT |
503 | |
504 | static struct workqueue_struct *keventd_wq; | |
505 | ||
0fcb78c2 REB |
506 | /** |
507 | * schedule_work - put work task in global workqueue | |
508 | * @work: job to be done | |
509 | * | |
510 | * This puts a job in the kernel-global workqueue. | |
511 | */ | |
1da177e4 LT |
512 | int fastcall schedule_work(struct work_struct *work) |
513 | { | |
514 | return queue_work(keventd_wq, work); | |
515 | } | |
ae90dd5d | 516 | EXPORT_SYMBOL(schedule_work); |
1da177e4 | 517 | |
0fcb78c2 REB |
518 | /** |
519 | * schedule_delayed_work - put work task in global workqueue after delay | |
52bad64d DH |
520 | * @dwork: job to be done |
521 | * @delay: number of jiffies to wait or 0 for immediate execution | |
0fcb78c2 REB |
522 | * |
523 | * After waiting for a given time this puts a job in the kernel-global | |
524 | * workqueue. | |
525 | */ | |
52bad64d | 526 | int fastcall schedule_delayed_work(struct delayed_work *dwork, unsigned long delay) |
1da177e4 | 527 | { |
52bad64d | 528 | return queue_delayed_work(keventd_wq, dwork, delay); |
1da177e4 | 529 | } |
ae90dd5d | 530 | EXPORT_SYMBOL(schedule_delayed_work); |
1da177e4 | 531 | |
0fcb78c2 REB |
532 | /** |
533 | * schedule_delayed_work_on - queue work in global workqueue on CPU after delay | |
534 | * @cpu: cpu to use | |
52bad64d | 535 | * @dwork: job to be done |
0fcb78c2 REB |
536 | * @delay: number of jiffies to wait |
537 | * | |
538 | * After waiting for a given time this puts a job in the kernel-global | |
539 | * workqueue on the specified CPU. | |
540 | */ | |
1da177e4 | 541 | int schedule_delayed_work_on(int cpu, |
52bad64d | 542 | struct delayed_work *dwork, unsigned long delay) |
1da177e4 | 543 | { |
52bad64d | 544 | return queue_delayed_work_on(cpu, keventd_wq, dwork, delay); |
1da177e4 | 545 | } |
ae90dd5d | 546 | EXPORT_SYMBOL(schedule_delayed_work_on); |
1da177e4 | 547 | |
b6136773 AM |
548 | /** |
549 | * schedule_on_each_cpu - call a function on each online CPU from keventd | |
550 | * @func: the function to call | |
b6136773 AM |
551 | * |
552 | * Returns zero on success. | |
553 | * Returns -ve errno on failure. | |
554 | * | |
555 | * Appears to be racy against CPU hotplug. | |
556 | * | |
557 | * schedule_on_each_cpu() is very slow. | |
558 | */ | |
65f27f38 | 559 | int schedule_on_each_cpu(work_func_t func) |
15316ba8 CL |
560 | { |
561 | int cpu; | |
b6136773 | 562 | struct work_struct *works; |
15316ba8 | 563 | |
b6136773 AM |
564 | works = alloc_percpu(struct work_struct); |
565 | if (!works) | |
15316ba8 | 566 | return -ENOMEM; |
b6136773 | 567 | |
9b41ea72 | 568 | mutex_lock(&workqueue_mutex); |
15316ba8 | 569 | for_each_online_cpu(cpu) { |
65f27f38 | 570 | INIT_WORK(per_cpu_ptr(works, cpu), func); |
15316ba8 | 571 | __queue_work(per_cpu_ptr(keventd_wq->cpu_wq, cpu), |
b6136773 | 572 | per_cpu_ptr(works, cpu)); |
15316ba8 | 573 | } |
9b41ea72 | 574 | mutex_unlock(&workqueue_mutex); |
15316ba8 | 575 | flush_workqueue(keventd_wq); |
b6136773 | 576 | free_percpu(works); |
15316ba8 CL |
577 | return 0; |
578 | } | |
579 | ||
1da177e4 LT |
580 | void flush_scheduled_work(void) |
581 | { | |
582 | flush_workqueue(keventd_wq); | |
583 | } | |
ae90dd5d | 584 | EXPORT_SYMBOL(flush_scheduled_work); |
1da177e4 LT |
585 | |
586 | /** | |
587 | * cancel_rearming_delayed_workqueue - reliably kill off a delayed | |
588 | * work whose handler rearms the delayed work. | |
589 | * @wq: the controlling workqueue structure | |
52bad64d | 590 | * @dwork: the delayed work struct |
1da177e4 | 591 | */ |
81ddef77 | 592 | void cancel_rearming_delayed_workqueue(struct workqueue_struct *wq, |
52bad64d | 593 | struct delayed_work *dwork) |
1da177e4 | 594 | { |
52bad64d | 595 | while (!cancel_delayed_work(dwork)) |
1da177e4 LT |
596 | flush_workqueue(wq); |
597 | } | |
81ddef77 | 598 | EXPORT_SYMBOL(cancel_rearming_delayed_workqueue); |
1da177e4 LT |
599 | |
600 | /** | |
601 | * cancel_rearming_delayed_work - reliably kill off a delayed keventd | |
602 | * work whose handler rearms the delayed work. | |
52bad64d | 603 | * @dwork: the delayed work struct |
1da177e4 | 604 | */ |
52bad64d | 605 | void cancel_rearming_delayed_work(struct delayed_work *dwork) |
1da177e4 | 606 | { |
52bad64d | 607 | cancel_rearming_delayed_workqueue(keventd_wq, dwork); |
1da177e4 LT |
608 | } |
609 | EXPORT_SYMBOL(cancel_rearming_delayed_work); | |
610 | ||
1fa44eca JB |
611 | /** |
612 | * execute_in_process_context - reliably execute the routine with user context | |
613 | * @fn: the function to execute | |
1fa44eca JB |
614 | * @ew: guaranteed storage for the execute work structure (must |
615 | * be available when the work executes) | |
616 | * | |
617 | * Executes the function immediately if process context is available, | |
618 | * otherwise schedules the function for delayed execution. | |
619 | * | |
620 | * Returns: 0 - function was executed | |
621 | * 1 - function was scheduled for execution | |
622 | */ | |
65f27f38 | 623 | int execute_in_process_context(work_func_t fn, struct execute_work *ew) |
1fa44eca JB |
624 | { |
625 | if (!in_interrupt()) { | |
65f27f38 | 626 | fn(&ew->work); |
1fa44eca JB |
627 | return 0; |
628 | } | |
629 | ||
65f27f38 | 630 | INIT_WORK(&ew->work, fn); |
1fa44eca JB |
631 | schedule_work(&ew->work); |
632 | ||
633 | return 1; | |
634 | } | |
635 | EXPORT_SYMBOL_GPL(execute_in_process_context); | |
636 | ||
1da177e4 LT |
637 | int keventd_up(void) |
638 | { | |
639 | return keventd_wq != NULL; | |
640 | } | |
641 | ||
642 | int current_is_keventd(void) | |
643 | { | |
644 | struct cpu_workqueue_struct *cwq; | |
645 | int cpu = smp_processor_id(); /* preempt-safe: keventd is per-cpu */ | |
646 | int ret = 0; | |
647 | ||
648 | BUG_ON(!keventd_wq); | |
649 | ||
89ada679 | 650 | cwq = per_cpu_ptr(keventd_wq->cpu_wq, cpu); |
1da177e4 LT |
651 | if (current == cwq->thread) |
652 | ret = 1; | |
653 | ||
654 | return ret; | |
655 | ||
656 | } | |
657 | ||
658 | #ifdef CONFIG_HOTPLUG_CPU | |
659 | /* Take the work from this (downed) CPU. */ | |
660 | static void take_over_work(struct workqueue_struct *wq, unsigned int cpu) | |
661 | { | |
89ada679 | 662 | struct cpu_workqueue_struct *cwq = per_cpu_ptr(wq->cpu_wq, cpu); |
626ab0e6 | 663 | struct list_head list; |
1da177e4 LT |
664 | struct work_struct *work; |
665 | ||
666 | spin_lock_irq(&cwq->lock); | |
626ab0e6 | 667 | list_replace_init(&cwq->worklist, &list); |
1da177e4 LT |
668 | |
669 | while (!list_empty(&list)) { | |
670 | printk("Taking work for %s\n", wq->name); | |
671 | work = list_entry(list.next,struct work_struct,entry); | |
672 | list_del(&work->entry); | |
89ada679 | 673 | __queue_work(per_cpu_ptr(wq->cpu_wq, smp_processor_id()), work); |
1da177e4 LT |
674 | } |
675 | spin_unlock_irq(&cwq->lock); | |
676 | } | |
677 | ||
678 | /* We're holding the cpucontrol mutex here */ | |
9c7b216d | 679 | static int __devinit workqueue_cpu_callback(struct notifier_block *nfb, |
1da177e4 LT |
680 | unsigned long action, |
681 | void *hcpu) | |
682 | { | |
683 | unsigned int hotcpu = (unsigned long)hcpu; | |
684 | struct workqueue_struct *wq; | |
685 | ||
686 | switch (action) { | |
687 | case CPU_UP_PREPARE: | |
9b41ea72 | 688 | mutex_lock(&workqueue_mutex); |
1da177e4 LT |
689 | /* Create a new workqueue thread for it. */ |
690 | list_for_each_entry(wq, &workqueues, list) { | |
341a5958 | 691 | if (!create_workqueue_thread(wq, hotcpu, 0)) { |
1da177e4 LT |
692 | printk("workqueue for %i failed\n", hotcpu); |
693 | return NOTIFY_BAD; | |
694 | } | |
695 | } | |
696 | break; | |
697 | ||
698 | case CPU_ONLINE: | |
699 | /* Kick off worker threads. */ | |
700 | list_for_each_entry(wq, &workqueues, list) { | |
89ada679 CL |
701 | struct cpu_workqueue_struct *cwq; |
702 | ||
703 | cwq = per_cpu_ptr(wq->cpu_wq, hotcpu); | |
704 | kthread_bind(cwq->thread, hotcpu); | |
705 | wake_up_process(cwq->thread); | |
1da177e4 | 706 | } |
9b41ea72 | 707 | mutex_unlock(&workqueue_mutex); |
1da177e4 LT |
708 | break; |
709 | ||
710 | case CPU_UP_CANCELED: | |
711 | list_for_each_entry(wq, &workqueues, list) { | |
fc75cdfa HC |
712 | if (!per_cpu_ptr(wq->cpu_wq, hotcpu)->thread) |
713 | continue; | |
1da177e4 | 714 | /* Unbind so it can run. */ |
89ada679 | 715 | kthread_bind(per_cpu_ptr(wq->cpu_wq, hotcpu)->thread, |
a4c4af7c | 716 | any_online_cpu(cpu_online_map)); |
1da177e4 LT |
717 | cleanup_workqueue_thread(wq, hotcpu); |
718 | } | |
9b41ea72 AM |
719 | mutex_unlock(&workqueue_mutex); |
720 | break; | |
721 | ||
722 | case CPU_DOWN_PREPARE: | |
723 | mutex_lock(&workqueue_mutex); | |
724 | break; | |
725 | ||
726 | case CPU_DOWN_FAILED: | |
727 | mutex_unlock(&workqueue_mutex); | |
1da177e4 LT |
728 | break; |
729 | ||
730 | case CPU_DEAD: | |
731 | list_for_each_entry(wq, &workqueues, list) | |
732 | cleanup_workqueue_thread(wq, hotcpu); | |
733 | list_for_each_entry(wq, &workqueues, list) | |
734 | take_over_work(wq, hotcpu); | |
9b41ea72 | 735 | mutex_unlock(&workqueue_mutex); |
1da177e4 LT |
736 | break; |
737 | } | |
738 | ||
739 | return NOTIFY_OK; | |
740 | } | |
741 | #endif | |
742 | ||
743 | void init_workqueues(void) | |
744 | { | |
f756d5e2 | 745 | singlethread_cpu = first_cpu(cpu_possible_map); |
1da177e4 LT |
746 | hotcpu_notifier(workqueue_cpu_callback, 0); |
747 | keventd_wq = create_workqueue("events"); | |
748 | BUG_ON(!keventd_wq); | |
749 | } | |
750 |