Commit | Line | Data |
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8b712842 CM |
1 | /* |
2 | * Copyright (C) 2007 Oracle. All rights reserved. | |
3 | * | |
4 | * This program is free software; you can redistribute it and/or | |
5 | * modify it under the terms of the GNU General Public | |
6 | * License v2 as published by the Free Software Foundation. | |
7 | * | |
8 | * This program is distributed in the hope that it will be useful, | |
9 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
10 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
11 | * General Public License for more details. | |
12 | * | |
13 | * You should have received a copy of the GNU General Public | |
14 | * License along with this program; if not, write to the | |
15 | * Free Software Foundation, Inc., 59 Temple Place - Suite 330, | |
16 | * Boston, MA 021110-1307, USA. | |
17 | */ | |
18 | ||
19 | #include <linux/kthread.h> | |
20 | #include <linux/list.h> | |
21 | #include <linux/spinlock.h> | |
b51912c9 | 22 | #include <linux/freezer.h> |
8b712842 CM |
23 | #include "async-thread.h" |
24 | ||
4a69a410 CM |
25 | #define WORK_QUEUED_BIT 0 |
26 | #define WORK_DONE_BIT 1 | |
27 | #define WORK_ORDER_DONE_BIT 2 | |
d313d7a3 | 28 | #define WORK_HIGH_PRIO_BIT 3 |
4a69a410 | 29 | |
8b712842 CM |
30 | /* |
31 | * container for the kthread task pointer and the list of pending work | |
32 | * One of these is allocated per thread. | |
33 | */ | |
34 | struct btrfs_worker_thread { | |
35d8ba66 CM |
35 | /* pool we belong to */ |
36 | struct btrfs_workers *workers; | |
37 | ||
8b712842 CM |
38 | /* list of struct btrfs_work that are waiting for service */ |
39 | struct list_head pending; | |
d313d7a3 | 40 | struct list_head prio_pending; |
8b712842 CM |
41 | |
42 | /* list of worker threads from struct btrfs_workers */ | |
43 | struct list_head worker_list; | |
44 | ||
45 | /* kthread */ | |
46 | struct task_struct *task; | |
47 | ||
48 | /* number of things on the pending list */ | |
49 | atomic_t num_pending; | |
53863232 | 50 | |
9042846b CM |
51 | /* reference counter for this struct */ |
52 | atomic_t refs; | |
53 | ||
4854ddd0 | 54 | unsigned long sequence; |
8b712842 CM |
55 | |
56 | /* protects the pending list. */ | |
57 | spinlock_t lock; | |
58 | ||
59 | /* set to non-zero when this thread is already awake and kicking */ | |
60 | int working; | |
35d8ba66 CM |
61 | |
62 | /* are we currently idle */ | |
63 | int idle; | |
8b712842 CM |
64 | }; |
65 | ||
35d8ba66 CM |
66 | /* |
67 | * helper function to move a thread onto the idle list after it | |
68 | * has finished some requests. | |
69 | */ | |
70 | static void check_idle_worker(struct btrfs_worker_thread *worker) | |
71 | { | |
72 | if (!worker->idle && atomic_read(&worker->num_pending) < | |
73 | worker->workers->idle_thresh / 2) { | |
74 | unsigned long flags; | |
75 | spin_lock_irqsave(&worker->workers->lock, flags); | |
76 | worker->idle = 1; | |
3e99d8eb CM |
77 | |
78 | /* the list may be empty if the worker is just starting */ | |
79 | if (!list_empty(&worker->worker_list)) { | |
80 | list_move(&worker->worker_list, | |
81 | &worker->workers->idle_list); | |
82 | } | |
35d8ba66 CM |
83 | spin_unlock_irqrestore(&worker->workers->lock, flags); |
84 | } | |
85 | } | |
86 | ||
87 | /* | |
88 | * helper function to move a thread off the idle list after new | |
89 | * pending work is added. | |
90 | */ | |
91 | static void check_busy_worker(struct btrfs_worker_thread *worker) | |
92 | { | |
93 | if (worker->idle && atomic_read(&worker->num_pending) >= | |
94 | worker->workers->idle_thresh) { | |
95 | unsigned long flags; | |
96 | spin_lock_irqsave(&worker->workers->lock, flags); | |
97 | worker->idle = 0; | |
3e99d8eb CM |
98 | |
99 | if (!list_empty(&worker->worker_list)) { | |
100 | list_move_tail(&worker->worker_list, | |
101 | &worker->workers->worker_list); | |
102 | } | |
35d8ba66 CM |
103 | spin_unlock_irqrestore(&worker->workers->lock, flags); |
104 | } | |
105 | } | |
106 | ||
9042846b CM |
107 | static void check_pending_worker_creates(struct btrfs_worker_thread *worker) |
108 | { | |
109 | struct btrfs_workers *workers = worker->workers; | |
110 | unsigned long flags; | |
111 | ||
112 | rmb(); | |
113 | if (!workers->atomic_start_pending) | |
114 | return; | |
115 | ||
116 | spin_lock_irqsave(&workers->lock, flags); | |
117 | if (!workers->atomic_start_pending) | |
118 | goto out; | |
119 | ||
120 | workers->atomic_start_pending = 0; | |
121 | if (workers->num_workers >= workers->max_workers) | |
122 | goto out; | |
123 | ||
124 | spin_unlock_irqrestore(&workers->lock, flags); | |
125 | btrfs_start_workers(workers, 1); | |
126 | return; | |
127 | ||
128 | out: | |
129 | spin_unlock_irqrestore(&workers->lock, flags); | |
130 | } | |
131 | ||
4a69a410 CM |
132 | static noinline int run_ordered_completions(struct btrfs_workers *workers, |
133 | struct btrfs_work *work) | |
134 | { | |
4a69a410 CM |
135 | if (!workers->ordered) |
136 | return 0; | |
137 | ||
138 | set_bit(WORK_DONE_BIT, &work->flags); | |
139 | ||
4e3f9c50 | 140 | spin_lock(&workers->order_lock); |
4a69a410 | 141 | |
d313d7a3 CM |
142 | while (1) { |
143 | if (!list_empty(&workers->prio_order_list)) { | |
144 | work = list_entry(workers->prio_order_list.next, | |
145 | struct btrfs_work, order_list); | |
146 | } else if (!list_empty(&workers->order_list)) { | |
147 | work = list_entry(workers->order_list.next, | |
148 | struct btrfs_work, order_list); | |
149 | } else { | |
150 | break; | |
151 | } | |
4a69a410 CM |
152 | if (!test_bit(WORK_DONE_BIT, &work->flags)) |
153 | break; | |
154 | ||
155 | /* we are going to call the ordered done function, but | |
156 | * we leave the work item on the list as a barrier so | |
157 | * that later work items that are done don't have their | |
158 | * functions called before this one returns | |
159 | */ | |
160 | if (test_and_set_bit(WORK_ORDER_DONE_BIT, &work->flags)) | |
161 | break; | |
162 | ||
4e3f9c50 | 163 | spin_unlock(&workers->order_lock); |
4a69a410 CM |
164 | |
165 | work->ordered_func(work); | |
166 | ||
167 | /* now take the lock again and call the freeing code */ | |
4e3f9c50 | 168 | spin_lock(&workers->order_lock); |
4a69a410 CM |
169 | list_del(&work->order_list); |
170 | work->ordered_free(work); | |
171 | } | |
172 | ||
4e3f9c50 | 173 | spin_unlock(&workers->order_lock); |
4a69a410 CM |
174 | return 0; |
175 | } | |
176 | ||
9042846b CM |
177 | static void put_worker(struct btrfs_worker_thread *worker) |
178 | { | |
179 | if (atomic_dec_and_test(&worker->refs)) | |
180 | kfree(worker); | |
181 | } | |
182 | ||
183 | static int try_worker_shutdown(struct btrfs_worker_thread *worker) | |
184 | { | |
185 | int freeit = 0; | |
186 | ||
187 | spin_lock_irq(&worker->lock); | |
627e421a | 188 | spin_lock(&worker->workers->lock); |
9042846b CM |
189 | if (worker->workers->num_workers > 1 && |
190 | worker->idle && | |
191 | !worker->working && | |
192 | !list_empty(&worker->worker_list) && | |
193 | list_empty(&worker->prio_pending) && | |
6e74057c CM |
194 | list_empty(&worker->pending) && |
195 | atomic_read(&worker->num_pending) == 0) { | |
9042846b CM |
196 | freeit = 1; |
197 | list_del_init(&worker->worker_list); | |
198 | worker->workers->num_workers--; | |
199 | } | |
627e421a | 200 | spin_unlock(&worker->workers->lock); |
9042846b CM |
201 | spin_unlock_irq(&worker->lock); |
202 | ||
203 | if (freeit) | |
204 | put_worker(worker); | |
205 | return freeit; | |
206 | } | |
207 | ||
4f878e84 CM |
208 | static struct btrfs_work *get_next_work(struct btrfs_worker_thread *worker, |
209 | struct list_head *prio_head, | |
210 | struct list_head *head) | |
211 | { | |
212 | struct btrfs_work *work = NULL; | |
213 | struct list_head *cur = NULL; | |
214 | ||
215 | if(!list_empty(prio_head)) | |
216 | cur = prio_head->next; | |
217 | ||
218 | smp_mb(); | |
219 | if (!list_empty(&worker->prio_pending)) | |
220 | goto refill; | |
221 | ||
222 | if (!list_empty(head)) | |
223 | cur = head->next; | |
224 | ||
225 | if (cur) | |
226 | goto out; | |
227 | ||
228 | refill: | |
229 | spin_lock_irq(&worker->lock); | |
230 | list_splice_tail_init(&worker->prio_pending, prio_head); | |
231 | list_splice_tail_init(&worker->pending, head); | |
232 | ||
233 | if (!list_empty(prio_head)) | |
234 | cur = prio_head->next; | |
235 | else if (!list_empty(head)) | |
236 | cur = head->next; | |
237 | spin_unlock_irq(&worker->lock); | |
238 | ||
239 | if (!cur) | |
240 | goto out_fail; | |
241 | ||
242 | out: | |
243 | work = list_entry(cur, struct btrfs_work, list); | |
244 | ||
245 | out_fail: | |
246 | return work; | |
247 | } | |
248 | ||
8b712842 CM |
249 | /* |
250 | * main loop for servicing work items | |
251 | */ | |
252 | static int worker_loop(void *arg) | |
253 | { | |
254 | struct btrfs_worker_thread *worker = arg; | |
4f878e84 CM |
255 | struct list_head head; |
256 | struct list_head prio_head; | |
8b712842 | 257 | struct btrfs_work *work; |
4f878e84 CM |
258 | |
259 | INIT_LIST_HEAD(&head); | |
260 | INIT_LIST_HEAD(&prio_head); | |
261 | ||
8b712842 | 262 | do { |
4f878e84 | 263 | again: |
d313d7a3 | 264 | while (1) { |
4f878e84 CM |
265 | |
266 | ||
267 | work = get_next_work(worker, &prio_head, &head); | |
268 | if (!work) | |
d313d7a3 CM |
269 | break; |
270 | ||
8b712842 | 271 | list_del(&work->list); |
4a69a410 | 272 | clear_bit(WORK_QUEUED_BIT, &work->flags); |
8b712842 CM |
273 | |
274 | work->worker = worker; | |
8b712842 CM |
275 | |
276 | work->func(work); | |
277 | ||
278 | atomic_dec(&worker->num_pending); | |
4a69a410 CM |
279 | /* |
280 | * unless this is an ordered work queue, | |
281 | * 'work' was probably freed by func above. | |
282 | */ | |
283 | run_ordered_completions(worker->workers, work); | |
284 | ||
9042846b CM |
285 | check_pending_worker_creates(worker); |
286 | ||
8b712842 | 287 | } |
4f878e84 CM |
288 | |
289 | spin_lock_irq(&worker->lock); | |
290 | check_idle_worker(worker); | |
291 | ||
8b712842 | 292 | if (freezing(current)) { |
b51912c9 CM |
293 | worker->working = 0; |
294 | spin_unlock_irq(&worker->lock); | |
8b712842 CM |
295 | refrigerator(); |
296 | } else { | |
8b712842 | 297 | spin_unlock_irq(&worker->lock); |
b51912c9 CM |
298 | if (!kthread_should_stop()) { |
299 | cpu_relax(); | |
300 | /* | |
301 | * we've dropped the lock, did someone else | |
302 | * jump_in? | |
303 | */ | |
304 | smp_mb(); | |
d313d7a3 CM |
305 | if (!list_empty(&worker->pending) || |
306 | !list_empty(&worker->prio_pending)) | |
b51912c9 CM |
307 | continue; |
308 | ||
309 | /* | |
310 | * this short schedule allows more work to | |
311 | * come in without the queue functions | |
312 | * needing to go through wake_up_process() | |
313 | * | |
314 | * worker->working is still 1, so nobody | |
315 | * is going to try and wake us up | |
316 | */ | |
317 | schedule_timeout(1); | |
318 | smp_mb(); | |
d313d7a3 CM |
319 | if (!list_empty(&worker->pending) || |
320 | !list_empty(&worker->prio_pending)) | |
b51912c9 CM |
321 | continue; |
322 | ||
b5555f77 AG |
323 | if (kthread_should_stop()) |
324 | break; | |
325 | ||
b51912c9 CM |
326 | /* still no more work?, sleep for real */ |
327 | spin_lock_irq(&worker->lock); | |
328 | set_current_state(TASK_INTERRUPTIBLE); | |
d313d7a3 | 329 | if (!list_empty(&worker->pending) || |
4f878e84 CM |
330 | !list_empty(&worker->prio_pending)) { |
331 | spin_unlock_irq(&worker->lock); | |
332 | goto again; | |
333 | } | |
b51912c9 CM |
334 | |
335 | /* | |
336 | * this makes sure we get a wakeup when someone | |
337 | * adds something new to the queue | |
338 | */ | |
339 | worker->working = 0; | |
340 | spin_unlock_irq(&worker->lock); | |
341 | ||
9042846b CM |
342 | if (!kthread_should_stop()) { |
343 | schedule_timeout(HZ * 120); | |
344 | if (!worker->working && | |
345 | try_worker_shutdown(worker)) { | |
346 | return 0; | |
347 | } | |
348 | } | |
b51912c9 | 349 | } |
8b712842 CM |
350 | __set_current_state(TASK_RUNNING); |
351 | } | |
352 | } while (!kthread_should_stop()); | |
353 | return 0; | |
354 | } | |
355 | ||
356 | /* | |
357 | * this will wait for all the worker threads to shutdown | |
358 | */ | |
359 | int btrfs_stop_workers(struct btrfs_workers *workers) | |
360 | { | |
361 | struct list_head *cur; | |
362 | struct btrfs_worker_thread *worker; | |
9042846b | 363 | int can_stop; |
8b712842 | 364 | |
9042846b | 365 | spin_lock_irq(&workers->lock); |
35d8ba66 | 366 | list_splice_init(&workers->idle_list, &workers->worker_list); |
d397712b | 367 | while (!list_empty(&workers->worker_list)) { |
8b712842 CM |
368 | cur = workers->worker_list.next; |
369 | worker = list_entry(cur, struct btrfs_worker_thread, | |
370 | worker_list); | |
9042846b CM |
371 | |
372 | atomic_inc(&worker->refs); | |
373 | workers->num_workers -= 1; | |
374 | if (!list_empty(&worker->worker_list)) { | |
375 | list_del_init(&worker->worker_list); | |
376 | put_worker(worker); | |
377 | can_stop = 1; | |
378 | } else | |
379 | can_stop = 0; | |
380 | spin_unlock_irq(&workers->lock); | |
381 | if (can_stop) | |
382 | kthread_stop(worker->task); | |
383 | spin_lock_irq(&workers->lock); | |
384 | put_worker(worker); | |
8b712842 | 385 | } |
9042846b | 386 | spin_unlock_irq(&workers->lock); |
8b712842 CM |
387 | return 0; |
388 | } | |
389 | ||
390 | /* | |
391 | * simple init on struct btrfs_workers | |
392 | */ | |
5443be45 | 393 | void btrfs_init_workers(struct btrfs_workers *workers, char *name, int max) |
8b712842 CM |
394 | { |
395 | workers->num_workers = 0; | |
396 | INIT_LIST_HEAD(&workers->worker_list); | |
35d8ba66 | 397 | INIT_LIST_HEAD(&workers->idle_list); |
4a69a410 | 398 | INIT_LIST_HEAD(&workers->order_list); |
d313d7a3 | 399 | INIT_LIST_HEAD(&workers->prio_order_list); |
8b712842 | 400 | spin_lock_init(&workers->lock); |
4e3f9c50 | 401 | spin_lock_init(&workers->order_lock); |
8b712842 | 402 | workers->max_workers = max; |
61b49440 | 403 | workers->idle_thresh = 32; |
5443be45 | 404 | workers->name = name; |
4a69a410 | 405 | workers->ordered = 0; |
9042846b CM |
406 | workers->atomic_start_pending = 0; |
407 | workers->atomic_worker_start = 0; | |
8b712842 CM |
408 | } |
409 | ||
410 | /* | |
411 | * starts new worker threads. This does not enforce the max worker | |
412 | * count in case you need to temporarily go past it. | |
413 | */ | |
414 | int btrfs_start_workers(struct btrfs_workers *workers, int num_workers) | |
415 | { | |
416 | struct btrfs_worker_thread *worker; | |
417 | int ret = 0; | |
418 | int i; | |
419 | ||
420 | for (i = 0; i < num_workers; i++) { | |
421 | worker = kzalloc(sizeof(*worker), GFP_NOFS); | |
422 | if (!worker) { | |
423 | ret = -ENOMEM; | |
424 | goto fail; | |
425 | } | |
426 | ||
427 | INIT_LIST_HEAD(&worker->pending); | |
d313d7a3 | 428 | INIT_LIST_HEAD(&worker->prio_pending); |
8b712842 CM |
429 | INIT_LIST_HEAD(&worker->worker_list); |
430 | spin_lock_init(&worker->lock); | |
4e3f9c50 | 431 | |
8b712842 | 432 | atomic_set(&worker->num_pending, 0); |
9042846b | 433 | atomic_set(&worker->refs, 1); |
fd0fb038 | 434 | worker->workers = workers; |
5443be45 CM |
435 | worker->task = kthread_run(worker_loop, worker, |
436 | "btrfs-%s-%d", workers->name, | |
437 | workers->num_workers + i); | |
8b712842 CM |
438 | if (IS_ERR(worker->task)) { |
439 | ret = PTR_ERR(worker->task); | |
9b627e9b | 440 | kfree(worker); |
8b712842 CM |
441 | goto fail; |
442 | } | |
8b712842 | 443 | spin_lock_irq(&workers->lock); |
35d8ba66 | 444 | list_add_tail(&worker->worker_list, &workers->idle_list); |
4854ddd0 | 445 | worker->idle = 1; |
8b712842 CM |
446 | workers->num_workers++; |
447 | spin_unlock_irq(&workers->lock); | |
448 | } | |
449 | return 0; | |
450 | fail: | |
451 | btrfs_stop_workers(workers); | |
452 | return ret; | |
453 | } | |
454 | ||
455 | /* | |
456 | * run through the list and find a worker thread that doesn't have a lot | |
457 | * to do right now. This can return null if we aren't yet at the thread | |
458 | * count limit and all of the threads are busy. | |
459 | */ | |
460 | static struct btrfs_worker_thread *next_worker(struct btrfs_workers *workers) | |
461 | { | |
462 | struct btrfs_worker_thread *worker; | |
463 | struct list_head *next; | |
8b712842 CM |
464 | int enforce_min = workers->num_workers < workers->max_workers; |
465 | ||
8b712842 | 466 | /* |
35d8ba66 CM |
467 | * if we find an idle thread, don't move it to the end of the |
468 | * idle list. This improves the chance that the next submission | |
469 | * will reuse the same thread, and maybe catch it while it is still | |
470 | * working | |
8b712842 | 471 | */ |
35d8ba66 CM |
472 | if (!list_empty(&workers->idle_list)) { |
473 | next = workers->idle_list.next; | |
8b712842 CM |
474 | worker = list_entry(next, struct btrfs_worker_thread, |
475 | worker_list); | |
35d8ba66 | 476 | return worker; |
8b712842 | 477 | } |
35d8ba66 CM |
478 | if (enforce_min || list_empty(&workers->worker_list)) |
479 | return NULL; | |
480 | ||
8b712842 | 481 | /* |
35d8ba66 | 482 | * if we pick a busy task, move the task to the end of the list. |
d352ac68 CM |
483 | * hopefully this will keep things somewhat evenly balanced. |
484 | * Do the move in batches based on the sequence number. This groups | |
485 | * requests submitted at roughly the same time onto the same worker. | |
8b712842 | 486 | */ |
35d8ba66 CM |
487 | next = workers->worker_list.next; |
488 | worker = list_entry(next, struct btrfs_worker_thread, worker_list); | |
4854ddd0 | 489 | worker->sequence++; |
d352ac68 | 490 | |
53863232 | 491 | if (worker->sequence % workers->idle_thresh == 0) |
4854ddd0 | 492 | list_move_tail(next, &workers->worker_list); |
8b712842 CM |
493 | return worker; |
494 | } | |
495 | ||
d352ac68 CM |
496 | /* |
497 | * selects a worker thread to take the next job. This will either find | |
498 | * an idle worker, start a new worker up to the max count, or just return | |
499 | * one of the existing busy workers. | |
500 | */ | |
8b712842 CM |
501 | static struct btrfs_worker_thread *find_worker(struct btrfs_workers *workers) |
502 | { | |
503 | struct btrfs_worker_thread *worker; | |
504 | unsigned long flags; | |
9042846b | 505 | struct list_head *fallback; |
8b712842 CM |
506 | |
507 | again: | |
508 | spin_lock_irqsave(&workers->lock, flags); | |
509 | worker = next_worker(workers); | |
8b712842 CM |
510 | |
511 | if (!worker) { | |
8b712842 | 512 | if (workers->num_workers >= workers->max_workers) { |
9042846b CM |
513 | goto fallback; |
514 | } else if (workers->atomic_worker_start) { | |
515 | workers->atomic_start_pending = 1; | |
516 | goto fallback; | |
8b712842 CM |
517 | } else { |
518 | spin_unlock_irqrestore(&workers->lock, flags); | |
519 | /* we're below the limit, start another worker */ | |
520 | btrfs_start_workers(workers, 1); | |
521 | goto again; | |
522 | } | |
523 | } | |
6e74057c | 524 | goto found; |
9042846b CM |
525 | |
526 | fallback: | |
527 | fallback = NULL; | |
528 | /* | |
529 | * we have failed to find any workers, just | |
530 | * return the first one we can find. | |
531 | */ | |
532 | if (!list_empty(&workers->worker_list)) | |
533 | fallback = workers->worker_list.next; | |
534 | if (!list_empty(&workers->idle_list)) | |
535 | fallback = workers->idle_list.next; | |
536 | BUG_ON(!fallback); | |
537 | worker = list_entry(fallback, | |
538 | struct btrfs_worker_thread, worker_list); | |
6e74057c CM |
539 | found: |
540 | /* | |
541 | * this makes sure the worker doesn't exit before it is placed | |
542 | * onto a busy/idle list | |
543 | */ | |
544 | atomic_inc(&worker->num_pending); | |
9042846b CM |
545 | spin_unlock_irqrestore(&workers->lock, flags); |
546 | return worker; | |
8b712842 CM |
547 | } |
548 | ||
549 | /* | |
550 | * btrfs_requeue_work just puts the work item back on the tail of the list | |
551 | * it was taken from. It is intended for use with long running work functions | |
552 | * that make some progress and want to give the cpu up for others. | |
553 | */ | |
554 | int btrfs_requeue_work(struct btrfs_work *work) | |
555 | { | |
556 | struct btrfs_worker_thread *worker = work->worker; | |
557 | unsigned long flags; | |
a6837051 | 558 | int wake = 0; |
8b712842 | 559 | |
4a69a410 | 560 | if (test_and_set_bit(WORK_QUEUED_BIT, &work->flags)) |
8b712842 CM |
561 | goto out; |
562 | ||
563 | spin_lock_irqsave(&worker->lock, flags); | |
d313d7a3 CM |
564 | if (test_bit(WORK_HIGH_PRIO_BIT, &work->flags)) |
565 | list_add_tail(&work->list, &worker->prio_pending); | |
566 | else | |
567 | list_add_tail(&work->list, &worker->pending); | |
b51912c9 | 568 | atomic_inc(&worker->num_pending); |
75ccf47d CM |
569 | |
570 | /* by definition we're busy, take ourselves off the idle | |
571 | * list | |
572 | */ | |
573 | if (worker->idle) { | |
29c5e8ce | 574 | spin_lock(&worker->workers->lock); |
75ccf47d CM |
575 | worker->idle = 0; |
576 | list_move_tail(&worker->worker_list, | |
6e74057c | 577 | &worker->workers->worker_list); |
29c5e8ce | 578 | spin_unlock(&worker->workers->lock); |
75ccf47d | 579 | } |
a6837051 CM |
580 | if (!worker->working) { |
581 | wake = 1; | |
582 | worker->working = 1; | |
583 | } | |
75ccf47d | 584 | |
a6837051 CM |
585 | if (wake) |
586 | wake_up_process(worker->task); | |
9042846b | 587 | spin_unlock_irqrestore(&worker->lock, flags); |
8b712842 | 588 | out: |
a6837051 | 589 | |
8b712842 CM |
590 | return 0; |
591 | } | |
592 | ||
d313d7a3 CM |
593 | void btrfs_set_work_high_prio(struct btrfs_work *work) |
594 | { | |
595 | set_bit(WORK_HIGH_PRIO_BIT, &work->flags); | |
596 | } | |
597 | ||
8b712842 CM |
598 | /* |
599 | * places a struct btrfs_work into the pending queue of one of the kthreads | |
600 | */ | |
601 | int btrfs_queue_worker(struct btrfs_workers *workers, struct btrfs_work *work) | |
602 | { | |
603 | struct btrfs_worker_thread *worker; | |
604 | unsigned long flags; | |
605 | int wake = 0; | |
606 | ||
607 | /* don't requeue something already on a list */ | |
4a69a410 | 608 | if (test_and_set_bit(WORK_QUEUED_BIT, &work->flags)) |
8b712842 CM |
609 | goto out; |
610 | ||
611 | worker = find_worker(workers); | |
4a69a410 | 612 | if (workers->ordered) { |
4e3f9c50 CM |
613 | /* |
614 | * you're not allowed to do ordered queues from an | |
615 | * interrupt handler | |
616 | */ | |
617 | spin_lock(&workers->order_lock); | |
d313d7a3 CM |
618 | if (test_bit(WORK_HIGH_PRIO_BIT, &work->flags)) { |
619 | list_add_tail(&work->order_list, | |
620 | &workers->prio_order_list); | |
621 | } else { | |
622 | list_add_tail(&work->order_list, &workers->order_list); | |
623 | } | |
4e3f9c50 | 624 | spin_unlock(&workers->order_lock); |
4a69a410 CM |
625 | } else { |
626 | INIT_LIST_HEAD(&work->order_list); | |
627 | } | |
8b712842 CM |
628 | |
629 | spin_lock_irqsave(&worker->lock, flags); | |
a6837051 | 630 | |
d313d7a3 CM |
631 | if (test_bit(WORK_HIGH_PRIO_BIT, &work->flags)) |
632 | list_add_tail(&work->list, &worker->prio_pending); | |
633 | else | |
634 | list_add_tail(&work->list, &worker->pending); | |
35d8ba66 | 635 | check_busy_worker(worker); |
8b712842 CM |
636 | |
637 | /* | |
638 | * avoid calling into wake_up_process if this thread has already | |
639 | * been kicked | |
640 | */ | |
641 | if (!worker->working) | |
642 | wake = 1; | |
643 | worker->working = 1; | |
644 | ||
8b712842 CM |
645 | if (wake) |
646 | wake_up_process(worker->task); | |
9042846b CM |
647 | spin_unlock_irqrestore(&worker->lock, flags); |
648 | ||
8b712842 CM |
649 | out: |
650 | return 0; | |
651 | } |