]>
Commit | Line | Data |
---|---|---|
715f6251 | 1 | /* |
2 | * This file is part of the SPL: Solaris Porting Layer. | |
3 | * | |
4 | * Copyright (c) 2008 Lawrence Livermore National Security, LLC. | |
5 | * Produced at Lawrence Livermore National Laboratory | |
6 | * Written by: | |
7 | * Brian Behlendorf <behlendorf1@llnl.gov>, | |
8 | * Herb Wartens <wartens2@llnl.gov>, | |
9 | * Jim Garlick <garlick@llnl.gov> | |
10 | * UCRL-CODE-235197 | |
11 | * | |
12 | * This is free software; you can redistribute it and/or modify it | |
13 | * under the terms of the GNU General Public License as published by | |
14 | * the Free Software Foundation; either version 2 of the License, or | |
15 | * (at your option) any later version. | |
16 | * | |
17 | * This is distributed in the hope that it will be useful, but WITHOUT | |
18 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
19 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | |
20 | * for more details. | |
21 | * | |
22 | * You should have received a copy of the GNU General Public License along | |
23 | * with this program; if not, write to the Free Software Foundation, Inc., | |
24 | * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. | |
25 | */ | |
26 | ||
f4b37741 | 27 | #include <sys/taskq.h> |
3d061e9d | 28 | #include <sys/kmem.h> |
f1ca4da6 | 29 | |
937879f1 | 30 | #ifdef DEBUG_SUBSYSTEM |
31 | #undef DEBUG_SUBSYSTEM | |
32 | #endif | |
33 | ||
34 | #define DEBUG_SUBSYSTEM S_TASKQ | |
35 | ||
e9cb2b4f BB |
36 | /* Global system-wide dynamic task queue available for all consumers */ |
37 | taskq_t *system_taskq; | |
38 | EXPORT_SYMBOL(system_taskq); | |
39 | ||
3d061e9d | 40 | typedef struct spl_task { |
41 | spinlock_t t_lock; | |
42 | struct list_head t_list; | |
43 | taskqid_t t_id; | |
44 | task_func_t *t_func; | |
45 | void *t_arg; | |
46 | } spl_task_t; | |
47 | ||
bcd68186 | 48 | /* NOTE: Must be called with tq->tq_lock held, returns a list_t which |
49 | * is not attached to the free, work, or pending taskq lists. | |
f1ca4da6 | 50 | */ |
3d061e9d | 51 | static spl_task_t * |
bcd68186 | 52 | task_alloc(taskq_t *tq, uint_t flags) |
53 | { | |
3d061e9d | 54 | spl_task_t *t; |
bcd68186 | 55 | int count = 0; |
56 | ENTRY; | |
57 | ||
58 | ASSERT(tq); | |
59 | ASSERT(flags & (TQ_SLEEP | TQ_NOSLEEP)); /* One set */ | |
60 | ASSERT(!((flags & TQ_SLEEP) && (flags & TQ_NOSLEEP))); /* Not both */ | |
3d061e9d | 61 | ASSERT(spin_is_locked(&tq->tq_lock)); |
bcd68186 | 62 | retry: |
3d061e9d | 63 | /* Aquire spl_task_t's from free list if available */ |
bcd68186 | 64 | if (!list_empty(&tq->tq_free_list) && !(flags & TQ_NEW)) { |
3d061e9d | 65 | t = list_entry(tq->tq_free_list.next, spl_task_t, t_list); |
66 | list_del_init(&t->t_list); | |
67 | RETURN(t); | |
bcd68186 | 68 | } |
69 | ||
70 | /* Free list is empty and memory allocs are prohibited */ | |
71 | if (flags & TQ_NOALLOC) | |
72 | RETURN(NULL); | |
73 | ||
3d061e9d | 74 | /* Hit maximum spl_task_t pool size */ |
bcd68186 | 75 | if (tq->tq_nalloc >= tq->tq_maxalloc) { |
76 | if (flags & TQ_NOSLEEP) | |
77 | RETURN(NULL); | |
78 | ||
79 | /* Sleep periodically polling the free list for an available | |
3d061e9d | 80 | * spl_task_t. If a full second passes and we have not found |
bcd68186 | 81 | * one gives up and return a NULL to the caller. */ |
82 | if (flags & TQ_SLEEP) { | |
749045bb | 83 | spin_unlock_irqrestore(&tq->tq_lock, tq->tq_lock_flags); |
bcd68186 | 84 | schedule_timeout(HZ / 100); |
749045bb | 85 | spin_lock_irqsave(&tq->tq_lock, tq->tq_lock_flags); |
bcd68186 | 86 | if (count < 100) |
87 | GOTO(retry, count++); | |
88 | ||
89 | RETURN(NULL); | |
90 | } | |
91 | ||
92 | /* Unreachable, TQ_SLEEP xor TQ_NOSLEEP */ | |
93 | SBUG(); | |
94 | } | |
95 | ||
749045bb | 96 | spin_unlock_irqrestore(&tq->tq_lock, tq->tq_lock_flags); |
3d061e9d | 97 | t = kmem_alloc(sizeof(spl_task_t), flags & (TQ_SLEEP | TQ_NOSLEEP)); |
749045bb | 98 | spin_lock_irqsave(&tq->tq_lock, tq->tq_lock_flags); |
bcd68186 | 99 | |
100 | if (t) { | |
101 | spin_lock_init(&t->t_lock); | |
102 | INIT_LIST_HEAD(&t->t_list); | |
103 | t->t_id = 0; | |
104 | t->t_func = NULL; | |
105 | t->t_arg = NULL; | |
106 | tq->tq_nalloc++; | |
107 | } | |
108 | ||
109 | RETURN(t); | |
110 | } | |
111 | ||
3d061e9d | 112 | /* NOTE: Must be called with tq->tq_lock held, expectes the spl_task_t |
bcd68186 | 113 | * to already be removed from the free, work, or pending taskq lists. |
114 | */ | |
115 | static void | |
3d061e9d | 116 | task_free(taskq_t *tq, spl_task_t *t) |
bcd68186 | 117 | { |
118 | ENTRY; | |
119 | ||
120 | ASSERT(tq); | |
121 | ASSERT(t); | |
122 | ASSERT(spin_is_locked(&tq->tq_lock)); | |
123 | ASSERT(list_empty(&t->t_list)); | |
124 | ||
3d061e9d | 125 | kmem_free(t, sizeof(spl_task_t)); |
bcd68186 | 126 | tq->tq_nalloc--; |
f1ca4da6 | 127 | |
bcd68186 | 128 | EXIT; |
129 | } | |
130 | ||
131 | /* NOTE: Must be called with tq->tq_lock held, either destroyes the | |
3d061e9d | 132 | * spl_task_t if too many exist or moves it to the free list for later use. |
bcd68186 | 133 | */ |
f1ca4da6 | 134 | static void |
3d061e9d | 135 | task_done(taskq_t *tq, spl_task_t *t) |
f1ca4da6 | 136 | { |
bcd68186 | 137 | ENTRY; |
138 | ASSERT(tq); | |
139 | ASSERT(t); | |
140 | ASSERT(spin_is_locked(&tq->tq_lock)); | |
141 | ||
142 | list_del_init(&t->t_list); | |
f1ca4da6 | 143 | |
bcd68186 | 144 | if (tq->tq_nalloc <= tq->tq_minalloc) { |
145 | t->t_id = 0; | |
146 | t->t_func = NULL; | |
147 | t->t_arg = NULL; | |
9ab1ac14 | 148 | list_add_tail(&t->t_list, &tq->tq_free_list); |
bcd68186 | 149 | } else { |
150 | task_free(tq, t); | |
151 | } | |
f1ca4da6 | 152 | |
bcd68186 | 153 | EXIT; |
f1ca4da6 | 154 | } |
155 | ||
bcd68186 | 156 | /* Taskqid's are handed out in a monotonically increasing fashion per |
157 | * taskq_t. We don't handle taskqid wrapping yet, but fortuntely it isi | |
158 | * a 64-bit value so this is probably never going to happen. The lowest | |
159 | * pending taskqid is stored in the taskq_t to make it easy for any | |
160 | * taskq_wait()'ers to know if the tasks they're waiting for have | |
161 | * completed. Unfortunately, tq_task_lowest is kept up to date is | |
162 | * a pretty brain dead way, something more clever should be done. | |
163 | */ | |
164 | static int | |
165 | taskq_wait_check(taskq_t *tq, taskqid_t id) | |
166 | { | |
167 | RETURN(tq->tq_lowest_id >= id); | |
168 | } | |
169 | ||
170 | /* Expected to wait for all previously scheduled tasks to complete. We do | |
171 | * not need to wait for tasked scheduled after this call to complete. In | |
172 | * otherwords we do not need to drain the entire taskq. */ | |
173 | void | |
174 | __taskq_wait_id(taskq_t *tq, taskqid_t id) | |
f1ca4da6 | 175 | { |
937879f1 | 176 | ENTRY; |
bcd68186 | 177 | ASSERT(tq); |
178 | ||
179 | wait_event(tq->tq_wait_waitq, taskq_wait_check(tq, id)); | |
180 | ||
181 | EXIT; | |
182 | } | |
183 | EXPORT_SYMBOL(__taskq_wait_id); | |
184 | ||
185 | void | |
186 | __taskq_wait(taskq_t *tq) | |
187 | { | |
188 | taskqid_t id; | |
189 | ENTRY; | |
190 | ASSERT(tq); | |
191 | ||
749045bb | 192 | spin_lock_irqsave(&tq->tq_lock, tq->tq_lock_flags); |
bcd68186 | 193 | id = tq->tq_next_id; |
749045bb | 194 | spin_unlock_irqrestore(&tq->tq_lock, tq->tq_lock_flags); |
bcd68186 | 195 | |
196 | __taskq_wait_id(tq, id); | |
197 | ||
198 | EXIT; | |
199 | ||
200 | } | |
201 | EXPORT_SYMBOL(__taskq_wait); | |
202 | ||
203 | int | |
204 | __taskq_member(taskq_t *tq, void *t) | |
205 | { | |
206 | int i; | |
207 | ENTRY; | |
208 | ||
209 | ASSERT(tq); | |
210 | ASSERT(t); | |
211 | ||
212 | for (i = 0; i < tq->tq_nthreads; i++) | |
213 | if (tq->tq_threads[i] == (struct task_struct *)t) | |
214 | RETURN(1); | |
215 | ||
216 | RETURN(0); | |
217 | } | |
218 | EXPORT_SYMBOL(__taskq_member); | |
219 | ||
220 | taskqid_t | |
221 | __taskq_dispatch(taskq_t *tq, task_func_t func, void *arg, uint_t flags) | |
222 | { | |
3d061e9d | 223 | spl_task_t *t; |
bcd68186 | 224 | taskqid_t rc = 0; |
225 | ENTRY; | |
f1ca4da6 | 226 | |
937879f1 | 227 | ASSERT(tq); |
228 | ASSERT(func); | |
bcd68186 | 229 | if (unlikely(in_atomic() && (flags & TQ_SLEEP))) { |
230 | CERROR("May schedule while atomic: %s/0x%08x/%d\n", | |
231 | current->comm, preempt_count(), current->pid); | |
232 | SBUG(); | |
233 | } | |
f1ca4da6 | 234 | |
749045bb | 235 | spin_lock_irqsave(&tq->tq_lock, tq->tq_lock_flags); |
f1ca4da6 | 236 | |
bcd68186 | 237 | /* Taskq being destroyed and all tasks drained */ |
238 | if (!(tq->tq_flags & TQ_ACTIVE)) | |
239 | GOTO(out, rc = 0); | |
f1ca4da6 | 240 | |
bcd68186 | 241 | /* Do not queue the task unless there is idle thread for it */ |
242 | ASSERT(tq->tq_nactive <= tq->tq_nthreads); | |
243 | if ((flags & TQ_NOQUEUE) && (tq->tq_nactive == tq->tq_nthreads)) | |
244 | GOTO(out, rc = 0); | |
245 | ||
246 | if ((t = task_alloc(tq, flags)) == NULL) | |
247 | GOTO(out, rc = 0); | |
f1ca4da6 | 248 | |
bcd68186 | 249 | spin_lock(&t->t_lock); |
9ab1ac14 | 250 | list_add_tail(&t->t_list, &tq->tq_pend_list); |
bcd68186 | 251 | t->t_id = rc = tq->tq_next_id; |
252 | tq->tq_next_id++; | |
253 | t->t_func = func; | |
254 | t->t_arg = arg; | |
255 | spin_unlock(&t->t_lock); | |
256 | ||
257 | wake_up(&tq->tq_work_waitq); | |
258 | out: | |
749045bb | 259 | spin_unlock_irqrestore(&tq->tq_lock, tq->tq_lock_flags); |
bcd68186 | 260 | RETURN(rc); |
f1ca4da6 | 261 | } |
f1b59d26 | 262 | EXPORT_SYMBOL(__taskq_dispatch); |
f1ca4da6 | 263 | |
bcd68186 | 264 | /* NOTE: Must be called with tq->tq_lock held */ |
265 | static taskqid_t | |
266 | taskq_lowest_id(taskq_t *tq) | |
267 | { | |
268 | taskqid_t lowest_id = ~0; | |
3d061e9d | 269 | spl_task_t *t; |
bcd68186 | 270 | ENTRY; |
271 | ||
272 | ASSERT(tq); | |
273 | ASSERT(spin_is_locked(&tq->tq_lock)); | |
274 | ||
275 | list_for_each_entry(t, &tq->tq_pend_list, t_list) | |
276 | if (t->t_id < lowest_id) | |
277 | lowest_id = t->t_id; | |
278 | ||
279 | list_for_each_entry(t, &tq->tq_work_list, t_list) | |
280 | if (t->t_id < lowest_id) | |
281 | lowest_id = t->t_id; | |
282 | ||
283 | RETURN(lowest_id); | |
284 | } | |
285 | ||
286 | static int | |
287 | taskq_thread(void *args) | |
288 | { | |
289 | DECLARE_WAITQUEUE(wait, current); | |
290 | sigset_t blocked; | |
291 | taskqid_t id; | |
292 | taskq_t *tq = args; | |
3d061e9d | 293 | spl_task_t *t; |
bcd68186 | 294 | ENTRY; |
295 | ||
296 | ASSERT(tq); | |
297 | current->flags |= PF_NOFREEZE; | |
298 | ||
299 | sigfillset(&blocked); | |
300 | sigprocmask(SIG_BLOCK, &blocked, NULL); | |
301 | flush_signals(current); | |
302 | ||
749045bb | 303 | spin_lock_irqsave(&tq->tq_lock, tq->tq_lock_flags); |
bcd68186 | 304 | tq->tq_nthreads++; |
305 | wake_up(&tq->tq_wait_waitq); | |
306 | set_current_state(TASK_INTERRUPTIBLE); | |
307 | ||
308 | while (!kthread_should_stop()) { | |
309 | ||
310 | add_wait_queue(&tq->tq_work_waitq, &wait); | |
311 | if (list_empty(&tq->tq_pend_list)) { | |
749045bb | 312 | spin_unlock_irqrestore(&tq->tq_lock, tq->tq_lock_flags); |
bcd68186 | 313 | schedule(); |
749045bb | 314 | spin_lock_irqsave(&tq->tq_lock, tq->tq_lock_flags); |
bcd68186 | 315 | } else { |
316 | __set_current_state(TASK_RUNNING); | |
317 | } | |
318 | ||
319 | remove_wait_queue(&tq->tq_work_waitq, &wait); | |
320 | if (!list_empty(&tq->tq_pend_list)) { | |
3d061e9d | 321 | t = list_entry(tq->tq_pend_list.next, spl_task_t, t_list); |
bcd68186 | 322 | list_del_init(&t->t_list); |
9ab1ac14 | 323 | list_add_tail(&t->t_list, &tq->tq_work_list); |
bcd68186 | 324 | tq->tq_nactive++; |
749045bb | 325 | spin_unlock_irqrestore(&tq->tq_lock, tq->tq_lock_flags); |
bcd68186 | 326 | |
327 | /* Perform the requested task */ | |
328 | t->t_func(t->t_arg); | |
329 | ||
749045bb | 330 | spin_lock_irqsave(&tq->tq_lock, tq->tq_lock_flags); |
bcd68186 | 331 | tq->tq_nactive--; |
332 | id = t->t_id; | |
333 | task_done(tq, t); | |
334 | ||
335 | /* Update the lowest remaining taskqid yet to run */ | |
336 | if (tq->tq_lowest_id == id) { | |
337 | tq->tq_lowest_id = taskq_lowest_id(tq); | |
338 | ASSERT(tq->tq_lowest_id > id); | |
339 | } | |
340 | ||
341 | wake_up_all(&tq->tq_wait_waitq); | |
342 | } | |
343 | ||
344 | set_current_state(TASK_INTERRUPTIBLE); | |
345 | ||
346 | } | |
347 | ||
348 | __set_current_state(TASK_RUNNING); | |
349 | tq->tq_nthreads--; | |
749045bb | 350 | spin_unlock_irqrestore(&tq->tq_lock, tq->tq_lock_flags); |
bcd68186 | 351 | |
352 | RETURN(0); | |
353 | } | |
354 | ||
f1ca4da6 | 355 | taskq_t * |
356 | __taskq_create(const char *name, int nthreads, pri_t pri, | |
357 | int minalloc, int maxalloc, uint_t flags) | |
358 | { | |
bcd68186 | 359 | taskq_t *tq; |
360 | struct task_struct *t; | |
361 | int rc = 0, i, j = 0; | |
362 | ENTRY; | |
363 | ||
364 | ASSERT(name != NULL); | |
365 | ASSERT(pri <= maxclsyspri); | |
366 | ASSERT(minalloc >= 0); | |
367 | ASSERT(maxalloc <= INT_MAX); | |
368 | ASSERT(!(flags & (TASKQ_CPR_SAFE | TASKQ_DYNAMIC))); /* Unsupported */ | |
369 | ||
370 | tq = kmem_alloc(sizeof(*tq), KM_SLEEP); | |
371 | if (tq == NULL) | |
372 | RETURN(NULL); | |
373 | ||
374 | tq->tq_threads = kmem_alloc(nthreads * sizeof(t), KM_SLEEP); | |
375 | if (tq->tq_threads == NULL) { | |
376 | kmem_free(tq, sizeof(*tq)); | |
377 | RETURN(NULL); | |
378 | } | |
379 | ||
380 | spin_lock_init(&tq->tq_lock); | |
749045bb | 381 | spin_lock_irqsave(&tq->tq_lock, tq->tq_lock_flags); |
bcd68186 | 382 | tq->tq_name = name; |
383 | tq->tq_nactive = 0; | |
384 | tq->tq_nthreads = 0; | |
385 | tq->tq_pri = pri; | |
386 | tq->tq_minalloc = minalloc; | |
387 | tq->tq_maxalloc = maxalloc; | |
388 | tq->tq_nalloc = 0; | |
389 | tq->tq_flags = (flags | TQ_ACTIVE); | |
390 | tq->tq_next_id = 1; | |
391 | tq->tq_lowest_id = 1; | |
392 | INIT_LIST_HEAD(&tq->tq_free_list); | |
393 | INIT_LIST_HEAD(&tq->tq_work_list); | |
394 | INIT_LIST_HEAD(&tq->tq_pend_list); | |
395 | init_waitqueue_head(&tq->tq_work_waitq); | |
396 | init_waitqueue_head(&tq->tq_wait_waitq); | |
397 | ||
398 | if (flags & TASKQ_PREPOPULATE) | |
399 | for (i = 0; i < minalloc; i++) | |
400 | task_done(tq, task_alloc(tq, TQ_SLEEP | TQ_NEW)); | |
6e605b6e | 401 | |
749045bb | 402 | spin_unlock_irqrestore(&tq->tq_lock, tq->tq_lock_flags); |
6e605b6e | 403 | |
bcd68186 | 404 | for (i = 0; i < nthreads; i++) { |
405 | t = kthread_create(taskq_thread, tq, "%s/%d", name, i); | |
406 | if (t) { | |
407 | tq->tq_threads[i] = t; | |
408 | kthread_bind(t, i % num_online_cpus()); | |
409 | set_user_nice(t, PRIO_TO_NICE(pri)); | |
410 | wake_up_process(t); | |
411 | j++; | |
412 | } else { | |
413 | tq->tq_threads[i] = NULL; | |
414 | rc = 1; | |
415 | } | |
416 | } | |
417 | ||
418 | /* Wait for all threads to be started before potential destroy */ | |
419 | wait_event(tq->tq_wait_waitq, tq->tq_nthreads == j); | |
420 | ||
421 | if (rc) { | |
422 | __taskq_destroy(tq); | |
423 | tq = NULL; | |
424 | } | |
425 | ||
426 | RETURN(tq); | |
f1ca4da6 | 427 | } |
f1b59d26 | 428 | EXPORT_SYMBOL(__taskq_create); |
b123971f | 429 | |
430 | void | |
431 | __taskq_destroy(taskq_t *tq) | |
432 | { | |
3d061e9d | 433 | spl_task_t *t; |
bcd68186 | 434 | int i, nthreads; |
937879f1 | 435 | ENTRY; |
b123971f | 436 | |
bcd68186 | 437 | ASSERT(tq); |
749045bb | 438 | spin_lock_irqsave(&tq->tq_lock, tq->tq_lock_flags); |
bcd68186 | 439 | tq->tq_flags &= ~TQ_ACTIVE; |
749045bb | 440 | spin_unlock_irqrestore(&tq->tq_lock, tq->tq_lock_flags); |
bcd68186 | 441 | |
442 | /* TQ_ACTIVE cleared prevents new tasks being added to pending */ | |
443 | __taskq_wait(tq); | |
444 | ||
445 | nthreads = tq->tq_nthreads; | |
446 | for (i = 0; i < nthreads; i++) | |
447 | if (tq->tq_threads[i]) | |
448 | kthread_stop(tq->tq_threads[i]); | |
449 | ||
749045bb | 450 | spin_lock_irqsave(&tq->tq_lock, tq->tq_lock_flags); |
bcd68186 | 451 | |
452 | while (!list_empty(&tq->tq_free_list)) { | |
3d061e9d | 453 | t = list_entry(tq->tq_free_list.next, spl_task_t, t_list); |
bcd68186 | 454 | list_del_init(&t->t_list); |
455 | task_free(tq, t); | |
456 | } | |
457 | ||
458 | ASSERT(tq->tq_nthreads == 0); | |
459 | ASSERT(tq->tq_nalloc == 0); | |
460 | ASSERT(list_empty(&tq->tq_free_list)); | |
461 | ASSERT(list_empty(&tq->tq_work_list)); | |
462 | ASSERT(list_empty(&tq->tq_pend_list)); | |
463 | ||
749045bb | 464 | spin_unlock_irqrestore(&tq->tq_lock, tq->tq_lock_flags); |
3d061e9d | 465 | kmem_free(tq->tq_threads, nthreads * sizeof(spl_task_t *)); |
bcd68186 | 466 | kmem_free(tq, sizeof(taskq_t)); |
467 | ||
937879f1 | 468 | EXIT; |
b123971f | 469 | } |
bcd68186 | 470 | EXPORT_SYMBOL(__taskq_destroy); |
e9cb2b4f BB |
471 | |
472 | int | |
473 | spl_taskq_init(void) | |
474 | { | |
475 | ENTRY; | |
476 | ||
477 | system_taskq = taskq_create("system_taskq", 64, minclsyspri, 4, 512, | |
478 | TASKQ_DYNAMIC | TASKQ_PREPOPULATE); | |
479 | if (system_taskq == NULL) | |
480 | RETURN(1); | |
481 | ||
482 | RETURN(0); | |
483 | } | |
484 | ||
485 | void | |
486 | spl_taskq_fini(void) | |
487 | { | |
488 | ENTRY; | |
489 | taskq_destroy(system_taskq); | |
490 | EXIT; | |
491 | } |