4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License (the "License").
6 * You may not use this file except in compliance with the License.
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 * or http://www.opensolaris.org/os/licensing.
10 * See the License for the specific language governing permissions
11 * and limitations under the License.
13 * When distributing Covered Code, include this CDDL HEADER in each
14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 * If applicable, add the following below this CDDL HEADER, with the
16 * fields enclosed by brackets "[]" replaced with your own identifying
17 * information: Portions Copyright [yyyy] [name of copyright owner]
22 * Copyright 2010 Sun Microsystems, Inc. All rights reserved.
23 * Use is subject to license terms.
26 * Copyright 2011 Nexenta Systems, Inc. All rights reserved.
29 #include <sys/zfs_context.h>
32 taskq_t
*system_taskq
;
34 #define TASKQ_ACTIVE 0x00010000
38 krwlock_t tq_threadlock
;
39 kcondvar_t tq_dispatch_cv
;
40 kcondvar_t tq_wait_cv
;
41 kthread_t
**tq_threadlist
;
48 kcondvar_t tq_maxalloc_cv
;
50 taskq_ent_t
*tq_freelist
;
55 task_alloc(taskq_t
*tq
, int tqflags
)
60 again
: if ((t
= tq
->tq_freelist
) != NULL
&& tq
->tq_nalloc
>= tq
->tq_minalloc
) {
61 ASSERT(!(t
->tqent_flags
& TQENT_FLAG_PREALLOC
));
62 tq
->tq_freelist
= t
->tqent_next
;
64 if (tq
->tq_nalloc
>= tq
->tq_maxalloc
) {
65 if (!(tqflags
& KM_SLEEP
))
69 * We don't want to exceed tq_maxalloc, but we can't
70 * wait for other tasks to complete (and thus free up
71 * task structures) without risking deadlock with
72 * the caller. So, we just delay for one second
73 * to throttle the allocation rate. If we have tasks
74 * complete before one second timeout expires then
75 * taskq_ent_free will signal us and we will
76 * immediately retry the allocation.
78 tq
->tq_maxalloc_wait
++;
79 rv
= cv_timedwait(&tq
->tq_maxalloc_cv
,
80 &tq
->tq_lock
, ddi_get_lbolt() + hz
);
81 tq
->tq_maxalloc_wait
--;
83 goto again
; /* signaled */
85 mutex_exit(&tq
->tq_lock
);
87 t
= kmem_alloc(sizeof (taskq_ent_t
), tqflags
);
89 mutex_enter(&tq
->tq_lock
);
91 /* Make sure we start without any flags */
100 task_free(taskq_t
*tq
, taskq_ent_t
*t
)
102 if (tq
->tq_nalloc
<= tq
->tq_minalloc
) {
103 t
->tqent_next
= tq
->tq_freelist
;
107 mutex_exit(&tq
->tq_lock
);
108 kmem_free(t
, sizeof (taskq_ent_t
));
109 mutex_enter(&tq
->tq_lock
);
112 if (tq
->tq_maxalloc_wait
)
113 cv_signal(&tq
->tq_maxalloc_cv
);
117 taskq_dispatch(taskq_t
*tq
, task_func_t func
, void *arg
, uint_t tqflags
)
126 mutex_enter(&tq
->tq_lock
);
127 ASSERT(tq
->tq_flags
& TASKQ_ACTIVE
);
128 if ((t
= task_alloc(tq
, tqflags
)) == NULL
) {
129 mutex_exit(&tq
->tq_lock
);
132 if (tqflags
& TQ_FRONT
) {
133 t
->tqent_next
= tq
->tq_task
.tqent_next
;
134 t
->tqent_prev
= &tq
->tq_task
;
136 t
->tqent_next
= &tq
->tq_task
;
137 t
->tqent_prev
= tq
->tq_task
.tqent_prev
;
139 t
->tqent_next
->tqent_prev
= t
;
140 t
->tqent_prev
->tqent_next
= t
;
141 t
->tqent_func
= func
;
144 ASSERT(!(t
->tqent_flags
& TQENT_FLAG_PREALLOC
));
146 cv_signal(&tq
->tq_dispatch_cv
);
147 mutex_exit(&tq
->tq_lock
);
152 taskq_empty_ent(taskq_ent_t
*t
)
154 return t
->tqent_next
== NULL
;
158 taskq_init_ent(taskq_ent_t
*t
)
160 t
->tqent_next
= NULL
;
161 t
->tqent_prev
= NULL
;
162 t
->tqent_func
= NULL
;
168 taskq_dispatch_ent(taskq_t
*tq
, task_func_t func
, void *arg
, uint_t flags
,
171 ASSERT(func
!= NULL
);
172 ASSERT(!(tq
->tq_flags
& TASKQ_DYNAMIC
));
175 * Mark it as a prealloc'd task. This is important
176 * to ensure that we don't free it later.
178 t
->tqent_flags
|= TQENT_FLAG_PREALLOC
;
180 * Enqueue the task to the underlying queue.
182 mutex_enter(&tq
->tq_lock
);
184 if (flags
& TQ_FRONT
) {
185 t
->tqent_next
= tq
->tq_task
.tqent_next
;
186 t
->tqent_prev
= &tq
->tq_task
;
188 t
->tqent_next
= &tq
->tq_task
;
189 t
->tqent_prev
= tq
->tq_task
.tqent_prev
;
191 t
->tqent_next
->tqent_prev
= t
;
192 t
->tqent_prev
->tqent_next
= t
;
193 t
->tqent_func
= func
;
195 cv_signal(&tq
->tq_dispatch_cv
);
196 mutex_exit(&tq
->tq_lock
);
200 taskq_wait(taskq_t
*tq
)
202 mutex_enter(&tq
->tq_lock
);
203 while (tq
->tq_task
.tqent_next
!= &tq
->tq_task
|| tq
->tq_active
!= 0)
204 cv_wait(&tq
->tq_wait_cv
, &tq
->tq_lock
);
205 mutex_exit(&tq
->tq_lock
);
209 taskq_thread(void *arg
)
215 mutex_enter(&tq
->tq_lock
);
216 while (tq
->tq_flags
& TASKQ_ACTIVE
) {
217 if ((t
= tq
->tq_task
.tqent_next
) == &tq
->tq_task
) {
218 if (--tq
->tq_active
== 0)
219 cv_broadcast(&tq
->tq_wait_cv
);
220 cv_wait(&tq
->tq_dispatch_cv
, &tq
->tq_lock
);
224 t
->tqent_prev
->tqent_next
= t
->tqent_next
;
225 t
->tqent_next
->tqent_prev
= t
->tqent_prev
;
226 t
->tqent_next
= NULL
;
227 t
->tqent_prev
= NULL
;
228 prealloc
= t
->tqent_flags
& TQENT_FLAG_PREALLOC
;
229 mutex_exit(&tq
->tq_lock
);
231 rw_enter(&tq
->tq_threadlock
, RW_READER
);
232 t
->tqent_func(t
->tqent_arg
);
233 rw_exit(&tq
->tq_threadlock
);
235 mutex_enter(&tq
->tq_lock
);
240 cv_broadcast(&tq
->tq_wait_cv
);
241 mutex_exit(&tq
->tq_lock
);
247 taskq_create(const char *name
, int nthreads
, pri_t pri
,
248 int minalloc
, int maxalloc
, uint_t flags
)
250 taskq_t
*tq
= kmem_zalloc(sizeof (taskq_t
), KM_SLEEP
);
253 if (flags
& TASKQ_THREADS_CPU_PCT
) {
255 ASSERT3S(nthreads
, >=, 0);
256 ASSERT3S(nthreads
, <=, 100);
257 pct
= MIN(nthreads
, 100);
260 nthreads
= (sysconf(_SC_NPROCESSORS_ONLN
) * pct
) / 100;
261 nthreads
= MAX(nthreads
, 1); /* need at least 1 thread */
263 ASSERT3S(nthreads
, >=, 1);
266 rw_init(&tq
->tq_threadlock
, NULL
, RW_DEFAULT
, NULL
);
267 mutex_init(&tq
->tq_lock
, NULL
, MUTEX_DEFAULT
, NULL
);
268 cv_init(&tq
->tq_dispatch_cv
, NULL
, CV_DEFAULT
, NULL
);
269 cv_init(&tq
->tq_wait_cv
, NULL
, CV_DEFAULT
, NULL
);
270 cv_init(&tq
->tq_maxalloc_cv
, NULL
, CV_DEFAULT
, NULL
);
271 tq
->tq_flags
= flags
| TASKQ_ACTIVE
;
272 tq
->tq_active
= nthreads
;
273 tq
->tq_nthreads
= nthreads
;
274 tq
->tq_minalloc
= minalloc
;
275 tq
->tq_maxalloc
= maxalloc
;
276 tq
->tq_task
.tqent_next
= &tq
->tq_task
;
277 tq
->tq_task
.tqent_prev
= &tq
->tq_task
;
278 tq
->tq_threadlist
= kmem_alloc(nthreads
*sizeof(kthread_t
*), KM_SLEEP
);
280 if (flags
& TASKQ_PREPOPULATE
) {
281 mutex_enter(&tq
->tq_lock
);
282 while (minalloc
-- > 0)
283 task_free(tq
, task_alloc(tq
, KM_SLEEP
));
284 mutex_exit(&tq
->tq_lock
);
287 for (t
= 0; t
< nthreads
; t
++)
288 VERIFY((tq
->tq_threadlist
[t
] = thread_create(NULL
, 0,
289 taskq_thread
, tq
, TS_RUN
, NULL
, 0, 0)) != NULL
);
295 taskq_destroy(taskq_t
*tq
)
297 int nthreads
= tq
->tq_nthreads
;
301 mutex_enter(&tq
->tq_lock
);
303 tq
->tq_flags
&= ~TASKQ_ACTIVE
;
304 cv_broadcast(&tq
->tq_dispatch_cv
);
306 while (tq
->tq_nthreads
!= 0)
307 cv_wait(&tq
->tq_wait_cv
, &tq
->tq_lock
);
310 while (tq
->tq_nalloc
!= 0) {
311 ASSERT(tq
->tq_freelist
!= NULL
);
312 task_free(tq
, task_alloc(tq
, KM_SLEEP
));
315 mutex_exit(&tq
->tq_lock
);
317 kmem_free(tq
->tq_threadlist
, nthreads
* sizeof (kthread_t
*));
319 rw_destroy(&tq
->tq_threadlock
);
320 mutex_destroy(&tq
->tq_lock
);
321 cv_destroy(&tq
->tq_dispatch_cv
);
322 cv_destroy(&tq
->tq_wait_cv
);
323 cv_destroy(&tq
->tq_maxalloc_cv
);
325 kmem_free(tq
, sizeof (taskq_t
));
329 taskq_member(taskq_t
*tq
, kthread_t
*t
)
336 for (i
= 0; i
< tq
->tq_nthreads
; i
++)
337 if (tq
->tq_threadlist
[i
] == t
)
344 system_taskq_init(void)
346 system_taskq
= taskq_create("system_taskq", 64, minclsyspri
, 4, 512,
347 TASKQ_DYNAMIC
| TASKQ_PREPOPULATE
);
351 system_taskq_fini(void)
353 taskq_destroy(system_taskq
);
354 system_taskq
= NULL
; /* defensive */