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 2009 Sun Microsystems, Inc. All rights reserved.
23 * Use is subject to license terms.
26 #include <sys/zfs_context.h>
29 taskq_t *system_taskq;
32 struct task *task_next;
33 struct task *task_prev;
34 task_func_t *task_func;
38 #define TASKQ_ACTIVE 0x00010000
42 krwlock_t tq_threadlock;
43 kcondvar_t tq_dispatch_cv;
44 kcondvar_t tq_wait_cv;
45 thread_t *tq_threadlist;
57 task_alloc(taskq_t *tq, int tqflags)
61 if ((t = tq->tq_freelist) != NULL && tq->tq_nalloc >= tq->tq_minalloc) {
62 tq->tq_freelist = t->task_next;
64 mutex_exit(&tq->tq_lock);
65 if (tq->tq_nalloc >= tq->tq_maxalloc) {
66 if (!(tqflags & KM_SLEEP)) {
67 mutex_enter(&tq->tq_lock);
71 * We don't want to exceed tq_maxalloc, but we can't
72 * wait for other tasks to complete (and thus free up
73 * task structures) without risking deadlock with
74 * the caller. So, we just delay for one second
75 * to throttle the allocation rate.
79 t = kmem_alloc(sizeof (task_t), tqflags);
80 mutex_enter(&tq->tq_lock);
88 task_free(taskq_t *tq, task_t *t)
90 if (tq->tq_nalloc <= tq->tq_minalloc) {
91 t->task_next = tq->tq_freelist;
95 mutex_exit(&tq->tq_lock);
96 kmem_free(t, sizeof (task_t));
97 mutex_enter(&tq->tq_lock);
102 taskq_dispatch(taskq_t *tq, task_func_t func, void *arg, uint_t tqflags)
111 mutex_enter(&tq->tq_lock);
112 ASSERT(tq->tq_flags & TASKQ_ACTIVE);
113 if ((t = task_alloc(tq, tqflags)) == NULL) {
114 mutex_exit(&tq->tq_lock);
117 t->task_next = &tq->tq_task;
118 t->task_prev = tq->tq_task.task_prev;
119 t->task_next->task_prev = t;
120 t->task_prev->task_next = t;
123 cv_signal(&tq->tq_dispatch_cv);
124 mutex_exit(&tq->tq_lock);
129 taskq_wait(taskq_t *tq)
131 mutex_enter(&tq->tq_lock);
132 while (tq->tq_task.task_next != &tq->tq_task || tq->tq_active != 0)
133 cv_wait(&tq->tq_wait_cv, &tq->tq_lock);
134 mutex_exit(&tq->tq_lock);
138 taskq_thread(void *arg)
143 mutex_enter(&tq->tq_lock);
144 while (tq->tq_flags & TASKQ_ACTIVE) {
145 if ((t = tq->tq_task.task_next) == &tq->tq_task) {
146 if (--tq->tq_active == 0)
147 cv_broadcast(&tq->tq_wait_cv);
148 cv_wait(&tq->tq_dispatch_cv, &tq->tq_lock);
152 t->task_prev->task_next = t->task_next;
153 t->task_next->task_prev = t->task_prev;
154 mutex_exit(&tq->tq_lock);
156 rw_enter(&tq->tq_threadlock, RW_READER);
157 t->task_func(t->task_arg);
158 rw_exit(&tq->tq_threadlock);
160 mutex_enter(&tq->tq_lock);
164 cv_broadcast(&tq->tq_wait_cv);
165 mutex_exit(&tq->tq_lock);
171 taskq_create(const char *name, int nthreads, pri_t pri,
172 int minalloc, int maxalloc, uint_t flags)
174 taskq_t *tq = kmem_zalloc(sizeof (taskq_t), KM_SLEEP);
177 if (flags & TASKQ_THREADS_CPU_PCT) {
179 ASSERT3S(nthreads, >=, 0);
180 ASSERT3S(nthreads, <=, 100);
181 pct = MIN(nthreads, 100);
184 nthreads = (sysconf(_SC_NPROCESSORS_ONLN) * pct) / 100;
185 nthreads = MAX(nthreads, 1); /* need at least 1 thread */
187 ASSERT3S(nthreads, >=, 1);
190 rw_init(&tq->tq_threadlock, NULL, RW_DEFAULT, NULL);
191 mutex_init(&tq->tq_lock, NULL, MUTEX_DEFAULT, NULL);
192 cv_init(&tq->tq_dispatch_cv, NULL, CV_DEFAULT, NULL);
193 cv_init(&tq->tq_wait_cv, NULL, CV_DEFAULT, NULL);
194 tq->tq_flags = flags | TASKQ_ACTIVE;
195 tq->tq_active = nthreads;
196 tq->tq_nthreads = nthreads;
197 tq->tq_minalloc = minalloc;
198 tq->tq_maxalloc = maxalloc;
199 tq->tq_task.task_next = &tq->tq_task;
200 tq->tq_task.task_prev = &tq->tq_task;
201 tq->tq_threadlist = kmem_alloc(nthreads * sizeof (thread_t), KM_SLEEP);
203 if (flags & TASKQ_PREPOPULATE) {
204 mutex_enter(&tq->tq_lock);
205 while (minalloc-- > 0)
206 task_free(tq, task_alloc(tq, KM_SLEEP));
207 mutex_exit(&tq->tq_lock);
210 for (t = 0; t < nthreads; t++)
211 (void) thr_create(0, 0, taskq_thread,
212 tq, THR_BOUND, &tq->tq_threadlist[t]);
218 taskq_destroy(taskq_t *tq)
221 int nthreads = tq->tq_nthreads;
225 mutex_enter(&tq->tq_lock);
227 tq->tq_flags &= ~TASKQ_ACTIVE;
228 cv_broadcast(&tq->tq_dispatch_cv);
230 while (tq->tq_nthreads != 0)
231 cv_wait(&tq->tq_wait_cv, &tq->tq_lock);
234 while (tq->tq_nalloc != 0) {
235 ASSERT(tq->tq_freelist != NULL);
236 task_free(tq, task_alloc(tq, KM_SLEEP));
239 mutex_exit(&tq->tq_lock);
241 for (t = 0; t < nthreads; t++)
242 (void) thr_join(tq->tq_threadlist[t], NULL, NULL);
244 kmem_free(tq->tq_threadlist, nthreads * sizeof (thread_t));
246 rw_destroy(&tq->tq_threadlock);
247 mutex_destroy(&tq->tq_lock);
248 cv_destroy(&tq->tq_dispatch_cv);
249 cv_destroy(&tq->tq_wait_cv);
251 kmem_free(tq, sizeof (taskq_t));
255 taskq_member(taskq_t *tq, void *t)
262 for (i = 0; i < tq->tq_nthreads; i++)
263 if (tq->tq_threadlist[i] == (thread_t)(uintptr_t)t)
270 system_taskq_init(void)
272 system_taskq = taskq_create("system_taskq", 64, minclsyspri, 4, 512,
273 TASKQ_DYNAMIC | TASKQ_PREPOPULATE);