| /* |
| * CDDL HEADER START |
| * |
| * The contents of this file are subject to the terms of the |
| * Common Development and Distribution License (the "License"). |
| * You may not use this file except in compliance with the License. |
| * |
| * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE |
| * or http://www.opensolaris.org/os/licensing. |
| * See the License for the specific language governing permissions |
| * and limitations under the License. |
| * |
| * When distributing Covered Code, include this CDDL HEADER in each |
| * file and include the License file at usr/src/OPENSOLARIS.LICENSE. |
| * If applicable, add the following below this CDDL HEADER, with the |
| * fields enclosed by brackets "[]" replaced with your own identifying |
| * information: Portions Copyright [yyyy] [name of copyright owner] |
| * |
| * CDDL HEADER END |
| */ |
| /* |
| * Copyright 2010 Sun Microsystems, Inc. All rights reserved. |
| * Use is subject to license terms. |
| */ |
| /* |
| * Copyright 2011 Nexenta Systems, Inc. All rights reserved. |
| * Copyright 2012 Garrett D'Amore <garrett@damore.org>. All rights reserved. |
| * Copyright (c) 2014 by Delphix. All rights reserved. |
| */ |
| |
| #include <sys/zfs_context.h> |
| |
| int taskq_now; |
| taskq_t *system_taskq; |
| taskq_t *system_delay_taskq; |
| |
| static pthread_key_t taskq_tsd; |
| |
| #define TASKQ_ACTIVE 0x00010000 |
| |
| static taskq_ent_t * |
| task_alloc(taskq_t *tq, int tqflags) |
| { |
| taskq_ent_t *t; |
| int rv; |
| |
| again: if ((t = tq->tq_freelist) != NULL && tq->tq_nalloc >= tq->tq_minalloc) { |
| ASSERT(!(t->tqent_flags & TQENT_FLAG_PREALLOC)); |
| tq->tq_freelist = t->tqent_next; |
| } else { |
| if (tq->tq_nalloc >= tq->tq_maxalloc) { |
| if (!(tqflags & KM_SLEEP)) |
| return (NULL); |
| |
| /* |
| * We don't want to exceed tq_maxalloc, but we can't |
| * wait for other tasks to complete (and thus free up |
| * task structures) without risking deadlock with |
| * the caller. So, we just delay for one second |
| * to throttle the allocation rate. If we have tasks |
| * complete before one second timeout expires then |
| * taskq_ent_free will signal us and we will |
| * immediately retry the allocation. |
| */ |
| tq->tq_maxalloc_wait++; |
| rv = cv_timedwait(&tq->tq_maxalloc_cv, |
| &tq->tq_lock, ddi_get_lbolt() + hz); |
| tq->tq_maxalloc_wait--; |
| if (rv > 0) |
| goto again; /* signaled */ |
| } |
| mutex_exit(&tq->tq_lock); |
| |
| t = kmem_alloc(sizeof (taskq_ent_t), tqflags); |
| |
| mutex_enter(&tq->tq_lock); |
| if (t != NULL) { |
| /* Make sure we start without any flags */ |
| t->tqent_flags = 0; |
| tq->tq_nalloc++; |
| } |
| } |
| return (t); |
| } |
| |
| static void |
| task_free(taskq_t *tq, taskq_ent_t *t) |
| { |
| if (tq->tq_nalloc <= tq->tq_minalloc) { |
| t->tqent_next = tq->tq_freelist; |
| tq->tq_freelist = t; |
| } else { |
| tq->tq_nalloc--; |
| mutex_exit(&tq->tq_lock); |
| kmem_free(t, sizeof (taskq_ent_t)); |
| mutex_enter(&tq->tq_lock); |
| } |
| |
| if (tq->tq_maxalloc_wait) |
| cv_signal(&tq->tq_maxalloc_cv); |
| } |
| |
| taskqid_t |
| taskq_dispatch(taskq_t *tq, task_func_t func, void *arg, uint_t tqflags) |
| { |
| taskq_ent_t *t; |
| |
| if (taskq_now) { |
| func(arg); |
| return (1); |
| } |
| |
| mutex_enter(&tq->tq_lock); |
| ASSERT(tq->tq_flags & TASKQ_ACTIVE); |
| if ((t = task_alloc(tq, tqflags)) == NULL) { |
| mutex_exit(&tq->tq_lock); |
| return (0); |
| } |
| if (tqflags & TQ_FRONT) { |
| t->tqent_next = tq->tq_task.tqent_next; |
| t->tqent_prev = &tq->tq_task; |
| } else { |
| t->tqent_next = &tq->tq_task; |
| t->tqent_prev = tq->tq_task.tqent_prev; |
| } |
| t->tqent_next->tqent_prev = t; |
| t->tqent_prev->tqent_next = t; |
| t->tqent_func = func; |
| t->tqent_arg = arg; |
| t->tqent_flags = 0; |
| cv_signal(&tq->tq_dispatch_cv); |
| mutex_exit(&tq->tq_lock); |
| return (1); |
| } |
| |
| taskqid_t |
| taskq_dispatch_delay(taskq_t *tq, task_func_t func, void *arg, uint_t tqflags, |
| clock_t expire_time) |
| { |
| return (0); |
| } |
| |
| int |
| taskq_empty_ent(taskq_ent_t *t) |
| { |
| return (t->tqent_next == NULL); |
| } |
| |
| void |
| taskq_init_ent(taskq_ent_t *t) |
| { |
| t->tqent_next = NULL; |
| t->tqent_prev = NULL; |
| t->tqent_func = NULL; |
| t->tqent_arg = NULL; |
| t->tqent_flags = 0; |
| } |
| |
| void |
| taskq_dispatch_ent(taskq_t *tq, task_func_t func, void *arg, uint_t flags, |
| taskq_ent_t *t) |
| { |
| ASSERT(func != NULL); |
| |
| /* |
| * Mark it as a prealloc'd task. This is important |
| * to ensure that we don't free it later. |
| */ |
| t->tqent_flags |= TQENT_FLAG_PREALLOC; |
| /* |
| * Enqueue the task to the underlying queue. |
| */ |
| mutex_enter(&tq->tq_lock); |
| |
| if (flags & TQ_FRONT) { |
| t->tqent_next = tq->tq_task.tqent_next; |
| t->tqent_prev = &tq->tq_task; |
| } else { |
| t->tqent_next = &tq->tq_task; |
| t->tqent_prev = tq->tq_task.tqent_prev; |
| } |
| t->tqent_next->tqent_prev = t; |
| t->tqent_prev->tqent_next = t; |
| t->tqent_func = func; |
| t->tqent_arg = arg; |
| cv_signal(&tq->tq_dispatch_cv); |
| mutex_exit(&tq->tq_lock); |
| } |
| |
| void |
| taskq_wait(taskq_t *tq) |
| { |
| mutex_enter(&tq->tq_lock); |
| while (tq->tq_task.tqent_next != &tq->tq_task || tq->tq_active != 0) |
| cv_wait(&tq->tq_wait_cv, &tq->tq_lock); |
| mutex_exit(&tq->tq_lock); |
| } |
| |
| void |
| taskq_wait_id(taskq_t *tq, taskqid_t id) |
| { |
| taskq_wait(tq); |
| } |
| |
| void |
| taskq_wait_outstanding(taskq_t *tq, taskqid_t id) |
| { |
| taskq_wait(tq); |
| } |
| |
| static void |
| taskq_thread(void *arg) |
| { |
| taskq_t *tq = arg; |
| taskq_ent_t *t; |
| boolean_t prealloc; |
| |
| VERIFY0(pthread_setspecific(taskq_tsd, tq)); |
| |
| mutex_enter(&tq->tq_lock); |
| while (tq->tq_flags & TASKQ_ACTIVE) { |
| if ((t = tq->tq_task.tqent_next) == &tq->tq_task) { |
| if (--tq->tq_active == 0) |
| cv_broadcast(&tq->tq_wait_cv); |
| cv_wait(&tq->tq_dispatch_cv, &tq->tq_lock); |
| tq->tq_active++; |
| continue; |
| } |
| t->tqent_prev->tqent_next = t->tqent_next; |
| t->tqent_next->tqent_prev = t->tqent_prev; |
| t->tqent_next = NULL; |
| t->tqent_prev = NULL; |
| prealloc = t->tqent_flags & TQENT_FLAG_PREALLOC; |
| mutex_exit(&tq->tq_lock); |
| |
| rw_enter(&tq->tq_threadlock, RW_READER); |
| t->tqent_func(t->tqent_arg); |
| rw_exit(&tq->tq_threadlock); |
| |
| mutex_enter(&tq->tq_lock); |
| if (!prealloc) |
| task_free(tq, t); |
| } |
| tq->tq_nthreads--; |
| cv_broadcast(&tq->tq_wait_cv); |
| mutex_exit(&tq->tq_lock); |
| thread_exit(); |
| } |
| |
| /*ARGSUSED*/ |
| taskq_t * |
| taskq_create(const char *name, int nthreads, pri_t pri, |
| int minalloc, int maxalloc, uint_t flags) |
| { |
| taskq_t *tq = kmem_zalloc(sizeof (taskq_t), KM_SLEEP); |
| int t; |
| |
| if (flags & TASKQ_THREADS_CPU_PCT) { |
| int pct; |
| ASSERT3S(nthreads, >=, 0); |
| ASSERT3S(nthreads, <=, 100); |
| pct = MIN(nthreads, 100); |
| pct = MAX(pct, 0); |
| |
| nthreads = (sysconf(_SC_NPROCESSORS_ONLN) * pct) / 100; |
| nthreads = MAX(nthreads, 1); /* need at least 1 thread */ |
| } else { |
| ASSERT3S(nthreads, >=, 1); |
| } |
| |
| rw_init(&tq->tq_threadlock, NULL, RW_DEFAULT, NULL); |
| mutex_init(&tq->tq_lock, NULL, MUTEX_DEFAULT, NULL); |
| cv_init(&tq->tq_dispatch_cv, NULL, CV_DEFAULT, NULL); |
| cv_init(&tq->tq_wait_cv, NULL, CV_DEFAULT, NULL); |
| cv_init(&tq->tq_maxalloc_cv, NULL, CV_DEFAULT, NULL); |
| (void) strncpy(tq->tq_name, name, TASKQ_NAMELEN); |
| tq->tq_flags = flags | TASKQ_ACTIVE; |
| tq->tq_active = nthreads; |
| tq->tq_nthreads = nthreads; |
| tq->tq_minalloc = minalloc; |
| tq->tq_maxalloc = maxalloc; |
| tq->tq_task.tqent_next = &tq->tq_task; |
| tq->tq_task.tqent_prev = &tq->tq_task; |
| tq->tq_threadlist = kmem_alloc(nthreads * sizeof (kthread_t *), |
| KM_SLEEP); |
| |
| if (flags & TASKQ_PREPOPULATE) { |
| mutex_enter(&tq->tq_lock); |
| while (minalloc-- > 0) |
| task_free(tq, task_alloc(tq, KM_SLEEP)); |
| mutex_exit(&tq->tq_lock); |
| } |
| |
| for (t = 0; t < nthreads; t++) |
| VERIFY((tq->tq_threadlist[t] = thread_create(NULL, 0, |
| taskq_thread, tq, 0, &p0, TS_RUN, pri)) != NULL); |
| |
| return (tq); |
| } |
| |
| void |
| taskq_destroy(taskq_t *tq) |
| { |
| int nthreads = tq->tq_nthreads; |
| |
| taskq_wait(tq); |
| |
| mutex_enter(&tq->tq_lock); |
| |
| tq->tq_flags &= ~TASKQ_ACTIVE; |
| cv_broadcast(&tq->tq_dispatch_cv); |
| |
| while (tq->tq_nthreads != 0) |
| cv_wait(&tq->tq_wait_cv, &tq->tq_lock); |
| |
| tq->tq_minalloc = 0; |
| while (tq->tq_nalloc != 0) { |
| ASSERT(tq->tq_freelist != NULL); |
| task_free(tq, task_alloc(tq, KM_SLEEP)); |
| } |
| |
| mutex_exit(&tq->tq_lock); |
| |
| kmem_free(tq->tq_threadlist, nthreads * sizeof (kthread_t *)); |
| |
| rw_destroy(&tq->tq_threadlock); |
| mutex_destroy(&tq->tq_lock); |
| cv_destroy(&tq->tq_dispatch_cv); |
| cv_destroy(&tq->tq_wait_cv); |
| cv_destroy(&tq->tq_maxalloc_cv); |
| |
| kmem_free(tq, sizeof (taskq_t)); |
| } |
| |
| int |
| taskq_member(taskq_t *tq, kthread_t *t) |
| { |
| int i; |
| |
| if (taskq_now) |
| return (1); |
| |
| for (i = 0; i < tq->tq_nthreads; i++) |
| if (tq->tq_threadlist[i] == t) |
| return (1); |
| |
| return (0); |
| } |
| |
| taskq_t * |
| taskq_of_curthread(void) |
| { |
| return (pthread_getspecific(taskq_tsd)); |
| } |
| |
| int |
| taskq_cancel_id(taskq_t *tq, taskqid_t id) |
| { |
| return (ENOENT); |
| } |
| |
| void |
| system_taskq_init(void) |
| { |
| VERIFY0(pthread_key_create(&taskq_tsd, NULL)); |
| system_taskq = taskq_create("system_taskq", 64, maxclsyspri, 4, 512, |
| TASKQ_DYNAMIC | TASKQ_PREPOPULATE); |
| system_delay_taskq = taskq_create("delay_taskq", 4, maxclsyspri, 4, |
| 512, TASKQ_DYNAMIC | TASKQ_PREPOPULATE); |
| } |
| |
| void |
| system_taskq_fini(void) |
| { |
| taskq_destroy(system_taskq); |
| system_taskq = NULL; /* defensive */ |
| taskq_destroy(system_delay_taskq); |
| system_delay_taskq = NULL; |
| VERIFY0(pthread_key_delete(taskq_tsd)); |
| } |