subr_taskqueue.c revision 188548
152419Sjulian/*- 252419Sjulian * Copyright (c) 2000 Doug Rabson 352419Sjulian * All rights reserved. 452419Sjulian * 552419Sjulian * Redistribution and use in source and binary forms, with or without 652419Sjulian * modification, are permitted provided that the following conditions 752419Sjulian * are met: 852419Sjulian * 1. Redistributions of source code must retain the above copyright 952419Sjulian * notice, this list of conditions and the following disclaimer. 1052419Sjulian * 2. Redistributions in binary form must reproduce the above copyright 1152419Sjulian * notice, this list of conditions and the following disclaimer in the 1252419Sjulian * documentation and/or other materials provided with the distribution. 1352419Sjulian * 1452419Sjulian * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 1552419Sjulian * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 1652419Sjulian * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 1752419Sjulian * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 1852419Sjulian * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 1952419Sjulian * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 2052419Sjulian * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 2152419Sjulian * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 2252419Sjulian * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 2352419Sjulian * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 2452419Sjulian * SUCH DAMAGE. 2552419Sjulian */ 2652419Sjulian 2752419Sjulian#include <sys/cdefs.h> 2852419Sjulian__FBSDID("$FreeBSD: head/sys/kern/subr_taskqueue.c 188548 2009-02-13 01:16:51Z thompsa $"); 2952419Sjulian 3052419Sjulian#include <sys/param.h> 3152419Sjulian#include <sys/systm.h> 3252419Sjulian#include <sys/bus.h> 3352419Sjulian#include <sys/interrupt.h> 3452419Sjulian#include <sys/kernel.h> 3552419Sjulian#include <sys/kthread.h> 3652419Sjulian#include <sys/lock.h> 3770700Sjulian#include <sys/malloc.h> 3852419Sjulian#include <sys/mutex.h> 3952419Sjulian#include <sys/proc.h> 4052752Sjulian#include <sys/sched.h> 4152419Sjulian#include <sys/taskqueue.h> 4252419Sjulian#include <sys/unistd.h> 4352419Sjulian#include <machine/stdarg.h> 4452419Sjulian 4552419Sjulianstatic MALLOC_DEFINE(M_TASKQUEUE, "taskqueue", "Task Queues"); 4652419Sjulianstatic void *taskqueue_giant_ih; 4752419Sjulianstatic void *taskqueue_ih; 4852419Sjulianstatic STAILQ_HEAD(taskqueue_list, taskqueue) taskqueue_queues; 4952419Sjulianstatic struct mtx taskqueue_queues_mutex; 5052419Sjulian 5152419Sjulianstruct taskqueue { 5252419Sjulian STAILQ_ENTRY(taskqueue) tq_link; 5352419Sjulian STAILQ_HEAD(, task) tq_queue; 5452419Sjulian const char *tq_name; 5552419Sjulian taskqueue_enqueue_fn tq_enqueue; 5652419Sjulian void *tq_context; 5752419Sjulian struct task *tq_running; 5852419Sjulian struct mtx tq_mutex; 5952843Sphk struct thread **tq_threads; 6052419Sjulian int tq_tcount; 6152419Sjulian int tq_spin; 6252419Sjulian int tq_flags; 6352419Sjulian}; 6452419Sjulian 6552419Sjulian#define TQ_FLAGS_ACTIVE (1 << 0) 6652419Sjulian#define TQ_FLAGS_BLOCKED (1 << 1) 6752419Sjulian#define TQ_FLAGS_PENDING (1 << 2) 6852419Sjulian 6952419Sjulianstatic __inline void 7052419SjulianTQ_LOCK(struct taskqueue *tq) 7152419Sjulian{ 7252419Sjulian if (tq->tq_spin) 7352419Sjulian mtx_lock_spin(&tq->tq_mutex); 7452419Sjulian else 7552419Sjulian mtx_lock(&tq->tq_mutex); 7652419Sjulian} 7752419Sjulian 7852419Sjulianstatic __inline void 7952419SjulianTQ_UNLOCK(struct taskqueue *tq) 8052419Sjulian{ 8152419Sjulian if (tq->tq_spin) 8252419Sjulian mtx_unlock_spin(&tq->tq_mutex); 8352419Sjulian else 8452419Sjulian mtx_unlock(&tq->tq_mutex); 8552419Sjulian} 8652419Sjulian 8752419Sjulianstatic void init_taskqueue_list(void *data); 8852419Sjulian 8952419Sjulianstatic __inline int 9052419SjulianTQ_SLEEP(struct taskqueue *tq, void *p, struct mtx *m, int pri, const char *wm, 9152419Sjulian int t) 9252419Sjulian{ 9352419Sjulian if (tq->tq_spin) 9452419Sjulian return (msleep_spin(p, m, wm, t)); 9552419Sjulian return (msleep(p, m, pri, wm, t)); 9652419Sjulian} 9752419Sjulian 9852419Sjulianstatic void 9952419Sjulianinit_taskqueue_list(void *data __unused) 10052419Sjulian{ 10152419Sjulian 10252419Sjulian mtx_init(&taskqueue_queues_mutex, "taskqueue list", NULL, MTX_DEF); 10352419Sjulian STAILQ_INIT(&taskqueue_queues); 10452419Sjulian} 10552419SjulianSYSINIT(taskqueue_list, SI_SUB_INTRINSIC, SI_ORDER_ANY, init_taskqueue_list, 10652419Sjulian NULL); 10752419Sjulian 10852419Sjulianstatic struct taskqueue * 10952419Sjulian_taskqueue_create(const char *name, int mflags, 11052419Sjulian taskqueue_enqueue_fn enqueue, void *context, 11152419Sjulian int mtxflags, const char *mtxname) 11252419Sjulian{ 11352419Sjulian struct taskqueue *queue; 11452419Sjulian 11552419Sjulian queue = malloc(sizeof(struct taskqueue), M_TASKQUEUE, mflags | M_ZERO); 11652419Sjulian if (!queue) 11752419Sjulian return NULL; 11852419Sjulian 11952419Sjulian STAILQ_INIT(&queue->tq_queue); 12052419Sjulian queue->tq_name = name; 12152419Sjulian queue->tq_enqueue = enqueue; 12252419Sjulian queue->tq_context = context; 12352419Sjulian queue->tq_spin = (mtxflags & MTX_SPIN) != 0; 12452419Sjulian queue->tq_flags |= TQ_FLAGS_ACTIVE; 12552419Sjulian mtx_init(&queue->tq_mutex, mtxname, NULL, mtxflags); 12652419Sjulian 12752752Sjulian mtx_lock(&taskqueue_queues_mutex); 12870700Sjulian STAILQ_INSERT_TAIL(&taskqueue_queues, queue, tq_link); 12952752Sjulian mtx_unlock(&taskqueue_queues_mutex); 13052752Sjulian 13152752Sjulian return queue; 13252419Sjulian} 13352419Sjulian 13470700Sjulianstruct taskqueue * 13552419Sjuliantaskqueue_create(const char *name, int mflags, 13652419Sjulian taskqueue_enqueue_fn enqueue, void *context) 13752419Sjulian{ 13852419Sjulian return _taskqueue_create(name, mflags, enqueue, context, 13952419Sjulian MTX_DEF, "taskqueue"); 140129823Sjulian} 141129823Sjulian 142129823Sjulian/* 143129823Sjulian * Signal a taskqueue thread to terminate. 144129823Sjulian */ 145129823Sjulianstatic void 146129823Sjuliantaskqueue_terminate(struct thread **pp, struct taskqueue *tq) 14752419Sjulian{ 14852419Sjulian 14952419Sjulian while (tq->tq_tcount > 0) { 15052419Sjulian wakeup(tq); 15152419Sjulian TQ_SLEEP(tq, pp, &tq->tq_mutex, PWAIT, "taskqueue_destroy", 0); 15252419Sjulian } 15352419Sjulian} 15452419Sjulian 15552419Sjulianvoid 15652419Sjuliantaskqueue_free(struct taskqueue *queue) 15752419Sjulian{ 15852419Sjulian 15952419Sjulian mtx_lock(&taskqueue_queues_mutex); 16052419Sjulian STAILQ_REMOVE(&taskqueue_queues, queue, taskqueue, tq_link); 16152419Sjulian mtx_unlock(&taskqueue_queues_mutex); 16252419Sjulian 16352419Sjulian TQ_LOCK(queue); 16452419Sjulian queue->tq_flags &= ~TQ_FLAGS_ACTIVE; 16552419Sjulian taskqueue_run(queue); 16652419Sjulian taskqueue_terminate(queue->tq_threads, queue); 16752419Sjulian mtx_destroy(&queue->tq_mutex); 16852419Sjulian free(queue->tq_threads, M_TASKQUEUE); 16952419Sjulian free(queue, M_TASKQUEUE); 17052419Sjulian} 17152419Sjulian 17252419Sjulian/* 17352419Sjulian * Returns with the taskqueue locked. 17452419Sjulian */ 17552419Sjulianstruct taskqueue * 17652419Sjuliantaskqueue_find(const char *name) 17752419Sjulian{ 17852419Sjulian struct taskqueue *queue; 17952419Sjulian 18052419Sjulian mtx_lock(&taskqueue_queues_mutex); 18152419Sjulian STAILQ_FOREACH(queue, &taskqueue_queues, tq_link) { 18252419Sjulian if (strcmp(queue->tq_name, name) == 0) { 18352419Sjulian TQ_LOCK(queue); 18452419Sjulian mtx_unlock(&taskqueue_queues_mutex); 18552419Sjulian return queue; 18652419Sjulian } 18752419Sjulian } 18852419Sjulian mtx_unlock(&taskqueue_queues_mutex); 18952419Sjulian return NULL; 19052419Sjulian} 19152419Sjulian 19252419Sjulianint 19352419Sjuliantaskqueue_enqueue(struct taskqueue *queue, struct task *task) 19452419Sjulian{ 19552419Sjulian struct task *ins; 19652419Sjulian struct task *prev; 19752419Sjulian 19852419Sjulian TQ_LOCK(queue); 19952419Sjulian 20052419Sjulian /* 20152419Sjulian * Count multiple enqueues. 20252419Sjulian */ 20352419Sjulian if (task->ta_pending) { 20452419Sjulian task->ta_pending++; 20552419Sjulian TQ_UNLOCK(queue); 20652419Sjulian return 0; 20752419Sjulian } 20852419Sjulian 20952419Sjulian /* 21070700Sjulian * Optimise the case when all tasks have the same priority. 21152419Sjulian */ 21252419Sjulian prev = STAILQ_LAST(&queue->tq_queue, task, ta_link); 21352419Sjulian if (!prev || prev->ta_priority >= task->ta_priority) { 21468876Sdwmalone STAILQ_INSERT_TAIL(&queue->tq_queue, task, ta_link); 21552419Sjulian } else { 21652419Sjulian prev = NULL; 21752419Sjulian for (ins = STAILQ_FIRST(&queue->tq_queue); ins; 21852419Sjulian prev = ins, ins = STAILQ_NEXT(ins, ta_link)) 21952419Sjulian if (ins->ta_priority < task->ta_priority) 22070784Sjulian break; 22170700Sjulian 22252419Sjulian if (prev) 22352419Sjulian STAILQ_INSERT_AFTER(&queue->tq_queue, prev, task, ta_link); 22452419Sjulian else 22552419Sjulian STAILQ_INSERT_HEAD(&queue->tq_queue, task, ta_link); 22652419Sjulian } 22752419Sjulian 22852419Sjulian task->ta_pending = 1; 22952419Sjulian if ((queue->tq_flags & TQ_FLAGS_BLOCKED) == 0) 23052419Sjulian queue->tq_enqueue(queue->tq_context); 23152419Sjulian else 23252419Sjulian queue->tq_flags |= TQ_FLAGS_PENDING; 23352419Sjulian 23452419Sjulian TQ_UNLOCK(queue); 23570784Sjulian 23653648Sarchie return 0; 23753648Sarchie} 23853648Sarchie 23953648Sarchievoid 24052419Sjuliantaskqueue_block(struct taskqueue *queue) 24152419Sjulian{ 24252419Sjulian 24370784Sjulian TQ_LOCK(queue); 24452419Sjulian queue->tq_flags |= TQ_FLAGS_BLOCKED; 24552419Sjulian TQ_UNLOCK(queue); 24652419Sjulian} 24752419Sjulian 24852419Sjulianvoid 24952419Sjuliantaskqueue_unblock(struct taskqueue *queue) 25052419Sjulian{ 25152419Sjulian 25252419Sjulian TQ_LOCK(queue); 25352419Sjulian queue->tq_flags &= ~TQ_FLAGS_BLOCKED; 25452419Sjulian if (queue->tq_flags & TQ_FLAGS_PENDING) { 25552419Sjulian queue->tq_flags &= ~TQ_FLAGS_PENDING; 25652419Sjulian queue->tq_enqueue(queue->tq_context); 25752419Sjulian } 25852419Sjulian TQ_UNLOCK(queue); 25952419Sjulian} 26052419Sjulian 26152419Sjulianvoid 26252419Sjuliantaskqueue_run(struct taskqueue *queue) 26352419Sjulian{ 26470784Sjulian struct task *task; 26552419Sjulian int owned, pending; 26652419Sjulian 26752419Sjulian owned = mtx_owned(&queue->tq_mutex); 26852419Sjulian if (!owned) 26952419Sjulian TQ_LOCK(queue); 27052419Sjulian while (STAILQ_FIRST(&queue->tq_queue)) { 27152419Sjulian /* 27252419Sjulian * Carefully remove the first task from the queue and 27352419Sjulian * zero its pending count. 27452816Sarchie */ 27552419Sjulian task = STAILQ_FIRST(&queue->tq_queue); 27652816Sarchie STAILQ_REMOVE_HEAD(&queue->tq_queue, ta_link); 27752816Sarchie pending = task->ta_pending; 27852816Sarchie task->ta_pending = 0; 27952816Sarchie queue->tq_running = task; 28052419Sjulian TQ_UNLOCK(queue); 28152419Sjulian 28252419Sjulian task->ta_func(task->ta_context, pending); 28352419Sjulian 28452419Sjulian TQ_LOCK(queue); 28552419Sjulian queue->tq_running = NULL; 28652419Sjulian wakeup(task); 28752419Sjulian } 28852419Sjulian 28952419Sjulian /* 29052419Sjulian * For compatibility, unlock on return if the queue was not locked 29152419Sjulian * on entry, although this opens a race window. 29252419Sjulian */ 29352419Sjulian if (!owned) 29452419Sjulian TQ_UNLOCK(queue); 29552419Sjulian} 29652419Sjulian 29752419Sjulianvoid 29852419Sjuliantaskqueue_drain(struct taskqueue *queue, struct task *task) 29952419Sjulian{ 30052419Sjulian if (queue->tq_spin) { /* XXX */ 30170784Sjulian mtx_lock_spin(&queue->tq_mutex); 30252419Sjulian while (task->ta_pending != 0 || task == queue->tq_running) 30352419Sjulian msleep_spin(task, &queue->tq_mutex, "-", 0); 30452419Sjulian mtx_unlock_spin(&queue->tq_mutex); 30552419Sjulian } else { 30652419Sjulian WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL, __func__); 30752419Sjulian 30852419Sjulian mtx_lock(&queue->tq_mutex); 30952419Sjulian while (task->ta_pending != 0 || task == queue->tq_running) 31052419Sjulian msleep(task, &queue->tq_mutex, PWAIT, "-", 0); 31152419Sjulian mtx_unlock(&queue->tq_mutex); 31252419Sjulian } 31352419Sjulian} 31452419Sjulian 31552419Sjulianstatic void 31652419Sjuliantaskqueue_swi_enqueue(void *context) 31752419Sjulian{ 31852419Sjulian swi_sched(taskqueue_ih, 0); 31952419Sjulian} 32052419Sjulian 32152419Sjulianstatic void 32252419Sjuliantaskqueue_swi_run(void *dummy) 32352419Sjulian{ 32452419Sjulian taskqueue_run(taskqueue_swi); 32552419Sjulian} 32652419Sjulian 32752419Sjulianstatic void 32870700Sjuliantaskqueue_swi_giant_enqueue(void *context) 32952419Sjulian{ 33070784Sjulian swi_sched(taskqueue_giant_ih, 0); 33152419Sjulian} 33252419Sjulian 33352419Sjulianstatic void 33452419Sjuliantaskqueue_swi_giant_run(void *dummy) 33552419Sjulian{ 33670700Sjulian taskqueue_run(taskqueue_swi_giant); 33752419Sjulian} 33852419Sjulian 33952419Sjulianint 34052419Sjuliantaskqueue_start_threads(struct taskqueue **tqp, int count, int pri, 34152419Sjulian const char *name, ...) 34252419Sjulian{ 34352419Sjulian va_list ap; 34452419Sjulian struct thread *td; 34552419Sjulian struct taskqueue *tq; 34652419Sjulian int i, error; 34770784Sjulian char ktname[MAXCOMLEN]; 34852419Sjulian 34970700Sjulian if (count <= 0) 35052419Sjulian return (EINVAL); 35170784Sjulian 35252419Sjulian tq = *tqp; 35352419Sjulian 35452419Sjulian va_start(ap, name); 35552419Sjulian vsnprintf(ktname, MAXCOMLEN, name, ap); 35652419Sjulian va_end(ap); 35752419Sjulian 35852419Sjulian tq->tq_threads = malloc(sizeof(struct thread *) * count, M_TASKQUEUE, 35952419Sjulian M_NOWAIT | M_ZERO); 36052419Sjulian if (tq->tq_threads == NULL) { 36152419Sjulian printf("%s: no memory for %s threads\n", __func__, ktname); 36252419Sjulian return (ENOMEM); 36352419Sjulian } 364111119Simp 36552419Sjulian for (i = 0; i < count; i++) { 36652419Sjulian if (count == 1) 36752419Sjulian error = kthread_add(taskqueue_thread_loop, tqp, NULL, 36852419Sjulian &tq->tq_threads[i], RFSTOPPED, 0, ktname); 36952419Sjulian else 37052419Sjulian error = kthread_add(taskqueue_thread_loop, tqp, NULL, 37152419Sjulian &tq->tq_threads[i], RFSTOPPED, 0, 37252419Sjulian "%s_%d", ktname, i); 37352419Sjulian if (error) { 37452419Sjulian /* should be ok to continue, taskqueue_free will dtrt */ 37552419Sjulian printf("%s: kthread_add(%s): error %d", __func__, 37652419Sjulian ktname, error); 37752419Sjulian tq->tq_threads[i] = NULL; /* paranoid */ 37852419Sjulian } else 37952419Sjulian tq->tq_tcount++; 38052419Sjulian } 38152419Sjulian for (i = 0; i < count; i++) { 38252419Sjulian if (tq->tq_threads[i] == NULL) 38352419Sjulian continue; 38452419Sjulian td = tq->tq_threads[i]; 38552419Sjulian thread_lock(td); 38652419Sjulian sched_prio(td, pri); 38752419Sjulian sched_add(td, SRQ_BORING); 38852419Sjulian thread_unlock(td); 38952419Sjulian } 39052419Sjulian 39152419Sjulian return (0); 39252419Sjulian} 39352419Sjulian 39452419Sjulianvoid 39552419Sjuliantaskqueue_thread_loop(void *arg) 39652419Sjulian{ 39752419Sjulian struct taskqueue **tqp, *tq; 39887599Sobrien 39952419Sjulian tqp = arg; 40052419Sjulian tq = *tqp; 40152419Sjulian TQ_LOCK(tq); 40270700Sjulian while ((tq->tq_flags & TQ_FLAGS_ACTIVE) != 0) { 40352419Sjulian taskqueue_run(tq); 40452419Sjulian TQ_SLEEP(tq, tq, &tq->tq_mutex, 0, "-", 0); 40552419Sjulian }; 40670700Sjulian 40770700Sjulian /* rendezvous with thread that asked us to terminate */ 40852419Sjulian tq->tq_tcount--; 40952419Sjulian wakeup_one(tq->tq_threads); 41052419Sjulian TQ_UNLOCK(tq); 41152419Sjulian kthread_exit(); 41252419Sjulian} 41352419Sjulian 41452419Sjulianvoid 41570700Sjuliantaskqueue_thread_enqueue(void *context) 41652419Sjulian{ 41770784Sjulian struct taskqueue **tqp, *tq; 41852419Sjulian 41952419Sjulian tqp = context; 42052419Sjulian tq = *tqp; 42152419Sjulian 42252419Sjulian mtx_assert(&tq->tq_mutex, MA_OWNED); 42370700Sjulian wakeup_one(tq); 42452419Sjulian} 42570700Sjulian 42652539SjulianTASKQUEUE_DEFINE(swi, taskqueue_swi_enqueue, NULL, 42752419Sjulian swi_add(NULL, "task queue", taskqueue_swi_run, NULL, SWI_TQ, 42852419Sjulian INTR_MPSAFE, &taskqueue_ih)); 42952419Sjulian 43052419SjulianTASKQUEUE_DEFINE(swi_giant, taskqueue_swi_giant_enqueue, NULL, 43152419Sjulian swi_add(NULL, "Giant taskq", taskqueue_swi_giant_run, 43252419Sjulian NULL, SWI_TQ_GIANT, 0, &taskqueue_giant_ih)); 43352419Sjulian 43452419SjulianTASKQUEUE_DEFINE_THREAD(thread); 43552419Sjulian 43652419Sjulianstruct taskqueue * 43752419Sjuliantaskqueue_create_fast(const char *name, int mflags, 43852419Sjulian taskqueue_enqueue_fn enqueue, void *context) 43952419Sjulian{ 44052419Sjulian return _taskqueue_create(name, mflags, enqueue, context, 44152419Sjulian MTX_SPIN, "fast_taskqueue"); 44252419Sjulian} 44352419Sjulian 44452419Sjulian/* NB: for backwards compatibility */ 44552419Sjulianint 44652419Sjuliantaskqueue_enqueue_fast(struct taskqueue *queue, struct task *task) 44752419Sjulian{ 44852419Sjulian return taskqueue_enqueue(queue, task); 44952419Sjulian} 45052419Sjulian 45152419Sjulianstatic void *taskqueue_fast_ih; 45252419Sjulian 45352419Sjulianstatic void 45452419Sjuliantaskqueue_fast_enqueue(void *context) 45552419Sjulian{ 45652419Sjulian swi_sched(taskqueue_fast_ih, 0); 45752419Sjulian} 45852419Sjulian 45952419Sjulianstatic void 46052419Sjuliantaskqueue_fast_run(void *dummy) 46152419Sjulian{ 46252419Sjulian taskqueue_run(taskqueue_fast); 46370700Sjulian} 46452419Sjulian 46552419SjulianTASKQUEUE_FAST_DEFINE(fast, taskqueue_fast_enqueue, NULL, 46652419Sjulian swi_add(NULL, "Fast task queue", taskqueue_fast_run, NULL, 46752419Sjulian SWI_TQ_FAST, INTR_MPSAFE, &taskqueue_fast_ih)); 46852419Sjulian