subr_workqueue.c revision 1.16
1 /* $NetBSD: subr_workqueue.c,v 1.16 2007/07/18 18:17:03 ad Exp $ */ 2 3 /*- 4 * Copyright (c)2002, 2005 YAMAMOTO Takashi, 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26 * SUCH DAMAGE. 27 */ 28 29 #include <sys/cdefs.h> 30 __KERNEL_RCSID(0, "$NetBSD: subr_workqueue.c,v 1.16 2007/07/18 18:17:03 ad Exp $"); 31 32 #include <sys/param.h> 33 #include <sys/systm.h> 34 #include <sys/kthread.h> 35 #include <sys/kmem.h> 36 #include <sys/proc.h> 37 #include <sys/workqueue.h> 38 #include <sys/mutex.h> 39 #include <sys/condvar.h> 40 41 SIMPLEQ_HEAD(workqhead, work); 42 43 struct workqueue_queue { 44 kmutex_t q_mutex; 45 kcondvar_t q_cv; 46 struct workqhead q_queue; 47 struct lwp *q_worker; 48 struct cpu_info *q_ci; 49 SLIST_ENTRY(workqueue_queue) q_list; 50 }; 51 52 struct workqueue { 53 SLIST_HEAD(, workqueue_queue) wq_queue; 54 void (*wq_func)(struct work *, void *); 55 void *wq_arg; 56 const char *wq_name; 57 pri_t wq_prio; 58 ipl_cookie_t wq_ipl; 59 }; 60 61 #define POISON 0xaabbccdd 62 63 static struct workqueue_queue * 64 workqueue_queue_lookup(struct workqueue *wq, struct cpu_info *ci) 65 { 66 struct workqueue_queue *q; 67 68 SLIST_FOREACH(q, &wq->wq_queue, q_list) 69 if (q->q_ci == ci) 70 return q; 71 72 return SLIST_FIRST(&wq->wq_queue); 73 } 74 75 static void 76 workqueue_runlist(struct workqueue *wq, struct workqhead *list) 77 { 78 struct work *wk; 79 struct work *next; 80 81 /* 82 * note that "list" is not a complete SIMPLEQ. 83 */ 84 85 for (wk = SIMPLEQ_FIRST(list); wk != NULL; wk = next) { 86 next = SIMPLEQ_NEXT(wk, wk_entry); 87 (*wq->wq_func)(wk, wq->wq_arg); 88 } 89 } 90 91 static void 92 workqueue_run(struct workqueue *wq) 93 { 94 struct workqueue_queue *q; 95 96 /* find the workqueue of this kthread */ 97 q = workqueue_queue_lookup(wq, curlwp->l_cpu); 98 KASSERT(q != NULL); 99 100 for (;;) { 101 struct workqhead tmp; 102 103 /* 104 * we violate abstraction of SIMPLEQ. 105 */ 106 107 #if defined(DIAGNOSTIC) 108 tmp.sqh_last = (void *)POISON; 109 #endif /* defined(DIAGNOSTIC) */ 110 111 mutex_enter(&q->q_mutex); 112 while (SIMPLEQ_EMPTY(&q->q_queue)) 113 cv_wait(&q->q_cv, &q->q_mutex); 114 tmp.sqh_first = q->q_queue.sqh_first; /* XXX */ 115 SIMPLEQ_INIT(&q->q_queue); 116 mutex_exit(&q->q_mutex); 117 118 workqueue_runlist(wq, &tmp); 119 } 120 } 121 122 static void 123 workqueue_worker(void *arg) 124 { 125 struct workqueue *wq = arg; 126 struct lwp *l; 127 128 l = curlwp; 129 lwp_lock(l); 130 l->l_priority = wq->wq_prio; 131 l->l_usrpri = wq->wq_prio; 132 lwp_unlock(l); 133 134 workqueue_run(wq); 135 } 136 137 static void 138 workqueue_init(struct workqueue *wq, const char *name, 139 void (*callback_func)(struct work *, void *), void *callback_arg, 140 pri_t prio, int ipl) 141 { 142 143 wq->wq_ipl = makeiplcookie(ipl); 144 wq->wq_prio = prio; 145 wq->wq_name = name; 146 wq->wq_func = callback_func; 147 wq->wq_arg = callback_arg; 148 SLIST_INIT(&wq->wq_queue); 149 } 150 151 static int 152 workqueue_initqueue(struct workqueue *wq, int ipl, 153 int flags, struct cpu_info *ci) 154 { 155 struct workqueue_queue *q; 156 int error, ktf; 157 cpuid_t cpuid; 158 159 #ifdef MULTIPROCESSOR 160 cpuid = ci->ci_cpuid; 161 #else 162 cpuid = 0; 163 #endif 164 165 q = kmem_alloc(sizeof(struct workqueue_queue), KM_SLEEP); 166 SLIST_INSERT_HEAD(&wq->wq_queue, q, q_list); 167 q->q_ci = ci; 168 169 mutex_init(&q->q_mutex, MUTEX_DRIVER, ipl); 170 cv_init(&q->q_cv, wq->wq_name); 171 SIMPLEQ_INIT(&q->q_queue); 172 ktf = ((flags & WQ_MPSAFE) != 0 ? KTHREAD_MPSAFE : 0); 173 error = kthread_create(wq->wq_prio, ktf, ci, workqueue_worker, 174 wq, &q->q_worker, "%s/%d", wq->wq_name, (int)cpuid); 175 176 return error; 177 } 178 179 struct workqueue_exitargs { 180 struct work wqe_wk; 181 struct workqueue_queue *wqe_q; 182 }; 183 184 static void 185 workqueue_exit(struct work *wk, void *arg) 186 { 187 struct workqueue_exitargs *wqe = (void *)wk; 188 struct workqueue_queue *q = wqe->wqe_q; 189 190 /* 191 * only competition at this point is workqueue_finiqueue. 192 */ 193 194 KASSERT(q->q_worker == curlwp); 195 mutex_enter(&q->q_mutex); 196 q->q_worker = NULL; 197 cv_signal(&q->q_cv); 198 mutex_exit(&q->q_mutex); 199 kthread_exit(0); 200 } 201 202 static void 203 workqueue_finiqueue(struct workqueue *wq, struct workqueue_queue *q) 204 { 205 struct workqueue_exitargs wqe; 206 207 wq->wq_func = workqueue_exit; 208 209 wqe.wqe_q = q; 210 KASSERT(SIMPLEQ_EMPTY(&q->q_queue)); 211 KASSERT(q->q_worker != NULL); 212 mutex_enter(&q->q_mutex); 213 SIMPLEQ_INSERT_TAIL(&q->q_queue, &wqe.wqe_wk, wk_entry); 214 cv_signal(&q->q_cv); 215 while (q->q_worker != NULL) { 216 cv_wait(&q->q_cv, &q->q_mutex); 217 } 218 mutex_exit(&q->q_mutex); 219 mutex_destroy(&q->q_mutex); 220 cv_destroy(&q->q_cv); 221 kmem_free(q, sizeof(struct workqueue_queue)); 222 } 223 224 /* --- */ 225 226 int 227 workqueue_create(struct workqueue **wqp, const char *name, 228 void (*callback_func)(struct work *, void *), void *callback_arg, 229 pri_t prio, int ipl, int flags) 230 { 231 struct workqueue *wq; 232 int error = 0; 233 234 wq = kmem_alloc(sizeof(*wq), KM_SLEEP); 235 236 workqueue_init(wq, name, callback_func, callback_arg, prio, ipl); 237 238 #ifdef MULTIPROCESSOR 239 if (flags & WQ_PERCPU) { 240 struct cpu_info *ci; 241 CPU_INFO_ITERATOR cii; 242 243 /* create the work-queue for each CPU */ 244 for (CPU_INFO_FOREACH(cii, ci)) { 245 error = workqueue_initqueue(wq, ipl, flags, ci); 246 if (error) 247 break; 248 } 249 if (error) 250 workqueue_destroy(wq); 251 252 } else { 253 error = workqueue_initqueue(wq, ipl, flags, curcpu()); 254 if (error) { 255 kmem_free(wq, sizeof(*wq)); 256 return error; 257 } 258 } 259 #else 260 error = workqueue_initqueue(wq, ipl, flags, curcpu()); 261 if (error) { 262 kmem_free(wq, sizeof(*wq)); 263 return error; 264 } 265 #endif 266 267 *wqp = wq; 268 return 0; 269 } 270 271 void 272 workqueue_destroy(struct workqueue *wq) 273 { 274 struct workqueue_queue *q; 275 276 while ((q = SLIST_FIRST(&wq->wq_queue)) != NULL) { 277 SLIST_REMOVE_HEAD(&wq->wq_queue, q_list); 278 workqueue_finiqueue(wq, q); 279 } 280 kmem_free(wq, sizeof(*wq)); 281 } 282 283 void 284 workqueue_enqueue(struct workqueue *wq, struct work *wk, struct cpu_info *ci) 285 { 286 struct workqueue_queue *q; 287 288 q = workqueue_queue_lookup(wq, ci); 289 KASSERT(q != NULL); 290 291 mutex_enter(&q->q_mutex); 292 SIMPLEQ_INSERT_TAIL(&q->q_queue, wk, wk_entry); 293 cv_signal(&q->q_cv); 294 mutex_exit(&q->q_mutex); 295 } 296
Indexes created Mon Sep 22 21:09:42 GMT 2025