subr_workqueue.c revision 1.17
1 /* $NetBSD: subr_workqueue.c,v 1.17 2007/07/20 12:43:26 yamt 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 1.17 2007/07/20 12:43:26 yamt 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 #include <sys/queue.h> 41 42 typedef struct work_impl { 43 SIMPLEQ_ENTRY(work_impl) wk_entry; 44 } work_impl_t; 45 46 SIMPLEQ_HEAD(workqhead, work_impl); 47 48 struct workqueue_queue { 49 kmutex_t q_mutex; 50 kcondvar_t q_cv; 51 struct workqhead q_queue; 52 struct lwp *q_worker; 53 struct cpu_info *q_ci; 54 SLIST_ENTRY(workqueue_queue) q_list; 55 }; 56 57 struct workqueue { 58 SLIST_HEAD(, workqueue_queue) wq_queue; 59 void (*wq_func)(struct work *, void *); 60 void *wq_arg; 61 const char *wq_name; 62 pri_t wq_prio; 63 ipl_cookie_t wq_ipl; 64 }; 65 66 #define POISON 0xaabbccdd 67 68 static struct workqueue_queue * 69 workqueue_queue_lookup(struct workqueue *wq, struct cpu_info *ci) 70 { 71 struct workqueue_queue *q; 72 73 SLIST_FOREACH(q, &wq->wq_queue, q_list) 74 if (q->q_ci == ci) 75 return q; 76 77 return SLIST_FIRST(&wq->wq_queue); 78 } 79 80 static void 81 workqueue_runlist(struct workqueue *wq, struct workqhead *list) 82 { 83 work_impl_t *wk; 84 work_impl_t *next; 85 86 /* 87 * note that "list" is not a complete SIMPLEQ. 88 */ 89 90 for (wk = SIMPLEQ_FIRST(list); wk != NULL; wk = next) { 91 next = SIMPLEQ_NEXT(wk, wk_entry); 92 (*wq->wq_func)((void *)wk, wq->wq_arg); 93 } 94 } 95 96 static void 97 workqueue_run(struct workqueue *wq) 98 { 99 struct workqueue_queue *q; 100 101 /* find the workqueue of this kthread */ 102 q = workqueue_queue_lookup(wq, curlwp->l_cpu); 103 KASSERT(q != NULL); 104 105 for (;;) { 106 struct workqhead tmp; 107 108 /* 109 * we violate abstraction of SIMPLEQ. 110 */ 111 112 #if defined(DIAGNOSTIC) 113 tmp.sqh_last = (void *)POISON; 114 #endif /* defined(DIAGNOSTIC) */ 115 116 mutex_enter(&q->q_mutex); 117 while (SIMPLEQ_EMPTY(&q->q_queue)) 118 cv_wait(&q->q_cv, &q->q_mutex); 119 tmp.sqh_first = q->q_queue.sqh_first; /* XXX */ 120 SIMPLEQ_INIT(&q->q_queue); 121 mutex_exit(&q->q_mutex); 122 123 workqueue_runlist(wq, &tmp); 124 } 125 } 126 127 static void 128 workqueue_worker(void *arg) 129 { 130 struct workqueue *wq = arg; 131 struct lwp *l; 132 133 l = curlwp; 134 lwp_lock(l); 135 l->l_priority = wq->wq_prio; 136 l->l_usrpri = wq->wq_prio; 137 lwp_unlock(l); 138 139 workqueue_run(wq); 140 } 141 142 static void 143 workqueue_init(struct workqueue *wq, const char *name, 144 void (*callback_func)(struct work *, void *), void *callback_arg, 145 pri_t prio, int ipl) 146 { 147 148 wq->wq_ipl = makeiplcookie(ipl); 149 wq->wq_prio = prio; 150 wq->wq_name = name; 151 wq->wq_func = callback_func; 152 wq->wq_arg = callback_arg; 153 SLIST_INIT(&wq->wq_queue); 154 } 155 156 static int 157 workqueue_initqueue(struct workqueue *wq, int ipl, 158 int flags, struct cpu_info *ci) 159 { 160 struct workqueue_queue *q; 161 int error, ktf; 162 cpuid_t cpuid; 163 164 #ifdef MULTIPROCESSOR 165 cpuid = ci->ci_cpuid; 166 #else 167 cpuid = 0; 168 #endif 169 170 q = kmem_alloc(sizeof(struct workqueue_queue), KM_SLEEP); 171 SLIST_INSERT_HEAD(&wq->wq_queue, q, q_list); 172 q->q_ci = ci; 173 174 mutex_init(&q->q_mutex, MUTEX_DRIVER, ipl); 175 cv_init(&q->q_cv, wq->wq_name); 176 SIMPLEQ_INIT(&q->q_queue); 177 ktf = ((flags & WQ_MPSAFE) != 0 ? KTHREAD_MPSAFE : 0); 178 error = kthread_create(wq->wq_prio, ktf, ci, workqueue_worker, 179 wq, &q->q_worker, "%s/%d", wq->wq_name, (int)cpuid); 180 181 return error; 182 } 183 184 struct workqueue_exitargs { 185 work_impl_t wqe_wk; 186 struct workqueue_queue *wqe_q; 187 }; 188 189 static void 190 workqueue_exit(struct work *wk, void *arg) 191 { 192 struct workqueue_exitargs *wqe = (void *)wk; 193 struct workqueue_queue *q = wqe->wqe_q; 194 195 /* 196 * only competition at this point is workqueue_finiqueue. 197 */ 198 199 KASSERT(q->q_worker == curlwp); 200 mutex_enter(&q->q_mutex); 201 q->q_worker = NULL; 202 cv_signal(&q->q_cv); 203 mutex_exit(&q->q_mutex); 204 kthread_exit(0); 205 } 206 207 static void 208 workqueue_finiqueue(struct workqueue *wq, struct workqueue_queue *q) 209 { 210 struct workqueue_exitargs wqe; 211 212 wq->wq_func = workqueue_exit; 213 214 wqe.wqe_q = q; 215 KASSERT(SIMPLEQ_EMPTY(&q->q_queue)); 216 KASSERT(q->q_worker != NULL); 217 mutex_enter(&q->q_mutex); 218 SIMPLEQ_INSERT_TAIL(&q->q_queue, &wqe.wqe_wk, wk_entry); 219 cv_signal(&q->q_cv); 220 while (q->q_worker != NULL) { 221 cv_wait(&q->q_cv, &q->q_mutex); 222 } 223 mutex_exit(&q->q_mutex); 224 mutex_destroy(&q->q_mutex); 225 cv_destroy(&q->q_cv); 226 kmem_free(q, sizeof(struct workqueue_queue)); 227 } 228 229 /* --- */ 230 231 int 232 workqueue_create(struct workqueue **wqp, const char *name, 233 void (*callback_func)(struct work *, void *), void *callback_arg, 234 pri_t prio, int ipl, int flags) 235 { 236 struct workqueue *wq; 237 int error = 0; 238 239 KASSERT(sizeof(work_impl_t) <= sizeof(struct work)); 240 241 wq = kmem_alloc(sizeof(*wq), KM_SLEEP); 242 243 workqueue_init(wq, name, callback_func, callback_arg, prio, ipl); 244 245 #ifdef MULTIPROCESSOR 246 if (flags & WQ_PERCPU) { 247 struct cpu_info *ci; 248 CPU_INFO_ITERATOR cii; 249 250 /* create the work-queue for each CPU */ 251 for (CPU_INFO_FOREACH(cii, ci)) { 252 error = workqueue_initqueue(wq, ipl, flags, ci); 253 if (error) 254 break; 255 } 256 if (error) 257 workqueue_destroy(wq); 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 } 266 #else 267 error = workqueue_initqueue(wq, ipl, flags, curcpu()); 268 if (error) { 269 kmem_free(wq, sizeof(*wq)); 270 return error; 271 } 272 #endif 273 274 *wqp = wq; 275 return 0; 276 } 277 278 void 279 workqueue_destroy(struct workqueue *wq) 280 { 281 struct workqueue_queue *q; 282 283 while ((q = SLIST_FIRST(&wq->wq_queue)) != NULL) { 284 SLIST_REMOVE_HEAD(&wq->wq_queue, q_list); 285 workqueue_finiqueue(wq, q); 286 } 287 kmem_free(wq, sizeof(*wq)); 288 } 289 290 void 291 workqueue_enqueue(struct workqueue *wq, struct work *wk0, struct cpu_info *ci) 292 { 293 struct workqueue_queue *q; 294 work_impl_t *wk = (void *)wk0; 295 296 q = workqueue_queue_lookup(wq, ci); 297 KASSERT(q != NULL); 298 299 mutex_enter(&q->q_mutex); 300 SIMPLEQ_INSERT_TAIL(&q->q_queue, wk, wk_entry); 301 cv_signal(&q->q_cv); 302 mutex_exit(&q->q_mutex); 303 } 304
Indexes created Tue Sep 23 01:09:51 GMT 2025