subr_workqueue.c revision 1.19
1 /* $NetBSD: subr_workqueue.c,v 1.19 2007/08/05 13:47:25 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 1.19 2007/08/05 13:47:25 ad Exp $"); 31 32 #include <sys/param.h> 33 #include <sys/cpu.h> 34 #include <sys/systm.h> 35 #include <sys/kthread.h> 36 #include <sys/kmem.h> 37 #include <sys/proc.h> 38 #include <sys/workqueue.h> 39 #include <sys/mutex.h> 40 #include <sys/condvar.h> 41 #include <sys/queue.h> 42 43 typedef struct work_impl { 44 SIMPLEQ_ENTRY(work_impl) wk_entry; 45 } work_impl_t; 46 47 SIMPLEQ_HEAD(workqhead, work_impl); 48 49 struct workqueue_queue { 50 kmutex_t q_mutex; 51 kcondvar_t q_cv; 52 struct workqhead q_queue; 53 struct lwp *q_worker; 54 SLIST_ENTRY(workqueue_queue) q_list; 55 }; 56 57 struct workqueue { 58 void (*wq_func)(struct work *, void *); 59 void *wq_arg; 60 const char *wq_name; 61 pri_t wq_prio; 62 int wq_flags; 63 void *wq_ptr; 64 ipl_cookie_t wq_ipl; 65 }; 66 67 #ifdef MULTIPROCESSOR 68 #define CPU_ALIGN_SIZE CACHE_LINE_SIZE 69 #else 70 #define CPU_ALIGN_SIZE (ALIGNBYTES + 1) 71 #endif 72 73 #define WQ_SIZE (roundup2(sizeof(struct workqueue), CPU_ALIGN_SIZE)) 74 #define WQ_QUEUE_SIZE (roundup2(sizeof(struct workqueue_queue), CPU_ALIGN_SIZE)) 75 76 #define POISON 0xaabbccdd 77 78 static struct workqueue_queue * 79 workqueue_queue_lookup(struct workqueue *wq, struct cpu_info *ci) 80 { 81 u_int idx = 0; 82 83 if (wq->wq_flags & WQ_PERCPU) { 84 idx = ci ? cpu_index(ci) : cpu_index(curcpu()); 85 } 86 87 return (void *)((intptr_t)(wq) + WQ_SIZE + (idx * WQ_QUEUE_SIZE)); 88 } 89 90 static void 91 workqueue_runlist(struct workqueue *wq, struct workqhead *list) 92 { 93 work_impl_t *wk; 94 work_impl_t *next; 95 96 /* 97 * note that "list" is not a complete SIMPLEQ. 98 */ 99 100 for (wk = SIMPLEQ_FIRST(list); wk != NULL; wk = next) { 101 next = SIMPLEQ_NEXT(wk, wk_entry); 102 (*wq->wq_func)((void *)wk, wq->wq_arg); 103 } 104 } 105 106 static void 107 workqueue_run(struct workqueue *wq) 108 { 109 struct workqueue_queue *q; 110 111 /* find the workqueue of this kthread */ 112 q = workqueue_queue_lookup(wq, curlwp->l_cpu); 113 114 for (;;) { 115 struct workqhead tmp; 116 117 /* 118 * we violate abstraction of SIMPLEQ. 119 */ 120 121 #if defined(DIAGNOSTIC) 122 tmp.sqh_last = (void *)POISON; 123 #endif /* defined(DIAGNOSTIC) */ 124 125 mutex_enter(&q->q_mutex); 126 while (SIMPLEQ_EMPTY(&q->q_queue)) 127 cv_wait(&q->q_cv, &q->q_mutex); 128 tmp.sqh_first = q->q_queue.sqh_first; /* XXX */ 129 SIMPLEQ_INIT(&q->q_queue); 130 mutex_exit(&q->q_mutex); 131 132 workqueue_runlist(wq, &tmp); 133 } 134 } 135 136 static void 137 workqueue_worker(void *arg) 138 { 139 struct workqueue *wq = arg; 140 struct lwp *l; 141 142 l = curlwp; 143 lwp_lock(l); 144 l->l_priority = wq->wq_prio; 145 l->l_usrpri = wq->wq_prio; 146 lwp_unlock(l); 147 148 workqueue_run(wq); 149 } 150 151 static void 152 workqueue_init(struct workqueue *wq, const char *name, 153 void (*callback_func)(struct work *, void *), void *callback_arg, 154 pri_t prio, int ipl) 155 { 156 157 wq->wq_ipl = makeiplcookie(ipl); 158 wq->wq_prio = prio; 159 wq->wq_name = name; 160 wq->wq_func = callback_func; 161 wq->wq_arg = callback_arg; 162 } 163 164 static int 165 workqueue_initqueue(struct workqueue *wq, struct workqueue_queue *q, 166 int ipl, struct cpu_info *ci) 167 { 168 int error, ktf; 169 170 mutex_init(&q->q_mutex, MUTEX_DRIVER, ipl); 171 cv_init(&q->q_cv, wq->wq_name); 172 q->q_worker = NULL; 173 SIMPLEQ_INIT(&q->q_queue); 174 ktf = ((wq->wq_flags & WQ_MPSAFE) != 0 ? KTHREAD_MPSAFE : 0); 175 if (ci) { 176 error = kthread_create(wq->wq_prio, ktf, ci, workqueue_worker, 177 wq, &q->q_worker, "%s/%u", wq->wq_name, (u_int)ci->ci_cpuid); 178 } else { 179 error = kthread_create(wq->wq_prio, ktf, ci, workqueue_worker, 180 wq, &q->q_worker, "%s", wq->wq_name); 181 } 182 183 return error; 184 } 185 186 struct workqueue_exitargs { 187 work_impl_t wqe_wk; 188 struct workqueue_queue *wqe_q; 189 }; 190 191 static void 192 workqueue_exit(struct work *wk, void *arg) 193 { 194 struct workqueue_exitargs *wqe = (void *)wk; 195 struct workqueue_queue *q = wqe->wqe_q; 196 197 /* 198 * only competition at this point is workqueue_finiqueue. 199 */ 200 201 KASSERT(q->q_worker == curlwp); 202 mutex_enter(&q->q_mutex); 203 q->q_worker = NULL; 204 cv_signal(&q->q_cv); 205 mutex_exit(&q->q_mutex); 206 kthread_exit(0); 207 } 208 209 static void 210 workqueue_finiqueue(struct workqueue *wq, struct workqueue_queue *q) 211 { 212 struct workqueue_exitargs wqe; 213 214 wq->wq_func = workqueue_exit; 215 216 wqe.wqe_q = q; 217 KASSERT(SIMPLEQ_EMPTY(&q->q_queue)); 218 KASSERT(q->q_worker != NULL); 219 mutex_enter(&q->q_mutex); 220 SIMPLEQ_INSERT_TAIL(&q->q_queue, &wqe.wqe_wk, wk_entry); 221 cv_signal(&q->q_cv); 222 while (q->q_worker != NULL) { 223 cv_wait(&q->q_cv, &q->q_mutex); 224 } 225 mutex_exit(&q->q_mutex); 226 mutex_destroy(&q->q_mutex); 227 cv_destroy(&q->q_cv); 228 } 229 230 /* --- */ 231 232 int 233 workqueue_create(struct workqueue **wqp, const char *name, 234 void (*callback_func)(struct work *, void *), void *callback_arg, 235 pri_t prio, int ipl, int flags) 236 { 237 struct workqueue *wq; 238 struct workqueue_queue *q; 239 void *ptr; 240 int i, error = 0; 241 size_t size; 242 243 KASSERT(sizeof(work_impl_t) <= sizeof(struct work)); 244 245 i = (flags & WQ_PERCPU) ? ncpu : 1; 246 if (ncpu == 1) { 247 flags &= ~WQ_PERCPU; 248 } 249 250 size = WQ_SIZE + (i * WQ_QUEUE_SIZE) + CPU_ALIGN_SIZE; 251 ptr = kmem_alloc(size, KM_SLEEP); 252 253 wq = (void *)roundup2((intptr_t)ptr, CPU_ALIGN_SIZE); 254 wq->wq_ptr = ptr; 255 wq->wq_flags = flags; 256 q = (void *)((intptr_t)(wq) + WQ_SIZE); 257 258 workqueue_init(wq, name, callback_func, callback_arg, prio, ipl); 259 i = 0; 260 261 if (flags & WQ_PERCPU) { 262 #ifdef MULTIPROCESSOR 263 struct cpu_info *ci; 264 CPU_INFO_ITERATOR cii; 265 266 /* create the work-queue for each CPU */ 267 for (CPU_INFO_FOREACH(cii, ci)) { 268 error = workqueue_initqueue(wq, q, ipl, ci); 269 if (error) { 270 break; 271 } 272 q = (void *)((intptr_t)(q) + WQ_QUEUE_SIZE); 273 i++; 274 } 275 #endif 276 } else { 277 /* initialize a work-queue */ 278 error = workqueue_initqueue(wq, q, ipl, NULL); 279 } 280 281 if (error) { 282 /* 283 * workqueue_finiqueue() should be 284 * called for the failing one too. 285 */ 286 do { 287 workqueue_finiqueue(wq, q); 288 q = (void *)((intptr_t)(q) - WQ_QUEUE_SIZE); 289 } while(i--); 290 kmem_free(ptr, size); 291 return error; 292 } 293 294 *wqp = wq; 295 return 0; 296 } 297 298 void 299 workqueue_destroy(struct workqueue *wq) 300 { 301 struct workqueue_queue *q; 302 u_int i = 1; 303 304 if (wq->wq_flags & WQ_PERCPU) { 305 #ifdef MULTIPROCESSOR 306 struct cpu_info *ci; 307 CPU_INFO_ITERATOR cii; 308 309 for (CPU_INFO_FOREACH(cii, ci)) { 310 q = workqueue_queue_lookup(wq, ci); 311 workqueue_finiqueue(wq, q); 312 } 313 i = ncpu; 314 #endif 315 } else { 316 q = workqueue_queue_lookup(wq, NULL); 317 workqueue_finiqueue(wq, q); 318 } 319 320 kmem_free(wq->wq_ptr, WQ_SIZE + (i * WQ_QUEUE_SIZE) + CPU_ALIGN_SIZE); 321 } 322 323 void 324 workqueue_enqueue(struct workqueue *wq, struct work *wk0, struct cpu_info *ci) 325 { 326 struct workqueue_queue *q; 327 work_impl_t *wk = (void *)wk0; 328 329 KASSERT(wq->wq_flags & WQ_PERCPU || ci == NULL); 330 q = workqueue_queue_lookup(wq, ci); 331 332 mutex_enter(&q->q_mutex); 333 SIMPLEQ_INSERT_TAIL(&q->q_queue, wk, wk_entry); 334 cv_signal(&q->q_cv); 335 mutex_exit(&q->q_mutex); 336 } 337
Indexes created Tue Sep 23 14:10:03 GMT 2025