subr_taskqueue.c revision 283551
1/*- 2 * Copyright (c) 2000 Doug Rabson 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24 * SUCH DAMAGE. 25 */ 26 27#include <sys/cdefs.h> 28__FBSDID("$FreeBSD: head/sys/kern/subr_taskqueue.c 283551 2015-05-26 01:40:33Z delphij $"); 29 30#include <sys/param.h> 31#include <sys/systm.h> 32#include <sys/bus.h> 33#include <sys/cpuset.h> 34#include <sys/interrupt.h> 35#include <sys/kernel.h> 36#include <sys/kthread.h> 37#include <sys/limits.h> 38#include <sys/lock.h> 39#include <sys/malloc.h> 40#include <sys/mutex.h> 41#include <sys/proc.h> 42#include <sys/sched.h> 43#include <sys/taskqueue.h> 44#include <sys/unistd.h> 45#include <machine/stdarg.h> 46 47static MALLOC_DEFINE(M_TASKQUEUE, "taskqueue", "Task Queues"); 48static void *taskqueue_giant_ih; 49static void *taskqueue_ih; 50static void taskqueue_fast_enqueue(void *); 51static void taskqueue_swi_enqueue(void *); 52static void taskqueue_swi_giant_enqueue(void *); 53 54struct taskqueue_busy { 55 struct task *tb_running; 56 TAILQ_ENTRY(taskqueue_busy) tb_link; 57}; 58 59struct task * const TB_DRAIN_WAITER = (struct task *)0x1; 60 61struct taskqueue { 62 STAILQ_HEAD(, task) tq_queue; 63 taskqueue_enqueue_fn tq_enqueue; 64 void *tq_context; 65 TAILQ_HEAD(, taskqueue_busy) tq_active; 66 struct mtx tq_mutex; 67 struct thread **tq_threads; 68 int tq_tcount; 69 int tq_spin; 70 int tq_flags; 71 int tq_callouts; 72 taskqueue_callback_fn tq_callbacks[TASKQUEUE_NUM_CALLBACKS]; 73 void *tq_cb_contexts[TASKQUEUE_NUM_CALLBACKS]; 74}; 75 76#define TQ_FLAGS_ACTIVE (1 << 0) 77#define TQ_FLAGS_BLOCKED (1 << 1) 78#define TQ_FLAGS_UNLOCKED_ENQUEUE (1 << 2) 79 80#define DT_CALLOUT_ARMED (1 << 0) 81 82#define TQ_LOCK(tq) \ 83 do { \ 84 if ((tq)->tq_spin) \ 85 mtx_lock_spin(&(tq)->tq_mutex); \ 86 else \ 87 mtx_lock(&(tq)->tq_mutex); \ 88 } while (0) 89#define TQ_ASSERT_LOCKED(tq) mtx_assert(&(tq)->tq_mutex, MA_OWNED) 90 91#define TQ_UNLOCK(tq) \ 92 do { \ 93 if ((tq)->tq_spin) \ 94 mtx_unlock_spin(&(tq)->tq_mutex); \ 95 else \ 96 mtx_unlock(&(tq)->tq_mutex); \ 97 } while (0) 98#define TQ_ASSERT_UNLOCKED(tq) mtx_assert(&(tq)->tq_mutex, MA_NOTOWNED) 99 100void 101_timeout_task_init(struct taskqueue *queue, struct timeout_task *timeout_task, 102 int priority, task_fn_t func, void *context) 103{ 104 105 TASK_INIT(&timeout_task->t, priority, func, context); 106 callout_init_mtx(&timeout_task->c, &queue->tq_mutex, 107 CALLOUT_RETURNUNLOCKED); 108 timeout_task->q = queue; 109 timeout_task->f = 0; 110} 111 112static __inline int 113TQ_SLEEP(struct taskqueue *tq, void *p, struct mtx *m, int pri, const char *wm, 114 int t) 115{ 116 if (tq->tq_spin) 117 return (msleep_spin(p, m, wm, t)); 118 return (msleep(p, m, pri, wm, t)); 119} 120 121static struct taskqueue * 122_taskqueue_create(const char *name __unused, int mflags, 123 taskqueue_enqueue_fn enqueue, void *context, 124 int mtxflags, const char *mtxname) 125{ 126 struct taskqueue *queue; 127 128 queue = malloc(sizeof(struct taskqueue), M_TASKQUEUE, mflags | M_ZERO); 129 if (!queue) 130 return NULL; 131 132 STAILQ_INIT(&queue->tq_queue); 133 TAILQ_INIT(&queue->tq_active); 134 queue->tq_enqueue = enqueue; 135 queue->tq_context = context; 136 queue->tq_spin = (mtxflags & MTX_SPIN) != 0; 137 queue->tq_flags |= TQ_FLAGS_ACTIVE; 138 if (enqueue == taskqueue_fast_enqueue || 139 enqueue == taskqueue_swi_enqueue || 140 enqueue == taskqueue_swi_giant_enqueue || 141 enqueue == taskqueue_thread_enqueue) 142 queue->tq_flags |= TQ_FLAGS_UNLOCKED_ENQUEUE; 143 mtx_init(&queue->tq_mutex, mtxname, NULL, mtxflags); 144 145 return queue; 146} 147 148struct taskqueue * 149taskqueue_create(const char *name, int mflags, 150 taskqueue_enqueue_fn enqueue, void *context) 151{ 152 return _taskqueue_create(name, mflags, enqueue, context, 153 MTX_DEF, "taskqueue"); 154} 155 156void 157taskqueue_set_callback(struct taskqueue *queue, 158 enum taskqueue_callback_type cb_type, taskqueue_callback_fn callback, 159 void *context) 160{ 161 162 KASSERT(((cb_type >= TASKQUEUE_CALLBACK_TYPE_MIN) && 163 (cb_type <= TASKQUEUE_CALLBACK_TYPE_MAX)), 164 ("Callback type %d not valid, must be %d-%d", cb_type, 165 TASKQUEUE_CALLBACK_TYPE_MIN, TASKQUEUE_CALLBACK_TYPE_MAX)); 166 KASSERT((queue->tq_callbacks[cb_type] == NULL), 167 ("Re-initialization of taskqueue callback?")); 168 169 queue->tq_callbacks[cb_type] = callback; 170 queue->tq_cb_contexts[cb_type] = context; 171} 172 173/* 174 * Signal a taskqueue thread to terminate. 175 */ 176static void 177taskqueue_terminate(struct thread **pp, struct taskqueue *tq) 178{ 179 180 while (tq->tq_tcount > 0 || tq->tq_callouts > 0) { 181 wakeup(tq); 182 TQ_SLEEP(tq, pp, &tq->tq_mutex, PWAIT, "taskqueue_destroy", 0); 183 } 184} 185 186void 187taskqueue_free(struct taskqueue *queue) 188{ 189 190 TQ_LOCK(queue); 191 queue->tq_flags &= ~TQ_FLAGS_ACTIVE; 192 taskqueue_terminate(queue->tq_threads, queue); 193 KASSERT(TAILQ_EMPTY(&queue->tq_active), ("Tasks still running?")); 194 KASSERT(queue->tq_callouts == 0, ("Armed timeout tasks")); 195 mtx_destroy(&queue->tq_mutex); 196 free(queue->tq_threads, M_TASKQUEUE); 197 free(queue, M_TASKQUEUE); 198} 199 200static int 201taskqueue_enqueue_locked(struct taskqueue *queue, struct task *task) 202{ 203 struct task *ins; 204 struct task *prev; 205 206 /* 207 * Count multiple enqueues. 208 */ 209 if (task->ta_pending) { 210 if (task->ta_pending < USHRT_MAX) 211 task->ta_pending++; 212 TQ_UNLOCK(queue); 213 return (0); 214 } 215 216 /* 217 * Optimise the case when all tasks have the same priority. 218 */ 219 prev = STAILQ_LAST(&queue->tq_queue, task, ta_link); 220 if (!prev || prev->ta_priority >= task->ta_priority) { 221 STAILQ_INSERT_TAIL(&queue->tq_queue, task, ta_link); 222 } else { 223 prev = NULL; 224 for (ins = STAILQ_FIRST(&queue->tq_queue); ins; 225 prev = ins, ins = STAILQ_NEXT(ins, ta_link)) 226 if (ins->ta_priority < task->ta_priority) 227 break; 228 229 if (prev) 230 STAILQ_INSERT_AFTER(&queue->tq_queue, prev, task, ta_link); 231 else 232 STAILQ_INSERT_HEAD(&queue->tq_queue, task, ta_link); 233 } 234 235 task->ta_pending = 1; 236 if ((queue->tq_flags & TQ_FLAGS_UNLOCKED_ENQUEUE) != 0) 237 TQ_UNLOCK(queue); 238 if ((queue->tq_flags & TQ_FLAGS_BLOCKED) == 0) 239 queue->tq_enqueue(queue->tq_context); 240 if ((queue->tq_flags & TQ_FLAGS_UNLOCKED_ENQUEUE) == 0) 241 TQ_UNLOCK(queue); 242 243 /* Return with lock released. */ 244 return (0); 245} 246 247int 248taskqueue_enqueue(struct taskqueue *queue, struct task *task) 249{ 250 int res; 251 252 TQ_LOCK(queue); 253 res = taskqueue_enqueue_locked(queue, task); 254 /* The lock is released inside. */ 255 256 return (res); 257} 258 259static void 260taskqueue_timeout_func(void *arg) 261{ 262 struct taskqueue *queue; 263 struct timeout_task *timeout_task; 264 265 timeout_task = arg; 266 queue = timeout_task->q; 267 KASSERT((timeout_task->f & DT_CALLOUT_ARMED) != 0, ("Stray timeout")); 268 timeout_task->f &= ~DT_CALLOUT_ARMED; 269 queue->tq_callouts--; 270 taskqueue_enqueue_locked(timeout_task->q, &timeout_task->t); 271 /* The lock is released inside. */ 272} 273 274int 275taskqueue_enqueue_timeout(struct taskqueue *queue, 276 struct timeout_task *timeout_task, int ticks) 277{ 278 int res; 279 280 TQ_LOCK(queue); 281 KASSERT(timeout_task->q == NULL || timeout_task->q == queue, 282 ("Migrated queue")); 283 KASSERT(!queue->tq_spin, ("Timeout for spin-queue")); 284 timeout_task->q = queue; 285 res = timeout_task->t.ta_pending; 286 if (ticks == 0) { 287 taskqueue_enqueue_locked(queue, &timeout_task->t); 288 /* The lock is released inside. */ 289 } else { 290 if ((timeout_task->f & DT_CALLOUT_ARMED) != 0) { 291 res++; 292 } else { 293 queue->tq_callouts++; 294 timeout_task->f |= DT_CALLOUT_ARMED; 295 if (ticks < 0) 296 ticks = -ticks; /* Ignore overflow. */ 297 } 298 if (ticks > 0) { 299 callout_reset(&timeout_task->c, ticks, 300 taskqueue_timeout_func, timeout_task); 301 } 302 TQ_UNLOCK(queue); 303 } 304 return (res); 305} 306 307static void 308taskqueue_task_nop_fn(void *context, int pending) 309{ 310} 311 312/* 313 * Block until all currently queued tasks in this taskqueue 314 * have begun execution. Tasks queued during execution of 315 * this function are ignored. 316 */ 317static void 318taskqueue_drain_tq_queue(struct taskqueue *queue) 319{ 320 struct task t_barrier; 321 322 if (STAILQ_EMPTY(&queue->tq_queue)) 323 return; 324 325 /* 326 * Enqueue our barrier after all current tasks, but with 327 * the highest priority so that newly queued tasks cannot 328 * pass it. Because of the high priority, we can not use 329 * taskqueue_enqueue_locked directly (which drops the lock 330 * anyway) so just insert it at tail while we have the 331 * queue lock. 332 */ 333 TASK_INIT(&t_barrier, USHRT_MAX, taskqueue_task_nop_fn, &t_barrier); 334 STAILQ_INSERT_TAIL(&queue->tq_queue, &t_barrier, ta_link); 335 t_barrier.ta_pending = 1; 336 337 /* 338 * Once the barrier has executed, all previously queued tasks 339 * have completed or are currently executing. 340 */ 341 while (t_barrier.ta_pending != 0) 342 TQ_SLEEP(queue, &t_barrier, &queue->tq_mutex, PWAIT, "-", 0); 343} 344 345/* 346 * Block until all currently executing tasks for this taskqueue 347 * complete. Tasks that begin execution during the execution 348 * of this function are ignored. 349 */ 350static void 351taskqueue_drain_tq_active(struct taskqueue *queue) 352{ 353 struct taskqueue_busy tb_marker, *tb_first; 354 355 if (TAILQ_EMPTY(&queue->tq_active)) 356 return; 357 358 /* Block taskq_terminate().*/ 359 queue->tq_callouts++; 360 361 /* 362 * Wait for all currently executing taskqueue threads 363 * to go idle. 364 */ 365 tb_marker.tb_running = TB_DRAIN_WAITER; 366 TAILQ_INSERT_TAIL(&queue->tq_active, &tb_marker, tb_link); 367 while (TAILQ_FIRST(&queue->tq_active) != &tb_marker) 368 TQ_SLEEP(queue, &tb_marker, &queue->tq_mutex, PWAIT, "-", 0); 369 TAILQ_REMOVE(&queue->tq_active, &tb_marker, tb_link); 370 371 /* 372 * Wakeup any other drain waiter that happened to queue up 373 * without any intervening active thread. 374 */ 375 tb_first = TAILQ_FIRST(&queue->tq_active); 376 if (tb_first != NULL && tb_first->tb_running == TB_DRAIN_WAITER) 377 wakeup(tb_first); 378 379 /* Release taskqueue_terminate(). */ 380 queue->tq_callouts--; 381 if ((queue->tq_flags & TQ_FLAGS_ACTIVE) == 0) 382 wakeup_one(queue->tq_threads); 383} 384 385void 386taskqueue_block(struct taskqueue *queue) 387{ 388 389 TQ_LOCK(queue); 390 queue->tq_flags |= TQ_FLAGS_BLOCKED; 391 TQ_UNLOCK(queue); 392} 393 394void 395taskqueue_unblock(struct taskqueue *queue) 396{ 397 398 TQ_LOCK(queue); 399 queue->tq_flags &= ~TQ_FLAGS_BLOCKED; 400 if (!STAILQ_EMPTY(&queue->tq_queue)) 401 queue->tq_enqueue(queue->tq_context); 402 TQ_UNLOCK(queue); 403} 404 405static void 406taskqueue_run_locked(struct taskqueue *queue) 407{ 408 struct taskqueue_busy tb; 409 struct taskqueue_busy *tb_first; 410 struct task *task; 411 int pending; 412 413 TQ_ASSERT_LOCKED(queue); 414 tb.tb_running = NULL; 415 416 while (STAILQ_FIRST(&queue->tq_queue)) { 417 TAILQ_INSERT_TAIL(&queue->tq_active, &tb, tb_link); 418 419 /* 420 * Carefully remove the first task from the queue and 421 * zero its pending count. 422 */ 423 task = STAILQ_FIRST(&queue->tq_queue); 424 STAILQ_REMOVE_HEAD(&queue->tq_queue, ta_link); 425 pending = task->ta_pending; 426 task->ta_pending = 0; 427 tb.tb_running = task; 428 TQ_UNLOCK(queue); 429 430 task->ta_func(task->ta_context, pending); 431 432 TQ_LOCK(queue); 433 tb.tb_running = NULL; 434 wakeup(task); 435 436 TAILQ_REMOVE(&queue->tq_active, &tb, tb_link); 437 tb_first = TAILQ_FIRST(&queue->tq_active); 438 if (tb_first != NULL && 439 tb_first->tb_running == TB_DRAIN_WAITER) 440 wakeup(tb_first); 441 } 442} 443 444void 445taskqueue_run(struct taskqueue *queue) 446{ 447 448 TQ_LOCK(queue); 449 taskqueue_run_locked(queue); 450 TQ_UNLOCK(queue); 451} 452 453static int 454task_is_running(struct taskqueue *queue, struct task *task) 455{ 456 struct taskqueue_busy *tb; 457 458 TQ_ASSERT_LOCKED(queue); 459 TAILQ_FOREACH(tb, &queue->tq_active, tb_link) { 460 if (tb->tb_running == task) 461 return (1); 462 } 463 return (0); 464} 465 466static int 467taskqueue_cancel_locked(struct taskqueue *queue, struct task *task, 468 u_int *pendp) 469{ 470 471 if (task->ta_pending > 0) 472 STAILQ_REMOVE(&queue->tq_queue, task, task, ta_link); 473 if (pendp != NULL) 474 *pendp = task->ta_pending; 475 task->ta_pending = 0; 476 return (task_is_running(queue, task) ? EBUSY : 0); 477} 478 479int 480taskqueue_cancel(struct taskqueue *queue, struct task *task, u_int *pendp) 481{ 482 int error; 483 484 TQ_LOCK(queue); 485 error = taskqueue_cancel_locked(queue, task, pendp); 486 TQ_UNLOCK(queue); 487 488 return (error); 489} 490 491int 492taskqueue_cancel_timeout(struct taskqueue *queue, 493 struct timeout_task *timeout_task, u_int *pendp) 494{ 495 u_int pending, pending1; 496 int error; 497 498 TQ_LOCK(queue); 499 pending = !!callout_stop(&timeout_task->c); 500 error = taskqueue_cancel_locked(queue, &timeout_task->t, &pending1); 501 if ((timeout_task->f & DT_CALLOUT_ARMED) != 0) { 502 timeout_task->f &= ~DT_CALLOUT_ARMED; 503 queue->tq_callouts--; 504 } 505 TQ_UNLOCK(queue); 506 507 if (pendp != NULL) 508 *pendp = pending + pending1; 509 return (error); 510} 511 512void 513taskqueue_drain(struct taskqueue *queue, struct task *task) 514{ 515 516 if (!queue->tq_spin) 517 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL, __func__); 518 519 TQ_LOCK(queue); 520 while (task->ta_pending != 0 || task_is_running(queue, task)) 521 TQ_SLEEP(queue, task, &queue->tq_mutex, PWAIT, "-", 0); 522 TQ_UNLOCK(queue); 523} 524 525void 526taskqueue_drain_all(struct taskqueue *queue) 527{ 528 529 if (!queue->tq_spin) 530 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL, __func__); 531 532 TQ_LOCK(queue); 533 taskqueue_drain_tq_queue(queue); 534 taskqueue_drain_tq_active(queue); 535 TQ_UNLOCK(queue); 536} 537 538void 539taskqueue_drain_timeout(struct taskqueue *queue, 540 struct timeout_task *timeout_task) 541{ 542 543 callout_drain(&timeout_task->c); 544 taskqueue_drain(queue, &timeout_task->t); 545} 546 547static void 548taskqueue_swi_enqueue(void *context) 549{ 550 swi_sched(taskqueue_ih, 0); 551} 552 553static void 554taskqueue_swi_run(void *dummy) 555{ 556 taskqueue_run(taskqueue_swi); 557} 558 559static void 560taskqueue_swi_giant_enqueue(void *context) 561{ 562 swi_sched(taskqueue_giant_ih, 0); 563} 564 565static void 566taskqueue_swi_giant_run(void *dummy) 567{ 568 taskqueue_run(taskqueue_swi_giant); 569} 570 571static int 572_taskqueue_start_threads(struct taskqueue **tqp, int count, int pri, 573 cpuset_t *mask, const char *name, va_list ap) 574{ 575 char ktname[MAXCOMLEN + 1]; 576 struct thread *td; 577 struct taskqueue *tq; 578 int i, error; 579 580 if (count <= 0) 581 return (EINVAL); 582 583 vsnprintf(ktname, sizeof(ktname), name, ap); 584 tq = *tqp; 585 586 tq->tq_threads = malloc(sizeof(struct thread *) * count, M_TASKQUEUE, 587 M_NOWAIT | M_ZERO); 588 if (tq->tq_threads == NULL) { 589 printf("%s: no memory for %s threads\n", __func__, ktname); 590 return (ENOMEM); 591 } 592 593 for (i = 0; i < count; i++) { 594 if (count == 1) 595 error = kthread_add(taskqueue_thread_loop, tqp, NULL, 596 &tq->tq_threads[i], RFSTOPPED, 0, "%s", ktname); 597 else 598 error = kthread_add(taskqueue_thread_loop, tqp, NULL, 599 &tq->tq_threads[i], RFSTOPPED, 0, 600 "%s_%d", ktname, i); 601 if (error) { 602 /* should be ok to continue, taskqueue_free will dtrt */ 603 printf("%s: kthread_add(%s): error %d", __func__, 604 ktname, error); 605 tq->tq_threads[i] = NULL; /* paranoid */ 606 } else 607 tq->tq_tcount++; 608 } 609 for (i = 0; i < count; i++) { 610 if (tq->tq_threads[i] == NULL) 611 continue; 612 td = tq->tq_threads[i]; 613 if (mask) { 614 error = cpuset_setthread(td->td_tid, mask); 615 /* 616 * Failing to pin is rarely an actual fatal error; 617 * it'll just affect performance. 618 */ 619 if (error) 620 printf("%s: curthread=%llu: can't pin; " 621 "error=%d\n", 622 __func__, 623 (unsigned long long) td->td_tid, 624 error); 625 } 626 thread_lock(td); 627 sched_prio(td, pri); 628 sched_add(td, SRQ_BORING); 629 thread_unlock(td); 630 } 631 632 return (0); 633} 634 635int 636taskqueue_start_threads(struct taskqueue **tqp, int count, int pri, 637 const char *name, ...) 638{ 639 va_list ap; 640 int error; 641 642 va_start(ap, name); 643 error = _taskqueue_start_threads(tqp, count, pri, NULL, name, ap); 644 va_end(ap); 645 return (error); 646} 647 648int 649taskqueue_start_threads_cpuset(struct taskqueue **tqp, int count, int pri, 650 cpuset_t *mask, const char *name, ...) 651{ 652 va_list ap; 653 int error; 654 655 va_start(ap, name); 656 error = _taskqueue_start_threads(tqp, count, pri, mask, name, ap); 657 va_end(ap); 658 return (error); 659} 660 661static inline void 662taskqueue_run_callback(struct taskqueue *tq, 663 enum taskqueue_callback_type cb_type) 664{ 665 taskqueue_callback_fn tq_callback; 666 667 TQ_ASSERT_UNLOCKED(tq); 668 tq_callback = tq->tq_callbacks[cb_type]; 669 if (tq_callback != NULL) 670 tq_callback(tq->tq_cb_contexts[cb_type]); 671} 672 673void 674taskqueue_thread_loop(void *arg) 675{ 676 struct taskqueue **tqp, *tq; 677 678 tqp = arg; 679 tq = *tqp; 680 taskqueue_run_callback(tq, TASKQUEUE_CALLBACK_TYPE_INIT); 681 TQ_LOCK(tq); 682 while ((tq->tq_flags & TQ_FLAGS_ACTIVE) != 0) { 683 taskqueue_run_locked(tq); 684 /* 685 * Because taskqueue_run() can drop tq_mutex, we need to 686 * check if the TQ_FLAGS_ACTIVE flag wasn't removed in the 687 * meantime, which means we missed a wakeup. 688 */ 689 if ((tq->tq_flags & TQ_FLAGS_ACTIVE) == 0) 690 break; 691 TQ_SLEEP(tq, tq, &tq->tq_mutex, 0, "-", 0); 692 } 693 taskqueue_run_locked(tq); 694 695 /* 696 * This thread is on its way out, so just drop the lock temporarily 697 * in order to call the shutdown callback. This allows the callback 698 * to look at the taskqueue, even just before it dies. 699 */ 700 TQ_UNLOCK(tq); 701 taskqueue_run_callback(tq, TASKQUEUE_CALLBACK_TYPE_SHUTDOWN); 702 TQ_LOCK(tq); 703 704 /* rendezvous with thread that asked us to terminate */ 705 tq->tq_tcount--; 706 wakeup_one(tq->tq_threads); 707 TQ_UNLOCK(tq); 708 kthread_exit(); 709} 710 711void 712taskqueue_thread_enqueue(void *context) 713{ 714 struct taskqueue **tqp, *tq; 715 716 tqp = context; 717 tq = *tqp; 718 719 wakeup_one(tq); 720} 721 722TASKQUEUE_DEFINE(swi, taskqueue_swi_enqueue, NULL, 723 swi_add(NULL, "task queue", taskqueue_swi_run, NULL, SWI_TQ, 724 INTR_MPSAFE, &taskqueue_ih)); 725 726TASKQUEUE_DEFINE(swi_giant, taskqueue_swi_giant_enqueue, NULL, 727 swi_add(NULL, "Giant taskq", taskqueue_swi_giant_run, 728 NULL, SWI_TQ_GIANT, 0, &taskqueue_giant_ih)); 729 730TASKQUEUE_DEFINE_THREAD(thread); 731 732struct taskqueue * 733taskqueue_create_fast(const char *name, int mflags, 734 taskqueue_enqueue_fn enqueue, void *context) 735{ 736 return _taskqueue_create(name, mflags, enqueue, context, 737 MTX_SPIN, "fast_taskqueue"); 738} 739 740/* NB: for backwards compatibility */ 741int 742taskqueue_enqueue_fast(struct taskqueue *queue, struct task *task) 743{ 744 return taskqueue_enqueue(queue, task); 745} 746 747static void *taskqueue_fast_ih; 748 749static void 750taskqueue_fast_enqueue(void *context) 751{ 752 swi_sched(taskqueue_fast_ih, 0); 753} 754 755static void 756taskqueue_fast_run(void *dummy) 757{ 758 taskqueue_run(taskqueue_fast); 759} 760 761TASKQUEUE_FAST_DEFINE(fast, taskqueue_fast_enqueue, NULL, 762 swi_add(NULL, "fast taskq", taskqueue_fast_run, NULL, 763 SWI_TQ_FAST, INTR_MPSAFE, &taskqueue_fast_ih)); 764 765int 766taskqueue_member(struct taskqueue *queue, struct thread *td) 767{ 768 int i, j, ret = 0; 769 770 for (i = 0, j = 0; ; i++) { 771 if (queue->tq_threads[i] == NULL) 772 continue; 773 if (queue->tq_threads[i] == td) { 774 ret = 1; 775 break; 776 } 777 if (++j >= queue->tq_tcount) 778 break; 779 } 780 return (ret); 781} 782