1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause 3 * 4 * Copyright (c) 2000 Doug Rabson 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/param.h> 30 #include <sys/systm.h> 31 #include <sys/bus.h> 32 #include <sys/cpuset.h> 33 #include <sys/interrupt.h> 34 #include <sys/kernel.h> 35 #include <sys/kthread.h> 36 #include <sys/libkern.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/epoch.h> 43 #include <sys/sched.h> 44 #include <sys/smp.h> 45 #include <sys/taskqueue.h> 46 #include <sys/unistd.h> 47 #include <machine/stdarg.h> 48 49 static MALLOC_DEFINE(M_TASKQUEUE, "taskqueue", "Task Queues"); 50 static void *taskqueue_giant_ih; 51 static void *taskqueue_ih; 52 static void taskqueue_fast_enqueue(void *); 53 static void taskqueue_swi_enqueue(void *); 54 static void taskqueue_swi_giant_enqueue(void *); 55 56 struct taskqueue_busy { 57 struct task *tb_running; 58 u_int tb_seq; 59 bool tb_canceling; 60 LIST_ENTRY(taskqueue_busy) tb_link; 61 }; 62 63 struct taskqueue { 64 STAILQ_HEAD(, task) tq_queue; 65 LIST_HEAD(, taskqueue_busy) tq_active; 66 struct task *tq_hint; 67 u_int tq_seq; 68 int tq_callouts; 69 struct mtx_padalign tq_mutex; 70 taskqueue_enqueue_fn tq_enqueue; 71 void *tq_context; 72 char *tq_name; 73 struct thread **tq_threads; 74 int tq_tcount; 75 int tq_spin; 76 int tq_flags; 77 taskqueue_callback_fn tq_callbacks[TASKQUEUE_NUM_CALLBACKS]; 78 void *tq_cb_contexts[TASKQUEUE_NUM_CALLBACKS]; 79 }; 80 81 #define TQ_FLAGS_ACTIVE (1 << 0) 82 #define TQ_FLAGS_BLOCKED (1 << 1) 83 #define TQ_FLAGS_UNLOCKED_ENQUEUE (1 << 2) 84 85 #define DT_CALLOUT_ARMED (1 << 0) 86 #define DT_DRAIN_IN_PROGRESS (1 << 1) 87 88 #define TQ_LOCK(tq) \ 89 do { \ 90 if ((tq)->tq_spin) \ 91 mtx_lock_spin(&(tq)->tq_mutex); \ 92 else \ 93 mtx_lock(&(tq)->tq_mutex); \ 94 } while (0) 95 #define TQ_ASSERT_LOCKED(tq) mtx_assert(&(tq)->tq_mutex, MA_OWNED) 96 97 #define TQ_UNLOCK(tq) \ 98 do { \ 99 if ((tq)->tq_spin) \ 100 mtx_unlock_spin(&(tq)->tq_mutex); \ 101 else \ 102 mtx_unlock(&(tq)->tq_mutex); \ 103 } while (0) 104 #define TQ_ASSERT_UNLOCKED(tq) mtx_assert(&(tq)->tq_mutex, MA_NOTOWNED) 105 106 void 107 _timeout_task_init(struct taskqueue *queue, struct timeout_task *timeout_task, 108 int priority, task_fn_t func, void *context) 109 { 110 111 TASK_INIT(&timeout_task->t, priority, func, context); 112 callout_init_mtx(&timeout_task->c, &queue->tq_mutex, 113 CALLOUT_RETURNUNLOCKED); 114 timeout_task->q = queue; 115 timeout_task->f = 0; 116 } 117 118 static __inline int 119 TQ_SLEEP(struct taskqueue *tq, void *p, const char *wm) 120 { 121 if (tq->tq_spin) 122 return (msleep_spin(p, (struct mtx *)&tq->tq_mutex, wm, 0)); 123 return (msleep(p, &tq->tq_mutex, 0, wm, 0)); 124 } 125 126 static struct taskqueue_busy * 127 task_get_busy(struct taskqueue *queue, struct task *task) 128 { 129 struct taskqueue_busy *tb; 130 131 TQ_ASSERT_LOCKED(queue); 132 LIST_FOREACH(tb, &queue->tq_active, tb_link) { 133 if (tb->tb_running == task) 134 return (tb); 135 } 136 return (NULL); 137 } 138 139 static struct taskqueue * 140 _taskqueue_create(const char *name, int mflags, 141 taskqueue_enqueue_fn enqueue, void *context, 142 int mtxflags, const char *mtxname __unused) 143 { 144 struct taskqueue *queue; 145 char *tq_name; 146 147 tq_name = malloc(TASKQUEUE_NAMELEN, M_TASKQUEUE, mflags | M_ZERO); 148 if (tq_name == NULL) 149 return (NULL); 150 151 queue = malloc(sizeof(struct taskqueue), M_TASKQUEUE, mflags | M_ZERO); 152 if (queue == NULL) { 153 free(tq_name, M_TASKQUEUE); 154 return (NULL); 155 } 156 157 snprintf(tq_name, TASKQUEUE_NAMELEN, "%s", (name) ? name : "taskqueue"); 158 159 STAILQ_INIT(&queue->tq_queue); 160 LIST_INIT(&queue->tq_active); 161 queue->tq_enqueue = enqueue; 162 queue->tq_context = context; 163 queue->tq_name = tq_name; 164 queue->tq_spin = (mtxflags & MTX_SPIN) != 0; 165 queue->tq_flags |= TQ_FLAGS_ACTIVE; 166 if (enqueue == taskqueue_fast_enqueue || 167 enqueue == taskqueue_swi_enqueue || 168 enqueue == taskqueue_swi_giant_enqueue || 169 enqueue == taskqueue_thread_enqueue) 170 queue->tq_flags |= TQ_FLAGS_UNLOCKED_ENQUEUE; 171 mtx_init(&queue->tq_mutex, tq_name, NULL, mtxflags); 172 173 return (queue); 174 } 175 176 struct taskqueue * 177 taskqueue_create(const char *name, int mflags, 178 taskqueue_enqueue_fn enqueue, void *context) 179 { 180 181 return _taskqueue_create(name, mflags, enqueue, context, 182 MTX_DEF, name); 183 } 184 185 void 186 taskqueue_set_callback(struct taskqueue *queue, 187 enum taskqueue_callback_type cb_type, taskqueue_callback_fn callback, 188 void *context) 189 { 190 191 KASSERT(((cb_type >= TASKQUEUE_CALLBACK_TYPE_MIN) && 192 (cb_type <= TASKQUEUE_CALLBACK_TYPE_MAX)), 193 ("Callback type %d not valid, must be %d-%d", cb_type, 194 TASKQUEUE_CALLBACK_TYPE_MIN, TASKQUEUE_CALLBACK_TYPE_MAX)); 195 KASSERT((queue->tq_callbacks[cb_type] == NULL), 196 ("Re-initialization of taskqueue callback?")); 197 198 queue->tq_callbacks[cb_type] = callback; 199 queue->tq_cb_contexts[cb_type] = context; 200 } 201 202 /* 203 * Signal a taskqueue thread to terminate. 204 */ 205 static void 206 taskqueue_terminate(struct thread **pp, struct taskqueue *tq) 207 { 208 209 while (tq->tq_tcount > 0 || tq->tq_callouts > 0) { 210 wakeup(tq); 211 TQ_SLEEP(tq, pp, "tq_destroy"); 212 } 213 } 214 215 void 216 taskqueue_free(struct taskqueue *queue) 217 { 218 219 TQ_LOCK(queue); 220 queue->tq_flags &= ~TQ_FLAGS_ACTIVE; 221 taskqueue_terminate(queue->tq_threads, queue); 222 KASSERT(LIST_EMPTY(&queue->tq_active), ("Tasks still running?")); 223 KASSERT(queue->tq_callouts == 0, ("Armed timeout tasks")); 224 mtx_destroy(&queue->tq_mutex); 225 free(queue->tq_threads, M_TASKQUEUE); 226 free(queue->tq_name, M_TASKQUEUE); 227 free(queue, M_TASKQUEUE); 228 } 229 230 static int 231 taskqueue_enqueue_locked(struct taskqueue *queue, struct task *task, int flags) 232 { 233 struct task *ins; 234 struct task *prev; 235 struct taskqueue_busy *tb; 236 237 KASSERT(task->ta_func != NULL, ("enqueueing task with NULL func")); 238 /* 239 * Ignore canceling task if requested. 240 */ 241 if (__predict_false((flags & TASKQUEUE_FAIL_IF_CANCELING) != 0)) { 242 tb = task_get_busy(queue, task); 243 if (tb != NULL && tb->tb_canceling) { 244 TQ_UNLOCK(queue); 245 return (ECANCELED); 246 } 247 } 248 249 /* 250 * Count multiple enqueues. 251 */ 252 if (task->ta_pending) { 253 if (__predict_false((flags & TASKQUEUE_FAIL_IF_PENDING) != 0)) { 254 TQ_UNLOCK(queue); 255 return (EEXIST); 256 } 257 if (task->ta_pending < USHRT_MAX) 258 task->ta_pending++; 259 TQ_UNLOCK(queue); 260 return (0); 261 } 262 263 /* 264 * Optimise cases when all tasks use small set of priorities. 265 * In case of only one priority we always insert at the end. 266 * In case of two tq_hint typically gives the insertion point. 267 * In case of more then two tq_hint should halve the search. 268 */ 269 prev = STAILQ_LAST(&queue->tq_queue, task, ta_link); 270 if (!prev || prev->ta_priority >= task->ta_priority) { 271 STAILQ_INSERT_TAIL(&queue->tq_queue, task, ta_link); 272 } else { 273 prev = queue->tq_hint; 274 if (prev && prev->ta_priority >= task->ta_priority) { 275 ins = STAILQ_NEXT(prev, ta_link); 276 } else { 277 prev = NULL; 278 ins = STAILQ_FIRST(&queue->tq_queue); 279 } 280 for (; ins; prev = ins, ins = STAILQ_NEXT(ins, ta_link)) 281 if (ins->ta_priority < task->ta_priority) 282 break; 283 284 if (prev) { 285 STAILQ_INSERT_AFTER(&queue->tq_queue, prev, task, ta_link); 286 queue->tq_hint = task; 287 } else 288 STAILQ_INSERT_HEAD(&queue->tq_queue, task, ta_link); 289 } 290 291 task->ta_pending = 1; 292 if ((queue->tq_flags & TQ_FLAGS_UNLOCKED_ENQUEUE) != 0) 293 TQ_UNLOCK(queue); 294 if ((queue->tq_flags & TQ_FLAGS_BLOCKED) == 0) 295 queue->tq_enqueue(queue->tq_context); 296 if ((queue->tq_flags & TQ_FLAGS_UNLOCKED_ENQUEUE) == 0) 297 TQ_UNLOCK(queue); 298 299 /* Return with lock released. */ 300 return (0); 301 } 302 303 int 304 taskqueue_enqueue_flags(struct taskqueue *queue, struct task *task, int flags) 305 { 306 int res; 307 308 TQ_LOCK(queue); 309 res = taskqueue_enqueue_locked(queue, task, flags); 310 /* The lock is released inside. */ 311 312 return (res); 313 } 314 315 int 316 taskqueue_enqueue(struct taskqueue *queue, struct task *task) 317 { 318 return (taskqueue_enqueue_flags(queue, task, 0)); 319 } 320 321 static void 322 taskqueue_timeout_func(void *arg) 323 { 324 struct taskqueue *queue; 325 struct timeout_task *timeout_task; 326 327 timeout_task = arg; 328 queue = timeout_task->q; 329 KASSERT((timeout_task->f & DT_CALLOUT_ARMED) != 0, ("Stray timeout")); 330 timeout_task->f &= ~DT_CALLOUT_ARMED; 331 queue->tq_callouts--; 332 taskqueue_enqueue_locked(timeout_task->q, &timeout_task->t, 0); 333 /* The lock is released inside. */ 334 } 335 336 int 337 taskqueue_enqueue_timeout_sbt(struct taskqueue *queue, 338 struct timeout_task *timeout_task, sbintime_t sbt, sbintime_t pr, int flags) 339 { 340 int res; 341 342 TQ_LOCK(queue); 343 KASSERT(timeout_task->q == NULL || timeout_task->q == queue, 344 ("Migrated queue")); 345 timeout_task->q = queue; 346 res = timeout_task->t.ta_pending; 347 if (timeout_task->f & DT_DRAIN_IN_PROGRESS) { 348 /* Do nothing */ 349 TQ_UNLOCK(queue); 350 res = -1; 351 } else if (sbt == 0) { 352 taskqueue_enqueue_locked(queue, &timeout_task->t, 0); 353 /* The lock is released inside. */ 354 } else { 355 if ((timeout_task->f & DT_CALLOUT_ARMED) != 0) { 356 res++; 357 } else { 358 queue->tq_callouts++; 359 timeout_task->f |= DT_CALLOUT_ARMED; 360 if (sbt < 0) 361 sbt = -sbt; /* Ignore overflow. */ 362 } 363 if (sbt > 0) { 364 if (queue->tq_spin) 365 flags |= C_DIRECT_EXEC; 366 if (queue->tq_spin && queue->tq_tcount == 1 && 367 queue->tq_threads[0] == curthread) { 368 callout_reset_sbt_curcpu(&timeout_task->c, sbt, pr, 369 taskqueue_timeout_func, timeout_task, flags); 370 } else { 371 callout_reset_sbt(&timeout_task->c, sbt, pr, 372 taskqueue_timeout_func, timeout_task, flags); 373 } 374 } 375 TQ_UNLOCK(queue); 376 } 377 return (res); 378 } 379 380 int 381 taskqueue_enqueue_timeout(struct taskqueue *queue, 382 struct timeout_task *ttask, int ticks) 383 { 384 385 return (taskqueue_enqueue_timeout_sbt(queue, ttask, ticks * tick_sbt, 386 0, C_HARDCLOCK)); 387 } 388 389 static void 390 taskqueue_task_nop_fn(void *context, int pending) 391 { 392 } 393 394 /* 395 * Block until all currently queued tasks in this taskqueue 396 * have begun execution. Tasks queued during execution of 397 * this function are ignored. 398 */ 399 static int 400 taskqueue_drain_tq_queue(struct taskqueue *queue) 401 { 402 struct task t_barrier; 403 404 if (STAILQ_EMPTY(&queue->tq_queue)) 405 return (0); 406 407 /* 408 * Enqueue our barrier after all current tasks, but with 409 * the highest priority so that newly queued tasks cannot 410 * pass it. Because of the high priority, we can not use 411 * taskqueue_enqueue_locked directly (which drops the lock 412 * anyway) so just insert it at tail while we have the 413 * queue lock. 414 */ 415 TASK_INIT(&t_barrier, UCHAR_MAX, taskqueue_task_nop_fn, &t_barrier); 416 STAILQ_INSERT_TAIL(&queue->tq_queue, &t_barrier, ta_link); 417 queue->tq_hint = &t_barrier; 418 t_barrier.ta_pending = 1; 419 420 /* 421 * Once the barrier has executed, all previously queued tasks 422 * have completed or are currently executing. 423 */ 424 while (t_barrier.ta_pending != 0) 425 TQ_SLEEP(queue, &t_barrier, "tq_qdrain"); 426 return (1); 427 } 428 429 /* 430 * Block until all currently executing tasks for this taskqueue 431 * complete. Tasks that begin execution during the execution 432 * of this function are ignored. 433 */ 434 static int 435 taskqueue_drain_tq_active(struct taskqueue *queue) 436 { 437 struct taskqueue_busy *tb; 438 u_int seq; 439 440 if (LIST_EMPTY(&queue->tq_active)) 441 return (0); 442 443 /* Block taskq_terminate().*/ 444 queue->tq_callouts++; 445 446 /* Wait for any active task with sequence from the past. */ 447 seq = queue->tq_seq; 448 restart: 449 LIST_FOREACH(tb, &queue->tq_active, tb_link) { 450 if ((int)(tb->tb_seq - seq) <= 0) { 451 TQ_SLEEP(queue, tb->tb_running, "tq_adrain"); 452 goto restart; 453 } 454 } 455 456 /* Release taskqueue_terminate(). */ 457 queue->tq_callouts--; 458 if ((queue->tq_flags & TQ_FLAGS_ACTIVE) == 0) 459 wakeup_one(queue->tq_threads); 460 return (1); 461 } 462 463 void 464 taskqueue_block(struct taskqueue *queue) 465 { 466 467 TQ_LOCK(queue); 468 queue->tq_flags |= TQ_FLAGS_BLOCKED; 469 TQ_UNLOCK(queue); 470 } 471 472 void 473 taskqueue_unblock(struct taskqueue *queue) 474 { 475 476 TQ_LOCK(queue); 477 queue->tq_flags &= ~TQ_FLAGS_BLOCKED; 478 if (!STAILQ_EMPTY(&queue->tq_queue)) 479 queue->tq_enqueue(queue->tq_context); 480 TQ_UNLOCK(queue); 481 } 482 483 static void 484 taskqueue_run_locked(struct taskqueue *queue) 485 { 486 struct epoch_tracker et; 487 struct taskqueue_busy tb; 488 struct task *task; 489 bool in_net_epoch; 490 int pending; 491 492 KASSERT(queue != NULL, ("tq is NULL")); 493 TQ_ASSERT_LOCKED(queue); 494 tb.tb_running = NULL; 495 LIST_INSERT_HEAD(&queue->tq_active, &tb, tb_link); 496 in_net_epoch = false; 497 498 while ((task = STAILQ_FIRST(&queue->tq_queue)) != NULL) { 499 STAILQ_REMOVE_HEAD(&queue->tq_queue, ta_link); 500 if (queue->tq_hint == task) 501 queue->tq_hint = NULL; 502 pending = task->ta_pending; 503 task->ta_pending = 0; 504 tb.tb_running = task; 505 tb.tb_seq = ++queue->tq_seq; 506 tb.tb_canceling = false; 507 TQ_UNLOCK(queue); 508 509 KASSERT(task->ta_func != NULL, ("task->ta_func is NULL")); 510 if (!in_net_epoch && TASK_IS_NET(task)) { 511 in_net_epoch = true; 512 NET_EPOCH_ENTER(et); 513 } else if (in_net_epoch && !TASK_IS_NET(task)) { 514 NET_EPOCH_EXIT(et); 515 in_net_epoch = false; 516 } 517 task->ta_func(task->ta_context, pending); 518 519 TQ_LOCK(queue); 520 wakeup(task); 521 } 522 if (in_net_epoch) 523 NET_EPOCH_EXIT(et); 524 LIST_REMOVE(&tb, tb_link); 525 } 526 527 void 528 taskqueue_run(struct taskqueue *queue) 529 { 530 531 TQ_LOCK(queue); 532 taskqueue_run_locked(queue); 533 TQ_UNLOCK(queue); 534 } 535 536 /* 537 * Only use this function in single threaded contexts. It returns 538 * non-zero if the given task is either pending or running. Else the 539 * task is idle and can be queued again or freed. 540 */ 541 int 542 taskqueue_poll_is_busy(struct taskqueue *queue, struct task *task) 543 { 544 int retval; 545 546 TQ_LOCK(queue); 547 retval = task->ta_pending > 0 || task_get_busy(queue, task) != NULL; 548 TQ_UNLOCK(queue); 549 550 return (retval); 551 } 552 553 static int 554 taskqueue_cancel_locked(struct taskqueue *queue, struct task *task, 555 u_int *pendp) 556 { 557 struct taskqueue_busy *tb; 558 int retval = 0; 559 560 if (task->ta_pending > 0) { 561 STAILQ_REMOVE(&queue->tq_queue, task, task, ta_link); 562 if (queue->tq_hint == task) 563 queue->tq_hint = NULL; 564 } 565 if (pendp != NULL) 566 *pendp = task->ta_pending; 567 task->ta_pending = 0; 568 tb = task_get_busy(queue, task); 569 if (tb != NULL) { 570 tb->tb_canceling = true; 571 retval = EBUSY; 572 } 573 574 return (retval); 575 } 576 577 int 578 taskqueue_cancel(struct taskqueue *queue, struct task *task, u_int *pendp) 579 { 580 int error; 581 582 TQ_LOCK(queue); 583 error = taskqueue_cancel_locked(queue, task, pendp); 584 TQ_UNLOCK(queue); 585 586 return (error); 587 } 588 589 int 590 taskqueue_cancel_timeout(struct taskqueue *queue, 591 struct timeout_task *timeout_task, u_int *pendp) 592 { 593 u_int pending, pending1; 594 int error; 595 596 TQ_LOCK(queue); 597 pending = !!(callout_stop(&timeout_task->c) > 0); 598 error = taskqueue_cancel_locked(queue, &timeout_task->t, &pending1); 599 if ((timeout_task->f & DT_CALLOUT_ARMED) != 0) { 600 timeout_task->f &= ~DT_CALLOUT_ARMED; 601 queue->tq_callouts--; 602 } 603 TQ_UNLOCK(queue); 604 605 if (pendp != NULL) 606 *pendp = pending + pending1; 607 return (error); 608 } 609 610 void 611 taskqueue_drain(struct taskqueue *queue, struct task *task) 612 { 613 614 if (!queue->tq_spin) 615 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL, __func__); 616 617 TQ_LOCK(queue); 618 while (task->ta_pending != 0 || task_get_busy(queue, task) != NULL) 619 TQ_SLEEP(queue, task, "tq_drain"); 620 TQ_UNLOCK(queue); 621 } 622 623 void 624 taskqueue_drain_all(struct taskqueue *queue) 625 { 626 627 if (!queue->tq_spin) 628 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL, __func__); 629 630 TQ_LOCK(queue); 631 (void)taskqueue_drain_tq_queue(queue); 632 (void)taskqueue_drain_tq_active(queue); 633 TQ_UNLOCK(queue); 634 } 635 636 void 637 taskqueue_drain_timeout(struct taskqueue *queue, 638 struct timeout_task *timeout_task) 639 { 640 641 /* 642 * Set flag to prevent timer from re-starting during drain: 643 */ 644 TQ_LOCK(queue); 645 KASSERT((timeout_task->f & DT_DRAIN_IN_PROGRESS) == 0, 646 ("Drain already in progress")); 647 timeout_task->f |= DT_DRAIN_IN_PROGRESS; 648 TQ_UNLOCK(queue); 649 650 callout_drain(&timeout_task->c); 651 taskqueue_drain(queue, &timeout_task->t); 652 653 /* 654 * Clear flag to allow timer to re-start: 655 */ 656 TQ_LOCK(queue); 657 timeout_task->f &= ~DT_DRAIN_IN_PROGRESS; 658 TQ_UNLOCK(queue); 659 } 660 661 void 662 taskqueue_quiesce(struct taskqueue *queue) 663 { 664 int ret; 665 666 TQ_LOCK(queue); 667 do { 668 ret = taskqueue_drain_tq_queue(queue); 669 if (ret == 0) 670 ret = taskqueue_drain_tq_active(queue); 671 } while (ret != 0); 672 TQ_UNLOCK(queue); 673 } 674 675 static void 676 taskqueue_swi_enqueue(void *context) 677 { 678 swi_sched(taskqueue_ih, 0); 679 } 680 681 static void 682 taskqueue_swi_run(void *dummy) 683 { 684 taskqueue_run(taskqueue_swi); 685 } 686 687 static void 688 taskqueue_swi_giant_enqueue(void *context) 689 { 690 swi_sched(taskqueue_giant_ih, 0); 691 } 692 693 static void 694 taskqueue_swi_giant_run(void *dummy) 695 { 696 taskqueue_run(taskqueue_swi_giant); 697 } 698 699 static int 700 _taskqueue_start_threads(struct taskqueue **tqp, int count, int pri, 701 cpuset_t *mask, struct proc *p, const char *name, va_list ap) 702 { 703 char ktname[MAXCOMLEN + 1]; 704 struct thread *td; 705 struct taskqueue *tq; 706 int i, error; 707 708 if (count <= 0) 709 return (EINVAL); 710 711 vsnprintf(ktname, sizeof(ktname), name, ap); 712 tq = *tqp; 713 714 tq->tq_threads = malloc(sizeof(struct thread *) * count, M_TASKQUEUE, 715 M_NOWAIT | M_ZERO); 716 if (tq->tq_threads == NULL) { 717 printf("%s: no memory for %s threads\n", __func__, ktname); 718 return (ENOMEM); 719 } 720 721 for (i = 0; i < count; i++) { 722 if (count == 1) 723 error = kthread_add(taskqueue_thread_loop, tqp, p, 724 &tq->tq_threads[i], RFSTOPPED, 0, "%s", ktname); 725 else 726 error = kthread_add(taskqueue_thread_loop, tqp, p, 727 &tq->tq_threads[i], RFSTOPPED, 0, 728 "%s_%d", ktname, i); 729 if (error) { 730 /* should be ok to continue, taskqueue_free will dtrt */ 731 printf("%s: kthread_add(%s): error %d", __func__, 732 ktname, error); 733 tq->tq_threads[i] = NULL; /* paranoid */ 734 } else 735 tq->tq_tcount++; 736 } 737 if (tq->tq_tcount == 0) { 738 free(tq->tq_threads, M_TASKQUEUE); 739 tq->tq_threads = NULL; 740 return (ENOMEM); 741 } 742 for (i = 0; i < count; i++) { 743 if (tq->tq_threads[i] == NULL) 744 continue; 745 td = tq->tq_threads[i]; 746 if (mask) { 747 error = cpuset_setthread(td->td_tid, mask); 748 /* 749 * Failing to pin is rarely an actual fatal error; 750 * it'll just affect performance. 751 */ 752 if (error) 753 printf("%s: curthread=%llu: can't pin; " 754 "error=%d\n", 755 __func__, 756 (unsigned long long) td->td_tid, 757 error); 758 } 759 thread_lock(td); 760 sched_prio(td, pri); 761 sched_add(td, SRQ_BORING); 762 } 763 764 return (0); 765 } 766 767 int 768 taskqueue_start_threads(struct taskqueue **tqp, int count, int pri, 769 const char *name, ...) 770 { 771 va_list ap; 772 int error; 773 774 va_start(ap, name); 775 error = _taskqueue_start_threads(tqp, count, pri, NULL, NULL, name, ap); 776 va_end(ap); 777 return (error); 778 } 779 780 int 781 taskqueue_start_threads_in_proc(struct taskqueue **tqp, int count, int pri, 782 struct proc *proc, const char *name, ...) 783 { 784 va_list ap; 785 int error; 786 787 va_start(ap, name); 788 error = _taskqueue_start_threads(tqp, count, pri, NULL, proc, name, ap); 789 va_end(ap); 790 return (error); 791 } 792 793 int 794 taskqueue_start_threads_cpuset(struct taskqueue **tqp, int count, int pri, 795 cpuset_t *mask, const char *name, ...) 796 { 797 va_list ap; 798 int error; 799 800 va_start(ap, name); 801 error = _taskqueue_start_threads(tqp, count, pri, mask, NULL, name, ap); 802 va_end(ap); 803 return (error); 804 } 805 806 static inline void 807 taskqueue_run_callback(struct taskqueue *tq, 808 enum taskqueue_callback_type cb_type) 809 { 810 taskqueue_callback_fn tq_callback; 811 812 TQ_ASSERT_UNLOCKED(tq); 813 tq_callback = tq->tq_callbacks[cb_type]; 814 if (tq_callback != NULL) 815 tq_callback(tq->tq_cb_contexts[cb_type]); 816 } 817 818 void 819 taskqueue_thread_loop(void *arg) 820 { 821 struct taskqueue **tqp, *tq; 822 823 tqp = arg; 824 tq = *tqp; 825 taskqueue_run_callback(tq, TASKQUEUE_CALLBACK_TYPE_INIT); 826 TQ_LOCK(tq); 827 while ((tq->tq_flags & TQ_FLAGS_ACTIVE) != 0) { 828 /* XXX ? */ 829 taskqueue_run_locked(tq); 830 /* 831 * Because taskqueue_run() can drop tq_mutex, we need to 832 * check if the TQ_FLAGS_ACTIVE flag wasn't removed in the 833 * meantime, which means we missed a wakeup. 834 */ 835 if ((tq->tq_flags & TQ_FLAGS_ACTIVE) == 0) 836 break; 837 TQ_SLEEP(tq, tq, "-"); 838 } 839 taskqueue_run_locked(tq); 840 /* 841 * This thread is on its way out, so just drop the lock temporarily 842 * in order to call the shutdown callback. This allows the callback 843 * to look at the taskqueue, even just before it dies. 844 */ 845 TQ_UNLOCK(tq); 846 taskqueue_run_callback(tq, TASKQUEUE_CALLBACK_TYPE_SHUTDOWN); 847 TQ_LOCK(tq); 848 849 /* rendezvous with thread that asked us to terminate */ 850 tq->tq_tcount--; 851 wakeup_one(tq->tq_threads); 852 TQ_UNLOCK(tq); 853 kthread_exit(); 854 } 855 856 void 857 taskqueue_thread_enqueue(void *context) 858 { 859 struct taskqueue **tqp, *tq; 860 861 tqp = context; 862 tq = *tqp; 863 wakeup_any(tq); 864 } 865 866 TASKQUEUE_DEFINE(swi, taskqueue_swi_enqueue, NULL, 867 swi_add(NULL, "task queue", taskqueue_swi_run, NULL, SWI_TQ, 868 INTR_MPSAFE, &taskqueue_ih)); 869 870 TASKQUEUE_DEFINE(swi_giant, taskqueue_swi_giant_enqueue, NULL, 871 swi_add(NULL, "Giant taskq", taskqueue_swi_giant_run, 872 NULL, SWI_TQ_GIANT, 0, &taskqueue_giant_ih)); 873 874 TASKQUEUE_DEFINE_THREAD(thread); 875 876 struct taskqueue * 877 taskqueue_create_fast(const char *name, int mflags, 878 taskqueue_enqueue_fn enqueue, void *context) 879 { 880 return _taskqueue_create(name, mflags, enqueue, context, 881 MTX_SPIN, "fast_taskqueue"); 882 } 883 884 static void *taskqueue_fast_ih; 885 886 static void 887 taskqueue_fast_enqueue(void *context) 888 { 889 swi_sched(taskqueue_fast_ih, 0); 890 } 891 892 static void 893 taskqueue_fast_run(void *dummy) 894 { 895 taskqueue_run(taskqueue_fast); 896 } 897 898 TASKQUEUE_FAST_DEFINE(fast, taskqueue_fast_enqueue, NULL, 899 swi_add(NULL, "fast taskq", taskqueue_fast_run, NULL, 900 SWI_TQ_FAST, INTR_MPSAFE, &taskqueue_fast_ih)); 901 902 int 903 taskqueue_member(struct taskqueue *queue, struct thread *td) 904 { 905 int i, j, ret = 0; 906 907 for (i = 0, j = 0; ; i++) { 908 if (queue->tq_threads[i] == NULL) 909 continue; 910 if (queue->tq_threads[i] == td) { 911 ret = 1; 912 break; 913 } 914 if (++j >= queue->tq_tcount) 915 break; 916 } 917 return (ret); 918 } 919