sys/kern/subr_taskqueue.c

   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("$FreeBSD$");
  29
  30 #include <sys/param.h>
  31 #include <sys/systm.h>
  32 #include <sys/bus.h>
  33 #include <sys/interrupt.h>
  34 #include <sys/kernel.h>
  35 #include <sys/kthread.h>
  36 #include <sys/limits.h>
  37 #include <sys/lock.h>
  38 #include <sys/malloc.h>
  39 #include <sys/mutex.h>
  40 #include <sys/proc.h>
  41 #include <sys/sched.h>
  42 #include <sys/taskqueue.h>
  43 #include <sys/unistd.h>
  44 #include <machine/stdarg.h>
  45
  46 static MALLOC_DEFINE(M_TASKQUEUE, "taskqueue", "Task Queues");
  47 static void     *taskqueue_giant_ih;
  48 static void     *taskqueue_ih;
  49
  50 struct taskqueue_busy {
  51         struct task     *tb_running;
  52         TAILQ_ENTRY(taskqueue_busy) tb_link;
  53 };
  54
  55 struct taskqueue {
  56         STAILQ_HEAD(, task)     tq_queue;
  57         taskqueue_enqueue_fn    tq_enqueue;
  58         void                    *tq_context;
  59         TAILQ_HEAD(, taskqueue_busy) tq_active;
  60         struct mtx              tq_mutex;
  61         struct thread           **tq_threads;
  62         int                     tq_tcount;
  63         int                     tq_spin;
  64         int                     tq_flags;
  65         int                     tq_callouts;
  66         taskqueue_callback_fn   tq_callbacks[TASKQUEUE_NUM_CALLBACKS];
  67         void                    *tq_cb_contexts[TASKQUEUE_NUM_CALLBACKS];
  68 };
  69
  70 #define TQ_FLAGS_ACTIVE         (1 << 0)
  71 #define TQ_FLAGS_BLOCKED        (1 << 1)
  72 #define TQ_FLAGS_PENDING        (1 << 2)
  73
  74 #define DT_CALLOUT_ARMED        (1 << 0)
  75
  76 #define TQ_LOCK(tq)                                                     \
  77         do {                                                            \
  78                 if ((tq)->tq_spin)                                      \
  79                         mtx_lock_spin(&(tq)->tq_mutex);                 \
  80                 else                                                    \
  81                         mtx_lock(&(tq)->tq_mutex);                      \
  82         } while (0)
  83 #define TQ_ASSERT_LOCKED(tq)    mtx_assert(&(tq)->tq_mutex, MA_OWNED)
  84
  85 #define TQ_UNLOCK(tq)                                                   \
  86         do {                                                            \
  87                 if ((tq)->tq_spin)                                      \
  88                         mtx_unlock_spin(&(tq)->tq_mutex);               \
  89                 else                                                    \
  90                         mtx_unlock(&(tq)->tq_mutex);                    \
  91         } while (0)
  92 #define TQ_ASSERT_UNLOCKED(tq)  mtx_assert(&(tq)->tq_mutex, MA_NOTOWNED)
  93
  94 void
  95 _timeout_task_init(struct taskqueue *queue, struct timeout_task *timeout_task,
  96     int priority, task_fn_t func, void *context)
  97 {
  98
  99         TASK_INIT(&timeout_task->t, priority, func, context);
 100         callout_init_mtx(&timeout_task->c, &queue->tq_mutex, 0);
 101         timeout_task->q = queue;
 102         timeout_task->f = 0;
 103 }
 104
 105 static __inline int
 106 TQ_SLEEP(struct taskqueue *tq, void *p, struct mtx *m, int pri, const char *wm,
 107     int t)
 108 {
 109         if (tq->tq_spin)
 110                 return (msleep_spin(p, m, wm, t));
 111         return (msleep(p, m, pri, wm, t));
 112 }
 113
 114 static struct taskqueue *
 115 _taskqueue_create(const char *name __unused, int mflags,
 116                  taskqueue_enqueue_fn enqueue, void *context,
 117                  int mtxflags, const char *mtxname)
 118 {
 119         struct taskqueue *queue;
 120
 121         queue = malloc(sizeof(struct taskqueue), M_TASKQUEUE, mflags | M_ZERO);
 122         if (!queue)
 123                 return NULL;
 124
 125         STAILQ_INIT(&queue->tq_queue);
 126         TAILQ_INIT(&queue->tq_active);
 127         queue->tq_enqueue = enqueue;
 128         queue->tq_context = context;
 129         queue->tq_spin = (mtxflags & MTX_SPIN) != 0;
 130         queue->tq_flags |= TQ_FLAGS_ACTIVE;
 131         mtx_init(&queue->tq_mutex, mtxname, NULL, mtxflags);
 132
 133         return queue;
 134 }
 135
 136 struct taskqueue *
 137 taskqueue_create(const char *name, int mflags,
 138                  taskqueue_enqueue_fn enqueue, void *context)
 139 {
 140         return _taskqueue_create(name, mflags, enqueue, context,
 141                         MTX_DEF, "taskqueue");
 142 }
 143
 144 void
 145 taskqueue_set_callback(struct taskqueue *queue,
 146     enum taskqueue_callback_type cb_type, taskqueue_callback_fn callback,
 147     void *context)
 148 {
 149
 150         KASSERT(((cb_type >= TASKQUEUE_CALLBACK_TYPE_MIN) &&
 151             (cb_type <= TASKQUEUE_CALLBACK_TYPE_MAX)),
 152             ("Callback type %d not valid, must be %d-%d", cb_type,
 153             TASKQUEUE_CALLBACK_TYPE_MIN, TASKQUEUE_CALLBACK_TYPE_MAX));
 154         KASSERT((queue->tq_callbacks[cb_type] == NULL),
 155             ("Re-initialization of taskqueue callback?"));
 156
 157         queue->tq_callbacks[cb_type] = callback;
 158         queue->tq_cb_contexts[cb_type] = context;
 159 }
 160
 161 /*
 162  * Signal a taskqueue thread to terminate.
 163  */
 164 static void
 165 taskqueue_terminate(struct thread **pp, struct taskqueue *tq)
 166 {
 167
 168         while (tq->tq_tcount > 0 || tq->tq_callouts > 0) {
 169                 wakeup(tq);
 170                 TQ_SLEEP(tq, pp, &tq->tq_mutex, PWAIT, "taskqueue_destroy", 0);
 171         }
 172 }
 173
 174 void
 175 taskqueue_free(struct taskqueue *queue)
 176 {
 177
 178         TQ_LOCK(queue);
 179         queue->tq_flags &= ~TQ_FLAGS_ACTIVE;
 180         taskqueue_terminate(queue->tq_threads, queue);
 181         KASSERT(TAILQ_EMPTY(&queue->tq_active), ("Tasks still running?"));
 182         KASSERT(queue->tq_callouts == 0, ("Armed timeout tasks"));
 183         mtx_destroy(&queue->tq_mutex);
 184         free(queue->tq_threads, M_TASKQUEUE);
 185         free(queue, M_TASKQUEUE);
 186 }
 187
 188 static int
 189 taskqueue_enqueue_locked(struct taskqueue *queue, struct task *task)
 190 {
 191         struct task *ins;
 192         struct task *prev;
 193
 194         /*
 195          * Count multiple enqueues.
 196          */
 197         if (task->ta_pending) {
 198                 if (task->ta_pending < USHRT_MAX)
 199                         task->ta_pending++;
 200                 return (0);
 201         }
 202
 203         /*
 204          * Optimise the case when all tasks have the same priority.
 205          */
 206         prev = STAILQ_LAST(&queue->tq_queue, task, ta_link);
 207         if (!prev || prev->ta_priority >= task->ta_priority) {
 208                 STAILQ_INSERT_TAIL(&queue->tq_queue, task, ta_link);
 209         } else {
 210                 prev = NULL;
 211                 for (ins = STAILQ_FIRST(&queue->tq_queue); ins;
 212                      prev = ins, ins = STAILQ_NEXT(ins, ta_link))
 213                         if (ins->ta_priority < task->ta_priority)
 214                                 break;
 215
 216                 if (prev)
 217                         STAILQ_INSERT_AFTER(&queue->tq_queue, prev, task, ta_link);
 218                 else
 219                         STAILQ_INSERT_HEAD(&queue->tq_queue, task, ta_link);
 220         }
 221
 222         task->ta_pending = 1;
 223         if ((queue->tq_flags & TQ_FLAGS_BLOCKED) == 0)
 224                 queue->tq_enqueue(queue->tq_context);
 225         else
 226                 queue->tq_flags |= TQ_FLAGS_PENDING;
 227
 228         return (0);
 229 }
 230 int
 231 taskqueue_enqueue(struct taskqueue *queue, struct task *task)
 232 {
 233         int res;
 234
 235         TQ_LOCK(queue);
 236         res = taskqueue_enqueue_locked(queue, task);
 237         TQ_UNLOCK(queue);
 238
 239         return (res);
 240 }
 241
 242 static void
 243 taskqueue_timeout_func(void *arg)
 244 {
 245         struct taskqueue *queue;
 246         struct timeout_task *timeout_task;
 247
 248         timeout_task = arg;
 249         queue = timeout_task->q;
 250         KASSERT((timeout_task->f & DT_CALLOUT_ARMED) != 0, ("Stray timeout"));
 251         timeout_task->f &= ~DT_CALLOUT_ARMED;
 252         queue->tq_callouts--;
 253         taskqueue_enqueue_locked(timeout_task->q, &timeout_task->t);
 254 }
 255
 256 int
 257 taskqueue_enqueue_timeout(struct taskqueue *queue,
 258     struct timeout_task *timeout_task, int ticks)
 259 {
 260         int res;
 261
 262         TQ_LOCK(queue);
 263         KASSERT(timeout_task->q == NULL || timeout_task->q == queue,
 264             ("Migrated queue"));
 265         KASSERT(!queue->tq_spin, ("Timeout for spin-queue"));
 266         timeout_task->q = queue;
 267         res = timeout_task->t.ta_pending;
 268         if (ticks == 0) {
 269                 taskqueue_enqueue_locked(queue, &timeout_task->t);
 270         } else {
 271                 if ((timeout_task->f & DT_CALLOUT_ARMED) != 0) {
 272                         res++;
 273                 } else {
 274                         queue->tq_callouts++;
 275                         timeout_task->f |= DT_CALLOUT_ARMED;
 276                         if (ticks < 0)
 277                                 ticks = -ticks; /* Ignore overflow. */
 278                 }
 279                 if (ticks > 0) {
 280                         callout_reset(&timeout_task->c, ticks,
 281                             taskqueue_timeout_func, timeout_task);
 282                 }
 283         }
 284         TQ_UNLOCK(queue);
 285         return (res);
 286 }
 287
 288 static void
 289 taskqueue_drain_running(struct taskqueue *queue)
 290 {
 291
 292         while (!TAILQ_EMPTY(&queue->tq_active))
 293                 TQ_SLEEP(queue, &queue->tq_active, &queue->tq_mutex,
 294                     PWAIT, "-", 0);
 295 }
 296
 297 void
 298 taskqueue_block(struct taskqueue *queue)
 299 {
 300
 301         TQ_LOCK(queue);
 302         queue->tq_flags |= TQ_FLAGS_BLOCKED;
 303         TQ_UNLOCK(queue);
 304 }
 305
 306 void
 307 taskqueue_unblock(struct taskqueue *queue)
 308 {
 309
 310         TQ_LOCK(queue);
 311         queue->tq_flags &= ~TQ_FLAGS_BLOCKED;
 312         if (queue->tq_flags & TQ_FLAGS_PENDING) {
 313                 queue->tq_flags &= ~TQ_FLAGS_PENDING;
 314                 queue->tq_enqueue(queue->tq_context);
 315         }
 316         TQ_UNLOCK(queue);
 317 }
 318
 319 static void
 320 taskqueue_run_locked(struct taskqueue *queue)
 321 {
 322         struct taskqueue_busy tb;
 323         struct task *task;
 324         int pending;
 325
 326         TQ_ASSERT_LOCKED(queue);
 327         tb.tb_running = NULL;
 328         TAILQ_INSERT_TAIL(&queue->tq_active, &tb, tb_link);
 329
 330         while (STAILQ_FIRST(&queue->tq_queue)) {
 331                 /*
 332                  * Carefully remove the first task from the queue and
 333                  * zero its pending count.
 334                  */
 335                 task = STAILQ_FIRST(&queue->tq_queue);
 336                 STAILQ_REMOVE_HEAD(&queue->tq_queue, ta_link);
 337                 pending = task->ta_pending;
 338                 task->ta_pending = 0;
 339                 tb.tb_running = task;
 340                 TQ_UNLOCK(queue);
 341
 342                 task->ta_func(task->ta_context, pending);
 343
 344                 TQ_LOCK(queue);
 345                 tb.tb_running = NULL;
 346                 wakeup(task);
 347         }
 348         TAILQ_REMOVE(&queue->tq_active, &tb, tb_link);
 349         if (TAILQ_EMPTY(&queue->tq_active))
 350                 wakeup(&queue->tq_active);
 351 }
 352
 353 void
 354 taskqueue_run(struct taskqueue *queue)
 355 {
 356
 357         TQ_LOCK(queue);
 358         taskqueue_run_locked(queue);
 359         TQ_UNLOCK(queue);
 360 }
 361
 362 static int
 363 task_is_running(struct taskqueue *queue, struct task *task)
 364 {
 365         struct taskqueue_busy *tb;
 366
 367         TQ_ASSERT_LOCKED(queue);
 368         TAILQ_FOREACH(tb, &queue->tq_active, tb_link) {
 369                 if (tb->tb_running == task)
 370                         return (1);
 371         }
 372         return (0);
 373 }
 374
 375 static int
 376 taskqueue_cancel_locked(struct taskqueue *queue, struct task *task,
 377     u_int *pendp)
 378 {
 379
 380         if (task->ta_pending > 0)
 381                 STAILQ_REMOVE(&queue->tq_queue, task, task, ta_link);
 382         if (pendp != NULL)
 383                 *pendp = task->ta_pending;
 384         task->ta_pending = 0;
 385         return (task_is_running(queue, task) ? EBUSY : 0);
 386 }
 387
 388 int
 389 taskqueue_cancel(struct taskqueue *queue, struct task *task, u_int *pendp)
 390 {
 391         int error;
 392
 393         TQ_LOCK(queue);
 394         error = taskqueue_cancel_locked(queue, task, pendp);
 395         TQ_UNLOCK(queue);
 396
 397         return (error);
 398 }
 399
 400 int
 401 taskqueue_cancel_timeout(struct taskqueue *queue,
 402     struct timeout_task *timeout_task, u_int *pendp)
 403 {
 404         u_int pending, pending1;
 405         int error;
 406
 407         TQ_LOCK(queue);
 408         pending = !!callout_stop(&timeout_task->c);
 409         error = taskqueue_cancel_locked(queue, &timeout_task->t, &pending1);
 410         if ((timeout_task->f & DT_CALLOUT_ARMED) != 0) {
 411                 timeout_task->f &= ~DT_CALLOUT_ARMED;
 412                 queue->tq_callouts--;
 413         }
 414         TQ_UNLOCK(queue);
 415
 416         if (pendp != NULL)
 417                 *pendp = pending + pending1;
 418         return (error);
 419 }
 420
 421 void
 422 taskqueue_drain(struct taskqueue *queue, struct task *task)
 423 {
 424
 425         if (!queue->tq_spin)
 426                 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL, __func__);
 427
 428         TQ_LOCK(queue);
 429         while (task->ta_pending != 0 || task_is_running(queue, task))
 430                 TQ_SLEEP(queue, task, &queue->tq_mutex, PWAIT, "-", 0);
 431         TQ_UNLOCK(queue);
 432 }
 433
 434 void
 435 taskqueue_drain_all(struct taskqueue *queue)
 436 {
 437         struct task *task;
 438
 439         if (!queue->tq_spin)
 440                 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL, __func__);
 441
 442         TQ_LOCK(queue);
 443         task = STAILQ_LAST(&queue->tq_queue, task, ta_link);
 444         if (task != NULL)
 445                 while (task->ta_pending != 0)
 446                         TQ_SLEEP(queue, task, &queue->tq_mutex, PWAIT, "-", 0);
 447         taskqueue_drain_running(queue);
 448         KASSERT(STAILQ_EMPTY(&queue->tq_queue),
 449             ("taskqueue queue is not empty after draining"));
 450         TQ_UNLOCK(queue);
 451 }
 452
 453 void
 454 taskqueue_drain_timeout(struct taskqueue *queue,
 455     struct timeout_task *timeout_task)
 456 {
 457
 458         callout_drain(&timeout_task->c);
 459         taskqueue_drain(queue, &timeout_task->t);
 460 }
 461
 462 static void
 463 taskqueue_swi_enqueue(void *context)
 464 {
 465         swi_sched(taskqueue_ih, 0);
 466 }
 467
 468 static void
 469 taskqueue_swi_run(void *dummy)
 470 {
 471         taskqueue_run(taskqueue_swi);
 472 }
 473
 474 static void
 475 taskqueue_swi_giant_enqueue(void *context)
 476 {
 477         swi_sched(taskqueue_giant_ih, 0);
 478 }
 479
 480 static void
 481 taskqueue_swi_giant_run(void *dummy)
 482 {
 483         taskqueue_run(taskqueue_swi_giant);
 484 }
 485
 486 int
 487 taskqueue_start_threads(struct taskqueue **tqp, int count, int pri,
 488                         const char *name, ...)
 489 {
 490         va_list ap;
 491         struct thread *td;
 492         struct taskqueue *tq;
 493         int i, error;
 494         char ktname[MAXCOMLEN + 1];
 495
 496         if (count <= 0)
 497                 return (EINVAL);
 498
 499         tq = *tqp;
 500
 501         va_start(ap, name);
 502         vsnprintf(ktname, sizeof(ktname), name, ap);
 503         va_end(ap);
 504
 505         tq->tq_threads = malloc(sizeof(struct thread *) * count, M_TASKQUEUE,
 506             M_NOWAIT | M_ZERO);
 507         if (tq->tq_threads == NULL) {
 508                 printf("%s: no memory for %s threads\n", __func__, ktname);
 509                 return (ENOMEM);
 510         }
 511
 512         for (i = 0; i < count; i++) {
 513                 if (count == 1)
 514                         error = kthread_add(taskqueue_thread_loop, tqp, NULL,
 515                             &tq->tq_threads[i], RFSTOPPED, 0, "%s", ktname);
 516                 else
 517                         error = kthread_add(taskqueue_thread_loop, tqp, NULL,
 518                             &tq->tq_threads[i], RFSTOPPED, 0,
 519                             "%s_%d", ktname, i);
 520                 if (error) {
 521                         /* should be ok to continue, taskqueue_free will dtrt */
 522                         printf("%s: kthread_add(%s): error %d", __func__,
 523                             ktname, error);
 524                         tq->tq_threads[i] = NULL;               /* paranoid */
 525                 } else
 526                         tq->tq_tcount++;
 527         }
 528         for (i = 0; i < count; i++) {
 529                 if (tq->tq_threads[i] == NULL)
 530                         continue;
 531                 td = tq->tq_threads[i];
 532                 thread_lock(td);
 533                 sched_prio(td, pri);
 534                 sched_add(td, SRQ_BORING);
 535                 thread_unlock(td);
 536         }
 537
 538         return (0);
 539 }
 540
 541 static inline void
 542 taskqueue_run_callback(struct taskqueue *tq,
 543     enum taskqueue_callback_type cb_type)
 544 {
 545         taskqueue_callback_fn tq_callback;
 546
 547         TQ_ASSERT_UNLOCKED(tq);
 548         tq_callback = tq->tq_callbacks[cb_type];
 549         if (tq_callback != NULL)
 550                 tq_callback(tq->tq_cb_contexts[cb_type]);
 551 }
 552
 553 void
 554 taskqueue_thread_loop(void *arg)
 555 {
 556         struct taskqueue **tqp, *tq;
 557
 558         tqp = arg;
 559         tq = *tqp;
 560         taskqueue_run_callback(tq, TASKQUEUE_CALLBACK_TYPE_INIT);
 561         TQ_LOCK(tq);
 562         while ((tq->tq_flags & TQ_FLAGS_ACTIVE) != 0) {
 563                 taskqueue_run_locked(tq);
 564                 /*
 565                  * Because taskqueue_run() can drop tq_mutex, we need to
 566                  * check if the TQ_FLAGS_ACTIVE flag wasn't removed in the
 567                  * meantime, which means we missed a wakeup.
 568                  */
 569                 if ((tq->tq_flags & TQ_FLAGS_ACTIVE) == 0)
 570                         break;
 571                 TQ_SLEEP(tq, tq, &tq->tq_mutex, 0, "-", 0);
 572         }
 573         taskqueue_run_locked(tq);
 574
 575         /*
 576          * This thread is on its way out, so just drop the lock temporarily
 577          * in order to call the shutdown callback.  This allows the callback
 578          * to look at the taskqueue, even just before it dies.
 579          */
 580         TQ_UNLOCK(tq);
 581         taskqueue_run_callback(tq, TASKQUEUE_CALLBACK_TYPE_SHUTDOWN);
 582         TQ_LOCK(tq);
 583
 584         /* rendezvous with thread that asked us to terminate */
 585         tq->tq_tcount--;
 586         wakeup_one(tq->tq_threads);
 587         TQ_UNLOCK(tq);
 588         kthread_exit();
 589 }
 590
 591 void
 592 taskqueue_thread_enqueue(void *context)
 593 {
 594         struct taskqueue **tqp, *tq;
 595
 596         tqp = context;
 597         tq = *tqp;
 598
 599         TQ_ASSERT_LOCKED(tq);
 600         wakeup_one(tq);
 601 }
 602
 603 TASKQUEUE_DEFINE(swi, taskqueue_swi_enqueue, NULL,
 604                  swi_add(NULL, "task queue", taskqueue_swi_run, NULL, SWI_TQ,
 605                      INTR_MPSAFE, &taskqueue_ih));
 606
 607 TASKQUEUE_DEFINE(swi_giant, taskqueue_swi_giant_enqueue, NULL,
 608                  swi_add(NULL, "Giant taskq", taskqueue_swi_giant_run,
 609                      NULL, SWI_TQ_GIANT, 0, &taskqueue_giant_ih));
 610
 611 TASKQUEUE_DEFINE_THREAD(thread);
 612
 613 struct taskqueue *
 614 taskqueue_create_fast(const char *name, int mflags,
 615                  taskqueue_enqueue_fn enqueue, void *context)
 616 {
 617         return _taskqueue_create(name, mflags, enqueue, context,
 618                         MTX_SPIN, "fast_taskqueue");
 619 }
 620
 621 /* NB: for backwards compatibility */
 622 int
 623 taskqueue_enqueue_fast(struct taskqueue *queue, struct task *task)
 624 {
 625         return taskqueue_enqueue(queue, task);
 626 }
 627
 628 static void     *taskqueue_fast_ih;
 629
 630 static void
 631 taskqueue_fast_enqueue(void *context)
 632 {
 633         swi_sched(taskqueue_fast_ih, 0);
 634 }
 635
 636 static void
 637 taskqueue_fast_run(void *dummy)
 638 {
 639         taskqueue_run(taskqueue_fast);
 640 }
 641
 642 TASKQUEUE_FAST_DEFINE(fast, taskqueue_fast_enqueue, NULL,
 643         swi_add(NULL, "fast taskq", taskqueue_fast_run, NULL,
 644         SWI_TQ_FAST, INTR_MPSAFE, &taskqueue_fast_ih));
 645
 646 int
 647 taskqueue_member(struct taskqueue *queue, struct thread *td)
 648 {
 649         int i, j, ret = 0;
 650
 651         for (i = 0, j = 0; ; i++) {
 652                 if (queue->tq_threads[i] == NULL)
 653                         continue;
 654                 if (queue->tq_threads[i] == td) {
 655                         ret = 1;
 656                         break;
 657                 }
 658                 if (++j >= queue->tq_tcount)
 659                         break;
 660         }
 661         return (ret);
 662 }