sys/kern/subr_gtaskqueue.c

   1 /*-
   2  * Copyright (c) 2000 Doug Rabson
   3  * Copyright (c) 2014 Jeff Roberson
   4  * Copyright (c) 2016 Matthew Macy
   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/kernel.h>
  34 #include <sys/kthread.h>
  35 #include <sys/libkern.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/epoch.h>
  42 #include <sys/sched.h>
  43 #include <sys/smp.h>
  44 #include <sys/gtaskqueue.h>
  45 #include <sys/unistd.h>
  46 #include <machine/stdarg.h>
  47
  48 static MALLOC_DEFINE(M_GTASKQUEUE, "gtaskqueue", "Group Task Queues");
  49 static void     gtaskqueue_thread_enqueue(void *);
  50 static void     gtaskqueue_thread_loop(void *arg);
  51 static int      task_is_running(struct gtaskqueue *queue, struct gtask *gtask);
  52 static void     gtaskqueue_drain_locked(struct gtaskqueue *queue, struct gtask *gtask);
  53
  54 TASKQGROUP_DEFINE(softirq, mp_ncpus, 1);
  55
  56 struct gtaskqueue_busy {
  57         struct gtask            *tb_running;
  58         u_int                    tb_seq;
  59         LIST_ENTRY(gtaskqueue_busy) tb_link;
  60 };
  61
  62 typedef void (*gtaskqueue_enqueue_fn)(void *context);
  63
  64 struct gtaskqueue {
  65         STAILQ_HEAD(, gtask)    tq_queue;
  66         LIST_HEAD(, gtaskqueue_busy) tq_active;
  67         u_int                   tq_seq;
  68         int                     tq_callouts;
  69         struct mtx_padalign     tq_mutex;
  70         gtaskqueue_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
  87 #define TQ_LOCK(tq)                                                     \
  88         do {                                                            \
  89                 if ((tq)->tq_spin)                                      \
  90                         mtx_lock_spin(&(tq)->tq_mutex);                 \
  91                 else                                                    \
  92                         mtx_lock(&(tq)->tq_mutex);                      \
  93         } while (0)
  94 #define TQ_ASSERT_LOCKED(tq)    mtx_assert(&(tq)->tq_mutex, MA_OWNED)
  95
  96 #define TQ_UNLOCK(tq)                                                   \
  97         do {                                                            \
  98                 if ((tq)->tq_spin)                                      \
  99                         mtx_unlock_spin(&(tq)->tq_mutex);               \
 100                 else                                                    \
 101                         mtx_unlock(&(tq)->tq_mutex);                    \
 102         } while (0)
 103 #define TQ_ASSERT_UNLOCKED(tq)  mtx_assert(&(tq)->tq_mutex, MA_NOTOWNED)
 104
 105 #ifdef INVARIANTS
 106 static void
 107 gtask_dump(struct gtask *gtask)
 108 {
 109         printf("gtask: %p ta_flags=%x ta_priority=%d ta_func=%p ta_context=%p\n",
 110                gtask, gtask->ta_flags, gtask->ta_priority, gtask->ta_func, gtask->ta_context);
 111 }
 112 #endif
 113
 114 static __inline int
 115 TQ_SLEEP(struct gtaskqueue *tq, void *p, const char *wm)
 116 {
 117         if (tq->tq_spin)
 118                 return (msleep_spin(p, (struct mtx *)&tq->tq_mutex, wm, 0));
 119         return (msleep(p, &tq->tq_mutex, 0, wm, 0));
 120 }
 121
 122 static struct gtaskqueue *
 123 _gtaskqueue_create(const char *name, int mflags,
 124                  taskqueue_enqueue_fn enqueue, void *context,
 125                  int mtxflags, const char *mtxname __unused)
 126 {
 127         struct gtaskqueue *queue;
 128         char *tq_name;
 129
 130         tq_name = malloc(TASKQUEUE_NAMELEN, M_GTASKQUEUE, mflags | M_ZERO);
 131         if (!tq_name)
 132                 return (NULL);
 133
 134         snprintf(tq_name, TASKQUEUE_NAMELEN, "%s", (name) ? name : "taskqueue");
 135
 136         queue = malloc(sizeof(struct gtaskqueue), M_GTASKQUEUE, mflags | M_ZERO);
 137         if (!queue) {
 138                 free(tq_name, M_GTASKQUEUE);
 139                 return (NULL);
 140         }
 141
 142         STAILQ_INIT(&queue->tq_queue);
 143         LIST_INIT(&queue->tq_active);
 144         queue->tq_enqueue = enqueue;
 145         queue->tq_context = context;
 146         queue->tq_name = tq_name;
 147         queue->tq_spin = (mtxflags & MTX_SPIN) != 0;
 148         queue->tq_flags |= TQ_FLAGS_ACTIVE;
 149         if (enqueue == gtaskqueue_thread_enqueue)
 150                 queue->tq_flags |= TQ_FLAGS_UNLOCKED_ENQUEUE;
 151         mtx_init(&queue->tq_mutex, tq_name, NULL, mtxflags);
 152
 153         return (queue);
 154 }
 155
 156 /*
 157  * Signal a taskqueue thread to terminate.
 158  */
 159 static void
 160 gtaskqueue_terminate(struct thread **pp, struct gtaskqueue *tq)
 161 {
 162
 163         while (tq->tq_tcount > 0 || tq->tq_callouts > 0) {
 164                 wakeup(tq);
 165                 TQ_SLEEP(tq, pp, "gtq_destroy");
 166         }
 167 }
 168
 169 static void __unused
 170 gtaskqueue_free(struct gtaskqueue *queue)
 171 {
 172
 173         TQ_LOCK(queue);
 174         queue->tq_flags &= ~TQ_FLAGS_ACTIVE;
 175         gtaskqueue_terminate(queue->tq_threads, queue);
 176         KASSERT(LIST_EMPTY(&queue->tq_active), ("Tasks still running?"));
 177         KASSERT(queue->tq_callouts == 0, ("Armed timeout tasks"));
 178         mtx_destroy(&queue->tq_mutex);
 179         free(queue->tq_threads, M_GTASKQUEUE);
 180         free(queue->tq_name, M_GTASKQUEUE);
 181         free(queue, M_GTASKQUEUE);
 182 }
 183
 184 /*
 185  * Wait for all to complete, then prevent it from being enqueued
 186  */
 187 void
 188 grouptask_block(struct grouptask *grouptask)
 189 {
 190         struct gtaskqueue *queue = grouptask->gt_taskqueue;
 191         struct gtask *gtask = &grouptask->gt_task;
 192
 193 #ifdef INVARIANTS
 194         if (queue == NULL) {
 195                 gtask_dump(gtask);
 196                 panic("queue == NULL");
 197         }
 198 #endif
 199         TQ_LOCK(queue);
 200         gtask->ta_flags |= TASK_NOENQUEUE;
 201         gtaskqueue_drain_locked(queue, gtask);
 202         TQ_UNLOCK(queue);
 203 }
 204
 205 void
 206 grouptask_unblock(struct grouptask *grouptask)
 207 {
 208         struct gtaskqueue *queue = grouptask->gt_taskqueue;
 209         struct gtask *gtask = &grouptask->gt_task;
 210
 211 #ifdef INVARIANTS
 212         if (queue == NULL) {
 213                 gtask_dump(gtask);
 214                 panic("queue == NULL");
 215         }
 216 #endif
 217         TQ_LOCK(queue);
 218         gtask->ta_flags &= ~TASK_NOENQUEUE;
 219         TQ_UNLOCK(queue);
 220 }
 221
 222 int
 223 grouptaskqueue_enqueue(struct gtaskqueue *queue, struct gtask *gtask)
 224 {
 225 #ifdef INVARIANTS
 226         if (queue == NULL) {
 227                 gtask_dump(gtask);
 228                 panic("queue == NULL");
 229         }
 230 #endif
 231         TQ_LOCK(queue);
 232         if (gtask->ta_flags & TASK_ENQUEUED) {
 233                 TQ_UNLOCK(queue);
 234                 return (0);
 235         }
 236         if (gtask->ta_flags & TASK_NOENQUEUE) {
 237                 TQ_UNLOCK(queue);
 238                 return (EAGAIN);
 239         }
 240         STAILQ_INSERT_TAIL(&queue->tq_queue, gtask, ta_link);
 241         gtask->ta_flags |= TASK_ENQUEUED;
 242         TQ_UNLOCK(queue);
 243         if ((queue->tq_flags & TQ_FLAGS_BLOCKED) == 0)
 244                 queue->tq_enqueue(queue->tq_context);
 245         return (0);
 246 }
 247
 248 static void
 249 gtaskqueue_task_nop_fn(void *context)
 250 {
 251 }
 252
 253 /*
 254  * Block until all currently queued tasks in this taskqueue
 255  * have begun execution.  Tasks queued during execution of
 256  * this function are ignored.
 257  */
 258 static void
 259 gtaskqueue_drain_tq_queue(struct gtaskqueue *queue)
 260 {
 261         struct gtask t_barrier;
 262
 263         if (STAILQ_EMPTY(&queue->tq_queue))
 264                 return;
 265
 266         /*
 267          * Enqueue our barrier after all current tasks, but with
 268          * the highest priority so that newly queued tasks cannot
 269          * pass it.  Because of the high priority, we can not use
 270          * taskqueue_enqueue_locked directly (which drops the lock
 271          * anyway) so just insert it at tail while we have the
 272          * queue lock.
 273          */
 274         GTASK_INIT(&t_barrier, 0, USHRT_MAX, gtaskqueue_task_nop_fn, &t_barrier);
 275         STAILQ_INSERT_TAIL(&queue->tq_queue, &t_barrier, ta_link);
 276         t_barrier.ta_flags |= TASK_ENQUEUED;
 277
 278         /*
 279          * Once the barrier has executed, all previously queued tasks
 280          * have completed or are currently executing.
 281          */
 282         while (t_barrier.ta_flags & TASK_ENQUEUED)
 283                 TQ_SLEEP(queue, &t_barrier, "gtq_qdrain");
 284 }
 285
 286 /*
 287  * Block until all currently executing tasks for this taskqueue
 288  * complete.  Tasks that begin execution during the execution
 289  * of this function are ignored.
 290  */
 291 static void
 292 gtaskqueue_drain_tq_active(struct gtaskqueue *queue)
 293 {
 294         struct gtaskqueue_busy *tb;
 295         u_int seq;
 296
 297         if (LIST_EMPTY(&queue->tq_active))
 298                 return;
 299
 300         /* Block taskq_terminate().*/
 301         queue->tq_callouts++;
 302
 303         /* Wait for any active task with sequence from the past. */
 304         seq = queue->tq_seq;
 305 restart:
 306         LIST_FOREACH(tb, &queue->tq_active, tb_link) {
 307                 if ((int)(tb->tb_seq - seq) <= 0) {
 308                         TQ_SLEEP(queue, tb->tb_running, "gtq_adrain");
 309                         goto restart;
 310                 }
 311         }
 312
 313         /* Release taskqueue_terminate(). */
 314         queue->tq_callouts--;
 315         if ((queue->tq_flags & TQ_FLAGS_ACTIVE) == 0)
 316                 wakeup_one(queue->tq_threads);
 317 }
 318
 319 void
 320 gtaskqueue_block(struct gtaskqueue *queue)
 321 {
 322
 323         TQ_LOCK(queue);
 324         queue->tq_flags |= TQ_FLAGS_BLOCKED;
 325         TQ_UNLOCK(queue);
 326 }
 327
 328 void
 329 gtaskqueue_unblock(struct gtaskqueue *queue)
 330 {
 331
 332         TQ_LOCK(queue);
 333         queue->tq_flags &= ~TQ_FLAGS_BLOCKED;
 334         if (!STAILQ_EMPTY(&queue->tq_queue))
 335                 queue->tq_enqueue(queue->tq_context);
 336         TQ_UNLOCK(queue);
 337 }
 338
 339 static void
 340 gtaskqueue_run_locked(struct gtaskqueue *queue)
 341 {
 342         struct epoch_tracker et;
 343         struct gtaskqueue_busy tb;
 344         struct gtask *gtask;
 345         bool in_net_epoch;
 346
 347         KASSERT(queue != NULL, ("tq is NULL"));
 348         TQ_ASSERT_LOCKED(queue);
 349         tb.tb_running = NULL;
 350         LIST_INSERT_HEAD(&queue->tq_active, &tb, tb_link);
 351         in_net_epoch = false;
 352
 353         while ((gtask = STAILQ_FIRST(&queue->tq_queue)) != NULL) {
 354                 STAILQ_REMOVE_HEAD(&queue->tq_queue, ta_link);
 355                 gtask->ta_flags &= ~TASK_ENQUEUED;
 356                 tb.tb_running = gtask;
 357                 tb.tb_seq = ++queue->tq_seq;
 358                 TQ_UNLOCK(queue);
 359
 360                 KASSERT(gtask->ta_func != NULL, ("task->ta_func is NULL"));
 361                 if (!in_net_epoch && TASK_IS_NET(gtask)) {
 362                         in_net_epoch = true;
 363                         NET_EPOCH_ENTER(et);
 364                 } else if (in_net_epoch && !TASK_IS_NET(gtask)) {
 365                         NET_EPOCH_EXIT(et);
 366                         in_net_epoch = false;
 367                 }
 368                 gtask->ta_func(gtask->ta_context);
 369
 370                 TQ_LOCK(queue);
 371                 wakeup(gtask);
 372         }
 373         if (in_net_epoch)
 374                 NET_EPOCH_EXIT(et);
 375         LIST_REMOVE(&tb, tb_link);
 376 }
 377
 378 static int
 379 task_is_running(struct gtaskqueue *queue, struct gtask *gtask)
 380 {
 381         struct gtaskqueue_busy *tb;
 382
 383         TQ_ASSERT_LOCKED(queue);
 384         LIST_FOREACH(tb, &queue->tq_active, tb_link) {
 385                 if (tb->tb_running == gtask)
 386                         return (1);
 387         }
 388         return (0);
 389 }
 390
 391 static int
 392 gtaskqueue_cancel_locked(struct gtaskqueue *queue, struct gtask *gtask)
 393 {
 394
 395         if (gtask->ta_flags & TASK_ENQUEUED)
 396                 STAILQ_REMOVE(&queue->tq_queue, gtask, gtask, ta_link);
 397         gtask->ta_flags &= ~TASK_ENQUEUED;
 398         return (task_is_running(queue, gtask) ? EBUSY : 0);
 399 }
 400
 401 int
 402 gtaskqueue_cancel(struct gtaskqueue *queue, struct gtask *gtask)
 403 {
 404         int error;
 405
 406         TQ_LOCK(queue);
 407         error = gtaskqueue_cancel_locked(queue, gtask);
 408         TQ_UNLOCK(queue);
 409
 410         return (error);
 411 }
 412
 413 static void
 414 gtaskqueue_drain_locked(struct gtaskqueue *queue, struct gtask *gtask)
 415 {
 416         while ((gtask->ta_flags & TASK_ENQUEUED) || task_is_running(queue, gtask))
 417                 TQ_SLEEP(queue, gtask, "gtq_drain");
 418 }
 419
 420 void
 421 gtaskqueue_drain(struct gtaskqueue *queue, struct gtask *gtask)
 422 {
 423
 424         if (!queue->tq_spin)
 425                 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL, __func__);
 426
 427         TQ_LOCK(queue);
 428         gtaskqueue_drain_locked(queue, gtask);
 429         TQ_UNLOCK(queue);
 430 }
 431
 432 void
 433 gtaskqueue_drain_all(struct gtaskqueue *queue)
 434 {
 435
 436         if (!queue->tq_spin)
 437                 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL, __func__);
 438
 439         TQ_LOCK(queue);
 440         gtaskqueue_drain_tq_queue(queue);
 441         gtaskqueue_drain_tq_active(queue);
 442         TQ_UNLOCK(queue);
 443 }
 444
 445 static int
 446 _gtaskqueue_start_threads(struct gtaskqueue **tqp, int count, int pri,
 447     cpuset_t *mask, const char *name, va_list ap)
 448 {
 449         char ktname[MAXCOMLEN + 1];
 450         struct thread *td;
 451         struct gtaskqueue *tq;
 452         int i, error;
 453
 454         if (count <= 0)
 455                 return (EINVAL);
 456
 457         vsnprintf(ktname, sizeof(ktname), name, ap);
 458         tq = *tqp;
 459
 460         tq->tq_threads = malloc(sizeof(struct thread *) * count, M_GTASKQUEUE,
 461             M_NOWAIT | M_ZERO);
 462         if (tq->tq_threads == NULL) {
 463                 printf("%s: no memory for %s threads\n", __func__, ktname);
 464                 return (ENOMEM);
 465         }
 466
 467         for (i = 0; i < count; i++) {
 468                 if (count == 1)
 469                         error = kthread_add(gtaskqueue_thread_loop, tqp, NULL,
 470                             &tq->tq_threads[i], RFSTOPPED, 0, "%s", ktname);
 471                 else
 472                         error = kthread_add(gtaskqueue_thread_loop, tqp, NULL,
 473                             &tq->tq_threads[i], RFSTOPPED, 0,
 474                             "%s_%d", ktname, i);
 475                 if (error) {
 476                         /* should be ok to continue, taskqueue_free will dtrt */
 477                         printf("%s: kthread_add(%s): error %d", __func__,
 478                             ktname, error);
 479                         tq->tq_threads[i] = NULL;               /* paranoid */
 480                 } else
 481                         tq->tq_tcount++;
 482         }
 483         for (i = 0; i < count; i++) {
 484                 if (tq->tq_threads[i] == NULL)
 485                         continue;
 486                 td = tq->tq_threads[i];
 487                 if (mask) {
 488                         error = cpuset_setthread(td->td_tid, mask);
 489                         /*
 490                          * Failing to pin is rarely an actual fatal error;
 491                          * it'll just affect performance.
 492                          */
 493                         if (error)
 494                                 printf("%s: curthread=%llu: can't pin; "
 495                                     "error=%d\n",
 496                                     __func__,
 497                                     (unsigned long long) td->td_tid,
 498                                     error);
 499                 }
 500                 thread_lock(td);
 501                 sched_prio(td, pri);
 502                 sched_add(td, SRQ_BORING);
 503         }
 504
 505         return (0);
 506 }
 507
 508 static int
 509 gtaskqueue_start_threads(struct gtaskqueue **tqp, int count, int pri,
 510     const char *name, ...)
 511 {
 512         va_list ap;
 513         int error;
 514
 515         va_start(ap, name);
 516         error = _gtaskqueue_start_threads(tqp, count, pri, NULL, name, ap);
 517         va_end(ap);
 518         return (error);
 519 }
 520
 521 static inline void
 522 gtaskqueue_run_callback(struct gtaskqueue *tq,
 523     enum taskqueue_callback_type cb_type)
 524 {
 525         taskqueue_callback_fn tq_callback;
 526
 527         TQ_ASSERT_UNLOCKED(tq);
 528         tq_callback = tq->tq_callbacks[cb_type];
 529         if (tq_callback != NULL)
 530                 tq_callback(tq->tq_cb_contexts[cb_type]);
 531 }
 532
 533 static void
 534 gtaskqueue_thread_loop(void *arg)
 535 {
 536         struct gtaskqueue **tqp, *tq;
 537
 538         tqp = arg;
 539         tq = *tqp;
 540         gtaskqueue_run_callback(tq, TASKQUEUE_CALLBACK_TYPE_INIT);
 541         TQ_LOCK(tq);
 542         while ((tq->tq_flags & TQ_FLAGS_ACTIVE) != 0) {
 543                 /* XXX ? */
 544                 gtaskqueue_run_locked(tq);
 545                 /*
 546                  * Because taskqueue_run() can drop tq_mutex, we need to
 547                  * check if the TQ_FLAGS_ACTIVE flag wasn't removed in the
 548                  * meantime, which means we missed a wakeup.
 549                  */
 550                 if ((tq->tq_flags & TQ_FLAGS_ACTIVE) == 0)
 551                         break;
 552                 TQ_SLEEP(tq, tq, "-");
 553         }
 554         gtaskqueue_run_locked(tq);
 555         /*
 556          * This thread is on its way out, so just drop the lock temporarily
 557          * in order to call the shutdown callback.  This allows the callback
 558          * to look at the taskqueue, even just before it dies.
 559          */
 560         TQ_UNLOCK(tq);
 561         gtaskqueue_run_callback(tq, TASKQUEUE_CALLBACK_TYPE_SHUTDOWN);
 562         TQ_LOCK(tq);
 563
 564         /* rendezvous with thread that asked us to terminate */
 565         tq->tq_tcount--;
 566         wakeup_one(tq->tq_threads);
 567         TQ_UNLOCK(tq);
 568         kthread_exit();
 569 }
 570
 571 static void
 572 gtaskqueue_thread_enqueue(void *context)
 573 {
 574         struct gtaskqueue **tqp, *tq;
 575
 576         tqp = context;
 577         tq = *tqp;
 578         wakeup_any(tq);
 579 }
 580
 581 static struct gtaskqueue *
 582 gtaskqueue_create_fast(const char *name, int mflags,
 583                  taskqueue_enqueue_fn enqueue, void *context)
 584 {
 585         return _gtaskqueue_create(name, mflags, enqueue, context,
 586                         MTX_SPIN, "fast_taskqueue");
 587 }
 588
 589 struct taskqgroup_cpu {
 590         LIST_HEAD(, grouptask) tgc_tasks;
 591         struct gtaskqueue *tgc_taskq;
 592         int             tgc_cnt;
 593         int             tgc_cpu;
 594 };
 595
 596 struct taskqgroup {
 597         struct taskqgroup_cpu tqg_queue[MAXCPU];
 598         struct mtx      tqg_lock;
 599         const char *    tqg_name;
 600         int             tqg_cnt;
 601 };
 602
 603 struct taskq_bind_task {
 604         struct gtask bt_task;
 605         int     bt_cpuid;
 606 };
 607
 608 static void
 609 taskqgroup_cpu_create(struct taskqgroup *qgroup, int idx, int cpu)
 610 {
 611         struct taskqgroup_cpu *qcpu;
 612
 613         qcpu = &qgroup->tqg_queue[idx];
 614         LIST_INIT(&qcpu->tgc_tasks);
 615         qcpu->tgc_taskq = gtaskqueue_create_fast(NULL, M_WAITOK,
 616             gtaskqueue_thread_enqueue, &qcpu->tgc_taskq);
 617         gtaskqueue_start_threads(&qcpu->tgc_taskq, 1, PI_SOFT,
 618             "%s_%d", qgroup->tqg_name, idx);
 619         qcpu->tgc_cpu = cpu;
 620 }
 621
 622 /*
 623  * Find the taskq with least # of tasks that doesn't currently have any
 624  * other queues from the uniq identifier.
 625  */
 626 static int
 627 taskqgroup_find(struct taskqgroup *qgroup, void *uniq)
 628 {
 629         struct grouptask *n;
 630         int i, idx, mincnt;
 631         int strict;
 632
 633         mtx_assert(&qgroup->tqg_lock, MA_OWNED);
 634         KASSERT(qgroup->tqg_cnt != 0,
 635             ("qgroup %s has no queues", qgroup->tqg_name));
 636
 637         /*
 638          * Two passes: first scan for a queue with the least tasks that
 639          * does not already service this uniq id.  If that fails simply find
 640          * the queue with the least total tasks.
 641          */
 642         for (idx = -1, mincnt = INT_MAX, strict = 1; mincnt == INT_MAX;
 643             strict = 0) {
 644                 for (i = 0; i < qgroup->tqg_cnt; i++) {
 645                         if (qgroup->tqg_queue[i].tgc_cnt > mincnt)
 646                                 continue;
 647                         if (strict) {
 648                                 LIST_FOREACH(n, &qgroup->tqg_queue[i].tgc_tasks,
 649                                     gt_list)
 650                                         if (n->gt_uniq == uniq)
 651                                                 break;
 652                                 if (n != NULL)
 653                                         continue;
 654                         }
 655                         mincnt = qgroup->tqg_queue[i].tgc_cnt;
 656                         idx = i;
 657                 }
 658         }
 659         if (idx == -1)
 660                 panic("%s: failed to pick a qid.", __func__);
 661
 662         return (idx);
 663 }
 664
 665 void
 666 taskqgroup_attach(struct taskqgroup *qgroup, struct grouptask *gtask,
 667     void *uniq, device_t dev, struct resource *irq, const char *name)
 668 {
 669         int cpu, qid, error;
 670
 671         KASSERT(qgroup->tqg_cnt > 0,
 672             ("qgroup %s has no queues", qgroup->tqg_name));
 673
 674         gtask->gt_uniq = uniq;
 675         snprintf(gtask->gt_name, GROUPTASK_NAMELEN, "%s", name ? name : "grouptask");
 676         gtask->gt_dev = dev;
 677         gtask->gt_irq = irq;
 678         gtask->gt_cpu = -1;
 679         mtx_lock(&qgroup->tqg_lock);
 680         qid = taskqgroup_find(qgroup, uniq);
 681         qgroup->tqg_queue[qid].tgc_cnt++;
 682         LIST_INSERT_HEAD(&qgroup->tqg_queue[qid].tgc_tasks, gtask, gt_list);
 683         gtask->gt_taskqueue = qgroup->tqg_queue[qid].tgc_taskq;
 684         if (dev != NULL && irq != NULL) {
 685                 cpu = qgroup->tqg_queue[qid].tgc_cpu;
 686                 gtask->gt_cpu = cpu;
 687                 mtx_unlock(&qgroup->tqg_lock);
 688                 error = bus_bind_intr(dev, irq, cpu);
 689                 if (error)
 690                         printf("%s: binding interrupt failed for %s: %d\n",
 691                             __func__, gtask->gt_name, error);
 692         } else
 693                 mtx_unlock(&qgroup->tqg_lock);
 694 }
 695
 696 int
 697 taskqgroup_attach_cpu(struct taskqgroup *qgroup, struct grouptask *gtask,
 698     void *uniq, int cpu, device_t dev, struct resource *irq, const char *name)
 699 {
 700         int i, qid, error;
 701
 702         gtask->gt_uniq = uniq;
 703         snprintf(gtask->gt_name, GROUPTASK_NAMELEN, "%s", name ? name : "grouptask");
 704         gtask->gt_dev = dev;
 705         gtask->gt_irq = irq;
 706         gtask->gt_cpu = cpu;
 707         mtx_lock(&qgroup->tqg_lock);
 708         for (i = 0, qid = -1; i < qgroup->tqg_cnt; i++)
 709                 if (qgroup->tqg_queue[i].tgc_cpu == cpu) {
 710                         qid = i;
 711                         break;
 712                 }
 713         if (qid == -1) {
 714                 mtx_unlock(&qgroup->tqg_lock);
 715                 printf("%s: qid not found for %s cpu=%d\n", __func__, gtask->gt_name, cpu);
 716                 return (EINVAL);
 717         }
 718         qgroup->tqg_queue[qid].tgc_cnt++;
 719         LIST_INSERT_HEAD(&qgroup->tqg_queue[qid].tgc_tasks, gtask, gt_list);
 720         gtask->gt_taskqueue = qgroup->tqg_queue[qid].tgc_taskq;
 721         cpu = qgroup->tqg_queue[qid].tgc_cpu;
 722         mtx_unlock(&qgroup->tqg_lock);
 723
 724         if (dev != NULL && irq != NULL) {
 725                 error = bus_bind_intr(dev, irq, cpu);
 726                 if (error)
 727                         printf("%s: binding interrupt failed for %s: %d\n",
 728                             __func__, gtask->gt_name, error);
 729         }
 730         return (0);
 731 }
 732
 733 void
 734 taskqgroup_detach(struct taskqgroup *qgroup, struct grouptask *gtask)
 735 {
 736         int i;
 737
 738         grouptask_block(gtask);
 739         mtx_lock(&qgroup->tqg_lock);
 740         for (i = 0; i < qgroup->tqg_cnt; i++)
 741                 if (qgroup->tqg_queue[i].tgc_taskq == gtask->gt_taskqueue)
 742                         break;
 743         if (i == qgroup->tqg_cnt)
 744                 panic("%s: task %s not in group", __func__, gtask->gt_name);
 745         qgroup->tqg_queue[i].tgc_cnt--;
 746         LIST_REMOVE(gtask, gt_list);
 747         mtx_unlock(&qgroup->tqg_lock);
 748         gtask->gt_taskqueue = NULL;
 749         gtask->gt_task.ta_flags &= ~TASK_NOENQUEUE;
 750 }
 751
 752 static void
 753 taskqgroup_binder(void *ctx)
 754 {
 755         struct taskq_bind_task *gtask;
 756         cpuset_t mask;
 757         int error;
 758
 759         gtask = ctx;
 760         CPU_ZERO(&mask);
 761         CPU_SET(gtask->bt_cpuid, &mask);
 762         error = cpuset_setthread(curthread->td_tid, &mask);
 763         thread_lock(curthread);
 764         sched_bind(curthread, gtask->bt_cpuid);
 765         thread_unlock(curthread);
 766
 767         if (error)
 768                 printf("%s: binding curthread failed: %d\n", __func__, error);
 769         free(gtask, M_DEVBUF);
 770 }
 771
 772 void
 773 taskqgroup_bind(struct taskqgroup *qgroup)
 774 {
 775         struct taskq_bind_task *gtask;
 776         int i;
 777
 778         /*
 779          * Bind taskqueue threads to specific CPUs, if they have been assigned
 780          * one.
 781          */
 782         if (qgroup->tqg_cnt == 1)
 783                 return;
 784
 785         for (i = 0; i < qgroup->tqg_cnt; i++) {
 786                 gtask = malloc(sizeof(*gtask), M_DEVBUF, M_WAITOK);
 787                 GTASK_INIT(&gtask->bt_task, 0, 0, taskqgroup_binder, gtask);
 788                 gtask->bt_cpuid = qgroup->tqg_queue[i].tgc_cpu;
 789                 grouptaskqueue_enqueue(qgroup->tqg_queue[i].tgc_taskq,
 790                     &gtask->bt_task);
 791         }
 792 }
 793
 794 struct taskqgroup *
 795 taskqgroup_create(const char *name, int cnt, int stride)
 796 {
 797         struct taskqgroup *qgroup;
 798         int cpu, i, j;
 799
 800         qgroup = malloc(sizeof(*qgroup), M_GTASKQUEUE, M_WAITOK | M_ZERO);
 801         mtx_init(&qgroup->tqg_lock, "taskqgroup", NULL, MTX_DEF);
 802         qgroup->tqg_name = name;
 803         qgroup->tqg_cnt = cnt;
 804
 805         for (cpu = i = 0; i < cnt; i++) {
 806                 taskqgroup_cpu_create(qgroup, i, cpu);
 807                 for (j = 0; j < stride; j++)
 808                         cpu = CPU_NEXT(cpu);
 809         }
 810         return (qgroup);
 811 }
 812
 813 void
 814 taskqgroup_destroy(struct taskqgroup *qgroup)
 815 {
 816 }
 817
 818 void
 819 taskqgroup_drain_all(struct taskqgroup *tqg)
 820 {
 821         struct gtaskqueue *q;
 822
 823         for (int i = 0; i < mp_ncpus; i++) {
 824                 q = tqg->tqg_queue[i].tgc_taskq;
 825                 if (q == NULL)
 826                         continue;
 827                 gtaskqueue_drain_all(q);
 828         }
 829 }