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/cdefs.h>
  30 #include <sys/param.h>
  31 #include <sys/systm.h>
  32 #include <sys/bus.h>
  33 #include <sys/cpumask.h>
  34 #include <sys/kernel.h>
  35 #include <sys/libkern.h>
  36 #include <sys/limits.h>
  37 #include <sys/lock.h>
  38 #include <sys/malloc.h>
  39 #include <sys/proc.h>
  40 #include <sys/sched.h>
  41 #include <sys/gtaskqueue.h>
  42 #include <sys/unistd.h>
  43 #include <machine/stdarg.h>
  44
  45 static MALLOC_DEFINE(M_GTASKQUEUE, "gtaskqueue", "Group Task Queues");
  46 static void     gtaskqueue_thread_enqueue(void *);
  47 static void     gtaskqueue_thread_loop(void *arg);
  48 static int      task_is_running(struct gtaskqueue *queue, struct gtask *gtask);
  49 static void     gtaskqueue_drain_locked(struct gtaskqueue *queue, struct gtask *gtask);
  50
  51 TASKQGROUP_DEFINE(softirq, ncpus, 1);
  52
  53 struct gtaskqueue_busy {
  54         struct gtask            *tb_running;
  55         u_int                    tb_seq;
  56         LIST_ENTRY(gtaskqueue_busy) tb_link;
  57 };
  58
  59 typedef void (*gtaskqueue_enqueue_fn)(void *context);
  60
  61 struct gtaskqueue {
  62         STAILQ_HEAD(, gtask)    tq_queue;
  63         LIST_HEAD(, gtaskqueue_busy) tq_active;
  64         u_int                   tq_seq;
  65         int                     tq_callouts;
  66         struct lock             tq_lock;
  67         gtaskqueue_enqueue_fn   tq_enqueue;
  68         void                    *tq_context;
  69         const char              *tq_name;
  70         struct thread           **tq_threads;
  71         int                     tq_tcount;
  72         int                     tq_flags;
  73 #if 0
  74         taskqueue_callback_fn   tq_callbacks[TASKQUEUE_NUM_CALLBACKS];
  75         void                    *tq_cb_contexts[TASKQUEUE_NUM_CALLBACKS];
  76 #endif
  77 };
  78
  79 #define TQ_FLAGS_ACTIVE         (1 << 0)
  80 #define TQ_FLAGS_BLOCKED        (1 << 1)
  81 #define TQ_FLAGS_UNLOCKED_ENQUEUE       (1 << 2)
  82
  83 #define DT_CALLOUT_ARMED        (1 << 0)
  84
  85 #define TQ_LOCK(tq)             lockmgr(&(tq)->tq_lock, LK_EXCLUSIVE)
  86 #define TQ_ASSERT_LOCKED(tq)    KKASSERT(lockstatus(&(tq)->tq_lock, NULL) != 0)
  87 #define TQ_UNLOCK(tq)           lockmgr(&(tq)->tq_lock, LK_RELEASE);
  88 #define TQ_ASSERT_UNLOCKED(tq)  KKASSERT(lockstatus(&(tq)->tq_lock) == 0)
  89
  90 #ifdef INVARIANTS
  91 static void
  92 gtask_dump(struct gtask *gtask)
  93 {
  94         kprintf("gtask: %p ta_flags=%x ta_priority=%d ta_func=%p "
  95                 "ta_context=%p\n",
  96                 gtask, gtask->ta_flags, gtask->ta_priority,
  97                 gtask->ta_func, gtask->ta_context);
  98 }
  99 #endif
 100
 101 static __inline int
 102 TQ_SLEEP(struct gtaskqueue *tq, void *p, const char *wm)
 103 {
 104         return (lksleep(p, &tq->tq_lock, 0, wm, 0));
 105 }
 106
 107 static struct gtaskqueue *
 108 _gtaskqueue_create(const char *name, int mflags,
 109                  taskqueue_enqueue_fn enqueue, void *context,
 110                  int lkflags, const char *mtxname __unused)
 111 {
 112         struct gtaskqueue *queue;
 113
 114         queue = kmalloc(sizeof(struct gtaskqueue),
 115                         M_GTASKQUEUE, mflags | M_ZERO);
 116         if (!queue) {
 117                 kprintf("_gtaskqueue_create: kmalloc failed %08x\n", mflags);
 118                 return (NULL);
 119         }
 120
 121         STAILQ_INIT(&queue->tq_queue);
 122         LIST_INIT(&queue->tq_active);
 123         queue->tq_enqueue = enqueue;
 124         queue->tq_context = context;
 125         queue->tq_name = name ? name : "taskqueue";
 126         queue->tq_flags |= TQ_FLAGS_ACTIVE;
 127         if (enqueue == gtaskqueue_thread_enqueue)
 128                 queue->tq_flags |= TQ_FLAGS_UNLOCKED_ENQUEUE;
 129         lockinit(&queue->tq_lock, queue->tq_name, 0, 0);
 130
 131         return (queue);
 132 }
 133
 134 /*
 135  * Signal a taskqueue thread to terminate.
 136  */
 137 static void
 138 gtaskqueue_terminate(struct thread **pp, struct gtaskqueue *tq)
 139 {
 140
 141         while (tq->tq_tcount > 0 || tq->tq_callouts > 0) {
 142                 wakeup(tq);
 143                 TQ_SLEEP(tq, pp, "gtq_destroy");
 144         }
 145 }
 146
 147 static void __unused
 148 gtaskqueue_free(struct gtaskqueue *queue)
 149 {
 150
 151         TQ_LOCK(queue);
 152         queue->tq_flags &= ~TQ_FLAGS_ACTIVE;
 153         gtaskqueue_terminate(queue->tq_threads, queue);
 154         KASSERT(LIST_EMPTY(&queue->tq_active), ("Tasks still running?"));
 155         KASSERT(queue->tq_callouts == 0, ("Armed timeout tasks"));
 156         lockuninit(&queue->tq_lock);
 157         kfree(queue->tq_threads, M_GTASKQUEUE);
 158         /*kfree(queue->tq_name, M_GTASKQUEUE);*/
 159         kfree(queue, M_GTASKQUEUE);
 160 }
 161
 162 /*
 163  * Wait for all to complete, then prevent it from being enqueued
 164  */
 165 void
 166 grouptask_block(struct grouptask *grouptask)
 167 {
 168         struct gtaskqueue *queue = grouptask->gt_taskqueue;
 169         struct gtask *gtask = &grouptask->gt_task;
 170
 171 #ifdef INVARIANTS
 172         if (queue == NULL) {
 173                 gtask_dump(gtask);
 174                 panic("queue == NULL");
 175         }
 176 #endif
 177         TQ_LOCK(queue);
 178         gtask->ta_flags |= TASK_NOENQUEUE;
 179         gtaskqueue_drain_locked(queue, gtask);
 180         TQ_UNLOCK(queue);
 181 }
 182
 183 void
 184 grouptask_unblock(struct grouptask *grouptask)
 185 {
 186         struct gtaskqueue *queue = grouptask->gt_taskqueue;
 187         struct gtask *gtask = &grouptask->gt_task;
 188
 189 #ifdef INVARIANTS
 190         if (queue == NULL) {
 191                 gtask_dump(gtask);
 192                 panic("queue == NULL");
 193         }
 194 #endif
 195         TQ_LOCK(queue);
 196         gtask->ta_flags &= ~TASK_NOENQUEUE;
 197         TQ_UNLOCK(queue);
 198 }
 199
 200 int
 201 grouptaskqueue_enqueue(struct gtaskqueue *queue, struct gtask *gtask)
 202 {
 203 #ifdef INVARIANTS
 204         if (queue == NULL) {
 205                 gtask_dump(gtask);
 206                 panic("queue == NULL");
 207         }
 208 #endif
 209         TQ_LOCK(queue);
 210         if (gtask->ta_flags & TASK_ENQUEUED) {
 211                 TQ_UNLOCK(queue);
 212                 return (0);
 213         }
 214         if (gtask->ta_flags & TASK_NOENQUEUE) {
 215                 TQ_UNLOCK(queue);
 216                 return (EAGAIN);
 217         }
 218         STAILQ_INSERT_TAIL(&queue->tq_queue, gtask, ta_link);
 219         gtask->ta_flags |= TASK_ENQUEUED;
 220         TQ_UNLOCK(queue);
 221         if ((queue->tq_flags & TQ_FLAGS_BLOCKED) == 0)
 222                 queue->tq_enqueue(queue->tq_context);
 223         return (0);
 224 }
 225
 226 static void
 227 gtaskqueue_task_nop_fn(void *context)
 228 {
 229 }
 230
 231 /*
 232  * Block until all currently queued tasks in this taskqueue
 233  * have begun execution.  Tasks queued during execution of
 234  * this function are ignored.
 235  */
 236 static void
 237 gtaskqueue_drain_tq_queue(struct gtaskqueue *queue)
 238 {
 239         struct gtask t_barrier;
 240
 241         if (STAILQ_EMPTY(&queue->tq_queue))
 242                 return;
 243
 244         /*
 245          * Enqueue our barrier after all current tasks, but with
 246          * the highest priority so that newly queued tasks cannot
 247          * pass it.  Because of the high priority, we can not use
 248          * taskqueue_enqueue_locked directly (which drops the lock
 249          * anyway) so just insert it at tail while we have the
 250          * queue lock.
 251          */
 252         GTASK_INIT(&t_barrier, 0, USHRT_MAX, gtaskqueue_task_nop_fn, &t_barrier);
 253         STAILQ_INSERT_TAIL(&queue->tq_queue, &t_barrier, ta_link);
 254         t_barrier.ta_flags |= TASK_ENQUEUED;
 255
 256         /*
 257          * Once the barrier has executed, all previously queued tasks
 258          * have completed or are currently executing.
 259          */
 260         while (t_barrier.ta_flags & TASK_ENQUEUED)
 261                 TQ_SLEEP(queue, &t_barrier, "gtq_qdrain");
 262 }
 263
 264 /*
 265  * Block until all currently executing tasks for this taskqueue
 266  * complete.  Tasks that begin execution during the execution
 267  * of this function are ignored.
 268  */
 269 static void
 270 gtaskqueue_drain_tq_active(struct gtaskqueue *queue)
 271 {
 272         struct gtaskqueue_busy *tb;
 273         u_int seq;
 274
 275         if (LIST_EMPTY(&queue->tq_active))
 276                 return;
 277
 278         /* Block taskq_terminate().*/
 279         queue->tq_callouts++;
 280
 281         /* Wait for any active task with sequence from the past. */
 282         seq = queue->tq_seq;
 283 restart:
 284         LIST_FOREACH(tb, &queue->tq_active, tb_link) {
 285                 if ((int)(tb->tb_seq - seq) <= 0) {
 286                         TQ_SLEEP(queue, tb->tb_running, "gtq_adrain");
 287                         goto restart;
 288                 }
 289         }
 290
 291         /* Release taskqueue_terminate(). */
 292         queue->tq_callouts--;
 293         if ((queue->tq_flags & TQ_FLAGS_ACTIVE) == 0)
 294                 wakeup_one(queue->tq_threads);
 295 }
 296
 297 void
 298 gtaskqueue_block(struct gtaskqueue *queue)
 299 {
 300
 301         TQ_LOCK(queue);
 302         queue->tq_flags |= TQ_FLAGS_BLOCKED;
 303         TQ_UNLOCK(queue);
 304 }
 305
 306 void
 307 gtaskqueue_unblock(struct gtaskqueue *queue)
 308 {
 309
 310         TQ_LOCK(queue);
 311         queue->tq_flags &= ~TQ_FLAGS_BLOCKED;
 312         if (!STAILQ_EMPTY(&queue->tq_queue))
 313                 queue->tq_enqueue(queue->tq_context);
 314         TQ_UNLOCK(queue);
 315 }
 316
 317 static void
 318 gtaskqueue_run_locked(struct gtaskqueue *queue)
 319 {
 320         struct gtaskqueue_busy tb;
 321         struct gtask *gtask;
 322 #if 0
 323         struct epoch_tracker et;
 324         bool in_net_epoch;
 325 #endif
 326
 327         KASSERT(queue != NULL, ("tq is NULL"));
 328         TQ_ASSERT_LOCKED(queue);
 329         tb.tb_running = NULL;
 330         LIST_INSERT_HEAD(&queue->tq_active, &tb, tb_link);
 331 #if 0
 332         in_net_epoch = false;
 333 #endif
 334
 335         while ((gtask = STAILQ_FIRST(&queue->tq_queue)) != NULL) {
 336                 STAILQ_REMOVE_HEAD(&queue->tq_queue, ta_link);
 337                 gtask->ta_flags &= ~TASK_ENQUEUED;
 338                 tb.tb_running = gtask;
 339                 tb.tb_seq = ++queue->tq_seq;
 340                 TQ_UNLOCK(queue);
 341
 342                 KASSERT(gtask->ta_func != NULL, ("task->ta_func is NULL"));
 343 #if 0
 344                 if (!in_net_epoch && TASK_IS_NET(gtask)) {
 345                         in_net_epoch = true;
 346                         NET_EPOCH_ENTER(et);
 347                 } else if (in_net_epoch && !TASK_IS_NET(gtask)) {
 348                         NET_EPOCH_EXIT(et);
 349                         in_net_epoch = false;
 350                 }
 351 #endif
 352                 gtask->ta_func(gtask->ta_context);
 353
 354                 TQ_LOCK(queue);
 355                 wakeup(gtask);
 356         }
 357 #if 0
 358         if (in_net_epoch)
 359                 NET_EPOCH_EXIT(et);
 360 #endif
 361         LIST_REMOVE(&tb, tb_link);
 362 }
 363
 364 static int
 365 task_is_running(struct gtaskqueue *queue, struct gtask *gtask)
 366 {
 367         struct gtaskqueue_busy *tb;
 368
 369         TQ_ASSERT_LOCKED(queue);
 370         LIST_FOREACH(tb, &queue->tq_active, tb_link) {
 371                 if (tb->tb_running == gtask)
 372                         return (1);
 373         }
 374         return (0);
 375 }
 376
 377 static int
 378 gtaskqueue_cancel_locked(struct gtaskqueue *queue, struct gtask *gtask)
 379 {
 380
 381         if (gtask->ta_flags & TASK_ENQUEUED)
 382                 STAILQ_REMOVE(&queue->tq_queue, gtask, gtask, ta_link);
 383         gtask->ta_flags &= ~TASK_ENQUEUED;
 384         return (task_is_running(queue, gtask) ? EBUSY : 0);
 385 }
 386
 387 int
 388 gtaskqueue_cancel(struct gtaskqueue *queue, struct gtask *gtask)
 389 {
 390         int error;
 391
 392         TQ_LOCK(queue);
 393         error = gtaskqueue_cancel_locked(queue, gtask);
 394         TQ_UNLOCK(queue);
 395
 396         return (error);
 397 }
 398
 399 static void
 400 gtaskqueue_drain_locked(struct gtaskqueue *queue, struct gtask *gtask)
 401 {
 402         while ((gtask->ta_flags & TASK_ENQUEUED) || task_is_running(queue, gtask))
 403                 TQ_SLEEP(queue, gtask, "gtq_drain");
 404 }
 405
 406 void
 407 gtaskqueue_drain(struct gtaskqueue *queue, struct gtask *gtask)
 408 {
 409         TQ_LOCK(queue);
 410         gtaskqueue_drain_locked(queue, gtask);
 411         TQ_UNLOCK(queue);
 412 }
 413
 414 void
 415 gtaskqueue_drain_all(struct gtaskqueue *queue)
 416 {
 417
 418         TQ_LOCK(queue);
 419         gtaskqueue_drain_tq_queue(queue);
 420         gtaskqueue_drain_tq_active(queue);
 421         TQ_UNLOCK(queue);
 422 }
 423
 424 static int __printflike(4, 0)
 425 _gtaskqueue_start_threads(struct gtaskqueue **tqp, int count, int pri,
 426                           const char *name, __va_list ap)
 427 {
 428         char ktname[MAXCOMLEN + 1];
 429         struct thread *td;
 430         struct gtaskqueue *tq;
 431         int i, error;
 432
 433         if (count <= 0)
 434                 return (EINVAL);
 435
 436         kvsnprintf(ktname, sizeof(ktname), name, ap);
 437         tq = *tqp;
 438
 439         tq->tq_threads = kmalloc(sizeof(struct thread *) * count,
 440                                  M_GTASKQUEUE, M_WAITOK | M_ZERO);
 441
 442         for (i = 0; i < count; i++) {
 443                 int cpu = i % ncpus;
 444                 if (count == 1) {
 445                         error = lwkt_create(gtaskqueue_thread_loop, tqp,
 446                                             &tq->tq_threads[i], NULL,
 447                                             TDF_NOSTART, cpu,
 448                                             "%s", ktname);
 449                 } else {
 450                         error = lwkt_create(gtaskqueue_thread_loop, tqp,
 451                                             &tq->tq_threads[i], NULL,
 452                                             TDF_NOSTART, cpu,
 453                                             "%s_%d", ktname, i);
 454                 }
 455                 if (error) {
 456                         /* should be ok to continue, taskqueue_free will dtrt */
 457                         kprintf("%s: lwkt_create(%s): error %d",
 458                                 __func__, ktname, error);
 459                         tq->tq_threads[i] = NULL;               /* paranoid */
 460                 } else
 461                         tq->tq_tcount++;
 462         }
 463         for (i = 0; i < count; i++) {
 464                 if (tq->tq_threads[i] == NULL)
 465                         continue;
 466                 td = tq->tq_threads[i];
 467                 lwkt_setpri_initial(td, pri);
 468                 lwkt_schedule(td);
 469         }
 470
 471         return (0);
 472 }
 473
 474 static int __printflike(4, 5)
 475 gtaskqueue_start_threads(struct gtaskqueue **tqp, int count, int pri,
 476                          const char *name, ...)
 477 {
 478         __va_list ap;
 479         int error;
 480
 481         __va_start(ap, name);
 482         error = _gtaskqueue_start_threads(tqp, count, pri, name, ap);
 483         __va_end(ap);
 484         return (error);
 485 }
 486
 487 #if 0
 488 static inline void
 489 gtaskqueue_run_callback(struct gtaskqueue *tq,
 490     enum taskqueue_callback_type cb_type)
 491 {
 492         taskqueue_callback_fn tq_callback;
 493
 494         TQ_ASSERT_UNLOCKED(tq);
 495         tq_callback = tq->tq_callbacks[cb_type];
 496         if (tq_callback != NULL)
 497                 tq_callback(tq->tq_cb_contexts[cb_type]);
 498 }
 499 #endif
 500
 501 static void
 502 gtaskqueue_thread_loop(void *arg)
 503 {
 504         struct gtaskqueue **tqp, *tq;
 505
 506         tqp = arg;
 507         tq = *tqp;
 508 #if 0
 509         gtaskqueue_run_callback(tq, TASKQUEUE_CALLBACK_TYPE_INIT);
 510 #endif
 511         TQ_LOCK(tq);
 512         while ((tq->tq_flags & TQ_FLAGS_ACTIVE) != 0) {
 513                 /* XXX ? */
 514                 gtaskqueue_run_locked(tq);
 515                 /*
 516                  * Because taskqueue_run() can drop tq_mutex, we need to
 517                  * check if the TQ_FLAGS_ACTIVE flag wasn't removed in the
 518                  * meantime, which means we missed a wakeup.
 519                  */
 520                 if ((tq->tq_flags & TQ_FLAGS_ACTIVE) == 0)
 521                         break;
 522                 TQ_SLEEP(tq, tq, "-");
 523         }
 524         gtaskqueue_run_locked(tq);
 525         /*
 526          * This thread is on its way out, so just drop the lock temporarily
 527          * in order to call the shutdown callback.  This allows the callback
 528          * to look at the taskqueue, even just before it dies.
 529          */
 530 #if 0
 531         TQ_UNLOCK(tq);
 532         gtaskqueue_run_callback(tq, TASKQUEUE_CALLBACK_TYPE_SHUTDOWN);
 533         TQ_LOCK(tq);
 534 #endif
 535
 536         /* rendezvous with thread that asked us to terminate */
 537         tq->tq_tcount--;
 538         wakeup_one(tq->tq_threads);
 539         TQ_UNLOCK(tq);
 540         lwkt_exit();
 541 }
 542
 543 static void
 544 gtaskqueue_thread_enqueue(void *context)
 545 {
 546         struct gtaskqueue **tqp, *tq;
 547
 548         tqp = context;
 549         tq = *tqp;
 550         wakeup_one(tq);
 551 }
 552
 553 /*
 554  * NOTE: FreeBSD uses MTX_SPIN locks, which doesn't make a whole lot
 555  *       of sense (over-use of spin-locks in general). In DFly we
 556  *       want to use blockable locks for almost everything.
 557  */
 558 static struct gtaskqueue *
 559 gtaskqueue_create_fast(const char *name, int mflags,
 560                        taskqueue_enqueue_fn enqueue, void *context)
 561 {
 562         return _gtaskqueue_create(name, mflags, enqueue, context,
 563                                   0, "fast_taskqueue");
 564 }
 565
 566 struct taskqgroup_cpu {
 567         LIST_HEAD(, grouptask) tgc_tasks;
 568         struct gtaskqueue *tgc_taskq;
 569         int             tgc_cnt;
 570         int             tgc_cpu;
 571 };
 572
 573 struct taskqgroup {
 574         struct taskqgroup_cpu tqg_queue[MAXCPU];
 575         struct lock     tqg_lock;
 576         const char *    tqg_name;
 577         int             tqg_cnt;
 578 };
 579
 580 struct taskq_bind_task {
 581         struct gtask bt_task;
 582         int     bt_cpuid;
 583 };
 584
 585 static void
 586 taskqgroup_cpu_create(struct taskqgroup *qgroup, int idx, int cpu)
 587 {
 588         struct taskqgroup_cpu *qcpu;
 589
 590         qcpu = &qgroup->tqg_queue[idx];
 591         LIST_INIT(&qcpu->tgc_tasks);
 592         qcpu->tgc_taskq = gtaskqueue_create_fast(NULL, M_WAITOK,
 593                                                  gtaskqueue_thread_enqueue,
 594                                                  &qcpu->tgc_taskq);
 595         gtaskqueue_start_threads(&qcpu->tgc_taskq, 1, TDPRI_KERN_DAEMON,
 596                                  "%s_%d", qgroup->tqg_name, idx);
 597         qcpu->tgc_cpu = cpu;
 598 }
 599
 600 /*
 601  * Find the taskq with least # of tasks that doesn't currently have any
 602  * other queues from the uniq identifier.
 603  */
 604 static int
 605 taskqgroup_find(struct taskqgroup *qgroup, void *uniq)
 606 {
 607         struct grouptask *n;
 608         int i, idx, mincnt;
 609         int strict;
 610
 611         KKASSERT(lockstatus(&qgroup->tqg_lock, NULL) != 0);
 612         KASSERT(qgroup->tqg_cnt != 0,
 613             ("qgroup %s has no queues", qgroup->tqg_name));
 614
 615         /*
 616          * Two passes: first scan for a queue with the least tasks that
 617          * does not already service this uniq id.  If that fails simply find
 618          * the queue with the least total tasks.
 619          */
 620         for (idx = -1, mincnt = INT_MAX, strict = 1; mincnt == INT_MAX;
 621             strict = 0) {
 622                 for (i = 0; i < qgroup->tqg_cnt; i++) {
 623                         if (qgroup->tqg_queue[i].tgc_cnt > mincnt)
 624                                 continue;
 625                         if (strict) {
 626                                 LIST_FOREACH(n, &qgroup->tqg_queue[i].tgc_tasks,
 627                                     gt_list)
 628                                         if (n->gt_uniq == uniq)
 629                                                 break;
 630                                 if (n != NULL)
 631                                         continue;
 632                         }
 633                         mincnt = qgroup->tqg_queue[i].tgc_cnt;
 634                         idx = i;
 635                 }
 636         }
 637         if (idx == -1)
 638                 panic("%s: failed to pick a qid.", __func__);
 639
 640         return (idx);
 641 }
 642
 643 void
 644 taskqgroup_attach(struct taskqgroup *qgroup, struct grouptask *gtask,
 645     void *uniq, device_t dev, struct resource *irq, const char *name)
 646 {
 647         int cpu, qid, error;
 648
 649         KASSERT(qgroup->tqg_cnt > 0,
 650             ("qgroup %s has no queues", qgroup->tqg_name));
 651
 652         gtask->gt_uniq = uniq;
 653         ksnprintf(gtask->gt_name, GROUPTASK_NAMELEN, "%s", name ? name : "grouptask");
 654         gtask->gt_dev = dev;
 655         gtask->gt_irq = irq;
 656         gtask->gt_cpu = -1;
 657         lockmgr(&qgroup->tqg_lock, LK_EXCLUSIVE);
 658         qid = taskqgroup_find(qgroup, uniq);
 659         qgroup->tqg_queue[qid].tgc_cnt++;
 660         LIST_INSERT_HEAD(&qgroup->tqg_queue[qid].tgc_tasks, gtask, gt_list);
 661         gtask->gt_taskqueue = qgroup->tqg_queue[qid].tgc_taskq;
 662         if (dev != NULL && irq != NULL) {
 663                 cpu = qgroup->tqg_queue[qid].tgc_cpu;
 664                 gtask->gt_cpu = cpu;
 665                 lockmgr(&qgroup->tqg_lock, LK_RELEASE);
 666 #if 0
 667                 /*
 668                  * XXX FreeBSD created a mess by separating out the cpu
 669                  * binding from bus_setup_intr().  Punt for now.
 670                  */
 671                 error = bus_bind_intr(dev, irq, cpu);
 672 #endif
 673                 error = 0;
 674
 675                 if (error)
 676                         kprintf("%s: binding interrupt failed for %s: %d\n",
 677                             __func__, gtask->gt_name, error);
 678         } else {
 679                 lockmgr(&qgroup->tqg_lock, LK_RELEASE);
 680         }
 681 }
 682
 683 int
 684 taskqgroup_attach_cpu(struct taskqgroup *qgroup, struct grouptask *gtask,
 685     void *uniq, int cpu, device_t dev, struct resource *irq, const char *name)
 686 {
 687         int i, qid, error;
 688
 689         gtask->gt_uniq = uniq;
 690         ksnprintf(gtask->gt_name, GROUPTASK_NAMELEN, "%s", name ? name : "grouptask");
 691         gtask->gt_dev = dev;
 692         gtask->gt_irq = irq;
 693         gtask->gt_cpu = cpu;
 694         lockmgr(&qgroup->tqg_lock, LK_EXCLUSIVE);
 695         for (i = 0, qid = -1; i < qgroup->tqg_cnt; i++) {
 696                 if (qgroup->tqg_queue[i].tgc_cpu == cpu) {
 697                         qid = i;
 698                         break;
 699                 }
 700         }
 701         if (qid == -1) {
 702                 lockmgr(&qgroup->tqg_lock, LK_RELEASE);
 703                 kprintf("%s: qid not found for %s cpu=%d\n",
 704                         __func__, gtask->gt_name, cpu);
 705                 return (EINVAL);
 706         }
 707         qgroup->tqg_queue[qid].tgc_cnt++;
 708         LIST_INSERT_HEAD(&qgroup->tqg_queue[qid].tgc_tasks, gtask, gt_list);
 709         gtask->gt_taskqueue = qgroup->tqg_queue[qid].tgc_taskq;
 710         cpu = qgroup->tqg_queue[qid].tgc_cpu;
 711         lockmgr(&qgroup->tqg_lock, LK_RELEASE);
 712
 713         if (dev != NULL && irq != NULL) {
 714 #if 0
 715                 /*
 716                  * XXX FreeBSD created a mess by separating out the cpu
 717                  * binding from bus_setup_intr().  Punt for now.
 718                  */
 719                 error = bus_bind_intr(dev, irq, cpu);
 720 #endif
 721                 error = 0;
 722
 723                 if (error) {
 724                         kprintf("%s: binding interrupt failed for %s: %d\n",
 725                             __func__, gtask->gt_name, error);
 726                 }
 727         }
 728         return (0);
 729 }
 730
 731 void
 732 taskqgroup_detach(struct taskqgroup *qgroup, struct grouptask *gtask)
 733 {
 734         int i;
 735
 736         grouptask_block(gtask);
 737         lockmgr(&qgroup->tqg_lock, LK_EXCLUSIVE);
 738         for (i = 0; i < qgroup->tqg_cnt; i++)
 739                 if (qgroup->tqg_queue[i].tgc_taskq == gtask->gt_taskqueue)
 740                         break;
 741         if (i == qgroup->tqg_cnt)
 742                 panic("%s: task %s not in group", __func__, gtask->gt_name);
 743         qgroup->tqg_queue[i].tgc_cnt--;
 744         LIST_REMOVE(gtask, gt_list);
 745         lockmgr(&qgroup->tqg_lock, LK_RELEASE);
 746         gtask->gt_taskqueue = NULL;
 747         gtask->gt_task.ta_flags &= ~TASK_NOENQUEUE;
 748 }
 749
 750 static void
 751 taskqgroup_binder(void *ctx)
 752 {
 753         struct taskq_bind_task *gtask;
 754
 755         gtask = ctx;
 756         lwkt_migratecpu(gtask->bt_cpuid);
 757         kfree(gtask, M_DEVBUF);
 758 }
 759
 760 void
 761 taskqgroup_bind(struct taskqgroup *qgroup)
 762 {
 763         struct taskq_bind_task *gtask;
 764         int i;
 765
 766         /*
 767          * Bind taskqueue threads to specific CPUs, if they have been assigned
 768          * one.
 769          */
 770         if (qgroup->tqg_cnt == 1)
 771                 return;
 772
 773         for (i = 0; i < qgroup->tqg_cnt; i++) {
 774                 gtask = kmalloc(sizeof(*gtask), M_DEVBUF, M_WAITOK);
 775                 GTASK_INIT(&gtask->bt_task, 0, 0, taskqgroup_binder, gtask);
 776                 gtask->bt_cpuid = qgroup->tqg_queue[i].tgc_cpu;
 777                 grouptaskqueue_enqueue(qgroup->tqg_queue[i].tgc_taskq,
 778                                        &gtask->bt_task);
 779         }
 780 }
 781
 782 struct taskqgroup *
 783 taskqgroup_create(const char *name, int cnt, int stride)
 784 {
 785         struct taskqgroup *qgroup;
 786         int cpu, i, j;
 787
 788         qgroup = kmalloc(sizeof(*qgroup), M_GTASKQUEUE, M_WAITOK | M_ZERO);
 789         lockinit(&qgroup->tqg_lock, "taskqgroup", 0, 0);
 790         qgroup->tqg_name = name;
 791         qgroup->tqg_cnt = cnt;
 792
 793         for (cpu = i = 0; i < cnt; i++) {
 794                 taskqgroup_cpu_create(qgroup, i, cpu);
 795                 for (j = 0; j < stride; j++)
 796                         cpu = (cpu + 1) % ncpus;
 797         }
 798         return (qgroup);
 799 }
 800
 801 void
 802 taskqgroup_destroy(struct taskqgroup *qgroup)
 803 {
 804 }
 805
 806 void
 807 taskqgroup_drain_all(struct taskqgroup *tqg)
 808 {
 809         struct gtaskqueue *q;
 810
 811         for (int i = 0; i < ncpus; i++) {
 812                 q = tqg->tqg_queue[i].tgc_taskq;
 813                 if (q == NULL)
 814                         continue;
 815                 gtaskqueue_drain_all(q);
 816         }
 817 }