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 __FBSDID("$FreeBSD$");
31
32 #include <sys/param.h>
33 #include <sys/systm.h>
34 #include <sys/bus.h>
35 #include <sys/cpuset.h>
36 #include <sys/interrupt.h>
37 #include <sys/kernel.h>
38 #include <sys/kthread.h>
39 #include <sys/libkern.h>
40 #include <sys/limits.h>
41 #include <sys/lock.h>
42 #include <sys/malloc.h>
43 #include <sys/mutex.h>
44 #include <sys/proc.h>
45 #include <sys/sched.h>
46 #include <sys/smp.h>
47 #include <sys/gtaskqueue.h>
48 #include <sys/unistd.h>
49 #include <machine/stdarg.h>
50
51 static MALLOC_DEFINE(M_GTASKQUEUE, "gtaskqueue", "Group Task Queues");
52 static void gtaskqueue_thread_enqueue(void *);
53 static void gtaskqueue_thread_loop(void *arg);
54 static int task_is_running(struct gtaskqueue *queue, struct gtask *gtask);
55 static void gtaskqueue_drain_locked(struct gtaskqueue *queue, struct gtask *gtask);
56
57 TASKQGROUP_DEFINE(softirq, mp_ncpus, 1);
58
59 struct gtaskqueue_busy {
60 struct gtask *tb_running;
61 u_int tb_seq;
62 LIST_ENTRY(gtaskqueue_busy) tb_link;
63 };
64
65 typedef void (*gtaskqueue_enqueue_fn)(void *context);
66
67 struct gtaskqueue {
68 STAILQ_HEAD(, gtask) tq_queue;
69 LIST_HEAD(, gtaskqueue_busy) tq_active;
70 u_int tq_seq;
71 int tq_callouts;
72 struct mtx_padalign tq_mutex;
73 gtaskqueue_enqueue_fn tq_enqueue;
74 void *tq_context;
75 char *tq_name;
76 struct thread **tq_threads;
77 int tq_tcount;
78 int tq_spin;
79 int tq_flags;
80 taskqueue_callback_fn tq_callbacks[TASKQUEUE_NUM_CALLBACKS];
81 void *tq_cb_contexts[TASKQUEUE_NUM_CALLBACKS];
82 };
83
84 #define TQ_FLAGS_ACTIVE (1 << 0)
85 #define TQ_FLAGS_BLOCKED (1 << 1)
86 #define TQ_FLAGS_UNLOCKED_ENQUEUE (1 << 2)
87
88 #define DT_CALLOUT_ARMED (1 << 0)
89
90 #define TQ_LOCK(tq) \
91 do { \
92 if ((tq)->tq_spin) \
93 mtx_lock_spin(&(tq)->tq_mutex); \
94 else \
95 mtx_lock(&(tq)->tq_mutex); \
96 } while (0)
97 #define TQ_ASSERT_LOCKED(tq) mtx_assert(&(tq)->tq_mutex, MA_OWNED)
98
99 #define TQ_UNLOCK(tq) \
100 do { \
101 if ((tq)->tq_spin) \
102 mtx_unlock_spin(&(tq)->tq_mutex); \
103 else \
104 mtx_unlock(&(tq)->tq_mutex); \
105 } while (0)
106 #define TQ_ASSERT_UNLOCKED(tq) mtx_assert(&(tq)->tq_mutex, MA_NOTOWNED)
107
108 #ifdef INVARIANTS
109 static void
110 gtask_dump(struct gtask *gtask)
111 {
112 printf("gtask: %p ta_flags=%x ta_priority=%d ta_func=%p ta_context=%p\n",
113 gtask, gtask->ta_flags, gtask->ta_priority, gtask->ta_func, gtask->ta_context);
114 }
115 #endif
116
117 static __inline int
118 TQ_SLEEP(struct gtaskqueue *tq, void *p, const char *wm)
119 {
120 if (tq->tq_spin)
121 return (msleep_spin(p, (struct mtx *)&tq->tq_mutex, wm, 0));
122 return (msleep(p, &tq->tq_mutex, 0, wm, 0));
123 }
124
125 static struct gtaskqueue *
126 _gtaskqueue_create(const char *name, int mflags,
127 taskqueue_enqueue_fn enqueue, void *context,
128 int mtxflags, const char *mtxname __unused)
129 {
130 struct gtaskqueue *queue;
131 char *tq_name;
132
133 tq_name = malloc(TASKQUEUE_NAMELEN, M_GTASKQUEUE, mflags | M_ZERO);
134 if (!tq_name)
135 return (NULL);
136
137 snprintf(tq_name, TASKQUEUE_NAMELEN, "%s", (name) ? name : "taskqueue");
138
139 queue = malloc(sizeof(struct gtaskqueue), M_GTASKQUEUE, mflags | M_ZERO);
140 if (!queue) {
141 free(tq_name, M_GTASKQUEUE);
142 return (NULL);
143 }
144
145 STAILQ_INIT(&queue->tq_queue);
146 LIST_INIT(&queue->tq_active);
147 queue->tq_enqueue = enqueue;
148 queue->tq_context = context;
149 queue->tq_name = tq_name;
150 queue->tq_spin = (mtxflags & MTX_SPIN) != 0;
151 queue->tq_flags |= TQ_FLAGS_ACTIVE;
152 if (enqueue == gtaskqueue_thread_enqueue)
153 queue->tq_flags |= TQ_FLAGS_UNLOCKED_ENQUEUE;
154 mtx_init(&queue->tq_mutex, tq_name, NULL, mtxflags);
155
156 return (queue);
157 }
158
159
160 /*
161 * Signal a taskqueue thread to terminate.
162 */
163 static void
164 gtaskqueue_terminate(struct thread **pp, struct gtaskqueue *tq)
165 {
166
167 while (tq->tq_tcount > 0 || tq->tq_callouts > 0) {
168 wakeup(tq);
169 TQ_SLEEP(tq, pp, "gtq_destroy");
170 }
171 }
172
173 static void
174 gtaskqueue_free(struct gtaskqueue *queue)
175 {
176
177 TQ_LOCK(queue);
178 queue->tq_flags &= ~TQ_FLAGS_ACTIVE;
179 gtaskqueue_terminate(queue->tq_threads, queue);
180 KASSERT(LIST_EMPTY(&queue->tq_active), ("Tasks still running?"));
181 KASSERT(queue->tq_callouts == 0, ("Armed timeout tasks"));
182 mtx_destroy(&queue->tq_mutex);
183 free(queue->tq_threads, M_GTASKQUEUE);
184 free(queue->tq_name, M_GTASKQUEUE);
185 free(queue, M_GTASKQUEUE);
186 }
187
188 /*
189 * Wait for all to complete, then prevent it from being enqueued
190 */
191 void
192 grouptask_block(struct grouptask *grouptask)
193 {
194 struct gtaskqueue *queue = grouptask->gt_taskqueue;
195 struct gtask *gtask = &grouptask->gt_task;
196
197 #ifdef INVARIANTS
198 if (queue == NULL) {
199 gtask_dump(gtask);
200 panic("queue == NULL");
201 }
202 #endif
203 TQ_LOCK(queue);
204 gtask->ta_flags |= TASK_NOENQUEUE;
205 gtaskqueue_drain_locked(queue, gtask);
206 TQ_UNLOCK(queue);
207 }
208
209 void
210 grouptask_unblock(struct grouptask *grouptask)
211 {
212 struct gtaskqueue *queue = grouptask->gt_taskqueue;
213 struct gtask *gtask = &grouptask->gt_task;
214
215 #ifdef INVARIANTS
216 if (queue == NULL) {
217 gtask_dump(gtask);
218 panic("queue == NULL");
219 }
220 #endif
221 TQ_LOCK(queue);
222 gtask->ta_flags &= ~TASK_NOENQUEUE;
223 TQ_UNLOCK(queue);
224 }
225
226 int
227 grouptaskqueue_enqueue(struct gtaskqueue *queue, struct gtask *gtask)
228 {
229 #ifdef INVARIANTS
230 if (queue == NULL) {
231 gtask_dump(gtask);
232 panic("queue == NULL");
233 }
234 #endif
235 TQ_LOCK(queue);
236 if (gtask->ta_flags & TASK_ENQUEUED) {
237 TQ_UNLOCK(queue);
238 return (0);
239 }
240 if (gtask->ta_flags & TASK_NOENQUEUE) {
241 TQ_UNLOCK(queue);
242 return (EAGAIN);
243 }
244 STAILQ_INSERT_TAIL(&queue->tq_queue, gtask, ta_link);
245 gtask->ta_flags |= TASK_ENQUEUED;
246 TQ_UNLOCK(queue);
247 if ((queue->tq_flags & TQ_FLAGS_BLOCKED) == 0)
248 queue->tq_enqueue(queue->tq_context);
249 return (0);
250 }
251
252 static void
253 gtaskqueue_task_nop_fn(void *context)
254 {
255 }
256
257 /*
258 * Block until all currently queued tasks in this taskqueue
259 * have begun execution. Tasks queued during execution of
260 * this function are ignored.
261 */
262 static void
263 gtaskqueue_drain_tq_queue(struct gtaskqueue *queue)
264 {
265 struct gtask t_barrier;
266
267 if (STAILQ_EMPTY(&queue->tq_queue))
268 return;
269
270 /*
271 * Enqueue our barrier after all current tasks, but with
272 * the highest priority so that newly queued tasks cannot
273 * pass it. Because of the high priority, we can not use
274 * taskqueue_enqueue_locked directly (which drops the lock
275 * anyway) so just insert it at tail while we have the
276 * queue lock.
277 */
278 GTASK_INIT(&t_barrier, 0, USHRT_MAX, gtaskqueue_task_nop_fn, &t_barrier);
279 STAILQ_INSERT_TAIL(&queue->tq_queue, &t_barrier, ta_link);
280 t_barrier.ta_flags |= TASK_ENQUEUED;
281
282 /*
283 * Once the barrier has executed, all previously queued tasks
284 * have completed or are currently executing.
285 */
286 while (t_barrier.ta_flags & TASK_ENQUEUED)
287 TQ_SLEEP(queue, &t_barrier, "gtq_qdrain");
288 }
289
290 /*
291 * Block until all currently executing tasks for this taskqueue
292 * complete. Tasks that begin execution during the execution
293 * of this function are ignored.
294 */
295 static void
296 gtaskqueue_drain_tq_active(struct gtaskqueue *queue)
297 {
298 struct gtaskqueue_busy *tb;
299 u_int seq;
300
301 if (LIST_EMPTY(&queue->tq_active))
302 return;
303
304 /* Block taskq_terminate().*/
305 queue->tq_callouts++;
306
307 /* Wait for any active task with sequence from the past. */
308 seq = queue->tq_seq;
309 restart:
310 LIST_FOREACH(tb, &queue->tq_active, tb_link) {
311 if ((int)(tb->tb_seq - seq) <= 0) {
312 TQ_SLEEP(queue, tb->tb_running, "gtq_adrain");
313 goto restart;
314 }
315 }
316
317 /* Release taskqueue_terminate(). */
318 queue->tq_callouts--;
319 if ((queue->tq_flags & TQ_FLAGS_ACTIVE) == 0)
320 wakeup_one(queue->tq_threads);
321 }
322
323 void
324 gtaskqueue_block(struct gtaskqueue *queue)
325 {
326
327 TQ_LOCK(queue);
328 queue->tq_flags |= TQ_FLAGS_BLOCKED;
329 TQ_UNLOCK(queue);
330 }
331
332 void
333 gtaskqueue_unblock(struct gtaskqueue *queue)
334 {
335
336 TQ_LOCK(queue);
337 queue->tq_flags &= ~TQ_FLAGS_BLOCKED;
338 if (!STAILQ_EMPTY(&queue->tq_queue))
339 queue->tq_enqueue(queue->tq_context);
340 TQ_UNLOCK(queue);
341 }
342
343 static void
344 gtaskqueue_run_locked(struct gtaskqueue *queue)
345 {
346 struct gtaskqueue_busy tb;
347 struct gtask *gtask;
348
349 KASSERT(queue != NULL, ("tq is NULL"));
350 TQ_ASSERT_LOCKED(queue);
351 tb.tb_running = NULL;
352 LIST_INSERT_HEAD(&queue->tq_active, &tb, tb_link);
353
354 while ((gtask = STAILQ_FIRST(&queue->tq_queue)) != NULL) {
355 STAILQ_REMOVE_HEAD(&queue->tq_queue, ta_link);
356 gtask->ta_flags &= ~TASK_ENQUEUED;
357 tb.tb_running = gtask;
358 tb.tb_seq = ++queue->tq_seq;
359 TQ_UNLOCK(queue);
360
361 KASSERT(gtask->ta_func != NULL, ("task->ta_func is NULL"));
362 gtask->ta_func(gtask->ta_context);
363
364 TQ_LOCK(queue);
365 wakeup(gtask);
366 }
367 LIST_REMOVE(&tb, tb_link);
368 }
369
370 static int
371 task_is_running(struct gtaskqueue *queue, struct gtask *gtask)
372 {
373 struct gtaskqueue_busy *tb;
374
375 TQ_ASSERT_LOCKED(queue);
376 LIST_FOREACH(tb, &queue->tq_active, tb_link) {
377 if (tb->tb_running == gtask)
378 return (1);
379 }
380 return (0);
381 }
382
383 static int
384 gtaskqueue_cancel_locked(struct gtaskqueue *queue, struct gtask *gtask)
385 {
386
387 if (gtask->ta_flags & TASK_ENQUEUED)
388 STAILQ_REMOVE(&queue->tq_queue, gtask, gtask, ta_link);
389 gtask->ta_flags &= ~TASK_ENQUEUED;
390 return (task_is_running(queue, gtask) ? EBUSY : 0);
391 }
392
393 int
394 gtaskqueue_cancel(struct gtaskqueue *queue, struct gtask *gtask)
395 {
396 int error;
397
398 TQ_LOCK(queue);
399 error = gtaskqueue_cancel_locked(queue, gtask);
400 TQ_UNLOCK(queue);
401
402 return (error);
403 }
404
405 static void
406 gtaskqueue_drain_locked(struct gtaskqueue *queue, struct gtask *gtask)
407 {
408 while ((gtask->ta_flags & TASK_ENQUEUED) || task_is_running(queue, gtask))
409 TQ_SLEEP(queue, gtask, "gtq_drain");
410 }
411
412 void
413 gtaskqueue_drain(struct gtaskqueue *queue, struct gtask *gtask)
414 {
415
416 if (!queue->tq_spin)
417 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL, __func__);
418
419 TQ_LOCK(queue);
420 gtaskqueue_drain_locked(queue, gtask);
421 TQ_UNLOCK(queue);
422 }
423
424 void
425 gtaskqueue_drain_all(struct gtaskqueue *queue)
426 {
427
428 if (!queue->tq_spin)
429 WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL, __func__);
430
431 TQ_LOCK(queue);
432 gtaskqueue_drain_tq_queue(queue);
433 gtaskqueue_drain_tq_active(queue);
434 TQ_UNLOCK(queue);
435 }
436
437 static int
438 _gtaskqueue_start_threads(struct gtaskqueue **tqp, int count, int pri,
439 cpuset_t *mask, const char *name, va_list ap)
440 {
441 char ktname[MAXCOMLEN + 1];
442 struct thread *td;
443 struct gtaskqueue *tq;
444 int i, error;
445
446 if (count <= 0)
447 return (EINVAL);
448
449 vsnprintf(ktname, sizeof(ktname), name, ap);
450 tq = *tqp;
451
452 tq->tq_threads = malloc(sizeof(struct thread *) * count, M_GTASKQUEUE,
453 M_NOWAIT | M_ZERO);
454 if (tq->tq_threads == NULL) {
455 printf("%s: no memory for %s threads\n", __func__, ktname);
456 return (ENOMEM);
457 }
458
459 for (i = 0; i < count; i++) {
460 if (count == 1)
461 error = kthread_add(gtaskqueue_thread_loop, tqp, NULL,
462 &tq->tq_threads[i], RFSTOPPED, 0, "%s", ktname);
463 else
464 error = kthread_add(gtaskqueue_thread_loop, tqp, NULL,
465 &tq->tq_threads[i], RFSTOPPED, 0,
466 "%s_%d", ktname, i);
467 if (error) {
468 /* should be ok to continue, taskqueue_free will dtrt */
469 printf("%s: kthread_add(%s): error %d", __func__,
470 ktname, error);
471 tq->tq_threads[i] = NULL; /* paranoid */
472 } else
473 tq->tq_tcount++;
474 }
475 for (i = 0; i < count; i++) {
476 if (tq->tq_threads[i] == NULL)
477 continue;
478 td = tq->tq_threads[i];
479 if (mask) {
480 error = cpuset_setthread(td->td_tid, mask);
481 /*
482 * Failing to pin is rarely an actual fatal error;
483 * it'll just affect performance.
484 */
485 if (error)
486 printf("%s: curthread=%llu: can't pin; "
487 "error=%d\n",
488 __func__,
489 (unsigned long long) td->td_tid,
490 error);
491 }
492 thread_lock(td);
493 sched_prio(td, pri);
494 sched_add(td, SRQ_BORING);
495 thread_unlock(td);
496 }
497
498 return (0);
499 }
500
501 static int
502 gtaskqueue_start_threads(struct gtaskqueue **tqp, int count, int pri,
503 const char *name, ...)
504 {
505 va_list ap;
506 int error;
507
508 va_start(ap, name);
509 error = _gtaskqueue_start_threads(tqp, count, pri, NULL, name, ap);
510 va_end(ap);
511 return (error);
512 }
513
514 static inline void
515 gtaskqueue_run_callback(struct gtaskqueue *tq,
516 enum taskqueue_callback_type cb_type)
517 {
518 taskqueue_callback_fn tq_callback;
519
520 TQ_ASSERT_UNLOCKED(tq);
521 tq_callback = tq->tq_callbacks[cb_type];
522 if (tq_callback != NULL)
523 tq_callback(tq->tq_cb_contexts[cb_type]);
524 }
525
526 static void
527 gtaskqueue_thread_loop(void *arg)
528 {
529 struct gtaskqueue **tqp, *tq;
530
531 tqp = arg;
532 tq = *tqp;
533 gtaskqueue_run_callback(tq, TASKQUEUE_CALLBACK_TYPE_INIT);
534 TQ_LOCK(tq);
535 while ((tq->tq_flags & TQ_FLAGS_ACTIVE) != 0) {
536 /* XXX ? */
537 gtaskqueue_run_locked(tq);
538 /*
539 * Because taskqueue_run() can drop tq_mutex, we need to
540 * check if the TQ_FLAGS_ACTIVE flag wasn't removed in the
541 * meantime, which means we missed a wakeup.
542 */
543 if ((tq->tq_flags & TQ_FLAGS_ACTIVE) == 0)
544 break;
545 TQ_SLEEP(tq, tq, "-");
546 }
547 gtaskqueue_run_locked(tq);
548 /*
549 * This thread is on its way out, so just drop the lock temporarily
550 * in order to call the shutdown callback. This allows the callback
551 * to look at the taskqueue, even just before it dies.
552 */
553 TQ_UNLOCK(tq);
554 gtaskqueue_run_callback(tq, TASKQUEUE_CALLBACK_TYPE_SHUTDOWN);
555 TQ_LOCK(tq);
556
557 /* rendezvous with thread that asked us to terminate */
558 tq->tq_tcount--;
559 wakeup_one(tq->tq_threads);
560 TQ_UNLOCK(tq);
561 kthread_exit();
562 }
563
564 static void
565 gtaskqueue_thread_enqueue(void *context)
566 {
567 struct gtaskqueue **tqp, *tq;
568
569 tqp = context;
570 tq = *tqp;
571 wakeup_any(tq);
572 }
573
574
575 static struct gtaskqueue *
576 gtaskqueue_create_fast(const char *name, int mflags,
577 taskqueue_enqueue_fn enqueue, void *context)
578 {
579 return _gtaskqueue_create(name, mflags, enqueue, context,
580 MTX_SPIN, "fast_taskqueue");
581 }
582
583
584 struct taskqgroup_cpu {
585 LIST_HEAD(, grouptask) tgc_tasks;
586 struct gtaskqueue *tgc_taskq;
587 int tgc_cnt;
588 int tgc_cpu;
589 };
590
591 struct taskqgroup {
592 struct taskqgroup_cpu tqg_queue[MAXCPU];
593 struct mtx tqg_lock;
594 const char * tqg_name;
595 int tqg_adjusting;
596 int tqg_stride;
597 int tqg_cnt;
598 };
599
600 struct taskq_bind_task {
601 struct gtask bt_task;
602 int bt_cpuid;
603 };
604
605 static void
606 taskqgroup_cpu_create(struct taskqgroup *qgroup, int idx, int cpu)
607 {
608 struct taskqgroup_cpu *qcpu;
609
610 qcpu = &qgroup->tqg_queue[idx];
611 LIST_INIT(&qcpu->tgc_tasks);
612 qcpu->tgc_taskq = gtaskqueue_create_fast(NULL, M_WAITOK,
613 taskqueue_thread_enqueue, &qcpu->tgc_taskq);
614 gtaskqueue_start_threads(&qcpu->tgc_taskq, 1, PI_SOFT,
615 "%s_%d", qgroup->tqg_name, idx);
616 qcpu->tgc_cpu = cpu;
617 }
618
619 static void
620 taskqgroup_cpu_remove(struct taskqgroup *qgroup, int idx)
621 {
622
623 gtaskqueue_free(qgroup->tqg_queue[idx].tgc_taskq);
624 }
625
626 /*
627 * Find the taskq with least # of tasks that doesn't currently have any
628 * other queues from the uniq identifier.
629 */
630 static int
631 taskqgroup_find(struct taskqgroup *qgroup, void *uniq)
632 {
633 struct grouptask *n;
634 int i, idx, mincnt;
635 int strict;
636
637 mtx_assert(&qgroup->tqg_lock, MA_OWNED);
638 if (qgroup->tqg_cnt == 0)
639 return (0);
640 idx = -1;
641 mincnt = INT_MAX;
642 /*
643 * Two passes; First scan for a queue with the least tasks that
644 * does not already service this uniq id. If that fails simply find
645 * the queue with the least total tasks;
646 */
647 for (strict = 1; mincnt == INT_MAX; strict = 0) {
648 for (i = 0; i < qgroup->tqg_cnt; i++) {
649 if (qgroup->tqg_queue[i].tgc_cnt > mincnt)
650 continue;
651 if (strict) {
652 LIST_FOREACH(n,
653 &qgroup->tqg_queue[i].tgc_tasks, gt_list)
654 if (n->gt_uniq == uniq)
655 break;
656 if (n != NULL)
657 continue;
658 }
659 mincnt = qgroup->tqg_queue[i].tgc_cnt;
660 idx = i;
661 }
662 }
663 if (idx == -1)
664 panic("%s: failed to pick a qid.", __func__);
665
666 return (idx);
667 }
668
669 /*
670 * smp_started is unusable since it is not set for UP kernels or even for
671 * SMP kernels when there is 1 CPU. This is usually handled by adding a
672 * (mp_ncpus == 1) test, but that would be broken here since we need to
673 * to synchronize with the SI_SUB_SMP ordering. Even in the pure SMP case
674 * smp_started only gives a fuzzy ordering relative to SI_SUB_SMP.
675 *
676 * So maintain our own flag. It must be set after all CPUs are started
677 * and before SI_SUB_SMP:SI_ORDER_ANY so that the SYSINIT for delayed
678 * adjustment is properly delayed. SI_ORDER_FOURTH is clearly before
679 * SI_ORDER_ANY and unclearly after the CPUs are started. It would be
680 * simpler for adjustment to pass a flag indicating if it is delayed.
681 */
682
683 static int tqg_smp_started;
684
685 static void
686 tqg_record_smp_started(void *arg)
687 {
688 tqg_smp_started = 1;
689 }
690
691 SYSINIT(tqg_record_smp_started, SI_SUB_SMP, SI_ORDER_FOURTH,
692 tqg_record_smp_started, NULL);
693
694 void
695 taskqgroup_attach(struct taskqgroup *qgroup, struct grouptask *gtask,
696 void *uniq, int irq, const char *name)
697 {
698 cpuset_t mask;
699 int qid, error;
700
701 gtask->gt_uniq = uniq;
702 snprintf(gtask->gt_name, GROUPTASK_NAMELEN, "%s", name ? name : "grouptask");
703 gtask->gt_irq = irq;
704 gtask->gt_cpu = -1;
705 mtx_lock(&qgroup->tqg_lock);
706 qid = taskqgroup_find(qgroup, uniq);
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 if (irq != -1 && tqg_smp_started) {
711 gtask->gt_cpu = qgroup->tqg_queue[qid].tgc_cpu;
712 CPU_ZERO(&mask);
713 CPU_SET(qgroup->tqg_queue[qid].tgc_cpu, &mask);
714 mtx_unlock(&qgroup->tqg_lock);
715 error = intr_setaffinity(irq, CPU_WHICH_IRQ, &mask);
716 if (error)
717 printf("%s: binding interrupt failed for %s: %d\n",
718 __func__, gtask->gt_name, error);
719 } else
720 mtx_unlock(&qgroup->tqg_lock);
721 }
722
723 static void
724 taskqgroup_attach_deferred(struct taskqgroup *qgroup, struct grouptask *gtask)
725 {
726 cpuset_t mask;
727 int qid, cpu, error;
728
729 mtx_lock(&qgroup->tqg_lock);
730 qid = taskqgroup_find(qgroup, gtask->gt_uniq);
731 cpu = qgroup->tqg_queue[qid].tgc_cpu;
732 if (gtask->gt_irq != -1) {
733 mtx_unlock(&qgroup->tqg_lock);
734
735 CPU_ZERO(&mask);
736 CPU_SET(cpu, &mask);
737 error = intr_setaffinity(gtask->gt_irq, CPU_WHICH_IRQ, &mask);
738 mtx_lock(&qgroup->tqg_lock);
739 if (error)
740 printf("%s: binding interrupt failed for %s: %d\n",
741 __func__, gtask->gt_name, error);
742
743 }
744 qgroup->tqg_queue[qid].tgc_cnt++;
745 LIST_INSERT_HEAD(&qgroup->tqg_queue[qid].tgc_tasks, gtask, gt_list);
746 MPASS(qgroup->tqg_queue[qid].tgc_taskq != NULL);
747 gtask->gt_taskqueue = qgroup->tqg_queue[qid].tgc_taskq;
748 mtx_unlock(&qgroup->tqg_lock);
749 }
750
751 int
752 taskqgroup_attach_cpu(struct taskqgroup *qgroup, struct grouptask *gtask,
753 void *uniq, int cpu, int irq, const char *name)
754 {
755 cpuset_t mask;
756 int i, qid, error;
757
758 qid = -1;
759 gtask->gt_uniq = uniq;
760 snprintf(gtask->gt_name, GROUPTASK_NAMELEN, "%s", name ? name : "grouptask");
761 gtask->gt_irq = irq;
762 gtask->gt_cpu = cpu;
763 mtx_lock(&qgroup->tqg_lock);
764 if (tqg_smp_started) {
765 for (i = 0; i < qgroup->tqg_cnt; i++)
766 if (qgroup->tqg_queue[i].tgc_cpu == cpu) {
767 qid = i;
768 break;
769 }
770 if (qid == -1) {
771 mtx_unlock(&qgroup->tqg_lock);
772 printf("%s: qid not found for %s cpu=%d\n", __func__, gtask->gt_name, cpu);
773 return (EINVAL);
774 }
775 } else
776 qid = 0;
777 qgroup->tqg_queue[qid].tgc_cnt++;
778 LIST_INSERT_HEAD(&qgroup->tqg_queue[qid].tgc_tasks, gtask, gt_list);
779 gtask->gt_taskqueue = qgroup->tqg_queue[qid].tgc_taskq;
780 cpu = qgroup->tqg_queue[qid].tgc_cpu;
781 mtx_unlock(&qgroup->tqg_lock);
782
783 CPU_ZERO(&mask);
784 CPU_SET(cpu, &mask);
785 if (irq != -1 && tqg_smp_started) {
786 error = intr_setaffinity(irq, CPU_WHICH_IRQ, &mask);
787 if (error)
788 printf("%s: binding interrupt failed for %s: %d\n",
789 __func__, gtask->gt_name, error);
790 }
791 return (0);
792 }
793
794 static int
795 taskqgroup_attach_cpu_deferred(struct taskqgroup *qgroup, struct grouptask *gtask)
796 {
797 cpuset_t mask;
798 int i, qid, irq, cpu, error;
799
800 qid = -1;
801 irq = gtask->gt_irq;
802 cpu = gtask->gt_cpu;
803 MPASS(tqg_smp_started);
804 mtx_lock(&qgroup->tqg_lock);
805 for (i = 0; i < qgroup->tqg_cnt; i++)
806 if (qgroup->tqg_queue[i].tgc_cpu == cpu) {
807 qid = i;
808 break;
809 }
810 if (qid == -1) {
811 mtx_unlock(&qgroup->tqg_lock);
812 printf("%s: qid not found for %s cpu=%d\n", __func__, gtask->gt_name, cpu);
813 return (EINVAL);
814 }
815 qgroup->tqg_queue[qid].tgc_cnt++;
816 LIST_INSERT_HEAD(&qgroup->tqg_queue[qid].tgc_tasks, gtask, gt_list);
817 MPASS(qgroup->tqg_queue[qid].tgc_taskq != NULL);
818 gtask->gt_taskqueue = qgroup->tqg_queue[qid].tgc_taskq;
819 mtx_unlock(&qgroup->tqg_lock);
820
821 CPU_ZERO(&mask);
822 CPU_SET(cpu, &mask);
823
824 if (irq != -1) {
825 error = intr_setaffinity(irq, CPU_WHICH_IRQ, &mask);
826 if (error)
827 printf("%s: binding interrupt failed for %s: %d\n",
828 __func__, gtask->gt_name, error);
829 }
830 return (0);
831 }
832
833 void
834 taskqgroup_detach(struct taskqgroup *qgroup, struct grouptask *gtask)
835 {
836 int i;
837
838 grouptask_block(gtask);
839 mtx_lock(&qgroup->tqg_lock);
840 for (i = 0; i < qgroup->tqg_cnt; i++)
841 if (qgroup->tqg_queue[i].tgc_taskq == gtask->gt_taskqueue)
842 break;
843 if (i == qgroup->tqg_cnt)
844 panic("%s: task %s not in group", __func__, gtask->gt_name);
845 qgroup->tqg_queue[i].tgc_cnt--;
846 LIST_REMOVE(gtask, gt_list);
847 mtx_unlock(&qgroup->tqg_lock);
848 gtask->gt_taskqueue = NULL;
849 gtask->gt_task.ta_flags &= ~TASK_NOENQUEUE;
850 }
851
852 static void
853 taskqgroup_binder(void *ctx)
854 {
855 struct taskq_bind_task *gtask = (struct taskq_bind_task *)ctx;
856 cpuset_t mask;
857 int error;
858
859 CPU_ZERO(&mask);
860 CPU_SET(gtask->bt_cpuid, &mask);
861 error = cpuset_setthread(curthread->td_tid, &mask);
862 thread_lock(curthread);
863 sched_bind(curthread, gtask->bt_cpuid);
864 thread_unlock(curthread);
865
866 if (error)
867 printf("%s: binding curthread failed: %d\n", __func__, error);
868 free(gtask, M_DEVBUF);
869 }
870
871 static void
872 taskqgroup_bind(struct taskqgroup *qgroup)
873 {
874 struct taskq_bind_task *gtask;
875 int i;
876
877 /*
878 * Bind taskqueue threads to specific CPUs, if they have been assigned
879 * one.
880 */
881 if (qgroup->tqg_cnt == 1)
882 return;
883
884 for (i = 0; i < qgroup->tqg_cnt; i++) {
885 gtask = malloc(sizeof (*gtask), M_DEVBUF, M_WAITOK);
886 GTASK_INIT(>ask->bt_task, 0, 0, taskqgroup_binder, gtask);
887 gtask->bt_cpuid = qgroup->tqg_queue[i].tgc_cpu;
888 grouptaskqueue_enqueue(qgroup->tqg_queue[i].tgc_taskq,
889 >ask->bt_task);
890 }
891 }
892
893 static int
894 _taskqgroup_adjust(struct taskqgroup *qgroup, int cnt, int stride)
895 {
896 LIST_HEAD(, grouptask) gtask_head = LIST_HEAD_INITIALIZER(NULL);
897 struct grouptask *gtask;
898 int i, k, old_cnt, old_cpu, cpu;
899
900 mtx_assert(&qgroup->tqg_lock, MA_OWNED);
901
902 if (cnt < 1 || cnt * stride > mp_ncpus || !tqg_smp_started) {
903 printf("%s: failed cnt: %d stride: %d "
904 "mp_ncpus: %d tqg_smp_started: %d\n",
905 __func__, cnt, stride, mp_ncpus, tqg_smp_started);
906 return (EINVAL);
907 }
908 if (qgroup->tqg_adjusting) {
909 printf("%s failed: adjusting\n", __func__);
910 return (EBUSY);
911 }
912 qgroup->tqg_adjusting = 1;
913 old_cnt = qgroup->tqg_cnt;
914 old_cpu = 0;
915 if (old_cnt < cnt)
916 old_cpu = qgroup->tqg_queue[old_cnt].tgc_cpu;
917 mtx_unlock(&qgroup->tqg_lock);
918 /*
919 * Set up queue for tasks added before boot.
920 */
921 if (old_cnt == 0) {
922 LIST_SWAP(>ask_head, &qgroup->tqg_queue[0].tgc_tasks,
923 grouptask, gt_list);
924 qgroup->tqg_queue[0].tgc_cnt = 0;
925 }
926
927 /*
928 * If new taskq threads have been added.
929 */
930 cpu = old_cpu;
931 for (i = old_cnt; i < cnt; i++) {
932 taskqgroup_cpu_create(qgroup, i, cpu);
933
934 for (k = 0; k < stride; k++)
935 cpu = CPU_NEXT(cpu);
936 }
937 mtx_lock(&qgroup->tqg_lock);
938 qgroup->tqg_cnt = cnt;
939 qgroup->tqg_stride = stride;
940
941 /*
942 * Adjust drivers to use new taskqs.
943 */
944 for (i = 0; i < old_cnt; i++) {
945 while ((gtask = LIST_FIRST(&qgroup->tqg_queue[i].tgc_tasks))) {
946 LIST_REMOVE(gtask, gt_list);
947 qgroup->tqg_queue[i].tgc_cnt--;
948 LIST_INSERT_HEAD(>ask_head, gtask, gt_list);
949 }
950 }
951 mtx_unlock(&qgroup->tqg_lock);
952
953 while ((gtask = LIST_FIRST(>ask_head))) {
954 LIST_REMOVE(gtask, gt_list);
955 if (gtask->gt_cpu == -1)
956 taskqgroup_attach_deferred(qgroup, gtask);
957 else if (taskqgroup_attach_cpu_deferred(qgroup, gtask))
958 taskqgroup_attach_deferred(qgroup, gtask);
959 }
960
961 #ifdef INVARIANTS
962 mtx_lock(&qgroup->tqg_lock);
963 for (i = 0; i < qgroup->tqg_cnt; i++) {
964 MPASS(qgroup->tqg_queue[i].tgc_taskq != NULL);
965 LIST_FOREACH(gtask, &qgroup->tqg_queue[i].tgc_tasks, gt_list)
966 MPASS(gtask->gt_taskqueue != NULL);
967 }
968 mtx_unlock(&qgroup->tqg_lock);
969 #endif
970 /*
971 * If taskq thread count has been reduced.
972 */
973 for (i = cnt; i < old_cnt; i++)
974 taskqgroup_cpu_remove(qgroup, i);
975
976 taskqgroup_bind(qgroup);
977
978 mtx_lock(&qgroup->tqg_lock);
979 qgroup->tqg_adjusting = 0;
980
981 return (0);
982 }
983
984 int
985 taskqgroup_adjust(struct taskqgroup *qgroup, int cnt, int stride)
986 {
987 int error;
988
989 mtx_lock(&qgroup->tqg_lock);
990 error = _taskqgroup_adjust(qgroup, cnt, stride);
991 mtx_unlock(&qgroup->tqg_lock);
992
993 return (error);
994 }
995
996 struct taskqgroup *
997 taskqgroup_create(const char *name)
998 {
999 struct taskqgroup *qgroup;
1000
1001 qgroup = malloc(sizeof(*qgroup), M_GTASKQUEUE, M_WAITOK | M_ZERO);
1002 mtx_init(&qgroup->tqg_lock, "taskqgroup", NULL, MTX_DEF);
1003 qgroup->tqg_name = name;
1004 LIST_INIT(&qgroup->tqg_queue[0].tgc_tasks);
1005
1006 return (qgroup);
1007 }
1008
1009 void
1010 taskqgroup_destroy(struct taskqgroup *qgroup)
1011 {
1012 }
1013
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