1 #include <linux/kernel.h>
2 #include <linux/module.h>
3 #include <linux/backing-dev.h>
5 #include <linux/blkdev.h>
7 #include <linux/init.h>
8 #include <linux/slab.h>
9 #include <linux/workqueue.h>
10 #include <linux/smp.h>
11 #include <linux/llist.h>
12 #include <linux/list_sort.h>
13 #include <linux/cpu.h>
14 #include <linux/cache.h>
15 #include <linux/sched/sysctl.h>
16 #include <linux/delay.h>
18 #include <trace/events/block.h>
20 #include <linux/blk-mq.h>
23 #include "blk-mq-tag.h"
25 static DEFINE_MUTEX(all_q_mutex
);
26 static LIST_HEAD(all_q_list
);
28 static void __blk_mq_run_hw_queue(struct blk_mq_hw_ctx
*hctx
);
30 static struct blk_mq_ctx
*__blk_mq_get_ctx(struct request_queue
*q
,
33 return per_cpu_ptr(q
->queue_ctx
, cpu
);
37 * This assumes per-cpu software queueing queues. They could be per-node
38 * as well, for instance. For now this is hardcoded as-is. Note that we don't
39 * care about preemption, since we know the ctx's are persistent. This does
40 * mean that we can't rely on ctx always matching the currently running CPU.
42 static struct blk_mq_ctx
*blk_mq_get_ctx(struct request_queue
*q
)
44 return __blk_mq_get_ctx(q
, get_cpu());
47 static void blk_mq_put_ctx(struct blk_mq_ctx
*ctx
)
53 * Check if any of the ctx's have pending work in this hardware queue
55 static bool blk_mq_hctx_has_pending(struct blk_mq_hw_ctx
*hctx
)
59 for (i
= 0; i
< hctx
->ctx_map
.map_size
; i
++)
60 if (hctx
->ctx_map
.map
[i
].word
)
66 static inline struct blk_align_bitmap
*get_bm(struct blk_mq_hw_ctx
*hctx
,
67 struct blk_mq_ctx
*ctx
)
69 return &hctx
->ctx_map
.map
[ctx
->index_hw
/ hctx
->ctx_map
.bits_per_word
];
72 #define CTX_TO_BIT(hctx, ctx) \
73 ((ctx)->index_hw & ((hctx)->ctx_map.bits_per_word - 1))
76 * Mark this ctx as having pending work in this hardware queue
78 static void blk_mq_hctx_mark_pending(struct blk_mq_hw_ctx
*hctx
,
79 struct blk_mq_ctx
*ctx
)
81 struct blk_align_bitmap
*bm
= get_bm(hctx
, ctx
);
83 if (!test_bit(CTX_TO_BIT(hctx
, ctx
), &bm
->word
))
84 set_bit(CTX_TO_BIT(hctx
, ctx
), &bm
->word
);
87 static void blk_mq_hctx_clear_pending(struct blk_mq_hw_ctx
*hctx
,
88 struct blk_mq_ctx
*ctx
)
90 struct blk_align_bitmap
*bm
= get_bm(hctx
, ctx
);
92 clear_bit(CTX_TO_BIT(hctx
, ctx
), &bm
->word
);
95 static struct request
*__blk_mq_alloc_request(struct blk_mq_hw_ctx
*hctx
,
96 struct blk_mq_ctx
*ctx
,
97 gfp_t gfp
, bool reserved
)
102 tag
= blk_mq_get_tag(hctx
, &ctx
->last_tag
, gfp
, reserved
);
103 if (tag
!= BLK_MQ_TAG_FAIL
) {
104 rq
= hctx
->tags
->rqs
[tag
];
107 if (blk_mq_tag_busy(hctx
)) {
108 rq
->cmd_flags
= REQ_MQ_INFLIGHT
;
109 atomic_inc(&hctx
->nr_active
);
119 static int blk_mq_queue_enter(struct request_queue
*q
)
123 __percpu_counter_add(&q
->mq_usage_counter
, 1, 1000000);
125 /* we have problems to freeze the queue if it's initializing */
126 if (!blk_queue_bypass(q
) || !blk_queue_init_done(q
))
129 __percpu_counter_add(&q
->mq_usage_counter
, -1, 1000000);
131 spin_lock_irq(q
->queue_lock
);
132 ret
= wait_event_interruptible_lock_irq(q
->mq_freeze_wq
,
133 !blk_queue_bypass(q
) || blk_queue_dying(q
),
135 /* inc usage with lock hold to avoid freeze_queue runs here */
136 if (!ret
&& !blk_queue_dying(q
))
137 __percpu_counter_add(&q
->mq_usage_counter
, 1, 1000000);
138 else if (blk_queue_dying(q
))
140 spin_unlock_irq(q
->queue_lock
);
145 static void blk_mq_queue_exit(struct request_queue
*q
)
147 __percpu_counter_add(&q
->mq_usage_counter
, -1, 1000000);
150 static void __blk_mq_drain_queue(struct request_queue
*q
)
155 spin_lock_irq(q
->queue_lock
);
156 count
= percpu_counter_sum(&q
->mq_usage_counter
);
157 spin_unlock_irq(q
->queue_lock
);
161 blk_mq_run_queues(q
, false);
167 * Guarantee no request is in use, so we can change any data structure of
168 * the queue afterward.
170 static void blk_mq_freeze_queue(struct request_queue
*q
)
174 spin_lock_irq(q
->queue_lock
);
175 drain
= !q
->bypass_depth
++;
176 queue_flag_set(QUEUE_FLAG_BYPASS
, q
);
177 spin_unlock_irq(q
->queue_lock
);
180 __blk_mq_drain_queue(q
);
183 void blk_mq_drain_queue(struct request_queue
*q
)
185 __blk_mq_drain_queue(q
);
188 static void blk_mq_unfreeze_queue(struct request_queue
*q
)
192 spin_lock_irq(q
->queue_lock
);
193 if (!--q
->bypass_depth
) {
194 queue_flag_clear(QUEUE_FLAG_BYPASS
, q
);
197 WARN_ON_ONCE(q
->bypass_depth
< 0);
198 spin_unlock_irq(q
->queue_lock
);
200 wake_up_all(&q
->mq_freeze_wq
);
203 bool blk_mq_can_queue(struct blk_mq_hw_ctx
*hctx
)
205 return blk_mq_has_free_tags(hctx
->tags
);
207 EXPORT_SYMBOL(blk_mq_can_queue
);
209 static void blk_mq_rq_ctx_init(struct request_queue
*q
, struct blk_mq_ctx
*ctx
,
210 struct request
*rq
, unsigned int rw_flags
)
212 if (blk_queue_io_stat(q
))
213 rw_flags
|= REQ_IO_STAT
;
215 INIT_LIST_HEAD(&rq
->queuelist
);
216 /* csd/requeue_work/fifo_time is initialized before use */
219 rq
->cmd_flags
|= rw_flags
;
221 /* do not touch atomic flags, it needs atomic ops against the timer */
224 rq
->__sector
= (sector_t
) -1;
227 INIT_HLIST_NODE(&rq
->hash
);
228 RB_CLEAR_NODE(&rq
->rb_node
);
229 memset(&rq
->flush
, 0, max(sizeof(rq
->flush
), sizeof(rq
->elv
)));
232 rq
->start_time
= jiffies
;
233 #ifdef CONFIG_BLK_CGROUP
235 set_start_time_ns(rq
);
236 rq
->io_start_time_ns
= 0;
238 rq
->nr_phys_segments
= 0;
239 #if defined(CONFIG_BLK_DEV_INTEGRITY)
240 rq
->nr_integrity_segments
= 0;
244 /* tag was already set */
246 memset(rq
->__cmd
, 0, sizeof(rq
->__cmd
));
248 rq
->cmd_len
= BLK_MAX_CDB
;
256 INIT_LIST_HEAD(&rq
->timeout_list
);
260 rq
->end_io_data
= NULL
;
263 ctx
->rq_dispatched
[rw_is_sync(rw_flags
)]++;
266 static struct request
*blk_mq_alloc_request_pinned(struct request_queue
*q
,
273 struct blk_mq_ctx
*ctx
= blk_mq_get_ctx(q
);
274 struct blk_mq_hw_ctx
*hctx
= q
->mq_ops
->map_queue(q
, ctx
->cpu
);
276 rq
= __blk_mq_alloc_request(hctx
, ctx
, gfp
& ~__GFP_WAIT
,
279 blk_mq_rq_ctx_init(q
, ctx
, rq
, rw
);
283 if (gfp
& __GFP_WAIT
) {
284 __blk_mq_run_hw_queue(hctx
);
291 blk_mq_wait_for_tags(hctx
, reserved
);
297 struct request
*blk_mq_alloc_request(struct request_queue
*q
, int rw
, gfp_t gfp
)
301 if (blk_mq_queue_enter(q
))
304 rq
= blk_mq_alloc_request_pinned(q
, rw
, gfp
, false);
306 blk_mq_put_ctx(rq
->mq_ctx
);
309 EXPORT_SYMBOL(blk_mq_alloc_request
);
311 struct request
*blk_mq_alloc_reserved_request(struct request_queue
*q
, int rw
,
316 if (blk_mq_queue_enter(q
))
319 rq
= blk_mq_alloc_request_pinned(q
, rw
, gfp
, true);
321 blk_mq_put_ctx(rq
->mq_ctx
);
324 EXPORT_SYMBOL(blk_mq_alloc_reserved_request
);
326 static void __blk_mq_free_request(struct blk_mq_hw_ctx
*hctx
,
327 struct blk_mq_ctx
*ctx
, struct request
*rq
)
329 const int tag
= rq
->tag
;
330 struct request_queue
*q
= rq
->q
;
332 if (rq
->cmd_flags
& REQ_MQ_INFLIGHT
)
333 atomic_dec(&hctx
->nr_active
);
335 clear_bit(REQ_ATOM_STARTED
, &rq
->atomic_flags
);
336 blk_mq_put_tag(hctx
, tag
, &ctx
->last_tag
);
337 blk_mq_queue_exit(q
);
340 void blk_mq_free_request(struct request
*rq
)
342 struct blk_mq_ctx
*ctx
= rq
->mq_ctx
;
343 struct blk_mq_hw_ctx
*hctx
;
344 struct request_queue
*q
= rq
->q
;
346 ctx
->rq_completed
[rq_is_sync(rq
)]++;
348 hctx
= q
->mq_ops
->map_queue(q
, ctx
->cpu
);
349 __blk_mq_free_request(hctx
, ctx
, rq
);
353 * Clone all relevant state from a request that has been put on hold in
354 * the flush state machine into the preallocated flush request that hangs
355 * off the request queue.
357 * For a driver the flush request should be invisible, that's why we are
358 * impersonating the original request here.
360 void blk_mq_clone_flush_request(struct request
*flush_rq
,
361 struct request
*orig_rq
)
363 struct blk_mq_hw_ctx
*hctx
=
364 orig_rq
->q
->mq_ops
->map_queue(orig_rq
->q
, orig_rq
->mq_ctx
->cpu
);
366 flush_rq
->mq_ctx
= orig_rq
->mq_ctx
;
367 flush_rq
->tag
= orig_rq
->tag
;
368 memcpy(blk_mq_rq_to_pdu(flush_rq
), blk_mq_rq_to_pdu(orig_rq
),
372 inline void __blk_mq_end_io(struct request
*rq
, int error
)
374 blk_account_io_done(rq
);
377 rq
->end_io(rq
, error
);
379 if (unlikely(blk_bidi_rq(rq
)))
380 blk_mq_free_request(rq
->next_rq
);
381 blk_mq_free_request(rq
);
384 EXPORT_SYMBOL(__blk_mq_end_io
);
386 void blk_mq_end_io(struct request
*rq
, int error
)
388 if (blk_update_request(rq
, error
, blk_rq_bytes(rq
)))
390 __blk_mq_end_io(rq
, error
);
392 EXPORT_SYMBOL(blk_mq_end_io
);
394 static void __blk_mq_complete_request_remote(void *data
)
396 struct request
*rq
= data
;
398 rq
->q
->softirq_done_fn(rq
);
401 void __blk_mq_complete_request(struct request
*rq
)
403 struct blk_mq_ctx
*ctx
= rq
->mq_ctx
;
407 if (!test_bit(QUEUE_FLAG_SAME_COMP
, &rq
->q
->queue_flags
)) {
408 rq
->q
->softirq_done_fn(rq
);
413 if (!test_bit(QUEUE_FLAG_SAME_FORCE
, &rq
->q
->queue_flags
))
414 shared
= cpus_share_cache(cpu
, ctx
->cpu
);
416 if (cpu
!= ctx
->cpu
&& !shared
&& cpu_online(ctx
->cpu
)) {
417 rq
->csd
.func
= __blk_mq_complete_request_remote
;
420 smp_call_function_single_async(ctx
->cpu
, &rq
->csd
);
422 rq
->q
->softirq_done_fn(rq
);
428 * blk_mq_complete_request - end I/O on a request
429 * @rq: the request being processed
432 * Ends all I/O on a request. It does not handle partial completions.
433 * The actual completion happens out-of-order, through a IPI handler.
435 void blk_mq_complete_request(struct request
*rq
)
437 if (unlikely(blk_should_fake_timeout(rq
->q
)))
439 if (!blk_mark_rq_complete(rq
))
440 __blk_mq_complete_request(rq
);
442 EXPORT_SYMBOL(blk_mq_complete_request
);
444 static void blk_mq_start_request(struct request
*rq
, bool last
)
446 struct request_queue
*q
= rq
->q
;
448 trace_block_rq_issue(q
, rq
);
450 rq
->resid_len
= blk_rq_bytes(rq
);
451 if (unlikely(blk_bidi_rq(rq
)))
452 rq
->next_rq
->resid_len
= blk_rq_bytes(rq
->next_rq
);
455 * Just mark start time and set the started bit. Due to memory
456 * ordering, we know we'll see the correct deadline as long as
457 * REQ_ATOMIC_STARTED is seen.
459 rq
->deadline
= jiffies
+ q
->rq_timeout
;
462 * Mark us as started and clear complete. Complete might have been
463 * set if requeue raced with timeout, which then marked it as
464 * complete. So be sure to clear complete again when we start
465 * the request, otherwise we'll ignore the completion event.
467 set_bit(REQ_ATOM_STARTED
, &rq
->atomic_flags
);
468 clear_bit(REQ_ATOM_COMPLETE
, &rq
->atomic_flags
);
470 if (q
->dma_drain_size
&& blk_rq_bytes(rq
)) {
472 * Make sure space for the drain appears. We know we can do
473 * this because max_hw_segments has been adjusted to be one
474 * fewer than the device can handle.
476 rq
->nr_phys_segments
++;
480 * Flag the last request in the series so that drivers know when IO
481 * should be kicked off, if they don't do it on a per-request basis.
483 * Note: the flag isn't the only condition drivers should do kick off.
484 * If drive is busy, the last request might not have the bit set.
487 rq
->cmd_flags
|= REQ_END
;
490 static void __blk_mq_requeue_request(struct request
*rq
)
492 struct request_queue
*q
= rq
->q
;
494 trace_block_rq_requeue(q
, rq
);
495 clear_bit(REQ_ATOM_STARTED
, &rq
->atomic_flags
);
497 rq
->cmd_flags
&= ~REQ_END
;
499 if (q
->dma_drain_size
&& blk_rq_bytes(rq
))
500 rq
->nr_phys_segments
--;
503 void blk_mq_requeue_request(struct request
*rq
)
505 __blk_mq_requeue_request(rq
);
506 blk_clear_rq_complete(rq
);
508 BUG_ON(blk_queued_rq(rq
));
509 blk_mq_insert_request(rq
, true, true, false);
511 EXPORT_SYMBOL(blk_mq_requeue_request
);
513 struct request
*blk_mq_tag_to_rq(struct blk_mq_tags
*tags
, unsigned int tag
)
515 return tags
->rqs
[tag
];
517 EXPORT_SYMBOL(blk_mq_tag_to_rq
);
519 struct blk_mq_timeout_data
{
520 struct blk_mq_hw_ctx
*hctx
;
522 unsigned int *next_set
;
525 static void blk_mq_timeout_check(void *__data
, unsigned long *free_tags
)
527 struct blk_mq_timeout_data
*data
= __data
;
528 struct blk_mq_hw_ctx
*hctx
= data
->hctx
;
531 /* It may not be in flight yet (this is where
532 * the REQ_ATOMIC_STARTED flag comes in). The requests are
533 * statically allocated, so we know it's always safe to access the
534 * memory associated with a bit offset into ->rqs[].
540 tag
= find_next_zero_bit(free_tags
, hctx
->tags
->nr_tags
, tag
);
541 if (tag
>= hctx
->tags
->nr_tags
)
544 rq
= blk_mq_tag_to_rq(hctx
->tags
, tag
++);
545 if (rq
->q
!= hctx
->queue
)
547 if (!test_bit(REQ_ATOM_STARTED
, &rq
->atomic_flags
))
550 blk_rq_check_expired(rq
, data
->next
, data
->next_set
);
554 static void blk_mq_hw_ctx_check_timeout(struct blk_mq_hw_ctx
*hctx
,
556 unsigned int *next_set
)
558 struct blk_mq_timeout_data data
= {
561 .next_set
= next_set
,
565 * Ask the tagging code to iterate busy requests, so we can
566 * check them for timeout.
568 blk_mq_tag_busy_iter(hctx
->tags
, blk_mq_timeout_check
, &data
);
571 static enum blk_eh_timer_return
blk_mq_rq_timed_out(struct request
*rq
)
573 struct request_queue
*q
= rq
->q
;
576 * We know that complete is set at this point. If STARTED isn't set
577 * anymore, then the request isn't active and the "timeout" should
578 * just be ignored. This can happen due to the bitflag ordering.
579 * Timeout first checks if STARTED is set, and if it is, assumes
580 * the request is active. But if we race with completion, then
581 * we both flags will get cleared. So check here again, and ignore
582 * a timeout event with a request that isn't active.
584 if (!test_bit(REQ_ATOM_STARTED
, &rq
->atomic_flags
))
585 return BLK_EH_NOT_HANDLED
;
587 if (!q
->mq_ops
->timeout
)
588 return BLK_EH_RESET_TIMER
;
590 return q
->mq_ops
->timeout(rq
);
593 static void blk_mq_rq_timer(unsigned long data
)
595 struct request_queue
*q
= (struct request_queue
*) data
;
596 struct blk_mq_hw_ctx
*hctx
;
597 unsigned long next
= 0;
600 queue_for_each_hw_ctx(q
, hctx
, i
)
601 blk_mq_hw_ctx_check_timeout(hctx
, &next
, &next_set
);
604 next
= blk_rq_timeout(round_jiffies_up(next
));
605 mod_timer(&q
->timeout
, next
);
607 queue_for_each_hw_ctx(q
, hctx
, i
)
608 blk_mq_tag_idle(hctx
);
613 * Reverse check our software queue for entries that we could potentially
614 * merge with. Currently includes a hand-wavy stop count of 8, to not spend
615 * too much time checking for merges.
617 static bool blk_mq_attempt_merge(struct request_queue
*q
,
618 struct blk_mq_ctx
*ctx
, struct bio
*bio
)
623 list_for_each_entry_reverse(rq
, &ctx
->rq_list
, queuelist
) {
629 if (!blk_rq_merge_ok(rq
, bio
))
632 el_ret
= blk_try_merge(rq
, bio
);
633 if (el_ret
== ELEVATOR_BACK_MERGE
) {
634 if (bio_attempt_back_merge(q
, rq
, bio
)) {
639 } else if (el_ret
== ELEVATOR_FRONT_MERGE
) {
640 if (bio_attempt_front_merge(q
, rq
, bio
)) {
652 * Process software queues that have been marked busy, splicing them
653 * to the for-dispatch
655 static void flush_busy_ctxs(struct blk_mq_hw_ctx
*hctx
, struct list_head
*list
)
657 struct blk_mq_ctx
*ctx
;
660 for (i
= 0; i
< hctx
->ctx_map
.map_size
; i
++) {
661 struct blk_align_bitmap
*bm
= &hctx
->ctx_map
.map
[i
];
662 unsigned int off
, bit
;
668 off
= i
* hctx
->ctx_map
.bits_per_word
;
670 bit
= find_next_bit(&bm
->word
, bm
->depth
, bit
);
671 if (bit
>= bm
->depth
)
674 ctx
= hctx
->ctxs
[bit
+ off
];
675 clear_bit(bit
, &bm
->word
);
676 spin_lock(&ctx
->lock
);
677 list_splice_tail_init(&ctx
->rq_list
, list
);
678 spin_unlock(&ctx
->lock
);
686 * Run this hardware queue, pulling any software queues mapped to it in.
687 * Note that this function currently has various problems around ordering
688 * of IO. In particular, we'd like FIFO behaviour on handling existing
689 * items on the hctx->dispatch list. Ignore that for now.
691 static void __blk_mq_run_hw_queue(struct blk_mq_hw_ctx
*hctx
)
693 struct request_queue
*q
= hctx
->queue
;
698 WARN_ON(!cpumask_test_cpu(raw_smp_processor_id(), hctx
->cpumask
));
700 if (unlikely(test_bit(BLK_MQ_S_STOPPED
, &hctx
->state
)))
706 * Touch any software queue that has pending entries.
708 flush_busy_ctxs(hctx
, &rq_list
);
711 * If we have previous entries on our dispatch list, grab them
712 * and stuff them at the front for more fair dispatch.
714 if (!list_empty_careful(&hctx
->dispatch
)) {
715 spin_lock(&hctx
->lock
);
716 if (!list_empty(&hctx
->dispatch
))
717 list_splice_init(&hctx
->dispatch
, &rq_list
);
718 spin_unlock(&hctx
->lock
);
722 * Now process all the entries, sending them to the driver.
725 while (!list_empty(&rq_list
)) {
728 rq
= list_first_entry(&rq_list
, struct request
, queuelist
);
729 list_del_init(&rq
->queuelist
);
731 blk_mq_start_request(rq
, list_empty(&rq_list
));
733 ret
= q
->mq_ops
->queue_rq(hctx
, rq
);
735 case BLK_MQ_RQ_QUEUE_OK
:
738 case BLK_MQ_RQ_QUEUE_BUSY
:
739 list_add(&rq
->queuelist
, &rq_list
);
740 __blk_mq_requeue_request(rq
);
743 pr_err("blk-mq: bad return on queue: %d\n", ret
);
744 case BLK_MQ_RQ_QUEUE_ERROR
:
746 blk_mq_end_io(rq
, rq
->errors
);
750 if (ret
== BLK_MQ_RQ_QUEUE_BUSY
)
755 hctx
->dispatched
[0]++;
756 else if (queued
< (1 << (BLK_MQ_MAX_DISPATCH_ORDER
- 1)))
757 hctx
->dispatched
[ilog2(queued
) + 1]++;
760 * Any items that need requeuing? Stuff them into hctx->dispatch,
761 * that is where we will continue on next queue run.
763 if (!list_empty(&rq_list
)) {
764 spin_lock(&hctx
->lock
);
765 list_splice(&rq_list
, &hctx
->dispatch
);
766 spin_unlock(&hctx
->lock
);
771 * It'd be great if the workqueue API had a way to pass
772 * in a mask and had some smarts for more clever placement.
773 * For now we just round-robin here, switching for every
774 * BLK_MQ_CPU_WORK_BATCH queued items.
776 static int blk_mq_hctx_next_cpu(struct blk_mq_hw_ctx
*hctx
)
778 int cpu
= hctx
->next_cpu
;
780 if (--hctx
->next_cpu_batch
<= 0) {
783 next_cpu
= cpumask_next(hctx
->next_cpu
, hctx
->cpumask
);
784 if (next_cpu
>= nr_cpu_ids
)
785 next_cpu
= cpumask_first(hctx
->cpumask
);
787 hctx
->next_cpu
= next_cpu
;
788 hctx
->next_cpu_batch
= BLK_MQ_CPU_WORK_BATCH
;
794 void blk_mq_run_hw_queue(struct blk_mq_hw_ctx
*hctx
, bool async
)
796 if (unlikely(test_bit(BLK_MQ_S_STOPPED
, &hctx
->state
)))
799 if (!async
&& cpumask_test_cpu(smp_processor_id(), hctx
->cpumask
))
800 __blk_mq_run_hw_queue(hctx
);
801 else if (hctx
->queue
->nr_hw_queues
== 1)
802 kblockd_schedule_delayed_work(&hctx
->run_work
, 0);
806 cpu
= blk_mq_hctx_next_cpu(hctx
);
807 kblockd_schedule_delayed_work_on(cpu
, &hctx
->run_work
, 0);
811 void blk_mq_run_queues(struct request_queue
*q
, bool async
)
813 struct blk_mq_hw_ctx
*hctx
;
816 queue_for_each_hw_ctx(q
, hctx
, i
) {
817 if ((!blk_mq_hctx_has_pending(hctx
) &&
818 list_empty_careful(&hctx
->dispatch
)) ||
819 test_bit(BLK_MQ_S_STOPPED
, &hctx
->state
))
823 blk_mq_run_hw_queue(hctx
, async
);
827 EXPORT_SYMBOL(blk_mq_run_queues
);
829 void blk_mq_stop_hw_queue(struct blk_mq_hw_ctx
*hctx
)
831 cancel_delayed_work(&hctx
->run_work
);
832 cancel_delayed_work(&hctx
->delay_work
);
833 set_bit(BLK_MQ_S_STOPPED
, &hctx
->state
);
835 EXPORT_SYMBOL(blk_mq_stop_hw_queue
);
837 void blk_mq_stop_hw_queues(struct request_queue
*q
)
839 struct blk_mq_hw_ctx
*hctx
;
842 queue_for_each_hw_ctx(q
, hctx
, i
)
843 blk_mq_stop_hw_queue(hctx
);
845 EXPORT_SYMBOL(blk_mq_stop_hw_queues
);
847 void blk_mq_start_hw_queue(struct blk_mq_hw_ctx
*hctx
)
849 clear_bit(BLK_MQ_S_STOPPED
, &hctx
->state
);
852 __blk_mq_run_hw_queue(hctx
);
855 EXPORT_SYMBOL(blk_mq_start_hw_queue
);
857 void blk_mq_start_hw_queues(struct request_queue
*q
)
859 struct blk_mq_hw_ctx
*hctx
;
862 queue_for_each_hw_ctx(q
, hctx
, i
)
863 blk_mq_start_hw_queue(hctx
);
865 EXPORT_SYMBOL(blk_mq_start_hw_queues
);
868 void blk_mq_start_stopped_hw_queues(struct request_queue
*q
, bool async
)
870 struct blk_mq_hw_ctx
*hctx
;
873 queue_for_each_hw_ctx(q
, hctx
, i
) {
874 if (!test_bit(BLK_MQ_S_STOPPED
, &hctx
->state
))
877 clear_bit(BLK_MQ_S_STOPPED
, &hctx
->state
);
879 blk_mq_run_hw_queue(hctx
, async
);
883 EXPORT_SYMBOL(blk_mq_start_stopped_hw_queues
);
885 static void blk_mq_run_work_fn(struct work_struct
*work
)
887 struct blk_mq_hw_ctx
*hctx
;
889 hctx
= container_of(work
, struct blk_mq_hw_ctx
, run_work
.work
);
891 __blk_mq_run_hw_queue(hctx
);
894 static void blk_mq_delay_work_fn(struct work_struct
*work
)
896 struct blk_mq_hw_ctx
*hctx
;
898 hctx
= container_of(work
, struct blk_mq_hw_ctx
, delay_work
.work
);
900 if (test_and_clear_bit(BLK_MQ_S_STOPPED
, &hctx
->state
))
901 __blk_mq_run_hw_queue(hctx
);
904 void blk_mq_delay_queue(struct blk_mq_hw_ctx
*hctx
, unsigned long msecs
)
906 unsigned long tmo
= msecs_to_jiffies(msecs
);
908 if (hctx
->queue
->nr_hw_queues
== 1)
909 kblockd_schedule_delayed_work(&hctx
->delay_work
, tmo
);
913 cpu
= blk_mq_hctx_next_cpu(hctx
);
914 kblockd_schedule_delayed_work_on(cpu
, &hctx
->delay_work
, tmo
);
917 EXPORT_SYMBOL(blk_mq_delay_queue
);
919 static void __blk_mq_insert_request(struct blk_mq_hw_ctx
*hctx
,
920 struct request
*rq
, bool at_head
)
922 struct blk_mq_ctx
*ctx
= rq
->mq_ctx
;
924 trace_block_rq_insert(hctx
->queue
, rq
);
927 list_add(&rq
->queuelist
, &ctx
->rq_list
);
929 list_add_tail(&rq
->queuelist
, &ctx
->rq_list
);
931 blk_mq_hctx_mark_pending(hctx
, ctx
);
934 * We do this early, to ensure we are on the right CPU.
939 void blk_mq_insert_request(struct request
*rq
, bool at_head
, bool run_queue
,
942 struct request_queue
*q
= rq
->q
;
943 struct blk_mq_hw_ctx
*hctx
;
944 struct blk_mq_ctx
*ctx
= rq
->mq_ctx
, *current_ctx
;
946 current_ctx
= blk_mq_get_ctx(q
);
947 if (!cpu_online(ctx
->cpu
))
948 rq
->mq_ctx
= ctx
= current_ctx
;
950 hctx
= q
->mq_ops
->map_queue(q
, ctx
->cpu
);
952 if (rq
->cmd_flags
& (REQ_FLUSH
| REQ_FUA
) &&
953 !(rq
->cmd_flags
& (REQ_FLUSH_SEQ
))) {
954 blk_insert_flush(rq
);
956 spin_lock(&ctx
->lock
);
957 __blk_mq_insert_request(hctx
, rq
, at_head
);
958 spin_unlock(&ctx
->lock
);
962 blk_mq_run_hw_queue(hctx
, async
);
964 blk_mq_put_ctx(current_ctx
);
967 static void blk_mq_insert_requests(struct request_queue
*q
,
968 struct blk_mq_ctx
*ctx
,
969 struct list_head
*list
,
974 struct blk_mq_hw_ctx
*hctx
;
975 struct blk_mq_ctx
*current_ctx
;
977 trace_block_unplug(q
, depth
, !from_schedule
);
979 current_ctx
= blk_mq_get_ctx(q
);
981 if (!cpu_online(ctx
->cpu
))
983 hctx
= q
->mq_ops
->map_queue(q
, ctx
->cpu
);
986 * preemption doesn't flush plug list, so it's possible ctx->cpu is
989 spin_lock(&ctx
->lock
);
990 while (!list_empty(list
)) {
993 rq
= list_first_entry(list
, struct request
, queuelist
);
994 list_del_init(&rq
->queuelist
);
996 __blk_mq_insert_request(hctx
, rq
, false);
998 spin_unlock(&ctx
->lock
);
1000 blk_mq_run_hw_queue(hctx
, from_schedule
);
1001 blk_mq_put_ctx(current_ctx
);
1004 static int plug_ctx_cmp(void *priv
, struct list_head
*a
, struct list_head
*b
)
1006 struct request
*rqa
= container_of(a
, struct request
, queuelist
);
1007 struct request
*rqb
= container_of(b
, struct request
, queuelist
);
1009 return !(rqa
->mq_ctx
< rqb
->mq_ctx
||
1010 (rqa
->mq_ctx
== rqb
->mq_ctx
&&
1011 blk_rq_pos(rqa
) < blk_rq_pos(rqb
)));
1014 void blk_mq_flush_plug_list(struct blk_plug
*plug
, bool from_schedule
)
1016 struct blk_mq_ctx
*this_ctx
;
1017 struct request_queue
*this_q
;
1020 LIST_HEAD(ctx_list
);
1023 list_splice_init(&plug
->mq_list
, &list
);
1025 list_sort(NULL
, &list
, plug_ctx_cmp
);
1031 while (!list_empty(&list
)) {
1032 rq
= list_entry_rq(list
.next
);
1033 list_del_init(&rq
->queuelist
);
1035 if (rq
->mq_ctx
!= this_ctx
) {
1037 blk_mq_insert_requests(this_q
, this_ctx
,
1042 this_ctx
= rq
->mq_ctx
;
1048 list_add_tail(&rq
->queuelist
, &ctx_list
);
1052 * If 'this_ctx' is set, we know we have entries to complete
1053 * on 'ctx_list'. Do those.
1056 blk_mq_insert_requests(this_q
, this_ctx
, &ctx_list
, depth
,
1061 static void blk_mq_bio_to_request(struct request
*rq
, struct bio
*bio
)
1063 init_request_from_bio(rq
, bio
);
1064 blk_account_io_start(rq
, 1);
1067 static void blk_mq_make_request(struct request_queue
*q
, struct bio
*bio
)
1069 struct blk_mq_hw_ctx
*hctx
;
1070 struct blk_mq_ctx
*ctx
;
1071 const int is_sync
= rw_is_sync(bio
->bi_rw
);
1072 const int is_flush_fua
= bio
->bi_rw
& (REQ_FLUSH
| REQ_FUA
);
1073 int rw
= bio_data_dir(bio
);
1075 unsigned int use_plug
, request_count
= 0;
1078 * If we have multiple hardware queues, just go directly to
1079 * one of those for sync IO.
1081 use_plug
= !is_flush_fua
&& ((q
->nr_hw_queues
== 1) || !is_sync
);
1083 blk_queue_bounce(q
, &bio
);
1085 if (bio_integrity_enabled(bio
) && bio_integrity_prep(bio
)) {
1086 bio_endio(bio
, -EIO
);
1090 if (use_plug
&& !blk_queue_nomerges(q
) &&
1091 blk_attempt_plug_merge(q
, bio
, &request_count
))
1094 if (blk_mq_queue_enter(q
)) {
1095 bio_endio(bio
, -EIO
);
1099 ctx
= blk_mq_get_ctx(q
);
1100 hctx
= q
->mq_ops
->map_queue(q
, ctx
->cpu
);
1104 trace_block_getrq(q
, bio
, rw
);
1105 rq
= __blk_mq_alloc_request(hctx
, ctx
, GFP_ATOMIC
, false);
1107 blk_mq_rq_ctx_init(q
, ctx
, rq
, rw
);
1109 blk_mq_put_ctx(ctx
);
1110 trace_block_sleeprq(q
, bio
, rw
);
1111 rq
= blk_mq_alloc_request_pinned(q
, rw
, __GFP_WAIT
|GFP_ATOMIC
,
1114 hctx
= q
->mq_ops
->map_queue(q
, ctx
->cpu
);
1119 if (unlikely(is_flush_fua
)) {
1120 blk_mq_bio_to_request(rq
, bio
);
1121 blk_insert_flush(rq
);
1126 * A task plug currently exists. Since this is completely lockless,
1127 * utilize that to temporarily store requests until the task is
1128 * either done or scheduled away.
1131 struct blk_plug
*plug
= current
->plug
;
1134 blk_mq_bio_to_request(rq
, bio
);
1135 if (list_empty(&plug
->mq_list
))
1136 trace_block_plug(q
);
1137 else if (request_count
>= BLK_MAX_REQUEST_COUNT
) {
1138 blk_flush_plug_list(plug
, false);
1139 trace_block_plug(q
);
1141 list_add_tail(&rq
->queuelist
, &plug
->mq_list
);
1142 blk_mq_put_ctx(ctx
);
1147 if (!(hctx
->flags
& BLK_MQ_F_SHOULD_MERGE
)) {
1148 blk_mq_bio_to_request(rq
, bio
);
1149 spin_lock(&ctx
->lock
);
1151 __blk_mq_insert_request(hctx
, rq
, false);
1152 spin_unlock(&ctx
->lock
);
1154 spin_lock(&ctx
->lock
);
1155 if (!blk_mq_attempt_merge(q
, ctx
, bio
)) {
1156 blk_mq_bio_to_request(rq
, bio
);
1160 spin_unlock(&ctx
->lock
);
1161 __blk_mq_free_request(hctx
, ctx
, rq
);
1166 * For a SYNC request, send it to the hardware immediately. For an
1167 * ASYNC request, just ensure that we run it later on. The latter
1168 * allows for merging opportunities and more efficient dispatching.
1171 blk_mq_run_hw_queue(hctx
, !is_sync
|| is_flush_fua
);
1172 blk_mq_put_ctx(ctx
);
1176 * Default mapping to a software queue, since we use one per CPU.
1178 struct blk_mq_hw_ctx
*blk_mq_map_queue(struct request_queue
*q
, const int cpu
)
1180 return q
->queue_hw_ctx
[q
->mq_map
[cpu
]];
1182 EXPORT_SYMBOL(blk_mq_map_queue
);
1184 struct blk_mq_hw_ctx
*blk_mq_alloc_single_hw_queue(struct blk_mq_tag_set
*set
,
1185 unsigned int hctx_index
)
1187 return kzalloc_node(sizeof(struct blk_mq_hw_ctx
), GFP_KERNEL
,
1190 EXPORT_SYMBOL(blk_mq_alloc_single_hw_queue
);
1192 void blk_mq_free_single_hw_queue(struct blk_mq_hw_ctx
*hctx
,
1193 unsigned int hctx_index
)
1197 EXPORT_SYMBOL(blk_mq_free_single_hw_queue
);
1199 static void blk_mq_hctx_notify(void *data
, unsigned long action
,
1202 struct blk_mq_hw_ctx
*hctx
= data
;
1203 struct request_queue
*q
= hctx
->queue
;
1204 struct blk_mq_ctx
*ctx
;
1207 if (action
!= CPU_DEAD
&& action
!= CPU_DEAD_FROZEN
)
1211 * Move ctx entries to new CPU, if this one is going away.
1213 ctx
= __blk_mq_get_ctx(q
, cpu
);
1215 spin_lock(&ctx
->lock
);
1216 if (!list_empty(&ctx
->rq_list
)) {
1217 list_splice_init(&ctx
->rq_list
, &tmp
);
1218 blk_mq_hctx_clear_pending(hctx
, ctx
);
1220 spin_unlock(&ctx
->lock
);
1222 if (list_empty(&tmp
))
1225 ctx
= blk_mq_get_ctx(q
);
1226 spin_lock(&ctx
->lock
);
1228 while (!list_empty(&tmp
)) {
1231 rq
= list_first_entry(&tmp
, struct request
, queuelist
);
1233 list_move_tail(&rq
->queuelist
, &ctx
->rq_list
);
1236 hctx
= q
->mq_ops
->map_queue(q
, ctx
->cpu
);
1237 blk_mq_hctx_mark_pending(hctx
, ctx
);
1239 spin_unlock(&ctx
->lock
);
1241 blk_mq_run_hw_queue(hctx
, true);
1242 blk_mq_put_ctx(ctx
);
1245 static void blk_mq_free_rq_map(struct blk_mq_tag_set
*set
,
1246 struct blk_mq_tags
*tags
, unsigned int hctx_idx
)
1250 if (tags
->rqs
&& set
->ops
->exit_request
) {
1253 for (i
= 0; i
< tags
->nr_tags
; i
++) {
1256 set
->ops
->exit_request(set
->driver_data
, tags
->rqs
[i
],
1261 while (!list_empty(&tags
->page_list
)) {
1262 page
= list_first_entry(&tags
->page_list
, struct page
, lru
);
1263 list_del_init(&page
->lru
);
1264 __free_pages(page
, page
->private);
1269 blk_mq_free_tags(tags
);
1272 static size_t order_to_size(unsigned int order
)
1274 return (size_t)PAGE_SIZE
<< order
;
1277 static struct blk_mq_tags
*blk_mq_init_rq_map(struct blk_mq_tag_set
*set
,
1278 unsigned int hctx_idx
)
1280 struct blk_mq_tags
*tags
;
1281 unsigned int i
, j
, entries_per_page
, max_order
= 4;
1282 size_t rq_size
, left
;
1284 tags
= blk_mq_init_tags(set
->queue_depth
, set
->reserved_tags
,
1289 INIT_LIST_HEAD(&tags
->page_list
);
1291 tags
->rqs
= kmalloc_node(set
->queue_depth
* sizeof(struct request
*),
1292 GFP_KERNEL
, set
->numa_node
);
1294 blk_mq_free_tags(tags
);
1299 * rq_size is the size of the request plus driver payload, rounded
1300 * to the cacheline size
1302 rq_size
= round_up(sizeof(struct request
) + set
->cmd_size
,
1304 left
= rq_size
* set
->queue_depth
;
1306 for (i
= 0; i
< set
->queue_depth
; ) {
1307 int this_order
= max_order
;
1312 while (left
< order_to_size(this_order
- 1) && this_order
)
1316 page
= alloc_pages_node(set
->numa_node
, GFP_KERNEL
,
1322 if (order_to_size(this_order
) < rq_size
)
1329 page
->private = this_order
;
1330 list_add_tail(&page
->lru
, &tags
->page_list
);
1332 p
= page_address(page
);
1333 entries_per_page
= order_to_size(this_order
) / rq_size
;
1334 to_do
= min(entries_per_page
, set
->queue_depth
- i
);
1335 left
-= to_do
* rq_size
;
1336 for (j
= 0; j
< to_do
; j
++) {
1338 if (set
->ops
->init_request
) {
1339 if (set
->ops
->init_request(set
->driver_data
,
1340 tags
->rqs
[i
], hctx_idx
, i
,
1353 pr_warn("%s: failed to allocate requests\n", __func__
);
1354 blk_mq_free_rq_map(set
, tags
, hctx_idx
);
1358 static void blk_mq_free_bitmap(struct blk_mq_ctxmap
*bitmap
)
1363 static int blk_mq_alloc_bitmap(struct blk_mq_ctxmap
*bitmap
, int node
)
1365 unsigned int bpw
= 8, total
, num_maps
, i
;
1367 bitmap
->bits_per_word
= bpw
;
1369 num_maps
= ALIGN(nr_cpu_ids
, bpw
) / bpw
;
1370 bitmap
->map
= kzalloc_node(num_maps
* sizeof(struct blk_align_bitmap
),
1375 bitmap
->map_size
= num_maps
;
1378 for (i
= 0; i
< num_maps
; i
++) {
1379 bitmap
->map
[i
].depth
= min(total
, bitmap
->bits_per_word
);
1380 total
-= bitmap
->map
[i
].depth
;
1386 static int blk_mq_init_hw_queues(struct request_queue
*q
,
1387 struct blk_mq_tag_set
*set
)
1389 struct blk_mq_hw_ctx
*hctx
;
1393 * Initialize hardware queues
1395 queue_for_each_hw_ctx(q
, hctx
, i
) {
1398 node
= hctx
->numa_node
;
1399 if (node
== NUMA_NO_NODE
)
1400 node
= hctx
->numa_node
= set
->numa_node
;
1402 INIT_DELAYED_WORK(&hctx
->run_work
, blk_mq_run_work_fn
);
1403 INIT_DELAYED_WORK(&hctx
->delay_work
, blk_mq_delay_work_fn
);
1404 spin_lock_init(&hctx
->lock
);
1405 INIT_LIST_HEAD(&hctx
->dispatch
);
1407 hctx
->queue_num
= i
;
1408 hctx
->flags
= set
->flags
;
1409 hctx
->cmd_size
= set
->cmd_size
;
1411 blk_mq_init_cpu_notifier(&hctx
->cpu_notifier
,
1412 blk_mq_hctx_notify
, hctx
);
1413 blk_mq_register_cpu_notifier(&hctx
->cpu_notifier
);
1415 hctx
->tags
= set
->tags
[i
];
1418 * Allocate space for all possible cpus to avoid allocation in
1421 hctx
->ctxs
= kmalloc_node(nr_cpu_ids
* sizeof(void *),
1426 if (blk_mq_alloc_bitmap(&hctx
->ctx_map
, node
))
1431 if (set
->ops
->init_hctx
&&
1432 set
->ops
->init_hctx(hctx
, set
->driver_data
, i
))
1436 if (i
== q
->nr_hw_queues
)
1442 queue_for_each_hw_ctx(q
, hctx
, j
) {
1446 if (set
->ops
->exit_hctx
)
1447 set
->ops
->exit_hctx(hctx
, j
);
1449 blk_mq_unregister_cpu_notifier(&hctx
->cpu_notifier
);
1451 blk_mq_free_bitmap(&hctx
->ctx_map
);
1457 static void blk_mq_init_cpu_queues(struct request_queue
*q
,
1458 unsigned int nr_hw_queues
)
1462 for_each_possible_cpu(i
) {
1463 struct blk_mq_ctx
*__ctx
= per_cpu_ptr(q
->queue_ctx
, i
);
1464 struct blk_mq_hw_ctx
*hctx
;
1466 memset(__ctx
, 0, sizeof(*__ctx
));
1468 spin_lock_init(&__ctx
->lock
);
1469 INIT_LIST_HEAD(&__ctx
->rq_list
);
1472 /* If the cpu isn't online, the cpu is mapped to first hctx */
1476 hctx
= q
->mq_ops
->map_queue(q
, i
);
1477 cpumask_set_cpu(i
, hctx
->cpumask
);
1481 * Set local node, IFF we have more than one hw queue. If
1482 * not, we remain on the home node of the device
1484 if (nr_hw_queues
> 1 && hctx
->numa_node
== NUMA_NO_NODE
)
1485 hctx
->numa_node
= cpu_to_node(i
);
1489 static void blk_mq_map_swqueue(struct request_queue
*q
)
1492 struct blk_mq_hw_ctx
*hctx
;
1493 struct blk_mq_ctx
*ctx
;
1495 queue_for_each_hw_ctx(q
, hctx
, i
) {
1496 cpumask_clear(hctx
->cpumask
);
1501 * Map software to hardware queues
1503 queue_for_each_ctx(q
, ctx
, i
) {
1504 /* If the cpu isn't online, the cpu is mapped to first hctx */
1508 hctx
= q
->mq_ops
->map_queue(q
, i
);
1509 cpumask_set_cpu(i
, hctx
->cpumask
);
1510 ctx
->index_hw
= hctx
->nr_ctx
;
1511 hctx
->ctxs
[hctx
->nr_ctx
++] = ctx
;
1514 queue_for_each_hw_ctx(q
, hctx
, i
) {
1515 hctx
->next_cpu
= cpumask_first(hctx
->cpumask
);
1516 hctx
->next_cpu_batch
= BLK_MQ_CPU_WORK_BATCH
;
1520 static void blk_mq_update_tag_set_depth(struct blk_mq_tag_set
*set
)
1522 struct blk_mq_hw_ctx
*hctx
;
1523 struct request_queue
*q
;
1527 if (set
->tag_list
.next
== set
->tag_list
.prev
)
1532 list_for_each_entry(q
, &set
->tag_list
, tag_set_list
) {
1533 blk_mq_freeze_queue(q
);
1535 queue_for_each_hw_ctx(q
, hctx
, i
) {
1537 hctx
->flags
|= BLK_MQ_F_TAG_SHARED
;
1539 hctx
->flags
&= ~BLK_MQ_F_TAG_SHARED
;
1541 blk_mq_unfreeze_queue(q
);
1545 static void blk_mq_del_queue_tag_set(struct request_queue
*q
)
1547 struct blk_mq_tag_set
*set
= q
->tag_set
;
1549 blk_mq_freeze_queue(q
);
1551 mutex_lock(&set
->tag_list_lock
);
1552 list_del_init(&q
->tag_set_list
);
1553 blk_mq_update_tag_set_depth(set
);
1554 mutex_unlock(&set
->tag_list_lock
);
1556 blk_mq_unfreeze_queue(q
);
1559 static void blk_mq_add_queue_tag_set(struct blk_mq_tag_set
*set
,
1560 struct request_queue
*q
)
1564 mutex_lock(&set
->tag_list_lock
);
1565 list_add_tail(&q
->tag_set_list
, &set
->tag_list
);
1566 blk_mq_update_tag_set_depth(set
);
1567 mutex_unlock(&set
->tag_list_lock
);
1570 struct request_queue
*blk_mq_init_queue(struct blk_mq_tag_set
*set
)
1572 struct blk_mq_hw_ctx
**hctxs
;
1573 struct blk_mq_ctx
*ctx
;
1574 struct request_queue
*q
;
1577 ctx
= alloc_percpu(struct blk_mq_ctx
);
1579 return ERR_PTR(-ENOMEM
);
1581 hctxs
= kmalloc_node(set
->nr_hw_queues
* sizeof(*hctxs
), GFP_KERNEL
,
1587 for (i
= 0; i
< set
->nr_hw_queues
; i
++) {
1588 hctxs
[i
] = set
->ops
->alloc_hctx(set
, i
);
1592 if (!zalloc_cpumask_var(&hctxs
[i
]->cpumask
, GFP_KERNEL
))
1595 atomic_set(&hctxs
[i
]->nr_active
, 0);
1596 hctxs
[i
]->numa_node
= NUMA_NO_NODE
;
1597 hctxs
[i
]->queue_num
= i
;
1600 q
= blk_alloc_queue_node(GFP_KERNEL
, set
->numa_node
);
1604 q
->mq_map
= blk_mq_make_queue_map(set
);
1608 setup_timer(&q
->timeout
, blk_mq_rq_timer
, (unsigned long) q
);
1609 blk_queue_rq_timeout(q
, 30000);
1611 q
->nr_queues
= nr_cpu_ids
;
1612 q
->nr_hw_queues
= set
->nr_hw_queues
;
1615 q
->queue_hw_ctx
= hctxs
;
1617 q
->mq_ops
= set
->ops
;
1618 q
->queue_flags
|= QUEUE_FLAG_MQ_DEFAULT
;
1620 q
->sg_reserved_size
= INT_MAX
;
1622 blk_queue_make_request(q
, blk_mq_make_request
);
1623 blk_queue_rq_timed_out(q
, blk_mq_rq_timed_out
);
1625 blk_queue_rq_timeout(q
, set
->timeout
);
1628 * Do this after blk_queue_make_request() overrides it...
1630 q
->nr_requests
= set
->queue_depth
;
1632 if (set
->ops
->complete
)
1633 blk_queue_softirq_done(q
, set
->ops
->complete
);
1635 blk_mq_init_flush(q
);
1636 blk_mq_init_cpu_queues(q
, set
->nr_hw_queues
);
1638 q
->flush_rq
= kzalloc(round_up(sizeof(struct request
) +
1639 set
->cmd_size
, cache_line_size()),
1644 if (blk_mq_init_hw_queues(q
, set
))
1647 blk_mq_map_swqueue(q
);
1649 mutex_lock(&all_q_mutex
);
1650 list_add_tail(&q
->all_q_node
, &all_q_list
);
1651 mutex_unlock(&all_q_mutex
);
1653 blk_mq_add_queue_tag_set(set
, q
);
1662 blk_cleanup_queue(q
);
1664 for (i
= 0; i
< set
->nr_hw_queues
; i
++) {
1667 free_cpumask_var(hctxs
[i
]->cpumask
);
1668 set
->ops
->free_hctx(hctxs
[i
], i
);
1673 return ERR_PTR(-ENOMEM
);
1675 EXPORT_SYMBOL(blk_mq_init_queue
);
1677 void blk_mq_free_queue(struct request_queue
*q
)
1679 struct blk_mq_hw_ctx
*hctx
;
1682 blk_mq_del_queue_tag_set(q
);
1684 queue_for_each_hw_ctx(q
, hctx
, i
) {
1686 blk_mq_unregister_cpu_notifier(&hctx
->cpu_notifier
);
1687 if (q
->mq_ops
->exit_hctx
)
1688 q
->mq_ops
->exit_hctx(hctx
, i
);
1689 free_cpumask_var(hctx
->cpumask
);
1690 q
->mq_ops
->free_hctx(hctx
, i
);
1693 free_percpu(q
->queue_ctx
);
1694 kfree(q
->queue_hw_ctx
);
1697 q
->queue_ctx
= NULL
;
1698 q
->queue_hw_ctx
= NULL
;
1701 mutex_lock(&all_q_mutex
);
1702 list_del_init(&q
->all_q_node
);
1703 mutex_unlock(&all_q_mutex
);
1706 /* Basically redo blk_mq_init_queue with queue frozen */
1707 static void blk_mq_queue_reinit(struct request_queue
*q
)
1709 blk_mq_freeze_queue(q
);
1711 blk_mq_update_queue_map(q
->mq_map
, q
->nr_hw_queues
);
1714 * redo blk_mq_init_cpu_queues and blk_mq_init_hw_queues. FIXME: maybe
1715 * we should change hctx numa_node according to new topology (this
1716 * involves free and re-allocate memory, worthy doing?)
1719 blk_mq_map_swqueue(q
);
1721 blk_mq_unfreeze_queue(q
);
1724 static int blk_mq_queue_reinit_notify(struct notifier_block
*nb
,
1725 unsigned long action
, void *hcpu
)
1727 struct request_queue
*q
;
1730 * Before new mappings are established, hotadded cpu might already
1731 * start handling requests. This doesn't break anything as we map
1732 * offline CPUs to first hardware queue. We will re-init the queue
1733 * below to get optimal settings.
1735 if (action
!= CPU_DEAD
&& action
!= CPU_DEAD_FROZEN
&&
1736 action
!= CPU_ONLINE
&& action
!= CPU_ONLINE_FROZEN
)
1739 mutex_lock(&all_q_mutex
);
1740 list_for_each_entry(q
, &all_q_list
, all_q_node
)
1741 blk_mq_queue_reinit(q
);
1742 mutex_unlock(&all_q_mutex
);
1746 int blk_mq_alloc_tag_set(struct blk_mq_tag_set
*set
)
1750 if (!set
->nr_hw_queues
)
1752 if (!set
->queue_depth
|| set
->queue_depth
> BLK_MQ_MAX_DEPTH
)
1754 if (set
->queue_depth
< set
->reserved_tags
+ BLK_MQ_TAG_MIN
)
1757 if (!set
->nr_hw_queues
||
1758 !set
->ops
->queue_rq
|| !set
->ops
->map_queue
||
1759 !set
->ops
->alloc_hctx
|| !set
->ops
->free_hctx
)
1763 set
->tags
= kmalloc_node(set
->nr_hw_queues
*
1764 sizeof(struct blk_mq_tags
*),
1765 GFP_KERNEL
, set
->numa_node
);
1769 for (i
= 0; i
< set
->nr_hw_queues
; i
++) {
1770 set
->tags
[i
] = blk_mq_init_rq_map(set
, i
);
1775 mutex_init(&set
->tag_list_lock
);
1776 INIT_LIST_HEAD(&set
->tag_list
);
1782 blk_mq_free_rq_map(set
, set
->tags
[i
], i
);
1786 EXPORT_SYMBOL(blk_mq_alloc_tag_set
);
1788 void blk_mq_free_tag_set(struct blk_mq_tag_set
*set
)
1792 for (i
= 0; i
< set
->nr_hw_queues
; i
++)
1793 blk_mq_free_rq_map(set
, set
->tags
[i
], i
);
1796 EXPORT_SYMBOL(blk_mq_free_tag_set
);
1798 int blk_mq_update_nr_requests(struct request_queue
*q
, unsigned int nr
)
1800 struct blk_mq_tag_set
*set
= q
->tag_set
;
1801 struct blk_mq_hw_ctx
*hctx
;
1804 if (!set
|| nr
> set
->queue_depth
)
1808 queue_for_each_hw_ctx(q
, hctx
, i
) {
1809 ret
= blk_mq_tag_update_depth(hctx
->tags
, nr
);
1815 q
->nr_requests
= nr
;
1820 void blk_mq_disable_hotplug(void)
1822 mutex_lock(&all_q_mutex
);
1825 void blk_mq_enable_hotplug(void)
1827 mutex_unlock(&all_q_mutex
);
1830 static int __init
blk_mq_init(void)
1834 /* Must be called after percpu_counter_hotcpu_callback() */
1835 hotcpu_notifier(blk_mq_queue_reinit_notify
, -10);
1839 subsys_initcall(blk_mq_init
);