blk-mq: Restart a single queue if tag sets are shared

To improve scalability, if hardware queues are shared, restart
a single hardware queue in round-robin fashion. Rename
blk_mq_sched_restart_queues() to reflect the new semantics.
Remove blk_mq_sched_mark_restart_queue() because this function
has no callers. Remove flag QUEUE_FLAG_RESTART because this
patch removes the code that uses this flag.

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Hannes Reinecke <hare@suse.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
This commit is contained in:
Bart Van Assche 2017-04-07 12:40:09 -06:00 committed by Jens Axboe
parent 6077c2d706
commit 6d8c6c0f97
4 changed files with 55 additions and 27 deletions

View file

@ -19,7 +19,7 @@ bool blk_mq_sched_try_merge(struct request_queue *q, struct bio *bio,
struct request **merged_request);
bool __blk_mq_sched_bio_merge(struct request_queue *q, struct bio *bio);
bool blk_mq_sched_try_insert_merge(struct request_queue *q, struct request *rq);
void blk_mq_sched_restart_queues(struct blk_mq_hw_ctx *hctx);
void blk_mq_sched_restart(struct blk_mq_hw_ctx *hctx);
void blk_mq_sched_insert_request(struct request *rq, bool at_head,
bool run_queue, bool async, bool can_block);
@ -136,20 +136,6 @@ static inline void blk_mq_sched_mark_restart_hctx(struct blk_mq_hw_ctx *hctx)
set_bit(BLK_MQ_S_SCHED_RESTART, &hctx->state);
}
/*
* Mark a hardware queue and the request queue it belongs to as needing a
* restart.
*/
static inline void blk_mq_sched_mark_restart_queue(struct blk_mq_hw_ctx *hctx)
{
struct request_queue *q = hctx->queue;
if (!test_bit(BLK_MQ_S_SCHED_RESTART, &hctx->state))
set_bit(BLK_MQ_S_SCHED_RESTART, &hctx->state);
if (!test_bit(QUEUE_FLAG_RESTART, &q->queue_flags))
set_bit(QUEUE_FLAG_RESTART, &q->queue_flags);
}
static inline bool blk_mq_sched_needs_restart(struct blk_mq_hw_ctx *hctx)
{
return test_bit(BLK_MQ_S_SCHED_RESTART, &hctx->state);