Commit 536167d4 authored by Keith Busch's avatar Keith Busch Committed by Jens Axboe
Browse files

blk-mq: don't commit_rqs() if none were queued 



Unburden the drivers from checking if a call to commit_rqs() is valid by
not calling it when there are no requests to commit.

Signed-off-by: default avatarKeith Busch <kbusch@kernel.org>
Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent c52abf56

block/blk-mq.c

+6 −3
Original line number Diff line number Diff line
@@ -1289,7 +1289,7 @@ bool blk_mq_dispatch_rq_list(struct request_queue *q, struct list_head *list, 
		 * the driver there was more coming, but that turned out to

		 * be a lie.

		 */

		if (q->mq_ops->commit_rqs)

		if (q->mq_ops->commit_rqs && queued)

			q->mq_ops->commit_rqs(hctx);



		spin_lock(&hctx->lock);
@@ -1911,6 +1911,8 @@ blk_status_t blk_mq_request_issue_directly(struct request *rq, bool last) 
void blk_mq_try_issue_list_directly(struct blk_mq_hw_ctx *hctx,

		struct list_head *list)

{

	int queued = 0;



	while (!list_empty(list)) {

		blk_status_t ret;

		struct request *rq = list_first_entry(list, struct request,
@@ -1926,7 +1928,8 @@ void blk_mq_try_issue_list_directly(struct blk_mq_hw_ctx *hctx, 
				break;

			}

			blk_mq_end_request(rq, ret);

		}

		} else

			queued++;

	}



	/*
@@ -1934,7 +1937,7 @@ void blk_mq_try_issue_list_directly(struct blk_mq_hw_ctx *hctx, 
	 * the driver there was more coming, but that turned out to

	 * be a lie.

	 */

	if (!list_empty(list) && hctx->queue->mq_ops->commit_rqs)

	if (!list_empty(list) && hctx->queue->mq_ops->commit_rqs && queued)

		hctx->queue->mq_ops->commit_rqs(hctx);

}