Commit dad7a3be authored Jun 06, 2017 by Ming Lei Committed by Jens Axboe Jun 06, 2017

blk-mq: pass correct hctx to blk_mq_try_issue_directly



When direct issue is done on request picked up from plug list,
the hctx need to be updated with the actual hw queue, otherwise
wrong hctx is used and may hurt performance, especially when
wrong SRCU readlock is acquired/released

Reported-by: Bart Van Assche <bart.vanassche@sandisk.com>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

parent 3116a23b

block/blk-mq.c

+4 −1

Original line number	Diff line number	Diff line
		@@ -1619,9 +1619,12 @@ static blk_qc_t blk_mq_make_request(struct request_queue q, struct bio bio)

		blk_mq_put_ctx(data.ctx);

		if (same_queue_rq)
		if (same_queue_rq) {
		data.hctx = blk_mq_map_queue(q,
		same_queue_rq->mq_ctx->cpu);
		blk_mq_try_issue_directly(data.hctx, same_queue_rq,
		&cookie);
		}
		} else if (q->nr_hw_queues > 1 && is_sync) {
		blk_mq_put_ctx(data.ctx);
		blk_mq_bio_to_request(rq, bio);