From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Ming Lei To: Jens Axboe Cc: linux-block@vger.kernel.org, Ming Lei , Kashyap Desai , Laurence Oberman , Omar Sandoval , Christoph Hellwig , Bart Van Assche Subject: [PATCH V2 1/3] blk-mq: use list_splice_tail_init() to insert requests Date: Fri, 29 Jun 2018 16:12:50 +0800 Message-Id: <20180629081252.13836-2-ming.lei@redhat.com> In-Reply-To: <20180629081252.13836-1-ming.lei@redhat.com> References: <20180629081252.13836-1-ming.lei@redhat.com> List-ID: list_splice_tail_init() is much more faster than inserting each request one by one, given all requets in 'list' belong to same sw queue and ctx->lock is required to insert requests. Cc: Kashyap Desai Cc: Laurence Oberman Cc: Omar Sandoval Cc: Christoph Hellwig Cc: Bart Van Assche Signed-off-by: Ming Lei --- block/blk-mq.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-) diff --git a/block/blk-mq.c b/block/blk-mq.c index 22fe394d0b49..359382b59d40 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -1545,19 +1545,19 @@ void blk_mq_insert_requests(struct blk_mq_hw_ctx *hctx, struct blk_mq_ctx *ctx, struct list_head *list) { + struct request *rq; + /* * preemption doesn't flush plug list, so it's possible ctx->cpu is * offline now */ - spin_lock(&ctx->lock); - while (!list_empty(list)) { - struct request *rq; - - rq = list_first_entry(list, struct request, queuelist); + list_for_each_entry(rq, list, queuelist) { BUG_ON(rq->mq_ctx != ctx); - list_del_init(&rq->queuelist); - __blk_mq_insert_req_list(hctx, rq, false); + trace_block_rq_insert(hctx->queue, rq); } + + spin_lock(&ctx->lock); + list_splice_tail_init(list, &ctx->rq_list); blk_mq_hctx_mark_pending(hctx, ctx); spin_unlock(&ctx->lock); } -- 2.9.5