blk-mq: use list_splice_tail_init() to insert requests (3f0cedc7) · Commits · 戴 / test

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: Laurence Oberman <loberman@redhat.com> Cc: Omar Sandoval <osandov@fb.com> Cc: Bart Van Assche <bart.vanassche@wdc.com> Tested-by:

Kashyap Desai <kashyap.desai@broadcom.com> Reviewed-by:

Christoph Hellwig <hch@lst.de> Signed-off-by:

Ming Lei <ming.lei@redhat.com> Signed-off-by:

Jens Axboe <axboe@kernel.dk>

block/blk-mq.c

+7 −7

Original line number	Diff line number	Diff line
		@@ -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);
		}

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