blk-mq: immediately dispatch big size request (600271d9) · Commits · 戴 / test

This is corresponding part for blk-mq. Disk with multiple hardware queues doesn't need this as we only hold 1 request at most. Signed-off-by:

block/blk-mq.c

+6 −1

Original line number	Diff line number	Diff line
		@@ -1453,13 +1453,18 @@ static blk_qc_t blk_sq_make_request(struct request_queue q, struct bio bio)
		*/
		plug = current->plug;
		if (plug) {
		struct request *last = NULL;

		blk_mq_bio_to_request(rq, bio);
		if (!request_count)
		trace_block_plug(q);
		else
		last = list_entry_rq(plug->mq_list.prev);

		blk_mq_put_ctx(data.ctx);

		if (request_count >= BLK_MAX_REQUEST_COUNT) {
		if (request_count >= BLK_MAX_REQUEST_COUNT \|\| (last &&
		blk_rq_bytes(last) >= BLK_PLUG_FLUSH_SIZE)) {
		blk_flush_plug_list(plug, false);
		trace_block_plug(q);
		}