From da41a589f52464e24ddefe76814ee35bfb07950c Mon Sep 17 00:00:00 2001 From: Robert Elliott Date: Tue, 20 May 2014 16:46:26 -0500 Subject: blk-mq: Micro-optimize blk_queue_nomerges() check In blk_mq_make_request(), do the blk_queue_nomerges() check outside the call to blk_attempt_plug_merge() to eliminate function call overhead when nomerges=2 (disabled) Signed-off-by: Robert Elliott Signed-off-by: Jens Axboe --- block/blk-mq.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'block/blk-mq.c') diff --git a/block/blk-mq.c b/block/blk-mq.c index fec8fcc4f8a4..ef7ed5e95d6d 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -1087,7 +1087,8 @@ static void blk_mq_make_request(struct request_queue *q, struct bio *bio) return; } - if (use_plug && blk_attempt_plug_merge(q, bio, &request_count)) + if (use_plug && !blk_queue_nomerges(q) && + blk_attempt_plug_merge(q, bio, &request_count)) return; if (blk_mq_queue_enter(q)) { -- cgit v1.2.3