blk-mq: check bio_mergeable() early before merging

It isn't necessary to try to merge the bio which is marked as NOMERGE. Reviewed-by: Jeff Moyer <[email protected]> Signed-off-by: Ming Lei <[email protected]> Signed-off-by: Jens Axboe <[email protected]>
iegor · Oct 21, 2015 · e18378a · e18378a
1 parent 6ac45ae
commit e18378a
Showing 1 changed file with 1 addition and 1 deletion.
diff --git a/block/blk-mq.c b/block/blk-mq.c
@@ -1140,7 +1140,7 @@ static inline bool blk_mq_merge_queue_io(struct blk_mq_hw_ctx *hctx,
 					 struct blk_mq_ctx *ctx,
 					 struct request *rq, struct bio *bio)
 {
-	if (!hctx_allow_merges(hctx)) {
+	if (!hctx_allow_merges(hctx) || !bio_mergeable(bio)) {
 		blk_mq_bio_to_request(rq, bio);
 		spin_lock(&ctx->lock);
 insert_rq: