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authorRobert Elliott <elliott@hp.com>2014-05-21 01:46:26 +0400
committerJens Axboe <axboe@fb.com>2014-05-21 01:49:03 +0400
commitda41a589f52464e24ddefe76814ee35bfb07950c (patch)
treee3270f36a1a5766e2433b70b0eef4e2205096075 /block/blk-mq.c
parenteba7176826ddab1d04c51bb2d5f2bbf22865444c (diff)
downloadlinux-da41a589f52464e24ddefe76814ee35bfb07950c.tar.xz
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 <elliott@hp.com> Signed-off-by: Jens Axboe <axboe@fb.com>
Diffstat (limited to 'block/blk-mq.c')
-rw-r--r--block/blk-mq.c3
1 files changed, 2 insertions, 1 deletions
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)) {