After bio splitting is introduced, one bio can be splitted and it is marked as NOMERGE because it is too fat to be merged, so check bio_mergeable() earlier to avoid to try to merge it unnecessarily.
Signed-off-by: Ming Lei <ming....@canonical.com> --- block/elevator.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/block/elevator.c b/block/elevator.c index 84d6394..c3555c9 100644 --- a/block/elevator.c +++ b/block/elevator.c @@ -420,7 +420,7 @@ int elv_merge(struct request_queue *q, struct request **req, struct bio *bio) * noxmerges: Only simple one-hit cache try * merges: All merge tries attempted */ - if (blk_queue_nomerges(q)) + if (blk_queue_nomerges(q) || !bio_mergeable(bio)) return ELEVATOR_NO_MERGE; /* -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/