From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752597AbbJTPOe (ORCPT ); Tue, 20 Oct 2015 11:14:34 -0400 Received: from mail-pa0-f48.google.com ([209.85.220.48]:35559 "EHLO mail-pa0-f48.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752671AbbJTPO3 (ORCPT ); Tue, 20 Oct 2015 11:14:29 -0400 From: Ming Lei To: Jens Axboe , linux-kernel@vger.kernel.org Cc: Ming Lin , Kent Overstreet , Christoph Hellwig , Jeff Moyer , Ming Lei Subject: [PATCH v2 5/7] block: check bio_mergeable() early before merging Date: Tue, 20 Oct 2015 23:13:55 +0800 Message-Id: <1445354037-27000-6-git-send-email-ming.lei@canonical.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1445354037-27000-1-git-send-email-ming.lei@canonical.com> References: <1445354037-27000-1-git-send-email-ming.lei@canonical.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 --- 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