From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <linux-kernel-owner@vger.kernel.org>
Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand
	id S1751914AbcDZA7J (ORCPT <rfc822;w@1wt.eu>);
	Mon, 25 Apr 2016 20:59:09 -0400
Received: from mail-pa0-f46.google.com ([209.85.220.46]:36614 "EHLO
	mail-pa0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org
	with ESMTP id S1750843AbcDZA7H (ORCPT
	<rfc822;linux-kernel@vger.kernel.org>);
	Mon, 25 Apr 2016 20:59:07 -0400
Subject: Re: [PATCH] MD: make bio mergeable
To: Shaohua Li <shli@fb.com>, linux-block@vger.kernel.org,
        linux-kernel@vger.kernel.org, linux-raid@vger.kernel.org
References: <384a0e0c7d6f2700aadbcbdef003cece88fa7dd7.1461626533.git.shli@fb.com>
Cc: qkrwngud825@gmail.com, Kernel-team@fb.com,
        "v4.3+" <stable@vger.kernel.org>, Ming Lei <ming.lei@canonical.com>,
        Jens Axboe <axboe@fb.com>, Neil Brown <neilb@suse.de>
From: Jens Axboe <axboe@kernel.dk>
Message-ID: <571EBD56.7010204@kernel.dk>
Date: Mon, 25 Apr 2016 18:59:02 -0600
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101
 Thunderbird/38.6.0
MIME-Version: 1.0
In-Reply-To: <384a0e0c7d6f2700aadbcbdef003cece88fa7dd7.1461626533.git.shli@fb.com>
Content-Type: text/plain; charset=windows-1252; format=flowed
Content-Transfer-Encoding: 7bit
Sender: linux-kernel-owner@vger.kernel.org
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

On 04/25/2016 05:52 PM, Shaohua Li wrote:
> blk_queue_split marks bio unmergeable, which makes sense for normal bio.
> But if dispatching the bio to underlayer disk, the blk_queue_split
> checks are invalid, hence it's possible the bio becomes mergeable.
>
> In the reported bug, this bug causes trim against raid0 performance slash
> https://bugzilla.kernel.org/show_bug.cgi?id=117051

Good catch! Will apply for this series, thanks Shaohua.

-- 
Jens Axboe