Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751914AbcDZA7J (ORCPT ); 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 ); Mon, 25 Apr 2016 20:59:07 -0400 Subject: Re: [PATCH] MD: make bio mergeable To: Shaohua Li , 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+" , Ming Lei , Jens Axboe , Neil Brown From: Jens Axboe 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: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 459 Lines: 12 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