From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757275Ab2CMPve (ORCPT ); Tue, 13 Mar 2012 11:51:34 -0400 Received: from mx1.redhat.com ([209.132.183.28]:3822 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757078Ab2CMPvc (ORCPT ); Tue, 13 Mar 2012 11:51:32 -0400 Date: Tue, 13 Mar 2012 11:51:20 -0400 From: Vivek Goyal To: Shaohua Li Cc: linux-kernel@vger.kernel.org, linux-raid@vger.kernel.org, neilb@suse.de, axboe@kernel.dk, Shaohua Li , "Martin K. Petersen" Subject: Re: [patch 6/7] blk: add plug for blkdev_issue_discard Message-ID: <20120313155120.GG29169@redhat.com> References: <20120312030412.375458948@fusionio.com> <20120312031305.946211513@fusionio.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20120312031305.946211513@fusionio.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Mar 12, 2012 at 11:04:18AM +0800, Shaohua Li wrote: > In raid 0 case, a big discard request is divided into several small requests > in chunk_size unit. Such requests can be merged in low layer if we have > correct plug added. This should improve the performance a little bit. Martin posted a patch to remove the support for allowing merging of discard requests. But this seems to be a reasonable use case for allowing mering discard requests. CCing Martin. Thanks Vivek