From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932559Ab2CNVNN (ORCPT ); Wed, 14 Mar 2012 17:13:13 -0400 Received: from dwdmx5.dwd.de ([141.38.3.242]:48884 "EHLO dwdmx5.dwd.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932188Ab2CNVNJ (ORCPT ); Wed, 14 Mar 2012 17:13:09 -0400 Date: Wed, 14 Mar 2012 21:13:02 +0000 (GMT) From: Holger Kiehl X-X-Sender: kiehl@diagnostix.dwd.de To: Shaohua Li cc: "linux-kernel@vger.kernel.org" , "linux-raid@vger.kernel.org" , "neilb@suse.de" , "axboe@kernel.dk" Subject: Re: [patch 0/7] Add TRIM support for raid linear/0/1/10 In-Reply-To: Message-ID: References: <20120312030412.375458948@fusionio.com> <4F5EFEB6.4060402@kernel.org> User-Agent: Alpine 2.02 (LRH 1266 2009-07-14) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 14 Mar 2012, Shaohua Li wrote: > Maybe the discard runs slow with small size request in the disk. > please drop patch "blk: add plug for blkdev_issue_discard" and try again. Since > we can't do merge, the plug just introduces latency. > Tried again without the patch applied, but there is only a very small performance increase (520->600 agains 4000 fps without discard). The benchmark creates lots of small files (2 KiB) and deletes them again. > if it doesn't help, please capture a blktrace when you do the benchmark and > send it to me. > Ok, I will do this tomorrow. Need some sleep :-) Thanks for your work on supporting discard in MD! Regards, Holger