From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759333Ab2CSTiO (ORCPT ); Mon, 19 Mar 2012 15:38:14 -0400 Received: from dwdmx5.dwd.de ([141.38.3.242]:39758 "EHLO dwdmx5.dwd.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755331Ab2CSTiN (ORCPT ); Mon, 19 Mar 2012 15:38:13 -0400 Date: Mon, 19 Mar 2012 19:38:04 +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, vgoyal@redhat.com, martin.petersen@oracle.com Subject: Re: [patch v2 0/6] Add TRIM support for raid linear/0/1/10 In-Reply-To: <20120316073213.656519005@fusionio.com> Message-ID: References: <20120316073213.656519005@fusionio.com> User-Agent: Alpine 2.02 (LRH 1266 2009-07-14) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; format=flowed; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello, On Fri, 16 Mar 2012, Shaohua Li wrote: > The patches add TRIM support for raid linear/0/1/10. I'll add TRIM support for > raid 4/5/6 later. The implementation is pretty straightforward and > self-explained. > > v1->v2: > 1. fixed a checking issue > 2. dropped discard request plug and replace it with no discard merege, because > current SCSI layer can't handle discard request merge. > Have tested TRIM patches on three different systems with the following hardware/ setup: 1) root mounted on a raid1 over two SAS SSD's (200GB) and /home partition on a raid0 over a fusionio ioDrive Duo. Is very new and seen very little usage. 2) root and /home mounted on a raid0 over two Intel X25 Postville (160GB) connected to a Intel P55 Express chipset. Has seen very heavy usage for approx. 2 years. 3) root and /home mounted on a raid0 over three OCZ-VERTEX2 (120GB) connected via ICH7 south bridge. Has seen mild usage for approx. 1.5 years. Made the following observations when running my own benchmark which copies around a lot of small files and deletes them. The benchmark on all systems was always run only on the /home partition ie. on a raid0. For system 1) there is hardly any measurable differnce whether discard is enabled or not (~29000 files per second). On system 2) the performance drops from 6500->3700 files per second, but under normal usage one does not notice any difference. System 3) has problems during boot, it is so slow that some operations receive a timeout during boot: udevd[474]: timeout '/sbin/blkid -o udev -p /dev/md0' udevd[474]: timeout: killing '/sbin/blkid -o udev -p /dev/md0' [866] systemd[1]: dev-md3.swap activation timed out. Stopping. Even removing discard does not help and the above errors happen during boot and booting takes a long time. The performance in the benchmark drops from 4000->600 files per second. Regards, Holger