From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: with ECARTIS (v1.0.0; list xfs); Sat, 23 Aug 2008 05:48:47 -0700 (PDT) Received: from cuda.sgi.com (cuda1.sgi.com [192.48.168.28]) by oss.sgi.com (8.12.11.20060308/8.12.11/SuSE Linux 0.7) with ESMTP id m7NCmfjt016729 for ; Sat, 23 Aug 2008 05:48:42 -0700 Received: from emh02.mail.saunalahti.fi (localhost [127.0.0.1]) by cuda.sgi.com (Spam Firewall) with ESMTP id F0AB8FACC0A for ; Sat, 23 Aug 2008 05:50:02 -0700 (PDT) Received: from emh02.mail.saunalahti.fi (emh02.mail.saunalahti.fi [62.142.5.108]) by cuda.sgi.com with ESMTP id lhlGEiLCXMeYanwA for ; Sat, 23 Aug 2008 05:50:02 -0700 (PDT) Date: Sat, 23 Aug 2008 15:52:31 +0300 (MET DST) From: Szabolcs Szakacsits Subject: Re: XFS vs Elevators (was Re: [PATCH RFC] nilfs2: continuous snapshotting file system) In-Reply-To: Message-ID: References: <200808201613.AA00212@capsicum.lab.ntt.co.jp> <20080820143916.1a7eddab.akpm@linux-foundation.org> <20080821021259.GA5706@disturbed> <20080821051508.GB5706@disturbed> <20080821060418.GC5706@disturbed> <20080821082532.GE5706@disturbed> <20080822022459.GL5706@disturbed> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: xfs-bounce@oss.sgi.com Errors-to: xfs-bounce@oss.sgi.com List-Id: xfs To: Dave Chinner Cc: Andrew Morton , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, xfs@oss.sgi.com On Fri, 22 Aug 2008, Szabolcs Szakacsits wrote: > On Fri, 22 Aug 2008, Dave Chinner wrote: > > On Thu, Aug 21, 2008 at 08:33:50PM +0300, Szabolcs Szakacsits wrote: > > > > > The 'nobarrier' mount option made a big improvement: > > > > INteresting. Barriers make only a little difference on my laptop; > > 10-20% slower. But yes, barriers will have this effect on XFS. > > > > If you've got NCQ, then you'd do better to turn off write caching > > on the drive, turn off barriers and use NCQ to give you back the > > performance that the write cache used to. That is, of course, > > assuming the NCQ implementation doesn't suck.... > > Write cache off, nobarrier and AHCI NCQ lowered the XFS result: > > MB/s Runtime (s) > ----- ----------- > btrfs unstable 17.09 572 > ext3 13.24 877 > btrfs 0.16 12.33 793 > ntfs-3g unstable 11.52 673 > nilfs2 2nd+ runs 11.29 674 > reiserfs 8.38 966 > xfs nobarrier 7.89 949 > nilfs2 1st run 4.95 3800 > xfs nobarrier, ncq, wc off 3.81 1973 > xfs 1.88 3901 Retested with a different disk, SATA-II, NCQ, capable of 70-110 MB/s read/write: MB/s Runtime (s) ----- ----------- btrfs unstable, no dup 51.42 168 btrfs unstable 42.67 197 ext4 2.6.26 35.63 245 nilfs2 2nd+ runs 26.43 287 ntfs-3g unstable 21.41 370 ext3 19.92 559 xfs nobarrier 14.17 562 reiserfs 13.11 595 nilfs2 1st run 12.06 3719 xfs nobarrier, ncq, wc off 6.89 1070 xfs 1.95 3786 Szaka -- NTFS-3G: http://ntfs-3g.org