From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from cuda.sgi.com (cuda1.sgi.com [192.48.157.11]) by oss.sgi.com (8.14.3/8.14.3/SuSE Linux 0.8) with ESMTP id q04D9KYf137014 for ; Wed, 4 Jan 2012 07:09:21 -0600 Received: from smtp-tls.univ-nantes.fr (smtp-tls2.univ-nantes.fr [193.52.101.146]) by cuda.sgi.com with ESMTP id Z4sLW5hYPTFgBD6o for ; Wed, 04 Jan 2012 05:09:19 -0800 (PST) Message-ID: <4F044EC7.3030203@univ-nantes.fr> Date: Wed, 04 Jan 2012 14:06:15 +0100 From: Yann Dupont MIME-Version: 1.0 Subject: Re: Bad performance with XFS + 2.6.38 / 2.6.39 References: <4EF1A224.2070508@univ-nantes.fr> <4EF1F6DD.8020603@hardwarefreak.com> <4EF21DD2.3060004@univ-nantes.fr> <20111221222623.GF23662@dastard> <4EF2F702.4050902@univ-nantes.fr> <4EF30E5D.7060608@univ-nantes.fr> <4F0181A2.5010505@univ-nantes.fr> <20120102203543.GP23662@dastard> <4F02BA35.9040909@univ-nantes.fr> <20120104123331.GA12204@infradead.org> In-Reply-To: <20120104123331.GA12204@infradead.org> List-Id: XFS Filesystem from SGI List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="iso-8859-1"; Format="flowed" Sender: xfs-bounces@oss.sgi.com Errors-To: xfs-bounces@oss.sgi.com To: Christoph Hellwig Cc: stan@hardwarefreak.com, xfs@oss.sgi.com On 04/01/2012 13:33, Christoph Hellwig wrote: > On Tue, Jan 03, 2012 at 09:20:05AM +0100, Yann Dupont wrote: >>> As it is, I can't see any material difference between the traces. >>> both reads and writes are taking the same amount of time to service, >>> so I don't think there's any problem here. >> >> ok, >>> >>> I do recall that some years ago that we changed one of the ways we >> >> Do you recall exactly what some years ago means ? Is this post 2.6.26 er= a ? > > The only thing that I remember is Jens switching xfs_buf_wait_unpin from > schedule to io_schedule in "block: remove per-queue plugging", which > went into Linux 2.6.39. With this processed that wait for buffers to > be unpinned now count towards the load average. > Ok, that's probably the root cause. As I already said, I don't = experience performance regression right now. Thanks a lot for the explaination. Cheers, -- = Yann Dupont - Service IRTS, DSI Universit=E9 de Nantes Tel : 02.53.48.49.20 - Mail/Jabber : Yann.Dupont@univ-nantes.fr _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs