Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759119AbYBRKWX (ORCPT ); Mon, 18 Feb 2008 05:22:23 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1758739AbYBRKWM (ORCPT ); Mon, 18 Feb 2008 05:22:12 -0500 Received: from netops-testserver-3-out.sgi.com ([192.48.171.28]:42725 "EHLO relay.sgi.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1756067AbYBRKWK (ORCPT ); Mon, 18 Feb 2008 05:22:10 -0500 Date: Mon, 18 Feb 2008 21:21:50 +1100 From: David Chinner To: =?iso-8859-1?B?VPZy9ms=?= Edwin Cc: David Chinner , Oliver Pinter , xfs@oss.sgi.com, Linux Kernel , Arjan van de Ven , Christoph Lameter , Christoph Hellwig Subject: Re: xfsaild causing 30+ wakeups/s on an idle system since 2.6.25-rcX Message-ID: <20080218102150.GL155407@sgi.com> References: <47B863A9.5070206@gmail.com> <6101e8c40802170851w73db8130t9bcfdc5cf053f0dc@mail.gmail.com> <20080217224736.GX155407@sgi.com> <47B952D3.2030900@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <47B952D3.2030900@gmail.com> User-Agent: Mutt/1.4.2.1i Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1457 Lines: 46 On Mon, Feb 18, 2008 at 11:41:39AM +0200, T?r?k Edwin wrote: > David Chinner wrote: > > On Sun, Feb 17, 2008 at 05:51:08PM +0100, Oliver Pinter wrote: > > > >> On 2/17/08, T?r?k Edwin wrote: > >> > >>> Hi, > >>> > >>> xfsaild is causing many wakeups, a quick investigation shows > >>> xfsaild_push is always > >>> returning 30 msecs timeout value. > >>> > > > > That's a bug > > Ok. Your patches fixes the 30+ wakeups :) Good. I'll push it out for review then. > > , and has nothing to do with power consumption. ;) > > > > I suggest using a sysctl value (such as > /proc/sys/vm/dirty_writeback_centisecs), instead of a hardcoded default > 1000. No, too magic. I dislike adding knobs to workaround issues that really should be fixed by having sane default behaviour. Further down the track as we correct know issues with the AIL push code we'll be able to increase this idle timeout or even make it purely wakeup driven once we get back to an idle state. However, right now it still needs that once a second wakeup to work around a nasty corner case that can hang the filesystem.... Cheers, Dave. -- Dave Chinner Principal Engineer SGI Australian Software Group -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/