From: Eric Sandeen Subject: Re: [ext3] kjournald writing after each read despite noatime,commit=nnn Date: Thu, 01 Jan 2009 14:16:38 -0600 Message-ID: <495D24A6.7010707@redhat.com> References: <18779.58377.160214.225792@wellington.i202.centerclick.org> <495CCCDF.3030606@samwel.tk> <18780.62500.100687.402706@wellington.i202.centerclick.org> <495D12A8.9030703@samwel.tk> <18781.5890.617086.393467@wellington.i202.centerclick.org> <18781.6904.837987.584032@wellington.i202.centerclick.org> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: Bart Samwel , linux-kernel@vger.kernel.org, linux-ext4@vger.kernel.org To: Dave Johnson Return-path: Received: from mx2.redhat.com ([66.187.237.31]:56591 "EHLO mx2.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750741AbZAAUQr (ORCPT ); Thu, 1 Jan 2009 15:16:47 -0500 In-Reply-To: <18781.6904.837987.584032@wellington.i202.centerclick.org> Sender: linux-ext4-owner@vger.kernel.org List-ID: Dave Johnson wrote: > Dave Johnson writes: >> Bart Samwel writes: >>> This looks like it's a generic property of syncing an ext3 file system. >>> Try turning off laptop_mode and then running "sync". You will probably >>> see the same behaviour. >> yep, every sync() causes a gratuitous write to disk N seconds later >> even when no data has been read or written since the last sync(). > > Woops, correction, every sync() call causes a single gratuitous write, > no delay. > > $ for n in 1 2 3 4 5; do sync; done > > Jan 1 14:32:54 gw kernel: kjournald(760): WRITE block 2682 on hda1 > Jan 1 14:32:54 gw kernel: kjournald(760): WRITE block 2684 on hda1 > Jan 1 14:32:54 gw kernel: kjournald(760): WRITE block 2686 on hda1 > Jan 1 14:32:54 gw kernel: kjournald(760): WRITE block 2688 on hda1 > Jan 1 14:32:54 gw kernel: kjournald(760): WRITE block 2690 on hda1 > This may be http://bugzilla.kernel.org/show_bug.cgi?id=12224 -Eric