Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750814AbVIWIpu (ORCPT ); Fri, 23 Sep 2005 04:45:50 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1750815AbVIWIpu (ORCPT ); Fri, 23 Sep 2005 04:45:50 -0400 Received: from ppp-217-133-42-200.cust-adsl.tiscali.it ([217.133.42.200]:1324 "EHLO x30.random") by vger.kernel.org with ESMTP id S1750814AbVIWIpu (ORCPT ); Fri, 23 Sep 2005 04:45:50 -0400 Date: Fri, 23 Sep 2005 10:45:29 +0200 From: Andrea Arcangeli To: Valdis.Kletnieks@vt.edu Cc: Con Kolivas , linux-kernel@vger.kernel.org Subject: Re: 2.6.14-rc2-mm1 - ext3 wedging up Message-ID: <20050923084529.GD10859@x30.random> References: <200509221959.j8MJxJsY010193@turing-police.cc.vt.edu> <200509231036.16921.kernel@kolivas.org> <200509230720.j8N7KYGX023826@turing-police.cc.vt.edu> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <200509230720.j8N7KYGX023826@turing-police.cc.vt.edu> User-Agent: Mutt/1.5.9i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1815 Lines: 41 On Fri, Sep 23, 2005 at 03:20:33AM -0400, Valdis.Kletnieks@vt.edu wrote: > On Fri, 23 Sep 2005 10:36:16 +1000, Con Kolivas said: > > (Adding Andrea to the To: list...) > > > On Fri, 23 Sep 2005 05:59, Valdis.Kletnieks@vt.edu wrote: > > > Am seeing reproducible wedging up when writing large (20M+) files to an > > > ext3 file system. Oddly enough, if something *else* writes files to the > > > file system as well, it will unwedge for a while and make progress. Also, So you get a total hang? I guess there's a bug somewhere... > I'm pretty convinced that for this patch to work, it *will* need feedback from > the actual (not max) disk bandwidth and possibly the actual amount of RAM - > what works on Andrea's 1G workstation with (presumably) a real disk system > is waay too much for 256M and a single laptop-class disk. That's not the problem here if you get a total hang. This heuristic should only reduce the amount of dirty memory, it should never grind a task to a total hang, until some other task writes to the filesystem. The sysrq shows the task sleeping in blk_congestion_wait. > For now, I'm leaving centisecs set to 40, and will see how that works - most > of my "problem cases" involve an FTP on a 10/100mbit connection, so that will > get tried tomorrow..... You should leave it to 0 until I find the buglet that hangs the system. I'll have a look. One other thing to change is to call balance_dirty only when the dirty bit is toggled (so overwrites of dirty cache are not accounted, since they generate no additional I/O on disk). Thanks. - 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/