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 p9A1jDfD138002 for ; Sun, 9 Oct 2011 20:45:14 -0500 Received: from ipmail05.adl6.internode.on.net (localhost [127.0.0.1]) by cuda.sgi.com (Spam Firewall) with ESMTP id BD18B152EA0E for ; Sun, 9 Oct 2011 18:52:19 -0700 (PDT) Received: from ipmail05.adl6.internode.on.net (ipmail05.adl6.internode.on.net [150.101.137.143]) by cuda.sgi.com with ESMTP id DWsuoiEFJ2JzUBdS for ; Sun, 09 Oct 2011 18:52:19 -0700 (PDT) Date: Mon, 10 Oct 2011 12:45:09 +1100 From: Dave Chinner Subject: Re: [PATCH 3/4] xfs: revert to using a kthread for AIL pushing Message-ID: <20111010014509.GT3159@dastard> References: <20111006183257.036884724@bombadil.infradead.org> <20111006183549.770414484@bombadil.infradead.org> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20111006183549.770414484@bombadil.infradead.org> List-Id: XFS Filesystem from SGI List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: xfs-bounces@oss.sgi.com Errors-To: xfs-bounces@oss.sgi.com To: Christoph Hellwig Cc: Stefan Priebe , xfs@oss.sgi.com On Thu, Oct 06, 2011 at 02:33:00PM -0400, Christoph Hellwig wrote: > Currently we have a few issues with the way the workqueue code is used to > implement AIL pushing: > > - it accidentally uses the same workqueue as the syncer action, and thus > can be prevented from running if there are enough sync actions active > in the system. > - it doesn't use the HIGHPRI flag to queue at the head of the queue of > work items > > At this point I'm not confident enough in getting all the workqueue flags and > tweaks right to provide a perfectly reliable execution context for AIL > pushing, which is the most important piece in XFS to make forward progress > when the log fills. > > Revert back to use a kthread per filesystem which fixes all the above issues > at the cost of having a task struct and stack around for each mounted > filesystem. In addition this also gives us much better ways to diagnose > any issues involving hung AIL pushing and removes a small amount of code. > > Signed-off-by: Christoph Hellwig > Reported-by: Stefan Priebe > Tested-by: Stefan Priebe I'd much prefer to fix the problems with the workqueue usage than revert back to using a thread, but seeing as I cannot reproduce the hangs I can't really track down whatever problem there is. So, a bit reluctantly: Reviewed-by: Dave Chinner -- Dave Chinner david@fromorbit.com _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs