From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from cuda.sgi.com (cuda3.sgi.com [192.48.176.15]) by oss.sgi.com (8.14.3/8.14.3/SuSE Linux 0.8) with ESMTP id p9JBGSEO180922 for ; Wed, 19 Oct 2011 06:16:29 -0500 Received: from server655-han.de-nserver.de (localhost [127.0.0.1]) by cuda.sgi.com (Spam Firewall) with ESMTP id AA4A21C9A92A for ; Wed, 19 Oct 2011 04:16:25 -0700 (PDT) Received: from server655-han.de-nserver.de (server655-han.de-nserver.de [85.158.177.45]) by cuda.sgi.com with ESMTP id BPIc4yMDVrFwRUug for ; Wed, 19 Oct 2011 04:16:25 -0700 (PDT) Message-ID: <4E9EB187.40306@profihost.ag> Date: Wed, 19 Oct 2011 13:16:23 +0200 From: Stefan Priebe - Profihost AG MIME-Version: 1.0 Subject: Re: [PATCH 3/4] xfs: revert to using a kthread for AIL pushing References: <20111006183257.036884724@bombadil.infradead.org> <20111006183549.770414484@bombadil.infradead.org> <20111010014509.GT3159@dastard> <20111010055546.GA1641@x4.trippels.de> In-Reply-To: <20111010055546.GA1641@x4.trippels.de> List-Id: XFS Filesystem from SGI List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Sender: xfs-bounces@oss.sgi.com Errors-To: xfs-bounces@oss.sgi.com To: Markus Trippelsdorf Cc: Christoph Hellwig , Tejun Heo , xfs@oss.sgi.com > On 2011.10.10 at 12:45 +1100, Dave Chinner wrote: >> 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: Any news on this problem? What happens with the next long term stable kernel 3.0.X? How do you proceed with this bug? Stefan _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs