From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from relay.sgi.com (relay1.corp.sgi.com [137.38.102.111]) by oss.sgi.com (8.14.3/8.14.3/SuSE Linux 0.8) with ESMTP id p97MJ9nA002368 for ; Fri, 7 Oct 2011 17:19:09 -0500 Subject: Re: [PATCH 3/4] xfs: revert to using a kthread for AIL pushing From: Alex Elder In-Reply-To: <20111006183549.770414484@bombadil.infradead.org> References: <20111006183257.036884724@bombadil.infradead.org> <20111006183549.770414484@bombadil.infradead.org> Date: Fri, 7 Oct 2011 17:18:20 -0500 Message-ID: <1318025900.2810.79.camel@doink> MIME-Version: 1.0 Reply-To: aelder@sgi.com 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 , chinner@redhat.com Cc: Stefan Priebe , xfs@oss.sgi.com On Thu, 2011-10-06 at 14:33 -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 Looks good. Dave, I don't want to commit this (series) until you have had a chance to review it. Reviewed-by: Alex Elder _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs