From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from cuda.sgi.com (cuda2.sgi.com [192.48.176.25]) by oss.sgi.com (8.14.3/8.14.3/SuSE Linux 0.8) with ESMTP id q572Dw5H027064 for ; Wed, 6 Jun 2012 21:13:59 -0500 Received: from ipmail06.adl2.internode.on.net (ipmail06.adl2.internode.on.net [150.101.137.129]) by cuda.sgi.com with ESMTP id UpWzYCRW9ln682cA for ; Wed, 06 Jun 2012 19:13:57 -0700 (PDT) Date: Thu, 7 Jun 2012 12:13:53 +1000 From: Dave Chinner Subject: Re: [PATCH] xfs: re-enable xfsaild idle mode and fix associated races Message-ID: <20120607021353.GR22848@dastard> References: <1337875602-63025-1-git-send-email-bfoster@redhat.com> <4FCCEF94.7020501@sgi.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <4FCCEF94.7020501@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: Mark Tinguely Cc: Brian Foster , xfs@oss.sgi.com On Mon, Jun 04, 2012 at 12:25:40PM -0500, Mark Tinguely wrote: > On 05/24/12 11:06, Brian Foster wrote: > >xfsaild idle mode logic currently leads to a couple hangs: > > > >1.) If xfsaild is rescheduled in during an incremental scan > > (i.e., tout != 0) and the target has been updated since > > the previous run, we can hit the new target and go into > > idle mode with a still populated ail. > >2.) A wake up is only issued when the target is pushed forward. > > The wake up can race with xfsaild if it is currently in the > > process of entering idle mode, causing future wake up > > events to be lost. > > > >Both hangs are reproducible by running xfstests 273 in a loop. > >Modify xfsaild to enter idle mode only when the ail is empty > >and the push target has not been moved forward since the last > >push. > > > >Signed-off-by: Brian Foster > >--- > > I wouldn't mind keeping an large (a few minutes) wake up value for the > empty AIL case to be paranoid. And then we'll never hear about hangs.... Cheers, Dave. -- Dave Chinner david@fromorbit.com _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs