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 SMTP id p2AMl9tp126237 for ; Thu, 10 Mar 2011 16:47:15 -0600 Received: from ipmail06.adl6.internode.on.net (localhost [127.0.0.1]) by cuda.sgi.com (Spam Firewall) with ESMTP id 701381363CC2 for ; Thu, 10 Mar 2011 14:49:49 -0800 (PST) Received: from ipmail06.adl6.internode.on.net (ipmail06.adl6.internode.on.net [150.101.137.145]) by cuda.sgi.com with ESMTP id xEFcuBXo8LSwXwDG for ; Thu, 10 Mar 2011 14:49:49 -0800 (PST) Date: Fri, 11 Mar 2011 09:49:45 +1100 From: Dave Chinner Subject: Re: [PATCH] xfs: flush vmap aliases when mapping fails Message-ID: <20110310224945.GA15097@dastard> References: <1299713876-7747-1-git-send-email-david@fromorbit.com> <20110310073751.GB25374@infradead.org> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20110310073751.GB25374@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: linux-mm@kvack.org, npiggin@kernel.dk, xfs@oss.sgi.com On Thu, Mar 10, 2011 at 02:37:51AM -0500, Christoph Hellwig wrote: > On Thu, Mar 10, 2011 at 10:37:56AM +1100, Dave Chinner wrote: > > From: Dave Chinner > > > > On 32 bit systems, vmalloc space is limited and XFS can chew through > > it quickly as the vmalloc space is lazily freed. This can result in > > failure to map buffers, even when there is apparently large amounts > > of vmalloc space available. Hence, if we fail to map a buffer, purge > > the aliases that have not yet been freed to hopefuly free up enough > > vmalloc space to allow a retry to succeed. > > IMHO this should be done by vm_map_ram internally. If we can't get the > core code fixes we can put this in as a last resort. OK. The patch was done as part of the triage for this bug: https://bugzilla.kernel.org/show_bug.cgi?id=27492 where the vmalloc space on 32 bit systems is getting exhausted. I can easily move this flush-and-retry into the vmap code. FWIW, while the VM folk might be paying attention about vmap realted stuff, this vmap BUG() also needs triage: https://bugzilla.kernel.org/show_bug.cgi?id=27002 And, finally, the mm-vmap-area-cache.patch in the current mmotm also needs to be pushed forward because we've been getting reports of excessive CPU time being spent walking the vmap area rbtree during vm_map_ram operations and this patch supposedly fixes that problem.... Cheers, Dave. -- Dave Chinner david@fromorbit.com _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs