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 pA8NBLHB161944 for ; Tue, 8 Nov 2011 17:11:22 -0600 Received: from ipmail06.adl2.internode.on.net (localhost [127.0.0.1]) by cuda.sgi.com (Spam Firewall) with ESMTP id 5FCDC1CF6A6A for ; Tue, 8 Nov 2011 15:11:20 -0800 (PST) Received: from ipmail06.adl2.internode.on.net (ipmail06.adl2.internode.on.net [150.101.137.129]) by cuda.sgi.com with ESMTP id Khkqihxizpy3ouiL for ; Tue, 08 Nov 2011 15:11:20 -0800 (PST) Date: Wed, 9 Nov 2011 10:11:18 +1100 From: Dave Chinner Subject: Re: [PATCH 2/5] xfs: use per-filesystem I/O completion workqueues Message-ID: <20111108231118.GP5534@dastard> References: <20111108085614.478431403@bombadil.infradead.org> <20111108085846.291838677@bombadil.infradead.org> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20111108085846.291838677@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: xfs@oss.sgi.com On Tue, Nov 08, 2011 at 03:56:16AM -0500, Christoph Hellwig wrote: > The new concurrency managed workqueues are cheap enough that we can create > per-filesystem instead of global workqueues. This allows us to remove the > trylock or defer scheme on the ilock, which has the potential of delaying > size updates, and is not helpful once we start to log the inode size. So why does the per-mount workqueues allow removal of the trylock? IOWs, it might be worthwhile pointing to the commit (77d7a0c "xfs: Non-blocking inode locking in IO completion") to indicate that the functionality being removed was introduced to avoid IO completion deadlocks between dependent filesystems (e.g. XFS on loop device on XFS) and that moving to per-mount completion queues removes that dependency.... Cheers, Dave. -- Dave Chinner david@fromorbit.com _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs