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 pAK8Xojt139078 for ; Sun, 20 Nov 2011 02:33:50 -0600 Received: from ipmail04.adl6.internode.on.net (localhost [127.0.0.1]) by cuda.sgi.com (Spam Firewall) with ESMTP id B2C482659C2 for ; Sun, 20 Nov 2011 00:33:48 -0800 (PST) Received: from ipmail04.adl6.internode.on.net (ipmail04.adl6.internode.on.net [150.101.137.141]) by cuda.sgi.com with ESMTP id aMcYLFQmHQwa9ZrH for ; Sun, 20 Nov 2011 00:33:48 -0800 (PST) Date: Sun, 20 Nov 2011 19:33:45 +1100 From: Dave Chinner Subject: Re: [PATCH] xfs: force buffer writeback before blocking on the ilock in inode reclaim Message-ID: <20111120083345.GO7046@dastard> References: <20111120072334.GA27386@infradead.org> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20111120072334.GA27386@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 Sun, Nov 20, 2011 at 02:23:34AM -0500, Christoph Hellwig wrote: > If we are doing synchronous inode reclaim we block the VM from making > progress in memory reclaim. So if we encouter a flush locked inode > make sure we force out all delayed buffers ASAP to speed up the wait > for it to be unlocked. Without this we can get hangs of up to 30 > seconds during workloads hitting synchronous inode reclaim. I don't think we need to push out all delayed buffers - that's an awfully big sledge hammer to get a single buffer moving. Indeed, we already have a mechanism for dealing with this problem - xfs_buf_delwri_promote() - when we hit it during AIL flushing. IOWs, we only need to promote the buffer the inode sits in and kick xfsbufd. that is, something like: bp = xfs_incore(ip->i_mount->m_ddev_targp, iip->ili_format.ilf_blkno, iip->ili_format.ilf_len, XBF_TRYLOCK); if (bp && XFS_BUF_ISDELAYWRITE(bp)) { xfs_buf_delwri_promote(bp); wake_up_process(mp->m_ddev_targp->bt_task); } if (bp) xfs_buf_relse(bp); Cheers, Dave. -- Dave Chinner david@fromorbit.com _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs