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 n7QHtCJr027885 for ; Wed, 26 Aug 2009 12:55:27 -0500 Received: from bombadil.infradead.org (localhost [127.0.0.1]) by cuda.sgi.com (Spam Firewall) with ESMTP id 475BB3FF54A for ; Wed, 26 Aug 2009 10:56:05 -0700 (PDT) Received: from bombadil.infradead.org (bombadil.infradead.org [18.85.46.34]) by cuda.sgi.com with ESMTP id Qp91SMsFwnCuVEOM for ; Wed, 26 Aug 2009 10:56:05 -0700 (PDT) Date: Wed, 26 Aug 2009 13:56:04 -0400 From: Christoph Hellwig Subject: Re: disk performance strange/low Message-ID: <20090826175603.GA14019@infradead.org> References: <200908172311.07660@zmi.at> <200908180408.10738@zmi.at> <20090818024350.GA3591@infradead.org> <200908261920.47054@zmi.at> MIME-Version: 1.0 Content-Type: multipart/mixed; boundary="a8Wt8u1KmwUX3Y2C" Content-Disposition: inline In-Reply-To: <200908261920.47054@zmi.at> List-Id: XFS Filesystem from SGI List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: xfs-bounces@oss.sgi.com Errors-To: xfs-bounces@oss.sgi.com To: Michael Monnerie Cc: xfs@oss.sgi.com --a8Wt8u1KmwUX3Y2C Content-Type: text/plain; charset=us-ascii Content-Disposition: inline On Wed, Aug 26, 2009 at 07:20:36PM +0200, Michael Monnerie wrote: > On Dienstag 18 August 2009 Christoph Hellwig wrote: > > On Tue, Aug 18, 2009 at 04:08:05AM +0200, Michael Monnerie wrote: > > > On Montag 17 August 2009 Christoph Hellwig wrote: > > > > Yes, that sounds like the problem of the VM not feeding us enough > > > > pages to write. ?What kernel is this on? ?Latest 2.6.31-rc has a > > > > workaround for it. > > > > > > 2.6.27.23-0.1-xen from openSUSE 11.1 > > > I can't switch as I use it with the free Xen. Thanks for the info. > > > > Try backporting commit c8a4051c3731b6db224482218cfd535ab9393ff8 from > > mainline - it should apply just fine to a 2.6.27-ish kernel. > > Thank you. I'm not a patcher, could you tell me how to do that? Just take the patch I attached and apply it using patch -p1 < xfs-nr-to-write.diff if you want to make sure it applies cleanly do a patch -p1 --dry-run < xfs-nr-to-write.diff beforee to check if it doesn't cause any reject. After that rebuild your kernel. --a8Wt8u1KmwUX3Y2C Content-Type: text/plain; charset=us-ascii Content-Disposition: attachment; filename="xfs-nr-to-write.diff" commit c8a4051c3731b6db224482218cfd535ab9393ff8 Author: Eric Sandeen Date: Fri Jul 31 00:02:17 2009 -0500 xfs: bump up nr_to_write in xfs_vm_writepage VM calculation for nr_to_write seems off. Bump it way up, this gets simple streaming writes zippy again. To be reviewed again after Jens' writeback changes. Signed-off-by: Christoph Hellwig Signed-off-by: Eric Sandeen Cc: Chris Mason Reviewed-by: Felix Blyakher Signed-off-by: Felix Blyakher diff --git a/fs/xfs/linux-2.6/xfs_aops.c b/fs/xfs/linux-2.6/xfs_aops.c index 7ec89fc..aecf251 100644 --- a/fs/xfs/linux-2.6/xfs_aops.c +++ b/fs/xfs/linux-2.6/xfs_aops.c @@ -1268,6 +1268,14 @@ xfs_vm_writepage( if (!page_has_buffers(page)) create_empty_buffers(page, 1 << inode->i_blkbits, 0); + + /* + * VM calculation for nr_to_write seems off. Bump it way + * up, this gets simple streaming writes zippy again. + * To be reviewed again after Jens' writeback changes. + */ + wbc->nr_to_write *= 4; + /* * Convert delayed allocate, unwritten or unmapped space * to real space and flush out to disk. --a8Wt8u1KmwUX3Y2C Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Disposition: inline _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs --a8Wt8u1KmwUX3Y2C--