From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from cuda.sgi.com (cuda1.sgi.com [192.48.157.11]) by oss.sgi.com (8.14.3/8.14.3/SuSE Linux 0.8) with ESMTP id oBLLemnh096907 for ; Tue, 21 Dec 2010 15:40:48 -0600 Received: from mail.internode.on.net (localhost [127.0.0.1]) by cuda.sgi.com (Spam Firewall) with ESMTP id 3DF6F1472734 for ; Tue, 21 Dec 2010 13:42:43 -0800 (PST) Received: from mail.internode.on.net (bld-mail16.adl2.internode.on.net [150.101.137.101]) by cuda.sgi.com with ESMTP id SHdJ1Fk1nSzMKGQz for ; Tue, 21 Dec 2010 13:42:43 -0800 (PST) Date: Wed, 22 Dec 2010 08:42:40 +1100 From: Dave Chinner Subject: Re: [PATCH 06/34] xfs: dynamic speculative EOF preallocation Message-ID: <20101221214240.GB4907@dastard> References: <1292916570-25015-1-git-send-email-david@fromorbit.com> <1292916570-25015-7-git-send-email-david@fromorbit.com> <20101221151511.GA26127@infradead.org> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20101221151511.GA26127@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, Dec 21, 2010 at 10:15:11AM -0500, Christoph Hellwig wrote: > This patch causes tesr 014 to take ~ 870 seconds instead of 6, thus > beeing almost 150 times slower on mt 32-bit test VM, so I'll have to NAK > it for now. It's not the speculative preallocation changes - ithey are just exposing some other regression. That is, using MOUNT_OPTIONS="-o allocsize=4k" gives the previous behaviour, while allocsize=512m gives the same behaviour as the dynamic preallocation. The dynamic behaviour is resulting in megabyte sized IOs being issued for random 512 byte writes (which is wrong), so I'm tending towards it being a regression caused by the reecent writeback path changes. I'll dig deeper today. Cheers, Dave. -- Dave Chinner david@fromorbit.com _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs