From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from relay.sgi.com (relay1.corp.sgi.com [137.38.102.111]) by oss.sgi.com (Postfix) with ESMTP id CA1DB7F3F for ; Mon, 23 Sep 2013 19:48:21 -0500 (CDT) Received: from cuda.sgi.com (cuda2.sgi.com [192.48.176.25]) by relay1.corp.sgi.com (Postfix) with ESMTP id B93768F8049 for ; Mon, 23 Sep 2013 17:48:18 -0700 (PDT) Received: from ipmail06.adl6.internode.on.net (ipmail06.adl6.internode.on.net [150.101.137.145]) by cuda.sgi.com with ESMTP id BLdrvZiiUlMK1SSK for ; Mon, 23 Sep 2013 17:48:14 -0700 (PDT) Date: Tue, 24 Sep 2013 10:48:03 +1000 From: Dave Chinner Subject: Re: [PATCH] [RFC] xfs: lookaside cache for xfs_buf_find Message-ID: <20130924004803.GZ9901@dastard> References: <1378690396-15792-1-git-send-email-david@fromorbit.com> <52404D7F.1080308@sgi.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <52404D7F.1080308@sgi.com> 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 Errors-To: xfs-bounces@oss.sgi.com Sender: xfs-bounces@oss.sgi.com To: Mark Tinguely Cc: xfs@oss.sgi.com On Mon, Sep 23, 2013 at 09:17:35AM -0500, Mark Tinguely wrote: > On 09/08/13 20:33, Dave Chinner wrote: > >From: Dave Chinner > > > >CPU overhead of buffer lookups dominate most metadata intensive > >workloads. The thing is, most such workloads are hitting a > >relatively small number of buffers repeatedly, and so caching > >recently hit buffers is a good idea. > > > ... > > I think this needs more testing. Yes, that's what an "RFC" implies. It's an idea, it's not fully baked and it's not ready for inclusion - it's a proof of concept that needs further work, and I't being posted for discussion to determine if it's worth pursuing further. Indeed, I haven't proposed it for inclusion yet because I'm still finding problems caused by the patch - it's still just a prototype at this point. > I got the same panic running xfstest 319 with the patch at: > http://oss.sgi.com/archives/xfs/2013-09/msg00578.html > once it hung on a xfs_buf lock before the panic. > > And these are the only tests that I threw at this patch. Sure. The version I have in my stack at the moment has some more ixes in it, like handling of length mismatches due to stale buffers on lookaside lookups, and other such things. i.e. early feedback on prototype code is exactly what [RFC] patches are for... Cheers, Dave. -- Dave Chinner david@fromorbit.com _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs