Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753388AbXJOE0S (ORCPT ); Mon, 15 Oct 2007 00:26:18 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1750859AbXJOE0F (ORCPT ); Mon, 15 Oct 2007 00:26:05 -0400 Received: from netops-testserver-3-out.sgi.com ([192.48.171.28]:37785 "EHLO relay.sgi.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1750775AbXJOE0E (ORCPT ); Mon, 15 Oct 2007 00:26:04 -0400 Date: Mon, 15 Oct 2007 14:25:46 +1000 From: David Chinner To: Jeremy Fitzhardinge Cc: David Chinner , Nick Piggin , xfs@oss.sgi.com, Xen-devel , Linux Kernel Mailing List , Mark Williamson , Morten =?iso-8859-1?Q?B=F8geskov?= , xfs-masters@oss.sgi.com Subject: Re: Interaction between Xen and XFS: stray RW mappings Message-ID: <20071015042546.GI995458@sgi.com> References: <470FA7C3.90404@goop.org> <200710151415.07248.nickpiggin@yahoo.com.au> <4712BB05.1020701@goop.org> <200710151726.08387.nickpiggin@yahoo.com.au> <4712E1AA.501@goop.org> <20071015041133.GH995458@sgi.com> <4712EA09.6000102@goop.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4712EA09.6000102@goop.org> User-Agent: Mutt/1.4.2.1i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1015 Lines: 26 On Sun, Oct 14, 2007 at 09:18:17PM -0700, Jeremy Fitzhardinge wrote: > David Chinner wrote: > > With defaults - little effect as vmap should never be used. It's > > only when you start using larger block sizes for metadata that this > > becomes an issue. The CONFIG_XEN workaround should be fine until we > > get a proper vmap cache.... > > Hm, well I saw the problem with a filesystem made with mkfs.xfs with no > options, so there must be at least *some* vmapping going on there. Sorry - I should have been more precise - vmap should never be used in performance critical paths on default configs. Log recovery will trigger vmap/vunmap usage, so this is probably what you are seeing. Cheers, Dave. -- Dave Chinner Principal Engineer SGI Australian Software Group - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/