From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Fri, 1 Feb 2008 17:35:28 -0600 From: Robin Holt Subject: Re: [patch 2/4] mmu_notifier: Callbacks to invalidate address ranges Message-ID: <20080201233528.GE12099@sgi.com> References: <20080201050439.009441434@sgi.com> <20080201050623.344041545@sgi.com> <20080201220952.GA3875@sgi.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: owner-linux-mm@kvack.org Return-Path: To: Christoph Lameter Cc: Robin Holt , Andrea Arcangeli , Avi Kivity , Izik Eidus , kvm-devel@lists.sourceforge.net, Peter Zijlstra , steiner@sgi.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org, daniel.blueman@quadrics.com List-ID: On Fri, Feb 01, 2008 at 03:19:32PM -0800, Christoph Lameter wrote: > On Fri, 1 Feb 2008, Robin Holt wrote: > > > We are getting this callout when we transition the pte from a read-only > > to read-write. Jack and I can not see a reason we would need that > > callout. It is causing problems for xpmem in that a write fault goes > > to get_user_pages which gets back to do_wp_page that does the callout. > > Right. You placed it there in the first place. So we can drop the code > from do_wp_page? No, we need a callout when we are becoming more restrictive, but not when becoming more permissive. I would have to guess that is the case for any of these callouts. It is for both GRU and XPMEM. I would expect the same is true for KVM, but would like a ruling from Andrea on that. Thanks, Robin -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org