From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1030277AbWGZACb (ORCPT ); Tue, 25 Jul 2006 20:02:31 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1030279AbWGZACb (ORCPT ); Tue, 25 Jul 2006 20:02:31 -0400 Received: from mx1.redhat.com ([66.187.233.31]:29072 "EHLO mx1.redhat.com") by vger.kernel.org with ESMTP id S1030277AbWGZACb (ORCPT ); Tue, 25 Jul 2006 20:02:31 -0400 Message-ID: <44C6B111.9010502@redhat.com> Date: Tue, 25 Jul 2006 20:02:25 -0400 From: Rik van Riel Organization: Red Hat, Inc User-Agent: Thunderbird 1.5.0.4 (X11/20060614) MIME-Version: 1.0 To: Christoph Lameter CC: Peter Zijlstra , linux-mm , linux-kernel Subject: Re: [PATCH] mm: inactive-clean list References: <1153167857.31891.78.camel@lappy> <44C30E33.2090402@redhat.com> <44C518D6.3090606@redhat.com> <44C68F0E.2050100@redhat.com> In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Christoph Lameter wrote: > On Tue, 25 Jul 2006, Rik van Riel wrote: > >>> An increment of a VM counter causes a state change in the hypervisor? >> Christoph, please read more than the first 5 words in each >> email before replying. > > Well, I read the whole thing before I replied and I could not figure this > one out. Maybe I am too dumb to understand. Could you please explain > yourself in more detail Page state transitions can be very expensive in a virtualized environment, so it would be good if we had fewer transitions. > I am also not sure why I should be running a hypervisor in the first place > and so I may not be up to date on the whole technology. You may not, but IMHO it would be good if whatever new VM things we implement in Linux would at least be virtualization friendly. Especially if that can be achieved without hurting native performance... -- "Debugging is twice as hard as writing the code in the first place. Therefore, if you write the code as cleverly as possible, you are, by definition, not smart enough to debug it." - Brian W. Kernighan