Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752612AbYKKVz7 (ORCPT ); Tue, 11 Nov 2008 16:55:59 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751057AbYKKVzt (ORCPT ); Tue, 11 Nov 2008 16:55:49 -0500 Received: from mx2.redhat.com ([66.187.237.31]:49898 "EHLO mx2.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750938AbYKKVzs (ORCPT ); Tue, 11 Nov 2008 16:55:48 -0500 Message-ID: <4919FF41.30800@qumranet.com> Date: Tue, 11 Nov 2008 23:55:13 +0200 From: Izik Eidus User-Agent: Thunderbird 2.0.0.17 (X11/20081009) MIME-Version: 1.0 To: Christoph Lameter CC: Avi Kivity , Andrea Arcangeli , Andrew Morton , Izik Eidus , linux-kernel@vger.kernel.org, linux-mm@kvack.org, kvm@vger.kernel.org, chrisw@redhat.com, izike@qumranet.com Subject: Re: [PATCH 2/4] Add replace_page(), change the mapping of pte from one page into another References: <1226409701-14831-1-git-send-email-ieidus@redhat.com> <1226409701-14831-2-git-send-email-ieidus@redhat.com> <1226409701-14831-3-git-send-email-ieidus@redhat.com> <20081111114555.eb808843.akpm@linux-foundation.org> <20081111210655.GG10818@random.random> <4919FB95.4060105@redhat.com> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1039 Lines: 29 Christoph Lameter wrote: > On Tue, 11 Nov 2008, Avi Kivity wrote: > > >> Christoph Lameter wrote: >> >>> page migration requires the page to be on the LRU. That could be changed >>> if you have a different means of isolating a page from its page tables. >>> >>> >> Isn't rmap the means of isolating a page from its page tables? I guess I'm >> misunderstanding something. >> > > In order to migrate a page one first has to make sure that userspace and > the kernel cannot access the page in any way. User space must be made to > generate page faults and all kernel references must be accounted for and > not be in use. > This is really not the case for ksm, in ksm we allow the page to be accessed all the time, we dont have to swap the page like migrate.c is doing... -- 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/