Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932384AbcDSOyl (ORCPT ); Tue, 19 Apr 2016 10:54:41 -0400 Received: from mx1.redhat.com ([209.132.183.28]:53841 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754742AbcDSOyj (ORCPT ); Tue, 19 Apr 2016 10:54:39 -0400 Message-ID: <1461077659.3200.8.camel@redhat.com> Subject: Re: [PATCH kernel 1/2] mm: add the related functions to build the free page bitmap From: Rik van Riel To: Liang Li , mst@redhat.com, viro@zeniv.linux.org.uk, linux-kernel@vger.kernel.org, quintela@redhat.com, amit.shah@redhat.com, pbonzini@redhat.com, dgilbert@redhat.com Cc: linux-mm@kvack.org, kvm@vger.kernel.org, qemu-devel@nongnu.org, agraf@suse.de, borntraeger@de.ibm.com Date: Tue, 19 Apr 2016 10:54:19 -0400 In-Reply-To: <1461076474-3864-2-git-send-email-liang.z.li@intel.com> References: <1461076474-3864-1-git-send-email-liang.z.li@intel.com> <1461076474-3864-2-git-send-email-liang.z.li@intel.com> Organization: Red Hat, Inc. Content-Type: text/plain; charset="UTF-8" Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 451 Lines: 11 On Tue, 2016-04-19 at 22:34 +0800, Liang Li wrote: > The free page bitmap will be sent to QEMU through virtio interface > and used for live migration optimization. > Drop the cache before building the free page bitmap can get more > free pages. Whether dropping the cache is decided by user. > How do you prevent the guest from using those recently-freed pages for something else, between when you build the bitmap and the live migration completes?