From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:55322) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1asX35-0006HM-Oy for qemu-devel@nongnu.org; Tue, 19 Apr 2016 10:54:44 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1asX32-0004DS-JZ for qemu-devel@nongnu.org; Tue, 19 Apr 2016 10:54:43 -0400 Received: from mx1.redhat.com ([209.132.183.28]:52805) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1asX32-0004D8-6F for qemu-devel@nongnu.org; Tue, 19 Apr 2016 10:54:40 -0400 Message-ID: <1461077659.3200.8.camel@redhat.com> From: Rik van Riel 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> Content-Type: text/plain; charset="UTF-8" Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH kernel 1/2] mm: add the related functions to build the free page bitmap List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , 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 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?