From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754863AbZHTQjH (ORCPT ); Thu, 20 Aug 2009 12:39:07 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754329AbZHTQjG (ORCPT ); Thu, 20 Aug 2009 12:39:06 -0400 Received: from claw.goop.org ([74.207.240.146]:36661 "EHLO claw.goop.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751461AbZHTQjE (ORCPT ); Thu, 20 Aug 2009 12:39:04 -0400 Message-ID: <4A8D7C26.5020902@goop.org> Date: Thu, 20 Aug 2009 09:39:02 -0700 From: Jeremy Fitzhardinge User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.1.1) Gecko/20090814 Fedora/3.0-2.6.b3.fc11 Lightning/1.0pre Thunderbird/3.0b3 MIME-Version: 1.0 To: Miroslav Rezanina CC: linux-kernel@vger.kernel.org, xen-devel@lists.xensource.com, Gianluca Guida Subject: Re: [PATCH][v2.6.29][XEN] Return unused memory to hypervisor References: <2039875032.3531250754474167.JavaMail.root@zmail06.collab.prod.int.phx2.redhat.com> In-Reply-To: <2039875032.3531250754474167.JavaMail.root@zmail06.collab.prod.int.phx2.redhat.com> X-Enigmail-Version: 0.97a Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 08/20/09 00:47, Miroslav Rezanina wrote: > there is handled e820 map in guest. However, this patch informs > hypervisor, that guest uses less memory than was assigned to it. > If hypervisor is not informed, memory is reserved for guest that > do not need it. If hypervisor is informed, he decrease memory > reservation for guest and unused memory is marked as free > for use by other guests. > Yes. But the guest will modify its own e820 map for a number of reasons; for example: reducing its own memory, or clearing a space for the PCI hole. In general we want to free any underlying pages which don't correspond to E820_RAM regions. J