From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932385Ab2EVVGE (ORCPT ); Tue, 22 May 2012 17:06:04 -0400 Received: from e06smtp13.uk.ibm.com ([195.75.94.109]:47941 "EHLO e06smtp13.uk.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756306Ab2EVVGB (ORCPT ); Tue, 22 May 2012 17:06:01 -0400 Message-ID: <4FBBFFB5.3010605@de.ibm.com> Date: Tue, 22 May 2012 23:05:57 +0200 From: Christian Borntraeger User-Agent: Mozilla/5.0 (X11; Linux i686; rv:12.0) Gecko/20120430 Thunderbird/12.0.1 MIME-Version: 1.0 To: Avi Kivity , Marcelo Tosatti , KVM list , Linux Kernel Mailing List CC: Oleg Nesterov Subject: qemu core dump and filtering guest pages Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit x-cbid: 12052221-2966-0000-0000-0000042972F0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Folks, today we discussed the situation of a qemu crash (with coredump) and big guests. Quite often the guest pages are not needed but make the core file pretty big. The most appealing proposal that we had was to adopt the core file code in the kernel to have an option for discarding guest pages (e.g. /proc/sys/core_guest). do_corefile would have a callback into the kvm module that could use its memory slot infrastructure to decide if this page should be saved or not. Would you consider such a change be ok? Any better idea? Thanks Christian