From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757742Ab2EWIhu (ORCPT ); Wed, 23 May 2012 04:37:50 -0400 Received: from mx1.redhat.com ([209.132.183.28]:26017 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751859Ab2EWIhq (ORCPT ); Wed, 23 May 2012 04:37:46 -0400 Message-ID: <4FBCA1D6.1070905@redhat.com> Date: Wed, 23 May 2012 11:37:42 +0300 From: Avi Kivity User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:12.0) Gecko/20120430 Thunderbird/12.0.1 MIME-Version: 1.0 To: Christian Borntraeger CC: Marcelo Tosatti , KVM list , Linux Kernel Mailing List , Oleg Nesterov Subject: Re: qemu core dump and filtering guest pages References: <4FBBFFB5.3010605@de.ibm.com> In-Reply-To: <4FBBFFB5.3010605@de.ibm.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 05/23/2012 12:05 AM, Christian Borntraeger wrote: > 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? There's MADV_DONTDUMP which can be used to control this on a per-guest basis. -- error compiling committee.c: too many arguments to function