Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758100Ab3CTQbu (ORCPT ); Wed, 20 Mar 2013 12:31:50 -0400 Received: from mx1.redhat.com ([209.132.183.28]:7930 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752379Ab3CTQbt (ORCPT ); Wed, 20 Mar 2013 12:31:49 -0400 Date: Wed, 20 Mar 2013 12:31:31 -0400 From: Vivek Goyal To: Yinghai Lu Cc: Simon Horman , Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , WANG Chao , "Eric W. Biederman" , linux-kernel@vger.kernel.org Subject: Re: [PATCH v5] x86, kdump: Set crashkernel_low automatically Message-ID: <20130320163131.GE2273@redhat.com> References: <20130319133326.GB3872@redhat.com> <1363705526-3197-1-git-send-email-yinghai@kernel.org> <20130320130855.GB17274@redhat.com> <20130320160327.GD2273@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2228 Lines: 51 On Wed, Mar 20, 2013 at 09:21:31AM -0700, Yinghai Lu wrote: > On Wed, Mar 20, 2013 at 9:03 AM, Vivek Goyal wrote: > > On Wed, Mar 20, 2013 at 08:53:29AM -0700, Yinghai Lu wrote: > >> On Wed, Mar 20, 2013 at 6:08 AM, Vivek Goyal wrote: > >> > >> > Have a general question about crashkernel_low. Why does it need to > >> > show up as "Crash kernel low" in /proc/iomem. Will it not be better > >> > that all memory reserved for crashkernel (whether high or low), shows > >> > as "Crash Kernel" and let kexec-tools decide whether to load kernel > >> > high or low etc. > >> > > >> > IOW, there should not be any need to differentiate between "Crash kernel" > >> > and "Crash kernel low". There are address ranges associated and looking > >> > at addresses it is obivious that certain memory is below 4G. > >> > >> yes. it is doable. > >> but > >> 1. will need to add more code to expand parse_iomem_single to handle > >> multiple "Crash kernel" in kexec-tools. > >> 2. also we already have "crashkernel_low=" in command line, so it is > >> good to keep them consistent in /proc/iomem. > > > > I think command line and /proc/iomem output are very different. > > crashkernel_low is just enforcing that reserve it below 4G and memory > > type still remains "Crash Kernel". > > > > So to me, /proc/iomem is showing ranges and memory type and both the > > memory types should be "Crash Kernel". > > > > IMHO, we should add code in kexec-tools to deal with it (multiple > > entries for memory type "Crash Kernel"), instead of especial casing > > "Crash Kernel Low". Who knows down the line we end up reserving more > > crash kernel memory which is not contiguous. Keeping all reserved > > memory of same type will help then. > > ok. > > Need to fix kexec-tools at first, and the drop Low in kernel. > > Before v3.9 and kexec-tools 2.0.4? I think so. We need to do this in 3.9 otherwise it becomes another backward compatibility issue. Thanks Vivek -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/