Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757979Ab3CTQVd (ORCPT ); Wed, 20 Mar 2013 12:21:33 -0400 Received: from mail-ie0-f178.google.com ([209.85.223.178]:56734 "EHLO mail-ie0-f178.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753605Ab3CTQVc (ORCPT ); Wed, 20 Mar 2013 12:21:32 -0400 MIME-Version: 1.0 In-Reply-To: <20130320160327.GD2273@redhat.com> References: <20130319133326.GB3872@redhat.com> <1363705526-3197-1-git-send-email-yinghai@kernel.org> <20130320130855.GB17274@redhat.com> <20130320160327.GD2273@redhat.com> Date: Wed, 20 Mar 2013 09:21:31 -0700 X-Google-Sender-Auth: vc6IXjluH14Bv_dk7pd3qJkJvR0 Message-ID: Subject: Re: [PATCH v5] x86, kdump: Set crashkernel_low automatically From: Yinghai Lu To: Vivek Goyal , Simon Horman Cc: Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , WANG Chao , "Eric W. Biederman" , linux-kernel@vger.kernel.org Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1995 Lines: 48 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? Thanks Yinghai -- 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/