From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965216AbWD1OvE (ORCPT ); Fri, 28 Apr 2006 10:51:04 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S965214AbWD1OvD (ORCPT ); Fri, 28 Apr 2006 10:51:03 -0400 Received: from e4.ny.us.ibm.com ([32.97.182.144]:18306 "EHLO e4.ny.us.ibm.com") by vger.kernel.org with ESMTP id S965216AbWD1OvB (ORCPT ); Fri, 28 Apr 2006 10:51:01 -0400 Date: Fri, 28 Apr 2006 10:50:41 -0400 From: Vivek Goyal To: KAMEZAWA Hiroyuki Cc: Andrew Morton , linux-kernel@vger.kernel.org, lhms-devel@lists.sourceforge.net, vgoyal@in.ibm.com, ebiederm@xmission.com, nanhai.zou@intel.com Subject: Re: [Lhms-devel] Re: [PATCH] register hot-added memory to iomem resource Message-ID: <20060428145041.GB7061@in.ibm.com> Reply-To: vgoyal@in.ibm.com References: <20060427204904.5037f6ea.kamezawa.hiroyu@jp.fujitsu.com> <20060427160130.6149550f.akpm@osdl.org> <20060428092754.cf382d03.kamezawa.hiroyu@jp.fujitsu.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20060428092754.cf382d03.kamezawa.hiroyu@jp.fujitsu.com> User-Agent: Mutt/1.5.11 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Apr 28, 2006 at 09:27:54AM +0900, KAMEZAWA Hiroyuki wrote: > On Thu, 27 Apr 2006 16:01:30 -0700 > Andrew Morton wrote: > > > KAMEZAWA Hiroyuki wrote: > > > > > > This patch registers hot-added memory to iomem_resource. > > > By this, /proc/iomem can show hot-added memory. > > > This patch is against 2.6.17-rc2-mm1. > > > > > > Note: kdump uses /proc/iomem to catch memory range when it is installed. > > > So, kdump should be re-installed after /proc/iomem change. > > > > > > > What do you mean by "kdump should be reinstalled"? The kdump userspace > > tools need to re-run kexec_load()? > > > yes. I heard an admin has to re-run kexec_load. > - http://www.uwsg.indiana.edu/hypermail/linux/kernel/0604.0/0821.html > - http://www.uwsg.indiana.edu/hypermail/linux/kernel/0604.0/0829.html > Added CC to ebiederm@xmission.com, nanhai.zou@intel.com > > > If so, why? > > > It reads physical memory list from /proc/iomem now. > The physical memory list is read and saved at kdump kernel loading time > instead of crashing time. > True. If some meory is added, kdump kernel has to be re-loaded. > > And how is kdump to know that memory was hot-added? Do we generate a > > hotplug event? > > > A user program has to make memory section online from sysfs , anyway. > > The hotplug script for memory hotplug will run at memory hotplug event > from ACPI. If a user uses /probe interface (powerpc, x86_64), > he knows what he does. > > hot-add -> online memory -> kexec_load() is a scenario I think of. > I will look into it. Thanks Vivek