From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail137.messagelabs.com (mail137.messagelabs.com [216.82.249.19]) by kanga.kvack.org (Postfix) with ESMTP id D9B636B008A for ; Sat, 25 Dec 2010 10:24:06 -0500 (EST) From: Seiji Aguchi Date: Sat, 25 Dec 2010 09:56:50 -0500 Subject: RE: [RFC][PATCH] Add a sysctl option controlling kexec when MCE occurred Message-ID: <5C4C569E8A4B9B42A84A977CF070A35B2C132F6CFA@USINDEVS01.corp.hds.com> References: <5C4C569E8A4B9B42A84A977CF070A35B2C132F68FC@USINDEVS01.corp.hds.com> <20101223091851.GC30055@liondog.tnic> <5C4C569E8A4B9B42A84A977CF070A35B2C132F6BB0@USINDEVS01.corp.hds.com> In-Reply-To: Content-Language: en-US Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Sender: owner-linux-mm@kvack.org To: "Eric W. Biederman" Cc: Borislav Petkov , Andi Kleen , "rdunlap@xenotime.net" , "tglx@linutronix.de" , "mingo@redhat.com" , "hpa@zytor.com" , "x86@kernel.org" , "akpm@linuxfoundation.org" , "eugeneteo@kernel.org" , "kees.cook@canonical.com" , "drosenberg@vsecurity.com" , "ying.huang@intel.com" , "len.brown@intel.com" , "seto.hidetoshi@jp.fujitsu.com" , "paulmck@linux.vnet.ibm.com" , "gregkh@suse.de" , "davem@davemloft.net" , "hadi@cyberus.ca" , "hawk@comx.dk" , "opurdila@ixiacom.com" , "hidave.darkstar@gmail.com" , "dzickus@redhat.com" , "eric.dumazet@gmail.com" , "ext-andriy.shevchenko@nokia.com" , "tj@kernel.org" , "linux-doc@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "kexec@lists.infradead.org" , "linux-mm@kvack.org" , "dle-develop@lists.sourceforge.net" , Satoru Moriya List-ID: Hi, Thank you for giving your comments. >So what is the problem you are trying to avoid, and why can't we do >something in the kernels initialization path to avoid initializing >when there is a problem? Kdump gets a dump disk identifier based on information from memory. So, kdump may receive wrong identifier when it starts after MCE=20 occurred, because MCE is reported by memory, cache, and TLB errors In the worst case, kdump will overwrite user data if it recognizes a=20 disk saving user data as a dump disk. Kdump shouldn't write any data to disk when information from hardware is incredible because saving user data is always first=20 priority. Seiji -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom policy in Canada: sign http://dissolvethecrtc.ca/ Don't email: email@kvack.org