Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752756AbbB0MHy (ORCPT ); Fri, 27 Feb 2015 07:07:54 -0500 Received: from mail.skyhub.de ([78.46.96.112]:36691 "EHLO mail.skyhub.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751899AbbB0MHx (ORCPT ); Fri, 27 Feb 2015 07:07:53 -0500 Date: Fri, 27 Feb 2015 13:06:48 +0100 From: Borislav Petkov To: Prarit Bhargava Cc: Naoya Horiguchi , Tony Luck , Vivek Goyal , "linux-kernel@vger.kernel.org" , Junichi Nomura , Kiyoshi Ueda Subject: Re: [PATCH v2 1/2] x86: mce: kexec: turn off MCE in kexec Message-ID: <20150227120648.GA3337@pd.tnic> References: <1425013116-23581-1-git-send-email-n-horiguchi@ah.jp.nec.com> <54F05080.9090605@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <54F05080.9090605@redhat.com> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1252 Lines: 31 On Fri, Feb 27, 2015 at 06:09:52AM -0500, Prarit Bhargava wrote: > What if the system is actually having problems with MCE errors -- > which are leading to system panics of some sort. Do you *really* want > the system to continue on at that point? No one said that disabling MCA and doing kdump is a 100% reliable thing. When CR4.MCE=0b and an MCE happens, it will shutdown the system, at least on Intel, according to Tony. On AMD, disabling error reporting in addition leads to CR4.MCE being ignored. In any case, disabling MCA contains a risk kdump should be willing to take. Let's ask the reverse question: is kdump prepared to handle an MCE when one happens during dumping? If we have to be really correct, kdump should actually be prepared to handle MCEs and in the case where it cannot recover, stop dumping because the already dumped data might be faulty and corrupted... And print a nasty message on the screen... -- Regards/Gruss, Boris. ECO tip #101: Trim your mails when you reply. -- -- 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/