Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751175Ab1ECHXg (ORCPT ); Tue, 3 May 2011 03:23:36 -0400 Received: from s15228384.onlinehome-server.info ([87.106.30.177]:42461 "EHLO mail.x86-64.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750907Ab1ECHXe (ORCPT ); Tue, 3 May 2011 03:23:34 -0400 Date: Tue, 3 May 2011 09:23:02 +0200 From: Borislav Petkov To: Ingo Molnar Cc: Peter Zijlstra , Arnaldo Carvalho de Melo , Steven Rostedt , Frederic Weisbecker , Tony Luck , Mauro Carvalho Chehab , EDAC devel , LKML , "Petkov, Borislav" Subject: Re: [PATCH 4/4] x86, mce: Have MCE persistent event off by default for now Message-ID: <20110503072302.GC18979@aftab> References: <1304357691-14354-1-git-send-email-bp@amd64.org> <1304357691-14354-5-git-send-email-bp@amd64.org> <20110503064505.GF7751@elte.hu> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20110503064505.GF7751@elte.hu> User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2000 Lines: 50 On Tue, May 03, 2011 at 02:45:05AM -0400, Ingo Molnar wrote: > > * Borislav Petkov wrote: > > > From: Borislav Petkov > > > > This is new functionality and it affects all of x86 so we want to be > > very conservative about it and have it off by default for now, in case > > something goes awry. You can always enable it by supplying "ras" on the > > kernel command line. > > > > Also, depending on whether it is enabled or not, we emit the tracepoint > > from a different place in the code to pick up additional decoded info. > > > > Signed-off-by: Borislav Petkov > > --- > > Documentation/kernel-parameters.txt | 2 ++ > > arch/x86/include/asm/mce.h | 1 + > > arch/x86/kernel/cpu/mcheck/mce.c | 32 ++++++++++++++++++++++++++++++-- > > drivers/edac/mce_amd.c | 5 +++++ > > 4 files changed, 38 insertions(+), 2 deletions(-) > > the boot flag is fine - but please keep it enabled by default if MCE support is > enabled in the .config, we do not chicken out when it comes to testing new > code! :-) Ok, the problem I see with it is that people without a RAS daemon running will have the mechanism collecting MCEs in the background, using up resources (4 pages per CPU is the buffer) and not doing anything (in the best case that is, when we're not broken otherwise). Do we want to have that on all x86 turned on by default? Or maybe invert the flag semantics so that people can disable it on boot? Thanks. -- Regards/Gruss, Boris. Advanced Micro Devices GmbH Einsteinring 24, 85609 Dornach General Managers: Alberto Bozzo, Andrew Bowd Registration: Dornach, Gemeinde Aschheim, Landkreis Muenchen Registergericht Muenchen, HRB Nr. 43632 -- 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/