Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759478Ab1EMQAy (ORCPT ); Fri, 13 May 2011 12:00:54 -0400 Received: from mx1.redhat.com ([209.132.183.28]:65253 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754116Ab1EMQAx (ORCPT ); Fri, 13 May 2011 12:00:53 -0400 Date: Fri, 13 May 2011 12:00:29 -0400 From: Don Zickus To: Ingo Molnar Cc: huang ying , Huang Ying , linux-kernel@vger.kernel.org, Andi Kleen , Robert Richter , Andi Kleen , Borislav Petkov Subject: Re: [RFC] x86, NMI, Treat unknown NMI as hardware error Message-ID: <20110513160029.GD31888@redhat.com> References: <1305275018-20596-1-git-send-email-ying.huang@intel.com> <20110513124523.GM13984@redhat.com> <20110513130011.GA6474@elte.hu> <20110513152033.GB3854@elte.hu> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20110513152033.GB3854@elte.hu> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1585 Lines: 39 On Fri, May 13, 2011 at 05:20:33PM +0200, Ingo Molnar wrote: > > * huang ying wrote: > > > > What should be done instead is to add an event for unknown NMIs, which can > > > then be processed by the RAS daemon to implement policy. > > > > > > By using 'active' event filters it could even be set on a system to panic > > > the box by default. > > > > If there is real fatal hardware error, maybe we have no luxury to go from NMI > > handler to user space RAS daemon to determine what to do. System may explode, > > bad data may go to disk before that. > > That is why i suggested: > > > > By using 'active' event filters it could even be set on a system to panic > > > the box by default. > > event filters are evaluated in the kernel, so the panic could be instantaneous, > without the event having to reach user-space. Interesting. Question though, what do you mean by 'event filtering'. Is that different then setting 'unknown_nmi_panic' panic on the commandline or procfs? Or are you suggesting something like registering another callback on the die_chain that looks for DIE_NMIUNKNOWN as the event, swallows them and implements the policy? That way only on HEST related platforms would register them while others would keep the default of 'Dazed and confused' messages? Cheers, Don -- 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/