Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752691AbZGBHx3 (ORCPT ); Thu, 2 Jul 2009 03:53:29 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751736AbZGBHxU (ORCPT ); Thu, 2 Jul 2009 03:53:20 -0400 Received: from mx2.mail.elte.hu ([157.181.151.9]:55340 "EHLO mx2.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751622AbZGBHxT (ORCPT ); Thu, 2 Jul 2009 03:53:19 -0400 Date: Thu, 2 Jul 2009 09:53:05 +0200 From: Ingo Molnar To: "Maciej W. Rozycki" , Borislav Petkov Cc: Greg KH , x86@kernel.org, "H. Peter Anvin" , Thomas Gleixner , Kurt Garloff , linux-kernel@vger.kernel.org, Yinghai Lu , Jesse Barnes Subject: Re: [PATCH] x86: sysctl to allow panic on IOCK NMI error Message-ID: <20090702075305.GC19187@elte.hu> References: <20090624213211.GA11291@kroah.com> <20090630223040.GA3802@suse.de> <20090701111003.GC15958@elte.hu> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.18 (2008-05-17) X-ELTE-SpamScore: -1.5 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-1.5 required=5.9 tests=BAYES_00 autolearn=no SpamAssassin version=3.2.5 -1.5 BAYES_00 BODY: Bayesian spam probability is 0 to 1% [score: 0.0000] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1489 Lines: 38 * Maciej W. Rozycki wrote: > On Wed, 1 Jul 2009, Ingo Molnar wrote: > > > > ENOTIME, sorry. Next year perhaps. Or a homework project > > > for one of the newbies. ;) > > > > You know that this project would kill a newbie, right? :) > > Well, that's just a fast track to become a veteran, isn't it? ;) No, that's just a fast track to quickly make it into the list of our Fallen Heroes :-/ The fast track to become a kernel veteran is to, if possible, not challenge a tank with a hand-grenade. But i digress. > > We have no real southbridge drivers on x86 - but we should > > certainly add some. Also, walking the PCI device tree from NMI > > context is tricky as the lists there are not NMI safe - we could > > crash if we happen to get a #IOCK while loading/unloading > > drivers (which is rare but could happen). > > That shouldn't be a problem if we were about to panic(). For a > more sophisticated attempt of recovery -- yes, that would have to > be addressed. We are only panic-ing if the sysctl is set. The diagnostics would be useful anyway. The proper approach would be to defer it a bit in the non-panic case an read it out from some friendlier context - such as the EDAC core. Ingo -- 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/