Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760602Ab0KRVRD (ORCPT ); Thu, 18 Nov 2010 16:17:03 -0500 Received: from mx1.redhat.com ([209.132.183.28]:63393 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757237Ab0KRVRB (ORCPT ); Thu, 18 Nov 2010 16:17:01 -0500 Date: Thu, 18 Nov 2010 16:16:38 -0500 From: Don Zickus To: Cyrill Gorcunov Cc: Jason Wessel , Peter Zijlstra , Ingo Molnar , Robert Richter , ying.huang@intel.com, Andi Kleen , LKML , Frederic Weisbecker Subject: Re: [V2 PATCH 0/6] x86, NMI: give NMI handler a face-lift Message-ID: <20101118211638.GA13139@redhat.com> References: <4CE2E3C3.6060800@windriver.com> <20101118080516.GJ32621@elte.hu> <4CE52048.5080802@windriver.com> <1290086232.2109.1507.camel@laptop> <20101118193247.GF18100@redhat.com> <4CE583D0.8050407@windriver.com> <20101118200807.GC8131@redhat.com> <20101118201118.GC6028@lenovo> <20101118205203.GA11445@redhat.com> <20101118210159.GF6028@lenovo> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20101118210159.GF6028@lenovo> User-Agent: Mutt/1.5.20 (2009-08-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1052 Lines: 29 On Fri, Nov 19, 2010 at 12:01:59AM +0300, Cyrill Gorcunov wrote: > On Thu, Nov 18, 2010 at 03:52:03PM -0500, Don Zickus wrote: > ... > > > > > > ok, Don, but you mentioned there are false alarms on real P4 machine, right? > > > > Yeah, there are two problems. One is using kgdb tests on kvm guests. The > > other is using kgdb tests on a bare metal p4 machine. > > > > Cheers, > > Don > > > > ok, thanks, Jason just confirmed it too. I thing if we run with kgdb armed > it (kgdb) should obtain nmi handler first and perf only after. > > actually I'm not sure why p4 hangs here while core passes the test, most because p4 reads the wrong high register which comes back zero. This will always set overflow=1, thus swallowing all NMI if something like the nmi watchdog has perf active. 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/