From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755409Ab0IPRmq (ORCPT ); Thu, 16 Sep 2010 13:42:46 -0400 Received: from casper.infradead.org ([85.118.1.10]:59612 "EHLO casper.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753381Ab0IPRmp convert rfc822-to-8bit (ORCPT ); Thu, 16 Sep 2010 13:42:45 -0400 Subject: Re: [PATCH] x86: fix duplicate calls of the nmi handler From: Peter Zijlstra To: Robert Richter Cc: Ingo Molnar , Don Zickus , "gorcunov@gmail.com" , "fweisbec@gmail.com" , "linux-kernel@vger.kernel.org" , "ying.huang@intel.com" , "ming.m.lin@intel.com" , "yinghai@kernel.org" , "andi@firstfloor.org" , "eranian@google.com" In-Reply-To: <20100910155659.GD13563@erda.amd.com> References: <1283454469-1909-1-git-send-email-dzickus@redhat.com> <1284118900.402.35.camel@laptop> <20100910132741.GB4879@redhat.com> <20100910144634.GA1060@elte.hu> <20100910155659.GD13563@erda.amd.com> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8BIT Date: Thu, 16 Sep 2010 19:42:30 +0200 Message-ID: <1284658950.2275.591.camel@laptop> Mime-Version: 1.0 X-Mailer: Evolution 2.28.3 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 2010-09-10 at 17:56 +0200, Robert Richter wrote: > The commit: > > e40b172 x86: Move notify_die from nmi.c to traps.c > > moved the nmi handler call to default_do_nmi(). DIE_NMI_IPI and > DIE_NMI are called subsequently now. If the return code is > !NOTIFY_STOP, then the handlers are called twice. This patch fixes > this. What is this NMI_IPI thing, and why do we bother? If the hardware reason thin can discriminate between IPI and other NMIs we should never call both chains, if it cannot, why do we have 2 chains? In any case, I don't think perf/oprofile/etc,. should use NMI_IPI, that doesn't really make sense. Or am I totally confused about things here?