From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755671Ab0IJQhv (ORCPT ); Fri, 10 Sep 2010 12:37:51 -0400 Received: from mx2.mail.elte.hu ([157.181.151.9]:48154 "EHLO mx2.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755587Ab0IJQhu (ORCPT ); Fri, 10 Sep 2010 12:37:50 -0400 Date: Fri, 10 Sep 2010 18:37:27 +0200 From: Ingo Molnar To: Robert Richter Cc: Don Zickus , Peter Zijlstra , "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" Subject: Re: [PATCH 0/3 v2] nmi perf fixes Message-ID: <20100910163727.GB10036@elte.hu> References: <1283454469-1909-1-git-send-email-dzickus@redhat.com> <1284118900.402.35.camel@laptop> <20100910132741.GB4879@redhat.com> <20100910144634.GA1060@elte.hu> <20100910151735.GC13563@erda.amd.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20100910151735.GC13563@erda.amd.com> User-Agent: Mutt/1.5.20 (2009-08-17) X-ELTE-SpamScore: -2.0 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-2.0 required=5.9 tests=BAYES_00 autolearn=no SpamAssassin version=3.2.5 -2.0 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 * Robert Richter wrote: > On 10.09.10 10:46:34, Ingo Molnar wrote: > > > > * Don Zickus wrote: > > > > > On Fri, Sep 10, 2010 at 01:41:40PM +0200, Peter Zijlstra wrote: > > > > On Thu, 2010-09-02 at 15:07 -0400, Don Zickus wrote: > > > > > Fixes to allow unknown nmis to pass through the perf nmi handler instead > > > > > of being swallowed. Contains patches that are already in Ingo's tree. Added > > > > > here for completeness. Based on ingo/tip > > > > > > > > > > Tested on intel/amd > > > > > > > > > > v2: patch cleanups and consolidation, no code changes > > > > > > > > > > Don Zickus (1): > > > > > perf, x86: Fix accidentally ack'ing a second event on intel perf > > > > > counter > > > > > > > > > > Peter Zijlstra (1): > > > > > perf, x86: Fix handle_irq return values > > > > > > > > > > Robert Richter (1): > > > > > perf, x86: Try to handle unknown nmis with an enabled PMU > > > > > > > > > > arch/x86/kernel/cpu/perf_event.c | 59 +++++++++++++++++++++++++------- > > > > > arch/x86/kernel/cpu/perf_event_intel.c | 15 +++++--- > > > > > arch/x86/kernel/cpu/perf_event_p4.c | 2 +- > > > > > 3 files changed, 56 insertions(+), 20 deletions(-) > > > > > > > > Both Ingo and I are getting Dazed and confused on our AMD machines, it > > > > started before yesterday (that is, after backing out all my recent > > > > changes it still gets dazed), so I suspect this set. > > > > > > > > I'll look at getting a trace of the thing, but if any of you has a > > > > bright idea... > > > > > > What are you running to create the problem? I can try and duplicate > > > it here. > > > > It happens easily here - just running something like: > > > > perf record -g ./hackbench 10 > > I try to reproduce it, which systems are affected? This is an older Barcelona box, will send you a dump of details off-list. > > a couple of times triggers it. Note, unlike with the earlier bug, > > the NMIs are not permanently 'stuck' - and everything continues > > working. Obviously the messages are nasty looking so this is a > > regression we need to fix. > > The patch below adds ratelimits. This doesnt solve things though - even one unnecessary message will confuse users. Ingo