Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1030387AbcCQLyg (ORCPT ); Thu, 17 Mar 2016 07:54:36 -0400 Received: from mail.skyhub.de ([78.46.96.112]:51036 "EHLO mail.skyhub.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1030211AbcCQLye (ORCPT ); Thu, 17 Mar 2016 07:54:34 -0400 Date: Thu, 17 Mar 2016 12:54:06 +0100 From: Borislav Petkov To: Peter Zijlstra Cc: Vince Weaver , mingo@kernel.org, alexander.shishkin@linux.intel.com, eranian@google.com, linux-kernel@vger.kernel.org, dvyukov@google.com, andi@firstfloor.org, jolsa@redhat.com, panand@redhat.com, sasha.levin@oracle.com, oleg@redhat.com Subject: Re: [PATCH 00/12] perf: more fixes Message-ID: <20160317115406.GC28772@pd.tnic> References: <20160224174539.570749654@infradead.org> <20160310143924.GR6356@twins.programming.kicks-ass.net> <20160315153830.GA6356@twins.programming.kicks-ass.net> <20160316225933.GS6375@twins.programming.kicks-ass.net> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20160316225933.GS6375@twins.programming.kicks-ass.net> User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1209 Lines: 37 On Wed, Mar 16, 2016 at 11:59:33PM +0100, Peter Zijlstra wrote: > On Tue, Mar 15, 2016 at 04:38:30PM +0100, Peter Zijlstra wrote: > > > Running perf_fuzzer on that AMD box is still producing lots of fail, I > > seen long strings of dazed and confused msgs, indicating we have a > > 'spurious' NMI problem somewhere. > > > > And occasionally it locks up.. > > > > So we're not there yet. > > So the below appears to alleviate some of this; but the hangs are > quicker now, so maybe I just made it worse. > > --- > Subject: perf, ibs: Fix race with IBS_STARTING state > From: Peter Zijlstra > Date: Wed Mar 16 23:55:21 CET 2016 > > While tracing the IBS bits I saw the NMI hitting between clearing > IBS_STARTING and the actual MSR writes to disable the counter. > > Since IBS_STARTING was cleared, the handler assumed these were spurious > NMIs and because STOPPING wasn't set yet either, insta-triggered an > "Unknown NMI". > > Cure this by clearing IBS_STARTING after disabling the hardware. > > Signed-off-by: Peter Zijlstra (Intel) Tested-by: Borislav Petkov -- Regards/Gruss, Boris. ECO tip #101: Trim your mails when you reply.