Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753248Ab0H0Hxm (ORCPT ); Fri, 27 Aug 2010 03:53:42 -0400 Received: from tx2ehsobe002.messaging.microsoft.com ([65.55.88.12]:37052 "EHLO TX2EHSOBE004.bigfish.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752349Ab0H0Hxk (ORCPT ); Fri, 27 Aug 2010 03:53:40 -0400 X-SpamScore: 6 X-BigFish: VPS6(z3cfcs329eqzbb2cK1432N98dNzz1202hzzz32i2a8h61h) X-Spam-TCS-SCL: 0:0 X-WSS-ID: 0L7SWHV-02-DG3-02 X-M-MSG: Date: Fri, 27 Aug 2010 09:51:32 +0200 From: Robert Richter To: Don Zickus CC: Ingo Molnar , Peter Zijlstra , Cyrill Gorcunov , Lin Ming , "fweisbec@gmail.com" , "linux-kernel@vger.kernel.org" , "Huang, Ying" , Yinghai Lu , Andi Kleen Subject: Re: [PATCH -v3] perf, x86: try to handle unknown nmis with running perfctrs Message-ID: <20100827075132.GD22783@erda.amd.com> References: <9g472epksbkxhgmw6a3qh8r5.1282316687153@email.android.com> <20100820152510.GA4167@elte.hu> <20100823085339.GA26713@elte.hu> <20100826211424.GQ4879@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Disposition: inline In-Reply-To: <20100826211424.GQ4879@redhat.com> User-Agent: Mutt/1.5.20 (2009-06-14) X-Reverse-DNS: ausb3extmailp02.amd.com Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1178 Lines: 43 On 26.08.10 17:14:24, Don Zickus wrote: > diff --git a/arch/x86/kernel/cpu/perf_event_intel.c b/arch/x86/kernel/cpu/perf_event_intel.c > index 4539b4b..d16ebd8 100644 > --- a/arch/x86/kernel/cpu/perf_event_intel.c > +++ b/arch/x86/kernel/cpu/perf_event_intel.c > @@ -738,6 +738,7 @@ again: > > inc_irq_stat(apic_perf_irqs); > ack = status; > + intel_pmu_ack_status(ack); Yes, not immediately ack'ing the status was suspect to me too. Though it must then be the same counter that retriggers. Or, it is a cpu bug. You could add a debug print of the status register for the case the loop is reentered, would be interesting... Thank for fixing this. -Robert > > intel_pmu_lbr_read(); > > @@ -766,8 +767,6 @@ again: > x86_pmu_stop(event); > } > > - intel_pmu_ack_status(ack); > - > /* > * Repeat if there is more work to be done: > */ > -- Advanced Micro Devices, Inc. Operating System Research Center -- 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/