Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753104Ab0HZJCI (ORCPT ); Thu, 26 Aug 2010 05:02:08 -0400 Received: from tx2ehsobe003.messaging.microsoft.com ([65.55.88.13]:57396 "EHLO TX2EHSOBE005.bigfish.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753254Ab0HZJCG (ORCPT ); Thu, 26 Aug 2010 05:02:06 -0400 X-SpamScore: 6 X-BigFish: VPS6(z3cfcs329eqzbb2cK1432N98dNzz1202hzzz32i2a8h61h) X-Spam-TCS-SCL: 0:0 X-WSS-ID: 0L7R507-01-AYS-02 X-M-MSG: Date: Thu, 26 Aug 2010 11:00:08 +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: <20100826090008.GA22783@erda.amd.com> References: <9g472epksbkxhgmw6a3qh8r5.1282316687153@email.android.com> <20100820152510.GA4167@elte.hu> <20100825094819.GB3198@erda.amd.com> <20100825104130.GA27891@elte.hu> <20100825110006.GB27891@elte.hu> <20100825201106.GH4879@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Disposition: inline In-Reply-To: <20100825201106.GH4879@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: 2332 Lines: 41 On 25.08.10 16:11:06, Don Zickus wrote: > > cpu #15, nmi #160, marked #0, handled = 1, time = 333392635730, delta = 11238255 > > cpu #15, nmi #161, marked #0, handled = 1, time = 333403779380, delta = 11143650 > > cpu #15, nmi #162, marked #0, handled = 1, time = 333415418497, delta = 11639117 > > cpu #15, nmi #163, marked #0, handled = 1, time = 333415467084, delta = 48587 > > cpu #15, nmi #164, marked #0, handled = 1, time = 333415501531, delta = 34447 > > cpu #15, nmi #165, marked #0, handled = 1, time = 333459918106, delta = 44416575 > > cpu #15, nmi #166, marked #0, handled = 0, time = 333459923167, delta = 1666 > > cpu #15, nmi #151, marked #0, handled = 1, time = 332978597882, delta = 11447002 > > cpu #15, nmi #152, marked #0, handled = 1, time = 332978657151, delta = 59269 > > cpu #15, nmi #153, marked #0, handled = 1, time = 332978667847, delta = 10696 > > cpu #15, nmi #154, marked #0, handled = 1, time = 333023125757, delta = 44457910 > > cpu #15, nmi #155, marked #0, handled = 1, time = 333291980833, delta = 268855076 > > cpu #15, nmi #156, marked #0, handled = 1, time = 333325663125, delta = 33682292 > > cpu #15, nmi #157, marked #0, handled = 1, time = 333348216481, delta = 22553356 > > cpu #15, nmi #158, marked #0, handled = 1, time = 333370168887, delta = 21952406 > > cpu #15, nmi #159, marked #0, handled = 1, time = 333381397475, delta = 11228588 > > Uhhuh. NMI received for unknown reason 00 on CPU 15. > > Do you have a strange power saving mode enabled? > > Dazed and confused, but trying to continue > > So I found a Nehalem box that can reliably reproduce Ingo's problem using > something as simple 'perf top'. But like above, I am noticing the > samething, an extra NMI(PMI??) that comes out of nowhere. This could also be a race in the counter handling code, or we do not proper count the number of handled counters. Maybe 2 counters actually fired but we only noticed one counter and then accidentially cleared the 2nd without processing it. -Robert -- 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/