Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754090Ab0HZPeS (ORCPT ); Thu, 26 Aug 2010 11:34:18 -0400 Received: from mail-ey0-f174.google.com ([209.85.215.174]:35426 "EHLO mail-ey0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754073Ab0HZPeM (ORCPT ); Thu, 26 Aug 2010 11:34:12 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=date:from:to:cc:subject:message-id:references:mime-version :content-type:content-disposition:in-reply-to:user-agent; b=c8C1CkJT6+Yc9683miT6nd154rRIeEYmt1YsrXOGieXEL2HM0AOR/XsPgHG7kxPeu9 /dUPKvvwWhHfxgSz+6ludAP5j4TVCaYpDmkVO1gqKuEV0X118wc7MfpiqZIsKHpeWeQc 17Xix66LX6tQA3F+Wk13yuSfHfRNKhmfuLx8g= Date: Thu, 26 Aug 2010 19:34:04 +0400 From: Cyrill Gorcunov To: Don Zickus Cc: Robert Richter , Ingo Molnar , Peter Zijlstra , 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: <20100826153404.GA6306@lenovo> 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> <20100826090008.GA22783@erda.amd.com> <20100826152246.GN4879@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20100826152246.GN4879@redhat.com> User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1390 Lines: 39 On Thu, Aug 26, 2010 at 11:22:46AM -0400, Don Zickus wrote: > On Thu, Aug 26, 2010 at 01:18:29PM +0400, Cyrill Gorcunov wrote: > > On Thu, Aug 26, 2010 at 1:00 PM, Robert Richter wrote: > > ... > > > > > > 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 > > > > > > > Any chance to get it tested on P4 machine since it has a bit > > different design? > > Hmm, I take that back. I guess I can reproduce this on my i5 that I had > using Ingo's config. > > Working on Robert's assumption, I added code to perf_event_intel.c that > said if handled !=0 just add one to it (IOW always process handled as 0 or > something >1). That seems to working good and catches the nmis that Ingo > was seeing. > > I'll keep looking for the race condition to better fix it. > > Cheers, > Don > Sounds promising, mind to post new inter-diff? Ie what you have changed from Robert's patch. -- Cyrill -- 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/