Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755963Ab0HPTNa (ORCPT ); Mon, 16 Aug 2010 15:13:30 -0400 Received: from bombadil.infradead.org ([18.85.46.34]:39732 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755621Ab0HPTN3 convert rfc822-to-8bit (ORCPT ); Mon, 16 Aug 2010 15:13:29 -0400 Subject: Re: [PATCH -v2] perf, x86: try to handle unknown nmis with running perfctrs From: Peter Zijlstra To: Cyrill Gorcunov Cc: Robert Richter , Don Zickus , Lin Ming , Ingo Molnar , "fweisbec@gmail.com" , "linux-kernel@vger.kernel.org" , "Huang, Ying" , Yinghai Lu , Andi Kleen In-Reply-To: <20100816190659.GI5805@lenovo> References: <20100804163930.GE5130@lenovo> <20100804184806.GL26154@erda.amd.com> <20100804192634.GG5130@lenovo> <20100806065203.GR26154@erda.amd.com> <20100806142131.GA1874@redhat.com> <20100809194829.GB26154@erda.amd.com> <20100811220058.GT26154@erda.amd.com> <1281970116.1926.1495.camel@laptop> <20100816162706.GH5805@lenovo> <20100816171610.GN26154@erda.amd.com> <20100816190659.GI5805@lenovo> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8BIT Date: Mon, 16 Aug 2010 21:13:16 +0200 Message-ID: <1281985996.1926.1848.camel@laptop> Mime-Version: 1.0 X-Mailer: Evolution 2.28.3 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 620 Lines: 13 On Mon, 2010-08-16 at 23:06 +0400, Cyrill Gorcunov wrote: > I never heard of backward running tsc, though tsc is a strange beast. > Its not supposed to happen, but then there's BIOS failure-add that frobs the TSC from SMIs and fun TSC artifacts around CPU frequency changes and people resetting TSC in S-states etc.. In short, never trust the TSC to be even remotely sane. -- 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/