From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S938417AbdD0F1n (ORCPT ); Thu, 27 Apr 2017 01:27:43 -0400 Received: from mout.gmx.net ([212.227.17.22]:59647 "EHLO mout.gmx.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932371AbdD0F1f (ORCPT ); Thu, 27 Apr 2017 01:27:35 -0400 Message-ID: <1493270815.4154.18.camel@gmx.de> Subject: Re: x86-tip tsc/tick gripage From: Mike Galbraith To: Peter Zijlstra Cc: Ingo Molnar , "Paul E. McKenney" , LKML , Ingo Molnar , Thomas Gleixner , Frederic Weisbecker Date: Thu, 27 Apr 2017 07:26:55 +0200 In-Reply-To: <1493209836.21594.29.camel@gmx.de> References: <1493193739.4412.30.camel@gmx.de> <1493194602.21594.4.camel@gmx.de> <20170426082137.koj7q3ftfqw3o22u@gmail.com> <1493195514.21594.5.camel@gmx.de> <1493197062.21594.8.camel@gmx.de> <20170426102617.l62cdn4gs4h5i4fw@hirez.programming.kicks-ass.net> <1493206789.21594.25.camel@gmx.de> <1493209836.21594.29.camel@gmx.de> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.16.5 Mime-Version: 1.0 Content-Transfer-Encoding: 7bit X-Provags-ID: V03:K0:FtpSaFM6nnP0i5DpeJBOdSsojdLKW8gzdQxmmxSV1pYfPvBGZ3m 2jgQvdvmxaQioR/l3H080I8MwO6cStNLPyBItYMXioXpeU3WON8nLdyvmznqmjAHQk8pyf5 pMBCX7MVGS0ou/jr+j/1wwi8/TaeUHTjfXWw3Jrn8/NpwMxLPRTjfoIitmWbIUWdVZU6gPl h8UvHLE4YiEmsT/LYEXZg== X-UI-Out-Filterresults: notjunk:1;V01:K0:6LYUHarPWRI=:g4RosIAVfvD/y5R/C/aSyC qXc3ecYLS3lnBX2dLsflU92+dRe3ZqwExENNfHgQ79xbnBCFkjOOLj4fZZzk1t9JyXwSxT2IC jncIBBs340K4IW8oMase9EGKfOGNQm5XKsmpPfp56ENyF8rM/NQ/dv+Ozv3igf3VH8KR6kI2N 25KckCpBwytMhN73mHNErqI/52qfo3xm4ycgmo5hf33jajy900tmDqtrlgUMObpJ/oSQZSq5Q sP0De2yR4iMtJBt6xTQqV+y6cVLHeDijX9U0bzK3iTmWHinyHcoeyKSX6T6No391MgwH0Xvfk foggx37EITCNJ5G2zheK33ceVGe5jmuLvitgU9R/KMYVklG0xLWHITIKRckwwqBC2n2O23JOa t7Ym2vB7MDqG25BSzrBnJrpegpSgCYO65ifNR/WhdCMpEhgdMOWqre4SB+4Id4QQpP6uNAV2u VSXmeoIjn8UoxeKsmtIfmStifM5QVpNS2++m6VmikZ05ffzsVhkkOz7EUpaYo9OTH9XD9Pykl YwPemwYMK4PiFAIA57Dw1kXYnVcHsWj/41QhTSwxfgASJjlxopH7n9NrfWeJybjBeOFS1VbW9 X79afdNcGs3EhGbIMtO1410F7X8mbfKMWLBjGMc43L8JPLBAAQ8ODb4xjcwO9i7I2dUBzJi0U 6R8eM8QtfuDBIfgEZOrw/NDa8ztqPMs2mi2a+Y2l9hV47Nbx0UvPtWf7wtpcQxYjb0Jq7u7gQ mQJ/PW+0+LQThXnonSVcb768PRIKSt/24sXLMmIkx4AG3L7FB1obf5ZyTeqFMJ0GyIBGf6f1T C/ajvB2 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 2017-04-26 at 14:30 +0200, Mike Galbraith wrote: > On Wed, 2017-04-26 at 13:39 +0200, Mike Galbraith wrote: > > On Wed, 2017-04-26 at 12:26 +0200, Peter Zijlstra wrote: > > > On Wed, Apr 26, 2017 at 10:57:42AM +0200, Mike Galbraith wrote: > > > > > > > Both still lose their TSC. > > > > > > > > [ 11.982468] tsc: Refined TSC clocksource calibration: 2260.999 MHz > > > > [ 11.994275] clocksource: tsc: mask: 0xffffffffffffffff max_cycles: 0x20974a4d8bb, max_idle_ns: 440795246623 ns > > > > [ 13.064172] clocksource: Switched to clocksource tsc > > > > [ 240.247851] clocksource: timekeeping watchdog on CPU23: Marking clocksource 'tsc' as unstable because the skew is too large: > > > > [ 240.462501] clocksource: 'tsc' cs_now: 108fe5be09f cs_last: b90a6a0676 mask: ffffffffffffffff > > > > [ 240.675057] tsc: Marking TSC unstable due to clocksource watchdog > > > > > > > > > And they didn't use to? We don't typically write to TSC or TSC_ADJUST > > > and thus would not cause such behaviour. > > > > Nope. > > DL980 seems perfectly happy with master.today.. so off we go. hm, this bit of huge trace looks less than wonderful. -0 [041] ..s2 317.304657: timer_expire_entry: timer=ffffffff820d6600 function=clocksource_watchdog now=4294971392 -0 [041] d.s4 317.304660: timer_start: timer=ffffffff820d6600 function=clocksource_watchdog expires=4294916631 [timeout=-54761] cpu=42 idx=19 flags= -0 [041] ..s2 317.304660: timer_expire_exit: timer=ffffffff820d6600 ^^^^^^^^^^^^^^ 1.1 megalines later, we finally meet function=clocksource_watchdog again, and have a cow. -0 [043] d.s3 489.511620: timer_cancel: timer=ffffffff820d6600 -0 [043] ..s2 489.511621: timer_expire_entry: timer=ffffffff820d6600 function=clocksource_watchdog now=4295014443 -0 [043] ..s2 489.511628: clocksource_watchdog: timekeeping watchdog on CPU43: Marking clocksource 'tsc' as unstable because the skew is too large: -0 [043] ..s2 489.511630: clocksource_watchdog: 'hpet' wd_now: a1cbfa1a wd_last: ed7acfe mask: ffffffff -0 [043] ..s2 489.511630: clocksource_watchdog: 'tsc' cs_now: 1c24ee60f22 cs_last: 167a92e836f mask: ffffffffffffffff