From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751959AbcF3J5G (ORCPT ); Thu, 30 Jun 2016 05:57:06 -0400 Received: from mail.skyhub.de ([78.46.96.112]:36400 "EHLO mail.skyhub.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751223AbcF3J5E (ORCPT ); Thu, 30 Jun 2016 05:57:04 -0400 Date: Thu, 30 Jun 2016 11:49:19 +0200 From: Borislav Petkov To: Thomas Gleixner Cc: Peter Zijlstra , x86-ml , lkml Subject: Re: rc5+tip/master: Marking clocksource 'tsc' as unstable because the skew is too large: Message-ID: <20160630094919.GB17833@pd.tnic> References: <20160627200631.GA3678@pd.tnic> <20160629171619.GA3691@pd.tnic> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Jun 30, 2016 at 10:40:47AM +0200, Thomas Gleixner wrote: > On Wed, 29 Jun 2016, Borislav Petkov wrote: > > On Mon, Jun 27, 2016 at 10:06:31PM +0200, Borislav Petkov wrote: > > > Hey Thomas, > > > > > > Just started seeing this now during testing of Rafael's s/r fix: > > > > > > [ 24.973955] clocksource: timekeeping watchdog on CPU3: Marking clocksource 'tsc' as unstable because the skew is too large: > > > [ 24.987744] clocksource: 'acpi_pm' wd_now: 2df835 wd_last: a6bb64 mask: ffffff > > > [ 24.999587] clocksource: 'tsc' cs_now: 2bbe793d1e cs_last: 296e28763c mask: ffffffffffffffff > > > [ 25.013400] clocksource: Switched to clocksource acpi_pm > > > > > > In the previous boot it was CPU1. > > > > And here it is again: > > > > ... > > [ 15.720833] IPv6: ADDRCONF(NETDEV_CHANGE): eth0: link becomes ready > > [ 32.883077] clocksource: timekeeping watchdog on CPU1: Marking clocksource 'tsc' as unstable because the skew is too large: > > [ 32.896986] clocksource: 'acpi_pm' wd_now: 8e147 wd_last: 531b43 mask: ffffff > > [ 32.908834] clocksource: 'tsc' cs_now: 385f4b6d1e cs_last: 354328bcea mask: ffffffffffffffff > > [ 32.922293] clocksource: Switched to clocksource acpi_pm > > What's the tsc freqeuency on your machine? $ dmesg | grep -i tsc [ 0.000000] tsc: Fast TSC calibration using PIT [ 0.000000] tsc: Detected 4013.406 MHz processor [ 5.034357] tsc: Refined TSC clocksource calibration: 4013.511 MHz [ 5.034359] clocksource: tsc: mask: 0xffffffffffffffff max_cycles: 0x39da38233dd, max_idle_ns: 440795253361 ns [ 6.068153] clocksource: Switched to clocksource tsc [ 32.883077] clocksource: timekeeping watchdog on CPU1: Marking clocksource 'tsc' as unstable because the skew is too large: [ 32.908834] clocksource: 'tsc' cs_now: 385f4b6d1e cs_last: 354328bcea mask: ffffffffffffffff P0 is 4Ghz and TSC is ticking at P0 so 4GHz too. 4-ish, it seems :) -- Regards/Gruss, Boris. ECO tip #101: Trim your mails when you reply.