From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751682AbdARJOK (ORCPT ); Wed, 18 Jan 2017 04:14:10 -0500 Received: from Galois.linutronix.de ([146.0.238.70]:47851 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751266AbdARJOI (ORCPT ); Wed, 18 Jan 2017 04:14:08 -0500 Date: Wed, 18 Jan 2017 10:14:06 +0100 (CET) From: Thomas Gleixner To: Yinghai Lu cc: Linux Kernel Mailing List , John Stultz , x86@kernel.org, Peter Zijlstra Subject: Re: clocksource watchdog false detection In-Reply-To: Message-ID: References: User-Agent: Alpine 2.20 (DEB 67 2015-01-07) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 17 Jan 2017, Yinghai Lu wrote: > one socket system with running cpu/memory stress test, got: > > -- > [45477.565642] timekeeping watchdog: Marking clocksource 'tsc' as > unstable, because the skew is too large: > [45477.565643] 'acpi_pm' wd_now: 32e642 wd_last: 71c8c5 mask: ffffff > [45477.565644] 'tsc' cs_now: 4b80842681e0 cs_last: 4a48ac7d5a0a > mask: ffffffffffffffff > [45477.623779] Switched to clocksource acpi_pm > > so acpi_pm reading between two timer are wrapped. > > When that happen, should just disable clocksource_watchdog instead? When that happens then something prevented the expiry of the watchdog timer for more than 4.5 seconds. So instead of blaming the messenger, you should fix that problem. Thanks, tglx