Re: rc5+tip/master: Marking clocksource 'tsc' as unstable because the skew is too large:

From: Thomas Gleixner
Date: Thu Jun 30 2016 - 04:43:57 EST


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?