On Fri, Jul 22, 2016 at 08:50:44AM -0400, Chris Metcalf wrote:

On 7/21/2016 10:20 PM, Christoph Lameter wrote:

quoted

On Thu, 21 Jul 2016, Chris Metcalf wrote:

quoted

On 7/20/2016 10:04 PM, Christoph Lameter wrote:
unstable, and then scheduling work to safely remove that timer.
I haven't looked at this code before (in kernel/time/clocksource.c
under CONFIG_CLOCKSOURCE_WATCHDOG) since the timers on
arm64 and tile aren't unstable.  Is it possible to boot your machine
with a stable clocksource?

It already as a stable clocksource. Sorry but that was one of the criteria
for the server when we ordered them. Could this be clock adjustments?

We probably need to get clock folks to jump in on this thread!

Boot with: tsc=reliable, this disables the watchdog.

We (sadly) have to have this thing running on most x86 because TSC, even
if initially stable, can do weird things once its running.

We have seen:

 - SMI
 - hotplug
 - suspend
 - multi-socket

mess up the TSC, even if it was deemed 'good' at boot time.

If you _know_ your TSC to be solid, boot with tsc=reliable and be happy.