mirror of https://lore.kernel.org/lkml/
 help / color / mirror / Atom feed
* clocksource watchdog false detection
@ 2017-01-18  0:47 Yinghai Lu
  2017-01-18  9:14 ` Thomas Gleixner
  0 siblings, 1 reply; 2+ messages in thread
From: Yinghai Lu @ 2017-01-18  0:47 UTC (permalink / raw)
  To: Thomas Gleixner, john stultz; +Cc: Linux Kernel Mailing List

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?

Thanks

Yinghai

^ permalink raw reply	[flat|nested] 2+ messages in thread

* Re: clocksource watchdog false detection
  2017-01-18  0:47 clocksource watchdog false detection Yinghai Lu
@ 2017-01-18  9:14 ` Thomas Gleixner
  0 siblings, 0 replies; 2+ messages in thread
From: Thomas Gleixner @ 2017-01-18  9:14 UTC (permalink / raw)
  To: Yinghai Lu; +Cc: Linux Kernel Mailing List, John Stultz, x86, Peter Zijlstra

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

^ permalink raw reply	[flat|nested] 2+ messages in thread

end of thread, other threads:[~2017-01-18  9:14 UTC | newest]

Thread overview: 2+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2017-01-18  0:47 clocksource watchdog false detection Yinghai Lu
2017-01-18  9:14 ` Thomas Gleixner

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox

all inboxes | Powered by JetHome®