[Linux-users] the system clock stopped?!?

[Lonni J Friedman]

On 9/5/07, Lonni J Friedman <netllama at gmail.com> wrote:
> On 9/5/07, C M Reinehr <cmr at amsent.com> wrote:
> > On Tuesday 04 September 2007 14:31, Lonni J Friedman wrote:
> > > To return to this thread, i'm now seeing this same problem on a
> > > *second* system running Fedora 7 (x86).  So this is most definitely
> > > not a hardware problem.  The 2nd system does not have the same
> > > motherboard as the 1st, so its not even a motherboard specific
> > > problem.  The only commonality between the two systems is that they
> > > both have AMD CPUs, however one system is dual core, the other is not.
> > >
> > > Again, this problem only seems to happen if the system is sitting idle
> > > (like over the past 3 day weekend).  Beyond that, I can't find any way
> > > to deterministically trigger the behavior.  Surely, I can't be in some
> > > weird Bermuda triangle where my systems hit this weirdness?
> >
> >         A couple of passing thoughts:
> >
> > 1) Are you running ntp? If not, try running it & then check the ntp logs to
> > see what they indicate.
>
> Yes, i'm running ntp, however once the system gets into this weird
> state, nothing works properly any longer, including ntp.  ntp just
> never does anything at all (it hangs indefinitely, likely trying to
> update against a clock that isn't updating).
>
> >
> > 2) Do you have any powersaving features enabled? If so, perhaps, one is
> > shutting down something it shouldn't. (You can see how much I know about
> > this!)
>
> No, i have all powersaving disabled.
>
> At this point, I'm blindly guessing that this might be due to some
> tickless kernel bug.  I've booted with nohz=off and i'll see if that
> has any impact (likely after the upcoming weekend).

booting with nohz=off definitely fixed this.  Its clearly a bug in the
tickless kernel.


-- 
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
L. Friedman                                    netllama at gmail.com
LlamaLand                       https://netllama.linux-sxs.org