Re: [Bug #12667] Badness at kernel/time/timekeeping.c:98 in pmud(timekeeping_suspended)

From: Thomas Gleixner
Date: Thu Feb 19 2009 - 15:18:16 EST


On Thu, 19 Feb 2009, Benjamin Herrenschmidt wrote:

> On Thu, 2009-02-19 at 21:27 +1300, Paul Collins wrote:
> > > Just for laughs I slapped together the following, which seems to do
> > the
> > > job, although not especially tidily.
> >
> > And it doesn't even do the job. Judging by this new trace, submitting
> > input events from the via-pmu resume function is still too early.
> >
> What's up Thomas ? We can't call gettimeofday() from a sysdev
> suspend/resume ? That's a little bit too harsh no ?

Well, harsh or not is not the question here.

Fact is that you call gettimeofday() _before_ the timekeeping code has
resumed.

That's a simple ordering problem. timekeeping is in the sysdev class
as well and it's not the only sysdev which has explicit ordering
requirements.

Thanks,

tglx
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