RE: [RFC PATCH 13/22 -v2] handle accurate time keeping over longdelays

From: Luck, Tony
Date: Thu Jan 10 2008 - 16:36:45 EST


> If you noticed in my email, the fix for ppc was a bit easier, as it has
> only a 64bit counter that is quite unlikely to wrap twice between calls
> to update_wall_time().

"quite unlikely" ...

Hmmm just how fast are you driving the clocks on your ppc? Even at 100GHz
It is almost SIX YEARS between wrap-arounds of a 64-bit counter.
Perhaps you could just have a cron job that forces a call to update_wall_time()
every January 1st, rather than add extra code overhead to a hot path :-) ?

But I agree that narrower counters are a problem.

-Tony
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