Re: [PATCH 3/8] x86/apic: allow use of lapic timer early calibration result

H. Peter Anvin
2010-05-11T20:51:54Z

On 05/11/2010 01:46 PM, Pan, Jacob jun wrote:
>
> The question I have is the reference clock used for calibrating those local timers,
> PIT, HPET, PM timer how should they be ranked. Can we make those known freq
> clocksource devices available at this point so that we can use the clocksource
> abstraction and its ranking automatically?
>

Personally I'd rank the PMTMR first, then HPET, then PIT, just based on
the relative complexity and relative known bugginess of the various
implementations.

The PMTMRs main defect is that it can't generate an interrupt; it's just
a dumb counter.

-hpa

--
H. Peter Anvin, Intel Open Source Technology Center
I work for Intel. I don't speak on their behalf.