Re: 'Detected 19943xxx Hz processor'-fluctuations...

Robert Woodcock (rcw@debian.org)
Wed, 13 Jan 1999 19:40:41 -0800


On Wed, Jan 13, 1999 at 08:32:00AM +0100, Florian Weimer wrote:
> Robert Woodcock <rcw@debian.org> writes:
> > PPro, but that's irrelevant.
>
> Are you sure?

Of course not :)

> AFAIK, gettimeofday() internally uses rdtsc() on those processors.

Hmm, I just checked 2.0.36 as well as 2.2.0-pre source and both read from
the TSC for do_fast_gettimeoffset, which is the guts of do_gettimeofday.

> Aren't you trying to measure the precision of a clock with the same
> clock?

No wonder it was working so well :>

Anyone wanna fill me in on how well it works with a kernel compiled to
use do_slow_gettimeoffset?

-- 
Robert Woodcock - rcw@debian.org
"Unix and C are the ultimate computer viruses" -- Richard Gabriel

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