Re: 2.6.14-rt13

From: Lee Revell
Date: Fri Nov 18 2005 - 16:58:06 EST


On Fri, 2005-11-18 at 10:02 -0800, Fernando Lopez-Lezcano wrote:
> You mentioned before that the TSC's from both cpus could drift from
> each other over time. Assuming that is the source of timing (I have no
> idea) that could explain the behavior of Jack, it gets a reference
> time from one of the cpus and then compares that with what it gets
> from either cpu depending on where it is running at a given time. If
> it is the same cpu all is fine, if it is the other and it has drifted
> then the warning is printed.

Yes, JACK uses rdtsc() for microsecond resolution timing and assumes
that the TSCs are in sync.

I've asked on this list what a better time source could be and didn't
get any useful responses, people just told me "use gettimeofday()" which
is WAY too slow.

Lee

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