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Date: Tue, 3 Jun 2008 16:07:05 +0200 (CEST)
From: "M. Koehrer" <mathias_koehrer@domain.hid>
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Subject: [Xenomai-help] TSCs synchron on multi-core CPUs?
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To: xenomai@xenomai.org

Hi everybody,

I have a question concerning the time stamp counters of the Intel core2duo/=
quad CPUs.
They will be used e.g. with the Xenomai native skin call rt_time_tsc which =
ends up in
an assembler statement "rdtsc".
My question is now:
Are the values of TSC synchron with dual/quad core CPUs? Or is there a poss=
ible drift between
the CPUs?
Background of the question is:
I want to measure the time of a event that occurs within one task.
A second event is checked in another task on a different core. The time dif=
ference between the
events has to be checked.
Can this be done precisely with rdtsc() or is a mechanism required that use=
s the TSC of exactly one=20
core?

Thanks for all hints on that question!

Regards

Mathias

--=20
Mathias Koehrer
mathias_koehrer@domain.hid


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