From: "M. Koehrer" <mathias_koehrer@domain.hid>
To: xenomai@xenomai.org
Subject: [Xenomai-help] TSCs synchron on multi-core CPUs?
Date: Tue, 3 Jun 2008 16:07:05 +0200 (CEST) [thread overview]
Message-ID: <18504269.1212502025901.JavaMail.ngmail@domain.hid> (raw)
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 possible 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 difference between the
events has to be checked.
Can this be done precisely with rdtsc() or is a mechanism required that uses the TSC of exactly one
core?
Thanks for all hints on that question!
Regards
Mathias
--
Mathias Koehrer
mathias_koehrer@domain.hid
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next reply other threads:[~2008-06-03 14:07 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-06-03 14:07 M. Koehrer [this message]
2008-06-03 14:29 ` [Xenomai-help] TSCs synchron on multi-core CPUs? Karl Reichert
2008-06-03 16:47 ` Jan Kiszka
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