[Xenomai-help] xenomai and ppc issues

[Xenomai-help] xenomai and ppc issues

[GUARDIOLA-FALCO Sebastien 204282]

Hello,

I'm involved in a real-time project for a PPC mvme2700 target, and I need hard real-time tasks that can be executed in user-space. Seems that only Xenomai can meet the requirements.
My first question is to have confirmation that RTAI or LXRT are x86 based and can not help me.
The second issue is to know how I can install Xenomai (do I need to install Adeos kernel first? which version should I download?) and to know how far Xenomai goes in hard real-time (better preemption latency that RTAI?).

Thanks for your answers.

Sébastien Guardiola Falco.

Re: [Xenomai-help] xenomai and ppc issues

[Jan Kiszka]

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GUARDIOLA-FALCO Sebastien 204282 wrote:
> Hello,
> 
> I'm involved in a real-time project for a PPC mvme2700 target, and I need hard real-time tasks that can be executed in user-space. Seems that only Xenomai can meet the requirements.
> My first question is to have confirmation that RTAI or LXRT are x86 based and can not help me.

RTAI used to support other archs as well, but the situation has changed
AFAIK.

> The second issue is to know how I can install Xenomai (do I need to install Adeos kernel first? which version should I download?)

Start with the latest stable release (2.1.2) and follow README.INSTALL.

> and to know how far Xenomai goes in hard real-time (better preemption latency that RTAI?).

Cannot comment on this as I do not have comparable numbers for PPC. Once
you have 2.1.2 running, check the testsuite (xeno-test script or
individual tests) to get an impression of what is possible. You are
invited to post results here in order to let other PPC user
cross-check/comment (an automated test with online result database is
under development).

Xenomai constantly improves with respect to worst-case latency and
overall performance. Upcoming version 2.2 will introduce, e.g.,
additional optimisations which can reduce user space scheduling
latencies by ~20%. But, of course, the closer your design requirements
get to the benchmark results, the more careful and intensive your
performance analysis of the final system has to be.

Jan


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RE: [Xenomai-help] xenomai and ppc issues

[GUARDIOLA-FALCO Sebastien 204282]

Thanks, I guess the 2.1.2 release works with 2.4 kernel.

I will post PPC results when I have it, for sure.

Regards,

Sébastien.

-----Message d'origine-----
De : jan.kiszka@domain.hid [mailto:jan.kiszka@domain.hid]
Envoyé : jeudi 8 juin 2006 13:24
À : GUARDIOLA-FALCO Sebastien 204282
Cc : xenomai@xenomai.org
Objet : Re: [Xenomai-help] xenomai and ppc issues


GUARDIOLA-FALCO Sebastien 204282 wrote:
> Hello,
> 
> I'm involved in a real-time project for a PPC mvme2700 target, and I need hard real-time tasks that can be executed in user-space. Seems that only Xenomai can meet the requirements.
> My first question is to have confirmation that RTAI or LXRT are x86 based and can not help me.

RTAI used to support other archs as well, but the situation has changed
AFAIK.

> The second issue is to know how I can install Xenomai (do I need to install Adeos kernel first? which version should I download?)

Start with the latest stable release (2.1.2) and follow README.INSTALL.

> and to know how far Xenomai goes in hard real-time (better preemption latency that RTAI?).

Cannot comment on this as I do not have comparable numbers for PPC. Once
you have 2.1.2 running, check the testsuite (xeno-test script or
individual tests) to get an impression of what is possible. You are
invited to post results here in order to let other PPC user
cross-check/comment (an automated test with online result database is
under development).

Xenomai constantly improves with respect to worst-case latency and
overall performance. Upcoming version 2.2 will introduce, e.g.,
additional optimisations which can reduce user space scheduling
latencies by ~20%. But, of course, the closer your design requirements
get to the benchmark results, the more careful and intensive your
performance analysis of the final system has to be.

Jan