Re: [Xenomai-help] Perfs and rt alarms questions.

[Gilles Chanteperdrix <gilles.chanteperdrix@xenomai.org>]

RAKOTOSALAMA, Nirilanto wrote:
> 
>>>Hello everybody.
>>>
>>>I managed to compile a stable kernel (the Scalability O(1) 
>>
>>scheduler options seems to make my system freeze)
>>
>>That's not good. What precisely did you do? Applied the .config you
>>posted, just enabling CONFIG_XENO_OPT_SCALABLE_SCHED? And what test
>>case, latency?
> 
> 
> 
> I both tested a configuration with CONFIG_XENO_OPT_SCALABLE_SCHED enabled and an other disabled.
> When I enable and when I launch the cyclictest, the system hard lock and the 2 left keyboard leds blink.
> When I let it disabled the system is stable.
> 
> 
> 
>>>xenomai 2.3.1 and vanilla 2.6.20.4, gcc 4.1.1 on FC6.
>>>
>>>I'm programming and testing a xenomai support for a timer 
>>
>>library using rt_alarm. The test program
>>
>>>lauches the timer periodically and calculate the precision 
>>
>>(difference between theoretical and practical results).
>>
>>>When I launch the latency test, the max latency I have 
>>
>>doesn't exceed 10us. So I supposed the precision shouldn't 
>>
>>Using what load for the system? Keep in mind that unloaded benchmark
>>numbers are practically meaningless.
>>
>>
>>>exceed 10 to 20us as well, No ? But sometimes, the 
>>
>>precision exceed 30 to 60us. Is it normal ?
>>
>>Depending on your hardware (CPU, chipset, peripherals), this 
>>can be very
>>well a worst-case latency of the loaded system. Try to capture such a
>>result with the tracer 
> 
> 
> I've tested latency with loaded system (lot of applications loaded, dd, cp, tar, find /)and have a max latency of 339us.
> But I don't understand anything in the frozen trace file.

You likely have either an issue with SMI, or with X-window. Read the
TROUBLESHOOTING file.


-- 
                                                 Gilles Chanteperdrix