ÔÚ2009-12-29£¬"Gilles Chanteperdrix" <gilles.chanteperdrix@xenomai.org> дµÀ£º
>robert165 wrote:
>> 
>> 
>> 
>> ÔÚ2009-12-28£¬"Gilles Chanteperdrix" <gilles.chanteperdrix@xenomai.org> дµÀ£º
>>>robert165 wrote:
>>>> Hi,
>>>> I have tested xenomai on my at91rm9200 board, I used
>>>> xenomai 2.4.10 + linux-2.6.28 + adeos-ipipe-2.6.28-arm-1.12-05.patch
>>>> Test result seems very poor, is that correct?
>>>
>>>Your test results are rather good for an at91rm9200 board, which is the
>>>sure sign that you are not loading the system enough.
>>>
>>>As I already told, you, the expected results are:
>>>- user-space latency of 260us without FCSE
>>>- user-space latency of 200us with FCSE
>>>- kernel-space latency of 50us if running with unlocked context switches
>>>(an option which is only available in the upcoming 2.5 branch).
>>>
>>>> And is there any introduction of the tests, as their purper, their
>>>> meanling...
>>>
>>>The latency test computes some latencies (either user-space scheduling
>>>latency, kernel-space scheduling latency, or kernel-space interrupt
>>>latency, depending on the options). The switchtest tests context
>>>switches. The switchbench measures context switching time. cyclictest
>>>does the same thing as the latency test (only, you need to run it with
>>>the right options to avoid running in fact with Linux timer), and in
>>>general return similar results. Here I do not know what is the meaning
>>>of cyclictest results you got, but if you want to know, I am afraid you
>>>wil have to investigate, or simply ignore them.
>>>
>> 
>> Thanks for your introdution, and is there any document of it. 
>> The man pages just explain  parametres  of test scripts.  I could
>> not understand the output of some test.
>
>No there is no document. But patches are welcome, as usual. As far as I
>can tell, I explained you what the tests do, there is not much more to
>tell. Which test's output did you not understand?
>

when running: ./run -- -p 1000 -T 180 -t2 # latency
result gave negative numbers like 
RTH|-----lat min|-----lat avg|-----lat max|-overrun|----lat best|---lat worst
RTD|      -3.739|      11.330|      39.530|       0|      -3.739|      39.530
Is that means timer interrupts are not perfect, and may occur before or after the exact moment.
If so, the avg should calculate by the absolute value of the latency, and the best should be 
the least absolute value.

Thanks again.

Robert