[Xenomai] OMAP L138

Peter Howard pjh at northern-ridge.com.au
Wed Apr 9 01:30:56 CEST 2014


On Tue, 2014-04-08 at 11:18 +0200, Gilles Chanteperdrix wrote:
> On 04/07/2014 07:34 AM, Peter Howard wrote:
> > 
> > On Wed, 2014-04-02 at 09:24 +0200, Gilles Chanteperdrix wrote:
> >> On 04/02/2014 04:59 AM, Peter Howard wrote:
> >>> Hi,
> >>>
> >>> I'm interested in running xenomai on a TI-OMAP L138 board.  I found the
> >>> following thread in the archives:
> >>>
> >>> http://www.xenomai.org/pipermail/xenomai/2010-January/018898.html
> >>>
> >>> where someone was working on porting ipipe and xenomai to that board.
> >>> However, the thread ended with problems still unresolved, and the patch
> >>> in the thread (just the changes for ipipe) isn't in the ipipe
> >>> repository.
> >>>
> >>> Does anyone know if this work was completed or just faded into the
> >>> ether?
> >>
> >> We never merged a patch for this processor. And a lot of things changed
> >> since that time. If you are interested in porting the I-pipe patch to
> >> this processor, see:
> >>
> >> http://www.xenomai.org/index.php/I-pipe-core:ArmPorting
> >>
> > 
> > Contrary to what I said last week, I'm working on a patch off the head
> > of the ipipe repo.  I have built a kernel with an ipipe port and with
> > xenomai patched in.  However the latency results are bad right now:
> > 
> > root at arago:~# xeno latency -T 25
> > == Sampling period: 1000 us
> > == Test mode: periodic user-mode task
> > == All results in microseconds
> > warming up...
> > RTT|  00:00:01  (periodic user-mode task, 1000 us period, priority 99)
> > RTH|----lat min|----lat avg|----lat max|-overrun|---msw|---lat best|--lat worst
> > RTD|      3.541|      8.833|     60.749|       0|     0|      3.541|     60.749
> > RTD|      3.499|     13.583|     93.916|       0|     0|      3.499|     93.916
> > RTD|      3.666|     88.999|    109.708|       0|     0|      3.499|    109.708
> > RTD|      3.541|     14.958|     95.374|       0|     0|      3.499|    109.708
> > RTD|      3.541|      9.333|     77.583|       0|     0|      3.499|    109.708
> > RTD|      4.041|     88.416|    109.791|       0|     0|      3.499|    109.791
> > RTD|      3.499|      8.958|     72.791|       0|     0|      3.499|    109.791
> > RTD|      3.499|     26.041|    106.874|       0|     0|      3.499|    109.791
> > RTD|      3.874|     82.708|    107.916|       0|     0|      3.499|    109.791
> > RTD|      3.499|      9.083|     73.708|       0|     0|      3.499|    109.791
> > RTD|      3.333|      8.874|     62.458|       0|     0|      3.333|    109.791
> > RTD|      3.333|      8.749|     62.208|       0|     0|      3.333|    109.791 
> > RTD|      3.416|     12.708|     99.416|       0|     0|      3.333|    109.791 
> > RTD|      3.499|     14.249|    106.749|       0|     0|      3.333|    109.791 
> > RTD|      3.541|      9.083|     76.499|       0|     0|      3.333|    109.791 
> > RTD|      3.249|      8.791|     63.499|       0|     0|      3.249|    109.791 
> > RTD|      3.416|      8.999|     62.499|       0|     0|      3.249|    109.791 
> > RTD|      3.541|     26.166|    101.208|       0|     0|      3.249|    109.791 
> > RTD|      3.583|     13.624|     92.458|       0|     0|      3.249|    109.791 
> > RTD|      3.541|      8.916|     73.708|       0|     0|      3.249|    109.791 
> > RTD|      3.541|      8.999|     64.291|       0|     0|      3.249|    109.791 
> > RTT|  00:00:22  (periodic user-mode task, 1000 us period, priority 99)          
> > RTH|----lat min|----lat avg|----lat max|-overrun|---msw|---lat best|--lat worst 
> > RTD|      3.499|      8.874|     61.374|       0|     0|      3.249|    109.791 
> > RTD|      3.499|     13.833|    100.749|       0|     0|      3.249|    109.791 
> > RTD|      3.541|     13.083|     99.249|       0|     0|      3.249|    109.791 
> > ---|-----------|-----------|-----------|--------|------|------------------------
> > RTS|      3.249|     21.458|    109.791|       0|     0|    00:00:25/00:00:25   
> > root at arago:~# 
> 
> Note that if the OMAPL138 is an armv4 or armv5, you may want to enable
> the FCSE in order to reduce context switch time (and latencies).
> 
> 

I enabled FCSE, and the max latency is more consistent (though the min
and average  latency has climbed).  How do the below figures look?


root at arago:~# xeno latency -T 25                                                
== Sampling period: 1000 us                                                     
== Test mode: periodic user-mode task                                           
== All results in microseconds                                                  
warming up...                                                                   
RTT|  00:00:01  (periodic user-mode task, 1000 us period, priority 99)          
RTH|----lat min|----lat avg|----lat max|-overrun|---msw|---lat best|--lat worst 
RTD|      8.499|     32.874|    105.791|       0|     0|      8.499|    105.791 
RTD|      8.041|     18.458|     80.416|       0|     0|      8.041|    105.791 
RTD|      8.416|     14.124|     62.374|       0|     0|      8.041|    105.791 
RTD|      8.791|     14.666|     66.541|       0|     0|      8.041|    105.791 
RTD|      8.249|     14.749|     69.916|       0|     0|      8.041|    105.791 
RTD|      8.749|     17.833|     87.208|       0|     0|      8.041|    105.791 
RTD|      8.499|     18.291|     77.583|       0|     0|      8.041|    105.791 
RTD|      8.291|     14.166|     65.541|       0|     0|      8.041|    105.791 
RTD|      8.458|     14.624|     64.874|       0|     0|      8.041|    105.791 
RTD|      8.249|     14.208|     66.624|       0|     0|      8.041|    105.791 
RTD|      8.708|     17.208|     86.041|       0|     0|      8.041|    105.791 
RTD|      8.708|     18.374|     76.291|       0|     0|      8.041|    105.791 
RTD|      8.499|     14.958|     71.458|       0|     0|      8.041|    105.791 
RTD|     16.041|     24.291|     85.541|       0|     0|      8.041|    105.791 
RTD|      8.083|     14.083|     64.749|       0|     0|      8.041|    105.791 
RTD|      8.833|     17.416|     87.666|       0|     0|      8.041|    105.791 
RTD|      8.749|     24.416|     81.208|       0|     0|      8.041|    105.791 
RTD|      8.458|     14.083|     67.374|       0|     0|      8.041|    105.791 
RTD|      8.041|     14.624|     64.958|       0|     0|      8.041|    105.791 
RTD|      8.666|     23.499|     84.333|       0|     0|      8.041|    105.791 
RTD|      7.749|     17.083|     80.249|       0|     0|      7.749|    105.791 
RTT|  00:00:22  (periodic user-mode task, 1000 us period, priority 99)          
RTH|----lat min|----lat avg|----lat max|-overrun|---msw|---lat best|--lat worst 
RTD|      7.916|     18.208|     81.541|       0|     0|      7.749|    105.791 
RTD|      8.541|     27.541|    102.958|       0|     0|      7.749|    105.791 
RTD|      8.249|     14.083|     64.416|       0|     0|      7.749|    105.791 
---|-----------|-----------|-----------|--------|------|------------------------
RTS|      7.749|     18.041|    105.791|       0|     0|    00:00:25/00:00:25   
root at arago:~# 



-- 
Peter Howard <pjh at northern-ridge.com.au>





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