[Xenomai] OMAP L138

Peter Howard pjh at northern-ridge.com.au
Wed Apr 9 06:27:38 CEST 2014


On Wed, 2014-04-09 at 10:34 +1000, Peter Howard wrote:
> On Wed, 2014-04-09 at 02:20 +0200, Gilles Chanteperdrix wrote:
> > On 04/09/2014 01:30 AM, Peter Howard wrote:
> > > 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?
> > 
> > Otherwise, it is hard to say whether there is an issue or not. It is not
> > uncommon for armv4 or armv5 to have high latencies like this.
> > On what core is this processor based, running at what frequency?
> > 
> > 
> It's an AMR926EJ-S r5.  Datasheet claims 375MHz, U-boot claims 300MHz.
> 
> Load test to follow.
> 

OK, this run was done with LTP running on the board (runltplite.sh),
with cpu utilization between 90% and 100%

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|     29.999|     45.083|     80.833|       0|     0|     29.999|     80.833
RTD|     35.416|     49.083|     94.666|       0|     0|     29.999|     94.666
RTD|     19.749|     45.374|     83.874|       0|     0|     19.749|     94.666
RTD|     28.291|     47.999|     96.458|       0|     0|     19.749|     96.458
RTD|     16.999|     54.458|    107.041|       0|     0|     16.999|    107.041
RTD|     15.458|     60.083|    100.374|       0|     0|     15.458|    107.041
RTD|     39.041|     74.333|     97.041|       0|     0|     15.458|    107.041
RTD|     39.416|     73.874|     97.624|       0|     0|     15.458|    107.041
RTD|     39.624|     74.249|    104.749|       0|     0|     15.458|    107.041
RTD|     39.666|     74.458|    103.333|       0|     0|     15.458|    107.041
RTD|     42.499|     74.583|    105.874|       0|     0|     15.458|    107.041
RTD|     38.333|     74.583|     96.416|       0|     0|     15.458|    107.041
RTD|     39.833|     74.083|     99.916|       0|     0|     15.458|    107.041
RTD|     37.749|     75.166|    105.708|       0|     0|     15.458|    107.041
RTD|     40.833|     74.749|     97.791|       0|     0|     15.458|    107.041
RTD|     34.833|     74.083|     98.624|       0|     0|     15.458|    107.041
RTD|     42.249|     74.249|     96.708|       0|     0|     15.458|    107.041
RTD|     41.916|     74.499|    103.208|       0|     0|     15.458|    107.041
RTD|     34.166|     74.374|    102.833|       0|     0|     15.458|    107.041
RTD|     44.583|     74.791|    101.291|       0|     0|     15.458|    107.041
RTD|     38.041|     74.458|    103.083|       0|     0|     15.458|    107.041
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|     43.249|     74.416|     97.124|       0|     0|     15.458|    107.041
RTD|     40.749|     74.166|    104.874|       0|     0|     15.458|    107.041
RTD|     40.791|     74.791|     97.833|       0|     0|     15.458|    107.041
---|-----------|-----------|-----------|--------|------|-------------------------
RTS|     15.458|     68.416|    107.041|       0|     0|    00:00:25/00:00:25
root at arago:~# 

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





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