[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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