Re: [Xenomai-core] arm ixp: more trouble with recent xenomai

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

Richard Cochran wrote:
> On Sat, Apr 09, 2011 at 09:50:16PM +0200, Gilles Chanteperdrix wrote:
>>> Just to have an idea where the issue come from, could you try reverting
>>> all the changes which were made on the tsc and timer? i.e. revert to the
>>> original ipipe_mach_get_tsc and ipipe_mach_set_dec?
>>>
>> The exact commit to revert is this one:
>> http://git.xenomai.org/?p=ipipe-gch.git;a=commitdiff;h=cbd591ed5797f105ff45e04cca3bc939388624ea;hp=a2761e92ecd573bc3a3b068d4ebb7cc06313213c
> 
> Okay, with cbd591ed57 reverted, it works fine even without IPIPE_DEBUG.
> 
> The performance is still about 20 usec worse than xenomai 2.4 with ipipe 2.6.30.
> 
>   |------------+------+---------+-------+---------+---------+---------+----------|
>   | Kernel     |      | Xeno    | IPIPE |         |         |         |          |
>   | Vers       | FCSE | Vers    | DEBUG | lat min | lat avg | lat max | duration |
>   |------------+------+---------+-------+---------+---------+---------+----------|
>   | v30        | yes  | v2.4.10 | no    |   8.430 |  17.310 |  63.510 | 00:02:35 |
>   | v31        | yes  | v2.5.6  | no    |   7.215 |  34.020 |  85.350 | 00:02:58 |
>   | v33        | yes  | v2.5.6  | yes   |  17.250 |  55.815 | 127.516 | 00:02:00 |
>   | v35        | yes  | v2.5.6  | yes   |   7.140 |  34.200 |  84.180 | 00:02:17 |
>   | v35-revert | yes  | v2.5.6  | no    |   7.350 |  29.430 |  85.185 | 00:05:50 |
>   | v35        | no   | v2.5.6  | no    |   6.960 | 109.500 | 214.156 | 00:09:41 |
>   |------------+------+---------+-------+---------+---------+---------+----------|
> 
> I will try xenomai 2.5 with ipipe 2.6.35 next...

Ok, please try Xenomai 2.5.6 with I-pipe for 2.6.30, in order to know if
the difference comes from the I-pipe of from Xenomai. You can also play
with the various I-pipe versions, going back in the releases.

Note that with FCSEv4, you probably want "preemptible cache flushes"
with FCSE guaranteed. And of course, please do not enable FCSE_DEBUG for
performances testing.

You can also try and enable the I-pipe tracer. But I am not sure it
works on all versions.

-- 
                                                                Gilles.