Re: [Xenomai] Packaging Xenomai-3

[Philippe Gerum <rpm@xenomai.org>]

On 01/24/2015 06:56 PM, Leopold Palomo-Avellaneda wrote:
> A Divendres, 23 de gener de 2015, Gilles Chanteperdrix va escriure:
>> On Fri, Jan 23, 2015 at 05:50:07PM +0100, Leopold Palomo-Avellaneda wrote:
>>> El Divendres, 23 de gener de 2015, a les 16:52:31, Gilles Chanteperdrix
>>> va
>>>
>>> escriure:
>>>> On Fri, Jan 23, 2015 at 01:09:41PM +0100, Leopold Palomo-Avellaneda 
> wrote:
>>>>> Hi,
>>>>>
>>>>> now that I have some kernel to boot, I would like to ask some aspects
>>>>> of Xenomai-3 in order to package it.
>>>>>
>>>>> Reading the documentation, now the new libxenomai could use two kind
>>>>> of kernels: the patched one (Cobalt) or the preempt_rt (Mercury).
>>>>
>>>> a preempt_rt kernel is a patched kernel too.
>>>
>>> Writing the email I thought, both are patches, but I thought preempt_rt
>>> was integrated in mainline.
>>
>> No it is not.
>>
>>>>> 1) Is it possible to have _only_ one library (binary) that uses one
>>>>> or another kernel in function which is running?
>>>>
>>>> No, you could want to run a kernel with both patches. So basing the
>>>> decision on which patch you are running does not make sense.
>>>
>>> I don't want to run a kernel with both patches. It has no sense. But I
>>> could have binary packages that could work with both kernels. That was
>>> my idea.
>>
>> To the contrary, it has a lot of sense. You get one grade of
>> real-time for cobalt task, and another grade of real-time for tasks
>> scheduled by Linux.
> 
> Maybe ... it could be interesting as an experiment.

No, it's not just an experiment. I'm aware of production setups which
have been running this configuration since 2009. I did the mixed
ipipe+prempt-rt port for them.

> 
> Just for curiosity, have you had the test comparing in mercury and cobalt in 
> the same harware with the same problem?
> 

Yes, without any issue. Just use two different install roots, one for
cobalt, the other for mercury.

-- 
Philippe.