[Xenomai] patch the kernel?

[Xenomai] patch the kernel?

[Grant]

Is patching the kernel necessary in order to use xenomai?

- Grant

Re: [Xenomai] patch the kernel?

[Gilles Chanteperdrix]

On 11/13/2013 02:36 PM, Grant wrote:
> Is patching the kernel necessary in order to use xenomai?

It depends on which version of Xenomai you are talking about. If you are 
talking about Xenomai stable version, then yes, you have to follow the 
installation instructions here:
http://www.xenomai.org/documentation/xenomai-2.6/html/README.INSTALL/

Which include running the "prepare-kernel.sh" patch, which modifies the 
kernel.

If you are talking about Xenomai current development version, a.k.a. 
Xenomai forge, then it gives you the choice of running:
- on an unmodified kernel  (but you will not have real-time guarantees);
- a kernel patched with the PREEMPT_RT patch;
- a kernel modified as with the stable version.

The current state of Xenomai forge is that it is stable enough on the 
x86 and ARM architectures to run a latency test under load.

-- 
					    Gilles.

Re: [Xenomai] patch the kernel?

[Philippe Gerum]

On 11/13/2013 04:02 PM, Gilles Chanteperdrix wrote:
> On 11/13/2013 02:36 PM, Grant wrote:
>> Is patching the kernel necessary in order to use xenomai?
>
> It depends on which version of Xenomai you are talking about. If you are
> talking about Xenomai stable version, then yes, you have to follow the
> installation instructions here:
> http://www.xenomai.org/documentation/xenomai-2.6/html/README.INSTALL/
>
> Which include running the "prepare-kernel.sh" patch, which modifies the
> kernel.
>
> If you are talking about Xenomai current development version, a.k.a.
> Xenomai forge, then it gives you the choice of running:
> - on an unmodified kernel  (but you will not have real-time guarantees);
> - a kernel patched with the PREEMPT_RT patch;
> - a kernel modified as with the stable version.
>
> The current state of Xenomai forge is that it is stable enough on the
> x86 and ARM architectures to run a latency test under load.
>

blackfin and powerpc32 are ok too.
powerpc64 untested yet.

-- 
Philippe.

Re: [Xenomai] patch the kernel?

[Grant]

>> Is patching the kernel necessary in order to use xenomai?
>
> It depends on which version of Xenomai you are talking about. If you are
> talking about Xenomai stable version, then yes, you have to follow the
> installation instructions here:
> http://www.xenomai.org/documentation/xenomai-2.6/html/README.INSTALL/
>
> Which include running the "prepare-kernel.sh" patch, which modifies the
> kernel.
>
> If you are talking about Xenomai current development version, a.k.a. Xenomai
> forge, then it gives you the choice of running:
> - on an unmodified kernel  (but you will not have real-time guarantees);
> - a kernel patched with the PREEMPT_RT patch;
> - a kernel modified as with the stable version.
>
> The current state of Xenomai forge is that it is stable enough on the x86
> and ARM architectures to run a latency test under load.

Thanks I really need to try Xenomai forge.  I wish Gentoo had an
ebuild but there is a bug for it:

https://bugs.gentoo.org/show_bug.cgi?id=438236

- Grant

Re: [Xenomai] patch the kernel?

[Gilles Chanteperdrix]

On 11/14/2013 01:31 PM, Grant wrote:
>>> Is patching the kernel necessary in order to use xenomai?
>>
>> It depends on which version of Xenomai you are talking about. If you are
>> talking about Xenomai stable version, then yes, you have to follow the
>> installation instructions here:
>> http://www.xenomai.org/documentation/xenomai-2.6/html/README.INSTALL/
>>
>> Which include running the "prepare-kernel.sh" patch, which modifies the
>> kernel.
>>
>> If you are talking about Xenomai current development version, a.k.a. Xenomai
>> forge, then it gives you the choice of running:
>> - on an unmodified kernel  (but you will not have real-time guarantees);
>> - a kernel patched with the PREEMPT_RT patch;
>> - a kernel modified as with the stable version.
>>
>> The current state of Xenomai forge is that it is stable enough on the x86
>> and ARM architectures to run a latency test under load.
> 
> Thanks I really need to try Xenomai forge.  I wish Gentoo had an
> ebuild but there is a bug for it:
> 
> https://bugs.gentoo.org/show_bug.cgi?id=438236

Well, building xenomai user-space support is easy enough to compile
without a packaging system. It is just a matter of untarring the sources
and running

./configure
make
sudo make install

The documentation gives details about the available options, but the
defaults should be just fine.

-- 
                                                                Gilles.