Re: [Xenomai] Regarding Xenomai and RTNET

[Leopold Palomo-Avellaneda <leo@alaxarxa.net>]

El Divendres, 30 de setembre de 2016, a les 16:06:15, Philippe Gerum va 
escriure:
> On 09/30/2016 02:15 PM, Leopold Palomo-Avellaneda wrote:
> > Hi,
> > 
> > 
> > I'm fighting with some code to run with Xenomai 3. One of the projects is
> > soem [1].
> > 
> > The original library uses POSIX to open a raw socket to send Ethercat
> > messages. Our fork, uses rtnet and some Xenomai functionalities to
> > accomplish it. It has been working with 2.6.x without any problems.
> > 
> > OTOH, also we have done another fork fril  [2] that, using the POSIX
> > compatibility and rtnet use a rt_ethX device to communicate with a robot.
> > We have used it without any problem too with 2.6.x
> > 
> > Now, we try to migrate all of this code to Xenomai-3 but we are having
> > crashes all the time.
> > 
> > With fril, a pure POSIX code, using the compatibility mode, we have a
> > crash,> 
> > showing:
> >  BUG: unable to handle kernel paging request at 00007f47ea0ef878
> >  IP: [<ffffffffa0231580>] rt_udp_ioctl+0x50/0x74 [rtudp]
> >  PGD 458887067 PUD 4590a1067 PMD 45921f067 PTE 8000000438863867
> 
> [snip]
> 
> > If both the program crashes "unable to handle kernel paging request".
> 
> The compat mode is not related to this issue, it is merely a source code
> wrapping trick at user level, nothing more. If a driver breaks the
> kernel, then it's the driver's fault no matter what, regardless of the
> input data userland might have sent.

Ok.

> You should check the RTnet stack for this. Btw, assuming your 2.6 setup
> relies on the original out-of-tree RTnet, and that your 3.0
> configuration relies on the RTnet code integrated in the Xenomai tree,
> then you end up comparing two different RTnet implementations.

I'm investigating this issue. I have found an interesting detail. I'm using 
rt_igb module. The first time I upload the module, it's loaded (showed with 
lsmod) but no rtethX interface is found. So, if I rmmod it and I load it 
again, then the rtethX are found.

Any idea why this?

In any case, we are talking to debug rtnet modules. Right?


> > Also, I have found that using the --compat parameter in xeno-config, the
> > values obtained (--posix --compat --cflags) makes that the applications
> > doesn't> 
> > compile:
> >  
/home/leopold.palomo/fril/fril.git/src/FastResearchInterfaceLibrary/Console.cpp:50:
> > /usr/xenomai/include/trank/posix/pthread.h: In function ‘int
> > pthread_set_mode_np(int, int, int*)’:
> > /usr/xenomai/include/trank/posix/pthread.h:55:52: error:
> > ‘pthread_setmode_np’ was not declared in this scope
> > 
> >   return pthread_setmode_np(clrmask, setmask, mask_r);
> > 
> > I guess that there's a missing includes hidden here.
> 
> No, it's rather an issue in the include directory chain when --compat is
> enabled. Fixed in xeno-config, in the stable maintenance tree.
> 
> > So, any idea to find a solution?
> > Do you have some example that works with xenomai-3 and rtnet?
> 
> No, but I'm no RTnet expert.

Jan?

Leopold

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