[Xenomai-help] Re: Re: A fairly small rtnet/Xenomai application that freezes the

["M. Koehrer" <mathias_koehrer@domain.hid>]

Hi Jan,

meanwhile I have done a couple of additional tests.
With one of the PCs I have, I have disabled the Memory Cache to slow it down.
The effect was the very same. 
I have reproduced the behaviour on another PC (also P4, but different mainboard).
The system freezes as well.
And finally, I have found out that printing out a line with printf() directly after the system() call provides
a workaround.Then the system is stable.

I have replaced the system() call where I called rtroute with a simple call to "ls -l" (i.e system("ls -l") ).
Then the system freezes as well.
It looks to me as if a system() call out of the realtime task is not properly handled.
An printf() after the system() call seems to move the system back on track...

Hope that helps a little bit to identify the issue...

Regards

Mathias 

> Hi Jan,
> 
> enclosed is the ethereal dump file.
> Unfortunately I do not have a slow machine... (We try to get the fastest
> machines running...).
> 
> Thanks for checking the application.
> 
> Mathias
> > > after a long debug-reboot-try-again-session I was able to reduce the
> > problem I had
> > > to a very short application that leads to a complete system freeze on a
> > 2.6.19.1 kernel.
> > > As with my PC I am not able to run the NMI stuff within Xenomai, I
> forward
> > the application to you
> > > and the list. Perhaps somebody can try out the enclosed application
> with
> > the latest Xenomai version
> > > on 2.6.19.1.
> > 
> > Thanks for the test case, I will give this a try ASAP.
> > 
> > > Please adjust the IP settings in the C file and in the xenorun script
> to
> > your setup.
> > > It is sufficient to send out UDP frames, if the remote device does not
> > answer this does not hurt.
> > > However the remote device should listen on a specified port to avoid
> ICMP
> > complains about
> > > no-opened UDP ports...
> > > Using Ethereal I monitored the traffic.
> > > Here is the summary of it:
> > > ARP request/response (from the xenorun script)
> > > ARP request/response (from the applicaion)
> > > UDP message to port 18765 (no answer)
> > > 2 seconds later: UDP message to port 18765 (no answer)
> > > 2+5=7 seconds later: ARP request/response (from the application)
> > > 2 seconds later: UDP message to port 18765
> > > Here the system freezes. I do not see the message "Step A".
> > 
> > Could you set me the Ethereal dump for reference? Just in case the test
> > does not kick immediately for me and I need to check the event flow.
> > 
> > > 
> > > One important piece is the system() call out of the realtime
> application
> > to do a rtroute.
> > > When I remove this call, there is no error...
> > > 
> > > 
> > > I am using Xenomai SVN #1969 and the included 2.6.19.1 patch. Pentium 4
> > UP.
> > 
> > Do you have a different (slower) execution platform at hand to check if
> > the CPU speed as influence on the lock-up? I hope it is not the case -
> > makes tracking easier. But it wouldn't be the first time.
> > 
> > > 
> > > Any feedback on this is highly welcome!
> > > 
> > 
> > You will get it.
> > 
> > Thanks again,
> > Jan
> > 
> > 
> 
> -- 
> Mathias Koehrer
> mathias_koehrer@domain.hid
> 


-- 
Mathias Koehrer
mathias_koehrer@domain.hid


Viel oder wenig? Schnell oder langsam? Unbegrenzt surfen + telefonieren
ohne Zeit- und Volumenbegrenzung? DAS TOP ANGEBOT JETZT bei Arcor: günstig
und schnell mit DSL - das All-Inclusive-Paket für clevere Doppel-Sparer,
nur  44,85 €  inkl. DSL- und ISDN-Grundgebühr!
http://www.arcor.de/rd/emf-dsl-2