[Xenomai-help] UDP-receive-task stalls

[Xenomai-help] UDP-receive-task stalls

[roderik.wildenburg]

We face the problem that a Xenomai task which receives UDP-packets
(secondary mode recvfrom()) on a high frequency ( every 50ms approx.
1200 Byte) stalls sporadically (few times a day). In this case the
ROOT-task permanently shows the priority of the stalled task, the
receive queue of the stalled task fills up (netstat -u) , the task never
comes to live again . Attaching gdb or strace to this task stalls these
tools also. Other tasks and Linux run as expected even other UDP-receive
tasks!
Any idea what can cause this problem or how we can debug the stalled
task? (I think we had a similar problem with select() I presented in
this list).
We use:
- Linux 2.4.25 PPC 
- Xenomai 2.4.9

Any help appreciated!
Roderik

--------------------------------------------------------
manroland AG
Vorsitzender des Aufsichtsrates: Hanno C. Fiedler
Vorstand: Gerd Finkbeiner (Vorsitzender), Dr. Ingo Koch, Dr. Markus Rall, Paul Steidle   
Sitz der Gesellschaft: Offenbach am Main, Registergericht: Amtsgericht Offenbach HRB-Nr. 42592
USt-Ident-Nr. DE 250200933

Re: [Xenomai-help] UDP-receive-task stalls

[Jan Kiszka]

On 2011-05-31 10:34, roderik.wildenburg@domain.hid wrote:
> We face the problem that a Xenomai task which receives UDP-packets
> (secondary mode recvfrom()) on a high frequency ( every 50ms approx.
> 1200 Byte) stalls sporadically (few times a day). In this case the
> ROOT-task permanently shows the priority of the stalled task, the
> receive queue of the stalled task fills up (netstat -u) , the task never
> comes to live again . Attaching gdb or strace to this task stalls these
> tools also. Other tasks and Linux run as expected even other UDP-receive
> tasks!
> Any idea what can cause this problem or how we can debug the stalled
> task? (I think we had a similar problem with select() I presented in
> this list).
> We use:
> - Linux 2.4.25 PPC 
> - Xenomai 2.4.9

Do you depend on CONFIG_XENO_OPT_PRIOCPL? If not, switch it off, it may
be involved here.

Jan

-- 
Siemens AG, Corporate Technology, CT T DE IT 1
Corporate Competence Center Embedded Linux

[Xenomai-help] Solved: UDP-receive-task stalls

[roderik.wildenburg]

Turned out that it was a simple segmentation fault, but SIGSEGV was captured by a vendor library so we didn´t realize it.
Sorry for blaming  Xenomai!
Roderik


> -----Ursprüngliche Nachricht-----
> Von: Jan Kiszka [mailto:jan.kiszka@domain.hid]
> Gesendet: Dienstag, 31. Mai 2011 11:00
> An: Wildenburg, Roderik RAEK1 MRA
> Cc: xenomai@xenomai.org
> Betreff: Re: UDP-receive-task stalls
> 
> On 2011-05-31 10:34, roderik.wildenburg@domain.hid wrote:
> > We face the problem that a Xenomai task which receives UDP-packets
> > (secondary mode recvfrom()) on a high frequency ( every 50ms approx.
> > 1200 Byte) stalls sporadically (few times a day). In this case the
> > ROOT-task permanently shows the priority of the stalled task, the
> > receive queue of the stalled task fills up (netstat -u) , the task never
> > comes to live again . Attaching gdb or strace to this task stalls these
> > tools also. Other tasks and Linux run as expected even other UDP-receive
> > tasks!
> > Any idea what can cause this problem or how we can debug the stalled
> > task? (I think we had a similar problem with select() I presented in
> > this list).
> > We use:
> > - Linux 2.4.25 PPC
> > - Xenomai 2.4.9
> 
> Do you depend on CONFIG_XENO_OPT_PRIOCPL? If not, switch it off, it may
> be involved here.
> 
> Jan
> 
> --
> Siemens AG, Corporate Technology, CT T DE IT 1
> Corporate Competence Center Embedded Linux

--------------------------------------------------------
manroland AG
Vorsitzender des Aufsichtsrates: Hanno C. Fiedler
Vorstand: Gerd Finkbeiner (Vorsitzender), Dr. Ingo Koch, Dr. Markus Rall, Paul Steidle   
Sitz der Gesellschaft: Offenbach am Main, Registergericht: Amtsgericht Offenbach HRB-Nr. 42592
USt-Ident-Nr. DE 250200933