Hi,
 
>>> I notice you are using -rt kernel. Do you actually need realtime
>>> features?
>>
>> Yes, I actually need the realtime feature. I have one task which
>> needs to run periodically in realtime (triggered every 10ms by an
>> external IRQ).
>>
>
> Please don't forget to share your kernel config with us so that we can
> make sure your use case is covered subsystem-wise in CIP. From Siemens
> side, we still have room for improvements in this regard, even more on -rt.
 
Attached you can find my kernel config. 
 
>> Jun 1 09:11:46 sicam kernel: [46802.944299] [<c062f854>] (dump_stack) from [<c03a57ec>] (check_preemption_disabled+0x110/0x114)
>> Jun 1 09:11:46 sicam kernel: [46802.944316] [<c03a57ec>] (check_preemption_disabled) from [<c014163c>] (migrate_enable+0x40/0x488)
>> Jun 1 09:11:46 sicam kernel: [46802.944338] [<c014163c>] (migrate_enable) from [<c053ff0c>] (ip_finish_output2+0x21c/0x460)
>
> Migration should be on across migration-disabled sections, that's their
> whole purpose. But maybe the check that preemption needs to be off when
> using smp_processor_id needs relaxing to at least migration must be off.

Sorry, but I can not follow your words. What do you mean with 'needs relaxing to
at least migration must be off'?

Thanx,
Rainer