[Xenomai-core] Re: soft lockup detected on AT91RM9200

[Steven Scholz <steven.scholz@domain.hid>]

Gilles,

>> When starting latency with 100µs period I get
>>
>> ~ # latency
>> == Sampling period: 100 us
>> == Test mode: periodic user-mode task
>> == All results in microseconds
>> warming up...
>> BUG: soft lockup detected on CPU#0!
>> ...
>>
>> Ideas? How can I help with debugging this?
> 
> 100us is too small, as I already told you here:
> 
> https://mail.gna.org/public/xenomai-core/2007-02/msg00019.html

No. That's probably a different thing. I am going to write a mail soon.

> The latency process spend 100% of its time handling the timer ticks, and
> the kernel detects a soft lockup.
> 
> The difference between I-pipe patch 1.6-01 and 1.6-02 is that the return
> from exception is correctly handled. Maybe it is what allows the kernel
> to print a clean message. Maybe it is because you now have enabled the
> soft lockup detector whereas you previously did not.
Ok. Maybe.

I don't care about missing deadlines. That's fine iff I overload the system.

But I still would have expected printout on the serial console. But ok,
maybe the print in latency is done in a non-realtime task. So fair enough.

Steven