Re: [Xenomai-help] Oops during rt_event_wait(); formerly "How do I force..."

[Bob Feretich <bob.feretich@domain.hid>]

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  I changed the subject from "How do I force a core dump on a page fault 
event?", because the thread's topic has drifted.
Comments inline...
On 9/8/2010 12:55 AM, Gilles Chanteperdrix wrote:
> ...Snipped...
>> No. This problem started occurring when I integrated the whole system
>> together. I'm going to have to work on it a bit to reduce it to a
>> suitable code segment .
>> The Xenomai content of the loop is:
>> while (!end) {
>>       ...
>>       rc = rt_event_wait(&event1,..);
>>       ...
>>       rc = rt_event_clear(&event1,..);
>>       ...
>>       rc = rt_event_wait(&event2,..);
>>       ...
>>       rc = rt_event_clear(&event2,..);
>>       ...
>>       rc = rt_event_wait(&event3, TM_NONBLOC, ...);
>>       if (rc==0) end = 1;
>> }
> Is this is a loop using all the CPU (all the events with TM_NONBLOCK) ?
No, just the last wait has TM_NONBLOCK. CPU utilization for the task is 
about 2%.

I examined my use of the rt_event mechanism, trying to identify how my 
use might be unusual.

    * The above calls are in a rt-user-task and are bracketed with
      bind/unbind, outside the loop. The task starts in secondary mode,
      performs the loop in primary mode, then finishes in secondary mode.
    * rt_event_create and rt_event_delete occur in a rtdm driver init
      and exit routines.
    * However, rt_event_signal is invoked in interrupt handlers. I think
      that this may be unusual. Normally, interrupt handlers would use
      the rtdm_event mechanism.

Could rt_event_signal be sensitive to being invoked from the context of 
a real time interrupt?

Interrupt handler stack space is usually quite small. Does 
rt_event_signal make heavy use of the stack?

Regards,
Bob Feretich

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