Re: [Xenomai] Q on scheduling - rt_task_wait_period vs rtdm_wait_event

[Philippe Gerum <rpm@xenomai.org>]

On 06/07/2015 02:39 PM, Michael Haberler wrote:
> so far  we had multiple periodic RT threads of different priority, so a
> lower-priority thread would not preempt a higher-priority one
> 
> we are switching the scheduling of a low-priority thread from periodic to
> event-based - instead of rt_task_wait_period(), this task will now wait in
> an RTDM driver ioctl in rtdm_event_wait()
> 
> I assume the following to be true:
> 
> even if the rtdm_even_wait() terminates while a higher priority thread is
> running, the lower priority thread will not be scheduled until all
> higher-priority threads have entered rt_task_wait_period().
> 
> correct?
> 

Yes, assuming SCHED_FIFO for all of these threads. There is no reason
for implicitly changing the priority of a sleeper as a result of waking
it up from a blocking service.

-- 
Philippe.