2. Assuming a thread is waiting on a notification object for an irq to arrive, and another thread is running at the same priority when the irq arrives, the thread waiting on the notification object will not be woken until the currently running thread has exhausted it's timeslice.

And note that this is exactly how it *should* work: You’ve got the processor until the end of your time slice, *unless* preempted by a higher-prio thread.

Gernot