Properties of hard real-time tasks for on-line scheduling on multiprocessors

We consider the properties of hard real-time tasks in the context of online scheduling on multiprocessors in an environment where the parameters concerning the set of all future tasks are not known a-priori. We consider a set of ready tasks T/sub 0/ that need to be scheduled at time 0. We derive a property PT on T/sub 0/ such that if T/sub 0/ satisfies this property, any task set T/sub t/, t>0, whose parameters are not known a-priori, can be scheduled successfully online. We also give an online scheduler called MLLA. Further, we show that if a task set does not satisfy the property PT, there exists no online scheduler which can schedule any future task set T/sub t/, t>0.