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 T₀ that need to be scheduled at time 0. We derive a property PT on T₀ such that if T₀ satisfies this property, any task set T_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_t, t>0