Preemptive Uniprocessor Scheduling of Non-cyclic GMF Task Systems

Formal models used for representing recurrent real-time processes are typically characterized by a period parameter, representing the minimum amount of time that may elapse between successive invocations of the process. However a recently proposed model called the non-cyclic GMF model deviates from this trend: there is no single period parameter characterizing the recurrent behavior of the task. In this paper we consider schedulability analysis of real-time systems comprised of collections of such tasks, that are to be scheduled using earliest-deadline first (EDF) scheduling on a single preemptive processor. We provide evidence that indicates that schedulability analysis for such systems is more difficult than for systems in which each recurrent task is characterized by a single period parameter, and derive a pseudo-polynomial time schedulability analysis algorithm for bounded-utilization systems of such tasks.