Timing-Anomaly Free Dynamic Scheduling of Periodic DAG Tasks with Non-Preemptive Nodes

Abstract

Designing timing-anomaly free multiprocessor scheduling algorithms is a notoriously hard problem, especially for parallel tasks with non-preemptive execution regions. In this paper, we first propose a simple yet expressive model which abstracts a parallel task as a single computation unit, and then, present a sufficient condition for timing-anomaly free scheduling of such units. On top of this, we design an algorithm for scheduling a set of periodic parallel tasks, represented as DAG with non-preemptive subtasks, on multicore processors. The algorithm has several desirable properties, including timing-anomaly freedom, high resource utilization, and low memory requirement. Timing-anomaly freedom enables an exact schedulability test for the algorithm, which, as shown in our evaluations, provides a significantly high schedulability ratio compared to those state-of-the-art methods that suffer from timing anomalies.