Distributed pinwheel scheduling with end-to-end timing constraints

Algorithms for allocating resources and scheduling tasks are important to the success of many real-time systems with end-to-end performance requirements. In this paper, an end-to-end scheduling model based on the pinwheel scheduling algorithms is presented for distributed real-time systems. We discuss how tasks on different nodes may be transformed to have harmonic periods. We also present algorithms to adjust the phases between schedules on neighboring nodes so that the overall end-to-end delay is reduced. Using the pinwheel approach, schedules on different nodes are closely synchronized and more static. However, for many real-time systems, this practical approach may provide a more predictable performance and a shorter end-to-end delay.