A class of rate-based real-time scheduling algorithms

Abstract

This paper investigates a class of rate-based real-time scheduling algorithms based on the idea of general processor sharing (GPS). We extend the GPS framework of Parekh and Gallager (1993) for periodic and sporadic process scheduling and show the optimality of GPS-based scheduling. In particular, we propose the earliest-completion-time GPS (EGPS) scheduling algorithm to simulate the GPS algorithm with much lower run-time overheads. The schedulability of each process is enforced by a guaranteed CPU service rate, independent of the demands of other processes. We provide a theoretical foundation to assign proper CPU service rates to processes to satisfy their individual stringent response time requirements. We also propose a GPS-based scheduling mechanism for jitter control. Finally, the performance of the proposed algorithms is studied using a generic avionics platform example and simulation experiments on jitter control and mixed soft and hard real-time process scheduling.