Optimal Multiprocessor Real-Time Scheduling Based on RUN for Practical Imprecise Computation with Harmonic Periodic Task Sets

Abstract

Optimal multiprocessor real-time scheduling can achieve full system utilization with implicit-deadline periodic task sets. However, worst case execution time (WCET) analysis is difficult on state-of-the-art hardware/software platforms because of the complex hierarchy of shared caches and multiprogramming. The actual case execution time (ACET) of each task is usually shorter than its WCET, and imprecise computation is one effective method to make better use of the remaining processor time. Unfortunately, there is no optimal multiprocessor real-time scheduling that supports imprecise computation. This paper proposes an algorithm that integrates the Reduction to Uniprocessor (RUN) algorithm as an optimal multiprocessor realtime scheduling and the Rate Monotonic with Wind-up Part (RMWP) algorithm as an imprecise-based real-time scheduling. This RUN-RMWP algorithm dominates the Partitioned RMWP algorithm. Simulation studies show that RUN-RMWP has a comparable number of preemptions/migrations to RUN and outperforms other imprecise-based non-optimal multiprocessor real-time scheduling algorithms.