Improving energy-efficient real-time scheduling by exploiting code instrumentation

Dynamic frequency and voltage scaling is a promising technique to save energy in real-time systems. In this work we present a novel light-weight energy-efficient EDF scheduler designed for processors with discrete frequencies with performs on-line intra- and inter-task frequency scaling at the same time. An intra-task scheduling scheme based on cycle counters of a processor allows the application of our approach to shared code of library functions and to task setups where only spare intra-task information is available. Our dasiaIntra-Task Characteristics Aware EDFpsila (ItcaEDF) scheduler which aims to run with a low frequency by eliminating idle time and inter- and intra-task slack times was evaluated in an compiler, WCET analysis, and simulation framework. Our experiments show that state-of-the-art clearly outperformed by our approach.