An Improved Model for System-Level Energy Minimization on Real-Time Systems

Energy-efficient scheduling has become an essential branch in the evolution of real-time systems due to requirements for reliability and portability. Such scheduling algorithms exploit the varying voltage/frequency capability of a processor to reduce its energy consumption. However, most of these algorithms assume an inaccurate linear correlation between memory latency and core frequency. To make the matter worse, the inclusion of caches has tarnished the predictability of such systems while also increasing the total energy consumption. Therefore, improved system and task models are crucial for further progression in this domain. In this paper, we propose improvements to existing models in order to incorporate the above-mentioned complexities. We then propose techniques to minimize core-, cache-and system-level energy consumptions. Extensive simulations demonstrate the effectiveness of our approach and the impact each proposed technique has on total energy consumption of the processor.