Energy-Saving DVFS Scheduling of Multiple Periodic Real-Time Tasks on Multi-core Processors

This paper addresses an energy-saving scheduling scheme of periodic real-time tasks with the capability of dynamic voltage and frequency scaling, on the lightly loaded multi-core platform containing more processing cores than running tasks. First, it is shown that the problem of minimizing energy consumption of real-time tasks is NP-hard even on the lightly loaded multi-core platform. Next a heuristic scheduling scheme is proposed to find an energy-efficient schedule with a low time complexity while meeting the deadlines of real-time tasks. The scheme exploits overabundant cores to reduce energy consumption using parallel execution and turns off the power of unused or rarely used cores. Evaluation shows that the proposed scheme saves up to 64% energy consumption of the existing method executing each task on a separate core.