Reward-based voltage scheduling for dynamic-priority hard real-time systems

Reward-based scheduling has been investigated for flexible applications in which an approximate but timely result is acceptable. Meanwhile, significant research efforts have been made on voltage scheduling which exploits the tradeoff between the processor speed and the energy consumption. In this paper, we address the combined scheduling problem of maximizing the total reward of hard real-time systems with a given energy budget. We present an optimal off-line algorithm and an efficient on-line algorithm for jobs with their own release-times/deadlines under Earliest-Deadline-First (EDF) scheduling. Experimental results show that the solution computed by the on-line algorithm is no more than 14% worse than the theoretical optimal solution obtained by the optimal off-line algorithm.