Energy-efficient scheduling fixed-priority tasks with preemption thresholds on variable voltage processors

Slowdown factors determine the extent of slowdown a computing system can experience based on functional and performance requirements. Dynamic Voltage Scaling (DVS), which adjusts the clock speed and supply voltage dynamically, is an effective technique in reducing the energy consumption of embedded real-time systems. We address the problem of computing static and dynamic slowdown factors in the FPPT algorithm. In this paper, Sufficient constraints have been identified for the feasibility of the task set using slowdown factors. We formulate this problem of computing the static slowdown factors for tasks as an nonlinear optimization problem to minimize the total energy consumption of the system. Our simulation experiments show on an average 17%similar to 53% energy gains over FPPT scheduling policy.