Dynamic counters and the efficient and effective online power management of embedded real-time systems

Energy consumption has become an important issue for modern embedded systems. This is because, one does not only like to deploy high-performance systems and provide guaranteed services, but also request system deployments to last as long as possible. With online dynamic power management (DPM), one adaptively changes the system´s power mode, i. e., schedules when to turn on and off on-the-fly, to achieve energy savings. This paper introduces dynamic counters and discusses their usage in the context of (online) DPM in a setting where systems have to fulfill hard real-time requirements. The proposed scheme enables one to conservatively bound the future workload and thereby to safely schedule on- and off-periods of devices. Simulation results indicate that the proposed technique is more efficient and more effective with respect to energy savings, compared to previous work.