Discrete feedback-based dynamic voltage scaling for safety critical real-time systems

Recently, the tradeoff between low energy consumption and high fault-tolerance has attracteda lot of attention as a key issue in the design of real-time systems. dynamic voltage scaling (dvs) iscommonly employed as one of the most effective low energy techniques for real-time systems. it has beenobserved that the use of feedback-based methods can improve the effectiveness of dvs-enabled systems.in this paper, we have investigated reducing the energy consumption of fault-tolerant hard real-timesystems using the feedback control theory. our proposed method makes the system capable of selectingthe proper frequency and voltage settings in order to reduce the energy consumption, while guaranteeinghard real-time requirements in the presence of unpredictable workload fluctuations and faults. in theproposed method, the available slack-time is exploited by a feedback-based dvs at runtime to reducethe energy consumption. furthermore, some slack-time is reserved for re-execution in case of faults. thesimulation results show that compared with the traditional dvs method, our proposed method not onlyprovides up to 59% energy saving, but also satisfies hard real-time constraints. our proposed method isalso effective in harnessing the static energy. the transition overheads are also taken into account in oursimulation experiments.