Energy management for real-time embedded systems with reliability requirements

With the continued scaling of CMOS technologies and reduced design margins, the reliability concerns induced by transient faults have become prominent. Moreover, the popular energy management technique dynamic voltage and frequency scaling (DVFS) has been shown to have direct and negative effects on reliability. In this work, for a set of real-time tasks, we focus on the slack allocation problem to minimize their energy consumption while preserving the overall system reliability. Building on our previous findings for a single real-time application where a recovery task was used to preserve reliability, we identify the problem of reliability-aware energy management for multiple tasks as NP-hard and propose two polynomial-time heuristic schemes. We also investigate the effects of on-chip/off-chip workload decomposition on energy management, by considering a generalized power model. Simulation results show that ordinary energy management schemes could lead to drastically decreased system reliability, while the proposed reliability-aware heuristic schemes are able to preserve the system reliability and obtain significant energy savings at the same time.