Slack Time Management for Imprecise Mixed-Criticality Systems With Reliability Constraints

A Mixed-Criticality System (MCS) integrates multiple applications with different criticality levels on the same hardware platform. For power and energy-constrained systems such as Unmanned Aerial Vehicles, it is important to minimize energy consumption of the computing system while meeting reliability constraints. In this paper, we first determine the number of tolerated faults according to the given reliability target. Second, we propose a schedulability test for MCS with semi-clairvoyance and checkpointing. Third, we propose the Energy-Aware Scheduling with Reliability Constraint (EASRC) scheduling algorithm for MCS with semi-clairvoyance and checkpointing. It consists of an offline phase and an online phase. In the offline phase, we determine the offline processor speed by reclaiming static slack time. In the online phase, we adjust the processor speed by reclaiming dynamic slack time to further save energy. Finally, we show the performance of our proposed algorithm through experimental evaluations. The results show that the proposed algorithm can save an average of 9.67% of energy consumption compared with existing methods.