Dynamic Repartitioning of Real-Time Schedule on a Multicore Processor for Energy Efficiency

Abstract

Multicore processors promise higher throughput at lower power consumption than single core processors. Thus in the near future they will be widely used in hard real-time systems as the performance requirements are increasing. Though DVS may reduce power consumption for hard real time applications on single core processors, it introduces a new implication for multicore systems since all the cores in a chip should run at the same performance. Blind adoption of existing DVS algorithms may result in waste of energy since a core which requires low performance should run at the same high frequency with other cores. Based on the existing partitioning algorithms for the multiprocessor hard real-time scheduling, this article presents dynamic task repartitioning algorithm that balances task loads among cores to avoid the phenomena dynamically during execution. Simulation results show that in general cases our scheme makes additional energy saving more than 10% than that without our scheme even when the schedules are generated by WFD partitioning algorithm which is known as the best energy efficient partitioning algorithm.

This research was supported by the MIC(Ministry of Information and Communication), Korea, under the ITRC(Inofrmation Technology Research Center) support program supervised by the IITA(Institute of Information Technology Assessment) (IITA-2005-C1090-0502-0031).