Scheduling to Consolidate Idle Periods for Energy-Efficiency in Multicore Systems.

Abstract

PAL, POULOMI. Scheduling to Consolidate Idle Periods for Energy Efficiency in Multicore Systems. (Under the direction of Dr. Gregory T. Byrd.)

Power-efficiency and energy savings are the major drivers in the CPU design space. Design at all levels needs to be energy-aware in order to be considered seriously. With the emergence of mobile devices as a large market, energy efficiency has become of prime importance, as the emphasis now lies on making the battery last longer. Most modern cellphones are required to do much more than making and receiving calls. With 4G approaching quickly, the cellphone is required to be almost as good as any general purpose computer with respect to application complexities. This gives rise to the need for adaptive systems that can handle applications with high performance, and conserve energy as well. The research presented here provides a scheduling scheme which aims to consolidate CPU idle times, and to introduce some amount of inertia and determinism in the system, so as to provide the opportunity to switch CPUs into low-power modes for conservation of energy. The baseline used here is the Linux kernel-2.6.28, which implements distributed control for load balancing for different CPUs. Changes are made to this kernel, and CPU activity is used as the metric for comparison. It is found that the CPUs that are numbered higher get much longer idle periods, which can be used for switching to energy-efficiency mode, while still maintaining comparable performance.