Event-driven processor power management

Abstract

Energy-efficient computing as a research area has been receiving increasing attention in recent years due to rising energy costs and environmental awareness. In this paper, we present an approach to increasing the energy efficiency of modern multi-core computers, which is suitable for scenarios with varying load characteristics often found in private and small office/home office (SOHO) machines. The approach is based on a closer integration of the operating system scheduler and frequency governor, while shifting the mode of operation from time-driven to event-driven. We discuss theoretical as well as practical considerations, and describe experiments for both desktop and server systems. Based on a fully functional implementation within the Linux kernel, it is shown that our approach is feasible and allows for power savings of up to 10% while delivering a performance comparable to disabled power management and being more energy-efficient than the traditional time-driven variant.