Chameleon

Abstract

In this paper, we present Chameleon---an application-level power management approach for reducing energy consumption in mobile processors. Our approach exports the entire responsibility of power management decisions to the application level. We propose an operating system interface that can be used by applications to achieve energy savings. We consider three classes of applications---soft real-time, interactive and batch---and design user-level power management strategies for representative applications such as a movie player, a word processor, a web browser, and a batch compiler. We also design a user level power manager based on GraceOS using Chameleon. We implement our approach in the Linux kernel running on a Sony Transmeta laptop. Our experiments show that, compared to the traditional system-wide CPU voltage scaling approaches, Chameleon can achieve up to 32-50% energy savings while delivering comparable or better performance to applications. Further, Chameleon imposes small overheads and is very effective at scheduling concurrent applications with diverse energy needs.