Power-aware operating systems for interactive systems

Many portable systems deploy operating systems (OS) to support versatile functionality and to manage resources, including power. This paper presents a new approach for using OS to reduce the power consumption of I/O devices in interactive systems. Low-power OS observes the relationship between hardware devices and processes. The OS kernel estimates the utilization of a device from each process. If a device is not used by any running process, the OS puts it into a low-power state. This paper also explains how scheduling can facilitate power management. When processes are properly scheduled, power reduction can be achieved without degrading performance. We implemented a prototype on Linux to control two devices; experimental results showed nearly 70% power saving on a network card and a hard disk drive.