Process Oriented Power Management

Though modern operating systems are capable of controlling power consumption using the DVFS (dynamic voltage and frequency scaling) mechanism, power consumption is controlled for some duration according to the runtime statistics. Thus, some interactive processes suffer in response time when the system is slowed. This paper proposes the process-oriented power management mechanism (POPM), that controls the operating speed of each process separately, instead of some interval. When a process context switch occurs, POPM determines the most appropriate speed for the next process, and changes CPU frequency to the corresponding value. In order to determine the speed of each process, POPM analyzes the runtime information of each process: e.g., I/O or CPU usage. We develop a prototype of POPM on the Linux Kernel 2.6, and evaluate it on a Laptop PC. Our experimental results show that POPM reduces power consumption of the system without reminding users that the system is slowed down.