Operating system power minimization through run-time processor resource adaptation

The increasingly constrained power budget of today's microprocessor has resulted in a situation where power savings of all components in a system have to be taken into consideration. The Operating System (OS), which manages both software and hardware resources, dissipates a significant portion of power in the execution of many modern applications. This paper profiles run-time OS power/performance characteristics and advocates a routine based OS-aware microprocessor resource adaptation mechanism to save run-time OS power. This approach permits precise hardware reconfigurations for the OS with low overhead and allows fine-grained performance/power tuning at the microarchitectural level. Simulation results show that compared to existing sampling-based adaptation schemes, this novel methodology yields a more attractive power and performance trade-off on OS execution. To our knowledge, this work is the first to address the power saving issue of the OS itself, an increasingly important area that has been largely overlooked in previous studies.