A significant volume of research has concentrated on Operating-System directed Power Management (OSPM). The primary focus of previous research has been the development of OSPM policies. Under different conditions, one policy may outperform another and vice versa. In this paper, the authors explain how to select the best policies at run-time without user or administrator intervention. They present a hardware-neutral architecture portable across different platforms running Linux. Their experiments reveal that changing policies at run-time can adapt to workloads more quickly than using any of the policies individually.