SELECTABLE AND HIERARCHICAL POWER MANAGEMENT

Described are systems and methods for power management. A processing system includes one or more cores and a connected power management unit (PMU). The PMU is selected from one of: a first level PMU which can power scale a; a second level PMU which can independently control power from a shared cluster power supply to each core of two or more cores in a cluster; a third level PMU where each core includes a power monitor which can track power performance metrics of an associated core; and a fourth level PMU when a complex includes multiple clusters and each cluster includes a set of the one or more cores, the fourth level PMU including a complex PMU and a cluster PMU for each of the multiple clusters, the complex PMU and cluster PMUs provide two-tier power management. Higher level PMUs include power management functionality of lower level PMUs.