A METHOD, APPARATUS, AND SYSTEM FOR ENERGY EFFICIENCY AND ENERGY CONSERVATION INCLUDING DETERMINING AN OPTIMAL POWER STATE OF THE APPARATUS BASED ON RESIDENCY TIME OF NON-CORE DOMAINS IN A POWER SAVING STATE

摘要

A processor may determine the actual residency time of a non-core domain residing in a power saving state and based on the actual residency time the processor may determine an optimal power saving state (P-state) for the processor. In response to the non-core domain entering a power saving state, an interrupt generator (IG) may generate a first interrupt and the device drivers or an operating system may use the first interrupt to start a timer (first value). In response to the non-core domain exiting the power saving state, the IG may generate a second interrupt and the device drivers or an operating system may use the second interrupt to stop the timer (final value). The power management unit may use the final and the first value to determine the actual residency time.