Apple Inc.
Processor unit efficiency control

Abstract:

Embodiments provide for a computer implemented method comprising sampling one or more power and performance metrics of a processor; determining an energy cost per instruction based on the one or more power and performance metrics; determining an efficiency metric based on the energy cost per instruction; computing an efficiency control error based on a difference between a current efficiency metric and a target efficiency metric; setting an efficiency control effort based on the efficiency control error; determining a performance control effort, the performance control effort determined by a performance controller for the processor; and adjusting the performance control effort based on the efficiency control effort, wherein adjusting the performance control effort reduces power consumption of the processor.