Multicore processor power credit management in which multiple processing cores use shared memory to communicate individual energy consumption

Abstract

A microprocessor includes two or more processing cores each configured to compute a first value in response to detecting a power event. The first value represents an amount of energy the core consumed during a time interval leading up to the event. The length of the time interval is predetermined. Each core reads from the memory one or more second values that represent an amount of energy the other cores consume during approximately the time interval. The second values were previously computed and written to the memory by the other cores. Each core adjusts its operating frequency based on the first and second values. The predetermined frequency may be: a frequency at which all the cores can operate over the predetermined length of time without the microprocessor consuming more than the predetermined amount of energy, or alternatively the maximum frequency at which system software may request the cores to operate.