Synchronization-Driven Dynamic Speed Scaling for MPSoCs

Equalizing the ratios between workloads and speeds of processing elements provides the optimal speed allocation. Based on that prin-ciple, this work describes a dynamic speed setting policy for multi-processor systems-on-chip (MPSoCs) that relies on the estimation of processor idle times specifically due to the synchronization work. The policy provides two advantages: first, it does not rely on any assumption about the communication pattern of the application ex-ecuted by the system. Second, it is purely architectural; it automat-ically detects changes in the system workload and sets processors speeds accordingly by means of a custom hardware block. Results on a parallel MPEG video decoding application show an EDP saving above 55%, averaged over several datasets, corre-sponding to an energy saving above 50%, and a corresponding penalty in performance below 8%