HiCAP: Hierarchical FSM-based Dynamic Integrated CPU-GPU Frequency Capping Governor for Energy-Efficient Mobile Gaming

Abstract

Contemporary mobile platforms use software governors to achieve high performance with energy-efficiency for heterogeneous CPU-GPU based architectures that execute mobile games and other graphics-intensive applications. Mobile games typically exhibit inherent behavioral dynamism, which existing governor policies are unable to exploit effectively to manage CPU/GPU DVFS policies. To overcome this problem, we present HiCAP: a Hierarchical Finite State Machine (HFSM) based CPU-GPU governor that models the dynamic behavior of mobile gaming workloads, and applies a cooperative, dynamic CPU-GPU frequency-capping policy to yield energy efficiency adapting to the game's inherent dynamism. Our experiments on a large set of 37 mobile games exhibiting dynamic behavior show that our CAP dynamic governor policy achieved substantial energy efficiency gains of up to 18% improvement in energy-per-frame over existing governor policies, with minimal degradation in quality.