DORA: Optimizing Smartphone Energy Efficiency and Web Browser Performance under Interference

This paper proposes DORA - a dynamic frequency controller that maximizes the energy efficiency of smartphones subject to user satisfaction demands in the presence of memory interference stemmed from background processes and coscheduled applications. The proposed algorithm predicts the optimal energy-efficient frequency setting at runtime using staticallytrained performance, dynamic power, and leakage power models. The parameters of the models represent web page characteristics and dynamically varying architecture and system conditions. The algorithm is designed, implemented and extensively evaluated on a Google Nexus 5 smartphone using a variety of mobile web browsing workloads. The results show high prediction accuracies for the performance and power models of 97.5% and 96%, respectively. Overall, DORA improves the smartphone's energy efficiency by an average of 16% compared to the default Android frequency governor, interactive, while maintaining the desired levels of user satisfaction (web page load time).