Proactive Scenario Characteristic-Aware Online Power Management on Mobile Systems

Modern mobile systems are requested to execute diverse user scenarios. Depending on the types of user scenarios, mobile systems utilize hardware resources differently. Thus, power management policies of mobile systems must adapt to various user scenarios. In this paper, we propose a dynamic voltage/frequency scaling (DVFS) policy to increase the energy efficiency of multicore mobile systems by adapting to user scenarios. The proposed policy provides effective power management regardless of user scenarios by using operation characteristics that can represent the execution behavior of various user scenarios. Furthermore, the proposed policy is suitable for modern mobile systems in which online power management is essential, because it does not require preliminary knowledge of target scenarios. To balance the trade-off between energy consumption and quality-of-service (QoS), the proposed scenario-aware policy provides `just enough' processing speed to process the requested amount of work at the given parallelism level. To demonstrate the practicality of the proposed policy, we evaluated the effectiveness of the proposed scenario-aware policy for real-world user scenarios. Compared to the conventional DVFS policies, the proposed scenario-aware policy achieved a maximum of 25.5% energy saving on the mobile system that uses asymmetric multicore CPU, and a maximum of 30.7% energy saving on the mobile system that uses symmetric multicore CPU, without any QoS violation that degrades user experiences.