CPU Clock Rate Control based on ART Application Behavior Monitoring without JIT

One of the most important issues in smartphones is power consumption. The CPU is one of the most power-consuming devices, and controlling the CPU clock rate affects the device's power consumption and performance. However, there is a trade-off between improving device performance and reducing power consumption. Increasing the CPU clock rate improves performance but increases power consumption. Conversely, decreasing the CPU clock rate reduces performance but helps reduce power consumption. Therefore, it is ideal to decrease the CPU clock rate when and only when its usage is low. However, the Linux kernel installed on Android smartphones controls the CPU clock rate by tracking past CPU usage. Therefore, when the CPU usage changes rapidly, there is a time lag between the CPU usage and the CPU clock rate. To address this issue, in our previous work, we proposed a CPU clock rate control concept based on observation of the behavior of the foreground application. In this paper, we demonstrate the effectiveness of the previously proposed method by implementing a simple CPU clock rate control system and comparing it with the existing scaling controller.