Resource reservation and power management in Android

Abstract: Saving battery time for mobile devices has been a goal for the industry for many years. With the advent of smartphones, reduction of energy consumption is even more important since they consume a lot more energy than the generation of mobile phones before them. Consumers are demanding longer battery life and greener electronics. One way to meet these demands is to reduce energy consumption. In order to make the mobile operating system utilize the Central Processing Unit (CPU) more efficiently, applications should have different reservations based on how much they need to use the CPU. A challenge the industry is facing is its lack of knowledge of the behavior of third party applications. Especially since they are an increasing portion of the applications run on smartphones. Without knowledge of how third party applications behave, it is hard to make good reservations for them. If there was a way to dynamically make reservations for the applications with adequate performance while they are running, the system could use this information to reduce battery consumption by e.g. clocking down the CPU when a high clock frequency is not needed. In this master thesis project, an open source resource manager called ACTORS Resource Manager (ACTORS RM) [5][6] for desktop Linux [57] is ported to the Android [37] operating system. The resource manager is also optimized for the applications being run there. A power management patch to the Linux kernel was also used to get greater control over the CPU's frequency changes.