A Survey on Recent OS-Level Energy Management Techniques for Mobile Processing Units

To improve mobile experience of users, recent mobile devices have adopted powerful processing units (CPUs and GPUs). Unfortunately, the processing units often consume a considerable amount of energy, which in turn shortens battery life of mobile devices. For energy reduction of the processing units, mobile devices adopt energy management techniques based on software, especially OS (Operating Systems), as well as hardware. In this survey paper, we summarize recent OS-level energy management techniques for mobile processing units. We categorize the energy management techniques into three parts, according to main operations of the summarized techniques: 1) techniques adjusting power states of processing units, 2) techniques exploiting other computing resources, and 3) techniques considering interactions between displays and processing units. We believe this comprehensive survey paper will be a useful guideline for understanding recent OS-level energy management techniques and developing more advanced OS-level techniques for energy-efficient mobile processing units.