An event-driven power management scheme for mobile consumer electronics

Dynamic processor power management based on periodic monitoring of processor load is being widely used to enhance battery life of mobile consumer electronics. The existing power management schemes, however, often lead to poor user-perceived responsiveness, which is a crucial factor for the quality of user experiences, by making inadequate or delayed decisions on the processor performance level. This paper presents a novel event-driven scheme of the processor power management to guarantee high responsiveness while minimizing ineffective energy consumption. The proposed scheme exploits the characteristic of an interactive event, which is triggered by a user input instead of a periodic timer interrupt. The prototype of the proposed event-driven scheme is implemented for an application launch event as an example. In order to quantify user-perceived responsiveness and energy consumption simultaneously, this paper introduces a latency measurement benchmark program. In the evaluation with the benchmark, the proposed power management scheme showed comparable responsiveness with higher energy savings up to 20 % than the existing dynamic schemes when the interactive workload is mixed with a CPU-intensive background task.