Prediction-guided performance-energy trade-off for interactive applications

Many modern mobile and desktop applications involve real-time interactions with users. For these interactive applications, tasks must complete in a reasonable amount of time in order to provide a responsive user experience. Conversely, completing a task faster than the limits of human perception does not improve the user experience. Thus, for energy efficiency, tasks should be run just fast enough to meet the response-time requirement instead of wasting energy by running faster. In this paper, we present a predictive DVFS controller that predicts the execution time of a job before it executes in order to appropriately set the DVFS level to just meet user response-time deadlines. Our results show 56% energy savings compared to running tasks at the maximum frequency with almost no deadline misses. This is 27% more energy savings than the default Linux interactive power governor, which also shows 2% deadline misses on average.