An industrial deployment of a real time power aware scheduler

Feature content of modern mobile devices is increasing rapidly, followed by a soaring power consumption. We are forced to optimize for power consumption, which impacts design at both hardware and software level. The complexity of the problem increases when considering event driven real time systems where the CPU speed can affect temporal validity. We present an industrial implementation of a real time power aware scheduling algorithm on the Enea OSE operating system. Even sporadic tasks and workloads up to 100% can be scheduled, with significant power saving results. An additional run time mode is also introduced with reduced quality of service towards soft real time tasks, but without jeopardizing hard real time deadlines and further suppressing power consumption in battery critical situations.