Scheduling unit tasks to minimize the number of idle periods: a polynomial time algorithm for offline dynamic power management

Power Management policies aim at reducing the amount of energy consumed by battery operated systems, while keeping the overall performance high. In this paper we focus on shut-down mechanisms that put a system into a sleep state when it is idle. A very small amount of energy is consumed in this state but, a fixed amount of energy is required when moving the system from the sleep state to the active state. The offline version of this problem consists in scheduling a set of unit execution tasks, with release dates and deadlines, on a single machine in order to minimize the number of idle time periods. We show that this problem can be solved in polynomial time by Dynamic Programming.