Getting the Best Response for Your Erg

We consider the bi-criteria problem of minimizing the average flow time (average response time) of a collection of dynamically released equi-work processes subject to the constraint that a fixed amount of energy is available. We assume that the processor has the ability to dynamically scale the speed at which it runs, as do current microprocessors from AMD, Intel, and Transmeta. We first reveal the combinatorial structure of the optimal schedule. We then use these insights to devise a relatively simple polynomial time algorithm to simultaneously compute, for each possible energy, the schedule with optimal average flow time subject to this energy constraint