Allocation cost minimization for periodic hard real-time tasks in energy-constrained DVS systems

Energy-efficiency and power-awareness for electronic systems have been important design issues in hardware and software implementations. We consider the scheduling of periodic hard real-time tasks along with the allocation of processors under a given energy constraint. Each processor type could be associated with its allocation cost. The objective of this work is to minimize the entire allocation cost of processors so that the timing and energy constraints are both satisfied. We develop approximation algorithms for processor types with continuous processor speeds or discrete processor speeds. The capability of the proposed algorithms was evaluated by a series of experiments, and it was shown that the proposed algorithms always derived solutions with system costs close to those of optimal solutions in the experiments.