Rate-optimal scheduling for cyclo-static and periodic schedules

In order to realize DSP applications on multiprocessor systems with the optimal throughput, the properties and efficient techniques need to be derived. Rate-optimal scheduling with minimum unfolding has been studied in the past for static schedules only. The scheduling models called cyclo-static and periodic schedules allow more flexibility in processor assignment. This paper derives the minimum unfolding factors required to achieve rate-optimal schedules for cyclo-static and periodic schedules. The necessary and sufficient conditions for the existence of these schedules are also derived. From these results, it is shown that unfolding is necessary under these two models for certain data flow graphs to achieve rate-optimality. Furthermore, all the theorems are proved in a constructive way, in which an efficient shortest-path algorithm is used for scheduling