Multiprocessor scheduling of a signal flow graph for workstation clusters

A multiprocessor code generator for workstation clusters is developed to prototype DSP (digital signal processing) algorithms represented by hierarchical signal flow graphs quickly. In order to reduce the communication overhead and utilize fairly large memory space in each workstation, the parallel block processing method which assigns one block of data to each processor in rotation is used. Firstly, a signal flow graph is scheduled in a higher hierarchy level with coarse grain partitioning. If the desired performance is not obtained, a finer grain scheduling is performed in the lower hierarchy. An MPEG2 audio encoder program is implemented in real time for the IBM SP2 parallel computer using the PVM message passing library as an example.