Stream parallel skeleton optimization

We discuss the properties of the composition of stream parallel skeletons such as pipelines and farms. By looking at the ideal performance figures assumed to hold for these skeletons, we show that any stream parallel skeleton composition can always be rewritten into an equivalent "normal form" skeleton composition, delivering a service time which is equal or even better to the service time of the original skeleton composition, and achieving a better utilization of the processors used. The normal form is defined as a single farm built around a sequential worker code. Experimental results are discussed that validate this normal form.