COLT HPF , a Coordination Layer for HPF Tasks

This paper describes COLTHPF, a run{time support for the coordination of concurrent and communicating HPF tasks. COLTHPF is conceived for use by a compiler of a high-level coordination language to structure a set of data-parallel HPF tasks according to popular forms of task-parallelism, but it can also be exploited to implement libraries of skeletons. Since it requires only small changes to the run-time support of the HPF compiler used, COLTHPF is easily portable among diierent compilation systems. The paper outlines design and implementation issues, and discusses the main diierences from other approaches proposed to exploit task parallelism in the HPF framework. We show how COLTHPF can be used to implement common forms of parallelism, e.g. pipeline and processor farms, and we present experimental results regarding both synthetic micro-benchmarks and sample applications. The experiments were conducted on an SGI/Cray T3E using Adaptor, a public domain HPF compiler.