Coordinating HPF programs to mix task and data parallelism

Experience in applicative fields, above all deriving from the development of multidisciplinary parallel applications, seems to suggest a model where art outer coordination level is provided to allow data parallel tasks to run concurrently and to cooperate each other. The inner computational level of this coordination model can easily be expressed with HPF, a high-level data-parallel language. According to this model, we devised COLT, s, a coordination architectural layer that supports dynamic creation and concurrent execution of HPF tasks, and permits these tasks to cooperate though message passing. This paper proposes the exploitation of COLTHPF by means of a simple skeleton-based coordination language and the associated source-to-source compiler. Differently from other related proposals, COLTHPF is portable and can exploit commercial, standard-compliant, HPF compilation systems. We used a physics application as a test-case for our approach, and we present the results of several experiments conducted on a cluster of Linux SMPs.