Towards a High Level Approach for the Programming of Heterogeneous Clusters

摘要

The programming of heterogeneous clusters is inherently complex, as these architectures require programmers to manage both distributed memory and computational units with a very different nature. Fortunately, there has been extensive research on the development of frameworks that raise the level of abstraction of cluster-based applications, thus enabling the use of programming models that are much more convenient that the traditional one based on message-passing. One of such proposals is the Hierarchically Tiled Array (HTA), a data type that represents globally distributed arrays on which it is possible to perform a wide range of data-parallel operations. In this paper we explore for the first time the development of heterogeneous applications for clusters using HTAs. In order to use a high level API also for the heterogeneous parts of the application, we developed them using the Heterogeneous Programming Library (HPL), which operates on top of OpenCL but providing much better programmability. Our experiments show that this approach is a very attractive alternative, as it obtains large programmability benefits with respect to a traditional implementation based on MPI and OpenCL, while presenting average performance overheads just around 2%.