适合机群OpenMP系统的制导扩展

OpenMP以其易用性和支持增量并行的特点成为共享存储体系结构的编程标准．机群OpenMP系统在机群上实现了OpenMP计算环境，它将OpenMP的易编程性和机群的可扩展性结合起来，是很有意义的．OpenMP的编程方式主要有循环级和SPMD两种，其中循环级方式易于编程而SPMD方式难于编程．然而在机群OpenMP系统中获得高性能OpenMP程序，必需采用SPMD方式．该文描述了适合机群OpenMP系统的一个简单的OpenMP制导扩展子集(包括数据分布制导、循环调度模式)，并在机群OpenMP系统OpenMP／JIAJIA上进行了实现．应用测试表明，利用这些制导扩展进行编程，既保持循环级方式的易编程性又获得与SPMD方式相当的性能，是有效的编程方式．

Directive Extensions of OpenMP System Based on Cluster

The OpenMP Application Programming Interface (API) is an emerging standard for parallel programming on shared memory multiprocessors because of its ease of use and incremental approach to the parallelization of sequential programs. At present, clusters of workstations or PCs have been becoming the mainstream platform for high performance computing. It is increasingly attractive to develop OpenMP system based on cluster which combines the programmability of OpenMP with scalability of cluster. The OpenMP program could be written in both loop-level parallel style and SPMD style. The SPMD style is not easy to program while the loop-level style is easy. Unfortunately, it is necessary to program in SPMD style for high performance on OpenMP system based on cluster. In this paper, some directive extensions have been illustrated, such as data distribution directive, new loop schedule scheme, etc. and these directive extensions have been implemented on our OpenMP system based on cluster named OpenMP/JIAJIA. Experimental results show that the performance of programs' version written in these directive extensions is as good as the version written in SPMD style while the programmability is as good as loop-level style. So it is an effective programming style to program in these directive extensions on OpenMP system based on cluster.