Research on Distributed Shared Memory System with High Speed Network

近年来，工作站和网络的CPU在性能上取得了长足的进步，将连接高速商用网络的工作站集群作为虚拟并行计算机已被公认为是有用的。本课题的研究目标是构建一个共享内存系统作为工作站集群的编程环境。普通的消息传递接口需要程序员付出相当大的努力。如果在工作站集群上构建虚拟共享内存系统，编程人员看到的是单个内存地址空间，并行编程的复杂性大大降低。在这个项目中，我们实现了一个软件分布式共享内存系统（DSM），它具有很高的软件可移植性。在我们的设计中，使用PVM作为网络接口，使用Split-C编程语言模型(I)实现软件DSM。与硬件DSM不同，软件DSM必须付出相当大的性能代价，我们设计了一个软件缓存系统作为运行库，并成功地提高了软件DSM的性能（II）。缓存系统是一个基于Read-Only cache的比较简单的系统，在我们的实验（III）中获得了比较合理的性能。利用INSPEC数据库对DSM的研究活动进行了趋势分析，并对并行编程语言系统的理论研究进行了探讨。

In recent years CPU of workstations and networks have made a rapid progress in performance, and it is now recognized useful to use clusters of workstations connected with high speed commodity network as virtual parallel computers. The objective of this research project is construction of a shared memory system as the programming environment of workstation cluster. The ordinary message passing interface requires considerable efforts of programmers. If we construct a virtual shared memory system on clusters of workstations, the programmer sees a single memory address space and complexity of parallel programming is reduced greatly. In this project we have implemented a software distributed shared memory system(DSM) which has high software portability. In our design PVM is used the network interface and software DSM is implemented with the Split-C programming language model(I). Different from the case of hardware DSMs, software DSM must pay a considerable performance penalties and we devised a software cache system as the runtime library and succeeded in improving performance of software DSM (II). The cache system is a rather simple system based on Read-Only Cache and a reasonable performance was attained in our experiments(III). We carried out trend analysis of research activities in DSM using INSPEC database and also investigated theoretical study in parallel programming language systems.