Software distributed shared memory systems with performance scalability for supercluster systems

针对超级集群系统的实用性，实现了一个性能可扩展的高性能软件分布式共享内存系统MochA。当前版本的Mocha在Linux环境的32节点集群上运行。源程序已通过Web在公共领域中开放。提出了一种抑制通信开销的方案，该方案主要由维护分布在分布式存储器中的共享数据之间的数据一致性引起，并在MOCHA中实现。通过一些基准程序对其有效性进行了评估。实现了一个应用程序性能调试和构造高效软件需求侧管理工具S猫，该工具具有直观地显示应用程序执行过程中处理器间通信轨迹的功能。将S-Cat用于MOCHA的高效实现和应用程序的性能调优。主要研究成果如下：1.实现了一个低通信开销的软件DSM-MOCHA。2.对同一集群上不同软件DSM进行了比较研究。3.提出了在软件DSM上进行粗粒度并行处理的建议4.构建了一个软件DSM可视化工具S-CAT。有人提出了控制多个集群的“层级范式”，但其有效性在本研究期间无法得到验证。

A high-performance software distributed shared memory (DSM) system with performance scalability, named Mocha, was implemented as an experimental prototype aiming at the usefulness of supercluster systems. The current version of Mocha works on a 32 node cluster on the Linux environment. The source program has been opened in public domain via web. A scheme for suppressing communication overhead, which is mainly caused by maintaining data consistency among shared data located at distributed memories, is proposed and slotted in Mocha. The effectiveness is evaluated by using some benchmark programs. A tool for performance debugging of application programs and constructing an efficient software DSM, named S-Cat, was implemented, which has such functions as showing visually communication locus among processors during execution process of an application program. S-Cat was used in efficient implementation of Mocha and performance tuning of application programs on Mocha.The main research results are as follows:1.Implementation of a low communication overhead software DSM, named Mocha2.Comparison study of different software DSMs on the same cluster3.Proposal of coarse-grain parallel processing on software DSM4.Construction of a visualization tool for software DSM, named S-Cat5.Proposal of parallel processing on graphic processor and off-the-shelf processorSome technical issues toward realization of high-performance software DSMs for supercluster systems are made clear. "Hierarchical paradigm" for controlling multiple clusters was proposed, but its usefulness cannot be verified during this research period.