An Integrated Compiler-Runtime Approach to Software Distributed Shared Memory

这项研究工作集中在支持软件分布式共享内存(DSM)的集成编译器-运行时方法上。其目标是在为用户提供共享内存编程模型的同时，获得接近手动调优的消息传递程序的性能。这项工作主要针对“工作站网络”，但也适用于IBM SP-2这样的专用分布式内存机。尽管软件DSM系统的设计和实现在过去几年中取得了进步，但消息传递仍然是用于对分布式存储机器进行编程的最常用的方法，因为消息传递系统通常比DSM系统执行得更好。该方案通过构建一个集成的编译器-运行时DSM系统来解决这一问题，包括通过编译器分析来优化显式并行共享内存程序。具体地说，编译器预测访问模式的能力，而不是像运行时系统那样仅对它们做出反应的能力，将允许预取和聚合消息，并将避免不必要的数据移动和一致性操作。这项工作将基于莱斯开发的踏板DSM系统。拟议的工作将有助于更好地利用工作站网络，更广泛地说，利用分布式存储机器进行并行计算。早期关于踏步标记的工作已经为这一目标做出了贡献，因为它已经为DSM创造了最先进的运行时系统之一，其他研究人员已经在计算遗传学、混合整数编程和地震建模方面使用了该系统。***

This research effort focuses on an integrated compiler-runtime approach to support software distributed shared memory (DSM). The goal is to achieve performance close to hand-tuned message passing programs while still presenting the user with a shared memory programming model. The work is primarily directed towards "networks of workstations", but it is also applicable to dedicated distributed memory machines like the IBM SP-2. Notwithstanding advances in the design and implementation of software DSM systems over the last few years, message passing has remained the most commonly used method for programming distributed memory machines, because message passing systems, in general, perform better than DSM systems. This proposal addresses this issue by building an integrated compiler-runtime DSM system, including the optimization of explicitly parallel shared memory programs through compiler analysis. Specifically, the ability of the compiler to predict access patterns, rather than merely react to them as the runtime system does, will allow prefetching and aggregation of messages, and will avoid unnecessary data movement and consistency actions. The work will be based on the TreadMarks DSM system developed at Rice. The proposed work will contribute to the better utilization of networks of workstations and, more generally, distributed memory machines for parallel computing. Earlier work on TreadMarks has already contributed to that goal, in that it has produced one of the most advanced runtime systems for DSM, that has been used by other researchers for work in computational genetics, mixed integer programming, and seismic modeling. ***