Experimental Software Systems: A Parallel Message-Passing Platform for Atomic Structure Calculations

9806521Apon，Amy W.Fischer，Charlotte F.Vanderbilt University实验软件系统：一个用于原子结构计算的并行消息传递平台这个项目是对一种以前未测试的网络接口类型的实验和分析研究，作为用于计算原子结构数据的工作站集群的互连。例如，最近对硼的电子亲和力的预测计算得出了一个答案，促使人们对一个硼原子进行了新的实验测量。然而，对于较大的原子来说，这样的精度可能会带来相当大的计算挑战。正在研究的硬件平台是与包含用户级可访问存储器的网络接口互连的工作站集群。每个节点在网络接口中都有内存，可用于缓存共享数据，并且可由任何节点读取或写入。主要工作是(1)提出使用网络接口存储器作为选定共享数据的存储库的原子结构计算的修改；(2)通过分析和实验来评估使用共享缓冲区和零拷贝消息进行原子结构计算的有效性，并评估诸如存储器分区技术、数据和线程放置等权衡；以及(3)提出将这些实验结果推广用于其他科学代码的建议。

9806521Apon, Amy W.Fischer, Charlotte F. Vanderbilt UniversityExperimental Software Systems: A Parallel Message-Passing Platform for Atomic Structure CalculationsThis project is an experimental and analytic investigation of a previously untested type of network interface as the interconnect of a cluster of workstations for the calculation of atomic structure data. As an example, recent calculations for the prediction of the electron affinity of boron yielded an answer that spurred new experimental measurements of a boron atom. However, such accuracy for larger atoms may present a considerable computational challenge. The hardware platform being studied is a cluster of workstations interconnected with a network interface that contains user-level accessible memory. Each node has memory in the network interface that can be used to cache shared data, and that may be read or written by any node. Primary efforts are to (1) propose modifications to the atomic structure calculation that use network interface memory as a respository for selected shared data, (2) evaluate via analysis and experimentation the effectiveness of using shared buffers and zero-copy messaging for atomic structure calculations, and evaluate tradeoffs such as memory partitioning techniques and data and thread placement, and (3) propose generalizations of these experimental results for use in other scientific code.It is expected that investigations will lead to a new proposal for an implementation of large atomic structure calculations with better performance.