并行程序设计环境MPICH的应用机理分析

阐述了在PC集群中运用消息传递接口MPICH（Message Passing Interface and Chameleon）进行并行程序设计的基本方法，并以计算圆周率π值的并行算法程序为例，介绍了MPICH中基本例程的功能和调用方法，并行程序设计的关键技术是如何处理好各个进程之间的通信问题，MPICH采用紧迫协议和约定协议来协调各个进程之间的通信，同时也提供了一些阻塞处理函数和非阻塞处理函数，它们能够使进程充分利用系统资源，大大增加用户编程的灵活性。     

基于PC集群系统的MPICH大规模并行计算实现与应用研究

在Win2000 Server操作系统环境下采用MPICH并行技术，建立了基于PC局域网平台的并行集群系统，并通过VC 6．0调用消息传递库MPI函数完成了3个并行计算实例。符合MPICH规范的PC并行集群系统配置简便、系统稳定、界面友好、性价比高，能够持续利用计算机现有资源和大幅度提高计算效率。     

机群系统LogP通信模型的测试与分析

本文形式化描述并发展了通信Microbenchmark技术，并在这种技术的基础上，比较系统地测试了机群系统上四种并行通信系统－－GM－API、基于100M以太网的MPICH，基于Myrinet网络的MPICH和GM－MPI－－的表征通信性能的LogP参数，并通过比较，得出四种并行通信系统特点优劣关系，最后，给出了各个通信系统对不同的并行应用的适用情况。     

一种优化MPI程序性能的改进方法

在分布式存储系统上,MPI已被证实是理想的并行程序设计模型。MPI是基于消息传递的并行编程模型,进程间的通信是通过调用库函数来实现的,因此MPI并行程序中,通信部分代码的效率对该并行程序的性能有直接的影响。通过用集群通信函数替代点对点通信函数以及通过派生数据类型和建立新通信域这两种方式,两次改进DNS的MPI并行程序实现,并通过实验给出一个优化MPI并行程序的一般思路与方法。     

对MPICH作业提交方法的改进和验证

MPI(Message Passing Interface)是大规模集群和网格平台中最通用的编程环境,而MPICH是其中应用得最广的一种可移植的实现.在集群式系统中,通信时间取决于许多因素,如节点数、网络带宽、拓扑结构还有软件算法等.到目前为止关于程序层面上的通信模式被研究得很多,以期达到提高通信效率的目的,但是MPICH系统内部所需要的通信时间特别是作业提交过程所花费的时间往往为人们所忽略.分析了当前MPICH的作业提交方法,并提出了同步二叉树法、异步二叉树法和二倍扩散法等一系列改进算法,达到了减少通信时间,优化通信性能的目的.     

LabWindows/CVI下测控串行通信的实现方法

串行通信以其技术简单成熟、性能可靠而在测控系统中得到广泛应用。主要介绍了LabWindows/CVI环境下串口通信的实现技术,首先简要介绍了几种常用的通信实现方式,然后着重对LabWindows/CVI 7.0下实现串口通信的两种方法进行了详细介绍,分别为API方式和库函数方式。API方式实现灵活、应用范围广,但原理复杂,而库函数方式实现简单,并有强大的函数库支持,可有效提高系统的设计效率。对主要的编程函数进行详细说明,并给出了关键程序的实现代码。     

集群系统中BSP模型上的并行FFT设计

在并行计算模型中，BSP模型由于具有编程简单、独立于体系结构和执行性能可预测等特点而在总体上优于其它模型。NOWs正成为并行计算领域的一个新的发展热点，以太网构成的微机集群系统是NOWs的一种重要实现形式。文中研究了集群系统中BSP模型上的并行算法设计，以FFT算法为例，进行了设计和分析，并给出了测试结果。     

基于RapidIO的单边通信接口的设计与实现

随着MPI 2的发布,单边通信越来越受到广泛的关注.集群系统中单边通信将是一个重要的发展方向,由IBM研制的Blue Gene/L系统就是一个典型例子.在PowerPC架构上实现了一种基于RapidIO的单边通信接口,为下一步与MPICH2的连接实现迈出了重要一步.基于RapidIO的单边通信接口,将使整个网络达到低开销、高带宽和低延时,集群系统的性能也必将得到极大的提高.     

MPICH作业提交方式的研究及改进

通过对MPICH作业提交方式的研究,进而优化作业的提交过程,提出了一种SBM方法,即一种新的作业提交方式,减少了通信的时间,得到更高的通信性能,实现了对MPICH作业提交方式的改进。设计并实现了基于SBM方法的MPICH系统,并与采用传统方法的系统进行了性能对比,证明了在大型并行计算中,基于SBM作业提交方式可以得到更好的通信性能。     

基于TMS320C54x系列DSP的卷积处理的实现

卷积是数字信号处理中最基本、最常用的运算之一。本文介绍了利用TMS320C54x系列芯片为基础的DSPLIB库函数中的相关函数和FFT函数来实现数季卷积处理的两种方法，使卷积运算的实现变得容易，并对DSPLIB库函数的使用进行了详细介绍，给出了具体的程序清单和实验结果。     

Comparing the performance of MPICH with Cray's MPI and with SGI's MPI

The purpose of this paper is to compare the performance of MPICH with the vendor Message Passing Interface (MPI) on a Cray T3E‐900 and an SGI Origin 3000. Seven basic communication tests which include basic point‐to‐point and collective MPI communication routines were chosen to represent commonly‐used communication patterns. Cray's MPI performed better (and sometimes significantly better) than Mississippi State University's (MSU's) MPICH for small and medium messages. They both performed about the same for large messages, however for three tests MSU's MPICH was about 20% faster than Cray's MPI. SGI's MPI performed and scaled better (and sometimes significantly better) than MPICH for all messages, except for the scatter test where MPICH outperformed SGI's MPI for 1 kbyte messages. The poor scalability of MPICH on the Origin 3000 suggests there may be scalability problems with MPICH. Copyright © 2003 John Wiley & Sons, Ltd.     

Performance analysis and optimization of MPI collective operations on multi-core clusters

Memory hierarchy on multi-core clusters has twofold characteristics: vertical memory hierarchy and horizontal memory hierarchy. This paper proposes new parallel computation model to unitedly abstract memory hierarchy on multi-core clusters in vertical and horizontal levels. Experimental results show that new model can predict communication costs for message passing on multi-core clusters more accurately than previous models, only incorporated vertical memory hierarchy. The new model provides the theoretical underpinning for the optimal design of MPI collective operations. Aimed at horizontal memory hierarchy, our methodology for optimizing collective operations on multi-core clusters focuses on hierarchical virtual topology and cache-aware intra-node communication, incorporated into existing collective algorithms in MPICH2. As a case study, multi-core aware broadcast algorithm has been implemented and evaluated. The results of performance evaluation show that the above methodology for optimizing collective operations on multi-core clusters is efficient.     

The dance party problem and its application to collective communication in computer networks

Motivated by implementing collective communication operations on workstation clusters, a problem of scheduling a dance party is formulated. The problem is solved by two algorithms based on searching and divide-and-conquer that generate suboptimal schedules and an algorithm based on graph factorization that generates optimal schedules. It is shown how to use dance schedules to implement collective communication operations such as all—gather. Experiment data on a single ethernet segment of SUN SPARC-10 workstations and on a switch connected network, the IBM SP2, show that the all—gather implementation that simply uses the optimal schedule performs better for long messages than the implementations of system MPL from IBM and public-domain systems LAM and MPICH/p4.     

KD60集群消息传递接口群集通信算法优化

大规模集群已经发展到多核的时代,多核架构对并行计算提出了新的要求。消息传递接口(MPI)是最常用的并行编程模型,而群集通信又是MPI中的重要组成部分。研究高效的群集通信算法对并行计算效率的提升有着重要的作用。KD60平台是采用首款国产多核芯片——龙芯3号搭建的国产万亿次多核集群。首先分析了KD60平台多核集群的体系特征以及多核架构下通信具有的层次性特征;然后分析原有群集通信算法实现原理及其不足;最后以广播为例,在原有算法基础上,采用一种基于片上多核(CMP)架构改进算法,改变原有算法通信模式,同时结合实验平台KD60体系特征,对算法做了体系相关优化。实验结果表明,改进算法能够很好地利用多核结构的特点,提高了群集通信广播算法的性能。     

基于天河互连MPI聚合通信归约操作卸载优化

MPI collective communication operation is widely used in parallel scientific application, which has an important influence impact on the scalabilityof the program. Tianhe interconnect network supports the trigger communication operations, which can offload the messaging and processing work and improve the performance between nodes. Allreduce and Reduce algorithms under different tree topological structures are designed by using thetriggered operations to lower the latency the reduction operation communication between nodes. Tests based on the actual system platform show that that, compared with the point to point implementation of these two types of operations in MPICH, the offload algorithm based on trigger can reduce the running time by up to 59.6% at different node scales.     

Collective communication: theory,practice, and experience

We discuss the design and high‐performance implementation of collective communications operations on distributed‐memory computer architectures. Using a combination of known techniques (many of which were first proposed in the 1980s and early 1990s) along with careful exploitation of communication modes supported by MPI, we have developed implementations that have improved performance in most situations compared to those currently supported by public domain implementations of MPI such as MPICH. Performance results from a large Intel Xeon/Pentium 4 (R) processor cluster are included. Copyright © 2007 John Wiley & Sons, Ltd.     

A high-performance MPI implementation on a shared-memory vector supercomputer

In this article we recount the sequence of steps by which MPICH, a high-performance, portable implementation of the Message-Passing Interface (MPI) standard, was ported to the NEC SX-4, a high-performance parallel supercomputer. Each step in the sequence raised issues that are important for shared-memory programming in general and shed light on both MPICH and the SX-4. The result is a low-latency, very high bandwidth implementation of MPI for the NEC SX-4. In the process, MPICH was also improved in several general ways.     

随机模式匹配并行算法在工作站机群上的实现

对随机模式匹配算法进行了改进,并根据MPICH并行编程环境中任务间通信的特点,设计了一种基于MPICH的改进的随机模式匹配并行算法。根据运行在COW（工作站机群）上的进程数目将文本串进行重叠划分,每个进程完成一个文本子串的模式匹配。实验结果表明,该改进的随机模式匹配并行算法有效地加快了模式匹配的速度,提高了工作站机群的资源利用率。     

并行程序设计环境的研究

MPI(MessagePassingInterface)是目前一种比较著名的应用于并行环境的消息传递标准。MPICH是MPI1.2标准的一个完全实现,也是应用范围最广的一种并行及分布式环境。MPICH除包含MPI函数库之外,还包含了一套程序设计以及运行环境。本文将简要介绍如何应用MPICH的Windows版本,建立一个基于Windows的并行程序设计及运行环境。