DCS: Delayed Finalization of MPI Collective Communication Routines

消息传递接口（MPI）的标准化导致了大量基于MPI的并行应用程序的开发。为了使这些应用程序达到高性能，MPI库有效地实现通信至关重要。尽管MPI性能优化已经取得了一定的进展，但目前MPI集体通信例程的实现还很不理想，为了使MPI集体通信例程在不同的平台上实现高性能，它们必须能够适应不同的系统架构，并在不同的情况下使用不同的算法。在于促进库例程适应给定系统/应用配置并找到用于该配置的最有效算法的机制。智力优势PI建议使用一种技术，他称之为MPI集体编译例程的延迟完成（DFoMCCR），以提高MPI库中的软件适应性。支持DFoMCCR的系统有两个关键组件：（1）包含在不同情况下可以潜在地实现高性能的不同算法的算法库，（二）一种自动算法选择机制，用于确定例程中要使用的算法。延迟的最终化可能会使体系结构和应用程序特定的优化被在图书馆的例行程序中执行。一个支持DFoMCCR的系统可以大大超过传统的MPI库。PI将通过开发各种支持DFoMCCR的库系统来研究DFoMCCR和促进DFoMCCR的机制。该计划是实现一个算法库，其中包含广泛的拓扑/系统不知道和拓扑/系统特定的算法，共同MPI集体communication operations.Broader的影响，有效的集体通信实现新的图书馆，提高性能的MPI应用程序，这将有利于一个非常广泛的科学和工程社区，使用MPI来解决问题。- 这些库的可用性也将有利于MPI研究社区。该项目将在这一领域培养一批本科生和研究生。- 所开发的一些技术将纳入研究生和本科生选修课程。

BackgroundThe standardization of Message Passing Interface (MPI) has resulted in the development of a large number of MPI based parallel applications. For these applications to achieve high performance, it is crucial that the MPI library realizes communication efficiently. While progress has been made in optimizing MPI performance, the current implementations of MPI collective communication routines are far from ideal.For MPI collective communication routines to achieve high performance on different platforms, they must be able to adapt to the system architecture and use different algorithms in different situationsThe main challenge therefore, lies in the mechanism to facilitate a library routine to adapt to a given system/application configuration and to find the most efficient algorithm for the configuration. Intellectual MeritThe PI proposes to use a technique, which he will call delayed finalization of MPI collectivecommunication routines (DFoMCCR), to improve the software adaptability in MPI libraries.A system that supports DFoMCCR has two key components:(1) an algorithm repository that contains different algorithms that can potentially achieve high performance at different situations,(2) an automatic algorithm selection mechanism to determine the algorithms to be used in a routine.The delayed finalization potentially allows architecture and application specific optimizations to be performed on the library routines. A system that supports DFoMCCR can significantly out-perform traditional MPI libraries.The PI will investigate DFoMCCR and mechanisms to facilitate DFoMCCR by developing various library systems that support DFoMCCR. The plan is to implement an algorithm repository that contains extensive sets of topology/system unaware and topology/system specific algorithms for common MPI collective communication operations.Broader Impact-efficient collective communication implementations obtained from the new libraries-improved performance of MPI applications, which will benefit a very broad science and engineering community that uses MPI to solve problems. -availability of these libraries will also benefit the MPI research community.-project will train a number of undergraduate and graduate students in this area. -Some techniques developed will be included in graduate and undergraduate elective courses.