DCS: Delayed Finalization of MPI Collective Communication Routines

背景消息传递接口(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库高效地实现通信是至关重要的。虽然在优化MPI性能方面已经取得了一些进展，但目前的MPI集合通信例程的实现还远远不够理想。为了使MPI集合通信例程在不同的平台上获得高性能，它们必须能够适应系统架构并在不同的情况下使用不同的算法。因此，主要的挑战在于如何帮助库例程适应给定的系统/应用配置，并找到最有效的配置算法。智能优点PI建议使用一种技术，他将其称为MPI集合通信例程的延迟完成(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)包含可能在不同情况下获得高性能的不同算法的算法库，(2)自动算法选择机制，以确定要在例程中使用的算法。延迟完成潜在地允许对库例程执行特定于体系结构和应用的优化。一个支持DFoMCCR的系统可以显著地超越传统的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。该计划将实施一个算法存储库，其中包含用于常见MPI集体通信操作的大量拓扑/系统未知和特定于拓扑/系统的算法。广泛的影响-高效的集体通信实施-从新的库中获得-提高MPI应用程序的性能，这将使使用MPI解决问题的非常广泛的科学和工程社区受益。-这些图书馆的提供也将使MPI研究界受益。-该项目将在这一领域培训一些本科生和研究生。-开发的一些技术将包括在研究生和本科生的选修课中。

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.