CRII: SHF: Optimizing Program Executions on Non-uniform Threaded Architectures

CRII：SHF：优化非均匀线程架构上的程序执行

• 批准号: 1464157
• 负责人: Xu Liu
• 金额: $ 17.5万
• 依托单位: College of William and Mary
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-03-01 至 2018-02-28
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1464157&HistoricalAwards=false
• 关键词: CRII; SHF; Optimizing; Program; Executions

Modern computer systems employ multiple threads to exploit multiple cores with multiple functional units. High thread-level parallelism arises from having multiple threads per core (simultaneous or fine-grained multithreading, SMT), multiple cores per processor (chip multithreaded processor, CMP), and multiple processors per node (non-uniform memory access, NUMA). Threads share different levels of hardware resources depending on where they execute. An architecture with hybrid SMT, CMP and NUMA threads is a non-uniform threaded architecture. Most multi-socket systems today are of this form. Due to the thread abstraction in operating systems and programming models, software developers often treat all threads in the system as symmetric, ignoring their non-uniformity in hardware. As a result, multithreaded code running on non-uniform threaded architectures performs at a level far below the theoretical peak, which can degrade productivity and increase energy consumption. The main focus of this project is to investigate both static and dynamic software methods to exploit non-uniformity between hardware threads. For the static optimization, the PI aims to introduce thread non-uniformity in software via code transformations. This will also include improving existing applications by identifying opportunities in application source code to apply such transformations. For the dynamic optimization, the PI plans to study online scheduling methods to match non-uniform threads in software and hardware. Given an executable, it will be analyzed online to characterize resource sharing between its threads and appropriate scheduling strategies will be applied for both threads and data. This project will tightly integrate static and dynamic optimization methods for programs running on non-uniform threaded architectures. This research can dramatically improve the performance of large-scale multithreaded applications running on today?s and emerging parallel architectures. More broadly, this project will have a strong impact in designing performance tools and parallel programming frameworks for non-uniform threads. It will likely attract broad interest from industry and academia. An important part of this project is its integration with teaching undergraduate and graduate courses as well as student mentoring.

现代计算机系统使用多个线程来利用具有多个功能单元的多个核心。高线程级并行性源于每个核心具有多个线程(同步或细粒度多线程，SMT)，每个处理器具有多个核心(芯片多线程处理器，CMP)，以及每个节点具有多个处理器(非一致内存访问，NUMA)。线程共享不同级别的硬件资源，具体取决于它们执行的位置。具有SMT、CMP和NUMA混合线程的体系结构是非统一线程体系结构。今天的大多数多插座系统都是这种形式。由于操作系统和编程模型中的线程抽象，软件开发人员经常将系统中的所有线程视为对称的，而忽略了它们在硬件上的不一致性。因此，在非统一线程体系结构上运行的多线程代码的执行水平远远低于理论峰值，这可能会降低生产率并增加能源消耗。这个项目的主要焦点是研究静态和动态的软件方法，以利用硬件线程之间的不一致性。对于静态优化，PI旨在通过代码转换在软件中引入线程不一致性。这还将包括通过在应用程序源代码中确定应用这种转换的机会来改进现有的应用程序。对于动态优化，PI计划研究在线调度方法，以匹配软、硬件上的非均匀线程。给定一个可执行文件，它将被在线分析以表征其线程之间的资源共享，并将对线程和数据应用适当的调度策略。该项目将紧密集成运行在非统一线程架构上的程序的静态和动态优化方法。这项研究可以极大地提高运行在当今的S和新兴的并行体系结构上的大规模多线程应用的性能。更广泛地说，该项目将在为非一致线程设计性能工具和并行编程框架方面产生强大的影响。它可能会吸引工业界和学术界的广泛兴趣。该项目的一个重要部分是与本科生和研究生课程的教学以及学生指导相结合。