CSR-EHS: Memory management as a run-time service

CSR-EHS：内存管理作为运行时服务

• 批准号: 0720683
• 负责人: Rajeev Barua
• 金额: $ 18万
• 依托单位: University of Maryland, College Park
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-08-01 至 2011-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0720683&HistoricalAwards=false
• 关键词: CSR; EHS; Memory; management; run

SRAM memories are essential to improving run-time, energy use and real-time bounds. Many embedded processors contain Scratch Pad Memory (SPM), unenhanced SRAM that is mapped to a portion of the address space. They offer better real-time guarantees than caches, an alternate SRAM memory type. Compiler methods to allocate objects automatically to SPM have existed for a decade, but a recent survey did not find even a single commercial compiler that does automatic SPM allocation. Instead, programmers manually specify the SPM allocation using annotations. Reasons may include developer unawareness of SPM, unwillingness to include another feature in the toolchain, and the expense of repeated implementation in each compiler. This research is developing a SPM allocation strategy that is completely implemented inside a binary rewriter. This binary rewriter is called automatically by the operating system the first time the program is loaded to memory. Subsequent executions derive the benefits of SPM with no additional overhead. This approach makes SPM a run-time-provided resource for the first time, much like cache and virtual memory are, making it ubiquitous and transparent to the software toolchain. The broader impacts of the research are (i) embedded systems that achieve high speed and real-time behavior at lower cost; (ii) portable devices with lower energy use, hence longer battery life; (iii) programs that are portable to any SPM size ? an important practical advantage; (iv) an educational and outreach program including graduate student training, undergraduate and graduate courses, internships, and a workshop on memory management.

SRAM存储器对于改善运行时间、能源使用和实时边界至关重要。许多嵌入式处理器包含暂存存储器（SPM），即映射到地址空间一部分的未增强SRAM。它们提供了比高速缓存更好的实时保证，高速缓存是一种替代的SRAM存储器类型。将对象自动分配给SPM的更好的方法已经存在了十年，但是最近的一项调查甚至没有发现一个商业编译器可以自动分配SPM。相反，程序员使用注释手动指定SPM分配。原因可能包括开发人员不了解SPM，不愿意在工具链中包含另一个功能，以及在每个编译器中重复实现的费用。这项研究正在开发一种SPM分配策略，完全实现在二进制重写器。当程序第一次加载到内存时，操作系统会自动调用此二进制重写器。后续的执行可以在不增加额外开销的情况下获得SPM的好处。这种方法使SPM第一次成为运行时提供的资源，就像缓存和虚拟内存一样，使其无处不在，对软件工具链透明。更广泛的影响的研究是（一）嵌入式系统，实现高速和实时的行为，以较低的成本;（二）便携式设备与较低的能源使用，因此更长的电池寿命;（三）程序，可移植到任何SPM大小？重要的实用优势;（iv）教育和外展计划，包括研究生培训、本科生和研究生课程、实习和记忆管理工作坊。