CSR-EHS: Integrated Memory Allocation and Scheduling for Real-Time Embedded Systems

CSR-EHS：实时嵌入式系统的集成内存分配和调度

• 批准号: 0720797
• 负责人: Alexander Dean
• 金额: $ 18万
• 依托单位: North Carolina State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-08-01 至 2012-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0720797&HistoricalAwards=false
• 关键词: CSR; EHS; Integrated; Memory; Allocation

Many of the conveniences of modern life are made possible by embedded computing systems. This project is developing new methods to make such systems use their limited resources more efficiently, increasing performance, reducing costs and energy requirements. Modern general-purpose computers (PCs, servers, etc.) owe most of their high processing speed to caches. These memory system components fetch data from the slow (but inexpensive) main memory for the fast processor before it even realizes it needs it. Unfortunately the performance offered by caches is very difficult to guarantee, greatly complicating the prediction of a program's worst-case performance. This prediction is essential for a broad class of embedded and control systems ? those with real-time requirements. Such systems must respond to inputs before a deadline elapses or else something will fail. Hence such systems must be over-provisioned to cover the ?margin of ignorance?, raising costs and energy requirements.This project is developing methods to provide memory accesses as fast as with a cache, but without any of the timing uncertainty, making this technology suitable for real-time systems. The research team uses a unified approach which cuts across compilers, operating systems, and computer architecture to create a much more efficient solution than possible by considering the problems separately. The fundamental insight is that by limiting preemption among threads, one can reduce the total memory required, allowing more data to be stored in fast memory. This speeds thread execution, allowing further reduction of preemptions (and hence memory requirements) leading to a repeatable, virtuous cycle.

现代生活的许多便利都是通过嵌入式计算系统实现的。 该项目正在开发新方法，使此类系统更有效地利用其有限的资源，提高性能，降低成本和能源需求。现代通用计算机（PC、服务器等）的高处理速度大部分归功于缓存。这些内存系统组件在快速处理器意识到需要数据之前就从慢速（但廉价）的主内存中获取数据。不幸的是，缓存提供的性能很难保证，这使得程序最坏情况性能的预测变得非常复杂。这一预测对于广泛的嵌入式和控制系统至关重要？有实时性要求的。此类系统必须在截止日期之前对输入做出响应，否则某些事情将会失败。 因此，此类系统必须过度配置以覆盖“无知边际”，从而提高成本和能源需求。该项目正在开发提供与缓存一样快的内存访问的方法，但没有任何时序不确定性，从而使该技术成为可能适合实时系统。研究团队使用一种跨编译器、操作系统和计算机体系结构的统一方法来创建比单独考虑问题更有效的解决方案。 基本原理是，通过限制线程之间的抢占，可以减少所需的总内存，从而允许在快速内存中存储更多数据。这可以加快线程执行速度，从而进一步减少抢占（从而减少内存需求），从而实现可重复的良性循环。