CSR: Small: Collaborative Research: Transparent and Energy-Efficient Speculation on NUMA Architectures for Embedded Multiprocessor Systems

高端嵌入式系统正在转向多核架构，以满足其应用程序所需的性能和性能/瓦特要求。此外，随着嵌入式系统对更多计算密集型功能的需求增加，这些多核架构将演变成多核系统，以提高性能或性能/面积/瓦特。这些系统通常组织为基于集群的非统一内存访问（NUMA）体系结构，为程序员提供共享内存抽象。也就是说，简单的核心被分组到共享本地互连和内存的集群中，然后使用可扩展的片上网络介质对这些集群进行复制和互连。本项目研究这些新兴的嵌入式系统NUMA架构所带来的主要挑战之一：为同步和通信提供高效、节能和方便的机制。特别是，它提出了基于硬件支持投机同步的新解决方案，以及基于软件支持使投机透明的新解决方案。衡量解决方案有效性的重要指标包括吞吐量、易用性、系统能耗和架构简单性。嵌入式系统在广泛的应用中变得无处不在，包括智能手机、汽车系统、安全和其他环境智能系统。不断增长的计算需求导致了更复杂的产品，因此在满足严格的设计限制方面的挑战也增加了，特别是吞吐量/瓦特。对这些系统通信和同步数据方式的改进可以在改进的功能、实用程序和持久性方面产生重大影响。该项目是一项国际合作，结合了PI在片上网络架构、嵌入式系统设计和内存同步方面的专业知识。该提案的更广泛影响包括新课程的开发，向研究生和本科生女性以及未被充分代表的少数民族提供服务，以及国际机构之间的学生交流。

High-end embedded systems are turning to multicore architectures to meet the performance, and performance/Watt, demands required for their applications. Moreover, as the demand for more compute-intensive capabilities for embedded systems increases, these multicore architectures will evolve into many-core systems for improved performance or performance/area/Watt. These systems are often organized as cluster-based Non-Uniform Memory Access (NUMA) architectures that provide the programmer with a shared-memory abstraction. That is, simple cores are grouped into clusters sharing local interconnection and memory and these clusters are then replicated and interconnected using a scalable network-on-chip medium. This project investigates one of the principal challenges presented by these emerging NUMA architectures for embedded systems: providing efficient, energy-effective, and convenient mechanisms for synchronization and communication. In particular, it proposes new solutions based on hardware support for speculative synchronization, and software support to make such speculation transparent. Important metrics for measuring the effectiveness of the solutions include throughput, ease of use, system energy consumption, and architectural simplicity. Embedded systems are becoming ubiquitous over a broad range of applications, including smart phones, automotive systems, security, and other ambient intelligence systems. Increasing computational demands have led to more sophisticated products and therefore increased challenges in meeting tight design constraints, particularly throughput/Watt. Improvements to the way these systems communicate and synchronize data can have a substantial impact in terms of improved functionality, utility, and durability. The project is an international collaboration that combines PI expertise in Network-on-Chip architectures, embedded system design, and memory synchronization. Broader impacts of the proposal include new course development, outreach to graduate and undergraduate women and under-represented minorities, and student exchanges between international institutions.