Enabling Circuit Switching with Compiler and Run-time Analysis for High Performance Systems

光学设备和互连的进步使这项技术对电信和高性能系统具有吸引力。具体地说，大型光开关在商业上是可用的，但还没有实用技术可用于光域中的缓冲或处理。因此，尽管电子分组交换和虫洞路由的成本较高、带宽有限、消息延迟增加，但它们仍然很受欢迎。在该项目中，研究人员提出使用电路交换作为分组和虫洞交换的有效替代方案，以在高性能并行系统中实现高带宽、低延迟的通信。具体地说，通过在通信进程之间建立直接管道，可以消除中间交换机上的路由和缓冲，可以简化端到端协议，并且可以最大限度地减少与数据移动相关的软件和硬件开销。然而，建立电路的开销可能相对较大，只有当通信表现出局部性并且适当地探索了该局部性时，电路交换的好处才能超过其缺点。为此，提出了一种基于编译器的并行应用程序通信局部性分析方法。该方法将通信局部性暴露给一个体系结构，该体系结构通过管理电路交换互连的运行时系统来探索通信局部性。作为本研究的一部分开发的用于检测和操作通信模式的新的编译器技术使高性能超级计算机之外的多个领域能够实现并行，包括芯片多处理器系统和无线系统。通过将代码结构与通信模式相关联，建议的编译器技术还允许构建工具，以帮助应用程序开发人员编写更高效的程序。此外，该项目通过将该项目的研究整合到计算机工程课程和设计项目中，影响了计算机科学和工程课程的几个不同领域。该项目还促进有关暑期研究的活动，目的是积极招募妇女和代表性不足的少数群体参加高等教育和研究。

Advances in optical devices and interconnects have made this technology attractive for telecommunication and high performance systems. Specifically, large optical switches are commercially available but no practical technology is yet available for buffering or processing in the optical domain. As a result, electronic packet switching and wormhole-routing remain popular in spite of their higher costs, limited bandwidth, and increased message latencies.In this project, the Investigators propose the use of circuit switching as an efficient alternative to packet and wormhole switching for achieving high bandwidth, low latency communication in high performance parallel systems. Specifically, by establishing direct pipes between communicating processes, routing and buffering at intermediate switches can be eliminated, end-to-end protocols can be simplified, and both software and hardware overheads associated with data movement can be minimized. However, the overhead of circuit establishment can be relatively large, and the benefits of circuit switching can only outweigh its drawbacks when communication exhibits locality, and when this locality is appropriately explored. Thus, a compiler-based approach is proposed to analyze communication locality in parallel application programs. This approach exposes the communication locality to an architecture, which explores it through a run-time system that manages circuit switched interconnections.The new compiler technology for the detection and manipulation of communication patterns developed as part of this research enables parallelism in several domains outside of high performance supercomputers including chip multiprocessor systems and wireless systems. By correlating code structure with communication patterns, the proposed compiler technology also allows for the construction of tools that assist application developers in writing more efficient programs. Moreover, this project impacts several different areas of curriculum in computer science and engineering through the integration of research from this project into computer engineering curriculum and design projects. The project also promotes summer research activities related aimed at active recruitment and participation of women and under-represented minorities in higher education and research.