CAREER: Operating System Support for Ephemeral and Malleable Accelerators

随着摩尔定律的衰落，计算机系统越来越依赖于专用硬件或加速器来提高性能、可扩展性和能效。到2025年，数据中心预计将消耗全球总电力的9%至20%，因此提高性能和效率对我们地球的健康至关重要。现场可编程门阵列（FPGA）是可重新配置的硬件，可以灵活地根据需要成为任何专用硬件。它们在现代数据中心中很有吸引力，因为它们可以从单个可重新配置的设备中合成各种加速器;亚马逊和微软等供应商现在支持云中的FPGA加速。然而，对于传统的操作系统来说，向可重构硬件的范式转变是巨大的，传统的操作系统被设计用于管理固定功能的设备。目前的系统假设一个单一的应用程序具有独占访问的硬件，缺乏共享支持限制了利用率和efficiency.The研究的目标是开发系统级的抽象和端到端的操作系统（OS）的保护FPGA共享，提高利用率和吞吐量的数量级或更多的支持。这是具有挑战性的，因为FPGA加速器是短暂的和可延展的：它们可能会经常变化，并且能够随着FPGA资源份额的增加而扩展。这些属性与几十年前的操作系统设计假设背道而驰。该项目旨在建立一个完整的开源堆栈，支持服务器进程的高效高利用率保护共享，以将计算卸载到FPGA，并将其扩展为云FPGA平台的兼容层。对名为AmorphOS的初始原型的测量表明，该方法具有前景，可以将运行神经网络（DNN）推理的Microsoft Catapult和Amazon F1系统的利用率和吞吐量提高8倍和32倍。该系统有可能广泛应用于支持FPGA的数据中心，其工作成果可以指导异构和可重构硬件的下一代操作系统的设计。该奖项反映了NSF的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。

With the decline of Moore's Law, computer systems increasingly rely on specialized hardware, or accelerators to improve performance, scalability and energy efficiency. Data centers are projected to consume between 9% and 20% of the world's total power by 2025, so improved performance and efficiency are important to the health of our planet. Field Programmable Gate Arrays, or FPGAs, are reconfigurable hardware with flexibility to become any specialized hardware on demand. They are compelling in modern data centers because they enable a wide range of accelerators to be synthesized from a single reconfigurable device; providers such as Amazon and Microsoft now support FPGA acceleration in the cloud. However, the paradigm shift to reconfigurable hardware is massive for traditional operating systems, which are designed to manage fixed-function devices. Current systems assume a single application has exclusive access to the hardware, and the lack of sharing support limits utilization and efficiency.The goal of this research is to develop system-level abstractions and end-to-end operating system (OS) support for protected FPGA sharing that improves utilization and throughput by an order of magnitude or more. This is challenging because FPGA accelerators are ephemeral and malleable: they may change frequently and be able to scale with increased shares of FPGA resource. These properties run counter to decades-old OS design assumptions. The project aims for a complete open-source stack that supports efficient high-utilization protected sharing for server processes to offload computations to FPGAs, and will extend it to function as a compatibility layer for cloud FPGA platforms. Measurements of an initial prototype called AmorphOS show that the approach has promise and can improve utilization and throughput by 8X and 32X for Microsoft Catapult and Amazon F1 systems running neural network (DNN) inference. The system has the possibility to be used pervasively in data centers supporting FPGAs, and the results of the work could guide the design of the next generation of operating systems for heterogeneous and reconfigurable hardware.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.