CNS Core: Small: Gmem: Unified Address Space Management for Heterogeneous Systems

随着新的通用处理器实现的性能逐年增长的下降，越来越多的各种设备，例如现场可编程门阵列，正在被添加到计算机中以加速应用。因此，操作系统（OS）不仅必须管理运行在通用处理器上的应用程序对计算机内存的访问，还必须管理运行在各种各样的加速器上的应用程序对计算机内存的访问。目前，这些加速器的内存访问是由不同的、不相连的操作系统部分管理的，这导致了独立的、冗余的、通常效率低下的实现的激增。这个项目旨在用一个统一的框架来取代目前的碎片化架构。具体来说，这个项目的主要目标是创建一个通用的映射和保护系统，称为Gmem，它将在操作系统中提供一个单一的、一致的接口，用于创建、管理和销毁映射到所有设备上的任何物理内存。Gmem将简化操作系统内映射系统的整体架构。它将使设备驱动程序的作者能够实现他们需要的特定于设备的行为，而不是实现一个完整的映射系统。此外，Gmem将提供异步接口并采用耦合页表管理，这两者将共同实现高性能和强大的保护。在不断追求提高性能的过程中，计算社区应该期望看到专用加速器的持续增长，与图形处理单元、网络接口和存储设备的集成增加，以及整个计算系统中大量的非易失性存储器。这种下一代计算系统中组件的聚合要求操作系统设计者重新思考操作系统管理不同内存的方式。这个项目的一个更广泛的影响是，它将有助于操作系统软件的重大创新，这将需要实现这些系统的全部潜力。为本项目创建的具有长期价值的软件工件和实验数据至少在项目结束后的三年内可以在https://github.com/rice-systems/gmem上获得。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识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 in year-over-year performance increases achieved by new general-purpose processors, a growing variety of devices, e.g., field-programmable gate arrays, are being added to computers to accelerate applications. Consequently, the operating system (OS) must not only manage access to the computer's memory by applications running on general-purpose processors but also on a diverse array of accelerators. Currently, memory access by these accelerators is managed by different, disconnected parts of the OS, leading to a proliferation of independent, redundant, and often inefficient implementations. This project aims to replace the current fragmented architecture by a unified framework for all devices.Specifically, this project's principal objective is to create a generalized mapping and protection system, called Gmem, that will provide a single, consistent interface within the OS for the creation, management, and destruction of mappings to any physical memory across all devices. Gmem will simplify the overall architecture of the mapping system within the OS. It will enable the authors of device drivers to implement just the device-specific behavior that they need, rather than implementing a complete mapping system. Furthermore, Gmem will provide asynchronous interfaces and employ coupled page table management, which together will enable high performance and strong protection.In its never-ending quest for increased performance, the computing community should expect to see the continued rise of specialized accelerators, increased integration with graphics processing units, networking interfaces, and storage devices, and large amounts of non-volatile memory across the computing system. This conglomeration of components in next generation computing systems requires OS designers to rethink the ways in which the OS manages disparate memory. A broader impact of this project is that it will contribute to the significant innovations in OS software that will be needed to realize the full potential of these systems.Software artifacts and experimental data of long-term value that are created for this project will be available at https://github.com/rice-systems/gmem for at least three years beyond the project's end.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.