XPS: EXPL: CCA: Merging Parallel Run-times and Operating Systems

标题：XPS：EXPL：CCA：合并并行运行时和操作系统并行性是将较大任务分解为可以同时完成的较小任务的能力，对于应用程序随着时间的推移继续以指数级速度增长至关重要。关于如何在硬件、编程语言、编译器和算法中实现并行性的研究已经投入了大量的精力，并且正在投入其中。然而，应用软件也依赖于系统软件，特别是操作系统内核。目前，应用软件和操作系统内核是两个截然不同的领域，两者之间的壁垒很高，只有操作系统内核才能完全访问硬件。虽然这种设计的存在有很好的理由，但它现在可能会限制并行性，从而限制应用程序中可能的性能。该项目研究了一种替代设计，其中应用软件和操作系统内核合并为一个实体。智力上的优点有很多。首先，这样的设计以前没有在并行性的背景下进行过研究——这个项目将确定它是否是一个好主意。其次，该设计与专为并行性而设计的现代语言和运行时系统产生共鸣——此类系统可以利用机会以新的方式使用操作系统内核和硬件。最后，鉴于项目团队之前在操作系统和高性能计算虚拟化方面的工作，他们已经做好了开展调查的准备。该项目更广泛的意义和重要性取决于替代设计可以提高性能的程度以及可利用的并行性的数量。如果这一点相当可观，那么替代设计可能会被广泛采用，从而有助于保持计算性能（甚至最终用户所体验到的）处于指数轨道上。该项目主要关注的是允许现代并行运行时系统（及其应用程序）本身被重新概念化为内核。通过成为内核，运行时可以访问机器的全部硬件功能，并且可以准确地实现实现其目标所需的内核抽象。该团队正在设计、实现和评估一个内核框架，以支持该模型的并行运行时系统的移植和构建。使用一组当前的几个运行时系统和几种不同类型的并行硬件，该团队还在研究哪些内核抽象在此模型中有用，以及如何利用仅限内核的硬件功能来更好地支持运行时系统。正在考虑将移植到模型的成熟运行时和可与模型共同设计的新生运行时。 该项目还与另一项工作相结合，该工作正在研究一种虚拟化方法，该方法可能使同时支持新模型和旧模型成为可能。

Title: XPS: EXPL: CCA: Merging Parallel Run-times and Operating SystemsParallelism, the ability to do break down larger tasks into smaller tasks that can be done simultaneously, is essential for applications to continue to become exponentially faster over time. Considerable effort has been placed and is being placed into research on how to achieve parallelism within hardware, programming languages, compilers, and algorithms. However, application software also depends on systems software, particularly the operating system kernel. Currently, the application software and the operating system kernel are very distinct domains with a high barrier between them, and only the operating system kernel has full access to the hardware. While this design exists for very good reasons, it may now limit the parallelism and thus the performance possible in applications. This project investigates an alternative design in which the application software and the operating system kernel are merged into one entity. The intellectual merits are several. First, such a design has not been previously studied in the context of parallelism---this project will determine if it is a good idea. Second, the design resonates with modern languages and run-time systems that are designed specifically with parallelism in mind---such systems can leverage the opportunity to use the operating system kernel and the hardware in new ways. Finally, the project team is well poised to carry out the investigation given their prior work in operating systems and virtualization for high performance computing. The project's broader significance and importance are based on the extent to which the alternative design can enhance performance and the amount of exploitable parallelism. If this is considerable, then the alternative design may be widely adopted and thus contribute to keeping computing performance, as experienced even by end-users, on its exponential track.The project is primarily concerned with allowing modern parallel run-time systems (and their applications) to be re-conceptualized as kernels in their own right. By being a kernel, a run-time can access the full hardware capabilities of the machine, and it can implement exactly the kernel abstractions that it needs to achieve its goals. The team is designing, implementing, and evaluating a kernel framework to support the porting and construction of parallel run-time systems for this model. Using a set of several current run-time systems and several different kinds of parallel hardware, the team is also investigating what kernel abstractions are useful within this model, as well as how to leverage kernel-only hardware features to better support the run-time systems. Both mature run-times which are to be ported to the model and nascent run-times that can be co-designed with the model are under consideration. The project also integrates with another effort that is investigating a virtualization approach that may make it possible to support the new model simultaneously with the old model.