XPS: FULL: FP: Tools and Algorithms for Resilient, Power-efficient ExaScale Computing Using the GNU-CAF Compiler

XPS：FULL：FP：使用 GNU-CAF 编译器实现弹性、高能效 ExaScale 计算的工具和算法

基本信息

批准号：
1533850
负责人：
Dinshaw Balsara
金额：
$ 75.09万
依托单位：
University of Notre Dame
依托单位国家：
美国
项目类别：
Standard Grant
财政年份：
2015
资助国家：
美国
起止时间：
2015-10-01 至 2020-09-30
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=1533850&HistoricalAwards=false
关键词：
XPS FULL FP Tools Algorithms

项目摘要

Various problems of technological significance as well as of deep scientific interest require the use of parallel computers with the highest levels of parallelism. Thus, it is well-recognized in the scientific community that this research needs to be performed on Exascale computers, i.e. computers that have a thousand-fold greater computing power than computers today. But the technological endeavour of scaling-up comes with several attendant problems, such as being able to reuse existing code and giving the ability to ordinary developers to write scalable software that is also efficient with respect to power consumption, and is fault tolerant. This project addresses these needs by providing a open-source (GNU licensed), free, FORTRAN compiler that can make existing code Exascale ready, and which allows a programmer who only needs to be familiar with FORTRAN (and there are many of those) to develop scalable, power-efficient and fault-tolerant code, without having to learn an inordinate amount of new programming skills. The project will also contribute to a textbook on scientific computation that is being written by the Principal Investigator, as well as to a textbook on high performance computing that is being written by 2 other researchers on the team. The project website already exists that will freely distribute such knowledge to the public. This website already gets more than 50,000 hits per year. The proposal will make the following transformative advances:1) Develop a full-fledged, open-source, Exascale-Ready GNU compiler that implements novel parallel features of the Fortran 2008 standard. These Fortran features go under the name of Coarray Fortran (CAF). Recent work has shown that CAF is either competitive or outperforms the recent MPI-3 standard while allowing the end-user to express Petascale-class parallelism much more simply. Future architectures should make the one-sided CAF-style messaging much less power-hungry compared to alternative styles of messaging.2) Exascale computers will need to support billion-way concurrency among cores, with the result that nodes might fail quite frequently. Resiliency to failure will have to be built into the compiler technologies and end-user application. An early implementation of failure-resiliency within the GNU compiler will be made and it will be used to explore how those features work within a large class of Computational Fluid Dynamics (CFD) algorithms.3) Exascale applications will also have to use power very parsimoniously. This can only be done by deciding when to focus resources on communication and when to focus them on computation. New algorithms are needed that intersperse relatively modest amounts of communication with large amounts of computation. Furthermore, the expert-level algorithm developer should be able to communicate these different resource needs to the run-time system via compiler directives. The proposed work will develop a class of high-accuracy CFD algorithms that can communicate their resource needs to the run-time system via compiler extensions in the GNU compiler.

各种具有技术意义和深刻科学意义的问题都需要使用具有最高并行度的并行计算机。因此，科学界普遍认为这项研究需要在百亿亿次计算机上进行，即计算能力比当今计算机高出千倍的计算机。但扩展的技术努力伴随着几个随之而来的问题，例如能够重用现有代码，并让普通开发人员能够编写可扩展的软件，该软件在功耗方面也很高效，并且具有容错能力。该项目通过提供开源（GNU 许可）、免费的 FORTRAN 编译器来满足这些需求，该编译器可以使现有代码准备好，并且允许只需要熟悉 FORTRAN（并且有很多这样的）的程序员开发可扩展、节能和容错的代码，而无需学习大量的新编程技能。该项目还将为首席研究员编写的一本科学计算教科书以及该团队的其他两名研究人员编写的高性能计算教科书做出贡献。该项目网站已经存在，可以免费向公众传播这些知识。该网站每年的点击量已超过 50,000 次。该提案将带来以下变革性进展：1) 开发成熟的、开源的、Exascale-Ready GNU 编译器，实现 Fortran 2008 标准的新颖并行功能。这些 Fortran 功能以 Coarray Fortran (CAF) 的名称命名。最近的工作表明，CAF 具有竞争力或优于最新的 MPI-3 标准，同时允许最终用户更简单地表达 Petascale 级并行性。与其他消息传递方式相比，未来的架构应该使单侧 CAF 式消息传递的耗电量大大降低。2) 百亿亿级计算机将需要支持内核之间的数十亿路并发，结果是节点可能会频繁发生故障。编译器技术和最终用户应用程序必须内置容错能力。将在 GNU 编译器中早期实现故障恢复能力，并将用于探索这些功能如何在一大类计算流体动力学 (CFD) 算法中工作。3) 百亿亿级应用程序还必须非常节约地使用电源。这只能通过决定何时将资源集中在通信上以及何时将资源集中在计算上来完成。需要新的算法来将相对少量的通信与大量的计算相结合。此外，专家级算法开发人员应该能够通过编译器指令将这些不同的资源需求传达给运行时系统。拟议的工作将开发一类高精度 CFD 算法，这些算法可以通过 GNU 编译器中的编译器扩展将其资源需求传达给运行时系统。