Performance optimized software strategies for unstructured-mesh applications in ocean modeling

要对海洋、大气和气候应用进行准确的模拟，需要非常有效的数值格式和巨大的计算资源，这在世界许多地区和许多活跃在这一领域的组织是不容易获得的。这些限制还在以下事实中发挥重要作用：结构化网格模型仍然构成海洋科学领域社区代码的支柱。在这个项目中，我们建议显著提高非结构网格海洋应用程序的计算性能-专注于基于不连续Galerkin有限元方法的求解器-同时，减少实现新方法和应用程序的工作量。第一个目标将通过利用一些旨在解决现有性能瓶颈的技术来实现；这些技术包括一种新的区域分解方法和面向性能的自适应数值格式。第二个目标将通过采用现代软件设计战略来实现，包括针对计算密集型内核的代码生成和自动优化技术。本文提出的工作带来的性能和代码设计方面的进步可以涵盖许多方面，使非结构网格模型成为海洋科学的主流，特别是对有限访问高性能计算系统的用户可用。

Producing accurate simulations of ocean, atmosphere, and climate applications requires very efficient numerical schemes and huge computational resources not readily available in many parts of the world and to many groups active in this field. Such limitations also play a significant role in the fact that structured grid models still constitute the mainstay for community codes in the area of ocean science. In this project, we propose both to significantly improve the computational performance of unstructured grid ocean applications - focusing on a solver based on the discontinuous Galerkin finite element method - and, at the same time, to decrease the effort to implement new methods and applications. The first goal will be reached by utilizing a number of techniques aiming to address the existing performance bottlenecks; those include a new approach to domain decomposition and performance oriented adaptive numerical schemes. The second goal will be achieved by resorting to modern software design strategies, including code generation and automatic optimization techniques for the compute-intensive kernels. The performance and code design advances resulting from the work proposed here can cover a lot of ground towards making unstructured mesh models the mainstream of ocean science and, in particular, available to users with limited access to HPC systems.