Towards Exascale Parallel Delaunay Mesh Generation

Mesh generation is a critical component for many (bio-)engineering applications. However, parallel mesh generation codes, which are essential for these applications to take the fullest advantage of the high-end computing platforms, belong to the broader class of adaptive and irregular problems, and are among the most complex, challenging, and labor intensive to develop and maintain. As a result, parallel mesh generation is one of the last applications to be installed on new parallel architectures. In this paper we present a way to remedy this problem for new highly-scalable architectures. We present a multi-layered tetrahedral/triangular mesh generation approach capable of delivering and sustaining close to 1018 of concurrent work units. We achieve this by leveraging concurrency at different granularity levels using a hybrid algorithm, and by carefully matching these levels to the hierarchy of the hardware architecture. This paper makes two contributions: (1) a new evolutionary path for developing multi-layered parallel mesh generation codes capable of increasing the concurrency of the state-of-the-art parallel mesh generation methods by at least 10 orders of magnitude and (2) a new abstraction for multi-layered runtime systems that target parallel mesh generation codes, to efficiently orchestrate intra- and inter-layer data movement and load balancing for current and emerging multi-layered architectures with deep memory and network hierarchies.