Interpolation oriented parallel communication to optimize coupling in earth system modeling

摘要

Complicated global climate problems trigger researchers from different scientific disciplines to link multi-physics simulations called models for integrated modeling of climate changes by using a software framework called earth system modeling (ESM). As its critical component, coupler is in charge of connections and interactions among models. With the advance of next-generation models, greater data transfer volume and higher coupling frequency are expected to put heavy performance burden on coupler. High efficient coupling techniques are required. In this paper, we propose the sub-domain mapping method to improve the parallel coupling consisted of data transfer and data transformation. By using one specific interpolation oriented communication routing, the communication operations that are originally decentralized in various steps can be combined together for execution. This can reduce the redundant communications and the entailed synchronization costs. The tests on the Tianhe-1A (TH-1A) supercomputer show that our method can achieve 1.1 to 4.9 fold performance improvements. We also present further optimization solution for the multi-interpolation cases. The test results show that our method can achieve up to 3.4 fold speedup over the original coupling execution of the current climate system.