Abstract: With the development of supercomputer and its programming environment, multilevel parallelism under heterogeneous system infrastructure is a promising trend.Applications ported to Sunway TaihuLight are typical.Since the Sunway TaihuLight was open to public in 2016, many scholars focus on the method study and application verification, so much experience on Shenwei many-core programming method is accumulated.However, when the CESM model is ported to Shenwei many-core infrastructure, some two dimensional computations in the ported POP model show quite good results under 1024 processes.On the contrary, they perform much worse than the original version, and false acceleration ratios appeared under 16800 processes.Upon this problem, a new parallel method based on slave-core partitions was proposed.Under the new parallel method, the 64 slave-cores in a core-group are divided into some disjoint small partitions, which make that different and independent computing kernels can run at different slave-core partitions simultaneously.In the method, the computing kernels can be loaded to different slave-core partitions with the suitable data size and computational load, where the amount and number of the slave-cores in each partition can be pro-perly set according to the computing scale, so the slave-core’s calculation ability can be fully utilized.Based on the new parallel method, also with the loops combination and function expansion, the slave-cores are fully applied and some computing time among several parallel running codes is hidden.Furthermore, it is effective to extend the parallel granularity of the kernels to be athrea-ded.Applied the above methods, the simulation speed of POP model in high-resolution CESM G-compset is improved by 0.8 si-mulation year per day under 1.1 million cores.

Key words: 2D-array computation, Large scalability, Parallel granularity, Shenwei many-core, Slave-core partition