A multi-GPU enabled solver in Kronecker product form for multiphysics problems
摘要
Modern engineering and scientific computing often requires solving sparse linear systems containing point-block matrix to model multiphysics problems. The space-time parallel method is popular and attractive in fluid dynamics, fitting parallel computers very well. In this paper, we design and implement a parallel, multi-GPU enabled GMRES solver for solving linear systems in the Kronecker product form arising from the domain decomposition based space-time parallel methods. To improve the efficiency of the solver, we also design a set of optimization strategies for Sparse Matrix-Vector Multiplication (SpMV) in Kronecker product form. These include: (1) enhancing the Compute-to-Memory Access Ratio (CMAR) to fully utilize the high bandwidth nature of the GPU during the computation phase and (2) introducing a parallel buffering scheme and a pre-mapping algorithm to enable the use of GPU-Direct for accelerating the communication phase. We conducted experiments on 1, 2, 4, and 8 GPUs and compared the performance of OKP-Solver with the cuSPARSE based implementation. On the V100 platform, the Kronecker product based SpMV computation (