Hi, I am using mumps in PETSc to solve a 0.2 million system on 128 cores. Within Newton-Raphson iteration, the system with same sparse structure but different values will be solved many times. And I specify the preconditioning matrix having same nonzero pattern. The first time solving costs around 900 seconds and later solving only takes around 200 seconds. So I am wondering why the time differs that much. By setting the same nonzero pattern of pc, which of the mumps control parameters does PETSc change? Thanks.
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