[petsc-users] Correct use of PCFactorSetMatOrderingType

Zhang, Hong hzhang at mcs.anl.gov
Tue Nov 6 09:04:57 CST 2018


Edoardo:
You can test runtime option '-sub_pc_factor_mat_ordering_type' and use '-log_view' to get performance on different orderings, e.g.,petsc/src/ksp/ksp/examples/tutorials/ex2.c:
mpiexec -n 2 ./ex2 -ksp_view -sub_pc_type ilu -sub_pc_factor_mat_ordering_type nd

I do not think the ordering inside block for ilu would affect performance much. Let us know what you will get.
Hong

Dear users,

I have a question about the correct use of the option  "PCFactorSetMatOrderingType" in PETSc.

I am solving a problem with 2.5M of unknowns distributed along 16 processors and  I am using the block jacobi preconditioner and MPIAIJ matrix format. I cannot figure out if the above option can be useful or not in decreasing the computational time. Any suggestion or tips?

Thank you very much for the kind help

------

Edoardo Alinovi, Ph.D.

DICCA, Scuola Politecnica
Universita' di Genova
1, via Montallegro
16145 Genova, Italy

email: edoardo.alinovi at dicca.unige.it<mailto:edoardo.alinovi at dicca.unige.it>
Tel: +39 010 353 2540


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