Ok. MPICH/OpenMPI could be used for sequential runs and parallel within node. [and not between nodes?] Satish On Fri, 16 Apr 2021, Mark Adams wrote:

On Fri, Apr 16, 2021 at 11:33 AM Satish Balay <[email protected]> wrote:

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Mark, Why a no-mpi build on Fugaku?

Kokkos Kernels + OMP barfed and Kokkos suggested gcc. There does not seem to be an MPI for GCC here.

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Toby - there is one more issue with p4est - build error when using --with-batch=1

Attaching configure.log

Satish

On Fri, 16 Apr 2021, Isaac, Tobin G wrote:

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p4est has a mode where it can compile without MPI, I don't know if PETSc is using it, will check.

________________________________________ From: petsc-dev <[email protected]> on behalf of Mark Adams <[email protected]> Sent: Friday, April 16, 2021 10:23 To: For users of the development version of PETSc Subject: [petsc-dev] p4est w/o MPI

I don't have MPI (Fugaku w/ gcc) and p4est seems to need it. Is there a work around? Thanks, Mark