Re: [Libmesh-devel] MPI Partitioner support clarification

[Roy S. <roy...@ic...>]

On Thu, 9 Nov 2017, Boris Boutkov wrote:

> Well, I eliminated PETSc and have been linking to MPI using
> --with-mpi=$MPI_DIR and playing with the refinement example I had
> mentioned earlier to try and eliminate ParMETIS due the the
> hang/crash issue. In these configs I attach either the
> LinearPartitioner or an SFC in prepare_for_use right before calling
> partition(). This causes assert trips in MeshComm::Redistribute
> where elem.proc_id != proc_id while unpacking elems (stack below).

Shoot - I don't think either of those partitioners have been upgraded
to be compatible with DistributedMesh use.  Just glancing at
LinearPartitioner, it looks like it'll do fine for an *initial*
partitioning, but then it'll scramble everything if it's ever asked to
do a *repartitioning* on an already-distributed mesh.

I could probably fix that pretty quickly, if you've got a test case I
can replicate.

SFC, on the other hand, I don't know about.  We do distributed
space-filling-curve stuff elsewhere in the library with libHilbert,
and it's not trivial.
---
Roy