[petsc-users] How to use DMPlex_Distribute(_Overlap) without redistribution of the mesh

[Fabian.Jakub]

Dear Petsc team,
dear Matt,

I have a 3D, distributed DMPlex with 0 overlap in FVM adjacency.
Now, I would like to add overlap but not change the local portions.
I was wondering if you could suggest how to do that best/easiest.

My problem is that just using DMPlexDistribute changes the partitioning,
i.e. cells change owners.

I guess I could trace the steps you took in
DMPlexDistributeOverlap
and the following stuff you have in
DMPlexDistribute() { if overlap > 0 }

Another thought was to use a custom partitioner so as not to change the
local layouts. Is this a good idea?

In case that you suggest to go for first steps (the duplication of the
DMPlexDistributeOverlap stuff) could you add a fortran stub for it?

Many thanks,

Fabian