how the overlap sizes combined with the dmlibmesh

[Ricardotu]

I'm testing the impact of overlap size on my ASM preconditioner. I noticed in the libMesh source code that there's a dmlibmesh, which seems to be the default DM in libMesh. I would like to understand how mesh-based overlap is implemented in libMesh. Also, which part of the code combines the overlap with dmlibmesh? I mean if there is mesh-based overlaps

[roystgnr]

If you're testing -pc_asm_overlap, that's done at the PETSc level independently of libMesh ghosting levels and DM interfaces.

[Ricardotu]

Is this on the level of algebra? There is a code comment/* FIX: allow mesh-based overlap. */ in petscdmlibmeshimpl.C . It doesn't seem to be mesh-based.