On Jul 16, 2012, at 5:40 PM, Jed Brown wrote:
> On Mon, Jul 16, 2012 at 5:32 PM, Barry Smith <bsmith at mcs.anl.gov> wrote:
> Why shouldn't they be the same? Everything should still work fine. Where in
> PETSc do we make the assumption MPI_COMM_SELF is not MPI_COMM_WORLD and why?
> Except for Shi's new stuff and the new elemental stuff everything else in
> PETSc has worked fine with them being the same for 15 years. Hence the
> problem is likely with Shri's and Hong's interactions with MPI; not with the
> current MPIUNI.
>
> It is a hack to externally reference count based on PETSC_HAVE_MPIUNI or
> comparison for equality.
I totally agree it is a hack and should never be used, BUT as far as I was
aware in no place in PETSc did we do that? If that is it should be fixed. But
the fix is likely not forcing mpiuni to have two communicators it is just to do
things right.
Barry
