What about PetscCommGetPkgComm(MPI_Comm comm ,const char* package, MPI_Comm* pkgcomm)
with a key for each of the external packages PETSc can use? > On Apr 3, 2018, at 10:56 PM, Kong, Fande <[email protected]> wrote: > > I think we could add an inner comm for external package. If the same comm is > passed in again, we just retrieve the same communicator, instead of > MPI_Comm_dup(), for that external package (at least HYPRE team claimed this > will be fine). I did not see any issue with this idea so far. > > I might be missing something here > > > Fande, > > On Tue, Apr 3, 2018 at 1:45 PM, Satish Balay <[email protected] > <mailto:[email protected]>> wrote: > On Tue, 3 Apr 2018, Smith, Barry F. wrote: > > > > > > > > On Apr 3, 2018, at 11:59 AM, Balay, Satish <[email protected] > > > <mailto:[email protected]>> wrote: > > > > > > On Tue, 3 Apr 2018, Smith, Barry F. wrote: > > > > > >> Note that PETSc does one MPI_Comm_dup() for each hypre matrix. > > >> Internally hypre does at least one MPI_Comm_create() per hypre boomerAMG > > >> solver. So even if PETSc does not do the MPI_Comm_dup() you will still > > >> be limited due to hypre's MPI_Comm_create. > > >> > > >> I will compose an email to hypre cc:ing everyone to get information > > >> from them. > > > > > > Actually I don't see any calls to MPI_Comm_dup() in hypre sources [there > > > are stubs for it for non-mpi build] > > > > > > There was that call to MPI_Comm_create() in the stack trace [via > > > hypre_BoomerAMGSetup] > > > > This is what I said. The MPI_Comm_create() is called for each solver and > > hence uses a slot for each solver. > > Ops sorry - misread the text.. > > Satish >
