Open MPI logo

Open MPI Development Mailing List Archives

  |   Home   |   Support   |   FAQ   |   all Development mailing list

From: Edgar Gabriel (gabriel_at_[hidden])
Date: 2005-08-17 10:47:02


as far as I know nothing has changed in the communicator setup since
quite a while, the remote group is still set to the local group for
intra-communicators. However, ompi_comm_remote_size has a check whether
we have an inter-comm, and returns else zero (which is in theory the
correct answer)....


Jeff Squyres wrote:
> I thought that we set the remote group equal to the local group in
> communicator setup such that ompi_comm_remote_size() was *always* safe
> to call...?
> This no longer seems to be true -- while debugging the IMB (previously
> the pallas benchmarks), I found that calling
> ompi_comm_remote_size(comm) would return 0 and ompi_comm_size(comm)
> would return 2 for a simple intracommunicator. This was with:
> mpirun -np 2 IMB-MPI1 Reduce
> Has something changed in communicator setup?

Dr.-Ing. Edgar Gabriel
Clusters and Distributed Units
High Performance Computing Center Stuttgart (HLRS)
University of Stuttgart
Tel: +49 711 685 8039      
Fax: +49 711 678 7626                e-mail:gabriel_at_[hidden]