could you provide me a simple testcode for that? Comm_join and
intercomm_merge should work, I would have a look at that...
(separate answer to your second email is coming soon)
Robert Latham wrote:
> I've got a bit of an odd bug here. I've been playing around with MPI
> process management routines and I notied the following behavior with
> Two processes (a and b), linked with ompi, but started independently
> (no mpiexec, just started the programs directly).
> - a and b: call MPI_Init
> - a: open a unix network socket on 'fd'
> - b: connect to a's socket
> - a and b: call MPI_Comm_join over 'fd'
> - a and b: call MPI_Intercomm_merge, get intracommunicator.
> These steps all work fine.
> Now the odd part: a and b call MPI_Comm_rank and MPI_Comm_size over
> the intracommunicator. Both (correctly) think Comm_size is two, but
> both also think (incorrectly) that they are rank 1.