Open MPI logo

Open MPI User's Mailing List Archives

  |   Home   |   Support   |   FAQ   |   all Open MPI User's mailing list

From: Robert Latham (robl_at_[hidden])
Date: 2006-03-14 12:05:51


Hi

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
openmpi-1.0.1:

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.

==rob

-- 
Rob Latham
Mathematics and Computer Science Division    A215 0178 EA2D B059 8CDF
Argonne National Labs, IL USA                B29D F333 664A 4280 315B