[Mitgcm-support] Re: MPI with ifc broken ?

[mitgcm-support at dev.mitgcm.org]

Hi again,

> It seems that something is broken in the code
> for MPI with ifc (Linux, like the myrinet-3 cluster)
> between checkpoint48e (still working) and checkpoint48f:
> no output (all STDOUT + STDERR are empty) and the
> error message is (on 2 cpus):

Finally it turns to be weekly related to modifications
for scatter_2d.F gather_2d.F : the problem is in
ini_procs.F (eesup/src) and is due to the changes between 1.14 and 1.15:

> C--   To speed-up mpi gather and scatter routines, myXGlobalLo
> C     and myYGlobalLo from each process are transferred to
> C     a common block array.  This allows process 0 to know
> C     the location of the domains controlled by each process.
>        DO npe = 0, numberOfProcs-1
>           CALL MPI_SEND (myXGlobalLo, 1, MPI_INTEGER,
>      &         npe, mpiMyId, MPI_COMM_MODEL, ierr)
>        ENDDO
>        DO npe = 0, numberOfProcs-1
>           CALL MPI_RECV (itemp, 1, MPI_INTEGER,
>      &         npe, npe, MPI_COMM_MODEL, istatus, ierr)
>           mpi_myXGlobalLo(npe+1) = itemp
>        ENDDO
>        DO npe = 0, numberOfProcs-1
>           CALL MPI_SEND (myYGlobalLo, 1, MPI_INTEGER,
>      &         npe, mpiMyId, MPI_COMM_MODEL, ierr)
>        ENDDO
>        DO npe = 0, numberOfProcs-1
>           CALL MPI_RECV (itemp, 1, MPI_INTEGER,
>      &         npe, npe, MPI_COMM_MODEL, istatus, ierr)
>           mpi_myYGlobalLo(npe+1) = itemp
>        ENDDO   

When I comment those lines, it works fine.

Jean_Michel