Sorry there was a mistake in that code,
stypes and rtypes should be of type MPI_Datatype not integer
however the result is the same.
*** An error occurred in MPI_Alltoallw
*** reported by process [204406785,1]
*** on communicator MPI_COMM_WORLD
*** MPI_ERR_TYPE: invalid datatype
On Tue, Jan 12, 2016 at 7:55 PM, Jim Edwards <jedwa...@ucar.edu> wrote:
> Maybe the example is too simple. Here is another one which
> when run on two tasks sends two integers from each task to
> task 0. Task 1 receives nothing. This works with mpich and impi
> but fails with openmpi.
>
> #include <stdio.h>
> #include <mpi.h>
>
> my_mpi_test(int rank, int ntasks)
> {
> MPI_Datatype stype, rtype;
> int sbuf[2];
> int rbuf[4];
>
> int slen[ntasks], sdisp[ntasks], stypes[ntasks], rlen[ntasks],
> rdisp[ntasks], rtypes[ntasks];
> sbuf[0]=rank;
> sbuf[1]=ntasks+rank;
> slen[0]=2;
> slen[1]=0;
> stypes[0]=MPI_INT;
> stypes[1]=MPI_DATATYPE_NULL;
> sdisp[0]=0;
> sdisp[1]=4;
> if(rank==0){
> rlen[0]=2;
> rlen[1]=2;
> rtypes[0]=MPI_INT;
> rtypes[1]=MPI_INT;
> rdisp[0]=0;
> rdisp[1]=8;
>
> }else{
> rlen[0]=0;
> rlen[1]=0;
> rtypes[0]=MPI_DATATYPE_NULL;
> rtypes[1]=MPI_DATATYPE_NULL;
> rdisp[0]=0;
> rdisp[1]=0;
> }
>
> MPI_Alltoallw(sbuf, slen, sdisp, stypes, rbuf, rlen, rdisp, rtypes,
> MPI_COMM_WORLD);
> if(rank==0){
> printf("%d %d %d %d\n",rbuf[0],rbuf[1],rbuf[2],rbuf[3]);
> }
>
> int main(int argc, char **argv)
> {
> int rank, ntasks;
>
> MPI_Init(&argc, &argv);
>
> MPI_Comm_rank(MPI_COMM_WORLD,&rank);
> MPI_Comm_size(MPI_COMM_WORLD, &ntasks);
>
> printf("rank %d ntasks %d\n",rank, ntasks);
>
> my_mpi_test(rank,ntasks);
>
>
> MPI_Finalize();
> }
>
>
>
>
--
Jim Edwards
CESM Software Engineer
National Center for Atmospheric Research
Boulder, CO
