/* exchange data in rdb manner */
smpi_mpi_sendrecv(recv_buf, count, dtype, dst, tag, tmp_buf, count, dtype,
dst, tag, comm, &status);
/* exchange data in rdb manner */
smpi_mpi_sendrecv(recv_buf, count, dtype, dst, tag, tmp_buf, count, dtype,
dst, tag, comm, &status);