/* Create the buffer */
MPI_Comm_size(comm, &size);
+ if(size<=0){
+ printf("error : comm size <= 0, run with mpirun\n");
+ return -1;
+ }
MPI_Comm_rank(comm, &rank);
int* sbuf = (int *) xbt_malloc(size * size * sizeof(int));
int* rbuf = (int *) xbt_malloc(size * size * sizeof(int));