Thank you for the correction, really appreciate it.
regards
satya
--- Dries Kimpe <Dries.Kimpe_at_[hidden]> wrote:
> shiva v wrote:
> > Hello folks,
> >
> >
> > int main (int argc, char *argv[])
> > {
> >
> > int nprocs, myrank, i=0, data = 0;
>
> The type of data is int,
> sizeof (data) will probably return 4 (4 bytes)
>
> > MPI_Status status;
> >
> > MPI_Init(&argc, &argv);
> > MPI_Comm_size(MPI_COMM_WORLD, &nprocs);
> > MPI_Comm_rank(MPI_COMM_WORLD, &myrank);
> >
> > if(myrank == 0) {
> > printf("\n main thread no of procs %d \n",
> > nprocs);
> > for(i = 1; i < nprocs; i++) {
> > MPI_Recv ( &data, sizeof(data), MPI_INT, i,
> 1,
> >
> Here you say you want to receive 4 INTEGERS (=16
> bytes)
> overwriting whatever follows 'data' in memory.
> (most likely the
> MPI_Status variable)
>
> > MPI_COMM_WORLD, &status);
> > printf("\n %d thread %d \n", data, i );
> > }
> > } else {
> > data = 2 * myrank;
> > printf ("\n In thread %d , the value of data
> is %d
> > \n", myrank, data );
> >
> > MPI_Send (&data, sizeof(data), MPI_INT, 0, 1,
>
> Same here: you send 16 bytes worth of data, where
> data is only 4 bytes.
>
> Conclusion: the count argument in the send and
> receive routines
> specifies the number of basic blocks you send, not
> the number of bytes.
>
> Greetings,
> Dries
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>
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