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Subject: Re: [OMPI users] Problems with GATHERV on one process
From: Tim Mattox (timattox_at_[hidden])
Date: 2007-12-11 17:33:38


Hello Ken,
This is a known bug, which is fixed in the upcoming 1.2.5 release. We
expect 1.2.5
to come out very soon. We should have a new release candidate for 1.2.5 posted
by tomorrow.

See these tickets about the bug if you care to look:
https://svn.open-mpi.org/trac/ompi/ticket/1166
https://svn.open-mpi.org/trac/ompi/ticket/1157

On Dec 11, 2007 2:48 PM, Moreland, Kenneth <kmorel_at_[hidden]> wrote:
> I recently ran into a problem with GATHERV while running some randomized
> tests on my MPI code. The problem seems to occur when running
> MPI_Gatherv with a displacement on a communicator with a single process.
> The code listed below exercises this errant behavior. I have tried it
> on OpenMPI 1.1.2 and 1.2.4.
>
> Granted, this is not a situation that one would normally run into in a
> real application, but I just wanted to check to make sure I was not
> doing anything wrong.
>
> -Ken
>
>
>
> #include <mpi.h>
>
> #include <stdlib.h>
> #include <stdio.h>
>
> int main(int argc, char **argv)
> {
> int rank;
> MPI_Comm smallComm;
> int senddata[4], recvdata[4], length, offset;
>
> MPI_Init(&argc, &argv);
>
> MPI_Comm_rank(MPI_COMM_WORLD, &rank);
>
> // Split up into communicators of size 1.
> MPI_Comm_split(MPI_COMM_WORLD, rank, 0, &smallComm);
>
> // Now try to do a gatherv.
> senddata[0] = 5; senddata[1] = 6; senddata[2] = 7; senddata[3] = 8;
> recvdata[0] = 0; recvdata[1] = 0; recvdata[2] = 0; recvdata[3] = 0;
> length = 3;
> offset = 1;
> MPI_Gatherv(senddata, length, MPI_INT,
> recvdata, &length, &offset, MPI_INT, 0, smallComm);
> if (senddata[0] != recvdata[offset])
> {
> printf("%d: %d != %d?\n", rank, senddata[0], recvdata[offset]);
> }
> else
> {
> printf("%d: Everything OK.\n", rank);
> }
>
> return 0;
> }
>
> **** Kenneth Moreland
> *** Sandia National Laboratories
> ***********
> *** *** *** email: kmorel_at_[hidden]
> ** *** ** phone: (505) 844-8919
> *** fax: (505) 845-0833
>
>
>
> _______________________________________________
> users mailing list
> users_at_[hidden]
> http://www.open-mpi.org/mailman/listinfo.cgi/users
>

-- 
Tim Mattox, Ph.D. - http://homepage.mac.com/tmattox/
 tmattox_at_[hidden] || timattox_at_[hidden]
    I'm a bright... http://www.the-brights.net/