As of two days ago, this problem has disappeared and the tests that I had written and run each night are now passing. Having looked through the update log of my machine (Ubuntu 11.10) it appears as though I got a new version of mpi-default-dev (0.6ubuntu1). I would like to understand this problem in more detail -- is it possible to see what changed in this update? Thanks, Brett.
> > On Fri, Dec 9, 2011 at 6:43 PM, teng ma <t...@eecs.utk.edu> wrote: > >> I guess your output is from different ranks. YOu can add rank infor >> inside print to tell like follows: >> >> (void) printf("rank %d: gathered[%d].node = %d\n", rank, i, >> gathered[i].node); >> >> From my side, I did not see anything wrong from your code in Open MPI >> 1.4.3. after I add rank, the output is >> rank 5: gathered[0].node = 0 >> rank 5: gathered[1].node = 1 >> rank 5: gathered[2].node = 2 >> rank 5: gathered[3].node = 3 >> rank 5: gathered[4].node = 4 >> rank 5: gathered[5].node = 5 >> rank 3: gathered[0].node = 0 >> rank 3: gathered[1].node = 1 >> rank 3: gathered[2].node = 2 >> rank 3: gathered[3].node = 3 >> rank 3: gathered[4].node = 4 >> rank 3: gathered[5].node = 5 >> rank 1: gathered[0].node = 0 >> rank 1: gathered[1].node = 1 >> rank 1: gathered[2].node = 2 >> rank 1: gathered[3].node = 3 >> rank 1: gathered[4].node = 4 >> rank 1: gathered[5].node = 5 >> rank 0: gathered[0].node = 0 >> rank 0: gathered[1].node = 1 >> rank 0: gathered[2].node = 2 >> rank 0: gathered[3].node = 3 >> rank 0: gathered[4].node = 4 >> rank 0: gathered[5].node = 5 >> rank 4: gathered[0].node = 0 >> rank 4: gathered[1].node = 1 >> rank 4: gathered[2].node = 2 >> rank 4: gathered[3].node = 3 >> rank 4: gathered[4].node = 4 >> rank 4: gathered[5].node = 5 >> rank 2: gathered[0].node = 0 >> rank 2: gathered[1].node = 1 >> rank 2: gathered[2].node = 2 >> rank 2: gathered[3].node = 3 >> rank 2: gathered[4].node = 4 >> rank 2: gathered[5].node = 5 >> >> Is that what you expected? >> >> On Fri, Dec 9, 2011 at 12:03 PM, Brett Tully <brett.tu...@oxyntix.com>wrote: >> >>> Dear all, >>> >>> I have not used OpenMPI much before, but am maintaining a large legacy >>> application. We noticed a bug to do with a call to MPI_Allgather as >>> summarised in this post to Stackoverflow: >>> http://stackoverflow.com/questions/8445398/mpi-allgather-produces-inconsistent-results >>> >>> In the process of looking further into the problem, I noticed that the >>> following function results in strange behaviour. >>> >>> void test_all_gather() { >>> >>> struct _TEST_ALL_GATHER { >>> int node; >>> }; >>> >>> int ierr, size, rank; >>> ierr = MPI_Comm_size(MPI_COMM_WORLD, &size); >>> ierr = MPI_Comm_rank(MPI_COMM_WORLD, &rank); >>> >>> struct _TEST_ALL_GATHER local; >>> struct _TEST_ALL_GATHER *gathered; >>> >>> gathered = (struct _TEST_ALL_GATHER*) malloc(size * >>> sizeof(*gathered)); >>> >>> local.node = rank; >>> >>> MPI_Allgather(&local, sizeof(struct _TEST_ALL_GATHER), MPI_BYTE, >>> gathered, sizeof(struct _TEST_ALL_GATHER), MPI_BYTE, >>> MPI_COMM_WORLD); >>> >>> int i; >>> for (i = 0; i < numnodes; ++i) { >>> (void) printf("gathered[%d].node = %d\n", i, gathered[i].node); >>> } >>> >>> FREE(gathered); >>> } >>> >>> At one point, this function printed the following: >>> gathered[0].node = 2 >>> gathered[1].node = 3 >>> gathered[2].node = 2 >>> gathered[3].node = 3 >>> gathered[4].node = 4 >>> gathered[5].node = 5 >>> >>> Can anyone suggest a place to start looking into why this might be >>> happening? There is a section of the code that calls MPI_Comm_split, but I >>> am not sure if that is related... >>> >>> Running on Ubuntu 11.10 and a summary of ompi_info: >>> Package: Open MPI buildd@allspice Distribution >>> Open MPI: 1.4.3 >>> Open MPI SVN revision: r23834 >>> Open MPI release date: Oct 05, 2010 >>> Open RTE: 1.4.3 >>> Open RTE SVN revision: r23834 >>> Open RTE release date: Oct 05, 2010 >>> OPAL: 1.4.3 >>> OPAL SVN revision: r23834 >>> OPAL release date: Oct 05, 2010 >>> Ident string: 1.4.3 >>> Prefix: /usr >>> Configured architecture: x86_64-pc-linux-gnu >>> Configure host: allspice >>> Configured by: buildd >>> >>> Thanks! >>> Brett >>> >>> _______________________________________________ >>> users mailing list >>> us...@open-mpi.org >>> http://www.open-mpi.org/mailman/listinfo.cgi/users >>> >> >> >> >> -- >> | Teng Ma Univ. of Tennessee | >> | t...@cs.utk.edu Knoxville, TN | >> | http://web.eecs.utk.edu/~tma/ | >> >> _______________________________________________ >> users mailing list >> us...@open-mpi.org >> http://www.open-mpi.org/mailman/listinfo.cgi/users >> > >