Xavier, thanks for the report, i will have a look at it.
is the bug triggered by MPI_ANY_SOURCE ? /* e.g. does it work if you MPI_Irecv(..., myrank, ...) ? */ Unless ubuntu wants out of the box support between heterogeneous nodes (for example x86_64 and ppc64), there is little to no point in configuring Open MPI with the --enable-heterogeneous option */ Cheers, Gilles On Mon, Nov 13, 2017 at 7:56 AM, Xavier Besseron <xavier.besse...@uni.lu> wrote: > Dear all, > > I want to share with you the follow issue with the OpenMPI shipped with the > latest Ubuntu Artful. It is OpenMPI 2.1.1 compiled with option > --enable-heterogeneous. > > Looking at this issue https://github.com/open-mpi/ompi/issues/171, it > appears that this option is broken and should not be used. > This option is being used in Debian/Ubuntu since 2010 > (http://changelogs.ubuntu.com/changelogs/pool/universe/o/openmpi/openmpi_2.1.1-6/changelog) > and is still used so far. Apparently, nobody complained so far. > > However, now I complain :-) > I've found a simple example for which this option causes invalid results in > OpenMPI. > > > int A = 666, B = 42; > MPI_Irecv(&A, 1, MPI_INT, MPI_ANY_SOURCE, tag, comm, &req); > MPI_Send(&B, 1, MPI_INT, my_rank, tag, comm); > MPI_Wait(&req, &status); > > # After that, when compiled with --enable-heterogeneous, we have A != B > > This happens with just a single process. The full example is in attachment > (to be run with "mpirun -n 1 ./bug_openmpi_artful"). > I extracted and simplified the code from the Zoltan library with which I > initially noticed the issue. > > I find it annoying that Ubuntu distributes a broken OpenMPI. > I've also tested OpenMPI 2.1.1, 2.1.2 and 3.0.0 and using > --enable-heterogeneous causes the bug systematically. > > > Finally, my points/questions are: > > - To share with you this small example in case you want to debug it > > - What is the status of issue https://github.com/open-mpi/ompi/issues/171 ? > Is this option still considered broken? > If yes, I encourage you to remove it or mark as deprecated to avoid this > kind of mistake in the future. > > - To get the feedback of OpenMPI developers on the use of this option, which > might convince the Debian/Ubuntu maintainer to remove this flag. > I have opened a bug on Ubuntu for it > https://bugs.launchpad.net/ubuntu/+source/openmpi/+bug/1731938 > > > Thanks! > > Xavier > > > -- > Dr Xavier BESSERON > Research associate > FSTC, University of Luxembourg > Campus Belval, Office MNO E04 0415-040 > Phone: +352 46 66 44 5418 > http://luxdem.uni.lu/ > > > _______________________________________________ > users mailing list > users@lists.open-mpi.org > https://lists.open-mpi.org/mailman/listinfo/users _______________________________________________ users mailing list users@lists.open-mpi.org https://lists.open-mpi.org/mailman/listinfo/users
