Xavier, i confirm there is a bug when using MPI_ANY_SOURCE with Open MPI configure'd with --enable-heterogeneous
i made https://github.com/open-mpi/ompi/pull/4501 in order to fix that, and will merge and backport once reviewed Cheers, Gilles On Mon, Nov 13, 2017 at 8:46 AM, Gilles Gouaillardet <gilles.gouaillar...@gmail.com> wrote: > 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
