Thanks for looking at it! Apparently, someone requested support for heterogeneous machines long time ago: https://bugs.launchpad.net/ubuntu/+source/openmpi/+bug/419074
Xavier On Mon, Nov 13, 2017 at 7:56 PM, Gilles Gouaillardet < gilles.gouaillar...@gmail.com> wrote: > 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 >
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