Gilles,
I'm using NetPIPE which is available at http://netpipe.cs.ksu.edu
My base test is uni-directional with 1 process on a node communicating
with a process on a second node.
make mpi
mpirun -np 2 --hostfile=hf.2p2n NPmpi
cat hf.2p2n
node0 slots=1
node1 slots=1
NetPIPE does not do any MPI_Init_thread().
Tests on the configs below give good performance with and without the
--enable-mpi-thread-multiple
so I don't think that's the issue.
configure --prefix=/homes/daveturner/libs/openmpi-2.1.1
--enable-mpi-fortran=all --with-verbs --enable-ipv6 --enable-mpi-cxx
configure --prefix=/homes/daveturner/libs/openmpi-2.1.1
--enable-mpi-fortran=all --with-verbs --enable-ipv6 --enable-mpi-cxx
--enable-mpi-thread-multiple
Dave
On Tue, Jan 23, 2018 at 10:03 PM, Gilles Gouaillardet <
[email protected]> wrote:
> Dave,
>
> At first glance, that looks pretty odd, and I'll have a look at it.
>
> Which benchmark are you using to measure the bandwidth ?
> Does your benchmark MPI_Init_thread(MPI_THREAD_MULTIPLE) ?
> Have you tried without --enable-mpi-thread-multiple ?
>
> Cheers,
>
> Gilles
>
> On Wed, Jan 24, 2018 at 12:55 PM, Dave Turner <[email protected]>
> wrote:
> >
> > We compiled OpenMPI 2.1.1 using the EasyBuild configuration
> > for CentOS as below and tested on Mellanox QDR hardware.
> >
> > ./configure --prefix=/homes/daveturner/libs/openmpi-2.1.1c
> > --enable-shared
> > --enable-mpi-thread-multiple
> > --with-verbs
> > --enable-mpirun-prefix-by-default
> > --with-mpi-cxx
> > --enable-mpi-cxx
> > --with-hwloc=$EBROOTHWLOC
> > --disable-dlopen
> >
> > The red curve in the attached NetPIPE graph shows the poor performance
> above
> > 8 kB for the uni-directional tests with bi-directional and aggregate
> > tests also showing similar problems. When I compile using the same
> > configuration but with the --disable-dlopen parameter removed then the
> > performance is very good as the green curve in the graph shows.
> >
> > We see the same problems with OpenMPI 2.0.2.
> > Replacing --disable-dlopen with --disable-mca-dso showed good
> performance.
> > Replacing --disable-dlopen with --enable-static showed good performance.
> > So it's only --disable-dlopen that leads to poor performance.
> >
> > http://netpipe.cs.ksu.edu
> >
> > Dave Turner
> >
> > --
> > Work: [email protected] (785) 532-7791
> > 2219 Engineering Hall, Manhattan KS 66506
> > Home: [email protected]
> > cell: (785) 770-5929
> >
> > _______________________________________________
> > devel mailing list
> > [email protected]
> > https://lists.open-mpi.org/mailman/listinfo/devel
>
--
Work: [email protected] (785) 532-7791
2219 Engineering Hall, Manhattan KS 66506
Home: [email protected]
cell: (785) 770-5929
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