Compiling with C and OpenMPI

[jmoynihanVA]

Question

Hello. My company has recently used trilinos to speed up a routine for one of our plugins. we are trying to figure out how to package the plugin for our users. The Trilinos dependency, libmpi_cxx.so, is the C++ binding for OpenMPI, which is no longer supported by OpenMPI. Instead, OpenMPI supports C bindings. How should we proceed? Has Trilinos been updated to use C bindings? Or should we recompile OpenMPI with C++ bindings enabled (even though they are depreciated)? We would prefer not to require our users to use unsupported software.

Thanks,

Joseph Moynihan

[cgcgcg]

As far as I know we do not rely on the C++ bindings. Can you post how you are configuring Trilinos to end up with linking against libmpi_cxx.sp?

[jmoynihanVA]

I believe we are using an older version of trilinos (13.4.1) since we started first using it, so maybe something has changed since then, or we just messed up the configuration. Here is the contents of our configuration file.

cmake
-DTPL_ENABLE_MPI=ON
-DMPI_BASE_DIR=project/software/ubuntu-22.04/openmpi/4.1.0/gnu/11.3.0/bin
-DBUILD_SHARED_LIBS=ON
-DTPL_ENABLE_Netcdf=OFF
-DPYTHON_INCLUDE_DIR=$(python3 -c "import sysconfig; print(sysconfig.get_path('include'))")
-DPYTHON_LIBRARY=$(python3 -c "import sysconfig; print(sysconfig.get_config_var('LIBDIR'))")
-DTrilinos_ENABLE_ALL_PACKAGES=ON
-DTrilinos_ENABLE_PyTrilinos=OFF
-DCMAKE_INSTALL_PREFIX=/project/software/ubuntu-22.04/trilinos/13.4.1/openmpi/4.1.0/gnu/11.4.0 \
/project/software/ubuntu-22.04/trilinos/13.4.1/Trilinos-trilinos-release-13-4-1
make -j4 install

[cgcgcg]

Maybe the easiest way to figure this out: disable libmpi_cxx.so and see if things still build? If not, point me to what fails?

[jmoynihanVA]

How would I go about disabling that?

[cgcgcg]

I am assuming that you build your own MPI to get it in the first place? I doesn't seem to ship with MPI on my Debian system.