[OMPI users] binding to core odd results

Hi, In the process of testing out reframe I ran IMB pingpong using openmpi 3.1.0 with: mpirun -np 2 --report-bindings IMB-MPI1 pingpong I find that if set OMPI_MCA_hwloc_base_binding_policy=core I get slightly higher zero-size latency (1.58us vs 1.

[OMPI users] include/mpi.h:201:32: error: two or more data types in declaration specifiers

I'm trying to compile WRF against openmpi4 installed using Spack, using gcc 7. It's hitting lots of errors of which the first appears to be in the mpi header: ranlib ../libio_grib1.a In file included from c_code.c:27:0: $HOME/spack/opt/spack/linux-centos7-broadwell/gcc-7.3.0/openmpi-4.0.3 -ziwdzwh

Re: [OMPI users] include/mpi.h:201:32: error: two or more data types in declaration specifiers

Giles, thank you for your answer on this - my reply seems to have got eaten probably for being too long so I have put it up here: https://gist.github.com/sjpb/680f3781110025ade3dff34390d673c8#file-gnu9-ompi4-em_real-log-L903 it almost looks to me like it's using the wrong compiler or something b