Not good:

/labhome/alexm/workspace/openmpi-1.6.1a1hge06c2f2a0859/inst/bin/mpirun --host h-qa-017,h-qa-017,h-qa-017,h-qa-017,h-qa-018,h-qa-018,h-qa-018,h-qa-018 -np 8 --bind-to-core -bynode -display-map /usr/mpi/gcc/mlnx-openmpi-1.6rc4/tests/osu_benchmarks-3.1.1/osu_alltoall

 ========================   JOB MAP   ========================

 Data for node: h-qa-017               Num procs: 4

                Process OMPI jobid: [36855,1] Process rank: 0

                Process OMPI jobid: [36855,1] Process rank: 2

                Process OMPI jobid: [36855,1] Process rank: 4

                Process OMPI jobid: [36855,1] Process rank: 6

 Data for node: h-qa-018               Num procs: 4

                Process OMPI jobid: [36855,1] Process rank: 1

                Process OMPI jobid: [36855,1] Process rank: 3

                Process OMPI jobid: [36855,1] Process rank: 5

                Process OMPI jobid: [36855,1] Process rank: 7

 =============================================================

--------------------------------------------------------------------------

An invalid physical processor ID was returned when attempting to bind

an MPI process to a unique processor.

This usually means that you requested binding to more processors than

exist (e.g., trying to bind N MPI processes to M processors, where N >

M).  Double check that you have enough unique processors for all the

MPI processes that you are launching on this host.

$hwloc-ls --of console
Machine (32GB)
  NUMANode L#0 (P#0 16GB) + Socket L#0 + L3 L#0 (20MB) + L2 L#0 (256KB) + L1 L#0 (32KB) + Core L#0
    PU L#0 (P#0)
    PU L#1 (P#2)
  NUMANode L#1 (P#1 16GB) + Socket L#1 + L3 L#1 (20MB) + L2 L#1 (256KB) + L1 L#1 (32KB) + Core L#1
    PU L#2 (P#1)
    PU L#3 (P#3)