mpi_yield_when_idle setting from etc/openmpi-mca-params.conf is ignored in 4.0.0

[iassiour]

Hi ,

I have set "yield when idle" in etc/openmpi-mca-params.conf

tail openmpi-mca-params.conf

plm_rsh_agent = rsh
rmaps_base_oversubscribe = 1
hwloc_base_binding_policy = none
mpi_yield_when_idle = 1

However the setting seems to be ignored.

I get 100 % us 0% sys for processes waiting on MPI calls.

But if I set the environment variable:

setenv OMPI_MCA_mpi_yield_when_idle 1

or
mpirun --mca mpi_yield_when_idle true

I get the more expected 15% us 85 % sys.

Could someone please check that the setting is read from the configuration file as expected.

[jsquyres]

You may not have gotten an email about it, but @ggouaillardet proposed a PR about this -- see #6440.

[iassiour]

Greetings jsquyres ,

Thanks, Could you please let me know what future minor version of ompi will have this fix.

[gpaulsen]

@hppritcha should just cherry-pick the original #6440 fix to v4.0.x for inclusion into v4.0.3 ?