On Jan 11, 2016, at 8:32 AM, Bennet Fauber <ben...@umich.edu> wrote: > > We have an issue with binding to cores with some applications and the > default causes issues. We would, therefore, like to set the > equivalent of > > mpirun --bind-to none > > globally. I tried search for combinations of 'openmpi global > settings', 'site settings', and the like on the web and ended up > several times at > > https://www.open-mpi.org/faq/?category=sysadmin#sysadmin-mca-params > > That makes it look very much like MCA parameters are for network > settings; see, specifically, section 4. What are MCA Parameters? Why > would I set them?
To add on to what Ralph said, perhaps we should update this FAQ entry a bit: setting MCA parameters applies to *any* MCA parameters -- not just the network-centric ones. I.e., any param you can set on the mpirun command line via --mca, you can also set via environment variable and/or file setting (there's one or two notable exceptions to this rule, but they're corner case / way off in the weeds kinds of parameters that can *only* be read via environment variable, because they must be read before main() starts -- you probably don't care about these). Additionally, some mpirun command line parameters (like --bind-to and friends) are simply synonyms for MCA parameters. We did this simply because while (most?) users find --friendly-option easier to set than an MCA parameter name, we wanted to give the flexibility to sysadmins to be able to set them on a global basis (e.g., exactly the use case you are asking about). > [snip] > The web version of the man page is for 1.8.8, and it agrees with the > installed man page for our 1.8.7. However, it appears that our system > man page for mpirun(1) for OpenMPI 1.8.2 has slightly different > parameters. Specifically, To +1 on what Ralph said: I believe we changed our back-end process affinity system starting in the v1.7 series somewhere, and also changed the mpirun command line options (e.g., from --bycore/--bysocket to --map-to, ...and friends). I think we forgot to update mpirun(1) by v1.8.2, but eventually updated it <= v1.8.8. -- Jeff Squyres jsquy...@cisco.com For corporate legal information go to: http://www.cisco.com/web/about/doing_business/legal/cri/
