Thanks, I definitely appreciate the new, hotness of hwloc. I just couldn't tell from the documentation or the web page how or if it was being used by OpenMPI.
I still work with OpenMPI 1.4.x and now that I've looked into the builds, I think I understand that PLPA is used in 1.4 and hwloc is brought in as an MCA module in 1.6.x. Re: layering, I believe you are saying that the relationship to libnuma is not one where hwloc is adding higher-level functionalities to libnuma, but rather hwloc is a much improved alternative except for a few system calls it makes via libnuma out of necessity or convenience. Thanks
