MPI 4.1 - implement memory allocation kind info

[hppritcha]

This is a biggy and likely important to customers using Open MPI with GPU accelerators.

See mpi-forum/mpi-issues#580
and entry 17 of section B.1.2 of the MPI 4.1 standard

[edgargabriel]

Details:

• section 11.4.3 (Memory Allocation Info) of MPI 4.1 contains the description of the MPI memory allocation kinds concept
• section 11.5 (Portable MPI Process Startup) contains the new argument to pass memory allocation kind to mpiexec
• Side document (https://github.com/mpi-forum/mem-alloc) contains the name of the info values for the various accelerators (cuda, rocm, ze)

[rhc54]

Just an FYI: you'll need to add an attribute definition to the PMIx standard if you want this to work with OMPI v5 and above - putting something in the MPIR side doc won't do anything for you, I'm afraid. I will add a PMIX_MEM_ALLOC_KIND definition to the PMIx library just so the support exists. The debugger guys look at the PMIx Standards doc, so somebody needs to get that added to it.

[rhc54]

Also, could you perhaps add the list of the info values you mention (in case we need attributes for those too)? I can't leaf thru that side doc repo to find them, and they aren't shown anywhere obvious.

[hppritcha]

related to openpmix/prrte#1972

[rhc54]

I have added the PMIx support and support for PMIx-based tools in PRRTE: see openpmix/prrte#1973 and openpmix/openpmix#3342. Still not sure if we need to worry about defining attributes for your identified values - is there such a need?