Update PMIx to v2.1.0

[rhc54]

Need to refresh PMIx in OMPI v3.1.0 prior to release - should only be an internal-to-PMIx update, but needed to ensure backward compatibility with earlier PMIx and OMPI releases.

Will try to complete ASAP.

[rhc54]

Waiting on openpmix/openpmix#586

[rhc54]

@bwbarrett @jsquyres I was going to provide a vanilla version of the official PMIx v2.1.0 release. However, it just hit me that the cleanup registration code won't be in that release - it involved adding attributes etc that moved it into PMIx v3.

Do you want the cleanup code here? It solves the problem of leftover files in /dev/shm, which is why I ask. Would mean taking the embedded pmix code currently in master.

[karasevb]

openpmix/openpmix#586 was closed, and related PRs are merged openpmix/openpmix#613, openpmix/openpmix#614.

[karasevb]

@rhc54 Do we have any other blockers to update PMIx?

[rhc54]

Not that I know of, but I do need to resolve the question I posted above.

[karasevb]

@rhc54 can we sync PMIx v2.1 early than mentioned feature will be resolved? Since we faced the failure during testing with internal PMIx which was fixed here openpmix/openpmix#614.

[rhc54]

I'm afraid Monday is a national holiday over here, so I don't know who will be around. I suspect this will at least need to wait until Tues or Wed before anything could be committed, regardless.

[artpol84]

@rhc54 Let's discuss this on Todays call.

[jladd-mlnx]

@karasevb since Ralph is no longer working on the OMPI project, please do the merge.

@alinask @artpol84 FYI...