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WeeklyTelcon_20201117

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Geoffrey Paulsen edited this page Jan 19, 2021 · 1 revision

Open MPI Weekly Telecon ---

  • Dialup Info: (Do not post to public mailing list or public wiki)

Attendees (on Web-ex)

  • NOT-YET-UPDATED

4.0.x

  • v4.0.6 toward the end of the month.
    • 7199 - ras based orted on headnode.
    • No other blockers currently on
    • Geoff will create milestone issue for v4.0.6
  • PMIX 3.2
  • We'll need an hwloc version of PR8222.
  • What should we do about Issue 8222
    • Giles extended autotools to patch libtool.
    • PR8222 master late last night. Can easily be cherry-picked.
    • Do we need similar PRs in hwloc and pmix?
      • Probably do.
    • Want to take this back to v4.0.x, and v4.1.x
  • PR 8187 - deterministic build.
    • rhc will review.

v4.1

  • BigSur Fix
  • Joseph mentioned an issue with Adapt and HAN
  • Joseph did post a PR for another fix.

Open-MPI v5.0

  • Ralph is working on updating PMIx / PRRTE submodule pointers.

    • Jeff is helping with configury issues.

  • Hoping these are one-time issues, and not every time we update submodule pointers.

    • All new configury.
    • If this isn't a one-time thing, we should consider stop embedding this.
    • Submodules are good for a number of things, but you ahve to take a change in configury, Go through CI, commit it to PMIx master, then go through OMPI CI, and find out that there's a bug. Then you have to go back to PMIx master.

  • Cisco has some of this.

    • Should figure out a keyword on PMIx side, that effectively does

  • Hit a problem in AWS Amazon-Liunux1 trying to build a tarball.

  • And were hitting Mellanox CI due to Python older version.

  • IBM doesn't do dist check - bug is in there (real issue)

  • Some issues are caused by Embedding. (What do you mean by SRCDIR) (Which SRCDIR?)

  • But other issues are NOT caused by embedding pmix.

    • So getting rid of embedding would not solve these issues

  • Not moment it's looking like 2Q next year.

    • IBM's been pushing on PRRTE as well. We're testing the map/bind options.
    • Trying to push tickets up (some are clarification of expected behavior)
    • Community help with these issues would help move forward the prrte deadline.

  • How's the state of https://github.com/open-mpi/ompi-tests-public/

    • Putting new tests there
    • Very little there so far, but working on adding some more.
    • Should have some new Sessions tests

  • What's going to be the state of the SM Cuda BTL and CUDA support in v5.0?

    • What's the general state? Any known issues?
    • AWS would like to get.
    • Josh Ladd - Will take internally to see what they have to say.
    • From nVidia/Mellanox, Cuda Support is through UCX, SM Cuda isn't tested that much.
    • Hessam Mirsadeg - All Cuda awareness through UCX
    • May ask George Bosilica about this.
    • Don't want to remove a BTL if someone is interested in it.
    • UCX also supports TCP via CUDA
    • PRRTE CLI on v5.0 will have some GPU functionality that Ralph is working on

  • Update 11/17/2020

    • UTK is interested in this BTL, and maybe others.
    • Still gap in the MTL use-case.
    • nVidia is not maintaining SMCuda anymore. All CUDA support will be through UCX
    • What's the state of the shared memory in the BTL?
      • This is the really old generation Shared Memory. Older than Vader.
    • Was told after a certain point, no more development in SM Cuda.
    • One option might be to
    • Another option might be to bring that SM in SMCuda to Vader(now SM)

  • Restructure Tech Doc (more features than Markdown, including crossrefrences)

    • Jeff had a first stab at this, but take a look. Sent it out to devel-list.
    • All work for master / v5.0
      • Might just be useful to do README for v4.1.? (don't block v4.1.0 for this)
    • Sphynx is tool to generate docs from restructured doc.
      • can handle current markdown manpages together with new docs.
    • readthedocs.io encourages "restructured text" format over markdown.
      • They also support a hybrid for projects that have both.
    • Thomas Naughton has done the restructured text, and it allows
    • LICENSE question - what license would the docs be available under? Open-MPI BSD license, or

  • Ralph tried the Instant on at scale:

    • 10,000 nodes x 32PPN
    • Ralph verified Open-MPI could do all of that in < 5 seconds, Instant-On.
    • Through MPI_Init() (if using Instant-On)
    • TCP and Slingshot (OFI provider private now)
    • PRRTE with PMIx v4.0 support
    • SLURM has some of the integration, but hasn't taken this patch yet.

  • Discussion on:

    • Draft Request Make default static https://github.com/open-mpi/ompi/pull/8132
    • One con is that many providers hard link against libraries, which would then make libmpi dependent on this.
    • Talking about amending to request MCAs to know if it should be slurped in.
      • (if the component hard links or dlopens their libraries)
    • Roadrunner experiments... The Bottleneck in launching was I/O in loading all the .sos
      • spindle, and burst buffer reduce this, but still
    • Still going through function pointers, no additional inlining.
      • can do this today.
    • Still different than STATIC (sharing this image across process), just not calling dlopen that many times.
    • New proposal is to have a 3rd option where component decides it's default is to be slurped into libmpi
      • It's nice to have fabric provider's not bring their dependencies into libmpi so that the main libmpi can be run on nodes that may not have the provider's dependencies installed.
    • Low priority thing anyway, if we get it in for v5.0 it'd be nice, but not critical.

Video Presentation

  • George and Jeff are leading
  • No new updates this week (see last week)
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