WeeklyTelcon_20160517

Open MPI Weekly Telcon

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

Attendees

• Geoff Paulsen
• Jeff Squyres
• Brad Benton
• Howard
• Josh Hursey
• Joshua Ladd
• Nathan Hjelm
• Ralph
• Sylvain Jeaugey
• Todd Kordenbrock

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Agenda

Review 1.10

• Milestones: https://github.com/open-mpi/ompi-release/milestones/v1.10.3
• 1161 - Open IB Error Path - Giles asked Mike to review, in 2nd iteration.
  • Joshua Ladd tagged on 2.x version.
• 1150 - 2 places in Init and 1 in Finalize where we do RTE Barrier.
  • If launched with mpirun, it works just fine.
  • But direct launch will hang in cray or slurm PMIx because those have Blocking RTE barriers, and those DONT progress.
  • Patched it in master with MPI Barrier to make other things progress.
  • Will need to block 2.0.x for this fix also. Ralph will create PR.
• Once these get in, Do another RC and move this out.

Review 2.0.x

• Wiki: https://github.com/open-mpi/ompi/wiki/Releasev20
• Blocker Issues: https://github.com/open-mpi/ompi/issues?utf8=%E2%9C%93&q=is%3Aopen+milestone%3Av2.0.0+label%3Ablocker
• Milestones: https://github.com/open-mpi/ompi-release/milestones/v2.0.0
  • PMIx barrier
  • Nathan will review 1164.
  • PR 1673 Multi-threaded issues that George ran into is a doozie.
    • Free path in C++. In one thread in dereg hooks in Delete.
    • Another thread was try to allocate space, and trigerring internal garbage collection.
    • Classic deadlock.
    • Nathan reworked the rcache / mpool code to not hold lock while doing deletes.
    • All locks are always on in RDMA because no way around it.
    • Last rcache bug was if you had > 100 registrations associated with memory registration being munmapped, ran into infinite loop.
    • Nathan and George testing.
    • IBM will do some multi-threaded testing as well.
  • PowerPC issues as well. Nathan had to revise table a bit.
    • ppc64le, if you do a dlsym, pointer is into table of contents: 1 is real address.
      • problem is TOC is getting patched.
    • when patching, need to patch the real function, not the other.
    • ppc64BE - may still
  • 1162 - multiple threads make same endpoint simultaneously.
    • Nathan thought he handled that case.
  • one thing we forgot to do for 2.0.0rc2, we forgot to send to users-alias. Will do for rc3.
    • Put announcement about Migration guide into Announcement list.

Review Master MTT testing (https://mtt.open-mpi.org/)

• IBM trying to ramp up MTT testing. Hopefully will have Power8 XL compiler testing soon.
  • Some issues passing certain flags to XL compilers. Josh Hersey is working on.
• Cisco / Intercomm create failures.
• Getbyte offset test requires v2.0.0 or greater and spins until timeout on 1.10.

MTT Dev status:

Status Updates:

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Status Update Rotation

1. Mellanox, Sandia, Intel
2. LANL, Houston, IBM
3. Cisco, ORNL, UTK, NVIDIA

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