Meeting 2011 05

Logistics

• Dates: May 3-5, 2011 (Tuesday - Thursday)
• Time: 9 am - 5 pm Eastern each day
• Location: ORNL, Oak Ridge, TN

Audio, video, and screen conferencing is available via WebEx -- see below for details.

Details on location

• The meeting will be held at ORNL.
  • Driving Directions

Hotels

• Oak Ridge Hotels
• There are other hotels in the Turkey Creek/West Knoxville area that are also relatively close to the lab. (Google Map)

Topics

Below are the agenda items that I have gathered so far (in no particular order):

• MPI 2.2 implementation tickets
• MPI 3.0 implementation planning
• ORNL: Hierarchical Collectives discussion
• Runtime integration discussion
• New Process Affinity functionality
  • New user interface
  • Possibly implementation details
• Update on ORTE development
  • State machine overview and discussion
• Fault tolerance feature development and integration (C/R, logging, replication, FT-MPI, MPI 3.0, message reliability, ...)
  • Survey what is: (working, not working, not supported)
    • Available in the trunk
    • Available in a current release
    • In development
  • Update on the sensor framework
  • Create a FAQ entry for each supported FT technique, and how to use it
  • Is there anything we can share regarding code in development
• Threading design discussion
  • Threading in the point-to-point stack (PML/BML/BTL/MPool)
  • Other threading problem areas (e.g., Attribute locking issue that emerged with ROMIO)
  • What level of MPI_THREAD_MULTIPLE do we want to (can we practically) support?
  • NUMA safety issues (e.g., write/read barriers)
  • George's work on threading in the TCP BTL
• Testing infrastructure (MTT)
  • Discuss current setup, and state of testing
  • Review individual MTT setups
  • Discuss automated testing of command line/MCA options (coverage tracking)
• MPI Extensions Update
• ORTE Shared Memory Update

Additional topics that folks might want to discuss - Is there anyone that wants to include these and lead their discussions?:

• Performance tuning (Point-to-point and/or Collective)

Participants

• Brian Barrett (Sandia)
• Wesley Bland (UTK)
• Shiqing Fan (HLRS)
• Rich Graham (ORNL)
• Samuel Gutierrez (LANL)
• Nathan Hjelm (LANL)
• Josh Hursey (ORNL)
• Yevgeny Kliteynik (Mellanox)
• Pavel (Pasha) Shamis (ORNL)
• Jeff Squyres (Cisco)
• Bin Wang (Auburn University)

Agenda

Below is a sketch of the agenda. It will be finalized the week before the meeting, but is always subject to change.

• Tuesday, May 3 (Building 5100 Room 262)
  • Note: We will not be having the Open MPI Teleconference.
  • Webex password: ompi, (stale link)

Start	End	Leader	Topic
9:00 am	9:30 am	All	Logistics, etc
9:30 am	Noon	All	MPI 2.2 and 3.0 Implementation Tickets and Planning
Noon	1:00 pm	-- Lunch --
1:00 pm	2:00 pm	ORNL	Hierarchical Collectives discussion
2:00 pm	3:00 pm	Oracle/Cisco/ORNL	New Process Affinity functionality
3:00 pm	3:30 pm	-- Break --
3:30 pm	5:00 pm	ALL	Testing Infrastructure (MTT)

• Wednesday, May 4 (Building 5100 Room 262)
  • Webex password: ompi, (stale link)

Start	End	Leader	Topic
9:00 am	Noon	IBM/All	Threading Design
Noon	1:00 pm	-- Lunch --
1:00 pm	2:00 pm	NVIDIA	CUDA Support
2:00 pm	3:00 pm	Cisco	ORTE Development Update
3:00 pm	3:30 pm	-- Break --
3:30 pm	5:00 pm	ORNL	Runtime integration discussion

• Thursday, May 5 (Building 5700 Room L202)
  • Webex password: ompi, (stale link)

Start	End	Leader	Topic
9:00 am	Noon	IBM/All	Threading Design (as needed)
10:30 am	11:00 am	ORNL/Cisco	MPI Extensions Update
Noon	1:00 pm	-- Lunch --
1:00 pm	2:00 pm	LANL/Cisco/UTK	ORTE Shared Memory Update
2:00 pm	3:00 pm	All	Wrap up and next steps discussion
3:00 pm	3:30 pm	-- Break --
3:30 pm	5:00 pm	ORNL	Fault tolerance feature development and integration

Results of Discussions

Tuesday:

• MPI 2.2 Report: {18}
  • Need to create a custom report for both 2.2 and 3.0 pending tickets for quick reference. (Done - Josh)
  • trac ticket 1368: Projected to be less than a day of work. A summer student at ORNL might be available.
  • trac ticket 2221: Algorithm addition for MPI_IN_PLACE in MPI_Exscan. Rolf/Nvidia might have some cycles to look into this.
  • trac ticket 2223: Jeff/Cisco has it half integrated in a bitbucket branch. 1-2 weeks of work left for someone to finish it off.
  • trac ticket 2699: George/UTK thinks it is ready. Jeff to follow-up.
• MPI 3.0 {17}
  • trac ticket 2715: Non-blocking collectives work ongoing at ORNL.
  • trac ticket 2716: Brian/Sandia to take a look at re-integration of the tmp branch. For 'ob1' it is just a bit of cleanup. But for 'cm' it may not be able to be implemented until the hardware catches up, so err_not_implemented will likely be returned.
  • Long term items that could be voted on this year.
    • New RMA: Needs progress thread support... Brian/Sandia to lead this effort
    • Tools: Jeff/Cisco to look into who might be interested in implementing (talk to HLRS)
    • Fault Tolerance: ORNL is leading the working group and the Open MPI prototype. More on this on Thursday.
    • Fortran: Craig/LANL is working on a prototype
    • MPI_Count: ??
    • Timers: Jeff/Cisco to look into this if it passes.
    • MPI const: Jeff/Cisco to look into this if it passes.
• Hierarchical Collectives
  • Lots of good stuff presented from a couple of accepted and out-going papers. I'll leave the rest of the notes for those papers.
• Affinity
  • Intention is to create a single, flexible mapper then build the common abstraction on top of it. This eases the maintainability burden on ompi developers.
  • The proposed algorithm is a bit complex.
  • Slides presented will be made available on demand.
  • Josh/ORNL, Jeff/Cisco and Terry/Oracle are working on writing this up at the moment.
  • Items to look at:
    • Ordering as a separate step.
    • Stride is useful in multithreaded application that does not allocate threads with respect to specific cache levels or hardware boundaries.
• MTT Testing
  • Introduced a few new members to how to setup and run MTT
  • Not much outside of that was discussed regarding testing.

Wednesday:

• TBD

Thursday:

• TBD