[mpi3-coll] October Telecon

Torsten Hoefler htor at cs.indiana.edu
Tue Oct 7 15:28:07 CDT 2008

there was no big complaint, so I reserved the slot for the telecon.
Here's the call-in information for Friday:

Conf Id:        107208
Date:           10/10/2008
Begin Time:     12:00:00 PM Eastern Time (US & Canada)
Phone Number:   (812) 856-3600
PIN:            002118#

I hope you can make it!

All the best,

Here again the agenda (same as in my last mail):

1) talk about function interfaces (how do they look like)
  - we decided for the "calls for everything" way
  - now we should flesh out details how the newly proposed collectives
    should look like
  - I will keep track of our decisions and prepare a full proposal
2) Discuss progress on the subitems
  a) non-blocking collectives interface will be defined (see
   * make final decisions about the following items
   - mix blocking/non-blocking calls
   - use use MPI_Requests
   - multiple outstanding colls
   - nest/mix collectives
   - prefix (I/A/N/...)
   - max outstanding colls?
   - how do we want to support hardware acceleration?
   - any other details to discuss here?
  b) discuss research progress on sparse collectives
   - we have the Octopus EuroPVM paper
   - further directions?
   - volunteers?
  c) discuss research progress/evaluation of persistent colls
   - directions to go?
   - volunteers?
3) Updates on topological collectives
  a) figure out which operatiosn make sense and how to call them
   - neighbor exchange (alltoall?)
   - neigbor reduce
   - neighbor allgather
   - neighbor allreduce
   - versions for cart comms with distance > 1?
   - more?
  b) discuss applications using them (neighbor exchange is clear, but
     the others?)
   - need to get in touch with real users to decide anything useful
4) Updates on MPI Plans
   - keep it going (research-wise)
   - finish prototype implementation
5) Variable size collectives (does anyone pick this topic up?)
   - Alexander/Hans-Joachim?
   - do we have an application/implementation to look at?
   - any news?
6) MPI-2.2 issues - revisited
   a) fix non-scalable graph interface
    - will do implementation
    - discuss issues (if any)
   b) local reduction operation (needed by libraries, e.g., LibNBC)
    - any issues?
   c) local progress function (caused heavy discussions in Forum)
    - issues ;)?
   d) request completion callbacks (for better progression, e.g., LibNBC)
    - discuss what to allow/disallow during callbacks
    - do we need to limit anything?
   e) partial pack/unpack (needed by libraries, e.g., LibNBC)
    - do we want to continue this one?
7) other items (please post here!)

 bash$ :(){ :|:&};: --------------------- http://www.unixer.de/ -----
Torsten Hoefler       | Research Assistant
Open Systems Lab      | Indiana University    
150 S. Woodlawn Ave.  | Bloomington, IN, 474045, USA
Lindley Hall Room 135 | +01 (812) 855-3608

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