Meeting - 27th June 2018

Protocol of the GASPI Forum meeting on June, 27th, 2018, Frankfurt/Main

Date: 2018.01.10
Location: Frankfurt/Main, Wilhelm-Fay Straße 54
Start: 13:00h
End: 16:00h

Participants:

  • Fraunhofer ITWM (Daniel Grünewald)
  • ZIH, TU Dresden (Christian Herold)
  • DLR (Olaf Krzikalla)
  • LRZ (Andre Wortman)
  • GWDG (Vanessa End)
  • IMEC (Tom van der Aa)
  • T-Systems SfR (Christian Simmendinger)

Agenda:

13.00-13.30 Attendees, Quorum, next Forum meeting, Actions Items
13.30-14.00 Errata proposals
14.00-14.15 Lunch break
14.15-15.00 General text proposals
15.00-15.15 Voting
15.15-16.00 GASPI Context, Migration from legacy codes, Shared GASPI Windows,
GASPI Standard Library, Task model integration for GASPI, fine grain
local completion.

Errata Proposals

General Text Proposals

Discussion

Daniel: Fine grain local completion

  • Solution 1 - every task using different queue
  • Solution 2 - check every request
  • Solution 3 - remote reply to notification

  • Solution 4 -generic meta comm struct.
  • Additional comm requests:
    • gaspi_post_comm(struct*)
    • gaspi_wait_comm(struct*)

Discussion

  • Is there a remote race ? Local completion does not yet solve a potential remote race. Not equivalent to remote reply to notification.
  • Can we add the concept of context in addition to a tag ?
  • Should this concept include collectives ? (probably not)
  • Is there potential for optimization (re-use of strcut, similar to persistant MPI communication )
  • Implementation: Should the current functions go into a GASPI library layer (as a wrapper function) ?
  • Should we then add tag calls as additonial layer in GASPI standard ?
    • write - tag with notify for group of tags vs write_notify, local_waitsome ?
  • What would waitig for queue imply ? Waiting for all requests in comm_structs ?

TODO

Daniel:

  • Investigate feasability of fine grain completion in cray implementation

BSC + Daniel:

  • C++ async wait c# - how would this fit with GASPI.
  • Remote race
  • OpenMP tasking.

Olaf:

  • gaspi_write_notify, errata for empty message. (notification must be send)

Rui, Mirko:

  • Is it possible to set a gaspi config such that queues are ressouce which is requested ?
  • is it possible to aggregate ressources requested with subsequent calls to gaspi_proc_init ?

Tutorials / Hackathon

  • Still investigating workshop/hackathon @ CSC Finland

Next meeting:

  • Jan, 16 2018 in Frankfurt
Written on June 27, 2018