September 2018 - mpiwg-rma - mailman3.cels.anl.gov

Re: [mpiwg-rma] Summary of MPI RMA WG meeting on Sept 21, 2018
by William Gropp 21 Sep '18

21 Sep '18

An amendment - the Shared-query has a full proposal, see https://github.com/mpiwg-rma/mpi-standard/commit/fcfa116935376d65f3bb28332d… . We need volunteers to read it carefully and review it. Bill William Gropp Director and Chief Scientist, NCSA Thomas M. Siebel Chair in Computer Science University of Illinois Urbana-Champaign > On Sep 21, 2018, at 8:52 AM, William Gropp via mpiwg-rma <mpiwg-rma(a)lists.mpi-forum.org> wrote: > > MPI RMA Working Group Meeting > September 21, 2018 > Barcelona, Spain > > (I couldn’t find the RMA wiki - did this never get migrated?) > > Here are my notes. For those present, please let me know if I missed anything. > > - Interoperability of MPI shared memory with C11, C++11 language semantics. Lead: Bill Gropp > > No document. > > Discussion. WG agreed that MPI should remain as consistent as possible with the language standards as they go forward, noting that there are still limitations in their descriptions of shared memory. > > - MPI Generalized atomics. Lead: Pavan Balaji > > PDF attached. > > Generally positive response to the text. A few suggestions were made: > For accumulate_op - allow compare-and-swap (CAS) with another op (as an option) > For which_accumulate_op - Consider a comma-separated list of operators > for accumulate_max_bytes. There was a discussion about whether this should be count or bytes, and how exactly to describe what the max means in terms of parameters to the accumulate operations. > > - Neighborhood communication in RMA. Lead: Nathan Hjelm > > No document. > > Nathan presented the basic ideas, which is the use of the topology attached to a communicator to limit the permitted communication partners, and thus simplify and reduce the memory requirements in the implementation. > > The WG was interested, and on a straw vote of 6-0-2, asked for a more detailed presentation (e.g., a Powerpoint, not yet a written standard proposal), > > - Nonblocking RMA synchronization. Lead: Pavan Balaji > > No document, but this might be absorbed by TonyS's proposal. > > The WG would like a top-level conceptual discussion of this in the context of MPI. > > - RMA Notify. Leads: Jim and Torsten > > https://github.com/mpi-forum/mpi-issues/issues/59 <https://github.com/mpi-forum/mpi-issues/issues/59> > > Some discussion. Noted that the state-of-the-art has advanced since the last discussion in detail by the working group. The WG, on a 7-0-1 straw vote, would like an update to the possible options here. It was also noted that Bull is experimenting with different options in different systems, and may be able to share the results in a few months. > > One question to consider is the pros and cons of using requests as the notification mechanism; it was noted that one pragmatic if not elegant solution might be to allow both a heavy (e.g., MPI_Request) and lightweight (e.g., memory variable) notification approach. > > - MPI_IN_PLACE semantics for collectives on shared memory. Lead: Pavan Balaji > > PDF attached. > > This was reviewed by the WG. When asked whether there was interest in a document with a usage example and discussion of benefits, the WG voted no in a straw poll with 0-4-2 (and 2 not voting). > > - Relax constraints on MPI_WIN_SHARED_QUERY. Lead: Jeff Hammond > > https://github.com/mpi-forum/mpi-issues/issues/23 <https://github.com/mpi-forum/mpi-issues/issues/23> > > The WG found support for this and voted 5-1-2 for a full written proposal > > - Add flush_thread synchronization calls. Lead: Nathan Hjelm > > No document. > > Nathan presented this and the WG voted 7-0-2 for a more detailed (e.g., a Powerpoint) description. > > The WG would like to see the written proposals for generalized atomics and shared_query in time for reading at the December MPI Forum meeting. > > > The WG adjourned after discussing these items. > > William Gropp > Director and Chief Scientist, NCSA > Thomas M. Siebel Chair in Computer Science > University of Illinois Urbana-Champaign > > > > > > > _______________________________________________ > mpiwg-rma mailing list > mpiwg-rma(a)lists.mpi-forum.org > https://lists.mpi-forum.org/mailman/listinfo/mpiwg-rma

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Summary of MPI RMA WG meeting on Sept 21, 2018
by William Gropp 21 Sep '18

21 Sep '18

MPI RMA Working Group Meeting September 21, 2018 Barcelona, Spain (I couldn’t find the RMA wiki - did this never get migrated?) Here are my notes. For those present, please let me know if I missed anything. - Interoperability of MPI shared memory with C11, C++11 language semantics. Lead: Bill Gropp No document. Discussion. WG agreed that MPI should remain as consistent as possible with the language standards as they go forward, noting that there are still limitations in their descriptions of shared memory. - MPI Generalized atomics. Lead: Pavan Balaji PDF attached. Generally positive response to the text. A few suggestions were made: For accumulate_op - allow compare-and-swap (CAS) with another op (as an option) For which_accumulate_op - Consider a comma-separated list of operators for accumulate_max_bytes. There was a discussion about whether this should be count or bytes, and how exactly to describe what the max means in terms of parameters to the accumulate operations. - Neighborhood communication in RMA. Lead: Nathan Hjelm No document. Nathan presented the basic ideas, which is the use of the topology attached to a communicator to limit the permitted communication partners, and thus simplify and reduce the memory requirements in the implementation. The WG was interested, and on a straw vote of 6-0-2, asked for a more detailed presentation (e.g., a Powerpoint, not yet a written standard proposal), - Nonblocking RMA synchronization. Lead: Pavan Balaji No document, but this might be absorbed by TonyS's proposal. The WG would like a top-level conceptual discussion of this in the context of MPI. - RMA Notify. Leads: Jim and Torsten https://github.com/mpi-forum/mpi-issues/issues/59 <https://github.com/mpi-forum/mpi-issues/issues/59> Some discussion. Noted that the state-of-the-art has advanced since the last discussion in detail by the working group. The WG, on a 7-0-1 straw vote, would like an update to the possible options here. It was also noted that Bull is experimenting with different options in different systems, and may be able to share the results in a few months. One question to consider is the pros and cons of using requests as the notification mechanism; it was noted that one pragmatic if not elegant solution might be to allow both a heavy (e.g., MPI_Request) and lightweight (e.g., memory variable) notification approach. - MPI_IN_PLACE semantics for collectives on shared memory. Lead: Pavan Balaji PDF attached. This was reviewed by the WG. When asked whether there was interest in a document with a usage example and discussion of benefits, the WG voted no in a straw poll with 0-4-2 (and 2 not voting). - Relax constraints on MPI_WIN_SHARED_QUERY. Lead: Jeff Hammond https://github.com/mpi-forum/mpi-issues/issues/23 <https://github.com/mpi-forum/mpi-issues/issues/23> The WG found support for this and voted 5-1-2 for a full written proposal - Add flush_thread synchronization calls. Lead: Nathan Hjelm No document. Nathan presented this and the WG voted 7-0-2 for a more detailed (e.g., a Powerpoint) description. The WG would like to see the written proposals for generalized atomics and shared_query in time for reading at the December MPI Forum meeting. The WG adjourned after discussing these items. William Gropp Director and Chief Scientist, NCSA Thomas M. Siebel Chair in Computer Science University of Illinois Urbana-Champaign

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Declined:RMA WG Biweekly Telecon
by Sameh S Sharkawi 14 Sep '18

14 Sep '18

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RMA WG recurring telecon
by Balaji, Pavan 14 Sep '18

14 Sep '18

To join the Meeting: https://bluejeans.com/173205081/3141592 To join via Room System: Video Conferencing System: bjn.vc -or-199.48.152.152 Meeting ID : 173205081 Participant Passcode : 3141592 To join via phone : 1) Dial: +1.408.317.9254 (US (San Jose)) +1.866.226.4650 (US Toll Free) (see all numbers - http://bluejeans.com/numbers) 2) Enter Conference ID : 173205081 3) Enter Participant Passcode : 3141592

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RMA WG recurring telecon
by Balaji, Pavan 14 Sep '18

14 Sep '18

Biweekly telecon using Blue Jeans: http://argonne.bluejeans.com/balaji.anl.gov

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Re: [mpiwg-rma] RMA WG recurring telecons
by Balaji, Pavan 14 Sep '18

14 Sep '18

Sorry, folks, that should be 2-3pm central time biweekly starting on 9/24. I've deleted the old entry and created a new one. Sorry for the spam. -- Pavan > On Sep 14, 2018, at 9:49 AM, Balaji, Pavan via mpiwg-rma <mpiwg-rma(a)lists.mpi-forum.org> wrote: > > All, > > I've setup RMA WG recurring telecons from 3-4pm central time starting on 9/24. Sorry for the small error in the calendar invite that I have now corrected. If it doesn't show up as a biweekly recurring telecon starting on 9/24, please let me know. > > Thanks, > > -- Pavan > > _______________________________________________ > mpiwg-rma mailing list > mpiwg-rma(a)lists.mpi-forum.org > https://lists.mpi-forum.org/mailman/listinfo/mpiwg-rma

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RMA WG recurring telecon
by Balaji, Pavan 14 Sep '18

14 Sep '18

Biweekly telecon using Blue Jeans: http://argonne.bluejeans.com/balaji.anl.gov

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Canceled: RMA WG Biweekly Telecon
by Balaji, Pavan 14 Sep '18

14 Sep '18

Biweekly telecon using Blue Jeans: http://argonne.bluejeans.com/balaji.anl.gov

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RMA WG recurring telecons
by Balaji, Pavan 14 Sep '18

14 Sep '18

All, I've setup RMA WG recurring telecons from 3-4pm central time starting on 9/24. Sorry for the small error in the calendar invite that I have now corrected. If it doesn't show up as a biweekly recurring telecon starting on 9/24, please let me know. Thanks, -- Pavan

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Canceled: RMA WG Biweekly Telecon
by Balaji, Pavan 14 Sep '18

14 Sep '18

Biweekly telecon using Blue Jeans: http://argonne.bluejeans.com/balaji.anl.gov

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