Hello Christoph, it is indeed a good question. I will also take a look at the table w. r. t. inter-communicators. It may have similar caveats for collectives with inter-communicators. Best regards, Julien J. De : mpiwg-hw-topology <mpiwg-hw-topology-bounces@ lists. mpi-forum. org>
ZjQcmQRYFpfptBannerStart
This Message Is From an External Sender
This message came from outside your organization.
 
ZjQcmQRYFpfptBannerEnd

Hello Christoph,


it is indeed a good question.


I will also take a look at the table w.r.t. inter-communicators. It may have similar caveats for collectives with inter-communicators.


Best regards,

Julien J.


De : mpiwg-hw-topology <mpiwg-hw-topology-bounces@lists.mpi-forum.org> de la part de Christoph Niethammer via mpiwg-hw-topology <mpiwg-hw-topology@lists.mpi-forum.org>
Envoyé : mardi 18 mars 2025 09:15:23
À : mpiwg-hw-topology; mpiwg-semantic-terms@lists.mpi-forum.org; MPI-3 Collective Subgroup Discussions
Cc : Martin Schulz
Objet : [mpiwg-hw-topology] Discussing Semantics and Synchronization Requirements for Neighbourhood Collectives
 
Hello everyone, During the preparation for the FRM, a question was raised regarding whether and how the semantics of collectives apply to neighborhood collectives. [1] This question stemmed from remark 18) in the summary table in Appendix A. 2,
ZjQcmQRYFpfptBannerStart
This Message Is From an External Sender
This message came from outside your organization.
 
ZjQcmQRYFpfptBannerEnd
Hello everyone,

During the preparation for the FRM, a question was raised regarding
whether and how the semantics of collectives apply to neighborhood collectives. [1]
This question stemmed from remark 18) in the summary table in Appendix A.2,
which was used to apply the semantics of collectives to neighbourhood
collectives at this place.

The discussions expanded during the March meeting to the question of whether remark 18,
stating that "all-to-all collectives *must* synchronize (with some restrictions)",
is correct. [2]

I would like to invite you all to discuss these two issues in more detail during a 
Topologies WG meeting on March 27th at 15:00, as part of our regular WG slot.

Best regards
Christoph Niethammer

[1] https://urldefense.us/v3/__https://github.com/mpi-forum/mpi-issues/issues/863__;!!G_uCfscf7eWS!edo6G3QE7JbjtZTTusbpg5yIgnpGmlkZf6PJXEhK0BIFo_p25xzgJ-iVjVZhEuL7z3exLA62R0MjXhpEVDjC5QAigTtN4tiyDa1MnE8$
[2] https://urldefense.us/v3/__https://github.com/mpi-forum/mpi-issues/issues/971__;!!G_uCfscf7eWS!edo6G3QE7JbjtZTTusbpg5yIgnpGmlkZf6PJXEhK0BIFo_p25xzgJ-iVjVZhEuL7z3exLA62R0MjXhpEVDjC5QAigTtN4tiyWCbeaNg$

--

Dr.-Ing. Christoph Niethammer
High Performance Computing Center Stuttgart (HLRS)
Nobelstrasse 19
70569 Stuttgart

Tel: ++49(0)711-685-87203
email: christoph.niethammer@hlrs.de
https://urldefense.us/v3/__https://www.hlrs.de/people/christoph-niethammer__;!!G_uCfscf7eWS!edo6G3QE7JbjtZTTusbpg5yIgnpGmlkZf6PJXEhK0BIFo_p25xzgJ-iVjVZhEuL7z3exLA62R0MjXhpEVDjC5QAigTtN4tiyVz0SIxo$