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<meta http-equiv="Content-Type" content="text/html; charset=utf-8"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class="">Hi devs,<div class=""><br class=""></div><div class="">Could someone with knowledge about this explain to me how parallel communicators work in yt? </div><div class=""><br class=""></div><div class="">I’m trying to adjust the chunk size for grid geometries using the size of the communicator, see line 361 here:</div><div class=""><br class=""></div><div class=""><a href="https://bitbucket.org/jzuhone/yt-3.x/src/1307a7103665a9b2563050e9bba05f0f96d8715c/yt/geometry/grid_geometry_handler.py?at=yt" class="">https://bitbucket.org/jzuhone/yt-3.x/src/1307a7103665a9b2563050e9bba05f0f96d8715c/yt/geometry/grid_geometry_handler.py?at=yt</a></div><div class=""><br class=""></div><div class="">where I’m trying to determine the size of the communicator using this:</div><div class=""><br class=""></div><div class="">nproc = ytcfg.getint("yt", "__topcomm_parallel_size”)</div><div class=""><br class=""></div><div class="">For an 8-processor job, I expect this to be nproc = 8, but it’s not. I’m generating chunks in photon_simulator from a data source and then iterating over them using parallel_objects, see lines 91-93, 108 of:</div><div class=""><br class=""></div><div class=""><a href="https://bitbucket.org/jzuhone/yt-3.x/src/1307a7103665a9b2563050e9bba05f0f96d8715c/yt/analysis_modules/photon_simulator/photon_models.py?at=yt" class="">https://bitbucket.org/jzuhone/yt-3.x/src/1307a7103665a9b2563050e9bba05f0f96d8715c/yt/analysis_modules/photon_simulator/photon_models.py?at=yt</a></div><div class=""><br class=""></div><div class="">I realize this is a little obtuse, but can someone flesh this out for me, and tell me how to get the size I’m looking for in this case?</div><div class=""><br class=""></div><div class="">Best,</div><div class=""><br class=""></div><div class="">John Z</div></body></html>