Hi Guillaume, Thanks for your interest in MPI Sessions. The hwloc concepts seem to be very promising and it will be interesting to investigate if MPI Sessions is a good way to expose that functionality/knowledge to users. The Sessions WG wiki page is here: https://github.com/mpiwg-sessions/sessions-issues/wiki <https://github.com/mpiwg-sessions/sessions-issues/wiki> The long slide-deck (originally presented to Forum in Chicago Feb 2016 and frequently modified since) is here: https://github.com/mpiwg-sessions/sessions-issues/wiki/2016-12-12-webex/2016... <https://github.com/mpiwg-sessions/sessions-issues/wiki/2016-12-12-webex/2016-12-12-webex.pptx> I have written up my notes from the Sessions WG time here: https://github.com/mpiwg-sessions/sessions-issues/wiki/2017-03-01-forum <https://github.com/mpiwg-sessions/sessions-issues/wiki/2017-03-01-forum> My calendar tells me the next teleconference meeting for the Sessions WG should be Monday (i.e. 6th March 2017) 1pm Eastern US time (which is 6pm UK time). The webex URL is on the wiki page. Cheers, Dan. The University of Edinburgh is a charitable body, registered in Scotland, with registration number SC005336.