Hui Zhou

Try configuring mpich with `--enable-thread-cs=global` and see if you can recover the performance. One change we made from 4.0 to 4.1 is switching from global lock to per-vci lock. Per-vci...

@pikrog Could you try set `FI_PROVIDER=tcp`? Anyway, your issue is different form OP, if the issue persist, please open a new issue for better tracking.

> cc @raffenet , @hzhou Sorry for the delay in response. I haven't got a chance to reproduce your issue yet. I am surprised that the global critical section didn't...

> @hzhou, could you also answer this question? > > > Btw, is there a guide on how to configure mpich as much efficient as possible? There are indeed many...

test:mpich/ch3/most

@sonjahapp Is there any measurement on the impact of PMIx event threads, for example, on a fully subscribed situation?

@sonjahapp A few notes -- * If only the "mpi://WORLD" and "mpi://SELF" need be specialized to per-session, we could just single them out directly in the code as currently in...

> @hzhou > > > If only the "mpi://WORLD" and "mpi://SELF" need be specialized to per-session, we could just single them out directly in the code as currently in `main`,...

As we discussed offline, here are the action items: 1. Remove the Pset array for `world` and `self`, instead, add corresponding variables to the session struct itself 2. Use a...

Thanks @sonjahapp . I drew following diagram for my understanding:  Thus we will need a "global" (e.g. in MPIR_PMI) mapping facility to map from PMIx Process ID to world...