I would like to discuss MPI_WIN_SHARED_QUERY (https://github.com/mpi-forum/mpi-issues/issues/23) in a future call.  In the past, Bill had issues with this because it would encourage (but not require) implementations to allocate contiguous shared memory in MPI_Win_allocate, whereas today it might allocate noncontiguous shared memory.  I'm not sure if any implementation is actually doing the latter, but I believe this is not a serious issue, since (1) implementations are not required to change (2) Linux NUMA balancing is a thing now.

I will also note that I started sketching out a proposal to construct windows better - https://github.com/mpiwg-rma/rma-issues/issues/22 - that might be a way to escape a lot of the current problems with RMA having way too many features.

Jeff