[Mpi3-rma] MPI-3 UNIFIED model clarification

[Jed Brown]

"Sur, Sayantan" <sayantan.sur at intel.com> writes:
> If we require apps working with UNIFIED model to call MPI_Win_sync, an
> one-sided PGAS language might be forced to call sync for any buffer
> that may have been touched remotely. Thereby potentially causing some
> performance degradation.

They need a memory fence anyway on most architectures.

What is the problem with creating a fast path for MPI_Win_sync with
UNIFIED?  Are we crying about 10 cycles (function call/fast path) along
with an explicit statement that (architecture-specific) memory fences
could be used directly if the caller wants that responsibility?
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 835 bytes
Desc: not available
URL: <http://lists.mpi-forum.org/pipermail/mpiwg-rma/attachments/20130730/fb5e4d64/attachment-0001.pgp>