[mpiwg-rma] FW: [Mpi3-rma] [EXTERNAL] Re: MPI-3 UNIFIED model updates

Pavan Balaji balaji at mcs.anl.gov
Tue Aug 27 13:19:20 CDT 2013

On 08/27/2013 12:57 PM, Jeff Hammond wrote:
> The MPI standard will not define by what mechanism the SHMEM
> implementation will establish the necessary consistency.  This is what I
> mean by undefined = implementation-defined.  I do not think that Keith
> is proposing to enumerate all processor memory models and the
> appropriate fences required to achieve the affect of win_sync but at
> lower cost.  Thus, it is the implementation - or perhaps more
> accurately, the platform on which the implementation resides - that will
> define these semantics.

Here's what I understood from Keith --

He wants a statement in the standard that says the application can do 
platform-specific memory consistency to synchronize the public and 
private windows in UNIFIED.

I do agree that that's a very flimsy statement and doesn't really mean 
much.  But I'm calling it a definition, while I think you are saying 
that it's pretty much undefined.

I like leaving it totally undefined better than the above "definition".

  -- Pavan

Pavan Balaji

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