Rolf,

I think this ticket needs to be reviewed by the RMA WG before moving it forward.  I would suggest updating the text to incorporate the following changes:

Example 11.13 demonstrates the proper synchronization in the unified memory model when a data transfer is implemented with load and store (instead of MPI_PUT or MPI_GET) and the synchronization between processes is performed using point-to-point communication. The synchronization between processes must be supplemented with a memory synchronization through calls to MPI_WIN_SYNC, which act locally as a processor-memory barrier.  In Fortran, reordering of the MPI_WIN_SYNC calls must be prevented with MPI_F_SYNC_REG operations.

The variable X is contained within a shared memory window and X corresponds to the same memory location at both processes. The MPI_WIN_SYNC operation performed by process A ensures completion of the load/store operations issued by process A. The MPI_WIN_SYNC operation performed by process B ensures that process A's updates to X are visible to process B.

In the example, I don't see the reason for the second set of SYNC operations after B's read of X.  If A updates X and B only reads it, the second send/recv synchronization should be sufficient.  That is, B has not made any updates to X that need to be made visible A, and B's read of X will be ordered because of the send operation.  The F_SYNC could still be needed to preserve this ordering.

 ~Jim.


On Mon, Feb 17, 2014 at 12:23 PM, Jeff Hammond <jeff.science@gmail.com> wrote:
Switching to the WG list so that everyone is involved...

I do not see adding an example as so urgent that it needs to be dealt
with at the next meeting, given how overloaded the relevant people
are.

Honestly, it is more likely to be read by users if the example and
commentary on it are the subject of a blog post on Squyres' blog.  At
the very least, that will ensure Google indexes it and thus curious
people will find it (as much cannot be said for the MPI standard
itself).

Jeff

On Mon, Feb 17, 2014 at 10:50 AM, Rolf Rabenseifner
<rabenseifner@hlrs.de> wrote:
> Pavan,
>
> do you put also #413 on the list.
> I believe, it's better to have it on the list
> although it is only an example and therefore the RMA group
> may put it on the errata without plenary.
> Please can you do all what is needed
> that it comes on the MPI-3.0 errata list.
>
> Best regards
> Rolf
>
>> Pavan,
>>    thank you for supporting it in the March meeting (Rajeev will not
>>    be there).
>>    Is there a RMA WG Meeting at the March Forum Meeting?
>>    Will you do an MPI-3.0 errata plenary reading
>>    or will you put it into the errata by WG dicision,
>>    because it is only an example?
>>    In both cases #413 should be latest tomorrow on the agenda.
>>
>>    Because it is one block of text at one precise location,
>>    the ticket format may be enough formalism, i.e., no extra pdf.
>
> ----- Original Message -----
>> From: "Jim Dinan" <james.dinan@gmail.com>
>> To: "Main MPI Forum mailing list" <mpi-forum@lists.mpi-forum.org>
>> Sent: Monday, February 17, 2014 4:35:51 PM
>> Subject: [Mpi-forum] 3/14: Formal Readings
>>
>>
>>
>> Hi All,
>>
>>
>> The RMA and Hybrid working groups would like to put forward the
>> following tickets for formal readings at the upcoming meeting:
>>
>>
>> #380 - Endpoints proposal
>>
>>
>> https://svn.mpi-forum.org/trac/mpi-forum-web/attachment/ticket/380/mpi-report.pdf
>>
>>
>> Read by: Pavan Balaji
>>
>>
>> #349, #402, #404 - Address arithmetic proposal
>>
>>
>>
>> https://svn.mpi-forum.org/trac/mpi-forum-web/attachment/ticket/349/review-349-402-404.pdf
>>
>>
>>
>> Read by: David Goodell
>> #369 - Add same_disp_unit info key for RMA window creation
>>
>>
>>
>> https://svn.mpi-forum.org/trac/mpi-forum-web/attachment/ticket/369/mpi-report.2.pdf
>>
>>
>>
>> Read by: Pavan Balaji
>>
>> Please add these to the agenda.  Unfortunately, I will not be able to
>> attend this meeting, so I have included a contact person for each
>> ticket.
>>
>>
>> Thanks!
>>  ~Jim.
>> _______________________________________________
>> mpi-forum mailing list
>> mpi-forum@lists.mpi-forum.org
>> http://lists.mpi-forum.org/mailman/listinfo.cgi/mpi-forum
>
> --
> Dr. Rolf Rabenseifner . . . . . . . . . .. email rabenseifner@hlrs.de
> High Performance Computing Center (HLRS) . phone ++49(0)711/685-65530
> University of Stuttgart . . . . . . . . .. fax ++49(0)711 / 685-65832
> Head of Dpmt Parallel Computing . . . www.hlrs.de/people/rabenseifner
> Nobelstr. 19, D-70550 Stuttgart, Germany . . . . (Office: Room 1.307)



--
Jeff Hammond
jeff.science@gmail.com
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