[mpiwg-rma] RMA Errata

[Jim Dinan]

#1 -- The effective target rank of load/store operations is currently not
defined on shared memory windows.  That statement may seem like nonsense.
However, it is important for situations where load/store operations
interact with RMA operations that do have an explicit target rank (e.g.
lock/unlock).  I believe this was an oversight, and we intended that the
load/store operations target the rank that allocated the memory.

#2 -- Yes, sounds like we are in agreement

 ~Jim.

On Mon, Jan 19, 2015 at 2:44 PM, William Gropp <wgropp at illinois.edu> wrote:

> My preference is that load/store access follows the language rules for
> shared memory (I think that is what #1 means).  I don’t think anything else
> is viable.
>
> For #2, I think so - again, the issue here is that while Unified promises
> “eventually”, real programs usually need some certainty, and for that, an
> explicit RMA synchronization is required.
>
> Bill
>
> On Jan 19, 2015, at 8:42 AM, Jim Dinan <james.dinan at gmail.com> wrote:
>
> Bumping this thread for progress.  Please take a look a the two errata
> suggestions that I captured from the December meeting.  If folks feel that
> this is a good direction, I can convert the informal text below into proper
> errata proposals.
>
>  ~Jim.
>
> On Wed, Dec 17, 2014 at 6:39 PM, Jim Dinan <james.dinan at gmail.com> wrote:
>
>> Hi All,
>>
>> Reviewing my notes from the WG meeting, it appears that the following
>> errata would clarify many misunderstandings of the MPI-3 RMA spec:
>>
>> 1) Clarify the target process rank for load/store operations on shared
>> memory windows.  This is needed so that synchronization operations (e.g.
>> lock/unlock and PSCW) are well defined on shared memory windows.
>>
>> 2) Clarify that that while there is one copy of the window data in memory
>> in the unified memory model, there are still public and private views that
>> must be synchronized according to the RMA semantics.
>>
>> Is there enough support for these that they should be captured for future
>> discussion?
>>
>> Cheers,
>>  ~Jim.
>>
>
> _______________________________________________
> mpiwg-rma mailing list
> mpiwg-rma at lists.mpi-forum.org
> http://lists.mpi-forum.org/mailman/listinfo.cgi/mpiwg-rma
>
>
>
> _______________________________________________
> mpiwg-rma mailing list
> mpiwg-rma at lists.mpi-forum.org
> http://lists.mpi-forum.org/mailman/listinfo.cgi/mpiwg-rma
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.mpi-forum.org/pipermail/mpiwg-rma/attachments/20150121/128c73f2/attachment-0001.html>