[Mpi3-rma] MPI_WIN_CREATE_DYNAMIC and target_disp

[Jim Dinan]

Hi Hubert,

Thanks for weighing in on the Fortran side of this issue.  IIUC, are you 
saying that the dynamic window displacement should be relative to the 
location of MPI_BOTTOM?  The intent of the working group was that the 
displacement should be relative to the /value/ of MPI_BOTTOM, which is 
assumed to be NULL.

Unfortunately, removing "non-negative" from the target_disp argument in 
MPI_{GET, RGET, PUT, RPUT, ACCUMULATE, ...} is a bigger change than we 
can make at this stage.

  ~Jim.

On 9/5/12 10:50 AM, Hubert Ritzdorf wrote:
> Hi,
>
> dependent on the actual discussion, I propose a change in the current
> version of MPI 3.0 draft.
> I send it to the rma list instead of mpi-comments list in order to get
> one of the discussed
> changes or this change into the MPI document:
>
> The argument target_disp in the RMA function MPI_{GET, RGET, PUT, RPUT,
> ACCUMULATE, ...}
> is qualified as non-negative integer. I think, that this cannot be
> guaranteed for the Fortran version of
> new function MPI_WIN_CREATE_DYNAMIC. The displacement is actually
> relative to
> MPI_BOTTOM which is a variable in a common block or module.
>
> The location of MPI_BOTTOM may be dependent on compiler (and possibly
> compiler options)
> and the sequence of common blocks/modules in memory.
> (Example: The memory of a window might be located in a common block,
> which is located
> in front of the common block which contains MPI_BOTTOM).
> Therefore, non-negative displacements cannot be guaranteed for windows
> created
> by MPI_WIN_CREATE_DYNAMIC in Fortran .
>
> The simple change would be to remove "non-negative". But I assume that a
> rationale would be required.
>
> Hubert
>
>
>
> _______________________________________________
> mpi3-rma mailing list
> mpi3-rma at lists.mpi-forum.org
> http://lists.mpi-forum.org/mailman/listinfo.cgi/mpi3-rma
>