[Mpi3-rma] RMA proposal 1 update

Rajeev Thakur thakur at mcs.anl.gov
Tue May 25 21:38:04 CDT 2010


> > 5:12-14 - Update: "If the window was created with MPI_Win_create,
the
> > user is responsible for freeing the window memory after MPI_Win_free
> > returns. If the window was created with MPI_Win_allocate,
MPI_Win_free
> > will free the window memory that was allocated in MPI_Win_allocate."
> I think we should not prescribe what the user has to do. He might as
> well choose to never free the memory and this is outside the scope of
> the MPI standard. I don't see a problem with the current phrasing.

I wanted to make it clear who is freer rather than saying "can be
freed", "will be freed" (by whom?). How about this:

"If the window was created with MPI_Win_create, the user may free the
window memory after MPI_Win_free returns. If the window was created with
MPI_Win_allocate, MPI_Win_free will free the window memory that was
allocated in MPI_Win_allocate."

Or you can say the user may choose to, if he so wishes, free the window
memory... :-)


> > 27:38 - Flushall is not useful unless there is a corresponding
> > lockall/unlockall.
> I believe this needs to be discussed (I don't think this statement is
> true).

MPI_Win_lock allows RMA to a single target rank. How can you do a
flushall to multiple ranks? Nesting of multiple MPI_Win_lock calls is
not allowed in the current version of your proposal, is it?

I thought you were going to add Lockall/Unlockall, but just forgot to
:-).
 
Rajeev




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