[Mpi3-rma] [EXTERNAL] Re: MPI-3 UNIFIED model clarification

[Pavan Balaji]

Sorry, wrong rule.  Here's the right one:

"A put or accumulate must not access a target window once a load/store 
update or a
put or accumulate update to another (overlapping) target window has 
started on a
location in the target window, until the update becomes visible in the 
public copy of
the window. Conversely, a store to process memory to a location in a 
window must
not start once a put or accumulate update to that target window has 
started, until
the put or accumulate update becomes visible in process memory. In both 
cases, the
restriction applies to operations even if they access disjoint locations 
in the window."

Read it as follows (comma added):

"A put or accumulate must not access a target window once a load/store 
update, or a
put or accumulate update to another (overlapping) target window has 
started on a
location in the target window, until the update becomes visible in the 
public copy of
the window."

  -- Pavan


On 08/04/2013 07:27 PM, Pavan Balaji wrote:
>
> On 08/04/2013 07:02 PM, Jed Brown wrote:
>> I guess I'm missing something.  Why can't P1 read that other part of its
>> own memory in the SEPARATE model?  I'm assuming that P0 executed
>> something like
>>
>>    MPI_Win_lock(MPI_LOCK_SHARED,rank=1,win)
>>    MPI_Put(target_rank=1,win)
>>    MPI_Win_unlock(rank=1,win)
>
> This is not allowed in the SEPARATE model.  Page 455 lines 22-25.
>
> "A location in a window must not be accessed with load/store operations
> once an
> update to that location has started, until the update becomes visible in
> the private
> window copy in process memory."
>
>   -- Pavan
>

-- 
Pavan Balaji
http://www.mcs.anl.gov/~balaji