[Mpi3-rma] New version of RMA chapter posted

[Barrett, Brian W]

On 4/16/11 12:50 PM, "William Gropp" <wgropp at illinois.edu> wrote:

>I found a few changes from MPI 2.2 that I missed the first time.  I've
>also change the handling of the few ticket o items to use consistent
>colors (green is delete, red is inserted).  A few of the items from
>Jim's notes were updated; someone needs to look at the others and at
>least propose specific updates.

All -

I have Jeff's changes and some of my own that we need to get inserted.
Since I don't have access to the tex file, do you want me to send the long
list?  I'd really rather just modify the tex directly, as it will take
less time, even if someone else wants to continue managing commits to the
svn.

As for the examples, it's pretty obvious that after the store in Example
11.7, we'd need an MPI_FOO() call to act as a memory barrier.  The other
way to handle the issue in the current definition would be to be in a lock
shared epoch and call win_sync, in which case the example is valid for
both the unified and separate models.

Less clear is what to do with example 11.9.  Similar to the store in
Example 11.7, some synchronization is necessary for the load in Process B.
 One could insert a MPI_FOO call before the load and give FOO both load
and store synchronization, of course.  One could also be in a lock shared
epoch and call win sync before the load, in which case the example is
valid for both the unified and separate models.

I'm actually leaning towards the second option; it doesn't require us
delving into language dependent semantics, it synchronizes the local and
remote views of the window, which is a semantic that we know how to
provide and is fairly language independent.

Brian

-- 
  Brian W. Barrett
  Dept. 1423: Scalable System Software
  Sandia National Laboratories