[Mpi3-rma] RMA chapter for quick review

Barrett, Brian W bwbarre at sandia.gov
Fri Mar 11 11:26:56 CST 2011

On 3/10/11 6:54 PM, "Rajeev Thakur" <thakur at mcs.anl.gov> wrote:

>An updated version of the RMA chapter is attached to this mail and on the
>wiki. We would like to make it available to the Forum by tomorrow
>afternoon in order to meet the two-week window for the first reading at
>the March meeting. If you have a chance, please take a look at it and let
>us know your comments before tomorrow afternoon.
>In particular:
> - We fixed some issues with the rules on pg 47 and 48. Please take a
>look at those rules in their entirety.
> - pg 3, ln 43, has been updated to specify that default value for the
>accumulate_ops key is same_op_no_op.

Page and line numbers are from the marked-up copy, not the clean copy.

Pg 1, ln 45/46 & pg 2, ln 1&2: The discussion of communication operations
being delayed for the separate model and immediate for the unified model
is a bit confusing.  When the implementation *starts* the communication is
the same for both models, depending on the synchronization calls.  The
only difference between the two models is when the private and public
copies on the target must be synchronized.  As I read the standard, an
implantation is free to start a put immediately upon calling MPI_PUT in
the separate model and also free to start a put during MPI_UNLOCK in the
unified model.

Pg 2, ln 3&4: I think the last sentence might read a bit better as "A
large number of synchronization calls, which support both models, are
provided to support difference synchronization styles."  But I'm open to
better wording :).

Pg 26, ln 47: There's a word missing in the final sentence of the
paragraph.  Perhaps: "The stronger semantics of the RMA unified model
allow the user to omit some synchronization calls and potentially improve

Pg 50, ln 2: "synchronization in Process B", the p in process should be
Pg 50, ln 28: p in Process A should be lowercase
Pg 50, ln 29: p in Process B should be lowercase (twice)
Pg 51, ln 15: p in Process A should be lowercase
Pg 51, ln 25: Should be "local store by process B before the lock" (insert
word process)
Pg 52, ln 21: insert word "process" at "allow B to read", "stored by A"
Pg 52, ln 24: reword sentence, should be "in the private copy of process A"
Pg 52, ln 24: "the update to Y", not "the update on Y"
Pg 52, ln 27: insert work process in "the value stored by A"
Pg 52, ln 32: insert "process" at "private copy of X at process B"
Pg 53, ln 13: can remove the comment, someone fixed the latex foo
Pg 53, ln 42: The citation for the algorithm is missing (Torsten?)

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

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