[mpiwg-hybridpm] Hybrid telecon fiasco

Jim Dinan james.dinan at gmail.com
Mon Apr 7 12:09:10 CDT 2014

Little did you know, you'd still be holding these meetings 4 years later.

Meeting notes:

In attendance: Dan and Jim

Open items for endpoints:

** Interface for freeing endpoints communicators:

Current, we use MPI_Comm_free to free endpoints communicators, and we
extend the MPI_Comm_free semantics to allows one thread to call this
routine for each endpoint.  If we didn't have this extension to Comm_free,
you can create endpoints, e.g. in MPI_THREAD_SERIALIZED mode, but you can't
free them.  The Forum dislikes this new semantic and as suggested that we
remove it.

Dan suggested a third approach where we leave the Comm_free semantic
unchanged and add a new function, MPI_Comm_free_endpoints(MPI_Comm
comm_handles[], int my_num_ep), that has symmetry with
Comm_create_endpoints.  An endpoints communicator can be freed with either
Comm_free or Comm_free_endpoints.  They differ in their concurrency

** MPI_ALIASED result from comm_compare:

We need to define aliased, on page 237 for comm_compare.  We may also need
to define it for group_compare.  Here's suggested text for comm_compare
(changes highlighted):

MPI_IDENT results if and only if comm1 and comm2 are handles for the same
object (same rank, identical groups, and same contexts). MPI_ALIASED results
if comm1 and comm2 are handles for different ranks in the same communicator
(different ranks, identical groups, and same contexts). MPI_CONGRUENT results
if the underlying groups are identical in constituents and rank order;
these communicators differ only by context. MPI_SIMILAR results if the
group members of both communicators are the same but the rank order differs.
MPI_UNEQUAL results otherwise.

On Mon, Apr 7, 2014 at 12:24 PM, Balaji, Pavan <balaji at anl.gov> wrote:

> Folks,
> We were supposed to have a hybrid telecon today.  Unfortunately, when I
> created my calendar invite 4 years ago, I decided that March 2014 was a
> great end date for the telecons and didn't have it show up on my calendar.
> Jim and Dan met.  Jim will email out notes.
> Sorry about that.
>   -- Pavan
> _______________________________________________
> mpiwg-hybridpm mailing list
> mpiwg-hybridpm at lists.mpi-forum.org
> http://lists.mpi-forum.org/mailman/listinfo.cgi/mpiwg-hybridpm
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