[mpiwg-hybridpm] Hybrid telecon fiasco

Jim Dinan james.dinan at gmail.com
Tue Apr 8 12:51:20 CDT 2014


Well..  I think this could tomato tomato.  And it's mixed up with OS
notions of heavyweight and lightweight processes/threads (which are outside
of the MPI spec., but define a big chunk of how MPI works in practice).
 From the perspective of the MPI standard, processes created by
MPI_Comm_create_endpoints and processes created by mpiexec should all have
MPI process semantics.  This gets tricky when we map these MPI processes to
OS processes and threads, because we typically have some assumptions and
restrictions there, but those OS constructs are technically outside of the
MPI spec.  We could have called the MPI_Comm_create_endpoints
MPI_Comm_create_processes, but that might give everyone headaches.


On Mon, Apr 7, 2014 at 6:24 PM, Jeff Squyres (jsquyres)
<jsquyres at cisco.com>wrote:

> Ok.
>
> I think we need to be very, very careful with terminology here -- there
> are *not* multiple MPI processes.  There are multiple endpoints in a single
> MPI process -- big difference (especially in terms of threaded resources in
> the same process).
>
>
>
> On Apr 7, 2014, at 6:16 PM, Jim Dinan <james.dinan at gmail.com> wrote:
>
> > That's my thinking -- we do say that each endpoint (i.e. communicator
> handle that is returned) behaves as an MPI process.
> >
> >
> > On Mon, Apr 7, 2014 at 4:25 PM, Jeff Squyres (jsquyres) <
> jsquyres at cisco.com> wrote:
> > On Apr 7, 2014, at 2:07 PM, Jim Dinan <james.dinan at gmail.com> wrote:
> >
> > > Every process in a communicator has its own set of attributes.
> >
> > "Every process in a communicator" -- does this mean each communicator
> handle that is returned?
> >
> > --
> > Jeff Squyres
> > jsquyres at cisco.com
> > For corporate legal information go to:
> http://www.cisco.com/web/about/doing_business/legal/cri/
> >
> > _______________________________________________
> > mpiwg-hybridpm mailing list
> > mpiwg-hybridpm at lists.mpi-forum.org
> > http://lists.mpi-forum.org/mailman/listinfo.cgi/mpiwg-hybridpm
> >
> > _______________________________________________
> > mpiwg-hybridpm mailing list
> > mpiwg-hybridpm at lists.mpi-forum.org
> > http://lists.mpi-forum.org/mailman/listinfo.cgi/mpiwg-hybridpm
>
>
> --
> Jeff Squyres
> jsquyres at cisco.com
> For corporate legal information go to:
> http://www.cisco.com/web/about/doing_business/legal/cri/
>
> _______________________________________________
> mpiwg-hybridpm mailing list
> mpiwg-hybridpm at lists.mpi-forum.org
> http://lists.mpi-forum.org/mailman/listinfo.cgi/mpiwg-hybridpm
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.mpi-forum.org/pipermail/mpiwg-hybridpm/attachments/20140408/adfa7077/attachment-0001.html>


More information about the mpiwg-hybridpm mailing list