Excellent. Seems like several people have thought of this at the same
time (I was pinged about this by the IB vendors).
I know that others on the team have more experience in this area than I
do, so I personally welcome all information. I've read a few papers on
the topic (general/simplified consensus: memory and process affinity is
good), but would appreciate any pointers to more material.
After the theory, however, we need to decide on an implementation
strategy. As Rich mentioned, we can do this all via MCA parameters, or
perhaps via MPI_Info or MPI attributes. Although I'm not sure how much
of this can be set ahead of time and what needs to be done on a
per-thread basis, I'm assuming that each thread will need to make some
kind of function call (if MPI is going to handle it, then it will need
to be an MPI function call that triggers some magic under the covers).
Any advice here from the Open MP community would also be appreciated...
On Jul 18, 2005, at 11:08 AM, Edgar Gabriel wrote:
We have currently Barbara Chapman from the University of Houston as a
guest scientist here at Stuttgart. Most of you might now, that Barbara
is working on compiler design and OpenMP issues. This afternoon she
dropped in my office and asked me, whether the Open MPI group has
thought/discussed processor affinity issues up to now (which we just
did
:-) ).
Anyway, I just wanted to point out, that various people from the OpenMP
community have been working/are still working on this issue, and that
it
might be interesting to exchange information and maybe coordinate the
approaches. I cc'ed Barbara therefore also on this email...
--
{+} Jeff Squyres
{+} The Open MPI Project
{+} http://www.open-mpi.org/
