On Jun 3, 2009, at 11:40 AM, Ashley Pittman wrote:
> Wasn't there a discussion about this recently on the list, OMPI binds
> during MPI_Init() so it's possible for memory to be allocated on the
> wrong quad, the discussion was about moving the binding to the orte
> process as I recall?
Yes. It's been fixed in OMPI devel trunk. I'm not sure it made it to
the v1.3 branch, but it's definitely not in a released version yet.
I *thought* that HPL did all allocation after MPI_INIT. But I could
be wrong. If so, then using numactl to bind before the MPI app starts
will likely give better results -- you're right (until we get our
fixes in such that we bind pre-main).
Regardless, if something is *changing* the affinity after MPI_INIT,
then there's little OMPI can do about that.
> >From my testing of process affinity you tend to get much more
> results with it on and much more unpredictable results with it off,
> questing that it's working properly if you are seeing a 88-93% range
> the results.
> Ashley Pittman.
> users mailing list