Re: OpenMPI / MPI transition

[Alastair McKinstry <mckinstry@debian.org>]

My understanding is that MPICH has been typically the reference 
implementation, higher quality but less performant, particularly with 
the range of fabrics. Certainly I've seen mostly OpenMPI but not MPICH 
on various HPC machines. People would use either OpenMPI or a vendors 
MPI (which may be forked MPICH with added network hardware support).
> > I'd really like to hear from upstream users whether they are still 
> > encountering OpenMPI issues.
> >
> > Personally I favour splitting, using MPICH on 32-bit archs to flush 
> > out bugs, and doing so early in the dev cycle (now) so there is time 
> > to change if necessary.
>
> Thank you both for your comments.
>
> I don't think as the Release Team we have a preference one way or the 
> other. We'll let you pick the approach that you consider better. 
> Obviously the freeze is still a long ways off, so if something comes 
> up it can be changed later.
>
> Cheers,
> Emilio
Ok, as a concrete proposal: I propose to leave OpenMPI as the default 
MPI for 64-bit archs, move 32-bit archs to MPICH.

I will update mpi-defaults in one week, in order to give time for 
further responses on the matter.

I'm not sure how to write a BEN file for transition tracking when the 
SOVERSION doesn't change (as in this case with OpenMPI). Help appreciated.

regards

Alastair


--
Alastair McKinstry,
GPG: 82383CE9165B347C787081A2CBE6BB4E5D9AD3A5
e: mckinstry@debian.org, im: @alastair:mckinstry.ie