Re: MPI debugging workflows
On 2018-08-30 14:18, Alastair McKinstry wrote:
On 30/08/2018 09:39, Drew Parsons wrote:
If you want a break from the openmpi angst then go ahead and drop
mpich 3.3b3 into unstable. It won't make the overall MPI situation
any worse... :)
Drew
Ok, I've pushed 3.3b3 to unstable.
Great!
For me there are two concerns:
(1) The current setup (openmpi default) shakes out issues in openmpi3
that should be fixed. It would be good to get that done.
That's fair. If we're going to "drop" openmpi, it's a good policy to
leave it in as stable a state as possible.
(2) moving to mpich as default is a transition and should be pushed
before the deadline - say setting 30 Sept?
This is probably a good point to confer with the Release Team, so I'm
cc:ing them.
Release Team: we have nearly completed the openmpi3 transition. But
there is a broader question of switching mpi-defaults to mpich instead
of openmpi. mpich is reported to be more stable than openmpi and is
recommended by several upstream authors of the HPC software libraries.
We have some consensus that switching to mpich is probably a good idea,
it's just a question of timing at this point.
Does an MPI / mpich transition overlap with other transitions planned
for Buster - say hwloc, hdf5 ?
hdf5 already builds against both openmpi and mpich, so it should not be
a particular problem. It has had more build failures on the minor arches
(with the new hdf5 version in experimental), but there's no reason to
blame mpich for that.
I don't know about hwloc, but the builds in experimental look clean.
Drew
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