[petsc-dev] GAMG error with MKL

[Jed Brown]

Mark Adams <mfadams at lbl.gov> writes:

> On Mon, Jul 9, 2018 at 7:19 PM Jeff Hammond <jeff.science at gmail.com> wrote:
>
>>
>>
>> On Mon, Jul 9, 2018 at 7:38 AM, Mark Adams <mfadams at lbl.gov> wrote:
>>
>>> I agree with Matt's comment and let me add (somewhat redundantly)
>>>
>>>
>>>> This isn't how you'd write MPI, is it?  No, you'd figure out how to
>>>> decompose your data properly to exploit locality and then implement an
>>>> algorithm that minimizes communication and synchronization.  Do that with
>>>> OpenMP.
>>>>
>>>
>>> I have never seen a DOE app that does this correct, get you data model
>>> figured out first, then implement.
>>>
>>
>> Chris Kerr's weather code (GFDL Hiram) has a single OpenMP parallel
>> region.  He was at the last NERSC workshop I attended.  You should talk to
>> him.
>>
>>
> He is the last person I need to talk to :) but I wish my fusion colleagues
> had walked down the road and talked with him 10 years ago.

I don't know if Chris has ever lived there.  And he's great, but GFDL is
an application, not a library.

Jeff, let us know when MKL can be called collectively from within an omp
parallel region.