[petsc-dev] Adding support memkind allocators in PETSc

[Barry Smith]

> On Jun 3, 2015, at 9:28 PM, Jed Brown <jed at jedbrown.org> wrote:
> 
> Barry Smith <bsmith at mcs.anl.gov> writes:
>>  Richard has access to the hardware
> 
> Is this true?  Or he will have hardware "soon"?
> 
>>  and is not going to "lie to us" that "oh it helps so much" because
>>  he knows that you will test it yourself and see that he is lying. 
> 
> I'm not at all worried about him lying, but I'm concerned about being
> able to sample across a sufficiently broad range of apps/configurations.
> Maybe he can run some PETSc examples and PFLOTRAN, which is a good
> start, but may not be running in the appropriately memory-constrained
> circumstances of a package with particles like pTatin, for example.  We
> care not just about the highs but also about the confusing corners that
> users will undoubtedly encounter.

  Even if it "helps" in only 30 percent of applications that is still a good thing (and a great thing politically). Then it becomes an issue of education and proper profiling tools to tell people for their apps that it won't work; so the other 70% is not "confused".

  Note that Marc Snir today told me that it is perfectly fine if the "largest computing systems", i.e. the LCFs can only provide useful performance for a small subset of all possible applications.

  Barry