[petsc-dev] Error on large problems.

Mark Adams mfadams at lbl.gov
Sat Mar 7 16:27:23 CST 2015


On Sat, Mar 7, 2015 at 3:11 PM, Barry Smith <bsmith at mcs.anl.gov> wrote:

>
>   Hmm,  my first guess is a mixup between PetscMPIInt and PetscInt arrays
> or MPIU_INT somewhere. (But compilers catch most of these)
>

I have a run with ~9K eq/core 128K cores many times but have never gotten
the 32K/core (4B eq.) run to work.  So it looks like an int overflow issue.


>
>   Another possibility is bug in the MPI for many large messages; any
> chance you can run the same thing on a very different system? Mira?
>

Not soon, but I have Chombo and PETSc built on Mira and it would not be
hard to get this code setup and try it.

This is for SCE15 so I will turn the PETSc test off unless someone has any
ideas on something to try.  I am using maint perhaps I should use master.

Mark


>
>   Barry
>
> > On Mar 7, 2015, at 1:21 PM, Mark Adams <mfadams at lbl.gov> wrote:
> >
> > I seem to be getting this error on Edison with 128K cores and ~4 Billion
> equations.  I've seen this error several time.  I've attached a recent
> output from this.  I wonder if it is an integer overflow.  This built with
> 64 bit integers, but I notice that GAMG prints out N and I see N=0 for the
> finest level.
> >
> > Mark
> > <out.131072.uniform.txt>
>
>
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