[petsc-users] MPICH error in KSPSolve

[Mark F. Adams]

What problems are you having again with GAMG?  Are you problems unsymmetric?

ML has several coarsening strategies available and I think the default does aggregation locally and does not aggregate across processor subdomains.  If you have poorly shaped domains then you want to use a global coarsening method (these are not expensive).

Mark

On Jul 9, 2012, at 12:17 PM, John Mousel wrote:

> Mark,
> 
> I still haven't had much luck getting GAMG to work consistently for my Poisson problem. ML seems to work nicely on low core counts, but I have a problem where I can get long thin portions of grid on some processors instead of nice block like chunks at high core counts, which leads to a pretty tough time for ML. 
> 
> John
> 
> On Mon, Jul 9, 2012 at 10:58 AM, John Mousel <john.mousel at gmail.com> wrote:
> Getting rid of the Hypre option seemed to be the trick. 
> 
> On Mon, Jul 9, 2012 at 10:40 AM, Mark F. Adams <mark.adams at columbia.edu> wrote:
> Google PTL_NO_SPACE and you will find some NERSC presentations on how to go about fixing this.  (I have run into these problems years ago but forget the issues)
> 
> Also, I would try running with a Jacobi solver to see if that fixes the problem.  If so then you might try
> 
> -pc_type gamg
> -pc_gamg_agg_nsmooths 1
> -pc_gamg_type agg
> 
> This is a built in AMG solver so perhaps it plays nicer with resources ...
> 
> Mark
> 
> On Jul 9, 2012, at 10:57 AM, John Mousel wrote:
> 
> > I'm running on Kraken and am currently working with 4320 cores. I get the following error in KSPSolve.
> >
> > [2711]: (/ptmp/ulib/mpt/nightly/5.3/120211/mpich2/src/mpid/cray/src/adi/ptldev.c:2046) PtlMEInsert failed with error : PTL_NO_SPACE
> > MHV_exe: /ptmp/ulib/mpt/nightly/5.3/120211/mpich2/src/mpid/cray/src/adi/ptldev.c:2046: MPIDI_CRAY_ptldev_desc_pkt: Assertion `0' failed.
> > forrtl: error (76): Abort trap signal
> > Image              PC                Routine            Line        Source
> > MHV_exe            00000000014758CB  Unknown               Unknown  Unknown
> > MHV_exe            000000000182ED43  Unknown               Unknown  Unknown
> > MHV_exe            0000000001829460  Unknown               Unknown  Unknown
> > MHV_exe            00000000017EDE3E  Unknown               Unknown  Unknown
> > MHV_exe            00000000017B3FE6  Unknown               Unknown  Unknown
> > MHV_exe            00000000017B3738  Unknown               Unknown  Unknown
> > MHV_exe            00000000017B2B12  Unknown               Unknown  Unknown
> > MHV_exe            00000000017B428F  Unknown               Unknown  Unknown
> > MHV_exe            000000000177FCE1  Unknown               Unknown  Unknown
> > MHV_exe            0000000001590A43  Unknown               Unknown  Unknown
> > MHV_exe            00000000014F909B  Unknown               Unknown  Unknown
> > MHV_exe            00000000014FF53B  Unknown               Unknown  Unknown
> > MHV_exe            00000000014A4E25  Unknown               Unknown  Unknown
> > MHV_exe            0000000001487D57  Unknown               Unknown  Unknown
> > MHV_exe            000000000147F726  Unknown               Unknown  Unknown
> > MHV_exe            000000000137A8D3  Unknown               Unknown  Unknown
> > MHV_exe            0000000000E97BF2  Unknown               Unknown  Unknown
> > MHV_exe            000000000098EAF1  Unknown               Unknown  Unknown
> > MHV_exe            0000000000989C20  Unknown               Unknown  Unknown
> > MHV_exe            000000000097A9C2  Unknown               Unknown  Unknown
> > MHV_exe            000000000082FF2D  axbsolve_                 539  PetscObjectsOperations.F90
> >
> > This is somewhere in KSPSolve. Is there an MPICH environment variable that needs tweaking? I couldn't really find much on this particular error.
> > The solver is BiCGStab with Hypre as a preconditioner.
> >
> > -ksp_type bcgsl -pc_type hypre -pc_hypre_type boomeramg -ksp_monitor
> >
> > Thanks,
> >
> > John
> 
> 
> 

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