Performance degradation after upgrade to 3.0.0

[Matthew Knepley]

Can you send the matrix and rhs as PETSc binary output, and I will find out
what the difference is. It looks to me like the default ICC ordering
has changed.

  Matt

On Sun, Feb 1, 2009 at 3:01 PM, Billy Araújo <billy at dem.uminho.pt> wrote:
> Hi,
>
> Here are the files that contain all the information below. You can see that the matrices are the same, unless I am missing something here. :)
>
> (I am resending them in compressed format).
>
> Regards,
>
> Billy.
>
>
> -----Original Message-----
> From: petsc-users-bounces at mcs.anl.gov on behalf of Matthew Knepley
> Sent: Sun 2/1/2009 6:07 PM
> To: PETSc users list
> Subject: Re: Performance degradation after upgrade to 3.0.0
>
> In order to determine what is happening you first should:
>
>  1) Confirm that the solver setup is identical using -ksp_view for
> both versions
>
>  2) Determine that the matrices are identical. Output both matrices using
>      MatView() with a PetscBinaryViewer. You can diff the files, and
> you can also
>      solver both matrices using KSP ex10.
>
>  3) Look at the residuals using -ksp_monitor. If they are different, something
>      else has changed.
>
>  Matt
>
> On Sun, Feb 1, 2009 at 6:32 AM, Billy Araújo <billy at dem.uminho.pt> wrote:
>>
>> Hi,
>>
>> I have also verified that there has been a degradation of performance using
>> the new 3.0 version:
>>
>> This is my function calling PETSc:
>>
>>   KSP ksp;
>>   PC pc;
>>
>>   KSPCreate (PETSC_COMM_WORLD, &ksp);
>>
>>   KSPSetOperators (ksp, *A, *A, DIFFERENT_NONZERO_PATTERN);
>>
>>   KSPSetType (ksp, KSPFGMRES);
>>
>>   KSPGetPC (ksp, &pc);
>>
>>   PCSetType (pc, PrecondProc);
>>
>>   KSPSetInitialGuessNonzero (ksp, PETSC_TRUE);
>>
>>   KSPSetTolerances (ksp, 1E-50, maxtol, PETSC_DEFAULT, maxiter);
>>
>>   KSPSetFromOptions (ksp);
>>
>>   KSPSolve (ksp, *b, *x);
>>
>>   KSPGetIterationNumber (ksp, iter);
>>
>>   KSPGetResidualNorm (ksp, res);
>>
>>   KSPDestroy (ksp);
>>
>>
>> with previous version 2.3.3-p6:
>>
>> Number of iterations: 42 Residual: +7.073781E-13 Time: +8.615024E-03
>>
>> now:
>>
>> Number of iterations: 500 Residual: +2.746161E-05 Time: +1.026870E-01
>>
>> It is reaching maximum number of iterations. The only thing I changed was:
>>
>> MatSetOption (*A, MAT_SYMMETRIC);
>>  to
>> MatSetOption (*A, MAT_SYMMETRIC, PETSC_TRUE);
>>
>> I think I didn't change anything else.
>>
>>
>> Regards,
>>
>> Billy.
>>
>
>
>
> --
> What most experimenters take for granted before they begin their
> experiments is infinitely more interesting than any results to which
> their experiments lead.
> -- Norbert Wiener
>
>
>



-- 
What most experimenters take for granted before they begin their
experiments is infinitely more interesting than any results to which
their experiments lead.
-- Norbert Wiener