[petsc-users] Understanding log summary

Zou, Ling ling.zou at inl.gov
Fri May 19 13:12:25 CDT 2017


Barry, thanks for your comments and advise.
Lagging Jacobian evaluation certainly helped (just tested it).
However, eventually the finite differencing for Jacobian evaluation should
be replaced with some sort of approximated Jacobian evaluation subroutine.
So at this moment I don't worry too much on its cost.

Thanks again,

Ling

On Fri, May 19, 2017 at 12:02 PM, Barry Smith <bsmith at mcs.anl.gov> wrote:

>
> > On May 19, 2017, at 9:25 AM, Zou, Ling <ling.zou at inl.gov> wrote:
> >
> > Hi All,
> >
> > In terms of code performance, sometimes people would ask for info about
> total non-linear iteration numbers, total linear iteration numbers, etc. I
> suppose all these could be found in the log summary. For the attached log
> summary, can I say?
> >   total non-linear iteration number = 573
> >   total linear iteration number = 2321
>
>    Yes,
>
>     The log file is kind of funny. It spends 62% of the time in
> MatFDColorApply() which is computing the Jacobian via differencing and
> coloring, this is a lot of time. You might consider lagging the Jacobian;
> that is not recompute the Jacobian for each new linear solve. You can use
> -snes_lag_jacobian 2 or -snes_lag_jacobian 3 etc and see how this affects
> the run time.
>
>   Barry
>
>
>
>
> > MatMult MF
> >
> > Thank you.
> >
> > Ling
> >
> >
> >
> > ------------------------------------------------------------
> ------------------------------------------------------------
> > Event                Count      Time (sec)     Flops
>          --- Global ---  --- Stage ---   Total
> >                    Max Ratio  Max     Ratio   Max  Ratio  Mess   Avg len
> Reduct  %T %F %M %L %R  %T %F %M %L %R Mflop/s
> > ------------------------------------------------------------
> ------------------------------------------------------------
> >
> > --- Event Stage 0: Main Stage
> >
> > VecDot               607 1.0 1.8729e-04 1.0 1.95e+05 1.0 0.0e+00 0.0e+00
> 0.0e+00  0  0  0  0  0   0  0  0  0  0  1040
> > VecMDot             2321 1.0 1.1075e-03 1.0 2.87e+06 1.0 0.0e+00 0.0e+00
> 0.0e+00  0  5  0  0  0   0  5  0  0  0  2590
> > VecNorm             5422 1.0 1.2229e-03 1.0 1.74e+06 1.0 0.0e+00 0.0e+00
> 0.0e+00  0  3  0  0  0   0  3  0  0  0  1423
> > VecScale            5822 1.0 1.2764e-03 1.0 9.37e+05 1.0 0.0e+00 0.0e+00
> 0.0e+00  0  2  0  0  0   0  2  0  0  0   734
> > VecCopy            14334 1.0 1.8302e-03 1.0 0.00e+00 0.0 0.0e+00 0.0e+00
> 0.0e+00  0  0  0  0  0   0  0  0  0  0     0
> > VecSet              1231 1.0 3.0700e-04 1.0 0.00e+00 0.0 0.0e+00 0.0e+00
> 0.0e+00  0  0  0  0  0   0  0  0  0  0     0
> > VecAXPY            14961 1.0 3.3679e-03 1.0 4.82e+06 1.0 0.0e+00 0.0e+00
> 0.0e+00  0  9  0  0  0   0  9  0  0  0  1430
> > VecWAXPY           20842 1.0 5.5537e-03 1.0 4.00e+06 1.0 0.0e+00 0.0e+00
> 0.0e+00  0  8  0  0  0   0  8  0  0  0   721
> > VecMAXPY            2894 1.0 1.4292e-03 1.0 3.62e+06 1.0 0.0e+00 0.0e+00
> 0.0e+00  0  7  0  0  0   0  7  0  0  0  2536
> > VecSetRandom          34 1.0 1.0322e-04 1.0 0.00e+00 0.0 0.0e+00 0.0e+00
> 0.0e+00  0  0  0  0  0   0  0  0  0  0     0
> > VecReduceArith      1146 1.0 2.9907e-04 1.0 3.68e+05 1.0 0.0e+00 0.0e+00
> 0.0e+00  0  1  0  0  0   0  1  0  0  0  1230
> > VecReduceComm        573 1.0 9.2384e-05 1.0 0.00e+00 0.0 0.0e+00 0.0e+00
> 0.0e+00  0  0  0  0  0   0  0  0  0  0     0
> > VecNormalize        2894 1.0 1.9604e-03 1.0 1.39e+06 1.0 0.0e+00 0.0e+00
> 0.0e+00  0  3  0  0  0   0  3  0  0  0   712
> > SNESJacobianEval     573 1.0 2.2410e+00 1.0 5.60e+06 1.0 0.0e+00 0.0e+00
> 0.0e+00 62 11  0  0  0  62 11  0  0  0     2
> > MatMult MF          2928 1.0 5.7922e-01 1.0 2.83e+06 1.0 0.0e+00 0.0e+00
> 0.0e+00 16  5  0  0  0  16  5  0  0  0     5
> > MatMult             2928 1.0 5.7963e-01 1.0 2.83e+06 1.0 0.0e+00 0.0e+00
> 0.0e+00 16  5  0  0  0  16  5  0  0  0     5
> > MatSolve            2894 1.0 7.3171e-03 1.0 1.76e+07 1.0 0.0e+00 0.0e+00
> 0.0e+00  0 33  0  0  0   0 33  0  0  0  2405
> > MatLUFactorNum       573 1.0 1.4733e-02 1.0 1.71e+07 1.0 0.0e+00 0.0e+00
> 0.0e+00  0 32  0  0  0   0 32  0  0  0  1158
> > MatILUFactorSym        1 1.0 2.4543e-05 1.0 0.00e+00 0.0 0.0e+00 0.0e+00
> 0.0e+00  0  0  0  0  0   0  0  0  0  0     0
> > MatAssemblyBegin    1147 1.0 7.9204e-05 1.0 0.00e+00 0.0 0.0e+00 0.0e+00
> 0.0e+00  0  0  0  0  0   0  0  0  0  0     0
> > MatAssemblyEnd      1147 1.0 2.5825e-03 1.0 0.00e+00 0.0 0.0e+00 0.0e+00
> 0.0e+00  0  0  0  0  0   0  0  0  0  0     0
> > MatGetRowIJ            2 1.0 6.3280e-06 1.0 0.00e+00 0.0 0.0e+00 0.0e+00
> 0.0e+00  0  0  0  0  0   0  0  0  0  0     0
> > MatGetOrdering         1 1.0 1.5754e-05 1.0 0.00e+00 0.0 0.0e+00 0.0e+00
> 0.0e+00  0  0  0  0  0   0  0  0  0  0     0
> > MatZeroEntries       573 1.0 5.7120e-04 1.0 0.00e+00 0.0 0.0e+00 0.0e+00
> 0.0e+00  0  0  0  0  0   0  0  0  0  0     0
> > MatFDColorCreate       1 1.0 2.0541e-05 1.0 0.00e+00 0.0 0.0e+00 0.0e+00
> 0.0e+00  0  0  0  0  0   0  0  0  0  0     0
> > MatFDColorSetUp        1 1.0 1.6103e-04 1.0 0.00e+00 0.0 0.0e+00 0.0e+00
> 0.0e+00  0  0  0  0  0   0  0  0  0  0     0
> > MatFDColorApply      573 1.0 2.2386e+00 1.0 5.60e+06 1.0 0.0e+00 0.0e+00
> 0.0e+00 62 11  0  0  0  62 11  0  0  0     2
> > MatFDColorFunc     11460 1.0 2.2264e+00 1.0 1.85e+06 1.0 0.0e+00 0.0e+00
> 0.0e+00 62  3  0  0  0  62  3  0  0  0     1
> > MatColoringApply       1 1.0 3.9990e-05 1.0 0.00e+00 0.0 0.0e+00 0.0e+00
> 0.0e+00  0  0  0  0  0   0  0  0  0  0     0
> > KSPGMRESOrthog      2321 1.0 2.9685e-03 1.0 5.75e+06 1.0 0.0e+00 0.0e+00
> 0.0e+00  0 11  0  0  0   0 11  0  0  0  1935
> > KSPSetUp             573 1.0 2.3291e-04 1.0 0.00e+00 0.0 0.0e+00 0.0e+00
> 0.0e+00  0  0  0  0  0   0  0  0  0  0     0
> > KSPSolve             573 1.0 5.0164e-01 1.0 4.50e+07 1.0 0.0e+00 0.0e+00
> 0.0e+00 14 85  0  0  0  14 85  0  0  0    90
> > PCSetUp              573 1.0 1.5172e-02 1.0 1.71e+07 1.0 0.0e+00 0.0e+00
> 0.0e+00  0 32  0  0  0   0 32  0  0  0  1124
> > PCApply             2894 1.0 7.8614e-03 1.0 1.76e+07 1.0 0.0e+00 0.0e+00
> 0.0e+00  0 33  0  0  0   0 33  0  0  0  2239
> > ------------------------------------------------------------
> ------------------------------------------------------------
> >
>
>
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