[petsc-users] EPSSolve in a loop

[Dharmendar Reddy]

On Sat, May 4, 2013 at 9:54 AM, Jed Brown <jedbrown at mcs.anl.gov> wrote:

> Dharmendar Reddy <dharmareddy84 at gmail.com> writes:
>
> >>    You are right, The time per solve increases in both case, see the
> > attached plot.
> >
> >   I have attached the stage wise log_summary .
>
> Thanks.
>
>       ##########################################################
>       #                                                        #
>       #                          WARNING!!!                    #
>       #                                                        #
>       #   This code was compiled with a debugging option,      #
>       #   To get timing results run ./configure                #
>       #   using --with-debugging=no, the performance will      #
>       #   be generally two or three times faster.              #
>       #                                                        #
>       ##########################################################
>
>
> Here are some relevant events:
>
>
> --- Event Stage 1: Solve Step : 1
>
> IPOrthogonalize       90 1.0 7.7698e-02 1.0 3.04e+06 1.0 0.0e+00 0.0e+00
> 5.4e+02  0  1  0  0  0  18 67  0  0 32    39
> IPInnerProduct       896 1.0 5.1215e-02 1.0 1.60e+06 1.0 0.0e+00 0.0e+00
> 0.0e+00  0  0  0  0  0  12 35  0  0  0    31
> VecMAXPBY            179 1.0 2.0418e-02 1.0 1.44e+06 1.0 0.0e+00 0.0e+00
> 0.0e+00  0  0  0  0  0   5 32  0  0  0    71
> VecScale              89 1.0 9.6772e-03 1.0 7.92e+03 1.0 0.0e+00 0.0e+00
> 0.0e+00  0  0  0  0  0   2  0  0  0  0     1
> VecReduceArith       448 1.0 3.6906e-02 1.0 1.48e+06 1.0 0.0e+00 0.0e+00
> 0.0e+00  0  0  0  0  0   9 32  0  0  0    40
>
>
> --- Event Stage 111: Solve Step : 111
>
> IPOrthogonalize       90 1.0 1.5872e+01 1.0 3.04e+06 1.0 0.0e+00 0.0e+00
> 5.4e+02  1  1  0  0  0  83 67  0  0 32     0
> IPInnerProduct       896 1.0 9.5349e+00 1.0 1.60e+06 1.0 0.0e+00 0.0e+00
> 0.0e+00  1  0  0  0  0  50 35  0  0  0     0
> VecMAXPBY            179 1.0 6.3249e+00 1.0 1.44e+06 1.0 0.0e+00 0.0e+00
> 0.0e+00  1  0  0  0  0  33 32  0  0  0     0
> VecScale              89 1.0 3.1402e+00 1.0 7.92e+03 1.0 0.0e+00 0.0e+00
> 0.0e+00  0  0  0  0  0  16  0  0  0  0     0
> VecReduceArith       448 1.0 9.5169e+00 1.0 1.48e+06 1.0 0.0e+00 0.0e+00
> 0.0e+00  1  0  0  0  0  49 32  0  0  0     0
>
>
> VecScale is simple and does exactly the same amount of work in both
> cases, so I think the problem is in memory management.  It doesn't look
> like you are using enough memory to be swapping and I don't think there
> are any CHKMEMQ statements in here.  You could try running with '-malloc
> 0', and/or in optimized mode.
>

There is no CHKMEMQ statements. I will try running the optimized modes.
Aren't the different eps objects independent ? All the objects are created
only once. Every time i call solve, all i do is EPSSetOperators and
EPSSolve.
The code is designed to provide a eigensolver to the user, without worrying
about the slepc and petsc objects inside, if i have to resue the eps
objects for all solvers then i may have to share the eps between different
instances of eigenSolver, i am not sure how easily i can do that.

I am running the code on dual 8-core Xeon X5 with 32 GB memory. I hardly
use 1 to 2 % of memory. What do you mean by memory management problem ?


> It looks like you create one EPS per loop iteration, but don't destroy
> any of them until the end.  If you don't need all the EPS at once, you
> should either reuse one throughout the loop or destroy the new one each
> step after using it.
>

          I need to reuse the eps objects, There is an outer loop

   do jc=1,numSolve

    computeOperators (A1,B1,A2,B2,A3,B3)

   do ic=1,111
     eigenSolver(ic)%solve
  end do

  ComputeOtherQuantities based on eigenvectors
end do

-- 
-----------------------------------------------------
Dharmendar Reddy Palle
Graduate Student
Microelectronics Research center,
University of Texas at Austin,
10100 Burnet Road, Bldg. 160
MER 2.608F, TX 78758-4445
e-mail: dharmareddy84 at gmail.com
Phone: +1-512-350-9082
United States of America.
Homepage: https://webspace.utexas.edu/~dpr342
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