[petsc-users] performance issue solving multiple linear systems of the same size with the different preconditioning methods

[Алексей Рязанов]

Thank you for your response!

I have the memory leak in both my programs. But I don't create plenty of
vectors.

My code looks like:

  ***INIT_ALL***
  PetscLogStageRegister("Iteration  :", &StageNum1);
  PetscLogStagePush(StageNum1);
  KSPSolve(dKSP, dvec_origRHS, dvec_Solution);
  PetscLogStagePop();
  ***DESTROY_ALL***


And when I comment (or delete) KSPSolve, the log_summary output is:

=====================================================
Memory usage is given in bytes:

Creations   Destructions     Memory  Descendants' Mem Object Type
Reports information only for process 0.

--- Event Stage 0: Main Stage
1              1         729472     0   Application Order
1              1         225452     0   Distributed array
8              8       1533424     0   Vec
3              3             2604     0   Vec Scatter
8              8         613852     0   Index Set
1              1         221304     0   IS L to G Mapping
3              3     16603440     0   Matrix
1              1               832     0   Krylov Solver
1              1               688     0   Preconditioner
1              1               448     0   PetscRandom

--- Event Stage 1: Iteration  :
=====================================================

When I run the code with KSPSolve instruction, it gives me:

=====================================================
Memory usage is given in bytes:
Creations   Destructions     Memory  Descendants' Mem Object Type
Reports information only for process 0.

--- Event Stage 0: Main Stage
1              0            0            0      Application Order
1              0            0            0      Distributed array
8             17      4963592     0      Vec
3              2         1736         0      Vec Scatter
8             12      1425932     0      Index Set
1              0            0            0      IS L to G Mapping
3              5     50158132     0      Matrix
1              2         1664         0      Krylov Solver
1              2         1440         0      Preconditioner
1              1          448          0      PetscRandom
0              1          544          0      Viewer

--- Event Stage 1: Iteration  :
355        173   64692312     0      Vec
1              0            0            0      Vec Scatter
6              2         1024         0      Index Set
2              0            0            0      Matrix
1              0            0            0      Krylov Solver
1              0            0            0      Preconditioner
2              1          544          0      Viewer
=====================================================




2011/8/25 Jed Brown <jedbrown at mcs.anl.gov>

> On Tue, Aug 23, 2011 at 02:37, Алексей Рязанов <ram at ibrae.ac.ru> wrote:
>
>> When i delete the 4-5-6 part of 2nd, 1-2-3 works great! with exact like
>> 1st results.
>> When i delete the 1-2-3 part of 2nd, 4-5-6 works great! with exact like
>> 1st results.
>> All program (1-2-3-4-5-6) works badly.
>>
>
> From the -log_summary, you have a memory leak (many more vector creations
> than destructions). Try running with -malloc_dump to debug it. Perhaps you
> are creating a vector every time one of your functions is called? You should
> also build --with-debugging=0 when looking at timing results. (You can keep
> it in PETSC_ARCH=linux-gnu-opt.)
>



-- 
Best regards,
Alexey Ryazanov
______________________________________
Nuclear Safety Institute of Russian Academy of Sciences
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