[petsc-users] Memory problem

Rongliang Chen rongliang.chan at gmail.com
Wed Oct 5 17:56:53 CDT 2011


Hello Everyone,

I am testing a non-linear problem using the  snessolve(). The degree of
freedoms of my test case is about 1 Million, which means the Jacobian matrix
in the snessolve() is an 1 million by 1 million matrix and it should be a
sparse matrix.
And my question is that in the "-log_summary" output file I find a strange
massage: "Matrix    39             39  18446744074642894848     0". Does
this message mean that the matrix's memory usage is 1.8x10^20? I have no
idea why an  one million by one million matrix use so much memory. Is this
possible? The output of the "-log_summary" followed. Thanks.

Best,
Rongliang

-------------------------------------------------------------------------------------------------------------------------
Starting to load grid...
 Nodes on moving boundary: coarse 199, fine 799, Gridratio 0.250000.
Setupping Interpolation matrix......
Interpolation matrix done......Time spent: 0.405431
finished.
Grid has 32000 elements, 1096658 degrees of freedom.
Coarse grid has 2000 elements, 70170 degrees of freedom.
  [0] has 35380 degrees of freedom (matrix), 35380 degrees of freedom
(including shared points).
  [0] coarse grid has 2194 degrees of freedom (matrix), 2194 degrees of
freedom (including shared points).
  [31] has 32466 degrees of freedom (matrix), 34428 degrees of freedom
(including shared points).
  [31] coarse grid has 2250 degrees of freedom (matrix), 2826 degrees of
freedom (including shared points).
Time spend on the load grid and create matrix etc.: 3.577862.
Solving fixed mesh (steady-state problem)
Solving coarse problem......
  0 SNES norm 3.1224989992e+01, 0 KSP its last norm 0.0000000000e+00.
  1 SNES norm 1.3987219837e+00, 25 KSP its last norm 2.4915963656e-01.
  2 SNES norm 5.1898321541e-01, 59 KSP its last norm 1.3451744761e-02.
  3 SNES norm 4.0024228221e-02, 56 KSP its last norm 4.9036146089e-03.
  4 SNES norm 6.7641787439e-04, 59 KSP its last norm 3.6925683196e-04.
Coarse solver done......
Initial value of object function (Energy dissipation) (Coarse):
38.9341108701
  0 SNES norm 7.4575110699e+00, 0 KSP its last norm 0.0000000000e+00.
  1 SNES norm 6.4497565921e-02, 51 KSP its last norm 7.4277453141e-03.
  2 SNES norm 9.2093642958e-04, 90 KSP its last norm 5.4331380112e-05.
  3 SNES norm 8.1283574549e-07, 103 KSP its last norm 7.5974191049e-07.
Initial value of object function (Energy dissipation) (Fine): 42.5134271399
Solution time of 17.180358 sec.
Fixed mesh (Steady-state) solver done.
Total number of nonlinear iterations = 3
Total number of linear iterations = 244
Average number of linear iterations = 81.333336
Time computing: 17.180358 sec, Time outputting: 0.000000 sec.
Time spent in coarse nonlinear solve: 0.793436 sec, 0.046183 fraction of
total compute time.
Solving Shape Optimization problem (steady-state problem)
Solving coarse problem......
  0 SNES norm 4.1963166116e+01, 0 KSP its last norm 0.0000000000e+00.
  1 SNES norm 3.2749386875e+01, 132 KSP its last norm 4.0966334477e-01.
  2 SNES norm 2.2874504408e+01, 130 KSP its last norm 3.2526355310e-01.
  3 SNES norm 1.4327187891e+01, 132 KSP its last norm 2.1213029400e-01.
  4 SNES norm 1.7283643754e+00, 81 KSP its last norm 1.4233338128e-01.
  5 SNES norm 3.6703566918e-01, 133 KSP its last norm 1.6069896349e-02.
  6 SNES norm 3.6554528686e-03, 77 KSP its last norm 3.5379167356e-03.
Coarse solver done......
Optimized value of object function (Energy dissipation) (Coarse):
29.9743062939
The reduction of the energy dissipation (Coarse): 23.012737%
The optimized curve (Coarse):
 a = (4.500000, -0.042893, -0.002030, 0.043721, -0.018798, 0.001824)
Solving  moving mesh equation......
 KSP norm 2.3040219081e-07, KSP its. 741. Time spent 8.481956
Moving mesh solver done.
  0 SNES norm 4.7843968670e+02, 0 KSP its last norm 0.0000000000e+00.
  1 SNES norm 1.0148854085e+02, 49 KSP its last norm 4.7373180511e-01.
  2 SNES norm 1.8312214030e+00, 46 KSP its last norm 1.0133332840e-01.
  3 SNES norm 3.3101970861e-03, 212 KSP its last norm 1.7753271069e-03.
  4 SNES norm 4.9552614008e-06, 249 KSP its last norm 3.2293284103e-06.
Optimized value of object function (Energy dissipation) (Fine):
33.2754372645
Solution time of 4053.227456 sec.
Number of unknowns = 1096658
Parameters: kinematic viscosity = 0.01
            inlet velocity: u = 5,  v = 0
Total number of nonlinear iterations = 4
Total number of linear iterations = 556
Average number of linear iterations = 139.000000
Time computing: 4053.227456 sec, Time outputting: 0.000001 sec.
Time spent in coarse nonlinear solve: 24.239526 sec, 0.005980 fraction of
total compute time.
The optimized curve (fine):
 a = (4.500000, -0.046468, -0.001963, 0.045736, -0.019141, 0.001789)
The reduction of the energy dissipation (Fine): 21.729582%
Time spend on fixed mesh solving: 17.296872
Time spend on shape opt. solving: 4053.250126
Latex command line:
  np    Newton   GMRES   Time(Total)    Time(Coarse)   Ratio
 32 &   4   &   139.00   &   4053.23  &    24.24   &  0.6\%

Running finished on: Wed Oct  5 11:32:04 2011
Total running time: 4070.644329
************************************************************************************************************************
***             WIDEN YOUR WINDOW TO 120 CHARACTERS.  Use 'enscript -r
-fCourier9' to print this document            ***
************************************************************************************************************************

---------------------------------------------- PETSc Performance Summary:
----------------------------------------------

./joab on a Janus-nod named node1751 with 32 processors, by ronglian Wed
Oct  5 11:32:04 2011
Using Petsc Release Version 3.2.0, Patch 1, Mon Sep 12 16:01:51 CDT 2011

                         Max       Max/Min        Avg      Total
Time (sec):           4.074e+03      1.00000   4.074e+03
Objects:              1.011e+03      1.00000   1.011e+03
Flops:                2.255e+11      2.27275   1.471e+11  4.706e+12
Flops/sec:            5.535e+07      2.27275   3.609e+07  1.155e+09
MPI Messages:         1.103e+05      5.41392   3.665e+04  1.173e+06
MPI Message Lengths:  1.326e+09      2.60531   2.416e+04  2.833e+10
MPI Reductions:       5.969e+03      1.00000

Flop counting convention: 1 flop = 1 real number operation of type
(multiply/divide/add/subtract)
                            e.g., VecAXPY() for real vectors of length N -->
2N flops
                            and VecAXPY() for complex vectors of length N
--> 8N flops

Summary of Stages:   ----- Time ------  ----- Flops -----  --- Messages ---
-- Message Lengths --  -- Reductions --
                        Avg     %Total     Avg     %Total   counts
%Total     Avg         %Total   counts   %Total
 0:      Main Stage: 4.0743e+03 100.0%  4.7058e+12 100.0%  1.173e+06 100.0%
2.416e+04      100.0%  5.968e+03 100.0%

------------------------------------------------------------------------------------------------------------------------
See the 'Profiling' chapter of the users' manual for details on interpreting
output.
Phase summary info:
   Count: number of times phase was executed
   Time and Flops: Max - maximum over all processors
                   Ratio - ratio of maximum to minimum over all processors
   Mess: number of messages sent
   Avg. len: average message length
   Reduct: number of global reductions
   Global: entire computation
   Stage: stages of a computation. Set stages with PetscLogStagePush() and
PetscLogStagePop().
      %T - percent time in this phase         %F - percent flops in this
phase
      %M - percent messages in this phase     %L - percent message lengths
in this phase
      %R - percent reductions in this phase
   Total Mflop/s: 10e-6 * (sum of flops over all processors)/(max time over
all processors)
------------------------------------------------------------------------------------------------------------------------
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

MatMult             2493 1.0 1.2225e+0218.4 4.37e+09 1.1 3.9e+05 2.2e+03
0.0e+00  2  3 33  3  0   2  3 33  3  0  1084
MatMultTranspose       6 1.0 3.3590e-02 2.2 7.38e+06 1.1 8.0e+02 1.5e+03
0.0e+00  0  0  0  0  0   0  0  0  0  0  6727
MatSolve            2467 1.0 1.1270e+02 1.7 5.95e+10 1.7 0.0e+00 0.0e+00
0.0e+00  2 33  0  0  0   2 33  0  0  0 13775
MatLUFactorSym         4 1.0 3.4774e+00 3.1 0.00e+00 0.0 0.0e+00 0.0e+00
1.2e+01  0  0  0  0  0   0  0  0  0  0     0
MatLUFactorNum        18 1.0 2.0832e+02 3.7 1.55e+11 3.2 0.0e+00 0.0e+00
0.0e+00  2 56  0  0  0   2 56  0  0  0 12746
MatILUFactorSym        1 1.0 8.3280e-03 2.2 0.00e+00 0.0 0.0e+00 0.0e+00
1.0e+00  0  0  0  0  0   0  0  0  0  0     0
MatAssemblyBegin     103 1.0 7.6879e+0215.4 0.00e+00 0.0 1.6e+04 6.2e+04
1.7e+02  7  0  1  4  3   7  0  1  4  3     0
MatAssemblyEnd       103 1.0 3.7818e+01 1.0 0.00e+00 0.0 3.0e+03 5.3e+02
1.6e+02  1  0  0  0  3   1  0  0  0  3     0
MatGetRowIJ            5 1.0 4.8716e-02 2.6 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
MatGetSubMatrice      18 1.0 4.3095e+00 2.5 0.00e+00 0.0 1.6e+04 3.5e+05
7.4e+01  0  0  1 20  1   0  0  1 20  1     0
MatGetOrdering         5 1.0 1.4656e+00 2.8 0.00e+00 0.0 0.0e+00 0.0e+00
1.4e+01  0  0  0  0  0   0  0  0  0  0     0
MatPartitioning        1 1.0 1.4356e-01 1.0 0.00e+00 0.0 0.0e+00 0.0e+00
1.0e+00  0  0  0  0  0   0  0  0  0  0     0
MatZeroEntries        42 1.0 2.0939e-01 1.1 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
VecDot                17 1.0 1.2719e-02 6.8 5.47e+05 1.1 0.0e+00 0.0e+00
1.7e+01  0  0  0  0  0   0  0  0  0  0  1317
VecMDot             2425 1.0 1.7196e+01 2.2 5.82e+09 1.1 0.0e+00 0.0e+00
2.4e+03  0  4  0  0 41   0  4  0  0 41 10353
VecNorm             2503 1.0 2.7923e+00 3.4 1.18e+08 1.1 0.0e+00 0.0e+00
2.5e+03  0  0  0  0 42   0  0  0  0 42  1293
VecScale            2467 1.0 7.3112e-02 1.7 5.84e+07 1.1 0.0e+00 0.0e+00
0.0e+00  0  0  0  0  0   0  0  0  0  0 24453
VecCopy              153 1.0 1.1636e-02 1.8 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              5031 1.0 6.0423e-01 2.2 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              137 1.0 1.1462e-02 1.5 6.33e+06 1.1 0.0e+00 0.0e+00
0.0e+00  0  0  0  0  0   0  0  0  0  0 16902
VecWAXPY              19 1.0 1.7784e-03 1.4 2.83e+05 1.1 0.0e+00 0.0e+00
0.0e+00  0  0  0  0  0   0  0  0  0  0  4869
VecMAXPY            2467 1.0 8.5820e+00 1.3 5.93e+09 1.1 0.0e+00 0.0e+00
0.0e+00  0  4  0  0  0   0  4  0  0  0 21153
VecAssemblyBegin      69 1.0 1.0341e+0018.2 0.00e+00 0.0 4.9e+03 5.4e+02
2.1e+02  0  0  0  0  3   0  0  0  0  3     0
VecAssemblyEnd        69 1.0 2.4939e-04 2.8 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
VecScatterBegin     7491 1.0 1.3734e+00 1.7 0.00e+00 0.0 1.1e+06 1.9e+04
0.0e+00  0  0 96 76  0   0  0 96 76  0     0
VecScatterEnd       7491 1.0 2.0055e+02 8.7 0.00e+00 0.0 0.0e+00 0.0e+00
0.0e+00  3  0  0  0  0   3  0  0  0  0     0
VecReduceArith         8 1.0 1.4977e-03 2.0 3.05e+05 1.1 0.0e+00 0.0e+00
0.0e+00  0  0  0  0  0   0  0  0  0  0  6232
VecReduceComm          4 1.0 8.9908e-0412.2 0.00e+00 0.0 0.0e+00 0.0e+00
4.0e+00  0  0  0  0  0   0  0  0  0  0     0
VecNormalize        2467 1.0 2.8067e+00 3.4 1.75e+08 1.1 0.0e+00 0.0e+00
2.4e+03  0  0  0  0 41   0  0  0  0 41  1905
SNESSolve              4 1.0 4.0619e+03 1.0 2.23e+11 2.3 9.4e+05 2.3e+04
4.1e+03100 98 80 77 68 100 98 80 77 68  1136
SNESLineSearch        17 1.0 1.1423e+01 1.0 5.23e+07 1.1 1.8e+04 1.7e+04
3.3e+02  0  0  2  1  6   0  0  2  1  6   140
SNESFunctionEval      23 1.0 2.9742e+01 1.0 2.60e+07 1.1 1.9e+04 1.9e+04
3.5e+02  1  0  2  1  6   1  0  2  1  6    27
SNESJacobianEval      17 1.0 3.6786e+03 1.0 0.00e+00 0.0 9.8e+03 6.4e+04
1.4e+02 90  0  1  2  2  90  0  1  2  2     0
KSPGMRESOrthog      2425 1.0 2.5150e+01 1.6 1.16e+10 1.1 0.0e+00 0.0e+00
2.4e+03  0  8  0  0 41   0  8  0  0 41 14157
KSPSetup              36 1.0 2.5388e-02 1.1 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              18 1.0 3.6141e+02 1.0 2.25e+11 2.3 1.1e+06 2.4e+04
5.0e+03  9100 97 96 84   9100 97 96 84 13015
PCSetUp               36 1.0 2.1635e+02 3.6 1.55e+11 3.2 1.8e+04 3.2e+05
1.5e+02  3 56  2 20  3   3 56  2 20  3 12274
PCSetUpOnBlocks       18 1.0 2.1293e+02 3.7 1.55e+11 3.2 0.0e+00 0.0e+00
2.7e+01  2 56  0  0  0   2 56  0  0  0 12471
PCApply             2467 1.0 2.5616e+02 2.5 5.95e+10 1.7 7.3e+05 2.8e+04
0.0e+00  4 33 62 73  0   4 33 62 73  0  6060
------------------------------------------------------------------------------------------------------------------------

Memory usage is given in bytes:

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

--- Event Stage 0: Main Stage

              Matrix    39             39  18446744074642894848     0
 Matrix Partitioning     1              1          640     0
           Index Set   184            184      2589512     0
   IS L to G Mapping     2              2       301720     0
              Vector   729            729    133662888     0
      Vector Scatter    29             29        30508     0
   Application Order     2              2      9335968     0
                SNES     4              4         5088     0
       Krylov Solver    10             10     32264320     0
      Preconditioner    10             10         9088     0
              Viewer     1              0            0     0
========================================================================================================================
Average time to get PetscTime(): 1.19209e-07
Average time for MPI_Barrier(): 1.20163e-05
Average time for zero size MPI_Send(): 2.49594e-06
......................................
-----------------------------------------
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