Performance Log Question

[Waad Subber]

Thank you Barry for the replay. Yes I get more or less the same log when I run with the option -log_summary. Please have a look at the attached file.

Thanks

Waad

--- On Thu, 7/31/08, Barry Smith <bsmith at mcs.anl.gov> wrote:
From: Barry Smith <bsmith at mcs.anl.gov>
Subject: Re: Performance Log Question
To: petsc-users at mcs.anl.gov
Date: Thursday, July 31, 2008, 9:27 PM

   From the file, it seems you never make an nontrivial PETSc calls.  
Do you get the same
log if you just run with -log_summary?

    Barry



Event                Count      Time (sec)     Flops/ 
sec                         --- 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

------------------------------------------------------------------------------------------------------------------------



On Jul 31, 2008, at 4:33 PM, Waad Subber wrote:

> Hello,
>
> I am currently solving a 1.2 million by 1.2 million linear system  
> using PETSc 2.3.3, Patch 13 using domain decomposition (iterative  
> substructuring using a Krylov Subspace Solver). I'm using a 120 CPU  
> cluster with InfiniBand interconnect; each node has 8 cores -- 2  
> quad-core Xeon CPUs (X5365) at 3.0 GHz, each node having 32 GB of RAM.
>
> After running my code, I generate a log using the following:
>        CALL
PetscLogPrintSummary(PETSC_COMM_WORLD,"log.txt",ierr)
>
> When looking at the log output, I noticed that the peak and average  
> number of Flops seems fairly low -- in the case of one run, a peak  
> of 6.0e7 flops with an average value of 5.2e7. The exact log output  
> is:
>
>                          Max       Max/Min        Avg      Total
> Time (sec):           5.283e+01      1.02357   5.169e+01
> Objects:              2.600e+02      1.00000   2.600e+02
> Flops:                3.187e+09      1.69853   2.721e+09  3.265e+11
> Flops/sec:            6.165e+07      1.69865   5.264e+07  6.317e+09
> Memory:               6.081e+07      1.39801              6.608e+09
> MPI Messages:         1.067e+05      1.00000   1.067e+05  1.281e+07
> MPI Message Lengths:  5.205e+08      1.00081   4.875e+03  6.245e+10
> MPI Reductions:       1.898e+01      1.00000
>
> Is my interpretation correct about this being a fairly low flop  
> count? Does this mean there's an issue with my code?
>
> I am attaching my log file
>
> Thanks
>
> Waad
>
>
> <log.txt>




      
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