[petsc-users] Enquiry regarding log summary results

[Barry Smith]

  There will always be the "initial" stage for anything that happens before the first stage push(). Not much should be happening in it however.

    Barry


On Oct 2, 2012, at 4:55 PM, TAY wee-beng <zonexo at gmail.com> wrote:

> On 27/9/2012 1:44 PM, Matthew Knepley wrote:
>> On Thu, Sep 27, 2012 at 3:49 AM, TAY wee-beng <zonexo at gmail.com> wrote:
>> Hi,
>> 
>> I'm doing a log summary for my 3d cfd code. I have some questions:
>> 
>> 1. if I'm solving 3 linear equations using ksp, is the result given in the log summary the total of the 3 linear eqns' performance? How can I get the performance for each individual eqn?
>> 
>> Use logging stages: http://www.mcs.anl.gov/petsc/petsc-dev/docs/manualpages/Profiling/PetscLogStagePush.html
> 
> I retried using :
> 
> PetscLogStage  stage
> 
> call PetscInitialize(PETSC_NULL_CHARACTER,ierr)
> 
> call PetscLogStageRegister("momentum",stage,ierr)
>     
> call PetscLogStagePush(stage,ierr)
> 
> ... 1st stage - solving momentum eqn - run 1st logging    
> 
> call PetscLogStagePop(ierr)
> 
> call PetscLogStageRegister("poisson",stage,ierr)
>     
> call PetscLogStagePush(stage,ierr)
> 
> ... 2nd stage - solve poisson eqn - run 2nd logging
> 
> call PetscLogStagePop(ierr)
> 
> call PetscFinalize(ierr)
> 
> I have attached the log_summary results. Turns out that there are 3 stages - 0,1 (momentum),2 (poisson). Shouldn't I be getting 2 stages instead? How can I correct it? Or it doesn't matter?
>>  
>> 2. If I run my code for 10 time steps, does the log summary gives the total or avg performance/ratio?
>> 
>> Total.
>>  
>> 3. Besides PETSc, I'm also using HYPRE's native geometric MG (Struct) to solve my Cartesian's grid CFD poisson eqn. Is there any way I can use PETSc's log summary to get HYPRE's performance? If I use boomerAMG thru PETSc, can I get its performance?
>> 
>> If you mean flops, only if you count them yourself and tell PETSc using http://www.mcs.anl.gov/petsc/petsc-dev/docs/manualpages/Profiling/PetscLogFlops.html
>> 
>> This is the disadvantage of using packages that do not properly monitor things :)
>> 
>>     Matt
>>  
>> 
>> -- 
>> Yours sincerely,
>> 
>> TAY wee-beng
>> 
>> 
>> 
>> 
>> -- 
>> What most experimenters take for granted before they begin their experiments is infinitely more interesting than any results to which their experiments lead.
>> -- Norbert Wiener
> 
> <log_summary.txt>