[petsc-dev] PetscLogView vs. -log_summary

Barry Smith bsmith at mcs.anl.gov
Thu Jun 21 17:16:17 CDT 2012


On Jun 21, 2012, at 3:40 PM, Matthew Knepley wrote:

> On Thu, Jun 21, 2012 at 2:08 PM, Blaise Bourdin <bourdin at lsu.edu> wrote:
> 
> On Jun 21, 2012, at 2:55 PM, Matthew Knepley wrote:
> 
>> On Thu, Jun 21, 2012 at 1:11 PM, Blaise Bourdin <bourdin at math.lsu.edu> wrote:
>> Hi,
>> 
>> PetscLogView does not display the same amount of information as running with -log_summary. In the "summary of stages" section, the former contains only information on the main stage while the later contains much more.
>> 
>> Add the following block at the end of src/snes/examples/tutorials/ex1.c, for instance, to see what I mean
>>  PetscViewer viewer;
>>  ierr = PetscViewerASCIIOpen(PETSC_COMM_WORLD,"ex1-log.py",&viewer);CHKERRQ(ierr);
>>  ierr = PetscLogViewPython(viewer);CHKERRQ(ierr);
>>  ierr = PetscViewerDestroy(&viewer);CHKERRQ(ierr);
>>  ierr = PetscViewerASCIIOpen(PETSC_COMM_WORLD,"ex1-log.txt",&viewer);CHKERRQ(ierr);
>>  ierr = PetscLogView(viewer);CHKERRQ(ierr);
>>  ierr = PetscViewerDestroy(&viewer);CHKERRQ(ierr);
>>  ierr = PetscLogPrintDetailed(PETSC_COMM_WORLD,"ex1-logdetailed.txt");CHKERRQ(ierr);
>> 
>> Is this a bug or a feature? Is there a way to get the same output as -log_summary in a file, without printing it to stdout?
>> 
>> -log_summary just calls PetscLogView(). I am not sure how there could be a problem. I will run it. However, can you
>> just use
>> 
>>   -log_summary <filename>
> 
> That works, yes. Is the issue that stages / events need to be activated a priori, which is not possible when PetscLogView is only called at the end of the program?
> 
> Crap.

    Matt,  why is this "Crap"   its completely reasonable that if you want to have logging from program control that you have to turn it on programatically?



> If you do not provide -log_summary, you need PetscLogBegin() at the beginning.
> 
>    Matt
>  
> The caveat is that I am assuming that when using log_summary, the log is written as part of PetscFinalize, so that if a job is killed by the sceduler or the user, there is no way to get an idea of the performances. I like to print the log every so often.
> 
> Blaise
> 
> -- 
> Department of Mathematics and Center for Computation & Technology
> Louisiana State University, Baton Rouge, LA 70803, USA
> Tel. +1 (225) 578 1612, Fax  +1 (225) 578 4276 http://www.math.lsu.edu/~bourdin
> 
> 
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> 
> -- 
> 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




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