[petsc-dev] print statements in fortran interface functions

[Matthew Knepley]

On different OSes, the buffering for printf is different. Do you mean that
the program ends correctly and prints nothing, or
do you mean that you execute a print but nothing immediately outputs to the
screen. We do not explicitly flush, so it could
be that this weird OS is buffering in a way you do not expect.

  Matt

On Mon, Mar 16, 2020 at 11:02 PM Mark Adams <mfadams at lbl.gov> wrote:

> Thanks, I have verified that PetscPrint with an installed libs works as
> expected on my Mac (on ex73f90t).
> I'll keep looking on Cori.
> ThanksMark
>
> On Mon, Mar 16, 2020 at 10:37 PM Jacob Faibussowitsch <jacob.fai at gmail.com>
> wrote:
>
>> May be an issue printing to STDOUT, HPC sometimes redirect STDOUT to some
>> other log files. Maybe try redirecting your PetscInfo() or PetscPrintf()
>> output to a file. For PetscInfo its just a filename after the info flag:
>> ./yourCode -info somefile . As for the PetscPrintf you will have to change
>> those calls in your src to PetscFPrintf().
>>
>> Best regards,
>>
>> Jacob Faibussowitsch
>> (Jacob Fai - booss - oh - vitch)
>> Cell: (312) 694-3391
>>
>> On Mar 16, 2020, at 9:26 PM, Mark Adams <mfadams at lbl.gov> wrote:
>>
>>
>>
>> On Mon, Mar 16, 2020 at 9:50 PM Jacob Faibussowitsch <jacob.fai at gmail.com>
>> wrote:
>>
>>> Hello Mark,
>>>
>>> If you are using PetscInfo to print, PetscInfo requires that you pass
>>> “-info” as a command line flag in order to print anything. Sounds simple
>>> enough to miss, did you run your code with it? i.e. ./yourCode -info?
>>>
>>
>> Yea, I added -info.
>>
>>
>>>
>>> For what its worth, PetscPrintf on PETSC_COMM_WORLD will always print
>>> but only from proc 0. PetscSynchronizedPrintf prints from all in order.
>>> Might be more useful for debugging than PetscInfo!
>>>
>>
>> Yea, I started with PetscPrintf. Started with WORLD then tried SELF.
>> Still no output but I can step through the code and see the print
>> statements, but nothing.
>>
>> This is on Cori/Haswell. I have now used printf on my Mac and it works. I
>> did not do an install on my Mac, but I would not think that would matter...
>> I should test that I suppose.
>>
>>
>>>
>>> Best regards,
>>>
>>> Jacob Faibussowitsch
>>> (Jacob Fai - booss - oh - vitch)
>>> Cell: (312) 694-3391
>>>
>>> On Mar 16, 2020, at 7:54 PM, Mark Adams <mfadams at lbl.gov> wrote:
>>>
>>> I am trying to debug an application code that works with v3.7 but fails
>>> with master. The code works for "normal" solvers but for a solver that uses
>>> FieldSplit it fails. It looks like vectors are not getting created from
>>> MatCreateVecs with a matrix that is a MatNest (I can't run the code).
>>>
>>> I have put print statements in the interface files to try to see what is
>>> going on but the print statements seem to disappear somehow. (I added the
>>> same print statements in my installation of v3.7 to see what is different)
>>> I was using PetscPrint and then found and example of a Fortran PetscInfo
>>> and switched to that. I stepped through the code with DDT and see the print
>>> statements but nothing goes to the output. I did this DDT stuff with
>>> ex73f90t, which has a MatCreateNest.
>>>
>>> I am completely baffled. Does anyone have any ideas?
>>>
>>> Thanks,
>>> Mark
>>>
>>>
>>>
>>

-- 
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

https://www.cse.buffalo.edu/~knepley/ <http://www.cse.buffalo.edu/~knepley/>
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