[petsc-users] Error of MatMPIAIJSetPreallocation

[Qin Lu]

Hi Matthew,
Thanks for your response! Does CHKERRQ work for FORTRAN-90?
I linked my program with debug version of Petsc lib and got more error messages as attached below. I only used 8 processes, but the message said a big number, as well as a huge memory size, which must be wrong since the problem size is not very big. Does this mean the non-zero sizes passed to the subroutine are not correct?
Thanks,Qin
==== error messages =====
[2]PETSC ERROR: --------------------- Error Message --------------------------------------------------------------

[2]PETSC ERROR: Out of memory. This could be due to allocating

[2]PETSC ERROR: too large an object or bleeding by not properly

[2]PETSC ERROR: destroying unneeded objects.

[2]PETSC ERROR: Memory allocated 0 Memory used by process 2049617920

[2]PETSC ERROR: Try running with -malloc_dump or -malloc_view for info.

[2]PETSC ERROR: Memory requested 18446744073458206720

[2]PETSC ERROR: See https://www.mcs.anl.gov/petsc/documentation/faq.html for trouble shooting.

[2]PETSC ERROR: Petsc Release Version 3.12.5, Mar, 29, 2020


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On Thursday, January 14, 2021, 2:30 PM, Matthew Knepley <knepley at gmail.com> wrote:

On Thu, Jan 14, 2021 at 11:58 AM Qin Lu via petsc-users <petsc-users at mcs.anl.gov> wrote:

Hello,
My program got error 55 from calling MatMPIAIJSetPreallocation with Petsc version 3.12.5, what does this error mean? Interestingly, the same program using an older version 3.4.2 works fine. I did make necessary interface change in my program when I upgraded to 3.12.5. 

1) You should always call CHKERRQ(ierr) after a Petsc call. Then you will get the full error message and stack to send in.
2) Your error code is here:
  https://gitlab.com/petsc/petsc/-/blob/v3.12.5/include/petscerror.h#L17
3) It is a memory error. You asked for more memory than your machine could allocate.
  Thanks,
     Matt 
Thanks in advance for your help. 
Regards,Qin


-- 
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/



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