[petsc-users] memory corruption when using harmonic extraction with SLEPc

[Dave May]

On Thu, 2 Aug 2018 at 21:32, Moritz Cygorek <mcygorek at uottawa.ca> wrote:

> Hi,
>
>
> I want to diagonalize a huge sparse matrix and I'm using the Kryov-Schur
> method with harmonic extraction (command line option -eps_harmonic )
> implemented in SLEPc.
>
>
> I manually distribute a sparse matrix across several CPUs and everything
> works fine when:
>
> - I do _not_ use harmonic extraction
>
> - I use harmonic extraction on only a single CPU
>
>
> If I try do use harmonic extraction on multiple CPUs, I get a memory
> corruption.
>
> I'm not quite sure where to look at, but somewhere in the output, I find:
>
>
>
> [1]PETSC ERROR: PetscMallocValidate: error detected at
> PetscSignalHandlerDefault() line 145 in
> /home/applications/sources/libraries/petsc-3.9.3/src/sys/error/signal.c
> [1]PETSC ERROR: Memory [id=0(9072)] at address 0x145bcd0 is corrupted
> (probably write past end of array)
> [1]PETSC ERROR: Memory originally allocated in DSAllocateWork_Private()
> line 74 in
> /home/applications/sources/libraries/slepc-3.9.2/src/sys/classes/ds/interface/dspriv.c
>
>
> Now, I have the feeling that this might be a bug in SLEPc because, if I
> had messed up the matrix initialization and distribution, I should also get
> a memory corruption when I don't use harmonic extraction, right?
>

Not necessarily


> Any suggestions what might be going on?
>

Run your code through valgrind and make sure that your application code is
clean. See here

http://www.mcs.anl.gov/petsc/documentation/faq.html#valgrind

If errors are detected in your application code, fix them and see if the
slepc errors go away. If your code is valgrind clean, send through the
relevant chunk of the valgrind report indicating exactly where the error is
occurring

Thanks,
  Dave



> Regards,
>
> Moritz
>
>
>
>
>
>
>
>
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