[petsc-users] crash with PCASM in parallel

[Smith, Barry F.]

  First run under valgrind.   https://www.mcs.anl.gov/petsc/documentation/faq.html#valgrind

   If that doesn't help send the exact output from the debugger (cut and paste) and the exact version of PETSc you are using.
Also out put from -ksp_view_pre

  Barry

> On Nov 24, 2017, at 8:03 AM, Daniel Stone <daniel.stone at opengosim.com> wrote:
> 
> Hello,
> 
> I'm getting a memory exception crash every time I try to run the ASM preconditioner in parallel, can anyone help?
> 
> I'm using a debugger so I can give most of the stack:
> 
> PCApply_ASM (asm.c:line 485)
>   KSPSolve (itfunc.c:line 599)
>     KSPSetUp (itfunc.c:line 379)
>        PCSetUp (precon.c: 924)
>           PCSetUp_ILU (ilu.c:line 162)
>             MatDestroy  (matrix.c:line 1168)
>               MatDestroy_MPIBAIJ_MatGetSubMatrices (baijov.c:line 609)
> 
> 
> The problem line is then in  MatDestroy_MPIBAIJ_MatGetSubMatrices,
> in the file baijov.c, line 609:
> 
> if (!submatj->id) {
> 
> At this point submatj has no value, address 0x0, and so the attempt to access submatj->id
> causes the memory error. We can see in the lines just above 609 where submatj is supposed to
> come from, it should basically be an attribute of C->data, where C is the input matrix.
> 
> Does anyone have any ideas where to start with getting this to work? I can provide a lot more information
> from the debugger if need.
> 
> Many thanks in advance,
> 
> Daniel Stone
>