[petsc-dev] general aggregates in ASM, from GAMG aggregates, and overlap problem

[Barry Smith]

   He's should submit a full bug report to petsc-maint at mcs.anl.gov. 

   Barry

> On Sep 16, 2016, at 2:48 PM, Mark Adams <mfadams at lbl.gov> wrote:
> 
> Garth is getting a segv when he uses -pc_gamg_asm_use_agg and an overlap of 1.
> 
> This seems like a pretty hard thing to do right and I would not be surprised if it was not done with complete generality. MatGetSubMatrix is find to get any submatrix but enlarging a remote subdomain seems very tricky.
> 
> Should I perhaps check for overlap in GAMG and give an error? Maybe it would be better to have ASM do this.  Maybe I could make ASM have a flag am-i-nested and not allow overlap if not?
> 
> Mark