[petsc-users] mat option producing error for stash

[Satish Balay]

On Thu, 11 Aug 2016, Norihiro Watanabe wrote:

> Hi,
> 
> I would like to check if my program assembles a matrix without
> generating stash. To help checking it, I wonder if there is a mat
> option producing errors if entries destined for other processors are
> added/set. I mean something like MAT_NEW_NONZERO_LOCATION_ERR for
> stashing.

http://www.mcs.anl.gov/petsc/petsc-current/docs/manualpages/Mat/MatSetOption.html

MAT_NO_OFF_PROC_ENTRIES 	- you know each process will only set values for its own rows, will generate an error if any process sets values for another process. This avoids all reductions in the MatAssembly routines and thus improves performance for very large process counts. 

You can also run with -info - and it should print the size of stack thats used..

Satish