[petsc-users] Regarding changes in the 3.14 release

[Sajid Ali]

Hi PETSc-developers,

I have a few questions regarding changes to PETSc between version 3.13.5
and current master. I’m trying to run an application that worked with no
issues with version 3.13.5 but isn’t working with the current master.

[1] To assemble a matrix in this application I loop over all rows and have
multiple calls to MatSetValuesStencil with INSERT_VALUES as the addv
argument for all except one call which has ADD_VALUES. Final assembly is
called after this loop. With PETSc-3.13.5 this ran with no errors but with
PETSc-master I get :

Object is in wrong state
[0]PETSC ERROR: Cannot mix add values and insert values

This is fixed by having a flush assembly in between two stages where the
first stage has two loops with INSERT_VALUES and the second stage has a
loop with ADD_VALUES.

Did this change result from a bugfix or are users now expected to no longer
mix add and insert values within the same loop ?

[2] To prevent re-building the preconditioner at all TSSteps, I had the
command line argument -snes_lag_preconditioner -1. This did the job in
3.13.5 but with the current master I get the following error :

Cannot set the lag to -1 from the command line since the
preconditioner must be built as least once, perhaps you mean -2

I can however run the application without this option. If this is a
breaking change, what is the new option to prevent re-building the
preconditioner ?

[3] Finally, I’m used the latest development version of MPICH for building
both 3.13.5 and petsc-master and I get these warnings at exit :

[WARNING] yaksa: 2 leaked handles
.... (repeated N number of times where N is number of mpi ranks)

Can this be safely neglected ?

Let me know if sharing either the application code and/or logs would be
helpful and I can share either.

Thank You,
Sajid Ali | PhD Candidate
Applied Physics
Northwestern University
s-sajid-ali.github.io
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