[petsc-users] question about small matrices

[Matthew Knepley]

On Wed, Sep 25, 2019 at 1:27 AM Povolotskyi, Mykhailo via petsc-users <
petsc-users at mcs.anl.gov> wrote:

> Dear Petsc developers,
>
> in my application I have to solve millions of linear and non-linear
> systems with small matrices (2x2, 3x3,..., 10x10).
>
> I consider them as dense, and use SNES with KSP method PREONLY, and LU
> preconditioner.
>
> I found that when KSPSolve is called only 25% of time is spend in
> lapack, the rest is PETSc overhead.
>
> I know how to call lapack directly to solve a linear system.
>
> Question: is it possible to call lapack directly in the SNES solver to
> avoid the KSPSolve overhead?
>

Question: Do you solve a bunch of them simultaneously?

  Thanks,

     Matt


> Thank you,
>
> Michael.
>
>

-- 
What most experimenters take for granted before they begin their
experiments is infinitely more interesting than any results to which their
experiments lead.
-- Norbert Wiener

https://www.cse.buffalo.edu/~knepley/ <http://www.cse.buffalo.edu/~knepley/>
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