[petsc-users] Slepc, shell matrix, parallel, halo exchange

[Matthew Knepley]

On Wed, Sep 21, 2022 at 7:41 AM feng wang <snailsoar at hotmail.com> wrote:

> Hello,
>
> I am using Slepc with a shell matrix. The sequential version seems working
> and now I am trying to make it run in parallel.
>
> The partition of the domain is done, I am not sure how to do the halo
> exchange in the shell matrix in Slepc. I have a parallel version of
> matrix-free GMRES in my code with Petsc. I was using VecCreateGhostBlock to
> create vector with ghost cells, and then used  VecGhostUpdateBegin/End for
> the halo exchange in the shell matrix, would this be the same for Slepc?
>

That will be enough for the MatMult(). You would also have to use a SLEPc
EPS that only needed MatMult().

  Thanks,

     Matt


> Thanks,
> Feng
>
>
>

-- 
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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