[petsc-dev] Scalability of removing null spaces

Matthew Knepley knepley at gmail.com
Sun Jul 22 13:50:29 CDT 2012

On Sun, Jul 22, 2012 at 1:19 PM, Jed Brown <jedbrown at mcs.anl.gov> wrote:

> We recommend to people that they just call MatSetNullSpace() and solve the
> singular system. What if reductions are very expensive? Are there Krylov
> methods that accommodate a pipelined or deferred null space removal?
> Shouldn't be hard to do, but I haven't seen papers on it.

I think we have to figure out how to do this pipelined thing in a
mechanical way (not necessarily automated, but
done without thinking). You would think this had been figured out by the
architecture guys.


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
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.mcs.anl.gov/pipermail/petsc-dev/attachments/20120722/c2ac7d4d/attachment.html>

More information about the petsc-dev mailing list