[petsc-dev] [petsc-users] Problem with AMG packages

[Jed Brown]

"Mark F. Adams" <mfadams at lbl.gov> writes:
> There are many parameters, including stupid things like solver
> parameters and stupider things like bugs, that can kill an iterative
> solver and we are trying to figure out what is wrong here.  You should
> be running with about 1/10 or 1/100, or even 1/1000, the number of
> processors that you are using here.  If you eventually want to run in
> this regime then that is fine but for debugging it helps to be in a
> more normal regime, because then you (or us) can start to see
> secondary things like super slow flop rates that can provide a hint of
> what is going wrong.  It is also better to start in serial so there
> are less moving parts

Pierre, can you scale the problem down to 10k or 100k degrees of freedom
and make sure that you can reproduce the qualitative convergence
behavior.

Write the matrix to a file using

  -ksp_view_mat binary:matrix-100k-jolivet

then put the file matrix-100k-jolivet and matrix-100k-jolivet.info
somewhere we can find it or anonymous ftp to ftp.mcs.anl.gov, cd
incoming, and upload the file.

This will let us experiment quickly.
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