[petsc-dev] errors with cuda + mumps

[Zhang, Junchao]

On Wed, Mar 13, 2019 at 11:28 AM Matthew Knepley <knepley at gmail.com<mailto:knepley at gmail.com>> wrote:
On Wed, Mar 13, 2019 at 12:16 PM Zhang, Junchao via petsc-dev <petsc-dev at mcs.anl.gov<mailto:petsc-dev at mcs.anl.gov>> wrote:
I met some errors with cuda + mumps.

It does not look like CUDA is being used in these runs. Is it? If not, do you mean MUMPS goes crazy if we even compiler something with CUDA?
No, the tests do not use GPU.  I need further investigation.


  Thanks,

     Matt

It was tested with
make -f gmakefile test search='snes_tutorials-ex69_q2p1fetidp_deluxe snes_tutorials-ex62_fetidp_2d_quad snes_tutorials-ex69_q2p1fetidp_deluxe_adaptive ksp_ksp_tutorials-ex52f_mumps'
I can reproduce it with petsc master.  The first line of petsc nightly (http://ftp.mcs.anl.gov/pub/petsc/nightlylogs/archive/2019/03/12/master.html) shows another error. But I guess they have the same root: PETSc gives random wrong results in some cases. For example, I ran ksp_ksp_tutorials-ex52f_mumps twice and saw

$ mpirun -n 3 ./ex52f
Mumps row pivot threshhold =    1.00E-06
Mumps determinant=(   9.01E-01   0.00E+00)*2^ 99
Norm of error  1.5554E-06 iterations     1

$ mpirun -n 3 ./ex52f
Mumps row pivot threshhold =    1.00E-06
Mumps determinant=(   9.01E-01   0.00E+00)*2^ 99
Norm of error  1.6356E-06 iterations     1

The correct output has "Norm of error < 1.e-12,iterations     1".  Currently, I do know the reason.

--Junchao Zhang


--
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/>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.mcs.anl.gov/pipermail/petsc-dev/attachments/20190313/26236b33/attachment.html>