On Mon, Dec 6, 2021 at 5:59 PM Matthew Knepley <[email protected]> wrote:
> On Mon, Dec 6, 2021 at 7:54 PM Fande Kong <[email protected]> wrote: > >> Thanks, Matt, >> >> Sorry, I still have more questions on this example. How to refine mesh to >> make the problem larger? >> >> I tried the following options, and none of them worked. I might do >> something wrong. >> >> -ex56_dm_refine 9 >> >> and >> >> -dm_refine 4 >> > > The mesh handling in this example does not conform to the others, but it > appears that > > -ex56_dm_refine <k> > > should take effect at > > > https://gitlab.com/petsc/petsc/-/blob/main/src/snes/tutorials/ex56.c#L381 > > I was puzzled about this because DMSetFromOptions does not seem to trigger -ex56_dm_refine. I did a search, and could not find where we call " -ex56_dm_refine" in PETSc. I got the same result by running the following two combinations: 1) ./ex56 -log_view -snes_view -max_conv_its 3 -ex56_dm_refine 10 2) ./ex56 -log_view -snes_view -max_conv_its 3 -ex56_dm_refine 0 Thanks, Fande unless you are setting max_conv_its to 0 somehow. > > Thanks, > > Matt > > >> Thanks, >> >> Fande >> >> On Mon, Dec 6, 2021 at 5:04 PM Matthew Knepley <[email protected]> wrote: >> >>> On Mon, Dec 6, 2021 at 7:02 PM Fande Kong <[email protected]> wrote: >>> >>>> Thanks, Matt >>>> >>>> On Mon, Dec 6, 2021 at 4:47 PM Matthew Knepley <[email protected]> >>>> wrote: >>>> >>>>> On Mon, Dec 6, 2021 at 6:40 PM Fande Kong <[email protected]> wrote: >>>>> >>>>>> Dear PETSc team, >>>>>> >>>>>> I am interested in a careful evaluation of PETSc GPU performance in >>>>>> our INL cluster. >>>>>> >>>>>> Any example in PETSc that can show GPU speedup with solving a >>>>>> nonlinear equation? >>>>>> >>>>>> I talked to Junchao; he suggested that I try SNES/tutorial/ex56. I >>>>>> tried that, but I could not find any speedup using the GPU. I could >>>>>> attach >>>>>> some results of "log_view" later if we would like to see that. >>>>>> >>>>> >>>>> We should note that you will only see speedup in the solver, so that >>>>> problem has to be pretty large. I believe Mark has good results with it. >>>>> The assembly is still all on the CPU. I am working on this over break, >>>>> and hope to have a CEED version of it by the new year. >>>>> >>>> >>>> Are both function and matrix assmelies on CPU? Or just the matrix >>>> assembly? >>>> >>> >>> There is no GPU assembly right now. >>> >>> Matt >>> >>> >>>> OK, I will try to check the solver part >>>> >>>> Thanks, again >>>> >>>> Fande >>>> >>>> >>>> >>>>> >>>>> Thanks, >>>>> >>>>> Matt >>>>> >>>>> >>>>>> Appreciate any instructions/comments about running a simple PETSc GPU >>>>>> example to get a speedup. >>>>>> >>>>>> Thanks, >>>>>> >>>>>> Fande >>>>>> >>>>> >>>>> >>>>> -- >>>>> 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/> >>>>> >>>> >>> >>> -- >>> 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/> >>> >> > > -- > 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/> >
