On Sat, Jan 7, 2017 at 6:47 PM, Manuel Valera <[email protected]> wrote:
> Awesome Matt and Jed, > > The GCR is used because the matrix is not invertible and because this was > the algorithm that the previous library used, > > The Preconditioned im aiming to use is multigrid, i thought i configured > the hypre-boomerAmg solver for this, but i agree in that it doesn't show in > the log anywhere, how can i be sure is being used ? i sent -ksp_view log > before in this thread > Yes, that says you are using Block Jacobi/ILU. Try running with -pc_type gamg which is algebraic multigrid. That will give good iteration counts, but not be as efficient as geometric MG. Once that works, you can switch over to geometric. > I had a problem with the matrix block sizes so i couldn't make the petsc > native multigrid solver to work, > Please send the error. > This is a nonhidrostatic pressure solver, it is an elliptic problem so > multigrid is a must, > Yes, MG is the way to go. Matt > Regards, > > Manuel > > On Sat, Jan 7, 2017 at 4:34 PM, Jed Brown <[email protected]> wrote: > >> Manuel Valera <[email protected]> writes: >> >> > I was able to find the bug, it was the outer loop bound in the same >> fashion >> > than before, my -log_view is this : >> [...] >> > ########################################################## >> > # # >> > # WARNING!!! # >> > # # >> > # This code was compiled with a debugging option, # >> > # To get timing results run ./configure # >> > # using --with-debugging=no, the performance will # >> > # be generally two or three times faster. # >> > # # >> > ########################################################## >> >> The above isn't a joke. >> >> > VecMDot 525 1.0 1.7089e+00 1.7 1.48e+09 1.0 0.0e+00 0.0e+00 >> > 1.0e+03 7 17 0 0 6 7 17 0 0 6 1735 >> > >> > VecMAXPY 1050 1.0 2.3646e+00 1.1 2.97e+09 1.0 0.0e+00 0.0e+00 >> > 0.0e+00 11 34 0 0 0 11 34 0 0 0 2508 >> >> You are spending about a third of the solve time doing vector work. >> What is your reason for using GCR? >> >> > KSPSolve 5 1.0 1.2218e+01 1.0 8.66e+09 1.0 1.1e+03 2.0e+04 >> > 1.9e+04 59100 99 43 99 59100 99 43 99 1418 >> > >> > PCSetUp 3 1.0 1.7993e+00 1.0 1.27e+07 1.0 0.0e+00 0.0e+00 >> > 1.0e+01 8 0 0 0 0 8 0 0 0 0 14 >> > >> > PCSetUpOnBlocks 5 1.0 1.9013e-01 1.7 1.27e+07 1.0 0.0e+00 0.0e+00 >> > 0.0e+00 1 0 0 0 0 1 0 0 0 0 134 >> > >> > PCApply 546 1.0 3.8320e+00 1.1 1.77e+09 1.0 0.0e+00 0.0e+00 >> > 1.0e+00 18 20 0 0 0 18 20 0 0 0 925 >> >> To make a big improvement, you'll need a better preconditioner. What >> kind of problem is this? >> > > -- 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
