<div dir="ltr"><div class="gmail_extra"><div class="gmail_quote">On Sat, Jan 7, 2017 at 6:47 PM, Manuel Valera <span dir="ltr"><<a href="mailto:mvalera@mail.sdsu.edu" target="_blank">mvalera@mail.sdsu.edu</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr">Awesome Matt and Jed, <div><br></div><div>The GCR is used because the matrix is not invertible and because this was the algorithm that the previous library used, </div><div><br></div><div>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</div></div></blockquote><div><br></div><div>Yes, that says you are using Block Jacobi/ILU. Try running with</div><div><br></div><div> -pc_type gamg</div><div><br></div><div>which is algebraic multigrid. That will give good iteration counts, but not be as efficient as geometric MG. Once</div><div>that works, you can switch over to geometric.</div><div> </div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr"><div>I had a problem with the matrix block sizes so i couldn't make the petsc native multigrid solver to work,</div></div></blockquote><div><br></div><div>Please send the error.</div><div> </div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr"><div>This is a nonhidrostatic pressure solver, it is an elliptic problem so multigrid is a must,</div></div></blockquote><div><br></div><div>Yes, MG is the way to go.</div><div><br></div><div> Matt</div><div> </div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr"><div>Regards,</div><div><br></div><div>Manuel </div></div><div class="gmail_extra"><br><div class="gmail_quote">On Sat, Jan 7, 2017 at 4:34 PM, Jed Brown <span dir="ltr"><<a href="mailto:jed@jedbrown.org" target="_blank">jed@jedbrown.org</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><span class=""><span>Manuel Valera <<a href="mailto:mvalera@mail.sdsu.edu" target="_blank">mvalera@mail.sdsu.edu</a>> writes:<br>
<br>
> I was able to find the bug, it was the outer loop bound in the same fashion<br>
> than before, my -log_view is this :<br>
</span></span>[...]<span class=""><br>
<span>> #############################<wbr>#############################<br>
> # #<br>
> # WARNING!!! #<br>
> # #<br>
> # This code was compiled with a debugging option, #<br>
> # To get timing results run ./configure #<br>
> # using --with-debugging=no, the performance will #<br>
> # be generally two or three times faster. #<br>
> # #<br>
> #############################<wbr>#############################<br>
<br>
</span></span>The above isn't a joke.<span class=""><br>
<span><br>
> VecMDot 525 1.0 1.7089e+00 1.7 1.48e+09 1.0 0.0e+00 0.0e+00<br>
> 1.0e+03 7 17 0 0 6 7 17 0 0 6 1735<br>
><br>
</span></span><span class=""><span>> VecMAXPY 1050 1.0 2.3646e+00 1.1 2.97e+09 1.0 0.0e+00 0.0e+00<br>
> 0.0e+00 11 34 0 0 0 11 34 0 0 0 2508<br>
<br>
</span></span>You are spending about a third of the solve time doing vector work.<br>
What is your reason for using GCR?<span class=""><br>
<span><br>
> KSPSolve 5 1.0 1.2218e+01 1.0 8.66e+09 1.0 1.1e+03 2.0e+04<br>
> 1.9e+04 59100 99 43 99 59100 99 43 99 1418<br>
><br>
> PCSetUp 3 1.0 1.7993e+00 1.0 1.27e+07 1.0 0.0e+00 0.0e+00<br>
> 1.0e+01 8 0 0 0 0 8 0 0 0 0 14<br>
><br>
> PCSetUpOnBlocks 5 1.0 1.9013e-01 1.7 1.27e+07 1.0 0.0e+00 0.0e+00<br>
> 0.0e+00 1 0 0 0 0 1 0 0 0 0 134<br>
><br>
> PCApply 546 1.0 3.8320e+00 1.1 1.77e+09 1.0 0.0e+00 0.0e+00<br>
> 1.0e+00 18 20 0 0 0 18 20 0 0 0 925<br>
<br>
</span></span>To make a big improvement, you'll need a better preconditioner. What<br>
kind of problem is this?<br>
</blockquote></div><br></div>
</blockquote></div><br><br clear="all"><div><br></div>-- <br><div class="gmail_signature" data-smartmail="gmail_signature">What most experimenters take for granted before they begin their experiments is infinitely more interesting than any results to which their experiments lead.<br>-- Norbert Wiener</div>
</div></div>