<div dir="ltr"><div class="gmail_extra"><div class="gmail_quote">On Mon, Sep 19, 2016 at 11:04 PM, Hong <span dir="ltr"><<a href="mailto:hzhang@mcs.anl.gov" target="_blank">hzhang@mcs.anl.gov</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div dir="ltr"><div class="gmail_extra"><div class="gmail_quote">David :</div><div class="gmail_quote">I did following:</div><div class="gmail_quote"><div class="gmail_quote">  </div><div class="gmail_quote">        PC  pc;</div><div class="gmail_quote">        Mat F;</div><div class="gmail_quote">        ierr = KSPGetPC(ksp,&pc);CHKERRQ(<wbr>ierr);</div><div class="gmail_quote">        ierr = PCReset(pc);CHKERRQ(ierr);</div><div class="gmail_quote">        ierr = KSPSetOperators(ksp,A,A);<wbr>CHKERRQ(ierr);</div><div class="gmail_quote">        ierr = PCSetType(pc,PCCHOLESKY);<wbr>CHKERRQ(ierr);</div><div class="gmail_quote">        </div><div class="gmail_quote">        ierr = PCFactorSetMatSolverPackage(<wbr>pc,MATSOLVERMUMPS);CHKERRQ(<wbr>ierr);</div><div class="gmail_quote">        ierr = PCFactorSetUpMatSolverPackage(<wbr>pc);CHKERRQ(ierr); </div><div class="gmail_quote">        ierr = PCFactorGetMatrix(pc,&F);<wbr>CHKERRQ(ierr);</div><div class="gmail_quote">        ierr = MatMumpsSetIcntl(F,14,30);<wbr>CHKERRQ(ierr);</div><div class="gmail_quote"><br></div><div class="gmail_quote">        ierr = KSPSolve(ksp,b,x);CHKERRQ(<wbr>ierr);</div><div class="gmail_quote"><br></div><div class="gmail_quote">Then it resolves the matrix equation with ICNTL(14)=30. </div><div class="gmail_quote">Attached is modified petsc/src/ksp/ksp/<wbr>examples/tutorials/ex10.c.</div><div class="gmail_quote">Using in with your matrix.dat, I get</div><div class="gmail_quote"><br></div><div class="gmail_quote"><div class="gmail_quote">mpiexec -n 4 ./ex10 -f0 matrix.dat -rhs 0 -ksp_reason</div><div class="gmail_quote">Number of iterations =   0</div><div class="gmail_quote">KSPConvergedReason: -11</div><div class="gmail_quote"> Reset PC with ICNTL(14)=30 ...</div><div class="gmail_quote">KSPConvergedReason: 2</div></div></div></div></div></blockquote><div><br></div><div>Hong,</div><div><br></div><div>Thanks very much for your test code. I get the same output as you when I run "mpiexec -n 4 ./ex10 -f0 matrix.dat -rhs 0 -ksp_reason".</div><div><br></div><div>However, I used KSPPREONLY in my original test code, and if I add KSPSetType(ksp,KSPPREONLY) in your modified exc10.c after the line KSPCreate(PETSC_COMM_WORLD,&ksp) then I get the following output:</div><div><br></div><div><div>mpiexec -np 4 ./mumps_test-opt -f0 matrix.dat -rhs 0 -ksp_reason</div><div>Number of iterations =   0</div><div>KSPConvergedReason: -11</div><div> Reset PC with ICNTL(14)=30 ...</div><div>KSPConvergedReason: -11</div></div><div><br></div><div>So it seems like the icntl data is not being updated when we use PREONLY. Do you know how to fix this?</div><div><br></div><div>Thanks,<br>David</div><div><br></div><div><br></div></div></div></div>