Hi Hong, Thank you, this is very helpful!
Using this method I am able to get the memory estimates before the actual solve, however, I think my code may be causing the symbolic factorization to be run twice. Attached is my code where I am using SLEPc to compute eigenvalues, and I use MUMPS for factorization. I have commented above the code that computes the memory estimates, could you please check and tell me if this would cause the symbolic factor to be computed twice (a second time inside EPSSolve?), as I am seeing a slight increase in the overall computation time? Regards, Varun On Wed, Jan 12, 2022 at 7:58 AM Zhang, Hong <hzh...@mcs.anl.gov> wrote: > PCFactorSetMatSolverType(pc,MATSOLVERMUMPS); > PCFactorSetUpMatSolverType(pc); > PCFactorGetMatrix(pc,&F); > > MatLUFactorSymbolic(F,A,...) > You must provide row and column permutations etc, > petsc/src/mat/tests/ex125.c may give you a clue on how to get these > inputs. > > Hong > > > ------------------------------ > *From:* petsc-users <petsc-users-boun...@mcs.anl.gov> on behalf of > Junchao Zhang <junchao.zh...@gmail.com> > *Sent:* Wednesday, January 12, 2022 9:03 AM > *To:* Varun Hiremath <varunhirem...@gmail.com> > *Cc:* Peder Jørgensgaard Olesen via petsc-users <petsc-users@mcs.anl.gov> > *Subject:* Re: [petsc-users] PETSc MUMPS interface > > Calling PCSetUp() before KSPSetUp()? > > --Junchao Zhang > > > On Wed, Jan 12, 2022 at 3:00 AM Varun Hiremath <varunhirem...@gmail.com> > wrote: > > Hi All, > > I want to collect MUMPS memory estimates based on the initial > symbolic factorization analysis before the actual numerical factorization > starts to check if the estimated memory requirements fit the available > memory. > > I am following the steps from > https://petsc.org/main/src/ksp/ksp/tutorials/ex52.c.html > > PCFactorSetMatSolverType(pc,MATSOLVERMUMPS); > PCFactorSetUpMatSolverType(pc); > PCFactorGetMatrix(pc,&F); > > KSPSetUp(ksp); > MatMumpsGetInfog(F,...) > > But it appears KSPSetUp calls both symbolic and numerical factorization. > So is there some other way to get these statistics before the actual > factorization starts? > > Thanks, > Varun > >
slepc_eps_mumps_test.cpp
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