Varun, I believe Jose is correct. You may verify it by running your code with option '-log_view', then check the number of calls to MatLUFactorSym.
I guess I can add a flag in PCSetUp() to check if user has already called MatLUFactorSymbolic() and wants to skip it. Normally, users simply allocate sufficient memory in the symbolic factorization. Why do you want to check it? Hong ________________________________ From: Jose E. Roman <[email protected]> Sent: Sunday, January 16, 2022 5:11 AM To: Varun Hiremath <[email protected]> Cc: Zhang, Hong <[email protected]>; Peder Jørgensgaard Olesen via petsc-users <[email protected]> Subject: Re: [petsc-users] PETSc MUMPS interface Hong may give a better answer, but if you look at PCSetUp_LU() https://petsc.org/main/src/ksp/pc/impls/factor/lu/lu.c.html#PCSetUp_LU you will see that MatLUFactorSymbolic() is called unconditionally during the first PCSetUp(). Currently there is no way to check if the user has already called MatLUFactorSymbolic(). Jose > El 16 ene 2022, a las 10:40, Varun Hiremath <[email protected]> > escribió: > > 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 <[email protected]> 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 <[email protected]> on behalf of Junchao > Zhang <[email protected]> > Sent: Wednesday, January 12, 2022 9:03 AM > To: Varun Hiremath <[email protected]> > Cc: Peder Jørgensgaard Olesen via petsc-users <[email protected]> > Subject: Re: [petsc-users] PETSc MUMPS interface > > Calling PCSetUp() before KSPSetUp()? > > --Junchao Zhang > > > On Wed, Jan 12, 2022 at 3:00 AM Varun Hiremath <[email protected]> > 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>
