Thanks for the tips, Barry. I didn't specify --with-debugging=0 during the configuration, I think this is the problem. I'll recompile petsc accordingly to check on this.
Longmin On Thu, Mar 24, 2011 at 1:30 PM, Barry Smith <bsmith at mcs.anl.gov> wrote: > > On Mar 24, 2011, at 5:26 AM, Longmin RAN wrote: > >> Hello everyone, >> >> >> I use superlu inside petsc to solve linear systems with symmetrical >> matrix. The solving time is at least twice longer than using superlu >> directly. > > ? How much of that time is in other parts of the code, not the actual superlu > solver? Run the PETSc version with -log_summary; the times given in the lines > MatFactorSymbolic, MatFactorNumerical, MatSolve (or some similar names) are > the amount of time in Superlu. Compare those times to the superlu standalone > solution time. > > ? ?Did you ./configure PETSc with the option --with-debugging=0? > > ? Barry > > > >> Since I'm new with Petsc, I didn't fine-tune much the petsc >> solver, as I had done when using superlu directly. For example, in >> superlu there are options like diagonal pivot >> threshold(superlu_options_t.DiagPivotThresh), symmetric mode >> (superlu_options_t.SymmetricMode), and column >> permutation(superlu_options_t.ColPerm). Could anybody inform me about >> the corresponding options in petsc? Thanks in advance. >> >> BTW, I tried the following options: >> ? ? ? MatSetOption(A, MAT_SYMMETRIC, PETSC_TRUE); >> ? ? ? MatSetOption(A, MAT_SYMMETRY_ETERNAL, PETSC_TRUE); >> But it seems that these options weren't enough to reduce the solving >> time sufficiently. >> >> >> Best regards, >> >> - Longmin Ran > >
