thanks jed. I can't seem to find a stored profile. I'd have to recreate one. But i'm thinking roughly twice as many functions evaluations as jacobian evaluations.
On Thu, 24 Jun 2010, Jed Brown wrote: > On Thu, 24 Jun 2010 14:28:03 -0500, David Fuentes <[email protected]> wrote: >> On 6/24/10, Jed Brown <[email protected]> wrote: >>> On Thu, 24 Jun 2010 13:59:21 -0500 (CDT), David Fuentes >>> <[email protected]> wrote: >>>> >>>> I typically use Petsc Nonlinear Solvers in 3D and my bottle neck is >>>> typically in the assembly with Petsc SNESSolve taking ~10% of the time >>>> about ~50% in the jacobian, ~30% in the residual, and the >>>> rest is distributed. >>> >>> So the linear solves are really easy. Are you caching a lot of stuff in >>> the residual evaluation, it's not normal for it to be so much compared >>> to Jacobian assembly unless you don't use an analytic Jacobian >>> (e.g. -snes_mf_operator). >> >> Not sure, what do you typically cache ? > > I cache a local linearization at quadrature points, but that is for fast > matrix-free Jacobian application of high-order operators. It doesn't > pay off in terms of time or storage for Q1 or P1, even in 3D. But if > you had e.g. an expensive constitutive relation involving lookup tables, > and you weren't overly concerned about using the minimum possible > memory, but didn't want to do the extra work to integrate and insert the > element matrices (because there was a high chance of the line search > shortening the step), then you might cache the local linearization even > for lowest-order elements. It sounds like this is not the case. > > What does -log_summary show? Are you doing a lot more function > evaluations than Jacobian assemblies? It's surprising to me that they > would cost almost the same amount per call, perhaps there is a hot spot > somewhere in your residual evaluation. > > Jed > ------------------------------------------------------------------------------ ThinkGeek and WIRED's GeekDad team up for the Ultimate GeekDad Father's Day Giveaway. ONE MASSIVE PRIZE to the lucky parental unit. See the prize list and enter to win: http://p.sf.net/sfu/thinkgeek-promo _______________________________________________ Libmesh-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/libmesh-users
