Running that program in a profiler shows that almost all time is spent in dealii::internal::p4est::functions<dim>::connectivity_join_faces.
Best, Daniel On Sat, Dec 20, 2025 at 7:07 PM 'Wolfgang Bangerth' via deal.II User Group <[email protected]> wrote: > > On 12/20/25 08:59, Praveen C wrote: > > > > On a 128^3, I get this timing > > > > mpirun -np 2 ./main > > > > *distributed* > > > > +---------------------------------------------+------------+------------+ > > | Total wallclock time elapsed since start | 463s | | > > | | | | > > | Section | no. calls | wall time | % of total | > > +---------------------------------+-----------+------------+------------+ > > | Add periodicity | 1 | 445s | 96% | > > | Collect faces x | 1 | 0.0425s | 0% | > > | Collect faces y | 1 | 0.0313s | 0% | > > | Collect faces z | 1 | 0.0335s | 0% | > > +---------------------------------+-----------+------------+------------+ > > Ah yes, that's clearly bad :-) Are you in a position to put timers into the > implementation of that function for the p::d::T case to figure out which part > of the algorithm is so slow? > > Short of that, I think it would be useful to try with, say, 32^3, 64^3, 128^3 > to see whether the run time grows like N^2, N^3, etc. This helps narrow down > which parts of the code one would have to look at. (E.g., if it's N^2, you > know you have to look for double loops.) > > Best > W. > > -- > The deal.II project is located at http://www.dealii.org/ > For mailing list/forum options, see > https://groups.google.com/d/forum/dealii?hl=en > --- > You received this message because you are subscribed to the Google Groups > "deal.II User Group" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > To view this discussion visit > https://groups.google.com/d/msgid/dealii/5cb216f7-2cc8-407d-a723-9296830b8e55%40colostate.edu. -- The deal.II project is located at http://www.dealii.org/ For mailing list/forum options, see https://groups.google.com/d/forum/dealii?hl=en --- You received this message because you are subscribed to the Google Groups "deal.II User Group" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion visit https://groups.google.com/d/msgid/dealii/CAOYDWb%2BFD5TBEa09eBPaVJLc3vHwx4Sx0ORAz0q0zSbpsiKTjA%40mail.gmail.com.
