This looks like it might be noisy data. I'd make sure you run each size on the same set of nodes and you might run each job twice (A,B,A,B) in a job script.
On Wed, Apr 10, 2019 at 8:12 AM Myriam Peyrounette via petsc-users < petsc-users@mcs.anl.gov> wrote: > Here is the time weak scaling from the same study. The 3.10.2 version > seems to be much more stable with regard to the execution time. But not > necessarily faster for "large scale" simulations (problem size = 1e8). > > I didn't use -mat_freeintermediatedatastructures. I tested it this morning > and the solver diverges when using this option (KSPReason -3). > > Myriam > > Le 04/09/19 à 17:23, Zhang, Hong a écrit : > > Myriam, > Do you have 'execution time scalability' plot? Did you use > '-mat_freeintermediatedatastructures' for PETSc 3.10.2? > We made several computing optimizations on MatPtAP(), which might trade > memory for speed. It would be helpful to see a complete comparison. > Hong > > On Tue, Apr 9, 2019 at 7:43 AM Myriam Peyrounette via petsc-users < > petsc-users@mcs.anl.gov> wrote: > >> Hi, >> >> in my first mail, I provided a memory scaling concerning the PETSc >> example #42. You'll find attached the main files used (one for PETSc >> 3.6.4, one for PETSc 3.10.2), and the corresponding memory scaling. >> >> In the main files, I modified the solver/preconditioner, so that it >> corresponds to my problem. You'll find the modifications by searching >> the keyword "TopBridge". In particular, I use GAMG. >> >> Note that the example is about solving Stokes equation, so using GAMG >> may not be adapted. However, the memory gap appears and that's the >> point. No matter if the results are correct. >> >> Are these scripts useful for you? Let me know. >> >> Thanks, >> >> Myriam >> >> >> Le 04/04/19 à 00:09, Jed Brown a écrit : >> > Myriam Peyrounette via petsc-users <petsc-users@mcs.anl.gov> writes: >> > >> >> Hi all, >> >> >> >> for your information, you'll find attached the comparison of the weak >> >> memory scalings when using : >> >> >> >> - PETSc 3.6.4 (reference) >> >> - PETSc 3.10.4 without specific options >> >> - PETSc 3.10.4 with the three scalability options you mentionned >> >> >> >> Using the scalability options does improve the memory scaling. However, >> >> the 3.6 version still has a better one... >> > Yes, this still looks significant. Is this an effect we can still >> > reproduce with a PETSc example and/or using a memory profiler (such as >> > massif or gperftools)? I think it's important for us to narrow down >> > what causes this difference (looks like almost 2x on your 1e8 problem >> > size) so we can fix. >> >> -- >> Myriam Peyrounette >> CNRS/IDRIS - HLST >> -- >> >> > -- > Myriam Peyrounette > CNRS/IDRIS - HLST > -- > >
