I wonder if these jobs are scheduled in such a way so that they are not oversubscribed.
i.e number_mpi_jobs_per_node * number_of_openmp_threads_per_node <= no_of_cores_per_node Satish On Tue, 26 Jun 2018, Mark Adams wrote: > Interesting, I am seeing the same thing with ksp/ex56 (elasticity) with > 30^3 grid on each process. One process runs fine (1.5 sec) but 8 processes > with 30^3 on each process took 156 sec. > > And, PETSc's log_view is running extremely slow. I have the total time > (156) but each event is taking like a minute or more to come out. > > On Tue, Jun 26, 2018 at 10:13 AM Junchao Zhang <[email protected]> wrote: > > > > > On Tue, Jun 26, 2018 at 8:26 AM, Mark Adams <[email protected]> wrote: > > > >> > >> > >> On Tue, Jun 26, 2018 at 12:19 AM Junchao Zhang <[email protected]> > >> wrote: > >> > >>> Mark, > >>> Your email reminded me my recent experiments. My PETSc was configured > >>> --with-openmp=1. > >>> With hypre, my job ran out of time. That was on an Argonne Xeon cluster. > >>> > >> > >> Interesting. I tested on Cori's Haswell nodes and it looked fine. I did > >> not time it but seemed OK. > >> > >> > >>> I repeated the experiments on Cori's Haswell nodes. --with-openmp=1, > >>> "Linear solve converged due to CONVERGED_RTOL iterations 5". But it took > >>> very long time (10 mins). Without --with-openmp=1, it took less than 1 > >>> second. > >>> > >> > >> Humm. I seemed to run OK on Cori's Haswell nodes. Where you running a > >> significant sized job? I was test small serial runs. > >> > > > > I ran with 27 processors and each had 30^3 unknowns. > > > >> > >> > >>> > >>> --Junchao Zhang > >>> > >>> On Fri, Jun 22, 2018 at 3:33 PM, Mark Adams <[email protected]> wrote: > >>> > >>>> We are using KNL (Cori) and hypre is not working when configured > >>>> with '--with-openmp=1', even when not using threads (as far as I can > >>>> tell, > >>>> I never use threads). > >>>> > >>>> Hypre is not converging, for instance with an optimized build: > >>>> > >>>> srun -n 1 ./ex56 -pc_type hypre -ksp_monitor -ksp_converged_reason > >>>> -ksp_type cg -pc_hypre_type boomeramg > >>>> OMP: Warning #239: KMP_AFFINITY: granularity=fine will be used. > >>>> 0 KSP Residual norm 7.366251922394e+22 > >>>> 1 KSP Residual norm 3.676434682799e+22 > >>>> Linear solve did not converge due to DIVERGED_INDEFINITE_PC iterations 2 > >>>> > >>>> Interestingly in debug mode it almost looks good but it is dying: > >>>> > >>>> 05:09 nid02516 maint *= > >>>> ~/petsc_install/petsc/src/ksp/ksp/examples/tutorials$ make > >>>> PETSC_DIR=/global/homes/m/madams/petsc_install/petsc-cori-knl-dbg64-intel-omp > >>>> PETSC_ARCH="" run > >>>> srun -n 1 ./ex56 -pc_type hypre -ksp_monitor -ksp_converged_reason > >>>> -ksp_type cg -pc_hypre_type boomeramg > >>>> OMP: Warning #239: KMP_AFFINITY: granularity=fine will be used. > >>>> 0 KSP Residual norm 7.882081712007e+02 > >>>> 1 KSP Residual norm 2.500214073037e+02 > >>>> 2 KSP Residual norm 3.371746347713e+01 > >>>> 3 KSP Residual norm 2.918759396143e+00 > >>>> 4 KSP Residual norm 9.006505495017e-01 > >>>> Linear solve did not converge due to DIVERGED_INDEFINITE_PC iterations 5 > >>>> > >>>> This test runs fine on Xeon nodes. I assume that Hypre has been tested > >>>> on KNL. GAMG runs fine, of coarse and the initial residual is similar to > >>>> this debug run. > >>>> > >>>> Could PETSc be messing up the matrix conversion to hypre > >>>> '--with-openmp=1' ? > >>>> > >>>> Any ideas? > >>>> > >>>> Thanks, > >>>> Mark > >>>> > >>>> > >>> > > >
