On Tue, Feb 9, 2021 at 4:30 AM Chen Gang <[email protected]> wrote:
Dear Professor,
I have a question about the bjacobi+ilu, I'm in the place
src/ksp/ksp/tutorials
and running the ex2 with
mpirun -np 40 -bind-to core ./ex2 -m 2000 -n 2000 -ksp_max_it 1000000 -ksp_rtol 1e-10 -ksp_type gmres -pc_type bjacobi -sub_pc_type ilu -sub_pc_factor_levels 10 -ksp_monitor_short
on the Intel machine with 40 cores, the petsc is complied with MKL and ICC/MPIICC with O3.
I found the numerical results are not the same from time to time, although they all right, the iterations are not exactly the same from time to time. Where have I done wrong?
MPI does not guarantee the order that reductions are calculated, so that you can get slightly different answers in parallel. Thanks, Matt
I'm looking forward to hear you!
Best,
Gang Chen
Sichuan Univertsity, School of Mathematics, Chengdu, China
-- What most experimenters take for granted before they begin their experiments is infinitely more interesting than any results to which their experiments lead. -- Norbert Wiener https://www.cse.buffalo.edu/~knepley/ <http://www.cse.buffalo.edu/~knepley/>