[petsc-users] Strange Partition in PETSc 3.11 version on some computers

Mon Sep 16 14:02:55 CDT 2019

On Mon, Sep 16, 2019 at 1:46 PM Smith, Barry F. <bsmith at mcs.anl.gov> wrote:

>
>   Very different stuff going on in the two cases, different objects being
> created, different number of different types of operations. Clearly a major
> refactorization of the code was done. Presumably a regression was
> introduced that changed the behavior dramatically, possible by mistake.
>
>    You can attempt to use git bisect to determine what changed caused the
> dramatic change in behavior. Then it can be decided if the changed that
> triggered the change in the results was a bug or a planned feature.
>

Danyang,

Can you send me the smallest mesh you care about, and I will look at the
partitioning? We can at least get quality metrics
between these two releases.

  Thanks,

     Matt

>    Barry
>
>
> > On Sep 16, 2019, at 11:50 AM, Danyang Su <danyang.su at gmail.com> wrote:
> >
> > Hi Barry and Matt,
> >
> > Attached is the output of both runs with -dm_view -log_view included.
> >
> > I am now coordinating with staff to install PETSc 3.9.3 version using
> intel2019u4 to narrow down the problem. Will get back to you later after
> the test.
> >
> > Thanks,
> >
> > Danyang
> >
> > On 2019-09-15 4:43 p.m., Smith, Barry F. wrote:
> >>   Send the configure.log and make.log for the two system configurations
> that produce very different results as well as the output running with
> -dm_view -info for both runs. The cause is likely not subtle, one is likely
> using metis and the other is likely just not using any partitioner.
> >>
> >>
> >>
> >>> On Sep 15, 2019, at 6:07 PM, Matthew Knepley via petsc-users <
> petsc-users at mcs.anl.gov> wrote:
> >>>
> >>> On Sun, Sep 15, 2019 at 6:59 PM Danyang Su <danyang.su at gmail.com>
> wrote:
> >>> Hi Matt,
> >>>
> >>> Thanks for the quick reply. I have no change in the adjacency. The
> source code and the simulation input files are all the same. I also tried
> to use GNU compiler and mpich with petsc 3.11.3 and it works fine.
> >>>
> >>> It looks like the problem is caused by the difference in
> configuration. However, the configuration is pretty the same as petsc 3.9.3
> except the compiler and mpi used. I will contact scinet staff to check if
> they have any idea on this.
> >>>
> >>> Very very strange since the partition is handled completely by Metis,
> and does not use MPI.
> >>>
> >>>   Thanks,
> >>>
> >>>     Matt
> >>>  Thanks,
> >>>
> >>> Danyang
> >>>
> >>> On September 15, 2019 3:20:18 p.m. PDT, Matthew Knepley <
> knepley at gmail.com> wrote:
> >>> On Sun, Sep 15, 2019 at 5:19 PM Danyang Su via petsc-users <
> petsc-users at mcs.anl.gov> wrote:
> >>> Dear All,
> >>>
> >>> I have a question regarding strange partition problem in PETSc 3.11
> version. The problem does not exist on my local workstation. However, on a
> cluster with different PETSc versions, the partition seems quite different,
> as you can find in the figure below, which is tested with 160 processors.
> The color means the processor owns that subdomain. In this layered prism
> mesh, there are 40 layers from bottom to top and each layer has around 20k
> nodes. The natural order of nodes is also layered from bottom to top.
> >>>
> >>> The left partition (PETSc 3.10 and earlier) looks good with minimum
> number of ghost nodes while the right one (PETSc 3.11) looks weired with
> huge number of ghost nodes. Looks like the right one uses partition layer
> by layer. This problem exists on a a cluster but not on my local
> workstation for the same PETSc version (with different compiler and MPI).
> Other than the difference in partition and efficiency, the simulation
> results are the same.
> >>>
> >>>
> >>>
> >>>
> >>> Below is PETSc configuration on three machine:
> >>>
> >>> Local workstation (works fine):  ./configure --with-cc=gcc
> --with-cxx=g++ --with-fc=gfortran --download-mpich --download-scalapack
> --download-parmetis --download-metis --download-ptscotch
> --download-fblaslapack --download-hypre --download-superlu_dist
> --download-hdf5=yes --download-ctetgen --with-debugging=0 COPTFLAGS=-O3
> CXXOPTFLAGS=-O3 FOPTFLAGS=-O3 --with-cxx-dialect=C++11
> >>>
> >>> Cluster with PETSc 3.9.3 (works fine):
> --prefix=/scinet/niagara/software/2018a/opt/intel-2018.2-intelmpi-2018.2/petsc/3.9.3
> CC=mpicc CXX=mpicxx F77=mpif77 F90=mpif90 FC=mpifc COPTFLAGS="-march=native
> -O2" CXXOPTFLAGS="-march=native -O2" FOPTFLAGS="-march=native -O2"
> --download-chaco=1 --download-hypre=1 --download-metis=1 --download-ml=1
> --download-mumps=1 --download-parmetis=1 --download-plapack=1
> --download-prometheus=1 --download-ptscotch=1 --download-scotch=1
> --download-sprng=1 --download-superlu=1 --download-superlu_dist=1
> --download-triangle=1 --with-avx512-kernels=1
> --with-blaslapack-dir=/scinet/niagara/intel/2018.2/compilers_and_libraries_2018.2.199/linux/mkl
> --with-debugging=0 --with-hdf5=1
> --with-mkl_pardiso-dir=/scinet/niagara/intel/2018.2/compilers_and_libraries_2018.2.199/linux/mkl
> --with-scalapack=1
> --with-scalapack-lib="[/scinet/niagara/intel/2018.2/compilers_and_libraries_2018.2.199/linux/mkl/lib/intel64/libmkl_scalapack_lp64.so,/scinet/niagara/intel/2018.2/compilers_and_libraries_2018.2.199/linux/mkl/lib/intel64/libmkl_blacs_intelmpi_lp64.so]"
> --with-x=0
> >>>
> >>> Cluster with PETSc 3.11.3 (looks weired):
> --prefix=/scinet/niagara/software/2019b/opt/intel-2019u4-intelmpi-2019u4/petsc/3.11.3
> CC=mpicc CXX=mpicxx F77=mpif77 F90=mpif90 FC=mpifc COPTFLAGS="-march=native
> -O2" CXXOPTFLAGS="-march=native -O2" FOPTFLAGS="-march=native -O2"
> --download-chaco=1 --download-hdf5=1 --download-hypre=1 --download-metis=1
> --download-ml=1 --download-mumps=1 --download-parmetis=1
> --download-plapack=1 --download-prometheus=1 --download-ptscotch=1
> --download-scotch=1 --download-sprng=1 --download-superlu=1
> --download-superlu_dist=1 --download-triangle=1 --with-avx512-kernels=1
> --with-blaslapack-dir=/scinet/intel/2019u4/compilers_and_libraries_2019.4.243/linux/mkl
> --with-cxx-dialect=C++11 --with-debugging=0
> --with-mkl_pardiso-dir=/scinet/intel/2019u4/compilers_and_libraries_2019.4.243/linux/mkl
> --with-scalapack=1
> --with-scalapack-lib="[/scinet/intel/2019u4/compilers_and_libraries_2019.4.243/linux/mkl/lib/intel64/libmkl_scalapack_lp64.so,/scinet/intel/2019u4/compilers_and_libraries_2019.4.243/linux/mkl/lib/intel64/libmkl_blacs_intelmpi_lp64.so]"
> --with-x=0
> >>>
> >>> And the partition is used by default dmplex distribution.
> >>>
> >>>       !c distribute mesh over processes
> >>>       call DMPlexDistribute(dmda_flow%da,stencil_width,
> &
> >>>                             PETSC_NULL_SF,
>  &
> >>>                             PETSC_NULL_OBJECT,
>  &
> >>>                             distributedMesh,ierr)
> >>>       CHKERRQ(ierr)
> >>>
> >>> Any idea on this strange problem?
> >>>
> >>>
> >>> I just looked at the code. Your mesh should be partitioned by k-way
> partitioning using Metis since its on 1 proc for partitioning. This code
> >>> is the same for 3.9 and 3.11, and you get the same result on your
> machine. I cannot understand what might be happening on your cluster
> >>> (MPI plays no role). Is it possible that you changed the adjacency
> specification in that version?
> >>>
> >>>   Thanks,
> >>>
> >>>      Matt
> >>> Thanks,
> >>>
> >>> Danyang
> >>>
> >>>
> >>>
> >>> --
> >>> 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/
> >>>
> >>> --
> >>> Sent from my Android device with K-9 Mail. Please excuse my brevity.
> >>>
> >>>
> >>> --
> >>> 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/
> > <basin-petsc-3.9.3.log><basin-petsc-3.11.3.log>
>
>

-- 
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/>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.mcs.anl.gov/pipermail/petsc-users/attachments/20190916/dfaa9154/attachment-0001.html>