[petsc-users] SIGSEGV in Superlu_dist

Hong hzhang at mcs.anl.gov
Wed Aug 12 10:58:50 CDT 2015


Anthony,
I just patched petsc-maint branch.

Your matrix Amat_binary.m has empty diagonal blocks. Most petsc solvers
require matrix diagonal entries to be allocated as 'non-zero', i.e., insert
zero values to these zero entries. I would suggest you add zeros to
 Amat_binary.m during its buildup. This would enable petsc solvers, as well
as other packages.

Again, thanks for bug reporting.

Hong

On Tue, Aug 11, 2015 at 1:33 PM, Satish Balay <balay at mcs.anl.gov> wrote:

> yes - the patch will be in petsc 3.6.2.
>
> However - you can grab the patch right now - and start using it
>
> If using a 3.6.1 tarball - you can do download the (raw) patch from
> the url below and apply with:
>
> cd petsc-3.6.1
> patch -Np1 < patchfile
>
> If using a git clone - you can do:
>
> git fetch
> git checkout ceeba3afeff0c18262ed13ef92e2508ca68b0ecf
>
> Satish
>
> On Tue, 11 Aug 2015, Anthony Haas wrote:
>
> > Hi Hong,
> >
> > Sorry for my late reply and thanks for the fix. Does that mean that I
> will be
> > able to run that matrix on 10 procs in the future (petsc 3.6.2?)?
> >
> > Thanks
> >
> > Anthony
> >
> >
> > On 08/11/2015 09:58 AM, Hong wrote:
> > > Anthony,
> > > I pushed a fix
> > >
> https://bitbucket.org/petsc/petsc/commits/ceeba3afeff0c18262ed13ef92e2508ca68b0ecf
> > >
> > > Once it passes our nightly tests, I'll merge it to petsc-maint, then
> > > petsc-dev.
> > > Thanks for reporting it!
> > >
> > > Hong
> > >
> > > On Mon, Aug 10, 2015 at 4:27 PM, Barry Smith <bsmith at mcs.anl.gov
> > > <mailto:bsmith at mcs.anl.gov>> wrote:
> > >
> > >
> > >       Anthony,
> > >
> > >        This crash is in PETSc code before it calls the SuperLU_DIST
> > >     numeric factorization; likely we have a mistake such as assuming a
> > >     process has at least one row of the matrix and need to fix it.
> > >
> > >        Barry
> > >
> > >     > 0x00007fe6ba609297 in MatLUFactorNumeric_SuperLU_DIST
> (F=0x1922b50,
> > >     >    A=0x14a6a70, info=0x19099f8)
> > >     >    at
> > >
>  /home/anthony/LIB/petsc-3.6.1/src/mat/impls/aij/mpi/superlu_dist/superlu_dist.c:368
> > >     > 368           colA_start = rstart + ajj[0]; /* the smallest
> > >     global col index of A */
> > >
> > >
> > >
> > >     > On Aug 10, 2015, at 3:50 PM, Anthony Haas <aph at email.arizona.edu
> > >     <mailto:aph at email.arizona.edu>> wrote:
> > >     >
> > >     > Hi Sherry,
> > >     >
> > >     > I recently submitted a matrix for which I noticed that
> > >     Superlu_dist was hanging when running on 4 processors with
> > >     parallel symbolic factorization. I have been using the latest
> > >     version of Superlu_dist and the code is not hanging anymore.
> > >     However, I noticed that when running the same matrix (I have
> > >     attached the matrix), the code crashes with the following SIGSEGV
> > >     when running on 10 procs (with or without parallel symbolic
> > >     factorization). It is probably overkill to run such a 'small'
> > >     matrix on 10 procs but I thought that it might still be useful to
> > >     report the problem?? See below for the error obtained when running
> > >     with gdb and also a code snippet to reproduce the error.
> > >     >
> > >     > Thanks,
> > >     >
> > >     >
> > >     > Anthony
> > >     >
> > >     >
> > >     >
> > >     > 1) ERROR in GDB
> > >     >
> > >     > Program received signal SIGSEGV, Segmentation fault.
> > >     > 0x00007fe6ba609297 in MatLUFactorNumeric_SuperLU_DIST
> (F=0x1922b50,
> > >     >    A=0x14a6a70, info=0x19099f8)
> > >     >    at
> > >
>  /home/anthony/LIB/petsc-3.6.1/src/mat/impls/aij/mpi/superlu_dist/superlu_dist.c:368
> > >     > 368           colA_start = rstart + ajj[0]; /* the smallest
> > >     global col index of A */
> > >     > (gdb)
> > >     >
> > >     >
> > >     >
> > >     > 2) PORTION OF CODE TO REPRODUCE ERROR
> > >     >
> > >     >    Subroutine HowBigLUCanBe(rank)
> > >     >
> > >     >      IMPLICIT NONE
> > >     >
> > >     >      integer(i4b),intent(in) :: rank
> > >     >      integer(i4b)            :: i,ct
> > >     >      real(dp)                :: begin,endd
> > >     >      complex(dpc)            :: sigma
> > >     >
> > >     >      PetscErrorCode ierr
> > >     >
> > >     >
> > >     >      if (rank==0) call cpu_time(begin)
> > >     >
> > >     >      if (rank==0) then
> > >     >         write(*,*)
> > >     >         write(*,*)'Testing How Big LU Can Be...'
> > >     >         write(*,*)'============================'
> > >     >         write(*,*)
> > >     >      endif
> > >     >
> > >     >      !sigma = (1.0d0,0.0d0)
> > >     >      !call MatAXPY(A,-sigma,B,DIFFERENT_NONZERO_PATTERN,ierr) !
> > >     on exit A = A-sigma*B
> > >     >
> > >     >      !call MatView(A,PETSC_VIEWER_STDOUT_WORLD,ierr)
> > >     >
> > >     > !.....Write Matrix to ASCII and Binary Format
> > >     >      !call
> > >     PetscViewerASCIIOpen(PETSC_COMM_WORLD,"Amat.m",viewer,ierr)
> > >     >      !call MatView(DXX,viewer,ierr)
> > >     >      !call PetscViewerDestroy(viewer,ierr)
> > >     >
> > >     >      !call
> > >
>  PetscViewerBinaryOpen(PETSC_COMM_WORLD,"Amat_binary.m",FILE_MODE_WRITE,viewer,ierr)
> > >     >      !call MatView(A,viewer,ierr)
> > >     >      !call PetscViewerDestroy(viewer,ierr)
> > >     >
> > >     > !...Load a Matrix in Binary Format
> > >     >      call
> > >
>  PetscViewerBinaryOpen(PETSC_COMM_WORLD,"Amat_binary.m",FILE_MODE_READ,viewer,ierr)
> > >     >      call MatCreate(PETSC_COMM_WORLD,DLOAD,ierr)
> > >     >      call MatSetType(DLOAD,MATAIJ,ierr)
> > >     >      call MatLoad(DLOAD,viewer,ierr)
> > >     >      call PetscViewerDestroy(viewer,ierr)
> > >     >
> > >     >      !call MatView(DLOAD,PETSC_VIEWER_STDOUT_WORLD,ierr)
> > >     >
> > >     >
> > >     > !.....Create Linear Solver Context
> > >     >      call KSPCreate(PETSC_COMM_WORLD,ksp,ierr)
> > >     >
> > >     > !.....Set operators. Here the matrix that defines the linear
> > >     system also serves as the preconditioning matrix.
> > >     >      !call
> > >     KSPSetOperators(ksp,A,A,DIFFERENT_NONZERO_PATTERN,ierr) !aha
> > >     commented and replaced by next line
> > >     >
> > >     >      !call KSPSetOperators(ksp,A,A,ierr) ! remember: here A =
> > >     A-sigma*B
> > >     >      call KSPSetOperators(ksp,DLOAD,DLOAD,ierr) ! remember: here
> > >     A = A-sigma*B
> > >     >
> > >     > !.....Set Relative and Absolute Tolerances and Uses Default for
> > >     Divergence Tol
> > >     >      tol = 1.e-10
> > >     >      call
> > >
>  KSPSetTolerances(ksp,tol,tol,PETSC_DEFAULT_REAL,PETSC_DEFAULT_INTEGER,ierr)
> > >     >
> > >     > !.....Set the Direct (LU) Solver
> > >     >      call KSPSetType(ksp,KSPPREONLY,ierr)
> > >     >      call KSPGetPC(ksp,pc,ierr)
> > >     >      call PCSetType(pc,PCLU,ierr)
> > >     >      call
> > >     PCFactorSetMatSolverPackage(pc,MATSOLVERSUPERLU_DIST,ierr) !
> > >     MATSOLVERSUPERLU_DIST MATSOLVERMUMPS
> > >     >
> > >     > !.....Create Right-Hand-Side Vector
> > >     >      !call MatCreateVecs(A,frhs,PETSC_NULL_OBJECT,ierr)
> > >     >      !call MatCreateVecs(A,sol,PETSC_NULL_OBJECT,ierr)
> > >     >
> > >     >      call MatCreateVecs(DLOAD,frhs,PETSC_NULL_OBJECT,ierr)
> > >     >      call MatCreateVecs(DLOAD,sol,PETSC_NULL_OBJECT,ierr)
> > >     >
> > >     >      call
> > >     MatGetOwnershipRange(DLOAD,IstartA,IendA,ierr)!;CHKERRQ(ierr)
> > >     >
> > >     >      allocate(xwork1(IendA-IstartA))
> > >     >      allocate(loc(IendA-IstartA))
> > >     >
> > >     >      ct=0
> > >     >      do i=IstartA,IendA-1
> > >     >         ct=ct+1
> > >     >         loc(ct)=i
> > >     >         xwork1(ct)=(1.0d0,0.0d0)
> > >     >      enddo
> > >     >
> > >     >      call
> > >     VecSetValues(frhs,IendA-IstartA,loc,xwork1,INSERT_VALUES,ierr)
> > >     >      call VecZeroEntries(sol,ierr)
> > >     >
> > >     >      deallocate(xwork1,loc)
> > >     >
> > >     > !.....Assemble Vectors
> > >     >      call VecAssemblyBegin(frhs,ierr)
> > >     >      call VecAssemblyEnd(frhs,ierr)
> > >     >
> > >     > !.....Solve the Linear System
> > >     >      call KSPSolve(ksp,frhs,sol,ierr)
> > >     >
> > >     >      !call VecView(sol,PETSC_VIEWER_STDOUT_WORLD,ierr)
> > >     >
> > >     >      if (rank==0) then
> > >     >         call cpu_time(endd)
> > >     >         write(*,*)
> > >     >         print '("Total time for HowBigLUCanBe = ",f21.3,"
> > >     seconds.")',endd-begin
> > >     >      endif
> > >     >
> > >     >      call SlepcFinalize(ierr)
> > >     >
> > >     >      STOP
> > >     >
> > >     >
> > >     >    end Subroutine HowBigLUCanBe
> > >     >
> > >     > <Amat_binary.m.info <http://Amat_binary.m.info>>
> > >
> > >
> >
> >
>
>
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