Matthew Knepley wrote: >The routine which calculates ICC requested 3G, so it seems that the matrix >is too dense or large to be factored on this machine. > > Matt > >On Nov 2, 2007 7:54 AM, Zhifeng Sheng <z.sheng at ewi.tudelft.nl> wrote: > > >>Dear all >> >>I have a problem for memory management. >> >>I implemented 3d FEM code and at this moment SeqSBAIJ is used to store >>the system matrix, then I used CG method and ICC(k) preconditioner. >> >>The test configuration is not very big, I succeeded in constructing the >>system matrix and construct the preconditioner. But when I need to setup >>the KSP solver, I got the error message below ( I also dumped some >>information about solver and system matrix): >> >>KSP Object: >> type: cg >> maximum iterations=10000, initial guess is zero >> tolerances: relative=1e-09, absolute=1e-50, divergence=10000 >> left preconditioning >>PC Object: >> type: icc >> ICC: 2 levels of fill >> ICC: factor fill ratio allocated 1 >> linear system matrix = precond matrix: >> Matrix Object: >> type=seqsbaij, rows=435450, cols=435450 >> total: nonzeros=9470450, allocated nonzeros=21772580 >> block size is 1 >>[0]PETSC ERROR: --------------------- Error Message >>------------------------------------ >>[0]PETSC ERROR: Out of memory. This could be due to allocating >>[0]PETSC ERROR: too large an object or bleeding by not properly >>[0]PETSC ERROR: destroying unneeded objects. >>[0]PETSC ERROR: Memory allocated 375435120 Memory used by process 428597248 >>[0]PETSC ERROR: Try running with -malloc_dump or -malloc_log for info. >>[0]PETSC ERROR: Memory requested 3108507040! >>[0]PETSC ERROR: >>------------------------------------------------------------------------ >>[0]PETSC ERROR: Petsc Release Version 2.3.2, Patch 10, Wed Mar 28 >>19:13:22 CDT 2007 HG revision: d7298c71db7f5e767f359ae35d33cab3bed44428 >>[0]PETSC ERROR: See docs/changes/index.html for recent updates. >>[0]PETSC ERROR: See docs/faq.html for hints about trouble shooting. >>[0]PETSC ERROR: See docs/index.html for manual pages. >>[0]PETSC ERROR: >>------------------------------------------------------------------------ >>[0]PETSC ERROR: bin/main on a linux-gnu named callisto by zhifeng Fri >>Nov 2 13:26:39 2007 >>[0]PETSC ERROR: Libraries linked from >>/u/01/01/zhifeng/install/lib/linux-gnu-c-debug >>[0]PETSC ERROR: Configure run at Wed Aug 8 13:46:26 2007 >>[0]PETSC ERROR: Configure options --with-cc=gcc --with-fc=g77 >>--download-f-blas-lapack=1 --download-mpich=1 >>--prefix=/u/01/01/zhifeng/install --with-shared=0 >>[0]PETSC ERROR: >>------------------------------------------------------------------------ >>[0]PETSC ERROR: PetscMallocAlign() line 61 in src/sys/memory/mal.c >>[0]PETSC ERROR: PetscTrMallocDefault() line 194 in src/sys/memory/mtr.c >>[0]PETSC ERROR: PetscFreeSpaceGet() line 14 in src/mat/utils/freespace.c >>[0]PETSC ERROR: MatICCFactorSymbolic_SeqSBAIJ() line 1648 in >>src/mat/impls/sbaij/seq/sbaijfact2.c >>[0]PETSC ERROR: MatICCFactorSymbolic() line 4611 in >>src/mat/interface/matrix.c >>[0]PETSC ERROR: PCSetup_ICC() line 117 in src/ksp/pc/impls/factor/icc/icc.c >>[0]PETSC ERROR: PCSetUp() line 801 in src/ksp/pc/interface/precon.c >>[0]PETSC ERROR: KSPSetUp() line 234 in src/ksp/ksp/interface/itfunc.c >>[0]PETSC ERROR: KSPSolve() line 338 in src/ksp/ksp/interface/itfunc.c >>=====================the solver convergence info====================== >>Convergence in 0 iterations. >>===================================================================== >>writing solution to file temp_H.vtk ... >>number of unknowns >>435450 >>finishing the numeric solver ... >>LSFIM hybrid method for four domain problem >>deallocating memory of domain class ... >> >> >>I debug the code, and the error is dumped by the funciton KSPSetUp() >>which should not take so much memory, but still 3108507040 memory was >>requested .... I really could not figure out where I need them... >> >>Any help will be appreciated. >> >>Thank you all >>Best regards >>Zhifeng >> >> >> >> > > > > > So ... computation of the preconditioner is actually called by KSPSetUp() instead of PCGetFactoredMatrix(prec,&M)?
Could you please tell me when the system matrix be factorized (incompletely)? thank you. Zhifeng
