UMFPACK out of memory
fpacull at fluorem.com
Tue Oct 27 10:12:21 CDT 2009
Dear PETSc team,
I have a few questions... During the resolution of a linear system in
parallel, I am trying to apply a local LU solver to each of the SEQaij
diagonal blocks of a MPIaij matrix partitioned with PARMETIS.
- I started with MUMPS but it seems that it only works with
unpartitioned aij matrices, is it really the case? Or could we use MUMPS
to build an additive Schwarz preconditioner for example?
- Then I tried UMFPACK. This works fine when the diagonal blocks (and
the memory required to store the factors) are small but crashes when
they are a little bit larger. For example with a "numeric final size" of
4203.7 MBytes, I got the following message "ERROR: out of memory" while
there was plenty of memory left in the computer. I tried either with the
UMFPACK version 5.2, downloaded by PETSc, or with a manually installed
version 5.4, linked to PETSc. Is this a behavior from UMFPACK that you
- Since UMFPACK seemed to have a memory limit around 4096 MB, I tried
to install a PETSc version with the option "--with-64-bit-indices",
however none of the partitioning packages could be compiled with this
option (parmetis,chaco,jostle,party,scotch). Is there a way to compile
PETSc with 64 bit indices AND a partitioning package?
- Finally, I tried to modify the PETSc source code umfpack.c so that it
would deal with 64 bit indices, but I only ended up so far with a
segmentation violation message at the execution... Is it the only way I
could use UMPACK with large sparse matrices?
More information about the petsc-users