[petsc-users] MUMPS error and superLU error

[Hong]

'A serial job in MATLAB for the same matrices takes < 60GB. '
Can you run this case in serial? If so, try petsc, superlu or mumps to make
sure the matrix is non-singular.

Both mumps and superlu_dist show crash in MatFactorNumeric(). Mumps gives
error
[16]PETSC ERROR: Error reported by MUMPS in numerical factorization phase:
Cannot allocate required memory 65710 megabytes.

Does your code work for smaller problems?
Try using more processors?

Why use such huge '-mat_mumps_icntl_14 200000' (percentage of estimated
workspace increase)? The default is 20. Try 40?

Superlu_dist usually uses less memory than mumps, but it also crashes. I
guess something wrong with your matrix. Is it singular?
Run superlu_dist on a slightly smaller matrix with option
'-mat_superlu_dist_statprint' which displays memory usage info., e.g.,

petsc/src/ksp/ksp/examples/tutorials (maint)
$ mpiexec -n 2 ./ex2 -pc_type lu -pc_factor_mat_solver_package superlu_dist
-mat_superlu_dist_statprint
Nonzeros in L       560
Nonzeros in U       560
nonzeros in L+U     1064
nonzeros in LSUB    248
NUMfact space (MB) sum(procs):  L\U 0.01 all 0.05
Total highmark (MB):  All 0.05 Avg 0.02 Max 0.02
EQUIL time             0.00
ROWPERM time           0.00
COLPERM time           0.00
SYMBFACT time          0.00
DISTRIBUTE time        0.00
FACTOR time            0.00
Factor flops 1.181000e+04 Mflops     4.80
SOLVE time             0.00
SOLVE time             0.00
Solve flops 2.194000e+03 Mflops     4.43
SOLVE time             0.00
Solve flops 2.194000e+03 Mflops     5.14
Norm of error 1.18018e-15 iterations 1

Hong


On Tue, May 26, 2015 at 9:03 AM, venkatesh g <venkateshgk.j at gmail.com>
wrote:

> I posted a while ago in MUMPS forums but no one seems to reply.
>
> I am solving a large generalized Eigenvalue problem.
>
> I am getting the following error which is attached, after giving the
> command:
>
> /cluster/share/venkatesh/petsc-3.5.3/linux-gnu/bin/mpiexec -np 64 -hosts
> compute-0-4,compute-0-6,compute-0-7,compute-0-8 ./ex7 -f1 a72t -f2 b72t
> -st_type sinvert -eps_nev 3 -eps_target 0.5 -st_ksp_type preonly
> -st_pc_type lu -st_pc_factor_mat_solver_package mumps -mat_mumps_icntl_14
> 200000
>
> IT IS impossible to allocate so much memory per processor.. it is asking
> like around 70 GB per processor.
>
> A serial job in MATLAB for the same matrices takes < 60GB.
>
> After trying out superLU_dist, I have attached the error there also
> (segmentation error).
>
> Kindly help me.
>
> Venkatesh
>
>
>
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