[petsc-users] slepc trap for large matrix

[Barry Smith]

  The resulting matrix has something like

>>> 119999808*119999808*1.e-6
14,399,953,920.036863

  nonzero entries. It is possible that some integer operations are overflowing since C int can only go up to about 4 billion before overflowing.

  You can building with a different PETSC_ARCH value using the additional ./configure option for PETSc of --with-64-bit-indices and see if the problem is resolved.

   Barry


> On Jun 5, 2017, at 12:37 PM, Kannan, Ramakrishnan <kannanr at ornl.gov> wrote:
> 
> I am running EPS for NHEP on a matrix of size 119999808x119999808 and I am experiencing the attached trapped. This is a 1D row distributed sparse uniform random matrix with 1e-6 sparsity  over 36 processors. It works fine for smaller matrices of sizes with 1.2 million x 1.2 million. Let me know if you are looking for more information.
>  
> -- 
> Regards,
> Ramki
>  
> <slepc.e609742.zip>