[petsc-users] SNESComputeJacobianDefaultColor use too much memory

[Rongliang Chen]

Dear all,

I am using the DMPlex to solve a PDE on a unstructured mesh and I use 
the SNESComputeJacobianDefaultColor to compute the Jacobian matrix.

My code works well for small problems (such as problem with 3.3x10^5 
cells using 120 cores) but when I increase the number of cells (2.6x10^6 
cells using 1920 cores), I go out of memory in the function 
MatColoringApply. It shows that one of the cores uses over 11G memory. I 
think this is unreasonable. Do you have any suggestions for debugging 
this problem?

Best regards,
Rongliang