[petsc-users] multigrid preconditioning and adaptivity

[Lukasz Kaczmarczyk]

Hello,

I run multi-grid solver, with adaptivity, works well, however It is some space for improving efficiency. I using hierarchical approximation basis, for which 
construction of interpolation operators is simple, it is simple injection. 

After each refinement level (increase of order of approximation on some element) I rebuild multigrid pre-conditioner with additional level. It is a way to add dynamically new levels without need of rebuilding whole MG pre-conditioner.  

Looking at execution profile I noticed that 50%-60% of time is spent on MatPtAP function during PCSetUP stage. 

Kind regards,
Lukasz