[petsc-users] Problem with solving Poisson eqn for some cases

[Smith, Barry F.]

http://www.mcs.anl.gov/petsc/documentation/faq.html#valgrind

> On Mar 15, 2018, at 1:51 AM, TAY wee-beng <zonexo at gmail.com> wrote:
> 
> Hi,
> 
> I'm running a CFD code which solves the momentum and Poisson eqns.
> 
> Due to poor scaling with HYPRE at higher cpu no., I decided to try using PETSc with boomeramg and gamg.
> 
> I tested for some small cases and it work well. However, for the large problem which has poor scaling, it gives an error when I change my Poisson solver from pure HYPRE to PETSc with boomeramg and gamg.
> 
> The error is :
> 
> Caught signal number 11 SEGV: Segmentation Violation, probably memory access out of range
> 
> I tried using:
> 
> -poisson_ksp_type richardson -poisson_pc_type hypre -poisson_pc_type_hypre boomeramg
> 
> -poisson_ksp_type gmres -poisson_pc_type hypre -poisson_pc_type_hypre boomeramg
> 
> -poisson_pc_type gamg -poisson_pc_gamg_agg_nsmooths 1
> 
> but they all gave similar error.
> 
> So why is this so? How should I troubleshoot? I am now running a debug ver of PETSc to check the error msg.
> 
> 
> 
> -- 
> Thank you very much.
> 
> Yours sincerely,
> 
> ================================================
> TAY Wee-Beng (Zheng Weiming) 郑伟明
> Personal research webpage: http://tayweebeng.wixsite.com/website
> Youtube research showcase: https://www.youtube.com/channel/UC72ZHtvQNMpNs2uRTSToiLA
> linkedin: www.linkedin.com/in/tay-weebeng
> ================================================
>