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

[TAY wee-beng]

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,

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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
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