[petsc-users] SuperLU_dist bug with parallel symbolic factorisation

[Eric Chamberland]

On 22/05/18 12:11 PM, Xiaoye S. Li wrote:
 > Default setting is to use sequential symbolic factorization, precisely
 > due to the ParMETIS bugs.

Ok,

and I saw you reported the bug "a few years ago" and still have not 
received a fix...

I would like to "live with the patch" (ie working in sequential) but our 
problem is that if we compute err=|Ax-b|, the resolution with 
*sequential* symbolic factorisation gives ans err around 1e-6 instead of 
1e-16 for parallel one (when it works).  MUMPS, also gives 1e-16 error 
levels.

In our nightly tests we have to compare computed solutions and they are 
now acceptable if they are of the order of 1e-15.  I do *not* want to 
raise this comparison to 1e-6 just because there is a bug in parmetis 
which forces us to use the "unprecise" sequential options...

In other words, I am kind of "stuck" with this non-fixed bug now... :/

Hope this can be fixed...

Thanks,

Eric