understanding the output from -info

[Ben Tay]

Hi,

I've tried to use log_summary but nothing came out? Did I miss out
something? It worked when I used -info...


On 2/9/07, Lisandro Dalcin <dalcinl at gmail.com> wrote:
>
> On 2/8/07, Ben Tay <zonexo at gmail.com> wrote:
> > i'm trying to solve my cfd code using PETSc in parallel. Besides the
> linear
> > eqns for PETSc, other parts of the code has also been parallelized using
> > MPI.
>
> Finite elements or finite differences, or what?
>
> > however i find that the parallel version of the code running on 4
> processors
> > is even slower than the sequential version.
>
> Can you monitor the convergence and iteration count of momentum and
> poisson steps?
>
>
> > in order to find out why, i've used the -info option to print out the
> > details. there are 2 linear equations being solved - momentum and
> poisson.
> > the momentum one is twice the size of the poisson. it is shown below:
>
> Can you use -log_summary command line option and send the output attached?
>
> > i saw some statements stating "seq". am i running in sequential or
> parallel
> > mode? have i preallocated too much space?
>
> It seems you are running in parallel. The "Seq" are related to local,
> internal objects. In PETSc, parallel matrices have inner sequential
> matrices.
>
> > lastly, if Ax=b, A_sta and A_end from  MatGetOwnershipRange and b_sta
> and
> > b_end from VecGetOwnershipRange should always be the same value, right?
>
> I should. If not, you are likely going to get an runtime error.
>
> Regards,
>
> --
> Lisandro Dalcín
> ---------------
> Centro Internacional de Métodos Computacionales en Ingeniería (CIMEC)
> Instituto de Desarrollo Tecnológico para la Industria Química (INTEC)
> Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET)
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> Tel/Fax: +54-(0)342-451.1594
>
>
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