understanding the output from -info

[Barry Smith]

  -log_summary


On Fri, 9 Feb 2007, Ben Tay wrote:

> 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)
> > PTLC - Güemes 3450, (3000) Santa Fe, Argentina
> > Tel/Fax: +54-(0)342-451.1594
> >
> >
>