warn message in log summary

Lisandro Dalcin dalcinl at gmail.com
Mon Nov 26 16:56:38 CST 2007


On 11/26/07, Matthew Knepley <knepley at gmail.com> wrote:
> On Nov 26, 2007 4:19 PM, Lisandro Dalcin <dalcinl at gmail.com> > > After surfing the code and hacked PetscLogPrintSummary(),  I added a
> > check (eventInfo[event].depth == 0) in order to skip reductions of
> > time values for 'unterminated' events. This worked as expected, and
> > the even info did not show-up and the warning was not generated...
> >
> > Could this be a possible 'fix' for this issue??
>
> There is, but it is more painful than the disease. We would have to protect
> all SETERRQ() statements by freeing all resources (like events, memory, ...)
> This is huge job, and better handled by exception mechanisms.

Matt, not sure if you understood me.. I know that reworking PETSc
error management is not so easy... What I was asking is for skipping
at -log_summary time all those events that were not 'finalized', that
is, its 'depth' call is not zero... I believe this should fix the
issue with negative timmings... Or we perhaps could issue the real
warning, saying that some event was not properly finalized...


> >
> > > On Nov 26, 2007, at 11:03 AM, Lisandro Dalcin wrote:
> > >
> > > > I even get consistent time deltas using 'gettimeofday' on my box!!
> > > > Perhaps PETSc has some bug somewere?? What do you think??
> > > >
> > > > On 11/26/07, Richard Tran Mills <rmills at ornl.gov> wrote:
> > > >> Lisandro,
> > > >>
> > > >> Unfortunately, I see the same negative timings problem on the Cray
> > > >> XT3/4
> > > >> systems when I configure PETSc to use MPI_Wtime() for all its
> > > >> timings.  So
> > > >> that doesn't necessarily fix anything...
> > > >>
> > > >> --Richard
> > > >>
> > > >> Lisandro Dalcin wrote:
> > > >>
> > > >>> Perhaps PETSc should use MPI_Wtime as default timer. If a better one
> > > >>> is available, then use it. But then MPIUNI have to also provide an
> > > >>> useful, default implementation.
> > > >>>
> > > >>> Runing a simple test, like this (MPICH2):
> > > >>>
> > > >>> int main(void)
> > > >>> {
> > > >>>  int i;
> > > >>>  double t0[100],t1[100];
> > > >>>  MPI_Init(0,0);
> > > >>>  for (i=0; i<100; i++) {
> > > >>>    t0[i] = MPI_Wtime();
> > > >>>    t1[i] = MPI_Wtime();
> > > >>>  }
> > > >>>  for (i=0; i< 100; i++) {
> > > >>>    printf("t0=%e, t1=%e, dt=%e\n",t0[i],t1[i],t1[i]-t0[i]);
> > > >>>  }
> > > >>>  MPI_Finalize();
> > > >>>  return 0;
> > > >>> }
> > > >>>
> > > >>> and in the SAME box I get the PETSc warning, it consistently gives
> > > >>> me
> > > >>> positive time deltas of the order of MPI_Wtick()...
> > > >>
> > > >>
> > > >
> > > >
> > > > --
> > > > 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
> > > >
> > >
> > >
> >
> >
> > --
> > 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
> >
> >
>
>
>
> --
> What most experimenters take for granted before they begin their
> experiments is infinitely more interesting than any results to which
> their experiments lead.
> -- Norbert Wiener
>
>


-- 
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




More information about the petsc-dev mailing list