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 Dalc?n > > > > --------------- > > > > Centro Internacional de M?todos Computacionales en Ingenier?a (CIMEC) > > > > Instituto de Desarrollo Tecnol?gico para la Industria Qu?mica (INTEC) > > > > Consejo Nacional de Investigaciones Cient?ficas y T?cnicas (CONICET) > > > > PTLC - G?emes 3450, (3000) Santa Fe, Argentina > > > > Tel/Fax: +54-(0)342-451.1594 > > > > > > > > > > > > > > > > -- > > Lisandro Dalc?n > > --------------- > > Centro Internacional de M?todos Computacionales en Ingenier?a (CIMEC) > > Instituto de Desarrollo Tecnol?gico para la Industria Qu?mica (INTEC) > > Consejo Nacional de Investigaciones Cient?ficas y T?cnicas (CONICET) > > PTLC - G?emes 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 Dalc?n --------------- Centro Internacional de M?todos Computacionales en Ingenier?a (CIMEC) Instituto de Desarrollo Tecnol?gico para la Industria Qu?mica (INTEC) Consejo Nacional de Investigaciones Cient?ficas y T?cnicas (CONICET) PTLC - G?emes 3450, (3000) Santa Fe, Argentina Tel/Fax: +54-(0)342-451.1594