PetscPreLoadBegin#

Begin a segment of code that may be preloaded (run twice) to get accurate timings

Synopsis#

#include <petsclog.h>
void PetscPreLoadBegin(PetscBool  flag,char *name);

Not Collective

Input Parameters#

flag - PETSC_TRUE to run twice, PETSC_FALSE to run once, may be overridden with command line option -preload true or -preload false
name - name of first stage (lines of code timed separately with -log_view) to be preloaded

Usage#

     PetscPreLoadBegin(PETSC_TRUE,"first stage);
       lines of code
       PetscPreLoadStage("second stage");
       lines of code
     PetscPreLoadEnd();

Note#

Only works in C/C++, not Fortran

Flags available within the macro.

PetscPreLoadingUsed - true if we are or have done preloading
PetscPreLoadingOn - true if it is CURRENTLY doing preload
PetscPreLoadIt - 0 for the first computation (with preloading turned off it is only 0) 1 for the second
PetscPreLoadMax - number of times it will do the computation, only one when preloading is turned on The first two variables are available throughout the program, the second two only between the PetscPreLoadBegin() and PetscPreLoadEnd()