xref: /petsc/src/benchmarks/PetscMemzero.c (revision 40badf4fbc550ac1f60bd080eaff6de6d55b946d)
1 
2 #include <petscsys.h>
3 #include <petsctime.h>
4 
5 int main(int argc,char **argv)
6 {
7   PetscLogDouble x,y,z;
8   PetscScalar    A[10000];
9   PetscErrorCode ierr;
10 
11   ierr = PetscInitialize(&argc,&argv,0,0);if (ierr) return ierr;
12   /* To take care of paging effects */
13   CHKERRQ(PetscMemzero(A,sizeof(PetscScalar)*0));
14   CHKERRQ(PetscTime(&x));
15 
16   CHKERRQ(PetscTime(&x));
17   CHKERRQ(PetscMemzero(A,sizeof(PetscScalar)*10000));
18   CHKERRQ(PetscMemzero(A,sizeof(PetscScalar)*10000));
19   CHKERRQ(PetscMemzero(A,sizeof(PetscScalar)*10000));
20   CHKERRQ(PetscMemzero(A,sizeof(PetscScalar)*10000));
21   CHKERRQ(PetscMemzero(A,sizeof(PetscScalar)*10000));
22   CHKERRQ(PetscMemzero(A,sizeof(PetscScalar)*10000));
23   CHKERRQ(PetscMemzero(A,sizeof(PetscScalar)*10000));
24   CHKERRQ(PetscMemzero(A,sizeof(PetscScalar)*10000));
25   CHKERRQ(PetscMemzero(A,sizeof(PetscScalar)*10000));
26   CHKERRQ(PetscMemzero(A,sizeof(PetscScalar)*10000));
27   CHKERRQ(PetscTime(&y));
28   CHKERRQ(PetscMemzero(A,sizeof(PetscScalar)*0));
29   CHKERRQ(PetscMemzero(A,sizeof(PetscScalar)*0));
30   CHKERRQ(PetscMemzero(A,sizeof(PetscScalar)*0));
31   CHKERRQ(PetscMemzero(A,sizeof(PetscScalar)*0));
32   CHKERRQ(PetscMemzero(A,sizeof(PetscScalar)*0));
33   CHKERRQ(PetscMemzero(A,sizeof(PetscScalar)*0));
34   CHKERRQ(PetscMemzero(A,sizeof(PetscScalar)*0));
35   CHKERRQ(PetscMemzero(A,sizeof(PetscScalar)*0));
36   CHKERRQ(PetscMemzero(A,sizeof(PetscScalar)*0));
37   CHKERRQ(PetscMemzero(A,sizeof(PetscScalar)*0));
38   CHKERRQ(PetscTime(&z));
39 
40   fprintf(stdout,"%s : \n","PetscMemzero");
41   fprintf(stdout,"    %-15s : %e sec\n","Latency",(z-y)/10.0);
42   fprintf(stdout,"    %-15s : %e sec\n","Per PetscScalar",(2*y-x-z)/100000.0);
43 
44   ierr = PetscFinalize();
45   return ierr;
46 }
47