2: #include <petscsys.h>
  3: #include <petsctime.h>

  7: int main(int argc,char **argv)
  8: {
  9:   PetscLogDouble x,y,z;
 10:   int            i,ierr;
 11:   PetscScalar    *A,*B;

 13:   PetscInitialize(&argc,&argv,0,0);

 15:   PetscMalloc1(8000000,&A);
 16:   PetscMalloc1(8000000,&B);

 18:   for (i=0; i<8000000; i++) {
 19:     A[i] = i%61897;
 20:     B[i] = i%61897;
 21:   }
 22:   /* To take care of paging effects */
 23:   PetscMemcpy(A,B,sizeof(PetscScalar)*0);
 24:   PetscTime(&x);

 26:   PetscTime(&x);
 27:   /*
 28:   PetscMemcpy(A,B,sizeof(PetscScalar)*8000000);
 29:   PetscMemcpy(A,B,sizeof(PetscScalar)*8000000);
 30:   PetscMemcpy(A,B,sizeof(PetscScalar)*8000000);
 31:   PetscMemcpy(A,B,sizeof(PetscScalar)*8000000);
 32:   PetscMemcpy(A,B,sizeof(PetscScalar)*8000000);
 33:   PetscMemcpy(A,B,sizeof(PetscScalar)*8000000);
 34:   PetscMemcpy(A,B,sizeof(PetscScalar)*8000000);
 35:   PetscMemcpy(A,B,sizeof(PetscScalar)*8000000);
 36:   PetscMemcpy(A,B,sizeof(PetscScalar)*8000000);
 37:   PetscMemcpy(A,B,sizeof(PetscScalar)*8000000); */
 38:   { int j;
 39:     for (j = 0; j<10; j++)
 40:       for (i=0; i<8000000; i++) B[i] = A[i];}

 42:   PetscTime(&y);
 43:   PetscMemcpy(A,B,sizeof(PetscScalar)*0);
 44:   PetscMemcpy(A,B,sizeof(PetscScalar)*0);
 45:   PetscMemcpy(A,B,sizeof(PetscScalar)*0);
 46:   PetscMemcpy(A,B,sizeof(PetscScalar)*0);
 47:   PetscMemcpy(A,B,sizeof(PetscScalar)*0);
 48:   PetscMemcpy(A,B,sizeof(PetscScalar)*0);
 49:   PetscMemcpy(A,B,sizeof(PetscScalar)*0);
 50:   PetscMemcpy(A,B,sizeof(PetscScalar)*0);
 51:   PetscMemcpy(A,B,sizeof(PetscScalar)*0);
 52:   PetscMemcpy(A,B,sizeof(PetscScalar)*0);
 53:   PetscTime(&z);

 55:   fprintf(stdout,"%s : \n","PetscMemcpy");
 56:   fprintf(stdout,"    %-15s : %e MB/s\n","Bandwidth",10.0*8*8/(y-x));
 57:   fprintf(stdout,"    %-15s : %e sec\n","Latency",(z-y)/10.0);
 58:   fprintf(stdout,"    %-15s : %e sec\n","Per PetscScalar",(2*y-x-z)/8000000.0);

 60:   PetscFree(A);
 61:   PetscFree(B);
 62:   PetscFinalize();
 63:   return(0);
 64: }