/*$Id: PetscMemcpy.c,v 1.16 2000/11/28 17:32:38 bsmith Exp bsmith $*/ #include "petsc.h" #undef __FUNC__ #define __FUNC__ "main" int main(int argc,char **argv) { PetscLogDouble x,y,z; int i,ierr; Scalar *A,*B; PetscInitialize(&argc,&argv,0,0); ierr = PetscMalloc(8000000*sizeof(Scalar),&( A )); ierr = PetscMalloc(8000000*sizeof(Scalar),&( B )); for (i=0; i<8000000; i++) { A[i] = i%61897; B[i] = i%61897; } /* To take care of paging effects */ ierr = PetscMemcpy(A,B,sizeof(Scalar)*0);CHKERRA(ierr); ierr = PetscGetTime(&x);CHKERRA(ierr); ierr = PetscGetTime(&x);CHKERRA(ierr); /* PetscMemcpy(A,B,sizeof(Scalar)*8000000); PetscMemcpy(A,B,sizeof(Scalar)*8000000); PetscMemcpy(A,B,sizeof(Scalar)*8000000); PetscMemcpy(A,B,sizeof(Scalar)*8000000); PetscMemcpy(A,B,sizeof(Scalar)*8000000); PetscMemcpy(A,B,sizeof(Scalar)*8000000); PetscMemcpy(A,B,sizeof(Scalar)*8000000); PetscMemcpy(A,B,sizeof(Scalar)*8000000); PetscMemcpy(A,B,sizeof(Scalar)*8000000); PetscMemcpy(A,B,sizeof(Scalar)*8000000); */ { int j; for (j = 0; j<10; j++) { for (i=0; i<8000000; i++) { B[i] = A[i]; } }} ierr = PetscGetTime(&y);CHKERRA(ierr); ierr = PetscMemcpy(A,B,sizeof(Scalar)*0);CHKERRA(ierr); ierr = PetscMemcpy(A,B,sizeof(Scalar)*0);CHKERRA(ierr); ierr = PetscMemcpy(A,B,sizeof(Scalar)*0);CHKERRA(ierr); ierr = PetscMemcpy(A,B,sizeof(Scalar)*0);CHKERRA(ierr); ierr = PetscMemcpy(A,B,sizeof(Scalar)*0);CHKERRA(ierr); ierr = PetscMemcpy(A,B,sizeof(Scalar)*0);CHKERRA(ierr); ierr = PetscMemcpy(A,B,sizeof(Scalar)*0);CHKERRA(ierr); ierr = PetscMemcpy(A,B,sizeof(Scalar)*0);CHKERRA(ierr); ierr = PetscMemcpy(A,B,sizeof(Scalar)*0);CHKERRA(ierr); ierr = PetscMemcpy(A,B,sizeof(Scalar)*0);CHKERRA(ierr); ierr = PetscGetTime(&z);CHKERRA(ierr); fprintf(stdout,"%s : \n","PetscMemcpy"); fprintf(stdout," %-11s : %e MB/s\n","Bandwidth",10.0*8*8/(y-x)); fprintf(stdout," %-11s : %e sec\n","Latency",(z-y)/10.0); fprintf(stdout," %-11s : %e sec\n","Per Scalar",(2*y-x-z)/8000000.0); PetscFinalize(); PetscFunctionReturn(0); }