or download this
>perl -le "$t1=time; for (1..$ARGV[0]) { delete $INC{'Carp.pm'}; delet
+e $INC{'Carp/Heavy.pm'}; require Carp; require Carp::Heavy; } $t2=tim
+e; print(($t2-$t1)/$ARGV[0])" 100000
0.00475
>perl -le "$t1=time; for (1..$ARGV[0]) { delete $INC{'Carp.pm'}; delet
+e $INC{'Carp/Heavy.pm'}; require Carp; require Carp::Heavy; } $t2=tim
+e; print(($t2-$t1)/$ARGV[0])" 100000
0.00474