>perl -le "$t1=time; for (1..$ARGV[0]) { delete $INC{'Carp.pm'}; require Carp; } $t2=time; print(($t2-$t1)/$ARGV[0])" 100000
0.00134

>perl -le "$t1=time; for (1..$ARGV[0]) { delete $INC{'Carp.pm'}; require Carp; } $t2=time; print(($t2-$t1)/$ARGV[0])" 100000
0.00134

>perl -le "$t1=time; for (1..$ARGV[0]) { delete $INC{'Carp.pm'}; require Carp; } $t2=time; print(($t2-$t1)/$ARGV[0])" 100000
0.00134