#!/usr/bin/perl

use Time::HiRes qw(time sleep);

my $load = shift @ARGV;
my $sleep = 0.01;

$| = 1;

my @t = times;
my @last = [time, $t[0] + $t[1]];

while (1) {
    @t = times;
    unshift @last, [time, $t[0] + $t[1]];
    pop @last if @last > 100;
    my $current = 100 * ($last[0][1]-$last[-1][1])/ (0.00001 + $last[0][0]-$last[-1][0]);
    if ($current > $load) {
        sleep $sleep;
    }
    else {
        while (time < $last[0][0] + $sleep) {
            for (1..10000) { 1; }
        }
    }
}