The process scheduler in the Linux kernel 2.4 performs scheduling based on CPU billing gathered from periodic process sampling ticks, which allows local users…

The process scheduler in the Linux kernel 2.4 performs scheduling based on CPU billing gathered from periodic process sampling ticks, which allows local users to cause a denial of service (CPU consumption) by performing voluntary nanosecond sleeps that result in the process not being active during a clock interrupt, as described in "Secretly Monopolizing the CPU Without Superuser Privileges."