![]() |
Real Time Scheduling Algorithms → Rate Montonic(RM) |
Rate Montonic (RM) scheduling from Liu und Layland (1973) is probably the most well-known scheduling
algorithm for independent periodic tasks. Rate monotonic scheduling is based on the
following assumption:
The right hand side is about 0.7 for large n:
Equation 1:
Equation 1 requires that some of the computing power of the processor is not used in order to make
sure that all requests are honored in time. If the above six RM-assumptions are met, all deadlines
will be met.
RM scheduling is a preemptive
scheduling policy with fixed priorities. The priority of tasks is a monotonically
decreasing function of their period. In other words, tasks with a short period will get a high priority
and tasks with a long period will be assigned a low priority. During the scheduling the tasks will
be executed according to their priorities. That means, the currently
executed task will be interrupted, if its period is longer than the period of a new arriving task.
Introduction > Real Time Scheduling Algorithms
> Rate Montonic(RM)
Back | Next |