09-04-2013, 04:28 PM
UNIPROCESSOR SCHEDULING ALGORITHM AND MULTIPROCESSOR SCHEDULING ALGORITHM
UNIPROCESSOR SCHEDULING.ppt (Size: 135.5 KB / Downloads: 24)
UNIPROCESSOR SCHEDULING ALGORITHM
Uniprocessor scheduling means a set of tasks on a single processor. Uniprocessor scheduling is part of the process of developing a multiprocessor schedule.
UNIPROCESSOR SCHEDULING ALGORITHMS
Traditional rate-monotonic (RM)
Rate-monotonic deferred server (DS)
Earliest deadline first (EDF)
Precedence and exclusion conditions
Multiple task versions
TRADITIONAL RATE-MONOTONIC (RM)
The task set consist of periodic,prempitable tasks whose deadlines equal to the task period. It handle the peridic tasks.
A task set of n task is schedulable under RM if its total processor utilization is no greater than
n(21/n -1).
Task priorities are static.
PRECEDENCE AND EXCLUSION CONDITIONS
The tasks are independent and are always preemptible by other tasks which are presented in precedence condition.
The algorithm with exclusion condition i.e certain tasks are not allowed to interrupt certain other tasks, irrespective of priority.
UTILIZATION BALANCING ALGORITHM
This algorithm assign tasks to processors one by one in such a way that at the end of each step, the utilization of the various processors are as nearly balanced as possible.
The tasks are assumed to be preemptible.
FOCUSED ADDRESSING AND BIDDING ALGORITHM
The tasks are assumed to arrive at the individual processors. The processor offload some of its workload onto other processors when it is unable to meet the deadline of other constraints of its tasks.
It does so by announcing which tasks it would like to offload and waiting for the other processors to offer to take them up.