Preemptive Vs Non preemptive Scheduling

The Scheduling algorithms can be divided into two category with respect to how they contract with clock interrupt:-

Non preemptive Scheduling:- 

A scheduling regulation is non preemptive if, once a process has been given the CPU, the CPU cannot be taken away from that process.

Following are some characteristics of non preemptive scheduling:-

• In non preemptive system, short jobs are made to wait by longer jobs but the overall action of all processes is fair.
• In non preemptive system, response times are extra predictable because incoming high priority jobs can not displace waiting jobs.
• In non preemptive scheduling, a scheduler executes jobs in the follow two situations.
• When a process switches from running state to the waiting state.
• When a process terminate. 

Preemptive Scheduling:-

A scheduling regulation is preemptive if, once a process has been given the CPU can taken away.

The plan of allowing processes that are logically run-able to be temporarily balanced is called Preemptive Scheduling and it is contrast to the "run to completion" method.