Preemption – GATE 1996 – Previous year gate question paper of Operating System.
Preemption – GATE 1996 – Previous year gate question paper of Operating System.
In the GATE 1996 examination, a question related to process state transitions was presented, focusing on preemption in operating systems.
Question:
The process state transition diagram in Figure 1.8 is representative of:
a. a batch operating system
b. an operating system with a preemptive scheduler
c. an operating system with a non-preemptive scheduler
d. a uni-programmed operating system
Note: The diagram referred to in the question illustrates a transition from the “Running” state to the “Ready” state.
Answer:
The correct answer is b. an operating system with a preemptive scheduler.
Explanation:
In operating systems, a preemptive scheduler allows the operating system to interrupt a currently running process and move it back to the Ready state. This transition occurs to allocate CPU time to another process, ensuring efficient and fair utilization of the CPU among all processes. The ability to preempt a running process is a hallmark of preemptive scheduling.
Conversely, in a non-preemptive scheduler, once a process starts its execution, it runs to completion or until it voluntarily yields control, such as waiting for I/O operations. There is no mechanism to forcibly move a running process back to the Ready state in non-preemptive scheduling.
Reference:
This question and its solution are discussed in detail on GATE Overflow:
Understanding the distinction between preemptive and non-preemptive scheduling is crucial for grasping how modern operating systems manage process execution and CPU allocation.
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