GATE CS 2023 Q.27: CPU Scheduling

Which one or more of the following CPU scheduling algorithms can potentially cause starvation?

First-in First-Out

Round Robin

Priority Scheduling

Shortest Job First

Official answer and solution

About the official key

Official key accepted both (A, C, D) and (C, D).

Note on this question

Official key accepted both (A, C, D) and (C, D).

Solution

Identify CPU scheduling algorithms where a process can wait indefinitely without receiving CPU time.

Round Robin (RR): Allocates CPU in time slices cyclically to all ready processes, guaranteeing bounded waiting time and zero starvation.
Priority Scheduling: Low-priority processes may wait indefinitely if higher-priority processes continuously arrive in the ready queue. (Can cause starvation)
Shortest Job First (SJF): Long jobs may wait indefinitely if shorter jobs continuously arrive. (Can cause starvation)
First-in First-Out (FIFO): In standard operating system theory, FIFO serves processes in strict arrival order, so every process eventually runs (no starvation). However, in certain contexts or edge cases (such as infinite-looping jobs blocking the uniprocessor indefinitely), FIFO has been argued to starve subsequent processes. The official GATE answer key accepted both (C, D) and (A, C, D).

Final answer

Options (A, C, D) or (C, D)

Common trap

Overlooking that the official GATE key accepted both (A, C, D) and (C, D) due to ambiguity regarding non-terminating processes under FIFO.

The answer is the one in the official GATE answer key. The solution is this site's own explanation.

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