Question

Which of the following statement(s) is/are correct in the context of CPU scheduling?

• A. Turnaround time includes waiting time.
• B. The goal is to only maximize CPU utilization and minimize throughput.
• C. Round-robin policy can be used even when the CPU time required by each of the processes is not known \emph{a priori}.
• D. Implementing preemptive scheduling needs hardware support.

Hint:

Preemptive scheduling relies on timer interrupts, while round-robin works without knowing burst times.

Answer 1

The Correct Option is A, C, D

Step 1: Turnaround time.
Turnaround time is defined as the total time taken from process submission to completion. It includes waiting time, execution time, and any I/O delays. Hence, statement (A) is correct.

Step 2: Scheduling goals.
The goals of CPU scheduling include maximizing CPU utilization and throughput, while minimizing waiting time, turnaround time, and response time. Statement (B) is incorrect.

Step 3: Round-robin scheduling.
Round-robin scheduling does not require prior knowledge of CPU burst times, as each process is given a fixed time quantum. Therefore, statement (C) is correct.

Step 4: Preemptive scheduling.
Preemptive scheduling requires hardware support such as timer interrupts to regain control of the CPU. Hence, statement (D) is correct.