OS - CPU Scheduling

Which of the following best describes Preemptive Scheduling?

• • The CPU executes a process until it finishes or waits for I/O.

• • The CPU executes a process only if it is the shortest.

• The CPU can interrupt a running process to start another.

• The CPU gives priority to user-level threads.

In a non-preemptive Shortest Process First (SPF) Algorithm, what is considered a major drawback?

• It is too complex to implement.

• It uses more CPU time compared to other algorithms.

• Long processes might starve if short ones keep arriving.

• It doesn’t handle I/O operations effectively.

The Round Robin scheduling algorithm ensures that every process gets an equal time slice for execution.

• True

• False

In the Priority Scheduling algorithm, a low-priority process might never get a turn to execute if high-priority tasks keep arriving.

• True

• False

The Dispatcher in CPU scheduling is responsible for determining which process should be executed next.

• True

• False

Consider three processes with the following burst times: P1 = 5ms, P2 = 8ms, and P3 = 12ms. If the processes are scheduled using the First-Come, First-Served (FCFS) algorithm, calculate the average waiting time.

• 3 ms

• 10 ms

• 6 ms

• 2 ms

Calculate the Average Waiting Time Using Shortest Job First (SJF) Algorithm:

Consider three processes with the following burst times: P1 = 6ms, P2 = 2ms, and P3 = 8ms. If the processes are scheduled using the Shortest Job First (SJF) algorithm, calculate the average waiting time.

• 3.29

• 3.31 ms

• 3.33 ms

• 10.0 ms