Consider a system using preemptive priority scheduling with multiple real-time and user-level processes. Priority inheritance protocol is implemented.

I. Priority inversion can occur when a low-priority process holds a resource that a high-priority process needs.
II. Under priority inheritance, the low-priority process temporarily inherits the higher priority to avoid blocking.
III. Priority inversion can be completely avoided if all processes are scheduled in a round-robin fashion.
IV. Starvation may still occur for low-priority processes even with priority inheritance.

Which of the statements are correct?

Question

Consider a system using preemptive priority scheduling with multiple real-time and user-level processes. Priority inheritance protocol is implemented.

I. Priority inversion can occur when a low-priority process holds a resource that a high-priority process needs.

II. Under priority inheritance, the low-priority process temporarily inherits the higher priority to avoid blocking.

III. Priority inversion can be completely avoided if all processes are scheduled in a round-robin fashion.

IV. Starvation may still occur for low-priority processes even with priority inheritance.

Which of the statements are correct?

Quintessence Classes · Accepted Answer

The correct answer is I, II and IV only. Understanding Priority InversionImagine three processes: High (H), Medium (M), and Low (L).L acquires a lock on a shared resource (e.g., a printer).H arrives and needs that resource, so it must wait for L.M arrives. Since M has a higher priority than L, it preempts L and starts running.H is now waiting for L, but L cannot finish because M is running. Effectively, a Medium-priority task is blocking a High-priority task. This is the "Inversion."The Priority Inheritance SolutionUnder PIP, as soon as H starts waiting for the resource held by L, the system boosts L's priority to match H. This prevents M from preempting L, allowing L to finish its work quickly and release the resource to H.

Answer

I and II only

Answer

II and III only

Answer

II and IV only

Answer & Explanation

About this question

JKSSB Jr. Assistant 2026 Written

Details

Practice 1,142+ more PYQs interactively