# OS Unit 3 – CPU Scheduling

On this page, you will find all the most important and most asked questions from unit 3 of the Operating subject.

## Topic : Intro to DST (Key Note and Questions)

### Key Note:

• Data Structure is a way to organize data so that we can perform any operation on it efficiently.
• Data type describes which type of value a variable can store. Means if a variable is of int data type it means that, that particular variable can store only integer data.
• Built-in data type is also known as predefined data type which can be directly used by any programmer to a variable types and assign value in it.
• Some example of built-in data type are int, char, float, double, short, long etc.

### Questions

1. What are the criteria of CPU Scheduling algorithms?
2. Explain the preemptive and non-premptive scheduling algorithm.
3. Write the various CPU Scheduling algorithm.

## Topic : Algorithm (Key Note and Questions)

### Key Note:

• Algorithm can be defined as a step by step approach  to solve a problem in finite steps and time. It is a human-readable solution.
• Efficiency of an Algorithm shows the quality of algorithm. Here the parameter for quality is algorithm should take less time and space to solve any problem.
• Time complexity shows time taken by an algorithm to solve a problem.
• Space complexity show space/memory taken by an algorithm to solve a problem.

### Key Note:

• Asymptotic notation helps to measure the complexity of an algorithm. It is of 5 types Big-Oh, Omega, Theta, Little Oh and Little Omega.
• An Abstract datatype is a datatype, whose behavior is defined by a set of values and set of operations. for example stack and queue is a perfect example of ADT.
1. Discuss the multilevel queue scheduling algorithm. Write its advantage and disadvantage.
2. Discuss the multilevel feedback queue scheduling algorithm. Write its advantage and disadvantage.
3. What is deadlock? Explain with the help of example.
4. Write the necessary condition for deadlock.
5. What do you understand by resource allocation graph. Explain with suitable diagram.
6. How you can prevent the deadlock.
7. What do you understand by deadlock avoidance?
8. Explain the banker’s algorithm for avoiding deadlock.
9. What do you understand by starvation?
10. Write the difference between deadlock and starvation.