CPU Scheduling

By : Manglika Tripathi

Updated : Feb 27, 2021, 4:22

Scheduling is a term used for the selection of processes by the operating system, which are saved in the main memory and are ready to be performed. The CPU then controls these processes, and the whole chain is known as CPU scheduling. CPU scheduling is an essential topic for every engineering competitive examination. In layman's terms, the CPU controls the selected processes so that functions can be executed. Generally, many theoretical questions are asked from the sub-topics and types related to CPU scheduling. This article will tell you where to go for CPU scheduling study material for GATE CS, CPU scheduling GATE questions and answers pdf, CPU scheduling online quizzes, CPU scheduling topics for GATE CS, CPU scheduling notes for GATE pdf, and CPU scheduling online tests.

Important CPU Scheduling Topics for GATE CE



CPU scheduling criteria

Different CPU scheduling algorithms can be compared on the basis of the following criteria:

  • The utilisation of CPU.
  • The number of processes completed by the CPU in the given time.
  • Time taken to complete the whole process.
  • Time spent by the processes waiting in the queue.
  • Time taken to produce the first process.

FCFS CPU scheduling

In FCFS or first come first serve CPU scheduling method, processes that are first in the line for CPU, are assigned the CPU first.

Ostrich strategy

The shortest job first CPU scheduling method involves assigning the CPU first to those processes which have lesser tasks compared to others.

Priority scheduling

In priority scheduling methods, a CPU is assigned to those processes which have higher priority than other processes. In the case of equal priority, CPU is allocated on the FCFS basis.

Round robin scheduling

When preemption is added to the FCFS basis, then the scheduling is known as round-robin scheduling. Preemption helps the CPU in switching between the processes.

Multilevel queue scheduling

When the processes are divided into different groups for the purpose of saturation, it is known as multilevel queue scheduling. Groups are made about the properties of the processes like memory, priority, process types, etc.

Tips to Solve CPU Scheduling Questions in GATE CS

Following are some tips to keep in mind while preparing for questions on CPU scheduling:

  • There are many numericals, types, and subtopics involved in CPU scheduling, so practice as much as possible to solve questions faster in the examination.
  • CPU scheduling is a topic for which reference books are critical as they are updated with new material that is usually tested in examinations. So, choose CPU scheduling books very wisely.
  • The weightage of CPU scheduling topics is high in the GATE CS examination, so do not leave out any subtopic or portion from this topic, especially.
  • Practice with the help of tables and diagrams, especially in scheduling numerical, as it will help you understand problems easily and score well.

Importance of CPU scheduling in the GATE Exam

Here's why CPU scheduling forms an essential part of GATE:

  • CPU scheduling is one of the most important components of engineering examinations, as every year, these examinations include a lot of questions on CPU scheduling topics.
  • The weightage of CPU scheduling in the GATE CS examination is one of the highest every year, so practising it will help you score well.
  • Around 14 questions are asked every year on topics related to CPU scheduling in the GATE CS.
  • In last year's GATE CS examination, CPU scheduling and related sub-topics were tested for around 24 marks.

Most Recommended Books for CPU Scheduling for GATE

There are many books to prepare for CPU scheduling and related sub-topics for the GATE CS examinations, so you have to choose wisely. The following list of CPU scheduling books will help you get a thorough understanding of the possible CPU scheduling GATE questions:



Operating Systems Concepts

Avi Silberschatz, Greg Gagne, and Peter Baer Galvin

Modern Operating Systems

Andrew S. Tanenbaum

Operating Systems: Three Easy Pieces

Andrea C. Arpaci Dusseau and Remzi Arpaci Dusseau

Why prepare CPU Scheduling from BYJU'S Exam Prep?

Gradeup provides a friendly environment for students to interact, communicate, and address their queries. It also provides students with an environment to study using high-quality, verified examination material and practice previous years' examination papers, too. BYJU'S Exam Prep gives students access to verified study preparation material, which boosts aspirants' confidence. It also provides students with mock tests and regular live sessions to clarify doubts. You can also find CPU scheduling quizzes, CPU scheduling GATE notes, and CPU scheduling GATE syllabus to prepare for examinations on BYJU'S Exam Prep. Moreover, you also get a detailed solution for every question on BYJU'S Exam Prep.


Q. What is the weightage of CPU scheduling questions in competitive examinations?

On average, around 14 questions are asked on CPU scheduling and related topics in competitive examinations.

Q. What is the updated CPU scheduling syllabus for GATE CS?

You can find the updated CPU scheduling syllabus for GATE and CPU scheduling notes for CS on the BYJU'S Exam Prep website.

Q. How are CPU scheduling questions asked in competitive examinations?

They are usually asked in the form of numerical and theoretical MCQs. You can prepare accordingly with the CPU scheduling MCQ questions and CPU scheduling MCQ pdfs compiled by BYJU'S Exam Prep.

Q. What is the difficulty level of CPU scheduling questions in examinations?

The difficulty level of these questions is high, but if you have a clear understanding of the types and numericals, you can easily solve them