How to prepare OS for the GATE | Operating System

Operating System - GATE CSE

Operating System is one of the important subjects having a 10% weightage of marks in the GATE CSE exam. If you score 100% in Operating System you will be scoring 10 marks from only one subject which is huge. The percentage of its share is varying over a period but is having a constant 10 % share from the last four years. Have a look over the distribution over the years:

Weightage in GATE CSE- OS

Before giving you details of the important and scoring topics of Operating Systems for GATE CSE, I will give you a piece of quick information about What Operating System is? This is for beginners only, if you know about it you can directly move to the "key steps" section.

Introduction

An Operating System (OS) is an interface between a computer user and computer hardware. An operating system is a software that performs all the basic tasks like file management, memory management, process management, handling input and output, and controlling peripheral devices such as disk drives and printers.

You are able to read this article because the Operating System in your system is working to create connections with the network and then making it readable using the XML and HTML document provided by the Server. You are on this blog that shows you have basic information about the subject, if not, click HERE.

Key Steps

I am dealing with competitive exams related to CSE since 2013 and I am in regular touch with these things. In my perspective, the best approach to master a particular subject goes like this

Cut Short the whole subject into specific topics that are important to understand and score well.
Learn all those topics from basic books
Learn short-cuts and theories to simplify the questions
Practice using previous year question banks or other booklets.

You will be done with the first step after reading this blog. I recommend these books to understand the basic concepts:

Reference Books

1. Operating System Concepts:8th Edition Wiley Student Edition Paperback

Authors: Abraham Silberschatz (Author), Peter Baer Galvin (Author), Greg Gagne (Author) Click HERE to buy.

2. Operating Systems: Internals and Design Principles, 7e

Author: William Stallings Click Here to buy.

Topics to be Covered

Important topics to be covered and their sub-topics are as under:

1.     Process State Diagram:
v Process States
v Dispatchers
v Schedulers
v Context Switching
v PCB
2.     Fork System Calls:
v Basic working
v Coding Questions
3.     Threads and Kernels
4.     Process Scheduling
v Various scheduling algorithms
v Turn Around Time (Numerical)
v Average Waiting Time(Numerical)
v Response Time
v Preemptive and Non Preemptive Approaches
5.     Deadlock
v Basic Concept
v All the 4 conditions for deadlock-free environment
v Safe State
v Banker's Algorithm (With examples)
v Deadlock avoidance
v Deadlock Prevention
6.     Process Synchronization
v Semaphores
v Counting and Binary Semaphores(with numerical)
v Peterson's Solution
v Test and set
v Counting Semaphores v/s Binary Semaphores
7.     Memory Management
v Best Fit, Worst Fit, First Fit
v MMU
v Fragmentation
v Internal and External Fragmentation
v Paging (Numericals)
v Segmentation
v Virtual Memory
v Page Faults (Numericals and different Approaches)
v TLB
8.     Disk Scheduling (with Numericals)
v FIFO
v C-LOOK
v C-SCAN
v SCAN
v LOOK
v SDF
9.     File Management and Security
v Indexing
v File Systems
10. UNIX/LINUX commands
v Important for UGC NET, ISRO, DRDO, and other competitive exams but not for GATE.