Important topics:
Explain Operating System in layman terms
Types of OS - Batch OS, Multiprogramming OS, Multitasking OS, Time Sharing OS, Distributed
OS, Real Time OS
RAM vs ROM + Types (Asked in DE Shaw)
Virtualization vs Containerization (OR Virtual machine vs Docker)
Program vs Process (Asked in DE Shaw)
Process vs Thread
User-level thread vs kernel level thread
Differences between multi-threading, multi-processing, multiprogramming, multi-tasking
Microservices based architecture
Process scheduling - Basic terminology like scheduling queue, different times in process like
arrival time, Completion Time, Burst Time, Turn Around Time, Waiting Time (WT)
Different process scheduling algorithms - FCFS, SJF, SRTF etc.
Different criterias used - CPU utilization, throughput, response time etc.
Explain how does a process gets executed inside memory (Asked in DE Shaw)
Optimal number of threads for a process
Preemptive vs Non-preemptive scheduling
Some important terms associated with scheduling algorithms - Problem of Ageing, Starvation,
Deadlock [should know basic definitions at least]
Synchronization - Semaphores, mutex vs counting semaphore, critical section problem + their
three conditions (Mutual exclusion, Progress, Bounded waiting)
Deadlock : Basic definition, Necessary conditions, handling techniques
Memory Management [Very IMP]: Primary vs Secondary Memory, memory Allocation while
running a process [IMP], Paging and segmentation (Basics should be clear)
Thrashing [IMP concept]
What is Cache and why is it used?
Memory Partitioning
What is Virtual memory and why?
LRU Cache implementation
Also, practice standard interview questions from:
Interview questions:
https://www.geeksforgeeks.org/commonly-asked-operating-systems-interview-questions-set-1/
https://www.interviewbit.com/operating-system-interview-questions/
Other questions for practice: https://www.javatpoint.com/operating-system-interview-questions
Revision:
https://www.geeksforgeeks.org/last-minute-notes-operating-systems/
Book (if enough time):
Operating System Principles by Galvin: https://amzn.to/2UuxwEJ