Operating system concepts-3

Name: Operating system concepts-3
Rating: 4.9 (17 reviews)

Master the basics of Operating System memory management, virtual memory, page replacement, thrashing from scratch.

Created byAditya Mishra (Ph.D.)

Last updated 3/2023

English

What you'll learn

Memory management terminology
Where do memory addresses come from?
What are the required memory management properties?
What are some simple memory allocation schemes?
What is fragmentation? (Internal, external fragmentation.)
What is paging?
What is the key idea behind paging?
How paging works?
How is address translation done with paging?
How does paging hardware work?
How is memory address translated by the paging hardware?
How do memory management systems perform address translation without division?
How to make paging efficient?
What is TLB cache?
How does TLB cache work?
What are the performance implications of a TLB cache?
How is the main memory initialized when a process is started?
How context switches are performed in presence of paging?
How does paging facilitate memory sharing?
What is demand paging?
How does demand paging work?
When to load a page in demand paging?
How is demand paging implemented?
What is swap space?
What are the performance implications of demand paging?
How is TLB cache updated with demand paging?
What are page replacement algorithms?
What is FIFO page replacement?
What is MIN page replacement?
What is Random page replacement?
What is LRU page replacement?
What is Belady's anomaly?
What is thrashing?
How to limit thrashing?
What is working set?

Course content

9 sections • 51 lectures • 3h 33m total length

Course introduction1:36
Aditya introduces memory management in operating systems, covering paging, address translation, caches to make paging efficient, demand paging, page replacement algorithms, and thrashing.
Memory management terminology6:52
Explore memory management concepts by examining how processes address and occupy RAM, including segments, physical versus virtual addresses, and the translation between them.
Where do addresses come from?5:24
We explore three ways addresses are generated: compile-time generation of virtual addresses, load-time mapping to physical memory by the loader, and run-time translation from virtual to physical addresses.
Required memory management properties2:22
Simple memory allocation schemes3:59
Memory allocation and fragmentation5:08
Fragmentation heuristics1:32
Quiz 1

Paging idea2:01
Paging - motivation and features I2:31
Paging - motivation and features II4:09
Learn how paging uses fixed 4 kilobyte pages and frames to eliminate external fragmentation, while internal fragmentation arises from an unused portion of the last page.
Paging - example3:37
Demonstrate how paging maps process pages to noncontinuous main memory frames using a page table and base table to translate virtual addresses into physical addresses.
Paging - address translation1:59
Paging hardware3:33
Paging hardware - address translation2:19
Paging hardware - practical details4:09
Quiz 2

Demand paging key ideas4:23
Explore how demand paging uses the hard disk as an extension of main memory, loading only needed pages into RAM via page tables to enable virtual memory and higher multiprogramming.
Demand paging details4:52
Demand paging example3:33
When to load a page I?3:58
Compare start-time loading and overlays for page management, highlighting effects on page faults, memory limits, and real-time guarantees in embedded systems.
When to load a page II?6:29
Explore pure demand paging, where the OS loads pages from disk into RAM only when referenced, triggering page faults and traps, and examine pre paging as a predictor with risks.
Implementation of demand paging5:21
Learn demand paging: the page table stores frame numbers and a valid bit for memory residency. On a page fault, the OS loads page from disk and updates its table.
Swap space3:52
Demand paging performance6:30
Demand paging - updating the TLB4:43
Quiz 6

Page replacement algorithms - FIFO3:10
Page replacement algorithms - MIN3:19
Page replacement algorithms - Random1:18
Page replacement algorithms - LRU3:19
Understand how the least recently used eviction policy guides page replacement by evicting the oldest data not accessed for the longest time, and why LRU approximates the min-optimal policy.
FIFO page replacement example5:03
MIN page replacement example3:50
LRU page replacement example3:52
Apply the least recently used page eviction policy to a toy memory example, illustrating faults, hits, and frame updates as pages are evicted and loaded.
Quiz 7

Thrashing4:38
Explore thrashing in virtual memory, where caching and page faults force eviction due to a working set that cannot fit in main memory, hurting CPU utilization in multi programming environments.
How to limit thrashing?4:02
Working set example3:47
Using page fault rate to prevent thrashing3:14
Track page fault frequency per process to prevent thrashing; adjust frames with upper and lower thresholds, and suspend processes when memory is full to balance system-wide page faults.
Demand paging summary2:07
Demand paging enables virtual memory by letting the address space exceed physical memory and loading only parts the CPU needs, enabling library sharing and reducing page faults and context-switch costs.
Quiz 9

Requirements

No previous knowledge about operating systems needed. Everything you need to know about the topics will be covered.

Description

Ace operating systems (OS) memory management, paging, virtual memory, page replacement, thrashing, working set questions in competitive exams, job interviews, and OS course exams.

Do you know: How the OS presents an illusion of infinite memory to users? How can the OS execute processes much bigger than the RAM (main memory)? Where do memory addresses come from? How does OS keep several processes inside the RAM for execution? How OS makes room for new processes when the RAM is full? What happens if there are too many processes in the RAM? Learn the explanations to these and many more intriguing questions in this course!

Specifically, the course will cover the following in detail.

Memory management terminology
Where do memory addresses come from?
What are the required memory management properties?
What are some simple memory allocation schemes?
What is fragmentation?
What is internal fragmentation?
What is external fragmentation?
What is paging?
What is the key idea behind paging?
How paging works?
How is address translation done with paging?
How does paging hardware work?
How is memory address translated by the paging hardware?
How do memory management systems perform address translation without division?
How to make paging efficient?
What is TLB cache?
How does TLB cache work?
What are the performance implications of a TLB cache?
How is the main memory initialized when a process is started?
How context switches are performed in presence of paging?
How does paging facilitate memory sharing?
What is demand paging?
How does demand paging work?
When to load a page in demand paging?
How is demand paging implemented?
What is swap space?
What are the performance implications of demand paging?
How is TLB cache updated with demand paging?
What are page replacement algorithms?
What is FIFO page replacement?
What is MIN page replacement?
What is Random page replacement?
What is LRU page replacement?
What is Belady's anomaly?
What is thrashing?
How to limit thrashing?
What is working set?

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Who this course is for:

Anyone interested in learning about operating systems in modern computers could benefit from this course.
Computer science undergraduate students taking an operating systems course could benefit from the course.

Operating system concepts-3

What you'll learn

Explore related topics

Course content

Introduction7 lectures • 27min

Paging8 lectures • 24min

Address translation3 lectures • 14min

How to make paging efficient?5 lectures • 22min

Processes and paging3 lectures • 18min

Demand paging9 lectures • 44min

Page replacement algorithms7 lectures • 24min

Unusual scenarios for page replacement algorithms4 lectures • 23min

Thrashing5 lectures • 18min

Requirements

Description

Who this course is for: