Intermediate Topic 31 of 51 Operating Systems
Page Replacement Algorithms
Policies such as FIFO, LRU and Clock for choosing victims.
How it works
When memory is full the OS evicts a page: FIFO (suffers Belady's anomaly), optimal (evict the page needed furthest in the future; benchmark only), LRU, and Clock which approximates LRU with a reference bit.
Where it is used
Tuning memory behavior.
Common pitfall
True LRU is costly, hence approximations.
Where it fits in the course
Page Replacement Algorithms is topic 31 of 51 in Operating Systems, rated Intermediate. It follows Page Faults. The next topic is Thrashing.
Practice and explore
- Open the interactive lesson, with a mini quiz.
- Take the Operating Systems quiz.
How to study this topic
- Read the explanation above and restate the definition in your own words.
- Open the interactive lesson and answer its mini quiz.
- Read the common pitfall, then write a short example that avoids it.
- Check your understanding in the Operating Systems quiz, and revisit the topic if you miss a question.
Frequently asked questions
What is Page Replacement Algorithms?
Policies such as FIFO, LRU and Clock for choosing victims. It belongs to Operating Systems and is an intermediate-level topic.
Where do people use Page Replacement Algorithms?
Tuning memory behavior.
What is the most common mistake with Page Replacement Algorithms?
True LRU is costly, hence approximations.
What should I learn before this topic?
Start with Page Faults, the topic just before it in Operating Systems.
How can I practice it?
Answer the mini quiz in the interactive lesson, then take the Operating Systems quiz.
Is Page Replacement Algorithms hard to learn?
It is an Intermediate topic. Be comfortable with the Beginner topics in this area first, then read the common pitfall carefully, since it is where most mistakes happen.
How long does it take to learn Page Replacement Algorithms?
Most learners can read the explanation and finish the interactive lesson in under an hour. Fluency comes from applying the idea, so plan a few short practice sessions with the quiz.
Which topics are related to Page Replacement Algorithms?
Page Faults, Thrashing, Virtual Memory are closely connected. The full list is in the related topics section of this page.
What should I study after Page Replacement Algorithms?
Continue with Thrashing, the next topic in Operating Systems.
Related topics
- Page Faults (Operating Systems)
- Thrashing (Operating Systems)
- Virtual Memory (Operating Systems)
- Memory Allocation (Operating Systems)
- Line Drawing Algorithms (Graphics, Vision & Media)
- Load Balancing Algorithms (Distributed Systems & Cloud)
- Greedy Algorithms (Algorithms)