Intermediate Topic 30 of 51 Operating Systems
Page Faults
Traps when a needed page is not resident in memory.
How it works
A page fault is raised when a page is not in memory: the OS finds it on disk, loads it into a frame (evicting another if needed), updates the page table and restarts the instruction. A disk fault costs milliseconds.
Where it is used
Demand paging, copy-on-write, lazy allocation.
Common pitfall
Access to unmapped addresses is a segmentation fault, not a recoverable fault.
Where it fits in the course
Page Faults is topic 30 of 51 in Operating Systems, rated Intermediate. It follows Virtual Memory. The next topic is Page Replacement Algorithms.
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 Faults?
Traps when a needed page is not resident in memory. It belongs to Operating Systems and is an intermediate-level topic.
Where do people use Page Faults?
Demand paging, copy-on-write, lazy allocation.
What is the most common mistake with Page Faults?
Access to unmapped addresses is a segmentation fault, not a recoverable fault.
What should I learn before this topic?
Start with Virtual Memory, 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 Faults 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 Faults?
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 Faults?
Virtual Memory, Page Replacement Algorithms, Segmentation are closely connected. The full list is in the related topics section of this page.
What should I study after Page Faults?
Continue with Page Replacement Algorithms, the next topic in Operating Systems.
Related topics
- Virtual Memory (Operating Systems)
- Page Replacement Algorithms (Operating Systems)
- Segmentation (Operating Systems)
- Thrashing (Operating Systems)
- Single Page Applications (Web Development)