Virtual memory and system performance

The central question

What happens when the pages a program needs are not in physical memory?

First half

Demand paging, page-fault handling, lazy allocation and copy-on-write.

Second half

Replacement policies, locality, working sets, thrashing and integrated examples.

What you should be able to do

• Trace page faults and replacements for a reference sequence.
• Relate locality and working-set size to system behaviour.

A concrete example

Trace a memory reference through a page fault, replacement and retry, then compare access patterns.

Reading reference

Operating System Concepts, 10th edition: Chapter 10. We use selected sections rather than every slide in each chapter.

Lecture materials

The slide PDF and illustrated reading are being prepared. Links will appear here when they are available.