Sv39, Level by Level

Exercise: 33k_paging · Fri Oct 9 · Length: 5:45 · Lecture: Week 7 · The walk · Explainer: Sv39, Level by Level

A narrated walk through the explainer, for before Tuesday's lecture and before Friday's session: page tables are ordinary pages, each read as 512 slots; three lookups from the root find one address's page, and a second address stops at an empty slot, not mapped. Then a mapping under a bare root: for each missing table a page is taken, zeroed, and only then linked in. Two pictures show why a page is not a table until it is zeroed, and the video ends on what walk is given and hands back, and how to read the line a failed check prints. It shows no solution code: only what the tables hold at each step, with numbers that are examples, not the lecture's.

Download the video (MP4, 15 MB) · Captions (WebVTT) · All four Week 7 videos