Lec 5 Virtual Memory Management

Paged Memory Allocation: Dividing a process into fixed-size “pages” and storing them in memory “frames” (of equal size).
Demand Paging: Loading pages into memory only when they are needed, reducing the need to load entire programs.
Segmented Memory Allocation: Dividing a process into variable-sized “segments,” often based on logical program units (e.g., code, data, stack).
Segmented/Demand Paging: A hybrid approach combining segmentation and demand paging.

Main Point: A memory management technique that makes the available memory appear larger than physical RAM.
How It Works: The OS uses secondary storage (e.g., hard disk) to extend the available memory, swapping pages of data between RAM and secondary storage.
Advantage: Allows programs to use more memory than is physically available.
Programmers don’t need to worry about writing overlay codes

~A fundamental technique for virtual memory implementation.

Paging is a memory management technique used by operating systems.It allows data to be stored and retrieved between secondary storage and main memory.
Creates the impression of more memory than is physically available.
Data is managed in fixed-size blocks called pages.
Paging: Divides logical address space (virtual) into equal-sized pages and physical memory into equal-sized frames.
Page Size: Page sizes are typically equal to frame sizes.
MMU (Memory Management Unit): Hardware component responsible for translating virtual addresses to physical addresses.
Non-Contiguous Allocation: Pages can be stored in any available frame, preventing external fragmentation.

Before a program is loaded, it is divided into pages that are loaded into page frames in memory.
Paged memory allocation : concept of dividing incoming job into pages of equal size

How it Works: The Memory Manager:
- Determines the number of pages in a program.
- Finds enough free page frames in memory.
- Loads the pages into those frames.
Non-Contiguous Loading: Pages don’t need to be loaded into adjacent frames.

NOTE

This note ain’t done yet :(

🐉 neospace ~