Paging concept and page tables in Operating Systems - Mini Project: Build & Apply

Understanding Paging Concept and Page Tables

📖 Scenario: You are learning how computers manage memory using paging. Paging helps the computer divide memory into fixed-size blocks called pages. These pages are tracked using a page table, which maps virtual memory addresses to physical memory addresses.Imagine you have a simple computer memory system that uses paging to keep track of where data is stored.

🎯 Goal: Build a simple representation of a page table using a dictionary. Then, configure the page size, and finally, create a function that translates virtual page numbers to physical frame numbers using the page table.

📋 What You'll Learn

Create a dictionary called page_table with exact mappings of virtual pages to physical frames.

Create a variable called page_size and set it to the exact value 4096.

Write a function called translate_page that takes a virtual page number and returns the corresponding physical frame number using page_table.

Add a final line that sets a variable example_translation by calling translate_page with virtual page number 3.

💡 Why This Matters

🌍 Real World

Paging is used in modern operating systems to manage memory efficiently and safely by mapping virtual addresses to physical memory.

💼 Career

Understanding paging and page tables is essential for roles in system programming, operating system development, and computer architecture.

1

Create the page table dictionary

Create a dictionary called page_table with these exact entries: 0: 5, 1: 9, 2: 1, 3: 7, 4: 3.

Operating Systems

# Create the page_table dictionary with given mappings
# Your code here

Need a hint?

Use curly braces {} to create a dictionary with keys as virtual pages and values as physical frames.

2

Set the page size

Create a variable called page_size and set it to the integer value 4096.

Operating Systems

page_table = {0: 5, 1: 9, 2: 1, 3: 7, 4: 3}
# Set the page_size variable to 4096
# Your code here

Need a hint?

Assign the number 4096 directly to the variable page_size.

3

Write the translation function

Write a function called translate_page that takes one parameter virtual_page and returns the physical frame number by looking up virtual_page in the page_table dictionary.

Operating Systems

page_table = {0: 5, 1: 9, 2: 1, 3: 7, 4: 3}
page_size = 4096
# Define translate_page function below
# Your code here

Need a hint?

Define a function using def and return the value from page_table using the key virtual_page.

4

Translate a sample virtual page

Create a variable called example_translation and set it to the result of calling translate_page with the argument 3.

Operating Systems

page_table = {0: 5, 1: 9, 2: 1, 3: 7, 4: 3}
page_size = 4096

def translate_page(virtual_page):
    return page_table[virtual_page]

# Set example_translation by translating virtual page 3
# Your code here

Need a hint?

Call the function translate_page with 3 and assign the result to example_translation.