CSCI 3500: Studio 15
Modern computer systems use paging to manage memory, which allows
many processes to use memory in a way that is very efficient and
In this studio, you will:
- Do memory paging examples
- Think about tradeoffs in paged memory systems
Please complete the required exercises below, as well as any optional
enrichment exercises that you wish to complete.
As you work through these exercises, please record your answers in a text
file. When finished, submit your work by sending your text file and
source code to firstname.lastname@example.org
with the phrase
in the subject line.
Make sure that the name of each person who worked on these exercises
is listed in the first answer, and make sure you number each of your responses
so it is easy to match your responses with each exercise.
- As the answer to the first exercise, list the names of the people who
worked together on this studio.
- Modern Linux systems commonly use a page size of 4KB (2^10 times 4 bytes).
Suppose a given computer has 1GB (2^30 bytes) of memory. How many
page frames does this machine have?
- Modern x86_64 systems use a 48-bit address space with byte-level addressing.
How many bytes can a modern x86_64 process address?
How many 4KB pages could theoretically exist inside a single process
that uses a 48-bit address space?
- Suppose a program on such a system tries to access the memory location
at (decimal) address 10500. What page does this address reside in and what
is its offset within that page?
- Suppose the page from the previous exercise has been placed in the 67th
page frame. What absolute physical address is generated?
- Suppose you want to play a high def movie that's 15 gigabytes large.
Supposing your system uses 4KB pages, how many page faults should you
expect over the life of the movie?
- Now you're playing the same movie on a system with 32KB pages. How many
page faults should you expect now?
- Say you're designing your own operating system, and you want to implement
your own paging system. Give one advantage of having small page sizes and give one advantage
of having large page sizes.
- Suppose your program needs to open a file and read a single byte from
that file. Knowing what you know now, how much data does this actually require
transferring from the computer disk to memory?
Optional Enrichment Exercises
- No optional exercises