+---------------------+
			|        CS 439       |
			|     PROJECT 3: VM   |
			|     CODE READING    |
			+---------------------+

1. Where is palloc_get_page() and what does it do?
2. What does PAL_USER do when passed in as a parameter to palloc_get_page()?
3. What is the purpose of the page directory (pagedir) in Pintos and how does it
relate to the page tables we have learned in class?
4. What function are provided for operations on page directories?
5. What is the difference between the page directory that is already implemented
and the supplemental page table that you will be implementing?
6. Where are is_user_vaddr() and is_kernel_vaddr() and what do they do?
7. What is BLOCK_SWAP?  How is it used in the code?
8. What functions are provided to access a block device?