You are expected to do your own work on all homework assignments. You may (and are encouraged to) engage in general discussions with your classmates regarding the assignments, but specific details of a solution, including the solution itself, must always be your own work. (See the statement of Academic Dishonesty on the Syllabus).
Assignments need to be turned in via Lamaku. Check the Syllabus for the late assignment policy for the course.
You should turn in single plain text or PDF file named README.txt, or README.pdf, with your answers to the assignment’s questions. Your file must be readable “as is” and points will be removed if the report is not readable.
Consider the following page table, in which “x” means an invalid entry:
------------------
logical | physical
------------------
| 15 | 9 |
| 14 | x |
| 13 | 40 |
| 12 | x |
| 11 | 25 |
| 10 | x |
| 9 | x |
| 8 | 7 |
| 7 | x |
| 6 | 5 |
| 5 | x |
| 4 | 8 |
| 3 | x |
| 2 | 1 |
| 1 | 0 |
| 0 | 11 |
------------------Assume a 1KiB (i.e., 1,024 bytes) page size. Give the physical address corresponding to the following three logical addresses, or state that an error occurs. For convenience, in this exercise all physical and logical addresses are base-10 values.
Your answer should thus be base-10 values. Show your work for all questions.
[q1 (5 pts)] 2020
[q2 (5 pts)] 8205
[q3 (5 pts)] 6150
[q4 (5 pts)] 13963
Consider a logical address space of 64 pages with 2,048 bytes per page, mapped onto a physical memory of 16 frames.
[q1 (5 pts)] How many bits are required in the logical address? (show your work)
[q2 (5 pts)] How many bits are required in the physical address? (show your work)
Consider a computer system with a 40-bit logical addresses and a 8-KiB page size. The system supports up to 2GiB of physical memory. Give all answers as powers of 2.
[q1 (5 pts)] How many entries are there in a conventional single-level page table? (show your work)
[q2 (5 pts)] How many entries are there in an inverted page table? (show your work)
Suppose we have a computer system with a 38-bit logical address, page size of 32KiB, and 8 bytes per page table entry.
[q1 (5 pts)] Suppose we use two-level paging and arrange for all page tables to fit into a single page frame. How will the bits of the address be divided up? (show your work)
[q2 (5 pts)] Is the outer page table page fully utilized? (show your work)
[q3 (5 pts EXTRA CREDIT)] In the scheme above, assume that only 7 of the entries in the outer-level page table page are valid, and only 1/4 of the entries in all the inner-level page table pages are valid. What is the current total RAM footprint of the address space in MiB (counting the page table pages)? (show your work)