Homework 4

INSTRUCTIONS

Out: October 17, 2005.
Due: At the start of lecture, November 2 (Wednesday), 2005. We will accept only solutions that are typed-up and printed out (figures and tables may be drawn by hand). No written solutions or online handins.
Resources you are allowed to use: Unless otherwise mentioned, the only resources you can use are the lectures slides, your notes, the Tanenbaum textbook, and any other textbook on OS's, architecture, data structures or previous CS material. You cannot refer to any online resources (unless otherwise mentioned). You cannot use ready-made solutions under any circumstances..
 Relevant Lectures: 13-21.
 Points: Unless otherwise mentioned, a problem is worth 5 points. The HW is worth a total of 40 points. If a question has multiple parts, the 5 points are split equally among the parts.
 Warning: Homeworks are individual efforts. Although you are allowed to discuss HWs with your fellow students, you are expected to solve them yourself and type up the solution yourself. For detailed information on penalties, cheating and playing it safe, see this page.

PROBLEMS

  1. Problem 4.5 from text.
  2. Problem 4.15 from text.
  3. Problem 4.16 from text. Give (a) the page reference string, and (b) calculate the number of page faults if LRU page replacement is used in a main memory with 3 physical frames.
  4. Problem 4.31 from text.
  5. Problem 5.11 from text (assume the question talks about fetching only 1 sector at a time).
  6. Problem 5.12 from text.
  7. Problem 5.24 from text.
  8. One of the students in the class suggested that it might be feasible to take the basic idea/trick underlying soft timers, but use it additionally for also polling other I/O devices (not just the clock) that currently have pending requests. How would this scheme work (describe briefly in a paragraph)? Also, give one advantage of doing so, and one disadvantage of doing so.

Updated: Oct. 14, 2005. (c) Indranil Gupta.