CS 3210 Operating System Design
Spring 2005 y Hutto
Georgia Tech, College of Computing
Homework 1
DUE: 3:05 pm (class time) Th 27 January 2005
Topics Covered:
• OS/Kernel Intro
• Booting/Kernel Init
• System Calls, Modules, /proc
• Memory Addressing
Work individually on this. Please prepare printed solutions using the word processing software of
your choice to the following questions (no handwritten solutions accepted) and bring to class on the
due date. Answers should be short but concise. Questions amplify material from the lectures and the
assigned readings. Questions frequently require you to investigate Linux or OS features and
capabilities. Please make use of all available resources (web, man pages, kernel source, discussions
with staff, etc.). Most questions can be answered in a well-constructed paragraph or two. We aren’t
trying to kill you with the homeworks. These are mostly to acquaint you with some interesting
additional material. So have fun!
1. Two popular contemporary approaches for structuring operating systems are microkernels and
exokernels. Compare and contrast the two approaches. How are they similar? How are they different?
MIT Exokernel Operating System - www.pdos.lcs.mit.edu/exo.html
DMOZ Microkernel page – dmoz.org/Computers/Software/Operating_Systems/Microkernel/
2. The Linux kernel provides a moderately complex subsystem for logging status and error
messages printed by the kernel during boot and normal operation. Briefly describe the following
components of the kernel logging subsystem and explain how they are related. (Hints: A picture
might be nice. Start with the man pages and then try looking at the source code for printk() in
kernel/printk.c. There is also a nice discussion in the Debugging chapter of Love.)
• dmesg
• console log level
• kernel log buffer
• klogctl()
• syslogd
• klogd
• /proc/kmsg
3. Read about BogoMips and why they are so bogus (dude!) in your textbooks and on the web.
Describe how the function calibrate_delay() in kernel/main.c computes (calibrates, estimates)
BogoMips for the current processor. Compare the BogoMips value reported by your iPAQ and by a
workstation in the States Cluster or your own Linux workstation or laptop. How are BogoMips
reported on an SMP machine?
