Study Guide for CS414 Midterm

Posted: Friday, Oct 12, 2007

• The following material should be studied for the midterm:

1. The PDFs of the class notes (which can be found at http://www.cs.virginia.edu/~humphrey/cs414) up to and including Thurs Oct 4

NOTE: the material on synchronization (e.g., UNIX signals, race conditions, critical sections, etc.) from Thurs Oct 11 will NOT be on the midterm (this is a change from what I stated in class on Thurs Oct 11). I don't think it's fair to ask you about this on the midterm, because we're only just getting started with this topic.

2. The material in the book:

1. If you have the 6^th edition, then you are expected to know the first 6 chapters (pages 1-188), except:

I. Section 4.6 (“Communication in Client-Server Systems”)

II. The details of the threads packages (Section 5.4, Section 5.5, Section 5.6, Section 5.7, Section 5.8) -- Note that of course you are required to understand what a generic threads package is (up to and including Section 5.3)

III. Section 6.7 ("Process Scheduling Models")

2. If you have the 7^th edition, then you are expected to know the first 5 chapters (pages 1-189), except:

I. Section 3.5 (“Examples of IPC Systems”)

II. Section 3.6 (“Communication in Client-Server Systems”)

III. The details of the threads packages (Section 4.5) -- Note that of course you are required to understand what a generic threads package is (up to and including Section 4.4)

IV. Section 5.5 (“Thread Scheduling”)

V. Section 5.6 (“Operating System Examples”)

3. Assignment #1, Assignment #2, and Assignment #3

• As a general rule, the importance of a particular topic can be determined by the amount of time I spent in class discussing it.
• I will not ask you how a particular OS (e.g., Linux, Windows, etc.) does something. Rather, I will ask you about how a generic OS does something or might do something.
• The format of the exam will be:

1. multiple choice (approx. 20%)
2. short answer (approx. 30%, at most a three-sentence answer)
3. problems similar in style to the questions on Assignments 1,2 and 3 (NOTE: I might ask you to write some code and/or analyze some code) (approx. 50%)

Material to Know

Note: this is not an exhaustive list – rather, this is just a general guideline of material that could be covered on the exam

Overview & History
 reasons for studying OS
 single-user --> batch --> multiprogramming --> time-sharing --> desktop
 user interfaces: command line vs. GUI
 new architectures: multiprocessor, distributed, cluster, real-time, handheld
 
Hardware & OS Background
 computer system structures
 I/O: interrupts, I/O structures, device-status table
 memory: DMA, memory hierarchy (primary vs. secondary), caching
 hardware protection: dual-mode, privileged instructions, 
 base/limit registers, timer interrupts
 networking: LAN (e.g., Ethernet) vs. WAN (e.g., Internet)
 operating system structures
 OS components
 process mgmt, memory mgmt, file mgmt, I/O mgmt
 networking, protection, command interpreter
 OS services
 program execution, I/O, file system, communications, error detection
 system perspective: resource allocation, accounting, protection
 system calls: steps in system call, parameter passing
 kernel: applications programs vs. system programs
 OS structure: simple vs. layered vs. microkernel, virtual machines
 
Processes & Threads
 process
 process states: new, running, waiting, ready, terminated
 PCB, process scheduling queues (ready, waiting, devices)
 schedulers: short-term (CPU scheduler), long-term (job scheduler)
 I/O bound vs. CPU-bound jobs, medium-term scheduler
 CPU context switching
 operations: creation (e.g., fork), termination (e.g., exit),
 others (e.g., execvp, wait)
 process coordination, communications (shared memory vs. message passing)
 threads
 lightweight process
 TCB
 advantages: responsiveness, resource sharing, economy, concurrency
 
CPU scheduling
 historical perspective: simple --> complex --> simple --> complex
 CPU & I/O bursts, burst distribution
 design principle: mechanism vs. policy
 preemptive vs. nonpreemptive scheduling
 scheduling criteria
 CPU utilization, throughput, turnaround, response time, fairness
 scheduling algorithms
 FCFS, SJF (exponential averaging), priority scheduling (starvation, aging),
 RR (quantum size), multilevel queue, multilevel feedback queue
 multiple-processor scheduling, real-time scheduling
 scheduling algorithm evaluation
 deterministic models, simulation, queuing models, implementation