重大操作系统复习提纲

Placement Policy Replacement Algorithms

Demand paging Prepaging

Resident Set Working Set
Optimal policy Least Recently Used (LRU) First-in, first-out (FIFO) Clock Policy

Process Thread

Parallel execution
Processor management

Process

What is Process？ Process Control Block Process States New: A process that has just been created but has not yet




been admitted to the pool of executable processes by the OS. Ready: A process that is prepared to execute when given the opportunity. Running: The process that is currently being executed. Blocked: A process that cannot execute until some event occurs. Exit: A process that has been released from the pool of executable processes by the OS.



a. updated infrequently and accessed frequently in random order? b. updated frequently and accessed in its entirety relatively frequently? c. updated frequently and accessed frequently in random order?


12.3 A file management system is that set of system software that provides services to users and applications in the use of files. 12.6 In a sequential file, a search may involve sequentially testing every record until the one with the matching key is found. The indexed sequential file provides a structure that allows a less exhaustive search to be performed.

Real-Time Scheduling
Processor management

Mutual Exclusion and Synchronization



critical resource（临界资源）: nonsharable resource. Critical section（临界区）: program to access critical resource Semaphores
Disk Scheduling

Disk Performance Parameters Disk Scheduling Policies
ห้องสมุดไป่ตู้
First-in, first-out (FIFO) Priority (PRI) Last-in, first-out Shortest Service Time First (SSTF) SCAN C-SCAN N-step-SCAN FSCAN

Virtual Memory


Relocation Protection Sharing
Memory management

Memory Partitioning

Fixed Partitioning

Placement Algorithm Placement Algorithm


a. Indexed b. Indexed sequential c. Hashed or indexed
复习提纲
考试说明




试卷为英文卷，可以中文回答，也可以 英文回答。 考试内容为教材第1—12章教学内容。 最后成绩组成：理论考试（50%）+实验 （20%）+课后作业（20%）+测验 （10%） 试卷内容包含：教学内容、每章节后的 习题、测验题、实验题等

Aim of Scheduling

Response time Throughput Processor efficiency

First-Come-First-Served Round Robin Shortest Process Next Shortest Remaining Time Highest Response Ratio Next Feedback




Fixed blocking: F =B div R Variable-length spanned blocking: F =(B- P)/(R+ P) Variable-length unspanned blocking: F =(B-R/2)/R

12.3 What file organization would you choose to maximize efficiency in terms of speed of access, use of storage space, and ease of updating (adding/deleting/modifying) when the data are

Segmentation




combine segmentation and paging Table 8.2 Characteristics of Paging and Segmentation Address Translation
Memory management

Fetch Policy
I/O and File system

I/O Design Objectives

Efficiency Generality Single Buffer Double Buffer Circular Buffer

I/O Buffering

I/O and File system


Processor management Memory management I/O and File system
Processor management

Program execution Modal

Serial execution Concurrent execution

I/O and File system

File Operations

Create Delete Open Close Read Write


Criteria for File Organization File organization and access

Pile, Sequential , Indexed Sequential , Indexed, Hashed

semWait semSignal

Monitors Message Passing
Processor management

Deadlock


Conditions for Deadlock Deadlock Prevention Deadlock Avoidance

banker’s algorithm Deadlock Detection Algorithm

Record Blocking
Processor management

Modes of Process Execution


User mode System mode process switching——When to Switch Process
Processor management

Processor Scheduling

Dynamic Partitioning

Best-fit algorithm First-fit algorithm Next-fit

Buddy System
Memory management

Paging

Frames Pages Page Table Free Frame List Segment Tables
习题

12.3 What is a file management system?
12.6 Why is the average search time to find a record in a file less for an indexed sequential file than for a sequential file?

Deadlock Detection


starvation
Memory management

Main Memory Management

Memory Partitioning Partition Management Locality and Virtual Memory Used Policy