Go on. Explore!

lvl 0 • 0 xp

lvl 1

Home Market Decks Interests

Midterm 1 OS

memorize.ai (lvl 286)

(0)

15 cards

()

Section 1

Preview this deck

Starvation- indefinite blocking

Front

1 / 15

iOS Dev Swift

0.0

0 reviews

5			0
4			0
3			0
2			0
1			0

Active users

All-time users

Favorites

Last updated

6 years ago

Date created

Mar 1, 2020

Cards (15)

Section 1

(15 cards)

Starvation- indefinite blocking

Front

A process may never be removed from the semaphore queue in which it is suspended

Back

First Purpose of an Operating System

Front

Provide an environment in which a user can execute programs conveniently and efficiently

Back

Logical Address

Front

Also called virtual address The address that the CPU generates and sends to the Memory Management Unit (MMU)

Back

9 Operating System Services

Front

User interface, program execution, i/o operations, file-system manipulation, communication, error detection, resource allocation, accounting, protection and security

Back

Paging

Front

Solves the problem of external fragmentation Memory is divided into frames of a fixed size (512 bytes - 1GB) Processes are divided into pages of the same size Logical address is <page #, offset> Pages can be scattered throughout memory Internal Fragmentation is the trade-off Last page likely not exactly the same size as a page Average internal fragmentation per process is ½ page size - not bad

Back

Contiguous Memory Allocation

Front

Processes are stored in single, unbroken chunks When processes terminate, holes are formed Holes can be used for future processes Over time, memory can be filled with many small holes, too small for contiguous processes to fit This is called External Fragmentation Compaction can be used to defragment memory

Back

Second Purpose of an Operating System

Front

Allocate Resources fairly and efficiently

Back

What are the 5 Operating System responsibilities in connection with Process Management

Front

Creating and deleting processes, suspending and resuming processes, providing a mechanism for process synchronization, providing a mechanism for process communication, providing a mechanism for deadlock handling

Back

Name and describe the 6 scheduling algorithms from the text

Front

FCFS - As the name implies... process/thread is allowed to run until the CPU-burst is complete regardless of time SJF - As processes enter ready queue, the shortest job gets priority SJRF - Use preemption to swap out process with less time remaining Priority Scheduling - Order (and preempt) based on user-given priority (starvation is an issue) Round-Robin - Use time quanta on a not-to-exceed basis. Then order by FCFS Multilevel Queue Scheduling - Use multiple queues for different level processes. Sort based on characteristics of CPU-burst Multilevel Feedback Queue - Same as above but allow processes to move between queues

Back

Physical Address

Front

The actual address in memory used to retrieve instructions or data. The act of translating a logical address into a physical address is called address binding

Back

Address Binding

Front

Compile time The compiler decides what absolute address will be used Compiler must know where the process will reside in memory Load time Compiler generates relocatable code Final binding is done when the process is loaded Execution time Process can be moved in memory during execution Binding must be delayed until run time

Back

5 Process States

Front

New,Executing, Waiting, Ready, Terminated

Back

Deadlock

Front

two or more processes are waiting indefinitely for an event that can be caused by only one of the waiting processes

Back

Translation Look-aside Buffer (TLB)

Front

Resides in cache When CPU looks for a page to frame translation, it checks the TLB first If the page is not in the TLB, it goes to the page table in memory The page number is then stored in the TLB along with the corresponding frame number Access time is almost cut in half with a high TLB hit rate

Back

Third purpose of an operating system

Front

Acts as a control program to supervise the execution of programs to protect the system and to manage and control the operation of I/O systems

Back