01 Introduction Flashcards
Three OS Goals
- EASE in execution of programs and problem solving
- CONVENIENCE in using comp. system
- EFFICIENCE in using comp hardware
4 Components of a computer system
Hardware
OS
Applications
User
Computer system component which provides basic computing resource
Hardware
Computer system component which controls and coordinates use of hardware among applications and users
Operating system
Computer system component which define how resources are used to solve a problem
Application programs
OS Definition wherein it manages all resources
Resource alloator
OS definition wherein it controls execution of programs to prevent errors and encapsulates the system
Control program
The heart of the OS which is running at all times
Kernel
the _____ is loaded at power up or reboot which loads the OS kernel. This is typically stored in ROM or EPROM known as _____
Bootstrap program
Firmware
Flow of the computer system organization
CPU and device controllers connect thru common bus > provides access to shared memory > compete for memory cycles (concurrent)
Contains all the interrupt service routines
Interrupt vector
Software generated interrupt
Trap or exception
Request to OS to allow user to wait for IO completion
System Call
Contains entry for each IO device; indicating its type, address and state
Device status table
Volatile memory that the CPU can access
Main memory
Determine logical interaction between device and computer
Disk controller
Copy information into faster storage system
Caching
Provide uniform interface between controller and kernel
Device driver
Used for high speed IO devices to transmit information clos to memory speed
1 interrupt per block
Direct memory access
Also known as parallel systems or tightly coupled systems
Multiprocessors
Advantages of parallel systems
Increased throughput
Economy of scale
Increase in reliability
Type of parallel system wherein each processor is assigned to a special task
Assymetric multiprocessing
Type of parallel systems wherein each processor performs all tasks
Symmetric multiprocessor
It is multi’chip and multi’core
It contains multiple separate systems
Dual core
Multiple systems working together
Clustered systems
Sharing storage used by clustered systems
Storage area network
High availability service of a cluster system wherein one machine is in standby mode
Asymmetric clustering
High availability service of a cluster system wherein it has multiple nodes running apps and monitoring each other
Symmetric clustering
What is HPC used by clustered systems
High performance computing
For HPC, apps must be written to use ____
Parallelization
Some clustered systems have this to avoid conflicting operations
Distributed lock manager
An OS structure wherein CPU has idle times and a job is selected via _____
OS switched to another job while waiting
Multiprogramming
Batch system
OS system structur wherein CPU switched jobs so frequently that users can interact with each job
Timesharing
Multitasking
Several jobs are ready to run at the same time
CPU scheduling
Allows execution of processes not completely in memory
Virtual memory
OS operation which allows OS to protect itself and other system components
Dual mode
These type of instructions are only executable in kernel mode
Privileged instructions
Used to prevent infnite loop and hogging of resources
Timer
Mode bit is ZERO
Kernel mode
Mode bit is ONE
user
Abstract physical properties to a logical storage unit
File
Multiprocessor environment should have this tohave the most recent value in their cache
Cache coherency
Overlapping of output of one job with input of another job
Spooling
Mechanism to control access of processes or users to resources
Protecton
Defense of system against internal and external attacks
Security
Allows user to change effective ID with more rights
Privilege escalation
Source CPU use different type from target type
Emulation
Computing language is not compiled into native code
Interpretation
run guest apps on native host OS
Virtualization
