Submit Search
Upload
cs231_ch1_ch2.pptx
•
Download as PPTX, PDF
•
0 likes
•
3 views
A
arijeetpramanik21b
Follow
Introductory Notes on Operating System Concepts
Read less
Read more
Engineering
Report
Share
Report
Share
1 of 60
Download now
Recommended
ch01.ppt
ch01.ppt
emomani1
ch1.pptx
ch1.pptx
ZoYaKazmi3
ch01.ppt
ch01.ppt
HasnainAli343946
slide 4 systemsch1-great slide 4 systems.pptx
slide 4 systemsch1-great slide 4 systems.pptx
thanhan858423
ch1.pptx
ch1.pptx
AsahiHamada14
Ch1
Ch1
Supakit Seansaart
ch1.ppt
ch1.ppt
MuhammadHussain552860
ch1.ppt
ch1.ppt
GMSakhawatHossain
Recommended
ch01.ppt
ch01.ppt
emomani1
ch1.pptx
ch1.pptx
ZoYaKazmi3
ch01.ppt
ch01.ppt
HasnainAli343946
slide 4 systemsch1-great slide 4 systems.pptx
slide 4 systemsch1-great slide 4 systems.pptx
thanhan858423
ch1.pptx
ch1.pptx
AsahiHamada14
Ch1
Ch1
Supakit Seansaart
ch1.ppt
ch1.ppt
MuhammadHussain552860
ch1.ppt
ch1.ppt
GMSakhawatHossain
ch1.ppt
ch1.ppt
RishabhSharma846139
ch1.ppt
ch1.ppt
ssuserea967d
ch1.ppt
ch1.ppt
Murali Krishna Kanajam
ch1.ppt
ch1.ppt
ssuserfdf7272
ch1.ppt
ch1.ppt
GomathiShanmugam5
ch1.ppt
ch1.ppt
Sami Mughal
Ch1
Ch1
neelamoberoi1030
ch1.pptx
ch1.pptx
SAVITHRIMC
ch1.ppthjhgjhghjghjgjhgugugugmhjgh iyuyuy
ch1.ppthjhgjhghjghjgjhgugugugmhjgh iyuyuy
pavan402055
ch1.ppt
ch1.ppt
MalikNuman8
ch1.ppt
ch1.ppt
JamelPandiin2
cs8493 - operating systems unit 1
cs8493 - operating systems unit 1
SIMONTHOMAS S
Linux operating system fundamentals of Operating System
Linux operating system fundamentals of Operating System
IraqReshi
Operating system introduction
Operating system introduction
SandeepKumar484971
ch1.pdf
ch1.pdf
SanthoshSgrao2
ch1 operating system chapter 1 to OS.pptx
ch1 operating system chapter 1 to OS.pptx
Zahoorahmed536759
Ch1 Operating System
Ch1 Operating System
ChhayaShelake
ch1-os.pptx
ch1-os.pptx
funnyvideosbysam
Operating System - Unit I - Introduction
Operating System - Unit I - Introduction
cscarcas
Operating System
Operating System
Bhaiyasaheb Bodhak
What are the advantages and disadvantages of membrane structures.pptx
What are the advantages and disadvantages of membrane structures.pptx
wendy cai
VIP Call Girls Service Kondapur Hyderabad Call +91-8250192130
VIP Call Girls Service Kondapur Hyderabad Call +91-8250192130
Suhani Kapoor
More Related Content
Similar to cs231_ch1_ch2.pptx
ch1.ppt
ch1.ppt
RishabhSharma846139
ch1.ppt
ch1.ppt
ssuserea967d
ch1.ppt
ch1.ppt
Murali Krishna Kanajam
ch1.ppt
ch1.ppt
ssuserfdf7272
ch1.ppt
ch1.ppt
GomathiShanmugam5
ch1.ppt
ch1.ppt
Sami Mughal
Ch1
Ch1
neelamoberoi1030
ch1.pptx
ch1.pptx
SAVITHRIMC
ch1.ppthjhgjhghjghjgjhgugugugmhjgh iyuyuy
ch1.ppthjhgjhghjghjgjhgugugugmhjgh iyuyuy
pavan402055
ch1.ppt
ch1.ppt
MalikNuman8
ch1.ppt
ch1.ppt
JamelPandiin2
cs8493 - operating systems unit 1
cs8493 - operating systems unit 1
SIMONTHOMAS S
Linux operating system fundamentals of Operating System
Linux operating system fundamentals of Operating System
IraqReshi
Operating system introduction
Operating system introduction
SandeepKumar484971
ch1.pdf
ch1.pdf
SanthoshSgrao2
ch1 operating system chapter 1 to OS.pptx
ch1 operating system chapter 1 to OS.pptx
Zahoorahmed536759
Ch1 Operating System
Ch1 Operating System
ChhayaShelake
ch1-os.pptx
ch1-os.pptx
funnyvideosbysam
Operating System - Unit I - Introduction
Operating System - Unit I - Introduction
cscarcas
Operating System
Operating System
Bhaiyasaheb Bodhak
Similar to cs231_ch1_ch2.pptx
(20)
ch1.ppt
ch1.ppt
ch1.ppt
ch1.ppt
ch1.ppt
ch1.ppt
ch1.ppt
ch1.ppt
ch1.ppt
ch1.ppt
ch1.ppt
ch1.ppt
Ch1
Ch1
ch1.pptx
ch1.pptx
ch1.ppthjhgjhghjghjgjhgugugugmhjgh iyuyuy
ch1.ppthjhgjhghjghjgjhgugugugmhjgh iyuyuy
ch1.ppt
ch1.ppt
ch1.ppt
ch1.ppt
cs8493 - operating systems unit 1
cs8493 - operating systems unit 1
Linux operating system fundamentals of Operating System
Linux operating system fundamentals of Operating System
Operating system introduction
Operating system introduction
ch1.pdf
ch1.pdf
ch1 operating system chapter 1 to OS.pptx
ch1 operating system chapter 1 to OS.pptx
Ch1 Operating System
Ch1 Operating System
ch1-os.pptx
ch1-os.pptx
Operating System - Unit I - Introduction
Operating System - Unit I - Introduction
Operating System
Operating System
Recently uploaded
What are the advantages and disadvantages of membrane structures.pptx
What are the advantages and disadvantages of membrane structures.pptx
wendy cai
VIP Call Girls Service Kondapur Hyderabad Call +91-8250192130
VIP Call Girls Service Kondapur Hyderabad Call +91-8250192130
Suhani Kapoor
Architect Hassan Khalil Portfolio for 2024
Architect Hassan Khalil Portfolio for 2024
hassan khalil
Biology for Computer Engineers Course Handout.pptx
Biology for Computer Engineers Course Handout.pptx
DeepakSakkari2
★ CALL US 9953330565 ( HOT Young Call Girls In Badarpur delhi NCR
★ CALL US 9953330565 ( HOT Young Call Girls In Badarpur delhi NCR
9953056974 Low Rate Call Girls In Saket, Delhi NCR
(PRIYA) Rajgurunagar Call Girls Just Call 7001035870 [ Cash on Delivery ] Pun...
(PRIYA) Rajgurunagar Call Girls Just Call 7001035870 [ Cash on Delivery ] Pun...
ranjana rawat
HARDNESS, FRACTURE TOUGHNESS AND STRENGTH OF CERAMICS
HARDNESS, FRACTURE TOUGHNESS AND STRENGTH OF CERAMICS
RajkumarAkumalla
Call Us -/9953056974- Call Girls In Vikaspuri-/- Delhi NCR
Call Us -/9953056974- Call Girls In Vikaspuri-/- Delhi NCR
9953056974 Low Rate Call Girls In Saket, Delhi NCR
APPLICATIONS-AC/DC DRIVES-OPERATING CHARACTERISTICS
APPLICATIONS-AC/DC DRIVES-OPERATING CHARACTERISTICS
KurinjimalarL3
Analog to Digital and Digital to Analog Converter
Analog to Digital and Digital to Analog Converter
AbhinavSharma374939
MANUFACTURING PROCESS-II UNIT-2 LATHE MACHINE
MANUFACTURING PROCESS-II UNIT-2 LATHE MACHINE
SIVASHANKAR N
Model Call Girl in Narela Delhi reach out to us at 🔝8264348440🔝
Model Call Girl in Narela Delhi reach out to us at 🔝8264348440🔝
soniya singh
HARMONY IN THE NATURE AND EXISTENCE - Unit-IV
HARMONY IN THE NATURE AND EXISTENCE - Unit-IV
RajaP95
Current Transformer Drawing and GTP for MSETCL
Current Transformer Drawing and GTP for MSETCL
DeelipZope
247267395-1-Symmetric-and-distributed-shared-memory-architectures-ppt (1).ppt
247267395-1-Symmetric-and-distributed-shared-memory-architectures-ppt (1).ppt
ssuser5c9d4b1
(MEERA) Dapodi Call Girls Just Call 7001035870 [ Cash on Delivery ] Pune Escorts
(MEERA) Dapodi Call Girls Just Call 7001035870 [ Cash on Delivery ] Pune Escorts
ranjana rawat
IMPLICATIONS OF THE ABOVE HOLISTIC UNDERSTANDING OF HARMONY ON PROFESSIONAL E...
IMPLICATIONS OF THE ABOVE HOLISTIC UNDERSTANDING OF HARMONY ON PROFESSIONAL E...
RajaP95
High Profile Call Girls Nagpur Isha Call 7001035870 Meet With Nagpur Escorts
High Profile Call Girls Nagpur Isha Call 7001035870 Meet With Nagpur Escorts
ranjana rawat
Software Development Life Cycle By Team Orange (Dept. of Pharmacy)
Software Development Life Cycle By Team Orange (Dept. of Pharmacy)
Suman Mia
SPICE PARK APR2024 ( 6,793 SPICE Models )
SPICE PARK APR2024 ( 6,793 SPICE Models )
Tsuyoshi Horigome
Recently uploaded
(20)
What are the advantages and disadvantages of membrane structures.pptx
What are the advantages and disadvantages of membrane structures.pptx
VIP Call Girls Service Kondapur Hyderabad Call +91-8250192130
VIP Call Girls Service Kondapur Hyderabad Call +91-8250192130
Architect Hassan Khalil Portfolio for 2024
Architect Hassan Khalil Portfolio for 2024
Biology for Computer Engineers Course Handout.pptx
Biology for Computer Engineers Course Handout.pptx
★ CALL US 9953330565 ( HOT Young Call Girls In Badarpur delhi NCR
★ CALL US 9953330565 ( HOT Young Call Girls In Badarpur delhi NCR
(PRIYA) Rajgurunagar Call Girls Just Call 7001035870 [ Cash on Delivery ] Pun...
(PRIYA) Rajgurunagar Call Girls Just Call 7001035870 [ Cash on Delivery ] Pun...
HARDNESS, FRACTURE TOUGHNESS AND STRENGTH OF CERAMICS
HARDNESS, FRACTURE TOUGHNESS AND STRENGTH OF CERAMICS
Call Us -/9953056974- Call Girls In Vikaspuri-/- Delhi NCR
Call Us -/9953056974- Call Girls In Vikaspuri-/- Delhi NCR
APPLICATIONS-AC/DC DRIVES-OPERATING CHARACTERISTICS
APPLICATIONS-AC/DC DRIVES-OPERATING CHARACTERISTICS
Analog to Digital and Digital to Analog Converter
Analog to Digital and Digital to Analog Converter
MANUFACTURING PROCESS-II UNIT-2 LATHE MACHINE
MANUFACTURING PROCESS-II UNIT-2 LATHE MACHINE
Model Call Girl in Narela Delhi reach out to us at 🔝8264348440🔝
Model Call Girl in Narela Delhi reach out to us at 🔝8264348440🔝
HARMONY IN THE NATURE AND EXISTENCE - Unit-IV
HARMONY IN THE NATURE AND EXISTENCE - Unit-IV
Current Transformer Drawing and GTP for MSETCL
Current Transformer Drawing and GTP for MSETCL
247267395-1-Symmetric-and-distributed-shared-memory-architectures-ppt (1).ppt
247267395-1-Symmetric-and-distributed-shared-memory-architectures-ppt (1).ppt
(MEERA) Dapodi Call Girls Just Call 7001035870 [ Cash on Delivery ] Pune Escorts
(MEERA) Dapodi Call Girls Just Call 7001035870 [ Cash on Delivery ] Pune Escorts
IMPLICATIONS OF THE ABOVE HOLISTIC UNDERSTANDING OF HARMONY ON PROFESSIONAL E...
IMPLICATIONS OF THE ABOVE HOLISTIC UNDERSTANDING OF HARMONY ON PROFESSIONAL E...
High Profile Call Girls Nagpur Isha Call 7001035870 Meet With Nagpur Escorts
High Profile Call Girls Nagpur Isha Call 7001035870 Meet With Nagpur Escorts
Software Development Life Cycle By Team Orange (Dept. of Pharmacy)
Software Development Life Cycle By Team Orange (Dept. of Pharmacy)
SPICE PARK APR2024 ( 6,793 SPICE Models )
SPICE PARK APR2024 ( 6,793 SPICE Models )
cs231_ch1_ch2.pptx
1.
Silberschatz, Galvin and
Gagne ©2018 Operating System Concepts -10th Edition Chapter 1 & 2
2.
1.2 Silberschatz, Galvin
and Gagne ©2018 Operating System Concepts – 10th Edition Objectives To provide a grand tour of the major operating systems components To provide coverage of basic computer system organization Text Book: Operating Systems Concepts, 10th Edition Silberschatz, Galvin, and Gagne
3.
1.3 Silberschatz, Galvin
and Gagne ©2018 Operating System Concepts – 10th Edition What is an Operating System? A program that acts as an intermediary between a user of a computer and the computer hardware Operating system goals: Execute user programs and make solving user problems easier Make the computer system convenient to use Use the computer hardware in an efficient manner
4.
1.4 Silberschatz, Galvin
and Gagne ©2018 Operating System Concepts – 10th Edition Computer System Structure Computer system can be divided into four components: Hardware – provides basic computing resources CPU, memory, I/O devices Operating system Controls and coordinates use of hardware among various applications and users Application programs – define the ways in which the system resources are used to solve the computing problems of the users Word processors, compilers, web browsers, database systems, video games Users People, machines, other computers
5.
1.5 Silberschatz, Galvin
and Gagne ©2018 Operating System Concepts – 10th Edition Abstract View of Components of Computer
6.
1.6 Silberschatz, Galvin
and Gagne ©2018 Operating System Concepts – 10th Edition What Operating Systems Do Depends on the point of view Users want convenience, ease of use and good performance Don’t care about resource utilization But shared computer such as mainframe or minicomputer must keep all users happy Users of dedicated systems such as workstations have dedicated resources but frequently use shared resources from servers Handheld computers (like smartphones and tables) are resource poor, optimized for usability and battery life Some computers have little or no user interface, such as embedded computers in devices and automobiles Run primarily without user intervention
7.
1.7 Silberschatz, Galvin
and Gagne ©2018 Operating System Concepts – 10th Edition Operating System Definition OS is a resource allocator Manages all resources Decides between conflicting requests for efficient and fair resource use OS is a control program Controls execution of programs to prevent errors and improper use of the computer Error in one program should not affect other programs
8.
1.8 Silberschatz, Galvin
and Gagne ©2018 Operating System Concepts – 10th Edition Operating System Definition (Cont.) No universally accepted definition “Everything a vendor ships when you order an operating system” is a good approximation But varies wildly “The one program running at all times on the computer” is the kernel. Everything else is either A system program (ships with the operating system, but not part of the kernel) , or An application program, all programs not associated with the operating system
9.
1.9 Silberschatz, Galvin
and Gagne ©2018 Operating System Concepts – 10th Edition Computer Startup bootstrap program is loaded at power-up or reboot Typically stored in ROM or EPROM, generally known as firmware Initializes all aspects of a system Loads the operating system kernel and starts its execution
10.
1.10 Silberschatz, Galvin
and Gagne ©2018 Operating System Concepts – 10th Edition Computer System Organization Computer-system operation One or more CPUs, device controllers connect through a common bus providing access to shared memory Concurrent execution of CPUs and devices competing for memory cycles
11.
1.11 Silberschatz, Galvin
and Gagne ©2018 Operating System Concepts – 10th Edition Computer-System Operation I/O devices and the CPU can execute concurrently Each device controller is in charge of a particular device type Each device controller has a local buffer Each device controller type has an operating system device driver to manage it CPU moves data from/to main memory to/from controller local buffers I/O is from the device to local buffer of controller Device controller informs CPU that it has finished its operation by causing an interrupt
12.
1.12 Silberschatz, Galvin
and Gagne ©2018 Operating System Concepts – 10th Edition Common Functions of Interrupts Interrupt transfers control to an interrupt service routine generally, through an interrupt vector, which contains the addresses of all the service routines. The interrupt source decides which entry of the vector is to be used. Interrupt architecture must save the address of the interrupted instruction Incoming interrupts are disabled while another interrupt is being processed to prevent a lost interrupt A trap or exception is a software-generated interrupt caused either by an error or a user request An operating system is interrupt driven
13.
1.13 Silberschatz, Galvin
and Gagne ©2018 Operating System Concepts – 10th Edition Interrupt Handling The operating system preserves the state of the CPU by storing registers and the program counter Determines which type of interrupt has occurred: By polling Through vectored interrupt system Separate segments of code determine what action should be taken for each type of interrupt
14.
1.14 Silberschatz, Galvin
and Gagne ©2018 Operating System Concepts – 10th Edition Interrupt Timeline
15.
1.15 Silberschatz, Galvin
and Gagne ©2018 Operating System Concepts – 10th Edition I/O Structure Two methods for handling I/O 1. After I/O starts, control returns to user program only upon I/O completion Wait instruction idles the CPU until the next interrupt Wait loop (contention for memory access) At most one I/O request is outstanding at a time, no simultaneous I/O processing 2. After I/O starts, control returns to user program without waiting for I/O completion System call – request to the operating system to allow user to wait for I/O completion Device-status table contains entry for each I/O device indicating its type, address, and state Operating system indexes into I/O device table to determine device status and to modify table entry to include interrupt
16.
1.16 Silberschatz, Galvin
and Gagne ©2018 Operating System Concepts – 10th Edition Direct Memory Access Structure Used by high-speed I/O devices: able to transmit information at close to memory speeds Device controller transfers blocks of data from its local buffer storage directly to main memory without CPU intervention Only one interrupt is generated per block, rather than the one interrupt per byte
17.
1.17 Silberschatz, Galvin
and Gagne ©2018 Operating System Concepts – 10th Edition Storage Structure Main memory – only large storage media that the CPU can access directly Random access Typically volatile Secondary storage – extension of main memory that provides large nonvolatile storage capacity Magnetic disks – rigid metal or glass platters covered with magnetic recording material Disk surface is logically divided into tracks, which are subdivided into sectors The disk controller determines the logical interaction between the device and the computer Solid State disks Nonvolatile NAND flash memory; no moving parts; faster than disks Interface is the same as disks Reads faster than writes; no over-writes; limited number of writes.
18.
1.18 Silberschatz, Galvin
and Gagne ©2018 Operating System Concepts – 10th Edition Storage Hierarchy Storage systems organized in hierarchy Speed Cost Volatility Caching – copying information into faster storage system; main memory can be viewed as a cache for secondary storage
19.
1.19 Silberschatz, Galvin
and Gagne ©2018 Operating System Concepts – 10th Edition Storage-Device Hierarchy
20.
1.20 Silberschatz, Galvin
and Gagne ©2018 Operating System Concepts – 10th Edition Caching Important principle, performed at many levels in a computer (in hardware, operating system, software) Information in use copied from slower to faster storage temporarily Faster storage (cache) checked first to determine if information is there If it is, information used directly from the cache (fast) If not, data copied to cache and used there Cache smaller than storage being cached Cache management important design problem Cache size and replacement policy
21.
1.21 Silberschatz, Galvin
and Gagne ©2018 Operating System Concepts – 10th Edition Computer-System Architecture Most systems use a single general-purpose processor (PDAs through mainframes) Most systems have special-purpose processors as well Multiprocessors systems growing in use and importance Also known as parallel systems, tightly-coupled systems Advantages include: 1. Increased throughput 2. Economy of scale 3. Increased reliability – graceful degradation or fault tolerance Two types: 1. Asymmetric Multiprocessing 2. Symmetric Multiprocessing
22.
1.22 Silberschatz, Galvin
and Gagne ©2018 Operating System Concepts – 10th Edition How a Modern Computer Works A von Neumann architecture
23.
1.23 Silberschatz, Galvin
and Gagne ©2018 Operating System Concepts – 10th Edition Symmetric Multiprocessing Architecture
24.
1.24 Silberschatz, Galvin
and Gagne ©2018 Operating System Concepts – 10th Edition A Dual-Core Design
25.
1.25 Silberschatz, Galvin
and Gagne ©2018 Operating System Concepts – 10th Edition Dual-Core with shared cache
26.
1.26 Silberschatz, Galvin
and Gagne ©2018 Operating System Concepts – 10th Edition Intel Haswell chip LLC – Last Level Cache 1.4 billion transistors
27.
1.27 Silberschatz, Galvin
and Gagne ©2018 Operating System Concepts – 10th Edition
28.
1.28 Silberschatz, Galvin
and Gagne ©2018 Operating System Concepts – 10th Edition
29.
1.29 Silberschatz, Galvin
and Gagne ©2018 Operating System Concepts – 10th Edition Clustered Systems Like multiprocessor systems, but multiple systems working together Usually sharing storage via a storage-area network (SAN) Provides a high-availability service which survives failures Asymmetric clustering has one machine in hot-standby mode Symmetric clustering has multiple nodes running applications, monitoring each other Some clusters are for high-performance computing (HPC) Applications must be written to use parallelization
30.
1.30 Silberschatz, Galvin
and Gagne ©2018 Operating System Concepts – 10th Edition Clustered Systems
31.
1.31 Silberschatz, Galvin
and Gagne ©2018 Operating System Concepts – 10th Edition Operating System Structure Multiprogramming needed for efficiency Single user cannot keep CPU and I/O devices busy at all times Multiprogramming organizes jobs (code and data) so CPU always has one to execute A subset of total jobs in system is kept in memory One job selected and run via job scheduling When it has to wait (for I/O for example), OS switches to another job Timesharing (multitasking) is logical extension in which CPU switches jobs so frequently that users can interact with each job while it is running, creating interactive computing Response time should be < 1 second Each user has at least one program executing in memory process If several jobs ready to run at the same time CPU scheduling If processes don’t fit in memory, swapping moves them in and out to run Virtual memory allows execution of processes not completely in memory
32.
1.32 Silberschatz, Galvin
and Gagne ©2018 Operating System Concepts – 10th Edition Operating-System Operations Interrupt driven by hardware Software error or request creates exception or trap Division by zero, request for operating system service Other process problems include infinite loop, processes modifying each other or the operating system Dual-mode operation allows OS to protect itself and other system components User mode and kernel mode Mode bit provided by hardware Provides ability to distinguish when system is running user code or kernel code Some instructions designated as privileged, only executable in kernel mode System call changes mode to kernel, return from call resets it to user
33.
1.33 Silberschatz, Galvin
and Gagne ©2018 Operating System Concepts – 10th Edition Transition from User to Kernel Mode Timer to prevent infinite loop / process hogging resources Set interrupt after specific period Operating system decrements counter (or hardware) When counter zero generate an interrupt Set up before scheduling process to regain control or terminate program that exceeds allotted time
34.
1.34 Silberschatz, Galvin
and Gagne ©2018 Operating System Concepts – 10th Edition Process Management A process is a program in execution. It is a unit of work within the system. Program is a passive entity, process is an active entity. Process needs resources to accomplish its task CPU, memory, I/O, files Initialization data Process termination requires reclaim of any reusable resources Single-threaded process has one program counter specifying location of next instruction to execute Process executes instructions sequentially, one at a time, until completion Multi-threaded process has one program counter per thread Typically system has many processes, some user, some operating system running concurrently on one or more CPUs Concurrency by multiplexing the CPUs among the processes / threads
35.
1.35 Silberschatz, Galvin
and Gagne ©2018 Operating System Concepts – 10th Edition Process Management Activities Creating and deleting both user and system processes Suspending and resuming processes Providing mechanisms for process synchronization Providing mechanisms for process communication Providing mechanisms for deadlock handling The operating system is responsible for the following activities in connection with process management:
36.
1.36 Silberschatz, Galvin
and Gagne ©2018 Operating System Concepts – 10th Edition Memory Management All data in memory before and after processing All instructions in memory in order to execute Memory management determines what is in memory when Optimizing CPU utilization and computer response to users Memory management activities Keeping track of which parts of memory are currently being used and by whom Deciding which processes (or parts thereof) and data to move into and out of memory Allocating and deallocating memory space as needed
37.
1.37 Silberschatz, Galvin
and Gagne ©2018 Operating System Concepts – 10th Edition Storage Management OS provides uniform, logical view of information storage Abstracts physical properties to logical storage unit - file Each medium is controlled by a device (i.e., disk drive, tape drive) Varying properties include access speed, capacity, data- transfer rate, access method (sequential or random) File-System management Files usually organized into directories Access control on most systems to determine who can access what OS activities include Creating and deleting files and directories Primitives to manipulate files and dirs Mapping files onto secondary storage Backup files onto stable (non-volatile) storage media
38.
1.38 Silberschatz, Galvin
and Gagne ©2018 Operating System Concepts – 10th Edition Mass-Storage Management Usually disks used to store data that does not fit in main memory or data that must be kept for a “long” period of time Proper management is of central importance Entire speed of computer operation hinges on disk subsystem and its algorithms OS activities Free-space management Storage allocation Disk scheduling Some storage need not be fast Tertiary storage includes optical storage, magnetic tape Still must be managed – by OS or applications Varies between WORM (write-once, read-many-times) and RW (read-write)
39.
1.39 Silberschatz, Galvin
and Gagne ©2018 Operating System Concepts – 10th Edition Characteristics of Various Types of Storage Movement between levels of storage hierarchy can be explicit or implicit
40.
1.40 Silberschatz, Galvin
and Gagne ©2018 Operating System Concepts – 10th Edition Migration of Integer A from Disk to Register Multitasking environments must be careful to use most recent value, no matter where it is stored in the storage hierarchy Multiprocessor environment must provide cache coherency in hardware such that all CPUs have the most recent value in their cache Distributed environment situation even more complex Several copies of a datum can exist Various solutions covered in Chapter 17
41.
1.41 Silberschatz, Galvin
and Gagne ©2018 Operating System Concepts – 10th Edition I/O Subsystem One purpose of OS is to hide peculiarities of hardware devices from the user I/O subsystem responsible for Memory management of I/O including buffering (storing data temporarily while it is being transferred), caching (storing parts of data in faster storage for performance), spooling (the overlapping of output of one job with input of other jobs) General device-driver interface Drivers for specific hardware devices
42.
1.42 Silberschatz, Galvin
and Gagne ©2018 Operating System Concepts – 10th Edition Protection and Security Protection – any mechanism for controlling access of processes or users to resources defined by the OS Security – defense of the system against internal and external attacks Huge range, including denial-of-service, worms, viruses, identity theft, theft of service Systems generally first distinguish among users, to determine who can do what User identities (user IDs, security IDs) include name and associated number, one per user User ID then associated with all files, processes of that user to determine access control Group identifier (group ID) allows set of users to be defined and controls managed, then also associated with each process, file Privilege escalation allows user to change to effective ID with more rights
43.
1.43 Silberschatz, Galvin
and Gagne ©2018 Operating System Concepts – 10th Edition Special-Purpose Systems Real-time embedded systems most prevalent form of computers Vary considerable, special purpose, limited purpose OS, real-time OS Multimedia systems Streams of data must be delivered according to time restrictions Handheld systems PDAs, smart phones, limited CPU, memory, power Reduced feature set OS, limited I/O
44.
1.44 Silberschatz, Galvin
and Gagne ©2018 Operating System Concepts – 10th Edition Web-Based Computing Web has become ubiquitous PCs, laptops, smartphones, tablets are client devices New category of devices to manage web traffic among similar servers: load balancers Windows, Linux, IOS, Android at the client side Windows, Linux, Unix variants at the server side.
45.
1.45 Silberschatz, Galvin
and Gagne ©2018 Operating System Concepts – 10th Edition Computing Environments (Cont.) • Three Tier Model • Servers in a Central Place in a Data Centre • Clients access the servers through the internet • Servers in two tiers – Application servers, database servers. • Cloud Computing • Servers distributed across one of more data centre • A data centre provides servers to multiple organisations • Servers on rent • Virtualisation • Virtual servers, storage, bandwidth etc. • Virtual resources offered on rent • One server can host multiple virtual servers • Virtualisation Operating System and Guest Operating Systems
46.
1.46 Silberschatz, Galvin
and Gagne ©2018 Operating System Concepts – 10th Edition Virtualization Allows operating systems to run applications within other OSes Vast and growing industry Emulation used when source CPU type different from target type (i.e. PowerPC to Intel x86) Generally slowest method When computer language not compiled to native code – Interpretation Virtualization – OS natively compiled for CPU, running guest OSes also natively compiled Consider VMware running WinXP guests, each running applications, all on native WinXP host OS VMM (virtual machine Manager) provides virtualization services
47.
1.47 Silberschatz, Galvin
and Gagne ©2018 Operating System Concepts – 10th Edition Virtualization (cont.) Use cases involve laptops and desktops running multiple OSes for exploration or compatibility Apple laptop running Mac OS X host, Windows as a guest Developing apps for multiple OSes without having multiple systems Quality assurance testing applications without having multiple systems Executing and managing compute environments within data centers VMM can run natively, in which case they are also the host There is no general-purpose host then (VMware ESX and Citrix XenServer)
48.
1.48 Silberschatz, Galvin
and Gagne ©2018 Operating System Concepts – 10th Edition Computing Environments - Virtualization
49.
1.49 Silberschatz, Galvin
and Gagne ©2018 Operating System Concepts – 10th Edition Android Architecture
50.
1.50 Silberschatz, Galvin
and Gagne ©2018 Operating System Concepts – 10th Edition Example of System Calls System call sequence to copy the contents of one file to another file
51.
1.51 Silberschatz, Galvin
and Gagne ©2018 Operating System Concepts – 10th Edition Example of Standard API Consider the ReadFile() function in the Win32 API—a function for reading from a file A description of the parameters passed to ReadFile() HANDLE file—the file to be read LPVOID buffer—a buffer where the data will be read into and written from DWORD bytesToRead—the number of bytes to be read into the buffer LPDWORD bytesRead—the number of bytes read during the last read LPOVERLAPPED ovl—indicates if overlapped I/O is being used
52.
1.52 Silberschatz, Galvin
and Gagne ©2018 Operating System Concepts – 10th Edition System Call Implementation Typically, a number associated with each system call System-call interface maintains a table indexed according to these numbers The system call interface invokes intended system call in OS kernel and returns status of the system call and any return values The caller need know nothing about how the system call is implemented Just needs to obey API and understand what OS will do as a result call Most details of OS interface hidden from programmer by API Managed by run-time support library (set of functions built into libraries included with compiler)
53.
1.53 Silberschatz, Galvin
and Gagne ©2018 Operating System Concepts – 10th Edition API – System Call – OS Relationship
54.
1.54 Silberschatz, Galvin
and Gagne ©2018 Operating System Concepts – 10th Edition Standard C Library Example C program invoking printf() library call, which calls write() system call
55.
1.55 Silberschatz, Galvin
and Gagne ©2018 Operating System Concepts – 10th Edition System Call Parameter Passing Often, more information is required than simply identity of desired system call Exact type and amount of information vary according to OS and call Three general methods used to pass parameters to the OS Simplest: pass the parameters in registers In some cases, may be more parameters than registers Parameters stored in a block, or table, in memory, and address of block passed as a parameter in a register This approach taken by Linux and Solaris Parameters placed, or pushed, onto the stack by the program and popped off the stack by the operating system Block and stack methods do not limit the number or length of parameters being passed
56.
1.56 Silberschatz, Galvin
and Gagne ©2018 Operating System Concepts – 10th Edition Parameter Passing via Table
57.
1.57 Silberschatz, Galvin
and Gagne ©2018 Operating System Concepts – 10th Edition Types of System Calls Process control end, abort load, execute create process, terminate process get process attributes, set process attributes wait for time wait event, signal event allocate and free memory File management create file, delete file open, close file read, write, reposition get and set file attributes
58.
1.58 Silberschatz, Galvin
and Gagne ©2018 Operating System Concepts – 10th Edition Types of System Calls (Cont.) Device management request device, release device read, write, reposition get device attributes, set device attributes logically attach or detach devices Information maintenance get time or date, set time or date get system data, set system data get and set process, file, or device attributes Communications create, delete communication connection send, receive messages transfer status information attach and detach remote devices
59.
1.59 Silberschatz, Galvin
and Gagne ©2018 Operating System Concepts – 10th Edition Examples of Windows and Unix System Calls
60.
Silberschatz, Galvin and
Gagne ©2018 Operating System Concepts -10th Edition End of Chapter 1 & 2
Download now