The document discusses process management in operating systems. It describes the different states a process can be in, including running, ready, blocked, new, and exit. It also describes process control blocks that contain information about each process like its ID, state, and memory locations. Context switches involve saving the current process context, updating process control blocks, and restoring the context of the next process.
Operating system 18 process creation and terminationVaibhav Khanna
Information associated with each process
(also called task control block)
Process state – running, waiting, etc
Program counter – location of instruction to next execute
CPU registers – contents of all process-centric registers
CPU scheduling information- priorities, scheduling queue pointers
Memory-management information – memory allocated to the process
Accounting information – CPU used, clock time elapsed since start, time limits
I/O status information – I/O devices allocated to process, list of open files
Concept of processes, process scheduling, operations on processes, inter-process communication,
communication in Client-Server-Systems, overview & benefits of threads.
Operation “Blue Star” is the only event in the history of Independent India where the state went into war with its own people. Even after about 40 years it is not clear if it was culmination of states anger over people of the region, a political game of power or start of dictatorial chapter in the democratic setup.
The people of Punjab felt alienated from main stream due to denial of their just demands during a long democratic struggle since independence. As it happen all over the word, it led to militant struggle with great loss of lives of military, police and civilian personnel. Killing of Indira Gandhi and massacre of innocent Sikhs in Delhi and other India cities was also associated with this movement.
Operating system 18 process creation and terminationVaibhav Khanna
Information associated with each process
(also called task control block)
Process state – running, waiting, etc
Program counter – location of instruction to next execute
CPU registers – contents of all process-centric registers
CPU scheduling information- priorities, scheduling queue pointers
Memory-management information – memory allocated to the process
Accounting information – CPU used, clock time elapsed since start, time limits
I/O status information – I/O devices allocated to process, list of open files
Concept of processes, process scheduling, operations on processes, inter-process communication,
communication in Client-Server-Systems, overview & benefits of threads.
Operation “Blue Star” is the only event in the history of Independent India where the state went into war with its own people. Even after about 40 years it is not clear if it was culmination of states anger over people of the region, a political game of power or start of dictatorial chapter in the democratic setup.
The people of Punjab felt alienated from main stream due to denial of their just demands during a long democratic struggle since independence. As it happen all over the word, it led to militant struggle with great loss of lives of military, police and civilian personnel. Killing of Indira Gandhi and massacre of innocent Sikhs in Delhi and other India cities was also associated with this movement.
Macroeconomics- Movie Location
This will be used as part of your Personal Professional Portfolio once graded.
Objective:
Prepare a presentation or a paper using research, basic comparative analysis, data organization and application of economic information. You will make an informed assessment of an economic climate outside of the United States to accomplish an entertainment industry objective.
The French Revolution, which began in 1789, was a period of radical social and political upheaval in France. It marked the decline of absolute monarchies, the rise of secular and democratic republics, and the eventual rise of Napoleon Bonaparte. This revolutionary period is crucial in understanding the transition from feudalism to modernity in Europe.
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June 3, 2024 Anti-Semitism Letter Sent to MIT President Kornbluth and MIT Cor...Levi Shapiro
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Dear Dr. Kornbluth and Mr. Gorenberg,
The US House of Representatives is deeply concerned by ongoing and pervasive acts of antisemitic
harassment and intimidation at the Massachusetts Institute of Technology (MIT). Failing to act decisively to ensure a safe learning environment for all students would be a grave dereliction of your responsibilities as President of MIT and Chair of the MIT Corporation.
This Congress will not stand idly by and allow an environment hostile to Jewish students to persist. The House believes that your institution is in violation of Title VI of the Civil Rights Act, and the inability or
unwillingness to rectify this violation through action requires accountability.
Postsecondary education is a unique opportunity for students to learn and have their ideas and beliefs challenged. However, universities receiving hundreds of millions of federal funds annually have denied
students that opportunity and have been hijacked to become venues for the promotion of terrorism, antisemitic harassment and intimidation, unlawful encampments, and in some cases, assaults and riots.
The House of Representatives will not countenance the use of federal funds to indoctrinate students into hateful, antisemitic, anti-American supporters of terrorism. Investigations into campus antisemitism by the Committee on Education and the Workforce and the Committee on Ways and Means have been expanded into a Congress-wide probe across all relevant jurisdictions to address this national crisis. The undersigned Committees will conduct oversight into the use of federal funds at MIT and its learning environment under authorities granted to each Committee.
• The Committee on Education and the Workforce has been investigating your institution since December 7, 2023. The Committee has broad jurisdiction over postsecondary education, including its compliance with Title VI of the Civil Rights Act, campus safety concerns over disruptions to the learning environment, and the awarding of federal student aid under the Higher Education Act.
• The Committee on Oversight and Accountability is investigating the sources of funding and other support flowing to groups espousing pro-Hamas propaganda and engaged in antisemitic harassment and intimidation of students. The Committee on Oversight and Accountability is the principal oversight committee of the US House of Representatives and has broad authority to investigate “any matter” at “any time” under House Rule X.
• The Committee on Ways and Means has been investigating several universities since November 15, 2023, when the Committee held a hearing entitled From Ivory Towers to Dark Corners: Investigating the Nexus Between Antisemitism, Tax-Exempt Universities, and Terror Financing. The Committee followed the hearing with letters to those institutions on January 10, 202
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2. Announcements
• Accounts on linuxlab.cs.umd.edu
• Newsgroup will be announced shortly
• Project will be posted Wednesday, Sept
18, noon, due on Oct 2,11:59 am.
• HW0 is due Wedensday, Sept 18, 11:59
am by e-mail to liaomay@cs
• Next recitation: Unix process API
• Next homework will be posted next
Wednesday, Sept 25, due on Oct 9.
3. Major Requirements of an
Operating System
• Interleave the execution of several
processes to maximize processor
utilization while providing reasonable
response time
• Allocate resources to processes
• Support interprocess communication and
user creation of processes
4. Process
• Also called a task
• Execution of an individual program
• Can be traced
– list the sequence of instructions that execute
10. Process Creation
• Submission of a batch job
• User logs on
• Created to provide a service such as
printing
• Process creates another process
11. Process Termination
• Batch job issues Halt instruction
• User logs off
• Quit an application
• Error and fault conditions
12. Reasons for Process
Termination
• Normal completion
• Time limit exceeded
• Memory unavailable
• Bounds violation
• Protection error
– example write to read-only file
• Arithmetic error
• Time overrun
– process waited longer than a specified maximum
for an event
13. Reasons for Process
Termination
• I/O failure
• Invalid instruction
– happens when try to execute data
• Privileged instruction
• Data misuse
• Operating system intervention
– such as when deadlock occurs
• Parent terminates so child processes terminate
• Parent request
14. Processes
• Not-running
– ready to execute
• Blocked
– waiting for I/O
• Dispatcher cannot just select the process
that has been in the queue the longest
because it may be blocked
20. Suspended Processes
• Processor is faster than I/O so all
processes could be waiting for I/O
• Swap these processes to disk to free up
more memory
• Blocked state becomes suspend state
when swapped to disk
• Two new states
– Blocked, suspend
– Ready, suspend
25. Operating System Control
Structures
• Information about the current status of
each process and resource
• Tables are constructed for each entity the
operating system manages
26. Memory Tables
• Allocation of main memory to processes
• Allocation of secondary memory to
processes
• Protection attributes for access to shared
memory regions
• Information needed to manage virtual
memory
27. I/O Tables
• I/O device is available or assigned
• Status of I/O operation
• Location in main memory being used as
the source or destination of the I/O
transfer
28. File Tables
• Existence of files
• Location on secondary memory
• Current Status
• Attributes
• Sometimes this information is
maintained by a file-management system
29. Process Table
• Where process is located
• Attributes necessary for its management
– Process ID
– Process state
– Location in memory
30. Process Location
• Process includes set of programs to be
executed
– Data locations for local and global variables
– Any defined constants
– Stack
• Process control block
– Collection of attributes
• Process image
– Collection of program, data, stack, and attributes
31.
32. Process Control Block
• Process identification
– Identifiers
• Numeric identifiers that may be stored with the
process control block include
• Identifier of this process
• Identifier of the process that created this process
(parent process)
• User identifier
33. Process Control Block
• Processor State Information
– User-Visible Registers
• A user-visible register is one that may be
referenced by means of the machine language
that the processor executes. Typically, there are
from 8 to 32 of these registers, although some
RISC implementations have over 100.
34. Process Control Block
• Processor State Information
– Control and Status Registers
These are a variety of processor registers that are
employed to control the operation of the processor. These
include
• •Program counter: Contains the address of the next
instruction to be fetched
• •Condition codes: Result of the most recent arithmetic or
logical operation (e.g., sign, zero, carry, equal, overflow)
•Status information: Includes interrupt enabled/disabled
flags, execution mode
35. Process Control Block
• Processor State Information
– Stack Pointers
• Each process has one or more last-in-first-out
(LIFO) system stacks associated with it. A stack
is used to store parameters and calling addresses
for procedure and system calls. The stack
pointer points to the top of the stack.
36. Process Control Block
• Process Control Information
– Scheduling and State Information
This is information that is needed by the operating system to
perform its scheduling function. Typical items of
information:
•Process state: defines the readiness of the process to be
scheduled for execution (e.g., running, ready, waiting,
halted).
••Priority: One or more fields may be used to describe the
scheduling priority of the process. In some systems, several
values are required (e.g., default, current, highest-allowable)
••Scheduling-related information: This will depend on the
scheduling algorithm used. Examples are the amount of time
that the process has been waiting and the amount of time
that the process executed the last time it was running.
•Event: Identity of event the process is awaiting before it can
be resumed
37. Process Control Block
• Process Control Information
– Data Structuring
• A process may be linked to other process in a
queue, ring, or some other structure. For
example, all processes in a waiting state for a
particular priority level may be linked in a
queue. A process may exhibit a parent-child
(creator-created) relationship with another
process. The process control block may contain
pointers to other processes to support these
structures.
38. Process Control Block
• Process Control Information
– Interprocess Communication
• Various flags, signals, and messages may be associated
with communication between two independent processes.
Some or all of this information may be maintained in the
process control block.
– Process Privileges
• Processes are granted privileges in terms of the memory
that may be accessed and the types of instructions that
may be executed. In addition, privileges may apply to the
use of system utilities and services.
39. Process Control Block
• Process Control Information
– Memory Management
• This section may include pointers to segment
and/or page tables that describe the virtual
memory assigned to this process.
– Resource Ownership and Utilization
• Resources controlled by the process may be
indicated, such as opened files. A history of
utilization of the processor or other resources
may also be included; this information may be
needed by the scheduler.
40.
41. Processor State Information
• Contents of processor registers
– User-visible registers
– Control and status registers
– Stack pointers
• Program status word (PSW)
– contains status information
– Example: the EFLAGS register on Pentium
machines
43. Modes of Execution
• User mode
– Less-privileged mode
– User programs typically execute in this
mode
• System mode, control mode, or kernel
mode
– More-privileged mode
– Kernel of the operating system
44. Process Creation
• Assign a unique process identifier
• Allocate space for the process
• Initialize process control block
• Set up appropriate linkages
– Ex: add new process to linked list used for
scheduling queue
• Create of expand other data structures
– Ex: maintain an accounting file
45. When to Switch a Process
• Clock interrupt
– process has executed for the maximum
allowable time slice
• I/O interrupt
• Memory fault
– memory address is in virtual memory so it
must be brought into main memory
46. When to Switch a Process
• Trap
– error occurred
– may cause process to be moved to Exit state
• Supervisor call
– such as file open
47. Change of Process State
• Save context of processor including
program counter and other registers
• Update the process control block of the
process that is currently running
• Move process control block to
appropriate queue - ready, blocked
• Select another process for execution
48. Change of Process State
• Update the process control block of the
process selected
• Update memory-management data
structures
• Restore context of the selected process
49. Execution of the Operating
System
• Non-process Kernel
– execute kernel outside of any process
– operating system code is executed as a
separate entity that operates in privileged
mode
• Execution Within User Processes
– operating system software within context of
a user process
– process executes in privileged mode when
executing operating system code
50.
51. Execution of the Operating
System
• Process-Based Operating System
– major kernel functions are separate
processes
– Useful in multi-processor or multi-
computer environment