What is Operating System (OS)
... a process. When it executes, it loads instructions and data from memory. Memory also needs to be shared between the processes currently residing in main memory. Because a process can be placed almost anywhere in memory in most systems, it needs some way to reach the information in the memory regardl ...
... a process. When it executes, it loads instructions and data from memory. Memory also needs to be shared between the processes currently residing in main memory. Because a process can be placed almost anywhere in memory in most systems, it needs some way to reach the information in the memory regardl ...
A1_OS Review
... • The status (context) of one process is saved; the status of the second process restored. • Don’t confuse with mode switch, which is done in the context of one process. ...
... • The status (context) of one process is saved; the status of the second process restored. • Don’t confuse with mode switch, which is done in the context of one process. ...
CPSC 457: Principles of Operating Systems Assignment 1 due May
... 1. (5 marks) What is the difference between timesharing and multiprogramming systems? 2. (5 marks) Instructions related to accessing I/O devices typically can be executed in kernel mode but not in user mode. Give a reason why it is better to run these instructions in kernel mode. ...
... 1. (5 marks) What is the difference between timesharing and multiprogramming systems? 2. (5 marks) Instructions related to accessing I/O devices typically can be executed in kernel mode but not in user mode. Give a reason why it is better to run these instructions in kernel mode. ...
Chapter10
... • Sharing IO devices • Main (Primary Memory) Management (Shared among many programs) • Disk (Secondary) Memory) Management (More sharing) ...
... • Sharing IO devices • Main (Primary Memory) Management (Shared among many programs) • Disk (Secondary) Memory) Management (More sharing) ...
CSc 352: Systems Programming & Unix
... lists the files in a directory one screenful at a time How this works: • ls writes its output to its stdout • more’s input stream defaults to its stdin • the pipe connects ls’s stdout to more’s stdin • the piped commands run “in parallel” ...
... lists the files in a directory one screenful at a time How this works: • ls writes its output to its stdout • more’s input stream defaults to its stdin • the pipe connects ls’s stdout to more’s stdin • the piped commands run “in parallel” ...
Review
... • Integer ‘S’ that (besides init) can only be modified by: – P(S) or S.wait(): decrement or block if already 0 – V(S) or S.signal(): increment and wake up process if any ...
... • Integer ‘S’ that (besides init) can only be modified by: – P(S) or S.wait(): decrement or block if already 0 – V(S) or S.signal(): increment and wake up process if any ...
WORD
... aging a process (as time progresses, increase the priority) In Round Robin, small time quantums can result in large amounts of context switches ◦ Time quantum should be chosen so that 80% of processes have shorter burst times that the time quantum Multilevel Queues and Multilevel Feedback Queues ...
... aging a process (as time progresses, increase the priority) In Round Robin, small time quantums can result in large amounts of context switches ◦ Time quantum should be chosen so that 80% of processes have shorter burst times that the time quantum Multilevel Queues and Multilevel Feedback Queues ...
Study Guide to Accompany Operating Systems Concepts 9 Ed by
... aging a process (as time progresses, increase the priority) • In Round Robin, small time quantums can result in large amounts of context switches ◦ Time quantum should be chosen so that 80% of processes have shorter burst times that the time quantum • Multilevel Queues and Multilevel Feedback Queues ...
... aging a process (as time progresses, increase the priority) • In Round Robin, small time quantums can result in large amounts of context switches ◦ Time quantum should be chosen so that 80% of processes have shorter burst times that the time quantum • Multilevel Queues and Multilevel Feedback Queues ...
doc
... aging a process (as time progresses, increase the priority) In Round Robin, small time quantums can result in large amounts of context switches ◦ Time quantum should be chosen so that 80% of processes have shorter burst times that the time quantum Multilevel Queues and Multilevel Feedback Queues ...
... aging a process (as time progresses, increase the priority) In Round Robin, small time quantums can result in large amounts of context switches ◦ Time quantum should be chosen so that 80% of processes have shorter burst times that the time quantum Multilevel Queues and Multilevel Feedback Queues ...
Process Concept
... only a few milliseconds before waiting for an I/O request. Often the short-term scheduler executes at least once every 100 milliseconds. Because of the brief time between executions, the short-term scheduler must be fast. If it takes 10 milliseconds to decide to execute a process for 100 millisecond ...
... only a few milliseconds before waiting for an I/O request. Often the short-term scheduler executes at least once every 100 milliseconds. Because of the brief time between executions, the short-term scheduler must be fast. If it takes 10 milliseconds to decide to execute a process for 100 millisecond ...
Chapter 2
... With modularity, layers are selected such that each uses functions (operations) and services of only lower-level layers ...
... With modularity, layers are selected such that each uses functions (operations) and services of only lower-level layers ...
Introduction - University of Pennsylvania
... way of accessing all information relevant to a process: This data is either contained directly in the PCB, or else the PCB contains pointers to other system tables. Processes (PCBs) are manipulated by two main components of the OS in order to achieve the effects of multiprogramming: Scheduler: ...
... way of accessing all information relevant to a process: This data is either contained directly in the PCB, or else the PCB contains pointers to other system tables. Processes (PCBs) are manipulated by two main components of the OS in order to achieve the effects of multiprogramming: Scheduler: ...
DOS - InfoShare.tk
... In the 1980s or early 1990s, the operating system that shipped with most PCs was a version of the Disk Operating System (DOS) created by Microsoft: MSDOS. ...
... In the 1980s or early 1990s, the operating system that shipped with most PCs was a version of the Disk Operating System (DOS) created by Microsoft: MSDOS. ...
process
... The computing system define I/O operations as being privileged instructions, accessible only in monitor mode. Because interrupts are the preferred way to solve I/O operations, the interrupt mechanism could of fer the possibility to gain the control over the system by a user process. An interru ...
... The computing system define I/O operations as being privileged instructions, accessible only in monitor mode. Because interrupts are the preferred way to solve I/O operations, the interrupt mechanism could of fer the possibility to gain the control over the system by a user process. An interru ...
Chapter 3: Operating System Structures
... • People use computers for the potential of rapid information processing • There are several measures of performance – throughput – response time • The OS is an overhead function => should not use too much of machine resources • Provide an environment in which programmers can produce solutions in a ...
... • People use computers for the potential of rapid information processing • There are several measures of performance – throughput – response time • The OS is an overhead function => should not use too much of machine resources • Provide an environment in which programmers can produce solutions in a ...
MachOS_Rajesh
... Multiprocessor support for UMA, NUMA, and NORMA architectures The programmer has the option to choose between shared memory and message-based communication Emulation of operating system environment such as UNIX achieved on Mach Generic UNIX system calls can be implemented outside Mach kernel Other f ...
... Multiprocessor support for UMA, NUMA, and NORMA architectures The programmer has the option to choose between shared memory and message-based communication Emulation of operating system environment such as UNIX achieved on Mach Generic UNIX system calls can be implemented outside Mach kernel Other f ...
OPERATING SYSTEM
... Both of these machines are very huge and people need small machines. IBM produced the System/360 to solve these problems. All the machines had the same architecture and instruction set, programs written for one machine could run on all the others. Furthermore, the 360 was designed to handle both sci ...
... Both of these machines are very huge and people need small machines. IBM produced the System/360 to solve these problems. All the machines had the same architecture and instruction set, programs written for one machine could run on all the others. Furthermore, the 360 was designed to handle both sci ...
Process - FmGroup
... MS/DOS, early Macintosh, Batch processing Easier for operating system builder Get rid concurrency by defining it away Does this make sense for personal computers? ...
... MS/DOS, early Macintosh, Batch processing Easier for operating system builder Get rid concurrency by defining it away Does this make sense for personal computers? ...
The OS 215 Project
... GET_TIME_OF_DAY( & ReturnedTime ); Get the time the hardware thinks it is. This is NOT in any normal units like seconds or whatever. Note that following the C convention, we’re passing the ADDRESS of the variable Z502_REG1 (that’s what the “&” does.) Then in the next line printf( "Time of day is %d\ ...
... GET_TIME_OF_DAY( & ReturnedTime ); Get the time the hardware thinks it is. This is NOT in any normal units like seconds or whatever. Note that following the C convention, we’re passing the ADDRESS of the variable Z502_REG1 (that’s what the “&” does.) Then in the next line printf( "Time of day is %d\ ...
Operating Systems
... • Clock time – the amount of time a process takes to run. This depends on the number of other processes being run on the system. Whenever you report the clock time, the measurements should be made with no other activities on the system. • User CPU time – attributed to user instructions. • System CPU ...
... • Clock time – the amount of time a process takes to run. This depends on the number of other processes being run on the system. Whenever you report the clock time, the measurements should be made with no other activities on the system. • User CPU time – attributed to user instructions. • System CPU ...
Answer
... The output of a program may need to be written into new files or input taken from some files. The operating systems provides this service. The user does not have to worry about secondary storage management. User gives a command for reading or writing to a file and sees his her task accomplished. Thu ...
... The output of a program may need to be written into new files or input taken from some files. The operating systems provides this service. The user does not have to worry about secondary storage management. User gives a command for reading or writing to a file and sees his her task accomplished. Thu ...
Answers to Even-numbered Exercises
... distributions, such as Ubuntu Linux, include many utilities. You can also download many utilities from the Internet. Examples of utilities are cp (copies a file), ls (lists information about files), ssh (securely connects to a remote computer), and df (lists information about free space on system de ...
... distributions, such as Ubuntu Linux, include many utilities. You can also download many utilities from the Internet. Examples of utilities are cp (copies a file), ls (lists information about files), ssh (securely connects to a remote computer), and df (lists information about free space on system de ...
WORD
... aging a process (as time progresses, increase the priority) In Round Robin, small time quantums can result in large amounts of context switches ◦ Time quantum should be chosen so that 80% of processes have shorter burst times that the time quantum Multilevel Queues and Multilevel Feedback Queues ...
... aging a process (as time progresses, increase the priority) In Round Robin, small time quantums can result in large amounts of context switches ◦ Time quantum should be chosen so that 80% of processes have shorter burst times that the time quantum Multilevel Queues and Multilevel Feedback Queues ...