1 Interfacing I/O devices to the Memory, Processor, and Operating
... • These memory addresses are not directly accessible to user programs ...
... • These memory addresses are not directly accessible to user programs ...
PPT - LSU CCT - Louisiana State University
... state of the old process and loading the saved state of the new process, this task is called Context Switch. • The context of a process is represented in the PCB of a process; it includes value of CPU registers, process state and memory management information. • When a context switch occurs, the ker ...
... state of the old process and loading the saved state of the new process, this task is called Context Switch. • The context of a process is represented in the PCB of a process; it includes value of CPU registers, process state and memory management information. • When a context switch occurs, the ker ...
CS311 Introduction to Operating Systems I - Summer 2009
... • Explain why multiprogramming and timesharing are important for modern operating systems. • Reproduce the diagram of the organization of Unix. • Describe the memory organization of a typical process in a common operating system. • What is a context switch? – Ans: It is when a process is switched ou ...
... • Explain why multiprogramming and timesharing are important for modern operating systems. • Reproduce the diagram of the organization of Unix. • Describe the memory organization of a typical process in a common operating system. • What is a context switch? – Ans: It is when a process is switched ou ...
Operating Systems - bu people
... The biggest disadvantage of a non preemptive kernel is task responsiveness. This is because a high priority task is made to wait until the current task (even if of a lower priority) has finished execution Interrupts can preempt a task, however even if a higher priority task is scheduled within an in ...
... The biggest disadvantage of a non preemptive kernel is task responsiveness. This is because a high priority task is made to wait until the current task (even if of a lower priority) has finished execution Interrupts can preempt a task, however even if a higher priority task is scheduled within an in ...
What is an Operating System?
... OS Responsibilities with Respect to I/O Devices • If the user (who activated the program) can only read the file, but not write on it ...the OS needs to ensure the program can only use the appropriate functionality of the I/O device • The OS does not allow the program to directly access the device ...
... OS Responsibilities with Respect to I/O Devices • If the user (who activated the program) can only read the file, but not write on it ...the OS needs to ensure the program can only use the appropriate functionality of the I/O device • The OS does not allow the program to directly access the device ...
General-purpose Process Migration
... effects are identical on the source and target nodes, to the extent detectable by the process, relies on a three-step procedure: First, figure out all the side effect the process has had on the operating system and recreate these effects after the process has moved to a different operating system. S ...
... effects are identical on the source and target nodes, to the extent detectable by the process, relies on a three-step procedure: First, figure out all the side effect the process has had on the operating system and recreate these effects after the process has moved to a different operating system. S ...
Synchronization - William & Mary Computer Science
... Can take resource away, give it back later Resource has little state associated with it May only have one of this resource Example: CPU OS management: scheduling – Decide order in which requests are serviced – Decide how long process keeps resource ...
... Can take resource away, give it back later Resource has little state associated with it May only have one of this resource Example: CPU OS management: scheduling – Decide order in which requests are serviced – Decide how long process keeps resource ...
Lecture 15 - NCSU COE People
... processes may be resident simultaneously in main memory. • The processor “takes turns” working on each one. • But some processes may be idle for a “long time” (if, e.g., the user walks away from his terminal). Such processes “waste space” in memory that could better be used by other processes. So th ...
... processes may be resident simultaneously in main memory. • The processor “takes turns” working on each one. • But some processes may be idle for a “long time” (if, e.g., the user walks away from his terminal). Such processes “waste space” in memory that could better be used by other processes. So th ...
• Chapter 1: Introduction
... • The O.S. picks and begins to execute one job from memory. Once this job needs an I/O operation the O.S. switches to another job (CPU or O.S. always busy). ...
... • The O.S. picks and begins to execute one job from memory. Once this job needs an I/O operation the O.S. switches to another job (CPU or O.S. always busy). ...
ppt
... • Each file has owner and group • Permissions set by owner setid – Read, write, execute - rwx rwx rwx – Owner, group, other ownr grp othr – Represented by vector of four octal values • Only owner, root can change permissions – This privilege cannot be delegated or shared • Setid bits – Discuss in a ...
... • Each file has owner and group • Permissions set by owner setid – Read, write, execute - rwx rwx rwx – Owner, group, other ownr grp othr – Represented by vector of four octal values • Only owner, root can change permissions – This privilege cannot be delegated or shared • Setid bits – Discuss in a ...
Shim
... the results of a process, the process return value or other information, to a wrong process. Proposed solution: Overshadow uses its own protected table for the process’s signal handlers and hypercall to ensure that signals are delivered to the correct process. ...
... the results of a process, the process return value or other information, to a wrong process. Proposed solution: Overshadow uses its own protected table for the process’s signal handlers and hypercall to ensure that signals are delivered to the correct process. ...
Chapter 7 Memory Management
... • In contrast, programs are organized into modules – Modules can be written and compiled independently – Different degrees of protection can be given to different modules (read-only, execute-only) – Modules can be shared among processes ...
... • In contrast, programs are organized into modules – Modules can be written and compiled independently – Different degrees of protection can be given to different modules (read-only, execute-only) – Modules can be shared among processes ...
CSNB334 Advanced Operating Systems Course Introduction
... Do your work individually and use the group for first level discussions. All lab solutions need to be demonstrated in the lab. No marks will be given if a lab solution is submitted without giving a ...
... Do your work individually and use the group for first level discussions. All lab solutions need to be demonstrated in the lab. No marks will be given if a lab solution is submitted without giving a ...
Processes - EECG Toronto
... struct proc *p_sibling; /* ptr to next sibling proc on chain */ struct proc *p_psibling; /* ptr to prev sibling proc on chain */ struct proc *p_sibling_ns; /* prt to siblings with new state */ struct proc *p_child_ns; /* prt to children with new state */ ...
... struct proc *p_sibling; /* ptr to next sibling proc on chain */ struct proc *p_psibling; /* ptr to prev sibling proc on chain */ struct proc *p_sibling_ns; /* prt to siblings with new state */ struct proc *p_child_ns; /* prt to children with new state */ ...
ppt - Computer Science
... queues. Performance can be improved by delaying the movement of threads within/between queues until the queues are queried. This ``lazy'' scheduling is achieved by setting state flags (ready / waiting) in the Thread Control Blocks (tcb – contains basic information about a thread) and then scanning q ...
... queues. Performance can be improved by delaying the movement of threads within/between queues until the queues are queried. This ``lazy'' scheduling is achieved by setting state flags (ready / waiting) in the Thread Control Blocks (tcb – contains basic information about a thread) and then scanning q ...
APT 2040: OPERATING SYSTEMS Pre
... provides an understanding of the characteristics and the operating principles of the main hardware components of a computer system. In addition, the course covers the concepts and fundamentals of the operating systems. These fundamentals include process management, memory management, and device mana ...
... provides an understanding of the characteristics and the operating principles of the main hardware components of a computer system. In addition, the course covers the concepts and fundamentals of the operating systems. These fundamentals include process management, memory management, and device mana ...
Processes - Mitra.ac.in
... information that is consumed by a consumer process. Eg. Client Server Paradigm, program execution process Solution is shared memory. Producer and consumer must be synchronized, so that consumer does not try to consume item that has not yet been produce. Two types of buffer can be used unboun ...
... information that is consumed by a consumer process. Eg. Client Server Paradigm, program execution process Solution is shared memory. Producer and consumer must be synchronized, so that consumer does not try to consume item that has not yet been produce. Two types of buffer can be used unboun ...
I/O devices
... • Expected switch to the OS: system call instruction (syscall) – A jump (or function call) to OS code • E.g., in order to perform a disk access • Also similar to a program-initiated exception ...
... • Expected switch to the OS: system call instruction (syscall) – A jump (or function call) to OS code • E.g., in order to perform a disk access • Also similar to a program-initiated exception ...
Chapter 3 - reduced
... wait()system call. The call returns status information and the pid of the terminated process pid = wait(&status); If no parent waiting (did not invoke wait()) process is a zombie ...
... wait()system call. The call returns status information and the pid of the terminated process pid = wait(&status); If no parent waiting (did not invoke wait()) process is a zombie ...
CMPS431 Syllabus, Fall 2009
... Describe how issues such as open source software and the increased use of the Internet are influencing operating system design. Explain the concept of a logical layer. Explain the benefits of building abstract layers in hierarchical fashion. Defend the need for APIs and middleware. Describe how comp ...
... Describe how issues such as open source software and the increased use of the Internet are influencing operating system design. Explain the concept of a logical layer. Explain the benefits of building abstract layers in hierarchical fashion. Defend the need for APIs and middleware. Describe how comp ...
Main Memory
... memory and placed within a process for it to be run • Main memory and registers are only storage CPU can access directly • Register access in one CPU clock (or less) • Main memory can take many cycles • Cache sits between main memory and ...
... memory and placed within a process for it to be run • Main memory and registers are only storage CPU can access directly • Register access in one CPU clock (or less) • Main memory can take many cycles • Cache sits between main memory and ...
1999 - 2000
... allowed the CPU to be used much more effectively. When one job had to wait for an I/O request, another program could use the CPU. The concept of multiprogramming led to a need for a more complex operating system. One was now needed that could schedule tasks and deal with all the problems that this b ...
... allowed the CPU to be used much more effectively. When one job had to wait for an I/O request, another program could use the CPU. The concept of multiprogramming led to a need for a more complex operating system. One was now needed that could schedule tasks and deal with all the problems that this b ...
No Slide Title
... Pre-emptive multitasking: Processes are given some time on the processor. This allows all the processes to have some time on the processor, and makes for smoother and more reliable operation ...
... Pre-emptive multitasking: Processes are given some time on the processor. This allows all the processes to have some time on the processor, and makes for smoother and more reliable operation ...
Subject : OPS - 12178 Chapter 4 Process Scheduling Scheduling
... Basic Concepts: - In a single-processor system, only one process can run at a time; any others must wait until the CPU is free and can be rescheduled. The objective of multiprogramming is to have some process running at all times, to maximize CPU utilization. The idea is relatively simple. A process ...
... Basic Concepts: - In a single-processor system, only one process can run at a time; any others must wait until the CPU is free and can be rescheduled. The objective of multiprogramming is to have some process running at all times, to maximize CPU utilization. The idea is relatively simple. A process ...