5. CPU Scheduling
... There is a choice, however, in circumstances 2 and 3. The old processes again could be placed on CPU to continue the work immediately independent of the other ready processes. When scheduling (placing on CPU new different job) takes place only under circumstances 1 and 4, we say the scheduling schem ...
... There is a choice, however, in circumstances 2 and 3. The old processes again could be placed on CPU to continue the work immediately independent of the other ready processes. When scheduling (placing on CPU new different job) takes place only under circumstances 1 and 4, we say the scheduling schem ...
![[slides] Case study: Linux](http://s1.studyres.com/store/data/008426094_1-33a53a235a0b160ad065c81f93e7bd9c-300x300.png)
[slides] Case study: Linux
... about to be returned to user mode 2. The second technique applies to critical sections that occur in an interrupt service routines – By using the processor’s interrupt control hardware to disable interrupts during a critical section, the kernel guarantees that it can proceed without the risk of conc ...
... about to be returned to user mode 2. The second technique applies to critical sections that occur in an interrupt service routines – By using the processor’s interrupt control hardware to disable interrupts during a critical section, the kernel guarantees that it can proceed without the risk of conc ...
Malware defenses (cont)
... • Manually specifying this policy is really difficult: – Systrace can auto-generate policies by learning how an app behaves on “good” inputs – But if policy doesn’t cover specific behavior, not clear how to manage – Difficulty with choosing a policy for a given app is the reason it isn’t more broadl ...
... • Manually specifying this policy is really difficult: – Systrace can auto-generate policies by learning how an app behaves on “good” inputs – But if policy doesn’t cover specific behavior, not clear how to manage – Difficulty with choosing a policy for a given app is the reason it isn’t more broadl ...
Silberschatz, Galvin and Gagne ©2013 Operating System Concepts
... Spooling - hold output for a device ...
... Spooling - hold output for a device ...
3.5 Interprocess Communication
... 2. T/F A blocking send is asynchronous communication. 3. What mechanism is used popularly for implementing message passing? 4. In Unix, if a parent process wants to create a child process and then wait till the child complete, what are the system calls involved? 5. We have seen two concepts: process ...
... 2. T/F A blocking send is asynchronous communication. 3. What mechanism is used popularly for implementing message passing? 4. In Unix, if a parent process wants to create a child process and then wait till the child complete, what are the system calls involved? 5. We have seen two concepts: process ...
Chapter 1 Operating System Overview
... waiting for the use of an I/O device, the operating system may wish to schedule that process for execution as soon as possible in order to free up the device for later demands from other processes. ٭Efficiency: Maximize throughput(吞吐量), minimize response time, accommodate（容纳） as many users as pos ...
... waiting for the use of an I/O device, the operating system may wish to schedule that process for execution as soon as possible in order to free up the device for later demands from other processes. ٭Efficiency: Maximize throughput(吞吐量), minimize response time, accommodate（容纳） as many users as pos ...
Public Solutions System - Kitchen Table Democracy
... enforce policy to solve problems. Today, accelerating change, entrenched and overlapping political jurisdictions, and far more complex problems require a better operating system to meet our public challenges. This is not a matter of government reform, but of better "governance" — the combined effort ...
... enforce policy to solve problems. Today, accelerating change, entrenched and overlapping political jurisdictions, and far more complex problems require a better operating system to meet our public challenges. This is not a matter of government reform, but of better "governance" — the combined effort ...
3 MB 3rd Nov 2014 ch1
... Process needs resources to accomplish its task CPU, memory, I/O, files (received upon creation and along execution) Initialization data (e.g., a process for presenting the status of a file) Process termination requires reclaim of any reusable resources ...
... Process needs resources to accomplish its task CPU, memory, I/O, files (received upon creation and along execution) Initialization data (e.g., a process for presenting the status of a file) Process termination requires reclaim of any reusable resources ...
Slides - CSE, IIT Bombay
... Some resources cannot be shared across processes; they must be used by only one process at a time – If a resource is in use by a process, another process wishing to use the resource must wait for the process to release it * Indefinite waits would arise if processes wait for each other This situati ...
... Some resources cannot be shared across processes; they must be used by only one process at a time – If a resource is in use by a process, another process wishing to use the resource must wait for the process to release it * Indefinite waits would arise if processes wait for each other This situati ...
Messenger-Based Operating Systems - (CUI)
... the viewpoint of a user process, invisible: what for the user thread is a trap, segment violation or an ordinary termination, becomes for the messenger the end of the execution request. It depends on the controlling messenger what comes next. It is possible to implement operating system functionalit ...
... the viewpoint of a user process, invisible: what for the user thread is a trap, segment violation or an ordinary termination, becomes for the messenger the end of the execution request. It depends on the controlling messenger what comes next. It is possible to implement operating system functionalit ...
Process Management - Computer Science
... disable interrupt checking check whether current thread has run “long enough” if yes, post asynchronous software trap (AST) enable interrupt checking exit interrupt handler enter “return-to-user” code check whether AST was posted if not, restore user thread state and return to executin ...
... disable interrupt checking check whether current thread has run “long enough” if yes, post asynchronous software trap (AST) enable interrupt checking exit interrupt handler enter “return-to-user” code check whether AST was posted if not, restore user thread state and return to executin ...
File - BS
... A process is a program in execution (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 (received upon creation and along execution) Initialization data (e.g., a process for present ...
... A process is a program in execution (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 (received upon creation and along execution) Initialization data (e.g., a process for present ...
Computer system structure overview
... Typically stored in ROM or EPROM, generally known as firmware Initializes all aspects of system Loads operating system kernel and starts execution OS starts executing the first process “init” and waits for some events ...
... Typically stored in ROM or EPROM, generally known as firmware Initializes all aspects of system Loads operating system kernel and starts execution OS starts executing the first process “init” and waits for some events ...
Implementing Processes, Threads, and Resources
... Process Manager • In a multi-programmed OS, several processes can be “executed at the same time”. • The Process Manager is that part of the OS that is responsible for managing all the processes on the system. • When the computer is powered on, there is only one program in execution: the initial proc ...
... Process Manager • In a multi-programmed OS, several processes can be “executed at the same time”. • The Process Manager is that part of the OS that is responsible for managing all the processes on the system. • When the computer is powered on, there is only one program in execution: the initial proc ...
Steps of porting (cont
... A kernel needs to provide root services for other parts in system Kernel also have to manage hardware and allocate system resources Sometimes a kernel can be explained as ‘supervisor of OS’ or ‘core’ ...
... A kernel needs to provide root services for other parts in system Kernel also have to manage hardware and allocate system resources Sometimes a kernel can be explained as ‘supervisor of OS’ or ‘core’ ...
Faithful Virtualization on a Real
... the VMM that keeps entering and leaving the guest mode with a couple of conditions that increase the mode switch duration. In this scenario the VMM enters the guest mode injecting an exception and flushing the tagged TLBs. The guest’s stack pointer is prepared in a way that the CPU needs to access t ...
... the VMM that keeps entering and leaving the guest mode with a couple of conditions that increase the mode switch duration. In this scenario the VMM enters the guest mode injecting an exception and flushing the tagged TLBs. The guest’s stack pointer is prepared in a way that the CPU needs to access t ...
No Slide Title
... 1. Normal kernel code is nonpreemptible (until 2.4) – when a time interrupt is received while a process is executing a kernel system service routine, the kernel’s need_resched flag is set so that the scheduler will run once the system call has completed and control is about to be returned to user mo ...
... 1. Normal kernel code is nonpreemptible (until 2.4) – when a time interrupt is received while a process is executing a kernel system service routine, the kernel’s need_resched flag is set so that the scheduler will run once the system call has completed and control is about to be returned to user mo ...
The Linux System 21.2 Silberschatz, Galvin and Gagne ©2009
... 1. Normal kernel code is nonpreemptible (until 2.4) – when a time interrupt is received while a process is executing a kernel system service routine, the kernel’s need_resched flag is set so that the scheduler will run once the system call has completed and control is about to be returned to user mo ...
... 1. Normal kernel code is nonpreemptible (until 2.4) – when a time interrupt is received while a process is executing a kernel system service routine, the kernel’s need_resched flag is set so that the scheduler will run once the system call has completed and control is about to be returned to user mo ...
Interlude: Process API - Computer Sciences User Pages
... call, which the OS provides as a way to create a new process. The odd part: the process that is created is an (almost) exact copy of the calling process. That means that to the OS, it now looks like there are two copies of the program p1 running, and both are about to return from the fork() system c ...
... call, which the OS provides as a way to create a new process. The odd part: the process that is created is an (almost) exact copy of the calling process. That means that to the OS, it now looks like there are two copies of the program p1 running, and both are about to return from the fork() system c ...
The Linux System
... about to be returned to user mode 2. The second technique applies to critical sections that occur in an interrupt service routines – By using the processor’s interrupt control hardware to disable interrupts during a critical section, the kernel guarantees that it can proceed without the risk of conc ...
... about to be returned to user mode 2. The second technique applies to critical sections that occur in an interrupt service routines – By using the processor’s interrupt control hardware to disable interrupts during a critical section, the kernel guarantees that it can proceed without the risk of conc ...
2.01 - Faculty of Computer Science and Information Technology
... Silberschatz, Galvin and Gagne ©2005 ...
... Silberschatz, Galvin and Gagne ©2005 ...
Operating System Concepts
... Open File descriptor table PCB (Process Control Block) For a thread creation, only need to allocate CPU context and Stack !! ...
... Open File descriptor table PCB (Process Control Block) For a thread creation, only need to allocate CPU context and Stack !! ...