Chapter 11 I/O Management and Disk Scheduling
... organizing an OS into layers – Each layer performs a related subset of the functions required of OS – Each layer relies on the next lower layer to perform more primitive functions and to conceal the details of those functions – Each layer provides services to the next higher layer – Changes in one l ...
... organizing an OS into layers – Each layer performs a related subset of the functions required of OS – Each layer relies on the next lower layer to perform more primitive functions and to conceal the details of those functions – Each layer provides services to the next higher layer – Changes in one l ...
ICS 143 - Introduction to Operating Systems
... Allows overlap - I/O of one job with computation of another. Introduces notion of a job pool that allows OS choose next job to run so as to increase CPU utilization. ...
... Allows overlap - I/O of one job with computation of another. Introduces notion of a job pool that allows OS choose next job to run so as to increase CPU utilization. ...
Chapter 09: Uniprocessor Scheduling
... – I/O processes have to wait until CPU-bound process completes ...
... – I/O processes have to wait until CPU-bound process completes ...
Mainframe System
... Can be used to handle multiple interactive jobs Processor time is shared among multiple users Multiple users simultaneously access the system through terminals, with the OS interleaving the execution of each user program in a short burst or quantum of computation ...
... Can be used to handle multiple interactive jobs Processor time is shared among multiple users Multiple users simultaneously access the system through terminals, with the OS interleaving the execution of each user program in a short burst or quantum of computation ...
Scheduling Policy and its Performance for the
... Scheduling of tasks It is crucial for the real-time operating system to adapt preemptive scheduling kernel, which is based on task priority. The µC/OS-II operating system uses this method to implement its scheduling. In an operating system with nonpreemptive scheduling mechanism, must have no strict ...
... Scheduling of tasks It is crucial for the real-time operating system to adapt preemptive scheduling kernel, which is based on task priority. The µC/OS-II operating system uses this method to implement its scheduling. In an operating system with nonpreemptive scheduling mechanism, must have no strict ...
CPU Scheduling Algorithms
... It is run for the quantum or until it blocks RR allocates the CPU uniformly (fairly) across participants. If average queue length is n, each participant gets 1/n ...
... It is run for the quantum or until it blocks RR allocates the CPU uniformly (fairly) across participants. If average queue length is n, each participant gets 1/n ...
Colour version (for viewing)
... queue has a priority associated with it. Queues with higher priority can be given more time-slices for each process. Different scheduling algorithms can be used for scheduling within queues. E.g. separate ready-queue in foreground (for interactive processes) and background (for batch processes) qu ...
... queue has a priority associated with it. Queues with higher priority can be given more time-slices for each process. Different scheduling algorithms can be used for scheduling within queues. E.g. separate ready-queue in foreground (for interactive processes) and background (for batch processes) qu ...
Operating Systems Lecture 6 CPU Scheduling Adapted from
... which the most popular operating systems (DOS, Mac) had NO sophisticated CPU scheduling algorithms. They were single threaded and ran one process at a time until the user directs them to run another process. ...
... which the most popular operating systems (DOS, Mac) had NO sophisticated CPU scheduling algorithms. They were single threaded and ran one process at a time until the user directs them to run another process. ...
AIM COLLEGE-HISAR What is an Operating System?
... One way that operating-system designers reduce the chance of thrashing is by reducing the need for new processes to perform various tasks. Some operating systems allow for a "process-lite," called a thread, that can deal with all the CPU-intensive work of a normal process, but generally does not dea ...
... One way that operating-system designers reduce the chance of thrashing is by reducing the need for new processes to perform various tasks. Some operating systems allow for a "process-lite," called a thread, that can deal with all the CPU-intensive work of a normal process, but generally does not dea ...
PowerPoint Format
... file-system context applies to requests to open new files. The current root and default directories to be used for new file searches are stored here. The signal-handler table defines the routine in the process’s address space to be called when specific signals arrive. The virtual-memory context of a ...
... file-system context applies to requests to open new files. The current root and default directories to be used for new file searches are stored here. The signal-handler table defines the routine in the process’s address space to be called when specific signals arrive. The virtual-memory context of a ...
Objectives Process control block (1) Process Control Block (2)
... Kernel saves context (e.g registers, pointers, memory management information etc) into the process’ PCB Loads context of the new process scheduled to ...
... Kernel saves context (e.g registers, pointers, memory management information etc) into the process’ PCB Loads context of the new process scheduled to ...
The SAS System for the UNIX Environment
... The first implementation of the UNIX operating system was written in 1969 as part of a research project at AT&T Bell Labs by Ken Thompson and Dennis Ritchie. It was written in assembler language for a Digital Equipment Corporation (DEC) PDP-7. Frustration with an earlier effort at MIT to write a mul ...
... The first implementation of the UNIX operating system was written in 1969 as part of a research project at AT&T Bell Labs by Ken Thompson and Dennis Ritchie. It was written in assembler language for a Digital Equipment Corporation (DEC) PDP-7. Frustration with an earlier effort at MIT to write a mul ...
Colour version (for viewing)
... memory management information etc) into the process’ PCB Loads context of the new process scheduled to run can become substantial depending on whether parts of memory must be saved too. ...
... memory management information etc) into the process’ PCB Loads context of the new process scheduled to run can become substantial depending on whether parts of memory must be saved too. ...
H 10.1. File-System Interface
... A common technique for implementing file types is to include the type as part of the file name. The name is split into two parts-a name and an extension, usually separated by a period character. In this way, the user and the operating system can tell from the name alone what the type of a file is. F ...
... A common technique for implementing file types is to include the type as part of the file name. The name is split into two parts-a name and an extension, usually separated by a period character. In this way, the user and the operating system can tell from the name alone what the type of a file is. F ...
PPT
... Used to communicate I/O requests and responses For bulk data transfer devices (DMA, network), buffer space allocated out of band by GuestOS Descriptor contains unique identifier to allow out of order processing Multiple requests can be added before hypercall made to begin processing Event notificati ...
... Used to communicate I/O requests and responses For bulk data transfer devices (DMA, network), buffer space allocated out of band by GuestOS Descriptor contains unique identifier to allow out of order processing Multiple requests can be added before hypercall made to begin processing Event notificati ...
Abstract View of System Components
... • Stack Pointer (SP): points to the top of the current stack in memory. The stack contains one frame for each procedure that has been entered but not yet exited. • Program Status Word (PSW): contains the condition code bits and various other control bits. ...
... • Stack Pointer (SP): points to the top of the current stack in memory. The stack contains one frame for each procedure that has been entered but not yet exited. • Program Status Word (PSW): contains the condition code bits and various other control bits. ...
Chapter 2 – outline
... Uninstall programs that allow you to safely and completely remove unneeded programs and related files from your hard disk. Backup programs that make copies of files to be used in case the originals are lost or damaged. File compression programs that reduce the size of files so they require les ...
... Uninstall programs that allow you to safely and completely remove unneeded programs and related files from your hard disk. Backup programs that make copies of files to be used in case the originals are lost or damaged. File compression programs that reduce the size of files so they require les ...
Chapter 3 Process Description and Control
... both main and secondary memory. • Must include this information: – 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 ...
... both main and secondary memory. • Must include this information: – 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 ...
Module 4: Processes
... Parent may terminate execution of children processes (abort ()). Why would parent do that? Child has exceeded allocated resources. Task assigned to child is no longer required. Parent is exiting. • Operating system does not allow child to continue if its parent terminates. • Cascading termi ...
... Parent may terminate execution of children processes (abort ()). Why would parent do that? Child has exceeded allocated resources. Task assigned to child is no longer required. Parent is exiting. • Operating system does not allow child to continue if its parent terminates. • Cascading termi ...
Embedding Object Files in an Existing Operating System: A Practical Approach
... efficient procedure of embedding object file model into a Non-Object-Oriented OS. Most of the available ObjectOriented languages rely on slow interpreters and require much run-time. Since C++ supports a minimalist view of Object-Oriented programming. The strengths of C++ are that it is efficient, po ...
... efficient procedure of embedding object file model into a Non-Object-Oriented OS. Most of the available ObjectOriented languages rely on slow interpreters and require much run-time. Since C++ supports a minimalist view of Object-Oriented programming. The strengths of C++ are that it is efficient, po ...