Module 6: CPU Scheduling - Simon Fraser University
... CPU bursts lengths: many short bursts, and few long ones ...
... CPU bursts lengths: many short bursts, and few long ones ...
Objectives of KeyKOS
... sophisticated resource scheduling policies as kernel does too many things, it tends to be large and unreliable additionally, monolithic OS cannot evolve over time to meet new requirements ...
... sophisticated resource scheduling policies as kernel does too many things, it tends to be large and unreliable additionally, monolithic OS cannot evolve over time to meet new requirements ...
PPT - Surendar Chandra
... Designing an Operating Systems Goal is to understand how the technologies that we studied so far apply to typical machines First we focus on PDAs and Laptops Both are mobile, inexpensive Battery is a big concern ...
... Designing an Operating Systems Goal is to understand how the technologies that we studied so far apply to typical machines First we focus on PDAs and Laptops Both are mobile, inexpensive Battery is a big concern ...
Introduction CS 111 On-Line MS Program Operating Systems Peter
... • Process can ask for any resource • But it shouldn’t always get it • Process must not be able to create its own OSlevel capability to access a resource – OS must control which ones the process gets – OS data structures not accessible from user-mode – Only altered by trusted OS code • So if it’s the ...
... • Process can ask for any resource • But it shouldn’t always get it • Process must not be able to create its own OSlevel capability to access a resource – OS must control which ones the process gets – OS data structures not accessible from user-mode – Only altered by trusted OS code • So if it’s the ...
overhead - the denning institute
... all counted as overhead. As in organizations, excessive overhead diminishes capacity and increases cost without increasing productivity. Overhead in computer systems manifests as slower processing, less memory, less network bandwidth, or bigger latencies than expected. Overhead is not always easy to ...
... all counted as overhead. As in organizations, excessive overhead diminishes capacity and increases cost without increasing productivity. Overhead in computer systems manifests as slower processing, less memory, less network bandwidth, or bigger latencies than expected. Overhead is not always easy to ...
Rozproszone systemy operacyjne Jerzy Brzeziński
... − the workload can be spread over the available computers in the most cost effective way. ...
... − the workload can be spread over the available computers in the most cost effective way. ...
ppt
... The resources they use are protected from other processes This can be useful when processes are competing for resources (different owners who want optimal turnaround) However, sometimes we want programs to be able to interact and cooperate and even share memory space when they run, (controlled ...
... The resources they use are protected from other processes This can be useful when processes are competing for resources (different owners who want optimal turnaround) However, sometimes we want programs to be able to interact and cooperate and even share memory space when they run, (controlled ...
Slides - Bilkent University Computer Engineering Department
... – Translate name to device representation (done by open()) • Find out the inode for the file – Physically read data from disk into kernel buffer (done by read () ) • Using inode and index table we can reach the related blocks of the file – Make data available to requesting process (done by read() ) ...
... – Translate name to device representation (done by open()) • Find out the inode for the file – Physically read data from disk into kernel buffer (done by read () ) • Using inode and index table we can reach the related blocks of the file – Make data available to requesting process (done by read() ) ...
choices
... systems) – The distributed file system extension of Choices is close to the mechanism used in MMLite (proxy) – MMLite focuses on support for transparently replacing components in use ...
... systems) – The distributed file system extension of Choices is close to the mechanism used in MMLite (proxy) – MMLite focuses on support for transparently replacing components in use ...
OperatingSystemDesign_SP16_Ch_1_4
... Processor access memory to fetch instruction, and one or more times to fetch operands and/or store restults. Rate processor can execute instruction limited by memory cycle time. Process speed has been increasing more rapidly than memory access speed. Main memory should be built with same techn ...
... Processor access memory to fetch instruction, and one or more times to fetch operands and/or store restults. Rate processor can execute instruction limited by memory cycle time. Process speed has been increasing more rapidly than memory access speed. Main memory should be built with same techn ...
Module 4: Processes
... state of the old process and load the saved state for the new process Context-switch time is overhead; the system does no useful work ...
... state of the old process and load the saved state for the new process Context-switch time is overhead; the system does no useful work ...
資工系網媒所NEWS實驗室
... Single user cannot keep CPU and I/O devices busy at all times Multiprogramming organizes jobs (code and data) so CPU always has one to execute A subset of total jobs in system is kept in memory One job selected and run via job scheduling When it has to wait (for I/O for example), OS switches to anot ...
... Single user cannot keep CPU and I/O devices busy at all times Multiprogramming organizes jobs (code and data) so CPU always has one to execute A subset of total jobs in system is kept in memory One job selected and run via job scheduling When it has to wait (for I/O for example), OS switches to anot ...
Paging
... Segments are visible to the programmer Usually different segments allocated to program and data There may be a number of program and data segments associated to a single ...
... Segments are visible to the programmer Usually different segments allocated to program and data There may be a number of program and data segments associated to a single ...
Synchronization
... What needs Protection? • What needs protection? – Global kernel data structures. – Shared data between process/interrupt context. – Shared data between interrupt handlers. ...
... What needs Protection? • What needs protection? – Global kernel data structures. – Shared data between process/interrupt context. – Shared data between interrupt handlers. ...
3 Threads SMP Microkernel
... • Microkernel is a small operating system core containing only essential operating systems functions • All other OS services are implemented as server processes, execute in user mode, and communicate through messages (device drivers, file systems, virtual memory manager, windowing system, and securi ...
... • Microkernel is a small operating system core containing only essential operating systems functions • All other OS services are implemented as server processes, execute in user mode, and communicate through messages (device drivers, file systems, virtual memory manager, windowing system, and securi ...
Operating System
... The OS can then look up this protocol and discover that the rest of the data are arranged according to a pattern of
... The OS can then look up this protocol and discover that the rest of the data are arranged according to a pattern of
Unix Basics - Computer Science
... Shell can control the file descriptors of its children (redirection) This is a very powerful feature of UNIX, as it means the shell can make a process read/write different things without modifying the program, e.g. files, devices, another process. ...
... Shell can control the file descriptors of its children (redirection) This is a very powerful feature of UNIX, as it means the shell can make a process read/write different things without modifying the program, e.g. files, devices, another process. ...
Operating Systems
... ⇒ require a special (unprivileged) instruction to allow transition from user to kernel mode. • Generally called a software interrupt since operates similarly to a real (hardware) interrupt. . . • Set of OS services accessible via software interrupt mechanism called system calls. Operating Systems — ...
... ⇒ require a special (unprivileged) instruction to allow transition from user to kernel mode. • Generally called a software interrupt since operates similarly to a real (hardware) interrupt. . . • Set of OS services accessible via software interrupt mechanism called system calls. Operating Systems — ...
Main Memory
... users address space • Not limited to small number of segments • Think of this as providing a large number (thousands) of fixedsized segments (called “pages”) ...
... users address space • Not limited to small number of segments • Think of this as providing a large number (thousands) of fixedsized segments (called “pages”) ...
Nodes of a distributed system
... different machines, or one mechanism for local communication and something else for global communication. ■ Process management must be same everywhere. Must not depend on machine type. ■ File system must appear the same everywhere. Every file should be visible at every location subject to protection ...
... different machines, or one mechanism for local communication and something else for global communication. ■ Process management must be same everywhere. Must not depend on machine type. ■ File system must appear the same everywhere. Every file should be visible at every location subject to protection ...