Overview of Operating Systems
... * Ensure good user service and efficient use - Management of Resources * Efficient allocation/de-allocation without constraining user programs - Security and Protection * Ensure absence of interference with programs and resources by entities within and outside the OS ...
... * Ensure good user service and efficient use - Management of Resources * Efficient allocation/de-allocation without constraining user programs - Security and Protection * Ensure absence of interference with programs and resources by entities within and outside the OS ...
交大資工蔡文能計概
... • Since Bell Labs, part of AT&T, was not allowed to be in the computer business, it licensed UNIX to universities. • Also, at that time, the PDP-11 series was the workhorse of most computer science departments. • Result: UNIX was a hit on campus. http://en.wikipedia.org/wiki/Unix 交大資工 蔡文能 計概 ...
... • Since Bell Labs, part of AT&T, was not allowed to be in the computer business, it licensed UNIX to universities. • Also, at that time, the PDP-11 series was the workhorse of most computer science departments. • Result: UNIX was a hit on campus. http://en.wikipedia.org/wiki/Unix 交大資工 蔡文能 計概 ...
Ch 1 Getting Started with the Operating System
... The function of, and rules for, file specifications a check to see if they have mastered will be explained. concepts. Will discuss why Microsoft has DOS functions available to the user. Will compare and contrast data files with system files. Will explain the purpose and function of commands ...
... The function of, and rules for, file specifications a check to see if they have mastered will be explained. concepts. Will discuss why Microsoft has DOS functions available to the user. Will compare and contrast data files with system files. Will explain the purpose and function of commands ...
Lecture Note VIII
... Plus, slows down hardware because need to take time to do add/compare on every memory reference. Base and bounds is simple and fast but it has the following disadvantages: 1. hard to share between programs for example, suppose two copies of "vi" :we want to share code , only data and stack need to b ...
... Plus, slows down hardware because need to take time to do add/compare on every memory reference. Base and bounds is simple and fast but it has the following disadvantages: 1. hard to share between programs for example, suppose two copies of "vi" :we want to share code , only data and stack need to b ...
Distributed Operating Systems Introduction
... Resource sharing Allowing multiple users and applications to share resources (local and remote): ...
... Resource sharing Allowing multiple users and applications to share resources (local and remote): ...
File System - dhdurso.org index to available resources
... The block and fragment sizes are set during file-system creation according to the intended use of the file system: – If many small files are expected, the fragment size should be small. – If repeated transfers of large files are expected, the basic block size should be large. The maximum block-to-fr ...
... The block and fragment sizes are set during file-system creation according to the intended use of the file system: – If many small files are expected, the fragment size should be small. – If repeated transfers of large files are expected, the basic block size should be large. The maximum block-to-fr ...
Introduction:- CS-502 Operating Systems
... security: how is the integrity of the OS and its resources ensured? protection: how is one user/program protected from another? performance: how do we make it all go fast? reliability: what happens if something goes wrong – hardware or software extensibility: can we add new features? communication: ...
... security: how is the integrity of the OS and its resources ensured? protection: how is one user/program protected from another? performance: how do we make it all go fast? reliability: what happens if something goes wrong – hardware or software extensibility: can we add new features? communication: ...
9. File Systems and I/O Management
... like in a producer-consumer situation. • Some file system functionalities require duplicating a file descriptor. When a file descriptor is duplicated, a second file descriptor is created to point to the same global file table entry. Therefore, the global file table entry has a reference count to kee ...
... like in a producer-consumer situation. • Some file system functionalities require duplicating a file descriptor. When a file descriptor is duplicated, a second file descriptor is created to point to the same global file table entry. Therefore, the global file table entry has a reference count to kee ...
Threads
... Linux refers to them as tasks rather than threads. Thread creation is done through clone() system call. Clone() allows a child task to share the address space of ...
... Linux refers to them as tasks rather than threads. Thread creation is done through clone() system call. Clone() allows a child task to share the address space of ...
COS 318: Operating Systems Virtual Machine Monitors Kai Li and Andy Bavier
... u Full-virtualized – Legacy OS can run unmodified on top of VMware Workstation u Appears like a process to the Host OS u ...
... u Full-virtualized – Legacy OS can run unmodified on top of VMware Workstation u Appears like a process to the Host OS u ...
Lecture 15
... service. Some drivers will be able to start next request at this time. – Windows: scheduler is available but also means for ...
... service. Some drivers will be able to start next request at this time. – Windows: scheduler is available but also means for ...
Operating System
... Wait loop (contention for memory access). At most one I/O request is outstanding at a time, no simultaneous I/O processing. After I/O starts, control returns to user program without waiting for I/O completion. System call – request to the operating system to allow user to wait for I/O comple ...
... Wait loop (contention for memory access). At most one I/O request is outstanding at a time, no simultaneous I/O processing. After I/O starts, control returns to user program without waiting for I/O completion. System call – request to the operating system to allow user to wait for I/O comple ...
What is an Operating System?
... Previous slide was very important (that's what allows modern OSes to work) ...
... Previous slide was very important (that's what allows modern OSes to work) ...
CS540_Ch19
... CPU burst by the start of its next period. The CPU utilization of a process Pi as the ratio of its burst to its period – ti/pi so, for P1 it is 20/50 = 0.40 and for P2 it is 35/100 = 0.35. so total CPU utilization of 75 percent. First, suppose we assign P2 a higher priority than P1. ...
... CPU burst by the start of its next period. The CPU utilization of a process Pi as the ratio of its burst to its period – ti/pi so, for P1 it is 20/50 = 0.40 and for P2 it is 35/100 = 0.35. so total CPU utilization of 75 percent. First, suppose we assign P2 a higher priority than P1. ...
Operating-System Structures
... Microkernel System Structure Moves as much from the kernel into “user” space Communication takes place between user modules using ...
... Microkernel System Structure Moves as much from the kernel into “user” space Communication takes place between user modules using ...
Chapter 19 Real
... CPU burst by the start of its next period. The CPU utilization of a process Pi as the ratio of its burst to its period – ti/pi so, for P1 it is 20/50 = 0.40 and for P2 it is 35/100 = 0.35. so total CPU utilization of 75 percent. First, suppose we assign P2 a higher priority than P1. ...
... CPU burst by the start of its next period. The CPU utilization of a process Pi as the ratio of its burst to its period – ti/pi so, for P1 it is 20/50 = 0.40 and for P2 it is 35/100 = 0.35. so total CPU utilization of 75 percent. First, suppose we assign P2 a higher priority than P1. ...
OSPP: The Kernel Abstraction
... • Request kernel to perform a privileged action • Library routine acts as wrapper function (stub) around a trap into the kernel – Sets registers to pass the appropriate system call identification code and any parameters (e.g., size, address) – Trap is intentional interrupt ...
... • Request kernel to perform a privileged action • Library routine acts as wrapper function (stub) around a trap into the kernel – Sets registers to pass the appropriate system call identification code and any parameters (e.g., size, address) – Trap is intentional interrupt ...
Identifying Security Risks
... to use sequential processing, where each process request is completed and the data returned before the next process is started • Real-time systems are what most of us are familiar with today • PC-based operating systems, such as Windows 98 or Windows XP, interact directly with the user—even multiple ...
... to use sequential processing, where each process request is completed and the data returned before the next process is started • Real-time systems are what most of us are familiar with today • PC-based operating systems, such as Windows 98 or Windows XP, interact directly with the user—even multiple ...
Discovering Computers
... system provides a user interface, manages programs, manages memory, and coordinates tasks ...
... system provides a user interface, manages programs, manages memory, and coordinates tasks ...
A1_OS Review_SP09
... a certain amount of time the CPU is switched to another job. The difference is that the switching between jobs occurs so frequently that the users can interact with each program while it is running. This concept is also known as time-sharing. Sometimes the two terms are used interchangeably. Multipr ...
... a certain amount of time the CPU is switched to another job. The difference is that the switching between jobs occurs so frequently that the users can interact with each program while it is running. This concept is also known as time-sharing. Sometimes the two terms are used interchangeably. Multipr ...
... Storage Definitions and Notation Review The basic unit of computer storage is the bit. A bit can contain one of two values, 0 and 1. All other storage in a computer is based on collections of bits. Given enough bits, it is amazing how many things a computer can represent: numbers, letters, images, ...
2. Operating Systems
... u Languages defined to replace assembly language for systems programming allow system calls to be made directly (e.g., C, C++) Three general methods are used to pass parameters between a running program and the operating system. u Pass parameters in registers. u Store the parameters in a table in me ...
... u Languages defined to replace assembly language for systems programming allow system calls to be made directly (e.g., C, C++) Three general methods are used to pass parameters between a running program and the operating system. u Pass parameters in registers. u Store the parameters in a table in me ...