File System
... Runs most of its services in the kernel workspace Error prone due to the amount of tasks in the kernel itself Used in most Linux systems Runs most services - like networking, filesystem, etc. - in user space More stable, but more complex designs ...
... Runs most of its services in the kernel workspace Error prone due to the amount of tasks in the kernel itself Used in most Linux systems Runs most services - like networking, filesystem, etc. - in user space More stable, but more complex designs ...
Introduction - University of Pennsylvania
... CPU is multiplexed (shared) among a number of jobs -- while one job waiting for I/O, another can use CPU. Advantages: Interactiveness is restored. CPU is kept busy. Disadvantages: Hardware and O.S. required become significantly more complex. Timesharing - switch CPU among jobs for pre- ...
... CPU is multiplexed (shared) among a number of jobs -- while one job waiting for I/O, another can use CPU. Advantages: Interactiveness is restored. CPU is kept busy. Disadvantages: Hardware and O.S. required become significantly more complex. Timesharing - switch CPU among jobs for pre- ...
Processes
... The kernel saves the context of the old process in its PCB and loads the saved context of the new process scheduled to run. Context switch time is pure overhead, because the system does no useful work ...
... The kernel saves the context of the old process in its PCB and loads the saved context of the new process scheduled to run. Context switch time is pure overhead, because the system does no useful work ...
Processes - Kent State University
... the execution of a certain task from OS standpoint is a process • OS maintains (creates/destroys) processes for user • OS schedules processes for user there are three types of schedulers: short/medium/long term OS saves process states in a process control block OS context switches between processe ...
... the execution of a certain task from OS standpoint is a process • OS maintains (creates/destroys) processes for user • OS schedules processes for user there are three types of schedulers: short/medium/long term OS saves process states in a process control block OS context switches between processe ...
Suppose that a disk drive has 10,000 cylinders, numbered 0 to 9999
... its performance. The proportional allocation algorithm allocates available memory to each process according to its size. If the page-fault rate is too high, the process may have too many frames. Paging avoids the problem of external fragmentation of memory in a multiprogramming environment. A TLB is ...
... its performance. The proportional allocation algorithm allocates available memory to each process according to its size. If the page-fault rate is too high, the process may have too many frames. Paging avoids the problem of external fragmentation of memory in a multiprogramming environment. A TLB is ...
Mutual Exclusion and Synchronization
... Enforce Single Access • If we enforce a rule that only one process may enter the function at a time then: • P1 & P2 run on separate processors • P1 enters echo first, – P2 tries to enter but is blocked – P2 suspends ...
... Enforce Single Access • If we enforce a rule that only one process may enter the function at a time then: • P1 & P2 run on separate processors • P1 enters echo first, – P2 tries to enter but is blocked – P2 suspends ...
message
... execve system call is used after a fork to replace the processes memory space with a new program. ...
... execve system call is used after a fork to replace the processes memory space with a new program. ...
CS 377: Operating Systems Outline
... • Linux Kernel - all code that is needed as soon as the system begins: CPU scheduler, memory managers, system call / interrupt support, etc • A monolithic kernel - benefits? • Kernel modules - extensions to the kernel that can be dynamically loaded or unloaded as needed: device drivers, file systems ...
... • Linux Kernel - all code that is needed as soon as the system begins: CPU scheduler, memory managers, system call / interrupt support, etc • A monolithic kernel - benefits? • Kernel modules - extensions to the kernel that can be dynamically loaded or unloaded as needed: device drivers, file systems ...
08 Operating System Support
... execute a program. Instruction and data must be loaded into main memory, I/O devices and file must be initialized, and other resources must be prepared. OS handle all of this for the user • Access to I/O devices: Each I/O device requires its own specific set of instructions or control signals for op ...
... execute a program. Instruction and data must be loaded into main memory, I/O devices and file must be initialized, and other resources must be prepared. OS handle all of this for the user • Access to I/O devices: Each I/O device requires its own specific set of instructions or control signals for op ...
Operating Systems – Processes
... • 16 users may all be running an application (e.g., emacs), while there is only one image of “emacs” loaded in the system • This image (i.e., binary) is shared among the different processes running on behalf of the 16 users • I.e., code (and data) can be shared among processes • Shared libraries, sh ...
... • 16 users may all be running an application (e.g., emacs), while there is only one image of “emacs” loaded in the system • This image (i.e., binary) is shared among the different processes running on behalf of the 16 users • I.e., code (and data) can be shared among processes • Shared libraries, sh ...
Modern Operating Systems Modern Operating Systems
... – Process is divided into threads that can run concurrently • Thread – Dispatchable unit of work – executes sequentially and is interruptable ...
... – Process is divided into threads that can run concurrently • Thread – Dispatchable unit of work – executes sequentially and is interruptable ...
COS 318: Operating Systems Processes and Threads Kai Li Computer Science Department
... • RISC: reserve registers for kernel or have way to carefully save one and then continue ...
... • RISC: reserve registers for kernel or have way to carefully save one and then continue ...
COS 318: Operating Systems Processes and Threads
... Program is just the code; just part of process state Example: many users can run the same program ...
... Program is just the code; just part of process state Example: many users can run the same program ...
An operating system - Bilkent University Computer Engineering
... switches jobs so frequently that users can interact with each job while it is running, creating interactive computing – Response time should be < 1 second – Each user has at least one program executing in memory process – If several jobs ready to run at the same time CPU scheduling – If processes ...
... switches jobs so frequently that users can interact with each job while it is running, creating interactive computing – Response time should be < 1 second – Each user has at least one program executing in memory process – If several jobs ready to run at the same time CPU scheduling – If processes ...
ppt
... Can improve performance by overlapping activities or performing work in parallel Can enable simpler program design Simplifies distribution ...
... Can improve performance by overlapping activities or performing work in parallel Can enable simpler program design Simplifies distribution ...
Document
... A) block other processes, B) do I/O, C) change from ready to running, D) terminate, E) none of these 3. _____ No assumptions are made about speeds or A) the size of memory, B) the number of CPUs, C) the number of printers, D) the number of secondary memory devices, E) none of these 4. _____ No two p ...
... A) block other processes, B) do I/O, C) change from ready to running, D) terminate, E) none of these 3. _____ No assumptions are made about speeds or A) the size of memory, B) the number of CPUs, C) the number of printers, D) the number of secondary memory devices, E) none of these 4. _____ No two p ...
Operating Systems I: Chapter 4
... In a multiple threaded task, while one server thread is blocked and waiting, a second thread in the same task can run. – Threads provide a mechanism that allow sequential processes to make blocking system calls while also achieving parallelism. – Cooperation of multiple threads in same job confers h ...
... In a multiple threaded task, while one server thread is blocked and waiting, a second thread in the same task can run. – Threads provide a mechanism that allow sequential processes to make blocking system calls while also achieving parallelism. – Cooperation of multiple threads in same job confers h ...
in memory
... Memory is divided into equally sized sections called frames. The program is divided into equally sized sections called pages. The program does not have to be contiguous in memory. The whole program still needs to be in memory before being executed. Fragmentation internal fragmentation – the last f ...
... Memory is divided into equally sized sections called frames. The program is divided into equally sized sections called pages. The program does not have to be contiguous in memory. The whole program still needs to be in memory before being executed. Fragmentation internal fragmentation – the last f ...
OS-process-lee
... As a process executes, it changes state new: The process is being created ready: The process is waiting to be assigned to a processor running: Instructions are being executed waiting: The process is waiting for some event (e.g. I/O) to occur terminated: The process has finished execution ...
... As a process executes, it changes state new: The process is being created ready: The process is waiting to be assigned to a processor running: Instructions are being executed waiting: The process is waiting for some event (e.g. I/O) to occur terminated: The process has finished execution ...
05_Concurrency-Mutex&Synchronization
... Enforce Single Access • If we enforce a rule that only one process may enter the function at a time then: • P1 & P2 run on separate processors • P1 enters echo first, – P2 tries to enter but is blocked – P2 suspends ...
... Enforce Single Access • If we enforce a rule that only one process may enter the function at a time then: • P1 & P2 run on separate processors • P1 enters echo first, – P2 tries to enter but is blocked – P2 suspends ...
A Reflective Middleware Framework for Communication in
... execve system call is used after a fork to replace the processes memory space with a new program. ...
... execve system call is used after a fork to replace the processes memory space with a new program. ...
System Software
... the current status, i.e., the contents of the CPU registers, of the suspended process (in a structure called a process control block) in the memory so that the suspended process can resume execution seamlessly when it is allocated with more CPU time at a later stage. The storing of the status of a ...
... the current status, i.e., the contents of the CPU registers, of the suspended process (in a structure called a process control block) in the memory so that the suspended process can resume execution seamlessly when it is allocated with more CPU time at a later stage. The storing of the status of a ...
Module 4: Processes
... Example 1: a file or web server on a LAN. The server needs to handle several file or web requests over a short period. Hence more efficient to create (and destroy) a single thread for each request. ...
... Example 1: a file or web server on a LAN. The server needs to handle several file or web requests over a short period. Hence more efficient to create (and destroy) a single thread for each request. ...