ppt
... using the wait()system call. The call returns status information and the pid of the terminated process pid = wait(&status); If no parent waiting (did not invoke wait()) process is a zombie If parent terminated without invoking wait , process is an orphan ...
... using the wait()system call. The call returns status information and the pid of the terminated process pid = wait(&status); If no parent waiting (did not invoke wait()) process is a zombie If parent terminated without invoking wait , process is an orphan ...
Abstract View of System Components
... ensure that an incorrect program cannot cause other programs to execute incorrectly. Provide hardware support to differentiate between at least two ...
... ensure that an incorrect program cannot cause other programs to execute incorrectly. Provide hardware support to differentiate between at least two ...
What is an Operating System?
... Group identifier (group ID) allows set of users to be defined and controls managed, then also associated with each process, ...
... Group identifier (group ID) allows set of users to be defined and controls managed, then also associated with each process, ...
MachOs-by-Doug-Hill-Liza-Hill-Josh-Mickley-Alex
... • A task is the basic unit of resource allocation. It includes a virtual address space, access to resources, and may include one or more threads. • A thread is a sequence of instruction executions. All threads within a task share the resources of that task. ...
... • A task is the basic unit of resource allocation. It includes a virtual address space, access to resources, and may include one or more threads. • A thread is a sequence of instruction executions. All threads within a task share the resources of that task. ...
Operating Systems
... processes lottery tickets for various system resources, such as CPU time. Whenever a scheduling decision has to be made, a lottery ticket is chosen at random, and the process holding that ticket gets the ...
... processes lottery tickets for various system resources, such as CPU time. Whenever a scheduling decision has to be made, a lottery ticket is chosen at random, and the process holding that ticket gets the ...
Processes
... using the wait()system call. The call returns status information and the pid of the terminated process pid = wait(&status); If no parent waiting (did not invoke wait()) process is a zombie If parent terminated without invoking wait , process is an orphan ...
... using the wait()system call. The call returns status information and the pid of the terminated process pid = wait(&status); If no parent waiting (did not invoke wait()) process is a zombie If parent terminated without invoking wait , process is an orphan ...
2007-06.pdf
... 3b Disabling interrupts used to be a standard technique for protecting critical sections in operating systems. Will this technique also work for an operating system designed for a multicore processor? ...
... 3b Disabling interrupts used to be a standard technique for protecting critical sections in operating systems. Will this technique also work for an operating system designed for a multicore processor? ...
Main Memory
... • Flexible: Can fit physical chunks of memory into arbitrary places in users address space • Not limited to small number of segments • Think of this as providing a large number (thousands) of fixedsized segments (called “pages”) ...
... • Flexible: Can fit physical chunks of memory into arbitrary places in users address space • Not limited to small number of segments • Think of this as providing a large number (thousands) of fixedsized segments (called “pages”) ...
week 24 - Memory, storage, processors and operating systems
... the processor, a copy of the data is saved to cache. When the processor needs more data, the addresses are checked to see if the data is already in the cache, if it there is no need to transfer the data from main memory which is slower. This is a cache hit and the data is taken directly from the c ...
... the processor, a copy of the data is saved to cache. When the processor needs more data, the addresses are checked to see if the data is already in the cache, if it there is no need to transfer the data from main memory which is slower. This is a cache hit and the data is taken directly from the c ...
File - You have to dream before your dreams can come
... In addition to the main memory, a lot of computers have a small amount of nonvolatile random access memory. Unlike RAM, nonvolatile memory does not lose its contents when the power is switched off. ROM (Read Only Memory) is programmed at the factory and cannot be altered afterward. It is fast and ...
... In addition to the main memory, a lot of computers have a small amount of nonvolatile random access memory. Unlike RAM, nonvolatile memory does not lose its contents when the power is switched off. ROM (Read Only Memory) is programmed at the factory and cannot be altered afterward. It is fast and ...
Abstract View of System Components
... single thread (of control). • Modern operating systems allow a process to contain multiple threads of control. • Each thread, is defined by its thread ID, program counter, register set & stack (for temporary data). • A thread shares with other threads of the same process its code section, data secti ...
... single thread (of control). • Modern operating systems allow a process to contain multiple threads of control. • Each thread, is defined by its thread ID, program counter, register set & stack (for temporary data). • A thread shares with other threads of the same process its code section, data secti ...
CIT 500: IT Fundamentals
... For each file that is a directory, ls lists the contents of the directory. For each file that is an ordinary file, ls repeats its name and any other information requested. The output is sorted alphabetically by default. When no argument is given, the current directory is listed. … ...
... For each file that is a directory, ls lists the contents of the directory. For each file that is an ordinary file, ls repeats its name and any other information requested. The output is sorted alphabetically by default. When no argument is given, the current directory is listed. … ...
Course: Operating Systems Instructor: M Umair
... resources. For example, a printer cannot be simultaneously shared by several processes. Sharable resources, in contrast, do not require mutually exclusive access and thus cannot be involved in a deadlock. Read-only files are a good example of a sharable resource. ...
... resources. For example, a printer cannot be simultaneously shared by several processes. Sharable resources, in contrast, do not require mutually exclusive access and thus cannot be involved in a deadlock. Read-only files are a good example of a sharable resource. ...
What is an Operating System? ¯ Three views of an operating system
... System View: what problems doesresources it solve? among running programs. It processes, abstract view ofamong program execution controlsthreads: the sharing of resources programs. Implementation View: how is it built? sockets, pipes: view of network or it other channels ¯ The OS itselfabstract also ...
... System View: what problems doesresources it solve? among running programs. It processes, abstract view ofamong program execution controlsthreads: the sharing of resources programs. Implementation View: how is it built? sockets, pipes: view of network or it other channels ¯ The OS itselfabstract also ...
Threads
... • When a traditional, single-threaded program requests a service from the operating system, it must wait for that service to complete, often leaving the CPU idle • Multithreading provides progress even though one or more threads wait for an event as long as other threads are active Ceng 334 - Operat ...
... • When a traditional, single-threaded program requests a service from the operating system, it must wait for that service to complete, often leaving the CPU idle • Multithreading provides progress even though one or more threads wait for an event as long as other threads are active Ceng 334 - Operat ...
OPERATING SYSTEM CONCEPTS
... Some early computers protected the operating system by placing it in a memory partition that could not be modified by either the user job or the operating system itself. Describe two difficulties that you think could arise with such a scheme. Answer: The data required by the operating system (passwo ...
... Some early computers protected the operating system by placing it in a memory partition that could not be modified by either the user job or the operating system itself. Describe two difficulties that you think could arise with such a scheme. Answer: The data required by the operating system (passwo ...
Proceedings of HotOS IX: The 9th Workshop on USENIX Association
... We use the relationship between overhead and productivity to determine if there is a need to tune the system. Figure 1 shows three schematic plots that represent different relationships between overhead and productivity. In the first plot, both overhead and productivity are increasing, indicating that ...
... We use the relationship between overhead and productivity to determine if there is a need to tune the system. Figure 1 shows three schematic plots that represent different relationships between overhead and productivity. In the first plot, both overhead and productivity are increasing, indicating that ...
... This includes long-term storage, the central processing unit (CPU), short-term memory and the input and output devices. When an application needs one of these resources, the kernel makes the resource available and completes the request. This handling of resources allows the operating systems to be b ...
ch18
... 1. Normal kernel code is nonpreemptible (until 2.6) – 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 2.6) – 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 ...
Multicore OSes: Looking Forward from 1991, er, 2011 Harvard University Abstract
... works given shared physical memory, would still have to provide virtual memory and similar low-level services underneath the application, but the size of the “kernel” layer underneath the application would be minimal. In either case it does not matter if the kernel components that receive system cal ...
... works given shared physical memory, would still have to provide virtual memory and similar low-level services underneath the application, but the size of the “kernel” layer underneath the application would be minimal. In either case it does not matter if the kernel components that receive system cal ...
ppt - UNSW
... °Can avoid interrupts during the interrupt routine? • What if more important interrupt occurs while servicing this interrupt? • Allow interrupt routine to be entered again? ...
... °Can avoid interrupts during the interrupt routine? • What if more important interrupt occurs while servicing this interrupt? • Allow interrupt routine to be entered again? ...