UNIX Operating System
... Journaling file system A journaling file system keeps track of the changes that will be made in a journal (usually a circular log in a dedicated area of the file system) before committing them to the main file system. In the event of a system crash or power failure, such file systems are quicker to ...
... Journaling file system A journaling file system keeps track of the changes that will be made in a journal (usually a circular log in a dedicated area of the file system) before committing them to the main file system. In the event of a system crash or power failure, such file systems are quicker to ...
Processes
... – the program counter (PC), indicating the next instruction – general-purpose processor registers and their values – a set of OS resources • open files, network connections, sound channels, … ...
... – the program counter (PC), indicating the next instruction – general-purpose processor registers and their values – a set of OS resources • open files, network connections, sound channels, … ...
Processes and Threads
... information across processes is not easy. Threads are a type of light-weight processes that are widely used in such situations. • Every process has a single thread (of execution) by default, but can create several new threads once it starts. Threads of a process share memory corresponding to the cod ...
... information across processes is not easy. Threads are a type of light-weight processes that are widely used in such situations. • Every process has a single thread (of execution) by default, but can create several new threads once it starts. Threads of a process share memory corresponding to the cod ...
lecture5-sept15
... • OS creates a new PCB when fork() is called with a unique id for the new process • The calling process is the parent, the new process is the child • Then adds the child’s PCB to the ready queue • The child process is ready to go! • What code is the child going to execute? ...
... • OS creates a new PCB when fork() is called with a unique id for the new process • The calling process is the parent, the new process is the child • Then adds the child’s PCB to the ready queue • The child process is ready to go! • What code is the child going to execute? ...
Process Concept
... • Behind the scenes, functions that make up an API typically invoke system calls. Why would an application programmer prefer programming according to an API rather than invoking actual system calls? ...
... • Behind the scenes, functions that make up an API typically invoke system calls. Why would an application programmer prefer programming according to an API rather than invoking actual system calls? ...
Introduction
... Real time. Often used in a dedicated application, this system reads information from sensors and must respond within a fixed amount of time to ensure correct performance. ...
... Real time. Often used in a dedicated application, this system reads information from sensors and must respond within a fixed amount of time to ensure correct performance. ...
An Overview of Fault Tolerance Techniques for Real
... (three places/memories to imitate TMR). Whenever a task’s data/states are changed, these changes are applied to all replicas. Whenever the task wants to read data from memory, a voting is done on replicas to determine if data are changed inadvertently or are corrupted (for any reason, such as heavy ...
... (three places/memories to imitate TMR). Whenever a task’s data/states are changed, these changes are applied to all replicas. Whenever the task wants to read data from memory, a voting is done on replicas to determine if data are changed inadvertently or are corrupted (for any reason, such as heavy ...
COS 318: Operating Systems Processes and Threads Kai Li Computer Science Department
... • CISC machines have a special instruction to save and restore all registers on stack • RISC: reserve registers for kernel or have way to carefully save one and then continue ...
... • CISC machines have a special instruction to save and restore all registers on stack • RISC: reserve registers for kernel or have way to carefully save one and then continue ...
On-Line & Real-Time Modes of Use Presentation
... enough to affect the next input. •Is by definition also on-line. •Used when a system must react immediately when input from a sensor or other input device is received as a delay is ...
... enough to affect the next input. •Is by definition also on-line. •Used when a system must react immediately when input from a sensor or other input device is received as a delay is ...
Slide Set 7
... Fully Buffered: I/O takes place when a buffer is full. Disk files are normally fully buffered. The buffer is allocated by the I/O library itself by doing a malloc. Line Buffered: I/O takes place when a new line character is encountered. Line buffering is used for terminal I/O. Note that I/O may take ...
... Fully Buffered: I/O takes place when a buffer is full. Disk files are normally fully buffered. The buffer is allocated by the I/O library itself by doing a malloc. Line Buffered: I/O takes place when a new line character is encountered. Line buffering is used for terminal I/O. Note that I/O may take ...
Operating system organization - cs.rochester.edu
... After I/O starts, control returns to user program without waiting for I/O completion. Device controller later informs CPU that it has finished its operation by causing an interrupt. When an interrupt occur, current execution is put on hold; the CPU jumps to a service routine called “interrupt handle ...
... After I/O starts, control returns to user program without waiting for I/O completion. Device controller later informs CPU that it has finished its operation by causing an interrupt. When an interrupt occur, current execution is put on hold; the CPU jumps to a service routine called “interrupt handle ...
No Slide Title
... Coding is time-consuming Leads to missed opportunities for parallel processing Leads to errors where parallel processing is mistakenly indicated Programs are difficult to modify ...
... Coding is time-consuming Leads to missed opportunities for parallel processing Leads to errors where parallel processing is mistakenly indicated Programs are difficult to modify ...
AOSScheduling
... Determines which programs are admitted to the system for processing Controls the degree of multiprogramming Attempts to keep a balanced mix of processor-bound and I/O-bound processes CPU usage System performance ...
... Determines which programs are admitted to the system for processing Controls the degree of multiprogramming Attempts to keep a balanced mix of processor-bound and I/O-bound processes CPU usage System performance ...
Threads, SMP, and Microkernels
... ◦ Message are sent without knowing what the target machine is ...
... ◦ Message are sent without knowing what the target machine is ...
Threads, SMP, and Microkernels
... ▫ Message are sent without knowing what the target machine is ...
... ▫ Message are sent without knowing what the target machine is ...
Mach Memory
... Each resident page corresponds to a page of physical memory. Records the memory object, its offset and permissions. A hashed table is kept for a fast lookup. ...
... Each resident page corresponds to a page of physical memory. Records the memory object, its offset and permissions. A hashed table is kept for a fast lookup. ...
Self-Assessment Interactive Topic 1
... _ Program execution. The operating system loads the contents (or sections) of a file into memory and begins its execution. A user-level program could not be trusted to properly allocate CPU time. _ I/O operations. Disks, tapes, serial lines, and other devices must be communicated with at a very low ...
... _ Program execution. The operating system loads the contents (or sections) of a file into memory and begins its execution. A user-level program could not be trusted to properly allocate CPU time. _ I/O operations. Disks, tapes, serial lines, and other devices must be communicated with at a very low ...
Operating Systems
... system-wide open-file table, etc.) Directory implementation Free space management methods Space Allocation Methods Time and space performance of allocation methods Brief introduction to Network File System (NFS) © Copyright Virtual University of ...
... system-wide open-file table, etc.) Directory implementation Free space management methods Space Allocation Methods Time and space performance of allocation methods Brief introduction to Network File System (NFS) © Copyright Virtual University of ...
Threads, SMP, and Microkernels
... – Message are sent without knowing what the target machine is ...
... – Message are sent without knowing what the target machine is ...
Linux+ Guide to Linux Certification
... – Any processes that have used a lot of CPU time will get lower priority than those that have not ...
... – Any processes that have used a lot of CPU time will get lower priority than those that have not ...