Term
| What components make up a process in ram |
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Definition
Text section - program code Data Section - Global variables Stack - Local variables, parameters, return addresses Heap - Dynamically allocated memory during runtime |
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Term
| What is and what information is stored in a PCB |
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Definition
*process state *program counter *cpu registers (context switching) *cpu scheduling information *Memory-management information *Accounting information *I/O status *PID *Priority |
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Term
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Definition
| A system call provides an interface to services available from the operating system. |
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Term
| Describe the 3 different types of kernels |
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Definition
*Monolithic - The entire O/S runs in kernel mode *Microkernel - Only the kernel itself runs in kernel mode. Message passing is used for interaction with the kernel *Hybrid - mix of Monolithic and Microkernel |
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Term
| What is the difference between a mechanism and a policy |
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Definition
| A mechanism is how to do something and a policy is what should be done. |
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Term
| What is a virtual machine |
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Definition
| the abstraction of a computer system into several seperate invironments creating the illusion that each running instance is it's own system. |
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Term
| How are new processes created using the fork() call? |
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Definition
*A copy is made of the address space of the original process. *Both processes continue execution after the fork call. *fork will return the PID of the child to the parent process, and 0 to the parent. |
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Term
| What are the advantages of threads? |
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Definition
*Simple communication between threads * Share global variables *Fast context switching *Less memory needed |
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Term
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Definition
| a way to notify a process that a particular event has occured |
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Term
| Scheduling: CPU utilization |
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Definition
| percentage of time that the cpu is being used |
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Term
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Definition
| The number of processes executed per unit of time. |
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Term
| Scheduling: Turnaround time |
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Definition
| The interval from when aprocess is submitted to a queue to it's completion. |
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Term
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Definition
| The time a process spends in a queue. |
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Term
| Scheduling: Response time |
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Definition
| The time from when a process is first submitted to it's first result. |
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Term
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Definition
| Increasing the priority of a process as it waits a long time in a queue. |
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