Exam 4: Processor Management

Most computer programs alternate between CPU cycles and I/O cycles.

An I/O request is called a(n)____ wait in multiprogramming environments.

When using priority scheduling,priorities are assigned to jobs by the owner of the job (the user).

The shortest remaining time (SRT)algorithm is often used in interactive systems.

CPU-bound jobs (such as printing a series of documents)have many brief CPU cycles and long I/O cycles.

First-come,first-served (FCFS)is a preemptive scheduling algorithm that handles jobs according to their arrival time.

When using a multiple-level queue strategy,aging is used to ensure that jobs in lower-level queues will eventually complete their execution.

A single processor can be shared by several jobs,or several processes,but only if the operating system has a scheduling policy,as well as a scheduling algorithm,to determine when to stop working on one job and proceed to another.

The Process Scheduler assigns the CPU to execute the processes for those jobs placed on the ____ queue by the Job Scheduler.

____ allows for faster turnaround of CPU-bound jobs.

A processor is also known as a CPU.

____ requires that the processor be allocated to each job or to each process for a period of time and deallocated at an appropriate moment.

Assume that four jobs,A-D,are in the READY queue at Time 0 and require the CPU cycles listed below.Using the SJN algorithm,the ____ job is run first. Job: A B C D CPU cycle: 5 2 6 4

When a job is accepted by the system,it's put on ____ and placed in a queue.

A general rule of thumb for selecting a proper time quantum in Round Robin scheduling is that it should be long enough to allow ____ percent of the CPU cycles to run to completion.

The Job Scheduler seeks to ____ when scheduling jobs.

Some systems use a strategy known as ____ to increase the priority of jobs that have been in the system for an unusually long time in order to expedite their exit.

Assume that four jobs,A-D,require the CPU cycles listed below.Using the SJN algorithm,the average turnaround time is ____. Job: A B C D CPU cycle: 5 2 6 4

Assume that jobs A-D arrive in the READY queue in quick succession and have the CPU cycle requirements listed below.Using the SRT algorithm,the average turnaround time is ____. Arrival time: 0 1 2 3 Job: A B C D CPU cycle: 6 3 1 4

It is possible to minimize response time by running only interactive jobs and letting batch jobs wait until the interactive load ceases.