Explain a computing environment, Operating System

Assignment Help:

Q. Polling for an I/O completion is able to waste a large number of CPU cycles if the processor iterates a busy-waiting loop several times before the I/O completes. However if the I/O device is ready for service polling can be much more proficient than is catching and dispatching an interrupt. Explain a hybrid strategy that combines sleeping, polling, and interrupts for I/O device service. For every of these three strategies (pure polling, pure interrupts, hybrid) explain a computing environment in which that strategy is more efficient than is either of the others.

Answer: A hybrid approach could switch among polling and interrupts depending on the length of the I/O operation wait. For instance we could poll and loop N times and if the device is still busy at N+1 we could set an interrupt and sleep. This approach would evade long busy-waiting cycles. This process would be best for very long or very short busy times. It would be incompetent it the I/O completes at N+T (where T is a small number of cycles) because of the overhead of polling plus setting up and catching interrupts.

Pure polling is best with extremely short wait times. Interrupts are best with known long wait times.


Related Discussions:- Explain a computing environment

Windows Resources on a Network, VoIP (Voice over Internet Protocol), also c...

VoIP (Voice over Internet Protocol), also called Internet telephone, was once a novelty on the Internet, but not very useful because of all the problems with poor voice quality and

Definition of operating system, Q. Definition of Operating System? Defi...

Q. Definition of Operating System? Definition of Operating System: • An Operating system is a program which controls execution of application programs and acts as an interfa

What are a safe state and an unsafe state, What are a safe state and an uns...

What are a safe state and an unsafe state? Answer:  A state is safe if the system can allocate resources to every process in some order and still avoid a deadlock. A system is

Explain the demand paging system, Question : (a) In the demand paging ...

Question : (a) In the demand paging system, when a process tries to access a page that was not brought into memory, a page fault occurs that involves a series of actions. The

Cpu scheduling alogarithm program in javascript, a program that can do cpu ...

a program that can do cpu scheduling algorithm priority using javascript or php to display gaant chart and calculate waiting and average waiting time

What are kernels and what do kernels do, What are kernels and what do kerne...

What are kernels and what do kernels do? The kernel is a program that comprises the central core of a computer operating   system. It has entire control over everything that

priority-based scheduling algorithm , Your task is to replace the round ro...

Your task is to replace the round robin CPU scheduling scheme you developed in Practical 6 with a priority-based scheduling algorithm. To simplify matters, you can maintain the ori

Activities of operating system - memory management, Q. What are the three m...

Q. What are the three main activities of an operating system in regard to memory management? Answer: a. Keep follows of which parts of memory are currently being used and

Evaluate the physical address, Compare between the one and two-dimensional ...

Compare between the one and two-dimensional memory organizations in terms of the  memory structure,  advantages, and disadvantages.  Which approach would better support the needs o

Explain about memory-management scheme, Q. In the IBM/370 memory protectio...

Q. In the IBM/370 memory protection is offered through the use of keys. A key is a 4-bit quantity every 2K block of memory has a key (the storage key) associated with it. The CPU

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd