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

Explain multiprocessing operating system, Multiprocessing - An Operating S...

Multiprocessing - An Operating System proficient of utilizing and supporting more than one computer processor. Below are some instances of multiprocessing Operating Systems. Li

Describe demand-paged environment, Q. Which of the subsequent programming ...

Q. Which of the subsequent programming techniques and structures are good for a demand-paged environment? Which aren't good? Describe your answers. a. Stack b. Hashed symbol

Define the windowsnt, Define the WindowsNT WindowsNT provides a two-lev...

Define the WindowsNT WindowsNT provides a two-level approach to resource management: process and thread. The process is the uppermost level and contains most of the application

Define ageing, Define Ageing Ageing is a method of enhancing the priori...

Define Ageing Ageing is a method of enhancing the priority of process waiting in Queue for CPU allocation

Perform alpha-beta pruning on the following tree, Perform alpha-beta prunin...

Perform alpha-beta pruning on the following tree. Put an "X" over each node that is pruned. Put the final value next to all other nodes. Indicate which action MAX should take: to B

Page faults, Assume there are only 4 page frames in the physical memory, fo...

Assume there are only 4 page frames in the physical memory, for the following reference string: 1, 2, 3, 4, 5, 3, 4, 1, 6, 7, 8, 7, 8, 9, 7, 8, 9, 5, 4, 5, 4, 2, 8. a) What i

Unsafe state in a deadlock-avoidance system, Question: A set of process...

Question: A set of processes are in a deadlock state when every process in the set is waiting for an event that can be caused by only another process in the set. (a) There

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