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

Describe paging algorithm needs a reference bit, Q. Suppose that you want ...

Q. Suppose that you want to utilize a paging algorithm that requires a reference bit (such as second-chance replacement or working-set model) however the hardware does not provide

Define an assembly language, Define an assembly language  Assembly lan...

Define an assembly language  Assembly language stands for a Low level programming language

Is data in a file access sequentially or randomly, Q. Give an instance of ...

Q. Give an instance of an application in which data in a file should be accessed in the following order: a. Sequentially b. Randomly Answer: a. Print the content of

Multiprogramming., In a multiprogramming and time sharing environment sever...

In a multiprogramming and time sharing environment several users share the system simultaneously .what are two such problems?

Inter-process Communication !, My code it didn''t run properly ,i tried to ...

My code it didn''t run properly ,i tried to pass 2 parameter example : ./a.out ls -ll ,but it execute only the ls instead of the ls -ll ! plz help amd thank you ! #include #inclu

Explain inverted page table, Inverted page table In page table the page...

Inverted page table In page table the page table has one entry for every page that the process is using. The operating system must translate this reference into a physical memo

Explain what type of group scope you will use, Question: (a) The actual...

Question: (a) The actual use and scope groups depend on the mode in which a domain is running. There are two domain modes in which you can run a Windows 2000 domain. List and d

Can page tables be set up to replicate base registers, Q. We have an OS (o...

Q. We have an OS (operating system) for a machine that uses base and limit registers however we have modified the machine to provide a page table. Can the page tables be set up to

Explain the basic concepts of segmentation, Explain the basic concepts of s...

Explain the basic concepts of segmentation. Segmentation definition User view of program Hardware used with diagram-segment table, base, limit & offset Protection and

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