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

What is the translation look aside buffer (tlb), Translation Look aside Buf...

Translation Look aside Buffer In a cached system, the base addresses of the last few indexed pages is maintained in registers named the TLB that adds in faster lookup. TLB has

Explain schemes for defining the logical structure, What are the most commo...

What are the most common schemes for defining the logical structure of a directory? The most common schemes for explaining the logical structure of a directory Single-L

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

What do you understand by active directory domain, Question: a) What ...

Question: a) What do you understand by Active directory domain in Windows Server 2008? Support your answer with a diagram. b) Distinguish between active directory trees

Explain the exit (status) function, Explain the Exit (status) Function  ...

Explain the Exit (status) Function  Exit function causes the calling process to be terminated. Actually, all file descriptors are immediately closed but the process is   not

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

Explain threads in details?, What are threads? A thread - sometimes c...

What are threads? A thread - sometimes called as an implementation context or a lightweight process - is a single sequential flow of control within a program. We use threads

Explain segmentation hardware?, Explain segmentation hardware? We defin...

Explain segmentation hardware? We define an completion to map two-dimensional user-defined addresses into one-dimensional physical addresses. This mapping is affected by means

How can the index blocks be implemented, How can the index blocks be implem...

How can the index blocks be implemented in the indexed allocation scheme? The index block can be implemented as follows a. Multilevel scheme b. Linked scheme c. Combin

Define the term system software, Question: (a) Define the term system ...

Question: (a) Define the term system software and application software, giving an example for each. (b) Draw a diagram to represent the abstract view of a computer system i

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