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

Define the client - server communications environment, Define the Client - ...

Define the Client - Server Communications Environment Today's client - server communications environment offers programmers great flexibility for application design. Applicatio

Implementing group policies in a windows environment, Question: (a) As...

Question: (a) As a System administrator, elaborate on how you can manage computer accounts in Active Directory of Windows Server 2008? (b) Explain the following user p

Explain about error detection method, Q. Explain about Error detection meth...

Q. Explain about Error detection method? Error detection: error can occur in CPU, in I/O devices or in memory hardware. Operating system constantly needs to be aware of possi

What problems arise if the directory is a general graph, What problems aris...

What problems arise if the directory structure is a general graph? Searching for a particular file may result in searching the similar directory many times. Deletion of the fil

Characteristics of suspend process, Characteristics of suspend process ...

Characteristics of suspend process Suspended process isn't immediately available for execution. The process may or may not be waiting on an event. For preventing t

Determine a parser which is a variant of top-down parsing, Determine a pars...

Determine a parser which is a variant of top-down parsing without backtracking Recursive Descend parser is a variant of top-down parsing without backtracking.

List the various file attributes, List the various file attributes. A f...

List the various file attributes. A file has particular other attributes, which vary from one operating system to another, but typically having of these:  Name, identifier, typ

What is multiprogramming, Q. What is Multiprogramming? Multiprogrammin...

Q. What is Multiprogramming? Multiprogramming When two or more programs are in memory at the same instance, sharing the processor is referred to multiprogramming opera

What is a latency time, What is a Latency Time Latency Time is the time...

What is a Latency Time Latency Time is the time required through a sector to reach below read/write head.

What are tree-structured directories, What are Tree-structured directories ...

What are Tree-structured directories We can generalize the directory structure to a tree of arbitrary height. This permits the user to create their own sub directories and to c

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