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

NETWORK OPERATING SYSTEM, explain about design issues of network operating ...

explain about design issues of network operating system

Explain the spawnlp functions used in the netware, Explain the Spawnlp Func...

Explain the Spawnlp Functions Used in the NetWare Spawnlp(flags, execName, arg0,...)  The Spawnlp function is used to load  a NetWare executable file (NLM) specified by exec

Explain the entry-sequenced file organization, Entry-sequenced file organiz...

Entry-sequenced file organization The records in an entry-sequenced file are store up in the order they are written into the file. New records are for all time appended to

Producer – consumer process, Step by step displays the content, and the fin...

Step by step displays the content, and the final result of the list ("buffer") of 6 elements as the initial values ??and the following elements which are produced (NEXTP) or consum

Define a program that is in execution is known as, Define a program in exec...

Define a program in execution is known as A program in execution is known as a process

In JavaScript, Ask quesIn JavaScript, what is event handling tion #Minimum ...

Ask quesIn JavaScript, what is event handling tion #Minimum 100 words accepted#

Linux, Discuss the risks of having a single root user

Discuss the risks of having a single root user

Illustrate example for segmentation, EXAMPLE FOR SEGMENTATION Consider ...

EXAMPLE FOR SEGMENTATION Consider an instance as given in the table and we have five segments numbered from 0 through 4 the segment is stock in the physical memory as shown. Th

Demand paging, Demand paging With demand paging, a page is called into...

Demand paging With demand paging, a page is called into memory only when a location on that page is actually indexed during run time. With pre-paging, pages other than the one

Relationship among a(x, Q. The RC 4000 system as well as other systems hav...

Q. The RC 4000 system as well as other systems have defined a tree of processes (called a process tree) such that all the descendants of a process are given resources (objects) as

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