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 why sstf scheduling tends to favour middle cylinder, Q. Describe w...

Q. Describe why SSTF scheduling tends to favour middle cylinders over the innermost and outermost cylinders. Answer: The middle of the disk is the location having the smalles

Define shell in unix system, A Unix shell is a shell or command-line inte...

A Unix shell is a shell or command-line interpreter that gives a traditional user interface for the Unix-likesystems and for Unix operating system. Users operates the operation of

Define the sleep (sec) function, Define the Sleep (sec) Function Sleep ...

Define the Sleep (sec) Function Sleep function suspends execution of this process for sec number of seconds. While this function is used in our example for consistency, other f

Operation management, trace the historical evolution of the operations mana...

trace the historical evolution of the operations managent from themainly rural agricultural era of the artisans to the present day industrial revolution, high technoligical advance

Explain the purpose of command-line application, Question: a) The follo...

Question: a) The following questions refers to Windows XP networking: i) Briefly, explain how a host joins a network using DHCP? ii) Which IP address could be assigned to a

What is paging? , What is paging? Paging is a memory management schem...

What is paging? Paging is a memory management scheme that authorizes the physical-address space of a process to be noncontiguous. Paging evades the considerable problem of fi

Explain memory management using bit maps, MEMORY MANAGEMENT USING BIT MAPS ...

MEMORY MANAGEMENT USING BIT MAPS   In this memory is separated into different allocation units each of some particular size(a few bites).consider every space of size 4k. A

Garbage collection, The dynamic memory allocator is a layer between the app...

The dynamic memory allocator is a layer between the application and the OS, managing heap objects. When a program requests memory from the allocator (via malloc(), for instance), t

What is a client server system, What is a client server system? Central...

What is a client server system? Centralized systems proceed as server systems to satisfy request generated by client systems Server system is able to be broadly div

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