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

Catalogue the design goals of windows xp, Q. Catalogue the design goals of ...

Q. Catalogue the design goals of Windows XP. Answer: Design goals comprise security and reliability and Windows and POSIX application compatibility with high performance and ex

Differences between symmetric and asymmetric multiprocessing, Describe the ...

Describe the differences between symmetric and asymmetric multiprocessing. What are three advantages and one disadvantage of multiprocessor systems? Symmetric multiprocessing t

Selection of a disk-scheduling algorithm, Q. How would utilize of a RAM di...

Q. How would utilize of a RAM disk affect your selection of a disk-scheduling algorithm? What factors would you require to consider? Do the similar considerations apply to hard-di

Why high level languages need compiler, Q. Why High level languages need Co...

Q. Why High level languages need Compiler? High level languages - illustrations are COBOL, FORTRAN, PL/I andALGOL - are processed by interpreters andcompilers. A compilers is a

What is page fault, Problem: a) The CPU can access 2 storage devices di...

Problem: a) The CPU can access 2 storage devices directly. What are these 2 storage devices? b) Define 2 key issues involved in memory management. c) How do processes sha

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

Comparison of disk scheduling algorithms, COMPARISON OF DISK SCHEDULING ALG...

COMPARISON OF DISK SCHEDULING ALGORITHMS Name      Description                  Remarks      (Selection according to requestor)   RSS        Random scheduling     fo

Unix process api, Unix process API The two most important function calls...

Unix process API The two most important function calls to use when programming with several processes are fork and exec:  fork() creates a copy of current process. It gives

Explain peterson''s solution for the critical section problem, Explain the ...

Explain the Peterson's solution for the critical section problem? In Peterson's solution two variables a) flag and b) turn are used as shared variables. If the both shared vari

Define a policy for data storage, Produce a referenced four page report whi...

Produce a referenced four page report which describes the possible functionality of the system; similar systems that are out there and different possible approaches to delivering t

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