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

Explain the performance of demand paging, Performance of demand paging ...

Performance of demand paging Demand paging can have an important effect on the performance of a computer system. As long as there are no page faults, the effective access time

Changing the runlevel of system from 5 to 3 on startup, Front page We n...

Front page We need to continue or customization and documentation of our system. Currently our system boots into runlevel 5 and we need it to boot into runlevel 3. For future r

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

How can the deadlock be prevented-bankers algorithm, How can the deadlock b...

How can the deadlock be prevented Bankers algorithm : The Resource allocation graph algorithm isn't applicable to a resource allocation system with multiple instances of every

Aggregate planning, Prepare a report that motivates alternatives reactive s...

Prepare a report that motivates alternatives reactive strategies that can be used by wind Mud clothing factory

Explain single partition allocation., Operating Systems 1. Explain sing...

Operating Systems 1. Explain single Partition Allocation and Multiple Partition Allocation. 2. What do you mean by PCB? What useful information is available in PCB? 3. De

What are the main challenges for mobile computing, Question: (a) What ...

Question: (a) What are the main challenges for Mobile Computing? (b) What is the ISM band and what is particular about this frequency band? Name two wireless technologies

Could you replicate a multilevel directory structure, Q. Could you replica...

Q. Could you replicate a multilevel directory structure with a single-level directory structure in which arbitrarily long names can be used? If your answer is yes describe how you

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

Key piece of information stored in single page table entry, Define which is...

Define which is not a key piece of information, stored in single page table entry, supposing pure paging and virtual memory  A reference for the disk block which stores the pa

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