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

What is the sequence in which resources may be utilized, What is the sequen...

What is the sequence in which resources may be utilized? Under normal mode of operation, a process may utilize a resource in the following sequence: Request: If the requ

Explain the communications of request or response interface, Explain the Co...

Explain the Communications of Request or Response Interface The inter-application communication must provide four specific interface to the CSInterface() components. A client m

Operating system structure, Problem: (a) Modern operating systems are i...

Problem: (a) Modern operating systems are interrupt driven. If there are no processes to execute, no I/O devices to service, and no users to whom to respond, an operating syste

Define the tlsfree(tlsindex) function, Define the TlsFree(TLSIndex) Functio...

Define the TlsFree(TLSIndex) Function This function should be called to free a TLSindex allocated by TlsAlloc. It would be executed when there are no more threads in a process

Explain variable partitioning technique, VARIABLE PARTITIONING We can d...

VARIABLE PARTITIONING We can differ the partitions and change the location according to the size of the process. Here if a 10k process enters we are able to make a space of

Advanced synchronization in operating system, Recall that condition variabl...

Recall that condition variables are synchronization primitives that enable threads to wait until a particular condition occurs. Generalizing, the combination of locks and condit

Mechanism for code and data sharing, Q. Consider a system in which a progr...

Q. Consider a system in which a program is able to be separated into two parts: code and data. The CPU recognizes whether it wants an instruction (instruction fetch) or data (data

Explain medium term scheduling, Medium term scheduling This is componen...

Medium term scheduling This is component of the swapping function. Usually the swapping in decision is based on the need to manage the degree of multiprogramming. At a system t

Exdplain many-to-many model, Many-to-Many Model The many-to-many model-...

Many-to-Many Model The many-to-many model- many user-level threads to many kernel-level threads avoids several of the limitations of the one-to-one model, although extending mu

Describe services of operating systems, (a) Describe services of operating ...

(a) Describe services of operating systems. (b) Differentiate among the short term, medium term and long term scheduling that are given by multi-tasking operating systems.

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