Fcfs scheduling algorithm, Operating System

Assignment Help:

Q. Presume that the following processes arrive for execution at the times indicated. Every process will run the listed amount of time. In responding the questions use non pre-emptive scheduling and base all decisions on the information you have at the time the decision must be made.

780_FCFS scheduling algorithm.png

a. What is the average revolve time for these processes with the FCFS scheduling algorithm?

b. What is the average revolve time for these processes with the SJF scheduling algorithm?

c. The SJF algorithm is supposed to improve performance however notice that we chose to run process P1 at time 0 because we did not know that two shorter processes would arrive soon. Calculate what the average turnaround time will be if the CPU is left idle for the first unit and then SJF scheduling is used. Keep in mind that processes P1 and P2 are waiting during this idle time thus their waiting time may increase. This algorithm could be recognized as future-knowledge scheduling.

Answer:

a. 10.53

b. 9.53

c. 6.86

Keep in mind that turnaround time is finishing time minus arrival time so you have to subtract the arrival times to compute the turnaround times. FCFS is 11 if you overlook to subtract arrival time.


Related Discussions:- Fcfs scheduling algorithm

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

Prevention of a data race in a parallelised program, Present your own fully...

Present your own fully documented and tested programming example illustrating the prevention of a data race in a parallelised program. This is an example where total number of p

Explain advantages and inconveniences of ult, ADVANTAGES AND INCONVENIENCES...

ADVANTAGES AND INCONVENIENCES OF ULT Advantages: Thread switching doesn't involve the kernel - no mode switching Scheduling is able to be application specific -

Explain additional-reference-bits algorithm, Additional-reference-bits algo...

Additional-reference-bits algorithm We can keep an 8-bit byte for every page in a table in memory. The operating system shifts the reference bits right 1 bit, discarding the lo

Explain multi-user based operating system, Multi-user - A multi-user Opera...

Multi-user - A multi-user Operating System permits for multiple users to use the same computer at the same time and/or different times. Below are some instances of multi-user Op

Replacement algorithm for tlb, Consider the following C program where M, N,...

Consider the following C program where M, N, K are predefined constants. Assume int is 4 bytes. Suppose this program is run on a machine with 4KB page size and 32 TLB entries. Init

Allocating new pages, Processes have valid and invalid entries on their pag...

Processes have valid and invalid entries on their page tables. The valid entries all point to some where "real" (e.g. a physical page, or some portion of disk in case of non-reside

What is meant by the phrase thread-safe, The term thread-safe in computer p...

The term thread-safe in computer programming describes that routine or portion of the program that may be called from multiple programming threads without uncalled for interactions

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

Describe the differences among short-term and medium-term, Describe the dif...

Describe the differences among short-term, medium-term, and long-term scheduling.   Short-term (CPU scheduler)-selects from jobs in memory those jobs that are ready to execu

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