MadeEasy Test Series: Operating System - Process Schedule

Question

Comments

yes you are right how do you get it dear??please explain me

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19 answer

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@magma will you please share the solution.

Answer 1

Ans is 19.67 

I hope it's understandable..but if any doubts than ask me

Comments

Program 2 arrived at 3 then why didn't it preempted program 1 at that instant only?

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Because priority ( program 2) > priority (program 1)

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@Magma that is what Shivam Kasat is saying if priority ( program 2) > priority (program 1) then program1 should be preempted ?

Answer 2

program 1	Program 2	Program 3
a =2m	a =2m	a =2m
b=3m	b=3m	b=3m
c =4m	c =4m	c =4m

Gantt Chart For Program(Completion time )

P1a

P1b

P1c

P2a

P2b

P2c

P2a

P2b

P2c

P2b

P3a

P3b

P3c

P3a

P3b

P3c

P3c

P2

P1a

P2b

P2c

P2c

P

P

P

0----1-----2----3------4-----5-----6-----7-----8-----9----10----11----12---13----14---15---16--18--21---22---23---24-----27

Program	Arrival time	Completion time	Turn Around time	Priority time
1	0	27	27	1 (low )
2	3	25	22	5
3	10	19	9	10(high)

 

TAT= (22+9+27)/3=19.33

plz check and correct me if i wrong .. 

Comments

why did you used round robin? In the question it is given that priority preemptive scheduling is used.

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in preemptive scheduling, we used to run the process for only one unit of time, than we preempt the process ..

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Could you please provide any refernere for your statement!

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read the preemptive algorithms.. in the no preemptive we run the process upto burst time and in round-robin we run up to slice time /quantum time