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A system has 6 identical resources and N processes competing for them. Each process can request at most 2 resources. Which one of the following values of N could lead to a deadlock?

A system has 6 identical resources and N processes competing for them. Each process can request at most 2 resources. Which one of the following values of N could lead to a deadlock? Correct Answer 6

Data:

Available identical Resources = R = 6

Max needs per process = 2

Concepts:

Deadlock can occur If any process gets available resource < needed (requested) resource

Max resource per process to be in deadlock = needed – 1 = 2 – 1 = 1

For N process, max resource to be in deadlock = N × 1 = N

Condition for deadlock

N ≥ R

N ≥ 6

values of N could lead to a deadlock is 6

Explanation:

As there are 6 identical resources and Max requirement is 2, hence Max. number of process can be allowed is

[ alt="ya07" src="//storage.googleapis.com/tb-img/production/17/03/ya07.JPG">

But when the number of process is more than 5

[ alt="ya08" src="//storage.googleapis.com/tb-img/production/17/03/ya08.JPG">

Important Point:

In GATE, option 4 is 4, which won't give the correct answer and hence option 4 has been changed to 6

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