ISRO2011-55

Question

There are three processes in the ready queue. When the currently running process requests for I/O how many process switches take place?

• A. 1
• B. 2
• C. 3
• D. 4

Comments

ya it is two

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@Arjun Sir check this qus.I already written same ans as given in pdf .I changed it .

Is process switch is same as context switch.?

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i think i got the clue....here in above question  process switching...is not same context switching.....

thatswhy...they mentioned....

" SOMETIMES" CONTEXT SWITCHING IS  REFFERED AS  PROCESS SWITCHING"  that means not always ......check it

http://www.linfo.org/context_switch.html

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@arjun sir please clarify what's the correct answer.

Answer 1

For me its 2 switchings. On requestiong I/O, the process will be shifted to wait queue and the CPU time will be allotted to the very next process in the ready queue. So two switching.

Answer 2

Correct Answer is two context switches. first , from running to block state for IO, 2nd, from ready queue to running .

Answer 3

Option (b) 2 is correct. First context switch will happen when we move the currently executing state to blocked state. Second, to move the process of ready queue to execute state after serving the I/O request. So, 2 context switches will be required. Hope this helps.