0 0 votes Calculate the percentage of CPU idle time. Operating System + – Balaji Jegan 2.0k views answer comment Share Follow Print See all 18 Comments 18 18 Comments reply Balaji Jegan commented Oct 19, 2018 reply Follow flag I am getting 21.05% 0 0 replyShare Balaji Jegan commented Oct 19, 2018 reply Follow flag Is this correct? 0 0 replyShare Hemanth_13 commented Oct 19, 2018 reply Follow flag Yes, I am getting the same (21.05% )considering all the processes are available at time zero. 0 0 replyShare Balaji Jegan commented Oct 19, 2018 reply Follow flag some people are saying answer is 33.33% 0 0 replyShare Balaji Jegan commented Oct 19, 2018 reply Follow flag Assume Arrival Time = 0 for all processes 0 0 replyShare Magma commented Oct 19, 2018 reply Follow flag I got 26.82 % Is it correct ?? 1 1 replyShare Magma commented Oct 19, 2018 reply Follow flag Hemanth_13 why you're not add last 6 unit I/O time of P3 ?? 0 0 replyShare Balaji Jegan commented Oct 19, 2018 reply Follow flag Magma Question says "CPU" Idle time 0 0 replyShare Hemanth_13 commented Oct 19, 2018 reply Follow flag @Magma we can schedule some other process during that time as our work(none of the give processes were in queue) was done and CPU is now free to accept others. 0 0 replyShare Magma commented Oct 19, 2018 i edited by Magma Oct 19, 2018 reply Follow flag since we're talking about the gnatt chart , we're talking about the entire schedule where total amount of time to complete all the process , and In that given case CPU is remain Idle for 6 units of time therefore we should include it !! 0 0 replyShare Magma commented Oct 19, 2018 reply Follow flag Hemanth_13 My question is P3 is complete it's CPU execution at 76 units of time right ?? then 6 units of i/o time also remains ...why shouldn't we include it ??? 0 0 replyShare Hemanth_13 commented Oct 19, 2018 reply Follow flag We are releasing the CPU when our work is done. At 76 units of time we are done with CPU work so we gave off CPU. 0 0 replyShare MiNiPanda commented Oct 19, 2018 reply Follow flag I am having the same doubt here whether to include the 6 units or not. Since there are no processes available in the system other than these 3 so even if CPU is set free it will remain idle. CPU time is the amount of time for which CPU remains engaged as opposed to "elapsed time, which includes for example, waiting for input/output (I/O) operations or entering low-power (idle) mode." When P3 is having I/O bursts, will CPU know that P3 won't be coming back to it after finishing? No isn't it? It will be waiting for P3 to complete it's I/O. See this process diagram: There isn't any path from waiting to terminated directly connecting them. A process has to pass through the CPU to go to terminated state.(I guess this CPU time is too negligible that is why it is not considered). So CPU has to wait for P3 to finish it's I/O and during that time remains idle. Any argument against this reasoning is appreciated. 1 1 replyShare Hemanth_13 commented Oct 19, 2018 reply Follow flag https://gateoverflow.in/1843/gate2006-65 By looking the above previous gate question we have to consider the P3 idle time as well. 0 0 replyShare Hemanth_13 commented Oct 19, 2018 reply Follow flag https://www.youtube.com/watch?v=FKyFuP_qvBM Here we can cpu has been released after its work I feel logically this is correct. But I have the below argument as well for considering that 6 units of time. after the completion of CPU time of P3 it is moved to suspended state. So we have medium scheduler which moves it Ready state after I/O is done from suspended state. Now short term scheduler gives it CPU(running state) as nothing needs to be done it is moved to terminated state. 0 0 replyShare ank73811 commented Oct 19, 2018 reply Follow flag which scheduling algo is used 0 0 replyShare Hemanth_13 commented Oct 19, 2018 reply Follow flag ank73811 shortest remaining time first algo 0 0 replyShare Shaik Masthan commented Oct 19, 2018 reply Follow flag after completion of I/O, it should come to Ready State and scheduled and runs 0 unit times. 0 0 replyShare Please log in or register to add a comment.
