1 votes 1 votes Operating System operating-system process-scheduling made-easy-test-series + – jatin khachane 1 asked Jan 12, 2019 • edited Mar 4, 2019 by ajaysoni1924 jatin khachane 1 1.3k views answer comment Share Follow See all 14 Comments See all 14 14 Comments reply himgta commented Jan 23, 2019 reply Follow Share @Shaik Masthan @MiNiPanda For executing the processes do we have to consider the entire burst time or the burst time before I/O request 0 votes 0 votes MiNiPanda commented Jan 23, 2019 reply Follow Share The time spent in doing I/O should not be of considered as a part of waiting time. Only the time spent in waiting in the ready queue accounts for the WT. So waiting time=Completion time -( CPU burst+IO burst+Arrival time) Wt(P1)=7, Wt(P2)=0, Wt(P3)=4, WT(P4)=4 Avg =11/4=2.75 Ans given is 5.5 but that is done in the incorrect way. I will comment the link of reference. Let me search it. I checked this just 2days back :P My confusion is with the last sentence "consider only the CPU times as burst one" What does it mean? :/ 0 votes 0 votes MiNiPanda commented Jan 23, 2019 reply Follow Share https://gateoverflow.in/75241/scheduling See the selected ans. The 2nd answer followed the same approach as made easy which wasn't approved by Arjun Sir as you can see from his comments 0 votes 0 votes himgta commented Jan 23, 2019 reply Follow Share @MiNiPanda and what about efficiency ,they have given 100%,is that correct? 0 votes 0 votes Shaik Masthan commented Jan 23, 2019 reply Follow Share @MiNiPanda Can you please share your opinion on the question https://gateoverflow.in/295889/cpu-scheduling-srtf 0 votes 0 votes MiNiPanda commented Jan 25, 2019 reply Follow Share @Shaik Masthan The link you attached has the same question right..? I have seen this question before and then searched it on the net..then got that link (which I attached). There the approach followed was different. 0 votes 0 votes Shaik Masthan commented Jan 25, 2019 reply Follow Share the link which you attached, " selecting a process for running, having criteria on Priority. " So there is no problem, But in this question criteria is " Shortest Burst time ", so confusion arises ! 0 votes 0 votes MiNiPanda commented Jan 25, 2019 reply Follow Share But ultimately we have to calculate the waiting time na? According to the solution of ME, the time spent on doing I/O is also considered as part of the waiting time while in the definition says that WT is the time spent by a process in the ready queue (and not in the IO) waiting for its turn to come. 0 votes 0 votes Shaik Masthan commented Jan 25, 2019 reply Follow Share Forget about waiting time ! actually my doubt is :- after some time of scheduling, Now let P1 is required 1 BT, before going to I/O, and 5 BT after completion of I/O and it is available in Ready Queue. let P2 is required 2 BT after completing I/O and available in Ready Queue. Now is Short term Scheduler based on SRTF, which one will allow to run, is P1 or P2 ? is considering, P1 requires 1 BT or P1 requires (1+5) BT ? where P2 requires 2 BT. 0 votes 0 votes MiNiPanda commented Jan 25, 2019 reply Follow Share @Shaik Masthan If both arrives in the ready queue at the same time, then the one with shorter CPU burst will be given preference in case of SRTF..and if the bursts are same then the one having older process id will be given the priority. 0 votes 0 votes Shaik Masthan commented Jan 25, 2019 reply Follow Share you didn't get me correctly ! just leave it ! 0 votes 0 votes Somoshree Datta 5 commented Jan 25, 2019 reply Follow Share MiNiPanda So according to the example provided by Shaik, P1 should be scheduled right? 0 votes 0 votes MiNiPanda commented Jan 25, 2019 reply Follow Share Okay as you wish :) 0 votes 0 votes MiNiPanda commented Jan 25, 2019 reply Follow Share @Somoshree Datta 5 Yes.. 0 votes 0 votes Please log in or register to add a comment.
0 votes 0 votes 5.5ms and 100percent efficiency Himanshu555 answered May 29, 2022 Himanshu555 comment Share Follow See 1 comment See all 1 1 comment reply 0xprateek commented May 29, 2022 reply Follow Share I have calculate waiting time as ; p1 – 10 p2 – 4 p3 – 7 p4 – 2 average waiting time 5.7 How you are getting 5.5 ? 0 votes 0 votes Please log in or register to add a comment.