0 votes 0 votes In a single core processor, with Round Robin scheduling, how does the CPU keep track of time when a time quantum expires and brings in another process? PriDix asked Jun 9, 2017 PriDix 469 views answer comment Share Follow See all 0 reply Please log in or register to add a comment.
2 votes 2 votes CPU don't actually keep track of the time. Let the scheduling algorithm is Round Robin then when the process has done with the time quantum time (Round Robin scheduling has it's fixed time quantum time) Then According to algorithm there would be an Interrupt generated (Time slice complete interrupt) and then the Short Term scheduler then schedule new process from ready queue. tell me if something is not clear yet. Rupendra Choudhary answered Jun 9, 2017 Rupendra Choudhary comment Share Follow See all 6 Comments See all 6 6 Comments reply Sahil1994 commented Dec 8, 2017 reply Follow Share @Rupendra Choudhary Then sir what is the role for mid term scheduler..? for suspend ready and suspend wait..? 0 votes 0 votes Rupendra Choudhary commented Dec 10, 2017 reply Follow Share Hello Sahil Mid Term Scheduler's (MTS) job is to swap out processes from physical memory to swap space when doing this can increase the performance of our system. 0 votes 0 votes Sahil1994 commented Dec 11, 2017 reply Follow Share @Rupendra chaudhary basically then all 3 schedulers effect the performance of the system Am i right..?? Long term brings process from job pool to ready queue(CPU BOUND OR I/O BOUND PROCESSES) Short term for context switching b/w the processes while executing. Mid term for swap out processes from physical memory to swap space. 0 votes 0 votes Rupendra Choudhary commented Dec 11, 2017 reply Follow Share No.Short Term Scheduler (CPU Scheduler) has nothing to do with context switching. STS only select which process to allocate CPU after receiving kind of signal(interrpt) that means , hey! you STS select which process to pick from ready queue for actal execution. It's Dispatcher , OS modle which deals with context switching and actually allocate CPU to selected process by STS. read more here https://en.wikipedia.org/wiki/Scheduling_(computing) 0 votes 0 votes Sahil1994 commented Dec 11, 2017 reply Follow Share Ok thanks @RupendraChaudhary sir got your point but u didn't answere that all 3 schedulers effect the performance of the system..?? 0 votes 0 votes Rupendra Choudhary commented Dec 11, 2017 reply Follow Share This is an trivial question sahil.They are schedulers so of course if they don't do their work properly , system performance will have to suffer. Or in another way tell me what do you mean by system performance then i can be more specific. STS speed must be fast enough because CPU do it's work very quickly. If there is less physical memory and MTS is not swapping then it's an bad impact on multiprogramming. It's responsibility of LTS to select combination of i/o bound and cpu bond processes in that way system performance will be good. 0 votes 0 votes Please log in or register to add a comment.