0 votes 0 votes Consider a system using demand paging architecture it takes $3ms.$ to service page fault if either empty frame is available or replaced page is not to be modified takes $10ms.$ if replaced page is modified. Main Memory access time is $1ms.$ and page to be replaced is modified $60$% of time. The maximum acceptable page fault rate to get effective memory access time not more than $4ms.$ is_________(%) Operating System operating-system made-easy-test-series page-fault + – srestha asked May 15, 2019 srestha 680 views answer comment Share Follow See all 0 reply Please log in or register to add a comment.
Best answer 3 votes 3 votes Let the page fault rate be $p$, then $ \Rightarrow p \times [0.4 \times 3 ms + 0.6 \times 10 ms] + (1-p) \times 1 ms \leq 4 ms$ $\Rightarrow 6.2p = 3$ $\Rightarrow p = 48 \% $ !KARAN answered May 15, 2019 selected May 16, 2019 by srestha !KARAN comment Share Follow See all 3 Comments See all 3 3 Comments reply Raj_81 commented Aug 10, 2019 reply Follow Share why don't you add the memory access time at the time of page fault? b'coz in the time of page first we service the page and the access main memory. correct me if I am wrong 0 votes 0 votes !KARAN commented Aug 10, 2019 reply Follow Share From the time when page fault occurs to handling of the page fault is called page fault service time. That's why here no need to add memory access time 2 votes 2 votes lalitver10 commented Mar 9, 2022 reply Follow Share We should include page table access time since that time is not included in PFST. 0 votes 0 votes Please log in or register to add a comment.