2 votes 2 votes If there is 2 or more level paging for processes, is it possible to have more than 1 page fault while accessing any single addressable unit(byte or word) ? Operating System operating-system virtual-memory memory-management paging + – 3lurryface asked Jan 9, 2019 • edited Jan 9, 2019 by 3lurryface 3lurryface 1.1k views answer comment Share Follow See all 0 reply Please log in or register to add a comment.
3 votes 3 votes No. Because page table access never page faults. All the page table entries will always be in main memory. But a single instruction can cause multiple page faults if it involves multiple memory operands. Arjun answered Jan 9, 2019 Arjun comment Share Follow See all 10 Comments See all 10 10 Comments reply 3lurryface commented Jan 10, 2019 reply Follow Share So this means all the inner page tables of process will reside in physical memory all the time to prevent successive page faults while performing any fetching operation. 0 votes 0 votes Arjun commented Jan 10, 2019 reply Follow Share Yes. If any inner level page table is not used by the process then it won't be loaded. That's why we have questions where the process memory usage will be given and asked for page table size. 0 votes 0 votes Shaik Masthan commented Jan 12, 2019 reply Follow Share @Arjun sir, as per me, if we have atleast one page from each level, then we can run the process, then page fault may occur. But you are saying all pages of page table should be in memory, this lead to contradiction my concept. Where i am going wrong ? 0 votes 0 votes 3lurryface commented Jan 13, 2019 reply Follow Share I have exact same doubt sir. 0 votes 0 votes Arjun commented Jan 13, 2019 reply Follow Share @Shaik Masthan What do you mean by "one page from each level"? In each level we have page tables. Now, number of page tables used by any process varies and they can have different number of page tables in each level. But, if a process uses say 100 page tables across all levels, then these 100 must be present in physical memory when that process is running. Or page table access can NEVER page fault. Because then the normal page fault mechanism cannot work. I'll discuss this soon, the slides for this must be on GO classroom. 0 votes 0 votes Shaik Masthan commented Jan 14, 2019 reply Follow Share the slides for this must be on GO classroom sir, i will check it there 0 votes 0 votes G Phalkey commented Jan 15, 2019 reply Follow Share but sir we load only required part of process to increase degree of multiprogramming ,so in between execution page which is not loaded previously need to be loaded .so why not then page fault??? 0 votes 0 votes manisha11 commented Feb 18, 2019 i edited by manisha11 Feb 19, 2019 reply Follow Share doubtful for the answer Sir 0 votes 0 votes Arjun commented Feb 18, 2019 reply Follow Share What is your doubt? 0 votes 0 votes manisha11 commented Feb 19, 2019 reply Follow Share In case of an instruction that is split into many words, we may have multiple page faults, but for a single word, we can have a max 1-page fault as when we access all the PT are in memory? Is that the essence of your answer? 0 votes 0 votes Please log in or register to add a comment.