0 votes 0 votes Consider the system which has virtual address of 36 bits and physical address of 30 bits and page size of 8 KB, page table entry contain 1 valid bit, 2 protection bit and 1 reference bit. Then the approximate page table size in (MB) is ________. Operating System operating-system paging virtual-memory + – pream sagar asked Jan 23, 2019 • recategorized Jul 17, 2022 by Shubham Sharma 2 pream sagar 658 views answer comment Share Follow See all 8 Comments See all 8 8 Comments reply Deepanshu commented Jan 23, 2019 reply Follow Share hmm i am also going to add that but didnt 21 is real answer but they say 24 ....they take appox. thing too seriously 1 votes 1 votes pream sagar commented Jan 23, 2019 reply Follow Share if gate ask this type of question then i think 21 is correct than 24 0 votes 0 votes akash.dinkar12 commented Jan 23, 2019 reply Follow Share They will specify everything properly.. 0 votes 0 votes Swapnil Naik commented Jan 24, 2019 reply Follow Share @akash.dinkar12 A page entry should be padded if its not in byte, for 21 bits we should add 3 bits more to make it 3B entry, isn't this is a default thing why they need to specify? 0 votes 0 votes Manas Mishra commented Jan 24, 2019 reply Follow Share @Swapnil Naik we cannot pad by default , actually here said approximate pte size so they padded 0 votes 0 votes Swapnil Naik commented Jan 24, 2019 reply Follow Share Okay got it. 0 votes 0 votes Fyse commented Jan 24, 2019 i edited by Fyse Jan 24, 2019 reply Follow Share I think Page Table Entry should be padded. A similar question was asked in Gate which is as below. https://gateoverflow.in/739/gate2001-2-21 (Without padding the answer would have been 1.75 MB and using padding the answer is 2 MB) Also in many practical implementations, the Page table entry is rounded up as it is said in the below link. https://stackoverflow.com/questions/47525296/how-is-the-size-of-a-single-page-table-entry-affected-when-the-page-size-changes 0 votes 0 votes gauravkc commented Jan 24, 2019 reply Follow Share Agreed, Memories are word addressable. If the entries are not padded, accessing them will be difficult as the starting point of entry will be in between somewhere in a byte and not at the beginning at byte. 1 votes 1 votes Please log in or register to add a comment.