27 votes 27 votes In a system with $\text{32 bit}$ virtual addresses and $\text{1 KB}$ page size, use of one-level page tables for virtual to physical address translation is not practical because of the large amount of internal fragmentation the large amount of external fragmentation the large memory overhead in maintaining page tables the large computation overhead in the translation process Operating System gatecse-2003 operating-system virtual-memory normal + – Kathleen asked Sep 16, 2014 edited Jun 23, 2018 by Pooja Khatri Kathleen 15.2k views answer comment Share Follow See all 3 Comments See all 3 3 Comments reply minal commented Nov 14, 2015 reply Follow Share https://gateoverflow.in/916/gate2003_26#viewbutton 0 votes 0 votes JashanArora commented Mar 6, 2020 reply Follow Share If we consider a byte addressable system, we'll get $\frac{2^{32}B}{2^{10}B}=2^{22}= 4 \ million$ entries for pages of a single process. If we choose a modest number, and say our process has $100$ pages, then the entries for pages $101$ to $4000000$ would look like this: $\text{Page i}$ $\text{<Not in any frame>}$ This means most of the entries in our page table are useless. Even for a process that only needs just one page in totality, 4 million entires would have to be made and maintained. This is a monstrous overhead. 5 votes 5 votes Aalok8523 commented Jul 4, 2020 reply Follow Share i think that option D also should be true beside of option C because if we use one level page table then that page table have 2^22 entries and for finding required PTE for given VA, we have to compare first 22 bits of VA with index bits of each page table entry (that is of size 22 bits) in sequential manner. So, translation of VA to PA should be difficult. VA - virtual address PA - physical address 0 votes 0 votes Please log in or register to add a comment.
–4 votes –4 votes Option a is right but option c should als be right as huge no of pages will make managing page tables an overhead. anshu answered Feb 3, 2015 anshu comment Share Follow See all 0 reply Please log in or register to add a comment.
–5 votes –5 votes Here Number of pages will be 2^32/2^10= 2^20 Hence, Number of pages is much in number,thus chances to internal fragementation due to size of pages is larger,then overhead is reduced. So answer will be option A. rpdhakad answered Jul 20, 2015 rpdhakad comment Share Follow See all 0 reply Please log in or register to add a comment.