As i understand all the page tables descriptors are stored in array mem_map. Each descriptor is less than 64 bytes long , mem_map requires about 4 Page frames for 1 MB of RAM.also check out MAP_NR. Correct guys ? Abhishek > --- Chandra G K Babu S <scgkiran@cse.iitk.ac.in> wrote: > > the answer is 8mb, may be that is a one level page > table. > the page size is 4kb (=4k * 1/8 = 1/2kB) > 32 bits of virtual address divided as 23+9, > first 23 bits give the page number, > the 9 bits give the index in a page. the page table > have to > accomdate (2 pow 23) entries so the page table size > is 8 mb. > > i think this question ha nothing to do with the > linux. > any comments? > > with regards, > kiran > On Mon, 6 Jan 2003, Rupa wrote: > > > > > Actually this was the question asked in some exam. > I do no how to calculate > > size of page table. They had given 4 answers... > > i)16mb ii)8mb > > iii)2mb iv) 24mb > > > > You have any idea? > > > > Regards, > > Rupa > > ----- Original Message ----- > > From: "Raghu R. Arur" <rra2002@cs.columbia.edu> > > To: "Rupa" <rupa.ramakrishna@ionidea.com> > > Sent: Monday, January 06, 2003 11:47 AM > > Subject: Re: size of page table > > > > > > > > > > Hi, > > > > > > If you are talking about linux, the page table > size is not related to the > > > memory size (RAM size). page table is for per > process and in linux each > > > process will have 4GB of memory allocated. 3 GB > for the user space and 1 > > > GB for the kernel space. > > > > > > HTH, > > > raghu > > > > > > On Mon, 6 Jan 2003, Rupa wrote: > > > > > > > Hello, > > > > I have small doubt regarding the sizeof > page table. Consider a > > machine with 64MB physical memory and a 32 bit > virtual address space. If the > > page size is 4kb, what is the approximate size of > page table.? > > > > Any help will be useful > > > > > > > > Rupa > > > > > > > > > > > -- > > Kernelnewbies: Help each other learn about the > Linux kernel. > > Archive: > http://mail.nl.linux.org/kernelnewbies/ > > FAQ: http://kernelnewbies.org/faq/ > > > > -- > A 105, Hall-IV > IIT Kanpur, > Pin- 208016, > Phone # > Dept. (0512) 597653, > Hostel (0512) 597114, > 597314 > > -- > Kernelnewbies: Help each other learn about the Linux > kernel. > Archive: > http://mail.nl.linux.org/kernelnewbies/ > FAQ: http://kernelnewbies.org/faq/ > __________________________________________________ Do you Yahoo!? Yahoo! Mail Plus - Powerful. Affordable. Sign up now. http://mailplus.yahoo.com -- Kernelnewbies: Help each other learn about the Linux kernel. Archive: http://mail.nl.linux.org/kernelnewbies/ FAQ: http://kernelnewbies.org/faq/
