hi Raj, I am now getting a little bit more sense about it. here is my basic thoughts: for RAM < 896 MB physical address 0 <==> virtual address 0xc0000000 and thats what virt_to_phys & phys_to_virt do ( so do __pa and __va). Every physical page frame is mapped by a struct page that records the page frame's information and you can find the page via mem_map+pfn, ie pfn_to_page. for 896 MB < RAM < 4096MB the *virtual field will record the corresponding virtual address if the given mapped physical address is larger than 896MB. does that the way kernel work ? correct me plz if I am wrong. (will discuss more details after thes basics) btw, I cant find any function or macro called rmap, is that kunmap you mean ? I need to dig more about this topic, its getting instresting. -- Kernelnewbies: Help each other learn about the Linux kernel. Archive: http://mail.nl.linux.org/kernelnewbies/ FAQ: http://kernelnewbies.org/faq/
