Thank you Prabhu. Now I can proceed... :-) On Thu, Sep 30, 2010 at 11:09 PM, Prabhu nath <[email protected]> wrote:
> "page", I believe, you are refering to struct page. > > kmap is a kernel function which takes in the parameter struct page pointer > and returns kernel virtual address. > On a typical x86 machine with 1GB RAM, kmap works like this. > If the struct page is associated with the physical page less than 896 MB, > then kmap simply adds the PAGE_OFFSET - 0xC0000000 to the physical address > (VA = PA + PAGE_OFFSET) and returns , because in a typcial 3G/1G partition > of the linear virtual address space, first 896MB of the kernel virtual > address is directly mapped to the physical address. I > If the struct page is associated with physical page in the HIGHMEM region > i.e. > 896 MB, then it will map this physical page to the kernel virtual > address, generally named vmalloc address region or non-contiguous address > region and then returns this virtual address > > Regards, > Prabhu > > > > > > > On Fri, Oct 1, 2010 at 11:22 AM, Sengottuvelan S < > [email protected]> wrote: > >> Hi >> >> I am new to this forum. I have specific quesion on "kmap" and "page". I >> would like to know how these two are related to eachother. >> >> Thanks in advance. >> >> > -- Regards, S. Sengottuvelan.
