[lkml]   [2000]   [Aug]   [28]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
    SubjectRe: How does the kernel map physical to virtual addresses?

    On Mon, Aug 28, 2000 at 01:56:34PM +0100, Tigran Aivazian wrote:
    > it is interesting to observe that many questions that deal with _details_
    > are answered quickly but questions related to fundamental concepts related
    > to how Linux is designed, baffle all of us (since 0 people answered). So,
    > is there really nobody in the whole world who can answer this? I would
    > like to know the answer (about global kernel memory layout - i.e. what
    > goes into PSE pages and what goes into normal ones, and how does PAE mode
    > change the picture?) myself...

    If PSE is available, it is used to map the bits of the kernel's
    VA which permanently maps all of physical memory. As a result, those
    pages cannot necessarily be looked up via a normal page table walk.
    Anything dynamically mapped --- ie. high pages (if using PAE), or
    vmalloc/ioremap pages --- is mapped using normal 4k ptes.

    mem_map[] is completely unaffected by the use of PSE, and continues to
    keep one entry per 4k physical page regardless of how the page tables
    have been constructed.

    To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
    the body of a message to
    Please read the FAQ at

     \ /
      Last update: 2005-03-22 12:38    [W:0.029 / U:1.472 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site