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    SubjectRe: [patch] cache pipe buf page address for non-highmem arch
    On Fri, Mar 23, 2007 at 10:14:52AM +0000, Christoph Hellwig wrote:
    > I think you're fixing the symptom here and not the cause. If calculating
    > the virtual address of a page is so expensive on your setup it should
    > define WANT_PAGE_VIRTUAL and we should always cache the virtual address
    > in struct page. There's a lot more code, epecially in filesystems that's
    > rather upset about a slow page_address.

    Andi shot that down when I brought it up a while ago, as it does show
    up in profiles for networking and other code paths. His argument is that
    the loss of memory is excessive. Personally, I think the benefits of a
    64 byte struct page on x86-64 outweigh the memory loss, as it means page
    index to address translations are a simple shift.

    "Time is of no importance, Mr. President, only life is important."
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