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    SubjectRe: [PATCH] [4/7] Don't use large pages to map the first 2/4MB of memory
    Andi Kleen a écrit :
    > Intel recommends to not use large pages for the first 1MB
    > of the physical memory because there are fixed size MTRRs there
    > which cause splitups in the TLBs.
    > On AMD doing so is also a good idea.
    > The implementation is a little different between 32bit and 64bit.
    > On 32bit I just taught the initial page table set up about this
    > because it was very simple to do. This also has the advantage
    > that the risk of a prefetch ever seeing the page even
    > if it only exists for a short time is minimized.
    > On 64bit that is not quite possible, so use set_memory_4k() a little
    > later (in check_bugs) instead.
    > Signed-off-by: Andi Kleen <>
    > ---
    > arch/x86/kernel/bugs_64.c | 12 ++++++++++++
    > arch/x86/mm/init_32.c | 6 +++++-
    > 2 files changed, 17 insertions(+), 1 deletion(-)

    Should we then change CONFIG_PHYSICAL_START from 0x100000 to 0x400000 ?

    Thank you
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      Last update: 2008-03-12 06:41    [W:0.024 / U:12.044 seconds]
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