• Andi Kleen's avatar
    x86: don't use large pages to map the first 2/4MB of memory · f5c24a7f
    Andi Kleen authored
    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: default avatarAndi Kleen <ak@suse.de>
    Acked-by: andreas.herrmann3@amd.com
    Cc: mingo@elte.hu
    Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
    Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
    f5c24a7f
bugs_64.c 778 Bytes