Messages in this thread | | | Date | Wed, 12 Mar 2008 06:38:58 +0100 | From | Eric Dumazet <> | Subject | Re: [PATCH] [4/7] Don't use large pages to map the first 2/4MB of memory |
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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 <ak@suse.de> > > --- > 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 ?
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