Messages in this thread | | | Date | Sun, 13 Jul 2008 11:17:45 -0700 | From | "Yinghai Lu" <> | Subject | Re: [PATCh] x86: overmapped fix when 4K pages on tail - 64bit |
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On Sun, Jul 13, 2008 at 7:57 AM, Andi Kleen <andi@firstfloor.org> wrote: > Arjan van de Ven <arjan@infradead.org> writes: > >> On Wed, 9 Jul 2008 20:15:02 -0700 >> Yinghai Lu <yhlu.kernel@gmail.com> wrote: >> >>> >>> >>> fix phys_pmd_init to make sure not to return big value than end. >>> >>> also print out range split:1G/2M/4K >>> >>> Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com> >> >> >> Making an accurate mapping solves a lot of potentially nasty/tricky >> corner cases, so I like the approach > > It also means that e.g. on a 1GB system the direct mapping will > never use 1GB pages. > > And the CPU has to handle this anyways because all the old > kernels overmap and no x86 CPU can drop support for all old > kernels. > > In the end it means only large systems will benefit from 1GB > pages, which seems wrong to me.
with this patch, my 256g system still use gbpages for 1g-3g, 4g-256g
YH
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