lkml.org 
[lkml]   [2011]   [Feb]   [3]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: [PATCH] x86/mm/init: respect memblock reserved regions when destroying mappings
    On 01/31/2011 07:18 AM, Stefano Stabellini wrote:
    > x86/mm/init: respect memblock reserved regions when destroying mappings
    >
    > In init_memory_mapping we are destroying all the mappings between
    > _brk_end and _end, no matter if some memory areas in that range have
    > been reserved using memblock_x86_reserve_range.
    > Besides if _end is not pmd aligned we might destroy the
    > mappings for valid memory between _end and the following pmd.
    >
    > In order to avoid this problem, before clearing any pmds we check if the
    > corresponding memory area has been reserved and we only destroy the
    > mapping if it hasn't.
    >
    > We found this problem because under Xen we have a valid mapping at _end,
    > and if _end is not pmd aligned the current code destroys the initial
    > part of it.
    >
    > In practice this fix does not have any impact on native.
    >
    > Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>

    How on Earth would you end up with a reserved region *inside the BRK*?

    -hpa

    --
    H. Peter Anvin, Intel Open Source Technology Center
    I work for Intel. I don't speak on their behalf.



    \
     
     \ /
      Last update: 2011-02-03 06:07    [W:3.573 / U:0.016 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site