Messages in this thread | | | Date | Wed, 02 Feb 2011 21:05:06 -0800 | From | "H. Peter Anvin" <> | Subject | Re: [PATCH] x86/mm/init: respect memblock reserved regions when destroying mappings |
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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.
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