Re: [PATCH] x86/mm/init: respect memblock reserved regions when destroying mappings

["H. Peter Anvin" <hpa@zytor.com>]

On 02/10/2011 03:57 PM, Yinghai Lu wrote:
> On 02/10/2011 03:48 PM, Jeremy Fitzhardinge wrote:
>> On 02/08/2011 11:34 AM, H. Peter Anvin wrote:
>>> On 02/07/2011 07:12 PM, Yinghai Lu wrote:
>>>> why punishing native path with those checking?
>>>>
>>> What happens if you end up with a reserved range in an unfortunate place
>>> on real hardware?
>>
>> Yes, exactly.  The reserved region code isn't very useful if you can't
>> rely on it to reserve stuff.
> 
> assume context is under:
> moving cleanup_highmap() down after brk is concluded, and check memblock_reserved there.
> 
> one case for that: native path, bootloader could put initrd under 512M. and it is with memblock reserved.
> if we check those range with memblock_reserved, initial kernel mapping will not be cleaned up.
> 
> or worse if we are checking if there is any range from __pa(_brk_end) to 512M is with memblock reserved to decide
> if we need to clean-up highmap. it will skip for whole range.
> 

I'm afraid I simply can't parse the above.

	-hpa