Re: [tip:x86/mm] x86: make e820_update_range() handle small range update

[Yinghai Lu <yinghai@kernel.org>]

Ingo Molnar wrote:
> * Yinghai Lu <yinghai@kernel.org> wrote:
> 
>> Commit-ID:  78a8b35bc7abf8b8333d6f625e08c0f7cc1c3742
>> Gitweb:     http://git.kernel.org/tip/78a8b35bc7abf8b8333d6f625e08c0f7cc1c3742
>> Author:     Yinghai Lu <yinghai@kernel.org>
>> AuthorDate: Thu, 12 Mar 2009 22:36:01 -0700
>> Commit:     Ingo Molnar <mingo@elte.hu>
>> CommitDate: Sat, 14 Mar 2009 12:20:07 +0100
>>
>> x86: make e820_update_range() handle small range update
>>
>> Impact: enhance e820 code to handle more cases
>>
>> Try to handle new range which could be covered by one entry.
>>
>> Signed-off-by: Yinghai Lu <yinghai@kernel.org>
>> Cc: jbeulich@novell.com
>> LKML-Reference: <49B9F0C1.10402@kernel.org>
>> Signed-off-by: Ingo Molnar <mingo@elte.hu>
> 
> -tip testing found a bootup crash + reboot due to this patch.
> 
> config attached. The bootup crashes here:
> 
> [    0.000000] MTRR variable ranges enabled:
> [    0.000000]   0 base 0000000000 mask FFC0000000 write-back
> [    0.000000]   1 disabled
> [    0.000000]   2 disabled
> [    0.000000]   3 disabled
> [    0.000000]   4 disabled
> [    0.000000]   5 disabled
> [    0.000000]   6 disabled
> [    0.000000]   7 disabled
> [    0.000000] x86 PAT enabled: cpu 0, old 0x7040600070406, new 0x7010600070106
> [    0.000000]   get_mtrr: cpu0 reg00 base=0000000000 size=0000040000 write-back
> [    reboot  ]
> 

what does the e820 map look like?

YH