linux-kernel - Re: [Patch 1/1] x86 efi: Fill all reserved memmap entries if add_efi

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Date:	Tue, 25 May 2010 15:46:08 -0700
From:	Mike Travis <travis@....com>
To:	"H. Peter Anvin" <hpa@...or.com>
CC:	Yinghai <yinghai.lu@...cle.com>, Ingo Molnar <mingo@...e.hu>,
	Thomas Gleixner <tglx@...utronix.de>, x86@...nel.org,
	Suresh Siddha <suresh.b.siddha@...el.com>,
	Rusty Russell <rusty@...tcorp.com.au>,
	Jens Axboe <jens.axboe@...cle.com>,
	Jack Steiner <steiner@....com>,
	LKML <linux-kernel@...r.kernel.org>, jkosina@...ell.com
Subject: Re: [Patch 1/1] x86 efi: Fill all reserved memmap entries if add_efi_memmap
 specified.



H. Peter Anvin wrote:
> On 05/25/2010 03:34 PM, Mike Travis wrote:
>>
>> H. Peter Anvin wrote:
>>> On 05/13/2010 02:55 PM, Mike Travis wrote:
>>>> I saw that too, and wondered why e820_saved did not
>>>> have the extra entries.   The comment indicates it
>>>> should.
>>>>
>>>> I'm on the system tonight and will investigate this
>>>> further.
>>>>
>>> e820_saved lacks the extra entries because they aren't being passed in
>>> from the bootloader, as they should, and instead you're using
>>> add_efi_memmap which is, as far as the kernel is concerned, a post-boot
>>> modification.
>>>
>>> That being said, add_efi_memmap does come from the firmware, and as such
>>> it would be legitimate for it to add them to e820_saved.
>>>
>>> 	-hpa
>> Did this last patch meet expectations?
>>
>> http://marc.info/?l=linux-kernel&m=127474230623061&w=4
>>
> 
> I'm concerned about calling sanitize_e820_map() on e820_saved; it is
> supposed to reflect the raw data as reported by the source, and
> sanitizing it would corrupt that.
> 
> 	-hpa

I wondered about that. Sanitize seems to remove adjacent
entries, etc. making the map smaller, but I couldn't detect
any real differences (though admittedly I didn't do a byte
by byte comparison.)

But I'll submit another with that call removed.

Thanks,
Mike
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