Re: [PATCH 1/2] x86 e820: Check for exactmap appearance when parsing first memmap option

Yinghai Lu
2013-01-29T02:01:11Z

On Mon, Jan 28, 2013 at 5:09 PM, H. Peter Anvin <hpa@zytor.com> wrote:
> On 01/22/2013 07:20 AM, Thomas Renninger wrote:
>> From: Yinghai Lu <yinghai@kernel.org>
>>
>> memmap=exactmap will throw away all original, but also until then
>> user defined (through other provided memmap= parameters) areas.
>> That means all memmap= boot parameters passed before a memmap=exactmap
>> parameter are not recognized.
>> Without this fix:
>> memmap=x@y memmap=exactmap memmap=i#k
>> only i#k would get recognized.
>>
>> This is wrong, this fix will only throw away all original e820 areas once
>> when memmap=exactmap is found in the whole boot command line and before
>> any other memmap= option is parsed.
>>
>
> I don't understand why this is wrong. The kernel command line is always
> parsed from left to right, and I don't see anything inherently
> problematic with that with something like a big hammer like exactmap.

Ok, let's drop it.