[PATCH v5 09/10] x86: Pass memory range via E820 for kdump

[H. Peter Anvin]

On 04/10/2014 07:47 PM, Dave Young wrote:
> On 04/10/14 at 07:36pm, H. Peter Anvin wrote:
>> On 04/10/2014 07:28 PM, Dave Young wrote:
>>>>  
>>>> +static void add_e820_map_from_mr(struct x86_linux_param_header *real_mode,
>>>> +			struct e820entry *e820, struct memory_range *range, int nr_range)
>>>> +{
>>>> +	int i;
>>>> +
>>>> +	for (i = 0; i < nr_range; i++) {
>>>> +		e820[i].addr = range[i].start;
>>>> +		e820[i].size = range[i].end - range[i].start;
>>>
>>> I see it's same as original code but I still feel it should be end - start + 1;
>>>
>>
>> I can't see how it could possibly be +1.
>>
>> How do you encode range[].end?  If it is inclusive it should be end -
>> start - 1, if it is a semiclosed range (the normal thing in computer
>> contexts) then the code above is correct.

I obviously got the above backwards in my head.  Please ignore.

> 
> Say the first range from my /proc/iomem:
> 00000000-00000fff : reserved
> 
> Shouldn't the size be 0x1000? It looks like closed range instead of semiclosed range.

You're right.  I thought we mangled the contents for /proc/iomem, but we
actually keep the contents as a closed range.

So never mind me!  -ENOBRAINTODAY.

	-hpa