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

[Dave Young]

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.

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.

Thanks
Dave