Re: [PATCH] SPARSEMEM + NUMA can't handle unaligned memory regions?

[Andy Whitcroft <apw@shadowen.org>]

Michael Ellerman wrote:
> On Tue, 2006-05-09 at 09:32 +0100, Andy Whitcroft wrote:
> 
>>Michael Ellerman wrote:
>>
>>>I can't believe I'm the first person to see this, so I imagine I'm missing
>>>something. Perhaps it's only an issue on powerpc?
>>>
>>>I have a machine with some memory at 0, then a hole, and then some more memory
>>>which doesn't start on a section boundary. This is causing the following
>>>crash:
>>>
>>>add_region nid 1 start_pfn 0x77c0 pages 0x840
>>>add_region nid 1 start_pfn 0x0 pages 0x6000
>>
>>Nasty, could you send me your full boot log and your config and I'll
>>have a look at it.  I can say this code has been booted on a lot of
>>power boxes and I've never seen that before!  :)
> 
> 
> Ah yeah, I seem to have neglected to mention it's a kdump boot :} Sorry.
> That's why we get the strangely aligned memory sections. The section
> starting at 0 is for the kdump kernel, the bit at 0x77c0 covers some
> firmware that's allocated there by the first kernel.
> 
> I can still give you a .config and log if you want it, but not 'til
> tomorrow morning.

Heh.  Well at least that makes more sense.  It would be good to have
them generally.  But no I'm not scared of where this odd alignment is
coming from I can look at what we can do about it.

Thanks.

-apw