Re: [PATCH] memory hotadd fixes [4/5] avoid check in acpi

["Mika Penttilä" <mika.penttila@kolumbus.fi>]

keith mannthey wrote:
> On Fri, 2006-08-04 at 12:48 +0900, KAMEZAWA Hiroyuki wrote:
>   
>> On Thu, 03 Aug 2006 20:23:46 -0700
>> keith mannthey <kmannth@us.ibm.com> wrote:
>>     
>
>   
>>>>> What keeps 0xa0000000 to 0xa1000000 from being re-onlined by a bad call
>>>>> to add_memory?
>>>>>           
>>>> Usual sparsemem's add_memory() checks whether there are sections in
>>>> sparse_add_one_section(). then add_pages() returns -EEXIST (nothing to do).
>>>> And ioresouce collision check will finally find collision because 0-0xbffffff
>>>> resource will conflict with 0xa0000000 to 0xa10000000 area.
>>>> But, x86_64 's (not sparsemem) add_pages() doen't do collision check, so it panics.
>>>>         
>>> I have paniced with your 5 patches while doing SPARSMEM....  I think
>>> your 6th patch address the issues I was seeing.  
>>>
>>>       
>
>
> with the 6 patches things work as expected.  It is nice to have the
> sysfs devices online the correct amount of memory.  
>
> I was broken without this patch because invalid add_memory calls are
> made on by box (yet another issue) during boot. 
>
> I will build my patch set on top of your 6 patches. 
>
> Thanks,
>   Keith 
>
>   
Keith, are you working on the reserve hotadd case? It looks really 
broken, at the same time we both assume the hot add region contains RAM 
per e820 (use of reserve_bootmem_node()) and at the same time in other 
places (in reserve_hotadd()) that it may not contain RAM. And 
nodes_cover_memory() is broken no matter what we assume.


--Mika