Re: [Patch 2/2]: powerpc/hotplug/mm: Fix hot-add memory node assoc

[Michael Bringmann <mwb@linux.vnet.ibm.com>]

On 05/25/2017 10:10 AM, Reza Arbab wrote:
> On Thu, May 25, 2017 at 04:19:53PM +1000, Michael Ellerman wrote:
>> The commit message for 3af229f2071f says:
>>
>>    In practice, we never see a system with 256 NUMA nodes, and in fact, we
>>    do not support node hotplug on power in the first place, so the nodes
>>    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
>>    that are online when we come up are the nodes that will be present for
>>    the lifetime of this kernel.
>>
>> Is that no longer true?
> 
> I don't know what the reasoning behind that statement was at the time, but as far as I can tell, the only thing missing for node hotplug now is Balbir's patchset [1]. He fixes the resource issue which motivated 3af229f2071f and reverts it.
> 
> With that set, I can instantiate a new numa node just by doing add_memory(nid, ...) where nid doesn't currently exist.
> 
> [1] https://lkml.kernel.org/r/1479253501-26261-1-git-send-email-bsingharora@gmail.com
> 

Yes, the change to 'numa.c' looks to be sufficient for my needs as well.

-- 
Michael W. Bringmann
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