Re: [PATCH v5 3/3] mm/page_alloc: Keep memoryless cpuless node 0 offline

From: David Hildenbrand
Date: Fri Aug 07 2020 - 02:58:39 EST


On 07.08.20 06:32, Andrew Morton wrote:
> On Fri, 3 Jul 2020 18:28:23 +0530 Srikar Dronamraju <srikar@xxxxxxxxxxxxxxxxxx> wrote:
>
>>> The memory hotplug changes that somehow because you can hotremove numa
>>> nodes and therefore make the nodemask sparse but that is not a common
>>> case. I am not sure what would happen if a completely new node was added
>>> and its corresponding node was already used by the renumbered one
>>> though. It would likely conflate the two I am afraid. But I am not sure
>>> this is really possible with x86 and a lack of a bug report would
>>> suggest that nobody is doing that at least.
>>>
>>
>> JFYI,
>> Satheesh copied in this mailchain had opened a bug a year on crash with vcpu
>> hotplug on memoryless node.
>>
>> https://bugzilla.kernel.org/show_bug.cgi?id=202187
>
> So... do we merge this patch or not? Seems that the overall view is
> "risky but nobody is likely to do anything better any time soon"?

I recall the issue Michal saw was "fix powerpc" vs. "break other
architectures". @Michal how should we proceed? At least x86-64 won't be
affected IIUC.

--
Thanks,

David / dhildenb