Re: [PATCH 1/2] mm: remove CONFIG_ARCH_ENABLE_MEMORY_HOTREMOVE

Zi Yan
2026-03-19T18:13:12Z

On 19 Mar 2026, at 14:08, David Hildenbrand (Arm) wrote:

> On 3/19/26 16:24, Gregory Price wrote:
>> On Thu, Mar 19, 2026 at 09:19:40AM +0100, David Hildenbrand (Arm) wrote:
>>> All architectures that select CONFIG_ARCH_ENABLE_MEMORY_HOTREMOVE also
>>> select CONFIG_ARCH_ENABLE_MEMORY_HOTPLUG. So we can just remove
>>> CONFIG_ARCH_ENABLE_MEMORY_HOTREMOVE.
>>>
>>> For CONFIG_MIGRATION, make it depend on CONFIG_MEMORY_HOTREMOVE instead,
>>> and make CONFIG_MEMORY_HOTREMOVE select CONFIG_MIGRATION (just like
>>> CONFIG_CMA and CONFIG_COMPACTION already do).
>>>
>>> We'll clean up CONFIG_MIGRATION next.
>>>
>>> Signed-off-by: David Hildenbrand (Arm) <david@kernel.org>
>>
>> HOTREMOVE has long been a thorn in my side, I appreciate you cleaning
>> this up.
>
> On a long cardrive today I was wondering: do we still need a separate
> MEMORY_HOTREMOVE

You mean merge HOTREMOVE into HOTPLUG? I wondered the same. Is there
a reason to only have HOTPLUG without HOTREMOVE?

>
> Now we'll have
>
> config MEMORY_HOTREMOVE
> bool "Allow for memory hot remove"
> select HAVE_BOOTMEM_INFO_NODE if (X86_64 || PPC64)
> depends on MEMORY_HOTPLUG
> select MIGRATION
>
> I'll try to get rid of that HAVE_BOOTMEM_INFO_NODE shite next.
>
> Then it's really just MIGRATION and some sprinkled
> CONFIG_MEMORY_HOTREMOVE. Not a lot of code.

Best Regards,
Yan, Zi