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

From: "David Hildenbrand (Arm)" <david@kernel.org>
To: Gregory Price <gourry@gourry.net>
Cc: linux-kernel@vger.kernel.org,
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Subject: Re: [PATCH 1/2] mm: remove CONFIG_ARCH_ENABLE_MEMORY_HOTREMOVE
Date: Thu, 19 Mar 2026 19:08:57 +0100	[thread overview]
Message-ID: <e166588e-036c-4fa3-81fc-d7aca9f02c29@kernel.org> (raw)
In-Reply-To: <abwVK8nLpSLVcT5G@gourry-fedora-PF4VCD3F>

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

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.

-- 
Cheers,

David