Re: [PATCH V5 - Rebased] mm/hotplug: Reorder memblock_[free|remove]() calls in try_remove_memory()

From: David Hildenbrand
Date: Thu Jun 13 2019 - 12:49:42 EST

On 13.06.19 03:54, Andrew Morton wrote:
> On Wed, 12 Jun 2019 08:53:33 +0200 David Hildenbrand <david@xxxxxxxxxx> wrote:
>>>>> ...
>>>>> - Rebased on linux-next (next-20190611)
>>>> Yet the patch you've prepared is designed for 5.3. Was that
>>>> deliberate, or should we be targeting earlier kernels?
>>> It was deliberate for 5.3 as a preparation for upcoming reworked arm64 hot-remove.
>> We should probably add to the patch description something like "This is
>> a preparation for arm64 memory hotremove. The described issue is not
>> relevant on other architectures."
> Please. And is there any reason to merge it separately? Can it be
> [patch 1/3] in the "arm64/mm: Enable memory hot remove" series?

Nothing that the patch can be considered a cleanup:

mm/hotplug: Reorder memblock_[free|remove]() calls in try_remove_memory()

In add_memory_resource() we have:

memblock_add_node(start, size, nid)
arch_add_memory(nid, start, size, &restrictions);
create_memory_block_devices(start, size);

While in try_remove_memory() we have:

memblock_free(start, size);
memblock_remove(start, size);
remove_memory_block_devices(start, size);
arch_remove_memory(nid, start, size, NULL);

Let's restore the correct order by removing the memblock after

I think with such a description, we can include it now. Andrew?



David / dhildenb