On Fri 26-03-21 09:55:03, Oscar Salvador wrote:

On Fri, Mar 26, 2021 at 09:35:03AM +0100, Michal Hocko wrote:

[...]

quoted

Yes this is much better! Just a minor suggestion would be to push
memory_block all the way to memory_block_online (it oline a memory
block). I would also slightly prefer to provide 2 helpers that would make
it clear that this is to reserve/cleanup the vmemamp space (defined in
the memory_hotplug proper).

Glad to hear that!
By pushing memory_block all the way to memory_block_{online,offline}, you
mean passing the memblock struct together with nr_vmemmap_pages,
only_type and nid to memory_block_{offline,online}, and derive in there
the start_pfn and nr_pages?

memory_block + online_type should be sufficient.
-- 
Michal Hocko
SUSE Labs