Re: [PATCH v1 2/2] mm/memory_hotplug: remove -EBUSY handling from scan_movable_pages()

[David Hildenbrand <david@redhat.com>]

On 14.05.25 13:15, David Hildenbrand wrote:
> Now that we can reliably identify PageOffline() pages that allow for
> memory offlining in has_unmovable_pages(), start_isolate_page_range()
> will fail on PageOffline() pages that would prevent memory offlining, and
> we no longer have to detect them in scan_movable_pages() anymore.
> 
> Note that the previous mechanism relied on MEM_GOING_OFFLINE, whereby we
> were not able to distinguish the types of PageOffline() before
> MEM_GOING_OFFLINE.
> 
> Signed-off-by: David Hildenbrand <david@redhat.com>
> ---

Hmm, I'm having second thoughts about this patch.

With hyper-v, I think we can hotplug partial memory blocks (e.g., 64 
MiB) and online it to ZONE_MOVABLE. These blocks cannot get offlined so 
far -- in contrast to virtio-mem -- and has_unmovable_pages() would not 
identify that.

So probably best to keep that in for now.

-- 
Cheers,

David / dhildenb