> -----Original Message-----
> From: David Hildenbrand <david@xxxxxxxxxx>
> Sent: Tuesday, May 25, 2021 2:12 PM
> I assume the following will work:
>
> diff --git a/drivers/base/memory.c b/drivers/base/memory.c
> index b31b3af5c490..6e661d106e96 100644
> --- a/drivers/base/memory.c
> +++ b/drivers/base/memory.c
> @@ -218,14 +218,15 @@ static int memory_block_offline(struct memory_block *mem)
> struct zone *zone;
> int ret;
>
> - zone = page_zone(pfn_to_page(start_pfn));
> -
> /*
> * Unaccount before offlining, such that unpopulated zone and kthreads
> * can properly be torn down in offline_pages().
> */
> - if (nr_vmemmap_pages)
> + if (nr_vmemmap_pages) {
> + /* Hotplugged memory has no holes. */
> + zone = page_zone(pfn_to_page(start_pfn));
> adjust_present_page_count(zone, -nr_vmemmap_pages);
> + }
>
> ret = offline_pages(start_pfn + nr_vmemmap_pages,
> nr_pages - nr_vmemmap_pages);
>
>
> We must not touch pfn_to_page(start_pfn) if it might be a memory hole.
> offline_pages() will make sure there are no holes, but that's too late.
Good catch, David. This patch works well.
