Re: [PATCH 2/2] mm/memory_hotplug: remove head page reference in scan_movable_pages()

[Matthew Wilcox]

On Mon, Jan 23, 2023 at 12:23:47PM -0800, Sidhartha Kumar wrote:
> -		if (!PageHuge(page))
> +		folio = page_folio(page);
> +		if (!folio_test_hugetlb(folio))
>  			continue;
> -		head = compound_head(page);
>  		/*
>  		 * This test is racy as we hold no reference or lock.  The
>  		 * hugetlb page could have been free'ed and head is no longer

Assuming the comment is correct, this patch is also unsafe.