Re: [PATCH 2/8] mm/bootmem_info: drop initialization of page->lru

On Mon, May 11, 2026 at 04:05:30PM +0200, David Hildenbrand (Arm) wrote:
>In the past, we used to store the type in page->lru.next, introduced by
>commit 5f24ce5fd34c ("thp: remove PG_buddy"). The location changed over
>the years; ever since commit 0386aaa6e9c8 ("bootmem: stop using
>page->index"), we store it alongside the info in page->private.
>
>Consequently, there is no need to reset page->lru anymore.
>
>Signed-off-by: David Hildenbrand (Arm) <[email protected]>
>---
> mm/bootmem_info.c | 1 -
> 1 file changed, 1 deletion(-)
>
>diff --git a/mm/bootmem_info.c b/mm/bootmem_info.c
>index 3d7675a3ae04..a0a1ecdec8d0 100644
>--- a/mm/bootmem_info.c
>+++ b/mm/bootmem_info.c
>@@ -34,7 +34,6 @@ void put_page_bootmem(struct page *page)
> 	if (page_ref_dec_return(page) == 1) {
> 		ClearPagePrivate(page);
> 		set_page_private(page, 0);
>-		INIT_LIST_HEAD(&page->lru);

Yep, that old INIT_LIST_HEAD() call was dead cleanup. page->lru and
page->buddy_list are in the same union:

			union {
				struct list_head lru;

				/* Or, free page */
				struct list_head buddy_list;
			};

and free_reserved_page() passes the page to the buddy allocator. The
later buddy list insertion will overwrite the values written by
INIT_LIST_HEAD(&page->lru) anyway.

> 		kmemleak_free_part_phys(PFN_PHYS(page_to_pfn(page)), PAGE_SIZE);
> 		free_reserved_page(page);
> 	}

LGTM, feel free to add:
Reviewed-by: Lance Yang <[email protected]>