[PATCH] mm: Convert lru_add_page_tail() to lru_add_split_folio()

[PATCH] mm: Convert lru_add_page_tail() to lru_add_split_folio()

[Matthew Wilcox (Oracle)]

Remove three hidden calls to compound_head() and accesses to page->lru.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
---
 mm/huge_memory.c | 18 +++++++++---------
 1 file changed, 9 insertions(+), 9 deletions(-)

diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 514db6a5eee7..d8181a80c441 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -3262,25 +3262,25 @@ static void remap_page(struct folio *folio, unsigned long nr, int flags)
 	}
 }
 
-static void lru_add_page_tail(struct folio *folio, struct page *tail,
+static void lru_add_split_folio(struct folio *folio, struct folio *new_folio,
 		struct lruvec *lruvec, struct list_head *list)
 {
-	VM_BUG_ON_FOLIO(PageLRU(tail), folio);
+	VM_BUG_ON_FOLIO(folio_test_lru(new_folio), folio);
 	lockdep_assert_held(&lruvec->lru_lock);
 
 	if (list) {
 		/* page reclaim is reclaiming a huge page */
 		VM_WARN_ON(folio_test_lru(folio));
-		get_page(tail);
-		list_add_tail(&tail->lru, list);
+		folio_get(new_folio);
+		list_add_tail(&new_folio->lru, list);
 	} else {
 		/* head is still on lru (and we have it frozen) */
 		VM_WARN_ON(!folio_test_lru(folio));
 		if (folio_test_unevictable(folio))
-			tail->mlock_count = 0;
+			new_folio->mlock_count = 0;
 		else
-			list_add_tail(&tail->lru, &folio->lru);
-		SetPageLRU(tail);
+			list_add_tail(&new_folio->lru, &folio->lru);
+		folio_set_lru(new_folio);
 	}
 }
 
@@ -3573,8 +3573,8 @@ static int __split_unmapped_folio(struct folio *folio, int new_order,
 					((mapping || swap_cache) ?
 						folio_nr_pages(release) : 0));
 
-			lru_add_page_tail(origin_folio, &release->page,
-						lruvec, list);
+			lru_add_split_folio(origin_folio, release, lruvec,
+					list);
 
 			/* Some pages can be beyond EOF: drop them from cache */
 			if (release->index >= end) {
-- 
2.47.2

Re: [PATCH] mm: Convert lru_add_page_tail() to lru_add_split_folio()

[Zi Yan]

On 13 Mar 2025, at 11:14, Matthew Wilcox (Oracle) wrote:

> Remove three hidden calls to compound_head() and accesses to page->lru.
>
> Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
> ---
>  mm/huge_memory.c | 18 +++++++++---------
>  1 file changed, 9 insertions(+), 9 deletions(-)
>
LGTM. Reviewed-by: Zi Yan <ziy@nvidia.com>

Best Regards,
Yan, Zi