linux-kernel - [PATCH mm-new v4 4/6] mm: add folio_is

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Message-ID: <20260111121909.8410-5-yanglincheng@kylinos.cn>
Date: Sun, 11 Jan 2026 20:19:07 +0800
From: Vernon Yang <vernon2gm@...il.com>
To: akpm@...ux-foundation.org,
	david@...nel.org
Cc: lorenzo.stoakes@...cle.com,
	ziy@...dia.com,
	dev.jain@....com,
	baohua@...nel.org,
	lance.yang@...ux.dev,
	linux-mm@...ck.org,
	linux-kernel@...r.kernel.org,
	Vernon Yang <yanglincheng@...inos.cn>
Subject: [PATCH mm-new v4 4/6] mm: add folio_is_lazyfree helper

Add folio_is_lazyfree() function to identify lazy-free folios to improve
code readability.

Signed-off-by: Vernon Yang <yanglincheng@...inos.cn>
---
 include/linux/mm_inline.h | 5 +++++
 mm/rmap.c                 | 2 +-
 mm/vmscan.c               | 5 ++---
 3 files changed, 8 insertions(+), 4 deletions(-)

diff --git a/include/linux/mm_inline.h b/include/linux/mm_inline.h
index fa2d6ba811b5..65a4ae52d915 100644
--- a/include/linux/mm_inline.h
+++ b/include/linux/mm_inline.h
@@ -35,6 +35,11 @@ static inline int page_is_file_lru(struct page *page)
 	return folio_is_file_lru(page_folio(page));
 }
 
+static inline int folio_is_lazyfree(const struct folio *folio)
+{
+	return folio_test_anon(folio) && !folio_test_swapbacked(folio);
+}
+
 static __always_inline void __update_lru_size(struct lruvec *lruvec,
 				enum lru_list lru, enum zone_type zid,
 				long nr_pages)
diff --git a/mm/rmap.c b/mm/rmap.c
index 336b27e00238..fd335b171ea7 100644
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -2042,7 +2042,7 @@ static bool try_to_unmap_one(struct folio *folio, struct vm_area_struct *vma,
 		}
 
 		if (!pvmw.pte) {
-			if (folio_test_anon(folio) && !folio_test_swapbacked(folio)) {
+			if (folio_is_lazyfree(folio)) {
 				if (unmap_huge_pmd_locked(vma, pvmw.address, pvmw.pmd, folio))
 					goto walk_done;
 				/*
diff --git a/mm/vmscan.c b/mm/vmscan.c
index 81828fa625ed..ad3516ff1381 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -964,8 +964,7 @@ static void folio_check_dirty_writeback(struct folio *folio,
 	 * They could be mistakenly treated as file lru. So further anon
 	 * test is needed.
 	 */
-	if (!folio_is_file_lru(folio) ||
-	    (folio_test_anon(folio) && !folio_test_swapbacked(folio))) {
+	if (!folio_is_file_lru(folio) || folio_is_lazyfree(folio)) {
 		*dirty = false;
 		*writeback = false;
 		return;
@@ -1506,7 +1505,7 @@ static unsigned int shrink_folio_list(struct list_head *folio_list,
 			}
 		}
 
-		if (folio_test_anon(folio) && !folio_test_swapbacked(folio)) {
+		if (folio_is_lazyfree(folio)) {
 			/* follow __remove_mapping for reference */
 			if (!folio_ref_freeze(folio, 1))
 				goto keep_locked;
-- 
2.51.0