From: Vernon Yang <yanglincheng@kylinos.cn>
Date: Sat, 21 Feb 2026 09:39:17 +0000 (+0800)
Subject: mm: add folio_test_lazyfree helper
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=6cc153f90b7cf07db2b49469dfd79141b145036a;p=thirdparty%2Fkernel%2Flinux.git

mm: add folio_test_lazyfree helper

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

Link: https://lkml.kernel.org/r/20260221093918.1456187-4-vernon2gm@gmail.com
Signed-off-by: Vernon Yang <yanglincheng@kylinos.cn>
Acked-by: David Hildenbrand (Red Hat) <david@kernel.org>
Reviewed-by: Lance Yang <lance.yang@linux.dev>
Reviewed-by: Dev Jain <dev.jain@arm.com>
Reviewed-by: Barry Song <baohua@kernel.org>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Liam Howlett <Liam.Howlett@oracle.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Nico Pache <npache@redhat.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h
index f7a0e4af0c734..415e9f2ef616b 100644
--- a/include/linux/page-flags.h
+++ b/include/linux/page-flags.h
@@ -724,6 +724,11 @@ static __always_inline bool folio_test_anon(const struct folio *folio)
 	return ((unsigned long)folio->mapping & FOLIO_MAPPING_ANON) != 0;
 }
 
+static __always_inline bool folio_test_lazyfree(const struct folio *folio)
+{
+	return folio_test_anon(folio) && !folio_test_swapbacked(folio);
+}
+
 static __always_inline bool PageAnonNotKsm(const struct page *page)
 {
 	unsigned long flags = (unsigned long)page_folio(page)->mapping;
diff --git a/mm/rmap.c b/mm/rmap.c
index 8f08090d7eb9f..5fd22ba59d355 100644
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -2060,7 +2060,7 @@ 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_test_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 031c5c035a828..d531040a3593c 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -963,8 +963,7 @@ 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_test_lazyfree(folio)) {
 		*dirty = false;
 		*writeback = false;
 		return;
@@ -1508,7 +1507,7 @@ retry:
 			}
 		}
 
-		if (folio_test_anon(folio) && !folio_test_swapbacked(folio)) {
+		if (folio_test_lazyfree(folio)) {
 			/* follow __remove_mapping for reference */
 			if (!folio_ref_freeze(folio, 1))
 				goto keep_locked;