Thread (138 messages) 138 messages, 5 authors, 2025-07-03

Re: [PATCH v1 23/29] mm/page-alloc: remove PageMappingFlags()

From: Lorenzo Stoakes <hidden>
Date: 2025-07-01 13:09:35
Also in: linux-doc, linux-fsdevel, linux-mm, lkml, virtualization

On Mon, Jun 30, 2025 at 03:00:04PM +0200, David Hildenbrand wrote:
We can now simply check for PageAnon() and remove PageMappingFlags().

... and while at it, use the folio instead and operate on
folio->mapping.
Probably worth mentioning to be super crystal clear that this is because
now it's either an anon folio or a KSM folio, both of which set the
FOLIO_MAPPING_ANON flag.

I wonder if there's other places that could be fixed up similarly that do
folio_test_anon() || folio_test_ksm() or equivalent?
Reviewed-by: Zi Yan <ziy@nvidia.com>
Signed-off-by: David Hildenbrand <redacted>
LGTM, so:

Reviewed-by: Lorenzo Stoakes <redacted>

quoted hunk ↗ jump to hunk
---
 include/linux/page-flags.h | 5 -----
 mm/page_alloc.c            | 7 +++----
 2 files changed, 3 insertions(+), 9 deletions(-)
diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h
index abed972e902e1..f539bd5e14200 100644
--- a/include/linux/page-flags.h
+++ b/include/linux/page-flags.h
@@ -723,11 +723,6 @@ static __always_inline bool folio_mapping_flags(const struct folio *folio)
 	return ((unsigned long)folio->mapping & PAGE_MAPPING_FLAGS) != 0;
 }

-static __always_inline bool PageMappingFlags(const struct page *page)
-{
-	return ((unsigned long)page->mapping & PAGE_MAPPING_FLAGS) != 0;
-}
-
 static __always_inline bool folio_test_anon(const struct folio *folio)
 {
 	return ((unsigned long)folio->mapping & PAGE_MAPPING_ANON) != 0;
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index a134b9fa9520e..a0ebcc5f54bb2 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -1375,10 +1375,9 @@ __always_inline bool free_pages_prepare(struct page *page,
 			(page + i)->flags &= ~PAGE_FLAGS_CHECK_AT_PREP;
 		}
 	}
-	if (PageMappingFlags(page)) {
-		if (PageAnon(page))
-			mod_mthp_stat(order, MTHP_STAT_NR_ANON, -1);
-		page->mapping = NULL;
+	if (folio_test_anon(folio)) {
+		mod_mthp_stat(order, MTHP_STAT_NR_ANON, -1);
+		folio->mapping = NULL;
 	}
 	if (unlikely(page_has_type(page)))
 		page->page_type = UINT_MAX;
--
2.49.0
  
Keyboard shortcuts
hback out one level
jnext message in thread
kprevious message in thread
ldrill in
Escclose help / fold thread tree
?toggle this help