[PATCH v1 16/29] mm: rename __PageMovable() to page_has_movable_ops()

David Hildenbrand
2025-06-30T13:01:05Z

Let's make it clearer that we are talking about movable_ops pages.

While at it, convert a VM_BUG_ON to a VM_WARN_ON_ONCE_PAGE.

Reviewed-by: Zi Yan <ziy@nvidia.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
---
include/linux/migrate.h | 2 +-
include/linux/page-flags.h | 2 +-
mm/compaction.c | 7 ++-----
mm/memory-failure.c | 4 ++--
mm/memory_hotplug.c | 8 +++-----
mm/migrate.c | 8 ++++----
mm/page_alloc.c | 2 +-
mm/page_isolation.c | 10 +++++-----
8 files changed, 19 insertions(+), 24 deletions(-)

diff --git a/include/linux/migrate.h b/include/linux/migrate.h
index 25659a685e2aa..e04035f70e36f 100644
--- a/include/linux/migrate.h
+++ b/include/linux/migrate.h
@@ -115,7 +115,7 @@ static inline void __SetPageMovable(struct page *page,
static inline
const struct movable_operations *page_movable_ops(struct page *page)
{
- VM_BUG_ON(!__PageMovable(page));
+ VM_WARN_ON_ONCE_PAGE(!page_has_movable_ops(page), page);

return (const struct movable_operations *)
((unsigned long)page->mapping - PAGE_MAPPING_MOVABLE);
diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h
index 4fe5ee67535b2..c67163b73c5ec 100644
--- a/include/linux/page-flags.h
+++ b/include/linux/page-flags.h
@@ -750,7 +750,7 @@ static __always_inline bool __folio_test_movable(const struct folio *folio)
PAGE_MAPPING_MOVABLE;
}

-static __always_inline bool __PageMovable(const struct page *page)
+static __always_inline bool page_has_movable_ops(const struct page *page)
{
return ((unsigned long)page->mapping & PAGE_MAPPING_FLAGS) ==
PAGE_MAPPING_MOVABLE;
diff --git a/mm/compaction.c b/mm/compaction.c
index 5c37373017014..41fd6a1fe9a33 100644
--- a/mm/compaction.c
+++ b/mm/compaction.c
@@ -1056,11 +1056,8 @@ isolate_migratepages_block(struct compact_control *cc, unsigned long low_pfn,
* Skip any other type of page
*/
if (!PageLRU(page)) {
- /*
- * __PageMovable can return false positive so we need
- * to verify it under page_lock.
- */
- if (unlikely(__PageMovable(page)) &&
+ /* Isolation code will deal with any races. */
+ if (unlikely(page_has_movable_ops(page)) &&
!PageIsolated(page)) {
if (locked) {
unlock_page_lruvec_irqrestore(locked, flags);
diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index b91a33fb6c694..9e2cff1999347 100644
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -1388,8 +1388,8 @@ static inline bool HWPoisonHandlable(struct page *page, unsigned long flags)
if (PageSlab(page))
return false;

- /* Soft offline could migrate non-LRU movable pages */
- if ((flags & MF_SOFT_OFFLINE) && __PageMovable(page))
+ /* Soft offline could migrate movable_ops pages */
+ if ((flags & MF_SOFT_OFFLINE) && page_has_movable_ops(page))
return true;

return PageLRU(page) || is_free_buddy_page(page);
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index 62d45752f9f44..5fad126949d08 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -1739,8 +1739,8 @@ bool mhp_range_allowed(u64 start, u64 size, bool need_mapping)

#ifdef CONFIG_MEMORY_HOTREMOVE
/*
- * Scan pfn range [start,end) to find movable/migratable pages (LRU pages,
- * non-lru movable pages and hugepages). Will skip over most unmovable
+ * Scan pfn range [start,end) to find movable/migratable pages (LRU and
+ * hugetlb folio, movable_ops pages). Will skip over most unmovable
* pages (esp., pages that can be skipped when offlining), but bail out on
* definitely unmovable pages.
*
@@ -1759,9 +1759,7 @@ static int scan_movable_pages(unsigned long start, unsigned long end,
struct folio *folio;

page = pfn_to_page(pfn);
- if (PageLRU(page))
- goto found;
- if (__PageMovable(page))
+ if (PageLRU(page) || page_has_movable_ops(page))
goto found;

/*
diff --git a/mm/migrate.c b/mm/migrate.c
index 040484230aebc..587af35b7390d 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -94,7 +94,7 @@ bool isolate_movable_ops_page(struct page *page, isolate_mode_t mode)
* Note that once a page has movable_ops, it will stay that way
* until the page was freed.
*/
- if (unlikely(!__PageMovable(page)))
+ if (unlikely(!page_has_movable_ops(page)))
goto out_putfolio;

/*
@@ -111,7 +111,7 @@ bool isolate_movable_ops_page(struct page *page, isolate_mode_t mode)
if (unlikely(!folio_trylock(folio)))
goto out_putfolio;

- VM_WARN_ON_ONCE_PAGE(!__PageMovable(page), page);
+ VM_WARN_ON_ONCE_PAGE(!page_has_movable_ops(page), page);
if (PageIsolated(page))
goto out_no_isolated;

@@ -153,7 +153,7 @@ static void putback_movable_ops_page(struct page *page)
*/
struct folio *folio = page_folio(page);

- VM_WARN_ON_ONCE_PAGE(!__PageMovable(page), page);
+ VM_WARN_ON_ONCE_PAGE(!page_has_movable_ops(page), page);
VM_WARN_ON_ONCE_PAGE(!PageIsolated(page), page);
folio_lock(folio);
page_movable_ops(page)->putback_page(page);
@@ -192,7 +192,7 @@ static int migrate_movable_ops_page(struct page *dst, struct page *src,
{
int rc = MIGRATEPAGE_SUCCESS;

- VM_WARN_ON_ONCE_PAGE(!__PageMovable(src), src);
+ VM_WARN_ON_ONCE_PAGE(!page_has_movable_ops(src), src);
VM_WARN_ON_ONCE_PAGE(!PageIsolated(src), src);
rc = page_movable_ops(src)->migrate_page(dst, src, mode);
if (rc == MIGRATEPAGE_SUCCESS)
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 44e56d31cfeb1..a134b9fa9520e 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -2005,7 +2005,7 @@ static bool prep_move_freepages_block(struct zone *zone, struct page *page,
* migration are movable. But we don't actually try
* isolating, as that would be expensive.
*/
- if (PageLRU(page) || __PageMovable(page))
+ if (PageLRU(page) || page_has_movable_ops(page))
(*num_movable)++;
pfn++;
}
diff --git a/mm/page_isolation.c b/mm/page_isolation.c
index ece3bfc56bcd5..b97b965b3ed01 100644
--- a/mm/page_isolation.c
+++ b/mm/page_isolation.c
@@ -21,9 +21,9 @@
* consequently belong to a single zone.
*
* PageLRU check without isolation or lru_lock could race so that
- * MIGRATE_MOVABLE block might include unmovable pages. And __PageMovable
- * check without lock_page also may miss some movable non-lru pages at
- * race condition. So you can't expect this function should be exact.
+ * MIGRATE_MOVABLE block might include unmovable pages. Similarly, pages
+ * with movable_ops can only be identified some time after they were
+ * allocated. So you can't expect this function should be exact.
*
* Returns a page without holding a reference. If the caller wants to
* dereference that page (e.g., dumping), it has to make sure that it
@@ -133,7 +133,7 @@ static struct page *has_unmovable_pages(unsigned long start_pfn, unsigned long e
if ((mode == PB_ISOLATE_MODE_MEM_OFFLINE) && PageOffline(page))
continue;

- if (__PageMovable(page) || PageLRU(page))
+ if (PageLRU(page) || page_has_movable_ops(page))
continue;

/*
@@ -421,7 +421,7 @@ static int isolate_single_pageblock(unsigned long boundary_pfn,
* proper free and split handling for them.
*/
VM_WARN_ON_ONCE_PAGE(PageLRU(page), page);
- VM_WARN_ON_ONCE_PAGE(__PageMovable(page), page);
+ VM_WARN_ON_ONCE_PAGE(page_has_movable_ops(page), page);

goto failed;
}
--
2.49.0