On 18 Jun 2025, at 13:39, David Hildenbrand wrote:
> Let's make it clearer that we are talking about movable_ops pages.
>
> Signed-off-by: David Hildenbrand <da...@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 204e89eac998f..c575778456f97 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_BUG_ON(!page_has_movable_ops(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..f8b7c09e2e48c 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 will grab the page lock. */
I feel that the removed comment should stay, since the current comment
makes no sense when I read it alone.
In addition, why is __PageMovable() is renamed to page_has_movable_ops() but
__SetPageMovable() stays the same? page_has_movable_ops() and __SetPageMovable()
are functions for checking and setting PAGE_MAPPING_MOVABLE. The naming just
does not look symmetric.
--
Best Regards,
Yan, Zi
