6.6-stable review patch. If anyone has any objections, please let me know.
------------------
From: Kefeng Wang <wangkefeng.wang@xxxxxxxxxx>
commit 593a10dabe08dcf93259fce2badd8dc2528859a8 upstream.
Folios of order <= 1 are not in deferred list, the check of order is added
into folio_undo_large_rmappable() from commit 8897277acfef ("mm: support
order-1 folios in the page cache"), but there is a repeated check for
small folio (order 0) during each call of the
folio_undo_large_rmappable(), so only keep folio_order() check inside the
function.
In addition, move all the checks into header file to save a function call
for non-large-rmappable or empty deferred_list folio.
Link: https://lkml.kernel.org/r/20240521130315.46072-1-wangkefeng.wang@xxxxxxxxxx
Signed-off-by: Kefeng Wang <wangkefeng.wang@xxxxxxxxxx>
Reviewed-by: David Hildenbrand <david@xxxxxxxxxx>
Reviewed-by: Vishal Moola (Oracle) <vishal.moola@xxxxxxxxx>
Cc: Johannes Weiner <hannes@xxxxxxxxxxx>
Cc: Lance Yang <ioworker0@xxxxxxxxx>
Cc: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxxxxx>
Cc: Muchun Song <muchun.song@xxxxxxxxx>
Cc: Roman Gushchin <roman.gushchin@xxxxxxxxx>
Cc: Shakeel Butt <shakeel.butt@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
[ Upstream commit itself does not apply cleanly, because there
are fewer calls to folio_undo_large_rmappable() in this tree. ]
Signed-off-by: Hugh Dickins <hughd@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
mm/huge_memory.c | 13 +------------
mm/internal.h | 17 ++++++++++++++++-
mm/page_alloc.c | 4 +---
3 files changed, 18 insertions(+), 16 deletions(-)
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -2767,22 +2767,11 @@ out:
return ret;
}
-void folio_undo_large_rmappable(struct folio *folio)
+void __folio_undo_large_rmappable(struct folio *folio)
{
struct deferred_split *ds_queue;
unsigned long flags;
- if (folio_order(folio) <= 1)
- return;
-
- /*
- * At this point, there is no one trying to add the folio to
- * deferred_list. If folio is not in deferred_list, it's safe
- * to check without acquiring the split_queue_lock.
- */
- if (data_race(list_empty(&folio->_deferred_list)))
- return;
-
ds_queue = get_deferred_split_queue(folio);
spin_lock_irqsave(&ds_queue->split_queue_lock, flags);
if (!list_empty(&folio->_deferred_list)) {
--- a/mm/internal.h
+++ b/mm/internal.h
@@ -413,7 +413,22 @@ static inline void folio_set_order(struc
#endif
}
-void folio_undo_large_rmappable(struct folio *folio);
+void __folio_undo_large_rmappable(struct folio *folio);
+static inline void folio_undo_large_rmappable(struct folio *folio)
+{
+ if (folio_order(folio) <= 1 || !folio_test_large_rmappable(folio))
+ return;
+
+ /*
+ * At this point, there is no one trying to add the folio to
+ * deferred_list. If folio is not in deferred_list, it's safe
+ * to check without acquiring the split_queue_lock.
+ */
+ if (data_race(list_empty(&folio->_deferred_list)))
+ return;
+
+ __folio_undo_large_rmappable(folio);
+}
static inline struct folio *page_rmappable_folio(struct page *page)
{
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -600,9 +600,7 @@ void destroy_large_folio(struct folio *f
return;
}
- if (folio_test_large_rmappable(folio))
- folio_undo_large_rmappable(folio);
-
+ folio_undo_large_rmappable(folio);
mem_cgroup_uncharge(folio);
free_the_page(&folio->page, folio_order(folio));
}
