On 04.11.24 22:05, Matthew Wilcox (Oracle) wrote:
The last argument to split_page_memcg() is now always 0, so remove it,
effectively reverting commit b8791381d7ed.
Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
---
include/linux/memcontrol.h | 4 ++--
mm/memcontrol.c | 26 ++++++++++++++------------
mm/page_alloc.c | 4 ++--
3 files changed, 18 insertions(+), 16 deletions(-)
diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
index 5502aa8e138e..a787080f814f 100644
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h
@@ -1044,7 +1044,7 @@ static inline void memcg_memory_event_mm(struct mm_struct *mm,
rcu_read_unlock();
}
-void split_page_memcg(struct page *head, int old_order, int new_order);
+void split_page_memcg(struct page *first, int order);
#else /* CONFIG_MEMCG */
@@ -1463,7 +1463,7 @@ void count_memcg_event_mm(struct mm_struct *mm, enum vm_event_item idx)
{
}
-static inline void split_page_memcg(struct page *head, int old_order, int new_order)
+static inline void split_page_memcg(struct page *first, int order)
{
}
#endif /* CONFIG_MEMCG */
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 5e44d6e7591e..506439a5dcfe 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -3034,25 +3034,27 @@ void __memcg_slab_free_hook(struct kmem_cache *s, struct slab *slab,
}
/*
- * Because folio_memcg(head) is not set on tails, set it now.
+ * The memcg data is only set on the first page, now transfer it to all the
+ * other pages.
*/
-void split_page_memcg(struct page *head, int old_order, int new_order)
+void split_page_memcg(struct page *first, int order)
{
- struct folio *folio = page_folio(head);
+ unsigned long memcg_data = first->memcg_data;
+ struct obj_cgroup *objcg;
int i;
- unsigned int old_nr = 1 << old_order;
- unsigned int new_nr = 1 << new_order;
+ unsigned int nr = 1 << order;
- if (mem_cgroup_disabled() || !folio_memcg_charged(folio))
+ if (!memcg_data)
return;
> > - for (i = new_nr; i < old_nr; i += new_nr)
- folio_page(folio, i)->memcg_data = folio->memcg_data;
+ VM_BUG_ON_PAGE((memcg_data & OBJEXTS_FLAGS_MASK) != MEMCG_DATA_KMEM,
+ first);
+ objcg = (void *)(memcg_data & ~OBJEXTS_FLAGS_MASK);
I'm not sure if dropping the
if (mem_cgroup_disabled() || !folio_memcg_charged(folio))
end adding that OBJEXTS_FLAGS_MASK magic here is the right thing to do.
It also isn't really part of a revert of b8791381d7ed.
--
Cheers,
David / dhildenb
