mm: remove references to folio in __memcg_kmem_uncharge_page()

This use of folios is misleading because these pages are not part of
a folio.  Remove an unnecessary call to page_folio(), saving 58 bytes
of text in a Debian kernel build.

Link: https://lkml.kernel.org/r/20250314133617.138071-6-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
Acked-by: Roman Gushchin <roman.gushchin@linux.dev>
Cc: David Hildenbrand <david@redhat.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index d95b1f4216ac49527554db5a2ab136b0935465e4..57cf5a6c279c5e04ee2b9d58dd78b940d9d0ff2c 100644 (file)
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -2726,16 +2726,14 @@ int __memcg_kmem_charge_page(struct page *page, gfp_t gfp, int order)
  */
 void __memcg_kmem_uncharge_page(struct page *page, int order)
 {
-       struct folio *folio = page_folio(page);
-       struct obj_cgroup *objcg;
+       struct obj_cgroup *objcg = page_objcg(page);
        unsigned int nr_pages = 1 << order;
 
-       if (!folio_memcg_kmem(folio))
+       if (!objcg)
                return;
 
-       objcg = __folio_objcg(folio);
        obj_cgroup_uncharge_pages(objcg, nr_pages);
-       folio->memcg_data = 0;
+       page->memcg_data = 0;
        obj_cgroup_put(objcg);
 }