memcg: simplify and inline __mem_cgroup_from_kmem

Before the previous patch ("memcg: unify slab and other kmem pages
charging"), __mem_cgroup_from_kmem had to handle two types of kmem - slab
pages and pages allocated with alloc_kmem_pages - memcg in the page
struct.  Now we can unify it.  Since after it, this function becomes tiny
we can fold it into mem_cgroup_from_kmem.

[hughd@google.com: move mem_cgroup_from_kmem into list_lru.c]
Signed-off-by: Vladimir Davydov <vdavydov@virtuozzo.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
index 0ba4c86..998311e 100644 (file)
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h
@@ -770,8 +770,6 @@ static inline int memcg_cache_id(struct mem_cgroup *memcg)
 struct kmem_cache *__memcg_kmem_get_cache(struct kmem_cache *cachep);
 void __memcg_kmem_put_cache(struct kmem_cache *cachep);
 
-struct mem_cgroup *__mem_cgroup_from_kmem(void *ptr);
-
 static inline bool __memcg_kmem_bypass(gfp_t gfp)
 {
        if (!memcg_kmem_enabled())
@@ -830,13 +828,6 @@ static __always_inline void memcg_kmem_put_cache(struct kmem_cache *cachep)
        if (memcg_kmem_enabled())
                __memcg_kmem_put_cache(cachep);
 }
-
-static __always_inline struct mem_cgroup *mem_cgroup_from_kmem(void *ptr)
-{
-       if (!memcg_kmem_enabled())
-               return NULL;
-       return __mem_cgroup_from_kmem(ptr);
-}
 #else
 #define for_each_memcg_cache_index(_idx)       \
        for (; NULL; )
@@ -882,11 +873,5 @@ memcg_kmem_get_cache(struct kmem_cache *cachep, gfp_t gfp)
 static inline void memcg_kmem_put_cache(struct kmem_cache *cachep)
 {
 }
-
-static inline struct mem_cgroup *mem_cgroup_from_kmem(void *ptr)
-{
-       return NULL;
-}
 #endif /* CONFIG_MEMCG_KMEM */
 #endif /* _LINUX_MEMCONTROL_H */
-

diff --git a/mm/list_lru.c b/mm/list_lru.c
index 2823747..afc71ea 100644 (file)
--- a/mm/list_lru.c
+++ b/mm/list_lru.c
@@ -63,6 +63,16 @@ list_lru_from_memcg_idx(struct list_lru_node *nlru, int idx)
        return &nlru->lru;
 }
 
+static __always_inline struct mem_cgroup *mem_cgroup_from_kmem(void *ptr)
+{
+       struct page *page;
+
+       if (!memcg_kmem_enabled())
+               return NULL;
+       page = virt_to_head_page(ptr);
+       return page->mem_cgroup;
+}
+
 static inline struct list_lru_one *
 list_lru_from_kmem(struct list_lru_node *nlru, void *ptr)
 {

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 9575cff..c0111cb 100644 (file)
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -2430,24 +2430,6 @@ void __memcg_kmem_uncharge(struct page *page, int order)
        page->mem_cgroup = NULL;
        css_put_many(&memcg->css, nr_pages);
 }
-
-struct mem_cgroup *__mem_cgroup_from_kmem(void *ptr)
-{
-       struct mem_cgroup *memcg = NULL;
-       struct kmem_cache *cachep;
-       struct page *page;
-
-       page = virt_to_head_page(ptr);
-       if (PageSlab(page)) {
-               cachep = page->slab_cache;
-               if (!is_root_cache(cachep))
-                       memcg = cachep->memcg_params.memcg;
-       } else
-               /* page allocated by alloc_kmem_pages */
-               memcg = page->mem_cgroup;
-
-       return memcg;
-}
 #endif /* CONFIG_MEMCG_KMEM */
 
 #ifdef CONFIG_TRANSPARENT_HUGEPAGE