mm: memcontrol: account slab stats per lruvec

Josef's redesign of the balancing between slab caches and the page cache
requires slab cache statistics at the lruvec level.

Link: http://lkml.kernel.org/r/20170530181724.27197-7-hannes@cmpxchg.org
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Josef Bacik <josef@toxicpanda.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/slab.h

@@ -274,22 +274,11 @@ static __always_inline int memcg_charge_slab(struct page *page,
 					     gfp_t gfp, int order,
 					     struct kmem_cache *s)
 {
-	int ret;
-
 	if (!memcg_kmem_enabled())
 		return 0;
 	if (is_root_cache(s))
 		return 0;
-
-	ret = memcg_kmem_charge_memcg(page, gfp, order, s->memcg_params.memcg);
-	if (ret)
-		return ret;
-
-	mod_memcg_page_state(page,
-			     (s->flags & SLAB_RECLAIM_ACCOUNT) ?
-			     NR_SLAB_RECLAIMABLE : NR_SLAB_UNRECLAIMABLE,
-			     1 << order);
-	return 0;
+	return memcg_kmem_charge_memcg(page, gfp, order, s->memcg_params.memcg);
 }
 
 static __always_inline void memcg_uncharge_slab(struct page *page, int order,
@@ -297,11 +286,6 @@ static __always_inline void memcg_uncharge_slab(struct page *page, int order,
 {
 	if (!memcg_kmem_enabled())
 		return;
-
-	mod_memcg_page_state(page,
-			     (s->flags & SLAB_RECLAIM_ACCOUNT) ?
-			     NR_SLAB_RECLAIMABLE : NR_SLAB_UNRECLAIMABLE,
-			     -(1 << order));
 	memcg_kmem_uncharge(page, order);
 }