memcg: move memcg_update_cache_size() to slab_common.c
`While growing per memcg caches arrays, we jump between memcontrol.c and
slab_common.c in a weird way:
memcg_alloc_cache_id - memcontrol.c
memcg_update_all_caches - slab_common.c
memcg_update_cache_size - memcontrol.c
There's absolutely no reason why memcg_update_cache_size can't live on the
slab's side though. So let's move it there and settle it comfortably amid
per-memcg cache allocation functions.
Besides, this patch cleans this function up a bit, removing all the
useless comments from it, and renames it to memcg_update_cache_params to
conform to memcg_alloc/free_cache_params, which we already have in
slab_common.c.
Signed-off-by: Vladimir Davydov <vdavydov@parallels.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Michal Hocko <mhocko@suse.cz>
Cc: Christoph Lameter <cl@linux.com>
Cc: Glauber Costa <glommer@gmail.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Pekka Enberg <penberg@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/slab_common.c b/mm/slab_common.c
index c2a8661..3a6e0cf 100644
--- a/mm/slab_common.c
+++ b/mm/slab_common.c
@@ -148,6 +148,33 @@
kfree(s->memcg_params);
}
+static int memcg_update_cache_params(struct kmem_cache *s, int num_memcgs)
+{
+ int size;
+ struct memcg_cache_params *new_params, *cur_params;
+
+ BUG_ON(!is_root_cache(s));
+
+ size = offsetof(struct memcg_cache_params, memcg_caches);
+ size += num_memcgs * sizeof(void *);
+
+ new_params = kzalloc(size, GFP_KERNEL);
+ if (!new_params)
+ return -ENOMEM;
+
+ cur_params = s->memcg_params;
+ memcpy(new_params->memcg_caches, cur_params->memcg_caches,
+ memcg_limited_groups_array_size * sizeof(void *));
+
+ new_params->is_root_cache = true;
+
+ rcu_assign_pointer(s->memcg_params, new_params);
+ if (cur_params)
+ kfree_rcu(cur_params, rcu_head);
+
+ return 0;
+}
+
int memcg_update_all_caches(int num_memcgs)
{
struct kmem_cache *s;
@@ -158,9 +185,8 @@
if (!is_root_cache(s))
continue;
- ret = memcg_update_cache_size(s, num_memcgs);
+ ret = memcg_update_cache_params(s, num_memcgs);
/*
- * See comment in memcontrol.c, memcg_update_cache_size:
* Instead of freeing the memory, we'll just leave the caches
* up to this point in an updated state.
*/