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>
This commit is contained in:
Vladimir Davydov 2014-10-09 15:28:47 -07:00 committed by Linus Torvalds
parent f3bb3043a0
commit 6f817f4cda
3 changed files with 28 additions and 52 deletions

View File

@ -440,7 +440,6 @@ void __memcg_kmem_uncharge_pages(struct page *page, int order);
int memcg_cache_id(struct mem_cgroup *memcg);
int memcg_update_cache_size(struct kmem_cache *s, int num_groups);
void memcg_update_array_size(int num_groups);
struct kmem_cache *

View File

@ -2958,55 +2958,6 @@ void memcg_update_array_size(int num)
memcg_limited_groups_array_size = num;
}
int memcg_update_cache_size(struct kmem_cache *s, int num_groups)
{
struct memcg_cache_params *cur_params = s->memcg_params;
struct memcg_cache_params *new_params;
size_t size;
int i;
VM_BUG_ON(!is_root_cache(s));
size = num_groups * sizeof(void *);
size += offsetof(struct memcg_cache_params, memcg_caches);
new_params = kzalloc(size, GFP_KERNEL);
if (!new_params)
return -ENOMEM;
new_params->is_root_cache = true;
/*
* There is the chance it will be bigger than
* memcg_limited_groups_array_size, if we failed an allocation
* in a cache, in which case all caches updated before it, will
* have a bigger array.
*
* But if that is the case, the data after
* memcg_limited_groups_array_size is certainly unused
*/
for (i = 0; i < memcg_limited_groups_array_size; i++) {
if (!cur_params->memcg_caches[i])
continue;
new_params->memcg_caches[i] =
cur_params->memcg_caches[i];
}
/*
* Ideally, we would wait until all caches succeed, and only
* then free the old one. But this is not worth the extra
* pointer per-cache we'd have to have for this.
*
* It is not a big deal if some caches are left with a size
* bigger than the others. And all updates will reset this
* anyway.
*/
rcu_assign_pointer(s->memcg_params, new_params);
if (cur_params)
kfree_rcu(cur_params, rcu_head);
return 0;
}
static void memcg_register_cache(struct mem_cgroup *memcg,
struct kmem_cache *root_cache)
{

View File

@ -148,6 +148,33 @@ static void memcg_free_cache_params(struct kmem_cache *s)
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 @@ int memcg_update_all_caches(int num_memcgs)
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.
*/