memcg: move memcg_{alloc,free}_cache_params to slab_common.c

The only reason why they live in memcontrol.c is that we get/put css
reference to the owner memory cgroup in them.  However, we can do that in
memcg_{un,}register_cache.  OTOH, there are several reasons to move them
to slab_common.c.

First, I think that the less public interface functions we have in
memcontrol.h the better.  Since the functions I move don't depend on
memcontrol, I think it's worth making them private to slab, especially
taking into account that the arrays are defined on the slab's side too.

Second, the way how per-memcg arrays are updated looks rather awkward: it
proceeds from memcontrol.c (__memcg_activate_kmem) to slab_common.c
(memcg_update_all_caches) and back to memcontrol.c again
(memcg_update_array_size).  In the following patches I move the function
relocating the arrays (memcg_update_array_size) to slab_common.c and
therefore get rid this circular call path.  I think we should have the
cache allocation stuff in the same place where we have relocation, because
it's easier to follow the code then.  So I move arrays alloc/free
functions to slab_common.c too.

The third point isn't obvious.  I'm going to make the list_lru structure
per-memcg to allow targeted kmem reclaim.  That means we will have
per-memcg arrays in list_lrus too.  It turns out that it's much easier to
update these arrays in list_lru.c rather than in memcontrol.c, because all
the stuff we need is defined there.  This patch makes memcg caches arrays
allocation path conform that of the upcoming list_lru.

So let's move these functions to slab_common.c and make them static.

Signed-off-by: Vladimir Davydov <[email protected]>
Acked-by: Johannes Weiner <[email protected]>
Acked-by: Michal Hocko <[email protected]>
Cc: Christoph Lameter <[email protected]>
Cc: Glauber Costa <[email protected]>
Cc: Joonsoo Kim <[email protected]>
Cc: David Rientjes <[email protected]>
Cc: Pekka Enberg <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

0 files changed, 0 insertions, 0 deletions