slab: introduce __kmemcg_cache_deactivate()

__kmem_cache_shrink() is called with %true @deactivate only for memcg
caches.  Remove @deactivate from __kmem_cache_shrink() and introduce
__kmemcg_cache_deactivate() instead.  Each memcg-supporting allocator
should implement it and it should deactivate and drain the cache.

This is to allow memcg cache deactivation behavior to further deviate
from simple shrinking without messing up __kmem_cache_shrink().

This is pure reorganization and doesn't introduce any observable
behavior changes.

v2: Dropped unnecessary ifdef in mm/slab.h as suggested by Vladimir.

Link: http://lkml.kernel.org/r/20170117235411.9408-8-tj@kernel.org
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 2 insertions, 2 deletions

diff --git a/mm/slab_common.c b/mm/slab_common.c
index 274697e1a42a..59e41bb81575 100644
--- a/mm/slab_common.c
+++ b/mm/slab_common.c
@@ -646,7 +646,7 @@ void memcg_deactivate_kmem_caches(struct mem_cgroup *memcg)
                 if (!c)
                         continue;
 
-                __kmem_cache_shrink(c, true);
+                __kmemcg_cache_deactivate(c);
                 arr->entries[idx] = NULL;
         }
         mutex_unlock(&slab_mutex);
@@ -794,7 +794,7 @@ int kmem_cache_shrink(struct kmem_cache *cachep)
         get_online_cpus();
         get_online_mems();
         kasan_cache_shrink(cachep);
-        ret = __kmem_cache_shrink(cachep, false);
+        ret = __kmem_cache_shrink(cachep);
         put_online_mems();
         put_online_cpus();
         return ret;