mm, slab: move memcg_cache_params structure to mm/slab.h

The memcg_cache_params structure is only embedded into the kmem_cache of
slab and slub allocators as defined in slab_def.h and slub_def.h and used
internally by mm code.  There is no needed to expose it in a public
header.  So move it from include/linux/slab.h to mm/slab.h.  It is just a
refactoring patch with no code change.

In fact both the slub_def.h and slab_def.h should be moved into the mm
directory as well, but that will probably cause many merge conflicts.

Link: http://lkml.kernel.org/r/20190718180827.18758-1-longman@redhat.com
Signed-off-by: Waiman Long <longman@redhat.com>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Roman Gushchin <guro@fb.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Michal Hocko <mhocko@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/include/linux/slab.h b/include/linux/slab.h
index 56c9c7e..ab2b98a 100644 (file)
--- a/include/linux/slab.h
+++ b/include/linux/slab.h
@@ -595,68 +595,6 @@ static __always_inline void *kmalloc_node(size_t size, gfp_t flags, int node)
        return __kmalloc_node(size, flags, node);
 }
 
-struct memcg_cache_array {
-       struct rcu_head rcu;
-       struct kmem_cache *entries[0];
-};
-
-/*
- * This is the main placeholder for memcg-related information in kmem caches.
- * Both the root cache and the child caches will have it. For the root cache,
- * this will hold a dynamically allocated array large enough to hold
- * information about the currently limited memcgs in the system. To allow the
- * array to be accessed without taking any locks, on relocation we free the old
- * version only after a grace period.
- *
- * Root and child caches hold different metadata.
- *
- * @root_cache:        Common to root and child caches.  NULL for root, pointer to
- *             the root cache for children.
- *
- * The following fields are specific to root caches.
- *
- * @memcg_caches: kmemcg ID indexed table of child caches.  This table is
- *             used to index child cachces during allocation and cleared
- *             early during shutdown.
- *
- * @root_caches_node: List node for slab_root_caches list.
- *
- * @children:  List of all child caches.  While the child caches are also
- *             reachable through @memcg_caches, a child cache remains on
- *             this list until it is actually destroyed.
- *
- * The following fields are specific to child caches.
- *
- * @memcg:     Pointer to the memcg this cache belongs to.
- *
- * @children_node: List node for @root_cache->children list.
- *
- * @kmem_caches_node: List node for @memcg->kmem_caches list.
- */
-struct memcg_cache_params {
-       struct kmem_cache *root_cache;
-       union {
-               struct {
-                       struct memcg_cache_array __rcu *memcg_caches;
-                       struct list_head __root_caches_node;
-                       struct list_head children;
-                       bool dying;
-               };
-               struct {
-                       struct mem_cgroup *memcg;
-                       struct list_head children_node;
-                       struct list_head kmem_caches_node;
-                       struct percpu_ref refcnt;
-
-                       void (*work_fn)(struct kmem_cache *);
-                       union {
-                               struct rcu_head rcu_head;
-                               struct work_struct work;
-                       };
-               };
-       };
-};
-
 int memcg_update_all_caches(int num_memcgs);
 
 /**

diff --git a/mm/slab.h b/mm/slab.h
index 5bf615c..68e455f 100644 (file)
--- a/mm/slab.h
+++ b/mm/slab.h
@@ -30,6 +30,69 @@ struct kmem_cache {
        struct list_head list;  /* List of all slab caches on the system */
 };
 
+#else /* !CONFIG_SLOB */
+
+struct memcg_cache_array {
+       struct rcu_head rcu;
+       struct kmem_cache *entries[0];
+};
+
+/*
+ * This is the main placeholder for memcg-related information in kmem caches.
+ * Both the root cache and the child caches will have it. For the root cache,
+ * this will hold a dynamically allocated array large enough to hold
+ * information about the currently limited memcgs in the system. To allow the
+ * array to be accessed without taking any locks, on relocation we free the old
+ * version only after a grace period.
+ *
+ * Root and child caches hold different metadata.
+ *
+ * @root_cache:        Common to root and child caches.  NULL for root, pointer to
+ *             the root cache for children.
+ *
+ * The following fields are specific to root caches.
+ *
+ * @memcg_caches: kmemcg ID indexed table of child caches.  This table is
+ *             used to index child cachces during allocation and cleared
+ *             early during shutdown.
+ *
+ * @root_caches_node: List node for slab_root_caches list.
+ *
+ * @children:  List of all child caches.  While the child caches are also
+ *             reachable through @memcg_caches, a child cache remains on
+ *             this list until it is actually destroyed.
+ *
+ * The following fields are specific to child caches.
+ *
+ * @memcg:     Pointer to the memcg this cache belongs to.
+ *
+ * @children_node: List node for @root_cache->children list.
+ *
+ * @kmem_caches_node: List node for @memcg->kmem_caches list.
+ */
+struct memcg_cache_params {
+       struct kmem_cache *root_cache;
+       union {
+               struct {
+                       struct memcg_cache_array __rcu *memcg_caches;
+                       struct list_head __root_caches_node;
+                       struct list_head children;
+                       bool dying;
+               };
+               struct {
+                       struct mem_cgroup *memcg;
+                       struct list_head children_node;
+                       struct list_head kmem_caches_node;
+                       struct percpu_ref refcnt;
+
+                       void (*work_fn)(struct kmem_cache *);
+                       union {
+                               struct rcu_head rcu_head;
+                               struct work_struct work;
+                       };
+               };
+       };
+};
 #endif /* CONFIG_SLOB */
 
 #ifdef CONFIG_SLAB