Merge branch 'slab/next' of git://git.kernel.org/pub/scm/linux/kernel/git/penberg...

[~andy/linux] / include / linux / slab.h

diff --git a/include/linux/slab.h b/include/linux/slab.h
index 1e2f4fe12773bdaf9c5ffddd9b5eb77d42b665a0..9260abdd67df801e002f18faf3f17bd00d494867 100644 (file)
--- a/include/linux/slab.h
+++ b/include/linux/slab.h
@@ -205,8 +205,8 @@ struct kmem_cache {
 
 #ifdef CONFIG_SLUB
 /*
- * SLUB allocates up to order 2 pages directly and otherwise
- * passes the request to the page allocator.
+ * SLUB directly allocates requests fitting in to an order-1 page
+ * (PAGE_SIZE*2).  Larger requests are passed to the page allocator.
  */
 #define KMALLOC_SHIFT_HIGH     (PAGE_SHIFT + 1)
 #define KMALLOC_SHIFT_MAX      (MAX_ORDER + PAGE_SHIFT)
@@ -217,12 +217,12 @@ struct kmem_cache {
 
 #ifdef CONFIG_SLOB
 /*
- * SLOB passes all page size and larger requests to the page allocator.
+ * SLOB passes all requests larger than one page to the page allocator.
  * No kmalloc array is necessary since objects of different sizes can
  * be allocated from the same page.
  */
-#define KMALLOC_SHIFT_MAX      30
 #define KMALLOC_SHIFT_HIGH     PAGE_SHIFT
+#define KMALLOC_SHIFT_MAX      30
 #ifndef KMALLOC_SHIFT_LOW
 #define KMALLOC_SHIFT_LOW      3
 #endif
@@ -513,7 +513,9 @@ static __always_inline void *kmalloc_node(size_t size, gfp_t flags, int node)
  *
  * 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.
+ * 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.
  *
  * Child caches will hold extra metadata needed for its operation. Fields are:
  *
@@ -528,7 +530,10 @@ static __always_inline void *kmalloc_node(size_t size, gfp_t flags, int node)
 struct memcg_cache_params {
        bool is_root_cache;
        union {
-               struct kmem_cache *memcg_caches[0];
+               struct {
+                       struct rcu_head rcu_head;
+                       struct kmem_cache *memcg_caches[0];
+               };
                struct {
                        struct mem_cgroup *memcg;
                        struct list_head list;