Make page->private usable in compound pages

[powerpc.git] / mm / slab.c

diff --git a/mm/slab.c b/mm/slab.c
index 00f98b9..f4b2e22 100644 (file)
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -389,7 +389,6 @@ struct kmem_cache {
        unsigned int buffer_size;
        u32 reciprocal_buffer_size;
 /* 3) touched by every alloc & free from the backend */
-       struct kmem_list3 *nodelists[MAX_NUMNODES];
 
        unsigned int flags;             /* constant flags */
        unsigned int num;               /* # of objs per slab */
@@ -444,6 +443,17 @@ struct kmem_cache {
        int obj_offset;
        int obj_size;
 #endif
+       /*
+        * We put nodelists[] at the end of kmem_cache, because we want to size
+        * this array to nr_node_ids slots instead of MAX_NUMNODES
+        * (see kmem_cache_init())
+        * We still use [MAX_NUMNODES] and not [1] or [0] because cache_cache
+        * is statically defined, so we reserve the max number of nodes.
+        */
+       struct kmem_list3 *nodelists[MAX_NUMNODES];
+       /*
+        * Do not add fields after nodelists[]
+        */
 };
 
 #define CFLGS_OFF_SLAB         (0x80000000UL)
@@ -592,8 +602,7 @@ static inline void page_set_cache(struct page *page, struct kmem_cache *cache)
 
 static inline struct kmem_cache *page_get_cache(struct page *page)
 {
-       if (unlikely(PageCompound(page)))
-               page = (struct page *)page_private(page);
+       page = compound_head(page);
        BUG_ON(!PageSlab(page));
        return (struct kmem_cache *)page->lru.next;
 }
@@ -605,8 +614,7 @@ static inline void page_set_slab(struct page *page, struct slab *slab)
 
 static inline struct slab *page_get_slab(struct page *page)
 {
-       if (unlikely(PageCompound(page)))
-               page = (struct page *)page_private(page);
+       page = compound_head(page);
        BUG_ON(!PageSlab(page));
        return (struct slab *)page->lru.prev;
 }
@@ -678,9 +686,6 @@ static struct kmem_cache cache_cache = {
        .shared = 1,
        .buffer_size = sizeof(struct kmem_cache),
        .name = "kmem_cache",
-#if DEBUG
-       .obj_size = sizeof(struct kmem_cache),
-#endif
 };
 
 #define BAD_ALIEN_MAGIC 0x01020304ul
@@ -1440,6 +1445,15 @@ void __init kmem_cache_init(void)
        cache_cache.array[smp_processor_id()] = &initarray_cache.cache;
        cache_cache.nodelists[node] = &initkmem_list3[CACHE_CACHE];
 
+       /*
+        * struct kmem_cache size depends on nr_node_ids, which
+        * can be less than MAX_NUMNODES.
+        */
+       cache_cache.buffer_size = offsetof(struct kmem_cache, nodelists) +
+                                nr_node_ids * sizeof(struct kmem_list3 *);
+#if DEBUG
+       cache_cache.obj_size = cache_cache.buffer_size;
+#endif
        cache_cache.buffer_size = ALIGN(cache_cache.buffer_size,
                                        cache_line_size());
        cache_cache.reciprocal_buffer_size =
@@ -1933,7 +1947,7 @@ static void slab_destroy(struct kmem_cache *cachep, struct slab *slabp)
  * For setting up all the kmem_list3s for cache whose buffer_size is same as
  * size of kmem_list3.
  */
-static void set_up_list3s(struct kmem_cache *cachep, int index)
+static void __init set_up_list3s(struct kmem_cache *cachep, int index)
 {
        int node;