Merge branch 'for-linus' of git://git.kernel.dk/data/git/linux-2.6-block

[sfrench/cifs-2.6.git] / include / linux / slub_def.h

diff --git a/include/linux/slub_def.h b/include/linux/slub_def.h
index 0764c829d967ab8c1841cddf79ba51204956e4a8..a582f677152520ae1cf8f2a3e802030b4873b4d8 100644 (file)
--- a/include/linux/slub_def.h
+++ b/include/linux/slub_def.h
@@ -28,7 +28,7 @@ struct kmem_cache {
        int size;               /* The size of an object including meta data */
        int objsize;            /* The size of an object without meta data */
        int offset;             /* Free pointer offset. */
-       unsigned int order;
+       int order;
 
        /*
         * Avoid an extra cache line for UP, SMP and for the node local to
@@ -56,7 +56,13 @@ struct kmem_cache {
 /*
  * Kmalloc subsystem.
  */
-#define KMALLOC_SHIFT_LOW 3
+#if defined(ARCH_KMALLOC_MINALIGN) && ARCH_KMALLOC_MINALIGN > 8
+#define KMALLOC_MIN_SIZE ARCH_KMALLOC_MINALIGN
+#else
+#define KMALLOC_MIN_SIZE 8
+#endif
+
+#define KMALLOC_SHIFT_LOW ilog2(KMALLOC_MIN_SIZE)
 
 /*
  * We keep the general caches in an array of slab caches that are used for
@@ -70,15 +76,15 @@ extern struct kmem_cache kmalloc_caches[KMALLOC_SHIFT_HIGH + 1];
  */
 static inline int kmalloc_index(size_t size)
 {
-       /*
-        * We should return 0 if size == 0 but we use the smallest object
-        * here for SLAB legacy reasons.
-        */
-       WARN_ON_ONCE(size == 0);
+       if (!size)
+               return 0;
 
        if (size > KMALLOC_MAX_SIZE)
                return -1;
 
+       if (size <= KMALLOC_MIN_SIZE)
+               return KMALLOC_SHIFT_LOW;
+
        if (size > 64 && size <= 96)
                return 1;
        if (size > 128 && size <= 192)
@@ -153,13 +159,28 @@ static inline struct kmem_cache *kmalloc_slab(size_t size)
 #define SLUB_DMA 0
 #endif
 
+
+/*
+ * ZERO_SIZE_PTR will be returned for zero sized kmalloc requests.
+ *
+ * Dereferencing ZERO_SIZE_PTR will lead to a distinct access fault.
+ *
+ * ZERO_SIZE_PTR can be passed to kfree though in the same way that NULL can.
+ * Both make kfree a no-op.
+ */
+#define ZERO_SIZE_PTR ((void *)16)
+
+
+void *kmem_cache_alloc(struct kmem_cache *, gfp_t);
+void *__kmalloc(size_t size, gfp_t flags);
+
 static inline void *kmalloc(size_t size, gfp_t flags)
 {
        if (__builtin_constant_p(size) && !(flags & SLUB_DMA)) {
                struct kmem_cache *s = kmalloc_slab(size);
 
                if (!s)
-                       return NULL;
+                       return ZERO_SIZE_PTR;
 
                return kmem_cache_alloc(s, flags);
        } else
@@ -172,7 +193,7 @@ static inline void *kzalloc(size_t size, gfp_t flags)
                struct kmem_cache *s = kmalloc_slab(size);
 
                if (!s)
-                       return NULL;
+                       return ZERO_SIZE_PTR;
 
                return kmem_cache_zalloc(s, flags);
        } else
@@ -180,7 +201,8 @@ static inline void *kzalloc(size_t size, gfp_t flags)
 }
 
 #ifdef CONFIG_NUMA
-extern void *__kmalloc_node(size_t size, gfp_t flags, int node);
+void *__kmalloc_node(size_t size, gfp_t flags, int node);
+void *kmem_cache_alloc_node(struct kmem_cache *, gfp_t flags, int node);
 
 static inline void *kmalloc_node(size_t size, gfp_t flags, int node)
 {
@@ -188,7 +210,7 @@ static inline void *kmalloc_node(size_t size, gfp_t flags, int node)
                struct kmem_cache *s = kmalloc_slab(size);
 
                if (!s)
-                       return NULL;
+                       return ZERO_SIZE_PTR;
 
                return kmem_cache_alloc_node(s, flags, node);
        } else