mm/slab_common: move kmem_cache definition to internal header

We don't need to keep kmem_cache definition in include/linux/slab.h if we
don't need to inline kmem_cache_size().  According to my code inspection,
this function is only called at lc_create() in lib/lru_cache.c which may
be called at initialization phase of something, so we don't need to inline
it.  Therfore, move it to slab_common.c and move kmem_cache definition to
internal header.

After this change, we can change kmem_cache definition easily without full
kernel build.  For instance, we can turn on/off CONFIG_SLUB_STATS without
full kernel build.

[akpm@linux-foundation.org: export kmem_cache_size() to modules]
[rdunlap@infradead.org: add header files to fix kmemcheck.c build errors]
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Acked-by: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Zhang Yanfei <zhangyanfei@cn.fujitsu.com>
Signed-off-by: Randy Dunlap <rdunlap@infradead.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 1d9abb7..9062e4a 100644
--- a/include/linux/slab.h
+++ b/include/linux/slab.h
@@ -158,31 +158,6 @@
 #define ARCH_KMALLOC_MINALIGN __alignof__(unsigned long long)
 #endif
 
-#ifdef CONFIG_SLOB
-/*
- * Common fields provided in kmem_cache by all slab allocators
- * This struct is either used directly by the allocator (SLOB)
- * or the allocator must include definitions for all fields
- * provided in kmem_cache_common in their definition of kmem_cache.
- *
- * Once we can do anonymous structs (C11 standard) we could put a
- * anonymous struct definition in these allocators so that the
- * separate allocations in the kmem_cache structure of SLAB and
- * SLUB is no longer needed.
- */
-struct kmem_cache {
-	unsigned int object_size;/* The original size of the object */
-	unsigned int size;	/* The aligned/padded/added on size  */
-	unsigned int align;	/* Alignment as calculated */
-	unsigned long flags;	/* Active flags on the slab */
-	const char *name;	/* Slab name for sysfs */
-	int refcount;		/* Use counter */
-	void (*ctor)(void *);	/* Called on object slot creation */
-	struct list_head list;	/* List of all slab caches on the system */
-};
-
-#endif /* CONFIG_SLOB */
-
 /*
  * Kmalloc array related definitions
  */
@@ -363,14 +338,6 @@
 }
 #endif /* CONFIG_TRACING */
 
-#ifdef CONFIG_SLAB
-#include <linux/slab_def.h>
-#endif
-
-#ifdef CONFIG_SLUB
-#include <linux/slub_def.h>
-#endif
-
 extern void *kmalloc_order(size_t size, gfp_t flags, unsigned int order);
 
 #ifdef CONFIG_TRACING
@@ -650,14 +617,7 @@
 	return kmalloc_node(size, flags | __GFP_ZERO, node);
 }
 
-/*
- * Determine the size of a slab object
- */
-static inline unsigned int kmem_cache_size(struct kmem_cache *s)
-{
-	return s->object_size;
-}
-
+unsigned int kmem_cache_size(struct kmem_cache *s);
 void __init kmem_cache_init_late(void);
 
 #endif	/* _LINUX_SLAB_H */