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>

1 files changed, 9 insertions, 0 deletions

diff --git a/mm/slab_common.c b/mm/slab_common.c
index cabb842c4e7c..d7d8ffd0c306 100644
--- a/mm/slab_common.c
+++ b/mm/slab_common.c
@@ -30,6 +30,15 @@ LIST_HEAD(slab_caches);
 DEFINE_MUTEX(slab_mutex);
 struct kmem_cache *kmem_cache;
 
+/*
+ * Determine the size of a slab object
+ */
+unsigned int kmem_cache_size(struct kmem_cache *s)
+{
+	return s->object_size;
+}
+EXPORT_SYMBOL(kmem_cache_size);
+
 #ifdef CONFIG_DEBUG_VM
 static int kmem_cache_sanity_check(const char *name, size_t size)
 {