SLUB: clean up krealloc

We really do not need all this gaga there.

ksize gives us all the information we need to figure out if the object can
cope with the new size.
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/slub.c

@@ -2199,9 +2199,8 @@ EXPORT_SYMBOL(kmem_cache_shrink);
  */
 void *krealloc(const void *p, size_t new_size, gfp_t flags)
 {
-	struct kmem_cache *new_cache;
 	void *ret;
-	struct page *page;
+	size_t ks;
 
 	if (unlikely(!p))
 		return kmalloc(new_size, flags);
@@ -2211,19 +2210,13 @@ void *krealloc(const void *p, size_t new_size, gfp_t flags)
 		return NULL;
 	}
 
-	page = virt_to_head_page(p);
-
-	new_cache = get_slab(new_size, flags);
-
-	/*
- 	 * If new size fits in the current cache, bail out.
- 	 */
-	if (likely(page->slab == new_cache))
+	ks = ksize(p);
+	if (ks >= new_size)
 		return (void *)p;
 
 	ret = kmalloc(new_size, flags);
 	if (ret) {
-		memcpy(ret, p, min(new_size, ksize(p)));
+		memcpy(ret, p, min(new_size, ks));
 		kfree(p);
 	}
 	return ret;