slub: kmalloc page allocator pass-through cleanup

This adds a proper function for kmalloc page allocator pass-through. While it
simplifies any code that does slab tracing code a lot, I think it's a
worthwhile cleanup in itself.
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Christoph Lameter <clameter@sgi.com>

include/linux/slub_def.h

@@ -188,12 +188,16 @@ static __always_inline struct kmem_cache *kmalloc_slab(size_t size)
 void *kmem_cache_alloc(struct kmem_cache *, gfp_t);
 void *__kmalloc(size_t size, gfp_t flags);
 
+static __always_inline void *kmalloc_large(size_t size, gfp_t flags)
+{
+	return (void *)__get_free_pages(flags | __GFP_COMP, get_order(size));
+}
+
 static __always_inline void *kmalloc(size_t size, gfp_t flags)
 {
 	if (__builtin_constant_p(size)) {
 		if (size > PAGE_SIZE / 2)
-			return (void *)__get_free_pages(flags | __GFP_COMP,
-							get_order(size));
+			return kmalloc_large(size, flags);
 
 		if (!(flags & SLUB_DMA)) {
 			struct kmem_cache *s = kmalloc_slab(size);

mm/slub.c

@@ -2671,8 +2671,7 @@ void *__kmalloc(size_t size, gfp_t flags)
 	struct kmem_cache *s;
 
 	if (unlikely(size > PAGE_SIZE / 2))
-		return (void *)__get_free_pages(flags | __GFP_COMP,
-							get_order(size));
+		return kmalloc_large(size, flags);
 
 	s = get_slab(size, flags);
 
@@ -2689,8 +2688,7 @@ void *__kmalloc_node(size_t size, gfp_t flags, int node)
 	struct kmem_cache *s;
 
 	if (unlikely(size > PAGE_SIZE / 2))
-		return (void *)__get_free_pages(flags | __GFP_COMP,
-							get_order(size));
+		return kmalloc_large(size, flags);
 
 	s = get_slab(size, flags);
 
@@ -3219,8 +3217,8 @@ void *__kmalloc_track_caller(size_t size, gfp_t gfpflags, void *caller)
 	struct kmem_cache *s;
 
 	if (unlikely(size > PAGE_SIZE / 2))
-		return (void *)__get_free_pages(gfpflags | __GFP_COMP,
-							get_order(size));
+		return kmalloc_large(size, gfpflags);
+
 	s = get_slab(size, gfpflags);
 
 	if (unlikely(ZERO_OR_NULL_PTR(s)))
@@ -3235,8 +3233,8 @@ void *__kmalloc_node_track_caller(size_t size, gfp_t gfpflags,
 	struct kmem_cache *s;
 
 	if (unlikely(size > PAGE_SIZE / 2))
-		return (void *)__get_free_pages(gfpflags | __GFP_COMP,
-							get_order(size));
+		return kmalloc_large(size, gfpflags);
+
 	s = get_slab(size, gfpflags);
 
 	if (unlikely(ZERO_OR_NULL_PTR(s)))