[PATCH v6 1/2] mm: move helper to check slub_debug_enabled

[yee.lee]

From: Marco Elver <elver@xxxxxxxxxx>

Move the helper to check slub_debug_enabled, so that we can confine
the use of #ifdef outside slub.c as well.

Suggested-by: Matthew Wilcox <willy@xxxxxxxxxxxxx>
Signed-off-by: Marco Elver <elver@xxxxxxxxxx>
Signed-off-by: Yee Lee <yee.lee@xxxxxxxxxxxx>
---
 mm/slab.h | 15 +++++++++++----
 mm/slub.c | 14 --------------
 2 files changed, 11 insertions(+), 18 deletions(-)

diff --git a/mm/slab.h b/mm/slab.h
index 7b60ef2f32c3..67d3272f3368 100644
--- a/mm/slab.h
+++ b/mm/slab.h
@@ -216,10 +216,18 @@ DECLARE_STATIC_KEY_FALSE(slub_debug_enabled);
 #endif
 extern void print_tracking(struct kmem_cache *s, void *object);
 long validate_slab_cache(struct kmem_cache *s);
+static inline bool __slub_debug_enabled(void)
+{
+	return static_branch_unlikely(&slub_debug_enabled);
+}
 #else
 static inline void print_tracking(struct kmem_cache *s, void *object)
 {
 }
+static inline bool __slub_debug_enabled(void)
+{
+	return false;
+}
 #endif
 
 /*
@@ -229,11 +237,10 @@ static inline void print_tracking(struct kmem_cache *s, void *object)
  */
 static inline bool kmem_cache_debug_flags(struct kmem_cache *s, slab_flags_t flags)
 {
-#ifdef CONFIG_SLUB_DEBUG
-	VM_WARN_ON_ONCE(!(flags & SLAB_DEBUG_FLAGS));
-	if (static_branch_unlikely(&slub_debug_enabled))
+	if (IS_ENABLED(CONFIG_SLUB_DEBUG))
+		VM_WARN_ON_ONCE(!(flags & SLAB_DEBUG_FLAGS));
+	if (__slub_debug_enabled())
 		return s->flags & flags;
-#endif
 	return false;
 }
 
diff --git a/mm/slub.c b/mm/slub.c
index 3bc8b940c933..71515c484d1c 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -119,25 +119,11 @@
  */
 
 #ifdef CONFIG_SLUB_DEBUG
-
 #ifdef CONFIG_SLUB_DEBUG_ON
 DEFINE_STATIC_KEY_TRUE(slub_debug_enabled);
 #else
 DEFINE_STATIC_KEY_FALSE(slub_debug_enabled);
 #endif
-
-static inline bool __slub_debug_enabled(void)
-{
-	return static_branch_unlikely(&slub_debug_enabled);
-}
-
-#else		/* CONFIG_SLUB_DEBUG */
-
-static inline bool __slub_debug_enabled(void)
-{
-	return false;
-}
-
 #endif		/* CONFIG_SLUB_DEBUG */
 
 static inline bool kmem_cache_debug(struct kmem_cache *s)
-- 
2.18.0