2021-07-02 08:55:26

by Yee Lee (李建誼)

Subject: [PATCH v4 1/2] mm: introduce helper to check slub_debug_enabled

From: Marco Elver <[email protected]>

Introduce a helper to check slub_debug_enabled, so that we can confine
the use of #ifdef to the definition of the slub_debug_enabled_unlikely()
helper.

---

Signed-off-by: Marco Elver <[email protected]>
Signed-off-by: Yee Lee <[email protected]>

---
mm/slab.h | 15 +++++++++++----
1 file changed, 11 insertions(+), 4 deletions(-)

diff --git a/mm/slab.h b/mm/slab.h
index 7b60ef2f32c3..a11126afe24c 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_unlikely(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_unlikely(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_unlikely())
return s->flags & flags;
-#endif
return false;
}

--
2.18.0

2021-07-02 09:36:19

by Marco Elver

Subject: Re: [PATCH v4 1/2] mm: introduce helper to check slub_debug_enabled

On Fri, 2 Jul 2021 at 10:54, <[email protected]> wrote:
>
> From: Marco Elver <[email protected]>
>
> Introduce a helper to check slub_debug_enabled, so that we can confine
> the use of #ifdef to the definition of the slub_debug_enabled_unlikely()
> helper.
>
> ---

^^ this '---' is wrong. It needs to be removed, because anything after
the first '---' will be discarded if it is turned into a commit by the
maintainer.


> Signed-off-by: Marco Elver <[email protected]>
> Signed-off-by: Yee Lee <[email protected]>
>
> ---
> mm/slab.h | 15 +++++++++++----
> 1 file changed, 11 insertions(+), 4 deletions(-)
>
> diff --git a/mm/slab.h b/mm/slab.h
> index 7b60ef2f32c3..a11126afe24c 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_unlikely(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_unlikely(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_unlikely())
> return s->flags & flags;
> -#endif
> return false;
> }
>
> --
> 2.18.0