On Thu, Jun 18, 2020 at 10:37:07AM +0200, Vlastimil Babka wrote:
> On 6/10/20 6:31 PM, Vlastimil Babka wrote:
> > There are few places that call kmem_cache_debug(s) (which tests if any of debug
> > flags are enabled for a cache) immediatelly followed by a test for a specific
> > flag. The compiler can probably eliminate the extra check, but we can make the
> > code nicer by introducing kmem_cache_debug_flags() that works like
> > kmem_cache_debug() (including the static key check) but tests for specifig
> > flag(s). The next patches will add more users.
> >
> > Signed-off-by: Vlastimil Babka <vbabka@xxxxxxx>
>
> Please add this fixup per reviews.
> ----8<----
> From 25793252a31a36f8d1d4ccf0f27ed3e43fba54d8 Mon Sep 17 00:00:00 2001
> From: Vlastimil Babka <vbabka@xxxxxxx>
> Date: Thu, 18 Jun 2020 10:34:53 +0200
> Subject: [PATCH] mm, slub: introduce kmem_cache_debug_flags()-fix
>
> Change return from int to bool, per Kees.
> Add VM_WARN_ON_ONCE() for invalid flags, per Roman.
>
> Signed-off-by: Vlastimil Babka <vbabka@xxxxxxx>
Acked-by: Roman Gushchin <guro@xxxxxx>
Thanks!
> ---
> mm/slub.c | 7 ++++---
> 1 file changed, 4 insertions(+), 3 deletions(-)
>
> diff --git a/mm/slub.c b/mm/slub.c
> index c8e8b4ae2451..59d19c64069e 100644
> --- a/mm/slub.c
> +++ b/mm/slub.c
> @@ -127,16 +127,17 @@ DEFINE_STATIC_KEY_FALSE(slub_debug_enabled);
> * cache. Use only for flags parsed by setup_slub_debug() as it also enables
> * the static key.
> */
> -static inline int kmem_cache_debug_flags(struct kmem_cache *s, slab_flags_t flags)
> +static inline bool kmem_cache_debug_flags(struct kmem_cache *s, slab_flags_t flags)
> {
> + VM_WARN_ON_ONCE(!(flags & SLAB_DEBUG_FLAGS));
> #ifdef CONFIG_SLUB_DEBUG
> if (static_branch_unlikely(&slub_debug_enabled))
> return s->flags & flags;
> #endif
> - return 0;
> + return false;
> }
>
> -static inline int kmem_cache_debug(struct kmem_cache *s)
> +static inline bool kmem_cache_debug(struct kmem_cache *s)
> {
> return kmem_cache_debug_flags(s, SLAB_DEBUG_FLAGS);
> }
> --
> 2.27.0
>
>
