Re: [PATCH v2 2/5] mm/slub: query dynamic DEBUG_PAGEALLOC setting

[Christian Borntraeger]

On 02/11/2016 05:04 AM, js1304@xxxxxxxxx wrote:
> From: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx>
> 
> We can disable debug_pagealloc processing even if the code is compiled
> with CONFIG_DEBUG_PAGEALLOC. This patch changes the code to query
> whether it is enabled or not in runtime.
> 
> v2: clean up code, per Christian.
> 
> Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx>

Reviewed-by: Christian Borntraeger <borntraeger@xxxxxxxxxx>

> ---
>  mm/slub.c | 7 +++----
>  1 file changed, 3 insertions(+), 4 deletions(-)
> 
> diff --git a/mm/slub.c b/mm/slub.c
> index 606488b..a1874c2 100644
> --- a/mm/slub.c
> +++ b/mm/slub.c
> @@ -250,11 +250,10 @@ static inline void *get_freepointer_safe(struct kmem_cache *s, void *object)
>  {
>  	void *p;
> 
> -#ifdef CONFIG_DEBUG_PAGEALLOC
> +	if (!debug_pagealloc_enabled())
> +		return get_freepointer(s, object);
> +
>  	probe_kernel_read(&p, (void **)(object + s->offset), sizeof(p));
> -#else
> -	p = get_freepointer(s, object);
> -#endif
>  	return p;
>  }
>