On 02/04/2016 06:56 AM, Joonsoo Kim wrote:
> We can disable debug_pagealloc processing even if the code is complied
> with CONFIG_DEBUG_PAGEALLOC. This patch changes the code to query
> whether it is enabled or not in runtime.
>
> Signed-off-by: Joonsoo Kim <[email protected]>
> ---
> mm/slub.c | 11 ++++++-----
> 1 file changed, 6 insertions(+), 5 deletions(-)
>
> diff --git a/mm/slub.c b/mm/slub.c
> index 7d4da68..7b5a965 100644
> --- a/mm/slub.c
> +++ b/mm/slub.c
> @@ -256,11 +256,12 @@ static inline void *get_freepointer_safe(struct
> kmem_cache *s, void *object)
> {
> void *p;
>
> -#ifdef CONFIG_DEBUG_PAGEALLOC
> - probe_kernel_read(&p, (void **)(object + s->offset), sizeof(p));
> -#else
> - p = get_freepointer(s, object);
> -#endif
> + if (debug_pagealloc_enabled()) {
> + probe_kernel_read(&p,
> + (void **)(object + s->offset), sizeof(p));
Hmm, this might be a good case for a line longer than 80 chars....
As an alternative revert the logic and return early:
if (!debug_pagealloc_enabled())
return get_freepointer(s, object);
probe_kernel_read(&p, (void **)(object + s->offset), sizeof(p));
return p;
?
> + } else
> + p = get_freepointer(s, object);
> +
> return p;
> }
>
