Re: [PATCH] mm/slub: avoid double string traverse in kmem_cache_flags()

From: Aaron Tomlin
Date: Tue May 14 2019 - 08:23:46 EST


On Tue 2019-04-30 22:31 -0700, Yury Norov wrote:
> If ',' is not found, kmem_cache_flags() calls strlen() to find the end
> of line. We can do it in a single pass using strchrnul().
>
> Signed-off-by: Yury Norov <ynorov@xxxxxxxxxxx>
> ---
> mm/slub.c | 4 +---
> 1 file changed, 1 insertion(+), 3 deletions(-)
>
> diff --git a/mm/slub.c b/mm/slub.c
> index 4922a0394757..85f90370a293 100644
> --- a/mm/slub.c
> +++ b/mm/slub.c
> @@ -1317,9 +1317,7 @@ slab_flags_t kmem_cache_flags(unsigned int object_size,
> char *end, *glob;
> size_t cmplen;
>
> - end = strchr(iter, ',');
> - if (!end)
> - end = iter + strlen(iter);
> + end = strchrnul(iter, ',');
>
> glob = strnchr(iter, end - iter, '*');
> if (glob)

Fair enough.

Acked-by: Aaron Tomlin <atomlin@xxxxxxxxxx>

--
Aaron Tomlin