On Wed, Oct 28, 2020 at 10:17 PM Hui Su <sh_...@163.com> wrote:
>
> In list_lru_walk(), nr_to_walk type is 'unsigned long',
> so nr_to_walk won't be '< 0'.
>
> In list_lru_walk_node(), nr_to_walk type is 'unsigned long',
> so *nr_to_walk won't be '< 0' too.
>
> We can use '!nr_to_walk' instead of 'nr_to_walk <= 0', which
> is more precise.
>
> Signed-off-by: Hui Su <sh_...@163.com>
Reviewed-by: Muchun Song <songmuc...@bytedance.com>
> ---
> include/linux/list_lru.h | 2 +-
> mm/list_lru.c | 4 ++--
> 2 files changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/include/linux/list_lru.h b/include/linux/list_lru.h
> index 9dcaa3e582c9..b7bc4a2636b9 100644
> --- a/include/linux/list_lru.h
> +++ b/include/linux/list_lru.h
> @@ -214,7 +214,7 @@ list_lru_walk(struct list_lru *lru, list_lru_walk_cb
> isolate,
> for_each_node_state(nid, N_NORMAL_MEMORY) {
> isolated += list_lru_walk_node(lru, nid, isolate,
> cb_arg, &nr_to_walk);
> - if (nr_to_walk <= 0)
> + if (!nr_to_walk)
> break;
> }
> return isolated;
> diff --git a/mm/list_lru.c b/mm/list_lru.c
> index 5aa6e44bc2ae..35be4de9fd77 100644
> --- a/mm/list_lru.c
> +++ b/mm/list_lru.c
> @@ -294,7 +294,7 @@ unsigned long list_lru_walk_node(struct list_lru *lru,
> int nid,
>
> isolated += list_lru_walk_one(lru, nid, NULL, isolate, cb_arg,
> nr_to_walk);
> - if (*nr_to_walk > 0 && list_lru_memcg_aware(lru)) {
> + if (*nr_to_walk && list_lru_memcg_aware(lru)) {
> for_each_memcg_cache_index(memcg_idx) {
> struct list_lru_node *nlru = &lru->node[nid];
>
> @@ -304,7 +304,7 @@ unsigned long list_lru_walk_node(struct list_lru *lru,
> int nid,
> nr_to_walk);
> spin_unlock(&nlru->lock);
>
> - if (*nr_to_walk <= 0)
> + if (!*nr_to_walk)
> break;
> }
> }
> --
> 2.29.0
>
>
--
Yours,
Muchun
