2020-11-16 06:04:56

by Lukas Bulwahn

Subject: [PATCH] mm: memcg: remove obsolete memcg_has_children()

Commit 2ef1bf118c40 ("mm: memcg: deprecate the non-hierarchical mode")
removed the only use of memcg_has_children() in
mem_cgroup_hierarchy_write() as part of the feature deprecation.

Hence, since then, make CC=clang W=1 warns:

mm/memcontrol.c:3421:20:
warning: unused function 'memcg_has_children' [-Wunused-function]

Simply remove this obsolete unused function.

Signed-off-by: Lukas Bulwahn <[email protected]>
---
applies cleanly on next-20201113, not on current master

Roman, please ack.

Andrew, please pick this minor non-urgent patch into your -next tree.

mm/memcontrol.c | 13 -------------
1 file changed, 13 deletions(-)

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index f95ddb3e9898..d49d7c507284 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -3415,19 +3415,6 @@ unsigned long mem_cgroup_soft_limit_reclaim(pg_data_t *pgdat, int order,
return nr_reclaimed;
}

-/*
- * Test whether @memcg has children, dead or alive.
- */
-static inline bool memcg_has_children(struct mem_cgroup *memcg)
-{
- bool ret;
-
- rcu_read_lock();
- ret = css_next_child(NULL, &memcg->css);
- rcu_read_unlock();
- return ret;
-}
-
/*
* Reclaims as many pages from the given memcg as possible.
*
--
2.17.1

2020-11-16 22:49:21

by Roman Gushchin

Subject: Re: [PATCH] mm: memcg: remove obsolete memcg_has_children()

On Mon, Nov 16, 2020 at 06:50:43AM +0100, Lukas Bulwahn wrote:
> Commit 2ef1bf118c40 ("mm: memcg: deprecate the non-hierarchical mode")
> removed the only use of memcg_has_children() in
> mem_cgroup_hierarchy_write() as part of the feature deprecation.
>
> Hence, since then, make CC=clang W=1 warns:
>
> mm/memcontrol.c:3421:20:
> warning: unused function 'memcg_has_children' [-Wunused-function]
>
> Simply remove this obsolete unused function.
>
> Signed-off-by: Lukas Bulwahn <[email protected]>
> ---
> applies cleanly on next-20201113, not on current master
>
> Roman, please ack.

Acked-by: Roman Gushchin <[email protected]>

Thanks!

2020-11-17 02:59:33

by Nathan Chancellor

Subject: Re: [PATCH] mm: memcg: remove obsolete memcg_has_children()

On Mon, Nov 16, 2020 at 06:50:43AM +0100, Lukas Bulwahn wrote:
> Commit 2ef1bf118c40 ("mm: memcg: deprecate the non-hierarchical mode")
> removed the only use of memcg_has_children() in
> mem_cgroup_hierarchy_write() as part of the feature deprecation.
>
> Hence, since then, make CC=clang W=1 warns:
>
> mm/memcontrol.c:3421:20:
> warning: unused function 'memcg_has_children' [-Wunused-function]
>
> Simply remove this obsolete unused function.
>
> Signed-off-by: Lukas Bulwahn <[email protected]>

Reviewed-by: Nathan Chancellor <[email protected]>

2020-11-18 12:50:58

by Michal Hocko

Subject: Re: [PATCH] mm: memcg: remove obsolete memcg_has_children()

On Mon 16-11-20 06:50:43, Lukas Bulwahn wrote:
> Commit 2ef1bf118c40 ("mm: memcg: deprecate the non-hierarchical mode")
> removed the only use of memcg_has_children() in
> mem_cgroup_hierarchy_write() as part of the feature deprecation.
>
> Hence, since then, make CC=clang W=1 warns:
>
> mm/memcontrol.c:3421:20:
> warning: unused function 'memcg_has_children' [-Wunused-function]
>
> Simply remove this obsolete unused function.
>
> Signed-off-by: Lukas Bulwahn <[email protected]>

git grep agrees
Acked-by: Michal Hocko <[email protected]>

> ---
> applies cleanly on next-20201113, not on current master
>
> Roman, please ack.
>
> Andrew, please pick this minor non-urgent patch into your -next tree.
>
> mm/memcontrol.c | 13 -------------
> 1 file changed, 13 deletions(-)
>
> diff --git a/mm/memcontrol.c b/mm/memcontrol.c
> index f95ddb3e9898..d49d7c507284 100644
> --- a/mm/memcontrol.c
> +++ b/mm/memcontrol.c
> @@ -3415,19 +3415,6 @@ unsigned long mem_cgroup_soft_limit_reclaim(pg_data_t *pgdat, int order,
> return nr_reclaimed;
> }
>
> -/*
> - * Test whether @memcg has children, dead or alive.
> - */
> -static inline bool memcg_has_children(struct mem_cgroup *memcg)
> -{
> - bool ret;
> -
> - rcu_read_lock();
> - ret = css_next_child(NULL, &memcg->css);
> - rcu_read_unlock();
> - return ret;
> -}
> -
> /*
> * Reclaims as many pages from the given memcg as possible.
> *
> --
> 2.17.1

--
Michal Hocko
SUSE Labs