[PATCH] memcg, kmem: mark cancel_charge() inline

[PATCH] memcg, kmem: mark cancel_charge() inline

[Arnd Bergmann]

From: Arnd Bergmann <arnd@arndb.de>

cancel_charge() is no longer called for CONFIG_MEMCG_KMEM on NOMMU
targets, which causes a compiletime warning:

mm/memcontrol.c:2774:13: error: unused function 'cancel_charge' [-Werror,-Wunused-function]

Remove the now-incorrect #ifdef and just mark the function
'inline' like the other related helpers. This is simpler
and means we no longer have to match the #ifdef with the
caller.

Fixes: 5f3345c17079 ("memcg, kmem: further deprecate kmem.limit_in_bytes")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
The 5f3345c17079 commit is in -mm, so the commit ID is not
stable. Feel free to just fold this into the other patch, or
take out that reference
---
 mm/memcontrol.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 6538595994d2..9edccfeac804 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -2770,8 +2770,7 @@ static inline int try_charge(struct mem_cgroup *memcg, gfp_t gfp_mask,
 	return try_charge_memcg(memcg, gfp_mask, nr_pages);
 }
 
-#if defined(CONFIG_MEMCG_KMEM) || defined(CONFIG_MMU)
-static void cancel_charge(struct mem_cgroup *memcg, unsigned int nr_pages)
+static inline void cancel_charge(struct mem_cgroup *memcg, unsigned int nr_pages)
 {
 	if (mem_cgroup_is_root(memcg))
 		return;
@@ -2780,7 +2779,6 @@ static void cancel_charge(struct mem_cgroup *memcg, unsigned int nr_pages)
 	if (do_memsw_account())
 		page_counter_uncharge(&memcg->memsw, nr_pages);
 }
-#endif
 
 static void commit_charge(struct folio *folio, struct mem_cgroup *memcg)
 {
-- 
2.29.2

Re: [PATCH] memcg, kmem: mark cancel_charge() inline

[Muchun Song]

On Fri, Oct 22, 2021 at 3:05 PM Arnd Bergmann <arnd@kernel.org> wrote:
>
> From: Arnd Bergmann <arnd@arndb.de>
>
> cancel_charge() is no longer called for CONFIG_MEMCG_KMEM on NOMMU
> targets, which causes a compiletime warning:
>
> mm/memcontrol.c:2774:13: error: unused function 'cancel_charge' [-Werror,-Wunused-function]
>
> Remove the now-incorrect #ifdef and just mark the function
> 'inline' like the other related helpers. This is simpler
> and means we no longer have to match the #ifdef with the
> caller.
>
> Fixes: 5f3345c17079 ("memcg, kmem: further deprecate kmem.limit_in_bytes")
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>

Thanks. I guess this should be squashed into the commit 5f3345c17079
("memcg, kmem: further deprecate kmem.limit_in_bytes").

Reviewed-by: Muchun Song <songmuchun@bytedance.com>

> ---
> The 5f3345c17079 commit is in -mm, so the commit ID is not
> stable. Feel free to just fold this into the other patch, or
> take out that reference
> ---
>  mm/memcontrol.c | 4 +---
>  1 file changed, 1 insertion(+), 3 deletions(-)
>
> diff --git a/mm/memcontrol.c b/mm/memcontrol.c
> index 6538595994d2..9edccfeac804 100644
> --- a/mm/memcontrol.c
> +++ b/mm/memcontrol.c
> @@ -2770,8 +2770,7 @@ static inline int try_charge(struct mem_cgroup *memcg, gfp_t gfp_mask,
>         return try_charge_memcg(memcg, gfp_mask, nr_pages);
>  }
>
> -#if defined(CONFIG_MEMCG_KMEM) || defined(CONFIG_MMU)
> -static void cancel_charge(struct mem_cgroup *memcg, unsigned int nr_pages)
> +static inline void cancel_charge(struct mem_cgroup *memcg, unsigned int nr_pages)
>  {
>         if (mem_cgroup_is_root(memcg))
>                 return;
> @@ -2780,7 +2779,6 @@ static void cancel_charge(struct mem_cgroup *memcg, unsigned int nr_pages)
>         if (do_memsw_account())
>                 page_counter_uncharge(&memcg->memsw, nr_pages);
>  }
> -#endif
>
>  static void commit_charge(struct folio *folio, struct mem_cgroup *memcg)
>  {
> --
> 2.29.2
>

Re: [PATCH] memcg, kmem: mark cancel_charge() inline

[Stephen Rothwell]

[-- Attachment #1: Type: text/plain, Size: 1886 bytes --]

Hi all,

On Fri, 22 Oct 2021 09:05:35 +0200 Arnd Bergmann <arnd@kernel.org> wrote:
>
> From: Arnd Bergmann <arnd@arndb.de>
> 
> cancel_charge() is no longer called for CONFIG_MEMCG_KMEM on NOMMU
> targets, which causes a compiletime warning:
> 
> mm/memcontrol.c:2774:13: error: unused function 'cancel_charge' [-Werror,-Wunused-function]
> 
> Remove the now-incorrect #ifdef and just mark the function
> 'inline' like the other related helpers. This is simpler
> and means we no longer have to match the #ifdef with the
> caller.
> 
> Fixes: 5f3345c17079 ("memcg, kmem: further deprecate kmem.limit_in_bytes")
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
> ---
> The 5f3345c17079 commit is in -mm, so the commit ID is not
> stable. Feel free to just fold this into the other patch, or
> take out that reference
> ---
>  mm/memcontrol.c | 4 +---
>  1 file changed, 1 insertion(+), 3 deletions(-)
> 
> diff --git a/mm/memcontrol.c b/mm/memcontrol.c
> index 6538595994d2..9edccfeac804 100644
> --- a/mm/memcontrol.c
> +++ b/mm/memcontrol.c
> @@ -2770,8 +2770,7 @@ static inline int try_charge(struct mem_cgroup *memcg, gfp_t gfp_mask,
>  	return try_charge_memcg(memcg, gfp_mask, nr_pages);
>  }
>  
> -#if defined(CONFIG_MEMCG_KMEM) || defined(CONFIG_MMU)
> -static void cancel_charge(struct mem_cgroup *memcg, unsigned int nr_pages)
> +static inline void cancel_charge(struct mem_cgroup *memcg, unsigned int nr_pages)
>  {
>  	if (mem_cgroup_is_root(memcg))
>  		return;
> @@ -2780,7 +2779,6 @@ static void cancel_charge(struct mem_cgroup *memcg, unsigned int nr_pages)
>  	if (do_memsw_account())
>  		page_counter_uncharge(&memcg->memsw, nr_pages);
>  }
> -#endif
>  
>  static void commit_charge(struct folio *folio, struct mem_cgroup *memcg)
>  {
> -- 
> 2.29.2
> 

Added to linux-next today.

-- 
Cheers,
Stephen Rothwell

[-- Attachment #2: OpenPGP digital signature --]
[-- Type: application/pgp-signature, Size: 488 bytes --]