2020-05-28 09:59:22

by Arnd Bergmann

Subject: [PATCH] mm: memcontrol: fix an unused-function warning

On NOMMU kernels without CONFIG_MEMCG_KMEM, we now get a harmless
warning about an unused function:

mm/memcontrol.c:2595:13: error: unused function 'cancel_charge' [-Werror,-Wunused-function]

Hide this function in a matching #ifdef.

Fixes: 5bd144bf764c ("mm: memcontrol: drop unused try/commit/cancel charge API")
Signed-off-by: Arnd Bergmann <[email protected]>
---
mm/memcontrol.c | 2 ++
1 file changed, 2 insertions(+)

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index f14da7a7348b..7bfca0abb8e1 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -2592,6 +2592,7 @@ static int try_charge(struct mem_cgroup *memcg, gfp_t gfp_mask,
return 0;
}

+#if defined(CONFIG_MEMCG_KMEM) || defined(CONFIG_MMU)
static void cancel_charge(struct mem_cgroup *memcg, unsigned int nr_pages)
{
if (mem_cgroup_is_root(memcg))
@@ -2603,6 +2604,7 @@ static void cancel_charge(struct mem_cgroup *memcg, unsigned int nr_pages)

css_put_many(&memcg->css, nr_pages);
}
+#endif

static void commit_charge(struct page *page, struct mem_cgroup *memcg)
{
--
2.26.2

2020-05-28 17:18:50

by Johannes Weiner

Subject: Re: [PATCH] mm: memcontrol: fix an unused-function warning

On Thu, May 28, 2020 at 11:56:26AM +0200, Arnd Bergmann wrote:
> On NOMMU kernels without CONFIG_MEMCG_KMEM, we now get a harmless
> warning about an unused function:
>
> mm/memcontrol.c:2595:13: error: unused function 'cancel_charge' [-Werror,-Wunused-function]
>
> Hide this function in a matching #ifdef.
>
> Fixes: 5bd144bf764c ("mm: memcontrol: drop unused try/commit/cancel charge API")
> Signed-off-by: Arnd Bergmann <[email protected]>

Acked-by: Johannes Weiner <[email protected]>

Thanks Arnd!

2020-05-29 08:21:38

by Michal Hocko

Subject: Re: [PATCH] mm: memcontrol: fix an unused-function warning

On Thu 28-05-20 11:56:26, Arnd Bergmann wrote:
> On NOMMU kernels without CONFIG_MEMCG_KMEM, we now get a harmless
> warning about an unused function:
>
> mm/memcontrol.c:2595:13: error: unused function 'cancel_charge' [-Werror,-Wunused-function]
>
> Hide this function in a matching #ifdef.
>
> Fixes: 5bd144bf764c ("mm: memcontrol: drop unused try/commit/cancel charge API")

This is a linux-next sha1 which is not valid anymore. I would just drop
the tag.

> Signed-off-by: Arnd Bergmann <[email protected]>

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

Thanks!
> ---
> mm/memcontrol.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/mm/memcontrol.c b/mm/memcontrol.c
> index f14da7a7348b..7bfca0abb8e1 100644
> --- a/mm/memcontrol.c
> +++ b/mm/memcontrol.c
> @@ -2592,6 +2592,7 @@ static int try_charge(struct mem_cgroup *memcg, gfp_t gfp_mask,
> return 0;
> }
>
> +#if defined(CONFIG_MEMCG_KMEM) || defined(CONFIG_MMU)
> static void cancel_charge(struct mem_cgroup *memcg, unsigned int nr_pages)
> {
> if (mem_cgroup_is_root(memcg))
> @@ -2603,6 +2604,7 @@ static void cancel_charge(struct mem_cgroup *memcg, unsigned int nr_pages)
>
> css_put_many(&memcg->css, nr_pages);
> }
> +#endif
>
> static void commit_charge(struct page *page, struct mem_cgroup *memcg)
> {
> --
> 2.26.2
>

--
Michal Hocko
SUSE Labs