[PATCH] fixup: vmscan: Fix build on !CONFIG_MEMCG from nr_deactivate changes

[PATCH] fixup: vmscan: Fix build on !CONFIG_MEMCG from nr_deactivate changes

[Chris Down]

"mm: move nr_deactivate accounting to shrink_active_list()" uses the
non-irqsaved version of count_memcg_events (__count_memcg_events), but
we've only exported the irqsaving version of it to userspace, so the
build breaks:

    mm/vmscan.c: In function ‘shrink_active_list’:
    mm/vmscan.c:2101:2: error: implicit declaration of function ‘__count_memcg_events’; did you mean ‘count_memcg_events’? [-Werror=implicit-function-declaration]

This fixup makes it build with !CONFIG_MEMCG.

Signed-off-by: Chris Down <chris@chrisdown.name>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Kirill Tkhai <ktkhai@virtuozzo.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: linux-kernel@vger.kernel.org
Cc: cgroups@vger.kernel.org
Cc: linux-mm@kvack.org
Cc: kernel-team@fb.com
---
 include/linux/memcontrol.h | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
index 534267947664..b226c4bafc93 100644
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h
@@ -1147,6 +1147,12 @@ static inline void count_memcg_events(struct mem_cgroup *memcg,
 {
 }
 
+static inline void __count_memcg_events(struct mem_cgroup *memcg,
+					enum vm_event_item idx,
+					unsigned long count)
+{
+}
+
 static inline void count_memcg_page_event(struct page *page,
 					  int idx)
 {
-- 
2.21.0

Re: [PATCH] fixup: vmscan: Fix build on !CONFIG_MEMCG from nr_deactivate changes

[Chris Down]

Chris Down writes:
>"mm: move nr_deactivate accounting to shrink_active_list()" uses the
>non-irqsaved version of count_memcg_events (__count_memcg_events), but
>we've only exported the irqsaving version of it to userspace, so the
>build breaks:

Er, "with !CONFIG_MEMCG", not "to userspace". No idea where that came from...

Re: [PATCH] fixup: vmscan: Fix build on !CONFIG_MEMCG from nr_deactivate changes

[Kirill Tkhai]

On 22.03.2019 18:05, Chris Down wrote:
> "mm: move nr_deactivate accounting to shrink_active_list()" uses the
> non-irqsaved version of count_memcg_events (__count_memcg_events), but
> we've only exported the irqsaving version of it to userspace, so the
> build breaks:
> 
>     mm/vmscan.c: In function ‘shrink_active_list’:
>     mm/vmscan.c:2101:2: error: implicit declaration of function ‘__count_memcg_events’; did you mean ‘count_memcg_events’? [-Werror=implicit-function-declaration]
> 
> This fixup makes it build with !CONFIG_MEMCG.

Yeah, thanks, Chris.

> Signed-off-by: Chris Down <chris@chrisdown.name>
> Cc: Andrew Morton <akpm@linux-foundation.org>
> Cc: Kirill Tkhai <ktkhai@virtuozzo.com>
> Cc: Johannes Weiner <hannes@cmpxchg.org>
> Cc: Tejun Heo <tj@kernel.org>
> Cc: linux-kernel@vger.kernel.org
> Cc: cgroups@vger.kernel.org
> Cc: linux-mm@kvack.org
> Cc: kernel-team@fb.com
> ---
>  include/linux/memcontrol.h | 6 ++++++
>  1 file changed, 6 insertions(+)
> 
> diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
> index 534267947664..b226c4bafc93 100644
> --- a/include/linux/memcontrol.h
> +++ b/include/linux/memcontrol.h
> @@ -1147,6 +1147,12 @@ static inline void count_memcg_events(struct mem_cgroup *memcg,
>  {
>  }
>  
> +static inline void __count_memcg_events(struct mem_cgroup *memcg,
> +					enum vm_event_item idx,
> +					unsigned long count)
> +{
> +}
> +
>  static inline void count_memcg_page_event(struct page *page,
>  					  int idx)
>  {
>