From: Vincenzo Frascino <vincenzo.frascino@xxxxxxx> Subject: mm/memcontrol.c: make mem_cgroup_id_get_many() __maybe_unused mem_cgroup_id_get_many() is currently used only when MMU or MEMCG_SWAP configuration options are enabled. Having them disabled triggers the following warning at compile time: linux/mm/memcontrol.c:4797:13: warning: `mem_cgroup_id_get_many' defined but not used [-Wunused-function] static void mem_cgroup_id_get_many(struct mem_cgroup *memcg, unsigned int n) Make mem_cgroup_id_get_many() __maybe_unused to address the issue. Link: http://lkml.kernel.org/r/20200305164354.48147-1-vincenzo.frascino@xxxxxxx Signed-off-by: Vincenzo Frascino <vincenzo.frascino@xxxxxxx> Acked-by: Johannes Weiner <hannes@xxxxxxxxxxx> Acked-by: Chris Down <chris@xxxxxxxxxxxxxx> Cc: Michal Hocko <mhocko@xxxxxxxxxx> Cc: Vladimir Davydov <vdavydov.dev@xxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/memcontrol.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/mm/memcontrol.c~mm-make-mem_cgroup_id_get_many-__maybe_unused +++ a/mm/memcontrol.c @@ -4863,7 +4863,8 @@ static void mem_cgroup_id_remove(struct } } -static void mem_cgroup_id_get_many(struct mem_cgroup *memcg, unsigned int n) +static void __maybe_unused mem_cgroup_id_get_many(struct mem_cgroup *memcg, + unsigned int n) { refcount_add(n, &memcg->id.ref); } _