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 <arnd@xxxxxxxx> --- 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