memcg: add CONFIG_MEMCG_V1 for 'local' functions

Add CONFIG_MEMCG_V1 for the 'local' functions, which are only used in
memcg v1, so that they won't be built for v2.

Link: https://lkml.kernel.org/r/20250124073514.2375622-5-chenridong@huaweicloud.com
Signed-off-by: Chen Ridong <chenridong@huawei.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
Acked-by: Roman Gushchin <roman.gushchin@linux.dev>
Cc: David Finkel <davidf@vimeo.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Wang Weiyang <wangweiyang2@huawei.com>
Cc: Yosry Ahmed <yosryahmed@google.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Michal Koutný <mkoutny@suse.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Author: Chen Ridong

mm/memcontrol-v1.h

@@ -60,15 +60,15 @@ unsigned long mem_cgroup_usage(struct mem_cgroup *memcg, bool swap);
 void drain_all_stock(struct mem_cgroup *root_memcg);
 
 unsigned long memcg_events(struct mem_cgroup *memcg, int event);
-unsigned long memcg_events_local(struct mem_cgroup *memcg, int event);
-unsigned long memcg_page_state_local(struct mem_cgroup *memcg, int idx);
 unsigned long memcg_page_state_output(struct mem_cgroup *memcg, int item);
-unsigned long memcg_page_state_local_output(struct mem_cgroup *memcg, int item);
 int memory_stat_show(struct seq_file *m, void *v);
 
 /* Cgroup v1-specific declarations */
 #ifdef CONFIG_MEMCG_V1
 
+unsigned long memcg_events_local(struct mem_cgroup *memcg, int event);
+unsigned long memcg_page_state_local(struct mem_cgroup *memcg, int idx);
+unsigned long memcg_page_state_local_output(struct mem_cgroup *memcg, int item);
 bool memcg1_alloc_events(struct mem_cgroup *memcg);
 void memcg1_free_events(struct mem_cgroup *memcg);
 

mm/memcontrol.c

@@ -706,6 +706,7 @@ void __mod_memcg_state(struct mem_cgroup *memcg, enum memcg_stat_item idx,
 	trace_mod_memcg_state(memcg, idx, val);
 }
 
+#ifdef CONFIG_MEMCG_V1
 /* idx can be of type enum memcg_stat_item or node_stat_item. */
 unsigned long memcg_page_state_local(struct mem_cgroup *memcg, int idx)
 {
@@ -722,6 +723,7 @@ unsigned long memcg_page_state_local(struct mem_cgroup *memcg, int idx)
 #endif
 	return x;
 }
+#endif
 
 static void __mod_memcg_lruvec_state(struct lruvec *lruvec,
 				     enum node_stat_item idx,
@@ -869,6 +871,7 @@ unsigned long memcg_events(struct mem_cgroup *memcg, int event)
 	return READ_ONCE(memcg->vmstats->events[i]);
 }
 
+#ifdef CONFIG_MEMCG_V1
 unsigned long memcg_events_local(struct mem_cgroup *memcg, int event)
 {
 	int i = memcg_events_index(event);
@@ -878,6 +881,7 @@ unsigned long memcg_events_local(struct mem_cgroup *memcg, int event)
 
 	return READ_ONCE(memcg->vmstats->events_local[i]);
 }
+#endif
 
 struct mem_cgroup *mem_cgroup_from_task(struct task_struct *p)
 {
@@ -1447,11 +1451,13 @@ unsigned long memcg_page_state_output(struct mem_cgroup *memcg, int item)
 		memcg_page_state_output_unit(item);
 }
 
+#ifdef CONFIG_MEMCG_V1
 unsigned long memcg_page_state_local_output(struct mem_cgroup *memcg, int item)
 {
 	return memcg_page_state_local(memcg, item) *
 		memcg_page_state_output_unit(item);
 }
+#endif
 
 #ifdef CONFIG_HUGETLB_PAGE
 static bool memcg_accounts_hugetlb(void)