memcg: move mem_cgroup_charge_statistics to v1 code

There are no callers of mem_cgroup_charge_statistics() in the v2 code
base, so move it to the v1 only code and rename it to
memcg1_charge_statistics().

Link: https://lkml.kernel.org/r/20240815050453.1298138-4-shakeel.butt@linux.devSigned-off-by: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: T.J. Mercier <tjmercier@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

mm/memcontrol-v1.c

@@ -853,9 +853,9 @@ static int mem_cgroup_move_account(struct folio *folio,
 	nid = folio_nid(folio);
 
 	local_irq_disable();
-	mem_cgroup_charge_statistics(to, nr_pages);
+	memcg1_charge_statistics(to, nr_pages);
 	memcg1_check_events(to, nid);
-	mem_cgroup_charge_statistics(from, -nr_pages);
+	memcg1_charge_statistics(from, -nr_pages);
 	memcg1_check_events(from, nid);
 	local_irq_enable();
 out:
@@ -1439,6 +1439,19 @@ static void mem_cgroup_threshold(struct mem_cgroup *memcg)
 	}
 }
 
+void memcg1_charge_statistics(struct mem_cgroup *memcg, int nr_pages)
+{
+	/* pagein of a big page is an event. So, ignore page size */
+	if (nr_pages > 0)
+		__count_memcg_events(memcg, PGPGIN, 1);
+	else {
+		__count_memcg_events(memcg, PGPGOUT, 1);
+		nr_pages = -nr_pages; /* for event */
+	}
+
+	__this_cpu_add(memcg->events_percpu->nr_page_events, nr_pages);
+}
+
 #define THRESHOLDS_EVENTS_TARGET 128
 #define SOFTLIMIT_EVENTS_TARGET 1024
 

mm/memcontrol-v1.h

@@ -7,7 +7,6 @@
 
 /* Cgroup v1 and v2 common declarations */
 
-void mem_cgroup_charge_statistics(struct mem_cgroup *memcg, int nr_pages);
 int try_charge_memcg(struct mem_cgroup *memcg, gfp_t gfp_mask,
 		     unsigned int nr_pages);
 
@@ -116,6 +115,7 @@ bool memcg1_oom_prepare(struct mem_cgroup *memcg, bool *locked);
 void memcg1_oom_finish(struct mem_cgroup *memcg, bool locked);
 void memcg1_oom_recover(struct mem_cgroup *memcg);
 
+void memcg1_charge_statistics(struct mem_cgroup *memcg, int nr_pages);
 void memcg1_check_events(struct mem_cgroup *memcg, int nid);
 
 void memcg1_stat_format(struct mem_cgroup *memcg, struct seq_buf *s);
@@ -147,6 +147,7 @@ static inline bool memcg1_oom_prepare(struct mem_cgroup *memcg, bool *locked) {
 static inline void memcg1_oom_finish(struct mem_cgroup *memcg, bool locked) {}
 static inline void memcg1_oom_recover(struct mem_cgroup *memcg) {}
 
+static inline void memcg1_charge_statistics(struct mem_cgroup *memcg, int nr_pages) {}
 static inline void memcg1_check_events(struct mem_cgroup *memcg, int nid) {}
 
 static inline void memcg1_stat_format(struct mem_cgroup *memcg, struct seq_buf *s) {}

mm/memcontrol.c

@@ -840,19 +840,6 @@ unsigned long memcg_events_local(struct mem_cgroup *memcg, int event)
 	return READ_ONCE(memcg->vmstats->events_local[i]);
 }
 
-void mem_cgroup_charge_statistics(struct mem_cgroup *memcg, int nr_pages)
-{
-	/* pagein of a big page is an event. So, ignore page size */
-	if (nr_pages > 0)
-		__count_memcg_events(memcg, PGPGIN, 1);
-	else {
-		__count_memcg_events(memcg, PGPGOUT, 1);
-		nr_pages = -nr_pages; /* for event */
-	}
-
-	__this_cpu_add(memcg->events_percpu->nr_page_events, nr_pages);
-}
-
 struct mem_cgroup *mem_cgroup_from_task(struct task_struct *p)
 {
 	/*
@@ -2366,7 +2353,7 @@ void mem_cgroup_commit_charge(struct folio *folio, struct mem_cgroup *memcg)
 	commit_charge(folio, memcg);
 
 	local_irq_disable();
-	mem_cgroup_charge_statistics(memcg, folio_nr_pages(folio));
+	memcg1_charge_statistics(memcg, folio_nr_pages(folio));
 	memcg1_check_events(memcg, folio_nid(folio));
 	local_irq_enable();
 }
@@ -4742,7 +4729,7 @@ void mem_cgroup_replace_folio(struct folio *old, struct folio *new)
 	commit_charge(new, memcg);
 
 	local_irq_save(flags);
-	mem_cgroup_charge_statistics(memcg, nr_pages);
+	memcg1_charge_statistics(memcg, nr_pages);
 	memcg1_check_events(memcg, folio_nid(new));
 	local_irq_restore(flags);
 }
@@ -4987,7 +4974,7 @@ void mem_cgroup_swapout(struct folio *folio, swp_entry_t entry)
 	 * only synchronisation we have for updating the per-CPU variables.
 	 */
 	memcg_stats_lock();
-	mem_cgroup_charge_statistics(memcg, -nr_entries);
+	memcg1_charge_statistics(memcg, -nr_entries);
 	memcg_stats_unlock();
 	memcg1_check_events(memcg, folio_nid(folio));