mm: memcg: add reminder comment for the memcg v2 events

To maintain the correct state, it is important to ensure that events for
the memory cgroup v2 are aligned with the sample cgroup codes.

Link: https://lkml.kernel.org/r/20231123071945.25811-4-ddrokosov@salutedevices.com
Signed-off-by: Dmitry Rokosov <ddrokosov@salutedevices.com>
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: Shakeel Butt <shakeelb@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index b226090fd9061c6261ace5a09850ebcc0c183060..592572d4842e2116e1aef10d6374a2dc66af35ff 100644 (file)
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -6783,6 +6783,10 @@ static ssize_t memory_max_write(struct kernfs_open_file *of,
        return nbytes;
 }
 
+/*
+ * Note: don't forget to update the 'samples/cgroup/memcg_event_listener'
+ * if any new events become available.
+ */
 static void __memory_events_show(struct seq_file *m, atomic_long_t *events)
 {
        seq_printf(m, "low %lu\n", atomic_long_read(&events[MEMCG_LOW]));