memcg: free spare array to avoid memory leak
When the last event is unregistered, there is no need to keep the spare
array anymore. So free it to avoid memory leak.
Signed-off-by: Sha Zhengju <handai.szj@taobao.com>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Reviewed-by: Kirill A. Shutemov <kirill@shutemov.name>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 31ab9c3..b659260 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -4507,6 +4507,12 @@
swap_buffers:
/* Swap primary and spare array */
thresholds->spare = thresholds->primary;
+ /* If all events are unregistered, free the spare array */
+ if (!new) {
+ kfree(thresholds->spare);
+ thresholds->spare = NULL;
+ }
+
rcu_assign_pointer(thresholds->primary, new);
/* To be sure that nobody uses thresholds */