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>
This commit is contained in:
Sha Zhengju 2012-05-10 13:01:45 -07:00 committed by Linus Torvalds
parent 5e2bf01422
commit 8c7577637c
1 changed files with 6 additions and 0 deletions

View File

@ -4507,6 +4507,12 @@ static void mem_cgroup_usage_unregister_event(struct cgroup *cgrp,
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 */