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| author | Sha Zhengju <handai.szj@taobao.com> | 2013-09-12 15:13:52 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2013-09-12 15:38:02 -0700 |
| commit | 658b72c5a7a033f0dde61b15dff86bf423ce425e (patch) | |
| tree | 271352bf3a3c5ad13acca1ca425dfb8b53d1e190 /mm/memcontrol.c | |
| parent | 68b4876d996e8749142b2895bc2e251448996363 (diff) | |
| download | lwn-658b72c5a7a033f0dde61b15dff86bf423ce425e.tar.gz lwn-658b72c5a7a033f0dde61b15dff86bf423ce425e.zip | |
memcg: check for proper lock held in mem_cgroup_update_page_stat
We should call mem_cgroup_begin_update_page_stat() before
mem_cgroup_update_page_stat() to get proper locks, however the latter
doesn't do any checking that we use proper locking, which would be hard.
Suggested by Michal Hock we could at least test for rcu_read_lock_held()
because RCU is held if !mem_cgroup_disabled().
Signed-off-by: Sha Zhengju <handai.szj@taobao.com>
Acked-by: Michal Hocko <mhocko@suse.cz>
Reviewed-by: Greg Thelen <gthelen@google.com>
Cc: Fengguang Wu <fengguang.wu@intel.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/memcontrol.c')
| -rw-r--r-- | mm/memcontrol.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/mm/memcontrol.c b/mm/memcontrol.c index f3803462a7e6..0093bc36c5fc 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -2225,6 +2225,7 @@ void mem_cgroup_update_page_stat(struct page *page, if (mem_cgroup_disabled()) return; + VM_BUG_ON(!rcu_read_lock_held()); memcg = pc->mem_cgroup; if (unlikely(!memcg || !PageCgroupUsed(pc))) return; |