diff options
| author | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2010-04-21 13:02:08 -0700 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2010-04-30 12:03:17 +0200 |
| commit | 8b46f880841aac821af8efa6581bb0e46b8b9845 (patch) | |
| tree | 4172415abf0f8cbbdd7367023cf521e7a56b9a3a /kernel | |
| parent | 8b08ca52f5942c21564bbb90ccfb61053f2c26a1 (diff) | |
| download | lwn-8b46f880841aac821af8efa6581bb0e46b8b9845.tar.gz lwn-8b46f880841aac821af8efa6581bb0e46b8b9845.zip | |
rcu: Fix RCU lockdep splat on freezer_fork path
Add an RCU read-side critical section to suppress this false
positive.
Located-by: Eric Paris <eparis@parisplace.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: Li Zefan <lizf@cn.fujitsu.com>
Cc: laijs@cn.fujitsu.com
Cc: dipankar@in.ibm.com
Cc: mathieu.desnoyers@polymtl.ca
Cc: josh@joshtriplett.org
Cc: dvhltc@us.ibm.com
Cc: niv@us.ibm.com
Cc: peterz@infradead.org
Cc: rostedt@goodmis.org
Cc: Valdis.Kletnieks@vt.edu
Cc: dhowells@redhat.com
Cc: eric.dumazet@gmail.com
LKML-Reference: <1271880131-3951-2-git-send-email-paulmck@linux.vnet.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/cgroup_freezer.c | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/kernel/cgroup_freezer.c b/kernel/cgroup_freezer.c index da5e13975531..e5c0244962b0 100644 --- a/kernel/cgroup_freezer.c +++ b/kernel/cgroup_freezer.c @@ -205,9 +205,12 @@ static void freezer_fork(struct cgroup_subsys *ss, struct task_struct *task) * No lock is needed, since the task isn't on tasklist yet, * so it can't be moved to another cgroup, which means the * freezer won't be removed and will be valid during this - * function call. + * function call. Nevertheless, apply RCU read-side critical + * section to suppress RCU lockdep false positives. */ + rcu_read_lock(); freezer = task_freezer(task); + rcu_read_unlock(); /* * The root cgroup is non-freezable, so we can skip the |