diff options
| author | Li Zefan <lizf@cn.fujitsu.com> | 2010-04-23 04:35:52 +0200 |
|---|---|---|
| committer | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2010-05-04 18:25:02 +0200 |
| commit | 1ce7e4ff24fe338438bc7837e02780f202bf202b (patch) | |
| tree | 3906643ba96ba8b3fda2291e5e40e48bbba9085f | |
| parent | sched: Fix an RCU warning in print_task() (diff) | |
| download | linux-1ce7e4ff24fe338438bc7837e02780f202bf202b.tar.xz linux-1ce7e4ff24fe338438bc7837e02780f202bf202b.zip | |
cgroup: Check task_lock in task_subsys_state()
Expand task_subsys_state()'s rcu_dereference_check() to include the full
locking rule as documented in Documentation/cgroups/cgroups.txt by adding
a check for task->alloc_lock being held.
This fixes an RCU false positive when resuming from suspend. The warning
comes from freezer cgroup in cgroup_freezing_or_frozen().
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Acked-by: Matt Helsley <matthltc@us.ibm.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
| -rw-r--r-- | include/linux/cgroup.h | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h index b8ad1ea99586..8f78073d7caa 100644 --- a/include/linux/cgroup.h +++ b/include/linux/cgroup.h @@ -530,6 +530,7 @@ static inline struct cgroup_subsys_state *task_subsys_state( { return rcu_dereference_check(task->cgroups->subsys[subsys_id], rcu_read_lock_held() || + lockdep_is_held(&task->alloc_lock) || cgroup_lock_is_held()); } |