Messages in this thread Patch in this message | | | Date | Fri, 23 Apr 2010 10:35:52 +0800 | From | Li Zefan <> | Subject | [PATCH] cgroup: Check task_lock in task_subsys_state() |
| |
task_subsys_state() is safe under task_lock(). See Documentation/cgroups/cgroups.txt for locking rule.
This fixes an RCU warning when resume from suspend. The warning comes from freezer cgroup in cgroup_freezing_or_frozen().
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> ---
I'm not sure which is preferable - access ->alloc_lock directly like this patch or add task_lock_is_held() in sched.h
--- 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 b8ad1ea..8f78073 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()); } -- 1.6.3
| |