Re: [PATCH] cgroup.c: Use built-in RCU list checking

From: Tejun Heo
Date: Wed Feb 12 2020 - 17:12:53 EST


On Sat, Jan 18, 2020 at 08:40:51AM +0530, madhuparnabhowmik10@xxxxxxxxx wrote:
> From: Madhuparna Bhowmik <madhuparnabhowmik10@xxxxxxxxx>
>
> list_for_each_entry_rcu has built-in RCU and lock checking.
> Pass cond argument to list_for_each_entry_rcu() to silence
> false lockdep warning when CONFIG_PROVE_RCU_LIST is enabled
> by default.
>
> Even though the function css_next_child() already checks if
> cgroup_mutex or rcu_read_lock() is held using
> cgroup_assert_mutex_or_rcu_locked(), there is a need to pass
> cond to list_for_each_entry_rcu() to avoid false positive
> lockdep warning.
>
> Signed-off-by: Madhuparna Bhowmik <madhuparnabhowmik10@xxxxxxxxx>

Applied to cgroup/for-5.7.

Thanks.

--
tejun