[PATCH v3 08/14] cgroup: Remove redundant rcu_read_lock/unlock() in spin_lock

[Tejun Heo]

On Tue, Sep 16, 2025 at 12:47:29PM +0800, pengdonglin wrote:
> From: pengdonglin <pengdonglin at xiaomi.com>
> 
> Since commit a8bb74acd8efe ("rcu: Consolidate RCU-sched update-side function definitions")
> there is no difference between rcu_read_lock(), rcu_read_lock_bh() and
> rcu_read_lock_sched() in terms of RCU read section and the relevant grace
> period. That means that spin_lock(), which implies rcu_read_lock_sched(),
> also implies rcu_read_lock().
> 
> There is no need no explicitly start a RCU read section if one has already
> been started implicitly by spin_lock().
> 
> Simplify the code and remove the inner rcu_read_lock() invocation.
> 
> Cc: Tejun Heo <tj at kernel.org>
> Cc: Johannes Weiner <hannes at cmpxchg.org>
> Cc: Waiman Long <longman at redhat.com>
> Signed-off-by: pengdonglin <pengdonglin at xiaomi.com>
> Signed-off-by: pengdonglin <dolinux.peng at gmail.com>

Applied to cgroup/for-6.18.

Thanks.

-- 
tejun