It can either be called inline (locally or CPU hotplug locked) when rdp->nocb_defer_wakeup is pending or from the nocb timer. In both cases the rdp is offlined and we want to take the nocb lock.
Clarify the locking rules and expectations. Signed-off-by: Frederic Weisbecker <[email protected]> Cc: Paul E. McKenney <[email protected]> Cc: Josh Triplett <[email protected]> Cc: Steven Rostedt <[email protected]> Cc: Mathieu Desnoyers <[email protected]> Cc: Lai Jiangshan <[email protected]> Cc: Joel Fernandes <[email protected]> --- kernel/rcu/tree_plugin.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h index 1d22b16c03e0..1dd3fdd675a1 100644 --- a/kernel/rcu/tree_plugin.h +++ b/kernel/rcu/tree_plugin.h @@ -2142,9 +2142,9 @@ static void do_nocb_deferred_wakeup_common(struct rcu_data *rdp) unsigned long flags; int ndw; - rcu_nocb_lock_irqsave(rdp, flags); + raw_spin_lock_irqsave(&rdp->nocb_lock, flags); if (!rcu_nocb_need_deferred_wakeup(rdp)) { - rcu_nocb_unlock_irqrestore(rdp, flags); + raw_spin_unlock_irqrestore(&rdp->nocb_lock, flags); return; } ndw = READ_ONCE(rdp->nocb_defer_wakeup); -- 2.25.0
