Messages in this thread Patch in this message | | | From | Frederic Weisbecker <> | Subject | [PATCH 03/10] rcu: Make locking explicit in do_nocb_deferred_wakeup_common() | Date | Wed, 13 May 2020 18:47:07 +0200 |
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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 <frederic@kernel.org> Cc: Paul E. McKenney <paulmck@kernel.org> Cc: Josh Triplett <josh@joshtriplett.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Lai Jiangshan <jiangshanlai@gmail.com> Cc: Joel Fernandes <joel@joelfernandes.org> --- 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
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