Commit e02691b7 authored by Frederic Weisbecker's avatar Frederic Weisbecker Committed by Paul E. McKenney
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rcu/nocb: Move trace_rcu_nocb_wake() calls outside nocb_lock when possible 



Those tracing calls don't need to be under ->nocb_lock.  This commit
therefore moves them outside of that lock.

Signed-off-by: default avatarFrederic Weisbecker <frederic@kernel.org>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Lai Jiangshan <jiangshanlai@gmail.com>
Cc: Joel Fernandes <joel@joelfernandes.org>
Cc: Neeraj Upadhyay <neeraju@codeaurora.org>
Cc: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: default avatarPaul E. McKenney <paulmck@kernel.org>
parent 0efdf14a

kernel/rcu/tree_plugin.h

+3 −3
Original line number Diff line number Diff line
@@ -1703,9 +1703,9 @@ static bool wake_nocb_gp(struct rcu_data *rdp, bool force, 


	lockdep_assert_held(&rdp->nocb_lock);

	if (!READ_ONCE(rdp_gp->nocb_gp_kthread)) {

		rcu_nocb_unlock_irqrestore(rdp, flags);

		trace_rcu_nocb_wake(rcu_state.name, rdp->cpu,

				    TPS("AlreadyAwake"));

		rcu_nocb_unlock_irqrestore(rdp, flags);

		return false;

	}
@@ -1955,9 +1955,9 @@ static void __call_rcu_nocb_wake(struct rcu_data *rdp, bool was_alldone, 
	// If we are being polled or there is no kthread, just leave.

	t = READ_ONCE(rdp->nocb_gp_kthread);

	if (rcu_nocb_poll || !t) {

		rcu_nocb_unlock_irqrestore(rdp, flags);

		trace_rcu_nocb_wake(rcu_state.name, rdp->cpu,

				    TPS("WakeNotPoll"));

		rcu_nocb_unlock_irqrestore(rdp, flags);

		return;

	}

	// Need to actually to a wakeup.
@@ -1992,8 +1992,8 @@ static void __call_rcu_nocb_wake(struct rcu_data *rdp, bool was_alldone, 
					   TPS("WakeOvfIsDeferred"));

		rcu_nocb_unlock_irqrestore(rdp, flags);

	} else {

		trace_rcu_nocb_wake(rcu_state.name, rdp->cpu, TPS("WakeNot"));

		rcu_nocb_unlock_irqrestore(rdp, flags);

		trace_rcu_nocb_wake(rcu_state.name, rdp->cpu, TPS("WakeNot"));

	}

	return;

}