The following commit has been merged into the core/rcu branch of tip:

Commit-ID:     e02691b7ef51c5fac0eee5a6ebde45ce92958fae
Gitweb:        
https://git.kernel.org/tip/e02691b7ef51c5fac0eee5a6ebde45ce92958fae
Author:        Frederic Weisbecker <frede...@kernel.org>
AuthorDate:    Tue, 23 Feb 2021 01:10:02 +01:00
Committer:     Paul E. McKenney <paul...@kernel.org>
CommitterDate: Mon, 15 Mar 2021 13:54:55 -07:00

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: Frederic Weisbecker <frede...@kernel.org>
Cc: Josh Triplett <j...@joshtriplett.org>
Cc: Lai Jiangshan <jiangshan...@gmail.com>
Cc: Joel Fernandes <j...@joelfernandes.org>
Cc: Neeraj Upadhyay <neer...@codeaurora.org>
Cc: Boqun Feng <boqun.f...@gmail.com>
Signed-off-by: Paul E. McKenney <paul...@kernel.org>
---
 kernel/rcu/tree_plugin.h | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h
index b08564b..9846c8a 100644
--- a/kernel/rcu/tree_plugin.h
+++ b/kernel/rcu/tree_plugin.h
@@ -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;
 }

Reply via email to