[PATCH RFC tip/core/rcu 4/5] rcu: Wake grace-period kthread at end of expedited grace period

["Paul E. McKenney" <paulmck@linux.vnet.ibm.com>]

From: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>

Let the expedited grace period confer its lower latency onto any
normal grace period that is in progress.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
---
 kernel/rcu/tree.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index 5365f6332a60..308b6acb4260 100644
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -3507,6 +3507,8 @@ void synchronize_sched_expedited(void)
 	rcu_exp_gp_seq_end(rsp);
 	mutex_unlock(&rnp->exp_funnel_mutex);
 	smp_mb(); /* ensure subsequent action seen after grace period. */
+	if (rsp->gp_kthread && rcu_gp_in_progress(rsp))
+		wake_up(&rsp->gp_wq);
 
 	put_online_cpus();
 }
-- 
1.8.1.5