rcu: Simplify curing of load woes

Make the functions creating the kthreads wake them up.  Leverage the
fact that the per-node and boost kthreads can run anywhere, thus
dispensing with the need to wake them up once the incoming CPU has
gone fully online.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Tested-by: Daniel J Blueman <daniel.blueman@gmail.com>

1 files changed, 1 insertions, 10 deletions

diff --git a/kernel/rcutree_plugin.h b/kernel/rcutree_plugin.h
index c8bff3099a89..ea2e2fb79e81 100644
--- a/kernel/rcutree_plugin.h
+++ b/kernel/rcutree_plugin.h
@@ -1299,15 +1299,10 @@ static int __cpuinit rcu_spawn_one_boost_kthread(struct rcu_state *rsp,
         raw_spin_unlock_irqrestore(&rnp->lock, flags);
         sp.sched_priority = RCU_KTHREAD_PRIO;
         sched_setscheduler_nocheck(t, SCHED_FIFO, &sp);
+        wake_up_process(t); /* get to TASK_INTERRUPTIBLE quickly. */
         return 0;
 }
 
-static void __cpuinit rcu_wake_one_boost_kthread(struct rcu_node *rnp)
-{
-        if (rnp->boost_kthread_task)
-                wake_up_process(rnp->boost_kthread_task);
-}
-
 #else /* #ifdef CONFIG_RCU_BOOST */
 
 static void rcu_initiate_boost(struct rcu_node *rnp, unsigned long flags)
@@ -1331,10 +1326,6 @@ static int __cpuinit rcu_spawn_one_boost_kthread(struct rcu_state *rsp,
         return 0;
 }
 
-static void __cpuinit rcu_wake_one_boost_kthread(struct rcu_node *rnp)
-{
-}
-
 #endif /* #else #ifdef CONFIG_RCU_BOOST */
 
 #ifndef CONFIG_SMP