rcu: Teach RCU that idle task is not quiscent state at boot

[safe/jmp/linux-2.6] / kernel / rcupreempt.c

diff --git a/kernel/rcupreempt.c b/kernel/rcupreempt.c
index 33cfc50..5d59e85 100644 (file)
--- a/kernel/rcupreempt.c
+++ b/kernel/rcupreempt.c
@@ -1181,6 +1181,9 @@ void __synchronize_sched(void)
 {
        struct rcu_synchronize rcu;
 
+       if (num_online_cpus() == 1)
+               return;  /* blocking is gp if only one CPU! */
+
        init_completion(&rcu.completion);
        /* Will wake me after RCU finished. */
        call_rcu_sched(&rcu.head, wakeme_after_rcu);