Merge branch 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull core fixes from Ingo Molnar:
 "The tree contains two RCU fixes and a compiler quirk comment fix"

* 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  rcu: Make rcu_barrier() understand about missing rcuo kthreads
  compiler/gcc4+: Remove inaccurate comment about 'asm goto' miscompiles
  rcu: More on deadlock between CPU hotplug and expedited grace periods

1 files changed, 10 insertions, 5 deletions

diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index 133e47223095..9815447d22e0 100644
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -3299,11 +3299,16 @@ static void _rcu_barrier(struct rcu_state *rsp)
                         continue;
                 rdp = per_cpu_ptr(rsp->rda, cpu);
                 if (rcu_is_nocb_cpu(cpu)) {
-                        _rcu_barrier_trace(rsp, "OnlineNoCB", cpu,
-                                           rsp->n_barrier_done);
-                        atomic_inc(&rsp->barrier_cpu_count);
-                        __call_rcu(&rdp->barrier_head, rcu_barrier_callback,
-                                   rsp, cpu, 0);
+                        if (!rcu_nocb_cpu_needs_barrier(rsp, cpu)) {
+                                _rcu_barrier_trace(rsp, "OfflineNoCB", cpu,
+                                                   rsp->n_barrier_done);
+                        } else {
+                                _rcu_barrier_trace(rsp, "OnlineNoCB", cpu,
+                                                   rsp->n_barrier_done);
+                                atomic_inc(&rsp->barrier_cpu_count);
+                                __call_rcu(&rdp->barrier_head,
+                                           rcu_barrier_callback, rsp, cpu, 0);
+                        }
                 } else if (ACCESS_ONCE(rdp->qlen)) {
                         _rcu_barrier_trace(rsp, "OnlineQ", cpu,
                                            rsp->n_barrier_done);