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

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