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

Pull RCU updates from Ingo Molnar:
 "The main RCU changes in this cycle are:

   - Idle entry/exit changes, to throttle callback execution and other
     refinements to speed up kbuild, primarily to address performance
     issues located by Tibor Billes.

   - Grace-period related changes, primarily to aid in debugging,
     inspired by an -rt debugging session.

   - Code reorganization moving RCU's source files into its own
     kernel/rcu/ directory.

   - RCU documentation updates

   - Miscellaneous fixes.

  Note, the following commit:

    5c889690 mm: Place preemption point in do_mlockall() loop

  is identical to the commit already in your tree via email:

    22356f44 mm: Place preemption point in do_mlockall() loop

  [ Your version of the changelog nicely demonstrates it how kernel oops
    messages should be trimmed properly :-/ ]"

* 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (30 commits)
  rcu: Move RCU-related source code to kernel/rcu directory
  rcu: Fix occurrence of "the the" in checklist.txt
  kthread: Add pointer to vmstat-avoidance patch
  rcu: Update stall-warning documentation
  rcu: Consistent rcu_is_watching() naming
  rcu: Change EXPORT_SYMBOL() to EXPORT_SYMBOL_GPL()
  rcu: Is it safe to enter an RCU read-side critical section?
  rcu: Throttle invoke_rcu_core() invocations due to non-lazy callbacks
  rcu: Throttle rcu_try_advance_all_cbs() execution
  rcu: Remove redundant code from rcu_cleanup_after_idle()
  rcu: Fix CONFIG_RCU_NOCB_CPU_ALL panic on machines with sparse CPU mask
  rcu: Avoid sparse warnings in rcu_nocb_wake trace event
  rcu: Track rcu_nocb_kthread()'s sleeping and awakening
  rcu: Distinguish between NOCB and non-NOCB rcu_callback trace events
  rcu: Add tracing for rcuo no-CBs CPU wakeup handshake
  rcu: Add tracing of normal (non-NOCB) grace-period requests
  rcu: Add tracing to rcu_gp_kthread()
  rcu: Flag lockless access to ->gp_flags with ACCESS_ONCE()
  rcu: Prevent spurious-wakeup DoS attack on rcu_gp_kthread()
  rcu: Improve grace-period start logic
  ...