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

Pull RCU updates from Ingo Molnar:
 "The main changes in this cycle are mostly related to preparatory work
  for the full-dynticks work:

   - Remove restrictions on no-CBs CPUs, make RCU_FAST_NO_HZ take
     advantage of numbered callbacks, do callback accelerations based on
     numbered callbacks.  Posted to LKML at
        https://lkml.org/lkml/2013/3/18/960

   - RCU documentation updates.  Posted to LKML at
        https://lkml.org/lkml/2013/3/18/570

   - Miscellaneous fixes.  Posted to LKML at
        https://lkml.org/lkml/2013/3/18/594"

* 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (24 commits)
  rcu: Make rcu_accelerate_cbs() note need for future grace periods
  rcu: Abstract rcu_start_future_gp() from rcu_nocb_wait_gp()
  rcu: Rename n_nocb_gp_requests to need_future_gp
  rcu: Push lock release to rcu_start_gp()'s callers
  rcu: Repurpose no-CBs event tracing to future-GP events
  rcu: Rearrange locking in rcu_start_gp()
  rcu: Make RCU_FAST_NO_HZ take advantage of numbered callbacks
  rcu: Accelerate RCU callbacks at grace-period end
  rcu: Export RCU_FAST_NO_HZ parameters to sysfs
  rcu: Distinguish "rcuo" kthreads by RCU flavor
  rcu: Add event tracing for no-CBs CPUs' grace periods
  rcu: Add event tracing for no-CBs CPUs' callback registration
  rcu: Introduce proper blocking to no-CBs kthreads GP waits
  rcu: Provide compile-time control for no-CBs CPUs
  rcu: Tone down debugging during boot-up and shutdown.
  rcu: Add softirq-stall indications to stall-warning messages
  rcu: Documentation update
  rcu: Make bugginess of code sample more evident
  rcu: Fix hlist_bl_set_first_rcu() annotation
  rcu: Delete unused rcu_node "wakemask" field
  ...

diff --cc Documentation/kernel-parameters.txt
Simple merge

diff --cc kernel/rcutree.c
index 2f8530bc4b1778ecbbd4221b668cb933c2cbad96,2d5f94c1c7fb01783bb49cbde52ad98c8b74386e..d8534308fd052f9a9446929f170a4ceb9d6e30b1
--- 1/kernel/rcutree.c
--- 2/kernel/rcutree.c
+++ b/kernel/rcutree.c
@@@ -1319,7 -1441,8 +1441,8 @@@ static int rcu_gp_init(struct rcu_stat
                                            rnp->grphi, rnp->qsmask);
                raw_spin_unlock_irq(&rnp->lock);
  #ifdef CONFIG_PROVE_RCU_DELAY
-               if ((prandom_u32() % (rcu_num_nodes * 8)) == 0)
 -              if ((random32() % (rcu_num_nodes * 8)) == 0 &&
++              if ((prandom_u32() % (rcu_num_nodes * 8)) == 0 &&
+                   system_state == SYSTEM_RUNNING)
                        schedule_timeout_uninterruptible(2);
  #endif /* #ifdef CONFIG_PROVE_RCU_DELAY */
                cond_resched();