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

Pull RCU and LKMM changes from Paul E. McKenney:

  - Documentation updates.

  - Miscellaneous fixes.

  - Dynamic tick (nohz) updates, perhaps most notably changes to
    force the tick on when needed due to lengthy in-kernel execution
    on CPUs on which RCU is waiting.

  - Replace rcu_swap_protected() with rcu_prepace_pointer().

  - Torture-test updates.

  - Linux-kernel memory consistency model updates.

Signed-off-by: Ingo Molnar <mingo@kernel.org>

2 files changed, 28 insertions, 22 deletions

diff --git a/include/trace/events/rcu.h b/include/trace/events/rcu.h
index 694bd040cf51..66122602bd08 100644
--- a/include/trace/events/rcu.h
+++ b/include/trace/events/rcu.h
@@ -93,16 +93,16 @@ TRACE_EVENT_RCU(rcu_grace_period,
  * the data from the rcu_node structure, other than rcuname, which comes
  * from the rcu_state structure, and event, which is one of the following:
  *
- * "Startleaf": Request a grace period based on leaf-node data.
+ * "Cleanup": Clean up rcu_node structure after previous GP.
+ * "CleanupMore": Clean up, and another GP is needed.
+ * "EndWait": Complete wait.
+ * "NoGPkthread": The RCU grace-period kthread has not yet started.
  * "Prestarted": Someone beat us to the request
  * "Startedleaf": Leaf node marked for future GP.
  * "Startedleafroot": All nodes from leaf to root marked for future GP.
  * "Startedroot": Requested a nocb grace period based on root-node data.
- * "NoGPkthread": The RCU grace-period kthread has not yet started.
+ * "Startleaf": Request a grace period based on leaf-node data.
  * "StartWait": Start waiting for the requested grace period.
- * "EndWait": Complete wait.
- * "Cleanup": Clean up rcu_node structure after previous GP.
- * "CleanupMore": Clean up, and another GP is needed.
  */
 TRACE_EVENT_RCU(rcu_future_grace_period,
 
@@ -258,20 +258,27 @@ TRACE_EVENT_RCU(rcu_exp_funnel_lock,
  * the number of the offloaded CPU are extracted.  The third and final
  * argument is a string as follows:
  *
- *	"WakeEmpty": Wake rcuo kthread, first CB to empty list.
- *	"WakeEmptyIsDeferred": Wake rcuo kthread later, first CB to empty list.
- *	"WakeOvf": Wake rcuo kthread, CB list is huge.
- *	"WakeOvfIsDeferred": Wake rcuo kthread later, CB list is huge.
- *	"WakeNot": Don't wake rcuo kthread.
- *	"WakeNotPoll": Don't wake rcuo kthread because it is polling.
- *	"DeferredWake": Carried out the "IsDeferred" wakeup.
- *	"Poll": Start of new polling cycle for rcu_nocb_poll.
- *	"Sleep": Sleep waiting for GP for !rcu_nocb_poll.
- *	"CBSleep": Sleep waiting for CBs for !rcu_nocb_poll.
- *	"WokeEmpty": rcuo kthread woke to find empty list.
- *	"WokeNonEmpty": rcuo kthread woke to find non-empty list.
- *	"WaitQueue": Enqueue partially done, timed wait for it to complete.
- *	"WokeQueue": Partial enqueue now complete.
+ * "AlreadyAwake": The to-be-awakened rcuo kthread is already awake.
+ * "Bypass": rcuo GP kthread sees non-empty ->nocb_bypass.
+ * "CBSleep": rcuo CB kthread sleeping waiting for CBs.
+ * "Check": rcuo GP kthread checking specified CPU for work.
+ * "DeferredWake": Timer expired or polled check, time to wake.
+ * "DoWake": The to-be-awakened rcuo kthread needs to be awakened.
+ * "EndSleep": Done waiting for GP for !rcu_nocb_poll.
+ * "FirstBQ": New CB to empty ->nocb_bypass (->cblist maybe non-empty).
+ * "FirstBQnoWake": FirstBQ plus rcuo kthread need not be awakened.
+ * "FirstBQwake": FirstBQ plus rcuo kthread must be awakened.
+ * "FirstQ": New CB to empty ->cblist (->nocb_bypass maybe non-empty).
+ * "NeedWaitGP": rcuo GP kthread must wait on a grace period.
+ * "Poll": Start of new polling cycle for rcu_nocb_poll.
+ * "Sleep": Sleep waiting for GP for !rcu_nocb_poll.
+ * "Timer": Deferred-wake timer expired.
+ * "WakeEmptyIsDeferred": Wake rcuo kthread later, first CB to empty list.
+ * "WakeEmpty": Wake rcuo kthread, first CB to empty list.
+ * "WakeNot": Don't wake rcuo kthread.
+ * "WakeNotPoll": Don't wake rcuo kthread because it is polling.
+ * "WakeOvfIsDeferred": Wake rcuo kthread later, CB list is huge.
+ * "WokeEmpty": rcuo CB kthread woke to find empty list.
  */
 TRACE_EVENT_RCU(rcu_nocb_wake,
 
@@ -713,8 +720,6 @@ TRACE_EVENT_RCU(rcu_torture_read,
  *	"Begin": rcu_barrier() started.
  *	"EarlyExit": rcu_barrier() piggybacked, thus early exit.
  *	"Inc1": rcu_barrier() piggyback check counter incremented.
- *	"OfflineNoCB": rcu_barrier() found callback on never-online CPU
- *	"OnlineNoCB": rcu_barrier() found online no-CBs CPU.
  *	"OnlineQ": rcu_barrier() found online CPU with callbacks.
  *	"OnlineNQ": rcu_barrier() found online CPU, no callbacks.
  *	"IRQ": An rcu_barrier_callback() callback posted on remote CPU.
diff --git a/include/trace/events/timer.h b/include/trace/events/timer.h
index b7a904825e7d..295517f109d7 100644
--- a/include/trace/events/timer.h
+++ b/include/trace/events/timer.h
@@ -367,7 +367,8 @@ TRACE_EVENT(itimer_expire,
 		tick_dep_name(POSIX_TIMER)		\
 		tick_dep_name(PERF_EVENTS)		\
 		tick_dep_name(SCHED)			\
-		tick_dep_name_end(CLOCK_UNSTABLE)
+		tick_dep_name(CLOCK_UNSTABLE)		\
+		tick_dep_name_end(RCU)
 
 #undef tick_dep_name
 #undef tick_dep_mask_name