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

Pull RCU updates from Paul E. McKenney:

 "The largest feature of this series is shrinking and simplification,
  with the following diffstat summary:

     79 files changed, 1496 insertions(+), 4211 deletions(-)

  In other words, this series represents a net reduction of more than 2700
  lines of code."

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

Documentation/admin-guide/kernel-parameters.txt

@@ -3238,21 +3238,17 @@
 
 	rcutree.gp_cleanup_delay=	[KNL]
 			Set the number of jiffies to delay each step of
-			RCU grace-period cleanup.  This only has effect
-			when CONFIG_RCU_TORTURE_TEST_SLOW_CLEANUP is set.
+			RCU grace-period cleanup.
 
 	rcutree.gp_init_delay=	[KNL]
 			Set the number of jiffies to delay each step of
-			RCU grace-period initialization.  This only has
-			effect when CONFIG_RCU_TORTURE_TEST_SLOW_INIT
-			is set.
+			RCU grace-period initialization.
 
 	rcutree.gp_preinit_delay=	[KNL]
 			Set the number of jiffies to delay each step of
 			RCU grace-period pre-initialization, that is,
 			the propagation of recent CPU-hotplug changes up
-			the rcu_node combining tree.  This only has effect
-			when CONFIG_RCU_TORTURE_TEST_SLOW_PREINIT is set.
+			the rcu_node combining tree.
 
 	rcutree.rcu_fanout_exact= [KNL]
 			Disable autobalancing of the rcu_node combining
@@ -3328,6 +3324,17 @@
 			This wake_up() will be accompanied by a
 			WARN_ONCE() splat and an ftrace_dump().
 
+	rcuperf.gp_async= [KNL]
+			Measure performance of asynchronous
+			grace-period primitives such as call_rcu().
+
+	rcuperf.gp_async_max= [KNL]
+			Specify the maximum number of outstanding
+			callbacks per writer thread.  When a writer
+			thread exceeds this limit, it invokes the
+			corresponding flavor of rcu_barrier() to allow
+			previously posted callbacks to drain.
+
 	rcuperf.gp_exp= [KNL]
 			Measure performance of expedited synchronous
 			grace-period primitives.
@@ -3355,17 +3362,22 @@
 	rcuperf.perf_runnable= [BOOT]
 			Start rcuperf running at boot time.
 
+	rcuperf.perf_type= [KNL]
+			Specify the RCU implementation to test.
+
 	rcuperf.shutdown= [KNL]
 			Shut the system down after performance tests
 			complete.  This is useful for hands-off automated
 			testing.
 
-	rcuperf.perf_type= [KNL]
-			Specify the RCU implementation to test.
-
 	rcuperf.verbose= [KNL]
 			Enable additional printk() statements.
 
+	rcuperf.writer_holdoff= [KNL]
+			Write-side holdoff between grace periods,
+			in microseconds.  The default of zero says
+			no holdoff.
+
 	rcutorture.cbflood_inter_holdoff= [KNL]
 			Set holdoff time (jiffies) between successive
 			callback-flood tests.
@@ -3803,6 +3815,15 @@
 	spia_pedr=
 	spia_peddr=
 
+	srcutree.counter_wrap_check [KNL]
+			Specifies how frequently to check for
+			grace-period sequence counter wrap for the
+			srcu_data structure's ->srcu_gp_seq_needed field.
+			The greater the number of bits set in this kernel
+			parameter, the less frequently counter wrap will
+			be checked for.  Note that the bottom two bits
+			are ignored.
+
 	srcutree.exp_holdoff [KNL]
 			Specifies how many nanoseconds must elapse
 			since the end of the last SRCU grace period for