Merge remote-tracking branch 'rcu/rcu/next'

25 files changed, 638 insertions, 351 deletions

diff --git a/Documentation/RCU/NMI-RCU.txt b/Documentation/RCU/NMI-RCU.txt
index bf82851a0e57..687777f83b23 100644
--- a/Documentation/RCU/NMI-RCU.txt
+++ b/Documentation/RCU/NMI-RCU.txt
@@ -95,7 +95,7 @@ not to return until all ongoing NMI handlers exit.  It is therefore safe
 to free up the handler's data as soon as synchronize_sched() returns.
 
 Important note: for this to work, the architecture in question must
-invoke irq_enter() and irq_exit() on NMI entry and exit, respectively.
+invoke nmi_enter() and nmi_exit() on NMI entry and exit, respectively.
 
 
 Answer to Quick Quiz
diff --git a/Documentation/RCU/torture.txt b/Documentation/RCU/torture.txt
index 5d9016795fd8..783d6c134d3f 100644
--- a/Documentation/RCU/torture.txt
+++ b/Documentation/RCU/torture.txt
@@ -42,7 +42,7 @@ fqs_holdoff	Holdoff time (in microseconds) between consecutive calls
 fqs_stutter	Wait time (in seconds) between consecutive bursts
 		of calls to force_quiescent_state().
 
-irqreaders	Says to invoke RCU readers from irq level.  This is currently
+irqreader	Says to invoke RCU readers from irq level.  This is currently
 		done via timers.  Defaults to "1" for variants of RCU that
 		permit this.  (Or, more accurately, variants of RCU that do
 		-not- permit this know to ignore this variable.)
@@ -79,19 +79,68 @@ stutter		The length of time to run the test before pausing for this
 		Specifying "stutter=0" causes the test to run continuously
 		without pausing, which is the old default behavior.
 
+test_boost	Whether or not to test the ability of RCU to do priority
+		boosting.  Defaults to "test_boost=1", which performs
+		RCU priority-inversion testing only if the selected
+		RCU implementation supports priority boosting.  Specifying
+		"test_boost=0" never performs RCU priority-inversion
+		testing.  Specifying "test_boost=2" performs RCU
+		priority-inversion testing even if the selected RCU
+		implementation does not support RCU priority boosting,
+		which can be used to test rcutorture's ability to
+		carry out RCU priority-inversion testing.
+
+test_boost_interval
+		The number of seconds in an RCU priority-inversion test
+		cycle.	Defaults to "test_boost_interval=7".  It is
+		usually wise for this value to be relatively prime to
+		the value selected for "stutter".
+
+test_boost_duration
+		The number of seconds to do RCU priority-inversion testing
+		within any given "test_boost_interval".  Defaults to
+		"test_boost_duration=4".
+
 test_no_idle_hz	Whether or not to test the ability of RCU to operate in
 		a kernel that disables the scheduling-clock interrupt to
 		idle CPUs.  Boolean parameter, "1" to test, "0" otherwise.
 		Defaults to omitting this test.
 
-torture_type	The type of RCU to test: "rcu" for the rcu_read_lock() API,
-		"rcu_sync" for rcu_read_lock() with synchronous reclamation,
-		"rcu_bh" for the rcu_read_lock_bh() API, "rcu_bh_sync" for
-		rcu_read_lock_bh() with synchronous reclamation, "srcu" for
-		the "srcu_read_lock()" API, "sched" for the use of
-		preempt_disable() together with synchronize_sched(),
-		and "sched_expedited" for the use of preempt_disable()
-		with synchronize_sched_expedited().
+torture_type	The type of RCU to test, with string values as follows:
+
+		"rcu":  rcu_read_lock(), rcu_read_unlock() and call_rcu().
+
+		"rcu_sync":  rcu_read_lock(), rcu_read_unlock(), and
+			synchronize_rcu().
+
+		"rcu_expedited": rcu_read_lock(), rcu_read_unlock(), and
+			synchronize_rcu_expedited().
+
+		"rcu_bh": rcu_read_lock_bh(), rcu_read_unlock_bh(), and
+			call_rcu_bh().
+
+		"rcu_bh_sync": rcu_read_lock_bh(), rcu_read_unlock_bh(),
+			and synchronize_rcu_bh().
+
+		"rcu_bh_expedited": rcu_read_lock_bh(), rcu_read_unlock_bh(),
+			and synchronize_rcu_bh_expedited().
+
+		"srcu": srcu_read_lock(), srcu_read_unlock() and
+			synchronize_srcu().
+
+		"srcu_expedited": srcu_read_lock(), srcu_read_unlock() and
+			synchronize_srcu_expedited().
+
+		"sched": preempt_disable(), preempt_enable(), and
+			call_rcu_sched().
+
+		"sched_sync": preempt_disable(), preempt_enable(), and
+			synchronize_sched().
+
+		"sched_expedited": preempt_disable(), preempt_enable(), and
+			synchronize_sched_expedited().
+
+		Defaults to "rcu".
 
 verbose		Enable debug printk()s.  Default is disabled.
 
@@ -100,12 +149,12 @@ OUTPUT
 
 The statistics output is as follows:
 
-	rcu-torture: --- Start of test: nreaders=16 stat_interval=0 verbose=0
-	rcu-torture: rtc: 0000000000000000 ver: 1916 tfle: 0 rta: 1916 rtaf: 0 rtf: 1915
-	rcu-torture: Reader Pipe:  1466408 9747 0 0 0 0 0 0 0 0 0
-	rcu-torture: Reader Batch:  1464477 11678 0 0 0 0 0 0 0 0
-	rcu-torture: Free-Block Circulation:  1915 1915 1915 1915 1915 1915 1915 1915 1915 1915 0
-	rcu-torture: --- End of test
+	rcu-torture:--- Start of test: nreaders=16 nfakewriters=4 stat_interval=30 verbose=0 test_no_idle_hz=1 shuffle_interval=3 stutter=5 irqreader=1 fqs_duration=0 fqs_holdoff=0 fqs_stutter=3 test_boost=1/0 test_boost_interval=7 test_boost_duration=4
+	rcu-torture: rtc:           (null) ver: 155441 tfle: 0 rta: 155441 rtaf: 8884 rtf: 155440 rtmbe: 0 rtbke: 0 rtbre: 0 rtbf: 0 rtb: 0 nt: 3055767
+	rcu-torture: Reader Pipe:  727860534 34213 0 0 0 0 0 0 0 0 0
+	rcu-torture: Reader Batch:  727877838 17003 0 0 0 0 0 0 0 0 0
+	rcu-torture: Free-Block Circulation:  155440 155440 155440 155440 155440 155440 155440 155440 155440 155440 0
+	rcu-torture:--- End of test: SUCCESS: nreaders=16 nfakewriters=4 stat_interval=30 verbose=0 test_no_idle_hz=1 shuffle_interval=3 stutter=5 irqreader=1 fqs_duration=0 fqs_holdoff=0 fqs_stutter=3 test_boost=1/0 test_boost_interval=7 test_boost_duration=4
 
 The command "dmesg | grep torture:" will extract this information on
 most systems.  On more esoteric configurations, it may be necessary to
@@ -113,26 +162,55 @@ use other commands to access the output of the printk()s used by
 the RCU torture test.  The printk()s use KERN_ALERT, so they should
 be evident.  ;-)
 
+The first and last lines show the rcutorture module parameters, and the
+last line shows either "SUCCESS" or "FAILURE", based on rcutorture's
+automatic determination as to whether RCU operated correctly.
+
 The entries are as follows:
 
 o	"rtc": The hexadecimal address of the structure currently visible
 	to readers.
 
-o	"ver": The number of times since boot that the rcutw writer task
+o	"ver": The number of times since boot that the RCU writer task
 	has changed the structure visible to readers.
 
 o	"tfle": If non-zero, indicates that the "torture freelist"
-	containing structure to be placed into the "rtc" area is empty.
+	containing structures to be placed into the "rtc" area is empty.
 	This condition is important, since it can fool you into thinking
 	that RCU is working when it is not.  :-/
 
 o	"rta": Number of structures allocated from the torture freelist.
 
 o	"rtaf": Number of allocations from the torture freelist that have
-	failed due to the list being empty.
+	failed due to the list being empty.  It is not unusual for this
+	to be non-zero, but it is bad for it to be a large fraction of
+	the value indicated by "rta".
 
 o	"rtf": Number of frees into the torture freelist.
 
+o	"rtmbe": A non-zero value indicates that rcutorture believes that
+	rcu_assign_pointer() and rcu_dereference() are not working
+	correctly.  This value should be zero.
+
+o	"rtbke": rcutorture was unable to create the real-time kthreads
+	used to force RCU priority inversion.  This value should be zero.
+
+o	"rtbre": Although rcutorture successfully created the kthreads
+	used to force RCU priority inversion, it was unable to set them
+	to the real-time priority level of 1.  This value should be zero.
+
+o	"rtbf": The number of times that RCU priority boosting failed
+	to resolve RCU priority inversion.
+
+o	"rtb": The number of times that rcutorture attempted to force
+	an RCU priority inversion condition.  If you are testing RCU
+	priority boosting via the "test_boost" module parameter, this
+	value should be non-zero.
+
+o	"nt": The number of times rcutorture ran RCU read-side code from
+	within a timer handler.  This value should be non-zero only
+	if you specified the "irqreader" module parameter.
+
 o	"Reader Pipe": Histogram of "ages" of structures seen by readers.
 	If any entries past the first two are non-zero, RCU is broken.
 	And rcutorture prints the error flag string "!!!" to make sure
@@ -162,26 +240,15 @@ o	"Free-Block Circulation": Shows the number of torture structures
 	somehow gets incremented farther than it should.
 
 Different implementations of RCU can provide implementation-specific
-additional information.  For example, SRCU provides the following:
+additional information.  For example, SRCU provides the following
+additional line:
 
-	srcu-torture: rtc: f8cf46a8 ver: 355 tfle: 0 rta: 356 rtaf: 0 rtf: 346 rtmbe: 0
-	srcu-torture: Reader Pipe:  559738 939 0 0 0 0 0 0 0 0 0
-	srcu-torture: Reader Batch:  560434 243 0 0 0 0 0 0 0 0
-	srcu-torture: Free-Block Circulation:  355 354 353 352 351 350 349 348 347 346 0
 	srcu-torture: per-CPU(idx=1): 0(0,1) 1(0,1) 2(0,0) 3(0,1)
 
-The first four lines are similar to those for RCU.  The last line shows
-the per-CPU counter state.  The numbers in parentheses are the values
-of the "old" and "current" counters for the corresponding CPU.  The
-"idx" value maps the "old" and "current" values to the underlying array,
-and is useful for debugging.
-
-Similarly, sched_expedited RCU provides the following:
-
-	sched_expedited-torture: rtc: d0000000016c1880 ver: 1090796 tfle: 0 rta: 1090796 rtaf: 0 rtf: 1090787 rtmbe: 0 nt: 27713319
-	sched_expedited-torture: Reader Pipe:  12660320201 95875 0 0 0 0 0 0 0 0 0
-	sched_expedited-torture: Reader Batch:  12660424885 0 0 0 0 0 0 0 0 0 0
-	sched_expedited-torture: Free-Block Circulation:  1090795 1090795 1090794 1090793 1090792 1090791 1090790 1090789 1090788 1090787 0
+This line shows the per-CPU counter state.  The numbers in parentheses are
+the values of the "old" and "current" counters for the corresponding CPU.
+The "idx" value maps the "old" and "current" values to the underlying
+array, and is useful for debugging.
 
 
 USAGE
diff --git a/Documentation/RCU/trace.txt b/Documentation/RCU/trace.txt
index 8173cec473aa..b9e26d66c27b 100644
--- a/Documentation/RCU/trace.txt
+++ b/Documentation/RCU/trace.txt
@@ -184,10 +184,14 @@ o	"kt" is the per-CPU kernel-thread state.  The digit preceding
 	The number after the final slash is the CPU that the kthread
 	is actually running on.
 
+	This field is displayed only for CONFIG_RCU_BOOST kernels.
+
 o	"ktl" is the low-order 16 bits (in hexadecimal) of the count of
 	the number of times that this CPU's per-CPU kthread has gone
 	through its loop servicing invoke_rcu_cpu_kthread() requests.
 
+	This field is displayed only for CONFIG_RCU_BOOST kernels.
+
 o	"b" is the batch limit for this CPU.  If more than this number
 	of RCU callbacks is ready to invoke, then the remainder will
 	be deferred.
@@ -236,12 +240,12 @@ o	"gpnum" is the number of grace periods that have started.  It is
 
 The output of "cat rcu/rcuhier" looks as follows, with very long lines:
 
-c=6902 g=6903 s=2 jfq=3 j=72c7 nfqs=13142/nfqsng=0(13142) fqlh=6
+c=6902 g=6903 s=2 jfq=3 j=72c7 nfqs=13142/nfqsng=0(13142) fqlh=6 doc=2
 1/1 ..>. 0:127 ^0
 3/3 ..>. 0:35 ^0    0/0 ..>. 36:71 ^1    0/0 ..>. 72:107 ^2    0/0 ..>. 108:127 ^3
 3/3f ..>. 0:5 ^0    2/3 ..>. 6:11 ^1    0/0 ..>. 12:17 ^2    0/0 ..>. 18:23 ^3    0/0 ..>. 24:29 ^4    0/0 ..>. 30:35 ^5    0/0 ..>. 36:41 ^0    0/0 ..>. 42:47 ^1    0/0 ..>. 48:53 ^2    0/0 ..>. 54:59 ^3    0/0 ..>. 60:65 ^4    0/0 ..>. 66:71 ^5    0/0 ..>. 72:77 ^0    0/0 ..>. 78:83 ^1    0/0 ..>. 84:89 ^2    0/0 ..>. 90:95 ^3    0/0 ..>. 96:101 ^4    0/0 ..>. 102:107 ^5    0/0 ..>. 108:113 ^0    0/0 ..>. 114:119 ^1    0/0 ..>. 120:125 ^2    0/0 ..>. 126:127 ^3
 rcu_bh:
-c=-226 g=-226 s=1 jfq=-5701 j=72c7 nfqs=88/nfqsng=0(88) fqlh=0
+c=-226 g=-226 s=1 jfq=-5701 j=72c7 nfqs=88/nfqsng=0(88) fqlh=0 doc=3
 0/1 ..>. 0:127 ^0
 0/3 ..>. 0:35 ^0    0/0 ..>. 36:71 ^1    0/0 ..>. 72:107 ^2    0/0 ..>. 108:127 ^3
 0/3f ..>. 0:5 ^0    0/3 ..>. 6:11 ^1    0/0 ..>. 12:17 ^2    0/0 ..>. 18:23 ^3    0/0 ..>. 24:29 ^4    0/0 ..>. 30:35 ^5    0/0 ..>. 36:41 ^0    0/0 ..>. 42:47 ^1    0/0 ..>. 48:53 ^2    0/0 ..>. 54:59 ^3    0/0 ..>. 60:65 ^4    0/0 ..>. 66:71 ^5    0/0 ..>. 72:77 ^0    0/0 ..>. 78:83 ^1    0/0 ..>. 84:89 ^2    0/0 ..>. 90:95 ^3    0/0 ..>. 96:101 ^4    0/0 ..>. 102:107 ^5    0/0 ..>. 108:113 ^0    0/0 ..>. 114:119 ^1    0/0 ..>. 120:125 ^2    0/0 ..>. 126:127 ^3
@@ -280,6 +284,11 @@ o	"fqlh" is the number of calls to force_quiescent_state() that
 	exited immediately (without even being counted in nfqs above)
 	due to contention on ->fqslock.
 
+o	"dovf" is the ID of the next CPU to be checked for dyntick-idle
+	grace-period overflow.
+
+	This field is displayed only for CONFIG_NO_HZ kernels.
+
 o	Each element of the form "1/1 0:127 ^0" represents one struct
 	rcu_node.  Each line represents one level of the hierarchy, from
 	root to leaves.  It is best to think of the rcu_data structures
diff --git a/drivers/md/linear.c b/drivers/md/linear.c
index abfb59a61ede..6cd2c313e800 100644
--- a/drivers/md/linear.c
+++ b/drivers/md/linear.c
@@ -213,12 +213,6 @@ static int linear_run (mddev_t *mddev)
 	return md_integrity_register(mddev);
 }
 
-static void free_conf(struct rcu_head *head)
-{
-	linear_conf_t *conf = container_of(head, linear_conf_t, rcu);
-	kfree(conf);
-}
-
 static int linear_add(mddev_t *mddev, mdk_rdev_t *rdev)
 {
 	/* Adding a drive to a linear array allows the array to grow.
@@ -247,7 +241,7 @@ static int linear_add(mddev_t *mddev, mdk_rdev_t *rdev)
 	md_set_array_sectors(mddev, linear_size(mddev, 0, 0));
 	set_capacity(mddev->gendisk, mddev->array_sectors);
 	revalidate_disk(mddev->gendisk);
-	call_rcu(&oldconf->rcu, free_conf);
+	kfree_rcu(oldconf, rcu);
 	return 0;
 }
 
diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c
index 0dfa5b598e68..0a0b6fc359e3 100644
--- a/fs/jbd2/journal.c
+++ b/fs/jbd2/journal.c
@@ -2409,11 +2409,6 @@ struct devname_cache {
 static struct devname_cache *devcache[1 << CACHE_SIZE_BITS];
 static DEFINE_SPINLOCK(devname_cache_lock);
 
-static void free_devcache(struct rcu_head *rcu)
-{
-	kfree(rcu);
-}
-
 const char *jbd2_dev_to_name(dev_t device)
 {
 	int	i = hash_32(device, CACHE_SIZE_BITS);
@@ -2442,7 +2437,7 @@ const char *jbd2_dev_to_name(dev_t device)
 			spin_unlock(&devname_cache_lock);
 			return ret;
 		}
-		call_rcu(&devcache[i]->rcu, free_devcache);
+		kfree_rcu(devcache[i], rcu);
 	}
 	devcache[i] = new_dev;
 	devcache[i]->device = device;
diff --git a/include/linux/lockdep.h b/include/linux/lockdep.h
index ef820a3c378b..b6a56e37284c 100644
--- a/include/linux/lockdep.h
+++ b/include/linux/lockdep.h
@@ -548,7 +548,7 @@ do {									\
 #endif
 
 #ifdef CONFIG_PROVE_RCU
-extern void lockdep_rcu_dereference(const char *file, const int line);
+void lockdep_rcu_suspicious(const char *file, const int line, const char *s);
 #endif
 
 #endif /* __LINUX_LOCKDEP_H */
diff --git a/include/linux/rcupdate.h b/include/linux/rcupdate.h
index 99f9aa7c2804..c61a535f2ca0 100644
--- a/include/linux/rcupdate.h
+++ b/include/linux/rcupdate.h
@@ -33,6 +33,7 @@
 #ifndef __LINUX_RCUPDATE_H
 #define __LINUX_RCUPDATE_H
 
+#include <linux/types.h>
 #include <linux/cache.h>
 #include <linux/spinlock.h>
 #include <linux/threads.h>
@@ -64,22 +65,74 @@ static inline void rcutorture_record_progress(unsigned long vernum)
 #define ULONG_CMP_GE(a, b)	(ULONG_MAX / 2 >= (a) - (b))
 #define ULONG_CMP_LT(a, b)	(ULONG_MAX / 2 < (a) - (b))
 
+/* Exported common interfaces */
+
+#ifdef CONFIG_PREEMPT_RCU
+
 /**
- * struct rcu_head - callback structure for use with RCU
- * @next: next update requests in a list
- * @func: actual update function to call after the grace period.
+ * call_rcu() - Queue an RCU callback for invocation after a grace period.
+ * @head: structure to be used for queueing the RCU updates.
+ * @func: actual callback function to be invoked after the grace period
+ *
+ * The callback function will be invoked some time after a full grace
+ * period elapses, in other words after all pre-existing RCU read-side
+ * critical sections have completed.  However, the callback function
+ * might well execute concurrently with RCU read-side critical sections
+ * that started after call_rcu() was invoked.  RCU read-side critical
+ * sections are delimited by rcu_read_lock() and rcu_read_unlock(),
+ * and may be nested.
  */
-struct rcu_head {
-	struct rcu_head *next;
-	void (*func)(struct rcu_head *head);
-};
+extern void call_rcu(struct rcu_head *head,
+			      void (*func)(struct rcu_head *head));
 
-/* Exported common interfaces */
+#else /* #ifdef CONFIG_PREEMPT_RCU */
+
+/* In classic RCU, call_rcu() is just call_rcu_sched(). */
+#define	call_rcu	call_rcu_sched
+
+#endif /* #else #ifdef CONFIG_PREEMPT_RCU */
+
+/**
+ * call_rcu_bh() - Queue an RCU for invocation after a quicker grace period.
+ * @head: structure to be used for queueing the RCU updates.
+ * @func: actual callback function to be invoked after the grace period
+ *
+ * The callback function will be invoked some time after a full grace
+ * period elapses, in other words after all currently executing RCU
+ * read-side critical sections have completed. call_rcu_bh() assumes
+ * that the read-side critical sections end on completion of a softirq
+ * handler. This means that read-side critical sections in process
+ * context must not be interrupted by softirqs. This interface is to be
+ * used when most of the read-side critical sections are in softirq context.
+ * RCU read-side critical sections are delimited by :
+ *  - rcu_read_lock() and  rcu_read_unlock(), if in interrupt context.
+ *  OR
+ *  - rcu_read_lock_bh() and rcu_read_unlock_bh(), if in process context.
+ *  These may be nested.
+ */
+extern void call_rcu_bh(struct rcu_head *head,
+			void (*func)(struct rcu_head *head));
+
+/**
+ * call_rcu_sched() - Queue an RCU for invocation after sched grace period.
+ * @head: structure to be used for queueing the RCU updates.
+ * @func: actual callback function to be invoked after the grace period
+ *
+ * The callback function will be invoked some time after a full grace
+ * period elapses, in other words after all currently executing RCU
+ * read-side critical sections have completed. call_rcu_sched() assumes
+ * that the read-side critical sections end on enabling of preemption
+ * or on voluntary preemption.
+ * RCU read-side critical sections are delimited by :
+ *  - rcu_read_lock_sched() and  rcu_read_unlock_sched(),
+ *  OR
+ *  anything that disables preemption.
+ *  These may be nested.
+ */
 extern void call_rcu_sched(struct rcu_head *head,
 			   void (*func)(struct rcu_head *rcu));
+
 extern void synchronize_sched(void);
-extern void rcu_barrier_bh(void);
-extern void rcu_barrier_sched(void);
 
 static inline void __rcu_read_lock_bh(void)
 {
@@ -152,6 +205,15 @@ static inline void rcu_exit_nohz(void)
 
 #endif /* #else #ifdef CONFIG_NO_HZ */
 
+/*
+ * Infrastructure to implement the synchronize_() primitives in
+ * TREE_RCU and rcu_barrier_() primitives in TINY_RCU.
+ */
+
+typedef void call_rcu_func_t(struct rcu_head *head,
+			     void (*func)(struct rcu_head *head));
+void wait_rcu_gp(call_rcu_func_t crf);
+
 #if defined(CONFIG_TREE_RCU) || defined(CONFIG_TREE_PREEMPT_RCU)
 #include <linux/rcutree.h>
 #elif defined(CONFIG_TINY_RCU) || defined(CONFIG_TINY_PREEMPT_RCU)
@@ -297,19 +359,31 @@ extern int rcu_my_thread_group_empty(void);
 /**
  * rcu_lockdep_assert - emit lockdep splat if specified condition not met
  * @c: condition to check
+ * @s: informative message
  */
-#define rcu_lockdep_assert(c)						\
+#define rcu_lockdep_assert(c, s)					\
 	do {								\
 		static bool __warned;					\
 		if (debug_lockdep_rcu_enabled() && !__warned && !(c)) {	\
 			__warned = true;				\
-			lockdep_rcu_dereference(__FILE__, __LINE__);	\
+			lockdep_rcu_suspicious(__FILE__, __LINE__, s);	\
 		}							\
 	} while (0)
 
+#define rcu_sleep_check()						\
+	do {								\
+		rcu_lockdep_assert(!lock_is_held(&rcu_bh_lock_map),	\
+				   "Illegal context switch in RCU-bh"	\
+				   " read-side critical section");	\
+		rcu_lockdep_assert(!lock_is_held(&rcu_sched_lock_map),	\
+				   "Illegal context switch in RCU-sched"\
+				   " read-side critical section");	\
+	} while (0)
+
 #else /* #ifdef CONFIG_PROVE_RCU */
 
-#define rcu_lockdep_assert(c) do { } while (0)
+#define rcu_lockdep_assert(c, s) do { } while (0)
+#define rcu_sleep_check() do { } while (0)
 
 #endif /* #else #ifdef CONFIG_PROVE_RCU */
 
@@ -338,14 +412,16 @@ extern int rcu_my_thread_group_empty(void);
 #define __rcu_dereference_check(p, c, space) \
 	({ \
 		typeof(*p) *_________p1 = (typeof(*p)*__force )ACCESS_ONCE(p); \
-		rcu_lockdep_assert(c); \
+		rcu_lockdep_assert(c, "suspicious rcu_dereference_check()" \
+				      " usage"); \
 		rcu_dereference_sparse(p, space); \
 		smp_read_barrier_depends(); \
 		((typeof(*p) __force __kernel *)(_________p1)); \
 	})
 #define __rcu_dereference_protected(p, c, space) \
 	({ \
-		rcu_lockdep_assert(c); \
+		rcu_lockdep_assert(c, "suspicious rcu_dereference_protected()" \
+				      " usage"); \
 		rcu_dereference_sparse(p, space); \
 		((typeof(*p) __force __kernel *)(p)); \
 	})
@@ -359,7 +435,9 @@ extern int rcu_my_thread_group_empty(void);
 #define __rcu_dereference_index_check(p, c) \
 	({ \
 		typeof(p) _________p1 = ACCESS_ONCE(p); \
-		rcu_lockdep_assert(c); \
+		rcu_lockdep_assert(c, \
+				   "suspicious rcu_dereference_index_check()" \
+				   " usage"); \
 		smp_read_barrier_depends(); \
 		(_________p1); \
 	})
@@ -716,99 +794,6 @@ static inline notrace void rcu_read_unlock_sched_notrace(void)
 #define RCU_INIT_POINTER(p, v) \
 		p = (typeof(*v) __force __rcu *)(v)
 
-/* Infrastructure to implement the synchronize_() primitives. */
-
-struct rcu_synchronize {
-	struct rcu_head head;
-	struct completion completion;
-};
-
-extern void wakeme_after_rcu(struct rcu_head  *head);
-
-#ifdef CONFIG_PREEMPT_RCU
-
-/**
- * call_rcu() - Queue an RCU callback for invocation after a grace period.
- * @head: structure to be used for queueing the RCU updates.
- * @func: actual callback function to be invoked after the grace period
- *
- * The callback function will be invoked some time after a full grace
- * period elapses, in other words after all pre-existing RCU read-side
- * critical sections have completed.  However, the callback function
- * might well execute concurrently with RCU read-side critical sections
- * that started after call_rcu() was invoked.  RCU read-side critical
- * sections are delimited by rcu_read_lock() and rcu_read_unlock(),
- * and may be nested.
- */
-extern void call_rcu(struct rcu_head *head,
-			      void (*func)(struct rcu_head *head));
-
-#else /* #ifdef CONFIG_PREEMPT_RCU */
-
-/* In classic RCU, call_rcu() is just call_rcu_sched(). */
-#define	call_rcu	call_rcu_sched
-
-#endif /* #else #ifdef CONFIG_PREEMPT_RCU */
-
-/**
- * call_rcu_bh() - Queue an RCU for invocation after a quicker grace period.
- * @head: structure to be used for queueing the RCU updates.
- * @func: actual callback function to be invoked after the grace period
- *
- * The callback function will be invoked some time after a full grace
- * period elapses, in other words after all currently executing RCU
- * read-side critical sections have completed. call_rcu_bh() assumes
- * that the read-side critical sections end on completion of a softirq
- * handler. This means that read-side critical sections in process
- * context must not be interrupted by softirqs. This interface is to be
- * used when most of the read-side critical sections are in softirq context.
- * RCU read-side critical sections are delimited by :
- *  - rcu_read_lock() and  rcu_read_unlock(), if in interrupt context.
- *  OR
- *  - rcu_read_lock_bh() and rcu_read_unlock_bh(), if in process context.
- *  These may be nested.
- */
-extern void call_rcu_bh(struct rcu_head *head,
-			void (*func)(struct rcu_head *head));
-
-/*
- * debug_rcu_head_queue()/debug_rcu_head_unqueue() are used internally
- * by call_rcu() and rcu callback execution, and are therefore not part of the
- * RCU API. Leaving in rcupdate.h because they are used by all RCU flavors.
- */
-
-#ifdef CONFIG_DEBUG_OBJECTS_RCU_HEAD
-# define STATE_RCU_HEAD_READY	0
-# define STATE_RCU_HEAD_QUEUED	1
-
-extern struct debug_obj_descr rcuhead_debug_descr;
-
-static inline void debug_rcu_head_queue(struct rcu_head *head)
-{
-	WARN_ON_ONCE((unsigned long)head & 0x3);
-	debug_object_activate(head, &rcuhead_debug_descr);
-	debug_object_active_state(head, &rcuhead_debug_descr,
-				  STATE_RCU_HEAD_READY,
-				  STATE_RCU_HEAD_QUEUED);
-}
-
-static inline void debug_rcu_head_unqueue(struct rcu_head *head)
-{
-	debug_object_active_state(head, &rcuhead_debug_descr,
-				  STATE_RCU_HEAD_QUEUED,
-				  STATE_RCU_HEAD_READY);
-	debug_object_deactivate(head, &rcuhead_debug_descr);
-}
-#else	/* !CONFIG_DEBUG_OBJECTS_RCU_HEAD */
-static inline void debug_rcu_head_queue(struct rcu_head *head)
-{
-}
-
-static inline void debug_rcu_head_unqueue(struct rcu_head *head)
-{
-}
-#endif	/* #else !CONFIG_DEBUG_OBJECTS_RCU_HEAD */
-
 static __always_inline bool __is_kfree_rcu_offset(unsigned long offset)
 {
 	return offset < 4096;
@@ -827,18 +812,6 @@ void __kfree_rcu(struct rcu_head *head, unsigned long offset)
 	call_rcu(head, (rcu_callback)offset);
 }
 
-extern void kfree(const void *);
-
-static inline void __rcu_reclaim(struct rcu_head *head)
-{
-	unsigned long offset = (unsigned long)head->func;
-
-	if (__is_kfree_rcu_offset(offset))
-		kfree((void *)head - offset);
-	else
-		head->func(head);
-}
-
 /**
  * kfree_rcu() - kfree an object after a grace period.
  * @ptr:	pointer to kfree
diff --git a/include/linux/rcutiny.h b/include/linux/rcutiny.h
index 52b3e0281fd0..4eab233a00cd 100644
--- a/include/linux/rcutiny.h
+++ b/include/linux/rcutiny.h
@@ -31,6 +31,16 @@ static inline void rcu_init(void)
 {
 }
 
+static inline void rcu_barrier_bh(void)
+{
+	wait_rcu_gp(call_rcu_bh);
+}
+
+static inline void rcu_barrier_sched(void)
+{
+	wait_rcu_gp(call_rcu_sched);
+}
+
 #ifdef CONFIG_TINY_RCU
 
 static inline void synchronize_rcu_expedited(void)
@@ -45,9 +55,13 @@ static inline void rcu_barrier(void)
 
 #else /* #ifdef CONFIG_TINY_RCU */
 
-void rcu_barrier(void);
 void synchronize_rcu_expedited(void);
 
+static inline void rcu_barrier(void)
+{
+	wait_rcu_gp(call_rcu);
+}
+
 #endif /* #else #ifdef CONFIG_TINY_RCU */
 
 static inline void synchronize_rcu_bh(void)
diff --git a/include/linux/rcutree.h b/include/linux/rcutree.h
index e65d06634dd8..67458468f1a8 100644
--- a/include/linux/rcutree.h
+++ b/include/linux/rcutree.h
@@ -67,6 +67,8 @@ static inline void synchronize_rcu_bh_expedited(void)
 }
 
 extern void rcu_barrier(void);
+extern void rcu_barrier_bh(void);
+extern void rcu_barrier_sched(void);
 
 extern unsigned long rcutorture_testseq;
 extern unsigned long rcutorture_vernum;
diff --git a/include/linux/types.h b/include/linux/types.h
index 176da8c1fbb1..57a97234bec1 100644
--- a/include/linux/types.h
+++ b/include/linux/types.h
@@ -238,6 +238,16 @@ struct ustat {
 	char			f_fpack[6];
 };
 
+/**
+ * struct rcu_head - callback structure for use with RCU
+ * @next: next update requests in a list
+ * @func: actual update function to call after the grace period.
+ */
+struct rcu_head {
+	struct rcu_head *next;
+	void (*func)(struct rcu_head *head);
+};
+
 #endif	/* __KERNEL__ */
 #endif /*  __ASSEMBLY__ */
 #endif /* _LINUX_TYPES_H */
diff --git a/include/trace/events/rcu.h b/include/trace/events/rcu.h
new file mode 100644
index 000000000000..db3f6e9e63e6
--- /dev/null
+++ b/include/trace/events/rcu.h
@@ -0,0 +1,98 @@
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM rcu
+
+#if !defined(_TRACE_RCU_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _TRACE_RCU_H
+
+#include <linux/tracepoint.h>
+
+/*
+ * Tracepoint for calling rcu_do_batch, performed to start callback invocation:
+ */
+TRACE_EVENT(rcu_batch_start,
+
+	TP_PROTO(long callbacks_ready, int blimit),
+
+	TP_ARGS(callbacks_ready, blimit),
+
+	TP_STRUCT__entry(
+		__field(	long,	callbacks_ready		)
+		__field(	int,	blimit			)
+	),
+
+	TP_fast_assign(
+		__entry->callbacks_ready	= callbacks_ready;
+		__entry->blimit			= blimit;
+	),
+
+	TP_printk("CBs=%ld bl=%d", __entry->callbacks_ready, __entry->blimit)
+);
+
+/*
+ * Tracepoint for the invocation of a single RCU callback
+ */
+TRACE_EVENT(rcu_invoke_callback,
+
+	TP_PROTO(struct rcu_head *rhp),
+
+	TP_ARGS(rhp),
+
+	TP_STRUCT__entry(
+		__field(	void *,	rhp	)
+		__field(	void *,	func	)
+	),
+
+	TP_fast_assign(
+		__entry->rhp	= rhp;
+		__entry->func	= rhp->func;
+	),
+
+	TP_printk("rhp=%p func=%pf", __entry->rhp, __entry->func)
+);
+
+/*
+ * Tracepoint for the invocation of a single RCU kfree callback
+ */
+TRACE_EVENT(rcu_invoke_kfree_callback,
+
+	TP_PROTO(struct rcu_head *rhp, unsigned long offset),
+
+	TP_ARGS(rhp, offset),
+
+	TP_STRUCT__entry(
+		__field(void *,	rhp	)
+		__field(unsigned long,	offset	)
+	),
+
+	TP_fast_assign(
+		__entry->rhp	= rhp;
+		__entry->offset	= offset;
+	),
+
+	TP_printk("rhp=%p func=%ld", __entry->rhp, __entry->offset)
+);
+
+/*
+ * Tracepoint for leaving rcu_do_batch, performed after callback invocation:
+ */
+TRACE_EVENT(rcu_batch_end,
+
+	TP_PROTO(int callbacks_invoked),
+
+	TP_ARGS(callbacks_invoked),
+
+	TP_STRUCT__entry(
+		__field(	int,	callbacks_invoked		)
+	),
+
+	TP_fast_assign(
+		__entry->callbacks_invoked	= callbacks_invoked;
+	),
+
+	TP_printk("CBs-invoked=%d", __entry->callbacks_invoked)
+);
+
+#endif /* _TRACE_RCU_H */
+
+/* This part must be outside protection */
+#include <trace/define_trace.h>
diff --git a/init/Kconfig b/init/Kconfig
index e20aa3112240..1d6f317a919d 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -391,7 +391,7 @@ config TREE_RCU
 
 config TREE_PREEMPT_RCU
 	bool "Preemptible tree-based hierarchical RCU"
-	depends on PREEMPT
+	depends on PREEMPT && SMP
 	help
 	  This option selects the RCU implementation that is
 	  designed for very large SMP systems with hundreds or
@@ -401,7 +401,7 @@ config TREE_PREEMPT_RCU
 
 config TINY_RCU
 	bool "UP-only small-memory-footprint RCU"
-	depends on !SMP
+	depends on !PREEMPT && !SMP
 	help
 	  This option selects the RCU implementation that is
 	  designed for UP systems from which real-time response
@@ -410,7 +410,7 @@ config TINY_RCU
 
 config TINY_PREEMPT_RCU
 	bool "Preemptible UP-only small-memory-footprint RCU"
-	depends on !SMP && PREEMPT
+	depends on PREEMPT && !SMP
 	help
 	  This option selects the RCU implementation that is designed
 	  for real-time UP systems.  This option greatly reduces the
diff --git a/kernel/lockdep.c b/kernel/lockdep.c
index 298c9276dfdb..df2ad3727a8a 100644
--- a/kernel/lockdep.c
+++ b/kernel/lockdep.c
@@ -1129,10 +1129,11 @@ print_circular_bug_header(struct lock_list *entry, unsigned int depth,
 	if (debug_locks_silent)
 		return 0;
 
-	printk("\n=======================================================\n");
-	printk(  "[ INFO: possible circular locking dependency detected ]\n");
+	printk("\n");
+	printk("======================================================\n");
+	printk("[ INFO: possible circular locking dependency detected ]\n");
 	print_kernel_version();
-	printk(  "-------------------------------------------------------\n");
+	printk("-------------------------------------------------------\n");
 	printk("%s/%d is trying to acquire lock:\n",
 		curr->comm, task_pid_nr(curr));
 	print_lock(check_src);
@@ -1463,11 +1464,12 @@ print_bad_irq_dependency(struct task_struct *curr,
 	if (!debug_locks_off_graph_unlock() || debug_locks_silent)
 		return 0;
 
-	printk("\n======================================================\n");
-	printk(  "[ INFO: %s-safe -> %s-unsafe lock order detected ]\n",
+	printk("\n");
+	printk("======================================================\n");
+	printk("[ INFO: %s-safe -> %s-unsafe lock order detected ]\n",
 		irqclass, irqclass);
 	print_kernel_version();
-	printk(  "------------------------------------------------------\n");
+	printk("------------------------------------------------------\n");
 	printk("%s/%d [HC%u[%lu]:SC%u[%lu]:HE%u:SE%u] is trying to acquire:\n",
 		curr->comm, task_pid_nr(curr),
 		curr->hardirq_context, hardirq_count() >> HARDIRQ_SHIFT,
@@ -1692,10 +1694,11 @@ print_deadlock_bug(struct task_struct *curr, struct held_lock *prev,
 	if (!debug_locks_off_graph_unlock() || debug_locks_silent)
 		return 0;
 
-	printk("\n=============================================\n");
-	printk(  "[ INFO: possible recursive locking detected ]\n");
+	printk("\n");
+	printk("=============================================\n");
+	printk("[ INFO: possible recursive locking detected ]\n");
 	print_kernel_version();
-	printk(  "---------------------------------------------\n");
+	printk("---------------------------------------------\n");
 	printk("%s/%d is trying to acquire lock:\n",
 		curr->comm, task_pid_nr(curr));
 	print_lock(next);
@@ -2177,10 +2180,11 @@ print_usage_bug(struct task_struct *curr, struct held_lock *this,
 	if (!debug_locks_off_graph_unlock() || debug_locks_silent)
 		return 0;
 
-	printk("\n=================================\n");
-	printk(  "[ INFO: inconsistent lock state ]\n");
+	printk("\n");
+	printk("=================================\n");
+	printk("[ INFO: inconsistent lock state ]\n");
 	print_kernel_version();
-	printk(  "---------------------------------\n");
+	printk("---------------------------------\n");
 
 	printk("inconsistent {%s} -> {%s} usage.\n",
 		usage_str[prev_bit], usage_str[new_bit]);
@@ -2241,10 +2245,11 @@ print_irq_inversion_bug(struct task_struct *curr,
 	if (!debug_locks_off_graph_unlock() || debug_locks_silent)
 		return 0;
 
-	printk("\n=========================================================\n");
-	printk(  "[ INFO: possible irq lock inversion dependency detected ]\n");
+	printk("\n");
+	printk("=========================================================\n");
+	printk("[ INFO: possible irq lock inversion dependency detected ]\n");
 	print_kernel_version();
-	printk(  "---------------------------------------------------------\n");
+	printk("---------------------------------------------------------\n");
 	printk("%s/%d just changed the state of lock:\n",
 		curr->comm, task_pid_nr(curr));
 	print_lock(this);
@@ -3053,9 +3058,10 @@ print_unlock_inbalance_bug(struct task_struct *curr, struct lockdep_map *lock,
 	if (debug_locks_silent)
 		return 0;
 
-	printk("\n=====================================\n");
-	printk(  "[ BUG: bad unlock balance detected! ]\n");
-	printk(  "-------------------------------------\n");
+	printk("\n");
+	printk("=====================================\n");
+	printk("[ BUG: bad unlock balance detected! ]\n");
+	printk("-------------------------------------\n");
 	printk("%s/%d is trying to release lock (",
 		curr->comm, task_pid_nr(curr));
 	print_lockdep_cache(lock);
@@ -3460,9 +3466,10 @@ print_lock_contention_bug(struct task_struct *curr, struct lockdep_map *lock,
 	if (debug_locks_silent)
 		return 0;
 
-	printk("\n=================================\n");
-	printk(  "[ BUG: bad contention detected! ]\n");
-	printk(  "---------------------------------\n");
+	printk("\n");
+	printk("=================================\n");
+	printk("[ BUG: bad contention detected! ]\n");
+	printk("---------------------------------\n");
 	printk("%s/%d is trying to contend lock (",
 		curr->comm, task_pid_nr(curr));
 	print_lockdep_cache(lock);
@@ -3821,9 +3828,10 @@ print_freed_lock_bug(struct task_struct *curr, const void *mem_from,
 	if (debug_locks_silent)
 		return;
 
-	printk("\n=========================\n");
-	printk(  "[ BUG: held lock freed! ]\n");
-	printk(  "-------------------------\n");
+	printk("\n");
+	printk("=========================\n");
+	printk("[ BUG: held lock freed! ]\n");
+	printk("-------------------------\n");
 	printk("%s/%d is freeing memory %p-%p, with a lock still held there!\n",
 		curr->comm, task_pid_nr(curr), mem_from, mem_to-1);
 	print_lock(hlock);
@@ -3877,9 +3885,10 @@ static void print_held_locks_bug(struct task_struct *curr)
 	if (debug_locks_silent)
 		return;
 
-	printk("\n=====================================\n");
-	printk(  "[ BUG: lock held at task exit time! ]\n");
-	printk(  "-------------------------------------\n");
+	printk("\n");
+	printk("=====================================\n");
+	printk("[ BUG: lock held at task exit time! ]\n");
+	printk("-------------------------------------\n");
 	printk("%s/%d is exiting with locks still held!\n",
 		curr->comm, task_pid_nr(curr));
 	lockdep_print_held_locks(curr);
@@ -3973,16 +3982,17 @@ void lockdep_sys_exit(void)
 	if (unlikely(curr->lockdep_depth)) {
 		if (!debug_locks_off())
 			return;
-		printk("\n================================================\n");
-		printk(  "[ BUG: lock held when returning to user space! ]\n");
-		printk(  "------------------------------------------------\n");
+		printk("\n");
+		printk("================================================\n");
+		printk("[ BUG: lock held when returning to user space! ]\n");
+		printk("------------------------------------------------\n");
 		printk("%s/%d is leaving the kernel with locks still held!\n",
 				curr->comm, curr->pid);
 		lockdep_print_held_locks(curr);
 	}
 }
 
-void lockdep_rcu_dereference(const char *file, const int line)
+void lockdep_rcu_suspicious(const char *file, const int line, const char *s)
 {
 	struct task_struct *curr = current;
 
@@ -3991,15 +4001,15 @@ void lockdep_rcu_dereference(const char *file, const int line)
 		return;
 #endif /* #ifdef CONFIG_PROVE_RCU_REPEATEDLY */
 	/* Note: the following can be executed concurrently, so be careful. */
-	printk("\n===================================================\n");
-	printk(  "[ INFO: suspicious rcu_dereference_check() usage. ]\n");
-	printk(  "---------------------------------------------------\n");
-	printk("%s:%d invoked rcu_dereference_check() without protection!\n",
-			file, line);
+	printk("\n");
+	printk("===============================\n");
+	printk("[ INFO: suspicious RCU usage. ]\n");
+	printk("-------------------------------\n");
+	printk("%s:%d %s!\n", file, line, s);
 	printk("\nother info that might help us debug this:\n\n");
 	printk("\nrcu_scheduler_active = %d, debug_locks = %d\n", rcu_scheduler_active, debug_locks);
 	lockdep_print_held_locks(curr);
 	printk("\nstack backtrace:\n");
 	dump_stack();
 }
-EXPORT_SYMBOL_GPL(lockdep_rcu_dereference);
+EXPORT_SYMBOL_GPL(lockdep_rcu_suspicious);
diff --git a/kernel/pid.c b/kernel/pid.c
index 57a8346a270e..a7577b3887c6 100644
--- a/kernel/pid.c
+++ b/kernel/pid.c
@@ -419,7 +419,9 @@ EXPORT_SYMBOL(pid_task);
  */
 struct task_struct *find_task_by_pid_ns(pid_t nr, struct pid_namespace *ns)
 {
-	rcu_lockdep_assert(rcu_read_lock_held());
+	rcu_lockdep_assert(rcu_read_lock_held(),
+			   "find_task_by_pid_ns() needs rcu_read_lock()"
+			   " protection");
 	return pid_task(find_pid_ns(nr, ns), PIDTYPE_PID);
 }
 
diff --git a/kernel/rcu.h b/kernel/rcu.h
new file mode 100644
index 000000000000..7bc16436aba0
--- /dev/null
+++ b/kernel/rcu.h
@@ -0,0 +1,79 @@
+/*
+ * Read-Copy Update definitions shared among RCU implementations.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ *
+ * Copyright IBM Corporation, 2011
+ *
+ * Author: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
+ */
+
+#ifndef __LINUX_RCU_H
+#define __LINUX_RCU_H
+
+/*
+ * debug_rcu_head_queue()/debug_rcu_head_unqueue() are used internally
+ * by call_rcu() and rcu callback execution, and are therefore not part of the
+ * RCU API. Leaving in rcupdate.h because they are used by all RCU flavors.
+ */
+
+#ifdef CONFIG_DEBUG_OBJECTS_RCU_HEAD
+# define STATE_RCU_HEAD_READY	0
+# define STATE_RCU_HEAD_QUEUED	1
+
+extern struct debug_obj_descr rcuhead_debug_descr;
+
+static inline void debug_rcu_head_queue(struct rcu_head *head)
+{
+	WARN_ON_ONCE((unsigned long)head & 0x3);
+	debug_object_activate(head, &rcuhead_debug_descr);
+	debug_object_active_state(head, &rcuhead_debug_descr,
+				  STATE_RCU_HEAD_READY,
+				  STATE_RCU_HEAD_QUEUED);
+}
+
+static inline void debug_rcu_head_unqueue(struct rcu_head *head)
+{
+	debug_object_active_state(head, &rcuhead_debug_descr,
+				  STATE_RCU_HEAD_QUEUED,
+				  STATE_RCU_HEAD_READY);
+	debug_object_deactivate(head, &rcuhead_debug_descr);
+}
+#else	/* !CONFIG_DEBUG_OBJECTS_RCU_HEAD */
+static inline void debug_rcu_head_queue(struct rcu_head *head)
+{
+}
+
+static inline void debug_rcu_head_unqueue(struct rcu_head *head)
+{
+}
+#endif	/* #else !CONFIG_DEBUG_OBJECTS_RCU_HEAD */
+
+extern void kfree(const void *);
+
+static inline void __rcu_reclaim(struct rcu_head *head)
+{
+	unsigned long offset = (unsigned long)head->func;
+
+	if (__is_kfree_rcu_offset(offset)) {
+		trace_rcu_invoke_kfree_callback(head, offset);
+		kfree((void *)head - offset);
+	} else {
+		trace_rcu_invoke_callback(head);
+		head->func(head);
+	}
+}
+
+#endif /* __LINUX_RCU_H */
diff --git a/kernel/rcupdate.c b/kernel/rcupdate.c
index 7784bd216b6a..5031cafb6f8a 100644
--- a/kernel/rcupdate.c
+++ b/kernel/rcupdate.c
@@ -46,6 +46,11 @@
 #include <linux/module.h>
 #include <linux/hardirq.h>
 
+#define CREATE_TRACE_POINTS
+#include <trace/events/rcu.h>
+
+#include "rcu.h"
+
 #ifdef CONFIG_DEBUG_LOCK_ALLOC
 static struct lock_class_key rcu_lock_key;
 struct lockdep_map rcu_lock_map =
@@ -94,11 +99,16 @@ EXPORT_SYMBOL_GPL(rcu_read_lock_bh_held);
 
 #endif /* #ifdef CONFIG_DEBUG_LOCK_ALLOC */
 
+struct rcu_synchronize {
+	struct rcu_head head;
+	struct completion completion;
+};
+
 /*
  * Awaken the corresponding synchronize_rcu() instance now that a
  * grace period has elapsed.
  */
-void wakeme_after_rcu(struct rcu_head  *head)
+static void wakeme_after_rcu(struct rcu_head  *head)
 {
 	struct rcu_synchronize *rcu;
 
@@ -106,6 +116,20 @@ void wakeme_after_rcu(struct rcu_head  *head)
 	complete(&rcu->completion);
 }
 
+void wait_rcu_gp(call_rcu_func_t crf)
+{
+	struct rcu_synchronize rcu;
+
+	init_rcu_head_on_stack(&rcu.head);
+	init_completion(&rcu.completion);
+	/* Will wake me after RCU finished. */
+	crf(&rcu.head, wakeme_after_rcu);
+	/* Wait for it. */
+	wait_for_completion(&rcu.completion);
+	destroy_rcu_head_on_stack(&rcu.head);
+}
+EXPORT_SYMBOL_GPL(wait_rcu_gp);
+
 #ifdef CONFIG_PROVE_RCU
 /*
  * wrapper function to avoid #include problems.
diff --git a/kernel/rcutiny.c b/kernel/rcutiny.c
index 7bbac7d0f5ab..19453ba1392e 100644
--- a/kernel/rcutiny.c
+++ b/kernel/rcutiny.c
@@ -37,6 +37,25 @@
 #include <linux/cpu.h>
 #include <linux/prefetch.h>
 
+#ifdef CONFIG_RCU_TRACE
+
+#include <trace/events/rcu.h>
+
+#else /* #ifdef CONFIG_RCU_TRACE */
+
+/* No by-default tracing in TINY_RCU: Keep TINY_RCU tiny! */
+static void trace_rcu_invoke_kfree_callback(struct rcu_head *rhp,
+					    unsigned long offset)
+{
+}
+static void trace_rcu_invoke_callback(struct rcu_head *head)
+{
+}
+
+#endif /* #else #ifdef CONFIG_RCU_TRACE */
+
+#include "rcu.h"
+
 /* Controls for rcu_kthread() kthread, replacing RCU_SOFTIRQ used previously. */
 static struct task_struct *rcu_kthread_task;
 static DECLARE_WAIT_QUEUE_HEAD(rcu_kthread_wq);
@@ -161,11 +180,15 @@ static void rcu_process_callbacks(struct rcu_ctrlblk *rcp)
 	RCU_TRACE(int cb_count = 0);
 
 	/* If no RCU callbacks ready to invoke, just return. */
-	if (&rcp->rcucblist == rcp->donetail)
+	if (&rcp->rcucblist == rcp->donetail) {
+		RCU_TRACE(trace_rcu_batch_start(0, -1));
+		RCU_TRACE(trace_rcu_batch_end(0));
 		return;
+	}
 
 	/* Move the ready-to-invoke callbacks to a local list. */
 	local_irq_save(flags);
+	RCU_TRACE(trace_rcu_batch_start(0, -1));
 	list = rcp->rcucblist;
 	rcp->rcucblist = *rcp->donetail;
 	*rcp->donetail = NULL;
@@ -187,6 +210,7 @@ static void rcu_process_callbacks(struct rcu_ctrlblk *rcp)
 		RCU_TRACE(cb_count++);
 	}
 	RCU_TRACE(rcu_trace_sub_qlen(rcp, cb_count));
+	RCU_TRACE(trace_rcu_batch_end(cb_count));
 }
 
 /*
@@ -281,34 +305,6 @@ void call_rcu_bh(struct rcu_head *head, void (*func)(struct rcu_head *rcu))
 }
 EXPORT_SYMBOL_GPL(call_rcu_bh);
 
-void rcu_barrier_bh(void)
-{
-	struct rcu_synchronize rcu;
-
-	init_rcu_head_on_stack(&rcu.head);
-	init_completion(&rcu.completion);
-	/* Will wake me after RCU finished. */
-	call_rcu_bh(&rcu.head, wakeme_after_rcu);
-	/* Wait for it. */
-	wait_for_completion(&rcu.completion);
-	destroy_rcu_head_on_stack(&rcu.head);
-}
-EXPORT_SYMBOL_GPL(rcu_barrier_bh);
-
-void rcu_barrier_sched(void)
-{
-	struct rcu_synchronize rcu;
-
-	init_rcu_head_on_stack(&rcu.head);
-	init_completion(&rcu.completion);
-	/* Will wake me after RCU finished. */
-	call_rcu_sched(&rcu.head, wakeme_after_rcu);
-	/* Wait for it. */
-	wait_for_completion(&rcu.completion);
-	destroy_rcu_head_on_stack(&rcu.head);
-}
-EXPORT_SYMBOL_GPL(rcu_barrier_sched);
-
 /*
  * Spawn the kthread that invokes RCU callbacks.
  */
diff --git a/kernel/rcutiny_plugin.h b/kernel/rcutiny_plugin.h
index f259c676195f..6b0cedb383e0 100644
--- a/kernel/rcutiny_plugin.h
+++ b/kernel/rcutiny_plugin.h
@@ -697,20 +697,6 @@ void call_rcu(struct rcu_head *head, void (*func)(struct rcu_head *rcu))
 }
 EXPORT_SYMBOL_GPL(call_rcu);
 
-void rcu_barrier(void)
-{
-	struct rcu_synchronize rcu;
-
-	init_rcu_head_on_stack(&rcu.head);
-	init_completion(&rcu.completion);
-	/* Will wake me after RCU finished. */
-	call_rcu(&rcu.head, wakeme_after_rcu);
-	/* Wait for it. */
-	wait_for_completion(&rcu.completion);
-	destroy_rcu_head_on_stack(&rcu.head);
-}
-EXPORT_SYMBOL_GPL(rcu_barrier);
-
 /*
  * synchronize_rcu - wait until a grace period has elapsed.
  *
diff --git a/kernel/rcutorture.c b/kernel/rcutorture.c
index 2e138db03382..e0f39ea27d63 100644
--- a/kernel/rcutorture.c
+++ b/kernel/rcutorture.c
@@ -480,30 +480,6 @@ static void rcu_bh_torture_deferred_free(struct rcu_torture *p)
 	call_rcu_bh(&p->rtort_rcu, rcu_torture_cb);
 }
 
-struct rcu_bh_torture_synchronize {
-	struct rcu_head head;
-	struct completion completion;
-};
-
-static void rcu_bh_torture_wakeme_after_cb(struct rcu_head *head)
-{
-	struct rcu_bh_torture_synchronize *rcu;
-
-	rcu = container_of(head, struct rcu_bh_torture_synchronize, head);
-	complete(&rcu->completion);
-}
-
-static void rcu_bh_torture_synchronize(void)
-{
-	struct rcu_bh_torture_synchronize rcu;
-
-	init_rcu_head_on_stack(&rcu.head);
-	init_completion(&rcu.completion);
-	call_rcu_bh(&rcu.head, rcu_bh_torture_wakeme_after_cb);
-	wait_for_completion(&rcu.completion);
-	destroy_rcu_head_on_stack(&rcu.head);
-}
-
 static struct rcu_torture_ops rcu_bh_ops = {
 	.init		= NULL,
 	.cleanup	= NULL,
@@ -512,7 +488,7 @@ static struct rcu_torture_ops rcu_bh_ops = {
 	.readunlock	= rcu_bh_torture_read_unlock,
 	.completed	= rcu_bh_torture_completed,
 	.deferred_free	= rcu_bh_torture_deferred_free,
-	.sync		= rcu_bh_torture_synchronize,
+	.sync		= synchronize_rcu_bh,
 	.cb_barrier	= rcu_barrier_bh,
 	.fqs		= rcu_bh_force_quiescent_state,
 	.stats		= NULL,
@@ -528,7 +504,7 @@ static struct rcu_torture_ops rcu_bh_sync_ops = {
 	.readunlock	= rcu_bh_torture_read_unlock,
 	.completed	= rcu_bh_torture_completed,
 	.deferred_free	= rcu_sync_torture_deferred_free,
-	.sync		= rcu_bh_torture_synchronize,
+	.sync		= synchronize_rcu_bh,
 	.cb_barrier	= NULL,
 	.fqs		= rcu_bh_force_quiescent_state,
 	.stats		= NULL,
@@ -536,6 +512,22 @@ static struct rcu_torture_ops rcu_bh_sync_ops = {
 	.name		= "rcu_bh_sync"
 };
 
+static struct rcu_torture_ops rcu_bh_expedited_ops = {
+	.init		= rcu_sync_torture_init,
+	.cleanup	= NULL,
+	.readlock	= rcu_bh_torture_read_lock,
+	.read_delay	= rcu_read_delay,  /* just reuse rcu's version. */
+	.readunlock	= rcu_bh_torture_read_unlock,
+	.completed	= rcu_bh_torture_completed,
+	.deferred_free	= rcu_sync_torture_deferred_free,
+	.sync		= synchronize_rcu_bh_expedited,
+	.cb_barrier	= NULL,
+	.fqs		= rcu_bh_force_quiescent_state,
+	.stats		= NULL,
+	.irq_capable	= 1,
+	.name		= "rcu_bh_expedited"
+};
+
 /*
  * Definitions for srcu torture testing.
  */
@@ -659,11 +651,6 @@ static void rcu_sched_torture_deferred_free(struct rcu_torture *p)
 	call_rcu_sched(&p->rtort_rcu, rcu_torture_cb);
 }
 
-static void sched_torture_synchronize(void)
-{
-	synchronize_sched();
-}
-
 static struct rcu_torture_ops sched_ops = {
 	.init		= rcu_sync_torture_init,
 	.cleanup	= NULL,
@@ -672,7 +659,7 @@ static struct rcu_torture_ops sched_ops = {
 	.readunlock	= sched_torture_read_unlock,
 	.completed	= rcu_no_completed,
 	.deferred_free	= rcu_sched_torture_deferred_free,
-	.sync		= sched_torture_synchronize,
+	.sync		= synchronize_sched,
 	.cb_barrier	= rcu_barrier_sched,
 	.fqs		= rcu_sched_force_quiescent_state,
 	.stats		= NULL,
@@ -688,7 +675,7 @@ static struct rcu_torture_ops sched_sync_ops = {
 	.readunlock	= sched_torture_read_unlock,
 	.completed	= rcu_no_completed,
 	.deferred_free	= rcu_sync_torture_deferred_free,
-	.sync		= sched_torture_synchronize,
+	.sync		= synchronize_sched,
 	.cb_barrier	= NULL,
 	.fqs		= rcu_sched_force_quiescent_state,
 	.stats		= NULL,
@@ -1282,8 +1269,9 @@ static int rcutorture_booster_init(int cpu)
 	/* Don't allow time recalculation while creating a new task. */
 	mutex_lock(&boost_mutex);
 	VERBOSE_PRINTK_STRING("Creating rcu_torture_boost task");
-	boost_tasks[cpu] = kthread_create(rcu_torture_boost, NULL,
-					  "rcu_torture_boost");
+	boost_tasks[cpu] = kthread_create_on_node(rcu_torture_boost, NULL,
+						  cpu_to_node(cpu),
+						  "rcu_torture_boost");
 	if (IS_ERR(boost_tasks[cpu])) {
 		retval = PTR_ERR(boost_tasks[cpu]);
 		VERBOSE_PRINTK_STRING("rcu_torture_boost task create failed");
@@ -1426,7 +1414,7 @@ rcu_torture_init(void)
 	int firsterr = 0;
 	static struct rcu_torture_ops *torture_ops[] =
 		{ &rcu_ops, &rcu_sync_ops, &rcu_expedited_ops,
-		  &rcu_bh_ops, &rcu_bh_sync_ops,
+		  &rcu_bh_ops, &rcu_bh_sync_ops, &rcu_bh_expedited_ops,
 		  &srcu_ops, &srcu_expedited_ops,
 		  &sched_ops, &sched_sync_ops, &sched_expedited_ops, };
 
diff --git a/kernel/rcutree.c b/kernel/rcutree.c
index 7e59ffb3d0ba..753bf1dd4eec 100644
--- a/kernel/rcutree.c
+++ b/kernel/rcutree.c
@@ -52,6 +52,9 @@
 #include <linux/prefetch.h>
 
 #include "rcutree.h"
+#include <trace/events/rcu.h>
+
+#include "rcu.h"
 
 /* Data structures. */
 
@@ -484,6 +487,56 @@ static int rcu_implicit_dynticks_qs(struct rcu_data *rdp)
 
 #endif /* #ifdef CONFIG_SMP */
 
+#ifdef CONFIG_32BIT
+
+/*
+ * Wrapper function to allow smp_call_function_single() to invoke RCU
+ * core processing on some other CPU.
+ */
+static void invoke_rcu_core_remote(void *unused)
+{
+	invoke_rcu_cpu_kthread();
+}
+
+/*
+ * Check a CPU to see if it is online, in dyntick-idle mode, and
+ * in danger of being too far behind the current grace period.
+ * If so, wake it up so as to make it catch up to the current
+ * grace period.  On a 32-bit system running through 500 grace
+ * periods per second, a given CPU would be awakened about once
+ * every 50 days.  On a 64-bit system, a given CPU would be
+ * awakened about every 500 million years, so we don't bother
+ * in that case.  If you happen to be manufacturing an extremely
+ * durable 64-bit SMP computer system, obtain a patch from the
+ * RCU maintainer.
+ */
+static void rcu_dyntick_kick_cpu(struct rcu_state *rsp)
+{
+	int cpu;
+	struct rcu_data *rdp;
+
+	cpu = rsp->dyntick_ovf_cpu;
+	rdp = per_cpu_ptr(rsp->rda, cpu);
+	if (cpu_online(cpu) && ULONG_CMP_LT(rsp->completed, rdp->completed))
+		if (smp_processor_id() == cpu)
+			invoke_rcu_cpu_kthread();
+		else
+			smp_call_function_single(cpu, invoke_rcu_core_remote,
+						 NULL, 1);
+	cpu = next_cpu(cpu, cpu_online_mask);
+	if (cpu >= NR_CPUS)
+		cpu = first_cpu(cpu_online_mask);
+	rsp->dyntick_ovf_cpu = cpu;
+}
+
+#else /* #ifdef CONFIG_32BIT */
+
+static void rcu_dyntick_kick_cpu(struct rcu_state *rsp)
+{
+}
+
+#endif /* #else #ifdef CONFIG_32BIT */
+
 #else /* #ifdef CONFIG_NO_HZ */
 
 #ifdef CONFIG_SMP
@@ -500,6 +553,10 @@ static int rcu_implicit_dynticks_qs(struct rcu_data *rdp)
 
 #endif /* #ifdef CONFIG_SMP */
 
+static void rcu_dyntick_kick_cpu(struct rcu_state *rsp)
+{
+}
+
 #endif /* #else #ifdef CONFIG_NO_HZ */
 
 int rcu_cpu_stall_suppress __read_mostly;
@@ -833,6 +890,7 @@ rcu_start_gp(struct rcu_state *rsp, unsigned long flags)
 	rsp->signaled = RCU_GP_INIT; /* Hold off force_quiescent_state. */
 	rsp->jiffies_force_qs = jiffies + RCU_JIFFIES_TILL_FORCE_QS;
 	record_gp_stall_check_time(rsp);
+	rcu_dyntick_kick_cpu(rsp);
 
 	/* Special-case the common single-level case. */
 	if (NUM_RCU_NODES == 1) {
@@ -1168,17 +1226,22 @@ static void rcu_do_batch(struct rcu_state *rsp, struct rcu_data *rdp)
 {
 	unsigned long flags;
 	struct rcu_head *next, *list, **tail;
-	int count;
+	int bl, count;
 
 	/* If no callbacks are ready, just return.*/
-	if (!cpu_has_callbacks_ready_to_invoke(rdp))
+	if (!cpu_has_callbacks_ready_to_invoke(rdp)) {
+		trace_rcu_batch_start(0, 0);
+		trace_rcu_batch_end(0);
 		return;
+	}
 
 	/*
 	 * Extract the list of ready callbacks, disabling to prevent
 	 * races with call_rcu() from interrupt handlers.
 	 */
 	local_irq_save(flags);
+	bl = rdp->blimit;
+	trace_rcu_batch_start(rdp->qlen, bl);
 	list = rdp->nxtlist;
 	rdp->nxtlist = *rdp->nxttail[RCU_DONE_TAIL];
 	*rdp->nxttail[RCU_DONE_TAIL] = NULL;
@@ -1196,11 +1259,12 @@ static void rcu_do_batch(struct rcu_state *rsp, struct rcu_data *rdp)
 		debug_rcu_head_unqueue(list);
 		__rcu_reclaim(list);
 		list = next;
-		if (++count >= rdp->blimit)
+		if (++count >= bl)
 			break;
 	}
 
 	local_irq_save(flags);
+	trace_rcu_batch_end(count);
 
 	/* Update count, and requeue any remaining callbacks. */
 	rdp->qlen -= count;
@@ -1589,18 +1653,9 @@ EXPORT_SYMBOL_GPL(call_rcu_bh);
  */
 void synchronize_sched(void)
 {
-	struct rcu_synchronize rcu;
-
 	if (rcu_blocking_is_gp())
 		return;
-
-	init_rcu_head_on_stack(&rcu.head);
-	init_completion(&rcu.completion);
-	/* Will wake me after RCU finished. */
-	call_rcu_sched(&rcu.head, wakeme_after_rcu);
-	/* Wait for it. */
-	wait_for_completion(&rcu.completion);
-	destroy_rcu_head_on_stack(&rcu.head);
+	wait_rcu_gp(call_rcu_sched);
 }
 EXPORT_SYMBOL_GPL(synchronize_sched);
 
@@ -1615,18 +1670,9 @@ EXPORT_SYMBOL_GPL(synchronize_sched);
  */
 void synchronize_rcu_bh(void)
 {
-	struct rcu_synchronize rcu;
-
 	if (rcu_blocking_is_gp())
 		return;
-
-	init_rcu_head_on_stack(&rcu.head);
-	init_completion(&rcu.completion);
-	/* Will wake me after RCU finished. */
-	call_rcu_bh(&rcu.head, wakeme_after_rcu);
-	/* Wait for it. */
-	wait_for_completion(&rcu.completion);
-	destroy_rcu_head_on_stack(&rcu.head);
+	wait_rcu_gp(call_rcu_bh);
 }
 EXPORT_SYMBOL_GPL(synchronize_rcu_bh);
 
diff --git a/kernel/rcutree.h b/kernel/rcutree.h
index 01b2ccda26fb..186d3a3e33e3 100644
--- a/kernel/rcutree.h
+++ b/kernel/rcutree.h
@@ -372,6 +372,10 @@ struct rcu_state {
 	u8	boost;				/* Subject to priority boost. */
 	unsigned long gpnum;			/* Current gp number. */
 	unsigned long completed;		/* # of last completed gp. */
+#ifdef CONFIG_NO_HZ
+	int dyntick_ovf_cpu;			/* Next CPU to poke if in */
+						/*  danger of GP overflow. */
+#endif /* #ifdef CONFIG_NO_HZ */
 
 	/* End of fields guarded by root rcu_node's lock. */
 
diff --git a/kernel/rcutree_plugin.h b/kernel/rcutree_plugin.h
index 14dc7dd00902..a53b4256b42a 100644
--- a/kernel/rcutree_plugin.h
+++ b/kernel/rcutree_plugin.h
@@ -284,7 +284,7 @@ static struct list_head *rcu_next_node_entry(struct task_struct *t,
  * notify RCU core processing or task having blocked during the RCU
  * read-side critical section.
  */
-static void rcu_read_unlock_special(struct task_struct *t)
+static noinline void rcu_read_unlock_special(struct task_struct *t)
 {
 	int empty;
 	int empty_exp;
@@ -387,11 +387,11 @@ void __rcu_read_unlock(void)
 	struct task_struct *t = current;
 
 	barrier();  /* needed if we ever invoke rcu_read_unlock in rcutree.c */
-	--t->rcu_read_lock_nesting;
-	barrier();  /* decrement before load of ->rcu_read_unlock_special */
-	if (t->rcu_read_lock_nesting == 0 &&
-	    unlikely(ACCESS_ONCE(t->rcu_read_unlock_special)))
-		rcu_read_unlock_special(t);
+	if (--t->rcu_read_lock_nesting == 0) {
+		barrier();  /* decr before ->rcu_read_unlock_special load */
+		if (unlikely(ACCESS_ONCE(t->rcu_read_unlock_special)))
+			rcu_read_unlock_special(t);
+	}
 #ifdef CONFIG_PROVE_LOCKING
 	WARN_ON_ONCE(ACCESS_ONCE(t->rcu_read_lock_nesting) < 0);
 #endif /* #ifdef CONFIG_PROVE_LOCKING */
@@ -633,18 +633,9 @@ EXPORT_SYMBOL_GPL(call_rcu);
  */
 void synchronize_rcu(void)
 {
-	struct rcu_synchronize rcu;
-
 	if (!rcu_scheduler_active)
 		return;
-
-	init_rcu_head_on_stack(&rcu.head);
-	init_completion(&rcu.completion);
-	/* Will wake me after RCU finished. */
-	call_rcu(&rcu.head, wakeme_after_rcu);
-	/* Wait for it. */
-	wait_for_completion(&rcu.completion);
-	destroy_rcu_head_on_stack(&rcu.head);
+	wait_rcu_gp(call_rcu);
 }
 EXPORT_SYMBOL_GPL(synchronize_rcu);
 
@@ -1266,11 +1257,9 @@ static void invoke_rcu_callbacks_kthread(void)
 
 	local_irq_save(flags);
 	__this_cpu_write(rcu_cpu_has_work, 1);
-	if (__this_cpu_read(rcu_cpu_kthread_task) == NULL) {
-		local_irq_restore(flags);
-		return;
-	}
-	wake_up_process(__this_cpu_read(rcu_cpu_kthread_task));
+	if (__this_cpu_read(rcu_cpu_kthread_task) != NULL &&
+	    current != __this_cpu_read(rcu_cpu_kthread_task))
+		wake_up_process(__this_cpu_read(rcu_cpu_kthread_task));
 	local_irq_restore(flags);
 }
 
@@ -1535,7 +1524,10 @@ static int __cpuinit rcu_spawn_one_cpu_kthread(int cpu)
 	if (!rcu_kthreads_spawnable ||
 	    per_cpu(rcu_cpu_kthread_task, cpu) != NULL)
 		return 0;
-	t = kthread_create(rcu_cpu_kthread, (void *)(long)cpu, "rcuc%d", cpu);
+	t = kthread_create_on_node(rcu_cpu_kthread,
+				   (void *)(long)cpu,
+				   cpu_to_node(cpu),
+				   "rcuc%d", cpu);
 	if (IS_ERR(t))
 		return PTR_ERR(t);
 	if (cpu_online(cpu))
diff --git a/kernel/rcutree_trace.c b/kernel/rcutree_trace.c
index 4e144876dc68..dc052249cba2 100644
--- a/kernel/rcutree_trace.c
+++ b/kernel/rcutree_trace.c
@@ -49,7 +49,7 @@
 #ifdef CONFIG_RCU_BOOST
 
 DECLARE_PER_CPU(unsigned int, rcu_cpu_kthread_status);
-DECLARE_PER_CPU(unsigned int, rcu_cpu_kthread_cpu);
+DECLARE_PER_CPU(int, rcu_cpu_kthread_cpu);
 DECLARE_PER_CPU(unsigned int, rcu_cpu_kthread_loops);
 DECLARE_PER_CPU(char, rcu_cpu_has_work);
 
@@ -282,13 +282,17 @@ static void print_one_rcu_state(struct seq_file *m, struct rcu_state *rsp)
 
 	gpnum = rsp->gpnum;
 	seq_printf(m, "c=%lu g=%lu s=%d jfq=%ld j=%x "
-		      "nfqs=%lu/nfqsng=%lu(%lu) fqlh=%lu\n",
+		      "nfqs=%lu/nfqsng=%lu(%lu) fqlh=%lu",
 		   rsp->completed, gpnum, rsp->signaled,
 		   (long)(rsp->jiffies_force_qs - jiffies),
 		   (int)(jiffies & 0xffff),
 		   rsp->n_force_qs, rsp->n_force_qs_ngp,
 		   rsp->n_force_qs - rsp->n_force_qs_ngp,
 		   rsp->n_force_qs_lh);
+#ifdef CONFIG_NO_HZ
+	seq_printf(m, " dovf=%d", rsp->dyntick_ovf_cpu);
+#endif /* #ifdef CONFIG_NO_HZ */
+	seq_printf(m, "\n");
 	for (rnp = &rsp->node[0]; rnp - &rsp->node[0] < NUM_RCU_NODES; rnp++) {
 		if (rnp->level != level) {
 			seq_puts(m, "\n");
diff --git a/kernel/sched.c b/kernel/sched.c
index 59252754fbe0..645c8022bc4b 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -4168,6 +4168,7 @@ static inline void schedule_debug(struct task_struct *prev)
 	 */
 	if (unlikely(in_atomic_preempt_off() && !prev->exit_state))
 		__schedule_bug(prev);
+	rcu_sleep_check();
 
 	profile_hit(SCHED_PROFILING, __builtin_return_address(0));
 
@@ -8042,6 +8043,7 @@ void __might_sleep(const char *file, int line, int preempt_offset)
 #ifdef in_atomic
 	static unsigned long prev_jiffy;	/* ratelimiting */
 
+	rcu_sleep_check(); /* WARN_ON_ONCE() by default, no rate limit reqd. */
 	if ((preempt_count_equals(preempt_offset) && !irqs_disabled()) ||
 	    system_state != SYSTEM_RUNNING || oops_in_progress)
 		return;
diff --git a/security/device_cgroup.c b/security/device_cgroup.c
index 1be68269e1c2..4450fbeec411 100644
--- a/security/device_cgroup.c
+++ b/security/device_cgroup.c
@@ -125,14 +125,6 @@ static int dev_whitelist_add(struct dev_cgroup *dev_cgroup,
 	return 0;
 }
 
-static void whitelist_item_free(struct rcu_head *rcu)
-{
-	struct dev_whitelist_item *item;
-
-	item = container_of(rcu, struct dev_whitelist_item, rcu);
-	kfree(item);
-}
-
 /*
  * called under devcgroup_mutex
  */
@@ -155,7 +147,7 @@ remove:
 		walk->access &= ~wh->access;
 		if (!walk->access) {
 			list_del_rcu(&walk->list);
-			call_rcu(&walk->rcu, whitelist_item_free);
+			kfree_rcu(walk, rcu);
 		}
 	}
 }