Merge branch 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (52 commits)
  sched: fix RCU lockdep splat from task_group()
  rcu: using ACCESS_ONCE() to observe the jiffies_stall/rnp->qsmask value
  sched: suppress RCU lockdep splat in task_fork_fair
  net: suppress RCU lockdep false positive in sock_update_classid
  rcu: move check from rcu_dereference_bh to rcu_read_lock_bh_held
  rcu: Add advice to PROVE_RCU_REPEATEDLY kernel config parameter
  rcu: Add tracing data to support queueing models
  rcu: fix sparse errors in rcutorture.c
  rcu: only one evaluation of arg in rcu_dereference_check() unless sparse
  kernel: Remove undead ifdef CONFIG_DEBUG_LOCK_ALLOC
  rcu: fix _oddness handling of verbose stall warnings
  rcu: performance fixes to TINY_PREEMPT_RCU callback checking
  rcu: upgrade stallwarn.txt documentation for CPU-bound RT processes
  vhost: add __rcu annotations
  rcu: add comment stating that list_empty() applies to RCU-protected lists
  rcu: apply TINY_PREEMPT_RCU read-side speedup to TREE_PREEMPT_RCU
  rcu: combine duplicate code, courtesy of CONFIG_PREEMPT_RCU
  rcu: Upgrade srcu_read_lock() docbook about SRCU grace periods
  rcu: document ways of stalling updates in low-memory situations
  rcu: repair code-duplication FIXMEs
  ...

1 files changed, 14 insertions, 6 deletions

diff --git a/kernel/rcutree.h b/kernel/rcutree.h
index 14c040b18ed0..91d4170c5c13 100644
--- a/kernel/rcutree.h
+++ b/kernel/rcutree.h
@@ -202,6 +202,9 @@ struct rcu_data {
 	long		qlen;		/* # of queued callbacks */
 	long		qlen_last_fqs_check;
 					/* qlen at last check for QS forcing */
+	unsigned long	n_cbs_invoked;	/* count of RCU cbs invoked. */
+	unsigned long	n_cbs_orphaned;	/* RCU cbs sent to orphanage. */
+	unsigned long	n_cbs_adopted;	/* RCU cbs adopted from orphanage. */
 	unsigned long	n_force_qs_snap;
 					/* did other CPU force QS recently? */
 	long		blimit;		/* Upper limit on a processed batch */
@@ -254,19 +257,23 @@ struct rcu_data {
 #define RCU_STALL_DELAY_DELTA	       0
 #endif
 
-#define RCU_SECONDS_TILL_STALL_CHECK   (10 * HZ + RCU_STALL_DELAY_DELTA)
+#define RCU_SECONDS_TILL_STALL_CHECK   (CONFIG_RCU_CPU_STALL_TIMEOUT * HZ + \
+					RCU_STALL_DELAY_DELTA)
 						/* for rsp->jiffies_stall */
-#define RCU_SECONDS_TILL_STALL_RECHECK (30 * HZ + RCU_STALL_DELAY_DELTA)
+#define RCU_SECONDS_TILL_STALL_RECHECK (3 * RCU_SECONDS_TILL_STALL_CHECK + 30)
 						/* for rsp->jiffies_stall */
 #define RCU_STALL_RAT_DELAY		2	/* Allow other CPUs time */
 						/*  to take at least one */
 						/*  scheduling clock irq */
 						/*  before ratting on them. */
 
-#endif /* #ifdef CONFIG_RCU_CPU_STALL_DETECTOR */
+#ifdef CONFIG_RCU_CPU_STALL_DETECTOR_RUNNABLE
+#define RCU_CPU_STALL_SUPPRESS_INIT 0
+#else
+#define RCU_CPU_STALL_SUPPRESS_INIT 1
+#endif
 
-#define ULONG_CMP_GE(a, b)	(ULONG_MAX / 2 >= (a) - (b))
-#define ULONG_CMP_LT(a, b)	(ULONG_MAX / 2 < (a) - (b))
+#endif /* #ifdef CONFIG_RCU_CPU_STALL_DETECTOR */
 
 /*
  * RCU global state, including node hierarchy.  This hierarchy is
@@ -283,7 +290,7 @@ struct rcu_state {
 	struct rcu_node *level[NUM_RCU_LVLS];	/* Hierarchy levels. */
 	u32 levelcnt[MAX_RCU_LVLS + 1];		/* # nodes in each level. */
 	u8 levelspread[NUM_RCU_LVLS];		/* kids/node in each level. */
-	struct rcu_data *rda[NR_CPUS];		/* array of rdp pointers. */
+	struct rcu_data __percpu *rda;		/* pointer of percu rcu_data. */
 
 	/* The following fields are guarded by the root rcu_node's lock. */
 
@@ -365,6 +372,7 @@ static void rcu_report_unblock_qs_rnp(struct rcu_node *rnp,
 #ifdef CONFIG_RCU_CPU_STALL_DETECTOR
 static void rcu_print_detail_task_stall(struct rcu_state *rsp);
 static void rcu_print_task_stall(struct rcu_node *rnp);
+static void rcu_preempt_stall_reset(void);
 #endif /* #ifdef CONFIG_RCU_CPU_STALL_DETECTOR */
 static void rcu_preempt_check_blocked_tasks(struct rcu_node *rnp);
 #ifdef CONFIG_HOTPLUG_CPU