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

* 'rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  rcu: rcu_sched_grace_period(): kill the bogus flush_signals()
  rculist: use list_entry_rcu in places where it's appropriate
  rculist.h: introduce list_entry_rcu() and list_first_entry_rcu()
  rcu: Update RCU tracing documentation for __rcu_pending
  rcu: Add __rcu_pending tracing to hierarchical RCU
  RCU: make treercu be default

3 files changed, 41 insertions, 6 deletions

diff --git a/include/linux/rculist.h b/include/linux/rculist.h
index e649bd3f2c97..5710f43bbc9e 100644
--- a/include/linux/rculist.h
+++ b/include/linux/rculist.h
@@ -198,6 +198,32 @@ static inline void list_splice_init_rcu(struct list_head *list,
         at->prev = last;
 }
 
+/**
+ * list_entry_rcu - get the struct for this entry
+ * @ptr:        the &struct list_head pointer.
+ * @type:       the type of the struct this is embedded in.
+ * @member:     the name of the list_struct within the struct.
+ *
+ * This primitive may safely run concurrently with the _rcu list-mutation
+ * primitives such as list_add_rcu() as long as it's guarded by rcu_read_lock().
+ */
+#define list_entry_rcu(ptr, type, member) \
+        container_of(rcu_dereference(ptr), type, member)
+
+/**
+ * list_first_entry_rcu - get the first element from a list
+ * @ptr:        the list head to take the element from.
+ * @type:       the type of the struct this is embedded in.
+ * @member:     the name of the list_struct within the struct.
+ *
+ * Note, that list is expected to be not empty.
+ *
+ * This primitive may safely run concurrently with the _rcu list-mutation
+ * primitives such as list_add_rcu() as long as it's guarded by rcu_read_lock().
+ */
+#define list_first_entry_rcu(ptr, type, member) \
+        list_entry_rcu((ptr)->next, type, member)
+
 #define __list_for_each_rcu(pos, head) \
         for (pos = rcu_dereference((head)->next); \
                 pos != (head); \
@@ -214,9 +240,9 @@ static inline void list_splice_init_rcu(struct list_head *list,
  * as long as the traversal is guarded by rcu_read_lock().
  */
 #define list_for_each_entry_rcu(pos, head, member) \
-        for (pos = list_entry(rcu_dereference((head)->next), typeof(*pos), member); \
+        for (pos = list_entry_rcu((head)->next, typeof(*pos), member); \
                 prefetch(pos->member.next), &pos->member != (head); \
-                pos = list_entry(rcu_dereference(pos->member.next), typeof(*pos), member))
+                pos = list_entry_rcu(pos->member.next, typeof(*pos), member))
 
 
 /**
diff --git a/include/linux/rcutree.h b/include/linux/rcutree.h
index 58b2aa5312b9..5a5153806c42 100644
--- a/include/linux/rcutree.h
+++ b/include/linux/rcutree.h
@@ -161,8 +161,15 @@ struct rcu_data {
         unsigned long offline_fqs;      /* Kicked due to being offline. */
         unsigned long resched_ipi;      /* Sent a resched IPI. */
 
-        /* 5) For future __rcu_pending statistics. */
+        /* 5) __rcu_pending() statistics. */
         long n_rcu_pending;             /* rcu_pending() calls since boot. */
+        long n_rp_qs_pending;
+        long n_rp_cb_ready;
+        long n_rp_cpu_needs_gp;
+        long n_rp_gp_completed;
+        long n_rp_gp_started;
+        long n_rp_need_fqs;
+        long n_rp_need_nothing;
 
         int cpu;
 };
diff --git a/include/linux/sched.h b/include/linux/sched.h
index dbb1043e8656..d4646ae300f0 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -77,6 +77,7 @@ struct sched_param {
 #include <linux/proportions.h>
 #include <linux/seccomp.h>
 #include <linux/rcupdate.h>
+#include <linux/rculist.h>
 #include <linux/rtmutex.h>
 
 #include <linux/time.h>
@@ -2030,7 +2031,8 @@ static inline unsigned long wait_task_inactive(struct task_struct *p,
 }
 #endif
 
-#define next_task(p)    list_entry(rcu_dereference((p)->tasks.next), struct task_struct, tasks)
+#define next_task(p) \
+        list_entry_rcu((p)->tasks.next, struct task_struct, tasks)
 
 #define for_each_process(p) \
         for (p = &init_task ; (p = next_task(p)) != &init_task ; )
@@ -2069,8 +2071,8 @@ int same_thread_group(struct task_struct *p1, struct task_struct *p2)
 
 static inline struct task_struct *next_thread(const struct task_struct *p)
 {
-        return list_entry(rcu_dereference(p->thread_group.next),
-                          struct task_struct, thread_group);
+        return list_entry_rcu(p->thread_group.next,
+                              struct task_struct, thread_group);
 }
 
 static inline int thread_group_empty(struct task_struct *p)