3 files changed, 61 insertions, 6 deletions

diff --git a/include/linux/rcuclassic.h b/include/linux/rcuclassic.h
index b3aa05baab8a..8c774905dcfe 100644
--- a/include/linux/rcuclassic.h
+++ b/include/linux/rcuclassic.h
@@ -151,7 +151,10 @@ extern struct lockdep_map rcu_lock_map;
 
 #define __synchronize_sched() synchronize_rcu()
 
+#define call_rcu_sched(head, func) call_rcu(head, func)
+
 extern void __rcu_init(void);
+#define rcu_init_sched()        do { } while (0)
 extern void rcu_check_callbacks(int cpu, int user);
 extern void rcu_restart_cpu(int cpu);
 
diff --git a/include/linux/rcupdate.h b/include/linux/rcupdate.h
index ec2fc5b32646..411969cb5243 100644
--- a/include/linux/rcupdate.h
+++ b/include/linux/rcupdate.h
@@ -40,6 +40,7 @@
 #include <linux/cpumask.h>
 #include <linux/seqlock.h>
 #include <linux/lockdep.h>
+#include <linux/completion.h>
 
 /**
  * struct rcu_head - callback structure for use with RCU
@@ -168,6 +169,27 @@ struct rcu_head {
                 (p) = (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);
+
+#define synchronize_rcu_xxx(name, func) \
+void name(void) \
+{ \
+        struct rcu_synchronize rcu; \
+        \
+        init_completion(&rcu.completion); \
+        /* Will wake me after RCU finished. */ \
+        func(&rcu.head, wakeme_after_rcu); \
+        /* Wait for it. */ \
+        wait_for_completion(&rcu.completion); \
+}
+
 /**
  * synchronize_sched - block until all CPUs have exited any non-preemptive
  * kernel code sequences.
diff --git a/include/linux/rcupreempt.h b/include/linux/rcupreempt.h
index 8a05c7e20bc4..f04b64eca636 100644
--- a/include/linux/rcupreempt.h
+++ b/include/linux/rcupreempt.h
@@ -40,10 +40,39 @@
 #include <linux/cpumask.h>
 #include <linux/seqlock.h>
 
-#define rcu_qsctr_inc(cpu)
+struct rcu_dyntick_sched {
+        int dynticks;
+        int dynticks_snap;
+        int sched_qs;
+        int sched_qs_snap;
+        int sched_dynticks_snap;
+};
+
+DECLARE_PER_CPU(struct rcu_dyntick_sched, rcu_dyntick_sched);
+
+static inline void rcu_qsctr_inc(int cpu)
+{
+        struct rcu_dyntick_sched *rdssp = &per_cpu(rcu_dyntick_sched, cpu);
+
+        rdssp->sched_qs++;
+}
 #define rcu_bh_qsctr_inc(cpu)
 #define call_rcu_bh(head, rcu) call_rcu(head, rcu)
 
+/**
+ * call_rcu_sched - Queue RCU callback for invocation after sched grace period.
+ * @head: structure to be used for queueing the RCU updates.
+ * @func: actual update function to be invoked after the grace period
+ *
+ * The update function will be invoked some time after a full
+ * synchronize_sched()-style grace period elapses, in other words after
+ * all currently executing preempt-disabled sections of code (including
+ * hardirq handlers, NMI handlers, and local_irq_save() blocks) have
+ * completed.
+ */
+extern void call_rcu_sched(struct rcu_head *head,
+                           void (*func)(struct rcu_head *head));
+
 extern void __rcu_read_lock(void)       __acquires(RCU);
 extern void __rcu_read_unlock(void)     __releases(RCU);
 extern int rcu_pending(int cpu);
@@ -55,6 +84,7 @@ extern int rcu_needs_cpu(int cpu);
 extern void __synchronize_sched(void);
 
 extern void __rcu_init(void);
+extern void rcu_init_sched(void);
 extern void rcu_check_callbacks(int cpu, int user);
 extern void rcu_restart_cpu(int cpu);
 extern long rcu_batches_completed(void);
@@ -81,20 +111,20 @@ extern struct rcupreempt_trace *rcupreempt_trace_cpu(int cpu);
 struct softirq_action;
 
 #ifdef CONFIG_NO_HZ
-DECLARE_PER_CPU(long, dynticks_progress_counter);
+DECLARE_PER_CPU(struct rcu_dyntick_sched, rcu_dyntick_sched);
 
 static inline void rcu_enter_nohz(void)
 {
         smp_mb(); /* CPUs seeing ++ must see prior RCU read-side crit sects */
-        __get_cpu_var(dynticks_progress_counter)++;
-        WARN_ON(__get_cpu_var(dynticks_progress_counter) & 0x1);
+        __get_cpu_var(rcu_dyntick_sched).dynticks++;
+        WARN_ON(__get_cpu_var(rcu_dyntick_sched).dynticks & 0x1);
 }
 
 static inline void rcu_exit_nohz(void)
 {
-        __get_cpu_var(dynticks_progress_counter)++;
         smp_mb(); /* CPUs seeing ++ must see later RCU read-side crit sects */
-        WARN_ON(!(__get_cpu_var(dynticks_progress_counter) & 0x1));
+        __get_cpu_var(rcu_dyntick_sched).dynticks++;
+        WARN_ON(!(__get_cpu_var(rcu_dyntick_sched).dynticks & 0x1));
 }
 
 #else /* CONFIG_NO_HZ */