1 files changed, 7 insertions, 133 deletions

diff --git a/kernel/rcupdate.c b/kernel/rcupdate.c
index 37ac454..4001833 100644
--- a/kernel/rcupdate.c
+++ b/kernel/rcupdate.c
@@ -46,22 +46,15 @@
 #include <linux/module.h>
 #include <linux/kernel_stat.h>
 
-enum rcu_barrier {
-	RCU_BARRIER_STD,
-	RCU_BARRIER_BH,
-	RCU_BARRIER_SCHED,
-};
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+static struct lock_class_key rcu_lock_key;
+struct lockdep_map rcu_lock_map =
+	STATIC_LOCKDEP_MAP_INIT("rcu_read_lock", &rcu_lock_key);
+EXPORT_SYMBOL_GPL(rcu_lock_map);
+#endif
 
-static DEFINE_PER_CPU(struct rcu_head, rcu_barrier_head) = {NULL};
-static atomic_t rcu_barrier_cpu_count;
-static DEFINE_MUTEX(rcu_barrier_mutex);
-static struct completion rcu_barrier_completion;
 int rcu_scheduler_active __read_mostly;
 
-static atomic_t rcu_migrate_type_count = ATOMIC_INIT(0);
-static struct rcu_head rcu_migrate_head[3];
-static DECLARE_WAIT_QUEUE_HEAD(rcu_migrate_wq);
-
 /*
  * Awaken the corresponding synchronize_rcu() instance now that a
  * grace period has elapsed.
@@ -164,129 +157,10 @@ void synchronize_rcu_bh(void)
 }
 EXPORT_SYMBOL_GPL(synchronize_rcu_bh);
 
-static void rcu_barrier_callback(struct rcu_head *notused)
-{
-	if (atomic_dec_and_test(&rcu_barrier_cpu_count))
-		complete(&rcu_barrier_completion);
-}
-
-/*
- * Called with preemption disabled, and from cross-cpu IRQ context.
- */
-static void rcu_barrier_func(void *type)
-{
-	int cpu = smp_processor_id();
-	struct rcu_head *head = &per_cpu(rcu_barrier_head, cpu);
-
-	atomic_inc(&rcu_barrier_cpu_count);
-	switch ((enum rcu_barrier)type) {
-	case RCU_BARRIER_STD:
-		call_rcu(head, rcu_barrier_callback);
-		break;
-	case RCU_BARRIER_BH:
-		call_rcu_bh(head, rcu_barrier_callback);
-		break;
-	case RCU_BARRIER_SCHED:
-		call_rcu_sched(head, rcu_barrier_callback);
-		break;
-	}
-}
-
-static inline void wait_migrated_callbacks(void)
-{
-	wait_event(rcu_migrate_wq, !atomic_read(&rcu_migrate_type_count));
-	smp_mb(); /* In case we didn't sleep. */
-}
-
-/*
- * Orchestrate the specified type of RCU barrier, waiting for all
- * RCU callbacks of the specified type to complete.
- */
-static void _rcu_barrier(enum rcu_barrier type)
-{
-	BUG_ON(in_interrupt());
-	/* Take cpucontrol mutex to protect against CPU hotplug */
-	mutex_lock(&rcu_barrier_mutex);
-	init_completion(&rcu_barrier_completion);
-	/*
-	 * Initialize rcu_barrier_cpu_count to 1, then invoke
-	 * rcu_barrier_func() on each CPU, so that each CPU also has
-	 * incremented rcu_barrier_cpu_count.  Only then is it safe to
-	 * decrement rcu_barrier_cpu_count -- otherwise the first CPU
-	 * might complete its grace period before all of the other CPUs
-	 * did their increment, causing this function to return too
-	 * early.
-	 */
-	atomic_set(&rcu_barrier_cpu_count, 1);
-	on_each_cpu(rcu_barrier_func, (void *)type, 1);
-	if (atomic_dec_and_test(&rcu_barrier_cpu_count))
-		complete(&rcu_barrier_completion);
-	wait_for_completion(&rcu_barrier_completion);
-	mutex_unlock(&rcu_barrier_mutex);
-	wait_migrated_callbacks();
-}
-
-/**
- * rcu_barrier - Wait until all in-flight call_rcu() callbacks complete.
- */
-void rcu_barrier(void)
-{
-	_rcu_barrier(RCU_BARRIER_STD);
-}
-EXPORT_SYMBOL_GPL(rcu_barrier);
-
-/**
- * rcu_barrier_bh - Wait until all in-flight call_rcu_bh() callbacks complete.
- */
-void rcu_barrier_bh(void)
-{
-	_rcu_barrier(RCU_BARRIER_BH);
-}
-EXPORT_SYMBOL_GPL(rcu_barrier_bh);
-
-/**
- * rcu_barrier_sched - Wait for in-flight call_rcu_sched() callbacks.
- */
-void rcu_barrier_sched(void)
-{
-	_rcu_barrier(RCU_BARRIER_SCHED);
-}
-EXPORT_SYMBOL_GPL(rcu_barrier_sched);
-
-static void rcu_migrate_callback(struct rcu_head *notused)
-{
-	if (atomic_dec_and_test(&rcu_migrate_type_count))
-		wake_up(&rcu_migrate_wq);
-}
-
-extern int rcu_cpu_notify(struct notifier_block *self,
-			  unsigned long action, void *hcpu);
-
 static int __cpuinit rcu_barrier_cpu_hotplug(struct notifier_block *self,
 		unsigned long action, void *hcpu)
 {
-	rcu_cpu_notify(self, action, hcpu);
-	if (action == CPU_DYING) {
-		/*
-		 * preempt_disable() in on_each_cpu() prevents stop_machine(),
-		 * so when "on_each_cpu(rcu_barrier_func, (void *)type, 1);"
-		 * returns, all online cpus have queued rcu_barrier_func(),
-		 * and the dead cpu(if it exist) queues rcu_migrate_callback()s.
-		 *
-		 * These callbacks ensure _rcu_barrier() waits for all
-		 * RCU callbacks of the specified type to complete.
-		 */
-		atomic_set(&rcu_migrate_type_count, 3);
-		call_rcu_bh(rcu_migrate_head, rcu_migrate_callback);
-		call_rcu_sched(rcu_migrate_head + 1, rcu_migrate_callback);
-		call_rcu(rcu_migrate_head + 2, rcu_migrate_callback);
-	} else if (action == CPU_DOWN_PREPARE) {
-		/* Don't need to wait until next removal operation. */
-		/* rcu_migrate_head is protected by cpu_add_remove_lock */
-		wait_migrated_callbacks();
-	}
-
-	return NOTIFY_OK;
+	return rcu_cpu_notify(self, action, hcpu);
 }
 
 void __init rcu_init(void)