1 files changed, 25 insertions, 25 deletions

diff --git a/kernel/rcutree_plugin.h b/kernel/rcutree_plugin.h
index 1cee04f627eb..8ff1ba7b3c43 100644
--- a/kernel/rcutree_plugin.h
+++ b/kernel/rcutree_plugin.h
@@ -150,6 +150,16 @@ void __rcu_read_lock(void)
 }
 EXPORT_SYMBOL_GPL(__rcu_read_lock);
 
+/*
+ * Check for preempted RCU readers blocking the current grace period
+ * for the specified rcu_node structure.  If the caller needs a reliable
+ * answer, it must hold the rcu_node's ->lock.
+ */
+static int rcu_preempted_readers(struct rcu_node *rnp)
+{
+        return !list_empty(&rnp->blocked_tasks[rnp->gpnum & 0x1]);
+}
+
 static void rcu_read_unlock_special(struct task_struct *t)
 {
         int empty;
@@ -196,7 +206,7 @@ static void rcu_read_unlock_special(struct task_struct *t)
                                 break;
                         spin_unlock(&rnp->lock);  /* irqs remain disabled. */
                 }
-                empty = list_empty(&rnp->blocked_tasks[rnp->gpnum & 0x1]);
+                empty = !rcu_preempted_readers(rnp);
                 list_del_init(&t->rcu_node_entry);
                 t->rcu_blocked_node = NULL;
 
@@ -207,7 +217,7 @@ static void rcu_read_unlock_special(struct task_struct *t)
                  * drop rnp->lock and restore irq.
                  */
                 if (!empty && rnp->qsmask == 0 &&
-                    list_empty(&rnp->blocked_tasks[rnp->gpnum & 0x1])) {
+                    !rcu_preempted_readers(rnp)) {
                         struct rcu_node *rnp_p;
 
                         if (rnp->parent == NULL) {
@@ -257,12 +267,12 @@ static void rcu_print_task_stall(struct rcu_node *rnp)
 {
         unsigned long flags;
         struct list_head *lp;
-        int phase = rnp->gpnum & 0x1;
+        int phase;
         struct task_struct *t;
 
-        if (!list_empty(&rnp->blocked_tasks[phase])) {
+        if (rcu_preempted_readers(rnp)) {
                 spin_lock_irqsave(&rnp->lock, flags);
-                phase = rnp->gpnum & 0x1; /* re-read under lock. */
+                phase = rnp->gpnum & 0x1;
                 lp = &rnp->blocked_tasks[phase];
                 list_for_each_entry(t, lp, rcu_node_entry)
                         printk(" P%d", t->pid);
@@ -281,20 +291,10 @@ static void rcu_print_task_stall(struct rcu_node *rnp)
  */
 static void rcu_preempt_check_blocked_tasks(struct rcu_node *rnp)
 {
-        WARN_ON_ONCE(!list_empty(&rnp->blocked_tasks[rnp->gpnum & 0x1]));
+        WARN_ON_ONCE(rcu_preempted_readers(rnp));
         WARN_ON_ONCE(rnp->qsmask);
 }
 
-/*
- * Check for preempted RCU readers for the specified rcu_node structure.
- * If the caller needs a reliable answer, it must hold the rcu_node's
- * >lock.
- */
-static int rcu_preempted_readers(struct rcu_node *rnp)
-{
-        return !list_empty(&rnp->blocked_tasks[rnp->gpnum & 0x1]);
-}
-
 #ifdef CONFIG_HOTPLUG_CPU
 
 /*
@@ -461,6 +461,15 @@ static void rcu_preempt_note_context_switch(int cpu)
 {
 }
 
+/*
+ * Because preemptable RCU does not exist, there are never any preempted
+ * RCU readers.
+ */
+static int rcu_preempted_readers(struct rcu_node *rnp)
+{
+        return 0;
+}
+
 #ifdef CONFIG_RCU_CPU_STALL_DETECTOR
 
 /*
@@ -483,15 +492,6 @@ static void rcu_preempt_check_blocked_tasks(struct rcu_node *rnp)
         WARN_ON_ONCE(rnp->qsmask);
 }
 
-/*
- * Because preemptable RCU does not exist, there are never any preempted
- * RCU readers.
- */
-static int rcu_preempted_readers(struct rcu_node *rnp)
-{
-        return 0;
-}
-
 #ifdef CONFIG_HOTPLUG_CPU
 
 /*