From a50656778084c833278ecd55ee1d9604ffb3c643 Mon Sep 17 00:00:00 2001
From: Heiko Carstens <heiko.carstens@de.ibm.com>
Date: Mon, 15 May 2006 09:43:58 -0700
Subject: [PATCH] --- yaml --- r: 26701 b: refs/heads/master c:
 986733e01d258c26107f1da9d8d47c718349ad2f h: refs/heads/master i:   26699:
 1296c40752aa3e871a42f80e08467b1ae9da6bf2 v: v3

---
 [refs]                         |  2 +-
 trunk/include/linux/rcupdate.h |  1 +
 trunk/kernel/rcupdate.c        | 19 +++++++++++++++++++
 3 files changed, 21 insertions(+), 1 deletion(-)

diff --git a/[refs] b/[refs]
index 70e8aea3173b..cbf7feda4479 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 3b7c8108273bed41a2fc04533cc9f2026ff38c8e
+refs/heads/master: 986733e01d258c26107f1da9d8d47c718349ad2f
diff --git a/trunk/include/linux/rcupdate.h b/trunk/include/linux/rcupdate.h
index 5673008b61e1..970284f571a6 100644
--- a/trunk/include/linux/rcupdate.h
+++ b/trunk/include/linux/rcupdate.h
@@ -132,6 +132,7 @@ static inline void rcu_bh_qsctr_inc(int cpu)
 }
 
 extern int rcu_pending(int cpu);
+extern int rcu_needs_cpu(int cpu);
 
 /**
  * rcu_read_lock - mark the beginning of an RCU read-side critical section.
diff --git a/trunk/kernel/rcupdate.c b/trunk/kernel/rcupdate.c
index 6d32ff26f948..2058f88c7bbb 100644
--- a/trunk/kernel/rcupdate.c
+++ b/trunk/kernel/rcupdate.c
@@ -479,12 +479,31 @@ static int __rcu_pending(struct rcu_ctrlblk *rcp, struct rcu_data *rdp)
 	return 0;
 }
 
+/*
+ * Check to see if there is any immediate RCU-related work to be done
+ * by the current CPU, returning 1 if so.  This function is part of the
+ * RCU implementation; it is -not- an exported member of the RCU API.
+ */
 int rcu_pending(int cpu)
 {
 	return __rcu_pending(&rcu_ctrlblk, &per_cpu(rcu_data, cpu)) ||
 		__rcu_pending(&rcu_bh_ctrlblk, &per_cpu(rcu_bh_data, cpu));
 }
 
+/*
+ * Check to see if any future RCU-related work will need to be done
+ * by the current CPU, even if none need be done immediately, returning
+ * 1 if so.  This function is part of the RCU implementation; it is -not-
+ * an exported member of the RCU API.
+ */
+int rcu_needs_cpu(int cpu)
+{
+	struct rcu_data *rdp = &per_cpu(rcu_data, cpu);
+	struct rcu_data *rdp_bh = &per_cpu(rcu_bh_data, cpu);
+
+	return (!!rdp->curlist || !!rdp_bh->curlist || rcu_pending(cpu));
+}
+
 void rcu_check_callbacks(int cpu, int user)
 {
 	if (user ||