rcu: Abstract common code for RCU grace-period-wait primitives
Pull the code that waits for an RCU grace period into a single function,
which is then called by synchronize_rcu() and friends in the case of
TREE_RCU and TREE_PREEMPT_RCU, and from rcu_barrier() and friends in
the case of TINY_RCU and TINY_PREEMPT_RCU.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
diff --git a/kernel/rcupdate.c b/kernel/rcupdate.c
index ddddb32..09b3b1b 100644
--- a/kernel/rcupdate.c
+++ b/kernel/rcupdate.c
@@ -94,11 +94,16 @@
#endif /* #ifdef CONFIG_DEBUG_LOCK_ALLOC */
+struct rcu_synchronize {
+ struct rcu_head head;
+ struct completion completion;
+};
+
/*
* Awaken the corresponding synchronize_rcu() instance now that a
* grace period has elapsed.
*/
-void wakeme_after_rcu(struct rcu_head *head)
+static void wakeme_after_rcu(struct rcu_head *head)
{
struct rcu_synchronize *rcu;
@@ -106,6 +111,20 @@
complete(&rcu->completion);
}
+void wait_rcu_gp(call_rcu_func_t crf)
+{
+ struct rcu_synchronize rcu;
+
+ init_rcu_head_on_stack(&rcu.head);
+ init_completion(&rcu.completion);
+ /* Will wake me after RCU finished. */
+ crf(&rcu.head, wakeme_after_rcu);
+ /* Wait for it. */
+ wait_for_completion(&rcu.completion);
+ destroy_rcu_head_on_stack(&rcu.head);
+}
+EXPORT_SYMBOL_GPL(wait_rcu_gp);
+
#ifdef CONFIG_PROVE_RCU
/*
* wrapper function to avoid #include problems.