rcu: create rcu_my_thread_group_empty() wrapper
Some RCU-lockdep splat repairs need to know whether they are running
in a single-threaded process. Unfortunately, the thread_group_empty()
primitive is defined in sched.h, and can induce #include hell. This
commit therefore introduces a rcu_my_thread_group_empty() wrapper that
is defined in rcupdate.c, thus avoiding the need to include sched.h
everywhere.
Signed-off-by: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
diff --git a/include/linux/rcupdate.h b/include/linux/rcupdate.h
index 07db2fe..db266bb 100644
--- a/include/linux/rcupdate.h
+++ b/include/linux/rcupdate.h
@@ -190,6 +190,8 @@
#ifdef CONFIG_PROVE_RCU
+extern int rcu_my_thread_group_empty(void);
+
/**
* rcu_dereference_check - rcu_dereference with debug checking
* @p: The pointer to read, prior to dereferencing
diff --git a/kernel/rcupdate.c b/kernel/rcupdate.c
index 03a7ea1..49d808e 100644
--- a/kernel/rcupdate.c
+++ b/kernel/rcupdate.c
@@ -122,3 +122,14 @@
rcu = container_of(head, struct rcu_synchronize, head);
complete(&rcu->completion);
}
+
+#ifdef CONFIG_PROVE_RCU
+/*
+ * wrapper function to avoid #include problems.
+ */
+int rcu_my_thread_group_empty(void)
+{
+ return thread_group_empty(current);
+}
+EXPORT_SYMBOL_GPL(rcu_my_thread_group_empty);
+#endif /* #ifdef CONFIG_PROVE_RCU */