Merge branch 'next' of https://git.kernel.org/pub/scm/linux/kernel/git/rcu/linux

1 files changed, 13 insertions, 0 deletions

diff --git a/include/linux/srcutiny.h b/include/linux/srcutiny.h
index 905b629e8fa3..fbcf13bc12d1 100644
--- a/include/linux/srcutiny.h
+++ b/include/linux/srcutiny.h
@@ -154,4 +154,17 @@ static inline void srcu_torture_stats_print(struct srcu_struct *ssp,
 		 data_race(READ_ONCE(ssp->srcu_idx_max)));
 }
 
+/**
+ * srcu_readers_active - returns true if there are readers. and false otherwise.
+ * @ssp: which srcu_struct to count active readers (holding srcu_read_lock).
+ *
+ * Note that this is not an atomic primitive, and can therefore suffer
+ * severe errors when invoked on an active srcu_struct. That said, it
+ * can be useful as an error check at cleanup time.
+ */
+static inline bool srcu_readers_active(struct srcu_struct *ssp)
+{
+	return READ_ONCE(ssp->srcu_lock_nesting[0]) || READ_ONCE(ssp->srcu_lock_nesting[1]);
+}
+
 #endif