ring-buffer: add tracing_is_on to test if ring buffer is enabled

This patch adds the tracing_is_on() interface to tell if the ring
buffer is turned on or not.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>

1 files changed, 2 insertions, 0 deletions

diff --git a/include/linux/ring_buffer.h b/include/linux/ring_buffer.h
index 8e6646a54acf..f5e793d69bd3 100644
--- a/include/linux/ring_buffer.h
+++ b/include/linux/ring_buffer.h
@@ -128,10 +128,12 @@ void ring_buffer_normalize_time_stamp(int cpu, u64 *ts);
 void tracing_on(void);
 void tracing_off(void);
 void tracing_off_permanent(void);
+int tracing_is_on(void);
 #else
 static inline void tracing_on(void) { }
 static inline void tracing_off(void) { }
 static inline void tracing_off_permanent(void) { }
+static inline int tracing_is_on(void) { return 0; }
 #endif
 
 void *ring_buffer_alloc_read_page(struct ring_buffer *buffer);