tracing: Fix sample output of dynamic arrays

[cascardo/linux.git] / samples / trace_events / trace-events-sample.h

diff --git a/samples/trace_events/trace-events-sample.h b/samples/trace_events/trace-events-sample.h
index 8965d1b..125d640 100644 (file)
--- a/samples/trace_events/trace-events-sample.h
+++ b/samples/trace_events/trace-events-sample.h
@@ -168,7 +168,10 @@
  *
  *      For __dynamic_array(int, foo, bar) use __get_dynamic_array(foo)
  *            Use __get_dynamic_array_len(foo) to get the length of the array
- *            saved.
+ *            saved. Note, __get_dynamic_array_len() returns the total allocated
+ *            length of the dynamic array; __print_array() expects the second
+ *            parameter to be the number of elements. To get that, the array length
+ *            needs to be divided by the element size.
  *
  *      For __string(foo, bar) use __get_str(foo)
  *
@@ -288,7 +291,7 @@ TRACE_EVENT(foo_bar,
  *    This prints out the array that is defined by __array in a nice format.
  */
                  __print_array(__get_dynamic_array(list),
-                               __get_dynamic_array_len(list),
+                               __get_dynamic_array_len(list) / sizeof(int),
                                sizeof(int)),
                  __get_str(str), __get_bitmask(cpus))
 );