tracing: Add comment to describe special break case in probe_remove_event_call()

The "break" used in the do_for_each_event_file() is used as an optimization
as the loop is really a double loop. The loop searches all event files
for each trace_array. There's only one matching event file per trace_array
and after we find the event file for the trace_array, the break is used
to jump to the next trace_array and start the search there.

As this is not a standard way of using "break" in C code, it requires
a comment right before the break to let people know what is going on.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c
index ec04836..29a7ebc 100644 (file)
--- a/kernel/trace/trace_events.c
+++ b/kernel/trace/trace_events.c
@@ -1732,6 +1732,12 @@ static int probe_remove_event_call(struct ftrace_event_call *call)
                 */
                if (file->flags & FTRACE_EVENT_FL_ENABLED)
                        return -EBUSY;
+               /*
+                * The do_for_each_event_file_safe() is
+                * a double loop. After finding the call for this
+                * trace_array, we use break to jump to the next
+                * trace_array.
+                */
                break;
        } while_for_each_event_file();