tracing: New macro to set up initial event flags value

This introduces the new TRACE_EVENT_FLAGS() macro in order
to set up initial event flags value.

This macro must simply follow the definition of a trace event
and take the event name and the flag value as parameters:

TRACE_EVENT(my_event, .....
....
);

TRACE_EVENT_FLAGS(my_event, 1)

This will set up 1 as the initial my_event->flags value.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: Jason Baron <jbaron@redhat.com>

2 files changed, 16 insertions, 0 deletions

diff --git a/include/linux/tracepoint.h b/include/linux/tracepoint.h
index a4a90b6726ce..5a6074fcd81d 100644
--- a/include/linux/tracepoint.h
+++ b/include/linux/tracepoint.h
@@ -234,6 +234,8 @@ do_trace:								\
                                 PARAMS(void *__data, proto),            \
                                 PARAMS(__data, args))
 
+#define TRACE_EVENT_FLAGS(event, flag)
+
 #endif /* DECLARE_TRACE */
 
 #ifndef TRACE_EVENT
@@ -354,4 +356,6 @@ do_trace:								\
                 assign, print, reg, unreg)                      \
         DECLARE_TRACE(name, PARAMS(proto), PARAMS(args))
 
+#define TRACE_EVENT_FLAGS(event, flag)
+
 #endif /* ifdef TRACE_EVENT (see note above) */
diff --git a/include/trace/ftrace.h b/include/trace/ftrace.h
index a9377c0083ad..6f540123d43e 100644
--- a/include/trace/ftrace.h
+++ b/include/trace/ftrace.h
@@ -82,6 +82,15 @@
         TRACE_EVENT(name, PARAMS(proto), PARAMS(args),                  \
                 PARAMS(tstruct), PARAMS(assign), PARAMS(print))         \
 
+#undef TRACE_EVENT_FLAGS
+#define TRACE_EVENT_FLAGS(name, value)                                  \
+        static int __init trace_init_flags_##name(void)                 \
+        {                                                               \
+                event_##name.flags = value;                             \
+                return 0;                                               \
+        }                                                               \
+        early_initcall(trace_init_flags_##name);
+
 #include TRACE_INCLUDE(TRACE_INCLUDE_FILE)
 
 
@@ -129,6 +138,9 @@
 #define DEFINE_EVENT_PRINT(template, name, proto, args, print)  \
         DEFINE_EVENT(template, name, PARAMS(proto), PARAMS(args))
 
+#undef TRACE_EVENT_FLAGS
+#define TRACE_EVENT_FLAGS(event, flag)
+
 #include TRACE_INCLUDE(TRACE_INCLUDE_FILE)
 
 /*