tracing: add event trace infrastructure
This patch creates the event tracing infrastructure of ftrace.
It will create the files:
/debug/tracing/available_events
/debug/tracing/set_event
The available_events will list the trace points that have been
registered with the event tracer.
set_events will allow the user to enable or disable an event hook.
example:
# echo sched_wakeup > /debug/tracing/set_event
Will enable the sched_wakeup event (if it is registered).
# echo "!sched_wakeup" >> /debug/tracing/set_event
Will disable the sched_wakeup event (and only that event).
# echo > /debug/tracing/set_event
Will disable all events (notice the '>')
# cat /debug/tracing/available_events > /debug/tracing/set_event
Will enable all registered event hooks.
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h
index c61fab1..0add6b2 100644
--- a/include/asm-generic/vmlinux.lds.h
+++ b/include/asm-generic/vmlinux.lds.h
@@ -61,6 +61,14 @@
#define BRANCH_PROFILE()
#endif
+#ifdef CONFIG_EVENT_TRACER
+#define FTRACE_EVENTS() VMLINUX_SYMBOL(__start_ftrace_events) = .; \
+ *(_ftrace_events) \
+ VMLINUX_SYMBOL(__stop_ftrace_events) = .;
+#else
+#define FTRACE_EVENTS()
+#endif
+
/* .data section */
#define DATA_DATA \
*(.data) \
@@ -81,7 +89,8 @@
*(__tracepoints) \
VMLINUX_SYMBOL(__stop___tracepoints) = .; \
LIKELY_PROFILE() \
- BRANCH_PROFILE()
+ BRANCH_PROFILE() \
+ FTRACE_EVENTS()
#define RO_DATA(align) \
. = ALIGN((align)); \