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/kernel/trace/Kconfig b/kernel/trace/Kconfig
index 07877f4..999c6a2 100644
--- a/kernel/trace/Kconfig
+++ b/kernel/trace/Kconfig
@@ -159,6 +159,15 @@
This tracer gets called from the context switch and records
all switching of tasks.
+config EVENT_TRACER
+ bool "Trace various events in the kernel"
+ depends on DEBUG_KERNEL
+ select TRACING
+ help
+ This tracer hooks to various trace points in the kernel
+ allowing the user to pick and choose which trace point they
+ want to trace.
+
config BOOT_TRACER
bool "Trace boot initcalls"
depends on DEBUG_KERNEL