tree 9470e9b4e886466511d47a70281e77e5a8c674ff
parent c32e827b25054cb17b79cf97fb5e63ae4ce2223c
author Steven Rostedt <srostedt@redhat.com> 1235806885 -0500
committer Steven Rostedt <srostedt@redhat.com> 1235811843 -0500

tracing: add raw fast tracing interface for trace events

This patch adds the interface to enable the C style trace points.
In the directory /debugfs/tracing/events/subsystem/event
We now have three files:

 enable : values 0 or 1 to enable or disable the trace event.

 available_types: values 'raw' and 'printf' which indicate the tracing
       types available for the trace point. If a developer does not
       use the TRACE_EVENT_FORMAT macro and just uses the TRACE_FORMAT
       macro, then only 'printf' will be available. This file is
       read only.

 type: values 'raw' or 'printf'. This indicates which type of tracing
       is active for that trace point. 'printf' is the default and
       if 'raw' is not available, this file is read only.

 # echo raw > /debug/tracing/events/sched/sched_wakeup/type
 # echo 1 > /debug/tracing/events/sched/sched_wakeup/enable

 Will enable the C style tracing for the sched_wakeup trace point.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>