From 2a2df321158817811c5dc206dce808e0aa9f6d89 Mon Sep 17 00:00:00 2001 From: Tom Zanussi Date: Thu, 24 Oct 2013 08:59:25 -0500 Subject: tracing: Add 'traceon' and 'traceoff' event trigger commands Add 'traceon' and 'traceoff' event_command commands. traceon and traceoff event triggers are added by the user via these commands in a similar way and using practically the same syntax as the analagous 'traceon' and 'traceoff' ftrace function commands, but instead of writing to the set_ftrace_filter file, the traceon and traceoff triggers are written to the per-event 'trigger' files: echo 'traceon' > .../tracing/events/somesys/someevent/trigger echo 'traceoff' > .../tracing/events/somesys/someevent/trigger The above command will turn tracing on or off whenever someevent is hit. This also adds a 'count' version that limits the number of times the command will be invoked: echo 'traceon:N' > .../tracing/events/somesys/someevent/trigger echo 'traceoff:N' > .../tracing/events/somesys/someevent/trigger Where N is the number of times the command will be invoked. The above commands will will turn tracing on or off whenever someevent is hit, but only N times. Some common register/unregister_trigger() implementations of the event_command reg()/unreg() callbacks are also provided, which add and remove trigger instances to the per-event list of triggers, and arm/disarm them as appropriate. event_trigger_callback() is a general-purpose event_command func() implementation that orchestrates command parsing and registration for most normal commands. Most event commands will use these, but some will override and possibly reuse them. The event_trigger_init(), event_trigger_free(), and event_trigger_print() functions are meant to be common implementations of the event_trigger_ops init(), free(), and print() ops, respectively. Most trigger_ops implementations will use these, but some will override and possibly reuse them. Link: http://lkml.kernel.org/r/00a52816703b98d2072947478dd6e2d70cde5197.1382622043.git.tom.zanussi@linux.intel.com Signed-off-by: Tom Zanussi Signed-off-by: Steven Rostedt --- include/linux/ftrace_event.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/linux/ftrace_event.h') diff --git a/include/linux/ftrace_event.h b/include/linux/ftrace_event.h index 211e7ad2baf5..711c4dcfe8b7 100644 --- a/include/linux/ftrace_event.h +++ b/include/linux/ftrace_event.h @@ -345,6 +345,7 @@ struct ftrace_event_file { enum event_trigger_type { ETT_NONE = (0), + ETT_TRACE_ONOFF = (1 << 0), }; extern void destroy_preds(struct ftrace_event_file *file); -- cgit v1.2.1