Commit 336c92b2 authored by Daniel Bristot de Oliveira's avatar Daniel Bristot de Oliveira Committed by Steven Rostedt (Google)
Browse files

rtla/trace: Add trace event trigger helpers 

Add a set of helper functions to allow rtla tools to trigger event
actions in the trace instance.

Link: https://lkml.kernel.org/r/e0d31abe879a78a5600b64f904d0dfa8f76e4fbb.1646247211.git.bristot@kernel.org



Cc: Daniel Bristot de Oliveira <bristot@kernel.org>
Cc: Clark Williams <williams@redhat.com>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: default avatarDaniel Bristot de Oliveira <bristot@kernel.org>
Signed-off-by: default avatarSteven Rostedt (Google) <rostedt@goodmis.org>
parent 51d64c3a

tools/tracing/rtla/src/trace.c

+87 −1
Original line number Diff line number Diff line
@@ -204,6 +204,8 @@ static void trace_events_free(struct trace_events *events) 


		tevent = tevent->next;



		if (free_event->trigger)

			free(free_event->trigger);

		free(free_event->system);

		free(free_event);

	}
@@ -235,6 +237,48 @@ struct trace_events *trace_event_alloc(const char *event_string) 
	return tevent;

}



/*

 * trace_event_add_trigger - record an event trigger action

 */

int trace_event_add_trigger(struct trace_events *event, char *trigger)

{

	if (event->trigger)

		free(event->trigger);



	event->trigger = strdup(trigger);

	if (!event->trigger)

		return 1;



	return 0;

}



/*

 * trace_event_disable_trigger - disable an event trigger

 */

static void trace_event_disable_trigger(struct trace_instance *instance,

					struct trace_events *tevent)

{

	char trigger[1024];

	int retval;



	if (!tevent->trigger)

		return;



	if (!tevent->trigger_enabled)

		return;



	debug_msg("Disabling %s:%s trigger %s\n", tevent->system,

		  tevent->event ? : "*", tevent->trigger);



	snprintf(trigger, 1024, "!%s\n", tevent->trigger);



	retval = tracefs_event_file_write(instance->inst, tevent->system,

					  tevent->event, "trigger", trigger);

	if (retval < 0)

		err_msg("Error disabling %s:%s trigger %s\n", tevent->system,

			tevent->event ? : "*", tevent->trigger);

}



/*

 * trace_events_disable - disable all trace events

 */
@@ -248,14 +292,52 @@ void trace_events_disable(struct trace_instance *instance, 


	while (tevent) {

		debug_msg("Disabling event %s:%s\n", tevent->system, tevent->event ? : "*");

		if (tevent->enabled)

		if (tevent->enabled) {

			trace_event_disable_trigger(instance, tevent);

			tracefs_event_disable(instance->inst, tevent->system, tevent->event);

		}



		tevent->enabled = 0;

		tevent = tevent->next;

	}

}



/*

 * trace_event_enable_trigger - enable an event trigger associated with an event

 */

static int trace_event_enable_trigger(struct trace_instance *instance,

				      struct trace_events *tevent)

{

	char trigger[1024];

	int retval;



	if (!tevent->trigger)

		return 0;



	if (!tevent->event) {

		err_msg("Trigger %s applies only for single events, not for all %s:* events\n",

			tevent->trigger, tevent->system);

		return 1;

	}



	snprintf(trigger, 1024, "%s\n", tevent->trigger);



	debug_msg("Enabling %s:%s trigger %s\n", tevent->system,

		  tevent->event ? : "*", tevent->trigger);



	retval = tracefs_event_file_write(instance->inst, tevent->system,

					  tevent->event, "trigger", trigger);

	if (retval < 0) {

		err_msg("Error enabling %s:%s trigger %s\n", tevent->system,

			tevent->event ? : "*", tevent->trigger);

		return 1;

	}



	tevent->trigger_enabled = 1;



	return 0;

}



/*

 * trace_events_enable - enable all events

 */
@@ -275,6 +357,10 @@ int trace_events_enable(struct trace_instance *instance, 
		}





		retval = trace_event_enable_trigger(instance, tevent);

		if (retval)

			return 1;



		tevent->enabled = 1;

		tevent = tevent->next;

	}

tools/tracing/rtla/src/trace.h

+4 −0
Original line number Diff line number Diff line
@@ -6,7 +6,9 @@ struct trace_events { 
	struct trace_events *next;

	char *system;

	char *event;

	char *trigger;

	char enabled;

	char trigger_enabled;

};



struct trace_instance {
@@ -40,3 +42,5 @@ void trace_events_destroy(struct trace_instance *instance, 
			  struct trace_events *events);

int trace_events_enable(struct trace_instance *instance,

			  struct trace_events *events);



int trace_event_add_trigger(struct trace_events *event, char *trigger);