Commit b5aa0be2 authored by Daniel Bristot de Oliveira's avatar Daniel Bristot de Oliveira Committed by Steven Rostedt (Google)
Browse files

rtla/trace: Add trace events helpers 

Add a set of helper functions to allow the rtla tools to enable
additional tracepoints in the trace instance.

Link: https://lkml.kernel.org/r/932398b36c1bbaa22c7810d7a40ca9b8c5595b94.1646247211.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 173a3b01

tools/tracing/rtla/src/trace.c

+104 −0
Original line number Diff line number Diff line
@@ -190,3 +190,107 @@ int trace_instance_start(struct trace_instance *trace) 
{

	return tracefs_trace_on(trace->inst);

}



/*

 * trace_events_free - free a list of trace events

 */

static void trace_events_free(struct trace_events *events)

{

	struct trace_events *tevent = events;

	struct trace_events *free_event;



	while (tevent) {

		free_event = tevent;



		tevent = tevent->next;



		free(free_event->system);

		free(free_event);

	}

}



/*

 * trace_event_alloc - alloc and parse a single trace event

 */

struct trace_events *trace_event_alloc(const char *event_string)

{

	struct trace_events *tevent;



	tevent = calloc(1, sizeof(*tevent));

	if (!tevent)

		return NULL;



	tevent->system = strdup(event_string);

	if (!tevent->system) {

		free(tevent);

		return NULL;

	}



	tevent->event = strstr(tevent->system, ":");

	if (tevent->event) {

		*tevent->event = '\0';

		tevent->event = &tevent->event[1];

	}



	return tevent;

}



/*

 * trace_events_disable - disable all trace events

 */

void trace_events_disable(struct trace_instance *instance,

			  struct trace_events *events)

{

	struct trace_events *tevent = events;



	if (!events)

		return;



	while (tevent) {

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

		if (tevent->enabled)

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



		tevent->enabled = 0;

		tevent = tevent->next;

	}

}



/*

 * trace_events_enable - enable all events

 */

int trace_events_enable(struct trace_instance *instance,

			struct trace_events *events)

{

	struct trace_events *tevent = events;

	int retval;



	while (tevent) {

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

		retval = tracefs_event_enable(instance->inst, tevent->system, tevent->event);

		if (retval < 0) {

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

				tevent->event ? : "*");

			return 1;

		}





		tevent->enabled = 1;

		tevent = tevent->next;

	}



	return 0;

}



/*

 * trace_events_destroy - disable and free all trace events

 */

void trace_events_destroy(struct trace_instance *instance,

			  struct trace_events *events)

{

	if (!events)

		return;



	trace_events_disable(instance, events);

	trace_events_free(events);

}

tools/tracing/rtla/src/trace.h

+15 −0
Original line number Diff line number Diff line
@@ -2,6 +2,13 @@ 
#include <tracefs.h>

#include <stddef.h>



struct trace_events {

	struct trace_events *next;

	char *system;

	char *event;

	char enabled;

};



struct trace_instance {

	struct tracefs_instance		*inst;

	struct tep_handle		*tep;
@@ -25,3 +32,11 @@ void destroy_instance(struct tracefs_instance *inst); 
int save_trace_to_file(struct tracefs_instance *inst, const char *filename);

int collect_registered_events(struct tep_event *tep, struct tep_record *record,

			      int cpu, void *context);



struct trace_events *trace_event_alloc(const char *event_string);

void trace_events_disable(struct trace_instance *instance,

			  struct trace_events *events);

void trace_events_destroy(struct trace_instance *instance,

			  struct trace_events *events);

int trace_events_enable(struct trace_instance *instance,

			  struct trace_events *events);