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Commit 19658171 authored by Jiri Olsa's avatar Jiri Olsa Committed by Arnaldo Carvalho de Melo
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perf tools: Enhance parsing events tracepoint error output 



Enhancing parsing events tracepoint error output. Adding
more verbose output when the tracepoint is not found or
the tracing event path cannot be access.

  $ sudo perf record -e sched:sched_krava ls
  event syntax error: 'sched:sched_krava'
                       \___ unknown tracepoint

  Error:  File /sys/kernel/debug/tracing//tracing/events/sched/sched_krava not found.
  Hint:   Perhaps this kernel misses some CONFIG_ setting to enable this feature?.

  Run 'perf list' for a list of valid events
  ...

  $ perf record -e sched:sched_krava ls
  event syntax error: 'sched:sched_krava'
                       \___ can't access trace events

  Error:  No permissions to read /sys/kernel/debug/tracing//tracing/events/sched/sched_krava
  Hint:   Try 'sudo mount -o remount,mode=755 /sys/kernel/debug'

  Run 'perf list' for a list of valid events
  ...

Signed-off-by: default avatarJiri Olsa <jolsa@kernel.org>
Tested-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
Cc: Raphael Beamonte <raphael.beamonte@gmail.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1441615087-13886-6-git-send-email-jolsa@kernel.org


Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent 8dd2a131

tools/perf/util/parse-events.c

+32 −3
Original line number Diff line number Diff line
@@ -387,6 +387,33 @@ int parse_events_add_cache(struct list_head *list, int *idx, 
	return add_event(list, idx, &attr, name, NULL);

}



static void tracepoint_error(struct parse_events_error *error, int err,

			     char *sys, char *name)

{

	char help[BUFSIZ];



	/*

	 * We get error directly from syscall errno ( > 0),

	 * or from encoded pointer's error ( < 0).

	 */

	err = abs(err);



	switch (err) {

	case EACCES:

		error->str = strdup("can't access trace events");

		break;

	case ENOENT:

		error->str = strdup("unknown tracepoint");

		break;

	default:

		error->str = strdup("failed to add tracepoint");

		break;

	}



	tracing_path__strerror_open_tp(err, help, sizeof(help), sys, name);

	error->help = strdup(help);

}



static int add_tracepoint(struct list_head *list, int *idx,

			  char *sys_name, char *evt_name,

			  struct parse_events_error *error __maybe_unused)
@@ -394,8 +421,10 @@ static int add_tracepoint(struct list_head *list, int *idx, 
	struct perf_evsel *evsel;



	evsel = perf_evsel__newtp_idx(sys_name, evt_name, (*idx)++);

	if (IS_ERR(evsel))

	if (IS_ERR(evsel)) {

		tracepoint_error(error, PTR_ERR(evsel), sys_name, evt_name);

		return PTR_ERR(evsel);

	}



	list_add_tail(&evsel->node, list);

	return 0;
@@ -413,7 +442,7 @@ static int add_tracepoint_multi_event(struct list_head *list, int *idx, 
	snprintf(evt_path, MAXPATHLEN, "%s/%s", tracing_events_path, sys_name);

	evt_dir = opendir(evt_path);

	if (!evt_dir) {

		perror("Can't open event dir");

		tracepoint_error(error, errno, sys_name, evt_name);

		return -1;

	}
@@ -453,7 +482,7 @@ static int add_tracepoint_multi_sys(struct list_head *list, int *idx, 


	events_dir = opendir(tracing_events_path);

	if (!events_dir) {

		perror("Can't open event dir");

		tracepoint_error(error, errno, sys_name, evt_name);

		return -1;

	}

tools/perf/util/parse-events.y

+9 −7
Original line number Diff line number Diff line
@@ -371,28 +371,30 @@ event_legacy_tracepoint: 
PE_NAME '-' PE_NAME ':' PE_NAME

{

	struct parse_events_evlist *data = _data;

	struct parse_events_error *error = data->error;

	struct list_head *list;

	char sys_name[128];

	snprintf(&sys_name, 128, "%s-%s", $1, $3);



	ALLOC_LIST(list);

	ABORT_ON(parse_events_add_tracepoint(list, &data->idx, &sys_name, $5, data->error));

	if (parse_events_add_tracepoint(list, &data->idx, &sys_name, $5, error)) {

		if (error)

			error->idx = @1.first_column;

		return -1;

	}

	$$ = list;

}

|

PE_NAME ':' PE_NAME

{

	struct parse_events_evlist *data = _data;

	struct parse_events_error *error = data->error;

	struct list_head *list;



	ALLOC_LIST(list);

	if (parse_events_add_tracepoint(list, &data->idx, $1, $3, data->error)) {

		struct parse_events_error *error = data->error;



		if (error) {

	if (parse_events_add_tracepoint(list, &data->idx, $1, $3, error)) {

		if (error)

			error->idx = @1.first_column;

			error->str = strdup("unknown tracepoint");

		}

		return -1;

	}

	$$ = list;