perf tools: Parse aux-action

Add parsing for aux-action to accept "pause", "resume" or "start-paused"
values.

"start-paused" is valid only for AUX area events.

"pause" and "resume" are valid only for events grouped with an AUX area
event as the group leader.  However, like with aux-output, the events
will be automatically grouped if they are not currently in a group, and
the AUX area event precedes the other events.

Reviewed-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Acked-by: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Leo Yan <leo.yan@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/r/20241216070244.14450-4-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/Documentation/perf-record.txt

@@ -68,6 +68,10 @@ OPTIONS
 		    like this: name=\'CPU_CLK_UNHALTED.THREAD:cmask=0x1\'.
 	  - 'aux-output': Generate AUX records instead of events. This requires
 			  that an AUX area event is also provided.
+	  - 'aux-action': "pause" or "resume" to pause or resume an AUX
+			  area event (the group leader) when this event occurs.
+			  "start-paused" on an AUX area event itself, will
+			  start in a paused state.
 	  - 'aux-sample-size': Set sample size for AUX area sampling. If the
 	  '--aux-sample' option has been used, set aux-sample-size=0 to disable
 	  AUX area sampling for the event.

tools/perf/builtin-record.c

@@ -860,7 +860,9 @@ static int record__auxtrace_init(struct record *rec)
 	if (err)
 		return err;
 
-	auxtrace_regroup_aux_output(rec->evlist);
+	err = auxtrace_parse_aux_action(rec->evlist);
+	if (err)
+		return err;
 
 	return auxtrace_parse_filters(rec->evlist);
 }

tools/perf/util/auxtrace.c

@@ -810,19 +810,76 @@ no_opt:
 	return auxtrace_validate_aux_sample_size(evlist, opts);
 }
 
-void auxtrace_regroup_aux_output(struct evlist *evlist)
+static struct aux_action_opt {
+	const char *str;
+	u32 aux_action;
+	bool aux_event_opt;
+} aux_action_opts[] = {
+	{"start-paused", BIT(0), true},
+	{"pause",        BIT(1), false},
+	{"resume",       BIT(2), false},
+	{.str = NULL},
+};
+
+static const struct aux_action_opt *auxtrace_parse_aux_action_str(const char *str)
+{
+	const struct aux_action_opt *opt;
+
+	if (!str)
+		return NULL;
+
+	for (opt = aux_action_opts; opt->str; opt++)
+		if (!strcmp(str, opt->str))
+			return opt;
+
+	return NULL;
+}
+
+int auxtrace_parse_aux_action(struct evlist *evlist)
 {
-	struct evsel *evsel, *aux_evsel = NULL;
 	struct evsel_config_term *term;
+	struct evsel *aux_evsel = NULL;
+	struct evsel *evsel;
 
 	evlist__for_each_entry(evlist, evsel) {
-		if (evsel__is_aux_event(evsel))
+		bool is_aux_event = evsel__is_aux_event(evsel);
+		const struct aux_action_opt *opt;
+
+		if (is_aux_event)
 			aux_evsel = evsel;
-		term = evsel__get_config_term(evsel, AUX_OUTPUT);
+		term = evsel__get_config_term(evsel, AUX_ACTION);
+		if (!term) {
+			if (evsel__get_config_term(evsel, AUX_OUTPUT))
+				goto regroup;
+			continue;
+		}
+		opt = auxtrace_parse_aux_action_str(term->val.str);
+		if (!opt) {
+			pr_err("Bad aux-action '%s'\n", term->val.str);
+			return -EINVAL;
+		}
+		if (opt->aux_event_opt && !is_aux_event) {
+			pr_err("aux-action '%s' can only be used with AUX area event\n",
+			       term->val.str);
+			return -EINVAL;
+		}
+		if (!opt->aux_event_opt && is_aux_event) {
+			pr_err("aux-action '%s' cannot be used for AUX area event itself\n",
+			       term->val.str);
+			return -EINVAL;
+		}
+		evsel->core.attr.aux_action = opt->aux_action;
+regroup:
 		/* If possible, group with the AUX event */
-		if (term && aux_evsel)
+		if (aux_evsel)
 			evlist__regroup(evlist, aux_evsel, evsel);
+		if (!evsel__is_aux_event(evsel__leader(evsel))) {
+			pr_err("Events with aux-action must have AUX area event group leader\n");
+			return -EINVAL;
+		}
 	}
+
+	return 0;
 }
 
 struct auxtrace_record *__weak

tools/perf/util/auxtrace.h

@@ -578,7 +578,7 @@ int auxtrace_parse_snapshot_options(struct auxtrace_record *itr,
 int auxtrace_parse_sample_options(struct auxtrace_record *itr,
 				  struct evlist *evlist,
 				  struct record_opts *opts, const char *str);
-void auxtrace_regroup_aux_output(struct evlist *evlist);
+int auxtrace_parse_aux_action(struct evlist *evlist);
 int auxtrace_record__options(struct auxtrace_record *itr,
 			     struct evlist *evlist,
 			     struct record_opts *opts);
@@ -799,8 +799,10 @@ int auxtrace_parse_sample_options(struct auxtrace_record *itr __maybe_unused,
 }
 
 static inline
-void auxtrace_regroup_aux_output(struct evlist *evlist __maybe_unused)
+int auxtrace_parse_aux_action(struct evlist *evlist __maybe_unused)
 {
+	pr_err("AUX area tracing not supported\n");
+	return -EINVAL;
 }
 
 static inline

tools/perf/util/evsel.c

@@ -1152,6 +1152,7 @@ static void evsel__apply_config_terms(struct evsel *evsel,
 			attr->aux_output = term->val.aux_output ? 1 : 0;
 			break;
 		case EVSEL__CONFIG_TERM_AUX_ACTION:
+			/* Already applied by auxtrace */
 			break;
 		case EVSEL__CONFIG_TERM_AUX_SAMPLE_SIZE:
 			/* Already applied by auxtrace */