Commit 762a05c5 authored by Ian Rogers's avatar Ian Rogers Committed by Arnaldo Carvalho de Melo
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perf metric: Allow metrics with no events 



A metric may be a constant value, for example, some SMT metrics are
constant 0 if #smt_on is 0. If we eliminate all the events then there is
no printing. Fix this by forcing metrics like this to have a
duration_time tool event, previously the metric would fail when parsing
the events with a parse error.

Signed-off-by: default avatarIan Rogers <irogers@google.com>
Tested-by: default avatarJohn Garry <john.garry@huawei.com>
Acked-by: default avatarJiri Olsa <jolsa@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jin Yao <yao.jin@linux.intel.com>
Cc: Kajol Jain <kjain@linux.ibm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Clarke <pc@us.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sandeep Dasgupta <sdasgup@google.com>
Cc: Stephane Eranian <eranian@google.com>
Link: https://lore.kernel.org/r/20210923074616.674826-10-irogers@google.com


[ Reflow one __parse_events() call so that a ternary operation gets in a single line ]
Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent 114a9d6e

tools/perf/util/metricgroup.c

+56 −50
Original line number Diff line number Diff line
@@ -198,23 +198,22 @@ static struct evsel *find_evsel_group(struct evlist *perf_evlist, 
	struct evsel *ev, *current_leader = NULL;

	struct expr_id_data *val_ptr;

	int i = 0, matched_events = 0, events_to_match;

	const int idnum = (int)hashmap__size(pctx->ids);

	int idnum = (int)hashmap__size(pctx->ids);



	if (idnum != 0) {

		/*

	 * duration_time is always grouped separately, when events are grouped

	 * (ie has_constraint is false) then ignore it in the matching loop and

	 * add it to metric_events at the end.

		 * duration_time is always grouped separately, when events are

		 * grouped (ie has_constraint is false) then ignore it in the

		 * matching loop and add it to metric_events at the end.

		 */

	if (!has_constraint &&

	    hashmap__find(pctx->ids, "duration_time", (void **)&val_ptr))

		events_to_match = idnum - 1;

	else

		events_to_match = idnum;

		if (!has_constraint && hashmap__find(pctx->ids, "duration_time", (void **)&val_ptr))

			events_to_match--;



		evlist__for_each_entry(perf_evlist, ev) {

			/*

		 * Events with a constraint aren't grouped and match the first

		 * events available.

			 * Events with a constraint aren't grouped and match the

			 * first events available.

			 */

			if (has_constraint && ev->weak_group)

				continue;
@@ -223,21 +222,21 @@ static struct evsel *find_evsel_group(struct evlist *perf_evlist, 
				continue;

			if (!has_constraint && !evsel__has_leader(ev, current_leader)) {

				/*

			 * Start of a new group, discard the whole match and

			 * start again.

				 * Start of a new group, discard the whole match

				 * and start again.

				 */

				matched_events = 0;

			memset(metric_events, 0,

				sizeof(struct evsel *) * idnum);

				memset(metric_events, 0, sizeof(struct evsel *) * idnum);

				current_leader = evsel__leader(ev);

			}

			/*

		 * Check for duplicate events with the same name. For example,

		 * uncore_imc/cas_count_read/ will turn into 6 events per socket

		 * on skylakex. Only the first such event is placed in

		 * metric_events. If events aren't grouped then this also

		 * ensures that the same event in different sibling groups

		 * aren't both added to metric_events.

			 * Check for duplicate events with the same name. For

			 * example, uncore_imc/cas_count_read/ will turn into 6

			 * events per socket on skylakex. Only the first such

			 * event is placed in metric_events. If events aren't

			 * grouped then this also ensures that the same event in

			 * different sibling groups aren't both added to

			 * metric_events.

			 */

			if (contains_event(metric_events, matched_events, ev->name))

				continue;
@@ -248,15 +247,20 @@ static struct evsel *find_evsel_group(struct evlist *perf_evlist, 
			if (matched_events == events_to_match)

				break;

		}



	} else {

		/*

		 * There are no events to match, but we need to associate the

		 * metric with an event for printing. A duration_time event was

		 * parsed for this.

		 */

		idnum = 1;

		events_to_match = 0;

	}

	if (events_to_match != idnum) {

		/* Add the first duration_time. */

		evlist__for_each_entry(perf_evlist, ev) {

			if (!strcmp(ev->name, "duration_time")) {

		ev = evlist__find_evsel_by_str(perf_evlist, "duration_time");

		if (ev)

			metric_events[matched_events++] = ev;

				break;

			}

		}

	}



	if (matched_events != idnum) {
@@ -320,9 +324,10 @@ static int metricgroup__setup_events(struct list_head *groups, 
	list_for_each_entry (m, groups, nd) {

		struct evsel **metric_events;

		struct metric_ref *metric_refs = NULL;

		const size_t ids_size = hashmap__size(m->pctx->ids);



		metric_events = calloc(sizeof(void *),

				hashmap__size(m->pctx->ids) + 1);

				ids_size == 0 ? 2 : ids_size + 1);

		if (!metric_events) {

			ret = -ENOMEM;

			break;
@@ -1240,7 +1245,8 @@ static int parse_groups(struct evlist *perf_evlist, const char *str, 
		goto out;

	pr_debug("adding %s\n", extra_events.buf);

	bzero(&parse_error, sizeof(parse_error));

	ret = __parse_events(perf_evlist, extra_events.buf, &parse_error, fake_pmu);

	ret = __parse_events(perf_evlist, extra_events.len > 0 ? extra_events.buf : "duration_time",

			     &parse_error, fake_pmu);

	if (ret) {

		parse_events_print_error(&parse_error, extra_events.buf);

		goto out;