[PATCH 3/4] perf stat: Add --metrics-file option

[Jiri Olsa <jolsa@kernel.org>]

Adding --metrics-file option that allows to specify metrics
in the file.

It's now possible to define metrics in file and use them like:

  $ cat metrics
  // IPC
  mine1 = inst_retired.any / cpu_clk_unhalted.thread;

  /* DECODED_ICACHE_UOPS% */
  mine2 = 100 * (idq.dsb_uops / (idq.ms_uops + idq.mite_uops + idq.dsb_uops + lsd.uops));

  $ sudo perf stat --metrics-file ./metrics -M mine1,mine2 -a -I 1000 --metric-only
  #           time                mine1                mine2
       1.000997184                 0.41                18.47
       2.002479737                 0.57                22.46
       3.003932935                 0.40                17.52
  ...

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
---
 tools/perf/Documentation/perf-stat.txt | 77 ++++++++++++++++++++++++++
 tools/perf/builtin-stat.c              |  7 ++-
 tools/perf/util/metricgroup.c          | 69 ++++++++++++++++++++---
 tools/perf/util/metricgroup.h          |  3 +-
 tools/perf/util/stat.h                 |  1 +
 5 files changed, 147 insertions(+), 10 deletions(-)

diff --git a/tools/perf/Documentation/perf-stat.txt b/tools/perf/Documentation/perf-stat.txt
index 3fb5028aef08..9f0a646d719c 100644
--- a/tools/perf/Documentation/perf-stat.txt
+++ b/tools/perf/Documentation/perf-stat.txt
@@ -266,6 +266,10 @@ For a group all metrics from the group are added.
 The events from the metrics are automatically measured.
 See perf list output for the possble metrics and metricgroups.
 
+--metrics-file file::
+Read metrics definitions from file in addition to compiled in metrics.
+Please check the file's syntax details in METRICS FILE section below.
+
 -A::
 --no-aggr::
 Do not aggregate counts across all monitored CPUs.
@@ -404,6 +408,79 @@ The fields are in this order:
 
 Additional metrics may be printed with all earlier fields being empty.
 
+METRICS FILE
+------------
+The file with metrics has following syntax:
+
+  NAME = EXPRESSION ;
+  NAME = EXPRESSION ;
+  ...
+
+where NAME is unique identifier of the metric, which is later used in
+perf stat as -M option argument (see below).
+
+The EXPRESSION is the metric's formula with following grammar:
+
+  EXPR: EVENT
+  EXPR: EXPR if EXPR else EXPR
+  EXPR: NUMBER
+  EXPR: EXPR | EXPR
+  EXPR: EXPR & EXPR
+  EXPR: EXPR ^ EXPR
+  EXPR: EXPR + EXPR
+  EXPR: EXPR - EXPR
+  EXPR: EXPR * EXPR
+  EXPR: EXPR / EXPR
+  EXPR: EXPR % EXPR
+  EXPR: - EXPR
+  EXPR: ( EXPR )
+  EXPR: min( EXPR, EXPR )
+  EXPR: max( EXPR, EXPR )
+  EXPR: #smt_on
+
+where:
+
+  EVENT is monitored event name
+  min returns smaller of 2 expressions
+  max returns bigger of 2 expressions
+  #smt_on returns true if SMT is enabled
+
+The metric's definition can be spread across multiple lines and it's finished
+with ';' character.
+
+The syntax allows for C style comments:
+
+  // single line
+  /* multiple
+              lines */
+
+Metrics file example with 2 custom metrics mine1 and mine2:
+
+  $ cat metrics
+  // IPC
+  mine1 = inst_retired.any / cpu_clk_unhalted.thread;
+
+   /* DECODED_ICACHE_UOPS% */
+  mine2 = 100 * (idq.dsb_uops / (idq.ms_uops + idq.mite_uops + idq.dsb_uops + lsd.uops));
+
+  $ sudo perf stat --metrics-file ./metrics -M mine1,mine2 -a -I 1000 --metric-only
+  #           time                mine1                mine2
+       1.000997184                 0.41                18.47
+       2.002479737                 0.57                22.46
+       3.003932935                 0.40                17.52
+  ...
+
+
+It's possible to mix custom metrics with compiled-in metrics in one -M argument:
+
+  $ sudo perf stat --metrics-file ./metrics -M mine1,mine2,IPC -a -I 1000 --metric-only
+  #           time                mine1                mine2                  IPC
+       1.001142007                 0.85                22.33                 0.85
+       2.002460174                 0.86                23.37                 0.86
+       3.003969795                 1.03                23.93                 1.03
+  ...
+
+
 SEE ALSO
 --------
 linkperf:perf-top[1], linkperf:perf-list[1]
diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c
index e0c1ad23c768..5eda298654a8 100644
--- a/tools/perf/builtin-stat.c
+++ b/tools/perf/builtin-stat.c
@@ -840,7 +840,8 @@ static int parse_metric_groups(const struct option *opt,
 			       const char *str,
 			       int unset __maybe_unused)
 {
-	return metricgroup__parse_groups(opt, str, &stat_config.metric_events);
+	return metricgroup__parse_groups(opt, str, &stat_config.metric_events,
+					 stat_config.metrics_file);
 }
 
 static struct option stat_options[] = {
@@ -925,6 +926,8 @@ static struct option stat_options[] = {
 	OPT_CALLBACK('M', "metrics", &evsel_list, "metric/metric group list",
 		     "monitor specified metrics or metric groups (separated by ,)",
 		     parse_metric_groups),
+	OPT_STRING(0, "metrics-file", &stat_config.metrics_file, "file path",
+		   "file with metrics definitions"),
 	OPT_BOOLEAN_FLAG(0, "all-kernel", &stat_config.all_kernel,
 			 "Configure all used events to run in kernel space.",
 			 PARSE_OPT_EXCLUSIVE),
@@ -1442,7 +1445,7 @@ static int add_default_attributes(void)
 			struct option opt = { .value = &evsel_list };
 
 			return metricgroup__parse_groups(&opt, "transaction",
-							 &stat_config.metric_events);
+							 &stat_config.metric_events, NULL);
 		}
 
 		if (pmu_have_event("cpu", "cycles-ct") &&
diff --git a/tools/perf/util/metricgroup.c b/tools/perf/util/metricgroup.c
index b071df373f8b..3b4d5bdb5ac6 100644
--- a/tools/perf/util/metricgroup.c
+++ b/tools/perf/util/metricgroup.c
@@ -527,17 +527,17 @@ static int __metricgroup__add_metric(struct strbuf *events,
 }
 
 static int metricgroup__add_metric(const char *metric, struct strbuf *events,
-				   struct list_head *group_list)
+				   struct list_head *group_list,
+				   struct expr_parse_ctx *ctx)
 {
 	struct pmu_events_map *map = perf_pmu__find_map(NULL);
-	struct pmu_event *pe;
 	int i, ret = -EINVAL;
 
 	if (!map)
 		return 0;
 
 	for (i = 0; ; i++) {
-		pe = &map->table[i];
+		struct pmu_event *pe = &map->table[i];
 
 		if (!pe->name && !pe->metric_group && !pe->metric_name)
 			break;
@@ -567,15 +567,59 @@ static int metricgroup__add_metric(const char *metric, struct strbuf *events,
 				break;
 		}
 	}
+
+	if (!ctx->num_custom || ret == -ENOMEM)
+		return ret;
+
+	for (i = 0; i < ctx->num_custom; i++) {
+		struct pmu_event pe = { 0 };
+
+		if (!match_metric(ctx->custom[i].name, metric))
+			continue;
+
+		pe.metric_name = strdup(ctx->custom[i].name);
+		pe.metric_expr = strdup(ctx->custom[i].expr);
+
+		if (!pe.metric_name && !pe.metric_expr)
+			return -ENOMEM;
+
+		ret = __metricgroup__add_metric(events, group_list, &pe, 1);
+		if (ret) {
+			free((char *) pe.metric_name);
+			free((char *) pe.metric_expr);
+			break;
+		}
+	}
+
 	return ret;
 }
 
 static int metricgroup__add_metric_list(const char *list, struct strbuf *events,
-				        struct list_head *group_list)
+					struct list_head *group_list,
+					const char *metrics_file)
 {
+	struct expr_parse_ctx ctx = { 0 };
 	char *llist, *nlist, *p;
 	int ret = -EINVAL;
 
+	if (metrics_file) {
+		size_t size;
+		char *buf;
+
+		if (filename__read_str(metrics_file, &buf, &size)) {
+			pr_err("failed to read metrics file: %s\n", metrics_file);
+			return -1;
+		}
+
+		expr__ctx_init(&ctx);
+		ret = expr__parse_custom(&ctx, buf);
+		free(buf);
+		if (ret) {
+			pr_err("failed to parse metrics file: %s\n", metrics_file);
+			return -1;
+		}
+	}
+
 	nlist = strdup(list);
 	if (!nlist)
 		return -ENOMEM;
@@ -585,7 +629,7 @@ static int metricgroup__add_metric_list(const char *list, struct strbuf *events,
 	strbuf_addf(events, "%s", "");
 
 	while ((p = strsep(&llist, ",")) != NULL) {
-		ret = metricgroup__add_metric(p, events, group_list);
+		ret = metricgroup__add_metric(p, events, group_list, &ctx);
 		if (ret == -EINVAL) {
 			fprintf(stderr, "Cannot find metric or group `%s'\n",
 					p);
@@ -597,6 +641,15 @@ static int metricgroup__add_metric_list(const char *list, struct strbuf *events,
 	if (!ret)
 		metricgroup___watchdog_constraint_hint(NULL, true);
 
+	if (metrics_file) {
+		int i;
+
+		for (i = 0; i < ctx.num_custom; i++) {
+			zfree(&ctx.custom[i].name);
+			zfree(&ctx.custom[i].expr);
+		}
+	}
+
 	return ret;
 }
 
@@ -616,7 +669,8 @@ static void metricgroup__free_egroups(struct list_head *group_list)
 
 int metricgroup__parse_groups(const struct option *opt,
 			   const char *str,
-			   struct rblist *metric_events)
+			   struct rblist *metric_events,
+			   const char *metrics_file)
 {
 	struct parse_events_error parse_error;
 	struct evlist *perf_evlist = *(struct evlist **)opt->value;
@@ -626,7 +680,8 @@ int metricgroup__parse_groups(const struct option *opt,
 
 	if (metric_events->nr_entries == 0)
 		metricgroup__rblist_init(metric_events);
-	ret = metricgroup__add_metric_list(str, &extra_events, &group_list);
+	ret = metricgroup__add_metric_list(str, &extra_events, &group_list,
+					   metrics_file);
 	if (ret)
 		return ret;
 	pr_debug("adding %s\n", extra_events.buf);
diff --git a/tools/perf/util/metricgroup.h b/tools/perf/util/metricgroup.h
index 6b09eb30b4ec..33dcdcad15dd 100644
--- a/tools/perf/util/metricgroup.h
+++ b/tools/perf/util/metricgroup.h
@@ -30,7 +30,8 @@ struct metric_event *metricgroup__lookup(struct rblist *metric_events,
 					 bool create);
 int metricgroup__parse_groups(const struct option *opt,
 			const char *str,
-			struct rblist *metric_events);
+			struct rblist *metric_events,
+			const char *metrics_file);
 
 void metricgroup__print(bool metrics, bool groups, char *filter,
 			bool raw, bool details);
diff --git a/tools/perf/util/stat.h b/tools/perf/util/stat.h
index b4fdfaa7f2c0..57c4c7695aaf 100644
--- a/tools/perf/util/stat.h
+++ b/tools/perf/util/stat.h
@@ -123,6 +123,7 @@ struct perf_stat_config {
 	struct runtime_stat	*stats;
 	int			 stats_num;
 	const char		*csv_sep;
+	const char		*metrics_file;
 	struct stats		*walltime_nsecs_stats;
 	struct rusage		 ru_data;
 	struct perf_cpu_map		*aggr_map;
-- 
2.25.4