[PATCH v1 6/8] perf stat: Delay metric parsing

Ian Rogers
2022-08-30T16:50:22Z

Having metric parsing as part of argument processing causes issues as
flags like metric-no-group may be specified later. It also denies the
opportunity to optimize the events on SMT systems where fewer events
may be possible if we know the target is system-wide. Move metric
parsing to after command line option parsing. Because of how stat runs
this moves the parsing after record/report which fail to work with
metrics currently anyway.

Signed-off-by: Ian Rogers <irogers@google.com>
---
tools/perf/builtin-stat.c | 48 ++++++++++++++++++++++++-----------
tools/perf/util/metricgroup.c | 3 +--
tools/perf/util/metricgroup.h | 2 +-
3 files changed, 35 insertions(+), 18 deletions(-)

diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c
index 7fb81a44672d..c813b1aa7d7c 100644
--- a/tools/perf/builtin-stat.c
+++ b/tools/perf/builtin-stat.c
@@ -191,6 +191,7 @@ static bool append_file;
static bool interval_count;
static const char *output_name;
static int output_fd;
+static char *metrics;

struct perf_stat {
bool record;
@@ -1147,14 +1148,21 @@ static int enable_metric_only(const struct option *opt __maybe_unused,
return 0;
}

-static int parse_metric_groups(const struct option *opt,
+static int append_metric_groups(const struct option *opt __maybe_unused,
const char *str,
int unset __maybe_unused)
{
- return metricgroup__parse_groups(opt, str,
- stat_config.metric_no_group,
- stat_config.metric_no_merge,
- &stat_config.metric_events);
+ if (metrics) {
+ char *tmp;
+
+ if (asprintf(&tmp, "%s,%s", metrics, str) < 0)
+ return -ENOMEM;
+ free(metrics);
+ metrics = tmp;
+ } else {
+ metrics = strdup(str);
+ }
+ return 0;
}

static int parse_control_option(const struct option *opt,
@@ -1298,7 +1306,7 @@ static struct option stat_options[] = {
"measure SMI cost"),
OPT_CALLBACK('M', "metrics", &evsel_list, "metric/metric group list",
"monitor specified metrics or metric groups (separated by ,)",
- parse_metric_groups),
+ append_metric_groups),
OPT_BOOLEAN_FLAG(0, "all-kernel", &stat_config.all_kernel,
"Configure all used events to run in kernel space.",
PARSE_OPT_EXCLUSIVE),
@@ -1791,11 +1799,9 @@ static int add_default_attributes(void)
* on an architecture test for such a metric name.
*/
if (metricgroup__has_metric("transaction")) {
- struct option opt = { .value = &evsel_list };
-
- return metricgroup__parse_groups(&opt, "transaction",
+ return metricgroup__parse_groups(evsel_list, "transaction",
stat_config.metric_no_group,
- stat_config.metric_no_merge,
+ stat_config.metric_no_merge,
&stat_config.metric_events);
}

@@ -2260,8 +2266,6 @@ int cmd_stat(int argc, const char **argv)
argc = parse_options_subcommand(argc, argv, stat_options, stat_subcommands,
(const char **) stat_usage,
PARSE_OPT_STOP_AT_NON_OPTION);
- perf_stat__collect_metric_expr(evsel_list);
- perf_stat__init_shadow_stats();

if (stat_config.csv_sep) {
stat_config.csv_output = true;
@@ -2428,6 +2432,23 @@ int cmd_stat(int argc, const char **argv)
target.system_wide = true;
}

+ if ((stat_config.aggr_mode == AGGR_THREAD) && (target.system_wide))
+ target.per_thread = true;
+
+ /*
+ * Metric parsing needs to be delayed as metrics may optimize events
+ * knowing the target is system-wide.
+ */
+ if (metrics) {
+ metricgroup__parse_groups(evsel_list, metrics,
+ stat_config.metric_no_group,
+ stat_config.metric_no_merge,
+ &stat_config.metric_events);
+ zfree(&metrics);
+ }
+ perf_stat__collect_metric_expr(evsel_list);
+ perf_stat__init_shadow_stats();
+
if (add_default_attributes())
goto out;

@@ -2447,9 +2468,6 @@ int cmd_stat(int argc, const char **argv)
}
}

- if ((stat_config.aggr_mode == AGGR_THREAD) && (target.system_wide))
- target.per_thread = true;
-
if (evlist__fix_hybrid_cpus(evsel_list, target.cpu_list)) {
pr_err("failed to use cpu list %s\n", target.cpu_list);
goto out;
diff --git a/tools/perf/util/metricgroup.c b/tools/perf/util/metricgroup.c
index b144c3e35264..9151346a16ab 100644
--- a/tools/perf/util/metricgroup.c
+++ b/tools/perf/util/metricgroup.c
@@ -1646,13 +1646,12 @@ static int parse_groups(struct evlist *perf_evlist, const char *str,
return ret;
}

-int metricgroup__parse_groups(const struct option *opt,
+int metricgroup__parse_groups(struct evlist *perf_evlist,
const char *str,
bool metric_no_group,
bool metric_no_merge,
struct rblist *metric_events)
{
- struct evlist *perf_evlist = *(struct evlist **)opt->value;
const struct pmu_events_table *table = pmu_events_table__find();

if (!table)
diff --git a/tools/perf/util/metricgroup.h b/tools/perf/util/metricgroup.h
index 016b3b1a289a..af9ceadaec0f 100644
--- a/tools/perf/util/metricgroup.h
+++ b/tools/perf/util/metricgroup.h
@@ -64,7 +64,7 @@ struct metric_expr {
struct metric_event *metricgroup__lookup(struct rblist *metric_events,
struct evsel *evsel,
bool create);
-int metricgroup__parse_groups(const struct option *opt,
+int metricgroup__parse_groups(struct evlist *perf_evlist,
const char *str,
bool metric_no_group,
bool metric_no_merge,
--
2.37.2.672.g94769d06f0-goog