This is a note to let you know that I've just added the patch titled perf stat: Fix --metric-only --json output to the 6.1-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: perf-stat-fix-metric-only-json-output.patch and it can be found in the queue-6.1 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit e41f5e063a4edae9d4d4f17ecf9e761f911b7a2b Author: Namhyung Kim <namhyung@xxxxxxxxxx> Date: Mon Nov 7 13:33:10 2022 -0800 perf stat: Fix --metric-only --json output [ Upstream commit fdc7d6082459aa6705dd39b827214f6cfc1fa054 ] Currently it prints all metric headers for JSON output. But actually it skips some metrics with valid_only_metric(). So the output looks like: $ perf stat --metric-only --json true {"unit" : "CPUs utilized", "unit" : "/sec", "unit" : "/sec", "unit" : "/sec", "unit" : "GHz", "unit" : "insn per cycle", "unit" : "/sec", "unit" : "branch-misses of all branches"} {"metric-value" : "3.861"}{"metric-value" : "0.79"}{"metric-value" : "3.04"} As you can see there are 8 units in the header but only 3 metric-values are there. It should skip the unused headers as well. Also each unit should be printed as a separate object like metric values. With this patch: $ perf stat --metric-only --json true {"unit" : "GHz"}{"unit" : "insn per cycle"}{"unit" : "branch-misses of all branches"} {"metric-value" : "4.166"}{"metric-value" : "0.73"}{"metric-value" : "2.96"} Fixes: df936cadfb58ba93 ("perf stat: Add JSON output option") Signed-off-by: Namhyung Kim <namhyung@xxxxxxxxxx> Cc: Adrian Hunter <adrian.hunter@xxxxxxxxx> Cc: Claire Jensen <cjense@xxxxxxxxxx> Cc: Ian Rogers <irogers@xxxxxxxxxx> Cc: Ingo Molnar <mingo@xxxxxxxxxx> Cc: James Clark <james.clark@xxxxxxx> Cc: Jiri Olsa <jolsa@xxxxxxxxxx> Cc: Kan Liang <kan.liang@xxxxxxxxxxxxxxx> Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx> Cc: Xing Zhengjun <zhengjun.xing@xxxxxxxxxxxxxxx> Link: https://lore.kernel.org/r/20221107213314.3239159-6-namhyung@xxxxxxxxxx Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/tools/perf/util/stat-display.c b/tools/perf/util/stat-display.c index 8e99818cf023..3023f3993ed5 100644 --- a/tools/perf/util/stat-display.c +++ b/tools/perf/util/stat-display.c @@ -430,12 +430,12 @@ static void print_metric_header(struct perf_stat_config *config, os->evsel->priv != os->evsel->evlist->selected->priv) return; - if (!valid_only_metric(unit) && !config->json_output) + if (!valid_only_metric(unit)) return; unit = fixunit(tbuf, os->evsel, unit); if (config->json_output) - fprintf(os->fh, "\"unit\" : \"%s\"", unit); + fprintf(os->fh, "{\"unit\" : \"%s\"}", unit); else if (config->csv_output) fprintf(os->fh, "%s%s", unit, config->csv_sep); else @@ -847,10 +847,6 @@ static void print_metric_headers(struct perf_stat_config *config, .new_line = new_line_metric, .force_header = true, }; - bool first = true; - - if (config->json_output && !config->interval) - fprintf(config->output, "{"); if (prefix && !config->json_output) fprintf(config->output, "%s", prefix); @@ -871,18 +867,12 @@ static void print_metric_headers(struct perf_stat_config *config, evlist__for_each_entry(evlist, counter) { os.evsel = counter; - if (!first && config->json_output) - fprintf(config->output, ", "); - first = false; - perf_stat__print_shadow_stats(config, counter, 0, 0, &out, &config->metric_events, &rt_stat); } - if (config->json_output) - fprintf(config->output, "}"); fputc('\n', config->output); } @@ -954,14 +944,8 @@ static void print_interval(struct perf_stat_config *config, } } - if ((num_print_interval == 0 || config->interval_clear) - && metric_only && !config->json_output) + if ((num_print_interval == 0 || config->interval_clear) && metric_only) print_metric_headers(config, evlist, " ", true); - if ((num_print_interval == 0 || config->interval_clear) - && metric_only && config->json_output) { - fprintf(output, "{"); - print_metric_headers(config, evlist, " ", true); - } if (++num_print_interval == 25) num_print_interval = 0; }