From dd566687ef33995b54d040765c7400812841db35 Mon Sep 17 00:00:00 2001 From: James Clark Date: Tue, 12 Nov 2024 16:00:44 +0000 Subject: [PATCH] perf stat: Document and simplify interval timestamps Rename 'prefix' to 'timestamp' because that's all it does, except in iostat mode where it's slightly overloaded, but still includes a timestamp. This reveals a problem with iostat and JSON mode so document this. Make it more explicit that these are printed in interval mode by changing 'if (prefix)' to 'if (interval)' which reveals an unnecessary 'else if (... && !interval)' which can be removed. Signed-off-by: James Clark Tested-by: Ian Rogers Cc: Adrian Hunter Cc: Alexander Shishkin Cc: Ingo Molnar Cc: Jiri Olsa Cc: Kan Liang Cc: Mark Rutland Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Tim Chen Cc: Yicong Yang Link: https://lore.kernel.org/r/20241112160048.951213-5-james.clark@linaro.org Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/arch/x86/util/iostat.c | 4 +++ tools/perf/util/stat-display.c | 45 +++++++++++++++---------------- 2 files changed, 25 insertions(+), 24 deletions(-) diff --git a/tools/perf/arch/x86/util/iostat.c b/tools/perf/arch/x86/util/iostat.c index 366b44d0bb7e..00f645a0c18a 100644 --- a/tools/perf/arch/x86/util/iostat.c +++ b/tools/perf/arch/x86/util/iostat.c @@ -403,6 +403,10 @@ void iostat_prefix(struct evlist *evlist, struct iio_root_port *rp = evlist->selected->priv; if (rp) { + /* + * TODO: This is the incorrect format in JSON mode. + * See prepare_timestamp() + */ if (ts) sprintf(prefix, "%6lu.%09lu%s%04x:%02x%s", ts->tv_sec, ts->tv_nsec, diff --git a/tools/perf/util/stat-display.c b/tools/perf/util/stat-display.c index aa74543ae298..8377e24602dd 100644 --- a/tools/perf/util/stat-display.c +++ b/tools/perf/util/stat-display.c @@ -118,7 +118,8 @@ struct outstate { FILE *fh; bool newline; bool first; - const char *prefix; + /* Lines are timestamped in --interval-print mode */ + char timestamp[64]; int nfields; int aggr_nr; struct aggr_cpu_id id; @@ -419,8 +420,8 @@ static inline void __new_line_std_csv(struct perf_stat_config *config, struct outstate *os) { fputc('\n', os->fh); - if (os->prefix) - fputs(os->prefix, os->fh); + if (config->interval) + fputs(os->timestamp, os->fh); aggr_printout(config, os, os->evsel, os->id, os->aggr_nr); } @@ -523,8 +524,8 @@ static void new_line_json(struct perf_stat_config *config, void *ctx) fputs("\n{", os->fh); os->first = true; - if (os->prefix) - json_out(os, "%s", os->prefix); + if (config->interval) + json_out(os, "%s", os->timestamp); aggr_printout(config, os, os->evsel, os->id, os->aggr_nr); } @@ -1091,13 +1092,13 @@ static void print_counter_aggrdata(struct perf_stat_config *config, os->first = true; fputc('{', output); } - if (os->prefix) { + if (config->interval) { if (config->json_output) - json_out(os, "%s", os->prefix); + json_out(os, "%s", os->timestamp); else - fprintf(output, "%s", os->prefix); + fprintf(output, "%s", os->timestamp); } else if (config->summary && config->csv_output && - !config->no_csv_summary && !config->interval) + !config->no_csv_summary) fprintf(output, "%s%s", "summary", config->csv_sep); } @@ -1124,11 +1125,11 @@ static void print_metric_begin(struct perf_stat_config *config, if (config->json_output) fputc('{', config->output); - if (os->prefix) { + if (config->interval) { if (config->json_output) - json_out(os, "%s", os->prefix); + json_out(os, "%s", os->timestamp); else - fprintf(config->output, "%s", os->prefix); + fprintf(config->output, "%s", os->timestamp); } evsel = evlist__first(evlist); id = config->aggr_map->map[aggr_idx]; @@ -1349,20 +1350,20 @@ static void print_metric_headers(struct perf_stat_config *config, fputc('\n', config->output); } -static void prepare_interval(struct perf_stat_config *config, - char *prefix, size_t len, struct timespec *ts) +static void prepare_timestamp(struct perf_stat_config *config, + struct outstate *os, struct timespec *ts) { if (config->iostat_run) return; if (config->json_output) - scnprintf(prefix, len, "\"interval\" : %lu.%09lu", + scnprintf(os->timestamp, sizeof(os->timestamp), "\"interval\" : %lu.%09lu", (unsigned long) ts->tv_sec, ts->tv_nsec); else if (config->csv_output) - scnprintf(prefix, len, "%lu.%09lu%s", + scnprintf(os->timestamp, sizeof(os->timestamp), "%lu.%09lu%s", (unsigned long) ts->tv_sec, ts->tv_nsec, config->csv_sep); else - scnprintf(prefix, len, "%6lu.%09lu ", + scnprintf(os->timestamp, sizeof(os->timestamp), "%6lu.%09lu ", (unsigned long) ts->tv_sec, ts->tv_nsec); } @@ -1685,9 +1686,7 @@ void evlist__print_counters(struct evlist *evlist, struct perf_stat_config *conf int argc, const char **argv) { bool metric_only = config->metric_only; - int interval = config->interval; struct evsel *counter; - char buf[64]; struct outstate os = { .fh = config->output, .first = true, @@ -1698,10 +1697,8 @@ void evlist__print_counters(struct evlist *evlist, struct perf_stat_config *conf if (config->iostat_run) evlist->selected = evlist__first(evlist); - if (interval) { - os.prefix = buf; - prepare_interval(config, buf, sizeof(buf), ts); - } + if (config->interval) + prepare_timestamp(config, &os, ts); print_header(config, _target, evlist, argc, argv); @@ -1720,7 +1717,7 @@ void evlist__print_counters(struct evlist *evlist, struct perf_stat_config *conf case AGGR_THREAD: case AGGR_GLOBAL: if (config->iostat_run) { - iostat_print_counters(evlist, config, ts, buf, + iostat_print_counters(evlist, config, ts, os.timestamp, (iostat_print_counter_t)print_counter, &os); } else if (config->cgroup_list) { print_cgroup_counter(config, evlist, &os);