diff --git a/tools/perf/Documentation/perf-stat.txt b/tools/perf/Documentation/perf-stat.txt index b029ee728a0b..9f32f6cd558d 100644 --- a/tools/perf/Documentation/perf-stat.txt +++ b/tools/perf/Documentation/perf-stat.txt @@ -238,8 +238,9 @@ mode, use --per-node in addition to -a. (system-wide). -D msecs:: --delay msecs:: -After starting the program, wait msecs before measuring. This is useful to -filter out the startup phase of the program, which is often very different. +After starting the program, wait msecs before measuring (-1: start with events +disabled). This is useful to filter out the startup phase of the program, +which is often very different. -T:: --transaction:: diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c index a5a0f4841003..9d5c503e698f 100644 --- a/tools/perf/builtin-stat.c +++ b/tools/perf/builtin-stat.c @@ -487,16 +487,26 @@ static bool handle_interval(unsigned int interval, int *times) static void enable_counters(void) { - if (stat_config.initial_delay) + if (stat_config.initial_delay < 0) { + pr_info(EVLIST_DISABLED_MSG); + return; + } + + if (stat_config.initial_delay > 0) { + pr_info(EVLIST_DISABLED_MSG); usleep(stat_config.initial_delay * USEC_PER_MSEC); + } /* * We need to enable counters only if: * - we don't have tracee (attaching to task or cpu) * - we have initial delay configured */ - if (!target__none(&target) || stat_config.initial_delay) + if (!target__none(&target) || stat_config.initial_delay) { evlist__enable(evsel_list); + if (stat_config.initial_delay > 0) + pr_info(EVLIST_ENABLED_MSG); + } } static void disable_counters(void) @@ -1053,8 +1063,8 @@ static struct option stat_options[] = { "aggregate counts per thread", AGGR_THREAD), OPT_SET_UINT(0, "per-node", &stat_config.aggr_mode, "aggregate counts per numa node", AGGR_NODE), - OPT_UINTEGER('D', "delay", &stat_config.initial_delay, - "ms to wait before starting measurement after program start"), + OPT_INTEGER('D', "delay", &stat_config.initial_delay, + "ms to wait before starting measurement after program start (-1: start with events disabled)"), OPT_CALLBACK_NOOPT(0, "metric-only", &stat_config.metric_only, NULL, "Only print computed metrics. No raw values", enable_metric_only), OPT_BOOLEAN(0, "metric-no-group", &stat_config.metric_no_group, diff --git a/tools/perf/util/evlist.h b/tools/perf/util/evlist.h index ec676accc76b..c73f7f7f120b 100644 --- a/tools/perf/util/evlist.h +++ b/tools/perf/util/evlist.h @@ -378,4 +378,7 @@ int evlist__finalize_ctlfd(struct evlist *evlist); bool evlist__ctlfd_initialized(struct evlist *evlist); int evlist__ctlfd_process(struct evlist *evlist, enum evlist_ctl_cmd *cmd); +#define EVLIST_ENABLED_MSG "Events enabled\n" +#define EVLIST_DISABLED_MSG "Events disabled\n" + #endif /* __PERF_EVLIST_H */ diff --git a/tools/perf/util/stat.h b/tools/perf/util/stat.h index 6911c7249199..41d59f192931 100644 --- a/tools/perf/util/stat.h +++ b/tools/perf/util/stat.h @@ -116,7 +116,7 @@ struct perf_stat_config { FILE *output; unsigned int interval; unsigned int timeout; - unsigned int initial_delay; + int initial_delay; unsigned int unit_width; unsigned int metric_only_len; int times;