Re: [PATCH v2 04/11] perf stat: extend -D,--delay option with -1 value

Arnaldo Carvalho de Melo
2020-05-06T20:12:34Z

Em Wed, May 06, 2020 at 09:20:54PM +0300, Alexey Budankov escreveu:
>
> Extend -D,--delay option with -1 value to start monitoring with
> events disabled to be enabled later by enable command provided
> via control file descriptor.

> Signed-off-by: Alexey Budankov <alexey.budankov@linux.intel.com>
> ---
> tools/perf/builtin-stat.c | 18 ++++++++++++++----
> tools/perf/util/evlist.h | 3 +++
> tools/perf/util/stat.h | 2 +-

You forgot to update tools/perf/Documentation/perf-stat.h

> 3 files changed, 18 insertions(+), 5 deletions(-)
>
> diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c
> index 9775b0905146..bda777ca0420 100644
> --- a/tools/perf/builtin-stat.c
> +++ b/tools/perf/builtin-stat.c
> @@ -383,16 +383,26 @@ static bool print_interval_and_stop(struct perf_stat_config *config, int *times)
>
> static void enable_counters(void)
> {
> - if (stat_config.initial_delay)
> + if (stat_config.initial_delay < 0) {
> + pr_info(PERF_EVLIST__DISABLED_MSG);
> + return;
> + }
> +
> + if (stat_config.initial_delay > 0) {
> + pr_info(PERF_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(PERF_EVLIST__ENABLED_MSG);
> + }
> }
>
> static void disable_counters(void)
> @@ -929,8 +939,8 @@ 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, "topdown", &topdown_run,
> diff --git a/tools/perf/util/evlist.h b/tools/perf/util/evlist.h
> index 84386850c290..874ecf068ac9 100644
> --- a/tools/perf/util/evlist.h
> +++ b/tools/perf/util/evlist.h
> @@ -366,6 +366,9 @@ enum evlist_ctl_cmd {
> CTL_CMD_ACK = 'a'
> };
>
> +#define PERF_EVLIST__ENABLED_MSG "Events enabled\n"
> +#define PERF_EVLIST__DISABLED_MSG "Events disabled\n"
> +
> int perf_evlist__initialize_ctlfd(struct evlist *evlist, int ctl_fd, int ctl_fd_ack);
> int perf_evlist__finalize_ctlfd(struct evlist *evlist);
> int perf_evlist__ctlfd_process(struct evlist *evlist, enum evlist_ctl_cmd *cmd);
> diff --git a/tools/perf/util/stat.h b/tools/perf/util/stat.h
> index b4fdfaa7f2c0..027b9dcd902f 100644
> --- a/tools/perf/util/stat.h
> +++ b/tools/perf/util/stat.h
> @@ -113,7 +113,7 @@ 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;
> --
> 2.24.1
>
>

--

- Arnaldo