Commit 25f69c69 authored by Changbin Du's avatar Changbin Du Committed by Arnaldo Carvalho de Melo
Browse files

perf stat: Fix counting when initial delay configured 



When creating counters with initial delay configured, the enable_on_exec
field is not set. So we need to enable the counters later. The problem
is, when a workload is specified the target__none() is true. So we also
need to check stat_config.initial_delay.

In this change, we add a new field 'initial_delay' for struct target
which could be shared by other subcommands. And define
target__enable_on_exec() which returns whether enable_on_exec should be
set on normal cases.

Before this fix the event is not counted:

  $ ./perf stat -e instructions -D 100 sleep 2
  Events disabled
  Events enabled

   Performance counter stats for 'sleep 2':

       <not counted>      instructions

         1.901661124 seconds time elapsed

         0.001602000 seconds user
         0.000000000 seconds sys

After fix it works:

  $ ./perf stat -e instructions -D 100 sleep 2
  Events disabled
  Events enabled

   Performance counter stats for 'sleep 2':

             404,214      instructions

         1.901743475 seconds time elapsed

         0.001617000 seconds user
         0.000000000 seconds sys

Fixes: c587e77e ("perf stat: Do not delay the workload with --delay")
Signed-off-by: default avatarChangbin Du <changbin.du@huawei.com>
Acked-by: default avatarNamhyung Kim <namhyung@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Hui Wang <hw.huiwang@huawei.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20230302031146.2801588-2-changbin.du@huawei.com


Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent a98c0710

tools/perf/builtin-stat.c

+5 −10
Original line number Diff line number Diff line
@@ -539,12 +539,7 @@ static int enable_counters(void) 
			return err;

	}



	/*

	 * 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)) {

	if (!target__enable_on_exec(&target)) {

		if (!all_counters_use_bpf)

			evlist__enable(evsel_list);

	}
@@ -914,7 +909,7 @@ static int __run_perf_stat(int argc, const char **argv, int run_idx) 
			return err;

	}



	if (stat_config.initial_delay) {

	if (target.initial_delay) {

		pr_info(EVLIST_DISABLED_MSG);

	} else {

		err = enable_counters();
@@ -926,8 +921,8 @@ static int __run_perf_stat(int argc, const char **argv, int run_idx) 
	if (forks)

		evlist__start_workload(evsel_list);



	if (stat_config.initial_delay > 0) {

		usleep(stat_config.initial_delay * USEC_PER_MSEC);

	if (target.initial_delay > 0) {

		usleep(target.initial_delay * USEC_PER_MSEC);

		err = enable_counters();

		if (err)

			return -1;
@@ -1248,7 +1243,7 @@ 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_INTEGER('D', "delay", &stat_config.initial_delay,

	OPT_INTEGER('D', "delay", &target.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),

tools/perf/util/stat.c

+1 −5
Original line number Diff line number Diff line
@@ -842,11 +842,7 @@ int create_perf_stat_counter(struct evsel *evsel, 
	if (evsel__is_group_leader(evsel)) {

		attr->disabled = 1;



		/*

		 * In case of initial_delay we enable tracee

		 * events manually.

		 */

		if (target__none(target) && !config->initial_delay)

		if (target__enable_on_exec(target))

			attr->enable_on_exec = 1;

	}

tools/perf/util/stat.h

+0 −1
Original line number Diff line number Diff line
@@ -166,7 +166,6 @@ struct perf_stat_config { 
	FILE			*output;

	unsigned int		 interval;

	unsigned int		 timeout;

	int			 initial_delay;

	unsigned int		 unit_width;

	unsigned int		 metric_only_len;

	int			 times;

tools/perf/util/target.h

+12 −0
Original line number Diff line number Diff line
@@ -18,6 +18,7 @@ struct target { 
	bool	     per_thread;

	bool	     use_bpf;

	bool	     hybrid;

	int	     initial_delay;

	const char   *attr_map;

};
@@ -72,6 +73,17 @@ static inline bool target__none(struct target *target) 
	return !target__has_task(target) && !target__has_cpu(target);

}



static inline bool target__enable_on_exec(struct target *target)

{

	/*

	 * Normally enable_on_exec should be set if:

	 *  1) The tracee process is forked (not attaching to existed task or cpu).

	 *  2) And initial_delay is not configured.

	 * Otherwise, we enable tracee events manually.

	 */

	return target__none(target) && !target->initial_delay;

}



static inline bool target__has_per_thread(struct target *target)

{

	return target->system_wide && target->per_thread;