Re: [PATCH v3 4/4] perf stat: Report summary for interval mode

[Jiri Olsa <jolsa@redhat.com>]

On Thu, May 07, 2020 at 02:58:22PM +0800, Jin Yao wrote:
> Currently perf-stat supports to print counts at regular interval (-I),
> but it's not very easy for user to get the overall statistics.
> 
> The patch uses 'evsel->prev_raw_counts' to get counts for summary.
> Copy the counts to 'evsel->counts' after printing the interval results.
> Next, we just follow the non-interval processing.
> 
> Let's see some examples,
> 
>  root@kbl-ppc:~# perf stat -e cycles -I1000 --interval-count 2
>  #           time             counts unit events
>       1.000412064          2,281,114      cycles
>       2.001383658          2,547,880      cycles
> 
>   Performance counter stats for 'system wide':
> 
>           4,828,994      cycles
> 
>         2.002860349 seconds time elapsed
> 
>  root@kbl-ppc:~# perf stat -e cycles,instructions -I1000 --interval-count 2
>  #           time             counts unit events
>       1.000389902          1,536,093      cycles
>       1.000389902            420,226      instructions              #    0.27  insn per cycle
>       2.001433453          2,213,952      cycles
>       2.001433453            735,465      instructions              #    0.33  insn per cycle
> 
>   Performance counter stats for 'system wide':
> 
>           3,750,045      cycles
>           1,155,691      instructions              #    0.31  insn per cycle
> 
>         2.003023361 seconds time elapsed
> 
>  root@kbl-ppc:~# perf stat -M CPI,IPC -I1000 --interval-count 2
>  #           time             counts unit events
>       1.000435121            905,303      inst_retired.any          #      2.9 CPI
>       1.000435121          2,663,333      cycles
>       1.000435121            914,702      inst_retired.any          #      0.3 IPC
>       1.000435121          2,676,559      cpu_clk_unhalted.thread
>       2.001615941          1,951,092      inst_retired.any          #      1.8 CPI
>       2.001615941          3,551,357      cycles
>       2.001615941          1,950,837      inst_retired.any          #      0.5 IPC
>       2.001615941          3,551,044      cpu_clk_unhalted.thread
> 
>   Performance counter stats for 'system wide':
> 
>           2,856,395      inst_retired.any          #      2.2 CPI
>           6,214,690      cycles
>           2,865,539      inst_retired.any          #      0.5 IPC
>           6,227,603      cpu_clk_unhalted.thread
> 
>         2.003403078 seconds time elapsed
> 
>  v3:
>  ---
>  Use evsel->prev_raw_counts for summary counts
> 
>  v2:
>  ---
>  Rebase to perf/core branch
> 
> Signed-off-by: Jin Yao <yao.jin@linux.intel.com>
> ---
>  tools/perf/builtin-stat.c | 16 ++++++++++++++--
>  tools/perf/util/stat.c    |  2 +-
>  tools/perf/util/stat.h    |  1 +
>  3 files changed, 16 insertions(+), 3 deletions(-)
> 
> diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c
> index 97ee941649e6..f67d6a50274e 100644
> --- a/tools/perf/builtin-stat.c
> +++ b/tools/perf/builtin-stat.c
> @@ -334,7 +334,7 @@ static void read_counters(struct timespec *rs)
>  		evlist__for_each_entry(evsel_list, counter) {
>  			if (evsel__cpu_iter_skip(counter, cpu))
>  				continue;
> -			if (!counter->err) {
> +			if (!counter->err && !stat_config.summary) {

you'll go through all the affinity setup and do nothing at the end,
even if you know at the begining that it's the case.. not good

we need to call only the perf_stat_process_counter in summary case

jirka

>  				counter->err = read_counter_cpu(counter, rs,
>  								counter->cpu_iter - 1);
>  			}
> @@ -364,6 +364,7 @@ static void thread_stats_reset(struct perf_stat_config *config)
>  static void process_interval(void)
>  {
>  	struct timespec ts, rs;
> +	struct stats walltime_nsecs_stats_bak;
>  
>  	clock_gettime(CLOCK_MONOTONIC, &ts);
>  	diff_timespec(&rs, &ts, &ref_time);
> @@ -377,9 +378,11 @@ static void process_interval(void)
>  			pr_err("failed to write stat round event\n");
>  	}
>  
> +	walltime_nsecs_stats_bak = walltime_nsecs_stats;
>  	init_stats(&walltime_nsecs_stats);
>  	update_stats(&walltime_nsecs_stats, stat_config.interval * 1000000);
>  	print_counters(&rs, 0, NULL);
> +	walltime_nsecs_stats = walltime_nsecs_stats_bak;
>  }
>  
>  static void enable_counters(void)
> @@ -735,6 +738,15 @@ static int __run_perf_stat(int argc, const char **argv, int run_idx)
>  
>  	update_stats(&walltime_nsecs_stats, t1 - t0);
>  
> +	if (interval) {
> +		stat_config.interval = 0;
> +		stat_config.summary = true;
> +		perf_evlist__copy_prev_raw_counts(evsel_list);
> +		perf_evlist__reset_prev_raw_counts(evsel_list);
> +		thread_stats_reset(&stat_config);
> +		perf_stat__reset_shadow_per_stat(&rt_stat);
> +	}
> +
>  	/*
>  	 * Closing a group leader splits the group, and as we only disable
>  	 * group leaders, results in remaining events becoming enabled. To
> @@ -2158,7 +2170,7 @@ int cmd_stat(int argc, const char **argv)
>  		}
>  	}
>  
> -	if (!forever && status != -1 && !interval)
> +	if (!forever && status != -1 && (!interval || stat_config.summary))
>  		print_counters(NULL, argc, argv);
>  
>  	if (STAT_RECORD) {
> diff --git a/tools/perf/util/stat.c b/tools/perf/util/stat.c
> index ede113805ecd..47b26c024830 100644
> --- a/tools/perf/util/stat.c
> +++ b/tools/perf/util/stat.c
> @@ -393,7 +393,7 @@ int perf_stat_process_counter(struct perf_stat_config *config,
>  	 * interval mode, otherwise overall avg running
>  	 * averages will be shown for each interval.
>  	 */
> -	if (config->interval) {
> +	if (config->interval || config->summary) {
>  		for (i = 0; i < 3; i++)
>  			init_stats(&ps->res_stats[i]);
>  	}
> diff --git a/tools/perf/util/stat.h b/tools/perf/util/stat.h
> index 62cf72c71869..c60e9e5d6474 100644
> --- a/tools/perf/util/stat.h
> +++ b/tools/perf/util/stat.h
> @@ -110,6 +110,7 @@ struct perf_stat_config {
>  	bool			 all_kernel;
>  	bool			 all_user;
>  	bool			 percore_show_thread;
> +	bool			 summary;
>  	FILE			*output;
>  	unsigned int		 interval;
>  	unsigned int		 timeout;
> -- 
> 2.17.1
>