Re: [PATCH v5 1/3] perf bench: add a multi-threaded synthesize benchmark

From: Arnaldo Carvalho de Melo
Date: Thu Apr 23 2020 - 10:17:56 EST

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Em Tue, Apr 14, 2020 at 10:40:48PM -0700, Ian Rogers escreveu:
> By default this isn't run as it reads /proc and may not have access.
> For consistency, modify the single threaded benchmark to compute an
> average time per event.

Thanks, applied,

- Arnaldo

> Signed-off-by: Ian Rogers <irogers@xxxxxxxxxx>
> ---
> tools/perf/bench/synthesize.c | 211 ++++++++++++++++++++++++++++++----
> 1 file changed, 186 insertions(+), 25 deletions(-)
>
> diff --git a/tools/perf/bench/synthesize.c b/tools/perf/bench/synthesize.c
> index 6291257bc9c9..8d624aea1c5e 100644
> --- a/tools/perf/bench/synthesize.c
> +++ b/tools/perf/bench/synthesize.c
> @@ -10,60 +10,105 @@
> #include "bench.h"
> #include "../util/debug.h"
> #include "../util/session.h"
> +#include "../util/stat.h"
> #include "../util/synthetic-events.h"
> #include "../util/target.h"
> #include "../util/thread_map.h"
> #include "../util/tool.h"
> +#include "../util/util.h"
> +#include <linux/atomic.h>
> #include <linux/err.h>
> #include <linux/time64.h>
> #include <subcmd/parse-options.h>
>
> -static unsigned int iterations = 10000;
> +static unsigned int min_threads = 1;
> +static unsigned int max_threads = UINT_MAX;
> +static unsigned int single_iterations = 10000;
> +static unsigned int multi_iterations = 10;
> +static bool run_st;
> +static bool run_mt;
>
> static const struct option options[] = {
> - OPT_UINTEGER('i', "iterations", &iterations,
> - "Number of iterations used to compute average"),
> + OPT_BOOLEAN('s', "st", &run_st, "Run single threaded benchmark"),
> + OPT_BOOLEAN('t', "mt", &run_mt, "Run multi-threaded benchmark"),
> + OPT_UINTEGER('m', "min-threads", &min_threads,
> + "Minimum number of threads in multithreaded bench"),
> + OPT_UINTEGER('M', "max-threads", &max_threads,
> + "Maximum number of threads in multithreaded bench"),
> + OPT_UINTEGER('i', "single-iterations", &single_iterations,
> + "Number of iterations used to compute single-threaded average"),
> + OPT_UINTEGER('I', "multi-iterations", &multi_iterations,
> + "Number of iterations used to compute multi-threaded average"),
> OPT_END()
> };
>
> -static const char *const usage[] = {
> +static const char *const bench_usage[] = {
> "perf bench internals synthesize <options>",
> NULL
> };
>
> +static atomic_t event_count;
>
> -static int do_synthesize(struct perf_session *session,
> - struct perf_thread_map *threads,
> - struct target *target, bool data_mmap)
> +static int process_synthesized_event(struct perf_tool *tool __maybe_unused,
> + union perf_event *event __maybe_unused,
> + struct perf_sample *sample __maybe_unused,
> + struct machine *machine __maybe_unused)
> +{
> + atomic_inc(&event_count);
> + return 0;
> +}
> +
> +static int do_run_single_threaded(struct perf_session *session,
> + struct perf_thread_map *threads,
> + struct target *target, bool data_mmap)
> {
> const unsigned int nr_threads_synthesize = 1;
> struct timeval start, end, diff;
> u64 runtime_us;
> unsigned int i;
> - double average;
> + double time_average, time_stddev, event_average, event_stddev;
> int err;
> + struct stats time_stats, event_stats;
>
> - gettimeofday(&start, NULL);
> - for (i = 0; i < iterations; i++) {
> - err = machine__synthesize_threads(&session->machines.host,
> - target, threads, data_mmap,
> + init_stats(&time_stats);
> + init_stats(&event_stats);
> +
> + for (i = 0; i < single_iterations; i++) {
> + atomic_set(&event_count, 0);
> + gettimeofday(&start, NULL);
> + err = __machine__synthesize_threads(&session->machines.host,
> + NULL,
> + target, threads,
> + process_synthesized_event,
> + data_mmap,
> nr_threads_synthesize);
> if (err)
> return err;
> +
> + gettimeofday(&end, NULL);
> + timersub(&end, &start, &diff);
> + runtime_us = diff.tv_sec * USEC_PER_SEC + diff.tv_usec;
> + update_stats(&time_stats, runtime_us);
> + update_stats(&event_stats, atomic_read(&event_count));
> }
>
> - gettimeofday(&end, NULL);
> - timersub(&end, &start, &diff);
> - runtime_us = diff.tv_sec * USEC_PER_SEC + diff.tv_usec;
> - average = (double)runtime_us/(double)iterations;
> - printf("Average %ssynthesis took: %f usec\n",
> - data_mmap ? "data " : "", average);
> + time_average = avg_stats(&time_stats);
> + time_stddev = stddev_stats(&time_stats);
> + printf(" Average %ssynthesis took: %.3f usec (+- %.3f usec)\n",
> + data_mmap ? "data " : "", time_average, time_stddev);
> +
> + event_average = avg_stats(&event_stats);
> + event_stddev = stddev_stats(&event_stats);
> + printf(" Average num. events: %.3f (+- %.3f)\n",
> + event_average, event_stddev);
> +
> + printf(" Average time per event %.3f usec\n",
> + time_average / event_average);
> return 0;
> }
>
> -int bench_synthesize(int argc, const char **argv)
> +static int run_single_threaded(void)
> {
> - struct perf_tool tool;
> struct perf_session *session;
> struct target target = {
> .pid = "self",
> @@ -71,8 +116,7 @@ int bench_synthesize(int argc, const char **argv)
> struct perf_thread_map *threads;
> int err;
>
> - argc = parse_options(argc, argv, options, usage, 0);
> -
> + perf_set_singlethreaded();
> session = perf_session__new(NULL, false, NULL);
> if (IS_ERR(session)) {
> pr_err("Session creation failed.\n");
> @@ -84,13 +128,16 @@ int bench_synthesize(int argc, const char **argv)
> err = -ENOMEM;
> goto err_out;
> }
> - perf_tool__fill_defaults(&tool);
>
> - err = do_synthesize(session, threads, &target, false);
> + puts(
> +"Computing performance of single threaded perf event synthesis by\n"
> +"synthesizing events on the perf process itself:");
> +
> + err = do_run_single_threaded(session, threads, &target, false);
> if (err)
> goto err_out;
>
> - err = do_synthesize(session, threads, &target, true);
> + err = do_run_single_threaded(session, threads, &target, true);
>
> err_out:
> if (threads)
> @@ -99,3 +146,117 @@ int bench_synthesize(int argc, const char **argv)
> perf_session__delete(session);
> return err;
> }
> +
> +static int do_run_multi_threaded(struct target *target,
> + unsigned int nr_threads_synthesize)
> +{
> + struct timeval start, end, diff;
> + u64 runtime_us;
> + unsigned int i;
> + double time_average, time_stddev, event_average, event_stddev;
> + int err;
> + struct stats time_stats, event_stats;
> + struct perf_session *session;
> +
> + init_stats(&time_stats);
> + init_stats(&event_stats);
> + for (i = 0; i < multi_iterations; i++) {
> + session = perf_session__new(NULL, false, NULL);
> + if (!session)
> + return -ENOMEM;
> +
> + atomic_set(&event_count, 0);
> + gettimeofday(&start, NULL);
> + err = __machine__synthesize_threads(&session->machines.host,
> + NULL,
> + target, NULL,
> + process_synthesized_event,
> + false,
> + nr_threads_synthesize);
> + if (err) {
> + perf_session__delete(session);
> + return err;
> + }
> +
> + gettimeofday(&end, NULL);
> + timersub(&end, &start, &diff);
> + runtime_us = diff.tv_sec * USEC_PER_SEC + diff.tv_usec;
> + update_stats(&time_stats, runtime_us);
> + update_stats(&event_stats, atomic_read(&event_count));
> + perf_session__delete(session);
> + }
> +
> + time_average = avg_stats(&time_stats);
> + time_stddev = stddev_stats(&time_stats);
> + printf(" Average synthesis took: %.3f usec (+- %.3f usec)\n",
> + time_average, time_stddev);
> +
> + event_average = avg_stats(&event_stats);
> + event_stddev = stddev_stats(&event_stats);
> + printf(" Average num. events: %.3f (+- %.3f)\n",
> + event_average, event_stddev);
> +
> + printf(" Average time per event %.3f usec\n",
> + time_average / event_average);
> + return 0;
> +}
> +
> +static int run_multi_threaded(void)
> +{
> + struct target target = {
> + .cpu_list = "0"
> + };
> + unsigned int nr_threads_synthesize;
> + int err;
> +
> + if (max_threads == UINT_MAX)
> + max_threads = sysconf(_SC_NPROCESSORS_ONLN);
> +
> + puts(
> +"Computing performance of multi threaded perf event synthesis by\n"
> +"synthesizing events on CPU 0:");
> +
> + for (nr_threads_synthesize = min_threads;
> + nr_threads_synthesize <= max_threads;
> + nr_threads_synthesize++) {
> + if (nr_threads_synthesize == 1)
> + perf_set_singlethreaded();
> + else
> + perf_set_multithreaded();
> +
> + printf(" Number of synthesis threads: %u\n",
> + nr_threads_synthesize);
> +
> + err = do_run_multi_threaded(&target, nr_threads_synthesize);
> + if (err)
> + return err;
> + }
> + perf_set_singlethreaded();
> + return 0;
> +}
> +
> +int bench_synthesize(int argc, const char **argv)
> +{
> + int err = 0;
> +
> + argc = parse_options(argc, argv, options, bench_usage, 0);
> + if (argc) {
> + usage_with_options(bench_usage, options);
> + exit(EXIT_FAILURE);
> + }
> +
> + /*
> + * If neither single threaded or multi-threaded are specified, default
> + * to running just single threaded.
> + */
> + if (!run_st && !run_mt)
> + run_st = true;
> +
> + if (run_st)
> + err = run_single_threaded();
> +
> + if (!err && run_mt)
> + err = run_multi_threaded();
> +
> + return err;
> +}
> --
> 2.26.0.110.g2183baf09c-goog
>

--

- Arnaldo

Next message: Colin King: "[PATCH][next] drm/amd/display: remove redundant assignment to variable ret"
Previous message: Ian Rogers: "Re: [PATCH v2 10/11] perf expr: print a debug message for division by zero"
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