[PATCH 09/91] perf bench: Add a multi-threaded synthesize benchmark

Arnaldo Carvalho de Melo
2020-05-06T15:23:22Z

From: Ian Rogers <irogers@google.com>

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.

Committer testing:

$ grep -m1 "model name" /proc/cpuinfo
model name : Intel(R) Core(TM) i7-8650U CPU @ 1.90GHz
$ grep "model name" /proc/cpuinfo | wc -l
8
$
$ perf bench internals synthesize -h
# Running 'internals/synthesize' benchmark:

Usage: perf bench internals synthesize <options>

-I, --multi-iterations <n>
Number of iterations used to compute multi-threaded average
-i, --single-iterations <n>
Number of iterations used to compute single-threaded average
-M, --max-threads <n>
Maximum number of threads in multithreaded bench
-m, --min-threads <n>
Minimum number of threads in multithreaded bench
-s, --st Run single threaded benchmark
-t, --mt Run multi-threaded benchmark

$
$ perf bench internals synthesize -t
# Running 'internals/synthesize' benchmark:
Computing performance of multi threaded perf event synthesis by
synthesizing events on CPU 0:
Number of synthesis threads: 1
Average synthesis took: 65449.000 usec (+- 586.442 usec)
Average num. events: 9405.400 (+- 0.306)
Average time per event 6.959 usec
Number of synthesis threads: 2
Average synthesis took: 37838.300 usec (+- 130.259 usec)
Average num. events: 9501.800 (+- 20.469)
Average time per event 3.982 usec
Number of synthesis threads: 3
Average synthesis took: 48551.400 usec (+- 225.686 usec)
Average num. events: 9544.000 (+- 0.000)
Average time per event 5.087 usec
Number of synthesis threads: 4
Average synthesis took: 29632.500 usec (+- 50.808 usec)
Average num. events: 9544.000 (+- 0.000)
Average time per event 3.105 usec
Number of synthesis threads: 5
Average synthesis took: 33920.400 usec (+- 284.509 usec)
Average num. events: 9544.000 (+- 0.000)
Average time per event 3.554 usec
Number of synthesis threads: 6
Average synthesis took: 27604.100 usec (+- 72.344 usec)
Average num. events: 9548.000 (+- 0.000)
Average time per event 2.891 usec
Number of synthesis threads: 7
Average synthesis took: 25406.300 usec (+- 933.371 usec)
Average num. events: 9545.500 (+- 0.167)
Average time per event 2.662 usec
Number of synthesis threads: 8
Average synthesis took: 24110.400 usec (+- 73.229 usec)
Average num. events: 9551.000 (+- 0.000)
Average time per event 2.524 usec
$

Signed-off-by: Ian Rogers <irogers@google.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andrey Zhizhikin <andrey.z@gmail.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lore.kernel.org/lkml/20200415054050.31645-2-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
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;
+}
--
2.21.1