[RFC PATCH v1 37/37] perf test/evlist-open-close: add detailed output mode

[Riccardo Mancini <rickyman7@gmail.com>]

This patch adds a detailed output mode in the perf-test
evlist-open-close. In this output mode, the time taken by each single
evlist function is computed.

Normal mode:
$ sudo ./perf bench internals evlist-open-close
  Number of workers:    1
  Number of cpus:       4
  Number of threads:    1
  Number of events:     1 (4 fds)
  Number of iterations: 100
  Average open-close took:     1199.300 usec (+-      289.699 usec)

Detailed mode:
$ sudo ./perf bench internals evlist-open-close -d
  Number of workers:    1
  Number of cpus:       4
  Number of threads:    1
  Number of events:     1 (4 fds)
  Number of iterations: 100
  Average open-close took:     1199.300 usec (+-      289.699 usec)
                init took:        0.000 usec (+-        0.000 usec)
                open took:       25.600 usec (+-        1.778 usec)
                mmap took:      532.000 usec (+-       58.133 usec)
              enable took:      337.300 usec (+-      194.160 usec)
             disable took:      181.700 usec (+-       85.307 usec)
              munmap took:       22.100 usec (+-        4.045 usec)
               close took:      100.300 usec (+-       21.329 usec)
                fini took:        0.200 usec (+-        0.133 usec)

* init and fini represent the time taken before and after the evlist
  operations (in this case the workqueue setup and teardown operations)

Signed-off-by: Riccardo Mancini <rickyman7@gmail.com>
---
 tools/perf/bench/evlist-open-close.c | 63 ++++++++++++++++++++++++++--
 1 file changed, 60 insertions(+), 3 deletions(-)

diff --git a/tools/perf/bench/evlist-open-close.c b/tools/perf/bench/evlist-open-close.c
index 00d0aef564f80d44..8ba2799c66cafb3e 100644
--- a/tools/perf/bench/evlist-open-close.c
+++ b/tools/perf/bench/evlist-open-close.c
@@ -25,12 +25,18 @@
 static int iterations = 100;
 static int nr_events = 1;
 static const char *event_string = "dummy";
+static bool detail;
 
 static inline u64 timeval2usec(struct timeval *tv)
 {
 	return tv->tv_sec * USEC_PER_SEC + tv->tv_usec;
 }
 
+struct timers {
+	struct timeval start, end, diff;
+	struct stats init, open, mmap, enable, disable, munmap, close, fini;
+};
+
 static struct record_opts opts = {
 	.sample_time	     = true,
 	.mmap_pages	     = UINT_MAX,
@@ -60,6 +66,7 @@ static const struct option options[] = {
 	OPT_STRING('u', "uid", &opts.target.uid_str, "user", "user to profile"),
 	OPT_BOOLEAN(0, "per-thread", &opts.target.per_thread, "use per-thread mmaps"),
 	OPT_UINTEGER_OPTARG('j', "threads", &opts.nr_threads, UINT_MAX, "Number of threads to use"),
+	OPT_BOOLEAN('d', "detail", &detail, "compute time taken by single functions"),
 	OPT_END()
 };
 
@@ -113,11 +120,28 @@ static struct evlist *bench__create_evlist(char *evstr)
 	return NULL;
 }
 
-static int bench__do_evlist_open_close(struct evlist *evlist)
+#define START_TIMER(timers) do { \
+	if (detail) { \
+		gettimeofday(&(timers)->start, NULL); \
+	} \
+} while (0)
+
+#define RECORD_TIMER(timers, field) do { \
+	if (detail) { \
+		gettimeofday(&(timers)->end, NULL); \
+		timersub(&(timers)->end, &(timers)->start, &(timers)->diff); \
+		update_stats(&(timers)->field, timeval2usec(&(timers)->diff)); \
+		(timers)->start = (timers)->end; \
+	} \
+} while (0)
+
+static int bench__do_evlist_open_close(struct evlist *evlist, struct timers *timers)
 {
 	char sbuf[WORKQUEUE_STRERR_BUFSIZE];
 	int err = -1, ret;
 
+	START_TIMER(timers);
+
 	if (opts.nr_threads > 1) {
 		err = setup_global_workqueue(opts.nr_threads);
 		if (err) {
@@ -130,23 +154,30 @@ static int bench__do_evlist_open_close(struct evlist *evlist)
 
 		perf_set_multithreaded();
 	}
+	RECORD_TIMER(timers, init);
 
 	err = evlist__open(evlist);
 	if (err < 0) {
 		pr_err("evlist__open: %s\n", str_error_r(errno, sbuf, sizeof(sbuf)));
 		goto out;
 	}
+	RECORD_TIMER(timers, open);
 
 	err = evlist__mmap(evlist, opts.mmap_pages);
 	if (err < 0) {
 		pr_err("evlist__mmap: %s\n", str_error_r(errno, sbuf, sizeof(sbuf)));
 		goto out;
 	}
+	RECORD_TIMER(timers, mmap);
 
 	evlist__enable(evlist);
+	RECORD_TIMER(timers, enable);
 	evlist__disable(evlist);
+	RECORD_TIMER(timers, disable);
 	evlist__munmap(evlist);
+	RECORD_TIMER(timers, munmap);
 	evlist__close(evlist);
+	RECORD_TIMER(timers, close);
 
 out:
 	if (opts.nr_threads > 1) {
@@ -159,10 +190,15 @@ static int bench__do_evlist_open_close(struct evlist *evlist)
 
 		perf_set_singlethreaded();
 	}
+	RECORD_TIMER(timers, fini);
 
 	return err;
 }
 
+#define PRINT_TIMER(timers, field) \
+	printf("%20s took: %12.3f usec (+- %12.3f usec)\n", #field, \
+		avg_stats(&(timers)->field), stddev_stats(&(timers)->field))
+
 static int bench_evlist_open_close__run(char *evstr)
 {
 	// used to print statistics only
@@ -172,10 +208,21 @@ static int bench_evlist_open_close__run(char *evstr)
 	struct stats time_stats;
 	u64 runtime_us;
 	int i, err;
+	struct timers timers;
 
 	if (!evlist)
 		return -ENOMEM;
 
+	init_stats(&time_stats);
+	init_stats(&timers.init);
+	init_stats(&timers.open);
+	init_stats(&timers.mmap);
+	init_stats(&timers.enable);
+	init_stats(&timers.disable);
+	init_stats(&timers.munmap);
+	init_stats(&timers.close);
+	init_stats(&timers.fini);
+
 	init_stats(&time_stats);
 
 	printf("  Number of workers:\t%u\n", opts.nr_threads);
@@ -194,7 +241,7 @@ static int bench_evlist_open_close__run(char *evstr)
 			return -ENOMEM;
 
 		gettimeofday(&start, NULL);
-		err = bench__do_evlist_open_close(evlist);
+		err = bench__do_evlist_open_close(evlist, &timers);
 		if (err) {
 			evlist__delete(evlist);
 			return err;
@@ -211,7 +258,17 @@ static int bench_evlist_open_close__run(char *evstr)
 
 	time_average = avg_stats(&time_stats);
 	time_stddev = stddev_stats(&time_stats);
-	printf("  Average open-close took: %.3f usec (+- %.3f usec)\n", time_average, time_stddev);
+	printf("  Average open-close took: %12.3f usec (+- %12.3f usec)\n", time_average, time_stddev);
+	if (detail) {
+		PRINT_TIMER(&timers, init);
+		PRINT_TIMER(&timers, open);
+		PRINT_TIMER(&timers, mmap);
+		PRINT_TIMER(&timers, enable);
+		PRINT_TIMER(&timers, disable);
+		PRINT_TIMER(&timers, munmap);
+		PRINT_TIMER(&timers, close);
+		PRINT_TIMER(&timers, fini);
+	}
 
 	return 0;
 }
-- 
2.31.1