[PATCH 2/2] perf stat: Report summary for interval mode

Jin Yao
2020-04-30T03:09:50Z

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->summary_counts' to sum up the per interval counts
and 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

Signed-off-by: Jin Yao <yao.jin@linux.intel.com>
---
tools/perf/builtin-stat.c | 14 ++++++++--
tools/perf/util/stat.c | 57 +++++++++++++++++++++++++++++++++++++++
tools/perf/util/stat.h | 5 ++++
3 files changed, 74 insertions(+), 2 deletions(-)

diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c
index 3f050d85c277..338bd35e9901 100644
--- a/tools/perf/builtin-stat.c
+++ b/tools/perf/builtin-stat.c
@@ -355,6 +355,7 @@ static void read_counters(struct timespec *rs)
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);
@@ -367,9 +368,11 @@ 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)
@@ -732,7 +735,14 @@ static int __run_perf_stat(int argc, const char **argv, int run_idx)
* avoid arbitrary skew, we must read all counters before closing any
* group leaders.
*/
- read_counters(&(struct timespec) { .tv_nsec = t1-t0 });
+ if (!interval)
+ read_counters(&(struct timespec) { .tv_nsec = t1-t0 });
+ else {
+ stat_config.interval = 0;
+ stat_config.summary = true;
+ perf_evlist__copy_summary_counts(evsel_list);
+ perf_evlist__process_summary_counts(&stat_config, evsel_list);
+ }

/*
* We need to keep evsel_list alive, because it's processed
@@ -2149,7 +2159,7 @@ 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 cf09cd7675c2..a247ea9ea669 100644
--- a/tools/perf/util/stat.c
+++ b/tools/perf/util/stat.c
@@ -249,6 +249,63 @@ void perf_evlist__reset_prev_raw_counts(struct evlist *evlist)
perf_evsel__reset_prev_raw_counts(evsel);
}

+static void perf_evsel__copy_summary_counts(struct evsel *evsel)
+{
+ int ncpus = perf_evsel__nr_cpus(evsel);
+ int nthreads = perf_thread_map__nr(evsel->core.threads);
+
+ for (int thread = 0; thread < nthreads; thread++) {
+ for (int cpu = 0; cpu < ncpus; cpu++) {
+ *perf_counts(evsel->counts, cpu, thread) =
+ *perf_counts(evsel->summary_counts, cpu, thread);
+ }
+ }
+
+ evsel->prev_raw_counts->aggr = evsel->summary_counts->aggr;
+}
+
+void perf_evlist__copy_summary_counts(struct evlist *evlist)
+{
+ struct evsel *evsel;
+
+ evlist__for_each_entry(evlist, evsel)
+ perf_evsel__copy_summary_counts(evsel);
+}
+
+static void perf_stat_process_summary_counts(struct perf_stat_config *config,
+ struct evsel *evsel)
+{
+ struct perf_counts_values *summary = &evsel->summary_counts->aggr;
+ struct perf_stat_evsel *ps = evsel->stats;
+ u64 *count = evsel->summary_counts->aggr.values;
+ int i;
+
+ if (!config->summary || config->aggr_mode != AGGR_GLOBAL)
+ return;
+
+ for (i = 0; i < 3; i++)
+ init_stats(&ps->res_stats[i]);
+
+ perf_counts_values__scale(summary, config->scale,
+ &evsel->summary_counts->scaled);
+
+ for (i = 0; i < 3; i++)
+ update_stats(&ps->res_stats[i], count[i]);
+
+ perf_stat__update_shadow_stats(evsel, *count, 0, &rt_stat);
+}
+
+void perf_evlist__process_summary_counts(struct perf_stat_config *config,
+ struct evlist *evlist)
+{
+ struct evsel *evsel;
+
+ perf_stat__reset_shadow_per_stat(&rt_stat);
+
+ evlist__for_each_entry(evlist, evsel)
+ perf_stat_process_summary_counts(config, evsel);
+}
+
static void zero_per_pkg(struct evsel *counter)
{
if (counter->per_pkg_mask)
diff --git a/tools/perf/util/stat.h b/tools/perf/util/stat.h
index b4fdfaa7f2c0..bad7d7678148 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;
@@ -199,6 +200,10 @@ void perf_evlist__free_stats(struct evlist *evlist);
void perf_evlist__reset_stats(struct evlist *evlist);
void perf_evlist__reset_prev_raw_counts(struct evlist *evlist);

+void perf_evlist__copy_summary_counts(struct evlist *evlist);
+void perf_evlist__process_summary_counts(struct perf_stat_config *config,
+ struct evlist *evlist);
+
int perf_stat_process_counter(struct perf_stat_config *config,
struct evsel *counter);
struct perf_tool;
--
2.17.1