[PATCH v6 5/5] perf stat: Report summary for interval mode

Jin Yao
2020-05-20T04:30:01Z

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

v6:
---
Move init_stats(&walltime_nsecs_stats) under interval condition check.
walltime_nsecs_stats.val holds the last value so we just need to
init the other fields of stats.

v5:
---
Call perf_evlist__save_aggr_prev_raw_counts to save aggr value
to first member of prev_raw_counts for AGGR_GLOBAL. Then next,
perf_stat_process_counter can create aggr values from per cpu
values.

v4:
---
Move affinity setup and read_counter_cpu to a new function
read_affinity_counters. It's only called when stat_config.summary
is not set.

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 | 31 +++++++++++++++++++++++++++----
tools/perf/util/stat.c | 2 +-
tools/perf/util/stat.h | 1 +
3 files changed, 29 insertions(+), 5 deletions(-)

diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c
index f3b3a59ac7d2..2486c79f0f34 100644
--- a/tools/perf/builtin-stat.c
+++ b/tools/perf/builtin-stat.c
@@ -314,14 +314,14 @@ static int read_counter_cpu(struct evsel *counter, struct timespec *rs, int cpu)
return 0;
}

-static void read_counters(struct timespec *rs)
+static int read_affinity_counters(struct timespec *rs)
{
struct evsel *counter;
struct affinity affinity;
int i, ncpus, cpu;

if (affinity__setup(&affinity) < 0)
- return;
+ return -1;

ncpus = perf_cpu_map__nr(evsel_list->core.all_cpus);
if (!target__has_cpu(&target) || target__has_per_thread(&target))
@@ -341,6 +341,15 @@ static void read_counters(struct timespec *rs)
}
}
affinity__cleanup(&affinity);
+ return 0;
+}
+
+static void read_counters(struct timespec *rs)
+{
+ struct evsel *counter;
+
+ if (!stat_config.summary && (read_affinity_counters(rs) < 0))
+ return;

evlist__for_each_entry(evsel_list, counter) {
if (counter->err)
@@ -763,7 +772,21 @@ static int __run_perf_stat(int argc, const char **argv, int run_idx)
if (stat_config.walltime_run_table)
stat_config.walltime_run[run_idx] = t1 - t0;

- update_stats(&walltime_nsecs_stats, t1 - t0);
+ if (interval) {
+ stat_config.interval = 0;
+ stat_config.summary = true;
+ init_stats(&walltime_nsecs_stats);
+ update_stats(&walltime_nsecs_stats, t1 - t0);
+
+ if (stat_config.aggr_mode == AGGR_GLOBAL)
+ perf_evlist__save_aggr_prev_raw_counts(evsel_list);
+
+ perf_evlist__copy_prev_raw_counts(evsel_list);
+ perf_evlist__reset_prev_raw_counts(evsel_list);
+ runtime_stat_reset(&stat_config);
+ perf_stat__reset_shadow_per_stat(&rt_stat);
+ } else
+ update_stats(&walltime_nsecs_stats, t1 - t0);

/*
* Closing a group leader splits the group, and as we only disable
@@ -2159,7 +2182,7 @@ 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 d23109c9bee9..cdb154381a87 100644
--- a/tools/perf/util/stat.c
+++ b/tools/perf/util/stat.c
@@ -408,7 +408,7 @@ 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 18ead55756cc..a5604a20bdca 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