[PATCH v2 4/6] perf report: Add --skip-empty option to suppress 0 event stat

From: Namhyung Kim
Date: Mon Apr 26 2021 - 21:42:13 EST


To make the output more readable, I think it's better to remove 0's in
the output. Also the dummy event has no event stats so it just wasts
the space. Let's use the --skip-empty option to suppress it.

$ perf report --stat --skip-empty

Aggregated stats:
TOTAL events: 16530
MMAP events: 226
COMM events: 1596
EXIT events: 2
THROTTLE events: 121
UNTHROTTLE events: 117
FORK events: 1595
SAMPLE events: 719
MMAP2 events: 12147
CGROUP events: 2
FINISHED_ROUND events: 2
THREAD_MAP events: 1
CPU_MAP events: 1
TIME_CONV events: 1
cycles stats:
SAMPLE events: 719

Signed-off-by: Namhyung Kim <namhyung@xxxxxxxxxx>
---
tools/perf/Documentation/perf-report.txt | 3 +++
tools/perf/builtin-annotate.c | 4 ++--
tools/perf/builtin-report.c | 16 ++++++++++++----
tools/perf/ui/stdio/hist.c | 5 ++++-
tools/perf/util/events_stats.h | 3 ++-
tools/perf/util/hist.c | 6 +++++-
tools/perf/util/hist.h | 3 ++-
tools/perf/util/session.c | 5 +++--
tools/perf/util/session.h | 3 ++-
9 files changed, 35 insertions(+), 13 deletions(-)

diff --git a/tools/perf/Documentation/perf-report.txt b/tools/perf/Documentation/perf-report.txt
index f51f0000676e..24efc0583c93 100644
--- a/tools/perf/Documentation/perf-report.txt
+++ b/tools/perf/Documentation/perf-report.txt
@@ -571,6 +571,9 @@ include::itrace.txt[]
sampled cycles
'Avg Cycles' - block average sampled cycles

+--skip-empty::
+ Do not print 0 results in the --stat output.
+
include::callchain-overhead-calculation.txt[]

SEE ALSO
diff --git a/tools/perf/builtin-annotate.c b/tools/perf/builtin-annotate.c
index 717efd78eee6..49627a7bed7c 100644
--- a/tools/perf/builtin-annotate.c
+++ b/tools/perf/builtin-annotate.c
@@ -404,8 +404,8 @@ static int __cmd_annotate(struct perf_annotate *ann)
goto out;

if (dump_trace) {
- perf_session__fprintf_nr_events(session, stdout);
- evlist__fprintf_nr_events(session->evlist, stdout);
+ perf_session__fprintf_nr_events(session, stdout, false);
+ evlist__fprintf_nr_events(session->evlist, stdout, false);
goto out;
}

diff --git a/tools/perf/builtin-report.c b/tools/perf/builtin-report.c
index be56f3efa413..4910194acaa6 100644
--- a/tools/perf/builtin-report.c
+++ b/tools/perf/builtin-report.c
@@ -85,6 +85,7 @@ struct report {
bool group_set;
bool stitch_lbr;
bool disable_order;
+ bool skip_empty;
int max_stack;
struct perf_read_values show_threads_values;
struct annotation_options annotation_opts;
@@ -530,6 +531,9 @@ static int evlist__tty_browse_hists(struct evlist *evlist, struct report *rep, c
if (symbol_conf.event_group && !evsel__is_group_leader(pos))
continue;

+ if (rep->skip_empty && !hists->stats.nr_samples)
+ continue;
+
hists__fprintf_nr_sample_events(hists, rep, evname, stdout);

if (rep->total_cycles_mode) {
@@ -731,8 +735,8 @@ static int stats_print(struct report *rep)
{
struct perf_session *session = rep->session;

- perf_session__fprintf_nr_events(session, stdout);
- perf_evlist__fprintf_nr_events(session->evlist, stdout);
+ perf_session__fprintf_nr_events(session, stdout, rep->skip_empty);
+ evlist__fprintf_nr_events(session->evlist, stdout, rep->skip_empty);
return 0;
}

@@ -944,8 +948,10 @@ static int __cmd_report(struct report *rep)
perf_session__fprintf_dsos(session, stdout);

if (dump_trace) {
- perf_session__fprintf_nr_events(session, stdout);
- evlist__fprintf_nr_events(session->evlist, stdout);
+ perf_session__fprintf_nr_events(session, stdout,
+ rep->skip_empty);
+ evlist__fprintf_nr_events(session->evlist, stdout,
+ rep->skip_empty);
return 0;
}
}
@@ -1313,6 +1319,8 @@ int cmd_report(int argc, const char **argv)
"Sort all blocks by 'Sampled Cycles%'"),
OPT_BOOLEAN(0, "disable-order", &report.disable_order,
"Disable raw trace ordering"),
+ OPT_BOOLEAN(0, "skip-empty", &report.skip_empty,
+ "Do not display empty (or dummy) events in the output"),
OPT_END()
};
struct perf_data data = {
diff --git a/tools/perf/ui/stdio/hist.c b/tools/perf/ui/stdio/hist.c
index 2ab2af4d4849..d9e634406175 100644
--- a/tools/perf/ui/stdio/hist.c
+++ b/tools/perf/ui/stdio/hist.c
@@ -897,7 +897,8 @@ size_t hists__fprintf(struct hists *hists, bool show_header, int max_rows,
return ret;
}

-size_t events_stats__fprintf(struct events_stats *stats, FILE *fp)
+size_t events_stats__fprintf(struct events_stats *stats, FILE *fp,
+ bool skip_empty)
{
int i;
size_t ret = 0;
@@ -908,6 +909,8 @@ size_t events_stats__fprintf(struct events_stats *stats, FILE *fp)
name = perf_event__name(i);
if (!strcmp(name, "UNKNOWN"))
continue;
+ if (skip_empty && !stats->nr_events[i])
+ continue;

ret += fprintf(fp, "%16s events: %10d\n", name, stats->nr_events[i]);
}
diff --git a/tools/perf/util/events_stats.h b/tools/perf/util/events_stats.h
index e271c8004c89..3480bafd414b 100644
--- a/tools/perf/util/events_stats.h
+++ b/tools/perf/util/events_stats.h
@@ -50,6 +50,7 @@ struct hists_stats {

void events_stats__inc(struct events_stats *stats, u32 type);

-size_t events_stats__fprintf(struct events_stats *stats, FILE *fp);
+size_t events_stats__fprintf(struct events_stats *stats, FILE *fp,
+ bool skip_empty);

#endif /* __PERF_EVENTS_STATS_ */
diff --git a/tools/perf/util/hist.c b/tools/perf/util/hist.c
index 691a6a777d14..65fe65ba03c2 100644
--- a/tools/perf/util/hist.c
+++ b/tools/perf/util/hist.c
@@ -2676,7 +2676,8 @@ void hist__account_cycles(struct branch_stack *bs, struct addr_location *al,
}
}

-size_t evlist__fprintf_nr_events(struct evlist *evlist, FILE *fp)
+size_t evlist__fprintf_nr_events(struct evlist *evlist, FILE *fp,
+ bool skip_empty)
{
struct evsel *pos;
size_t ret = 0;
@@ -2684,6 +2685,9 @@ size_t evlist__fprintf_nr_events(struct evlist *evlist, FILE *fp)
evlist__for_each_entry(evlist, pos) {
struct hists *hists = evsel__hists(pos);

+ if (skip_empty && !hists->stats.nr_samples)
+ continue;
+
ret += fprintf(fp, "%s stats:\n", evsel__name(pos));
ret += fprintf(fp, "%16s events: %10d\n",
"SAMPLE", hists->stats.nr_samples);
diff --git a/tools/perf/util/hist.h b/tools/perf/util/hist.h
index 6b0f708f08ac..5343b62476e6 100644
--- a/tools/perf/util/hist.h
+++ b/tools/perf/util/hist.h
@@ -202,7 +202,8 @@ void hists__inc_nr_samples(struct hists *hists, bool filtered);
size_t hists__fprintf(struct hists *hists, bool show_header, int max_rows,
int max_cols, float min_pcnt, FILE *fp,
bool ignore_callchains);
-size_t evlist__fprintf_nr_events(struct evlist *evlist, FILE *fp);
+size_t evlist__fprintf_nr_events(struct evlist *evlist, FILE *fp,
+ bool skip_empty);

void hists__filter_by_dso(struct hists *hists);
void hists__filter_by_thread(struct hists *hists);
diff --git a/tools/perf/util/session.c b/tools/perf/util/session.c
index eba3769be3f1..a6659b616e6d 100644
--- a/tools/perf/util/session.c
+++ b/tools/perf/util/session.c
@@ -2352,7 +2352,8 @@ size_t perf_session__fprintf_dsos_buildid(struct perf_session *session, FILE *fp
return machines__fprintf_dsos_buildid(&session->machines, fp, skip, parm);
}

-size_t perf_session__fprintf_nr_events(struct perf_session *session, FILE *fp)
+size_t perf_session__fprintf_nr_events(struct perf_session *session, FILE *fp,
+ bool skip_empty)
{
size_t ret;
const char *msg = "";
@@ -2362,7 +2363,7 @@ size_t perf_session__fprintf_nr_events(struct perf_session *session, FILE *fp)

ret = fprintf(fp, "\nAggregated stats:%s\n", msg);

- ret += events_stats__fprintf(&session->evlist->stats, fp);
+ ret += events_stats__fprintf(&session->evlist->stats, fp, skip_empty);
return ret;
}

diff --git a/tools/perf/util/session.h b/tools/perf/util/session.h
index f76480166d38..e31ba4c92a6c 100644
--- a/tools/perf/util/session.h
+++ b/tools/perf/util/session.h
@@ -113,7 +113,8 @@ size_t perf_session__fprintf_dsos(struct perf_session *session, FILE *fp);
size_t perf_session__fprintf_dsos_buildid(struct perf_session *session, FILE *fp,
bool (fn)(struct dso *dso, int parm), int parm);

-size_t perf_session__fprintf_nr_events(struct perf_session *session, FILE *fp);
+size_t perf_session__fprintf_nr_events(struct perf_session *session, FILE *fp,
+ bool skip_empty);

struct evsel *perf_session__find_first_evtype(struct perf_session *session,
unsigned int type);
--
2.31.1.527.g47e6f16901-goog