perf report: Add --skip-empty option to suppress 0 event stat

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

Reviewed-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20210427013717.1651674-5-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

diff --git a/tools/perf/Documentation/perf-report.txt b/tools/perf/Documentation/perf-report.txt
index f51f000..24efc05 100644 (file)
--- 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 717efd7..49627a7 100644 (file)
--- 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 be56f3e..4910194 100644 (file)
--- 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 2ab2af4..d9e6344 100644 (file)
--- a/tools/perf/ui/stdio/hist.c
+++ b/tools/perf/ui/stdio/hist.c
@@ -897,7 +897,8 @@ out:
        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 e271c80..3480baf 100644 (file)
--- 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 691a6a7..65fe65b 100644 (file)
--- 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 6b0f708..5343b62 100644 (file)
--- 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 eba3769..a6659b6 100644 (file)
--- 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 f764801..e31ba4c 100644 (file)
--- 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);