perf hists browser: Warn about lost events

Just like the old perf top --tui and the --stdio version.

But because we have the initial menu to choose which event to show in a
session with multiple events we can see how many chunks were lost in
each of the event types, clarifying which events are being affected the
most.

Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-47yyqbubmjzch2chezmb21m6@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

1 files changed, 23 insertions, 6 deletions

diff --git a/tools/perf/util/session.c b/tools/perf/util/session.c
index 91c6442ef966..da354fe5e085 100644
--- a/tools/perf/util/session.c
+++ b/tools/perf/util/session.c
@@ -738,10 +738,27 @@ static int perf_session_deliver_event(struct perf_session *session,
 
         dump_event(session, event, file_offset, sample);
 
+        evsel = perf_evlist__id2evsel(session->evlist, sample->id);
+        if (evsel != NULL && event->header.type != PERF_RECORD_SAMPLE) {
+                /*
+                 * XXX We're leaving PERF_RECORD_SAMPLE unnacounted here
+                 * because the tools right now may apply filters, discarding
+                 * some of the samples. For consistency, in the future we
+                 * should have something like nr_filtered_samples and remove
+                 * the sample->period from total_sample_period, etc, KISS for
+                 * now tho.
+                 *
+                 * Also testing against NULL allows us to handle files without
+                 * attr.sample_id_all and/or without PERF_SAMPLE_ID. In the
+                 * future probably it'll be a good idea to restrict event
+                 * processing via perf_session to files with both set.
+                 */
+                hists__inc_nr_events(&evsel->hists, event->header.type);
+        }
+
         switch (event->header.type) {
         case PERF_RECORD_SAMPLE:
                 dump_sample(session, event, sample);
-                evsel = perf_evlist__id2evsel(session->evlist, sample->id);
                 if (evsel == NULL) {
                         ++session->hists.stats.nr_unknown_id;
                         return -1;
@@ -874,11 +891,11 @@ static void perf_session__warn_about_errors(const struct perf_session *session,
                                             const struct perf_event_ops *ops)
 {
         if (ops->lost == perf_event__process_lost &&
-            session->hists.stats.total_lost != 0) {
-                ui__warning("Processed %" PRIu64 " events and LOST %" PRIu64
-                            "!\n\nCheck IO/CPU overload!\n\n",
-                            session->hists.stats.total_period,
-                            session->hists.stats.total_lost);
+            session->hists.stats.nr_events[PERF_RECORD_LOST] != 0) {
+                ui__warning("Processed %d events and lost %d chunks!\n\n"
+                            "Check IO/CPU overload!\n\n",
+                            session->hists.stats.nr_events[0],
+                            session->hists.stats.nr_events[PERF_RECORD_LOST]);
         }
 
         if (session->hists.stats.nr_unknown_events != 0) {